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Biomedical subjects

M Kishida

Publications and source records attributed to M Kishida.

At least 91 records · Page 5Linked to original sources

Treatment of status asthmaticus--hormone changes before and after aminophylline i.v. drip therapy.

The treatment of status asthmaticus is one of the most important factors in controlling the patient with asthma attacks. We have studied hormone changes in status asthmaticus and considered what is the best treatment in the asthma attack condition in children. Antidiuretic hormone (ADH), renin activity, and aldosterone activity are elevated in severe asthma attack conditions, and these high levels are correlated with high levels in Wood's clinical score. It is theoretical that patients with dehydration and respiratory failure show such elevation in hormones, and it is well known that under such conditions beta 2-stimulant enhances renin production. From our study, it is concluded that beta 2-stimulant subcutaneous injection must be considered in status asthmaticus. In children, aminophylline i.v. drip therapy may be one of the best treatments in status asthmaticus.

Adolescent↗

Effects of dietary excess amino acids on the concentrations of cholesterol, alpha-tocopherol, ascorbic acid, and copper in serum and tissues of rats.

An experiment was conducted with growing rats to investigate the effects of feeding excessive specific L-amino acids for 8 days on serum and tissue cholesterol, alpha-tocopherol, ascorbic acid, and copper, and on liver microsomal cytochrome P-450. To a 10% casein diet were added 4% L-methionine, 5% L-cystine, 5% L-histidine, 5% L-threonine, 5% L-tryptophan, 5% L-phenylalanine, 5% L-tyrosine, 6% L-valine, 7% L-isoleucine, 7% L-lysine, or 8% L-leucine. Excessive cystine and histidine increased serum cholesterol and alpha-tocopherol. Excessive cystine and methionine increased liver and kidney alpha-tocopherol and ascorbic acid. Excessive tyrosine and phenylalanine caused a marked increase in serum copper and ceruloplasmin activity, whereas excessive cystine, methionine, and histidine caused a decrease in the ceruloplasmin activity. Excessive histidine increased liver cytochrome P-450, whereas excessive tyrosine markedly decreased liver cytochrome P-450.

Amino Acids↗

[Posture and circadian variations in serum theophylline concentrations].

We have reported that the morning mean rate of absorption (ka) in immediate release aminophylline tablet is significantly faster than the evening one without any obvious change in AUC, the distribution (Vd), the rate of elimination (kel) or the elimination half-time (t1/2) and this altered absorption is a cause of circadian variation of theophylline concentrations with sustained-release preparations. Now, we examined the effect of posture on theophylline absorption. Seven asthmatic children were given immediate release aminophylline tablets at the same time in the morning on two separate occasions. On one day they remained standing and on the other lying. Serum theophylline concentration was measured at 0, 0.5, 1, 2, 3, 4, 5 hours after dosing. Mean theophylline levels were higher in the standing position at all time and only the mean rate of absorption (ka) was significantly faster without any obvious change in parameters of pharmacokinetics. This result was almost consistent with differences of day and night theophylline kinetics. We conclude that slowness of absorption in the evening is mainly induced by difference in posture.

Adolescent↗

Effects of thyroid hormone and actinomycin D on phosphate uptake of brush-border membrane vesicles from kidney of rachitic rats.

It is generally accepted that 3,5,3'-triiodothyronine (T3) is responsible for most of the known physiological actions of thyroid hormone. Our new rachitogenic diets, deficient in both vitamin D and iodine and low in phosphorus (1.13% calcium and 0.14% phosphorus), induced typical rachitic changes in rats. To know the possible role of T3 on bone and phosphate (Pi) metabolism and its related biochemical and molecular mechanism, weanling male Wistar rats were fed this diet for 28 days, and then treated with 6 micrograms/100g BW of T3 and/or 60 micrograms/100g BW of actinomycin D intraperitoneally. After 2 hours of treatment, renal brush-border membrane vesicles (BBMV) were prepared according to the calcium precipitation method, and their Na(+)-dependent Pi uptake was analyzed by Lineweaver-Burk plots. Km value was not significantly altered by all these treatments. In contrast, Vmax value as a Pi uptake index was significantly increased in T3-treated rats compared with rachitic control. This increase was evident as less as 2 hr after T3 administration, so it was assumed that T3 stimulated the Pi uptake not by mediation of the de novo protein synthesis. However this increase was suppressed by administration of actinomycin D, and then this result suggests that the antirachitic effect of T3 is mediated by somehow de novo protein synthesis. After all, T3 acting as an antirachitic agent, the most likely possibility is that T3 provides favorable conditions for mineralization of bone by improving Pi transport in various types of cells, even under rachitogenic condition, at least of hypophosphatemic type, and correction of phosphate metabolism may be the most essential prerequisite for cure of this type of rickets.

Animals↗

The measurement of melanin-concentrating hormone in trout blood.

