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Biomedical subjects

C Y Kim

Publications and source records attributed to C Y Kim.

At least 127 records · Page 7Linked to original sources

Role of vasopressin in neurocardiogenic responses to hemorrhage in conscious rats.

Vasovagal reflexes, such as hypotension and bradycardia, are induced by rapid hemorrhage and mimic neurocardiogenic reflexes in mammals. We examined the role of vasopressin in the neurocardiogenic responses to mild, rapid hemorrhage (1 mL/100 g for 30 seconds) and severe hemorrhage (1 mL/100 g body wt for 30 seconds repeated three times at 11-minute intervals) in homozygous Brattleboro and Long-Evans rats. Mild, rapid hemorrhage induced severe bradycardia and hypotension only in Long-Evans rats. Exogenous vasopressin (1.85 pmol/kg per minute for 1 hour) restored both the bradycardic and hypotensive responses in Brattleboro rats. DDAVP, a vasopressin V2-receptor agonist (0.19 pmol/kg per minute for 24 hours), did not affect the cardiovascular responses to hemorrhage in Brattleboro rats, although it maintained urine production within normal limits. However, OPC-31260 (21.6 mumol/kg IV), a vasopressin V2-receptor antagonist, attenuated both the hypotensive and bradycardic responses to hemorrhage in Long-Evans rats. A vasopressin V1-receptor antagonist attenuated bradycardia and delayed the recovery of arterial pressure after hemorrhage but did not affect the hypotension that occurred immediately after hemorrhage in Long-Evans rats. Methylatropine also attenuated both the bradycardic and hypotensive responses induced by hemorrhage, but propranolol had no effect on the cardiovascular responses to hemorrhage in Long-Evans rats. The recovery of arterial pressure after repeated hemorrhage was less adequate in Brattleboro rats than in Long-Evans rats. Our results suggest that the neurocardiogenic responses to hemorrhage, especially hypotension, may be related to vasodilation induced by a V2-receptor-mediated mechanism and by the vagal reflex, both of which are substantiated by the existence of vasopressin. The coexistence of V1- and V2-receptor mechanisms may be necessary for the hypotensive response to hemorrhage. We found that a V2-receptor antagonist attenuated the hypotension mediated by the so-called neurocardiogenic reflex.

Acute Disease↗

The brain histamine (HA) and pituitary luteinizing hormone (LH) levels in female rats anesthetized with ether on proestrus.

Levels of brain histamine (HA) and pituitary luteinizing hormone (LH) were determined in female rats anesthetized with ether in the afternoon of proestrus. The rats after 6-hr ether anesthesia had an average HA concentration higher than that of non-anesthetized rats in the hypothalamus, but not in the cortex or diencephalon. Ether-anesthetized rats also showed a higher LH level in the pituitary than that of non-anesthetized rats. These findings agree well with our previous observation of an inhibited ovulation associated with a decrease in serum LH in female rats anesthetized with ether in the afternoon of proestrus. Furthermore, it is suggested that the release of pituitary LH into the circulating blood is regulated by the level of HA in the hypothalamus.

Anesthesia↗

Distribution of selenium in human plasma detected by high performance liquid chromatography-plasma ion source mass spectrometry.

The distribution of selenium in human plasma has been investigated by high performance liquid chromatography (HPLC) connected directly to inductively coupled plasma mass spectrometry (ICP-MS). Human plasma was loaded on to a size exclusion column and eluted with 0.01 M sodium phosphate buffer (pH 7.0) at a flow rate of 0.6 ml/min. Four peaks of selenium were detected in the chromatogram. The first selenium peak was obtained in the void volume. The retention time of the third peak was in accord with that of bovine serum albumin as a standard. The forth peak was thought to be a ghost. The method was applied to identify the chemical form of selenium in blood plasma immediately after intestinal absorption. The chromatographic pattern of selenium in postprandial human plasma was compared with that in fasting plasma. The first and third peaks in the postprandial plasma sample were slightly higher than those in the fasting plasma sample. This finding suggests that absorbed selenium is associated with the high molecular weight fraction and mercaptalbumin in blood plasma.

Adult↗

Analysis of circadian variation of blood pressure and heart rate in dexamethasone-induced hypertensive rats.

