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Biomedical subjects

Y Hara

Publications and source records attributed to Y Hara.

At least 487 records · Page 27Linked to original sources
PubMed1992

5838-DNI, a deoxyribonuclease inhibitor produced by Streptomyces sp. strain no. A-5838.

5838-DNI, an inhibitor of deoxyribonuclease (DNase) II from porcine spleen was produced by Streptomyces sp. strain No. A-5838. The structure of 5838-DNI was shown to be 1,4,4a,5,12,12a-hexahydro-4,4a,11,12a-tetrahydroxy-3,8-dimethoxy-9- methoxycarbonyl-10-methyl-1,5,12-trioxo naphthacene. Although similar in structure to tetracenomycin C, which is an antibiotic against Gram-positive bacteria, 5838-DNI has different antibacterial activity. 5838-DNI was distinguished from 5923-DNI, a previously reported DNase II inhibitor, in inhibitory activity against each enzyme. 5838-DNI showed dependency of inhibition on pH and temperature, and inhibited phosphodiesterase I in a competitive manner. These data suggest that 5838-DNI is the first reported example of an inhibitor of microbial origin which is able to inhibit DNase II and phosphodiesterase I.

Animals↗
PubMed1992

[Study of factors requiring more than two ESWL treatments].

Nine hundred and fifty cases with renal and ureteral stones were treated by extracorporeal shock wave lithotripsy (ESWL) with Siements Lithostar unit from September, 1988 to October, 1990 at Kinki University Hospital. ESWL treatments were performed twice or more on 110 cases (DIFFICULTY GROUP). Ninety-seven cases who were cured by only one ESWL treatment were selected randomly as the control group. The two groups were retrospectively compared to study the factors requiring more than two times of ESWL treatments. There was a significant difference in the time of spontaneous stone discharge before ESWL treatment, the degree of hydronephrosis and the incidence of staghorn calculi as well as middle-lower ureteral calculi between the two groups. There was not a significant difference but a tendency to a longer period of stone existing at the same position and a higher percentage of past history of percutaneous nephrolithotropsy (PNL) in DIFFICULTY GROUP. Because ESWL monotherapy is considered to have limitations, auxiliary procedures or other treatments such as PNL and transurethral lithotripsy are recommended for patients in who in the stones were poorly disintegrated by the first ESWL treatment.

Humans↗
PubMed1992

[Analysis of anchorage independent growth of human prostate cancer cell line LNCap].

LNCap, a human prostate cancer cell line, possess androgen dependent growth characteristics. We studied anchorage independent proliferation of LNCap cells using semi-solid agarose double layer culture. The cells formed colonies in the semi-solid medium supplemented with charcoal filtered steroid free fetal calf serum and maximal colony formation was obtained in the medium with 10% serum. The addition of several steroids (testosterone, dihydrotestosterone, ethinylestradiol) influenced the colony formation. Testosterone at the concentration of 10(-8) M to 10(-10) M stimulated colony formation with optiman of 10(-9) M. When LNCap cells were placed under the basal layer of the semi-solid culture as feeder cells, also stimulated was the colony formation of the LNCap cells cultured in upper layer of semi-solid medium. The addition of EGF, TGF alpha and TGF beta to the medium also stimulated the colony formation. The combined effect of EGF and TGF alpha was shown to be cooperative with testosterone. TGF beta, however, did not show such cooperative effect with testosterone on colony formation. The addition of the anti-body to EGF, TGF alpha or TGF beta to the medium decreased the colony formation of LNCap cells. These results suggest that LNCap cells excrete EGF, TGF alpha, TGF beta and/or similar substances and these factors autocrinely decorate the cell proliferation of LNCap human prostate cancer cells.

Cell Division↗
PubMed1992

A randomized multicenter trial to evaluate the effects of UV-Flash system on peritonitis rates in CAPD.

