Anesthesia induced retrograde amnesia is ameliorated by ephrinA5-IgG in mice: EphA receptor tyrosine kinases are involved in mammalian memory

EphA receptors and their ephrin-A ligands were previously thought to play a role only in embryonic development of the brain. Recently, however, these proteins were shown to be expressed in the adult mouse brain, primarily in the hippocampus, and were implicated in hippocampal synaptic plasticity and learning. What aspects of learning EphA receptors mediate have not been studied? Using the fear conditioning paradigm we demonstrate that EphA receptors play roles in memory. We show that post-training surgical anesthesia leads to robust context specific retrograde amnesia in mice, and post-anesthesia activation of EphA receptors induces a significant amelioration of this amnesia. As acquisition was left unaffected and performance factors were found unaltered, we suggest that the amelioration was due to changes in cognition leading to improved memory. Our data represent the first pieces of evidence for the involvement of EphA receptor tyrosine kinase receptors in mammalian memory, a finding that opens a new avenue into the functional analysis of the largest receptor tyrosine kinase subfamily in the brain.

Rapid diagnosis and identification of cross-over sites in patients with glucocorticoid remediable aldosteronism

Glucocorticoid remediable aldosteronism (GRA) is an autosomal dominant cause of primary aldosteronism and high blood pressure resulting from a chimeric 11beta-hydroxylase/aldosterone synthase gene. Abnormal expression of aldosterone synthase causes primary aldosteronism, which can be inhibited by glucocorticoids. Diagnosis of GRA has depended on the identification of a restriction enzyme product in genomic DNA of affected individuals. Recently, a two-tube long PCR method was described that allowed diagnosis of GRA in a kindred in Australia. A similar long PCR method confirmed the diagnosis of GRA in members of five northeastern Scotland families previously identified by Southern blotting and detected affected members of five GRA families previously identified in Glasgow. A multiplex PCR protocol is described here that allows the control aldosterone synthase amplification and chimeric gene amplification to be carried out in the same tube. We describe the regions of cross-over in each of 10 kindreds identified in Scotland. To identify cross-over regions in each of the kindreds, the chimeric long PCR product was cloned and sequenced. Five cross-over sites were identified ranging from intron 2 to exon 4, indicating the reliability of the method in identifying chimeric genes resulting from different sites of cross-over.

Covered lives and seamless systems: nursing workforce development and integration in Arizona's managed-care environment

Responding to demands that nursing leaders conduct business in creative proactive ways, the authors of this department share the work of The Robert Wood Johnson Foundation's national program, Colleagues in Caring: Regional Collaboratives for Nursing Work Force Development. The purpose of this initiative is to enhance regional and state collaborative planning and implement actions and policies to address the rapid changes occurring in the United States nursing labor market. This department, edited by Mary Fry Rapson, PhD, RN, CS, National Program Director and Rebecca B. Rice, EdD, RN, National Deputy Director, presents the ongoing work of the program, highlighting the work of the 20 individual collaboratives. Regional approaches to the expected program outcomes and specific challenges and opportunities that are unique to each region's environment are included.

Improved clinical outcomes with liver transplantation for hepatitis B-induced chronic liver failure using passive immunization

OBJECTIVE

The goals were to summarize the results of liver transplantation for chronic hepatitis B disease (HBV) at the University of Virginia, correlate pretransplant viral markers with posttransplant hepatitis B immunoglobulin (HBIg) requirements, and identify the relation between viral protein in the liver and clinical reinfection.

SUMMARY BACKGROUND DATA

Liver transplantation is an accepted treatment for end-stage liver disease from chronic HBV infection, although lifelong antiviral treatment (with HBIg or antiviral agents) is still necessary. Patients with evidence of active viral replication (detectable serum HBV-DNA or e antigen) at the time of transplant have a higher rate of allograft infection. Whether clinically stable patients receiving HBIg immunoprophylaxis have detectable viral products in their grafts remains unknown.

METHODS

Forty-four transplants performed for HBV disease at the University of Virginia since March 1990 were reviewed. Most patients underwent aggressive passive immunoprophylaxis with HBIg to maintain serum HBV surface antibody (HBsAb) levels > or =500 IU/l for the first 6 months after the transplant, and > or =150 IU/l thereafter. Patients had viral markers quantified, underwent pharmacokinetic analysis of HBsAb levels to adjust dosing, and were biopsied routinely every 3 to 6 months and when indicated.

