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Biomedical subjects

M Wada

Publications and source records attributed to M Wada.

At least 577 records · Page 32Linked to original sources
PubMed1986

Participation of the dnaK and dnaJ gene products in phosphorylation of glutaminyl-tRNA synthetase and threonyl-tRNA synthetase of Escherichia coli K-12.

The heat shock proteins DnaK and DnaJ of Escherichia coli participate in phosphorylation of both glutaminyl-tRNA synthetase and threonyl-tRNA synthetase. When cellular proteins extracted from the dnaK7(Ts) and dnaJ259(Ts) mutant cells labeled with 32Pi at 42 degrees C were analyzed by two-dimensional gel electrophoresis, no phosphorylation of these proteins was observed when they were compared with those from wild-type cells.

Amino Acyl-tRNA Synthetases↗
PubMed1986

Different mechanisms controlling FSH and LH release in Japanese quail (Coturnix coturnix japonica): evidence for an inherently spontaneous release and production of FSH.

Plasma concentration of FSH and LH and their content in the adenohypophyses of Japanese quail were estimated by homologous radioimmunoassays based on chicken hormones. The results consistently showed that the plasma concentration of FSH was slightly higher than that of LH, although the FSH content in the adenohypophysis was much lower than that of LH in immature, mature and acutely photostimulated quail. These results prompted experiments in vitro to determine whether the difference was intrinsic. Adenohypophyses were collected and each cut mid-sagittally into two halves; one half was incubated for 20 h with or without chicken hypothalamic extract, and the medium was changed every 1 or 2 h to estimate the FSH and LH released. The other half served to estimate the initial content of FSH and LH in the adenohypophysis. The amount of FSH released was three times more than the original content even when adenohypophyses were incubated without hypothalamic extract, and the residual FSH content in the pituitary after 20 h of incubation was equal to the initial FSH content. In contrast, under the same incubation conditions, little LH was released and the residual LH content was decreased. When hypothalamic extract was added to the medium, LH release was enhanced sixfold compared with the control, whereas the increase in FSH was less than twofold. Spontaneous FSH release was markedly decreased in a Ca2+-deficient incubation medium, suggesting that the release was not due to leakage but to an active secretion mechanism.(ABSTRACT TRUNCATED AT 250 WORDS)

Age Factors↗
PubMed1986

[Evaluation of T-2588 in the treatment of respiratory tract infection].

T-2588 was used on 55 patients with respiratory tract infections and 44 cases were evaluated; 23 patients with pneumonia, 12 patients with acute bronchitis, 2 patients with chronic bronchitis, 1 patient with diffuse panbronchiolitis and 6 patients with bronchiectasis with infection. Clinical effects of T-2588 were as follows; excellent in 6 and good in 28 patients. The efficacy rate was 77.3% (34/44). Bacteriological effects of T-2588 were prominent in 8 patients infected with B. catarrhalis, H. influenzae, K. pneumoniae and E. coli, but not in a patient infected with P. putida. The elimination rate was 90.0% (9/10 strains). As side effects, stomatitis, anorexia, diarrhea X vomiting and pruritus were observed in one patient each. Abnormal laboratory findings were observed in 4 patients with elevated GOT and/or GPT. These side effects and abnormal laboratory findings were not serious. The usefulness of T-2588 was 68.2% (30/44). Therefore, T-2588 is a useful drug and its effects are promising in clinical management of respiratory tract infections.

Administration, Oral↗
PubMed1985

Molecular cloning and nucleotide sequence of the HU-1 gene of Escherichia coli.

The Escherichia coli HU-1 was cloned by use of mixed synthetic oligonucleotides (17-mer) predicted from a portion of its amino acid sequence. The amino acid sequence of the HU-1 protein deduced from the nucleotide sequence is in good agreement with the published sequence. The nucleotide sequence has a possible promoter and a typical ribosomal binding site upstream from the translational initiation codon (GUG) of the HU-1 gene.

Amino Acid Sequence↗
PubMed1985

Transplacental induction of myeloschisis associated with hindbrain crowding and other malformations in the central nervous system in Long-Evans rats.

Nine groups of 66 pregnant rats, grouped by gestation days 11 to 19, were subjected to a single, intragastric administration of ethylenethiourea (ETU). Cesarean section was performed on gestation day 20. No dam died following the ETU treatment, although a mortality as high as 21.2% was noted among the fetuses in this group; the remaining live fetuses were found to suffer from a high incidence of myeloschisis associated with hindbrain crowding. Exencephaly and abnormally enlarged head with occipital bossing due to the herniation of the mesencephalic tectum, with and without dilation of the mesencephalic and 4th ventricles, were induced among the fetuses of the dams given ETU at gestation days 12 and 13. Various degrees of hydranencephaly and dysplastic hydrocephalus were found among the fetuses of dams treated by ETU from gestation days 14 to 18. From the histological features of these malformations of the central nervous system (CNS), a possible mechanism in the induction of myeloschisis with hindbrain crowding induced by ETU is discussed, and compared with the previously reported similar malformations induced by trypan blue.

