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Biomedical subjects

K Nakada

Publications and source records attributed to K Nakada.

At least 163 records · Page 9Linked to original sources
PubMed1989

Effect of endogenous opioid peptides on TRH release from rat stomach in vitro.

The effect of endogenous opioid peptides (beta-endorphin, leucine-enkephalin, dynorphin 1-13 on the release of thyrotropin releasing hormone (TRH) from the rat stomach in vitro was studied. The rat stomach was incubated in the medium 199 with 1.0 mg/ml of bacitracin (pH 7.4) (medium) and the amount of TRH released into the medium was measured by radioimmunoassay. The release of TRH from the rat stomach was inhibited significantly in a dose-related manner with the addition of endogenous opioid peptides, but not affected with naloxone. However, the inhibitory effect of endogenous opioid peptides on TRH release from the rat stomach was prevented by the addition of naloxone. These findings suggest that endogenous opioid peptides inhibit TRH release from the rat stomach in vitro.

Animals↗
PubMed1989

[Effect of induced hypotension on damage to renal tubular cells].

Urinary excretion of renal tubular cell enzymes, N-acetyl-beta-D-glucosaminidase (NAG) and gamma-glutamyl transpeptidase (gamma-GTP) was evaluated to elucidate the renal cell damage before, during and after the induced hypotension with trimetaphan (TMP), nitroglycerin (TNG) and prostaglandin E1 (PGE1) under halothane-nitrous oxide-oxygen anesthesia in patients undergoing neurosurgery. Significant increases in excretion of NAG and gamma-GTP were observed in TNG group. Urinary excretion of these two enzymes in TMP group tended to increase, but its increases were not statistically significant. In PGE1 treated group, there was no tendency for urinary NAG excretion, while gamma-GTP excretion tended to decrease compared with that observed before the induced hypotension. Among these three drugs, TNG exerted the most significant effect on urinary excretion of both enzymes and TMP ranked next. Effect of PGE1 on urinary enzyme excretion was weakest. According to the general opinions, degree in stray of renal tubular cell enzyme into urine is thought to parallel with the injury of renal tubular cells. Therefore, the finding obtained in this study suggests that the induced hypotension with PGE1 has a less harmful effect on renal tubular cells.

Acetylglucosaminidase↗
PubMed1988

Polyclonal integration of HTLV-I proviral DNA in lymphocytes from HTLV-I seropositive individuals: an intermediate state between the healthy carrier state and smouldering ATL.

We have studied 15 individuals (aged 14-74 years) with antibodies to HTLV-I in their serum and random integration of HTLV-I proviral DNA in their peripheral blood lymphocytes. All but one of these patients suffered from a variety of non-specific complaints which did not correspond to those of adult T-cell leukemia (ATL). All of them were born in Kyushu and Okinawa which are endemic areas for HTLV-I infection; 25% of their family members were also seropositive for HTLV-I. The only haematological abnormality in these patients was the presence of few atypical lymphoid cells in the peripheral blood. The CD4/CD8 ratios were normal but the proportion of Tac positive cells was slightly higher than normal. These individuals with polyclonal integration of HTLV-I proviral DNA seem to represent an intermediate state between smouldering ATL (monoclonal integration) and healthy HTLV-I carriers (with antibodies but no detectable HTLV-I proviral DNA). Patients with this intermediate state of HTLV-I infection may be at risk to progress to ATL. The natural history of HTLV-I infection in humans leading to the development of ATL is reviewed in the light of these new findings.

Adolescent↗
PubMed1988

[The effect of vagotomy and gastrectomy on the lower esophageal sphincter motility].

The motor activity of the canine lower esophageal sphincter (LES) was studied under conscious states by means of the strain gage transducer, and gastroesophageal reflux was investigated after injection of the contrast medium through the silastic tube inserted in gastric fundus by x-ray. The motor activity and function of LES were observed in the dogs with selective proximal vagotomy (SPV), truncal vagotomy (TV) and TV + gastrectomy. Results were summarized as follows; 1. In the postprandial period, so called receptive relaxation was observed in gastric body, and tonic contraction was observed in LES. On the other hand, the occurrence of the LES contraction was consistent with gastric periodic motor activity in the interdigestive state. It was found that such a contractile pattern of LES and gastric body prevented the reflux of gastric juice from stomach to esophagus in the digestive and interdigestive state. 2. In the postprandial period, the tonic contraction of LES was inhibited by the venous injection of atropine sulfate. Mechanisms of digestive contractile activity of LES were mainly regulated by cholinergic nerve. 3. After SPV and TV, the motility of LES and gastric body was disturbed. Namely, receptive relaxation disappeared, and tonic contraction was observed in gastric body, but the relaxation of the LES was found after ingestion. These findings suggested that discordant LES contractiles with the contraction of the gastric body after vagotomy produced a gastroesophageal reflux. 4. After TV + gastrectomy, the synchronous motor activity of the LES, remnant stomach and duodenum disappeared. Namely, it was thought that the reflux esophagitis occurred after gastric surgery with vagotomy and lymphnodes dissection was caused by the duodenal juice reflux to remnant stomach and esophagus.

