Incidence of retinal detachment following clear-lens extraction in myopic patients. Retrospective analysis.

OBJECTIVE: A retrospective study was performed to establish the incidence of retinal detachment among 107 patients (165 eyes) with pathologic myopia who underwent clear-lens extraction. INTERVENTIONS: The techniques employed were intracapsular extraction (3.0%), aspiration (59.4%), and extracapsular extraction (37.6%); average follow-up was 31 months. RESULTS: Retinal detachment developed in 12 eyes (7.3%) an average (SD) of 30.7 +/- 26.6 months postoperatively; the mean age of these patients was 34 years. We found a clear association between postoperative YAG laser/surgical posterior capsulotomy and the incidence of retinal detachment (11% vs 5.5%) but no association between intraoperative rupture of the posterior capsule and the ultimate incidence of retinal detachment. The retina was reattached in nine cases (75%).

Guinea pig pulmonary response to sensitization by five preformed monoisocyanate-ovalbumin conjugates.

The ability of 5 dissimilar monoisocyanates conjugated to ovalbumin (OA) as a carrier protein to induce pulmonary hypersensitivity towards the hapten specific component was assessed by using a previously described method based on the determination of a respiratory index (RI) in the guinea pig. The test chemicals included the commercially available p-tolyl and hexyl monoisocyanates (TMI and HMI), with 4-isocyanoto-4'-diphenylmethane (IDM), 4-isocyanoato-4'-methyldiphenylmethane (IMDM) and 1-isocyanato-methyl-1,3,3-trimethylcyclohexane (IMTC) as synthetized monoisocyanates. Guinea pigs were exposed daily to an aerosol of the OA conjugate of each monoisocyanate up to day 15. Increases in respiratory rate and/or respiratory collapse occurred in the guinea pigs exposed to TMI-OA and HMI-OA conjugates by days 9 and 15, with RI values of 155 and 177, respectively, being recorded. The greatest mean RI values in guinea pigs exposed to IDM-OA, IMDM-OA and IMTC-OA conjugates up to day 15 were 20, 25 and 22, respectively, and were not indicative of any pulmonary reaction. Guinea pigs exposed in parallel to each test conjugate did not exhibit any pulmonary reaction when they were exposed to OA on the challenge days. All these findings evidence pulmonary hypersensitivity as the result of exposure to TMI-OA and HMI-OA conjugates and suggest a high degree of conjugation and strong linkage of all the monoisocyanates with OA.(ABSTRACT TRUNCATED AT 250 WORDS)

Use of Mishell-Dutton culture for the detection of the immunosuppressive effect of iron-containing compounds.

Mishell-Dutton culture, known as an in vitro model for the evaluation of the humoral immune response of mice spleen cells to sheep red blood cells (SRBC), was used to study the immunosuppressive effect of iron-containing compounds. This response was indicated by the number of antibody forming cell (AFC) per million nucleated cells. Ferrous sulfate and ferric citrate (0.1 mM), when continuously present in Mishell-Dutton culture, significantly decreased the SRBC AFC response by approximately 63% and 86% of the control values, respectively. Ferric citrate, preincubated (24 h) with spleen cells and followed by lavage, significantly decreased the SRBC AFC response by approximately 54% of the control values. Primary and iron-treated coal, in concentrations ranging from 40 micrograms.ml-1 to 120 micrograms.ml-1, significantly decreased the SRBC AFC response when continuously present in Mishell-Dutton culture. Iron-treated coal, suppressed this response, in dose-dependent amounts, to a greater extent than did the primary coal:73% versus 54% at 120 micrograms.ml-1. We concluded that Mishell-Dutton culture is suitable for studying the immunotoxicity of iron and these results may contribute to explain a decrease of host resistance against parasitic and bacterial infection in workers exposed to iron.

Testing natural indigo for genotoxicity.

