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Biomedical subjects

T Nagasaka

Publications and source records attributed to T Nagasaka.

At least 19 recordsLinked to original sources

Primary choroid plexus papilloma located in the suprasellar region: case report.

A 34-year-old woman with primary choroid plexus papilloma occurring in the suprasellar region is reported. No connection with the ventricular system was found during intraoperative observations. The findings of pathological examinations such as hematoxylin and eosin staining, transthyretin (prealbumin) immunoreactivity, and electron microscopy were consistent with choroid plexus papilloma. Radiologically, it was extremely difficult to differentiate from tuberculum sellae meningioma. To our knowledge, this is the first case of primary choroid plexus papilloma in this location reported in the literature.

Adult

[Strain differences of mice in learning of swimming behavior and effect of hemicholinium and vasopressin. Observation by a simple water maze apparatus].

In order to determine the strain differences in learning of swimming behavior and to study the influence of vasopressin or its derivatives on hemicholinium-3-induced impairment of water maze learning in mice, we designed a new apparatus using water maze which has three panels in small fish breeding water bath (L60 x W30 x H36 cm). In the first swimming, six strains of adult male mice, ICR, ddY, ddN, C3H/He, BALB/C and C57BL were subjected to learn swimming behavior twice a day for 6 d in a straight course. Only ICR, ddN, C57BL and BALB/C strain mice were chosen for the next experiment. In the second swimming, mice (ICR, ddN, C57BL, BALB/C) were swum in the water maze apparatus. Scopolamine-induced impairment of water maze learning was produced only in ICR, BALB/C mice, but not in C57BL and ddN strain, which was recovered by physostigmine. Amnesia was not obtained by intracerebroventricular injection (i.c.v.) of cycloheximide and AlCl3 in mice (ICR). Hemicholinium-induced amnesia was improved by vasopressin and desmopressin. Lysine-vasopressin and oxytocin were without affecting hemicholinium-induced amnesia. Pretreatment with a vasopressin antagonist, ([1-(beta-mercapto-beta,beta-cyclopenta-methylene propionic acid), 2-(o-methyl)tyrosine arginine]-vasopressin) resulted in a reversible effect on the improvement of hemicholinium-induced amnesia by vasopressin. Of four different strain mice, ICR mice were the most preferable to the presently used test. They were also more responsive to hemicholinium and vasopressin than the other strains. These results suggest that the simple water maze apparatus may be useful for a pre-examination of nootropics or a study of learning of swimming behavior in mice.

Animals

[Synthesis of 1-trans-cinnamoyl- and 1-[trans-3-(pyridyl)acryloyl]-2-pyrrolidinone derivatives and their effect on hemicholinium-induced impairment of water maze learning in mice].

Various 1-trans-cinnamoyl-2-pyrrolidinones (6a-k) and 1-[trans-3-(pyridyl)acryloyl]-2-pyrrolidinones (9a-c) were prepared as analogues of the notropic agent, aniracetam (2), and their effects on hemicholinium-induced impairment of water maze learning in mice were examined. 1-(trans-3-Methoxycinnamoyl)-, 1-(trans-4-methoxycinnamoyl)- and 1-(trans-4-chlorocinnamoyl)-2-pyrrolidinones (6c, d, h) and 1-[trans-3-(3-pyridyl)acryloyl]-2-pyrrolidinone (9c) were found to be more active than aniracetam in these tests. In addition, these 2-pyrrolidinones (6a-k, 9a-c) were apparently observed to lengthen mouse survival time following hemicholinium injection into the brain.

Animals

Immunohistochemical characterisation of extracellular matrix components of salivary gland tumours.

