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Biomedical subjects

D Brune

Publications and source records attributed to D Brune.

17 recordsLinked to original sources
PubMed1992

The ICOH and IUPAC international programme for establishing reference values of metals.

In cooperation with the ICOH Scientific Committee on the Toxicology of metals and IUPAC Commission on Toxicology, we have developed evaluation criteria for derivation of reference values for metal concentrations in human tissues and fluids. In a first attempt to illustrate how these criteria may be used, tentative reference values for mercury in human blood were derived. For persons who do not eat fish, a mean value of 10 mumol/1 (2 micrograms/1) was suggested. It was pointed out, however, that this value was based on information that did not meet the desired quality requirements, which, unfortunately were not met by any of the published reports.

Animals↗
PubMed1992

Prostate cancer treated by radiotherapy: a multivariate study.

According to respective proportions of evolutive status groups, results of multivariate studies are difficult to interpret. Among the 1099 cases of local form of prostate cancer, treated by radiotherapy from 1975 to 1982 in 16 French Anticancer Institutes, we can observe two homogeneous status groups of patients: disease-free survivors (285 cases) and patients who died of prostate cancer (278 cases). These correspond to 51% of the whole population. Among other things, they are comparable in size, for age at the beginning of radiotherapy and for delay between histologic diagnostic and radiotherapy. We chose to analyse them using multivariate analysis. To take survival into account, we used a Cox model and Kaplan-Meier curves; the group deceased of prostate cancer was further analyzed by a tree-structured regression method. The Cox model and the Kaplan-Meier curves confirmed two main explicative factors: Stage (p < 0.0001) and tumor grade (p < 0.001). Poorer evolution occurs in extracapsular forms and grade I has better survival than others. The tree-structured regression method indicates two other pejorative factors: hormonotherapy prior to radiotherapy and the presence of cardiovascular pathology. Though the pelvic dose does not appear to be a main explicative factor, it seems to improve survival and delay between radiotherapy and recurrence or metastasis in some categories of cases. Other factors such as tumor dose, age and delay between diagnosis and radiotherapy were not found to be significant. These results cannot be extended to the whole population for which they do not constitute a predictive study. We consider them as "baseline data".(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1991

A review of normal concentrations of mercury in human blood.

The present survey is a critical review and quality grading of 98 publications in the international scientific literature presenting mercury concentrations in human whole blood, blood cells and plasma of individuals who have not been occupationally exposed to mercury ("normal values"). Most of the papers reviewed were published after 1976 and were found in the Medline database. Additional information has been obtained in response to requests addressed to scientists with high reputation from different parts of the world working in the field of trace element analysis. The evaluation system includes separate grade scales for sampling and chemical analysis. In no case were the requirements justifying the highest Grade 1 i.e. superior quality, fulfilled. Most reports suffered from various degrees of a lack of information concerning description of individuals, diet, experimental design or analytical and statistical treatment. Nineteen papers were rejected because of insufficient information or obvious erroneous sampling or analytical treatment (Part I). The influence on blood mercury level of various non-occupational exposures, particularly fish consumption, but also medication with mercury-containing drugs, presence of amalgam restorations, etc., has been surveyed. The levels have been systematized according to such parameters. The evaluated and systematized data have been stored in a PC database "Tracy", which includes information about concentrations of total, inorganic or organic mercury in whole blood, blood cells or plasma. Mercury in maternal-cord blood is also included. One hundred and thirty-two data sets from 79 reports were included in the database (Part II). Because of the shortcomings of the available information, only tentative reference values for mercury in whole blood, blood cells and plasma were established (Part III). There is an obvious need for additional high-quality data.

Humans↗
PubMed1988

Multielemental assay of tissues of deceased smelter workers and controls.

