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Biomedical subjects

D Barber

Publications and source records attributed to D Barber.

At least 73 records · Page 4Linked to original sources

Research into the role of fertility nurses for the development of guidelines for clinical practice.

The Fertility Nurses Group (FNG) celebrates its 10th anniversary this year after a decade of many exciting developments. The pioneers of the FNG believed that professional advice and support were needed for nurses developing their roles within a dynamic and rapidly advancing field with new clinical and scientific techniques which also brought challenging moral dilemmas. A specialist membership group was therefore established with the Royal College of Nursing (RCN). One of the first tasks was to investigate the educational requirements of infertility nurses and assess the professional and ethical issues raised by nurses caring for infertile patients. The results of this were published in the first 'professional survey'. A decade later the FNG undertook further research into the scope of clinical practice and the working conditions of its membership. Members of the group directly involved with the provision of fertility treatment, from ovulation induction to in-vitro fertilization, were surveyed. A questionnaire was circulated which aimed to: (i) assess the roles, skill and working patterns of nurses working in infertility units; (ii) identify the training needs of nurses and the management and educational provision required to support this. Further research will also be undertaken to explore issues related to the extended role of fertility nurses and its relevance to the UK Central Council guidelines on clinical nurse specialists and advance nurse practitioners. The results of the forthcoming research studies will provide data to assist with: (i) the development of guidelines for clinical practice; and (ii) continued development of appropriate educational programmes for fertility nurses.

Infertility↗

Specific depletion of the house dust mite allergen Der p 1 cereal flour prolamins.

BACKGROUND: Quantitation of Der 1 and Der 2 in dust samples by specific monoclonal antibodies is a method used increasingly to evaluate mite allergen exposure. The level of Der 1 has been proposed as a risk factor for sensitization. AIM: We report a drastic decrease in the Der 1/Der 2 ratio when dust samples are collected in bakeries. METHODS: Wheat flour and purified mites were extracted simultaneously; levels of Der p 1 and Der p 2 and cysteine protease activity were determined by ELISA and inhibition experiments. RESULTS: High titers of Der 2, but only trace amounts of Der p 1, were detected in dust collected from bakeries. Both the level and proteolytic activity of Der p 1 appeared greatly decreased when mites and wheat flour were coextracted. CONCLUSION: Group 1 protein was found to be masked by flour components, resulting in an underestimation of the mite content in bakery dust. This problem was not found for group 2 allergen.

Allergens↗

Long-term glucose homeostasis in patients on home parenteral nutrition.

Glycated haemoglobin (Hb A1c) was used as a marker of long-term hyperglycaemia in patients receiving high glucose loads for home parenteral nutrition (HPN). Thirty-six patients received a median weekly glucose delivery of 2000 g (800-4200) at a median infusion rate of 11.8 mg/kg/min (5.0-19.2). There was no correlation between Hb A1c (median- 3.1%, range 2.0-6.3%) and glucose infusion rate or weekly glucose load. It is concluded that significant prolonged hyperglycaemia does not appear to be a problem in patients on HPN managed by this unit.

Journal Article↗

Nurses performing embryo transfer: successful outcome of in-vitro fertilization.

This prospective study demonstrates the feasibility and outcome of embryo transfer performed by nursing staff with medical cover available. Of 771 patients who had embryo transfer, 679 (88%) had their embryo transfer performed by a nurse. In 92 cases (12%) a doctor performed the embryo transfer, either as the first operator, or having been brought in to assist the nurse who experienced difficulty. The pregnancies per transfer for nurse transfer was 246/679 (36%) and where a doctor performed the transfer 20/68 (29%). These data show a high comparable success rate when a nurse performed the embryo transfer, and a low incidence of direct medical involvement.

Embryo Transfer↗

Interaction of allergens from house-dust mite and from cereal flours: Dermatophagoides pteronyssinus alpha-amylase (Der p 4) and wheat and rye alpha-amylase inhibitors.

