Search PubMed⌕ Search

Biomedical subjects

K Jones

Publications and source records attributed to K Jones.

At least 235 records · Page 13Linked to original sources
PubMed1995

Infection of human endothelial cells with Epstein-Barr virus.

Interleukin-6 (IL-6) promotes growth and tumorigenicity of Epstein-Barr virus (EBV)-immortalized B cells, and is abnormally elevated in the serum of solid organ transplant recipients who develop EBV-positive posttransplant lymphoproliferative disease (PTLD), but not in control transplant recipients. Endothelial cells derived from PTLD lesions were found to secrete spontaneously high levels of IL-6 in vitro for up to 4 mo. We examined possible mechanisms for sustained IL-6 production by endothelial cells. Here, we show that EBV can infect endothelial cells in vitro. After 3-4 wk incubation with lethally irradiated EBV-positive, but not EBV-negative cell lines, a proportion of human umbilical cord-derived endothelial cells (HUVECs) expressed in situ the EBV-encoded small RNAs (EBER). Southern blot analysis after polymerase chain reaction showed EBV DNA in HUVEC that had been incubated with lethally irradiated EBV-positive cells, but not in the controls. Exposure of HUVECs to lethally irradiated EBV-positive but not EBV-negative cell lines induced IL-6 production that was sustained for up to 120 d of culture. These studies identify endothelial cells as targets for EBV infection and raise the possibility that this infection may be important in the life cycle and pathology of EBV.

Base Sequence↗
PubMed1995

Medical eligibility, comprehension of the consent process, and retention of injection drug users recruited for an HIV vaccine trial.

Injection drug users (IDUs) at high risk for human immunodeficiency virus (HIV) infection are being identified as a population for HIV vaccine trials. We studied willingness of drug users to enroll and their comprehension of consent procedures in the context of a Phase II trial at one site. Of 175 people screened for enrollment and whose data sets were complete, 119 (68%) were IDUs. Of the 71 who were eligible, 39 (55%) were IDUs. Exclusion of IDUs was usually for medical reasons. Using a 17-item true/false test, comprehension of the informed consent procedure was high (median score, 16 of 17 for IDUs and non-IDUs); only three subjects (all of whom were IDUs) were excluded from enrollment due to lack of comprehension. Follow-up rates were similar for IDUs and non-IDUs. These data suggest that recruitment of IDUs into HIV vaccine trials is feasible, that IDUs can comprehend and complete the informed consent procedures, and that they return for follow-up visits.

AIDS Vaccines↗
PubMed1995

Widespread anatomical projections of the serotonergic modulatory neuron, CB1, in Aplysia.

Although sensitization-related changes in the neural circuitry of withdrawal reflexes in Aplysia are well studied, relatively few studies address the organization of the modulatory components of sensitization. In particular, it is not known whether individual modulatory loci can simultaneously influence multiple reflex circuits. There is, however, evidence that a single modulatory transmitter, serotonin, plays a pivotal role in facilitating different reflex circuits during sensitization. Furthermore, it is known that activation of a pair of serotonergic neurons, the CB1s, produces heterosynaptic facilitation of the sensorimotor connections of one of these reflex circuits. These data together raise the possibility that the CB1s may produce sensitizing changes in the neural elements of multiple reflex systems simultaneously. In the present study, we utilized immunocytochemistry and intracellular labeling to obtain anatomical evidence of CB1's possible role in modulating multiple reflex circuits. We found that two distinct neurons satisfy previously published physiological criteria for CB1. One of these, CB1, is immunoreactive to serotonin. The second cell, here named CB2, has a different neuroanatomy and is not serotonin immunoreactive. Focusing on CB1, we found (1) profuse fine processes given off by its axons in the posterior neuropil of the cerebral ganglion, (2) extensive branching and fine processes in the pleural ganglion, and (3) a branch of CB1 that projects into the pedal ganglion. These three observations are consistent with the hypothesis that, in addition to its already established role in modulating the siphon withdrawal circuit, CB1 may also modulate synaptic connections between (1) the sensory and motor neurons of the tentacle withdrawal reflex (2) the sensory neurons and interneurons of the tail and tail-elicited siphon withdrawal reflex, and (3) the sensory and motor neurons of the tail withdrawal reflex. These observations support further physiological investigations of a possible global role of CB1 in modulating the tail and tentacle withdrawal reflexes.

