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Biomedical subjects

T Ohashi

Publications and source records attributed to T Ohashi.

At least 271 records · Page 15Linked to original sources
PubMed1990

Intraocular irrigating solutions and permeability of the blood-aqueous barrier.

The effects of intraocular irrigating solutions on the blood-aqueous barrier were studied using rabbits injected with fluorescein isothiocyanate-labeled rabbit albumin. Two days after the injection, the anterior chamber was perfused for 121 minutes with one of the following solutions: normal saline, a commercially available citrate-acetate bicarbonate solution, or a glucose glutathione bicarbonate solution; the amount of fluorescein isothiocyanate-labeled rabbit albumin collected in the outflowing perfusate standardized to its plasma concentration was adopted as a blood-aqueous barrier permeability index. Of the three solutions, normal saline showed the highest permeability index and glucose glutathione bicarbonate solution showed the lowest. The effects of oxidized glutathione on the blood-aqueous barrier were also studied, using solutions containing various concentrations of oxidized glutathione. The permeability index for the solution containing 0.3 mmol/L of oxidized glutathione was significantly smaller than that for the solution without oxidized glutathione, suggesting that oxidized glutathione has a beneficial effect on the integrity of the blood-aqueous barrier.

Acetates↗
PubMed1990

Neuronal activity related to vertical eye movement in the region of the interstitial nucleus of Cajal in alert cats.

(1) Discharge characteristics of neurons in the region of the interstitial nucleus of Cajal (INC) were studied in alert cats during spontaneous or visually induced eye movement and sinusoidal vertical (pitch) rotation. Activity of a majority of cells (n = 68) was closely related to vertical eye position with or without bursting activity during on-direction saccades. They were called vertical burst-tonic (n = 62) and tonic (n = 6) neurons. Mean discharge rates for individual cells when the eye was near the primary position ranged from 35 to 133 (mean 75) spikes/s with a coefficient of variation (CV) ranging from 0.04 to 0.29 (mean 0.15). Average rate position curves were linear for the great majority of these cells with a mean slope of 3.9 +/- 1.2 SD spikes/s/deg. (2) The burst index was defined as the difference in discharge rate between maximal rate during an on-direction saccade and the tonic rate after the saccade. The values of mean burst index for individual cells ranged from 8 to 352 (mean 135) spikes/s. Tonic neurons had a burst index lower than 60 spikes/s and were distributed in the lower end of the continuous histogram, suggesting that burst-tonic and tonic neurons may be a continuous group with varying degrees of burst components. During off-direction saccades, a pause was not always observed, although discharge rate consistently decreased and pauses were seen when saccades were made further in the off-direction toward recruitment thresholds. Significant positive correlation was observed between average discharge rate during off- as well as on-direction saccades and tonic discharge rate after saccades for individual cells, which was not due to cats making saccades mainly from the primary position. (3) During pitch rotation at 0.11 Hz (+/- 10 deg), burst-tonic and tonic neurons had mean phase lag and gain of 128 (+/- 13 SD) deg and 4.2 (+/- 1.7 SD) spikes/s/deg/s2 relative to head acceleration. During pitch rotation of a wide frequency range (0.044-0.495 Hz), the values of phase lag were mostly constant (120-140 deg), while simultaneously recorded vertical VOR showed the mean phase lag of 178 deg. Vertical eye position sensitivity and pitch gain (re head position) showed significant positive correlation.(ABSTRACT TRUNCATED AT 400 WORDS)

Action Potentials↗
PubMed1990

Histochemical identification of oestrogen target cells in the medullary bone of laying hens.

1. Oestrogen target cells in the medullary bone of laying hens were examined using a histochemical method with fluorescein isothiocyanate labelled oestradiol. 2. Specific fluorescence was found to occur strongly in osteoblasts and weakly in osteoclasts on the medullary bone surface. 3. This study suggests that osteoblasts on the medullary bone surface are oestrogen target cells.

Animals↗
PubMed1990

Sequence of two alleles responsible for Gaucher disease.

