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.     

Induction, Recovery, and Safety Characteristics of Sevoflurane in Children Undergoing Ambulatory Surgery: A Comparison with Halothane

Background: Sevoflurane is an inhalational anesthetic with characteristics suited for use in children. To determine whether the induction, recovery, and safety characteristics of sevoflurane differ from those of halothane, the following open-labeled, multicenter, randomized, controlled, phase III study in children undergoing ambulatory surgery was designed.

Methods: Three hundred seventy-five children, ASA physical status 1 or 2, were randomly assigned in a 2:1 ratio to receive either sevoflurane or halothane, both in 60% N2 O and 40% O2. Anesthesia was induced using a mask with an Ayre's t piece or Bain circuit in four of the centers and a mask with a circle circuit in the fifth center. Maximum inspired concentrations during induction of anesthesia were 7% sevoflurane and 4.3% halothane. Anesthesia was maintained by spontaneous ventilation, without tracheal intubation. End-tidal concentrations of both inhalational anesthetics were adjusted to 1.0 MAC for at least 10 min before the end of surgery. Induction and recovery characteristics and all side effects were recorded. The plasma concentration of inorganic fluoride was measured at induction of and 1 h after anesthesia.

Results: During induction of anesthesia, the time to loss of the eyelash reflex with sevoflurane was 0.3 min faster than with halothane (P < 0.001). The incidence of airway reflex responses was similar, albeit infrequent with both anesthetics. The total MAC *symbol* h exposure to sevoflurane was 11% less than the exposure to halothane (P < 0.013), although the end-tidal MAC multiple during the final 10 min of anesthesia was similar for both groups. Early recovery as evidenced by the time to response to commands after sevoflurane was 33% more rapid than it was after halothane (P < 0.001), although the time to discharge from hospital was similar for both anesthetics. The mean (+/-SD) plasma concentration of inorganic fluoride 1 h after discontinuation of sevoflurane was 10.3+/-3.5 micro Meter. The overall incidence of adverse events attributable to sevoflurane was similar to that of halothane, although the incidence of agitation attributable to sevoflurane was almost threefold greater than that attributable to halothane (P < 0.004).     

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.     

Action of three ectopeptidases on corticotropin-releasing factor: metabolism and functional aspects.

Using purified enzyme preparations, we investigated the actions of angiotensin-converting enzyme, aminopeptidase N, and endopeptidase 24.11 on corticotropin-releasing factor (CRF). The effects of inhibition of these enzymes on CRF action in rat anterior pituitary cultures were also determined. Finally, specific inhibitors were used to evaluate ectopeptidase action on the regional brain metabolism of CRF. K(m) values for CRF were 165, 90, and 42 microM for angiotensin-converting enzyme, aminopeptidase N, and endopeptidase 24.11, respectively. A CRF metabolite profile for each enzyme was determined. In pituitary cultures, inhibition of endopeptidase 24.11 and aminopeptidase N potentiated CRF-stimulated release of adrenocorticotropic hormone (ACTH). In rat pituitary and hypothalamus membrane preparations, specific inhibitor experiments indicated that CRF hydrolysis involved members of the neutral endopeptidase and aminopeptidase enzyme families. In cortex membranes, similar peptidase inhibition was without effect. These data support the hypothesis that ectopeptidases play a major role in CRF metabolism and biological function.