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Biomedical subjects

R Matoba

Publications and source records attributed to R Matoba.

At least 55 records · Page 3Linked to original sources
PubMed1995

Characteristics of chronic left ventricular dysfunction induced by coronary embolization in a canine model.

We have characterized the coronary vascular reserve, left ventricular function and inotropic response in dogs with chronic heart failure consequent to intracoronary embolization (EMB) with 50 microns spheres. We conducted studies 12-39 months after embolization and contrasted the findings with normal (CON) dogs. Acute embolization produced sustained LV volume enlargement and increased wall thickness, reduction of LV ejection fraction and elevated end-diastolic pressures; resting catecholamine levels were also increased. Responses to phenylephrine, nitroprusside, and dobutamine were identical in CON and EMB and coronary vasodilator reserve was reduced despite larger coronary vascular volume. Analysis by light microscopy showed a diffuse focal and interstitial fibrosis distributed uniformly from endocardium to epicardium associated with 14% loss of myocytes. This created a functional separation of myocardial muscle bundles and a disruption of the syncytial nature of the heart. Electron microscopy of the areas of fibrosis revealed myocytes in states ranging from normal appearing, to ghosts with evidence of cytolysis and loss of the sarcolemma. This model of chronic congestive heart failure with LV systolic dysfunction and elevated LV diastolic pressures shares a number of features with the syndrome in humans.

Animals↗
PubMed1994

The addition of 5'-coding information to a 3'-directed cDNA library improves analysis of gene expression.

Large-scale sequencing of a 3'-cDNA library permits one to analyse gene expression profiles in various tissues. However, many such sequences lack enough information about the encoded proteins. To overcome this problem, we tested a new library, consisting of a 3'-directed cDNA sequence fused to a to a 5' sequence of about 300 bp. Such 'joint molecules' of about 600 bp were amplified by PCR and directly sequenced. About 40% of these joint molecules included the 5' and 3' terminal portions of the mRNA, and most of the remaining clones contained the middle portion and 3' end of the mRNA. The upstream sequences contained sufficient information with which to search for similarity, ORFs, motifs and hydropathy, thus allowing the mRNAs to be categorized and their functions predicted. The rapid categorization of the cDNAs will help to sort those clones that merit further analysis.

Amino Acid Sequence↗
PubMed1994

Chromosomal assignment of HepG2 3'-directed partial cDNA sequences by Southern blot hybridization using monochromosomal hybrid cell panels.

Large-scale sequencing of a 3'-directed cDNA library from the human liver cell line HepG2 has generated several hundred species of cDNA gene signatures, about 85% of which identify novel genes. They are useful molecular landmarks for human genome mapping. We used 160 of these novel signatures as probes for Southern hybridization to human DNA. We then identified the copy number of the corresponding genes and assigned them to chromosomes, with reference to monochromosomal hybrid cell mapping panels. The distribution profile of the expressing genes among chromosomes suggested that the expressing gene density is not uniform.

Animals↗
PubMed1994

A human cDNA sequence homologue of bovine phosphatidylethanolamine-binding protein.

Sequencing of about 1000 3'-directed cDNA clones from the human HepG2 cell line revealed that about half of them represent transcripts of abundantly or moderately expressed genes, about 70% of which are novel. We identified one of these clones as encoding the human homologue of bovine phosphatidylethanolamine-binding protein.

Amino Acid Sequence↗
PubMed1994

Sudden death of a cocaine abuser.

We report an autopsy case of a 28-year-old male who died after intravenous use of cocaine. Cocaine and ecgonine methyl ester, the major metabolite of cocaine, were detected in the blood with gas chromatography/mass spectrometry. Postmortem examination showed contraction band necrosis together with patchy fibrosis and inflammatory cell infiltration in the heart. The sudden death appeared to be caused by a cardiac disorder associated with arrhythmia or coronary vasoconstriction.

Adult↗
PubMed1994

[Recommendations for preventing transmission of infection with biohazard in the practice of legal medicine (2). Equipment and practical applications. The Medico-Legal Society of Japan, Committee on Expert Opinions].

In May, 1993, our committee of the Medico-Legal society of Japan published an article entitled "Recommendations for Preventing Transmission of Infection with Biohazard in the Practice of Legal Medicine" in The Japanese Journal of Legal Medicine. Concerning this article, we received a lot of useful comments and opinions from many members of the society, for which we are very grateful. We also received a lot of requests for further information concerning details on the equipment and its practical applications. Since a lot of departments of Legal Medicine at several universities throughout Japan at present are remodelling their facilities in order to be able to perform autopsies, with respect to such circumstances, our committee felt the need to provide information on basic conditions concerning the prevention of transmission of infections with hazards.

