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Biomedical subjects

U Kim

Publications and source records attributed to U Kim.

At least 55 records · Page 3Linked to original sources
PubMed1991

Pathophysiology of vascular smooth muscle in renin promoter-T-antigen transgenic mice.

The pathophysiological consequence of targeted production of SV-40 T-antigen to renin-expressing cells in the kidney of transgenic mice is reported. A histopathologic analysis of the kidney from adult transgenic mice (12-16 wk old) revealed the presence of severe vascular lesions manifested by marked atypical hyperplasia of vascular smooth muscle. The levels of plasma renin, kidney renin, and kidney renin mRNA were examined in 6- and 9-wk-old transgenic mice and were found to be significantly lower than their age-matched non-transgenic littermates and were nonresponsive to captopril treatment. However, there was no significant difference in conscious mean arterial pressure between transgenic and non-transgenic mice. The levels of renal renin mRNA in transgenics and nontransgenic littermates were compared throughout ontogeny and were found to be equal in newborns, elevated 3- to 5-fold in 1-wk-old transgenics, and yet decreased 10-fold by 6 wk of age in transgenic mice. Expression of the transgene in the kidney exhibited the proper developmental pattern and was properly restricted to juxtaglomerular cells in neonatal mice. Nevertheless, in adult mice, T-antigen-containing cells were found throughout the entire renal arterial tree. The observed ability of renal vascular cells to be recruited to express both renin and T-antigen suggests a mechanism that can explain the development of the renal pathology in these mice.

Animals↗
PubMed1991

The reappearance of abdominal tuberculosis.

Seventeen patients with abdominal tuberculosis were recently treated at our institution. Two distinct patient populations were identified--immigrants and individuals infected with the human immunodeficiency virus. Abdominal pain, weight loss and fever were the most common complaints, with abdominal tenderness and pyrexia the most frequent physical findings. Only five of 17 patients had concomitant pulmonary tuberculosis. A typical computed tomographic scan was helpful in the diagnosis. Diagnosis was made at emergency (five patients) or elective (six patients) laparotomy, by endoscopic (two patients) or percutaneous (three patients) biopsy or on the basis of roentgenologic and clinical evidence (one patient). All responded to antituberculous chemotherapy. With the spread of acquired immunodeficiency syndrome (AIDS), tuberculosis has become increasingly frequent in urban areas and it must be suspected in all immigrants and patients with AIDS presenting with abdominal complaints.

Abdomen↗
PubMed1991

Esophageal tuberculosis: a rare presentation with hematemesis.

Esophageal tuberculosis is rare, with only 26 cases previously reported in the literature. Patients usually present with progressive dysphagia or odynophagia. We report a patient with hematemesis that was later attributed to the erosion of tuberculous subcarinal lymph nodes into the esophagus. This presentation has been described in only two other patients, both of whom died of exsanguinating hemorrhage. The successful outcome in the present case rested on the availability of rapid diagnostic modalities and timely surgical intervention.

Adult↗
PubMed1990

Isolation and characterization of renin-expressing cell lines from transgenic mice containing a renin-promoter viral oncogene fusion construct.

We constructed transgenic mice containing a renin-promoter SV40 T antigen fusion transgene with the intention of inducing neoplasia in renin-expressing cells and isolating renin-expressing cell lines in vitro. We examined six kidney tumors from mice representing three different transgenic lines and found they expressed their endogenous renin gene. Initially, five nonclonal kidney tumor-derived cell lines were established which expressed their endogenous renin gene in addition to the transgene. They retained active renin intracellularly and constitutively secreted an inactive form of renin (prorenin). One of these cell lines was cloned to homogeneity. This line maintained high level expression of renin mRNA throughout 3 months of continuous culture. Although the cells contained an equal proportion of active and inactive renin, the species constitutively secreted into the media was predominantly (95%) prorenin. However, active renin secretion was stimulated 2.3- and 4.6-fold by treatment with 8-bromo-cAMP after 4 and 15 h, respectively. In addition, the presence of multiple secretory granules was confirmed by ultrastructural analysis. These cells, which express renin mRNA and can regulate secretion of active renin, should provide an excellent tool for studying renin gene regulation and secretion. Furthermore, these mice should provide a useful source for the establishment of renin-expressing cell lines from a variety of renin-expressing tissues.

