Effect of varying functional monomers in experimental self-adhesive composites: polymerization kinetics, cell metabolism influence and sealing ability

The aim was to evaluate the effects of adding different functional monomers to experimental self-adhesive composites (SACs) on polymerization kinetics, cell metabolic activity, and sealing ability. SACs were formulated using urethane dimethacrylate as the base monomer and triethylene glycol dimethacrylate. Additionally, 10 wt.% of distinct functional monomers were added - 10-methacryloyloxydecyl dihydrogen phosphate, glycerol phosphate dimethacrylate (GPDM), 2-hydroxyethyl methacrylate (HEMA) or hydroxyethyl acrylamide (HEAA). ATR-FTIR was used to determine real-time polymerization kinetics (20 min,n= 3). The final extrapolated conversion and polymerization rates were determined (DC,max;Rp,max). TheDC,maxvalues were employed to calculate volumetric shrinkage. The MTT assay was performed on MDPC-23 cells using disc extracts at different concentrations (n= 8). Class V cavities were prepared in 60 sound human molars, assigned to six groups (n= 10), depending on the composite used and aging type (T0 or TC, if thermocycled for 10 000 cycles). One-way ANOVA, two-way, andKruskal-Wallistests were employed to treat the data (ɑ= 0.05). Varying the functional monomers had a large impact on DC,max, as confirmed by one-way ANOVA (p<0.001). The highest was obtained for HEMA (64 ± 3%). The HEMA and HEAA formulations were found to be significantly more toxic at concentrations below 100%. For microleakage, having a functional monomer or not did not show any improvement, irrespective of margin or aging period (Mann-Whitney U,p> 0.05). Larger functional monomers MDP and GPDM affected polymerization properties. Conversely, their acidity did not seem to be detrimental to cell metabolic activity. Regarding sealing ability, it seems that the functional monomers did not bring an advantage to the composites. Varying the functional monomer in SACs had a clear impact on the polymerization kinetics as well as on their cytotoxic potential. However, it did not confer better microleakage and sealing. Claiming self-adhesiveness based only on functional monomers seems dubious.

Flow-status and survival in severe aortic stenosis treated with TAVI – is flow rate superior to stroke volume index?

Background

Low-flow status, currently defined as a stroke volume index (SVi) &lt;35 mL/m2, is an important prognostic predictor for mortality after Transcatheter Aortic Valve Implantation (TAVI) for severe aortic stenosis (SAS). However, transaortic flow rate (FR) – defined as stroke volume divided by left ventricle ejection time - has recently been suggested to be superior to SVi in defining low-flow states, as it reflects more closely valvular resistance, while being independent of body surface area. Low FR is most consistently defined as FR&lt;200 mL/s.

Purpose

Determine the prognostic impact of FR and SVi before TAVI in survival after intervention for SAS.

Methods

A single-centre retrospective database of all TAVI performed between 2011 and 2019 was analyzed, and cases with pre-intervention echocardiograms available were included. Low-flow patients were identified according to basal FR (&lt;200 mL/s) or SVi (&lt;35 mL/m2), and compared with normal-flow cases. The primary endpoint was defined as time to all-cause death or last follow-up. The impact of flow-status (using FR or SVi) in survival was assessed using Kaplan-Meier curves and log-rank test, as well as Cox proportional hazard model adjusted for EuroSCORE II, using FR or SVi either as categorical or continuous variables. A subanalysis further compared patients with preserved and reduced ejection fraction (EF, &lt;52%). p&lt;0.05 was considered statistically significant.

