Search PubMed⌕ Search

Biomedical subjects

Y Nagura

Publications and source records attributed to Y Nagura.

At least 19 recordsLinked to original sources
PubMed2005

Effect of active immunization against inhibin on hormonal concentrations and semen characteristics in Shiba bucks.

Active immunization against inhibin increased ovulation rate in females; in males, the effects of active immunization against inhibin on hormonal concentrations and sperm production need more investigation. To test the hypothesis that active immunization against inhibin increases FSH secretion and sperm output, the present study was undertaken to determine the effects of active immunization against inhibin on hormonal profile and sperm production in Shiba bucks. The bucks were actively immunized against inhibin alpha-subunit (immunized group, n=6) or Freund adjuvant (control group, n=5) four times, at 5-weeks intervals. Blood samples were collected twice-weekly and two successive ejaculates of semen were collected (with an artificial vagina) once-weekly. Plasma concentrations of FSH, LH and testosterone were measured by radioimmunoassay (RIA) and sperm motility characteristics were measured by computer-assisted sperm analysis (CASA). All inhibin-immunized bucks produced antibodies against inhibin. Relative to control bucks, in immunized bucks there were significant increases in plasma FSH concentrations and in sperm concentrations from 5 to 9 weeks and from 8 to 11 weeks, respectively, after primary immunization. However, plasma concentrations of LH and testosterone, semen volume, percentage of motile spermatozoa and motility parameters (straight-line velocity, curvilinear velocity and linearity index) were similar in both groups. In conclusion, active immunization against inhibin alpha-subunit increased FSH secretions and enhanced sperm production in bucks, whereas LH and testosterone concentrations, semen volume and sperm motility parameters were unaffected. Active immunization against inhibin could be used to improve fertility in Shiba bucks.

Animals↗
PubMed2003

Ovarian and hormonal response of female goats to active immunization against inhibin.

This study was conducted to evaluate the effect of active immunization against inhibin on hormonal levels and the ovulation rate in goats. Ten adult Shiba goats (Capra hircus) in two groups were used in this study. The first group was injected with inhibin vaccine (immunized, n=5) and the second group was injected with Freund's adjuvant (control, n=5) followed by three booster injections at 4-week intervals. After the third booster injection, three consecutive periods of oestrus were induced using prostaglandin F(2alpha) at intervals of 11 days. Blood samples were collected at 2-6 h intervals and the ovaries were monitored using B-mode ultrasonography. All inhibin-immunized goats generated antibodies that bound (125)I-labelled bovine inhibin and their FSH concentrations were significantly higher than corresponding values in the control group. Also, inhibin-immunized goats had significantly higher preovulatory oestradiol-17beta (P<0.01) and higher concentrations of progesterone in the luteal phase (P<0.05). Immunization of goats against inhibin resulted in a significant (P<0.01) increase in ovulation rate (control: 1.7+/-0.3 vs immunized: 7.6+/-1.1). These results demonstrate that active immunization against inhibin enhances ovarian follicular development and ovulation rate by promoting an increase in pituitary FSH secretion. Therefore, immunization against inhibin may be a useful alternative to the conventional approach of superovulation in goats.

Animals↗
PubMed2003

Effects of passive immunization of goats against inhibin on follicular development, hormone profile and ovulation rate.

