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Biomedical subjects

J Taylor

Publications and source records attributed to J Taylor.

At least 361 records · Page 20Linked to original sources
PubMed1994

Ulnar peripheral nerve stimulation by train-of-four technique in adult nonmedicated patients.

BACKGROUND: Peripheral nerve stimulation is necessary to quantify the level of neuromuscular blockade and prevent prolonged paralysis related to drug accumulation. Some nurses and physicians are hesitant to administer nerve stimulation because of concerns about inflicting pain on the patient. OBJECTIVE: To describe the feeling associated with train-of-four ulnar nerve stimulation, and to quantify discomfort, monitor heart rate response, and define the amount of current necessary to stimulate thumb adduction. METHODS: Healthy, nonmedicated volunteer subjects (N = 39) were asked to describe train-of-four ulnar nerve monitoring at 3 current strengths. Heart rate was monitored throughout the testing procedure. The milliamperes delivered at each current strength and the occurrence of thumb adduction were recorded. RESULTS: Subjects described nerve stimulation generally as an unusual prickly sensation. On a discomfort scale of 1 to 10, the mean discomfort score when stimulated with the current setting at 4 (15.5-23.6 mA) was 3.63. Level 4 stimulation produced thumb adduction in 54% of subjects. No heart rate change occurred in response to nerve stimulation. CONCLUSION: Nerve stimulation by train-of-four method was moderately uncomfortable but not painful. Heart rate response could not be relied on as a measurement of discomfort. Protocols for stimulation should include testing at level 4 and increasing as necessary to cause thumb adduction.

Adult↗
PubMed1994

Applications of canarypox (ALVAC) vectors in human and veterinary vaccination.

This paper presents data derived from safety and efficacy studies of ALVAC-based rabies and feline leukemia virus (FeLV) vaccine candidates in target species. Inoculation of the ALVAC-RG recombinant was well tolerated in all species including humans and very young dogs. Protection induced in dogs against rabies challenge was long-lasting and could be elicited in the face of high levels of maternally-derived neutralizing antibody. Parenteral inoculation of cats with an ALVAC-FeLV recombinant was safe and induced protection against persistent infection following oro-nasal FeLV challenge.

Adult↗
PubMed1994

Safe and effective poxvirus vectors--NYVAC and ALVAC.

This paper describes the development and in vitro/in vivo characterization of two highly attenuated recombinant poxvirus vectors. The vectors, NYVAC and ALVAC, exhibit a restricted host range and a greatly enhanced degree of attenuation following inoculation into a range of animal species by a variety of routes. The safety profile of these vectors, together with their demonstrated ability to induce both humoral and cell-mediated immune responses to extrinsic antigens, makes them ideal candidates for use as vaccines in both human and veterinary disease situations.

Animals↗
PubMed1993

Influence of janusin and tenascin on growth cone behavior in vitro.

Janusin and tenascin are glia-derived, structurally related, extracellular matrix glycoproteins of the J1 family that are expressed in vivo at times and in locations where active neurite outgrowth occurs, but also when the formation or stabilization of cytoarchitectonic boundaries appears to be in operation. To resolve this apparent functional dichotomy, we have studied the behavioral response of growth cones, growing in culture on the permissive substrate laminin to janusin and tenascin, by video time lapse microscopy. When janusin and tenascin were offered as sharp substrate boundaries, dorsal root ganglion (DRG) and retinal ganglion neuron growth cones avoided growing on these molecules, but were not induced to collapse. On the other hand, when janusin and tenascin were offered, in a mixture with laminin, as uniform substrates, DRG growth cones displayed a collapsed morphology and were able to advance at a faster rate than on laminin alone. In contrast, the outgrowth of retinal ganglion neuron growth cones was completely inhibited under these conditions, underscoring a cell type specificity in the response of growth cones to these molecules. Using several monoclonal antibodies binding to distinct epitopes on the tenascin molecule, we have identified two domains responsible for growth cone repulsion, on epidermal growth factor (EGF)-like repeats 3-5 and fibronectin type III homologous repeats 4 and 5. These domains are different from the one previously recognized to be involved in neurite outgrowth on a uniform tenascin substrate. We conclude that both molecules may promote or retard growth cone advance, depending on the spatial expression pattern and the neuronal cell type.

Animals↗
PubMed1993

Activation of mucosal V beta 3+ T cells and tissue damage in human small intestine by the bacterial superantigen, Staphylococcus aureus enterotoxin B.

Staphylococcus aureus enterotoxin B (SEB) was added to explants of fetal human intestine in organ culture or administered into the lumen of fetal small intestine prior to culture. Both routes produced a massive increase in lamina propria T cells expressing V beta 3, and to a lesser extent, those expressing V beta 5 and V beta 12. SEB-activated lamina propria T cells produced interleukin-2 and interferon-gamma and T cell activation was accompanied by tissue damage, which was inhibited by FK506.

