Biomedical subjects
Publications and source records attributed to K Ohta.
The mechanical filtration coefficient (Lp) of the membrane of cultured glioma cells was determined from the rate of swelling of the cells. The swelling was induced by exposing the cells to distilled water. Assuming that cells swell in a symmetrical manner, Lp was 2.2 x 10(-8) cm/s.mmHg, or 1.7 x 10(-4) microns/s.cmH2O when calculated from changes of the cell diameter.
Phosphorus has been determined by electrothermal atomisation atomic absorption spectrometry with a molybdenum tube atomiser. The effects of interferents on the phosphorus signal have been investigated. Chemical interferences were eliminated by high-temperature pyrolysis. The detection limit for the molybdenum tube system was 2.3 ng (corresponding to 2.3 micrograms ml-1 when 1 microliter was injected into the atomiser) and the characteristic mass was 1.9 ng of phosphorus. A calibration graph method combined with high-temperature pyrolysis has been evaluated through the determination of phosphorus in biological materials. The sensitivity, accuracy and precision of the method were superior to or nearly equal to those of graphite furnace atomic absorption spectrometry. The advantages of the high-temperature pyrolysis method are its simplicity and low cost.
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The effect of sofalcone on the glandular structure and cell proliferation in the gastric mucosa of rats with gastritis induced by the administration of sodium taurocholate (TCA) for 6 months was examined by histoquantitative analysis and [3H]thymidine autoradiography. Morphometric observation revealed that, with TCA treatment, mucosal thickness, parietal cell mass, and the ratios of the length of the glandular portion/total length of the gastric gland were decreased in both the fundic and pyloric glands. Inflammatory cell infiltration and collagenous fiber proliferation were present in the gastric mucosa following TCA and indicated the presence of atrophic gastritis. These atrophic changes and inflammatory cell infiltration were reversed by a 3 week administration of sofalcone. Cellular proliferative activity assessed by the labeling indices of the gastric mucosa increased in TCA-induced gastritis in rats. The administration of sofalcone to rats with TCA-induced gastritis significantly increased labeling indices, particularly in the pyloric glands. From these results, it appears that sofalcone stimulates the compensatory increase in proliferative activity of generative cells, which then may become available to heal the gastritis.
The pancreases of 92 autopsied patients were evaluated to determine the influence of clinicopathological conditions upon the extent of postmortem autolysis. The postmortem interval was the most important factor influencing postmortem autolysis. In order to more precisely evaluate the influence of associated factors upon the extent of postmortem autolysis in the pancreas, quantification I of multivariate statistical analysis was used. Twelve factors such as postmortem interval, mode of death, malignant neoplasia as an underlying cause of death, and history of abdominal surgery were chosen for analysis. The multiple correlation coefficient (R2) was 0.71. In the case of unexpectedly severe or unexpectedly mild postmortem autolysis, we suggest that these 12 factors should be taken into close consideration whether or not the postmortem interval is long or short.
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The benzoylarginine peptidase of Treponema denticola (strain ASLM; a human oral spirochaete) was progressively and irreversibly inactivated by 1-(ethoxycarbonyl)-2-ethoxy-1, 2-dihydroquinoline, a carboxyl-group reagent. At acidic pH values, reaction of one mole of the modifier per active site of the enzyme resulted in total inactivation of the enzyme. Assuming that this modifier is a specific carboxyl reagent, the data suggest that the inactivation of the T. denticola benzoylarginine peptidase was caused by the modification of one carboxyl group located close to the active site of the enzyme. Results obtained with Woodward's reagent K (N-ethyl-5-phenylisoxazolium 3'-sulphonate) supported these findings. Carbethoxylation with diethylpyrocarbonate effectively inactivated the enzyme, and addition of hydroxylamine at pH 7.0 restored the activity almost totally, suggesting that the pyrocarbonate had reacted with tyrosyl or histidyl residues.
The antimicrobial activity of clarithromycin was compared with that of erythromycin in experimentally infected mice by whole-body autobacteriography. In mice with systemic staphylococcal infections, the number of vital microbes in the body was relatively low in the early period after oral administration of erythromycin, but increased thereafter to the levels found in nonmedicated control mice. On the other hand, with clarithromycin treatment, a significantly smaller number of microbes was evident throughout the body. The microbes were scarcely seen in the parenchyma of any organs during the examination period. This potent antimicrobial activity of clarithromycin compared with that of erythromycin was further demonstrated in mice with respiratory infections. On the other hand, to examine the distribution properties of both antibiotics in the whole body, an autoradiographic study was carried out with [N-methyl-14C]clarithromycin and [N-methyl-14C]erythromycin. Both labeled antibiotics were distributed widely throughout the body after oral administration in both uninfected control mice and mice with systemic infections. However, the radioactivity was more marked and persistent for [14C]clarithromycin than it was for [14C]erythromycin, particularly in the lungs. The observations described above indicate the superior in vivo antimicrobial activity of clarithromycin compared with that of erythromycin and suggest that the superiority of clarithromycin is largely attributed to its favorable distribution properties. The advantages of whole-body autobacteriography, coupled with whole-body autoradiography, are discussed.
