Search PubMed⌕ Search

Biomedical subjects

S Kitahara

Publications and source records attributed to S Kitahara.

At least 109 records · Page 6Linked to original sources
PubMed1990

Structure of N-gamma-L-glutamyl-L-cysteine ethyl ester monohydrate.

C10H18N2O5S.H2O, Mr = 296.39, monoclinic, P2(1), a = 19.600 (1), b = 7.480 (1), c = 5.061 (1) A, beta = 94.74 (1) degree, V = 739.445 (1) A3, Z = 2, Dm = 1.31, Dx = 1.331 g cm-3, Cu K alpha, lambda = 1.54178 A, mu = 21.4 cm-1, F(000) = 316, room temperature, R = 0.057 for 1263 reflections. The molecule adopts an extended form. The molecules are arranged so as to form double molecular sheets parallel to the bc plane through some hydrogen bonds.

Dipeptides↗
PubMed1990

Changes in cerebral free fatty acids and triacylglycerols in focal cerebral ischemia.

1. Focal cerebral ischemia was induced in anesthetized rats by occluding the stem of the proximal middle cerebral artery. 2. The levels of free fatty acids, such as stearic and arachidonic acids, in the ischemic cerebral cortex increased progressively until 60 min after occlusion, but thereafter they decreased rapidly. 3. In contrast to the time-dependent changes in free fatty acids, the levels of triacylglycerol (TAG) in the ischemic cerebral cortex continued to increase for 120 min after occlusion. Increases in TAG-palmitate, -stearate and -arachidonate accounted for the increase in the triacylglycerol level. 4. The pattern of the lipid changes in focal cerebral ischemia differs from those reported in bilateral diffuse cerebral ischemia induced by arterial occlusion or in decapitation ischemia.

Animals↗
PubMed1990

Incidence and properties of renal masses and asymptomatic renal cell carcinoma detected by abdominal ultrasonography.

Renal ultrasonography was performed in 45,905 adults, including 41,364 without any signs suggesting urinary tract malignancies, 1,667 with microscopic hematuria only and 2,874 with some signs of malignancy. Renal lesions were found in 355 adults (0.858%) in the asymptomatic, 39 (2.3%) in the microscopic hematuria and 75 (2.6%) in the symptomatic groups, respectively. Renal cell carcinoma was found in 35 (7.5%) lesions: 19 (5.4%) in the asymptomatic, none in the microscopic hematuria and 16 (21.3%) in the symptomatic groups. A total of 47 patients, including 12 other renal cell carcinoma patients transferred from related hospitals, was grouped into 28 without and 19 with symptoms. Primary tumor size and clinical stages were significantly smaller and lower, respectively, in the asymptomatic group than in the symptomatic group. Radical nephrectomy was performed in all but 2 asymptomatic patients. The 5-year survival rates after nephrectomy were 94.7 and 60.9% for the asymptomatic and symptomatic groups, respectively (p less than 0.01). The results indicate that ultrasonography is a useful tool to detect low stage asymptomatic renal cell carcinoma at low cost.

Carcinoma, Renal Cell↗
PubMed1990

Effects of castration on luteinizing hormone and follicle-stimulating hormone secretion by pituitary cells from male rats.

Because the role of the pituitary in the testicular control of gonadotropin secretion remains controversial, we examined the effects of castration on the release of LH and FSH under basal conditions and in response to GnRH stimulation by dispersed pituitary cells in monolayer culture as well as by cells perifused with pulses of GnRH. These effects were compared to changes in LH beta, FHS beta, and alpha-subunit mRNA levels determined by Northern blot analysis. Pituitary cells were prepared from 7-week-old intact rats and rats orchidectomized 2 weeks previously. Castration increased basal FSH secretion from monolayer cultures, interpulse FSH release from perifused pituitary cells, FSH beta mRNA concentrations and serum FSH levels each approximately 2-fold, whereas pituitary FSH contents were similar in cells from intact and castrated rats. Pituitary LH content rose 3-fold, LH beta mRNA rose 5.6-fold, and basal LH secretion increased 6-fold, but serum LH levels increased 22-fold. Thus, the change in FSH synthesis inferred from the increase in FSH beta mRNA was proportional to the increase in FSH secretion both in vitro and in vivo. Whereas the basal release of LH in vitro was also proportional to the change in LH beta mRNA, secretion of LH in vivo exceeded these changes, underscoring the importance of increased GnRH to the serum LH castration response. Castration resulted in an increase in the sum of FSH content and secretion during 10 days in culture in the absence of GnRH, indicating ongoing FSH synthesis. Total LH declined in cells from intact rats, and this decline was prevented by castration; this effect may be due to a castration-related decrease in intracellular LH degradation or increased LH synthesis in the absence of GnRH. Castration also augmented the GnRH-stimulated release of LH and FSH from monolayer cultures 4.5- and 1.8-fold, respectively, and increased the amplitude of GnRH-stimulated LH and FSH pulses 5- and 2-fold in experiments with perifused pituitary cells. The EC50 for GnRH was unaffected by castration.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗
PubMed1990