Concentrations of 23 elements in lung, liver and kidney from deceased smelter workers are compared with those from rural and urban controls. The analyses were made by neutron activation analysis and atomic absorption spectrophotometry. Significantly higher levels of antimony, arsenic, cadmium, chromium, cobalt, lanthanum, lead and selenium were found in the smelter workers lungs (n = 85) compared with the rural controls (n = 15). Significantly higher concentrations of antimony, arsenic and lead were observed among all smelter workers compared with urban controls (n = 10). The highest increase, about 11-fold, was found for antimony in smelter workers compared with non-exposed controls. A six-fold increase was noted for arsenic. Workers who died from lung cancer (n = 7) had the lowest lung selenium content relative to concentrations of other metals, both compared with other disease categories among the workers (GI-cancer, other cancers, cardiovascular diseases, cerebrovascular diseases, other causes) and with the two control groups. The low lung selenium concentrations may have influenced the development of lung cancer. The highest lung tissue levels of cadmium were found in the lung cancer group. Smokers and ex-smokers were over-represented in this group and tobacco is a known cadmium source. The highest, or one of the highest, lung values for some of the other metals (antimony, arsenic, cadmium, lanthanum and lead) were observed in one or several of the lung cancer cases. Metal concentrations in liver (metabolism) and kidney (excretion) reflect the systemic distribution. The highest cadmium levels in the liver and the lowest selenium content in the kidney were found among the lung cancer cases. A multifactorial genesis for the development of lung cancer is concluded from this study, which visualizes the need for systematic health surveillance and follow-ups both in active and retired workers.

Aged↗
PubMed1988

Radiation therapy of carcinomas of the skin of nose and nasal vestibule: a report of 1676 cases by the Groupe Europeen de Curiethérapie.

A retrospective multicentric analysis of the results of irradiation of 1676 carcinomas of the skin of the nose and nasal vestibule was performed by the Groupe Européen de Curiethérapie (Tunis, May 1986). Overall local control was 93% with a minimum follow-up of 2 years. Local control is dependent on the tumor size (diameter less than 2 cm: 96%, 2-3.9 cm: 88%, greater than or equal to 4 cm: 81%), and tumor site (external surface of the nose: 94%, vestibule: 75%). Local control was independent of histology for smaller tumors, but for those larger than 4 cm, basal cell carcinomas were more frequently controlled than squamous cell carcinomas. Recurrent tumors are less frequently controlled than those being treated for the first time (88 vs. 95%). There were few complications and cosmetic results were generally satisfactory. The results of implantation, orthovoltage and megavoltage irradiation are compared with respect to local control, complication rate and cosmesis. Implantation is usually the treatment of choice for vestibular tumors but for those of the external surface the choice depends on the tumor diameter. Implantation and orthovoltage irradiation are equivalent for tumors less than 2 cm. For those from 2 to 3.9 cm, the results of orthovoltage irradiation may be satisfactory in a selected population but implantation is usually more suitable for tumors with rapidly changing contour.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1986

[Para-aortic lymphadenectomy in the surgical evaluation of ovarian cancer].

Lymph node involvement was demonstrated by para-aortic lymphadenectomy in 6 out of 20 women treated for ovarian cancer with macroscopically limited lesions at first and second-look laparotomy. When added to those reported in the literature, these results suggest that 20% of stages I and II ovarian cancers involve the lymph nodes, which considerably influences the prognosis and treatment of cancers otherwise considered as limited. We therefore suggest that biopsy of the lumbar aortic lymph nodes should be systematically performed in the surgical evaluation of ovarian cancers at an early stage.

Biopsy↗
PubMed1979

Elements in minor or trace quantities in zinc phosphate cements.

Eight powders and two liquids of zinc phosphate cements have been analyzed by optical emission spectrography for the purpose of characterizing elements in minor or trace quantities. The following elements were measured: bismuth, boron, cadmium, chromium, copper, iron, lead, silver and titanium. The content of any of these elements did not exceed the level of 0.1%. The amounts of such elements which might be transferred to the gastrointestinal tract associated with dissolution from unsuccessful restorations have been considered.

Digestive System↗
PubMed1979

Levels of mercury and silver in dust from the trimming of amalgam dies.

The levels of mercury and silver in dust arising from the trimming, i.e. grinding, of amalgam dies in dental laboratories have been measured. In breathing air close to the workpiece, the mercury and silver contents exceeded the threshold limit values for short-term exposure by factors of aboit 60 and 400 in cases when local ventilation was not in use. With efficient local exhaust systems enabling a dust reduction of about 94%, the short-term exposure limit values for mercury and silver were exceeded by factors of about 4 and 20 respectively. Mercury and silver were assayed quantitatively by means of nuclear chemical analysis. A major part of the amalgam dust consisted of respirable particles. The collected dust comprised about 80% amalgam and 20% particulate matter from grinding wheels and stones according to SEM and EDAX measurements.

