Bacterial diversity across four drinking water distribution systems in Croatia: impacts of water management practices and disinfection by-products

Several factors may impact bacterial diversity in drinking water distribution systems (DWDSs) including the origin of the raw water, the water treatment technologies, and the disinfection practices applied. 16S rRNA metabarcoding was used for the in-depth characterization of bacterial communities in the four studied Croatian DWDSs (A, B, C, D) two of which had residual disinfectant (A, B) and two were without (C, D), while only B utilized the conventional water treatment technology. Significantly higher diversity and species richness were evidenced in non-disinfected DWDSs (p<0.05) compared to disinfected DWDSs. The phylum Proteobacteria was the most abundant in all the DWDSs, being proportionately higher in non-disinfected systems (p<0.05). The most abundant genera in DWDS-A Mycobacterium and Sphingomonas both positively correlated, whereas Lactobacillus negatively correlated with the concentration of disinfection by-products (DBPs) as a sum of haloacetic acids (HAAs). Conversely, the genus Ralstonia positively correlated with the individual DBP dichloroacetic acid. These results indicate that genera Sphingomonas, Mycobacterium, Lactobacillus and Ralstonia could have an effect on promoting the formation of DBPs, in a similar manner to how negatively correlated taxa may influence their degradation.

A field-pilot for passive bioremediation of As-rich acid mine drainage

A field-pilot bioreactor exploiting microbial iron (Fe) oxidation and subsequent arsenic (As) and Fe co-precipitation was monitored during 6 months for the passive treatment of As-rich acid mine drainage (AMD). It was implemented at the Carnoulès mining site (southern France) where AMD contained 790-1315 mg L^-1 Fe(II) and 84-152 mg L^-1 As, mainly as As(III) (78-83%). The bioreactor consisted in five shallow trays of 1.5 m² in series, continuously fed with AMD by natural flow. We monitored the flow rate and the water physico-chemistry including redox Fe and As speciation. Hydraulic retention time (HRT) was calculated and the precipitates formed inside the bioreactor were characterized (mineralogy, Fe and As content, As redox state). Since As(III) oxidation improves As retention onto Fe minerals, bacteria with the capacity to oxidize As(III) were quantified through their marker gene aioA. Arsenic removal yields in the pilot ranged between 3% and 97% (average rate (1.8 ± 0.8) ✕ 10^-8 mol L^-1 s^-1), and were positively correlated to HRT and inlet water dissolved oxygen concentration. Fe removal yields did not exceed 11% (average rate (7 ± 5) ✕ 10^-8 mol L^-1 s^-1). In the first 32 days the precipitate contained tooeleite, a rare arsenite ferric sulfate mineral. Then, it evolved toward an amorphous ferric arsenate phase. The As/Fe molar ratio and As(V) to total As proportion increased from 0.29 to 0.86 and from ∼20% to 99%, respectively. The number of bacterial aioA gene copies increased ten-fold during the first 48 days and stabilized thereafter. These results and the monitoring of arsenic speciation in the inlet and the outlet water, provide evidences that As(III) oxidized in the pilot. The biotreatment system we designed proved to be suitable for high As DMA. The formation of sludge highly enriched into As(V) rather than As(III) is advantageous in the perspective of long term storage.

Biological attenuation of arsenic and iron in a continuous flow bioreactor treating acid mine drainage (AMD)

Passive water treatments based on biological attenuation can be effective for arsenic-rich acid mine drainage (AMD). However, the key factors driving the biological processes involved in this attenuation are not well-known. Here, the efficiency of arsenic (As) removal was investigated in a bench-scale continuous flow channel bioreactor treating As-rich AMD (∼30-40 mg L^-1). In this bioreactor, As removal proceeds via the formation of biogenic precipitates consisting of iron- and arsenic-rich mineral phases encrusting a microbial biofilm. Ferrous iron (Fe(II)) oxidation and iron (Fe) and arsenic removal rates were monitored at two different water heights (4 and 25 mm) and with/without forced aeration. A maximum of 80% As removal was achieved within 500 min at the lowest water height. This operating condition promoted intense Fe(II) microbial oxidation and subsequent precipitation of As-bearing schwertmannite and amorphous ferric arsenate. Higher water height slowed down Fe(II) oxidation, Fe precipitation and As removal, in relation with limited oxygen transfer through the water column. The lower oxygen transfer at higher water height could be partly counteracted by aeration. The presence of an iridescent floating film that developed at the water surface was found to limit oxygen transfer to the water column and delayed Fe(II) oxidation, but did not affect As removal. The bacterial community structure in the biogenic precipitates in the bottom of the bioreactor differed from that of the inlet water and was influenced to some extent by water height and aeration. Although potential for microbial mediated As oxidation was revealed by the detection of aioA genes, removal of Fe and As was mainly attributable to microbial Fe oxidation activity. Increasing the proportion of dissolved As(V) in the inlet water improved As removal and favoured the formation of amorphous ferric arsenate over As-sorbed schwertmannite. This study proved the ability of this bioreactor-system to treat extreme As concentrations and may serve in the design of future in-situ bioremediation system able to treat As-rich AMD.

Spatial Distribution of Eukaryotic Communities Using High-Throughput Sequencing Along a Pollution Gradient in the Arsenic-Rich Creek Sediments of Carnoulès Mine, France

Microscopic eukaryotes play a key role in ecosystem functioning, but their diversity remains largely unexplored in most environments. To advance our knowledge of eukaryotic microorganisms and the factors that structure their communities, high-throughput sequencing was used to characterize their diversity and spatial distribution along the pollution gradient of the acid mine drainage at Carnoulès (France). A total of 16,510 reads were retrieved leading to the identification of 323 OTUs after normalization. Phylogenetic analysis revealed a quite diverse eukaryotic community characterized by a total of eight high-level lineages including 37 classes. The majority of sequences were clustered in four main groups: Fungi, Stramenopiles, Alveolata and Viridiplantae. The Reigous sediments formed a succession of distinct ecosystems hosting contrasted eukaryotic communities whose structure appeared to be at least partially correlated with sediment mineralogy. The concentration of arsenic in the sediment was shown to be a significant factor driving the eukaryotic community structure along this continuum.

Arsenic release and attenuation in low organic carbon aquifer sediments from West Bengal

High arsenic concentrations in groundwater are causing a humanitarian disaster in Southeast Asia. It is generally accepted that microbial activities play a critical role in the mobilization of arsenic from the sediments, with metal-reducing bacteria stimulated by organic carbon implicated. However, the detailed mechanisms underpinning these processes remain poorly understood. Of particular importance is the nature of the organic carbon driving the reduction of sorbed As(V) to the more mobile As(III), and the interplay between iron and sulphide minerals that can potentially immobilize both oxidation states of arsenic. Using a multidisciplinary approach, we identified the critical factors leading to arsenic release from West Bengal sediments. The results show that a cascade of redox processes was supported in the absence of high loadings of labile organic matter. Arsenic release was associated with As(V) and Fe(III) reduction, while the removal of arsenic was concomitant with sulphate reduction. The microbial populations potentially catalysing arsenic and sulphate reduction were identified by targeting the genes arrA and dsrB, and the total bacterial and archaeal communities by 16S rRNA gene analysis. Results suggest that very low concentrations of organic matter are able to support microbial arsenic mobilization via metal reduction, and subsequent arsenic mitigation through sulphate reduction. It may therefore be possible to enhance sulphate reduction through subtle manipulations to the carbon loading in such aquifers, to minimize the concentrations of arsenic in groundwaters.

