Biomedical subjects

Y Murakami

Publications and source records attributed to Y Murakami.

At least 667 records · Page 37Linked to original sources

PubMed1992

Different biventricular remodelling of myosin and collagen in pulmonary hypertension.

1. To clarify the metabolism of contractile and non-contractile proteins of the ventricles during the development of right ventricular hypertrophy (RVH) and accompanying congestive heart failure (CHF) in response to a pressure overload, monocrotaline was injected subcutaneously into Sprague-Dawley (SD) rats. Myosin isoenzymes (MIE) were analysed by pyrophosphate gel electrophoresis under non-dissociating conditions. Acid-soluble collagens were analysed by an improved, noninterrupted sodium dodecylsulfate polyacrylamide gel electrophoresis (SDS-PAGE). Tissue collagen content was also measured after the estimation of hydroxyproline concentration in tissues. 2. Monocrotaline induced RVH, but not left ventricular hypertrophy, at 2 weeks after the injection of monocrotaline, with severe RVH with CHF present at 4 weeks. In the right ventricles (RV) treated with monocrotaline, MIE shifted significantly from V1 to V3 at 2 weeks. The shift of MIE was more pronounced at 4 weeks. The proportion of type III collagen increased significantly compared with controls at 2 weeks. At 4 weeks, the proportion of types III and V collagens increased significantly compared with controls. 3. In left ventricles (LV) treated with monocrotaline, a similar but less remarkable shift of MIE was observed without remodelling of collagen types at 2 and 4 weeks. The concentration of collagen in either the RV or LV treated with monocrotaline showed no significant changes at 2 and 4 weeks compared with controls. 4. These results demonstrate a remodelling of the contractile and non-contractile proteins during the development of RVH and accompanying CHF, and provide evidence for changes in protein metabolism of the counterpart of RV (i.e. the LV). These results may provide important insights into the pathophysiology of adaptive or non-adaptive cardiac hypertrophy in response to a pressure overload.

Animals↗

PubMed1992

Surfactant replacement therapy in premature babies with respiratory distress syndrome: factors affecting the response to surfactant and comparison of outcome from 1982-86 and 1987-91.

The impact of surfactant therapy on chronic lung disease remains uncertain. During the past decade (1982-91), over 300 babies with respiratory distress syndrome (RDS) weighing 501-2,500 g at birth were consecutively treated with surfactant-TA at our neonatal intensive care unit. Data on 95 RDS babies treated in the first 5 year period (Period 1, 1982-86) were compared with those on 158 RDS babies treated in the second 5 year period (Period 2, 1987-91). Overall respiratory improvement was better in Period 2 than in Period 1. In Period 2, surfactant therapy converted 98% of the babies with moderate/severe RDS to those with 'near normal' lung by 72 hr post-treatment. In Period 2, 95% of the surfactant-treated babies weighing 501-1,750 g at birth survived, 97% of which required no supplemental oxygen at 40 weeks corrected gestational age. Increased survival rate in the surfactant-treated babies during the past decade has not been followed by a parallel increase in chronic lung disease. The severity of the initial pulmonary disease per se was not the significant risk factor for chronic lung disease. Several other variables affecting the response to surfactant therapy and outcome have been identified by stepwise logistic regression analysis and include factors related to perinatal events such as birth asphyxia and infection, and other complications of prematurity.

Chronic Disease↗

PubMed1992

[Significance of normal oral flora, particularly group oral streptococci as defense mechanism against infection in healthy individuals (normal defense mechanism by oral Streptococcus group)].

The alpha-streptococci, consisted of normal oral flora mainly, with inhibitory activity against pathogenic microbes in healthy individuals was investigated by group A Streptococcus (indicator strain 6-22 nonmucoid T-12). Rate of alpha-streptococci with inhibitory activity against group A Streptococcus was increased as aging, and the rate in pre-school children was higher than that in school children. These results suggested that more than 90% of the tested alpha-streptococci with strong inhibitory activities (S. salivarius) against indicator strain had inhibitory activities against group A Streptococcus (mucoid T-6), H. influenzae, S. pneumoniae, group C Streptococcus, and from 40% to 70% of the tested strains had also inhibitory activities against other pathogens. As there were many strains of alpha-streptococci with inhibitory activities against pathogens, that usually detected in the upper respiratory infection, the problem on the strains in the future will explain significance of the defense mechanism against upper respiratory infection and this can be applied clinically.

Adolescent↗

PubMed1992

[Effect of methylrosanilinium chloride to MRSA nasal carriers].

