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A technique to evaluate the refractive index, the absorption coefficient and the thickness of holographic recording materials is presented. The materials are in the form of a thin layer of film deposited on a thick glass plate. The experimental reflectances of p-polarized light are measured as a function of the incident angle, and the values of refractive index, thickness and absorption coefficient of the layer are obtained using the theoretical equation for reflectance. As examples, holographic silver halide emulsions and photopolymers are analyzed. The agreement between the calculated reflectances, using the thickness and refractive index obtained, and the measured reflectances is satisfactory.Se presenta una técnica experimental para determinar el índice de refracción, el coeficiente de absorción y el espesor de materiales de registro holográfico. Los materiales están depositados como capas finas sobre una lámina planoparalela de vidrio. Se determina experimentalmente la reflectancia en función del ángulo de incidencia para luz polarizada linealmente paralela al plano de incidencia, de modo que los valores del índice de refracción, el coeficiente de absorción y el espesor se obtienen ajustando la ecuación de la reflectancia teórica a los datos experimentales. Como ejemplos se han analizado emulsiones fotográficas y fotopolímeros, obteniéndose un buen ajuste entre la función teórica y los datos experimentales.

The reuse of water for agricultural practices becomes progressively more important due to increasing demands for a transition to a circular economy. Treated wastewater can be an alternative option of blue water used for the irrigation of crops but its risks need to be evaluated. This study assesses the uptake and metabolization of pharmaceuticals and personal care products (PPCPs) derived from treated wastewater into lettuce as well as the impact on root-associated bacteria under a realistic and worst-case scenario. Lettuce was grown in a controlled greenhouse and irrigated with water or treated wastewater spiked with and without a mixture of fourteen different PPCPs at 10 μg/L or 100 μg/L. After harvesting the plants, the same soil was reused for a consecutive cultivation campaign to test for the accumulation of PPCPs. Twelve out of fourteen spiked PPCPs were detected in lettuce roots, and thirteen in leaves. In roots, highest concentrations were measured for sucralose, sulfamethoxazole and citalopram, while sucralose, acesulfame and carbamazepine were the highest in leaves. Higher PPCP concentrations were found in lettuce roots irrigated with spiked treated wastewater than in those irrigated with spiked water. The absolute bacterial abundance remained stable over both cultivation campaigns and was not affected by any of the treatments (type of irrigation water (water vs. wastewater) nor concentration of PPCPs). However, the irrigation of lettuce with treated wastewater had a significant effect on the microbial α-diversity indices at the end of the second cultivation campaign, and modified the structure and community composition of root-associated bacteria at the end of both campaigns. Five and fourteen bacterial families were shown to be responsible for the observed changes at the end of the first and second cultivation campaign, respectively. Relative abundance of Haliangium and the clade Allorhizobium-Neorhizobium-Pararhizobium-Rhizobium was significantly affected in response to PCPPs exposure. Caulobacter, Cellvibrio, Hydrogenophaga and Rhizobacter were significantly affected in microcosms irrigated with wastewater., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 The Authors. Published by Elsevier B.V. All rights reserved.)

Introduction: Therapeutic hypothermia (TH) improves survival and neurological prognosis in hypoxic-ischemic encephalopathic (HIE) babies, being better the sooner TH is implemented. HIE babies are born more frequently in a non-cooling centre and need to be referred., Methods: Prospective-observational study (April 18 2018 - November 19 2019). Newborns (≥34 weeks of gestational age (GA) and >1800 g) with moderate/severe HIE on non-servocontrolled therapeutic hypothermia by the two neonatal transport teams in Catalonia., Results: 51 newborns. The median stabilisation and transport time were 68 min (p25-75, 45-85 min) and 30 min (p25-75, 15-45 min), respectively. The mean age at arrival at the receiving unit was 4 h and 18 min (SD 96.6). The incubator was set off in 43 (84%), iced-packs 11 (21.5%) and both (11, 21.5%). Target temperature was reached in 19 (37.3%) babies. There were no differences in the overcooling in relation to the measures applied. The transport duration was not related with temperature stabilisation or target temperature reachiness., Conclusions: Rectal temperature monitorisation is compulsory for the stabilisation and the application of non-servocontrolled hypothermia during transport. There is still time for improving in the administration of this treatment during transport. Servo-controlled hypothermia would be a better alternative to improve the management of HIE babies., (Copyright © 2021 Asociación Española de Pediatría. Published by Elsevier España, S.L.U. All rights reserved.)

