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Biomedical subjects

Y I Kim

Publications and source records attributed to Y I Kim.

At least 19 recordsLinked to original sources
PubMed1992

Chromogranin-A expression in gastric and colon cancer tissues.

UNLABELLED: We studied the expression of chromogranin A (CgA) in human gastric (n = 17) and colorectal (n = 18) adenocarcinomas by nucleic acid hybridization and immunohistochemical analyses using a specific monoclonal antibody (MAb) to human chromogranin A (CgA). Some corresponding adjacent non-malignant mucosal tissues were also examined. RESULTS: (1) Northern blotting: of 3 normal gastric mucosas examined, 2 (67%) had an easily detected signal for expression of CgA. Only one of 14 gastric carcinomas (7%) and one of 18 colorectal carcinomas (6%) had easily detected RNA signals. (2) Immunohistochemical staining: all non-malignant samples of gastric and colonic mucosa contained CgA-positive neuroendocrine (NE) cells. Two of 17 (12%) gastric adenocarcinomas, and 3 of 18 (17%) of colorectal adenocarcinomas contained CgA-positive tumor cells. Interestingly, the positive cases detected by immunohistochemistry included both cases detected by Northern blotting. Of the 5 cases detected by immunohistochemistry, 2 gastric cancers and 1 rectal carcinoma contained many diffusely scattered positive cells, occurring singly or in small clusters, while 2 colorectal carcinomas contained only occasional single CgA-positive tumor cells. In one of the positive gastric cases, a well-differentiated adenocarcinoma arising in a tubular adenoma, both the adenomatous and the carcinomatous elements contained positively staining cells. Our specific assays for CgA indicate that (1) a NE cell component, either diffusely scattered or occasional, occurs in about 15% of gastric and colorectal tumors; (2) there is no correlation between the presence of NE cells and degree of tumor differentiation; and (3) because only a minority of the tumor cells in positive cases stain for CgA, immunohistochemistry is a more sensitive method than Northern blotting.

APUD Cells↗
PubMed1992

Lambert-Eaton syndrome: antigen-antibody interaction and calcium current inhibition in chromaffin cells.

Plasma and IgG obtained from 10 Lambert-Eaton myasthenic syndrome (LES) patients (5 with carcinoma, 5 without associated cancer), 6 healthy subjects, and 1 patient with small-cell lung cancer (SCLC) were examined in their ability to recognize chromaffin cell antigens on Western blots. The pattern of antigen recognition was compared with the magnitude of inhibition of voltage-dependent calcium and sodium currents recorded with the patch-clamp technique from chromaffin cells. Eight of the 11 patients with LES and/or SCLC recognized plasma membrane proteins and 9 of the patients' IgG interacted with cytoplasmic antigens with no apparent pattern of antigen recognition between patients. Also, there was no obvious band pattern distinguishing patients with LES from those with LES and concurrent SCLC. Eighty percent of the LES patients' antibodies were capable of reducing the calcium current (ICa) in chromaffin cells. One of the novel findings of this study is that 30% of the patients had produced antibodies which were able to inhibit both calcium and sodium currents (INa). The heterogeneous response of the IgG on the Western blots does not appear to correlate with the efficacy of reducing the inward currents.

Antigen-Antibody Reactions↗
PubMed1992

Cavernous lymphangioma of prostate: radiological findings.

A case of a cavernous lymphangioma of the prostate in a 29-year-old man is reported. The mass was hyperechoic on sonography, of low-signal intensity of T1-weighted magnetic resonance (MR) image, and of high-signal intensity on T2-weighted MR image. The combination of these sonographic and MR imaging findings may be suggestive of the diagnosis of lymphangioma.

Adult↗
PubMed1992

Aortic valve replacement in cardiac ochronosis.

Two patients with generalized ochronosis developed cardiovascular symptoms related to cardiac ochronosis with aortic valvular stenosis. One patient with a transvalvular pressure gradient of 150 mm Hg underwent emergency aortic valve replacement. The other patient with a transvalvular pressure gradient of 96 mm Hg underwent successful elective aortic valve replacement. Cardiac ochronosis is a rare disease that might be encountered, with the typical signs, during an elective, planned cardiac operation. The most frequent presenting feature of this disease seems to be aortic valvular stenosis.

