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Biomedical subjects

A Ito

Publications and source records attributed to A Ito.

At least 829 records · Page 46Linked to original sources
PubMed1985

pH-related differentiation in the epithelia of the gastric mucosa of postnatal rats.

The postnatal development of the gastric mucosa was observed in Long Evans rats. In both pyloric and fundic mucosae, the mitotic index peaked at 5 days of age and then gradually decreased to reach a constant level from 14 days of age onward (P less than 0.05), the germinal region shifted from the deeper area of the mucosae upward to the middle layer. The number of parietal cells increased gradually (P less than 0.05). Gastric pH on the mucosal surface decreased from 6 on the day of birth to about 4 at 7 days of age and to about 2 at 28 days of age. The inverse relationship between the number of parietal cells and pH value on gastric mucosa was found to be highly significant (P less than 0.01). Trehalase and sucrase activities were observed at 7 days of age and lactase and maltase activities from 0 to 14 days of age. In the pyloric mucosae, foveolae containing goblet cells which were positive for Alcian blue-PAS and HID were observed between 0 and 7 days of age. These cells disappeared by 14 days of age concurrently with the decrease in pH value and increase in the number of parietal cells.

Age Factors↗
PubMed1985

Intestinal metaplasia induced by X-irradiation in different strains of rats.

Attempts were made to examine strain differences in the susceptibility of rats to intestinal metaplasia induced by X-irradiation. The gastric regions of 4 inbred male rats (SHR, F344, WKY, and LEW strains) in 5-week-old and 2 random bred male rats (SD, and WIS strains) were irradiated with a total dose of 20 Gy X-ray given in two equal fractions separated by three days. Upon sacrifice at 6 months after the last irradiation, the number of intestinal metaplastic crypts with positive reaction to alkaline phosphatase (ALP) appeared highest in the SHR and lowest in the WIS rats. Morphologically, the number of crypts with intestinal metaplasia in whole glandular stomachs of SHR, WIS, F344, and SD rats were higher than those in WKY and LEW rats. In the pyloric gland, it was highest in WIS rats, while in the fundic gland it was highest in SHR rats. The results show that the appearance and location of intestinal metaplasia by X-irradiation are greatly influenced by the strain of the rat.

Alkaline Phosphatase↗
PubMed1985

Characterization of androgen-binding protein in the human ovarian capsule and its changes by polycystic ovarian disease.

In sucrose density gradient analysis, the cytosol of human ovarian capsules was found to contain two (3H)dihydrotestosterone (DHT)-binding macromolecules with sedimentation constants of 9S and 4.6S, respectively. In the tissue, however, more than 95% of the total (3H)DHT binding to the cytosol was found to be due to the 4.6S macromolecule. This molecule was further characterized and identified as a tissue-specific androgen-binding protein (ABP). The dissociation constant and number of binding sites of ABP were 2.60 nM and 231 fmol/mg protein, respectively. ABP was further characterized by affinity chromatography on concanavalin A-Sepharose and was found to separate into two parts: one showed no interaction with the resin and was eluted in the void volume (peak I) and the other bound to the resin and was eluted by alpha-methyl-D-glucoside (peak II). The apparent amount of cytoplasmic ABP in capsules with polycystic ovarian disease was significantly lower than normal. This decrease in ABP was mainly due to the characteristic disappearance of peak II.

Adult↗
PubMed1985

Association of anti-dynein-1 cross-reactive antigen with the mitotic spindle of mammalian cells.

