PcMtr, an aromatic and neutral aliphatic amino acid permease of Penicillium chrysogenum.

The gene encoding an aromatic and neutral aliphatic amino acid permease of Penicillium chrysogenum was cloned, functionally expressed and characterized in Saccharomyces cerevisiae M4276. The permease, designated PcMtr, is structurally and functionally homologous to Mtr of Neurospora crassa, and unrelated to the Amino Acid Permease (AAP) family which includes most amino acid permeases in fungi. Database searches of completed fungal genome sequences reveal that Mtr type permeases are not widely distributed among fungi, suggesting a specialized function.

Uptake of the beta-lactam precursor alpha-aminoadipic acid in Penicillium chrysogenum is mediated by the acidic and the general amino acid permease.

External addition of the beta-lactam precursor alpha-aminoadipic acid to the filamentous fungus Penicillium chrysogenum leads to an increased intracellular alpha-aminoadipic acid concentration and an increase in penicillin production. The exact route for alpha-aminoadipic acid uptake is not known, although the general amino acid and acidic amino acid permeases have been implicated in this process. Their corresponding genes, PcGAP1 and PcDIP5, of P. chrysogenum were cloned and functionally expressed in a mutant of Saccharomyces cerevisiae (M4276) in which the acidic amino acid and general amino acid permease genes (DIP5 and GAP1, respectively) are disrupted. Transport assays show that both PcGap1 and PcDip5 mediated the uptake of alpha-aminoadipic acid, although PcGap1 showed a higher affinity for alpha-aminoadipic acid than PcDip5 (K(m) values, 230 and 800 microM, respectively). Leucine strongly inhibits alpha-aminoadipic acid transport via PcGap1 but not via PcDip5. This difference was exploited to estimate the relative contribution of each transport system to the alpha-aminoadipic acid flux in beta-lactam-producing P. chrysogenum. The transport measurements demonstrate that both PcGap1 and PcDip5 contribute to the alpha-aminoadipic acid flux.

Determination of clofazimine in leprosy patients by high-performance liquid chromatography.

An original, simple, specific, and rapid high-performance liquid chromatography assay for the determination of clofazimine in human plasma is presented. The procedure consists of extracting the drug and the internal standard (medazepam) from 0.5 mL plasma with dichloromethane/diisopropyl ether (1:1, v/v) at pH 3.0, after precipitating the proteins with methanol. The drugs were then quantitated on a reversed-phase C8 using a mobile phase consisting of a mixture of methanol/0.25 N sodium acetate buffer at pH 3.0 (74:26, v/v). The flow-rate and wavelength were set at 1 mL/min and 286 nm, respectively. The precision, linearity, and limit of quantitation of the method were within acceptable limits. The method was considered adequate and could be applied in studies involving blood level monitoring and pharmacokinetics in leprosy patients.

Determination of clofazimine in leprosy patients by high-performance liquid chromatography

An original, simple, specific, and rapid high-performance liquid chromatography assay for the determination of clofazimine in human plasma is presented. The procedure consists of extracting the drug and the internal standard (medazepam) from 0.5 mL plasma with dichloromethane/diisopropyl ether (1:1, v/v) at pH 3.0, after precipitating the proteins with methanol. The drugs were then quantitated on a reversed-phase C8 using a mobile phase consisting of a mixture of methanol/0.25 N sodium acetate buffer at pH 3.0 (74:26, v/v). The flow-rate and wavelength were set at 1 mL/min and 286 nm, respectively. The precision, linearity, and limit of quantitation of the method were within acceptable limits. The method was considered adequate and could be applied in studies involving blood level monitoring and pharmacokinetics in leprosy patients.

Cloning and characterization of an aromatic amino acid and leucine permease of Penicillium chrysogenum.

The gene encoding the amino acid permease ArlP (Aromatic and leucine Permease) was isolated from the filamentous fungus Penicillium chrysogenum after PCR using degenerated oligonucleotides based on conserved regions of fungal amino acid permeases. The cDNA clone was used for expression of the permease in Saccharomyces cerevisiae M4054, which is defective in the general amino acid permease Gap1. Upon overexpression, an increase in the uptake of L-tyrosine, L-phenylalanine, L-tryptophan and L-leucine was observed. Further competition experiments indicate that ArlP recognizes neutral and aromatic amino acids with an unbranched beta-carbon atom.

