Morphological alterations induced by boric acid and fipronil in the midgut of worker honeybee (Apis mellifera L.) larvae

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Differences in mushroom bodies morphogenesis in workers, queens and drones of Apis mellifera: Neuroblasts proliferation and death

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Mitosis and cell death in the optic lobes of workers, queens and drones of the honey bee (Apis mellifera) during metamorphosis

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Ecdysteroid levels changed by permethrin action in female Rhipicephalus sanguineus (Latreille, 1806) (Acari: Ixodidae) ticks

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Evaluation of the biological control by the yeast Torulaspora globosa against Colletotrichum sublineolum in sorghum

The yeasts are microorganisms with great potential for biotechnological applications in diverse areas. The biological control of phytopathogens by yeasts has showed satisfactory results under laboratory conditions, and it has already produced commercial formulations. With this as focus, this work aims to perform in vitro and in vivo evaluations of the action of a Torulaspora globosa yeast strain (1S112), isolated from sugarcane rhizosphere, against the phytopathogenic mold Colletotrichum sublineolum, the causative agent of anthracnose in sorghum. In vitro experiments included the antagonism test in Petri dishes with morphological hyphal evaluation; yeast killer activity; siderophore, volatile compound and hydrolytic enzyme production. In vivo experiments were conducted in greenhouse conditions with a sorghum variety susceptible to C. sublineolum by evaluating the anthracnose disease for 6 weeks. The results indicated that the yeast strain significantly controlled the fungal growth, either in vitro or in vivo. The strain of T. globosa exhibited killer activity against two sensitive strains, which is a novel capacity for this species. The yeast did not produce siderophores, volatile compounds or hydrolytic enzymes, although it has reduced the mycelial growth, resulting in hyphal deformities but not cell death. The yeast controlled the anthracnose disease in sorghum, either inoculated before or after the fungal spores, suggesting that the competition for space and nutrients to dominate the mold and killer toxin production, altering the hyphal morphology, are mechanisms utilized by the yeast in the biocontrol.

Casearin X exhibits cytotoxic effects in leukemia cells triggered by apoptosis

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Methylation status of CDH1 gene in samples of gastric mucous from brazilian patients with chronic gastritis infected by Helicobacter pylori

CONTEXTO:O câncer gástrico é uma das principais neoplasias que causam o óbito no Brasil e no mundo. Helicobacter pylori é um carcinógeno do tipo I relacionado à gastrite crônica. Diferenças no grau de virulência de suas cepas levam a maior risco de desenvolvimento de doenças gástricas. A metilação de ilhas CpGs está envolvida com o processo de tumorigênese em diferentes tipos de câncer. CDH1 é um gene supressor tumoral que, quando inativado, pode aumentar as chances de metástase. A metilação deste gene em estágios precoces da carcinogênese gástrica ainda não é totalmente compreendida. OBJETIVO: Investigar o padrão de metilação do gene CDH1 em amostras de gastrites crônicas e correlacionar com a presença do H. pylori. MÉTODOS: Foram usadas 60 biopsias de mucosas gástricas. A detecção de H. pylori foi realizada por PCR para o gene da urease C e a genotipagem com PCR para os genes cagA e vacA (região s e m). O padrão de metilação do gene CDH1 foi analisado usando a técnica de PCR e específica para a metilação e sequenciamento direto dos produtos de PCR. RESULTADOS: A bactéria H. pylori foi detectada em 90% das amostras de gastrites crônicas; destas, 33% portavam o gene cagA e 100% vacA s1. O genótipo vacA s2/m1 não foi detectado nas amostras analisadas. Metilação de CDH1 foi detectada em 63,3% das amostras de gastrites e 95% delas eram portadoras de H. pylori. CONCLUSÃO: Os resultados deste estudo sugerem que a metilação em CDH1 e a infecção pelo H. pylori são eventos frequentes em amostras de pacientes brasileiros com gastrite crônica e reforça a correlação entre infecção por H. pylori e inativação do gene CDH1 em estágios precoces da tumorigênese gástrica.

Venomous mollusks: the risks of human accidents by conus snails (gastropoda: conidae) in Brazil

Os moluscos do gênero Conus apresentam um aparato venenoso composto de uma rádula quitinosa ligada a glândulas de peçonha, causando envenenamentos humanos graves e mesmo óbitos pela ação neurotóxica indutora do bloqueio de vários receptores e paralisia muscular. Não há casos descritos de envenenamento no país, mas determinadas populações correm risco de acidentes.

Stereological study of acinar growth in the rat parotid gland induced by isoproterenol

The growth of the rat parotid gland induced by daily treatment with isoproterenol (IPR) for 2 weeks was investigated by stereological methods applied to light microscopy. After 7 days of treatment, the glandular mass presented a 286% growth, with the first 3 days being the period of greatest growth. Total acinar volume exhibited a 363% increase during the period from 0 to 7 days, while acinar-cell volume presented a 468% growth from 0 to 5 days of treatment. on the other hand, total acinar-cell number did not increase during the study period. Thus, under the conditions used, IPR-stimulated gland growth wits essentially hypertrophic. However, a significant increase in the number of bipolar and multipolar mitoses was also observed, especially on the third and fifth days of treatment. As no increase in acinar-cell number occurred during growth, the presence of these mitoses suggests that cell death occurred during gland growth. on this basis, bipolar mitoses may occur to replace cells that probably degenerated during treatment, whereas multipolar mitoses may lead to the occurrence of polyploidy. (C) 1997 Elsevier B.V. Ltd.

