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Biomedical subjects

S Ohtani

Publications and source records attributed to S Ohtani.

At least 37 records · Page 2Linked to original sources
PubMed2000

[Development of gamma-heavy chain disease during the course of diabetic nephropathy].

We reported a rare case of gamma-heavy chain disease. A 63-year-old man had been given a diagnosis of diabetes mellitus at the age of 30 and had received hemodialysis since the age of 55. The patient presented with swollen lymph nodes in the neck. Lymph node biopsy findings suggested immunoblastic lymphadenopathy. The patient was admitted to Kitasato University hospital. Serum protein electrophoresis showed an increase of beta-fraction peak, and immunoelectrophoresis revealed an increase of gamma-heavy chain protein. Further studies of the gamma-heavy chain protein showed that it contained three different components and that the molecular weight of the main component was 34,000 Da. The patient died on the 11th day of hospitalization. The diagnosis at autopsy was unclassified malignant lymphoma.

Diabetic Nephropathies↗
PubMed2000

[Combined valvular and coronary artery surgery].

Between 1990 and 1999, 78 patients underwent combined valvular coronary artery operation. Aortic valve disease was present in 49 patients, mitral valve disease in 23 patients, aortic and mitral valve disease in 6 patients. The average age was 67 years. Twelve patients had had a previous myocardial infarction. The average number of grafts inserted was 1.82 per patients, and the average number of artery grafts inserted was 0.96 per patients. The most number of grafts were placed prior to valve replacement or plasty. And periods of myocardial ischemia were kept at a minimum by coronary perfusion through free grafts. Preoperative mortality was 1.3%. And event fee ratio after operation was 95% (mean follow up 42 month). Therefore the operative risk of combined surgery is, in general, low and the long term results are favorable.

Aged↗
PubMed2000

[A case report of aneurysm of the ductus arteriosus combined with mitral regurgitation].

A case with the giant aneurysm of the ductus arteriosus combined with severe mitral regurgitation is reported. 58-year-old male underwent MVR and patch closure of the ductal orifice for staged operation. The first operation was MVR and patch closure of the PDA orifice of the pulmonary artery end using retrograde cerebral perfusion (RCP) with deep hypothermic circulatory arrest (DHC). The second operation was performed on 3 months after the first operation using left thoracotomy approach, and patch closure of the ductal orifice via the aorta using RCP with DHC was performed. Upon following-up examination, the patient is now doing well 20 months after the initial surgery.

Cerebrovascular Circulation↗
PubMed2000

[Responses in a questionnaire by medical school students who participated in the new curriculum of the clinical learning in clinical pathology].

The clinical learning taken by medical students are an important part of their medical education. To develop a new, effective curriculum for the clinical learning in Clinical Pathology, the instructors defined clear general instructional objectives and specific behavioral objectives, and discussed the learning strategies and evaluation methods. The medical students at our medical school took this new curriculum in Clinical Pathology in 1999. As an evaluation method of this new curriculum, we asked all students to fill out a questionnaire that asked their opinions about the length of each component in the Clinical Pathology rotation, the content of the rotation, etc. Over 80% of the respondents answered that the rotation in Clinical Pathology was useful. Ninety-six percent of the students felt that the experience and knowledge they gained in this Clinical Pathology rotation will be useful in the clinical learning in other departments. Based on the high percentage of favorable responses from the students, we concluded that the new curriculum, which was developed after intensive planning, was successful. In summary, the feedback from students who took the new curriculum in Clinical Pathology showed that this new course was well-accepted by the students and that it created an excellent relationship between the instructors and students. Some of the responses in the questionnaires will be used to improve the Clinical Pathology rotation in the future.

Consumer Behavior↗
PubMed2000

[Estimation of age from teeth using the racemization of aspartic acid (racemization method)].

