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Publication
Journal: Clinical Proteomics
February/17/2013
Abstract
BACKGROUND
Tuberculous meningitis is a frequent extrapulmonary disease caused by Mycobacterium tuberculosis and is associated with high mortality rates and severe neurological sequelae. In an earlier study employing DNA microarrays, we had identified genes that were differentially expressed at the transcript level in human brain tissue from cases of tuberculous meningitis. In the current study, we used a quantitative proteomics approach to discover protein biomarkers for tuberculous meningitis.
METHODS
To compare brain tissues from confirmed cased of tuberculous meningitis with uninfected brain tissue, we carried out quantitative protein expression profiling using iTRAQ labeling and LC-MS/MS analysis of SCX fractionated peptides on Agilent's accurate mass QTOF mass spectrometer.
CONCLUSIONS
Through this approach, we identified both known and novel differentially regulated molecules. Those described previously included signal-regulatory protein alpha (SIRPA) and protein disulfide isomerase family A, member 6 (PDIA6), which have been shown to be overexpressed at the mRNA level in tuberculous meningitis. The novel overexpressed proteins identified in our study included amphiphysin (AMPH) and neurofascin (NFASC) while ferritin light chain (FTL) was found to be downregulated in TBM. We validated amphiphysin, neurofascin and ferritin light chain using immunohistochemistry which confirmed their differential expression in tuberculous meningitis. Overall, our data provides insights into the host response in tuberculous meningitis at the molecular level in addition to providing candidate diagnostic biomarkers for tuberculous meningitis.
Publication
Journal: Cancer Letters
January/5/2003
Abstract
Bromodichloromethane (BDCM) and bromoform (TBM) have been demonstrated to be colon carcinogens in male and female F344/N rats following administration by corn oil gavage. Our chronic bioassay of BDCM administered in the drinking water failed to demonstrate colon cancer in male F344/N rats. In the present study we addressed the capability of trihalomethanes (THMs) administered in drinking water to induce aberrant crypt foci (ACF), early putative preneoplastic lesions, in the colons of male F344/N rats and B6C3F(1) mice. BDCM was tested in the A/J mouse strain. Rats and B6C3F(1) mice were exposed to isomolar concentrations of the THMs [0.5 g/l chloroform (TCM), 0.7 g/l BDCM, 0.9 g/l dibromochloromethane (DBCM), or 1.1 g/l (TBM)] for 13 weeks. A/J mice were exposed to 0.5 g/l BDCM in the drinking water for 13 and 30 weeks. Deionized water and 0.25% Alkamuls EL-620 were the negative and vehicle controls. ACF incidence (percent) and number (ACF/colon) for the rat were: combined controls, 0; AOM, 100%, 27.17+/-6.28 (P<0.01); TCM, 16.7%, 0.17+/-0.17; BDCM, 83.3%, 1.50+/-0.56 (P<0.01); DBCM, 50%, 1.17+/-0.65 (P<0.01); TBM, 66.7%, 1.17+/-0.40 (P<0.01). THM-induced ACF primarily occurred in the rectal segment of the colon (92%). No ACF were observed in the colons of B6C3F(1) mice following 13 weeks of THM treatment or in the colons of A/J mice following 13 and 30 weeks of BDCM exposure. These studies demonstrate that brominated THMs administered in the drinking water significantly induced preneoplastic ACF in the colon of rats.
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Publication
Journal: The American journal of physiology
June/15/1989
Abstract
Tunicamycin (TM) was used in toad urinary bladder (TBM) cells to study the role of N-glycosylation of the beta-subunit of Na+-K+-ATPase. Inhibition of the beta-subunit core glycosylation was dose dependent and coincided with a specific 70% decrease in newly synthesized beta- and alpha-subunits. Na+-K+-ATPase activity paralleled the decrease in the cellular content of the alpha-subunit, although the cellular and cell surface-expressed Na+-K+-ATPase pool was progressively filled up with nonglycosylated beta-subunits. In addition, the decrease in maximal Na+ transport capacity of the Na+-K+-ATPase as assessed by short-circuit current (SCC) measurements in the presence of amphotericin B correlated with the decrease in the total cell surface-expressed beta-subunit population despite the fact that it was composed of 47% nonglycosylated beta-subunits after 42 h of TM treatment. These results are consistent with the interpretation that beta-subunit glycosylation is not important either for the enzyme's intracellular sorting to the plasma membrane or its hydrolytic and transport properties. Finally, TM produced effects on basal SCC and electrical resistance that differed in their times of onset and time periods needed for recovery. Thus, in addition to the Na+-K+-ATPase, other glycoproteins in the apical membrane and the tight junctions must be implicated in the maintenance of transepithelial Na+ transport.
