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Biomedical subjects

J Taylor

Publications and source records attributed to J Taylor.

At least 271 records · Page 15Linked to original sources

In vivo footprinting analysis of the hepatic control region of the human apolipoprotein E/C-I/C-IV/C-II gene locus.

Expression of both the apolipoprotein (apo)E and apoC-I genes in the liver is specified by a 319-nucleotide hepatic control region (HCR-1) that is located 15 kilobase pairs downstream of the apoE gene and 5 kilobase pairs downstream of the apoC-I gene. In vivo footprint analysis of HCR-1 in intact nuclei revealed several liver-specific protein-binding sites that were not detectable by in vitro methods. In addition to three previously identified in vitro footprints, four in vivo footprints were identified in a region of HCR-1 that is required for directing gene expression to hepatocytes. Prominent liver-specific DNase I-hypersensitive sites were associated with these footprints. Liver-specific nuclear protein binding to these sites was confirmed by oligonucleotide gel-retention assays. The in vivo analysis also identified a cluster of nuclear protein-binding sites in the Alu family repeat segment adjacent to the domain required for liver expression. Micrococcal nuclease digestion indicated the presence of a nucleosome in the central domain of HCR-1 in liver chromatin that was in phase with the nucleosome location in tissues that did not express the transgene. These results suggest that HCR-1 functions in a highly structured chromatin environment requiring a complex interaction of liver-enriched transcription factors.

Apolipoprotein C-I↗

Seroprevalence of herpes simplex virus type 2 antibodies in New Zealand sexual health clinic patients.

AIM: To determine the prevalence of HSV-2 antibodies in STD clinic patients in Auckland and Christchurch between August 1991 and August 1992. METHODS: An unlinked anonymous HIV seroprevalence study was conducted in STD clinic patients in Auckland and Christchurch between August 1991 and August 1992. This cross-sectional seroprevalence study using stored sera and data from the HIV seroprevalence study, was conducted to determine the prevalence of antibody to herpes simplex virus type 2 (HSV-2). A random sample of 300 sera were analysed, using a type specific indirect enzyme-linked immunoassay (ELISA) to HSV glycoprotein G2 (gG-2) with Western blot confirmation of equivocal results. RESULTS: The seroprevalence was 25.7%. The seroprevalence increased up to age 50 years, but no significant differences were found for gender, or for European, Maori, or Pacific Island ethnic groups. The seroprevalence was significantly higher in sera obtained from patients attending the South Auckland STD clinic, than in that from Auckland central, west Auckland, or Christchurch clinics. CONCLUSIONS: We can conclude that infection with HSV-2 is common in STD clinic patients in New Zealand, and lies within the seroprevalence range of other similar studies from other countries.

Adolescent↗

Distinct effects of recombinant tenascin-C domains on neuronal cell adhesion, growth cone guidance, and neuronal polarity.

Using a set of recombinantly expressed proteins, distinct domains of the mouse extracellular matrix glycoprotein tenascin-C, hereafter called tenascin, have been identified to confer adhesion, anti-adhesion, and changes in morphology of neuronal cells. In short-term adhesion assays (1 hr), cerebellar and hippocampal neurons adhered to several domains, encompassing the fibronectin type III-like (FN III) repeats 1-2 and 6-8, as well as to the alternatively spliced FN III repeats and to tenascin itself. Although no short-term adhesion to the EGF repeats containing fragment could be detected under the conditions used, it was anti-adhesive for neuronal cell bodies and repellent for growth cone advance and neuritogenesis. FN III repeats 3-5 were repellent only for growth cones but not for neuronal cell bodies. Neurite outgrowth promoting activities at early stages and induction of a polarized neuronal morphology at later stages of differentiation were associated with the EGF repeats and the FN III repeats 6-8. These observations suggest differential effects of particular domains of the tenascin molecule on distinct cellular compartments, i.e., cell body, axon and dendrite, and existence of multiple neuronal receptors with distinct intracellular signaling features.

Animals↗

Fluorescent multiplex microsatellites used to define haplotypes associated with 75 CFTR mutations from the UK on 437 CF chromosomes.

The cystic fibrosis (CF) transmembrane conductance regulator (CFTR) gene contains three highly informative microsatellites: IVS8CA, IVS17bTA, and IVS17bCA. Their analysis improves prenatal/ carrier diagnosis and generates haplotypes from CF chromosomes that are strongly associated with specific mutations. Microsatellite haplotypes were defined for 75 CFTR mutations carried on 437 CF chromosomes (220 for delta F508, 217 for other mutations) from Northern Ireland and three English regions: the North-West, East Anglia, and the South. Fluorescently labelled microsatellites were amplified in a triplex PCR reaction and typed using an ABI 373A fluorescent fragment analyser. These mutations cover all the common and most of the rare CF defects found in the UK, and their corresponding haplotypes and geographic region are tabulated here. Ancient mutations, delta F508, G542X, N1303K, were associated with several related haplotypes due to slippage during replication, whereas other common mutations were associated with the one respective haplotype (e.g., G551D and R560T with 16-7-17, R117H with 16-30-13, 621 + 1G > T with 21-31-13, 3659delC with 16-35-13). This simple, fast, and automated method for fluorescent typing of these haplotypes will help to direct mutation screening for uncharacterised CF chromosomes.

