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S Kawazu

Publications and source records attributed to S Kawazu.

At least 55 records · Page 3Linked to original sources
PubMed1995

Selection of diversity at putative glycosylation sites in the immunodominant merozoite/piroplasm surface antigen of Theileria parasites.

The immunodominant merozoite/piroplasm surface antigen of Theileria parasites has potential as a diagnostic reagent and as a component of a sub-unit vaccine. This molecule is known to be antigenically diverse, and it is important to determine the nature and extent of this heterogeneity. In the present study nucleotide sequences, representing alleles of the gene (Tams1) encoding this molecule in Theileria annulata were compared to each other and to sequences of homologous genes in Theileria sergenti, Theileria buffeli and Theileria parva. This analysis revealed that a region of the polypeptide which contains putative N-linked glycosylation sites is particularly diverse and, in analogy to retroviral systems, may indicate selection of variable glycosylation sites or amino acid epitopes to evade the bovine immune response. This conclusion was also made from the results of a phylogenetic analysis which compared the variable region of the genes with a second region, which appeared to show no bias for diversity or functional constraint. The results indicated that the variable sequence encoding putative glycosylation sites has diverged, both within and between Theileria species, at a much faster rate than the rest of the molecule. Southern blot analysis of T. annulata populations from within a single geographical region detected six possible variant Tams1 alleles. However, a correlation between restriction-fragment-length polymorphism (RFLP) patterns detected by the Tams1-1 gene probe and geographical location could not be made. In addition, although a high prevalence of one particular RFLP was found, this is unlikely to be the result of a clonal population structure, as we present evidence for significant parasite genotypic variability within a single endemic region.

Amino Acid Sequence↗
PubMed1995

Increased expression of a regenerating (reg) gene protein in neonatal rat pancreas treated with streptozotocin.

We examined the expression of reg protein in neonatal rat pancreas treated with streptozotocin (STZ) by means of the immunohistochemical technique and northern blotting. Seven days after STZ injection, the plasma glucose levels in STZ-treated neonatal rats were significantly higher than those in control rats. Scattered distribution of reg protein in pancreatic islet cells was clearly observed in STZ-treated rats, but not in control rats. On the other hand, reg proteins was positively stained in the exocrine cells in both groups of rats. Northern blot analyses revealed that the expression of insulin mRNA markedly decreased in STZ-treated rat pancreas, but a significant increase in reg mRNA expression was recognized in the STZ-treated rat pancreas compared with that of control rats. Rats treated with STZ during the neonatal period have been used as a model of non-insulin-dependent diabetes mellitus (NIDDM) and beta cell regeneration. Thus, the increased reg gene expression in neonatal STZ-treated rat pancreas was therefore described for the first time, and thus would be a useful model for studying the relationship between NIDDM and beta cell regeneration or reg gene protein.

Animals↗
PubMed1995

Effects of posture on creatinine clearance and urinary protein excretion in patients with various renal diseases.

To investigate the effects of a change in posture on renal function, we measured Ccr and the urinary excretion of protein, albumin, immunoglobulin G (IgG) and transferrin in 80 patients with renal disease and in 9 healthy controls. Patients and controls were studied serially while supine for 60 min; then after standing upright for 60 min. Almost all subjects showed a drop in the Ccr with standing (p < 0.01). The percent change in Ccr after standing was more remarkable in patients with glomerulonephritis vs the healthy subjects (74.0 +/- 21.9% vs 89.9 +/- 12.3%, p < 0.01). The change in urinary excretion of protein and albumin after standing in patients with membranous nephropathy (MN-N) significantly exceeded that in patients with IgA nephropathy (IgA-N) (182.1 +/- 89.3% vs 108.1 +/- 59.2% in urinary protein and 181.7 +/- 98.7% vs 113.3 +/- 40.9% in urinary albumin, p < 0.01). Urinary excretion of IgG and transferrin tended to increase after standing in those two groups, but not significantly. Results indicate that posture affects urinary protein excretion, probably via an increase of glomerulocapillary hydrostatic pressure and/or change in the permeability of the glomerular capillary walls. We recommend that comparable postures should be used when protein excretion is used as a diagnostic tool and in monitoring structural damage to glomeruli, particularly in patients with membranous nephropathy.

Adult↗
PubMed1994

Improvement of glucose tolerance by bezafibrate in non-obese patients with hyperlipidemia and impaired glucose tolerance.

