Biomedical subjects
K Tajima
Publications and source records attributed to K Tajima.
Independent protective effect of lactation against breast cancer: a case-control study in Japan.
A case-control study was carried out to assess the risk of breast cancer associated with breast feeding in Japan. The data were obtained in a hospital-based case-control study of 521 women with breast cancer and 521 controls from January 1988 to December 1989. Statistical adjustment for potential confounders as well as a likelihood ratio test for linear trend was done by unconditional logistic regression. Compared with parous women who had never breast-fed, women with a positive history of breast feeding had an odds ratio of breast cancer of 0.62 (95% confidence interval 0.37-1.04). The trend of decreasing risk with increasing average months of breast feeding was statistically significant (chi 2 trend = 4.5, p less than 0.05), while it was was nonsignificant for the number of breast-fed children borne. Among premenopausal women, a significant linear relation with a log-transformed term of average months of breast feeding was noted, regardless of the age of the woman at first full-term pregnancy and parity (chi 2 trend = 5.3, p less than 0.05). The risk was the lowest among premenopausal women who had ever lactated for 7-9 months (adjusted odds ratio = 0.39, 95% confidence interval 0.15-0.97). These findings suggest that lactation has an independent protective effect against breast cancer in Japanese women.
Failure to detect HTLV-I by in situ hybridization in the biopsied muscles of viral carriers with polymyositis.
Direct infection of muscle fibers by human T-lymphotropic virus type I (HTLV-I) has recently been reported in a patient with polymyositis infected with both HTLV-I and human immunodeficiency virus (HIV). Coinfections of these viruses are frequently found in the United States. In Kagoshima, Japan, patients with polymyositis have a significantly increased incidence of seropositivity to HTLV-I alone, when compared with the general population of Kagoshima. In this study, we examined muscle tissue from 6 HTLV-I-positive patients with polymyositis from Kagoshima. To detect HTLV-I products, sensitive immunohistochemistry and in situ hybridization analysis were performed. These were compared with muscle fibers from a well-characterized transgenic mouse model which expressed HTLV-I tax. No specific signals were detected in the biopsied muscles of patients with polymyositis infected with HTLV-I alone. HIV co-infection may, therefore, augment HTLV-I expression through either immunosuppression or direct viral interactions.
Uveitis associated with human T lymphotropic virus type I: seroepidemiologic, clinical, and virologic studies.
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A case of Lafora disease diagnosed by skin biopsy.
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A rare case of perineal pain: intestinal perforation caused by a press-through package.
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Synthesis of (S)-N-[methyl-11C]nicotine and its regional distribution in the mouse brain: a potential tracer for visualization of brain nicotinic receptors by positron emission tomography.
A nicotine agonist, 11C-labeled (S)-nicotine, was synthesized by N-methylation of (S)-nornicotine with [11C]-methyl iodide in dimethylformamide-dimethylsulfoxide in order to study nicotinic receptors in the human brain by positron emission tomography. The radiochemical yield of this N-methylation reaction was more than 90% within 5 min. After purification by high performance liquid chromatography the radiochemical purity of the product was more than 99% and the specific radioactivity was 7.4-11.1 GBq/mumol. The regional distribution of (S)-[11C]nicotine in the mouse brain after intravenous injection was compared with that of (R)-[11C]nicotine. After injection of (S)-[11C]nicotine, the regional uptake of radioactivity was in the following order: cortex greater than thalamu approximately hippocampus greater than striatum greater than hypothalamus greater than cerebellum. Moreover, (S)-[11C]nicotine was displaced from the brain by unlabeled (S)-nicotine, but unlabeled (R)-nicotine caused no change in uptake. In contrast, (R)-[11C]nicotine showed a lower brain uptake and lesser regional differences in radioactivity.
Progressive spastic paraparesis associated with human T-cell leukemia virus type I (HTLV-I).
