Micro- and nano-hydroxyapatite as active reinforcement for soft biocomposites.

Pectin-based biocomposite hydrogels were produced by internal gelation, using different hydroxyapatite (HA) powders from commercial source or synthesized by the wet chemical method. HA possesses the double functionality of cross-linking agent and inorganic reinforcement. The mineralogical composition, grain size, specific surface area and microstructure of the hydroxyapatite powders are shown to strongly influence the properties of the biocomposites. Specifically, the grain size and specific surface area of the HA powders are strictly correlated to the gelling time and rheological properties of the hydrogels at room temperature. Pectin pH is also significant for the formation of ionic cross-links and therefore for the hydrogels stability at higher temperatures. The obtained results point out that micrometric-size hydroxyapatite can be proposed for applications which require rapid gelling kinetics and improved mechanical properties; conversely the nanometric hydroxyapatite synthesized in the present work seems the best choice to obtain homogeneous hydrogels with more easily controlled gelling kinetics.

A case of primary malignant hemangiopericytoma of the heart with fatal outcome.

Hemangiopericytoma is a rare, highly vascular tumor which has both malignant and benign varieties. We report a case of a 41-year-old man who underwent surgery in emergency because of cardiac tamponade. The histopathologic examination of the specimens revealed primary malignant cardiac hemangiopericytoma. The patient died 46 days from the beginning of symptoms and 13 days after surgery.

Noninvasive pressure support ventilation in non-COPD patients with acute cardiogenic pulmonary edema and severe community-acquired pneumonia: acute effects and outcome.

OBJECTIVE: To compare the acute effects of noninvasive pressure support ventilation (NIPSV) in non-COPD patients with acute cardiogenic pulmonary edema (CPE) and severe community-acquired pneumonia (CAP) presenting with a similar hypoxemic respiratory failure and exploring the ensuing impact on outcome. DESIGN. Prospective, observational study. SETTING. Multidisciplinary ICU, regional teaching hospital. PATIENTS: Non-COPD patients with CPE or severe CAP. MEASUREMENTS AND RESULTS: Fifteen patients with CPE and eighteen with CAP were included. Both groups had similar low PaO2/FiO2 ratios at admission; SAPS II, baseline pH(a) were lower in the CPE group than in the CAP group. Within the first NIPSV observation period (60 min), the oxygenation improved significantly in both CPE and CAP-groups; respiratory rate (RR) significantly decreased in the CPE group ( P=0.005), but it remained unchanged in the whole CAP group; heart rate and mean arterial pressure significantly decreased in both groups. One patient (6.6%) in the CPE group and seven patients (38%) in the CAP group were intubated ( P=0.04). The mean total time spent on NIPSV was 9.6+/-6.3 h in the CPE and 37.2+/-36 h in the CAP group ( P=0.01). Unit mortality rate was 6.6% in the CPE and 28% in the CAP group ( P=0.2). Upon inclusion, all but one CAP patients who were subsequently intubated had a bacteremic pneumonia; unit mortality rate was 57% in intubated- and 9% in non-intubated CAP patients ( P=0.05). CONCLUSIONS: NIPSV equally and rapidly improved oxygenation in non-COPD patients with CPE and severe CAP presenting with a similar hypoxemic respiratory failure, but the subsequent outcome was definitely different in the two groups, depending on the nature of the acute lung injury.

Treatment of erosive reflux oesophagitis: a double-blind multicentre trial with nizatidine 300 mg b.i.d. versus placebo.

Histamine H2-receptor antagonists at conventional doses have proved only partly efficacious in the treatment of reflux oesophagitis. The aim of this study, therefore, was to compare the efficacy of high doses of nizatidine (300 mg b.i.d.) versus placebo in 117 patients with grade I and II oesophagitis. After 6 weeks' treatment, 70.6% of nizatidine-treated patients showed complete endoscopic healing against 25.4% of placebo-treated subjects (p less than 0.001). After 12 weeks, the respective healing rates were 77.5% and 47.4% (p less than 0.01). Nizatidine also proved significantly more effective than placebo in improving overall symptoms (p less than 0.05). Antacid intake was significantly greater in the placebo group (p less than 0.001). Both treatments were well tolerated. In conclusion, this study demonstrates that nizatidine at the dose of 300 mg b.i.d. for 6-12 weeks constitutes an effective treatment for patients with reflux oesophagitis.

Atherosclerosis and aging. A morphometric study on arterial lesions of elderly and very elderly necropsy subjects.

A histomorphometric study was performed on arterial wall lesions of different arterial regions (arch, thoracic, abdominal parts of the aorta; right and left common and internal carotid arteries; coronary arteries; and basilar and middle cerebral arteries), collected from 108 elderly and very elderly (greater than 90 years of age) subjects who underwent necropsy. Lumen stenosis percentage, mean intimal thickening, and mean thickness of the media were measured by means of a computerized system using a manual input and graphic printout; statistical tests were performed using variance and regression analysis. Results showed that the arterial wall lesions in patients over 60 years of age tend to be stabilized in all regions studied except for the cerebral region, where the lesions tend to have a continuous progression related to age, even in a group of subjects over 90 years of age.