PubMed Health⌕ Search

Biomedical subjects

David R Cave

Publications and source records attributed to David R Cave.

8 recordsLinked to original sources

Technology Insight: current status of video capsule endoscopy.

Video capsule endoscopy (VCE) is the most recent major practical and conceptual development in the field of endoscopy. The video capsule endoscope-a small, pill-sized, passive imaging device-has been demonstrated to be the pre-eminent imaging device for disorders of the small intestine. The initial use for VCE was to detect the origin of obscure gastrointestinal bleeding. Several other indications have now been justified, or are in the process of evaluation. More than 200,000 of these disposable devices have been used worldwide, with an extraordinarily good safety record: indeed, the device has been approved for use in children as young as 10 years of age. In addition, a double-ended capsule has now been approved for the evaluation of mucosal disease in the esophagus. The now-widespread deployment of the device into gastrointestinal practice in the US and many other countries suggests that VCE has achieved mainstream utility. The development of similar competitor devices, and devices whose movement can be controlled, is in progress.

Endoscopy, Gastrointestinal↗

A prospective study of the diagnostic accuracy of PillCam ESO esophageal capsule endoscopy versus conventional upper endoscopy in patients with chronic gastroesophageal reflux diseases.

INTRODUCTION: Endoscopy is commonly performed to evaluate for suspected or established esophageal diseases including gastroesophageal reflux disease (GERD) and its complications. The newly developed PillCam ESO Esophageal Capsule offers an alternative approach to visualize the esophagus and to evaluate patients with suspected esophageal disease. AIM: Compare the accuracy (specificity, sensitivity, positive predictive value [PPV], and negative predictive value [NPV]) of esophageal capsule endoscopy (ECE) compared with esophagogastroduodenoscopy (EGD) in evaluating patients with GERD. METHODS: A multicenter pivotal trial was conducted at seven sites. The PillCam ESO esophageal capsule is similar to the standard capsule endoscope used for the small bowel but acquires video images from both ends of the device at 2 frames/second/end. A total of 106 patients (93 GERD; 13 Barrett) underwent ECE followed by EGD. ECE videos were evaluated by an investigator blinded to EGD findings. A blinded adjudication committee reviewed all discrepant findings between ECE and EGD. RESULTS: Sixty-six of 106 patients had positive esophageal findings, ECE identified esophageal abnormalities in 61 (sensitivity, 92%; specificity, 95%). The per-protocol sensitivity, specificity, PPV, and NPV of ECE for Barrett esophagus were 97%, 99%, 97%, and 99%, respectively, and for esophagitis 89%, 99%, 97%, and 94%, respectively. ECE was preferred over EGD by all patients. There were no adverse events related to ECE. CONCLUSIONS: ECE is a convenient and sensitive method for visualization of esophageal mucosal pathology and may provide an effective method to evaluate patients for esophageal disease.

Endoscopy, Gastrointestinal↗

Oxalobacter formigenes and its role in oxalate metabolism in the human gut.

Oxalate is ingested in a wide range of animal feeds and human foods and beverages and is formed endogenously as a waste product of metabolism. Bacterial, rather than host, enzymes are required for the intestinal degradation of oxalate in man and mammals. The bacterium primarily responsible is the strict anaerobe Oxalobacter formigenes. In humans, this organism is found in the colon. O. formigenes has an obligate requirement for oxalate as a source of energy and cell carbon. In O. formigenes, the proton motive force for energy conservation is generated by the electrogenic antiport of oxalate(2-) and formate(1-) by the oxalate-formate exchanger, OxlT. The coupling of oxalate-formate exchange to the reductive decarboxylation of oxalyl CoA forms an 'indirect' proton pump. Oxalate is voided in the urine and the loss of O. formigenes may be accompanied by elevated concentrations of urinary oxalate, increasing the risk of recurrent calcium oxalate kidney stone formation. Links between the occurrence of nephrolithiasis and the presence of Oxalobacter have led to the suggestion that antibiotic therapy may contribute to the loss of this organism from the colonic microbiota. Studies in animals and human volunteers have indicated that, when administered therapeutically, O. formigenes can establish in the gut and reduce the urinary oxalate concentration following an oxalate load, hence reducing the likely incidence of calcium oxalate kidney stone formation. The findings to date suggest that anaerobic, colonic bacteria such as O. formigenes, that are able to degrade toxic compounds in the gut, may, in future, find application for therapeutic use, with substantial benefit for human health and well-being.

Animals↗

Hormonal and antihormonal therapy for epistaxis in hereditary hemorrhagic telangiectasia.

OBJECTIVES/HYPOTHESIS: Objectives were to assess available information on hormonal therapy for bleeding in hereditary hemorrhagic telangiectasia (HHT), to determine whether there is a role for hormonal therapy as an initial therapeutic option, and to report the second known case of response in HHT to antihormonal therapy. STUDY DESIGN: Literature review and case report. METHODS: The literature on hormonal and antihormonal therapy for HHT was reviewed. Medical records for the case reported in the present study were evaluated to confirm the diagnosis and assess responses to surgical and nonsurgical treatments. RESULTS: All reports of success using hormonal therapy for HHT-related bleeding were either retrospective or uncontrolled with the exception of two. Anecdotal evidence with high-dose estrogen appeared to show success, but serious side effects have discouraged use. One controlled trial found no benefit for intermediate dose, single-agent estrogen. The other controlled trial appeared to show benefit with low-dose estrogen-progesterone in HHT with gastrointestinal tract bleeding and was supported by an uncontrolled study showing efficacy in epistaxis. The case reported in the present study demonstrated long-term cessation of epistaxis with tamoxifen in a postmenopausal woman. CONCLUSIONS: Systemic estrogen-progesterone at doses used for oral contraception may eliminate bleeding in symptomatic HHT and is a reasonable initial option in fertile women. There is no information on possible effects of lower-dose estrogen-progesterone used in postmenopausal women for hormone replacement therapy. Tamoxifen has dramatically eliminated HHT-related bleeding in two cases. It is well tolerated in postmenopausal women and should be considered for randomized clinical trials.

Drug Administration Schedule↗

Severe isolated Crohn's-like disease of the gastroduodenal tract.

We report four cases of isolated GCD of the stomach and proximal small intestine that were refractory to conventional management. Gastric ulcers were present in patients 1-3 for 4, 13, and 22 years and erosive gastritis in patient 4 was present for at least 2 years. High-dose proton pump inhibition and H. pylori eradication failed to induce healing. Neither ileocolonic lesions nor typical CD pathology with granulomas were detected in any of the patients, but all behaved clinically like CD. The three patients with gastric ulcers failed initial partial gastrectomy and required multiple reoperations because of duodenojejunal ulceration and anastomotic stricture formation. Patient 1 did not improve with infliximab. Patient 2 healed on steroids and infliximab. Patient 3 did not tolerate sulfasalazine and steroids and is currently being treated with 6-mercaptopurine (6-MP). Patient 4 healed on prednisone and 6-MP. We conclude that GCD should be considered in isolated refractory gastroduodenal inflammation and ulceration. Immunomodulators and surgery may play a role in the treatment of this difficult-to-manage condition.

Adult↗