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Biomedical subjects

S T Fan

Publications and source records attributed to S T Fan.

At least 271 records · Page 15Linked to original sources

Intra-operative fibreoptic enteroscopy for bleeding lesions in the small intestine.

Twenty-five patients with gastrointestinal bleeding proved to have lesions in the small intestine. Intra-operative fibreoptic enteroscopy was performed on seven patients, in six patients through the anus and in one patient through an enterotomy and the anus. The indications for fibreoptic enteroscopy were inability to find the lesions in the 3 patients, multiple small lesions in 3 patients and to rule out suspicious pathology in the jejunum shown on a small bowel enema in a patient with ileal ulcers. In all instances, the fibreoptic enteroscopy was useful in localizing lesions, in detecting additional lesions and in ruling out the suspicious lesions. It can be performed easily and is safe. No complication developed from its use in this series.

Endoscopy↗

Combined topical povidone-iodine and systemic antibiotics in postappendicectomy wound sepsis.

Three hundred and fifteen patients with appendicitis were randomized into two groups. One group received pre-operative systemic gentamicin and metronidazole while the other group received 1 per cent topical povidone-iodine solution in addition to the antibiotics. For early appendicitis including normal and acutely inflamed appendices, only one dose of antibiotics was used. The postoperative wound sepsis was very low in both groups of patients and there was no statistical difference between them. For late appendicitis including gangrenous and perforated appendices, the antibiotics were continued for 7 days. Eight out of 51 patients who had the topical agent developed wound sepsis compared with one out of 52 patients who received no topical agent. This difference is statistically significant (P = 0.03). All wound infections presented within 2 weeks of operation and were deep. Povidone-iodine, 1 per cent, adversely affects the wound infection rate in late appendicitis and should not be used.

Administration, Topical↗

Conventional vs. triple rubber band ligation for hemorrhoids. A prospective, randomized trial.

Two hundred five patients with symptomatic first- and second-degree hemorrhoids were randomized to receive either conventional rubber band ligation or triple rubber band ligation. In conventional rubber band ligation, the hemorrhoids were ligated at one primary site per session at intervals of four weeks until symptoms were relieved or when all three hemorrhoids were ligated. In triple rubber band ligation, all three primary hemorrhoids were ligated in a single session. After completion of treatment, the patients were examined every three months, or earlier if symptoms recurred. Both methods were effective in the treatment of early hemorrhoids and the incidence of postligation pain and complications was similar. The advantages of having the treatment completed at the initial visit in triple rubber band ligation are obvious. Furthermore, less treatment sessions were required for triple rubber band ligation to control symptoms than for conventional rubber band ligation. Triple rubber band ligation is more cost-effective and therefore is recommended.

Clinical Trials as Topic↗

Ischemic colitis in Kawasaki disease.

A case of Kawasaki disease with colonic involvement is reported. Features suggesting ischemic colitis were seen on radiography and at laparotomy. Nonresective approach coupled with aspirin therapy successfully treated the colonic lesion.

Colitis↗

In vitro and in vivo study of fosfomycin in methicillin-resistant Staphylococcus aureus septicaemia.

Five hundred strains of methicillin-resistant Staphylococcus aureus were tested against various anti-staphylococcal agents. Vancomycin, fusidic acid and fosfomycin were found to be the most effective. Only 1 strain out of 500 was resistant to fosfomycin. Three patients with methicillin-resistant Staphylococcus aureus septicaemia were successfully treated by fosfomycin. We conclude that fosfomycin could be the drug of choice for methicillin-resistant Staphylococcus aureus infection.

Adult↗

Cefoxitin versus gentamicin and metronidazole in prevention of post-appendicectomy sepsis: a randomized, prospective trial.

