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Biomedical subjects

J Taylor

Publications and source records attributed to J Taylor.

At least 325 records · Page 18Linked to original sources
PubMed1995

Highly attenuated poxvirus vectors: NYVAC, ALVAC and TROVAC.

Three highly attenuated and efficacious poxvirus-based vectors, NYVAC, ALVAC and TROVAC, are available for targeted applications as recombinant vaccines in both human and veterinary medicine. The attenuated phenotype of the three vectors is consistent with safe use for vaccination purposes, for the vaccinee, for unvaccinated contacts, and for introduction into the environment. The precise deletion of virulence and host range genes in the NYVAC vector precludes reversion to the virulent phenotype by back mutation. Dissemination of recombinant vaccines based on the NYVAC, ALVAC and TROVAC vectors is highly diminished, because of the genetic engineering in NYVAC and the natural attenuated phenotype of ALVAC and TROVAC. Studies have demonstrated that these recombinant vectors are genetically and phenotypically stable after serial passage in vitro as well as in vivo. NYVAC, ALVAC and TROVAC vectors are the only three poxvirus-based vectors that are classified as BSL1 agents.

Animals↗
PubMed1994

The contraceptive practices of women seeking termination of pregnancy in an Auckland clinic.

AIM: The aim of the study was to assess the contraceptive knowledge and practices of women attending the abortion service at Epsom day unit, Green Lane Hospital. METHODS: Women attending the unit in December 1992 and January 1993 were asked to take part in the study. A questionnaire was administered to consenting women to assess demographic details and previous contraceptive education. If a contraceptive method was used the reason for failure was explored and if no method was used the reason for non use was explored. RESULTS: Sixty-one percent of women were using a contraceptive method in the month of conception. The condom was used by 48% and the pill by 42%. Eight percent of women had never used contraception and 30% were not using a method in the month of conception. Forty-three percent had a household income of less than $22,000 and financial barriers were the reason for non use in 32% of those not using a method. Of women who did not use contraception, only 11% used emergency contraception, whereas 78% of those surveyed said they knew about emergency contraception. Sixty-three percent of women said they had received enough contraceptive education to select and use a method effectively. Pacific Island women were least likely to have received adequate contraceptive education or to have been using a method of contraception. CONCLUSIONS: A number of technical problems were identified with condom use. These problems need to be emphasised by sexuality education programmes and contraceptive prescribers. Omitting pills, diarrhoea, vomiting and drug interactions were important causes of pill failure. The seven day rule needs more emphasis when teaching women how to take the pill and when antibiotics are prescribed. Costs were an important barrier to the use of contraception for a significant proportion of women. Section 99 approval should be utilised more readily and the provision of free contraception, especially to low income groups, needs to be urgently explored.

Abortion, Legal↗
PubMed1994

The extracellular matrix molecule janusin regulates neuronal morphology in a substrate- and culture time-dependent manner.

Janusin is an extracellular matrix glycoprotein with structural homology to tenascin. In search of extracellular matrix components which govern the differentiation of neurons in the central nervous system, we have investigated the influence of janusin on the differentiation of hippocampal neurons in vitro. Janusin coated onto nitrocellulose was a good substrate for attachment of cell bodies and neurite outgrowth after 21 h of culture. Most cells exhibited a polarized morphology with one long major neurite and one or two short minor neurites. When janusin was coated onto a polyornithine-conditioned plastic surface, it increased the polarity of neurons in that the length of major neurites was increased and the length and number of minor neurites were decreased when compared with the control polyornithine-conditioned plastic without janusin. As we have shown before for tenascin, laminin and fibronectin, polarization was preceded by an increase in the number and length of all neurites during the first hours after cell plating. This study therefore adds janusin to the increasing number of extracellular matrix glycoproteins which promote axonal but not dendritic growth.

Animals↗
PubMed1994

A randomized trial of acyclovir for 7 days or 21 days with and without prednisolone for treatment of acute herpes zoster.