Glucose intolerance or diabetes mellitus, hyperlipidemia, obesity and hypertension may have a close interrelation based on insulin resistance. We selected 28 impaired glucose tolerance (IGT) patients with hyperlipidemia. The IGT patients demonstrated hypertriglyceridemia associated with hyperinsulinemia, a typical manifestation of insulin resistance. Administration of bezafibrate at 400 mg/day for 4 weeks to the IGT patients with hypertriglyceridemia resulted in an improvement of the plasma glucose level and insulin response to 75 g oral glucose loading associated with a concomitant decrease in non-esterified fatty acids. The ratio of the level of serum C-peptide to that of insulin after a 75 g oral glucose tolerance test (OGTT) was augmented after 4 weeks of bezafibrate administration. However, reduction of the cholesterol level with pravastatin did not alter these parameters. These results suggest that treatment to reduce the level of serum triglycerides, but not that of cholesterol, may have a beneficial effect for improving insulin resistance even in the non-obese subjects with IGT and decreasing the risk of coronary heart disease.

Bezafibrate↗
PubMed1994

The role of insulin in coronary atherosclerosis.

In 197 patients with coronary artery disease (CAD) who underwent coronary angiography, 75 g oral glucose tolerance test (OGTT) was performed, measuring plasma glucose(PG) and plasma insulin (IRI) at 4 time points (0, 30, 60 and 120 min). Subjects were separated into two groups by their insulinogenic index (I.I. = delta IRI/delta PG from 0 up to 30 min), 99 cases with good insulin response (I.I. > or = 0.4) and 98 cases with poor insulin response (I.I. < 0.4). Only two subjects were diabetic in good insulin response, while 37 were diabetic in poor insulin response. The severity of coronary atherosclerosis was expressed as a coronary index (CI), calculated according to Balcon's method. Fasting PG and the sum of PG were significantly higher in the latter group, while the sum of IRI was significantly lower. CI was not significantly different, however. In the group with good insulin response, the severity of CAD was significantly correlated to fasting IRI (n = 99, r = -0.387, P < 0.02), but, there was no such relationship in the other group. We conclude that hyperinsulinemia might be a risk factor for ischemic heart disease, but in diabetics it is difficult to link the relationship between fasting IRI and CI.

Adult↗
PubMed1994

The taxonomy of the bovine Theileria spp.

The classification of the benign species of Theileria of cattle is very confusing Representatives of this group of parasites appear worldwide, and are known as T. sergenti in Japan, T. buffeli in Australia and T. orientalis elsewhere. Consequently, these parasites are frequently referred to as the T. sergenti/buffeli/orientalis group. Kozo Fujisaki, Shin-ichiro Kawazu and Tsugihiko Kamio here argue that the Australian T. buffeli and British T. orientalis belong to one and the same species, and that the Japanese T. sergenti is a separate species.

Journal Article↗
PubMed1994

Seroepidemiological studies of bovine babesiosis caused by Babesia ovata, B. bigemina and B. bovis in Peninsular Malaysia.

Cattle in Peninsular Malaysia were examined for evidence of infection with Babesia ovata, B. bigemina and B. bovis by an enzyme-linked immunosorbent assay for detection of antibody to the three Babesia species. All of the test samples when assayed with B. ovata antigen, resulted in low value indicating low probability of cattle infected with B. bigemina, 74.4% were positive for B. bovis and 72.6% were positive for both Babesia species. In addition, a serological survey with regard to age difference was carried out on a milk production farm. High reactivity antibody to B. bigemina and B. bovis was detected in calves less than 1 month of the age. The reactivity decreased in calves 1-3 months of the age. Then, the reactivity increased for both Babesia species in 6 months old calves. These results suggested that cattle infected with B. bigemina and B. bovis were widespread throughout Peninsular Malaysia and that both parasites might exist as an enzootical parasite.

Age Factors↗
PubMed1994

Uptake of remnant like particles (RLP) in diabetic patients from mouse peritoneal macrophages.

To investigate whether the remnant like particles (RLP), separated from serum by an immunoaffinity gel mixture of anti-apo B-100 and apo A-I monoclonal antibodies, are relevant to the initiation or progression of atherosclerosis, the incorporation of RLP into mouse macrophages was studied using histochemical and biochemical techniques. Remnant lipoproteins such as RLP are reported to contain a large quantity of chyloniron and very low density lipoprotein (VLDL) remnants, especially in diabetic patients. The RLP separated from the sera of 32 diabetic patients were found to be predominantly taken up into macrophages harvested from mouse abdominal cavities by the staining method applying oil red O. Furthermore, using 14C-oleate to prove the uptake of lipoproteins by macrophages, the uptake of RLP-VLDL, a VLDL fraction of RLP by ultracentrifugation, was the next highest to that of the oxidized LDL, which suggests that RLP-VLDL is also aggressively taken up by macrophages. The degree of uptake of RLP-VLDL by macrophages was positively correlated with HbA1c of these diabetic patients (r = 0.556, p < 0.01), irrespective of the ways of the treatment of diabetes. In conclusion, RLP can contribute to the foaming of macrophages, which in turn may explain the acceleration of atherosclerosis in diabetic patients.

Aged↗
PubMed1993

Antigen profiles of Anaplasma ovis and A. mesaeterum and cross infection trials with them and A. marginale.