We studied the effect of the chronic oral administration of dexamethasone (dexa) on arterial blood pressure (BP) in conscious rats. Special attention was paid to the effects of dexa on circadian rhythm of BP. As determined by the tail cuff-method, BP in the dexa-treated group was significantly higher than in the control group 24 h after treatment, then increased gradually, reaching a plateau on the 7th day of treatment. At that time, the difference in BP between the two groups was approximately 30 mmHg. When monitored directly and continuously on day 10, mean arterial pressure (MAP) in the dexa-treated group exceeded that of the control group by approximately 15 mmHg throughout the monitoring period. Thus, the circadian rhythm of MAP was sustained in the dexa-treated group, which was in contrast to the previously reported elimination of circadian rhythm in humans. In addition, the increase in BP may have been overestimated by tail-cuff plethysmography, possibly owing to a hightended cardiovascular reactivity to environmental stimuli in dexa-treated animals.

Administration, Oral↗

Adrenal paragonimiasis simulating adrenal tumor--a case report.

We describe a case of adrenal paragonimiasis with its computed tomographic and ultrasonographic findings. Computed tomogram showed a well enhancing oval mass at right adrenal gland and ultrasonogram showed a dumbbell-shaped hyperechoic mass saddling on the top of the right kidney. Surgical specimen was multicystic mass filled with creamy material.

Adrenal Gland Diseases↗

Characterization of focal hepatic tumors. Value of two-phase scanning with spiral computed tomography.

BACKGROUND: Spiral computed tomography (CT) allows imaging of the liver during the peak contrast material levels due to the capability of fast data acquisition. The objective of this study was to evaluate the usefulness of two-phase spiral CT in the differential diagnosis of focal hepatic tumors. METHODS: One hundred two patients who had hepatic tumors (211 nodules; 149 hepatocellular carcinomas [HCCs], 36 metastases, and 26 hemangiomas) underwent two-phase spiral CT with 10-mm collimation at 10 mm/second table speed and 120 mL of contrast material injected at the rate of 3 mL/second. Computed tomography images of the hepatic arterial phase and late (equilibrium) phase were obtained at 35-second and 180-second delays, respectively. The enhancement patterns of tumors were divided into six types and were compared with the attenuation of surrounding liver parenchyma: totally high, peripherally high, centrally high, mixed, iso, and low. RESULTS: The common enhancement patterns of HCC in two-phase spiral CT were totally high in the arterial phase and low (n = 63, 42%) or iso (n = 28, 19%) in the late phase. Metastasis showed peripherally nonnodular high attenuation (n = 9, 25%) or low attenuation (n = 9, 25%) in the arterial phase and low attenuation in the late phase, followed by totally high attenuation in the arterial phase and iso in the late phase (n = 6, 17%). Hemangiomas showed totally or peripherally nodular enhancement in the arterial and late phases (n = 23, 89%). In distinguishing hemangiomas from malignant tumors, totally high or peripherally nodular high attenuation in the late phase was the most useful contrast enhancement pattern (96% of hemangioma vs. 0% of malignant tumors). In distinguishing HCCs from metastases, a combination of contrast enhancement pattern of totally high attenuation in the arterial phase and low in the late phase was the most useful contrast enhancement pattern (42% of HCCs vs. 0% of metastases). The predictability of differentiation between hemangiomas and malignant tumors and between HCCs and metastases was 99% and 90% with spiral CT, respectively. CONCLUSIONS: Two-phase spiral CT is useful in the differential diagnosis of focal hepatic tumors with evaluation of contrast enhancement patterns.

Adult↗

Ontogenetic development of histamine receptor subtypes in rat brain demonstrated by quantitative autoradiography.

