<em>D</em>NA damage induced by ultraviolet radiation is the key initiator for skin carcinogenesis since mutations may arise from the photoproducts and it also contributes to photoimmune suppression. The active vitamin <em>D</em> hormone, 1α,<em>2</em>5 dihydroxyvitamin <em>D</em>(3) (1,<em>2</em>5(OH)(<em>2</em>)<em>D</em>(3)) reduces thymine <em>dimers</em>, the major photoproduct found in human skin after UV exposure, and suppresses the accumulation of nitric oxide derivatives that lead to more toxic reactive nitrogen species (RNS). We examined whether other forms of <em>D</em>NA damage are reduced by 1,<em>2</em>5(OH)(<em>2</em>)<em>D</em>(3), and hypothesized that photoprotection by 1,<em>2</em>5(OH)(<em>2</em>)<em>D</em>(3) is, in part, due to the suppression of various forms of promutagenic <em>D</em>NA damage, including thymine <em>dimers</em>, through a reduction of genotoxic RNS. <em>D</em>ifferent forms of UV-induced <em>D</em>NA damage were investigated in irradiated skin cells treated with or without 1,<em>2</em>5(OH)(<em>2</em>)<em>D</em>(3), or inhibitors of metabolism and inducible nitric oxide synthase. Keratinocytes were also treated with nitric oxide donors in the absence of UV light. <em>D</em>NA damage was assessed by comet assay incorporating site specific <em>D</em>NA repair endonucleases, and by immunohistochemistry using antibodies to thymine <em>dimers</em> or 8-oxo-7,8-dihydro-<em>2</em>'-deoxyguanosine, and quantified by image analysis. Strand breaks in T4 endonuclease V, endonuclease IV and human 8-oxoguanine <em>D</em>NA glycosylase digests increased more than <em>2</em>-fold in UV irradiated human keratinocytes, and were reduced by 1,<em>2</em>5(OH)(<em>2</em>)<em>D</em>(3) treatment after UV exposure, and also by low temperature, sodium azide and an inhibitor of inducible nitric oxide synthase. Conversely, nitric oxide donors induced all three types of <em>D</em>NA damage in the absence of UV. We present data to show that 1,<em>2</em>5(OH)(<em>2</em>)<em>D</em>(3) protects skin cells from at least three forms of UV-induced <em>D</em>NA damage, and provide further evidence to support the proposal that a reduction in RNS by 1,<em>2</em>5(OH)(<em>2</em>)<em>D</em>(3) is a likely mechanism for its photoprotective effect against oxidative and nitrative <em>D</em>NA damage, as well as cyclobutane pyrimidine <em>dimers</em>.

OBJECTIVE

Epidemiological and laboratory studies suggest that increasing concentrations of plasma homocysteine (total homocysteine [tHcy]) accelerate cardiovascular disease by promoting vascular inflammation, endothelial dysfunction, and hypercoagulability.

METHODS

We conducted a randomized controlled trial in <em>2</em>85 patients with recent transient ischemic attack or stroke to examine the effect of lowering tHcy with folic acid <em>2</em> mg, vitamin B1<em>2</em> 0.5 mg, and vitamin B6 <em>2</em>5 mg compared with placebo on laboratory markers of vascular inflammation, endothelial dysfunction, and hypercoagulability.

RESULTS

At 6 months after randomization, there was no significant difference in blood concentrations of markers of vascular inflammation (high-sensitivity C-reactive protein [P=0.3<em>2</em>]; soluble CD40L [P=0.33]; IL-6 [P=0.77]), endothelial dysfunction (vascular cell adhesion molecule-1 [P=0.<em>2</em>7]; intercellular adhesion molecule-1 [P=0.08]; von Willebrand factor [P=0.9<em>2</em>]), and hypercoagulability (P-selectin [P=0.33]; prothrombin fragment 1 and <em>2</em> [P=0.81]; D-dimer [P=0.88]) among patients assigned vitamin therapy compared with placebo despite a 3.7-micromol/L (95% CI, <em>2</em>.7 to 4.7) reduction in total homocysteine (tHcy).

CONCLUSIONS

Lowering tHcy by 3.7 micromol/L with folic acid-based multivitamin therapy does not significantly reduce blood concentrations of the biomarkers of inflammation, endothelial dysfunction, or hypercoagulability measured in our study. The possible explanations for our findings are: (1) these biomarkers are not sensitive to the effects of lowering tHcy (eg, multiple risk factor interventions may be required); (<em>2</em>) elevated tHcy causes cardiovascular disease by mechanisms other than the biomarkers measured; or (3) elevated tHcy is a noncausal marker of increased vascular risk.

The pectic polysaccharide rhamnogalacturonan II (RG-II), which accounts for approximately <em>2</em>0% of the ethanol-precipitable polysaccharides in red wine, has been isolated from wine polysaccharides by anion-exchange chromatography. Four fractions enriched with RG-II were obtained and the RG-II then purified to homogeneity by Concanavalin A affinity and size-exclusion chromatographies. The glycosyl-residue compositions of the four RG-IIs are similar; all the RG-IIs contain the monosaccharides (apiose, <em>2</em>-O-methyl-L-fucose, <em>2</em>-O-methyl-<em>D</em>-xylose, Kdo, <em>D</em>ha, and aceric acid) that are diagnostic of RG-II. The glycosyl-linkages of the neutral and acidic sugars, including aceric acid, were determined simultaneously by GC-EIMS analysis of the methylated alditol acetates generated from per-O-methylated and carboxyl-reduced RG-II. Two of the RG-IIs contain boron, most likely as a borate di-ester that cross-links two molecules of RG-II together to form a <em>dimer</em>. The <em>dimer</em> contains 3'- and <em>2</em>,3,3'-linked apiosyl residues whereas the monomer contains only 3'-linked apiosyl residues which suggests that the borate di-ester is located on at least one of the apiosyl residues of RG-II. Although the wine RG-IIs all have similar structures they are not identical since they differ in the length and degree of methyl-esterification of the RG-II backbone and in the presence or absence of borate di-esters. Nevertheless, these studies show that the major structural features of wine and primary cell wall RG-II are conserved.

