Search PubMed⌕ Search

Biomedical subjects

H Ohta

Publications and source records attributed to H Ohta.

At least 865 records · Page 48Linked to original sources
PubMed1975

Maturation and interrelationship of mouse mononuclear phagocytes in bone marrow, peripheral blood and peritoneal cavity in terms of erythrophagocytic activity.

Ingestion by mononuclear cells in bone marrow, peripheral blood and the peritoneal cavity of red cells treated with antibodies and various chemicals was studied in an attempt to characterize these cell lines during development and to clarify the interrelationship among them. Bone marrow mononuclear phagocytes became intensively phagocytic during the second day of culture, indicating that the maturation time from progenitor cells to macrophages was about 48 hr. Blood monocytes exhibited very active erythrophagocytic activity after 24 to 48 hr cell culture. Uptake of sensitized red cells by both the cell lines was markedly inhibited by IgG irrespective of time periods of cell culture. Majority of peritoneal lymphocyte-like cells (LLC) separated from other forms of mononuclear cells were shown to become capable of erythrophagocytosis with maturation time to macrophages between 24 to 48 hrs. Under non-stimulated steady state, uptake of sensitized red cells by peritoneal macrophages was far less sensitive to IgG inhibition than that by bone marrow mononuclear phagocytes and blood monocytes, suggesting that IgG receptor does not play main role for the erythrophagocytosis by peritoneal macrophages. Peritoneal cells collected under inflammatory stimulus exhibited a character similar to bone marrow mononuclear phagocytes and blood monocytes with regard to IgG receptor. It was suggested that under steady state peritoneal macrophages arise and mature from local proliferative pool with some different phagocytic mechanism from that of bone marrow mononuclear phagocytes.

Animals↗
PubMed1975

[Penetration of cephaloridine and cephalothin into the cerebrospinal fluid-clinical study (author's transl)].

There were 35 cases, treated with Cephaloridine or Cephalothin after neurosurgical operation. Neurological surgeon always troubled with passage of blood-brain barrier when drug was given. Antibiotics was not exceptionally, therefore we, neurological surgeon, must select the effective drug to bacterium, that which penetrated enough to the intracranial organ through the blood-brain barrier. In this paper, we measured the concentration of Cephaloridine and Cephalothin into cerebrospinal fluid in the cases with non inflammatory meninges. We collected the cerebrospinal fluid from continued ventricle tap and serum, then measured the concentration of the drug with bioassay. Cephaloridie treated cases. 22 cases. 1) 1 g intramuscular injection. 4 cases. Serum level got to highest value, 64 mug/ml (mean value) 1 hour after injection. CSF level got to maximum concentration 46.8 mug/ml. (mean value) serum mean level 21.5 mug/ml. CSF mean level 0.73 mug/ml. 2) 1 g 3 minutes-intravenous injection 5 cases. Serum level got to highest value 67.5 mug/ml. CSF maximum level was 5.25 mug/ml. Serum mean level 19.74 mug/ml. CSF mean level 0.61 mug/ml. 3) 1 g 1 hour-intravenous drip. 9 cases. Serum maximum level 121.0 mug/ml. CSF maximum level 2.30 mug/ml. Serum mean level 20.08 mug/ml. CSF mean level 0.67 mug/ml. 4) 1 g 8 hours-intravenous drip. 3 cases. Serum maximum level 61.0 mug/ml. CSF maximum level 1.36 mug/ml. Serum mean level 14.78 mug/ml. CSF mean level 0.47 mug/ml. Cephalothin treated cases, 12 cases. 1) 1 g 8 hours-intravenous drip, 4 cases. In fact we could detect the drug only in one case, in CSF, and we could not in other three cases. In KF - 4 case, serum maximum concentration was 26.0 mug/ml, CSF maximum concentration was 0.07 mug/ml. Serum mean level 16.97 mug/ml. CSF mean level 0.01 mug/ml 2) 2 g 1 hour-intravenous drip, 9 cases. Serum maximum level 690.0 mug/ml. CSF maximum level 2.03 mug/ml. Serum mean level 29.59 mug/ml. CSF mean level 0.06 mug/ml. In cephaloridine cases, the tendency was observed, that which, as concentration of the drug in CSF increased, cell count and protein decreased, and, as concentration of the drug decreased, cell count and protein increased. CSF/serum concentration ratio of Cephaloridine increased, when time passed, in intramuscular, 3 minutes intravenous, and 1 hour-intravenous drip group. Then only in 8-hours-intravenous prip group. Then only in 8-hours-intravenous drip group, concentration ratio decreased. In Cephaloridine group, mean value of CSF/serum ratio showed. 1 g i.m. 0.084 1 g 3 minutes-i.v. 0.098 1 g 1 hour-i.v. 0.194 1 g 8 hours-i.v. 0.044.

