PubMed Health⌕ Search

Biomedical subjects

D J Fox

Publications and source records attributed to D J Fox.

At least 19 recordsLinked to original sources
PubMed2005

Optimisation of cardiac resynchronisation therapy: addressing the problem of "non-responders".

Cardiac resynchronisation therapy has become firmly established as a treatment for patients with symptomatic heart failure. Several randomised controlled trials and numerous observational studies have demonstrated improvements in exercise capacity and quality of life. Despite these advances it is clear that approximately 25% of patients who meet current criteria for implantation of such a device do not show objective evidence of clinical benefit. Implantation of a CRT device is expensive, time consuming and involves some risk so it is important to accurately identify patients who are likely to respond and to optimise pacing lead placement and device programming to maximise the benefit in these selected patients.

Arrhythmias, Cardiac↗
PubMed2005

Pulmonary artery dissection: an emerging cardiovascular complication in surviving patients with chronic pulmonary hypertension.

Pulmonary arterial dissection is an extremely rare and usually lethal complication of chronic pulmonary hypertension. The condition usually manifests as cardiogenic shock or sudden death and is therefore typically diagnosed at postmortem examination rather than during life. However, recent isolated reports have described pulmonary artery dissection in surviving patients. The first case of pulmonary artery dissection in a surviving patient with cor pulmonale caused by chronic obstructive pulmonary disease is presented. The aetiology, pathophysiology, and clinical presentation of pulmonary artery dissection are reviewed and factors that may aid diagnosis during life are discussed.

Aortic Dissection↗
PubMed2005

Patients undergoing coronary revascularisation: a missed opportunity for secondary prevention?

BACKGROUND: This study tested the hypothesis that the opportunity to start secondary prevention therapy before discharge after coronary revascularisation is being missed. The study assessed current prescribing practice and identified discrepancies in prescribing for patients managed by surgeons (especially) and cardiologists. METHODS: 200 consecutive patients from the Manchester Heart Centre percutaneous coronary intervention (PCI) and coronary artery bypass (CABG) registries were identified (100 from each registry) and the notes analysed. All had undergone coronary revascularisation from February 2002 to March 2002. Data were analysed using SPSS for Windows, version 10.1. RESULTS: After exclusion of two patients with contraindications, 100% (98 of 98) of PCI patients and 92% (90 of 98) CABG patients were prescribed aspirin at discharge. Eight two per cent of eligible PCI patients and 70% of eligible CABG patients were prescribed beta blockers at discharge. Ninety six per cent (96 of 100) of PCI patients and 73% (73 of 100) of CABG patients were prescribed statins of any dose at discharge, (p<0.001). Sixty five per cent of PCI but only 26% of CABG patients were discharged prescribed ACE inhibitors (eligible patients based on HOPE, heart outcomes prevention evaluation trial), (p<0.001). CONCLUSIONS: Secondary prevention prescription after coronary revascularisation remains suboptimal in all but aspirin use. Patients in the PCI group were statistically more likely to be discharged prescribed a statin or an ACE inhibitor, or both, than patients after CABG. Both interventional cardiologists and (especially) cardiac surgeons must improve their use of secondary prevention therapy.

Adrenergic beta-Antagonists↗
PubMed2001

An examination of hyperconjugative and electrostatic effects in the hydride reductions of 2-substituted-4-tert-butylcyclohexanones.

To better understand electronic effects on the diastereoselectivity of nucleophilic additions to the carbonyl group, a series of 2-X-4-tert-butylcyclohexanones (X = H, CH(3), OCH(3), F, Cl, Br) were reacted with LiAlH(4). Reduction of ketones with equatorial substituents yields increasing amounts of axial alcohol in the series for X [H < CH(3) < Br < Cl < F << OCH(3)]. These data cannot be explained by steric or chelation effects or by the theories of Felkin-Anh or Cieplak. Instead, an electrostatic argument is introduced: due to repulsion between the nucleophile and the X group, axial approach becomes energetically less favorable with an increase in the component of the dipole moment anti to the hydride approach trajectory. The ab initio calculated diastereoselectivities were close to the experimental values but did not reproduce the relative selectivity ordering among substituents. For reduction of ketones with axial substituents, increasing amounts of axial alcohol are seen in the series for X [Cl < Br < CH(3) < OCH(3) < H < F]. After some minor adjustments are made, this ordering is consistent with both the electrostatic model and Felkin-Anh theory. Cieplak theory cannot account for these data regardless of adjustments. Ab initio calculated diastereoselectivities were reasonably accurate for the nonpolar substituents but were poor for the polar substituents.

Journal Article↗
PubMed1999

Evaluation of a targeted HIV testing program for at-risk youth.

