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Biomedical subjects

F Sasaki

Publications and source records attributed to F Sasaki.

At least 127 records · Page 7Linked to original sources
PubMed1993

[Immunocytochemical observation of adenohypophysis in a human growth hormone (hGH) gene transgenic mouse].

Adenohypophysis was immunocytochemically examined in an infertile female transgenic (Tg) mouse which carried human growth hormone (hGH) gene and had a high circulating level of hGH. No GH positive cells were detected. This confirmed the extrahypophyseal (ectopic) production of hGH and was coincident with the disappearance of parenchymal cells showing affinity to azocarmine in Azan staining. The normal frequency of ACTH positive cells was in accordance with the previous suggestion based on the changes found in zona fasciculata cells of the adrenal cortex. Most interesting findings were the detection of many PRL positive cells and the ovarian histology with nearly normal characteristics except for the presence of thick capsule and interstitial gland-like structure composed of large and light cells. Ovarian histology was also clearly different among individual Tg mice, even though they stemmed from the same line or progenitors, and had a similar phenotype. The current immunocytochemical observation well documented the changes revealed with Azan staining in the adenohypophysis about GH but not about PRL or ACTH. Thus, the immunocytochemical analysis of the adenohypophysis will provide useful methodology in assessment of endocrinological circumstances of Tg mice.

Adrenocorticotropic Hormone↗
PubMed1993

[Elevation of spontaneous tone and effects of antihypertensive treatments in arterial smooth muscle of spontaneously hypertensive rats].

Mechanisms of elevation of active tone in arterial smooth muscle of spontaneously hypertensive rats and effects of antihypertensive treatments are reviewed. Spontaneously hypertensive rats are created by Okamoto et al. and classified mainly into three strains, SHR, SHRSP and M-SHRSP. Blood pressure of the rats is higher in this order. The aortic smooth muscle of these rats exhibits elevation of the active tension (tone) under non-stimulated condition. The active tone is greater as the blood pressure of the rats elevated and good correlation between blood pressure and active tone can be obtained. The active tone is sensitive to extracellular Ca and abolished by the removal of extracellular Ca or by the application of Ca-antagonists. It is also associated with increased intracellular Ca level. These results indicate that the active tone is brought about by increase in voltage-dependent Ca channel opening of the cell membrane. Increased voltage-dependent Ca channel opening, i.e. membrane depolarization and increased inward Ca current can be a cause of the elevated tone. Abnormalities in the cellular mechanisms for relaxation of the smooth muscle can also contribute to the elevation of the active tone. Endothelium suppresses the active tone, probably releasing endothelium-derived relaxing factor or hyperpolarizing factor. The suppression of contraction by endothelium is impaired in the blood vessels of spontaneously hypertensive rats, depending on the degree of hypertension. Antihypertensive treatments prevent the development or elevation of the active tone. It also prevents the impairment of function of endothelium. Thus, the maintained hypertension alters functions of smooth muscle membrane and endothelium. The degree and duration of hypertension are thought to be determinant factors of these abnormalities.

Animals↗
PubMed1993

Relationship between blood pressure and smooth muscle tone in aortae of hypertensive rats: roles of [Ca2+].

Spontaneously developed tension (active tone) and intracellular Ca2+ level of aortae from spontaneously hypertensive rats (SHR), stroke-prone SHR (SHRSP), malignant SHRSP (M-SHRSP) and control Wistar Kyoto rats (WKY) were compared. Systolic blood pressure of WKY, SHR, SHRSP and M-SHRSP was 130 mmHg, 200 mmHg, 250 mmHg and 260 mmHg, respectively. Preparations from all strains of spontaneously hypertensive rats exhibited active tone which was abolished by the removal of extracellular Ca2+ or by the application of verapamil. The active tone was greater in the order of aortae from SHR < SHRSP < M-SHRSP. Intracellular Ca2+ level measured by Fura-2 method decreased by the removal of extracellular Ca2+. The degree of the decrease was greater as the blood pressure of the rats increased, indicating the greater elevation of intracellular Ca2+ level in the pressure of extracellular Ca2+. A correlation was obtained between the active tone, intracellular Ca2+ level and blood pressure. Thus, it was demonstrated that the development of the active tone is brought about by the changes in Ca2+ influx of smooth muscle cell membrane and the degree of the change is positively related to the degree of hypertension.

Animals↗
PubMed1993

[Adult case of bronchial asthma induced by chironomid midges].