The implementation of the new Water Reuse regulation in the European Union brings to the forefront the need to evaluate the risks of using wastewater for crop irrigation. Here, a two-tier ecotoxicological risk assessment was performed to evaluate the fate of wastewater-borne micropollutants in soil and their ecotoxicological impact on plants and soil microorganisms. To this end, two successive cultivation campaigns of lettuces were irrigated with wastewater (at agronomical dose (not spiked) and spiked with a mixture of 14 pharmaceuticals at 10 and 100 µg/L each) in a controlled greenhouse experiment. Over the two cultivation campaigns, an accumulation of PPCPs was observed in soil microcosms irrigated with wastewater spiked with 100 μg/L of PPCPs with the highest concentrations detected for clarithromycin, hydrochlorothiazide, citalopram, climbazole and carbamazepine. The abundance of bacterial and fungal communities remained stable over the two cultivation campaigns and was not affected by any of the irrigation regimes applied. Similarly, no changes were observed in the abundance of ammonium oxidizing archaea (AOA) and bacteria (AOB), nor in clade A of commamox no matter the cultivation campaign or the irrigation regime considered. Only a slight increase was detected in clade B of commamox bacteria after the second cultivation campaign. Sulfamethoxazole-resistant and -degrading bacteria were not impacted either. The irrigation regimes had only a limited effect on the bacterial evenness. However, in response to wastewater irrigation the structure of soil bacterial community significantly changed the relative abundance of Acidobacteria, Chloroflexi, Verrucomicrobia, Beta-, Gamma- and Deltaprotebacteria. Twenty-eight operational taxonomic units (OTUs) were identified as responsible for the changes observed within the bacterial communities of soils irrigated with wastewater or with water. Interestingly, the relative abundance of these OTUs was similar in soils irrigated with either spiked or non-spiked irrigation solutions. This indicates that under both agronomical and worst-case scenario the mixture of fourteen PPCPs had no effect on soil bacterial community., (Copyright © 2021. Published by Elsevier Inc.)

Mining activities frequently leave a legacy of residues that remain in the area for long periods causing the pollution of surroundings. We studied on a 100 year-old mine, the behavior of potentially toxic elements (PTEs) and their ecotoxicological impact on activity and diversity of microorganisms. The PTEs contamination assessment allowed the classification of the materials as highly (reference- and contaminated-samples) and very highly polluted (illegal spill of olive mill wastes (OMW), tailings, and dumps). OMW presented the lowest enzymatic activities while tailings and dumps had low dehydrogenase and arylsulfatase activities. All the α-diversity indices studied were negatively impacted in dumps. Tailings had lower Chao1 and PD whole tree values as compared to those of reference-samples. β-diversity analysis showed similar bacterial community composition for reference- and contaminated-samples, significantly differing from that of tailings and dumps. The relative abundance of Gemmatimonadetes, Bacteroidetes, and Verrucomicrobia was lower in OMW, tailings, and dumps as compared to reference-samples. Fifty-seven operational taxonomic units were selected as responsible for the changes observed between samples. This study highlights that assessing the relationship between physicochemical properties and microbial diversity and activity gives clues about ongoing regulating processes that can be helpful for stakeholders to define an appropriate management strategy., (Copyright © 2020 Elsevier B.V. All rights reserved.)