Antigens, Bacterial↗
PubMed1993

Development of a native plasmid as a cloning vector in Clavibacter xyli subsp. cynodontis.

A 50-kilobase (kb) cryptic plasmid was found in three geographic isolates of Clavibacter xyli subsp. cynodontis (Cxc). The DNA region essential for replication of the plasmid was cloned in an Escherichia coli vector. The resulting vector, which functions as a shuttle vector between E. coli and Cxc, was characterized further with respect to its stability and copy number.

Chloramphenicol Resistance↗
PubMed1993

Dose dependent effects of alcohol on visual evoked potentials.

The effects of various alcohol doses on components of the visual evoked potential were investigated. Using a repeated measures, Latin square design, five alcohol dose conditions were administered to ten male subjects: 0.00 (placebo); 0.28; 0.36; 0.54 and 0.72 g/kg total body weight. EEG responses to a reversing checker board stimulus were measured in a standard oddball paradigm. In the alcohol conditions, latencies of the P1 and P2 components of the VEP were unaffected. However, reaction time, and the latencies of N2 and P3 displayed significant dose related increases with increasing blood alcohol levels. Further, RMS power of the P3 complex was reduced by higher alcohol doses, as was the N2-P3 amplitude difference at central and parietal sites. It is concluded that the latency and power of the endogenous components of the VEP are altered by alcohol, without effects being seen in earlier components.

Adolescent↗
PubMed1993

Census enumeration in remote Australia: issues for Aboriginal data analysis.

"Given the crucial role played by census data in informing economic and social policies directed at the Aboriginal population in remote areas, some assessment of the quality of remote area data is required as these are derived from enumeration procedures which differ fundamentally from the standard approach employed in the census. This paper discusses the remote area census enumeration strategy employed by the Australian Bureau of Statistics (ABS), with a particular focus on the Northern Territory, and highlights possible implications for the interpretation of census counts and census characteristics."

Australia↗
PubMed1993

T-cell activation can induce either mucosal destruction or adaptation in cultured human fetal small intestine.

BACKGROUND: T-cell hypersensitivity is implicated in the tissue damage in a variety of gastrointestinal diseases. The aim of this study was to characterize the spectrum of pathological changes induced by T-cell activation in explants of fetal human small intestine, to modulate the pathology by immunological intervention, and to define the cellular pathways in intestinal damage. METHODS: Explants of fetal human small intestine were cultured with pokeweed mitogen in the presence or absence of dexamethasone or FK506. Pathological changes were then assessed by morphology or on frozen sections. RESULTS: Activation of lamina propria T cells produced variable mucosal damage that could be classified into two main types. Some explants showed villous atrophy and crypt hyperplasia whereas in others there was almost total mucosal destruction. This latter appearance predominated in explants from older specimens. Explants that were destroyed contained high numbers of T cells and activated macrophages. FK506 could completely inhibit mucosal damage, especially in younger specimens, whereas dexamethasone, even at high doses, prevented mucosal destruction, but individual explants continued to show villus atrophy and crypt hyperplasia. CONCLUSIONS: These results indicate that there is a quantitative relationship between mucosal cell-mediated immunity and the pathological outcome and that large numbers of activated macrophages in the mucosa can result in tissue destruction.

Adaptation, Physiological↗
PubMed1993

Regression of transitional cell carcinoma of the bladder with radiotherapy: progression-free control in the bladder at 5 years.

The five-year survival and the local control in the bladder at 5 years were determined for 67 patients with transitional cell carcinoma of the bladder. These 67 patients had been included in a previous study of the regression of carcinoma of the bladder with radical radiotherapy. For these 67 patients treated with radiotherapy alone after transurethral biopsy or excision, the cause-specific 5-year survival was 38.4% (95% confidence interval (CI), 26.5-50.3%), with an overall survival of 31.1% (95% CI, 20-42.2%). The local control in the bladder was 42.6% (95% CI, 29.2-56.0%) at 5 years.

Adult↗
PubMed1993

Education can never be neutral--teaching for subversion.

Nurse education is in the turbulent throws of political, demographic and ideological change, as many colleges adopt a curriculum to produce a new breed of nurse, through 'Project 2000'. Essentially however, those preparing these students for professional practice are often entrenched in the traditional and hierarchial tutor-student relationships with which we are all familiar. This paper seeks to explore the work of some radical educationalists with a view to presenting subversive teaching as a credible, and potentially desirable, entity. To cope with change and survive as a profession, nurse education cannot afford to throw out the bedpan along with its contents.

Assertiveness↗
PubMed1993

Cognitive decline in Alzheimer's disease: elaborating on the nature of the longitudinal factor structure of the Mini-Mental State Examination.

