Toxicological properties of nanoparticles of organic compounds (NOC) from flames and vehicle exhausts.

We examined the biological reactivity in vitro of nanoparticles of organic compounds (NOC) with diameters, d = 1-3 nm, a class of combustion-generated particulate relatively unstudied compared to larger more graphitic soot particles because of their small size even though they may contribute significantly to the organic fraction of PM sampled from vehicle exhausts and urban atmospheres. We tested NOC samples collected from 2004 model vehicle emissions and laboratory flames. NOC produced a dose dependent mutagenic response in Salmonella bacteria, suggesting that NOC may add significantly to the overall mutagenicity of vehicle emissions. Incubation with peptides caused agglomeration and precipitate of the otherwise stable NOC suspension, but the chemical and/or physical nature of the NOC-peptide interactions could not be resolved. A significant cytotoxic response was measured above a critical dose of NOC in mouse embryo fibroblasts NIH3T3 cells along with possible evidence of cellular uptake by optical and confocal microscopy. The toxicological assays showed that NOC collected from flames and vehicle exhausts effectively interacted in vitro with both prokaryotic and eukaryotic cells. Differences in mutagenic potencies observed for various Salmonella strains with and without metabolic activation indicate differences in the chemical composition of NOC collected from different vehicles and flames.

Detection of combustion formed nanoparticles.

UV-visible extinction and scattering and two extra situ sampling techniques: atomic force microscopy (AFM) and differential mobility analysis (DMA) are used to follow the evolution of the particles formed in flames. These particle sizing techniques were chosen because of their sensitivity to detect inception particles, which have diameters, d<5 nm, too small to be observed with typical particle measurement instrumentation. The size of the particles determined by AFM and DMA compares well with the size determined by in situ optical measurements, indicating that the interpretation of the UV-visible optical signal is quite good, and strongly showing the presence of d=2-4 nm particles. UV-visible extinction measurements are also used to determine the concentration of d=2-4 nm particles at the exhausts of practical combustion systems. A numerical model, able to reproduce the experimentally observed low coagulation rate of nanoparticles with respect to soot particles, is used to investigate the operating conditions in the combustion chamber and exhaust system for which 2-4 nm particles survive the exhaust or grow to larger sizes. Combustion generated nanoparticles are suspected to affect human and environmental health because of their affinity for water, small size, low rate of coagulation, and large surface area/weight ratio. The ability to isolate nanoparticles from soot particles in hydrosols collected from combustion may be useful for future analysis by a variety of techniques and toxicological assays.

A modeling evaluation of the effect of chlorine on the formation of particulate matter in combustion.

The effect of chlorine on the fuel-rich oxidation of hydrocarbons and on the molecular weight growth of aromatics is analyzed by simulating experiments featuring a model chlorinated additive CH3Cl in a jet-stirred/plug-flow reactor and premixed flames. The kinetic model used in this work emphasizes the role of resonantly stabilized radicals in the formation and growth of aromatics, and considers soot inception as the net effect of molecular weight growth and graphitization of aromatic structures. Chlorinated hydrocarbons decompose at temperatures significantly lower than hydrocarbons, producing reactive Cl-atoms, which have a strong tendency to go to HCl. The HCI, tying up the H-atoms, inhibits hydrocarbon oxidation. The model is able to predict not only the levels but the shape of the experiments quite well and also the surprising finding of an increased soot formation associated with lower PAH levels found in rich flames with significant levels of chlorine. Based on reaction kinetic analysis, chlorine addition to the fuel enhances soot formation by promoting the formation of aromatic-ring compounds and accelerating the abstraction of aromatic H-atoms from stable PAH molecules. This process activates the transformation of aromatics to soot.

[Gn-RH analogs in the treatment of benign gynecologic diseases: current trends]. / Gli analoghi del Gn-RH nel trattamento della patologia ginecologica benigna: orientamenti attuali.

Gn-RH analogues have been recently employed for the treatment of oestrogen-dependent benign gynaecological disorders, such as uterine myomata, endometriosis or metrorrhagia. They induce a "pharmacological castration", inducing a marked reduction of serum oestrogen levels. They proved more effective than other drugs used up to now in the medical treatment of these benign gynaecological diseases. Thus they were initially employed in every case. Later it became clear that Gn-RH analogues need a selective indication. The authors herein report their series of 70 patients with benign gynaecological disorders (45 uterine fibroids, 10 endometriosis, 15 metrorrhagia), treated with a Gn-RH analogue depot for 2-3 months preoperatively. They evaluated the efficacy of the treatment in the group with uterine fibroids in terms of disappearance of metrorrhagia, better haemoglobin level in anaemic patients, reduction of fibroids size allowing for a simpler and less extensive surgery (vaginal surgery, myomectomy, hysteroscopic resection). The authors discuss those cases when preoperative treatment with Gn-RH analogues is not indicated, or should be employed only under careful surveillance (in the preparation of multiple myomectomies, big submucosal myomas). In the group of 10 patients with endometriosis we observed the disappearance of pelvic pain and dyspareunia, whereas the size of endometriomas was only minimally reduced. The authors discuss the usefulness of this treatment in case of patients with endometriosis grade I or II (minimal or mild), with desire of children. In the group of 15 perimenopausal patients with metrorrhagia, 10 became amenorrhoic after termination of treatment, thus avoiding surgery. The major benefit for the other 5 patients was a better haemoglobin level at the time of surgery.

Genital herpes: therapeutic implications.

Genital infection with HSV is the most common sexually transmitted disease. Once acquired the virus (type 2) is quiescent in sensory nerve ganglia, establishing a latent infection. Seventy to eighty% of the patients infected suffer recurrences. In many cases the recurrent episodes conditioned the rest of life, causing significant morbidity physic and psychosocial. At present only acyclovir seems the effective antiviral chemotherapeutic agent for genital herpes. The experience from studies looking at long term use of the drug as suppressive therapy shows to offer good prospects for management of genital herpes and for control and prevention of his recurrences.

[The indications and need for diuretics in pregnancy]. / Indicazione e necessità dei diuretici in gravidanza.

The authors take into consideration specific cases of pregnancy with remarkable oedema caused by cardiac insufficiency, gestosis, pre-eclampsia and eclampsia. They emphasize that in these conditions and in other similar ones use of diuretics cannot be precluded. They report the case of a pregnant woman with severe cardiac insufficiency and considerable oedema observed at the Obstetric Clinical of Rome University. Thanks to diuretic therapy, the pregnancy could be followed through to full term.

[Genital condylomatosis in women]. / In tema di condilomatosi genitale femminile.

Twenty-six women with genital condylomatosis are treated with electrocoagulation and local interferon cream. The results show that there is a good answer.

[Operations for limb salvage in vascular surgery]. / Gli interventi di salvataggio degli arti in chirurgia vascolare.

Direct revascularization which involve the femoro-popliteo-tibial district is called "limbs salvage" surgery. Such operations are performed in the arteriopathic patient in order to avoid ulcers and distal necrosis, whose natural evolution, without an adequate treatment, leads to amputation. One of the distal by-pass techniques is obtained by using in situ saphenous vein. The Authors report their experience with 281 patients who underwent direct revascularization surgery (by-pass), discussing technique and results.