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Biomedical subjects

G Jones

Publications and source records attributed to G Jones.

At least 397 records · Page 22Linked to original sources
PubMed1990

Evolving myocardial infarction during percutaneous transluminal coronary angioplasty: the use of portable percutaneous cardiopulmonary support.

Percutaneous transluminal coronary angioplasty (PTCA) has become an invaluable tool in the treatment of coronary artery disease. However, it is not without risks. For the PTCA patient who develops signs and symptoms of an evolving myocardial infarction, the time delay involved in the transportation of the patient from the angiography suite to the operating room becomes important. Institution of cardiopulmonary bypass in the angiography suite has enabled the successful transport of the patient to the operating room in a hemodynamically stable condition. We now present two case reports of patients treated with emergent percutaneous cardiopulmonary bypass following the development of myocardial infarction during PTCA.

Angioplasty, Balloon, Coronary↗
PubMed1990

Investigation of interference by nonsteroidal anti-inflammatory drugs in urine tests for abused drugs.

Anecdotal and uncontrolled studies have suggested that nonsteroidal anti-inflammatory drugs produce false-positive results in immunoassay urine tests for some drugs of abuse. This study was performed in 60 volunteers who took ibuprofen as either a single 400-mg dose, or 200 mg three times a day, or 400 mg three times a day, and in 42 patients taking ibuprofen, naproxyn, or fenoprofen in therapeutic regimens for more than 30 days. Of the 510 urines collected from 102 individuals during these dosage regimens, two gave false-positive tests for cannabinoid by enzyme-mediated immunoassay (EMIA), one after 1200 mg of ibuprofen in three divided doses for one day and one in a patient taking naproxyn on a chronic basis; none was falsely positive for benzodiazepines. Two urines were false-positive for barbiturates by fluorescence polarization immunoassay (FPIA), one in a patient taking ibuprofen and one in a patient taking naproxyn. These data, collected prospectively, demonstrate the small likelihood of a false-positive immunoassay test result for cannabinoids, benzodiazepines, or barbiturates after the acute or chronic ingestion of ibuprofen, or after the chronic ingestion of naproxyn or fenoprofen.

Adult↗
PubMed1989

Coordinate induction of electrophoretic variants of juvenile hormone esterase.

Major and minor electrophoretic variants of juvenile hormone esterase (JHE) were found in the hemolymph of last instar larvae of Trichoplusia ni, both before and after metamorphic commitment. The average ratios of activity of the two major forms were similar during both last stadium peaks in activity. Immunological analysis showed that the hemolymph concentration of JHE during this stadium paralleled the level of enzymatic activity, and no putative higher molecular weight, inactive forms were detected. Immunological analysis provided the first evidence of relatedness of major and minor forms. After hormonal stimulation, the concentration of the two major forms increased concomitantly and by a similar proportion, suggesting that charge variation, at least for these two major forms, is not a point of hormonal or developmental regulation of JHE.

Animals↗
PubMed1989

Target cell metabolism of 1,25-dihydroxyvitamin D3 to calcitroic acid. Evidence for a pathway in kidney and bone involving 24-oxidation.

1,25-dihydroxyvitamin D3 is converted to calcitroic acid before being excreted in the bile. Biosynthesis of calcitroic acid has been demonstrated in two target cells of vitamin D, in the kidney and the osteoblastic cell line UMR-106. Calcitroic acid was identified by combinations of h.p.l.c., u.v. spectroscopy and mass spectrometry. Evidence is presented that calcitroate is derived from the 24-oxidation pathway, possibly through the intermediate 24,25,26,27-tetranor-1,23-dihydroxyvitamin D3. The 24-oxidation pathway to calcitroic acid in bone cells is stimulated by 1,25-dihydroxyvitamin D3. The pathway in both bone cells and perfused kidney operates at physiological concentrations of substrate and appears to be capable of rapid clearance of the hormone.