New insight into solvent-related end-stage renal disease: occupations, products and types of solvents at risk

OBJECTIVES

It has been shown that all-solvent exposure is associated with the progression of primary glomerulonephritis to end-stage renal disease (ESRD), but little is known about the type of solvents that are high risk. The aim of this study was to investigate the role of solvents by occupation, product and type.

METHODS

Using a retrospective cohort design, the authors studied 269 patients with non-end-stage and biopsy-proven primary glomerulonephritis diagnosed between 1994 and 2001 in Paris and its suburbs. Two industrial hygienists evaluated patients' exposures from lifetime occupational histories collected by interview from 2002-4, and using a list of the 30 most common solvents. The studied outcome was ESRD, defined as glomerular filtration rate <15 ml/mn/1.73 m(2) or dialysis. It was recorded during a mean follow-up of five years. Cox models were used to estimate adjusted hazard ratios (HR) of ESRD related to exposures.

RESULTS

Eighteen per cent of the patients had ever been exposed to solvents. Those with the highest risk of progression to ESRD were exposed machinery fitters and machine assemblers (HR 4.7, 95% CI 1.2 to 17.4) and plumbers/welders (HR 4.2, 95% CI 1.3 to 13.6), as compared to never exposed patients, as well as those who ever handled printing inks and petroleum products (HR 12.6 (95% CI 1.7 to 94.9) and 3.2 (95% CI 1.4 to 7.2), respectively). Among solvents, the highest risks were found for: toluene/xylene (HR 5.1, 95% CI 1.8 to 14.8), gasoline, fuel and gas-oil (HR 8.6, 95% CI 2.7 to 27.4), and ketones (HR 13.3, 95% CI 1.4 to 123.5).

CONCLUSION

This study highlights the potential nephrotoxicity of several solvents. Intervention to promote screening for proteinuria in exposed workers may prevent the progression of glomerulonephritis to ESRD.

Respiratory symptoms and bronchial responsiveness among cleaning and disinfecting workers in the food industry

OBJECTIVES

To measure the levels of exposure to nitrogen trichloride (NCl3) and aldehydes among cleaning and disinfecting workers in the atmosphere of food industry plants during cleaning and disinfecting operations, and to examine how they relate to irritant and chronic respiratory symptoms-which are indices of pulmonary function-and bronchial hyperresponsiveness (BHR) to methacholine.

METHODS

175 exposed workers (M = 149; F = 26) recruited from 17 enterprises of the food industry (8 cattle, pig, and ovine slaughterhouses, 8 fowl slaughterhouses, and 1 catering firm) and 70 non-exposed workers (M = 52; F = 18) were examined. Concentration levels of NCl3 and aldhehydes were measured by personal sampling. Symptoms were assessed by means of a questionnaire and the methacholine bronchial challenge (MBC) test using an abbreviated method. Subjects were labelled MBC+ if forced expiratory volume in one second (FEV1) fell by 20% or more. The linear dose-response slope (DRS) was calculated as the percentage fall in FEV1 at last dose divided by the total dose administered.

RESULTS

277 air samples were taken in the 17 food industry plants. For a given plant and in a given workshop, the actual concentrations of chloramines, aldehydes, and quaternary ammonium compounds were measured with personal samplers during the different steps of the procedures. For each cleaner, a total exposure index Sigma was calculated. A statistically significant concentration-response relationship was found between eye, nasal, and throat symptoms of irritation--but not chronic respiratory symptoms--and exposure levels or exposure duration. No relation was found between BHR and exposure.

CONCLUSIONS

These data show that cleaning and disinfecting workers in the food industry are at risk of developing eye, nasal, and throat irritation symptoms. Although NCl3 exposure does not seem to carry a risk of developing permanent BHR, the possibility of transient BHR cannot be ruled out entirely.

Simultaneous sampling of peroxyacetic acid and hydrogen peroxide in workplace atmospheres

The use of peroxyacetic acid (PAA) in the disinfection processes in the food industry or for medical purposes is increasing. As it is the product of the reaction of acetic acid (AA) and hydrogen peroxide (HP) and coexists with them, and given the fact that the chemical properties of these two substances are not very different from PAA, the sampling and analysis of this substance in working atmospheres is difficult. A specific sampling device was developed. It is composed of: (i) a cassette with quartz fibre filters impregnated with titanium oxysulfate hydrate for the sampling of HP followed by; (ii) a tube filled with silica gel soaked with methyl p-tolylsulfoxide for the sampling of PAA. The analysis of this silica gel was performed by liquid chromatography with UV detection of the methyl p-sulfone generated by the sampling of PAA. The conservation of the sampling media (before and after sampling) and its efficiency were also checked. From the results of sampling campaigns performed in various workplaces, the relative contributions of PAA, AA and HP to an exposure index, taking into account the atmospheric concentrations and the threshold limit values, were established. This calculation shows that the simultaneous determination of PAA and HP, which the method presented in this paper allows, provides a fairly good estimation of the exposure.

Determination of short-term exposure with a direct reading photoionization detector

The use of a direct reading photoionization detector (PID) to determine short-term solvent exposures is described in the present paper. To assess the relevance of such a total exposure evaluation it was necessary to compare it with the real concentration of pollutants. This comparison was made by measuring in parallel with the PID determination the concentration of each pollutant using a standard technique, i.e. sampling on charcoal tubes and subsequent analysis by gas chromatography. Laboratory tests showed that the linearity of the answer of the PID is good for many compounds and for a mixture of these compounds. Similar tests were carried out for painters in workplaces with the same good correlations (determination coefficient r2 close to 1) between the PID response and the real concentration of the pollutants measured on the sampling tubes. The use of PID also allowed determination of the exposure profile of the workers and comparison of the short-term exposure to the corresponding limit values. Many cases of the short-term limit values being exceeded were revealed by use of the PID, although very few cases of the long-term limit values have been found by the usual sampling (charcoal tube) and analytical (gas chromatography) methods.

Generation of controlled atmospheres for the determination of the irritant potency of peroxyacetic acid

Given the physical properties of peroxyacetic acid, which decomposes into acetic acid and hydrogen peroxide, the generation and analysis of controlled atmospheres used to test the irritant potency of this peracid in mice require specific developments. The sampling and analytical method was based on the simultaneous sampling on a titanyl sulphate-impregnated silica gel tube (allowing the determination of total peroxides, peroxyacetic acid and hydrogen peroxide) and in an impinger containing a methyl-p-tolyl sulphide solution (of which the analysis yields the concentration of total acids, peroxyacetic acid and acetic acid, and peroxyacetic alone). From these results the concentrations of the different products can be inferred without interference. A special device composed of inert materials was designed for the generation of the controlled atmosphere. Buffering the peroxyacetic solution at pH 7 with a phosphate buffer allowed the generation of peroxyacetic acid atmospheres with negligible concentrations of acetic acid and hydrogen peroxide.

