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Biomedical subjects

M Hadley

Publications and source records attributed to M Hadley.

At least 19 recordsLinked to original sources

The historical development of human resources policies in the health sector of four Caribbean territories: imitated or created?

Health systems are labour intensive, dependent on a mix of professionals to provide health care in both public and private sectors. In this paper, we explore the historical development of human resources, focusing on doctors and nurses, in four Caribbean territories-the Bahamas, Martinique, Suriname and Trinidad and Tobago. All these territories have faced issues around the out-migration of doctors and nurses and tensions between public health, hospital services and private sector policies. Early policies to increase the number of nurses and doctors were costly, because they were implemented against a tide of increasing outward migration. Both push and pull factors were evident. Human resources policies focused on ways to counter pull factors-such as introducing regional medical training-but neglected push factors. These began to be addressed from the 1980s on, although tensions between public health, hospital services and private sector policies led to resistance and conflicts in attitudes to reform among health professionals. Policy responses were the product of many influences, and it is too simple to conclude they were either imported from abroad or internally generated. However, it is clear that in all four territories the medical profession played a dominant role in human resources policy development either directly or indirectly.

Bahamas↗

Chlorogenic acid modifies plasma and liver concentrations of: cholesterol, triacylglycerol, and minerals in (fa/fa) Zucker rats.

Chlorogenic acid, a phenolic compound found ubiquitously in plants, is an in vitro antioxidant and metal chelator. Some derivatives of chlorogenic acid are hypoglycemic agents and may affect lipid metabolism. Concentrations of cholesterol and triacylglycerols are of interest due to their association with diseases such as non-insulin-dependent-diabetes- mellitus and obese insulin resistance. As little is known about the effects of chlorogenic acid in vivo, studies using obese, hyperlipidemic, and insulin resistant (fa/fa) Zucker rats were conducted to test the effect of chlorogenic acid on fasting plasma glucose, plasma and liver triacylglycerols and cholesterol concentrations. Aditionally, the effects of chlorogenic acid on selected mineral concentrations in plasma, spleen, and liver were determined. Rats were implanted with jugular vein catheters. Chlorogenic acid was infused (5 mg/Kg body weight/day) for 3 weeks via intravenous infusion. Chlorogenic acid did not promote sustained hypoglycemia and significantly lowered the postprandial peak response to a glucose challenge when compared to the same group of rats before Chlorogenic acid treatment. In Chlorogenic acid-treated rats, fasting plasma cholesterol and triacylglycerols concentrations significantly decreased by 44% and 58% respectively, as did in liver triacylglycerols concentrations (24%). We did not find differences (p > 0.05) in adipose triacylglycerols concentration. Significant differences (p < 0.05) in the plasma, liver, and spleen concentration of selected minerals were found in chlorogenic acid-treated rats. In vivo, chlorogenic acid was found to improve glucose tolerance, decreased some plasma and liver lipids, and improve mineral pool distribution under the conditions of this study.

Journal Article↗

Capillary electrophoresis in the pharmaceutical industry: applications in discovery and chemical development.

Over the last 10 to 15 years capillary electrophoresis (CE) has become an extensively used separation technique in the pharmaceutical industry. The attraction of the various modes of operation of CE to analysts is their complementarity to other more established methodology, in particular high-performance liquid chromatography. CE methods have been developed not only for the resolution of drug substances that vary widely in their structure, size and stereochemistry, but also for the determination of the physico-chemical constants of analytes, such as pKa and isoelectric point (pI) values, binding and complexation constants, and octanol-water partition coefficients.

Amino Acid Sequence↗

Urinary aldehydes as indicators of lipid peroxidation in vivo.

The excretion of malondialdehyde (MDA), lipophilic aldehydes and related carbonyl compounds in rat and human urine was investigated. MDA was found to be excreted mainly in the form of two adducts with lysine, indicating that its predominant reaction in vivo is with the lysine residues of proteins. Adducts with the phospholipid bases serine and ethanolamine and the nucleic acid bases guanine and deoxyguanosine also were found. Except for the adduct with deoxyguanosine (dG-MDA), the excretion of these compounds increased with peroxidative stress imposed in the form of vitamin E deficiency or the administration of iron or carbon tetrachloride. Marked differences in the concentration of dG-MDA in different tissues were correlated with their content of fatty acids having three or more double bonds, the putative source of MDA. Fourteen nonpolar and eleven polar lipophilic aldehydes and other carbonyl compounds were identified as their 2,4-diphenylhydrazine derivatives in rat urine. The excretion of five nonpolar and nine polar compounds was increased under conditions of peroxidative stress. The profile of lipophilic aldehydes obtained for human urine resembled that for rat urine. Except for a reported 4-hydroxynon-2-enal conjugate with mercapturic acid, the conjugated forms of the lipophilic aldehydes excreted in urine remain unidentified. Aldehyde excretion is influenced by numerous factors that affect the formation of lipid peroxides in vivo such as energy status, physical activity and environmental temperature, as well as by wide variations in the intake of peroxides in the diet. Consequently, urinalysis for aldehydic products of lipid peroxidation is an unreliable indicator of the general state of peroxidative stress in vivo.