RESULTS

Forty-four transplants were performed in 39 patients. Actual 1-year and 3-year graft survival was 95% and 81%, respectively, and 1-year and 3-year patient survival was 98% and 96%, respectively. After the adoption of indefinite HBIg prophylaxis, nine grafts became infected (all in recipients positive for HBV e antigen). Three occurred within 8 weeks of transplantation and were associated with a short HBsAb half-life and a wild-type virus. Six occurred >8 months after the transplant, and most of these were associated with viral mutation. Quantification of pretransplant markers was an overall poor predictor of HBIg requirements after the transplant. Immunohistochemistry demonstrated transient low-level expression of core protein in the liver in 23% of patients without serum or clinical evidence of recurrent hepatitis.

CONCLUSIONS

An excellent outcome is possible after liver transplantation for chronic HBV disease using HBIg dosed by pharmacokinetic parameters. Currently, quantification of pretransplant serum markers of the HBV antigen load does not predict the intensity of posttransplant treatment required for good clinical outcomes. Because HBV is not eradicated from the patient, some form of indefinite antiviral therapy continues to be warranted.

The Chlamydomonas zygospore: mutant strains of Chlamydomonas monoica blocked in zygospore morphogenesis comprise 46 complementation groups

Chlamydomonas monoica undergoes homothallic sexual reproduction in response to nitrogen starvation. Mating pairs are established in clonal culture via flagellar agglutination and fuse by way of activated mating structures to form the quadriflagellate zygote. The zygote further matures into a dormant diploid zygospore through a series of events that we collectively refer to as zygosporulation. Mutants that arrest development prior to the completion of zygosporulation have been obtained through the use of a variety of mutagens, including ultraviolet irradiation, 5-fluorodeoxyuridine, ethyl methanesulfonate, and methyl methanesulfonate. Complementation analysis indicates that the present mutant collection includes alleles affecting 46 distinct zygote-specific functions. The frequency with which alleles at previously defined loci have been recovered in the most recent mutant searches suggests that as many as 30 additional zygote-specific loci may still remain to be identified. Nevertheless, the present collection should provide a powerful base for ultrastructural, biochemical, and molecular analysis of zygospore morphogenesis and dormancy in Chlamydomonas.

The development of a comprehensive stroke programme in the acute hospital

Stroke is the third leading cause of death and an important cause of hospital admissions and long term disability. The incidence of stroke is estimated at 200 per 100,000 of the population, Dublin has approximately 2,400 new strokes per annum. In 1989 a comprehensive stroke programme was introduced in St Vincent's Hospital. The aim was to provide patients with a coordinated approach to rehabilitation. A study of the programme was conducted in 1993 by detailed chart review. 129 patients with a clinical diagnosis of stroke were referred to the programme during a 12 month period. 27.13% were under age 65 and 72.87% were over 65 years, 18% died and 44.2% were discharged home, independently mobile. The study findings suggest that the comprehensive stroke programme in St Vincent's Hospital represents a feasible model of care in the acute general hospital setting.

Chronic fenoterol exposure increases in vivo and in vitro airway responses in guinea pigs

We tested the hypothesis that the regular inhalation of a beta 2-adrenergic receptor (beta 2AR) agonist increases airway responsiveness in guinea pigs. A potent beta 2AR agonist, fenoterol hydrobromide, in sublaryngeal doses equivalent to maximal doses used in the treatment of asthma on a weight basis (5.28 micrograms/kg), was administered by nebulizer three times a day for 6 weeks to normal adolescent guinea pigs (FEN, n = 10) and to ovalbuminsensitized guinea pigs challenged twice weekly with ovalbumin (OA + FEN, n = 20), although not in the 12 h prior to or 4 h after antigen challenge. Controls included saline-treated normal animals (CON, n = 10) and ovalbumin-sensitized animals treated with repeated antigen challenge and saline (OA, n = 20). At 72 h after the last administration of saline, fenoterol, and ovalbumin, the dose-response relationship between pulmonary resistance (RL) and nebulized acetylcholine (ACh) was measured. RLmax increased 2-fold and the ACh concentration causing a 10-fold increase in RL (PC10) decreased 4-fold in the FEN, OA, and OA + FEN groups as compared to the CON group. In the FEN, OA, and OA + FEN groups, in vitro tracheal smooth-muscle contractile responses to maximal concentrations of acetylcholine increased 2-fold, and this increase was not due to increased smooth-muscle mass. There was no evidence for beta 2AR desensitization as judged by in vitro tracheal smooth-muscle relaxant responses to fenoterol. These results suggest that chronic beta 2AR stimulation increases airway smooth-muscle contractility and in vivo airways responsiveness to a degree similar to that induced by chronic antigen exposure. A similar effect in human asthmatics may explain the adverse effects observed during prolonged treatment with these drugs.

