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Biomedical subjects

D G Richards

Publications and source records attributed to D G Richards.

At least 19 recordsLinked to original sources
PubMed2006

Nucleon axial charge in full lattice QCD.

The nucleon axial charge is calculated as a function of the pion mass in full QCD. Using domain wall valence quarks and improved staggered sea quarks, we present the first calculation with pion masses as light as 354 MeV and volumes as large as (3.5 fm)3. We show that finite volume effects are small for our volumes and that a constrained fit based on finite volume chiral perturbation theory agrees with experiment within 7% statistical errors.

Journal Article↗
PubMed2004

Endoscopic placement of fibrin sealant as a treatment for a long-standing Boerhaave's fistula.

A 64-year-old man suffered a spontaneous rupture of the esophagus (Boerhaave's syndrome) after an episode of severe retching. He underwent attempted primary repair of the esophageal defect, but unfortunately the repair failed with the development of a persistent esophago-bronchial fistula resistant to extended conservative management. Three hundred and nineteen days after the initial rupture, the fistula was successfully treated with endoscopic placement of fibrin glue. We believe this to be the first reported case of fibrin sealant being used in the treatment of a long-standing fistula resulting from Boerhaave's syndrome.

Bronchial Fistula↗
PubMed2003

Objective evaluation of ERCP procedures: a simple grading scale for evaluating technical difficulty.

BACKGROUND: and objective: Endoscopic retrograde cholangiopancreatography (ERCP) is a technically demanding endoscopic procedure that varies from a simple diagnostic to a highly complex therapeutic procedure. Simple outcome measures such as success and complication rates do not reflect the competence of the operator or endoscopy unit, as case mix is not taken into account. A grading scale to assess the technical difficulty of ERCP can improve the objectivity of outcome data. METHODS: A I to IV technical difficulty grading scale was constructed and applied prospectively to all ERCPs over a 12 month period at a single centre. The procedures were performed by two senior trainees and two experienced consultants (trainers). The grading scale was validated for construct validity and inter-rater reliability at the end of the study using the chi(2) test and kappa statistics. RESULTS: There were 305 ERCPs in 259 patients over the 12 months study period (males: 112, females: 147, age range 17-97, mean 70.3 years). There was overall success in 244 (80%) procedures with complications in 13 (4%): bleeding in five (1.6%), cholangitis in one (0.3%), pancreatitis in five (1.6%), and perforation in two (0.7%). Success rate was highest for grade I, 49/55 (89%), compared with grade IV procedures, 8/11 (73%). There was a significant linear trend towards a lower success rate from grade I to IV (p=0.021) for trainees, but not for trainers. Complications were low in grade I, II, and III procedures, 12/295(4%), compared with grade IV procedures, 1/11(9%). The inter-rater reliability for the grading scale was good with a substantial agreement between the raters (kappa=0.68, p<0.001). CONCLUSION: Success and complications of ERCP by trainees are influenced by the technical difficulty of the procedure. Outcome data incorporating a grading scale can give accurate information when auditing the qualitative outcomes. This can provide a platform for structured objective evaluation.

Adolescent↗
PubMed2001

Manual medicine diversity: research pitfalls and the emerging medical paradigm.

Recent studies published in leading medical journals have concluded that chiropractic treatment is not particularly helpful for relieving asthma and migraine symptoms because even though study participants showed notable improvement in symptoms, those subjects who received sham manual medicine treatments also showed improvement. Yet the sham treatment received by control groups in these studies is reminiscent in many ways of traditional osteopathic manipulation. This seems to represent not only a failure to recognize the value of many manual medicine techniques but also an ignorance of the broad spectrum of manual medicine techniques used by various practitioners, from osteopathic physicians to chiropractors to physical therapists. Such blind spots compromise research methodology with regard to manual medicine studies, which could, in turn, diminish the role of manual medicine in clinical practice. Osteopathic manipulative treatment provides an excellent model for recognizing and integrating the full range of manual medicine techniques into research and clinical applications because of the wide range of techniques employed. The potential exists for these techniques to contribute much to medical research and clinical practice--provided that osteopathic physicians and other manual medicine practitioners work to alleviate ignorance about the efficacy of various forms of manipulation.

Asthma↗
PubMed2001

Long-term inhibition of tinnitus by UltraQuiet therapy: preliminary report.

Masking of tinnitus by noise can produce residual inhibition, a persistence in the reduction in tinnitus after the noise is removed. Typically, this relief is very short-lived, on the order of minutes. This report highlights long-term inhibition of tinnitus by UltraQuiet therapy, a new technique that employs patterned sound in the 10- to 20-kHz range, presented through bone conduction. Nine subjects participated in a study of the efficacy of this tinnitus suppression technique. Eight reported improvement in tinnitus symptoms; one did not complete the study. The duration of the improvement ranged from days to weeks. This long-term inhibition may involve a truly plastic change in the brain at the central level.

Adult↗
PubMed2000

Single-strand restriction fragment length polymorphism analysis of the second internal transcribed spacer (ribosomal DNA) for six species of Eimeria from chickens in Australia.

Species of Eimeria from chickens from Australia were characterised using a polymerase chain reaction-linked restriction fragment length polymorphism (PCR-RFLP) approach. The ribosomal DNA region spanning the second internal transcribed spacer (ITS-2) was amplified from genomic DNA by PCR, digested separately with three restriction endonucleases (CfoI, Sau3AI and TaqI) and the fragments separated by denaturing gel electrophoresis. The PCR products amplified from the six species varied from approximately 70 to 620 bp on agarose gels, with differences in size and number of bands among species, but no apparent variation within a species. The PCR-RFLP analysis of ITS-2 amplicons on denaturing gels gave characteristic profiles for individual species (except for minor variation in profiles within some species). The results indicate that ITS-2 contains useful genetic markers for the identification of six Eimeria species occurring in Australia.

