Biomedical subjects

S M Johnston

Publications and source records attributed to S M Johnston.

14 recordsLinked to original sources

PubMed2003

Changing trends in the management of gallstone disease.

BACKGROUND: Day case cholecystectomy is increasingly becoming a management option for elective cases while "same admission" cholecystectomy is now considered a favorable option in the treatment of acute cholecystitis. To assess the advent of these changes in our surgical practice, a retrospective analysis of our experience is presented. METHODS: All patients undergoing cholecystectomy between January 2000 and January 2001 were analyzed according to admission status, operation type, conversion rate, complications, and nonsurgical intervention. RESULTS: 156 patients underwent cholecystectomy and 152 charts were retrieved. Laparoscopic cholecystectomy was performed on 95% of patients with a conversion rate of 9%. Morbidity for the series was 12.5%, including one common bile duct injury (0.6%). Day case and acute cholecystectomy comprised 67% of our cholecystectomy practice. CONCLUSIONS: Our findings suggest that there is an increasing trend toward shortening the hospital stay of patients undergoing laparoscopic cholecystectomy. This does not appear to have had a deleterious effect on outcome.

Adult↗

PubMed2003

Surgical informatics on the Internet: any improvement?

PURPOSE: The Internet is a popular, but ungoverned, source of medical information. This study tracked the change in performance of commonly available search engines and the quality of medical data therein over a four-year period. METHODS: We compared the accuracy of information on a commonly performed surgical procedure (vasectomy) using six standard search engines in a four-year period and with two recently developed search engines. The top 25 ranked sites cited by each search engine were scored for description of the procedure, post-operative instructions, complications and unproven associations. RESULTS: There was no improvement in quality of individual sites over the study period. Additionally, the hit rate of search engines remained poor with 27 sites cited (40%) in 2002 either irrelevant or unavailable. DISCUSSION: Few useful sites with accurate information on surgical procedures are available on the Internet and simple search strategies fail to identify site quality or relevancy. CONCLUSION: At present, the Internet cannot be recommended as a reliable resource for many aspects of health information for patients. The onus is on health-care providers to provide high quality sites and direct patients to these sources of reliable information

Humans↗

PubMed1997

Iron deficiency enhances cholesterol gallstone formation.

BACKGROUND: Cholesterol gallstones occur most commonly in multiparous women, but the causes for this phenomenon remain unclear. This same patient population is prone to chronic iron deficiency anemia. In addition, iron is known to play an important role in hepatic enzyme metabolism. Therefore, we tested the hypotheses that iron deficiency would alter hepatic cholesterol metabolism and enhance gallstone formation. METHODS: Forty adult prairie dogs were fed either a control iron-supplemented (200 ppm), an iron-deficient (8 ppm), a 0.4% cholesterol iron-supplemented (200 ppm), or a 0.4% cholesterol iron-deficient (8 ppm) diet. After 8 weeks gallbladder bile, serum, and liver were harvested. Gallbladder bile was examined for cholesterol crystals and gallstones. Bile lipids and hepatic enzymes were measured, and a cholesterol saturation index (CSI) was calculated. RESULTS: Animals receiving the iron-deficient diet were more likely to have cholesterol crystals in their bile than were animals on the control diet (80% vs. 20%; p < 0.05). Animals on the 0.4% cholesterol iron-deficient diet had more cholesterol crystals per high-powered field (79 +/- 10 vs. 49 +/- 9; p = 0.07), a higher molar % cholesterol (6.0 +/- 0.3 vs 4.4 +/- 0.5; p < 0.05), and a higher CSI (1.27 +/- 0.10 vs. 0.91 +/- 0.07; p < 0.05) compared to animals receiving the 0.4% cholesterol iron supplemented diet. The 7 alpha-hydroxylase levels were lower in the animals on the iron-deficient diet compared to those receiving the control diet (0.42 +/- 0.08 vs 1.17 +/- 0.40 pmol/mg per minute; p = 0.07). CONCLUSIONS: These data suggest that an iron-deficient diet (1) alters hepatic enzyme metabolism, which, in turn, (2) increases gallbladder bile cholesterol and promotes cholesterol crystal formation. We conclude that iron deficiency plays a previously unrecognized role in the pathogenesis of cholesterol gallstone formation in women.