This study was conducted to investigate the effect of immunoneutralization against endogenous inhibin on FSH secretion and ovulation rate, with the aim of developing a new superovulation method using inhibin antiserum in goats. Two groups of goats received an i.v. injection of either 10 ml normal goat serum (control; n = 6) or 10 ml inhibin antiserum developed against [Tyr(30)]-inhibin alpha (1-30) (n = 6) 48 h before treatment with prostaglandin F(2alpha) (PGF(2alpha)). Blood samples were collected at 6 h intervals and ovaries were examined each day using a B-mode ultrasound scanner equipped with a 7.5 MHz transducer during the experimental period. Immunization against inhibin resulted in a four- to fivefold increase (P < 0.01) in plasma concentrations of FSH. After luteolysis, plasma concentrations of oestradiol increased markedly to reach a preovulatory peak, which was about two times higher (P < 0.01) than that of the controls. The treatment was accompanied by a significant increase in the total number of follicles of > or = 3 mm in diameter at 24 (8.2 +/- 0.4 in inhibin antiserum group versus 4.8 +/- 0.3 in control group) and 96 h later (13.5 +/- 1.0 in inhibin antiserum group versus 5.3 +/- 0.6 in control group). The ovulation rate was significantly (P < 0.01) higher in goats treated with inhibin antiserum (4.2 +/- 0.5; n = 6) than in control goats (1.8 +/- 0.3; n = 6). These results indicate that inhibin is an important factor in the regulation of FSH secretion in goats and demonstrate that passive immunization against inhibin at 48 h before treatment with PGF(2alpha) induces the development of more follicles and increases ovulation rate. Thus, inhibin antiserum treatment may be an alternative to the use of exogenous gonadotrophins for induction of superovulation in goats.

Animals↗
PubMed2001

Intravascular ultrasound imaging before and after angioplasty for stenosis of arteriovenous fistulae in haemodialysis patients.

BACKGROUND: Complications of haemodialysis vascular access have emerged as a major cause of patient morbidity. Intravascular ultrasound imaging is a new technical modality providing visualization of the vessel lumen and wall structure in a cross-sectional fashion. Percutaneous transluminal angioplasty has long been used in the treatment of stenoses of arteriovenous fistulae. However, there is no detailed quantitative information on the stenotic lesion and the morphological change by angioplasty. METHODS: Intravascular ultrasound studies were performed in 40 haemodialysis patients with 63 stenoses in arteriovenous fistulae who had percutaneous transluminal angioplasty. The patients were qualitatively and quantitatively evaluated for echogenic patterns and morphological changes before and after angioplasty. RESULTS: Morphological plaque features in stenotic lesions were classified as 37 soft (58%), five hard (8%), 20 mixed (32%), and one calcified sites. Plaque fractures after angioplasty were detected in 45/63 (71%) instances. The lumen cross-sectional area was found to be dilated approximately threefold (from 3.8+/-2.4 to 11.1+/-4.5 mm(2)) and the external elastic membrane cross-sectional area was dilated approximately twofold (from 11.1+/-5.3 to 19.8+/-8.1 mm(2)) after angioplasty. CONCLUSION: These results indicate that intravascular ultrasound allows both qualitative and quantitative assessments of arteriovenous fistulae in haemodialysis patients. The results further suggest that the mechanism of expansion of arteriovenous fistulae stenoses by percutaneous transluminal angioplasty involves stretching of the vessel wall as well as plaque fractures.

Adult↗
PubMed2001

Relationship between insulin resistance and uremic toxins in the gastrointestinal tract.

The relationship between insulin resistance and local uremic toxins was examined using an oral adsorbent. Fourteen rats demonstrating a diabetic state underwent two-thirds, nephrectomy and were divided into two groups. The control group was fed standard rat chow, and the test group was fed standard rat chow containing 5% AST-120. The target level of blood glucose was achieved by controlling the dosage of exogenous insulin. All rats were sacrificed at week 6. Body weight, blood glucose level, and renal function at week 6 were not significantly different between both groups. However, the mean blood glucose level and the mean dose of exogenous insulin in the AST-120-fed group were significantly reduced as compared with the control group. The results of the present study indicate that administration of an oral adsorbent in diabetic nephropathy decreases the doses of exogenous insulin and improves insulin resistance, and that uremic toxins which exist in the gastrointestinal tract play important roles.

Adsorption↗
PubMed2000

[Phosphate kinetics in patients on chronic hemodialysis].