Animals↗
PubMed2000

Diffuse esophageal leiomyomatosis: another cause of pseudoachalasia.

The patient was a 22-year-old woman who had presented in early childhood with gastroesophageal reflux and who subsequently underwent surgery. It was commented upon by the surgeons at that time that the esophagus was abnormally thickened. The patient subsequently presented during her first pregnancy with a vulval tumor, which proved histologically to be a leiomyoma. She was also found to have a grossly dilated esophagus and was thought to have achalasia. However, endoscopic ultrasound imaging showed gross hypertrophy of the mid- and distal esophageal wall, with only mild symptoms of dysphagia, which had been long-standing. The appearance of the esophagus was consistent with diffuse esophageal leiomyomatosis. In view of the associated vulval leiomyoma, the patient demonstrated esophagovulvar syndrome.

Adult↗
PubMed2000

Endoscopic ultrasound in the staging of tumours of the oesophagus and gastro-oesophageal junction.

BACKGROUND: Modern management of upper gastro-intestinal cancer demands accurate pre-operative staging. In continental Europe and Japan, endoscopic ultrasound (EUS) is established as the investigation of choice for local staging of these cancers, but British experience with this technique is limited. METHODS: A retrospective review of the medical records of patients with oesophageal or gastro-oesophageal junction tumours during our first 3.5 years' experience with EUS was undertaken and the findings at EUS correlated with the pathology of the resected specimen. RESULTS: A total of 124 patients (86 males), with a mean age of 64.5 years, underwent EUS: 84 had adenocarcinoma and 26 squamous cell carcinoma. There were 3 failed EUS examinations, 42 patients did not have surgery for a variety of reasons, and 10 patients had pre-operative chemoradiotherapy. In the remaining 69 patients, correlation for T stage showed an accuracy of EUS of 80% and for N staging of 54% overall. Comparison of the initial 2 years with the final 18 months showed no change in the T staging accuracy but an improvement in the N staging accuracy from 50% to 60%. CONCLUSION: Once initial experience has been gained, EUS is an accurate procedure for T and N staging of tumours of the oesophagus and gastro-oesophageal junction. It should be included with other imaging modalities, such as CT scanning, in the pre-operative assessment of these tumours.

Adenocarcinoma↗
PubMed1999

The abdominal brain and enteric nervous system.

Conventional medical treatment for neurologic disorders such as epilepsy, migraine, and autism focuses on the brain. Although standard medical treatment is often helpful, the underlying causes of these disorders are not well understood. Furthermore, some individuals respond poorly or not at all to regular medicine. Evidence is accumulating in the medical literature that the enteric nervous system (ENS)-that part of the nervous system associated with the alimentary canal-also plays a role in these disorders. Historically, the concept of an autonomous abdominal nervous system was advocated by Byron Robinson, Johannis Langley, and Edgar Cayce. The work of these three prominent historical figures is considered along with modem view-points on the abdominal nervous system. Complementary therapies that address the nervous system of the abdomen have potential as useful adjuncts to conventional treatment for certain neurologic disorders.

Abdomen↗
PubMed1990

Laxatives prior to small bowel follow-through: are they necessary for a rapid and good-quality examination?

Fifty-six patients undergoing small bowel follow-through examination were randomly allocated to two groups to assess the effect of preparation with laxative on the speed and quality of the examination. We found that laxative had no effect on either speed of the examination or quality of visualization of small bowel. However, the latter was dependent on the degree of supervision and technique of the examining radiologist.

Barium Sulfate↗
PubMed1988

Colorectal polyps: a correlation of radiological and pathological findings.

Ninety colorectal polyps seen on double contrast barium enema were reviewed and note was made of surface and base characteristics, size, site and the presence of associated disease. Results were then correlated with the histology. The radiological characteristics of each histological type of polyp encountered are described. Because of the variation in radiological appearance of each histological type and similarities in appearance between these types, we conclude that radiology cannot accurately predict the histology of a colorectal polyp.

Adult↗
PubMed1988

Cow's milk protein/soy protein allergy: gastrointestinal imaging.

Positive radiologic findings were identified in the small and large bowels in three infants with various gastrointestinal manifestations of cow's milk protein/soy protein allergy, which was diagnosed on the basis of clinical features and histologic findings. Small bowel findings were thickened valvulae conniventes (plicae circulares), a ribbon-like ileum, and a thickened bowel wall. Narrowing, thumbprinting, and spasm were seen in the large bowel. These cases were seen at intervals far enough apart to exclude an endemic infection. The diagnosis of food protein allergy should be considered when diffuse small bowel disease or colitis is identified in an infant.

Dietary Proteins↗
PubMed1986

Effect of volume of water taken with diazepam tablets on absorption.

Thirty-three patients received either 10 ml (group A) or 50 ml (group B) of water with diazepam tablets as premedication while in the supine position. Plasma diazepam concentrations were measured, a delay in the attainment of the peak plasma concentration being taken as an indication of delayed absorption and oesophageal hold-up. There was no difference between the two groups, although in an important minority (16.7% (group A) and 20% (group B], absorption was delayed to beyond 60 min. There was a wide scatter of plasma diazepam concentrations in both groups. Dysphagia during swallowing did not appear to delay absorption.

Absorption↗