Proteoglycans (PGs) were localised immunohistochemically in 52 salivary gland tumours including pleomorphic adenoma, adenoid cystic carcinoma, acinic cell carcinoma, oncocytoma, mucoepidermoid carcinoma, clear cell tumour and Warthin tumour, using antibodies raised against large PG, small PG, chondroitin 4-sulphate PG, chondroitin 6-sulphate PG, heparan sulphate PG and keratan sulphate PG. Large PGs were mainly observed in mucinous materials of extracellular matrix (ECM) and interstitial fibrous element of tumour tissues, while small PGs were located only in hyaline matrix and surrounding fibrous (capsular) connective tissues. Chondroitin 6-sulphate PG was detected in the ECM of pleomorphic adenomas and clear cell carcinomas and in pseudocystic spaces of adenoid cystic carcinomas, but only in vessel walls in non-neoplastic tissues. Keratan sulphate PG was observed to locate in mucinous material of pleomorphic adenomas, acinic cell carcinomas and clear cell carcinomas, but not in the adenoid cystic carcinomas examined, and it was also unobservable in non-neoplastic salivary gland tissues. Heparan sulphate PG was observed on the inner surfaces of true ductal spaces of adenoid cystic carcinomas and on cell surfaces of oncocytoma cells. By HPLC analysis, individual glycosaminoglycans contained in tumour tissues were compared. Chondroitin 6-sulphate PG was very rich in ECM of pleomorphic adenomas and adenoid cystic carcinomas. Pleomorphic adenomas contained relatively more low-sulphated chondroitin sulphate than adenoid cystic carcinomas and other tumours.

Chondroitin Sulfates

Effect of heat acclimation on diurnal changes in body temperature and locomotor activity in rats.

1. The present study was performed to examine the effects of heat exposure hours hours at a fixed time once a day on diurnal variations of deep body temperature, heat balance and locomotor activity in rats. 2. The heat-exposed group (HE) was subjected to an ambient temperature of 33.5 degrees C for about 5 h in the last half of the dark phase daily for at least 10 consecutive days, while the control rats were constantly kept at 24 degrees C. 3. After the completion of the heat exposure schedule, hypothalamic temperature (Thy), heat loss, heat production and locomotor activity of HE rats significantly decreased for 3-4 h during the period of previous heat exposure time and formed a characteristic trough in the dark phase, which was never observed in the control rats or in the HE rats before the start of the heat exposure schedule. 4. The troughs of Thy, heat loss and heat production in the dark phase were persistent for at least 2 days after the end of the heat exposure schedule. The reductions of locomotor activity in this period were, however, observed only on the first day after stopping the heat exposure schedule. 5. These results suggest that the time memory for heat exposure was formed in heat-acclimated rats and was persistent for at least 2 days after the removal of heat exposure. It is also concluded that the reduction in metabolic heat production contributed to the fall of Thy during the period of heat exposure.

Acclimatization

Mechanism of vasoconstriction in the rat's tail when warmed locally.

The vascular response of the tail to local warming was investigated in urethan-anesthetized rats whose colonic temperature was maintained at 39.5 degrees C with an intravenous thermode at an ambient temperature of 23 degrees C. The tail, covered with thin latex tubing, was immersed in temperature-controlled water initially kept at 35 degrees C. The tail was warmed by raising the water bath temperature from 35 to 44 degrees C at a constant rate. Tail blood flow (BF), mean arterial blood pressure (BP), and tail skin temperature (Tsk) were measured before and during the local warming. Tail vascular conductance (VC) was computed as 100 x tail BF/BP. When Tsk exceeded 37 degrees C, tail BF and VC significantly decreased from the levels at Tsk of 35 degrees C, and significant reductions in tail BF and VC occurred until Tsk reached 42 degrees C. Surgical deafferentation of the tail, chemical sympathectomy with 6-hydroxydopamine (100 mg/kg), and alpha-blockade with phentolamine (7 or 40.1-45.5 mg/kg) or phenoxybenzamine (5 mg/kg) failed to stop the decrease in tail BF and VC during the local warming. These results suggest that a reflex via the central nervous system and the alpha-adrenergic sympathetic nervous system is not indispensable for heat-induced vasoconstriction (HIVC). It is therefore assumed that, at least in the rat's tail, HIVC predominantly originates from a local vascular response to high temperature.

Animals

Temperature regulation during acute heat loads in rats after short-term heat exposure.

