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Biomedical subjects

T Ohara

Publications and source records attributed to T Ohara.

At least 73 records · Page 4Linked to original sources
PubMed1999

[Intraoperative indirect monitoring of electrocardiogram].

The electrocardiogram (ECG) is used as a standard monitoring method during anesthesia and operation. But during the operation of severely burnt patients, the electrodes for ECG cannot be placed on the ideal points for the standard limb leads. We tried the indirect monitoring of the ECG. We placed the electrodes on the sheet over the operating table, and connected the patient and the electrodes with water. By this way the ECG similar to the standard limb leads could be recorded. This method is useful for the patients, with such diseases as severe burn, severe atopic dermatitis and epidermolysis bullosa hereditaria.

Electrocardiography↗
PubMed1999

A case of ABO-incompatible renal transplant patient with non-insulin-dependent diabetes mellitus; long-standing observation of serial glomerular change by protocol biopsy.

A 41-yr-old patient with non-insulin-dependent diabetes mellitus (NIDDM), before and after ABO-incompatible renal transplant, is reviewed using serial protocol biopsy. Although she recovered from delayed hyperacute rejection (DHAR) immediately post-transplantation, her graft function deteriorated gradually. A mild acute transplant glomerulitis, noted at the 155th day post-transplantation, progressed to pronounced chronic transplant glomerulopathy over 5 yr. In the specimen of the last biopsy, at 5 yr post-transplantation, glomeruli demonstrated an exudative hyaline lesion, which was characteristic of diabetic nephropathy in addition to chronic transplant glomerulopathy. Therefore, we made a diagnosis of this glomerular lesion as chronic transplant glomerulopathy complicated by diabetic glomerulopathy. Considering the result of this case, the protocol biopsy is a useful procedure to diagnose an accurate cause of graft dysfunction in individual cases. It is concluded that the protocol biopsy is apparently useful for the detection of various pathological processes occurring in allograft and may contribute to a strategy for improvement of graft survival.

ABO Blood-Group System↗
PubMed1998

Metabolic changes in hibernating myocardium after percutaneous transluminal coronary angioplasty and the relation between recovery in left ventricular function and free fatty acid metabolism.

To elucidate the changes in oxidative metabolism in hibernating myocardium after coronary revascularization, we performed myocardial single-photon emission computed tomography with a free fatty acid analog, I-123 beta-methyliodophenylpentadecanoic acid (BMIPP), and thallium-201 before and 1 month after percutaneous transluminal coronary angioplasty (PTCA) in 11 patients with angina pectoris caused by single artery stenosis. All patients had improvement in wall motion after PTCA at the region with coronary stenosis; the wall motion abnormality score evaluated by left ventriculography decreased from 5.5+/-0.8 (mean +/- SE) to 2.1+/-0.9, p <0.01) after PTCA. The defect score of I-123 BMIPP images was significantly larger than that of thallium-201 images either before (14+/-1.3 vs 8.9+/-1.1, p <0.01) or 1 month after (7.4+/-1.5 vs 3.7+/-0.8, p <0.01) PTCA. The decrease in the defect score of both images was significant (p <0.01). Changes in the wall motion abnormality score showed a significant correlation with both the change in the defect score of thallium-201 images (r = 0.58, p < 0.01) and that of I-123 BMIPP images (r = 0.75, p <0.01). These results indicate that the metabolism of free fatty acid is impaired in hibernating myocardium, and that improvement in left ventricular function after successful PTCA is strongly associated with the recovery of oxidative metabolism.

Adult↗
PubMed1998

DNA polymerase II (epsilon) of Saccharomyces cerevisiae dissociates from the DNA template by sensing single-stranded DNA.

