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Biomedical subjects

S Kai

Publications and source records attributed to S Kai.

135 records · Page 8Linked to original sources

Immunological studies on myasthenia gravis: operative indication and cell-mediated immunity.

An important aspect of the management of patients with myasthenia gravis is the decision to recommend thymectomy. Hitherto, many investigators have reported the relationship between the operative effects and such factors as age, sex, duration of symptoms, or degree of germinal center proliferation in the myasthenic thymus. However, these reports are not practical aids in deciding the indication for thymectomy in an individual myasthenic patient. The currently accepted indications of thymectomy for myasthenic patients are (1) the thymomatous patient, especially those with malignancy, and (2) the nonthymomatous patients who are resistant to medical treatment. From our present data we would add the following as an indication of the operation: (3) patients who have high T-cell subpopulation levels with highly blastogenic activities and strong skin test reactivities. In order to assure good operative results in myasthenic patients, surgeons should examine their patients' preoperative immunological states.

Adolescent↗

Immunotherapy of cancer patients with Bacillus Calmette-Guérin: summary of four years of experience in Japan.

Active immunotherapy with living BCG was conducted on 98 patients with various types of cancer. The candidates for this therapy were patients with residual or inoperable cancer of the colorectum, liver, breast, biliary tract, lung, and other organs with a follow-up of 4-58 months. Eleven of the 98 (11%) were able to survive for as long as 37-58 months (mean survival time 42.5 months) because of this treatment and are still living. Another 11 patients are also alive more than 24 months after starting treatment. Thirty-seven patients, however, succumbed within 12 months despite BCG immunotherapy. On the other hand, 37 patients in the control group, who shared the same clinical status and did not receive BCG therapy during this period, underwent unhappy courses for 2-12 months (mean survival time 8.7 months). The pretreatment immunoresponsiveness of these 98 patients was suppressed, as measured by the following immunologic parameters: T-cell subpopulation in the peripheral blood, stimulation index of PHA, and skin tests to DNCB, KLH, PPD, and PHA. All of these parameters improved shortly after initiation of BCG injections in 22 patients who survived more than 24 months. In contrast, in patients who died within 12 months, immunoresponsiveness remained suppressed throughout the course. This result has suggested that there was an apparent correlation between the effectiveness of BCG and immunoresponsiveness. In addition, a good correlation was observed between the duration of inflammatory reactions at BCG injection sites and clinical prognoses. Moreover, it was shown that a relatively high amount of BCG (20-80 mg as an initial dosage) and repeated injections of living BCG were necessary to obtain a sufficient enhancing effect on the immunocompetency of these late-stage cancer patients. The most conventional criterion used to determine an optimal time for booster injections of BCG was measurement of the PPD-evoked skin reaction at the BCG injection site, that is, Koch's phenomenon. When a marked flare-up reaction of more than 2.5 X 2.5 cm in size was observed, the effect of BCG was considered to be continuing, and no additional booster injection was needed. The mean interval between the first and second BCG injections was 6.2+/-1.1 months in patients who survived more than 2 years. In contrast, the duration of this reaction was only transient in ineffective cases. The most frequent side effects of this therapy were fever and malaise; these complications occurred in 62% of the cases. No severe side effects, such as dissemination, anaphylactic shock, or granulomatous hepatitis, have been experienced throughout this study, even in patients to whom a total dosage of more than 200 mg of living BCG were injected.

Adult↗

Gastrointestinal stromal tumor arising in the rectovaginal septum.

We report herein a rare case of malignant gastrointestinal stromal tumor (GIST) originated from the rectal wall, which presented as a tumor on the rectovaginal septum. A 54-year-old Japanese woman, gravida 4, para 3, was admitted complaining of anuresis and severe constipation. She had a history of hysterectomy and right salpingo-oophorectomy for uterine leiomyoma 11 years previously. Pelvic examination revealed an 8.5 x 7.5 x 7.5 cm hard mass in the rectovaginal space. The inferior border of the tumor was 2 cm from the vaginal introitus and 2 cm from the anus. Computed tomography and magnetic resonance imaging showed a well-circumscribed soft-tissue mass filling the rectovaginal space. Urinary bladder and rectum were markedly compressed and displaced. Colon fiberscopy revealed invasion of the tumor into the rectal mucosa. An abdominoperineal resection of the rectum with posterior vaginal wall resection and pelvic lymphadenectomy was performed. The resected specimen showed a rectal submucosal tumor that was 8 x 8 x 7 cm in size. The tumor was diagnosed as a malignant GIST. Immunohistochemical analysis confirmed this diagnosis. The patient is now healthy without evidence of recurrence at 13 months after surgery. Gynecologists should be aware of rectal GIST arising in the rectovaginal space as a differential diagnosis of vaginal submucosal tumor.

Diagnosis, Differential↗

Influence of type II diabetes on arterial tone and endothelial function in murine mesenteric resistance arteries.