Detection of hepatitis C virus RNA in hemodialysis patients

The clinical significance of the high prevalence of antibodies to hepatitis C virus (HCV) in dialysis patients remains undefined. In order to assess the relationship between seropositivity and potential infectivity, 63 patients undergoing maintenance hemodialysis were evaluated between April and May 1990. The mean duration of maintenance hemodialysis was 45 mo (range, 13 to 144). Eighty-two percent (52 of 63) had received blood transfusions, and 16% (10 of 63) had a history of iv drug abuse. Serum samples were analyzed by HCV-cDNA polymerase chain reaction; antibodies to HCV structural (core) and nonstructural regions NS3 and NS4 were determined by enzyme immunoassay. Specimens repeatedly reactive for anti-HCV and HCV-RNA-positive samples were tested by HCV MATRIX dot immunoblot assay and HBV-DNA PCR. Twenty-five percent (16 of 63) were anti-HCV-positive. Of the 16 anti-HCV-positive patients, HCV-RNA was detected in 5 (31%) with the NS3 primers and in 12 (75%) with 5'-noncoding primers. Among the anti-HCV-negative patients, HCV-RNA was detected in 2 (4.3%) of 47 patients. Eleven of the 18 patients with HCV infection (anti-HCV and/or HCV-RNA-positive) had evidence of additional present or past viral infections (human immunodeficiency virus and/or hepatitis B virus). In summary, HCV-RNA is present in at least 75% of anti-HCV-positive patients, suggesting that they may be infectious. The detection of HCV-RNA in anti-HCV-negative patients may indicate early or chronic HCV infection not detected by current antibody assays or the inability of these patients to mount or sustain a significant antibody response.

Haemospermia: how to proceed?

Haemospermia is an alarming symptom but does it signify serious disease and how should it be investigated? A retrospective review of 44 men showed no evidence of malignancy and infection as the commonest cause. Standard investigation with midstream specimen of urine, intravenous pyelogram and cystoscopy is unhelpful. Microscopy and culture of a first stream specimen of urine or expressed prostatic secretions is the investigation of choice. Cystoscopy should be reserved for patients with recurrent haemospermia.

Serum and liver hepatitis B virus DNA in chronic hepatitis B after sustained loss of surface antigen

Polymerase chain reaction (PCR) was used to detect hepatitis B virus DNA in the sera and livers of nine patients with chronic hepatitis B after treatment-induced or spontaneous loss of serum hepatitis B surface antigen. Patients were evaluated at intervals ranging from 3 to 67 months after disappearance of hepatitis B surface antigen. PCR was performed using primer pairs from the surface and core gene regions, and surface gene products were quantitated. Liver tissue was also evaluated by in situ hybridization to assess viral transcription. Five of the nine patients had viral DNA detectable in serum by PCR. Quantitation of polymerase chain reaction products in serum and liver showed that the DNA levels tended to decline progressively after antiviral therapy. Six of seven surface antigen-negative patients tested had detectable viral DNA in the liver, and four of the six DNA-positive patients were negative for DNA in serum by PCR. None had surface gene messenger RNA. Thus, it is concluded that hepatitis B virus DNA may be detectable by PCR in liver tissue years after the disappearance of hepatitis B surface antigen, even in the absence of detectable hepatitis B virus DNA in serum.

Optimum duration of transtelephonic ECG monitoring when used for transient symptomatic event detection

Transtelephonic electrocardiographic monitoring (TTM) has been used for postpacemaker follow-up study, postmyocardial infarction monitoring, and transient symptomatic event detection (TSED). For postpacemaker follow-up study, TTM is continued indefinitely. For postmyocardial infarction monitoring, TTM is continued for 1 year or more. For TSED, the appropriate duration for TTM has not yet been adequately assessed. Accordingly, the authors determined the yield, by week, of TTM for TSED. Five thousand fifty-two patients who made 20,590 calls were analyzed for this investigation. Ninety-five percent of patients making symptomatic calls or making a call in which an arrhythmia was documented did so within 5 weeks. Shorter periods would sacrifice yield, longer periods may not be cost-effective.

Complement and antibody mediate enhancement of HIV infection by increasing virus binding and provirus formation

Previous studies have shown that infection of complement receptor (CR2)-bearing cells with HIV pretreated with antibody (Ab) plus complement (C) resulted in increased virus expression. The current study was designed to determine whether C-mediated 'enhancement' of HIV-1 production was the result of increased virus infection of cells as assessed by provirus formation and virus binding. Virus was incubated with anti-HIV Ab and/or C and added to CR2-positive MT-2 cells. Increased virus expression by MT-2 cells correlated with increased numbers of HIV-immunofluorescent-positive cells at 24 and 48 h and higher levels of provirus detected 8-28 h after infection. MT-2 cells also bound threefold more Ab-plus-C-treated virus than untreated virus. Serial dilutions of C showed that high levels of C with Ab did not enhance but rather suppressed virus expression. Studies were also performed which showed that terminal C components C5 and C8 were not necessary for the enhancing effect. The increased binding of C-coated HIV to CR-positive cells has important implications for the fate of virus in vivo.