Regulation of central corticosteroid receptors following short-term activation of serotonin transmission by 5-hydroxy-L-tryptophan or fluoxetine

Alterations of the hypothalamic-pituitary-adrenal (HPA) axis function characterized by a decreased negative feedback capacity are often associated with affective disorders and are corrected by treatment with antidepressant drugs. To gain a better understanding of the effects of the antidepressant drug fluoxetine, a specific serotonin (5-HT) reuptake inhibitor, on central corticosteroid receptors, the effects of short-term activation of serotonin transmission on central corticosteroid receptor expression were analysed in adrenalectomized (ADX) rats either supplemented or not with corticosterone. Serotonin transmission was stimulated either by a single injection of the 5-HT precursor, 5-hydroxy-L-tryptophan (5-HTP), or by a 2-day treatment with fluoxetine. In ADX rats, administration of 5-HTP decreased hippocampal mineralocorticoid (MR) and glucocorticoid (GR) receptor numbers 24 h later, while their respective mRNAs were unchanged and these effects of 5-HTP were mediated by 5-HT2 receptors. In the hypothalamus, GR mRNAs and binding sites decreased 3 h and 24 h after 5-HTP, respectively. By contrast, fluoxetine treatment increased hippocampal MR and GR mRNAs and MR binding sites while GR number remained unchanged. In ADX rats supplemented with corticosterone, 5-HTP and fluoxetine treatment had the same effects on corticosteroid receptors compared to those observed in non supplemented ADX rats: 5-HTP decreased hippocampal MR and GR and hypothalamic GR while fluoxetine treatment increased hippocampal MR. These results show that short-term stimulation of 5-HT transmission by 5-HTP decreases hippocampal and hypothalamic corticosteroid receptor numbers through a corticosterone-independent mechanism. It is hypothesized that the delayed maximal increase in extracellular 5-HT contents after fluoxetine treatment, due to negative feedback regulations induced by the activation of 5-HT1A and 5-HT1B autoreceptors, is not the primary cause for the delayed normalization of corticosteroid receptor numbers that regulates the HPA axis functioning.

Delayed adjuvant tamoxifen: ten-year results of a collaborative randomized controlled trial in early breast cancer (TAM-02 trial)

AIM

Immediate adjuvant tamoxifen reduces disease recurrence and improves survival in patients with early breast cancer. However, is it too late to administer tamoxifen to patients who have already undergone treatment, but were unable to benefit from this adjuvant therapy? The French National Cancer Centers (FNCLCC) have investigated the efficacy of delayed tamoxifen administration in a randomized controlled trial.

PATIENTS AND METHODS

From September 1986 to October 1989, women with primary breast cancer, who had undergone surgery, radiotherapy, and/or received adjuvant chemotherapy but not hormone therapy more than two years earlier, were randomized to receive either 30 mg/day tamoxifen or no treatment. The 10-year disease-free and overall survival rates of the two groups of patients and of various subgroups were determined according to the Kaplan-Meyer method and compared by the log-rank test.

RESULTS

This intention-to-treat analysis comprised 250 Introduction women in the tamoxifen group and 244 in the control group. Patient characteristics (age, T stage, number of positive nodes, receptor status, and interval since tumor treatment) were comparable in both groups. Delayed adjuvant tamoxifen significantly improved overall survival only in node-positive patients and in patients with estrogen receptor-positive (ER+) or progesterone receptor-positive (PR+) tumors. Disease-free survival, however, was significantly improved in the global population and in several patient subgroups (node-positive, ER+, PR+). Patients in whom the interval between primary treatment and delayed adjuvant tamoxifen was greater than five years also had significantly improved disease-free survival.

CONCLUSIONS

Overall and disease-free survival results indicate that delayed adjuvant tamoxifen administration (30 mg/day) is justified in women with early breast cancer, even if this treatment is initiated two or more years after primary treatment.

Central 5-HT(1) and 5-HT(2) binding sites in transgenic mice with reduced glucocorticoid receptor number

Transgenic mice bearing a transgene coding for a glucocorticoid receptor antisense mRNA, which partially blocks glucocorticoid receptor expression, were used in order to clarify the role of glucocorticoid receptors in the regulation of 5-HT(1A), 5-HT(1nonA) and 5-HT(2) binding sites labelled by quantitative autoradiography in the frontal and prefrontal cortex, striatum, hypothalamus, amygdala and raphe nuclei. We found that 1 nM [3H]8-hydroxy-2-[di-N-propylamino]tetralin ([3H]8-OH-DPAT) binding to 5-HT(1A) sites was decreased in strata oriens (-15.1+/-3.5%) and radiatum-lacunosum-moleculare (-13.3+/-4.3%) of the hippocampal CA(3) area, and 2 nM [3H]5-hydroxytryptamine binding to 5-HT(1nonA) sites in the presence of 100 nM 8-OH-DPAT and mesulergine was decreased in the dorsal subiculum (-17.8+/-6.9%). By contrast, 5-HT(2) sites labelled by 0.5 nM of (+/-)-1-(2, 5-dimethoxy-4-[125I]iodophenyl)-2-aminopropane was increased in the dorsal subiculum (+35.2+/-11.5%) and CA(2) area (+29.2+/-11.3%). The observed differences in binding to 5-HT(1) and 5-HT(2) sites were all located in areas of the hippocampus that contain both gluco- and mineralo-corticoid receptors, and no difference was observed in anatomical structures which contain only glucocorticoid receptors. Therefore, it seems that the important factor for the regulation of these 5-HT receptors is the interaction between gluco- and mineralo-corticoid receptors rather than the absolute density of glucocorticoid receptors. These results suggest that some of the alterations of the serotonergic neurotransmission observed in depressed patients might be secondary to an altered glucocorticoid receptor function.

The effects of serotonin on glucocorticoid receptor binding in rat raphe nuclei and hippocampal cells in culture

The raphe-hippocampal serotonin (5-HT) system is involved in the regulation of the hypothalamus-pituitary-adrenal axis. The purpose of this study was to determine and compare the roles of 5-HT in the regulation of glucocorticoid receptor (GR) binding in the raphe nuclei and in the hippocampus. The effects of 5-HT, 5-HT agonists, and the 5-HT reuptake inhibitor citalopram on GR binding sites were studied in primary cultures of the fetal raphe nuclei and the hippocampus. Exposure of hippocampal cells to 5-HT, (+/-)-2,5-dimethoxy-4-iodoamphetamine (DOI; a 5-HT2 agonist), or citalopram resulted in an increase in number of GR binding sites. The effect of DOI was blocked by ketanserin (a 5-HT2 antagonist). Specific and saturable GR binding was found in raphe cells. Exposure of raphe cells to 5-HT, (+/-)-8 hydroxy-2-(di-n-propylamino)tetralin (8-OH-DPAT; a 5-HT1A agonist), or citalopram induced a significant decrease in number of GR binding sites. The effect of 8-OH-DPAT was reversed by WAY 100135 [N-tert-butyl-3-[1-[1-(2-methoxy)phenyl]piperazinyl]-1-phenylpropiona mide; a 5-HT1A antagonist]. These results show that the regulation of GRs during fetal life is structure-dependent and involves different 5-HT receptor subtypes. Moreover, the regulation of hippocampal GRs by citalopram suggests an action of antidepressants independent of their effects on monoamines.

