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Biomedical subjects

I Nakamura

Publications and source records attributed to I Nakamura.

At least 271 records · Page 15Linked to original sources

Correlation between month of menarche and month of birth.

The month of menarche and month of birth were studied in 47,218 women who were born during a period of 90 years between 1881 and 1970. Among those born prior to 1960, there was a tendency for menarche to occur more frequently at the month of birth. This coincidence was not, however, found among those born after 1960.

Delivery, Obstetric↗

Alternate changes in birth seasonality of twins during 1971-1984 in Japan.

Birth dates of 1,536 twin-pairs in 1971-1984 were collected from the members of an association of twins' mothers. The seasonal variation of twinning changed every 2-4 years. Years when twinning rate was higher in the summer-fall season (1971-72, 1976-77, 1982-84) and those when a peak of the rate was not observed (1973-75, 1978-81) appeared alternately. In years with a summer-fall peak, the elevation of twinning in the summer-fall season was detected consistently in both like- and unlike-sexed and in both MZ and DZ twin groups. The twinning seasonality in these years, however, was not evident in twin births of mothers who were born in May-July. These results suggest the possibility that seasonal factors which influence the twinning rate be not multiple-ovulation-inducing but probably abortion-inducing factors and most likely seasonally epidemic microbes.

Abortion, Spontaneous↗

Serial polysomnograms in Creutzfeldt-Jakob disease.

This is a report of the case of a patient with Creutzfeldt-Jakob disease, whose electroencephalograms and polysomnograms were repeatedly recorded throughout the course of the illness with details of the alterations of periodic synchronous discharges. In the advanced stage of the disease, the appearance of peculiar paroxysms was noted, predominantly in the early morning. Furthermore, apnea of the central type was observed during the same time period. Discussions were held on the mechanisms inducing the EEG paroxysms and apneas.

Cerebral Cortex↗

Cell-mediated immunity caused by beryllium compounds.

Cells of spleen and lymph nodes were obtained from mice subcutaneously injected with BeCl2 once a week over a 6-week period. These cells were washed twice in cold phosphate-buffered saline and suspended at a final concentration of 2 x 10(7) cells in 1 ml of buffer. Subsequently, 0.5 ml of the suspension was injected into normal mice intravenously (passive transfer). The findings of the experiments using these mice are summarized as follows: (1) The footpad reaction test was performed 24 hrs after passive transfer. The mice receiving spleen cells or lymph node cells from mice sensitized with BeCl2 developed significant footpad swelling 24 and 48 hrs after challenge of BeCl2 as the antigen. (2) After passive transfer with sensitized spleen cells or lymph node cells the ears of the mice were painted with 7% BeCl2 in ethyl alcohol. Ears of these mice showed significant swelling as compared with those of controls. (3) The migration of peritoneal cells from mice receiving spleen or lymph node cells from sensitized mice was inhibited when tested in medium containing the antigen of BeCl2. From our present experiments, it was suggested that the beryllium sensitizing ability was related to active as well as passive cell-mediated immunity.

Animals↗

[Immunological study of beryllium workers].

Immunological health surveys of Beryllium (Be) workers in a copper-beryllium casting factory were made 10 times during the 5-year period from 1981 to 1985. The total number of Be workers was 150. 1) Macrophage migration inhibition test was performed by an agarose plate method using Be as antigen with peritoneal cells from guinea pigs and small amounts of Be worker's blood. We found that 1 out of 22 healthy Be workers (4.5%) that migration index (MI) was below 80% after 24 h and 5 (22.7%) after 48 h. The mean of MI in Be workers showed significant low value as compared with that of the control group (p less than 0.01). 2) It was found that the serum complement titer tended to be lower in Be workers than in the control group. The serum complement titer of 3 to 6 subjects showed to be less than 30 U/ml every survey. 3) Although a few showed the abnormal levels in serum immunoglobin (IgG, IgA and IgE), the means of these immunoglobin levels were not markedly changed and they were in the normal ranges, respectively. 4) MI values significantly correlated with IgE level in Be workers, that is y= -8.9 x + 997.8 (r = -0.473, p less than 0.05). These results suggest that macrophage migration inhibition test and serum complement titer were of value for assaying of sensitivity to Be and immune responses in Be workers.

Beryllium↗

[A study of the use of methotrexate, vincristine, cis-platinum, cyclophosphamide, adriamycin, bleomycin (MVP-CAB) in metastatic transitional cell carcinoma].

Eight patients with metastatic transitional cell carcinoma of the urinary tract were treated with the MVP-CAB regimen. All of them had bidimensionally measurable lesions. The MVP-CAB regimen consisted of cyclophosphamide 500 mg/m2, methotrexate 20 mg/m2, adriamycin 20 mg/m2, bleomycin 30 mg/body, and vincristine 1 mg/body on day 1, cis-platinum 50 mg/m2 on day 2, and prednisolone 20 mg/body on days 1-3, given every 3-4 weeks. A partial response was seen in five patients, minor response in one patient and no change in two patients. The response rate was 63% (5/8). The main toxic effect of the MVP-CAB regimen was leucopenia. In 75% of the patients there was a decrease in white blood cell count by not more than 2,000/mm3, but no severe complication was noted. In addition, mild nausea, vomiting, mild anorexia, alopecia and fever were found. However, these symptoms were transient. One patient died of pulmonary fibrosis induced by bleomycin after 3 cycles.

Adult↗

["Saving-effect" of stimulating pulses at low-frequency limbic kindling in cats].