Ambulation status of adults with myelomeningocoele

The current ambulation status of 87 adults with myelomeningocoele who had been ambulant with calipers as children was reviewed--23 patients were community ambulators, while 58 had become wheelchair-bound. The majority of patients in the study group found calipers uncomfortable to wear, and almost half of the group developed pressure sores directly related to their calipers.

Plasma dopamine-beta-hydroxylase and preschool behavior in children with conduct disorder

The preschool behavior history and a history of abuse or neglect were compared between emotionally disturbed boys with and without conduct disorder (CD), and between boys with high and low plasma dopamine-beta-hydroxylase (D beta H) activities and CD. Boys with CD had the expected increase in preschool behaviors associated with attention deficit disorder (ADD) and CD as well as more reports of abuse or neglect. A higher percentage of boys with low D beta H were reported to have preschool behaviors associated with ADD. In contrast, more high D beta H subjects were reported as abused or neglected.

Direct transfer of beta-glucuronidase from mouse macrophages to other types of cell

Rabbit polyclonal antibodies were raised against beta-glucuronidase purified from mouse liver. This antiserum immunoprecipitated the beta-glucuronidase secreted by mouse fibroblasts but did not cross-react with the same enzyme isolated from human tissue. The beta-glucuronidase present in mouse 3T3 fibroblasts and mouse peritoneal macrophages was clearly identified by indirect immunofluorescence, using the antiserum and an FITC-conjugated second antibody, while human fibroblasts with normal levels of beta-glucuronidase activity did not fluoresce when tested with the same reagents. A range of human fibroblasts, human neuroblastoma and rat glioma cells did not fluoresce when incubated with the antibody but did fluoresce after they had been co-cultured for 24 h with mouse macrophages, showing that mouse beta-glucuronidase had been transferred from adherent macrophages into adjacent recipient cells. Transfer took place even when receptor-mediated endocytosis was blocked with a suitable competitive ligand, the transferred enzyme being visible mainly as a bright punctate fluorescence with a lysosome-like distribution. Macrophages thus have the potential to act as donors of lysosomal enzymes to a wide range of recipient cells and to transfer enzymes to them during direct cell-to-cell contact.

Fibroblasts acquire beta-glucuronidase by direct and indirect transfer during co-culture with macrophages

Macrophages can transfer beta-glucuronidase directly to co-cultured fibroblasts during cell-to-cell contact as well as indirectly via receptor-mediated endocytosis. The degree of enzyme activity acquired by the deficient fibroblasts was determined by the ratio of donor to recipient cells and by the length of time for which cells were allowed to interact. Both mechanisms of transfer were efficient so that 70% of normal enzyme activity was restored to deficient fibroblasts after 24 h of co-culture. These observations show that macrophages have great potential as donor cells in replacement therapy for the treatment of inherited lysosomal enzyme deficiency diseases.

Scanning electron microscopy of the metal-tissue interface. II. Observations with lead, copper, nickel, aluminium, and cobalt

The nature of the metal-tissue interface following the implantation of five pure metals, lead, copper, nickel, aluminium and cobalt, in rats has been observed by scanning electron microscopy. The general conclusion, derived from light microscopy that the tissue response to pure metals is characteristic of and specific to individual pure metals has been confirmed in this study. However, far more detailed observations of factors such as the extent of metallic corrosion, the distribution of red blood cells, platelets and other cells in the capsule and adherent to the metal surface, have been possible with SEM.

Scanning electron microscopy of the metal-tissue interface. I. Fixation methods and interpretation of results

Scanning electron microscopy has been used to study the interface between implants of pure metals and the muscular tissue of rats. Several problems arise in the interpretation of the observations made, due to the potential for disruption to the tissue and the exacerbation of any corrosion that may have occurred in vivo during the fixation periods. Details are given of the control experiments performed in order to ascertain the nature of potential artefacts and of the techniques eventually determined to be optimal for these purposes.

The response to the intramuscular implantation of pure metals

Discs of five high-purity metals, cobalt, nickel, copper, aluminium and lead have been implanted intramuscularly in rats and the response observed histologically for period up to 52 weeks. A reproducible but different response was observed with each metal. Whenever corrosion occurred, as with copper, nickel and some cobalt specimens, the implants became loose. In the absence of corrosion, the implants were firmly held within a more confined capsule. A minimal response was seen with lead, implying normally toxic metals do elicit an immune response whilst some, especially copper and nickel appear to render the host more susceptible to disease. The implants appear to have a profound effect on the immediate vasculature, are able to cause a prolonged polymorphonuclear response in the same way as bacteria, are associated with varying amounts of haemosiderin laden macrophages but not with giant cells. The animals appear to be able to deal with bacteria introduced at surgery without hindrance from the metal.