Results

From 657 TAVI performed, 490 (74.6%) cases were included, with a median follow-up of 43 months. From those, 59.6% were defined as low-flow according to FR, and 43.3% using SVi. Low-flow patients, using each parameter, were of higher surgical risk (EuroSCORE II and STS scores), had more advanced NYHA classes, worse estimated creatinine clearance, and suffered more frequently from coronary artery disease. Low-FR patients were also older, and more predominantly female. Atrial fibrillation was more prevalent among low SVi cases. Functional aortic valve area was lower in low-flow patients using both assessments, but low-SVi was also associated with lower transaortic gradients, as well as lower EF before and after TAVI. Regarding all-cause mortality, low-SVi was associated with worse survival [p=0.02, hazard ratio (HR) 1.43 (1.05–1.94)], but not low-FR (p=0.4). However, low-SVi, when adjusted for EuroScore II, was no longer a predictor of all-cause mortality (p=0.08). When considering FR and SVi as continuous variables, a higher SVi (but not FR) was associated with better survival (HR 0.98, p=0.047) in multivariable analysis adjusted for EuroSCORE II. When stratifying according to preserved and reduced EF, both FR and SVi did not predict all-cause mortality.

Conclusions

Low-flow states are common in SAS population treated with TAVI, being frequently associated with worse symptoms and higher procedural risk. Low-SVi, but not low-FR, negatively impacts survival after intervention, representing a marker for prognosis after TAVI.

Funding Acknowledgement

Type of funding sources: None.

Liquefied Microcapsules Compartmentalizing Macrophages and Umbilical Cord-Derived Cells for Bone Tissue Engineering

Extraordinary capabilities underlie the potential use of immune cells, particularly macrophages, in bone tissue engineering. Indeed, the depletion of macrophages during bone repair often culminates in disease scenarios. Inspired by the native dynamics between immune and skeletal systems, this work proposes a straightforward in vitro method to bioengineer biomimetic bone niches using biological waste. For that, liquefied and semipermeable reservoirs generated by electrohydrodynamic atomization and layer-by-layer techniques are developed to coculture umbilical cord-derived human cells, namely monocyte-derived macrophages, mesenchymal-derived stromal cells (MSCs), and human umbilical vein endothelial cells (HUVECs). Poly(ε-caprolactone) microparticles are also added to the liquefied core to act as cell carriers. The fabricated microcapsules grant the successful development of viable microtissues, ensuring the high diffusion of bioactive factors. Interestingly, macrophages within the bioengineered microcapsules increase the release of osteocalcin, osteoprotegerin, and vascular endothelial growth factor. The cytokines profile variation indicates macrophages' polarization into a prohealing phenotype. Altogether, the incorporation of macrophages within the fabricated microcapsules allows to recreate an appropriate bone microenvironment for developing new bone mineralized microtissues. The proposed bioencapsulation protocol is a powerful self-regulated system, which might find great applicability in bone tissue engineering based on bottom-up approaches or disease modeling.

[Pre-Exposure Prophylaxis for Human Immunodeficiency Virus in the Medical Curricula in Portugal: A Cross-Sectional Analysis]

INTRODUCTION

Pre-exposure prophylaxis (PrEP) has gained relevance as a method of prevention for HIV in certain people and settings. Following the publication of the guideline on PrEP prescribing in Portugal, we aimed to assess the knowledge of Portuguese Medical Students about PrEP.

MATERIAL AND METHODS

An online survey was sent to Medical students of Portuguese Medical Schools. We conducted a descriptive analysis of the results and an analytic cross-sectional study to identify factors associated with "knowing about PrEP", "having had one class about PrEP" and "identifying eligible groups correctly".

RESULTS

Of the 796 students that responded to the survey, 64.6% were aware of what PrEP is. Of these, 34.44% acquired this knowledge during their training. Out of the total amount of respondents, 4.77% could identify correctly and completely the eligible groups for PrEP. As the training years went by, the probability of being aware of PrEP, having had one class about PrEP, and identifying the eligible groups correctly, increased. Of the sixth-year students, 43.48% had had one class about PrEP and among the students that were aware of PrEP, 28% identified what the eligible groups were. After adjusting for the school year, we found differences between Medical Schools regarding the outcomes. The association between the different ways of learning about PrEP and the ability to correctly identify eligible groups for PrEP was not statistically significant.