Containment of Biohazards↗
PubMed1993

[Recommendations for preventing transmission of infection with biohazard in the practice of legal medicine. The Medico-Legal Society of Japan, Committee on Expert Opinions].

In Japan recently there arose a sudden need for special guidelines concerning medicolegal autopsy and the handling of medicolegal materials. In this respect, the Medico-legal Society of Japan, Committee on Expert Opinions has produced a guideline, entitled "Recommendations for Preventing Transmission of Infection with Biohazard in the Practice of Legal Medicine", which was then introduced to all members in Legal Medicine. This guideline contains First: Explanations about the most important types of Biohazard diseases, the dangers and ways of transmission. Second: Explanations concerning preventive measures in medicolegal autopsy, for handling of medicolegal materials and investigation samples, also concerning the equipment and tools within the autopsy room, as well as measures for correct disinfection. These guidelines, form the base on each department of the Medico-Legal Society of Japan, are asked to adjust their own practical manual in order to improve the safety of autopsy conditions.

Forensic Medicine↗
PubMed1992

Large scale cDNA sequencing for analysis of quantitative and qualitative aspects of gene expression.

Large scale sequencing of cDNAs provides a complementary approach to structural analysis of the human genome by generating expressed sequence tags (ESTs). We have initiated the large-scale sequencing of a 3'-directed cDNA library from the human liver cell line HepG2, that is a non-biased representation of the mRNA population. 982 random cDNA clones were sequenced yielding more than 270 kilobases. A significant portion of the identified genes encoded secretable proteins and components for protein-synthesis. The abundance of cDNA species varied from 2.2% to less than 0.004%. Fifty two percent of the mRNA were abundant species consisting of 173 genes and the rest were non-abundant, consisting of about 6,600 genes.

Base Sequence↗
PubMed1991

Tissue-specific and non-tissue-specific heavy-chain isoforms of myosin in the brain as revealed by monoclonal antibodies.

Four types of monoclonal antibody (BM-1, BM-2, BM-3 and BM-4) each having distinctive tissue specificity were obtained by immunizing mice with purified bovine cerebrum myosin. Both BM-1 and BM-2 reacted most efficiently with cerebrum myosin and less efficiently with myosins from other limited nonmuscle tissues, the tissue specificity of BM-1 being much narrower than that of BM-2. BM-3 reacted more efficiently with several other nonmuscle myosins than with cerebellar or cerebral myosin. BM-4 recognized various nonmuscle and smooth muscle myosins with a nearly equal efficiency. Cerebral myosin as well a cerebellar myosin contained two or more electrophoretic variants of the heavy chains. BM-1 and BM-3 as well as BM-2 and BM-3 were found to recognize selectively these distinct heavy-chain isoforms. The antigenic sites of the three tissue-specific antibodies (BM-1, BM-2 and BM-3) were all localized near the head/tail junction of the myosin molecules, while that of non-tissue-specific antibody BM-4 was near the center of the tail. These and additional results indicate that mammalian brain tissues as well as several other nonmuscle tissues contain multiple heavy-chain isoforms of myosin, the levels of which differed considerably from one tissue to another.

Animals↗
PubMed1991

Event-related brain potentials as indicators of visual recognition and detection of criminals by their use.

An event-related potential (ERP) was recorded, using photographs as stimuli, in 12 subjects for attended, 9 subjects for non-attended conditions and 14 subjects for a simulated criminal investigation. An ERP was detected only when a subject recognized a familiar image (target) mixed with other, unfamiliar images (non-target), regardless of whether he was asked to attend to or neglect the target image. ERPs in the subject who watched each picture but tried to ignore the relevant picture (non-attended) were more activated at the parietal region than at the central region, in contrast with ERPs in the subjects who paid attention to each picture without trying to ignore the relevant picture (attended). In the simulated criminal investigation, only a simulated thief, but not a simulated innocent subject elicited ERP only after the picture of a criminal site or thing was intermingled with pictures bearing no relationship to the crime. These findings indicate that the ERP using photographs as stimuli is useful as an objective indicator of crime-relevance.

Adult↗
PubMed1991

A novel system for large-scale sequencing of cDNA by PCR amplification.

We have developed a method for constructing a library containing the 3' end fragment of cDNA for large-scale sequencing of cDNA clones. The average size of the insert was 270 bp. Cell lysates that carry plasmids having the cDNA insert were subjected to PCR amplification of the cDNA moiety and the products were subjected to sequencing analysis using an autosequencer. With this protocol, sample preparation became a non-limiting step, that allowed us to sequence as many samples as the autosequencer could handle.