A 48-year-old woman who was diagnosed to have bronchial asthma induced by chironomid midges is reported. In spring of 1985, massive growth of chironomid midges occurred in the river beside her house. Since then, moderate growth has occurred in every spring or summer. She had wheezing attacks every May or June since June 1986. On May 2, 1991, she was hospitalized because of exacerbation of wheezing and dyspnea. Wheezing attacks were improved by appropriate medical treatment during hospitalization. Examination was performed during the state of stable clinical symptoms. RAST scores to Chironomus thummi thummi (CTT) and Chironomus plumosus (CP) were 4 and 3, respectively. Allergic skin reaction showed the threshold dilution of CP of 10(-6). CP skin test concomitantly provoked a mild acute asthma attack. The midges found swarming around her house were identified as Chironomus nippodorsalis. According to her clinical history and allergic skin reactions followed by acute asthmatic attack, this patient was diagnosed to have bronchial asthma induced by chironomid midges. Chironomid midge can be one of the inhalant allergens in adults.

Adult↗
PubMed1993

[Effects of cilostazol, a cyclic AMP phosphodiesterase inhibitor, on pulmonary vascular tone].

We examined the effect of Cilostazol, a cyclic AMP phosphodiesterase inhibitor, rat isolated pulmonary arterial ring tone. Cilostazol dilated pulmonary arterial rings pre-contracted with 10(-6) M phenylephrine in a dose-dependent manner (ED50 3.00 x 10(-6) M). This vasodilatory effect of Cilostazol was not affected by pretreatment with meclofenamate (10(-5) M), mechanical endothelium denudation, methylene blue (10(-5) M) or nitro-L-arginine (2 x 10(-4) M). The vasodilatory effect of Cilostazol on rat thoracic aortic rings was stronger than that on rat pulmonary arterial ring (ED50 1.89 x 10(-6) M). Cilostazol (10(-6) M-10(-4) M) inhibited hypoxic contraction of rat pulmonary rings in a dose-dependent manner. Our experimental data indicated that Cilostazol caused vasodilation regardless of vascular endothelium function and inhibited hypoxic contraction due to inhibition of cyclic AMP phosphodiesterase.

3',5'-Cyclic-AMP Phosphodiesterases↗
PubMed1993

[Combination therapy with low dose adriamycin for advanced or recurrent breast cancer. Hokkaido Breast Cancer Treatment Study Group].

Comparative clinical trials among 3 regimens for patients with advanced or recurrent breast cancer were performed as a multi-institutional joint study. Arm-I of 3 regimens consisted of a 3-day consecutive administration of adriamycin (ADM) at 10 mg/body every 4 weeks, a daily oral administration of cyclophosphamide (CPA), 5-FU and tamoxifen (TAM) at 100 mg, 200 mg, and 20 mg, respectively, and a once-a-week intramuscular or subcutaneous injection of OK-432 (OK) gradually increased from the initial dose of 1 KE to the maintenance dose of 5 KE. Arm-II contained methotrexate (MTX) at 10 mg/body for 3 consecutive days every 4 weeks in place of ADM in Arm-I. Arm-III contained neither ADM nor MTX. Of 69 cases registered, 52 were eligible, leaving 6 non-eligible and 11 incomplete cases. The results of the overall evaluation of 48 complete cases other than 4, in which the tumor was not exactly measured, were as follows. Arm-I resulted in 2 CR and 3 PR out of 19 cases, the response rate being 23.6% (5/19). Arm-II resulted in 1 CR out of 15, the response rate being 6.7% (1/15). In Arm-III, no response cases were found. No significant difference was observed among three treatment groups (p = 0.055), but in Arm-I, the response rate was higher than in the other treatment groups, suggesting that there is a probability of useful combined use of ADM.

Adult↗
PubMed1993

[Changes in arterial blood flow patterns by patients' posture during hepatic arterial infusion chemotherapy assessed by 99mTc-MAA perfusion scintigraphy].

Hepatic arterial perfusion scintigraphy (HAPS) with 99mTc-macroaggregated albumin (MAA) was performed to reveal the effect of patients' posture for the arterial blood flow patterns in hepatic arterial infusion (HAI) chemotherapy. 20 patients of liver metastases with the percutaneously implanted catheter into the hepatic artery underwent HAPS following administration of 99mTc-MAA at the supine and the upright position under one week interval. 10 ml of the saline with radionuclide was injected at a rate of 1 ml per minute. Acquired two images at the different position of each patient were compared and grouped into three classes; similar, slightly different and different. Of 20 patients, 6 (30%) were judged as similar, 8 (40%) as slightly different, and 6 (30%) as different. These results suggest that the drug distribution can change by patients' posture in case of the slow rate HAI performed with continuous infusion pump.

Adult↗
PubMed1993

Surgical treatment of congenital biliary dilatation associated with pancreaticobiliary maljunction.

