Publications by authors named "Chalmers R"

The application of genotyping to clinical isolates of Cryptosporidium has increased significantly our knowledge and understanding of the distribution and epidemiology of this parasite. However, some methods can be laborious and demand specialist technical expertise. PCR-restriction fragment length polymorphism (RFLP) techniques represent a more rapid and simple method of genotyping to support epidemiological and clinical investigations than conventional DNA analytical techniques.

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This report describes three infants with genetic defects of carnitine-acylcarnitine translocase (CACT), an inner mitochondrial membrane carrier that is essential for long-chain fatty acid oxidation. Two of the patients were of European and Chinese origin; the third was from consanguineous Turkish parents. CACT activity was totally deficient in cultured skin fibroblasts from all three patients.

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Introduction: Although many aspects of hydrogel lens wear have been explored over the last 20 years, little attention has been paid to the role of refractive error magnitude in determining patients' ocular responses or associated contact lens behaviors.

Methods: A cross-sectional study was conducted in 32 optometric and ophthalmologic practices. We enrolled 2161 spherical soft contact lens-wearing patients.

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Purpose: This study characterized ocular symptoms typical of dry eye in an unselected optometric clinical population in the United States and Canada.

Methods: Self-administered dry eye questionnaires, one for non-contact lens wearers (dry eye questionnaire) and one for contact lens wearers (contact lens dry eye questionnaire), were completed at six clinical sites in North America. Both questionnaires included categoric scales to measure the prevalence, frequency, diurnal severity, and intrusiveness of nine ocular surface symptoms.

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IHF or supercoiling is required early in Tn10 transposition, but at later stages they inhibit the reaction in a classic homeostatic loop. We investigated the mechanism of transpososome assembly and regulation using hydroxyl radical DNA protection and interference. We present a three-dimensional molecular model for the IHF-bent end of Tn10 wrapped around a transposase core.

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We report a man with a 3-year-history of a striking eruption of small, 2-3 mm diameter keratotic, crateriform papules distributed symmetrically over the lower limbs. Morphologically the individual papules closely resembled those described in acrokeratoelastoidosis (AK) of Costa and in focal acral hyperkeratosis of Dowd (FAH). The case is unusual, however, in that there was dramatic involvement of the legs but the hands and feet were largely spared.

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Purpose: To measure the limbal vascular response after 8 hours of eye closure while wearing high and low permeability lenses compared to control eyes without lenses.

Method: Twenty neophyte participants wore lotrafilcon A silicone hydrogel lenses (HDk; Dk = 140) or etafilcon A hydrogel lenses (LDk; Dk = 18). On two different nights the lenses were randomly worn for 8 hours during sleep in the right eyes only.

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Chorea-acanthocytosis (CHAC, MIM 200150) is an autosomal recessive neurodegenerative disorder characterized by the gradual onset of hyperkinetic movements and abnormal erythrocyte morphology (acanthocytosis). Neurological findings closely resemble those observed in Huntington disease. We identified a gene in the CHAC critical region and found 16 different mutations in individuals with chorea-acanthocytosis.

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The techniques of enzyme-linked immunosorbent assay (ELISA) and immunoblotting were used to examine a total of 1667 sera, from apparently healthy members of rural communities in England, for antibodies to the lipopolysaccharide (LPS) of Escherichia coli O157 and Verocytotoxins (VT). Twenty-nine sera from 22 individuals were shown to have antibodies specific for E. coli O157 LPS.

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Purpose: The purpose of this study was to determine the impact of extended wear of high and low oxygen permeability (Dk) lenses on the development or resolution of limbal hyperemia and corneal neovascularization in a randomized prospective clinical trial.

Methods: Adapted daily-wear contact lens wearers were randomly assigned to one of two groups. The low-Dk group (N = 23) wore etafilcon A lenses (Dk/t = 40) for up to 7 days and 6 nights, and the high-Dk group (N = 39) wore lotrafilcon A lenses (Dk/t = 175) for up to 30 days and nights.

