BACKGROUND

A firm diagnosis of visceral leishmaniasis (kala-azar) requires demonstration of the parasite in organ aspirates or tissue biopsy samples. The aim of this prospective study was to assess the diagnostic usefulness of non-invasive testing for antibody to the leishmanial antigen K39 by means of antigen-impregnated nitrocellulose paper strips adapted for use under field conditions.

METHODS

One drop of peripheral blood is applied to the hitrocellulose strip. Three drops of test buffer (phosphate-buffered saline plus bovine serum albumin) are added to the dried blood. The development of two visible bands indicates presence of IgG anti-K39. 323 consecutive patients with suspected kala-azar referred to two specialist units in India, and 25 healthy controls, provided fingerstick blood samples for the test. Spleen aspirates were taken from 250 patients.

RESULTS

Kala-azar was confirmed by microscopy of spleen-aspirate smears in 127 patients. The K39 strip test was positive in all 127; the estimated sensitivity was therefore 100% (95% CI 98-100). Four patients had positive strip tests but negative aspirate smears; all four responded to treatment for leishmaniasis. 217 individuals, including the 25 healthy controls, 73 patients with malaria or tuberculosis, and 119 spleen-aspirate-negative patients who had presumed malaria or cirrhosis (79) or no final diagnosis (40), had negative strip-test results. None of the 119 aspirate-negative patients developed evidence of kala-azar during 3-6 months of follow-up. The estimated specificity of the strip test was 98% (95-100; 217/221).

CONCLUSIONS

Detection of anti-K39 by immunochromatographic strip testing is a rapid and non-invasive method of diagnosing kala-azar, which has good sensitivity and specificity and is well suited for use in field conditions.

OBJECTIVE

Correlation of the urinary albumin excretion rate and the risk of death among elderly subjects.

METHODS

216 Subjects aged 60-74 whose urinary albumin excretion rate had been determined were followed up 62-83 months later.

METHODS

Municipality of Fredericia, Denmark.

METHODS

223 People who had been selected as control subjects for diabetics found during a systematic screening for diabetes of all people aged 60-74 living in the municipality of Fredericia, Denmark. Of these subjects, 216 had an extensive clinical and biochemical examination within a few weeks of selection.

METHODS

Death.

RESULTS

The median urinary albumin excretion rate was 7.52 micrograms/min. Eight of those with a rate below the median died compared with 23 with a rate equal to or greater than the median (p = 0.0078). The median albumin excretion rate in the 31 who died was 15.00 micrograms/min. Cardiovascular disease was the most common cause of death in both groups. A multivariate regression analysis of survival data was performed using the proportional hazards model. Besides albumin excretion rate, male sex, serum creatinine concentration, and hypertension were found to be of prognostic value.

CONCLUSIONS

The association between the albumin excretion rate and mortality that has been described in recent years in patients with diabetes mellitus may be present in elderly people in general, even when other known risk factors are taken into account.

Eosinophils play an important role as effector cells in allergic, parasitic, and other conditions. The mechanism(s) by which eosinophils mediate their effector functions was studied by incubation of human normodense eosinophils with Sepharose beads coupled to various Ig isotypes as targets. Controls included eosinophils incubated alone or incubated with uncoated beads, human serum albumin-, or OVA-coated beads. An eosinophil granule protein, the eosinophil-derived neurotoxin (EDN), was measured as an indicator of eosinophil degranulation. Eosinophils released eosinophil-derived neurotoxin when incubated with Sepharose beads coupled to Ig of the IgG or IgA isotypes, as well as IgA-Fc fragments. Mixtures of IgG and IgA on beads did not act synergistically. Secretory IgA (sIgA) provided the most potent signal for eosinophil degranulation and was two to three times more potent than IgG. Furthermore, 2 to 17% of the normodense eosinophils bound to IgG- or IgA-coated beads, whereas 24 to 27% of the eosinophils bound to sIgA-coated beads. Thus, sIgA may be the principal Ig mediating eosinophil effector function at mucosal surfaces in helminth infections and hypersensitivity diseases, especially bronchial asthma.

BACKGROUND

Elevated circulating levels of several inflammatory biomarkers have been described in selected patient populations with COPD, although less is known about their population-based distribution. The aims of this study were to compare the levels of several systemic biomarkers between stable COPD patients and healthy subjects from a population-based sample, and to assess their distribution according to clinical variables.

METHODS

This is a cross-sectional study design of participants in the EPI-SCAN study (40-80 years of age). Subjects with any other condition associated with an inflammatory process were excluded. COPD was defined as a post-bronchodilator FEV1/FVC < 0.70. The reference group was made of non-COPD subjects without respiratory symptoms, associated diseases or prescription of medication. Subjects were evaluated with quality-of-life questionnaires, spirometry and 6-minute walk tests. Serum C-reactive protein (CRP), tumor necrosis factor (TNF)-alpha, interleukins (IL-6 and IL-8), alpha1-antitrypsin, fibrinogen, albumin and nitrites/nitrates (NOx) were measured.

