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Biomedical subjects

A Wright

Publications and source records attributed to A Wright.

At least 181 records · Page 10Linked to original sources
PubMed1996

Early divergent lung antioxidant enzyme expression in response to lipopolysaccharide.

Lipopolysaccharide (LPS), a component of the cell wall of Gram-negative bacteria, interacts with eukaryotic cells, causing changes in gene expression and a rapid increase in the formation of superoxide and H2O2. We now report that, within 6 h of treating rats with LPS, there was a divergent response in the lung of manganese superoxide dismutase (Mn-SOD) and catalase expression without a change in expression of copper-zinc superoxide dismutase or glutathione peroxidase. The activity and mRNA concentration of Mn-SOD increased during the time catalase mRNA concentration and activity decreased. These divergent changes and activation of nuclear factor-kappa B (NF-kappa B) were preceded by a fall, 1 h after LPS treatment, in the RNA binding activity of two redox-sensitive proteins: Mn-SOD RNA binding protein and catalase RNA binding protein. The rapid onset of these changes, the bacteriostatic properties of H2O2, and the signaling function of NF-kappa B suggest that the divergent expression of Mn-SOD and catalase is a coordinated component of the acute phase reaction to bacterial invasion.

Animals↗
PubMed1996

Changing hospital practices to increase the duration of breastfeeding.

OBJECTIVE: To change the breastfeeding policy in a university teaching hospital in accord with the Ten Steps to Successful Breastfeeding of the United Nations Children's Fund and World Health Organization and to assess the impact of hospital practices on the duration of breastfeeding. METHODS: One hundred ninety-two and 392 postpartum women in a maternity ward were interviewed in 1990 and 1993, respectively, regarding how they were feeding their infants and feeding practices in the hospital. Between these two periods, the hospital infant-feeding policy was reviewed and revised in accord with the Ten Steps. Two hundred seventy of the mothers interviewed in 1993 were interviewed again when their infants were 4 months old regarding the duration of full and partial breastfeeding. RESULTS: By 1993, more newborns were put to the breast in the first hour of life (63.2% vs 24.8%); fewer breastfed infants were fed foods other than breast milk (27.9% vs 46.7%); and more mothers received breastfeeding guidance from hospital staff (81.9% vs 61.3%). The duration of breastfeeding in 1993 was longer for women who did not receive formula in the hospital, who were not given discharge packs containing formula and/or coupons, and who roomed-in more than 60% of the time. These associations persisted after controlling for confounding. CONCLUSION: Infant-feeding policies and practices are amenable to change, and policies such as the Baby-Friendly Hospital Initiative may contribute to an increase in the duration of breastfeeding.

Adult↗
PubMed1996

Nurses' perceptions of the value of nursing research for practice.

Nurses' perceptions of whether nursing research is a valuable guide for clinical practice were investigated by a questionnaire survey. The non-random sample of 410 medical-surgical and psychiatric nurses working in hospitals and community mental health centres were also asked whether they applied research findings to their practice, and whether they participated in research and read nursing research journals. The study found that most nurses believed that nursing research is important for advancing clinical care but few applied research findings to their practice, participated in research or regularly read research journals. There were no significant differences in the value attributed to research by nurses from different educational backgrounds or different clinical settings. In the respondents' opinion, their education in nursing research was well covered in 16% of basic hospital courses and 56% of tertiary courses.

Adult↗
PubMed1995

A high-resolution linkage map of the lethal spotting locus: a mouse model for Hirschsprung disease.