BACKGROUND: Acyclovir given for 7 to 10 days is of proved benefit in acute herpes zoster, but studies of its effectiveness in preventing postherpetic neuralgia have had conflicting results. The role of corticosteroids in the treatment of herpes zoster is also controversial. METHODS: We conducted a double-blind, controlled trial in patients with acute herpes zoster to determine whether either 21 days of acyclovir therapy or the addition of prednisolone offered any improvement over 7 days of acyclovir therapy. Patients with a rash of less than 72 hours' duration were assigned to receive acyclovir (800 mg orally, five times daily) for 7 days with either prednisolone or placebo, or acyclovir for 21 days with either prednisolone or placebo. Prednisolone therapy was initiated at a dose of 40 mg per day and tapered over a three-week period. Patients were assessed frequently through day 28 and then monthly through month 6 to assess postherpetic neuralgia. RESULTS: Of 400 patients recruited, 349 completed the study. No significant differences were detected between the four groups in the progression of the rash (P > 0.1). With steroid therapy, a significantly higher proportion of the rash area had healed on days 7 and 14 (P = 0.02). Pain reduction was greater during the acute phase of disease in patients treated with steroids or 21 days of acyclovir (P < 0.01 and P = 0.02, respectively, on day 7; P < 0.01 for steroid therapy on day 14). However, on follow-up there were no significant differences between any of the groups in the time to a first or a complete cessation of pain. The steroid recipients reported more adverse events. CONCLUSIONS: In acute herpes zoster, treatment with acyclovir for 21 days or the addition of prednisolone to acyclovir therapy confers only slight benefits over standard 7-day treatment with acyclovir. Neither additional treatment reduces the frequency of postherpetic neuralgia.

Acute Disease↗
PubMed1994

Bier's block--the experience of Australian emergency departments.

OBJECTIVE: To describe the current use, effectiveness and safety of Bier's block within Australian emergency departments. DESIGN: A review of clinical practice based on an opinion survey of directors of emergency departments. PARTICIPANTS: Directors of 120 private and public hospital emergency departments. RESULTS: A response rate of 97% was achieved. Bier's block was used in 67% of Australian emergency departments. Emergency department medical staff performed the procedure in 83% of these hospitals. It was estimated that 7500 emergency department Bier's blocks were performed each year. Ninety-six per cent of respondents found Bier's block to produce adequate regional anaesthesia. Reported complications or adverse reactions were extremely rare. A wide variation in procedural approach was evident. CONCLUSIONS: Bier's block is a popular, reliable and relatively safe anaesthetic technique for use in emergency departments. Increased surveillance of local anaesthetic morbidity associated with the technique, as well as a standardisation of the procedure in the emergency department setting, are required.

Anesthesia, Conduction↗
PubMed1994

Comparison of EPI gradient-echo contrast changes in cat brain caused by respiratory challenges with direct simultaneous evaluation of cerebral oxygenation via a cranial window.

A gradient-echo echo planar imaging (EPI) sequence has been used to generate images of cat brain during respiratory challenges. Direct spectrophotometric measurements have been made simultaneously in order to correlate the changes in oxygen saturation as measured by spectrophotometry with the image intensity changes seen in the gradient-echo images. When blood volume remains approximately constant, as derived from the spectrophotometry data, good correlation is seen between calculated plots made of changes in the transverse relaxation rate, delta R2*, and the oxygen saturation as measured by spectrophotometry for much of the time course of the respiratory challenges of anoxia, apnea and hypercapnia. In some cases, the correlation is poorer during the recovery periods of the apnea and anoxia challenges. Those lower correlations can often be accounted for by changes in blood volume, which also affects the NMR relaxation rate. These results contribute to the understanding of the image intensity changes seen during functional brain imaging studies in humans.

Animals↗
PubMed1994

Central nervous system demyelinating diseases and increased release of cholesterol into the urinary system of rats.

