Biomedical subjects
Publications and source records attributed to J Curran.
In its most severe form tetanus is treated with prolonged use of neuromuscular blockade, and artificial ventilation. We report a case in which the use of dantrolene sodium shortened the period of artificial ventilation.
There are sequences homologous to 5S ribosomal RNA in the ribosomal DNA (rDNA) repeats of the plant-parasitic nematode Meloidogyne arenaria. This is surprising, because in all other higher eukaryotes studied to date, the genes for 5S RNA are unlinked to and distinct from a tandem rDNA repeat containing the genes for 18S, 5.8S, and 28S ribosomal RNA. Previously, only prokaryotes and certain "lower eukaryotes" (protozoa and fungi) had been found to have both the larger rRNAs and 5S rRNA represented within a single DNA repeat. This has raised questions on the organization of these repeats in the earliest cell (progenote), and on subsequent evolutionary relationships between pro- and eukaryotes. Evidence is presented for rearrangements and deletions within Meloidogyne rDNA. The unusual life cycles (different levels of ploidy, reproduction by meiotic and mitotic parthenogenesis) of members of this genus might allow rapid fixation of any variants with introduced 5S RNA sequences. The 5S RNA sequences in Meloidogyne rDNA may not be expressed, but their presence raises important questions as to the evolutionary origins and stability of repeat gene families.
Forty healthy adults who underwent rapid sequence induction of anaesthesia were allocated randomly to receive either cricoid pressure or its stimulation. The anticipated increase in systolic arterial pressure and heart rate after laryngoscopy and tracheal intubation were not altered significantly by the application of cricoid pressure.
The sensitivities, specificities, and positive and negative predictive values of the Cambridge BioScience Corp. (Worcester, Mass.) human immunodeficiency virus latex agglutination assay were compared by using three different blood preparations. By using the manufacturer's standard test method with diluted sera, the sensitivity of latex agglutination was 100%, the specificity was 99.58%, and the positive and negative predictive values were 99.26 and 100%, respectively. Use of diluted whole blood or undiluted whole blood did not significantly affect the sensitivity (mean, 99.72%), specificity (mean, 99.47%), positive predictive value (mean, 99.07%), or negative predictive value (mean, 99.89%). The latex agglutination assay is a simple, rapid assay for the detection of human immunodeficiency virus that would be useful in Third World countries or other areas where enzyme-linked immunosorbent assays are not available or cannot be used.
The epitopes of a panel of five monoclonal antibodies to the Sendai virus P protein were mapped by generating modified forms of the P mRNA via SP6 expression followed by in vitro translation. The epitopes were found to be clustered in the C-terminal region of the protein. Two epitopes were within the last 30 residues, two were within the next 65, and one was between residues 308 and 451 of this 568-residue-long protein. By a combination of partial proteolysis and Western immunoblotting with one of these antibodies, the sites at which phosphates are added in vitro by the virion-associated kinase were mapped to the second quarter of the molecule from the N terminus.
Two groups of patients with cystic fibrosis were compared. The screened group, detected with an improved neonatal screening assay for immunoreactive trypsin, developed fewer chest infections requiring treatment and gained more weight than the unscreened group. Early diagnosis by screening seems to affect early morbidity.
The sensitivity and specificity of an enzyme-linked immunosorbent assay (ELISA), absolute numbers of T-helper cells, and T-helper: T-suppressor cell ratios were compared in asymptomatic controls and IgG Western blot-confirmed patients with the acquired immune deficiency syndrome (AIDS) in Kinshasa, Zaire, between August 1984 and May 1985. Two hundred sixteen (97.7%) of 221 IgG Western blot-positive AIDS patients and 4 of 97 (4%) controls were ELISA-positive, 3 of whom were Western blot-positive. The sensitivity and specificity of the ELISA was 97.7% and 99.0%, respectively, compared to Western blot results. Detection of the human immune deficiency virus using absolute number of T-helper cells (less than 400 cells/mm3) was as sensitive (98.2%), but less specific (90.7%). A T-helper: T-suppressor ratio of less than 0.9, had a sensitivity of 97.3%, and specificity of 94.8%. The ELISA test had the highest predictive value and greatest utility in an African clinical setting for detecting HIV infected patients where a wide range of other immunocompromising diseases are seen.
To examine the genetic relatedness of human immunodeficiency viruses (HIV) from different geographic locations, we molecularly cloned the genome of HIV isolated from a Zairian AIDS patient. Restriction mapping of the recombinant clone, designated HIV-Zr6, revealed both common (as observed in other HIV isolates) and unique restriction sites. The DNA clone of HIV-Zr6, shown to give rise to infectious cytopathic virus after transfection of cultured lymphoid cells, was sequenced in several regions. The long terminal repeat (LTR), open reading frame 1 (ORF1), C-terminal envelope (env) gene domain, and ORF2 showed less than 6% difference in nucleotide sequence when compared to other HIV isolates including human T-lymphotropic virus-type III (HTLV-III) clone B10, lymphadenopathy-associated virus-1 (LAV-1), and AIDS-associated retrovirus-2 (ARV-2). About 15% difference in nucleotide sequences was noted in the N-terminal env gene domain. Alignments of env gene sequences revealed conserved, moderately variable, and hypervariable stretches in the predicted amino acid sequences. This model provides a basis for assessing the significance of sequence variation on properties controlled by the viral Env glycoproteins such as cell tropism and immunogenicity.
