T Cell-Dependent Activation of Macrophages and Enhancement of Their Phagocytic Activity in the Lungs of Mice Inoculated with Heat-Killed Cryptococcus neoformans: Involvement of IFN-γ and Its Protective Effect against Cryptococcal Infection

Previous investigations have demonstrated that macrophages play a critical role in the first-line cellular defense mechanism against infection with Cryptococcus neoformans. In the present study, to elucidate the way in which anticryptococcal activity of macrophages is regulated at the site of infection, pulmonary intraparenchymal macrophages were directly analyzed for expression of their surface molecules and their phagocytic activities against the organism, and the effects of depletion of T cells and endogenous IFN-γ in vivo on these parameters were examined. In the lungs of mice intratracheally inoculated with heat-killed C. neoformans, macrophages were activated, as indicated by augmented expression of MHC class II, intercellular adhesion molecule-1 (ICAM-1) and Fc receptor (FcR), and about two-thirds of macrophages were found to have ingested an average of 3.77 ± 0.12 yeast cells per macrophage. In mice depleted of both CD4⁺ and CD8⁺ T cells by injecting the specific monoclonal antibodies (mAbs) or anti-IFN-γ mAb, not only augmentation of the expression of macrophage activation markers but also phagocytosis of C. neoformans was significantly reduced. These results suggest that anticryptococcal activity of macrophages is regulated by IFN-γ endogenously produced by T cells. Additionally, treatment with IFN-γ were shown to significantly prolong the survival time of mice infected with viable C. neoformans. Additionally, preimmunization with heat-killed C. neoformans significantly prolonged the survival time of mice which received the following infection.     

Distribution of immunoreactive neuropeptides in the pancreas of the bullfrog,Rana catesbeiana,demonstrated by immunofluorescence

Indirect double immunofluorescence labelling for eight neuropeptides in the pancreas of the bullfrog, Rana catesbeiana, demonstrated the occurrence, distribution, and coexistence of certain neuropeptides in the exocrine and endocrine pancreas. Immunoreactivity of substance P (SP), calcitonin gene-related peptide (CGRP), vasoactive intestinal polypeptide (VIP), neuropeptide Y (NPY), FMRFamide (FMRF), and galanin (GAL) was localized in nerve fibers distributed between the acini and around the duct system and vasculature of the exocrine pancreas. In these regions, CGRP-immunoreactive fibers were more numerous than those containing the other five peptides. Almost all SP fibers showed coexistence of SP with CGRP, and about one third of fibers also showed coexistence of SP with VIP, NPY, FMRF, and GAL. In the endocrine pancreas, SP, CGRP, VIP, and GAL were recognized in the nerve fibers around and within the islets of Langerhans, and VIP and GAL fibers were more numerous than SP and CGRP fibers. All CGRP fibers, and about half of the VIP and GAL fibers were immunoreactive for SP. NPY- and FMRF-immunoreactive cells were found at the periphery of the islets. These findings suggest that the exocrine and endocrine pancreatic functions of the bullfrog are under the control of peptidergic innervation.     

Intron length variation of the Adh gene in Brachyscome (Asteraceae)

Eighteen polymerase chain reaction (PCR) products of the partial sequence of the Adh (alcohol dehydrogenase) gene from 10 Brachyscome species were sequenced and compared. These products contained the 5 three fourths of exon 4 and whole sequences of intron 3. They varied extensively in length due to the differences in length of intron 3. A total of 10 long insertions were flanked by direct repeats of 5 to 12 bp sequences, indicating inserted elements. These inserted elements were classified into the following five categories based on nucleotide sequence characteristics and length; (1) a region homologous to that of 5S RNA genes (5S DNA), (2) A-rich structure at the 3 end-like short interspersed elements (SINEs) in animals, (3) a sequence of 280 bp with no characteristic features, (4) a sequence of 125 bp with no characteristic features, (5) termini of 11 bp inverted repeats flanked by 5 bp sequence of direct repeats characteristics of a transposon.     

