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Biomedical subjects

R Parry

Publications and source records attributed to R Parry.

At least 37 records · Page 2Linked to original sources

Antibody ligation of CD7 leads to association with phosphoinositide 3-kinase and phosphatidylinositol 3,4,5-trisphosphate formation in T lymphocytes.

The CD7 40-kDa glycoprotein is present on a major subset of human T cells and in the presence of phorbol esters mediates an accessory pathway of T cell activation. Hitherto, the intracellular events elicited by CD7 have been ill-defined. This report demonstrates that cross-linking of CD7 results in the formation of phosphatidic acid in the absence of phosphatidylinositol-4,5-bisphosphate metabolism and also the formation of D-3 phosphoinositides lipids which have been postulated to act as intracellular regulatory molecules. The magnitude of D-3 phosphoinositide formation was similar to that induced by CD3. Both the CD7- and CD3-induced elevation of phosphatidylinositol 3,4,5-trisphosphate approximately 5-10 fold less than that elicited by ligation of the costimulatory molecule CD28 by its counter receptor CD80. The formation of D-3 phosphoinositides following ligation of CD7 coincided with the co-association of CD7 with phosphoinositide 3-kinase, the enzyme which mediates the formation of D-3 phosphoinositide lipids. In contrast, ligation of another reported T cell accessory molecule CD5, failed to elicit formation of D-3 phosphoinositides, implying that phosphoinositide 3-kinase is not coupled to all T cell molecules with accessory functions. Since D-3 phosphoinositides have been suggested to play a pivotal role in T cell costimulatory signals induced by CD28, the results presented in this study suggest that CD7 may also influence T cell activation via this pathway.

Androstadienes↗

Chaos under canvas: a Salmonella enteritidis PT 6B outbreak.

An outbreak of Salmonella enteritidis PT 6B food poisoning, the first reported of this recently described phage type, resulted in illness among 46 of 49 members of a camping group in North Wales, 33 of whom were hospitalized. Epidemiological evidence (P < 0.0001) indicated that a lemon meringue pie was the vehicle of infection. Fresh shell eggs, stored after purchase at ambient temperature, appear to be the most likely source of infection, with multiplication during preparation and subsequent storage of the pie a significant contributory factor. Campers may be at greater risk than others and should consider the use of cold boxes for the transport and storage of eggs, and avoid the preparation of lightly cooked egg products under these basic conditions.

Abdominal Pain↗

Case report: spontaneous coronary artery dissection.

Spontaneous coronary artery dissection is a rare cause of ischaemic heart disease occurring most commonly in young women. It is frequently fatal. Our case is unusual in that a very long dissection flap was diagnosed by coronary angiography in a male patient who presented with only minor symptoms. We discuss the pathogenesis of spontaneous dissection and the prognosis for this group of patients.

Adult↗

Angiographic prediction of dissection followed by ischaemic complications during coronary angioplasty.

Ischaemic problems occur in about 8% of coronary angioplasties and are the major cause of morbidity and mortality associated with the procedure. Although the ischaemic event is usually due to acute vessel closure due to vessel dissection, it is noteworthy that 80-90% of radiographically visible dissections cause no problem. We have reviewed 200 consecutive coronary angioplasties in order to find predictive factors for those patients likely to suffer dissection followed by ischaemic complications. Thirty-four (17%) of the patients undergoing coronary angioplasty had radiographically visible dissections, of whom 12 (35%) suffered ischaemic complications. There were 16 (8%) major ischaemic complications following angioplasty. In four of these cases no obvious dissection was visible within the vessel. Eight out of a subgroup of 16 patients who had sequential stenoses along one vessel dilated at angioplasty had a dissection. Six of these eight patients suffered a major ischaemic complication following the dissection. Thus in this group of patients, sequential stenosis not only conferred a high probability of dissection during angioplasty but additionally carried an increased risk of ischaemic complications following the dissection. Awareness of this may affect case selection and may indicate the need for early re-examination of the vessel should problems occur following angioplasty.

Aortic Dissection↗

Transient cortical blindness after coronary angiography.

Transient visual loss lasting three days developed after transfemoral coronary angiography in a 62 year old man. Computed tomography (CT) showed bilateral leakage of contrast medium into the occipital cortex. A repeat CT scan after his sight recovered showed clearance of contrast with no underlying infarction. A breakdown of the blood-brain barrier with direct neurotoxicity of the contrast media seemed to be the cause of these neurological changes after coronary angiography which apparently have not been reported before.

Blindness↗

Molecular medicine: a primer for clinicians. Part IV: Cystic fibrosis and the power and limitations of molecular medicine.

Cystic fibrosis (CF) is among the most common genetic diseases in caucasians of Northern European ancestry. The cloning of the gene responsible for cystic fibrosis, the characterization of the product of the gene and identification of mutations occurring in CF patients are excellent examples of the potential clinical utility of molecular medicine. The ethical issues associated with the ability to identify carriers of CF mutations highlight the magnitude of the questions molecular medicine raises.

