Rapid Increase of Pneumococcal Resistance to β-Lactam and Other Antibiotics in Isolates from the Respiratory Tract (Nagasaki,Japan: 1975–1994)

The susceptibility of 101 pneumococcal isolates from the respiratory tract during 1991–1994 was examined and compared with the susceptibility of isolates over the period of 1975–1990. A rapid increase of resistance was seen not only to penicillin but also other antimicrobial agents. During 1991–1994, 38% of all the isolates were resistant to penicillin. The rates of resistance during this period were 16–23% for three newer cephalosporins, 18% for imipenem, 69% for tetracycline, 31% for erythromycin, 20% for chloramphenicol and 9% for clindamycin. The use of antibiotics within one month prior to pneumococcal isolation was correlated with penicillin resistance (P < 0.05). Serotyping of the isolates by antiserum revealed differences in predominant types between penicillin-resistant (19F, 23F, 4) and -susceptible isolates (15, 4, 11A). Our data suggests that anti-pneumococcal antibiotics should be carefully chosen on the basis of susceptibility tests.     

Role of Some Hormones in Protein Sparing Action of Dietary Fat

Feeding rats with a fat meal caused marked reduction in the level of plasma urea and urinary output of urea and total nitrogen. Experiments were carried out to examine the possible intervention of some hormones in these phenomena. Protein sparing action of fat was exerted even in the alloxan-diabetic, adrenalectomized, hypophysectomized and thyroidectomized rats. Feeding rats with a fat meal caused no appreciable change in the level of cyclic AMP in liver and gastrocnemius muscle. The overall results obtained here are through! to suggest that the action of fat may be exerted independently of any hormones examined; insulin, glucocorticoids, cyclic AMP and other hormones excreted from adrenal, hypophysis and thyroid gland.     

Dexamethasone Inhibits Mitogen-dependent Synthesis of Histamine Due to Histidine Decarboxylase Induced in Cultured Mouse Spleen Cells

Schizosaccharomyces pombe has four α-amylase homologs (Aah1p-Aah4p) with a glycosylphosphatidylinositol (GPI) modification site at the C-terminal end. Disruption mutants of aah genes were tested for mislocalization of vacuolar carboxypeptidase Y (CPY), and aah3Δ was found to secrete CPY. The conversion rate from pro- to mature CPY was greatly impaired in aah3Δ, and fluorescence microscopy inidicated that a sorting receptor for CPY, Vps10p, mislocalized to the vacuolar membrane. These results indicate that aah3Δ had a defect in the retrograde transport of Vps10p, and that Aah3p is the first S. pombe specific protein required for vacuolar protein sorting.     

Possible relationship of PFGE patterns of Moraxella catarrhalis between hospital- and community-acquired respiratory infections in a community hospital

We describe a prospective study of molecular analysis of Moraxella catarrhalis isolated from a community hospital. Our study was designed to investigate the possible relationship of pulsed-field gel electrophoresis (PFGE) patterns of M. catarrhalis between hospital- and community-acquired respiratory infections. A nosocomial outbreak of M. catarrhalis was observed between September 2000 and September 2001. During the study period, 40 strains of M. catarrhalis were isolated from a total of 32 patients with respiratory infections (26 strains from 18 inpatients, and 14 strains from 14 outpatients). We compared the PFGE patterns in 40 strains of M. catarrhalis isolated from the respiratory tract of the study patients. The genomic types of M. catarrhalis were classified into three PFGE patterns (A, B, and C). Interestingly, the nosocomial outbreak of M. catarrhalis included two patterns (A and B). Of the three patterns, two patterns (A and B) were found in both inpatients and outpatients. More interestingly, two subtypes of pattern B (B1 and B4) were simultaneously found in both inpatients and outpatients. Our results indicated that PFGE with SmaI chromosomal digestion is a suitable technique to establish the inter-strain genetic relatedness of M. catarrhalis, and suggested that the outbreak of M. catarrhalis occasionally included miscellaneous PFGE patterns. The results also showed that PFGE patterns of M. catarrhalis isolates were similar between hospital- and community-acquired respiratory infections. Analysis of the subtypes suggested that there might be some association between hospital- and community-acquired respiratory infections caused by M. catarrhalis.     

