Biomedical subjects

S Nakamoto

Publications and source records attributed to S Nakamoto.

At least 37 records · Page 2Linked to original sources

PubMed1997

Two-directional aortic annular enlargement for aortic valve replacement in the small aortic annulus.

We have encountered 3 patients with a small aortic annulus for whom the conventional posterior enlargement alone was not extensive enough to implant an artificial valve of acceptable size. Therefore, we performed two-directional enlargement, which is a combination of posterior and anterior enlargement. First, the posterior enlargement was done, and then an additional aortotomy was made anteriorly and extended to the ventricular septum. The aortic annulus was enlarged by 68% after the two-directional enlargement. At a follow-up of 31 months, the patients' functional status was New York Heart Association class I.

Adult↗

PubMed1997

Effects of aminoguanidine on serum advanced glycation endproducts, urinary albilmin excretion, mesangial expansion, and glomerular basement membrane thickening in Otsuka Long-Evans Tokushima fatty rats.

This study evaluated the effects of treatment with an inhibitor of advanced glycation endproducts, aminoguanidine, on the development of albuminuria, mesangial expansion and glomerular basement membrane (GBM) thickening in Otsuka Long-Evans Tokushima Fatty (OLETF) rats, which we found to be an excellent model of non insulin-dependent diabetes mellitus (NIDDM), for its very close similarity to human NIDDM. OLETF rats were randomized into a non-treatment diabetic group (D-group, n = 5) and an aminoguanidine-treated group (AG-group, n = 5). The AG-group was given 100 mg/dl aminoguanidine HCl in free drinking water. Treatment was started at 16 weeks of age. We measured body weight, plasma glucose, total cholesterol, triglycerides and the urinary albumin excretion (UAE) rate before and after treatment at regular intervals. At 56 weeks of age, we measured serum advanced glycation endproducts (AGE), mesangial expansion and glomerular basement membrane. There were no significant differences in pre-treatment body weight, plasma glucose and UAE between the D-group and the AG-group. Likewise, after treatment there were no significant differences in body weight, plasma glucose, total cholesterol, triglycerides and immunoreactive insulin. Significant differences were, however, noted in serum AGE (63.2 +/- 3.5 and 51.8 +/- 3.0 U AGE/ml, P < 0.05), UAE (203.6 +/- 37.7 and 89.8 +/- 18.6 mg/day, P < 0.05), fractional mesangial volume (21.3 +/- 1.7 and 16.7 +/- 0.8%, P < 0.05) and GBM thickness (453 +/- 17 and 366 +/- 50 nm, P < 0.05) between the D-group and the AG-group. Our results suggest that aminoguanidine inhibits the AGE formation and the development of diabetic nephropathy in OLETF rats.

Albuminuria↗

PubMed1997

Effect of allergen immunotherapy on nasal responses in guinea-pigs with allergic rhinitis.

METHODS: We have investigated the effects of allergen immunotherapy on the nasal responses in the guinea-pigs with allergic rhinitis. Thirty-three male Hartley guinea-pigs with allergic rhinitis were divided into three groups; those receiving intradermal injection of saline (Group 1) or 0.1% ovalbumin (Group 2) 6 days after the last intranasal sensitization, and those injected with 0.1% ovalbumin intradermally once daily for 6 consecutive days from the next day after the last intranasal sensitization (Group 3). RESULTS: The dye leakage and histamine content into the nasal lavage significantly decreased at 30 min after antigen challenge in Group 3, compared with Group 1 or 2. We also observed the change of mast cell numbers in superficial nasal mucosa, lamina propria and injected dorsal skin. The number of mast cells in superficial nasal mucosa significantly decreased in Group 3 compared with Group 1 or 2, but not those in nasal lamina propria or dorsal skin. CONCLUSIONS: These results suggest that the improvements of nasal responses such as dye leakage and histamine content may be caused by the decrease of mast cell numbers in the superficial mucosal layer after the specific immunotherapy, which may be developing tolerance and one of the mechanisms underlying the beneficial effect of immunotherapy.

Administration, Intranasal↗

PubMed1997

Single lead atrial synchronous ventricular pacing in Japanese patients with complete atrioventricular block.

