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Biomedical subjects

H K Yang

Publications and source records attributed to H K Yang.

At least 19 recordsLinked to original sources
PubMed1996

Laparoscopic cholecystostomy for acute acalculous cholecystitis.

Acute acalculous cholecystitis (AAC) can occur in up to 18% of severely injured patients. Diagnosis is made by positive ultrasound findings of gallbladder sludge, hydrox, and wall thickening. There may also be recent-onset jaundice, positive ultrasound induced Murphy's sign, and unexplained sepsis. Mortality can be as high as 50%. Laparoscopic confirmation was obtained in six ICU trauma patients when omentum was drawn up over a distended gallbladder. Laparoscopic cholecystectomy (LC) was done by first directly decompressing the gallbladder through the fundus. This trocar was replaced by a 16 French Foley catheter passed through an Endoloop into the gallbladder and secured by tightening the loop around a cuff of gallbladder. Sepsis resolved in all cases. Only one required subsequent laparoscopic cholecystectomy. LC has a low morbidity and may be life saving during the early stages of AAC. It is not indicated in gangrene or perforation of the gallbladder.

Acute Disease↗
PubMed1996

Iatrogenic "respiratory acidosis" during laparoscopic preperitoneal hernia repair.

This is the first report, to our knowledge, of a case of massive subcutaneous emphysema during totally preperitoneal laparoscopic hernia repair causing a "respiratory acidosis" with a systemic pH 7.20 and a pCO2 of 64 and PO2 of 84. The acidosis was corrected by increased mechanical ventilation. It appears that because of its lack of defined borders, the preperitoneal space is particularly vulnerable to the formation of massive subcutaneous emphysema. Thus, there is a large potential surface area for CO2 absorption. The complication may be prevented by increased attention to the length of fascial incisions, inflation of balloon expanding devices, and securing gripping devices in the port sites.

Acidosis, Respiratory↗
PubMed1996

Resection of Dieulafoy's lesion by a combined endoscopic and laparoscopic approach.

Dieulafoy's lesion is a vascular malformation, usually of the stomach but occasionally of the small or large bowel. It is an uncommon but clinically significant source of massive upper gastrointestinal (GI) hemorrhage. The lesion is generally located high on the lesser curvature in the proximal stomach. Although most bleeding can be controlled endoscopically, surgery is occasionally required. The traditional approach was open laparotomy, gastrotomy to localize the lesion, followed by partial gastrectomy or wedge resection. The following case report describes and illustrates a method of intraluminal endoscopic localization of the lesion followed by laparoscopic gastric wedge resection using a 3-port technique.

Aged↗
PubMed1995

TP53 and RAS mutations in metachronous tumors from patients with cancer of the upper aerodigestive tract.

Patients who initially develop an upper aerodigestive tract cancer have an increased risk of second primary cancers. We examined TP53 and RAS mutations and p53 protein in 21 tumors from 10 patients with upper aerodigestive tract cancer who developed a metachronous tumor, to assess the genetic changes that occur in multiple primary tumors from the same individual. Thirteen of 21 (62%) tumors were found to have mis-sense mutations of either TP53 or RAS. Six tumors had TP53 mutations in codons 5 to 8 and 10 tumors from 7 patients had mutations of codons 12 or 13 of K-RAS. Only one patient had concordance of a mutation in 2 tumors; this mutation occurred in K-RAS and was accompanied by discordance of TP53 mutation. Three patients had tumors discordant for both TP53 and RAS mutations. Smoking-related tumors had TP53 and RAS mutations which were transversions in 11 (9 G:C to T:A and 2 G:C to C:G) and transitions in 3 (2 G:C to A:T and 1 A:T to G:C). Tumors not associated with smoking contained only transitions (both G:C to A:T). p53 protein was detected by immunohistochemistry in 7 of 13 (54%) tumors and was concordant in the multiple tumors of 3 patients. Three of the 7 tumors staining for p53 also had TP53 mutations. Thus, genetic alterations are discordant in multiple primary cancers and the pattern of mutations is similar to that found in patients with a single primary tumor, supporting the concept that these cancers arise independently.

Adenocarcinoma↗
PubMed1995

Lymph node metastasis as a significant prognostic factor in early gastric cancer: analysis of 1,136 early gastric cancers.

