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Biomedical subjects

C Y Kim

Publications and source records attributed to C Y Kim.

At least 19 recordsLinked to original sources
PubMed1992

Compositional dependence of calcium phosphate layer formation in fluoride Bioglasses.

Bioglasses form a double layer composed of apatite and a silica-rich layer when placed in a simulated physiological solution as well as in living tissue [A.E. Clark, C.G. Pantano, and L. L. Hench, "Auger spectroscopic analysis of bioglass corrosion films," J. Am. Ceram. Soc., 59(1-2), 37-39 (1976).]. In the present work, the mechanisms of the calcium phosphate layer and the silica-rich layer formation of fluoride Bioglasses in Tris-buffer solution are studied as a function of the SiO2 content. Fourier Transform Infrared Reflection Spectroscopy (FTIRS) is used to investigate the mechanism of formation of calcium phosphate and silica-rich layers on the glass surface. Ion concentration in reacted solution and elemental depth profiles are obtained by Induced Coupled Plasma Atomic Emission Spectrometry (ICP) and Auger Electron Spectroscopy (AES), respectively. Si--O bonds with one nonbridging oxygen and Si--O--Si bonds form at the early stage of reaction. Strong phosphorus ion uptake occurs when an amorphous calcium phosphate layer crystallizes. Glasses with high silica content (conventional glass) form the silica-rich layer first followed by a calcium phosphate layer on top. However, glasses with low silica content (invert glass) form both layers simultaneously. The rate of apatite formation decreases with increasing SiO2 content, especially in the region of conventional glass compositions. Ion release rates decreases as SiO2 content increases, with a significant change occurring at the compositional boundary between invert and conventional glasses.

Biocompatible Materials↗
PubMed1992

Differential expression of protein kinase C epsilon protein in lung cancer cell lines by ionising radiation.

The effect of ionising radiation on the regulation of gene and protein expression is complex. This study focuses on the translational regulational of the epsilon isoform of protein kinase C by ionising radiation. We found that protein kinase C epsilon is rapidly increased in the human lung adenocarcinoma cell line A549 following irradiation. Western blots showed increased accumulation of this protein at doses as low as 75 cGy after 15 min post irradiation. Maximal induction (11-fold over unirradiated cells) of PKC epsilon occurred at 150 cGy within 1 h after treatment by X-rays in A549 cells. The increased levels of PKC epsilon protein after X-rays does not require de novo protein or RNA synthesis, suggesting that this increase is post-translationally controlled. In contrast to A549 cells PKC epsilon levels in the large cell lung carcinoma cell line NCI H661 were not induced by radiation. In the small cell lung carcinoma cell line NCI N417, PKC epsilon was also not induced but a higher molecular weight PKC epsilon protein, suggestive of phosphorylation, appeared at 2 h after irradiation. The variation in induction or phosphorylation of PKC epsilon by ionising radiation in the cell lines tested in this study suggested that no clear correlation existed between intrinsic radiation sensitivity and PKC epsilon induction. To determine whether PKC epsilon does play a role in cell survival to irradiation, we used the protein kinase inhibitor staurosporin to decrease PKC activity and found that staurosporin sensitised cells to killing by ionising radiation. Pulsed field gel electrophoresis, however, indicated that DNA double-strand break repair was not decreased, suggesting that PKC epsilon is modifying the fidelity of rejoining and not the overall magnitude of repair. The regulation of PKC by ionising radiation will be discussed with respect to the biological consequences of gene induction by DNA damage agents.

Adenocarcinoma↗
PubMed1992

Therapeutic effect of transcatheter oily chemoembolization therapy for encapsulated nodular hepatocellular carcinoma: CT and pathologic findings.

