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Biomedical subjects

S C Yu

Publications and source records attributed to S C Yu.

At least 55 records · Page 3Linked to original sources

Intermittent intussusception caused by colonic lipoma.

Colonic lipomas are rare, usually small, and occur most often in the right colon, particularly in the cecum. They are most common in elderly women. Intermittent episodes of intussusception are not uncommon in patients with colonic lipoma, but they are usually caused by larger pedunculated lipomas. We report a 43-year-old woman with a large colonic submucosal lipoma that induced intermittent colocolic intussusception. The patient presented with symptoms of peptic ulcer, including intractable upper abdominal pain, which did not resolve with treatment. Abdominal sonography showed typical findings of intussusception caused by a lipoma, but the manifestations on barium enema and computed tomography mimicked a malignant colonic tumor. The patient's abdominal pain disappeared after right hemicolectomy and the tumor was demonstrated to be a lipoma. The postoperative course was uneventful; there was no evidence of recurrence at follow-up 6 months later. Physicians should be aware that surrounding organs should also be evaluated in cases of chronic peptic ulcer with intractable upper abdominal pain.

Adult↗

Laparoscopic subtotal gastrectomy with lymphadenectomy in a patient with early gastric cancer.

Laparoscopic surgery is rapidly gaining in popularity among general surgeons. It is not widely used to treat abdominal malignancies because of technical difficulties and the fear of peritoneal dissemination. We describe the use of laparoscopic surgery to treat early gastric cancer. A 66-year-old man was diagnosed with early gastric adenocarcinoma by endoscopic ultrasonography and biopsy. Subtotal gastrectomy along with removal of the perigastric (D1) and selective extraperigastric lymph nodes over the celiac trunk was accomplished laparoscopically, through five punctures and a minilaparotomy. The patient's convalescence was uneventful. Bowel sounds were heard on postoperative day 1. On postoperative day 3, he passed flatus. The patient was started on a clear liquid diet on postoperative day 5. There was neither leakage nor obstruction after oral intake. He was discharged on postoperative day 11. No local recurrence or distant metastasis was found during 16 months' follow-up. This is the first report of successful laparoscopic resection of early gastric cancer with lymph node dissection in Taiwan.

Aged↗

Percutaneous needle aspiration in the treatment of hepatic abscess: factors influencing patients' outcome.

Sixty-four consecutive cases of hepatic abscess diagnosed over a 6-year period and all treated by ultrasound-guided percutaneous needle aspiration and systemic antibiotics were retrospectively reviewed to ascertain factors influencing the outcome in these patients. The 64 patients had in total 101 liver abscesses which averaged 4.7 cm in diameter. Two patients (3.1%) required surgery for associated biliary tract disease. Five patients (7.8%) died from septicaemia and/or serious condition or malignancy. The remaining 57 patients (89.1%) were successfully treated--45 cases (70.3%) showed fully-resolved abscess/es after a mean period of 69.9 days after initial aspiration; 12 patients (18.8%) showed markedly-shrunken abscess cavity size over an average of 30.7 days and all were asymptomatic on discharge from hospital. No correlation was demonstrated between number of abscesses and successful patient recovery--42 of 46 patients (91.3%) with solitary hepatic abscess recovered, 6 of 8 patients (75.0%) with 2 abscesses and 9 of 10 patients (90.0%) with more than 2 abscesses were successfully treated. No correlation was detected between abscess size and number of aspirations required, majority of abscesses (73.3%) requiring no more than two aspirations irrespective of their sizes. Of the 57 patients cured, no significant correlation between abscess size and degree of abscess healing was evident. Our results demonstrate the effectiveness of percutaneous needle aspiration and it should be considered a first-line treatment in the management of liver abscess, irrespective of their number and sizes.

Adolescent↗

Advantages of laparoscopic splenectomy for splenomegaly due to hematologic diseases.

