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Biomedical subjects

T Baba

Publications and source records attributed to T Baba.

At least 127 records · Page 7Linked to original sources
PubMed1999

Decreased expression of myotonic dystrophy protein kinase and disorganization of sarcoplasmic reticulum in skeletal muscle of myotonic dystrophy.

Pathological expression of myotonic'dystrophy protein kinase (DMPK) in skeletal muscle of myotonic dystrophy (DM) was studied by Western blot analysis, immunohistochemistry, and immunoelectron microscopy of DMPK. Western blot analysis showed that DMPK protein in DM skeletal muscles dramatically decreased. DMPK-positive muscle fibers showed typical DM pathological changes such as type I atrophy, central nuclei, nuclear chains, and sarcoplasmic masses. In degenerated DMPK-positive muscle fibers, cross-striated bands disappeared, and irregular granular DMPK-positive materials appeared in sarcoplasm. By immunoelectron microscopy, DMPK was localized in the terminal cisternae of the sarcoplasmic reticulum (SR) in DM muscle. Swollen DMPK-positive SRs were detected between well preserved myofibrils in the early stage of DM muscle degeneration, and degenerated intramembranous structures with DMPK and an accumulation of mitochondria were observed between disorganized myofibrils in degenerated DM muscle. We concluded that SR is the primary site of the degeneration of DM skeletal muscle and that the decreased DMPK might cause dysregulation of intracellular calcium metabolism, which is followed by DM muscle degeneration.

Adenosine Triphosphatases↗
PubMed1999

Difference of acrosomal serine protease system between mouse and other rodent sperm.

A fraction of acrosomal proteins dispersed during calcium ionophore A23187-induced acrosome reaction was prepared from cauda epididymal sperm of wild-type and acrosin-deficient mice, rat, and hamster. The acrosome-reacted sperm were further extracted by Nonidet P-40 to obtain the detergent-soluble protein fraction. Activities of serine proteases in the two protein fractions were examined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis in the presence of gelatin. A mixture of 42- and 41-kDa gelatin-hydrolyzing proteases was found in both fractions of the wild-type mouse sperm, whereas the acrosin-deficient mouse sperm contained the active 42-kDa protease and apparently lacked the activity of the 41-kDa protease. However, exogenous bovine pancreatic trypsin compensated for the absence of acrosin in the protein fractions of the mutant mouse sperm; the gelatin-hydrolyzing activity of the 41-kDa protease appeared when the sperm proteins of the mutant mice were treated with pancreatic trypsin. Two-dimensional polyacrylamide gel electrophoresis revealed that the 42- and 41-kDa proteases were distinguished from acrosin by the isoelectric point and immunoreactivity with affinity-purified antibody against an oligopeptide corresponding to the N-terminal amino acid sequence of mouse proacrosin. Moreover, the gelatin-hydrolyzing proteins corresponding to these two proteases were not detected in rat and hamster sperm, in spite of the treatment of the sperm extracts with pancreatic trypsin, and the total amount of gelatin-hydrolyzing activities in mouse was much smaller than those in rat and hamster. These results may reflect the difference of the serine protease system for the sperm penetration through the egg zona pellucida between mouse and other rodent animals, possibly explaining why the acrosin-deficient mouse sperm are capable of penetrating the zona pellucida.

Acrosin↗
PubMed1999

Extended survival of a porcine mitral bioprosthesis for 23 years: report of a case.

Limited durability is the major drawback of bioprosthetic valves, few of which survive for as long as 20 years. We report herein the case of a patient we recently encountered in whom a bioprothesis lasted for 23 years. To our knowledge, this is only the second case of such long survival. The patient was a 56-year-old man who was urgently admitted to our hospital with acute mitral regurgitation, 23 years after undergoing mitral valve replacement with a porcine bioprosthesis. Acute leaflet tears were found to be the cause of the mitral incompetence and the xenograft was successfully replaced with a mechanical valve. We believe that when reoperation is thought to carry a low risk, prophylactic surgery might be justified, even in patients without symptoms.

Bioprosthesis↗
PubMed1999

"In vivo cryotechnique" in combination with replica immunoelectron microscopy for caveolin in smooth muscle cells.

A novel "in vivo cryotechnique" with replica immunoelectron microscopy was developed for detecting caveolin localization on replica membranes prepared directly from living smooth muscle cells. After quick-freezing mouse duodenal walls by our "in vivo cryotechnique", the specimens were prepared for freeze-fracture and deep-etch replica membranes. Then they were treated with 5% SDS and 0.5% collagenase to keep some antigens on the replica membranes. The immunogold method could be used to clarify the localization of the caveolin antigen in relation to three-dimensional ultrastructures of living smooth muscle cells. Our new cryotechnique can provide native organization of functional molecules in living cells.