Animals↗
PubMed1990

Tumor cell adhesion to frozen lymph node sections--a correlate of lymphatic metastasis in breast carcinoma models of human and rat origin.

The role of tumor cell adhesion in lymphatic metastasis of breast cancer was investigated in vitro using a rat mammary carcinoma model of four cell lines with different metastatic phenotypes, two human breast cancer cell lines, and cryostast sections of normal rat or human lymph nodes, respectively. A positive correlation was found between the adhesion levels obtained with three metastatic rat mammary cell lines (TMT-081 greater than MT-100M & TMT-50) and a non-metastatic line MT-W9B, the latter being 3-4 fold less adhesive to the lymph node sections than the metastatic tumors. This selective adhesion was specific, as it was not found with cryostat sections of rat liver and brain. Enzyme assays indicated that cell surface glycoproteins bearing terminal beta-galactoside residues were involved in the adhesion of the rat tumors. Adhesion of the human breast carcinoma cells Hs578T to sections of human lymph nodes was significantly higher than that of the normal breast epithelial cell line Hs578Bst, and comparable to adhesion of a second breast carcinoma line, MCF-7. Moreover, Hs578T cells isolated from regional lymph nodes of tumor-bearing nude mice were significantly more adhesive to human lymph node sections than the parental line. Adhesion of both human and rat tumors could be partially blocked by the addition of the synthetic peptide GRGDSPK and by antibodies directed to the beta 1 chain of integrin, suggesting that an integrin receptor may played a role in the adhesion. The results suggest that tumor cell adhesion to cryostat sections of lymph nodes is a correlate of the malignant phenotype in mammary tumors of diverse origins, and could be used to delineate the adhesion factors mediating lymphatic metastasis.

Animals↗
PubMed1990

Expression of murine renin genes in subcutaneous connective tissue.

A renin promoter-large tumor antigen (T antigen) fusion gene was constructed to provide a reporter function for renin expression in transgenic mice. These transgenic mice gave rise to tumors in subcutaneous soft tissue, which was attributed to transgene expression at this site. An immunohistochemical analysis of transgenic fetuses from several independent lines revealed scattered T-antigen-containing mesenchymal cells and fibroblasts in the subcutaneous layer of the skin between the panniculus carnosus muscle of the skin and the skeletal muscle of the body wall. This localization is consistent with the location of overt tumorigenesis in adult mice. This pattern was specific for the renin-T antigen fusion gene as no immunohistochemical staining was observed in transgenic fetuses containing a heterologous promoter-T antigen fusion gene. Northern blot analysis of tumor RNA indicated that most of the tumors expressed both T antigen and the endogenous renin gene Ren-1c. In addition, when multiple renin genes were introduced by crossing transgenic mice with nontransgenic DBA/2J mice, which contain another allele of the Ren-1 locus as well as the duplicated locus Ren-2, the resultant tumors expressed the Ren-2 gene. Northern blots were then used to analyze renin expression in the subcutaneous tissue of normal mice. Fully processed renin mRNA was detected in eviscerated 15.5-day postcoitus fetal and newborn carcasses and in newborn skin. Our data indicate that there is a renin-expressing cell population in fetal and newborn subcutaneous tissue.

Animals↗
PubMed1990

Differentiation of F9 cells is independent of c-myc expression.

The level of c-myc expression rapidly decreases during in vitro induced differentiation of mouse F9 embryonic teratocarcinoma to endoderm cells, raising the question of whether down regulation of c-myc expression is a part of the mechanism regulating differentiation. We have investigated the effect of enforced increases or decreases in c-myc RNA expression in F9 cells on growth and differentiation. The enforced expression of c-myc RNA in clones transfected with sense c-myc did not inhibit their terminal differentiation. Dramatically decreased c-myc RNA expression in antisense c-myc transfected clones also did not substantially alter the differentiation pathway, although the transformed cells withdraw from the cell cycle slightly earlier than control cells during the differentiation induction. These results suggest that the mechanism controlling differentiation operates independently of the level of c-myc RNA expression in F9 teratocarcinoma cells.

Animals↗
PubMed1990

A multifactorial analysis of mortality and morbidity in perforated peptic ulcer disease.