BACKGROUND: Gastric cancer is the most frequent cancer and the leading cause of death from cancer in Korea. Early gastric cancer has been defined as a gastric carcinoma confined to mucosa or submucosa, regardless of lymph node status, and has an excellent prognosis with a > 90% 5-year survival rate. From 1974 to 1992, we encountered 7,606 cases of gastric cancer and performed 6,928 gastric resections. Among them, 1,136 cases were early gastric cancer (14.9% of all gastric cancer cases and 16.4% of resected gastric cancer cases). METHODS: A retrospective analysis of 1,136 cases of early gastric cancer was performed to evaluate the prognostic significance of clinicopathologic features (sex, age, tumor location, gross type, histologic type, depth of invasion, status of lymph node metastasis, resection type). Lymph node metastasis was classified into three groups: N(n = 0) for no lymph node metastasis; N(n = 1-3) for one to three lymph node metastases; and N(n > 3) for more than three lymph node metastases. All patients received radical total or subtotal gastrectomy with lymph node dissection. RESULTS: In univariate and multivariate analysis of these nine factors, the only statistically significant prognostic factor was regional lymph node metastasis (p < 0.001). The others had no statistically significant association with prognosis. Lymph node metastasis was present in 178 cases (15.7%). The factors associated with the lymph node metastasis were depth of invasion and gross type [protruding type (e.g., types I, IIa)]. One hundred twenty-five of these patients had one to three lymph node metastases, and 53 cases had more than three lymph node metastases. The difference in 5-year survival rates among these groups was statistically significant: 94.5% for N(n = 0), 88.3% for N(n = 1-3), and 77.3% for N(n > 3). CONCLUSION: We propose that for early gastric cancer, lymph node dissection is necessary in addition to gastric resection, at least in patients with a high risk of lymph node metastasis.

Adult↗
PubMed1994

Prognostic significance of signet ring cell carcinoma of the stomach.

A retrospective analysis of 3,702 gastric cancer patients operated on between 1981 and 1991 was carried out to compare the clinicopathological features of signet ring cell (SRC) gastric cancer with other cell types. Four hundred and fifty patients (12.2%) had signet ring cell gastric carcinoma. There was a tendency for patients with the signet ring cell gastric cancer to be younger and female, and of the middle-third part of stomach to be involved. The proportion of early gastric cancers in signet ring cell gastric cancers was 43%, which was significantly higher than in the other histological types [33% in well differentiated (WD) type, 23% in moderately differentiated (MD) type, and 13% in poorly differentiated (PD) type]. Early stage signet ring cell gastric carcinomas were less invasive in depth and had less lymph node metastasis. However, signet ring cell gastric cancers in advanced stage were more invasive and had more lymph node metastasis than other cell types. There was no significant difference in five year survival rates (5YSR) among patients with different histological cell types in early stage gastric cancers. But, in advanced gastric cancers, the prognosis for patients with the signet ring cell type was significantly worse than for the other types (SRC, 31.9% 5YSR; WD, 45.1% 5YSR; MD, 38.4% 5YSR; PD, 34.5% 5YSR) (P < 0.05), which can be explained by the finding that advanced gastric cancers with signet ring cell type have a larger tumour size, more lymph node metastasis, a deeper invasive depth and more Borrmann type 4 lesions than other histological types. This study suggests that signet ring cell gastric cancer may have a different biological behaviour.

Aged↗
PubMed1993

Human small cell lung cancer cell lines express functional atrial natriuretic peptide receptors.

Small cell lung cancer cell (SCLC) lines, NCI-H82, NCI-H660, and NCI-H1284, and HeLa cells were analyzed for the presence of atrial natriuretic peptide (ANP) receptors. In these SCLC cell lines and HeLa cells, ANP A receptor mRNA was identified by Southern blot analyses of polymerase chain reaction products and RNase protection assays using poly(A)(+)-selected RNA. Saturable binding assays revealed that HeLa cells had 2000 to 5000 high affinity atrial natriuretic peptide receptors per cell with a dissociation constant of 140 pM. In the SCLC cell lines, the binding was saturable but too low to accurately estimate the number of binding sites. After addition of human ANP, radioimmunoassays revealed accumulation of cyclic GMP in SCLC cells as well as HeLa cells in a dose-dependent fashion. The half-maximal stimulation concentration of cyclic GMP accumulation in HeLa and these SCLC cell lines was approximately 2 nM. Tetrazolyl blue assays and tritiated thymidine incorporation did not show any remarkable growth inhibition or growth stimulation of SCLC cell lines after addition of human ANP up to 3.3 microM, more than 1000-fold greater than the half-maximal stimulation concentration of cyclic GMP accumulation. Our results indicate that human SCLC cells express functional ANP receptors but ANP addition produced no detectable change in their growth pattern.

Atrial Natriuretic Factor↗
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

Is the new UICC staging system of gastric cancer reasonable? (Comparison of 5-year survival rate of gastric cancer by old and new UICC stage classification).

