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Biomedical subjects

T Seki

Publications and source records attributed to T Seki.

At least 523 records · Page 29Linked to original sources

Mechanism of LH release in cultured rat pituitary cells.

To investigate the mechanisms of the synthesis and the release of gonadotropin, rat anterior pituitary cells were stimulated in vitro with luteinizing hormone releasing hormone (LH-RH), [D-Ser(tBu)]6 des-Gly-NH2(10) ethylamide (Buserelin) and 12-0-tetradecanoyl phorbol-13-acetate (TPA), and then the LH and LH-beta subunit released into the medium were determined by radioimmunoassay. Buserelin showed its biological activity at a much lower concentration than LH-RH, but both of them caused the release of LH and LH-beta subunit in a dose-dependent manner. Furthermore, intracellular LH synthesis from LH-beta subunit by stimulation with LH-RH or Buserelin was also found. After inducing various degrees of desensitization by stimulation with LH-RH or Buserelin in a dose-dependent manner (the first stimulation), pituitary cells were stimulated with a fixed dose of TPA (the second stimulation) and the released LH was assayed. LH was released almost constantly by the second stimulation, regardless of the dose used for the first stimulation. These results suggest that the C-kinase pathway was unaffected by the desensitization induced with LH-RH or Buserelin.

Animals↗

[A six-month chronic dietary toxicity study of pyriproxyfen in rats].

Groups of 21 male and 21 female Sprague-Dawley (SD) rats were fed diets containing pyriproxyfen at concentrations of 0, 80, 400, 2,000 and 10,000 ppm for 6 months. No death was found in any group. Alopecia in the neck and/or back, and soft feces were noticed in both sexes fed 10,000 ppm. A marked decrease in body weight gain was observed in both sexes fed 10,000 ppm throughout the treatment period, accompanying a decrease in food-consumption and an increase in water-intake during the initial stage of treatment. In terms of urinalysis, proteinuria, increases in K excretion, and, in number, yellowness or browish-yellowness in appearance, were observed in both sexes fed 10,000 ppm. In females fed 10,000 ppm, increases in bilirubin, Na excretion and specific gravity, and a decrease in ketone bodies, were observed. In hematology, decreases in erythrocyte count, hemoglobin concentration and hematocrit value, were observed in both sexes fed 10,000 ppm and in males fed 2,000 ppm. Also, an increase in MCH (in males), decreases in MCHC and platelet count (in females) were observed in 10,000 ppm group. Blood biochemistry revealed increases in total protein, albumin, alpha 2-globulin fraction, blood urea nitrogen, calcium (in both sexes fed 10,000 ppm), A/G ratio (in males fed 2,000 and 10,000 ppm), total cholesterol, phospholipid (in males fed 2,000 and 10,000 ppm, and in females fed 10,000 ppm), sodium (in females fed 2,000 and 10,000 ppm), gamma-glutamyl transpeptidase activity (in males fed 10,000 ppm) and alpha 1-globulin fraction (in females fed 10,000 ppm), and decreases in glucose, GOT (in both sexes fed 10,000 ppm), beta-globulin fraction (in males fed 2,000 and 10,000 ppm, and in females fed 10,000 ppm), GPT (in females fed 2,000 and 10,000 ppm), triglyceride, potassium (in males fed 10,000 ppm), and cholinesterase activity (in female fed 10,000 ppm). In organ weight, increases in liver (in males fed 2,000 ppm and 10,000 ppm, and in females fed 10,000 ppm), kidney (in both sexes fed 10,000 ppm) and thyroid (in females fed 10,000 ppm) and a decrease in pituitary (in females fed 2,000 and 10,000 ppm) were observed. Gross pathology revealed a higher incidence of blackish-brown coloration of the liver, and a lower incidence of accentuated lobular pattern of the liver (in males fed 10,000 ppm). An enlargement of the liver was seen in a few of both sexes fed 10,000 ppm. Histopathological examination showed that the sole effect attributable to treatment of this compound was on slight hypertrophy in the liver of both sexes fed 10,000 ppm, with a higher incidence.(ABSTRACT TRUNCATED AT 400 WORDS)

Administration, Oral↗

Changes in levels of mucosal glycoprotein on cysteamine-induced duodenal ulcers in rats.

Duodenal ulcers were induced in rats by cysteamine administration. Time-course changes in duodenal hexosamine, blood flow and intragastric pH were measured, as well as changes in the susceptibility of Brunner's glands to concanavalin A (Con A) staining. Hexosamine contents in the duodenum decreased significantly at 5 and 24 h. In the control group, Brunner's glands were stained brown using Con A staining. One day after cysteamine administration, the extent of Con A staining markedly decreased. At 3 and 7 days, gland susceptibility to staining was essentially the same as that of the control group.

Animals↗

[Effect of subgingival plaque control by direct irrigation technique--2. Clinical and microbiological changes after irrigation with acrinol or benzalkonium chloride solution].

