Nitric oxide (NO) and reactive oxygen species (ROS) play important physiologic roles as mediators of signaling processes. However, high concentrations of NO and ROS result in damage to cellular and extracellular components. Excessive production of endogenous and/or exogenous ROS and NO is implicated in the pathogenesis of lung cancer. NO and its metabolites interact with ROS to generate potent nitrating agents leading to protein nitration, which is one of the several chemical modifications that occur during oxidative/nitrosative stress. Although there is considerable evidence in support of a role for NO in protein modifications and carcinogenesis, recent data suggest that NO has antagonistic cellular effects, leading to either promotion or inhibition of tumor growth. However, the role of NO in tumor biology is still poorly understood. This review demonstrates the role of NO and its metabolites as potential markers in lung cancer.

Allergen-specific immunotherapy is aimed at modifying the natural history of allergy by inducing tolerance to the causative allergen. In its traditional, subcutaneous form, immunotherapy has complete evidence of efficacy in allergic asthma. However, subcutaneous immunotherapy (SCIT) has a major flaw in side effects, and especially in possible anaphylactic reactions, and this prompted the search for safer ways of administration of allergen extracts. Sublingual immunotherapy (SLIT) has met such need while maintaining a clinical efficacy comparable to SCIT. In fact, the safety profile, as outlined by a systematic revision of the available literature, was substantially free from serious systemic reactions. A number of meta-analyses clearly showed that SLIT is effective in allergic rhinitis by significantly reducing the clinical symptoms and the use of anti-allergic drugs, while the efficacy in allergic asthma is still debated, with some meta-analyses showing clear effectiveness but other giving contrasting results. Besides the efficacy on symptoms, the preventive activity and the cost-effectiveness are important outcomes of SLIT in asthma. The needs to meet include more data on efficacy in house dust mite asthma, optimal techniques of administration and, as previously done with SCIT, introduction of adjuvants able to enhance the immunologic response and use of recombinant allergens.

Glucocorticoids are the mainstay of asthma therapy. They are primarily used to suppress airway inflammation, which is the central pathological change in asthmatic patients' airways. This is achieved by many different mechanisms. The classical mechanism is by suppression of the genetic transcription of many inflammatory cytokines that are key in asthma pathophysiology (transrepression). On the other hand, the transcription of certain inhibitory cytokines is activated by glucocorticoids (transactivation), a mechanism that also mediates many of the adverse effects of glucocorticoids. The onset of action through these mechanisms is often delayed (4-24 hours). Other mechanisms mediated through non-genomic pathways are increasingly appreciated. These are delivered in part by binding of glucocorticoids to nonclassical membrane-bound glucocorticoid receptors or by potentiating the a1-adrenergic action on the bronchial arterial smooth muscles, in addition to other mechanisms. These effects are characterized by their rapid onset and short duration of action. Understanding these different mechanisms will help in the development of new and better drugs to treat this common disease and to develop new improved strategies in our approach to its management. Here, the genomic and non-genomic mechanisms of actions of glucocorticoids in asthma are briefly reviewed, with special emphasis on the current updates of the non-genomic mechanisms.

Objective : Increase in reactive oxygen metabolites (ROM) and free radicals is an important cause of cell injury. In this study, we investigated whether determination of ROM in pleural fluids of patients with malignant and non-malignant pleural effusions can be used as a tumor marker indicating malignant effusions in the differential diagnosis. Methods :Sixty subjects with exudative pleural effusion and 25 healthy individuals as the control group were included in the study. Of the subjects with pleural effusion, 50% were malignant and 50% were non-malignant. ROM was studied in the pleural fluids and sera of the subjects with pleural effusion and in the sera of those in the control group. The ROM values of smokers and non-smokers were compared in each group. The Student's t-test and the Mann-Whitney U test were used in order to detect differences between groups for descriptive statistics in terms of pointed features. The statistical significance level was set at 5% in computations, and the computations were made using the SPSS (ver.13) statistical package program. Results : It was determined that the difference between the ROM values of subjects with malignant and non-malign pleural effusions and the sera of the control group was significant in the malignant group compared to both groups (P = 0.0001), and the sera ROM values of patients with non-malignant pleural effusion were significant compared to the control group (P = 0.0001), and the ROM values of smokers were significant compared to non-smokers in each of the three groups (P = 0.0001). Conclusion : These findings indicate that sera ROM levels are increased considerably in patients with exudative effusions compared to that of the control group. This condition can be instructive in terms of serum ROM value being suggestive of exudative effusion in patients with effusions. Furthermore, the detection of pleural ROM values being significantly higher in subjects with malignant pleural effusions compared to non-malignant subjects suggests that ROM can be used as a tumor marker in the differential diagnosis of pleural effusions of unknown origin.

Background: Tobacco consumption is associated with considerable negative impact on health. Health professionals, including future doctors, should have a leading role in combating smoking in the community. Objectives: The aims of the study were to assess the prevalence of smoking among medical students of newly established medical colleges in Riyadh city, the capital of Saudi Arabia, as well as to assess students' attitude, practice and their knowledge on the risk factors of tobacco consumption. Methods: A cross-sectional, questionnaire-based study of students from two medical colleges in Riyadh, Saudi Arabia was carried out. The questionnaire used was anonymous, self-administered and developed mainly from Global Adult Tobacco Survey (GATS). Results: A total of 215 students participated in this study. Forty students (19%) indicated that they smoke tobacco at the time of the study. All of them were males, which raise the prevalence among male students to 24%. Tobacco smoking was practiced by males more than females (P value <0.0001) and by senior more than junior students (<0.0001). About 94% of the study sample indicated that smoking could cause serious illnesses. About 90% of the students indicated that they would advice their patients to quit smoking in the future and 88% thought that smoking should be banned in public areas. Forty-four students (20%) thought that smoking has some beneficial effects, mainly as a coping strategy for stress alleviation. Conclusion: Despite good knowledge about the hazards of tobacco consumption, about 25% of the medical students in this study continue to smoke. The main reported reasons should be addressed urgently by policy-makers. Special efforts should be taken to educate medical students on the effective strategies in managing stress during their study as they thought that tobacco smoking could be used as a coping strategy to face such a stress.

