Search PubMed⌕ Search

Biomedical subjects

K R Kim

Publications and source records attributed to K R Kim.

106 records · Page 6Linked to original sources

Disulfide-linked aggregation of thyroglobulin normally occurs during nascent protein folding.

In the endoplasmic reticulum (ER) of cultured porcine thyrocytes, newly synthesized thyroglobulin (Tg, the precursor in thyroid hormone synthesis) initially forms protein aggregates, which are dissolved into monomers and then assembled to dimers, before intracellular transport and secretion. However, studies suggest that in different physiological states and in different cells, folding efficiency in the ER may vary; with this in mind we have set out to further characterize the phenomenon of nascent Tg aggregation. In primary cultured thyrocytes, fresh thyroid follicular tissue (of porcine and rat origin), and the FRTL-5 cell line, nascent Tg appears transiently aggregated with mispaired, interchain disulfide linkages. Using a cell lysis procedure that maximally inhibits proteolysis as well as artifactual disulfide formation, Tg aggregates of M(r) > or = 2,000,000 can be stably isolated by gel filtration. Furthermore, stimulation with thyrotropin and other hormones that enhance Tg production may alter but does not eliminate formation of these aggregates. We conclude that transient disulfide-linked aggregation occurs normally during Tg folding in the ER of thyroid epithelial cells.

Animals↗

Gonadoblastoma and dysgerminoma associated with 46,XY pure gonadal dysgenesis--a case report.

Gonadoblastoma and dysgerminoma developed in a 24-year-old phenotypic female patient with 46,XY pure gonadal dysgenesis. This patient presented with primary amenorrhea. Clinical characteristics showed a typical stigmata of gonadal dysgenesis: primary amenorrhea, sexual infantilism, a small uterus and bilateral streak gonads. A 46,XY karyotype was made by lymphocyte culture. The patient was counseled to undergo a prophylactic bilateral gonadectomy, but she refused. Three years and three months after the initial diagnosis she felt a growing pelvic mass. Bilateral gonadectomy and total hysterectomy were performed. Histological examination revealed gonadoblastoma and dysgerminoma on both gonads. After surgery the patient received radiation therapy and also was started on hormone replacement therapy. Two years and two months after treatment by surgery the patient is well and free of recurrence.

Adult↗

Allotransplantation of rat islets into the cisterna magna of streptozotocin-induced diabetic rats.

Islets were isolated from the pancreata of Sprague-Dawley rats and transplanted into streptozotocin-induced diabetic outbred Wistar rats. The effect of transplantation of islets into the cisterna magna on the diabetic state of the recipients was compared with that of the conventional transplantation of islets into liver via the portal vein. After successful intraportal (IP) transplantation, rejection took place between days 7 and 15 in all diabetic recipients. All of the eleven rats surviving after stereotaxic implantation of islets into the cisterna magna returned to normoglycemia within 7 days after transplantation. Nine of the recipients with intra-cisterna magna (IM) islet allografts were still normoglycemic at 210 days after transplantation. The glucose disappearance rate of the IM transplant rats was slower than that of the IP transplant rats, and blood glucose returned to the normal basal level within 5 hr following glucose administration. Although the insulin levels were almost undetectable in cerebrospinal fluid before IM transplantation, the insulin levels were markedly increased after IM transplantation and twice as great in CSF than blood. Thus, these findings indicate that the cisterna magna can serve as an immunologically privileged site for implantation of allogeneic pancreatic islets, and islets in CSF can regulate and maintain normal glucose homeostasis via secretion of insulin across the blood-brain barrier.

Animals↗

Thyrotropin-secreting pituitary microadenoma.

We present a 45-yr-old male with clinical signs and symptoms of mild hyperthyroidism, high serum levels of T3, T4, and FT4 as well as serum TSH concentration. The elevated alpha-subunit level and alpha-subunit/TSH molar ratio were also observed. These findings indicated the presence of hyperthyroidism due to inappropriate secretion of TSH, whose neoplastic origin was documented by nuclear magnetic resonance scan showing a 0. 6 cm pituitary adenoma. Selective pituitary adenomectomy was completely successful; alpha-subunit, TSH, T3, T 4, and FT4 normalized, and euthyroidism was restored. Light microscopic immunohistochemistry showed that the adenoma was composed of TSH-secreting cells.

