Active and exo-site inhibition of human factor Xa: Structure of des-Gla factor Xa inhibited by NAP5, a potent nematode anticoagulant protein from Ancylostoma caninum

Hookworms are hematophagous nematodes capable of growth, development and subsistence in living host systems such as humans and other mammals. Approximately one billion, or one in six, people worldwide are infected by hookworms causing gastrointestinal blood loss and iron deficiency anemia. The hematophagous hookworm Ancylostoma caninum produces a family of small, disulfide-linked protein anticoagulants (75-84 amino acid residues). One of these nematode anticoagulant proteins, NAP5, inhibits the amidolytic activity of factor Xa (fXa) with K-i = 43 pM, and is the most potent natural fXa inhibitor identified thus far. The crystal structure of NAP5 bound at the active site of gamma-carboxyglutamic acid domainless factor Xa (des-fXa) has been determined at 3.1 angstrom resolution, which indicates that Asp189 (fXa, S1 subsite) binds to Arg40 (NAP5, P1 site) in a mode similar to that of the BPTI/trypsin interaction. However, the hydroxyl group of Ser39 of NAP5 additionally forms a hydrogen bond (2.5 angstrom) with His57 NE2 of the catalytic triad, replacing the hydrogen bond of Ser195 OG to the latter in the native structure, resulting in an interaction that has not been observed before. Furthermore, the C-terminal extension of NAP5 surprisingly interacts with the fXa exosite of a symmetry-equivalent molecule forming a short intermolecular beta-strand as observed in the structure of the NAPc2/fXa complex. This indicates that NAP5 can bind to fXa at the active site, or the exosite, and to fX at the exosite. However, unlike NAPc2, NAP5 does not inhibit fVIIa of the fVIIa/TF complex. (c) 2007 Elsevier Ltd. All rights reserved.

Equine infectios anemia of traction equids in the Cuiaba Districty, MT, Brazil

The present study it had for objective to search the AIE in equids traction of the city of Cuiaba, of which if it extracted an inquiry epidemiologist and a sampling of blood serum of 113 animals (110 equines and 3 mules) that they transited for the public ways. The sampling of the animals was random how much to the age (of 8 months the 20 years) and sex of the animals where 67 (60.9%) were of females and 46 (41.8%), of males, with a average of 22 working hours per week. The samples of blood had been analyzed by means of the technique of AGID test. The results of the blood tests had indicated that of the 110 examined samples of blood serum of the equines, thirteen (11.8%) were positive, being seven of female (10.4% of the total of females) and 6 males (13.0% of the total of males), all no symptoms animals and the age of the positive animals was concentrated in the band of 6 10 years, representing 84.6% (11 animals). The results of the blood tests had also indicated that of three mules analyzed, 1 (33.3%) was positive.

A study of the hydrolysis pathway in oxalic acid catalyzed reacting TMOS-water mixtures under ultrasound stimulation

The hydrolysis of TMOS in oxalic acid catalyzed reacting TMOS-water mixtures, under ultrasound stimulation, was studied by fitting a simplified dissolution and reaction modeling for samples, the hydrolysis rate of which had been measured in a previous work. The reaction pathway represented in a ternary diagram shows a heterogeneous step for the reaction which gradually progresses until complete homogenization of the system. Besides the water dissolved due to the homogenizing effect of the alcohol, ultrasound maintains a virtual and additional dissolution of water located at the interface between the TMOS and water during the heterogeneous step of the reaction. The mean radius of the heterogeneity represented by water dispersed in TMOS was evaluated as around 150 Angstrom. The oxalic acid concentration accordingly increases the hydrolysis rate constant but its fundamental role on the solubility of water in TMOS could not unequivocally be established.