The aim of the study was to evaluate the effect of the subgingival plaque control by direct irrigation. Twelve adult patients with periodontal pockets of 4 mm or more received an initial treatment. The patients were followed by irrigation using the device called Pocket Irrigator PT-01 with 0.05% acrinol solution or 0.025% benzalkonium chloride solution. The clinical and microbiological parameters were recorded prior to the irrigation and immediately after, at 1 hour, 1 day and 1 week after the irrigation. The Plaque Index, Gingival Index, gingival crevicular fluid and probing depth were used as clinical parameters. Samples of the subgingival plaque were collected with sterilized paper points from the periodontal pockets. The samples were examined by dark field microscopy with the Petroff-Hauser counting chamber with a magnification of 1,500x. The total number of bacteria and the proportion of the motile rods and spirochetes of the pockets were examined. All clinical parameters showed no significant changes after the irrigation. Intracrevicular irrigation by both acrinol and benzalkonium chloride solution significantly reduced the relative number of bacteria and the percentage of spirochetes/motile rods, when compared to those before the irrigation on day 1, though the differences did not persist on day 7. Thus, only by the single irrigation of the deep pockets with acrinol or benzalkonium chloride, the beneficial effects did not appear to continue clinically and microbiologically for a week.

Acridines↗

[Experience of the parenchyma saving procedure in the surgical management of renal cell carcinoma].

The result of renal conserving procedures for the surgical management of renal cell carcinoma experienced in 10 patients was reported. All except two were afflicted with tumor involvement in both kidneys (four cases) or in the solitary functioning kidney (four cases). The tumor stage was I in 8 and IV in 2 patients. One of the stage IV patients died of metastatic disease 8 months postoperatively. Of the 9 patients, 8 remained free of cancer in the follow-up period, while one who received an enucleative surgery and whose pseudocapsule of the tumor was missing had a local recurrence. Four of the 5 tumors having no pseudocapsule or having an invasion in the pseudocapsule were grade 2 or 3. The renal conserving surgery is believed to yield an excellent control in low grade and low stage tumors. Partial nephrectomy, rather than simple enucleation, remains to be a preferred surgical treatment in parenchyma-sparing operation, although the enucleative surgery may have a good indication for multiple and central encapsulated tumors.

Adult↗

[Conservative surgery of upper urinary tract urothelial carcinomas].

In the last ten years 19 patients with urothelial cancer of the upper urinary tract underwent excision of the tumor with preservation of the ipsilateral kidney. Renal function was preserved well in all cases in 31 months of the mean follow up term. In the presence of a normal contralateral kidney, local tumor excision was done electively in 12 patients (5 lower portion of ureter, 5 low grade lesions, 2 high age), local recurrence developed 6-63 months after operation in 2 patients, and they underwent nephroureterectomy. 11 cases are alive with no evidence of disease and one is alive with contralateral renal pelvic cancer. Absolute indications for conservative surgery were solitary kidneys/non functioning contralateral kidney in 3 patients and bilateral tumor in 4 patients. Most tumors were high grade or high stage (6: grade 2,4: PT2). No one had local recurrence, but one had a metastasis to a lung, 4 were suffering from bladder cancer post-operatively. Three patients died from cancer 20-30 months after operation. Local excision of urothelial cancer should be considered not only for cases of contralateral damaged kidneys but also for low grade, low stage localized tumors. Precise preoperative evaluation of tumors using a ureteroenoscope should be made for the indication of the renal preservative operation.

Adult↗

Ultrasonically guided percutaneous ethanol injection therapy for hepatocellular carcinoma.

Ultrasonically guided percutaneous ethanol injection therapy (US-PEIT) was performed in 26 patients with hepatocellular carcinomas (HCC) in whom neither surgery nor transcatheter arterial embolization (TAE) was indicated, or TAE had proved ineffective. Comparison of results by various diagnostic imaging techniques with histopathological findings revealed that tumor necrosis after US-PEIT was correlated with increased echogenicity of the tumor by US, decreased density of the tumor and disappearance of contrast enhancement by computed tomography (CT), and change to a lower signal in the tumor by magnetic resonance imaging [MRI, 0.15 T permanent magnet, spin-echo sequence, repetition time (TR)/echo time (TE) = 2000/80 ms]. Thus, findings by imaging are useful in evaluating the initial effect of US-PEIT. Of three specimens obtained by liver resection and three obtained at autopsy, four showed complete necrosis after US-PEIT (maximum tumor diameter, 3 cm). This method also appeared to be effective in cases of capsular invasion. In this study, the 2-yr survival rate of patients with HCC was 75%. Although this study was not a controlled clinical trial, we conclude that US-PEIT may be a potentially effective treatment for HCC.

Administration, Cutaneous↗

[The effect of chemical sympathectomy on the cell kinetics of gastric mucosa in golden hamsters].

The effects of chemical sympathectomy on the differentiation of the generative cells, superficial epithelial cells and gastrin cells of the gastric mucosa of hamster were examined by 3H-thymidine autoradiography. The labeling indices of the generative cell zone in the gastric mucosa and antral gastrin cells showed a transient significant decrease after chemical sympathectomy, and then they were gradually restore with time. After 4 weeks onward, the labeling indices of the generative cells showed a slightly low value compared with those in controls. The renewal of superficial epithelial cells and gastrin cells was examined in the hamster sympathectomized for 4 weeks. The time required for the differentiation to PAS positive superficial epithelial cells or gastrin cells had a tendency to elogate after chemical sympathectomy. These results suggest that chemical sympathectomy played an inhibitive action on the proliferation and the differentiation of gastric mucosa.

