Biomedical subjects
Publications and source records attributed to S J Jackson.
Pregnancy has generally been considered a contraindication to laparoscopic cholecystectomy. The authors present a case of laparoscopic cholecystectomy in a 37-year-old patient who was 18 weeks pregnant. Laparoscopic cholecystectomy can be safely accomplished during pregnancy, provided that the open technique of insertion of the first cannula is used, and all subsequent trocars be inserted under direct vision.
Dendritic cells (DC) are members of a distinct family of bone marrow-derived leukocytes. DC are potent accessory cells for a number of T cell-mediated immune responses, including autologous and allogeneic mixed leukocyte reactions, and mitogen- and antigen-stimulated lymphocyte proliferation. In the present study, DC purified from human peripheral blood were inoculated with various strains (IIIB, SF2, WMJ1, SF162, 89.6 and clone HXB2) of human immunodeficiency virus type 1 (HIV-1) displaying different patterns of cellular tropism. Viral replication was demonstrated by detection of p24 antigen (Ag) intracellularly and in culture supernatants, and by Southern and Northern blot analyses for the presence of HIV DNA and RNA, respectively, within infected cells. Cell-free and cell-associated p24 Ag levels rose substantially when DC were inoculated with strains SF162, 89.6 and clone HXB2. In contrast, p24 Ag levels rose only marginally after inoculation of DC with strains IIIB, SF2 and WMJ1. Purified DC did not express detectable membrane CD4, although CD4 mRNA was detected by reverse transcriptase PCR. The presence of anti-CD4 monoclonal antibodies failed to block infection of DC by any of the HIV strains tested, suggesting the existence of a CD4-independent alternative pathway of viral entry. The possibility that DC serve as a reservoir for HIV-1 must be considered.
The 1993 NRMP results reveal a 19% increase in positions filled in family practice residencies compared to 1992 (2,002 versus 1,658) and a 17% increase in positions filled by US seniors (1,636 versus 1,398). Similarly, 11% more positions were filled on July 1, 1993, than 1992 (2,798 versus 2,530). This confirms a trend begun in 1992 of increased interest in careers in family practice, reversing four years of declining interest from 1988 to 1991. Two hundred one fewer US seniors matched in internal medicine, while 36 more chose pediatrics. Of students entering residency training in the generalist disciplines, it is expected that 27% of the class of 1993 (LCME-accredited medical schools) will practice as generalists. An increase of 9% of first-year positions offered, and the development of 15% new ACGME-accredited family practice residency programs, could accommodate 20% of the nation's graduates of LCME- and AOA-accredited medical schools. With increasing interest in careers in family practice, increased support for the nation's family practice residency programs is critical.
Natural killer cell stimulatory factor (NKSF), or interleukin 12 (IL-12), is a heterodimeric lymphokine produced by B cells that has multiple effects on T and NK cell functions. NKSF at concentrations as low as 0.4 pM enhances the spontaneous cytotoxic activity of peripheral blood lymphocytes (PBL) against a variety of tumor-derived target cell lines and virus-infected target cells. The combined treatment of PBL with NKSF and IL-2 results in a less than additive enhancement of cytotoxicity. NKSF enhances the cytotoxic activity of spontaneously cytotoxic CD16+CD5- NK cells and does not confer cytotoxic activity to CD16-CD5+ T cells. PBL from patients infected with human immunodeficiency virus (HIV) have significantly lower cytotoxic activity against tumor-derived target cells and virus-infected target cells than PBL from control healthy donors. Treatment of PBL from HIV-infected patients with NKSF and/or IL-2 results in an increase of NK cell cytotoxicity against both types of target cells to levels similar to or higher than those of untreated PBL from healthy donors. PBL from HIV-infected patients produce interferon gamma in response to NKSF and/or IL-2, although at levels 5- or 10-fold lower than those produced by PBL from healthy donors. The multiple biological effects of NKSF, its activity at very low molar concentrations, and its ability to synergize with other physiological stimuli suggest that NKSF/IL-12 is a lymphokine likely to have physiological importance and considerable therapeutic potential.
Recent studies have shown that the University of Wisconsin (UW) solution may be superior to standard solutions in preserving the isolated heart before transplantation. The authors compared the UW solution with a modified Krebs-Henseleit solution in a continuous hypothermic coronary perfusion model. Hearts from mongrel dogs were rapidly excised after hyperkalemic arrest with standard cardioplegia and were mounted in a perfusion apparatus for 24 hours. Twelve hearts were perfused with the Belzer UW solution (group 1), and 15 hearts were perfused with a modified Krebs-Henseleit solution (group 2). The hearts were transplanted in a cross-circulation model, and parameters of function (developed pressure [dP] and rate of pressure development [+/- dP/dt]) were measured. Mean (+/- SEM) developed pressure was 80 +/- 7 mm Hg in group 1 and 56 +/- 9 mm Hg in group 2 (p less than 0.05). The +dP/dt was 1433 +/- 126 mm Hg/s in group 1 and 843 +/- 154 mm Hg/s in group 2 (p less than 0.005), and the -dP/dt was 958 +/- 110 mm Hg/s in group 1 and 676 +/- 106 mm Hg/s in group 2 (p less than 0.05). The UW-preserved hearts also required fewer defibrillations (0.75 +/- 0.13) to establish a stable rhythm than the control hearts (5.87 +/- 2.07, p less than or equal to 0.02). There were no significant differences in weight gain, coronary resistance or creatine phosphokinase levels between the two groups. The authors conclude that the UW solution provides better preservation of function than a modified Krebs-Henseleit solution for continuous coronary perfusion.
