Search

The aim of this study was to propose a protocol for assessment of markers of infection with hepatitis B virus (HBV) and hepatitis C virus (HCV) in exposed health care professionals and to define criteria for evaluation of fitness for the job of the infected personnel. The study comprised 800 persons involved in operative procedures, including 414 surgeons, 275 nurses, and 111 anaesthetists. A graduated protocol was created for monitoring markers of HBV and HCV infection. A well-defined combination of markers of antigen-antibody systems enabled identification of four groups of persons with HBV infection differing in fitness for work: 1) HBsAg-positive, HBeAg-positive, HBV DNA-positive; 2) HBsAg-positive, anti-HBe-positive, HBV DNA-positive; 3) HBsAg-positive, anti-HBe-positive, HBV DNA-negative; and 4) anti-HBs-positive, anti-HBc-positive, anti-HBe-positive group. For HCV infection, two groups with different job fitness were identified: 1) anti-HCV-positive, HCV RNA-negative and 2) anti-HCV-positive, HCV RNA-positive. Screening of hospital personnel at risk to HBV and HCV infection requires a well-defined protocol which may help to evaluate the fitness of the infected personnel for a specific job.

This study would examine the efficiency of different diagnostic tools, imaging and functional, in the study of pulmonary system of workers exposed to silicotigen dusts. 24 male miners were examined with chest H.R.T.C., spirometry with study of DLCO and of total lung capacity. 13 of 24 miners were submitted to pulmonary ventilatory scintigraphy (99mTcDTPA). All 24 miners were previously yet submitted to two follow-up by means of chest radiography in conformity with ILO guidelines. The chest radiography, even evaluated in conformity with ILO guidelines, is subject to remarkable differences when performed and reported by different operator. Useful data are provided by functional studies. H.R.T.C. is necessary to evaluate the degree of parenchymal involvement and for medicolegal porpoises. Scintigraphy with 99mTc DTPA need of further studies in the evaluation of exposure to silicotigen dusts.

Some activities performed by healthcare workers may still involve total or partial exposure to ionising radiation exceeding the limit values. In addition to the appearance of crystalline lens opacities which may lead to rays-cataract, recent studies have indicated possible induction of ocular hypertonia in occupationally exposed subjects. The aim of this study was to establish the actual prevalence of ocular hypertonia and crystalline lens opacities in a group of healthcare workers exposed to ionising radiation. The collected data failed to show significant risk of ocular hypertonia and suggested that crystalline lens opacity was not an important indicator of exposure. Notwithstanding, preventive and periodic (every 5 years) ophthalmologic control may prove helpful for medicolegal purposes. Namely, such control would record congenital crystalline lens opacities in many individuals and would thus rule out unjustified claims of occupational disease due to exposure to ionising radiation. Additionally, ophthalmologic control should focus on different and probably more important ocular risks for the radiologists such as the ocular fatigue resulting from a prolonged use of a video display terminal or other diagnostic screens or electrodiaphanoscopes.

Urban soil may be a source of occupational exposure to various pollutants in gardening and land cultivation. This paper presents data of a one-year follow-up of lead, cadmium, nickel, chromium, and vanadium in the environment of the city of Bologna. Samples of soil and leaves were collected at three locations; gardens from the inner-city high-traffic area, parks in moderate-traffic area, and parks in suburban, low-traffic area. The top and deeper layers of soil and leaves were mainly polluted by lead at all locations, which corresponded to the traffic density. Personal samplers recorded greater concentrations of airborne metals than did the area samplers but the values kept below the threshold limit established by the American Conference of Governmental Industrial Hygienists for the working environment. Due to cumulative nature and interactive effects of toxic metals with other toxic and essential elements, long-term exposure to metals in the urban environment may be a health risk for occupationally exposed gardeners.

A 27-year-old woman presented with multiple nodules closely grouped on her right upper distal extremity. The lesions, dating from childhood, increased slowly in time. Microscopic examination of one nodule showed the histologic features of spindle cell hemangioendothelioma (SCH). At the periphery of the nodule there were also some features of the so-called sinusoidal hemangioma. Clinically, SCH can present as a solitary lesion or as multiple lesions in zonal distribution. When the lesions are multiple, the diagnosis of Maffucci's syndrome should be considered. SCH may be interpreted as a reactive process secondary to thrombosis and recanalization occurring in angiomatous lesions with different clinical presentations. Spindle cells are probably mesenchymal cells modified by blood pressure. For this entity the term hemangioma seems to be preferable to that of hemangioendothelioma.