Animals↗
PubMed1995

Does the limb swell after revascularisation by percutaneous transluminal angioplasty?

OBJECTIVE: To discover if limb swelling occurs after successful revascularisation by percutaneous transluminal angioplasty (PTA). DESIGN: Prospective Study. SETTING: Vascular Laboratory. MATERIALS: Twenty-five patients with occlusive arterial disease of the lower limb revascularised by percutaneous transluminal angioplasty were studied. CHIEF OUTCOME MEASURES: The ankle/brachial pressure index and foot volumes measured by water displacement plethysmography were measured before and after PTA. MAIN RESULTS: The volume of the revascularised limb increased by 2% on the first day postangioplasty (p = 0.009) and 4% on the 7th day (p < 0.001) compared with the contralateral leg. CONCLUSIONS: Leg swelling is a consequence of revascularisation of the ischaemic limb and occurs in the absence of damage to the lymphatic drainage of the limb.

Angioplasty, Balloon↗
PubMed1995

Predictors of cognitive change in older persons: MacArthur studies of successful aging.

This study used a linear structural relations modeling technique (LISREL) to examine longitudinal data for 1,192 persons from a community-based population. The goal was to test the ability of an a priori model to predict cognitive change over a 2.0- to 2.5-year period in older adults aged 70-79 at the initial evaluation. The model included 22 demographic, physical, and psychosocial variables as predictors of cognitive function and cognitive change. The study used an exploratory-confirmatory design, enabling cross-validation of the model developed in the exploratory set in the confirmatory sample. Structural equation modeling analyses identified 4 endogenous model variable (education, strenuous activity, peak pulmonary expiratory flow rate, and self-efficacy) as direct predictors of cognitive change over the study period.

Aged↗
PubMed1995

Heteronuclear NMR studies of the chromone alkaloids and revision of the structure of some piperidino-chromone alkaloids.

The 13C-NMR spectra of seven chromone alkaloids isolated from Schumanniophyton magnificum have been obtained. Assignment of signals was carried out with the help of heteronuclear coupling experiments and other correlation techniques on the alkaloids and their acyl derivatives. On the basis of the signals observed the structures of the piperidino-alkaloid schumannificine and its N-methyl and anhydro analogues have been revised to that of a piperidone ring linked to the noreugenin via a carbon-carbon bond and a lactol bridge.

Alkaloids↗
PubMed1995

The use of hormone replacement therapy; results of a community survey.

Hormone replacement therapy is used for both menopausal symptoms and in prevention, but for the latter to be effective there may be a need to promote its use. Suitable strategies need to be informed by current practice. A postal questionnaire was therefore sent to 1649 women aged 20-69 years in Stockton-on-Tees to assess which women consider and take hormone replacement therapy. The response rate was 74%. Therapy had been considered by 346 (28%) women of whom 164 (47%) were premenopausal. It was taken by 20% of women aged 45-65 years. Users were more likely to have taken the contraceptive pill. Use of therapy by women with osteoporosis or cardiovascular disease, or with a family history of these, was low. As women used to the idea of taking hormone replacement therapy and accustomed to taking the contraceptive pill reach menopausal age there is likely to be an increase in uptake of therapy. By targeting the 'at risk' groups of women, the primary care team may be able to make most effective use of the therapy and their own resources for the prevention of osteoporosis and cardiovascular disease.

Adult↗
PubMed1995

Evaluation of antral motility in humans using manometry and scintigraphy.

