Effect of low lysine diet on rat protein metabolism.

Prolonged lysine deficiency resulted in inhibition of growth of the rat and in lowered levels of albumin and beta-globulins, but not of total liver proteins. The apparent incorporation of [3H]lysine into total and chromosomal liver proteins, however, was increased in lysine deficient rats relative to pair-fed controls. The concentration of free lysine in neither serum nor liver was altered in lysine deficient rats. The specific radioactivity of liver free lysine 2 hours after administration of [3H]lysine was noticeably elevated in the deficient rats. However, when the pool of liver free lysine is considered, synthesis of all proteins studied was inhibited. The largest inhibitory effect was seen in serum albumin and total liver protein synthesis. Inhibition of snythesis of nuclear chromatin protein was less pronounced. The data indicate an adaptive mechanism operates to preserve liver lysine in rats fed lysine deficient diets for a prolonged period. In spite of retention of lysine, the synthesis of liver and serum proteins was inhibited.     

Dry beveling micropipettes using a computer hard drive

It is sometimes useful in electrophysiological recordings to try various micropipette profiles in order to determine which tip works best in a given experiment. A pipette puller can be used to pull very sharp or blunt pipettes, and to fire polish tips for whole cell patch recordings. Broken tip pipettes can be "bumped" to an acceptable tip diameter under a microscope. However, it may be difficult to rationalize the purchase of a commercial beveling machine simply to test whether beveled pipettes are best for recording intracellularly from the cell types of interest. Presented here are methods that use a surplus computer hard drive to reproducibly dry bevel glass micropipettes. Compared to sharp or broken tip electrodes, pipettes dry beveled with this simple system are superior for making intracellular recordings from cichlid Mauthner neurons. Preliminary data obtained with this inexpensive apparatus may allow investigators to successfully justify the purchase of a commercial beveler.     

Hepatitis C Treatment Eligibility and Comorbid Medical Illness in Methadone Maintenance (MMT) and Non-MMT Patients: A Case-Control Study

ABSTRACT

Comorbid medical illness is common in patients with chronic hepatitis C (HCV) infection and in methadone treatment (MMT) patients, yet little is known about the impact of medical illness on HCV treatment eligibility. Medical illness and HCV treatment eligibility were compared in a case-control study of 80 MMT patients entering an HCV treatment trial and 80 matched non-MMT patients entering HCV treatment in a gastroenterology clinic. 91% of MMT and 85% of non-MMT patients had chronic medical conditions. Despite similar medical severity ratings, a significantly higher proportion (77%) of non-MMT patients were eligible for HCV treatment than were MMT patients (56%) (p < .01). Specific comorbid medical and psychiatric illness led to ineligibility in only 18% of MMT and 16% of non-MMT patients. However, failure to complete the medical evaluation process was significantly (p < .001) more likely to cause ineligibility among MMT patients (19%) than non-MMT patients (0%).