Clinical and biochemical response to neridronate treatment in a patient with osteoporosis-pseudoglioma syndrome (OPPG).

Osteoporosis-pseudoglioma syndrome (OPPG) is a rare autosomal recessive syndrome characterized by juvenile-onset osteoporosis and ocular abnormalities due to a low-density lipoprotein receptor-related protein 5 (LRP5) gene mutation. Treatment with bisphosphonates, particularly with pamidronate and risedronate, has been reported to be of some efficacy in this condition. We report on a patient with OPPG due to an LRP5 gene mutation, who showed an encouraging response after a 36-month period of neridronate therapy. We report a case of a patient treated with bisphosphonates. Bisphosphonates should be administered in OPPG patients as a first-line therapy during early childhood.

Serum creatine kinase isoenzymes in children with osteogenesis imperfecta.

This study evaluates serum creatine kinase isoenzyme activity in children with osteogenesis imperfecta to determine its usefulness as a biochemical marker during treatment with bisphosphonate. The changes of creatine kinase (CK) isoenzyme activity during and after discontinuation therapy were observed. These results could be useful in addressing over-treatment risk prevention. INTRODUCTION: The brain isoenzyme of creatine kinase (CKbb) is highly expressed in mature osteoclasts during osteoclastogenesis, thus plays an important role in bone resorption. We previously identified high serum CKbb levels in 18 children with osteogenesis imperfect (OI) type 1 treated for 1 year with bisphosphonate (neridronate). In the present study, serum CK isoenzymes were evaluated in the same children with continuous versus discontinued neridronate treatment over a further 2-year follow-up period. METHODS: This study included 18 children with OI type 1, 12 with continued (group A) and 6 with ceased (group B) neridronate treatment. Auxological data, serum biochemical markers of bone metabolism, bone mineral density z-score, and serum total CK and isoenzyme activities were determined in both groups. RESULTS: Serum CKbb was progressively and significantly increased in group A (p < 0.004) but rapidly decreased to undetectable levels in group B. In both groups, the cardiac muscle creatine kinase isoenzyme (CKmb) showed a marked decrease, while serum C-terminal telopeptide (CTx) levels were almost unchanged. CONCLUSIONS: This study provides evidence of the cumulative effect of neridronate administration in increasing serum CKbb levels and the reversible effect after its discontinuation. This approach could be employed for verifying the usefulness of serum CKbb as a biochemical marker in patients receiving prolonged bisphosphonate treatment. Moreover, the decreased serum CKmb levels suggest a systemic effect of these drugs.

Reliability of vertebral fractures assessment (VFA) in children with osteogenesis imperfecta.

The aim of this study is to evaluate the diagnostic accuracy of vertebral fractures assessment (VFA) in comparison with conventional radiography in identifying vertebral fractures in children and adolescents affected by OI. On 58 patients (33 males, 25 females; age range 1-18 years; 41 children and 17 adolescents) with osteogenesis imperfecta (OI type I, n = 44, OI type III, n = 4; OI type IV, n = 10), lateral spine images by radiographs and by dual-energy X-ray absorptiometry (DXA) were acquired. For vertebral fracture diagnosis, plain radiographs were used as "gold standard" and VFA and morphometric X-ray absorptiometry (MXA) were performed. The visualized vertebrae were 738 (97.9%) by radiographs and 685 (90.9%) by DXA of a total of 754 vertebrae from T4 to L4. VFA and MXA identified, respectively, 129 (74%) and 116 (66%) of the 175 vertebral fractures detected by radiographs. Radiographs identified 36 patients with vertebral fractures, VFA 35 and MXA 41 (6 false positives). On a per vertebra basis, radiographs and VFA had elevated agreement (93.9%; k score 0.81, 95% CI 0.76-0.86), that resulted slightly lower for MXA (90.6%; k score 0.72, 95% CI 0.65-0.78). VFA and MXA demonstrated high sensitivity (95.6 and 94.1 %, respectively) while specificity was 100% for VFA and 90.6% for MXA on a per patient basis; the agreement was excellent for VFA (98.3%; k score 0.96, 95% CI 0.89-1.03) and good for MXA (87.9%; k score 0.73, 95% CI 0.55-0.91). The diagnostic performance parameters resulted better for VFA (sensitivity 95.6%; specificity 100%; PPV 100%; NPV 97.2%), than for MXA (sensitivity 94.1%; specificity 85.4%; PPV 72.7%; NPV 97.2%). The results of our study demonstrate the reliability of VFA for diagnosis of vertebral fractures in children with OI suggesting its use as a more safe and practical alternative to conventional radiography.