Two forms of DNA polymerase II (epsilon) of Saccharomyces cerevisiae, Pol II* and Pol II, were purified to near homogeneity from yeast cells. Pol II* is a four-subunit complex containing a 256-kDa catalytic polypeptide, whereas Pol II consists solely of a 145-kDa polypeptide derived from the N-terminal half of the 256-kDa polypeptide of Pol II*. We show that Pol II* and Pol II are indistinguishable with respect to the processivity and rate of DNA-chain elongation. The equilibrium dissociation constants of the complexes of Pol II* and Pol II with the DNA template showed that the stability of these complexes is almost the same. However, when the rates of dissociation of the Pol II* and Pol II from the DNA template were measured using single-stranded DNA as a trap for the dissociated polymerase, Pol II* dissociated 75-fold faster than Pol II. Furthermore, the rate of dissociation of Pol II* from the DNA template became faster as the concentration of the single-stranded DNA was increased. These results indicate that the rapid dissociation of Pol II* from the DNA template is actively promoted by single-stranded DNA. The dissociation of Pol II from the DNA template was also shown to be promoted by single-stranded DNA, although at a much slower rate. These results suggest that the site for sensing single-stranded DNA resides within the 145-kDa N-terminal portion of the catalytic subunit and that the efficiency for sensing single-stranded DNA by this site is positively modulated by either the C-terminal half of the catalytic subunit and/or the other subunits.

Amino Acid Sequence↗
PubMed1998

The second subunit of DNA polymerase III (delta) is encoded by the HYS2 gene in Saccharomyces cerevisiae.

DNA polymerase III (delta) of Saccharomyces cerevisiae is purified as a complex of at least two polypeptides with molecular masses of 125 and 55 kDa as judged by SDS-PAGE. In this paper we determine partial amino acid sequences of the 125 and 55 kDa polypeptides and find that they match parts of the amino acid sequences predicted from the nucleotide sequence of the CDC2 and HYS2 genes respectively. We also show by Western blotting that Hys2 protein co-purifies with DNA polymerase III activity as well as Cdc2 polypeptide. The complex form of DNA polymerase III activity could not be detected in thermosensitive hys2 mutant cell extracts, although another form of DNA polymerase III was found. This form of DNA polymerase III, which could also be detected in wild-type extracts, was not associated with Hys2 protein and was not stimulated by addition of proliferating cell nuclear antigen (PCNA), replication factor A (RF-A) or replication factor C (RF-C). The temperature-sensitive growth phenotype of hys2-1 and hys2-2 mutations could be suppressed by the CDC2 gene on a multicopy plasmid. These data suggest that the 55 kDa polypeptide encoded by the HYS2 gene is one of the subunits of DNA polymerase III complex in S.cerevisiae and is required for highly processive DNA synthesis catalyzed by DNA polymerase III in the presence of PCNA, RF-A and RF-C.

Amino Acid Sequence↗
PubMed1998

Citrus viroid Ia is a derivative of citrus bent leaf viroid (CVd-Ib) by partial sequence duplications in the right terminal region.

Nucleotide sequences of group I citrus viroids Ia (CVd-Ia) and citrus bent leaf viroid (CBLVd, formerly designated CVd-Ib) isolated from citrus plants in Japan, the Philippines and China have been determined. Citrus samples in Japan and the Philippines contained CVd-Ia, which consists of 328 nucleotides(nt). Although 10 nt longer than the type CBLVd-225A in Israel they share 94% identity in overall nucleotide sequence. The Philippines sample also contained a 329-nt long CVd-Ia sequence variant, in which one base insertion and three substitutions were observed. A citrus in China contained CBLVd, which consists of 318 nt and shares 98% identity to CBLVd-225A. CVd-Ia was clearly separated from CBLVd by two 5-nt insertions located in upper (5'-AGCUG-3') and the lower (5'-CUUCU-3') strand of the right terminal region (which is also designated T2 domain) in rod-like secondary structure. Since both of the additional 5-nt sequences are similar to the adjacent sequences (5'-AGUUG-3' and 5'-CUUCU-3'), we hypothesize that CVd-Ia is a derivative of CBLVd caused by partial sequence duplications and substitutions taking place in the right terminal region.

