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Biomedical subjects

Y Homma

Publications and source records attributed to Y Homma.

At least 163 records · Page 9Linked to original sources
PubMed1994

Corticobasal degeneration: etiopathological significance of the cytoskeletal alterations.

We have studied brain tissues from three patients with corticobasal degeneration (CBD) histologically, ultrastructurally and immunohistochemically. Ballooned neurons in the cerebral cortex and severe degeneration of the substantia nigra were observed in them all and weakly basophilic neurofibrillary tangles (NFTs) were distributed widely in the basal ganglia and brain stem. Ultrastructural examination demonstrated that the NFTs comprised characteristic 15-nm-wide straight tubules, which showed positive immunohistochemical staining with an antibody against tau, but not ubiquitin. Tau-immunoreactive neuronal cell bodies without NFTs also were found in the cerebral cortex and subcortical nuclei, predominantly in the brain stem, and the greatest number of tau-positive glial inclusions occurred in the cerebral gray and white matter of the pre- and post-central gyri. These inclusions comprised tubular structures with diameters of about 15 nm and were localized in the oligodendroglial cellular cytoplasm and processes. These findings indicate that there is a close cytoskeletal pathological relationship between CBD and progressive supranuclear palsy.

Aged↗
PubMed1994

Effects of bezafibrate therapy on subfractions of plasma low-density lipoprotein and high-density lipoprotein, and on activities of lecithin:cholesterol acyltransferase and cholesteryl ester transfer protein in patients with hyperlipoproteinemia.

We investigated the effects of 12 weeks of bezafibrate treatment on plasma lipoprotein subfraction levels and on activities of LCAT and CETP in 25 patients with hyperlipoproteinemia. Bezafibrate reduced plasma levels of VLDL-TC and VLDL-TG by 69% and 66% (P < 0.001) and plasma levels of IDL-TC and IDL-TG were decreased by 37% and 31% (P < 0.01). Bezafibrate had no significant effects on plasma levels of LDL1 (1.019 < d < 1.045)-TC and LDL1-TG in the study population as a whole but significantly increased the plasma level of LDL1-TC in the subgroup of 9 patients with type IV hyperlipoproteinemia. Bezafibrate reduced plasma levels of LDL2 (1.045 < d < 1.063)-TC, LDL2-TG by 48% and 44% (P < 0.001) in both type II and type IV hyperlipoproteinemic patients. Gradient polyacrylamide gel electrophoresis revealed a decrease in small LDL particles. Bezafibrate did not affect the plasma level of HDL2-TC but reduced the HDL2-TG concentration significantly (P < 0.001). Bezafibrate increased the plasma level of HDL3-TC by 37% and reduced the HDL3-TG level significantly by 20% (P < 0.001). Gradient polyacrylamide gel electrophoresis revealed an increase in HDL3a and a decrease in HDL2a. Bezafibrate suppressed the activities of LCAT and CETP by 21% (P < 0.001) and 17% (P < 0.01), respectively. The bezafibrate-induced decrease in plasma levels of small, heavy LDL might be related to its inhibition of LCAT and CETP activities which resulted in suppression of heteroexchange of HDL-EC with triglyceride in large, light LDL. The bezafibrate-induced increase in large HDL3 (HDL3a) could not be explained solely by its suppression of LCAT and CETP activities. The decrease of plasma small, heavy LDL as well as TG-rich lipoproteins by bezafibrate seems to be beneficial for prevention of atherosclerotic diseases.

Adult↗
PubMed1994

Transurethral ultrasound-guided laser-induced prostatectomy (TULIP) for benign prostatic hyperplasia: clinical utility at one-year follow-up and imaging analysis.

