Cerebrospinal fluid analysis, predictors of bacterial meningitis: a study in 312 patients with suspected meningial infection

Objective： Patients with cerebrospinal fluid （CSF） pleocytosis are routinely admitted to the hospital and treated with parenteral antibiotics, although few have bacterial meningitis （BM）. The aim of this study was to evaluate predictors to differentiate BM from aseptic meningitis （ASM）. Methods：The study was conducted in Razi hospital, a training center affiliated to Ahvaz Joundishapoor University of Medical Sciences in Iran. and all patients were 18 years old or above and were treated in the hospital between 2003 and 2007. Data of those who had meningitis, tested as CSF pleocytosis but had not received antibiotic treatment before lumbar puncture were retrospectively analyzed. Results： Among 312 patients with CSF pleocytosis, two hundred fifteen （68.9%） had BM and ninety seven （31.1%） had ASM. The mean age for patients with BM was （34.7 - 17.7） years （P = 0.22, NS）. Sixty percent of the BM cases and 61.2% of the ASM cases occurred in men （ P = 0.70, NS）. We identified the following predictors of BM： CSF-WBC count 〉 100 per micro liter, CSF-glucose level 〈 40 mg/dL, CSF-protein level 〉 80 mg/dL. Sensitivity, specificity, PPV, NPV of these predictors, and LR for BM are 86.5% ,52.6% ,80.2% , 63.7% and 104. 1 for CSF-WBC count and 72.1% , 83.5% , 90.6% ,57.4% and 164.2% for CSF glucose, and 49.7% , 91.8% , 93.4% ,45. 2% and 104.5% for CSF protein. Conclusion：The CSF WBC count should not be used alone to rule out bacterial meningitis. When it is combined with other factors such as CSF glucose and protein improved decision making in patients with suspected BM may occur.     

A decision tree-based approach for determining low bone mineral density in inflammatory bowel disease using WEKA software

BACKGROUND: Decision tree classification is a standard machine learning technique that has been used for a wide range of applications. Patients with inflammatory bowel disease (IBD) are at increased risk of developing low bone mineral density (BMD). This study aimed at developing a new approach to select truly affected IBD patients who are indicated for densitometry, hence, subjecting fewer patients for bone densitometry and reducing expenses. MATERIALS AND METHODS: Simple decision trees have been developed by means of WEKA (Waikato Environment for Knowledge Analysis) package of machine learning algorithms to predict factors influencing the bone density among IBD patients. The BMD status was the outcome variable whereas age, sex, duration of disease, smoking status, corticosteroid use, oral contraceptive use, calcium or vitamin D supplementation, menstruation, milk abstinence, BMI, and levels of calcium, phosphorous, alkaline phosphatase, and 25-OH vitamin D were all attributes. RESULTS: Testing showed the decision trees to have sensitivities of 65.7-82.8%, specificities of 95.2-96.3%, accuracies of 86.2-89.8%, and Matthews correlation coefficients of 0.68-0.79. Smoking status was the most significant node (root) for ulcerative colitis and IBD-associated trees whereas calcium status was the root of Crohn's disease patients' decision tree. CONCLUSION: BD specialists could use such decision trees to reduce substantially the number of patients referred for bone densitometry and potentially save resources.     

Immunogenicity of recombinant hepatitis B virus vaccine in patients with and without chronic hepatitis C virus infection： A case-control study

AIM： To compare the response of standard hepatitis B virus （HBV） vaccination between patients with chronic hepatitis C virus （HCV） infection and healthy individuals. METHODS： This is a prospective case-control study. A total of 38 patients with chronic HCV infection and 40 healthy controls were included. Vaccination was performed by injection of 20μg recombinant HBsAg into the deltoid muscle at mo 0,1 and 6. Anti-HBs concentration was determined 3 mo after the last dose and compared between the two groups. The response pattern was characterized as （1） high-response when the anti-HBs antibody titer was 〉 100 IU/L, （2） low-response when the titer was 10-100 IU/L. and （3） no-response when the titer was 〈 10 IU/L. RESULTS： In the patient group, there were 10/38 （26.3%） non-responders, 8/38 （21.1%） Iow-responders and 20/38 （52.6%） high-responders. The corresponding values in the control group were 2/40 （5.0%）, 7/40 （17.5%） and 31/40 （77.5%）, respectively. The response pattern was statistically different between the two groups. In multivariate analysis, smoking was a significant confounder, while HCV infection lost its significant correlation with lower antibody response. CONCLUSION： Patients with chronic HCV infection tend to respond weakly to HBV vaccination compared to healthy individuals, though this correlation is not independent according to multivariate analysis.     

