Comparison of serum specific IgE antibodies to staphylococcal enterotoxins between atopic children with and without atopic dermatitis

BACKGROUND: The skin of patients with atopic dermatitis (AD) exhibits a striking susceptibility to colonization and infection by Staphylococcus aureus. The exotoxins secreted by S. aureus can act as superantigens and classic allergens, inducing the production of functionally relevant specific IgE antibodies. The aim of this study was to compare the levels and positive rates of serum staphylococcal enterotoxin A (SEA)- and staphylococcal enterotoxin B (SEB)-specific IgE between atopic children with and without AD. METHODS: Sixty children with AD, 55 children with respiratory allergy without AD, and 24 nonatopic healthy children were studied. The levels and positive rates of serum SEA- and SEB-specific IgE were compared among three groups. The correlation between the levels or positive rates of serum SEA/SEB-specific IgE and the severity of AD or the presence of previous skin infections was studied. RESULTS: The children with AD had significantly higher levels and positive rates of serum SEA- and SEB-specific IgE than the atopic children without AD (P < 0.001) and the nonatopic children (P < 0.001). There was no significant difference in the levels and positive rates of serum SEA- and SEB-specific IgE between the atopic children without AD and the nonatopic children. With or without adjustment for the potential confounding effect of total serum IgE levels, the levels and positive rates of serum SEA- and SEB-specific IgE were significantly correlated with severity of AD (P <0.005), but they were not significantly different between AD children with and without previous skin infections. CONCLUSIONS: SEA and SEB may contribute to chronic inflammation and exacerbation of AD through the IgE-mediated immune response.     

Ocular pharmacokinetic models of clonidine-3H hydrochloride

A single topical instillation of clonidine-³H HCl solution (0.2%) was administered to the rabbit eye (30 μl) in order to study the drug's ocular pharmacokinetics. Seven different tissues and plasma were excised and assayed for drug over 180min. By 45–60 min pseudoequilibrium is reached for the cornea, iris/ciliary body, and aqueous humor. Thereafter, drug levels in these tissues decline in parallel. The data are fit separately to a physiological model and a classical diffusion model for which seven ocular tissue compartments and a plasma reservoir are constructed for each model. Clearance terms and distribution equilibrium coefficients are determined from the tissue level data and used as parameters in fitting the mass balance differential equations representing the physiological model. The model parameters can also be fit to a 0.4% single dose. In a separate experiment, a topical infusion technique was designed to provide a constant rate input to the cornea until an apparent steady state was reached in aqueous humor at 55 min. Aqueous humor levels were assayed for clonidine over the infusion and postinfusion periods. The physiological model parameters are fit to the topical infusion data and show good agreement between the predicted and experimental data. The classical model is too complex to fit the data to integrated exponential equations primarily because the method of residuals is inadequate in determining a sufficient set of initial estimates. This is overcome by dividing the eight-compartment model into seven fragmental models, each representing one to five compartments. A stepwise procedure is developed in which initial estimates are obtained for each separate fragmental model and refined. The refined parameter values can then be used as initial estimates for the complex model. Differential equations for the complex model are fit simultaneously to tissue levels representing each compartment. By observation, the classical model fit the data more closely than the physiological model. Statistical moment theory is also applied to the topical infusion data to determine ocular pharmacokinetic parameters for clonidine. The calculated values are: corneal absorption rate constantk _a , 0.00139 min^?1; aqueous humor elimination rate constantk ₁₀ , 0.0658min^?1; mean residence timeMRT _d , 35.6 min; apparent steadystate volume of distributionV _ss, 0.530 ml; and ocular clearanceQ _e , 14.9 =μl/min. The fraction absorbed from the single instillation is estimated as 0.0163.     

Treatment of infants with ureteropelvic junction obstruction: findings from the PURSUIT network

International Urology and Nephrology - Studies based on administrative databases show that infant pyeloplasty is associated with minority race/ethnicity but lack clinical data that may influence...     

Plasma selenium levels and risk of hepatocellular carcinoma among men with chronic hepatitis virus infection.

Both experimental and epidemiologic studies have linked a low dietary intake of selenium with an increased risk of cancer. The authors examined the association between plasma selenium levels and risk of hepatocellular carcinoma (HCC) among chronic carriers of hepatitis B and/or C virus in a cohort of 7,342 men in Taiwan who were recruited by personal interview and blood draw during 1988-1992. After these men were followed up for an average of 5.3 years, selenium levels in the stored plasma were measured by using hydride atomic absorption spectrometry for 69 incident HCC cases who were positive for hepatitis B surface antigen (HBsAg) and/or antibodies against hepatitis C virus (mostly HBsAg positive) and 139 matched, healthy controls who were HBsAg positive. Mean selenium levels were significantly lower in the HCC cases than in the HBsAg-positive controls (p = 0.01). Adjusted odds ratios of HCC for subjects in increasing quintiles of plasma selenium were 1.00, 0.52, 0.32, 0.19, and 0.62, respectively. The inverse association between plasma selenium levels and HCC was most striking among cigarette smokers and among subjects with low plasma levels of retinol or various carotenoids. There was no clear evidence for an interaction between selenium and alpha-tocopherol in relation to HCC risk.     