Aldehydes↗

Community involvement in tuberculosis control: lessons from other health care programmes.

Decentralising tuberculosis control measures beyond health facilities by harnessing the contribution of the community could increase access to effective tuberculosis care. This review of community-based health care initiatives in developing countries gives examples of the lessons for community contribution to tuberculosis control learned from health care programmes. Sources of information were Medline and Popline databases and discussions with community health experts. Barriers to success in tuberculosis control stem from biomedical, social and political factors. Lessons are relevant to the issues of limited awareness of tuberculosis and the benefits of treatment, stigma, restricted access to drugs, case-finding and motivation to continue treatment. The experience of other programmes suggests potential for an expansion of both formal and informal community involvement in tuberculosis control. Informal community involvement includes delivery of messages to encourage tuberculosis suspects to come forward for treatment and established tuberculosis patients to continue treatment. A wide range of community members provide psychological and logistic support to patients to complete their treatment. Lessons from formal community involvement indicate that programmes should focus on ensuring that treatment is accessible. This activity could be combined with a variety of complementary activities: disseminating messages to increase awareness and promote adherence, tracing patients who interrupt treatment, recognising adverse effects, and case detection. Programmes should generally take heed of existing political and cultural structures in planning community-based tuberculosis control programmes. Political support, the support of health professionals and the community are vital, and planning must involve or stem from the patients themselves.

Communicable Disease Control↗

PH-metric log P 11. pKa determination of water-insoluble drugs in organic solvent-water mixtures.

The apparent acid dissociation constants (p(s)Ka) of two water-insoluble drugs, ibuprofen and quinine, were determined pH-metrically in acetonitrile water, dimethylformamide water, dimethylsulfoxide water, 1,4-dioxane-water, ethanol water, ethylene glycol-water, methanol water and tetrahydrofuran water mixtures. A glass electrode calibration procedure based on a four-parameter equation (pH = alpha + SpcH + jH[H+]+jOH[OH-]) was used to obtain pH readings based on the concentration scale (pcH). We have called this four-parameter method the Four-Plus technique. The Yasuda Shedlovsky extrapolation (p(s)Ka + log [H2O] = A/epsilon + B) was used to derive acid dissociation constants in aqueous solution (pKa). It has been demonstrated that the pKa values extrapolated from such solvent water mixtures are consistent with each other and with previously reported measurements. The suggested method has also been applied with success to determine the pKa values of two pyridine derivatives of pharmaceutical interest.

Analgesics, Non-Narcotic↗

Quality of life of stroke survivors.

Adaptation to stroke requires complex, long-term change in stroke survivors' lives. This study aimed at identifying those factors that influence quality of life (QOL) of geriatric stroke survivors 1-3 years post-discharge. The objectives were: to describe the overall quality of life of stroke survivors; to examine the relationships between sociodemographic variables, neurological variables, functional status, social support, perceived health status, depression, and overall QOL; and to determine the best predictors of QOL. Data were collected on 50 stroke survivors using a cross-sectional design and standardized questionnaires, including the Quality of Life Index, the Functional Independence Measure, the Social Support Inventory for Stroke Survivors and the Centre for Epidemiologic Studies Depression Scale. The overall quality of life of the study participants was low. The most important predictors of QOL were depression, marital status, quality of social support, and functional status. Depression was the strongest predictor of QOL. By employing a multi-dimensional perspective, this study confirmed that adaptation to stroke involves much more than physical function. Thus, rehabilitation programs for this group would be more effective if they are based upon a holistic approach.

Activities of Daily Living↗

Resolution of the diastereomers of a large synthetic peptide by capillary electrophoresis using nonionic surfactants.

