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Biomedical subjects

Y C Kim

Publications and source records attributed to Y C Kim.

At least 271 records · Page 15Linked to original sources
PubMed1988

Immunocytochemical localization of aldolase in normal, denervated, and dystrophic chicken muscles.

To investigate whether immunocytochemical localization of muscle-specific aldolase can be used for fiber phenotype determination, we produced specific antibodies against the enzyme and studied its distribution in adult chicken skeletal muscles by indirect immunofluorescence microscopy. Monoclonal antibodies against the myosin heavy chains of fast-twitch (MF-14) and slow-tonic (ALD-58) muscle fibers were also used to correlate aldolase levels with the fiber phenotype. The goat anti-aldolase antibody was found to be specific for the A form of aldolase, as evidenced by sodium dodecyl sulfate gel electrophoresis, immunotitration experiments, and immunoblot analysis. The antibody reacted strongly with the fast-twitch myofibers of normal pectoralis and posterior latissimus dorsi muscles; the phenotype of these muscle fibers was confirmed by a positive immunofluorescent reaction after incubation with MF-14 antibody. By contrast, the slow-tonic myofibers of normal anterior latissimus dorsi, which react positively with ALD-58 antibody, reacted weakly with anti-aldolase antibodies. In denervated chicken muscles, reaction to anti-aldolase antibodies was markedly reduced in fast-twitch fibers, although reaction to MF-14 was not diminished. By contrast, in dystrophic muscle, fast-twitch fibers showed reduced reactivity to anti-aldolase and marked to moderate reduction in MF-14 reactivity. Our results show that: (a) in normal muscles, reactivity to anti-aldolase matches the phenotype obtained by using anti-fast or anti-slow myosin heavy chain antibodies, and therefore can serve to identify mature fibers as fast or slow; and (b) in denervated or dystrophic muscles, the intracellular expressions of aldolase and fast-twitch myosin heavy chains are regulated independently.

Animals↗
PubMed1988

Cystic fibrosis--a case presented with recurrent bronchiolitis in infancy in a Korean male infant.

The aim of this case report is to draw the attention to the occurrence of cystic fibrosis (C.F.) in a Korean infant and thus increase the awareness for the diagnosis. The male infant was presented with a history of recurrent bronchiolitis manifested by severe cough, wheeze and dyspnea from three weeks of age, in whom the diagnosis of C.F. was clinically suspected and was confirmed by demonstration of two elevated sweat chloride levels (97 mEq/L and 99 mEq/L) in the patient. The diagnosis was delayed because the main manifestations of C.F. were the same as the main symptoms of common diseases such as cough, diarrhea and failure to thrive. C.F. is probably underdiagnosed in Korean population both because the diagnosis is not considered since the disease is thought to be uncommon or even not to occur and because diagnostic facilities including the quantitative iontophoresis sweat test are lacking.

Bronchiolitis↗
PubMed1988

Expression of vitamin B12 R-binder in breast tumors. An immunohistochemical study.

Vitamin B12 R-binder, a vitamin B12-specific binding protein, was demonstrated by immunohistochemistry in 103 cases of breast tumors of various types and grades. In normal breast tissues, R-binder was found on the luminal surface of interlobular, intralobular, and small terminal ducts. R-binder localization was observed in all fibroadenomas and phyllode tumors, in 90% of the benign epithelial tumors, and in 33% of the carcinomas. Among malignant tumors, 43% of the ductal carcinomas expressed the R-binder, whereas none of the lobular or mucinous carcinomas were positive. In invasive ductal carcinomas, R-binder expression was demonstrated more often in well-differentiated lesions.

Breast Neoplasms↗
PubMed1988

Localization of transferrin within the developing vertebrate nervous system.

Transferrin is one of several serum proteins localized within neurons during development of the nervous system. The expression of transferrin receptors appears to precede the active accumulation of transferrin by neurons. The first cells immunoreactive for transferrin appear adjacent to the ventricles or to the central canal of the spinal cord. These cells then appear to migrate from this site. These neurons become progressively more immunoreactive for transferrin, attain a peak of reactivity and then lose their reaction to antitransferrin antibodies. Thus, a "window" of transferrin immunoreactivity is found. As neurons lose their reactivity to antitransferrin antibodies, glia and the walls of capillaries become positive. In the rat nervous system, the gradual decrease in intraneuronal transferrin is accompanied by an increase in mitochondrial malate dehydrogenase, an enzyme of the tricarboxylic acid cycle. Thus, the accumulation of transferrin appears to closely precede the ontogeny of oxidative metabolism in the brain. As transferrin appears transiently in all neurons, this protein may be involved in a number of other important developmental events such as the expression of dopamine D2 receptors and the period of "programmed" cell death in the spinal cord.