Spinal elastofibroma: a case report.

Elastofibroma is a benign fibroproliferative tumor of unknown origin and pathogenesis. It usually appears in the subscapular or infrascapular area. It is extremely rare in the spinal area, and it is most common in middle-aged women. In most cases, it is asymptomatic. Its diagnosis is based on nuclear MRI, where it presents a homogeneous lesion, similar to the skeletal muscle, hyperintense in T1-weighted sequences and hypointense in T2-weighted sequences. This finding is confirmed with anatomical pathology tests, where it appears as a nonencapsulated lesion made up of wide collagen bands from connective tissue mixed with fat and muscle tissue. The treatment of choice is surgical removal of the lesion. We present a clinical case of elastofibroma, a benign and rare pathology with few described cases in the literature, in a patient with a previous dorsal lesion.

[Publications on spine surgery in Mexico: a bibliometric study]. / Estudio bibliométrico de las publicaciones en cirugía de columna en México.

INTRODUCTION: bibliometric analysis is a useful way of assessing the past, present and future publications related to a given area in a qualitative and quantitative way. OBJECTIVE: to determine characteristics of national authors productivity in the field of spine surgery research across the time. MATERIAL AND METHODS: an online research was performed using the Elsevier´s database Scopus in October, 2021. All studies were assessed for the following parameters: year, title, access, language, journal, type of article, focus of research, objective of research, cites, authors and institutions. RESULTS: a total of 404 publications were identified between 1973 and 2021. Between 1991-2000 decade to 2011-2021 decade the number of published articles tended to increase by 68.28 times. The largest number of articles was from South-Central Region (66.16%), followed by Western (15.03%) and Northwest (8.27%). The highest h-index was found for USA journals (102). The highest number of articles was published in Coluna/Columna (15.53%), followed by Cirugía y Cirujanos (10.52%) and Acta Ortopédica Mexicana (8.52%). Instituto Nacional de Rehabilitación published the largest number of articles (17.57%), followed by Centro Médico Nacional de Occidente del IMSS (6.67%) and Centro Médico ABC (5.44%). CONCLUSIONS: the number of articles published in the field of spine surgery in Mexico has increased rapidly in the past 15 years. In terms of quality, publications written in English are the most cited. The geographical distribution of research in Mexico is centralized, the largest number of publications was from South-Central Region of Mexico.

INTRODUCCIÓN: el análisis bi­bliométrico es una forma útil de evaluar el pasado, el pre­sente y el futuro de las publicaciones relacionadas con un área determinada de forma cualitativa y cuantitativa. OBJETIVO: determinar las características de la productividad nacional en investigación escrita por autores mexicanos en el campo de cirugía de columna a través del tiempo. MATERIAL Y MÉTODOS: se realizó una búsqueda exhaustiva en línea en Octubre de 2021 utilizando la base de datos Scopus desarrollada por Elsevier. La información de las publicaciones recolectadas fue la siguiente: año, título, acceso, idioma, revista, tipo de artículo, tema, objetivo, citas, autores e instituciones de afiliación. RESULTADOS: se identificó un total de 404 publicaciones entre 1973 y 2021. El número de publicaciones entre la década 1991-2000 y 2011-2021 incrementó 68.28 veces. La mayoría de las publicaciones se realizaron en instituciones de la región centro-sur de México (66.16%), seguida de la región occidente (15.03%) y noreste (8.27%). El índice H más alto encontrado fue de revistas de origen estadounidense (102). La mayor parte de las publicaciones se realizó en la revista Coluna/Columna (15.53%), seguida de Cirugía y Cirujanos (10.52%) y de Acta Ortopédica Mexicana (8.52%). La institución con la más alta productividad fue el Instituto Nacional de Rehabilitación "Luis Guillermo Ibarra Ibarra" (17.57%), seguida del Centro Médico Nacional de Occidente del IMSS (6.67%) y del Centro Médico ABC (5.44%). CONCLUSIONES: el número de artículos publicados en el campo de cirugía de columna ha incrementado rápidamente en los últimos 15 años. Las publicaciones escritas en inglés son las más citadas. La distribución geográfica de la investigación en este campo en México está centralizada, realizándose la mayor parte de las publicaciones en la región centro-sur del país (66.16%).