Introduction: Percutaneous treatment of chronic iliac artery occlusion has not yet gained complete acceptance as the method of choice. The reason of this widespread skepticism are the poor results achieved with angioplasty and/or lysis therapy. The introduction of stents seems to open new perspectives to percutaneous treatment and the latest follow-up studies report encouraging results., Material and Methods: We report our personal experience in percutaneous mechanical revascularization of chronic iliac occlusion with primary stent placement in 29 patients with 2 years' maximum follow-up. Clinically the patients had at least 3 months' claudication and were in Fontaine stages II to IV. The occlusion was passed mechanically using a hydrophilic guide wire, through the contralateral access in 19 cases and ipsilaterally in 10. The stents were primarily implanted in the last 12 patients; in the first 15 patients, after dilatation with undersized balloons, 25 Wallstent and 12 Palmaz stents were implanted. Each patient underwent color Doppler follow-up for 3-24 months. Nine patients underwent angiography too, after one year., Results: The mechanical passage of the guide-wire through the occluded segment was successful in 27 of 29 (93.1%) patients referred for percutaneous revascularization of a chronic occlusion of the iliac artery. The stent was placed and immediate patency was achieved in 100% of these 27 patients. Clinical improvement was of two stages in 24 patients and of one stage in 3 patients. The follow-up showed neither reocclusions nor critical stenoses of the restored iliac segment. Five embolic complications (5%) occurred after angioplasty, all of them treated percutaneously; surgery was never necessary., Discussion and Conclusions: The follow-up studies published in the literature in the last few years and our personal experience encourage the percutaneous treatment of chronic iliac artery occlusions. Percutaneous mechanical revascularization with primary stent positioning can be proposed because it is a reliable and efficacious tool, particularly in young patients in whom a surgical aortoiliac or aortofemoral bypass might injure the pudendal plexis and cause sexual disturbances.

The work associated with repetitive efforts and inadequate resting periods, strong physical exertion, awkward postures or static positioning exposes workers to the risk of cumulative trauma disorders of the upper limbs. These risk factors are present in many agricultural activities. A study was carried out among workers on an agricultural farm. The workers' histories were taken and they were given periodical medical check-ups. The presence of upper limb disorders was shown in a group of workers. A sample of 42 people was selected for the study by means of specific tests: electromyography, ultrasonography and laser-doppler flowmetry. The tests showed a high incidence of carpal tunnel syndrome and microcirculation disorders. The study confirmed that electromyography, ultrasonography and/or laser-doppler flowmetry are highly useful tools for identifying cumulative trauma disorders.

A calorimetric study is reported concerning the interaction between concanavalin A (Con A) and some oligosaccharides and glycopeptides hydrolyzed from hen ovalbumin. The measurements were carried out in acetate buffer, pH 4.5, where, by far, the prevailing form of the protein is the dimeric one [Kalb, A.J., & Lustig, A. (1968) Biochim. Biophys. Acta 168, 366; Dani, M., Manca, F., & Rialdi, G. (1981) Biochim. Biophys. Acta 667, 108]. The calorimetric technique allows the direct determination of the binding enthalpy delta H, degrees B, the evaluation of the apparent association constant K'B, and then the evaluation of the apparent free energy and entropy, delta G degrees' B and delta S degrees' B. Three groups of data have been collected in the present study. The first one concerns the interaction between concanavalin A and some mono- and disaccharides [methyl alpha-glucopyranoside (alpha MGlup), methyl alpha-mannopyranoside (alpha MManp), D-maltose, D-trehalose, and D-cellobiose]. The analysis of the data indicates that in these cases there are small favorable entropic and enthalpic contributions to the affinity. The stoichiometry of the reaction is 2 mol of ligand/mol of Con A dimer, the sites resulting being equivalent and noninteracting. Melezitose, the only trisaccharide studied, shows a different behavior: its affinity for Con A is higher as compared to the other oligosaccharides containing alpha-glucosyl residues and closer to that of methyl alpha-mannopyranoside. However, the stoichiometry is different, namely, 1 mol of ligand/dimer of Con A.(ABSTRACT TRUNCATED AT 250 WORDS)