CONCLUSION

The differences between Medical Schools could be harmonized through changes in the medical curricula that would allow this topic to be addressed more often.

Prognostic utility of neutrophil-to-lymphocyte ratio in patients with metastatic colorectal cancer treated using different modalities

Introduction

Inflammation is a critical component in carcinogenesis. The neutrophil-to-lymphocyte ratio (nlr) has been retrospectively studied as a biomarker of prognosis in metastatic colorectal cancer (mcrc). Compared with a low nlr, a high nlr is associated with worse prognosis. In the present study, we compared real-world survival for patients with mcrc based on their nlr group, and we assessed the utility of the nlr in determining first-line chemotherapy and metastasectomy benefit.

Methods

In this retrospective and descriptive analysis of patients with mcrc undergoing first-line chemotherapy in a single centre, the last systemic absolute neutrophil and lymphocyte count before treatment was used for the nlr. A receiver operating characteristic curve was used to estimate the nlr cut-off value, dividing the patients into low and high nlr groups. Median overall survival (mos) was compared using Kaplan-Meier curves and the log-rank test. A multivariate analysis was performed using a Cox regression model.

Results

The 102 analyzed patients had a median follow-up of 15 months. Regardless of systemic therapy, approximately 20% of patients underwent metastasectomy. The nlr cut-off was established at 2.35, placing 45 patients in the low-risk group (nlr < 2.35) and 57 in the high-risk group (nlr ≥ 2.35). The Kaplan-Meier analysis showed a mos of 39.1 months in the low-risk group and 14.4 months in the high-risk group (p < 0.001). Multivariate Cox regression on the nlr estimated a hazard ratio of 3.08 (p = 0.01). Survival analysis in each risk subgroup, considering the history of metastasectomy, was also performed. In the low-risk group, mos was longer for patients undergoing metastasectomy than for those not undergoing the procedure (95.2 months vs. 22.6 months, p = 0.05). In the high-risk group, mos was not statistically different for patients undergoing or not undergoing metastasectomy (24.3 months vs. 12.7 months, p = 0.08).

Conclusions

Our real-world data analysis of nlr in patients with mcrc confirmed that this biomarker is useful in predicting survival. It also suggests that nlr is an effective tool to choose first-line treatment and to predict the benefit of metastasectomy.

Erratum to "Gastroenteropancreatic Neuroendocrine Neoplasia Characterization in Portugal: Results from the NETs Study Group of the Portuguese Society of Endocrinology, Diabetes and Metabolism"

[This corrects the article DOI: 10.1155/2019/4518742.].

Risk Score to Predict Dental Caries in Adult Patients for Use in the Clinical Setting

Background: There is a need for risk prediction tools in caries research. This investigation aimed to estimate and evaluate a risk score for prediction of dental caries. Materials and Methods: This case-cohort study included a random sample of 177 cases (with dental caries) and 220 controls (randomly sampled from the study population at baseline), followed for 3 years. The risk ratio (RR) for each potential predictor was estimated using a logistic regression model. The level of significance was 5%. Results: The risk model for dental caries included the predictors: “presence of bacterial plaque/calculus” (RR = 4.1), “restorations with more than 5 years” (RR = 2.3), “>8 teeth restored” (RR = 2.0), “history/active periodontitis” (RR = 1.7) and “presence of systemic condition” (RR = 1.4). The risk model discrimination (95% confidence interval) was 0.78 (0.73; 0.82) (p < 0.001, C-statistic). Patients were distributed into three risk groups based on the pre-analysis risk (54%): low risk (<half the pre-analysis risk; caries incidence = 6.8%), moderate risk (half-to-less than the pre-analysis risk; caries incidence = 20.4%) and high risk (≥the pre-analysis risk; caries incidence = 27%). Conclusions: The present study estimated a simple risk score for prediction of dental caries retrieved from a risk algorithm with good discrimination.