The purpose of this study was to review our experience with atrial synchronous ventricular pacing devices (THERA VDD pacing systems, Medtronic, Inc., U.S.A.) using single atrioventricular leads in Japanese patients with complete atrioventricular block and normal sinus function. Twenty patients with a mean age of 55 +/- 13 years underwent implantation of VDD pacemakers. At implantation the amplitude of atrial signals in the supine position during normal breathing, which was measured directly using an external pacing system analyzer, ranged from 1.8 to 5.8 mV with a mean amplitude of 3.4 +/- 1.4 mV. Atrial amplitudes did not change during deep breathing (3.3 +/- 1.1 mV) or in the semi-Fowler position (3.4 +/- 1.6 mV). Atrial oversensing or undersensing was not observed in any of the patients. During a follow-up period, the percentage of atrial synchronization was >95% in 19 patients, and none of the patients had pacemaker related tachycardia or pacemaker related complications. These results were promising enough to warrant the extension of the clinical use of the VDD pacemaker.

Adult↗

PubMed1997

[Intracranial hypertension in a patient with acute promyelocytic leukemia treated with all-trans retinoic acid].

A 21-year-old Japanese woman was referred to our hospital because of severe anemia and thrombocytopenia. Bone marrow aspiration showed a hypercellular marrow with 91.5% promyelocytes. Cytochemical study and surface marker a diagnosis of acute promyelocytic leukemia. Because leukocyte count elevated, she was treated with all-trans retinoic acid (ATRA) after conventional chemotherapy. After 11 days of ATRA therapy, the patient started to develop severe headache, nausea and diplopia. Ophthalmologic examination revealed bilateral papilledema. Computed tomography and magnetic resonance imaging of the head showed no intracranial lesion. ATRA was discontinued because it was suspected to cause intracranial hypertension. Her symptoms were relieved and patilledema improved gradually. ATRA is safe and well-tolerated, if the retinoic acid syndrome can be prevented or managed. As the tolerable dose of ATRA in adults is higher than that in children, the side effects tend to occur in children. In Japan, only two childhood cases of intracranial hypertension during ATRA therapy have been reported. We must remember the possibility of intracranial hypertension during ATRA therapy, even in adults.

Adult↗

PubMed1997

Effect of Krestin as adjuvant treatment following radical radiotherapy in non-small cell lung cancer patients.

To evaluate the efficacy of Krestin (PSK) as adjuvant treatment after radical radiation therapy (RT) for non-small cell lung cancer (NSCLC), treatment results of 225 patients with NSCLC treated with RT followed by adjuvant administration of PSK between 1976 and 1989 were analyzed. Of these patients, 170 (76%) had squamous cell carcinoma. In the patients with squamous cell carcinoma of the lung, PSK was given only when the tumor showed satisfactory shrinkage (complete or partial response) after completion of RT. The treatment outcomes were compared with those of the responders to RT not receiving PSK. The 5-year survival rates of patients with stages I-II and stage III disease were 39 and 26%, respectively, while the non-administered responder group's were 17 and 8%. These differences are statistically significant. An improvement in the treatment results with combined use of appropriate immuno-modulating drugs is anticipated in the future. When clinical trials of the efficacy of these drugs are conducted, the agents should be given to the patients with satisfactory tumor regression after RT, although they still take much time and cost.

Adjuvants, Immunologic↗

PubMed1996

An interaction of cisplatin and radiation in two rat yolk sac tumour cell lines with different radiosensitivities in vitro.