We report a method for estimation of age from teeth using the racemization of amino acids (racemization method). This method is based on the characteristics of the constant age-related increase in the amount of D-aspartic acid in dentin. We estimated age by measuring the ratio of D-aspartic acid to L-aspartic acid, i.e. the ratio of racemization ¿ratio of D/L, ln[(1 + D/L)/(1 - D/L)]¿. Because different D/L ratios have been obtained from different teeth in the same individuals and from different sites of dentin in the same tooth, we usually prepare bucco-lingual longitudinal sections at the central part of each tooth, and prepare samples of powdered whole dentin. This powder is then mixed and used to measure the D/L ratio in the dentin. To accurately estimate age from forensic specimens, we simultaneously measured the D/L ratios in more than four control teeth of the same type obtained from subjects of known age. Use of control teeth is necessary because it is sometimes difficult to maintain constant running conditions for gas chromatography to obtain reproducible values in different runs. Therefore, for every measurement, we determined an equation for calculating age from the D/L ratios of control teeth, and estimated the age of the specimen tooth by substituting in its D/L ratio. The most reliable results were obtained using samples of lower incisors or premolars, which are single-rooted teeth with a relatively small volume of dentin. Thus sampling of the dentin is easier than for other teeth. It is better to keep control teeth desiccated because racemization does not proceed readily under such conditions. The deviation from the actual age in the cases we examined was less than 3 years. Thus, racemization of amino acids can be used for accurate estimation of age from teeth.

Adolescent↗
PubMed1999

[New screening method for coagulation abnormality including AT III deficiency during CABG].

In our institute, 1 ml of heparin is administered to the patients undergoing CABG before dissection and mobilization of the internal thoracic arteries (ITAs) and/or right gastroepiploic artery (GEA) to prevent possible thrombosis or coagulation tendency. Two patients with AT III deficiency underwent CABG and one of them died. The aim of this study is to know whether ACT check before and after administration of 1 ml of heparin is useful as a screening test of coagulation abnormalities including AT III deficiency. One hundred patients (84 males and 16 females) undergoing CABG were studied. Age ranged from 41 to 79 years (mean 64.8 +/- 8.0 years). One ml of heparin was administered to all the patients before ITAs and/or GEA were dissected and mobilized. ACT was doubly checked before (control ACT: c-ACT) and after (heparinized ACT: h-ACT) administration of heparin. ACT extension was defined as follows: ACT extension = (c-ACT)-(h-ACT). Mean c-ACT was 124 +/- 12 sec., h-ACT 188 +/- 26 sec. and ACT extension 64 +/- 24 sec. There were only 3 cases which ACT extension were less than 30 sec.: two of them were combined with AT III deficiency and the other was due to insufficient administration of heparin. In conclusion, examination of ACT after 1 ml administration of heparin is new, simple and convenient screening method for coagulation abnormalities including AT III deficiency during CABG.

Adult↗
PubMed1999

[Clinical study of emergency coronary artery bypass surgery].

Between January, 1996 and December, 1998, 29 patients were undergone emergency coronary artery bypass grafting (CABG) in our institute. Age ranged 34 to 85 years (mean 65 +/- 11 years, male:female = 25:4). Of 29 emergency cases, 3 were hospital death. Hospital mortality rate was 10.7%, which was significantly higher than the hospital mortality of elective CABG (1.4%) during the same period. The necessity of IABP before CABG was 72% in emergency cases (elective surgery: 0%). Thus the use rate of arterial grafts were 86.2% in emergency cases (elective surgery: 100%), the patency of the arterial grafts were 100%. It is important to make stable condition of the patients before the operation, and therefore it is important to make contact closely with the cardiologists for making stable condition and for lowering the operative mortality. And, we should use arterial grafts for the long term result as much as possible if it is an urgent operation.

Adult↗
PubMed1998

Expression and distribution of brain natriuretic peptide in human right atria.

