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Biomedical subjects

G M Lawson

Publications and source records attributed to G M Lawson.

At least 37 records · Page 2Linked to original sources
PubMed1995

Sports fractures of the distal radius--epidemiology and outcome.

Of 2774 consecutive, prospectively documented fractures of the distal radius, 225 (8 per cent) occurred as sports injuries, mainly in young men. Soccer produced the greatest number of wrist fractures with 112 cases (50 per cent). Skiing, dancing and rugby caused 12 per cent, 9 per cent and 7 per cent of all sporting wrist fractures respectively. Skiing, horseriding and dancing consistently resulted in more complex fractures. In soccer, synthetic pitches increased the likelihood of a fracture following a fall by a factor of five. Twelve per cent of fractures required further treatment because of instability leading to redisplacement. The complication rate was 14 per cent with the majority being cases of malunion (12 per cent). Of the 131 patients who returned a questionnaire, 72.5 per cent had returned to their original sport. This was influenced mainly by the patient's age and pre-injury standard of competition.

Adolescent↗
PubMed1995

A comparison of immediate and delayed nerve repair using autologous freeze-thawed muscle grafts in a large animal model. The simple injury.

Freeze-thawed muscle grafts (FTMG) have been suggested as an alternative to nerve grafts in reconstruction of peripheral nerve defects. This study compares the results of immediate and delayed nerve repair with freeze-thawed muscle graft in a large animal model. Under general anaesthesia, ten adult sheep underwent excision of 3 cm of the right median nerve. Five had immediate nerve reconstruction with FTMGs (Group A) and five were repaired after 4 weeks (Group B). At 6 months, both the right (repaired) and left ("control") median nerves of each sheep were assessed. Nerve blood flow distal to the graft in both groups of repaired nerves was approximately 60% of that in their respective control nerves. Peak nerve conduction velocities were significantly slower in the repaired nerves. The mean fibre diameters of the immediate and delayed repairs were 5.06 and 3.90 mu respectively compared to a control mean of 8.58 mu. G-ratios confirmed that the repaired nerves in both groups were well myelinated. The authors conclude that the FTMG can be used in delayed as well as immediate nerve reconstruction with minimal impairment of final results.

Animals↗
PubMed1995

Angioleiomyomas of the hand. A report of 14 cases.

We have reviewed a series of 14 angioleiomyomas of the hand. Unlike angioleiomyomas elsewhere, those occurring on the hand are less commonly painful, have an equal sex distribution and are not predominantly of the solid type as seen in the lower limb. We were unable to find a strong association between histological appearance and clinical presentation. We were able to demonstrate nerve fibres within angioleiomyomas, which have not been reported previously.

Adolescent↗
PubMed1995

Early cellular rejection after orthotopic liver transplantation correlates with low concentrations of FK506 in hepatic tissue.

We have previously reported that low hepatic tissue cyclosporine levels correlate with early cellular rejection after liver transplantation. The aim of this study is to determine whether there is a similar relationship in patients treated with FK506. Twenty-five liver biopsies were performed in 10 patients immunosuppressed with FK506 without cellular rejection: day 7 = 10; day 14 = 3; day 21 = 9; day 28 = 1; day 35 = 1; and day 42 = 1. These 10 patients without cellular rejection were compared with 7 patients immunosuppressed with FK506 with cellular rejection who underwent a total of 23 liver biopsies, including 9 biopsies that showed rejection: day 7 = 4; day 14 = 2; day 21 = 1; day 28 = 1; and day 49 = 1. There was no significant difference between the nonrejection and current rejection groups in the median plasma concentration of FK506, 0.9 ng/mL versus 0.9 ng/mL (P = .50). In contrast, the median hepatic tissue concentration of FK506 was significantly higher in the nonrejection group than it was in the current rejection group, 144 ng/g versus 48 ng/g (P = .02). In the current rejection group, 7 of 9 hepatic tissue concentrations of FK506 were < 100 ng/g, and in the nonrejection group, 18 of 25 hepatic tissue concentrations were > 100 ng/g. Low hepatic tissue concentrations of FK506 correlate with the occurrence of early cellular rejection after liver transplantation, in contrast to plasma concentrations of FK506. A hepatic tissue concentration of FK506 < 100 ng/g is 78% sensitive and 72% specific for cellular rejection.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1995

A prospective audit of knee arthroscopy: a study of the accuracy of clinical diagnosis and therapeutic value of 325 knee arthroscopies.

A prospective audit of 321 patients (325 knees) placed on the waiting list for arthroscopy revealed an accuracy of the preoperative diagnosis of 57%. The accuracy of consultants was 71% and the other grades of staff was 49%. The operation treated a pathological lesion and was considered to be therapeutic in 154 knees (47%); an operation was more likely to be therapeutic when the preoperative diagnosis was correct (132 knees) than when the diagnosis was incorrect (22 knees). Attention to establishing an accurate preoperative diagnosis and close supervision of the waiting lists by consultants will reduce the number of non-therapeutic arthroscopies.