Since the end of 1987, we have noticed an increasing incidence of Methicillin resistant Staphylococcus aureus (MRSA) among the inpatients of Yamanashi Medical College Hospital. MRSA strains were identified in 70-80 percent of the specimens obtained from patients with Staphylococcus aureus. From 1988 we performed yearly bacteriological examinations of the nares of medical personnel at Yamanashi Medical College Hospital. We treated nasal carriers with OFLX drop lotion or Povidone-iodine applied to the nares. In 1991 we treated eight nasal carriers, who had been unsuccessfully treated with Povidone-iodine, with 0.01% Methylrosanilinium Chloride ointment which was applied to the nares once a day for two weeks. A post-bacteriological examination again revealed that MRSA vanished from the nares of six nasal carriers. The minimum inhibitory concentration (MIC) of Methylrosanilinium Chloride was determined by the agar plate dilution method. The 100% MICs of MSSA were 1.0 microgram/ml and of MRSA were 1.0 microgram/ml by Methylrosanilinium Chloride. Moreover we examined the MICs of Methylrosanilinium Chloride against MRSA under the existing 5% Albumin, and consequently the 100% MICs were 4.0 micrograms/ml. Therefore a 0.01% Methylrosanilinium Chloride has sufficient efficacy against MRSA. The reaction of the skin and nasal mucosa to Methylrosanilinium Chloride was examined by using three groups of guinea pigs. 0.1% and 0.01% Methylrosanilinium Chloride ointment and hydrophylic poloid were applied to the nares and skin once a day for two weeks. Post-observation with an opticmicroscope revealed no significant findings. Methylrosanilinium Chloride shows good anti-Staphylococcus aureus ability. Further investigation is needed to determine if Methylrosanilinium Chloride has additional clinical application.

Animals↗

PubMed1992

Porphyromonas gingivalis fimbriae induce expression of the neutrophil chemotactic factor KC gene of mouse peritoneal macrophages: role of protein kinase C.

To account for infiltration of the periodontal tissues by neutrophils, the present study was undertaken to examine whether Porphyromonas gingivalis fimbriae, important structures involved in attachment of the bacteria to periodontal tissues, induce gene expression of the neutrophil chemoattractant KC in macrophages. The fimbriae induced expression of the KC gene of mouse peritoneal macrophages in a dose-dependent fashion. The peak of KC gene expression was observed as early as 1 h after initiation of the treatment. However, the gene expression was short lived, with the expression decreasing gradually after 6 h. A nuclear transcriptional assay showed that the fimbriae regulated the KC gene expression at a posttranscriptional level. We observed that the fimbria-induced KC gene expression was not regulated by endogenous or exogenous prostaglandin. Furthermore, forskolin, a potent activator of adenyl cyclase, and dibutyryl cyclic AMP were incapable of inducing KC gene expression of the peritoneal macrophages. H-8 and HA 1004, inhibitors of cyclic nucleotide-dependent protein kinases, had little effect on the fimbria-induced KC gene expression. On the other hand, the fimbria-induced KC gene expression was inhibited markedly by treatment with H-7, a potent inhibitor of protein kinase C. We also observed that phorbol 12-myristate 13-acetate, a specific activator of protein kinase C, induced KC gene expression of peritoneal macrophages in a dose-dependent fashion. In addition, the fimbria-induced KC gene expression was suppressed in the peritoneal macrophages pretreated for 24 h with phorbol 12-myristate 13-acetate. These results suggest that the KC gene expression was mediated through activation of protein kinase C and not through that of cyclic nucleotide-dependent protein kinases. The present study indicates that P. gingivalis fimbriae can induce gene expression of the neutrophil chemotactic factor KC by macrophages via protein kinase C and suggests that this factor may be involved in infiltration of neutrophils into the periodontal tissues of adult periodontal patients.

1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine↗

PubMed1992

Complementation by a cloned human ubiquitin-activating enzyme E1 of the S-phase-arrested mouse FM3A cell mutant with thermolabile E1.

A temperature-sensitive growth mutant tsFS20 isolated from mouse FM3A cells was identified as a mutant with thermolabile ubiquitin-activating enzyme E1 by transfection with a full-length cDNA encoding the human E1 enzyme and cell-cell hybridization with an authentic E1 mutant ts85 previously isolated from FM3A cells. The resulting transformants produced thermoresistant E1 activity. Upon shift-up of temperature, asynchronously growing tsFS20 cells showed multiple points of cell-cycle arrest. At the nonpermissive temperature, tsFS20 cells that had been synchronized at the G1-S-phase progressed and accumulated in the mid-S-phase, as evidenced by the absence of G2-specific cdc2 kinase activity, while ts85 mutant cells, the widely used E1 mutant, reached the G2-phase and were arrested. Thus, the E1 mutation seemed to be involved in progression in the S-phase as well as in the G2-phase in the cell cycle. Degradation of short-lived abnormal proteins in tsFS20 cells was decreased to about 50% at the nonpermissive temperature, while the block was fully restored to the wild-type level in the transformant cells. Relevance of the unusually high incidence of the temperature-sensitive E1 mutation was discussed in terms of the E1 as a determinant of heat tolerance of cells.

