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Biomedical subjects

S T Fan

Publications and source records attributed to S T Fan.

At least 235 records · Page 13Linked to original sources
PubMed1990

Severe acute cholangitis: the role of emergency nasobiliary drainage.

The role of emergency endoscopic nasobiliary drainage (NBD) in the management of severe acute cholangitis was evaluated by comparing the outcome of 15 patients who underwent the procedure as an initial treatment with that of 20 patients who underwent emergency surgery. Biliary sepsis was successfully controlled without complication in all 15 patients by the insertion of a 7F nasobiliary catheter through a limited papillotomy. Subsequent definitive elective treatment included endoscopic stone clearance (n = 6), common duct exploration (n = 8), and bili-enteric reconstruction (n = 1). Among the 20 patients who had surgical treatment, cholecystectomy (n = 11), cholecystostomy (n = 1), and transhepatic intubation (n = 1) were done in addition to common duct exploration. Although patients undergoing endoscopic NBD were significantly older (75.3 years vs 60.1 years; p less than 0.05) and more jaundiced (total bilirubin, 120.3 mmol/L vs 70.4 mmol/L; p less than 0.05), comparable morbidity (40% vs 65%) and mortality (6.7% vs 20%) was observed. Initial endoscopic NBD provides a safe and effective therapeutic option for the management of fulminant biliary sepsis. Among patients with complicated ductal anatomy, endoscopic NBD should first be attempted because, when successful, definitive reconstruction may be performed on an elective basis. The value of its routine application for all patients, however, remains to be validated by further clinical studies.

Acute Disease↗
PubMed1989

Sufficiency of the CD8+ T cell lineage to mount an effective tumoricidal response to syngeneic tumor-bearing novel class I MHC antigens.

The origins of "help" in rejection of syngeneic tumors by the CD8 T cell lineage was examined with a model tumor inappropriately expressing novel class I MHC and subject to cytolytic T cell (CTL)-mediated rejection. The requirement for CD4+ Th cells to induce CD8+ CTL effectors in vivo was investigated by using C3H mice selectively depleted of either CD4+ or CD8+ T cells. Rejection of the tumor was vigorous and indistinguishable from normal mice after depletion of CD4+ T cells in vivo. In contrast, in CD8+ T cell-depleted mice tumors grew progressively, confirming that T cells of the CD8+ lineage are required for a tumoricidal immune response, and cells of this lineage are sufficient for a primary response. Taken together, these results demonstrate that, in the absence of CD4+ T cells in vivo, unprimed cells of the CD8+ lineage are fully competent to mount an effective CTL immune response to syngeneic cells expressing novel class I Ag, consistent with the concept that only T cells with class I recognition specificity may be required to satisfy the need for both help and effector functions in the response.

Animals↗
PubMed1989

Evaluation of central venous catheter sepsis by differential quantitative blood culture.

The accuracy of differential quantitative blood culture in the diagnosis of central venous catheter sepsis was evaluated in 24 parenterally-fed patients in whom catheter sepsis was suspected. The pour-plate quantitative culture technique was performed immediately before removal of the catheter on blood drawn through the central venous catheter and a peripheral vein. If bacterial colonies in the catheter blood specimen were sevenfold more frequent than identical bacterial colonies in the peripheral blood specimen, the test was considered positive and indicative of catheter sepsis. Catheter-tip culture identified 9 of the 24 patients as positive for catheter sepsis. A positive differential quantitative blood culture result was found for seven of the nine infected catheters. Sensitivity of this test was 77.8%, specificity was 100%, and overall accuracy was 91.7%. It is concluded that differential quantitative blood culture is a reliable method for the exclusion of catheter sepsis.

Bacterial Infections↗
PubMed1989

Urgent biliary decompression after endoscopic retrograde cholangiopancreatography.

Acute cholangitis complicating diagnostic endoscopic retrograde cholangiopancreatography (ERCP) is potentially fatal. Among 323 consecutive patients with proved biliary obstruction, 21 (7 percent) developed acute cholangitis after examination. Four patients underwent emergency surgery for the control of sepsis with two deaths. Of the 21 parameters chosen for evaluation, malignant obstruction, fever (higher than 37.5 degrees C) within 72 hours before the procedure or when afebrile, and an increased aspartate transaminase level of 70 IU or more were the independent predictive factors identified by multivariate analysis. An increased temperature should be regarded as an absolute contraindication to examination unless followed by immediate ductal drainage. Since the risk of septic complications is minimal when none of the risk factors are present, routine urgent biliary decompression after ERCP is probably unnecessary for these selected patients. For patients with malignant obstruction or other risk factors, early elective surgical drainage is advisable. When surgery is not feasible, nonoperative drainage of the obstructed biliary system as a preventive measure might be considered.