Failure to understand the microbial ecology driving the proliferation of antibiotic resistance in the environment prevents us from developing strategies to limit the spread of antibiotic resistant infectious disease. In this study, we developed for the first time a tyramide signal amplification-fluorescence in situ hybridization-fluorescence-activated cell sorting protocol (TSA-FISH-FACS) for the characterization of all vanA carrying bacteria in wastewater samples. Firstly, we validated the TSA-FISH protocol through microscopy in pure cultures and wastewater influent. Then, samples were sorted and quantified by FACS and qPCR. Significantly higher percentage tagging of cells was detected in vanA carrying pure cultures and wastewater samples spiked with vanA carrying cells as compared to vanA negative Gram positive strains and non-spiked wastewater samples respectively. qPCR analysis targeting vanZ, a regulating gene in the vanA cluster, showed its relative abundance was significantly greater in Enterococcus faecium ATCC 700221-spiked and positively sorted samples compared to the E. faecium spiked and negatively sorted samples. Phylogenetic analysis was then performed. Although further efforts are needed to overcome technical problems, we have, for the first time, demonstrated sorting bacterial-cells carrying antibiotic resistance genes from wastewater samples through a TSA-FISH-FACS protocol and provided insight into the microbial ecology of vancomycin resistant bacteria. Future potential applications using this approach will include the separation of members of an environmental microbial community (cultured and hard-to-culture) to allow for metagenomics on single cells or, in the case of clumping, targeting a smaller portion of the community with a priori knowledge that the target gene is present., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020 Elsevier B.V. All rights reserved.)

Pediatric large B-cell lymphomas (LBCLs) share morphological and phenotypic features with adult types but have better prognosis. The higher frequency of some subtypes such as LBCL with IRF4 rearrangement (LBCL-IRF4) in children suggests that some age-related biological differences may exist. To characterize the genetic and molecular heterogeneity of these tumors, we studied 31 diffuse LBCLs (DLBCLs), not otherwise specified (NOS); 20 LBCL-IRF4 cases; and 12 cases of high-grade B-cell lymphoma (HGBCL), NOS in patients ≤25 years using an integrated approach, including targeted gene sequencing, copy-number arrays, and gene expression profiling. Each subgroup displayed different molecular profiles. LBCL-IRF4 had frequent mutations in IRF4 and NF-κB pathway genes (CARD11, CD79B, and MYD88), losses of 17p13 and gains of chromosome 7, 11q12.3-q25, whereas DLBCL, NOS was predominantly of germinal center B-cell (GCB) subtype and carried gene mutations similar to the adult counterpart (eg, SOCS1 and KMT2D), gains of 2p16/REL, and losses of 19p13/CD70. A subset of HGBCL, NOS displayed recurrent alterations of Burkitt lymphoma-related genes such as MYC, ID3, and DDX3X and homozygous deletions of 9p21/CDKN2A, whereas other cases were genetically closer to GCB DLBCL. Factors related to unfavorable outcome were age >18 years; activated B-cell (ABC) DLBCL profile, HGBCL, NOS, high genetic complexity, 1q21-q44 gains, 2p16/REL gains/amplifications, 19p13/CD70 homozygous deletions, and TP53 and MYC mutations. In conclusion, these findings further unravel the molecular heterogeneity of pediatric and young adult LBCL, improve the classification of this group of tumors, and provide new parameters for risk stratification.

