Mycobacterium tuberculosis is one of the most successful human pathogens. Highly virulent strains, which are more easily transmitted than are less virulent strains, elicit variable immune responses. We evaluated the Th1 responses (IFN-γ production) in healthy volunteers after stimulation with various strains. Our results show that the individuals with negative tuberculin skin test (TST) results were not necessarily naive to all of the strains tested, whereas individuals with positive TST results did not respond to all of the strains tested. Drug-resistant strains induced a lower mean level of IFN-γ production than did drug-sensitive strains. One possible practical application of this finding would be for the prediction of responses to treatment, in which it might be advantageous to have knowledge of the estimated IFN-γ production elicited by a specific isolated strain.

Keywords: Tuberculosis; Polymorphism, restriction fragment length; Mycobacterium tuberculosis; Immunity, cellular; Interferon-gamma.

Objective: To describe the characteristics of patients with influenza A (H1N1)-associated pneumonia treated at two hospitals in the region of Liguria, Italy, as well as to describe their treatment and outcomes. Methods: This was a prospective observational study including all patients older than 16 years of age with a confirmed diagnosis of influenza A (H1N1) who were admitted to Villa Scassi Hospital, in the city of Genoa, Italy, or to the Sestri Levante General Hospital, in the city of Sestri Levante, Italy, between September of 2009 and January of 2010. The primary outcome measure was mortality within 60 days after diagnosis. Secondary outcome measures were the need for mechanical ventilation and the length of hospital stay. Results: Of the 40 patients with a confirmed diagnosis of influenza A (H1N1), 27 presented pneumonia during the study period. The mean age of the 27 patients was 42.8 ± 14.8 years, and the mean length of hospital stay was 11.6 ± 8.2 days. Of the 27 patients, 20 had respiratory failure, 4 underwent invasive mechanical ventilation, and 5 underwent noninvasive ventilation. One patient had comorbidities, developed multiple organ failure, and died. Conclusions: During the influenza A (H1N1) pandemic, the associated mortality rate was lower in Italy than in other countries, and cases reported in the country typically had a milder course than did those reported elsewhere. Nevertheless, 9 of our cases (33%) rapidly evolved to respiratory failure, requiring mechanical ventilation.

Keywords: Pneumonia; Influenza A virus, H1N1 subtype; Respiratory insufficiency.

Some lung diseases are true diagnostic challenges due to their various clinical presentations. Actinomycosis is one such disease, potentially affecting various organs and systems. We report the case of a patient with pulmonary actinomycosis as a pseudotumor, which is usually only diagnosed by thoracotomy or thoracoscopy.

Keywords: Actinomycosis; Thoracic neoplasms; Bacterial infections and mycoses.

Here, we describe the case of a 51-year-old female with mediastinal liposarcoma. Liposarcoma is the most common malignant mesenchymal neoplasm in adults, although a mediastinal location is extremely rare. It has a large volume and varied histologic subtypes. It is characterized by the compression of neighboring structures. Computed tomography and magnetic resonance imaging provide useful data for diagnosis. Tissue biopsy and histological typing are very important in determining the treatment and are needed for the final diagnosis. Radiotherapy and chemotherapy are ineffective treatment modalities. According to the literature, surgical resection is the treatment of choice. Long-term follow-up evaluation is indicated since there is a high rate of recurrence.

Keywords: Liposarcoma; Mediastinal neoplasms; Case reports [publication type].