Publication
Journal: Journal of Pediatrics
August/13/1978
Abstract
A child with diphenylhydantoin hypersensitivity developed an associated interstitial nephritis. Circulating autoantibody of the IgG class which reacted with normal human tubular basement membrane was linearly deposited along host renal TBM. Cell-mediated immunity to the DPH antigen was also present. In addition, deposits of DPH were demonstrated along the renal TBM. It is suggested that initial alteration of host renal TBM by DPH deposition with secondary immune injury directed at the DPH-TBM antigen may have altered the TBM or uncovered new antigenic sites, rendering it susceptible to further injury on an autoimmune basis.
Publication
Journal: Journal of Aerosol Medicine and Pulmonary Drug Delivery
July/1/2010
Abstract
BACKGROUND
Inhaled alpha1-antitrypsin (AAT) is being developed for treatment of cystic fibrosis to protect the lungs from excessive free elastase. High drug costs mandate a very efficient aerosol system to deliver a high payload to the airways. The I-neb Adaptive Aerosol Delivery (AAD) System is a portable, electronic, vibrating mesh nebulizer that delivers aerosol only during inhalation. It can be operated in conventional tidal breathing mode (TBM) or in target inhalation mode (TIM) that guides the patient to inhale deeply and slowly. The purposes of this in vitro study were to determine aerosol characteristics, device efficiency, and delivery time of AAT using the I-neb AAD System with TBM and TIM.
METHODS
We studied the I-neb AAD System in TBM and TIM (inspiratory time 6 or 9 sec) using a breath simulator. The loaded dose was 0.5 mL AAT (50 mg/mL). Nebulized drug captured on an inspiratory filter was reported as emitted dose. Particle size was measured by laser diffraction. Predicted lung doses were calculated based on the results of a prior scintigraphy study of the I-neb AAD System.
RESULTS
Particle size (VMD) for TBM and TIM was similar (4.4-4.8 microm). The emitted doses were very high and similar between modes (82-90% of loaded dose). Predicted lung dose of AAT (percent of loaded dose) and delivery times were: TBM 56.6% in 7.5 min; TIM-6 59.9% in 4.4 min; and TIM-9 64.5% in 2.5 min.
CONCLUSIONS
The I-neb AAD System enhanced AAT delivery by inhalation-only aerosol generation and a low-residual dose. Predicted lung dose was high for both TBM and TIM, but longer inspiratory times with TIM reduced the administration time to one-third that of tidal breathing. We conclude that slow, deep, controlled inspirations using the I-neb AAD System is an efficient method to deliver AAT.
Publication
Journal: Arquivos Brasileiros de Cardiologia
June/24/2009
Abstract
BACKGROUND
Aerobic exercise is an important ally in the fight against cardiovascular risk factors. However, the effects of high-intensity exercise on these factors are still poorly known.
OBJECTIVE
To compare the effects of aerobic and anaerobic exercise protocols on cardiac risk factors.
METHODS
22 individuals with mean age of 40+/-8 years were distributed into the following groups: control (CO), endurance training (ET) and interval training (IT). The protocols lasted 12 weeks, three times a week, with intensities of 10% below and 20% above the anaerobic threshold (AnT). The following measurements were taken: total body mass (TBM), body mass index (BMI), waist circumference (WC), hip circumference (HC), and body composition, in addition to plasma concentrations of glucose (GLU), total cholesterol (CHO), and triglycerides (TG). Waist-hip ratio (WHR) and conicity index (C index) were also calculated.
RESULTS
The TBM, BMI, WC, GLU, and body composition variables showed significant changes in the ET and IT groups. CHO and HC values were significantly reduced in the ET group, whereas WHR showed a significant reduction in the IT group. AnT and C index in the IT group were significantly different in relation to ET.
CONCLUSIONS
In view of the differences found in the results of the variables studied in relation to the training performed, we conclude that an exercise program that includes both high and low-intensity activities is more efficient to ensure the reduction of a greater number of cardiac risk variables.