The postnatal ontogenetic development of the histamine receptor subtypes was studied in rat brain by quantitative receptor autoradiography with highly sensitive imaging plates. H1 receptor binding sites labeled with [3H]pyrilamine were detected on postnatal day 2 (P2) and increased very slowly until P9, and then rapidly reaching the adult levels in the hypothalamus, hippocampus, and amygdala by P16. The densities of H1 receptor binding sites in the cortex, striatum, thalamus, and substantia nigra were relatively low during development. H3 receptor binding sites labeled with [3H](R) alpha-methylhistamine were not detectable until P9. On P9, their density was higher in the substantia nigra than in other regions. Subsequently, H3 receptor binding increased, reaching the adult levels in the substantia nigra on P16 and in the other regions on P23. The histamine concentration was initially very high, but decreased to the adult level by P16. On the contrary, the activity of L-histidine decarboxylase of whole brain tissue was low on P5, and increased markedly from P16 to P23, to the adult level on P30. Administration of (S) alpha-fluoromethylhistidine (FMH), a specific inhibitor of L-histidine decarboxylase (HDC), significantly decreased both the HDC activity and histamine concentration during postnatal development. FMH treatment did not change H1 receptor binding in any brain region, but significantly increased H3 receptors in the substantia nigra and striatum on P23. Unilateral injection of 6-hydroxydopamine into the striatum on P2 resulted in up-regulation of H3 receptor binding sites in the dorsomedial (11%) and dorsolateral (18%) regions of the striatum and substantia nigra (31%) on P23, but no change in the H3 receptor density in the nucleus accumbens or frontal cortex on P11 and P23. These results demonstrate that the developmental patterns of H1 and H3 receptors are heterogeneous and independent of each other. There are marked mismatches of presynaptic and postsynaptic markers of the histaminergic neuron system as in other aminergic systems.

Aging↗

Effects of buthionine sulfoximine (BSO) on mercury distribution after Hg(o) exposure.

Effects of buthionine sulfoximine (BSO), a glutathione (GSH) depletor, on mercury (Hg) distribution were studied after mercury vapor (Hg(o)) exposure (3.2 mg/m3) in mice. BSO (1.6 g/kg, i.p.) significantly decreased the GSH levels in the liver, kidney and lung. Pretreatment with BSO increased Hg concentrations in the lung, liver and plasma, but decreased Hg concentration in the kidney. These findings indicate that GSH functions as a determinant in the changes of Hg distribution after Hg(o) exposure. Possible causes of the alterations in Hg distribution are discussed, including the anticipated enhancement in the Hg(o) oxidation process in the tissues with decreased GSH levels as well as the transportation of Hg2+ derived from oxidation of Hg(o). Concentrations of thiobarbituric acid reactive substances (TBARS) were determined as an indicator of oxidative damage, but the increase in TBARS was not detected in any tissue examined.

Analysis of Variance↗

Adult Hirschsprung's disease. Results of the Duhamel's procedure.

Eleven patients with adult Hirschsprung's disease were treated at Seoul National University Hospital (SNUH, 8 cases) and Chosun University Hospital (CUH, 3 cases) between 1985 and 1992. Of the 11 patients, seven were male. The age of the patients ranged from 11 to 30 years, and all presented with chronic constipation and recurrent faecal impactions that required periodic enemas and laxatives. The Duhamel's operation, as a single or staged procedure, was performed in all patients. Levels of aganglionosis in 9 patients were confined to the rectosigmoid colon (82%). There were three major post-operative complications. Two patients developed fistula-in-ano at the anastomotic site, and one patient developed ileus. However, these complications resolved with conservative management. The longterm results were excellent except for one patient who developed impotence. The mean frequency of bowel movements was usually once or twice a day without the aid of other treatments. Our results indicate that Duhamel's operation is a highly acceptable procedure in the management of adult Hirschsprung's disease.

Adolescent↗

Inhibition of gamma-glutamyltranspeptidase decreases renal deposition of mercury after mercury vapor exposure.

The alteration of renal deposition of mercury (Hg) after mercury vapor (Hg0) exposure was studied in mice pretreated with acivicin, a potent and irreversible inhibitor of gamma-glutamyltranspeptidase (GGT). Pretreatment with acivicin decreased renal Hg concentration by about 60% and significantly increased Hg concentration in the urine compared with the non-treated group. The results suggest that renal deposition of Hg after Hg0 exposure depends on renal GGT, which plays an important role in the uptake of GSH or GSH conjugates filtered through the glomeruli. It seems that the mechanism of renal Hg deposition after Hg0 exposure is similar to that after exposure to ionic Hg: a GGT-mediated incorporation of an Hg-GSH complex into renal tubular cells. The acivicin pretreatment after Hg0 exposure did not affect Hg concentrations in the liver and erythrocytes.