To investigate the phosphate kinetics in hemodialysis (HD), 8 patients in a stable condition, who were receiving HD three times a week for 4 hours per session, were investigated. Plasma phosphate was under 7 mg/dl, and residual renal function had almost disappeared. Dialysate containing phosphate was prepared by adding Na2HPO4 using a micro-infusion pump from the inlet of single pass dialysate in the individual dialysate delivery system. In the first week, Na2HPO4 was not added as the control period. In the second session of the second and third week, Na2HPO4 was added to give a phosphate concentration of 1.0 and 2.0 mmol/l in the dialysate, respectively. Total phosphate mass removal was 777 +/- 46.64 mg in the control period, 403 +/- 67.21 mg in the second week, and -230 +/- 214.8 mg in the third week. Total phosphate mass removal in the second and third week was significantly lower than that of the control period. Plasma phosphate concentration was significantly decreased after the HD compared with before the HD in the control and second week. There was no significant difference in plasma phosphate concentration between the period before HD and at 48 hours in the control and the second week. Plasma phosphate concentration before HD not only depended on phosphate mass removal by HD, but also on other factors. We suggest that dialysate containing phosphate might prevent excessive phosphate removal from non-extracellular compartments during HD.

Adult↗
PubMed1998

[The influence of correction of acidosis on plasma level of branched-chain amino acids in chronic hemodialysis patients].

Seven patients undergoing chronic hemodialysis three times a week and whose plasma bicarbonate concentration on predialysis was consistently under 18 mmol/l due to bicarbonate dialysis (BCD), were treated with BCD for 2 weeks, then switched to acetate-free biofiltration (AFB) for 8 weeks. In both periods, the same high flux dialyzer (AN69HF) was used. The treatment time, dialysate flow rate and blood flow rate were kept constant in each patient during both periods. Plasma bicarbonate concentration (HCO3-), serum urea nitrogen (SUN), serum creatinine (Cr) and plasma amino acids concentrations (AA) were measured before dialysis and KT/V was calculated on the 2nd days of the last week in both periods. HCO3- on AFB was significantly higher than that on BCD (16.4 +/- 0.9 vs 19.9 +/- 1.8 mmol/l; p < 0.05). SUN on AFB was significantly lower than that on BCD even though the dialysis schedule and dietary content were not changed (84.7 +/- 3.7 vs 76.6 +/- 3.8 mg/dl; p < 0.05). TP, Cr and KT/V were not significantly different. Plasma total amino acid concentration (TAA) and plasma essential amino acid concentration (EAA) were not significantly different in both periods. In contrast, plasma branched-chain amino acid concentrations (BCAA) on AFB were significantly higher than that on BCD (313.5 +/- 44.3 vs 390.3 +/- 50.7 mumol/l; p < 0.05). Plasma BCAA concentrations, valine (VAL), leucine (LEU) and isoleucine (ILE), were significantly higher on AFB than that on BCD, respectively (p < 0.05). These findings suggest that optimal correction of the metabolic acidosis in chronic hemodialysis patients by AFB leads to a significant increase in plasma BCAA concentration.

Acidosis, Lactic↗
PubMed1998

[A consideration in the care of elderly patients receiving home hospice care: administration of parenteral nutrition at home].

Due to the recent increase in the elderly population in Japan, the number of elderly patients with gastric cancer has also increased. As a result, not only the need for care of these patients has increased but also the care system has become diverse. In our hospital, more than 30% of patients who received home hospice care were over 70 years old and home hospice care of elderly patients with terminal cancer has become an important activity of our hospital. Whether home parenteral nutrition (HPN) procedures should be administered in the home for these patients is controversial. Our hospital has decided to inform patients with malignant disease of their true diagnosis under the doctrine of informed consent. In 1997, 94.1% of patients above 70 years, of age were informed of the actual nature of their disease. As a result, they were allowed to make a choice regarding home hospice care. An 81-year-old patient with terminal gastric cancer chose home hospice care and successfully managed the treatment procedures, including the use of a pump for intravenous alimentation. Through this case, we report here an ideal model of home hospice care of elderly patients under the concept of informed consent.

Aged↗
PubMed1996

Analysis of mandible of newly developing strain of Japanese white rabbit (Nib:JWNS).