Animals↗

PubMed1993

Comparison of pentobarbital alone and pentobarbital in combination with lidocaine for euthanasia of dogs.

Pentobarbital alone, pentobarbital plus 1% lidocaine solution, pentobarbital plus 2% lidocaine solution, and pentobarbital plus 3% lidocaine solution were each used to euthanatize 6 dogs. For each dog, time between the beginning of injection of the euthanasia solution and each of the following events was recorded: collapse, onset of apnea, flat-line electrocardiogram, flat-line electroencephalogram, loss of palpable heartbeat, and loss of palpable pulse. Any signs of pain or discomfort were also recorded. There were no significant differences among groups except for time to flat-line electrocardiogram. Dogs euthanatized with pentobarbital alone had significantly longer times than did dogs euthanatized with pentobarbital in combination with any of the lidocaine concentrations. We concluded that pentobarbital in combination with lidocaine was a reasonable alternative to pentobarbital alone when euthanatizing dogs.

Animals↗

PubMed1986

The microbiological contamination of equipment processed by the HSDU.

The microbiological hazard to staff of used instruments and equipment when returned to the HSDU appears to be small providing reasonable precautions are taken (Parsons et al, 1985). Nevertheless, little evidence is available on the contamination of used equipment or the efficiency of cleaning and disinfection methods.

Central Supply, Hospital↗

PubMed1985

An outbreak of food-borne enterotoxigenic Escherichia coli diarrhoea in England.

An outbreak of diarrhoea with abdominal pain occurred among members of the staff of a school and their guests after a social function at which a cold buffet was served. Sixty people attended the function and 43 subsequently completed questionnaires. Of these, 27 had diarrhoea. The median incubation period was 36 h and the range 12-66 h. Food history analysis showed an association between diarrhoea and eating curried turkey mayonnaise. Stool specimens from 13 of those who developed diarrhoea were examined: Escherichia coli 06.H16 (producing heat-stable and heat-labile enterotoxins) was found in nine specimens and E. coli 027.H20 (producing heat-stable enterotoxin) in 11 specimens. Eight patients had both strains and only one was negative for enterotoxigenic E. coli. Food samples were not available for examination. Enterotoxigenic E. coli should be considered as a possible cause in well-defined outbreaks of food-borne diarrhoea with abdominal pain.

Abdomen↗

PubMed1984

Effects of long-term lithium administration on renal structure and function in rats. A distinctive tubular lesion.

Because lithium salts are widely used for long-term therapy of affective disorders and have been recently implicated as a cause of tubulointerstitial renal disease, we have undertaken experiments designed to establish the site of the early and late pathologic lesions and to determine their correlation with the lithium-induced concentrating defect. Male Wistar rats given a semisynthetic diet that contained lithium carbonate, 90 mEq/kg dry weight, developed serum lithium levels in the human therapeutic range; pair-fed controls received sodium carbonate. Within 3 weeks, treated rats developed marked polyuria, with elevation of free water clearance and vasopressin-resistant diabetes insipidus. Early morphologic changes were confined to the cortical collecting tubules and, possibly, contiguous portions of distal tubules. The tubules were dilated and irregularly lined with cells that had bulging or thinned basophilic cytoplasm, enlarged nuclei, sometimes basal vacuolization, and a few mitoses. These changes were evident at 3 weeks and progressed through the end of the observation period at 18 weeks. The proliferative component of the lesion was demonstrated by the finding of a significant and specific increase in 3H-thymidine uptake by nuclei of collecting/distal tubules of lithium-treated rats. The lesion, but not the increased thymidine uptake, extended into the medullary collecting ducts at 9 and 18 weeks. Although occasional intratubular mononuclear cells were seen at 9 and 18 weeks, no interstitial inflammation or fibrosis was seen. These tubular epithelial lesions were not seen in the kidneys of Brattleboro rats or glucose-treated Wistar rats despite comparable polyuria. We suggest that this early, persistent, and reproducible lesion, characterized by reactive and proliferating tubular cells in the cortical collecting tubules, predisposes the kidney to injury from otherwise mild or insignificant insults and may explain the sporadic occurrence of serious tubulointerstitial disease in patients on long-term lithium therapy.

Animals↗

PubMed1977