Three hundred and seven patients with appendicitis were randomized to receive cefoxitin or gentamicin and metronidazole. For early appendicitis, a single preoperative dose of antibiotics was given. For late cases, the antibiotics were continued postoperatively for seven days. Both cefoxitin and gentamicin-metronidazole were effective in the reduction of post-appendicectomy septic complications in early or late appendicitis and there was no statistically significant difference between them. Mild transient and reversible nephrotoxicity was detected in 1.9% of patients who received gentamicin-metronidazole for seven days. Nephrotoxicity was not detected in any other patients. The cost of cefoxitin is higher, but this has to be balanced against the costs of monitoring serum gentamicin and creatinine levels, and the need to adjust the gentamicin dosage in 19% of patients when gentamicin-metronidazole was used. Both cefoxitin and gentamicin-metronidazole are effective and safe when used carefully. Cefoxitin has a slight advantage in its lack of potential nephrotoxicity and ototoxicity.

Adolescent↗

Primary actinomycosis of the abdominal wall.

Two cases of primary actinomycosis of the abdominal wall masquerading as abdominal wall tumours are presented. The interesting clinical presentation and the difficulty in diagnosis are discussed.

Abdominal Muscles↗

The clinical significance of routine histopathologic study of the resected appendix and safety of appendiceal inversion.

A prospective study was done on 1,699 patients operated upon for appendicitis to correlate the operative diagnosis of the surgeon and the histopathologic diagnosis of the pathologist. There are surgeons who only send the appendices for histopathologic study when the operative findings are inconclusive and surgeons who invert rather than resect the appendices on finding a grossly normal appendix at operation. This study was done to find out whether or not these practices of leaving some of the appendix unexamined histopathologically are clinically safe. In this study, surgeons missed abnormal pathologic findings in the appendix in ten of 13 patients and this is irrespective of whether the appendix was normal, acutely inflamed, gangrenous or perforated. The majority of these lesions either require further investigation, treatment or they affected the prognosis of the patient. Nineteen per cent of the patients diagnosed as having normal appendices grossly were found to have acute appendicitis and 7.7 per cent diagnosed as acute appendicitis were normal. Based upon these data, we conclude that the operative diagnosis of the surgeon cannot be relied on to detect abnormal pathologic findings in the appendix. Additional important clinical information can be gained by routine histopathologic study of the resected specimens, and inversion of the appendix is clinically not safe.

Acute Disease↗

Randomized, prospective, and double-blind trial of new beta-lactams in the treatment of appendicitis.

A prospective, randomized, and double-blind study was conducted with 864 patients operated on for appendicitis. In early cases, including normal and acute appendicitis, one dose of antibiotic was given. The rate of postappendectomy septic complications in patients who received cefotaxime, cefoperazone, or moxalactam was very low (about 3%), and there was no statistical difference between the drugs. For late cases, including gangrenous and perforated appendicitis, the antibiotics were continued for 5 days. Moxalactam decreased significantly the septic complications in these patients when compared with the other two drugs. It is safe, free from serious toxic side effects, and more convenient and easier to administer than combination antibiotic therapy. The main disadvantage of moxalactam is its high cost, but this has to be balanced against the savings in nursing time, the cost of monitoring renal function and serum level when aminoglycosides are used, and the reduced usage and manipulation of infusion sets.

Anti-Bacterial Agents↗

The use of transparent semipermeable polyurethane membrane for percutaneous drainage of the biliary tract.

Transparent semipermeable polyurethane membrane was used in maintaining percutaneous biliary tract drains in nine patients. The average length of biliary tract drainage was 59.4 +/- 45.3 days. The membrane was found to be useful and the complications associated with biliary tract drains were reduced. This technique has been well accepted by patients and the medical and nursing staff.

Adhesives↗

Infarction of a duodenal duplication cyst.

An unusual case of infarcted duodenal duplication cyst is presented. Our case is the first ever reported. Total excision followed by duodenojejunostomy successfully cured the patient.

Adolescent↗

Acute appendicitis in the elderly.

A prospective study was done on 104 patients more than 60 years old with appendicitis. The clinical features are by and large, similar to that of the younger patient. However, four patients presented atypically with abdominal distension with little or no pain. A statistically significant increase in appendiceal perforation is found in patients more than 70 years old and in patients with prolonged delay in operation. However, delay on the part of the surgeon contributed only slightly to the high appendiceal perforation as 85.6 per cent of patients who were operated upon within 24 hours of admission. Appendicitis in the elderly patient appeared to progress to perforation faster and perforation occurred in about 40 per cent of patients within 24 hours of onset of symptoms. Five patients died and 29 postoperative complications occurred in 24 more patients. An associated medical disease is linked to a statistically significant increase in mortality. Appendiceal perforation and a total delay of more than 37 hours are associated with a statistically significant increase in morbidity.