In batch fermentations, optimal conversion of xylose to ethanol by recombinant Escherichia coli was obtained under the following conditions: 30 to 37 degrees C, pH 6.4 to 6.8, 0.1 to 0.2 M potassium phosphate buffer, and xylose concentrations of 8% or less. A yield of 39.2 g of ethanol per liter (4.9% ethanol by volume) was observed with 80 g of xylose per liter, equivalent to 96% of the maximum theoretical yield. Maximal volumetric productivity was 0.7 g of ethanol per liter per h in batch fermentations and 30 g of ethanol per liter per h in concentrated cell suspensions (analogous to cell recycling).
We evaluated the effect of acute unilateral renal denervation (DNX) on the tubuloglomerular feedback (TGF) mechanism in Inactin-anesthetized hydropenic male 8- to 10-wk-old spontaneously hypertensive rats (SHR) and Wistar-Kyoto rats (WKY). SHR had higher mean arterial pressure (MAP, 28%) and renal vascular resistance (RVR, 35%), whereas renal blood flow (RBF), glomerular filtration rate (GFR), urine flow, and sodium excretion were similar. DNX in SHR did not change MAP but decreased RVR (26%) and increased RBF (29%), GFR (16%), urine flow (52%), and sodium excretion (431%). DNX did not affect these in WKY. Loop of Henle perfusion with Ringer solution reduced early proximal flow rate (EPFR) in SHR more than in WKY; significantly different at a loop flow of 20 nl/min (9.8 +/- 0.7 vs. 6.5 +/- 0.7 nl/min). DNX in SHR increased the nonperfused EPFR from 25.6 +/- 1.1 to 31.7 +/- 1.3 nl/min and reduced TGF responses during perfusion at both 20 nl/min (9.8 +/- 0.7 vs. 4.4 +/- 0.7 nl/min) and 40 nl/min (14.2 +/- 1.1 vs. 10.4 +/- 0.7 nl/min). TGF sensitivity was attenuated by DNX, as indicated by reduced maximum reactivity (-0.89 +/- 0.14 to -0.36 +/- 0.07) and increased turning point (16.5 +/- 0.9 to 25.2 +/- 2.9 nl/min). TGF responses in WKY were not influenced by DNX. Sham denervation did not alter renal hemodynamics and TGF. These results indicate that renal nerves exert a tonic influence on the renal vasculature and the TGF system in SHR but not in WKY. Enhanced TGF responsiveness may be involved in volume retention and in the maintenance of hypertension in SHR.
Endothelin-1 is a novel endothelium-derived vasoconstrictive peptide. Using a highly specific and sensitive radioimmunoassay for endothelin-1, plasma levels of immunoreactive endothelin-1 were measured in 32 research subjects with normal renal function (21 normal subjects and 11 patients with essential hypertension), 24 patients with nondialyzed chronic renal failure, and 51 patients undergoing maintenance hemodialysis. Although there was no significant difference in plasma immunoreactive endothelin-1 levels among the three groups, patients with essential hypertension had significantly higher plasma endothelin-1 levels than normal subjects (2.29 +/- 1.09 vs. 1.41 +/- 0.50 pg/ml, p less than 0.025). When nondialyzed and hemodialyzed patients were divided into hypertensive and normotensive groups, the nondialyzed hypertensive group (n = 17) had higher plasma endothelin-1 levels than the comparable normotensive group (n = 7) (3.08 +/- 3.43 vs. 0.73 +/- 0.34 pg/ml, p less than 0.05), and the hemodialyzed hypertensive group (n = 18) had higher plasma endothelin-1 levels than the comparable normotensive group (n = 33) (2.66 +/- 1.92 vs. 1.35 +/- 0.73 pg/ml, p less than 0.005). Plasma atrial natriuretic factor, arginine vasopressin, renin activity, and aldosterone concentration did not show significant differences between hypertensive and normotensive individuals or a correlation with plasma endothelin-1 levels. These data suggest that circulating endothelin-1 may be partly involved in the development or maintenance of hypertension in humans.