The excisional surgical treatment of 50 patients with congenital biliary dilatation (CBD) associated with pancreaticobiliary maljunction (PBMJ) was analyzed. There were two patients who had early complications of lesser bile juice leakage with a maximum duration of 21 days, but no pancreatic juice leakage was noticed. As a late complication, two strictures at the anastomotic portion of the hepaticojejunostomy and one intrahepatic gallstone formation were encountered, but no malignant lesion was evident. Both patients with strictures could be predicted using postoperative cholangiography performed two weeks postoperatively and underwent hepaticojejunostomy. Intrahepatic gallstones were treated with lateral segmentectomy of the liver and electrohydraulic lithotripsy through percutaneous transhepatic cholangioscopy. Accordingly, these results suggest that excisional surgical treatment is the most appropriate method for CBD with PBMJ; however, special care must be taken, such as creating a sufficiently wide anastomotic stoma to enable free drainage of bile into the intestine; also, there should be precautions against ischemia at the anastomotic portion. The importance of the postoperative cholangiography to predict the postoperative outcome should be emphasized. Furthermore, causes of intrahepatic gallstone formation should be studied in such instances.

Adolescent↗
PubMed1993

[Home intermittent negative pressure ventilation in a case of chronic respiratory failure due to old tuberculous pleuritis].

A 64-year-old male with a history of tuberculous pleuritis at age 29 had received home oxygen therapy since age 58 because of chronic respiratory failure. He was admitted with symptoms of dyspnea at rest and myoclonus at age 62. Because CO2 narcosis occurred twice, we performed intermittent negative pressure ventilation (INPV) after short-term positive pressure ventilation with transnasal intubation. He has received INPV for 7 hours every day at his home for 20 months without acute exacerbation of respiratory failure, and his activity of daily life subsequently improved. In conclusion, INPV seems to be useful for patients with chronic hypercapnic respiratory failure due to lung disease.

Chronic Disease↗
PubMed1993

[Prevalence of anti C100-3 and HBsAg in blood donors--comparative study of total collected blood units, total collection adjusted to exclude repeat blood donations, and in first time blood donors].

Prevalence of anti C100-3 and HBsAg in donor blood collected at the Hiroshima Red Cross Blood Center during the period of Aug., 1990 to July, 1991 was studied in three groups--total received blood units (187,532 units) without any adjustment, blood units after adjustment by excluding repeat donations of blood units by the same donors (142,160 units), and blood units of first time donors (28,596 units). The results of the study is summarized as follows. 1) There was no significant difference in the prevalence of anti C100-3 between the group comprising the total collected units, and the group after the adjustment. This result suggests that repeat donors do not necessarily belong to any fixed age group. 2) The prevalence of HBsAg is significantly higher in the first time donor group than in the other two groups. In both the total blood units group and the group after the adjustment, prevalence of HBsAg among older age groups was as low as that of younger age groups. This is presumably because of the introduction of selective exclusion of HBsAg positive subjects from donors since 1980. When data from blood donors are used for the epidemiological studies of viral infection among healthy subjects, it is important to know the characteristics of such donor subjects and whether or not they are pre-screened for the viral markers in question.

Adolescent↗
PubMed1993

[The appearance and enlargement of localized pulmonary granuloma with eosinophilic infiltration during tuberculosis chemotherapy].

A pulmonary tumorous shadow appeared and enlarged in a 25 years-old male patient undergoing intensive chemotherapy for tuberculosis. The chest X-rays taken on admission revealed effused pleura in the right lung and nodular shadows in the upper area of the right lung. After 40 days of using isoniazid (INH), rifampicin (RFP) and streptomycin (SM), a homogeneous opacity, not previously observed, appeared in the middle area of the right lung (S5). Microscopic examination of the tissues obtained during a transbronchial lung biopsy disclosed epithelioid cell granulomas with marked eosinophilic infiltration. The presence of eosinophilic infiltration due to the admission of antituberculosis agents was disregarded because no change was observed in the new granulomatous shadows during the drug challenge tests and the lymphocyte stimulation test to INH, RFP and SM was negative. Transient aggravation during the initial phase of chemotherapy for pulmonary tuberculosis, such as in this case, is suspected cause by some eosinophilic allergic-induced mechanisms, against bacillary components.

Adult↗
PubMed1992

Mammotropes and somatotropes in the adenohypophysis of androgenized female mice: morphological and immunohistochemical studies by light microscopy correlated with routine electron microscopy.

Female mice were divided into androgenized (AF) and control (CF) groups. The AF mice were injected subcutaneously with testosterone propionate (Tp) and the CF mice with sesame oil at 5 days of age. Mammotropes (PRL cells) and somatotropes (GH cells) in the adenohypophyses of these mice when they became adults were studied with immunohistochemistry and morphometry by light microscopy correlated with routine electron microscopy. In CF mice, almost all of the PRL-immunoreactive cells (about 43% of all parenchymal cells) were type I (classical) PRL cells, and almost all of the GH-immunoreactive cells (about 30% of all parenchymal cells) were type I (classical) GH cells. Type II PRL cells accounted for about 0.4% of parenchymal cells, and type II GH cells were about 2.5% of all parenchymal cells. In AF mice, the percentages of PRL and GH cells were not significantly different from those of CF mice. Mammosomatotropes (Ms cells) in both groups were less than 1% of all parenchymal cells. Numbers of all parenchymal, PRL and GH cells, however, were increased significantly in AF mice when compared to those in CF, because the adenohypophysis was increased in volume in AF mice. Type I PRL cells were larger in AF than in CF. The ultrastructure suggested that type I PRL cells may show increased PRL synthesis and secretion in AF mice. Furthermore, AF mice, in which the hypothalamus is masculinized by the neonatal treatment with Tp, retained feminine characteristics in the population and size of PRL cells and GH cells in the adenohypophysis.