Major wheat and rye allergens associated with baker's asthma have been identified as specific inhibitors of Dermatophagoides pteronyssinus alpha-amylase (Der p 4). the most active inhibitors were the wheat tetrameric one and the rye dimeric RDAI-1. these data suggest that interaction between mite and cereal allergens (alpha-amylase/inhibitor complexes) might occur in house-dust-mite-infected flours. In contrast to the strong inhibition of the d. pteronyssinus enzyme by the wheat and rye inhibitors, the amylases from D. farinae, Lepidoglyphus destructor, and Tyrophagus putrescentiae were much less affected. Moreover, the D. pteronyssinus amylase showed higher pH optimum (6.5 versus 5.0) and activity level (2-6 times/mg of protein in whole-mite extracts) than those from the three other mite species.

Allergens↗

Effect of arsenic exposure on alveolar macrophage function. II. Effect of slightly soluble forms of As(III) and As(V).

The pulmonary toxicity of a substance depends on a number of chemical and physical characteristics, including the solubility of the compounds. In the lung, insoluble forms of metals may be more tumorigenic than soluble forms despite the fact that this effect has not been quantitated and the mechanism of action has not been elucidated. The toxic effects of slightly soluble forms of As(III) and As(V) were evaluated by determining alteration in function of pulmonary alveolar macrophages (PAM) following in vivo and in vitro exposure. Male Sprague-Dawley rats were used throughout. Twenty-four hours following intratracheal instillation of 1 mg/kg (as arsenic) of either arsenic trisulfide (As(III)) or calcium arsenate (As(V)), PAM were lavaged and analyzed for alterations in superoxide (O2-), and tumor necrosis factor (TNF-alpha) production. There were no differences in bronchoalveolar lavage fluid TNF-alpha. PAM lavaged from As(V)-exposed animals showed significant increases in O2- production and in basal release of TNF-alpha. PAM lavaged from animals receiving As(III) did not show significant alterations. To test the direct effects of arsenic, PAM were lavaged from control animals and exposed to concentrations of 0.1 to 300 micrograms/ml arsenic in vitro for up to 24 hr. Doses used were not cytotoxic to PAM, since LDH release was not significantly increased. Significant dose-dependent inhibition of O2- production was only evident after 24 hr exposure to arsenicals. Both As(III) and As(V) produced inhibition at concentrations of 10 micrograms/ml. Suppression of LPS-induced release of TNF-alpha also occurred at similar concentrations for both arsenicals (4-5 micrograms/ml). Neither arsenical inhibited prostaglandin E2 production. Measurement of soluble arsenic concentrations indicated dissolution of the compounds could not account for all of the effects seen. Arsenic-induced alteration in PAM function may compromise host defense.

Animals↗

Total parenteral nutrition modifies the acute phase response to Crohn's disease.

Measurements of the acute phase proteins, C-reactive protein (CRP) and orosomucoid are widely used to monitor the activity of Crohn's disease. The effect of TPN upon the levels of acute phase proteins is unknown. Serum levels of CRP and orosomucoid were measured simultaneously over a four year period in 13 patients receiving TPN for Crohn's disease, nine patients with noninflammatory causes of intestinal failure, and 16 patients with Crohn's disease treated without TPN. An acute phase response was found with a similar frequency in both groups of patients with Crohn's disease (73.6% and 83.9% for Crohn's with and without TPN respectively), but was less prevalent in patients receiving TPN for non-inflammatory causes of intestinal failure (56.1%, P < 0.01). In this latter group, the acute phase response consisted primarily of an isolated elevation of orosomucoid (78.4%), compared with patients with Crohn's disease alone (21.1%, P < 0.001) and with Crohn's disease and TPN (46.6%, P < 0.05). Liver function abnormalities were seen on 68.8% of occasions in patients with noninflammatory causes of intestinal failure who had elevated levels of orosomucoid, compared with 34.9% of occasions on which orosomucoid levels were normal (P < 0.001). TPN may lead to isolated elevation of serum levels of orosomucoid, reducing the value of this acute phase protein in monitoring the activity of Crohn's disease in patients receiving TPN.

