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Biomedical subjects

S Murakami

Publications and source records attributed to S Murakami.

At least 253 records · Page 14Linked to original sources
PubMed1998

Transurethral ureterolithotomy in 100 lower ureteral stones.

A total of 100 patients with lower ureter stones received transurethral ureterolithotripsy (TUL) using a pulsed dye laser and/or a pneumatic lithotriptor. Extracorporeal shock wave lithotripsy treatment was added in 15 patients because fragments larger than 4 mm had been pushed back to the renal pelvis. The median stone size was 8 mm (range 3-22 mm). Operative time ranged between 3 and 157 min with a median of 30 min. Stone size correlated well with impaction, when impaction was defined as the inability of a guidewire to pass over the stone. Complete removal was defined as total clearance at 1 month without retreatment. The overall stone-free rate was 93%. Among the 7 not-stone-free cases, 5 cases were considered to have been treated successfully because asymptomatic residual fragments were smaller than 4 mm, 1 case required retreatment to become stone free, and 1 case with a silent residual fragment of 8 mm had been followed up for 3 months. The success rate was 98% when successful treatment was defined as total clearance or the presence of asymptomatic residual fragments of 4 mm or less without retreatment. Impaction was not a significant determining factor of stone-free rate (95.7 and 86.7%, respectively, p > 0.05) and in situ stone-free rate (TUL alone; 85.7 and 76.7%, respectively, p > 0.05). Two minor ureteral perforations were encountered. No patient required percutaneous nephrostomy or open surgery, or showed any late complications. TUL is a safe and successful method in managing lower ureteral stones.

Adolescent↗
PubMed1998

Immunologic aspects of facial nerve paralysis induced by herpes simplex virus infection in mice.

This immunologic aspects of facial nerve paralysis due to herpes simplex virus type 1 (HSV-1) infection were investigated in a mouse model system. Half of the 4- to 5-week-old mice developed facial nerve paralysis, whereas none of the 6-week-old mice died or developed facial nerve paralysis on inoculation with HSV-1. Six-week-old mice showed significantly higher titers of anti-HSV-1 neutralizing antibody than did 4-week-old animals. Passive transfer of either anti-HSV-1 antibody or HSV-1-immunized splenic T cells into 4-week-old mice 3 hours after HSV-1 inoculation prevented development of facial nerve paralysis and death, whereas such transfers 48 or 96 hours after HSV-1 inoculation did not prevent or exacerbate facial nerve paralysis. These results demonstrate that the age and the immunologic potency of mice are closely related to the pathogenesis of facial nerve paralysis. That facial nerve paralysis developed even in 6-week-old mice whose T-cell function was suppressed with anti-CD3 antibody suggests that virus-induced cellular demyelination is unlikely as a cause of facial nerve paralysis in this animal model.

Age Factors↗
PubMed1998

Effect of increased inner ear pressure on middle ear mechanics.

Velocity of malleus, umbo, and stapes footplate in response to stepwise increases up to +400 mm H2O in hydrostatic pressure of the inner ear was investigated in 10 fresh human temporal bones by using a laser Doppler interferometer. The sound-pressure input was 114 dB SPL, and the frequency range was 0.4 to 5.0 kHz. Static displacement of these sites was also measured by a video measuring system. When the inner ear pressure was increased, the malleus and stapes moved outward. Amplitude of umbo velocity decreased below 1.0 kHz with a slight increase around 2.0 kHz, whereas stapes velocity decreased at all frequencies with the major effect below 1.0 kHz. The phase angle of malleus umbo velocity advanced markedly in response to the increased inner ear pressure between 1.0 and 1.4 kHz. Change in the vibration of the umbo was thought to be primarily caused by an increased stiffness of the middle ear conduction system, and that of the stapes was caused by distention of the annular ligament and increased cochlear impedance produced by the increased inner ear pressure. These changes in TM vibration and its phase angle may help detect indirectly an elevation of inner ear pressure.

Aged↗
PubMed1998

Cytokine expression in periodontal health and disease.

