Biomedical subjects

Y Ohta

Publications and source records attributed to Y Ohta.

At least 685 records · Page 38Linked to original sources

PubMed1991

Predicting histologic findings from endoscopic appearance of early gastric cancer.

In 156 cases of depressed early gastric cancer in the antrum or corpus, the differences between differentiated and undifferentiated carcinoma were studied by comparing the histological diagnosis of the resected specimens and their endoscopic appearance. We reached the following conclusions: (a) Younger patients more often had undifferentiated carcinoma (mean age: 59.8 years) than differentiated carcinoma (mean age: 77.2 years). (b) One hundred and twenty-five of 156 cases were limited to the mucosa and 29 cases were limited to the submucosa. (c) Undifferentiated gastric cancers more often invaded beyond the mucosa even when the tumor was small than did differentiated tumors. (d) Many differentiated tumors showed a smooth depressed surface, erythema at the edge of the cancer, and tapering of the gastric rugae. (e) In undifferentiated lesions the depressed tumor surface had a varied appearance, with various sized granules and nodules, as well as fading of the mucosal color and fusion of the rugae. It is important at endoscopy to consider not only whether a lesion is benign or a malignant, but also to consider its histological type. In particular, it is vital to detect small, undifferentiated gastric cancers as early as possible.

Adenocarcinoma↗

PubMed1991

Decision making in clinically depressed patients. A transcultural social psychological study.

One of the most important cognitive deficits in depression is said to be the patient's inability to make decisions. A research design involving a cross-cultural comparison between Australian and Japanese normal controls (N = 309 and N = 743, respectively) and clinically depressed patients (N = 59 and N = 45, respectively) was used to examine the influence of culture on illness and decision-making behavior, and whether deficits in decision making may be related to culture. It was found that depression had a greater effect on decision making in Australian patients than in Japanese patients. While many differences were found between Australian and Japanese nondepressed students, few differences were found between Australian and Japanese depressed patients. Thus, there appears to be an important interactional effect of culture and depression on decision making. The theoretical and clinical implications of the results are discussed.

Adolescent↗

PubMed1991

Chronic effects of metoprolol on myocardial beta-adrenergic receptors in doxorubicin-induced cardiac damage in rats.

This study was designed to clarify whether chronic administration of metoprolol had any influence on cardiac beta-adrenergic receptors (BAR) in doxorubicin (DOX)-induced cardiac damage. DOX was injected through the tail vein into rats (3 mg/kg/week, n = 22) for 5 weeks. One week after the final injection, the rats were randomly divided into two groups, M (with metoprolol, 10 mg/kg/day subcutaneously, s.c.; n = 11) and D (without metoprolol; n = 11). After 3-week infusion, plasma norepinephrine (NE) levels and BAR density [[125I]iodocyanopindolol (ICYP) binding on crude membranes] were measured. Left and right ventricular end-diastolic pressure (LVEDP, RVEDP) and myocardial NE levels were also measured, and the results were compared with those from an age-matched control group (C n = 11). Decreased BAR density and increased plasma NE levels were evident in group D, indicating downregulation. In group M, BAR density and plasma NE levels were similar to those in group C. The myocardial NE levels were decreased in group D, but were higher in group M than in group D. The LVEDP and RVEDP were increased in group D, but were almost normal in group M. These results suggest that metoprolol is a promising drug for treatment of DOX-induced cardiac damage.

Animals↗

PubMed1991

Pro-peptide as an intramolecular chaperone: renaturation of denatured subtilisin E with a synthetic pro-peptide [corrected].