The question of what happens to cholesterol in the adult central nervous system during its slow turnover has been addressed using rats with brain and spinal cord labeled with [4-14C]cholesterol upon intracerebral injection of labeled cholesterol into rats at 10-12 days of age. At six months after injection, 14C was found only in the brain and spinal cord and was slowly released via the rat's urine. When labeled rats were given demyelinating agents (triethyl tin chloride, hexachlorophene, sodium cyanide) and when experimental allergic encephalomyelitis was induced, a measurable increase in urinary 14C label above control levels was found. It was concluded that there is a direct relationship between the experimental demyelination induced and the increased release of cholesterol metabolites into urine. The study suggests that a clinical method could be developed to determine the rate of central nervous system demyelination by measuring the amount of urinary cholesterol metabolites.

Animals↗
PubMed1994

Comparison of influenza serological techniques by international collaborative study.

An international collaborative study was performed to investigate the reproducibility of influenza serological techniques. Participants in seven laboratories representing five countries measured antibody to A/Sichuan/2/87 (H3N2), A/Taiwan/1/86 (H1N1) and B/Beijing/1/87 influenza viruses in 11 human sera and three postinfection ferret sera. Two different serological techniques were used, haemagglutination inhibition (HI) and single-radial haemolysis (SRH) and, although each technique was reproducible within laboratories, variability between laboratories was higher for HI (maximum variability 32-fold; geometric coefficient of variation, GCV, 112%) than for SRH (maximum variability 3.8-fold; GCV 57%). The use of a standard serum allowed direct comparison of HI and SRH data and, for each technique, a standard serum improved inter-laboratory agreement. For influenza A viruses there was a correlation between HI and SRH antibodies (correlation coefficient approximately 0.9). An HI titre of 1:40 in human sera corresponded to an SRH titre of 19-33 mm2. The results of the study indicate that two sera would be expected to contain different antibody levels if their HI titres differed by > fourfold and SRH areas differed by > 50%. Both SRH and HI possessed equivalent sensitivity for measurement of antibody to influenza A viruses but SRH was more sensitive for detection of antibody to influenza B viruses. The study provided valuable information about standardization of antibody assays.

Animals↗
PubMed1994

RNA editing in the replication cycle of human hepatitis delta virus.

For some time it has been known that the RNA genome of human hepatitis delta virus (HDV) undergoes a specific RNA editing event. This review describes the editing phenomenon and its potential biological significance, and evaluates the data regarding the mechanism involved, including the possible relationship to other RNA editing phenomena.

Hepatitis Delta Virus↗
PubMed1994

Association of education with incidence of cognitive impairment in three established populations for epidemiologic studies of the elderly.

We analyzed the association of education, occupation, and sex with incidence of cognitive impairment using data from three communities in the Established Populations for Epidemiologic Studies of the Elderly (EPESE) projects (New Haven, East Boston, and Iowa). Participants were initially interviewed in 1981-1983, with follow-up 3 and 6 years later. Incident cognitive impairment was defined on the basis of either: (1) increase in the number of errors in Short Portable Mental Status Questionnaire (SPMSQ) (i.e. from a baseline level below the cutoff value to a score above the cutoff), or (2) inability to respond to interview questions at a follow-up contact (requiring a proxy informant), or (3) death with a recorded diagnosis of a dementing illness. In multiple logistic regression models, the major factors predicting the development of cognitive impairment were advanced age, any errors on baseline SPMSQ, 8 or fewer years of education, and occupation. Education and occupation remained significant predictors after controlling for age, site, sex, stroke, and baseline SPMSQ score.

Aged↗
PubMed1994

Effects of fasting on fatty acid kinetics and on the cardiovascular, thermogenic and metabolic responses to the glucose clamp.

