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Studies on allergic diseases remain scarce in Lebanon. The aim of the present study was to determine prevalence and characteristics of asthma, allergic rhinitis and eczema among Lebanese school children.The study was cross-sectional in design performed on a convenient sample of 3,115 students (13-14 yr) selected from 13 schools in 5 Lebanese provinces. Students were asked to complete the Arabic version of the International Study of Asthma and Allergies in Childhood questionnaire. Logistic regression was performed to assess the characteristics of having asthma, allergic rhinitis and eczema in the past year.The prevalence of ever having asthma, rhinitis and eczema was 8.3%, 45.2% and 12.8% respectively, while the prevalence of the symptoms of these diseases in the past year was 24.1%, 38.6% and 20.9%, respectively. Residing in the South and the North provinces of Lebanon and living in a busy area increased the likelihood of developing asthma and rhinitis. Higher rates of asthma and eczema, however, was noted among students going to private schools (Odds Ratio (OR) = 1.6, 95% confidence interval (CI): 1.3-2.1 and OR = 1.3, 95% CI: 1.0-1.7, respectively). Passive smoking was significantly associated with asthma only (OR = 1.3, 95% CI: 1.1-1.7). In addition to the above, the odds of having any of the three outcomes increases to at least 2.4-fold when accompanied by another allergic disease.Allergic diseases are highly prevalent in Lebanon and are catching up with the rates of developed countries. Moreover, the role of each of the three diseases in the existence of the other two had the greatest impact on their prevalence.

The study aims to determine the prevalence of eczema among Lebanese adolescents and identify demographic, nutritional and environmental characteristics associated with eczema.A cross-sectional study conducted on a convenient sample of 3 153 students (13-14 years) selected from five different provinces in Lebanon. Significant unadjusted demographic, nutritional and environmental variables were considered in a stepwise regression model.Ever having an itchy rash that lasted for a period more than six months was reported by 788 (25.0%) adolescents, while 404 (12.8%) reported ever having eczema. Females and passive smokers were at 1.5 increased risk of having eczema than their counterparts. Exercising regularly, living near a busy area, and frequent eating of eggs were positively associated with eczema. Finally, adolescents who suffered from allergic diseases, asthma (Odds ratio (OR): 1.64, 95% CI: 1.16-2.32), rhinitis (OR: 1.35, 95% CI: 1.07-1.70) and hay fever (OR: 2.77; 95% CI: 2.12-3.62) also reported having had eczema.Environmental factors were found to play an important role in the prevalence of eczema among adolescents.

Dehydroepiandrosterone has been proposed as a means of restoring immune function after injury. In this study we examined the effect of dehydroepiandrosterone on the impaired immunoglobulin M synthesis and depressed lymphocyte mitogenic responses observed after burn injury. We divided BALB/c mice (n = 28) into four equal groups that received either a 25% total body surface area dorsal steam burn or a sham procedure. One hour later we injected mice subcutaneously either with 100 micrograms dehydroepiandrosterone or vehicle alone. Five days later we isolated splenocytes for assessment of immune function. We stimulated splenocytes with lipopolysaccharide and 5 days later measured immunoglobulin M synthesis specific for peptidoglycan polysaccharide, a ubiquitous bacterial antigen. We stimulated additional cultures with lipopolysaccharide or concanavalin A to measure B- or T-lymphocyte mitogenic response. Burn injury impaired peptidoglycan polysaccharide-specific immunoglobulin M synthesis compared with sham (p < 0.05), and this impairment was not restored by the administration of dehydroepiandrosterone (p < 0.05). Furthermore dehydroepiandrosterone did not correct the burn-induced impairments of B- and T-cell mitogenic responses (p < 0.05). Our study demonstrates that in this model the administration of dehydroepiandrosterone in vivo does not correct the impairments of humoral or cellular immunity induced by burn injury.