Vertebral fracture assessment (VFA) for monitoring vertebral reshaping in children and adolescents with osteogenesis imperfecta treated with intravenous neridronate.

PURPOSE: The study was aimed at monitoring vertebral bodies changes with the use of Vertebral Fracture Assessment (VFA) in children and adolescents affected by osteogenesis imperfecta (OI) during treatment with intravenous neridronate. METHODS: 60 children and adolescents (35 males and 25 females; age 1-16 years) with OI type I, III and IV were included in the study. Intravenous neridronate was administered at the dose of 2 mg/kg every 3 months in all patients. Lumbar spine (LS) bone mineral density (BMD) and VFA by dual X-ray absorptiometry (DXA) were assessed every 6 months up to 24 months during treatment. VFA with vertebral morphometry (MXA) was used to calculate the three indices of vertebral deformity: wedging, concavity and crushing. Serum calcium, phosphate, parathyroid hormone (PTH), 25-hydroxy-vitamin D [25(OH)D], total alkaline phosphatase (ALP), bone alkaline phosphatase (BALP) and urinary C-terminal telopeptide of type 1 collagen (CTx) were measured at any time point. RESULTS: Mean LS BMD values significantly increased at 24 months compared to baseline (p < 0.0001); the corresponding Z-score values were -1.28 ± 1.23 at 24 months vs -2.46 ± 1.25 at baseline; corresponding mean Bone Mineral Apparent Density (BMAD) values were 0.335 ± 0.206 vs 0.464 ± 0.216. Mean serum levels of ALP, BALP and CTx significantly decreased from baseline to 24 months. By MXA, we observed a significant 19.1% reduction of the mean wedging index of vertebral reshaping at 12 months, and 38.4% at 24 months (p < 0.0001) and of the mean concavity index (16.3% at 12 months and 35.9% at 24 months; p < 0.0001). Vertebral reshaping was achieved for 66/88 (75%) wedge fractures and 59/70 (84%) concave fractures, but there were 4 incident mild fractures. Finally, VF rate was reduced at 24 months compared to baseline: 37/710 (5.2%) vs 158/710 (22.2%). CONCLUSION: Our study demonstrates the utility of VFA as a safe and alternative methodology in the follow-up of children and adolescents with OI.

Ultrastructure study of skin fibroblasts in patients with Ehlers-Danlos Syndrome (EDS): preliminary results.

AIM OF THE STUDY: To investigate, in vivo and in vitro, the fibroblast-to-myofibroblast transition in patients with hypermobile Ehlers-Danlos Syndrome (EDS). To analyze the dermis of patients with classical form of EDS (cEDS) and with hEDS, to identify qualitative and/or quantitative differences in ECM component and ultrastructural changes in collagen. MATERIALS AND METHODS: Seven subjects, aged over 18, two with cEDS and five with hEDS underwent two skin biopsy. One sample was prepared for transmission electron microscopy (TEM), the other for immunofluorescence. The diameter of collagen fibers was measured with TEM. Fibrils were analyzed in four patients: the two with cEDS and two with hEDS. For each patient, the diameter of n=250 collagen fibrils was measured. αSMA was used as specific marker for myofibroblast to highlight their presence in vivo in the skin of patients with hEDS. RESULT: IF observation could not assess an increased expression of αSMA in hEDS patients, which showed no statistical difference compared to classic form patients. The major result from the analysis of TEM images is the clear difference in ECM composition between the two forms of EDS: ECM in hEDS is optically more dense and more prominently composed of elastic fibers. CONCLUSION: Our study provides the following important evidence: 1) the absence in vivo of dermal fibroblasts in patients with hEDS, demonstrated by αSMA negativity; 2) the presence of statistically significant changes in the diameter of collagen fibrils between the classic and the hypermobile forms.

Identifying molecular markers associated with classification of genotypes by External Logistic Biplots.