Acute Disease↗
PubMed1989

Pancreatic phlegmon: what is it?

In a retrospective study of 264 patients with acute pancreatitis, 22 were identified as having phlegmon by combined radiologic and clinical criteria. The radiologic criteria consisted of demonstration of abnormal lesion on computed tomography scan which was composed of masses of mixed density, free of extraluminal gas and lacking a well-defined wall. The clinical criteria was that the clinical course was free of sepsis. Half of the group thus identified had severe pancreatitis as defined as having three or more poor prognostic signs. Fever, leukocytosis, and serum amylase elevation persisted for a longer period than usual. Complication was infrequent but the lesion could persist for 3 to 4 months without producing symptoms. This is a relatively benign condition and surgery should be avoided.

Abscess↗
PubMed1989

Pre-operative parenteral nutrition in patients with oesophageal cancer: a prospective, randomised clinical trial.

A prospective randomised clinical trial was conducted to examine the efficacy of 2 weeks pre-operative parenteral nutrition (PPN) for the prevention of complications following surgery for oesophageal cancer. Forty patients were studied, the diet of twenty being supplemented by pre-operative parenteral nutrition. There were no significant differences in age, nutritional status, tumour staging and histology between the two groups of patients. The use of PPN resulted in a significant gain in body weight and nitrogen but failed to produce an overall reduction in post-operative morbidity and mortality rates. However patients receiving PPN exhibited two types of changes in serum albumin levels. Those with a fall in serum albumin levels associated with an increase in body weight (indicating an expansion of extracellular volume) had a significantly higher incidence of post-operative pulmonary complications than the group exhibiting a rise in serum albumin levels concomitant with increase in body weight. These data suggested that two weeks PPN might not be adequate in certain patients and a longer period of PPN is required. They also show no clinical benefit from the routine use of pre-operative parenteral nutrition in all patients, but do not exclude benefit in selected groups.

Journal Article↗
PubMed1989

A multicentric study of netilmicin once daily versus thrice daily in patients with appendicitis and other intra-abdominal infections.

This multicentric, randomized, double-blind trial compared the efficacy and safety of netilmicin, 4.5 mg/kg od and 1.5 mg/kg tid, in patients with intra-abdominal infections. Of 114 patients enrolled, 57 patients (mean age 40.3 years) in the od group and 55 (mean age 36.8 years) in the tid group were evaluated for efficacy; 58 and 56 patients in corresponding groups were evaluated for safety. Among those evaluated for efficacy were 12 od-treated and 11 tid-treated patients with documented septicaemia, and 32 and 30 patients of respective groups with polymicrobial infections. Initially, 86 and 81 netilmicin-susceptible causative microorganisms were isolated in corresponding groups. Of these pathogens, 55% in the od group and 62% in the tid group were Escherichia coli. Daily dosage of netilmicin ranged from 3.70 to 4.71 mg/kg (mean 4.50) for the od group and from 3.06 to 4.76 mg/kg (mean 4.46) for the tid group. Duration of netilmicin therapy ranged from six to 13 days (mean 8.7 days) for od-treated patients and from seven to 16 days (mean 8.8 days) for tid-treated patients. Concomitant metronidazole was administered to 41 patients of the od group and 34 of the tid group; one patient in the tid group received clindamycin. Clinical and bacteriological responses were assessed, and peak and trough serum netilmicin levels were measured periodically, during therapy. Laboratory tests, including determinations of serum creatinine and blood urea nitrogen values, were performed throughout the trial. A clinical cure was achieved in 57/57 od-treated patients and 54/55 tid-treated patients; treatment failed in one tid-treated patient (1/55). In od and tid groups, 86/86 and 80/81 netilmicin-susceptible pathogens initially isolated were considered to be eliminated, respectively; one isolate (Esch. coli) persisted in the tid group. Mean peak serum netilmicin concentration in the od group was approximately two-fold greater than that in the tid group; mean trough serum netilmicin concentrations were similar for the two groups. Adverse reactions were limited to mild pain at the site of netilmicin administration in several patients in each treatment group. Netilmicin od and tid (alone or in combination with metronidazole) were similarly efficacious in the treatment of patients with appendicitis and other intra-abdominal infections caused by netilmicin-susceptible pathogens. Both dosage regimens of netilmicin were safe and well tolerated.

Abdomen↗
PubMed1989

Spontaneous ruptured hepatocellular carcinoma. An appraisal of surgical treatment.