Introduction: Coronavirus disease (COVID-19) is associated with a high incidence of thrombosis and mortality despite standard anticoagulant thromboprophylaxis. There is equipoise regarding the optimal dose of anticoagulant intervention in hospitalized patients with COVID-19 and consequently, immediate answers from high-quality randomized trials are needed.

<strong class="sub-title"> Methods: </strong> The World Health Organization's International Clinical Trials Registry Platform was searched on June 17, <em>2</em>0<em>2</em>0 for randomized controlled trials comparing increased dose to standard dose anticoagulant interventions in hospitalized COVI<em>D</em>-19 patients. Two authors independently screened the full records for eligibility and extracted data in duplicate.

<strong class="sub-title"> Results: </strong> A total of <em>2</em>0 trials were included in the review. All trials are open-label, 5 trials use an adaptive design, 1 trial uses a factorial design, <em>2</em> trials combine multi-arm parallel group and factorial designs in flexible platform trials, and at least 15 trials have multiple study sites. With individual target sample sizes ranging from 30 to 3,000 participants, the pooled sample size of all included trials is 1<em>2</em>,568 participants. Two trials include only ICU patients, and 10 trials base patient eligibility on elevated <em>D</em>-<em>dimer</em> levels. Therapeutic intensity anticoagulation is evaluated in 14 trials. All-cause mortality is part of the primary outcome in 14 trials.

Discussion: Several trials evaluate different dose regimens of anticoagulant interventions in hospitalized patients with COVID-19. Since these trials compete for sites and study participants, a collaborative effort is needed to complete trials faster, conduct pooled analyses and bring effective interventions to patients more quickly.

Keywords: Anticoagulant; COVID-19; Pulmonary Embolism; Research Networks; Thrombosis.

Patients with atrial fibrillation have been reported to exhibit abnormal hemostasis. Since nitric oxide (NO) exerts antithrombotic effects and attenuates platelet function, we evaluated two indicators of plasma NO levels, the plasma levels of nitrite and nitrate (NOx), and the levels of cGMP in platelets. We also examined whether indicators of plasma NO levels were associated with abnormalities in parameters related to platelet function, blood coagulation, and fibrinolysis. We evaluated 45 patients with chronic sustained atrial fibrillation (33 men and 1<em>2</em> women, age range 63 +/- <em>2</em> years) compared with 45 sex- and age- (+/- <em>2</em> years) matched nonhospitalized subjects with sinus rhythm. There were no significant differences between the two groups in the incidence of risk factors for stroke except for ischemic heart disease or in echocardiographic parameters. Plasma levels of NOx measured using the Greiss reagent (mean [interquartile range]: 15.6 [9.5 to <em>2</em>5.7] versus <em>2</em>4.1 [14.<em>2</em> to 40.8] mumol/L, n = 45) and the platelet cGMP levels (0.33 [0.16 to 0.67] versus 0.63 [0.31 to 1.<em>2</em>9] pmol/10(9) platelets, n = 9) were significantly (P < .05) lower in the patients with atrial fibrillation than in the control subjects. Plasma levels of <em>D</em>-<em>dimer</em>, beta-thromboglobulin, and fibrinogen were significantly (P < .05) higher in the patients with atrial fibrillation. The two groups did not differ as to the plasma levels of tissue plasminogen activator or plasminogen activator inhibitor-1. Our findings suggest that a decrease in plasma NO levels may account for the hemostatic abnormalities observed in patients with atrial fibrillation.

<em>D</em>IC is a life-threatening complication of several disease states. It is characterized by systemic activation of the hemostasis system. In many instances the release of tissue factor (TF) from endothelial cells or other circulating cells triggers the system. Initially, the increased activation can be compensated for by the natural inhibitor systems, a state referred to as compensated <em>D</em>IC. As the trigger persists, inhibitors will be consumed leading to more coagulation. In this process many clotting factors, most notably fibrinogen and platelets are consumed, resulting eventually in a complete breakdown of the hemostasis system. This results in a profuse and diffuse bleeding tendency or decompensated <em>D</em>IC. The term consumptive coagulopathy denotes this process. Of crucial importance is the fate of fibrin that is formed from fibrinogen by thrombin. If the fibrinolytic system is insufficiently activated, fibrin will be deposited in the microcirculation leading to MO<em>D</em>S. This will not occur if the fibrinolytic system is fully activated. The clinical suspicion of <em>D</em>IC must be confirmed by laboratory tests and decreasing fibrinogen levels and platelet counts support the diagnosis. The determination of <em>D</em>-<em>dimer</em>, fibrin(ogen) split products (FSP) and soluble fibrin monomer (FM) further support the diagnosis. FM suggest the presence of thrombin, FSP the generation of plasmin, and <em>D</em>-<em>dimer</em>, both thrombin and plasmin. While the tests are not specific for <em>D</em>IC, they can be helpful, in the proper clinical setting, to diagnose decompensated or acute <em>D</em>IC. The tests are not useful for the diagnosis of compensated <em>D</em>IC, except for <em>D</em>-<em>dimer</em>, FSP, and FM if elevated. Compensated <em>D</em>IC can be diagnosed by molecular markers of in vivo hemostasis activation, such as thrombin-antithrombin (TAT) complexes, prothrombin fragment 1 + <em>2</em> (F 1 + <em>2</em>), or plasmin-antiplasmin (PAP) complexes. For the treatment of <em>D</em>IC it is imperative to remove the triggering underlying disease. The consumption of coagulation constituents can be corrected by cryoprecipitate, platelet concentrates, and fresh frozen plasma, if needed. This may reduce the bleeding tendency. Arrest of the activated hemostasis system by heparins, either subcutaneous in low doses or intravenous in therapeutic doses, is only recommended in patients with compensated <em>D</em>IC. If the patient bleeds, heparins should not be given. The administration of concentrates of natural anticoagulants, i.e., antithrombin, protein C, or tissue factor pathway inhibitor are safer than heparins since they do not exacerbate the bleeding tendency. These concentrates were found to be very effective in animal models of <em>D</em>IC; human experience is still limited. Generally, the earlier treatment is initiated, the better the patient's prognosis.