Soluble proteins that serve as mediators of cell function and are produced by various cell types, such as structural and inflammatory cells, are collectively called cytokines. Several lines of evidence have revealed that cytokines play important roles not only in tissue homeostasis but also in the pathogenesis of many infectious diseases. Recent research on biological activities in normal periodontium and the pathogenesis of periodontal diseases has clarified the involvement of various cytokines in the biological activities observed in the sites. Cytokines play crucial roles in the maintenance of tissue homeostasis, a process which requires a delicate balance between anabolic and catabolic activities. In particular, growth factors--such as fibroblast growth factor (FGF), platelet-derived growth factor (PDGF), insulin-like growth factor (IGF), transforming growth factor-beta (TGF-beta)--are thought to play important roles in modulating the proliferation and/or migration of structural cells in the periodontium and the production of various extracellular matrices by these cells. On the other hand, there is little doubt that excessive and/or continuous production of cytokines in inflamed periodontal tissues is responsible for the progress of periodontitis and periodontal tissue destruction. Particularly, inflammatory cytokines--such as IL-1 alpha, IL-1 beta, IL-6, and IL-8--are present in the diseased periodontal tissues, and their unrestricted production seems to play a role in chronic leukocyte recruitment and tissue destruction. It is possible that monitoring cytokine production or its profile may allow us to diagnose an individual's periodontal disease status and/or susceptibility to the disease. In addition, although the hypothesis is still controversial, it has been suggested that discrete T-cell subsets (Th1 and Th2) with different cytokine profiles play specific roles in the immunopathogenesis of periodontal diseases.

Cell Division↗
PubMed1998

Prevalence of intellectual dysfunctioning and its correlates in a community-residing elderly population.

To examine the prevalence of intellectual dysfunctioning and its correlates in community-residing elderly people, a randomly selected sample of 1,405 people aged 65 and over living in Settsu, Osaka, were investigated in October 1992. Data for assessing intellectual dysfunctioning were obtained from 1,364 people (97.1%), excluding 21 clinically demented people (1.5%); 17.6/100, 5.6/100, and 3.3/100 of the population showed minor, moderate, and appreciable intellectual dysfunctioning, respectively, and the prevalence of intellectual dysfunctioning increased with age. By multivariate analyses using logistic regression, age over 75, poor general health, including current medical treatment, and psychosocial conditions such as no participation in social activities, no life worth living (no Ikigai), and anxiety about the future were independent risk factors for intellectual dysfunctioning. We conclude that intellectual dysfunctioning is closely associated with health and psychosocial conditions.

Aged↗
PubMed1998

Rapid diagnosis of varicella zoster virus infection in acute facial palsy.

Patients with zoster sine herpete and Ramsay Hunt syndrome without pathognomonic vesicles at the initial visit are often misdiagnosed with Bell's palsy and treated without antiviral agents. With PCR, we found that varicella zoster virus genomes were frequently detectable in auricular skin exudate from patients with zoster sine herpete or Ramsay Hunt syndrome before the appearance of vesicles.

Acute Disease↗
PubMed1998

Inhibitory effects of rolipram on partially purified phosphodiesterase 4 from rat brains.

Several previous studies have demonstrated that the phosphodiesterase 4 selective inhibitor rolipram affects cellular function at a much lower concentration than the reported Ki value for phosphodiesterase 4 inhibition. In this study, we examined the inhibitory effect of rolipram on rat brain phosphodiesterase 4 to determine the heterogeneity of the enzyme activity. Partial purification of various phosphodiesterases from the rat brain was performed by anion-exchange chromatography. The eluant was pooled into four fractions, two of which manifested cAMP-selective phosphodiesterase activity that was blocked by 10 microM of rolipram, indicating the presence of phosphodiesterase 4 in these fractions. The IC50 of rolipram (racemate) of these two fractions was 492 and 79 nM, respectively. The R-(-)-enantiomer of rolipram inhibited the cAMP-phosphodiesterase activity in the latter fraction 10 times more than did S-(+)-rolipram, and the inhibition of the former fraction was less stereospecific. Dixon plot analysis revealed that the rolipram enantiomers inhibited the cAMP-phosphodiesterase in the latter fraction in a multiphasic manner, with two Ki values, one at the micromolar level and the other at the sub-micromolar level, respectively, for both of the enantiomers. These results suggest that there is a heterogeneity for phosphodiesterase 4 in the rat brain, and some of the phosphodiesterase forms are sensitive to rolipram.

3',5'-Cyclic-AMP Phosphodiesterases↗
PubMed1998

Purification and characterization of two muconate cycloisomerase isozymes from aniline-assimilating Frateuria species ANA-18.

Two muconate cycloisomerases (MC I and MC II, EC 5.5.1.1) were purified to homogeneity from an aniline-grown Frateuria sp. ANA-18. MC I and MC II were similar in molecular mass, optimal pH, and pH stability but different in thermostability, and some other enzymatic properties. NH2-terminal amino acid sequences were different between the two isozymes, indicated that these are encoded by different genes. Different inducible production of MC I and MC II suggested that two catechol branches involved in the beta-ketoadipate pathway function in Frateuria sp. ANA-18.

Amino Acid Sequence↗
PubMed1998

Purification, characterization, and gene analysis of catechol 2,3-dioxygenase from the aniline-assimilating bacterium Pseudomonas species AW-2.

