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Biomedical subjects

L Jones

Publications and source records attributed to L Jones.

At least 19 recordsLinked to original sources
PubMed1992

Atrial fibrillation and stroke: prevalence in different types of stroke and influence on early and long term prognosis (Oxfordshire community stroke project)

OBJECTIVE: To determine in patients with first ever stroke whether atrial fibrillation influences clinical features, the need to perform computed tomography, and prognosis. DESIGN: Observational cohort study with maximum follow up of 6.5 years. SETTING: Primary care, based on 10 general practices in urban and rural Oxfordshire. SUBJECTS: Consecutive series of 675 patients with first ever stroke registered in the Oxfordshire community stroke project. MAIN OUTCOME MEASURES: Prevalence of atrial fibrillation by type of stroke; effect of atrial fibrillation on case fatality rate and risk of recurrent stroke, vascular death, and death from all causes. RESULTS: Prevalence of atrial fibrillation was 17% (95% confidence interval 14% to 20%) for all stroke types (115/675), 18% (15% to 21%) for cerebral infarction (97/545), 11% (4% to 11%) for primary intercerebral haemorrhage (7/66), and 0% (0 to 11%) for subarachnoid haemorrhage (0/33). For patients with cerebral infarction the 30 day case fatality rate was significantly higher with atrial fibrillation (23%) than with sinus rhythm (8%); the risk of early recurrent stroke (within 30 days) was 1% with atrial fibrillation and 4% with sinus rhythm. In patients who survived at least 30 days the average annual risk of recurrent stroke was 8.2% (5.9% to 10.9%) with sinus rhythm and 11% (6.0% to 17.3%) with atrial fibrillation. CONCLUSIONS: After a first stroke atrial fibrillation was not associated with a definite excess risk of recurrent stroke, either within 30 days or within the first few years. Survivors with and without atrial fibrillation had a clinically important absolute risk of further serious vascular events.

Aged↗
PubMed1992

Vaccinia virus recombinants expressing chimeric proteins of human immunodeficiency virus and gamma interferon are attenuated for nude mice.

We have developed a method for attenuating vaccinia virus recombinants by expressing a fusion protein of a lymphokine and an immunogen. Chimeric genes were constructed that coded for gamma interferon (IFN-gamma) and structural proteins of the human immunodeficiency virus type 1 (HIV-1). In this study, we describe the biological and immunological properties of vaccinia virus recombinants expressing chimeric genes of murine or human IFN-gamma with glycoprotein gp120, gag, and a fragment of gp41. All fusion proteins retained the antigenic characteristics of both IFN-gamma and HIV as shown by immunoblot analysis. However, the antiviral activity of IFN-gamma could be demonstrated only for the IFN-gamma-gag fusion protein. In contrast, the attenuating activity of IFN-gamma for nude mice was retained by all of the recombinants, albeit at various rates. Unlike the antiviral activity, the attenuating activity of IFN-gamma was not species specific. Implications for the development of attenuated live recombinant vaccines for AIDS are discussed.

Amino Acid Sequence↗
PubMed1992

Multiple swallows and piecemeal deglutition; observations from normal adults and patients with head and neck cancer.

The incidence of multiple swallows for liquid and paste, and the time delay between multiple swallows, was determined from videofluoroscopic records of modified barium swallow tests. In a comparison of liquid and paste, the overall incidence of multiple swallows did not differ, for either patients with head and neck cancer or normal controls. However, for liquid swallows the incidence in patients with cancer was abnormally high, predominantly in patients with pharyngeal cancer.

Adult↗
PubMed1992

Scintigraphic quantification of pharyngeal retention following deglutition.

A procedure is described for quantifying the amount of bolus material retained in the pharynx after completion of a swallow, using radionuclide swallow techniques. Data are derived from scintigraphic time-activity curves. The procedure takes into consideration the differential attenuation of radioactivity through various regions in the body, and expresses the result as a percentage of the total radioactivity in the ingested bolus. Illustrative examples are provided for swallows by normal individuals and patients with head and neck cancer.

Adult↗
PubMed1992

Comparison of acellular (B type) and whole-cell pertussis-component diphtheria-tetanus-pertussis vaccines as the first booster immunization in 15- to 24-month-old children.