[Experimental investigations of the propagation mechanism and the nerve regulatory mechanism of the interdigestive migrating electric complex in intestinal movement].

Segments and Thirty-Vella type loops of the small intestine of dogs were prepared, and the excitation propagation pattern of the interdigestive migrating electric complex (IMEC) was observed by electromyography. The nerve regulatory mechanism in intestinal movement was investigated. The results indicated that first, the frequency of the basic electric rhythm (BER) is controlled so that a downward gradient is formed from the upper to the lower intestine, but this gradient continues to be controlled by a two-dimensional control mechanism involving parietal factors and extrinsic nerves due to transection of the intestines and damage to the extrinsic nerves in the dominant region. However, propagation of the IMEC in the small intestine appeared to be regulated by a combination of the two-dimensional control mechanism involving extrinsic and parietal nerves corresponding to the BER control mechanism. It was clear that the propagation mechanism of IMEC is related to the BER frequency, and propagation of the IMEC is downward in accordance with the frequency gradient of BER.

Animals↗
PubMed1989

Relationship of changing delta 4-steroid 5 alpha-reductase activity to [125I]iododeoxyuridine uptake during regeneration of involuted rat prostates.

To elucidate the phenotypic expression of proliferating prostatic cells, rats were castrated, and the regenerating process of involuted ventral prostates during testosterone propionate (TP) administration was investigated by examining morphology, [5-125I]iododeoxyuridine (125I-UdR) uptake, DNA content, weight, acid phosphatase, and delta 4-steroid 5 alpha-reductase (5 alpha-reductase) activities. Morphologically, TP treatment initially increased the number of epithelial cells lining glandular lobules and subsequently restored the shape of epithelial cells. 125I-UdR uptake peaked on Day 3 of TP treatment and stayed at higher levels than for uncastrated controls until Day 14 of treatment. Prostatic weight, protein content, acid phosphatase, and DNA content returned to uncastrated control levels by Day 14 of TP treatment. TP administration markedly stimulated prostatic 5 alpha-reductase activity, which peaked on the Day 5 of treatment and decreased to uncastrated control levels by Day 14 of treatment. It is concluded that TP administration to castrated rats initially induced active mitotic division of the remaining stem cells, followed by formation of differentiated functional epithelial cells. Prostatic 5 alpha-reductase was highly active at the initial phase of active mitotic cell division. The major portion of the increased enzyme activity can be regarded as a phenotypic expression of stem or transient cells of prostatic epithelium.

3-Oxo-5-alpha-Steroid 4-Dehydrogenase↗
PubMed1989

[An undifferentiated carcinoma of the stomach--a report of 2 cases].

Two cases of an undifferentiated carcinoma of the stomach have been investigated by conventional histologic, immunohistochemical, and ultrastructural methods. The patients were a 73-year-old man and 65-year-old man. A postoperative histological examination of the resected stomach of each patient disclosed large areas of an undifferentiated carcinoma which were relatively well demarcated from areas of the adenocarcinoma. In the undifferentiated carcinomatous areas, the reticulin fiber stain was epithelial in pattern, and mucin staining proved negative. Similarly both Grimelius and Fontana-Masson staining also negative. In like manner immunostains using cytokeratin , vimentin , IgG, IgA, s-100 protein, and NSE were all negative, and an electron microscopic study showed no neurosecretory granules or mucin secretory granules. Based on these findings, the diagnosis of either a malignant lymphoma or small cell anaplastic carcinoma could be excluded, and thus an undifferentiated carcinoma was the determination.

Adenocarcinoma↗
PubMed1989

Accumulation of ceramide in ischemic human brain of an acute case of cerebral occlusion.