Recent studies suggest that scintigraphy can be used to evaluate non-invasively antral motility in humans, although scintigraphic techniques have not yet been compared with more conventional measurements of intraluminal pressures by manometry. Simultaneous scintigraphic and manometric measurements of antral motility were performed in nine healthy volunteers. After intubation with a sleeve/sidehole catheter which incorporated five pressure sideholes located at 1.5 cm intervals spanning the antrum, each subject ingested 100 g minced beef labelled with 100 MBq 99mTc-chicken liver and 150 ml water. Between 40-43, 60-63, 80-83, and 100-103 minutes after meal ingestion, radioisotopic data were acquired in two second frames. Time-activity curves showing antral 'contractions' resulting from wall motion were derived by drawing small regions of interest over the antrum to coincide with the position of the antral manometric sideholes. Scintigraphic contraction rates approximated 3/minute, whereas antral pressure waves that occluded the lumen were less frequent (p < 0.01 for all), particularly in the proximal antrum. The amplitude of wall motion, evaluated scintigraphically, and the amplitude of pressure waves were both inversely related to the distance from the pylorus (r > -0.32, p < 0.05) and antral volume r > -0.29 (p < 0.05). There were significant relationships between the amplitude of contractions assessed scintigraphically and the number of lumen-occlusive antral pressure waves in the distal antrum (r -0.48, p < 0.05) but not in the more proximal antral regions. It is concluded that scintigraphy can detect antral wall motion with greater sensitivity than manometry, particularly in the proximal antrum. As manometry gives information on the amplitude as well as the temporal and spatial organisation of those contractions which result in lumen occlusion, the combination of scintigraphic and manometric techniques in the evaluation of antral motility shows considerable promise.

Adult↗
PubMed1995

Psychiatric morbidity: a multilevel approach to regional variations in the UK.

STUDY OBJECTIVE: To establish whether regional variations in psychiatric morbidity in Britain constitute a distinctive geography of mental health arising from factors that are context-specific at area level or whether these variations are an artifact generated by sampling fluctuations and differing population compositions in areas. DESIGN: Multilevel modelling techniques were applied to data from the 1984-85 health and lifestyle survey. The outcome was the prevalence of psychiatric morbidity as recorded by the application of the general health questionnaire in this survey. SETTING: The analysis was undertaken simultaneously at the individual level, electoral ward level, and regional level for England, Wales, and Scotland. PARTICIPANTS: A total of 6572 adults were selected from the electoral register. MAIN RESULTS: Regional variations were detected in crude aggregate general health questionnaire scores but these were found to be the result of sampling fluctuations and varying regional population compositions rather than higher level contextual effects. There was certainly no evidence of a clear north-south distinction in psychiatric morbidity as was suggested by earlier work. In addition, the local neighbourhood did not seem to have any importance beyond the type of people who lived there. A number of individual characteristics was shown to be associated with mental wellbeing but a large degree of individual variation remained unexplained. CONCLUSIONS: In terms of low level psychiatric disturbance it seems that the characteristics of individuals have greater importance than the characteristics of areas, although the latter may still operate as important mediating factors. Multilevel modelling represents a robust statistical method of examining area variations in health outcomes and further work needs to be conducted, particularly on more serious psychiatric conditions.

Adult↗
PubMed1995

Relationship between surface electrogastrography and antropyloric pressures.

The cutaneous electrogastrogram (EGG) and intraluminal antropyloroduodenal pressures were recorded in 12 healthy volunteers for 30-min periods during phase II of the interdigestive motor complex, during intraduodenal infusion of 10% triglyceride, and after intravenous erythromycin (3 mg/kg). During phase II, the frequency of the EGG was relatively constant in each individual, with a median frequency of 0.046 Hz [2.8 counts per minute (cpm)]. EGG frequency was greater (P < 0.05) than the median rate of antral pressure waves (1.8 cpm). The suppression of antral pressure waves (P < 0.05) and stimulation of isolated pyloric pressure waves (IPPWs) (P < 0.05) produced by triglyceride infusion were not associated with changes in EGG frequency compared with phase II. The frequency of the EGG and the rate of IPPWs were comparable. After erythromycin, EGG frequency was 0.03 Hz (1.8 cpm), less than during both phase II and triglyceride infusion (P < 0.05) and almost identical to the rate of antral pressure waves. Pressure waves were nearly always associated with an EGG signal. In contrast, the temporal relationship between the EGG signal and pressure waves was variable. During triglyceride infusion (r = 0.83, P < 0.001) and after erythromycin (r = 0.83, P < 0.001) there was a close (approximately 1:1) relationship between the rate of pressure waves and EGG frequency. However, there was no significant relationship (r = 0.32, not significant) between the number of pressure waves and EGG frequency frequency during pase II.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1995

A preliminary comparison of reinforcer assessment methods for children with attention deficit hyperactivity disorder.

We evaluated the relative treatment utility of a verbal forced-choice questionnaire, child nomination, and direct observation for identifying the most potent reinforcers for children with attention deficit hyperactivity disorder. Results demonstrated that all three methods were more likely to disagree than to agree, that a forced-choice format may enhance verbal reinforcer assessment, and that further development and evaluation of verbal reinforcer-assessment methods are needed.