Patients with progressive spastic paraparesis (PSP), commonly middle-aged women, are distributed throughout the country of Chile. During the three years from 1987 to 1990, we collected 83 cases of PSP from among 225 patients with various neurological diseases. The clinical picture was of a bilateral pyramidal syndrome, with sensory deficits in only 15.5% of the cases, and a slow illness progression in the majority of them. In patients with PSP, antibody to human T-cell leukemia virus type I (HTLV-I) was analyzed by enzyme linked immunosorbent assay (ELISA) and confirmed by western blot analysis. Forty-five (54.2%) patients were anti-HTLV-I antibody positive in cerebrospinal fluid (CSF) and peripheral blood. Among them, 2 patients had leukemia/lymphoma and one had Sjögren syndrome. In the laboratory study of seropositive PSP, mononuclear pleocytosis was found in 35.7%; there was an abnormal increase of the IgG index in 66.6% and an increase in CD2 in blood and CSF, and CD4 in blood. A delayed latency of somatosensory evoked potentials was observed in 90.9%. The neuropsychological study revealed a WAIS with a mean verbal IQ of 80.7 and a mean performance IQ of 84.8. The most impaired items were digit symbol and digit span. Seven subjects (18.9%) with anti-HTLV-I antibody were found among 37 relatives from 19 anti-HTLV-I positive cases of PSP.
Changing patterns of cancer mortality among the elderly population in Japan.
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Intracellular calcium changes induced by alpha 1-receptor stimulation in guinea-pig vas deferens.
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[An epidemiological evaluation of the efficacy of mass screening for uterine cancer in Japan. The relationship between coverage rate of mass screening and reduction in death rate from uterine cancer].
To evaluate the efficacy of mass screening for uterine cancer, the relationship between the coverage rate of mass screening and the reduction in mortality rate from uterine cancer was analyzed. The percent change in the AADR (Age-adjusted death rate) from 1979-1983 to 1984-1988 were compared between the high coverage rate areas and the control areas with relatively lower coverage rates, and among the high coverage rate areas with varied coverage rates. The main results were: (a) the decreases of AADR from uterine cancer were greater in three groups of high coverage rate areas than in control areas with low coverage rates. (b) Among three groups of high coverage rate areas with variation in coverage rates (> or = 20%, > or = 30%, > or = 40%), the higher the coverage rate was, the greater was the percent reduction (-45.9%, -52.3%, -63.5%) of AADR. These results suggest that systematic mass screening may be effective in reducing mortality from uterine cancer.
Prediction of future cancer mortality in Japan.
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Feasibility study on quality-of-life questionnaires for patients with advanced lung cancer.
In order to evaluate quality-of-life (QOL) questionnaires, we studied the reliability and validity of the self-rating forms: A, comprising 16 questions; B, comprising 39 questions (Table II and III), in a special study supported by the Ministry of Health and Welfare. Sixty-four patients with inoperable lung cancer and 50 patients with chronic, non-malignant disease were entered into the study. Form A was translated and modified to Japanese culture from Schipper's Functional Living Index-Cancer, and Form B was of our own design. The internal consistency of the forms was examined by Cronbach's alpha coefficient. Both forms except for aspects of physical and social concern on form B, had alpha values greater than 0.65. A concurrent validity with performance status was shown over all aspects of concern (Pearson's correlation, r greater than 0.27, P less than 0.05) except for social (forms A and B) and psychological (form B). Analysis of variance of the QOL scores revealed significantly lower scores for the cancer patients than for the non-malignant-disease patients, except for the social aspect of concern (P less than 0.001). Factor analysis, using the principal component method, identified four major factors to account for 60 and 42% of the total variance on forms A and B, respectively. The factors were: patient's mood, anxiety over disease and treatment, relationships with other people, physical capability. In conclusion, this has been the first feasible study to show that QOL forms from the West could be used in Japan with some modifications. We are at present studying successive changes in QOL for advanced lung cancer patients in clinical trials.
[A case of ectopic ureter with renal dysplasia simulating epididymal structure].
A 30-year-old man was admitted to our hospital suffering from fever and left scrotal swelling. Physical examination revealed an enlarged left epididymis, suggesting acute epididymitis. Intravenous pyelography showed non-functioning left kidney. On cystoscopy, the left ureter orifice did not open in the bladder, and it opened in the posterior urethra. An ureteral catheter was passed through this orifice to about 5 cm length and retrograde injection of contrast material demonstrated a dilated left ureter. CT also confirmed a dilated left ureter behind the bladder and the left kidney was not found. Left nephroureterectomy was performed. Microscopically, normal renal tissue was not recognized, and the lesion comprised a number of ducts covered with tall columnar epithelium having stereocilia and ducts resembling the thyroid gland. The former ducts resembled the ducts of epididymis. The pathological diagnosis was total dysplasia.
[Surgical treatment of acquired tricuspid stenosis].