Adenoma↗

Transport kinetics of glucose and alanine in renal brush-border membrane vesicles of cadmium-intoxicated rabbits.

Changes in transport kinetics of D-glucose and L-alanine were studied in renal luminal membrane vesicles isolated from cadmium-intoxicated rabbits. Cadmium intoxication was induced by subcutaneous injections of CdCl2 at a dose of 2 mg Cd/kg/day for 2-3 weeks. Brush-border membrane vesicles were prepared from renal outer cortex and outer medulla by Percoll gradient centrifugation. Cadmium intoxication resulted in a marked attenuation of Na(+)-dependent transports of D-glucose and L-alanine in both outer cortical and outer medullary brush-border membrane vesicles, and this was due to reduction in Vmax and not Km. Similar results were obtained in normal vesicles directly exposed to free cadmium. These results suggest that in long-term cadmium-exposed animals free cadmium ions liberated in the proximal tubular cytoplasm may directly impair brush-border membranes thereby reducing capacity of Na(+)-dependent transport systems for glucose and amino acids.

Alanine↗

Alteration of renal amino acid transport system in cadmium-intoxicated rats.

Effects of cadmium intoxication on renal transport systems for various amino acids were studied. Subcutaneous injections of CdCl2, at a dose of 2 mg Cd/kg.day for 2 weeks, resulted in polyuria, proteinuria, glycosuria, phosphaturia, and aminoaciduria, as observed in chronic cadmium-intoxicated humans and experimental animals. The nature of aminoaciduria was nonspecific, including iminoacid as well as almost all species of neutral, acidic, and basic amino acids. In renal cortical brush border membrane vesicles isolated from cadmium-intoxicated rats, Na(+)-dependent transport of L-proline, L-alanine, and L-lysine was markedly attenuated, whereas the amino acid transport in the basolateral membrane vesicle was not significantly affected. Similar results were obtained in the normal membrane vesicles directly exposed to inorganic cadmium. These results indicate that cadmium intoxication impairs various Na(+)-amino acid cotransport systems in the renal brush border membrane, which leads to panaminoaciduria.

Amino Acids↗

Transport of organic compounds in renal plasma membrane vesicles of cadmium intoxicated rats.

Effects of cadmium intoxication on renal transport systems for various organic compounds were studied. Subcutaneous injections of CdCl2 (2 mg Cd/kg.day) for two to three weeks induced marked polyuria, glycosuria, and proteinuria without altering glomerular filtration rate. In renal cortical brush border membrane vesicles (BBMV) isolated from cadmium treated rats, Na(+)-dependent D-glucose uptake was markedly attenuated, and this was due to reduction in Vmax and not Km. Likewise, Na(+)-driven L-glutamate transport and H(+)-driven tetraethylammonium transport were significantly reduced. In renal cortical basolateral membrane vesicles (BLMV) of cadmium intoxicated rats, Na(+)-dependent succinate transport was drastically reduced. These results indicate that cadmium intoxication impairs various transport systems for organic compounds in the brush border and basolateral membranes of proximal renal tubules.

Cadmium Poisoning↗

Peritoneal keratin granulomas with carcinomas of endometrium and ovary and atypical polypoid adenomyoma of endometrium. A clinicopathological analysis of 22 cases.

Twenty-two cases of keratin granulomas of the peritoneum associated with endometrioid adenocarcinoma with squamous differentiation of the endometrium, the ovary, or both, and with an atypical polypoid adenomyoma of the endometrium were reviewed. Follow-up data were available in 18 cases. Twelve patients were well and disease free 13 months to 15.2 years postoperatively; one patient died of unrelated disease 21 years postoperatively; three patients were tumor free with a short duration of follow-up; one patient, who had a stage Ic ovarian tumor, died of pulmonary embolism during the treatment of recurrent tumor 1 year after operation; and a final patient, who had been followed for 3 months after operation for stage IV disease, was alive with residual tumor. At least six patients with stage I carcinomas were treated with postoperative irradiation because the granulomas had raised a suspicion of advanced disease. Follow-up data on the patients in this series suggest that peritoneal keratin granulomas have no prognostic significance and should be distinguished from viable tumor implants on microscopic examination.

Adenocarcinoma↗

Solid-phase extraction of chloramphenicol with graphitized carbon black.