Catechol 2,3-dioxygenase (C23D; EC 1.13.1.2) was purified to homogeneity from a cell extract of Pseudomonas sp. AW-2 grown on aniline, and the purified C23D was characterized. The molecular mass estimated by gel filtration was 110 kDa. The enzyme dissociated into four identical subunits each with the molecular mass of 33 kDa. The enzyme had high activity for 3-methylcatechol as well as catechol, and differed from the enzyme from Pseudomonas putida mt-2, which carries the TOL plasmid, in optimal pH for catechol, extradiol cleavage activities for 3-methylcatechol and 4-methylcatechol, and immunochemical properties. The amino acid sequence deduced from a C23D gene, alnE, from Pseudomonas sp. AW-2 was 85.7% identical to that of 3-methylcatechol 2,3-dioxygenase from toluidine-assimilating Pseudomonas putida UCC22. AlnE was 44.1% identical to the C23D encoded by xylE in P. putida mt-2. Because XylE has low activity for 3-methylcatechol, these results suggest that the differences in substrate specificity for 3-methylcatechol among the C23Ds reflected their sequence similarity.

Amino Acid Sequence↗
PubMed1998

Finite element analysis of the lower lumbar neural arch under facet loading.

To evaluate the mechanical effect of the direction of facet load on the isthmus stresses of the lower lumbar neural arch, stress analyses were performed by using three-dimensional finite element models of isolated L4 and L5 vertebrae with particular emphasis on accurate discretization of the posterior elements. The bilateral symmetric or unilateral facet loads, with a constant magnitude, were applied within the sagittal and transverse planes. The largest maximal principal stress in the neural arch (the largest sigma(max)) tended to be qualitatively similar in L4 and L5. At the physiologic range, the largest sigma(max), observed on the anterior surface of the isthmus, was relatively insensitive to the sagittal plane loadings but sensitive to the transverse plane loadings. The values of the largest sigma(max) of L4 and L5 were low at the more frontally directed facet load. The magnitude and direction of the largest sigma(max) depended upon the facet loadings mainly on the ipsilateral side and partly on the opposite side. The results suggest that the direction of facet load, which may be characterized by the facet orientation, can have mechanical effects on the occurrence and direction of isthmic crack.

Computer Simulation↗
PubMed1998

Stimulation of cholesterol release from rabbit foam cells by the action of a new inhibitor for acyl CoA:cholesterol acyltransferase (ACAT), HL-004.

A new inhibitor of acyl CoA:cholesterol acyltransferase (ACAT), HL-004 [N-(2, 6-diisopropylphenyl)tetradecylthioacetamide], suppressed the synthesis of cholesterol [14C]oleate at 10(-9) approximately 10(-7) M in a concentration-dependent manner in both THP-1 cell-derived macrophages and foam cells prepared from aortic intima of rabbits fed a high cholesterol diet. Incorporation of [3H]cholesterol oleate-beta very low density lipoproteins was not inhibited by HL-004 at 10(-9) approximately 10(-7) M. Release of radioactivity from the cells loaded with [3H]cholesterol oleate-beta very low density lipoproteins was increased by the inhibition of ACAT activity with HL-004. HL-004 did not affect on acid and neutral cholesterol esterases. As a result, cholesterol ester content in foam cells decreased. These data suggested that HL-004 decreases cholesterol ester in foam cells by increasing the release of cholesterol and therefore might suppress atherosclerotic lesions.

Acetanilides↗
PubMed1998

[Results of resection of T3N0-2M0 non-small cell lung cancer according to involved organ and nodal status].

The purpose of this study was to evaluate the results of surgical treatment of T3N0-2M0 non-small cell lung cancer according to involved organ and nodal status. Between 1973 and July 1997, 157 patients with T3 non-small cell lung cancer were surgically treated in our department. Five-year survival was 23% for all cases, 35% for patients with curative resection, and 0% for patients with non-curative resection (p < 0.001). Five-year survival rate of patients with T3N0, T3N1, and T3N2 was 37%, 39%, and 3%, respectively (T3N0 vs T3N2, T3N1 vs T3N2, p < 0.01). According to the depth of chest wall involvement of T3N0 tumor, 5-year survival rate was 50% in the patients with the involvement of parietal pleura, 39% in the patients with the involvement of intercostal muscle, and 15% in the patients with the involvement of rib or more (parietal pleura vs rib or more, p < 0.05). In T3N0 patients with the involvement of only parietal pleura, the 5-year survival rate of parietal pleurectomy and en bloc chest wall resection was 43% and 46%, respectively (N.S.). Five-year survival rate of T3N1 patients with invasion in main stem bronchus was 46% and 3 of 5 patients of T3N0-1 tumor with pericardial invasion survived more than 5 years. From these results, T3N0 tumor involving chest wall without rib invasion, and T3N0-1 tumor involving main bronchus and pericardium are expected good survival. However, the prognosis of the patients with coexistent N2 disease or with incomplete resection remains poor in regardless with the type of involved organ. To correctly evaluate the surgical results of other types of T3 tumor, it is required to collect more cases or to perform multicenteric study.

