Search PubMed⌕ Search

Biomedical subjects

N Jones

Publications and source records attributed to N Jones.

At least 145 records · Page 8Linked to original sources
PubMed1997

Convection warmers--not just hot air.

We sought to determine whether the forced air convection warmers (nine Bair Huggers, Augustine Medical, and one Warm Touch, Mallinkrodt Medical) used in our operating theatres could be a source of microbial pathogens. Agar plates were placed directly in the air stream of the warmers. Four of these grew potentially pathogenic organisms. When the warmers were set to blow through perforated blankets, no growth occurred. Three of the warmers were swabbed and sites of colonisation were found in their hoses. After fixing a microbial filter to the end of the hose, organisms were no longer detectable. We conclude that these warming devices are a potential source of nosocomial infection. They should only be used in conjunction with perforated blankets, should have their microbial filters changed regularly and their hoses sterilised. The inclusion of a microbial filter into the nozzle of the hose could be incorporated into the design of the warmer.

Air Microbiology↗
PubMed1997

Achieving treatment goals for schoolchildren with asthma.

OBJECTIVES: To identify problems in managing asthmatic children in school, which if dealt with would help reduce absenteeism and improve participation in school activities. DESIGN: A survey by questionnaire to headteachers. SETTING: Schools in Merthyr and Rhondda Cynon Taff, South Wales. SUBJECT: Asthmatic schoolchildren in areas studied. MAIN OUTCOME MEASURES: Facilities in schools to manage asthma, headteachers' perceptions of knowledge of asthma management by teachers, possession of written policies, and desire for further training. RESULTS: There are 216 schools in the area studied, with 55,166 schoolchildren. A total of 191 (88%) headteachers returned the completed questionnaire. Five hundred and twenty seven (17%) children were reported absent from school during one term because of asthma, with an average of nine days of schooling lost per asthmatic child per term (range 2-16 days). Only 76 (40%) schools allowed children to be responsible for their inhalers, and 12 (6%) schools required parents to administer inhalers. In 115 (60%) schools, headteachers believed their staff were familiar with the management of asthma. A total of 174 (91%) headteachers expressed interest in further training. CONCLUSION: This study highlights the need to train teachers and provide an agreed joint education and health policy on managing asthma in school.

Absenteeism↗
PubMed1997

A genomewide linkage study of preeclampsia/eclampsia reveals evidence for a candidate region on 4q.

Preeclampsia (PE) and eclampsia (E) are potentially life-threatening conditions that can occur during human pregnancy. Generally considered to be different degrees of severity of the same disease process, the PE/E syndrome is thought to be predominantly genetic in origin, although its exact etiology and genetics are not fully understood. Here we report results of a genomewide linkage search for the gene(s) responsible for susceptibility to PE/E, using 15 informative pedigrees and 90 polymorphic DNA markers from all autosomes. Because of uncertainties concerning inheritance and diagnosis, four different models that assume maternal gene expression have been used to carry out LOD-score analysis. The region between D4S450 and D4S610 (2.8 cM) on the long arm of chromosome 4 was identified as a strong candidate region for a PE/E-susceptibility locus. The maximum multipoint LOD score within this interval was 2.9. Analysis of markers in the region around D4S450 and D4S610 by the affected-pedigree-member method also supported the possibility of a susceptibility locus in this region. However, to verify or exclude definitively linkage to this region, other groups of PE/E pedigrees will be required.

Australia↗
PubMed1996

The Atf1 transcription factor is a target for the Sty1 stress-activated MAP kinase pathway in fission yeast.

The atf1+ gene of Schizosaccharomyces pombe encodes a bZIP transcription factor with strong homology to the mammalian factor ATF-2. ATF-2 is regulated through phosphorylation in mammalian cells by the stress-activated mitogen-activated protein (MAP) kinases SAPK/JNK and p38. We show here that the fission yeast Atf1 factor is also regulated by a stress-activated kinase, Sty1. The Sty1 kinase is stimulated by a variety of different stress conditions including osmotic and oxidative stress and heat shock. Deletion of the atf1+ gene results in many, but not all, of the phenotypes associated with loss of Sty1, including sensitivity to environmental stress and inability to undergo sexual conjugation. Furthermore, we identify a number of target genes that are induced rapidly in a manner dependent upon both the Sty1 kinase and the Atf1 transcription factor. These genes include gpd1+, which is important for the response of cells to osmotic stress, the catalase gene lambda important for cells to combat oxidative stress, and pyp2+, which encodes a tyrosine-specific MAP kinase phosphatase. Induction of Pyp2 by Atf1 is direct in that it does not require de novo protein synthesis and results in a negative feedback loop that serves to control signaling through the Sty1/Wis1 pathway. We show that Atf1 associates stably and is phosphorylated by the Sty1 kinase in vitro. Taken together, these results indicate that the interaction between AM and Sty1 is direct. These findings highlight a remarkable level of conservation in transcriptional control by stress-activated MAP kinase pathways between fission yeast and mammalian cells.