Leukotriene B 4 (LTB 4 ) from vascular endothelium may play a key role in the genesis of atherosclerotic lesions. However, the ability of this tissue to synthesize LTB 4 is controversial. To resolve this issue arachidonic acid metabolism was characterized in cultures of confluent monolayers of a rabbit aortic endothelial cell line by use of both high-pressure liquid chromatography and radioimmunoassay. Cells were grown to confluence in Dulbecco's modified Eagle's medium/Ham's F12 with 5% fetal bovine serum. Lipoxygenase activity was studied by placing the cells in Hank's balanced salt solution with 2 μmol/L indomethacin. After 30 minutes preincubation with indomethacin cells were exposed to either arachidonic acid (10 μmol/L) or arachidonic acid labeled with radioactive carbon ( 14 C) (1 μCi; SA 58 mCi/mmol) and then stimulated with 9.5 μmol/L calcium ionophore A23187 for 55 minutes. Studies of the cyclooxygenase activity were performed without preincubating with indomethacin. Samples were prepared for high-pressure liquid chromatography by evaporation to dryness under a vacuum and resuspending in 2 ml of 1:1 methanol/water. Tritium-labeled standards were added before loading the 14 C-labeled samples on the column. Radiolabeled arachidonic acid metabolites were separated by high-pressure liquid chromatography and detected by means of a dual channel flow-through radiodetector that monitors both 14 C and 3 H. Based on coelution with authentic standards three lipoxygenase metabolites of arachidonic acid have been identified: LTB 4 , 12- and 5-hydroxyeicosatetraneoic acid. Leukotriene B 4 was further characterized by ultraviolet spectral analysis and inhibition studies with use of nordihydroguaiaretic acid. Quantitation was facilitated by commercially available radioimmunoassay kits. An average of 600 pg LTB 4 /10 6 cells was measured from separate experiments. Negative controls produced no LTB 4 . These data demonstrate that rabbit aortic endothelial. cells when stimulated with calcium ionophore in the presence of exogenous arachidoric acid synthesize LTB 4 , an inflammatory mediator that may play an important role in the pathogenesis of atheroslcerosis. (J VASC SURG 1990;12:298-304.)

Purpose: Many issues surrounding the management and outcome of carotid artery injuries remain controversial. The purpose of this study was to review a large contemporary experience with such injuries in the setting of designated trauma centers. Methods: A statewide computerized trauma registry was used to identify all patients with injuries to the common or internal carotid arteries from October 1987 to June 1993. The records of 82 such patients were retrieved and analyzed. Results: Overall mortality and stroke rates were 17% and 28%, respectively. Patients presenting with coma or shock had a particularly bad prognosis (50% and 41% mortality, respectively). Internal carotid injuries resulted in mortality and stroke rates of 21% and 41%, respectively, compared with 11% each for common carotid injuries. Patients with blunt injuries had a much higher stroke rate (56% vs 15%) but had lower mortality (7% vs 22%) than did patients with penetrating injuries. Airway compromise and associated injuries did not affect prognosis. Operative repair and percutaneous balloon occlusion had the best survival and functional outcomes. Conclusions: Operative repair offers the best chances for recovery in all categories of patients regardless of injury mechanism. Ligation is useful only as a last-resort lifesaving effort. Shock and neurologic impairment are poor prognostic factors but should not negate repair. (J VASC SURG 1995;21:46-56.)

The relative impact of inhalation injury, burn size, and age on overall outcome following burn injury was examined in 1447 consecutive burn patients over a five and a half year period. The overall mortality for all patients was 9.5% (138 of 1447). The presence of inhalation injury, increasing burn size, and advancing age were all associated with an increased mortality (p < 0.01). The incidence of inhalation injury was 19.6% (284 of 1447) and correlated with increasing percent total body surface area (%TBSA) burn (r = 0.41, p < 0.01) and advancing age (r = 0.15, p < 0.01). The overall mortality for patients with inhalation injury was 31% (88 of 284) compared with 4.3% (50 of 1163) for those without inhalation injury. Using multivariate analysis inhalation injury was found to be an important variable in determining outcome, but the most important factor in predicting mortality was %TBSA burn (accuracy = 92.8%) or a combination of %TBSA burn and patient age (accuracy = 93.0%). Adding inhalation injury only slightly improved the ability to predict mortality (accuracy = 93.3%). The presence of inhalation injury is significantly associated with mortality after thermal injury but adds little to the prediction of mortality using %TBSA and age alone.

True primary venous aneurysms are rare. This is the first report of such an aneurysm involving the lesser saphenous vein. Though most often a medical curiosity, such lesions can result in serious morbidity and even mortality. Because of their rarity they are often misdiagnosed. Salient features pertaining to classification, diagnosis, and treatment are reviewed.