OBJECTIVE

The study aimed to evaluate the prognostic value of pretreatment plasma dimerized plasmin fragment D (D-dimer), fibrinogen, and platelet levels in epithelial ovarian cancer (EOC) after adjusting for venous thromboembolism (VTE) and to screen out the patients with the greatest risk for poor prognosis.

METHODS

The study comprised 190 patients with EOC. The plasma D-dimer, fibrinogen, and platelet levels were examined before treatment and analyzed with patient clinicopathological parameters, progression-free survival (PFS), and overall survival (OS). The survival analysis was performed using the Kaplan-Meier method, and prognostic factors were assessed using the Cox proportional hazards regression model.

RESULTS

The incidences of elevated plasma D-dimer levels, hyperfibrinogenemia, and thrombocytosis were 40%, 42.11%, and 45.26%, respectively. Elevated plasma D-dimer level, hyperfibrinogenemia, and thrombocytosis were associated with advanced tumor stage (P < 0.001, P = 0.013, P < 0.001). In addition, the elevated plasma D-dimer levels were associated with macroscopic postoperative residual disease (P = 0.002) and VTE events (P = 0.006). In multivariate Cox regression model, plasma D-dimer, fibrinogen, and platelet levels were identified as independent prognostic factors for OS (P = 0.039, P = 0.002, and P = 0.049). However, plasma fibrinogen and platelet levels, but not D-dimer levels, had independent prognostic value for PFS (P = 0.012 and P = 0.022). Patients with at least any 2 abnormalities of plasma D-dimer, fibrinogen, and platelet levels showed shorter PFS and OS than did patients with at most 1 abnormality of 3 parameters (P < 0.001).

CONCLUSIONS

Pretreatment plasma D-dimer, fibrinogen, and platelet levels, which impact prognosis independently of VTE, were demonstrated to be potential markers to predict disease progression and surgery outcome in patients with EOC. The combined use of plasma D-dimer, fibrinogen, and platelet levels may help to identify the high-risk populations for treatment decisions.

OBJECTIVE

To determine the roles of tissue factor and thrombin on the systemic inflammatory response syndrome (SIRS) in posttrauma patients, as well as to investigate the relationship between SIRS and sepsis.

METHODS

Prospective, cohort study.

METHODS

General intensive care unit of a tertiary care emergency department.

METHODS

Forty trauma patients were classified into subgroups, according to the duration of SIRS: non-SIRS patients (n = 9); patients with SIRS for < <em>2</em> days (n = 15); and patients with SIRS for>> 3 days (n = 16).

METHODS

None.

RESULTS

Tissue factor antigen concentration, prothrombin fragment F1+<em>2</em>, thrombin antithrombin complex, fibrinopeptide A, and cross-linked fibrin degradation products (D-dimer) were measured on the day of admission, and on days 1 through 4 after admission. Simultaneously, the number of SIRS criteria that the patients met and the disseminated intravascular coagulation score were determined. The results of these measurements, frequency of acute respiratory distress syndrome (ARDS), multiple organ dysfunction syndrome, sepsis, and outcome were compared among the groups. The values of all five hemostatic molecular markers in the patients with SIRS for>> 3 days were significantly more increased than those molecular marker values measured in the other groups on the day of admission. These values continued to be markedly high up to day 4 of admission. The occurrence rates of disseminated intravascular coagulation in these patient groups were significantly higher than those rates in the other two groups (p = .0001), and the disseminated intravascular coagulation scores did not improve during the study period. The occurrence rates of ARDS (p < .05) and multiple organ dysfunction syndrome (p < .01) were higher in patients with SIRS for>> 3 days compared with those rates in the other groups, and the patients with SIRS for>> 3 days had a poor outcome. No significant difference was noted in the frequency of sepsis among the groups.

CONCLUSIONS

Sustained SIRS is the main determinant for ARDS, multiple organ dysfunction syndrome, and outcome in posttrauma patients. Disseminated intravascular coagulation associated with massive thrombin generation and its activation is involved in the pathogenesis of sustained SIRS. Sepsis has a small role in early posttrauma multiple organ dysfunction syndrome.

Heterogeneous ribonucleoprotein A1 (hnRNP A1) is an abun<em>d</em>ant nuclear protein that participates in RNA processing, alternative splicing, an<em>d</em> chromosome maintenance. hnRNP A1 can be proteolyze<em>d</em> to unwin<em>d</em>ing protein (UP1), a <em>2</em><em>2</em>.1-kDa protein that retains a high affinity for purine-rich single-stran<em>d</em>e<em>d</em> nucleic aci<em>d</em>s, inclu<em>d</em>ing the human telomeric repeat (hTR) <em>d</em>(TTAGGG)n. Using the structure of UP1 boun<em>d</em> to hTR as a gui<em>d</em>e, we have incorporate<em>d</em> the fluorescent guanine analog 6-MI at one of two positions within the DNA to facilitate bin<em>d</em>ing stu<em>d</em>ies. One is where 6-MI remains stacke<em>d</em> with an a<em>d</em>jacent purine, an<em>d</em> another is where it becomes fully unstacke<em>d</em> upon UP1 bin<em>d</em>ing. The structures of both mo<em>d</em>ifie<em>d</em> oligonucleoti<em>d</em>es complexe<em>d</em> to UP1 were <em>d</em>etermine<em>d</em> by x-ray crystallography to vali<em>d</em>ate the efficacy of our <em>d</em>esign, an<em>d</em> 6-MI has proven to be an excellent reporter molecule for single-stran<em>d</em>e<em>d</em> nucleic aci<em>d</em> interactions in positions where there is a change in stacking environment upon complex formation. We have shown that UP1 affinity for <em>d</em>(TTAGGG)<em>2</em> is approximately 5 nm at 100 mm NaCl, pH 6.0, an<em>d</em> our bin<em>d</em>ing stu<em>d</em>ies with <em>d</em>(TTAGG(6-MI)TTAGGG) show that bin<em>d</em>ing is only mo<em>d</em>estly sensitive to salt an<em>d</em> pH. UP1 also has a potent G-tetra<em>d</em> <em>d</em>estabilizing activity that re<em>d</em>uces the Tm of the hTR sequence <em>d</em>(TAGGGT)4 from 67.0 <em>d</em>egrees C to 36.1 <em>d</em>egrees C at physiological con<em>d</em>itions (150 mm KCl, pH 7.0). Consistent with the structures <em>d</em>etermine<em>d</em> by x-ray crystallography, UP1 is able to bin<em>d</em> the hTR sequence in solution as a <em>dimer</em> an<em>d</em> supports a mo<em>d</em>el for hnRNP A1 bin<em>d</em>ing to nucleic aci<em>d</em>s in arrays that may make a contiguous set of anti-parallel single-stran<em>d</em>e<em>d</em> nucleic aci<em>d</em> bin<em>d</em>ing clefts. These <em>d</em>ata suggest that seemingly <em>d</em>isparate roles for hnRNP A1 in alternative splice site selection, RNA processing, RNA transport, an<em>d</em> chromosome maintenance reflect its ability to bin<em>d</em> a purine-rich consensus sequence (nYAGGn) an<em>d</em> <em>d</em>estabilize potentially <em>d</em>eleterious G-tetra<em>d</em> structures.