Modern agricultural practices largely rely on pesticides to protect crops against various pests and to ensure high yields. Following their application to crops a large amount of pesticides ends up in soil where they may affect non-target organisms, among which microorganisms. We assessed the effects of the carbamate nematicide oxamyl on the whole bacterial diversity of an agricultural soil exhibiting enhanced biodegradation of oxamyl through 16S rRNA amplicon next generation sequencing (NGS) and on the oxamyl-degrading bacterial community through cehA q-PCR analysis and 14 C-oxamyl mineralization assays. Oxamyl was rapidly mineralized by the indigenous microorganisms reaching >70% within a month. Concomitantly, a significant increase in the number of oxamyl-degrading microorganisms was observed. NGS analysis of the total (DNA) and active (RNA) bacterial community showed no changes in α-diversity indices in response to oxamyl exposure. Analysis of the β-diversity revealed significant changes in the composition of the soil bacterial community after 13 and 30 days of oxamyl exposure only when the active fraction of the bacterial community was considered. These changes were associated with seven OTUs related to Proteobacteria (5), Acidobacteria (1) and Actinobacteria (1). The relative abundance of the dominant bacterial phyla were not affected by oxamyl, except of Bacteroidetes and Gemmatimonadetes which decreased after 13 and 30 days of oxamyl exposure respectively. To conclude, oxamyl induced changes in the abundance of oxamyl-degrading microorganisms and on the diversity of the soil bacterial community. The latter became evident only upon RNA-based NGS analysis emphasizing the utility of such approaches when the effects of pesticides on the soil microbial community are explored., (Copyright © 2018 Elsevier B.V. All rights reserved.)

The survival rate of cancer patients has increased considerably in the last 20 years owing to significant efforts made in prevention, early detection protocols, combined chemotherapy regimens, targeted therapies, refined radiotherapy and cancer vaccines. However, metastasis and acquired resistance to current therapies represent two major challenges for achieving long-term cure. Therefore, new treatment strategies must be developed. One promising alternative is epigenetic-based therapies, of which miRNAs are at the forefront. MicroRNAs are endogenous small non-coding RNAs, often deregulated in cancer, which regulate gene expression by specific binding to the 3'-UTR of target genes. They are excellent candidates for therapy since miRNAs can regulate multiple targets of the same or different pathways, thereby minimizing the risk of resistance development or compensatory mechanisms. In this review, the mechanisms that lead to miRNA deregulation in cancer, their feasibility as therapeutic tools and the different strategies for the pharmacological manipulation of miRNAs in preclinical animal models are discussed., (Copyright © 2013 Elsevier Ltd. All rights reserved.)

Unlabelled: Vancomycin is widely used in haemodialysis (HD) patients for treating infections of vascular access due to St. Aureus. To avoid subtherapeutic levels it is important to know the adequate dosing in patients undergoing haemodialysis with high flux membranes., Objective: The aim of this study was to evaluate whether HD patients treated with 1 g intravenous (IV) vancomycin reached optimum plasma levels., Material and Methods: In a crossover design we studied 28 chronic HD patients, 3 times a week, treated with vancomycin between 15/2/2006 and 14/2/2007. Antibiotic was given at dose of 1 g during the last hour of dialysis session. Plasma levels of vancomycin were measured immediately before next HD (preHD1) and after (postHD1), and prior to the beginning of the second next session (preHD2). We evaluated age, sex, dry height, week Kt/V and the type of membrane used., Results: Of 28 patients, 5 were analysed 3 times, 2 were analysed twice and 9 were analysed once . There were 43 samples, 19 men (44,2%) and 24 women (55,8%), with a mean age of 70 +/- 8,4 years. 1 g dose is equivalent to > 15 mg/kg in 31 patients (72,1%) and < 15 mg/kg in 12 (27,9%). The type of membrane used was high flux polyetersulfone (PES-AP) (44,2%), eval (7%), medium-low polyetersulfone (PES-BP) (32,5%) and polyacrylonitrile (16,3%). PreHD1 mean concentration results for the total population was 7,06 mg/ml, being 16,3% bellow optimum levels. There were not difference between patients treated with dose > 15 mg/kg (7,5 mg/ml) and < 15 mg/kg (6 m/ml). When the dose administered was > 15 mg/kg, 6,45% results were subtherapeutic, whereas if the dose was < 15 mg/kg, 41,67% values were bellow optimum levels (p<0,05). With regard to the dialyzers used, the lowest concentrations were observed with PES-AP (5,95 mg/ml) and the highest values were observed with PES-BP (7,27 mg/ml) (p no significance). No patient using PES-BP versus 31,58% patients using PES-AP showed suboptimum values (p> or =0,07). All postHD1 and preHD2 results were in subtherapeutic range (mean values, dose > and < 15 mg/kg and all types of membrane)., Conclusions: Based on the above results, the vancomycin dosing schedule of 1 g IV every 5-7 days is not recommended for patients undergoing haemodialysis with high flux membranes. Since there are not guidelines for handling this antibiotic in these patients our findings suggest that it may be necessary to monitorize predialysis plasma levels to avoid subtherapeutic values.

