Omission of Nitrous Oxide during Anesthesia Reduces the Incidence of Postoperative Nausea and Vomiting: A Meta-Analysis

Background: Postoperative nausea and vomiting are important causes of morbidity after general anesthesia. Nitrous oxide has been implicated as an emetogenic agent in many studies. However, several other trials have failed to sustain this claim. The authors tried to resolve this issue through a meta-analysis of randomized controlled trials comparing the incidence of postoperative nausea and vomiting after anesthesia with or without nitrous oxide.

Methods: Of 37 published studies retrieved by a search of articles indexed on the MEDLINE database from 1966 to 1994, 24 studies (26 trials) with distinct nitrous-oxide and non-nitrous oxide groups were eligible for the meta-analysis. The pooled odds ratio and relative risk were calculated. Post hoc subgroup analysis was also performed to qualify the result.

Results: The pooled odds ratio was 0.63 (0.53 to 0.75). Omission of nitrous oxide reduced the risk for postoperative nausea and vomiting by 28% (18% to 37%). In the subgroup analysis, the maximal effect of omission of nitrous oxide was seen in female patients. In patients undergoing abdominal surgery and general surgical procedures, the effect of omission of nitrous oxide, although in the same direction, was not significant.     

Incidence of Australia antigen in leprosy

Ninety seven male patients attending the Leprosy clinic of the Dermatology Out-patients' Department were studied for the detection of Australia antigen. There was a 20% antigen positivity in patients suffering from Lepromatous Leprosy and 5.7% in the cases with Tuberculoid Leprosy. SGPT level was found to be significant in patients with Lepromatous Leprosy having Australia antigen as compared to other groups.     

Influence of cannabis and delta-9-tetrahydrocannabinol on the biochemistry of the male reproductive organs

Studies have been made on the effect of repeated subcutaneous administration of cannabis extract and delta-9-tetrahydrocannabinol on the fructose and citric acid contents of male reproductive organs of prepubertal as well as adult albino rats. Results indicate that both the fructose and the citric acid contents of the male reproductive organs are reduced significantly by cannabis. The reduction further appears to be dose-related to the amount of THC being administered, in case of both young and adult rats. Thus the study corroborates the previously reported antitestosteronic action of the drug.     

Stapedius reflexometry: A diagnostic test of myasthenia gravis

Contraction of the stapedius muscle can be measured by electroacoustic impedance bridge. Muscle weakness and easy fatiguability which are cardinal features of myasthenia gravis (MG) are manifested by increased threshold and early decay of the stapedius reflex. This can be used as an objective test in the diagnosis of myasthenia gravis. Stapedius reflex was measured using Madsen Zo72 electroacoustic impedance bridge in 10 patients with myasthenia gravis and in an equal number of controls. The test was done before and 30 min after intramuscular injection of neostigmin.All patients with myasthenia gravis showed an elevated reflex threshold and 5 patients showed reflex decay. These findings reverted to normal after neostigmin injection. Stapedius reflexometry is a simple objective test for the diagnosis of myasthenia gravis.     

Characterization of the phage-specific transfer RNA molecules coded by cholera phage phi 149

Aminoacylation of tRNA isolated from choleraphage phi 149-infected cells with individual 3H-labeled L-amino acids followed by hybridization with phage DNA revealed that the phage encodes tRNAs specific for arginine, proline, glycine, isoleucine, serine, valine, tyrosine, histidine, lysine, leucine, tryptophan, and aspartic acid. Aminoacylation of phage-coded tRNAs isolated from phage DNA-RNA hybrids also confirmed this observation except for tryptophan.     

Microinjury to the synovial membrane may cause disaggregation of proteoglycans in rabbit knee joint articular cartilage

Proteoglycans (PGs) isolated from articular cartilage (AC) of mature rabbits subjected to two or more consecutive intraarticular (IA) injections of sterile saline 24 h apart showed an aggregation defect in the presence of excess hyaluronic acid (HA). Although the PG contents of experimental and control cartilages were indistinguishable, a higher proportion of PGs were extractable from the 3 X IA tissues, as assessed by uronic acid analysis. Proteoglycans from experimental and control cartilages when examined by Sepharose CL-2B chromatography showed two subunit populations, the smaller (KAV = 0.70) containing more ketatan sulphate than the larger (KAV = 0.31). Cultures of AC from IA joints released more 35SO4-labelled PGs into the media over 72 h than control tissues and consisted mainly of PG degradation products although 20% could aggregate in the presence of HA. Examination of PG aggregation 2 weeks after 2 X IA or 3 X IA injections showed that the defect initiated was still present; however, cartilage of immature rabbits was not affected by the 2 X IA procedure.