Acute Disease↗

Attachment of immunoglobulin to liposomal membrane via protein carbohydrate.

A general method has been developed for the covalent attachment of immunoglobulin molecules to the outer layer of liposomal membranes. Aldehyde groups are generated by the mild oxidation with periodate or galactose oxidase of the carbohydrate groups on the constant region of the heavy chain. The oxidized protein is then reacted with a hydrazide group linked to a membrane component. Detailed studies were carried out with monomers of a monoclonal human IgM and two monoclonal murine IgM antibodies specific for the 1-dimethylaminonaphthalene-5-sulfonyl (Dns) group. Two hydrazide-containing hydrophobic reagents were used: N alpha-lauroyl, N epsilon-Dns-lysine hydrazide and lauric acid hydrazide. The number of protein aldehyde groups formed was assayed by reaction with N-(2,4-dinitrophenyl)-beta-alanylglycylglycine hydrazide. Measurement of the intrinsic affinity for Dns-lysine of the processed anti-Dns IgMs demonstrated no substantial impairment of the specific reactivity of the antibody either from the oxidation step or the subsequent attachment to small unilamellar vesicles. The extent of attachment of antibody to small unilamellar vesicles was evaluated with respect to the mol% of hydrazide in the membrane, the duration of the incubation period for the aldehyde-hydrazide reaction and the ratio of protein to hydrazide. The yield of attached protein was significantly dependent on each of these experimental parameters over the ranges tested. Under the most favorable conditions the extent of covalent attachment of IgMs to small unilamellar vesicles was 535 micrograms of protein per mumol of phospholipid, corresponding to 0.3 mol% of protein. Under these conditions, 61% of the total protein was associated with the small unilamellar vesicle fraction after fractionation by gel filtration. The attachment of the antibody to small unilamellar vesicles did not destroy the integrity of the vesicles, as demonstrated by the retention of carboxyfluorescein following initial encapsulation during the formation of small unilamellar vesicles.

Aldehydes↗

Negative findings at appendectomy.

A prospective study was conducted on 107 patients with negative findings at appendectomy. The operation was unnecessary in 94 of the patients. A cause for the symptoms could be found in 43 patients, 32 during operation and 11 later by investigation or by a second operation. Diagnosis remained unclear in 64 patients. There are many diseases that mimic acute appendicitis, and based on the disease entities encountered in this series, the surgeon must examine the abdominal organs carefully if the appendix is normal. The financial loss of negative appendectomy was substantial in our study, and the total early and late complication rate was 14 percent. Patients with negative appendectomy should be regularly followed up to 1 year, since 9.3 percent of patients had a diagnosis made later by investigation, and 12.1 percent had moderate to severe pain on follow-up. Possible means to cut down the negative appendectomy rate without increasing the perforation rate have been suggested herein for further evaluation.

Abdomen, Acute↗

Restriction in IgM expression--VI. Affinity analysis of monoclonal anti-dansyl antibodies.

Affinity restriction in the IgM response to the 5-dimethylaminonaphthalene-1-sulfonyl (dansyl) group was studied with 56 monoclonal IgG and IgM affinity-purified antibodies. These were generated by immunization with dansyl-Ficoll or dansyl-B gamma G. Association constants for N epsilon-dansyl-lysine were determined by fluorescence titration based on resonance energy transfer. The antibodies were also characterized with respect to the emission maximum of the antibody-ligand complex. The distribution of binding constants covered a 100,000-fold range, demonstrating thereby a restriction in IgM affinity relative to IgG affinity. In the secondary response the IgG affinity exhibited a ceiling of about 1 X 10(10) M-1, a value in accord with the size and hydrophobic nature of the dansyl group. In the case of IgM, with one exception, the value of 1 X 10(7) M-1 was not exceeded with IgM antibodies isolated from 28 hybridomas. This system, therefore, provides further evidence for the restriction in expression of IgM as a general feature of the immune response.

Animals↗