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Biomedical subjects

O Sala

Publications and source records attributed to O Sala.

At least 19 recordsLinked to original sources
PubMed1994

Cobalt exposure in 'hard metal' and diamonds grinding tools manufacturing and in grinding processes.

Cobalt is considered to play a major role in the development of 'hard metal' interstitial lung disease, asthma and other adverse health effects. A survey of occupational exposure of workers is a fundamental step to obtain exposure-response information and for preventive action. Process related exposure assessment was performed before and after technical control in small and medium size factories in a large surveillance programme. Cobalt containing airborne dusts were sampled by performing multiple measurements at the workplace of each process in which the types of job and duration of exposure were similar. Samples were analyzed by atomic absorption spectroscopy. Very high exposure levels encountered before technical control were significantly lowered with efficient local exhaust ventilation plant in 'hard metal' and grinding processes, but sometimes the TLV of 0.05 mg/m3 were exceeded. In the manufacture of grinding tools, major steps in cobalt control by local ventilation was not able to keep exposure below the TLV; exposures from 0.12 to 0.75 mg/m3 were recurrent and these need control strategies.

Air Pollutants, Occupational↗
PubMed1994

Exposure to cobalt in the welding process with stellite.

In some small factories producing moulds for ceramic tiles using a cobalt alloy (stellite), environmental and biological (CoU) monitoring was conducted for eight workers employed in gas-shielded arc (MAG) and oxy-acetylene welding processes. During oxy-acetylene braze-welding, the exposure to cobalt is very low as are urinary cobalt concentrations. On the other hand, during the MAG welding process, the exposure levels can exceed the TLV-TWA levels and correlated well with CoU at the end of a working shift. Two MAG welders followed for two consecutive weeks, showed different patterns of urinary cobalt excretion: under the same environmental conditions, the higher CoU was found in the worker with greater past exposure. This aspect needs further evaluation before adopting CoU as a current indicator of occupational exposure to the metal.

Air Pollutants, Occupational↗
PubMed1994

Cobalt powdersintering industry (stone cutting diamond wheels): a study of environmental-biological monitoring, workplace improvement and health surveillance.

This communication deals with an aspect of occupational hygiene in a factory producing granite cutting diamond wheels by sintering, in moulds, of fine cobalt powder. The factory has been studied between 1988 and 1991; the Department of Preventive and Occupational Medicine of the Local Sanitary Unit of Reggio Emilia has followed the evolution of the local exhaust ventilation equipment supplied by the employer in that period. At the same time, the following measurements and observations were carried out: (a) cobalt exposure by personal sampling, (b) airborne cobalt measurements by area sampling, (c) biological monitoring of cobalt in urine, (d) health surveillance.

Adult↗
PubMed1976

Tumour-host relationship and its implications in the treatment and long-term prognosis of laryngeal cancer. Critical observations on the TNM system of tumour classification.

The choice of surgical and/or X-ray treatment of a laryngeal cancer is usually established by taking into consideration the site of the tumor and its extension. The histologic type is considered only when this is easily identifiable, whereas the histologic grade of cellular differentiation and the tumour-host relationship are always erroneously disregarded. These latter factors are of a basic importance in establishing a "tailor-made" therapeutic programme for each patient and the long-term prognosis. The above factors have led to a new critical approach to laryngeal cancer and have also made it possible to obtain some practical results: 1 degrees the correct definition of the verrucous squamous cell carcinoma of the larynx, which is the result of the highest local defensive reaction to tumour growth (mediated by thymus-dependent lymphocytes); 2 degrees a criticism of the present trend to perform a more conservative surgery decided only opon the basis of the site and extension of the neoplasm; conservation surgery must be adopted for patients with an intense cellular immune response around the tumour and with a moderate histologic grade of malignancy; 3 degrees a criticism of the present criteria in establishing the long-term survival, which do not include the early immune response; 4 degrees the necessity of a systematic histologic study of the surgical specimen so as to evaluate the intensity of the immune reaction both around the tumour and in regional lymph nodes. In the light of these new data, the TNM system of tumour classification is now outdated, as witnessed by the constant efforts to adapt it to the unpredictable behaviour of malignant disease.

Carcinoma, Squamous Cell↗
PubMedDate not supplied

Morphological observations of immunobiology of laryngeal cancer. Evaluation of the defensive activity of immunocompetent cells present in tumour stroma.

A series of 104 patients with squamous cell carcinoma of the larynx was studied with regard to tumour-host interaction. Prognostic evaluation was based upon histologic grading and morphological evidence of host immune response, judged by the presence and degree of lymphocyte and plasma cell infiltration in tumour stroma. Histologic grade and lymphoplasma-cellular infiltration do correlate with the 5-year survival. The immune response, however, seems to be a favourable prognostic sign only for well differentiated tumours; in our series, all poorly differentiated neoplasms showed minimal or no cellular response. The survival rate increases with the increasing intensity of cellular response within each class of tumour cell differentiation. Small lymphocytes are the basic elements of cell-mediated immune response. After tumour antigenic stimulation they change into immunoblasts which in turn would produce "committed" lymphocytes which would recognize and destroy tumour cells.

Adult↗
PubMedDate not supplied

Auditory brainstem evoked responses in the clinical evaluation and follow-up of insulin-dependent diabetic subjects.

In the last few years the use of ABR in the dysmetabolic encephalopathies has aroused considerable interest. Even though brainstem involvement in these syndromes is not yet entirely understood, ABR techniques have provided new and important insights. We studied 60 insulin-dependent diabetic subjects, 29 females and 31 males aged to 17 to 55 yrs, and observed ABR abnormalities in 28.2% of the cases. This impairment affects the I-V interval or central transmission time (CTT), which is considered the most reliable index of brainstem function. The ABR pattern was considered pathologic when the CTT was due 2DS as compared with a sex- and age-matched control. Follow-up studies performed on 20 of these subjects revealed no significant variation in the ABR tracing. This fact, together with the absence or correlation between ABR involvement and metabolic control and glycemia level during the test, could be attributed to a 'structural' damage of the brainstem tissue. In diabetics, we observed a significant correlation (p less than 0.05) between I-V interval shift and an EMG-proved reduction in motor conduction velocity (MCV) of the peroneal nerve. We also found a high incidence of ABR impairment (53%) in diabetics with cardiovascular autonomic failure.

Adolescent↗