Eleven rats were kept at an ambient temperature of 33.5 degrees C (HC) for 4-5 consecutive days, 9 additional rats were subjected to 33.5 degrees C for approximately 5 h daily (HI) for the same period, and 12 controls (Cn) were kept at 24 degrees C. After the exposure, the rats were placed in a direct calorimeter, where the wall temperature was set at 24 degrees C, and subjected to direct internal heating (6.2 W.kg-1, 30 min) through an intraperitoneal electric heater. After the first heat load and when thermal equilibrium had been attained again, the rats were subjected to indirect external warming by raising the jacket water temperature surrounding the calorimeter from 24.0 to 38.8 degrees C in 90 min. Hypothalamic (Thy) and colonic temperatures (Tco), evaporative and nonevaporative heat loss, and metabolic heat production (M) before the acute heat loads did not differ among the groups. During heat loads, the latent times for the onsets of the rises in tail skin temperature and evaporation were significantly longer, and Thy and Tco at the start of increases in heat losses tended to be higher, in the HC than in the Cn. M significantly decreased in all groups, but the magnitude and duration of reduction in M were significantly greater in the HC than in the Cn. There were no differences between the thermoregulatory responses to heat loads of the HI and Cn. These results suggest that in HC the threshold core temperature for heat loss response and the upper critical temperature have already shifted to a higher level and that HC respond to heat stress more strongly with the reduction of M than Cn. Short-term intermittent heat exposure had little effect on the thermoregulatory mechanisms in rats.

Acclimatization

[A case report of mediastinal paraganglioma and a review of the literature in Japan].

Paraganglioma is a tumor arising from the extra-adrenal paraganglion system and is rarely observed in the mediastinum. The authors experienced a case of nonfunctioning paraganglioma of the upper posterior mediastinum. The patient was a 40-year-old female in whom abnormal shadows were noted in chest X-ray films taken in March, 1989. She was examined at our hospital with a diagnosis of mediastinal tumor in June of the same year. CT of the chest revealed a tumor in the upper posterior mediastinum and it was shown to be hypervascular by a DSA study. Urinary hormone levels were normal. The tumor was resected in May, 1990. The tumor, measuring 6.8 X 4.0 X 3.5 cm, was encapsulated, appeared dark red and had relatively clear borders. A histopathologic diagnosis of paraganglioma was made. The patient remains disease-free at present, 6 months after operation. Problems concerning diagnosis and treatment of mediastinal paraganglioma were evaluated with a review of cases reported in Japan.

Adult

[Histological differences between sternal and iliac bone marrow in various hematological diseases].

Even in normal state, hematopoietic activity is different in terms of the site of bone marrow as well as age. The activity may also differ with bone marrow site in various hematological diseases. We chose 32 cases with various hematological diseases and examined their bone marrow histologically at two different sites (sternum and posterior iliac crest) at almost the same time. We studied the histological differences in 5 cases of malignant lymphoma, 15 cases of aplastic anemia, 8 cases of myelodysplastic syndrome, 2 cases of myeloproliferative syndrome and 2 cases of acute leukemia. In malignant lymphoma, the iliac marrow was slightly hypoplastic compared with sternal marrow but there were no differences in the components of hematopoietic cells, that were thought to reflect normal hematopoietic activity for their respective ages. In 5 among 15 cases of aplastic anemia, nodular hyperplastic areas were observed in sternal marrow even though iliac marrow was severely hypoplastic. The presence of a nodular hyperplastic area is useful for differential diagnosis between aplastic anemia and refractory anemia, because such a histological change was not observed in the cases of refractory anemia. In myeloproliferative syndrome and acute leukemia, there were no differences between sternal and iliac marrow. They were hyperplastic and had almost the same hematopoietic components.

Adult

Interleukin 4 and gamma-interferon may play a role in the histopathogenesis of peripheral T-cell lymphoma.

The first demonstration of cytokine expression in T-cell lymphoma by immunohistochemical methods is reported. Lymph node biopsy specimens were obtained from 18 patients with peripheral T-cell lymphoma. Interleukin 4 (IL-4) and gamma-interferon were each detected in 7 lymph nodes. Lymph node specimens diagnosed as angioimmunoblastic T-cell lymphoma and angiocentric lymphoma having distinctive histopathological features expressed IL-4 more frequently than other T-cell lymphomas, and all 7 patients expressing IL-4 had hypergammaglobulinemia. Lymph nodes with gamma-interferon expression showed an increase in histiocytes and/or epithelioid cells. Thus, IL-4 may play an important role in the development of hypergammaglobulinemia as well as in the growth and histopathogenesis of T-cell lymphoma, and gamma-interferon may be responsible for the development of Lennert's lesion.

Antibodies

Immunohistochemical characterization of extracellular matrix components of yolk sac tumors.