We compared an acellular (B type) pertussis-component diphtheria-tetanus-pertussis (DTP-Ac) vaccine containing equal amounts of filamentous hemagglutinin and lymphocytosis-promoting factor with a conventional whole-cell vaccine as the first booster immunization in 162 healthy children 15 to 24 months of age. Fewer local reactions (e.g., erythema, swelling, and tenderness at the injection site) were seen in DTP-Ac vaccine recipients during the first 48 hours of observation. This group also had fewer episodes of fever (> or = 38 degrees C) and other systemic reactions (e.g., irritability, drowsiness, and anorexia). Overall, 57% of the DTP-Ac vaccine recipients had no obvious adverse reactions, in contrast to 5% in the comparison group. At 4 to 8 weeks after vaccination, serum antibody responses to filamentous hemagglutinin and lymphocytosis-promoting factor were greater in recipients of the acellular vaccine as determined by an enzyme-linked immunosorbent assay. We conclude that this B-type acellular vaccine is both immunogenic and much less likely to cause an adverse reaction than a currently licensed whole-cell vaccine, and is suitable for routine booster immunizing doses to protect against pertussis.

Analysis of Variance↗
PubMed1992

Breast self examination and survival from breast cancer.

The survival of 616 women aged 15-59 with breast cancer, 226 of whom had been taught and practised breast self examination (BSE) prior to diagnosis and 390 of whom had not, is reported. Six year survival rates were 73.1% in the BSE taught group and 66.1% in other women (P = 0.07).

Adolescent↗
PubMed1992

Disturbance in renal haemodynamics and physiology in bone marrow transplant recipients treated with ciclosporin A.

The vascular disturbance associated with ciclosporin (CS) nephrotoxicity is poorly defined in both the normal and transplanted human kidney. Six bone marrow transplant recipients were studied before, during and after administration of CS. By analysis of time activity curves and clearance of Tc-99m DTPA, renal blood flow (RBF), filtration fraction (FF) and GFR were shown to fall on CS (GFR: p less than 0.001; RBF, FF: p less than 0.01). These haemodynamic variables did not fully recover with dose reduction or after discontinuation of therapy. Plasma renin activity (PRA) aldosterone and atrial natriuretic peptide did not change although there appeared a tendency for PRA to fall on CS. There was a reversible normokalemic metabolic acidosis. CS levels stayed within the therapeutic range. The partial reversibility of GFR, RBF and FF is consistent with CS-induced functional disturbance and reflects sensitivity to microvascular and tubular injury of the normal human kidney.

Adolescent↗
PubMed1992

von Willebrand factor as a marker of endothelial cell activation following BMT.

Endothelial cell activation may play a role in thrombotic complications of BMT such as hepatic veno-occlusive disease (VOD), right atrial line thrombosis and microangiopathic haemolysis. To assess this, von Willebrand factor antigen (vWF:ag) was measured in 72 patients (25 allografts, 46 autografts and one syngeneic) during the first 6 weeks post-transplant. There was a significant rise in vWF:ag in both allografts and autografts but a greater increase was seen in the allografts. The changes in vWF:ag did not correlate with changes in C reactive protein showing that this was not merely an acute phase response. vWF multimers were normal in a subgroup of uncomplicated transplants showing that there was no large scale endothelial cell disruption. Patients with VOD did not have changes in vWF:ag that were consistently different from uncomplicated controls. Three of four patients who developed line thrombosis had higher levels of vWF:ag compared with control groups; multimeric structure of the vWF was again normal. These results show that there is endothelial cell activation post-BMT and that this is greater in allografts compared with autografts, thus suggesting a possible mechanism for the higher incidence of VOD in this group. There were no useful predictive markers of VOD or thrombosis in individual patients.

Adolescent↗
PubMed1991

A vaccinia virus double recombinant expressing the F and H genes of rinderpest virus protects cattle against rinderpest and causes no pock lesions.

Rinderpest is a highly contagious viral disease of ruminants with greater than 95% morbidity and mortality. We have constructed an infectious vaccinia virus recombinant that expresses both the fusion (F) gene and the hemagglutinin (H) gene of rinderpest virus. The Wyeth strain of vaccinia virus was used for the construction of the recombinant. Cattle vaccinated with the recombinant virus were 100% protected from challenge inoculation with greater than 1000 times the lethal dose of rinderpest virus. No transmission of recombinant vaccinia virus from vaccinated animals to contact animals was observed. The lyophilized form of vaccinia virus is thermostable and allows circumvention of the logistical problems associated with the distribution and administration of vaccines in the arid and hot regions of Asia and Africa. The insertional inactivation of both the thymidine kinase and the hemagglutinin genes of vaccinia virus led to increased attenuation of the virus; this was manifested by the lack of detectable pock lesions in vaccinated animals. This approach may have wide application in the development of safe and efficacious recombinant vaccines for humans and animals. This becomes quite relevant with the concern of the use of vaccinia virus in a population with high incidence of the human immunodeficiency virus.

