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Biomedical subjects

M Bovenzi

Publications and source records attributed to M Bovenzi.

At least 73 records · Page 4Linked to original sources
PubMed1987

Finger thermometry in the assessment of subjects with vibration-induced white finger.

The measurement of finger skin temperature (FST) is one of the most commonly used methods for evaluating the response of the digital vessels to cold stimulation. In well-controlled experiments a significant correlation has been observed between FST and digital blood flow over a wide range of water temperatures. On the contrary, FST in air is considered an inadequate index of digital skin circulation since, at a given ambient temperature, FST depends not only on the rate of blood flow through the digit but also on environmental conditions. Despite these limitations, FST recording after a cooling procedure has been used in surveys of vibration-induced white finger (VWF), and a delayed finger rewarming time has been proposed as an indicator of digital vasospasm in workers with VWF. Finger skin thermometry can differentiate between VWF groups and healthy groups, but it is unsuitable for diagnosing Raynaud's phenomenon on an individual basis. The thermometric method has good specificity but its sensitivity is lower than that of plethysmographic techniques. FST after cold provocation may be considered a useful screening test in field studies, while more sensitive methods should be employed to confirm VWF symptoms in individuals objectively, especially for insurance compensation purposes.

Fingers↗
PubMed1986

Some pathophysiological aspects of vibration-induced white finger.

The level of sympathetic nervous activity was assessed by evaluating cardiovascular responses to a cold test in 63 vibration-exposed workers (50 subjects without vibration white finger (VWF) and 13 subjects at stages 1 and 2 of VWF) and in 41 controls. Blood pressure, heart rate, systolic time intervals and the skin temperature of the third finger of the right hand were monitored throughout the cold test period. Basal urinary excretion of free catecholamines and platelet aggregation indices both in vitro and in vivo were also determined in all subjects. Systolic time intervals such as electromechanical systole index (QS2I) and left ventricular ejection time index (LVETI) were found to be shorter in the vibration-exposed workers with and without VWF than in the controls, both at rest and during cold exposure and recovery (p less than 0.001). A significant inverse relationship between urinary free catecholamines and the duration of LVETI was observed under resting conditions (p less than 0.03). The recovery rate of the basal finger skin temperature after local cooling was slower in vibration workers with VWF than in those without VWF (p less than 0.05) and in the controls (p less than 0.001). Platelet aggregation indices were similar in all groups studied. The results suggest that the level of sympathetic nervous activity is higher in vibration-exposed workers than in controls. In subjects with VWF, sympathetic hyperactivity in combination with local factors such as vibration-induced hyperresponsiveness to cold of the digital vessels may be responsible for finger blanching attacks.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1986

Cardiovascular responses of vibration-exposed workers to a cold provocation test.

Hemodynamic functions and changes in sympathetic nervous activity were assessed in 50 vibration-exposed workers without vibration-induced white finger (VWF), in 13 subjects with VWF, and in 41 referents. Indices of systolic time intervals such as the electromechanical systole index (QS2I) and the left ventricular ejection time index (LVETI) were found to be significantly shorter in the vibration workers than in the referents both at rest and during a cold provocation test. A significant inverse relationship between urinary levels of free catecholamines and the duration of the LVETI was observed under resting conditions. The recovery rate of the basal finger skin temperature after cold provocation was slower in the vibration-exposed workers than in the referents. The indices of platelet aggregation were about the same in all the groups studied. The results of this investigation suggest that cardiac sympathetic tone and digital vascular reactivity to cold are increased in vibration-exposed workers.

Catecholamines↗
PubMed1985

Relation of haemostatic function, neurovascular impairment, and vibration exposure in workers with different stages of vibration induced white finger.

Haemostatic function and neurovascular symptoms were investigated in 67 workers exposed to vibration and 46 comparable referents. Of these 65.6% of vibration workers complained of neurological disturbances (stages 0T, 0N of Taylor's classification for vibration induced white finger (VWF) and 20.9% suffered from Raynaud's phenomenon (stages 1-2-3). The severity of the staging symptoms showed a close relation with an index of vibration dose computed on the basis of vibration measurement and individual exposure time. Indices of platelet aggregation, both in vitro and in vivo, antithrombin III, fibrinogen and fibrinopeptide A levels were not different in the exposed workers compared with the referents. No relation was found between haemostatic parameters and the severity of VWF. Exposed workers responded to a cooling procedure with a more pronounced vasoconstriction in the digital vessels than the referents, as indicated by delayed recovery time of finger skin temperature after the cold test. These findings suggest that both in the early stages (0T, 0N) and in more severe stages of VWF (stages 1-2) cold induced hyperreactivity in the digital vessels and Raynaud's syndrome are vascular disorders of functional origin occurring without any prethrombotic alterations.

