A comparative study of hepatitis B virus X protein mutants K130M, V131I and KV130/131MI to investigate their roles in fibrosis, cirrhosis and hepatocellular carcinoma.

Hepatitis B virus (HBV) genomic mutations A1762T, G1764A and AG1762/1764TA cause production of HBV X protein (HBx) mutants, namely K130M, V131I and KV130/131MI. These mutations are important biomarkers for the development of cirrhosis and hepatocellular carcinoma (HCC) in chronic HBV patients. This study comparatively analyses the impact of intracellular expression of HBx mutants on HCC cell line Huh7. It was found that expression of KV130/131MI induced: cell proliferation, altered expression of cell cycle regulatory genes in favour of cell proliferation, intracellular reactive oxygen species (ROS) production and mitochondrial depolarization. KV130/131MI may be directly involved in host cell proliferation and hepatocarcinogenesis via altering expression of cell cycle regulatory genes. KV130/131MI may also play pivotal roles in fibrosis and cirrhosis via inducing ROS production and mitochondrial depolarization. Furthermore, these might be the possible reasons for higher occurrence of AG1762/1764TA as compared to A1762T and G1764A in cirrhosis and HCC patients.

Cerebrospinal fluid procalcitonin as a biomarker of bacterial meningitis in neonates.

OBJECTIVE: The objective of the study was to study the performance of cerebrospinal fluid (CSF) procalcitonin as a marker for bacterial meningitis in neonates, and to determine its optimal 'cutoff' in CSF that can be called significant for the diagnosis. STUDY DESIGN: Neonates qualifying for lumbar puncture were prospectively studied. Procalcitonin and established CSF parameters were recorded. RESULTS: At a cut-off value of 0.33 ng ml-1, CSF procalcitonin had a sensitivity of 0.92, specificity of 0.87, with positive and negative likelihood ratios of 7.13 and 0.092, respectively. The area under the curve for different CSF parameters was: 0.926 (0.887 to 0.964) (P<0.001) for procalcitonin, 0.965 (0.956 to 0.974) for total leukocyte count, 0.961 (0.94 to 0.983) for neutrophil count, 0.874 (0.825 to 0.923) for protein, 0.946 (0.914 to 0.978) for sugar and 0.92 (0.955 to 0.992) for CSF:serum sugar ratio. The lumbar puncture was traumatic in 36 (21.4%) patients; out of these 15 (41.7%) had bacterial meningitis and 21 (58.3%) had no meningitis. In traumatic lumbar tap group, the median (IQR) CSF procalcitonin in patients with and without meningitis was 1.41 (0.32-3.42) ng/ml and 0.21(0.20-0.31) ng/ml respectively (p<0.05). CONCLUSIONS: Procalcitonin measurement has diagnostic efficiency similar to the established CSF markers. Routine assessment of procalcitonin in clean non-contaminated CSF may not yield additional information, but it may have clinical utility in situations where diagnosis of meningitis is in dilemma, as in the case of blood contamination of CSF in traumatic lumbar punctures.

In vivo characterisation of two Australian isolates of Marek's disease virus including pathology, viral load and neuropathotyping based on clinical signs.

OBJECTIVE: To evaluate the pathogenicity of Australian Marek's disease virus (MDV) isolate MPF23 (1985) against the reference strain MPF57 based on pathology, viral load and neuropathotyping on the basis of clinical signs. PROCEDURE: Two MDV challenge isolates (MPF57 or MPF23) were administered to unvaccinated specific-pathogen free (SPF) layer chicks on day 5 after hatch at three challenge doses (500, 2000 or 8000 plaque-forming units (pfu)/chick). Mortality, body weight, immune organ weights, MDV load in peripheral blood lymphocytes (PBL) and clinical signs were measured to 56 days post challenge (dpc). RESULTS: MPF23 was the more pathogenic of the two viruses, inducing higher mortality (81% vs 62%) and incidence of MD lesions (100% vs 76%). MPF23 induced earlier, more sustained and more severe neurological signs in the period 26-56 dpc. However, there were few differences during the 0-23 dpc used in the neuropathotyping classification under test. The observed pattern during this earlier period classified both viruses as neuropathotype B, consistent with a very virulent pathotype. MDV load in PBL at 7 and 44 dpc did not differ between virus isolates, but the load at 7 dpc was significantly and negatively associated with time to euthanasia or death. CONCLUSION: MPF23 appears to be as, or more, virulent than the MDV strains isolated over the subsequent two decades. The neuropathotyping system developed in the USA did not clearly differentiate between the two isolates under test; however, extension of the period of assessment of clinical signs beyond 26 dpc did reveal clear differences.

Elimination and phase II metabolism of ethanol in camels after intravenous administration.

