Recent thymic emigrants in lymphoma patients with and without human immunodeficiency virus infection candidates for autologous peripheral stem cell transplantation.

Signal joint T cell receptor excision circles (sjTRECs) have been reported as a clinical marker to measure the potential for recovery of the immune system after immunosuppressive treatments. The aim of this study was to investigate the thymic regenerative potential in 55 human immunodeficiency virus (HIV)-1 infected (HIV(+)) and non-infected (HIV(-)) lymphoma patients, candidates for autologous stem cell transplantation (ASCT). Moreover, the possible associations between sjTRECs and other immunological and clinical parameters were examined. SjTRECs levels in peripheral blood mononuclear cells (PBMCs) were quantified by real-time polymerase chain reaction and T lymphocyte subsets were analysed by flow cytometry. Our data showed that sjTRECs were reduced in lymphoma patients compared to healthy controls, although a weak significant association between low sjTRECs levels and increasing age was maintained [odds ratio (OR) = 4.00; 95% confidence interval (CI) 1.09-17.17]. We found that different chemotherapeutic treatments seem to induce similar effects on the thymic reservoir, independently from their intensity (type and number of cycles of previous chemotherapy). Results from multivariate models including adjustment for patients' sex, type of lymphoma and type of chemotherapy showed that thymic output was independent from HIV infection (OR, 0.95; 95% CI 0.20-4.48). SjTRECs levels correlated with naive T cell subsets in overall lymphoma patients and after stratification by HIV infection (r > 0.37). HIV replication should be maximally suppressed to properly evaluate thymic output by sjTREC markers. Our results suggested that de novo T cell generation is maintained partially in pretreated recurrent lymphoma patients, candidates for ASCT, and could contribute to restore the immune function after transplantation.

ACE inhibitors in hypertension: assessment of taste and smell function in clinical trials.

Taste and smell disturbances are infrequently reported adverse effects of treatment with captopril and are even less frequently reported with other ACE inhibitors. These adverse effects have been attributed to the chemical structure of the drugs used, although this relationship is the matter of some debate. A link between the taste disturbance associated with ACE inhibitors and changes in plasma zinc concentration has also been suggested, but again the evidence for this relationship is equivocal. One problem facing research in this area has been the lack of reliable assessment techniques for the quantitative evaluation of smell and taste function. Three quantitative methods for evaluating taste and smell function are described, together with the results of a pilot study aimed at evaluating the potential ease of application of these techniques in a larger group of patients. In this double-blind, crossover pilot study, 8-week treatment with lisinopril (20-40 mg once daily) was compared with captopril (25-50 mg twice daily) in 12 hypertensive patients. The two drugs produced similar falls in lying and standing blood pressure and neither drug produced a significant alteration in smell recognition, or olfactory or taste threshold. None of the minor changes observed appeared to correlate with either plasma zinc concentrations or intra-erythrocyte zinc levels. This study provides important observations on the use of these new techniques. Based on the wide variability of results obtained, the design of further clinical studies must address and overcome the many factors (age, sex, smoking, etc.) which may confound the study of drug effects on taste and smell.

Carbohydrate catabolism of Mima polymorpha. I. Supplemental energy from glucose added to a growth medium.

Bell, Emily J. (University of Cincinnati, Cincinnati, Ohio), and Adrienne Marus. Carbohydrate catabolism of Mima polymorpha. I. Supplemental energy from glucose added to a growth medium. J. Bacteriol. 91:2223-2228. 1966.-Mima polymorpha, unable to grow in the presence of nonphosphorylated sugars as sole source of carbon and energy, grows rapidly and well in the presence of acetate, ethyl alcohol, short-chained fatty acids, and permeable intermediates of the tricarboxylic acid cycle. Chemical evidence indicates, however, a limited uptake of glucose. Further, glucose, although incapable of supporting growth as the sole source of carbon and energy, does increase both the rate of growth and the total cell crop when added as an ancillary nutrient to cells growing in a mineral salts medium which contains 0.03 m acetate as the carbon and energy source. A yield of energy from an abortive catabolism of glucose is hypothesized. In addition to the enhancement of growth rate and total cell crop, this hypothesis is supported by the facts that: (i) transport systems for the slightly permeable phosphorylated hexoses appear to be induced when glucose is incorporated into a medium capable of supporting growth and (ii) the rate of induction and the total activity of an inducible enzyme, isocitrate lyase E.C. 4.1.3.1., are markedly increased in the presence of supplemental glucose.

Carbohydrate catabolism of Mima polymorpha. II. Abortive catabolism of glucose.

Marus, Adrienne (University of Cincinnati, Cincinnati, Ohio), and Emily J. Bell. Carbohydrate catabolism of Mima polymorpha. II. Abortive catabolism of glucose. J. Bacteriol. 91:2229-2236. 1966.-Mima polymorpha, unable to grow in the presence of glucose as a sole carbon and energy source, is able to obtain supplemental, utilizable energy from the partial catabolism of this substrate. Various enzymes of hexose catabolism have been assayed in this organism and in M. polymorpha M, a mutant obtained by ultraviolet irradiation. The parent strain contains a functional glucose dehydrogenase, glucose-6-phosphate dehydrogenase, diphosphofructoaldolase, and a 2-keto-3-deoxy-6-phosphogluconate aldolase, but is lacking in glucokinase, gluconokinase, 2-ketogluconokinase, and 6-phosphogluconate dehydrogenase. The enzymes present indicate partially functioning hexose diphosphate and Entner-Doudoroff pathways. The absence of kinases explains the inability of the strain to grow on glucose and an absence of 6-phosphogluconate dehydrogenase would indicate the absence of the complete pentose pathway. The mutant strain, M. polymorpha M, possesses, in addition to those enzymes produced by the wild type, both gluconokinase and 6-phosphogluconate dehydrogenase. The presence of the former explains the mutant's ability to grow on glucose, and the presence of the latter indicates a more complete pentose shunt. The supplemental energy obtained from partial glucose catabolism (to gluconic acid) may be obtained from a cytochrome-linked reaction of the glucose dehydrogenase.