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Biomedical subjects

H Shigeta

Publications and source records attributed to H Shigeta.

At least 73 records · Page 4Linked to original sources
PubMed1989

Overt diabetes induced by overeating in neonatally STZ-treated impaired glucose tolerant mice: long-term follow up study.

This study has investigated the effect of a long period of overeating on the glycemic control and pancreatic beta-cell function in neonatally streptozocin treated impaired glucose tolerant mice. Neonatally streptozocin (60 mg/kg) treated male ICR mice with 150-200 mg/dl of fed blood glucose levels were divided into two groups at 6 weeks of age. One group was maintained on a cafeteria diet (SZC) and the other on ordinary mouse chow (SZ) until 30 weeks of age. Normal male ICR mice were divided into a cafeteria diet group (CC) and an ordinary chow group (Cont). SZC and CC consumed 134-124% of the caloric intake in SZ and Cont throughout the study. Marked elevation of the fed blood glucose level was observed and the glucose tolerance was progressively impaired in SZC. On pancreas perfusion at 30 weeks of age, insulin secretion to 30 mM glucose in SZC was significantly decreased compared with that in SZ. That in CC was slightly decreased compared with that in Cont. The pancreatic insulin concentration in SZC was significantly less than that in SZ. We conclude that chronic hyperglycemia, induced by the long period of overeating, accelerated the selective loss of beta-cell sensitivity to glucose. Even in normal mice that did not have marked hyperglycemia, insulin secretion to glucose was suppressed, probably by chronic stimulation of the beta-cell due to the long period of dietary excess.

Animals↗
PubMed1988

Trochlear nerve meningioma in von Recklinghausen's disease.

A trochlear nerve meningioma in a patient with von Recklinghausen's disease is reported. The tumour appeared to have originated from the trochlear nerve itself, having no connection either with the neurinomas present in the adjacent regions, or with the tentorium. Histological examinations revealed that the tumour was a meningotheliomatous meningioma and the trochlear nerve fibres were placed in the periphery of the tumours. It was noteworthy that diplopia was not detected either before or after the resection of the trochlear nerve with the tumour.

Adult↗
PubMed1988

[Two-dimensional and Doppler echocardiographic findings of a sudden death case due to multiple pulmonary thromboses].

This is a case report presenting interesting findings on two-dimensional and Doppler echocardiograms due to multiple pulmonary thromboses. A 67-year-old woman had a history of surgery for colon polyps in August, 1986. After surgery, she suffered from tachycardia and dyspnea, and was admitted to our hospital because of a loss of consciousness. Sinus tachycardia, complete right bundle branch block and T-wave inversion in leads III, aVF and V1-4 were observed on her electrocardiogram. Cardiomegaly was noted on her chest radiograph. On the third hospital day, echocardiography was performed. On two-dimensional echocardiography, marked right ventricular dilatation with hypokinesis of the wall, and a flattened interventricular septum were observed on the short-axis view, and M-mode echocardiograms showed disappearance of the E wave and delay of the opening of the tricuspid valve, resulting in a monophasic triangular pattern. Doppler echocardiography showed the tricuspid valve flow to be delayed, mainly observed during atrial systole. These findings indicate decreased right ventricular compliance. The patient died on the 6th hospital day, and multiple new and old thrombi were found in the pulmonary artery at autopsy.

Aged↗
PubMed1988

[Traumatic subarachnoid hemorrhage--clinical study of 16 cases].

Three hundred and eighty three cases with head injury were admitted to our hospital during period from March 1985 to October 1986. Among these cases, 16 (4.2%) had subarachnoid hemorrhage as revealed on computerized tomography (CT) scan; other CT findings included epidural hematoma, subdural hematoma and/or cerebral contusion. Traumatic subarachnoid hemorrhage was most frequently found in the ambient and/or sylvian fissure. This suggests that head blow tended to product shear strain at the brainstem and in the direction from temporal tip to frontal base. Furthermore tentorial edge and sphenoid ridge may have played an important role in producing subarachnoid hemorrhage. Of the 6 cases with the hemorrhage localized in the unilateral cisterns, 5 cases had the hemorrhage in the cisterns opposite to the blow site. This suggests that shear strain was produced more strongly at the opposite side to the blow site. The cases with subarachnoid hemorrhage in the prepontine and/or interpeduncular cistern had severe brainstem damage and their prognosis was very poor, while those with the hemorrhage localized in the ambient cistern, quadrigeminal cistern and/or sylvian fissure without other findings had good prognosis.

Adolescent↗
PubMed1987

Somatostatin suppresses plasma aldosterone concentration in a case of Bartter's syndrome.

The study was conducted to examine the effect of somatostatin on activated renin-angiotensin-aldosterone system in a case of Bartter's syndrome. After 60 minutes of 500 micrograms of somatostatin infusion, the plasma aldosterone concentration was reduced from the basal level of 250 pg/ml to 140 pg/ml, whereas plasma renin activity remained at the basal level. This result suggests that somatostatin may specifically inhibit aldosterone secretion in Bartter's syndrome and the agent can be applied to a treatment of this syndrome.