Administration, Inhalation↗

Preliminary experiences with intraoperative radiation therapy (IORT) for the treatment of brain tumors.

Ten brain tumor patients underwent wide resection of the tumor followed by Intraoperative Radiation Therapy (IORT) at the first surgery or at the second salvage surgery after failure of conventional external beam irradiation. Two patients(1 meningioma, 1 glioblastoma multiforme) were treated at the first surgery and 8 patients(3 anaplastic astrocytoma, 3 glioblastoma multiforme, 1 meningioma, 1 gliosarcoma) were treated after salvage surgery. The IORT doses were ranged from 15-25 Gy depending on the tumor volume and previous radiation therapy. The neurological status(Karnofsky performance status) was improved in 4 cases, not changed in 6 cases after IORT. There were several complications after IORT; radiation necrosis, communicating hydrocephalus, wound infection, and abnormal CT findings such as diffuse low density area in an around operation site. The radiation necrosis was confirmed by operation in a recurrent meningioma patient 12 months after IORT. At follow-up, ranging from 1 to 16 months, there was no deaths. Based on our limited experiences, the IORT might be one of the adjuvant therapeutic modalities especially for the malignant brain tumors and unresectable huge meningioma.

Adult↗

[Interleukin-8 gene expression in the human colon epithelial cell line, HT-29, exposed to Entamoeba histolytica].

The protozoan parasite, Entamoeba histolytica, is one of major causative agents of intestinal disease all over the world. In acute experimental infection, the early host response to E. histolytica is characterized by an infiltration of neutrophils. However, the chemotactic signal for this response is not well known. Based on the finding that human epithelial cells produce the potent neutrophil chemoattractant and activator, interleukin-8 (IL-8), IL-8 gene expression was examined thoroughly in human colon epithelial cells exposed to E. histolytica trophozoites. Cellular RNAs were extracted from HT-29 or Caco-2 human colon epithelial cells exposed to E. histolytica trophozoites for 30 minutes, 1 and 3 hours. IL-8 mRNA transcripts were measured by reverse transcriptional polymerase chain reaction (RT-PCR) using synthetic standard RNA. The number of IL-8 mRNA molecules increased from 30 minutes to 3 hours of exposure period, reaching 3.1 x 10(7) molecules/micrograms of total RNA. Expression pattern of IL-8 mRNA transcripts was parallel to the amounts of IL-8 protein measured by enzyme-linked immunosorbent assay (ELISA). Lysates of E. histolytica also induced expression of mRNA for IL-8 in colon epithelial cells. These results suggest that acute inflammatory reaction by E. histolytica may be initially triggered by proinflammatory cytokines such as IL-8 secreted from epithelial cells of the colon.

Animals↗

Combination chemotherapy with cyclophosphamide, vincristine, cisplatin and etoposide (COPE) combined with radiotherapy for small cell lung cancer.

OBJECTIVES: Small cell lung cancer is sensitive to chemotherapy and radiotherapy. Nevertheless, responses are still short-lived and apparent cure remains for only limited disease patients. METHODS: We combined cyclophosphamide (750 mg/m2 by intravenous infusion at first day) vincristine (2 mg intravenously at third day), cisplatin (20 mg/m2 intravenously for 3 days), and etoposide (100 mg/m2 intravenously for 3 days) with radiotherapy (total 300cGy over 4 weeks in 17 fractions) and treated 39 patients with small cell lung cancer who had received no prior systemic chemotherapy and radiotherapy. RESULTS: 1) Thirty-nine patients (limited disease: 17 patients, extensive disease 22 patients) were treated and 35 patients were evaluable for response. Overall response rate was 82.8% (complete response 28.6%, partial response 54.2%). 2) The median survival was 52 weeks for all patients and 58 weeks for limited disease and 45 weeks for extensive disease. There was no statically significant survival difference between the two patient groups. The median relapse-free survival time was 48 weeks. 3) Overall, treatment was well tolerated, with granulocytopenia being the most frequent toxicity. CONCLUSIONS: Combination chemotherapy with COPE regimen combined with radiation therapy was effective as a first line therapy for SCLC.

