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Biomedical subjects

S Kamata

Publications and source records attributed to S Kamata.

At least 145 records · Page 8Linked to original sources
PubMed1992

A novel class of platelet activating factor (PAF) antagonists. II. Modification of the 2-position of the glycerol backbone of PAF-sulfonamide isosteres.

In a continuing effort to obtain more potent platelet activating factor (PAF) antagonists, we tried to synthesize a series of PAF-sulfonamide isosteres in which the substituent at the 2-position was modified to an acetoxy equivalent other than the methoxy group. These modifications produced highly active PAF antagonists. Compound 3-[2-(5-methyl-2H-tetrazol-2-yl)-3-(octadecylcarbamoyloxy) propylaminosulfonyl]propylquinolinium iodide (52) showed the most potent activity in the in vitro inhibitory effect on PAF-induced platelet aggregation in rabbit platelet-rich plasma (IC50 = 125 nM) and also in the in vivo protective effect on PAF-induced lethality in mice, with prolonged duration of action. Optically active enantiomers of this compound were synthesized and the (S)-(-)-isomer (IC50 = 87 nM) was found to be three times more potent that the (R)-(+)-isomer (IC50 = 289 nM), clearly exemplifying the enantioselectivity in the PAF-antagonist action of this novel compound.

Animals↗
PubMed1992

[A retrospective analysis of surgical operations on malignancies of the ear].

In the past 20 years from 1970 to 1990, 21 patients with malignancies of the ear were treated at Cancer Institute Hospital. The primary sites were the auricle and cartilaginous external auditory canal (group 1: n = 8), the bony external auditory canal (group 2: n = 6) and the middle ear (group 3:n = 7). In group 1, pathological types were squamous cell carcinoma in four patients and basal cell carcinoma in the other four patients. Seven patients were treated by surgery alone, and the remaining patient was treated by interstitial implant radiotherapy. No recurrence have been noted up to today in this group. In group 2, pathological types were squamous cell carcinoma in four patients and adenoid cystic carcinoma in the other two patients. All of the six patients underwent external canal resection or subtotal temporal resection. Two patients received postoperative radiotherapy. A five year survival rate of group 2 was 60%. In group 3, pathological types were squamous cell carcinoma in six patients and undifferentiated carcinoma in the remaining patient. Most of them underwent radical mastoidectomy followed by irradiation. However, all the patients died within two years after treatment. In group 2 and 3, cytodiagnosis was useful for early discovery. In group 2, temporomandibular joint seemed to be a key point in surgical treatment. In group 3, the combination of conservative surgery with radiotherapy was not a radical treatment. This suggested it necessary to perform subtotal temporal resection to treat malignancy of the middle ear.

Adult↗
PubMed1992

The effect of phlebotomy on serum erythropoietin levels in normal healthy subjects.

We evaluated endogenous serum erythropoietin (Epo) levels in 14 normal subjects (eight males and six females) after a single 400-ml phlebotomy. The subjects were followed up for 56 days. The hemoglobin (Hb) values of both males and females decreased to a nadir on days 3 to 7 post-phlebotomy. Hb values gradually increased, but did not completely recover to pre-phlebotomy levels by day 56. Serum Epo levels increased after 6 h post-phlebotomy, to 20.1 +/- 5.4 (mU/ml) in males and 20.7 +/- 7.0 in females, from the pre-phlebotomy levels of 14.6 +/- 4.0 in males and 13.4 +/- 4.1 in females, respectively. Epo levels continued to increase to peak levels of 25.5 +/- 6.3 in males and 28.7 +/- 11.5 in females on days 7 to 14 and thereafter decreased until day 56. Thus, the Epo response to a 400-ml phlebotomy was relatively small in magnitude and was not sufficient to initiate a significant increase in erythropoiesis. This finding suggests that the administration of recombinant human erythropoietin (rHu-Epo) may be effective for the prompt correction of anemia induced by autologous blood donation and for increasing the volume of predonated autologous blood.

Adult↗
PubMed1992

[Pseudocoarctation associated with dissecting aneurysm of the aorta: a case report].

A case of pseudocoarctation with dissecting aneurysm of the ascending aorta and arch is reported. A 49-year-old man was admitted with chest pain and loss of consciousness. Angiogram showed kinking of the aortic isthmus and dissecting aneurysm of the ascending aorta. There was no pressure gradient between arms and legs. Prosthetic graft replacement of the ascending aorta was successfully performed by the use of total cardiopulmonary bypass with moderate hypothermia. Etiology of the development of pseudocoarctation is unknown, however, hypothesis that embryological abnormality of the aortic arch is one of the contributing factors has been widely accepted. This case was accompanied by bicuspid aortic valve. It is suggested that the developmental etiology of this case seems to be similar to that of classical coarctation of the aorta. Development of the dissecting aneurysm is supposed to be due to hypertension of the upper body during exercise, even though there is no pressure gradient at rest.

Aortic Dissection↗
PubMed1992

[A case of emphysematous pyelonephritis with disseminated intravascular coagulation].