Regional serotonin metabolism under basal and restraint stress conditions in the brain of transgenic mice with impaired glucocorticoid receptor function

Transgenic (TG) mice deficient in glucocorticoid receptors (GR) were used in order to study the effects of a reduced GR function on adrenocorticotropin hormone and corticosterone plasma levels and on serotonin metabolism in different brain areas under basal resting conditions, after a 30-min restraint stress and 60 min after the end of the restraint stress. There was no difference in basal or stress-induced levels of either adrenocorticotropin hormone or corticosterone in control and TG mice, but the return of adrenocorticotropin hormone to basal values after the end of the stress was delayed in TG mice. Under basal conditions, the ratio 5-hydroxyindoleacetic acid/5-hydroxytryptamine was decreased only in the hippocampus of TG mice compared to controls. In the brain stem, the ratio 5-hydroxyindoleacetic acid/5-hydroxytryptamine increased compared to basal values after a 30-min restraint stress and values were still high 60 min after the end of the restraint stress in both control and TG mice. In the hippocampus, the ratio 5-hydroxyindoleacetic acid/5-hydroxytryptamine increased at the end of the stress and returned to basal levels 60 min later in control mice, whereas there was no change at the end of the stress but an increase 60 min later in TG mice. Finally there was no change in serotonin metabolism in the cortex, striatum or hypothalamus in either group or situation. Our results support the hypothesis of a tonic activation of serotonin turnover by corticosterone through GR in the mouse hippocampus. Moreover, stress-induced stimulation of serotonin metabolism in the brain stem and hippocampus appears to be delayed in TG mice compared to control mice. These results are particularly relevant for mood disorders such as depression where alterations of serotoninergic transmission might be secondary to an impairment of GR functions.

Identification and role of serotonin 5-HT1A and 5-HT1B receptors in primary cultures of rat embryonic rostral raphe nucleus neurons

Autoregulatory mechanisms affecting serotonin [5-hydroxytryptamine (5-HT)] release and synthesis during the early period of development were investigated in dissociated cell cultures raised from embryonic rostral rat rhombencephalon. The presence of 5-HT1A and 5-HT1B receptors in serotoninergic neurons was assessed using binding assays. The involvement of 5-HT1A and 5-HT1B receptors in the control of the synthesis and release of [3H]5-HT was studied using biochemical approaches with several serotoninergic receptor ligands. A mean decrease of 30% in [3H]5-HT synthesis and release was observed in the presence of 5-HT (10(-8) M), the 5-HT1A agonist 8-hydroxy-2-(di-n-propylamino)tetralin (8-OH-DPAT), the 5HT1B/1A agonist 5-methoxy-3-(1,2,5,6-tetrahydro-4-pyridinyl)-1H-indole (RU 24969), the 5-HT1B agonist 3-(1,2,5,6-tetrahydropyrid-4-yl)pyrrolo[3,2-b]pyrid-5-one (CP-93,129), and the 5-HT(1D/1B) agonist sumatriptan. Inhibition of 5-HT synthesis and release induced by 8-OH-DPAT was blocked by chiral N-tert-butyl-3-[1-[1-(2-methoxy)phenyl]piperazinyl]-1-phenylpropionam ide dihydrochloride quaternary-hydrate (WAY 100135) (10(7) M) or methyl 4-[4-[4-(1,1,3-trioxo-2H-1,2-benzoisothiazol-2-yl)butyl]-1-p iperazinyl]-1Hindole-2-carboxylate (SDZ 216-525) (10(-7)M), and that of CP-93,129 was blocked by methiothepin (10(-7) M). Paradoxically, extracellular levels of [3H]5-HT increased in the presence of 8-OH-DPAT and RU 24969 at 10(-6) M. 5-HT uptake experiments showed that these two agonists interacted with the 5-HT transporter. 5-HT1 binding sites (620 fmol/mg of protein) and 5-HT1A (482 fmol/mg of protein) and 5-HT1B (127 fmol/mg of protein) receptors were detected in 12-day in vitro cell cultures. Experiments carried out with tetrodotoxin suggested that 5-HT1A receptors are located on nerve cell bodies, whereas 5-HT1B receptors are located on the nerve terminals. We concluded that autoregulatory mechanisms involving 5-HT1A and 5-HT1B autoreceptors are functionally mature in cells from rostral raphe nuclei during the early period of development.

Respiratory symptoms and bronchial responsiveness in lifeguards exposed to nitrogen trichloride in indoor swimming pools

OBJECTIVES

To measure the levels of exposure to nitrogen trichloride (NCl3) in the atmosphere of indoor swimming pools and to examine how they relate to irritant and chronic respiratory symptoms, indices of pulmonary function, and bronchial hyperresponsiveness to methacholine in lifeguards working in the pools.

METHOD

334 lifeguards (256 men; 78 women) recruited from 46 public swimming pools (n = 228) and 17 leisure centre swimming pools (n = 106) were examined. Concentrations of NCl3 were measured with area samplers. Symptoms were assessed by questionnaire and methacholine bronchial challenge (MBC) test by an abbreviated method. Subjects were labelled MBC+ if forced expiratory volume in one second (FEV1) fell by > or = 20%. The linear dose-response slope was calculated as the percentage fall in FEV1 at the last dose divided by the total dose given.

RESULTS

1262 samples were taken in the 63 pools. Mean NCl3 concentrations were greater in leisure than in public pools. A significant concentration-response relation was found between irritant eye, nasal, and throat symptoms-but not chronic respiratory symptoms-and exposure concentrations. Among women, the prevalence of MBC+ was twice as great as in men. Overall, no relation was found between bronchial hyperresponsiveness and exposure.

CONCLUSIONS

The data show that lifeguards exposed to NCl3 in indoor swimming pools are at risk of developing irritant eye, nasal, and throat symptoms. Exposure to NCl3 does not seem to carry the risk of developing permanent bronchial hyperresponsiveness, but this association might have been influenced by self selection. The possibility that subjects exposed to NCl3 are at risk of developing transient bronchial hyperresponsiveness cannot be confidently ruled out.

