Genetic Testing for Huntington's Disease in Parkinsonism

The study was conducted to find out Huntington's disease (HD) by genetic analysis from those presenting with parkinsonism in the Neurology department of Mymensingh Medical College & Hospital. A sample of about 5ml blood was collected by veni puncture in EDTA tube with informed consent from 9 patients & 7 healthy individuals after approval of the institutional ethics committee for genetic study. The neurological disorder along with a complete history and physical findings were recorded in a prescribed questionnaire by the neurologists of Mymensingh Medical College & Hospital. Extraction of genomic DNA from the venous blood using FlexiGene DNA kit (Qiagen, Japan) was performed in Faculty of Veterinary Science, Bangladesh Agricultural University, Mymensingh, Bangladesh. The extracted DNA was stored and accumulated and then these DNA were sent to Division of Clinical Genetics, Department of Medical Genetics, Osaka University Medical School, Suita, Osaka 565 0871, Japan for PCR and further analysis. PCR amplification of the CAG repeat in the 1T15 gene was performed with primers HD1 and HD3. HD PCR products revealed the DNA product of about 110bp (no. of CAG repeats=21) to 150bp (no. of CAG repeats=34) in both healthy individual and suspected PD patient DNA.

Inhibition of acid production in Streptococcus mutans R9 by formic acid

Both lactic and acetic acids cause mixed inhibition of acid production in mutans streptococci. This inhibition is partly irreversible due to cell death, an important factor when considering acidogenicity and aciduricity of these organisms, and their role in the caries process. Other monocarboxylic end-products may be present and may also be important inhibitors of acid production in dental plaque. This study considered the effects of varying concentrations of the end-product formic acid on acid production rates in Streptococcus mutans R9, measured using the pH-stat. Undissociated formic acid caused mixed inhibition with constants of Kiu (uncompetitive) of 6.07 +/- 1.27 mmol-1 and Kic (competitive) of 0.2 +/- 0.11 mmol l-1. Inhibition was found to be fully reversible, with no loss of cell viability. It is concluded that at those concentrations found in vivo, formate is not a significant inhibitor of acid production by S. mutans in dental plaque at any time, and is not important in determining the acidogenicity or aciduricity of this organism.