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Biomedical subjects

R L Aspinall

Publications and source records attributed to R L Aspinall.

16 recordsLinked to original sources
PubMed2001

A prospective randomized controlled study of the efficacy of ketamine for postoperative pain relief in children after adenotonsillectomy.

BACKGROUND: Adenotonsillectomy is commonly needed by children with obstructive sleep apnoea syndrome. This population is at high risk of life threatening airway obstruction in the postoperative period. METHODS: Fifty children were studied to test the efficacy of an alternative analgesic to the use of opioids in providing analgesia in the immediate postoperative period. Patients were randomized to receive either 0.1 mg.kg-1 morphine or 0.5 mg.kg-1 ketamine at induction. RESULTS: Ketamine was as effective as morphine with no additional side-effects. CONCLUSIONS: Ketamine is a safe and effective alternative to morphine to provide analgesia in the immediate postoperative period after tonsillectomy.

Adenoidectomy↗
PubMed1995

Denial of effective treatment and poor quality of clinical information in placebo controlled trials of ondansetron for postoperative nausea and vomiting: a review of published trials.

OBJECTIVE: To determine how many patients were deprived of treatment by being given placebo as comparator in trials of ondansetron for postoperative nausea and vomiting. DESIGN: Review of published trials of ondansetron during 1991 to July 1994. SETTING: Medline search in a university department of anaesthesia. SUBJECTS: 8806 patients who had been included in 18 indexed placebo controlled trials of ondansetron as prophylaxis against or treatment of postoperative nausea and vomiting. RESULTS: Five studies (1236 patients) had been published by July 1992. All were placebo controlled trials. By July 1994, 8806 patients had been included in 18 indexed placebo controlled studies of prophylaxis or treatment. Only 462 patients had been in studies that compared ondansetron with other drugs, and there were no indexed comparative trials of treatment of nausea and vomiting. Roughly 2180 patients had been given placebo as prophylaxis and 440 had been given placebo when already experiencing postoperative nausea or vomiting. CONCLUSIONS: Around 2620 patients in the reviewed studies were denied existing drugs, which, though not completely effective or without side effects, do bring some relief from postoperative nausea and vomiting. Drug regulatory bodies should collaborate with drug companies to ensure better comparison of new with established drugs. This would avoid placebos being given to more than the fewest patients necessary to confirm effect and would allow doctors to be informed more quickly about relative efficacies.

Anesthesia Department, Hospital↗
PubMed1994

The safety and efficacy of combination N-butyl-deoxynojirimycin (SC-48334) and zidovudine in patients with HIV-1 infection and 200-500 CD4 cells/mm3.

We conducted a double-blind, randomized phase II study to evaluate the safety and activity of combination therapy with N-butyl-deoxynojirimycin (SC-48334) (an alpha-glucosidase I inhibitor) and zidovudine versus zidovudine alone. Patients with 200 to 500 CD4 cells/mm3 who tolerated < or = 12 weeks of prior zidovudine therapy received SC-48334 (1000 mg every 8 h) and zidovudine (100 mg every 8 h) or zidovudine and placebo. Sixty patients received combination therapy and 58, zidovudine and placebo. Twenty-three patients (38%) and 15 (26%), in the combination and zidovudine groups, respectively, discontinued therapy (p = 0.15). The mean SC-48334 steady-state trough level (4.04 +/- 0.99 micrograms/ml) was below the in vitro inhibitory concentration for human immunodeficiency virus (HIV). The mean increase in CD4 cells at week 4 was 73.8 cells/mm3 and 52.4 cells/mm3 for the combination and zidovudine groups, respectively (p > 0.36). For patients with prior zidovudine therapy, the mean change in CD4 cells in the combination and zidovudine groups was 63.7 cells/mm3 and 4.9 cells/mm3 at week 8 and 6.8 cells/mm3 and -45.1 cells/mm3 at week 16, respectively. The number of patients with suppression of HIV p24 antigenemia in the combination and zidovudine groups was six (40%) and two (11%) at week 4 (p = 0.10) and five (45%) and two (14%) at week 24 (p = 0.08), respectively. Diarrhea, flatulence, abdominal pain, and weight loss were common for combination recipients.(ABSTRACT TRUNCATED AT 250 WORDS)

1-Deoxynojirimycin↗
PubMed1988

Double-blind, placebo-controlled endoscopic comparison of the mucosal protective effects of misoprostol versus cimetidine on tolmetin-induced mucosal injury to the stomach and duodenum.