Staphylococcus aureus cell extract transcription-translation assay: firefly luciferase reporter system for evaluating protein translation inhibitors.

The promoter for the Staphylococcus aureus capsule polysaccharide synthesis gene (cap1A) was cloned in front of the firefly luciferase gene for use in a cell extract S. aureus transcription-translation system. The assay is rapid, reproducible, and sensitive and has a lower background level than the radiolabeled amino acid incorporation translation assays. We present data evaluating a transcription inhibitor and a number of protein translation inhibitors in this system.

Influence of acetylator phenotype on the haematological and biochemical effects associated with dapsone in leprosy patients.

Methaemoglobinaemia and haemolytic anaemia were the principal side-effects observed in 30 leprosy patients undergoing long-term treatment with dapsone as a single drug or as part of multidrug therapy. Hepatic, pancreatic and renal evaluations showed no relevant clinical changes. Since N-acetylation is a major metabolic pathway for dapsone, slow acetylation phenotype may be a risk factor for the development of these reactions. To confirm this hypothesis we correlated acetylator phenotype and the haematological and biochemical effects induced by dapsone. No excess proportion of slow acetylators was found. We conclude that slow acetylators are not at greater risk of developing haematological side-effects of dapsone than fast acetylators.

Mechanism of action of oxazolidinones: effects of linezolid and eperezolid on translation reactions.

The oxazolidinones are a new class of synthetic antibiotics with good activity against gram-positive pathogenic bacteria. Experiments with a susceptible Escherichia coli strain, UC6782, demonstrated that in vivo protein synthesis was inhibited by both eperezolid (formerly U-100592) and linezolid (formerly U-100766). Both linezolid and eperezolid were potent inhibitors of cell-free transcription-translation in E. coli, exhibiting 50% inhibitory concentrations (IC50s) of 1.8 and 2.5 microM, respectively. The ability to demonstrate inhibition of in vitro translation directed by phage MS2 RNA was greatly dependent upon the amount of RNA added to the assay. For eperezolid, 128 microg of RNA per ml produced an IC50 of 50 microM whereas a concentration of 32 microg/ml yielded an IC50 of 20 microM. Investigating lower RNA template concentrations in linezolid inhibition experiments revealed that 32 and 8 microg of MS2 phage RNA per ml produced IC50s of 24 and 15 microM, respectively. This phenomenon was shared by the translation initiation inhibitor kasugamycin but not by streptomycin. Neither oxazolidinone inhibited the formation of N-formylmethionyl-tRNA, elongation, or termination reactions of bacterial translation. The oxazolidinones appear to inhibit bacterial translation at the initiation phase of protein synthesis.

Deficiency of inflammatory cell adhesion molecules protects against atherosclerosis in mice.

Leukocyte and endothelial cell adhesion molecules (CAMs) are essential for emigration of leukocytes, with the selectins mediating the initial step of leukocyte "rolling" and the beta 2-(CD18) integrins and intercellular adhesion molecule-1 (ICAM-1) being important for firm adhesion and emigration. On the basis of evidence for an inflammatory component in the pathogenesis of atherosclerosis, including increased expression of CAMs, cytokines, and growth factors, we tested the hypothesis that decreased expression of inflammatory CAMs would reduce susceptibility to atherosclerosis. Using C57BL/6 mice fed a high-fat diet, we observed a 50% to 75% reduction in atherosclerotic fatty streaks in mice with homozygous mutations for ICAM-1, P-selectin, CD18, both ICAM-1 and CD18, or both ICAM-1 and P-selectin. In contrast to previous evidence of increased expression of CAMs in atherosclerotic lesions, which does not prove a cause-and-effect relationship, these data indicate directly that the level of expression of CAMs can determine the susceptibility to the formation of atherosclerotic fatty streaks. The results suggest that genetic variation at these loci could influence susceptibility to atherosclerosis and that pharmacological reduction of the expression or function of these CAMs might protect against atherosclerosis.

Postpartum symptoms. Episiotomy or tear at vaginal delivery.

