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Biomedical subjects

J Wong

Publications and source records attributed to J Wong.

At least 541 records · Page 30Linked to original sources
PubMed1989

Immediate reconstruction of pharyngoesophageal defects. Preference or reference.

In this era of development in reconstruction, interest in searching for the most appropriate procedure for replacing the pharyngoesophageal defect is intense. The type of defect, depending on the level of invasion by the cancer, should be classified as partial pharyngeal, circumferential pharyngeal, or pharyngoesophageal. Within each class, the surgeon can have his preference for a reconstructive procedure according to available expertise and familiarity. In our series of 97 patients with pharyngoesophageal defects resulting from resection of laryngeal, hypopharyngeal, and cervical esophageal cancers, the patch-on pectoralis major myocutaneous flap, the tubed pectoralis major myocutaneous flap, and the stomach were used for the three types of defects, respectively. Mortality and morbidity, while kept at an acceptable level, appear to rise as the complexity of the procedure increases. This supports the argument that the reconstructive method should be selected with reference to the type of defect, which is in turn dependent on the site and behavior of the tumor. The reconstructive procedure is to fit the defect, and not vice versa.

Adult↗
PubMed1989

Anastomotic leakage: an avoidable complication of Lewis-Tanner oesophagectomy.

Data were collected prospectively from 159 patients undergoing Lewis-Tanner oesophagectomy for carcinoma of the lower two-thirds of the oesophagus and analysed with regard to anastomotic leakage. The 30-day mortality rate was 3.8 per cent and none of these deaths was due to anastomotic leakage. In hospital, mortality was 7.5 per cent. Six patients (3.8 per cent) had evidence of a leak. In four patients this was from the suture line, but in the remaining two it was due to patches of gangrene in the fundus of the transposed stomach and was separate from the anastomosis. Two patients died with an unhealed leak. Anastomotic leaks were minor in three instances and healed with conservative treatment but the fourth required exploration. Gangrene of the oesophageal substitute resulted in gross leakage with mediastinitis and required exploration in both cases. An apparent predisposing cause was evident in five of the six cases with leakage and some of these might have been avoidable. Transthoracic oesophagectomy can be performed with acceptably low mortality and leak rates and may therefore be considered as the treatment of choice for most patients with oesophageal cancer.

Adenocarcinoma↗
PubMed1989

A comparison of transhiatal and transthoracic resection for carcinoma of the thoracic esophagus.

Among 210 patients who underwent resection for carcinoma of the middle and lower thirds of the thoracic esophagus, 38 were selected for a transhiatal nonthoracotomy approach. Compared with the 172 resections through a transthoracic route, there was no difference in age, sex, location, and differentiation of tumor. In the transhiatal group, excessive bleeding and tumor perforation as a result of blunt dissection each occurred in seven patients (18 percent). Recurrent nerve injury was noted in five patients (13 percent), but tracheal damage and chylothorax were avoided. The incidences of operative mortality and postoperative complications were similar in both groups. Survival by life-table analysis showed the transhiatal approach to be inferior to the transthoracic one. This nonrandomized study did not answer the question as to whether respiratory complications were lessened but did show a significant number of intraoperative complications when the transhiatal approach was used. The results indicated that survival was better when resection was performed through the chest.

Aged↗
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

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

Exploratory laparotomy alone in carcinoma of the oesophagus and gastric cardia.