Animals↗
PubMed1999

Mycolic acid analysis in Nocardia species. The mycolic acid compositions of Nocardia asteroides, N. farcinica, and N. nova.

Mycolic acids from twelve Nocardia species were analyzed for structure using capillary gas chromatography and mass spectrometry. This high-resolution procedure permitted good separation of the trimethylsilyl (TMS) ether derivatives of mycolic acid methyl ester according to the total number of carbon and double bonds. The profiles of the mycolic acid molecular species were used as models to illustrate the difference in the structures of each species, even in the case of N. asteroides complex; N. asteroides, N. farcinica and N. nova. Although N. asteroides and N. farcinica had similar lengths of carbon skeleton, i.e., 51.9-53.7 was the average carbon number (Av.Nc.), they had different compositions of unsaturated acids. Mycolic acids from N. asteroides were composed of abundant saturated acids and less than 1% tetraenoic acids; mycolic acids from N. farcinica were composed of unsaturated acids, which were composed of abundant dienoic acids, 2-12% of tetraenoic acids and a trace of pentaenoic acids. In contrast, Av.Nc. of mycolic acids from N. nova were 55.7-56.3, which were relatively longer than those from N. asteroides or N. farcinica. Regarding the characteristics of the structure of alpha-branch, major components were C16:0 and C18:0 for N. asteroides 23206T, and C16:0 and C14:0 for N. farcinica 23157T, respectively. The presence of monounsaturated alpha-branch (C18:1 and C16:1) was characteristic of N. nova.

Gas Chromatography-Mass Spectrometry↗
PubMed1999

Analysis of factors related to jugular venous oxygen saturation during cardiopulmonary bypass.

OBJECTIVE: To investigate preoperative clinical conditions and/or intraoperative physiologic variables related to jugular venous oxygen saturation (SjO2) during cardiopulmonary bypass (CPB). DESIGN: Prospective study. SETTING: General hospital, single institution. PARTICIPANTS: One hundred forty patients (52 women, 88 men) who underwent coronary artery bypass grafting. MEASUREMENTS AND MAIN RESULTS: The authors measured SjO2 at five times during surgery. Multiple stepwise regression analysis showed a significant correlation of SjO2 with (1) arterial carbon dioxide partial pressure (PaCO2) before CPB (standard regression coefficient [(SC)] = 0.435), (2) cerebral perfusion pressure (CPP) during initiation of CPB (SC = 0.259), (3) PaCO2, tympanic temperature (TT), bubble oxygenator, and cerebral small infarctions (CSIs) during hypothermic CPB (SC = 0.507, -0.237, -0.192, and -0.189, respectively), (4) CPP, PaCO2, CSIs, and bubble oxygenator during rewarming (SC = 0.476, 0.294, -0.220, and -0.189, respectively), and (5) PaCO2 after CPB (SC = 0.480; p < 0.01). Correlation coefficients between SjO2 and CPP during rewarming were 0.40 (0.46 without CSI and 0.37 with CSI; p < 0.01). These results indicate that the relationship between CPP and SjO2 was significant in patients with CPP less than 40 mmHg during rewarming. CONCLUSION: During rewarming, when cerebral perfusion and oxygen demand change abruptly, but not during stable hypothermic CPB, CPP was a significant factor related to sjO2.

Aged↗
PubMed1999

Stimulatory effect of regucalcin on proteolytic activity in rat renal cortex cytosol: involvement of thiol proteases.

The effect of regucalcin, a calcium-binding protein, on neutral proteolytic activity in the cytosol of rat kidney cortex was investigated. Proteolytic activity was significantly increased in the presence of regucalcin (0.01-0.25 microM) in the enzyme reaction mixture. This increase was not significantly altered by the addition of CaCl, (0.01 and 1.0 mM) or EGTA (1.0 mM), indicating that the effect of regucalcin was independent on Ca2+. The effect of regucalcin to increase proteolytic activity was completely prevented in the presence of N-ethylmaleimide (5 mM), a modifying reagent of thiol groups. Proteolytic activity was clearly elevated by dithiothreitol (5 mM). This elevation was further enhanced by regucalcin (0.1 microM). Meanwhile, the stimulatory effect of regucalcin on proteolytic activity was not significantly altered in the presence of diisopropylfluorophosphate (2.5 mM), an inhibitor of serine proteases. Also, the regucalcin effect was not appreciably changed by the addition of EDTA (2.5 mM), a chelator of metal ions, indicating that it is not involved in metal-related proteases. These results demonstrate that regucalcin can increase proteolytic activity in the cytosol of rat kidney cortex. Regucalcin may activate thiol proteases independent on Ca2+.