Animals↗
PubMed1989

Immune response to a synthetic peptide corresponding to an epitope of a parasitophorous vacuole membrane antigen from Plasmodium falciparum.

The parasitophorous vacuole membrane antigen QF 116 from Plasmodium falciparum contains a defined epitope, DNNLVSGP, proximal to the carboxyl-terminus which binds to the inhibitory monoclonal antibody 8E7/55. A synthetic peptide containing this epitope was constructed and coupled to diphtheria toxoid as carrier. Mice and rabbits were inoculated with this conjugate using CFA, SAF-1, or aluminum phosphate as adjuvants. The peptide conjugate was highly immunogenic in both animal species, giving rise to polyclonal antibodies with a similar epitope specificity as the original mAb. Antibody titers were dependent on the route of immunization. Rabbit antibodies produced in sufficient quantity for biologic assays inhibited parasite growth in vitro. This synthetic peptide thus shows promise as an immunogen for use in synthetic vaccine design.

Amino Acid Sequence↗
PubMed1989

Aspergillosis of prostate.

We report a rare case of primary prostatic aspergillosis in a well-controlled diabetic man who presented to our clinic in acute urinary retention. His management and the literature are reviewed.

Aged↗
PubMed1989

Electroacoustic fusion of millilitre volumes of cells in physiological medium.

A technique is described in which erythrocytes suspended in 1.1 ml of 145 mM NaCl, have been fused by electrofusion. The cells in suspension were brought into close contact by setting up a 3 MHz ultrasonic standing wave in a cylindrical cell container. The aluminium foil base of the container served both to transmit ultrasound and as an electrode for electrofusion. The electric pulse was generated by a capacitor discharge system. The electric field strength required to fuse cells increased as the ionic strength of the cell suspending phase increased. Cells in physiological saline fused at an electric field strength of 7.3 kV/cm with a 50 microseconds pulse.

Cell Fusion↗
PubMed1989

The effect of portal diversion upon function of the reticuloendothelial system and upon plasma fibronectin levels.

A previous publication suggested that for 9 weeks after portal diversion in dogs, there were no changes in reticuloendothelial function assessed by measurement of t1/2 or phagocytic index of reticuloendothelial test lipid emulsion. The present study was conducted in rats over 18 weeks. It was observed that the phagocytic index decreased and the t1/2 lengthened at 18 weeks after either portacaval shunt or portacaval transposition and that plasma levels of fibronectin were elevated four- or five-fold after either form of diversion, whilst only being elevated two-fold after sham operation. There was an increase in portacaval shunt rats in liver tissue distribution of administered lipid emulsion when tested between 6 and 12 weeks post-operatively which then returned towards normal. The activity in portacaval transposition and sham-operated rats was unaltered. These studies suggest that the delay in clearance of administered particles in portacaval shunt and portacaval transposition rats is related to the portal diversion rather than to altered blood flow and thus the finding is of relevance in patients with cirrhosis who also have significant portacaval shunting.

Animals↗
PubMed1989

Multiple carpo-metacarpal dislocations.

Ten patients with closed multiple carpo-metacarpal dislocations have been reviewed. Closed manipulation was found to be successful if performed within two days of the injury. Plaster cast immobilisation supplemented by percutaneous Kirschner wire fixation is recommended to maintain the reduction, due to the unstable nature of the dislocation. Early appropriate treatment of these injuries carries a good prognosis.

Bone Wires↗
PubMed1989

The effect of chlamydial infection on the initiation of premature labour: serial measurements of intrauterine prostaglandin E2 in amniotic fluid, allantoic fluid and utero-ovarian vein, using catheterised sheep experimentally infected with an ovine abortion strain of Chlamydia psittaci.

