On the developmental properties and tissue interactions of hexokinase

The interactions of the isozymes of hexokinase with cellular structure have been studied in the major tissues of the mouse during development. Overall, these data provide a clear indication that interactions between hexokinase and cellular structure are appreciable in all major tissues and at all stages of development, and an analysis of the isozyme status of the enzyme in both soluble and bound compartments has been effected. Further evidence in support of the already well documented interaction of hexokinase I to subcellular material in adult brain and kidney tissues is provided and extended to show that such interactions are extensive in both these tissues throughout development. In addition, evidence is provided that considerable hexokinase II activity is present in mouse foetal tissues in both the soluble and bound fractions and this isozyme is also shown to be the predominant "bound" form of the enzyme in adult skeletal muscle. By contrast, hexokinase III and IV are shown to be largely located in the cytosolic fraction of liver. The metabolic implications of these enzyme-structural interactions during development are discussed, as is the possibility of a functional linkage between hexokinase, which is bound to the mitochondria, and other enzymic components of the glycolytic sequence.     

Ethical considerations in presymptomatic testing for variant CJD

Variant Creutzfeldt-Jakob disease (vCJD) is a fatal, transmissible, neurodegenerative disorder for which there is currently no effective treatment. vCJD arose from the zoonotic spread of bovine spongiform encephalopathy. There is now compelling evidence for human to human transmission through blood transfusions from presymptomatic carriers and experts are warning that the real epidemic may be yet to come. Imperatives exist for the development of reliable, non-invasive presymptomatic diagnostic tests. Research into such tests is well advanced. In this article the ethical implications of the availability of these tests are elaborated and comparisons drawn with predictive genetic testing for Huntington's disease and screening for HIV. Paramount to considerations is the issue of whom to test, weighing up respect for personal autonomy against obligations to benefit and protect society. A paradigm is proposed similar to that used for HIV screening but with unique features: compulsory testing of all blood/organ donors and individuals undergoing surgery or invasive procedures who have a significant risk of disease transmission.     

Real Time-PCR HBV-DNA Analysis: Significance and First Experience in Armed Forces

Background

HBV DNA quantitation is used extensively world wide for the diagnosis and monitoring of treatment of Hepatitis B virus (HBV) infection. However, it has still to be popular in India. The aim of this study was to quantitate HBV – DNA by Real time – PCR method in Hepatitis B and in immuno-compromised patients, to compare the results with HBeAg detection and to monitor the response to therapy of chronic Hepatitis B patients to antivirals.

Methods

Ninety one serum samples of Hepatitis group of patients (all HBsAg positive), 41 samples from immuno-compromised patients (all HBsAg negative) and 49 patients of Chronic Hepatitis B group (all HBsAg positive) were the subjects of this first ever study in Armed Forces. Twenty serum samples from healthy volunteers and non-hepatitis B patients served as negative controls. The amplification detection was carried out in a Rotor-Gene 2000-sequence detector

Results

Amongst Hepatitis B group, 33% (30/91) of the samples were positive for HBV-DNA and 26% (24/91) of samples were positive for HBeAg. In the immuno-compromised group of patients 14.6% (6/11) of samples were positive for HIV-DNA and 9.7% (4/41) were positive for HBeAg. Of the Chronic Hepatitis B patients on treatment, all (100%) were positive by HBV-DNA, whereas 29/49 (59.2%) were positive by HBeAg before treatment. After treatment with antivirals, 06/49 (12.2%) were positive by both tests and 11/49 (22.5%) were positive only by HBV-DNA. 32/49 (65.3%) patients became negative serologically after therapy.

Conclusion

HBeAg status did not necessarily reflect HBV-DNA level in the serum, as 10/91 (11%) in the Hepatitis B group, 2/41 (4.9%) in the immuno compromised group and 20/49 (40.8%) patients in the Chronic Hepatitis B group were positive for HBV-DNA but negative for HBeAg. HBV-DNA was not found to be positive amongst any of the negative controls. Real time – PCR is a sensitive and reproducible assay for HBV-DNA quantitation and may be started in Armed Forces referral centers in the near future.Key Words: Real time – PCR, Chronic Hepatitis B, HBV – DNA, Antivirals     

A new method for objective identification and measurement of airway lumen in paediatric flexible videobronchoscopy

BACKGROUND: Accurate measurements of airway and lesion dimensions are important to the developmental progress of paediatric bronchoscopy. The malacia disorders are an important cause of respiratory morbidity in children, but no methods are currently available to measure these lesions or the airway lumen accurately. A new measurement technique is described here. METHODS: The magnification power of a paediatric videobronchoscope was defined and a simple and user friendly computer based program (Image J) was used to develop an objective technique (colour histogram mode technique, CHMT) for measurement of the airway lumen. RESULTS: In vivo intra-observer and inter-observer repeatability coefficients for repeated area measurements from 28 images using the Bland-Altman method were 0.9 mm2 and 1.6 mm2, respectively. The average intraclass correlation coefficient for repeated measurements of area was 0.93. In vitro validation measurements using a 2 mm diameter tube resolved radii measurements to within 0.1 mm (coefficient of variability 8%). An "acceptable result" was defined in 92% of 734 images completed with the CHMT alone and 8% with its modification. The success rate for two of three images being within 10% of each other's area was 100%. Measurements of cricoid cross sectional areas from 116 patients compared with expected airway areas for age derived from endotracheal tube sizes were comparable. CONCLUSIONS: The CHMT method of identifying and measuring airway dimensions is objective, accurate, and versatile and, as such, is important to the future development of flexible videobronchoscopy.