Downregulation of nuclear factor-kappa B (NF-kappa B) pathway by silibinin in human monocytes challenged with Paracoccidioides brasiliensis

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

Anemia em crianças menores de dois anos atendidas nas unidades básicas de saúde no Estado de São Paulo, Brasil

The present study sought to determine the prevalence of anemia in 2,992 children, aged between 6 and 23 months, who voluntarily attended 160 Basis Health Care Units, located in 63 cities of the 5 Regional Health Coordinating areas of the State of S. Paulo, Brazil. Blood samples were collected by venous puncture and hemoglobin was measured by the cianometahemoglobin method. The WHO criteria for the diagnosis of anemia (Hb < 11.0 g/dl) were used: 59.1% of the children were shown to be anemic, with prevalence varying from 47.8% to 68.7% in the 5 RHCs. RHC 1, which comprises the Greater S. Paulo Region, presented a prevalence of anemia significantly lower than the other 4 RHCs, which cover the rest of the State. Hemoglobin levels 9.5 g/dl were found in 25.1% of the children. Anemia was more frequent in male children in male children, in those born, with a weight of less than 3,000 gr, in those who were breastfed for less than 2 months and in those that who presented some degree of energy deficient proteic malnutrition, according to Gomez's criteria. This is the first of a series of 4 articles whose purpose is the determining the prevalence of anemia in the State of S. Paulo and of testing the intervention alternatives with a view to curtailing the incidence of this pathology which today is the most prevalent nutritional disturbance in the world.

Fortificação do leite fluido na prevenção e tratamento da anemia carencial ferropriva em crianças menores de 4 anos

The effectiveness of the use of chelate aminoacid iron fortified fluid milk in the treatment of iron deficiency in children under four years of age was studied. The 269 children included in this trial received 1 liter/day of fluid milk fortified with 3 mg of chelate aminoacid iron and were evaluated at six monthly intervals. At the beginning of the study 62.3% of the children presented anemia. After 6 months, this percentage had decreased to 41.8% and at the end of one year to 26.4%. The greatest decreases occurred in the groups comprising the subjects who were of 12 to 23 months of age and those under one year of age. Among the children who presented initial hemoglobin levels under 9.5 g/ dl, 59.3% were free of anemia after one year of follow-up. Of those presenting initial hemoglobin levels between 9.5 and 10.9 g/dl, 66.7% recovered from their anemia. There was also greater hematological improvement in the children that ingested over 750 ml/day of fortified milk in those families that did not share the supply of supplement among their other members and in those families that had only one child under five years of age. These findings led to the conclusion that the fortification of fluid milk is a viable and effective method for the treatment of iron deficiency in pre-school children.

Interferentes eritrocitários e ambientais na anemia falciforme

Erythrocytes and environmental interferences on sickle cell anaemia Sickle cell anaemia runs na extremely variable clinical course At one end of spectrum, it is characterized by a crippling haemolitic anaemia, interspersed with severe exacerbations, or crises, yet it may be an extremely mild disorder, which is found only by chance on rotine haematological examination. The reasons are only partly understood for these remarkable differences in phenotypic expression of what appears to be the same genetic defect: they include the level of Hb Fetal, coinheritance of the alpha thalassaemia and of other genetic variantsthat has influence as genetic modulation in sickle cell anaemia. However, other genetics abnormalities of erythrocytes: G-6PD deficiency, spherocytosis and deficiencies of anti-oxidant enzymes(SOD, GPx and Catalase) probably interfereon the clinical course of sickle cell anaemia. The haplotypes of the chromosome (Bantu, Benin, Camaroon and Arab-Indian) bearing the sickle gene is associated with assorted haematological and clinical features that are likely, at least in part, to be mediated throgh effects on Hb Fetal concentration. Beyond these factors characterizes as erythrocytes interferents, there are the environmental interferents. Between environmental interferents become detached the socio-economic and cultural situation of each patient. These aspects have influence on the life of affected individuals including social interactions, family relations, peer interaction, intimate relationships, education, enployment, violence, spiritual attitudes and navigating complexities of the health care system, providers and their ancillary functions. As a result of this article it is proposed a protocol of laboratorial management of sickle cell syndrome with detach to sickle cell anaemia.

