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Biomedical subjects

Y Kishi

Publications and source records attributed to Y Kishi.

At least 145 records · Page 8Linked to original sources
PubMed1998

Is propranolol effective in primary polydipsia?

OBJECTIVE: Psychiatric patients presenting with polydipsia are often difficult to treat with standard psychiatric interventions. Pharmacological intervention was attempted in these patients based on the hypothesis that angiotensin II, a potent dipsinogen, may be involved in the drinking behavior of patients with polydipsia. Beta-blockers inhibit renin release (and thus indirectly angiotensin II) by blocking beta receptors in the kidney. METHODS: Three patients were identified as excessive water drinkers during their hospital admissions. All three patients were eunatremic but polydipsic at the time of study. Two of the three had histories of hyponatremia and required emergency medical treatment on more than one occasion. No patients had been controlled by strict fluid restriction. Trials of propranolol were initiated to control their water drinking. RESULTS: After starting propranolol, two patients responded quickly. In one patient, fluid intake decreased from 2650 +/- 647 to 1577 +/- 361, p < .001. In the other, fluid intake decreased from over 7000 ml before starting propranolol to around 3000 ml. The mean noon body weight of the third patient, in whom it was not possible to document fluid intake or urine volume before and after administering beta-blocker, was 72.6 +/- 2.6 Kg and 66.0 +/- 1.0 Kg, respectively (p < .0001). CONCLUSIONS: These results suggest that propranolol may be useful for the treatment of polydipsia in patients with schizophrenia. Its efficacy could be related to inhibition of the renin-angiotensin system. Additional research using the controlled pharmacotherapeutic trials is required to confirm these findings.

Adrenergic beta-Antagonists↗
PubMed1998

[Use of platelet glycoprotein IIb/IIIa receptor inhibitors in acute coronary syndrome and coronary intervention].

New strategies in the treatment of acute coronary syndromes have focused on the potential for blocking platelet aggregation through the use of platelet surface membrane glycoprotein (GP) IIb/IIIa receptor inhibitors. The benefits of GPIIb/IIIa inhibition in preventing ischemic complications of interventional treatment have been well defined in patients with unstable angina. In the future, major therapeutic applications for this class of agents may include the stabilization of patients with unstable angina and potentially as single medical therapy, as several recently completed trials have suggested. This article attempts to review recently published clinical trials regarding the use of GPIIb/IIIa receptor inhibitors, and clarify current problems in the use of this agent and directions for future investigation.

Acute Disease↗
PubMed1997

Acute vigorous exercise attenuates sensitivity of platelets to nitric oxide.

We tested whether inhibition of platelet activation by nitric oxide (NO) might be altered by strenuous exercise. Sixteen healthy male non-smokers, aged 20-26 years, underwent treadmill testing. All subjects reached Bruce stage IV without chest pain or abnormal ST-T wave changes. Platelet aggregation by Born's method and cyclic GMP accumulation in the washed platelets were determined before and immediately after exercise. Dose-response curves for platelet aggregation by collagen were constructed both in the absence and presence of 2 microM SIN-1, an NO donor, to quantify the antiaggregation effects of NO. After exercise, platelet aggregation by collagen was modestly enhanced and inhibition of platelet aggregation by SIN-1 was significantly attenuated by exercise. This attention was accompanied by a blunted cyclic GMP response of the platelets to the NO donor. We conclude that impaired sensitivity of the platelets to NO, in addition to the enhancement of platelet aggregation, may partially explain the epidemiological evidence that acute strenuous exercise precipitates coronary events.

Adult↗
PubMed1997

Impaired NO release from bovine aortic endothelial cells exposed to activated platelets.

We have previously shown that aggregated human platelets elicited a decrease in intracellular adenosine triphosphate (ATP), enhanced adenosine egress and damage to mitochondria in bovine aortic endothelial cells (ECs). To test whether such metabolic and ultrastructural changes could be associated with functional impairment of ECs, we investigated the effects of activated platelets on nitric oxide (NO) and prostacyclin release, and on the antiaggregation property of ECs. Pretreatment of ECs with aggregated platelets transiently stimulated basal NO release while prolonged (> or = 30 min) exposure dose-dependently inhibited NO release, both basal and in response to ATP or serotonin, with NO synthase activity being attenuated in these cells. Supplementary L-arginine (L-A) restored NO release completely. Prostacyclin release was also stimulated transiently but not affected by prolonged pretreatment. The antiaggregation property of ECs was attenuated by pretreatment with activated platelets but restored with L-A supplement. Although the effects of activated platelets and 0.5 mM acetylsalicylic acid (ASA) to attenuate the antiaggregation property of ECs were additive, activated platelets had no effect on ECs treated with 0.2 mM N omega-nitro-L-arginine (L-NA), suggesting a common mechanism. We conclude that prolonged exposure to aggregated platelets may affect the antiaggregation property of ECs by directly inhibiting NO synthesis, which may be normalized by L-A supplementation.

