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Biomedical subjects

B Hall

Publications and source records attributed to B Hall.

At least 55 records · Page 3Linked to original sources
PubMed1994

Protein adsorption, lymphocyte adhesion and platelet adhesion/activation on polyurethane ureas is related to hard segment content and composition.

Segmented polyurethane ureas with different hard segment content and composition were synthesized using 4,4'-diphenylmethane diisocyanate and polytetramethylene glycols. Using polyols with different molecular weights, it was possible to synthesize polyurethane ureas with either: (i) a constant ratio of urethane to urea bonds; (ii) a constant urethane content; or (iii) a constant urea content. Bulk properties were assessed by dynamic mechanical analysis. Surface properties were estimated by contact angle measurements and streaming potential measurements. Haemocompatibility was evaluated in vitro by measuring the adsorption of human serum albumin (HSA) and fibrinogen (Fg), the adhesion of human peripheral blood lymphocytes (PBL), and the presence of activated platelets on the biomaterial surfaces. Enzyme immuno assays (EIA) have been specially developed for this purpose for the detection of antibody-recognizable plasma proteins and platelet surface membrane proteins. No simple correlation between chemical structure of the polymers and surface properties was found. Parameters of haemocompatibility correlated more closely with hard segment content and chemical composition than with the surface characteristics of the polymers. Adsorption of plasma proteins, adhesion of lymphocytes and the adhesion/activation of platelets were found to increase with increasing hard segment content of the polyurethane ureas. However, the monoclonal-antibody recognisable fibrinogen and the platelet activation were nearly constant with increasing hard segment content, if the urea content was kept constant.

Adsorption↗
PubMed1994

Efficacy of breathing and coughing exercises in the prevention of pulmonary complications after coronary artery surgery.

One hundred twenty patients undergoing coronary artery surgery completed a randomized controlled study designed to investigate whether prophylactic chest physiotherapy affected the incidence of postoperative pulmonary complications. Group 1 patients received no preoperative or postoperative chest physiotherapy. Group 2 patients received preoperative education and instruction in breathing and coughing exercises and postoperative supervision and assistance in performing the same. These exercises were supervised by a physiotherapist twice per day on the first 2 postoperative days and once per day on the 3rd and 4th postoperative days. Physiotherapy for group 3 patients was the same as for group 2 patients except that patients were seen by a physiotherapist 4 times per day on the first 2 postoperative days and twice per day on the 3rd and 4th postoperative days. Group 2 and 3 patients were instructed to practice breathing and coughing exercises every hour. Overall, an incidence of clinically significant postoperative pulmonary complications of 7.5 percent was demonstrated. In general, these patients demonstrated lower levels of preoperative pulmonary function and very low early postoperative oxygenation compared with those who did not develop pulmonary complications. There was no indication that the incidence or severity of fever, hypoxemia, chest roentgenologic abnormalities or clinically significant postoperative pulmonary complications was different between groups. These results suggest that the necessity for prophylactic chest physiotherapy after routine coronary artery surgery should be reviewed.

Breathing Exercises↗
PubMed1994

Premedication reduces the incidence of systemic reactions during inhalant rush immunotherapy with mixtures of allergenic extracts.

BACKGROUND: Rush immunotherapy, while having many potential benefits, is associated with an increased incidence of systemic reactions. OBJECTIVE: To determine whether pretreatment with medications reduces the rate of systemic reactions during rush immunotherapy and to identify predictors of such reactions if possible. METHODS: We conducted a double-blind, placebo-controlled study of 22 allergic children ages 6 to 18 years who received rush immunotherapy. Active treatment consisted of a combination of H1 and H2 histamine antagonists and a corticosteroid in gelatin capsules given prior to administration of rush immunotherapy whereas placebo patients received lactose. Rush immunotherapy consisted of eight injections of increasing doses of a mixture of allergens to which each patient was skin-reactive over 1 1/2 days. Serial skin tests and peak expiratory flow rate measurements were performed during the procedure. Following the initial series of injections, patients were followed for 8 weeks and had blood drawn at 2-week intervals for measurements of specific IgG and IgE. RESULTS: Systemic reactions were observed in 3 (27%) active and 8 (73%) placebo patients (Fisher's exact test: P = .047). The mean time for systemic reactions was 63 minutes after a previous injection. The most common dose causing a systemic reaction was 0.3 mL of 1:1000 (wt/vol). The best predictors of development of a systemic reaction were degrees of skin sensitivity to the extract before and after premedication. Local reactions were not associated with subsequent systemic reactions. Specific IgG rose by 2 weeks while specific IgE did not change significantly during the 8-week follow-up period. Pretreatment did not change the number of systemic reactions seen with subsequent injections. CONCLUSIONS: Premedication significantly reduces the incidence of systemic reactions during rush immunotherapy and is therefore recommended. Degree of skin sensitivity to the injected extract may eventually prove to be a clinically useful predictor for the development of systemic reactions.

