The role of the placenta in the vertical transmission of HIV-1

A transmissão vertical (TV) consiste na principal forma de infecção pelo HIV-1 em menores de 13 anos e estimativas apontam que em 25% dos casos a transmissão tenha ocorrido intraútero. Nessas circunstâncias, o vírus de alguma forma ultrapassa a membrana placentária e chega ao sangue fetal. Esta revisão tem como objetivo realizar uma breve descrição sobre os mecanismos presentes na placenta humana que são capazes de gerar susceptibilidade ou proteção à TV do HIV-1. As células placentárias produzem um enorme grupo de citocinas, quimiocinas, hormônios e receptores que podem contribuir com o desfecho da transmissão do vírus ao concepto. Além disso, a capacidade do vírus de infectar as células placentárias também pode contribuir com a sua transmissão. Entretanto, o mecanismo pelo qual o vírus é capaz de sobrepujar a membrana placentária e as consequências dessa infecção no tecido placentário não estão totalmente elucidados. Dessa forma, novas pesquisas nessa área poderão contribuir com o desenvolvimento de estratégias profiláticas eficazes para redução da TV do HIV-1Vertical transmission (VT) is the main form of infection by HIV-1 in children under 13 years and estimates show that in 25% of cases intrauterine transmission has occurred. Under these circumstances, the virus somehow overcomes the placental membrane and reaches the fetal blood. This review aims to conduct a brief description of the mechanisms present in human placenta that are capable of generating susceptibility or resistance to VT of HIV-1. Placental cells produces a huge group of cytokines, chemokines, hormones and receptors that may contribute to the outcome of virus transmission to the fetus. Moreover, the ability of the virus to infect placental cells can also contribute to its transmission. However, the mechanism by which the virus is able to overcome the placental tissue is not fully elucidated. Thus, further research in this area may contribute to the development of effective preventive strategies to reduce the VT of HIV-

The Recognition of N-Glycans by the Lectin ArtinM Mediates Cell Death of a Human Myeloid Leukemia Cell Line

ArtinM, a d-mannose-binding lectin from Artocarpus heterophyllus (jackfruit), interacts with N-glycosylated receptors on the surface of several cells of hematopoietic origin, triggering cell migration, degranulation, and cytokine release. Because malignant transformation is often associated with altered expression of cell surface glycans, we evaluated the interaction of ArtinM with human myelocytic leukemia cells and investigated cellular responses to lectin binding. The intensity of ArtinM binding varied across 3 leukemia cell lines: NB4>K562>U937. The binding, which was directly related to cell growth suppression, was inhibited in the presence of Manα1-3(Manα1-6)Manβ1, and was reverted in underglycosylated NB4 cells. ArtinM interaction with NB4 cells induced cell death (IC50 = 10 µg/mL), as indicated by cell surface exposure of phosphatidylserine and disruption of mitochondrial membrane potential unassociated with caspase activation or DNA fragmentation. Moreover, ArtinM treatment of NB4 cells strongly induced reactive oxygen species generation and autophagy, as indicated by the detection of acidic vesicular organelles in the treated cells. NB4 cell death was attributed to ArtinM recognition of the trimannosyl core of N-glycans containing a ß1,6-GlcNAc branch linked to α1,6-mannose. This modification correlated with higher levels of N-acetylglucosaminyltransferase V transcripts in NB4 cells than in K562 or U937 cells. Our results provide new insights into the potential of N-glycans containing a β1,6-GlcNAc branch linked to α1,6-mannose as a novel target for anti-leukemia treatment

Geology and taphonomy of the base of the Taquaral Member, Irati Formation (Permian, Paraná Basin), Brazil

The taphonomy of Early Permian vertebrates from a sandy facies at the base of the Taquaral Member, Irati Formation, was surveyed in order to acquire data for the interpretation of the sedimentary processes and paleoenvironment of deposition. Six outcrops from the Rio Claro municipality and surrounding areas, from the Brazilian State of São Paulo, were investigated. The vertebrate groups are Chondrichthyes (Xenacanthiformes, Ctenacanthiformes and Petalodontiformes), Osteichthyes (Actinopterygii and Sarcopterygii) and Tetrapodomorpha. They occur as loose teeth, scales, spines and bone remains. The sandy facies is characterized by fining upward deposition. The coarser sandstone immediately above the underlying Tatuí Formation is rich in Chondrichthyes. However, the fine sandstone above, immediately beneath the silty shale facies, is devoid of Chondrichthyes, though Osteichthyes scales, teeth and bones were present. The taphonomy is important for inferring sedimentary processes and then the paleoenvironments. The poor sorting of the sandstone and the presence of fossils that are mostly abraded or worn are indicative of a high energy environment. In contrast, the presence of fossils in a good state of preservation, some without abrasion and breakages are indicative of only limited transport. Differences of fossil spatial density, numbers of specimens and taxa may be explained by the dynamics of deposition, from details of the palaeoenvironment can be obtained

The first microfossil record of ichthyofauna from the Naujoji Akmenė Formation (Lopingian), Karpėnai Quarry, northern Lithuania

The assemblage of rare fish microremains of chondrichthyans and actinopterygians from Upper Permian deposits in Karpénai Quarry in northern Lithuania is described in detail for the first time. The deposits are characterized as reflecting a rapid phase of deposition of the Zechstein Limestone, interpreted as on a shallow shelf above storm-wave base in a proximal part of the Polish-Lithuanian Zechstein Basin. The actinopterygian microremains are represented by various teeth and a few scales from mostly palaeonisciforms and pycnodontiforms. The chondrichthyans are represented by various eusela- chian-type scales and a tooth of ?Helodus sp. The low abundance and low species diversity of the fossil assemblages studied may be due to arid palaeoenvironments that caused locally restricted conditions at this palaeogeographical location

Superior oblique muscle amyloidosis mimicking myositis

A 47-year-old man presented with complaints of progressive diplopia in downgaze and a painful firm mass on the left medial superior canthus. On examination, there was marked hyperemia of the superior bulbar conjunctiva of the left eye. Systemic examination revealed erythematous papules on his trunk and pulmonary infiltrates. CT of the orbits revealed a fusiform enlargement of the left superior oblique muscle and diffuse infiltration of the left temporal region. Biopsy of the left superior oblique muscle and temporal muscle disclosed Congo red deposits that show apple-green birefringence under polarized light. A comprehensive systemic investigation failed to show any disease that could explain the amyloid deposits. The patient was then diagnosed as having primary systemic amyloidosis. We think that this case highlights the necessity of a biopsy in any atypical extraocular muscle enlargement before a diagnosis of myositis