Attention Deficit Disorder with Hyperactivity↗
PubMed1995

Delivering the message. Communications is a vital link in the strategic chain.

Healthcare providers often treat communications as an afterthought when it comes to strategic planning. But that is a mistake in the 1990s. As providers adapt to the new managed care environment, marketing will be more important than ever. In recent years, providers have tended to devote much of their marketing budgets to advertising. The need to advertise will continue, but hospitals are increasingly using communications skills to educate consumers about changes in the healthcare system, the services available, and ways to get access to them. Hospitals are also marketing their staffs of associated physicians. They are launching community outreach efforts, both in city neighborhoods and in affluent suburbs. Realizing that women make most family healthcare decisions, hospitals are putting healthcare information booths in local shopping malls. Providers also need to keep in mind the changing nature of their "customers." Frequently, customers are not individuals but employers, insurers, and health maintenance organizations. To remain competitive, providers must demonstrate their cost-effectiveness to such payers through skillful communications.

Consumer Behavior↗
PubMed1995

Retrospective review of the prevalence and management of infertility in women in one practice over a five year period.

BACKGROUND: Subfertility in general practice is a common problem. However, most treatment is initiated in hospital. There may be a role for general practitioners in the treatment of some infertile patients. AIM: The aim of this study was to investigate the prevalence and management of infertility in women in general practice and to identify a specific cohort of patients potentially suitable for management in primary care. METHOD: The general practice notes of all women patients between the ages of 16 and 42 years who presented to their general practitioner with an infertility problem in the five years preceding July 1993 were analysed retrospectively. The patients were identified from the computer database of one Durham general practice. RESULTS: Fifty four cases were identified over the five year period, giving a prevalence of infertility in women in the practice of 15 per 1000 women. Of those who had a definite diagnosis made, 27% had an ovulatory disorder. Women with an ovulatory disorder tended to have a low serum day 21 progesterone level (90%); to present with primary infertility (80%); and to receive clomiphene as first line therapy (80%). The majority of ovulation induction therapy (95%) was initiated in secondary care. CONCLUSION: Ovulation induction therapy with clomiphene appears to be uncommon in general practice at present. Women requiring ovulation induction therapy may be a cohort of patients suitable for such management in general practice. These patients tend to present with primary infertility and to have a low mid-luteal progesterone level.

Adolescent↗
PubMed1995

A pilot study of zileuton, a novel selective 5-lipoxygenase inhibitor, in patients with systemic lupus erythematosus.

OBJECTIVE: This is a pilot study of zileuton, a selective 5-lipoxygenase inhibitor in systemic lupus erythematosus (SLE). METHODS: Forty patients with SLE received zileuton 600 mg qid or placebo in an 8 week, randomized prospective, double blind trial. Disease activity was manifested largely by constitutional, articular, and skin manifestations with no evidence of active renal, cardiac, or neurologic involvement. Concomitant administration of nonsteroidal antiinflammatories, corticosteroids, or antimalarials was not permitted. Disease activity was determined at baseline and at Days 15 and 57 by assessment of arthritis severity, the Systemic Lupus Activity Measure (SLAM), investigator and patient global ratings, hematologic indices, and serologic measures including autoantibody titers, complement levels, and interleukin 2 receptors (IL-2R). Total body sulfidopeptide leukotriene synthesis was measured by urinary leukotriene E4 (LTE4) concentrations. RESULTS: Overall SLAM (the primary measure of efficacy in this study) was significantly improved with zileuton compared with placebo (-2.1 +/- 1.3, compared with an increase of 2.3 +/- 1.3 with placebo by Day 57, p = 0.048). Changes in individual SLAM subscores, arthritis severity, global ratings, and IL-2R levels compared with baseline did not achieve statistical significance, but were generally decreased from baseline with zileuton (indicating trends towards improvement) and increased from baseline with placebo (indicating trends towards clinical worsening). Urine LTE4 levels at Day 57 had increased from baseline in the placebo group (indicating worsening) and decreased in the zileuton group (indicating improvement). CONCLUSION: Selective 5-lipoxygenase inhibition may be beneficial in mild SLE.

Adult↗