Aged↗
PubMed1992

Voltage-sensitive calcium channels in a human small-cell lung cancer cell line.

Utilizing the whole-cell patch-clamp method we assessed the Ca2+ current (ICa) in well-established cell lines from human small-cell carcinoma (SCC) of the lung, NCI-H209 and NCI-H187. The Ca2+ current was readily observed in H209 tumour cells (90% of the cells tested), whereas H187 tumour cells only occasionally expressed Ca2+ channels (26% of the cells tested). H209 Ca2+ current was evoked by potentials greater than -30 mV and exhibited partial inactivation over the duration of a 40 ms command potential. This inward current was unchanged by alteration of the holding potential from -80 to -40 mV and the activation phase of the Ca2+ current was best fitted by Hodgkin-Huxley m(t)2 kinetics. H209 Ca2+ current was reduced over 80% by verapamil (100 microM), whereas w-conotoxin (5 microM) appeared to be without effect. In contrast, H209 Ca2+ current was rapidly abolished by nifedipine (10 microM), strongly suggesting the presence of L-type Ca2+ channels. Voltage-gated Ca2+ channels may be important to the secretion of ectopic hormones and the etiology and pathogenesis of Lambert-Eaton syndrome, an autoimmune disorder of the motor nerve terminal in which autoantibodies directed against voltage-gated Ca2+ channels are produced.

Calcium Channels↗
PubMed1992

Intracellular electrophysiological study of suprachiasmatic nucleus neurons in rodents: inhibitory synaptic mechanisms.

1. The mechanisms responsible for evoked and spontaneous fast inhibitory postsynaptic potentials (IPSPs) in the hypothalamic suprachiasmatic nucleus (SCN) were studied with intracellular recording. SCN neurons, primarily ones identified as receiving excitatory optic nerve input, were recorded in rat and guinea-pig brain slice preparations maintained in vitro. 2. In normal medium, electrical stimulation of a site dorsocaudal to the SCN evoked IPSPs from thirty-three of thirty-six neurons. The evoked IPSPs rose to the peak quickly (8.7 +/- 0.9 ms, mean +/- S.E.M.; n = 15 neurons) and decayed gradually with a time constant of 25 +/- 3 ms. Spontaneous IPSPs were present in each of the thirty-six neurons. These IPSPs had a rise-to-peak time of 7.2 +/- 1.0 ms (n = 6 neurons) and a decay time constant of 14 +/- 5 ms. 3. When recorded with potassium acetate-filled electrodes, the evoked and spontaneous IPSPs were hyperpolarizing at resting membrane potential (less negative than -70 mV) and had a reversal potential of around -75 mV. On the other hand, when recorded with potassium chloride-filled electrodes, the IPSPs were depolarizing at membrane potentials more negative than -50 mV and had an estimated reversal potential less negative than spike threshold. 4. Bath application of bicuculline (10-50 microM), a gamma-aminobutyric acidA (GABAA) receptor antagonist, resulted in a complete blockade of both the evoked (n = 16) and spontaneous (n = 13) IPSPs. The bicuculline effects were reversible, and were not associated with any significant and consistent change in baseline membrane potential or input resistance. The neurons impaled in bicuculline-containing medium (n = 11) exhibited neither spontaneous IPSPs nor evoked IPSPs. 5. In some neurons bicuculline-resistant hyperpolarizing potentials, which were similar to the fast IPSPs in time course, occurred spontaneously or were evoked by electrical stimulation of the optic nerve or the dorsocaudal site. A fast prepotential always preceded the hyperpolarizing potential, and hyperpolarizing currents blocked these events, indicating that they were not synaptic in origin. No slow IPSPs were detected. 6. The results suggest that fast IPSPs from non-retinal afferents exist in virtually all SCN neurons receiving excitatory retinal input, and that GABAA receptors associated with Cl- channels mediate the fast IPSPs.

