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Biomedical subjects

N Ford

Publications and source records attributed to N Ford.

At least 37 records · Page 2Linked to original sources

Motor control by vision and the evolution of cerebral lateralization.

Chicks (4 or 5 days old), which are able to use either eye freely, use the right eye (RE) preferentially in approach to a food dish when a lid, which has to be removed, is visible during approach. They use the left eye (LE) instead when no manipulation is required, but the same dish is similarly visible. The RE is also used preferentially in selecting food grains scattered over the floor; RE use in these two contexts is thus associated with visual control which brings the bill in planned contact with a visible target rather than with approach to a site where it is anticipated that feeding will occur. Zebrafish also use the RE preferentially when preparing to bite a target; during purely visual examination of the same target, this preference disappears. This evidence is used together with evolutionary evidence to support a new hypothesis for the origin of cerebral lateralization: paired anterior eyes evolved in filter-feeding ancestors of the vertebrates as part of the acquisition of prey catching. A key use for early vision was to predict likely contact with prey so as to inhibit reflexes of rejection and avoidance normally elicitated by tactile input to the mouth and so to allow ingestion. Innervation of mouth structures by the left side of the CNS caused control of mouth reflexes to become predominantly a left CNS affair. As visual abilities developed this starting condition meant that control of manipulation (which is by the mouth for most vertebrates) remained predominantly with the left side of the CNS.

Animals↗

A pragmatic intervention to promote condom use by female sex workers in Thailand.

An overview is presented of a multifaceted intervention to promote consistent condom use by female commercial sex workers in Thailand, in the context of the government's 100% condom use policy for preventing spread of human immunodeficiency virus (HIV) infection. The project is described with reference to a succession of stages including pre-programme needs assessment, intervention design, implementation and evaluation. The key elements of the intervention were video scenarios and discussions coordinated by health personnel, and video-depicted open-ended narratives aimed at helping sex workers to explore their personal and work-related dilemmas and concerns. A core objective was to enhance sex workers' self-esteem and perceived future with a view to strengthening their motivation to take preventive action against HIV infection. The intervention was evaluated using a combination of qualitative (process evaluation) and quantitative (outcome) methods. The outcome evaluation was undertaken using a pretest, post-test intervention and control group quasi-experimental design. There were significant increases in consistent condom use among the intervention groups but not among the controls. Pragmatic stability is advocated for the Thai sex industry and recommendations are offered for good quality HIV prevention activities.

Adolescent↗

Pharmacokinetics and pharmacodynamics of avitriptan in patients with migraine after oral dosing.

Avitriptan (BMS-180048) is a 5-HT1-like receptor agonist for the treatment of migraine. This double-blind, placebo-controlled, randomized, parallel-group study evaluated the pharmacokinetics, safety, and preliminary efficacy of avitriptan in patients with migraine during migrainous and pain-free states. Patients met the IHS criteria for migraine with or without aura and suffered one to six migraines per month for at least 1 year. Patients in a clinic experiencing a migraine headache received avitriptan 75 mg, 150 mg, or 200 mg or matching placebo capsules. Blood samples were obtained before and 0.25, 0.75, 1, 1.5, 2, 2.5, 3, 4, 5, and 6 hours after dosing. Headache intensity was rated before and up to 6 hours after dosing. Seven to 30 days after the inclinic treatment, patients returned in a pain-free state for the same study medication. All pharmacokinetic and safety measures were repeated. Forty-eight patients (9 men and 39 women) participated. Peak plasma concentrations of avitriptan were achieved 1 to 2 hours following dosing in migraine and pain-free states for all doses. The pharmacokinetics of avitriptan were proportional to dose during a migraine attack over the 75- to 200-mg dose range. The 150- and 200-mg doses of avitriptan demonstrated a greater decrease in headache intensity scores at 2 hours postdose. The most common adverse event was paresthesia. Thus, avitriptan was rapidly absorbed, well tolerated, and demonstrated preliminary efficacy in this population.

Administration, Oral↗

Effect of left ventricular hypertrophy and its regression on ventricular electrophysiology and vulnerability to inducible arrhythmia in the feline heart.