A number of systems and devices have been developed to reduce peritonitis in CAPD patients. One of the newer developed systems in the UV-Flash. A retrospective study was conducted in five Japanese hospitals to measure the efficiency of the UV-Flash system in reducing the peritonitis rate for CAPD patients. This study took place between January 1983 to January 1992. The UV-Flash system had a significantly lower peritonitis rate (1/46.6 patient months) compared to the Standard system (1/27.5), but showed nominal significance when compared to the Disconnect system (1/47.6). Due to the lack of differentiation in peritonitis rates between the UV-Flash and Disconnect system, patient types for both systems were analyzed. The study found more impaired patients on UV-Flash (37.2%) as opposed to the Disconnect (9.8%). These impaired patients treated on the UV-Flash system showed a significantly lower peritonitis rate (1/27.5) when compared to the Disconnect (1/9.7) system. The UV-Flash system proved able to achieve sufficient prevention of peritonitis in CAPD patients. Thus, this system can be successfully applied to high risk CAPD patients.

Female↗
PubMed1992

[Anterior sacral meningocele associated with tethered cord syndrome].

A case of anterior sacral meningocele associated with tethered cord syndrome is reported. A 5-year-old boy was admitted for urinary and fecal incontinence which had persisted since his birth. Abdominal MRI and sacral CT showed a presacral cystic mass communicating with the spinal dural sac through a neck traversing a sacral bony defect and tethered spinal conus. Neurological examination showed that the patient had a neurogenic bladder, atrophy of the legs and anesthesia below the S3 level. Operative finding revealed a thickened filum terminale attached to the wall of the presacral meningocele. Agenesis of the nerve root below the S2 level was identified, and no neural elements entered into the sac. Untethering was performed. Postoperative course was uneventful and the patient is doing well with his neurogenic bladder gradually improving.

Child, Preschool↗
PubMed1992

[Age-dependent alterations in clinical features of pulmonary tuberculosis].

Age-related changes in clinical features of 182 patients diagnosed as having pulmonary tuberculosis from positive culture results of tubercle bacilli were extensively investigated. The percentage of cases detected using mass miniature radiophotography (MMR) was highest in the patients aged 30-39 years, and then decreased with increasing age. It was only 16-19% in those aged 60 years or older. Certain conditions, such as cardiovascular diseases, hypertension, diabetes mellitus, malignancy and other lung diseases, were common in the patients aged 60 years or older. Systemic symptoms, including weight loss and anorexia, and physical abnormalities, including fever and crackles, were common in these patients. Anemia tended to be predominant in the patients aged 60 years or older. The middle/lower lobes were involved more frequently in these patients, in whom the disease distribution was more than one lobe, or disseminated. Positive smear results and negative anergy were more frequently noted in the patients aged 60 years or older. The mortality from tuberculosis in these patients was 4% (7 cases). Although gastrointestinal disorder due to antitubercular drugs was more common in the patients aged 80 years or older, eosinophilia was less frequently observed. Today, improved conditions, better sanitation and the development of new chemotherapeutic agents have contributed to the decline of tuberculosis among the general population. But more efficient procedures that allow the early detection or diagnosis of pulmonary tuberculosis in the elderly should be achieved as soon as possible.

Adult↗
PubMed1991

Gastric hyperacidity and mucosal damage caused by hypothermia correlate with increase in GABA concentrations of the rat brain.

The involvement of brain GABA mechanisms in acid secretion and maintenance of gastric mucosal integrity was studied in the anesthetized rat. Cold exposure lowered the rectal temperature and stimulated acid output in the anesthetized rat. The acid response to cold exposure was completely suppressed by surgical vagotomy. The substantial increase in brain GABA content evoked by pretreatment with aminooxyacetic acid (10 and 20 mg/kg s.c. x 3) significantly potentiated the gastric acid response to the cold exposure stress; suppression of the GABA content induced by semicarbazide (100 mg/kg s.c.) reduced the acid response to cold. Significant correlations were found between the brain GABA contents and the acid secretory activity and also between the GABA contents and the ulcer index of gastric lesions induced by the cold stress. These results indicate that hypothermia evoked by cold exposure stimulates gastric acid secretion and induces gastric lesions through central GABA mechanisms in the rat.