Two methods are described for measuring the titres of melanin-concentrating hormone (MCH) in trout plasma. One involves the extraction of MCH from 1-ml plasma onto C18 Sep Pak cartridges, after which the eluted peptide is measured by conventional radioimmunoassay. In the alternative method, antibodies are bound onto immunobeads which are added to 0.5 ml plasma. After incubation for 24 hr, the beads are washed to remove the plasma and are incubated with 125I-labelled MCH; the following day, the labelled beads are separated by centrifugation, washed, and counted. The relative advantages of each method is discussed. Using these two methods, it is shown that the plasma concentration of the hormone is significantly higher in fish from white tanks (greater than 50 pmol/litre) than in fish from black tanks (approximately 10 pmol/litre) or those kept in the dark (approximately 5 pmol/litre). The plasma concentration of MCH changes rapidly when trout are moved from one coloured background to another, indicating its involvement in physiological colour change.

Animals↗

Melanin concentrating hormone. IV. Development of a sensitive solid-phase radioimmunoassay for melanin-concentrating hormone.

A two-step solid-phase radioimmunoassay for melanin-concentrating hormone (MCH) was developed for direct determination of the hormone in plasma samples. To this end, synthetic MCH was coupled to bovine thyreoglobulin and the complex was injected into rabbits. Specific antisera of high titer were obtained which did not crossreact with other hormones. The IgGs were chemically linked to immunobeads, an acrylamide/acrylic acid polymer matrix. In the first step, plasma MCH was immunoextracted by incubation of diluted plasma samples with anti-MCH immunobeads. In the second step, the washed polymer was incubated with radioiodinated MCH tracer for titration of non-occupied sites. This procedure made it possible to determine as little as 4 pg MCH per ml of plasma. Application of the radioimmunoassay to plasma levels of black or white background-adapted trout showed a marked difference in circulating MCH: while trout on a black background contained a mean value of 29 +/- 5.6 pg/ml, animals on a white background had 106 +/- 19 pg/ml. These findings strengthen the hypothesis that MCH is directly involved in the control of color change of teleost fishes. By contrast, there was no detectable salmonid MCH immunoreactivity in rat or human plasma.

Animals↗

A case of exercise-induced anaphylaxis: evidence of an association with the complement system.

We studied a 17-year-old girl with exercise-induced anaphylaxis (EIA). She experienced 10 episodes of EIA which demonstrated cutaneous, digestive and cardiorespiratory symptoms. This subject exhibited elevation in plasma histamine (13.3 ng/ml) and decrease in CH50 (17 U/ml) and C3 (70 mg/dl) after naturally induced EIA. On remission day CH50 (26 U/ml), C3 (83 mg/dl) and C4 (15 mg/dl) were of relatively low values. Her mother demonstrated the same tendency with a low level of C4 (14 mg/dl), and this suggested an underlying genetic disorder in the complement system. Exercise challenge could not elicit EIA symptomatically but showed fluctuation of CH50. The triggering mechanism of EIA was unclear; however there is a possibility that complement plays an important role in EIA.

Adolescent↗

Localisation and identification of melanocyte-stimulating hormones in the fish brain.

The existence of melanocyte-stimulating hormone (MSH) in fish brains was investigated by a range of techniques: radioimmunoassay, HPLC, bioassay, and immunocytochemistry. Immunoreactive alpha MSH (ir alpha MSH) was detected by radioimmunoassay in all regions of carp and trout brains, with the highest concentration in the basal hypothalamus. In trout, ir alpha MSH cell bodies were located by immunocytochemistry only periventricularly, in the medial basal hypothalamus near the third ventricle, whereas in the carp ir alpha MSH staining was seen both in periventricular cells and also in some of the magnocellular neurones in the lateral hypothalamus. When white-adapted fish were transferred to a black tank for 6 days, the melanin-concentrating hormone (MCH) content of the basal hypothalamus of both carp and trout increased 2- and 4.6-fold, respectively, but the alpha MSH content did not change in either species. Analysis by HPLC of pituitary gland, hypothalamic, and optic tectal extracts revealed that the pituitary contains desacetyl, monoacetyl, and diacetyl alpha MSH, although the ratio of these forms differed in the two species. The hypothalamus and optic tectum, however, contained predominantly the desacetyl form of alpha MSH. Bioassays for MSH in the HPLC fractions revealed the existence of presumptive beta MSH in both the pituitary and hypothalamus. An argument is advanced that the periventricular ir alpha MSH neurones are homologous with the proopiomelanocortin cells of the arcuate nucleus in mammals, and that the immunocytochemical alpha MSH-like activity in the MCH neurones may not be authentic alpha MSH.

Animals↗

Prolactin and growth hormone secretion during long-term incubation of the pituitary pars distalis of mature chum salmon, Oncorhynchus keta.