The amino-terminal pro-sequence consisting of 77 amino acid residues is required to guide the folding of secreted subtilisin E, a serine protease, into active, mature enzyme (ikemura et al., 1987). Furthermore, denatured subtilisin E can be folded to active enzyme in an intermolecular process with the aid of an exogenously added pro-subtilisin E, the active site of which was mutated (Zhu et al., 1989). In this report, we have synthesized the pro-peptide of 77 residues (corresponding to -1 to -77 in the sequence, where residue +1 is the N-terminal amino acid residue of the mature protein), and have found that it could intermolecularly complement the folding of denatured subtilisin E to active enzyme. Furthermore, we have found that the synthetic pro-peptide exhibits specific strong binding to the active mature enzyme by inhibiting it competitively at its active centre with an upper limit to a Ki of 5.4 x 10(-7). In contrast, synthetic pro-peptides corresponding to -44 to -77, -1 to -64 and -1 to -43 inhibited the enzyme with Ki values weaker by two orders of magnitude. The results indicate that the sequence extending from -1 to -77 is essential for specificity of interaction, perhaps generating a conformation that accounts for both roles found hitherto, i.e. specific binding to the active centre, and guiding of the refolding to active enzyme. Thus these results suggest that the pro-peptide functions as an intramolecular chaperone [corrected].

Chaperonins↗

PubMed1991

Problems of subject inclusion in psychiatric research: observations from research with psychiatric inpatients.

In a recent study of psychiatric disturbance and decision making behaviour, it was observed that a significant number of psychiatric inpatients experienced difficulties in addressing themselves to the experimental tasks at hand. Despite the large number of studies that have used psychiatric inpatients as subjects, little, if any mention has been made of these difficulties. The following report describes the difficulties that have been observed in the above research project, and examines their possible implications for clinical assessment, research, and for clinical investigations and evaluation of treatment regimes (e.g. effectiveness of particular drug therapies), which use psychiatric inpatient populations as subject sources.

Adolescent↗

PubMed1991

Types and characteristics of short-term course of depression after delivery: using Zung's Self-Rating Depression Scale.

In order to clarify the prevalence and clinical features of so-called "maternity blues" and the relationship with depression after delivery, we conducted a prospective study on 220 mothers using the Zung's Self-Rating Depression Scale (ZSDS) 4-7 days after childbirth and again one month after childbirth. Their physical condition during their pregnancy had been evaluated earlier. As in a previous epidemiological study conducted in Japan, we classified subjects with a ZSDS score of 60 and over as a high scoring group. Eighteen mothers (8.18%) fell into this group ("maternity blues" group) in the one week post-partum evaluation. Comparing the ZSDS scores one month after childbirth with the earlier scores, in 10 women (4.5%), their scores decreased from 60 and over to below 60 (a "maternity blues" core group), and in 8 women (3.6%), their scores were still over 60 (a prolonged "maternity blues" group). Eleven (5.0%) out of the 202 women whose scores at one week after childbirth were below 60 showed a high score (60 and over) one month after childbirth (a potential depression group). All in, 191 women scored below 60 in both evaluations. Although we could divide the subjects into 4 groups as described above, we could not find any clinical symptoms to distinguish between the 3 groups with "maternity blues" or depression in the evaluation one week after childbirth. However, one finding suggests that these three groups may have different features.

Adult↗

PubMed1991

Symptoms and social adjustment of schizophrenic patients as evaluated by their family members: a cross-cultural psychiatric study between offshore islands and an urban city.

We conducted a comparative study of symptoms and social adjustment of schizophrenic patients on offshore islands and one urban region in Japan. In the evaluation of symptoms and social behavior by family members, no differences were observed between the two regions. Looking at social adjustment in the two regions, no differences were observed by family members either in the performance level or in the expectation level of socially expected activities. However, on the offshore islands, the expectation level of socially expected activities by family members was significantly higher than the level of self-accomplishment set by schizophrenic patients themselves. As for leisure activities, both family members and patients on the islands evaluated the level of performance to be significantly higher than in the urban region, and the level of satisfaction of the patients themselves was also higher on the islands. Considering both these findings and Japanese traditional views of work and leisure, it is believed that on the islands patients are required to engage in more productive activities and less leisure activities than in the urban region. Further it seems that patients on the islands compared to patients in the urban region may have greater difficulty in social adjustment.

Adult↗

PubMed1991

Comparative study of affective disorders in three Asian countries. II. Differences in prevalence rates and symptom presentation.