Action Potentials↗
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↗
PubMed1992

Influences of ciclosporin pretherapy on 90% hepatectomized rats.

We studied the effect of ciclosporin (Cs) on rats which underwent a 90% hepatectomy. Rats were divided into two groups: group 1 (without Cs pretreatment) and group 2 (with Cs pretreatment). Animals were given a 4-day treatment of Cs (10 mg/kg/day) prior to hepatectomy. The 1-week survival, serum biochemistry and parameters for hepatocyte proliferation (indices for mitosis and 5-bromo-2-deoxyuridine uptake) were serially investigated. Although Cs pretherapy significantly upregulated liver cell proliferation in group 2, there was no improvement in the survival rate of the immunosuppressed animals (group 2) compared to the controls (group 1). The implications of Cs pretherapy are discussed in the setting of extensive hepatectomy.

Animals↗
PubMed1992

Retroperitoneal neurilemoma: CT and MR findings.

OBJECTIVE: Our objective was to characterize the CT and MR imaging findings of retroperitoneal neurilemomas. MATERIALS AND METHODS: We reviewed the CT and MR imaging findings in six women with retroperitoneal neurilemomas. RESULTS: Retroperitoneal neurilemomas were round, 5-13 cm in diameter, and located in the presacral pelvic retroperitoneum in four patients and adjacent to the kidney in two patients. CT findings of the tumors were well-demarcated round masses showing prominent cystic changes and oriented in a somewhat radial fashion. Medium and heavily T2-weighted MR images showed high-intensity necrotic areas and nonnecrotic areas of various signal intensity. CONCLUSION: CT findings of a round mass with prominent cystic degeneration, along with certain MR imaging characteristics, may be helpful in the preoperative diagnosis of retroperitoneal neurilemomas.

Adult↗
PubMed1992

Localized form of colitis cystica profunda--a case of occurrence in the descending colon.

An unusual localization of localized colitis cystica profunda in a 31-year-old man is described. The patient presented as anal bleeding and a protruding mass at the descending colon; the mass was polypoid and was made up of papillary epithelial hyperplasia with downward herniation of glands into the submucosa. Only one similar case involving a descending colon has been reported in the world literature.

Adult↗
PubMed1992

Prognostic significance of proliferating cell nuclear antigen-positive growth fraction in gastric adenomas.

The proliferative activity of gastric adenomas from 18 patients (42 endoscopic procedures) was compared with follow-up results. These cases were gastric adenomas proven by follow-up with repeated endoscopic procedures for more than 2 years, or were confirmed as gastric adenocarcinoma thereafter by histopathologic examination. Among the eighteen cases, nine showed carcinoma in the subsequent biopsies (group 1) and the remaining nine did not result in carcinoma (group 2). The proliferating cell nuclear antigen (PCNA) positivity rates of the two groups were significantly different (P < 0.01). The average PCNA positivity in group 1 was 33.1%, while it was 10.0% in group 2. The risk of developing carcinoma increased as the PCNA positivity increased: 0% in the low PCNA positivity group, 41% in the mid-positivity group and 89% in the high positivity group. We concluded that growth fraction could be taken into account as one of the most important prognostic factors for gastric adenoma, and accordingly repeated endoscopic biopsies with close follow-up should be carried out especially in the high PCNA positivity group.

Adenoma↗
PubMed1992

Differential pattern of perivascular type IV collagen deposits in phyllodes tumors of the breast.

Deposition of basement membrane extracellular matrix is influenced by adjacent tumor cells, and in some cases, the pattern of type IV collagen deposit is characteristic in malignant tumors. In this report, we analyzed the difference in type IV collagen deposition patterns between benign and malignant phyllodes tumors (PTs) of the breast. Of the 15 cases of PTs, 8 cases were benign PTs and 7 cases were malignant PTs. Three cases of other primary sarcomas of the breast (stromal sarcoma, angiosarcoma and osteosarcoma) and 2 cases of fibroadenomas were studied for comparison. The malignant PTs were distinguished from benign ones by increased mitotic figures, cellular atypism, and a higher proliferation index of stromal cells. Immunohistochemical staining against type IV collagen in malignant PTs revealed extensive to moderate deposition of type IV collagen around the small blood vessels in duplicate or multilayering pattern, while benign PTs showed minimal deposition in a single linear pattern. All of the three cases of other sarcomas revealed multilayering or meshwork pattern of type IV collagen around the blood vessels. The deposition of type IV collagen around the blood vessels may reflect the malignant behavior of the stromal tumors of the breast.