Mice homozygous for the lethal spotting (ls) mutation exhibit aganglionic megacolon and a white spotted coat owing to a lack of neural crest-derived enteric ganglia and melanocytes. The ls mutation disrupts the migration, differentiation, or survival of these neural crest lineages during mammalian development. A human congenital disorder, Hirschsprung disease (HSCR), is also characterized by aganglionic megacolon of the distal bowel and can be accompanied by hypopigmentation of the skin. HSCR has been attributed to multiple loci acting independently or in combination. The ls mouse serves as one animal model for HSCR, and the ls gene may represent one of the loci responsible for some cases of HSCR in humans. This study uses 753 N2 progeny from a combination of three intersubspecific backcrosses to define the molecular genetic linkage map of the ls region and to provide resources necessary for positional cloning. Similar to some cases of HSCR, the ls mutation acts semidominantly, its phenotypic effects dependent upon the presence of modifier genes segregating in the crosses. We have now localized the ls mutation to a 0.8-cM region between the D2Mit113 and D2Mit73/D2Mit174 loci. Three genes, endothelin-3 (Edn3), guanine nucleotide-binding protein alpha-stimulating polypeptide 1 (Gnas), and phosphoenolpyruvate carboxykinase (Pck1) were assessed as candidates for the ls mutation. Only Edn3 and Gnas did not recombine with the ls mutation. Mutational analysis of the Edn3 and Gnas genes will determine whether either gene is responsible for the neural crest deficiencies observed in ls/ls mice.

Animals↗
PubMed1995

Glycosylation of the variable region of immunoglobulin G--site specific maturation of the sugar chains.

The structure of the N-linked sugar chains attached to three IgG antibodies, identical in amino acid sequence except for the changes required to introduce the carbohydrate addition sites, has been determined. All three antibodies are specific for dextran but differ in their ability to bind antigen. The heavy chains with a murine variable region (V region) attached to the human gamma 4 constant region were expressed in a murine hybridoma synthesizing the specific light chain. In addition to the glycosylation site in the Fc portion, each antibody has a different glycosylation site in the second complementarity determining region (CDR2) of the heavy chain (Asn54, Asn58, or Asn60). The sugar chains were released from purified Fab and Fc fragments by hydrazinolysis and converted to radioactive oligosaccharides by reduction with sodium borotritide. The structures of these radioactive oligosaccharides were determined by a combination of sequential exoglycosidase digestion and Bio-Gel P-4 and lectin column chromatography. For all three antibodies, the carbohydrate attached to the Fc portion was a mixture of complex-type biantennary sugar chains. The variable region carbohydrate structures attached at Asn54 and Asn58 were also complex-type but more highly sialylated than were the Fc-associated sugars. Moreover, unlike the Fc-associated sugars, a significant population of Fab-associated sugars contained a Gal alpha 1-->3 residue as a non-reducing terminus. In contrast, the carbohydrate attached at Asn60 was a high mannose structure. These results demonstrate that slight changes in the position of carbohydrate attachment within CDR2 of the variable region of the heavy chain can substantially alter carbohydrate processing and that complex-type carbohydrates contained within the same polypeptide chain can have different structures.

Amino Acid Sequence↗
PubMed1995

Community-acquired infections among children in an urban environment: a 2-year prospective study in Liverpool, U.K.

Community-acquired infections are an important cause of admission of children to hospital. We have made a 2-year prospective study of 1,599 children admitted with infection to the Royal Liverpool Children's Hospital in order to determine the pattern of infections, their seasonal distribution and the role of the laboratory in isolating causative agents. Respiratory infections (32% cases) and gastroenteritis (28% cases) were the principal causes of admission. Of all admissions, 64% were children aged less than 1 year. Appropriate specimens were obtained and/or investigations made of 48% cases. Overall, a causative agent was determined in 21% cases. Individual pathogens showed marked seasonality. Respiratory syncytial virus, rotavirus and Shigella species were found more often in the winter months, while Salmonella species and adenovirus infections were most common in the summer. The results provide local data that is relevant to both public health and hospital planning. They also emphasise the need for continuing surveillance of community-acquired infections.

Child, Preschool↗
PubMed1995

Hypoalgesia post-manipulative therapy: a review of a potential neurophysiological mechanism.

This article provides a review of the available scientific evidence related to the structure and function of descending pain inhibitory systems projecting from the periaqueductal gray region to the spinal cord. The importance of these systems in the phenomenon of endogenous analgesia is discussed. The theory that the initial pain-relieving effect of manual therapy procedures may involve activation of these control systems is proposed and a series of hypotheses based on this theoretical concept are presented. Recent studies evaluating the effects of spinal mobilisation procedures are outlined and the outcomes of these studies are discussed in relation to theoretical role of descending pain inhibitory systems in manipulation-induced analgesia. Directions for further research in this area are considered.

