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Biomedical subjects

S Nakata

Publications and source records attributed to S Nakata.

At least 199 records · Page 11Linked to original sources
PubMed1993

Cytotoxic activity of spleen-derived T lymphocytes against autologous biliary epithelial cells in autopsy patients with primary biliary cirrhosis.

Autoimmunity against biliary epithelial cells is considered to be involved in the pathogenesis of primary biliary cirrhosis (PBC). However, cytotoxic activity of T lymphocytes against biliary epithelial cells has not previously been examined. This study has demonstrated that spleen-derived T lymphocytes were cytotoxic for autologous biliary epithelial cells in all of five patients with PBC, even though it was only detectable at high effector to target ratios. Such cytotoxicity was not found in non-PBC patients. CD8-positive T lymphocytes were shown to be responsible for the cytotoxicity by negative selection, and its inhibition was dependent on the ratio of cold to hot target cells. These observations may support a current hypothesis that the pathogenesis of PBC is partly due to T cell autoimmunity directed against the bile duct epithelium.

Aged↗
PubMed1993

Mass screening for prostate cancer and the bias relating to survival rate.

Since 1981 we have been studying prostate cancer (Pca) by mass screening (MS) in the Gunma Prefecture, Japan. From 1981 to 1990, 9,067 subjects (total 15,451) were examined in connection with this project and 121 subjects were diagnosed as having Pca. The presence of Pca in 87 cases was confirmed at their initial MS (initial group); 34 cases were confirmed either the year after or several years after the first MS (repeat group). To evaluate the significance of MS for Pca, in this group of patients, the effects of 'lead time bias', 'self-selection bias' and 'length bias' on the survival rate were compared to Pca patients detected in the hospitals of the Gunma Prefecture during the same period. The survival curves of MS cases for each stage of the disease were better than those of the controls. Only in stage D was there a significant difference between the two groups. However, this MS curve decreased from the 4th year in the same manner as the control curve from the start. The clinical characteristics (age, pathological differentiation, prostatic acid phosphatase, gait disturbance, erythrocyte sedimentation rate, chronic disease, and pain in the patients with stage D disease) were compared between both groups. All characteristics studied, except age, in the MS group were clinically more favorable compared to those of the controls for each stage or in total. Moreover, the relative survival rate of subjects examined by MS was greater than 1.0. No significant difference was found in stage distribution between the initial group and the repeat group.(ABSTRACT TRUNCATED AT 250 WORDS)

Acid Phosphatase↗
PubMed1993

[Evoked otoacoustic emissions: a comparison between responses from humans and guinea pigs].

Transiently evoked otoacoustic emissions (TEOAEs) from 16 normal human ears and 26 normal guinea pig ears were measured with the ILO 88 (ver 3.91). The following results were obtained: 1) In one animal ear, waveforms of TEOAEs were unchanged after administration of muscle relaxants, and showed reversible changes before and after asphyxia. 2) In 3 guinea pig and 2 human ears, the input-output functions showed a strong saturation at higher stimulus levels, when measurement of the highest peak-to-peak amplitude was used as the output energy. 3) Highest peak frequencies (HPFs) of TEOAEs were distributed at around 1 kHz in human ears but were concentrated around frequencies of 2 kHz to 3 kHz in almost all guinea pig ears. 4) Latencies of predominant TEOAEs in human and guinea pig ears were 9.26 +/- 1.89 msec and 2.37 +/- 0.47 msec, respectively. Endpoint times of TEOAEs were 16.37 +/- 1.79 msec and 5.74 +/- 1.10 msec, respectively. Both indicators in human ears were 3-4 times longer than those in guinea pig ears. From these results, we conclude that click-evoked TEOAEs can be detected even in guinea pigs. In addition, our measurements showed that HPFs of TEOAEs in guinea pig ears were higher than those in human ears, and that latencies and durations in guinea pig ears were much shorter than those in human ears. The higher HPFs of TEOAEs in guinea pig ears may be attributable to higher resonant frequencies in the middle ear than are found in human ears.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1993

[The clinical significance of carbohydrate antigen 19-9 (CA19-9) in transitional cell cancer of urinary tract].

For the purpose of evaluating the utility of CA19-9 determination in transitional cell cancer (TCC) of the urinary tract, its serum value, tissue level and, immunohistochemical study, and follow up study, with high serum value were examined in 43 cases with TCC and 13 cases of control. 1. Serum values were 19.1 U/ml in the control group and 198 U/ml in the tumor group. Though those of tumor were higher than those of the control group, there is no statistical difference between both groups. The cases with abnormally high value were observed in 13.7% of the control group, 13.8% of the bladder cancer, and 57.1% of the upper urinary tract cancer. 2. Tissue levels were 816 U/g wet tissue in the control group and 13,000 U/g wet tissue in the tumor group, showing a significantly higher value (p < 0.01) in the tumor group, statistically. 3. Immunohistochemical study were positive in 4.0% of the control group and 88.4% of the tumor group. 4. There is a significant correlation between serum values and tissue levels (p < 0.05, r = 0.483). 5. The serum values did not correlated with the staining property, tumor size, grade, and stage. 6. The tissue levels correlated with the tumor size, but did not correlate with the staining property, grade, and stage. 7. In the follow-up study of cases with high value, those, who had not attained postoperative normalization, died of recurrent carcinoma. In cases showing an elevation despite postoperative normalization, too, all showed recurrence. Only those, whose value were normalized and remained at the normal range, are living without metastasis.(ABSTRACT TRUNCATED AT 250 WORDS)

Antigens, Tumor-Associated, Carbohydrate↗
PubMed1993

[Study of risk factors for prostatic cancer].

