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Biomedical subjects

K Matsuba

Publications and source records attributed to K Matsuba.

At least 19 recordsLinked to original sources
PubMed1992

Effect of long-term insulin deficiency and insulin treatment on the composition of triglyceride-rich lipoproteins and triglyceride turnover in rats.

The effect of long-term (4 months) insulin deficiency on triglyceride turnover was examined using Triton WR1339 in rats. Triglyceride secretion rate was estimated in rats 2 weeks and 4 months after induction of diabetes with 40 mg/kg of streptozotocin. By the second week diabetic rats showed prominent hyperglycemia and the plasma insulin level was very low. In spite of a lower triglyceride secretion rate compared to non-diabetic control rats, diabetic rats showed normotriglyceridemia. Thus, the estimated fractional catabolic rate for plasma triglyceride was decreased in the diabetic rats of 2 weeks duration. By the fourth month diabetic rats still showed a suppressed triglyceride secretion rate but plasma triglyceride was markedly higher than in the non-diabetic control rats. Therefore, their estimated fractional catabolic rate for plasma triglyceride was severely suppressed. They also showed hyperglycemia and hypercholesterolemia. The triglyceride-rich lipoprotein particles obtained after Triton injection in long-term diabetic rats were significantly cholesterol-enriched and triglyceride-depleted compared to control rats. These changes were already present in 2-week diabetic rats but the magnitude was significantly smaller that those in long-term diabetic rats. All of these abnormalities (including triglyceride turnover and the particle composition) were almost normalized by 2 weeks of insulin treatment (6 units/day). Thus, it was concluded from the present data that duration of insulin deficiency is an important determinant of triglyceride removal rate from the circulation in rats. Further modification of lipid composition of triglyceride-rich lipoprotein particles by long-term insulin-deficiency could be one of the reasons for this removal defect.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1992

Effect of mild diabetes and dietary fructose on very-low-density lipoprotein triglyceride turnover in rats.

Very-low-density lipoprotein (VLDL) triglyceride turnover was examined in mildly streptozotocin (25 mg/kg)-diabetic rats, using Triton WR1339. Diabetic rats fed standard rat chow showed mild hyperglycemia and suppressed levels of plasma insulin. Their triglyceride secretion was significantly suppressed despite an elevated level of plasma free fatty acids. However, the plasma triglyceride level of these diabetic rats was significantly elevated compared with nondiabetic controls. This suggested that the removal of triglyceride from the circulation, as well as its entry into the circulation, was impaired in mildly insulin-deficient rats. Glucose or fructose supplementation (10% in drinking water for 14 days) significantly increased the triglyceride secretion rate of diabetic rats. Especially, fructose supplementation increased plasma insulin to normal levels, but resulted in markedly elevated plasma triglyceride levels (three times higher than glucose-supplemented or chow-fed diabetic rats) despite similar triglyceride secretion rates between the two types of sugar-supplemented diabetic rat groups. This suggested an impairment of triglyceride removal by dietary fructose. The result obtained from chow-fed diabetic rats indicates that mild but significant insulin deficiency resulted in mild hypertriglyceridemia, linked to impaired triglyceride removal rather than to an overproduction of VLDL-triglyceride, despite elevated levels of plasma free fatty acids. Furthermore, fructose feeding induced prominent hypertriglyceridemia not only by stimulating triglyceride secretion, but also by suppressing triglyceride removal from the circulation of mildly diabetic rats.

Animals↗
PubMed1992

Effect of probucol on recovery from streptozotocin diabetes in rats.