1. The effects of fasting for 12, 36 and 72 h were examined in 19 normal subjects. Each subject was studied before and during a euglycaemic (4 mmol/l) hyperinsulinaemic (100 m-units min-1 m-2) clamp. Measurements were made of palmitate turnover and oxidation, glucose disposal, thermogenesis, intermediary metabolites and cardiovascular variables. 2. Basal respiratory exchange ratio fell from 0.78 +/- 0.01 to 0.75 +/- 0.01 to 0.72 +/- 0.01 with fasting (P < 0.001). In response to the clamp it rose to 0.91 +/- 0.02, 0.83 +/- 0.01 and 0.77 +/- 0.01 after 12, 36 and 72h respectively. Metabolic rate rose during the clamp by 0.41 +/- 0.06, 0.11 +/- 0.03 and 0.14 +/- 0.04 kJ/min respectively (P < 0.001 for 36- and 72-h values versus that at 12h). 3. Fasting reduced total insulin-mediated glucose disposal rates from 42.6 +/- 2.5, to 31.0 +/- 1.8 to 21.3 +/- 1.5 mumol min-1 kg-1 body weight after 12, 36 and 72h respectively (P < 0.001). Glucose oxidation fell from 16.9 +/- 1.1 to 8.7 +/- 1.7 to 0.2 +/- 1.3 mumol min-1 kg-1 body weight over the same period (P < 0.001). Non-oxidative glucose disposal rates did not change significantly. 4. Basal plasma palmitate turnover increased with duration of fasting, being 1.16 +/- 0.08, 1.72 +/- 0.17 and 2.30 +/- 0.35 mumol min-1 kg-1 body weight. In response to the clamp, palmitate turnover fell to 0.42 +/- 0.05, 0.69 +/- 0.08 and 1.28 +/- 0.45 mumol min-1 kg-1 body weight. Plasma palmitate oxidation was 0.58 +/- 0.04, 0.75 +/- 0.06 and 1.13 +/- 0.11 mumol min-1 kg-1 body weight basally, and fell to 0.16 +/- 0.02, 0.28 +/- 0.04 and 0.43 +/- 0.13 mumol min-1 kg-1 body weight by the end of the clamp. The proportion of total lipid oxidation represented by plasma non-essential fatty acid oxidation was not affected by fasting, but fell in response to the clamp. 5. Fasting caused a progressive resistance to the effects of insulin and glucose on oxidative glucose disposal and on forearm glucose uptake. Insulin-mediated glucose storage was unaffected by fasting, but the apparent cost of this storage was reduced by fasting.

Adult↗
PubMed1994

Southern blot analysis of lymphoproliferative disorders: use and limitations in routine surgical pathology.

Antigen receptor gene rearrangement studies are a sensitive means of determining lineage and clonality in lymphoproliferative disorders (LPDs) which remain difficult to classify after assessment of morphology and immunohistochemistry (IHC). This study investigates the utility of genotyping LPDs in a surgical pathology laboratory servicing a large teaching hospital. Ninety-eight specimens with detailed frozen (FS) and/or paraffin section IHC were studied, including 65 B-cell lymphomas, 14 T-cell lymphomas, 2 biopsies of T-zone dysplasia, one unclassifiable lymphoma, 8 Hodgkin's disease (HD) and 8 reactive nodes. Southern blotting (SB) was performed on tumor and control DNA cleaved with restriction enzymes EcoR1, Hind III and BamH1, using radiolabelled probes for the immunoglobulin heavy chain joining region, constant regions of kappa and lambda light chains, and the constant region of the T-cell receptor beta chain. All reactive nodes and those harbouring HD and DNA in the germline configuration, apart from JH rearrangement in one case each of HD and florid reactive hyperplasia. Of the non-Hodgkin's lymphomas (NHL), 17% did not reveal clonal rearrangements (11% B-NHL; 44% T-NHL). Most of the negative results could be explained by sampling error in partially involved nodes, highly polymorphous infiltrates where the neoplastic population may have been below the 1% threshold detectable by SB, and instances of anaplastic large cell lymphoma. After accounting for these cases, a 5% negative rate of genoclonality remained (3% B-NHL; 13% T-NHL). In the majority of NHL (95%), the diagnosis could be established on the basis of morphology and/or IHC alone.(ABSTRACT TRUNCATED AT 250 WORDS)

Blotting, Southern↗
PubMed1994

Input impedance of radiocephalic arteriovenous fistulae for haemodialysis access: its value in predicting early failure.