Adenosine Triphosphate↗
PubMed1997

The absence of synergism between the effects of an aldose reductase inhibitor, epalrestat, and a vasodilator, cilostazol, on the nerve conduction slowing and the myelinated fiber atrophy in streptozotocin-induced diabetic rats.

The preventive effects of combined or separate treatment for 10 weeks with an aldose reductase inhibitor, epalrestat (50 mg/kg/day), and a vasodilator, cilostazol (30 mg/kg/day), on nerve conduction deficits and morphometric alterations were examined in streptozotocin-induced diabetic rats. The average motor nerve conduction velocities (MNCV) in the tail nerve of the untreated diabetic (DM) group, the group treated with epalrestat (ES), the group treated with cilostazol (CZ), the group with both agents together (ES&CZ), and the normal control group were 34.7, 37.7, 39.3, 39.0 and 42.1 m/s, respectively. All treatments partially but significantly prevented a reduction in MNCV. The MNCV in the ES&CZ group was almost the same as in the CZ group. In a morphometric study of the sural nerve, the DM group showed a reduction in the average diameter of myelinated fiber and in occupancy (percentage of the fascicular area occupied by myelinated fibers), and a shift in the diameter-frequency histogram to smaller diameters. Only the CZ group showed evidence of a partial but significant preventive effect on the decrease in occupancy. In the CS and ES&CZ groups, there was a significant tendency away from the shift of histograms to smaller diameters. The ES&CZ group did not show any fewer morphometric changes than the CZ group. Thus, there was no synergism between the effects of epalrestat and cilostazol on the development of experimental diabetic neuropathy. This finding may provide a useful clue to the mechanisms of action of ES and CZ in diabetic neuropathy.

Aldehyde Reductase↗
PubMed1997

Access to the emergency psychiatry system in Japan.

Although the need for an emergency psychiatry system is increasing in Japan because of a shift to providing psychiatric care from hospitalization to community-based services, little attention is being given to what the general population expects from the health care system. To ascertain the expectations of the general population about how emergency psychiatric cases should be handled, the authors distributed a questionnaire to 1000 people containing 12 characteristic psychiatric emergency cases. The results showed that most expected psychiatric care to be rendered in a general hospital. This was different from the opinion held by most mental health professionals who felt that mental health hospitals should be the core hospitals of emergency psychiatry. Although there was a higher expectation for police officers or paramedics to provide emergent psychiatric care, the general population expected less from public health centers which now provide mental health service in the community. To connect emergency psychiatry with the community, the general hospital must play a larger role in the system through training programs for general hospital psychiatrists as well as nonpsychiatrist professionals, paramedics, and police officers.

Adolescent↗
PubMed1997

Isolation and characterization of invasive and noninvasive variants of a rat bladder tumor cell line.

We isolated, in vitro, spontaneous variants of the rat bladder tumor NBT-II cell line with a distinctive morphology. Of five sublines obtained, three (NBT-L1, L2a and L2b) exhibited an elongated shape and moderate to high invasive activity in vitro. The other two sublines (NBT-T1 and T2) formed tight colonies and exhibited very low or negligible invasive activity. The contents of mRNAs coding for E-cadherin and cadherin-associated molecules (alpha-catenin and beta-catenin) were not correlated with the invasive activity of the cells. However, the expression level of the E-cadherin protein, but not those of catenins, was lower in invasive cells (NBT-L1, L2a and L2b) than in noninvasive cells (NBT-T1 and T2). Analysis of mRNAs coding for several growth factors and their receptors showed that the transforming growth factor alpha mRNA content in invasive cells was higher than that in noninvasive cells, and that the content of epidermal growth factor receptor mRNA was low in NBT-T2. Although NBT-II is known to acquire a fibroblastic appearance and cell motility in response to several growth factors, the conditioned media of the invasive sublines hardly affected the morphology or motility of noninvasive cells. These results indicate that the decreased E-cadherin expression is closely associated with the transition from the noninvasive to the invasive phenotype of the bladder tumor cells, and that a post-transcriptional process is important in the control of E-cadherin expression in the cells. These sublines may be useful as models for studies on the progression of bladder tumors.