The purpose of this paper was to use the Wechsler Adult Intelligence Scale (WAIS) to further define the nature of the underlying factors of the Mini-Mental State Examination (MMSE) as proposed by Tinklenberg et al. (1990). The MMSE was administered to 51 patients once every 6 months for at least one year; the WAIS was administered only at the beginning of the study. Stepwise regression analyses yielded these results: for the Following Commands factor, the best correlate was the Comprehension subtest; for the Language Repetition factor, the best correlate was the Picture Arrangement subtest; and for the Language Expression factor, the best correlates were the Digit Symbol and Object Assembly subtests. These relations help clarify the correlates of decline of AD patients on the MMSE.

Aged↗
PubMed1993

Metastatic prostate cancer simulating sclerosing cholangitis.

We report what we believe to be the first case of metastatic prostate cancer presenting as sclerosing cholangitis. In a 71-year-old man with known prostate cancer and cholestatic jaundice, an endoscopic retrograde cholangiopancreatography revealed multifocal strictures of both the intrahepatic and extrahepatic biliary system consistent with sclerosing cholangitis. Review of a liver biopsy and cholecystectomy specimen showed metastases from prostate cancer, which stained positively with prostate-specific antigen. Multiple hepatic metastases from prostate cancer should be included among the conditions that simulate primary sclerosing cholangitis on cholangiography.

Adenocarcinoma↗
PubMed1993

Isotretinoin for acne vulgaris--10 years later: a safe and successful treatment.

The purpose of this study was to assess the long-term benefit of isotretinoin in otherwise therapy-resistant acne. We also assessed risk factors which might influence the long-term outcome. We studied 88 patients (mean age 20.8 years), most of whom had suffered from acne for many years (mean 7.4 years). They received isotretinoin in an initial dose of 0.5 or 1.0 mg/kg/day. The dose was subsequently adjusted according to response and side-effects. Most patients only required 4 months' therapy to produce at least 85% clinical improvement. The patients were seen up to 10 years post-therapy (mean 9 years). Sixty-one patients were still virtually clear of disease. Of the others, 16% required further treatment with conventional antibiotics and 23% required a second course of isotretinoin. Of those who relapsed, 96% did so within 3 years of stopping therapy. The patients' age, sex, and duration of acne did not influence outcome. However, in patients with predominantly truncal acne, especially when severe, there was an increased incidence of relapse. Sebum excretion is known to correlate with acne severity, but the long-term degree of sebum suppression was found not to be related to relapse. The dose schedule, in particular cumulative dose, was an important factor in determining relapse rate. Those patients who received 0.5 mg/kg daily, or a cumulative dose of < 120 mg/kg, had a significantly higher relapse rate than patients receiving a larger dose. We did not elicit any long-term systemic or biochemical side-effects. We conclude that isotretinoin is a safe and effective therapy.(ABSTRACT TRUNCATED AT 250 WORDS)

Acne Vulgaris↗
PubMed1993

The RNAs of hepatitis delta virus are copied by RNA polymerase II in nuclear homogenates.

Human hepatitis delta virus has a single-stranded circular RNA genome that replicates by RNA-directed RNA synthesis. The virus encodes only a single protein, the delta antigen, which both is small (22 kDa) and lacks sequence homology to known RNA polymerases, suggesting that the virus employs a cellular polymerase for replication. Consistent with this suggestion, we have used homogenized nuclei from a human hepatoma cell line, HepG2, to demonstrate RNA-directed RNA synthesis from both genomic hepatitis delta virus RNA and its complement, the antigenomic RNA. RNA polymerase II was responsible for this transcription because the reaction was inhibited both by low doses of alpha-amanitin and by a monoclonal antibody specific for polymerase II. In addition, it was found that the majority of the RNA products were processed, presumably by self-cleavage and self-ligation, to produce covalently closed circular molecules.

Amanitins↗
PubMed1993

Ribonucleoprotein complexes of hepatitis delta virus.

Human hepatitis delta virus (HDV) is a subviral satellite agent of hepatitis B virus (HBV). The envelope proteins of HDV are provided by the helper virus, HBV, but very little is known about the internal structure of HDV. The particles contain multiple copies of the delta antigen and an unusual RNA genome that is small, about 1,700 nucleotides in length, single stranded, and circular. By using UV cross-linking, equilibrium density centrifugation, and immunoprecipitation, we obtained evidence consistent with the interpretation that delta antigen and genomic RNA form a stable ribonucleoprotein (RNP) complex within the virion. Furthermore, electron-microscopic examination of the purified viral RNP revealed a roughly spherical core-like structure with a diameter of 18.7 +/- 2.5 nm. We also isolated HDV-specific RNP structures from the nuclei of cells undergoing HDV genome replication; both the genome and antigenome (a complement of the genome) of HDV were found to be in such complexes. From the equilibrium density analyses of the viral and nuclear RNPs, we were able to deduce the number of molecules of delta antigen per molecule of HDV RNA. For virions, this number was predominantly ca. 70, which was larger than for the nuclear RNPs, which were more heterogeneous, with an average value of ca. 30.

Animals↗