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Biomedical subjects

K Shima

Publications and source records attributed to K Shima.

At least 361 records · Page 20Linked to original sources
PubMed1986

Markov-dependency and spectral analyses on spike-counts in mesencephalic reticular neurons during sleep and attentive states.

Spontaneous activities of the mesencephalic reticular formation (MRF) neurons of head-restrained cats were recorded to investigate their dynamic properties during sleep and waking. The Markov-dependency and spectral analyses were performed on the time series of counts converted from the MRF spike-train. During slow-wave sleep (SWS), MRF neurons fired with low Markovian properties and had a similar spectral-density curve as white noise; during paradoxical sleep (PS), their firing pattern showed high Markovian properties owing to low-frequency fluctuations, with spectral densities inversely proportional to frequency (the l/f spectrum). During the attentive state of bird watching (BW), intermediate Markovian properties were observed. These results confirmed both the rest theory of SWS and the activation of the brain during PS from the viewpoint of dynamic information-processing. Furthermore, the activation of the brain during PS may be greater than in BW.

Animals↗
PubMed1986

Glucagon-degrading activity in acid-ethanol extract of rat submandibular gland.

To investigate whether immunoreactive glucagon really exists in salivary gland, the integrity of glucagon radioimmunoassay was tested in the acid-ethanol extract of rat submandibular gland. Though immunoreactive glucagon was apparently measured in acid-ethanol extract of rat submandibular gland, the extract contained a significant amount of intact glucagon-degrading activity. The apparent % bound in radioimmunoassay highly correlated with the degradation of [125I] glucagon during incubation. Gel filtration profiles of [125I] glucagon incubated with acid-ethanol extract were the same as those of [125I] glucagon damaged by submandibular acid-saline extract. These data suggest that the immunoreactive glucagon in acid-ethanol extract is, as in the case of acid-saline extract, an artifact due to degradation of [125I] glucagon during radioimmunoassay.

Animals↗
PubMed1986

Absence of growth hormone response to L-dopa and bromocriptine in hyperprolactinemic women with pituitary microadenoma.

The administration of an amino acid precursor of both dopamine and norepinephrine, L-dopa, or of a dopamine agonist, bromocriptine, did not alter basal GH secretion in hyperprolactinemic women with pituitary microadenoma, whereas both significantly increased serum GH levels in normal women. The findings cannot be accounted for by decreased pituitary GH reserve, since in hyperprolactinemic women, insulin elicited an increase in GH levels similar to its action in normal women. Thus, the mechanism by which L-dopa or bromocriptine stimulates GH secretion appears to be different from that of insulin.

Adenoma↗
PubMed1986

Parallelism in the luteinizing hormone responses to opioid and dopamine antagonists in hyperprolactinemic women with pituitary microadenoma.

Endogenous opiate peptides are considered to inhibit LH secretion via a dopaminergic mechanism, and increased opioid inhibition of LH secretion has been found in some hyperprolactinemic women with a pituitary microadenoma. To assess the role of endogenous dopaminergic tone in the opioid regulation of LH secretion in such patients, LH responses to an opioid antagonist (naloxone) and a dopamine antagonist (metoclopramide) were determined in 11 women with a prolactinoma. Neither naloxone nor metoclopramide administration induced any change in serum LH levels in normal women during the early follicular phase. In contrast, 7 of the 11 hyperprolactinemic women responded to both antagonists with a significant increase in LH levels. The parallelism in the LH responses to both antagonists in these hyperprolactinemic patients lends further support to a functional link between opioid and dopamine regulation of LH secretion.

Adenoma↗
PubMed1986

Interindividual variation in the absorption of glibenclamide in man.

To investigate the interindividual variation in the absorption of sulphonylureas and its relation to unexpected hypoglycaemia during therapy with these drugs, serum concentration profile of glibenclamide, as well as plasma glucose and insulin response after an oral intake of glibenclamide were studied in 17 patients with non-insulin-dependent diabetes mellitus. In 12 patients glibenclamide was rapidly absorbed, reaching a peak concentration of 138.0 +/- 15.8 ng/ml (mean +/- SEM) at about 2 h. However, in 5 patients the absorption of glibenclamide was delayed and reached a serum peak of 134.1 +/- 29.5 ng/ml at later than 4 h. This delayed absorption was reproducible. There were no significant differences in age, duration of diabetes, per cent of ideal body weight, fasting plasma glucose or HbA1C between the rapid absorption group and the delayed group. However, autonomic nerve function, assessed by coefficient of variation of R-R intervals, was significantly impaired in the latter group in comparison with the former. Plasma glucose and insulin response to glibenclamide was also delayed in the delayed absorption group.