A capillary electrophoretic method was developed for the determination of the diastereomeric composition of the bradykinin B2 antagonist, SB-238592-DB. The nonionic surfactant Brij 35 was demonstrated to be suitable for the baseline resolution of the three diastereoisomers of SB-238592-DB in the presence of a low pH phosphate buffer and small volume percentages of acetonitrile.

Amino Acid Sequence↗

Concentrations of selected vitamins and selenium in bison cuts.

We analyzed individual cuts from clod (Triceps brachii), ribeye (Longissimus thoracis), top round (semimembranosus), and top sirloin (Gluteus medius) from 12 fed bison bulls for content of selected vitamins and selenium. The bulls came from producers in the United States and Canada and had consumed concentrate diets plus hay free choice for at least 180 d. The mean nutrient concentrations of all of the bison cuts combined were as follows (per 100 grams of wet weight): .045 mg thiamin, .253 mg vitamin B6, 2.131 microg vitamin B12, no detectable vitamin C, .848 microg vitamin A, .047 mg alpha-tocopherol, .013 mg tau-tocopherol, and 25.464 microg selenium. The nutrient content values did not differ (P > .05) among the cuts of meat. Cuts from individual bulls were different (P < .05) with regard to alpha- and tau-tocopherols, selenium, and vitamin A but not with regard to thiamin, vitamin B6, and vitamin B12. Nutrient concentrations, with the exception of one nutrient, of five bison from the same producer were similar. Great variation was observed between the alpha- and tau-tocopherols, selenium, and vitamin A contents among bison bulls but not among cuts of meat.

Analysis of Variance↗

Prospective study on the use of bolus intrathecal baclofen for spastic hypertonia due to acquired brain injury.

OBJECTIVE: To determine if the intrathecal delivery of baclofen will decrease spastic hypertonia caused by brain injury. PATIENTS: Eleven patients more than 1 year after their brain injury with disabling lower extremity spastic hypertonia. SETTING: University tertiary care outpatient rehabilitation clinic. DESIGN: Patients were a consecutive sample randomized in a double blind, placebo-controlled crossover study. INTERVENTIONS: Bolus intrathecal injection of either normal saline or 50 micrograms baclofen. MAIN OUTCOME MEASURES: Data for Ashworth rigidity scores, spasm scores, and deep tendon reflex scores were collected for both the upper extremities (UE) and lower extremities (LE). Changes over time were assessed via Friedman's test. Differences between the placebo and active drug at any given time were assessed via Wilcoxon signed-rank. RESULTS: Four hours after injection with the active drug (maximum effect) the average LE Ashworth score decreased from 4.2 +/- 0.8 (SD) to 2.2 +/- 0.6 (p = .0033), spasm score from 3.1 +/- 1.0 to 1.0 +/- 0.7 (p = .0032), and reflex score from 3.3 +/- 0.5 to 1.0 +/- 1.3 (p = .0033). The average UE Ashworth score decreased from 3.3 +/- 1.3 to 1.9 +/- 0.8 (p = .0033), spasm score from 1.8 +/- 1.3 to 0.6 +/- 1.0 (p = .007), and reflex score from 2.7 +/- 0.5 to 1.7 +/- 0.6 (p = .0111). No trend was observed over time with placebo administration. There were significant reductions in the average for LE Ashworth (p < .0001), spasm (p < .0001), and reflex (p < .0001) scores and for UE Ashworth (p < .0001) and spasm (p < .0004) scores observed over 4 hours (maximum effect) with active drug administration. No significant differences were noted between the active drug and placebo groups before administration in LE and UE Ashworth, spasm, or reflex scores. There were significant differences between the active drug and placebo groups at 4 hours after administration for LE and UE Ashworth, spasm, and reflex scores (p < or = .0272). CONCLUSION: Intrathecal injection of baclofen is capable of reducing the spastic hypertonia associated with brain injury.

Adult↗

Increased formation and degradation of malondialdehyde-modified proteins under conditions of peroxidative stress.

The effect of increased in vivo lipid peroxidation on excretion of the main urinary metabolites of malondialdehyde (MDA) was investigated. peroxidative stress in the form of vitamin E deficiency or the administration of iron nitrilotriacetate or carbon tetrachloride was imposed on rats fed an MDA-free diet. Significant increases were observed in excretion of the lysine-MDA adduct epsilon-propenal lysine, its N-acetyl ester, and free MDA. Under the conditions imposed, the increments in excretion of the lysine adducts reflect increased peroxidative modification of tissue proteins in vivo. These adducts also were found to be the main forms of MDA excreted in human urine. Reacting 14C-bovine serum albumin (BSA) with MDA resulted in its accelerated proteolysis in vitro by soluble enzyme preparations derived from human erythrocytes and rat liver mitochondria. The increments observed were similar to those reported for the hydrolysis of BSA following its exposure to hydroxyl radicals. The results show that lipid peroxidation in vivo results in peroxidative damage to tissue proteins and indicate that such proteins are subject to an accelerated rate of proteolysis.

