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Biomedical subjects

Y Kon

Publications and source records attributed to Y Kon.

At least 91 records · Page 5Linked to original sources
PubMed1993

Hypersensitivity of LEC strain rats in radiation-induced acute bone-marrow death.

LEC strain rats, which have been known to develop hereditarily spontaneous fulminant hepatitis 4 to 5 months after birth, were highly sensitive to whole-body X ray-irradiation as compared to WKAH strain rats. Radiation-induced acute bone-marrow death occurred at doses higher than 2.0 Gy in LEC rats, and at doses higher than 7.4 Gy in WKAH rats, respectively. By probit analysis of survival data, it was shown that the LD50/30 value for LEC rats was 3.0 Gy which was significantly lower than that (7.8 Gy) of WKAH rats. Histopathological examinations of the bone marrows from both strains after irradiation at a dose of 4.0 Gy revealed that a number of hemopoietic cells were recovered in WKAH rats on day 8 after irradiation, but not in LEC rats. These results suggested the hypersensitivity of LEC rats to ionizing radiation in connection with acute bone-marrow death.

Animals↗
PubMed1993

A simple method of hybridohistochemistry for detection of renin mRNA in the mouse kidney.

Hybridohistochemistry was applied for the detection of renin mRNA in the mouse kidney with a digoxigenin-labeled probe, synthesized as the sense and antisense RNAs from Ren-1 cDNA in the presence of digoxigenin-dUTP. Renin mRNA was detected in the juxtaglomerular cells located in the vicinity of the glomerular vascular poles of the kidney using the digoxigenin-labeled antisense RNA as a probe. Using the sense RNA as a probe, no signal was detected anywhere. In neighboring serial sections, the same cells reacted immunohistochemically to rabbit anti-mouse submandibular gland renin serum as in hybridohistochemistry. As we used the probe labeled with digoxigenin as a non-radioisotopic marker, there was no need for special handling other than that in immunohistochemistry. It was concluded that the simple procedure given in the present study is useful for the detection of mRNA.

Animals↗
PubMed1993

Distribution of T cell subsets in chicken lymphoid tissues.

The distributions of T cell subsets in chicken lymphoid tissues were investigated immunohistochemically using monoclonal antibodies (Lc-6, Lc-4) with specificity for chicken CD4 and CD8, respectively. In thymic tissues, CD8+ cells were found only in the cortex, while CD4+ cells were detected not only in the cortex but also in the medulla. The cortex just below the capsule demonstrated no immunoreactivity to either antibody. In the cecal tonsile, CD8+ cells were found restrictly in the subepithelial lamina propria. It was noted that the germinal centers were clearly surrounded with many CD4+ cells in the mid and deep portions of the lamina propria. In the spleen, clusters of CD8+ cells were observed only in the red pulp. Most lymphocytes in the periarteriolar lymphatic tissue and perivenous lymphatic tissue showed a CD4-positive reaction. No lymphocyte in the germinal centers reacted with these two monoclonal antibodies. No immunoreactivity for either CD8 or CD4 was detected anywhere else in the bone marrow or bursa of Fabricius. In the case of exposure to the protein antigen (alum-precipitated bovine serum albumin), CD4+ cells were demonstrated in some germinal centers, which were increased in size, while the areas expressing CD8 in the red pulp were decreased in size. These results suggest that the preferential distributions of T cell subsets are inherent in chicken lymphoid tissues.

Animals↗
PubMed1993

Solitary metastasis from papillary thyroid carcinoma in cirrhotic liver with hepatocellular carcinoma.

We report a surgical case of hepatocellular carcinoma and solitary liver metastasis from papillary thyroid carcinoma in different lobes of the liver. The former, located in the right anterior superior segment, and the latter, in the left caudate lobe, were resected simultaneously. The hepatocellular carcinoma was a micro(thin)-trabecular, pseudoglandular type of Edmondson's grade II. The liver metastasis was a papillary carcinoma of follicular variant from the thyroid. This is the first report of hepatocellular carcinoma accompanying a solitary liver metastasis from papillary thyroid carcinoma without metastasis in other organs.

Carcinoma, Hepatocellular↗
PubMed1992

[CT of pulmonary dirofilariasis--differential diagnosis from lung cancer].