A case-control study was conducted on 294 prostatic cancer patients and controls. General population controls were chosen from 13 areas in Gunma Prefecture and were matched by age (+/- 2 y.o.) to cases. Odds ratio (O.R.) and 95% confidence interval (C.I.) were calculated on each item according to group; 69 years old or younger and 70 years old or older, and age-adjusted O.R. and 95% C.I. were calculated. Risk factors of prostatic cancer were investigated. There was a significantly higher risk for prostatic cancer in those 1) engaged in agriculture, forestry or fishery (< or = 69, > or = 70, total), 2) shaving 1/3 days or less frequently (> or = 70, total), 3) having thin pubic hair (total), 4) phimosis (< or = 69, total), 5) having history of smoking (> or = 70, total), 6) history of smoking 50 years or more (total), 7) having eaten vegetables rarely (> or = 70, total), 8) having past history or complication of asthma (> or = 70). O.R.s of having past history or complication of benign prostatic hypertrophy, prostatitis and urethral stricture were high significantly, but they were supposed to be caused by bias. Four patients had first degree family members who suffered from prostatic cancer, compared to zero in the control. There was a significantly lower risk for prostatic cancer in those 1) engaged in office work (> or = 70, total), 2) blood type A or AB (< or = 69), 3) having had one child or none (total), 4) having past history or complication of tuberculosis (total).(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1993

Long-term performance of beta-propiolactone-treated nonviable homograft for aortic valve replacement and right ventricular outflow tract reconstruction.

The long-term performance of beta-propiolactone-treated homografts was clearly different between operative survivors of aortic valve replacement (n = 27) and those of right ventricular outflow tract reconstruction (n = 11). The reoperation-free survival rate at 20 years was 14.8 +/- 6.8 (standard error)% in the former and 77.8 +/- 13.9% in the latter. Even a nonviable aortic homograft can be favorably accepted as a material for right ventricular outflow tract reconstruction in contrast to the aortic position.

Adult↗
PubMed1992

Cardiac function and myocardial performance of 24-hour-preserved asphyxiated canine hearts.

A method of 24-hour storage of asphyxiated canine hearts for orthotopic cardiac transplantation was studied to expand the geographical size of the donor pool. Left ventricular function of asphyxiated hearts preserved for 24 hours (group 1, n = 8) was compared with that of hearts donated on-site (group 2, n = 5). Group 1 donors were pretreated with verapamil hydrochloride, propranolol hydrochloride, and prostacyclin. The donor hearts were perfused with warm blood cardioplegia in situ after 10 minutes of asphyxiation and then perfused with cold crystalloid cardioplegia for 2 hours. The hearts were excised and stored in ice-cold University of Wisconsin solution for 22 hours. At orthotopic transplantation, coronary perfusion with warm blood cardioplegia was performed before the graft aorta was unclamped. Conventional cardiac variables (eg, cardiac output and maximum rate of rise of left ventricular pressure), myocardial performance, and diastolic compliance of grafted hearts were assessed 1 hour after weaning from bypass. All recipients in both groups were easily weaned from cardiopulmonary bypass without inotropic agents, and there were no significant differences in cardiac variables between the two groups. These results strongly suggest that cadaver hearts can be preserved for 24 hours with satisfactory cardiac function.

Animals↗
PubMed1992

Voltage-dependent capacitance as a probe for albumin adsorption onto a solid surface.

The process of adsorption of bovine serum albumin onto a platinum electrode was monitored through the measurement of a nonlinear electrochemical property. The principle of the new method is that a sinusoidal voltage source is applied to a test solution and the waveform of the output current is analyzed by Fourier transformation. It was found that the intensities of the higher harmonics in the Fourier transformation change depending on the concentration of albumin and with time. From the higher harmonics, voltage dependence of the capacitance was quantitatively evaluated. The change of the state of albumin adsorbed onto the platinum plate was also monitored from the pattern of 'crack' of adsorbed albumin by using scanning electron microscopy. These results were discussed in relation to the mechanism of bimodal adsorption of albumin.

Journal Article↗
PubMed1992

Long-term occlusal guidance of a severely intoxicated patient with yusho (PCB poisoning): a case report.

The peculiar dentoorofacial characteristics and 12 years of interdisciplinary management of a patient who was severely intoxicated with the man-made chemical polychlorinated biphenyls (PCBs) are described in this case report. Cephalometric measurements showed that the SNA and SNB angles were reduced but that the developments in height and skeletal maturity were in normal ranges. Gingival hyperpigmentation that was caused by high blood PCB concentration was extremely slow to fade. A cystic mass, diffused trabeculae, and irregular calcification, which were shown on the radiograph and which were caused by high blood levels of PCB, changed gradually. However, the patient had periodontal disease because of horizontal alveolar bone resorption and a deep periodontal pocket, despite good plaque control. After the PCB poisoning the tooth roots were hypoplastic and dilacerated. One root was extracted because of chronic periodontitis. Some teeth were impacted, malposed, or ankylosed.