The genotoxicity of indigo has been assessed by two short-term tests. The mutagenicity of natural indigo was compared with that of synthetic indigo. Both chemicals were tested using the standard procedure of the Salmonella/microsome mutagenicity test as described by Ames. The substance exhibits mutagenicity towards strains TA1538 and TA98 when S9 preparations of rat liver induced with Aroclor 1254 were present in the medium. The clastogenic potential was evaluated by the micronucleus test in the bone marrow of male mice. The test compound was administered twice with an interval of 24 h, the animals were killed 30 h and 54 h after the first treatment. When the test compound was given by oral gavage as two equal dosages of 0.1, 1 and 1.2 g/kg body weight, no statistically significant increase in the percentage of polychromatic erythrocytes with micronuclei was observed for any group treated with natural indigo.

Mutagenicity of nitrosodiethanolamine on Salmonella typhimurium.

Nitrosodiethanolamine was examined in the Ames assay for bacterial mutagens. In absence of S9 activation a mutagenic effect was found.

Cellular uptake, cytotoxic and mutagenic effects of insoluble chromic oxide in V79 Chinese hamster cells.

The cellular uptake, the cytotoxicity and the induction of resistance to 6-thioguanine (6-TG) in Chinese hamster V79 cells exposed to insoluble crystalline trivalent chromium [Cr(III)], Cr2O3, were investigated. Intracytoplasmic Cr2O3 crystalline particle-containing vacuoles were observed by electron microscopy. Concentrations of 50-200 micrograms/ml did not have a marked killing effect but did show a predominantly concentration-dependent inhibitory effect on cell cycle progression with accumulation of cells in G2 phase. Exposure for 18 h to Cr2O3 induced a statistically significant (p less than 0.001) increase in the mutation frequency of up to 10-fold over the controls. Expression time was 6 days for the lowest concentration and 9 days for the highest. Culture of 6-TGr clones in selective media indicated that they were mutants at the hypoxanthine-guanine phosphoribosyl transferase (HGPRT) locus. Examination of growth patterns of Cr2O3-induced mutants showed that, after a delay in reinitiating cell growth, they had varying growth kinetics. The results indicate the ability of a particulate (Cr(III) compound to induce mutation in a mammalian cell system and the usefulness of such systems for detecting genotoxic insoluble metal compounds.

Allergic contact dermatitis from safety clothes and individual protective devices.

Safety clothing and individual protective devices may induce contact dermatitis. Typical clinical patterns cannot always be found. Patch testing must be performed with articles actually used and with specific allergens. In some cases, it is necessary to analyze chemically the article itself.

Experimental sensitization of guinea-pigs to nickel and patch testing with metal samples.

Two groups each of 30 guinea-pigs were painted on 5 days/wk for 4 wk with 1% nickel sulphate in lanolin. The dose was applied to the shaved dorsal skin, which was prepared daily before treatment with sodium lauryl sulphate and injected intradermally each week during this period with 0.1 ml 1% potassium alum in distilled water, close to the site of NiSO4 application. Of the two groups of guinea-pigs submitted to this epicutaneous procedure, 63 and 80% developed skin allergy in response to challenge with 2% NiSO4 after a rest period of 2 wk, whereas no sensitization response was elicited by 1% NiSO4 in the guinea-pig maximization test. When two further groups were sensitized by the epicutaneous procedure, the first group, with a sensitization rate of 52% at the first challenge, showed no decline in response with five successive monthly challenges. Addition of NiCl2 to the drinking-water of the second group did not increase the sensitization rate induced by the monthly rechallenges with NiSO4. In guinea-pigs allergic to nickel, plating of Ni-coated brass discs with chromium as a special surface treatment prevented the occurrence of the contact allergy elicited by brass discs coated with Ni alone, whereas plating with gold/copper/cadmium did not.

Significance of cross-sectional surveys in occupational epidemiology.

This communication discusses the possibility of cross-sectional occupational surveys concealing real occupational risks. For example, occupational factors constitute only one of the etiologic determinants of multifactorial diseases. In addition the diversity of industrial processes leads to a dispersion of risks, and it is difficult to avoid sampling biases both for cases and for referents. The conclusion is drawn that only after several surveys, conducted by different groups and under different circumstances, have shown no risk for a certain occupational factor can such results be considered valid.