In the present paper, we applied analysis of the mandible to a new strain of Japanese White rabbit being developed (Nib: JWNS), at 5th and 8th generations (F5 and F8), and evaluated the process of establishment, making comparison with the parent colonies (I, K and L), and other established JW colonies (A, E, O and R). The mandibles were measured at 12 sites and the data obtained were calculated by principal component analysis and discriminant analysis. As a result of principal component analysis, the parent colonies were found to be close to one another with intermediate size of the mandible and height of condyloid and angular processes, but in F5 and F8 the mandibles were slightly shorter in height and different from those in the parent colonies. On the other hand, results of discriminant analysis revealed that mandibles were discriminated correctly 100% in colonies A, O and R, and 90% in E and I. Colonies A, O, R, E and I were therefore regarded as established strains. In the developing colonies, the discriminant rate was 70% in F5 and 80% in F8. One mandible from F5 and two from F8 were wrongly classified to the parent colony L, which was the lowest discriminant rate among the colonies examined (61.5%). The results of both statistical analyses suggest that the JWNS are almost established at 8th generation as a new strain.

Animals↗
PubMed1994

Effects of recombinant human erythropoietin (rHuEPO) on nutritional status of hemodialysis patients: investigation of direct anabolic effects of rHuEPO.

To investigate whether the nutritional improvement achieved by recombinant human erythropoietin (rHuEPO) treatment is the result of anemia correction with rHuEPO or the direct anabolic effects of rHuEPO per se, nutritional assessment was performed in 2 studies (study I and II) on hemodialysis (HD) patients. Nutritional assessment included blood biochemistry determinations, anthropometric measurements, daily protein intake (DPI) and dialysis efficiency. In study I, 5 HD patients who had not been given rHuEPO and had a hematocrit (Hct) of < or = 25%, were administered rHuEPO at the initial dose of 96.2 U/kgBW. Nutritional assessment of these patients was performed before rHuEPO treatment and every 4 weeks until the 24th week after rHuEPO treatment. In study II, the same nutritional assessment as in study I except for DPI, was performed in 2 groups with the same Hct level and dialysis regimen; an EPO group (n = 8) previously given rHuEPO (88.2 +/- 13.7 U/kgBW, 25.8 +/- 2.5 mos) and a non-EPO group (n = 8) not given rHuEPO. In study I, the mean Hct level was significantly increased 4 weeks after rHuEPO treatment (23.3 +/- 0.6 to 26.9 +/- 0.9%). However, the nutritional parameters and dialysis efficiency were nearly constant over 24 weeks, suggesting either the absence of a short-term direct anabolic effect of rHuEPO or masking of such an effect due to general condition improvement by anemia correction with rHuEPO. In study II, no significant differences in nutritional assessment were confirmed between the groups, suggesting that a long-term direct anabolic effect of rHuEPO may not exist and nutritional improvement may result from correction of anemia with rHuEPO.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1993

How long can continuous ambulatory peritoneal dialysis be continued?

We investigated how long continuous ambulatory peritoneal dialysis (CAPD) could be continued in the face of peritoneal sclerosis. 15 CAPD patients with no experience of peritonitis were selected and the time limitation for CAPD was examined retrospectively, based on the dialysate osmolality, serum creatinine concentration, etc.. The values for the dialysate osmolality and serum creatinine concentration increased gradually with the duration of CAPD and were significantly increased from 6 months. 5 patients whose serum creatinine concentration during the first 6 months after initiation of CAPD increased more than 5 mg/dl, could not continue CAPD for more than 24 months because of the appearance of peritoneal membrane failure. When the time limitation for CAPD was assessed in 10 stable patients, close relationships between the mean dialysate osmolality and duration of CAPD (Y = 0.52X + 351.25, r = 0.83, P < 0.01), and between the mean serum creatinine concentration and duration of CAPD (Y = 0.18X + 6.84, r = 0.95, P < 0.001) were recognized. If the practical limitation for CAPD was set at 400 mOsm/l in terms of the dialysate osmolality or 20 mg/dl in terms of serum creatinine concentration, its value became 94.1 months or 73.1 months, respectively. It is concluded that the time limitation for CAPD can be expected to be approximately 6 to 8 years in stable CAPD patients, and we need to resolve CAPD-induced problems involving the peritoneal membrane in order to continue CAPD for more than 10 years.