We investigated the interaction of cisplatin and radiation in two rat yolk sac tumour cell lines with different radiosensitivities in vitro. The effects were assessed by clonogenic assay. D0 for the radiosensitivity of the radioresistant variant cell line, NMT-1R was 139 cGy, which was 1.3 times larger than that for the parent radiosensitive cell line, NMT-1 (D0 = 107 cGy). The concentration of cisplatin required to reduce colony formation by 50% at 1 h treatment (ID50 of cisplatin) was 0.25 microgram/ml for NMT-1, whereas that for NMT-1R was 1.0 microgram/ml. Cisplatin potentiation of radiation sensitivity was manifested by the decrease in the slope of the radiation dose-response curve. D0's for NMT-1 and NMT-1R were 83 and 100 cGy in combined treatment with ID50 of cisplatin immediately before radiation. The enhancement ratios of cisplatin were therefore 1.30 for NMT-1 and 1.39 for NMT-1R respectively in D0. No different enhancement ratio for cisplatin was observed in the time course of combination treatment with cisplatin and radiation within the interval of 6 h. There was no clear change in cell cycle distribution within 6 h after treatment with ID50 of cisplatin for both cell lines. In conclusion, cisplatin had a synergistic effect on both cell lines which was independent of the time course and sequence in combination with radiation within 6 h.

Animals↗

PubMed1996

Hyperglycemia decreases dehydroepiandrosterone in Japanese male with impaired glucose tolerance and low insulin response.

Recent studies indicate that experimentally induced hyperinsulinemia may reduce serum dehydroepiandrosterone (DHEA) and dehydroepiandrosterone-sulfate (DHEA-S). Serum DHEA and DHEA-S decrease in diabetic patients, but the mechanism by which hyperglycemia decreases DHEA and DHEA-S is unknown. In this study, we investigated the effect of hyperglycemia on DHEA and DHEA-S in impaired glucose tolerance (IGT) by means of the 75g-oral glucose tolerance test (OGTT). We selected 30 male IGT patients receiving diet therapy only, whose insulinogenic Index was under 0.3. Oral glucose challenge significantly reduced DHEA (P = 0.0001) and DHEA-S (P < 0.05) at 60 and 120 min after OGTT. Setting the value of DHEA and DHEA-S at time zero as 100%, we calculated the DHEA and DHEA-S values at 60 and 120 min after OGTT as %DHEA(-S) 60 min and %DHEA(-S) 120 min, respectively. DHEA and DHEA-S at time zero showed no correlation with BMI, HbA1c, the sum of insulin values (sigma IRI) or the area under the curve of plasma glucose (AUC). We found decreases in %DHEA 60 min (r = -0.411, P < 0.05), %DHEA-S 60 min (r = -0.508, P < 0.01) and %DHEA-S 120 min (r = -0.393, P < 0.05) as AUC increased, but sigma IRI showed no correlation with %DHEA(-S) 60 min or %DHEA(-S)120 min. We conclude that the depression of DHEA and DHEA-S after OGTT is attributable to hyperglycemia in male Japanese IGT with low insulin response.

Dehydroepiandrosterone↗

PubMed1996

Depression of dehydroepiandrosterone in Japanese diabetic men--comparison between non-insulin-dependent diabetes mellitus and impaired glucose tolerance.

Hyperglycemia is known to reduce dehydroepiandrosterone (DHEA) circulating levels; however, the mechanism by which hyperglycemia decreases DHEA is not elucidated. In this study, serum DHEA and DHEA sulfate (DHEA-S) levels were compared in 50 men with non-insulin-dependent diabetes mellitus (NIDDM) and 50 age-matched men with impaired glucose tolerance (IGT) receiving only diet therapy. Serum concentrations of DHEA and DHEA-S in the NIDDM group were significantly lower than in the IGT group (7.8 and 9.7 nmol/l vs 3.4 and 4.9 mumol/l, respectively; p < 0.01) but there was no significant difference in immunoreactive insulin between the two groups. When the results from both groups were combined, HbA1C was significantly inversely related to DHEA (r = -0.243, p < 0.01) and DHEA-S (r = -0.305, p < 0.01). Immunoreactive insulin showed no correlation with DHEA and DHEA-S. Multiple regression analysis showed that HbA1C was independently negatively related to both DHEA and DHEA-S. We conclude that hyperglycemia may decrease serum DHEA and DHEA-S in Japanese men with NIDDM, but the depression of DHEA(-S) is independent of serum insulin level.

Dehydroepiandrosterone↗

PubMed1996

McArdle's disease with non-insulin-dependent diabetes mellitus: the beneficial effects of hyperglycemia and hyperinsulinemia for exercise intolerance.