TNT biodegradation and production of dihydroxylamino-nitrotoluene by aerobic TNT degrader <Emphasis Type="Italic">Pseudomonas</Emphasis> sp. strain TM15 in an anoxic environment

Anaerobic bacteria have been used to produce 2,4-dihydroxylamino-nitrotoluene (2,4DHANT), a reductive metabolite of 2,4,6-trinitrotoluene (TNT). Here, an aerobic TNT biodegrader Pseudomonas sp. strain TM15 produced 2,4DHANT as evidenced by the molecular ion with m/z of 199 identified from LC-TOFMS analyses. TNT biodegradation with a high cell concentration (10⁹ cells/ml) led to a significant accumulation of 2,4DHANT in the culture medium, as well as hydroxylamino-dinitrotoluenes (HADNTs), although these products were not accumulated when a low cell concentration was used; also, the accumulation of diamino-nitrotoluene and of an unidentified metabolite were observed in the culture medium with the high cell concentration (10¹⁰ cells/ml). 2,4DHANT overproduction was a function of the aeration speed since cultures with low aeration speeds (30 rpm) had a 19-fold higher DHANT productivity than those aerated with high speeds (180 rpm); this indicates that molecular oxygen was related to the formation of 2,4DHANT. The quantification of dissolved oxygen (DO) in the media demonstrated that the productivity of 2,4DHANT was increased at low DO values. Moreover, supplying oxygen to the culture media produced a remarkable decrease of 2,4DHANT accumulation; these results clearly indicate that high 2,4DHANT production was a consequence of the oxygen deficit in the culture medium. This finding is useful for understanding the TNT biodegradation (bioremediation technology) in an anoxic environment. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

A Rapid Method,Combining Microwave-Assisted Extraction and Gas Chromatography-Mass Spectrometry with a Database,for Determining Organochlorine Pesticides and Polycyclic Aromatic Hydrocarbons in Soils and Sediments

A rapid method for determining organochlorine pesticides and polycyclic aromatic hydrocarbons in soils and sediments was developed to allow pollution surveys to be performed in emergencies. The method involves microwave-assisted extraction and uses an automated identification/quantification system with a gas chromatography mass spectrometry database. A sample (3 g) is extracted with a 3:2 v/v hexane:water mixture (10 mL) for 30 min using a microwave-assisted extraction system at 120°C. The hexane extract is then cleaned using silica gel, then analyzed by gas chromatography mass spectrometry. The total analysis time is approximately 4 h. The precision of the quantitative results and accuracy of the analyte identification were determined. The total analyte concentrations were generally comparable to (61%–110% of) the concentrations determined using a Soxhlet extraction method, but the concentrations of individual high-molecular-weight polycyclic aromatic hydrocarbons were unacceptably low compared with the concentrations determined using the Soxhlet method. However, these compounds (e.g., benzo(ghi)perylene and indeno(1,2,3-cd)pyrene) were subsequently efficiently extracted using a hexane:water:ethanol mixture. The accuracy of identification was evaluated using accurate masses determined by gas chromatography time-of-flight mass spectrometry, and the mass error was 2 ppm for 21 of the 22 compounds identified using the new method.     

Effect of estrogenic activity, and phytoestrogen and organochlorine pesticide contents in an experimental fish diet on reproduction and hepatic vitellogenin production in medaka (Oryzias latipes)