Objective : To investigate the prevalence of Beijing genotype strains of Mycobacterium tuberculosis in the Kingdom of Saudi Arabia. Methods : We analyzed the available data on a total of 1505 strains isolated during 2002-2005. Results : Spoligotyping results revealed that Beijing family isolates represented 4.5% of all the isolates. Existence of Beijing clade is alarming as this family is known to be multi-drug resistant and transmissible. Conclusions : This study showed that the occurrence of Beijing genotype is associated with young age and drug resistance. The Beijing strains affected both Saudi nationals as well as migrants originating in Asia. The Beijing clade could be responsible for the ongoing transmission of tuberculosis within the community.

Objective : Gefitinib, a small molecule tyrosine kinase inhibitor, showed a substantial effect as a salvage treatment for patients with advanced non-small cell lung cancer (NSCLC) who had failed prior chemotherapy. Subsequent phase III trials in previously untreated patients have failed to demonstrate such benefit. It was later reported that gefitinib had a positive outcome when used in selected population. Rational : The inconsistent results and the lack published meta-analysis that systematically examined the overall efficacy of gefitinib in the frontline setting in such patients, have prompted the current meta-analysis. Methods : We selected for analysis only those randomized, peer-reviewed clinical studies where the efficacy of gefitinib-based therapy (GBT) was investigated in chemotherapy naοve patients with locally advanced or metastatic NSCLC. We also included studies where patients were randomized between gefitinib vs. placebo or none after initial chemoradiation or chemotherapy induction offered to all included patients. Results : We identified seven eligible studies involving 2,646 and 1,939 patients randomized to GBT and to control arms, respectively. In mostly unselected population, GBT was not associated with higher objective response rate (ORR), progression-free survival (PFS) (hazard ratio [HR] = 0.97, 95% CI: 0.78-1.20, P = 0.78), or overall survival (OS) (HR = 1.04, 95% CI: 0.95-1.13, P = 0.45) as compared with control interventions. In a fraction of patients with known EGFR mutation status, GBT showed significantly higher ORR among patients with mutant EGFR (odds ratio [OR] = 2.81, 95% CI: 1.71-4.62, P < 0.0001); however, EGFR mutation was not associated with better PFS or OS with GBT. Nevertheless, patients receiving GBT experienced significant improvement in quality of life as compared with those in the control arms. Conclusion : We conclude that GBT cannot be recommended for frontline management of patients with advanced NSCLC in unselected patient population.

Aim: The aim of this study was to investigate the relationship among plasma leptin, ghrelin, adiponectin, resistin levels, and obstructive sleep apnea syndrome (OSAS). Methods: Fifty-five consecutive newly diagnosed OSAS patients and 15 age-matched nonapneic controls were enrolled in this study. After sleep study between 8:00 AM and 9:00 AM on the morning, venous blood was obtained in the fasting state to measure ghrelin and adipokines. Results: Serum ghrelin levels of OSAS group were significantly (P < 0.05) higher than those of the control group. No significant difference was noted in the levels of leptin, adiponectin, and resistin in OSAS group when compared to controls. There was a significant positive correlation between ghrelin and apnea-hypopnea index (AHI) (r = 0.237, P < 0.05) or the Epworth sleepiness scale (ESS) (r = 0.28, P < 0.05). There was also a significant positive correlation between leptin and body mass index (r = 0.592, P < 0.0001). No significant correlation was observed between leptin, adiponectin, resistin, and any polysomnographic parameters. Conclusion : Our findings demonstrated that serum ghrelin levels were higher in OSAS patients than those of control group and correlated with AHI and ESS. Further studies are needed to clarify the complex relation among OSAS, obesity, adipokines, and ghrelin.

Ventriculo-pleural shunt (VPLS) is an acceptable alternative in the management of hydrocephalus. Imbalance between the production and absorption of cerebrospinal fluid an lead to formation of pleural effusion in patient with VPLS and on occasion produce symptoms. Pleural effusion could be a transudate or a non-specific exudate. We report our experience with this modality in relation to formation of pleural effusion and review the literature to make recommendation for its management. Information related to patients' demographics, smoking history, prior pulmonary and occupational history, indication, duration and complications of the VPLS and their management was gathered to substantiate current recommendation with our experience.

We describe an unusual case of lymphocytic pleural effusion associated with the use of cilazapril, a novel angiotensin-converting-enzyme inhibitor (ACEI). An 80-year-old male was prescribed cilazapril for hypertension. He subsequently presented with right chest pain and dry cough. He was found to have a lymphocytic pleural effusion on thoracentesis. Extensive workup, including open pleural biopsy, failed to reveal the etiology of the effusion. However, soon after the withdrawal of cilazapril, his clinical symptoms improved and the effusion disappeared. ACEI-induced pleural effusion has only been rarely reported. Drug-induced pleural effusion should be considered when formulating the differential diagnosis in a patient receiving ACEI.

We report the case of an elderly female patient who presented with dangerous space emphysema occurring after a dental procedure. This case presented a diagnostic and management dilemma because of the development of an unusual complication of dental disease. In our review of the medical literature, we were unable to find any cases with similar manifestations and clinical courses.