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Biomedical subjects

T Kaku

Publications and source records attributed to T Kaku.

At least 19 recordsLinked to original sources
PubMed1995

Increased susceptibility of angiographically smooth left anterior descending coronary artery to an impairment of vasoresponse to acetylcholine, and the relation between impaired vasoresponse and low-density lipoprotein cholesterol level.

In the present study, we demonstrated that the angiographically smooth LAD is more susceptible than the LC to an impairment of vasoresponse to acetylcholine, suggesting the more severe endothelial dysfunction in the LAD. We also showed that levels of LDL play a partial but important role on endothelial dysfunction.

Acetylcholine↗
PubMed1995

Novel ligand binding properties of the myoglobin substituted with monoazahemin.

The iron complex of alpha-azamesoporphyrin XIII was combined with apomyoglobin to investigate influence of the meso nitrogen on ligand binding properties in the reconstituted protein. Stoichiometric complex formation between the two components was confirmed, and conservation of the native coordination structures in the resultant myoglobin was established with spectroscopic criteria and apparently normal ligand binding. The visible absorption spectra of various ferric and ferrous derivatives are characteristic with less intense Soret peaks and enhanced visible bands. The electron paramagnetic resonance spectrum with g = 5.2 suggests an anomalous intermediate spin (S = 3/2) character for the aquomet protein. The oxygen affinity of reduced azaheme myoglobin, 0.010 mm Hg, is 50 times larger than that of the native myoglobin. In addition, azaheme myoglobin forms stable complexes with imidazole, pyridine, or cyanide in ferrous state. All of these new properties were consistently explained in terms of stronger equatorial ligand field of the heme iron in a narrower coordination cavity. Similarities of azaheme to verdoheme were also pointed out.

Carbon Dioxide↗
PubMed1995

The prognostic significance of lymphovascular space invasion in endometrial cancer when conventional hemotoxylin and eosin staining is compared to immunohistochemical staining.

The current study was undertaken to compare the usefulness of hemotoxylin and eosin (H&E) staining and immunohistochemical staining to identify lymphovascular space invasion (LVSI) in endometrial cancer and to evaluate the presence of LVSI detected by either technique as an independent prognostic factor. Histologic sections from 92 patients with clinical stage I-II endometrial cancer were reviewed, and representative sections were stained immunohistochemically with antibodies for von Willebrand factor and blood group isoantigens. To compare the prognostic significance of LVSI detected by H&E staining with that detected by immunohistochemical staining, univariate and multivariate analyses were performed. Thirty (32.6%) of the 92 cases showed LVSI in H&E staining. In 8 of the 30 cases, LVSI was negative by immunohistochemical staining, while LVSI was positive by immunohistochemical stainings in 2 of 62 cases showing negative LVSI in H&E staining. In univariate analysis, LVSI detected by H&E and immunohistochemical staining was proved to be significant as a prognostic factor. In multivariate analysis by Cox's proportional hazards model, LVSI identified by H&E staining was selected as one of significant prognostic factors, but LVSI identified by immunohistochemical staining not selected. The results of this study indicate that LVSI is one of the independent prognostic factors in endometrial cancer, and that LVSI as detected by H&E is more prognostic of survival than immunohistochemical detection.

Adult↗
PubMed1994

Endogenous adenosine exerts inhibitory effects upon the development of spreading depression and glutamate release induced by microdialysis with high K+ in rat hippocampus.