Adult↗
PubMed1993

Oral 1,25(OH)2D3 pulse therapy for the treatment of secondary hyperparathyroidism.

We examined the effect of oral 1,25(OH)2D3 pulse therapy in hemodialyzed patients with secondary hyperparthyroidism (2 degrees HPT). Prescription of 6.0 micrograms 1,25(OH)2D3 once a week combined with calcium carbonate as a phosphate binder during the last 5 days a week for 12 weeks resulted in improvement of mild to moderate 2 degrees HPT despite no significant differences in serum total calcium and phosphate concentration. In addition, the effect was greater in cases with mild 2 degrees HPT. A single administration of 6 micrograms 1,25(OH)2D3 reduced the parathyroid hormone concentration in patients with mild 2 degrees HPT or with a short duration of hemodialysis. Tmax of the serum 1,25(OH)2D3 after single administration of 6.0 micrograms 1,25(OH)2D3 was individually different (range, 0.4-20.9 hrs). It is recommended that early employment of oral 1,25(OH)2D3 pulse therapy be undertaken once a week combined with prescription of calcium salt as a phosphate binder during the last 5 days a week for the treatment of 2 degrees HPT refractory to conventional therapy, since there is no risk of aluminum accumulation with satisfactory control of the serum total calcium and phosphate concentration.

Administration, Oral↗
PubMed1993

A case complicated with SLE during maintenance hemodialysis.

A 40-year-old woman suffered from toxemia of pregnancy in 1977 and was admitted to hospital. Thereafter, she developed nephrotic syndrome, underwent a renal biopsy, and a diagnosis of membranoproliferative glomerulonephritis (MPGN) was made. She received steroid therapy, immunosuppressive drug and anticoagulant therapy, and recovered sufficiently to be discharged from hospital in April, 1979. During subsequent ambulatory treatment at our outpatient department, her renal function deteriorated gradually, and maintenance hemodialysis was started from June, 1990. In July, 1991, she was admitted to our hospital with pleurisy and pericarditis. There was no improvement despite antibiotic treatments. Laboratory data revealed leukopenia and lymphopenia. Under suspicion of systemic lupus erythematosus (SLE), relevant tests were carried out. Immunological abnormalities such as positive LE cells and the presence of various autoantibodies, together with clinical signs of hypersensitivity to sunlight, stomatitis and serositis, satisfied the diagnostic criteria of the ARA and a diagnosis of SLE was made. This case did not exhibit any clinical or serological abnormalities except for the renal disorder for a 10-year period after the histological diagnosis of MPGN, but was eventually diagnosed as SLE as a result of the manifestation of SLE symptoms for the first time after one year of maintenance hemodialysis. Immunological abnormalities and SLE during maintenance hemodialysis are discussed in relation to other reports.

Adult↗
PubMed1992

Early morphological changes of tubules in rats with chronic renal failure.

We investigated the early changes of tubules and effect of the oral adsorbent, AST-120, on the early changes of tubules in rats with chronic renal failure. Sprague-Dawley rats were divided into two groups with and without AST-120, after 3/4 nephrectomy. Although there were no significant differences in levels of blood urea nitrogen, serum creatinine, creatinine clearance, inulin clearance, para-aminohippuric acid clearance and urinary N-acetyl-beta-D-glucosaminidase at week 8 between the two groups, the amount of 24-hour urinary protein excretion and the direct systolic blood pressure at week 8 were significantly decreased in the group with AST-120. Examinations by light microscopy at week 8 revealed that proteinaceous casts in the tubules, tubular dilatation and infiltration of monocytes into the interstitium in the group with AST-120 were less prominent than those in the group without AST-120. A significant difference in numbers of proteinaceous casts was noted at week 8 between the two groups. In rats with chronic renal failure at the early stage, it is concluded that the formation of proteinaceous casts, resulting in tubular damage, is increased and that AST-120 delays the occurrence of proteinaceous casts by delaying the increase in urinary protein excretion.

Adsorption↗