The present study was conducted to see the effect of probucol on streptozotocin diabetes in rats. After 2 weeks of a 1% probucol diet, 35 or 50 mg/kg of streptozotocin were intravenously injected into male Wistar rats. All the rats became diabetic 2 days after treatment. Thereafter, in order to see the effect of probucol on spontaneous recovery from streptozotocin diabetes, 25 mg/kg of streptozotocin was injected into rats after two weeks of probucol diet and the diet was continued for additional two weeks. All the rats with a standard diet (group CS, n = 13) and 12 of 13 rats with probucol diet (group PS) became diabetic 2 days after streptozotocin injection. One rate from group PS did not develop diabetes. Two weeks after injection, only 4 of 13 rats in groups CS showed recovery, while 11 of 12 rats in group PS showed recovery from streptozotocin diabetes (p less than 0.05). The average blood glucose levels in group PS were significantly lower than group CS (10.5 +/- 4.6 vs 18.5 +/- 0.6 mM, p less than 0.05). In addition, the pancreatic insulin content of group PS was 8 times greater than that of group CS (0.75 +/- 0.24 vs 0.09 +/- 0.03 mmol/pancreas, p less than 0.01). Thus, the in vivo diabetogenic action of streptozotocin could not be reduced by pretreatment with probucol. However, recovery from streptozotocin diabetes was induced by subsequent treatment with probucol. The precise mechanisms for this phenomenon were not known; but the present findings suggest the protective effect of probucol on beta-cell damage induced by small dose of streptozotocin.

Animals↗
PubMed1991

Effect of probucol on triglyceride turnover in streptozotocin-diabetic rats.

The long-term effect of probucol on triglyceride turnover was examined in streptozotocin (40 mg/kg) diabetic rats. Two diabetic groups were prepared: one group received a probucol-containing (1%) diet (probucol-treated diabetic) and the other standard diet (diabetic control). After 4 months of probucol diet, triglyceride turnover was estimated using Triton WR1339. In diabetic control rats, glucose, triglyceride and cholesterol concentrations in plasma and in the very low density lipoprotein (VLDL) fraction were markedly elevated and plasma insulin was suppressed compared to non-diabetic control rats. There was no significant difference in body weight, plasma glucose and insulin between the 2 diabetic groups. However, the probucol-treated diabetic group showed significantly suppressed levels of triglyceride and cholesterol in total plasma and in the VLDL fraction compared to each corresponding diabetic control value. On the other hand, there were no significant differences in triglyceride secretion rate between the 2 diabetic groups. Newly secreted VLDL particles after Triton injection from diabetic control rats were significantly cholesterol-enriched and triglyceride-depleted compared to those from non-diabetic control rats. However, the composition of those from probucol-treated diabetic rats was similar to that of non-diabetic control group. Prominent hypertriglyceridemia without increase in triglyceride secretion rate in diabetic control group indicates triglyceride removal defect in diabetic rats. Significant suppression of plasma triglyceride level without changes in the triglyceride secretion rate in the probucol-treated diabetic group suggests that probucol stimulated triglyceride removal in diabetic rats. Thus, probucol might normalize VLDL composition, thereby contributing to accelerated triglyceride removal from the circulation of streptozotocin diabetic rats without affecting glucose metabolism.

Animals↗
PubMed1991

Effects of dietary glucose or fructose on the secretion rate and particle size of triglyceride-rich lipoproteins in Zucker fatty rats.

Effects of dietary carbohydrate on the secretion rate and particle size of triglyceride-rich lipoproteins were examined in Zucker fatty rats fed fructose and glucose and were compared with those of Zucker lean rats. Carbohydrates were supplied as 10% drinking solutions for 14 days. As compared with lean rats, Zucker fatty rats had hyperinsulinemia and hypertriglyceridemia associated with an increased rate of triglyceride secretion into the circulation. Feeding fructose and glucose to fatty rats produced an increase in plasma glucose levels, whereas plasma insulin concentrations did not show significant changes. Neither fructose nor glucose supplementation produced significant changes in the rate of triglyceride secretion. Despite this, plasma triglyceride concentrations in fructose-fed fatty rats were twice as high as those in glucose-fed rats or those receiving no supplementary carbohydrate. Particle diameters of lipoproteins of density between 0.96 and 1.006 were larger in fructose-fed fatty rats than in those receiving no sugar. The results suggest that feeding fructose, but not glucose, into fatty rats is associated with an impairment of triglyceride removal and a resultant increase in plasma triglyceride concentration, the latter of which is accompanied by an increase in triglyceride contents in each particle.