OBJECTIVES: We investigated expression of brain natriuretic peptide (BNP) as well as atrial natriuretic peptide (ANP) and their genes in human right atria. Their relations with atrial pressure were also examined. BACKGROUND: The BNP plays a roll in electrolyte-fluid homeostasis such as ANP. The tissue level is reported to be elevated in the failing ventricles. However, expression and transmural distribution of BNP in the atria remain unclear. METHODS: Expression of ANP and BNP was immunohistochemically investigated in the right atrial (RA) specimens from 21 patients who had undergone cardiac surgery. The mRNA of specimens were quantitatively measured by Northern blot analysis and also evaluated by in situ hybridization. In addition, plasma levels of ANP and BNP were measured in the patients. RESULTS: The BNP immunoreactivity was diffusely seen in RA tissue of patients with mean RA pressure (mRAP) of 5 mm Hg or more, but it was noted only in the subendocardial half of the atria of those with mRAP less than 5 mm Hg. There was a significant correlation between the incidence of BNP-positive myocytes and mRAP (r = 0.850, p < 0.0001). Conversely, ANP-positive myocytes were found diffusely in all cases. In Northern blot analysis, the mRNAs levels of ANP and BNP in the atrial tissue were positively correlated with the mRAP (ANP, p = 0.775, p < 0.005 and BNP, p = 0.771, p < 0.005). In situ hybridization confirmed these findings. The mRNA levels were significantly correlated to each other (r = 0.845, p < 0.0002). Plasma ANP and BNP levels were elevated in the patients compared with that in controls; however, none were significantly correlated with the mRAP. CONCLUSIONS: Expression of BNP and BNP mRNA is augmented in the atria with increased pressure, and distributed predominantly in the subendocardial side. The level of BNP mRNA was well correlated with that of ANP mRNA. Thus, these two genes might be commonly regulated in response to atrial pressure.

Aged↗
PubMed1998

Purification and characterization of myonase from X-chromosome linked muscular dystrophic mouse skeletal muscle.

A chymotrypsin-like proteinase, designated myonase, was successfully purified to homogeneity from X-chromosome linked muscular dystrophic mouse skeletal muscle by affinity chromatography on agarose conjugated with lima bean trypsin inhibitor as ligand. The molecular mass of the purified myonase was determined to be 26 kDa by SDS-PAGE and to be 25,187 Da by mass spectrometry. The native enzyme is a single chain molecule and a monomeric protein without sugar side-chains. The nucleotide sequence of myonase mRNA is similar to mouse mast cell proteinase 4 (MMCP-4) cDNA. This is the first report of a native enzyme whose amino acid sequence closely corresponds to MMCP-4 cDNA. Myonase has chymotrypsin-like activities and hydrolyzes the amide bonds of synthetic substrates having Tyr and Phe residues at the P1 position. Myonase is most active at pH 9 and at high concentration of salts. Myonase preferentially hydrolyzes the Tyr4-Ile5 bond of angiotensin I and the Phe20-Ala21 bond of amyloid beta-protein, and it is less active towards the Phe8-His9 bond of angiotensin I and the Phe4-Ala5 and Tyr10-Glu11 bonds of amyloid beta-protein. Myonase is completely inhibited by such serine proteinase inhibitors as chymostatin, diisopropylfluorophosphate and phenylmethylsulfonyl fluoride, but not by p-tosyl-L-phenylalanine chloromethyl ketone, p-tosyl-L-lysine chloromethyl ketone, pepstatin, E-64, EDTA, and o-phenanthroline. It is also inhibited by lima bean trypsin inhibitor, soy bean trypsin inhibitor, and human plasma alpha1-antichymotrysin. These properties match those of chymase, but unlike chymase, myonase does not interact with heparin in the regulation of its activity. Myonase was immunohistochemically localized in myocytes, but not in mast cells.

Amino Acid Sequence↗
PubMed1998

Improvement of age estimation using amino acid racemization in a case of pink teeth.

