Search PubMed⌕ Search

Biomedical subjects

S Kawazu

Publications and source records attributed to S Kawazu.

At least 73 records · Page 4Linked to original sources

Protein analysis of Strongyloides venezuelensis by two-dimensional polyacrylamide gel electrophoresis.

Infective larvae, larvae in the lung and adult-stage worms in the small intestine of Strongyloides venezuelensis were analysed for protein by two-dimensional gel electrophoresis. The infective larvae were differentiated from the other two stages of parasite with 13 stage-specific spots, whereas the larvae in the lung and the adult-stage worms were identical to each other in spot patterns except for 6 spots.

Animals↗

Appearance of a regenerating (reg) gene protein in pancreatic islets of remission BB/Wor//Tky rats.

Remission of diabetes, i.e. significant amelioration from absolute insulin-dependency, has been sometimes observed in diabetic BB/Wor//Tky rats which were treated with insulin. In remission BB/Wor//Tky rats, plasma glucose levels improved to near normal level and insulin content was also preserved as much as that between diabetic and non-diabetic rats. In this process, we hypothesized that autoimmune insulitis was suppressed and remaining islet B-cells was restored from severe destruction by recovering in number and/or function. While, recently, a novel regenerating (reg) gene, identified in the regenerating pancreatic islets of surgical models, is reported to be related to the replication of pancreatic B-cells in vitro. Based on these findings, we histologically investigated whether the reg protein could be actually expressed or not in the islets from remission BB/Wor//Tky rats. As expected, reg protein was observed in the islets from remission BB/Wor//Tky rats mainly in accordance with pancreatic B-cells. Thus, the present findings suggested that the regeneration of pancreatic B-cells represented by the expression of reg protein might be, at least in part, relevant to remission induced by insulin therapy in spontaneously occurring Type 1 diabetes in BB/Wor//Tky rats.

Animals↗

[Do blood glucose levels in the elderly have different metabolic significance than in non-elderly subjects?].

Diagnostic criteria of diabetes mellitus in elderly people are still controversial. The major questions are whether (1) effects of hyperglycemia in generating diabetic complications are the same as in younger diabetics, (2) too many diabetics might be diagnosed in the elderly by the criteria proposed by WHO and Japan Diabetes Society. To answer these questions, we carried out two studies. Blood glucose data were collected from population-based studies and from voluntary health check-up studies. Fasting blood glucose values were classified by sex and the age (-49, 50-64, 65-years old). Population-based studies showed no age-dependent change in blood glucose. However, data from health check-up studies showed an increase in median values from the group aged 50-64 and the 65 and older group. Two-hour values after glucose tolerance tests were classified by age and the fasting blood glucose (-99, 100-119, 120-139, and 140- mg/dl). The eldest and 140- mg/dl group showed the highest 2-hour values. Effects of hyperglycemia on the appearance of diabetic complications were studied in patients being follow-up in three diabetes clinics. Patients who has a history of one year or less and without any retinopathy on the first visit to the clinic were registered. Data were analyzed by the Kaplan-Meier method and the appearance of retinopathy was used as the end point. There were no difference in the rate of appearance of retinopathy between the age groups (-49, 50-64 and 65-years old). No age effect on the hyperglycemia-dependent appearance of retinopathy could be observed.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

Effect of age on the development or progression of albuminuria in non-insulin-dependent diabetes mellitus (NIDDM) without hypertension.

To study the relationship between aging and development of diabetic nephropathy, we studied the time until the development of microalbuminuria in old onset (> 50 years old, n = 21) and young onset (< 40 years old, n = 26), normotensive NIDDM patients. Microalbuminuria which is associated with the early stage of diabetic nephropathy was defined as urinary albumin index (UAI; mg/g.creatinine) of more than 10mg/g.creatinine, using timed overnight urine. In these two groups, there were no significant differences in duration of diabetes, observation periods, glycemic control, systolic diastolic blood pressure, body mass index and creatinine clearance at the time of the last observation. Mean UAI +/- standard deviation of the two groups were 37.5 +/- 78.2 mg/g.cr and 93.0 +/- 127.2 mg/g.cr in the young onset group and the old onset group, and prevalences of microalbuminuria were 38% and 76% in the young onset and old onset group, respectively. Thus, UAI and prevalence of microalbuminuria in the old onset group are significantly higher than those of the young onset group (P < 0.05). These results suggest that aging, in itself, is one of the significant risk factors for the development of diabetic nephropathy in NIDDM patients.