An emulsion of iodized oil and doxorubicin hydrochloride was intraarterially injected in 27 patients with encapsulated single nodular hepatocellular carcinoma (HCC). Computed tomography (CT) was performed 1-3 weeks after injection, and the lesions were resected 1-4 weeks thereafter. The percentages of tumor necrosis were evaluated in cut surfaces of resected specimens and were compared with the findings at iodized-oil CT. Six tumors with complete intratumor retention of iodized oil had 98% necrosis, and 21 tumors with incomplete retention had 64% necrosis. Two tumors with complete retention of iodized oil in the surrounding liver had 100% necrosis, while 16 tumors with partial retention and nine tumors without retention of iodized oil in surrounding liver had 74% and 62% necrosis, respectively. Complete retention of iodized oil in the tumor and surrounding liver demonstrated the best therapeutic effects. Evaluation of the pattern and distribution of iodized oil in the tumor and surrounding liver with iodized-oil CT is useful in the assessment of the therapeutic effects of transcatheter arterial embolization in encapsulated nodular HCCs.

Carcinoma, Hepatocellular↗
PubMed1991

Specificities of serum alpha-fetoprotein in HBsAg+ and HBsAg- patients in the diagnosis of hepatocellular carcinoma.

Serum alpha-fetoprotein level is often elevated in patients with chronic liver disease and patients with hepatocellular carcinoma. One of the most difficult problems frequently encountered in practice is differentiating hepatocellular carcinoma from chronic liver disease. This study investigated the specificity and predictive value positive of serum alpha-fetoprotein at various levels in the diagnosis of hepatocellular carcinoma, using 54 patients with histologically proven hepatocellular carcinoma and 200 patients with chronic liver disease (40 patients with chronic active hepatitis and 160 patients with cirrhosis) as nontumor controls. Among 254 patients, 170 (66.9%) were HBsAg+. A wide range of overlap (from 0 to 6,400 ng/ml) in the distribution of serum alpha-fetoprotein levels between hepatocellular carcinoma and chronic liver disease patients was observed mainly among HBsAg+ patients. In contrast, the overlapping range of serum alpha-fetoprotein levels between HBsAg- patients with hepatocellular carcinoma and chronic liver disease was remarkably narrow (from 0 to 200 ng/ml). Therefore the specificity and predictive value positive of alpha-fetoprotein at a given level were significantly lower in HBsAg+ than in HBsAg- patients, especially when alpha-fetoprotein was between 25 and 200 ng/ml. The specificities of alpha-fetoprotein at 200 ng/ml and 400 ng/ml in HBsAg+ patients were 79.8% and 91.5%, respectively, whereas these specificities were both 100% in HBsAg- patients. The predictive values positive at 200 ng/ml and 400 ng/ml in HBsAg+ patients were 53.6% and 72.5%, respectively, in contrast to 100% at both levels in HBsAg- patients. The serum alpha-fetoprotein level, which showed a predictive value positive of 95% in HBsAg+ hepatocellular carcinoma patients, was 3,200 ng/ml, whereas that in HBsAg- hepatocellular carcinoma patients, was 200 ng/ml. We conclude that serum HBsAg status should be considered when serum alpha-fetoprotein is measured as an independent test to diagnose hepatocellular carcinoma, and suggest that regular serum alpha-fetoprotein determination may be more useful in HBsAg- patients with chronic liver disease for the early diagnosis of hepatocellular carcinoma than in HBsAg+ patients.

Carcinoma, Hepatocellular↗
PubMed1991

Intraoperative sonography of hepatocellular carcinoma: detection of lesions and validity in surgical resection.

Eighty-six hepatocellular carcinomas (HCCs) in 67 patients were examined by intraoperative sonography. Sensitivity for detecting tumors with intraoperative sonography was compared with sonography, computed tomography (CT), hepatic angiography, and CT after intraarterial injection of iodized poppy-seed oil (Lipiodol-CT). The overall sensitivities were 76% with sonography, 86% with CT, 89% with angiography, 96% with Lipiodol-CT, and 98% with intraoperative sonography. The differences in sensitivity between intraoperative sonography and sonography (p less than 0.01), CT (p less than 0.01), and angiography (p less than 0.05) were significant. In 35 lesions smaller than 2 cm, the sensitivities of Lipiodol-CT and intraoperative sonography were high (91 and 94%, respectively). In operating field, tumors were invisible in 36 (42%) and nonpalpable in 31 of 86 cases (36%). In 35 tumors smaller than 2 cm, invisible tumors were 66% and nonpalpable tumors were 63%. However, 84 of 86 cases (98%) could be localized with intraoperative sonography. These results suggest that intraoperative sonography is the final diagnostic imaging procedure before surgical resection of tumors and in cases of invisible and nonpalpable tumors in the operating field, this procedure is mandatory to improve surgical results.