Adult↗

Frequent reactivations of anti-HBe-positive chronic hepatitis B in patients with no demonstrable HBV DNA in serum by polymerase chain reaction.

OBJECTIVES: The present study was conducted to evaluate the prognostic significance of the absence of serum HBV DNA by polymerase chain reaction (PCR) after spontaneous HBeAg/anti-HBe seroconversion and concurrent or subsequent biochemical remission. METHODS: We prospectively investigated the reactivation rates in 28 chronic hepatitis B patients according to the positive or negative serum HBV DNA test by PCR. The sera drawn at a mean period of 4.4 months after normalization of alanine aminotransferase (ALT) were analyzed by PCR-Southern blot hybridization to detect HBV DNA, and then the patients were divided into two groups according to the presence (n = 14) or absence (n = 14) of HBV DNA in the sera. RESULTS: The cumulative reactivation rates in patients with HBV DNA in sera were 43%, 57%, 57%, 57% and 57% at the end of 1st, 2nd, 3rd, 4th and 5th year after normalization of ALT, respectively, and those in patients without demonstrable HBV DNA were 50%, 66%, 74%, 74% and 83%, respectively; thus, the difference in the cumulative reactivation rates between patients with and without serum HBV DNA was not statistically significant (p = 0.79), and irrespective of the status of HBV DNA in sera by PCR, reactivations occurred very rarely after 2 years of a sustained remission. CONCLUSIONS: We conclude that the seroconversion to anti-HBe accompanied by disappearance of serum HBV DNA even by PCR does not necessarily suggest a sustained remission of chronic hepatitis B.

Adult↗

Association of the core clustering mutations (codon 21-34) and the severity of chronic hepatitis B in Korean patients.

OBJECTIVES: There are regions in the core gene of hepatitis B virus (HBV) where missense mutations are clustered, and mutations in that region are related to severe liver disease. However, there were some differences of the major regions for mutation clustering among ethnic groups. To explore the phenomenon of clustering mutations in Korean patients with chronic HBV infection and to elucidate the correlation between clustering mutation region of the core gene and the severity of liver damage, we analyzed the precore/core gene sequence of HBV in the sera from fifteen chronic hepatitis B (CH-B) patients. METHODS: We analysed the HBV precore and core sequences in the sera obtained from fifteen patients (14 males and 1 female, mean age 30.0 years) with biopsy-proven CH-B. The patients were divided into two groups according to the pathological severity of CH-B; namely, group I consisted of 8 patients with chronic persistent hepatitis (CPH), and group II included 7 patients with chronic active hepatitis (CAH). After extraction of HBV DNA from each serum by proteinase K and phenol-chloroform solution, the entire precore and core region of HBV was amplified by PCR, and then the PCR products were subjected to direct sequencing using thermostable DNA polymerase. Fisher's exact test and Mann-Whitney U test were used for statistical analysis. RESULTS: A total of 181 nucleotide substitutions were found in the HBV core gene from the 15 CH-B patients, of which 23 were missense and 158 were silent. The nucleotide and amino acid substitution rates were not significantly different between the two groups (p > 0.05). Two mutational hot spots (MHS), codons 21-34 (MHS1) and codons 85-100 (MHS2), were found in the deduced amino acid alignment of the core gene. The alteration rate of amino acid residue in these regions were 2.857 x 10(-2) and 5.000 x 10(-2), respectively. Of 8 CPH patients, 5 showed missense mutations only in MHS2. In comparison, of 7 CAH patients, 3 showed them both in MHS1 and MHS2, 1 only in MHS1, and 1 only in MHS2; thus, missense mutation in MHS1 was exclusively found in patient with CAH. CONCLUSIONS: There were two mutation clusterings in the core region of adr subtype of HBV from Korean CH-B patients. Mutations in MHS1 (codon 21-34), but not in MHS2 (codon 85-100), are more likely to be related to the severity of CH-B. A longitudinal study using sequential samples is warranted to further clarify the role of MHS1 in the pathogenesis of more severe CH-B.

Adult↗