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Biomedical subjects

A Murray

Publications and source records attributed to A Murray.

At least 307 records · Page 17Linked to original sources
PubMed1990

Clinical comparison of two devices for detection of microemboli during cardiopulmonary bypass.

Detection of gaseous microemboli during cardiopulmonary bypass procedures is important for the clinical evaluation of equipment such as oxygenators and cardiotomy reservoirs. Comparison of published data can be difficult if different detectors are used. Two devices reported in the literature, the Technique Laboratories TM-8 and the Hatteland BD-100, are compared during clinical procedures. The relationship between the outputs of these devices was linear over two ranges, the difference in output amounted to a standard deviation of 11% in the lower range and 38% in the upper range.

Cardiopulmonary Bypass↗
PubMed1990

Psychological consequences of the Enniskillen bombing.

Eleven people were killed and 60 injured in the Enniskillen bombing of November 1987. Survivors were psychologically appraised six months and one year later. At six months 50% had developed post-traumatic stress disorder (PTSD). This group comprised more females than males. However, all victims had high scores on the GHQ. We found no correlation between psychological injury (as measured by the GHQ) and physical injury (as measured by the ISS), calling into question previous assertions.

Adolescent↗
PubMed1990

Mixed connective tissue disease with arterial thrombosis, antiphospholipid antibodies and heparin induced thrombocytopenia.

We report a patient with mixed connective tissue disease (MCTD) who presented with thrombosis of the right femoral artery in association with antiphospholipid antibodies (aPL). When treated surgically and with heparin prophylaxis, she developed heparin induced thrombocytopenia and thrombosis which necessitated amputation of a lower limb. Thus our patient developed 2 separate groups of autoantibodies associated with thrombotic events. Our case highlights an association between thrombosis, aPL and MCTD. Furthermore, it emphasizes a need for intensive monitoring when hypercoaguable individuals with connective tissue disorders are treated with heparin.

Adult↗
PubMed1989

Gallstone lithotripsy with the pulsed dye laser: in vitro studies.

The use of a pulsed dye laser to fragment human gallstones is reported. Laser energy was delivered by a 320 microns quartz fibre at wavelengths of 440, 480, 504, 560, 590, and 635 nm, in 1 microsecond pulses at energies of 5-60 mJ per pulse, producing peak powers of the order of 10(5) W. Cholesterol, pigment and mixed stones were fragmented. The shorter wavelengths were most efficient, using significantly less energy at 440 and 480 nm than at the longer wavelengths. Pigment stones were fragmented with significantly less energy than those in which cholesterol predominated. Thermal imaging during laser treatment showed no significant rise in temperature in the bulk of the stone. Absorption spectroscopy of bile revealed a peak at 450 nm, coinciding with the known absorption characteristic of bilirubin. Bile strongly attenuated light at shorter wavelengths, even at dilutions as great as 1:20 and protected samples of biliary epithelium from laser damage except when the optical fibre was in direct contact. The pulsed dye laser may offer significant advantages over current methods of biliary stone fragmentation.

Bile↗
PubMed1989

A strategy for the investigation of immunodeficiency.

In any patient who suffers from frequent infections or from a clinical disorder caused by opportunistic organisms, the possibility of an underlying defect in immune defense should be considered. The purpose of this review is to outline a strategic approach towards screening for immunodeficiency in such patients. It should be apparent that the majority of serious immune deficiency states can be detected using a series of relatively simple and readily available investigations. The detection and further definition of other immunodeficiencies may require more sophisticated tests to be performed. The development of new biological tools now permits many of these disorders to be defined at the genetic and molecular level. Finally, early diagnosis of immunodeficiency is important, since it may permit the introduction of corrective measures which can reduce the morbidity and mortality of these disorders.

Humans↗
PubMed1989

Influence of housing conditions on the acquisition of intravenous heroin and cocaine self-administration in rats.

