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Biomedical subjects

J H Barnett

Publications and source records attributed to J H Barnett.

14 recordsLinked to original sources
PubMed2006

Cognitive reserve in neuropsychiatry.

BACKGROUND: The idea that superior cognitive function acts as a protective factor against dementia and the consequences of head injury is well established. Here we suggest the hypothesis that cognitive reserve is also important in neuropsychiatric disorders including schizophrenia, bipolar disorder and depression. METHOD: We review the history of passive and active models of reserve, and apply the concept to neuropsychiatric disorders. Schizophrenia is used as an exemplar because the effects of premorbid IQ and cognitive function in this disorder have been extensively studied. RESULTS: Cognitive reserve may impact on neuropsychiatric disorders in three ways: by affecting the risk for developing the disorder, in the expression of symptoms within disorders, and in patients' functional outcome. Cognitive failure below a certain threshold may alone, or in combination with common psychiatric symptoms, produce neuropsychiatric syndromes. CONCLUSIONS: Consideration of cognitive reserve may considerably improve our understanding of individual differences in the causes and consequences of neuropsychiatric disorders. For these reasons, the concept of cognitive reserve should be incorporated in future studies of neuropsychiatric disorder. It may be possible to enhance cognitive reserve through pharmacological or non-pharmacological means, such as education, neurocognitive activation or other treatment programmes.

Brain↗
PubMed1994

Effect of metoprolol on myocardial function and energetics in patients with nonischemic dilated cardiomyopathy: a randomized, double-blind, placebo-controlled study.

OBJECTIVES: This study examined the effects of metoprolol on left ventricular performance, efficiency, neurohormonal activation and myocardial respiratory quotient in patients with dilated cardiomyopathy. BACKGROUND: The mechanism by which beta-adrenergic blockade improves ejection fraction in patients with dilated cardiomyopathy remains an enigma. Thus, we undertook an extensive hemodynamic evaluation of this mechanism. In addition, because animal models have shown that catecholamine exposure may increase relative fatty acid utilization, we hypothesized that antagonism of sympathetic stimulation may result in increased carbohydrate utilization. METHODS: This was a randomized, double-blind, prospective trial in which 24 men with nonischemic dilated cardiomyopathy underwent cardiac catheterization before and after 3 months of therapy with metoprolol (n = 15) or placebo (n = 9) in addition to standard therapy. Pressure-volume relations were examined using a micromanometer catheter and digital ventriculography. RESULTS: At baseline, the placebo-treated patients had somewhat more advanced left ventricular dysfunction. Ejection fraction and left ventricular performance improved only in the metoprolol-treated patients. Stroke and minute work increased without an increase in myocardial oxygen consumption, suggesting increased myocardial efficiency. Further increases in ejection fraction were seen between 3 and 6 months in the metoprolol group. The placebo group had a significant increase in ejection fraction only after crossover to metoprolol. A significant relation between the change in coronary sinus norepinephrine and myocardial respiratory quotient was seen, suggesting a possible effect of adrenergic deactivation on substrate utilization. CONCLUSIONS: These data demonstrate that in patients with cardiomyopathy, metoprolol treatment improves myocardial performance and energetics, and favorably alters substrate utilization. Beta-adrenergic blocking agents, such as metoprolol, are hemodynamically and energetically beneficial in the treatment of myocardial failure.

Cardiac Catheterization↗
PubMed1989

Disseminated ecthymatous herpes varicella-zoster virus infection in patients with acquired immunodeficiency syndrome.

Herpesvirus infections are among the most common and debilitating opportunistic infections in patients with acquired immunodeficiency syndrome (AIDS), and they may have atypical clinical features. We describe the cases of three patients with AIDS in whom atypical persistent ulcerative skin lesions developed as a result of varicella-zoster virus infection. Two patients had disseminated infection without a vesicular stage; one patient had underlying asteatotic eczema. All responded well to acyclovir. One patient was treated with azidothymidine, and typical dermatomal herpes zoster subsequently developed. The profound loss of helper T cell function in AIDS may lead to multiple abnormalities in local immune response to cutaneous herpesvirus infections and may be responsible for the atypical morphology and a prolonged course.

Acquired Immunodeficiency Syndrome↗
PubMed1986

Linear porokeratosis: treatment with the carbon dioxide laser.

A patient with a lifelong linear porokeratosis was treated with a carbon dioxide laser. The laser was successful in removing the patient's hyperkeratotic plantar lesion. No recurrence has been noted in a 6-month follow-up visit. This report demonstrates another dermatologic condition that can be treated successfully with the CO2 laser.

Adult↗
PubMed1984

Lichenoid drug reactions to chlorpropamide and tolazamide.

Many medications, including gold, antimalarials, quinidine, and thiazide diuretics have been implicated in lichenoid drug reactions. Chlorpropamide and tolazamide are sulfonylurea oral hypoglycemic agents, neither of which has previously been implicated in cutaneous lichenoid reactions. We report a case of lichenoid drug reaction related to both chlorpropamide and tolazamide.

Aged↗
PubMed1983

Erysipeloid.

Erysipelothrix infections have been a well-known clinical entity for over a century. Only a few cases have been studied histologically, and the agent has rarely been cultured from infected patients. We present here a case of erysipeloid of Rosenbach, in which histologic study and electron microscopy document the presence of microorganisms. We also present a complete review of the clinical and pathologic features of Erysipelothrix infections and their treatment. Our observations suggest that Erysipelothrix rhusiopathiae is capable of producing L forms that may revert to a bacterial form and produce sepsis at a later time.

Erysipeloid↗