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Biomedical subjects

S Parker

Publications and source records attributed to S Parker.

At least 127 records · Page 7Linked to original sources
PubMed1993

Application of denaturing gradient gel electrophoresis to detect DNA sequence differences encoding apolipoprotein E isoforms.

Apolipoprotein E (apoE) plays an important role in plasma lipid metabolism. Three common isoforms of this protein have been identified by the isoelectric focusing method. In this report we describe a new method for distinguishing these isoforms. Our method employs PCR amplification of the DNA sequence of exon 4 in the apoE gene followed by denaturing gradient gel electrophoresis (DGGE) to distinguish its different melting characteristics. Identification of the ApoE isoforms through DNA melting behavior rather than protein charge differences eliminates the problems associated with isoelectric focusing and facilitates screening for additional mutations at the apoE locus.

Apolipoproteins E↗
PubMed1993

Maternal prevalence of Toxoplasma antibody based on anonymous neonatal serosurvey: a geographical analysis.

A total of 12,902 neonatal samples collected on absorbent paper for routine metabolic screening were tested anonymously for antibodies to toxoplasma. Seroprevalence varied from 19.5% in inner London, to 11.6% in suburban London, and 7.6% in non-metropolitan districts. Much of this variation appeared to be associated with the proportions of livebirths in each district to women born outside the UK. However, additional geographical variation remained and seroprevalence in UK-born women was estimated to be 12.7% in inner London, 7.5% in suburban London, and 5.5% in non-metropolitan areas. These estimates are considerably lower than any previously reported in antenatal sera in the UK. The wide geographical variation highlights a need for further research to determine the relative importance of different routes of transmission.

Antibodies, Protozoan↗
PubMed1993

Accreditation in nursing education. An explanation.

It has long been recognised that the provision of continuing education for nurses, midwives and health visitors is often ineffective and sporadic in its delivery. Some courses are recorded with the National Board but others, often of equal value, are merely statements of attendance or 'in-house' courses with no formal assessment, repeated at the same level and on different courses, creating repetition and failing to maximise opportunities for career development. In addition, no recognition of expertise gained in the workplace has been considered. Many practitioners have, as a result, felt devaluated when their years of practice are granted no formal recognition.

Accreditation↗
PubMed1992

Cost effectiveness of once-daily oral antimicrobial therapy.

Once daily dosing of oral antimicrobials achieves significantly better patient compliance than three or four times daily dosing, and limited data suggest that this is associated with greater efficacy. Comparison of once daily and twice daily dosing is less consistent, and most studies show only marginally better compliance with once daily dosing versus twice daily dosing. Detection of urinary antimicrobial activity provides a simple method for checking compliance with oral antimicrobials and deserves wider study. Counts of residual tablets have been shown to overestimate compliance. Intravenous formulations are always more expensive than equivalent oral formulations, and preparation and administration of intravenous drugs adds significant additional costs. Moreover, intravenous regimens are complex, and a number of studies have shown that serious errors occur in both preparation and administration of intravenous drugs. There is increasing evidence that serious infections can be adequately treated with oral drugs, and the excellent bioavailability of quinolones makes them particularly attractive for these indications. Clinicians require a method for checking absorption by patients with severe infection, and the Serum Bactericidal Test may provide a practical method for monitoring a wide variety of drugs.

Administration, Oral↗
PubMed1992

Reinforcement of polymers of 2,2 bis-4(2-hydroxy-3-methacryloyloxy propoxy) phenyl propane by ultra-high modulus polyethylene fibres.

A study has been made of the reinforcement of 2,2 bis-4(2 hydroxy-3-methacryloyloxy propoxy) phenyl propane/tetra-hydrofurfuryl methacrylate copolymers with ultra-high modulus polyethylene fibres. The fibres were orientated longitudinally, in loadings up to 50% w/w, and both untreated and surface treated fibres were studied. Modulii up to approximately 35 GPa were achieved in the axial direction, and the specimens could not be broken in the simple flexure test employed. Electron microscopy of fractured specimens showed extremely good contact between resin and fibre. No deterioration in properties was observed over 6 months in water.

Biocompatible Materials↗
PubMed1992

Clonal diversity of methicillin-resistant Staphylococcus aureus in an acute-care institution.

OBJECTIVE: To evaluate plasmid and chromosomal typing methods for differentiation of methicillin-resistant Staphylococcus aureus (MRSA). DESIGN: Comparison of relatedness of strains using epidemiologic features, phage typing, and antimicrobial susceptibility with blinded assessment by molecular typing methods. Molecular typing methods included AccI and ClaI restriction endonuclease fingerprinting of chromosomal DNA and plasmid typing. SETTING: Tertiary-care teaching hospital. METHODS: Convenience sample of 10 MRSA strains, including 4 outbreak-associated and 6 sporadic strains of diverse epidemiologic origins without evidence of nosocomial transmission. RESULTS: Only 2 strains were phage typeable. The epidemic strain was distinguishable by its susceptibility pattern. The other strains were not consistently separable by phenotyping or plasmid typing methods but were distinct by chromosome typing. CONCLUSIONS: These observations document the diversity of origins of MRSA strains introduced into an acute-care institution. Chromosomal typing may be the preferred method for the determination of clonal origin of MRSA.