Publication
Journal: Biochemistry
April/25/2013
Abstract
The enzyme tyramine β-monooxygenase (TβM) belongs to a small eukaryotic family of physiologically important mononuclear dicopper monooxygenases. The properties of this family include noncoupled mononuclear copper centers ~11 Å apart, with Cu(M) performing C-H and O(2) activation and Cu(H) functioning as an electron storage site [Klinman, J. P. (2006) J. Biol. Chem. 281, 3013-3016]. A conserved tyrosine (Y216 in TβM) is positioned between the copper domains and is associated with Cu(H) (through an interaction with a Cu(H)-coordinating histidine). Mutations at Y216 (to W, I, and A) indicate little or no difference in electron paramagnetic resonance spectra, while X-ray absorption spectroscopy studies show only a very small decrease in distance between Cu(M) and its Met471 ligand in reduced enzyme. High-performance liquid chromatography assays demonstrate that turnover of substrate is complete with Y216W and Y216I, whereas Y216A undergoes a secondary inactivation that is linked to oxidation of ligands at Cu(M). Steady-state kinetic and isotope effect measurements were investigated. The significantly elevated K(m,Tyr) for Y216A, together with a very large (D)(k(cat)/K(m,Tyr)) of ~12, indicates a major impact on the binding of substrate at the Cu(M) site. The kinetic and isotopic parameters lead to estimated rate constants for C-H bond cleavage, dissociation of substrate from the Cu(M) site, and, in the case of Y216A, the rate of electron transfer (ET) from Cu(H) to Cu(M). These studies uncover a rate-limiting ET within the solvent-filled interface and lead to a paradigm shift in our understanding of the mononuclear dicopper monooxygenases.
Publication
Journal: Pediatric Pulmonology
October/31/2001
Abstract
Exhaled nitric oxide (eNO) has been used to diagnose asthma in adults and children using either the slow vital capacity method (SVCm) or, in younger children, the tidal breathing method (TBm). Adenosine 5'-monophosphate (AMP) challenge also has been found to be a sensitive and specific test for the diagnosis of asthma. In the present study, we used the AMP provocation concentration that caused wheezing (PCW) to confirm the diagnosis of asthma (PCW < or = 200 mg/mL). We studied 36 children (2-7 years) with mild intermittent asthma, 13 children (3-7 years) with moderate persistent asthma treated with inhaled steroids, 20 nonasthmatic children (2-7 years) with chronic cough and recurrent pneumonia, and 15 healthy children (4-6 years). Expired gas was collected in collection bags by the TBm, and eNO was measured. We evaluated the efficacy of eNO values in diagnosing asthma. The mean eNO level of the mild intermittent asthmatic children (5.6 +/- 0.4 ppb) not receiving inhaled corticosteroids was significantly higher (ANOVA P < 0.0001) than that of the moderate persistent asthmatics who were treated with inhaled steroids, the nonasthmatic children with chronic cough, and the group of healthy children (3.7 +/- 0.6 ppb, P < 0.05; 3.2 +/- 0.3 ppb, P < 0.001; 2.2 +/- 0.2 ppb, P < 0.001, respectively). The points of intersection for sensitivity and specificity curves of eNO to differentiate mild intermittent asthmatics from nonasthmatic children with chronic cough and from healthy children were 77% and 88% for eNO values of 3.8 ppb and 2.9 ppb, respectively. We conclude that eNO collected by the TBm can differentiate steroid-naive young children with intermittent asthma from healthy children, from nonasthmatic children with chronic cough, and from asthmatic children treated with inhaled steroids.
Publication
Journal: Respiratory Care
April/23/2014
Abstract
BACKGROUND
Patterns of pulmonary function tests (PFTs) and flow-volume loops among patients with clinically important tracheobronchomalacia (TBM) are not well described. Small studies suggest 4 main flow-volume loop morphologies: low maximum forced expiratory flow, biphasic expiratory curve, flow oscillations, and notching. We studied common PFT and flow-volume loop patterns among the largest prospective series of patients to date, undergoing clinical evaluation for symptomatic moderate to severe TBM.
METHODS
We conducted a retrospective analysis of prospectively collected data from patients who were referred to our Chest Disease Center from January 2002 to December 2008, with respiratory symptoms that were attributed primarily to TBM. The PFT results of 90 subjects with symptomatic moderate to severe TBM were evaluated.
RESULTS
By PFTs, 40 (44.4%) subjects had an obstructive ventilatory defect, 16 (17.8%) had a definite or highly likely restrictive ventilatory defect, 15 (16.7%) had a mixed defect, and 19 (21.1%) were within normal limits. Among 76 subjects with available flow-volume loops, the most frequent finding was low maximum forced expiratory flow, in 62 (81.6%) subjects, followed by biphasic morphology (15, 19.7%), notched expiratory loop (7, 9.2%), and expiratory oscillations (2, 2.6%). The balance of 13 subjects (17.1%) had no distinctive flow-volume loop abnormality.
CONCLUSIONS
PFTs and flow-volume loops are normal in a substantial number of patients with moderate to severe TBM, and should not be used to decide whether TBM is present or clinically important.