Eighty-six patients received orthotopic cardiac transplants at the Royal Victoria Hospital in Montreal between 1985 and 1989. Of these, 16 mortally ill, being sustained in hospital by the intravenous administration of inotropic agents (15 patients [94%]) or intra-aortic balloon counterpulsation (6 [38%]). There was one early death (at 7 days), for a death rate of 6.3% (versus 8.6% for the 70 "elective" transplants). Two others died of delayed infection: one of viral hepatitis at 6 weeks, and one of pneumonia due to Pneumocystis 4 months after transplantation. The other 13 patients are alive and well 12 to 66 months postoperatively. Nine have returned to their preoperative work, three have decreased activity levels but are functioning well, and one is retired.
Certain phthalate esters and hypolipidemic agents are known to induce morphological and biochemical changes in the liver of rodents, which have been associated with an increased incidence of hepatocellular tumors in these species. There is evidence that hypolipidemic agents do not induce these effects in either subhuman primates or man. The oral and intraperitoneal administration of di(2-ethylhexyl) phthalate (DEHP) to the marmoset monkey at doses up to 5 mmole DEHP/kg body weight/day for 14 days did not induce morphological or biochemical changes in the liver or testis comparable with those obtained in rats given the same amount of DEHP. In the marmoset, the excretion profile of [14C]-DEHP following oral, IP, and IV administration and the lower tissue levels of radioactivity demonstrated a considerably reduced absorption in this species compared to the rat. The urinary metabolite pattern in the marmoset was in many respects qualitatively similar to but quantitatively different from that in the rat; the marmoset excreted principally conjugated metabolites derived from omega- 1 oxidation. The pharmacokinetic differences between these two species indicate that the tissues of the marmoset are exposed to a level of DEHP metabolites equivalent to the complete absorption of a dose of Ca. 0.1 to 0.25 mmole DEHP/kg body weight/day without significant toxicological effects. These exposure levels are at least 100-fold greater than the worst estimates of incidental human exposure (ca. 0.0015 mmole/kg/day). They are comparable with the human therapeutic dose of many hypolipidemic drugs (ca. 0.15 mmole/kg/day), a dose at which it is claimed that there is an absence of morphological or biochemical changes to human or subhuman primate liver.(ABSTRACT TRUNCATED AT 250 WORDS)
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Previous studies in our laboratory have demonstrated that inhibition of prostaglandin biosynthesis through pretreatment with aspirin and other prostaglandin synthetase inhibitors (PGSI) significantly reduces CNS sensitivity to a hypnotic dose of ethanol. Indomethacin, a potent PGSI, was administered to male LS, SS, and HS/Ibg mice (65 +/- 10 days of age) 15 min prior to administration of a hypnotic dose of ethanol or pentobarbital. Doses of indomethacin used were identical to those previously reported as optimally antagonizing ethanol-induced sleep. Another group received a vehicle-control injection, while a third group also received a control injection, but were placed in a incubator maintained at 30 +/ 1 degrees C. Body temperatures were recorded periodically for several hours. Both indomethacin and incubation significantly reduced hypothermia induced by ethanol and pentobarbital. Incubation increased sleep time after ethanol, but did not affect pentobarbital sleep time. These results suggest that the hypnotic and hypothermic effects of ethanol, although possibly mediated through prostaglandins, apparently are not causally linked.
The pathogenesis of ischaemic neuronal damage along the arterial boundary zones of the forebrain was investigated in 20 lightly anaesthetized, spontaneously breathing baboons. A combination of bilateral common carotid artery occlusion and systemic hypoxia was used. An arterial PO2 of 21.2 +/- 2.5 mmHg was maintained for about 20 min. Additional occlusion of the left common carotid artery for 20 min had no effect on the EEG (except for one animal with a cerebrovascular anomaly). Only when occlusion of the right carotid artery was added did the EEG become almost or completely isoelectric after an interval ranging from 23 s to 44 min (sequential common carotid artery occlusion while breathing air did not affect the EEG). After a chosen period of electrical silence, hypoxia and carotid occlusion were terminated. Hypotension did not occur during carotid occlusion or the recovery period. Survival was deliberately limited to 46 h, during which neurological assessment was made and the EEG was recorded just before in vivo perfusion-fixation of the brain. Neurological deficits included asymmetrical quadriparesis and myoclonus epilepsy. The brains of 3 animals were normal and in the 15 with brain damage this was restricted in the cerebral cortex to the arterial boundary zones. In the presence of profound hypoxia the oligaemia due to bilateral carotid occlusion can reduce tissue oxygenation locally to a level critical for the production of ischaemic damage in the cortical boundary zones. Portions of the basal ganglia were also involved in 7. The quantified brain damage scores correlated with the EEG scored on a six-point scale during the perod of electrical silence and early recovery. Brain damage scores also correlated with the times for intracranial pressure to return to normal levels from the peaks recorded just after the end of arterial occlusion and hypoxia. As brain damage only occurred when the EEG during bilateral carotid occlusion and hypoxia was silent for at least 8 min, it was concluded that in a variety of clinical settings a simple EEG-based monitoring system would be optimal for the detection of an impending failure of cerebral oxygen supply.
The need for consumer health information delivery is becoming more evident to librarians. The results of a user survey at a large medical center library and a metropolitan public library confirm that the general public is making demands for health information at both types of libraries. Issues facing librarians are discussed; roles are suggested for public libraries, for academic health sciences libraries, and for hospital libraries. The importance of library involvement in the delivery of consumer health information is emphasized. Librarians are urged to define a role for themselves and to work hard at identifying the library profession to all others involved in the delivery of consumer health information.
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Development and implementation of the Biocommunications Network in the Memphis region have relied on sharing of resources among hospital libraries. Implied in this system is the recognition that all health care professionals have a right of access to health sciences libraries.
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