Analysis of lymphocyte and oral mucosa cell micronuclei in Cuban paint industry workers

Twenty-one workers exposed to complex mixtures in the paint industry were compared with a control group of 19 persons from a blood bank in regard to micronuclei frequency in peripheral blood lymphocytes and in oral mucosa cells. The exposed persons showed significantly increased levels of micronuclei frequencies in both types of cells.

Biodiversity conservation demands open access

Open access is vital to the progress of scientific thought and advancement of many disciplines, but particularly so for conservation science

Studies on the photostability and phototoxicity of aloe-emodin, emodin and rhein

Aloe-emodin (1), emodin (2) and rhein (3) were found to be photolabile by visible (390-500 nm) light under aerobic conditions. The drugs 1, 2 and 3 were phototoxic in vitro when examined by the photohemolysis test under both oxygen and argon atmospheres, although the photohemolysis rate was markedly lower under anaerobic conditions. The experiments were also carried out in the presence of butylated hydroxyanisole (BHA), reduced glutathione (GSH), sodium azide (NaN3) and superoxide dismutase (SOD). Based on the inhibition of this process on addition of BHA, GSH, SOD and NaN3, there would seem to be involvement of free radicals (type I mechanism) and singlet oxygen in the process (type II mechanism). The in vitro phototoxicity of this anthraquinone series was also verified in a lipid-photoperoxidation test with linoleic acid. In summary, this anthraquinone series is phototoxic in vitro. This behavior can be explained through the involvement of singlet oxygen and stable photoproducts.

Visceral leishmaniasis in a Brazilian child infected perinatally with human immunodeficiency virus

This report describes a Brazilian child perinatally infected by HIV who presented visceral leishmaniasis. She showed the classic clinical features, and diagnosis was made by demonstration of amastigote forms of Leishmania in bone marrow aspirate. She responded well to traditional treatment with meglubine.

First Report of Fusarium Wilt of Babaco (Carica × heilbornii var. pentagona) in Ecuador

Babaco, Carica × heilbornii V.M. Badillo var. pentagona (Heilborn) V.M. Badillo, is a fruit native to Ecuador that has great potential as a cultivated crop. Local market demand and strong potential as an export crop have greatly increased interest in babaco production in Ecuador. Although the crop can be produced in open fields, the majority of crop production is in plastic greenhouses. In 1996, a serious wilt disease developed on babaco in several greenhouses, resulting in up to 100% loss of plants. Symptoms first appeared as chlorosis of the lower leaves, followed by defoliation progressing up the stem until the entire plant was defoliated. When cut in cross section, vascular discoloration was observed in the stem. Eventually necrosis and soft rot of the stem occurred and entire plants collapsed. Fungal isolations were conducted from fine feeder roots of diseased plants by soaking root pieces (2 cm long) in a 0.5% solution of sodium hypochlorite for 3 min. Root pieces were cut into smaller sections and placed on potato dextrose (PDA) or corn meal (CMA) agar in petri dishes. Isolations from larger roots, crowns, stems and fruits were made by soaking tissue sections of each plant part in a 2.87% solution of sodium hypochlorite for 3 min. Tissue sections were rinsed three times in sterile distilled water. Smaller tissue sections (≈0.125 cm³) were cut from surface-disinfested pieces and placed on PDA and CMA in petri dishes. Cultures were incubated at 20°C. A fungus resembling Fusarium sp. was isolated consistently from infected tissues from all infected plant parts. Based on the morphology of the fungal colony and conidia from monosporic isolations, the fungus was identified as Fusarium oxysporum Schlechtend:Fr. (1). Pathogenicity tests were conducted by growing babaco plants in pots containing an equal mixture of sterilized soil, compost, and sand in the greenhouse. Eight 7-month-old plants were inoculated by placing 40 ml of a suspension (10⁶ conidia per ml) of F. oxysporum in four plastic straws placed in the soil (5 cm depth) at equal distances (5 cm) from the base of each plant. Straws around noninoculated control plants received sterile water. Plants were watered with 400 ml of sterile water daily. Pathogenicity tests were repeated once as described. All inoculated plants developed typical wilt symptoms within 45 days after inoculation. No symptoms developed on uninoculated control plants. F. oxysporum was successfully reisolated from infected stem tissues of inoculated plants. Incidence of Fusarium vascular wilt of babaco has continued to increase since 1996 and is currently the major constraint to production. References: (1) P. E. Nelson et al. 1981. Fusarium: Diseases, Biology, and Taxonomy. The Pennsylvania State University Press, University Park.