Air Pollutants↗
PubMed1979

Toxic elements in silicate cements.

Six brands of silicate cements have been characterized by means of optical emission spectrography with respect to the contents of elements in minor or trace quantities in a search for presence of possible toxic elements. Beryllium was observed in two powders at levels of 1.3 and 1.6% Cadmium was found in two powders at levels of 0.02 and 0.03%. Lead was measured in three powders at levels of 0.001-0.003%. Bismuth, boron, copper, gallium, iron, manganese, titanium, tin and zirconium were found in various brands in either powder or liquid at levels of 0.001-0.1%. Upper limits of the amounts of the various elements that might be transferred to the gastrointestinal tract after dissolution of the cement matrix in the oral cavity have been calculated.

Beryllium↗
PubMed1978

Microprobe analysis of lead in human femur by proton induced X-ray emission (PIXE).

A method is described for the measurement of the distribution of lead in bone tissue. Two cases of human femur have been analyzed; one worker was exposed to lead in heavy metal industry, the other case presents a reference worker from the same environment not excessively exposed to lead. Lead was determined through proton induced X-ray emission using microprobe technique. The mean lead concentration in the poisoned and the reference case was 70 and 30 ppm, respectively. The reference case showed an even lead distribution in the femur, while the poisoned case exhibited peaks in the distribution indicating that exposure to lead was not evenly distributed. The described technique has potential for microanalysis within the Haversian system for recording the history of exposure.

Bone and Bones↗
PubMed1978

Mercury vapor levels in a dental laboratory.

Mercury vapor levels associated with grinding amalgam models and mulling amalgams in the palm of the hand following trituration have been measured in a dental laboratory in inhalation position. The threshold limit value of airborne mercury of 0.05 mg/m3 was essentially exceeded in the grinding procedure of amalgam. Levels in excess of seven times this value were recorded. During mulling the mercury vapor level fluctuated around the threshold limit value. The mean mercury concentrations did not essentially exceed the threshold limit value.

Air Pollutants↗
PubMed1978

Levels of airborne particles resulting from handling alginate impression material.

The levels of airborne particles emanating from handling alginate impression powders have been surveyed. The concentrations of powders, lead and silicious particles in the aerosol have been measured after thoroughly shaking the containers before opening. The decrease of the powder concentration in the ambient air as a function of time has been estimated. The efficiency of face masks to protect against powder exposure has been investigated.

Aerosols↗
PubMedDate not supplied

[Age at the time of the first birth: a variable with simple, double, or triple significance in breast cancer studies].

I.--The inverse relationship of risk with parity is one of the earliest known features of the epidemiology of human mammary cancer. But recently knowledge of this relationship was refined when Mac Mahon and his colleagues found that the protective effect is actually correlated to the age of the mother at the first birth rather than to the total number of children, so that a woman who has a child before the age of 18 is one third as likely to suffer breast cancer in later life as a woman first delivered at 35. II.--A study was undertaken in the Centre Francois Baclesse on the hypothesis that age at first birth may also be related to the age of the patient at clinical onset of the mammary malignancy. One would expect to find a retardative effect of early delivery since this factor was found to be protective as far as mammary cancer risk is concerned. The conclusions of our investigations are in complete opposition to the original hypothesis: in our series, breast cancer appears to occur significantly earlier in women whose first delivery occurred early. III.--Thus the same process appears to be protective as far as total mammary cancer risk is concerned but accelerating as far as age at tumor onset is concerned. These apparently inconsistent observations led to the hypothesis that both studies might express the same biologic process which, in the case of early delivery, inhibits the mechanism of carcinogenic induction and therefore reduces the total number of cancer but which subsequently quickens the evolution of the inducted disease. Such a conjecture implies that breast cancer should be more severe following early first birth. The analysis of our series, as well as the series of Ontario Cancer Clinics, substantiates this hypothesis. But these conclusions are built on indirect proofs or direct proofs which are still short of statistical significance.

Adolescent↗