[Work at high altitudes: risk factors and health surveillance]. / Il lavoro in alta quota: fattori di rischio e sorveglianza sanitaria.

Work at high altitude (elevation equal to or greater than 3000 m above sea level) results in a physiological adaptation of the human organism to changing environmental conditions. The main problem related to the altitude is represented by the reduction of partial pressure of oxygen (hypoxia). Our study takes into consideration occupational risk factors: those related to physical environment of high altitude; those related to the worker; those related to the characteristics of the job. It is finally addressed the decision making process related to the formulation of the judgment of suitability for performance of work activities at high altitude. The health protocol proposed requires an accurate anamnestic investigation aimed at gathering information on pre-existing pathophysiological conditions that need, once identified, clinical and instrumental tests specific and targeted. These clinical protocols are analyzed and proposed for the main pathophysiologic conditions that pose a risk to health at high altitude.

Pituitary cotransplantation significantly improves the performance, insulin content, and vascularization of renal subcapsular islet grafts.

Because the pituitary contains hormones with beta-cell trophic activity, we evaluated whether cotransplantation of pituitary tissue with pancreatic islets might be beneficial for islet graft function and survival. Streptozotocin diabetic nude mice were transplanted under the kidney capsule with 150 handpicked islets alone or mixed with two diced pituitaries and were then followed for 4 weeks. Mice transplanted with mixed islet/pituitary grafts had higher levels of circulating prolactin (PRL) than mice transplanted with islets only, while serum cortisol, growth hormone, and follicle-stimulating hormone were similar in the two groups. After transplantation, recipients of mixed islet/pituitary grafts showed a more pronounced decrease in glycemic levels and higher systemic insulin levels than mice transplanted only with islets. Mixed islet/pituitary grafts were macroscopically characterized by an excellent vascularization and were biochemically characterized by higher insulin and PRL content than pure islet grafts. Histologically, posttransplantation remodeling originated a hybrid organ in which healthy, well-vascularized islets were adjacent to pituitary cell clusters. Transplantations performed to address the specific effect of the anterior versus the intermediate pituitary lobes indicated the former as responsible for the improved function of cotransplanted islets. Mixed islet/pituitary grafts composed of anterior lobes were also the best vascularized and were histologically characterized by the presence of many folliculo-stellate cells. In conclusion, we obtained evidence that pituitary cotransplantation significantly improves the function, insulin content, and vascularization of suboptimal islet grafts. Evidence suggesting that ectopically produced PRL and/or locally released angiogenic peptides might play a causal role is provided.

[Deep hypothermia for the correction of a congenital cardiac defect complete with atrioventricular block]. / Ipotermia profonda di superficie per la correzione di una cardiopatia complessa con BAV completo congenito.

The techniques of deep hypothermia for correction of congenital cardiac defects are well known in many cardiac centers and many cases can be treated even if there are pre-existing rhythm troubles. Our patient had the following diagnosis: left atrial isomerism, dextrocardia; left sided azygos continuation of inferior vena cava; left and right superior venae cavae, hepatic veins, pulmonary veins, all draining into a common atrium; d-loop with normally related ventricles; ventriculo-arterial concordance, small VSD. In addition complete a-v block was present. The patient, 40 days old and 3.4 kg., in heart failure, was paced with a temporary transvenous catheter at 130/min and, afterwards, catheterized. Surgery was undertaken three days post-catheterization using surface deep hypothermia. A Mustard operation, including enlargement of the new left atrium with PTFE (Goretex), was performed during total circulatory arrest. At the end, a permanent pacemaker was positioned in the abdomen and epicardial wires were left on the right ventricle. The postoperative period was uneventful and the patient is doing well 3 months latter. The interest of the case is that even in a complex congenital cardiac malformation with complete a-v block, the technique of surface deep hypothermia can be used because all the physiological parameters remain stable during the procedure in spite of the very low heart rate.