This study used standardized diagnostic criteria and method to investigate both prevalence rates and nature of symptoms of depressive disorders in three Asian centres--Nagasaki, Shanghai and Seoul. Of the patients who visited a psychiatric clinic in each of the 3 centres for the first time, over 20% suffered from depression. Unlike previous reported prevalence rates for Asian countries, these results suggest that rates in Asia may not be much lower than those reported in Western countries. Although prevalence rates of depression were similar in all 3 centres, differences in symptoms were noted.

Adolescent↗

PubMed1991

Ruffle formation in the evaluation of stimulatory state of hepatic macrophages in rats.

Morphological changes in hepatic macrophages after stimulation were observed with a transmission electron microscope in rats. In the normal liver ruffle formation occupied less than 30% of the cell surface facing the sinusoidal space in 21 of 25 macrophages. When the rats received a dose of carbon tetrachloride, hepatic macrophages 1 day later showed ruffle formation to the same extent as in normal rats. In contrast, in rats 6 days after a dose of Corynebacterium parvum, ruffle formation was intensified, and in 19 of 25 macrophages it was seen to occupy more than 30% of the cell surface (p less than 0.01); 9 of 10 macrophages with more than 70% of the cell surface affected belonged to these rats. Considering that hepatic macrophages at 1 or 6 days after treatment with carbon tetrachloride or Corynebacterium parvum are at the responsive or primed stages, respectively, measurement of the extent of ruffle formation in hepatic macrophages with a transmission electron microscope may provide a useful tool in estimating their stimulatory stage.

Animals↗

PubMed1991

Evidence for enhanced secretory function of hepatic macrophages after long-term ethanol feeding in rats.

Rats were pair-fed nutritionally adequate liquid diets, containing ethanol as 36% of energy or an isocaloric amount of carbohydrate for 4-6 weeks. Ruffle formation of hepatic macrophages in the periportal area observed with a transmission electron microscope (which reflects their extent in activation) was more remarkable in ethanol-fed rats than in control rats. The ability of hepatic macrophages to produce superoxide anions assessed in situ by formazan deposition after liver perfusion with nitro-blue tetrazolium and phorbol myristate acetate was enhanced after such ethanol feeding. A similar result was seen 24 h after withdrawal of ethanol feeding. These findings suggest that long-term ethanol consumption may activate hepatic macrophages in secretory function.

Animals↗

PubMed1991

Some cytotoxicological aspects of ethyl and fluoroethyl alkanesulfonates in Escherichia coli: role of fluorine substitution.

Several fluoroethyl derivatives of alkanesulfonates and N-nitrosourea were tested for cytotoxicity and mutagenicity in E. coli K12 AB1157. Cytotoxicity was potentiated by fluorine substitution in the alkyl moiety of the ethylating agents. Mutagenicity was strongly suppressed by fluorine substitution in the alkanesulfonates, but not in the N-nitrosourea. The capacity to induce the SOS repair network was suppressed, as was mutagenicity, in alkanesulfonates, but not in N-nitrosourea. The potentiating effect of fluorine on the cytotoxicity of alkanesulfonates seems to be due to an as yet unknown killing mechanism. An appreciable suppressive effect on the mutagenicity and the SOS induction is worth notice for the biological role of fluorine substitution in alkylating agents.

Alkylating Agents↗

PubMed1991

[Regulation of Ca2+/calmodulin-dependent protein kinase II in the cell systems in response to cellular stimuli].

Calcium ion (Ca2+) is considered to be involved in the regulation of numerous cellular processes. CaM kinase II is present at the highest concentration in the brain and is considered to be involved in the regulation and coordination of numerous cellular processes. CaM kinase II is activated by Ca2+/calmodulin and simultaneously undergoes autophosphorylation. It has not been determined whether the enzyme is activated in the cell systems in response to the increase in cytoplasmic Ca2+ concentration. We have studied CaM kinase II in several kinds of cells including the primary cultures of cerebellar granule cells and the cell lines of rat embryo fibroblast 3Y1 cells, neuroblastoma cells, PC12 cells and C6 glioma cells. The immunohistochemical analysis demonstrated the presence of CaM kinase II in all of the cells examined. Furthermore, the kinase in cerebellar granule cells was activated by the stimulation of the glutamic acid receptor. Autophosphorylation of CaM kinase II in 3Y1 cells was stimulated by the addition of growth factors. These results suggest that CaM kinase II undergoes activation and autophosphorylation in response to various stimuli to the cells and is regulated in the dynamic state.