Endocrine-disrupting chemicals (EDCs) are giving rise to serious concerns for humans and wildlife. Phytoestrogens, such as daidzein and genistein in plants, and organochlorine pesticides are suspected EDCs, because their chemical structure is similar to that of natural or synthetic estrogens and they have estrogenic activity in vitro and in vivo. We assessed estrogenic activity and dietary phytoestrogen and organochlorine pesticide contents of various fish diets made in the United Kingdom, and compared them with those features of diets made in Japan that were tested in a previous study. Genistein and daidzein were detected in all of the diets. Using an in vitro bioassay, many of these diets had higher activation of estrogen beta-receptors than estrogen alpha-receptors. Organochlorine pesticides such as hexachlorobenzene, beta-benzene hexachloride (BHC), and gamma-BHC were detected in all fish diets. On the basis of these data, we investigated the effect of differing dietary phytoestrogen content in Japanese fish diets on hepatic vitellogenin production and reproduction (fecundity and fertility) in medaka (Oryzias latipes). Assessment of the effects of a 28-day feeding period on reproduction of paired medaka did not indicate significant differences in the number of eggs produced and fertility among all feeding groups. However, hepatic vitellogenin values were significantly higher for male medaka fed diet C (genistein, 58.5 +/- 0.6 microg/g; daidzein, 37.3 +/- 0.2 microg/g) for 28 days compared with those fed diet A (genistein, < 0.8 microg/g; daidzein, < 0.8 microg/g) or diet B (genistein, 1.4 +/- 0.1 microg/g; daidzein, 2.0 +/- 0.1 microg/g). Our findings indicate that fish diets containing high amounts of phytoestrogens, such as diet C, have the potential to induce hepatic vitellogenin production in male medaka, even if reproductive parameters are unaffected. Therefore, some diets, by affecting vitellogenin production in males, may alter estrogenic activity of in vivo tests designed to determine activity of test compounds added to the diet.     

Crucial problem in rapid spectrophotometric determination of 2,4,6-trinitrotoluene and its breakthrough method

A rapid spectrophotometric determination for 2,4,6-trinitrotoluene (TNT) is significant because this method is suitable for simultaneous analyses of the numerous samples. We found one problem that TNT reduction products interfere with the TNT detection in this assay, and we overcame this problem by heating the samples at 95 degrees C, resulting in the production of compounds that did not interfere.     

Role and Metabolism of Free Leucine in Skeletal Muscle in Protein Sparing Action of Dietary Carbohydrate and Fat

Feeding rats with either a carbohydrate meal or a fat meal to the previously fasted rats caused significant decrease in urinary output of urea and total nitrogen. The content of free leucine in skeletal muscle decreased in the rats fed either a carbohydrate meal or a fat meal. Feeding of either a carbohydrate meal or a fat meal stimulated incoiporation of l-leucine-1–¹⁴C into protein fraction of skeletal muscle and reduced its oxidation to ¹⁴CO₂.

These results suggest that the metabolism of leucine is under nutritional regulation and that the decrease in content of free leucine in skeletal muscle might be caused by enhanced reutilization of leucine into protein by the feeding of a carbohydrate meal or a fat meal. The role of free leucine in skeletal muscle as a regulator of protein turnover in the tissue are discussed in relation to the metabolism of this branched chain amino acid.     

Decreased expression of alpha2,8 sialyltransferase and increased expression of beta1,4 N-acetylgalactosaminyltransferase in gastrointestinal cancers

Gangliosides such as GD3, GM2, and GD2 are abundantly expressed on the cell surfaces of various malignant cells, suggesting the potential for anti-ganglioside antibody therapy for tumors. Anti-ganglioside GD2 antibody treatment is currently undergoing clinical trials for melanoma and neuroblastoma. We previously reported high in vivo antitumor effects of anti-GM2 ganglioside antibody against lung cancer. To determine whether anti-GM2 antibody may be clinically indicated for gastrointestinal cancers, we evaluated the mRNA expression of alpha2,8 sialyltransferase, a GD3 synthase, and beta1,4 N-acetylgalactosaminyltransferase (beta1,4 GalNAc-T), a GM2/GD2 synthase, in gastrointestinal cancers. We performed modified semi-quantitative RT-PCR, which reduces complexity incidental to radiolabeling on samples taken from small surgically removed clinical specimens. Stomach (19/22) and colorectal (21/30) cancers showed decreased expression of alpha2,8 sialyltransferase as compared with respective normal tissues (P < 0.05). In contrast, increased expression of beta1,4 GalNAc-T was detected in both types of tumors. Clinicopathological analysis revealed significantly higher expression level of alpha2,8 sialyltransferase in the poorly differentiated than in the well-differentiated stomach cancer group (P < 0.05). Furthermore, the expression level of alpha2,8 sialyltransferase was significantly decreased in male as compared with female colorectal cancer patients (P < 0.05). These results suggest that expression level of GM2 ganglioside is elevated in gastrointestinal cancer, and that anti-GM2 antibody may be applicable to its treatment.