[Utilisation of cell transformation tests in the detection of chemical carcinogens (author's transl)]. / Utilisation des tests de transformation cellulaire dans la détection des cancérogènes chimiques.

A great variety of practical short term tests for detecting potential carcinogenic chemicals have been proposed over the last ten years. Tests based on the cellular transformation of mammalian cells in culture are included in this group. After a brief review of the different characteristics of this transformation, the principal cell systems, the methods used and the results obtained by authors who developed and/or use these tests, are presented. It seems justified to include the simplest and most reliable of these tests in the battery of screening tests for the research of potential carcinogenic properties of chemicals. The present orientation of research, likely to lead to more discriminating tests, is discussed.

[Comparative epidemiology, in Europe, of cancers related to tobacco (lung, larynx, pharynx, oral cavity)]. / Epidémiologie comparée, en Europe, des cancers liés au tabac (poumon, larynx, pharynx, cavité buccale).

In 25 European countries, annual age-adjusted mortality and incidence rates, in males, for tobacco-related cancers (lung, larynx, oral cavity), were used in order to study geographic variations in the occurrence of those diseases, from 1952 to 1977. Neither in 1952 (mortality rates), nor in 1977 (mortality and incidence rates), was there any significant geographical correlation between lung cancer on the one hand, and laryngeal or oral cavity cancers on the other hand. Over the 25 years, all countries experienced a sharp increase in lung cancer mortality, especially in association with trends in tobacco consumption. On the contrary, mortality from cancers of the larynx or of the oral cavity showed divergent trends according to countries, since ten of them had steady or decreasing rates. The validity of the method, and the role of alcohol consumption are discussed. Moreover, it is suggested that, in southern european countries, some occupational exposures may be causative factors for laryngeal and oral cavity cancers.

[Continuous electrocardiographic registration in occupational medicine]. / Enregistrement électrocardiographique continu en médecine du travail.

Continuous 24 hour electrocardiography (Holter method) was carried out during work time in 64 workers. They were divided into two groups: the first group comprised 34 subjects with either organic heart disease (coronary artery disease, valvular heart disease, operated coarctation, hypertrophic cardiomyopathy) or a documented arrhythmia without proven underlying cardiac disease; the second group comprised 30 subjects without known cardiac disease but complaining of symptoms suspected to be of cardiac origin or with isolated electrocardiographic abnormalities. At the end of the study we concluded that Holter monitoring is possible in subjects performing physical occupations even in difficult conditions. The trends of heart rate, especially mean heart rate calculated over 10 minute periods, confirmed the relationship between heart rate and the intensity of the physical activity. Atrial extrasystoles and episodes of supraventricular tachycardia were as common in the first as in the second group (20% and 18% respectively). This did not apply to ventricular extrasystoles: they were observed in both groups but were significantly more common in the first group (55% compared to 33%); ventricular extrasystoles, usually of a single configuration and isolated, were more common in the first group, especially amongst the coronary patients. Sinus node dysfunction was only observed in the second group (12.5%), in young subjects, and this occurred with only one exception at night. These findings support previous reports in the literature. However, the interpretation of these results is difficult because of the absence of well established normal values.

[Irritation and allergy to acrylates and methacrylates. - Part I: Common monoacrylates and monomethacrylates (author's transl)]. / Irritation et allergie aux acrylates et méthacrylates. Première partie. Monoacrylates et monométhacrylates simples.