Recent advancements in laparoscopic surgery have made laparoscopic splenectomy possible. We retrospectively compared the outcomes of laparoscopic versus open splenectomy in patients with idiopathic thrombocytopenic purpura (ITP) or beta-thalassemia. From July 1993 to July 1997, 52 patients (ITP, 43 cases; beta-thalassemia, 9 cases) underwent either laparoscopic (30 patients, 9 men, 21 women; average age, 36.9 years) or conventional open splenectomy (22 patients, 5 men, 17 women; average age, 34.3 years). The two groups were similar in terms of sex, age, diagnosis, duration of disease, preoperative platelet count, and spleen size. The mean surgical time, estimated amount of blood loss, duration of postoperative recovery, analgesic usage, and complications were compared between the two groups. Laparoscopic splenectomy was successful in 29 (97%) of the 30 patients. The mean surgical time in the laparoscopy group was longer than in the open splenectomy group (190.6 vs 113.9 minutes, p < 0.01). The laparoscopy group had earlier postoperative oral intake (15.2 vs 52.6 hours, p < 0.01), less usage of analgesics (meperidine 50 mg/unit, 1.1 vs 2.8 units, p < 0.01) and a shorter postoperative hospital stay (4.1 vs 6.8 days, p < 0.01). The estimated blood loss, incidence of accessory spleen, surgical complication rate, and recurrence rate of thrombocytopenia were similar in the two groups. Our findings show that laparoscopic splenectomy in patients with ITP or beta-thalassemia is as safe as the open approach. While laparoscopy required a longer surgical time, the recovery period was shorter, analgesic use was less, and physical discomfort was less severe.

Adolescent↗

Microbiological evaluation of bottled uncarbonated mineral water in Taiwan.

The microbiological quality of 136 samples of bottled uncarbonated mineral water, including 88 domestic and 48 imported samples, was investigated. The numbers of samples with heterotrophic plate count (HPC) over the maximum level legally permitted in Taiwan (200 colony forming units ml-1) were 45 (51.1%) and 29 (60.4%) for domestic and imported samples, respectively. Coliforms and faecal streptococci were not detectable in the samples tested. Two of the domestic samples were contaminated with Aeromonas hydrophila and four with Pseudomonas aeruginosa. Bacteria isolated from water samples were identified as species of Pseudomonas, Aeromonas, Flavobacterium, Pasteurella, Xanthomonas, and Staphylococcus. Mold and yeast were detected in 38.6% and 18.8% of domestic and imported samples, respectively. The HPC of bottled mineral water stored at 25 degrees C increased quickly to 10(4)-10(5) colony forming units ml-1. In inoculation studies both A. hydrophila and Escherichia coli grew very well and mutualistic growth for both organisms was observed in mineral water at 25 degrees C.

Bacteria↗

Nasal lymphoma: results of local radiotherapy with or without chemotherapy.

BACKGROUND: Primary nasal lymphoma is a rare disease. Although most patients are initially seen in early Ann Arbor stages, their prognosis is poor. The prognostic significance of local tumor bulk has not been well studied. METHODS: Twenty-one patients with nasal lymphoma treated between 1985 and 1992 were retrospectively studied. Sixteen patients (76%) below the age of 75 years received combined radiotherapy and chemotherapy. One young patient with early disease and 4 elderly patients had radiotherapy alone. Twelve cases (57%) were diagnosed as pleomorphic T-cell lymphoma based on typical histologic features alone. Immunophenotyping was performed in 10 cases; 8 were T cell and 2 were B cell. Seventeen patients (81%) had Ann Arbor clinical stage IE disease, and 4 had stage IIE disease. The local tumor extent was assessed by endoscopy in all patients and by computerized tomography (CT) in 14 patients. Eleven local tumors (52%) extended to the posterior ethmoids, sphenoid sinus, orbit, or beyond. Using a T-stage system, the prognostic significance of local tumor bulk was evaluated for stage IE patients. RESULTS: At a median follow-up time of 16.8 months, the lymphoma recurred in 13 patients; 10 patients had systemic relapse and 10 patients, local relapse. The 5-year actuarial overall survival rate was 24%. Complete response to chemotherapy was achieved in 5 of 16 patients (31%). Four of the 6 patients who remained alive and disease-free were chemotherapy complete responders. Among stage IE patients, those with early and those with advanced local disease did not have significantly different survival. CONCLUSIONS: In view of the high systemic and local relapse rates, more-effective chemotherapy is needed to improve the survival rates, and the role of combined chemotherapy and radiotherapy should be evaluated. Further studies are required to identify patients at high risk of relapse for clinical trials with investigational treatment.

Adult↗

Differential expression of protein tyrosine kinases and their phosphorylation in murine Th1 cells anergized with class II MHC-peptide complexes.

