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Biomedical subjects

A J Sim

Publications and source records attributed to A J Sim.

At least 19 recordsLinked to original sources
PubMed2002

Isotonic biaxial loading of fibroblast-populated collagen gels: a versatile, low-cost system for the study of mechanobiology.

We developed a simple, versatile system for applying a range of biaxial loads to cell-matrix constructs for the study of mechanobiology. The system consists of porous polyethylene bars that are polymerized into a square fibroblast-populated gel and loaded by freely hanging weights attached to sutures routed through a custom loading rig. The cost to manufacture each mold/loading rig pair was less than US dollars 250 and the expected life of the components is up to 10 years. Neonatal and adult cardiac fibroblasts contracted gels to a decreasing extent as external load was increased ( P=0.003) and achieved contraction forces of up to 1.4 mN per million cells. Strain distributions were reasonably homogeneous in the central region of the gel (25% of gel area), but clearly nonhomogeneous outside that central region. The primary advantages of this system are simplicity, low cost, biaxial loading, and the ability to test for a dose-response effect of mechanical load. The current disadvantages are the inability to apply cycling loading and the inhomogeneities introduced by the use of rigid loading bars.

Animals↗
PubMed1999

Treatment of pilonidal sinus by primary closure with a transposed rhomboid flap compared with deep suturing: a prospective randomised clinical trial.

OBJECTIVE: To assess two techniques of primary closure after excision of pilonidal sinus. DESIGN: Prospective randomised study. SETTING: University department of surgery, United Arab Emirates. SUBJECTS: 46 patients with chronic pilonidal sinus disease, 24 treated by rhomboid flap transposition, and 22 by deep suturing technique. MAIN OUTCOME: Early mobility and recurrence. RESULTS: All patients in the rhomboid flap transposition group healed their wounds primarily compared with 17 in the primary deep suturing group (77%). (P = 0.02). Five patients wounds broke down as a result of haematoma and infection (23%). The mean hospital stay for the rhomboid flap technique was 6 days compared with 9 days after deep suturing, and the mean follow up for both groups was 18 months, the rhomboid flap group returned to work a mean of nine days earlier than the deep suturing group (23 days). No recurrence has been identified yet in the rhomboid flap group, while 2 recurrences have developed in the deep suturing group (9%). CONCLUSION: Primary closure after excision of pilonidal sinus with a transposed rhomboid flap is successful in the management of pilonidal sinus and is superior to primary closure by deep suturing.

Adolescent↗
PubMed1995

Helicobacter pylori infection in perforated peptic ulcer disease.

This study examined a possible aetiological agent, namely, Helicobacter pylori, in perforated peptic ulcer disease and its relationship to persisting ulcer. Twenty-nine patients with perforated peptic ulcer underwent simple closure of the perforation at laparotomy. A 13C urea breath test carried out on the eighth day after operation was positive in 24 patients. Fourteen of 17 patients who underwent upper gastrointestinal endoscopy 6 weeks after discharge from hospital had a positive 13C urea breath test. The biopsy urease test performed on mucosal samples taken at endoscopy was positive in 12 of these 14 patients, indicating continuing active infection with H. pylori. Seven patients with positive 13C urea breath and biopsy urease tests had persisting duodenal ulceration. None of the three patients with a negative 13C urea breath test had evidence of duodenal ulceration at endoscopy. The association between a high rate of duodenal ulcer persistence and a high incidence of H. pylori infection suggests that antibiotic therapy to eradicate this microorganism should be given to all patients with perforated peptic ulcer disease.

Adult↗
PubMed1995

Early patient discharge following appendicectomy: safety and feasibility.

One hundred and twenty patients with non-perforated acute appendicitis were discharged within 72 h of operation; 50 left hospital within 48 h of surgery. Criteria adopted for early discharge were: stable vital signs, active bowel sounds, ambulation and ability to tolerate fluid and food without discomfort. The patient's contact address was taken and every patient was requested to report to the out-patient department on the 7th post-operative day to remove stitches and assess the wound. There were three re-admissions. Five patients, however developed wound problems, three had wound infections, one had an indurated painful wound and the last developed erythema; the latter two patients were treated on an out-patient basis. Twenty patients were not happy about early discharge. Early discharge following appendicectomy is safe and can be practiced in uncomplicated cases of acute appendicitis.

Adolescent↗
PubMed1994

A randomized prospective study of cefoxitin versus piperacillin in appendicectomy.