Enzymatically amplified RNA transcripts were used to analyze the full coding region of the glucocerebrosidase gene from Gaucher disease patients. Two previously undescribed mutations were identified. One mutation consists of a single-base substitution in three different codons: codon 444, Leu (CTG) to Pro (CCG); codon 456, Ala (GCT) to Pro (CCT); and codon 460, Val (GTG) to Val (GTC). This mutant is called "pseudo pattern" (psi) because it is identical in sequence to a small region of the pseudogene in exon 10 (Horowitz et al., 1989). The other new mutation is a single-base substitution (C to T) resulting in the substitution of Cys for Arg in codon 463. These mutations in the human gene were duplicated in wild-type cDNA and expressed in 3T3 cells. The human mutant proteins were isolated by immunoaffinity and shown to have altered enzymatic properties demonstrating the causality of these two allelic mutations for Gaucher disease.

Amino Acid Sequence↗
PubMed1990

Clinical value of magnetic resonance imaging for cervical myelopathy.

The magnetic resonance imaging (MRI) findings in 115 cases of cervical myelopathy, 121 cases of cervical radiculopathy, and 64 cases of neck pain with no neurologic deficit were prospectively studied to investigate the clinical value of MRI for cervical myelopathy. The MRI findings in the T1-weighted sagittal projection were classified into four groups according to the degree of the compressed deformities of the cervical cord. The degree of compression of the cervical cord on MRI findings showed a significant correlation with the severity of myelopathy, the anteroposterior diameter of the spinal column, and the degree of compression of the dural tube in the myelograms (P less than 0.01). Fifty-one patients of cervical myelopathy had undergone both preoperative and postoperative MRI. Of these, the spinal canal of 47 patients that was well decompressed was recognized according to plain computed tomography (CT). However, 24 (51%) of these 47 patients showed on MRI a deformity in the spinal cord amounting to cord atrophy. The correlation between the clinical function of the spinal cord and the recovery of the cord deformity on MRI at the operative levels was accurately investigated in 34 patients who had no cord deformities in the adjacent intervertebral levels. Twenty patients with cord atrophy had slightly poor clinical results, although no significant difference was found between these 20 and 14 patients with recovery in the cord deformities. From these results, it was evident that T1-weighted MRI is useful in the accurate diagnosis of compression myelopathy, in accurately deciding the level of the disease focus, and in the accurate assessment of the surgical results.

Cervical Vertebrae↗
PubMed1990

Inhibitory effect of HSR-6071, a new anti-allergic agent, on experimental asthma in rats and guinea-pigs.

The experimental asthma caused by IgE antibody in rats was inhibited by HSR-6071 (6-(1-pyrrolidinyl)-N-(1H-tetrazol-5-yl)-2-pyrazinecarboxamide) (0.01-0.1 mg kg-1 i.v.) in a dose-dependent manner. The inhibitory activity of HSR-6071 was more potent than those of disodium cromoglycate and ketotifen, and equipotent with amlexanox. The bronchoconstriction mediated by IgE or IgG antibody in guinea-pigs was also prevented by HSR-6071 (0.3, 1 and 3 mg kg-1 i.v.), amlexanox (3, 10 and 30 mg kg-1 i.v.) and ketotifen (0.1 mg kg-1 i.v.) but not by disodium cromoglycate (10 mg kg-1 i.v.). HSR-6071 was more potent than amlexanox, but less potent than ketotifen. HSR-6071 suppressed antigen-induced histamine and SRS-A release from minced lung tissues of guinea-pigs sensitized passively with rabbit anti-EA serum and was a more potent inhibitor of the release of SRS-A than of histamine. On the other hand, histamine- or acetylcholine-induced bronchoconstriction in guinea-pigs was scarcely affected by HSR-6071 at doses sufficient to inhibit the experimental asthma, but LTD4-induced bronchoconstriction was dramatically inhibited. These results indicate that the inhibitory action on experimental allergic asthma of HSR-6071 may be due to suppression of antigen-induced histamine and SRS-A release from lung tissues and to antagonism of SRS-A action. In addition, HSR-6071 inhibited cyclic AMP phosphodiesterase activity and produced relaxation of the guinea-pig isolated trachea. These pharmacological actions may contribute to the production of the anti-allergic action of HSR-6071.