Animals↗
PubMed1991

Tension and instantaneous stiffness of single muscle fibers immersed in Ringer solution of decreased tonicity.

Isometric tension and instantaneous stiffness were measured in frog semitendinosus single muscle fibers in both isotonic and hypotonic Ringer solution. In 0.7 and 0.5 x normal Ringer tension increased 17 and 20%, respectively. There was no corresponding increase in the measured stiffness. The increase in tension in hypotonic Ringer could be reversed by the addition of an osmotic equivalent of sucrose to the bathing solution. These findings suggest that the potentiated tension observed in hypotonic Ringer is due to an increased tension per cross-bridge and not to an increase in the number of attached cross-bridges.

Amphibians↗
PubMed1991

Atypical lipoma of the lung.

An unusual endobronchial lipoma characterised by pleomorphic, multinucleated giant cells admixed with mature adipose cells developed in a 52 year old woman, arising from the right middle lobe bronchus. Lobectomy was performed and the postoperative course was uneventful.

Bronchi↗
PubMed1991

Hypoplasia of the internal carotid artery--report of an unusual case.

We present a rare case of unilateral internal carotid artery (ICA) hypoplasia associated with arterial anomalies in the circle of Willis. The ipsilateral middle cerebral artery was supplied via anomalous arteries from the posterior cerebral artery and the ICA. The ipsilateral common carotid artery also originated from the anomalous brachiocephalic trunk. The etiology of the hypoplastic ICA is uncertain, but the associated multiple vascular anomalies support the congenital origin.

Adult↗
PubMed1991

[The CT diagnosis of emphysema and correlation with pathologic findings].

It is difficult to diagnose clinically silent or mild emphysema. The efficacy of CT scans for the diagnosis of emphysema has attracted attention and comparisons have been made between CT images and the pathological grade of emphysema in resected lungs. With a view to determine to what extent high resolution CT images are accurate concerning the diagnosis of mild emphysema, we conducted an extensive comparative study on CT scores of emphysema, based on high resolution CT, the pathology score derived from the cut surface of the lung identical in its plane with that of the CT and destructive index (DI) which is said to be instrumental in representing the degree of deterioration of alveolar walls in the same regions of the lungs. In this study, 42 patients who underwent thoracotomy and their lung specimens including a solitary nodule of considerable size have been employed. The CT scores and pathology scores depend on the picture grading system developed by Thurlbeck and coworkers for the basis of counting. The findings were such that with 1 mm collimation, the CT scores ranged between 12 and 57 with a mean +/- SD of 22.1 +/- 9.6 (n = 35) while with 5 mm collimation, the CT scores ranged between 7 and 46 with a mean +/- SD of 16.5 +/- 8.3 (n = 33). The pathology scores stood at 10 to 57 with a mean +/- SD of 23.2 +/- 9.8 (n = 42).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1991

[Evaluation of pulmonary emphysema with high resolution computed tomography and the effect of smoking].

Cigarette smoking is thought to play an important part in the development of pulmonary emphysema. The authors previously reported on the correlation of high resolution computed tomography (CT) with the pathology grade of emphysema and the destructive index of lung specimens from 42 patients undergoing thoracotomy for a solitary pulmonary nodule. High resolution CT was effective to identify the presence and grade of mild emphysema. The mean per cent predicted FEV1 was 97 per cent. There were 28 smokers and 14 nonsmokers. In this report, the correlation of smoking history with pathology score and high resolution CT was analyzed. There was significant correlation among these indices. These results further support the relationship between smoking and pulmonary emphysema. High resolution CT scan may help in the understanding of the role of cigarette smoking in the development of early pulmonary emphysema.