Spreading depression (SD) is known to be involved in the N-methyl-D-aspartate receptor-mediated neuronal damage. In urethane-anesthetized rats, we examined the release of adenosine and glutamate during SD induced by microdialysis of high K+ perfusate through the hippocampal CA1 area. The effects of endogenous adenosine upon SD were studied by applying an adenosine antagonist, theophylline (1 mM) and by a simultaneous application of adenosine uptake blockers, dipyridamole (DPR) (100 microM) and nitrobenzylthioinosine (NBI) (50 microM). The dialysates were sampled every 5 or 10 min and analyzed by HPLC. SD was identified by flattening of background EEg and disappearance of population spikes recorded from the pyramidal cell layer of CA1 area by a glass microelectrode. Adenosine and glutamate release was enhanced significantly in association with the occurrence of SD. Theophylline increased the release of glutamate and the incidence of SD and decreased the latency of the SD occurrence. DPR+NBI decreased the release of glutamate and the occurrence of SD, but increased extracellular adenosine concentration. The effects of DPR+NBI were blocked by application of a selective antagonist of adenosine A1 receptor, 8-cyclopentyl-1,3-dipropylxanthine (DPCPX, 0.1 microM). These findings suggest that endogenous adenosine exerts inhibitory influences upon the development of SD and the glutamate release through the A1 receptor in rat hippocampus.

Adenosine↗
PubMed1992

Mutual recognition between polymerized liposomes. IV. Polysaccharide-lectin system.

As a model of cell-cell recognition processes, the association processes of a polysaccharide (mannan)-carrying liposome with a lectin (Concanavalin A, Con A)-carrying polymerized liposome were followed by turbidimetry. The association process was strongly inhibited by the addition of a low molecular weight sugar, methyl-alpha-D-mannopyranoside, which shows that the association between the liposomes is due to the specific interaction between Con A and mannan. The association rate constant obtained was much smaller than the theoretical value for a diffusion-controlled binary association process. This implies that the association rate of liposomes is limited by the recognition between complementary ligands bound on the liposome surfaces. Another reason for the smaller association rate constant in the liposome-liposome system is the repulsive hydration effect. The effect of the surface density of the lectin immobilized on the liposome on the recognition was also examined.

Concanavalin A↗
PubMed1992

Microcarcinoma of the endometrium: a mapping study with special reference to cytologic atypia in the endometrium.

In order to elucidate the basis for the development of an endometrial carcinoma, we looked for microcarcinomas measuring < 5 mm in greatest diameter, and studied their histologic characteristics and those of the neighboring endometrium. Using serial step section methods, two microcarcinomas were detected. A microcarcinoma was found in one of 14 uteri resected for atypical hyperplasia and the other was found in one of 114 uteri resected for endometrial carcinoma. The neighboring endometrium of the former was adenomatous and had atypical hyperplasia and that of the latter was atrophic and contained atypical glands characterized by cytologic atypia and not by architectural changes. The findings may suggest endometrial carcinomas to have two pathogenetic forms: a carcinoma associated with hyperplasia and occurring in premenopausal women, a second carcinoma associated with atrophic endometrium and occurring in postmenopausal women. Atypical glands in atrophic endometria may indicate that endometrial specimens from postmenopausal women should be carefully screened for cytologic atypia.

Adenocarcinoma↗
PubMed1992

Adenosarcoma of the uterus: a Gynecologic Oncology Group clinicopathologic study of 31 cases.

We report on the clinical and pathologic findings in 31 cases of adenosarcoma of the uterus subjected to hysterectomy and staging laparotomy. Nine of 30 patients (30%) have had recurrent tumor and six of 30 (20%) have already died of tumor in a relatively short follow-up period (mean, 38.3 months). Seventeen of 31 cases were diagnosed as adenosarcoma with sarcomatous overgrowth (SO). Ten of these 17 with SO contained focal or extensive rhabdomyosarcoma. In six cases, extrauterine spread was identified as follows (two patients had two sites each): vaginal involvement (two cases), pelvic lymph node metastases (two), positive peritoneal cytologic findings (two), parametrial invasion (one), and ovarian metastasis (one). Extrauterine spread (stage III) (p less than 0.001) and myometrial invasion (p = 0.04) were associated with higher rates of recurrence. The presence of lymphatic and/or vascular invasion, SO, and rhabdomyosarcomatous differentiation also indicated poor prognosis but did not attain statistical significance. Based on this experience, staging laparotomy including peritoneal cytology is suggested in cases of clinical stages I and II adenosarcoma. The differential diagnosis of these tumors is also discussed.