RESULTS

We compared 324 COPD patients and 110 reference subjects. After adjusting for gender, age, BMI and tobacco consumption, COPD patients showed higher levels of CRP (0.477 +/- 0.023 vs. 0.376 +/- 0.041 log mg/L, p = 0.049), TNF-alpha (13.12 +/- 0.59 vs. 10.47 +/- 1.06 pg/mL, p = 0.033), IL-8 (7.56 +/- 0.63 vs. 3.57 +/- 1.13 pg/ml; p = 0.033) and NOx (1.42 +/- 0.01 vs. 1.36 +/- 0.02 log nmol/l; p = 0.048) than controls. In COPD patients, serum concentrations of some biomarkers were related to severity and their exercise tolerance was related to serum concentrations of CRP, IL-6, IL-8, fibrinogen and albumin.

CONCLUSIONS

Our results provide population-based evidence that COPD is independently associated with low-grade systemic inflammation, with a different inflammatory pattern than that observed in healthy subjects.

OBJECTIVE

The aim of this study was to investigate the interaction between the components of novel chitosan (CS) and CS/ethylene oxide-propylene oxide block copolymer (PEO-PPO) nanoparticles and to evaluate their potential for the association and controlled release of proteins and vaccines.

METHODS

The presence of PEO-PPO on the surface of the nanoparticles and its interaction with the CS was identified by X-ray photoelectron spectroscopy (XPS). The mechanism of protein association was elucidated using several proteins, bovine serum albumin (BSA), and tetanus and diphtheria toxoids, and varying the formulation conditions (different pH values and concentrations of PEO-PPO), and the stage of protein incorporation into the nanoparticles formation medium.

RESULTS

BSA and tetanus and diphtheria toxoids were highly associated with CS nanoparticles partly due to electrostatic interactions between the carboxyl groups of the protein and the amine groups of CS. PEO-PPO also interacted electrostatically with CS, thus competing with the proteins for association with CS nanoparticles. A visible amount of PEO-PPO was projected towards the outer phase of the nanoparticles. Proteins were released from the nanoparticles at an almost constant rate, the intensity of which was closely related to the protein loading. Furthermore, the tetanus vaccine was released in the active form for at least 15 days.

CONCLUSIONS

CS and CS/PEO-PPO nanoparticles prepared by a very mild ionic crosslinking technique are novel and suitable systems for the entrapment and controlled release of proteins and vaccines.

BACKGROUND

Increased exposure to intestinal bacterial products may contribute to the pathogenesis of non alcoholic steatohepatitis (NASH). Bifidobacteria are predominant bacterial species in the human gut microbiota and have been considered to exert a beneficial effect on human health by maintaining the equilibrium of the resident microbiota.

OBJECTIVE

To evaluate the effects of Bifidobacterium longum with fructo-oligosaccharides (Fos) in the treatment of NASH.

METHODS

A total of 66 patients were randomly and equally divided into two groups receiving Bifidobacterium longum with Fos and lifestyle modification (i.e., diet and exercise) versus lifestyle modification alone. The following variables were assessed at -4 (beginning of the dietary lead-in period), 0 (randomization), 6, 12, 18, and 24 weeks: aspartate transaminase (AST), alanine transaminase (ALT), bilirubin, albumin, total cholesterol, high-density lipoprotein (HDL) cholesterol, low-density lipoprotein (LDL) cholesterol, triglycerides, fasting plasma glucose, insulin, C-peptide, C-reactive protein (CRP), tumor necrosis factor (TNF)-α, homeostasis model assessment of insulin resistance (HOMA-IR), and serum endotoxins. Liver biopsies were performed at entry and repeated after 24 weeks of treatment.

RESULTS

At the end of study period, we observed that the Bifidobacterium longum with Fos and lifestyle modification group versus the lifestyle modification alone group showed significant differences in the AST -69.6 versus -45.9 IU/mL (P < 0.05), LDL cholesterol -0.84 versus -0.18 mmol/L (P < 0.001), CRP -2.9 versus -0.7 mg/L (P < 0.05), TNF-α -0.45 versus -0.12 ng/mL (P < 0.001), HOMA-IR -1.1 versus -0.6 (P < 0.001), serum endotoxin -45.2 versus -30.6 pg/mL (P < 0.001), steatosis (P < 0.05), and the NASH activity index (P < 0.05).

CONCLUSIONS

Bifidobacterium longum with Fos and lifestyle modification, when compared to lifestyle modification alone, significantly reduces TNF-α, CRP, serum AST levels, HOMA-IR, serum endotoxin, steatosis, and the NASH activity index.