Acrylates and methacrylates are industrial chemicals with insufficiently known irritating and allergenic effects. In this paper, the simple monoacrylates and monomethacrylates are considered. Methyl acrylate is an irritant, giving a reaction in 10 out of 30 patients, when tested at 20 p. 100 in olive oil. It is also an allergen (2 out of 22 cases). Because of its irritating properties, the concentration of 2 p. 100 is proposed for allergeric investigations. Methyl methacrylate, at 20 p. 100 in olive oil, is not an irritant for humans, although we have observed a sensitization rate of about 15 p. 100 with an undiluted product. In animal studies (technic of Kligman and Magnusson), 10 p. 100 of the subjects reacted to a working concentration of 1 p. 100 in petrolatum (allergenicity degree II). A risk of sensitization due to test repetition exists, about 9 p. 100 and 15 p. 100 for methyl acrylate (20 p. 100) and undiluted methyl methacrylate, respectively. For the latter, sensitization appears around the 16 th-18th day and may be preceeded by an irritation (1 out of 3 cases). Allyl acrylate and allyl methacrylate are irritants which should be studied at a concentration of about 0,1 p. 100. A 5 p. 100 concentration in olive oil seems appropriate for studying allergies to the following monoacrylates and monomethacrylates: acrylamide and acrylonitrile, n-butyl, cyclohexyl, ethyl, ethyl-2-hexyl, ethoxy-2-ethyl, phenyl acrylates, cyclohexyl dodecyl, ethyl-2-hexyl, ethoxy-2-ethyl, methyl methacrylates.

[Irritation and allergy to acrylates and methacrylates. - Part II: Polyfunctional acrylic monomers (author's transl)]. / Irritation et allergie aux acrylates et mèthacrylates. Deuxième partie. Monomères acryliques polyfonctionnels.

Acrylates and methacrylates are industrial chemicals with insufficiently known irritating and allergic effects. After considering simples monoacrylates and monomethacrylates, this paper deals with the n-ethyleneglycol acrylates and methacrylates and some polyol polyacrylates and polymethacrylates. All of the diacrylates tested are irritants for humans at 3 p. 100 in olive oil but there is no irritation at 0,1 p. 100. Monomethacrylate and dimethacrylate are not irritants at 3 p. 100 in olive oil. Studies with animals confirm that diacrylates are more irritating than dimethacrylates and the Magnusson and Kligman method shows that the substances induce delayed hypersensitivity. Cross reactions were observed in homogeneous series (diacrylates or dimethacrylates) but not between series. These results are in good agreement with clinical observations. The irritating power of 5 polyacrylates and polymethacrylates of other polyols were tested in animals. For some of them, clinical observations indicate an allergic potential.

G2/M checkpoint stringency is a key parameter in the sensitivity of AML cells to genotoxic stress.

Acute myeloid leukemia (AML) cells exposed to genotoxic agents arrest their cell cycle at the G2/M checkpoint and are inherently chemoresistant. To understand the mechanism of this chemoresistance, we compared the ability of immature CD34+ versus mature CD34- AML cell lines (KG1a and U937, respectively) to recover from a DNA damage-induced cell cycle checkpoint in G2. Here, we report that KG1a cells have a more stringent G2/M checkpoint response than U937 cells. We show that in both cell types, the CDC25B phosphatase participates in the G2/M checkpoint recovery and that its expression is upregulated. Furthermore, we show that CHK1 inhibition by UCN-01 in immature KG1a cells allows checkpoint exit and induces sensitivity to genotoxic agents. Similarly, UCN-01 treatment potentializes genotoxic-induced inhibition of colony formation efficiency of primary leukemic cells from AML patients. Altogether, our results demonstrate that checkpoint stringency varies during the maturation process and indicate that targeting checkpoint mechanisms might represent an attractive therapeutic opportunity for chemoresistant immature AML cells.

[Has N-isopropyl-N'-phenylparaphenylenediamine a place among standard allergens? Importance of this allergen in rubber intolerance]. / La N-isopropyl'N'-phénylparaphénylènediamine a-t-elle sa place dans la batterie standard d'allergènes? Importance de cet allergène dans l'intolérance au caoutchouc.