Cloning, Molecular↗

Duplex ultrasonography and pulse-generated run-off in selecting claudicants for femoropopliteal angioplasty.

Non-invasive assessment of lower limb vasculature may avoid unnecessary angiography in claudicants. Colour duplex ultrasonography of the femoral and popliteal arteries was performed to assess patency and the presence of any stenoses, and pulse-generated run-off (PGR) was used to assess the distal vasculature. In 65 legs colour duplex scanning was successful, compared with angiography, in identifying the site and type of disease in the femoropopliteal segment and 23 lesions were correctly identified as suitable for angioplasty. More patent distal vessels were demonstrated by PGR than by angiography; no vessels patent on angiography were missed by PGR. The estimated cost of diagnostic angiography was 330 pounds per test compared with 52 pounds for non-invasive assessment. By using duplex examination as a screening test, a potential saving of 8062 pounds could have been made in this series. Duplex ultrasonography offers a non-invasive and cost-effective alternative to diagnostic angiography for clinically suspected infrainguinal arterial disease presenting as claudication. PGR was not of clinical value in assessing suitability for angioplasty.

Aged↗

Alkaline gastroesophageal reflux in infants and children.

The incidence of alkaline gastroesophageal reflux (GER) was examined in 111 consecutive children referred for evaluation of GER during a 1-year period. The results of 24-hour pH monitoring studies and the medical records were retrospectively evaluated. Acid reflux was defined as occurring whenever the pH was less than 4 and alkaline reflux was defined whenever the pH was greater than 7. The percentage of time that reflux occurred, the number of reflux episodes, the number of episodes greater than 5 minutes, and the longest episode were all recorded. Based on these data, four categories of patients were identified as compared with normal values as determined by Pellegrini et al. When using criteria based on the percentage of time that reflux occurred, the largest group of children with GER was found to reflux acid (50%). However, 27 children (24%) had combined acid and alkaline reflux. Eighteen (16%) had predominantly alkaline reflux. Previously, these 18 children would have been considered as having a low likelihood of reflux by pH criteria. Endoscopic examination showed that pathological evidence of esophagitis occurred in four of the children with pure alkaline reflux. This review shows that symptomatic GER in infants and children may be due to acid or alkaline secretions or a mixture of both. A previously unrecognized cohort exists of children who demonstrate primary alkaline reflux. These patients need to be recognized and may benefit from a therapeutic program specifically designed to control alkaline reflux.

Child↗

The effect of alcohol intake on the disposition of diphenhydramine in man.

The disposition of diphenhydramine (DPHA) and its principal metabolites was investigated in two subjects after i.v. and oral dosing. Based on these parameters the results of a multiple oral dose regimen were predicted and compared to the results obtained in these volunteers. During one dose interval of the multiple oral dose regimen, the volunteers indulged in social drinking. Comparison of this interval with a control period showed no differences in disposition. Alcohol therefore, would appear to have no effect on the disposition of DPHA.

Administration, Oral↗

Toronto multiagency child abuse research project: the abused and the abuser.

Information from 422 cases of child mistreatment in Toronto was gathered from the files of a child welfare agency and a children's hospital. These data were compared to patterns reported in previous studies and clinical writings on child mistreatment to investigate similarities and differences in families whose children have been abused in Canada, England, and the United States. Findings from the present study were similar to others in many respects. The differences were primarily in the area of lower incidences of such problems as perinatal difficulties in the children and intellectual limitations and social isolation in the parents; however, there was a higher incidence of single-parent families. The results suggest that clinicians should bear in mind that child mistreatment cannot be ruled out on the grounds that no serious problems have been noted for the child or the family.

Canada↗

Infection and interferon production in systemic juvenile chronic arthritis: a prospective study.

Twenty-four episodes of disease exacerbation in 19 children suffering from systemic juvenile chronic arthritis were studied. Sixteen of these were preceded by an infection (chi 2 = 20.14, p less than 0.001), mostly of the upper respiratory tract. In the 10 cases seen during an infection causative agents were identified in 5 (herpes simplex, rhinovirus, and on 3 occasions streptococcus). The total number of infections was not increased when compared with infection rates predicted by several reported studies. In the absence of clinical infection, specific antibody titres to a panel of microbial antigens were similar to those of a control group but with a trend toward higher titres in patients with hypergammaglobulinaemia. Interferon (IFN) responses were not defective, though sequential in-vitro IFN production from peripheral blood mononuclear cells (PBM) fluctuated considerably in the same patients, occasionally being absent with no obvious clinical correlate. IFN-alpha was induced by stimulation with Newcastle disease virus (NDV), and the mean responses of the patients were significantly greater than those of controls. IFN-gamma production on phytohaemagglutinin (PHA) stimulation was similar in patients and control groups. IFN was not detected in any of the sera from patients or controls.

Adolescent↗