Ambulatory 24-hour esophageal pH monitoring

If 24-hour esophageal pH monitoring is to be a useful diagnostic tool, it must reliably discriminate gastroesophageal reflux patients despite daily variations in distal esophageal acid exposure. To address this issue, we studied 53 subjects (14 healthy normals, 14 esophagitis patients, and 25 patients with atypical symptoms) with two ambulatory pH tests performed within 10 days of each other. Intrasubject reproducibility of 12 pH parameters to discriminate the presence of abnormal acid reflux was determined. As a group, the parameters of percent time with pH<4 (total, upright, recumbent) were most reproducible (80%). Therefore, a subject was defined as having gastroesophageal reflux disease if at least one of these three values were abnormal. Intrasubject reproducibility for the diagnosis of reflux disease was 89% for the entire sample. Among subsets, the reproducibility was 93% for the normals and esophagitis patients and 84% for the atypical symptom patients. Total percent time with pH<4 was the single most discriminate pH parameter (85%) and nearly equaled that of the three combined parameters (89%). The intrasubject variability of this parameter was determined by the mean ±2sd of the relative differences between the two test results for all 53 subjects. Total percent time with pH<4 may vary between tests by a factor of 3.2-fold or less (218% higher to 69% lower). We conclude: (1) ambulatory 24-hr esophageal monitoring is a reproducible test for the diagnosis of gastroesophageal reflux disease; and (2) the large intrastudy variability in 24-hr total acid exposure may limit this test's usefulness as a measurement of therapeutic improvement.Supported, in part, by Public Health Services Grant AM 34200-01A1 from NIADDIK.     

Development of a reconstructed human skin model for angiogenesis

We have previously shown that reconstructed human skin engineered from autologous keratinocytes, fibroblasts, and sterilized donor allodermis stimulates angiogenesis within 5-7 days when placed on well-vascularized wound beds in nude mice. When this reconstructed skin was used clinically in more demanding wound beds, some grafts were lost, possibly due to delayed vascularization. As this reconstructed skin lacks any endothelial cells, our aim in this study was to develop an angiogenic reconstructed skin model in which to explore strategies to improve angiogenesis both in vitro and in vivo. We report that culture of small-vessel human dermal microvascular endothelial cells (HuDMECs) was achieved using magnetic beads coated with an antibody to platelet cell adhesion molecule as a means of purifying the culture. Keratinocytes, fibroblasts, and HuDMECs could be cultured from the same skin biopsy. Initial studies culturing HuDMECs and other sources of endothelial cells with the tissue-engineered skin showed that these cells were capable of slowly entering the dermis under standard culture conditions in vitro. In conclusion, this provides us with a model in which to explore strategies for improving angiogenesis in vitro and also establishes the culture methodologies for the production of reconstructed skin containing autologous keratinocytes, fibroblasts, and endothelial cells.     

Depression, Night Terrors, and Insomnia Associated With Long-Term Intrathecal Clonidine Therapy

Abstract:   Intraspinal clonidine is an effective adjunct to intrathecal/epidural opioid administration. We report a case of neuropathic pain treated with intraspinal analgesics in which depression, insomnia, and night terrors developed in association with intraspinal clonidine.     

Identification of Risk Factors for Postoperative Nausea and Vomiting in the Perianesthesia Adult Patient

Postoperative nausea and vomiting (PONV) is a common and potentially debilitating complication of surgery. The preoperative assessment of PONV using established risk assessment tools enables the identification of patients at risk and potentially decreases the incidence of PONV in adult surgical patients. The identification of risk factors associated with PONV and the factors that are independent predictors of PONV preoperatively can facilitate the effective prophylactic treatment and management of PONV in adult surgical patients.