Antigen profiles of Anaplasma ovis and A. mesaeterum were analysed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and immunoblotting, and cross infection trials were performed by A. ovis challenge to A. mesaeterum- or A. marginale-inoculated goats and A. marginale challenge to an A. ovis-inoculated calf. Antigen analysis showed unique and common proteins of A. ovis and A. mesaeterum and identified a major 38 kDa protein to be a dominant immunogen bearing two epitopes common to Anaplasma species. An epitope specific to A. ovis and A. marginale, absent from A. mesaeterum, was recognised on the major protein of A. ovis. Pre-inoculation of goats with A. mesaeterum induced continuous antibody response with low parasitemia and partial protection against A. ovis challenge, as demonstrated by lower peak parasitemia and normal body temperature compared with values for goats inoculated with A. ovis alone. Pre-inoculation of goats with A. marginale and a calf with A. ovis induced weak or no antibody response without parasitemia, and was of no effect for preventing anaplasmosis by heterologous challenge. These results suggest that the development of parasitemia is essential for inducing continuous antibody by which cross protection would be possible.

Anaplasma↗
PubMed1993

Apolipoprotein E metabolism in sciatic nerves of diabetic rats. Implication for diabetic neuropathy.

Apolipoprotein (apo) E secreted by macrophages plays an important role in nerve injury and repair. We investigated the disturbance of neural apo E metabolism in diabetic rats and its relation to diabetic neuropathy. In BB/W rats, genetically diabetes prone rats, the secretion of apo E from sciatic nerves was 3-fold greater than that in control rats. Furthermore, a similar enhancement of apo E secretion was observed in injured nerves of STZ-induced diabetic rats (2-fold) as compared with those of nondiabetic rats, and this was reversible with insulin treatment. Histological examination of the nerves revealed more extensive infiltration of mononuclear cells in the injured nerves of STZ-induced diabetic rats than in those of non-diabetic rats. This is consistent with the findings that chemotactic activities for mononuclear cells, which were released from injured nerves, were greater in the STZ-induced diabetic rats than in the non-diabetic rats. From these results we conclude that the recruitment of monocyte/macrophages into injured nerves is enhanced in diabetes, thereby causing derangement of neural apo E metabolism. These abnormalities might contribute to the development of diabetic neuropathy.

Adult↗
PubMed1993

Genistein augments cyclic adenosine 3'5'-monophosphate(cAMP) accumulation and insulin release in MIN6 cells.

Effects of genistein on insulin release were studied using MIN6 cells, a glucose-sensitive insulinoma cell line. At the non-stimulatory concentrations of glucose, genistein did not affect insulin release, however, at the stimulatory concentrations of glucose, genistein significantly increased insulin release in a dose-dependent manner up to 20 micrograms/ml. The content of cAMP in MIN6 cells was also elevated significantly by genistein and the dose-response relationship between the genistein and cAMP accumulation was consistent with the relationship between the genistein and insulin release. These effects were inhibited by calcium antagonists or by the omission of extracellular calcium. Isobutylmethylxanthine (IBMX;0.1mM) increased both cAMP accumulation and insulin release in MIN6 cells and there were no additive effects by the addition of genistein. The accumulation of cAMP might have, at least in part, resulted from phosphodiesterase inhibition by genistein. These results suggest that genistein augments glucose-induced insulin release by the contribution of cAMP accumulation and calcium modulation which depends on extracellular calcium.

1-Methyl-3-isobutylxanthine↗
PubMed1993

Histological observations on the schizonts in cattle infected with Japanese Theileria sergenti.

Histological observations were performed on the schizonts of Japanese Theileria sergenti in three calves necropsied 8 and 10 days after application of nymphal Haemaphysalis longicornis infected with T. sergenti. In all the three calves, schizonts were observed in the cytoplasm of huge cells formed in the drainage lymph nodes, liver and spleen. The huge cells were 50 to 200 microns in diameter. Schizonts had granular appearance and an irregular shape and were 1 to 7 microns in diameter. Ultrastructurally, schizonts had more than one nuclei and were formed in the unit enlarged cell. Schizonts showed a specific reaction against anti-T. sergenti anti serum, therefore, it was concluded that the schizonts were those of T. sergenti histologically.

Animals↗
PubMed1993

Theileria sergenti: transformation of zygotes into kinetes in vector ticks, Haemaphysalis (Kaiseriana) longicornis and H. (K.) mageshimaensis.

Invagination or transformation of a zygote of Theileria sergenti into a kinete was examined with Giemsa-stained smears of the midgut of vector ticks, Haemaphysalis longicornis and H. mageshimaensis. Zygotes invaginated almost simultaneously with the moulting of host ticks. They were round and oval, and measured 5.4 to 6.7 microns in diameter on average. The kinetes developing in the zygotes were situated in the periphery of cytoplasm and were spindle- or club-shaped.

Animals↗