Cell death in ovarioles causes permanent sterility in Frieseomelitta varia worker bees

Frieseomelitta varia worker bees do not lay eggs even when living in queenless colonies, a condition that favors ovary development and oviposition in the majority of highly social bees. The permanent sterility of these worker bees was initially attributed to a failure in ovary morphogenesis and differentiation. Using transmission electron microscopy we found that at the beginning of the pupal phase the ovaries of F. varia workers are formed by four ovarioles, each of them composed of 1) a terminal filament at the apex of the ovarioles, containing juxtaposed and irregularly shaped cells, 2) a germarium with clusters of cystocytes and prefollicular cells showing long cytoplasmic projections that envelop the cystocyte clusters, 3) fusiform interfollicular and basal stalk precursor cells, and 4) globular, irregularly contoured basal cells with large nuclei. However, during the pupal phase an accentuated and progressive process of cell death takes place in the ovarioles. The dying cells are characterized by large membrane bodies, electron-dense apoptotic bodies, vacuoles, vesiculation, secondary lysosomes, enlarged rough endoplasmic reticulum cisternae, swollen mitochondria, pycnotic nuclei, masses of chromatin adjacent to the convoluted nuclear envelope, and nucleoli showing signs of fragmentation. Cell death continues in ovarioles even after the emergence of the workers. Once they become nurse bees, the ovaries have become transformed into a cell mass in which structurally organized ovarioles can no longer be identified. In F. varia workers, ovariole cell death most certainly is part of the program of caste differentiation.

Hepatic bleeding induced by streptokinase and heparin in a patient with acute myocardial infarction

Although rare, major bleeding is the most important side effect of thrombolytic therapy in acute myocardial infarction (AMI) (Levine et al., 1995). Spontaneous hepatic bleeding in normal liver after thrombolytic administration has rarely been reported in literature. To our knowledge, there are only three cases of hepatic bleeding related to thrombolytic therapy in AMI. In these, the used drugs were anisolylated plasminogen streptokinase activator complex (APSAC) (Garcia-Jiménez et al., 1997; Fox et al., 1991) and rt-PA (Garcia-Jiménez et al., 1997). We report a case of hepatic bleeding after streptokinase followed by units over 60 minutes). The next day, the patient developed third-degree atrioventricular block and a temporary pacemaker was inserted. Twenty-seven hours after streptokinase infusion, the patient complained of refractory chest pain that was interpreted as post-myocardial infarction angina; clotting screen was normal and intravenous heparin was started (80 U/kg followed by 18 U/kg/hour). After four hours of heparin administration, the patient presented abdominal pain and distension, and his blood pressure and hematocrit level dropped. Abdominal ultrasonography revealed free fluid in the peritoneal cavity (about 3,000 mL). A laparotomy disclosed blood in the abdominal cavity with bleeding from the right lateral hepatic segment, which was removed. The remaining abdominal viscera were normal and there was no other evidence of hemorrhage. The partial liver resection presented subcapsular hemorrhage with small parenchymal hemorrhage. Histopathological examination also revealed focal areas of ischemic centrilobular necrosis. The patient died of multiple organ system failure 21 days after admission. Copyright © 2002 By PJD Publications Limited.

A fatal attack caused by a lowland tapir (Tapirus terrestris) in Southeastern Brazil

A 55-year-old man was attacked by a Brazilian tapir (Tapirus terrestris) after surprising and stabbing the animal in his corn plantation. The victim received deep bites in the thighs, neck, and cervical areas, resulting in severe hemorrhage and death. This is the first report of a tapir incident resulting in death and is of interest because of the severity of the contusions and lacerations caused by the provoked animal.

Clinical and cardiovascular alterations produced by scorpion envenomation in dogs

Scorpionism is a common problem that occurs in tropical and subtropical countries and assumes great medical-sanitary importance due to its fatal effect on sensitive individuals, being able to lead children and aged people to death. The envenomation lethal potential is responsible for the serious cardiopulmonary alterations the scorpion toxin produces in its victims. The present research evaluated the effects of Tityus serrulatus venom on dogs, using two distinct doses: a dose that simulates natural envenomation (0.4 mg/total dose), and an experimental dose (0.25 mg/kg). General clinical signs were observed at different moments after envenomation, and specific data related to the cardiopulmonary system were evaluated by systemic arterial pressure measurement, CK-MB enzymatic activity dosage, and radiographic, electrocardiographic and echocardiographic examinations. Results demonstrated that the scorpion venom, in experimental doses, was able to cause acute and reversible cardiac injury in few days, and, in the dose that simulated natural accident, it produced clinical signs of light envenomation, such as local pain, hyperesthesia, sialorrhea, vomiting, diarrhea, sneeze and prostration.

In vitro cytotoxic and non-genotoxic effects of gutta-percha solvents on mouse lymphoma cells by single cell gel (comet) assay

Chloroform and eucalyptol are widely used in clinical dentistry as gutta-percha solvents. However, these compounds may represent a hazard to human health, especially by causing injury to genetic apparatus and/or inducing cellular death. In this study, the genotoxic and cytotoxic potentials associated with exposure to chloroform and eucalyptol were assessed on mouse lymphoma cells in vitro by the single cell gel (comet) assay and trypan blue exclusion test, respectively. Both gutta-percha solvents proved to be cytotoxic at the same levels in concentrations of 2.5, 5 and 10 μL/mL (p<0.05). On the other hand, neither of the solvents induced DNA breakage. Taken together, these results suggest that although both tested compounds (chloroform and eucalyptol) are strong cytotoxicants, it seems that they are not likely to increase the level of DNA damage on mammalian cells.