Animals↗
PubMed1987

Immunohistochemical distribution of vitamin B12 R-binder in renal cell carcinoma.

Renal cell carcinomas and normal kidney tissues were examined for the expression of vitamin B12 R-binder by the indirect immunoperoxidase method. In normal kidney tissue, the presence of the vitamin B12 R-binder was shown to be confined to the straight portion (pars recta) of proximal tubules. Seven of the 38 cases of renal cell carcinoma (18%) expressed the vitamin B12 R-binder antigen. This provides a further evidence of the proximal tubular nature of renal cell carcinoma, and suggests that a small proportion of renal cell carcinomas originate from the straight portion of the renal proximal tubules.

Carcinoma, Renal Cell↗
PubMed1987

Absorption and metabolism of 5-(4-nitrophenyl)-2,4-pentadienal (Spydust).

5-(4-Nitrophenyl)-2,4-pentadienal (NPPD) was recently alleged to have been used as a tracking agent to monitor the activities of U.S. citizens in the Soviet Union. In order to better assess human risk from possible exposure to this compound the absorption and metabolism of [14C]NPPD has been investigated in male F344 rats. These studies have revealed that NPPD was readily and quantitatively absorbed from the gastrointestinal tract, distributed throughout the tissues, metabolized, and rapidly excreted primarily in urine. NPPD was sparingly absorbed following dermal administration of 0.01, 0.1, and 1.0 mg/cm2. The amount absorbed increased as the dose increased but the percentage of the dose absorbed decreased as the dose increased, e.g., 50% (5 of 10 micrograms applied) of the low dose was absorbed but only 5% (50 of 100 micrograms applied) of the high dose was absorbed. The material absorbed after dermal administration was rapidly excreted and the distribution and metabolism of the dermally administered compound was no different from oral administration. A total of five metabolites, 4-nitrocinnamic acid, 4-acetamidobenzoic acid, 4-nitrohippuric acid, 4-acetamidocinnamic acid, and 4-nitrobenzoic acid, were identified by cochromatography with authentic standards and comparison of UV spectra. These metabolites are formed by oxidative metabolism of the pentadienal side chain, reduction of the nitro group, and/or conjugation of the resulting amino group with acetate or carboxylic acid with glycine.

Administration, Cutaneous↗
PubMed1987

Comparative metabolism and excretion of resorcinol in male and female F344 rats.

Following oral administration, resorcinol was readily absorbed from the gastrointestinal tract, rapidly metabolized, and excreted by male and female rats. In both sexes, most of the dose of resorcinol (greater than 90%) was excreted in the urine within 24 hr after oral administration of 112 mg/kg, indicating little potential for bioaccumulation in animal tissues. Less than 3% of an oral dose was excreted in feces. An analysis of bile indicated that at least 50% of the dose excreted in bile undergoes enterohepatic circulation to be eventually excreted in urine. Little (less than 5%) of the parent compound was excreted in urine; most of the dose was in the form of three major and one minor metabolite. The relative amounts of metabolites excreted changed only slightly with time and dose administered. Approximately 70% of the total radioactivity in the urine of both sexes was in the form of a glucuronide conjugate. Female rats excreted a greater portion of the dose as a sulfate conjugate than males. Males excreted more of a diconjugate containing both sulfate and glucuronide groups. Repeated exposure to up to five daily doses resulted in no apparent alteration of the pattern of resorcinol absorption, metabolism, and excretion observed after a single dose.

Animals↗
PubMed1987

Complete nucleotide sequence of the penicillin G acylase gene and the flanking regions, and its expression in Escherichia coli.

The pga gene coding for penicillin G acylase (PGA) in Escherichia coli ATCC11105 was cloned, and its complete nucleotide sequence including 5'- and 3'-flanking regions was determined. Two nonidentical subunits that constitute an active PGA enzyme complex are known to be formed by processing of a common precursor molecule [Böck et al., FEMS Microbiol. Lett. 20 (1983) 141-144]. This novel type of protein processing was confirmed by a nucleotide sequencing study together with amino acid sequencing of two PGA subunits. In addition, it was found that the initiation codon, AUG, is preceded by an authentic ribosome-binding site, a consensus promoter sequence and putative cAMP receptor protein (CRP)-binding sites, and that the termination codon, UAA, is followed by a putative transcriptional terminator. The promoter function was confirmed by galactokinase assay using galK fusion plasmids. A recombinant plasmid was constructed to overproduce the enzyme using phage lambda pL promoter. Unexpectedly, thermal induction led to accumulation of the 94-kDa polypeptide rather than active PGA in large amounts. Western immunoblot analysis showed that this large polypeptide is the real precursor of PGA. It is evident, therefore, that the synthesis of active PGA in E. coli is affected by growth temperature and that the precursor processing step(s) is temperature-sensitive.