UNLABELLED: For characterization of genetic diversity in genotypes several molecular techniques, usually resulting in a binary data matrix, have been used. Despite the fact that in Cluster Analysis (CA) and Principal Coordinates Analysis (PCoA) the interpretation of the variables responsible for grouping is not straightforward, these methods are commonly used to classify genotypes using DNA molecular markers. In this article, we present a novel algorithm that uses a combination of PCoA, CA and Logistic Regression (LR), as a better way to interpret the variables (alleles or bands) associated to the classification of genotypes. The combination of three standard techniques with some new ideas about the geometry of the procedures, allows constructing an External Logistic Biplot (ELB) that helps in the interpretation of the variables responsible for the classification or ordination. An application of the method to study the genetic diversity of four populations from Africa, Asia and Europe, using the HapMap data is included. AVAILABILITY: The Matlab code for implementing the methods may be obtained from the web site: http://biplot.usal.es.

National prevalence of nosocomial infections. Cuba 2004.

In 1983 Cuba instituted its first Nosocomial Infection (NI) Control and Prevention National Program with a continuous surveillance system. We undertook the first NI prevalence study in 1997 in an attempt to compare our national findings with international results. A second prevalence study with a randomised design was undertaken between 24 and 29 May 2004. The overall rate of NI was 7.3% (284/4240; 95% CI: 5.9-7.4), and 6.7% of patients were found to have at least one NI. The highest rates were found in intensive care, intermediate care and burn units. The most frequent NI was surgical site infection, whereas the number of urinary tract infections remained low. Microbiological culture was obtained in nearly 53% of infections; Staphylococcus aureus and Pseudomonas spp. were the most commonly isolated pathogens. Cephalosporins and aminoglycosides were the antibiotics most often used in the treatment of NIs. The risk factors for NIs found in the Cuban studies were similar to international reports.

Histone deacetylase inhibitors: mechanism of action and therapeutic use in cancer.

Histone deacetylases (HDACs) remove the acetyl groups of lysine residues of histone tails leading to chromatin compaction and transcriptional repression. In addition, HDACs can also influence transcription-independent events such as mitosis or deoxyribonucleic acid (DNA) repair and deacetylate nonhistone proteins involved in cell proliferation and death, altering their function. Histone deacetylase inhibitors (HDACi) constitute a promising treatment for cancer therapy due to their low toxicity. HDACi have been shown to induce differentiation, cell-cycle arrest, and apoptosis and to inhibit migration, invasion, and angiogenesis in many cancer cell lines. In addition, these compounds inhibit tumor growth in animal models and show antitumor activity in patients. HDACi alone and in combination with a variety of anticancer drugs are being tested in clinical trials, showing significant anticancer activity both in hematological and solid tumors. SAHA (vorinostat, Zolinza) was the first HDACi approved by the US Food and Drug Administration to enter the clinical oncology market for treating cutaneous T-cell lymphoma (CTCL) and is being tested for other malignancies.

The geographic mosaic of Ecuadorian Y-chromosome ancestry.

Ecuadorians originated from a complex mixture of Native American indigenous people with Europeans and Africans. We analyzed Y-chromosome STRs (Y-STRs) in a sample of 415 Ecuadorians (145 using the AmpFlSTR® Yfiler™ system [Life Technologies, USA] and 270 using the PowerPlex®Y23 system [Promega Corp., USA]; hereafter Yfiler and PPY23, respectively) representing three main ecological continental regions of the country, namely Amazon rainforest, Andes, and Pacific coast. Diversity values are high in the three regions, and the PPY23 exhibits higher discrimination power than the Yfiler set. While summary statistics, AMOVA, and RST distances show low to moderate levels of population stratification, inferred ancestry derived from Y-STRs reveal clear patterns of geographic variation. The major ancestry in Ecuadorian males is European (61%), followed by an important Native American component (34%); whereas the African ancestry (5%) is mainly concentrated in the Northwest corner of the country. We conclude that classical procedures for measuring population stratification do not have the desirable sensitivity. Statistical inference of ancestry from Y-STRS is a satisfactory alternative for revealing patterns of spatial variation that would pass unnoticed when using popular statistical summary indices.

Absence of severe recurrent infections in glycogen storage disease type Ib with neutropenia and neutrophil dysfunction.

We describe a 10-year-old boy with glycogen storage disease type Ib (GSD Ib) with neutropenia and neutrophil dysfunction who never suffered from severe recurrent infections. Lymphocyte subpopulations and assay of intracellular cytokines (IL-2, IL-4 and IFN-gamma) showed a pattern of lymphocyte activation suggesting a shift of T(H)1/T(H)2 balance towards a T(H)1 response. This is the first report of GSD Ib without severe recurrent infections in spite of neutropenia and neutrophil dysfunction.