Spontaneous rupture with bleeding is not an infrequent complication of hepatocellular carcinoma (HCC). From May, 1972 to January, 1987, 56 symptomatic patients with ruptured HCC were managed by plication of the lesion (2 patients), ligation of either the common hepatic artery, CHAL, (39 patients), or selectively, the arterial branch supplying the tumor-bearing lobe of liver, SHAL, (8 patients), and hepatic resection, HR, (7 patients). Effective hemostasis was achieved in 68.1% of patients with the use of hepatic artery ligation (HAL). SHAL provides a comparable control of bleeding but no demonstrable reduction of postoperative organ failure when compared with CHAL. The operative treatment employed had no influence on either the postoperative rates of morbidity, mortality, or survival. However, the rate of hospital mortality was high among the four patients who had emergency anatomical lobectomy, despite the absence of severe cirrhosis. Hepatic artery ligation, either CHAL or SHAL, is a satisfactory definitive hemostatic measure for unresectable HCC when it ruptured. SHAL is probably preferred to routine emergency HR for patients with potentially resectable lesions. Nonetheless, for selected patients with easily accessible lesions, segmentectomy or subsegmentectomy could still be contemplated in the absence of severe cirrhosis.

Carcinoma, Hepatocellular↗
PubMed1989

Electrohydraulic lithotripsy for biliary stones.

Electrohydraulic lithotripsy was applied in 10 patients with biliary stones which were difficult to extract with the use of choledochoscopy and basket. The difficulties encountered included large impacted stones in the Hartmann's pouch, intrahepatic ducts and lower end of common bile-duct, stones situated at the orifice of acutely angulated segmental bile-ducts and stones impacted just behind strictures. With the use of electrohydraulic lithotripsy all the stones were disintegrated and removed. The only complication was transient haemorrhage from ductal injury. It is concluded that electrohydraulic lithotripsy is a useful adjunct to the choledochoscopic removal of biliary stones.

Adult↗
PubMed1989

Bleeding gastric ulcer: a prospective evaluation of rebleeding and mortality.

Clinical laboratory and endoscopic data were collected prospectively in 268 patients with bleeding gastric ulcer who were admitted between September 1985 and November 1987. There were 22 deaths, giving a hospital mortality rate of 8.2%. Surgery was undertaken in 68 patients (25.4%) with a mortality rate of 17.6% (11.8% at 30 days). There was one fatality in 104 (1.0%) patients less than or equal to 60 years compared with 21 deaths (12.8%) in patients greater than 60 years (P less than 0.001). Cirrhosis (P less than 0.01), malignant disease (P less than 0.03), chronic obstructive airways disease (P less than 0.02), congestive cardiac failure (P less than 0.02) and ischaemic heart disease (P less than 0.08) were each associated with an increased risk of mortality. Outcome in patients greater than 60 years was related to systolic blood pressure at admission (P less than 0.03), haemoglobin (P less than 0.02), serum bilirubin (P less than 0.02), and total transfusion requirements (P less than 0.001). For ulcers less than or equal to 1 cm, 1- less than or equal to 2 cm, greater than 2 cm in size, mortality rates were 1.9%, 11.4% and 18.0%, respectively. Initial endoscopy findings of a visible vessel, fresh blood, or active spurting/oozing haemorrhage were associated with rebleeding rates necessitating emergency surgery of 30.0%, 36.4% and 40.0%, respectively. There was no evidence of rebleeding in 187 patients (79.9%) managed conservatively and only five patients (2.7%) in this group succumbed, whereas rebleeding did occur in 47 patients (20.1%) with 13 subsequent deaths (27.7%; P less than 0.001). In patients greater than 60 years the presence of endoscopic stigmata of recent haemorrhage should lead to early consideration of therapeutic endoscopy and/or early surgery, particularly for ulcers greater than 1 cm in size.

Adolescent↗
PubMed1989

Prediction of severity of acute pancreatitis: an alternative approach.

Admission laboratory data of 203 patients suffering from acute pancreatitis were analysed to search for a simpler method of prediction of severity than the traditional multifactor prognostic scoring system. By discriminant analysis, admission serum urea and plasma glucose were identified to be factors with independent significance in predicting severity. If the presence of either factor higher than the cutoff point (urea greater than 7.4 mmol/l, glucose greater than 11.0 mmol/l) was considered as an indication of severe disease, then the sensitivity of this method was 75.0%, specificity 80.3% and the accuracy 79.3%. The predictive ability of this method was comparable with the Glasgow multifactor scoring system when the latter was also used to grade severity of our patients. It has the advantage, however, of simplicity and the ability of predicting severity at the time of admission.

Acute Disease↗
PubMed1989

Somatostatin in the treatment of acute pancreatitis: a prospective randomised controlled trial.