Gastroenteropancreatic Neuroendocrine Neoplasia Characterization in Portugal: Results from the NETs Study Group of the Portuguese Society of Endocrinology, Diabetes and Metabolism

BACKGROUND

The incidence of gastroenteropancreatic neuroendocrine neoplasms (GEP-NENs) has been increasing in the last five decades, but there is no large-scale data regarding these tumours in Portugal. We conducted a cross-sectional, multicentric study in main Portuguese centers to evaluate the clinical, pathological, and therapeutic profile of GEP-NENs.

METHODS

From November, 2012, to July, 2014, data from 293 patients diagnosed with GEP-NENs from 15 centers in Portugal was collected and registered in an online electronic platform.

RESULTS

Median age at diagnosis was 56.5 (range: 15-87) years with a preponderance of females (54.6%). The most frequent primary sites were the pancreas (31.1%), jejunum-ileum (24.2%), stomach (13.7%), and rectum (8.5%). Data regarding hormonal status was not available in most patients (82.3%). Stratified by the tumour grade (WHO 2010 classification), we observed 64.0% of NET G1, 24.7% of NET G2, and 11.3% of NEC. Poorly differentiated tumours occurred mainly in older patients (p = 0.017), were larger (p < 0.001), and presented more vascular (p = 0.004) and lymphatic (p = 0.001) invasion. At the time of diagnosis, 44.4% of GEP-NENs presented metastatic disease. Surgery (79.6%) and somatostatin analogues (30.7%) were the most frequently used therapies of GEP-NENs with reported grading.

CONCLUSION

In general, Portuguese patients with GEP-NENs presented similar characteristics to other populations described in the literature. This cross-sectional study represents the first step to establish a national database of GEP-NENs that may aid in understanding the clinical and epidemiological features of these tumours in Portugal.

Anogenital warts in pediatric population

The approach to children with anogenital warts in the context of sexual abuse is a challenge in clinical practice. This study aims to review the current knowledge of anogenital warts in children, the forms of transmission, and the association with sexual abuse and to propose a cross-sectional approach involving all medical specialties. A systematic review of the literature was conducted in Portuguese and English from January 2000 to June 2016 using the ISI Web of Knowledge and PubMed databases. Children aged 12 years or younger were included. The ethical and legal aspects were consulted in the Declaration and Convention on the Rights of Children and in the World Health Organization. Non-sexual and sexual transmission events of human papillomavirus in children have been well documented. The possibility of sexual transmission appears to be greater in children older than 4 years. In the case of anogenital warts in children younger than 4 years of age, the possibility of non-sexual transmission should be strongly considered in the absence of another sexually transmitted infection, clinical indicators, or history of sexual abuse. The importance of human papillomavirus genotyping in the evaluation of sexual abuse is controversial. A detailed medical history and physical examination of both the child and caregivers are critical during the course of the investigation. The likelihood of an association between human papillomavirus infection and sexual abuse increases directly with age. A multidisciplinary clinical approach improves the ability to identify sexual abuse in children with anogenital warts.

Pharmacokinetics of table and Port red wine anthocyanins: a crossover trial in healthy men

This study was designed to evaluate the pharmacokinetics of Port and table red wine anthocyanins in healthy men. Volunteers were recruited to drink 250 mL of a table red wine (221 mg of anthocyanins) and 150 mL of young Port red wine (49 mg of anthocyanins). Venous blood was collected from participants at 0, 15, 30, 60 and 120 min after wine ingestion. Urine samples were collected at baseline and at 120 min. Anthocyanins and anthocyanin metabolites in plasma and urine samples were quantified by HPLC-DAD and tentatively identified by LC-MS. Red wine anthocyanins were detected in their intact forms in both plasma and urine samples, but the glucuronylated metabolites of peonidin and malvidin (PnGlucr and MvGlucr) were the two main derivatives detected after both red wine consumptions. For the first time, and supported by the synthesis of Mv3Glucr, the main pathway followed by Mv3glc after absorption was described and involves anthocyanidin conjugation with glucuronic acid after glucose removal. Despite the lower total content of anthocyanins ingested when volunteers drank Port wine, no differences were observed in the plasma C_max of MvGlucr and PnGlucr after table and Port red wine consumption. The relative bioavailability of anthocyanins in Port wine was 96.58 ± 5.74%, compared to the anthocyanins present in red wine. In conclusion, both Port and table red wines are good sources of bioavailable anthocyanins.