Activating Transcription Factor 1↗
PubMed1996

Analysis of voice outcomes in pediatric patients following surgical procedures for laryngotracheal stenosis.

OBJECTIVE: To evaluate long-term (> 2 years) voice function and corresponding anatomical features in children who have undergone augmentation procedures for laryngotracheal stenosis. DESIGN: Follow-up survey assessment. SETTING: Academic pediatric referral center. PATIENTS OR OTHER PARTICIPANTS: The families of 50 patients were contacted by mail, and completed home questionnaires. Of these 50 patients, 33 agreed to participate in a comprehensive hospital-based voice assessment, and 28 of these underwent fiberoptic endoscopy. INTERVENTIONS: Hospital-based evaluation and parental questionnaire. MAIN OUTCOME MEASURES: (1) Perceptual voice assessment from taped samples by using the Vocal Profile Analysis protocol performed by 3 speech and language therapists, (2) fiberoptic laryngeal endoscopy assessment performed by 3 otolaryngologists, and (3) parental assessment of voice by questionnaire. The conditions of the patients were categorized by etiology, the degree of stenosis, coexisting laryngeal lesions, and the type of surgical procedure that was done based on a review of medical records. RESULTS: Eight of 33 patients were judged perceptually by using an amended version of the Vocal Profile Analysis scheme to have "normal" voices. In the remaining 25 patients, abnormalities were demonstrated in the parameters, including harshness (52%), whisper (36%), ventricular band phonation (21%), continuity (27%), mean pitch (27%), and falsetto voice (12%). By using endoscopy, 3 of 25 larynges were judged to be anatomically normal. Abnormalities that were found in the other patients included altered vocal fold mobility (42%), abnormal subglottis (38%), supraglottic vibration (31%), and anterior commissure blunting (31%). Supraglottic vibration corresponded with the perceptual judgment "ventricular band phonation type," and was seen in children with glottic insufficiency. Only 12% of parents indicated by questionnaire that deterioration of voice and dissatisfaction with voice function occurred after surgical procedures were performed. CONCLUSIONS: A substantial proportion of children who have undergone laryngotracheal surgical procedures for stenosis demonstrate chronic voice and endoscopic abnormalities. The effects of these surgical procedures and preexisting laryngeal abnormalities on voice continue to be difficult to establish in the pediatric population. Careful management by speech and language therapists who are familiar with such children is essential for optimal voice function.

Adolescent↗
PubMed1996

High-dose melphalan followed by autograft employing non-cryopreserved peripheral blood progenitor cells in children.

High-dose chemotherapy followed by autologous bone marrow transplantation (ABMT) enables dose escalation in the treatment of childhood malignancies. Here we report our experience of using peripheral blood progenitor cells (PBPC) to restore haematopoiesis in five children using a simple cell mobilising regime and non-cryopreservation of the harvests. Cells were mobilised using cyclophosphamide and granulocyte colony stimulating factor. Each patient underwent only two leukaphereses, the product being stored before use at 4 degrees C. Successful autologous PBPC transplantation was achieved with melphalan conditioning chemotherapy and re-infusion of the total progenitor cell product. No colony stimulating factors were administered after transplantation. The median numbers of mononuclear cells collected per patient was 10.0 x 10(8)/kg (range 8.13-19.44) and CFU-GM 57.6 x 10(4)/kg (range 10.4-178.85). All patients subsequently engrafted with the median number of days to a neutrophil count > 0.5 x 10(9)/l being 11 (range 10-16), and to a platelet count > 50 x 10(9)/l being 14 (range 12-31). The median number of in-patient days was only 20 (range 19-30). The median demand for blood was 2 units (range 1-2), and platelets 4 units (range 2-28). Usage of systemic antimicrobials and intravenous feeding was also low. Using this simple strategy, collection and transplantation of autologous progenitor cells can be a straightforward procedure in children. It is possible that this could enable dose escalation in some poor prognosis paediatric tumours.

