Biomedical subjects

H Yoshimatsu

Publications and source records attributed to H Yoshimatsu.

At least 91 records · Page 5Linked to original sources

PubMed1993

[Evaluation of results following thymectomy in myasthenia gravis].

Sixty-nine patients with generalized myasthenia gravis underwent thymectomy consecutively between 1980 and 1991 and were evaluated 1 month to 120 months after operation. Extended thymectomy was performed in 43 patients and other procedures in 26. The effect of thymectomy were as follows: 14.5% of the patients achieved complete remission (no symptoms, no medication), 73.9% showed improvement; in total 88.4% had palliation. The long-term changes of the remission rate at one and five years after operation were 11.5% and 19.2%, and showed a delayed remission. The long-term changes of the improvement and palliation rate were 55.7% and 67.2% at one year, 69.2% and 88.5% at five years after operation. There was significant difference in remission rate according to age at the time of operation and age of onset, but the response did not depend on sex, presence or absence of thymoma, preoperative duration of illness, Osserman's type and operative procedure.

Adolescent↗

PubMed1992

Effects of cholecystokinin on sympathetic activity to interscapular brown adipose tissue.

The effects of injecting cholecystokinin (CCK) into the third ventricle or into selected hypothalamic sites on electrical firing rate of sympathetic nerves to interscapular brown fat (IBAT) has been investigated in anesthetized rats. The hypothesis for these experiments was that there was a reciprocal relationship between sympathetic activity and food intake. Since CCK reduces food intake we predicted that CCK would stimulate sympathetic activity to IBAT. Following the injection of CCK into the third ventricle there was an increase in firing rate of sympathetic nerves to IBAT. When the peptide was injected into either the ventromedial hypothalamic nucleus (VMH) or lateral hypothalamic area (LHA), there was likewise an increase in sympathetic firing rate. The injection of CCK into the paraventricular nucleus produced a small decrease in sympathetic firing rate. In contrast, no effect was seen following injection of CCK into the preoptic area or dorsomedial hypothalamic nucleus. Thus, the VMH or LHA appear to be the principal hypothalamic areas mediating the stimulation of sympathetic activity to IBAT which is observed following the third ventricular injection of CCK. These studies support the hypothesis of a reciprocal relationship between the effects of CCK on the thermogenic component of the sympathetic nervous system and food intake and identify the VMH and LHA as the primary sites for this effect.

Adipose Tissue, Brown↗

PubMed1992

Zucker obese rats: defect in brain histamine control of feeding.

Manipulation of hypothalamic histamine produced different effects on feeding between the Zucker obese (fa/fa) and their lean littermate rats (Fa/-). Infusion of a histamine H1-receptor antagonist into the third cerebroventricle elicited feeding in the lean and Wistar King A rats, but it did not affect feeding in the obese rats. To enhance hypothalamic neuronal histamine, thioperamide, and H3-receptor antagonist, was similarly infused. The lean and Wistar rats decreased their food intake after the infusion, but thioperamide produced no significant effect on feeding in the obese rats. Infusion of histamine into the third cerebroventricle mimicked the effects of thioperamide on feeding: reduction of food intake in the lean and Wistar rats, but no significant change in the obese rats. Hypothalamic histamine of the obese rats (0.430 nmol/g) was significantly lower than the lean (1.209 nmol/g) and Wistar rats (4.838 nmol/g). The histamine concentration of the cerebral cortex in the obese rats was also lower than the non-obese animals. The results indicate that the feeding abnormality of Zucker obese rats may be at least due to disturbance of histamine suppressive signals both at presynaptic and postsynaptic levels.

Animals↗

PubMed1992

Acceleration of tail pinch-induced feeding in rats by analgesic effect of neurotropin.

Mechanisms of tail pinch-induced feeding and effects of neurotropin (NSP), an extract from the inflamed skin of rabbit inoculated with vaccinia virus, on behavioral responses were investigated in rats. Treatment of a 5-min tail pinch (tail pinch I) induced feeding response. An intensified 15-min tail pinch (tail pinch II) provoked emotional reactions besides feeding behavior. The rate of food intake (food intake/tail pinch duration) during tail pinch II was less than that at tail pinch I. Intraperitoneal administration of NSP (100 mg/kg/day) by itself produced no remarkable change in feeding or emotional behavior. However, NSP-treated rats increased eating size and prolonged eating duration during tail pinch I. Pretreatment of NSP increased feeding behavior more potently at tail pinch II than at tail pinch I and decreased the incidence of emotional reactions at tail pinch II. The results suggest that NSP, by its analgesic action, may modulate behavioral responses during tail pinch treatment through selective blockade of the nociceptive and feeding-inhibitory information, but not through the nonnociceptive and feeding-excitatory signals.

Analgesics↗

PubMed1992

Advance shift of feeding circadian rhythm induced by obesity progression in Zucker rats.