Evaluation of the equations to estimate the glomerular filtration rate in kidney transplant recipients.

This study assessed the performance of three methods for estimating glomerular filtration rate (GFR) in kidney transplant patients: the Cockcroft-Gault formula, the modification of diet in renal disease (MDRD) method, and the four-variable modification of diet in renal disease (four-variable MDRD), both as an overall estimate and as related to clinical disease stage. We analyzed data from 136 renal transplant patients including 84 men in an overall age range of 28 to 76 years. Patients were categorized into three groups according to GFR as determined by the arithmetical mean of the last four creatinine clearance determinations after outlying values had been excluded: group 1, estimated GFR of <30 mL/min (n = 26); group 2, estimated GFR of 30 to 60 mL/min (n = 63);, and group 3, estimated GFR >60 mL/min (n = 33). Fourteen patients were excluded from the analysis because of a high variability between their creatinine clearance determinations. Estimated GFRs using the Cockroft-Gault, MDRD, and four-variable MDRD formulae were compared with GFRs as measured by creatinine clearance. Statistically significant correlations were observed for all three formulae for the overall series and for individual clinical groups. Hence, we concluded that all equations had a similar capacity to predict the GFR. In addition, because of the clear, significant correlation between the MDRD and the four-variable MDRD (r = .992; P = .0001), we believe that the four-variable MDRD can substitute for the MDRD for clinical purposes.

Pursuit-and-Evasion Reaction-Diffusion Waves in Microreactors with Tailored Geometry.

Out-of-equilibrium chemical systems may self-organize into structures displaying spatiotemporal order, such as traveling waves and Turing patterns. Because of its predictable chemistry, DNA has recently appeared as an interesting candidate to engineer these spatiotemporal structures. However, in addition to the intrinsic chemical parameters, initial and boundary conditions have a major impact on the final structure. Here we take advantage of microfluidics to design controlled reactors and investigate pursuit-and-evasion chemical waves generated by a DNA-based reaction network with Predator-Prey dynamics. We first propose two complementary microfabrication strategies to either control the initial condition or the two-dimensional geometry of the reactor where the waves develop. We subsequently use them to investigate the effect of curvature in wave propagation. We finally show that DNA-based waves can compute the optimal path within a maze. We thus suggest that coupling configurable microfluidics to programmable DNA-based dissipative reaction networks is a powerful route to investigate spatiotemporal order formation in chemistry.

Application of cattle slurry containing Mycobacterium avium subsp. paratuberculosis (MAP) to grassland soil and its effect on the relationship between MAP and free-living amoeba.

Slurry from dairy farms is commonly used to fertilize crops and pastures. This mixture of manure, urine and water can harbor multiple microbial pathogens among which Mycobacterium avium subsp. paratuberculosis (MAP) is a major concern. Persistence of MAP in soil and infection of soil Acanthamoeba was evaluated by culture, real-time IS900 PCR, and by staining of amoeba with acid-fast and vital stains comparing soils irrigated with MAP-spiked or control dairy farm slurry. MAP DNA was detected in soil for the 8 month study duration. MAP was detected by PCR from more soil samples for plots receiving MAP-spiked slurry (n=61/66) than from soils receiving control slurry (n=10/66 samples). Vital stains verified that intracellular MAP in amoeba was viable. More MAP was found in amoeba at the end of the study than immediately after slurry application. There was no relationship between MAP presence in soil and in amoeba over time. Infection of amoeba by MAP provides a protected niche for the persistence and even possibly the replication of MAP in soils. As others have suggested, MAP-infected amoeba may act like a "Trojan horse" providing a means for persistence in soils and potentially a source of infection for grazing animals.

Informativeness of polymorphic markers for prenatal diagnosis of recessive dystrophic epidermolysis bullosa in Spanish families at risk.

