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Biomedical subjects

M Mizuno

Publications and source records attributed to M Mizuno.

At least 577 records · Page 32Linked to original sources
PubMed1985

Effects of dolichol and dolichyl phosphate on in vitro differentiation of hematopoietic progenitors.

The exogenous addition of dolichyl phosphate (Dol-P), an active form of dolichol (Dol) that carries oligosaccharide chains for protein-N-glycosylation, significantly enhanced colony formation of mouse bone marrow hematopoietic progenitors (CFU-e, BFU-e, and CFU-gm) was stimulated by erythropoietin (Epo) and colony-stimulating factor (CSF), but Dol enhanced colony formation of CFU-e only. The effects of Dol or Dol-P on these hematopoietic progenitors were fully dependent on stimulation by Epo or CSF. Other mevalonate-metabolites, such as cholesterol, coenzyme Q10, and isopentenyladenine, had no effect on hematopoietic progenitors. These studies suggest that exogenous Dol-P enhances the frequency of differentiation of hematopoietic progenitors stimulated by Epo or CSF, and there may be a diversity in cellular response of these progenitors to Dol.

Adenine↗
PubMed1985

Impaired development of rat cerebellum induced by neonatal injection of the glycoprotein synthesis inhibitor, tunicamycin.

The effects of the protein glycosylation inhibitor tunicamycin on the postnatal development of the rat cerebellum were examined in vivo. Tunicamycin (0.2 micrograms) was injected intracranially into 1-day-old rats. Inhibition of glycosylation of the macromolecules in the cerebellum by tunicamycin treatment was suggested by a reduced incorporation of [3H]glucosamine into the trichloroacetic acid (TCA)-insoluble fraction. The tunicamycin treatment did not affect gain in body weight significantly. However the cerebellar weight was significantly reduced by 30-40% compared with that of the controls. Development of GABAergic and cholinergic innervations in the hypoplastic cerebellum was examined by measuring the activities of glutamate decarboxylase (GAD) and choline acetyltransferase (ChAT). The specific activity and the total activity of GAD were significantly reduced in the tunicamycin-treated cerebellum. In contrast the specific activity of ChAT was significantly increased, whereas the total activity of ChAT per cerebellum was identical with that of the controls. These results suggest that the intracranial injection of tunicamycin affects the postnatal development of rat cerebellum, such as GABAergic and cholinergic innervations.

Animals↗
PubMed1985

Fibre types, capillary supply and enzyme activities in human intercostal muscles.

The relative occurrence of slow twitch (ST) and fast twitch (FTa and FTb) fibres, fibre size, capillary supply, and glycolytic and oxidative enzyme activities in external (EXT) and internal (INT) intercostal muscles was determined on biopsies obtained during thoracotomy from the mid-axillary line in six patients with normal lung function. EXT and INT showed a similar occurrence of ST fibres. Both FTa and FTb fibres were seen in EXT while only FTa fibres were seen in INT. The size of the three fibre types in EXT was similar. In INT the fibre size was larger for FTa than for ST (P less than 0.05). INT appeared to have a larger number of capillaries per fibre than EXT (P less than 0.05). A positive correlation was demonstrated between variables measured during spirometry and fibre size in INT only. No difference in glycolytic and oxidative enzyme activities between EXT and INT was observed. The histochemical characteristics suggest that, in the mid-axillary line, INT are more used than EXT, though this conclusion did not appear to be confirmed by the enzyme activities determined.

3-Hydroxyacyl CoA Dehydrogenases↗
PubMed1985

Partial neuromuscular blockade and cardiovascular responses to static exercise in man.

In human subjects sustained static contractions of the quadriceps femoris in one leg were performed with the same absolute and the same relative intensity before and after partial neuromuscular blockade with either decamethonium or tubocurarine which reduced strength to about 50% of the control value. During the contractions performed with the same absolute force, the magnitude of the cardiovascular responses (heart rate and blood pressure) was greater during neuromuscular blockade than during control contractions. During the contractions involving the same relative force the magnitude of the cardiovascular responses was almost the same with and without neuromuscular blockade. These findings were independent of the drug used. The metabolic part of the exercise pressor reflex was assessed by the application of an arterial cuff 1/2 min before cessation of exercise and for the following 3 min of rest. Although heart rate and blood pressure decreased after cessation of exercise, application of the tourniquet resulted in higher post-exercise values and this effect was seen both with and without neuromuscular blockade. Muscle biopsies from the subjects' m. vastus lateralis were analysed for fast- and slow-twitch fibre composition showing 27-66% slow-twitch fibres. No correlation was found between cardiovascular responses to static exercise, with or without neuromuscular blockade, and fibre type predominance. The results suggest that the involvement of fast- or slow-twitch muscle fibres does not play a dominant role in the cardiovascular responses to static exercise in man. Both central command and reflex neural mechanisms are of importance, and it appears that these two control mechanisms are redundant and that neural occlusion may be operative. However, when partial neuromuscular blockade induces a disproportion between an increase in central command and a constant or decreasing muscle tension and metabolism, the larger signal arising from central command determines the magnitude of the cardiovascular responses.