The correlation of coagulopathy and pupillary light reflex, the degree of midline shift in brain computer tomography and Glasgow outcome scale (GOS) after head injury were prospectively evaluated. From September <em>2</em>00<em>2</em> to March <em>2</em>003, 61 patients (45 males and 16 females; mean age: 41.9 years) after head injury were enrolled in the study. A modified coagulopathy score (CS) defined by prothrombin time, partial thromboplastin time, platelet count, <em>D</em>-<em>dimer</em> and fibrinogen was calculated for each patient within <em>2</em>4 h after injury. The CS was <em>2</em>.3+/-<em>2</em>.7 (mean+/-S<em>D</em>). The incidence of abnormal coagulation following head injury in non-survival cases was 100% and in survival cases 66%. The mortality rate was significantly increased to 75% in CS above 4 and 100% if CS was 6 or greater. The increase of <em>D</em>-<em>dimer</em> concentration appears to be common yet abnormal platelet counts are relatively uncommon among head trauma patients. Within 4 h after head injury, there is an initial hypercoagulable stage followed by hypocoagulable stage 6 h after head injury. Our results showed pupillary light reflex has the most significant correlation to GOS (rho = 0.7<em>2</em>7, p < 0.0001). It also reveals that coagulopathy score>> or 4 (positive predictive value 90%) may have higher degree of accuracy to predict mortality comparing to both pupils being fixed or brain CT midline shift>> or = 15 mm. We conclude that: (1) Coagulation state in head injury patients within <em>2</em>4 h after injury is of value in determining the outcome. (<em>2</em>) Coagulopathy score>> or = 4 is a good predictor to evaluate mortality rate of head injury patients.

BACKGROUND

Limited information exists on the dynamics of hemostasis in patients with venom-induced consumption coagulopathy (VICC) from snake envenomation.

OBJECTIVE

The aim of the present study was to investigate specific factor deficiencies and their time course in Australasian elapid envenomation.

METHODS

We measured coagulation parameters and factor concentrations in patients recruited to the Australian Snakebite Project, an observational cohort study. There were 112 patients with complete VICC, defined as an international normalized ratio (INR)>> 3, and 18 with partial VICC. Serial citrated plasma samples were collected from 0.5 to 60 h post-bite. INR, activated partial thromboplastin time (aPTT), coagulation factors (F)I, II, V, VII, VIII, IX, X, von Willebrand factor antigen (VWF:Ag) and D-dimer concentrations were measured.

RESULTS

Complete VICC was characterized by near/total depletion of fibrinogen, FV and FVIII, with an INR and aPTT that exceeded the upper limits of detection, within 2 h of snakebite. Prothrombin levels never fell below 60% of normal, suggesting that the toxins were rapidly eliminated or inactivated and re-synthesis of clotting factors occurred irrespective of antivenom. Partial VICC caused limited depletion of fibrinogen and FV, and almost complete consumption of FVIII. Onset of VICC was more rapid with brown snake (Pseudonaja spp.) venom, which contains a group C prothrombin activator toxin, compared with the tiger snake group, which contains a group D prothrombin activator toxin and requires human FVa formation. Resolution of VICC occurred within 24-36 h irrespective of snake type.

CONCLUSIONS

These results suggest that Australasian elapid prothrombin activators have a potent but short duration of action. Antivenom is unlikely to be administered in time to prevent VICC.

The fungal toxin cytochalasin <em>D</em> (C<em>D</em>) interferes with the normal dynamics of the actin cytoskeleton by binding to the barbed end of actin filaments. <em>D</em>espite its widespread use as a tool for studying actin-mediated processes, the exact location and nature of its binding to actin have not been previously determined. Here we describe two crystal structures of an expressed monomeric actin in complex with C<em>D</em>: one obtained by soaking preformed actin crystals with C<em>D</em>, and the other obtained by cocrystallization. The binding site for C<em>D</em>, in the hydrophobic cleft between actin subdomains 1 and 3, is the same in the two structures. Polar and hydrophobic contacts play equally important roles in C<em>D</em> binding, and six hydrogen bonds stabilize the actin-C<em>D</em> complex. Many unrelated actin-binding proteins and marine toxins target this cleft and the hydrophobic pocket at the front end of the cleft (viewing actin with subdomain <em>2</em> in the upper right corner). C<em>D</em> differs in that it binds to the back half of the cleft. The ability of C<em>D</em> to induce actin <em>dimer</em> formation and actin-catalyzed ATP hydrolysis may be related to its unique binding site and the necessity to fit its bulky macrocycle into this cleft. Contacts with residues lining this cleft appear to be crucial to capping and/or severing. The cocrystallized actin-C<em>D</em> structure also revealed changes in actin conformation. An approximately 6 degrees rotation of the smaller actin domain (subdomains 1 and <em>2</em>) with respect to the larger domain (subdomains 3 and 4) results in small changes in crystal packing that allow the <em>D</em>-loop to adopt an extended loop structure instead of being disordered, as it is in most crystal structures of actin. We speculate that these changes represent a potential conformation that the actin monomer can adopt on the pathway to polymerization or in the filament.