Base Sequence↗
PubMed1998

Wavelet transform system makes one-beat analysis possible in late potential evaluation.

High-frequency components of the QRS complex, including late potentials, can be analyzed by signal averaging (SA). However, this method may fail to detect transient changes as a result of cancellation. The wavelet transform, which has a superior time-frequency resolution, was used to analyze beat-to-beat changes of the QRS components in 50 normal subjects and 50 patients who showed positive late potentials. The transformed data, displayed in three dimensions and in color, were highly reproducible in each patient. Measurement of high-power duration at a frequency of 50 Hz (WD50) showed a significant correlation between WD50 and filtered QRS duration in both groups. When the mean +/- SD of WD50 in normal subjects was defined as normal, 96% of patients with late potentials were out of the normal range. The wavelet signals in patients with late potentials were more inhomogeneous than those of normal subjects. It is concluded that this newly developed color display, three-dimensional wavelet transform system showed extremely good time-frequency resolution in analyzing every beat without signal averaging.

Action Potentials↗
PubMed1998

Nicking sites in a subunit of cholera toxin and Escherichia coli heat-labile enterotoxin for Vibrio cholerae hemagglutinin/protease.

We analyzed the nicking site of the A subunit of Escherichia coli heat-labile enterotoxin for hemagglutinin/protease produced by Vibrio cholerae non-O1 (NAG-HA/P). The determined nicking site was the Thr193-Ile194 junction, which was distinct from that for a protease of V. cholerae (Ichinose et al., European Journal of Epidemiology 8, 743-747, 1992). We further analyzed proteolytic cleavage by NAG-HA/P of a synthetic peptide corresponding to the nicking region of cholera toxin A subunit and determined the cleavage site to be preferentially between Ser194 and Met195, and in addition between Ser193 and Ser194.

Bacterial Toxins↗
PubMed1998

Ultrasound instruments as possible vectors of staphylococcal infection.

In this study, we evaluated whether ultrasound instruments are important in the spread of nosocomial staphylococcal infections. Following genomic typing by pulsed-field gel electrophoresis, it was apparent that ultrasound procedures transferred colonizing staphylococci from a patient's skin to the ultrasound instruments. Staphylococcus aureus survived in the transmission medium for longer than in water. Furthermore, S. aureus was more resistant to the ultrasonic medium than Pseudomonas aeruginosa, also a significant cause of hospital-acquired infections. To prevent staphylococcal transmission by ultrasound equipment, we recommend disinfection of the probe and removal of the medium after each examination.

Cross Infection↗
PubMed1998

Long-term follow-up of primary anterior chamber intraocular lens implantation.

PURPOSE: To evaluate the long-term outcome in eyes having primary anterior chamber intraocular lens (AC IOL) implantation. SETTING: Kimura Eye and Internal Medicine Hospital, Hiroshima, Japan. METHODS: Primary AC IOL implantation was performed in 171 eyes from 1983 to 1988. Two lenses were implanted: the open C-loop Simcoe lens and the 4-point fixation Kelman lens. In 86 eyes that had a mean follow-up of 9 years 7 months, visual acuity, corneal endothelial cell density, pupil shape, and the presence of associated complications were examined. RESULTS: Although the final visual acuity was 0.5 or better in 60 eyes (69%), corneal endothelial cell density was less than 2000 cells/mm2 in 46 eyes (57%). Postoperative complications included a deformed pupil in 48 eyes (56%) and bullous keratopathy in 12 eyes (14%). In 14 eyes the AC IOL was explanted; 11 of these were the open C-loop Simcoe lens. CONCLUSION: Although our findings show that the open C-loop AC IOL (Simcoe) is contraindicated, implantation of the 4-point fixation AC IOL may be acceptable in selected cases.