Amino Acid Sequence↗

PubMed1991

Serum levels and thyroid tissue expression of CA50 and CA 19-9 in patients with thyroid tumor.

A 77-year-old man was admitted to the hospital with a thyroid nodule. The levels of serum tumor-associated carbohydrate antigens (CA 50, CA 19-9) and thyroglobulin (HTG) were markedly increased. We performed total thyroidectomy and right neck lymph node dissection. After treatment, the serum CA 50, CA 19-9 and HTG levels were markedly decreased. Histological examination of the thyroid tumor showed papillary adenocarcinoma and the dissected neck lymph nodes contained metastatic adenocarcinoma. The expression of CA 50 and CA 19-9 (defined by the monoclonal antibodies) was studied by immunoperoxidase staining from the normal and carcinomatous thyroid tissues and the dissected neck lymph node. CA 50 was expressed more strongly by the carcinoma cells than CA 19-9. The positive rates for serum CA 50 and CA 19-9 levels in other patients with papillary adenocarcinoma were not significantly higher compared with patients with benign nodules and normal subjects. But a significant positive correlation was found between the diameter of the carcinoma and the serum levels of CA 50 and CA 19-9. These results suggest that the serum levels of CA 50 and CA 19-9 might not become useful markers for diagnosing carcinoma of the thyroid, but might be useful markers for monitoring the growth or recurrence of papillary adenocarcinoma of the thyroid in patients with high serum levels of CA 50 and CA 19-9.

Adenocarcinoma, Papillary↗

PubMed1991

Increased soluble interleukin 2 receptor levels in autoimmune thyroid disease.

We measured soluble interleukin 2 receptor, a part of the Tac protein (p55), in peripheral blood to study the immunological condition of the T cell in autoimmune thyroid disease. In 26 patients with untreated Graves' disease and 7 hyperthyroid patients with Hashimoto's thyroiditis, the mean levels of soluble IL-2 receptor were both significantly higher than in normal controls (1497 +/- 649 (mean +/- SD), 641 +/- 137 vs 221 +/- 63 10(3) U/l, p less than 0.001). There was good correlation between soluble IL-2 receptor levels and blood thyroxine levels (r = 0.684, p less than 0.001) in patients with untreated Graves' disease, but no correlation of soluble IL-2 receptor with TSH-inhibitory immunoglobulins, TS-ab, thyroidal autoantibodies to thyroglobulin and thyroidal microsomal antigen was found. We thought that the level of soluble IL-2 receptor is not dependent only on immunological conditions, but also on thyroid hormone status. When T3 was administered to subjects in remission from Graves' disease and in normal controls, the soluble IL-2 receptor levels significantly increased. Moreover, the mean level of soluble IL-2 receptor in patients with toxic multinodular goitre was also significantly higher than in normal controls (411 +/- 148 vs 221 +/- 63 10(3)U/l, p less than 0.05). We conclude that the soluble IL-2 receptor levels are higher in sera of subjects with elevated levels of thyroid hormone.

Adult↗

PubMed1991

Functional advantage of parenchymal-sparing surgery for early hilar lung cancer.

In a group of 27 patients with early hilar lung cancer, standard sleeve lobectomy was performed in 14 cases, standard lobectomy in 9 cases, and another 4 patients underwent parenchymal-sparing operations (2 had sleeve segmentectomy, 1 had sleeve middle lobectomy, and 1 had left second carinal resection). The changes of conventional pulmonary function tests and regional pulmonary function were compared between patients undergoing sleeve lobectomy and those undergoing parenchymal-sparing surgery. The parameters used for the conventional lung function tests were FVC, %FVC, FEV1.0, and %FEV1.0. For the evaluation of regional pulmonary function, perfusion scans using 99mTc-MAA and ventilation scans using 133Xe were performed. The decrease of FVC in the sleeve lobectomy group (n = 5) was 724 +/- 182.7 ml, whereas that in the parenchymal- sparing surgery group (n = 4) was 367.5 +/- 52.1 ml, a significant difference. Both the FEV1.0 and %FEV1.0 showed no marked changes in both groups between the preoperative and postoperative values. Perfusion and ventilation scans in the parenchymal-sparing group showed a superior result in comparison with sleeve lobectomy group. All the patients undergoing parenchymal-sparing operations survived over the long term. It was thus concluded that parenchymal-sparing surgery can be applied to carefully selected patients with tiny localized cancers.