BACKGROUND

Early classification of ischemic stroke subtype is important for secondary stroke prevention and may guide further investigations.

METHODS

Levels of coagulation activation [fibrinopeptide A (FPA), prothrombin fragment 1+<em>2</em> (F1+<em>2</em>), thrombin-antithrombin complex (TAT)] and fibrinolysis activation [plasmin-alpha(<em>2</em>)-antiplasmin complex (PAP), <em>D</em>-<em>dimers</em>] markers were measured in 98 consecutive patients with a first-ever acute ischemic stroke admitted within 1<em>2</em> h after symptom onset.

RESULTS

Median age was 67 years and 44% were women. Median time from symptom onset to blood sampling was 4 h. Stroke subtype was classified as 'cardioembolic' (54%), 'large-artery atherosclerosis' (11%), 'small-vessel disease' (5%), 'other determined' (9%) or 'undetermined etiology' (<em>2</em>0%). Patients with cardioembolic stroke suffered more often from coronary artery disease than patients with other stroke etiologies (40 vs. <em>2</em><em>2</em>%, p = 0.019). There were no differences in age, sex, stroke severity, time to blood sampling, frequency of hypertension, diabetes mellitus or current smoking. <em>D</em>-<em>dimers</em> (medians) were higher in patients with cardioembolic strokes than in those with other etiologies (615 vs. 3<em>2</em><em>2</em> microg/l, p < 0.001). No differences in F1+<em>2</em>, FPA, TAT or PAP levels were found. After multivariate analysis, higher <em>D</em>-dimer levels remained independently associated with cardioembolic stroke (p = 0.0<em>2</em><em>2</em>). When measured within 6 h, <em>D</em>-<em>dimers</em> below 300 microg/l excluded cardioembolic stroke with a sensitivity of 100% and a specificity of 5<em>2</em>%.

CONCLUSIONS

Low D-dimer levels in the first few hours make a cardioembolic stroke unlikely, and may be useful to guide further investigations. Other coagulation markers were not useful in differentiating between different stroke etiologies.

Since the onset of the global pan<em>d</em>emic in early <em>2</em>0<em>2</em>0, coronavirus <em>d</em>isease <em>2</em>019 (COVID-19) has pose<em>d</em> a multitu<em>d</em>e of challenges to health care systems worl<em>d</em>wi<em>d</em>e. In or<em>d</em>er to combat these challenges an<em>d</em> <em>d</em>evise appropriate therapeutic strategies, it becomes of paramount importance to eluci<em>d</em>ate the pathophysiology of this illness. Coronavirus <em>d</em>isease <em>2</em>019, cause<em>d</em> by the novel severe acute respiratory syn<em>d</em>rome coronavirus <em>2</em> (SARS-CoV<em>2</em>), is characterize<em>d</em> by a <em>d</em>ysregulate<em>d</em> immune system an<em>d</em> hypercoagulability. COVID-associate<em>d</em> coagulopathy (CAC) was recognize<em>d</em> base<em>d</em> on profoun<em>d</em> <em>d</em>-<em>dimer</em> elevations an<em>d</em> evi<em>d</em>ence of microthrombi an<em>d</em> macrothrombi, both in venous an<em>d</em> arterial systems. The un<em>d</em>erlying mechanisms associate<em>d</em> with CAC have been suggeste<em>d</em>, but not clearly <em>d</em>efine<em>d</em>. The mo<em>d</em>el of immunothrombosis illustrates the elaborate crosstalk between the innate immune system an<em>d</em> coagulation. The ren<em>d</em>ering of a procoagulant state in COVID-19 involves the interplay of many innate immune pathways. The SARS-CoV<em>2</em> virus can <em>d</em>irectly infect immune an<em>d</em> en<em>d</em>othelial cells, lea<em>d</em>ing to en<em>d</em>othelial injury an<em>d</em> <em>d</em>ysregulation of the immune system. Activate<em>d</em> leukocytes potentiate a procoagulant state via release of intravascular tissue factor, platelet activation, NETosis, an<em>d</em> inhibition of anticoagulant mechanisms. A<em>d</em><em>d</em>itional pathways of specific relevance in CAC inclu<em>d</em>e cytokine release an<em>d</em> complement activation. All these mechanisms have recently been reporte<em>d</em> in COVID-19. Immunothrombosis provi<em>d</em>es a comprehensive perspective of the several synergistic pathways pertinent to the pathogenesis of CAC.

Keywords: COVID-19; coagulopathy; immunothrombosis.

Patients affected by severe coronavirus induced disease-<em>2</em>019 (Covid-19) often experience hypoxemia due to alveolar involvement and endothelial dysfunction, which leads to the formation of micro thrombi in the pulmonary capillary vessels. Both hypoxemia and a prothrombotic diathesis have been associated with more severe disease and increased risk of death. To date, specific indications to treat this condition are lacking. This was a single center, investigator initiated, compassionate use, proof of concept, case control, phase IIb study (<a href="http://clinicaltrials.gov/show/NCT04368377" title="See in ClinicalTrials.gov">NCT04368377</a>) conducted in the Intermediate Respiratory Care Unit of L. Sacco University Hospital in Milano, Italy. Our objective was to explore the effects of the administration of anti-platelet therapy on arterial oxygenation and clinical outcomes in patients with severe Covid-19 with hypercoagulability. We enrolled five consecutive patients with laboratory confirmed SARS-CoV-<em>2</em> infection, severe respiratory failure requiring helmet continuous positive airway pressure (CPAP), bilateral pulmonary infiltrates and a pro-thrombotic state identified as a <em>D</em>-<em>dimer</em> > 3 times the upper limit of normal. Five patients matched for age, <em>D</em>-<em>dimer</em> value and SOFA score formed the control group. Beyond standard of care, treated patients received <em>2</em>5 μg/Kg/body weight tirofiban as bolus infusion, followed by a continuous infusion of 0.15 μg/Kg/body weight per minute for 48 hours. Before tirofiban, patients received acetylsalicylic acid <em>2</em>50 mg infusion and oral clopidogrel 300 mg; both were continued at a dose of 75 mg daily for 30 days. Fondaparinux<em>2</em>.5 mg/day sub-cutaneous was given for the duration of the hospital stay. All controls were receiving prophylactic or therapeutic dose heparin, according to local standard operating procedures. Treated patients consistently experienced a mean (S<em>D</em>) reduction in A-a O<em>2</em> gradient of -3<em>2</em>.6 mmHg (61.9, P = 0.154), -5<em>2</em>.4 mmHg (59.4, P = 0.016) and -151.1 mmHg (56.6, P = 0.011; P = 0.047 vs. controls) at <em>2</em>4, 48 hours and 7 days after treatment. PaO<em>2</em>/FiO<em>2</em> ratio increased by 5<em>2</em> mmHg (50, P = 0.17<em>2</em>), 64 mmHg (47, P = 0.040) and 11<em>2</em> mmHg (51, P = 0.036) after <em>2</em>4, 48 hours and 7 days, respectively. All patients but one were successfully weaned from CPAP after 3 days. This was not true for the control group. No major adverse events were observed. Antiplatelet therapy might be effective in improving the ventilation/perfusion ratio in Covid-19 patients with severe respiratory failure. The effects might be sustained by the prevention and interference on forming clots in lung capillary vessels and by modulating megakaryocytes' function and platelet adhesion. Randomized clinical trials are urgently needed to confirm these results.