Publication
Journal: European Review for Medical and Pharmacological Sciences
June/13/2011
Abstract
Tuberculosis (TB) can involve any organ system in the body. Extrapulmonary involvement can occur in isolation or along with a pulmonary focus as in the case of patients with disseminated tuberculosis. Tuberculosis meningitis (TBM) is the most severe form of extrapulmonary tuberculosis. TBM a medical emergency, is still a major cause of serious illness in many parts of the world. TBM remains difficult to diagnose, and it is usually due to hematogenous dissemination of the tubercle bacillus. The exact incidence and prevalence are not known. The clinical spectrum is broad and may be non-specific making early diagnosis difficult. Improved outcome requires early recognition and treatment of these conditions. Clinical features included fever for more than 7 days, headache, or neck stiffness. While TBM is a disease of childhood, tuberculomas and spinal tuberculosis are invariably an adult manifestation. In HIV infection, TB is often atypical in presentation, frequently causing extrapulmonary disease, and patients have a high incidence of TBM. Clinical response to antituberculous therapy in all forms of neurotuberculosis is excellent if the diagnosis is made early before irreversible neurological deficit is established. Diagnosis is based on the characteristic clinical picture, neuroimaging abnormalities, cerebrospinal fluid changes and the response to anti-tuberculosis drugs. Diagnosis is best made with lumbar puncture and examination of the cerebrospinal fluid (CSF). Suspect TBM if there is a CSF leucocytosis (predominantly lymphocytes), the CSF protein is raised, and the CSF plasma glucose is <50%. Rapid techniques based on nucleic acid amplification such as PCR are more sensitive and specific as they attempt to detect specific DNA sequences of the organism. The hallmark pathological processes are meningeal inflammation, basal exudates, vasculitis and hydrocephalus. Treatment delay is strongly associated with death and empirical anti-tuberculosis therapy should be started promptly in all patients in whom the diagnosis of TBM is suspected. Corticosteroids reduce the number of deaths. Development of an effective vaccine against tuberculosis hinges on an improved understanding of the human immune response to Mycobacterium tuberculosis (Mtb). The emergence of drug resistant tuberculosis poses a serious threat to the control of this pathogen, and the development of drugs that are active against the resistant strains is vital. Further research into the epidemiology, immune mechanisms, diagnosis, treatment, and prevention of TBM is urgently needed.
Authors
Publication
Journal: Cancer Research
August/24/1989
Abstract
The EL4 lymphoma in C57BL/6 mice was used as a model to examine the effect of progressive tumor growth on a variety of cell mediated cytolytic effector functions which have been shown in other systems to have antitumor potential. The functions examined were those of cytolytic T-lymphocyte, lymphokine activated killer cells, natural killer cells, and tumoricidal macrophage (MO). The kinetics of each function displayed a unique pattern as a consequence of tumor growth, but all were inhibited in animals bearing large tumors (late tumor bearers). In cell mixing experiments it was shown that spleen cells from individual late tumor bearers were suppressive for cytotoxic T-lymphocytes, lymphokine activated killer cells, and splenic MO but not peritoneal MO or splenic natural killer cells. The suppression was nonspecific and was mediated primarily by nonadherent cells and/or their soluble products. Suppression appeared to be mediated, in part, by tumor cells in the spleen since the degree of suppressor activity associated with a particular spleen cell preparation correlated with the number of tumor cells present. Furthermore, the direct addition of viable ascites EL4 cells to response cultures or assays had similar suppressive effects as late TBM spleen cells, i.e., inhibited cytotoxic T-lymphocytes, lymphokine activated killer cells, and splenic MO but had no effect on natural killer cells or peritoneal MO. The mechanism of suppression by ascites EL4 was not determined but it was mediated by viable cells only and not due to contaminating viruses or other microorganisms.
Publication
Journal: Tuberculosis
December/22/2010
Abstract
The first retrospective molecular characterization of Mycobacterium tuberculosis from cerebrospinal fluid of 158 tuberculous meningitis (TBM) in Thailand, collected between 1995 and 2005, was performed by Southern-blot hybridization with an IS6110 probe and spoligotyping on 152 and 147 isolates, respectively. Antituberculous drug susceptibility testing was performed in 149 patients, 118 of whom (79.2%) contained pan-sensitive strains and eight (5.4%) harbored multidrug-resistant M. tuberculosis. IS6110 RFLP typing revealed 110 RFLP patterns with 57.9% of patients infected with the Beijing genotype. This percentage was significantly higher than that in a previous report from pulmonary tuberculosis patients. Fifteen of 18 TBM patients (83%) aged <15 years were infected with Beijing isolates (OR=4.47, p=0.018). There were 40 spoligotypes, with 118 patients (80.3%) being clustered. The biggest cluster, which consisted of 84 patients, was the Beijing spoligotype (57.1%). There were 16 novel spoligotypes from 16 patients compared to the Fourth International Spoligotyping Database, SpolDB4. Sixty-four percent of the patients were male, and the mean age of patients was 33.8 years. Beijing isolates from 2001 to 2005 were found in higher percentages than those from 1995 to 2000, but this difference was not significant (p=0.28).