Acute-Phase Proteins↗

In vivo allergenic activities of eleven purified members of a major allergen family from wheat and barley flour.

Eleven purified members of the alpha-amylase/trypsin inhibitor family from wheat and barley that showed very different IgE-binding capacities when previously assayed in vitro, were used in double blind in vivo diagnostic tests to further evaluate their allergenic activity. These tests were carried out in 31 patients who showed allergic sensitization to wheat flour as verified by skin test, RAST and challenge test. The three members of the protein family with highest IgE binding in vitro (the glycosylated subunits of tetrameric alpha-amylase inhibitors CM16* from wheat and CMb* from barley, and the barley monomeric inhibitor BMAI-1) were found to be the strongest allergens as indicated by skin sensitivity in prick tests.

Adolescent↗

Endobronchial hamartoma. A case report.

A patient with a very rare benign bronchial tumour who presented in a most unusual manner is described. An endobrachial hamartoma was expectorated 24 hours after bronchoscopic manipulation for a suspected malignant tumour.

Bronchial Neoplasms↗

Chromosome size-dependent control of meiotic recombination.

Smaller chromosomes have higher rates of meiotic reciprocal recombination (centimorgans per kilobase pair) than larger chromosomes. This report demonstrates that decreasing the size of Saccharomyces cerevisiae chromosomal DNA molecules increases rates of meiotic recombination and increasing chromosome size decreases recombination rates. These results indicate that chromosome size directly affects meiotic reciprocal recombination.

Chromosome Mapping↗

Wheat and barley allergens associated with baker's asthma. Glycosylated subunits of the alpha-amylase-inhibitor family have enhanced IgE-binding capacity.

A 16 kDa protein, designated CM16*, which strongly binds IgE from baker's-asthma patients has been identified as a glycosylated form of the previously reported WTAI-CM16, which is a subunit of the wheat tetrameric alpha-amylase inhibitor. A glycosylated form (CMb*) of BTAI-CMb, the equivalent inhibitor subunit from barley, has been also found to have significantly enhanced IgE-binding capacity. In all, 14 purified members of the alpha-amylase/trypsin-inhibitor family showed very different IgE-binding capacities when tested by a dot-blot assay. The glycosylated components CM16*, CMb* and the previously described non-glycosylated 14.5 kDa allergen from barley (renamed BMAI-1) were found to be the strongest allergens.

Allergens↗

Monoclonal antibodies against Olea europaea major allergen: allergenic activity of affinity-purified allergen and depleted extract and development of a radioimmunoassay for the quantitation of the allergen.

Several monoclonal antibodies (MAbs) were raised against Olea europaea pollen-extract components. Two of these antibodies, named OL 2 and OL 7, recognize two nonoverlapping, nonrepeating epitopes on the olive-allergen Ole e I, as demonstrated by different techniques. The allergen was purified in a single step by MAb-based affinity chromatography, and the allergen revealed a band at molecular weight 20 kd as well as a minor band at 18 kd on sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The contribution of allergen Ole e I to the allergenic activity of O. europaea pollen extracts was determined from the effect of allergen depletion by affinity chromatography on skin reactivity and a histamine-release test. The removal of allergen caused a large reduction in the activity of the preparation in 25 monospecific olive-allergic patients. In agreement, the affinity-purified allergen demonstrated a similar response when it was compared with the whole extract in these assays. The results indicated that Ole e I is by far the most important olive-pollen allergen. A two-site solid-phase radioimmunoassay was developed for the quantitation of the allergen Ole e I in mass units. The assay was based on the MAbs, OL 2 and OL 7, and had a detection limit in the nanogram range. A good correlation was found between allergenic activity, as determined by RAST inhibition, and allergen content in 18 olive-pollen extracts. This result indicates that the assay can be a good alternative to RAST inhibition for the standardization of O. europaea extracts.

Allergens↗