Diamorphine-bupivacaine mixture compared with plain bupivacaine for analgesia

We have studied the efficacy of two extradural infusions (10 ml h-1) in 50 patients in active labour. Patients in the diamorphine group (n = 25) received 0.0625% plain bupivacaine 6.25 mg h-1 mixed with 0.005% diamorphine 0.5 mg h-1 and those in the control group (n = 25) received 0.125% plain bupivacaine 12.5 mg h-1. Both groups received intermittent "top-ups" of 0.25% bupivacaine 10 ml when indicated. Although median pain scores during the infusion were similar in both groups, patients in the diamorphine group indicated greater satisfaction with the infusion (88% very satisfied, compared with 52% in the control group (P < 0.02)). There were no differences in the incidence of hypotension, instrumental vaginal delivery, number of "top-ups", duration of the second stage or extent of motor block. However, patients in the diamorphine group had a high incidence of pruritus (44%, compared with 0% in the control group (P < 0.01)).     

Higher incidence of Gastrospirillum sp. in swine with gastric ulcer of the pars oesophagea

Gastric ulcer in swine is characterized by an area of acid-peptic digestion, occurs usually in the pars oesophagea of the stomach, and has unknown etiopathogenesis. The present work was carried out to investigate the prevalence of the newly described spiral-shaped microorganism Gastrospirillum sp. ("Gastrospirillum suis") in stomachs of abattoir pigs with and without gastric ulcer. Stomachs were removed from 32 consecutive pigs presenting apparently normal mucosa and from 32 additional consecutive pigs presenting frank, chronic gastric ulcer of the pars oesophagea. Fragments of antral, oxyntic, cardiac and pars oesophagea regions were taken from each stomach and processed for histology and for identification of Gastrospirillum sp. in tissue sections. The microorganisms were identified mainly in the mucous layer and in gastric foveolas of the antral and oxyntic mucosa. Forty pigs (62.5%) were positive for Gastrospirillum sp.; among them, 27 (67.5%) had gastric ulcer, and 13 (32.5%) had no ulcer. Twenty-four pigs (37.5%) were negative for Gastrospirillum sp.; among them, five (20.8%) presented with gastric ulcer, and 19 (79.2%) had no ulcer. There was a significant difference between pigs with and without gastric ulcer in regard to the presence of Gastrospirillum sp. (P < 0.01). The spiral-shaped microorganism Gastrospirillum sp. that inhabits the stomach of pigs should be considered a possible factor connected with the etiopathogenesis of swine gastric ulcer.     

Homophobia? No, homoprejudice

The ubiquitous expression of anti-homosexual responses and the lack of consensus regarding the characterization of such responses served as the impetus for this study. The purpose of this study was to investigate the nature of anti-homosexual responses as reported by male and female undergraduates. Participants in the study were asked to respond to both a lesbian and a gay target questionnaire. Responses were measured as either phobic or prejudicial. Findings indicated that there is little, if any, evidence to support the characterization of anti-homosexual responses as a phobia. Responses to prejudicial items suggested that anti-homosexual responses lie primarily within the realm of prejudice. Results also indicated that males were less tolerant than females of gays and lesbians and males and females respond differentially according to same-sex target. The implications of using a more accurate term such as "homoprejudice" to characterize anti-homosexual responses are discussed. Additionally, avenues for future research are addressed.     

Somatic mosaicism in a patient with neurofibromatosis type 1

Using loss of heterozygosity analysis, a method designed to detect moderate to large gene deletions, we have identified a new-mutation neurofibromatosis type 1 (NF1) patient who is somatically mosaic for a large maternally derived deletion in the NF1 gene region. The deletion extends at least from exon 4 near the 5' end of the gene to intron 39 near the 3' end. The gene-coding region is, therefore, mostly or entirely deleted, encompassing a loss of > or = 100 kb. We hypothesize that the deletion occurred at a relatively early developmental timepoint, since signs of NF1 in this patient are not confined to a specific body region, as seen in "segmental" NF, and since both mesodermally and ectodermally derived cells are affected. This report provides the first molecular evidence of somatic mosaicism in NF1 and, taken together with a recent report of germ-line mosaicism in NF1, adds credence to the concept that mosaicism plays an important role in phenotypic and genetic aspects of NF1 and may even be a relatively common phenomenon.     