Adolescent↗
PubMed1993

Genetic and physical mapping of the Treacher Collins syndrome locus with respect to loci in the chromosome 5q3 region.

Treacher Collins syndrome is an autosomal dominant, craniofacial developmental disorder, and its locus (TCOF1) has been mapped to chromosome 5q3. To refine the location of the gene within this region, linkage analysis was performed among the TCOF1 locus and 12 loci (IL9, FGFA, GRL, D5S207, D5S210, D5S376, CSF1R, SPARC, D5S119, D5S209, D5S527, FGFR4) in 13 Treacher Collins syndrome families. The highest maximum lod score was obtained between loci TCOF1 and D5S210 (Z = 10.52; theta = 0.02 +/- 0.07). The best order, IL9-GRL-D5S207/D5S210-CSF1R-SPARC-++ +D5S119, and genetic distances among these loci were determined in the 40 CEPH families by multipoint linkage analysis. YAC clones were used to establish the order of loci, centromere-5'GRL3'-D5S207-D5S210-D5S376-CSF1R -SPARC-D5S119-telomere. By combining known physical mapping data with ours, the order of chromosome 5q3 markers is centromere-IL9-FGFA-5'GRL3'-D5S207-D5S210- D5S376-CSF1R-SPARC-D5S119-D5S209- FGFR4-telomere. Based on this order, haplotype analysis suggests that the TCOF1 locus resides distal of CSF1R and proximal to SPARC within a region less than 1 Mb in size.

Base Sequence↗
PubMed1993

An epilepsy needs document.

Services for epilepsy in the UK are poor in quality, fragmentary and poorly organized. We attempt to define and quantify the scope, content and standards of medical, paramedical and nursing services required, from primary health care to specialist centres. This document has been approved by the Joint Epilepsy Council of Great Britain and Ireland, representing all major patient organizations and care providers.

Cross-Sectional Studies↗
PubMed1993

Isolation of a partial candidate gene for Menkes disease by positional cloning.

Menkes disease is an X-linked recessive disorder of copper metabolism resulting in death in early infancy. The gene has been mapped to band Xq13 based, in part, on a translocation breakpoint in a female with the disease, which was found to lie within 300 kilobases (kb) of the PGK-1 locus, allowing the isolation of a YAC clone spanning the breakpoint. Phage subclones from the breakpoint region were isolated and used to screen cDNA libraries. cDNA clones were found which detect an 8 kb transcript from normal individuals but show diminished or absent hybridization in Menkes disease patients. Partial sequence of the cDNA shows a unique open reading frame containing putative metal binding motifs which have been found in heavy metal resistance genes in bacteria. This gene is a strong candidate for the Menkes disease gene.

Adenosine Triphosphatases↗
PubMed1992

Self-reactive repertoire of tight skin (TSK/+) mouse: immunochemical and molecular characterization of anti-cellular autoantibodies.