OBJECTIVE: The clinical utility of transurethral ultrasound-guided laser-induced prostatectomy (TULIP) for benign prostatic hyperplasia (BPH) and the laser effect on prostatic tissue were investigated. METHODS: TULIP was carried out under epidural anesthesia on 30 patients with symptomatic BPH (aged 63-92 years; mean, 73.9 years). RESULTS: Excluding 4 cases that were lost to follow-up, the mean modified Boyarsky symptom score significantly improved (P < 0.001) from a preoperative level of 22.2 +/- 5.3 to 7.7 +/- 4.3 at three months and 6.2 +/- 4.1 at one year. Maximum flow rate increased from 7.9 +/- 3.4 mL/sec to 14.5 +/- 5.9 mL/sec at three months and 14.7 +/- 6.3 mL/sec at one year (P < 0.001). A decrease in residual urine volume from 72 +/- 65 mL to 10 +/- 18 mL at three months and 16 +/- 17 mL at one year was also noted (P < 0.005). Transrectal ultrasonography revealed that estimated prostate volume was decreased from 39.7 +/- 20.4 mL to 26.9 +/- 20.3 mL at three months (P < 0.05) but it regrew to 32.2 +/- 26.2 mL at one year. Magnetic resonance imaging clearly showed less enhanced area to a depth of approximately 10 mm in the periurethral region, which could be attributable to coagulation necrosis in the prostatic tissue. Adverse effects were limited to epididymitis in 2 cases and no sexual dysfunction was associated with the procedure. CONCLUSIONS: TULIP is an effective and safe alternative procedure to induce long-lasting relief of prostatic obstruction by coagulation necrosis in the periurethral region.

Aged↗
PubMed1994

Effect of alpha-interferon alone and combined with other antineoplastic agents on renal cell carcinoma determined by the tetrazolium microculture assay.

The antiproliferative effect of various alpha-interferons (alpha-IFNs), alone or combined with other agents, on a renal cell carcinoma cell line was evaluated by the tetrazolium microculture assay to examine the rationale for combination therapies. Cells incubated in 96-week microculture plates at 5 x 10(3)/well were exposed to various agents for 3 days. There were no obvious differences in the growth inhibition caused by the 5 kinds of alpha-IFN examined as single agents. The combination of alpha-IFN with the following agents was also assessed: 5-fluorouracil (5FU), methotrexate (MTX), mitomycin C, bleomycin, cis-diaminedichloroplatinum (CDDP), vinblastine, etoposide (ETOP), alpha-IFN, tumor necrosis factor-alpha (TNF), and alpha-difluoromethylornithine. Synergism was observed for the combination of alpha-IFN+TNF, while the other combinations had additive or subadditive effects. No interference or antagonism was found. Trimodal combinations of alpha-IFN+MTX with either 5FU, ETOP, or CDDP all showed subadditive effects. These results indicated that an increased antiproliferative effect, although not necessarily synergistic, was obtained by the combination of alpha-IFN with a variety of antineoplastic agents, providing a rationale to seek for combination therapies including alpha-IFN for treating renal cell carcinoma.

Antineoplastic Agents↗
PubMed1994

In vivo, in vitro correlation of acetylcholine airway responsiveness in sensitized guinea pigs. The role of modified epithelial functions.

Many attempts have failed to correlate in vivo airway responsiveness with in vitro airway smooth muscle functions. We have reexamined this relation by taking account of airway epithelial functions in guinea pigs sensitized with inhaled ovalbumin (OA). In vivo responses were assessed by the provocative concentration of acetylcholine (ACh) required to double the airway opening pressure (PC200) under mechanical ventilation. In vitro responses were measured in a perfused whole-tracheal preparation. The negative logarithm of the molar concentration of ACh required to produce a 10% reduction in diameter was calculated both for epithelial-side stimulation (PC10(in)) and for serosal-side stimulation (PC10(out)). OA-sensitized guinea pigs showed significantly smaller log PC200 than control animals (0.51 +/- 0.07 and 0.81 +/- 0.10, respectively, p < 0.01). In in vitro study, there were variable differences in PC10(in) and PC10(out) in each animal. The difference in sensitivity between epithelial- and serosal-side stimulation (PC10(in-out)) showed a significant correlation in PC10(in) (r = 0.82, n = 9, p < 0.01) but not to PC10(out) (r = 0.39, p > 0.1), indicating that the variation in PC10(in-out) resulted from the changes in PC10(in). For in vivo-in vitro correlation, log PC200 correlated significantly with PC10(in) (r = 0.68, n = 9, p < 0.05) but not with PC10(out) (r = 0.18, p > 0.1). These results indicate that the sensitization by inhalation of OA produces increased airway responsiveness to ACh in vivo and that this airway responsiveness may be related, at least in part, to the altered airway epithelial functions.