Proteoglycans (PGs) were isolated from yolk sac tumor and chondroitin sulfate large PG (core molecule with a molecular weight congruent to 200,000) and small PG (core molecule with a molecular weight congruent to 50,000) were detected. Immunohistochemical localization of PGs in three yolk sac tumors was investigated using monoclonal antibodies raised against both small and large PGs, which were purified from human ovarian fibroma capsule and a yolk sac tumor, respectively. The localization of large PG was observed to be distinct from that of small PG. A markedly positive reaction for antibody against large PG was observed in myxomatous areas, perivascular and perivesicular portions; hyaline globules were the most intensely reactive. In the areas showing a polyvesicular vitelline tumor pattern, the compact connective tissue stroma consisted of small PGs. It is conceivable that large PGs are synthesized by immature mesenchymal cells and also by epithelial-like cells as a basement membrane component, whereas small PGs are synthesized by mature fibroblastic cells synthesizing collagen. Immunohistochemical localization of other extracellular matrix components (laminin, fibronectin, type I-IV collagen) was also studied in relation to PG localization.

Adult

Ovarian epithelial tumors of borderline malignancy in Japan.

Seventy-one cases of ovarian epithelial tumor of borderline malignancy have been surveyed from a clinicopathologic viewpoint. The majority of the borderline tumors (73.2%) were of the mucinous type, versus only 16.9% of the serous type. The other types--endometrioid (2.8%), Brenner (1.4%), and mixed type (5.6%)--were much rarer. Patients with mucinous tumors were significantly younger (mean age 42.6) than those with serous tumors (mean age 57.5) (P less than 0.01). Of patients with mucinous tumors, 64.2% were of reproductive age (15-45 years), compared with 17% of patients with serous tumors. Some 78.8% of mucinous and 83.3% of serous borderline tumors were FIGO stage I. Serous tumors were more frequently bilateral (66.7%) than mucinous tumors (9.8%). In mucinous borderline tumors, the extent of tumor spread at the first laparotomy had an intimate relationship to the prognosis, but in serous borderline tumors, it was insignificant. The survival rate of patients with mucinous borderline tumors was 69.3% at 5 years and 62.4% at 10 years (Kaplan-Meier method). Most patients with pseudomyxoma peritonei classified as borderline at the time of discovery died within 5 years of the operation. The prognosis of the serous type was extremely favorable. Criteria for borderline tumors of various cell types and differences in the clinicopathologic data of ovarian borderline tumors between Japan and other countries were discussed.

Adenocarcinoma

Study of ovarian tumors treated at Nagoya University Hospital, 1965-1988.

The relative frequency and the age distribution of ovarian tumors (873 primary and 47 secondary tumors) encountered over 23 years at Nagoya University Hospital were examined with respect to histological type and grade of malignancy. Of the primary neoplasms, common epithelial tumors accounted for 56.6%, sex cord-stromal tumors for 7.3%, and germ cell tumors for 39.5%. Among 296 cases with primary malignant neoplasms, common epithelial type accounted for 75.6%, sex cord-stromal tumors for 4.7%, and germ cell tumors for 19.6%. A review of the literature from Western countries indicated that in Japan, the relative frequency of common epithelial tumors is lower but that of germ cell tumors, especially malignant germ cell tumors, is higher. The difference in the incidence of germ cell tumors between Japan and Western countries is not considered significant, and the incidence of common epithelial tumors is considered to be much lower in Japan.

Adolescent

Thermoregulatory responses to acute body heating in rats acclimated to continuous heat exposure.

Thermoregulatory responses to an acute heat load with intraperitoneal heating (IH) or indirect external warming (EW) by increasing ambient temperature (Ta) were investigated with direct and indirect calorimetry in rats acclimated to environments of 24.0 degrees C (Cn), 29.4 degrees C (H1), and 32.8 degrees C (H2) for greater than 15 days. The rats were placed in a direct calorimeter where the air temperature was maintained at 24 degrees C for the initial 3 h. IH was then made for 30 min through an electric heater implanted chronically (6.5 W.kg-1) in the peritoneal cavity, and EW was performed by raising the jacket water temperature surrounding the calorimeter from 24 to 39 degrees C (0.19 degrees C.min-1). Hypothalamic (Thy) and colonic temperature immediately before the start of the heat load tended to be higher as the acclimation temperature increased. During IH, the threshold Thy for the tail skin vasodilation (Tth) was significantly higher in H2 than in Cn rats. During EW, however, there was no difference in Tth between the groups. Metabolic heat production (M) was slightly suppressed during IH and significantly depressed only in H2 rats. During EW, M was suppressed in all the groups. The magnitude and duration of suppression were greater in H2 rats than in the other two groups. The responses in nonevaporative heat loss and thermal conductance (C) to the rise in Thy did not differ among the three groups during IH. According to the rise in Thy, however, there was a greater C increase in H2 than in Cn and H1 rats during EW.(ABSTRACT TRUNCATED AT 250 WORDS)