A 64-year-old female with McArdle's disease and non-insulin-dependent diabetes mellitus (NIDDM) is reported. She had none of the characteristic symptoms of McArdle's disease such as muscle cramps but her serum creatine kinase level was elevated. Muscle biopsy with negative muscle phosphorylase staining showed McArdle's disease. Modified forearm ischemic exercise test was done at two conditions; fasting and two hours after a meal. When fasting, the level of lactic acid did not elevate after exercise. After a meal, however, the serum lactic acid level rose with the elevation of plasma glucose and IRI. Thus, we suggested that high plasma glucose and insulin due to NIDDM may induce blood-borne glucose uptake with exercise.

Biopsy↗

PubMed1996

Aggressive non-Hodgkin's lymphoma with massive involvement of the right ventricle.

A 69-year-old women with malignant lymphoma (diffuse large:Working formulation) had associated with intracavital involvement of the right ventricle. The patient was referred to us for further examination with a diagnosis of heart failure. A tumor mass was detected by magnetic resonance imaging in the right ventricular outflow tract. While in the hospital the patient experienced cardiogenic shock due to neoplastic pulmonary embolism. The tumor was surgically resected and the patient was then treated with systemic chemotherapy. She went into complete remission and has continued in this state for six months. This case demonstrates that early diagnosis and intensive chemotherapy contribute to a good prognosis of patients with malignant lymphoma associated with massive involvement of a cardiac chamber. A review of the Japanese literature is presented.

Aged↗

PubMed1995

The fate of renal allografts functioning for a minimum of 20 years (level 5A)--indefinite success or beginning of the end? A proposed classification of long-term allograft survivals.

Fifty-five renal allografts (44 from living-related and 11 from cadaver donors) that have functioned for at least 20 years (mean 22.9 +/- 2.3, range 20.1 to 30.7 years) were evaluated in three groups based on renal function: group I (n = 26), with a GFR of > or = 60 ml/min/1.73 m2 or serum creatinine < or = 1.4 mg/dl and no proteinuria; group II (n = 9), with a GFR of > or = 60 ml/min/1.73 m2 or serum creatinine < or = 1.4 mg/dl but > 150 mg proteinuria/24 hr; and group III (n = 20), with a GFR < 60 ml/min/1.73 m2 and/or serum creatinine > 1.4 mg/dL with or without proteinuria. Allograft factors, including acute rejection (AR) in 62% (34/55) and delayed function (DF) in 55% (6/11) of the cadaver grafts, did not preclude 20-year success and the prospect of continued survival since they were not significantly more frequent in group I, II, or III. However, AR was confined to a limited period within the first three months posttransplant in 18/18 recipients in groups I and II but only in 7/16 of group III (P = 0.0002). In groups I and II AR was treated with IVMP in 14/18 cases and only 6/16 in group III (P = 0.035). Donor age < or = 50 years and recipient age < or = 40 years each occurred in 87% (48/55) of these transplants. One- or two-HLA haplotype matching was present in 98% (43/44) of living related transplants. Major risks to the recipient were coronary artery disease (11 cases and 3 deaths), malignancy (18 cases and 1 death), and severe infection and hepatitis (35 cases and 3 deaths, 2 of whom also had coronary artery disease). Hypertension occurred in 25 recipients and diabetes mellitus in 12. Potential open-end success was compromised by renal dysfunction in groups II and III, but appeared possible in 12 of the 26 patients in group I. There is no apparent "safe-haven" point of time for immunosuppressed renal allograft recipients, who remain at increased risk for eventual renal allograft dysfunction, as well as cardiovascular, neoplastic, infectious, and metabolic diseases. In order to clarify and standardize the words "long-term," a simple classification of long-term allograft survivals is proposed.

Adolescent↗

PubMed1995

Retrospective analysis of hemodialyzed diabetic patients in Japan.