BACKGROUND: Left ventricular hypertrophy (LVH) is associated with an increased risk of death, susceptibility to ventricular arrhythmia, and multiple electrophysiological abnormalities. The purpose of the present study was to determine whether the susceptibility to arrhythmia and electrical abnormalities persists after regression of hypertrophy in an animal model of LVH. METHODS AND RESULTS: We placed constricting bands on the ascending aorta of cats (n = 9) or performed sham operations (n = 9). Serial cardiac echocardiography was performed to measure left ventricular wall thickness. After LVH had developed in the banded animals, the constricting bands were removed and serial echocardiograms were used to monitor for regression of hypertrophy. Electrophysiological studies were performed in cats that showed regression of LVH (Regress, n = 5), those that showed no change in LV wall thickness (No Regress, n = 4), and in the sham-operated animals (Sham). Cats with persistent LVH had a higher incidence of inducible polymorphic ventricular tachycardia (4 of 4) compared with Regress (1 of 5) or Sham (1 of 9) cats (P < .05) and had lower ventricular fibrillation thresholds (9 +/- 2 mA) than Regress (17 +/- 4 mA) or Sham (16 +/- 3 mA) cats (P < .05). Persistent LVH in the No Regress group was associated with prolongation of epicardial monophasic action potential duration (MAPD) in the left but not the right ventricle. Dispersion of refractoriness was greater in the No Regress group (P < .05 versus Regress or Sham). Regress cats were identical to Sham cats in having a low incidence of inducible polymorphic ventricular arrhythmia, high fibrillation threshold, and MAPD measurements (P = NS versus Sham). CONCLUSIONS: LVH produces multiple electrophysiological abnormalities and increased vulnerability to inducible polymorphic ventricular arrhythmia in this model of LVH. Cats that show regression of hyperthrophy have normal ventricular electrophysiology and have the same low vulnerability to inducible ventricular arrhythmia as Sham animals.

Action Potentials↗

Significance of beliefs and values in predicting fertility and contraceptive behaviour in Pakistan.

A comparative study of 1100 women aged 25-45 years, users and non-users of modern methods of contraception, in the urban centres of Lahore and Faisalabad was conducted in 1991. The objective of the study was to investigate reproductive behaviour and the extent to which social, cultural and attitudinal variables, such as beliefs and values about family life, religiosity and fatalism, influence the fertility decision-making process. Preferences for smaller families were found to be consistently associated with modern attitudes and behaviour towards family and religious values and obligations. Family income, husband's occupation and religiosity offered no explanation of reproductive behaviour. It is concluded that cultural setting and tradition exert an important influence on reproductive behaviour, independent of economic development.

Adult↗

Research utilization in a metropolitan children's hospital.

A model of research utilization directing clinical practice has been described. Clinical practice is conceptualized as a pyramid, with research knowledge forming the base. Department and unit-level activities are designed to promote the identification of research-based practices for incorporation into practice. Practice Committee structures are designed to facilitate the dissemination and utilization of research-based practices. This model has evolved over the past 10 years, and current refinements include movement toward an interdisciplinary focus, support of unit level practice groups, and increased integration of the work of each practice committee.

Child↗

[Information systems for health and social care planning. Information basis and information channels in the municipalities].

The Norwegian Government has started to develop a new system for a better exchange of information between the central and the local authorities when planning health and social services. The plan is to base the system on nationwide collection and delivery of standardized indicators which will signal trends and enable comparisons. Several conclusions from an interview survey indicate that the new information system will not be particularly useful. Local authorities believe that their information is good enough already, and have little confidence in statistics prepared by the central authorities. On the other hand many of them called for more statistics that would enable comparisons between neighbouring municipalities, and several had themselves taken the initiative to collect data on various local needs and activities.

Health Planning↗

The AIDS awareness and sexual behaviour of young people in the South-west of England.

A programme of surveys was undertaken in collaboration with District Health Authorities to assess the AIDS awareness and sexual behaviour of young people, in order to help the development and implementation of HIV/AIDS risk-reduction strategies. Given that the patterns of findings were strongly replicated in the different districts, the data is presented in terms of a combined data set comprising 2955 respondents aged 16-24. The surveys indicate fairly reasonable levels of knowledge about HIV/AIDS but very low personally perceived vulnerability to infection. The sexual culture is one of fairly early ages of first intercourse, moderate levels of partner change and low (one third) levels of condom use. The findings are discussed in terms of their implications for HIV/AIDS risk-reduction strategies.

Acquired Immunodeficiency Syndrome↗