Adolescent↗
PubMed1996

Spontaneous tendon ruptures in patients on chronic dialysis.

Large tendon rupture is a rare catastrophic occurrence in dialysis patients. Pathogenesis of this has been variably thought to be due to malnutrition, insufficient dialysis, amyloidosis, chronic acidosis, or hyperparathyroidism. We investigated contributory causes and timing of this complication in 44 dialysis patients (42 hemodialysis and two peritoneal dialysis patients). Five cases were our own; the other 39 were reported in the literature during the last two decades. Data were compared with a hospital database of 916 patients. The patients who experienced tendon ruptures had been on dialysis longer (mean duration, 7.6 years v 4.0 years; P = 0.001), were younger (mean age, 39.7 years v 48.4 years; P = 0.0001), had much higher parathyroid hormone levels (1,802 pg/mL v 202 pg/mL; P = 0.0001), had a higher phosphate level (6.8 mg/dL v 5.9 mg/dL; P = 0.001), had a slightly higher calcium level (9.2 mg/dL v 8.8 mg/dL; P = 0.038), and had a higher alkaline phosphatase level (649 IU/L v 109 IU/L; P = 0.0001) than control patients. Patients with tendon ruptures had no evidence of malnutrition (albumin 3.7 g/dL v 3.8 g/dL; P = 0.237) and had the same acidosis (bicarbonate 22.2 mEq/L v 22.0 mEq/L; P = 0.180). The time on dialysis to rupture was inversely related to the patient's age (r = 0.47, P = 0.004). Most patients had evidence of years of poorly controlled hyperparathyroidism with high and increasing levels of parathyroid hormone and alkaline phosphatase. Previous steroid use was also much more common in patients with tendon ruptures, as was radiographic evidence of osteitis fibrosa. The disease led to long hospitalization and prolonged morbidity, with mobility limitations in several patients. Spontaneous large tendon rupture in patients is secondary to hyperparathyroidism; is more common in young patients, particularly if exposed to corticosteroids; leads to long-lasting morbidity; and should be preventable by better supervision and treatment of hyperparathyroidism.

Adult↗
PubMed1996

Striving to prevent falls in an acute care setting--action to enhance quality.

Although most falls do not result in serious physical injury, they can contribute to a loss of confidence and mobility which can culminate in a significant reduction in quality of life. Furthermore, the potential to fall is often increased when an individual is institutionalized because of frailty or confusion. The purpose of the study was, therefore, to establish whether a structured intervention would assist in preventing falls in an acute setting. This pre-test/post-test study was carried out over a 12-month period. Interventions included risk assessment, an alert system, reinforcing preventive actions, staff education and ongoing audits and feedback. Initial analysis of the data and comparison of fall rates indicated a significant reduction in the rate of falls between the pre- and post-intervention phases, although subsequent statistical analysis did not identify any significant relationships. It must be noted that no controls existed for extraneous variables, although patient profiles varied minimally during the period of the study. Outcomes include: a reduction in fall numbers and rates, enhanced staff morale with ownership of the programme, provision of a learning experience for staff (on which to build), and the fostering of a professional approach to improving the quality of patient care.

Accidental Falls↗
PubMed1996

Efficient lysis of human immunodeficiency virus type 1-infected cells by cytotoxic T lymphocytes.

Numerous studies of human immunodeficiency virus type 1 (HIV-1)-specific cytotoxic T lymphocytes (CTL) have examined their ability to recognize B-cell lines expressing recombinant HIV-1 proteins, but relatively few data regarding the lysis of HIV-1-infected cells by CTL are available. We studied the ability of HIV-1-specific CTL clones of defined epitope specificity and HLA restriction to lyse infected CD4+ cells at serial time points following infection. CD4+ cell lines were acutely infected with HIV-1 IIIB at a high multiplicity of infection, and the kinetics of cell lysis were examined and compared with the kinetics of viral replication. Intracellular HIV-1 p24 expression was detected by 1 to 2 days after infection, reaching over 98% positive cells by day 4. Recognition of the infected cells by HLA A2- and B14-restricted CTL clones closely paralleled intracellular p24 expression and preceded peak virion production. The maximal levels of lysis with Gag-, reverse transcriptase-, and envelope-specific clones were different, however. The Gag- and envelope-specific clones lysed infected cells at levels equivalent to peptide-sensitized controls, whereas lysis by the reverse transcriptase-specific clones plateaued at a lower level. Peptide titration curves indicated that this effect was not due to differences in sensitivity to the cognate epitopes for the different clones. Although HIV-1 infection induced an approximately 50% decrease in class I HLA expression on the surface of infected cells, lysis by CTL clones was unaffected. These studies indicate that HIV-1-specific CTL can efficiently lyse HIV-1-infected CD4+ cells and suggest that the partial downregulation of class I molecules in infected cells does not significantly affect recognition by CTL.