An increase of ceramide, which is the major component of sphingolipids, was found in the ischemic human brain of an acute case of internal carotid artery occlusion. Amide-linked fatty acids in the ceramide isolated from the ischemic human brain were mostly non-hydroxy fatty acids, such as stearic acid (66.9%) and palmitic acid (20.2%). Other long-chain fatty acids, C24:0 and C21:1, were rare components in the ceramide. The ceramide contained C-20 sphingosine, and the ratio of C-20 to C-18 was 0.13. These findings indicate that an ischemic insult accelerates the degradation of gangliosides and causes an accumulation of ceramide in the ischemic human brain.

Aged↗
PubMed1989

[Combination chemotherapy with ifosfamide, 5-fluorouracil, cisplatin for stage D2 prostatic cancer].

Twelve patients with stage D2 adenocarcinoma of the prostate were treated with the combination chemotherapy of ifosfamide (2 g/body, i.v., day 1-3), 5-fluorouracil (250 mg/body, i.v., day 1-5) and cisplatin (20-30 mg/body, i.v., day 1-5). The averaged age was 62 years (from 52 to 73 years) with mean performance status of 70% (from 40 to 90%). Six patients were refractory to prior hormone therapy or chemotherapy and the other six had received no prior treatment for prostatic cancer. Based on criteria of National Prostatic Cancer Project, 4 patients achieved partial response (PR) which was maintained from 11 to 23 months with the mean of 17.8 months. Two patients achieved objectively stable stage (NC). Response rate (PR + NC) was 50%. Response rate of patients without prior therapy was 80%, whereas that of hormone-resistant group was 30%. There was a trend toward unfavorable response in patients with prior therapy. Adverse effects were mild to moderate gastric problems and myelosuppression except in one case Adverse effects were mild to moderate gastric problems and myelosuppression except in one case with low performance status under 60%. IFP combination chemotherapy achieved favorable responses and toxicities were tolerable. Therefore, it appears worth while to study whether IFP combination chemotherapy could extend the life of patients with advanced prostatic cancer.

Adenocarcinoma↗
PubMed1987

[Early combined carcinoma and malignant lymphoma in the stomach associated with tonsillar malignant lymphoma--report of a case].

This report deals with a histologic demonstration of a combined tumor of early signet ring cell carcinoma and lymphoma of the stomach in a 52-year-old Japanese man. The Gastric carcinoma was found by a systemic work up for a tonsillar lymphoma. The relationship between the malignant lymphomas of the stomach and of the tonsil is not clear in this case. The carcinoma and lymphoma of the stomach were both small, and the depth of invasion was localized to the mucosa and submucosa, respectively. The lymphoma was observed just beneath the cancer and was a diffuse, large cell type, and of the same histologic typing as the tonsillar lymphoma. Based on the broader size of the carcinoma, it is considered that the carcinoma probably induced the lymphoma in the stomach. This of an early combined tumor of carcinoma and lymphoma of the stomach is, to our knowledge, the first to be reported in the literature.

Adenocarcinoma, Mucinous↗
PubMed1987

[Surgical indication for extracranial-intracranial arterial bypass determined by cerebral blood flow study and neurological function--a retrospective study].

In order to establish more strict and objective indication for EC-IC bypass, a retrospective study on the surgical effect on cerebral blood flow (CBF) and neurological function was carried out in 37 cases. STA-MCA bypass was carried out on 20 cases with IC occlusion and 17 cases with MCA occlusion. Twenty-two cases with completed stroke, 9 cases with TIA and 6 cases with RIND. All patients were able to ambulate before surgery, and none of them were hemiplegic. CBF study by 133Xe inhalation method was carried out before and 2 to 4 weeks after surgery. Bypass was patent in all cases. Thirty percent of all cases showed more than 16% increase in CBF (++ group) on the side of bypass surgery and another 30% demonstrated 6 to 15% increase (+). On the other hand 30% of cases appeared to be unchanged (+/-), and 10% showed more than 6% decrease (-). The less the pre-operative CBF value was, the more the post-operative CBF was expected to be increased. Patients with pre-operative CBF less than 60% of normal value (ISI = 63 +/- 4) showed remarkable increase (++), and those with 60 to 70% showed moderate increase (+). Contrarily, cases with more than 70% of normal value showed either no change or decrease. Neurological change was evaluated as to disappearance of TIA attack and improvement of hemiparesis or mental dysfunction. Seventy-seven percent of patients in groups with (++) and (+) effect on CBF showed improvement in neurological function, whereas only 27% of patients in groups with (+/-) and (-) effect demonstrated improvement, which was statistically significant.(ABSTRACT TRUNCATED AT 250 WORDS)

Brain↗