The tight skin (TSK/+) mouse has been proposed as an experimental model for progressive systemic sclerosis because of the biochemical alterations in collagen synthesis and pathological similarities to the human disease. Here, we report the analysis of tight skin mice sera for the presence of anti-cytoplasmic and anti-nuclear autoantibodies and determination of the frequency of hybridomas producing anti-cellular autoantibodies. The binding specificity of TSK mAbs to nuclear and cytoplasmic antigens such as keratin, actin, vimentin, and mitochondria was determined. Of 71 monoclonal antibodies that we have studied, only 3 appear to bind to foreign as well as self-antigens, indicating that the majority of these antibodies do not belong to the class of natural autoantibodies. Our results also showed that the frequency of hybridomas producing anti-nuclear and anti-cytoplasmic antibodies was higher in TSK mice than in C57BL/6 pa/pa, the control mouse strain, used in these studies. The results of the analysis of V gene usage showed that the majority of anti-cytoplasmic and anti-nuclear antibodies are encoded by genes from a restricted number of VH and VK genes families. In the sera of TSK mice we have detected the presence autoantibodies specific for cytoplasmic antigens in addition to anti-nuclear and anti-topoisomerase I antibodies which are characteristic of scleroderma. Since the presence of anti-cytoplasmic antibodies has not been described in scleroderma, the significance of their production in tight skin mice is not clear. However, the presence of such autoantibodies in the animal model provides a basis for investigation of this type of antibodies in human disease.

Actins↗
PubMed1992

Severe insulin resistance and diabetes mellitus in mandibuloacral dysplasia.

Mandibuloacral dysplasia (MAD) is a syndrome with onset in midchildhood. The predominant characteristics of MAD include flexion contractures; mandibular hypoplasia; loss of body fat; atrophic, speckled skin; and progressive osteolysis of the clavicles. We studied three males with MAD. Each had lipodystrophy of the extremities, with sparing of the face and neck. All had moderate hyperlipidemia. In response to oral glucose, each had a diabetic response, with peak insulin levels between 2870 and 22,960 pmol/L. Insulin-stimulated glucose disposal was determined in two patients with MAD. At an insulin infusion rate of 120 mU/m2 per minute, glucose disposal was less than 25% of that measured at similar levels of insulinemia in nondiabetic control subjects, indicating marked insulin resistance in patients with MAD. The insulin resistance occurred without obesity, excessive levels of counterregulatory hormones, or anti-insulin-receptor antibodies. We suggest that MAD is a previously undescribed form of lipodystrophic insulin-resistant diabetes mellitus.

Abnormalities, Multiple↗
PubMed1992

The effect of intermittent positive pressure breathing on lung volumes in acute quadriparesis.

Resting tidal volume and vital capacity were measured daily in 5 patients with acute quadriparesis during the first 7 to 10 days of their hospitalisation. On admission, vital capacity was significantly reduced to 26% of the predicted value (p less than 0.001). This increased significantly over the study period to 33% of the predicted value (p less than 0.02). Expiratory flow rates, measured on one occasion during the study period, showed similar decrements. Tidal volume and vital capacity were also measured immediately following administration of intermittent positive pressure breathing (IPPB). Although the lung volume achieved during IPPB was significantly higher than resting values of tidal volume and vital capacity (p less than 0.001), tidal volume returned to baseline values as soon as IPPB was ceased. Vital capacity remained significantly higher than baseline values at this stage (p less than 0.02), although the mean increase in vital capacity immediately following IPPB was only 43 mls. Acute quadriparesis is associated with a severe ventilatory impairment which includes a reduced vital capacity and expiratory flow rates. IPPB has a positive effect on lung volume whilst it is being administered. Immediately following treatment, this effect does not appear to be sustained at a level which would be considered clinically significant.

Acute Disease↗
PubMed1992

Association of Fyn with the activated platelet-derived growth factor receptor: requirements for binding and phosphorylation.

Three members of the Src family of tyrosine kinases [pp60c-src (Src), p59fyn (Fyn) and pp62c-yes (Yes)] are ubiquitously expressed, and are thus likely to have general roles in growth control. We have previously shown that, after addition of platelet-derived growth factor (PDGF) to quiescent cells, all three kinases become activated and associated with the PDGF receptor. We have now addressed the requirements for this association. First, we have used a baculovirus expression system to show that Fyn associates with the activated PDGF receptor in vitro in the absence of other proteins, demonstrating that the association between the two molecules is direct. Second, by generating cell lines expressing chimeric molecules consisting of Fyn sequences fused to a portion of beta-galactosidase, we found that the SH2 domain of Fyn is necessary for ligand-stimulated association with the PDGF receptor in vivo. Third, those fusion proteins that associated with the PDGF receptor also became phosphorylated in vivo following PDGF treatment, and in in vitro kinase assays, suggesting that the amino-terminal half of Fyn contains the sites of PDGF-stimulated phosphorylation. Partially purified, kinase-negative Fyn also became phosphorylated in the activated PDGF receptor complex in vitro, demonstrating that the PDGF receptor phosphorylates Fyn, rather than the novel phosphorylations occurring by autophosphorylation.