Absorption↗
PubMed1986

[Combination chemotherapy for bronchogenic carcinoma based on cell type].

Based on the cell types in bronchogenic carcinoma, we treated 123 patients with different regimens of combination chemotherapy. The chemotherapy regimens consisted of CAP (cyclophosphamide + adriamycin + platinum) for 60 patients with adenocarcinoma and large cell carcinoma, PP (peplomycin + platinum) for 29 patients with squamous cell carcinoma and CAV (cyclophosphamide + adriamycin + vincristine) for 35 patients with small cell carcinoma. These regimens were repeated every 4 weeks for at least 2 cycles. The response rates for CAP, PP and CAV were 18.3% (11 PR), 20.7% (6 PR) and 60% (10 CR + 11 PR), respectively. Median survival time (MST) was 12.5 months for CAP, 8.5 months for PP and 9.5 months for CAV. Responders had a significantly (P less than 0.002) improved survival (MST, 15.5 months) compared to non-responders (MST, 7.5 months) in small cell carcinoma. However, there was no significant difference between responders and non-responders in CAP and PP. Survival of patients with PS 0-1 was significantly better than that with PS 2-3 in all treated patients. Nausea and vomiting were severe in patients treated with platinum-based polychemotherapy. There was no renal failure although a transient increase of serum creatinine was noted in CAP and PP. Myelosuppression was mild to moderate in all patients treated with CAP, PP and CAV.

Adenocarcinoma↗
PubMed1986

[A phase II study of etoposide (VP-16) injection in primary lung cancer by cooperative study group].

A Phase II Study of VP-16 was performed in 58 patients with primary lung cancer. VP-16 was administered via infusion at a dosage of 60-100 mg/m2 daily for 5 days, and repeated every 3 to 4 weeks. Of the 58 patients who entered into the study, 38 were evaluable. Partial response was observed in 6 patients who had been diagnosed as having small cell carcinoma of the lung. Response rates were 15.8% for all evaluated patients and 33.3% for the patients with small cell carcinoma of the lung. As for dose-limiting toxicity, leukopenia (less than 3,000/mm3) was observed in 53.1% of cases. Other major adverse reactions were hematologic toxicities such as anemia and thrombocytopenia, gastrointestinal toxicities and alopecia, but these were all well tolerated.

Adenocarcinoma↗
PubMed1986

Determination of urinary lysozyme for potential detection of tubular dysfunction in diabetic nephropathy.

Seeking to study whether measurement of lysozyme (EC 3.2.1.17) in urine by a reliable radioimmunoassay can provide a suitable index of renal tubular function and how lysozymuria develops in temporal relation to proteinuria in diabetic nephropathy, we have compared the urinary excretion of lysozyme and beta 2-microglobulin with the 15-min excretion rate of phenolsulfonphthalein in 39 patients with Type 2 (non-insulin-dependent) diabetes and investigated the temporal relation between the onset of lysozymuria and proteinuria in 15 patients with Type 1 (insulin-dependent) diabetes. The concentrations of lysozyme and beta 2-microglobulin in urine increased in proportion to the decrease in the rate of excretion of phenolsulfonphthalein in these patients. The coefficient of correlation between lysozyme concentration and the 15-min excretion rate of phenolsulfonphthalein (r = -0.70) was higher than that between beta 2-microglobulin concentration and the 15-min excretion rate of phenolsulfonphthalein (r = -0.46). Abnormally high lysozymuria, suggesting the existence of tubular dysfunction, was demonstrated in six of the patients with Type 1 diabetes who showed no proteinuria or only a slight increase in urinary protein excretion. Lysozymuria may thus be added to a list of the indicators for diabetic nephropathy.

Adolescent↗