In order to promote the uniform and reproducible differentiation of human embryonic stem cells (HESCs) in response to exogenously added growth factors, we have developed a method (spin embryoid bodies (EBs)) that uses a recombinant protein-based, animal product-free medium in which HESCs are aggregated by centrifugation to form EBs. In this protocol we describe the formulation of this medium, denoted APEL (Albumin Polyvinylalcohol Essential Lipids), and its use in spin EB differentiation of HESCs. We also describe a more economical variant, BPEL (Bovine Serum Albumin (BSA) Polyvinylalchohol Essential Lipids), in which BSA replaces the recombinant human albumin. The integration of a medium that includes only defined and recombinant components with a defined number of cells to initiate EB formation results in a generally applicable, robust platform for growth factor-directed HESC differentiation.

We prepared a brominated poly(dG-dC).poly(dG-dC) which forms a stable Z-DNA helix under physiological salt conditions. Rabbits and mice were immunized with brominated and unbrominated poly(dG-dC).poly(dG-dC) complexed with methylated bovine serum albumin. Antibodies specific for Z-DNA were produced. These antibodies were found not only in the sera of animals immunized with the low-salt stabilized Z-DNA [Br-poly(dG-dC).poly(dG-dC)] but also in sera from animals immunized with the unbrominated B-DNA form of the polymer. From this it is inferred that the unbrominated poly(dG-dC).poly(dG-dC) was partially converted to Z-DNA by its combination with the basic protein methylated bovine serum albumin. In addition to specific anti-Z-DNA antibody populations, two other interesting types of antibody populations were found. One of these reacted with both the Z and B forms of poly(dG-dC).poly(dG-dC). This antibody may be converting the polymer from the B-DNA to the Z-DNA form. The other type of antibody was specific for a B form of poly(dG-dC).poly(dG-dC) and did not react at all with the Z form. The antibodies raised to Z-DNA were shown to be highly specific for Z-DNA and did not react with B-DNA, RNA, DNA.RNA hybrids, or a number of other polynucleotides. This specificity for Z-DNA will make possible their use as reagents for determining the presence of Z-DNA in biological systems. Sera of autoimmune lupus mice were also shown to have a considerable amount of naturally occurring anti-Z-DNA antibody activity.

OBJECTIVE

Steroidal mineralocorticoid receptor antagonists, when added to a renin-angiotensin system blocker, further reduce proteinuria in patients with chronic kidney disease but may be underused because of a high risk of adverse events.

OBJECTIVE

To evaluate the safety and efficacy of different oral doses of the nonsteroidal mineralocorticoid receptor antagonist finerenone, given for 90 days to patients with diabetes and high or very high albuminuria who are receiving an angiotensin-converting enzyme inhibitor or an angiotensin receptor blocker.

METHODS

Randomized, double-blind, placebo-controlled, parallel-group study conducted at 148 sites in 23 countries. Patients were recruited from June 2013 to February 2014 and the study was completed in August 2014. Of 1501 screened patients, 823 were randomized and 821 received study drug.

METHODS

Participants were randomly assigned to receive oral, once-daily finerenone (1.25 mg/d, n = 96; 2.5 mg/d, n = 92; 5 mg/d, n = 100; 7.5 mg/d, n = 97; 10 mg/d, n = 98; 15 mg/d, n = 125; and 25 mg/d, n = 119) or matching placebo (n = 94) for 90 days.

METHODS

The primary outcome was the ratio of the urinary albumin-creatinine ratio (UACR) at day 90 vs at baseline. Safety end points were changes from baseline in serum potassium and estimated glomerular filtration rate.

RESULTS

The mean age of the participants was 64.2 years; 78% were male. At baseline, 36.7% of patients treated had very high albuminuria (UACR ≥300 mg/g) and 40.0% had an estimated glomerular filtration rate of 60 mL/min/1.73 m2 or lower. Finerenone demonstrated a dose-dependent reduction in UACR. The primary outcome, the placebo-corrected mean ratio of the UACR at day 90 relative to baseline, was reduced in the finerenone 7.5-, 10-, 15-, and 20-mg/d groups (for 7.5 mg/d, 0.79 [90% CI, 0.68-0.91; P = .004]; for 10 mg/d, 0.76 [90% CI, 0.65-0.88; P = .001]; for 15 mg/d, 0.67 [90% CI, 0.58-0.77; P<.001]; for 20 mg/d, 0.62 [90% CI, 0.54-0.72; P < .001]). The prespecified secondary outcome of hyperkalemia leading to discontinuation was not observed in the placebo and finerenone 10-mg/d groups; incidences in the finerenone 7.5-, 15-, and 20-mg/d groups were 2.1%, 3.2%, and 1.7%, respectively. There were no differences in the incidence of the prespecified secondary outcome of an estimated glomerular filtration rate decrease of 30% or more or in incidences of adverse events and serious adverse events between the placebo and finerenone groups.