We retrospectively analyzed the courses of 37 non-insulin dependent diabetics (hemodialyzed:HD group) with end-stage renal disease (ESRD), to identify factors predisposing to renal failure. The factors analyzed were: diabetic (non-proliferative and proliferative) retinopathy, family histories of diabetes and hypertension, smoking, dyslipidemia, first examination proteinuria and non-compliance. These factors were statistically compared in 37 NIDDM without renal failure (non-HD group). There were no significant differences in age or duration of diabetes between the two groups. Significant differences (P < 0.001) were, however, recognized in diabetic proliferative retinopathy and hypertension between the two groups. Hypertension was present in 35/36 (97.2%) HD patients and in 21/36 (58.3%) non-HD patients. A family history of hypertension was recognized in 16/37 HD (43.2%) and in 7/33 (21.2%) non-HD (P < 0.05). Differences were recognized in HDL-cholesterol, LDL-cholesterol and TG levels (38.2 +/- 12.5 mg/dl and 56.7 +/- 18.5 mg/dl, 140.4 +/- 57.1 mg/dl and 115.6 +/- 33.6 mg/dl, 169.9 +/- 89.4 mg/dl and 115.7 +/- 75.1 mg/dl, in HD and non-HD, respectively, P < 0.05). First visit proteinuria was found in all HD patients, and in 6/34 (17.6%) non-HD. The difference in previous treatment refusal, for 7 or more years, was significant with 23/36 (58.9%) HD patients and only 1/25 (4.0%) non-HD patients (P < 0.001) having a history of prolonged non-compliance with diabetic treatment. Diabetic retinopathy, non-proliferative and proliferative, hypertension and a family history of hypertension, elevated triglyceride and LDL-cholesterol, low HDL-cholesterol, first visit proteinuria, and prolonged non-compliance correlated with progression to ESRD. We advocate expanding diabetic education to include prevention of complications such as diabetic nephropathy.

Aged↗

PubMed1995

Isolation and biological activity of thielocins: novel phospholipase A2 inhibitors produced by Thielavia terricola RF-143.

Thielocins A2 alpha, A2 beta, A3, B1, B2 and B3 were isolated as a novel family of phospholipase A2 inhibitors from the fermentation broth of Thielavia terricola RF-143 together with thielavins and thielocins A1 alpha and A1 beta. The most potent inhibitory activity (IC50 = 0.0033 microM) against rat group II phospholipase A2 was shown by thielocin A1 beta. Against human group II phospholipase A2, thielocin B3 (IC50 = 0.076 microM) was the most potent.

Animals↗

PubMed1995

Prognostic factors for loco-regional control and outcome of re-irradiation for patients with poorly-differentiated squamous cell carcinoma of the nasopharynx.

Retrospective analysis was performed to evaluate the prognostic factors for loco-regional control and the results of re-irradiation for 28 patients with recurrent, poorly-differentiated squamous cell carcinoma (PDSCC) of the nasopharynx. Twenty-four of them received re-irradiation. Local, local plus regional and regional recurrences were observed in 19, five and four patients, respectively. Except for three patients, all had Stage IV disease at the initial diagnosis. The only parameters influencing loco-regional recurrence were T and N stage categories. The median latent period from initial treatment to recurrence was 18.5 (range, 2-100) months. There was no difference in latent period by first recurrence site, although recurrent tumors confined to the nasopharynx or those only regionally developed had a longer latent period. Only four patients developed secondary distant bone metastases with a median latency of three months from loco-regional relapse. The patients with local recurrent tumors confined to the nasopharynx, and those with regional recurrences only, could be salvaged by re-irradiation, with five-year survival rates of 44 and 100%, respectively. Five of 28 patients (18%) developed severe chronic radiation sequelae: cerebrospinal complications in four patients, bilateral neck fibrosis in one. We conclude that recurrent PDSCC of the nasopharynx can be controlled by re-irradiation with some success. Radiation therapy techniques must, however, be carefully planned in order to avoid the severe late post re-irradiation sequelae. For patients with advanced non-curable local recurrences, palliative care should be recommended instead of agressive re-irradiation.

Carcinoma, Squamous Cell↗

PubMed1994

[The evaluation of hyposensitization with house dust in patients with nasal allergy to house dust-mite].

