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Biomedical subjects

D Baldwin

Publications and source records attributed to D Baldwin.

At least 91 records · Page 5Linked to original sources

Cochlear blood flow in response to dilating agents.

Reduced cochlear blood flow (CBF) has been implicated in various pathologies of the inner ear, including sudden deafness, noise-induced hearing loss and Meniere's disease. Thus the aim of some current therapeutic regimens to treat these conditions is to increase CBF and thereby improve oxygenation of the inner ear tissues. Most of the vasodilating agents in clinical use, however, do not have specific experimental evidence to support their effects on CBF. The hypotension which can follow systemic administration may limit their local effectiveness and general utility, just as it complicates the interpretation of the data in animal experiments. In the current study we investigated the effect of six agents, known for their systemic cardiovascular actions, on CBF: hydralazine, sodium nitroprusside, papaverine, nicotinic acid, verapamil and histamine. The effect of these drugs was studied after topical applications on the round window membrane (RWM) and systemic intravenous administrations. CBF was monitored with a laser Doppler flowmeter (LDF). Topical administration of sodium nitroprusside was the most effective in increasing CBF, followed, in order, by hydralazine and histamine. No change in CBF was observed for papaverine, verapamil or nicotinic acid. Systemic administrations of all the agents caused a marked decrease in blood pressure and variable effects on CBF. We discuss the CBF changes in relation to the different pharmacological mechanisms of action of each drug. The study demonstrates the effectiveness of topical application of vasodilating agents in increasing CBF.

Administration, Topical↗

The family's role in stroke rehabilitation. A review of the literature.

Clinical and research attention in stroke care has been on managing the acute stage of stroke recovery and on evaluating the effectiveness of relatively short-term rehabilitation programs. However, studies suggest that stroke can diminish quality of life and the well-being of patients' families. This article reviews the literature pertaining to the effects of stroke on family functioning and discusses stroke in terms of clinical problems that make rehabilitation a family dilemma. Issues identified in the literature include the need for family assessment, education, advocacy and counseling to foster treatment compliance and social support after stroke.

Adaptation, Psychological↗

Pharmacotherapy in the prevention of suicidal behavior.

Prevention or reduction of suicide remains a serious challenge for the medical community. Psychotherapeutic and psychosocial interventions have not been shown to reduce the incidence of suicide attempts and analytic psychotherapy has been shown to increase suicidal behavior. The efficacy of pharmacotherapy in reducing suicide attempts in patients with a history of repeated suicidal behavior has been shown with low doses of the neuroleptic agent flupenthixol compared with placebo. Supporting findings have been reported with trifluoperazine. There is evidence to suggest that some antidepressants may not be neutral in their effect on suicidal behavior. Maprotiline, for example, was associated with an increase in suicide attempts compared with placebo in a large long-term treatment study despite its significant efficacy in preventing relapse of depression. Differential lethality indices taken from large community studies support the notion that noradrenergic drugs such as maprotiline, desipramine, and nortriptyline are associated with a higher than expected incidence of death from overdose, and the suicide-provoking potential may relate to some noradrenergic property. The studies of serotonergic antidepressants do not suggest that they are suicide-provoking agents; rather they appear to be neutral or protective. Prospective prophylactic studies are needed to test the ability of potential treatments for the reduction of suicidal behavior.

Antidepressive Agents↗

Failure of simple biochemical indexes to reliably differentiate fulminant Wilson's disease from other causes of fulminant liver failure.

Serum, urine and tissue biochemical findings were studied in 21 cases of fulminant Wilson's disease with respect to the value of a recently described biochemical index based on serum alkaline phosphatase and total serum bilirubin levels, and these cases were compared with 193 other cases of fulminant liver failure. Serum bilirubin, alkaline phosphatase and AST levels found in fulminant Wilson's disease were significantly different from those found in other cases of fulminant liver failure, but differentiation from other causes of fulminant liver failure on the basis of these biochemical parameters was not possible. The alkaline phosphatase/bilirubin and aspartate AST/bilirubin ratios derived from the above parameters were also significantly lower in fulminant Wilson's disease than in other categories of fulminant liver failure, but distinction between diagnostic categories on this basis was not possible. When ratios that correctly identified all cases of fulminant Wilson's disease were selected, 59/190 (31%) and 84/190 (44%) cases of non-Wilsonian fulminant liver failure would erroneously be assigned a diagnosis of fulminant Wilson's disease, by alkaline phosphatase/bilirubin and AST/bilirubin ratios, respectively. A low alkaline phosphatase-to-bilirubin ratio (< 0.57) in any category of fulminant liver failure suggested a significantly worse prognosis than in cases with higher ratios (chi 2, Yates' corrected = 5.37, p = 0.02). In the Wilson's disease group, serum and hepatic copper and ceruloplasmin concentrations were normal in 4/21, 2/15 and 2/19, respectively, whereas urinary copper level was elevated in 18/18 and was the most valuable test in diagnosis.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗

Nursing's agenda for health care reform: a critique.

This paper discusses the nature of the health care crisis with a focus on the issues of economics, the private insurance industry, race and ethics as they relate to Nursing's Agenda for Health Care Reform. Recommendations are made for assuring the entire population quality, equitable health care.