A randomized prospective study of antibiotic prophylaxis using a single dose of either cefoxitin or piperacillin is presented. The trial was carried out in Al Ain Hospital in the period 1989-1992 on 250 adult patients with non-perforated appendicitis. One group (124 patients) received 2 g cefoxitin, the other group (126 patients) 2 g piperacillin. Antibiotics were administered intravenously in the operating theatre immediately before surgery. Wound infection occurred in three patients, 2.4% of the cefoxitin group and in five patients (4%) of the second group (with no significant difference). The commonest infecting organisms were Escherichia coli (5 out of 8). Mean hospital stay for patients with wound infection was 15 days (range 12-21) compared with 6 days, (range 4-8) for non-infected cases. Prophylactic cefoxitin or piperacillin were each therefore similarly effective in minimizing the rate of wound infections in patients with non-perforated appendicitis.

Acute Disease↗
PubMed1994

Simple surgical audit: an aid to undergraduate curriculum development.

This study investigates the usefulness of a simple surgical audit in designing the undergraduate surgical curriculum in the newly established medical school of the United Arab Emirates. The audit system was designed for use by people previously unaccustomed to this activity. The pattern of disease is found to be biased towards a young male expatriate population. It has been possible to predict the likelihood of a particular disease being available for teaching purposes and has drawn attention to the relative absence of some conditions which are commonly found elsewhere. Allowances need to be made for this and teaching strategies other than those which require direct patient contact should be considered. This method of curriculum design may find use in other places where health care patterns are changing.

Curriculum↗
PubMed1992

Clinicopathological assessment of gastric biopsy samples of patients with Helicobacter pylori infection--metronidazole resistance and compliance problems in the United Arab Emirates.

The significance of Helicobacter pylori (HP) infection was assessed prospectively in forty-two patients with dyspepsia using histological, bacteriological and biopsy urease techniques. Thirty-eight patients (90.5%) were positive for HP infection and were treated with bismuth subcitrate (De Nol), tinidazole and doxycycline. HP was present in the antrum, corpus, fundus, duodenum and gastric juice in 36, 26, 23, 2 and 2 patients respectively (p < 0.01, X2 test). Histological assessment yielded more positive identifications of HP than the urease test (36 vs 28 positive cases, p < 0.01, McNemar's X2 test), while histology and bacteriology were virtually identical (38 vs 37 of 41 pairs, p > 0.5, X2 test). There was a good correlation between bacterial and polymorphonuclear leucocyte (PMNL) counts per high power field (r = 0.8; p < 0.001; n = 34 pairs). There was resistance to metronidazole in 10 out of 16 isolates, but no resistance was recorded against tetracycline (p < 0.001, X2 test). Among the sixteen patients who attended follow-up endoscopy, there was clinical improvement and no evidence of HP in 5 individuals (31.25%). One patient had amelioration of his symptoms, 5 experienced no change and in 5 their symptoms became worse. Metronidazole resistance may be one of the important factors in the United Arab Emirates and elsewhere.

Adolescent↗
PubMed1991

Towards safer surgery.

There is a need for wider adoption of safer surgical techniques to reduce the chances of human immunodeficiency virus (HIV) transmission in the operating theatre. When a patient is known to have HIV infection extra precautions, including the wearing of additional protective clothing, should be carried out, even though it is not known whether such special measures are of value.

Asepsis↗
PubMed1988

Postoperative positive nitrogen balance with intravenous hyponutrition and growth hormone.

11 patients having major gastrointestinal surgery were allocated at random to receive either biosynthetic human growth hormone (BSHGH) 0.1 mg/kg or placebo daily for the first 7 postoperative days. All patients received the same intravenous feeding regimen, which contained 2.09 MJ glucose, 1.88 MJ fat, and 7 g N daily. Patients receiving BSHGH were in positive nitrogen balance throughout the study (mean 1.8 [SEM 0.4] g N/day) and those receiving placebo were in negative nitrogen balance (mean -0.9 [0.7] g N/day). Resting energy expenditure progressively increased in the patients receiving BSHGH (115.7% [14.8] on day 7) but remained unchanged in patients receiving placebo (99.35% [1.4]). Fat oxidation was nearly three times higher in the patients on BSHGH (4.09 [0.38] MJ/day) than in controls (1.38 [0.50]). Carbohydrate oxidation remained about the same in both groups. Whole-body protein turnover, synthesis, and breakdown were increased in the patients receiving growth hormone.

Aged↗
PubMed1988

Surgeons and HIV.

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Acquired Immunodeficiency Syndrome↗