Abnormalities, Multiple↗
PubMed1985

Retinal modulation of the hypothalamic sensitivity to testosterone feedback in photoperiodism of quail.

This experiment was performed on two groups of male Japanese quail. One had been maintained in our laboratory as a closed colony (S-group), and the other had been obtained from a commercial source (R-group). Different responses of gonadal function were found between two groups following either testosterone treatment or exposure to short days. Immature birds of these groups responded to long days with rapid gonadal growth, but after sexual maturity, exposure to short days for 3 weeks induced testicular atrophy only in S-group. Involvement of the feedback effect of androgen in the photoperiodic response was then examined. Under long-day conditions, intraperitoneal placement of testosterone propionate (TP)-filled Silastic tube for 2 weeks decreased testicular weights in S-group but not in R-group. Apparently, sensitivity to short days is closely correlated with sensitivity to testosterone in the adult male. By bilateral enucleation, quail of S-group became less sensitive to both gonad inhibitory effect of short days and the negative feedback effect of TP. These results suggest that the photoperiodic mechanisms that are primarily mediated by the retinal system play a role in altering sensitivity to steroid feedback at the hypothalamus.

Animals↗
PubMed1985

Effects of chicken (Gln8)- and mammalian (Arg8)-luteinizing hormone-releasing hormones on the release of gonadotrophins in vitro and in vivo from the adenohypophysis of Japanese quail.

Both chicken luteinizing hormone-releasing hormone (Gln8-LH-RH) and mammalian luteinizing hormone-releasing hormone (Arg8-LH-RH) increased the release of FSH and LH from adenohypophysial halves of adult male Japanese quail when the halves were incubated in a medium containing LH-RH. Elevation of the FSH release was less marked than that of the LH release irrespective of the LH-RH species. A pulse stimulation (10 min) of adenohypophysial halves with chicken as well as mammalian LH-RH in vitro resulted in a burst of both FSH and LH release. The increment of the FSH release was smaller than that of the LH release. A single intravenous injection of each LH-RH to adult male quail induced rapid increases of plasma FSH and LH levels within 5 min. The plasma levels of FSH and LH returned to their initial levels at varying times after the injection depending on the dose of LH-RH. Again, the increment of the FSH level was smaller than that of the LH level, showing a similar profile to the in vitro pulse stimulation experiment. No significant difference in ability to stimulate FSH and LH secretions from the quail adenohypophysis was detected between chicken and mammalian LH-RHs under either in vivo or in vitro conditions, whereas chicken LH-RH has been reported to be far less potent than mammalian LH-RH when tested on the rat adenohypophysis.

Animals↗
PubMed1985

Transient glucose intolerance during attacks of thyrotoxic periodic paralysis.

In a 19-year-old Japanese male (case 1) with thyrotoxic periodic paralysis (TPP), an increase of plasma glucose concentration together with abnormally high levels of serum immunoreactive insulin (IRI) was observed preceding a spontaneous attack of paralysis. Therefore, the plasma glucose, glucagon, epinephrine, norepinephrine, serum IRI, growth hormone and cortisol levels, and the erythrocyte insulin receptors were measured in case 1 and a 40-year-old Japanese male (case 2) with TPP during attacks of paralysis induced by prolonged glucose loading. In case 1, the serum IRI concentration was elevated to the extraordinarily high level of 655.0 microU/ml at the beginning of paralysis, and at that time, the plasma glucose concentration was 147 mg/dl. However, when paralysis was not induced by a similar glucose loading during methimazole treatment, the serum IRI and plasma glucose levels at the corresponding time after glucose loading were 20.9 microU/ml and 87 mg/dl, respectively. Furthermore, the affinity of the erythrocyte insulin receptors was decreased during the attack. In case 2, plasma glucose and serum IRI concentrations were increased in accordance with the initiation of paralysis although the blood levels of hormones counteracting insulin were not significantly changed. These findings suggest that there is something interacting with the normal action of the insulin in the early phase of paralysis.

Adult↗
PubMed1985

Cellular mechanisms in in vivo production of gamma interferon induced by lipopolysaccharide in mice infected with Mycobacterium bovis BCG.

Infection of mice with Mycobacterium bovis BCG sensitizes them for immune induction of interferon (IFN)-gamma by specific antigen. These mice were found also to respond to lipopolysaccharide (LPS) and concanavalin A (Con A) with high level production of IFN-gamma in the circulation, which was not observed in control mice. In this study, we compared the IFN-gamma response to LPS with that to Con A in an attempt to clarify the cellular mechanisms responsible for in vivo LPS-induced IFN-gamma production. Consequently, (i) the responses to LPS and Con A differed in the kinetics, that to LPS having a longer lag period. (ii) Spleen cells taken from infected mice produced little IFN-gamma in response to LPS, but they showed a higher IFN-gamma response to Con A than those from control mice. (iii) By treating infected mice with immunosuppressive drugs or antibodies to T and natural killer cells before challenge with the inducers, it was indicated that different cellular systems are involved in the IFN-gamma responses to LPS and to Con A.

Animals↗