We present here four cases of pulmonary dirofilariasis in which histological examination of the surgical specimen showed occlusion of the peripheral pulmonary artery by filariae and formation of a necrotic mass surrounded by reactive inflammation and hemorrhage. Radiological examination showed a solitary pulmonary nodule in three cases and a wedge-shaped consolidation in one case. Although pulmonary nodules in dirofilariasis closely mimic bronchogenic carcinoma on radiographs , it is possible to distinguish them from bronchogenic carcinoma on the basis of the following findings: (1) coexistence of subtle satellite lesions, (2) absence of pleural involvement, (3) fine marginal speculations, and (4) lack of concentric marginal speculations (eccentric speculation). In each case of dirofilariasis, CT showed the peripheral pulmonary artery entering the mass. This finding differentiates this disease from metastatic lung tumor, because in tumor metastasis via the pulmonary arteries, visible vessels are not usually involved.

Aged↗
PubMed1992

Morphological and northern blot analysis of juxtaglomerular cells in experimental hydronephrotic mice.

The purpose of this study is to demonstrate the developmental changes of the experimental hydronephrotic kidney using immunohistochemical, histoplanimetrical, and Northern blot techniques. At 1 month after ligation of the ureter, a large number of renin-positive cells were detected immunohistochemically even at a dilution of 1:10,000 in this hydronephrotic kidney; however, there were few renin-positive cells in the non-ligated side. At 6 months after ligation, no difference in reactivity for renin between ligated and non-ligated kidneys was demonstrated. In the morphometrical analysis of the renin-positive region, the numerical value of the ligated side was already increased at 2 weeks, reached the highest value at 1 month, and then decreased gradually to almost the same value as the control kidney by the end of the experiment. On the other hand, the value of the non-ligated side decreased immediately after the unilateral ligation, increased later, and finally reached almost the same value as the control kidney. In the Northern blot analysis, the activity of renin mRNA in the ligated side at 1 month after ligation was markedly higher than that in the non-ligated side. However, the difference between the ligated and the non-ligated sides was not demonstrated at 6 months and the value came to be almost the same as in the non-operated kidney.

Animals↗
PubMed1992

Influence of oral metronidazole on the endocrine milieu and sebum excretion rate.

As part of a study of the mechanism of metronidazole's efficacy in the treatment of acne and rosacea, its effects on the endocrine milieu and sebum excretion rate were assessed. Thirteen healthy males received oral metronidazole treatment (500 mg/day) for 4 weeks. Serum sex hormone levels were determined in all 13 subjects and the sebum excretion rate was determined in seven of them, before and after treatment. We measured serum levels of estrone (E1), estradiol (E2), total testosterone (T), free testosterone (FT), dihydrotestosterone (DHT), dehydroepiandrosterone sulfate (DHEA-S), and sex hormone-binding globulin (SHBG). There were no significant changes in E1, T, FT, DHT, or SHBG levels, but E2 and DHEA-S levels decreased significantly after treatment. In all seven subjects in whom the sebum excretion rates were determined, the amount of facial skin surface lipids decreased significantly after treatment. These results suggest that metronidazole exerts its clinical effects through suppressing the sebum excretion by a mechanism other than anti-androgenic action.

Administration, Oral↗
PubMed1992

An immunoelectron-microscopical observation of mouse juxtaglomerular cells in the case of experimental hydronephrosis.

Changes in juxtaglomerular (JG; renin-containing) cells in experimental hydronephrosis 1 month after ureteral ligation were investigated with immunoelectron-microscopical techniques. Two types of granules, electron dense (D) and lucent (L), were observed. D type granules were labeled more intensely with gold particles than those of L type. Granules intermediate between D and L types and exocytosis of D types were observed. In the cells containing D types exclusively, gold particles were restricted to the granules, whereas in the cells containing both D and L type granules, the particles were scattered throughout the cytoplasmic cytosol. The authors discuss the mechanisms of renin release in JG cells.

Animals↗
PubMed1992

Higher sensitivity of LEC strain rat in radiation-induced acute intestinal death.

LEC strain rats (LEC rats), which have been known to develop hereditarily spontaneous fulminant hepatitis 4-5 months after birth, were highly sensitive to whole-body X-irradiation as compared to WKAH strain rats (WKAH rats). Radiation-induced acute intestinal death occurred at doses higher than 6.5 Gy in LEC rats, and at doses higher than 12.8 Gy in WKAH rats, respectively. By the probit analysis of survival data, it was shown that the LD50/7 value of LEC rats was estimated to be 7.03 Gy which was significantly lower than that (12.99 Gy) of WKAH rats. Histopathological examinations of small intestines from LEC rats 2 days after irradiation at the dose of 8.5 Gy showed severe epithelial death together with edema, whereas little or no significant changes were noted in intestinal epithelium of 8.5 Gy-irradiated WKAH rats. These results suggest that the radiosensitivity of LEC rats to ionizing radiation appears to be higher than that of other strains of rats.