Animals↗

PubMed1992

Detection of DNA aberrations in human cancers by single-strand conformation polymorphism analysis of polymerase chain reaction products.

We have developed a simple, sensitive method, single-strand conformation polymorphism (SSCP) analysis, to detect a single nucleotide substitution in a DNA fragment amplified and labeled by the polymerase chain reaction (PCR). Mobility shift of single-stranded DNAs due to their specific conformations on non-denaturing polyacrylamide gel electrophoresis can reveal DNA aberrations. By the PCR-SSCP analysis of DNAs from surgical specimens of human cancers, mutated ras genes (17%) and aberrations of tumor suppressor p53 gene (53%) including loss of one of the two alleles and a mutation in the remaining allele were detected in lung carcinomas and aberrations of both of the p53 and retinoblastoma (RB) genes were detected exclusively in advanced hepatocellular carcinomas.

Carcinoma, Hepatocellular↗

PubMed1992

Dependence of endocochlear potential on basolateral Na+ and Cl- concentration: a study using vascular and perilymph perfusion.

Inside-positive endocochlear potential (EP) and high potassium concentration in the endocochlear duct are generated by transepithelial K+ transport in marginal cells of the stria vascularis. In order to estimate the degree of involvement of Na+ and Cl- in K+ transport in marginal cells, EP in guinea pigs was measured under artificial vascular and perilymphatic perfusion in situ. Na+ depletion due to both vascular and perilymphatic perfusion decreased EP by -10.0 +/- 4.1 mV (delta EP = -86 +/- 5.2 mV, n = 5) from the control value of 78 +/- 4.3 mV (p < 0.01). Cl- depletion due to vascular and perilymphatic perfusion also decreased EP by -10.0 +/- 4.9 mV (delta EP = 8.5 +/- 4.8 mV, n = 6) from the control value of 77 +/- 5.1 mV (p < 0.01). However, under either vascular or perilymphatic perfusion, even lowering of Na+ or Cl- concentration in the perfusate decreased EP only slightly compared to the results under both vascular and perilymphatic perfusion. Furosemide, a blocker of Na+/K+/2Cl- symport, decreased EP under vascular perfusion. This dependency of EP on basolateral Na+ and Cl- concentration strongly suggests that K+ transport by the marginal cell is dependent on the basolateral Na+ and Cl- concentration, and that Na+/K+/2Cl- symport is raised as a possible mechanism for Na+ and Cl- dependency of EP.

Animals↗

PubMed1992

[Immunohistological investigation of type IV collagen in the basement membrane surrounding the cancer nest (cancer nest membrane) of head and neck squamous cell carcinoma--its relation to frequency of cervical lymph node metastasis].

Lymphoducts and blood vessels exist in the stroma, while none can be detected in the cancer nest itself within cancerous tissue. This explains why metastasis of carcinoma cannot occur without the escape of tumor cells through the basement membrane surrounding the cancer nest into the stroma. Accordingly, observation of the continuity of the basement membrane, what we call the cancer nest membrane, is essential for elucidating the first step of metastasis. Since type IV collagen is the most important structure composing the basement membrane, investigation of the immunohistological localization and continuity of type IV collagen is of value in predicting the metastatic aggressiveness of squamous cell carcinoma. We therefore studied biopsy tissues from the advancing lesion of head and neck squamous cell carcinoma in 95 untreated patients. The tissues were fixed in 85% ethanol and embedded in paraffin, and 5-um thin sections prepared were then immunohistochemically stained for type IV collagen by the ABC method for observation of the continuity status of the cancer nest membrane in relation to metastasis. The basement membranes of normal mucosal epithelium and normal interstitial capillaries were utilized as positive controls, and negative controls were obtained by using PBS in place of the primary antibodies for the immunohistochemical reaction. Membrane discontinuity (breaks or absence) correlated significantly with cervical lymph node metastasis, while intact membrane was associated with a low frequency of cervical lymph node metastasis. There was no obvious relation between the clinical T category and the continuity of the membrane; pN (+) carcinomas with membrane discontinuity included even T1 supraglottic and hypopharyngeal carcinomas, as well as T2 or higher oral mucosal carcinomas and T3 or higher glottic carcinomas, suggesting variation with tumor site. Hypopharyngeal and supraglottic carcinoma was associated with membrane discontinuity and a high incidence of cervical lymph node metastasis. On the other hand, glottic and oral carcinoma more often presented with intact membranes and had a lower incidence of metastasis, although carcinomas in these sites that did present with discontinuity of the membrane were associated with a high incidence of cervical metastasis. Therefore, observation of the continuity of the cancer nest membrane by the expression of type IV collagen may be useful in selecting better specific therapies and determining the necessity of prophylactic neck dissection. A correlation between the degree of tumor differentiation and the continuity of the membrane was also found; well-differentiated tumors with discontinuity of the membrane were frequently associated with cervical lymph node metastasis.(ABSTRACT TRUNCATED AT 400 WORDS)

