Pregnancy increases median nerve susceptibility to lidocaine

To determine whether pregnancy renders women more sensitive to local anesthetics, nine nonpregnant and nine pregnant (third trimester) women underwent median nerve block at the wrist using 1% lidocaine HCl. Inhibition of median nerve A alpha sensory and motor fibers was assessed using measurements of sensory nerve action potential (SNAP) amplitude and compound motor action potential (CMAP) amplitude, respectively. Inhibition of median nerve C fibers was assessed by the increase in skin temperature and by the decrease in median (relative to ulnar) galvanic skin potential (GSP) amplitude. Lidocaine inhibited SNAP to a greater extent in pregnant than nonpregnant women at all time points (P = 0.019). CMAP declined differently in the pregnant and nonpregnant groups (P = 0.01): the pregnant subjects achieved steady state inhibition before the nonpregnant subjects. The two groups developed comparable steady state inhibition. Skin temperature was higher in pregnant women at all time points (P less than 0.0001); moreover, the increased skin temperature of pregnant women differed from that of the nonpregnant women (P = 0.037), reflecting a more rapid temperature increase in the pregnant women. GSP amplitude declined to 50% of control more rapidly in pregnant (mean = 4 min) than nonpregnant women (mean = 11.5 min), but these differences did not achieve statistical significance. It is concluded that pregnancy increases median nerve susceptibility to lidocaine.     

Clonal evolution of T-cell chronic lymphocytic leukaemia in a patient with ataxia telangiectasia

Ataxia telangiectasia (A-T) is an autosomal recessive disorder in which patients show an unusual predisposition to malignant disease, including T-cell chronic lymphocytic leukaemia. We report here the steady growth over 5 years of a complex, cytogenetically abnormal clone of T lymphocytes in an A-T patient who was subsequently found to have an OKT3/OKT8 chronic lymphocytic leukaemia. The tumour cells at diagnosis had clearly evolved from a pre-existing, cytogenetically abnormal T-cell clone which contained an inv(14) chromosomal inversion alone.     

Assessment of the covalent binding potential of 2,2,4-trimethylpentane to rat alpha 2u-globulin

Subchronic exposure of male rats to the nephrotoxin 2,2,4-trimethylpentane (TMP) causes an accumulation of protein droplets in the epithelial cells of the renal cortex. Experimental evidence suggests that these droplets contain alpha 2u-globulin, a low-molecular-weight protein found specifically in the urine of male rats. It has been proposed that aldehyde metabolites of TMP form Schiff base adducts with the lysine groups of alpha 2u-globulin and thereby inhibit renal lysosomal processing of the protein. Accordingly, the ability of TMP and its metabolites to covalently bind to alpha 2u-globulin was examined. As a model, a [14C] formaldehyde-alpha 2u-globulin Schiff base was formed. This protein adduct was stabilized by reduction with cyanoborohydride and could be identified by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). Protein analysis by SDS-PAGE demonstrated that hepatocytes isolated from male Fischer-344 rats produced significant quantities of alpha 2u-globulin in culture, whereas hepatocytes from female rats did not. A 15-hr exposure of metabolically competent, primary cultures of male rat hepatocytes to [14C] TMP (0.1 and 0.5%, v/v), followed by reduction with cyanoborohydride, dialysis, and analysis with SDS-PAGE, revealed no evidence of radiolabeled alpha 2u-globulin. When [14C]TMP was administered to an adult male Fischer-344 rat (300 mg/kg, ig) 22, 16, and 10 hr before sacrifice, 16% of the administered radioactivity was eliminated in the urine as TMP metabolites. Analysis as above showed no TMP-derived radioactivity in fractions containing alpha 2u-globulin from liver, blood, kidney cortex, or urine. The absence of a detectable covalent interaction between TMP and alpha 2u-globulin following in vitro or in vivo exposure suggests that a TMP-alpha 2u-globulin adduct is not responsible for the excessive formation of protein droplets in the renal cortex of exposed male rats.     

Generating research in mental health nursing

This paper explores a number of areas for research development in mental health nursing in the United Kingdom. Several potential areas are identified: historical research, policy related research, the role of mental health nurse as a provider of a therapeutic milieu, as therapist and as teacher. Academic centres are identified in mental health nursing research and a plea is made for the preservation of valuable archive data being lost as mental hospitals are closed. Nurse leaders in mental health nursing are encouraged to make particular provision for research activity.     

Fusion beats and their relation to the syndrome of short P-R interval associated with a prolonged QRS complex

Fusion ventricular complexes were produced in animals by a method which allows accurate spacing of stimuli over short time intervals in successive cardiac cycles. The time during which fusion occurs was found to approach closely, but not quite equal, the time of the normal QRS complex.The clinical aspects of fusion beats were mentioned, and their relation to the syndrome of short P-R interval with wide QRS complexes was indicated.     

Female Gender Associates with Increased Duration of Intubation and Length of Stay after Coronary Artery Surgery

Background: Females have worse outcome than do males after coronary artery bypass grafting; however, gender effects on length of stay (LOS) outcomes, such as duration of intubation or intensive care unit (ICU) LOS, have not been evaluated previously. The authors hypothesized that adjustment for pertinent preoperative covariates would eliminate any significant effect of gender on duration of intubation, LOS in the ICU after extubation, total ICU LOS, postoperative (exclusive of ICU) LOS, or total postoperative LOS.

Methods: Patients undergoing elective or urgent primary coronary artery bypass grafting surgery at 51 academic health centers in 1995 and 1997 were studied. Unique multivariable statistical models were developed for duration of intubation, ICU LOS after extubation, total ICU LOS, and postoperative (exclusive of ICU and total) LOS to test for independent associations with gender. Preoperative but not intraoperative or postoperative variables were included in the model. P >= 0.01 was considered significant.

Results: All LOSs were of significantly longer duration in females than in males in both the 1995 (n = 1,064) and 1997 (n = 910) data collections. After covariate adjustment, female sex remained associated with significantly longer duration ICU LOS and total postoperative LOS in both the 1995 (female:male ratios 1.30:1 and 1.13:1, respectively) and the 1997 (female:male ratios 1.19:1 and 1.12:1, respectively) data sets. After covariate adjustment, duration of intubation and ICU LOS after extubation were of significantly longer duration in women than men in 1995 (female:male ratios 1.22:1 and 1.39:1, respectively), but the differences were not significant in 1997.