Animals↗
PubMed1992

Are there M cells in the cecal tonsil of chickens?

A unique morphological cell type, "microfold or membranous (M) cell-like cell", was detected electron-microscopically in the cecal tonsil epithelium of the chicken. M cell-like cells possessed a few short microvilli of irregular arrangement and a large number of lymphocytes and macrophages wedged into their basal surfaces. Triticum vulgaris was found to bind to M cell-like cells. With horseradish peroxidase (HRP) treatment, M cell-like cells showed an active HRP uptake just as did the neighbouring usual absorptive epithelial cells. No uptake of colloidal carbon particles from the intestinal lumen was recognized in any part of the intestinal epithelium. These results suggest that M cell-like cells of the chicken possess some M cell-characteristic morphological and histochemical features, but that their active uptake of foreign materials is not so developed as in mammalian M cells.

Animals↗
PubMed1992

[Progressing cases from low tone sudden deafness to Menière's disease--cochlear impairment in the so-called pre-Menière's disease period].

Among 80 patients with low tone sudden deafness (LTSD) who visited our department over the past 15 years, there were 6 cases (7.5%) who subsequently progressed to Menière's disease. The clinical and audiological processes of the 6 patients were studied in detail and the following results were obtained. (1) In these 6 patients, the time between onset of LTSD and the diagnosis of Menière's disease ranged from 4 months at the shortest to 6 years and 8 months at the longest, 2 years and 9 months on average. (2) Two pattern types were seen in the change from LTSD to Menière's disease: changing within a short period of time after recurrence of an LTSD-like attack, and changing after more than one year without recurrent attack. (3) The monoattack-nonrecovered type of LTSD and the recurrent type of LTSD within three months after the onset (short-term prognosis) frequently progressed to Menière's disease. (4) There were no close relationships between subjective symptoms and audiological features in the pre-Menière's disease period (from the onset of LTSD to the recurrence of vertigo with cochlear symptoms). (5) The 6 patients showed various audiogram shapes at the time of progression to Meniere's disease; 3 cases with the slightly rising type, 1 with the high frequency-impaired type, and 2 with the moderate, gradual and flat type. (6) Of the 6 patients, 3 had good hearing during long term observation. At least 2 patients seemed to have the mild type of Menière's disease.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1992

[Study of tinnitus masking by self-recording audiometer].

The tinnitus masking test, in which the minimum masking levels of tinnitus by various pure tones and band noises are measured and used to produce tinnitus masking curves, is one of the methods for evaluating the character of tinnitus. At present, the tinnitus masking test is usually performed using a pure tone audiometer. In this study, tinnitus masking curves were produced using a self-recording audiometer (Bekesy audiometer) in 22 cases of tinnitus, and the basic nature of the tinnitus masking curves from the self-recording audiometer was investigated and compared with those from a pure tone audiometer. The results showed no changes in the masking level, and the amplitudes of the tinnitus masking curves from the self-recording audiometer were observed to be at the tinnitus pitches. The amplitude of the tinnitus masking curve showed a negative correlation with tinnitus loudness as measured by the loudness balance test for tinnitus, that is, the amplitude tended to decrease as the tinnitus became louder. This suggests that the loudness of the masking tone influences the tinnitus masking phenomenon.

Audiometry, Pure-Tone↗
PubMed1992

Comparative study of renin expression in the coagulating glands of C57BL/6 and Balb/c mice.

The comparative localisation of renin in the genital organs, especially in the coagulating glands of male mice of the strains C57BL/6 and Balb/c, was investigated using immunocytochemical, immunoelectron microscopical and Northern blot techniques. Dot-like reactions for renin, of varying diameters, were detected immunocytochemically in the epithelial cells of coagulating glands of C57BL/6 mice, but not in those of Balb/c mice. In both strains, many electron dense granules differing in content and morphology were observed in the epithelial cells of the coagulating glands. Crystalline materials were sometimes contained in these granules. Colloidal gold particles indicating the presence of renin were detected in the electron dense granules of C57BL/6 mice, in which they showed a heterogeneous distribution and were especially located on the crystalline structure. No positive reaction was detected in these crystalline structures in Balb/c mice. Renin mRNA was detected in the coagulating glands of both C57BL/6 and Balb/c mice by Northern blot analysis. However, the expression in C57BL/6 coagulating glands was stronger than that in Balb/c. These findings suggest that renin is synthesised and released in the coagulating glands.

