[Prevention of thromboembolism in patients operated on for hip prosthesis]. / La prevenzione delle tromboembolie negli operati di artroprotesi d'anca.

The latest research into the prevention of peri- and postoperative thromboembolic disease has found orthopaedic surgery patients to be most at risk. As the genesis of deep venous thrombosis (DVT) is due to haemodynamic, hemorheologic and parietal factors, various prophylactic measures have been considered in the past, measures which have not proved able to provide satisfactory protection in orthopaedics. The results obtained with Defibrotide in a random and controlled clinical study versus calcium heparin involving 211 patients of both sexes candidates to receive total hip arthroplasty and presenting at least one major thromboembolic risk factor are reported. The patients were assigned at random to one of the following treatments: 1) Defibrotide at a dose of 400 mg b.i.d. i.v. in 50 ml phleboclysis in 5 minutes (n = 108); 2) calcium heparin at a dose of 5000 IU t.i.d. subcutaneously (n = 103). The treatment began the day before operation and continued on average up to the eighth day for the Defibrotide group. With the control group it continued until discharge (usually on the 15th day) and at home for about three weeks until the completion of the physiotherapy cycle. In the 108 patients treated with Defibrotide only one case of DVT was reported and in none of these patients were symptoms or signs of pulmonary embolism encountered. In the group treated with calcium heparin 2 cases of clinically and radiologically diagnosed pulmonary embolism and 4 cases of DVT were observed. Although the differences were not statistically significant, the tendency favours Defibrotide. Statistically significant (p less than 0.01) was the difference in postoperative bleeding evaluated with particular attention in patients of advanced age. Further, in the Defibrotide group, scarring was considered excellent in 96% of cases while in the heparin group scarring was excellent in 85% (p less than 0.05). To conclude, the sure clinical effectiveness, tolerance, handiness and lack of interference with clotting functions make Defibrotide a really useful drug for the prevention of thromboembolic episodes in patients undergoing major orthopaedic surgery.

Irradiance measurements of some UV sources.

The use of UV radiation sources in the scientific, medical and industrial fields is becoming increasingly widespread. This poses the problem of protection and calls for a set of rules fixing the maximum exposure values for the organs subjected to the radiation hazard. The purpose of this work is to analyze some commonly used sources by first determining the spectral composition of the radiation emitted in the 200-400 nm range, and the total effective irradiance from which the maximum exposure time is inferred. The latter is measured on the basis of the criteria fixed by ACGIH. The final interests is that of providing some evaluation of the hazards connected with the use of some widely used sources.

[Tibial osteotomy in the treatment of static gonarthrosis]. / L'osteotomia tibiale nel trattamento delle gonartrosi statiche.

Results of 35 cases of subcondylar tibial osteotomy performed for static osteo-arthritis of the knee from 1072-75 are reported. The surgical procedure consists of an oblique osteotomy followed by the removal of a wedge of bone with an internal or external base depending on the presence of "genu valgum" or "genu varum" respectively. Bone ends are united by screws. Major advantages of this operation are solid bony union of the osteotomy sections by screws and simplicity of execution.

Cesium chloride density gradient study of some modifications induced by ultraviolet radiation on the denatured DNA molecule of phage T2.

The behaviour of the modifications due to ultraviolet (UV) radiation on denatured phagic DNA has been investigated by looking at the changes of density in CsCl gradient, after irradiation with increasing doses of monochromatic light. The spectral range studied is 2300-2900 A, with a wavelength resolution Deltalambda = +/-20 A. The observed effect is a gradual shift toward higher densities as the UV absorbed dose increases. The experimental results show an exponential law and the analysis of the action spectra indicates that thymine is the main factor responsible for the observed effect. An evaluation of the quantum yield for the thymine-dimers formation gives a constant value of (18 +/- 3) x 10(-3) quanta(-1).

The wavelength dependence of some effects of ultraviolet radiation on in vitro DNA of phage alpha.

The wavelength dependence of some of the effects of ultraviolet radiation on the physicochemical properties of DNA of phage alpha irradiated in vitro are discussed. An analytical ultracentrifuge and a spectrophotometer were used to study (a) the breaking of individual polynucleotide strands; (b) the local denaturation; (c) the presence of a fraction of molecules resistant to denaturation; and (d) the increase in the buoyant density of irradiated DNA. All the curves show a slight variation of the radiation efficiency in the range 2600-2800 A, and a well defined peak at lambda = 2880 A.