Adult↗

PubMed1992

[Adenoid cystic carcinoma of the head and neck: a clinical review of 29 cases].

Pathological data and the outcomes of 29 patients with adenoid cystic carcinoma of the head and neck treated between 1975 and 1990 were reviewed. Patients consisted of 21 females and 8 males, with a median age of 59 years. The overall 5-year and 10-year survival rates determined by Kaplan-Meier analysis were 84.2% and 52.9%, respectively. Patients in whom pathological data indicated a frequent solid pattern of carcinoma had high incidences of metastasis and poor prognoses. The effectiveness of local control was found to have no relation to the pathological data of the tumor, but rather depended upon whether anatomical limitations restricted complete resection of the tumor. All 7 patients who had cervical lymph node metastasis underwent neck dissection, which was useful in controlling metastatic spread. Distant metastases were present in 6 patients, and the lung was the most frequent site of metastasis.

Adult↗

PubMed1992

[Immunohistological investigation of epithelial components of adenolymphoma of the parotid gland].

In order to develop a more objective method of evaluating the origin of adenolymphoma, we immunohistochemically investigated the expression of cytokeratins, vimentin, S-100 protein, and alpha-smooth-muscle actin using the avidin-biotin-peroxidase (ABC) method in ethanol-fixed paraffin-embedded specimens from 8 adenolymphomas. Several kinds of monoclonal antibodies which react monospecifically with each subclass of cytokeratins were used. Results were compared with specimens of 8 normal parotid glands by radical neck dissection in patients with other diseases who had not undergone radiotherapy. In the adenolymphoma specimens, basal cells were strongly positive for CK-6, but reactivity of columnar cells was apparently reduced. In contrast, columnar cells were strongly positive for CK-7, but reactivity of basal cells was reduced. In normal parotid gland specimens, CK-7 was also detected in all columnar cells in the ductal system, although some duct cells around the columnar cells, which showed strong CK-6 expression, showed poor CK-7 expression. alpha-smooth-muscle actin was present in myoepithelial cells in normal parotid gland specimens, but not in basal cells of adenolymphoma or of the normal ductal system, which were CK-6-positive. As these characteristic findings were consistently observed in all specimens, the demonstration of CK-6, CK-7, and alpha-smooth-muscle actin may be useful in the recognition and classification of columnar and basal cells. CK-8 was present in both columnar and basal cells of adenolymphoma and of the normal duct, but in the normal parotid gland, acinus cells were also strongly positive for CK-8.(ABSTRACT TRUNCATED AT 250 WORDS)

Actins↗

PubMed1992

[An immunohistological study of normal parotid gland].

Cytoskeletal proteins from each epithelial component of the parotid gland were studied immunohistologically using monospecific monoclonal antibodies, and we obtained several interesting results: 1) The expression of vimentin, S-100 protein and GFAP were essentially unrecognizable. 2) The expression of alpha-actin was recognized only in myoepithelial cells, and was negative in other tissues. 3) The expression of CK-3, CK-6, CK-7, CK-8 and CK-18 was commonly recognized in both acinal and ductal cells. 4) The expression of CK-13 and CK-19 was recognized in ductal cells, but was negative in acinal cells. 5) We propose that the characteristic cell be referred to as a "duct satellite cell", as it comprises part of the intercalated duct and is sporadically localized around striated and layer ducts. 6) These duct satellite cells express all subclasses of cytokeratin observed in myoepithelial, acinal and ductal cells. 7) The duct satellite cells observed in this study are most likely to correspond to the undifferentiated reserve cells described in "bicellular theory", and we speculate that all epithelial tissues of the parotid gland originate from these cells.

Actins↗

PubMed1992