Perforated peptic ulcer disease remains a source of considerable morbidity and mortality, and the suggested methods of surgical therapy are diverse. We reviewed the course of 113 patients who were treated surgically and identified 14 factors that influenced the morbidity or mortality rates, or both. Multiple regression analysis showed that the number of coexisting medical conditions, a lower mean blood pressure level and the duration of acute perforation were independent risk factors for death, while age, use of a bronchodilator, a lower mean blood pressure level and the number of coexisting medical conditions correlated positively with all complications. A duodenal site was independently favorable with respect to all complications. The type of operation performed either simple closure, vagotomy and drainage or resection, did not influence morbidity or mortality. The most severely ill patients also did not benefit from any particular type of operation in the short term. Long term results were improved with definitive operation, as measured by the Visick classification and the need for reoperations. Definitive operations are recommended for virtually all patients with perforated peptic ulcer.

Age Factors↗
PubMed1989

Isolation and properties of cell lines from the metastasising rat mammary tumour SMT-2A.

A new cell line Rat mammary (Rama) 900 was isolated from the ascitic version of the SMT-2A metastasising rat mammary tumour by stepwise adaptation of the tumour cells to tissue culture. The cells grew mainly as loosely-adherent aggregates, and were dependent during the first 18 passages in vitro on a feeder layer of mesothelial-like cells (Rama 950) obtained from the same tumour. Subcutaneous injection of Rama 900 cells in fat pads of syngeneic Wistar Furth rats yielded anaplastic primary tumours and extensive, gross metastases including those in lungs, lymph nodes, liver and bones, similar to the parental transplantable tumour. The extent of metastatic spread from subcutaneous fat pads was increased by passage 17 in vitro for the Rama 900 cells. A similar extent of metastatic spread was achieved at earlier times by injecting the original cells with the non-tumorigenic Rama 950 cells in vivo. Subcutaneous injection of Rama 900 into thymectomised rats or MF1 nu/nu mice yielded fewer tumours, most of which regressed. No metastases occurred in the thymectomised rats and fewer metastases, mainly in lungs but not in lymph nodes, livers or bones, were seen in the nude mice. The ascitic tumours formed by intraperitoneal injection of nude mice contained both anaplastic rat cells similar to Rama 900 and mouse mesothelial-like cells similar to Rama 950. Although these anaplastic ascites cells failed to yield any tumours in syngeneic or thymectomised rats, they still produced tumours and metastases, including those in lymph nodes, in nude mice.

Animals↗
PubMed1989

Value of hepatic blood flow study in the diagnosis of hepatoma.

A case of hepatoma was diagnosed by means of radionuclide hepatic blood flow study (hepatic scintiangiography) and static liver-spleen imaging. The hepatic flow study clearly showed arterial blood supply to the right lobe of the liver and provided a strong indication for the diagnosis. Sonographic examination indicated some abnormalities but was less conclusive than radionuclide studies. Subsequent contrast angiogram, computerized tomography scan, positive hepatitis B profile, very high alpha-fetoprotein test, and laparatomy confirmed the diagnosis.

Adult↗
PubMed1989

Diffuse neurofibroma of the pylorus: a cause of gastric outlet obstruction.

We describe a benign diffuse neurofibroma of the pylorus, unassociated with von Recklinghausen's neurofibromatosis, which was a cause of pyloric stenosis; epigastric discomfort, vomiting, and weight loss of 60 lb were the most prominent symptoms. Partial gastrectomy resulted in a cure. The literature on nerve-sheath tumors of the stomach is reviewed.

Aged↗
PubMed1989

Surgical alternatives for the treatment of nonparasitic liver cysts.

Four cases of nonparasitic liver cysts treated with different operative procedures are presented. Asymptomatic small cysts need not be treated. Moderate-sized cysts require treatment based on the presence or absence of infection. Infected cysts must be drained externally via catheters or by marsupialization. Noninfected cysts may be adequately drained internally through partial cyst wall excision or unroofing. Large bile-containing cysts are best drained internally using a Roux-en-Y cystojejunostomy.

Aged↗
PubMed1989

Bilateral ureteral obstruction: an unusual complication of pancreatitis.