In resting T cell clones, antigen presentation with immobilized anti-CD3 or anti-T cell receptor (TCR) is known to result in a state of anergy as characterized by unresponsiveness to normal antigenic restimulation. Similarly, T cell unresponsiveness could be induced by immobilized (plate-coated) complexes of purified class II MHC and antigenic peptide. It is not clearly defined whether the engagement of TCR by immobilized anti-TCR or immobilized class II MHC-peptide complexes generates similar or differential signals during the induction of T cell unresponsiveness. In order to address the initial signalling events induced by TCR occupancy with anti-TCR and class II MHC-peptide molecules, the expression of three critical protein tyrosine kinases (PTK) and their phosphorylation were investigated in the present study using a murine T cell clone (HS17) restricted for IAS and myelin basic protein (MBP (91-103)) peptide. The anergic T cells induced by immobilized IAS-MBP (91-103) complex or anti-TCR (H57) showed differential expression of lck (56 kDa) and Zap-70 (70 kDa) proteins. In both systems, however, the induction of T cell unresponsiveness was accompanied by increased level of fyn (59 kDa) expression. When analysed for the total tyrosine phosphorylation of PTK, anergic HS17 T cells induced by both molecules showed increased phosphorylation associated with only the fyn protein. These results suggest that the signal transduction events induced by immobilized class II MHC-peptide complexes and anti-TCR are distinct, although both can initiate signals that lead to increased fyn expression and phosphorylation. In addition, the present study supports the evidence for the important functional association of fyn protein with direct TCR engagement in T cell signalling.

Animals↗

Mini-laparoscopic cholecystectomy: a cosmetically better, almost scarless procedure.

Laparoscopic cholecystectomy is the most common laparoscopic operation in the world and is accepted as the standard procedure for cholecystectomy. Although use of miniendoscope in diagnosis of gynecological disease has been performed for decades, using a 2-mm mini-laparoscope for cholecystectomy is new. From November 1996 to January 1997, 14 patients (6 men, 8 women; mean age 47 years) with gallbladder stone disease were treated by mini-laparoscopic cholecystectomy at National Taiwan University Hospital, Taipei, Taiwan. The entire procedure was done through four ports (an 11-mm subumbilical working port, a 2-mm subxiphoid video port, one 2-mm mid-clavicular retraction port, and one anterior axillary retraction port). The operative time for these patients ranged from 30 to 150 min, with an average time of 79.29 min. Suturing was not necessary for the three 2-mm wounds. The estimated blood loss was minimal, and no intraoperative transfusions were required. All patients were able to tolerate feeding within 8 h. The average postoperative hospital stay was 1.57 days. Neither complications nor operation-related mortality were seen. In conclusion, mini-laparoscopic cholecystectomy is a feasible and safe procedure with nearly scarless wounds with a much better cosmetic effect, especially for young female patients.

Antibiotic Prophylaxis↗

A logical approach to hepatocellular carcinoma presenting with jaundice.

OBJECTIVE: This prospective cohort study on patients with hepatocellular carcinoma (HCC) presenting with jaundice emphasized the importance of differentiating patients with hepatic insufficiency from patients with obstructive jaundice caused by tumor. SUMMARY BACKGROUND DATA: There are little data in the medical literature on the management of patients with HCC presenting with jaundice. Experience has accumulated mainly from case reports and retrospective studies. METHODS: Data were collected prospectively on 2095 patients with HCC seen over a 12-year period. All patients were investigated with blood tests, abdominal ultrasound, and chest radiography. Endoscopic retrograde cholangiopancreatography-percutaneous transhepatic cholangiography, computed tomography and hepatic angiography were carried out in selected patients. RESULTS: Of the 530 patients who had clinically detectable jaundice, 481 had jaundice due to hepatic insufficiency and 49 patients had obstructive jaundice. Patients with hepatic insufficiency had extremely poor prognosis, and 90% of them died within 10 weeks of first presentation. "Curative" resection, however, was possible in 9 of 49 patients with obstructive jaundice, and histologic analysis showed resectional margin involvement by tumor in 1 patient. In addition, 35 patients were treated with biliary stents to relieve the obstructive jaundice. Supportive treatment only was given to five patients who were considered too terminally ill. The overall survival of patients with HCC with obstructive jaundice was similar to those patients who presented with no clinical detectable jaundice and was much better than those with jaundice due to hepatic insufficiency (log-rank test, p < 0.001). CONCLUSIONS: The prognosis of patients with HCC who presented with jaundice due to hepatic insufficiency was dismal. It is important to identify the patients who had obstructive jaundice because with proper treatment, good palliation and occasional cure are possible.

Adult↗

Cardiac tamponade during transesophageal echocardiography in the patient of circumferential aortic dissection.

A 43-year-old woman, whose physical findings were consistent with Marfan's syndrome, presented with acute chest pain. Transthoracic two-dimensional echocardiography demonstrated dilated ascending aorta with a circular shape intimal flap at the root level. Subsequently, the patient required transesophageal echocardiography (TEE), but during esophageal intubation, the patient developed acute pericardial tamponade which resulted in death in spite of cardiopulmonary resuscitation. Although, some investigators recommend TEE as the first choice of diagnostic method of aortic dissection, hemodynamic stability is very important during TEE study. Therefore, aggressive sedation may be required in the case of circumferential dissection of the ascending aorta to prevent the increases of the blood pressure and the heart rate which suggested an extensive tear of the aortic intima during TEE procedure.