Adult↗
PubMed1983

Platelet function and clotting parameters of vibration-exposed foundry workers.

Platelet aggregation and blood clotting parameters were studied in 22 workers (84 %) using pneumatic riveting and grinding hand tools and in 20 workers (90 %) not exposed to vibration but comparable with respect to age, anthropometric data, smoking and drinking habits, and atherogenic risk factors. The weighted acceleration levels of the vibrating tools are reported. According to Taylor's grading system for vibration-induced white fingers, 15 exposed workers (57 %) were in stage OT, 9 (34 %) in stage 0N, and 1 (4 %) in stage 1. Between the reference and the vibration-exposed groups no differences in the platelet aggregation indices both "in vitro" (adenosine-diphosphate, epinephrine, threshold adenosine-diphosphate concentration) and "in vivo" (platelet factor four, beta-thromboglobulin) were found. In addition the clotting parameters (prothrombin index, activated partial thromboplastin time, fibrinogen, antithrombin III) and the immunoglobulins G, A, and M were normal in the two groups. The measurement of skin temperature of the third right finger before and after the cold provocation test showed that the vibration exposed workers experienced a stronger vasoconstriction of the digital vessels than the referents. It is concluded that, in the early stages of vasospastic disorders, segmental vibration can induce peripheral vascular hyperreactivity without changes in the platelet function and clotting parameters.

Adult↗
PubMed1980

Epidemiological survey of shipyard workers exposed to hand-arm vibration.

All 169 caulkers employed at a ship yard were examined to determine the prevalence of vibration syndrome due to pneumatic portable tools (chipping hammer and grinders). Vibration measurements and medical investigations were performed in the field between September 1977 and July 1978. Vibration spectra recorded on pneumatic tools were compared to ISO Draft Proposal No. 5369. The chipping hammer produced the highest acceleration levels and exceeded the maximum ISO limits even for a short exposure time (30 min per shift). The results of medical investigations pointed out that 78.7% of caulkers experienced paresthesia in their hands, 31.3% Raynaud's phenomenon (or VWF), 20.1% presented with radiological signs of osteoarthritis at wrist and shoulders, 10.0% with olecranon exostoses, and 31.3% with cysts of the carpal bones. To diagnose VWF the skin temperature of the hands were recorded in all 169 caulkers and 60 controls at the shipyard. The basal skin thermometric map (recorded in 16 positions per hand) demonstrated an average difference of 2-2.5 degrees C between the two populations. The thermometric curve, monitored every 3 min for 40 min after a provocative cold-test (immersion of hands and wrists in melting ice for 2 min), well differentiated workers exposed and not exposed to vibrations. The authors emphasize that skin temperature (before and after the cold-test) are suitable for epidemiological purposes to compare the prevalence rates of VWF in control-experimental groups.

Adult↗
PubMed1975

[Electrocardiographic features and vectorial analysis of cardiac potentials in electric shock-induced ventricular fibrillation (author's transl)].

The authors examined the electrocardiographic features of ventricular fibrillation and other ventricular paroxysms induced by electric shock in the guinea pig. The analysis of the electrocardiographic patterns, as well as the vectorial study of the cardiac potentials during repeated episodes of ventricular "anarchy" induced in more than forty animals, showed the following data: 1. following electric shock, ventricular paroxysms appear, featuring paroxysmal tachycardia, typical or impure flutter, tachycardia--either "torsade de pointe" or "spindle" type, and typical ventricular fibrillation. Such different electrocardiographic patterns represent evolutive stages of electric activity disorganization, leading to a complete ventricular "anarchy". Such steps may reverse when reorganization of the electric activity and spontaneous defibrillation occur; 2. an attempt can be made at present to classify ventricualr paroxysms, thus eleminating semeiotic and semantic errors, still present in the literature, and providing a standardization of both nomenclature and electrocardiographic interpretation; 3. during fibrillation, the mean ventricular rate decays, featuring an exponential curve. This phenomenon accounts for a metabolic depletion of the myocardium: the higher the number of fibrillation episodes previously induced and subsided (either spontaneously or not) in the same animal, the faster the course of the phenomenon; 4. the vectorial analysis of the fibrillation potentials and, particularly, the graphic construction of "depolarization" and "repolarization" vectorcardiograms, in the differenttypes or variants of ventricular paroxysms, show that the basic mechanisms leading to ventricular electric activity disgregation are the multiple re-entry and the irregular spreading of the activation front; 5. on the basis of the acquired data, the authors believe that the "circus movement" theory (Wiggers) is still the most suitable for explaining the onset and the evolution of ventricualr fibrillation.