3',5'-Cyclic-AMP Phosphodiesterases↗
PubMed1990

Lupus nephritis with adult T cell leukemia.

A 64-year-old Japanese male patient with lupus nephritis associated with adult T cell leukemia (ATL) is described. Percutaneous renal biopsy demonstrated findings consistent with membranous lupus nephritis. To our knowledge, this is the first case of lupus nephritis complicated by ATL, suggesting that human T cell leukemia virus type I may be correlated not only to outbreaks of ATL but also to lupus nephritis/systemic lupus erythematosus.

Humans↗
PubMed1990

Leuprorelin acetate depot: results of a multicentre Japanese trial. TAP-144-SR Study Group.

The clinical efficacy and safety of 3.75 or 7.5 mg leuprorelin acetate depot given subcutaneously once every 4 weeks was evaluated in a collaborative study of 81 patients with untreated prostatic cancer. Efficacy of treatment was assessed using criteria based on a meeting of the Prostatic Cancer Study Group funded by the Japanese Ministry of Health and Welfare and using National Prostatic Cancer Project criteria. Japanese criteria enabled evaluation of individual parameters, unlike the National Prostatic Cancer Project system which classified a patient as unevaluable if one evaluation parameter was unavailable. Leuprorelin acetate depot suppressed serum luteinizing hormone, follicle stimulating hormone and testosterone concentrations. Objective response rates of the prostate, bone metastases, serum prostatic acid phosphatase and soft tissue metastases, and subjective dysuria and pain responses were comparable to those found with conventional hormone therapy. Leuprorelin acetate depot was well tolerated, with no significant differences in response to the two doses.

Adult↗
PubMed1990

Studies on antiallergic agents. I. Synthesis and antiallergic activity of novel pyrazine derivatives.

Various pyrazine derivatives were synthesized and their antiallergic activity was examined. The inhibitory activity on allergic histamine release of the compounds bearing a 5-tetrazolyl group was more potent than that of the corresponding carboxyl derivatives. The introduction of -CONH- or -NHCO- between the pyrazine ring and the 5-tetrazolyl group as a spacer greatly enhanced the activity. N-(1H-Tetrazol-5-yl)-2-pyrazinecarboxamide (I-3) was estimated to exhibit nearly the same potency as disodium cromoglycate (DSCG). The structure-activity relationship among various derivatives modified by introducing some substituents onto the 3-, 5- or 6-position of the pyrazine ring of I-3 was investigated. The activity remained unchanged or was reduced when such substituents as methyl, chloro, methoxy, methylamino and dimethylamino were introduced at the 3- or 5-position. In contrast, 6-substitution with various alkylamino groups more or less increased the activity. Among them, the 6-dimethylamino (I-17c) and 6-(1-pyrrolidinyl) (I-34) derivative were proved to be most potent. The IC50 values (concentration which produces 50% inhibition of the allergic histamine release) of I-17c and I-34 were determined to be 4.7 x 10(-10) and 4.6 x 10(-10) M, respectively. These two compounds produced a potent inhibitory activity on passive cutaneous anaphylaxis (PCA) in rat, not only by the intravenous route (ED50 = 0.0096 mg/kg for both compounds) but also by the oral route (ED50 = 0.19 and 0.18 mg/kg, respectively). On the other hand, when the pyrazine ring of some representative compounds was replaced with a pyridine ring, the inhibitory activity on histamine release was significantly reduced.

Animals↗
PubMed1990

Potent inhibitory activity of HSR-6071, a new antiallergic agent, on passive cutaneous anaphylaxis (PCA).