Hydrolytic dehalogenation of 4-chlorobenzoic acid by an Acinetobacter sp

Acinetobacter sp. strain ST-1, isolated from garden soil, can mineralize 4-chlorobenzoic acid (4-CBA). The bacterium degrades 4-CBA, starting with dehalogenation to yield 4-hydroxybenzoic acid (4-HBA) under both aerobic and anaerobic conditions, suggesting that the dehalogenating enzyme in the strain is not an oxygenase; the enzyme may catalyze halide hydrolysis. To identify the oxygen source of the C(4)-hydroxy groups in the dehalogenation step, we used H(2)(18)O as the solvent under anaerobic conditions. When resting cells were incubated in the presence of 4-CBA and H(2)(18)O under a nitrogen gas stream, the hydroxy group on the aromatic nucleus of the 4-HBA produced was derived from water, not from molecular oxygen. This dehalogenation was hydrolytic, because analysis of the mass spectrum of the trimethylsilyl derivative of one of the metabolites, (18)O-labeled 4-HBA, showed that 80% of the C4-hydroxy groups were labeled with (18)O. Hydrolytic dehalogenation of 4-CBA in intact cells has not been reported earlier. To identify substrate specificity, we next examined the ability of the strain to dehalogenate 4-CBA analogues and dichlorobenzoic acids. The results of metabolite analysis by high-pressure liquid chromatography showed that the strain dehalogenated 4-bromobenzoic acid and 4-iodobenzoic acid, yielding 4-HBA, suggesting that these compounds could be further degraded and mineralized by the strain via the beta-ketoadipate pathway, as occurs with 4-CBA. This strain, however, did not dehalogenate 4-fluorobenzoic acid, 2- and 3-chlorobenzoic acids, or 2,4-, 3,4-, and 3,5-dichlorobenzoic acids during 4 days of incubation, implying that the dehalogenating enzyme of the strain has high substrate specificity.     

Structural analysis and chromosomal localization of the mouse Psmb5 gene coding for the constitutively expressed β-type proteasome subunit

 The proteasome is a multi-subunit protease responsible for the production of peptides presented by major histocompatibility complex class I molecules. Accumulated evidence indicates that, upon stimulation with interferon-γ (IFN-γ), three β-type subunits, designated LMP2, LMP7, and PSMB10, are incorporated into the 20S proteasome by displacing the housekeeping β-type subunits designated PSMB6, PSMB5, and PSMB7, respectively. These changes in the subunit composition appear to facilitate class I-mediated antigen presentation, presumably by altering the cleavage specificities of the proteasome. In the present study, we determined the organization of the mouse gene Psmb5, coding for the PSMB5 subunit. Psmb5 is made up of three exons, spanning ∼5 kilobases. Its exon-intron organization differs radically from those of the other IFN-γ-regulated, β-type subunit genes including Lmp7 with which Psmb5 is believed to share an immediate common ancestor. The structure of the mouse Psmb5 gene is identical to that of its recently characterized human counterpart. Thus, the unique organization of the gene coding for the PSMB5 subunit appears to have been established before mammalian radiation. As well as the Psmb5 gene, the mouse genome contains a processed pseudogene designated Psmb5-ps. Interspecific backcross mapping showed that Psmb5 maps close to the Gtrgal2 locus on chromosome 14 and that Psmb5-ps is located in the vicinity of the Psme3 locus on chromosome 11. These results were confirmed by fluorescent in situ hybridization analysis that localized Psmb5 to band C2 to proximal D1 of chromosome 14 and Psmb5-ps to band D of chromosome 11. Received: 29 May 1997 / Revised: 4 June 1997     

Effects of 20 days bed rest on muscle morphology

Using ultrasound, muscle thickness and fascicle angles from aponeurosis were evaluated before, during and after 20 days bed rest (BR). Subjects were healthy adults (4 women and 4 men). Measurements were carried out before and after BR and after 10 weeks of recovery, respectively. Muscle measurements were taken at nine sites in trunk and upper and lower extremities, respectively. For the m. triceps brachii, m. vastus lateralis, and m. gastrocnemius medialis, fascicle angles from the aponeurosis as well as muscle thickness were measured. There was a high statistical significant correlation between muscle thickness and cross-sectional area for quadriceps muscles, suggesting applicability of muscle thickness for evaluation of muscle size. Muscle thickness decreased in muscles of the lower extremity by 2.1-4.4 % after bed rest. In triceps brachii and vastus lateralis muscles, there were no prominent changes in muscle thickness and fascicle angles. It was concluded that muscle morphology deteriorates with changes in muscle architecture by bed rest but the response is small and muscle-specific. It was also suggested that bed rest affects not only muscle mass but muscle tone as well.     

