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Biomedical subjects

A Cavalleri

Publications and source records attributed to A Cavalleri.

At least 55 records · Page 3Linked to original sources
PubMed1990

Diurnal variation of testosterone and estradiol: a source of bias in comparative studies on breast cancer.

In this paper we present a study of the diurnal variation of testosterone (T) and estradiol (E2) in women, carried out as part of the design of a prospective study on the hormonal and nutritional etiology of breast cancer. Blood samples were obtained 5 times on the same day, in the morning and early afternoon, from 23 women aged between 25 and 63 yr. Twelve were sampled within the first days following daylight-saving time (SUMTI) introduction. In postmenopause, T mean values decreased from 08:00 h to 15:00 h and the effect of blood drawing time was statistically significant (p less than 0.01), with no significant effects of SUMTI. For E2 mean values, no significant effect was found for either blood drawing time or SUMTI. In premenopause, T mean values decreased from morning to afternoon (p less than 0.01), while no effect of SUMTI was found. A significant decrease was observed for E2 during the day (p less than 0.01), with no significant influence of SUMTI. These results indicate that diurnal variation of T and E2 are such, that one must not neglect the possible effects of timing procedures on hormonal measurements, when hormonal hypotheses are tested in comparative studies on cancer etiology.

Adult↗
PubMed1989

Androgens and breast cancer in premenopausal women.

We investigated the role of androgens in premenopausal breast cancer by comparing serum testosterone, dihydrotestosterone, androstenedione, dehydroepiandrosterone sulfate, progesterone, sex-hormone-binding globulin-binding capacity, and urinary testosterone and androstanediol in 63 women with breast adenocarcinoma and 70 healthy controls of similar age. With variables dichotomized at the 75th percentile, the age-adjusted relative risk was 3.4 (95% confidence interval, 1.6-7.3) for high versus low levels of serum testosterone, 2.1 (0.9-4.8) for urinary testosterone, and 2.5 (1.1-5.9) for serum dihydrotestosterone. We observed no differences in other hormones. The strength of the associations changed markedly with increasing time to the onset of the next menses. The risk for testosterone and dihydrotestosterone, which was negligible in women with onset within 5 days of sampling, increased progressively to nearly 10-fold higher than in unstratified data in women with onset 10 days or more after sampling. This study provides arguments in favor of a role for increased androgenic activity in premenopausal breast cancer. It also suggests that unknown factors related to cycle length may be important in modulating the strength of the association with testosterone. The results are discussed also in reference to possible biases and inadequacies in study design.

Adult↗
PubMed1988

Chromium in urine, serum and red blood cells in the biological monitoring of workers exposed to different chromium valency states.

Using personal air sampling exposure to hexavalent and trivalent chromium was measured in 22 workers mainly exposed to Cr(VI) and in 15 workers mainly exposed to Cr(III) as basic chromium sulphate. Determination of Cr(VI) in the urine of all the subjects using a selective technique by ETA-AAS and liquid anion exchangers failed to show detectable amounts of the hexavalent form, the detection limit of the technique being 0.05 micrograms/L. A clear relationship between exposure and postshift urinary total chromium was found in subjects exposed to Cr(VI), while urinary levels in workers exposed to chromic sulphate high concentration proved lower. Determination of total chromium in serum and red blood cells showed a significant increase of chromium levels in erythrocytes of workers exposed to Cr(VI) while in subjects mainly exposed to Cr(III) an increase of the serum fraction was observed. The results demonstrate that Cr(III) is absorbed through the respiratory tract, but its kinetics and distribution in the body are not the same as for Cr(VI), and are not adequately monitored by short-term urinary determinations. Oxidation states of chromium largely influence uptake, mechanism of absorption, transport and organ distribution as well as toxicity of chromium-containing compounds. In particular, hexavalent derivatives are known to induce adverse effects, both acute and chronic, in occupationally exposed subjects, while there is little conclusive evidence for toxic effects caused by trivalent chromium compounds. Biological monitoring of exposure to chromium(VI) has usually been performed by determining total chromium levels in urine, whereas biological monitoring data in subjects occupationally exposed to Cr(III) are still scanty.(ABSTRACT TRUNCATED AT 250 WORDS)

Chromium↗
PubMed1988

Visual fatigue in video display terminal operators: objective measure and relation to environmental conditions.

The lighting conditions, luminance, contrast, and design of the workplace were studied in video display terminal (VDT) work stations operated by a group of female VDT data-acquisition clerks. VDT-induced symptoms were assessed by means of subject answers to a questionnaire. To measure VDT-induced ocular fatigue objectively, refraction power was determined before and at the end of workshift by an infrared autorefractometer. Job-induced refraction changes were then related to visual complaints and conditions in the workplace. The results confirmed that VDT data-acquisition work can lead to temporary myopia (myopization) in a remarkable percentage of operators; a significant correlation between eye discomfort, ocular asthenopia, and myopization was also found. Illumination levels, luminance, and contrast seem to be of paramount importance regarding visual symptoms: neither asthenopia nor myopization was observed when all of these conditions were adequate. If the ergonomic design of the workplace and the viewing distance are adequate, there are also usually fewer musculoskeletal symptoms. Our results suggest that changes in the ocular refraction status before and at the end of the work-shift, as determined by an automatic refractometer, provide a good objective index of VDT-induced "ocular fatigue", which in our study proved to be significantly related to workplace conditions.

