Skin Changes Due to Massive Weight Loss: Histological Changes and the Causes of the Limited Results of Contouring Surgeries.

PURPOSE: Outcomes of body contouring surgeries in patients who previously had obesity are limited because of the loss of skin quality. This study aimed to evaluate the morphometric characteristics of collagen and elastic fibers of the skin in the abdominal epigastric region of patients who had massive weight loss following bariatric surgery and compared such with the skin characteristics of patients with morbid obesity. METHODS: This observational study compared skin fragments from the epigastric region of 20 patients who had massive weight loss due to bariatric surgery and 20 patients with morbid obesity. The morphometric analysis was performed on the collagen system using the Picrosirius/polarized light method and on the elastic system using the Weigert's resorcin-fuchsin method. RESULTS: Reduction of thick collagen fibers (p = 0.048), increased thin collagen fibers (p = 0.0085), and increased elastic fiber density (p < 0.001) were observed in the massive weight loss group. No differences were found between the groups regarding mean age (p = 0.917) and total amount of collagen fibers (p = 0.3619). Structural dermis alterations in the massive weight loss group demonstrated collagenous remodeling, with consequent reduction of thick, organized, structured, and directed fibers in favor of thin, misaligned, and loosely arranged fibers. Weight loss was also associated with increased skin elasticity. CONCLUSION: The morphometric changes in the collagen and elastic system scientifically explained the already established clinical perception of cutaneous alterations in patients who had massive weight loss following bariatric surgeries.

Lung pathology in fatal novel human influenza A (H1N1) infection.

RATIONALE: There are no reports of the systemic human pathology of the novel swine H1N1 influenza (S-OIV) infection. OBJECTIVES: The autopsy findings of 21 Brazilian patients with confirmed S-OIV infection are presented. These patients died in the winter of the southern hemisphere 2009 pandemic, with acute respiratory failure. METHODS: Lung tissue was submitted to virologic and bacteriologic analysis with real-time reverse transcriptase polymerase chain reaction and electron microscopy. Expression of toll-like receptor (TLR)-3, IFN-gamma, tumor necrosis factor-alpha, CD8(+) T cells and granzyme B(+) cells in the lungs was investigated by immunohistochemistry. MEASUREMENTS AND MAIN RESULTS: Patients were aged from 1 to 68 years (72% between 30 and 59 yr) and 12 were male. Sixteen patients had preexisting medical conditions. Diffuse alveolar damage was present in 20 individuals. In six patients, diffuse alveolar damage was associated with necrotizing bronchiolitis and in five with extensive hemorrhage. There was also a cytopathic effect in the bronchial and alveolar epithelial cells, as well as necrosis, epithelial hyperplasia, and squamous metaplasia of the large airways. There was marked expression of TLR-3 and IFN-gamma and a large number of CD8(+) T cells and granzyme B(+) cells within the lung tissue. Changes in other organs were mainly secondary to multiple organ failure. CONCLUSIONS: Autopsies have shown that the main pathological changes associated with S-OIV infection are localized to the lungs, where three distinct histological patterns can be identified. We also show evidence of ongoing pulmonary aberrant immune response. Our results reinforce the usefulness of autopsy in increasing the understanding of the novel human influenza A (H1N1) infection.