Amidohydrolases↗
PubMed1987

Unusual renal sarcoma in a young adult: its similarities to clear cell sarcoma of the kidney.

We report an unusual case of renal sarcoma in a young adult. Histological examination demonstrated many similarities to the histopathological features of clear cell sarcoma of the kidney. Immunohistochemically, none of the intrinsic tumor cells showed positive staining with the antibodies against the intermediate filament proteins, epithelial membrane antigen, S100 protein, neuron-specific enolase, Leu-7 or myoglobin. The clinical course of this tumor was that of high grade malignancy, resulting in death with generalized metastases 13 months after tumor resection.

Adult↗
PubMed1987

Expression of epithelial markers in sarcomatoid carcinoma: an immunohistochemical study.

Thirty-four cases of sarcomatoid carcinoma with minimal epithelial components (SC) and six cases of sarcomatous tumour without any epithelial component (ST) in various organs were studied by the immunoperoxidase technique for the expression of epithelial markers, cytokeratins and epithelial membrane antigen (EMA). Employing antibodies against both high and low molecular weight cytokeratins, sarcomatoid components in 30 examples of SC were stained positively. Epithelial membrane antigen was demonstrated in 19 out of 34 SC. The positive cells for epithelial markers within sarcomatoid components in some cases of SC, which were regarded as originating from squamous cell carcinoma, tended to be seen less frequently than in the tumours derived from adenocarcinoma or transitional cell carcinoma. In six cases of ST, stain for EMA was negative and stain for cytokeratins was positive in three examples. The immunohistochemical examination of epithelial markers in the tumours of these types may be of value in differentiating these tumours from true sarcomas.

Adenocarcinoma↗
PubMed1986

Brown tumor in secondary hyperparathyroidism causing acute paraplegia.

The first known case of a "brown tumor" associated with secondary hyperparathyroidism causing paraplegia is described. A 69-year-old white woman with chronic renal failure due to hypertension was admitted for back pain, and while she was under observation, paraplegia developed. A complete block was demonstrated by myelography. Computed tomography confirmed a mass at the level of obstruction, and results of biopsy were consistent with "brown tumor." Neurologic symptoms were markedly improved with high-dose corticosteroids and a debulking procedure. This entity is important to recognize because prompt treatment of the hyperparathyroidism or decompression of the tumor mass by surgical means or corticosteroid administration can provide marked improvement in symptoms.

Aged↗
PubMed1986

The effect of an unusual workshift on chemical toxicity. II. Studies on the exposure of rats to aniline.

Increasing numbers of workers in industry are working a novel or unusual 12-hr workshift in which the exposure time is longer and the recovery period is shorter than for a standard 8-hr workshift. Experiments were conducted to examine the effects of altering the exposure schedule of rats from 8 hr/day for 5 days to 12 hr/day for 4 days on the toxicity resulting from the inhalation of aniline at 10, 30, 50, and 150 ppm. When compared to the first day, methemoglobin (MetHb) levels, measured prior to and following the exposure, increased with the days of exposure at 50 ppm aniline. At 150 ppm aniline, the MetHb level determined prior to exposure to aniline increased with the days of exposure whereas the postexposure MetHb levels appeared to plateau after the second exposure. The MetHb levels determined prior to exposure were significantly different between the two groups at 50 or 150 ppm aniline whereas the postexposure MetHb levels were not. A residual MetHb level higher than the nonexposed control was observed in the 12 hr/day exposure group after a 3-day recovery period. There was an aniline concentration-dependent decrease in the hematocrit level when determined 1 week after the exposure started. Following a single exposure for 8 or 12 hr to 100 ppm aniline there was no difference in the maximum MetHb level, the peak aniline level in blood and fat, or the rate of aniline elimination from fat and blood.(ABSTRACT TRUNCATED AT 250 WORDS)

Adipose Tissue↗
PubMed1986

The effect of an unusual workshift on chemical toxicity. I. Studies on the exposure of rats and mice to dichloromethane.