Ninety normal volunteers were entered into a double-blind, placebo-controlled study to compare the efficacy of misoprostol (200 micrograms q.i.d.) vs. cimetidine (300 mg q.i.d.) in protecting the gastric and duodenal mucosa from tolmetin-induced (400 mg q.i.d.) injury. After 6 days of treatment, the degree of mucosal injury between treatments was compared by endoscopy, using a predetermined rating scale of 0 (normal mucosa) to 4+ (greater than 25 hemorrhages or erosions or an invasive ulcer). Utilizing a score of less than or equal to 2+ (2-10 hemorrhages or erosions) as a therapeutic success, the overall success rates were 8/30 (26.7%) for placebo, 19/30 (63.3%) for cimetidine, and 27/29 (93.1%) for misoprostol (p less than 0.001). Pairwise comparisons were also significant: misoprostol vs. placebo (p less than 0.001), misoprostol vs. cimetidine (p = 0.006), and cimetidine vs. placebo (p = 0.004). A separate analysis of the gastric scores alone revealed success rates identical to those in the overall evaluation; however, success rates in the duodenum for both misoprostol (29/29) and cimetidine (29/30) were extremely high and did not differ. It is concluded that misoprostol is highly effective and significantly better than cimetidine in protecting the gastric mucosa from tolmetin-induced injury; however, both agents were highly protective in the duodenum.

Adult↗
PubMed1987

The effect of calcium antagonists on allergic pulmonary distress in actively sensitized rats.

The induction of allergic pulmonary distress (APD) in ovalbumin sensitive rats can be used as a model of human allergic asthma. In this model, control animals exhibit a rapid decrease in minute volume (Vm) when challenged with ovalbumin (OA) by aerosol (3% solution). The present study compared the effects of pretreatment with calcium antagonists on the induction of APD. By the aerosol route of administration, 5 min before OA, verapamil HCl (6% solution) significantly (P less than 0.05) dampened the allergic response during all 12 min monitored. At an equivalent concentration, diltiazem HCl significantly (P less than 0.05) inhibited the response during 6 of 12 min, whereas nifedipine failed to significantly (P greater than 0.05) alter the response to OA. Verapamil and nifedipine proved to be equally effective in a dose-dependent manner against OA-induced APD, however, when administered orally (-60 min, 5, 10 or 20 mg/kg). At doses of 10 mg/kg and higher, both calcium antagonists consistently inhibited (P less than 0.05) the response. Diltiazem was inactive when administered orally at a dose as high as 20 mg/kg. The present data suggest that the calcium antagonists verapamil, nifedipine and diltiazem, can attenuate APD and therefore might be clinically active agents in the treatment of allergic asthma.

Administration, Oral↗
PubMed1984

Inhibition of anaphylactic histamine release and pulmonary distress in rats by nonspecific IgE.

Myeloma IgE, obtained from ascitic fluid of rats previously inoculated with the IgE-producing cell line IR-162, was administered in prophylactic and therapeutic regimens to rats passively and actively sensitized to ovalbumin. Administration of myeloma IgE prior to passive sensitization resulted in approximately 95% inhibition of anaphylactic histamine release and significant protection from anaphylactic pulmonary distress. Myeloma IgE treatment prior and subsequent to active sensitization brought about a 70-80% inhibition of anaphylactic histamine release. A similar pattern of protection was seen in animals that received 5 but not 3 weekly myeloma IgE treatments subsequent to active sensitization. These findings indicate that treatment with nonspecific IgE prior to sensitization is effective in blocking anaphylactic reactions but competition with cell-bound IgE in sensitized animals requires prolonged administration of relatively large quantities of 'nonsense' IgE.

Anaphylaxis↗
PubMed1982

Development of a new in vivo anaphylactic histamine release assay in rats.

A new method has been developed to detect antigen-induced histamine release in the blood of allergic rats. This in vivo model of systemic anaphylaxis has been utilized to evaluate drugs for histamine release inhibition activity. Compounds were administered by various routes at appropriate times prior to or concomitant with antigen challenge. One minute after challenge the rats were bled into tubes containing heparin and aminoguanidine. Histamine concentrations were determined by a radioenzyme technique after separation of the plasma. Experiments demonstrated that: (a) rats passively sensitized with reaginic serum exhibited elevated blood histamine upon i.v. antigen challenge in a reproducible and dose-dependent manner; (b) heat-treatment of the reaginic serum abolishes antigen-induced histamine release; and (c) antigen-induced histamine release is inhibited by disodium cromoglycate, in a dose-dependent manner and it is also inhibited by isoproterenol or isobutyl-methylxanthine.

Anaphylaxis↗
PubMedDate not supplied

The biological properties of aspartame. V. Effects on a variety of physiological parameters related to inflammation and metabolism.

Aspartame (APM), L-aspartyl-L-phenylalanine methyl ester, is a low calorie sweetening agent 180 times sweeter than sucrose. As part of a series of studies designed to determine the potential effects of ingestion of excesses of APM on a wide spectrum of physiological processes, experiments were conducted in which high multiples (mg/kg basis) of the projected maximum daily human intake (20 mg/kg) were administered intragastrically to laboratory rats. Doses up to 16 times the maximum intake had no effect on inflammation parameters including carrageenin-induced paw edema, connective tissue formation and adjuvant arthritis. APM, likewise, showed no antihistamine activity in vitro. Even higher multiples (up to 103 times) of the maximum intake had no effect on various parameters of carbohydrate and lipid metabolism. These results indicate that APM ingested in great excess would not be expected to significantly impair inflammatory processes nor influence carbohydrate and lipid metabolism.

Animals↗