Peripheral lymphoid development and function in TCR mutant mice

We describe the development and function of the peripheral lymphoid system of mutant mice rendered deficient in either alpha beta or gamma delta T cells via targeting of TCR genes in embryonic stem cells. In the spleen of alpha beta T cell-deficient mice, gamma delta T cells do not compensate in numbers for the lack of alpha beta T cells, but B cells do. alpha beta T cell-deficient mice are unable to mount an antibody response to ovalbumin and do not reject skin allografts. Natural killer cell function is not impaired in any of the mutant mice. TCR mutant mice will prove useful in dissecting differential functions of alpha beta and gamma delta T cells in vivo.     

Incidence of Prevotella intermedia and Prevotella nigrescens in periodontal health and disease

The incidence of black-pigmented rods (BPRs), especially Prevotella intermedia and Prevotella nigrescens, in periodontal health and disease were examined. Furthermore, the degradative enzyme activities of P. intermedia were compared among the strains from periodontal health and disease. Microbiological specimens were collected from subgingival crevice or periodontal pocket by paper point. The BPRs were found in 71.1% of periodontally healthy subjects (n=45), and in 47.1% of healthy sites (n=34) and 87.8% of active sites (n=41) among periodontally diseased patients. Porphyromonas gingivalis was detected only in active sites of periodontally diseased patients (17.8% of 180 strains). P. intermedia was the predominant BPR in both healthy and active sites (37.3 and 41.7%, respectively) of the patients. However, P. nigrescens was the predominant BPR (70.5% of 173 strains) in periodontally healthy subjects. The enzyme activities of esterase, esterase-lipase, acid-phosphatase and alpha-fucosidase of P. intermedia strains isolated from active sites in patients were significantly higher (P<0.05) than those of healthy subjects. The results suggest that P. intermedia might increase the activity of degradative enzymes under a certain condition and support the progression of periodontitis.     

Production of reactive oxygen species and release of L-glutamate during superoxide anion-induced cell death of cerebellar granule neurons

This study focuses on the different efficiencies of secretion of two fungal cutinases by Saccharomyces cerevisiae, a wild-type cutinase (CY000) and a hydrophobic mutant cutinase (CY028). Both cutinases are placed under control of the GAL7 promoter, by which the expression levels can be regulated. Wild-type cutinase was secreted at up to 25 mg per g (dry weight), while CY028 was secreted at a level of 2 mg per g (dry weight); this difference is nearly independent of the expression level. Pulse-chase experiments revealed that whereas CY000 cutinase is secreted, CY028 is irreversibly retained in the cell. Immunogold labelling followed by electron microscopy revealed colocalization of CY028 with immunoglobulin heavy-chain binding protein (BiP) in the endoplasmic reticulum (ER). The increase of wild-type cutinase expression did not result in higher levels of the molecular chaperone BiP, but BiP levels are raised by increased induction of the hydrophobic mutant cutinase. Immunoprecipitation studies showed that in contrast to the wild-type cutinase, the hydrophobic mutant cutinase interacts with BiP. These results indicate that the introduction of two exposed hydrophobic patches in cutinase results in a higher affinity for BiP which might cause the retention of this mutant cutinase in the ER.     

Quantitation of amyloid beta-protein (A beta) in the cortex during aging and in Alzheimer's disease

In this study we sought to learn about when and how amyloid beta-protein (A beta) accumulates in the cortex of normal individuals and about the difference in the A beta accumulation between normal aged and Alzheimer's disease (AD) brains. From consecutive autopsy cases and AD cases, hippocampus CA1 and occipitotemporal cortex T4 were sampled for A beta quantitation by the well characterized two-site enzyme immunoassays (EIAs). There was a strong tendency toward A beta 42 accumulation between the ages of 50 and 70 years in T4 and a little later in CA1. The A beta 42 levels were consistently higher in T4 than those in CA1 in any given case. The levels of A beta 42 in AD brains were significantly higher than those in control brains, and the extent of A beta 42 amino-terminal modification was also much greater in AD brains than that in control brains. Even in cases in which no senile plaques were immunocytochemically detected, EIAs clearly showed that significant amounts of A beta 42 already had accumulated. In contrast to A beta 42, A beta 40 showed no apparent age-dependent accumulation, and its high levels were found to be associated with AD.     