Adolescent↗
PubMed1992

Myocardial energy metabolism in asphyxiated canine hearts preserved for 24 hours.

Myocardial energy metabolism in asphyxiated cadaver hearts preserved in UW solution (UWS; group 1, n = 6) or modified Collins' solution (MCS; group 2, n = 6) was compared with that in cardioplegic arrested hearts immersed in ice-cold MCS with (group 3, n = 6) or without myoprotective drugs (group 4, n = 5). All hearts were stored for 24 hr. The hearts in groups 1 and 2 were pretreated with prostacyclin, verapamil, and propranolol; asphyxiated for 10 min, reversed by coronary perfusion with warm blood cardioplegia (WBCP); perfused with ice-cold crystalloid cardioplegia for 2 hr; excised and immersed in cold storage solution for 22 hr; and perfused again with WBCP before reperfusion. ATP contents were measured in biopsy specimens by HPLC. Myocardial ATP level decreased significantly from 23.7 +/- 1.7 to 15.9 +/- 2.5 mumol/g dry wt. (P less than 0.0001) by asphyxia, but recovered to within normal limits by WBCP in group 1. The ATP level again decreased to 15.8 +/- 2.4 mumol/g dry wt. during 24-hr storage, but finally rose to 22.4 +/- 3.5 mumol/g dry wt. by terminal WBCP. The ATP metabolism in group 2 was similar to that in group 1. The ATP content in group 4 was significantly lower than that in other groups (P less than 0.01) after 24-hr preservation. The study shows that damage to cadaver hearts can be reversed and the hearts maintained satisfactorily viable for 24 hr.

Adenosine Triphosphate↗
PubMed1992

Enteric adenovirus type 41 isolates: cloning, physical maps and diversity in restriction enzyme cleavage pattern.

Adenovirus (Ad) type 40 and 41 DNAs were directly extracted from stool specimens of children with gastroenteritis. Two new strains of Ad41, Sanekata and Ehime strain, were cloned and their restriction maps were constructed. The left terminal end of the cloned Ad41 genome, EcoRI-E fragment of the Sanekata strain and EcoRI-F fragment of the Ehime strain, had transforming ability in rat 3Y1 cells. Only one of the 35 isolates of Ad40 tested showed a different restriction profile, while three different restriction profiles were found in DNAs from Ad41 isolates.

Adenovirus Infections, Human↗
PubMed1992

Characterization of serum antibody responses to natural rotavirus infections in children by VP7-specific epitope-blocking assays.

Knowledge of the immune response to rotavirus is crucial for vaccine development. We compared an epitope-blocking assay (EBA) that uses VP7-specific monoclonal antibodies with neutralization assays (NAs) with polyclonal antisera for detecting serum antibody responses after natural rotavirus infection in children. Twenty-six serum pairs from children living in an orphanage with and without symptoms during two rotavirus outbreaks were evaluated for VP7 type 1-, 2-, 3-, and 4-specific antibody responses. In the first outbreak, which was caused by a VP7 type 3 strain, homotypic antibody responses were detected in 11 of 11 symptomatic children by NA and in 10 of 11 symptomatic children by EBA. Heterotypic antibody responses were detected more frequently (12 of 15 children) by NA than by EBA, and the heterotypic epitope-blocking antibody responses occurred in children older than 14 months of age. Antibody responses in asymptomatic children were more commonly detected by EBA than by NA. EBA results from the sera of children in the second outbreak indicated that it was caused by VP7 type 4, whereas NA results suggested it was caused by VP7 type 3. Our results confirm that EBA is a sensitive and specific method for determining VP7 type-specific immune responses after natural rotavirus infections.

Antibodies, Viral↗
PubMed1992

[The effect of sodium-4-[2-(2,3-dimethyl-4-[1-(4- isobutylphenyl)ethoxy]benzolamino)phenoxy] butyrate (ONO-3805) and antiandrogenic agents on the rat accessory sex organs].

The effects of sodium-4-[2-(2,3-dimethyl-4-[1-(4-isobutylphenyl) ethoxy]benzolamino)phenoxy]butyrate (ONO-3805), newly developed as a non-steroidal 5 alpha-reductase inhibitor, on rat accessory sex organs was compared with chlormadinone acetate (CMA) and non-steroidal antiandrogen, flutamide (FLU). ONO-3805 demonstrated excellent antiandrogenic activity which was similar to that of CMA in reducing the accessory sex organ weight. Moreover this agent did not show any significant effects on the serum testosterone level, but CMA and FLU changed it significantly. We previously reported the androgenic activity of antiandrogen (CMA, FLU, AA560, cyproterone acetate, medroxy progesterone, estrogen), but ONO-3805 is free of androgenic activity.

5-alpha Reductase Inhibitors↗