We measured the amount of antibodies to a synthetic peptide that corresponds to the alpha-subunit residues Lys125-Thr148 of human acetylcholine receptor (AChR) in myasthenic sera. We detected anti-peptide antibodies in 52% (89/171) of the patients with myasthenia gravis (MG), but none in any of the healthy controls. Anti-peptide antibodies should provide a valuable immunologic parameter for the clinical evaluation of MG, but no apparent correlation was observed between the titers of anti-peptide and anti-AChR antibodies.
Relations between successive changes of the microvascular architecture and osseous healing in the restorative process of supporting structures of endosseous implants were experimentally investigated on plastic microcasts of blood vessels under SEM. Sixty days after upper incisor extractions of Japanese monkeys (Macaca fuscata), titanium, notch and screw-typed, and bioceram-anchorpin were implanted. The animals were sacrificed at postoperative 1, 2, 4, 9 weeks, respectively. Acryl plastic was injected via the common carotid arteries. Microvascular casts together with bone element of the maxillae were prepared for SEM as well histological slides for light microscope. One week after implantation, sinusoidal vessels sprouted out of pre-existing vessels including leakages of the injected plastic. Two weeks, these sinusoids began to be sorted out. Newly formed, stalked bone trabeculae reached the implant surface, where each of them has enlarged as an island like piece. Four weeks, these pieces have been connected with each other by adhesion. Outside the new bone, blood capillaries sorted out have formed a cylindrical plexus. These successive osseous integration surrounding the implant has continued until about 9 weeks. In conclusion, it can be said that the period of 4-6 weeks after implantation was most important and significant to be established the osseous integration.
Between September 1982 and May 1984, combination chemotherapy with cis-platinum, peplomycin and adriamycin was administered to 12 patients with histologically confirmed adenocarcinoma of the prostate and progressive disease with evaluable parameters. Cis-platinum (CDDP) 20 mg/sqm was administered intravenously on Days 1-5, peplomycin 5 mg/sqm by 24-hour continuous drip infusion on day 1-5 and adriamycin 25 mg/sqm on Day 1. This course was repeated every 28 days. The dose and schedule were modified by hematologic toxicity or other side effects. One patient refused therapy because of severe nausea and vomiting; therefore 11 patients were eligible for response evaluation. Of the 11 patients, two had a documented PR, five had SD and four had PD. Ten patients whose disease eventually progressed received a second line of therapy consisting either of estramustine or estrogen. Of these ten patients, 6 had a documented PR, one had SD and three had PD. It is concluded that this combination chemotherapy regimen may prime advanced prostatic cancer to respond to hormonal therapy, even though it has only a limited effect on advanced prostatic cancer.
In mice carrying the autosomal recessive gene weaver, there is a massive postnatal loss of dopamine in the caudoputamen, the target of the nigrostriatal system, with relative (though not complete) preservation of dopamine in the ventral striatum, a target of the mesolimbic system. There is concomitant death of catecholaminergic neurons in the substantia nigra, with much less cell death in the limbic midbrain area. In the study reported here, we have reexamined the mesostriatal system of weaver mice by means of tyrosine hydroxylase (TH) immunohistochemistry in order to determine the local architecture of the defect within the striatum and substantia nigra. For the dorsal striatum, the most striking finding was the appearance in the weaver caudoputamen of small pockets of especially weak immunostaining within a larger dorsal zone of generally reduced TH-positive neuropil. These pockets were identified as striosomes by calbindin28k and met-enkephalin immunohistochemistry carried out on adjacent sections. In dorsal, central, and caudal sectors of the caudoputamen, there was also more generalized depletion of TH-immunoreactive neuropil. In the mid-brains of the mutants, the patterns of loss of TH-positive neurons appeared to correspond to these distributions of reduced immunostaining in the striatum. In the substantia nigra pars compacta, ventrally situated TH-positive neurons were especially affected, suggesting preferential depletion of TH-positive neurons projecting to striosomes. In addition, there was a central sector of nearly complete loss of TH-positive neurons in the substantia nigra para compacta and a marked depletion of TH-positive neurons in cell group A8 that, together, may have accounted for the diminution of TH-positive innervation of the striatal matrix. We conclude that the effects of the weaver gene discriminate among mesostriatal subsystems not only according to the regional affiliations of these subsystems within the dorsal and ventral striatum, but also according to the preferential association of the subsystems for the striosomal and matrical compartments of the caudoputamen. The depletion of TH-positive innervation was not confined to the dorsal striatum proper. The defect extended into the adjoining nucleus accumbens, where it appeared to affect the lateral "core" division, and included also a lateral part of the olfactory tubercle. Thus, as in the dorsal striatum, the defect in the TH-positive innervation of the ventral striatum closely follows the local architecture of this striatal region. Neuronal loss in the ventral tegmental area was not evident on qualitative analysis, but at the border between lateral cell group A 10 and medial cell group A9 there was obvious loss of immunostained neurons.