The clinical impact of p16 status in fine-needle aspirates of cervical lymph node metastasis of head and neck squamous cell carcinomas

Lymph node involvement is prognostically the most determinant clinical factor for patients with head and neck squamous cell carcinomas (HNSCCs). Ultrasound of the neck and fine-needle aspiration (FNA) cytology is one of the first diagnostic procedures and the most accurate diagnostic staging tool for the neck. Patients with HPV-positive oropharyngeal carcinomas (OPSCC) show a significantly better prognosis when compared with HPV-negative OPSCC. P16 overexpression is accepted as surrogate marker for HPV-positive in OPSCC. These HPV/p16-positive OPSCC are localized either in the palatal tonsils or the base of tongue and frequently present with lymph node metastases. We analyzed the correlation and reliability of p16 expression of the FNA of the lymph node metastasis with the immunohistochemical expression of p16 of the same lymph node metastasis and its corresponding primary tumor, as it could be of importance for determining the localization and different prognosis of the primary tumor. 54 HNSCC patients were evaluated, p16 expression of the primary tumors and their lymph node metastases correlated precisely. In 25 of the 54 HNSCC patients, a FNA of the lymph node metastases was taken before the treatment. The positive cytological and immunohistochemical p16 staining correlated exactly. Of the 17 histologically p16-negative lymph node metastases 15 FNA were p16-negative, whereas two samples were p16-positive. In our view, a cytological p16 analysis of cervical lymph node metastasis can facilitate the correct localization of the primary tumor and discriminate reliably HPV-positive OPSCC from HPV-negative HNSCC with their significantly diverse prognosis.

Respiratory function during anesthesia: effects on gas exchange

Anaesthesia causes a respiratory impairment, whether the patient is breathing spontaneously or is ventilated mechanically. This impairment impedes the matching of alveolar ventilation and perfusion and thus the oxygenation of arterial blood. A triggering factor is loss of muscle tone that causes a fall in the resting lung volume, functional residual capacity. This fall promotes airway closure and gas adsorption, leading eventually to alveolar collapse, that is, atelectasis. The higher the oxygen concentration, the faster will the gas be adsorbed and the aleveoli collapse. Preoxygenation is a major cause of atelectasis and continuing use of high oxygen concentration maintains or increases the lung collapse, that typically is 10% or more of the lung tissue. It can exceed 25% to 40%. Perfusion of the atelectasis causes shunt and cyclic airway closure causes regions with low ventilation/perfusion ratios, that add to impaired oxygenation. Ventilation with positive end-expiratory pressure reduces the atelectasis but oxygenation need not improve, because of shift of blood flow down the lung to any remaining atelectatic tissue. Inflation of the lung to an airway pressure of 40 cmH2O recruits almost all collapsed lung and the lung remains open if ventilation is with moderate oxygen concentration (< 40%) but recollapses within a few minutes if ventilation is with 100% oxygen. Severe obesity increases the lung collapse and obstructive lung disease and one-lung anesthesia increase the mismatch of ventilation and perfusion. CO2 pneumoperitoneum increases atelectasis formation but not shunt, likely explained by enhanced hypoxic pulmonary vasoconstriction by CO2. Atelectasis may persist in the postoperative period and contribute to pneumonia.

Prospective, paired crossover comparison of multiple, single-needle plateletpheresis procedures with the Amicus and Trima Accel cell separators

BACKGROUND: The Baxter Amicus Version 2.51 (A) and the Gambro BCT Trima Accel Version 5.0 (T) cell separators may produce multiple platelet (PLT) concentrates within a single donation. STUDY DESIGN AND METHODS: The single-needle multiple plateletpheresis procedures of the two devices were compared in a prospective, randomized, paired crossover study in 60 donors. The 120 donations were compared for donor comfort, collection efficiency, residual white blood cell (WBC) count, and (in selected patients) corrected count increment (CCI). RESULTS: The mean PLT yield and the resultant mean number of units per donation were significantly lower for A (6.06 x 10(11) vs. 7.48 x 10(11) and 2.57 vs. 3.19, respectively, both p < 0.001), in spite of a longer apheresis duration (89 min vs. 79 min; p < 0.001). This resulted in a higher collection rate of T (5.68 x 10(11) PLTs/hr vs. 4.10 x 10(11) PLTs/hr, p < 0.001). Residual WBC count of every unit was fewer than 5 x 10(6), but significantly fewer A-PLT donations contained more than 10(5) WBCs per unit (1 vs. 9, p = 0.008). Although the ACD-A consumption was slightly higher for A (489 mL vs. 469 mL, p = 0.04), a trend to a higher frequency of side effects was found for T (42.4% vs. 23.7%, p = 0.06). The 1-hour CCIs of 33 transfused A-PLT units were comparable with those of 43 T-PLT units (11.8 vs. 13.9, p = 0.480). CONCLUSIONS: Both cell separators showed safe collections of up to 4 PLT units per donation with adequate CCI. T produced a higher PLT yield despite shorter apheresis duration, but with slightly higher residual WBC counts and a trend to a higher side-effect frequency.

TA-RE: An Exchange Language for Mining Software Repositories

Software repositories have been getting a lot of attention from researchers in recent years. In order to analyze software repositories, it is necessary to first extract raw data from the version control and problem tracking systems. This poses two challenges: (1) extraction requires a non-trivial effort, and (2) the results depend on the heuristics used during extraction. These challenges burden researchers that are new to the community and make it difficult to benchmark software repository mining since it is almost impossible to reproduce experiments done by another team. In this paper we present the TA-RE corpus. TA-RE collects extracted data from software repositories in order to build a collection of projects that will simplify extraction process. Additionally the collection can be used for benchmarking. As the first step we propose an exchange language capable of making sharing and reusing data as simple as possible.

Changes in respiratory mechanics and gas exchange during the acute respiratory distress syndrome

BACKGROUND: The time course of impairment of respiratory mechanics and gas exchange in the acute respiratory distress syndrome (ARDS) remains poorly defined. We assessed the changes in respiratory mechanics and gas exchange during ARDS. We hypothesized that due to the changes in respiratory mechanics over time, ventilatory strategies based on rigid volume or pressure limits might fail to prevent overdistension throughout the disease process. METHODS: Seventeen severe ARDS patients {PaO2/FiO2 10.1 (9.2-14.3) kPa; 76 (69-107) mmHg [median (25th-75th percentiles)] and bilateral infiltrates} were studied during the acute, intermediate, and late stages of ARDS (at 1-3, 4-6 and 7 days after diagnosis). Severity of lung injury, gas exchange, and hemodynamics were assessed. Pressure-volume (PV) curves of the respiratory system were obtained, and upper and lower inflection points (UIP, LIP) and recruitment were estimated. RESULTS: (1) UIP decreased from early to established (intermediate and late) ARDS [30 (28-30) cmH2O, 27 (25-30) cmH2O and 25 (23-28) cmH2O (P=0.014)]; (2) oxygenation improved in survivors and in patients with non-pulmonary etiology in late ARDS, whereas all patients developed hypercapnia from early to established ARDS; and (3) dead-space ventilation and pulmonary shunt were larger in patients with pulmonary etiology during late ARDS. CONCLUSION: We found a decrease in UIP from acute to established ARDS. If applied to our data, the inspiratory pressure limit advocated by the ARDSnet (30 cmH2O) would produce ventilation over the UIP, with a consequent increased risk of overdistension in 12%, 43% and 65% of our patients during the acute, intermediate and late phases of ARDS, respectively. Lung protective strategies based on fixed tidal volume or pressure limits may thus not fully avoid the risk of lung overdistension throughout ARDS.