Chromosomes, Human↗

Population mobility and indigenous peoples: the view from Australia.

"This paper describes an emerging field of demographic enquiry focused on the population mobility of indigenous minorities in Australasia and North America. Political, scientific and policy rationales for research on the spatial dynamics of such groups are advanced as a prelude to a review of the Australian literature. This review is structured around four complementary perspectives on mobility: the propensity to move; spatial redistribution; flows and networks; and migration careers. Comparison of the relative strengths of mobility research on the indigenous and non-indigenous populations against these four perspectives assists in identifying outstanding research needs and priorities. Commonalities in the patterns and processes of indigenous mobility in Australia, New Zealand, Canada and the U.S. suggest the value of more detailed cross-national comparisons, and also provide a basis for contemplating an indigenous variant of Zelinsky's hypothesised mobility transition."

Americas↗

Reproductive functions illustrating direct and indirect effects of genes on behavior.

Effects of gene products on reproductive behavior which are relatively direct include those of the estrogen receptor and progesterone receptor. For example, work with estrogen receptor-deficient (ERKO) female mice has extended previous evidence contributing to the neurochemical analysis of lordosis behavior. On the other hand, sex differences in behavior present a classic example of indirect effects of genes on behavior. Work with ERKO male mice shows the necessity of ER gene expression for normal masculinization of the brain. In particular, behavioral assay results distinguish apparent motivational performance of ERKO males from male mating reflexes: the former is similar to that of wild-type males in important respects, while the latter are deficient in ERKO males. The present paper first reviews a small number of clear genetic contributions to reproductive behaviors, and then reports one experiment pertinent to the interpretation of the behavioral status of ERKO male mice.

Animals↗

Ethnographic perspectives on the enumertion of aboriginal people in remote Australia.

"This paper compares population counts and age distributions from the last two Australian Bureau of Statistics (ABS) enumerations of the Aboriginal population of Aurukun, Cape York Peninsula, with the results of detailed ethnographic surveys of the same population at similar points in time. This reveals substantially lower numbers for the ABS counts, particularly of young adults and children. Reasons for this discrepancy are sought in the ethnographic realities of remote indigenous communities and an alternative methodology for Aboriginal enumeration in remote regions is suggested."

Age Distribution↗

Effect of transcranial magnetic stimulation over the cerebellum on the excitability of human motor cortex.

There have been conflicting reports over whether it is possible to stimulate the human cerebellum through the intact scalp using transcranial magnetic stimulation. Here we attempt to clarify the situation in normal subjects by comparing the various methods which have been used. EMG responses evoked by magnetic stimulation over the motor cortex could be suppressed by a prior magnetic stimulus over the cerebellum but the onset latency of the effect varied according to the type of magnetic coil used. Inhibition began at a latency which ranged from 5 to 9 msec in different subjects if conditioning stimuli were given through a flat figure-of-eight coil held horizontally over the basal occiput. The effect lasted a further 6-10 msec. With a larger double cone coil, held vertically over the basal occiput, inhibition began earlier and at a more constant latency of 5 msec. It lasted only 3 msec. Stimulation of the C6/7 nerve roots in the brachial plexus with either an electrical or magnetic stimulus also could suppress EMG responses evoked by cortical stimulation. This began at a conditioning-test interval of 7 or 8 msec and lasted for some 5 msec. We suggest that two types of motor cortical suppression may be elicited from stimulation over the posterior neck/skull: a cerebellar effect starting at 5 msec, and a peripheral nerve effect starting later at 7/8 msec. Stimulation with a horizontal large figure-of-eight coil may produce a mixture of effects because the lower wing of the coil overlaps the posterior neck and can activate peripheral nerve fibres in the brachial plexus.

Adult↗

Human safety and immunogenicity of a canarypox-rabies glycoprotein recombinant vaccine: an alternative poxvirus vector system.

Avian poxvirus recombinants undergo abortive replication in nonavian cells, yet can achieve expression of extrinsic gene products. Canarypox-vectored vaccines have been innocuous and immunogenic in several mammalian species. ALVAC-RG, a canarypox recombinant expressing the rabies glycoprotein gene, was inoculated intramuscularly into adult volunteers on days 0, 28, and 180. Sequential cohorts received 10(3.5), 10(4.5), and 10(5.5) 50% tissue culture infective doses (TCID50); additional volunteers received the standard human diploid cell rabies vaccine (HDCV) on the same schedule. Reactogenicity of ALVAC-RG was minimal. The lowest dose of ALVAC-RG induced little antibody to rabies virus by ELISA or rapid fluorescent focus inhibition test (RFFIT), but 10(4.5) and 10(5.5) TCID50 doses elicited significant responses in both assays. All recipients of 10(4.5) and 10(5.5) TCID50 of ALVAC-RG attained RFFIT values above the presumed protective level. Canarypox-specific immune responses did not inhibit boosting of rabies-specific antibodies by the day 180 dose of ALVAC-RG. T cell proliferation in response to inactivated rabies virus in vitro was similar in HDCV and ALVAC-RG recipients after the first and second doses, although HDCV yielded superior results after the third dose. ALVAC-RG was safe in humans, induced functional antibody to rabies glycoprotein, elicited cellular responses to rabies virus, and could be used successfully for booster dosing at a 6 month interval.