Two anti-dynein-1 antibodies were affinity-purified from rabbit antiserum produced by immunization with dynein-1 from sea urchin sperms. One was prepared with dynein-1 as the ligand and the other with the A heavy chains of dynein-1 as the ligand. In Western blots of axonemal proteins, the former antibody reacted with the A heavy chains of dynein-1 as well as with several other smaller polypeptides, whereas the latter bound almost exclusively to the A heavy chains. PtK2 cells stained by indirect immunofluorescence with either of these antidyneins had identical fluorescence patterns. The interphase cell showed rather diffuse and weak fluorescence in its nucleus and perinuclear cytoplasm. Its primary cilium and its centrioles also fluoresced. During prophase and prometaphase, a more intense fluorescence was present in the asters and developing spindle. During metaphase and anaphase the half-spindles fluoresced intensely in a fibrous pattern that corresponded to that of the spindle fibers, showing less intense fluorescence in the anaphase interzone. In telophase and early interphase, the intercellular bridge on each side of the midbody also was stained. These results are evidence that dynein-1, specifically the A heavy chains and/or a related antigen, is densely packed in the mitotic spindle of PtK2 cells.

Adenosine Triphosphatases↗
PubMed1985

[Screening for the antagonizing agents against lethal toxicity of neocarzinostatin. I. Inhibitory effects of various drugs on the toxicity of neocarzinostatin in vitro and in vivo].

Neocarzinostatin (NCS) used for the chemotherapy of leukemia and cancers such as stomach, pancreas and bladder, has been pointed out to have the side effects mainly causing leukopenia. In order to prevent these side effects of NCS by systemic administration, we have attempted to inject NCS directly into the tumor tissues and to inactivate NCS leaked from the tissues by the treatment of antidotes for NCS. The present report deals with the influence of some antidotes on the toxicity of NCS in vitro and in vivo. The results demonstrated that; Four SH-compounds, such as thiopronin, glutathione (reduced form), sodium thioglycolate and L-cysteine monohydrochloride monohydrate were effective to inactivate antibacterial activity of NCS against M. luteus ATCC 9341 in vitro. It was recognized that acute toxicity of NCS was reduced by pretreatment of these SH-compounds and its action was dose related. The LD50 values of NCS intravenous administration in mice increased 5.8- to 24-fold when 150, 300, 500 and 1,000 mg/kg of thiopronin were administered intravenously 2 minutes prior to NCS. And 2.3- to 4.2-fold by 500 and 1,000 mg/kg of glutathione (reduced form), 1.6- to 4.2-fold by 50, 100 and 200 mg/kg of sodium thioglycolate, 1.9- to 4.2-fold by 100, 200 and 400 mg/kg of L-cysteine monohydrochloride monohydrate respectively. On the other hand, pretreatment of NCS didn't affect the acute toxicity of thiopronin.

Animals↗
PubMed1985

[Acute idiopathic myocarditis having myocardial inflammatory swelling demonstrated by echocardiography: a case report].

A case of acute idiopathic myopericarditis with transient severe swelling and akinesis of the interventricular septum on echocardiograms was reported. A 35-year-old man was admitted to our CCU because of cardiogenic shock five days after the onset of "common cold". Electrocardiograms revealed low voltage and ST-segment elevation in all leads except for a VR and a VL. Serum CPK, GOT and LDH were slightly elevated. Echocardiograms showed severe asymmetrical septal hypertrophy (ASH, 20 mm), akinesis of the interventricular septum and moderate pericardial effusion. With improvement of the clinical course and of the hemodynamic data, the thickness and wall motion of the interventricular septum became normal. Serum antiviral antibodies were not elevated throughout the course. Transvenous percutaneous right ventricular endomyocardial biopsy revealed degeneration and fragmentation of the myofibrils with interstitial cellular infiltration and edema in the subacute phase (8th hospital day), but showed only focal fibrosis in the chronic phase. Coronary arteriograms and left ventriculograms in the chronic phase (50th hospital day) were normal. From these findings we can conclude that the severe transient ASH is due to myocardial inflammatory swelling.

Adult↗
PubMed1985

Genetics of susceptibility of rats to trigeminal schwannomas induced by neonatal administration of N-ethyl-N-nitrosourea.