Antiallergic effects of 6-(1-pyrrolidinyl)-N-(1H-tetrazol-5-yl)-2-pyrazinecarboxamide (HSR-6071), a newly synthesized agent, were investigated. The 48-hr homologous passive cutaneous anaphylaxis (PCA) in rats was inhibited in a dose-dependent manner by i.v. and p.o. administration of the agent (ED50 = 0.0096 mg/kg and 0.18 mg/kg, respectively). The IgE-mediated histamine release from rat peritoneal exudate cells was inhibited by HSR-6071, with an IC50 of 4.6 x 10(-10) M. Regarding the non-immunological histamine release, HSR-6071 inhibited compound 48/80-induced, but not A23187-induced and spontaneous histamine release. On the other hand, an increase in vascular permeability induced by histamine, serotonin and bradykinin was unaffected by HSR-6071 in doses sufficient to inhibit PCA. In addition, the contractile responses of isolated guinea pig ileum to histamine, acetylcholine and serotonin were also unaffected by the agent even in a high concentration of 10(-4) M. These results indicate that HSR-6071 possesses a potent antiallergic activity and that the inhibition of PCA by HSR-6071 may be due to the suppression of chemical mediators release from mast cells.

Aminopyridines↗
PubMed1990

[The study of BBN induced bladder cancer in mice. Influence of Freund complete adjuvant and associated immunological reactions in mice].

To evaluate the genetic difference in induction of bladder cancer by N-butyl-N-(4-hydroxybutyl) nitrosamine (BBN), BBN was given to two different strains of mice, i.e. A/J (BCG resistant) strains and C57BL/6 (BCG susceptible) strains. The influence of Freund complete adjuvant (FCA), which includes BCG, was similarly examined along with associated cellular immunity as evaluated by footpad reaction (FPR). The results were as follows: 1. The incidence of bladder cancer was significantly higher in C57BL/6 strains (90.0%) than A/J strains (54.5%). 2. FCA reduced the incidence of bladder cancer significantly in C57BL/6 strains. 3. FPR, which reflects the delayed type hypersensitivity, was activated significantly in FCA treated C57BL/6 strains. These data suggest that the strain differences in mice probably explains the inhibition of carcinogenesis by FCA and cellular immunity.

Animals↗
PubMed1990

[The removal efficiency of beta 2-microglobulin, alpha 1-microglobulin and alpha 1-acid glycoprotein by using dialyzers in the bloodstream and transference of endotoxin through membranes].

Retention of beta 2-microglobulin (beta 2-MG) has been indicated as one of the causes of hemodialysis-associated amyloidosis. Membranes with higher permeability (high-performance membrane) have recently been developed accordingly. Several dialyzers were tested by us in an attempt to study their removal efficiency of beta 2-MG and higher molecular substances of alpha 1-microglobulin (alpha 1-MG) and alpha 1-acid glycoprotein (alpha 1-AG), as well as transferring of endotoxin (ET) through membranes into bloodstream. The membranes subjected to our study were PMMA, CTA, PS, EVAL-C and CA. Removal efficiency of beta 2-MG through EVAL-C and CA was lower as compared with that through other membranes (P less than 0.05), while the EVAL-C showed relatively higher removal efficiency for alpha 1-MG and alpha 1-AG. Permeability for ET was not observed with all membranes studied herein.

Alpha-Globulins↗
PubMed1990

[A case of Fabry's disease detected by renal biopsy findings].

A 39 year-old man was found to have mild proteinuria by urinary examination since one year ago. He was for the first time diagnosed as having Fabry's disease by histopathological and electronmicroscopic findings of the renal biopsy specimens, which showed the presence of numerous vacuolated cells and electron dense bodies inside the cells. The level of WBC alpha-galactosidase was significantly lower than normal level. The pedigree of this patient showed a familial history of various types of renal disease. One of the patient's brothers also showed decreased level of WBC alpha-galactosidase, who has been treated by maintenance hemodialysis for 2 years. It is concluded that early diagnosis of this disease through renal biopsy and WBC alpha-galactosidase level is important to manage the future course of patients with Fabry's disease.

Adult↗
PubMed1990

[A case of achondroplasia showing diffuse spinal canal stenosis].