Adult↗
PubMed1992

[Visuo-postural control of schizophrenics--variations of sway area during horizontal eye movement].

In the present study, we investigated the neurological mechanism of commonly known specific or unnatural postures in schizophrenic patients. Using a gravimeter, body sway studied in 26 chronic schizophrenic patients, 10 schizoaffective disorder patients and 21 normal subjects. During eye fixation at a target while keeping an upright posture, schizophrenic patients presented a larger gravimetric area than the normal subjects and the patients with schizoaffective disorder. There was a negative correlation (r = -0.509) between the standard deviation of the sway gravimetric area during fixation and the dose of neuroleptics in schizophrenic patients, but no correlation was found in patients with schizoaffective disorder (r = -0.01), although they took neuroleptics in a similar regimen to that for the schizophrenics. There was no correlation between the standard deviation of the sway gravimetric area during fixation and the duration of illness. There was also no correlation between the former and the amplitude ratio of saccades during smooth pursuit eye movements. When horizontal eye movements pursuing the target were loaded in this experiment, both the normal subjects and the patients with schizoaffective disorder showed a decrease in a loaded gravimetric area and a tendency towards postural stabilization. However, schizophrenic patients having higher SANS scores (Andreasen) presented an increase in gravimetric area. This suggests that schizophrenic patients with higher SANS score may have organic cerebellar changes related to impairment of the mechanism of visual and postural coordinations.

Adult↗
PubMed1992

Endometrial metaplasia associated with endometrial carcinoma.

OBJECTIVE: To clarify the relationship of metaplasia to endometrial carcinoma. METHODS: Between 1984-1990, 73 cases of stage I-II endometrial carcinoma treated initially by hysterectomy were reviewed histologically. The metaplasias were classified as squamous, syncytial papillary, ciliated-cell, eosinophilic, mucinous, clear-cell, or hobnail. We assessed the histologic type and grade of the carcinoma, depth of myometrial invasion, presence or absence of lymph-vascular space invasion, and presence or absence of lymph node metastases. RESULTS: Forty of 73 patients (55%) had one or more areas of metaplasia in the endometrium adjacent to the carcinoma. Ciliated-cell metaplasia (28 of 73; 38%) was the most common type encountered. Women with both endometrial carcinoma and metaplasia were significantly younger than those with carcinoma without metaplasia (P < .05). Compared with carcinomas without metaplasia, those with metaplasia were well differentiated (P < .01) and lacked myometrial invasion (P < .01) and pelvic lymph node metastases (P < .05). The presence of metaplasia was also significantly correlated with the presence of endometrial hyperplasia (P < .01). CONCLUSION: In endometrial carcinomas, the presence of endometrial metaplasia suggests a favorable prognosis.

Adult↗
PubMed1991

Microscopic ovarian metastasis of the uterine cervical cancer.

Six hundred forty-seven cases of carcinoma of the uterine cervix with FIGO stages Ib or more were initially treated with hysterectomy at Kyushu University Hospital from 1973 to 1987. In these, 597 cases could be pathologically reviewed for ovarian metastasis. In these 597 cases, 335 were stage Ib, 71 IIa, 185 IIb, and 6 IIIb. Only 3 (0.5%) of 597 showed ovarian metastasis. All 3 cases were stage IIb. None of stage Ib cancer cases had ovarian metastasis. One (0.19%) of 524 squamous cell carcinomas metastasized to the ovary, whereas 2 (5.5%) of 36 pure adenocarcinomas revealed ovarian metastasis. Interestingly, all ovarian metastatic lesions were microscopic in size and found in the ovarian hilus. As for the primary lesion, all cases with ovarian metastasis showed deep myometrial invasion, corpus invasion, and lymphatic permeation. Two cases showed pelvic lymph node metastases and positive peritoneal washing cytology. From the results of our study, it can be said that it is fairly safe to preserve the ovary at the time of radical operation in squamous cell carcinoma of the uterine cervix, but it may not be safe to preserve the ovary in pure adenocarcinoma of the uterine cervix.