Alterations of telomere length in human brain tumors

Telomeres at the ends of human chromosomes consist of tandem hexametric (TTAGGG)n repeats, which protect them from degradation. At each cycle of cell division, most normal somatic cells lose approximately 50–100 bp of the terminal telomeric repeat DNA. Precise prediction of growth and estimation of the malignant potential of brain tumors require additional markers. DNA extraction was performed from the 51 frozen tissues, and a non-radioactive chemiluminescent assay was used for Southern blotting. One sample t-test shows highly significant difference in telomere length in meningioma and astrocytoma with normal range. According to our results, higher grades of meningioma and astrocytoma tumors show more heterogeneity in telomere length, and also it seems shortening process of telomeres is an early event in brain tumors.     

CYP2B6 (c.516G→T) and CYP2A6 (*9B and/or *17) polymorphisms are independent predictors of efavirenz plasma concentrations in HIV-infected patients

AIMS

Interindividual variability in efavirenz pharmacokinetics is not entirely explained by the well-recognized CYP2B6 516G→T single nucleotide polymorphism. The aim of this study was to determine whether polymorphisms in the CYP2A6 gene can be used to enhance the predictability of efavirenz concentrations in human immunodeficiency virus (HIV)-infected native African patients.

METHODS

Mid-dose efavirenz plasma concentrations were determined at 4 and 8 weeks following initiation of antiretroviral therapy in 65 HIV-infected Ghanaian patients. Selected CYP2B6 and CYP2A6 genotypes were determined by commercial 5′-nuclease assays. Relationships between averaged 4- and 8-week mid-dose efavirenz concentrations, demographic variables and genotypes were evaluated by univariate and multivariate statistical approaches including gene–gene interactions.

RESULTS

CYP2B6 c.516G→T, CYP2B6 c.983T→C, CYP2A6*9B and CYP2A6*17 allele frequencies were 45, 4, 5 and 12%, respectively. Rifampicin therapy, gender, age and body mass index had no significant influence on efavirenz mid-dose concentrations. Median efavirenz concentrations were more than five times higher (P < 0.001) in patients with CYP2B6 c.516TT genotype compared with GG and GT genotypes. Although none of the CYP2A6 genotypes was associated with altered efavirenz concentrations individually, CYP2A6*9B and/or CYP2A6*17 carriers showed a 1.8 times higher median efavirenz concentration (P= 0.017) compared with noncarriers. Multiple linear regression analysis indicated that the CYP2B6 c.516G→T polymorphism and CYP2A6 slow-metabolizing variants accounted for as much as 36 and 12% of the total variance in efavirenz concentrations, respectively.

CONCLUSIONS

Our findings support previous work showing efavirenz oxidation by CYP2A6, and suggest that both CYP2A6 and CYP2B6 genotyping may be useful for predicting efavirenz plasma concentrations.     

Effect of parental morphine addiction on hippocampal long-term potentiation in rats offspring

Attention to addiction of women alone for fetus and infant's health has caused the possible role of father's status was less considered, while some developmental impairments including decrease of liter size, weight loss, congenital deficiencies, behavioral disorders, and learning and memory impairments in offspring with addicted father have been reported. In this study the effects of addiction of one or both parents to morphine on male and female offspring hippocampal long-term potentiation (LTP), were assessed. One hundred twenty female and 48 male rats (4-5 months, 250-270 g) were used. Forty females and 16 males were addicted by oral administration of morphine (32 mg/kg twice daily) for 5 days before mating. Then each two males with five females were housed (coupled) per cage as five groups for coupling: (A) addicted females+5% dextrose males (add.F); (B) addicted males+5% dextrose females (add.M); (C) addicted females+addicted males (add.MF); (D) 5% dextrose females+intact males (dex.F); (E) 5% dextrose males+intact females (dex.M). In puberty offspring LTP was induced in hippocampal dentate gyrus by stimulation of perforant path (pp). Changes of population spikes (PS) amplitude and LTP slope at 0, 5, 30, 60 and 120 min were evaluated. Slope of LTP at 30, 60 and 120 min, and amplitude of PS at 60 and 120 min in add.F and add.M offspring were significantly lower than dextrose groups (P<0.01). LTP slope and PS amplitude of male and female offspring did not different between add.F and add.M groups. Our results suggest that both parental and paternal addiction to morphine may cause memory deficiency through reduction of LTP in hippocampus.