Adrenocorticotropic Hormone↗
PubMed1986

[Right and left coronary arteries-right atrial fistulas diagnosed by Doppler echocardiography: a case report].

An interesting case of right and left coronary arteries-right atrial fistulas diagnosed by Doppler echocardiography was presented. A 59-year-old woman was referred for evaluation of her continuous murmur. A thrill was palpable at the left sternal border in the third intercostal space. The proximal portions of the dilated right and left coronary arteries and distal portions of the tortuous and converging fistulas of both coronary arteries were imaged by two-dimensional echocardiography. Bidirectional continuous turbulent Doppler signals were detected in the proximal portions of the dilated right and left coronary arteries, in the distal portions of the fistulas around the crux and in the right atrium. These findings facilitated our diagnosis of right and left coronary arteries-right atrial fistulas. The flow velocity at the ostium of the right coronary artery was highest and nearly the same as the flow velocity (about 2 m/s) obtained by continuous wave Doppler from the maximum point of the thrill. The maximum pressure difference was considered located at this portion. Selective coronary angiography confirmed the right coronary artery and left main trunk-left circumflex coronary artery to be large, elongated and tortuous. These fistulas were communicating with the right atrium. This case demonstrates the usefulness of Doppler echocardiography in the noninvasive diagnosis of coronary arteriovenous fistula.

Arteriovenous Malformations↗
PubMed1985

Effects of aspartame on diabetic rats and diabetic patients.

The effects of aspartame (L-aspartyl-L-phenylalanine methyl ester) on plasma glucose and insulin levels were investigated in diabetic rats and patients with non-insulin-dependent diabetes mellitus. The oral administration of 0.45 mg aspartame per 100g body weight, which is equivalent to 150 mg of glucose in sweetness, to streptozotocin-induced diabetic rats had no effect on the plasma glucose or insulin levels. Also, 225 mg oral aspartame loading, which is equivalent to 75 g of glucose in sweetness, to patients with non-insulin-dependent diabetes mellitus did not increase plasma glucose or insulin levels, although 75 g of oral glucose loading increased plasma glucose and insulin levels in diabetic patients as expected. Aspartame ingestion for three days at a dose of 24-48 mg per day and the intake of snacks flavored with 240 mg of aspartame also did not increase fasting plasma glucose levels. These results suggest that acute administration of aspartame has no influence on plasma glucose or insulin levels in diabetic rats and patients with non-insulin-dependent diabetes mellitus.

Adult↗
PubMed1983

[Two-dimensional echo-cardiographic study on left atrial thrombi in patients with a mitral prosthetic valve].

Two-dimensional echocardiographic study was performed to detect left atrial thrombi in 33 patients with a prosthetic mitral valve. The subjects were 9 males and 24 females and their ages ranged from 21 to 61 years (average 43.2 years). Their prosthetic valves consisted of 18 Hancock, three Carpentier-Edwards, four Björk-Shiley, four Starr-Edwards and four St. Jude Medical valves. Two-dimensional echocardiograms were obtained using a Toshiba SSH-11A echograph with an electronic phased-array scanner. The left parasternal, apical, subcostal and right parasternal windows were used to detect left atrial thrombi. In five of the 33 patients, a left atrial thrombus was demonstrated as a mass echo attached to the posterior wall of the left atrium. The clinical and echographic features of five patients with a left atrial thrombus (Group A) were compared to those of 28 patients without it (Group B). The average age at the time of operation was 44.6 +/- 9.7 years in Group A and 43.0 +/- 9.5 years in Group B, showing no difference between the two groups. In 10 of the 33 patients, a left atrial thrombus was confirmed by the initial operation. In only one of these 10 patients, a left atrial thrombus was demonstrated by post-operative two-dimensional echocardiographic examination. The presence or absence of a left atrial thrombus in the pre-operative stage did not clearly relate to the occurrence of a left atrial thrombus in the post-operative stage. The cardio-thoracic ratio was significantly greater (p less than 0.01) in Group A (74.4 +/- 6.3%) than in Group B (58.1 +/- 8.1%). Left atrial dimension by M-mode echocardiograms was significantly greater (p less than 0.05) in Group A (70.6 +/- 11.3 mm) than in Group B (51.6 +/- 7.7 mm). The length of the pseudo-septalized left ventricular posterior wall was longer (p less than 0.05) in Group A (34.0 +/- 11.5 mm) than in Group B (12.8 +/- 9.4 mm). The angle between the perpendicular to the mitral annulus and the upper part of the interventricular septum was significantly greater (p less than 0.01) in Group A (58.6 +/- 18.0 degrees) than in Group B (18.8 +/- 9.6 degrees). The characteristics observed in Group A were thought to be caused mainly by the giant left atrium. Therefore it is concluded that there is a close relationship between left atrial thrombi and the giant left atrium in patients with a mitral prosthetic valve.

Adult↗