Field study of subjective assessment of negative pressure half-masks. Influence of the work conditions on comfort and efficiency

The aim of this study was to assess the effects of work conditions on the acceptability and efficiency of respiratory protective devices (RPD). The subjective evaluation of comfort, protection, respiratory and visual constraint, and the acceptable duration of wear of six RPDs against dust was achieved by 30 workers during their actual work. Metabolic rate was evaluated for each worker, and dry and wet air temperatures measured in the work area. RPDs objective protection factor was measured during each of the 180 test periods. In the conditions of this study, the acceptable duration of wear was about 1 h. This duration and the comfort parameters were reduced when the air temperature increased. The younger workers and/or smokers were less sensitive to mask discomfort. Objective protection factors of the RPDs are reduced under warmer conditions, and when the metabolic rate is low. Finally, the results of this study also show the poor capacity of standardized leakage tests to assess the objective respiratory protection of workers in the field. Some hypotheses which can explain this fact are discussed.

Serotonin directly stimulates luteinizing hormone-releasing hormone release from GT1 cells via 5-HT7 receptors

Luteinizing hormone-releasing hormone (LHRH release, which serves as the primary drive to the hypothalamic-pituitary gonadal axis, is controlled by many neuromediators. Serotonin has been implicated in this regulation. However, it is unclear whether the central effect of serotonin on LHRH secretion is exerted directly on LHRH neurosecretory neurons or indirectly via multisynaptic pathways. The present studies were undertaken in order to examine whether LHRH secretion from immortalized LHRH cell lines is directly regulated by serotonin and, if so, to identify the receptor subtype involved. 8-hydroxy-2-(di-n-propylamino)tetralin (8-OH-DPAT), a 5-HT1A/7 receptor agonist, stimulated LHRH release from GT1-1 cells. This effect was blocked by ritanserin, a 5-HT2/7 receptor antagonist, but not by SDZ-216-525, a 5-HT1A antagonist. Basal LHRH release was not affected by the 5-HT2 agonist DOI. Reverse transcription and polymerase chain reaction technique (RT-PCR) was used in order to identify 5-HT1A and 5-HT7 receptor mRNA in immortalized LHRH cell lines. GT1-1 cells express mRNA for the 5-HT7, but not the 5-HT1A receptor subtypes. These results demonstrate a direct stimulatory effect of serotonin on LHRH release via 5-HT7 receptor.

[Tamoxifen adjuvant delays early breast cancer. Results of a cooperative randomized trial]

Adjuvant tamoxifen (TAM) has been proved to reduce recurrence and mortality in early breast cancer, nevertheless many patients did not receive TAM as adjuvant therapy after local treatment. In order to study the efficacy of delayed TAM therapy in patients who were not given immediate adjuvant hormonal treatment, a multicenter randomized trial has been conducted by the French National Cancer Centers (FNCLCC). According to eligibility criterias all women with breast cancer who received curative local treatment at least 2 years before (surgery +/- radiotherapy) with or without adjuvant chemotherapy but no hormonal treatment could have been included. Between September 1986 and October 1989, 494 women were randomized to receive either TAM 30 mg/day for 5 years or no treatment. Patients' characteristics such as age, tumoral stage, number of positive nodes, receptors status and time from local treatment were equally distributed in the 2 groups. An improvement in the disease free survival in the TAM treated patients can be observed with a significative difference (p = 0.05), nevertheless the overall survival is not improved in the TAM group. In the same way, in nodes positive patients although no significative improvement in the overall survival can be observed, a significative improvement in the disease free survival (p = 0.05) can be noted. In estradiol receptors positive patients tamoxifen gives a significative reduction in the odds of death (p = 0.04) and recurrence (p = 0.03). The disease free improvement seems to be limited to 50 and more years old patients. The first results of this trial lead to prescribe tamoxifen to all postmenopausal women previously treated for an early breast cancer without adjuvant tamoxifen treatment.

The modulatory role of estrogens on corticotropin-releasing factor gene expression in the hypothalamic paraventricular nucleus of ovariectomized rats: role of the adrenal gland

In vitro, estrogens stimulate corticotropin-releasing factor (CRF) gene transcription. In ovariectomized (OVX) rats, estrogens have a negative effect on CRF mRNA levels in the hypothalamic paraventricular nucleus. This suggests that the stimulatory influence of estrogens found in vitro may be masked in vivo by an inhibitory effect mediated through neural and/or humoral factors. Glucocorticoids may be involved in this phenomenon since estrogens increase circulating corticosterone levels in OVX rats. We studied the effect of 7-day 17 beta-estradiol (E2) treatment on CRF gene expression in the paraventricular nucleus of 2-week OVX mature rats after sham operation or adrenalectomy (ADX) with or without corticosterone replacement. In sham ADX animals, E2 administration increased plasma corticosterone concentrations, did not change the binding capacity or the affinity of circulating corticosteroid binding globulin, and decreased hypothalamic CRF gene expression. Following ADX, CRF mRNA levels increased and were normalized by corticosterone treatment. Estrogens induced a significant build up in CRF mRNA concentrations in both ADX or ADX corticosterone-replaced animals. Our data demonstrate that the positive effect of estrogens on CRF gene expression found in vitro or in vivo after ADX is antagonized, in vivo when the adrenal glands are intact, by a negative influence. They strongly suggest that the increased circulating corticosterone levels induced by E2 administration mediate the inhibitory effect of estrogens on CRF mRNA levels. These observations may explain the gender related differences in the basal and stress-induced hypothalamo-pituitary-adrenal activity.

8-OH-DPAT regulates the amplitude and the phase of LH surge in ovariectomized steroid-primed rats

Precise interactions between ovarian steroids and neurotransmitters are required for the secretion of phasic LH surge. Previous data suggested the existence of an interactive stimulatory effect of progesterone (P) and serotonin (5-HT) on LH release. In the present work the effects of 8-OH-DPAT, a selective 5-HT(1A) agonist, on phasic LH secretion were tested in ovariectomized rats implanted for 6 days with a pellet of 17 β estradiol (OVX-E(2)) and in OVX-E(2) treated with progesterone (OVX-E(2)-P). Intraperitoneal injection of 8-OH-DPAT at 11.00 h in the morning of the expected LH surge had no effect on circadian plasma levels of LH in OVX-E(2) rats, whereas it induced a phase advance and an increase in LH surge in OVX-E(2)-P rats. Administration of the antiprogestin RU 38486 in OVX-E(2)-P rat, totally abolished the combined effects of P and 8-OH-DPAT on phasic LH release. SDZ 216-525, a specific 5-HT(1A) antagonist administered 60 min before 8-OH-DPAT, inhibited the stimulatory effect of the 5-HT(1A) agonist on the amplitude of LH surge. The present data suggest that progesterone is required for the regulation of phasic LH release by 5-HT(1A) agonists and that under this hormonal condition the activation of 5-HT(1A) receptors induces a phase advance and an increase in LH surge.