Testicular ultrastructure and morphology of the seminal pathway in Prochilodus scrofa

The seminiferous tubules of Prochilodus scrofa present a coiled morphological arrangement with intertubular anastomoses and unrestricted spermatogonial distribution. The structural pattern of the seminiferous tubules is cystic, with cysts formed by cytoplasmic prolongations of Sertoli cells. Inside the cysts are observed different types of germ cells. The seminiferous tubules open individually on the ventral surface of the main testicular duct present in each testis. Each main testicular duct prolongs as a spermatic duct, fusing with the spermatic duct of the opposite side to form the common spermatic duct which opens into the urogenital papilla. The mature sperm cysts break and extravasate their content into the lumen of the seminiferous tubules from which the seminal fluid and the spermatozoa penetrate the main testicular duct, the spermatic duct and the common spermatic duct for semen ejaculation.

A complexa fisiopatologia dos episódios vasooclusivos na anemia falciforme

Hemolytic anemia and vasoocclusion are the cardinal clinical features of sickle cell anemia. Vasoocclusion is a complex process involving not only the polymerization of deoxygenated sickle hemoglobin tetramers, but also interactions between sickle erythrocytes, vascular endothelium, platelets, leukocytes, and plasma proteins. The increased adherence of sickle erythrocytes to endothelium has been implicated as an early step in vasoocclusion. Other researchers have focused on leukocytes and platelets which might also contribute to disturbed blood flow. Microvascular occlusion results in acute painful crises, whereas macrovascular occlusion seems to be the cause of organ failure. The anemia results from the markedly shortened circulatory survival of sickle erythrocytes, together with a limited erythropoietic response. The erythropoiesis increases intensively, but it is not enough to balance the increased rate of erythrocytes destruction to maintain normal levels of total erythrocytes and hemoglobin concentrations; mainly by the low oxygen affinity of hemoglobin S and increased 2,3-Diphosphoglycerate. It is very difficult to separate processes leading to anemia or to vasoocclusion. Understanding the involvement of multiple blood componentes in vasoocclusion may elucidate the clinical manifestations and complications of sickle cell anemia, and may give new insights into the preventive and curative therapy.

Naso-orbicular tissue necrosis by Streptococcus parasanguis in a patient with Fanconi anemia: Clinical and laboratory aspects

Fanconi anemia (FA) is a rare autosomal recessive disorder, characterized by pancytopenia and progressive hypoplasia of the bone marrow. A 23-year-old woman with FA showed severe pancytopenia and developed an abscess on the infraorbicular region on the right side of the face that progressed to phlegmon and caused tissue necrosis of the nostrils, nasal septum, nasal fossa, and posterior orbital region. Laboratory examination showed Streptococcus parasanguis as the etiologic agent of the phlegmon. Supportive treatment was recommended due to donor incompatibility for bone marrow transplant. The intraoral examination showed spontaneous gingival bleeding, edema of the interdental papillae, hematomas on the superior and inferior lips, bacterial and fungal infections, and adequate oral hygiene. The patient was treated with the administration of an antibiotic (imipenem), an antifungal (amphotericin B), and mouth washing with antiseptic solutions. Periodontal prophylaxis and orientation to and control of oral hygiene and diet were also used during the remission period. For functional and esthetic rehabilitation of the alar regions and nasal dorsum, an acrylic resin nasal prosthesis was made, supported by a spectacle frame.

The post-transcriptional gene silencing pathway in Eucalyptus

Post-transcriptional gene silencing (PTGS) is a conserved surveillance mechanism that identifies and cleaves double-stranded RNA molecules and their cellular cognate transcripts. The RNA silencing response is actually used as a powerful technique (named RNA interference) for potent and specific inhibition of gene expression in several organisms. To identify gene products in Eucalyptus sharing similarities with enzymes involved in the PTGS pathway, we queried the expressed sequence tag database of the Brazilian Eucalyptus Genome Sequence Project Consortium (FORESTs) with the amino acid sequences of known PTGS-related proteins. Among twenty-six prospected genes, our search detected fifteen assembled sequences encoding products presenting high level of similarity (E value < 10 -40) to proteins involved in PTGS in plants and other organisms. We conclude that most of the genes known to be involved in the PTGS pathway are represented in the FORESTs database. Copyright by the Brazilian Society of Genetics.