Ethanol elimination was studied in camels (n=8) after a single bolus intravenous dose of 0.1g/kg bodyweight (BW). Blood samples were then collected at set intervals. Ethanol and ethyl glucuronide (EtG) in blood were analysed by validated static headspace gas chromatography-mass spectrometry and liquid chromatography-mass spectrometry (LC-MS) methods, respectively. Blood-ethanol concentration-time profiles were plotted for each camel and these were evaluated. A simple linear regression model was fitted to the selected data points and the slope of the fitted line was used to estimate the elimination rate, the distribution factor and turnover rate, which were 5.15 mg/dL blood/h, 0.55 L/kg and 0.028 g/h/kg, respectively. Blood EtG concentration-time profiles were also plotted for each camel. The elimination half-life of EtG, estimated by linear regression (using the values obtained after ethanol was completely eliminated) was 2.18 h. The theoretical initial blood concentration of EtG (C(0)), obtained by extrapolation to time zero was 23.4 µg/dL. The results will be useful in monitoring alcohol doping in camels using either parent drug or metabolite.

Allelic variations in CYP2D6 gene and susceptibility to cervical cancer.

Epidemiological studies have identified a number of risk factors that contribute to the development of cervical cancer precursors and cervical cancer. These include infection with certain oncogenic types of human papillomaviruses (HPVs) and other socio-economic factors. Tobacco smoking is an independent risk-factor for cervical neoplasia. It has been found that polymorphism at loci that encode carcinogen-metabolizing enzyme such as cytochrome P450 2D6 (CYP2D6) catalyzing the detoxification of carcinogens may determine susceptibility to cervical cancer. Therefore, it is likely that an understanding of these allelic differences is important for determining an individual's risk of cancer and susceptibility to potentially toxic agents. The aim of the present study was to elucidate the role of CYP2D6 polymorphism and susceptibility to squamous cell carcinoma of the uterine cervix in Indian population. Therefore, the genotype frequencies at this locus in females suffering with low-grade CIN, high-grade CIN and squamous cell carcinoma were compared. The control group consisted of 77 females with normal cervical cytology and the cases comprised of 61 mild/moderate dysplasia, 48 severe dysplasia and 45 cases of squamous cell carcinoma of uterine cervix. The individuals were divided into poor metabolizers (PM) and extensive metabolizers (EM) on the basis of their ability to metabolize certain drugs and carcinogens. Comparison of the frequency distribution for the combination of CYP2D6 EM genotype and smoking between mild/moderate and severe dysplasia was statistically significant (p=0.047) suggesting that women with cervical intraepithelial neoplasia I/II (CIN I/ CIN II) and CYP2D6 EM genotype who smoke appears to have more chances for the lesions to progress to CIN III. Whereas, frequency distribution for the same combination between severe dysplasia and squamous cell carcinoma failed to attain any statistical significance suggesting that CIN III with CYP2D6 EM genotype has less chance to progress to cervical cancer. Increased frequency of CYP2D6 EM and tobacco smoking show strong association with CIN III, indicating that not all lesions with the histopathological high grade CIN are premalignant. Conversely some squamous cell carcinomas may not be preceded by CIN.

The disposition of theophylline in camels after intravenous administration.

The pharmacokinetics of theophylline were determined after an intravenous (i.v.) dose of 2.36 mg/kg in six camels and 4.72 mg/kg body weight in three camels. The data obtained (median and range) for the low and high dose, respectively, were as follows: the distribution half-lives (t1/2 alpha) were 1.37 (0.64-3.25) and 2.66 (0.83-3.5) h, the elimination half-lives (t1/2 beta) were 11.8 (8.25-14.9) and 10.4 (10.0-13.5) h, the steady state volumes of distribution (Vss) were 0.88 (0.62-1.54) and 0.76 (0.63-0.76) L/kg, volumes of the central compartment (Vc) were 0.41 (0.35-0.63) and 0.51 (0.36-0.52) L/kg, total body clearances (Clt) were 62.3 (39.4-97.0) and 50.2 (47.7-67.4) mL/h.kg body weight and renal clearance (Vr) for the low dose was 0.6 (0.42-0.96) mL/h.kg body weight. There was no significant difference in the pharmacokinetic parameters between the two doses. Theophylline protein binding at a concentration of 5 micrograms/mL was 32.2 +/- 3.3%. Caffeine was identified as a theophylline metabolite but its concentration in serum and urine was small. Based on the pharmacokinetic values obtained in this study, a dosage of 7.5 mg/kg body weight administered by i.v. injection at 12 h intervals can be recommended. This dosing regimen should achieve an average steady state serum concentration of 10 micrograms/mL with peak serum concentration not exceeding 15 micrograms/mL.