Adult↗
PubMed1990

Efficacy of cyclosporin A for idiopathic pulmonary fibrosis.

In an 11-year-old girl with severe dyspnoea and cyanosis, idiopathic pulmonary fibrosis (IPF) was diagnosed. The PaO2 of blood could be maintained between 50 mm Hg and 70 mm Hg with a high dose pulse corticosteroid therapy, although this dose could not be reduced. Azathioprine in addition to prednisolone provoked deterioration. Twelve weeks after admission, cyclosporin A (Cs A), a known immunosuppressant, was started together with prednisolone. The PaO2 reverted to normal within 1 month and prednisolone could be tapered off within 6 months. Two years after admission, the patient is free of symptoms on continuous Cs A therapy. This case seems to be the first case successfully treated with Cs A.

Administration, Oral↗
PubMed1990

The diagnosis of mild emphysema. Correlation of computed tomography and pathology scores.

Early and accurate diagnosis of emphysema is said to be invaluable for identification of clinically silent and mild emphysema. Recently, computed tomography (CT) has been much advocated for its efficacy in detailed diagnosis of emphysema, and the results have been compared with the pathology grade of emphysema in resected lung specimens. To assess the ability of high resolution CT scan in detecting and grading mild emphysema, we correlated the high resolution CT scan with the pathology grade of emphysema and the destructive index (DI) of lung specimens from 42 patients undergoing thoracotomy for a solitary pulmonary nodule. The high resolution CT scan and the cut surface of the lung, corresponding exactly to the same plane of the CT scan image, were assessed using the picture-grading system of Thurlbeck and coworkers on a scale of zero to 100. The CT scores for all patients ranged from 12 to 57, with a mean +/- SD of 22.1 +/- 9.6 using 1-mm collimation (n = 35), and from 7 to 46 with a mean +/- SD of 16.5 +/- 8.3 using 5-mm collimation (n = 33). The pathology scores ranged from 10 to 57, with a mean +/- SD of 23.2 +/- 9.8 (n = 42). The DI ranged from 15.4 to 67.1, with a mean +/- SD of 31.4 +/- 10.8 (n = 42). The CT scores using 1-mm and 5-mm collimation correlated significantly with the pathology scores (r = 0.68 and 0.76, respectively, p less than 0.001), and with the DI (r = 0.62 and 0.74, respectively, p less than 0.001). The pathology scores correlated significantly with the DI (r = 0.72, p less than 0.001). We therefore concluded that high resolution CT can help to identify the presence and grading of mild emphysema.

Adult↗
PubMed1990

Abnormal lipoprotein composition in normolipidemic diabetic patients.

To see whether there are any lipoprotein abnormalities in diabetic patients without hyperlipidemia, lipoprotein composition was examined in 75 strictly normolipidemic diabetic patients. Their plasma cholesterol (chol) and triglyceride (TG) were limited to less than 6.0 and less than 1.7 mM, respectively. Body-weight- and age-adjusted normolipidemic healthy subjects served as the control group. Plasma total chol and TG and low-density lipoprotein (LDL-) and high-density lipoprotein (HDL-) chol were identical in the diabetic and control subjects. Total apolipoprotein B (apoB) in the plasma of the diabetic subjects was significantly elevated. The chol-apoB ratio in the TG-rich (very-low-density + intermediate-density) lipoprotein fraction (Sf12-400) of the diabetic subjects was significantly higher than the control value, whereas LDL-apoB levels were increased and chol-apoB ratio in the LDL fraction was significantly suppressed in the diabetic subjects. Because each LDL particle contains only one apoB molecule, apoB and chol-apoB ratio in this fraction can represent particle number and chol loading of the LDL particles, respectively. Thus, these data suggest that LDL particle number is increased, and the particles are chol depleted in diabetic subjects even if they are normolipidemic.

Apolipoproteins↗
PubMed1990

[The relationship between alveolar apertures and alveolar size and smoking history in humans, and experimental studies on air pollutants].