Animals↗
PubMedDate not supplied

Residential radon and risk of lung cancer in an Italian alpine area.

To evaluate whether residential radon exposure explains the excess mortality for lung cancer in an Italian alpine valley with high natural radioactivity, the authors conducted a population-based case-control study on 138 deceased cases and 291 sex- and year-of-birth-matched controls. Year-long alpha-track measurements of radon were performed in the most recent residence, and information about occupational history and lifetime smoking habits was obtained. The authors adjusted for smoking, and radon was associated with lung cancer risk among men: compared with a radon level of < 40 becquerels (Bq) per cubic meter (m3), the odds ratios for 40-76 Bq/m3, 77-139 Bq/m3, 140-199 Bq/m3, and 200+ Bq/m3 were 2.1, 2.0, 2.7, and 1.4, respectively. The association between radon and lung cancer, as determined with a multiplicative model, was found only among male smokers.

Aged↗
PubMedDate not supplied

[The hand-arm vibration syndrome: (I) the clinical picture, exposure-response relationship and exposure limits].

Part I of this paper presents an overview of the medical aspects of the hand-arm vibration syndrome, as well as the relationship between occupational exposure to hand-transmitted vibration and the vascular, neurological, and musculoskeletal disorders occurring in the upper limbs of workers who use vibrating tools. There is epidemiologic evidence for an increased occurrence of peripheral sensorineural and vascular disorders in occupational groups using a great variety of vibrating tools. An excess risk for wrist osteoarthrosis and elbow arthrosis and osteophytosis has been reported in workers exposed to shocks and low frequency vibration of high magnitude from percussive tools. To date, the available epidemiologic data are insufficient to outline an exposure-response relationship for both sensorineural disturbances and bone and joint disorders caused by hand-transmitted vibration. The association between vibration white finger (VWF) and exposure to hand-transmitted vibration has been clearly established in both cross-sectional and longitudinal studies of vibration-exposed workers. A proposal of exposure-response relationship for VWF is included in an annex to ISO 5349 (1986). However, the shape of the relationship between vibration exposure and VWF is not yet fully understood. The results of several epidemiologic studies seem to indicate that the current ISO frequency-weighting may be inappropriate for all types of vibration and for all kinds of vibration injury. Alternative exposure-response relationship for VWF have been suggested in recent epidemiologic investigations. Regarding exposure limits for hand-transmitted vibration, the findings of clinical and epidemiologic studies have shown that the vibration exposure levels proposed by the European Directive for physical agents are sufficiently protective for the safety and health of workers exposed to hand-transmitted vibration.

Arm Injuries↗
PubMedDate not supplied

[The hand-arm vibration syndrome: (II). The diagnostic aspects and fitness criteria].

Part II of this paper reviews the clinical and laboratory methods to diagnose the neurological, vascular and osteoarticular components of the hand-arm vibration syndrome. The prognosis and reversibility of vibration-induced neurological and vascular disorders after cessation of vibration exposure or the introduction of powered tools equipped with vibration isolation systems are discussed on the basis of the results of follow-up clinical investigations and longitudinal epidemiologic studies. Finally, the review debates some of the methodological aspects connected with the health surveillance of vibration-exposed workers and considers the possible medical contra-indications for prolonged exposure to hand-transmitted vibration.

Arm Injuries↗
PubMedDate not supplied

[The European Directive 2002/44/CE on the protection of workers from risks resulting from mechanical vibration].