Acetylcholine↗
PubMed1994

Gamma-interferon modifies guinea pig airway functions in vitro.

Cytokines produced by T-lymphocytes may have significant roles in the airway inflammation seen in bronchial asthma. Gamma interferon (IFN-gamma), a T-cell derived cytokine, is known to modify functions of both immune and non-immune cells. In this study, we investigated whether IFN-gamma can modify guinea pig airway functions in vitro. The isometric tension of guinea pig airway strips was measured in a tissue bath filled with Krebs-Henseleit solution. Contracting responses to carbachol and KCl, and the relaxing response to isoproterenol (ISO) were examined. Effects of IFN-gamma were examined by comparing responses of the strips incubated with or without IFN-gamma (1000 U.ml-1; 25,000 U.ml-1). Contracting responses to carbachol and KCl were not affected by the incubation with IFN-gamma other than slight increased in maximum contraction by carbachol after 5 hours incubation with 25,000 U.ml-1 of IFN-gamma. Both 1 and 5 h incubation of strips with 25,000 U.ml-1 IFN-gamma significantly increased the sensitivity to ISO (p < 0.01 and p < 0.05, respectively) without affecting maximum relaxation. The effect of IFN-gamma on ISO relaxation was abolished by the denudation of airway epithelium from strips, indomethacin (2 microM), and cycloheximide (70 microM) but not by N omega-nitro-L-arginine methyl ester (30 microM). In addition, heat-inactivated IFN-gamma and bacterial endotoxin (LPS, 0.625 pg.ml-1) had no effect on ISO relaxation. These results suggest that IFN-gamma is able to modify airway smooth muscle response to beta-adrenergic agonist by inducing release of prostanoids from airway epithelium.

Animals↗
PubMed1994

[Phospholipid metabolism regulated by heterotrimeric G proteins].

Phosphoinositide-specific phospholipase C (PI-PLC) catalyzes the hydrolysis of phosphatidylinositol 4,5-bisphosphate to inositol 1,4,5-trisphosphate (IP3) and diacylglycerol. IP3 induces the release of Ca2+ from intracellular stores, and diacylglycerol acts as the physiological activator of protein kinase C. Several distinct PI-PLC enzymes have been identified from various cells. Based on the primary sequences, PI-PLC isozymes are divided into three families: PLC-beta, PLC-gamma, and PLC-delta. Substantial evidence has strongly suggested that G proteins regulate PI-PLC in various cell-stimulation systems and that there might be two distinct pathways (pertussis toxin-sensitive and pertussis toxin-insensitive). Recently, it has become apparent that beta-type PLC isoforms are activated by the heterotrimeric G protein subfamily Gq. Careful studies using in vitro and in vivo reconstitution systems have further suggested that the alpha-subunits of Gq/11/16 specifically regulate PLC-beta 1 and PLC-beta 3 and that the beta gamma -subunits of the Gi subfamily interact with PLC-beta 2, which are considered to be responsible for the pertussis toxin-insensitive and the pertussis toxin-sensitive pathways, respectively. In this paper, involvement of G proteins in the regulation of phospholipase A2 and phosphatidylcholine-specific PLC and PLD is also discussed.

Animals↗
PubMed1994

Clinical characteristics of idiopathic interstitial pneumonia (IIP) with bullae.

Multiple bullae have often been observed in the lungs of patients with idiopathic interstitial pneumonia (IIP). The etiology of bullae has been considered to be distinct from that of interstitial pneumonia and honeycomb lesions seen in IIP. The incidence of bullae was evaluated in 27 IIP patients (male; 23 cases, female; 4 cases) and clinical factors which are related to the development of bulla were analyzed. Of the 27 patients, 16 (59%) had bullae. All 16 were male smokers, and had higher smoking indices (p < 0.01) than patients without bullae. Eleven of the 16 IIP patients with bullae had clubbed fingers (69%, p < 0.05). Roentgenologically, cysts (75%, p < 0.05), low attenuation area (56%, p = 0.06), and honeycomb appearance (94%, p = 0.07) were observed more often in IIP patients with bullae. These results suggest that smoking habits may have a close relationship to the development of bullae seen in patients with IIP.

