Case-control study of lung cancer in Los Angeles county welders.

A case-control study of lung cancer in white male welders was undertaken to investigate possible environmental and occupational causes of a 50% excess of lung cancer observed in this occupational group. The subjects were identified from a population-based cancer registry in Los Angeles County. A standardized questionnaire was administered to either subjects or proxy informants of 90 lung cancer cases and 116 non-lung-cancer controls. Significantly increased risks of lung cancer were associated with tobacco smoking (odds ratio 7.6, p less than .005) and shipyard welding with at least a 10-year latency since first exposure (odds ratio 1.7, p less than .05). Although there were elevated risks associated with some specific welding processes, none were statistically significant. Control subjects were more likely to have had exposure to confined-space welding (odds ratio 0.6, 95% CI = 0.3-1.2), and this association was greatest where there had been at least a 20-year latency since first exposure (0.5, 95% CI = 0.3-1.0). We conclude that the excess of lung cancer in this welding population is contributed to by a higher frequency of smoking and probable exposure to asbestos in shipyards. Other factors may be important, but probably because of limited power and reliance on proxy information, this study failed to detect other statistically significant risks.

The host-parasite interface in molluscan schistosomiasis: biotin as a probe for sporocyst and hemocyte surface peptides.

Hemocytes of Biomphalaria glabrata mediate the internal defensive response which, in resistant snail strains, kills sporocysts of Schistosoma mansoni. Lacking a gut, the sporocyst has only its tegument to interact with the host milieu (hemolymph). We have, therefore, focused our study on the surface-exposed proteins of hemocytes and sporocyst tegument. Using gentle biotinylation of living systems, labelled proteins were studied after SDS-PAGE electrophoresis and transfer to nitrocellulose. Results validate the utility of surface biotinylation in studies of host and parasite interfaces. A low diversity characterizes hemocyte surfaces and strain-specific differences are not in evidence. Hemocyte surfaces differ distinctly from the plasma in which these cells reside. In contrast, sporocyst surfaces expose a wide variety of peptides. These are remarkably stable even when sporocysts procured in snail plasma-free media are exposed to plasma. Thus, antigenic differences seen previously when Western immunoblotting was used to study sporocyst surfaces appear to be manifestations of minor changes in the exposed peptides or changes not detectable with this methodology. Hemoglobin, acquired by sporocysts from snail plasma, is processed and disappears from the surface during an overnight chase in culture medium.

Alfentanil for caesarean section complicated by severe aortic stenosis. A case report.

Alfentanil 35 micrograms kg-1, was used successfully in a patient with severe aortic stenosis, in order to minimize the haemodynamic responses to intubation and surgery during Caesarean section. The baby was delivered apnoeic, unresponsive and with poor muscle tone, but responded rapidly to naloxone. Plasma alfentanil concentrations and percentage binding to plasma proteins were measured in both maternal and neonatal blood. Free drug concentrations were similar in both mother and neonate, but maternal plasma proteins had a higher affinity for alfentanil. Only 67.26% of neonatal plasma alfentanil was bound to plasma protein. This value did not differ significantly from those estimated from the blood of a further 12 healthy neonates.

Phaeochromocytoma. Diagnosis, preoperative preparation and anaesthetic management.

Unless patients harbouring this uncommon tumour are correctly prepared and protected from the effects of excessive catecholamine release, they are greatly at risk when undergoing surgical procedures of any kind. This short review describes the clinical syndromes associated with phaeochromocytoma, the diagnostic procedures which may identify and localize the tumour(s), the principles and practical aspects of pharmacological control, and a method of anaesthetic management which has proved safe and effective in many patients.

A clinical trial of alfentanil as an adjuvant for short anaesthetic procedures.

Alfentanil 700 micrograms and fentanyl 100 micrograms were compared as anaesthetic adjuvants in 90 patients undergoing short duration gynaecological procedures. The results show that, at the chosen dose ratio, alfentanil causes a higher frequency of post-induction apnoea, but thereafter the respiratory effects of the two drugs were comparable. No differences in incremental requirements or evoked movements were found. Among patients who had been given ergometrine, the alfentanil group suffered a greater frequency of nausea and vomiting in the period immediately after operation. It is concluded that in single i.v. doses, alfentanil 700 micrograms is more potent than fentanyl 100 micrograms. Moreover, the results suggest that, unlike fentanyl, this very short acting agent would be used to greater effect if given in divided doses during surgery.

PIP: This study used a double-blind, randomized procedure to compare alfentanil with fentanyl as an adjuvant to anesthesia for short gynecological procedures. 90 healthy female patients age 16-65 years and weighing between 40-80 kg who were undergoing dilatation and curettage (D and C), evacuation of the products of conception (ERPC), or suction termination of pregnancy (TOP) were randomly assigned to group A (alfentanil) or group F (fentanyl). All patients were premedicated with lorazepam 1 mg. Each patient received either fentanyl 100 mcg or alfentanil 700 mcg, followed immediately by 1% methohexitone (plus 0.1% lignocaine) given in 10 mg increments every 15 seconds until the eyelash reflex was obtunded. The patients then breathed 66% nitrous oxide in oxygen. Patients undergoing TOP or ERPC were given ergometrine .25 mg intravenously at the start of cervical dilatation. Throughout the procedure, an online HP-8S computer gathered data on a peripheral interrupt basis. Data from the D and C patients was treated separately from that for TOP and ERPC patients; marked differences were found in incremental requirements for methohexitone, the frequency of apnea, the observed respiratory rates, and the mean arterial pressure. In both D and C and TOP groups, the mean induction doses of methohexitone in group F patients exceeded those in group A, but the differences were not significant, indicating that the analgesic effects did not differ greatly in intensity. The frequency and duration of apnea following induction were greater in patients given alfentanil. Despite the high frequency of apnea in group A patients, the frequency of physical responses to surgery and the need for incremental methohexitone did not differ. The results suggest that alfentanil does not improve the quality of anesthesia and does not discernibly reduce recovery time or the frequency of immediate postoperative nausea and vomiting.

Extradural versus intramuscular diamorphine. A controlled study of analgesic and adverse effects in the postoperative period.

The effects of diamorphine hydrochloride 0.1 mg/kg, given either extradurally or intramuscularly for postoperative analgesia were compared in two randomised double-blind studies involving 39 patients undergoing thoracotomy and major gynaecological surgery. Assessments were made at fixed intervals after the administration of diamorphine and consisted of the measurement of pain or analgesic effect. Segmental, sympathetic and any adverse effects were sought. There was no significant difference in the quality of analgesia between the two groups in either trial. Extradural diamorphine provided safe and effective analgesia of rapid onset, with no specific undesirable side-effects. In both studies, analgesia was more prolonged following extradural administration. The relative proportion of spinal binding may be increased after extradural administration and this may be reflected in the prolonged analgesia observed.