Acclimatization

Heat loss responses in rats acclimated to heat loaded intermittently.

The present study examined the heat loss response of heat-acclimated rats to direct body heating with an intraperitoneal heater or to indirect warming by elevating the ambient temperature (Ta). The heat acclimation of the rats was attained through exposure to Ta of 33 or 36 degrees C for 5 h daily during 15 consecutive days. Control rats were kept at Ta of 24 degrees C for the same acclimation period. Heat acclimation lowered the body core temperature at Ta of 24 degrees C, and the core temperature level was lowered as acclimation temperature increased. When heat was applied by direct body heating, the threshold hypothalamic temperature (Thy) for the tail skin vasodilation was also lower in heat-acclimated rats than in the control rats. However, the amount of increase in Thy from the resting level to the threshold was the same in all three groups. When heat was applied by indirect warming, threshold Thy was slightly higher in heat-acclimated than in control rats. The amount of increase in Thy from the resting level to the threshold was significantly greater in heat-acclimated rats. In addition, Ta and the skin temperature at the onset of skin vasodilation were significantly higher in heat-acclimated rats. The results indicate that heat-acclimated rats were less sensitive to the increase in skin temperature in terms of threshold Thy. The gain constant of nonevaporative heat loss response was assessed by plotting total thermal conductance against Thy.(ABSTRACT TRUNCATED AT 250 WORDS)

Acclimatization

Heat-induced finger vasoconstriction controlled by skin sympathetic nerve activity.

Finger blood flow (BF) and skin sympathetic nerve activity (SSA) to the glabrous side of the hand were measured during immersion of the hand in a water bath in which temperature (Tw) was raised every 10 min by steps of 2 degrees C from 35 or 37 to 41 degrees C. The experiments were conducted during the summer in rooms in which ambient temperature was 28-32 degrees C or 35 degrees C. The nine healthy male subjects were wearing summer clothes. Finger BF through vessels located deep in the skin was measured by using laser-Doppler flowmetry (ALF-2100, Advance). With the use of a tungsten microelectrode SSA was recorded directly from the median nerve at the wrist or antecubital fossa of the tested arm. With finger vessels already dilated at Tw of 35 or 37 degrees C, finger BF decreased, with a concomitant increase in the SSA bursts as Tw rose to 39-41 degrees C. We confirmed in one subject that anesthetic blockade of the median nerve at the site proximal, but not distal, to the recording site blocked responses to the step rise in Tw in the SSA bursts and in finger BF. From these results we conclude that, with the subject in a warm state, blood vessels of the finger respond to local heating with vasoconstriction, and this finger vasoconstriction is evoked reflexively, largely through the increased sympathetic outflow to the resistance vessels of the finger.

Adult

[Myxomatous stromal changes in bone marrow following chemotherapy of acute leukemia--immunohistochemical characteristics of matrix components].

Although fibrosis and gelatinous transformation of bone marrow stroma are well known, there have been few histopathological descriptions in the literature. We studied 16 cases of acute leukemia, and describe the myxomatous changes of bone marrow stroma observed at 2 or 3 weeks following chemotherapy. We analyzed the extracellular matrix components immunohistochemically, using monoclonal or polyclonal antibodies raised against collagens, proteoglycans (PG), fibronectin and laminin. We found that the major components of the myxomatous matrix were chondroitin 6-sulfate PG and large PG. The stainability resembles that of extracellular matrix components in long-term bone marrow culture. We suppose that the myxomatous matrix provides favorable conditions for hematopoiesis, because hematopoietic cells proliferate and differentiate as soon as such stromal changes occur.

Adolescent