Animals↗
PubMed1991

Fibrinogen and lipid concentrations as risk factors for transient ischaemic attacks and minor ischaemic strokes.

OBJECTIVES: To determine whether fibrinogen and lipid concentrations are risk factors for ischaemic stroke. DESIGN: Case-control study with a population based comparison within the overall study. SETTING: Oxfordshire community stroke project and a neurology clinic. SUBJECTS: 105 patients who had a transient ischaemic attack or minor ischaemic stroke and 352 randomly chosen controls matched for age and sex from the same general practitioners as the incident cases. 52 controls were ineligible or refused interview. 104 cases and 241 controls gave blood samples for analysis. MAIN OUTCOME MEASURES: Response to structured questionnaire, height, weight, blood pressure, and serum concentrations of fibrinogen and lipids. RESULTS: Adjusted for other variables, odds ratios of ischaemic stroke were 1.78 (95% confidence interval 0.91 to 3.48; p = 0.09) [corrected] for fibrinogen concentrations greater than 3.6 g/l; 1.73 (0.90 to 3.29; p = 0.09) [corrected] for total cholesterol concentrations greater than 6.0 mmol/l; 1.34 (0.69 to 2.61; p greater than 0.4) for low density lipoprotein cholesterol concentrations greater than 3.5 mmol/l; and 0.32 (0.15 to 0.69; p = 0.002) for high density lipoprotein cholesterol concentration greater than 1.2 mmol/l. Similar results emerged comparing only community derived cases with transient ischaemic attacks and controls. The effects of fibrinogen, total cholesterol, and high density lipoprotein cholesterol were significant in a test of trend after adjusting for all other variables in the study (chi 2 = 4.14, p less than 0.05; chi 2 = 4.31, p less than 0.05, and chi 2 = 12.15, p greater than 0.001, respectively). History of ischaemic heart disease and hypertension were the only other variables that showed significance, though both lost significance after adjustment (2.06, p = 0.08 and 1.53, p = 0.2, respectively). CONCLUSIONS: Fibrinogen and lipids are important risk factors for ischaemic stroke. The pattern of changes mirrors that found in ischaemic heart disease.

Adult↗
PubMed1991

Fetal fibronectin in cervical and vaginal secretions as a predictor of preterm delivery.

BACKGROUND: Preterm delivery is the leading cause of neonatal mortality in the United States, but efforts to address the problem are hampered by the inability to predict accurately which pregnancies are at risk. We postulated that damage to the fetal membranes may release fetal fibronectin into the cervix and vagina, giving rise to a biochemical marker for preterm delivery. METHODS: We measured fetal-fibronectin concentrations in cervical and vaginal secretions, amniotic fluid, and maternal plasma with a sensitive immunoassay using the monoclonal antibody FDC-6. Immunohistochemical studies were used to determine the distribution of fetal fibronectin in the placenta and amniochorionic membranes and to ascertain its cell of origin. RESULTS: Women with uncomplicated pregnancies (n = 163) who delivered at term rarely had cervicovaginal fetal-fibronectin concentrations above 0.05 micrograms per milliliter between 21 and 37 weeks of gestation (11 of 267 cervical samples [4 percent] and 9 of 267 vaginal samples [3 percent]. High levels of fetal fibronectin were detected in amniotic fluid and in the cervical or vaginal secretions of 93.8 percent of the women with preterm rupture of membranes (n = 65). Cervical or vaginal fetal fibronectin was also present in 50.4 percent of the women with preterm uterine contractions and intact membranes (n = 117), and its presence identified the women who delivered before term (n = 60) with a sensitivity of 81.7 percent and a specificity of 82.5 percent. In the placenta and membranes, fetal fibronectin was found at points of contact with the uterine wall. CONCLUSIONS: The presence of cervicovaginal fetal fibronectin in the second and third trimesters of pregnancy identifies a subgroup of women who are at high risk for preterm delivery. This phenomenon may reflect the separation of the chorion from the decidual layer of the uterus, with the release of intact or degraded chorionic components of the extracellular matrix into the cervical and vaginal secretions.

Amniotic Fluid↗
PubMed1991

Use of computerised general practice data for population surveillance: comparative study of influenza data.