CONCLUSIONS

Among patients with diabetic nephropathy, most receiving an angiotensin-converting enzyme inhibitor or an angiotensin receptor blocker, the addition of finerenone compared with placebo resulted in improvement in the urinary albumin-creatinine ratio. Further trials are needed to compare finerenone with other active medications.

BACKGROUND

clinicaltrials.gov Identifier: NCT1874431.

Thrombus (blood clot) is implicated in a number of life threatening diseases, e.g., heart attack, stroke, pulmonary embolism. EP-2104R is an MRI contrast agent designed to detect thrombus by binding to the protein fibrin, present in all thrombi. EP-2104R comprises an 11 amino acid peptide derivatized with 2 GdDOTA-like moieties at both the C- and N-terminus of the peptide (4 Gd in total). EP-2104R was synthesized by a mixture of solid phase and solution techniques. The La(III) analogue was characterized by and 1D and 2D NMR spectroscopy and was found to have the expected structure. EP-2104R was found to be significantly more inert to Gd(III) loss than commercial contrast agents. At the most extreme conditions tested (pH 3, 60 degrees C, 96 hrs), less than 10% of Gd was removed from EP-2104R by a challenge with a DTPA based ligand, while the commercial contrast agents equilibrated within minutes to hours. EP-2104R binds equally to two sites on human fibrin (Kd = 1.7 +/- 0.5 microM) and has a similar affinity to mouse, rat, rabbit, pig, and dog fibrin. EP-2104R has excellent specificity for fibrin over fibrinogen (over 100-fold) and for fibrin over serum albumin (over 1000-fold). The relaxivity of EP-2104R bound to fibrin at 37 degrees C and 1.4 T was 71.4 mM(-1) s(-1) per molecule of EP-2104R (17.4 per Gd), about 25 times higher than that of GdDOTA measured under the same conditions. Strong fibrin binding, fibrin selectivity, and high molecular relaxivity enable EP-2104R to detect blood clots in vivo.

BACKGROUND

Serum 25-hydroxyvitamin D (25OHD) is a key factor in determining monocyte induction of the antimicrobial protein cathelicidin, which requires intracrine conversion of 25OHD to 1,25-dihydroxyvitamin D [1,25(OH)(2)D]. Both vitamin D metabolites circulate bound to vitamin D-binding protein (DBP), but the effect of this on induction of monocyte cathelicidin remains unclear.

METHODS

Human monocytes were cultured in medium containing 1) serum from DBP knockout (DBP(-/-)) or DBP(+/-) mice, 2) serum-free defined supplement reconstituted with DBP or albumin (control), and 3) human serum with different DBP [group-specific component [Gc]] genotypes with varying affinities for vitamin D metabolites. In each case, response to added 1,25(OH)(2)D(3) or 25OHD(3) was determined by measuring expression of mRNA for cathelicidin and 24-hydroxylase. Monocyte internalization of DBP was assessed by fluorescent tagging followed by microscopic and flow cytometric analysis of tagged DBP.

RESULTS

Monocytes cultured in DBP(-/-) serum showed more potent induction of cathelicidin by 25OHD(3) or 1,25(OH)(2)D(3) when compared with DBP(+/-) serum. Likewise, DBP added to serum-free medium attenuated 25OHD(3)/1,25(OH)(2)D(3) responses. Fluorescently tagged DBP showed low-level uptake by monocytes, but this did not appear to involve a megalin-mediated mechanism. Human serum containing low-affinity Gc2-1S or Gc2-2, respectively, supported 2.75-fold (P = 0.003) and 2.43-fold (P = 0.016) higher induction of cathelicidin by 25OHD relative to cells cultured with high affinity Gc1F-1F.

CONCLUSIONS

These data indicate that DBP plays a pivotal role in regulating the bioavailablity of 25OHD to monocytes. Vitamin D-dependent antimicrobial responses are therefore likely to be strongly influenced by DBP polymorphisms.

The plasma compartment has particular features regarding the nature and concentration of low and high molecular weight thiols and oxidized derivatives. Plasma is relatively poor in thiol-based antioxidants; thiols are in lower concentrations than in cells and mostly oxidized. The different thiol-disulfide pairs are not in equilibrium and the steady-state concentrations of total thiols as well as reduced versus oxidized ratios are maintained by kinetic barriers, including the rates of reactions and transport processes. The single thiol of human serum albumin (HSA-SH) is the most abundant plasma thiol. It is an important target for oxidants and electrophiles due to its reactivity with a wide variety of species and its relatively high concentration. A relatively stable sulfenic (HSA-SO3H) acid can be formed in albumin exposed to oxidants. Plasma increases in mixed disulfides (HSA-SSR) or in sulfinic (HSA-SO2H) and sulfonic (HSA-SO3H) acids are associated with different pathologies and may constitute biomarkers of the antioxidant role of the albumin thiol. In this work we provide a critical review of the plasma thiol pool with a focus on human serum albumin.

