Factors affecting the ratio of cation exchange capacity to clay content in lignite overburden.

Unusually high cation exchange capacity (CEC) values relative to clay content are frequently reported for lignite overburden and minesoils. The CEC to percent clay ratio is commonly greater than one and would require that the average charge of the clay fraction be greater than 100 cmol(c) kg(-1). A comparison of methods for particle-size distribution suggests that the major reason lignite overburden samples have CEC to percent clay ratios greater than one is incomplete dispersion of aggregates of clay minerals or shale fragments. Preliminary investigations revealed the presence of shale fragments, smectite, and partially weathered mica in the silt fraction. Methods commonly used in soil textural analysis underestimated clay content by approximately 24%. The silt fraction may, therefore, provide a "hidden" source of CEC. Another important factor influencing the CEC to percent clay ratio was the presence of organic materials (lignite) in the samples. Lignite may make a significant contribution to CEC in overburden materials. In a study designed to estimate the pH-dependent charge of both the mineral and organic fractions, the CEC of overburden organic constituents was determined to be approximately 158 cmol(c) kg(-1) at pH 8.2. The high CEC to percent clay ratio in lignite overburden and minesoils may be resolved by adjusting methods for clay determination to optimize dispersion and by accounting for CEC due to organic materials. An alternative approach is to use existing methodology and use correction factors to account for incomplete dispersion of clay minerals and the charge contributions of organic materials.

[Pemphigus and pemphigoid]. / Pemphigus et pemphigoïde.

This comparison of the two diseases--pemphigus and pemphigoid--aimed particularly on points of actual interest. Are thus reviewed: (1) the research on the influence of racial or genetic factors in pemphigus vulgaris; (2) the striking differences between the immunological criteria of the two; (3) the clinical polymorphism of pemphigus: besides pemphigus superficialis, non-bullous forms, usually milder, of various types: herpetiformis, circinate ... are now being described; (4) the importance in all cases of eosinophilic spongiosis; (5) the clinical monomorphism of classical bullous pemphigus; on the contrary, the differences, both from clinical and prognostic points of view, in localized bullous pemphigoid (from the benign mucocutaneous form to the severe scarring disease) and in bullous pemphigoid of children; (3) the cases of genuine pemphigus induced by drugs (D-penicillamine, rifampicine) and the problem of the pemphigus-like antibodies; (7) bullous pemphigoid, UV light and practolol; (8) the outstanding association of two major immune diseases, pemphigus vulgaris, myasthenia and thymoma; (9) the mixed bullous dermatoses: pemphigus vulgaris and dermatosis herpetiformis (to separate from herpetiform pemphigus), bullous pemphigoid and dermatosis herpetiformis (bringing up the unsolved problem of mixed or intermediate forms of the two diseases), bullous pemphigoid and pemphigus vulgaris, exceptionally seen, and (10) some news on therapy.

[Strontium 90 in the treatment of pre-cancerous lesions and of some superficial skin cancers (author's transl)]. / Utilisation du strontium 90 dans le traitement des lésions pré-cancéreuses et de certains cancers superficiels de la peau.

The use of strontium 90 has proved to be efficient and practical, because handy, and permitting short treatment, not only, to cure benign superficial tumors and, as reported in this study, of pre-cancerous lesions such as actinic keratosis, Bowen's disease of the skin but also some carefully chosen cases of superficial carcinomas. Hundred lesions have been so treated and followed for 3 years; two only have relapsed. The cosmetic result has been excellent in 80 p. 100.

[Multiple kerato-acanthomas and visceral carcinomas: Torre's syndrome]. / Kérato-acanthomes multiples et carcinomes viscéraux: syndrome de Torre.

Women 63-between 1949 and 1970 has shown 11 K. A., 1 Bowen's diseas of the vulva, a carcinoma of the rectum (together with a carcinoma of the anus). This last association allows to integrate this observation to Torre's syndrome. No return of the K. A. since the removal of the carcinomas (1970) which have not actually come out again.

[Report on two cases of bullous manifestations, one of which being a pemphigus, induced by penicillamine (author's transl)]. / A propos de deux cas d'accidents bulleux, dont un cas de pemphigus, dus à la pénicillamine.

Cutaneous bullous disease may be induced by D-penicillamin. We have briefly reviewed what was then possible: bullosa epidermolysis, pemphigus, bullous toxiderma. We have had the opportunity to observe twice this phenomenon. In one case, as already mentioned about fifteen times in the literature, it was a pemphigus. Its clinical, histological and immunological features are mentioned, and its good prognosis confirmed. The other case gives matter to discussion about toxic pre-pemphigus.

[Pseudo-angiosarcomatosis (kaposi) and arterio-venous fistulae (author's transl)]. / Pseudo-angiosarcomatose de kaposi par fistules artério-veineuses.

In a few cases, arterio-venous fistulae of the lower limbs lead to cutaneous symptoms of the toes, feet or legs exactly similar to Kaposi's disease; the fairly precocious occurrence, the unilateral localisation, the existence of clinical and radiological arterial symptoms and usually, but not always, particular histological features allow this discrimination. Seen in both sex, male prevailing, between 12 and 50, it can simulate Kaposi's disease even on histological grounds; the diagnosis may, then, be difficult inasmuch as vascular symptoms may clinically lack. The development may be very different from one case to another so that there is no standard treatment between "wait and see" and more or less extensive amputation.

[Lichen striatus; histologic features (author's transl)]. / "Lichen striatus" critères histologiques (a propos de cinq cas)

The histologic picture of lichen striatus is not uniform and changes, as it seems, with the "oldness" of the lesion; showing: sometimes a dense lympho-histiocytic infiltrate of the papillary dermis and epidermis, sometimes features of atypical lichen planus. The existence of spongiotic vesicles in the low epidermis and in certain late forms, pictures of disruption of the basal layer with residual cavities compose particular data of the disease.

[Cutaneous cholesterol emboli (author's transl)]. / Les manifestations cutanées des emoblies de critaux de cholestérol

Fifty cases from the literature and one personal case of cutaneous cholesterol embioli are reviewed. These emboli come from abdominal atheromatous aotitis, sometimes complicated by aneurysm. The cholesterol micro-embolism is sometices induced by vascular surgery or arterial opacification. Male prevalence (47 cases) is evident. Alone or with visceral involvement, cutaneous lesions frequently simulate periarteritis nodosa: circumscribed to abdomen, thighs, legs, dorsum of the feet, the livedo reticularis is the most stricking feature associated or not with cutaneous nodes, purple toes, ulcers and gangrene. Histopathologic study is required for diagnosis: showing "negative" pictures of cholesterol cristals in an obliterating arteriolitis. Nevertheless special intetest is focused on a macrophagic granuloma centered in the vessel.

[Diffuse skin mastocytosis of nurslings. 3 clinical cases with bullous manifestations]. / Mastocytose cutanée diffuse du nourrisson. A propos de 3 observations avec manifestations bulleuses

Three nurslings are described with diffuse mast cell disease characterized by blisters on widespread skin involvement. The skin changes may be associated with important generalized flares in relation with degranulating mast cell. The mastocytosis infiltrats seems localized to the skin. The skin lesions heal or regress slowly as in other mast cell disorders but long-term evolution remains very impredictable.