This paper provides comments on the European Directive 2002/44/CE of 25 June 2002 on the minimum health and safety requirements regarding the exposure of workers to the risks arising from physical agents (vibration) (sixteenth individual Directive according to Article 16(1) of Directive 89/291/EEC). The European Directive on mechanical vibration was published in the Official Journal of the European Communities L 177/13 on 6 July 2002. The Directive includes the definitions of hand-arm vibration and whole-body vibration, establishes the daily exposure limit values and action values for mechanical vibration, and gives provisions related to (i) determination and assessment of risks, (ii) measures aimed at avoiding or reducing exposure, (iii) information, training, consultation and participation of workers, (iv) health surveillance of the exposed workers, and (v) derogations and transitional periods for the implementation of the obligations of employers when the daily exposure limit values are exceeded. The author discusses the strong link which exists between the assessment of risk due to vibration exposure at the workplace and the health surveillance of the exposed workers. The occupational health physician, as a specialist with expertise in human factors and in the early detection of vibration-related adverse health effects, will have an important role in the assessment of risks arising from mechanical vibration in order to implement an effective health surveillance of the exposed workers. The Member States must bring into force the requirements of the Directive no later than 6 July 2005.

Europe↗
PubMedDate not supplied

[Occupation and lung cancer risk in the province of Trieste: a case-control study].

To investigate the relationship between occupation and lung cancer, a case-control study was performed in the province of Trieste, Italy, where metallurgical and mechanical industries, dock activities and shipbuilding and ship repairing are predominant. Through the local Cancer Registry, pathology records of 938 men who died of primary lung cancer (ICD 162) in a five-year period were examined. Residential, smoking and occupational histories were obtained from interviews of next of kin of 756 cases and 756 age-matched male controls (+/- 2 years). Occupational exposures to lung carcinogens were assessed according to a job-title based approach, identifying industries/occupations with well-recognized lung carcinogen exposures (list A) and industries/occupations with suspected lung carcinogen exposures (list B). Exposure to asbestos was classified as absent, possible or definite. After adjustment for cigarette smoking (four levels) and residence (three levels), a significant association was found between lung cancer and occupations in list A (RR = 2.28, 95% CI = 1.70-3.07) and in list B (RR = 1.33, 95% CI = 1.04-1.71). A significant excess risk was found for workers with definite exposure to asbestos when compared to those with no exposure to lung carcinogens (RR = 1.99, 95% CI = 1.43-2.76). A very high relative risk was observed among heavy smokers with definite exposure to asbestos (RR = 42.8). A stratified analysis showed that the combined effect of asbestos and smoking was compatible with that expected under a multiplicative model. The overall attributable risk in the population (ARp) for cigarette smoking was found to be 87.6%. The ARp fraction for occupations with well-established exposures to lung carcinogens (list A) was 16.2%. The ARp fraction increased to 25.5% (85% CI = 1.4-34.6) when occupations with suspected exposure to lung carcinogens (list B) were included. The ARp fraction for possible or definite exposure to asbestos was 20.1% (95% CI = 11.6-28.6).

Adult↗
PubMedDate not supplied

[Scleroderma and occupational risk factors: a case-control study].

In a hospital-based case-referent study of systemic sclerosis (SSc) and occupational risk factors (55 cases and 171 referents), an excess risk for SSc was observed in men with previous occupational exposure to solvents and certain chemicals (vinyl chloride, formaldehyde). SSc was associated, even though not significantly, with occupational exposure to solvents and silica among women. The possible role of occupational exposures in the etiology of SSc, as well as the methodological limitations of the present study, are discussed.

Case-Control Studies↗
PubMedDate not supplied

[Progress of studies promoted by the MODS collaborative group].

In industrialised countries, carpal tunnel syndrome (CTS) is considered an epidemic work-related disease. We have set up the MODS (Malattie Occupazionali Da Sovraccarico biomeccanico, biomechanical overload-related occupational diseases) collaborative group, formed by epidemiologists, ergonomists and occupational physicians to investigate CTS in Italy, applying the methods that epidemiologists commonly use to understand epidemics. Several studies are already ongoing. Two different descriptive studies based on current hospitalisation data are in the reporting phase. A pilot case-control multicentre study (260 cases and 520 controls in 13 centres) is in the final phase of data collection. A longitudinal study on a cohort of 3000 subjects exposed to different risk factors has reached the third year of follow-up. Moreover, a surveillance system has been set up to cover selected districts of the Emilia Romagna region. These studies will generate new information about the prevalence and incidence of CTS in Italy, along with identification of regional, high-risk job titles and work sectors, and the relative influence of non-occupational factors.

Adolescent↗