Occupational silica exposure and lung cancer risk: a review of epidemiological studies 1996-2005.

BACKGROUND: In 1997, a Monograph from the International Agency for Research on Cancer (IARC) classified occupational exposure to crystalline silica as carcinogenic to humans. Large amounts of epidemiological data have been published subsequently. METHODS: We conducted a systematic review of epidemiological investigations on silica exposure and lung cancer risk published after the IARC Monograph, including 28 cohort, 15 case-control and two proportionate mortality ratio (PMR) studies. These were identified in the available literature. RESULTS: The pooled RR of lung cancer, calculated using random effects models, from all cohort studies considering occupational exposure to silica was 1.34. The RRs were 1.69 in cohort studies of silicotics only, 1.25 in studies where silicosis status was undefined and 1.19 among non silicotic subjects. The pooled RR was 1.41 for all case-control studies. The RRs were 3.27 in case-control studies of silicotics only, 1.41 in studies where silicosis status was undefined and 0.97 among non silicotic subjects. The RR was 1.24 for PMR studies. CONCLUSIONS: In this re-analysis, the association with lung cancer was consistent for silicotics, but the data were limited for non silicotic subjects and not easily explained for undefined silicosis status workers. This leaves open the issue of dose-risk relation and pathogenic mechanisms and supports the conclusion that the carcinogenic role of silica per se in absence of silicosis is still unclear.     

An alternative approach in the surgical treatment of infectious endocarditis. The fresh antibiotic-sterilized aortic valve homograft

Following the pioneering work of Ross and Barratt-Boyes, there is currently a strong evidence based on long-term follow-up data that valve homografts are the best valve substitutes in the aortic position. Currently there exists a renewed interest in the use of fresh and cryopreserved homografts as we know that homografts show a prolonged durability together with the lack of thromboembolic complications. Here we present the case histories of 3 patients undergoing aortic valve replacement by fresh homografts sterilized in antibiotic solution. The underlying pathology was infective endocarditis in all 3 patients, a disease that is considered the ideal indication for homograft implantation. Technical details at the time of implantation, their advantages with regard to other replacements devices and the whole process of procurement, manipulation and preservation are commented on.     

Aortic valve replacement by a pulmonary homograft

Minor experience still exists in our country with regard to the use of valve homografts in cardiac surgery. Only a few implantations have been performed in cases of right ventricular outflow tract reconstruction in addition to our own experience in cases of infective endocarditis of the aortic valve. We present a case of aortic valve replacement by using an antibiotic-sterilized fresh pulmonary valve autograft. The case is described and the possible advantages of the use of pulmonary allografts in the aortic position are discussed.     

Genetic ablation of the t-SNARE SNAP-25 distinguishes mechanisms of neuroexocytosis.

Axon outgrowth during development and neurotransmitter release depends on exocytotic mechanisms, although what protein machinery is common to or differentiates these processes remains unclear. Here we show that the neural t-SNARE (target-membrane-associated-soluble N-ethylmaleimide fusion protein attachment protein (SNAP) receptor) SNAP-25 is not required for nerve growth or stimulus-independent neurotransmitter release, but is essential for evoked synaptic transmission at neuromuscular junctions and central synapses. These results demonstrate that the development of neurotransmission requires the recruitment of a specialized SNARE core complex to meet the demands of regulated exocytosis.     

Synchronous associations of tumors in the pelvic organs of the female genital tract]

The Authors report their findings concerning the synchronous associations of tumours involving pelvic organs in the female genital tract observed at the Gynecological Clinic, Aquila. From January 1980 to December 1991, 9 cases (4.28%) of synchronous tumours were found in a total of 210 cases of womb, ovary and vagina tumours. The paper examines the clinical problems and questions of anatomopathological characterisation raised by these associations.     

Substance abuse and psychopathology

This report evaluates, using DSM III, the psychopathological profile of 226 heroin users taken in at the clinical centre of "Cascina Verde" Therapeutic Community (Milan, Italy) and admitted to a psychotherapeutic, retraining, integrated, both out-and-in-patient treatment. The outcome shows that 30% of subjects are to be diagnosed according to Axis I while 61% are to be considered among Axis II personality disorders. A portion of 16% is to be referred to the "schizophrenic spectrum", 25% has histrionic, narcissistic, antisocial and borderline personality disorders and the remaining are to be referred to an extremely heterogeneous category. The report shows also data concerning Axes IV and V, always according DSM III.     