Age was estimated from pink teeth using racemization of dentinal aspartic acid. Materials for identification were two lower second premolars. The body was determined to be that of a 40-year-old man; however, the age of the decedent had been estimated to be 29 and 30 years by the conventional method and 30 years from findings in the oral cavity. To clarify the cause of this difference, the powdered teeth were further washed in 0.01 mol/L hydrochloric acid. The racemization ratio (D/L ratio) of ordinary white teeth from persons of known age was slightly lower than that before washing, whereas that of the teeth used for identification was higher than before washing. The calculated age of the decedent using the racemization ratio of his teeth was between 36 and 37 years. These results suggest that age estimated from pink teeth is probably underestimated, but a more accurate age estimate can be obtained after adequate washing.

Adult↗
PubMed1998

Rate of aspartic acid racemization in bone.

There are no reports on rates of amino acid racemization in bones. To investigate the possibility of estimating age by evaluating amino acid residue racemization in human bones, a heating experiment was performed and the rate of aspartic acid racemization was determined using the Arrhenius equation. Assuming an annual mean temperature of 15 degrees C, the rate constant (k) for aspartic acid racemization in bone was calculated, and the racemization rate at 15 degrees C k (y) was 4.1036 x 10(-9)--much lower than that of dentin. These results suggest that it is more difficult to accurately determine age by analyzing aspartic acid residues in bone than in dentin.

Adult↗
PubMed1998

Localization of pNT22 70 kDa heat shock cognate-like protein in the plasma membrane.

It has been argued that 70 kDa heat shock cognate (hsc73)-like molecules may be expressed on the surface of certain cells, but direct evidence of this has yet to be found. To clarify whether this molecule belongs to hsc73 itself, the membrane protein fraction of Daudi cells was isolated by Triton X-114 phase separation and the reactivity of this membrane protein fraction was assessed with monoclonal antibodies (mAbs) which react with 70 kDa heat shock protein (hsp) family, i.e., NT22, A15 and 3A3. In western blotting analysis, mAb NT22-defined protein (pNT22) was clearly detected as a membrane protein of Daudi cells with an approximate molecular size of 70 kDa, whereas pNT22 was not recognized by anti-cytoplasmic hsc73/hsp72 mAbs A15 or 3A3. By using deleted recombinant hsc73 proteins, it was determined that mAb NT22 recognizes the N-terminal 350-372 amino acid stretches of the hsc73 protein. mAb NT22 also reacted with the cell surface protein of Daudi cells in FACS analysis. Taken together, our present data strongly suggest that pNT22 may be a novel hsc73-like protein that is localized in the plasma membrane.

Antibodies, Monoclonal↗
PubMed1998

Expression of heat shock protein after ischemic preconditioning in rabbit hearts.

Previous studies have shown that preconditioning (PC) with a brief ischemic episode induces heat shock protein (HSP) in cardiac tissue. However, it is unclear when and where in the left ventricle HSP is expressed after PC. Hence, the expression of HSP was studied in rabbit hearts at various time intervals after PC using immunohistochemical methods. Rabbits were preconditioned four times with 5 min of occlusion and 5 min of reperfusion of the coronary artery and then were killed at 0, 3, 24, 48, 72 and 168 h after the PC (n=4, for each time interval). Samples were obtained from the subendocardium and subepicardium of the preconditioned and nonpreconditioned wall and these were processed to 4 microm thick cryosections. The sections were immunolabelled with mouse monoclonal IgGs against HSP 72/73. Positive immunoreactivity was observed as early as 3 h after PC, persisting up to 72 h but not detected at 168 h. HSP was expressed not only in the preconditioned myocardium but also in the remote nonpreconditioned myocardium. There was a wide variation in expression among myocytes. Expression was dominant in myocytes compared with vessel walls. It was concluded that PC induced transient and inhomogeneous expression of HSP in rabbit hearts.

Animals↗
PubMed1998

Changes in the amount of D-aspartic acid in the human femur with age.