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Background: The development of bullae accompanying acute oedema is a commonly observed clinical sign but has been rarely reported in the literature.

Objectives: To document the clinical features and increase awareness of this entity.

Methods: Retrospective case note review of 13 inpatient consultation cases seen in two dermatology departments.

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Polymerase chain reaction (PCR)-coupled single-strand conformation polymorphism (SSCP) approaches utilizing nuclear DNA regions of the small subunit (SSU) of ribosomal RNA and heat shock protein 70 gene (HSP70) were established for genotyping Cryptosporidium parvum. The regions were amplified (individually or in a multiplex reaction) by PCR from DNA extracted from oocysts from ruminant or human hosts, then denatured and subjected to electrophoresis in a mutation detection enhancement (nondenaturing) gel matrix. Single-strand profiles produced in SSCP allowed the unequivocal identification/differentiation of the two common (human, 1 and cattle, 2) genotypes of C.

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Background: Recent changes in surgical training in the UK mean that operative experience must be gained more efficiently. However, it is important to demonstrate that improved training opportunities are not associated with inferior patient outcomes. The aim was to examine changes in training in infrainguinal bypass surgery and to compare the outcomes of operations performed by consultants and trainees.

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Signature-tagged mutagenesis (STM) was originally developed by David Holden while studying the filamentous fungus Aspergillus fumigatus. In attempts to define virulence determinants for this pathogenic fungus, candidate factors were selected by reference to previous circumstantial evidence and knowledge of the pathophysiology of the disease. Genes encoding candidate virulence determinants were isolated, disrupted, and the resulting mutants tested in animal models of disease.

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Purpose: Experience with high Dk silicone hydrogel lenses has revealed post-lens debris, which is characterized by the appearance of spherical, translucent particles referred to as "mucin balls." The objectives of this analysis were to characterize the presence of mucin balls, determine whether any ocular characteristic predicts the development of mucin ball debris, and determine whether there is any association between mucin balls and the ocular response to contact lens wear.

Methods: Ninety-two subjects wore lotrafilcon A lenses on an extended wear basis for up to 30 nights and were followed for 6 months.

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The pathogenic bacterium Neisseria meningitidis is an important cause of septicemia and meningitis, especially in childhood. The establishment and maintenance of bacteremic infection is a pre-requisite for all the pathological sequelae of meningococcal infection. To further understand the genetic basis of this essential step in pathogenesis, we analyzed a library of 2,850 insertional mutants of N.

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Two related sibships from an extended family have been observed with the features of the DOOR syndrome. These features included deafness, onychodystrophy, osteodystrophy, microcephaly, and global developmental retardation with progressive blindness. Seizures, which were associated with hypsarrhythmia, were frequent and difficult to control and ultimately were the cause of death in two patients.

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There is little literature on the use of folic acid supplementation in psoriasis patients being treated with methotrexate. Under the auspices of the British Association of Dermatologists we surveyed, using a questionnaire, the use of folic acid supplementation with methotrexate therapy for psoriasis by dermatologists in the UK. Six-hundred and fifteen questionnaires were sent and 153 responses were received (25%).

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Previous reports of patients with 3-hydroxy-3-methylglutaric aciduria have described the occurrence of di-trimethylsilyl (TMS) and tri-TMS derivatives of 3-hydroxy-3-methylglutaric acid on analysis using gas chromatography and mass spectrometry, leading to difficulty in quantification and ambiguity in diagnosis. We have extracted organic acids from the urine of patients with 3-hydroxy-3-methylglutaric aciduria using a variety of procedures. Solvent extraction combined with hydrochloric acid/sodium chloride resulted in production of both di-TMS and tri-TMS derivatives of 3-hydroxy-3-methylglutaric acid and also mono-TMS and di-TMS derivatives of 3-hydroxyisovaleric acid.

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