Aerobic exercise performance correlates with post-ischemic flow-mediated dilation of the brachial artery in young healthy men

In older healthy men, aerobic exercise capacity is related to postischemic flow-mediated dilation of the brachial artery (FMD), but corresponding data in a younger population is not available. In addition, whether submaximal aerobic exercise performance also correlates with this kind of vasomotor reactivity is not known. Therefore, in 15 nonsmoking young healthy men [age 27 (5) years; body mass index: 24 (2) kg/m²; mean (SD)] with different levels of ordinary physical activity, but not performing upper-extremity training, we measured FMD at 1 min after reactive hyperemia, and pulmonary oxygen uptake (O₂) at ventilatory anaerobic threshold (O₂AT) and at peak effort (peak O₂) during an incremental exercise on a treadmill. In our participants, FMD was 9.1 (3.4)%, O₂AT was 40.72 (5.92) ml/kg per min, and peak O₂ was 52.95 (8.13) ml/kg per min. Using bivariate Pearsons correlation, and in separate multivariate regression analyses, O₂AT and peak VO₂ showed a significant and reasonably good correlation with FMD (r=0.84, P<0.001 and r=0.77, P=0.001, respectively), independent of age, body mass index and serum total cholesterol (=0.77, P<0.001, R² of the overall model=0.79 and =0.70, P<0.005, R² of the overall model=0.69, respectively). Our data provide evidence suggesting that in young healthy men a higher submaximal and maximal aerobic exercise performance is associated with a greater FMD of peripheral conduit arteries.     

Presence of Rickettsia conorii subsp. israelensis, the causative agent of Israeli spotted fever, in Sicily, Italy, ascertained in a retrospective study

A retrospective analysis by molecular-sequence-based techniques was performed to correctly identify the etiological agent of 24 Mediterranean spotted fever cases occurring in Western Sicily, Italy, from 1987 to 2001. Restriction analysis of a 632-bp PCR-amplified portion of the ompA gene allowed presumptive identification of five clinical isolates as belonging to Rickettsia conorii subsp. israelensis, the etiological agent of Israeli spotted fever (ISF). The remaining 19 rickettsial isolates were Rickettsia conorii subsp. conorii, the only pathogenic rickettsia of the spotted fever group reported in Italy until the present. Sequence analysis of the ompA gene confirmed the identification of all the R. conorii subsp. israelensis isolates and demonstrated that rickettsiosis caused by R. conorii subsp. israelensis can be traced back to 1991 in Sicily. The recorded clinical data of the five ISF patients support the idea that these strains could correlate to more-severe forms of human disease. Three of five patients experienced severe disease, and one of them died.     

Mapping antigenic sites of an immunodominant surface lipoprotein of Mycoplasma agalactiae, AvgC, with the use of synthetic peptides

As a first step toward the design of an epitope vaccine to prevent contagious agalactia, the strongly immunogenic 55-kDa protein of Mycoplasma agalactiae was studied and found to correspond to the AvgC protein encoded by the avgC gene. The avg genes of M. agalactiae, which encode four variable surface lipoproteins, display a significant homology to the vsp (variable membrane surface lipoproteins) genes of the bovine pathogen Mycoplasma bovis at their promoter region as well as their N-terminus-encoding regions. Some members of the Vsp family are known to be involved in cytoadhesion to host cells. In order to localize immunogenic peptides in the AvgC antigen, the protein sequence was submitted to epitope prediction analysis, and five sets of overlapping peptides, corresponding to five selected regions, were synthesized by Spot synthesis. Reactive peptides were selected by immunobinding assay with sera from infected sheep. The three most immunogenic epitopes were shown to be surface exposed by immunoprecipitation assays, and one of these was specifically recognized by all tested sera. Our study indicates that selected epitopes of the AvgC lipoprotein may be used to develop a peptide-based vaccine which is effective against M. agalactiae infection.