Acquired Immunodeficiency Syndrome↗
PubMed1996

Neural tube defects 1974-94--down but not out.

AIMS: To describe accurately the total prevalence of neural tube defects (NTDs) in England and Wales over time, and to provide a benchmark up to 1994. METHODS: National data about NTDs reported as births or terminations are available from 1974-94, but reporting is incomplete. A local register of NTDs covering Oxfordshire/west Berkshire from 1965-94 was used to validate national data for the locality, using the method of capture and recapture, and hence to estimate incompleteness of reporting nationally. RESULTS: National underreporting is consistent at about two thirds of the true number of cases reaching at least the second trimester. The local register is much more complete, but time trends locally and nationally are similar. In England and Wales total prevalence declined from about 34 per 10000 live and stillbirths in 1974 to a plateau of just under 8 per 10000 in the 1990s. CONCLUSIONS: The decline in NTD prevalence is real and seems to have stopped. How this relates to changes in diet or the practice of vitamin supplementation is unknown, and the implications of the plateau are uncertain. OPCS figures of 500 NTDs annually in England and Wales represent about two thirds of the true number of cases.

England↗
PubMed1996

A scale for predicting nonphysiological contributions to pain.

BACKGROUND: Waddell and colleagues have identified a series of nonorganic signs which may appear in low back pain patients. The occurrence of these signs helps predict nonphysiological factors in the etiology of the pain. This study describes the development of the Waddell Equivalency Scale (WES) which elicits comparable information from patients with pain at other sites. METHODS: One hundred fifty patients presenting to a comprehensive pain clinic with low back pain were evaluated by physicians for Waddell signs and by psychologists using the Pain Presentation Inventory (PPI) developed by Psychometric Designs Inc. From three scales of the PPI, correlation, analysis of variance and multiple regression identified a formula which predicted Waddell signs from the PPI. The study was replicated on a new sample of 150 patients with almost identical results. The two samples were combined, again with highly similar results. An interpretive scheme was devised for use of the WES scale. RESULTS: The WES score derived from three scales of the PPI predicts the number of Waddell signs elicited from low back pain patients. Since it comes from a paper-and-pencil test rather than a physical examination, it can be used with patients whose pain locus is other than the back. CONCLUSIONS: Behavioral expectations and treatment plans, à la Waddell, can now be applied to patients with other than low back pain. Clinical application of the WES information over a variety of pain populations will be required to determine the parameters of its usefulness.

Adult↗
PubMed1996

Salivary duct determination in Drosophila: roles of the EGF receptor signalling pathway and the transcription factors fork head and trachealess.

Organogenesis in Drosophila embryos begins at 4-5 hours of development as the expression of organ-specific genes is initiated. The salivary primordium, which occupies the ventral epidermis of parasegment 2, is among the earliest to be defined. It is soon divided into two distinct regions: the more dorsal pregland cells and the more ventral preduct cells. We show that it is the opposing activities of the Drosophila EGF receptor (DER) signaling pathway and the Fork head transcription factor that distinguish these cell types and set up the boundary between them. DER signaling acts ventrally to block fork head expression in the preduct cells, thereby restricting gland identity to the more dorsal cells. Fork head in turn blocks expression of duct-specific genes in the pregland cells, thereby restricting duct identity to the more ventral cells. A third regulatory activity, the Trachealess transcription factor, is also required to establish the identity of the preduct cells, but we show that it acts independently or downstream from the DER:fork head confrontation. In trachealess mutants, subdivision of the salivary primordium occurs normally and the dorsal cells form glands, but the ventral cells are undetermined. We present a model proposing that trachealess is the crucial duct-specific gene that Fork head represses to distinguish pregland from preduct cells.

Animals↗
PubMed1996

Prognosis of bacterial meningitis in children.