Osteonecrosis is a severe glucocorticoid-induced complication of acute lymphoblastic leukemia treatment. We prospectively screened children (n = 364) with magnetic resonance imaging of hips and knees, regardless of symptoms; the cumulative incidence of any (grade 1-4) versus symptomatic (grade 2-4) osteonecrosis was 71.8% versus 17.6%, respectively. We investigated whether age, race, sex, acute lymphoblastic leukemia treatment arm, body mass, serum lipids, albumin and cortisol levels, dexamethasone pharmacokinetics, and genome-wide germline genetic polymorphisms were associated with symptomatic osteonecrosis. Age more than 10 years (odds ratio, = 4.85; 95% confidence interval, 2.5-9.2; P = .00001) and more intensive treatment (odds ratio = 2.5; 95% confidence interval, 1.2-4.9; P = .011) were risk factors and included as covariates in all analyses. Lower albumin (P = .05) and elevated cholesterol (P = .02) associated with symptomatic osteonecrosis, and severe (grade 3 or 4) osteonecrosis was linked to poor dexamethasone clearance (P = .0005). Adjusting for clinical features, polymorphisms of ACP1 (eg, rs12714403, P = 1.9 × 10(-6), odds ratio = 5.6; 95% confidence interval, 2.7-11.3), which regulates lipid levels and osteoblast differentiation, were associated with risk of osteonecrosis as well as with lower albumin and higher cholesterol. Overall, older age, lower albumin, higher lipid levels, and dexamethasone exposure were associated with osteonecrosis and may be linked by inherited genomic variation.

Human biomonitoring (HBM) of dose and biochemical effect nowadays has tremendous utility providing an efficient and cost effective means of measuring human exposure to chemical substances. HBM considers all routes of uptake and all sources which are relevant making it an ideal instrument for risk assessment and risk management. HBM can identify new chemical exposures, trends and changes in exposure, establish distribution of exposure among the general population, identify vulnerable groups and populations with higher exposures and identify environmental risks at specific contaminated sites with relatively low expenditure. The sensitivity of HBM methods moreover enables the elucidation of human metabolism and toxic mechanisms of the pollutants. So, HBM is a tool for scientists as well as for policy makers. Blood and urine are by far the most approved matrices. HBM can be done for most chemical substances which are in the focus of the worldwide discussion of environmental medicine. This especially applies for metals, PAH, phthalates, dioxins, pesticides, as well as for aromatic amines, perfluorinated chemicals, environmental tobacco smoke and volatile organic compounds. Protein adducts, especially Hb-adducts, as surrogates of DNA adducts measuring exposure as well as biochemical effect very specifically and sensitively are a still better means to estimate cancer risk than measuring genotoxic substances and their metabolites in human body fluids. Using very sophisticated but nevertheless routinely applicable analytical procedures Hb-adducts of alkylating agents, aromatic amines and nitro aromatic compounds are determined routinely today. To extend the spectrum of biochemical effect monitoring further methods should be elaborated which put up with cleavage and separation of the adducted protein molecules as a measure of sample preparation. This way all sites of adduction as well as further proteins, like serum albumin could be used for HBM. DNA-adducts indicate the mutagenicity of a chemical substance as well as an elevated cancer risk. DNA-adducts therefore would be ideal parameters for HBM. Though there are very sensitive techniques for DNA adduct monitoring like P32-postlabelling and immunological methods they lack specificity. For elucidating the mechanism of carcinogenesis and for a broad applicability and comparability in epidemiological studies analytical methods must be elaborated which are strictly specific for the chemical structure of the DNA-adduct. Current analytical possibilities however meet their borders. In HBM studies with exposure to genotoxic chemicals especially the measurement of DNA strand breaks in lymphocytes and 8-hydroxy-2'-deoxyguanosine (8-OHdG) in white blood cells has become very popular. However, there is still a lack of well-established dose-response relations between occupational or environmental exposures and the induction of 8-OHdG or formation of strand breaks which limits the applicability of these markers. Most of the biomarkers used in population studies are covered by standard operating procedures (SOPs) as well as by internal and external quality assessment schemes. Therefore, HBM results from the leading laboratories worldwide are analytically reliable and comparable. Newly upcoming substances of environmental relevance like perfluorinated compounds can rapidly be assessed in body fluids because there are very powerful laboratories which are able to elaborate the analytical prerequisites in due time. On the other hand, it is getting more and more difficult for the laboratories to keep up with a progress in instrumental analyses. In spite of this it will pay to reach the ultimate summit of HBM because it is the only way to identify and quantify human exposure and risk, elucidate the mechanism of toxic effects and to ultimately decide if measures have to be taken to reduce exposure. Risk assessment and risk management without HBM lead to wrong risk estimates and cause inadequate measures. In some countries like in USA and in Germany, thousands of inhabitants are regularly investigated with respect to their internal exposure to a broad range of environmentally occurring substances. For the evaluation of HBM results the German HBM Commission elaborates reference- and HBM-values.