Publication
Journal: FEMS immunology and medical microbiology
July/21/2002
Abstract
Tanned sheep erythrocytes stabilized with pyruvic aldehyde and glutaraldehyde, called double-aldehyde-stabilized cells, were used to standardize passive hemagglutination assay (PHA) for detection of antibody responses to sonicate extract of Mycobacterium tuberculosis and Cysticercus cellulosae soluble antigens. PHA was performed in the following groups of cerebrospinal fluid (CSF) samples: group I - chronic infections of the central nervous system with the possible diagnosis of tuberculous meningitis (TBM), tuberculoma and neurocysticercosis (NCC) (n=88), and group II - controls which included (a) non-infectious non-neurological conditions (n=30), (b) infectious neurological conditions (n=21) and (c) non-infectious neurological conditions (n=133). PHA could detect anti-mycobacterial antibodies at the sensitivity level of 80.76% with a specificity of 92.4% and anti-cysticercal antibodies with a sensitivity of 100% and specificity of 92.94%. However, in 6.33% (i.e. 14/221) of group I and group II (c) CSFs both anti-mycobacterial and anti-cysticercal antibodies were detected. Immunoblot analysis of CSFs derived from TBM patients reacted predominantly to 120-kDa, 96-kDa, 65-kDa, 38-kDa, 26-kDa, 23-kDa, 19-kDa and 12-14-kDa and 4-6-kDa antigens of M. tuberculosis sonicate extract (MTSE), whilst CSFs of proven NCC reacted to >110-kDa, 96-kDa, 80-kDa, 66-68-kDa, 52-kDa and 26-28-kDa antigens of porcine whole cyst sonicate extract (PCSE). On immunoblot analysis, some of the CSFs of TBM patients were PHA positive for both MTSE and PCSE showed antibody reactivity to 70-kDa and 10-kDa antigens of C. cellulosae. Similarly CSF antibody of some Guillain Barre syndrome and myeloradiculopathy patients reacted with cysticercal antigens. But per se no cross-reactivity between MTSE and anti-cysticercal antibodies and vice-versa were observed. However, findings of this study should alert laboratory personnel especially in endemic areas to be extra careful in interpretation of antibody detection results.
Publication
Journal: Journal of Infectious Diseases
May/11/2017
Abstract
Damaging inflammation is thought to contribute to the high morbidity and mortality of tuberculous meningitis (TBM), but the link between inflammation and outcome remains unclear.
We performed prospective clinical and routine laboratory analyses of a cohort of adult patients with TBM in Indonesia. We also examined the LTA4H promoter polymorphism, which predicted cerebrospinal fluid (CSF) leukocyte count and survival of Vietnamese patients with TBM. Patients were followed for >1 year.
We included 608 patients with TBM, of whom 67.1% had bacteriological confirmation of disease and 88.2% had severe (ie, grade II or III) disease. One-year mortality was 43.7% and strongly associated with decreased consciousness, fever, and focal neurological signs. Human immunodeficiency virus (HIV) infection, present in 15.3% of patients, was associated with higher mortality and different CSF characteristics, compared with absence of HIV infection. Among HIV-uninfected patients, mortality was associated with higher CSF neutrophil counts (hazard ratio [HR], 1.10 per 10% increase; 95% confidence interval [CI], 1.04-1.16), low CSF to blood glucose ratio (HR, 1.16 per 0.10 decrease; 95% CI, 1.04-1.30), CSF culture positivity (HR, 1.37; 95% CI, 1.02-1.84), and blood neutrophilia (HR, 1.06 per 109 neutrophils/L increase; 95% CI, 1.03-1.10). The LTA4H promoter polymorphism correlated with CSF mononuclear cell count but not with mortality (P = .915).
A strong neutrophil response and fever may contribute to or be a result of (immuno)pathology in TBM. Aggressive fever control might improve outcome, and more-precise characterization of CSF leukocytes could guide possible host-directed therapeutic strategies in TBM.
Publication
Journal: Clinical Pharmacology and Therapeutics
May/16/2016
Abstract
Pediatric tuberculous meningitis (TBM) is a highly morbid, often fatal disease. Standard treatment includes isoniazid, rifampin, pyrazinamide, and ethambutol. Current rifampin dosing achieves low cerebrospinal fluid (CSF) concentrations, and CSF penetration of ethambutol is poor. In adult trials, higher-dose rifampin and/or a fluoroquinolone reduced mortality and disability. To estimate optimal dosing of rifampin and levofloxacin for children, we compiled plasma and CSF pharmacokinetic (PK) and outcomes data from adult TBM trials plus plasma PK data from children. A population PK/pharmacodynamic (PD) model using adult data defined rifampin target exposures (plasma area under the curve (AUC)0-24 = 92 mg*h/L). Levofloxacin targets and rifampin pediatric drug disposition information were literature-derived. To attain target rifampin exposures, children require daily doses of at least 30 mg/kg orally or 15 mg/kg intravenously (i.v.). From our pediatric population PK model, oral levofloxacin doses needed to attain exposure targets were 19-33 mg/kg. Our results provide data-driven guidance to maximize pediatric TBM treatment while we await definitive trial results.