[Radiation therapy and cardiac pacemakers]

The number of patients with cardiac pacemakers submitted annually to radiation therapy is increasing. Radiation therapy causes interference in the normal functioning processes, directly by chemical changes in the structure of the device and also by electromagnetic disturbances generated in the process of treatment. The changes in the technology used in the manufacture of cardiac pacemakers after the 70's, with the introduction of complementary metal-oxide semi-conductors (CMOS) in the circuits, drastically increased the chance of dangerous interference in the normal function of cardiac pacemakers occurring when in contact with an ionizing radiation source. The authors briefly describe the mechanisms underlying the radio-induced damage usually observed. A review of the literature on this issue is made and solutions are pointed out to perform safe radiation therapy and minimize the risk of device malfunction.

[Pubic hair in children and late onset congenital adrenal hyperplasia]

Before the age of 8 in females and 9 in males, the presence of pubic hair can be the first sign of a gonadal or adrenal disease. In order to identify the late onset type of congenital adrenal hyperplasia in premature pubescence, we did the adrenal short stimulation test with Synacthen, on 30 children. Five girls and one boy showed a 21-hydroxylase deficiency, in which the seric 17-OH Progesterone at 60 minutes is 28.8 +/- 15.2 ng/ml, being in a control group 2.30 +/- 0.8 ng/ml [p less than 0.01]. The 20% incidence we have found, justifies the testing of every premature pubescent child.

Mutagenicity of N-nitrosomorpholine biosynthesized from morpholine in the presence of nitrate and its inhibition by ascorbic acid

N-nitrosomorpholine biosynthesis and inhibition in mice treated with nitrate, morpholine and ascorbic acid, was studied by means of the mutagenic activity in urine samples. The preincubation method was used and Salmonella typhimurium TA 1535 was the test strain. The results suggest that N-nitrosomorpholine biosynthesis was carried out when the animals were fed high doses of nitrate, however ascorbic acid was an inhibitor of this process.

[Zinc and porphyria cutanea tarda]

In 30 patients affected by Porphyria Cutanea Tarda we determined: plasmatic, erythrocytary and urinary zinc (by atomic absorption spectrophotometry); total porphyrins in plasma and in urines, coproporphyrins and protoporphyrins in erythrocytes (by spectrophotometric methods); haptoglobin, hemopexin, alpha 2-macroglobulin and albumin (by immunological methods). The results obtained were compared with those of normal subjects. In addition, the variables under consideration were statistically analyzed to bring out possible correlations (both simple and partial). The most interesting result (besides the documentation of an increase in the urinary and plasmatic zinc in porphyric patients) was the finding of correlations between plasmatic zinc, plasmatic porphyrins and alpha 2-macroglobulin.

Inhibition of the platelet reaction by a high molecular weight phosphoglycoprotein isolated from human platelet plasma membranes

The effect of phospho-glycoprotein (HMW-GP), obtained from human platelet plasma membranes, on the aggregation and secretion of human platelets was studied. Incubation of PRP with 4 to 16 micrograms/ml of HMW-GP results in inhibition of ADP-, Epinephrine-, Collagen-, and Thrombin-induced platelet aggregation. The effect is mainly reflected on the secondary wave of aggregation. The inhibitory effect is partially overcome by higher concentrations of inducers, however, even under these conditions, a clear tendency towards disaggregation is observed. 5HT release (Col-induced) is strongly decreased from 50% to 4.5. The inhibitory effect on Thrombin-induced aggregation is markedly dependent on external calcium, being maximal at 5 mM calcium. The HMW-GP does not bind ADP or Thrombin. Membrane conformation is markedly affected, as evidenced by the effect of HMW-GP on the iodination of surface polypeptides of intact platelets. It is suggested that interaction of HMW-GP with the platelet membrane blocks the signal(s) transmission that links stimulus to activation. The inhibition observed might just represent an experimental amplification of the endogenous modulatory function that has been proposed for this high molecular weight phosphoglycoprotein.