Androgens↗
PubMed1992

Immunohistological analysis in the distribution of cells in the fetal porcine adenohypophysis.

Adenohypophyses of porcine fetuses from 25 to 110 days of gestation were studied by immunohistochemical staining to ascertain the ontogeny of specific cell types and their spatial distribution in the pars distalis. No hormone-containing cells were found before 30 days of gestation. ACTH cells were observed first at 40 days, while GH and LH cells appeared first at 60 days. PRL cells were initially detected at 105 days. ACTH immunoreactive cells were also observed in the pars intermedia at 40 days. Blood capillaries were interposed between cell cords of the pars distalis after 40 days of gestation. ACTH cells were evenly distribution in all areas of the pars distalis except the rostral area (sex zone). GH cells were densely distributed in lateral wings of the pars distalis and immediately anterior to Rathke's lumen. PRL cells resembled GH cells in their distribution pattern, but PRL cells were fewer in number. LH cells were scattered in the sex zone of the pars distalis from 60 to 80 days of gestation. After 90 days, they became scattered throughout the pars distalis but were more numerous in the sex zone than in other areas. The inductive elements of adenohypophysial cells from Rathke's pouch epithelia are discussed. We hypothesize that cell cords of specific areas facing Rathke's lumen may differentiate into specific cell types of the pars distalis during fetal life.

Adrenocorticotropic Hormone↗
PubMed1992

Fate of ciliated epidermal cells during early development of Xenopus laevis using whole-mount immunostaining with an antibody against chondroitin 6-sulfate proteoglycan and anti-tubulin: transdifferentiation or metaplasia of amphibian epidermis.

Xenopus embryonic epidermis changes its cellular composition during development: the appearance of ciliated epidermal cells before hatching is a remarkable characteristic. In this study, the functional change of ciliated cells to mucus-secreting cells was examined with immunocytochemistry using anti-tubulin and anti-chondroitin 6-sulfate (C6S). Before hatching, most epidermal cells were labeled with anti-C6S in a granular fashion. Immunoelectron microscopy revealed that the anti-C6S-positive structure was the mucus granule. Ciliated epidermal cells lacked anti-C6S staining, but were strongly labeled with anti-tubulin. After hatching, most ciliated cells in the surface of the embryo disappeared. During their disappearance, some ciliated cells exhibited anti-C6S-positive granular labeling. This strongly suggests that the disappearance of ciliated cells is a functional conversion to mucus-secreting cells instead of shedding through cell death.

Actins↗
PubMed1992

Liver regeneration following portacaval shunt in rats: 3',5'-cyclic AMP changes in plasma and liver tissue.

Hepatic regeneration following portacaval shunt was evaluated in the light of the changes of 3',5'-cyclic AMP (cAMP) levels in plasma and liver tissue, and also plasma cAMP levels after glucagon administration, using a 70% hepatectomy and portacaval shunt model in rats. Ratios of liver to body weight recovered to 60% of pre-operative ratios 2 weeks after the operation. Plasma cAMP level decreased slightly, but insignificantly, 1 day and 3 days after the operation, then recovered to the pre-operative level. Hepatic cAMP concentration increased for 2 weeks after the operation. Plasma cAMP levels induced after glucagon administration did not increase until 3 days after the operation and were only 50% of pre-operative levels 4 weeks after the operation. From these results, liver regeneration following the portacaval shunt was remarkably delayed, but continued until at least 2 weeks after the operation.

Animals↗
PubMed1992

Inflammatory pseudotumor of the liver in children: report of cases and review of the literature.

Two pediatric cases of inflammatory pseudotumor of liver were reported and compared with seven previously reported cases. Clinical presentation was variable but often consisted of fever and vague abdominal symptoms. These two cases were considered to be clinically malignant because angiographically one showed hypervascularity and the other showed the portal vein draining into the lesion to be occluded. There are four previous reports of similar cases complicated with occlusive phlebitis within and around the lesion. All but two of the reported cases underwent major hepatectomy or liver transplantation. However, because of the benign nature of the lesion, the treatment might be more conservative after adequate diagnostic procedures, including needle biopsy, are applied.

Child↗