Adult↗
PubMed1998

[Tobacco dependence].

The present review discusses the potential of nicotine psychic and physical dependence. Since the 1964 Surgeon General's Report on Smoking and Health, much attention has been given to nicotine dependence. Many epidemiological studies indicated that about 50% of smokers could be nicotine dependent; however, few of them had the experience of "progressive neglect of alternative pleasures or interest in favour of smoking." Additionally, some clinical and experimental data indicated that nicotine could not be considered more addictive than cocaine and morphine. As to the physical dependence on nicotine, the nicotine withdrawal syndrome is reported to be observed in about 30% of smokers. However, symptoms of the nicotine withdrawal syndrome are not specific but can appear in smokers put under stress. Several investigators have reported that signs of nicotine withdrawal in experimental animals are weaker than those with opioids, barbiturates and alcohol, and have indicated that it is unclear whether behaviors observed in animal models of nicotine physical dependence are signs of the nicotine withdrawal syndrome. From the current review, it can be considered that the potential for nicotine dependence may not be higher than that for other drug dependence and that nicotine physical dependence potential may be weaker than hitherto believed.

Animals↗
PubMed1998

[Trends of prostate cancer: comparison between 1986-90 and 1991-95 at Asahi General Hospital].

Patients with prostate cancer treated during 1986-95 were divided into two groups: the first five years as early period and the recent five years as late period. Background factors, therapeutic modality and prognosis were compared between these two groups. The number of patients during the late period (245) was about 1.5 fold that during the early period (161). The average age for each stage are similar within the same period, and also similar between early and late periods. Almost the same ratios were noticed on stage distribution and on histological grade between early and late periods. Therefore, the increase in the number of patients in recent years was due mainly to expansion with the same proportion of background factors. Patients with T2 and T3 during the late period received more aggressive treatments with/without endocrine therapy. Subsequently these patients seemed to show better prognosis than the patients during the early period. No differences in survival of patients with metastosis was revealed between these two periods. Therefore, the outcome was not improved by recent endocrine therapy.

Androgen Antagonists↗
PubMed1998

[Morphological transformation of sensory ganglion neurons and satellite cells].

Sensory ganglion neurons in higher vertebrates are unique in that they are pseudounipolar with a single stem process that divides at some distance from the cell body into central and peripheral processes. In the early stages of development, these neurons are bipolar but later they became pseudounipolar. This developmental process of sensory ganglion neurons with satellite cells was examined by scanning electron microscopy following removal of connective tissue. This pseudo-unipolarization began earlier but proceeded at a slower rate in chick than in rat embryos. This difference may due to the difference found in the extent and intimacy of satellite cell investments in these two animals, which was due to the fact that sensory neurons undergo pseudo-unipolarization only in the presence of satellite cells in vitro. The neuronal perikaryal projections were observed by scanning electron microscopy after removal of connective tissue and satellite cells. Morphometric analysis reveal that perikaryal projections were more numerous on the surface of mature pseudounipolar neurons than on the surface of premature bipolar neurons, and that the number of projections increased as the neuronal cell bodies grew larger. This may support the hypothesis that perikaryal projections are structural devices for increasing the neuron-satellite interface and for improving the efficiency of metabolic exchange between these two cell types. These results suggest that satellite cells play an important role in neuronal maturation.

Animals↗
PubMed1997

The transactivation and p53-interacting functions of hepatitis B virus X protein are mutually interfering but distinct.

Transactivation of viral and host genes expression by hepatitis B virus X protein (HBx) is believed to be involved in hepatocarcinogenesis. The interaction of HBx with the tumor suppressor p53 and its inhibitory effect on p53 functions have been reported recently. However, the question of whether p53 is directly involved in HBx transactivation has not yet been addressed. In this study, we delineated the interaction sites of HBx and p53 using far-Western blotting and glutathione S-transferase-resin pull-down assays. The results indicate that the HBx-binding sites are located within the oligomerization and specific DNA-binding domains of p53 and that the p53-binding site was confined to a small region in the HBx transactivation domain. Mutual interference of the transactivations by HBx and p53 was detected by CAT assays in a transient transfection system. Strikingly, transactivation by HBx was observed in the p53-negative cells, Saos-2 and Hep3B, indicating that the transactivation and the p53-inhibiting functions of HBx are mutually interfering but distinct.

Binding Sites↗