A case of emphysematous pyelonephritis with disseminated intravascular coagulation (DIC) is presented. A 54-year-old woman was admitted to our hospital because of unclear consciousness and extremely high blood glucose level. The laboratory data suggested uncontrolled diabetes mellitus (DM) and urinary tract infection with sepsis and DIC. The plain abdominal X-P and abdominal CT revealed the existence of gas in the right renal parenchyma, perinephric tissue and the upper part of the right ureter. Right nephrectomy was performed after the improvement of the patient's condition by the echo-guided drainage of the right kidney and the treatment for infection, DM and DIC. We reviewed 71 cases of emphysematous pyelonephritis in the Japanese literature and the choice of treatment was discussed.

Disseminated Intravascular Coagulation↗
PubMed1992

Roux-en-Y versus interposition biliary reconstruction.

We compared two types of biliary reconstruction for congenital dilatation of the bile duct--Roux-en-Y hepaticojejunostomy and jejunal interposition hepaticoduodenostomy after removal of the dilated bile duct. There were no significant differences in the occurrence of early and late complications except for the repeated attacks of abdominal pain that occurred only in the group that underwent jejunal interposition hepaticoduodenostomy. The results of further examinations for the presence of bile reflux with 99mTc-pyridoxyl methyl tryptophan scintigraphy and gastroscopy in this group revealed a high incidence of chronic gastritis associated with bile reflux. This report is the first to demonstrate the occurrence of bile reflux gastritis in patients who underwent jejunal interposition hepaticoduodenostomy, which is theoretically a more logical approach than the other method of bile reconstruction. Further studies, with respect to possible mechanisms, as well as careful and longer follow-up evaluation, are required.

Adolescent↗
PubMed1991

4'-galactooligosaccharide affects sodium and potassium metabolism in rats.

The effect of different levels (0, 10 and 20%) of O-beta-D-galactopyranosyl-(1-4)-O-beta-D-galactopyranosyl-(1-4)-D- glucose (4'-GL) on the bioavailability of sodium and potassium was studied in 18 male rats. Three 3-d metabolic balance studies were conducted during the 62-d feeding trial. These were between d 30 and 32 (first period), 45 and 47 (second period) and 60 and 62 (third period). Growth and food intake were not significantly different (P less than 0.05) between the control group and the 4'-GL-fed groups. In rats fed 10 and 20% 4'-GL diet, the fecal sodium excretion was significantly greater (P less than 0.05) in all three balance periods. Fecal potassium excretion was significantly greater (P less than 0.05) in the 10% 4'-GL-fed group in the second balance period and the 20% 4'-GL-fed group in all balance periods relative to the control group. Although not statistically significant, rats in the 4'-GL-fed groups exhibited a tendency for lower sodium retention and higher potassium retention compared with the control group. The cecal weight of rats in both 4'-GL-fed groups was significantly heavier (P less than 0.05) than that of the control group at the end of study. Sodium concentration in the cecum was significantly lower (P less than 0.05) in the 20% 4'-GL-fed group relative to the other groups.

Animals↗
PubMed1991

The correlation of skin blood flow with age, total cholesterol, hematocrit, blood pressure, and hemoglobin.

Normal skin blood flow at the deltoid region in 55 men whose ages ranged from 20 to 72 years was measured by the xenon-133 clearance method. In addition, the correlation of skin blood flow with age, systolic blood pressure, total cholesterol, hematocrit, hemoglobin, and total protein was analyzed by multiple regression analysis. The following results were obtained. Normal skin blood flow was found to decrease with increase in age, total cholesterol, and systolic blood pressure and showed a tendency to increase with elevation in hematocrit and hemoglobin values. Of the six parameters examined in the present study, the parameter that showed the strongest correlation with skin blood flow at the deltoid region was age, followed in decreasing order by total cholesterol, hematocrit, systolic blood pressure, and hemoglobin. It could therefore be concluded that age is the most reliable factor in clinically estimating skin blood flow. Furthermore, inasmuch as total cholesterol, hematocrit, systolic blood pressure and hemoglobin values also were correlated with skin blood flow, these values also should be taken in account in the synthetic evaluation of skin blood flow. It was skin blood flow at the deltoid region that was strongly correlated with age. This was followed by systolic blood pressure, hematocrit, and hemoglobin. Total cholesterol showed a weak correlation with age, but total protein did not demonstrate any correlation with skin blood flow and age. The results of the present study show that skin blood flow would be poor in the elderly and in patients with arteriosclerosis, hypertension, and anemia. Since it is suggested that the wound-healing process is delayed in such patients, utmost care should be exercised in treating their wounds.

Adult↗
PubMed1991

[The effect of cellulose and glucomannan on the absorption of lead in rats].