A retrospective analysis of 453 patients with carcinoma of the oesophagus and gastric cardia was carried out in order to identify the incidence, operative findings, and outcome of patients who underwent laparotomy only without a definitive procedure. Of 343 patients who underwent surgery, 81% had their tumours resected and 15% had a bypass procedure. The remaining 14 patients (4%) had an exploratory laparotomy alone. The incidence of performing a laparotomy only was 1.5% for patients with carcinoma of the thoracic oesophagus but was 14% for patients with tumour of the gastric cardia (P less than 0.001). The reasons for exploration alone in these 14 patients were advanced local disease (12), bilobar liver metastases (seven), extensive abdominal lymph node metastases (seven), peritoneal seedlings (six) and malignant ascites (four). All except one patient had more than one feature which led to the decision of exploration only. As the overall incidence of exploratory laparotomy was low, it would not be appropriate for all patients to undergo exhaustive and expensive investigations. Surgical exploration continues to be the only reliable method to determine the actual extent of disease and whether a definitive procedure is possible. However, patients with cancer of the cardia with clinical features of advanced disease might warrant additional evaluations as the incidence of exploratory laparotomy alone with minimal prior investigation is relatively high.

Adenocarcinoma↗
PubMed1989

Cross-resistance of Pseudomonas aeruginosa to ciprofloxacin, extended-spectrum beta-lactams, and aminoglycosides and susceptibility to antibiotic combinations.

The susceptibilities of 270 clinical isolates of Pseudomonas aeruginosa from diverse sources (82 burn patients, 76 cystic fibrosis [CF] patients, and 112 other sources) to ciprofloxacin and three other quinolones, nine extended-spectrum beta-lactams, and three aminoglycosides were determined by an agar dilution method in cation-supplemented Mueller-Hinton medium. Ciprofloxacin, ceftazidime, imipenem, and aztreonam were the most active. MICs for burn isolates were consistently higher than those for other isolates for most antibiotics, whereas those for CF strains were consistently lower. Multidrug resistance to aminoglycosides and beta-lactams occurred in 21% of the burn isolates, 2.6% of the CF isolates, and 8.9% of the other isolates. Ninety percent of these strains remained susceptible to ciprofloxacin. Seven percent of the isolates were resistant to ciprofloxacin (MIC, greater than or equal to 2 micrograms/ml). Concurrent resistance to ciprofloxacin and beta-lactams or aminoglycosides was rare (1.8 to 4%). Analysis by Spearman rank correlation revealed a high degree of correlation of MICs among antibiotics within the same class, except for imipenem. An inoculum effect was observed for all antibiotics between 10(6) and 10(4) CFU (P less than 0.05), with those for piperacillin and cefoperazone being the most pronounced (16-fold and 8-fold differences, respectively), and was least apparent for the quinolones, aminoglycosides, imipenem, and aztreonam (twofold differences). Selected strains for which there were high MICs of ciprofloxacin (greater than or equal to 1 micrograms/ml) were tested against ciprofloxacin in combination with other agents in a checkerboard agar dilution assay. Synergistic (summated fractional inhibitory concentration, </=0.5) interactions at clinically achievable concentrations were most frequent with mezlocillin (33%), piperacillin (21%), and (7.6%), aztreonam (3.7%), and the aminoglycosides (3.7%). Antagonism (summated fractional inhibitory concentration, >/= 4) was observed in only one instance (with gentamicin).

Aminoglycosides↗
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

Short loop adrenocorticotropin (ACTH) feedback after ACTH-(1-24) injection in man is an artifact of the immunoradiometric assay.

A recent report measured a decrease in plasma ACTH concentration by immunoradiometric assay (IRMA) during infusion of ACTH-(1-24) in humans. It was concluded that this decrease in ACTH concentration was due to short loop ACTH autoregulation. The present study demonstrates that the decrease in ACTH concentration measured by IRMA was due to an artifact of the IRMA. We injected 250 micrograms ACTH-(1-24), iv, into five normal male volunteers after overnight 2.5-g metyrapone administration. The ACTH concentration measured by IRMA decreased from 59.6 +/- 9.7 pmol/L before to 4.8 +/- 2.0 pmol/L 1 min after ACTH-(1-24) injection. The ACTH concentration measured by IRMA increased thereafter in a mirror image of the decline in ACTH-(1-24) measured by RIA. Addition of ACTH-(1-24) to plasma in vitro resulted in a decrease in the ACTH concentration measured by IRMA which was of similar magnitude to that observed in vivo. ACTH-(1-24) infusion in vivo or addition to ACTH-(1-39)-containing plasma in vitro decreased ACTH-(1-39) measured by IRMA by binding to N- but not C-terminal antibody without forming a detectable sandwich complex. We conclude that although ACTH short loop feedback may exist, it cannot be detected after ACTH-(1-24) injection with the use of a two-site IRMA.