Bacterial Typing Techniques↗
PubMed1992

Epidural versus general anesthesia, ambient operating room temperature, and patient age as predictors of inadvertent hypothermia.

To elucidate the multifactorial nature of perioperative changes in body temperature, the influence of several clinical variables, including anesthetic technique, ambient operating room temperature, and age, were evaluated. Perioperative oral sublingual temperatures were measured in 97 patients undergoing lower extremity vascular surgery randomized to receive either general (GA) or epidural (EA) anesthesia. Surgery and anesthesia were performed in operating rooms (OR) with a relatively warm mean ambient temperature (24.5 +/- 0.4 degrees C) (GA, n = 30; EA, n = 33) or relatively cold mean ambient temperature (21.3 +/- 0.3 degrees C) (GA, n = 21; EA, n = 13). Patients were 35-94 yr old, with a mean age of 64.5 +/- 1.1 yr. A regression analysis was performed to determine the variables that correlated with intraoperative decrease in temperature and postoperative rewarming rate. The major correlates of greater intraoperative decrease in temperature were 1) GA (P = 0.003); 2) cold ambient OR temperature (P = 0.07); and 3) advancing patient age (P = 0.03). There was significant interaction between ambient OR temperature and type of anesthesia (P = 0.03): there was a greater intraoperative decrease in temperature with GA compared to EA in a cold OR but a similar decrease with GA and EA in a warm OR. The data also suggest an interaction between type of anesthesia and patient age (P = 0.06), showing a greater decrease in temperature with GA compared to EA in the younger patients, but a similar decrease between GA and EA in older patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1992

Two methods for assessing the risk-factor composition of the HIV-1 epidemic in heterosexual women: southeast England, 1988-1991.

OBJECTIVE: The prevalence of HIV-1 in the heterosexual population in southeast England between 1988 and 1991 was examined using two methods. DESIGN AND METHODS: First, district neonatal seroprevalence was compared on a geographical basis to social and demographic variables reflecting risk-factor prevalence. Second, over the same period eight children who developed AIDS within the first 12 months of life were born. RESULTS: The differences in seroprevalence between districts could be explained by the proportion of livebirths to women born in parts of Africa. An estimated 92% of neonatal seropositives could be associated with this demographic variable. The proportions of livebirths to women born in other countries, the prevalence of notified injecting drug use, and area measures of social deprivation, were only poorly related to HIV seroprevalence, and had no additional explanatory value. Seven of the eight (87.5%) children who developed AIDS in the first year were born to black women from Africa. CONCLUSIONS: Both methods suggest that a high proportion of heterosexually transmitted HIV in southeast England has been imported.

Adult↗
PubMed1992

Nocturnal nasal IPPV stabilizes patients with cystic fibrosis and hypercapnic respiratory failure.

Nocturnal nasal intermittent positive pressure ventilation (nIPPV) has been used successfully in the management of patients with respiratory failure due to chest wall deformity and neuromuscular disease. In order to determine if nIPPV is useful in patients with cystic fibrosis (CF) complicated by respiratory failure, we treated four hypercapnic patients for up to 18 months. All patients had failed to respond to intensive conventional therapy, including nocturnal nasal CPAP in three of the patients. Within a few days of commencing nIPPV, all reported improved length and quality of sleep. There was lessening of the degree of hypercapnia and an increase in respiratory muscle strength. After stabilization in the hospital, all patients were able to be discharged home receiving nocturnal assisted ventilation. The improvements seen in these patients have been maintained for up to 18 months. We believe nIPPV offers an effective therapeutic approach for patients with end-stage CF in hypercapnic respiratory failure and may be particularly advantageous for those awaiting heart-lung transplant.

Adult↗
PubMed1992

Comparing the effects of neonatal intensive care unit intervention on premature infants at different weights.

This study investigated the efficacy of an intervention program in the neonatal intensive care unit (NICU) on the development of premature infants from low socioeconomic status (SES) backgrounds. Sixty premature infants born at a county hospital over an 8-month period and their mothers were the focus of this study. The infants were assigned to either a control group or an experimental group. The experimental group received teaching and reinforcement about their babies' behavior from a child development specialist when they visited the NICU. Of the initial 60 infants, 49 completed the study at 8 months, but because data from only the first born of twin pairs were used, 41 infants were included in the final analysis. Infants were divided into two weight groups: one below and one above 1500 g. There was a significant effect of the intervention on the infants' mental and motor scores at 4 and 8 months. Significant differences on the total Home Observation for Measurement of the Environment (HOME) were noted between the groups. There were some significant differences between intervention and control groups on the interaction of the mother with the infant at 4 months but not in the play situation at 8 months. The lighter premature infants had a greater boost from the intervention than did the heavier premature infants. The intervention had no effect on the mother's perception of her infant's temperament or on her confidence skills. In line with other research findings, the infants who weighed less than 1500 g seemed to have benefited most from the intervention, and the effect of the intervention was most notable at 4 months.(ABSTRACT TRUNCATED AT 250 WORDS)

Child, Preschool↗
PubMed1992

Quantitative estimation of human uterine artery blood flow and pelvic blood flow redistribution in pregnancy.

