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Biomedical subjects

T Nakao

Publications and source records attributed to T Nakao.

At least 55 records · Page 3Linked to original sources
PubMed2000

Changes in concentrations of plasma immunoreactive follicle-stimulating hormone, luteinizing hormone, estradiol-17beta, testosterone, progesterone, and inhibin in heifers from birth to puberty.

This study was designed to clarify the characteristics of changes in plasma concentrations of reproductive hormones in heifers from birth to puberty. Weekly or daily hormonal changes were observed in 39 heifers. Daily changes in the concentration of follicle-stimulating hormone (FSH) demonstrated a consistent cycle of hormone changes over a 7- to 8-day period in heifers from approximately 10 days to 9 months old. Weekly changes in reproductive hormones showed that there were three brief periods in heifers between birth and puberty in which dramatic changes occur. The first period was the first week after birth, during which a reciprocal relationship between steroid hormones and gonadotropins was observed. At birth, the concentrations of steroid hormones were higher than those at any other age. These hormone levels rapidly decreased within the first week after birth. Gonadotropin levels, however, increased from birth to 1 week of age. The second period of major change was at approximately 4 weeks of age when there was an increase in the concentrations of luteinizing hormone (LH), estradiol-17beta, testosterone, and immunoreactive inhibin. The third period was the last 5 weeks before the first ovulation, when there was an increase in the concentrations of estradiol-17beta followed by an increase in (LH). These results suggest that regular hormone changes start from 10 days after birth and that the periods from birth to 4 weeks of age and the last 5 weeks before the first ovulation in heifers are important to the development of reproductive functions before puberty.

Animals↗
PubMed2000

Nephrotic syndrome caused by protein thrombi in glomerulocapillary lumen in Waldenström's macroglobulinaemia.

Waldenström's macroglobulinaemia (WM) is described as a disorder of plasmacytoid lymphocytes. The renal complications of WM are less common and severe than those of multiple myeloma. We present a case of WM complicated by nephrotic syndrome. A biopsy specimen of the kidney revealed the intraglomerular thrombi of immunoglobulin M paraprotein. Corticosteroid pulse therapy and plasmapheresis were effective in improving proteinuria and reducing protein thrombi. The nephrotic syndrome caused by protein thrombi in WM may be reversible, at least in its early stage.

Aged↗
PubMed2000

Fecal estrone sulfate profile of a sow showing abnormal pregnancy with fetal mummification.

Fecal and plasma E1S of a sow with mummified fetuses, was compared with normal delivery cases. Fecal and plasma fluctuation patterns in E1S were similar. In the sow with fetal mummification both fecal and plasma E1S concentration rapidly decreased after day 80-90 compared to normal farrowing sows. This coincided with the estimated time of fetal death.

Abortion, Missed↗
PubMed2000

Leptin receptor and leukemia.

The receptor for leptin, the gene product of the obese gene, is expressed in hematopoietic stem cells. Leptin stimulates normal myeloid and erythroid development, and is secreted from bone marrow adipocytes, which occupy most of the marrow cavity in humans. Leptin might thus play an important role in the control of the expansion and differentiation of primitive hematopoietic cells through paracrine interaction in the bone marrow microenvironment. Leukemic cells of some patients with acute myeloblastic leukemia, acute lymphoblastic leukemia, and chronic myeloid leukemia (CML) also express the leptin receptor. In cases of CML, higher expression of leptin receptor is observed during blast crisis than in chronic phase. Leptin alone and in combination with other cytokines has stimulative effects on proliferation of leukemia cells as well as anti-apoptotic effects. These findings suggest the possibility that leptin plays roles in the pathophysiology of leukemia.

Carrier Proteins↗
PubMed2000

[A nevoid basal cell carcinoma syndrome with chromosomal aberration].

We reported a boy with nevoid basal cell carcinoma syndrome (NBCCS) with chromosomal aberration. He showed multiple jaw cysts, basal cell carcinomas, hypertelorism, macrocephaly and mental retardation. Cranial CT revealed calcification of the falx cerebri and tentorium cerebelli, and dilatation of the lateral ventricles. MRI showed a thin corpus callosum. A chromosomal study revealed a deletion of 9q21.31-q22.31. He had generalized tonic-clonic seizures, which were well controlled. Since the gene for NBCCS was recently mapped to chromosome 9q22.3, we suspected that the deletion site in this patient was responsible for his symptoms of NBCCS.

Basal Cell Nevus Syndrome↗
PubMed2000

[Effect of dietary protein restriction and influence of proteinuria on progression of type 2 diabetic renal failure].