Animals↗

Validity of MR imaging for monitoring effects of percutaneous ethanol injection for HCC.

Magnetic resonance (MR) images of 44 hepato-cellular carcinoma (HCC) patients who had undergone percutaneous ethanol injection therapy (PEIT) were analyzed during and after the treatment. Using a long TE/TR spin-echo technique, the initial high intensity of the tumor decreased during treatment in all patients. Decrease in tumor intensity corresponded well with decrease of serum alpha-fetoprotein level and histopathological changes of the necrosis. During the long-term follow-up of three patients, the reappearance of a highly intense area was readily detected by MR imaging, and hence the recurrence of the tumor, as determined clinically or histopathologically, was confirmed. The long TE/TR spin-echo technique proves most helpful in monitoring the effectiveness of PEIT for HCC, as well as for its recurrence.

Carcinoma, Hepatocellular↗

A case of the watery diarrhea-hypokalemia-achlorhydria syndrome: successful preoperative treatment of watery diarrhea with a somatostatin analogue.

A 35-year-old man presenting with severe watery diarrhea was diagnosed as having the watery diarrhea, hypokalemia and achlorhydria (WDHA) syndrome with the elevation of plasma vasoactive intestinal peptide (VIP) level. Imaging diagnostic techniques revealed a hypervascular tumor at the tail of the pancreas as well as a solitary liver metastasis. During the patient's stay in hospital, he developed acute renal failure probably due to persistent dehydration and severe hypokalemia. Although these complications improved with artificial dialyses, severe watery diarrhea continued, which made it difficult to achieve surgical resection of the tumor. A new long-acting and potent somatostatin analogue, SMS 201-995 (Sandoz Ltd, Basel, Switzerland), was tested and was shown to be effective; after a few hours of subcutaneous injection of this agent, the watery diarrhea disappeared, which in turn improved the patient's hypokalemia, hypercalcemia and metabolic acidosis. Three weeks later, distal pancreatectomy with splenectomy and hepatic lobectomy were successfully performed, and the patient resumed his normal life. The somatostatin analogue has been reported to be useful in the long-term treatment of patients with inoperable WDHA syndrome. The present case demonstrated that short-term administration of this agent is also useful for improving the condition of WDHA patients at the preoperative stage.

Adenoma, Islet Cell↗

[The usefulness of 99mTc-PMT cholescintigraphy in the diagnosis of bile leakage or biloma].

5 cases (6 lesions) of bile leakage or bilomas were experienced. All cases showed high accumulative areas in the lesions of bile leakage using 99mTc-PMT cholescintigraphy, while US and CT studies showed no specific findings of fluid-filled areas. Cholescintigraphy demonstrated communications between the injured biliary systems and other spaces very clearly. Even if the needle aspiration failed to get a characteristic bile, which were sometimes seen in bilomas complicated with infection or bleeding, cholescintigraphy was useful for the accurate diagnosis. It is also useful for monitoring the bile drainage.

Aged↗

[Two cases of infantile subungual pigmented nevi with Hutchinson's sign].

Two cases of subungual pigmented nevi with periungual melanotic freckles, namely Hutchinson's sign, are presented. They are a 4-year-old female and a 11-month-old male; in neither case did the mother notice the lesion at birth. Histologically, both cases were characterized by the presence of well-circumscribed small nests of nevus cells in the periungual melanotic areas; diagnoses of junctional nevus and compound nevus were made, respectively. However, atypical proliferations of melanocytes at the dermo-epidermal junction of the nail matrix and nail bed were observed in some areas. The measurement of the DNA content of melanocytes by means of microfluorometry revealed normal diploid pattern in the former case, but the latter case contained a few aneuploid cells, suggesting that the proliferating melanocytes might have malignant potentials. Infantile subungual pigmented nevi with Hutchinson's sign must be examined thoroughly and watched carefully.

Aneuploidy↗

[Coronary artery bypass surgery with internal mammary artery grafts: clinical and angiographic results].

We report clinical and angiographic results of coronary artery bypass grafting (CABG) surgery in 307 patients. IMA grafts can be utilized in the wide ranges of patient ages and/or coronary lesions including left main trunk disease, and have good adaptive capability to coronary flow demand with very low probability of atherosclerotic changes. Postoperative (5.2 +/- 4.4 months) patency rates for IMA grafts and SVG were 96% and 86%, respectively; a significant difference (p less than 0.001). From the benefits of this graft, the use of IMA has become a routine procedure in our CABG surgery and the rate of multiple bypasses with IMA grafts has increased recently. The late cardiac events have significantly (p less than 0.05) decreased in patients with the IMA graft than in those without it. We believe that the use of IMA has improved the quality of CABG in Japanese patients and this operative modality can bring better late results than multivessel PTCA.

Adolescent↗