Animals↗
PubMed1992

[Studies on the glucose tolerance and the endocrine function of the pancreas in primary sclerosing cholangitis].

The responses of serum IRI, serum IRG, and blood sugar levels to 75 g oral glucose and serum IRI to glucagon injection were investigated in 26 chronic hepatitis, 20 liver cirrhosis, 5 primary sclerosing cholangitis (PSC) and 8 healthy volunteers served as controls. The results obtained herein were as follow: 1) The frequency of the glucose intolerance in PSC was higher than the other liver diseases. The mean values of the insulinogenic index (delta IRI/delta BS 30 min) in PSC was lower than control subjects. No suppression of IRG by glucose was observed in PSC. 2) The maximum IRI value (max delta IRI) in PSC during glucagon test was lower than that in control subjects. 3) In one case of 5 PSC ICSA was founded to be positive. These data suggest that we should pay much attention to suffering from diabetes mellitus in natural history of PSC.

Aged↗
PubMed1991

Human renin in transgenic mouse kidney is localized to juxtaglomerular cells.

To examine whether expression of human renin in the transgenic mouse kidney is regulated in a cell-specific manner, we have characterized monoclonal antibodies against human renin and determined the renin-production site by immunohistochemistry. By using a monoclonal antibody specific for human renin, A6-11-6, we demonstrated that human renin in the transgenic mouse kidney is localized to the juxtaglomerular cells of afferent arterioles.

Animals↗
PubMed1991

[A study on auditory disturbances after microvascular decompression for hemifacial spasm].

After establishing an operation of microvascular decompression by Jannetta in 1975, an improvement rate of hemifacial spasm have increased. However, postoperative hearing deficits, equilibrium disturbances and facial paresis have been described in some publications. Fifty-seven of 119 patients with hemifacial spasm operated from 1982 to 1989, were examined by audiometry before and after operation. In patients with tinnitus at the time of facial spasm and closing eyelids, tinnitus improved almost in many cases. Of 57 patients, 8 (5 with sensorineural hearing loss, 3 with conductive hearing loss) had postoperative hearing impairments in operated ears, and 7 (7 with sensorineural hearing loss) had in the other ears, too. Of 7 patients having sensorineural hearing loss observed for several months, 4 having slight sensorineural hearing loss recovered at the same hearing level before operation. In 2 patients having profound sensorineural hearing loss, however, hearing improvement did not observed in each case.

Adult↗
PubMed1991

An immunohistochemical study of the gastro-entero-pancreatic endocrine cells in the alimentary tract of the Korean tree squirrel, Sciurus vulgaris corea.

The regional distribution and relative frequencies of gastrointestinal endocrine cells were studied immunohistochemically in the gastrointestinal mucosa of Korean tree squirrels. Seven kinds of endocrine cells were identified in this study. Although a large number of 5-hydroxytryptamine-immunoreactive cells were seen throughout the gastrointestinal tract, they were most predominant in the duodenum. A moderate number of glucagon-immunoreactive cells which were restricted to the cardia and fundus of the stomach was also observed. Bovine chromogranin-immunoreactive cells were numerous in the cardia and pylorus of the stomach, found in moderate numbers in the fundus, duodenum and large intestine, but rare in the jejunum. Porcine chromogranin-immunoreactive cells were found in moderate numbers in the stomach but were rare in the duodenum. Gastrin/cholecystokinin-immunoreactive cells were abundant in the pyloric gland region but scarce in the duodenum. Bovine pancreatic polypeptide-immunoreactive cells were observed to be rare and found only in the pyloric gland region. Somatostatin-immunoreactive cells were distributed moderately in the stomach but were few in number in the intestine. No insulin-immunoreactive cells were found in the gastrointestinal tract of Korean tree squirrels. These results suggest that although the Korean tree squirrel is a herbivorous rodent, the distribution pattern of its gastro-entero-endocrine cells is rather similar to that reported for omnivorous animals.

Animals↗