Group-housed and individually housed rats were tested for the acquisition of a lever-pressing response reinforced by intravenous heroin or cocaine; animals in each housing condition quickly learned to self-administer drug. In the first experiment the isolated rats learned to self-administer heroin earlier than the group-housed animals, but the two groups self-administered similar levels of heroin by the fifth week of testing. In the second experiment cocaine self-administration was learned with equal speed in the two groups, and similar levels of cocaine were self-administered by both groups throughout the experiment. These data indicate that while social isolation can influence levels of heroin self-administration, isolation is not a necessary condition for heroin or heroin or cocaine injections to be reinforcing.

Animals↗
PubMed1989

Defining parameters for peripheral laser angioplasty.

In vitro studies are reported using a Pulsed Dye laser at wavelengths of 440, 480, 504, 560 and 590 nm, to vaporise multiple samples of yellow, fibrous and calcified plaque. The threshold for crater production at 440 nm was 5 mJ/pulse and at 590 nm 65 mJ/pulse. Crater depth was significantly deeper at the short wavelengths (440, 480 and 504 nm) than at the longer (560 and 590 nm). Light microscopy confirmed the absence of thermal damage associated with continuous wave lasers. Electron microscopy revealed smooth-contoured craters and no disruption of subcellular elements at the crater margin. Samples of thrombus- and atheroma-occluded human femoral artery were successfully recanalised at the 480 nm wavelength with atraumatic spherical-tipped and modified spherical tipped optical fibres. The advantages of pulsed laser energy in peripheral vessel recanalisation are discussed.

Aorta↗
PubMed1989

Constitutive expression of c-myc oncogene confers hormone independence and enhanced growth-factor responsiveness on cells transformed by human papilloma virus type 16.

The effect of constitutive expression of the c-myc oncogene on the biological properties of cells transformed or immortalized by human papilloma virus type 16 (HPV16) was studied. Whereas transfection of HPV16 alone into primary baby mouse kidney (BMK) cells failed to generate any immortalized cell lines unless the tumor promoter phorbol 12-myristate 13-acetate was present, cotransfection of HPV16 with a plasmid that constitutively expresses murine c-myc (pSVc-myc-1) generated numerous rapidly growing colonies of cells. Cell lines transformed by HPV16 and pSVc-myc-1 did not require phorbol ester or steroid hormones for growth and were tumorigenic in syngeneic immunocompetent mice. Transfection of pSVc-myc-1 into established cell lines transformed by HPV16 and the v-fos oncogene increased the growth rate and saturation density of these lines severalfold, allowed growth in low-serum medium, and abolished the requirement of these cell lines for glucocorticoids or progestogens. Transfection of the EJ-ras oncogene into these lines did not significantly affect any of these properties.

Animals↗
PubMed1989

A cloned DNA probe for the detection of Mycobacterium paratuberculosis.

DNA extracted from Mycobacterium paratuberculosis, which had been isolated from a cow with clinical Johne's disease, was used to make a gene library in the Escherichia Coli expression vector phage lambda gt11. Plaque-lifts were made from the library onto nitrocellulose membranes. These were screened by differential hybridization using radiolabelled chromosomal DNA from M. paratuberculosis and Mycobacterium phlei. By this method six recombinants that hybridized to M. paratuberculosis but not to M. phlei were identified. Three of these, designated lambda gt-R3, lambda gt-R4 and lambda gt-RS, containing DNA inserts of 2.5,1.5 and 3.7 kilobases (kb), respectively, were chosen for further analysis of their insert specificities. Following restriction with the endonucleases EcoRI and BamHI, the digestion fragments from the three recombinants were transferred to nitrocellulose membranes and probed with radiolabelled DNA from M. paratuberculosis and M. phlei. As expected, M. paratuberculosis DNA hybridized to all the fragments. M. phlei DNA hybridized to both the fragments that were generated from lambda gt-R3, to the single fragment from lambda gt-R4 and to two of the three fragments generated from lambda gt-RS. The fragment with which M. phlei DNA failed to hybridize was 0.45 kb in length. Multiple copies of this fragment were made in the plasmid pGEM-2; the plasmid DNA was then harvested and radiolabelled. Designated PAM-1, the radiolabelled material hybridized to a 3.7 kb fragment of EcoRI-digested M. paratuberculosis and to 2.2 kb fragments of similarly digested M. avium serovars 2 and 3. PAM-1 did not hybridize to DNA from the other four mycobacterial species examined or from Nocardia asteroides. The restriction fragment length polymorphism thus demonstrated distinguishes M. paratuberculosis from M. avium serovars 2 and 3.