To assess the development of kindling effect induced with low frequency electrical stimulations, we stimulated the lateral amygdala (AM group, 5 cats) and the dorsal hippocampus (HP group, 5 cats) bipolarly, once a day, with 2 mA base to peak, biphasic 1 msec square-wave pulses. In each stimulation we measured the longest inter-pulse interval required for the provocation of epileptic afterdischarge (AD), defined as the pulse-interval threshold; and the number of stimulating pulses required for the provocation of AD at this pulse-interval, defined as the pulse-number threshold. The observed behavioral seizures were classified into 6 stages in both the AM and HP group according to the conventional classification. In the AM group, an increase of the pulse-interval threshold and a decrease of the pulse-number threshold were observed during the kindling process. At the completion of kindling, a generalized convulsion was provoked with 1,200-1,600 msec pulse-intervals, and with 8-12 stimulating pulses. In the HP group an increase of the pulse-interval threshold and a decrease of the pulse-number threshold were observed in the early seizure stages, but not so significantly as the AM group. In the late seizure stages, a decrease of the pulse-interval threshold and an increase of the pulse-number threshold were observed. The observed behavioral stage of seizures in the two groups were similar to that of the conventional high-frequency kindling.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

[Fundamental study of piperacillin sodium in term and premature neonates].

Piperacillin sodium (PIPC) is a semisynthetic penicillin displaying high antibacterial activities against Gram-positive and Gram-negative bacteria including Pseudomonas sp., Proteus sp., etc. It acts bactericidally and is stable against beta-lactamases. The usefulness of PIPC in the treatment of infections in mature and premature neonates was investigated and the following results were obtained. The pharmacokinetics (half-life, distribution volume, total body clearance) of PIPC after 50 mg/kg intravenous drip infusion in 10 cases of neonates were examined. Relationship between T1/2 and hours after birth was clearly determined. Adverse effects and abnormality in laboratory test values were not observed. It is considered from the above results that PIPC may be an useful antibacterial agent for the treatment of infections in neonates.

Acute Disease↗

[Sleep spindles and physical parameters].

In 4 identical (Nos. 1-4) and 3 fraternal (Nos. 5-7) male twin pairs (mean age, 16 years), sleep spindles were analysed during sleep. The height, body weight, plantar length and chest circumference were measured, and the correlations between sleep spindles and these physical parameters were examined. The physical parameters showed concordance between identical twin pairs except one pair (No. 4) and one fraternal pair (No. 5) but discordance between two fraternal twin pairs (Nos. 6 and 7). Number of sleep spindles and sleep spindle density showed almost concordance between identical twin pairs and one fraternal pair (No. 5), while discordance between two fraternal ones (Nos. 6 and 7). Both number of sleep spindles and sleep spindle density were inversely correlated with body weight (r = -0.61, p less than 0.02; r = -0.62, p less than 0.02). These facts would suggest that sleep spindles rather reflect the individual development than genetic trait.

Adolescent↗

Saving-effect of stimulating pulses at low-frequency amygdaloid kindling in cats.

Cats were stimulated in the lateral amygdala with low-frequency square-wave pulses. All subjects were kindled until generalized convulsion occurred. During the kindling process, a prolongation of the interpulse interval and a reduction of the number of pulses required for the provocation of afterdischarges were observed. We refer to this phenomenon as the 'saving-effect' of stimulating pulses to provoke afterdischarges.

Action Potentials↗

Suppression of murine NK activity induced by Corynebacterium parvum: further characterization and abrogation of suppressor cells.

Formalin-killed Corynebacterium parvum (CP), given at a dose of 0.4-0.7 mg/mouse IV or IP, induced suppressor cells for NK activity in B6C3F1 mice. The suppressor cells belong to at least two different populations, plastic adherent and nonadherent, and were not depleted by antibodies specific for Thy-1.2, Iak, or NK-1.2 surface markers. Administration of p-I:C, an interferon-inducer, to animals 18 h before the assay did not affect the suppressor activity. Hypotonic shock treatment of splenocytes abrogated the in vitro suppressive activity, and subsequent reconstitution of the shock-treated cells with RBC failed to restore the suppressive activity. SJL/J mice, which have low NK activity, exhibited suppressor activity comparable to B6C3F1 mice following CP treatment, whereas CP-treated BALB/c athymic and euthymic mice showed a lower ability to generate suppressors for NK as compared to B6C3F1 mice.

Animals↗

Low-frequency kindling as a new experimental model of epilepsy.

Ten cats were stimulated twice a day in the lateral amygdala with low-frequency stimulation of about 3 Hz until generalized convulsion occurred. After the completion of kindling, the longest interpulse interval required for provocation of generalized convulsion (pulse-interval threshold) was determined in each subject. The pulse-interval threshold was 1300 ms in five cats, and 900 ms in five other cats. Then the stability of pulse-interval threshold and of the number of stimulating pulses required for provocation of afterdischarge when the stimulation was delivered with the pulse-interval threshold (pulse-number threshold) was tested. The pulse-interval threshold, pulse-number threshold, and duration of afterdischarge in each stimulation did not change statistically at the interstimulation interval from 24 h to 7 days. Phenobarbital and diphenylhydantoin elevated the pulse-number threshold significantly. We propose that low-frequency kindling is a valuable experimental model of epilepsy in assessing simply and precisely the susceptibility of the epileptic focus itself and the severity of epileptic seizures.

Animals↗