Publication
Journal: Cancer Immunology, Immunotherapy
January/3/2013
Abstract
Tumor growth is often accompanied by the accumulation of myeloid cells in the tumors and lymphoid organs. These cells can suppress T cell immunity, thereby posing an obstacle to T cell-targeted cancer immunotherapy. In this study, we tested the possibility of activating tumor-associated myeloid cells to mediate antitumor effects. Using the peritoneal model of B16 melanoma, we show that peritoneal cells (PEC) in tumor-bearing mice (TBM) had reduced ability to secrete nitric oxide (NO) following in vitro stimulation with interferon gamma and lipopolysaccharide, as compared to PEC from control mice. This reduced function of PEC was accompanied by the influx of CD11b(+) Gr-1(+) myeloid cells to the peritoneal cavity. Nonadherent PEC were responsible for most of the NO production in TBM, whereas in naïve mice NO was mainly secreted by adherent CD11b(+) F4/80(+) macrophages. Sorted CD11b(+) Gr-1(-) monocytic and CD11b(+) Gr-1(+) granulocytic PEC from TBM had a reduced ability to secrete NO following in vitro stimulation (compared to naïve PEC), but effectively suppressed proliferation of tumor cells in vitro. In vivo, treatment of mice bearing established peritoneal B16 tumors with anti-CD40 and CpG resulted in activation of tumor-associated PEC, reduction in local tumor burden and prolongation of mouse survival. Inhibition of NO did not abrogate the antitumor effects of stimulated myeloid cells. Taken together, the results indicate that in tumor-bearing hosts, tumor-associated myeloid cells can be activated to mediate antitumor effects.
Publication
Journal: International Journal of Tuberculosis and Lung Disease
January/30/2003
Abstract
OBJECTIVE
A 5-year retrospective study of the performance of the Gen-Probe Amplified Mycobacterium Tuberculosis Direct Test (MTD) for detecting Mycobacterium tuberculosis complex in cerebrospinal fluid (CSF). Patient data from culture-confirmed cases of tuberculous meningitis (TBM) were also analysed.
RESULTS
In total, 311 CSF specimens were tested by the MTD, of which 17 were positive. When compared with culture (gold standard), the sensitivity and specificity of the MTD test were 93.8% and 99.3%, respectively. The positive and negative predictive values for TBM were 88.2%, and 99.7%. Clinical and epidemiological information was requested for all culture-positive TBM patients. These data were used to assess the mortality rate (55.6%) and to determine common factors that could be applied as selection criteria for the appropriate testing of CSF by MTD.
CONCLUSIONS
The study found the MTD test to be a rapid, sensitive and specific test for TBM. A history of immigration from an area endemic for tuberculosis (TB), a history of TB, symptoms of neurological deficits and the results of CSF analyses could be used to appropriately select CSF for MTD testing in order to provide a critical early diagnosis of TBM.
Publication
Journal: Journal of Clinical Microbiology
June/4/2008
Abstract
Although the "gold standard" for diagnosis of tuberculous meningitis (TBM) is bacterial isolation of Mycobacterium tuberculosis, there are still several complex issues. Recently, we developed an internally controlled novel wide-range quantitative nested real-time PCR (WR-QNRT-PCR) assay for M. tuberculosis DNA in order to rapidly diagnose TBM. For use as an internal control calibrator to measure the copy number of M. tuberculosis DNA, an original new-mutation plasmid (NM-plasmid) was developed. Due to the development of the NM-plasmid, the WR-QNRT-PCR assay demonstrated statistically significant accuracy over a wide detection range (1 to 10(5) copies). In clinical applications, the WR-QNRT-PCR assay revealed sufficiently high sensitivity (95.8%) and specificity (100%) for 24 clinically suspected TBM patients. In conditional logistic regression analysis, a copy number of M. tuberculosis DNA (per 1 ml of cerebrospinal fluid) of >8,000 was an independent risk factor for poor prognosis for TBM (i.e., death) (odds ratio, 16.142; 95% confidence interval, 1.191 to 218.79; P value, 0.0365). In addition, the copy numbers demonstrated by analysis of variance statistically significant alterations (P < 0.01) during the clinical treatment course for 10 suspected TBM patients. In simple regression analysis, the significant correlation (R(2) = 0.597; P < 0.0001) was demonstrated between copy number and clinical stage of TBM. We consider the WR-QNRT-PCR assay to be a useful and advanced assay technique for assessing the clinical treatment course of TBM.