Delivery of Health Care↗

Biochemical and biophysical investigations of the ferrocene-iron-loaded rat. An animal model of primary haemochromatosis.

Male Wistar rats fed with ferrocene had high hepatic iron loading (7.24 +/- 1.97 mg Fe/g tissue) after 6 weeks, principally located in lysosomes, which was comparable to the levels and distribution determined in human haemochromatosis. The two iron-storage proteins, ferritin and haemosiderin were isolated from the livers of the ferrocene-loaded rats and their iron cores were investigated by Mössbauer spectroscopy and inductively coupled plasma-emission spectrometry. Ferrihydrite was the predominant form of iron present in both ferritin and haemosiderin, while haemosiderin contained higher amounts of phosphorus, magnesium, calcium and barium, then either normal or ferrocene-loaded ferritin. Free-radical-mediated damage in the iron-loaded livers was inferred by the significant depletion of alpha-tocopherol in both the livers and subcellular hepatic lysosomal fraction, which inversely correlated with the increasing iron content (r = -0.61; P less than 0.05) and was associated with increased fragility of the lysosomal membranes.

Animals↗

Fluoxetine dose.

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Depression↗

Multiple recurrent giant cell lesions associated with high circulating levels of parathyroid hormone-related peptide in a young adult.

Parathyroid hormone-related peptide (PTHrP, PLP) has previously been identified and assays are now available which can be used in clinical situations. A case is reported of a normocalcaemic young adult female in whom multifocal recurrent giant cell osteolytic lesions in the maxilla and elsewhere were associated with a raised plasma level of parathyroid hormone-related peptide. The lesions were histologically identical to reparative giant cell granuloma of the jaws and to osteitis fibrosa cystica associated with hyperparathyroidism.

Adult↗

Accuracy of CT in detecting squamous carcinoma metastases in cervical lymph nodes.

The accuracy of computed tomography (CT) in the assessment of nodal metastases was correlated retrospectively with the pathological examination in 28 patients with known head and neck squamous cell carcinoma, who underwent neck dissections. Three patients had bilateral neck dissections resulting in a total of 31 dissections. CT scanning correctly staged 28 of 31 neck dissections providing an accuracy of 90%, a sensitivity of 87.5% and a specificity of 100% in the detection of nodal metastases. Of the 21 true positives, underestimation of the extent of nodal disease occurred in seven cases. Regarding extracapsular nodal spread, CT resulted in an accuracy of 62%, a sensitivity of 62.5% and a specificity of 60%. All three false negatives for nodal metastases occurred in metastatic spread to the submandibular nodes. The existing criteria for assessment of nodal metastases with CT are sensitive and specific, but in the assessment of extranodal spread CT may not detect 37.5% of cases.

Carcinoma, Squamous Cell↗

In-vitro susceptibility of Chlamydia pneumoniae (TWAR) to seven antibiotics.

A modification of an immunofluorescence method previously used to study the in-vitro antimicrobial susceptibilities of Chlamydia trachomatis was used to investigate the activity of seven antimicrobials against a strain of C. pneumoniae. Our results differed from those obtained by other workers, so we modified our original method and repeated the study. Adding antimicrobial to pre-infected cells gave higher MICs and MLCs than when cells were infected in the presence of the antimicrobials, and this difference in methodology could account for the discrepancy between our results and those of others. Of the antimicrobials studied, clarithromycin and its 14-hydroxy metabolite were the most active agents; sparfloxacin was more active than ciprofloxacin, but no more active than more conventional antichlamydial agents.

Anti-Bacterial Agents↗

5-HT reuptake inhibitors, tricyclic antidepressants and suicidal behaviour.

Antidepressant drugs undoubtedly reduce much of the morbidity and mortality associated with a variety of depressive disorders. Certain types of antidepressant drugs have been shown to exert a relative advantage in the reduction of suicidal thoughts, and it is interesting that recent reports have noted an association between the prescription of some antidepressants and the development of suicidal and aggressive thoughts and behaviour. An analysis of the data from double-blind controlled trials of fluvoxamine, fluoxetine and paroxetine indicates that 5-HT uptake inhibitors exercise some protective effects on the emergence of suicidal thoughts, whereas the data from the studies with maprotiline show an increase in suicidal thoughts compared with placebo.

Antidepressive Agents↗

Hypoglycemia due to surreptitious injection of insulin. Identification of insulin species by high-performance liquid chromatography.

OBJECTIVE: To identify the circulating species of insulin after separation by high-performance liquid chromatography (HPLC) in patients with factitious hypoglycemia. RESEARCH DESIGN AND METHODS: In three of four patients presented, the diagnosis of surreptitious insulin injection was made by documenting the presence of animal insulin in the circulation after separation of the circulating insulin forms by HPLC. RESULTS: Animal insulin was identified. CONCLUSIONS: Thus, the identification of the circulating form of insulin in the circulation by HPLC may be a useful adjunct in the diagnosis of factitious hypoglycemia if animal insulin has been injected and if the simultaneously measured concentrations of insulin and C-peptide are inconclusive.

Adult↗