The effect of two different fibers on lead (Pb) absorption was investigated during two 3-day balance-study periods (day 15th to 17th and 30th to 32nd) of a 32-day feeding course in young rats. Young rats were fed for 32 days diets containing Pb (200 mg/kg diet), with or without the addition of 10% cellulose or glucomannan. The following results were obtained: 1) The total fecal Pb content was significantly increased (p less than 0.05) in the Pb + cellulose group than in the Pb alone group during both balance-study periods. However, there was no significant difference between the Pb alone group and the Pb + glucomannan group. 2) Lead retention was significantly lower (p less than 0.05) in the Pb + cellulose group than in the Pb alone group during both balance-study periods. However, there was no significant difference observed between the Pb alone group and the Pb + glucomannan group. 3) Rats fed on the Pb + glucomannan diet had a significantly heavier (p less than 0.05) cecum and large intestine than rats fed on the other two diets. 4) The concentration of Pb in the cecum was significantly lower (p less than 0.05) in the Pb + cellulose group than in the other two groups. These results indicate that cellulose supplementation reduced the retention of Pb, while glucomannan supplementation had no significant effect on the retention of Pb.

Absorption↗
PubMed1991

[Effects of sodium chloride on destruction of microorganisms by microwave heating in potatoes].

To assess the destructive effect of different sodium chloride concentrations (0, 0.3, 1.5, and 3%) on microorganisms with microwave heating, strains of Vibrio parahaemolyticus, Staphylococcus aureus, Salmonella enteritidis, Escherichia coli and Bacillus cereus were used to inoculate a mashed potato preparation. After microwave heating for 1 min at 800 W, resulted in temperatures and rate of destruction of bacteria significantly higher (p less than 0.05) in the core than on the surface of mashed potato when no salt was added. Except for B. cereus, microorganisms inoculated into mashed potato, with no added salt, could be completely destroyed by 2 min of microwave heating. Core temperatures and rate of destruction of microorganisms in the mashed potato decreased significantly (p less than 0.05) with increase in concentration of added salt. The results also indicate that bacterial species differ in their susceptibility to microwave inactivation. In particular, S. aureus, which exhibited a level of survival that was greater than that of any other species tested here, seemed notably resistant to microwave treatment for 2 min while V. parahaemolyticus was highly susceptible.

Bacteria↗
PubMed1991

Blood ketone bodies in NIDDM: relationship with diabetic control and endogenous insulin secretion.

To evaluate the relationship of blood ketone bodies with diabetic control and endogenous insulin secretion, fasting plasma glucose (FPG), hemoglobin A1c (HbA1c), fasting serum C-peptide (CPR), blood total ketone-bodies (TKB), blood acetoacetate (AcAc) and blood 3-hydroxybutyrate (3-OHB) were compared in 78 outpatients with non-insulin-dependent diabetes mellitus (NIDDM) treated with diet (n = 13), sulfonylurea (n = 52) and insulin (n = 13). TKB, AcAc and 3-OHB in patients treated with insulin were significantly higher than in patients treated with diet or sulfonylurea. In patients given diet therapy, log 3-OHB showed significant negative correlations with FPG, HbA1c and CPR. In patients treated with sulfonylurea, log 3-OHB showed significant positive correlations with FPG and HbA1c, but not with CPR. In patients treated with insulin, there were no correlations of log 3-OHB with FPG, HbA1c and CPR. For evaluation of the metabolic state in diabetes mellitus, measurement of blood ketone bodies is useful, and moreover necessary, in addition to diabetic control or determination of the endogenous insulin level.

3-Hydroxybutyric Acid↗
PubMed1991

[Subarachnoid hemorrhage following commencement of danazol treatment in a patient well controlled on warfarin anticoagulation].

A 45-year-old woman with prosthetic valves replacement, was admitted with severe headache and vomiting one month after starting danazol treatment at 300 mg per day. She was receiving long-term anticoagulation with warfarin and dipyridamole, taking 3.5 mg and 300 mg per day respectively. The patient's thrombotest value was less than 6% at the time of admission. Cranial CT revealed subarachnoid hemorrhage. Warfarin and danazol treatment ware discontinued with replenishment of vitamin K. Recovery was uneventful. Danazol is 2, 3 isoxazol derivative of 17-alpha-ethinyl testosterone. As such, it shares the property of C 17 alkylated steroids in potentiating the action of coumarin. It is suggested that danazol affects the turnover of vitamin-K-dependent clotting factors, an impairment of synthesis being a likely mechanism. The possible hazard of the potentiating effect of danazol on warfarin should be widely appreciated.

Aortic Valve Insufficiency↗
PubMed1990

Two different lymph node metastatic patterns of a prostatic cancer.

Among 753 autopsy prostatic cancer cases with a metastasis, 476 (63%) had a lymph node metastasis, whereas 277 (37%) did not. Two different lymph node metastatic patterns were observed: Type 1, combined metastasis involving the pelvic and paraaortic lymph nodes; and Type 2, metastasis to the paraaortic lymph nodes, but not to the pelvic lymph nodes. Type 1 metastasis cases showed a significantly more frequent metastasis to the bladder and rectum, and a less frequent metastasis to the lungs and liver. Hydronephrosis occurred more frequently (P less than 0.01) in the Type 1. Furthermore, in the Type 1 cases the lymph node metastasis appeared to be continuously invasive, but in the Type 2 cases, metastasis appeared to be the skip type or some metastases may have spread via the vertebral vein bypass route and may have been associated with a hematogenous metastasis.

Aorta↗