Keywords: Antiplatelet; Coagulation; Coronavirus; Covid-19; D-dimer; Respiratory failure.

<strong class="sub-title"> Background and objectives: </strong> Since <em>D</em>ecember <em>2</em>019, coronavirus disease <em>2</em>019 (COVI<em>D</em>-19) outbreak occurred and has rapidly spread worldwide. However, little information is available about the AKI in COVI<em>D</em>-19. We aimed to evaluate the incidence, risk factors, and prognosis of AKI in adult patients with COVI<em>D</em>-19.

<strong class="sub-title"> <em>D</em>esign, setting, participants, & measurements: </strong> This was a retrospective cohort study of 139<em>2</em> patients with COVI<em>D</em>-19 admitted to a tertiary teaching hospital. Clinical characteristics and laboratory data were extracted from electronic hospitalization and laboratory databases. AKI was defined and staged according to the <em>2</em>01<em>2</em> Kidney <em>D</em>isease: Improving Global Outcomes criteria. Risk factors for AKI and the association of AKI with in-hospital mortality were assessed.

<strong class="sub-title"> Results: </strong> A total of 7% (99 of 139<em>2</em>) of patients developed AKI during hospitalization, 40% (40 of 99) of which occurred within 1 week of admission. Factors associated with a higher risk of AKI include severe disease (odds ratio [OR], <em>2</em>.<em>2</em>5; 95% confidence interval [CI], 1.37 to 3.67), higher baseline serum creatinine (OR, <em>2</em>.19; 95% CI, 1.17 to 4.11), lymphopenia (OR, 1.99; 95% CI, 1.1<em>2</em> to 3.53), and elevated <em>D</em>-<em>dimer</em> level (OR, <em>2</em>.68; 95% CI, 1.07 to 6.70). The in-hospital mortality in patients with AKI stage 1, stage <em>2</em>, and stage 3 was 6<em>2</em>%, 77%, and 80%, respectively. AKI was associated with in-hospital mortality even after adjustment for confounders (OR, 5.1<em>2</em>; 95% CI, <em>2</em>.70 to 9.7<em>2</em>).

Conclusions: AKI is uncommon but carries high in-hospital mortality in patients with COVID-19.

Keywords: COVID-19; acute kidney injury; mortality; prognosis; risk factors.

In humans the mitochon<em>d</em>rial inner membrane protein Oxa1L is involve<em>d</em> in the biogenesis of membrane proteins an<em>d</em> facilitates the insertion of both mitochon<em>d</em>rial- an<em>d</em> nuclear-enco<em>d</em>e<em>d</em> proteins from the mitochon<em>d</em>rial matrix into the inner membrane. The C-terminal approximately 100-amino aci<em>d</em> tail of Oxa1L (Oxa1L-CTT) bin<em>d</em>s to mitochon<em>d</em>rial ribosomes an<em>d</em> plays a role in the co-translational insertion of mitochon<em>d</em>ria-synthesize<em>d</em> proteins into the inner membrane. Contrary to suggestions ma<em>d</em>e for yeast Oxa1p, our results in<em>d</em>icate that the C-terminal tail of human Oxa1L <em>d</em>oes not form a coile<em>d</em>-coil helical structure in solution. The Oxa1L-CTT exists primarily as a monomer in solution but forms <em>dimers</em> an<em>d</em> tetramers at high salt concentrations. The bin<em>d</em>ing of Oxa1L-CTT to mitochon<em>d</em>rial ribosomes is an enthalpy-<em>d</em>riven process with a K(<em>d</em>) of 0.3-0.8 microM an<em>d</em> a stoichiometry of <em>2</em>. Oxa1L-CTT cross-links to mammalian mitochon<em>d</em>rial homologs of the bacterial ribosomal proteins L13, L<em>2</em>0, an<em>d</em> L<em>2</em>8 an<em>d</em> to mammalian mitochon<em>d</em>rial specific ribosomal proteins MRPL48, MRPL49, an<em>d</em> MRPL51. Oxa1L-CTT <em>d</em>oes not cross-link to proteins <em>d</em>ecorating the conventional exit tunnel of the bacterial large ribosomal subunit (L<em>2</em><em>2</em>, L<em>2</em>3, L<em>2</em>4, an<em>d</em> L<em>2</em>9).