PURPOSE: This study investigated the effect of dietary protein restriction on disease progression and how it is influenced by proteinuria in patients with type 2 diabetic nephropathy(DN) and renal failure. METHODS: One hundred and six type 2 DN patients whose baseline creatinine clearance(Ccr) values were 29 +/- 12 ml/min/1.73 m2 were maintained on a diet containing 0.66 +/- 0.05 g/kg/day of protein. They were classified into 3 groups according to mean dietary protein intake(DPI) estimated from urinary urea nitrogen excretion during the follow-up period of 23 +/- 14 months(I, < 0.7 g/kg/day; II, 0.7-0.89 g/kg/day; III, > or = 0.9 g/kg/day). Furthermore, they were divided into 3 subgroups according to mean urinary protein excretion(UP) during the follow-up period (a, > or = 5.0 g/day; b, 2.0-4.99 g/day; c, < 2.0 g/day). Their rates of decline of Ccr(D-Ccr) and the changes in UP were examined. RESULTS: There were no significant differences in D-Ccr among Group Ia, IIa, and IIIa(1.1 +/- 0.6, 1.5 +/- 0.7, 1.2 +/- 0.6 ml/min/1.73 m2/month), among Group Ib, IIb, and IIIb(0.6 +/- 0.3, 0.7 +/- 0.4, 0.8 +/- 0.4 ml/min/1.73 m2/month), and also among Group Ic, IIc, and IIIc(0.1 +/- 0.3, 0.2 +/- 0.2, 0.2 +/- 0.6 ml/min/1.73 m2/month). On the other hand, significant differences were revealed in D-Ccr among Group Ia, Ib, and Ic, among Group IIa, IIb, and IIc, and among Group IIIa, IIIb, and IIIc. There were no significant differences in final UP and minimum UP during follow-up among 3 groups of different DPI levels in patients with 5.0 g/day < or = baseline UP(n = 49) and in patients with 2.0 < or = baseline UP < 5.0 g/day(n = 37). However, significant correlations were demonstrated between D-Ccr and the relative changes in UP between baseline and minimum during the follow-up period in both patients(r = 0.49, 0.48, p < 0.001, p < 0.01). CONCLUSIONS: Irrespective of the level of dietary protein restriction, proteinuria has a great influence on disease progression, and the reduction in UP correlates with retardation of renal function loss in patients with type 2 DN and renal failure.

Aged↗
PubMed1999

Effects of ortho-substituent groups of sulochrin on inhibitory activity to eosinophil degranulation.

Sulochrin, a metabolite of fungi, has been shown to have an inhibitory activity to eosinophil degranulation. A series of sulochrin derivatives substituted at ortho-positions to the 10-carbonyl group was examined the activity. The importance of alkylester at C-6 position and several chemical properties of substituted groups at ortho-positions to exhibit activity are described.

Anti-Allergic Agents↗
PubMed1999

Screening of marine microalgae for bioremediation of cadmium-polluted seawater.

Twenty four strains out of 191 marine microalgal strains exhibited cadmium (Cd) resistance. They were tested for their Cd removal ability in growth media containing 50 microM Cd. Six strains out of 19 green algae and one out of five cyanobacteria removed more than 10% of total Cd from the medium. The marine green alga Chlorella sp. NKG16014 showed the highest removal of Cd 48.7% of total. Cd removal by NKG16014 was further quantitatively evaluated by measuring the amount of cell adsorption and intracellular accumulation. After 12 days incubation, 67% of the removed Cd was accumulated intracellularly and 25% of the Cd removed was adsorbed on the algal cell surface. The maximum Cd adsorption (qmax) was estimated to be 37.0 mg Cd (g dry cells)-1 using the Langmuir sorption model. The Cd removal by freeze-dried NKG16014 cells was also determined. Cd was more quickly adsorbed by dried cells than that by living cells, with a qmax of 91.0 mg Cd (g dry cells)-1.

Biodegradation, Environmental↗
PubMed1999

The relationship between plasma oestrone sulphate concentrations in pregnant dairy cattle and calf birth weight, calf viability, placental weight and placental expulsion.

A total of 54 Holstein-Friesian cows (13 primiparous and 41 multiparous) was used to study maternal plasma oestrone sulphate (E1S) during pregnancy and its relationship to birth weight and viability of calves and time required for placental expulsion after calving. Plasma samples were obtained from the tail vein of cows once every month from days 90 to 180, every 2 weeks from days 181 to 270, and every day from day 270 of gestation to parturition. The E1S concentrations were measured by radioimmunoassay, and birth weight, placental measurements, neonatal viability and the period from calving to placental expulsion were recorded. E1S concentrations were correlated positively (0.71 > or = r > or = 0.32, P < 0.05 or P < 0.01) with calf birth weight and weights of cotyledons, intercotyledonary membranes and total placenta from days 210 of gestation to 1 day prepartum. Calf birth weight was correlated positively (p < 0.01) with the weight of the cotyledons (r = 0.87), intercotyledonary membranes (r = 0.78) and total placenta (r = 0.88). In addition, E1S concentrations were positively correlated (0.63 > or = r > or = 0.28, P < 0.05 or P < 0.01) with the neonatal viability after day 195 of pregnancy, and were negatively correlated (-0.29 > or = r > or = -0.55, P < 0.05 or P < 0.01) with the intervals from parturition to placental expulsion after 225 days of pregnancy. The results suggest that variation among dams for circulating E1S levels during late pregnancy may be caused by variation of placental development and ability for oestrogen production and conjugation, and they may influence fetal growth, neonatal viability and retained placenta.