Animals↗
PubMed1999

Epidermal tissue-derived T-cell growth factor, colony stimulating factor and nerve growth factor in chickens.

The purpose of this study was to determine the mechanism of the local cytokine-mediated immune response in the skin of chickens. The incorporation of 3H-thymidine into spleen T lymphocytes from 9-to 10-week-old chickens was augmented by the addition of epidermal tissue culture supernatant (ESN) from 11-day-old embryos. The colony formation of neonatal chicken bone marrow cells in the methylcellulose medium was also significantly increased by addition of ESN. When axonal outgrowth in matrigel was investigated, the embryonal sympathetic ganglion was found to grow axons outwards towards the epidermal tissue specimens. The above results suggest that chicken epidermal cells (probably keratinocytes) produce T-cell growth factor (corresponding to IL-1), colony-stimulating factor for macrophages (M-CSF) and granulocytes (G-CSF), and nerve growth factor (NGF).

Animals↗
PubMed1999

A case of hereditary amyloidosis transthyretin variant Met 30 with amyloid cardiomyopathy, less polyneuropathy, and the presence of giant cells.

Transthyretin-Met 30 (TTR-Met 30) is a variant of transthyretin and is usually associated with familial amyloid polyneuropathy. It is rare that patients with TTR-Met 30 will primarily develop amyloid cardiomyopathy. This report presents a patient with late-onset TTR-Met 30 who primarily developed amyloid cardiomyopathy, with less amyloid polyneuropathy in the peripheral nervous system than is usually seen. An autopsy was performed, and histological examination revealed many foreign-body giant cells and macrophages in the area of amyloid deposition that was found in nearly all of the organs.

Aged↗
PubMed1999

Removal of stem cell factor or addition of monoclonal anti-c-KIT antibody induces apoptosis in murine melanocyte precursors.

Previous findings indicate that the protein c-KIT and its ligand, stem cell factor (SCF) play a crucial role in the development of melanocytes from their precursors in the embryonic neural crest cells. Using a monoclonal anti-c-KIT antibody, ACK2, which is an antagonistic blocker of c-KIT function, we and colleagues demonstrated that mouse melanocytes disappeared with the injection of ACK2 during certain periods of embryonic and postnatal life. The precise mechanisms of this disappearance, however, remain unclear. Because melanocytes disappeared without any inflammation in these in vivo studies, we suspect that apoptosis was a main cause of their disappearance. In this study, to clarify the underlying mechanism, we studied whether ACK2 induces apoptosis in c-KIT-positive melanoblasts, which appear in mouse neural crest cells cultured with SCF from 9.5 d old mouse embryos. With an in situ apoptosis detection kit, a significant increase in apoptosis was detected after the removal of SCF, which further increased with the addition of ACK2 during SCF-dependent periods. The occurrence of apoptosis in the cultured cells was also demonstrated by a DNA analysis and electron microscopy. Immunohistochemical double staining confirmed that the apoptotic cells were c-KIT positive, and the electron microscopy showed that these apoptotic cells were melanocyte precursors. It was therefore demonstrated that apoptosis was induced in the SCF-dependent c-KIT-positive melanocytes in vitro when the SCF/c-KIT interaction was obstructed. These findings elucidate the mechanism of the regulation of melanocyte development, and the survival and proliferation of these precursor cells, by SCF/c-KIT interaction.

Animals↗
PubMed1999

Genotypes of alcohol-metabolizing enzymes in relation to alcoholic chronic pancreatitis in Japan.