Influenza A/H5N1 infection has become the major emerging infectious disease of global concern again since late <em>2</em>003. A history of exposure to dead or sick poultry or wild birds occurs in over 60% of cases of human H5N1 infection. The incubation period of avian-to-human transmission is generally between <em>2</em> and 5 days and the median duration of symptoms before hospitalization is about 4.5 days. The clinical spectrum has ranged from asymptomatic infection or mild influenza-like illness to severe pneumonia and multi-organ failure. Fever>> 38 degrees C, cough and dyspnoea are the major symptoms on presentation, whereas gastrointestinal symptoms such as watery diarrhoea, vomiting and abdominal pain are common early in the course of the disease. In contrast, upper respiratory tract symptoms are less prominent in human H5N1 infection when compared to seasonal influenza. Laboratory features of human H5N1 infection include leucopoenia, especially lymphopenia, elevated amino-transaminases, thrombocytopenia, prolonged prothrombin time and activated partial thromboplastin time, increased <em>D</em>-<em>Dimer</em>, increased serum lactate dehydrogenase and creatinine phospho-kinase, and hypoalbuminemia. A low absolute lymphocyte count on admission is associated with more severe disease and death. Radiographic abnormalities include multi-focal airspace consolidation, interstitial infiltrates, patchy or lobar involvement, with rapid progression to bilateral and diffuse ground-glass opacities consistent with AR<em>D</em>S. However, none of the clinical, laboratory and radiographic features are specific to H5N1 infection. A detailed exposure history needs to be elicited, including any close contact with sick or dead poultry, wild birds, other severely ill persons, travel to an area with A/H5N1 activity or work in laboratory handling samples possibly containing A/H5N1 virus.

OBJECTIVE

This work was undertaken to investigate comparative effect of AT1 receptor blocker (ARB), 3-hydroxy-3-methylglutaryl (HMG) coenzymeA (CoA) reductase inhibitor (statin), and their combination on vascular injury of salt-sensitive hypertension.

RESULTS

Salt-loa<em>d</em>e<em>d</em> Dahl salt-sensitive hypertensive rats (DS rats) were treate<em>d</em> with (1) vehicle, (<em>2</em>) hy<em>d</em>ralazine (5 mg/kg/<em>d</em>), (3) olmesartan (0.5 mg/kg/<em>d</em>), (4) pravastatin (100 mg/kg/<em>d</em>), an<em>d</em> (5) combine<em>d</em> olmesartan an<em>d</em> pravastatin for 4 weeks. Olmesartan or pravastatin significantly an<em>d</em> comparably improve<em>d</em> vascular en<em>d</em>othelium-<em>d</em>epen<em>d</em>ent relaxation to acetylcholine, coronary arterial remo<em>d</em>eling, an<em>d</em> eNOS activity of DS rats. Olmesartan prevente<em>d</em> vascular eNOS <em>dimer</em> <em>d</em>isruption or the <em>d</em>ownregulation of <em>d</em>ihy<em>d</em>rofolate re<em>d</em>uctase (DHFR) more than pravastatin, whereas Akt phosphorylation was enhance<em>d</em> by pravastatin but not olmesartan, in<em>d</em>icating <em>d</em>ifferential pleiotropic effects between olmesartan an<em>d</em> pravastatin. A<em>d</em><em>d</em>-on pravastatin significantly enhance<em>d</em> the improvement of vascular en<em>d</em>othelial <em>d</em>ysfunction an<em>d</em> remo<em>d</em>eling by olmesartan in DS rats. Moreover, pravastatin enhance<em>d</em> the increase in eNOS activity by olmesartan, being associate<em>d</em> with a<em>d</em><em>d</em>itive effects of pravastatin on phosphorylation of Akt an<em>d</em> eNOS.

CONCLUSIONS

Olmesartan and pravastatin exerted beneficial vascular effects in salt-sensitive hypertension, via differential pleiotropic effects. Pravastatin enhanced vascular protective effects of olmesartan. Thus, the combination of ARB with statin may be the potential therapeutic strategy for vascular diseases of salt-sensitive hypertension.

OBJECTIVE

We sought to investigate whether patients with in-stent thrombosis (IST) display altered plasma fibrin clot properties.

RESULTS

We studied 47 definite IST patients, including 15 with acute, <em>2</em>6 subacute and 6 late IST, and 48 controls matched for demographics, cardiovascular risk factors, concomitant treatment and angiographic/stent parameters. Plasma clot permeability (K(s)), which indicates a pore size, turbidity (lag phase, indicating the rate of fibrin clot formation, <em>D</em>eltaAbs(max), maximum absorbance of a fibrin gel, reflecting the fiber thickness), lysis time (t(50%)) and maximum rate of <em>D</em>-<em>dimer</em> release from clots (<em>D</em>-<em>D</em>(rate)) were determined <em>2</em> to 73 (median 14.7) months after IST. Patients with IST had <em>2</em>1% lower K(s), 14% higher <em>D</em>eltaAbs(max), 11% lower <em>D</em>-<em>D</em>(rate), 30% longer t(50%) (all P<0.0001) and 5% shorter lag phase compared to controls (P=0.04<em>2</em>). There were no correlations between clot variables and the time of IST or that from IST to blood sampling. Multiple regression analysis showed that K(s) (odds ratio=0.36 per 0.1 microm(<em>2</em>), P<0.001), <em>D</em>-<em>D</em>(rate) (odds ratio=0.16 per 0.01 mg/L/min, P<0.001) and stent length (odds ratio=1.1 per 1 mm, P=0.043) were independent predictors of IST (R(<em>2</em>)=0.58, P<0.001).

CONCLUSIONS

IST patients tend to form dense fibrin clots resistant to lysis, and altered plasma fibrin clot features might contribute to the occurrence of IST.

We present a putative link between maternal COVI<em>D</em>19 infection in the peripartum period and rapid maternal deterioration with early organ dysfunction and coagulopathy. The current pandemic with SARS-CoV-<em>2</em> has already resulted in high numbers of critically ill patients and deaths in the non-pregnant population, mainly due to respiratory failure. <em>D</em>uring viral outbreaks, pregnancy poses a uniquely increased risk to women due to changes to immune function, alongside physiological adaptive alterations, such as increased oxygen consumption and edema of the respiratory tract. The laboratory derangements may be reminiscent of HELLP syndrome, and thus knowledge of the COVI<em>D</em>19 relationship is paramount for appropriate diagnosis and management. In addition to routine measurements of <em>D</em>-<em>dimers</em>, prothrombin time, and platelet count in all patients presenting with COVI<em>D</em>19 as per ISTH guidance, monitoring of APTT and fibrinogen levels should be considered in pregnancy, as highlighted in this report. These investigations in SARS-CoV-<em>2</em>-positive pregnant women are vital, as their derangement may signal a more severe COVI<em>D</em>19 infection, and may warrant pre-emptive admission and consideration of delivery to achieve maternal stabilization.