Publication
Journal: DMM Disease Models and Mechanisms
May/11/2015
Abstract
Tuberculous meningitis (TBM) is one of the most severe extrapulmonary manifestations of tuberculosis, with a high morbidity and mortality. Characteristic pathological features of TBM are Rich foci, i.e. brain- and spinal-cord-specific granulomas formed after hematogenous spread of pulmonary tuberculosis. Little is known about the early pathogenesis of TBM and the role of Rich foci. We have adapted the zebrafish model of Mycobacterium marinum infection (zebrafish-M. marinum model) to study TBM. First, we analyzed whether TBM occurs in adult zebrafish and showed that intraperitoneal infection resulted in granuloma formation in the meninges in 20% of the cases, with occasional brain parenchyma involvement. In zebrafish embryos, bacterial infiltration and clustering of infected phagocytes was observed after infection at three different inoculation sites: parenchyma, hindbrain ventricle and caudal vein. Infection via the bloodstream resulted in the formation of early granulomas in brain tissue in 70% of the cases. In these zebrafish embryos, infiltrates were located in the proximity of blood vessels. Interestingly, no differences were observed when embryos were infected before or after early formation of the blood-brain barrier (BBB), indicating that bacteria are able to cross this barrier with relatively high efficiency. In agreement with this observation, infected zebrafish larvae also showed infiltration of the brain tissue. Upon infection of embryos with an M. marinum ESX-1 mutant, only small clusters and scattered isolated phagocytes with high bacterial loads were present in the brain tissue. In conclusion, our adapted zebrafish-M. marinum infection model for studying granuloma formation in the brain will allow for the detailed analysis of both bacterial and host factors involved in TBM. It will help solve longstanding questions on the role of Rich foci and potentially contribute to the development of better diagnostic tools and therapeutics.
Publication
Journal: Antimicrobial Agents and Chemotherapy
May/8/2005
Abstract
The in vitro activity of tebipenem (TBM), a new oral carbapenem antibiotic, against Streptococcus pneumoniae clinical isolates (n = 202) was compared with those of 15 reference agents. The isolates were classified into five genotypic classes after PCR identification of abnormal pbp1a, pbp2x, and pbp2b genes: (i) penicillin-susceptible S. pneumoniae (PSSP) isolates with no abnormal pbp genes (n = 34; 16.8%), (ii) genotypic penicillin-intermediate S. pneumoniae (gPISP) isolates with only an abnormal pbp2x gene [gPISP (2x)] (n = 48; 23.8%), (iii) gPISP isolates with abnormal pbp1a and pbp2x genes (n = 32; 15.8%), (iv) gPISP isolates with abnormal pbp2x and pbp2b genes (n = 16; 7.9%), and (v) genotypic penicillin-resistant S. pneumoniae (gPRSP) isolates with three abnormal pbp genes (n = 72; 35.6%). The majority of the strains tested had mefA (n = 59; 29.2%) or ermB (n = 91; 45%) gene-mediating macrolide resistance. For these isolates the MIC at which 90% of isolates are inhibited was significantly lower for TBM than for the reference oral antibiotics, as follows: 0.002 microg/ml for PSSP, 0.004 mug/ml for gPISP (2x), 0.016 microg/ml for gPISP (isolates with abnormal pbp1a and pbp2x genes and isolates with abnormal pbp2x and pbp2b genes), and 0.063 microg/ml for gPRSP. In addition, TBM showed excellent bactericidal activity against gPRSP isolates, which exhibited a 3-log(10) decrease within 2 h when they were incubated with a concentration greater than or equal to the MIC. Inhibition of cell wall synthesis toward the long axis and subsequent cell lysis were observed by scanning electron microscopy after a short-term exposure to TBM, unlike the effects seen with cephalosporins. These data suggest that TBM has potent activity against multidrug-resistant S. pneumoniae, the causative pathogen of community-acquired respiratory tract infections.
Publication
Journal: Dementia and Geriatric Cognitive Disorders
August/25/2013
Abstract
OBJECTIVE
The clinical syndromes of frontotemporal lobar degeneration include behavioral variant frontotemporal dementia (bvFTD) and semantic (SV-PPA) and nonfluent variants (NF-PPA) of primary progressive aphasia. Using magnetic resonance imaging (MRI), tensor-based morphometry (TBM) was used to determine distinct patterns of atrophy between these three clinical groups.
METHODS
Twenty-seven participants diagnosed with bvFTD, 16 with SV-PPA, and 19 with NF-PPA received baseline and follow-up MRI scans approximately 1 year apart. TBM was used to create three-dimensional Jacobian maps of local brain atrophy rates for individual subjects.