A rare case of achondroplasia showing diffuse spinal canal stenosis is presented. A 39-year-old woman was admitted to our hospital because of numbness of lower extremities and intermittent claudication. The patient's height was 121cm and she had the typical clinical features of an achondroplastic dwarf. Neurological examination revealed spastic paraparesis, and sensory impairment below the level of T11 in the left side and L1 in the right. A plain X-ray feature of the spine showed spinal canal stenosis. The interpedicular distances were short in all vertebrae, and especially more prominent in the caudal lumbar region. The sacrum laid horizontally and the sacral angle was narrower than normal case. Myelography and computed tomographic myelography demonstrated severe stenosis of the subarachnoid space at the level of T9-11. Laminectomy was performed from the inferior half of T9 to T11. The yellow ligaments were prominently hypertrophic and these were removed as far as possible. Postoperatively, the weakness of the lower extremities was improved immediately, but numbness remained. Five months after the operation, she suffered from urinary dysfunction, so further laminectomy from T12 to L5 was performed. Also in this operation, hypertrophic yellow ligament was pathognomonic. Following this operation the patient had a good recovery course and returned to work.

Achondroplasia↗
PubMed1990

[Disturbance of the autonomic nerve system in patients with chronic renal failure--represented by variation coefficient of R-R intervals in the ECG as a parameter].

Autonomic nerve dysfunction in patients with chronic renal failure has of late become an issue to be investigated. R-R intervals in resting electrocardiograms were measured to evaluate activities of the cardiac parasympathetic nerve system. A total of 140 patients with chronic renal failure were studied to be compared with 20 normal controls (cont.) and 39 with diabetes mellitus (DM). Of these patients 15 were subjected to conservative treatment (CRF), while 125 patients were undergoing hemodialysis due to chronic renal failure-100 of them derived from chronic glomerulonephritis (HD) and 25 from diabetes mellitus (DM.HD). The variation coefficient of the R-R interval (CVRR) was measured after the subject patients had rested for over 15 minutes before a dialysis session. The mean CVRR were 2.15 +/- 1.25% in CRF group, 2.36 +/- 1.37% in HD and 1.37 +/- 0.99% in DM.HD. These values were significantly lower than in control group (4.70 +/- 2.64%). On the other hand, the value in DM.HD group, as shown above, was significantly lower than in HD. In CRF group the CVRR values lowered as residual renal functions decreased. No significant correlations between CVRR S and the duration of hemodialysis treatment were noted among the groups. In HD group the CVRR S were significantly lower in patients with hypotensive tendency during hemodialysis than in those who enjoyed good control of blood pressure. These results suggest that the measurement of CVRR S can be of help in evaluating autonomic nerve dysfunction in patients with chronic renal failure.

Adult↗
PubMed1989

Feline hybridoma growth factor/interleukin-6 activity.

An assay system was developed to measure feline hybridoma growth factor (HGF)/interleukin-6 (IL-6) activity in biological samples containing many kinds of cytokines by using the proliferation of the newly established mouse-rat hybridoma clone, B3B1. The proliferative response of this B3B1 clone was IL-6-specific, and could not be promoted by other cytokines including IL-1, IL-2, IL-3, and granulocyte-colony-stimulating factor (G-CSF). The anti-human B-cell stimulatory factor 2 (BSF-2)/IL-6 antiserum did not neutralize feline HGF/IL-6 activity in conditioned media prepared from feline con A-stimulated splenocytes and unstimulated alveolar macrophages, indicating antigenic differences between species. Feline HGF/IL-6 was eluted into the fractions corresponding to a molecular weight of 30,000-40,000 in gel filtration, and into the fractions at a salt concentration of 0.2-0.3 M NaCl in anion exchange chromatography. The physicochemical properties of feline HGF/IL-6 were slightly different from those of murine and human IL-6.

Animals↗
PubMed1989

Occurrence of an anti-peplomycin IgE antibody cross-reacting with bleomycin in a patient with cervical uterine cancer.

An allergic reaction to peplomycin was observed in a patient with cervical uterine cancer who had previously been treated with peplomycin. A positive Prausnitz-Küstner test and its elimination after heat treatment of the serum showed the production of anti-peplomycin IgE antibody. Peplomycin was coupled to a paper disc and a sensitive radioallergosorbent test for peplomycin was developed to quantitate the antibody. Patient serum IgE and IgG were purified by DE52 column chromatography; the IgE fraction contained binding activity to peplomycin. A competition test revealed that the antibody bound to both peplomycin and bleomycin. DNA, RNA, and mononucleotides had no effect on antibody binding, but the antibody inhibited peplomycin's activity.

Aged↗