The influence of episiotomy was evaluated in a quasi-randomized follow-up study. In 193 primiparas with spontaneous vaginal delivery, postpartum perineal pain and insufficiency symptoms and their duration were evaluated by means of a questionnaire, 15-24 months post partum. Information about the birth and any complications was obtained from the medical records. On comparing the 85 primiparas delivered by midwives who had a low episiotomy rate (mean 21%) versus the 61 primiparas delivered by midwives with a medium episiotomy rate (mean 34%) and the 41 delivered by midwives with a high episiotomy rate (mean 70%), no differences were found regarding postpartum perineal pain and insufficiency symptoms. Postpartum perineal pain symptoms were significantly correlated to the duration of the second stage of labor, irrespective of the episiotomy rate of the midwife in charge, or of the use of episiotomy.

Mycobacterium terrae tenosynovitis.

A 72-year-old man was admitted with tenosynovitis of the left forearm and hand. Histopathologic examination of the excised tissue showed noncaseating granulomas. Mycobacterial culture produced Mycobacterium terrae complex. M. terrae infection of any site is rare. Analysis of four documented cases and our present case indicates that this organism causes infection in the forearm and hand after probable direct inoculation. It has not disseminated systemically from the site of local infection and may infect otherwise healthy hosts.

[Analysis of inter and intrapathologist concordance and discordance in a comparative study of the Madrid and Ridley-Jopling classifications of leprosy]. / Analyse de la concordance et de la discordance interet intrapathologistes dans une étude comparative des classifications de la lèpre de Madrid et de Ridley-Jopling.

Eighty-six patients of leprosy have been examined by three leprologists; they have been classified according to the Madrid classification and their lesions biopsied and sent to two pathologists for independent histopathological examination. The pathologists have not received any information regarding the cases. Firstly the "senior" pathologist (A) utilized the Madrid classification and the "junior" pathologist (B) the Ridley-Jopling classification. In a second phase, the "senior" pathologist utilized the Ridley-Jopling classification and the "junior" pathologist the Madrid classification. Both pathologists did not know their own previous histopathological diagnosis at the second phase. The analysis of concordance and discordance between the histopathological diagnosis of the two pathologists and for the same pathologist, on utilizing the two classifications, have elicited the following conclusions: 1. There has been more concordance between the two pathologists on utilizing the Madrid classification than the Ridley-Jopling classification for the lepromatous, borderline and tuberculoïd in reaction patients. 2. The comparison of the two classifications for each pathologist on "blindly" examination of the material, has shown more concordance for the "senior" pathologist than for the "junior" pathologist. 3. These observations have convoyed to the final conclusion that the Ridley-Jopling classification brings some difficulties to the pathologists with limited experience in leprology and therefore it should be utilized only by experienced pathologists. 4. This preliminary study shows the necessity of performing another one with larger number of patients, in the active phase, with larger number of pathologists, preferably from different countries, and by utilizing the same methodology of "blind" examination of the material.

Epidemiological survey of skin diseases in schoolchildren living in the Purus Valley (Acre State, Amazonia, Brazil).

A total of 9,955 schoolchildren aged 6-16 years have been examined in a tropical region. The prevalence of dermatosis varied from 21 to 87% in the municipalities surveyed. The most common dermatoses were pediculosis (prevalence 50%), nevi (16.8%), pityriasis versicolor (13.2%), pyoderma (12.2%), pityriasis alba (9.9%), dermatophytosis (6.2%), viral dermatosis (6.2%), scabies (3.0%) and acne vulgaris (2.7%). The prevalence of angular stomatitis, miliaria rubra, candidiasis, piedra nigra, keratosis pilaris, ephelides and geographic tongue is lower but still relatively high. Females had higher rates of pediculosis capitis and males higher prevalence of pityriasis alba. The prevalence of pityriasis versicolor, pigmented nevus and scabies was similar in males and females. Folliculitis, macular pigmented nevi and especially pityriasis versicolor tended to increase with age. Leprosy is hyperendemic in the surveyed area and its rate in the schoolchildren examined was 0.08%. Population movement (urbanization), socioeconomic situation, living conditions, promiscuity, and lack of hygiene may be the cause of such high prevalence and of association of two or more skin conditions. Climatic conditions might have enhanced the prevalence of certain dermatoses (pityriasis versicolor, dermatophytosis, piedra nigra, candidiasis, miliaria rubra).