ABSTRACT
The factors affecting the ability of a bacterial species to degrade different amounts of toluene (8.5 to 217 mg/g) sorbed to granular activated carbon (GAC), in an aqueous solution of mineral salts, were investigated. After 144 days the amounts of toluene remaining on one type of GAC ranged from 7.5 to 9.5 mg/g, and the aqueous concentrations of toluene ranged from 2 to 7 micrograms/L. Neither bacterial death nor an inhibition by accumulating by-products could explain why the remaining toluene had not been degraded. However, at these low concentrations of toluene, and probably because of cell starvation, bacteria were observed to be more than 100-times less efficient to degrade toluene than at high concentrations. We propose that this low degradation ability is responsible for the presence of residual toluene on the GAC, and that this mechanism may contribute to the persistence of low concentrations of sorbed pollutants in the environment.
Subject(s)
Soil Microbiology , Soil Pollutants/pharmacokinetics , Toluene/pharmacokinetics , Biodegradation, Environmental , Charcoal , Dose-Response Relationship, Drug , Soil Pollutants/metabolism , Toluene/metabolismABSTRACT
The fate of pyrimidine-2-14C-rimsulfuron in a rendzina soil was investigated using a laboratory microcosm approach. Measurement of CO2 evolution suggested that rimsulfuron applied at 5 times the recommended dose did not affect soil respiration. Under abiotic conditions, no mineralization of 14C-rimsulfuron into 14C-CO2 occurred and under biotic ones it was very low reaching 0.75% of the applied 14C-rimsulfuron after 246 days of incubation. The analysis of data showed that a three-half order model provided the best fit for the mineralization curve. Extractable 14C-residues decreased over time to 70-80% of the applied 14C-rimsulfuron at the end of the incubation. After 246 days of incubation, non extractable residues (NER) accounted for up to 24.7% of the applied 14C-rimsulfuron and were distributed according to organic carbon in soil size fractions, suggesting a progressive incorporation process of NER to soil humus.
Subject(s)
Herbicides/metabolism , Soil Microbiology , Soil Pollutants/metabolism , Urea/analogs & derivatives , Carbon Radioisotopes , Herbicides/chemistry , Minerals/metabolism , Soil/analysis , Urea/chemistry , Urea/metabolismABSTRACT
The naso-pharyngo-oral leishmaniasis is not limited to South America. Cases have been reported in Africa showing that its prevalence in this area has been underrated. Its diagnosis is easy and early treatment will prevent facial lesions.
Subject(s)
Leishmaniasis, Mucocutaneous/epidemiology , Leishmaniasis/epidemiology , Adult , Africa , Humans , Infant , Leishmaniasis/diagnosis , Leishmaniasis/drug therapy , Leishmaniasis, Mucocutaneous/diagnosis , Leishmaniasis, Mucocutaneous/drug therapy , MaleABSTRACT
Hemoglobinopathies and specially drepanocytosis SS and its heterozygotic form SC are responsible of important pathological changes of retina. These changes caused by ischaemia due to vascular thrombosis are generally silent at their beginning, because of their first development in a peripheral area. They have a tendency to progress towards the posterior pole and to get complicated by hemorrhages and detachment of retina. Their study is still to be completed but these disorders already appear as being an important cause of blindness in the populations concerned by this hemoglobinopathy. Treatment is unsatisfactory.
Subject(s)
Anemia, Sickle Cell/complications , Retinal Diseases/etiology , Anemia, Sickle Cell/genetics , Anemia, Sickle Cell/physiopathology , Hemoglobin A/analysis , Hemoglobin, Sickle/analysis , Heterozygote , Humans , Retinal Diseases/physiopathology , Retinal Hemorrhage/physiopathology , Retinal Vessels/physiopathologyABSTRACT
A review of the question of primitive wide angle chronic glaucoma in Negroes. Its frequency, early apparition, frequent unilateral localization and poor improvement with medical treatment are emphasized. The present trends in surgical procedures are given.