A genetic analysis was done on the induction of trigeminal schwannomas by N-ethyl-N-nitrosourea [(ENU) CAS: 759-73-9] in susceptible LE rats, resistant WF rats, and their F1, F2, and reciprocal backcross hybrids. Both sexes of all strains were given a neonatal sc injection of 40 mg ENU/kg body weight and were sacrificed at 6 months after treatment. Many neurogenic tumors were induced in the central nervous system of all strains of rats. However, the incidence of trigeminal schwannomas in LE rats was 93% in males and 86% in females, whereas in WF rats the incidence was 24% in males and 20% in females. F1 and F2 hybrids showed an intermediate susceptibility (62 and 82% in F1 males, 79 and 86% in F2 males, 26 and 38% in F1 females, and 65 and 77% in F2 females). The incidence in hybrids backcrossed to LE was high (90 and 100% in males and 77 and 83% in females), and the incidence in hybrids backcrossed to WF was low (35 and 38% in males and 11 and 7% in females). The findings suggest that susceptibility to the induction of trigeminal schwannomas by ENU does not result from the expression of genes that are simple dominant or recessive genes. A genetic model involving three independently segregating loci may explain the experimental results. In all strains of rats, particularly the F1 hybrids, males were more susceptible than females to the induction of trigeminal schwannomas by ENU.

Animals↗
PubMed1985

Inhibitory effect of phenobarbital on the development of gliomas in WF rats treated neonatally with N-ethyl-N-nitrosourea.

The present study was undertaken to evaluate the effect of phenobarbital (PB) on the development of neurogenic tumors induced in WF rats by neonatal administration of N-ethyl-N-nitrosourea (ENU; CAS: 759-73-9). Group I rats were given a single sc injection in the backs of 5 mg ENU/kg body weight within 24 hours after birth. In group II, continuous oral administration of 0.05% PB in the drinking water was commenced 4 weeks after birth. Following neonatal injection of ENU, administration of PB was commenced 4 weeks after birth in group III. Rats in group IV served as untreated controls. All groups consisted of about an equal number of both sexes of rats. The experiment was terminated when the rats were 52 weeks old. The incidence of all neurogenic tumors in both sexes combined was 11 of 26 (42%) in group I and 3 of 22 (14%) in group III (P greater than .05). The incidence of gliomas alone was 10 of 26 (38%) in group I and 2 of 22 (9%) in group III (P less than .05). When females and males were evaluated separately, the incidence of gliomas in females was 7 of 13 (54%) in group I and 1 of 12 (8.3%) in group III (P greater than .05), whereas in males, 3 of 13 (23%) in group I and 1 of 10 (10%) in group III (P greater than .05), the difference was not statistically significant. At the end of the experiment the mean serum level of PB in females (33.0 micrograms/ml) was significantly higher than that in males (19.8 micrograms/ml) (P less than .05). These data suggest an inhibitory effect of PB on the development of ENU-induced gliomas in female rats.

Animals↗
PubMed1985

Induction of gliomas in Mongolian gerbils (Meriones unguiculatus) following neonatal administration of N-ethyl-N-nitrosourea.

Mongolian gerbils (Meriones unguiculatus) were given an sc injection (40 mg/kg body wt) of N-ethyl-N-nitrosourea [(ENU) CAS: 759-73-9] on postnatal day 1 (group I) or day 29 (group II). Untreated gerbils served as controls (group III). Of 32 gerbils in group I, 10 (31%) developed a total of 14 gliomas after an observation period of 12 months, whereas no gliomas were observed in groups II and III. Seven gliomas were located in the spinal cord, 6 were in the cerebrum, and 1 was in the cerebellum. Histologically, all were oligodendrogliomas. In group II, 1 meningeal tumor (4%) was observed among 27 gerbils. ENU also induced cutaneous melanomas (22% in group I, 15% in group II, and 0% in group III), kidney hemangiomas (6% in group I, 26% in group II, and 0% in group III), and ameloblastomas of the lower jaw (6% in group I and 0% in groups II and III).

Animals↗