The effects of hypotonicity of the medium on prolactin (PRL) and growth hormone (GH) release from the pars distalis (PD) of mature chum salmon pituitary were examined during culture for 4 days. Large amounts of PRL and GH were released during the first 6 hr and secretion decreased rapidly thereafter. The amounts of GH released as well as the residual content in PD were 10 times greater than those of PRL. There was no difference in PRL or GH release between the PD incubated in isotonic medium (325 mOsm) and those in hypotonic medium (250 mOsm) even during the first 6 hr. Female PD secreted more PRL than male PD during the first 6 hr, whereas a sex difference was not observed in GH release. Considerable amounts of both PRL and GH remained in the PD at the end of the culture period. The amount of PRL released during 4 days of culture from female PD (37-39%) was greater than that from male PD (23-26%), and the amount of GH released was less in females (28-32%) than that in males (53-54%). Release of PRL and GH appears to be mainly under stimulatory hypothalamic control in the mature chum salmon.

Animals↗

Isolation of two forms of growth hormone secreted from eel pituitaries in vitro.

Two forms of growth hormone (GH) were purified by chromatofocusing of medium from cultured Japanese eel (Anguilla japonica) pituitaries. The pituitaries were organ-cultured in Eagle's minimum essential medium with Earle's salts. Following polyacrylamide gel electrophoresis of the medium at pH 9.5, two prominent bands were seen with Rf 0.36 and 0.29; they were designated as eGHI and eGHII, respectively. Seven-hundred fifty milliliters of medium, in which 260 pituitaries were cultured for 6-10 weeks, was concentrated by DIAFLO membrane (YM-5) and subjected to gel filtration on a Sephadex G-75 column and to chromatofocusing on a PBE-94 column. eGHI and II were finally purified by gel filtration on a Sephadex G-75 column, yielding 2.0 mg of eGHI and 1.3 mg of eGHII. Both eGHI and eGHII were equipotent to ovine GH in promoting growth of juvenile rainbow trout. The putative GH-producing cells in the proximal pars distalis of the eel pituitary were stained specifically with antisera raised against eGHI or eGHII; no cross-reactivity was seen in the follicular prolactin cells in the rostral pars distalis. As determined by gel isoelectric focusing, eGHI and eGHII have isoelectric points of 6.3 and 6.7, respectively. Identical molecular masses of 23,000 Da were determined by sodium dodecyl sulfate gel electrophoresis. Their amino acid compositions strongly resembled each other; comparison of the partial N-terminal amino acids indicates that sequence 1 to 36 of GHII is exactly the same as 4 to 39 of GHI.

Animals↗

Primary structure of eel (Anguilla japonica) growth hormone.

Two molecular forms of growth hormone, GHs I and II, were isolated from a culture medium of the eel pituitary (Anguilla japonica). The complete amino acid sequence of GH I was determined in the present study. The hormone was reduced, carboxymethylated, and subsequently cleaved with cyanogen bromide and enzymes. Intact eel GH I was also digested with enzyme. The resulting fragments were separated by reverse-phase high-performance liquid chromatography (HPLC) and subjected to sequence analysis by automated gas-liquid sequencer employing an Edman method. Eel GH I consists of 190 amino acid residues with two disulfide linkages formed between residues 52-163 and 180-188. Sequence comparison with other vertebrate GHs revealed that eel GH I is closer to avian and mammalian GHs with 55% identity than to salmon GH with 48% identity.

Amino Acid Sequence↗

Cloning and analysis of transcription of the mei2 gene responsible for initiation of meiosis in the fission yeast Schizosaccharomyces pombe.

We have isolated a hybrid plasmid, pDB(mei2)2, containing a 7.4-kilobases (kb) DNA fragment from a Schizosaccharomyces pombe genomic library which is able to complement the mei2 mutation of S. pombe. Integration of the cloned DNA sequence at the mei2 site on chromosome I demonstrated that it contained the mei2 gene. This gene was localized on a 4.7-kb HindIII-PvuII fragment in the subclone pFMV402. Transcriptional regulation was studied by Northern blot analysis in which polyadenylated RNA was prepared from a heterozygous (h+N/h-S) diploid strain cultured either in nitrogen-rich growth medium or in nitrogen-free sporulation medium. The size of the major mei2 mRNA, which always gave a broad band, was estimated to be 4.2 +/- 0.2 kb, and a few minor bands (e.g., 3.2 and 1.8 kb) appeared as well. These transcripts appeared more abundantly in sporulating cells than in growing cells. Neither the mating type genes (mat) nor the mei3 gene was essential for transcription of the mei2 gene, since ample mei2 mRNA was detected in sporulation-deficient cells transferred to sporulation medium, such as h+N/h+N and h-S/h-S homozygotes, as well as mei1 and mei3 mutants.

Cloning, Molecular↗