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Biomedical subjects

S O'Neill

Publications and source records attributed to S O'Neill.

At least 37 records · Page 2Linked to original sources

Alpha1-antitrypsin deficiency: biological answers to clinical questions.

Alpha1-antitrypsin (alpha1AT) deficiency is a common lethal hereditary disorder of white persons of European descent. The condition is characterized by reduced serum levels of alpha1AT, a 52-kDa glycoprotein synthesized chiefly in the liver and, to a lesser extent, by macrophages and neutrophils. Alpha1AT acts as an antiprotease and is the physiological inhibitor of neutrophil serine proteases such as neutrophil elastase cathepsin G and proteinase 3. The clinical manifestations of alpha1AT deficiency occur chiefly in the lung, with a high risk of emphysema occurring by the third or fourth decade of life. Cigarette smoking accelerates the development of emphysema in persons with alpha1AT deficiency. There is also an increased risk of liver disease in alpha1AT deficiency, which occurs mostly in childhood. In this review, we will define further the diagnosis of alpha1AT deficiency and its clinical manifestations and describe the therapeutic strategies that are currently being developed to treat the hepatic and pulmonary disease associated with this condition.

Adult↗

Genetic counselling for schizophrenia in the era of molecular genetics.

OBJECTIVE: To review the role of genetic counselling for individuals with psychiatric illnesses. METHOD: Using schizophrenia as an example and including updated information about a genetic subtype (22q deletion syndrome), we discuss the value of the genetic counselling process in psychiatry, with support from the literature and our clinical experience. RESULTS: Genetic counselling, the process through which knowledge about the genetics of illnesses is shared, provides information on the inheritance of illnesses and their recurrence risks; addresses the concerns of patients, their families, and their health care providers; and supports patients and their families dealing with these illnesses. For comprehensive medical management, this service should be available to all individuals with schizophrenia and their families. CONCLUSIONS: New findings in the genetics of psychiatric illness may have important clinical implications for patients and their families.

Chromosome Deletion↗

Improved asthma control with budesonide/formoterol in a single inhaler, compared with budesonide alone.

Budesonide/formoterol in a single inhaler was compared with budesonide alone, and with concurrent administration of budesonide and formoterol from separate inhalers, in patients with asthma, not controlled with inhaled glucocorticosteroids alone. In this 12-week, double-blind, randomized, double-dummy study, 362 adult asthmatics (forced expiratory volume in one second 73.8% of predicted, inhaled glucocorticosteroid dose 960 microg x day(-1)) received single inhaler budesonide/formoterol (Symbicort Turbuhaler) 160/4.5 microg, two inhalations b.i.d., or corresponding treatment with budesonide, or budesonide plus formoterol via separate inhalers. There was a greater increase in morning peak expiratory flow (PEF) with single-inhaler (35.7 L x min(-1)) and separate-inhaler (32.0 L x min(-1)) budesonide and formoterol, compared with budesonide alone (0.2 L x min(-1); p<0.001, both comparisons); the effect was apparent after 1 day (p<0.001 versus budesonide, both comparisons). Similarly, evening PEF, use of rescue medication, total asthma symptom scores and percentage of symptom-free days improved more with both single inhaler and separate inhaler therapy than with budesonide alone, as did asthma control days (approximately 15% more, p<0.001 versus budesonide, both comparisons, with a marked increase in the first week). All treatments were well tolerated and the adverse event profile was similar in all three treatment groups. It is concluded that single inhaler therapy with budesonide and formoterol is a clinically effective and well-tolerated treatment for patients with asthma that is not fully controlled by inhaled glucocorticosteroids alone.

Administration, Inhalation↗

Nitinol stent insertion for post-pneumonectomy syndrome.

Post-pneumonectomy syndrome is an unusual condition, that can occur a variable period of time after a patient has had a pneumonectomy. Management of this syndrome has been described using a number of different techniques, often with considerable mortality. We present a case report where this condition was treated successfully by insertion of an expandable Nitinol stent. This is the first time this technique has been described to treat this condition, and we feel it may be the procedure of choice in managing these patients.

Alloys↗

The psychotherapy of a male anorectic.