Estrogens decrease expression of the corticotropin-releasing factor gene in the hypothalamic paraventricular nucleus and of the proopiomelanocortin gene in the anterior pituitary of ovariectomized rats

It is known that estrogens modulate the hypothalamopituitary-adrenal (HPA) axis both under resting conditions and during exposure to stress. Nevertheless, the site of action of estrogens is not still fully elucidated. We sought to determine if estrogens could act on the major hypothalamic ACTH secretagogue: corticotropin-releasing factor (CRF). Mature rats were ovariectomized (OVX) and 2 weeks later implanted with silastic capsules containing 17β-estradiol (E(2)). Animals were sacrificed 7 days later. CRF mRNA in the hypothalamic paraventricular nucleus (PVN) and proopiomelanocortin (POMC) mRNA in the anterior pituitary were measured byin situ hybridization. CRF content in the median eminence was measured by semiquantitative immunocytochemistry. E(2) treatment induced a significant decrease of CRF mRNA levels in the PVN (3.70±0.14vs 4.79±0.15 copies of probe×10(-3)/μm(3) of tissue in OVX rats,P<0.05), an accumulation of immunoreactive CRF in the zona externa of the median eminence (207±36vs 100±15% in OVX rats,P<0.05), and a decrease of POMC mRNA levels in the anterior pituitary (4.6±0.6vs 6.9±0.6 copies of probe ×10(-2)/μm(3) of tissue in OVX rats,P<0.05). These results demonstrate that estrogens have a negative effect on CRF gene expression and secretion and on POMC gene expression. Whether estrogens modulate directly the CRF-synthesizing cells or act through an increase of the glucocorticoid negative feedback remains to be determined.

Stimulatory effects of 5HT1A receptor agonists on luteinizing hormone-releasing hormone release from cultured fetal rat hypothalamic cells: interactions with progesterone

Previous works have suggested an interactive stimulatory effect of progesterone (P) and serotonin (5-HT) on luteinizing hormone release. The purpose of the present study was to determine whether 5-HT via 5-HT1A receptors interacts with P in the process of luteinizing hormone-releasing hormone (LHRH) release. Using fetal hypothalamic neurons in primary cell cultures the first goal of this study was to determine the effects of 5-HT1A receptor agonists on LHRH secretion. 8-Hydroxy-2 (di-n-propylamino) tetralin (8-OH-DPAT) or ipsapirone (10(-5) M) significantly stimulated LHRH release. Pharmacological studies have allowed to rule out the possible involvement of alpha 2- or beta-adrenoreceptors, or 5-HT uptake sites, in the stimulatory effect of 8-OH-DPAT on LHRH release, thus demonstrating the specific involvement of 5-HT1A receptors in the stimulation of LHRH release. The second goal was to test the ability of P to stimulate LHRH release from fetal hypothalamic neurons. P (10(-6) M) applied for 30 or 120 min significantly stimulated LHRH secretion. The maintenance of the stimulation of LHRH release by P after a cycloheximide treatment or by an impermeable analog of P, P-3-BSA, has suggested a nongenomic effect of P on LHRH release. The effects of a pretreatment of cells by P on 8-OH-DPAT-induced LHRH release were tested. While 10(-7) M P alone did not stimulate LHRH release, this concentration of steroid potentiated the LHRH response to 10(-5) M 8-OH-DPAT. These findings led to the conclusion that P acting at the level of the plasma membrane potentiates the stimulatory effect of 5-HT1A receptor agonists on LHRH release.

Impairment of serotoninergic transmission is followed by adaptive changes in 5HT1B binding sites in the rat suprachiasmatic nucleus

Serotonin1B (5-HT1B) receptor binding in the suprachiasmatic nucleus (SCN) following impairment of serotoninergic transmission was studied by quantitative autoradiography. Serotonin (5-HT) denervation with 5,7-dihydroxytryptamine (5,7-DHT) caused a significant increase in the density of 5-HT1B receptors in both the ventral (62%) and dorsal (53%) parts of the SCN as early as 3 days after axotomy. The magnitude of this increase did not differ 3, 15 or 21 days post-lesion. An up-regulation of 5-HT1B receptors with similar magnitude was obtained in the two parts of the SCN after inhibition of 5-HT synthesis by chronic parachlorophenylalanine treatment. In this case, up-regulation was shown to be reversible after restoration of 5-HT synthesis with L-5-hydroxytryptophan. These results indicate that 5-HT1B receptor density in the SCN was inversely correlated with 5-HT levels. These plastic properties exhibited by 5-HT1B receptors in the SCN are discussed in relation to the mode of 5-HT transmission and possible localization of the receptors onto the main chemically defined cell populations of the nucleus.

N-methyl-D-aspartic acid/glycine interactions on the control of 5-hydroxytryptamine release in raphe primary cultures

Glutamic acid and glycine were quantified in cells and medium of cultured rostral rhombencephalic neurons derived from fetal rats. In the presence of 1 mM Mg2+, NMDA (50 microM) significantly stimulated (by 69%) release of newly synthesized 5-[3H]hydroxytryptamine ([3H]5-HT). D-2-Amino-5-phosphonopentanoate (AP-5; 50 microM) blocked the stimulatory effect of NMDA. AP-5 by itself inhibited [3H]5-HT release (by 25%), suggesting a tonic control of 5-HT by glutamate. In the absence of Mg2+, basal [3H]5-HT release was 60% higher as compared with release with Mg2+. AP-5 blocked the increased [3H]5-HT release observed without Mg2+, suggesting that this effect was due to the stimulation of NMDA receptors by endogenous glutamate. Glycine (100 microM) inhibited [3H]5-HT release in the absence of Mg2+. Strychnine (50 microM) blocked the inhibitory effect of glycine, indicating an action through strychnine-sensitive inhibitory glycine receptors. The [3H]5-HT release stimulated by NMDA was unaffected by glycine. In contrast, when tested in the presence of strychnine, glycine increased NMDA-evoked [3H]5-HT release (by 22%), and this effect was prevented by a selective antagonist of the NMDA-associated glycine receptor, 7-chlorokynurenate (100 microM). 7-Chlorokynurenate by itself induced a drastic decrease in [3H]5-HT release, indicating that under basal conditions these sites were stimulated by endogenous glycine. These results indicate that NMDA stimulated [3H]5-HT release in both the presence or absence of Mg2+. Use of selective antagonists allowed differentiation of a strychnine-sensitive glycine response (inhibition of [3H]5-HT release) from a 7-chlorokynurenate-sensitive response (potentiation of NMDA-evoked [3H]5-HT release).

Increase of central 5-HT1B binding sites following 5,7-dihydroxytryptamine axotomy in the adult rat

The effects of selective axotomy of serotoninergic neurons produced by an intracerebroventricular injection of 5,7-dihydroxytryptamine (200 micrograms free base) on 5-HT1B binding sites labeled with S-CM-G-[125I]TNH2 were investigated by quantitative autoradiography in the rat brain. Results show, 21 days after surgery, an upregulation of 5-HT1B receptors in the entorhinal cortex and the dorsomedial and suprachiasmatic nuclei of the hypothalamus. The cellular localization of those 5-HT1B receptors exhibiting post-lesion plastic properties is discussed.