There is no definitive surgical procedure for acquired lesions of the tricuspid valve (TV). From Feb, 1978, through March, 1990, the surgical treatment for the organic lesions of TV was performed in 10 patients, repair in 6 and TV replacement in 4. TV was repaired by commissurotomy, annuloplasty or valvuloplasty, or combination of them. When residual significant tricuspid regurgitation (TR) and/or stenosis (TS) was detected by intraoperative pulsed Doppler echocardiography after reparative procedures, TV was replaced. Follow-up periods ranged from 1 to 12 years (mean, 45.3 months). There was no early death, and late death was noted in one patient 32 months after operation. Preoperatively, 7 patients were in NYHA class IV and 3 in class III. Out of survivors, 7 are in class I and 2 in class II because of progression of mitral stenosis or coronary artery disease. Following surgery, the patients exhibited significant decrease in the cardiothoracic ratio (69.3 +/- 7.2 to 56.9 +/- 6.4%; p less than 0.01) and in the mean right atrial pressure (11.4 +/- 3.6 to 8.6 +/- 3.1 mmHg; p less than 0.05). The postoperative right ventriculography showed mild to moderate TR in 3 of 6 patients who underwent TV repair. In conclusion, TV repair could be a reasonable procedure for the organic TV lesions, although careful follow-up is recommended for residual TR.
[Operative management of Stanford type A aortic dissection using selective cerebral perfusion].
Ten patients underwent surgical treatment for type A aortic dissection from October 1986 to April 1989 using hypothermic cardiopulmonary bypass (CPB) with selective cerebral perfusion (SCP). CPB was begun with femoral artery cannulation. The right axillary artery (RAA) and the left common carotid artery (LCCA) were separately cannulated and perfused with CPB blood by individual pump heads. The average flow to the RAA was 5.4 +/- 1.2 ml/min/kg body weight (mean +/- SD) and 5.6 +/- 2.6 ml/min/kg body weight to the LCCA. The average blood pressure of the superficial temporal artery was 53.1 +/- 15.1 mmHg in the right side and 52.5 +/- 24.7 mmHg in the left. The nasopharyngeal temperature during SCP was maintained at 19.3-24.7 degrees C (mean, 21.1 degrees C). The SCP time ranged from 112 to 197 minutes (mean, 168 +/- 20.8 minutes). There was one operative death. She died of myocardial infarction 3 days after operation. There were two late deaths. One patient died of infection 3 months after operation and another died of cholecystitis 4 months after operation. Cerebral infarction developed in the last patient. Among the 10 patients it was only one neurological sequela, which was surmised to be caused by technical problem in carotid artery cannulation. The good cerebral protection was obtained in our experience by SCP as mentioned above.
Overcoming of vinblastine resistance by isoquinolinesulfonamide compounds in adriamycin-resistant leukemia cells.
We investigated the effects of seven isoquinoline derivatives in overcoming resistance to vinblastine in Adriamycin-resistant mouse leukemia P388/ADR cells and human myelogeneous leukemia K562/ADR cells. N-(2-Methylpiperazyl)-5-isoquinoline-sulfonamide (H-7), N-[2-(methylamino)ethyl]-5-isoquinolinesulfonamide (H-8), and N-(2-aminoethyl)-5-isoquinolinesulfonamide (H-9) did not reverse resistance to vinblastine in these resistant cells. N-[2-[N-[3-(4-Chlorophenyl)-2-propenyl]amino]ethyl]-5- isoquinolinesulfonamide (H-86) and N-[2-[N-[3-(4-chlorophenyl)-1-methyl-2-propenyl]- amino]ethyl]-5-isoquinolinesulfonamide (H-87) caused significant accumulation of intracellular vinblastine and marked reversal of the resistance to vinblastine in both resistant cell lines. Addition of a formyl group at the terminal amino group of H-86 (H-85) or addition of an aminoethyl group to the nitrogen atom at the sulfonamide group of H-86 (W-66) reduced those activities. The activity on vinblastine accumulation seems to correlated with the hydrophobicity of the compounds. The compounds that effectively reversed resistance to vinblastine inhibited [3H]vinblastine efflux and photoaffinity labeling of P-glycoprotein with a photosensitive analogue of vinblastine, N-(p-azido-(3-[125I]iodo)-salicyl)-N'-beta-aminoethylvindesine. Although these isoquinoline derivatives inhibited protein kinase A and protein kinase C with various potencies, these inhibitory activities did not correlate with the reversal of drug resistance. These results indicate that hydrophobic isoquinoline derivatives reverse multidrug resistance due to the suppression of drug binding to P-glycoprotein, without involvement of their activities on protein kinase A and protein kinase C.