Adenocarcinoma↗
PubMed1991

Reflection as a cause of mid-systolic deceleration of pulmonary flow wave in dogs with acute pulmonary hypertension: comparison of pulmonary artery constriction with pulmonary embolisation.

STUDY OBJECTIVE: The aim was to examine whether mid-systolic deceleration of the pulmonary flow wave occurred in acute pulmonary hypertension due to pulmonary artery constriction and pulmonary embolisation, and if so whether it was related to reflection. DESIGN: Various degrees of pulmonary hypertension were induced by both pulmonary artery constriction and pulmonary embolisation in dogs. During control periods and during pulmonary artery constriction and pulmonary embolisation, pulmonary flow and pulmonary artery pressure were recorded, and the forward and backward (reflected) flow waves were separated from the measured pulmonary flow wave by the method of Westerhof et al. MATERIALS: 20 adult mongrel dogs were used and 10 dogs qualified for analysis. The other 10 dogs, which died before both interventions were completed, were excluded. MEASUREMENTS AND MAIN RESULTS: During pulmonary artery constriction, a distinct mid-systolic deceleration of the pulmonary flow wave was observed in five of the 10 dogs, while during pulmonary embolisation, no mid-systolic deceleration was found in these five dogs. The distinct deceleration of the pulmonary flow wave was related to a steep fall and early negative peak in the backward flow wave. CONCLUSION: Mid-systolic deceleration of pulmonary flow wave is likely to be related to reflection.

Acute Disease↗
PubMed1991

Alpha-adrenergic regulation of phosphoinositide metabolism and protein kinase C in isolated cardiac myocytes.

alpha 1-Adrenergic regulation of phosphoinositide metabolism and protein kinase C translocation was studied in isolated rat cardiac myocytes. Exposure of [3H]inositol-labeled myocytes to norepinephrine in the presence of propranolol caused a dose-dependent increase in [3H]inositol phosphates. Norepinephrine also increased the level of membrane-associated protein kinase C from approximately 10% of total activity to 18%, with a dose response similar to that for generation of inositol phosphates. Depolarization of myocytes with 30 mM KCl had no effect on inositol phosphates or membrane-associated protein kinase C but potentiated the effect of submaximal norepinephrine on both parameters. The potentiation of protein kinase C translocation was amplified when extracellular Ca2+ was increased to 4 mM, resulting in membrane association of one-third of the total cellular activity. These data show that activation of protein kinase C occurs during alpha 1-adrenergic stimulation of cardiac myocytes and that elevation of intracellular Ca2+ amplifies this effect at least in part through increased phosphoinositide metabolism.

Animals↗
PubMed1991

Changes in sodium-22 turnover and total body potassium in two-kidney, one-clip renovascular hypertension.

Changes in sodium-22 turnover and total body potassium (TBK) were studied during acute (within 2 weeks after clipping) and chronic (12-14 weeks after clipping) phases in two-kidney, one-clip (2k, 1c) hypertensive rabbits by using a whole body counter. Sodium-22 injected intravenously was eliminated more rapidly in hypertensive rabbits than in controls. The biological half-life (BHL) of sodium-22 was shorter in hypertensive rabbits during both acute (p less than 0.05) and chronic phases (p less than 0.001). A significant negative correlation was obtained between the BHL of sodium-22 and blood pressure (r = -0.588, p less than 0.05) in hypertensive rabbits. TBK decreased significantly at the chronic phase in hypertensive rabbits (p less than 0.05), while TBK showed no significant change in controls. Serum sodium and potassium did not change during the observation period. Increased plasma aldosterone concentration was observed during the acute phase in hypertensive rabbits. These results suggested that sodium retention was not a major factor in the acute and chronic phases of 2k, 1c hypertension in rabbits and that pressure natriuresis could explain, at least in part, the lack of sodium retention. Furthermore, there appears to be a derangement in the intracellular potassium metabolism which may be associated with the maintenance rather than the development of hypertension.

