Brevipalpus-transmitted plant virus and virus-like diseases: cytopathology and some recent cases.

An increasing number of diseases transmitted by Brevipalpus mite species (Acari: Tenuipalpidae) is being identified that affect economically important plants such as citrus, coffee, passion fruit, orchids, and several ornamentals. All of these diseases are characterized by localized lesions (chlorotic, green spots, or ringspots) on leaves, stems, and fruits. Virus or virus-like agents are considered to be the causal agents, possibly transmitted in a circulative-propagative manner by Brevipalpus mites.

A comparative evaluation of the Papanicolaou test for the diagnosis of trichomoniasis.

Background: Trichomoniasis is the most prevalent nonviral sexually transmitted disease in humans worldwide. In addition to its pathologic implications, trichomoniasis is a risk factor for the transmission of the HIV and is associated with reproductive complications in females. Diagnosis of the disease is problematic due to inadequate accuracy of current diagnostic methods.

Petunia vein banding virus: Characterization of a New Tymovirus from Petunia × hybrida.

Petunia plants from a nursery in the State of Rio Grande do Sul, Brazil, showed pronounced vein banding and contained isometric particles with diameters of approximately 45 and 30 nm. The larger ones apparently represent a caulimovirus, while the smaller ones, which included both empty shells and full particles, were identified as those of a new tymovirus for which we propose the name Petunia vein banding virus (PetVBV). Originally, PetVBV was transmitted only with difficulty to healthy petunia plants.

Oxidative stress in familial adenomatous polyposis.

The prooxidant/antioxidant imbalance in familial adenomatous polyposis (FAP) is suggested by (i) the intimate connection between APC and prostaglandin H synthase-2 genes, (ii) the increase of the free radical-generating enzyme xanthine oxidase, and (iii) the decrease of antioxidant defences. In this research work we evaluated lipid peroxidation measuring the thiobarbituric acid (TBA) reactive products and we studied the activities of superoxide dismutase (SOD) and catalase as well as the levels of ascorbate and tocopherols in the peripheral blood cells from a total of 27 FAP patients and 83 normal controls. TBA-reactive products were determined according to a previously published method.

Ouabain-insensitive Na(+)-ATPase activity in Trypanosoma cruzi epimastigotes.

In the present paper, the presence of a ouabain-insensitive Na(+)-stimulated, Mg(2+)-dependent ATPase activity in T. cruzi epimastigotes CL14 clone and Y strain was investigated. The increase in Na+ concentration (from 5 to 170 mM), in the presence of 2 mM ouabain, increases the ATPase activity in a saturable manner along a rectangular hyperbola.

Trypanosoma cruzi epimastigotes express the ouabain- and vanadate-sensitive (Na(+)+K+)ATPase activity.

The presence of (Na(+)+K+)ATPase activity in CL14 clone and NIH NTY strain of Trypanosoma cruzi epimastigotes is demonstrated. A Na+ plus K+ stimulated ATPase activity is found in both strains. The optimal Na+/K+ ratio is 5:1 and 9:1 in CL14 clone and NIH NTY strain, respectively.

Differences in the isodesmin pattern between the electric organs of Electrophorus electricus L.

Desmin, the intermediate filament protein of muscle, is present in the electric organs of Electrophorus electricus L. as five isovariants, instead of the one to two isovariants found in muscle. We analyzed the isodesmin pattern in the three different electric organs using densitometry of Coomassie blue-stained bands in electrofocusing polyacrylamide gel electrophoresis.

[Genetic diagnosis of familial adenomatous polyposis: detection of APC gene mutations based on an in vitro synthetized protein].

Familial adenomatous polyposis of the colon (FAP) is a dominant autosomic disease in which virtually 100% of the affected individuals develop colorectal cancer before the age of forty. The gene responsible for this disease (APC gene) is mutated in the germ line of these patients. The genetic diagnosis of FAP was initially done using linkage analysis.

Desmin and actin filaments in membrane-cytoskeletal preparations of the electric tissue of Electrophorus electricus, L.

The electrocyte of the electric organ of the electric eel, Electrophorus electricus, L was investigated by light and electron microscopy as well as immuno-electron microscopy, in order to clarify the fine structures and distribution of cytoskeleton filaments and their relations to proteins, especially desmin and actin. Cytoskeleton-enriched fractions of the electrocytes were analysed with SDS-PAGE. It was verified that a meshwork of filaments was distributed in the electrocytes, more abundantly in the anterior than in the posterior part of the cell, and that this could be associated with membrane invaginations.

Effect of adenosine on the ouabain-insensitive Na+-ATPase activity from basolateral membrane of the proximal tubule.

The regulation of the furosemide-sensitive Na+-ATPase activity and ouabain-sensitive (Na+ + K+)ATPase activities from proximal tubules by adenosine was investigated. When the concentration of adenosine was increased the furosemide-sensitive ATPase activity decreased with maximal inhibition at 10(-8) M (56% of inhibition). However, the (Na+ + K+)ATPase activity was not affected by adenosine.