Adult↗
PubMed1985

Studies on prolactin in human milk.

A possible physiological role of prolactin (PRL) in human milk was studied. The concentrations of milk PRL were 36.5 +/- 5.8 ng/ml on the first day after delivery and increased rapidly on the second day. Higher levels continued up to the fifth day. The levels of milk PRL showed no significant correlation with milk yield. Milk PRL was capable of binding to its receptors, suggesting its biological activities. In conclusion, human milk contains significant amounts of immunoreactive PRL. Milk PRL appears to be biologically potent, which raises the possibility that it may have certain physiological significance for the newborn.

Animals↗
PubMed1985

Effects of pregnancy and labor on oxytocin levels in human plasma and cerebrospinal fluid.

In order to investigate the significance of oxytocin in pregnancy and labor, oxytocin concentrations in plasma and cerebrospinal fluid (CSF) were determined using the specific radioimmunoassay. Plasma and CSF samples were obtained from 23 pregnant women (11 pre labor, 12 in labor), 15 nonpregnant women and 4 men at spinal puncture for anesthesia. In males and nongravidas, CSF levels of oxytocin were significantly higher than plasma levels. Plasma levels in pregnant patients pre or in labor were significantly higher than those in nongravidas. No significant difference between CSF levels in prelabor gravidas (mean +/- SE, 9.7 +/- 1.5 mu u/ml) and nongravidas (10.1 +/- 1.2 mu u/ml) was found. However, CSF levels in gravidas in labor (18.6 +/- 2.3 micromicrons/ml were significantly higher than the levels in prelabor gravidas. These results strongly suggest that oxytocin levels in human plasma and CSF are controlled by different mechanisms and that the increased oxytocin could have some specific central actions.

Adolescent↗
PubMed1985

Human papillomavirus DNA in female condylomata.

We have studied the presence and state of human papillomavirus (HPV) genomes in condylomata acuminata of the vulva, vagina, and cervix and in flat condylomas of the cervix from Japanese females by DNA hybridization with HPV 6 and 11 DNAs. Unintegrated HPV 6-related DNA (HPV 6 or 11 DNA) was detected in 55 out of 60 condylomata acuminata and in 1 out of 4 flat condylomas under stringent hybridization conditions. The HPV DNAs were identified as HPV 6 DNA in 29 condylomata acuminata (20 vulvar, 3 vaginal, and 6 cervical samples) and 1 flat condyloma and as HPV 11 DNA in 6 condylomata acuminata (6 vulvar samples). The data indicate close association of HPV types 6 and 11 with condylomata.

Adolescent↗
PubMed1985

Occurrence of human papillomavirus types 16 and 18 DNA in cervical carcinomas from Japan: age of patients and histological type of carcinomas.

We have detected by DNA hybridization human papillomavirus (HPV) types 16 and 18 DNA sequences in 19 and 3, respectively, out of 56 cervical carcinomas from Japan. Eighteen out of 19 HPV 16-positive specimens were from squamous cell carcinomas, whereas the three HPV 18-positive specimens were from a squamous cell carcinoma (1/50), an adenosquamous carcinoma (1/3), and an adenocarcinoma (1/3). The occurrence of HPV 16 DNA decreased in patients over 60 years old (less than or equal to 60 years, 15/34 (44%); 60 years less than, 4/22 (18%)) (P less than 0.05).

Adenocarcinoma↗
PubMed1985

[Study on the histopathological abnormalities of the umbilical cord].

There have been very few reports of studies on histological abnormalities of the umbilical cord. In the present study, we have investigated various abnormalities of the cord with special emphasis on the cord vasculature and the vestigial remnants based on developmental abberations. The incidence of single umbilical artery was 1/509 (0.2%), by which no special relation was signified between the single artery and the occurrence of congenital malformations of the neonate. Supernumerary umbilical vessels were found in 5/509 (1.0%) of the cases examined. Three out of five revealed the umbilical cord with two arteries and two veins, while two of them showed the umbilical cord with the normal 3 vessels associated with an accessory fourth vessel. It is of a great interest to note that fetal distress with or without fetal acidosis was demonstrated in all cases with the accessory fourth vessel, whereas the presence of supernumrary umbilical vessels was least related to the occurrence of congenital malformations of the neonates. The incidence of vestigial remnants was 30/509 (5.9%). The vestigial remnants were classified into two groups according to their epithelial pattern, i.e. flat epithelium and cuboidal or columnar epithelium. The vestigial remnants with flat epithelium type, considered to originate in the allantoic duct, were found in 2/3 (66.7%) of all cases with vestigial remnants. The vestigial remnants with cuboidal or columnar epithelium, considered to originate in the omphalomesenteric duct, were found in 1/3 (33.3%) of all cases with vestigial remnants, one of which case was associated with congenital malformation of omphalocele of the neonate.

Arteriovenous Malformations↗