Aldosterone↗
PubMed1991

Ruptured chordae tendineae in acromegaly. An autopsy case.

A 57-year-old woman with acromegaly associated with mitral chordal rupture is reported. She was noted to have abnormal development in the size of her hands and feet in childhood. She occasionally suffered from shortness of breath on exertion and nocturnal dyspnea for several years, and was diagnosed and treated as having congestive heart failure due to valvular heart disease. On admission to our hospital, chordal rupture was suspected on the basis of M-mode and two-dimensional echocardiography. Seven years after discharge, she died of congestive heart failure. On autopsy, the heart weight and ventricular wall thickness were increased. Rupture of the posterior chordae was confirmed, but evidence of an old myocardial infarction was not found. There was severe interstitial fibrosis in the left ventricular wall. A possible etiology of the chordal rupture in this case was thought to be the excessive stretching caused by the disproportional visceromegaly of the heart.

Acromegaly↗
PubMed1991

[Dry cough in the elderly patients treated with angiotensin converting enzyme inhibitor].

Since dry cough has recently been recognized as a side effect of angiotensin converting enzyme (ACE) inhibitors employed in the treatment of hypertension or congestive heart failure, the incidence of dry cough in elderly patients receiving ACE inhibitors was investigated. There were 237 out-patients on either captopril, enalapril, or delapril, in August and November 1989. Questionnaires concerning dry cough and smoking were completed by 184 patients. Patients either less than 50 years of age, or with chronic pulmonary disease were excluded. The remaining 168 patients, 63 males, 105 females, with a mean age of 73 years were analyzed for the incidence of a dry cough in relation to age, sex, smoking, and type of drugs. The overall incidence of a dry cough was 21/168 (12.5%), 7/63 (11.1%) for males and 14/105 (13.3%) for females, and was less frequent with advancing age; in the 51-60 age group 4/11 (36.4%), in the 61-70 age group 5/39 (12.8%), in the 71-80 age group 9/75 (12.0%), in the 81-90 age group 3/40 (7.5%), in the 91- age group 0/3 (0%). Enalapril showed significantly higher incidence of dry cough than captopril (16/93, 17.2% vs 7/88, 8.0%, p less than 0.05). Delapril showed an incidence 4/11, 36.4%, however, 9 out of the 11 patients who were given delapril had had a history of a dry cough with captopril or enalapril, and in 4 out of these 9 patients the dry cough disappeared by replacement of captopril or enalapril by delapril.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1990

Arterio-venous fistulas involving the uterus and lung.

A case of arterio-venous fistulas (AVF) involving the uterus and lungs is described. A 57-year-old Japanese woman developed profuse uterine bleeding during endometrial curettage, and underwent emergency abdominal hysterectomy. Postoperatively, she complained of exertional dyspnea and palpitation. Pulmonary angiography revealed multiple AVFs in both lungs. The surgical resections of the lung lesions were performed and her pulmonary symptoms improved.

Arteriovenous Fistula↗
PubMed1990

Efficacy of second-look laparotomy for patients with epithelial ovarian carcinoma.

Second-look laparotomies (SLL) were performed on 42 patients with ovarian carcinoma. Ten (24%) had residual disease. Serum CA 125 values before SLL predicted the presence of residual tumors, but its relatively high false negative rate made it unable to take place of SLL. Positive peritoneal cytology at initial surgery significantly influenced SLL results in patients with early disease. Residual pelvic lesions at initial surgery seemed to resist subsequent chemotherapy. Salvage therapy with external pelvic irradiation was effective on lesions confined to the pelvis without serious toxicity. Patients with advanced disease, undergoing SLL achieved better survival than without SLL. This study shows SLL is still the most accurate procedure in assessing the efficacy of treatment, and useful in selecting second-line therapy.

Adult↗