Journal Article↗
PubMed1995

Effects of a novel manipulative physiotherapy technique on tennis elbow: a single case study.

A single case study design was used to investigate the effect of a novel manipulative physiotherapy technique on the pain and dysfunction which characterises tennis elbow. The technique involves the physiotherapist sustaining a lateral glide of the elbow while the patient performs an activity which usually aggravates pain. To be judged successful, the technique should abolish pain. A pain visual analogue scale (VAS) and pressure algometer were used to measure pain. Function was measured with a grip dynamometer, function VAS and pain-free function questionnaire. The study involved three phases in a ABC design. They were a 2-week pre-treatment assessment phase, a 2-week treatment phase and a 6-week post-treatment assessment phase. The patient received four treatment sessions over the treatment phase. The technique's effect was to reduce pain and increase function during and immediately after its application. Improvement in pain and function as measured by VASs was correlated (r = -0.92, p < 0.0001). The rate of pain reduction was greater than that for improvement in function. Although the single case study design limits generalisation of the results, it does provide evidence of the beneficial response obtained by use of this technique in patients affected by tennis elbow.

Journal Article↗
PubMed1995

Polyneuropathy associated with nerve angiomatosis and multiple soft tissue tumors. A newly recognized syndrome.

We report the case of a 33-year-old woman affected by a severe sensorimotor polyneuropathy and multiple soft tissue tumors since childhood. In the biopsied sural nerve, there was a striking vascular proliferation of small vessels. Three subcutaneous nodules were biopsied and disclosed pathologic findings resembling those found in tumors in infantile myofibromatosis. One of the three biopsied subcutaneous nodules was intimately contiguous with a peripheral nerve. The ultrastructural features and immunohistochemical reactivity of the soft tissue tumors and the vessels proliferating in the nerve suggested a common cellular differentiation. The finding of a diffuse polyneuropathy associated with widespread angiomatosis in nerve and multiple soft tissue tumors suggests that these are not coincidental findings, but a manifestation of a syndrome perhaps not previously recognized.

Adult↗
PubMed1995

Protein Hpn: cloning and characterization of a histidine-rich metal-binding polypeptide in Helicobacter pylori and Helicobacter mustelae.

Helicobacter pylori is a human gastrointestinal pathogen involved in gastritis, duodenal ulcers, and gastric neoplasia. This microorganism produces large amounts of a urease which, like all known ureases, has nickel in the active site. We have identified a protein in clinical isolates of H. pylori and an identical protein in the ferret pathogen Helicobacter mustelae that strongly binds Ni2+ and Zn2+. This protein has been named Hpn to emphasize its origins in H. pylori and its affinity for nickel. The encoding hpn gene, cloned and expressed in Escherichia coli ER1793, has an open reading frame (180 bp) that specifies a protein with a calculated molecular mass of 7,077 Da and with the same amino-terminal sequence as that of wild-type Hpn. The deduced sequence of Hpn consists of 60 amino acids, of which 28 (47%) are histidines. The hpn gene does not map with the urease gene cluster on the H. pylori chromosome. An Hpn-negative, isogenic H. pylori strain, generated by hpn gene deletion and grown on blood agar, had the same urease activity that wild-type cells did. Thus, the role of Hpn in helicobacters is unknown.

Amino Acid Sequence↗
PubMed1995

Mental health services: critical component of integrated primary care and substance abuse treatment.

The documented high incidence of mental health disorders among individuals in substance abuse treatment argues for the importance of studying the provision of mental health services to this population. This survey documents how the Linkage Programs assembled an array of mental health services based on the assessed health care needs of clients. Specialty and nonspecialty personnel addressed the extensive mental health needs of ethnically diverse, multiproblem clients with substance abuse problems. The innovative use of nonconventional providers, however, did not eliminate the shortfall between the number of clients with mental health problems and the number who were referred to and received mental health services; nor did it enable all Linkage Programs to address the mental health needs of the most severely ill clients. There is a continuing need to forge relationships between mental health providers and integrated providers of primary care and substance abuse treatment.

Community Mental Health Services↗