Adrenocorticotropic Hormone↗
PubMed1989

Changes in cytoskeletal gene expression affect the composition of regenerating axonal sprouts elaborated by dorsal root ganglion neurons in vivo.

The effect of a change in neurofilament (NF) and tubulin gene expression on the elongation of axonal sprouts by adult rat sensory neurons was examined. Distal sciatic nerve crush axotomy was used to initiate changes in cytoskeletal gene expression in lumbar dorsal root ganglion (DRG) neurons. In situ hybridization of DRG neurons with 35S-labeled cDNA probes revealed a significant reduction in the level of mRNAs for the low-molecular weight-NF protein and a significant increase in the level of beta tubulin mRNAs by 2 weeks after axotomy. A novel modification of the axonal transport paradigm was used to examine the biochemical composition of the regenerating axons formed by primed and unprimed DRG neurons. Primed neurons (which had sustained a crush axotomy of the distal sciatic nerve 2 weeks earlier) and unprimed (normal) neurons were labeled by microinjection of 35S-methionine and then stimulated to regenerate axons by a crush located very close to the DRG. In this paradigm, axonal sprouts that formed after the proximal crush axotomy incorporated radiolabeled, slow axonally transported proteins as they elongated. Fluorographs of SDS-PAGE revealed that the regenerating axonal sprouts of primed DRG cells incorporated and conveyed significantly less labeled NF protein than did the regenerating axons of unprimed DRG neurons. Electron microscopy revealed that the regenerating axonal sprouts of primed DRG cells contained numerous microtubules but very few identifiable NFs compared with the regenerating sprouts of unprimed DRG neurons.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗
PubMed1989

Stability of esmolol hydrochloride and sodium nitroprusside in intravenous admixtures.

The stability of esmolol hydrochloride and sodium nitroprusside in an admixture containing both drugs was studied. Solutions containing sodium nitroprusside in a final concentration of approximately 200 micrograms/mL and esmolol hydrochloride in a final concentration of 10 mg/mL in 5% dextrose injection were prepared in a 250-mL volumetric flask. The flask was wrapped with a light-protective cover, stored at ambient room temperature (15-30 degrees C), and protected from light. All experiments were conducted in triplicate with samples taken at 0, 2, 4, 8, and 24 hours. Testing included measurement of pH and absorbance at 400 and 600 nm. High-performance liquid chromatography was used to measure esmolol hydrochloride and sodium nitroprusside concentrations. No changes were observed in the physical appearance, pH, or absorbance of the admixtures. Neither the esmolol hydrochloride nor the sodium nitroprusside concentrations varied by more than 4% during the study. Under the conditions studied, esmolol hydrochloride is compatible with sodium nitroprusside in an admixture containing both drugs.

Adrenergic beta-Antagonists↗
PubMed1989

Axotomy-induced changes in the expression of a type III neuronal intermediate filament gene.