Base Sequence↗
PubMed1991

[Changes in lipid peroxides in methamphetamine treated rats].

Methamphetamine (MA) has many pharmacological effects. We measured lipid peroxides of MA treated rat by thiobarbituric acid (TBA) reaction to estimate the relationship between free radical reaction and pharmacological effects of MA. In this study we used rat which were injected 1 mg/kg/day MA for 2-10 weeks as the long term groups and which injected 10 mg/kg MA once as the acute groups. Although the acute groups were not different from the control groups, TBA reacting substance was increased in brains of more than 6 weeks treated rat and decreased in lungs of the same groups. These results indicate that lipid peroxidation might be related to chronic MA effects.

Animals↗
PubMed1991

Vital reactions in rat skin wounds by quantitation of fibrin.

The fibrin contents in contused skin wounds that were experimentally inflicted on rats were measured by a new method which was based on the determination of solubilized fibrin degradation products (FDP) using a latex agglutination test after plasmin digestion of tissue homogenates. The levels of FDP in ante-mortem wounds began to increase within 10 min after wounding and continued to increase for up to 6 h. The FDP levels in post-mortem wounds remained under the detection limit of the method used and were identical to those of intact tissues. The fibrin contents in the ante-mortem wounds prepared 2 days after death did not differ significantly from those prepared immediately. The results suggest that this method may be applicable to the identification of the vital reaction of the wound.

Animals↗
PubMed1991

ABO grouping of highly-dilute blood by the absorption-elution technique using nitrocellulose beads--application to a casework investigation.

This paper reports a homicidal case in which the absorption-elution technique using nitrocellulose beads as immunoadsorbents was successfully applied to ABO grouping from highly-diluted blood. A 21-year-old man was found dead in bed while staying in a hotel. He had multiple wounds over the entire body. By autopsy the cause of death was decided to be traumatic shock. The victim's blood group was A. A bucket filled with faint-colored water was found at the scene. By means of the absorption-elution technique using nitrocellulose beads the water was grouped as B. Later, a 32-year-old man staying in the hotel together with the victim was suspected and arrested. The suspect's blood group was B. He confessed that he had injured himself in the hands with a knife during the struggle and washed them in the water.

ABO Blood-Group System↗
PubMed1990

Proteolysis of myosin and troponin in human myocardium of elderly subjects.

Actomyosin was prepared from human myocardium and its protein composition was examined by SDS-polyacrylamide gel electrophoresis. For some preparations, particularly actomyosin isolated from elderly subjects, a high molecular weight (HMW) band (identified as a breakdown product of myosin heavy chain) appeared, while the troponin-T subunit decreased. Myofibril associated protease (MFP) activity showed no significant difference as a function of proteolysis. In agreement with the proteolysis of troponin-T and myosin, the Ca2+ sensitivity of Mg2(+)-ATPase activity decreased while the extent of the stimulation of Ca2(+)-ATPase by N-ethylmaleimide remained unchanged. This type of proteolysis would affect the Ca2(+)-dependent regulation of muscle contraction but not the contractility per se.

Actomyosin↗
PubMed1989

An epidemiologic and histopathological study of sudden cardiac death in Osaka Medical Examiner's Office.

From 1982 to 1986, 1230 sudden death cases were autopsied in Osaka Medical Examiner's Office. Among them, 810 cases were sudden cardiac deaths (SCD) including coronary heart disease (77%), cardiomyopathy (7%), valvular disease (3%). All SCD cases were dead within 24 hours of the appearance of the fatal symptoms, and most of them (72%) were considered instantaneous death. Many of the fatal symptoms began in bed (31%), at bath (17%), at toilet (8%), or at work (8%). Thirty-four percent of them were thought by themselves or by their families to be healthy before the death. Hypertension (38%), coronary heart disease (13%) and diabetes mellitus (11%) were the major past history recorded. Microscopic observation of the hearts of 200 cases autopsied in 1986 showed various cardiac lesions: hypertrophy, atrophy, degenerations of myocytes, cellular and fatty infiltrations of the interstitium. According to their cardiac lesions and degrees of severity of coronary sclerosis, patients who died suddenly were divided into 8 groups as follows: 1. myocardial infarction (41) 2. myocarditis (6) 3. hypertrophic cardiomyopathy (19) 4. chronic ischemia with severe coronary sclerosis (65) 5. chronic ischemia with moderate coronary sclerosis (27) 6. small vessel disease (18) 7. amyloidosis (1) 8. unknown (23). These results suggest that coronary heart disease and hypertension play an important role in SCD.

Adolescent↗