An approximate model and empirical energy function for solute interactions with a water-phosphatidylcholine interface

An empirical model of a liquid crystalline (L alpha phase) phosphatidylcholine (PC) bilayer interface is presented along with a function which calculates the position-dependent energy of associated solutes. The model approximates the interface as a gradual two-step transition, the first step being from an aqueous phase to a phase of reduced polarity, but which maintains a high enough concentration of water and/or polar head group moieties to satisfy the hydrogen bond-forming potential of the solute. The second transition is from the hydrogen bonding/low polarity region to an effectively anhydrous hydrocarbon phase. The "interfacial energies" of solutes within this variable medium are calculated based upon atomic positions and atomic parameters describing general polarity and hydrogen bond donor/acceptor propensities. This function was tested for its ability to reproduce experimental water-solvent partitioning energies and water-bilayer partitioning data. In both cases, the experimental data was reproduced fairly well. Energy minimizations carried out on beta-hexyl glucopyranoside led to identification of a global minimum for the interface-associated glycolipid which exhibited glycosidic torsion angles in agreement with prior results (Hare, B.J., K.P. Howard, and J.H. Prestegard. 1993. Biophys. J. 64:392-398). Molecular dynamics simulations carried out upon this same molecule within the simulated interface led to results which were consistent with a number of experimentally based conclusions from previous work, but failed to quantitatively reproduce an available NMR quadrupolar/dipolar coupling data set (Sanders, C.R., and J.H. Prestegard. 1991. J. Am. Chem. Soc. 113:1987-1996). The proposed model and functions are readily incorporated into computational energy modeling algorithms and may prove useful in future studies of membrane-associated molecules.     

Autoantibodies to the insulin receptor. Effect on the insulin-receptor interaction in IM-9 lymphocytes

The serum of some patients with insulin-resistant "diabetes" contains antibodies that bind to and block the cell membrane receptors for insulin. In this report, we have characterized the effects of the antireceptor antibodies on the interaction of (125)I-insulin with its receptor on the human lymphoblastoid cell line IM-9. Up to 95% of specific insulin binding can be inhibited by pretreatment of the cells with these immunoglobulins. The onset of the inhibitory effect is time- and temperature-dependent, and the effect is reversed extremely slowly if the cells are suspended in a large excess of antibody-free buffer. These features of antibody binding can be easily distinguished from those for insulin binding to its receptor. The inhibitory effect of the antibodies can be reversed by exposure of the cells to conditions known to elute surface immunoglobulins. The three antireceptor sera studied appear to alter the insulin-receptor interaction in different ways. Two antisera markedly reduce receptor affinity through combined effects on the insulin association and dissociation rates, and, additionally, have smaller effects on available receptor number. A third antiserum primarily affects available receptor number and has little effect on receptor affinity. All three antisera inhibit the capacity of insulin to promote negatively cooperative site-site interactions among insulin receptors. The data suggest that these autoantibodies to the insulin receptor bind to different determinants on the receptor and may therefore be useful as unique probes of insulin receptor structure and function.     

Experimental automobile-pedestrian injuries

Fifteen fresh cadaver impacts were conducted in simulation of pedestrian-automobile accidents. The test sled configuration simulated an automobile bumper and hood in "standard" and "nosedive" situations as well as "hard" and "soft" impact surfaces. Instrumentation and film demonstrated large axial compression forces in the struck leg and considerable angular velocity of the torso in all modes. Dissection revealed primary injury at the impact site at low velocities with added remote injury at high velocities. Fracture of the lateral tibial plateau was most common. Lowering the bumper height offered the greatest protection against injury at moderate impact velocities.     

Licorice-induced hypertension and syndromes of apparent mineralocorticoid excess

Excessive ingestion of licorice induces a syndrome of hypokalemia and hypertension that reflects increased activation of renal mineralocorticoid receptors by cortisol. A similar syndrome of cortisol-dependent mineralocorticoid excess occurs in congenital deficiency of the enzyme 11 beta-hydroxysteroid dehydrogenase, which normally inactivates cortisol to cortisone. It has been shown that licorice inhibits 11 beta-dehydrogenase, preventing local inactivation of cortisol and allowing cortisol inappropriate access to intrinsically nonspecific renal mineralocorticoid receptors. Further studies with licorice and its derivatives have revealed a widespread role for 11 beta-dehydrogenase in regulating tissue sensitivity to cortisol. Deficient 11 beta-dehydrogenase activity provides a novel pathogenetic mechanism for hypertension, and current research suggests that several common forms of hypertension can be explained by the mechanisms that operate in licorice-induced hypertension.