With the advent of new therapies for HIV, case identification through HIV counseling and testing (CTS) has become critically important. Young women, youth of color, and disenfranchised youth are at significant risk of acquiring HIV. This study describes clients who access CTS at a program of comprehensive care for high-risk youth (aged 12 to 24 years), and assessed, using logistic regression analyses, whether youth at highest risk utilized CTS. Most of the 531 youth were female (72 percent) and nonwhite (60 percent). Sixty-eight percent received CTS. Logistic regression modeling revealed that white race and receiving care at the teaching hospital were the only independent predictors of testing. Data indicate that, despite targeted, youth-specific, developmentally appropriate and culturally sensitive outreach and intervention efforts, youth of color and high-risk youth are poorly accessing CTS. A greater understanding of the barriers to and cultural norms regarding CTS is needed.

AIDS Serodiagnosis↗
PubMed1998

Boston HAPPENS Program: a model of health care for HIV-positive, homeless, and at-risk youth. Human immunodeficiency virus (HIV) Adolescent Provider and Peer Education Network for Services.

The Boston HAPPENS [Human immunodeficiency virus (HIV) Adolescent Provider and Peer Education Network for Services] Program is a project supported by Special Projects of National Significance (SPNS) Program, HIV/AIDS Bureau, Health Resources and Services Administration, which provides a network of care for homeless, at-risk, and HIV-positive youth (ages 12-24 years), involving eight agencies. The program has provided services to 1301 youth, including 46 who are HIV-positive. Boston HAPPENS provides a citywide network of culturally and developmentally appropriate adolescent-specific care, including: (a) outreach and risk-reduction counseling through professional and adult-supervised peer staff, (b) access to appropriate HIV counseling and testing support services, (c) life management counseling (mental health intake and visits as part of health care and at times of crisis), (d) health status screening and services needs assessment, (e) client-focused, comprehensive, multidisciplinary care and support, (f) follow-up and outreach to ensure continuing care, and (g) integrated care and communication among providers in the metropolitan Boston area. This innovative network of youth-specific care offers a continuum from street outreach to referral and HIV specialty care that crosses institutional barriers.

Acquired Immunodeficiency Syndrome↗
PubMed1996

Tissue-specific regulation of sialyltransferase activities in the rat by corticosteroids in vivo.

In this study we have examined the effects of corticosteroids on both the total sialyltransferase (sialyl-T) activity and on two individual isozymes in neural, hepatic, and renal tissues using an in vivo model system. Rats were adrenalectomised to deplete their endogenous stores of steroid hormones, and some subsequently received steroid replacement with dexamethasone or aldosterone. Adrenalectomy resulted in a significant decrease in total neural sialyl-T activity when compared with sham-operated animals in the four brain regions examined, indicating that total sialyl-T activity is normally under positive corticosteroid control. The subsequent effects of exogenous corticosteroids exhibited regional specificity with the enzyme activities in the cortex, cerebellum, and brainstem being stimulated by both dexamethasone and aldosterone and enzyme activity in the hippocampus being stimulated by aldosterone alone. In general, the changes in total enzyme activity could be attributed to the alpha 2,6 sialyl-T isozyme, although the changes in the cerebellum appeared to coincide with alpha 2,3 sialyl-T activity. In the liver, adrenalectomy resulted in an increase in enzyme activity which was not altered by administration of corticosteroids. There were no changes in total renal sialyl-T activity in any of the four experimental groups although certain changes were observed at the level of individual sialyl-T isozymes. These results demonstrate that sialyl-T activity in certain tissues is under the control of corticosteroids and that this is both a tissue-specific and region-specific effect.

Adrenal Cortex Hormones↗
PubMed1995

The first solvation shell of magnesium ion in a model protein environment with formate, water, and X-NH3, H2S, imidazole, formaldehyde, and chloride as ligands: an Ab initio study.

The first coordination shell of an Mg(II) ion in a model protein environment is studied. Complexes containing a model carboxylate, an Mg(II) ion, various ligands (NH3, H2S, imidazole, and formaldehyde) and water of hydration about the divalent metal ion were geometry optimized. We find that for complexes with the same coordination number, the unidentate carboxylate-Mg(II) ion is greater than 10 kcal mol-1 more stable than the bidentate orientation. Imidazole was found to be the most stable ligand, followed in order by NH3, formaldehyde, H2O, and H2S.

Cations↗
PubMed1990

Efficacy of sedation of children with chloral hydrate.

Chloral hydrate has been used extensively to sedate children, but at Brooke Army Medical Center, other drug combinations were becoming increasingly popular due to a perception that chloral hydrate had a high rate of failure, especially with younger or neurologically impaired children. Therefore, 50 children were given the drug before a diagnostic study, and patient data and a sedation score were recorded on a worksheet. Of 50 children, 43 (86%) were "successfully sedated" on the first attempt with no side effects. Children with neurologic disorders had a much greater (27% vs 4%) failure rate than "normal" children. The sedation rate did not significantly differ by age, sex, or initial drug dosage. The study suggest that chloral hydrate is a safe and effective oral sedative but that children with neurologic disorders may need alternative drugs for sedation.

Administration, Oral↗