Age of Onset↗

Antigenic differences between Japanese Theileria sergenti and other benign Theileria species of cattle from Australia (T. buffeli) and Britain (T. orientalis).

Serological comparisons among piroplasm antigens of the benign Theileria species of cattle from Japan, Australia and Britain, which are frequently referred to as T. sergenti, T. buffeli and T. orientalis, were carried out. The results obtained from comparative enzyme-liked immunosorbent assay (ELISA) using sera from infected cattle suggest that T. sergenti could be differentiated from both T. buffeli and T. orientalis by their serological dissimilarities. Western blotting combined with two-dimensional polyacrylamide gel electrophoresis (2D-PAGE) revealed that both the 33-kDa piroplasm protein of T. sergenti and the similar 34-kDa protein of T. buffeli and T. orientalis corresponded to immuno-dominant antigens against cattle. The other 32-kDa proteins of . T. buffeli and T. orientalis also represented immunodominant antigens. Cross-reactivities of the 32-and 34-kDa proteins were observed between T. buffeli and T. orientalis, whereas the 33-kDa protein of T. sergenti could be differentiated from the similar 34-kDa proteins of T. buffeli/orientalis. The present study suggests that T. sergenti should be separated from T. buffeli and T. orientalis on the basis of their serological dissimilarities.

Animals↗

Analysis of the genes encoding immunodominant piroplasm surface proteins of Theileria sergenti and Theileria buffeli by nucleotide sequencing and polymerase chain reaction.

The nucleotide sequences of the cDNAs encoding a 33-kDa piroplasm protein of Theileria sergenti (p33) and a similar protein of Theileria buffeli (p34) were determined. Both of the genes contained an open reading frame of 849 base pairs. The predicted amino acid sequence of p33 and p34, consisting of 283 residues, showed 82% similarity. A transmembrane hydrophobic domain and signal peptides were predicted. The polymerase chain reaction was used to amplify p33/34 genes from the piroplasm DNA of T. sergenti, T. buffeli and Theileria orientalis. Following amplification, p33 and p34 genes were clearly differentiated using the restriction enzymes sites that were not shared between them. These results indicated that p33 and p34 were conserved molecules among these Theileria species, and the genes that encode p33/34 proteins were suitable for discrimination of T. sergenti from T. buffeli/T. orientalis.

Amino Acid Sequence↗

Preliminary biochemical characterization of 'veil' structure purified from Theileria sergenti-, T. buffeli- and T. orientalis-infected bovine erythrocytes.

A structure called 'veil' in Theileria sergenti-, T. buffeli- or T. orientalis-infected bovine erythrocytes was purified from erythrocyte lysates by Percoll density-gradient centrifugation. On electron microscopical examination, the veils consisted of electron-dense material showing a periodicity of striations and were not surrounded by membranes. Analyses of veil proteins by one- and two-dimensional polyacrylamide gel electrophoresis revealed that the veils contain haemoglobin and several other basic proteins of molecular weight ranging from 15.5 to 46 kDa. By comparing the protein patterns of the veil with those of purified piroplasms and uninfected bovine erythrocytes, these basic proteins appeared to be of parasite origin. It would appear likely that the veils formed by intra-erythrocytic precipitation of haemoglobin and proteins excreted by the parasites. Differences in veil constituents were found between T. sergenti, T. buffeli and T. orientalis.

Animals↗

Molecular cloning and immunological analysis of immunodominant piroplasm surface proteins of Theileria sergenti and T. buffeli.

cDNA libraries of Theileria sergenti and T. buffeli piroplasms were constructed in lambda gt11 and screened with rabbit anti-piroplasm sera. A major antigen of T. sergenti (33 kDa) and that of T. buffeli (34 kDa) was identified from the recombinant phages by using recombinant antigen-selected monospecific antibodies. The reactivities of the cloned proteins with rabbit antisera, infected calf sera and mouse monoclonal antibody suggested that the 33 and 34 kDa proteins expressed species-common and species-specific epitopes. The DNA probes from these recombinant clones showed species-specific hybridizations in Southern blotting with genomic DNA from piroplasms. These results indicate that the Japanese T. sergenti can be distinguishable from the Australian T. buffeli with regard to a polymorphism of the major immunodominant proteins of piroplasm.