Aflatoxins are dietary contaminants that are hepatocarcinogenic and immunotoxic and cause growth retardation in animals, but there is little evidence concerning the latter two parameters in exposed human populations. Aflatoxin exposure of West African children is known to be high, so we conducted a longitudinal study over an 8-month period in Benin to assess the effects of exposure on growth. Two hundred children 16-37 months of age were recruited from four villages, two with high and two with low aflatoxin exposure (50 children per village). Serum aflatoxin-albumin (AF-alb) adducts, anthropometric parameters, information on food consumption, and various demographic data were measured at recruitment (February) and at two subsequent time points (June and October). Plasma levels of vitamin A and zinc were also measured. AF-alb adducts increased markedly between February and October in three of the four villages, with the largest increases in the villages with higher exposures. Children who were fully weaned at recruitment had higher AF-alb than did those still partially breast-fed (p < 0.0001); the major weaning food was a maize-based porridge. There was no association between AF-alb and micronutrient levels, suggesting that aflatoxin exposure was not accompanied by a general nutritional deficiency. There was, however, a strong negative correlation (p < 0.0001) between AF-alb and height increase over the 8-month follow-up after adjustment for age, sex, height at recruitment, socioeconomic status, village, and weaning status; the highest quartile of AF-alb was associated with a mean 1.7 cm reduction in growth over 8 months compared with the lowest quartile. This study emphasizes the association between aflatoxin and stunting, although the underlying mechanisms remain unclear. Aflatoxin exposure during the weaning period may be critical in terms of adverse health effects in West African children, and intervention measures to reduce exposure merit investigation.

Experiments were carried out to evaluate the role of convection in the removal of large molecules from brain interstitial fluid. Radiolabeled test compounds were injected into the caudate nucleus of anesthetized rats through a guide cannula implanted 1 wk previously and the concentrations of isotope in brain and cerebrospinal fluid (CSF) determined at various times after injection. Control studies with 22Na indicate that the permeability of the blood-brain barrier is normal in tissue surrounding the intracerebral injection cannula. For 69,000 dalton serum albumin, 4,000 dalton polyethylene glycol, and 900 dalton polyethylene glycol, clearance from brain approximates a single exponential decay with half times of disappearance of 12.2, 12.6, and 14.4 h, respectively. Similarly in efflux rate, despite a fivefold difference in diffusion coefficient, is consistent with convective losses from brain, and the maximal rate of interstitial fluid removal estimated on the basis of these data is 0.11 microliter.g brain-1.min-1. Only 10-20% of total efflux is into bulk CSF withdrawn from the cisterna magna.

We compare two commonly used diagnostic approaches, one relying on plasma bicarbonate concentration and "anion gap," the other on "base excess," with a third method based on physicochemical principles, for their value in detecting complex metabolic acid-base disturbances. We analyzed arterial blood samples from 152 patients and nine normal subjects for pH, PCO(2), and concentrations of plasma electrolytes and proteins. Ninety-six percent of the patients had serum albumin concentration < or = 3 SD below the mean of the control subjects. In about one-sixth of the patients, base excess and plasma bicarbonate were normal. In a great majority of these apparently normal samples, the third method detected simultaneous presence of acidifying and alkalinizing disturbances, many of them grave. The almost ubiquitous hypoalbuminemia confounded the interpretation of acid-base data when the customary approaches were applied. Base excess missed serious acid-base abnormalities in about one-sixth of the patients; this method fails when the plasma concentrations of the nonbicarbonate buffers (mainly albumin) are abnormal. Anion gap detected a hidden "gap acidosis" in only 31% of those samples with normal plasma bicarbonate in which such acidosis was diagnosed by the third method; when adjusted for hypoalbuminemia, it reliably detected the hidden abnormal anions. The proposed third method identifies and quantifies individual components of complex acid-base abnormalities and provides insights in their pathogenesis.

We examined the relationship between changes in cardiac output and middle cerebral artery mean blood velocity (MCA V(mean)) in seven healthy volunteer men at rest and during 50% maximal oxygen uptake steady-state submaximal cycling exercise. Reductions in were accomplished using lower body negative pressure (LBNP), while increases in were accomplished using infusions of 25% human serum albumin. Heart rate (HR), arterial blood pressure and MCA V(mean) were continuously recorded. At each stage of LBNP and albumin infusion was measured using an acetylene rebreathing technique. Arterial blood samples were analysed for partial pressure of carbon dioxide tension (P(a,CO2). During exercise HR and were increased above rest (P < 0.001), while neither MCA V(mean) nor P(a,CO2) was altered (P>> 0.05). The MCA V(mean) and were linearly related at rest (P < 0.001) and during exercise (P = 0.035). The slope of the regression relationship between MCA V(mean) and at rest was greater (P = 0.035) than during exercise. In addition, the phase and gain between MCA V(mean) and mean arterial pressure in the low frequency range were not altered from rest to exercise indicating that the cerebral autoregulation was maintained. These data suggest that the associated with the changes in central blood volume influence the MCA V(mean) at rest and during exercise and its regulation is independent of cerebral autoregulation. It appears that the exercise induced sympathoexcitation and the change in the distribution of between the cerebral and the systemic circulation modifies the relationship between MCA V(mean) and .