Using surgical specimens from patients with lung tumor, alveolar apertures and alveolar sizes were quantitatively assessed using scanning electron microscopy. Compared with smoking habits, increased apertures, defined as alveolar destruction were observed in patients smoking more than 35 years, whereas alveolar size was increased in patients, with a 15-year smoking history. Experimental studies with exposure to NO2, O3 and H2SO4 mist showed that exposure of NO2 and H2SO4 could induce epithelial injury such as disappearance of cilia in the central airways.

Adult↗
PubMed1990

[Membranous and respiratory bronchiole disease in patients with normal air-flow and mild air-flow limitation].

In order to evaluate the role of membranous (MB) and respiratory bronchioles (RB) in patients with normal and mild airflow limitation, we quantitatively assessed the pathological change of MB, RB and alveoli in the pathological specimens of 42 patients who required surgery for removal of a solitary pulmonary nodule. We also measured the destructive index (DI), to evaluate the destruction of alveolar walls. High resolution CT scan and pulmonary function tests were performed within 1 month of resection. Results of the pulmonary function tests correlated with pathological changes of RB better than with MB. Significant correlation between the emphysema score of resected lung and the pathological change of MB and RB was observed. There was also significant correlations between the CT score or DI and RB changes. However, there was no significant correlation between the CT score or DI and the change of MB. There were significant differences between smokers and nonsmokers in the results of pulmonary function test, pathological changes of RB and severity of emphysema. We postulate that RB is responsible for subtle functional abnormalities in the early stages of chronic obstructive pulmonary disease.

Adult↗
PubMed1990

[The changes in airway structure associated with reduced FEV1].

The purpose of this study is to clarify the changes in the small airways associated with reduced forced expiratory volume in one second (FEV1). We compared the structure of the membranous and respiratory bronchioles of resected lungs from 111 patients with a normal predicted FEV1 to the structure of these airways from 45 patients with an FEV1 reduced below the 95% confidence limits for height and age. Membranous and respiratory bronchioles of less than 2 mm in internal diameter were counted and their diameter and wall thickness were measured. The data show that there were more membranous bronchioles of internal diameter less than 0.4 mm in patients with reduced FEV1. The walls of membranous bronchioles were not increased in thickness but there was an increase in the ratio of wall thickness to lumen diameter. The wall thickness of respiratory bronchioles was increased in the obstructed group and there was also an increase in the ratio of wall thickness to lumen diameter in these airways. We conclude that the patients with obstructive lung disease have a greater increase in wall thickness than can be explained by a reduction in airway support due to emphysema and suggest that the airways obstruction in these patients is due to thickening of the wall and narrowing of the lumen by a chronic inflammatory process.

Adult↗
PubMed1989

Protective effect of probucol on alloxan diabetes in rats.

The diabetogenic action of alloxan is known to be attenuated by several oxygen radical scavengers. The present study was conducted to see if probucol, a drug with strong free radical scavenger action, can reduce pancreatic B-cell damage induced by alloxan in male Wistar rats. After 2 weeks of a 1% probucol diet, 50 mg/kg alloxan was intravenously injected in rats (group PA, n = 34). Urine glucose of most of the injected rats not pretreated with probucol (group A, n = 22) was positive, while more than half of the rats of group PA failed to show urine glucose. The blood glucose level in group PA was significantly lower than that in group A (326 +/- 25 vs. 487 +/- 28 mg/dl, P less than 0.001). Histological examination revealed that most of the pancreatic islets of group A were degranulated, whereas a lot of islets remained unaffected in group PA. Thus, the in vivo diabetogenic action of alloxan was reduced by pretreatment with probucol, although the effect was incomplete. This effect can be explained by probucol's strong free radical scavenger action. Since accumulation of free radicals can be an initial step of B-cell damage in animal models of type 1 (insulin-dependent) diabetes, the drug can be useful for the prevention of type 1 diabetes with its long-term clinical history of safety.

Alloxan↗