Adult↗
PubMed1992

[Prophylactic chemotherapy by regional arterial infusion in resected hepatoma patients].

We established risk factors for high post-resectional recurrence in patients with hepatocellular carcinoma (HCC). They included: (1)Vp (+), (2)IM (+), (3)more than 5 cm in diameter of the main tumor, and (4)gross type except single nodular tumor. Seventy HCC patients in this category were divided into two groups. In group 1, 11 patients prophylactically underwent hepatic arterial infusion chemotherapy after liver resection. Chemotherapeutic agents (MMC, 5-FU, ADM, CDDP) with Lipiodol were administered 4 times a year via Infuse-A-port. The remaining 59 cases served as the control without prophylactic infusion. Two-year survival rate was better in prophylactic group (75%) than in the control (46%, p = 0.063). The two-year disease-free survival was significantly improved in group 1 (40%) compared with that in group 2 (26%, p = 0.019). Based on our data, we suggest that prophylactic arterial infusion chemotherapy can be efficacious in alleviating hepatoma recurrence after liver resection.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1992

[Choice of left gastric vena caval shunt for esophageal varices--its rationale and clinical results].

We have surgically treated esophageal varices, particularly by left gastric vena caval shunt (LGCS) as the first choice in patients with good liver function (n = 40). The correlation between clinical outcomes and preoperative splanchnic hemodynamics, and therapeutical plans were evaluated: 1) Operative mortality was nil with recurrence rate of 15.0% and rebleeding noted in only one case. 2) The liver function according to Child's classification showed no significant changes before and after operation. Survival rate was more than 70% with good rehabilitation rate (over 90%). 3) The presence of hyperdynamic splanchnic circulation (left gastric venous flow and gastric wall microcirculation) lead to successful clinical results. 4) Combined use of sclerotherapy was efficacious in case of persistent and recurrent varices. We conclude that LGCS is successful in treating esophageal varices in the setting of hyperdynamic portal circulation with acceptable liver function.

Anastomosis, Surgical↗
PubMed1991

Chemical modification of Pseudomonas fluorescens malonyl-CoA synthetase by diethylpyrocarbonate: kinetic evidence for an essential histidyl residue on alpha subunit.

Malonyl-CoA synthetase from Pseudomonas fluorescens was inactivated by diethylpyrocarbonate (DEP) with the second-order rate constant of 775 M-1 min-1 at pH 7.0, 25 degrees C, showing a concomitant increase in absorbance at 242 nm due to the formation of N-carbethoxyhistidyl derivatives. The inactivated enzyme at low concentration of DEP (less than 0.2 mM) could be completely reactivated by hydroxylamine but not completely reactivated at high concentration (greater than 0.5 mM), indicating that there may be another functional group modified by DEP. Complete inactivation of malonyl-CoA synthetase required the modification of seven residues per molecule of enzyme; however, only one is calculated to be essential for enzyme activity by a statistical analysis of the residual enzyme activity. pH dependence of inactivation indicated the involvement of a residue with a pK alpha of 6.7, which is closely related to that of histidyl residue of proteins. When alpha subunit treated with DEP was mixed with beta subunits complex, the enzyme activity completely disappeared, whereas when beta subunit complex treated with the reagent was mixed with alpha subunit, the activity remained. Inactivation of the enzyme by the reagent was protected by the presence of malonate and ATP. These results indicate that a catalytically essential histidyl residue is located at or near the malonate and ATP binding region on alpha subunit of the enzyme.

Adenosine Triphosphate↗