The effect of axotomy on the expression of the 57 kDa neuronal intermediate filament (IF) protein in adult rat dorsal root ganglion (DRG) neurons was examined. This IF protein is known to have an exclusively neuronal localization but is considerably more limited in its distribution in the nervous system than the neurofilament (NF) triplet proteins. The 57 kDa neuronal IF protein is similar (and perhaps identical) to the protein "peripherin" and is known to be the product of a Type III IF gene. Since the down-regulated expression of NF proteins (products of type IV IF genes) has been well established, it was of interest to determine whether the novel 57 kDa IF protein was regulated in a similar or different manner from that of the NFs in axotomized neurons. In vitro pulse-labeling of DRGs with 35S-methionine: cysteine followed by 2-dimensional gel electrophoresis/fluorography revealed that the synthesis of the 57 kDa neuronal IF protein was increased 2 weeks after sciatic nerve crush. Immunocytochemical studies using a polyclonal antibody to the 57 kDa neuronal IF protein showed that the immunodetectable levels of this protein increased in DRG neurons after peripheral axotomy. In the normal DRG, staining was localized almost exclusively to small-sized neurons. At 2 weeks after axotomy, however, large- and medium-sized neurons also became immunoreactive; in addition, the overall level of staining in the DRG was greater than normal. Quantitative analysis of in situ hybridizations of DRG neurons with a 35S-labeled cDNA probe specific for the 57 kDa neuronal IF protein revealed a significant increase in the level of 57 kDa IF mRNA in the large-sized (greater than 1000 microns2) neurons 2 weeks after axotomy; the level of 57 kDa IF mRNA in the small neurons was not different from normal at that time. Finally, using a newly developed paradigm for examining the composition of regenerating axons by axonal transport, we determined that significant amounts of the 57 kDa neuronal IF protein were conveyed into the regrowing axonal sprouts of DRG neurons. When DRG neurons were conditioned by a previous axotomy (a crush axotomy of the distal sciatic nerve 2 weeks earlier) and then stimulated to regenerate axons by a second crush axotomy located very close to the DRG, the regenerating sprouts incorporated and conveyed significantly more 57 kDa IF protein by slow axonal transport than did those elaborated by unprimed DRG neurons.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗
PubMed1989

Reexploration for complications after esophagectomy for cancer.

Among 316 patients who underwent resection for esophageal cancer, 23 required reexploration for complications and 10 died. The commonest reason for reexploration was leakage (eight patients). Development of leakage necessitating reexploration was associated with a hospital mortality rate of 75%. Other reasons for reexploration were postoperative bleeding (n = 7), chylothorax (n = 2), burst abdomen (n = 2), diaphragmatic herniation (n = 1), bile peritonitis (n = 1), bowel gangrene (n = 1), and tracheal perforation (n = 1). Definite or presumed technical error could be identified in 18 of the 23 patients requiring reexploration and indicated that the majority of reexplorations were for complications that appeared to be potentially avoidable. When reexploration became necessary, early intervention offered the best chance of survival.

Adult↗
PubMed1989

Surgical revascularisation for diffuse CAD--an experience in 116 cases.

There were 94 male and 22 female, age ranges 32 to 71 years with a mean age of 54 years. All of them had angina pectoris and strong positive stress test inspite of maximum medical treatment. All had severe triple vessel disease including (12 (10%) had critical left main stem lesion, 68 (52%) were diabetic and hypertensive, 51 (44%) had myocardial infarct with 16 (14%) of them showing global hypokinesia of ejection fraction 30%. The average grafts per patient was 3.8 Seventy-nine patients (68%) and RCA endarterectomy; 19 (16%) had right and left coronary endarterectomy and 18 (15%) had left coronary artery endarterectomy. One-hundred and three (86%) were reconstructed with saphenous vein graft. 13 (12%) with IMA grafts. There was no operative mortality. Two hospital deaths and two late deaths occurred in those patients who had very poor left ventricular function. The perioperative infarct rate was 2.7%. All patients were followed-up regularly at 2 weeks, 3 months, 6 months, postoperatively. The mean follow-up was 18 months ranging 10 to 43 months. Clinically over 95% are free from angina pectoris with improved effort tolerance. We conclude that endarterectomy with patch angioplasty is an effective and safe procedure in treating Diffuse Coronary Artery Disease which cannot be treated by bypass alone. The incidence of Diffuse Coronary Artery Disease is likely to increase in the future as the percutaneous balloon angioplasty is becoming more widely practised and Re-do CABG patient would come to surgery at a more advanced state of the disease.

Adult↗