Animals↗
PubMed1997

A case of scurvy rarely encountered in Japan.

We report a case of scurvy, which is rarely encountered in Japan. A 75-year-old male was hospitalized with diffuse subcutaneous hemorrhaging of both feet, pain on walking, and shortness of breath. A remarkably low serum level of vitamin C was confirmed. Administration of ascorbic acid dramatically improved his clinical symptoms. Improvement paralleled the increase of serum vitamin C level. This case underscores the important role of vitamin C on the integrity function of the vessel wall.

Aged↗
PubMed1996

The validity of observed depression as a criteria for mood disorders in patients with acute stroke.

The validity of observed depression as a criteria for major or minor depression was assessed among 301 patients with acute stroke. Patients who acknowledged a depressed mood or loss of interest (standard depression) were compared to patients who denied depression but were 'observed' to be depressed (non-standard depression) for the clinical correlates of depression. Although standard and non-standard major depressions had some clinical correlates such as increased frequency of female gender and prior psychiatric history, standard major depression patients had a significantly higher frequency of left hemisphere lesions than the non-standard major depression patients. These results support the validity of 'observed' depression as a criteria for major depression but also suggest the possibility that failure to report depressed mood may identify a condition with a different etiology than depression that is recognized and acknowledged. Observed depression, however, was not validated among patients with minor depression since there were no clinical or phenomenological differences from non-depression.

Activities of Daily Living↗
PubMed1996

Genomic diversity of mec regulator genes in methicillin-resistant Staphylococcus aureus and Staphylococcus epidermidis.

Low-affinity penicillin-binding protein PBP-2a encoded by mecA is closely related to methicillin resistance in staphylococci, and expression of PBP-2a is controlled by regulator elements encoded by mecR1 and mecI which are located adjacent to mecA on the chromosome. Deletion or mutation which occurred in mec regulator gene is considered to be associated with constitutive production of PBP-2a. The distribution of the mec regulator genes in 176 strains of Staphylococcus aureus and 33 strains of S. epidermidis isolated from a single hospital was studied by polymerase chain reaction amplification. Most clinical isolates of methicillin-resistant S. aureus (MRSA) (94.3%) and S. epidermidis (MRSE) (83.9%) possessed both mecI and mecR1 genes (type I), whereas no mec regulator genes were detected in mecA-negative isolates. In contrast, 7 MRSA and 5 MRSE isolates were found to have incomplete regulator genes, and they were classified into three groups; strains which lacked only mecI gene (type II), strains which lacked mecI and 3'-end of mecR1 gene (type III), and strains which lacked both regulator genes (type IV). Analysis of mecI gene from all the strains having mecI by restriction fragment length polymorphism after Mse I digestion indicated that three MRSA strains possessed one of the known point mutations identified previously. These findings indicated the predominance of a single type of MRSA possessing both mecI and mecR1 in the study period and also suggested a high genomic diversity in mec regulator region of staphylococci.

Cross Infection↗
PubMed1996

Suicidal plans in patients with stroke: comparison between acute-onset and delayed-onset suicidal plans.

Three hundred one patients were examined for suicidal plans during the acute hospital period following stroke and at 3, 6, 12, and 24 months' follow-up. It was found that 6.6% of patients developed suicidal plans during the initial in-hospital evaluation (acute-onset suicidal plans) and 11.3% of patients developed suicidal plans at 3, 6, 12, or 24 months' follow-up (delayed-onset suicidal plans). The development of both acute and delayed-onset suicidal plans was strongly related to the existence of depressive disorders, especially major depression, and to a prior history of stroke. Acute-onset suicidal plans were also related to premorbid alcohol abuse. Acute-onset suicidal patients had more anterior lesion location and delayed-onset suicidal patients had more posterior stroke lesions. Delayed-onset suicidal plans were not related to alcohol abuse but tended to be associated with greater physical impairment and poorer social support during the acute poststroke period. These data suggest that the etiology of these two types of suicidal plans may be different with acute onset related to biological mechanisms and delayed onset related to psychological mechanisms.