Adult↗

[The preliminary study on prevention and treatment of neonatal jaundice].

OBJECTIVE: The purification and identification of heme oxygenase isoforms (HO-1) and HO-2 from human liver were described and Sn-protoporphyrin (SnPP) was used to inhibit HO-1 activity in order to provide a new method for prevention and treatment of neonatal jaundice. METHODS: Human hepatic microsomal fractions were purified by DEAE-Sephadex A-25 and hydroxylapatite chromatography. The enzyme activities of the two isoforms were detected with and without Snpp. RESULTS: HO-1 was the predominant form with a ratio of 2.4:1 (HO-1:HO-2). The apparent molecular weight of HO-1 and HO-2 on SDS-PAGE was 30,000 and 36,000 under reducing conditions, respectively. The study also showed that HO-1 was the traditional inducible heme oxygenase and HO-2 was a non-inducible heme oxygenase. CONCLUSION: The efficient inhibition effect of SnPP on HO-1 is suggested.

Enzyme Inhibitors↗

Soluble MHC II-peptide complexes induce antigen-specific apoptosis in T cells.

Soluble major histocompatibility (MHC) class II molecules in association with antigenic peptide recognize T cell receptors (TCRs) on CD4+ T cells. Such recognition of MHC II-peptide complexes by T cells in the absence of costimulatory signals is known to induce T cell nonresponsiveness. The present study describes that recognition of TCRs by MHC class II-peptide complexes induces antigen-specific apoptosis in a T cell clone independently of nonresponsiveness. Apoptosis was demonstrated in a murine T cell clone (4R3.9) restricted for IAk in association with a peptide analog of myelin basic protein [MBP(1-14)A4]. A dose- and time-dependent T cell death was observed upon incubation of 4R3.9 T cells with purified IAk-MBP(1-14)A4 complexes. The specificity of T cell apoptosis was shown by incubating 4R3.9 T cells with irrelevant IAs-MBP(90-101) complexes. The DNA fragmentation as a result of apoptosis was demonstrated by agarose gel electrophoresis and by pulsing T cells with BrdU followed by the detection of BrdU-labeled DNA fragments using an antibody enzyme-linked immunosorbent assay. The expression level of two regulatory intracellular proteins, bcl-2 and bax, involved in apoptosis showed a decrease in bcl-2 and an increase in bax with time. Finally, the nuclear shrinkage and chromatin condensation, typical hallmark of apoptosis, have been demonstrated by transmission electron microscopy of complex-treated T cells. Since the T cell clone (4R3.9) used in this study failed to show nonresponsiveness by IAk-MBP(1-14)A4 complexes, our results suggest that apoptosis induced by purified MHC class II-peptide complexes may involve distinct pathways rather than T cell nonresponsiveness. Such antigen-specific apoptosis may have significant clinical relevance in deleting autoreactive T cells in various autoimmune diseases.

Amino Acid Sequence↗

Surgical resection for recurrent hepatocellular carcinoma: prognosis and analysis of risk factors.

BACKGROUND: Hepatocellular carcinoma (HCC) is common in Asian countries, and tumor recurrence is the most common cause of treatment failure after curative resection. Repeated hepatectomy is performed only for selected patients because most patients with HCC also have liver cirrhosis and poor liver function reserve. The purposes of this study were to clarify the outcome of the patients after second hepatectomy for recurrent HCC and to evaluate the prognostic factors after second hepatectomy. METHODS: We used retrospective cohort study to examine the disease-free survival, cumulative survival, and possible prognostic factors for recurrence and death in 59 patients who underwent surgical resection for recurrent HCC at the National Taiwan University Hospital from August 1986 to December 1993. Another 64 patients with unresectable recurrent HCC were used as a historical control group. The survival curves between those patients with resectable HCC and those with unresectable HCC were compared. RESULTS: After resection for recurrent HCC, gender and multiplicity (n > 3) of tumor affect recurrence rate (p = 0.046 and 0.021, respectively), whereas gender, age, and tumor invasiveness affect survival rate significantly (p = 0.024, 0.021, and 0.046, respectively). The survival rate of patients with resectable HCC was significantly better than that of those with unresectable HCC. CONCLUSIONS: For recurrent HCC surgical resection is an effective mode of treatment in selected patients. Whether surgery is better than other modes of treatment in the treatment of resectable recurrent HCC demands further investigation.