Aminooxyacetic Acid↗
PubMed1991

[Studies on thyroid hormone autoantibody (THAA) in 2 cases of Graves' disease with spuriously high free thyroxine values].

Two patients with Graves' disease treated with methimazole (MMI) showed a discrepancy between serum free T4 (FT4) values and other hormone values (especially total T4) which was due to the presence of potent binding activity to labelled T4 analogue (125I-aT4) in their serum. This activity was demonstrated to be in immunoglobulin G (IgG) with kappa light chain isotype in both patients. The binding of 125I-aT4 to their serum was inhibited by unlabelled T4 in a dose-dependent manner. Autoantibodies had almost identical binding affinity to T4 and aT4, although they precipitated more radioactivity when 125I-aT4 was used. The binding of IgG purified from patients' sera to labelled T4 or aT4 was not greater than the corresponding sera, suggesting that the thyroxine binding proteins did not interfere with the assay. Since the specific radioactivity of 125I-aT4 is almost 10 times higher than that of 125I-T4, autoantibodies can precipitate almost 10 times more radioactivity in the FT4 assay than the total T4 assay, thus leading to the spuriously high FT4 values and large discrepancy between FT4 and TT4 values.

Adult↗
PubMed1991

Neoplastic epithelial cells express alpha-subunit of muscle nicotinic acetylcholine receptor in thymomas from patients with myasthenia gravis.

We studied the expression of mRNAs coding for the alpha-subunit of the muscle nicotinic acetylcholine receptor (AChR) in thymomas from patients with myasthenia gravis (MG). Northern blot analysis failed to detect the expression, but amplification of mRNAs derived from thymomas by reverse transcription and polymerase chain reaction produced the DNA fragments containing the nucleotide sequence coding for part of the alpha-subunit. We further revealed that the alpha-subunit mRNA was derived from neoplastic epithelial cells of thymoma. Our results support the hypothesis that AChR expressed in thymoma is a candidate for the primary antigen which induces autoimmune responses to muscle AChR. The close relationship between MG and thymoma may be at least in part explained by this hypothesis.

Amino Acid Sequence↗
PubMed1991

Acidic fibroblast growth factor-like immunoreactivity in brain of Alzheimer patients.

Localization of acidic fibroblast growth factor (aFGF)-like immunoreactivity was examined in postmortem human brain tissue of Alzheimer and age-matched control cases using a rabbit polyclonal antibody specific for aFGF. In control cases, a small number of glial cells were stained very weakly in white but not in gray matter. In Alzheimer cases, some astrocytes were strongly stained for aFGF in both gray and white matter. These intensely staining cells were frequently observed surrounding senile plaques, but represented a small proportion of the total astrocytic population. The present study suggests that aFGF may be upregulated in areas of Alzheimer pathology.

Aged↗
PubMed1991

Effects of pirarubicin, an antitumor antibiotic, on the cardiovascular system.

In the present study we examined the effects of pirarubicin [(2"R)-4'-O-tetrahydropyranyladriamycin, THP] on a cardiovascular system. An injection of THP (0.39-3.13 mg/kg, i.v.) reduced the mean blood pressure and caused an increase in the respiratory air rate in anesthetized rats. At 1.5 x 10(-6)-1.5 x 10(-5) M, THP markedly relaxed a contraction induced by 10(-7) M norepinephrine in rat aorta with endothelium but not in that without endothelium. At a dose of 0.02-0.5 mg, THP produced an increase in the contractile force and the perfusion flow of isolated perfused guinea pig hearts. At a higher concentration (4.5 x 10(-5)-1.5 x 10(-4) M), it produced a slight increase in the contractile force of the left atria in guinea pigs. This positive inotropic action of THP was inhibited by diphenhydramine (10(-6)-5 x 10(-5) M), chlorpheniramine (3 x 10(-7)-3 x 10(-5) M), and tripelennamine (3 x 10(-7)-3 x 10(-5) M) but not by propranolol (10(-6) M), cimetidine (10(-5) M), diltiazem (10(-6) M), or ryanodine (10(-8) M). THP given i.v. at 2.5 mg/kg elevated the plasma histamine level in anesthetized dogs. From these data, we conclude that THP mainly relaxed the rat aorta in the presence of endothelium and that at higher concentrations, it increased the contractile force in the cardiac muscle, probably mediated through the release of histamine.

