Effect of commercial cleansers on skin barrier permeability.

BACKGROUND: Addition of hydrophobically modified polymers (HMPs) to cleansers can reduce the negative impact of surfactant-based cleansers. In this study, the effects of a cleanser containing HMPs, a gentle lotion cleanser (GLC), water, and 1% sodium lauryl sulfate (SLS) on barrier permeability, were evaluated in vitro in pig skin and in vivo in humans. METHODS: Skin stratum corneum (SC) barrier function was quantitated by imaging fluorescence intensity of the sulforhodamine B (SRB) in a pig skin model system using 2-photon and conventional fluorescence confocal microscopy. Solutions containing SRB were applied to pig skin in Franz diffusion cells over a period of 2 h. Penetration of SRB into the skin was monitored from 2 µm to 38 µm. In vivo surfactant/cleanser penetration in human skin was determined using tape stripping. RESULTS: After 2 h, water, 1% SLS, and GLC, significantly increased SRB intensity at all depths measured. SRB intensity was reduced in the HMP-cleanser group compared with other groups at each depth. In vivo, the presence of HMP reduced SLS penetration as measured by tape stripping. CONCLUSION: The cleanser containing HMP prevented changes in SC permeability and surfactant penetration, indicating a protective effect on skin barrier properties.

Strategic leukocyte depletion reduces pulmonary microvascular pressure and improves pulmonary status post-cardiopulmonary bypass.

Cardiopulmonary bypass (CPB) precipitates inflammation that causes marked pulmonary dysfunction. Leukocyte filtration has been proposed to reduce these deleterious effects. Other studies show an improvement with aprotinin. We proposed that a combination of these two therapies would synergistically improve pulmonary outcomes. Two hundred and twenty-five patients participated in a randomized prospective study comparing pulmonary microvascular function and pulmonary shunt fraction postcoronary artery bypass grafting (CABG). The study group underwent leukocyte depletion with aprotinin during the procedure. Pulmonary microvascular function was assessed by pulmonary microvascular pressure (PMVP), a measure of pulmonary capillary edema, and pulmonary function was evaluated by comparing pulmonary shunt fractions. Elevated PMVP and increased pulmonary shunting compromise pulmonary performance. The leukocyte-depleted group had significantly reduced PMVP and pulmonary shunt fraction for at least the first 24 hours postbypass. The combination of strategic leukocyte filtration and aprotinin therapy can effectively reduce postoperative decline in pulmonary function. Cardiopulmonary bypass precipitates a variety of inflammatory effects that can cause marked pulmonary dysfunction to the point of respiratory failure, necessitating prolonged mechanical ventilation. Leukocyte filtration has been investigated previously and appears to be beneficial in improving pulmonary outcome by preventing direct neutrophil-induced inflammatory injury. Recent studies of leukocyte reduction profiles suggest that leukoreduction via leukofiltration is short lived with filter saturation occurring 30-45 minutes after onset of filtration. This phenomenon may explain the limited utility observed with higher risk patients. These patients typically require longer pump runs, so leukocyte reduction capability is suboptimal at the time of pulmonary vascular reperfusion. To more effectively protect the lung from reperfusion injury, leukocyte filtration can be delayed so that reduction of activated neutrophils is maximal at the time of pulmonary vascular reperfusion. It is, thus, conceivable that a timely use of arterial line leukoreducing filters may improve, more substantially, pulmonary function postbypass. Two hundred and twenty-five isolated coronary revascularization patients participated in this prospective, randomized trial. The patients received moderately hypothermic CBP alone (control group: n = 110) or combined with leukocyte depletion, initiated 30 minutes before crossclamp release, with filters placed in the bypass circuit (study group: n = 115). All patients also received full Hammersmith aprotinin dosing during the operation. Pulmonary microvascular pressures were lower in the study group at three hours postbypass, and continued to fall until 24 hours postbypass. In contrast, the control group measured a rise in PMVP and a continued plateau throughout 24 hours postbypass (p < 0.028). The calculated pulmonary shunt fraction also was reduced significantly throughout the study interval, with the greatest reduction occurring approximately three to six hours post-CPB (p < 0.002). Shunt fractions eventually converged at 24 hours postbypass. Outcome measures included hospital charges and length of stay, which were also markedly reduced in the treatment group. Increasing PMVPs are a direct reflection of pulmonary capillary edema, which, in conjunction with increased pulmonary shunt ratio, lead to an overall worsening of pulmonary function. Intraoperative strategic leukocyte filtration combined with aprotinin treatment improves post-CPB lung performance by reducing significantly the reperfusion inflammatory response and its sequelae. These benefits are manifested by reductions in ventilator times, hospital stay and patient morbidity.

Obstructive sleep apnoea.

A patient with obstructive sleep apnoea is described, who required admission to an intensive care unit on two separate occasions within 2 months. The first admission was after anaesthesia for operation on the upper airway. The second occurred after a relative overdose of an opioid analgesic was administered. The diagnosis, treatment and anaesthetic management of patients with this syndrome are discussed.

Expression of specific keratin markers by rabbit corneal, conjunctival, and esophageal epithelia during vitamin A deficiency.

Using an in vivo rabbit model system, we have studied the morphological and biochemical changes in corneal, conjunctival, and esophageal epithelia during vitamin A deficiency. Light and electron microscopy showed that the three epithelia undergo different degrees of morphological keratinization. Corneal and conjunctival epithelia became heavily keratinized, forming multiple layers of superficial, anucleated cornified cells. In contrast, esophageal epithelium underwent only minor morphological changes. To correlate morphological alterations with the expression of specific keratin molecules, we have analyzed the keratins from these epithelia by the immunoblot technique using the subfamily-specific AE1 and AE3 monoclonal antikeratin antibodies. The results indicate that during vitamin A deficiency, all three epithelia express an AE1-reactive, acidic 56.5-kd keratin and an AE3-reactive, basic 65-67-kd keratin. Furthermore, the expression of these two keratins correlated roughly with the degree of morphological keratinization. AE2 antibody (specific for the 56.5- and 65-67-kd keratins) stained keratinized corneal epithelial sections suprabasally, as in the epidermis, suggesting that these two keratins are expressed mainly during advanced stages of keratinization. These two keratins have previously been suggested to represent markers for epidermal keratinization. Our present data indicate that they can also be expressed by other stratified epithelia during vitamin A deficiency-induced keratinization, and suggest the possibility that they may play a role in the formation of the densely packed tonofilament bundles in cornified cells of keratinized tissues.

The effects of stimulation of the left atrial receptors in the cat.

In the cat, distension of the left atrial appendages by means of small balloons resulted in variable changes in the heart rate. Distension of the junctions between the upper two left pulmonary veins and the left atrium resulted in a small but statistically significant increase in the heart rate. Distension did not result in any significant changes in the blood pressure. The increases in heart rate are far less than observed in the dog and it is suggested that the atrial receptors might play a less important role in cardiovascular control in the cat than they do in the dog.