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Biomedical subjects

R Watanabe

Publications and source records attributed to R Watanabe.

At least 253 records · Page 14Linked to original sources
PubMed1990

[A case of cardiac tumor found during examination in orthostatic hypotension].

We report a case of left atrial myxoma found when examination was made for the cause of orthostatic hypotension. The case was that of a man of 61 years of age. For the previous 2 years, the man had felt dizzy only at the standing or sitting position. The blood pressure was 90/50 at recumbency and 64/40 at the sitting position. Echocardiographic study revealed a left atrial tumor, which fell into the left ventricular cavity and prevented the blood from filling the left ventricular cavity. This effect was more severe at the sitting position than at recumbency. Resection of the tumor was carried out. It was a myxoma with a diameter of 3.5 cm with a stalk adhering to the postero-inferior wall of the left atrium. After the removal of the tumor, the patient's complaint and orthostatic hypotension disappeared; blood pressure was 102/60 at recumbency and 98/64 at sitting position. Orthostatic dizziness has been reported in some cases as one of the symptoms of the intracardiac tumor. But the state of aggravation at the sitting position has never been observed during actual echocardiographic study. The myxoma adhered to the postero-inferior wall of the left atrium, which site might be associated with the symptom (orthostatic hypotension).

Diagnosis, Differential↗
PubMed1989

Acute aortic occlusion.

Acute occlusion of the infrarenal abdominal aorta is a vascular catastrophe, and the prognosis remains poor. This report describes a 52-year-old man with acute occlusion of the abdominal aorta following acute myocardial infarction. He was successfully treated with a transfemoral embolectomy with the use of a Fogarty catheter. The postoperative course was uneventful.

Acute Disease↗
PubMed1989

Cultured skin fibroblasts from patients with porokeratosis are hypersensitive to the lethal effects of X-radiation.

Porokeratosis is an autosomal dominant inherited skin disorder. The lesions are characterized by localized abnormal keratinization and may develop into malignant tumors. To determine the cellular basis of the cancer susceptibility associated with this skin condition, we examined the colony-forming ability of X-ray or ultraviolet (UV) light irradiated, cultured fibroblasts derived from porokeratosis patients' normal-appearing skin. Four fibroblast strains derived from four porokeratosis patients' skin were significantly hypersensitive to the lethal effects of X-radiation. However, they all showed a similar sensitivity to strains from normal donors to 254 nm UV light. The hypersensitivity to X-ray radiation in cultured skin fibroblasts from porokeratosis patients suggests an inherent instability of cellular DNA and may probably be associated with the cancer-prone nature of this skin condition.

Cell Survival↗
PubMed1989

[Synthesis of thieno[2,3-d]pyrimidine derivatives and their antifungal activities].

4-Chlorothieno[2,3-d]pyrimidines were prepared by the chlorination of 4-oxo-3,4-dihydrothieno[2,3-d]pyrimidines with phosphoryl chloride. 4-Oxo-3,4,5,6,7,8-hexahydro[1]-benzo- and 4-oxo-6-phenylthieno[2,3-d]pyrimidine were synthesized by the cyclization of 2-acylaminothiophene-3-carboxamide derivatives with base. 2-Methyl-4-oxo-3,4-dihydrothieno[2,3-d]pyrimidine was prepared by the treatment of 2-methyl-4-trichloromethylthieno-[2,3-d]pyrimidine with sodium hydroxide in aqueous methanol. A series of 4-alkylamino- and 4-arylaminothieno[2,3-d]pyrimidines were synthesized by the nucleophilic substitution of 4-chlorothieno[2,3-d]pyrimidines with various amines. These compounds were evaluated for antifungal activity against Piricularia oryzae. The preventive effects on Rice blast, Sheath blight, and Cucumber powdery mildew were also determined by pot tests.

Drug Resistance, Microbial↗
PubMed1989

Assay method for single-chain urokinase-type plasminogen activator.

A new assay method for measuring single-chain urokinase-type plasminogen activator (scu-PA) activity by quantitative calorimetric assay method is described. The serine enzyme u-PA activates plasminogen to plasmin, and scu-PA is a precursor protein obtained from a tissue culture of human kidney cells. The scu-PA solution was activated by plasmin to two-chain u-PA, which releases p-nitroaniline from pyro-Glu-Gly-Arg-pNA, and the optical density at 405 nm was measured. One unit of scu-PA was defined on the basis of 1 nmol of p-nitroaniline released from the substrate per second. One unit of scu-PA was found to be equivalent to 335 u-PA (two-chain) units (IU).

Calorimetry↗
PubMed1989

Evaluation of leg edema using a multifrequency impedance meter in patients with lymphatic obstruction.

To evaluate quantitatively local edema, electrical tissue impedance in the leg was measured with a multifrequency impedance meter in 10 patients without edema and in 10 other patients with lymphedema after hysterectomy for uterine cervical cancer (Groups 1 and 2, respectively). Equivalent resistivity of extra- and intracellular fluid (RE, RI, respectively) and the ratio RI/RE were calculated. The difference in mean RE between Groups 1 and 2 was significant (p less than 0.05). In four patients in Group 1 and nine in Group 2, simultaneous measurements were carried out on both legs. The differences between mean RE and RI/RE in Group 2 were significant (p less than 0.05, p less than 0.025, respectively). In these 13 patients, correlation coefficients between the ratio of cross-sectional areas of both legs, and both RE and RI/RE were -0.614 (p less than 0.05) and 0.805 (p less than 0.001), respectively. The results suggest that RE and RI/RE could be used as sensitive indicators of local edema.