We studied the incidence and prognosis of acute neurologic complications in 281 children under 13 years of age with a diagnosis of acute bacterial meningitis. All the patients were examined daily by the same group of neurologists, using a standardized neurological examination. Patients with signs of encephalic lesions, unsatisfactory response to antibiotics or decreased level of consciousness were submitted to brain computer tomography. The overall lethality rate was 20.3% and cases whose causative agent was identified presented a higher lethality rate (23.7%) than those in which the agent was not found. The most important neurological abnormalities were meningeal signs (88.3%) followed by decreased consciousness (47.7%), irritability (35.2%), seizures (22.4%), fontanel bulging (20.6%) and cranial nerve palsy (14.2%). Seizures, cranial nerve palsy and the absence of meningeal signs were related to higher rates of lethality. Diminished consciousness, seizures, subdural effusion, abscess and hydrocephalus were the most important complications, respectively. We can conclude that acute bacterial meningitis continues to be an important health problem in developing countries and that public health measures will be necessary to minimize the impact of sequelae and reduce the mortality rate in children with that pathology.

Child↗
PubMed1995

Schizosaccharomyces pombe atf1+ encodes a transcription factor required for sexual development and entry into stationary phase.

We describe the identification and characterization of a transcription factor encoded by the atf1+ gene of the fission yeast Schizosaccharomyces pombe. The factor Atf1, contains a bZIP domain at its C-terminus with strong homology to members of the ATF/CREB family of mammalian factors and in vitro binds specifically to ATF/CRE recognition sites. Furthermore the ATF-like binding activity detected in extracts from fission yeast cells is entirely lost upon deletion of the atf1+ gene. Upon growth to saturation, fission yeast cells exit the mitotic cycle and enter a G0-like stationary phase. However, on rich medium, entry of atf1- cells into stationary phase is restricted and they rapidly lose viability; this does not occur on minimal medium unless cAMP levels are raised. Thus stationary phase entry appears to be regulated negatively by cAMP and positively by Atf1. atf1- cells are also sterile and this sterility appears to be due to a combination of two defects: first, upon nitrogen starvation the majority of atf1- cells fail to arrest in the G1 phase of the cell cycle and second, the induction of ste11+ expression is lost. Thus expression of ste11+ represents a second example of an event that is negatively regulated by the cAMP pathway and positively regulated by Atf1. Despite their close association however, these two regulatory pathways function independently and Atf1 activity is not directly modulated by cAMP levels or mutations that alter the activity of components of the cAMP signalling pathway. Thus Atf1 is a transcription factor that plays an important role in the response of cells to adverse environmental conditions, which is to exit the mitotic cell cycle and either sexually differentiate or enter a resting state.

Activating Transcription Factor 1↗
PubMed1995

Effects of lesion of the inferior olivary complex in learning of the equilibrium behavior in the young rat during ontogenesis. I. Total lesion of the inferior olive by 3-acetylpyridine.

Young DA/HAN strain rats were submitted to an equilibrium test consisting in maintaining equilibrium upon a rotorod rotating at 10 or 20 rpm. They were either intact or lesioned, the lesion consisting in destruction of the inferior olivary complex (IOC) by 50-95 mg/kg i.p. administration of 3-acetylpyridine (3-AP) at day 15, followed, 2 to 4 h later, by i.p. injection of niacinamide (300 mg/kg). All the 3-AP-treated animals included in this study were completely lesioned, the extent of the lesion being estimated by both the response of the rats to harmaline and histological controls at the end of the experiments. The IOC lesioned rats were either naive (tested at one given day) or trained every day (10 trials per day); among the latters, some were trained before and after the lesion, the others being trained either before or only after. Control rats were submitted to the same training schedule. Both quantitative (time during which the animals maintained the equilibrium upon the rotating rod) and behavioral data (strategy used by the animals to maintain equilibrium) were obtained. The results demonstrate that, compared to those of controls rats, the quantitative and behavioral scores of the IOC lesioned animals were altered. Comparison of naive and trained animals shows that the impairment of the equilibrium behavior is not only due to the ataxia provoked by the IOC lesion but is also due to cognitive deficits. However, prelesion training facilitates the acquisition of a more efficient postlesion equilibrium behavior. From these results, it can be concluded that the olivo-cerebellar pathway is involved in the adaptation of motor behavior to the environmental conditions.

Aging↗