To determine the relation between the circadian rhythm of ingestive behavior and the progression of obesity in Zucker rats, ingestion and ambulation were analyzed at four different developmental stages. The obese rats were disrupted gradually in nocturnal patterns of feeding, drinking, and ambulation with the progression of obesity, although the lean littermates maintained the patterns during whole test periods. Analysis of autocorrelogram revealed that circadian rhythms of those behaviors remained throughout the whole test periods. Least-squares spectrum ascertained the following. 1) The obese made advance shift of acrophases in feeding and drinking circadian cycles, but not in ambulation. 2) Amplitudes in those behavioral measures decreased with the progression of obesity. 3) Mesor in the obese feeding was not affected, although that in the lean feeding decreased. The findings indicate that disruption of the light-dark cycle in ingestion of the obese was not due to disappearance of circadian rhythm but to transformation by both decreased amplitude and advance shift of the circadian cycle.

Animals↗

PubMed1992

[Effective continuous hemofiltration and plasma exchange for the treatment of subacute type fulminant hepatic failure].

By combination of continuous hemofiltration (CHF) with plasma exchange therapy we successfully treated a patient with subacute type fulminant hepatitis to keep her consciousness alert. The patient was a 55-year-old woman who admitted because of severe jaundice. On the 51st day after the onset she had consciousness disturbance and was transferred to our hospital. We started the therapy of CHF and plasma exchange at the patient's hepatic coma grade 4. On the 5th day her consciousness level recovered to grade 2 and we could keep the level for almost 2 weeks. This combination therapy seemed good not only for the improvement of consciousness of patients in hepatic coma but also to support the hepatic function of almost ahepatic patients.

Female↗

PubMed1991

2,5-Anhydro-D-mannitol: its unique central action on food intake and blood glucose in rats.

Peripheral administration of D-fructose has been reported to decrease food intake, and its 2-deoxy analogue, 2,5-anhydro-D-mannitol (2,5-AM), increased food intake and decreased blood glucose in rats. In the present study, 2,5-AM was selected for comparison with well-known 2-deoxy analogues of glucose. Infusion of 2,5-AM into the rat third cerebroventricle at 11.00 h induced feeding dose dependently (Y = 0.63 logX-1.20, r = 0.95, P less than 0.05). Rats treated with 2,5-AM at a maximal effective dose of 24 mumol/rat ate meals most persistently (P less than 0.05). No periprandial drinking was observed. Ambulatory activity increased concomitantly with feeding, but did not exceed the activity normally associated with a meal. Infusion of 24 mumol 2,5-AM into the third cerebroventricle induced no substantial change in plasma glucose or insulin in any 60-min experimental period. Unilateral microinfusion of 1.2 mumol 2,5-AM induced feeding in all 6 rats (P less than 0.01) when a cannula tip was located in the ventromedial hypothalamic nucleus (VMH), but not in the lateral hypothalamic area (LHA). These findings indicate that feeding elicitation may be due to disinhibition by 2,5-AM through the VMH. This is quite unique compared to the action mechanisms of hexose, pentose and their analogues, except 2,5-AM.

Animals↗

PubMed1991

The surgical treatment of a thoracoabdominal aortic aneurysm with total preservation of the intercostal and lumbar arteries using a permanent bypass technique--a case report.

A 44 year old man underwent successful surgery for a thoracoabdominal aortic aneurysm using a permanent bypass graft and aneurysmoplasty. This technique reduces visceral ischemia to a minimum and the aneurysmoplasty, through total preservation of the intercostal and lumbar arteries, can avoid paraplegia caused by spinal cord ischemia. Our technique is recommended as it can be performed easily, safely, and effectively without heparinization, temporary shunts or bypass perfusion.

Abdominal Muscles↗

PubMed1991

Neuropeptide Y suppresses sympathetic activity to interscapular brown adipose tissue in rats.

To investigate the effects of neuropeptide Y (NPY) on sympathetic nerve activity to interscapular brown adipose tissue (IBAT), we injected NPY into the third cerebroventricle (icv), medial preoptic area (MPOA), anterior hypothalamic area (AHA), paraventricular hypothalamic nucleus (PVN), ventromedial hypothalamic nucleus (VMN), and lateral hypothalamic area (LHA) of anesthetized rats. Multiunit discharges from sympathetic nerves to IBAT were recorded electrophysiologically. The icv injection of NPY suppressed sympathetic nerve activity in a dose-dependent manner, followed by a gradual recovery. The microinjection of NPY (25 pmol) unilaterally into the PVN also significantly suppressed the sympathetic nerve activity to IBAT. In contrast, microinjection of NPY into the MPOA significantly increased the sympathetic nerve activity. The injection of saline into either the PVN or MPOA had no significant effect on sympathetic nerve activity. The microinjection of NPY (25 pmol) into the AHA, VMN, or LHA did not change sympathetic nerve activity to IBAT. We conclude that central administration of NPY affects the sympathetic nerve activity to IBAT and that the suppressive effect of NPY, which may act in part through the PVN, is dominant to the stimulatory effect. The result is consistent with the hypothesis that NPY is a neurochemical modulator of the sympathetic nervous system which controls energy expenditure in IBAT.