Long-term consumption of large amounts of alcohol is the main cause of chronic pancreatitis. All heavy drinkers, however, do not contract chronic pancreatitis. Although genetic predisposition to alcoholism and alcoholic liver disease has been reported, genetic susceptibility to alcoholic pancreatitis is still a matter of debate. To determine the relation between genotypes of alcohol-metabolizing enzymes and chronic alcoholic pancreatitis, we examined genotype patterns of aldehyde dehydrogenase 2 (ALDH 2), alcohol dehydrogenase 2 (ADH 2) and cytochrome P-4502E1 (CYP2E1) in 54 patients with chronic alcoholic pancreatitis who were diagnosed in general hospitals in all over Japan and compared with those in 30 patients with chronic nonalcoholic pancreatitis or in 46 alcoholics with normal pancreatic function. There were no significant differences in the distribution of genotypes of ALDH 2 and CYP2E1 among those three groups. As for the ADH 2 genotype, distribution of 2(1)/2(1), 2(1)/2(2), and 2(2)/2(2) was 35%, 30%, and 35% in alcoholics with normal pancreatic function; 4%, 39%, and 57% in the chronic alcoholic pancreatitis group; and 0%, 50%, and 50% in the chronic nonalcoholic pancreatitis group, respectively. The frequency of ADH 2(2) allele was significantly higher in the chronic alcoholic pancreatitis group, compared with alcoholics with normal pancreatic function; but, it was not significantly different from that in the chronic nonalcoholic pancreatitis group. We also examined the relation between pancreatic fibrosis or pancreatitis histologically diagnosed and genotypes of alcohol-metabolizing enzymes in alcoholic autopsy cases. Twenty of 31 cases showed moderate or severe pancreatic fibrosis and showed intralobular + interlobular fibrosis, which is characteristic in alcoholic pancreatitis or intralobular fibrosis. ADH 2(2) allele tended to show a high frequency in the intralobular + interlobular fibrosis group, compared with that in the intralobular fibrosis group (75.0% vs. 41.7%, p < 0.1). The chronic pancreatitis group had a significantly higher frequency of the ADH 2(2) allele than that in cases without such findings (87.5% vs. 58.7%, p < 0.05). However, the ALDH 2 and CYP2E1 genotypes showed no significant relation to the findings of pancreatic fibrosis or histological pancreatitis. These data suggest that the risk of chronic alcoholic pancreatitis diagnosed clinically and pathologically seems to be associated with the ADH 2(2) allele in the genotypes of alcohol-metabolizing enzymes.

Alcohol Dehydrogenase↗
PubMed1999

Characterization of subclonal cell lines showing high motility derived from an undifferentiated human endometrial cancer cell line.

To examine the relationship between the morphology and the motility of cancer cells, we studied the difference between human endometrial undifferentiated cancer cell lines with different motilities, using light and electron microscopy, immunocytochemistry and RT-PCR. In a transplanted tumor of a cell line with high motility, many connective tissues and microvessels were observed and there were few intercellular spaces, which were ultrastructurally full of extracellular matrix. In the high-motility cell line only cytokeratin 19 was observed, and the level of cytokeratin 19 mRNA was elevated. Thus, motility is suggested to be related to the induction of connective tissues and cytoskeleton.

Animals↗
PubMed1999

Ultrastructural changes of erythrocyte membrane skeletons in chorea-acanthocytosis and McLeod syndrome revealed by the quick-freezing and deep-etching method.

The shapes of acanthocytic erythrocytes have been thought to be related to changes of the organization of the membrane components. In this study, acanthocytes from a patient with chorea-acanthocytosis and a patient with McLeod syndrome were examined. These acanthocytes had a greater tendency to form spikes than normal erythrocytes in an incubation culture system, indicating their weakness against membrane tension. The membrane skeletons of erythrocytes from both patients were examined by our erythrocyte-splitting method followed by the quick-freezing and deep-etching method. The ultrastructural organization of the membrane skeletons was heterogeneous even in individual erythrocytes, indicating regional changes in the compactness of their meshworks. In the process of erythrocyte splitting, some erythrocyte membranes became reversed and protruded into the cytoplasmic side. In these regions, there were fewer filamentous structures. The focal membrane skeletal changes, which are probably one of the factors that induce the phenotype of an acanthocytic erythrocyte, were demonstrated for the first time by this method.

Acanthocytes↗
PubMed1999

Relationship between polymorphism in the angiotensinogen, angiotensin-converting enzyme or angiotensin II receptor and renal progression in Japanese NIDDM patients.

We determined the relationship between the gene polymorphism of angiotensinogen (AGT), angiotensin-converting enzyme (ACE), or angiotensin II receptor (AT1R) and the progression of diabetic nephropathy in a multicenter trial of ethnically homogeneous Japanese patients with non-insulin-dependent diabetes (NIDDM). Gene polymorphism of ACE I/D, AGT M235T and AT1R A1166C was determined by polymerase chain reaction amplification using allele-specific primers. Japanese NIDDM patients (n = 1,152) were selected from several diabetic clinics. All patients were divided into three groups as follows: (1) group I (n = 407): normoalbuminuric patients; (2) group II (n = 327): microalbuminuric patients, and (3) group III (n = 418): overt albuminuric patients. Clinical factors for investigation in all patients were the date of birth, gender, levels of urinary albumin excretion, findings of the ocular fundus, duration of diabetes, hemoglobin A1c and blood pressure. It appears that genetic polymorphisms in the renin-angiotensin systems, i.e. ACE or AT1R, may affect the progression to renal failure of patients (especially females) with NIDDM.

Aged↗