Carcinoma, Hepatocellular↗
PubMed1991

Atypical clinical manifestations of amebic colitis.

Amebic colitis is a disease revealing diverse clinical manifestations and endoscopic gross features and often confused with other types of colitis. In case of misdiagnosis as an idiopathic inflammatory bowel disease or delayed recognition of intestinal amebiasis, an undesirable outcome may occur resulting from erroneous administration of steroids or delayed antiamebic treatment. To demonstrate the pitfalls in the diagnosis and treatment of intestinal amebiasis, 3 cases of amebic colitis with atypical clinical manifestations are presented in this paper. In conclusion, despite the low sensitivities of routine stool examination for parasite and histopathologic confirmation in biopsy specimen, every effort must be made to find amebic trophozoites either in fresh stool or biopsy specimens for prompt and correct diagnosis of amebic colitis when we manage patients with chronic intestinal ulcerations, even though their clinical course and endoscopic findings are not typical of amebiasis. Moreover, following initial successful anti-amebic therapy, more careful clinical, endoscopical, and parasitological follow-up should be done for the early detection of recurrence.

Adult↗
PubMed1991

Temporal changes in the clinical type or diagnosis of Behçet's colitis in patients with aphthoid or punched-out colonic ulcerations.

The intestinal lesion of Behçet's colitis shows aphthoid or punched-out ulceration. However, the diagnosis of Behçet's colitis should be based on the presence of other stigmata of Behçet's syndrome, since these morphological characteristics are not pathognomonic by themselves. Furthermore, the stigmata of Behçet's syndrome could appear simultaneously or separately with intervals of several months to years. Besides, when a physician first meets patients with intestinal ulcerations of aphthoid or punched-out shape, if they do not have any stigma of Behçet's syndrome, the physician has some difficulty in making a diagnosis of Behçet's colitis. The purpose of this retrospective study was to investigate the followings: 1) The upgrade in clinical type of Behçet's colitis with the advance of time. 2) What portion of the patients with aphthoid or punched-out ulcerations, but without any other clinical feature of Behçet's syndrome, could be diagnosed as Behçet's colitis with the advance of time? During the mean follow-up period of 38.2 months, 4 (22.2%) out of 18 patients with Behçet's colitis upgraded their clinical types. In the nonspecific ileocolitis group, who had no major stigma of Behçet's syndrome on their initial visit, 3 (30%) out of 10 patients were subsequently diagnosed as Behçet's colitis during the mean follow-up period of 33.3 months. From these results, we could conclude that in possible or suspicious cases of Behçet's colitis, a more confident diagnosis could be made by close observations for new developments of major stigma of Behçet's syndrome. Even in cases of nonspecific ileocolitis, the diagnosis of Behçet's colitis could be made in a significant number of cases as time goes by.

Adolescent↗
PubMed1991

A reconstructed cohort study on the hepatitis B virus infection as a risk factor of liver cancer in Korea.

A stable cohort (n = 369,725) was reconstructed to test the association of hepatitis B virus (HBV) infection with subsequent occurrence of liver cancer in a healthy Korean population. The cohort consisted of male beneficiaries of the Korea Medical Insurance Corporation over 30 years of age, living nationwide. The HBV infection was tested by the reversed passive hemagglutination method for the HBsAg and by the passive hemagglutination method for the anti-HBs at the time of recruitment in 1984. Admissions due to liver diseases were identified through a computerized system for reimbursements on medical insurance claims from January 1, 1985 to December 31, 1987. For a more valid estimate of incidence, a sample survey was carried out, obtaining correction coefficients against misclassification of the diagnosis, as well as those for duplicate claims in a year. The incidence rate of liver cancer steadily increased with age (kappa 2 TREND = 51.1, df = 1, p = 0.00).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1990

Identification of integrated hepatitis B virus DNA sequences in human hepatocellular carcinomas in Korea.