<b>Objective:</b> To investigate the clinical characteristics of medical staff with novel coronavirus pneumonia(NCP). <b>Methods:</b> 30 patients infected with novel coronavirus referred to jianghan university hospital between January 11, <em>2</em>0<em>2</em>0 and January 3, <em>2</em>0<em>2</em>0 were studied. The data reviewed included those of clinical manifestations, laboratory investigation and Radiographic features. <b>Results:</b> The patients consisted of 10 men and <em>2</em>0 women, including <em>2</em><em>2</em> doctors and 8 nurses,aged <em>2</em>1~59 years(mean 35±8 years).They were divided to <em>2</em>6 common type and 4 severe cases, all of whom had close(within 1m) contact with patients infected of novel coronavirus pneumonia. The average contact times were 1<em>2</em> (7,16) and the average cumulative contact time was <em>2</em> (1.5,<em>2</em>.7) h.Clinical symptoms of these patients were fever in <em>2</em>3 patients (76.67%) , headache in 16 petients (53.33%) , fatigue or myalgia in <em>2</em>1patients (70%) , nausea, vomiting or diarrhea in 9 petients (30%) , cough in <em>2</em>5 petients (83.33%) , and dyspnea in 14 petients (46.67%) .Routine blood test revealed WBC<4.0×10(9)/L in 8 petients (<em>2</em>6.67%) , (4-10) ×10(9)/L in <em>2</em><em>2</em> petients (73.33%) , and WBC>4.0×10(9)/L in 4 petients (13.33%) during the disease.Lymphocyte coun<i>t<</i>1.0×10(9)/L occurred in 1<em>2</em> petients (40%),abnormal liver function in 7 petients (<em>2</em>3.33%) ,myocardial damage in 5 petients(16.67%), elevated <em>D</em>-<em>dimer</em> (>0.5mg/l) in 5 patients (16.67%). Compared with normal patients, the average exposure times, cumulative exposure time, BMI, Fever time, white blood cell count, liver enzyme, L<em>D</em>H, myoenzyme and <em>D</em>-<em>dimer</em> were significantly increased in severe patients, while the lymphocyte count and albumin levels in peripheral blood were significantly decreased.Chest CT mainly showed patchy shadows and interstitial changes.According to imaging examination, 11 patients (36.67%) showed Unilateral pneumonia and 19 patients (63.33%) showed bilateral pneumonia,4 patients (13.33%) showed bilateral multiple mottling and ground-glass opacity.Compared with the patients infected in the protected period, the proportion of severe infection and bilateral pneumonia were both increased in the patients infected in unprotected period. <b>Conclusion:</b> Medical staffs are at higher risk of infection.Infection rates are associated with contact time, the amount of suction virus. Severe patients had BMI increased, heating time prolonged, white blood cell count, lymphocyte count, <em>D</em>-<em>dimer</em> and albumin level significantly changed and were prone to be complicated with liver damage and myocardial damage.Strict protection measures is important to prevent infection for medical workers.

Background: The unpredictability of the progression of coronavirus disease 2019 (COVID-19) may be attributed to the low precision of the tools used to predict the prognosis of this disease. Objective: To identify the predictors associated with poor clinical outcomes in patients with COVID-19. Methods: Relevant articles from PubMed, Embase, Cochrane, and Web of Science were searched and extracted as of April 5, 2020. Data of interest were collected and evaluated for their compatibility for the meta-analysis. Cumulative calculations to determine the correlation and effect estimates were performed using the Z test. Results: In total, 19 papers recording 1,934 mild and 1,644 severe cases of COVID-19 were included. Based on the initial evaluation, 62 potential risk factors were identified for the meta-analysis. Several comorbidities, including chronic respiratory disease, cardiovascular disease, diabetes mellitus, and hypertension were observed more frequent among patients with severe COVID-19 than with the mild ones. Compared to the mild form, severe COVID-19 was associated with symptoms such as dyspnea, anorexia, fatigue, increased respiratory rate, and high systolic blood pressure. Lower levels of lymphocytes and hemoglobin; elevated levels of leukocytes, aspartate aminotransferase, alanine aminotransferase, blood creatinine, blood urea nitrogen, high-sensitivity troponin, creatine kinase, high-sensitivity C-reactive protein, interleukin 6, D-dimer, ferritin, lactate dehydrogenase, and procalcitonin; and a high erythrocyte sedimentation rate were also associated with severe COVID-19. Conclusion: More than 30 risk factors are associated with a higher risk of severe COVID-19. These may serve as useful baseline parameters in the development of prediction tools for COVID-19 prognosis.

Keywords: COVID-19; SARS-CoV-2; clinical outcome; prognosis; severity.

<strong class="sub-title"> Objective: </strong> Patients with coronavirus disease <em>2</em>019 (COVI<em>D</em>-19) have a high rate of thrombosis. We hypothesized that severe acute respiratory syndrome coronavirus <em>2</em> leads to induction of TF (tissue factor) expression and increased levels of circulating TF-positive extracellular vesicles (EV) that may drive thrombosis. Approach and Results: We measured levels of plasma EV TF activity in 100 patients with COVI<em>D</em>-19 with moderate and severe disease and <em>2</em>8 healthy controls. Levels of EV TF activity were significantly higher in patients with COVI<em>D</em>-19 compared with controls. In addition, levels of EV TF activity were associated with disease severity and mortality. Finally, levels of EV TF activity correlated with several plasma markers, including <em>D</em>-<em>dimer</em>, which has been shown to be associated with thrombosis in patients with COVI<em>D</em>-19.

<strong class="sub-title"> Conclusions: </strong> Our results indicate that severe acute respiratory syndrome coronavirus <em>2</em> infection induces the release of TF-positive EVs into the circulation that are likely to contribute to thrombosis in patients with COVI<em>D</em>-19. EV TF activity was also associated with severity and mortality.

Keywords: COVID-19; coronavirus; extracellular vesicles; fibrinogen; thrombosis.