OBJECTIVE: To determine the contributions of uterine artery diameter and mean flow velocity to the increase in volumetric flow during human pregnancy. METHODS: Volunteers (18 pregnant and six not pregnant) were studied using both a commercially available Doppler instrument with imaging ultrasound and an improved Doppler instrument with software that can determine instantaneous true mean blood flow velocity. Diameter and mean flow velocity measurements were combined to yield volumetric flows in the common iliac, external iliac, and uterine arteries during and after pregnancy. RESULTS: Compared with the nonpregnant state, uterine artery diameter doubled by week 21 (from 1.4 +/- 0.1 to 2.8 +/- 0.2 mm; P < .05), did not change between weeks 21 and 30 (2.9 +/- 0.1 mm), and increased between weeks 30 and 36 (to 3.4 +/- 0.2 mm). Uterine artery mean flow velocity rose progressively from nonpregnant values to attain at week 36 a velocity nearly eight times faster (8.4 +/- 2.2 versus 61.4 +/- 3.0 cm/second; P < .05). Unilateral uterine artery blood flow at week 36 was 312 +/- 22 mL/minute. CONCLUSIONS: Compared with nonpregnant values, common iliac artery flow increased and external iliac artery flow decreased during pregnancy, suggesting that redistribution of pelvic flow to favor the uterus contributed to the pregnancy-associated rise in uterus artery flow. Early in pregnancy, the increase in uterine artery blood flow was due in equal parts to changes in uterine artery diameter and mean flow velocity, whereas late in pregnancy, the rise was due mainly to faster mean flow velocity.

Adult↗
PubMed1992

Changing trends in approach to wheezy children by family doctors.

The prevalence of asthma in children appears to have increased dramatically over the past 20 years. There is evidence that some of this increase is due to earlier recognition and relabeling of symptoms such as wheeze. In this study we set out to see if increased awareness of the presentation of asthma in young children has led to earlier diagnosis by family doctors and a decrease in the number of courses of antibiotics given before the introduction of bronchodilators. The family doctor records of 769 children aged 0-5 years were examined retrospectively by an independent paediatrician. One third had at least one documented episode of wheeze and the prevalence of asthma was 10.5%. The mean age of diagnosis was 2.59 years although the mean age at which bronchodilators were introduced was 2.22 years. 22 children, who were never recorded as being asthmatic, were nevertheless appropriately treated with bronchodilators.

Age Factors↗
PubMed1991

Prevalence of maternal HIV-1 infection in Thames regions: results from anonymous unlinked neonatal testing.

To monitor the spread of human immunodeficiency virus (HIV) in the heterosexual population, residues of blood samples collected routinely on absorbent paper for neonatal screening (Guthrie cards) in NE, NW, and SW Thames Regions in England have been tested for antibodies to HIV-1 since June, 1988. 323,369 dried blood spots were analysed to end March, 1991. Prevalence of anti-HIV-1 in newborn babies has remained stable in outer London and non-metropolitan districts whereas prevalence in inner London has increased from 1 in 2000 in the 12 months beginning June, 1988, to 1 in 500 in the first 3 months of 1991. Either exponential or linear growth in the numbers of new seropositives could account for the results. That obstetricians were aware of maternal HIV infection in only 20% of infected pregnancies, indicates the extent to which HIV infection goes unrecognised in the heterosexual community.

Confidentiality↗
PubMed1991

Phorbol esters down-regulate transcription and translation of the CD4 gene.

This study investigated the effects of PMA on biosynthesis and transcription of the CD4 molecule and gene in order to define mechanisms resulting in reduced cell surface expression of the CD4 molecule after treatment with PMA. Cells treated with PMA showed reduced biosynthesis of the CD4 molecule but not of class I HLA molecules. Furthermore, PMA treatment resulted in reduced steady-state levels of CD4 mRNA and inhibition of the relative rate of transcription of the CD4 gene. Cells expressing transfected CD4 cDNA gene products modulated in response to PMA, however, re-expressed CD4 earlier than cells expressing the product of the wild-type CD4 gene. These data suggest that the cell surface expression of the CD4 molecule is probably down-regulated at the level of the protein, as well as the gene, and that inhibition of transcription may affect the kinetics of CD4 expression. These observations provide further insight into the mechanisms by which HIV affects expression of CD4.

Actins↗