Animals↗

A new animal model of non-insulin-dependent diabetes mellitus induced by the NDK25 variant of encephalomyocarditis virus.

Intraperitoneal inoculation with NDK25, a variant of Encephalomyocarditis (EMC) virus which has been newly cloned from the M variant of EMC virus (EMC-M), caused DBA/2 mice to develop noninsulin-dependent diabetes mellitus. The NDK25-infected mice demonstrated abnormal glucose tolerance from 1 to 3 weeks after inoculation. The infection resulted in mild insulitis and the destruction of pancreatic beta cells at 1 week after inoculation and led to a significant reduction in the insulin content of the pancreas, but there was no ketonuria. The insulin content of the pancreas was recovered considerably from 15 +/- 3 at 1 week to 95 +/- 16 micrograms/g pancreas at 12 weeks, although the latter value was still significantly lower than that of the control mice (P < 0.05). Under microscopy, mild and partial infiltration of mononuclear cells was observed in about half the pancreatic islets only 1 week after inoculation, and then disappeared. Thus, we believe we have established a new model of noninsulin-dependent diabetes mellitus using the NDK25 variant of EMC virus.

Animals↗

Purification of merozoites of Theileria sergenti from infected bovine erythrocytes.

A simple and rapid method for purifying merozoites of Theileria sergenti from infected bovine erythrocytes was developed. Infected erythrocytes were lysed by the use of a cytolytic toxin produced by Aeromonas hydrophila and the lysate was subjected to ultracentrifugation in a Percoll discontinuous density gradient. Pure and morphologically intact merozoites free of erythrocyte membrane were recovered from a band formed at the interface of 40% and 60% (by vol.) Percoll solutions. In this merozoite fraction, contamination of erythrocyte membrane proteins was not detected as examined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis.

Aeromonas↗

Effect of dietary calcium on renal prostaglandins.

The present study was designed to clarify the possible role of renal prostaglandins (PGs) on blood pressure (BP) regulation during calcium (Ca) restriction or supplementation. Twelve normotensive women with a mean age of 21.2 years participated in the study. After 1 week of normal Ca intake (mean +/- SE, 536 +/- 2 mg/day), a low-Ca diet (163 +/- 1 mg/day) was given for a further 1 week. Additional asparagine Ca (3 g as Ca/day) was also given to half of the subjects. BP, heart rate, and serum total and ionized Ca concentrations were measured at the end of each period. Levels of Ca, sodium, PGE2, 6-keto-PGF1 alpha and thromboxane (TX) B2 excreted into urine were also determined. The plasma level of ionized Ca was significantly increased without any change in total Ca in both groups. Low and high Ca intake decreased and increased urinary Ca excretion by 28% and 56%, respectively. BP was not altered after Ca deprivation or loading. However, urinary PGE2 excretion was significantly augmented from 668.9 +/- 68.1 to 959.7 +/- 183.1 ng/day by Ca loading, whereas Ca deprivation decreased PGE2 excretion (695.4 +/- 108.1 to 513.2 +/- 55.2 ng/day). No changes were observed in 6-keto-PGF1 alpha or TXB2 urinary excretion. These results suggest that renal PGE2 synthesis is stimulated or decreased by 1-week Ca loading or deprivation, indicating a possible antihypertensive role of renal PGE2 during high-Ca intake in hypertensives.

6-Ketoprostaglandin F1 alpha↗

Protein analysis of Theileria sergenti/buffeli/orientalis piroplasms by two-dimensional polyacrylamide gel electrophoresis.

Proteins of the piroplasms of Theileria sergenti, T. buffeli and T. orientalis were analysed by two-dimensional polyacrylamide gel electrophoresis. Protein spot patterns of T. buffeli and T. orientalis were identical except for a few minor proteins, whereas spot patterns of two T. sergenti stocks were differentiated from those of T. buffeli and T. orientalis by a characteristic set of proteins including a major protein of molecular weight 33-34 kDa. This result indicates that Japanese T. sergenti can be phenotypically distinguishable from European and Australia Theileria species; T. orientalis and T. buffeli.