DNA polymorphic markers are useful for the prenatal diagnosis of generalized recessive dystrophic epidermolysis bullosa (GRDEB) in families with at least one child affected with the disease. It is our policy to investigate families at risk using DNA polymorphic markers before a new pregnancy is intended, to inform about the real chances of offering an accurate prenatal diagnosis based on such DNA markers. We have analysed 10 Spanish families with at least one child affected with GRDEB with three different markers linked to the type VII collagen gene: the intragenic PvuII RFLP, and two markers mapped close to the COL7A1 gene, an MspI polymorphism belonging to the anonymous marker D3S2, and the microsatellite D3S1100. The PvuII marker was partially informative in two of 10 families, and was fully informative in three additional families; The MspI marker was partially informative in two of 10 families, and was fully informative in three additional families; it was not informative in five families. The D3S1100 microsatellite was partially informative in two out of 10 families, and fully informative in the other eight families. Combination of all three markers was shown to be partially informative in one family and fully informative in the remaining nine families. Using this combination of markers, we have inferred an accurate linkage-based prenatal diagnosis of GRDEB in four pregnancies. Surprisingly, the intragenic marker PvuII had a very limited usefulness, despite the results of previous studies; the microsatellite D3S1100 offered the best results for an eventual prenatal diagnosis of GRDEB. However, families at risk should be informed that extragenic markers may fail due to the possibility of recombination, estimated as 5% for D3S1100.

Historical and current atmospheric deposition to the epilithic lichen Xanthoparmelia in Maricopa County, Arizona.

Spatial patterns of atmospheric deposition of trace elements to an epilithic lichen were assessed using a spatial grid of 28 field sites in 1998 throughout Maricopa County, Arizona, USA. In addition, samples of Xanthoparmelia spp. from Arizona State University lichen herbarium material (1975-1976) was utilized for a limited number of sites in order to explore temporal trends. The lichen material was cleaned, wet digested and analyzed by ICP-MS for a suite of elemental concentrations [antimony (Sb), cadmium (Cd), cerium (Ce), chromium (Cr), cobalt (Co), copper (Cu), dysprosium (Dy), europium (Eu), gadolinium (Gd), gold (Au), holmium (Ho), lead (Pb), lutetium (Lu), neodymium (Nd), nickel (Ni), palladium (Pd), platinum (Pt), praseodymium (Pr), samarium (Sm), scandium (Sc), silver (Ag), terbium (Tb), thulium (Tm), tin (Sn), uranium (U), ytterbium (Yb), yttrium (Y), and zinc (Zn)]. Cluster analysis and principal component analysis suggest three major factors, which, depending on regional aerosol fractionation, explain most of the variation in elemental signatures: (1) a group of widely distributed rare earth elements (2) a highly homogenous Co, Cr, Ni, and Sc component representing the influence of mafic rocks, and (3) anthropogenic emissions. Elemental concentrations in Maricopa County lichens were generally comparable to those reported for relatively unpolluted areas. Only highly urbanized regions, such as the greater Phoenix Metropolitan Area and the NW corner of the county, exhibited elevated concentrations for Zn, Cu, Pb, and Cd. Lead levels in lichens have fallen over the last 30 years by 71%, while Zn concentrations for some regions have increased by as much as 245%. From the spatial pattern of elemental deposition for Cd, Cu, Ni, Pr, Pb, and Cu, we infer that agriculture, mining, industrial activities, and traffic probably are the major air pollutant sources in Maricopa County.

Identification and partial characterization of excretory/secretory products with proteolytic activity in Giardia intestinalis.

This report examines the presence of proteolytic activity detected in media collected from in vitro cultures of Giardia intestinalis, and the partial characterization by gelatin-substrate polyacrylamide gel electrophoresis and inhibition studies. Gelatin-substrate polyacrylamide gel electrophoresis revealed 6 bands with proteolytic activity, with estimated molecular weights of 36, 59, 63, 72, 103, and 175 kDa. These bands were not present in the control medium. On the other hand, G. intestinalis trophozoite lysates showed proteolytic bands at 16, 20, 66, 82, 108, and 120 kDa, thus indicating that intracellular proteases could be different from the excretory/secretory (E/S) products. Based on inhibition studies, 2 bands of 59 and 63 kDa were inhibited by iodoacetic acid, indicating the presence of cysteine proteases. Partial inhibition of a band of 36 kDa was found with EDTA, a metal-chelating agent, suggesting the possible presence of metalloproteases. The presence of aspartic and serine proteases were not detected under the assay conditions used. As G. intestinalis E/S may be involved in differentiation mechanisms of the parasite and also be responsible for the mucosal alterations that occur in giardiasis, the characterization of these proteases may facilitate their evaluation as targets in the therapy of the disease.