OBJECTIVE: To assess the potential for using routine computerised general practice data for surveillance of illness. DESIGN: Comparison of the incidence of influenza during the 1989 epidemic derived from a computerised database with that derived from the Royal College of General Practitioners's weekly returns service--a well established predominantly manual surveillance system. SETTING: 433 general practices throughout the United Kingdom that used a commercial computer system linked to a central databank. MAIN OUTCOME MEASURE: Incidence of influenza. RESULTS: The slope of the influenza epidemic curve was essentially the same whether derived from the routine computerised data or royal college's weekly returns service data, and the computerised data were geographically consistent. Throughout the study period, however, the computer derived incidence was between one third and one quarter of that derived from the royal college's system (which is served by practitioners trained in surveillance methods). The peak weekly rates were 164 cases per 100,000 for the computerised system and 583 cases per 100,000 for the royal college's surveillance system. CONCLUSIONS: The apparent underreporting in the routine computerised data probably reflects lack of motivation and experience in disease surveillance and haphazard computer entry (particularly of consultations that took place outside of the surgery and consultations that did not result in a prescription), along with overestimation of the population under surveillance. Nevertheless, routine computerised surveillance allows rapid data collection from a large number of practices over a wide geographical area and would greatly augment existing methods.

Computer Systems↗
PubMed1991

Molecular cloning of rat cardiac troponin I and analysis of troponin I isoform expression in developing rat heart.

We have isolated and sequenced a cDNA encoding rat cardiac troponin I. The predicted amino acid sequence was highly identical with previously reported chemically derived amino acid sequences for rabbit and bovine cardiac troponin I. Clones for slow skeletal muscle troponin I were also obtained from neonatal rat cardiac ventricle by the polymerase chain reaction. The nucleotide sequences of these clones were determined to be more than 99% identical with a previously reported rat slow skeletal troponin I cDNA [Koppe et al. (1989) J. Biol. Chem. 264, 14327-14333]. The troponin I clones hybridized to RNA from the appropriate muscle from adult animals. However, RNA from fetal and neonatal rat heart also hybridized with the slow skeletal troponin I cDNA, demonstrating its expression in fetal and neonatal rat heart. Slow skeletal troponin I steady-state mRNA levels decreased with increasing age, but cardiac troponin I mRNA levels increased through fetal and early neonatal cardiac development. Thus, during fetal and neonatal development, slow skeletal and cardiac troponin I isoforms are coexpressed in the rat heart and regulated in opposite directions. The degree of primary sequence differences in these isoforms, especially at phosphorylation sites, may result in important functional differences in the neonatal myocardium.

Amino Acid Sequence↗
PubMed1991

Limitations of surgery in the treatment of retroperitoneal sarcoma.

A retrospective analysis was undertaken of 120 patients with retroperitoneal sarcoma referred to the Royal Marsden Hospital over a period of 20 years. The actuarial 5-year survival rate of all cases following referral was 29 per cent. On univariate and multivariate analysis the principal factors associated with an unfavourable prognosis were the presence of metastases, poor performance status at presentation, high tumour grade and incomplete excision of the primary tumour. The single most important factor affecting the ability to remove the primary tumour completely was multiple organ involvement. After apparently complete excision, however, the probability of local recurrence by 5 years was 85 per cent (95 per cent confidence interval 56-99). The prognosis of patients with retroperitoneal sarcoma is poor.

Adolescent↗
PubMed1991

Integrating research activities, practice changes, and monitoring and evaluation: a model for academic health centers.

A study undertaken by the Joint Commission in 1986 proposed that some research activities at academic health centers (AHCs) be used to fulfill monitoring and evaluation requirements. This paper presents a framework for such use of research activities. To fulfill the monitoring and evaluation standards, AHCs and their medical staff departments must conduct planned and systematic quality assurance activities, and research and subsequent practice changes must be documented. In addition, particular research activities should correspond to the ten steps of the Joint Commission model of the monitoring and evaluation process. It is critical that research result in specific actions to improve care, along with follow-up monitoring and, when necessary, follow-up action.

Academic Medical Centers↗
PubMed1991

The pneuPAC hyperbaric variant HB: a ventilator suitable for use within a one-man hyperbaric chamber.

We describe the performance of the pneuPAC hyperbaric variant HB, a ventilator designed for use in a one-man hyperbaric chamber. The ventilator delivered minute volumes of 11-23 litre at 1 atm abs to 7.6-16 litre at 2.5 atm abs. The delivered minute volume may be controlled easily from outside the chamber by manipulation of the ventilator rate, 11.5-31 b.p.m.

Evaluation Studies as Topic↗