We evaluated the clinical and pathophysiological efficacy of hyposensitization with house dust extracts to perennial nasal allergy. Fifty-one patients with allergic perennial rhinitis completed 5 months to 15 years with a mean of 2.4 years course of hyposensitization treatment with house dust extracts, and analyzed clinical symptoms, nasal provocation testing, nasal hypersensitivity to histamine, mast cells and eosinophils in nasal scraping, specific IgG and IgG4 antibody in serum, and blood eosinophils and basophils in relation to therapeutic duration. The improvement in nasal symptoms was found in 74.1% in adults and 66.7% in child and the continuation of hyposensitization with house dust extracts for a half to one year showed significant improvement of clinical symptoms. In objective examination, nasal provocation testing, nasal hypersensitivity to histamine, the number of mast cells and eosinophils in nasal scraping, and blood basophils showed significant improvement at 6 to 12 months the same as clinical symptoms. These findings suggest that the continuation of hyposensitization with house dust extracts is recommendable as a basic treatment against perennial nasal allergy.

Adolescent↗

PubMed1993

Mitogenic activity and lethal toxicity of lipid A analogs, glucosamine-phosphate carrying aromatic alkyl groups, in mice.

The mitogenicity and lethal toxicity of four synthetic lipid A analogs, glucosamine-4-phosphate with a 7-hydroxy-heptanoyl group (A-166), with a 7-phenyl-heptanoyl group (A-167), or with a 8-(1-phenyl-hexanoyl)-nonanoyl group (A-168), at the C-2 and C-3 positions, and glucosamine-6-phosphate with the same substituents as A-168 at C-2 and C-3 (A-169), were compared. The compound A-166 exhibited no mitogenic activity at various concentrations ranging from 3.13 to 50 micrograms/ml in the splenocytes of BALB/c mice, but A-167 exhibited weak mitogenic activity at concentrations of 12.5 and 25 micrograms/ml. A-168 and A-169, as well as A-103, glucosamine-4-phosphate carrying (R)-3-tetradecanoyl-oxytetradecanoyl groups, have remarkable mitogenic activity at concentrations ranging from 12.5 to 100 micrograms/ml; the activity of A-169 (6-phosphate) was stronger than that of A-168 (4-phosphate). Compound A-167 failed to cause death at doses of 25 and 50 micrograms/mouse in galactosamine-loaded C57BL/6 mice while A-166 and A-169 were toxic to 2 out of 6 mice at 50 micrograms/mouse; no deaths were observed at 25 micrograms/mouse. A-168 showed the highest toxicity of any of the compounds tested at 25 and 50 micrograms/mouse. The lethal effect of A-103 appeared to be somewhere between that of A-168 and A-169. These findings indicate that lipid A analogs, carrying an aromatic alkyl group as well as a hydroxyacyl group, are mitogenic and lethal when given to mice.

Animals↗

PubMed1993

Animal pharmacokinetics of FK037, a novel parenteral broad-spectrum cephalosporin.

Single-dose pharmacokinetics of FK037 has been investigated in laboratory animals. After bolus intravenous dosing with 20 mg/kg, the elimination half-life of FK037 varied in the species; with values of 0.27, 0.30, 0.97, 1.29 and 1.76 hours in mice, rats, rabbits, dogs and monkeys, respectively. The volume of distribution ranged between 260 ml/kg in rats and 390 ml/kg in dogs. These parameters approximated those of ceftazidime and cefpirome used as reference drugs. The renal clearance of FK037 was almost equal to glomerular filtration rate (GFR) in rabbits. Probenecid did not affect the elimination half-life of FK037 and its clearance ratio to GFR. These findings suggest that FK037 is solely excreted by glomerular filtration. FK037 readily penetrated into the tissues and inflammatory exudate fluid in rats, and the tissue level was highest in the kidneys, and decreased in the following order; lungs > heart > liver > spleen. Penetration of FK037, cefpirome and ceftazidime into the cerebrospinal fluid were determined using induced staphylococcal meningitis in rabbits. The penetration percentage ranged from 14.2 to 16.0% for these drugs with no significant differences. The major route of excretion of FK037 was via the kidney, with more than 74% of the dose being excreted in the urine within 24 hours after dosing to each species. Biliary excretion was low, 0.79% in rats. Bioautograms showed only unchanged drug in the plasma, urine and bile. Serum protein binding was low (8.8 to 17.6%) in all the species studied.

Animals↗