A 570-kb DNA Sequence of the Escherichia coli K-12 Genome Corresponding to the 28.0-40.1 min Region on the Linkage Map

The 569,750 base pair sequence corresponding to the 28.0–40.1min region on the genetic map of Escherichia coli K-12 (W3110)was determined. This region includes the replication terminusregion and contained at least 549 potential open reading frames.Among them, 160 (29%) were previously reported, 174 (32%) werehomologous to other known genes, 102 (18%) were identical orsimilar to hypothetical genes registered in databases, and theremaining 113 (21%) did not show a significant similarity toany other gene. Of interest was the finding of a large numberof genes and gene clusters in andnear the replication terminationregion which had been thought to be genetically silent. Thoseincludeda cluster of genes for fatty acid ß-oxidation,the third copy of the pot (spermidine/putrescine transport system)gene cluster, the second dpp (dipeptide transport system) operon,the second dsm (anaerobic dimethyl sulfoxide reductase) operon,a cluster of fim (fimbrial) genes anda DNA helicase-like genewith a high molecular weight. In addition, we found the dnaC-and dnaT-like genes in the cryptic prophage, Rac, anda numberof genes originated probably from plasmids.     

Acute effect of beraprost sodium on lower limb circulation in patients with non-insulin-dependent diabetes mellitus-evaluation by color doppler ultrasonography and laser cutaneous blood flowmetry

The acute effects of beraprost sodium (sodium (±)-(1R^*, 2R, 3aS^*, 8bS^*)-2, 3, 3a 8b-tetrahydro-2-hydroxy-l-((E)-(3S^*)-3-hydroxy-4-methylI-octen-6-yny1] -1H-cyclopenta [b] bensofuran-5-butyrate), a stable analogue of prostaglandin I₂ which works as a vasodilator and anti-platelet agent, were investigated in patients with non-insulin dependent diabetes mellitus. Its effects on the dorsal pedis artery were examined using a new real-time two-dimensional Doppler ultrasonographic technique and by laser blood flowmetry. Before and 60 min after oral administration of beraprost sodium (Dolner^® 40 μg) and elastase (Elaszym^® 1800 U), the cross-sectional area (CSA) of the dorsal pedis artery and its blood flow index (BFI), calculated from the maximum flow velocity and area, were determined. Dermal microcirculatory blood volume (MBV) was also measured by laser blood flowmetry. In the beraprost sodium group, the CSA, BFI and MBV were significantly increased, while in the elastase group, no significant changes were observed. These result suggest that beraprost sodium has a beneficial effect on diabetic macro- and microangiopathy.     

Sharing positive experiences in making changes in work and life in a local district in Vietnam

A series of research and training programmes were undertaken in a rural district in the Mekong Delta area in Vietnam so as to facilitate positive changes in the work and life under the initiatives of the local people. As in other parts of the area, it was amid rapid changes in life-style under the shift toward a market economy. Field research relying on direct observation methods were carried out in various rice field jobs and local small enterprises for understanding the improvement potentials in the work and lives of the local people. To strengthen the local improvement initiatives, participatory training programmes were developed and practiced. In the training programmes, joint walk-through observations using an action checklist were stressed. The results were discussed in small groups and meetings. Interactive communications between the local people, while visiting their own houses and workplaces, took place. Based on these field research results, various positive changes were successfully implemented. They included a wide range of improvements such as more efficient work methods, safer use of technologies, hygienic housing conditions, and improved household plans. Our experiences demonstrated that practical approaches relying on local initiatives could facilitate the implementation of positive changes in the local socio-cultural settings.