This study was designed to determine whether styrene absorption through the skin results in measurable changes in biologic indicators of styrene exposure using a group of workers engaged in hand lay-up operations during which extensive styrene skin contact occurs. Serial measurements of expired breath and blood styrene and urinary excretion of mandelic and phenylglyoxylic acid were made in eight female workers during 4 consecutive days using different experimental conditions including either (1) gloves/protective clothing alone, (2) respirator alone, (3) both gloves/protective clothing and respirator, or (4) neither respirator nor gloves/protective clothing. A two-by-two factorial design imbedded in a Latin square design allowed estimation of the effects of the two types of protection (i.e., gloves/clothing and respiratory) and any interaction. Levels of styrene in venous blood and expired breath and urine mandelic and phenylglyoxylic acid excretion were no different when gloves/clothes were used as protection compared to no protection at all. Significant reduction in all biologic indices occurred when respiratory protection was used. The results of the study suggest that percutaneous absorption of styrene is not a significant exposure source and does not significantly contribute to the body burden of styrene of workers in the reinforced plastic industry engaged in hand lay-up operations. Respiratory protective devices were the most effective means for reducing styrene absorption. Even though skin absorption of styrene is limited, skin protection is necessary because of the risk of dermatitis.

A calorimetric study at 25 degrees C is reported on the interaction between allosteric bovine seminal ribonuclease and cytidine-3'-phosphate. The results are compared with those obtained under identical experimental conditions for the interaction of pancreatic ribonuclease A and the same nucleotide. The analysis of the data provides evidence that the binding sites of seminal ribonuclease for cytidine-3'-phosphate are not equivalent, in agreement with previous equilibrium dialysis studies. A model with two sites with different affinities toward the nucleotide, the site with higher affinity resembling the binding site of pancreatic ribonuclease, is proposed. The values calculated for the thermodynamic parameters provide an insight of the forces involved in the interaction of the two enzymes with the nucleotide.

The interaction between Concanavalin A (ConA) and the lanthanide ions La3+ and Gd3+ has been studied calorimetrically at 25 degrees C. The measurements were carried out at a pH of 4.5, where the protein exists prevailingly as a dimer. Calorimetry allows the direct determination of the binding enthalpy and the evaluation of both the apparent association constant, and the apparent free energy and entropy. Three groups of data were collected. The first concerns the interaction of the 'native' protein, i.e., fully metallized with Mn2+ and Ca2+, with the lanthanides. The second concerns the interaction of the completely demetallized protein with La3+ and Gd3+. Finally, the affinity of each complex was tested for the specific sugar alpha-methylmannopyranoside. The analysis of the thermodynamic parameters obtained, led to the following conclusions: 1) a specific site, named S3, exists on the protein for the lanthanides, distinct from the S1 site of the transition metal and from the S2 site, specific for calcium. There is only one S3 site per protomer when the protein has Mn2+ in S1 and Ca2+ in S2. Moreover, there is no appreciable competition for S1 and S2 from the lanthanides. The 'native' protein, metallized with La3+ or Gd3+, is a fully functional protein. 2) The demetallized protein (ApoCon A) has at least two sites per protomer for the lanthanides. The hypothesis is that, besides the S3 site, the lanthanides, in the absence of Mn2+, can also occupy the S1, but not the S2, site. The protein metallized only with gadolinium ion is completely inactive toward the interaction with the mannoside. The same happens when, along with gadolinium, only calcium or manganese is present. Hence, in the absence of the transition metal in S1 or of calcium in S2, the protein is not in the conformation suitable to interact with its specific substrate.

We have studied the binding of spermatozoa to the receptor sites on the vitelline coat (VC) of glycerol-treated eggs (ghost eggs) of the Ascidian, Ciona intestinalis (Protochordate). Glycerol treatment cytolyses the egg without affecting the ability of the VC to bind spermatozoa in a species-specific manner; however, in this system binding is not followed by the acrosome reaction. The ghost eggs are metabolically inert. As a base line for our analysis, we have studied the concentration-dependent heat evolved and oxygen consumption of spermatozoa when diluted in sea water. The process has been analyzed on the basis of equations derived by Liquori and Tripiciano to describe cell growth. Upon binding to the ghost eggs, the spermatozoa produce an explosive heat evolution (excess heat) which is not accompanied by oxygen consumption. The excess heat produced plotted against sperm concentration (at constant egg concentrations) gives an asymmetric bell-shaped curve. This is interpreted as being due to the competitive effect of sperm agglutination at a high sperm concentration. It is concluded that only spermatozoa that attach singly (monomeric spermatozoa) to the egg undergo metabolic activation.