Postmenopausal patients with node-positive resectable breast cancer. Tamoxifen vs FEC 50 (6 cycles) vs FEC 50 (6 cycles) plus tamoxifen vs control--preliminary results of a 4-arm randomised trial. The French Adjuvant Study Group

In 1986 the true benefit of adjuvant medical treatment in postmenopausal patients with pathological node-positive breast adenocarcinoma was still controversial. The French Adjuvant Study Group (FASG) initiated a randomised trial to elucidate the respective roles of adjuvant chemo-and/or hormonotherapy in this group of patients. Of the 776 patients who have been included between 1986 and 1990, 741 were fully eligible for evaluation. Inclusion criteria were postmenopausal patients aged between 50 and 70 years with adenocarcinoma of the breast, positive pathological nodes and no distant metastasis. Patients were randomised to 1 of 4 treatment arms: Group A (n = 192) received tamoxifen 30 mg/day orally for 3 years; Group B (n = 183) received FEC 50 (fluorouracil 500 mg/m2, epirubicin 50 mg/m2 plus cyclophosphamide 500 mg/m2) for 6 cycles; Group C (n = 182) received tamoxifen 30 mg/day orally for 3 years plus FEC 50 for 6 cycles; Group D (n = 184) received no medical adjuvant treatment. Surgery was either modified radical mastectomy (n = 363) or tumorectomy (n = 378), and postoperative irradiation was given to all patients. All major prognostic factors were well balanced between the 4 patient groups. Toxicity was evaluated in 348 patients in Groups B and C who received a total of 1983 chemotherapy cycles. Median epirubicin dose intensity (mg/m2/week) was 15.8 in Group B and 15.7 in Group C. Grade 3 to 4 neutropenia was observed in 4.7% of cycles for Group B and 3.7% for Group C. Grade 3 to 4 nausea/vomiting were seen in 18% of treatment cycles in Group B and 15% in Group C.(ABSTRACT TRUNCATED AT 250 WORDS)

Evidence for the presence of noradrenergic neurons and their inhibitory action on luteinizing hormone-releasing hormone release in cultured fetal rat hypothalamic cells

The control of LHRH release by catecholamine systems during fetal life (embryonic stages) was studied using hypothalamic neurons in primary cell cultures and an attempt was made to characterize the receptor type involved. Phenylephrine and clonidine, respectively alpha 1 an alpha 2 adrenoreceptor agonists, both inhibited LHRH release. These agonist inhibitory induced-effects were antagonized by the respective alpha 1 and alpha 2 adrenoreceptor antagonists (prazosin and rauwolscine). Both prazosin and rauwolscine applied alone induced a marked increase in LHRH release. Similarly, inhibition of catecholamine synthesis obtained by alpha-methyl-para-tyrosine (alpha-MT) led to a significant increase in LHRH release. The stimulatory effects induced by alpha 1 and alpha 2 adrenoreceptor antagonists or by alpha-MT on LHRH release suggest the presence of noradrenergic and/or adrenergic cells in fetal hypothalamic cultures. Therefore, catecholamine contents were measured in fetal hypothalamic cells in culture. Measurable amounts of norepinephrine and dopamine were found in cells, although epinephrine was undetectable. These results show: 1--noradrenergic cells are present in primary culture of fetal hypothalamic cells. 2--This intrinsic hypothalamic noradrenergic system exerts an inhibitory control on LHRH release at an early stage of development through alpha 1 and alpha 2 adrenoreceptors.

Prognostic value of total cathepsin D in breast tumors. A possible role in selection of chemoresistant patients

Evaluation of prognostic factors for breast cancers is important for therapeutic decisions both at the time of surgery and during postoperative surveillance. In 1979, H. Rochefort described an induced protein with a molecular weight of 52,000 Daltons identified as procathepsin D. Total cathepsin D (TCD) (52K + 48K + 34K), expressed in pmol/mg protein, can be measured by an immunoradiometric method commercialized by Cis-Biointernational. Total cathepsin D was assayed in 413 breast cancer tumors from patients who underwent surgery between January 1, 1978, and December 31, 1985. Using a cut-off of 35 pmol/mg protein, patients with an elevated level had a significantly poorer survival than those with a low level (p = 0.03). This difference was not found for node-negative patients but was very significant for node-positive patients (p less than 0.008). The survival of node-positive patients with a low total cathepsin level was not statistically different from that of node-negative patients. Analysis of the N+ subgroup of patients who did not receive adjuvant chemotherapy revealed that TCD no longer had any prognostic value, whereas it was still important for the N+ subgroup who received an adjuvant treatment. Cox multivariate analysis of prognostic value for survival placed total cathepsin D in third position, after nodal invasion and progesterone receptor status, for the entire population, and in first position before progesterone receptor status for the node-positive population. The association of a low cathepsin level and positive progesterone receptors characterized the subgroup of patients with the longest survival. TCD levels played the same role for prediction of the outcome of metastasis.(ABSTRACT TRUNCATED AT 250 WORDS)

Population-specific modulation of 5-HT expression in cultures of embryonic rat rhombencephalon

This study aimed at analyzing the regulation of in vitro serotonin expression by neurons taken from different regions of the embryonic rat rhombencephalon. We studied the influence of co-culture with alarplate tissue using immunocytochemical and biochemical methods. Computer-assisted densitometry was used to estimate the co-culture effects on the serotonin content of the cell bodies. The more dynamic aspects of serotonin expression, such as synthesis and release, were studied by measuring (3H)serotonin newly synthesized from (3H)tryptophan. The density of the immunostaining was significantly decreased in B1,B2 cells by co-culture with both caudal and rostral alar-plate tissue. For B4-B9 cells, only co-culture with rostral alar-plate tissue produced a significant decrease. The de novo synthesis of serotonin was significantly decreased in B1,B2 neurons co-cultured with caudal alar-plate tissue only. Once again, the B4-B9 cells proved to be less influenced by the experimental conditions, as co-culture with both types of alar-plate tissue produced no significant effect. We concluded that the in vitro expression of serotonin can be modulated by environmental factors, but the relative influence of these factors is very different in rostral versus caudal serotonin expressing cell populations.

Alternate day treatment and late effects: the concept of an effective dose per fraction

Although most institutions treat all fields each day, some radiotherapists continue to adopt an alternate day schedule. The resulting daily variations of the dose per fraction in laterally located targets have been analyzed using the linear-quadratic model. Patients with breast carcinoma treated with definitive radiotherapy in 1974-1975 with one field a day were studied. An effective dose per fraction was derived, with a value higher than the average dose per fraction received by the reference point. The greater the fluctuations between the doses per fraction on successive days, the higher the effective dose per fraction. The corresponding cell survival due to alternate treatment as compared to survival with daily treatment depends on the alpha/beta ratio. For a late effect with low alpha/beta ratio, an alternate treatment may lead to almost 10-fold increase in cell kill in these lateral targets such as those responsible for subcutaneous sclerosis as compared to daily treatment of all fields with the same total dose. Taking the average effective dose per fraction in our series, the increase in cell kill was 4-fold. Acute effects would suffer less damage due to alternate treatment because of a high alpha/beta ratio. Treatment on an alternate schedule should be restricted to palliative radiotherapy.