Vascular endothelium has been established as a major source of prostacyclin production. Whether endothelial cells are also capable of synthesizing thromboxane A2 remains controversial. Suppression of such endothelial thromboxane synthesis would be beneficial for short-term patency of vascular grafts. This study examined the production of thromboxane A2 by endothelial cells and its modulation by the calcium-channel blocker nifedipine in vitro. The results indicate that (1) endothelial cells spontaneously secrete thromboxane A2, (2) this production can be enhanced severalfold in the presence of arachidonic acid, and (3) the calcium-channel blocker nifedipine significantly inhibits thromboxane production without demonstrable toxicity to the endothelial cells.

• Increased mortality from sepsis is associated with high levels of thromboxane B 2 (TXB 2 ) and 6-keto-prostaglandin F 1α (PGF 1α ). Linoleic acid, an n-6 essential fatty acid, is the usual precursor of TXB 2 and PGF 1α , while fish oil is rich in n-3 essential fatty acid, the precursor of less active moieties. Rats were fed chow, an essential fatty acid–deficient diet, or an essential fatty acid–deficient diet supplemented with linoleic acid or fish oil for 2 weeks. The animals then underwent a sham operation or cecal ligation and puncture to induce sepsis. Six hours later, blood was obtained for analysis. The chow and linoleic acid diets produced significant (twofold to fivefold) increases in levels of both TXB 2 and PGF 1α after sepsis. The essential fatty acid–deficient diet and fish oil diet protected against increases in levels of TXB 2 or PGF 1α during sepsis. Dietary restriction of linoleic acid or fish oil supplementation may play an important role in altering the inflammatory mediator response to sepsis. ( Arch Surg . 1991;126:179-182)

The objective of this study was to compare the effect of cyclic tension on prostacyclin secretion by venous and arterial endothelial cells. Early passage endothelial cells from bovine aortas and venae cavae were subjected to cyclic deformation (up to 17% elongation and 60 cycles/min). On posttreatment days 3 and 5 a radioimmunoassay was used to assess supernatant fluids from the endothelial cells for prostacyclin activity. The results indicate that in vitro (1) under static or control conditions, venous endothelial cells secrete significantly more prostacyclin (an increase of 1.5- and 4.8-fold on days 3 and 5, respectively) than do arterial endothelial cells isolated from the same animal and (2) prostacyclin secretion by mechanically deformed venous and arterial endothelial cells was significantly less than static control cultures on days 3 and 5. However, prostaglandin I 2 secretion remained at higher levels in cyclically deformed venous endothelial cells than in cyclically deformed arterial endothelial cells. These data suggest that endothelial cells from the vena cava have a greater capacity for prostacyclin secretion than have their aortic counterparts. If these observations are maintained in vivo, greater prostacyclin secretion by venous endothelial cells could represent a homeostatic mechanism aimed at reducing thrombus formation in low-velocity areas of the vasculature. (J Vasc Surg 1989;10:292–8.)

To evaluate the sensitivity of diffusing capacity (DLCO) and pressure-volume (P-V) curves in the detection of emphysema, these tests were compared with pathologic assessment of emphysema in patients undergoing lung resection for a localized tumor, and with the overall extent of emphysema as assessed by computed tomography (CT). The resected lung specimens were fixed in the inflated state and cut at 1-cm intervals in the horizontal plane. The pathologic extent of emphysema was quantitated by comparison with a standard reference panel of emphysema grading. The overall extent of emphysema on CT was assessed by a visual scoring system in a total of 55 patients, 19 undergoing lung resection and 36 not undergoing lung resection. Analysis of 37 patients by pathology scores revealed 18 with no or trivial emphysema (emphysema grades less than or equal to 5; mean grade, 2.2 +/- SD 2.6) and 19 with emphysema (grades greater than or equal to 10; mean grade, 33.2 +/- SD 24.2). Diffusing capacity, the ratio of DLCO to alveolar volume (DLCO/VA), maximal lung elastic recoil (PLmax), and lung elastic recoil at 90% of total lung capacity (PL90) were significantly different between the two groups, whereas K (the exponential constant describing the shape of the P-V curve) was not. The pathology grade of emphysema showed a significant correlation with (DLCO) (r = -0.53) and DLCO/VA (r = -0.55), which was greater than the correlation with PLmax (r = -0.42) and PL90 (r = -0.43).(ABSTRACT TRUNCATED AT 250 WORDS)