Allergic contact dermatitis to N-isopropyl-N'-phenylparaphenylenediamine (IPPD) from rubber is far from being exceptional. Out of a total of 56 cases of allergic contact dermatitis to IPPD, 42 were considered as caused by occupational contacts: 17 cases were found in tyre manufacturers, 9 in car-mechanics, 9 in drivers, and 7 in various industrial branches. Out of the 56 cases, 23 also reacted allergically to mercaptobenzothiazole or to tetramethylthiuramdisulphide, or to both of these substances. In a chromatographic analysis of samples of 9 different tyre brands, IPPD was found in 8 cases.

[Toxic dermatitis and pseudo-contact allergy]. / Toxische Dermatitis und Pseudo-Kontaktallergie.

A contact dermatitis is more often due to skin irritation than to allergic reactions. About 80% of occupational dermatoses are explicable as toxic reactions of the skin, 20% as allergic reactions. Frequency and severity of the diseases depends on the nature and concentration of a substance as well as from the duration of its action on the skin. Defense mechanisms against chemicals are influenced by sebum content, humidity and the integrity of the horny layer. From a practical standpoint it is important to differentiate toxic from allergic reactions in a patch-test. It seems that allergic reactions are diagnosed too often. The determination of the critical non-toxic concentration requires the evaluation of a sufficient number of patients. The differentiation of irritation and allergy is tendered more difficult by individual factors. The therapy of toxic and allergic contact dermatitis is discussed.

Nickel allergy: analysis of metal clothing objects and patch testing to metal samples.

In 22 nickel-sensitive subjects, 57 metal clothing objects were said to be not tolerated (37) or tolerated (20). They were analysed by X-ray energy dispersion in electron microscopy, and by the dimethylglyoxime spot test. The correlation between the analytical results and the statements of patients is discussed. Patch tests to nickel-plated metal samples with various thicknesses of chromium (0.25 mu to 1 mu) or gold/copper/cadmium (0.5 mu) were performed in human subjects or in guinea pigs sensitive to nickel. Surface-plating and anticorrosive techniques, as well as the results in nickel-sensitive subjects, are described and discussed. Good tolerance will not be obtained under experimental conditions if nickel in any form is a component of the object. It is to be hoped that appropriate regulations will prohibit the use of nickel in the manufacture of clothing objects.

Patch testing with beryllium alloy samples in guinea pigs.

An experimental study was conducted in guinea pigs for the predictive assessment of the beryllium alloy hazard in occupational exposure of the skin to beryllium compounds. Guinea pigs were sensitized to beryllium sulfate according to the maximized Magnusson and Kligman test, and challenged with beryllium alloys and metallic copper, beryllium and aluminum samples. Results showed a delayed skin hypersensitivity reaction in 30 to 60% of pre-sensitized guinea pigs challenged with copper-beryllium alloys and aluminum-beryllium alloy. An inflammatory follicular reaction was induced by copper in both controls and pre-sensitized guinea pigs.

[Consumption and nutritional contribution of the blue algae (Oscillatoria platensis) among some populations of Kanem (Tchad)]. / Consommation alimentaire et apport nutritionnel des algues bleues (Oscillatoria platensis) chez quelques populations du Kanem (Tchad).

Two food surveys determined the areas of consumption and the ethnic groups involved as well as the way and motivations for using Spirulina algae (Oscillatoria platensis) in Chad. More than 400 homes were visited in February (dry season) and October (end of the rainy season and period after the millet harvest). Consumption is limited to a restricted proportion of the population in the Kanem region. Among the Kanembu group (the leading consumers of Spirulina), frequencies of use vary between one and six melas out of ten. The amounts consumed per person during a meal, in the sauce accompanying millet, are between 9 and 13 g. Variations in consumption linked to ethnic, social and seasonal factors are discussed. With regard to food value, the very high proportion of sand considerably reduces the protein content in the product sold on the market. An average ration of sauce containing "die" helps cover about 10 to 12 p. 100 of the protein requirements of an active adult man, and the algae by themselves contribute 5 to 8 p. 100 of these requirements. A comparison with the leading sauces consumed in Kanem reveals no superiority for Spirulina.