Evaluation of percutaneous penetration of natural rubber latex proteins.

Latex allergy is recognized worldwide as a serious health risk. To date, exposure assessment and intervention strategies have focused primarily on respiratory protection; this work evaluates the potential role of dermal protein penetration in the development of latex allergy. In vitro penetration models using flow-through diffusion cells and both human surgical specimens and hairless guinea pig skin (CrL: IAF/HA) demonstrated iodinated latex proteins (ammoniated and non-ammoniated) penetrating into and through both intact and abraded skin. Although less than 1% penetration was observed with intact skin, up to 23% of latex proteins applied to abraded skin were recovered from receptor fluid within 24 h of exposure. Phosphoimaging of the concentrated effluent revealed proteins ranging in size from 3 to 26 kDa. Using a (3)H(2)O penetration assay to evaluate barrier integrity, the amount of latex protein penetration was found to positively correlate with the degree of dermabrasion. Immunohistochemistry of the skin localized latex proteins in the Langerhans cell-rich epidermis and in the dermis. Both in vitro penetration studies and immunohistochemistry supported the use of hairless guinea pig skin as a surrogate for human skin in evaluating latex protein penetration. In studies performed in vivo, 35% of hairless guinea pigs topically exposed to latex proteins (100 microg) 5 days per week for 3 months demonstrated elevations in latex-specific IgG1. The implication for these data is that the skin is not only a plausible route for latex sensitization but can be a major exposure route when the integument has been compromised.     

Effects of CRL 41034 on the adrenergic neuroeffector interaction in the canine saphenous vein

Experiments were designed to determine the effect of CRL 41034, a buflomedil analogue, on the adrenergic responsiveness of canine veins. Rings of saphenous vein (without endothelium) were suspended for isometric tension recording in modified Krebs-Ringer bicarbonate solution at 37 degrees C. CRL 41034 produced a concentration-dependent inhibition of the contractions evoked by the alpha adrenergic agonists norepinephrine, phenylephrine and UK 14304 which was insensitive to the blockade of neuronal uptake by cocaine. CRL 41034 was more potent in inhibiting the concentration-dependent contractions evoked by UK 14304 than those by phenylephrine and the antagonism it caused against the response to UK 14304 fulfilled the criteria for competitivity. CRL 41034, at 10(-5) M significantly depressed, and at 10(-4) M abolished the contractions induced by electrical stimulation of the adrenergic nerves and those evoked by the indirect sympathomimetic amine tyramine. Strips of canine saphenous vein were superfused after incubation with [3H] norepinephrine. During sympathetic nerve activation, CRL 41304 increased the stimulation-evoked overflow of [3H] norepinephrine and 3-methoxy-4-dihydroxyphenylglycol; in the presence of rauwolscine the compound only increased the stimulation-evoked overflow of 3,4-dihydroxyphenylglycol. These experiments suggest that the major vascular effects of CRL 41034 in canine veins are blockade of alpha 2-adrenoceptors on vascular smooth muscle, and inhibition of prejunctional alpha 2-adrenoceptors on adrenergic nerve endings.     

Vascular complications of prolonged intra-aortic balloon counterpulsation in cardiac surgical patients

Background. Use of intra-aortic balloon pump (IABP) is associated with certain vascular complications, which are likely to develop more frequently in patients where IABP is used for prolonged period. The present study was undertaken to analyze vascular complications after prolonged IABP use in patients undergoing various cardiac surgical procedures. Methods. Between January 1995 and February 2001, a total of 1130 patients (7.4% of all adult patients undergoing cardiac procedures) required IABP counterpulsation, out of which 220 patients required IABP for more than 4 days. The vascular complications in these patients were studied. The IABP was inserted by percutaneous technique in 211 (95.5%) patients. The mean age of the patients was 57.5±9.5 years and 15% patients were female. The prevalence of peripheral vascular disease was 11.8%. Results. The duration of IABP therapy ranged from 5 days to 21 days with mean duration of 9.71±4.29 days. A total of 41 complications developed in 38 (17.3%) patients. Acute lower limb ischemia, requiring urgent surgical intervention, was the commonest major complication, which developed in 17 patients. This required thromboembolectomy in 11 patients and femoro-femoral bypass in 3 patients. One patient developed gangrene of the leg, requiring below knee amputation. On multivariate analysis, peripheral vascular disease, preoperative serum creatinine, surgery for LV aneurysm and unstable angina and hemodynamic instability (as the indications for IABP) were found as the predictors of vascular complications. Conclusions. Prolonged use of IABP counterpulsation is associated with significant incidence of vascular complications. Proper assessment of peripheral circulation before IABP insertion and appropriate management of ischemic complications are important to avoid limb loss to the patient.     

Effect of brushing and thermocycling on the shade and surface roughness of CAD-CAM ceramic restorations

Statement of problem

The effects of toothbrushing (B) and thermocycling (TC) on the surface texture of different materials with various fabrication processes have been investigated. However, studies of computer-aided design and computer-aided manufacturing (CAD-CAM) ceramic restorations are limited.

Inflammatory conditions of the eye associated with rheumatic diseases

Ocular inflammation occurs in many patients with systemic rheumatic disease. The best examples are rheumatoid arthritis, juvenile rheumatoid arthritis, temporal arteritis, systemic lupus erythematosus, Wegener’s granulomatosis, polyarteritis nodosa, relapsing polychondritis, and Adamantiades-BehÇet’s disease. Ocular inflammation may precede the symptoms of the systemic disease and can be helpful in systemic diagnosis. After diagnosis, ocular inflammation can mark the severity of the systemic condition. Thus, prompt diagnosis and treatment of inflammatory conditions of the eye are warranted and may be sight- and life-saving.