In the new UICC TNM system for gastric cancer approved in 1985, a T1 lesion with lymph node (LN) metastasis is classified as stage, Ib; in the old TNM system this was classified as stage III. This is contradictory to a general rule of the UICC TNM system, whereby cancer with LN metastasis is classified as stage II or III. Two thousand and sixty-three patients with less than T4 gastric cancer who were treated at Seoul National University Hospital from 1970 to 1986 were analysed for significant prognostic factors. Survival curves were subsequently analysed according to the number of LN metastases and the depth of invasion. As a result of multivariate study for clinical and pathological features such as age, tumour location, gross appearance, histological type, depth of tumour invasion and regional lymph node metastasis, we confirmed that only two factors--regional lymph node metastasis and depth of gastric wall invasion--are significant. We showed that when the LN variable is classified according to the number of LN metastases (0 group, 1-3 group, > 3 group) like the UICC TNM classification of colorectal cancer, the survival curves are similar to those reported by the Japanese Research Society for Gastric Cancer. The authors propose the modification of the UICC TNM classification system according to depth of invasion and the number of LN metastases, whereby a T1 lesion with LN metastasis is classified as stage IIa instead of stage 1b.

Adenocarcinoma↗
PubMed1992

Results of surgery on 6589 gastric cancer patients and immunochemosurgery as the best treatment of advanced gastric cancer.

Results of 6589 gastric cancer operations at the Department of Surgery, Seoul National University Hospital, from 1970 to 1990 were reported. About two thirds (76.6%) were advanced gastric cancer (stages III and IV). The 5-year survival rate of operated stage III gastric cancer was only 30.6%, with frequent recurrence. Conversely, cell-mediated immunities of advanced gastric cancer patients were significantly decreased. Therefore, to improve the cure rate and to prevent or delay recurrence, curative surgery with confirmation of free resection margins and systematic lymph node dissection of perigastric vessels were performed and followed by early postoperative immunotherapy and chemotherapy (immunochemosurgery) in stage III patients. To evaluate the effect of immunochemosurgery, two randomized trials were studied in 1976 and 1981. In first trial, 5-fluorouracil, mitomycin C, and cytosine arabinoside for chemotherapy and OK 432 for immunotherapy were used. The 5-year survival rates for surgery alone (n = 64) and immunochemosurgery (n = 73) were 23.4% and 44.6%, respectively, a significant difference. In the second trial, there were three groups: group I, immunochemosurgery (n = 159); group II, surgery and chemotherapy (n = 77); and group III, surgery alone (n = 94). 5-Fluorouracil and mitomycin C for chemotherapy and OK-432 for immunotherapy were administered for 2 years. The 5-year survival rate of group I was 45.3%, significantly higher than the 29.8% of group II and than the 24.4% of group III. The postoperative 1-chloro-2.4-dinitrobenzene test, T-lymphocyte percentage, phytohemagglutinin- and con-A-stimulated lymphoblastogenesis and the antibody-dependent cell-mediated cytotoxicity test showed more favorable values in the immunochemosurgery group. Therefore, immunochemosurgery is the best multimodality treatment for advanced gastric cancer.

Anastomosis, Surgical↗
PubMed1992

Enterolith ileus: a rare complication of duodenal diverticula.

Small bowel obstruction secondary to an enterolith formed within a duodenal diverticulum is a rare complication. Twenty-nine cases of enterolith ileus have been reported in the literature. This is a case report of the 30th, with review of the literature. Enterolith ileus closely resembles gallstone ileus in its clinical presentation. Diagnosis is established by documenting normalcy of gallbladder and the presence of small bowel diverticula.

Aged↗
PubMed1983

Band keratopathy in MRL/l and MRL/n mice.

To define ocular abnormalities in mice with autoimmune disease, we performed biomicroscopic examinations and examined ocular tissue in MRL/l, MRL/n, NZB, NZB/NZW, and Palmerston North mice. Results were compared with MRL/Mp--lpr/lpr, C57BL/6J--lpr/lpr, and normal control strains. Eighty-seven percent of MRL/l and MRL/n mice had typical band keratopathy; this was confirmed by histologic examination. Posterior uveitis was found in 35% of adult MRL/l mice. MRL substrains are potentially important models of ocular disease.

Animals↗
PubMed1983

Effects of microwave exposure on the hamster immune system. I. Natural killer cell activity.