Aged↗
PubMed1994

[Treatment of advanced prostatic cancer--chronological change between 1975 and 1991].

A chronological analysis of the clinical features and treatments of advanced prostatic cancer, stages C and D, was performed in 154 cases treated from 1976 through 1991. These cases were divided into two chronological groups: 61 cases treated between 1976 and 1983, and 93 cases between 1984 and 1991. Concerning demographic features and diagnosis, the number of patients with lymph node metastasis was higher in the latter group. There was also increase in cases who were urologically asymptomatic and detected by checkup digital rectal examination or by the elevation of serum prostatic tumor markers. Histopathological differentiation was consistent between the two groups; more than 70% of cancers were moderately and poorly differentiated adenocarcinoma. As for the treatment, total prostatectomy was performed in eight cases in the latter against none in the earlier, but hormonal therapy remained the main treatment throughout the periods: 74.2% in the earlier and 70.7% in the latter. However the methods of the therapy have clearly changed; estrogens and castration were used less often in the latter period, while LH-RH analogues and antiandrogens replaced them although the therapy was equally effective in 82.3% of the cases in the earlier and in 90.4% in the later period and five-year survival rate and the progression-free survival rate at three years showed no significant difference between the two periods. These results showed 1) refined quality of diagnosis 2) a change in mode of hormonal therapy and 3) no detectable improvement of survival in these 16 years. Development of more effective therapies would be warranted for a better survival.

Aged↗
PubMed1994

[Objective and subjective response in stage D2 prostate cancer patients with cancer pain].

Fourty-eight patients with stage D2 prostate cancer, initially treated with endocrine therapy at the University of Tokyo between 1981 and 1990, were followed up and analysed. For the assessment of a subjective response, pain score, narcotic score, and performance stages (PS) were used. Of the fourty-eight patients, twenty-one suffered from cancer pain due to bone metastases. These patients showed significantly (p < 0.01) more lesions of bone metastases and higher PS, compared with patients without cancer pain. The progression free survival of these patients was significantly (p < 0.01) lower than that of patients without cancer pain, although the actuarial survival was not significant. In twenty-one patients with cancer pain, the objective and subjective response rates to endocrine therapy were 75% and 86%, respectively. The duration of pain relief was 1.25-54 (median 19) months. Those rates to anti-cancer chemotherapy in refractory patients (8 patients) previously treated with endocrine therapy were both 25% and those to additional administration of flutamide (FUL) or diethylstilbestrol (DES) in refractory patients (6 patients) were 33% and 100%, respectively. Although the duration of pain relief was 0.78-8 (median 2) months, the additional administration of DES or FLU led to pain relief and improved quality of life (QOL) in all 6 patients. Endocrine therapy such as LH-RH agonist and non-steroidal pure anti-androgen, which has no severe side effects, would be of great usefulness in stage D2 prostatic cancer patients with pain on the basis of efficacy and safety.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1994

[Influence of Lactobacillus casei on rat bladder carcinogenesis].

The inhibitory effect of Lactobacillus casei (L. casei) in superficial bladder tumors was investigated in an experimental study using N-butyl-N (4-hydroxybutyl) nitrosamine (BBN)-induced rat bladder cancer as an experimental system. The study consisted of two experiments; in a short-term experiment, the inhibitory effect of 6-week treatment with L. casei was assessed in vitro in terms of the capacity for agglutination by concanavalin A (Con A) of bladder epithelial cells in their incipient stage of malignant transformation induced by 1-week exposure to BBN. As a result, the number of bladder epithelial cell aggregates caused by Con A was significantly smaller in the L. casei-treated group than in the non-L. casei-treated group (p < 0.001). In a long-term experiment, treatment with L. casei of varying duration was investigated for effectiveness against bladder tumors induced by 7-weeks exposure to BBN that arose 22 weeks. The results indicate that both bladder weight and tumor volume per organ were significantly lower in the L. casei-treated than non-L. casei-treated group (p < 0.05). The inhibitory effect on these parameters was more pronounced with treatment with L. casei of longer duration. While there was no significant difference among the treatment groups in the degree of extension of induced malignancy, tumors with a high degree of extension (T1b, T2) developed only in the non-L. casei-treated group. The degree of malignancy of induced tumors was significantly lower in those groups receiving L. casei while BBN was being administered as compared to the non-L. casei-treated group (P < 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1994