This study is concerned with an assessment of the quality of the blood vessels used in the construction of radiocephalic arteriovenous fistulae for haemodialysis vascular access in 20 patients. Following non-invasive preoperative assessment of the cephalic vein by means of a colour Doppler scanner, input impedance was determined intraoperatively from blood flow and blood pressure measured about 2 cm downstream of the anastomosis. The patients were re-assessed 1 day and 2, 4, 6 and 12 weeks after surgery, and the diameter and the flow through the fistulae, the location of major branches, and the presence and severity of stenoses in the cephalic veins were determined non-invasively. Five fistulae failed within the 12 weeks period following surgery, mainly due to thrombosis. In a further 3 patients, the fistulae were patent but did not achieve an adequately high blood flow and dilate sufficiently for haemodialysis and were therefore considered to be essentially failed. The impedance moduli from 0 to 10 Hz as well as the average impedance modulus of successful fistulae were significantly lower than those of fistulae that subsequently failed. An attempt was made to locate the presence of reflection sites (i.e. stenoses and branches) from the minima in the impedance modulus spectra. Their locations were compared with those of the reflection sites detected by ultrasound 2 weeks after surgery. However, not all reflection sites detected 2 weeks after surgery were located by the impedance method. It is recommended that both preoperative examination and intraoperative haemodynamic measurements be made to improve the accuracy of the assessment.

Arteriovenous Shunt, Surgical↗
PubMed1994

Distended iliopsoas bursa: case reports and anatomical dissection.

Distension of the iliopsoas bursa is usually seen in association with underlying hip joint disease. The computed tomography (CT) appearance is characteristic and allows a diagnosis to be readily made. Computed tomography will also facilitate needle placement for aspiration of bursa contents and the injection of water-soluble contrast media for CT bursography. Three cases of iliopsoas bursa enlargement of varying underlying aetiology are presented. The dissection of seven cadavers demonstrated the anatomy of the normal bursa and highlighted its important role in the normal functioning of the iliopsoas muscle.

Aged↗
PubMed1994

Skin elicitation threshold of ethylbutyl thiourea and mercaptobenzothiazole with relative leaching from sensitizing products.

We studied 3 contact sensitizers present in rubber products, ethylbutyl thiourea (EBT), 2-mercaptobenzothiazole (MBT) and 2,2-dithio-bis-benzothiazole (MBTS), to relate the amount of sensitizer eliciting allergic contact dermatitis to the quantity leaching from a product into various biological fluids: normal saline, human plasma and 3 synthetic sweat solutions of pH 5.5 to 7.5. To determine the amount of sensitizer remaining after leaching, Soxhlet extraction with acetonitrile was subsequently performed. High-performance liquid chromatography was used for chemical analysis. 12 MBT-sensitive patients were patch tested with serial dilutions of MBT and MBTS in petrolatum. A Latin Square design was used in statistical analysis of variance of the patch test results. Large amounts of thioureas leached from 2 rubber articles eliciting thiourea dermatitis, the literature suggesting that these would have been well above the elicitation threshold. Leaching of MBTS was relatively greater than MBT into most media, whereas MBT was a more potent elicitor than MBTS at equivalent concentrations. The lowest eliciting concentration of MBT in 1 subject was 0.01%. Such information should prove helpful to manufacturers in designed products that do not release allergens sufficiently to cause reactions in consumers.

Adolescent↗