Adult↗

Application of murine T-T hybridoma cells to in vitro potency assay of human synthetic peptide vaccines.

Recently, it has been shown that the immunization of mice with an 18 amino acid synthetic peptide corresponding to the third hypervariable region of MHC class II beta chain can induce a specific antibody response against MHC class II molecules, and can be utilized in the prevention and treatment of experimental allergic encephalomyelitis (EAE) [Proc. Natl. Acad. Sci. 1994, 91, 8005-8009]. Based on this finding, a chemically-modified synthetic peptide with the amino acid sequence corresponding to residues of beta 57-76 from human HLA-DR4Dw4 (DR4/1 peptide) is being clinically investigated for the treatment of rheumatoid arthritis in human. The present study describes the development of a novel in vitro potency assay for human HLA-DR4/1 peptide using cloned murine T-T hybridoma cells. Several mouse strains were immunized with the DR4/1 peptide and their lymph node T cell proliferation was measured in the presence of syngeneic APCs and the DR4/1 peptide. T cells isolated from the peptide primed-B10. PL mouse strain, which showed the highest recall response in this assay, were fused with BW5147 lymphoma cells to generate DR4/1 peptide-specific T-T hybridoma clones. Cloned hybridoma cells were characterized for peptide specificity and MHC class II restriction, and used to monitor the biological activity of various DR4/1 peptide preparations. The potency of peptide batches were assessed by measuring the IL-2 secretion of cloned T-T hybridoma cells upon TCR engagement in an antigen-specific manner. The quantitative detection of IL-2 was performed by measuring [3H]thymidine incorporation of HT-2 cells or directly by ELISA. These results demonstrate that peptide-specific murine T-T hybridoma clones can be successfully utilized to monitor biological activity of synthetic peptides by measuring T cell-mediated immunological responses. Development of such in vitro potency assay for synthetic peptides may have broad applications for vaccines related to immunological disorders.

Animals↗

A prospective study on the use of water-soluble contrast follow-through radiology in the management of small bowel obstruction.

BACKGROUND: The purpose of this prospective study was to determine the value of water-soluble contrast follow-through radiology in predicting the outcome in patients with small bowel obstruction. METHODS: Patients with clinical and radiological evidence of small bowel obstruction were selected according to pre-set criteria. A water-soluble contrast follow-through examination using 76% urografin was carried out within 24 h of hospital admission. The result was interpreted as 'significant obstruction' if the contrast failed to reach the caecum in 4 h or if there was a clear cut-off in the gastrointestinal tract. The result was interpreted as 'insignificant obstruction' if the contrast reached the caecum within 4 h. The surgeon was blinded to the result of the contrast examination in the patient management, and the decision to operate was based entirely on conventional clinical grounds. RESULTS: Fifty-one patients in an 18 month period underwent the contrast examinations. Thirty-four patients (67%) had previous abdominal operations. The results showed that significantly more patients who had 'significant obstruction' on contrast radiology required surgery to relieve the intestinal obstruction (17/19) than those who had "insignificant obstruction' (1/32; Fisher's exact test, P < 0.0001). This difference was found to be significant in both patient subgroups: patients with or without previous abdominal operation. There was no major morbidity or mortality related to the contrast radiology procedure. CONCLUSIONS: Urografin follow-through examination is a safe procedure; using 4 h as the cut-off it is highly predictive of the outcome in small bowel obstruction in patients with or without previous abdominal operation.

Abdomen↗

Hemosuccus pancreaticus from a splenic artery pseudoaneurysm: an unusual cause of upper gastrointestinal bleeding.

Hemorrhage through the pancreatic duct into the duodenum, so called "hemosuccus pancreaticus", is a rare cause of gastrointestinal bleeding with diagnostic difficulties. We report a 60-year-old man with recurrent upper gastrointestinal bleeding due to rupture of a splenic artery pseudoaneurysm into the pancreatic duct. Initial upper gastrointestinal endoscopy failed to identify the site of the hemorrhage. Abdominal computed tomography disclosed a cystic mass containing a well-enhanced spherical area at the pancreatic tail. Arterial blood flow was demonstrated in the lesion by Doppler ultrasound. Celiac angiography demonstrated a saccular pseudoaneurysm arising from the splenic artery. Bleeding from the ampulla of Vater located in a big duodenal diverticulum was found on repeat endoscopy. Surgical resection of the pseudoaneurysm with distal pancreatectomy and splenectomy was successfully performed. The patient remained symptom-free 5 months after the operation. Hemosuccus pancreaticus, although rare, remains important in the differential diagnosis of upper gastrointestinal bleeding of obscure origin.

Aneurysm, False↗