Asthenopia↗
PubMed1988

Serum type III procollagen peptide in asbestos workers: an early indicator of pulmonary fibrosis.

Serum type III procollagen peptide (PIIIP) concentrations were determined in 36 male workers exposed to asbestos fibres in the production of asbestos cement items and in 13 healthy male controls. Mean (SD) PIIIP serum concentrations were 9.3 (1.5) ng/ml (range 7-12) in the controls and 13.7 (3.5)ng/ml (range 7.5-20) in the asbestos workers; the difference was statistically significant (p less than 0.01). The exposed workers were subdivided according to presence or absence of radiological signs of asbestosis and intensity and duration of exposure. PIIIP serum values of workers with asbestos related interstitial fibrosis were the highest of the groups at 14.6 (2.3) ng/ml. In workers with heavy exposure the PIIIP values were significantly related to duration of exposure (r = 0.95; p less than 0.01). PIIIP serum values may be a useful index for the early diagnosis of asbestos induced pulmonary fibrosis and its use should be considered as part of the biological monitoring of exposed workers.

Adolescent↗
PubMed1987

Lead level of whole blood and plasma in workers exposed to lead stearate.

In a group of 23 male workers exposed to lead stearate the levels of lead in whole blood and plasma were determined and compared to those obtained from a group of 23 subjects exposed to inorganic lead compounds. The mean values for lead in whole blood were similar in both groups, while the mean lead concentration in plasma was 0.1729 (SD 0.0677) mumol/l for those exposed to lead stearate and 0.0936 (SD 0.0577) mumol/l for those exposed to other lead compounds. The difference was highly significant. The percentage ratio for lead in plasma to lead in whole blood, which can be considered a "bioavailability index" for lead, proved to be two times higher for stearate workers than for subjects exposed to inorganic lead compounds. The data suggest that the different chemical properties of absorbed lead stearate may cause a different distribution of the metal in different blood compartments, the plasma compartment having a higher affinity for lead stearate than for other lead compounds. Because the plasma fraction has a greater bioavailability, lead stearate could induce toxic effects that differ (possibly being severer) from those caused by other lead compounds at similar absorbed doses.

Air Pollutants, Occupational↗
PubMed1985

Determination of total and hexavalent chromium in bile after intravenous administration of potassium dichromate in rats.

Total and hexavalent chromium were measured in bile samples obtained from cannulated bile ducts of male rats iv administered with potassium dichromate at various doses corresponding to 0.1, 0.5, and 1 mg of chromium. The evaluation of the hexavalent form was performed by separation with a liquid anion exchanger and electrothermal atomization-atomic absorption spectrophotometric determination. Within 2 hr 1.35-2.23% of the chromium injected was recovered in bile as total chromium, the hexavalent form accounting for less than 1% of the total chromium collected, which seems almost entirely excreted as trivalent chromium. Since Cr(VI) administered iv was quickly reduced to Cr(III) in blood, the possibility exists for chromium in trivalent form to penetrate into the liver cells and to be excreted in the bile, possibly by binding to a carrier such as the low-molecular-weight substance described by Yamamoto et al. (A. Yamamoto, O. Wada, and T. Ono, Toxicol. Appl. Pharmacol. 59, 515, 1981).

Animals↗
PubMed1985

[Serum and erythrocyte chromium distribution and urinary elimination in persons occupationally exposed to chromium (VI) and chromium (III)].

With personal air samplers exposure to hexavalent and trivalent chromium was measured in 17 workers mainly exposed to Cr (VI) and in 7 workers mainly exposed to Cr (III) as basic chromium sulphate. Determination of Cr (VI) in urine of all the subject using a selective technique failed to show detectable amounts and postshift urinary total chromium was found, while urine levels of of workers exposed to chromic sulphate were not related to Cr. (III) air concentrations. Determination of total chromium in serum and red blood cells showed a significant increase of chromium levels in erythrocytes of workers exposed to Cr (VI) while in subjects mainly exposed to Cr (III) an increase of the serum fraction was evidenced. The results demonstrate that Cr (III) is absorbed through the respiratory tract but its kinetics and distribution in the body are different in comparison to Cr (VI) and not adequately monitored by short-term urinary determinations.

Animals↗
PubMed1984

Lead in cerebrospinal fluid and its relationship to plasma lead in humans.

Lead levels in whole blood, plasma and cerebrospinal fluid (CSF) were determined in 18 patients suffering from Amyotrophic Lateral Sclerosis (ALS) and in 21 subjects hospitalized for neurological investigations. No significant differences were found for blood, plasma and CSF lead concentration between the ALS group and the other patient group. The plasma lead-CSF lead mean ratio was greater than 1 in both groups, while in subjects with a slight degree of blood-CSF barrier impairment a significant decrease of the ratio was demonstrated. A significant relationship between plasma lead and CSF lead levels (r = 0.405; p less than 0.01), but not between whole blood lead and CSF lead levels, was established. Lead levels in CSF were also age-related (r = 0.485; p less than 0.05) in the group of patients not suffering from ALS. In subjects with normal blood-brain barrier permeability, lead in plasma is a good indicator of CSF lead concentration.