Adolescent↗

The incidence and relevance of bone sclerosis in orbital pseudotumour.

We reviewed the CT studies of 176 patients with biopsy-proven inflammatory pseudotumour of the orbit, in an attempt to establish the incidence of bone sclerosis in this condition. We found 20 patients (11.5%) to show definite bone sclerosis and/or hyperostosis, and in a further 10 (6%) there was probable sclerosis, giving a total of 30 patients (17%) with some evidence of bony change. Bone-window films were available for a minority of patients, and the frequency of sclerosis was therefore probably underestimated. This feature, which presumably represents a low-grade, chronic sterile osteitis, has not previously been emphasised.

Humans↗

Abnormalities in alpha-, beta- and gamma-sarcoglycan in patients with limb-girdle muscular dystrophy.

We have identified 12 cases from a group of 45 patients with early onset limb-girdle muscular dystrophy (LGMD), who have a deficiency of the 50 kDa dystrophin-associated glycoprotein, alpha-sarcoglycan. An additional male sibling of one case was also studied clinically. All 12 patients showed a concomitant, but variable, deficiency of alpha-, beta- and gamma-sarcoglycan. None of our patients had a defect in only one component of the sarcoglycan complex. Molecular analysis confirmed that a total absence of one sarcoglycan, associated with reduced expression of the other two, indicates a primary defect. Immunocytochemistry is thus useful for directing molecular studies. Morphological features not usually observed in Xp21 dystrophies were peripheral accumulations of mitochondria, discrete core-like areas, and nemaline rods in one case. Clinical severity and progression was variable between and within families but early loss of ambulation, at or before the age of 12 years, was associated with a total absence of gamma-sarcoglycan. Common clinical features were calf hypertrophy, contractures of the tendo achilles, lumbar lordosis, winging of the scapulae, weak hamstrings and weak neck muscles. All cases had grossly elevated serum creatine kinase. In contrast to patients with Duchenne muscular dystrophy (DMD), our patients with sarcoglycan deficiencies had normal early motor milestones, normal intellect, and good respiratory and cardiac function. Our data confirm that the sarcoglycan complex acts as a unit and that morphological and clinical features can distinguish patients with defects in the sarcoglycans from those with Xp21 dystrophy. In our group of patients prognosis is better than in DMD, but clinical variability makes this difficult to predict in isolated cases.

Age of Onset↗

Laparoscopic Burch Colposuspension for Urinary Stress Incontinence

To date we have performed 58 laparoscopic Burch colposuspensions, 28 by the extraperitoneal route and 30 with the transperitoneal approach. The 58 women (mean age 48.9 yrs, mean weight 71.1 kg) all underwent urodynamic studies. Sixteen had mixed findings of stress and urge incontinence. The operative technique involved dissection into the space of Retzius. Laparoscopic suturing techniques were employed using either 0 Dacron or polyester between the paravaginal fascia and the iliopectineal ligaments. Satisfactory elevation of the bladder neck was obtained. Associated procedures were predominantly laparoscopic hysterectomy. Comparison of the two approaches showed equivalent blood loss, return to normal activity, operating times, and duration of postoperative catheterization. Hospitalization was significantly longer in the extraperitoneal group. Significant complications were cystotomy in four women and conversion to laparotomy in four. Duration of follow-up was equivalent in both groups, ranging from 6 to 33 months. Success rates were also equivalent, with only one failure in total, occurring in the transperitoneal group. Laparoscopic Burch colposuspension is a safe, effective procedure and should replace the conventional approach by laparotomy.

Journal Article↗

Factors associated with early failure of arteriovenous fistulae for haemodialysis access.

The radiocephalic arteriovenous fistula remains the method of choice for haemodialysis access. In order to assess their suitability for fistula formation, the radial arteries and cephalic veins were examined preoperatively by ultrasound colour flow scanner in conjunction with a pulse-generated run-off system. Intraoperative blood flow was measured after construction of the fistulae. Post-operative follow-up was performed at various intervals to monitor the development of the fistulae. Radial artery and cephalic vein diameter less than 1.6 mm was associated with early fistula failure. The intraoperative fistula blood flow did not correlate with the outcome of the operation probably due to vessel spasm from manipulation. However, blood flow velocities measured non-invasively 1 day after the operation were significantly lower in fistulae that failed early compared with those that were adequate for haemodialysis. Most of the increase in fistula diameter and blood flow occur within the first 2 weeks of surgery.

Arm↗