Animals↗
PubMed1988

[A study on senile postural deformity].

One hundred and twenty-eight aged people were divided into four groups to elucidate the mechanism of senile spinal deformity: extended type, S-shaped type, flexed type and hand-on-the-lap type. Except for S-shaped type, the major cause of anterior stooping of the spine was lumbar disc degeneration. The paraspinal muscles prevent anterior stooping. In case the muscles cannot compensate the anterior stooping, the spine can be taken back straight by posterior pelvic tilting. Posterior pelvic tilting is obtained by extension of the hip joint and flexion of the knee joint. Knee flexion up to 25 or 30 degrees serves to correct this pelvic tilting, but can cause patellofemoral osteoarthritic changes. When the knee of an aged person exceeds this angle, the individual will assume hand-on-the-lap posture. In aged people spinal deformity is thus compensated by the lower extremity. The spine and lower extremity should be regarded as a single musculoskeletal unit.

Aged↗
PubMed1987

Monoclonal integration of HTLV-I proviral DNA in patients with strongyloidiasis.

The relationship between strongyloidiasis and HTLV-I was investigated in Okinawa, an area where both conditions are endemic. Thirty-six patients with strongyloidiasis were seropositive for HTLV-I and suffered from several related clinical complications. Fourteen of these patients (39%) were shown to have monoclonal integration of HTLV-I proviral DNA in their blood lymphocytes, a condition designated as "smouldering" adult T-cell leukaemia (ATL). Monoclonal integration of proviral DNA correlated with an increased CD4/CD8 ratio and the presence of abnormal lymphocytes in the peripheral blood, and with a trend for greater severity of the parasitic infection. Although the immunodeficiency caused by HTLV-I could predispose to hyperinfestation by Strongyloides, it is also possible that both the parasitic and the retroviral infestations are important co-factors leading to the development of ATL.

Adult↗
PubMed1987

Biological characterization of interleukin-1-like cytokine produced by cultured bone cells from newborn mouse calvaria.

We have investigated the role of interleukin-1 (IL-1) and IL-1-like factor in the regulatory mechanisms of a bone remodeling system. To determine whether the bone cell itself produces IL-1-like cytokine, we examined bone cells cultured from newborn mouse calvaria. Bone cells migrating from fragments of newborn mouse calvaria were used in this study. We also used bone cells obtained by consecutive digestion of the calvaria with enzymes. These bone cells were cultured in fetal calf serum-containing alpha-MEM. IL-1-like cytokine activity was measured by incorporation of [3H]thymidine into C3H/HeJ thymocytes stimulated with PHA. When treated with lipopolysaccharide (LPS) from Escherichia coli 0111 B4, the cultured bone cells produced a significant amount of IL-1-like cytokine. The maximum concentration of IL-1-like cytokine was observed in culture supernatants of the bone cells cultured for 24 hours with the LPS in serum-free medium. The IL-1-like cytokine closely resembles IL-1 in some of its biological characteristics: stimulation of mitogen-induced thymocyte proliferation, stimulation of fibroblast proliferation, pyrogenicity, and molecular weight. These results show that cultured bone cells from newborn mouse calvariae produce an IL-1-like cytokine that closely resembles IL-1.

Animals↗
PubMed1986

Chromosomal abnormalities in a patient with smoldering adult T-cell leukemia: evidence for a multistep pathogenesis.

A cytogenetic study was performed on peripheral blood cells from a patient with smoldering adult T-cell leukemia (ATL). Four types of primary abnormal clones were found upon examination of a large number of karyotypically analysed cells cultured with and without phytohemagglutinin (PHA). However, human T-cell leukemia virus (HTLV) proviral DNA was confirmed to be monoclonal. This discrepancy can be explained by the hypothesis that these four primary abnormal clones were all derived from a leukemic clone with a normal karyotype and the same integration site of HTLV proviral DNA.

Chromosome Aberrations↗