The author describes the way in which a male anorexic patient came to be understood in once-weekly psychotherapy. The findings are similar to recent psychoanalytic ones about female anorectics, but add that he was preoccupied with display and that there was an erotised transference in the oral mode. Of two major themes, the first was a food obsession; the food was felt concretely to be the mother as in a symbolic equation, and the conflict about eating represented a wish for and fear of fusion with her. The second major theme concerned exhibition; the self, as seen in two screen memories, was felt to be uncomfortably on show. Meanwhile the patient was preoccupied with a self-displaying maternal object, which was prominent in the transference. This perception of the object served as a defence against envy, although the defensive aspect may have been added to by an actual experience of a mother who functioned operatively, giving food rather than loving attention. The patient employed primary-process thinking defensively against self-object differentiation, which would have excited further awareness both of envy and of the real deficiencies of his primary objects. The author raises the possibility that the anorexia functioned as a perversion, binding and organising the core complex about fusion.

Adult↗

Antioxidant prevention of Heinz body formation and oxidative injury in cats.

OBJECTIVE: To determine the effectiveness of 3 antioxidants in preventing Heinz body anemia in cats. DESIGN: Prospective study. ANIMALS: 44 specific-pathogen-free healthy cats. PROCEDURE: Cats were housed individually, divided randomly into 4 groups, and given the following orally every 12 hours: empty gelcaps (control cats), N-acetylcysteine (NAC, 100 mg/kg of body weight), vitamin E (d,l-alpha-tocopherol; 400 IU), or ascorbate (250 mg). After 2 weeks, Heinz bodies were induced by dietary onion powder (OP; 1% or 3% of dry matter) or propylene glycol (PG, 8% wt/vol in drinking water) for an additional 3 weeks. Intake of treated water or food was recorded daily. Body weight, PCV, Heinz body and reticulocyte percentages, reduced glutathione concentration, and total antioxidant status were measured twice weekly in all cats. RESULTS: Heinz body percentage and degree of anemia did not differ significantly among cats receiving antioxidants and control cats except in cats that ingested water containing PG, in which antioxidant supplementation was associated with a decrease in water intake. Of cats that were fed a diet that contained OP, cats that received NAC had significantly higher reduced glutathione concentrations, compared with other cats in the experiment. Total antioxidant status did not consistently correlate with antioxidant supplementation or type of oxidant administered (ie, OP or PG). CONCLUSIONS AND CLINICAL RELEVANCE: Although the effect of antioxidant supplementation on Heinz body anemia in cats was minimal, antioxidants may have subclinical biochemical effects such as GSH sparing that may be important against milder forms of oxidative stress.

Acetylcysteine↗

MYCN amplification and 17q in neuroblastoma: evidence for structural association.

MYCN oncogene amplification in neuroblastoma is statistically associated with gain of chromosome segment 17q21-qter. In neuroblastoma cell lines and primary tumors with MYCN amplification in the form of homogeneously staining regions (hsrs), juxtaposition of chromosome 17 material with MYCN sequences has occasionally been reported, raising the possibility of a physical affinity between MYCN and chromosome arm 17q. We used FISH to test for association between chromosome 17 segments and MYCN in eight neuroblastoma cell lines and two neuroblastoma primary tumors known to include hsrs. Evidence of an association was found in the chromosomes of both primary tumors; in one, a MYCN hsr was inserted into a structurally abnormal chromosome 17, in the other, an hsr in 16p was shown to be flanked by 17 material. In cell line NCG, hsrs in 4q and 16p were flanked by 17q material. These observations confirm the juxtaposition of 17q material with MYCN sequences in some neuroblastomas, and imply that there may be a physical or functional relationship between these two features in MYCN amplified neuroblastoma.

Child, Preschool↗

Daughters and mothers exercising together (DAMET): a 12-week pilot project designed to improve physical self-perception and increase recreational physical activity.