Aged↗
PubMed1998

DNA polymerase epsilon encoded by cdc20+ is required for chromosomal DNA replication in the fission yeast Schizosaccharomyces pombe.

BACKGROUND: DNA polymerase II (PolII), the homologue of mammalian DNA polymerase epsilon, is essential for chromosomal DNA replication in the budding yeast Saccharomyces cerevisiae and also participates in S-phase checkpoint control. An important issue is whether chromosomal DNA replication in other eukaryotes, including the fission yeast Schizosaccharomyces pombe--in which the characteristics of replication origins are poorly defined--also requires DNA polymerase epsilon. It has been shown that DNA polymerase epsilon is not required for the in vitro replication of SV40 DNA by human cell extracts. RESULTS: We have cloned and sequenced S. pombe pol2+, which is identical to the cell-cycle gene cdc20+, encoding the catalytic polypeptide of DNA polymerase epsilon (Pol epsilon). The predicted amino acid sequence of Pol epsilon is highly homologous to that of S. cerevisiae PolII and human Pol epsilon. Consistent with this, the Pol epsilon polypeptide was recognized by polyclonal antibodies against S. cerevisiae PolII holoenzyme (PolII*). The terminal morphology of cells containing the disrupted pol2 gene was similar to that of DNA replication mutant cells and cdc20 mutant cells. Furthermore, the Pol epsilon activity from temperature-sensitive S. pombe cdc20 mutant cells was temperature-sensitive, and chromosomal DNA replication in the mutant cells was inhibited at the restrictive temperatures. CONCLUSION: These data strongly suggest that Pol epsilon is required for normal chromosomal DNA replication in S. pombe, as is PolII in S. cerevisiae. Thus, eukaryotic chromosomal DNA is replicated differently from that of viral SV40 DNA.

Amino Acid Sequence↗
PubMed1998

Renal ACE immunohistochemical localization in NIDDM patients with nephropathy.

A role of renal angiotensin-converting enzyme (ACE) in diabetic nephropathy has been suggested. Immunohistochemical localization of ACE was studied in 20 non-insulin-dependent diabetes mellitus patients with diabetic nephropathy and 17 healthy kidney transplant donors, with ACE gene insertion/deletion (I/D) polymorphism also examined in the latter. Immunohistochemical studies indicated that ACE staining was significantly (P < 0.01) enhanced in glomeruli and slightly decreased in proximal tubules in diabetic patients. Glomeruli positive for ACE immunostaining were observed in 23.5% of the healthy subjects and in 80% of the diabetic patients. All patients with nodular lesions had ACE-positive glomeruli and showed significantly (P < 0.01) more intense glomerular ACE immunostaining than patients without nodular lesions. Among healthy controls, subjects with the DD genotype had ACE-positive glomeruli more frequently and tended to show slightly increased intensity on proximal tubule ACE immunostaining compared with subjects with other genotypes. These observations suggest that increased ACE localization in glomeruli is likely to be one of the factors in the increased renin-angiotensin system activity in glomeruli in patients with diabetic nephropathy. There is a possibility that ACE gene I/D polymorphism may be related to renal ACE immunohistochemical localization.

Diabetes Mellitus, Type 2↗
PubMed1998

Epidemiologic typing of methicillin-resistant Staphylococcus aureus in neonate intensive care units using pulsed-field gel electrophoresis.