Animals↗
PubMed1999

Inhibition of GABA system involved in cyclosporine-induced convulsions.

In this study, we attempted to clarify the mechanisms mediating cyclosporine-evoked convulsions. Cyclosporine (50 mg/kg, i.p.) significantly enhanced the intensity of convulsions induced by bicuculline (GABA receptor antagonist), but not those induced by strychnine (glycine receptor antagonist), N-methyl-D-aspartic acid, quisqualic acid or kainic acid (glutamate receptor agonists). Bicuculline plus cyclosporine-induced convulsions were significantly suppressed by an activation of GABAergic transmission with diazepam, phenobarbital and valproate. The GABA turnover estimated by measuring aminooxyacetic acid-induced GABA accumulation in the mouse brain was significantly inhibited by cyclosporine (50 mg/kg, i.p.). When cultured rat cerebellar granule cells were exposed to 1 microM cyclosporine for 24 hr, the specific [3H]muscimol (10 nM) binding to intact granule cells decreased to 53% of vehicle controls. The present study provides the first evidence suggesting that cyclosporine inhibits GABAergic neural activity and binding properties of the GABAA receptor. These events are closely related to the occurrence of adverse central effects including tremors, convulsions, coma and encephalopathy under cyclosporine therapy.

Animals↗
PubMed1999

Induction of autologous graft-versus-host disease after autologous peripheral blood stem cell transplantation.

BACKGROUND: Autologous graft-versus-host disease has been reported after the administration of cyclosporine in patients who have received autologous bone marrow transplantation. OBJECTIVE: The purpose of this study was to determine whether autologous graft-versus-host disease could be induced in recipients of autologous peripheral blood stem cell transplantation and whether tacrolimus induced the disease instead of cyclosporine. METHODS: Twelve patients with acute leukemia and 5 patients with malignant lymphoma received either cyclosporine (1 mg/kg/day) or tacrolimus (0. 05 mg/kg/day) orally after autologous bone marrow or peripheral blood stem cell transplantation. RESULTS: Autologous graft-versus-host disease of the skin, confirmed by histopathologic criteria, occurred in 40% of the patients at 8 to 25 days after transplantation and lasted 3 to 15 days. The frequency of autologous graft-versus-host disease was approximately the same (40%) irrespective of the source of the graft (bone marrow cells or peripheral blood stem cells) and the drug used for induction (cyclosporine or tacrolimus). CONCLUSIONS: This pilot study suggests that autologous graft-versus-host disease can be induced in recipients of autologous peripheral blood stem cell transplantation by cyclosporine or tacrolimus.

Acute Disease↗
PubMed1999

Intrauterine growth retardation as a cause of perinatal mortality in Japanese black beef calves.

Perinatal death is one of the major causes of calf mortality in Japanese Black beef herds. A series of experiments were carried out to determine causes of perinatal calf mortality in a region of northern Japan. An aetiological survey revealed that the incidence of perinatal mortality in 6475 calves was 4.5% and the majority of neonatal deaths were caused by weak calf syndrome. The weak calves delivered after a normal gestation period had a significantly lower body weight at birth than normal calves (P < 0.01), indicating growth retardation in the uterus during pregnancy. Haematological and histopathological examinations showed that the weak calves had anaemia characterized by a significant decrease of blood cell values and bone marrow hypofunction. The anaemia due to bone marrow hypofunction presumably caused intrauterine growth retardation of the foetus. Dams delivering the weak calves showed significantly lower serum concentrations of estrone sulphate during late pregnancy than those with normal calves (P < 0.01), indicating foeto-placental dysfunction as a possible cause of growth retardation. Effects of sires as well as the maternal family on the incidence of neonatal death and on the rate of weak calves in dead neonates were found in the survey. Intrauterine growth retardation associated with anaemia may be the most important cause of weak calf syndrome in Japanese Black beef calves. The bull and maternal family may also have an influence on the incidence of neonatal death.

Anemia↗
PubMed1999

Low-density lipoprotein apheresis retards the progression of hyperlipidemic overt diabetic nephropathy.

BACKGROUND: Hyperlipidemia has recently received attention as being involved in the progression of diabetic nephropathy (DN). Low-density lipoprotein apheresis (LDL-A) can remove a large amount of plasma lipid directly from the patients in a short time. METHODS: Fifteen type 2 diabetic patients with overt nephropathy received LDL-A in two different manners: short-term intensive therapy (SIT) for nine patients and long-term intermittent therapy (LIT) for six patients. RESULTS: The changes in the monthly decline rates of reciprocal serum creatinine (1/Cr) were -0.035 +/- 0.020 in the three-month period before SIT, 0.047 +/- 0.041 during and until two weeks after SIT, and -0.035 +/- 0.015 after a period of two weeks from the therapy. The mean duration of LIT in six patients was 8.2 +/- 7.4 months, and the mean monthly decline rates of 1/Cr significantly decreased during the period of LIT as compared with the six-month period before the treatment. CONCLUSION: LDL-A can retard the progression of overt DN, especially when it is performed repeatedly for a long period at two-week intervals.

Aged↗