Adipose Tissue, Brown↗

PubMed1991

Adrenal sympathetic nerve activity in response to hypothalamic injections of 2-deoxy-D-glucose.

Adrenal sympathetic nerve activity after microinfusion of 2-deoxy-D-glucose (2-DG) into various hypothalamic nuclei was investigated in anesthetized rats. Infusion of 2-DG into the ventrolateral portion of the lateral hypothalamic area (LHA) induced a large and long-lasting increase (greater than 60 min) in adrenal nerve activity. In contrast, infusion into the dorsal or medial portion of the LHA tended to produce a small decrease with a return to baseline within approximately 60 min after the end of the infusion. The direct administration of 2-DG into either the paraventricular nucleus or the dorsomedial hypothalamic nucleus produced a strong inhibition of adrenal nerve activity. Infusions into the ventromedial hypothalamic nucleus induced either a decrease of adrenal nerve activity or were without effect. These findings provide evidence that induction of glucoprivation in the hypothalamus with 2-DG can excite or inhibit adrenal nerve activity, depending on the hypothalamic region. These data also indicate that the ventrolateral portion of the LHA plays an important role in the regulation of adrenal catecholamine secretion in response to glucoprivic conditions in the central nervous system.

Adrenal Glands↗

PubMed1991

[Multiple pulmonary metastasis from histologically benign giant cell tumor of the right radial olecranon].

An unusual case of a benign giant cell tumor of bone with pulmonary metastasis is reported. A 23-year-old man had a painful tumor in the right radial olecranon that proved to be a histologically benign giant cell tumor. Curettage and bone-grafting were performed, but the tumor recurred twice, 8 months and 20 months after initial treatment. Histological examination of biopsy materials from the recurring tumor showed typical benign giant cell tumors. Five years later, wedge resections were performed for bilateral pulmonary nodules, which had been detected by chance. The pulmonary nodules turned out to be histologically similar to the primary tumor of the olecranon. Almost 7 years later, he was asymptomatic and the chest radiograph was clear, and there was no local recurrence of the lesion.

Adult↗

PubMed1991

Thymectomy in ulcerative colitis: a report of cases over a 13 year period.

Seventy eight patients with ulcerative colitis were treated by thymectomy combined with conventional therapy. An interim analysis was made after a median follow-up of 40 months in the thymectomized group and after 25 months in 173 from a non-thymectomized group. The percentage of remission periods in the thymectomized group was significantly higher than that in the non-thymectomized group as estimated by the "patient-month" method. Histological examination of the excised thymus revealed hyperplasia of the thymic epithelial cells and/or the formation of lymphoid follicles. Anticolon antibody activity of the serum from the thymectomized patients decreased gradually and disappeared in 5 years or more. "Thymectomy via the suprasternal notch with parasternal incision" which was applied in this study, is simple and not invasive. Therefore, it is recommended that thymectomy should be considered as one of the treatment for patients who are resistant to conventional therapy.

Adolescent↗

PubMed1990

Hypothalamic neuronal histamine modulates ad libitum feeding by rats.

Manipulating histamine endogenously, its effects on brain functions were assessed in rats. alpha-Fluoromethylhistidine (FMH), an inhibitor of histamine synthesis, elicited feeding (P less than 0.01) after intra-third cerebroventricular infusion at the early light phase when hypothalamic histamine was normally highest. No periprandial drinking was observed. The effect of FMH was attenuated, and thioperamide, an antagonist of auto-inhibitory effects on both histamine synthesis and release at presynaptic H3-receptor, conversely suppressed food intake (P less than 0.05), when these probes were carried out during the minimum histamine level early in the dark period. Bilateral microinfusion of FMH into the ventromedial hypothalamus (VMH) and the paraventricular nucleus (PVN) selectively induced feeding, but the infusion into the remaining sites of the hypothalamus had no effect. These data show that neuronal histamine plays a physiological role in feeding suppression through the VMH and the PVN in the rat.

Animals↗

PubMed1990

Left ventricular rupture following mitral valve replacement--a report of two cases.

Left ventricular rupture is a rare and usually fatal complication of mitral valve replacement, and we report herein, 2 successfully treated cases of type III left ventricular rupture. The laceration in the posterior ventricular wall was repaired by a wide buttressed mattress suture with teflon felt belts on either side, then covered with Oxycel and fibrin glue or a large patch and fibrin glue. Naturally, the operation must be performed carefully and gently, however, the most important etiologic factor of left ventricular rupture is the extremely friable myocardium due to aging and a long history of heart disease. Utilizing fibrin glue for successfully repairing the rupture proved very effective.