Animals↗

Analysis of protein compositions and surface protein epitopes of Anaplasma centrale and Anaplasma marginale.

Protein composition was compared and epitopes were analyzed among the isolates of Anaplasma centrale and A. marginale by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, immunoblotting using bovine antisera and monoclonal antibodies, and enzyme-linked immunosorbent assay. Common and unique proteins were found among the isolates. All isolates tested had a major surface protein with an apparent molecular weight of 38 to 40 kilodalton which had slight molecular size variations between species. This protein was also a dominant immunogen to the host. At least two species-common epitopes, one of which might contain carbohydrate(s), were present on the major surface protein. One species-specific epitope was identified on the major surface protein of A. marginale isolates.

Anaplasma↗

Effect of dietary calcium on serum BGP (osteocalcin).

The present study was designed to clarify the effects of dietary calcium (Ca) intake on serum BGP (osteocalcin) levels. Twelve women with a mean age of 21.2 years participated in the study. After one week of normal Ca intake (mean +/- SE, 535 +/- 2 mg/day), a low-Ca diet (163 +/- 1 mg/day) was given for one further week. Additional asparagine Ca (3 g as Ca/day) was also given to half of the subjects. Serum total and ionized Ca concentrations as well as BGP, PTH and 1,25(OH)2D3 were measured at the end of each period. Amounts of Ca and hydroxyproline excreted in urine were also determined. The plasma level of ionized Ca was significantly increased without any change in total Ca in either group. Low and high Ca intake decreased and increased urinary Ca excretion by 28% and 56%, respectively. Serum levels of BGP and 1,25(OH)2D3 were significantly augmented along with a transient increase in urinary hydroxyproline excretion after Ca deprivation. These results suggest that serum BGP is increased after one week of Ca restriction in healthy subjects.

Adult↗

Disturbance of thyroidal iodine metabolism in BB/W rat.

To investigate the thyroid function in Bio-Breeding Worcester (BB/W) rats, we have examined the iodine metabolism, serum TSH and thyroid hormone levels in 8- and 16-week-old BB/W and normal Wistar (W) rats. At 8 weeks of age, serum TSH levels were significantly higher in BB/W rats than in W rats, although there was no difference in the serum levels of free T3 and free T4. Furthermore, the thyroidal radioactive iodine incorporation at 48 h was significantly lower in BB/W rats, suggesting that they might have some defects in iodine organification. At 16 weeks of age, serum TSH levels were also significantly higher in BB/W rats than in W rats. Furthermore, serum TSH levels in 16-week-old BB/W rats were significantly higher than in 8-week-old BB/W rats. The thyroid weight was significantly greater in BB/W rats, probably due to the increased serum TSH. The thyroidal radioactive iodine uptake at 48 h and the iodine content in the thyroid homogenates were significantly lower in BB/W rats. These results suggest that BB/W rats have some defect in iodine metabolism resulting in impaired thyroid hormone synthesis.

Animals↗

Salmon calcitonin induces pituitary tumor in rats.

Calcitonin is widely used in the treatment of post-menopausal osteoporosis. The present study was designed to investigate the effects of salmon calcitonin (SCT) on the incidence of the pituitary tumors in Sprague-Dawley (SD) rats. Subcutaneous injections of SCT at a dose of 160 IU/kg/day for 6 months reduced body weight and induced one pituitary hyperplasia and three pituitary adenomas in 4 of 5 animals, while 5 controls did not show any changes. Prolactin-positive cells were located at the periphery of the affected pituitaries adjacent to the prolactin-negative adenomas. In addition, serum concentrations of prolactin and TSH were lower than in the controls, although serum calcium or LH levels were not significantly different from the controls. Among 7 animals treated with SCT for 6 months followed by no medication for another 6 months, 5 adenomas were detected, one of which had invasive growth toward the adjacent tissue, whereas only one adenoma was found in 9 controls. These results suggest that SCT administration at a high dose may induce the formation of pituitary adenoma, or may accelerate the development of spontaneous pituitary adenomas, some of which show frequent mitotic figures and invasive growth into the surrounding tissue, possibly resulting in malignant transformation. This indicates the need for caution in considering whether calcitonin injections into patients with osteoporosis as well as Paget's disease may induce such pituitary tumors.

Adenoma↗