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Biomedical subjects

J Calder

Publications and source records attributed to J Calder.

At least 19 recordsLinked to original sources
PubMed2000

Health information provided by retail health food outlets.

Alternative health practices have become increasingly popular in recent years. Many patients visit specific complementary practitioners, while others attempt to educate themselves, trusting advice from employees at local health food stores or the Internet. Thirty-two retail health food stores were surveyed on the nature of the information provided by their staff. A research assistant visited the stores and presented as the mother of a child in whom Crohn's disease had been diagnosed. Seventy-two per cent (23 of 32) of store employees offered advice, such as to take nutritional and herbal supplements. Of the 23 stores where recommendations were made, 15 (65%) based their recommendation on a source of information. Fourteen of the 15 stores using information sources used the same reference book. This had a significant impact on the recommendations; the use of nutritional supplements was favoured. In conclusion, retail health food stores are not as inconsistent as hypothesized, although there are many variances in the types of supplements recommended for the same chronic disease.

Adult↗
PubMed1998

Testing the measurement properties of the Short Form-36 Health Survey in a frail elderly population.

The Short Form-36 Health Survey (SF-36) is a widely used measure of health-related quality of life, however, its suitability for frail older persons is not well documented. This study examines the measurement properties of the SF-36 in a frail older patient population. Patients consecutively admitted to two geriatric services (n = 146) were administered the SF-36 and comparative measures on admission and discharge. Internal consistency (0.75-0.91) and test-retest reliability (0.24-0.80) did not meet standards for clinical application of the tool. Four subscales were moderately correlated with comparative measures (Physical Function 0.53 to -0.76; Bodily Pain -0.61; Vitality -0.58; Mental Health -0.63). The results of effect size, standardized response mean, and relative efficiency statistics were consistent in documenting only minimal change for the SF-36 subscales. The SF-36 appears to be reliable and valid, although its ability to monitor clinical change for frail older patients is questionable.

Activities of Daily Living↗
PubMed1996

Interaction of Lindane Isomers with Chloride Currents in Insect Membranes: Steric Requirements for Channel Modulation and Block

Electrophysiological methods were used to characterize the modulatory effects of hexachlorocyclohexane isomers on GABA-activated chloride currents in dissociated locust neurones. Conductance changes associated with hyperpolarising responses (or outward voltage-clamped currents), evoked by brief GABA pulses, were inhibited by the gamma-isomer at 0.01-1 &mu;M. The antagonistic action was noncompetitive and voltage-independent: the concentration required for half-maximal block was <0.01 &mu;M. The rate of equilibration with the membrane/receptor was inversely proportional to the concentration applied and was not dependent upon agonist-induced channel gating: effects were only partially reversible with extensive washing. In contrast the noninsecticidal beta-isomer was a low-affinity (>/=10 &mu;M) positive modulator of the inhibitory chloride channels. The modulatory action was voltage-dependent (more pronounced for inward currents at hyperpolarised potentials), did not reflect changes in chloride equilibrium potential, and was completely reversible. Nicotinic acetylcholine receptors were consistently antagonised by the beta-isomer at 10 &mu;M. The above results were interpreted by computer-assisted modelling and are discussed in the context of a pharmacophore model for picrotoxinin and convulsant insecticides. The gamma-isomer overlays well with picrotoxinin and a convulsant butyrolactone whereas the beta-isomer and anticonvulsant butyrolactones conform to a different template. Liganding mechanisms and comparative/species differences in chloride channel pharmacology are discussed in the context of potential for development of invertebrate-selective pesticides.

Journal Article↗
PubMed1995

Difficult direct laryngoscopy in patients with cervical spine disease.

Two hundred and fifty three patients were examined before surgery for cervical spine disease. The grade of glottic visibility was determined at direct laryngoscopy, using the classification proposed by Cormack and Lehane. The overall prevalence of difficulty (grades 3 and 4) was 20%. Patients with disease that includes the occipito-atlanto-axial complex have a higher prevalence of difficulty than those with disease below the axis vertebra. Occipito-atlanto-axial disease is associated with poor mandibular protrusion. The best single predictor of difficulty was reduced separation of the posterior elements of the first and second cervical vertebrae on lateral radiographs. The Mallampati examination was the best single predictor on physical examination. The Mallampati may be an indicator of poor cranio-cervical extension. Difficulty was rare in patients with class A mandibular protrusion, and invariable in patients with class C protrusion.

Adolescent↗
PubMed1978

Exacerbations of chronic bronchitis: exogenous or endogenous infection?

Six male patients with chronic bronchitis, who were known previously to have excreted Streptococcus pneumoniae and/or Haemophilus influenzae, both at the times of exacerbations and during remission, were studied for 43 to 52 months. Sputum was examined fortnightly and at the time of exacerbations. Strains of Strep. pneumoniae were serotyped and those of Haemophilus species were typed by antibiograms along with other supporting methods. Sera collected before or at the time of an exacerbation and seven and 30 days afterwards were examined by complement fixation tests against respiratory viruses and Mycoplasma pneumoniae. In 18 out of 25 exacerbations there was evidence of a new type of Strep. pneumoniae and/or Haemophilus spp. or of a current virus infection, suggesting exogenous infection in the majority of these cases. There was a possible reason for failure to detect a new pathogen in three of the seven cases in which none was found. In five further exacerbations adequate investigation was not possible.

Aged↗