The genetic diversity of the human immunodeficiency virus (HIV) isolated from transfusion-associated AIDS patients has been examined. Restriction enzyme mapping studies of integrated proviral DNA of donor and recipient origin demonstrated genomic variation between isolates. Analysis of the molecularly cloned viral genomes of one donor-recipient pair showed that virus from the recipient had restriction enzyme site differences from the donor, noticeably clustered in the env and orf-2 regions, and also had a greater number of restriction sites in common with the donor as well. These results suggest that HIV may undergo genomic variation in vivo. Comparison of donor-recipient viruses may further the understanding of the molecular basis for AIDS pathogenesis.
Structural heterogeneity in human immunodeficiency virus (HIV-1) isolates from different sources has been reported. In order to investigate if the virus exhibits heterogeneity in vivo, HIV-1 was isolated over a 3 year period (1983-1985) from a blood donor who progressed from the asymptomatic carrier state to frank AIDS. The HIV-1 specific proteins were characterized and compared by metabolic labelling and immunoprecipitation of infected cells and by Western blot analysis of gradient purified isolates. The data indicate polymorphism in the apparent size of gag gene-encoded p55 and env gene-encoded p41 proteins. The possibility of genomic variations was evaluated by studying the restriction enzyme polymorphism of integrated proviral DNA. Genetic diversity between 1983, 1984 and 1985 isolates was demonstrated by a change in the number and/or size of restriction fragments. In addition, genetic variation was also observed in HIV-1 isolated from the blood transfusion recipient of this donor. Subsequent analysis of the quantitative and qualitative titre of HIV-1 specific antibodies in the donor recipient sera demonstrated a concomitant change with the observed structural variation in the virus. These studies may be useful in elucidating virus or host-related critical events which lead to the onset of AIDS following infection with HIV-1.
Twelve patients with progressive systemic sclerosis (four with CREST [calcinosis, Raynaud's phenomenon, esophageal dysmotility, sclerodactyly, and telangiectasia] variant) underwent systematic evaluation to assess the esophagogastric effects of metoclopramide hydrochloride in this patient population. Esophageal manometry, esophageal radionuclide scintigraphy, solid-phase gastric emptying, and 24-hour esophageal pH monitoring were performed in all patients with and without metoclopramide. Metoclopramide improved lower esophageal sphincter pressure and reduced the gastric emptying delay and gastroesophageal reflux in most patients but had a less consistent effect improving esophageal transit or esophageal body pressures. Metoclopramide should be strongly considered in the pharmacologic approach to the gastroesophageal reflux-related complications of this disease.
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The practice of preoperative assessment in 24 departments of anaesthesia in Great Britain and Ireland was surveyed. Most departments had no rigid policies governing assessment, and many served several hospitals. There was little evidence that admission procedures of patients scheduled for surgery or the organisation of operating lists took account of the problems encountered by anaesthetists undertaking preoperative assessment. From the participating departments 415 anaesthetists completed a questionnaire of their individual practice. Most (57%) visited at least 80% of their patients preoperatively, but 22% saw less than 50% of patients. The detection of potential anaesthetic problems and the establishment of rapport with patients were highly rated reasons for conducting such visits. Failure to visit was often related to organisational defects within the hospital service, and anaesthetists saw little prospect of improving these defects. The demands created by the needs of preoperative assessment on the one hand, and the need for a rapid turnover of surgical patients and financial stringency on the other, conflict, and this conflict is not easily reconciled.
The distance between the tip of a tracheal tube and the carina was measured in twenty five patients who required tracheal intubation and artificial ventilation of the lungs. Two methods of evaluation of this distance--limited-optic bronchoscopy and chest X-ray--were compared. There was no significant difference between the distance measured by either method. The advantages of checking tracheal tube placement by fibre-optic bronchoscopy are discussed.
In this paper we describe the meiotic pairing behavior of two free duplications in Caenorhabditis elegans. sDp1 is a duplication of approximately 30 map units of the right portion of linkage group I including unc-74 to unc-54. This duplication pairs, recombines, and apparently segregates from one of the normal homologues. A second duplication, sDp2, is a duplication of approximately 15 map units of the left portion of the linkage group. sDp2 was not observed to recombine with the normal homologue but did suppress exchange between the two normal homologues in a sDp2/ ++/ dpy-5 unc-35 heterozygote. Although a number of free duplications have been described previously in Caenorhabditis elegans, none of these have been shown to pair with normal homologues. The meiotic behavior of the duplications described in this paper can be understood assuming the existence in C. elegans chromosomes of pairing sites of the type described in D. melanogaster chromosomes (I. Sandler 1956; Hawley 1980).
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