(ABSTRACT TRUNCATED AT 400 WORDS)
We measured prostatic acid phosphatase (PAP), gamma-seminoprotein (gamma-Sm) and prostatic specific antigen (PSA) levels simultaneously in the serum of 52 patients with untreated prostatic cancer and 44 patients with benign prostatic hypertrophy to assess the clinical usefulness of these tumor markers. PAP and PSA were measured by radioimmunoassay and gamma-Sm by enzyme immunoassay. The positive rates of PAP, gamma-Sm and PSA in patients with prostatic cancer were 50.0, 61.5 and 69.2%, respectively, and those in patients with benign prostatic hypertrophy were 11.4, 13.6 and 13.6%, respectively. In patients with early stage prostatic cancer (stage A and B), the positive rates of PAP, gamma-Sm and PSA were 20.8, 41.7 and 54.2%. The efficiency of PSA was the highest among the three markers. The positive rate of the combination assay of PAP and PSA, that of gamma-Sm and PSA and that of PAP, gamma-Sm and PSA were slightly higher than that of the PSA assay alone. However, the efficiency of the PSA assay alone was higher than that of any combination. No significant correlation was found between histopathological grade and the level of each tumor marker. A significant correlation was found between PAP and gamma-Sm (r = 0.68, P less than 0.001), and between PAP and PSA (r = 0.61, P less than 0.001), but there was no correlation between gamma-Sm and PSA. These results suggest that PSA is the most useful marker and the combination assay of multiple markers is not so advantageous, at least for screening of prostatic cancer.
To demonstrate the clinical usefulness of the treadmill exercise test in patients with chronic lung diseases (CLD), 272 consecutive tests done from Jan. 1986 to Dec. 1988 were analyzed. The subjects mainly consisted of patients with chronic obstructive pulmonary disease (COPD) and interstitial lung disease (ILD). With the present incremental treadmill protocol the maximal stage attained by a patient or distance walked were closely related to the patient's maximal oxygen uptake. Comparing symptoms and cardio-pulmonary response, and exercise performance between patients with COPD and those with ILD, there was an evident difference in the exercise limiting factor (s): in the former ventilatory limitation was the most important whereas in the latter gas exchange and oxygen transport was critical. Assessment of breathlessness during the exercise test using the Borg scale was useful in evaluating various therapeutic modalities such as oxygen supplementation. In conclusion, the exercise performance in patients with CLD was properly assessed with the present treadmill protocol and the information derived thereby was of great clinical significance.
A new cell line designated RTSG established in vitro from the pleural effusion of a patient with metastatic ovarian epithelial cancer has been subcultured 46 times for more than 2 years. The cells grew in a monolayered sheet, showing a tendency to pile up, with the population doubling in 48 hrs. Electron-microscopically, desmosomes were characteristically observed, suggesting the cells were of epithelial origin. Chromosomal analysis revealed aneuploidy with a tetraploid mode. The heterotransplanted tumors in nude mice were histopathologically classified as a poorly differentiated adenocarcinoma, whereas the original tumor consisted mainly of mucinous and serous cystadenocarcinoma and only partly of poorly differentiated adenocarcinoma. The cells secreted hCG (38.8 mIU/day/10(6) cells) and beta-hCG (6.1 ng/day/10(6) cells) in spent medium. Immunocytologic +-and-histochemical staining for tumor markers of the original tumor, the cultured cells and the transplanted tumors also revealed the localization of not only hCG and beta-hCG but also CA19-9 and CA-125 whose values had been elevated in the preoperative serum (hCG: 10 mIU/ml, CA19-9: 6,400 U/ml, CA-125: 225 U/ml). Results of PAS, Alcian-blue and Mucicarmine strains indicated that most of the PAS-positive substances in the cultured cells and the transplanted tumors were consistent with glycogen while the original tumor mainly contained mucin except for the lesion of poorly differentiated adenocarcinoma with glycogen. These results suggested that the cultured cells might originate from poorly differentiated adenocarcinoma cells in the original tumor.