Animals↗

Nursing practice in Canada: the influence of current and proposed legislation.

Nursing practice in Canada is regulated by separate acts in each of the 10 provinces and two territories. These acts grant self-governance to the nursing profession, define a scope of practice, and establish mechanisms for registration and quality assurance. The Canada Health Act 1984, the Agreement on Internal Trade (1994) between provinces, and the North American Free Trade Agreement have potentially great effects on Canadian nursing by altering the regulation of professionals within the various jurisdictions.

Canada↗

Identification of a deoxyguanosine-malondialdehyde adduct in rat and human urine.

In an ongoing study, rat and human urine have been examined for the presence of malondialdehyde (MDA) derivatives as indicators of the nature of lipid peroxidative damage caused by this compound in vivo. MDA in urine was found to be present mainly in the form of two lysine adducts, one acetylated and the other unacetylated, reflecting in vivo reactions with tissue proteins. Two minor metabolites were identified as adducts with the phospholipid bases serine and ethanolamine and a third one as an adduct with the nucleic acid base guanine. The identification of an MDA adduct with deoxyguanosine (dG-MDA) among the products of hydrolysis of rat liver DNA suggested the possible occurrence of this compound in urine. In the present study dG-MDA was identified in rat and in human urine, and a high-performance liquid chromatographic method utilizing fluorescence detection was developed for its estimation. The method is sensitive to 1 pmol of dG-MDA and requires a minimum of 1 mL of rat urine or 5 mL of human urine. Its rate of excretion by five-week-old rats (28.54 +/- 2.28 nmol/kg/24 h) (mean +/- SEM) was higher than that for nine-week-old rats (6.29 +/- 1.02) and much higher than that for adult humans (0.40 +/- 0.05). The results indicate that, as reported for 8-hydroxy-deoxyguanosine, dG-MDA excretion is related to metabolic rate. Excretion of dG-MDA by the rat, like the excretion of total MDA, declines during growth on a body weight basis at a rate similar to the decrease in resting energy metabolism.(ABSTRACT TRUNCATED AT 250 WORDS)

Acetylation↗

A comparative evaluation of thiobarbituric acid methods for the determination of malondialdehyde in biological materials.

A comparative evaluation was made of the conventional spectrophotometric procedure and three published high performance liquid chromatographic (HPLC) procedures for the determination of malondialdehyde (MDA) as the thiobarbituric acid (TBA) derivative when applied to liver, fish meal, serum, and urine. Except for urine, spectrophotometric analysis overestimated MDA content. Purification of the TBA-MDA complex obtained from liver and fish meal on reverse phase cartridges was found to entail a loss of complex bound to residual peptides in the trichloracetic acid (TCA) extract. Mincing as opposed to homogenizing liver samples led to a doubling of values for MDA content. Hexanal was a major TBA reactant, in addition to MDA, in all the samples. Acid hydrolysis and heat were necessary for the release of MDA bound to the amino groups of proteins and other amino compounds. Methods for free MDA have limited application to biological materials except short term in vitro preparations such as peroxidizing microsomes, in which free MDA accumulates. On the basis of these and other observations, a modified HPLC procedure for the determination of MDA as the TBA-MDA complex is proposed.

Animals↗

Isolation of a guanine-malondialdehyde adduct from rat and human urine.

A 1:1 adduct of guanine with malondialdehyde (MDA) was isolated from rat and human urine. This compound was shown to be identical to a synthetic adduct prepared according to the procedure of Seto et al. (Bull. Chem. Soc. Jpn. 58, 3431-3435, 1985). The UV, NMR and other characteristics of the compound were consistent with the tricyclic pyrimidinopurine structure proposed by these investigators. Its endogenous origin is indicated by its presence in the urine of rats fed an MDA-free diet, and by the observation that its excretion increased following iron or carbon tetrachloride administration. It may serve as a marker for nucleic acid modification caused by lipid peroxidation in vivo.

Animals↗