Adolescent↗
PubMedDate not supplied

Protective effect of taurine against isoprenaline-induced myocardial damage.

The effect of the sulfur amino acid, taurine, was examined on histological and biochemical changes induced by a toxic dose of isoprenaline in chick hearts. Isoprenaline treatment (80 or 240 mg/kg id twice daily for 4 days) caused a dose-dependent increase in heart weight and decrease in myocardial ATP. Isoprenaline administration (240 mg/kg id twice daily) produced necrotic changes in hearts, such as eosinophilic degeneration, myolysis, interstitial oedema, fibrosis, and inflammatory cell infiltration. Substantial accumulation of calcium was also observed. Taurine content of the heart was not significantly decreased. Parenteral administration of taurine (200 mg/day for 7 days) partially protected against these necrotic changes induced by isoprenaline. It is suggested that the protective effect of taurine against isoprenaline-induced myocardial injury might be due in part to the prevention of the massive overloading with calcium which is thought to cause myocardial cell necrosis.

Adenosine Triphosphate↗
PubMedDate not supplied

Beneficial effect of coenzyme Q on myocardial slow action potentials in hearts subjected to decreased perfusion pressure-hypoxia-substrate-free perfusion.

Coenzyme Q, an important component of the electron transfer system in mitochondria, plays a central role in energy production aerobically. The effect of pretreatment with coenzyme Q10 (Co Q) on myocardial slow action potentials (APs) and accompanying contractions and on myocardial high energy phosphate content was studied in perfused hearts subjected to decreased perfusion pressure-hypoxia-substrate-free. Post-hatched chicks were treated i.p. with 10 mg/kg of Co Q daily for 5 days. To study the slow APs exclusively, the fast Na+ channels were voltage-inactivated by elevated K+ (25 mM) Tyrode solution. The Ca++-dependent slow APs were induced by elevating [Ca]o to 5.4 mM; hearts were paced at a rate of 40 per min. Hearts which had been pretreated with Co Q were protected against the deleterious effect of decreased perfusion pressure - hypoxia - substrate-free perfusion on mechanical performance accompanying the slow Ca++-Na+ APs. The slow APs in hearts pretreated with Co Q were also less affected than were non-treated hearts. However, the myocardial ATP and total adenine nucleotides were not affected by exogenous Co Q. It was suggested that exogenous Co Q could protect against the decline of cardiac contractions via improved availability of slow APs during decreased perfusion pressure - hypoxia - substrate-free, independently of the cellular high energy phosphate level.

Animals↗
PubMedDate not supplied

Role of vasoactive intestinal polypeptide (VIP) in regulating the pituitary function in man.

Intramuscular injection of synthetic VIP (200 micrograms) resulted in a rapid increase in plasma prolactin (PRL) concentrations in normal women, which was accompanied by the 4- to 7-fold increase in plasma VIP levels. Mean (+/- SE) peak values of plasma PRL obtained 15 min after the injection of VIP were higher than those of saline control (28.1 +/- 6.7 ng/ml vs. 11.4 +/- 1.6 ng/ml, p less than 0.05). Plasma growth hormone (GH) and cortisol levels were not affected by VIP in normal subjects. VIP injection raised plasma PRL levels (greater than 120% of the basal value) in all of 5 patients with prolactinoma. In 3 of 8 acromegalic patients, plasma GH was increased (greater than 150% of the basal value) by VIP injection. In the in vitro experiments, VIP (10(-8), 10(-7) and 10(-6) M) stimulated PRL release in a dose-related manner from the superfused pituitary adenoma cells obtained from two patients with prolactinoma. VIP-induced GH release from the superfused pituitary adenoma cells was also shown in 5 out of 6 acromegalic patients. VIP concentrations in the CSF were increased in most patients with hyperprolactinemia and a few cases with acromegaly. These findings indicate that VIP may play a role in regulating PRL secretion in man and may affect GH secretion from pituitary adenoma in acromegaly.

Adenoma↗
PubMedDate not supplied

Prostaglandin D2 stimulates vasoactive intestinal polypeptide release into rat hypophysial portal blood.