Animals↗
PubMed1991

12-Keto steroidal glycosides from the caudex of Yucca gloriosa.

Eight new steroidal glycosides, tentatively named YS-VI, -VII, -VIII, -IX, -X, -XI, -XII and -XIII were isolated from the caudex of Yucca gloriosa along with P-1, YG-2 and YG-3 previously obtained from flowers. The structures of five of these compounds were elucidated as mexogenin 3-O-beta-D-glucopyranosyl-(1----2)-beta-D-galactopyranoside (YS-VI), gloriogenin 3-O-beta-D-glucopyranosyl-(1----2)-[beta- D-glucopyranosyl-(1----3)]-beta-D-glucopyranoside (YS-VII) and 3-O-beta-D-glucopyranosyl-(1----2)-[beta-D-glucopyranosyl)-(1----3)]- beta-D-galactopyranoside (YS-VIII), manogenin 3-O-beta-lycotetraoside (YS-IX) and 3-O-alpha-L-rhamnopyranosyl-beta-lycotetraoside (YS-X), respectively, on the basis of chemical and spectral evidence.

Carbohydrate Sequence↗
PubMed1991

12-Hydroxy steroidal glycosides from the caudex of Yucca gloriosa.

The structures of the new steroidal saponins (tentatively named YS-XI, -XII and -XIII) have been isolated from the caudex of Yucca gloriosa and characterized as 3-O-beta-D-glucopyranosyl-(1----2)-beta-D-galactopyranosyl 5 beta- (25R)-spirostan-3 beta, 12 beta-diol, 3-O-beta-D-glucopyranosyl-(1----2)- [beta-D-glucopyranosyl-(1----3)]-beta-D-glucopyranosyl 5 beta- (25R)-spirostan-3 beta, 12 beta-diol and 3-O-beta-D-glucopyranosyl-(1----2)- beta-D-galactopyranosyl 5 beta-(25R)-spirostan-2 beta,3 beta,12 beta-triol, respectively.

Acetylation↗
PubMed1991

Production of antisera to acidic fibroblast growth factor and their application to immunohistochemical study in rat brain.

Antisera against acidic fibroblast growth factor purified from bovine brain were produced in rabbits and used for immunohistochemical study of the rat brain. When examined in an immunospot assay using a nitrocellulose membrane, the best antibody was capable of detecting 80 fmol of acidic fibroblast growth factor but failed to react even with up to 5 pmol of basic fibroblast growth factor. Using this antiserum, the immunohistochemical distribution of acidic fibroblast growth factor was examined in rat brain. Acidic fibroblast growth factor-like immunoreactivity was localized mainly in a subpopulation of ependymal cells and tanycytes, as well as in some glial cells. Positive ependymal cells were observed throughout the walls of ventricles, including the third ventricle and cerebral aqueduct. Immunoreactive processes of tanycytes were found extending from the ventral wall of the third ventricle to the brain parenchyma and surface. The most intense immunostaining was observed in circumventricular organs such as the organum vasculosum laminalis terminalis and the subfornical organ. Particularly in the latter organ, there was an extremely dense plexus of immunoreactive fibers and processes around the wall of capillaries. The present results suggest that the effects of acidic fibroblast growth factor on brain functions may be exerted through the circumventricular organs and/or ependymal cells.

