F/OH ratio in a rare fluorine-poor blue topaz from Padre Paraíso (Minas Gerais, Brazil) to unravel topaz's ambient of formation.

Topaz [Al2SiO4(F,OH)2] is one of the main fluorine-bearing silicates occurring in environments where variably acidic (F)/aqueous (OH) fluids saturate the silicate system. In this work we fully characterized blue topaz from Padre Paraíso (Minas Gerais, Brazil) by means of in situ synchrotron X-Ray and neutron powder diffraction measurements (temperature range 298-1273 K) combined with EDS microanalyses. Understanding the role of OH/F substitution in topaz is important in order to determine the hydrophilicity and the exchange reactions of fluorine by hydroxyl groups, and ultimately to characterize the environmental redox conditions (H2O/F) required for mineral formation. The fluorine content estimated from neutron diffraction data is ~ 1.03 a.f.u (10.34 wt%), in agreement with the chemical data (on average 10.0 wt%). The XOH [OH/(OH + F)] (0.484) is close to the maximum XOH value (0.5), and represents the OH- richest topaz composition so far analysed in the Minas Gerais district. Topaz crystallinity and fluorine content sharply decrease at 1170 K, while mullite phase starts growing. On the basis of this behaviour, we suggest that this temperature may represent the potential initial topaz's crystallization temperature from supercritical fluids in a pegmatite system. The log(fH2O/fHF)fluid (1.27 (0.06)) is coherent with the fluorine activity calculated for hydrothermal fluids (pegmatitic stage) in equilibrium with the forming mineral (log(fH2O/fHF)fluid = 1.2-6.5) and clearly different from pure magmatic (granitic) residual melts [log(fH2O/fHF)fluid < 1]. The modelled H2O saturated fluids with the F content not exceeding 1 wt% may represent an anomalous water-dominant / fluorine-poor pegmatite lens of the Padre Paraíso Pegmatite Field.

The use of flexible spiral drains after non-cardiac thoracic surgery. A clinical study.

OBJECTIVE: After an observational study on 50 patients determined the efficacy and safety of a small calibre (19F), flexible, fluted spiral drains with round cross-section after non-cardiac thoracic surgery we undertook a prospective study to compare these drains to standard chest drains also in terms of pain using a Visual Analog Score. METHODS: One hundred consecutive patients who had to undergo non-cardiac chest surgery either by thoracotomy or by VATS were randomly assigned to receive small calibre drains with round cross-section (group A) or the standard chest drains (group B) to drain the pleural space. Drains were connected to a unitized chest drainage system. Pain was assessed using a Visual Analog Scale (VAS) 0-100. RESULTS: The amount of fluid evacuated daily in patients who received the spiral drains was as much as 1150 ml, that of patients who received standard drains was as much as 950 ml. In no case did spiral drains have to be replaced with standard tubes. In group A first drain was removed after a mean of 3.4 days and the second after a mean of 5.9 days; in group B after a mean of 4.1 and 6.1 days, respectively. Patients were discharged after a mean of 8.5 days in group A (SD 4.04) and 8.1 days in group B (SD 4.76). There were no drains-related complications in both groups. The drains-related pain for the patient was significantly less for patients with spiral drains compared to standard drains at rest, during cough induced by respiratory therapists and at the time of removal. CONCLUSIONS: Spiral drains proved to be at least as safe and effective as conventional tubes after lung surgery; they allowed for evacuation of large amounts of blood/fluid as well as air, and were associated with minimal discomfort.

Lung resection for bronchogenic carcinoma after pneumonectomy: a safe and worthwhile procedure.

OBJECTIVES: Patients treated surgically for lung cancer can develop either a metachronous cancer or a recurrence. The appearance of a new cancer on the remaining lung after a pneumonectomy poses unique treatment problems, and surgery is often considered contraindicated. We report on the outcome of resections for lung cancer after pneumonectomy performed for lung cancer. METHODS: We reviewed the records of patients who underwent a resection of bronchogenic carcinoma on the remaining lung from 1990 to 2002. RESULTS: There were 14 patients (13 males and 1 female) with a median age of 64 years (range 51-74). Median preoperative Fev1 was 1.45 (range 1.35-2.23), corresponding to 59% of predicted Fev1 (range 46-80%). Resection was performed between 11 and 264 months after pneumonectomy (median 35.5). The resections performed were: one wedge resection in 11 patients, two wedge resections in two patients and two segmentectomies in two other patients; one patient underwent a third resection. Diagnosis was metachronous cancer in 12 patients and metastasis in two patients. Complications occurred in three patients (21%), while operative mortality was nil. Mean hospital stay was 10.5 days (6-25). Two patients received chemotherapy (one after local recurrence, one after the third resection). Overall 1, 3 and 5 year survivals were 57, 46 and 30%, respectively (median 21 months). For patients with a metachronous cancer they were 69, 55 and 37% (median 57 months), respectively, while neither patient with a metastatic tumor survived 1 year (P=0.03). CONCLUSIONS: Limited lung resection on a single lung is a safe procedure associated with acceptable morbidity and mortality rates. In patients with a metachronous lung cancer, long-term survival with a good quality of life can be obtained with limited resection on the residual lung.

[The follow-up of the heart transplant patient]. / Follow-up del paziente cardiotrapiantato.

The authors' purpose is to describe the follow-up of heart-transplant patients after they are released from the heart transplant center and entrusted to their personal physicians and/or to peripheral hospital centers. Three principle periods have been identified. FIRST THREE MONTHS: This period is characterized by a high risk of morbidity and mortality due to the various hemodynamic, immunologic and infectious problems present after transplantation. These problems require careful clinical and laboratory monitoring for diagnostic identification and correct treatment. Because of the complexity of procedures such as endomyocardial biopsy, infusion therapy and incidental pacemaker installation, the patient must be attended to by the heart transplant center. FROM THE THIRD MONTH TO THE FIRST YEAR: This corresponds to the period in which the subject is definitively released from the hospital to his or her own home. The aggressive immunologic action slows down and the first iatrogenic complications arise. Without neglecting the risk of rejection, it is also very important to monitor infectious complications, especially the ones caused by bacterial and/or mycotic agents even after minor incidents. This is particularly true when the patient resumes his own daily and work activity, which must nevertheless be encouraged and aided. The follow-up can be done by peripheral hospital centers, as long as the patients stay in close contact with the transplant center. AFTER THE FIRST YEAR: A satisfactory balance with the cellular immunologic action is achieved and the graft begins to suffer from the slow action of circulating antibodies, whose principle target is the coronary endothelium. Coronary artery disease begins to progress with multiple myocardial ischemic consequences: this represents the chronic rejection phenomenology. There is a further complication in the follow-up of these patients, i.e. the high incidence of neoplasms, particularly lymphomas and skin tumors supported by the immunosuppressive treatment. Together, coronary artery disease and neoplasms represent the most important factors in late mortality (34%).

Azathioprine-related cholestatic jaundice in heart transplant patients.

Azathioprine is an immunosuppressive drug occasionally indicted as the cause of some episodes of acute cholestasis. The case described confirms the possibility of acute, severe, and reversible cholestatic hepatopathy of iatrogenic (toxic rather than idiosyncratic) origin.