RESULTS
Regional analyses were performed on the three-dimensional maps and direct comparisons between groups (corrected for multiple comparisons using permutation tests) revealed significantly greater frontal lobe and frontal white matter atrophy in the bvFTD relative to the SV-PPA group (p < 0.005). The SV-PPA subjects exhibited significantly greater atrophy than the bvFTD in the fusiform gyrus (p = 0.007). The NF-PPA group showed significantly more atrophy in the parietal lobes relative to both bvFTD and SV-PPA groups (p < 0.05). Percent volume change in ventromedial prefrontal cortex was significantly associated with baseline behavioral symptomatology.
CONCLUSIONS
The bvFTD, SV-PPA, and NF-PPA groups displayed distinct patterns of progressive atrophy over a 1-year period that correspond well to the behavioral disturbances characteristic of the clinical syndromes. More specifically, the bvFTD group showed significant white matter contraction and presence of behavioral symptoms at baseline predicted significant volume loss of the ventromedial prefrontal cortex.
Publication
Journal: Journal of clinical medicine research
July/13/2011
Abstract
BACKGROUND
Tuberculosis kills five lakh patients in India every year, out of which 7-12 % are with meningeal involvement. Delay in its diagnosis and in initiation of treatment results in poor prognosis and sequlae in up to 25% of cases. The aim of the present study is to look for a simple, rapid, cost effective, non-invasive and fairly specific test in differentiating tubercular etiology from other causes.
METHODS
Forty patients between the age of 6 - 24 months attending hospital with symptoms and signs of meningitis were selected and divided into two groups: tubercular and non-tubercular, depending upon the accepted criteria. CSF was drawn and ADA estimated.
RESULTS
Out of 19 tubercular patients, 18 had CSF ADA at or above the cutoff value while one had below. Out of 21 non-tuberculous patients, two had ADA levels at or above the cutoff value while 19 had below this value. Results of our study indicate that ADA level estimation in CSF is not only of considerable value in the diagnosis of TBM, CSF ADA level 10 U/L as a cutoff value exhibited 94.73% sensitivity and 90.47% specificity in differentiating tuberculous from non-tuberculous meningitis; it also has 90.00% positive predictive value and 95.00% negative predictive value.
CONCLUSIONS
It can be concluded that ADA estimation in CSF is not only simple, inexpensive and rapid but also fairly specific method for making a diagnosis of tuberculous etiology in TBM, especially when there is a dilemma of differentiating the tuberculous etiology from non-tuberculous ones. For this reason ADA estimation in TBM may find a place as a routine investigation.
BACKGROUND
Cerebrospinal fluid; Adenosine deaminase; Tuberculous meningitis.
Publication
Journal: Microbiology spectrum
July/4/2017
Abstract
Central nervous system tuberculosis (CNS-TB) takes three clinical forms: meningitis (TBM), intracranial tuberculoma, and spinal arachnoiditis. TBM predominates in the western world and presents as a subacute to chronic meningitis syndrome with a prodrome of malaise, fever, and headache progressing to altered mentation and focal neurologic signs, followed by stupor, coma, and death within five to eight weeks of onset. The CSF formula typically shows a lymphocytic pleocytosis, and low glucose and high protein concentrations. Diagnosis rests on serial samples of CSF for smear and culture, combined with CSF PCR. Brain CT and MRI aid in diagnosis, assessment for complications, and monitoring of the clinical course. In a patient with compatible clinical features, the combination of meningeal enhancement and any degree of hydrocephalus is strongly suggestive of TBM. Vasculitis leading to infarcts in the basal ganglia occurs commonly and is a major determinant of morbidity and mortality. Treatment is most effective when started in the early stages of disease, and should be initiated promptly on the basis of strong clinical suspicion without waiting for laboratory confirmation. The initial 4 drug regimen (isoniazid, rifampin, pyrazinamide, ethambutol) covers the possibility of infection with a resistant strain, maximizes antimicrobial impact, and reduces the likelihood of emerging resistance on therapy. Adjunctive corticosteroid therapy has been shown to reduce morbidity and mortality in all but late stage disease.
Publication
Journal: IEEE Transactions on Medical Imaging
February/28/2016
Abstract
Sparse systems are usually parameterized by a tuning parameter that determines the sparsity of the system. How to choose the right tuning parameter is a fundamental and difficult problem in learning the sparse system. In this paper, by treating the the tuning parameter as an additional dimension, persistent homological structures over the parameter space is introduced and explored. The structures are then further exploited in drastically speeding up the computation using the proposed soft-thresholding technique. The topological structures are further used as multivariate features in the tensor-based morphometry (TBM) in characterizing white matter alterations in children who have experienced severe early life stress and maltreatment. These analyses reveal that stress-exposed children exhibit more diffuse anatomical organization across the whole white matter region.
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