A prospective study was carried out to evaluate the efficacy of somatostatin in the treatment of acute pancreatitis. Seventy one patients were randomised to control (h = 36), or to the somatostatin group (h = 35) who received somatostatin 100 micrograms/h after a 250 microgram bolus for the first two days. The following were compared in the two groups on admission and two days later: laboratory tests of prognostic significance, severity of pancreatitis, and also morbidity and mortality. Of the nine laboratory tests compared, the white blood cell count, lactate dehydrogenase, and urea concentrations were significantly lower in the somatostatin group two days after admission. Severity of pancreatitis after hospitalisation increased in fewer patients given somatostatin (NS). There was a trend toward fewer complications, especially local, in the somatostatin group. Mortality in both groups was low. Somatostatin appeared to reduce the local complications of acute pancreatitis. A larger trial is necessary to show its beneficial effect conclusively.

Acute Disease↗
PubMed1989

Evaluation of recurrent pyogenic cholangitis with CT: analysis of 50 patients.

The use of computed tomography (CT) was investigated in 50 patients with recurrent pyogenic cholangitis, 22 of whom had undergone prior choledochoenterostomy or sphincteroplasty. A spectrum of pathologic features was noted, including intrahepatic ductal dilatation (n = 50), common duct dilatation (n = 34), strictures (n = 11), intrahepatic calculi (n = 37), common duct calculi (n = 15), pneumobilia (n = 26), segmental atrophy (n = 18), and splenomegaly (n = 7). Unilobar disease existed in 14 patients. The left lateral segment was predominantly affected, with ductal dilatation (n = 23) and segmental atrophy (n = 13). During acute exacerbation, additional manifestations were observed: ductal wall enhancement (n = 4), segmental parenchymal enhancement (n = 9), hepatic abscess (n = 9), and biloma (n = 2). CT enables sensitive, complete evaluation of this disorder. It is valuable when results of ultrasonography are non-diagnostic and for planning hepatic resection, evaluating associated mass lesions, and guiding complex interventional procedures.

Adult↗
PubMed1989

Tuberculosis of the bile duct: a rare cause of biliary stricture.

The first case of biliary stricture due to tuberculous involvement of bile duct is presented. The diagnosis was established by choledochoscopic biopsy through a dilated percutaneous transhepatic biliary tract. Surgical bypass was impossible in this situation and endoprosthesis successfully relieved the biliary obstruction.

Bile Duct Diseases↗
PubMed1988

Clonal analysis of mechanisms of murine T helper cell collaboration with effector cells of macrophage lineage.

The molecular basis and genetic restrictions of collaboration between Th cells and macrophages (Mo) and the numbers of types of collaboration in the Ag-specific cellular immune response were analyzed. Using the response of cloned Ag-specific T cells we examined the mechanisms of induction of the macrophage procoagulant response. Two generic types of collaboration were identified. One was mediated by the lymphokine monocyte procoagulant inducing factor (MPIF) and the second mechanism was by apparent contact collaboration. The lymphokine MPIF was produced by T cells and cloned CD4+ T cells after specific Ag stimulation. Cloned CD8+ cells, most of which also exhibited cytolytic activity, produced little MPIF. There was no evident restriction of the response of Mo of different MHC or background genes. In the second collaborative pathway a subset of CD4+ cloned Th cells were able to directly collaborate by an apparent contact mechanism with Mo for the procoagulant response. There was no correlation of this latter capacity with MPIF production. In addition abrogation of protein synthesis and lymphokine production by Ag-driven clones did not abrogate the direct cell association type of collaboration. Both forms of collaboration were equally efficient across MHC incompatibility barriers and different genetic background. We conclude that there are two independent and parallel Th:Mo collaborative pathways for Ag-driven responses in this limb of the cellular immune response, i.e., a MPIF lymphokine pathway and a contact pathway, and that there are quantitative and qualitative clonal differences in the use of these two pathways. We suggest that the existence of multiple parallel pathways for cellular collaboration may occur more widely in the Th:Mo limb of the immune response in respect to other Mo effector molecules and should be explored to understand the orchestration of this limb of the immune response.

Animals↗
PubMed1988

Intra-operative localization of bleeding small intestinal lesions.

We prospectively studied 12 patients to compare fibreoptic enteroscopy and methylene blue injection through superselectively prepositioned angiographic catheters in intra-operative localization of bleeding small intestinal lesions. Four patients were excluded because the lesions were easily detected by gross examination. Eight patients were subjected to study by these two methods. As methylene blue injection required a positive angiography, it was possible only in five patients. In two of these five patients, non-bleeding lesions were present outside the intestinal segments localized by this method. Enteroscopy was simple, accurate and reliable in seven patients. Complete enteroscopy was impossible in one patient with advanced lymphoma because the intestine and its mesentery were matted together. Fortunately, the bleeding ulcers were still within the reach of the endoscope. Enteroscopy localized bleeding small intestinal lesions more exactly than methylene blue injection so that the length of gut resection could be shorter. We, therefore, conclude that enteroscopy is the better intra-operative localization procedure.

Adolescent↗