Adult↗
PubMed1994

A placebo-controlled trial of cyclosporine enemas for mildly to moderately active left-sided ulcerative colitis.

BACKGROUND/AIMS: Uncontrolled studies suggest that cyclosporine administered as an enema may be of benefit for left-sided ulcerative colitis and safer than intravenous or oral administration. The efficacy and safety of cyclosporine enemas for left-sided ulcerative colitis in a placebo-controlled trial was assessed. METHODS: Steroid and mesalamine enemas were withdrawn before the study. Forty patients were assigned to 1 of 4 strata: no concomitant therapy, oral steroids, oral salicylates, or oral steroids and salicylates. After stratification, patients were randomized to nightly treatment with 350 mg cyclosporine (n = 20) or placebo (n = 20) enemas. Clinical response was determined at baseline and 4 weeks by endoscopy, physician assessment, and a patient diary of daily symptoms. Trough blood cyclosporine levels were measured by high-performance liquid chromatography. RESULTS: At 4 weeks, 8 of 20 patients (40%) who received cyclosporine showed clinical improvement compared with 9 of 20 patients (45%) who received placebo. One patient receiving cyclosporine had reversible neutropenia attributable to sulfasalazine, and another patient receiving cyclosporine was unable to tolerate the enema vehicle. No other toxicity was noted during the trial. Blood cyclosporine levels were detectable in only two patients. CONCLUSIONS: Cyclosporine enemas administered in a dosage of 350 mg/day for 4 weeks are not efficacious in mildly to moderately active left-sided ulcerative colitis.

Administration, Oral↗
PubMed1994

The histopathology of fibrous flexor sheath ganglia.

In order to determine if fibrous flexor sheath ganglia had any histological features that could distinguish them from other ganglia, wer reviewed 50 consecutive ganglia treated by surgical excision. Of these, eight were fibrous flexor sheath ganglia. They did not have any specific features to distinguish them from the other ganglia. Furthermore, an absence of true synovial lining in them refutes the theory that they may result from synovial herniation around the A1 pulley.

Adolescent↗
PubMed1994

Automated HPLC assay of fluoxetine and norfluoxetine in serum.

This automated assay determines the concentration of the antidepressant fluoxetine (Prozac) and its active metabolite norfluoxetine in serum by reversed-phase HPLC with spectrophotometric detection. Extraction, injection, and quantification are performed by the Gilson Aspec automated sample handler. The patient's specimen, with added protriptyline as internal standard, is extracted with solid-phase and liquid-liquid methods. Separation is conducted isocratically on a 5-microns (particle size) Supelcosil LC-8-DB reversed-phase column with a triethylamine acetate:acetonitrile mobile phase. The detection limit is 10 micrograms/L and absorbance varies linearly with concentration between 20 and 1,000 micrograms/L for both compounds. Mean recovery was 62% for fluoxetine and 70% for norfluoxetine over linear limits. Within-run and day-to-day imprecision (CV), evaluated at three concentrations (50, 200, and 500 micrograms/L), ranged from 2% to 7%. An extensive interference study of 108 drugs was conducted. Results (n = 58) by the automated method (y) correlated well with those by a manual HPLC method (x): y = 0.96x + 10.20 (r = 0.951, Sylx = 42.9) for fluoxetine, and y = 0.95x - 1.37 (r = 0.917, Sylx = 47.2) for norfluoxetine.

Autoanalysis↗
PubMed1993

Serum nicotine and cotinine levels during nicotine-patch therapy.

We related serum nicotine and cotinine levels while subjects were smoking their usual numbers of cigarettes to levels while wearing a nicotine patch under carefully controlled, smoke-free conditions in a clinical research center. Twenty-four volunteers who needed intensive treatment for severe nicotine dependence were admitted to the clinical research center and were treated with a 22 mg transdermal nicotine patch each day and an intensive smoking-cessation program. Serum nicotine and cotinine levels, withdrawal symptoms, and hours and quality of sleep were noted. The steady-state serum nicotine and cotinine levels produced with the nicotine patch were lower than those observed when the subjects were smoking. Mean nicotine and cotinine levels were inversely related to mean withdrawal scores for the first 6 days. A fixed dose of transdermal nicotine will not be effective for all smokers. Individualization of therapy should be based on objective biologic measures such as serum cotinine and subjective assessment of withdrawal relief.

Administration, Cutaneous↗
PubMed1993

Substance abuse testing of urine by GC/MS in scanning mode evaluated by proficiency studies, TLC/GC, and EMIT.

Using GC/MS in scanning mode as a screening and definitive identification methodology for substance abuse testing, 4500 urine samples have been analyzed. The accuracy and sensitivity of this method was evaluated by the results of 92 proficiency sample analyses, reanalyses by TLC screening with GC confirmation of 125 samples from forensic sources and reanalysis by EMIT screening for seven groups of drugs confirmed by GC/MS of 590 samples from industrial and treatment sources. The results of these studies are presented.