BACKGROUND

A number of screening criteria, applied either at a single point in time or serially, can be used for the purpose of identifying individuals at risk of end-stage renal disease (ESRD). This study focused on two such criteria measured on a single occasion, proteinuria and renal insufficiency, and examined their prevalence in a sample representative of the adult U.S. non-institutionalized population. Such knowledge guides the utility of population screening to prevent ESRD.

METHODS

The prevalence of albuminuria (microalbuminuria and macroalbuminuria from a random urine albumin-to-creatinine ratio) and renal insufficiency [glomerular filtration rate (GFR) estimated from serum creatinine] was determined in different age categories in various adult screening groups in the cross-sectional Third National Health and Nutrition Examination Survey (NHANES III).

RESULTS

A total of 14,622 adult participants were included in the analysis. In the general population, 8.3% and 1.0% of participants demonstrated microalbuminuria and macroalbuminuria, respectively. To identify one case of albuminuria, one would need to screen three persons with diabetes mellitus, seven non-diabetic hypertensive persons, or six persons over the age of 60. When albuminuria and renal insufficiency were considered together, it was clear that these tests were identifying different segments of the population; 37% of participants with a GFR less than 30 mL/min/1.73 m2 demonstrated no albuminuria. Non-albuminuric renal insufficiency was most evident in the ages of 60 to 79; 34% of diabetics, and 63% of non-diabetic hypertensives with a GFR less than 30 mL/min/1.73 m2 demonstrated no albuminuria.

CONCLUSIONS

Albuminuria is prevalent, and when considered together, screening tests of albuminuria and renal insufficiency measured on a single occasion identify different segments of the population. The prevalence of albuminuria and renal insufficiency in populations of interest should be considered, as this knowledge has implications for the effectiveness of screening.

Proteins which have been exposed to the hydroxyl radical (.OH) or to the combination of .OH plus the superoxide anion radical and oxygen (.OH + O2- + O2) exhibit altered primary structure and increased proteolytic susceptibility. The present work reveals that alterations to primary structure result in gross distortions of secondary and tertiary structure. Denaturation/increased hydrophobicity of bovine serum albumin (BSA) by .OH, or by .OH + O2- + O2 was maximal at a radical/BSA molar ratio of 24 (all .OH or 50% .OH + 50% O2-). BSA exposed to .OH also underwent progressive covalent cross-linking to form dimers, trimers, and tetramers, partially due to the formation of intermolecular bityrosine. In contrast, .OH + O2- + O2 caused spontaneous BSA fragmentation. Fragmentation of BSA produced new carbonyl groups with no apparent increase in free amino groups. Fragmentation may involve reaction of (.OH-induced) alpha-carbon radicals with O2 to form peroxyl radicals which decompose to fragment the polypeptide chain at the alpha-carbon, rather than at peptide bonds. BSA fragments induced by .OH + O2- + O2 exhibited molecular weights of 7,000-60,000 following electrophoresis under denaturing conditions, but could be visualized as hydrophobic aggregates in nondenaturing gels (confirmed with [3H]BSA following treatment with urea or acid). Combinations of various chemical radical scavengers (mannitol, urate, t-butyl alcohol, isopropyl alcohol) and gases (N2O, O2, N2) revealed that .OH is the primary species responsible for alteration of BSA secondary and tertiary structure. Oxygen, and O2- serve only to modify the outcome of .OH reaction. Furthermore, direct studies of O2- + O2 (in the absence of .OH) revealed no measurable changes in BSA structure. The process of denaturation/increased hydrophobicity was found to precede either covalent cross-linking (by .OH) or fragmentation (by .OH + O2- + O2). Denaturation was half-maximal at a radical/BSA molar ratio of 9.6, whereas half-maximal aggregation or fragmentation occurred at a ratio of 19.4. Denaturation/hydrophobicity may hold important clues for the mechanism(s) by which oxygen radicals can increase proteolytic susceptibility.

BACKGROUND

One of the surgical options available for the super-obese patient is the sleeve gastrectomy. We present results of this operation in a series of 118 patients.

METHODS

The charts of all patients who have had the sleeve gastrectomy performed were reviewed for demographic data, complications, weight, and nutritional parameters.