Acute Disease↗
PubMed1996

Effect of probucol, an oral hypocholesterolaemic agent, on acute tobacco smoke inhalation in rats.

1. We hypothesized that probucol, an oral hypocholesterolaemic agent, can suppress the oxidant stress induced by acute tobacco smoke inhalation in rats. We determined lung tissue glutathione (reduced and oxidized), lipid peroxide, tocopherol and plasma elastase inhibitory capacity, ferroxidase activity and lipid peroxide in rats after inhalation of tobacco smoke. 2. Rats treated with the probucol diet for 3 days or 4 weeks equally showed no suppression of plasma elastase inhibitory capacity and ferroxidase activity compared with control rats after acute tobacco smoke inhalation, although both animals treated with probucol for 3 days or 4 weeks had pharmacologically effective concentrations of probucol to lower plasma cholesterol but plasma cholesterol in rats treated with probucol for 3 days was still in the normal range. 3. Probucol treatment for 4 weeks lessened tobacco smoke-induced suppression of lung tissue glutathione, attenuated tobacco smoke-induced increases in lung tissue lipid peroxide and did not alter lung tissue tocopherol compared with control (lungs). 4. These findings demonstrate that probucol, via its antioxidant ability, confers a protective effect on lung exposed to acute tobacco smoke inhalation.

Animals↗
PubMed1996

Suicidal plans in patients with acute stroke.

The clinical correlates of suicidal thoughts were examined among a group of 301 patients with acute stroke. A total of 20 patients (6.6%) had suicidal thoughts. Previous history of stroke was associated with suicidal thoughts. Suicidal thoughts, however, were not related to severity of physical impairment. Most patients with suicidal thoughts met criteria for major depression. Other risk factors included younger age, poor social support, sensory deficit, and impaired cognitive function. Patients with suicidal plans had depression characterized by social withdrawal and brooding and self blame. Early identification of risk factors including the existence of depression may lead to effective therapeutic intervention.

Acute Disease↗
PubMed1996

Comparison of effects of vasoactive agents on adenylate cyclase activity in endothelial and smooth muscle cells from the same specimen of fetal bovine aorta.

1. Adenylate cyclase activity in vascular endothelial cells (EC) has not been adequately defined. We compared adenylate cyclase activities in EC and smooth muscle cells (SMC) from the same specimen of fetal bovine aorta. 2. The basal adenylate cyclase activities of EC and SMC did not differ significantly (18.9 +/- 0.8 and 21.4 +/- 1.7 pmol/mg protein per min, n = 10, respectively). 3. The adenylate cyclase of EC responded dramatically to catecholamines, with the ED50 value for isoproterenol being 0.036 mu mol/L, and was also more sensitive to calcitonin gene-related peptide than that of SMC. 4. The adenylate cyclase of SMC was more sensitive to prostaglandins (with the ED50 for PGI2 being 0.024 mu mol/L) and glucagon than that of EC, and responded modestly to catecholamines and was almost selectively sensitive to beta1-adrenoceptor agonists. 5. Maximum responses of adenylate cyclase to F-, guanosine 5'-o-(3-thiotriphosphate) and forskolin were greater in SMC than in EC. 6. Based on these findings, it was concluded that EC and SMC differed significantly in adenylate cyclase responsiveness to agonists including hormones, prostaglandins, peptides and substances which may modify the effects of G proteins, although they shared a common developmental origin. Presumably, beta-adrenoceptor agonists in EC and prostaglandins in SMC may appear to play an important role in cellular functions which are mediated by increases in cAMP.

Adenine↗
PubMed1996

Suicidal plans following spinal cord injury: a six month study.

Suicidal plans were examined among patients with spinal cord injury. Suicidal plans during the acute period may be related to inadequacy of support. Suicidal plans during the chronic period may be related to a depressive disorder provoked by prolonged severe impairment.

Adult↗
PubMed1996

Takayasu arteritis: clinical characteristics and the role of genetic factors in its pathogenesis.

Takayasu arteritis is a chronic vasculitis, the aetiology of which is still unknown. Several characteristic clinical manifestations have led scientists to consider the possibility of the genetic factors in the aetiology, conjecture which is supported by HLA analysis. Recent attention has focused on the different clinical manifestations among Asian and South American countries and further progress is likely to stem from international network studies.

Adult↗