The rate of HBV DNA integration into the genome of hepatocellular carcinoma (HCC) cells varies greatly among HCC tissues from different geographical districts. Because of the potential etiological significance of identifying HBV DNA integration in HCC tissues from Korea, we investigated 13 aseptically obtained HCC surgical specimens by Southern blot analysis. Among 13 HCCs, eight (61.5%) contained integrated HBV DNA. Of eight HBsAg-positive patients, six (75%) had integrated HBV DNA in their HCCs while two (40%) out of five HBsAg-negative patients had integrated HBV DNA. Those two HBsAg-negative patients with integrated HBV DNA were all anti-HBs-positive. However, it was not demonstrated in the patient without any HBV serological markers. These findings highly suggest a prominent etiologic role of HBV in the development of HCC. On the other hand, it also strongly favors a multifactorial etiology of human HCC in korea.

Adult↗
PubMed1979

Effects of the second (ethanol) extract of ginseng on the cardiovascular dynamics of dogs during halothane anesthesia.

An electromagnetic flowmeter probe was chronically implanted around the ascending aorta in a group of dogs. Subsequently, ten dogs were lightly anesthetized with halothane (0.75%), and a second (ethanol) extract of ginseng (40 mg/kg) was administered intravenously. Five dogs were anesthetized without the administration of ginseng. Eleven cardiovascular variables including cardiac output, stroke volume, heart rate, mean arterial pressure, pulse pressure, central venous pressure, total peripheral resistance, pH, PaCO2, PaO2, and base deficit were compared for two hours. The heart rate and mean arterial pressure were significantly decreased following ginseng. There were no other meaningful changes in either group.

Anesthesia, Inhalation↗
PubMed1979

Effects of the third (aqueous) extract of ginseng on the cardiovascular dynamics of dogs during halothane anesthesia.

An electromagnetic flowmeter probe was chronically implanted around the ascending aorta in a group of dogs. Subsequently, ten dogs were lightly anesthetized with halothane (0.75%) and the third (aqueous) extract of ginseng (40 mg/kg) was administered intravenously. Five dogs were anesthetized without the administration of ginseng. Eleven cardiovascular variables including cardiac output, stroke volume, heart rate, mean arterial pressure, pulse pressure, central venous pressure, total peripheral resistance, pH, PaCO2, PaO2, and base deficit were compared. The cardiac output, stroke volume, and central venous pressure were decreased significantly, while total peripheral resistance was increased significantly following ginseng.

Anesthesia, Inhalation↗
PubMed1979

Can an extract of deer antlers alter cardiovascular dynamics?

Ten (10) dogs were maintained under 0.75% halothane anesthesia while 11 cardiovascular parameters were studied before and following intravenous administration of an extract prepared from deer antlers. The eleven variables including cardiac output, stroke volume, heart rate, mean arterial pressure, pulse pressure, central venous pressure, total peripheral resistance, pH, PaCO2, PaO2 and base line deficit were studied. Stroke volume was consistently elevated during the period of observation and significantly elevated at two time intervals. Other values were not altered significantly. Extract from deer antlers does not appear to have a great acute effect on the cardiovascular system of this animal model.

Animals↗
PubMed1978

Effects of the first (ether) extract of ginseng on the cardiovascular dynamics of dogs during halothane anesthesia.

An electromagnetic flowmeter probe was chronically implanted around the ascending aorta in ten dogs. Subsequently, these animals were maintained under halothane (0.75%) anesthesia during the intravenous administration of an ether extract (40 mg/kg) of ginseng. Five other dogs were anesthetized without injecting ginseng. Eleven cardiovascular variables including cardiac output, stroke volume, heart rate, mean arterial pressure, pulse pressure, central venous pressure, total peripheral resistance, pH, PaCO2, PaO2 and base deficit were compared during the ensuing 120 minutes. The heart rate was significantly decreased and central venous pressure increased significantly following ginseng. There were no other meaningful changes in either group.