Animals↗
PubMed1991

A histochemical study of bone remodeling during experimental apical periodontitis in rats.

An apical periodontitis experimental model was produced by means of opening the pulp chamber of the mandibular first molar in Wistar strain rats. In particular, the behavior of bone tissue in the vicinity of the root apex was investigated histochemically, ultrastructurally, and quantitatively. In addition, in order to demonstrate the effects of prostaglandin on the formation process of apical periodontitis, we examined the effects of indomethacin on bone remodeling during experimental apical periodontitis. These experiments suggested that prostaglandin may stimulate osteoclastic bone resorption and that the relationship between bone resorption and formation in apical periodontitis is a coupling phenomenon.

Acid Phosphatase↗
PubMed1991

Penetration, clearance and retention of antigen en route from the gingival sulcus to the draining lymph node of rats.

We investigated the penetration and clearance of antigen in the rat gingiva and the antigen-specific antibody response in the draining lymph nodes. Rats were primarily immunized into the alveolar submucosa with horseradish peroxidase (HRP) in complete Freund's adjuvant. Ultrastructural demonstration of antigen and specific antibody was performed by incubation of cryosections in an HRP solution, followed by peroxidase cytochemistry. Anti-HRP antibody-containing cells were observed in the draining lymph nodes from 2 to 9 weeks after immunization. The bulk of these cells were located in the medullary cords. The extracellular antibody and antibody-containing cells were also found in germinal centers (GCs) from 3 to 9 wk, and 3 wk, respectively, after immunization. The results suggest that the specific antibody response was most enhanced 3 wk after primary immunization. Therefore, at this time we further challenged rats with the topical application of HRP to the gingival sulcus. The results showed that antigen penetrated through the junctional epithelium into the underlying connective tissue and from here was cleared by macrophages or via the lymphatics. In the draining lymph nodes, antigen first appeared in the subcapsular sinus and eventually became retained within GCs. Between 3 and 5 days, the GCs of challenged rats contained more mature-type anti-HRP antibody-containing cells than those of non-challenged rats. The sequence of events observed suggests that antigen challenge applied topically to the gingival sulcus can induce the active GC reaction in the draining lymph nodes of immunized rats.

Animals↗
PubMed1991

Pirarubicin-induced endothelium-dependent relaxation in rat isolated aorta.

The mechanism of relaxation produced by pirarubicin [(2"R)-4'-O-tetrahydropyranyladriamycin, THP] has been studied in rat isolated aorta. THP (1.5 x 10(-6)-4.5 x 10(-5) M) markedly relaxed contractions induced by noradrenaline (10(-7) M) in the aorta with endothelium, but not in that without endothelium. The relaxation induced by 1.5 x 10(-5) M THP was inhibited by methylene blue (5 x 10(-6) M), hydroquinone (10(-4) M), phenidone (5 x 10(-5) M), haemoglobin (10(-6) M) and p-bromophenacyl bromide (5 x 10(-5) M), but not by indomethacin (2.5 x 10(-5) M). The relaxation induced by THP (1.5 x 10(-7) -4.5 x 10(-5) M) was inhibited by NG-nitro-L-arginine (10(-5) M), but enhanced by superoxide dismutase (10 units mL-1) or by L-arginine (10(-2) M). However, the THP-induced relaxation was not inhibited by various receptor antagonists such as atropine (10(-6) M), cimetidine (10(-5) M), diphenhydramine (3 x 10(-6) M) and [D-Pro4, D-Trp7,9,10]-substance P(4-11) (1.5 x 10(-6) M). In fifteen anthracycline analogues, THP and 13-dihydropirarubicin (both with a tetrahydropyranyl group) produced endothelium-dependent relaxations. These results suggest that the THP-induced relaxation which is probably mediated by endothelium-derived relaxing factor (EDRF) was not produced by an activation of muscarine, histamine H1 or H2, or substance P receptor, and further that the tetrahydropyranyl group must play an important role in the THP-induced relaxation.

Animals↗