Regulation by estradiol of GABAA and GABAB binding sites in the diencephalon of the rat: an autoradiographic study

Using in vitro quantitative autoradiography we studied the in vivo effects of estradiol on GABAA and GABAB receptors in the rat brain. In all the areas studied (suprachiasmatic nucleus, medial preoptic area, striatum, frontal cortex), estradiol failed to significantly affect the GABAA receptor density. Chronic treatment with estradiol led however in the suprachiasmatic nucleus and the striatum to a decrease in the density of GABAB receptors. GABAB receptor regulation by estradiol was found to be area-specific within the hypothalamus since it was not observed in the medial preoptic area. The down regulation of GABAB receptors in the suprachiasmatic nucleus induced by estradiol treatment might thus explain the inhibitory effect of the steroid on the GABA control of serotonin metabolism we recently reported.

Factors affecting relapse in node-negative breast cancer. A multivariate analysis including the labeling index

Between 1975 and 1982, 167 patients with carcinoma of the breast without axillary lymph node metastases were studied. The thymidine labeling index (LI), representing the percentage of cells in the DNA synthesis phase, was measured in all these patients. High LI values were more frequently encountered in young patients (P = 0.05), in low estrogen receptor (ER) tumor content (P = 0.007) and in high grade tumors (P = 0.0002). The overall 8-year relapse-free survival (RFS) was 68%. Univariate analysis demonstrated that RFS was influenced by histological grading (P = 0.03), ER (P = 0.03), PR (P = 0.02) and LI (P = 0.01). Multivariate analysis using the Cox regression model selected the LI as the single significant prognostic factor with regard to RFS (P = 0.037). These results emphasize the important role of cell proliferation kinetics in defining node-negative breast cancer patients with a high risk of relapse.

Development and use of a computer system in a radiotherapy department: SISGRAD

SISGRAD, the interactive computer system of the Antoine-Lacassagne Cancer Center Radiotherapy Department, has been operational since January 1982. It completes the computerized dosimetry system installed several years earlier and is fully integrated with the institution's central network. SISGRAD is in charge of surveillance of the radiotherapy treatments given by the Center's three radiotherapy units (1400 patients per year); it is also used for administrative purposes in the Department and physically connects all of the Department's operating stations. SISGRAD consists of a series of microcomputers connected to a common mass memory; each microcomputer is used as an intelligent console. SISGRAD was developed to guarantee that the treatments comply with prescriptions, to supply extemporaneous dosimetric data, to improve administrative work, and to supply banks with data for statistical analysis and research. SISGRAD actively intervenes to guarantee treatment quality and helps to improve therapy-related security factors. The present text describes the results of clinical use over a 4-year period. The consequences of integration of the system within the Department are analyzed, with special emphasis being placed on SISGRAD's role in the prevention and detection of errors in treatment prescription and delivery.

The DNA labelling index: a prognostic factor in node-negative breast cancer

The DNA labelling index (LI), representing the fraction of S-phase cells, was studied in 76 patients operated on for breast cancer from 1975 to 1979. No patient had lymph node involvement following axillary dissection (N-), and no adjuvant medical treatment was given. Patients were classified in one of two groups according to the median LI. Patient distribution by age, tumour size, and receptor status was identical in both groups. A higher frequency of grade 3 tumours was noted in the group with an LI above the median value. The cell proliferation rate was an important discriminative factor for metastatic potential. The probability of survival at 8 years for patients with a high LI was significantly lower than that of patients with low LI (36% versus 100%; p less than 0.001). Relapse-free survival at 8 years was respectively 56% and 83% (p less than 0.02). At 2 years, these values were 75% and 100%, indicating the early occurrence of metastases. By contrast, the LI had no prognostic value concerning loco-regional disease recurrence or survival after the appearance of metastasis. No relationship was found in this study between survival and other prognostic factors, namely tumour size, histological grade, or hormone receptor level. The LI currently appears to be the best prognostic factor for N- breast cancer. High risk patients identified by this method could thus be offered adjuvant medical treatment.

CT measurement of lung density: the role of patient position and value for total body irradiation

To obtain more precise data on pulmonary doses in preparation for total body irradiation, the lung density of patients was systematically analyzed in treatment positions using data obtained by computed tomography (CT). With the patient supine, the lung density was not significantly different for the right and left lungs. In contrast, considerable differences were noted between the two lungs in lateral decubitus positions owing to variations in ventilation and perfusion. The relative electron density of lung was also found to decrease with age, dropping to pe = 0.160 at 71 years.

[Adriamycin in low weekly doses. Latest therapy of advanced cancer of the breast]

Thirty-four patients with heavily pretreated advanced breast cancer received adriamycin in weekly doses of 12 mg/m2. Twenty-two patients (18 assessable) had a performance status greater than or equal to 3 (WHO scale). There were 5 (28%) partial responses, 7 (39%) minimal responses, 3 cases (17%) with no change and 3 (17%) with progressive disease; the mean duration of response was superior to 9 months (range: 3-12 months). In the remaining 12 patients, who had resisted a previous multidrug regimen containing adriamycin, there were 3 (25%) partial responses, 2 (17%) minimal responses, 4 cases (33%) with no change and 3 (25%) with progressive disease; the mean duration of response was superior to 5 months (range: 3-11 months). More than 600 weekly injections were administered with only minor blood and digestive tract toxicities. No alopecia was recorded. The total cumulative dose of adriamycin was superior to 900 mg/m2 in 8 patients; none had clinically evident cardiac toxicity. Adriamycin extravasation with subsequent tissue necrosis occurred on 10 occasions due to the frequency of administration; this problem was solved by the systematic installation of central venous catheters.

Value of ultrasound in localizing the internal mammary vessels

The authors discuss the value of ultrasound in determining the depth of the internal mammary vessels und their distance from the medial line. Real-time imaging with a high frequency transducer and a pulsed Doppler system gave highly accurate results. Depending on the intercostal space, the depth of internal mammary vessels varies from 17 to 22 mm. The distance of the internal mammary vessels from the medial line is a function of the intercostal space and the body side, and varies from 25 to 33 mm. Results were found to vary as a function of patient height and weight; likewise, mastectomy was seen responsible for a modification of 2 mm in measurements. Precise localization of the internal mammary vessels allows optimization of radiotherapy, and this rapid examination should be performed just prior to the start of irradiation.

Conservative treatment (chemotherapy/radiotherapy) of locally advanced breast cancer

Once treated almost exclusively by radical surgery, locally advanced breast cancers (Stages III, IV; MO) were later treated solely by irradiation, but local results (cosmesis and recurrences) remained poor. Since 1977, we have used induction chemotherapy in an attempt to treat subclinical metastatic disease while allowing better quality mammary conservation in a greater number of patients. From 1977 to 1980, 25 patients (Stages III, IV; MO) were treated by a sequential association of chemotherapy (Adriamycin [doxorubicin], vincristine, cyclophosphamide, 5-fluorouracil; 3 cycles) followed by irradiation (45 Gy to the breast and nodal areas; 15-30 Gy mammary boost dose). Responses of 50% or more were observed in 86% of the breast lesions and in 80% of nodal lesions. This sequential treatment was always well tolerated. Local recurrences occurred in six patients (24%) who underwent mastectomy without any complications. The survival rate at 4 years is 55%.