Anesthesia↗
PubMed1978

Radiologic manifestations of epidemic haemorrhagic fever with renal syndrome.

Epidemic haemorrhagic fever is a viral disease characterized by acute febrile onset followed by profound renal dysfunction. The endemic areas are widespread throughout the Eurasian continent and the Japanese islands. The patient with EHF usually seeks medical care as an emergency for an "acute abdomen". Consequently the X-ray examination becomes an essential part of the clinical study. We analysed the plain abdomen and chest films of 62 patients with this disease. The radiologic manifestations represented diffuse capillary damage with resultant oedema and haemorrhage, particularly in the retro-peritoneal space. Abnormal findings were seen in 94% of the patients on the plain abdomen, and in 63% on the chest film. The most significant finding was obliteration and blurring of anatomical detail in both intra- and retro-peritoneal cavities and renal enlargement. We believe that simultaneous presence of oedema and effusion in both intra- and retro-peritoneal cavities along with renal enlargement is in practice pathognomic of EHF. Obliteration of the renal outline and cardiomegaly with overt lung oedema was associated with the most severe renal dysfunction.

Adolescent↗
PubMed1977

Studies on avian erythrocyte metabolism. VII. Effect of inositol pentaphosphate and other organic phosphates on oxygen affinity of the embryonic and adult-type hemoglobins of the turkey embryo.

The effects of 2, 3-diphosphoglyceric acid (2, 3-DPG), adenosine triphosphate (ATP), inositol tetraphosphate (ITP), inositol pentaphosphate (IPP), and inositol hexaphosphate (IHP) on oxygen affinity of whole stripped hemoglobin (WSH), hemoglobin H (Hb-H; hatching hemoglobin), hemoglobin A (Hb-A), and hemoglobin D (Hb-D) isolated from erythrocytes (RBC) of the 25-day turkey embryo have been studied. The order of the decrease in oxygen affinity induced by these organic phosphates, at molar ratios of phosphate compound to hemoglobin (tetramer) between 2 and 4, is 2, 3-DPG less than ATP less than ITP less than IPP less than IHP. 2, 3-DPG shows a slightly greater effect on reducing oxygen affinity of Hb-H than on either adult-type hemoglobin. The effect of IPP upon lowering the oxygen affinity of either WSH, Hb-H, Hb-A, or Hb-D is approximately 20 percent less than IHP. The effects of the various organic phosphates upon the Hill constant, n, of these purified hemoglobins is variable but appears to reach a maximum when the molar ratio of organic phosphate to hemoglobin (tetramer) is 2 or greater. None of the physiologically occurring organic phosphates has a significant preferential interaction with any specific hemoglobin. These experiments strengthen and support our earlier conclusion, that the changes in whole blood oxygen affinity which occur during avian development result from the changes in composition of the intraerythrocytic organic phosphates.

Adenosine Diphosphate↗
PubMed1976

Studies on avian erythrocyte metabolism. 5. Relationship between the major phosphorylated metabolic intermediates and while blood oxygen affinity in embryols and poults of the domestic turkey (Meleagris gallopavo).

The changes in organic phosphates of turkey erythrocytes (RBC) have been determined in relation to the changes in oxygen affinity of whole blood during growth of the embryo and poult. On a molar basis, 2,3 diphosphoglyceric acid (2,3-DPG) is the predominant organic phosphate of erythrocytes from turkey embryos during the last week of incubation. However, on the basis of relative % phosphate, 2,3-DPG is the major organic phosphate of the erythrocytes from turkey embryos on day 23 and 25 of incubation only. With the exception of day 23 and 25 incubation, adenosine triphosphate (ATP) represents the major organic phosphate of the erythrocytes of the turkey embryo and poult during the last week of embryonic development and through the first 29 days after hatching. The whole blood P50 during the last week of incubation and the first 8 days after hatching correlates best with the amount of ATP in the erythrocytes. The effects of inositol pentaphosphate on P50 of the whole blood is much more gradual and appears to become of major influence after 2-3 weeks post-hatching.

Adenosine Diphosphate↗