By High Resolution Consultation (HRC) we mean an ambulatory process of assistance fulfilled in a single day, by which treatment and diagnosis are established after all complementary tests have been carried out. Once diagnosed, the patient is discharged and resent to the doctor who had previously remitted him/ her. In the Cáceres sanitary area, with distances longer than 100- 120 km. and precarious local road communications, the introduction of hypertension (HTA) HRC has brought along important savings of sanitary and economical resources and it is perceived by the user as highly satisfactory. We have carried out an observational one- year study of our HCR HTA, in which 90 patients have been evaluated, out of which 74.4% came from primary assistance and 25.6% from specialized assistance. Once diagnosed, 61 patients were discharged and sent to receive primary assistance and 29 were kept in our outpatient nephrology consultation, justified by severe and/ or rebellious HTA in 11 cases and by renal failure in 16 cases; two of these patients are still being tested. Taking into account that in a traditional consultation a patient would need two or three visits and one or two days for complementary tests, our HTA HRC (by which patients are tested and diagnosed in a single day), brings along savings of one or two consultations and two to four relocations for new consultations and diagnostic explorations. In one year of HTA- HRC with 90 patients, we have saved from 212 to 302 consultations and from 302 to 604 relocations in comparison to the traditional organization and we have thus generated from 100 to 150 places for first appointments.

Unlabelled: In 2004, according to socio- demographic criteria and to the improvement in the welfare quality, we incorporated to the portfolio of services of our section a work tool that meant a novel technology; the "telemedicine". The Objective has been to asses the utility of telemedicine in the follow- up of the renal patients, bringing the consultation of nephrology closer to the patient's home as well as the relationship between two welfare levels., Material and Method: Retrospective and descriptive study of the patients with renal pathology treated in the consultation of telenephrology at our hospital in a period of time of 27 months (November 2004-January 2007). Such study is carried out in primary care centers of our sanitary area (4 centers). The general practician (G.P) starts up the system by elaborating a document of derivation to the consultation of "telenephrology". All this information is included in a computerized data base that arrives via "Intranet" at the Hospital. From the consultation of Telenephrology the question is answered in real- time and through a system of videoconference., Results: A total of 105 first consultations have been made. 52 men and 53 women between 18 and 94 years of age. The diagnoses made in the consultation of Telenephrology have been: HTA (essential and secondary): 90 (85.7%). IRC: 61 (58%). Diabetic Nefropathy: 17 (16%). Renal Polycystic: 3 (2.8%). Urinary Lithiasis: 2 (1.9%). Congenital malformations: 1 (0.95%). Obstructive Nefropathy: 1 (0.95%). Chronic Glomerulonephritis: 6 (5.7%). Urinary infection: 1 (0.95%). Absence of renal pathology: 5 (4.8%). Some of the diagnoses coincide in several patients. The causes of the IRC have been Nephroangioesclerosis: 33. Diabetic Nefropathy: 14. Not drafted: 8. Disease to glomerular: 2. Urinary Lithiasis: 2. Renal Polycystic: 1. Ischemic Nephropathy: 1. 82 out of the 90 patients with HTA had essential arterial hypertension and 8 suffered from secondary HTA. The causes of this were: 5 HTA of parenquimatous renal origin. 2 vasculorrenal HTA and one with a primary hyperaldosteronism. The associated factors of risk to the observed HTA have been: Dyslipemia: 29. Diabetes méllitus: 29. Hyperuricemia: 11. Obesity: 12., Conclusion: The telecare in nephrology is possible promoting also the approach between two welfare levels, without a decrease in the quality of assistance. That way, we can get a lower number of hospital visits and, subsequently, a saving in sanitary transport as well as in hospital consultations.