A case of bilateral ureteral obstruction associated with alcoholic pancreatitis in a 40-yr-old male patient is reported. Although pancreatitis complicated by pseudocyst formation has been known to involve intra- and extraabdominal organs, bilateral ureteral obstruction has not been reported. We postulated that in the case reported herein, periureteral fat necrosis involving both ureters was the primary etiological mechanism.

Adult↗
PubMed1988

Timing of surgery for acute gallstone pancreatitis.

One hundred four consecutive patients with acute gallstone pancreatitis underwent biliary surgery. The relationships between the timing of surgery, the severity of pancreatitis, and the surgical outcome were examined. Patients were divided into three groups according to the timing of surgery and into four groups according to the gross pancreatic pathologic characteristics observed at operation. Patients who underwent surgery early tended to have a higher incidence of common bile duct stones and more severe forms of pancreatitis; however, neither the timing of surgery nor the severity of pancreatitis had a significant impact on surgical outcome. Other factors, such as the level of serum amylase on admission and presence or absence of choledocholithiasis, did not significantly influence the natural history of the disease or the outcome of surgical therapy, whereas advanced age was associated with higher morbidity. Hemodynamic status and the overall condition of the patients were more important than either the timing of surgery or the gross pathologic characteristics of the pancreas in determining surgical outcome. We conclude that the timing of surgery is not a critical factor in the outcome of surgery for acute gallstone pancreatitis. Provided that the patient is stable and has no medical contraindications, surgery on the biliary tract can be performed safely at any time after initial resuscitation of the patient and confirmation of diagnosis.

Acute Disease↗
PubMed1987

Cocaine packet ingestion. Surgical or medical management?

Current controversy focuses on whether patients having ingested packets of cocaine should be treated medically or surgically. We surgically treated two such patients in whom conditions did not allow for conservative medical management, ie, the packets caused small-bowel obstruction in one patient while toxic manifestations of cocaine occurred in the other patient. Initial emergent surgical treatment vs success with conservative medical management appears to be directly related to whether a patient voluntarily receives treatment or is involuntarily brought to the hospital on suspicion of smuggling cocaine packet ingestion. Early surgical intervention is warranted unless the method of packet construction is known to be of high quality and if the patient is totally asymptomatic. If these criteria are present, intensive care monitoring, with surgical intervention on any change in status, is preferred.

Adult↗
PubMed1987

Heat sensitivity and membrane properties of metastasizing and non-metastasizing rat mammary tumors.

Paired lines of metastasizing and non-metastasizing transplantable rat mammary tumors were studied for their sensitivity to hyperthermia. The metastasizing TMT-081 and SMT-2A tumors were markedly more sensitive to heat injury as measured by tumor growth delay than were their non-metastatic counterparts MT-100 and MT-W9B. The metastasizing MT-081 tumor was also significantly more sensitive than the SMT-2A tumor. The differences in heat sensitivity were not the result of differences in intra-tumor temperatures attained during water bath heating. A more likely explanation for the variable response obtained with these tumors after heat treatment may be the inherent differences in stability and composition of their cellular membranes, particularly the plasma membrane.

Adenocarcinoma↗
PubMed1986

Pathogenesis and characteristics of spontaneously metastasizing mammary carcinomas and the general principle of metastasis.

Chemical mammary carcinogenesis in immunologically attennuated W/Fu female rats, subjected to specific and nonspecific immunostimulations, yielded many spontaneously metastasizing adenocarcinomas with varying degrees of glandular differentiation, and growth rates. The pathogenesis of these tumors suggested that while carcinogens transform target cells, the host immune system endows them with metastatic potential. The metastatic pathways were recognizable as hematogenous, lymphogenous, or hematogenous-lymphogenous combined, according to the capacity of the tumor cells to intravasate the lymphatic and/or vascular channel and traverse the pulmonary artery. The same metastatic pattern can be reproduced with cells from any of the organs involved, indicating that it is inherent in all cells within a given tumor, rather than being determined by the organs they colonize. The biological, biochemical and immunological characteristics of these tumors resemble human breast cancer thus becoming an effective tool in the formulation of the general principle of metastasis by malignant solid tumors.

9,10-Dimethyl-1,2-benzanthracene↗