The amount of D-aspartic acid (D/L ratio) among total amino acids, acid-insoluble collagen, and non-collagen proteins (acid-soluble peptides) from the human femoral compact substance was measured by gas chromatography. We found that the amount of D-aspartic acid increased linearly with age in males but not in females. This difference between the sexes may be related to the sex differences in hormonal circumstances to the fact that osteopathy is more common in females than in males. The D/L ratio in total amino acids varied with the size of the bone fractions, being higher in large ones. The D/L ratio in acid-soluble peptides varied with the size of the powder particles from which they had been extracted, and was also higher in large particles. It is concluded that D-aspartic acid in the femoral compact substance increases with age only in males.

Adolescent↗
PubMed1998

Evaluation of aspartic acid racemization ratios in the human femur for age estimation.

Levels of D-aspartic acid (D/L ratio) in cranial non-collagen proteins (acid-soluble peptide fractions) have been reported to increase with age. We isolated total amino acid fractions from the femur and separately isolated acid-insoluble collagen fraction and acid-soluble peptide fractions; then D/L ratios were measured from each fraction by gas chromatography. We evaluated the applicability of their D/L ratios for age estimation based on their correlation coefficient. A sex-related difference was observed in the D/L ratio. In particular, aged females showed a low ratio, suggesting an association with bone disorders. In males, the D/L ratios of acid-soluble peptide fraction showed the highest correlation rate (r = 0.969) with age, and those of total amino acid fraction showed the highest correlation rate (r = 0.633) with age in females. Without separation of male and female, the D/L ratios of total amino acid fraction showed the highest value (r = 0.853). The D/L ratio of acid-soluble peptide fractions differed according to the size of bone powder particles, being higher for larger particle sizes. These results suggest that the application of D/L ratio from total amino acid fraction is the most effective method for estimating age using the human femur. However, care is necessary when studing cadavers that might be females.

Adolescent↗
PubMed1997

The Relation between Superoxide Dismutase in Cancer Tissue and Clinico-pathological Features in Breast Cancer.

The localization of Cu/Zn- and Mn-superoxide dismutase (SOD) in breast cancer tissue (12 papillotubular carcinomas, 21 solid-tubular carcinomas, 16 scirrhous carcinomas, 1 medullary carcinoma, 1 secreting carcinoma, 1 lobular carcinoma, 1 Paget's disease) was investigated via an immunohistochemical technique using antihuman Cu/Zn- and Mn-SOD antibodies in 10%formalin fixed-paraffin embedded thin sections. Both SODs stained strongly in the normal breast gland, but not clearly in many cancer tissues. Furthermore, Cu/Zn-SOD stained more strongly in well differentiated tubular carcinomas than in poorly differentiated tubular carcinomas. It tended to stain less in tumors which recurred or had a poor outcome, and in tumors with a diploid pattern on DNA flow cytometry. Mn-SOD staining was similar to that of Cu/Zn-SOD, but no significant differences among subgroups was found, since the incidence of positively staining tumors was too small in all groups. The intensity of SOD staining seems to change in relation to cell proliferation and differentiation in breast carcinoma, and may be a prognostic indicator, since SOD decreased in poorly differentiated carcinoma and in tumors which developed distant metastasis. Thus, the localization of SOD in breast cancer tissue can provide useful information for cancer treatment.

Journal Article↗
PubMed1997

Expression of ubiquitin protein in each organ at death from hypothermia.

To examine the expression of heat shock protein (hsp) in each organ on autopsy in 11 deaths from hypothermia, we performed immunological staining of specimens from each organ using an antibody to hsp, ubiquitin (Ub). Staining of the liver, kidneys, lungs and pancreas revealed a high level of Ub expression in the cytoplasm and nuclei. However, staining of the same specimens of all controls revealed no Ub expression in the cytoplasm or nuclei. This finding suggests that cells are affected by stress even at a low temperature, and may be important in clarifying the cellular kinetics in death from hypothermia.

Adult↗