Unlabelled: The aim of this paper is to analyze the ways of appearance, clinical characteristics, diagnosis and treatment related to patients suffering from primary hyperaldosteronism (HA1 masculine) in external nephrology consultation since their opening., Methodology: a retrospective study was carried out, checking out all HA1 masculine diagnosed patients of clinical records from 1981-2005., Results: 35 patients were diagnosed, with an average age of 50 and a predominance of men (82%). The main reason for starting the HA1 masculine study was persistent hypertension; other reasons were hypertension and hypopotassemia (34%). Sixteen of the cases were adenomas (7 classic adenomas and 9 renin-dependents) and fourteen of them were hyperplasia (10 bilateral hyperplasias and 4 primary adrenals hyperplasia). Five cases were excluded because they were waiting for complementary tests. For location diagnosis, gammagrafía I131cholesterol was the test showing more agreement with final diagnosis, and then RMN and TAC. In eight of the cases, an adrenal vein sampling was made. Ten of sixteen adenomas suffered a surgery performance. The result showed standardization of tensional levels, without any treatment in 60% of the cases. The rest of them are currently treated with spironolactone under an appropriate tensional control. Gynecomastia was the most usual adverse effect found., Conclusion: Contrary to other published papers, we found out a male predominance in our database. A similar incidence of adenomas e hyperplasias was obtained. The most usual way of appearance was persistent hypertension to treatment. Adenomas surgery does not imply healing results, though it achieves a better tensional levels control, using less drugs and diminishing aldosterone levels. It implies a descent in myocardic and vascular toxicity.

Objective: The objective of this study is the determination of the normal kidney size in children analysing the variables that have a good correlation with it. With these correlations the normal kidney size can be established and a diagnose of possible diseases set., Methods: The data was obtained through ecographies taken in 474 children between 0 and 18 years old that were under control for several reasons differently from the suspicion of a kidney disease. The information related to age, sex, weight, height and corporal surface was also taken., Results: We studied 265 girls and 209 boys. No difference was obtained between the size of the girls and boys kidneys. The regression analysis of the left kidney shows correlations of 0.911 for the height, 0.896 for the corporal surface, 0.863 for the weight and 0.857 for the age; while the one of the right kidney shows correlations of 0.921 for the height, 0.902 for the corporal surface, 0.872 for the age and 0.871 for the weight. The determination coefficients were 0.83 for the left kidney and 0.85 for the right one. The multivariant analysis shows that for both kidneys the height and the age are variables statistically significant as well as the corporal surface for the left kidney., Conclusions: The size parameters measured in the kidneys show a statistically significance correlation with certain parameters of the growing. The maximum correlation appears for the height of the patient, which allows establishing regression equations with the kidney size and the height and therefore to detect any deviations from these regression curve.