The 10- or 12-hr workday has become increasingly popular in industry. Current occupational exposure limits are designed to protect workers on the standard 8-hr/day workshift and are not intended for use for longer workshifts. Experiments were conducted to compare the effects of a 12-hr exposure schedule to those of an 8-hr schedule on the carboxyhemoglobin (COHb) formation resulting from dichloromethane (DCM) inhalation. Rats and mice were exposed to 200, 500, or 1000 ppm DCM for 8 hr/day for 5 days or 12 hr/day for 4 days. The effect of the unusual exposure schedule on COHb levels was not significant. The metabolic pathway for the formation of COHb appeared to be saturated even at the lowest concentration of DCM. To examine the possible increase in the retention of inhaled DCM in the longer exposure schedule, single exposures for 8 and 12 hr were compared. The peak blood DCM level was dependent upon the DCM exposure concentration, but the half-life was independent of the duration of exposure and the concentration of DCM. The half-life of COHb in blood was prolonged by increasing the DCM concentration, but was not affected by the exposure period. Pyrazole treatment decreased COHb level and increased blood DCM level in rats exposed to DCM. These results suggest that the exposure limit for a chemical with a short biological half-life and readily reversible toxic effect may not need to be adjusted for a longer workshift which is in agreement with some of the mathematical models based upon the pharmacokinetics of a toxicant.

Animals↗
PubMed1983

Starvation stimulates pancreatic PGE content.

Recent evidence suggests that prostaglandins may exert a tonic inhibitory tone in the pancreatic beta cell during starvation. The effects of starvation on rat pancreatic prostaglandin E (PGE) content were studied. After 72 hrs of starvation, pancreatic PGE increased 250% above that of fed controls. Administration of streptozotocin, a selective beta-cell toxin, decreased pancreatic PGE significantly (p less than 0.005), but starvation partially reversed this trend. Thus, PGE may have a physiological role in modulating insulin secretion during starvation. It appears that both beta-cell and nonbeta-cell sources of PGE are involved in this phenomenon.

Animals↗
PubMed1983

Longitudinal chest x-ray changes in normal men.

To determine the changes on chest x-ray attributable to the aging process, we evaluated cardiovascular and pulmonary structures on two standard postero-anterior chest x-rays taken at least 10 years apart (M = 16.9 years) in 67 carefully screened healthy men initially aged 23 to 76 years. The aortic knob diameter increased in 79% of subjects. Although mean cardiothoracic ratio increased overall, only 3% of men developed a cardiothoracic ratio greater than .50, and none exceeded .51. Pulmonary abnormalities on initial chest x-ray consisted mainly of hyperinflation (27%) and increased markings (19%), both of which doubled in prevalence during follow-up. Kerley B lines and enlarged pulmonary arteries were rare initially but increased three- to five-fold. The prevalence of these findings did not differ between smokers and nonsmokers. Based on commonly accepted x-ray criteria, chronic obstructive lung disease was suggested in 15% of the initial films and 21% of the final films despite the absence of clinical or spirometric abnormalities.

Adult↗
PubMed1981

Subdural metastases from prostatic adenocarcinoma.

Adenocarcinoma of the prostate commonly metastasizes to lymph nodes and bones, with occasional visceral deposits; lesions in the brain are rare. Although leptomeningeal carcinomatosis secondary to prostatic tumor has been reported, discrete cranial dural metastases from prostatic adenocarcinoma have not been described previously. The case of a patient having a unique adenocarcinoma of the prostate with bone, lymph node, and subdural metastatic lesions is presented.

Adenocarcinoma↗
PubMed1981

Sciatin: immunocytochemical localization of a myotrophic protein in chicken neural tissues.

A mytotrophic protein (sciatin) purified from chicken sciatic nerves has "trophic" or "maintenance" effects on cultured muscle. We have elicited a specific antiserum against purified sciatin in rabbits. Using this antiserum, we investigated the distribution of sciatin in embryonic and adult chicken tissues by an unlabeled peroxidase-an-tiperoxidase method at the light microscopic level. The antiserum stained adult chicken neural tissues in situ and cultured embryonic chick neurons. Staining was intense in the cell bodies of spinal cord neurons and the axoplasm of sciatic nerves. These was reaction product seen in the outer margins of myelin sheaths that corresponded to the Schwann cell cytoplasm. Cerebral cortical neurons were weakly stained by the antiserum. No staining was apparent in oligodendrocytes or astrocytes. Nonneural tissues, such as skeletal, smooth and cardiac muscle, kidney, and liver, were also unstained by the antiserum. Cultured spinal cord neurons, cerebral cortical neurons, and sensory neurons were stained immunocytochemically by the antiserum. There was no reaction product seen in the glial cells that are usually present in neuronal cultures or cultured cells from liver, kidney, skeletal muscle, smooth muscle, and cardiac muscle. Our results thus show that the myotrophic protein is localized in neuronal perikarya and their processes in vivo as well as in vitro.

Animals↗