Journal Article↗
PubMed1989

Do electrode and lead design differences for permanent cardiac pacing translate into clinically demonstrable differences? (Comparison of sintered platinum and activated vitreous and porous carbon electrodes).

A randomized prospective study was undertaken to compare the electrical performances of three permanent, endocardial, tined pacing leads with different electrode designs--sintered platinum, vitreous carbon, and porous carbon. Ninety-nine patients received one of the leads (S80 31; 423S 32; S100 36). Acute R wave amplitude and ST elevation of the native endocardial electrogram, voltage threshold, impedance, and current flow at four pulse durations (0.25-1.0 msec) were measured. Voltage thresholds were measured noninvasively at each of four pulse durations at 2 days and 1, 3, and 6 months after implantation. No significant differences were found in sensing properties, or current flow at threshold at 0.5 msec pulse duration. The 423S lead had a significantly higher impedance at threshold and both a higher impedance and lower current flow at 5 V. No significant differences in threshold voltages were found between the three leads at any pulse duration, at any of the assessed times after implantation. Six-month thresholds for the S80, 423S, and S100 leads were 1.18 +/- 0.35, 1.17 +/- 0.29, and 1.06 +/- 0.38 V respectively at 0.5 msec pulse duration. Differences between 'high performance' pacing leads need to be of a greater order of magnitude before they can be exploited to give any real clinical advantage to patients.

Aged↗
PubMed1989

Direct immunofluorescence testing of skin biopsies--an under-utilised diagnostic aid.

Direct immunofluorescence testing of skin biopsies is a simple inexpensive and relatively non-invasive diagnostic procedure currently widely used in dermatological practice for the investigation and diagnosis of dermatological and immunological disorders. This paper reviews the value and applicability of the procedure in a variety of disease states. The sensitivity and specificity of the test to a spectrum of clinical conditions should encourage its more widespread use in general medical and rheumatology practice.

Biopsy↗
PubMed1989

Plasma lignocaine levels during transurethral prostatectomy.

It has been reported that transurethral absorption of lignocaine may cause systemic toxicity when associated with mucosal damage within the urethra. We measured the serum levels of lignocaine in 30 patients after the transurethral administration of 400 mg lignocaine gel just before transurethral prostatectomy. In 11 patients additional lignocaine was given as part of the anaesthetic induction (Group A). In 19 patients no additional lignocaine was given (Group B). Two patients in Group A and three patients in Group B also underwent Otis urethrotomy. The mean peak plasma lignocaine concentration as measured by sequential venous samples was 1424 ng/ml in Group A and 72 ng/ml in Group B. We conclude that 400 mg lignocaine gel applied endourethrally before transurethral resection of the prostate results in plasma concentrations well below the toxic levels.

Aged↗
PubMed1988

Analysis of human papillomavirus sequences in cell lines recently derived from cervical cancers.

The DNA and RNA from four cell lines recently derived from cervical carcinomas (HX151c, HX155c, HX156c, and HX160c) were analyzed for the presence of human Papillomavirus DNA. Each contained HPV-16 DNA in a multicopy integrated form of varying complexity. Each also expressed RNA transcripts of similar sizes to CaSki cell transcripts. The splice acceptor position within the E6 coding region of the cell line HX156c was identical to CaSki, SiHa, and HeLa cells as well as a cell line derived from mouse fibroblasts transformed with HPV-16 sequences in a retrovirus vector. Immunoprecipitation with an anti-HPV-16 E6 polyclonal antiserum demonstrated that HX160c cells contain the E6 polypeptide derived from unspliced transcripts.

Base Sequence↗