Background: Early nephrological referral and planned start of dialysis are associated with better prognosis after the beginning of renal replacement therapy (RRT). The aim of our study was to analyse patient clinical and analytic characteristics at the time of initiating dialysis and to evaluate if morbimortality was affected by planned start., Patients and Methods: We performed a retrospective study of all patients commencing RRT in a Spanish Hospital of The National Health System over two years (2003-2004). A total of 117 patients (47 female and 70 male) were included. We carried out a retrospective analysis of the demographic characteristics, patients' clinical and analytic conditions at the time of starting dialysis and hospitalization days and mortality in six months after starting dialysis. Patients were classified as planned (P) or unplanned (NP), depending on whether the first dialysis was planned or an emergency., Results: Sixty five patients (56.4%) started dialysis in a planned group while 52 (43.6%) were unplanned. In the former group, 83.1% of the patients had a vascular or peritoneal access available when starting RRT, whereas in the later group only the 3.8% had it. Planned dialysis initiation was associated with a high level of serum haemoglobin, haematocrit, calcium and albumin (p < 0.001), and a low level of serum urea, creatinine (p < 0.001) and phosphate (p < 0.05). More patients of the unplanned group were admitted at hospital at the initiation of dialysis (90.4% vs. 6.1%) and during the first 6 months (48% vs. 15.3%). The period of hospitalization was longer for the unplanned group (23.6 days vs 3 days) (p < 0.001). The 6-month-mortality was lower in the planned group (4.6% vs. 11.5%), whitout statistical difference., Conclusions: Planned dialysis initiation is associated with better clinical and metabolical conditions, greater probability of a vascular or peritoneal access availability and lower rate of hospitalization and mortality within 6 months after starting RRT

Strongyloides stercoralis, an important nematode pathogen of humans, is transmitted by contact with soil contaminated with the microscopic larvae of the parasite. We determined the cDNA sequence and deduced amino acid structure of a metallo-proteinase that is abundantly transcribed expressed by infective stage larvae of S. stercoralis. This deduced structure of the enzyme revealed a multi-domain protein that included an NH2-terminal peptidase. This peptidase consisted of a signal peptide, a pro-enzyme region, and a mature peptidase domain that included the metal ion co-ordinating motifs, HETSHALGVIH and SIMHY ("Met-turn"), characteristic of the catalytic active site of members of the metzincin superfamily of zinc metallo-endopeptidases. It was phylogenetically and structurally similar to astacin from the digestive gland of the crayfish Astacus astacus, to the HCH-1 peptidase of Caenorhabditis elegans required for hatching and migration of a post-embryonic neuroblast, and to the morphogenetically important peptidases, bone morphogenetic protein-1 (BMP-1) and Drosophila tolloid. In addition, the Strongyloides enzyme, designated strongylastacin, includes a central epidermal growth factor (EGF) domain followed by a carboxyl CUB (complement sub component C1r/C1s/embryonic sea urchin protein Uegf/bone morphogenetic protein) domain. Inspection of the dbEST database revealed the presence of at least 9 transcript clusters that are related to greater or lesser extent to strongylastacin; based on these expressed sequence tags, strongylastacin was expressed only in the infective third stage larvae, whereas other transcript clusters were expressed both in filariform and rhabditiform stages or only in the rhabditiform stage. Based on the deduced sequence, structure, and expression profile, strongylastacin is the probable candidate for the zinc-dependent metalloprotease, Ss40, known to be deployed by larvae of S. stercoralis to penetrate human skin to initiate infection.

Using degenerate oligonucleotide primers based on conserved active site residues, we have isolated a cDNA encoding an aspartic protease from the nematode parasite Strongyloides stercoralis, an important, enteric pathogen of humans. cDNAs encoding the aspartic protease were isolated from the infective, third stage larvae of the parasite as well as from free-living, rhabditiform larvae. Based on comparisons of other aspartic proteases, the cDNA encoded a short signal peptide, an enzyme pro-segment of 35 amino acid residues, and mature enzyme of 337 residues. Homology alignments using the proenzyme sequence showed that the novel S. stercoralis zymogen was 36% identical to human pepsinogen A and 36% identical to pepsinogen C (progastricin) from humans and macaques. Phylogenetic analyses using the Phylip program and analysis of Glx/Asx and Leu/Ile ratios indicated that the proenzyme was closely related to pepsinogen A-like enzymes from the free-living nematode Caenorhabditis elegans and Haemonchous contortus, a nematode parasite of the gastro-intestinal tract of sheep. We have termed this novel enzyme strongyloidespepsin.