Aldecalmycin, a new antimicrobial antibiotic from Streptomyces. I. Taxonomy, fermentation, isolation, physico-chemical and biological properties.

A new antibiotic, aldecalmycin, has been discovered in the culture broth of Streptomyces sp. MJ147-72F6. Aldecalmycin was purified by solvent extraction, Diaion HP-20 chromatography, silica gel chromatography, Sephadex LH-20 chromatography, HPLC and centrifugal partition chromatography. The 1H and 13C NMR spectra of aldecalmycin showed the presence of keto-enol tautomers. Aldecalmycin is equipotent in inhibiting the growth of sensitive and methicillin-resistant Staphylococcus aureus (MRSA).

Anti-Bacterial Agents↗
PubMed1994

Urinary symptoms and urodynamics in a normal elderly population.

Age-related changes in the lower urinary tract function were investigated by means of symptomatology and urodynamics. In the symptom study subjectively normal 168 males and 101 females aged over 30 were administered a questionnaire regarding urinary symptoms. The prevalence of symptoms gradually advanced with age and nocturia more than 2 times was dramatically increased up to a half in those aged over 70. In the urodynamic study involving 65 males and 51 females with low symptom scores, significant reduction with advancing age was noted for maximum flow rate in both sexes (males: r = -0.295, p < 0.05, females: r = -0.591, p < 0.01) and maximum detrusor pressure in females (r = -0.513, p < 0.01). There was a significant increase in residual urine in males (r = 0.473, p < 0.05); otherwise no consistent changes in cystometry and urethral pressure profile related to aging were detected. These results indicate that urinary symptoms and urodynamic variables may change with age even in "normal" subjects, and warrant a careful interpretation of them in the elderly subjects.

Age Factors↗
PubMed1994

[Evaluation of low-flow sevoflurane anesthesia].

Six of twelve ASA 1 or 2 patients were allocated to the low-flow sevoflurane anesthesia group (LFA) and the other 6 to the high-flow sevoflurane anesthesia group (HFA). Sevoflurane consumption of LFA was 1-7th of that of HFA. Soda lime temperature was maintained below 40.0 degrees C and there was no danger of toxic sevoflurane degradation products. The serum inorganic fluoride concentration increased with the rise in % hours (the amount of inhaled sevoflurane in percent multiplied by the length of time under anesthesia in hours), but did not reach the nephrotoxic level of 50 microM in any patient. We conclude that low-flow sevoflurane anesthesia is a safe and clinically useful anesthetic method.

Adult↗
PubMed1994

Clinical and flow cytometric analyses of renal cell carcinomas with reference to incidental or non-incidental detection.

In recent years renal cell carcinomas have been diagnosed as incidental findings. The tumors are usually associated with low stage and good prognosis. To find out if they might have a different malignant potential from suspected tumors, we retrospectively compared 56 cases of incidentally detected tumors with 84 cases of suspected tumors, with regard to tumor stage, nuclear grade, tumor size and DNA ploidy pattern as evaluated by flow cytometry. The incidentally detected tumors were lower in stage (P < 0.01), smaller in size (P < 0.01) and higher in probability of survival (P < 0.02) than the suspected tumors, as other studies have reported. Meanwhile, there was no difference in nuclear grade, DNA ploidy pattern and survival in stage I tumors between the two groups of renal cancers. The results suggest that the better prognosis in incidental renal cancer might be due to early detection rather than lower malignant potential of this specific type of renal cancer.

Adult↗