To elucidate the mode of dissemination of methicillin-resistant Staphylococcus aureus (MRSA) in neonate intensive care units (NICUs), a total of 223 isolates from 3 separate hospitals were investigated between 1994 and 1996 by a DNA fingerprinting technique with pulsed-field gel electrophoresis (PFGE). Exoprotein profiles of some strains were also examined using SDS-polyacrylamide gel-electrophoresis (SDS-PAGE) and the assessment of enzyme/toxin production such as coagulase, enterotoxin and TSST-1. Judging from the strain typing data from PFGE results and the epidemiological data, 2 different types of PFGE patterns (A and B) and their subtypes (A', A'' and B') were identified. The A type including A' and A'' (comprising approximately 95% of the isolates) was markedly dominant. Only 5% of the isolates belonged to type B and subtype B'. On the other hand, MRSA isolated from adult patients admitted to the same hospital showed many different PFGE patterns. The results strongly suggested that some strain(s) with specific PFGE pattern(s) is prevalent in NICUs. Furthermore, isolates which expressed the same PFGE pattern did not always express the same SDS-PAGE pattern. There were some isolates with different abilities to produce coagulase, enterotoxin C and toxic-shock syndrome toxin (TSST)-1, and the abilities had no relation with a particular type of PFGE pattern. Therefore, a combination of PFGE analysis and biochemical analyses of coagulase, enterotoxin C and TSST-1 may provide us with more detailed information for the epidemiological study of MRSA in NICUs.

Adult↗
PubMed1998

Mechanism of impaired left ventricular wall motion in the diabetic heart without coronary artery disease.

OBJECTIVE: To elucidate whether impairment of the myocardial free fatty acid (FFA) metabolism and small vessel abnormalities in the myocardium are etiologic or contributory factors of myocardial dysfunction in patients with NIDDM without any significant coronary artery disease. RESEARCH DESIGN AND METHODS: We performed myocardial imaging with 123I-labeled beta-methyl-p-iodophenyl pentadecanoic acid (BMIPP), a branched analog of FFA, and dipyridamole-infusion 201thallium scintigraphy (Dip) in nine patients who demonstrated left ventricular wall motion abnormalities without any significant coronary artery disease and in fifteen control cases. As an index of myocardial FFA metabolism, the heart-to-mediastinum count ratio (H/M) of BMIPP was calculated from the mean count in the regions of interest at the heart and the upper mediastinum. RESULTS: Nine patients with reduced wall motion documented by left ventriculography (LVG), (hypokinetic group) demonstrated significantly lower BMIPP uptake (2.1 +/- 0.2, mean +/- SD) than fifteen patients with normal wall motion (normokinetic group) (2.3 +/- 0.2, P < 0.05). Regional ventricular wall motion observed by LVG, regional BMIPP uptake, and regional redistribution phenomenon (RD) were evaluated for five regions of the left ventricle: anterior, septal, apical, lateral, and inferoposterior regions. Wall motion was abnormal in 24 out of 120 regions. Regional BMIPP uptake was reduced in 47 regions. RD in Dip was observed in 23 regions. In regional analysis, the existence of defect in the BMIPP image showed significant correlation with wall motion abnormality (P < 0.01), but there was no significant relationship between the RD in Dip and regional wall motion abnormality (P = 0.16). Myocardial biopsy specimens obtained from the right ventricle of 20 patients showed no pathologic changes, with the exception of two patients. CONCLUSIONS: Our findings suggest that impairment of myocardial FFA metabolism rather than small vessel abnormalities in the myocardium is responsible for modest left ventricular dysfunction in patients with diabetes.

Adult↗
PubMed1998

[The influence of the physician's speciality on ambulatory "essential laboratory tests"].

The purpose of this study was to examine the influence of a physician's speciality on the choice of "essential laboratory tests" and their response to the test results. A retrospective case-control study was conducted in divisions of the Department of Internal Medicine in Jichi Medical School Hospital. Twenty-seven parameters were evaluated in 213 outpatients (mean age 47 +/- 17 years; 53% female). Forty-three percent (2443 of 5751) of the tests were conducted by the physician under study and 10.5% (257 of 2443) of their tests were abnormal. The physician's speciality influenced the choice of the ambulatory medical examinations and their response to abnormal tests. Physicians tend to be more sensitive to the abnormality of tests related to their specialty. Hence, it is necessary to constitute guidelines on the response to abnormal "essential laboratory tests".

Adolescent↗