RESULTS

Median age was 47 years (16-70). Median BMI was 55 kg/m(2) (37-108), with 73% of patients having a BMI>> or =50 kg/m(2). 41% of the patients were male. The operation was performed by laparotomy in all but three cases, which were performed laparoscopically. Median hospital stay was 6 days (3-59). There was one perioperative death (0.85%). 18 patients (15.3%) had postoperative complications. Median percent excess weight loss was 37.8% at 6 months, 49.4% at 12 months, and 47.3% at 24 months. Median follow-up was 13 months (1-66). At 1 year postoperatively, the percentage of patients with normal serum levels of albumin was 100%, hemoglobin 86.1%, and calcium 87.2%, compared to 98.1%, 85.6%, and 94.3% preoperatively. 6 patients requested conversion to a duodenal switch during the follow-up period; all left the hospital in 4-6 days without major complication.

CONCLUSIONS

Although the sleeve gastrectomy does not result in as much weight loss as the duodenal switch or gastric bypass, it can be used as a stand-alone operation or as a bridge to more complex procedures in the high-risk super-obese patient.

A nonspecific opsonin function has been ascribed to human alpha 2 HS glycoprotein. Its serum level has been shown to be decreased in trauma patients. Recent studies from this laboratory revealed a heterogeneity among the products obtained in the course of the preparation of the protein. To date, no definitive agreement existed with regard to a molecular homogeneous entity of alpha 2 HS glycoprotein (Ba-alpha 2 glycoproteins). The purpose of the current work was to study the variations in serum level of alpha 2 HS in patients suffering from an acute inflammatory process of bacterial etiology and to determine whether a decrease in alpha 2 HS was accompanied by the appearance of fragments of this protein in the serum. A method of preparing alpha 2 HS was thus developed, using an immune absorbent as a final purification step. In an intermediary step of the preparation, alpha 2 HS was found to bind zinc when metal chelate affinity chromatography was employed. Immunologically and physico-chemically pure alpha 2 HS was obtained. The protein consists of a unique polypeptide chain of about 50,000 daltons and has a unique amino-terminal residue, alanine. However, the protein maintained its molecular integrity with difficulty, and spontaneous fragments ranging from 30,000 to less than 10,000 daltons were produced in some of the preparations. No major modification in the molecular structure of the protein was noted in the sera of subjects suffering from an acute inflammatory process. Serum level of alpha 2 HS and alpha 1 antitrypsin (AT)was determined in 23 patients. When the acute-phase (AP-)reactant alpha 1 AT was increased (difference with normal mean greater than +2 or +3 SD), the sera showed a large decrease in alpha 2 HS (difference with normal mean less than -2 or -3 SD). The serum level of alpha 2 HS, albumin, alpha 2 macroglobulin, and of positive AP-reactants, orosomucoidinal study of seven patients. The results were submitted to a principal components analysis. Alpha 2 HS showed a negative correlation with the AP-reactants alpha 1 AT, orosomucoid, and haptoglobin (P less than 0.05) and a positive correlation with albumin (P less than 0.05); these findings indicate that alpha 2 HS is a negative AP-reactant. In addition, analysis of the principal components confirms thestrong analogy between alpha 2 HS and albumin and indicates that serum level behavior of the AP-reactants during the course of the disease closely depends on the protein studied.

The possible combination of specific physicochemical properties operating at unique sites of action within cells and tissues has led to considerable uncertainty surrounding nanomaterial toxic potential. We have investigated the importance of proteins adsorbed onto the surface of two distinct classes of nanomaterials (single-walled carbon nanotubes [SWCNTs]; 10-nm amorphous silica) in guiding nanomaterial uptake or toxicity in the RAW 264.7 macrophage-like model. Albumin was identified as the major fetal bovine or human serum/plasma protein adsorbed onto SWCNTs, while a distinct protein adsorption profile was observed when plasma from the Nagase analbuminemic rat was used. Damaged or structurally altered albumin is rapidly cleared from systemic circulation by scavenger receptors. We observed that SWCNTs inhibited the induction of cyclooxygenase-2 (Cox-2) by lipopolysaccharide (LPS; 1 ng/ml, 6 h) and this anti-inflammatory response was inhibited by fucoidan (scavenger receptor antagonist). Fucoidan also reduced the uptake of fluorescent SWCNTs (Alexa647). Precoating SWCNTs with a nonionic surfactant (Pluronic F127) inhibited albumin adsorption and anti-inflammatory properties. Albumin-coated SWCNTs reduced LPS-mediated Cox-2 induction under serum-free conditions. SWCNTs did not reduce binding of LPS(Alexa488) to RAW 264.7 cells. The profile of proteins adsorbed onto amorphous silica particles (50-1000 nm) was qualitatively different, relative to SWCNTs, and precoating amorphous silica with Pluronic F127 dramatically reduced the adsorption of serum proteins and toxicity. Collectively, these observations suggest an important role for adsorbed proteins in modulating the uptake and toxicity of SWCNTs and nano-sized amorphous silica.