Adult↗
PubMed1988

Managing diabetic surgical patients with glucose-free saline and insulin.

Sixty-one people with glucose intolerance received a glucose-free solution during surgery. If their blood glucose levels rose above 200 mg/dl, they were given insulin intravenously, according to a rate algorithm reported elsewhere. None of the cases judged to be borderline required any insulin during their operations. Ten percent of the diabetics who were being treated with diet alone, and 40% of those using hypoglycemic agents or insulin, did require insulin. Insulin was delivered at an average rate of 2.1 +/- 5.2 U/h and controlled the serum glucose levels within a range of 132 +/- 32 mg/dl. This suggests that half of all diabetics undergoing surgery require only a glucose-free solution for fluid replacement to maintain their glucose levels below 200 mg/dl, and that insulin infusion is an appropriate means to control hyperglycemia during surgery.

Blood Glucose↗
PubMed1988

Interindividual changes in volume of distribution of cefazolin in newborn infants and its prediction based on physiological pharmacokinetic concepts.

The purpose of this study was to investigate factors affecting the volume of distribution of cefazolin (a beta-lactam antibiotic) in newborn infants with bacterial infections, and to propose a method for predicting the volume of distribution at steady state per body weight (Vdss/BW). Cefazolin and tobramycin (an aminoglycoside) were simultaneously given to newborn infants (aged 2 to 28 d), and plasma concentration-time data were analyzed on the basis of model-independent moment analysis. The Vdss/BW values ranged from 0.212 to 0.373 L/kg for cefazolin and from 0.384 to 0.541 L/kg for tobramycin. The unbound fraction of cefazolin in plasma (fp) fluctuated widely, from 0.22 to 0.83, among patients. The Vdss/BW value for cefazolin was characterized by both large extracellular water volume and a remarkable change in fp, and could be predicted as a function of fp using physiological pharmacokinetic concepts. Moreover, interindividual changes in the unconjugated bilirubin:albumin molar ratio were predominantly responsible for the individual variation in the fp values of cefazolin in newborn infants.

Blood Proteins↗
PubMed1988

Stress fracture of the body of pubis in a pregnant woman. Case report.

A case with stress fracture of the body of the pubic bone which occurred in a 35-year-old pregnant woman is described. No underlying pathologic process was found and it would seem that the mechanical load acting on the pubic bone to cause stress fracture is brought about by both the muscle imbalance and ligament laxity. In a few weeks after delivery, the fracture showed a complete bony union.

Adult↗
PubMed1988

Nonsyndromatic paucity of intrahepatic bile ducts in congenital syphilis. A case report.

The first case of nonsyndromatic paucity of the intrahepatic bile ducts is reported in congenital syphilis. The patient, a 2-week-old female, was born at the 31st week of gestation, weighing 1,910 g. She had a high titer of IgM antibody to Treponema pallidum and sera from both parents also showed a positive reaction in the hemagglutination test for Treponema pallidum. The patient had hepatosplenomegaly and increasing jaundice, and died of respiratory failure on the 70th hospital day. Autopsy examination revealed paucity of the intrahepatic bile ducts, prominent giant cell transformation of hepatocytes, cholestasis and extramedullary hematopoiesis of the liver. The ratio of the number of intrahepatic bile ducts to that of the portal tracts was approximately 0.2:1. There was marked proliferation of atypical bile ductules at the margin of the portal tracts. The exact relation of this paucity to Treponema pallidum remains unknown.

Autopsy↗
PubMed1988

[Sex and age differences in the effect of verapamil on rat cardiac function].

The author reports that a relatively high dose of verapamil produces sex-related cardiac effects, especially on the conducting system in adult rats. A single dose of verapamil (0.5-1 mg/kg, i.v.) caused a marked AV block and a reduction in heart rate to 50-60% in adult males, but not in females. There was no sex difference in the hypotensive effect of verapamil. At 3, 5 or 7 weeks of age, verapamil (1 mg/kg, i.v.) induced a 10-20% reduction of the heart rate without AV block in both male and female rats. In 8-week-old male rats, the reduction in the heart rate became apparent, and AV block appeared following a single i.v. injection of verapamil. The adult pattern in cardiac response to verapamil was observed at 11 weeks of age and afterward. Castration in adult male and female rats resulted in an intermediate pattern of the response to verapamil in intact male and female rats. Acute treatment with testosterone (20 mg/kg, s.c.) in castrated male and female rats induced a decrease in the basal heart rate and increased the cardiac responsiveness to verapamil in castrated female rats. Estradiol-17 beta failed to alter the responsiveness of castrated rats to verapamil. These results suggest that testosterone may play a role in the sex difference of the cardiac responses to verapamil in rats.

Age Factors↗