Aged↗

PubMed1991

Influence of central respiratory activity on the cough response in anesthetized dogs.

Cough responses evoked by mechanical stimulation of the tracheobronchial mucosa in anesthetized and tracheostomized dogs were studied. The most common response was a group of coughs. Phase relationships between coughing and spontaneous respiration during the cough initiation and resolution periods were categorized as either synchronized or unsynchronized. We defined the synchronization as the coincidence of an expiratory thrust and the early-expiratory phase of respiration. During the cough initiation period, the incidence of synchronization increased as central respiratory activity was enhanced by hypercapnia or as the cough center's activity was suppressed by deep anesthesia. Synchronization decreased as central expiratory activity was enhanced by expiratory threshold loading. During the cough resolution period, synchronization occurred in conjunction with a gradual decrease in the cough center's activity. Coughing could be evoked when the dog was made apneic either by hyperventilation or by the Hering-Breuer reflex. In either case, apnea persisted after coughing subsided. These findings suggest that mechanical stimulation directly activates the cough center rather than the respiratory center; and that synchronization is determined by the relative strengths of the respiratory and cough center's activities.

Afferent Pathways↗

PubMed1991

On the laminar formation of the masseter muscle in the lion (Panthera leo).

An investigation was made of the laminar structure of the masseter muscle in 3 lions (Panthera leo s. Felis leo), and the findings obtained were evaluated in comparison with those in some other carnivora. Although the general aspect of the masseter of the lion resembled that of the cat, there was no close similarity or analogy between them. The construction of the masseter in the lion was as follows. The superficial layer consisted of primary and secondary sublayers, the intermediate layer was composed of anterior and posterior portions, and the deep layer also had anterior and posterior portions. Among these three layers (the masseter proper muscle), the superficial layer was extremely well developed as a characteristic feature of this species. The maxillomandibularis muscle was developed in a muscular element of its origin and had its tendinous insertion on the anteroinferior margin of the masseteric fossa. The zygomaticomandibularis muscle was also fairly well developed in the form of two muscular bundles which originated from the temporal crest, a shelf forming a lateral protrusion on the basis of the zygomatic process, and its posterior surface. Both muscles were also well developed as the masseter improper. Such a huge and complicated laminar pattern of the masseter muscle in the lion should be sufficient to exert a strong force as a predatory animal.

Animals↗

PubMed1991

Importance of measuring plasma thrombin-antithrombin III complex levels when using antithrombin III concentrate therapy in fulminant hepatic failure.

We investigated changes in the concentrations of thrombin-antithrombin III complex (TAT) and plasmin-alpha 2 plasmin inhibitor complex (PIC) after the intravenous administration of 4000 units of antithrombin III (AT III) concentrate to patients with fulminant hepatic failure (FHF), subacute hepatitis (SH), or liver cirrhosis (LC). FHF patients showed shortening of the initial half-life of exogenous AT III. In addition, a marked rise in plasma TAT was noted 3 to 6 h after the intravenous administration of AT III, even in patients who had a normal plasma TAT level before AT III therapy. In contrast, SH and LC patients showed no marked changes of plasma TAT levels after AT III administration. No marked changes were observed in the PIC concentration in any of the patients. These findings suggest that thrombin formation is increased in FHF and that simple measurement of the plasma TAT concentration is not an adequate method for assessing thrombin formation in FHF patients who have suspected disseminated intravascular coagulation associated with an apparent decrease in AT III synthesis. Instead, it seems necessary to measure the plasma TAT concentration in FHF patients after replacement therapy with AT III concentrate has been performed, to evaluate their hypercoagulability more accurately.

Adult↗