An arteriograph was used to assess myogenic tone, smooth muscle contractility and the influence of endothelial function on mesenteric resistance artery reactivity in insulin-resistant mice (C57BL/KsJ-db/db) and age- and gender-matched wild-type mice. Increases in transmural pressure induced myogenic tone in arteries from both control and db/db mice. At 12 and 16 weeks of age, greater tone developed in diabetic than in control mice. In control, but not in db/db mice, pretreatment of arteries with L-NAME potentiated myogenic tone. Indomethacin and SQ29548 (PGH2/TXA2 receptor antagonist) had no efffect in control, but inhibited myogenic tone in db/db mice. Endothelium-dependent vasodilation induced by acetylcholine and bradykinin, was depressed in db/db mice and potentiated by SQ29548 and LY333531 (protein kinase C(beta) inhibitor). Messenger RNA expression levels for PKC(beta) were over-expressed 2.5-fold in db/db relative to those in control mice. However, expression levels of mRNA for eNOS, PKC(alpha), and PKC(xi) were similar in the db/db and control mice. Collectively, these results suggest that the greater myogenic tone in resistance arteries from diabetic mice may be attributable, to greater amounts of one or more vasoconstricting prostanoids. Our data indicate that in diabetic mice, basal and agonist-stimulated NO releases are depressed and NO-mediated vasorelaxation in these mice may be countered by an endogenous vasoconstrictive prostanoid. This prostanoid-induced vasoconstriction is mediated by a PKC(beta)-dependent mechanism. Therefore, heightened activation of PKC(beta) and release of a vasoconstrictor prostanoid could play a role in endothelial dysfunction associated with type II diabetes.

Acetylcholine↗

Acceleration of gastric ulcer healing by omeprazole in portal hypertensive rats. Is its action mediated by gastrin release and the stimulation of epithelial proliferation?

BACKGROUND: Gastric ulcer healing is delayed in patients with portal hypertension (PHT) and often responds poorly to histamine H(2) blockers. Although proton pump inhibitors are more effective anti-ulcer agents, there is little information regarding their efficacy for gastric ulcer in cases of PHT. Therefore, we investigated the effects of a proton pump inhibitor, omeprazole, on the healing of acetic-acid-induced gastric ulcer in PHT rats. METHODS: Animals studied were 80 male Sprague-Dawley rats aged 7 weeks, of which half underwent two-staged portal vein ligation (PHT rats) and half underwent a sham operation (SO rats). Gastric ulcers were induced by acetic acid. Starting from day 4 after ulcer induction, rats received omeprazole or vehicle orally (50 mg/kg) for 5 or 10 days. Ulcer area, proliferating cell nuclear antigen labelling index (PCNA LI), and serum gastrin levels were recorded. RESULTS: PHT significantly inhibited epithelial cell proliferation and delayed gastric ulcer healing as indicated by a decreased PCNA LI at the ulcer margin and almost 2-fold larger ulcer area in PHT versus SO rats 14 days after ulcer induction. Ten-day treatment with omeprazole (vs. vehicle) significantly accelerated ulcer healing to a similar extent in both PHT and SO rats. Serum gastrin levels were significantly higher in PHT rats than in SO rats following treatment with omeprazole. Omeprazole (vs. vehicle) restored the decreased PCNA LI at the ulcer margin in PHT rats to that noted in SO rats. CONCLUSIONS: In PHT rats, omeprazole accelerates gastric ulcer healing, stimulates epithelial cell proliferation at the ulcer margin, and increases serum gastrin levels. Since gastrin is a potent stimulator of gastric epithelial cell proliferation, increased serum gastrin levels may be an important factor in omeprazole-induced stimulation of epithelial cell proliferation and acceleration of gastric ulcer healing in conditions of PHT.

Acetic Acid↗

Interstitial pneumonitis after allogeneic bone marrow transplantation following total body irradiation.

The records of 40 patients who received allogeneic bone marrow transplantation (BMT) at Hyogo College of Medicine under the same conditioning regimen using cyclophosphamide and total body irradiation (TBI) from January 1984 to August 1989 were analyzed. The dose rate of TBI was 10 cGy per minute, and the total dose was 10 Gy (2.5 Gy daily for 4 days). Interstitial pneumonitis (IP) occurred in 13 of 40 patients, and was fatal in five patients. The probability of developing IP during the first year was 31%. We performed univariate analysis on the following factors but did not find any significant risk factors for IP: age and sex of patient, sex mismatch, ABO mismatch, grade of acute graft-versus-host disease, post immunosuppression regimen, and number of marrow cells transfused.

Acute Disease↗

Total lymphoid irradiation and total body irradiation for allogeneic bone marrow transplantation in aplastic anemia.

Between April 1980 and June 1989, 15 patients with severe aplastic anemia (SAA) were treated at Hyogo College of Medicine with bone marrow transplantation (BMT) after preparation consisting of cyclophosphamide (CY) and total lymphoid irradiation (TLI) or total body irradiation (TBI) for the purpose of reducing the incidence of graft rejection. All patients had initial evidence of engraftment after the first transplantation except for one patient who died of heart failure due to CY on the third day after transplantation and could not be evaluated for engraftment. Rejection later occurred in four of these 14 patients, who then underwent successful regrafting. One of these patients, who was conditioned with CY alone at the first grafting, underwent successful regrafting after a conditioning regimen of CY and TBI. In the other three patients, irradiation was performed twice as the conditioning regimen. Thus, 14 of 15 patients underwent successful BMT and are alive with restored hematopoietic function. From the above results, the combination of TLI or TBI and CY was considered to be very useful as a conditioning regimen for BMT in patients with SAA.

Adolescent↗