Amphetamine↗
PubMed1993

Cyclosporine enemas for treatment-resistant, mildly to moderately active, left-sided ulcerative colitis.

Ten patients with treatment-resistant left-sided ulcerative colitis were treated in an open protocol with 350 mg cyclosporine enemas nightly for 4 wk. A 12-point clinical disease activity index (DAI) score was calculated at baseline and after 4 wk. Whole blood and colonic tissue cyclosporine concentrations were determined by HPLC at the end of the study. Five of 10 patients responded to treatment, defined as a decrease in the clinical DAI score > or = 3 points. Responders retained the enemas longer than nonresponders (7.5 +/- 1.3 vs. 3.3 +/- 2.2 h, p = 0.01), and there was a positive correlation between decrease in the clinical DAI score and enema retention time (r = 0.64, p = 0.05). The mean colonic tissue cyclosporine concentration was not significantly higher in responders than in nonresponders (2884 +/- 1635 vs. 2359 +/- 576 ng/g, p = 0.52), and the correlation between decrease in the clinical DAI score index and colonic tissue cyclosporine was weak (r = 0.39, p = 0.26). Cyclosporine was undetectable in whole blood samples from all patients, and there were no apparent side effects with treatment. In conclusion, 50% of patients with treatment-resistant left-sided ulcerative colitis significantly improved during therapy with cyclosporine enemas for 4 wk. Patients with longer enema retention times were more likely to respond. A controlled trial is underway to investigate these findings further.

Administration, Topical↗
PubMed1992

Hepatic allograft cyclosporine concentration is independent of the route of cyclosporine administration and correlates with the occurrence of early cellular rejection.

This study compares the hepatic-tissue cyclosporine concentrations in liver biopsy specimens from patients with and without cellular rejection after orthotopic liver transplantation. Nine patients without cellular rejection were studied, including five patients receiving intravenous cyclosporine who had biopsies on posttransplant day 7 and four patients receiving oral cyclosporine who had biopsies on day 21. In these patients no significant differences were seen in blood cyclosporine concentrations (mean +/- S.D.) (310 +/- 162 vs. 273 +/- 310 ng/ml) and hepatic-tissue cyclosporine concentrations (3,451 +/- 1,262 vs. 3,545 +/- 456 ng/gm). These nine patients without cellular rejection were then compared with eight patients with cellular rejection who were receiving intravenous cyclosporine, including seven patients who had biopsies on post-transplant day 7 and one patient who had a biopsy on day 14. In patients with and without cellular rejection blood cyclosporine concentrations were 330 +/- 64 vs. 294 +/- 146 ng/ml, and hepatic-tissue cyclosporine concentrations were 1,879 +/- 998 vs. 3,493 +/- 936 ng/gm, p less than 0.01. We conclude that hepatic-tissue cyclosporine concentrations are independent of the route of cyclosporine administration and that low hepatic-tissue cyclosporine concentrations correlate with early cellular rejection after orthotopic liver transplantation.

Administration, Oral↗
PubMed1992

Measurement of colonic tissue cyclosporine concentration in children with severe ulcerative colitis.

Recent studies suggest that cyclosporine may be an alternative to colectomy in children with severe ulcerative colitis who fail traditional therapy with bowel rest and high-dose corticosteroids. We report the clinical course of two such children. Patient 1 received oral cyclosporine at 15 mg/kg/day for 1 week followed by 8 mg/kg/day for 6 weeks. Clinical remission occurred within 5 days and has been sustained for 24 weeks after azathioprine was substituted for cyclosporine. Patient 2 received oral cyclosporine at 7-8 mg/kg/day for 7 days after which colectomy was performed due to lack of clinical improvement. Blood cyclosporine levels for patient 1 ranged from 95 to 406 ng/ml and for patient 2 from 36 to 65 ng/ml. Sigmoid colonic tissue cyclosporine concentrations for patients 1 and 2 were 10,058 and 3,205 ng/g, respectively. The patient who responded had significantly higher blood and colonic tissue cyclosporine concentrations than the patient who did not respond. Further studies with larger numbers of patients are needed to determine if there is a correlation between blood and colonic tissue cyclosporine concentrations and clinical response.

Administration, Oral↗
PubMed1990

The role of the paediatric surgeon in alleged child sexual abuse.

Two hundred ninety cases of alleged child sexual abuse (CSA) were reported in Edinburgh and the Lothian region over the 7-year period from 1982 through 1988. We have found an increase in the incidence of alleged CSA, which has resulted in greater involvement of the paediatric surgeon. CSA was found to be occurring with increasing frequency in younger children. The physical examination and the role of general anaesthesia are discussed together with the data about the collection of forensic material.

Adolescent↗