Hamsters were exposed to repeated or single doses of microwave energy and monitored for changes in core body temperature, circulating leukocyte profiles, serum corticosteroid levels, and natural killer (NK) cell activity in various tissues. NK cytotoxicity was measured in a 51Cr-release assay employing baby hamster kidney (BHK) targets or BHK infected with herpes simplex virus. Repeated exposure of hamsters at 15 mW/cm2 for 60 min/day had no significant effect on natural levels of spleen-cell NK activity against BHK targets. Similarly, repeated exposure at 15 mW/cm2 over a 5-day period had no demonstrable effect on the induction of spleen NK activity by vaccinia virus immunization, that is, comparable levels of NK were induced in untreated and microwave-treated animals. In contrast, treatment of hamsters with a single 60-min microwave exposure at 25 mW/cm2 caused a significant suppression in induced spleen NK activity. A similar but less marked decrease in spleen NK activity was observed in sham-exposed animals. Moreover, the sham effects on NK activity were not predictable and appeared to represent large individual animal variations in the response to stress factors. Depressed spleen NK activity was evident as early as 4 h postmicrowave treatment and returned to normal levels by 8 h. Hamsters exposed at 25 mW/cm2 showed an elevated temperature of 3.0-3.5 degrees C that returned to normal within 60 min after termination of microwave exposure. These animals also showed a marked lymphopenia and neutrophilia by 1 h posttreatment that returned to normal by 8-10 h. Serum glucocorticosteroids were elevated between 1 aNd 8 h after microwave treatment. Sham-exposed animals did not demonstrate significant changes in core body temperature, peripheral blood leukocyte (PBL) profile, or glucocorticosteroid levels as compared to minimum-handling controls.

Adrenal Cortex Hormones↗
PubMed1982

Corneal melting with intraocular lenses.

Five patients with collagen vascular disease and keratoconjunctivitis sicca underwent cataract surgery and implantation of intraocular lenses. Postoperative development of corneal melting may have been potentiated by the use of topical 0.1% dexamethasone sodium phosphate alcohol and neomycin sulfate. Permanent visual loss occurred in two patients. Implant removal was necessary in two eyes. Medical management consisted of discontinuance of administration of steroids and antibiotics, as well as the addition of tear substitutes, cycloplegics, and pressure patching.

Aged↗
PubMed1981

Self-inflicted ocular mutilation.

Self-inflicted mutilation of the eyes is an uncommon but fairly distinct entity. Patients are typically young men; they often have criminal records and histories of drug abuse. Underlying schizophrenia is a common feature. The patients frequently suffer from castration fears, oedipal conflicts, repressed homosexual impulses, severe guilt, and a need for punishment. We treated two patients with this disorder. The first, a 26-year-old prison inmate convicted of murdering his grandfather, cut his eyes with a razor blade. He had previously attempted to commit suicide, suffered from delusions, and experienced auditory hallucinations. Surgical repair of his injuries improved his visual acuity to R.E.: 6/15 (20/50) and L.E.: 6/30 (20/100). The second patient, a 24-year-old inmate of a mental institution, had previously undergone a lensectomy for a hypermature cataract induced by a self-inflicted lye burn in his left eye. One year later, he was treated for lacerations of his right eye and partial amputation of his tongue. In the year between admissions, he had enucleated his left eye. Visual acuity in his remaining eye was no light perception, so no surgery was performed.

Adult↗
PubMed1981

Specular microscopy with intraocular lens implantations.

Specular microscopy performed six months postoperatively on 122 lens implant patients showed that endothelial cell loss rates varied according to method of cataract extraction and type of lens implant. Phacoemulsification with implantation of a Platina-style lens was associated with the highest cell loss; planned extracapsular cataract extraction with implantation of a Choyce-style or J-loop lens was associated with the lowest cell loss. The presence of marked striate keratopathy on the first postoperative day was directly related to endothelial cell loss.

Aged↗
PubMedDate not supplied

Significant prognostic factors by multivariate analysis of 3926 gastric cancer patients.

Univariate and multivariate analyses of 3926 selected gastric cancer patients collected between 1981 and 1991 were made to confirm several clinicopathologic prognostic factors and to evaluate the effectiveness of postoperative immunochemotherapy with OK-432, 5-FU, and mitomycin C in stage III gastric cancer. Five-year survival rates for each category of prognostic variables were obtained; and in the univariate analysis, most of the factors (including age, depth of invasion, lymph node metastasis, location of primary tumor, histologic differentiation, and gross type except for sex) showed some significance. Multivariate analysis was conducted and verified significant prognostic factors. Depth of invasion and lymph node metastasis were found to be the most powerful factors (p < 0.001); gross type, location, and histologic differentiation were additional significant factors (p < 0.05). For postoperative treatment, immunochemosurgery was most effective in stage III patients (p < 0.05). In conclusion, we may predict a prognosis for gastric cancer more precisely on the basis of these independent prognostic factors, and immunochemosurgery may be a valuable means to treat advanced gastric cancer.

Adult↗