Subject(s)
Black or African American , Glaucoma/epidemiology , Adolescent , Adult , Africa , Age Factors , Black People , Child , Female , Glaucoma/therapy , Humans , Male , Sex FactorsABSTRACT
The use of overdoses of amino-4-quinoleines in non-malarial diseases has demonstrated various toxic actions on eyes. The most severe is retina lesion. Metabolism of these drugs and pathogeny of the lesions are discussed. With regard to aetiology, the main factor is overdose and duration of treatment. Clinical aspects are classified in three phases; the third one is divided in 5 stages. Treatment is only prophylactic.
Subject(s)
Aminoquinolines/adverse effects , Retinal Diseases/chemically induced , Adult , Aminoquinolines/therapeutic use , Child , Dose-Response Relationship, Drug , Humans , Pigment Epithelium of Eye/drug effects , Retina/drug effects , Retinal Diseases/diagnosisABSTRACT
The authors report a case of pure macular oedema. After ruling out all other etiologies, the diagnosis of schistosomiasis due to Schistosoma mansoni was established, with parasitologic and serologic proofs. The specific treatment was followed up by a progressive restoration associated with an acute increase of eosinophila. The question of ocular damages in schistosomiasis is exposed according to the existant litterature: 1) Presence of schistosoma eggs in the ocular area. 2) Presence of adult schistosome in the eyeball. 3) Ocular troubles assumed to be in relation with the presence of adult worm or to larva.
Subject(s)
Retinitis/diagnosis , Schistosomiasis/diagnosis , Adult , Chorioretinitis/diagnosis , Chorioretinitis/parasitology , Conjunctivitis/diagnosis , Conjunctivitis/parasitology , Eye/parasitology , Fluorescein Angiography , Humans , Male , Parasite Egg Count , Retinitis/parasitology , Schistosoma mansoni , Schistosomiasis/parasitologyABSTRACT
A case of a trachoma at scar-stage with entropion-trichiasis is recorded. The patient was a white woman having spent her whole life in Saint-Pierre and Miquelon Islands which are not affected by trachoma. The authors, then, review the present trends about the extraocular and ocular diseases caused by Chlamydia trachomatis.
Subject(s)
Trachoma/epidemiology , Atlantic Islands , Female , Humans , Middle Aged , Trachoma/complications , Trachoma/etiologyABSTRACT
Following an up-to-date bacteriological resume, are recalled the most important clinical manifestations presently attributed to C. trachomatis: general manifestations (pulmonary, articular, venereal, congenital, viscereal and others still under discussion); ocular manifestations (trachoma, inclusion conjunctivitis of newborn infants or adults, other ocular affections still under discussion). The main theories are exposed, which try to explain some epidemiological links between all these manifestations.
Subject(s)
Chlamydia Infections/complications , Conjunctivitis, Inclusion/diagnosis , Eye Diseases/etiology , Trachoma/diagnosis , Adult , Age Factors , Animals , Child , Chlamydia Infections/diagnosis , Chlamydia Infections/transmission , Chlamydia trachomatis/growth & development , Chlamydophila psittaci/growth & development , Conjunctivitis/etiology , Diagnosis, Differential , Female , Humans , Infant , Infant, Newborn , Lymphogranuloma Venereum/complications , Male , Psittacosis/complicationsABSTRACT
Modern authors estimate from 47 p. 100 to 78 p. 100 the frequency of ocular lesions in leprosy. This frequency varies according to the duration and type of the disease. These lesions may result from a paralysis of the V or VII cranial nerves, or from a bacteremia, but, more probably, from a spreading of the bacilli from the nasal cavity through the lacrymal ducts. The various lesions of each ocular structure are described with reference to the T. or L. type of leprosy.
Subject(s)
Eye Diseases/diagnosis , Leprosy/diagnosis , Diagnosis, Differential , Endophthalmitis/diagnosis , Facial Nerve , Humans , Peripheral Nervous System Diseases/diagnosis , Trigeminal NerveABSTRACT
The authors present a case of muco-cutaneous leishmaniasis in the Republic of Chad. In that case, a long duration treatment with corticoids entailed the generalization of the disease in the form of a secondary kala-azar and the appearance of a histiocytosarcoma on the scar left by the oriental sore. Comments on the pathogenesis of leishmaniasis are then exposed.