Thyroid hormone induces protein secretion and morphological changes in astroglial cells with an increase in expression of glial fibrillary acidic protein.

Thyroid hormone (T3) induces in vitro differentiation of astrocytes from the developing rat brain. T3 treatment induced the appearance of long processes in cultured cerebral hemisphere and mesencephalon astrocytes from embryonic and newborn rats. T3 treatment also produced a change in the morphology of cultured cerebellar astrocytes from 10-day-old rats, but not in cerebellar astrocytes from newborn rats.

Effects [correction of Effecs] of the thyroid hormone (T3) on astrocytes.

Thyroid hormones have profound effects on growth and development. In the brain L-3,5,3'-triiodothyronine (T3), the bioactive hormone, is involved with the harmonious development acting in neuronal and glial cell differentiation. T3 acts on the cells by interacting with nuclear receptors that can regulate the expression of several genes.

Desmin filaments in the electrocytes of the electric organ of the electric eel Electrophorus electricus.

Desmin protein is an abundant constituent of the intermediate filaments in the electrocytes of the electric organ of the electric eel Electrophorus electricus. Polyclonal antibodies were raised against purified desmin from the electric organ and used for immunolabeling of the protein in reconstituted filaments. In thick sections of the main electric organ that has been stained with fluorescein-labeled desmin-specific antibodies, light microscope revealed a diffuse meshwork of desmin filaments dispersed in the cytoplasm of electrocytes.

Anti-Helicobacter pylori antibodies prevalence and gastric adenocarcinoma in Portugal: report of a case-control study.

Evidence from large cohort studies has established an increased risk of gastric cancer for individuals infected with Helicobacter pylori (HP). In low incidence countries, like the United Kingdom and Sweden, case-control studies suggested that the prevalence of anti-HP antibodies in gastric cancer patients (at the time of cancer diagnosis) is greater than in control populations. We present results from a case-control study of the prevalence of IgG anti-HP antibodies in gastric cancer patients and a control population in a country with a high incidence of gastric cancer.

[Value of congenital hypertrophy of the retinal pigment epithelium as diagnostic marker in familial adenomatous polyposis].

Familial Adenomatous Polyposis (FAP) is a dominant autosomic disease characterized by the development of hundreds to thousands of colonic adenomatous polyps. Affected patients have a 100% risk of colon cancer development if they are not submitted to a prophylactic colectomy. Identification of carriers depends on the detection of colonic polyps, and endoscopic surveillance must be offered to all descendents, including healthy individuals.

Abnormal proteins in the cerebrospinal fluid of a patient with Creutzfeldt-Jakob disease following administration of human pituitary growth hormone.

A Brazilian case of Creutzfeldt-Jakob disease in a hypopituitary patient who had received cadaver-derived human pituitary growth hormone between 1968 and 1977 is reported. The clinical diagnosis was confirmed during his lifetime by the demonstration of two abnormal 30-kDa proteins in the cerebrospinal fluid by two-dimensional gel electrophoresis. These proteins, characteristic of Creutzfeldt-Jakob disease, present isoelectric points of 5.

MyoD converts primary dermal fibroblasts, chondroblasts, smooth muscle, and retinal pigmented epithelial cells into striated mononucleated myoblasts and multinucleated myotubes.

Shortly after their birth, postmitotic mononucleated myoblasts in myotomes, limb buds, and conventional muscle cultures elongate and assemble a cohort of myofibrillar proteins into definitively striated myofibrils. MyoD induces a number of immortalized and/or transformed nonmuscle cells to express desmin and several myofibrillar proteins and to fuse into myosacs. We now report that MyoD converts normal dermal fibroblasts, chondroblasts, gizzard smooth muscle, and pigmented retinal epithelial cells into elongated postmitotic mononucleated striated myoblasts.

Mouse brain Tau proteins: microheterogeneity and phosphorylation.

Tau proteins are involved in polymerization of tubulin into microtubules. They comprise a heterogeneous group of proteins that can be resolved by two-dimensional gel electrophoresis using a non-equilibrium pH gradient in the first dimension. Developmental studies show that mouse brain Tau proteins are more heterogeneous in 15-day old mice than in newborn pups or adults.

Desmin heterogeneity in the main electric organ of Electrophorus electricus.

Desmin, the muscle-specific intermediate filament protein was purified from the main electric organ of Electrophorus electricus. It is shown that pure desmin can be separated into 5 isoforms presenting different isoelectric points. These isoforms have similar molecular weight, react with an antibody directed against desmin and generate identical peptides after digestion with protease V8 from Staphylococcus aureus.

[Alpha-actinin in the electric organ of Electrophorus electricus, L].

We have identified Alpha-actinin from the electric organ of the Electrophorus electricus, L. It was analysed by polyacrylamide gel electrophoresis, and identified by immunoblotting. This protein was also found in a membrane fraction of the electric organ enriched with components of the cytoskeleton.