Roles of oxygen radicals and elastase in citric acid-induced airway constriction of guinea-pigs

Antioxidants attenuate noncholinergic airway constriction. To further investigate the relationship between tachykinin-mediated airway constriction and oxygen radicals, we explored citric acid-induced bronchial constriction in 48 young Hartley strain guinea-pigs, divided into six groups: control; citric acid; hexa(sulphobutyl)fullerenes + citric acid; hexa(sulphobutyl)fullerenes + phosphoramidon + citric acid; dimethylthiourea (DMTU) + citric acid; and DMTU + phosphoramidon + citric acid. Hexa(sulphobutyl)fullerenes and DMTU are scavengers of oxygen radicals while phosphoramidon is an inhibitor of the major degradation enzyme for tachykinins. Animals were anaesthetized, paralyzed, and artificially ventilated. Each animal was given 50 breaths of 4 ml saline or citric acid aerosol. We measured dynamic respiratory compliance (Crs), forced expiratory volume in 0.1 (FEV0.1), and maximal expiratory flow at 30% total lung capacity (Vmax30) to evaluate the degree of airway constriction. Citric acid, but not saline, aerosol inhalation caused marked decreases in Crs, FEV0.1 and Vmax30, indicating marked airway constriction. This constriction was significantly attenuated by either hexa(sulphobutyl)fullerenes or by DMTU. In addition, phosphoramidon significantly reversed the attenuating action of hexa(sulphobutyl)fullerenes, but not that of DMTU. Citric acid aerosol inhalation caused increases in both lucigenin- and t-butyl hydroperoxide-initiated chemiluminescence counts, indicating citric acid-induced increase in oxygen radicals and decrease in antioxidants in bronchoalveolar lavage fluid. These alterations were significantly suppressed by either hexa(sulphobutyl)fullerenes or DMTU. An elastase inhibitor eglin-c also significantly attenuated citric acid-induced airway constriction, indicating the contributing role of elastase in this type of constriction. We conclude that both oxygen radicals and elastase play an important role in tachykinin-mediated, citric acid-induced airway constriction.     

Cytokines predict coronary aneurysm formation in Kawasaki disease patients

In this study, we measured serially the serum levels of cytokines including interleukin-6 (IL-6), IL-8, soluble IL-2 receptor (sIL-2R) and tumour necrosis factor (TNF-) in 60 patients with Kawasaki disease (KD) and evaluated the clinical significance of these cytokines in predicting coronary aneurysm formation. Of the 60 patients, 12 were complicated with coronary aneurysm. Blood samples were collected within the 1st week after onset of fever, then once a week for the 1st month, and once a month for another 5 months. The serum levels of IL-6, IL-8, sIL-2R and TNF were measured using an ELISA or RIA method. Our results show that the changes in serum IL-6 and IL-8 were faster than those of sIL-2R and TNF. Within the 1st week, the serum levels of IL-6 and IL-8 were significantly higher in the patients with than in those without coronary aneurysm (P<0.001). In addition, the serum levels of IL-6 and IL-8 obtained in the 1st week were highly correlated (P<0.001) with those of C-reactive protein and erythrocyte sedimentation rate, and the serum levels of sIL-2R and TNF were also increased at the 1st week reaching the highest level in the 2nd week. In the 2nd week, the serum levels of sIL-2R and TNF were significantly higher in the patients with than in those without coronary aneurysm (P<0.05). These findings suggest that the serum levels of IL-6 and IL-8 obtained in the 1st week may serve as useful parameters in predicting coronary aneurysm formation in KD patients.     

Peripheral angiography: optimal technique and current status in vascular imaging

Angiography is the standard with which new methods of vascular imaging are compared. In this article, selected recent developments affecting the practice of angiography will be discussed. First, a brief review and update of contrast media for intravascular use will be presented. Second, principles and current methods of optimizing the diagnostic arteriogram will be covered with emphasis on the extremities and aorto-femoral angiography. Finally, some of the advantages, limitations, and the role of modern angiography will be discussed.     

Kinetic study of smoking marijuana

Six subjects each smoked a 1% marijuana cigarette and 2 hr later smoked a second one. Plasma levels of delta-9-tetrahydrocannabinol were measured for 9 hr with a radioimmunoassay. Heart rate and self-reported "high" were measured for 2 hr after each cigarette. All three measures showed a rapid increase after the start of smoking with Cmax occurring before the end of smoking. There was a strong correlation between decrease in heart rate and plasma levels from 10 min after smoking until 120 min. All pharmacodynamic response measures returned to baseline values within approximately 2 hr.