This paper presents the results of a 12-week single-sex, family-based physical activity intervention grounded in Social Cognitive Theory. Mother/daughter pairs and triads (n = 20) attended physical activity and classroom sessions twice weekly. Physiological data (VO2peak, height, and weight), psychological data (physical self-perception profile subscale scores), information about physical activity participation (PAP, d x wk(-1)) and qualitative impressions (QI) of the program were collected pre- and post-intervention. PAP and QI were also collected 6-months after completing the intervention. Although no significant increases in physical activity were reported, significant improvements in perceived sport competence, physical condition, and strength and muscularity were reported over time. The social cognitive theory, as used to plan this physical activity intervention, offered a promising theoretical perspective for facilitating improved physical self-perception in adolescent girls and their mothers.

Adolescent↗

Corticosteroid induced osteoporosis. Guidelines for treatment.

BACKGROUND: Last year, Australian Family Physician published 'Guidelines for Management of Postmenopausal Osteoporosis', which were developed by Osteoporosis Australia. Recently, significant advances in our understanding of the treatment of corticosteroid osteoporosis have occurred. OBJECTIVE: The following guidelines, also developed by Osteoporosis Australia, and supported by the National Asthma Campaign, are to help general practitioners identify those patients at risk of this problem and to provide information about current treatment strategies. DISCUSSION: Corticosteroids are widely used and effective agents for the control of many inflammatory diseases. Corticosteroid osteoporosis is a common problem associated with the long term high dose use of these medications.

Adrenal Cortex Hormones↗

Towards a safe future.

Creating a 'safety culture' requires an open approach to encourage analysis of deeper, systemic factors which may be causing serious failures. The NHS is setting systems in place which will work to end the most common and preventable errors.

Health Policy↗

The platelet integrin alpha IIbbeta 3 has an endogenous thiol isomerase activity.

Integrins are cysteine-rich heterodimeric cell-surface adhesion molecules that alter their affinity for ligands in response to cellular activation. The molecular mechanisms involved in this activation of integrins are not understood. Treatment with the thiol-reducing agent, dithiothreitol, can induce an activation-like state in many integrins suggesting that cysteine-cysteine dithiol bonds are important for the receptor's tertiary structure and may be involved in activation-induced conformational changes. Here we demonstrate that the platelet-specific integrin, alpha(IIb)beta(3), contains an endogenous thiol isomerase activity, predicted from the presence of the tetrapeptide motif, CXXC, in each of the cysteine-rich repeats of the beta(3) polypeptide. This motif comprises the active site in enzymes involved in disulfide exchange reactions, including protein-disulfide isomerase (EC ) and thioredoxin. Intrinsic thiol isomerase activity is also observed in the related integrin, alpha(v)beta(3), which shares a common beta-subunit. Thiol isomerase activity within alpha(IIb)beta(3) is time-dependent and saturable, and is inhibited by the protein-disulfide isomerase inhibitor, bacitracin. Furthermore, this activity is calcium-sensitive and is regulated in the EDTA-stabilized conformation of the integrin. This novel demonstration of an enzymatic activity associated with an integrin subunit suggests that altered thiol bonding within the integrin or its substrates may be locally modified during alpha(IIb)beta(3) activation.

Amino Acid Sequence↗

Development and application of surface plasmon resonance-based biosensors for the detection of cell-ligand interactions.

Surface plasmon resonance (SPR)-based biosensors were investigated with a view to providing a portable, inexpensive alternative to existing technologies for "real-time" biomolecular interaction analysis of whole cell-ligand interactions. A fiber optic SPR-based (FOSPR) biosensor, employing wavelength-dependent SPR, was constructed to enable continuous real-time data acquisition. In addition, a commercially available integrated angle-dependent SPR-based refractometer (ISPR) was modified to facilitate biosensing applications. Solid-phase detection of whole red blood cells (RBCs) using affinity-captured blood group specific antibodies was demonstrated using the BIACORE 1000, BIACORE Probe, FOSPR, and ISPR sensors. Nonspecific binding of RBCs to the hydrogel-based biointerface was negligible. However, the background noise level of the FOSPR-based biosensor was approximately 25-fold higher than that of the widely used BIACORE 1000 system while that of the ISPR-based biosensor was over 100-fold higher. Nevertheless, the FOSPR biosensor was suitable for the analysis of macromolecular analytes contained in crude matrices.

Biosensing Techniques↗