The initiation of premature labour by an ovine abortion strain of Chlamydia psittaci was studied in relation to Prostaglandin E2 (PGE2), which plays a major role in parturition. The local intrauterine concentration of PGE2 was monitored after experimental infection with C. psittaci, during late gestation, using a catheterised sheep model. Indwelling catheters were implanted into the amniotic and allantoic cavities of six control sheep, and into six sheep infected with an ovine abortion of C. psittaci. The release of PGE2 into the utero-ovarian vein of these sheep was also monitored. Infection with C. psittaci was associated with a premature rise in PGE2 in the amniotic fluid between days 122 and 135 of gestation (P less than 0.01). A premature increase in PGE2 was defected between days 127 and 136 of gestation (P less than 0.05) in the allantoic fluid of sheep infected with C. psittaci, but not in the control uninfected sheep. Chlamydial infection significantly decreased the secretion of PGE2 into the utero-ovarian vein. The mean concentration of PGE2 in the utero-ovarian vein of infected sheep was 68.8 +/- 5.2% of the PGE2 concentration of control sheep between days 122 to 141 of gestation (P less than 0.01). The release of PGE2 into the utero-ovarian vein increased between days 126 to 136 of gestation in infected and control sheep (P less than 0.01). The results from the catheterised sheep model indicated that C. psittaci infection is associated with a local intrauterine release of PGE2. The magnitude of this release was similar to the PGE2 release in control sheep prior to parturition.(ABSTRACT TRUNCATED AT 250 WORDS)

Allantoin↗
PubMed1989

Use of zidovudine for drug misusers infected with human immunodeficiency virus.

The use of zidovudine in drug misusers, especially current drug misusers, has not been extensively studied. Since periods of abstinence may be interspersed with drug misuse, it is necessary to establish the safety of zidovudine in injection drug misuse-related human immunodeficiency virus (HIV) infection under a variety of conditions. HIV serology became available in October 1985 and we have now examined medically 289 HIV seropositive patients, 85% of whom acquired their infection via injection drug misuse. Since March 1987 we have treated 40 individuals with zidovudine, 25 of whom were former or current injection drug misusers and one who was a heterosexual contact of a drug misuser. Eighteen patients were taking various types of opiates. Six of this latter group injected either occasionally or regularly whilst taking zidovudine. There were no adverse clinical events associated with zidovudine treatment and continued opiate drug misuse whether by mouth or by injection. Although defaults from clinic visits were a problem, these defaults were not associated with any particular form of drug misuse. Compliance with zidovudine therapy as judged by change in the mean corpuscular volume was no different for the various risk groups. In our experience it is possible to treat safely current and former drug misusers with zidovudine.

Acquired Immunodeficiency Syndrome↗
PubMed1989

Comparison of bupivacaine and bupivacaine with fentanyl in continuous extradural analgesia during labour.

In a randomized, double-blind study of 39 mothers in labour, we have compared a loading dose of 0.5% bupivacaine 6.0 ml and fentanyl 100 micrograms given extradurally, followed by an infusion of 0.08% bupivacaine 15 ml h-1 plus fentanyl 37.5 micrograms h-1, with a loading dose of 0.5% bupivacaine 6.0 ml and saline 2.0 ml, followed by an extradural infusion of 0.08% bupivacaine alone, per hour. Analgesic levels were more consistent and sustained in mothers who received fentanyl in addition to bupivacaine, and the duration from the time of the loading dose to the first top-up was extended considerably in this group. The only significant side effect was a high incidence of mild pruritus in the fentanyl group. The addition of fentanyl to the extradural loading dose and subsequent infusion of local anaesthetic is a satisfactory alternative to giving higher doses of local anaesthetic alone.

Adult↗
PubMed1989

Growth failure prediction in Chile.

The purpose of this investigation was to develop screening instruments for the prediction of infants' growth failure. Biological and social variables of subjects attending public clinics in Santiago, Chile, were prospectively collected and screened as possible risk factors of being underweight/age at the end of the first year of life using three methodologies. Methodologies used were: simple relative risk, logistic regression, and classification and regression trees. As judged by sensitivity and specificity properties, the screening instrument developed by the latter methodology is much better than the other two.

Chile↗