Base Sequence↗
PubMed1992

Nursing is...

Explore the source record for details and available documents.

Humans↗
PubMed1992

Designing a critical care unit: description of a multidisciplinary process.

Overall we are pleased to find that what sometimes seemed like hopeless space restrictions could be overcome by a combination of prudent compromise and innovative design. Even though the process consumed much time, the design of this new ICU turned out to be a satisfying process, marked by a true cooperative spirit among a group with diverse backgrounds and skills, all working toward a common goal.

Architecture↗
PubMed1991

Congenital anomalies in children of patients who received chemotherapy for cancer in childhood and adolescence.

BACKGROUND: Many patients who have been treated successfully for childhood cancer with regimens that contain one or more mutagenic chemotherapeutic agents are concerned that their own treatment during childhood or adolescence may adversely affect their children. METHODS: To determine the effect of chemotherapy for cancer during childhood and adolescence on the outcome of subsequent pregnancies, we reviewed the records of 306 men and women who had been treated for pediatric cancer and who responded to our questionnaire. One hundred of the 306 patients reported 202 pregnancies. Among the patients who had received chemotherapy as part of their treatment for cancer, 60 patients or wives of patients had had one or more pregnancies of 20 or more weeks' gestation. The 60 former patients had a total of 100 live-born and 2 stillborn children. RESULTS: The frequency of congenital anomalies was 8.1 percent (5 of 62) among the live-born children of the women and 7.9 percent (3 of 38) among the live-born children of the men. Structural congenital cardiac defects were identified in 10.0 percent (2 of 20) of the children of women who had been treated with dactinomycin, as compared with 0.6 percent (144 of 24,153) among the children in a multicenter survey of fetal anomalies (P = 0.0126). We found no relation between the number of mutagens received or the cumulative dose of any agent received and the frequency of congenital anomalies in the children. CONCLUSIONS: These data suggest that treatment of children and adolescents with mutagenic chemotherapeutic agents, in the dose ranges we examined, does not increase the frequency of congenital anomalies in the children subsequently born to the former patients. However, the possible adverse effect of dactinomycin on the children of such patients requires further study.

Abnormalities, Drug-Induced↗
PubMed1991

Achievement of life goals by adult survivors of modern treatment for childhood cancer.

To assess the impact of the diagnosis and modern treatment of childhood cancer on achievement of adult goals, the authors evaluated employment, health and life insurance coverage, marriage, divorce, and reproduction in 227 former pediatric cancer patients. Each area was evaluated in relation to a common set of disease and demographic factors that included age at follow-up, age at diagnosis, gender, marital status, history of disease recurrence, and diagnosis. Patients were younger than 20 years of age at diagnosis, and their diagnoses were made between January 1, 1960, and December 31, 1984. The median age at diagnosis was 11.4 years, and the median age at follow-up was 26.6 years. The percentage of unemployed male respondents did not differ from population norms. The percentage of unemployed female respondents, however, was slightly higher than that of the United States population. Approximately 11% of the survivors reported some form of employment-related discrimination, a level significantly lower than that of prior reports. Company-offered health insurance was provided to 92.4% of full-time and 90.0% of part-time employed respondents. Life insurance was purchased by 60% of full-time employed men and 55% of women. These percentages were lower than those reported for the United States population. Twenty-four percent of those with life insurance had difficulty obtaining it. Fifty-eight percent of the subjects were married or lived as married. The percentages of married men and women were significantly lower than United States norms. Twenty percent of those who were married or lived as married have divorced or separated or no longer live as married. Women aged 20 to 24 years were less likely to marry, and women aged 35 to 44 years had a significantly higher frequency of divorce than similarly aged United States women. In general, the history of childhood cancer did not influence the decision to marry or live as married but was occasionally (20%) important in the decision to dissolve a marital relationship. Many former patients indicated that their diagnosis and treatment for childhood cancer influenced their decision to have children. The current study suggests that most former pediatric cancer patients achieve adult life goals. Additional research is necessary to define those populations at greatest risk of failure to achieve these goals.

Adolescent↗