The effect of prostaglandin D2 (PGD2) on vasoactive intestinal polypeptide (VIP) release from the hypothalamus was examined by determining plasma VIP levels in rat hypophysial portal blood. Intraventricular injection of PGD2 (5 micrograms/rat) caused a 3-fold increase in the concentration of plasma VIP in hypophysial portal blood in anesthetized rats. A PGD2 metabolite, 13,14-dihydro-15-keto PGD2, did not affect VIP levels in portal blood. The flow rate of hypophysial portal blood was not changed after the injection of PGD2. The intraventricular injection of PGD2, but not PGD2 metabolite, resulted in an increase in peripheral plasma prolactin (PRL) levels in the rat. These findings suggest that PGD2 plays a stimulatory role in regulating VIP release from the hypothalamus into hypophysial portal blood and causes PRL secretion from the pituitary in rats.

Animals↗
PubMedDate not supplied

Further evidence that peptide histidine isoleucine (PHI) may function as a prolactin releasing factor in rats.

Intraventricular administration of peptide histidine isoleucine (PHI) (200 ng, 1, 5 and 10 micrograms/rat) resulted in a significant and dose-related increase in plasma prolactin (PRL) levels in urethane-anesthetized rats and in conscious rats with intraatrial and intraventricular catheters. Intravenous injection of PHI (10 micrograms/rat) also raised plasma PRL levels in these animals. In in vitro studies, PRL release from superfused rat anterior pituitary cells was stimulated by PHI (10(-9), 10(-8) and 10(-7) M) in a dose-related manner. The stimulating effect of PHI (10(-7)M) on PRL release in vitro was as potent as that of vasoactive intestinal polypeptide (VIP) (10(-7) M) and was observed even in the presence of dopamine (10(-7) M). These results suggest that PHI plays a stimulating role in regulating PRL secretion by acting, at least in part, directly on the pituitary in the rat.

Animals↗
PubMedDate not supplied

The effect of macrophage colony-stimulating factor (M-CSF) on the progression of lipid-induced nephrotoxicity in diabetic nephropathy.

In order to elucidate the role of macrophage in lipid-induced nephrotoxicity in diabetic nephropathy, we examined the effect of macrophage colony-stimulating factor (M-CSF) on the progression of renal lesions in hypercholesterolemic steptozotocin (STZ)-diabetic rats fed with high cholesterol chow. Hypercholesterolemia aggravated albuminuria in diabetic rats accompanied by infiltration of macrophages in glomeruli. Treatment with M-CSF suppressed simultaneously infiltration of glomerular macrophages and urinary albumin excretion in hypercholesterolemic diabetic rats. These results suggest that infiltration of glomerular macrophage has a primary role in lipid-induced nephrotoxicity in diabetic nephropathy, and M-CSF is involved in this process as a preventive factor.

Albuminuria↗
PubMedDate not supplied

Differences in axial bone mineral density, serum levels of sex steroids, and bone metabolism between postmenopausal and age- and body size-matched premenopausal subjects.

The present study was designed to investigate the differences in serum levels of sex steroids, bone metabolism, and bone mineral density (BMD) between 22 premenopausal subjects and 21 age- and body size-matched postmenopausal subjects. Dual photon absorptiometry (DPA) demonstrated total body BMD significantly decreased in postmenopausal subjects. It was also found that not only spinal BMD as assessed by DPA, but also total third lumbar BMD and third lumbar trabecular BMD as measured by quantitative computed tomography (QCT) significantly decreased in these subjects. In postmenopausal subjects, the urinary-hydroxyproline/creatinine ratio increased significantly, which suggested that bone resorption had been stimulated, and serum levels of alkaline phosphatase (ALPase) and osteocalcin also significantly increased, which suggested a stimulation of bone formation. Consequently, the reduction in BMD was thought to result from a negative balance of bone resorption versus bone formation, or a high turnover of bone metabolism. Androgens were not confirmed to participate in these changes in bone metabolism, but the reduction in serum levels of estradiol, as a major factor, and the reduction in serum levels of estrone, as a participating factor, were assumed to result in an increase in bone resorption in excess of bone formation.

Absorptiometry, Photon↗
PubMedDate not supplied

The near-infrared electronic endoscope for diagnosis of esophageal varices.

We developed an electronic endoscope sensitive to light delivered by an infrared laser, which makes it possible to visualize submucosal vessels of the gastrointestinal tract. The system consists of a modified electronic endoscope and an image processing unit. A high output laser diode was chosen as the source of the infrared ray with a wavelength of 815 nm, an output of 200 milliwatts, and a band width of 30 nm. Using this instrument, esophageal varices were classified into three categories: venous dilation, dark spot, and diffuse dark area. The venous dilation and dark spot appearances correlated with early esophageal varices, which were rarely seen with visible light. On the other hand, the diffuse dark area appearance was considered to be a high risk sign of future bleeding. This system is useful not only for the early diagnosis of esophageal varices, but also for the localization of optimal puncture sites and the evaluation of the effect of sclerotherapy.

Adult↗