Adult↗
PubMed1983

Abnormal serum hormone levels in lung cancer.

Serum levels of chorionic gonadotropin (HCG), testosterone, luteinizing hormone (LH) and prolactin were evaluated with the radioimmunoassay in 59 patients with lung cancer, 10 patients with benign lung disease, and 37 normal controls. HCG was present in 6.8% of the lung cancer patients but in none of the subjects of the other two groups. Prolactin and LH levels were significantly higher than normal in lung cancer patients (respectively p less than 0.001 and p less than 0.01) as well as in patients with benign lung disease (p less than 0.01 for both the hormones). Testosterone levels were significantly lower than normal in patients with lung cancer (p less than 0.05) but not in those with benign lung disease. When the patients were analyzed according to histologic type and clinical stage of disease, significantly lower than normal values of testosterone were found in patients with small cell carcinoma or squamous cell carcinoma. In the squamous cell carcinoma group, the patients with lymph node metastases had significantly lower testosterone levels than those without lymph node metastases. From these results, we may hypothesize that the raised levels of prolactin and LH are related to a pulmonary pathology, not necessarily neoplastic, whereas the low levels of testosterone are related to the presence of the tumor.

Adenocarcinoma↗
PubMed1983

Circulating levels of testosterone, 17 beta-oestradiol, luteinising hormone and prolactin in postmenopausal breast cancer patients.

Serum testosterone, 17 beta-oestradiol, luteinising hormone (LH) and prolactin were measured in 28 postmenopausal breast cancer patients after mastectomy and in 30 postmenopausal normal controls. In the patient group, mean levels of oestradiol, LH and prolactin did not differ significantly from those of the control group. Mean testosterone levels were higher in breast cancer patients than in normal controls, either considering the overall groups (P less than 0.001) or dividing them into subgroups according to years since menopause. Breast cancer patients were divided into 2 subgroups according to time since mastectomy: 19 patients had been examined within a year of mastectomy and 9 patients some years after mastectomy. Testosterone, but not oestradiol, LH or prolactin values in each subgroup were still significantly higher (P less than 0.001 and P less than 0.02, respectively) than in normal controls. Years since menopause were significantly correlated with testosterone (r = 0.533, P less than 0.01) but not with the other hormones in the cancer group. These results confirm our previous findings of increased urinary testosterone values in postmenopausal breast cancer patients and support the hypothesis that androgens may play a role in the development of breast cancer.

Aged↗
PubMed1983

Increased urinary androgen excretion is a hormonal abnormality detectable before the clinical onset of breast cancer.

Six patients who developed breast cancer between the ages of 27 and 55 years had been examined for their urinary excretion of testosterone and androstanediol 17 to 69 months before the clinical onset of their cancer. Each of them showed higher than normal excretion values of testosterone or androstanediol, or both. At the time of hormonal examination, the patients were considered at risk for breast cancer because their history had included one or more of the following factors: previous mammary disease, familiality, sterility or subfertility, menstrual cycle irregularities. On the basis of this evidence, it would seem that high androgenic activity is a risk factor for developing breast cancer in patients with the "adverse" history.

Adult↗
PubMed1983

Increased urinary androgen levels in patients with carcinoma in situ of the breast with onset while taking oral contraceptives.

Urinary testosterone, androstanediol, ethiocolanolone, and androsterone glucuronide were determined by use of gas chromatography in four patients with carcinoma in situ of the breast. In all the patients, one or more of these hormones were higher than normal. This finding supports previous reports from our laboratory of increased androgen excretion in patients with fibrocystic disease or infiltrating carcinoma of the breast. Carcinoma in situ arose while the four patients were taking oral contraceptives. The progestational component of the pill, a nonderivative of testosterone, may carry with it some androgenic properties. This fact and the discovery of increased androgen excretion levels in these four patients led us to suppose that androgens could play a role in the development of breast cancer.

Adolescent↗
PubMed1982

Effects of lead on the visual system of occupationally exposed subjects.

A quantitative measurement of visual field in mesopic adaptation was performed for 35 workers occupationally exposed to lead and 35 referents matched for age, smoking, and alcohol consumption. The mean level (+/- SD) of lead in blood was 47 +/- 16 microgram/100 ml (2.25 +/- 0.77 mumol/l) [range 21-82 microgram/100 ml (1.01-3.94 mumol/l)]. In 10 exposed subjects a central scotoma was found that was not evidenced in any of the referents. A highly significant decrease in visual sensitivity was observed for the exposed subjects a central scotoma was found that was not evidenced in any of the referents. A highly significant decrease in visual sensitivity was observed for the exposed subjects. The results point to damage of central and peripheral optic nerve fibers. In the most severe cases, central vision is preferentially affected, and therefore the results are suggestive of subclinical optic neuropathy.

Adult↗