The sorption and desorption properties of graphitized carbon black (GCB) were evaluated for enrichment of highly polarizable chloramphenicol (CP) from biological fluids. The distribution of CP between GCB and water lay strongly toward GCB. Among the organic solvents examined, methanol gave the lowest adsorption coefficient. The optimum packing amount of GCB, and the optimum volume and flow-rate of the eluent were deduced from the breakthrough curve and methanol elution curve, respectively. The inner diameter of GCB extraction columns was chosen from the sorption efficiency curve obtained by plotting CP recovery against column inner diameter. The solid-phase extraction method using GCB was applied to the assay of CP in serum samples in the concentration range of 5 to 50 micrograms/ml.

Absorption↗

Effects of long-acting somatostatin analogue (Sandostatin) on manifest diabetic ketoacidosis.

Insulin deficiency and counterregulatory hormone excess are the basic process in the development of diabetic ketoacidosis (DKA). Somatostatin, which suppresses the secretion of glucagon and growth hormone, has been known to attenuate the rate of gluconeogesis and ketogenesis in insulin-dependent diabetes mellitus patients. However, the therapeutic efficacy of somatostatin has not been approved to be practical in the treatment of manifest DKA. To examine the additive effect of octreotide, the synthetic long-acting somatostatin analogue SMS 201-995, to conventional treatment of manifest DKA, we compared the correction time of acidosis, ketonuria, and hyperglycemia of patients treated with an intravenous infusion of low-dose insulin (4 units per hour) plus subcutaneous injection of octreotide (50 microg every 6 hours) by low-dose insulin alone. The correction time for hyperglycemia and acidosis did not show any difference between groups (p = 0.089, p = 0.82). However, the time for disappearance of ketonuria of the octreotide-treated group (38.0 +/- 32.0 h) was reduced significantly compared to other group (68.3 +/- 26.0 h) (p = 0.048). These results indicated that the addition of octreotide to conventional treatment of DKA might improve the correction of ketosis, but would not allow more rapid control of acidosis and hyperglycemia in manifest DKA.

Adolescent↗

Malignant mixed müllerian tumors of the ovary: experience with cytoreductive surgery and platinum-based combination chemotherapy.

This study reviews the clinical outcome and prognosis of patients with malignant mixed müllerian tumors (MMMTs) of the ovary treated with optimal cytoreductive surgery, leaving no residual disease, and platinum-based chemotherapy. Ten patients diagnosed with MMMT of the ovary after complete surgical staging from February 1993 to February 2004 at Asan Medical Center in Korea were studied retrospectively. All ten patients were treated with optimal cytoreductive surgery, leaving no gross residual disease. Seven patients received ifosfamide/cisplatin chemotherapy, and the remaining three patients received other platinum-based combination chemotherapy. Demographic data, pathologic findings, treatments, and survival time were reviewed. Of the ten patients, two were scored at FIGO stage IIC, seven were at stage IIIC, and one was at stage IV. The median survival time of all ten patients was 46 months. The overall survival rate was 60.0% at 1 year, 40.0% at 2 years, and 20.0% at 5 years. Platinum-based combination chemotherapy after optimal cytoreductive surgery may be effective in the treatment of ovarian MMMT.

Adult↗

Primary peritoneal carcinoma: experience with cytoreductive surgery and combination chemotherapy.

The objective of this study was to review the clinical outcome and prognosis of patients with primary peritoneal carcinoma (PPC) treated with cytoreductive surgery and combination chemotherapy. We retrospectively reviewed the charts of 27 patients with histologically confirmed PPC, treated between March 1990 and February 2004 at Asan Medical Center, South Korea. The review included demographic data, pathologic findings, treatments, and outcomes. The mean age of the 27 patients was 57.5 +/- 7.2 years, and the rate of optimal cytoreduction was 70.4%. Seven patients had stage IIIB, 17 had stage IIIC, and 3 had stage IV; all patients received adjuvant chemotherapy. There were 4 patients with progressive disease, 5 partial responders, and 15 complete responders; the remaining 3 patients were nonevaluable. At the time of the review, 10 patients were alive without evidence of disease, 3 were alive with disease, and 14 had died from disease. The median overall survival time was 41 months, and the overall 5-year survival rate was 18.1%. Patients who had optimal cytoreduction had a longer median survival (42 months) than those who had suboptimal cytoreduction (10 months; P < 0.05). Combination chemotherapy after optimal cytoreductive surgery may be effective in the treatment of patients with PPC.

Adult↗