Analysis of Vero toxins 1 and 2 by high-performance liquid chromatography/electrospray ionization mass spectrometry

PURPOSE: To study the interaction between gabapentin (GBP) and high-protein meals, 12 patients with epilepsy were administered this drug both while in a fasting state and after a high-protein meal. METHODS: After having acquired their informed consent, the patients (suffering from partial complex seizures resistant to other anticonvulsants) were randomly assigned to 2 groups of 6 subjects. Each subject was treated in a fasting state with a single 400 (group A) or 800 (group B) mg GBP oral dose. After 24 h, the GBP dose regimen was repeated, but was given after a high-protein meal. Serum GBP concentrations were measured by LC-Mass at baseline and 0.5, 1, 2, 3, 5, 7, 9, 12, and 24 h. Saliva GBP concentrations were determined at baseline and 2, 4.8, and 12 h. GBP urinary excretion was determined at 0-4, 4-8, and 8-12 h intervals. The following kinetic parameters were calculated: area under the concentration time curve from zero time to 24 h after the dose, AUC 0-24 h; maximal serum concentration, Cmax; time to the maximal serum concentration, Tmax; absorption rate constant, ka; elimination rate constant, beta; elimination half-time, t1/2beta. Student's t test for paired data, with significance assigned at P < 0.05, was used. RESULTS: No statistically significant differences were seen in GBP serum or saliva concentrations or in its urinary excretion (both in A or B group) between fasting and after the high-protein meal. CONCLUSIONS: High-protein meals do not seem to interfere with oral disposition of GBP.     

Two cases of male infertility with pathological dilatation of ejaculatory duct

Culturing of rabbit pre-implantation embryos was performed in Ham's F10 medium supplemented with polyvinylpyrrolidone. Under these culture conditions, day 6 post coitum blastocysts increased their diameter within 24 h to 80% of that of day 7 blastocysts grown in vivo. Despite this substained growth, the embryonic disc remained undifferentiated with clear signs of degeneration after 24 h of culture. Basic fibroblast growth factor (bFGF) was able to overcome this developmental block. After 12 h of culture, day 6 blastocysts showed pear-shaped embryonic discs, and after 24 h, the primitive streak with Hensen's node was visible. The bFGF had no comparable effects on day 5 and day 7 blastocysts. The embryonic discs of day 5 blastocysts degenerated, even in the presence of bFGF, whereas day 7 blastocysts were able to form their primitive streak, also in the absence of bFGF. TGF beta 1 did not promote embryonic development in vitro. The data indicate that the onset of mesoderm formation in the rabbit is controlled by a growth factor of the FGF-family.     

Endotracheal cuff pressure as an index of airway smooth muscle activity: comparison with total lung resistance

Human growth is non-linear and short term changes in height velocity cannot be used to predict future growth. This paper discusses the current knowledge of growth dynamics in the context of a historical review of the subject.     

Preliminary screening for antiviral AIDS drugs. VIII. Report for fiscal year 1995

Preliminary screening of antiviral AIDS drugs has been carried out using three different in vitro assay systems. Among 96 samples of different origin tested, two were shown to inhibit the growth of HIV in vitro. One of the positive samples (plant origin) has hopeful signs, as the ranges of effective doses are wider than those of most of positive samples which had been found by us.     

Differences in immune responses to antibiotics in three guinea-pig strains

Dithiocarboxylate ligands were synthesized and characterised. New nitrido 99m-technetium complexes were obtained with these ligands and identified by thin layer chromatography. The nitrido complexes were tested in vitro in whole blood for leucocyte labelling and the design of the ligand was optimized. Best results were obtained with aliphatic linear ligands, containing 9 to 11 atoms of carbon. The in vivo experiment failed because an inflammated area could not be visualized by gamma imaging, the cell labelling mechanism being probably different.     

Acid sphingomyelinase is not essential for the IL-1 and tumor necrosis factor receptor signaling pathway leading to NFkB activation

A recent report has suggested that tumor necrosis factor (TNF) utilizes acid sphingomyelinase (SMase) pathway to activate NFkB (Schutze et al. 1992. Cell 71:765). To directly investigate the role of acid SMase in IL-1 and TNF receptor-mediated signal transduction, we examined the ability of Niemann-Pick disease (NPD) type A fibroblasts, which are deficient in acid SMase, to induce IL-8 gene expression through activating NFkB. Unexpectedly, IL-1 alpha and TNF-alpha efficiently induced IL-8 production and IL-8 mRNA in NPD type A fibroblasts as in normal fibroblasts. Furthermore, activation of NFkB was also induced in NPD type A fibroblasts in response to IL-1 alpha and TNF-alpha stimulation to a similar extent as in normal fibroblasts. These results provide evidence that acid SMase is not essential in IL-1 and TNF receptor signaling leading to NFkB activation as well as the cytokine gene activation which is regulated by NFkB.