Aged↗

PubMed1990

Effect of corticotropin releasing hormone and neuropeptide Y on electrophysiological activity of sympathetic nerves to interscapular brown adipose tissue.

It has been proposed that there is a reciprocal relationship between food intake and sympathetic activity. To test this hypothesis corticotropin releasing hormone, which suppresses feeding behavior, and neuropeptide Y, which stimulates it, were injected intracerebroventricularly and sympathetic nerve activity to interscapular brown adipose tissue measured in anesthetized rats. Multi-unit discharges of sympathetic nerves to interscapular brown adipose tissue were recorded electrophysiologically. The intracerebroventricular injection of corticotropin releasing hormone (250 and 500 pmol) increased sympathetic nerve activity and the intracerebroventricular injection of neuropeptide Y (250-500 pmol) suppressed sympathetic nerve activity in a dose-dependent manner. The intracerebroventricular injection of vehicle did not affect sympathetic nerve activity. The result is consistent with the hypothesis that these brain peptides are neuromodulators of the sympathetic nervous system which may control energy expenditure in interscapular brown adipose tissue. The effects of these two brain peptides on sympathetic nerve activity are opposite to their effects on feeding behavior suggesting that sympathetic activity and food intake may be reciprocally related.

Action Potentials↗

PubMed1990

Preoptic area injection of corticotropin-releasing hormone stimulates sympathetic activity.

To investigate the sites of action of corticotropin-releasing hormone (CRH) on sympathetic nerve activity to interscapular brown adipose tissue (IBAT), we injected CRH into the third cerebroventricle, medial preoptic area (MPOA), and other hypothalamic areas in anesthetized rats. The multiunit discharges of sympathetic nerves to IBAT were recorded electrophysiologically. The intracerebroventricular injection of CRH increased sympathetic nerve activity in a dose-dependent manner over the range 250-1,000 pmol. The microinjection of CRH (200 pmol) into the unilateral MPOA increased the sympathetic nerve activity to IBAT by +150.6 +/- 25.9% at 30 min after injection. However, the injection of saline (0.15 M NaCl) and glucagon (200 pmol) into the MPOA did not increase sympathetic nerve activity. The microinjection of CRH (200 pmol) into the anterior hypothalamic area, paraventricular hypothalamic nucleus, ventromedial hypothalamic nucleus, and lateral hypothalamic area had no significant effect on nerve activity. We conclude that central administration of CRH increases the sympathetic nerve activity to IBAT and that the MPOA is one of the sites for this action. The result is consistent with the hypothesis that CRH is a neurochemical stimulator of the sympathetic nervous system, which may be involved in control of energy expenditure in rodents.

Adipose Tissue, Brown↗

PubMed1990

Inflammatory bowel diseases and thymus disorder: reactivity of thymocytes with monoclonal antibodies.

Thymectomy is one of the most effective means of treating myasthenia gravis (MG). Formation of lymphoid follicles in the thymus is seen at high rate in ulcerative colitis (UC) as well as MG. We examined the subsets of lymphocytes in the thymuses taken from patients with inflammatory bowel diseases (IBD), using OK series monoclonal antibodies. Decreases in OKT8 (CD8)-, 6(CD1)- and 10-positive cells and an increase of IA1-positive cells were observed in UC. In contrast, there were no significant changes in Crohn's disease (CD). Therefore, the thymocytes from UC appear to consist of comparatively matured cells under the influence of thymic hormone.

Adult↗

PubMed1989

Hypothalamic sites of neuronal histamine action on food intake by rats.

To identify sites of histaminergic modulation of food intake, histamine H1-receptor antagonist was microinfused into the rat hypothalamus, the ventromedial hypothalamus (VMH), the lateral hypothalamus (LHA), the paraventricular nucleus (PVN), the dorsomedial hypothalamus (DMH), or the preoptic anterior hypothalamus (POAH), during the early light period. Feeding, but not drinking, was elicited in 100% of the rats (P less than 0.01) that were bilaterally microinfused with 26 nmol chlorpheniramine into the VMH. Unilateral infusion into the VMH did not affect food intake at doses of 26 or 52 nmol. Feeding was also induced by bilateral microinfusion into the PVN, but only the 52 nmol dose was effective. Bilateral infusions into the LHA, the DMH or the POAH did not affect ingestive behavior. Feeding induced by an H1-antagonist was completely abolished in all 7 rats tested when endogenous neuronal histamine was decreased by pretreatment with alpha-fluoromethylhistidine (100 mg/kg). The findings suggest that H1-receptors in the VMH and the PVN, but not in the LHA, the DMH or the POAH, may be involved in histaminergic suppression of food intake.

Animals↗