TASK DEFINITION: In this task, you're given a paragraph from the research paper and your task is to generate a suitable title for the research paper based on the given paper. Under 100 words is a good title length.
PROBLEM: We live in a hostile environment, surrounded by microbial pathogens and subject to a range of physical and chemical insults. To survive in this environment, vertebrates have evolved complex immune systems. A key element of this defence is the deployment of rapid response elements at the most probable sites of attack, which are the epithelial-cell boundaries between the body and the environment in the skin, gut and lungs. As the body's largest and most exposed interface with the environment, the skin has a central role in host defence. Before the relatively recent discovery of the immunological defences of skin, the cutaneous interface was viewed as a passive barrier between the host and the hostile environment. In the past few decades, however, it has become apparent that the mechanical aspects of epidermal defence are reinforced by a versatile and robust system of immune surveillance 1 (FIG. 1) . The crucial role of immune surveillance in maintaining homeostasis is evident from the marked increase in the frequency and severity of cutaneous malignancies and infections when immune function is limited, for example in patients with genetic and acquired immunodeficiency disorders and in those receiving immunosuppressive therapy after organ transplantation 2,3 . The regulation of skin defence mechanisms is also crucial, as inappropriate or misdirected immune activity is implicated in the pathogenesis of a large variety of acquired inflammatory skin disorders, including psoriasis, atopic and allergic contact dermatitis, lichen planus, alopecia areata and vitiligo 4-10 . The role of immune dysfunction in these conditions is emphasized by their response to immunosuppressive therapeutic interventions [11] [12] [13] [14] . Understanding the mechanisms of immune surveillance in the skin and tissue-specific immune responses also has important implications for the rational design of vaccines. To promote protective immunity, an immunization protocol must elicit not only an antigenspecific immune response, but also an effective memory response that will provide long-lived protection at the most probable sites of invasion. This applies equally to immunization against infectious organisms, which in most cases invade through the skin or the epithelia of the gastrointestinal or respiratory systems, and to the elicitation of immune responses against tumours. As we discuss, the route and means of adjuvant stimulation that is used can affect the effectiveness and utility of specific vaccine strategies. In this review, we discuss these issues in the context of recent advances in our understanding of cutaneous immune mechanisms, highlighting the interaction of The skin, as the primary interface between the body and the environment, provides the first line of defence against a broad array of microbial pathogens and trauma. In addition to its properties as a physical barrier, the skin has many active defence mechanisms. In this review, we discuss the interaction between the innate and adaptive immune systems in the skin as a model for immune function at epithelial-cell interfaces with the environment. How these mechanisms account for the robust nature of cutaneous immune surveillance and how their dysregulation drives the pathogenesis of inflammatory skin disorders and skin-based tumours are the subjects of this review.

SOLUTION: IMMUNE SURVEILLANCE IN THE SKIN: MECHANISMS AND CLINICAL CONSEQUENCES

PROBLEM: Background. Precise etiologic diagnosis in pediatric community-acquired pneumonia (CAP) remains challenging. Methods. We conducted a retrospective study of CAP etiology in 2 groups of pediatric patients who underwent flexible bronchoscopy (FOB) with bronchoalveolar lavage (BAL); children with acute nonresponsive CAP (NR-CAP; n 5 127) or recurrent CAP (Rec-CAP; n 5 123). Procedural measures were taken to limit contamination risk and quantitative bacterial culture of BAL fluid (significance cutoff point, R10 4 colony-forming units/mL) was used. Blood culture results, serological test results, nasopharyngeal secretion findings, and pleural fluid culture results were also assessed, where available. Results. An infectious agent was detected in 76.0% of cases. In 51.2% of infections, aerobic bacteria were isolated, of which 75.0%, 28.9%, and 13.3% were Haemophilus influenzae, Moraxella catarrhalis, and Streptococcus pneumoniae, respectively. Most (97.9%) of the H. influenzae strains were nontypeable (NTHi). H. influenzae was detected in 26.0% of NR-CAP cases and 51.2% of Rec-CAP cases, whereas Mycoplasma pneumoniae was the predominant pathogen in the NR-CAP group (accounting for 34.9% of cases) but not in the Rec-CAP group (19.3%). Viruses were found in 30.4% of cases, with respiratory syncytial virus, parainfluenzaviruses, and influenzaviruses detected most frequently. Mixed infections were found in 18.9% of NR-CAP cases and 30.1% of Rec-CAP cases. Conclusions. A variety of microorganisms were isolated with frequent mixed infection. NTHi was one of the major pathogens found, especially in association with recurrent CAP, possibly because of improved detection with the FOB with BAL procedure. This suggests that the burden of pediatric CAP could be reduced by addressing NTHi as a major causative pathogen.

SOLUTION: Microbiology of Bronchoalveolar Lavage Fluid in Children With Acute Nonresponding or Recurrent Community-Acquired Pneumonia: Identification of Nontypeable Haemophilus influenzae as a Major Pathogen

PROBLEM: Background Little is known about the prevalence of viral infections in children with community-acquired pneumonia (CAP). Objectives To describe the clinical and virological data collected from children with radiographically confirmed CAP in whom 17 respiratory viruses were sought in respiratory secretion samples during the acute phase of the disease. Patients and methods The study involved 592 children with radiographically confirmed CAP whose respiratory secretion samples were tested using the Luminex xTAG Respiratory Virus Panel Fast assay, which simultaneously detects influenza A virus, influenza B virus, respiratory syncytial virus (RSV)-A and -B, parainfluenzavirus-1, -2, -3, and -4, adenovirus, human metapneumovirus, coronaviruses 229E, NL63, OC43, and HKU1, enterovirus rhinovirus, and bocavirus. A real-time PCR assay was used to identify the rhinovirus in the enterovirus rhinoviruspositive samples. Results A total of 435 children (73AE5%) were positive for at least one virus: the most frequently detected was RSV, which was found in 188 (31AE7%), followed by rhinovirus (n = 144, 24AE3%), bocavirus (n = 60, 10AE1%), influenza viruses (n = 57, 9AE6), and hMPV (n = 49, 8AE2%). Viral co-infections were found in 117 children (19AE7% of the enrolled children; 26AE9% of those with viral infections). Marginal differences were found between the infections owing to a single virus. Co-infections showed radiographic evidence of alveolar pneumonia significantly more frequently than single infections (OR 1AE72, 95% CI 1AE05-2AE81). Conclusions The findings of this study highlight the importance of respiratory viruses (mainly RSV and rhinovirus) in children with CAP and show the characteristics of both the single infections and co-infections associated with the disease.

SOLUTION:
Impact of viral infections in children with community- acquired pneumonia: results of a study of 17 respiratory viruses