TRANSDISCIPLINARITY IN STRATEGIC DECISIONS FOR ONCOLOGICAL TREATMENTS

The current models for equity and access to new oncological treatments are under strain due to the economic and demographic crisis in Europe as well as the rising costs of innovative drugs. Cancer treatment needs a model of patient-centered care in which an interdisciplinary care plan, based on evidence-based practice is essential for patient wellbeing. Physicians should be focused in the doctor-patient relationship and informed consent is important, especially when new medicines are prescribed. Related with informed consent, there is therapeutic privilege. Moreover, utilitarianism and social justice have to be considered without compromising human dignity and the principle of economy cannot be ignored in the provision of public services. An interdisciplinary approach is essential for the new oncological drugs approval. Therefore, transdisciplinary decision between civil society, pharmaceuticals, healthcare professionals and policy makers is essential in order to assure quality, access to innovation and equity in oncological care.

Immunomodulatory effects of crotoxin isolated from Crotalus durissus terrificus venom in mice immunised with human serum albumin

Crotalus durissus terrificus venom and its main component, crotoxin (CTX), have the ability to down-modulate the immune system. Certain mechanisms mediated by cells and soluble factors of the immune system are responsible for the elimination of pathogenic molecules to ensure the specific protection against subsequent antigen contact. Accordingly, we evaluated the immunomodulatory effects of CTX on the immune response of mice that had been previously primed by immunisation with human serum albumin (HSA). CTX inoculation after HSA immunisation, along with complete Freund's adjuvant (CFA) or Aluminium hydroxide (Alum) immunisation, was able to suppress anti-HSA IgG1 and IgG2a antibody production. We showed that the inhibitory effects of this toxin are not mediated by necrosis or apoptosis of any lymphoid cell population. Lower proliferation of T lymphocytes from mice immunised with HSA/CFA or HSA/Alum that received the toxin was observed in comparison to the mice that were only immunised. In conclusion, CTX is able to exert potent inhibitory effects on humoral and cellular responses induced by HSA immunisation, even when injected after an innate immune response has been initiated.

Foscarnet-induced penile ulceration

Foscarnet is used to treat herpes viruses, including drug-resistant cytomegalovirus (CMV) and herpes simplex viruses types 1 and 2 (HSV-1 and HSV-2). There are some reports of intravenous foscarnet-induced penile and vulvar ulceration. The authors report a case of the development of severe penile ulcers after the initiation of intravenous foscarnet therapy.

Photodynamic therapy as adjunctive therapy for morpheaform basal cell carcinoma

The authors decided to evaluate the possible use of methyl-aminolevulinate photodynamic therapy (MAL-PDT) as adjunctive therapy for morpheaform basal cell carcinoma prior to standard surgical excision in order to reduce tumor size and volume and to facilitate surgical treatment. It was observed that MAL-PDT may be an option as an adjunctive therapy prior to standard surgical excision of morpheaform basal cell carcinoma, leading to less invasive surgery.

Immunochemical and biological characterization of monoclonal antibodies against BaP1, a metalloproteinase from Bothrops asper snake venom

BaP1 is a P-I class of Snake Venom Metalloproteinase (SVMP) relevant in the local tissue damage associated with envenomations by Bothrops asper, a medically-important species in Central America and parts of South America. Six monoclonal antibodies (MoAb) against BaP1 (MABaP1) were produced and characterized regarding their isotype, dissociation constant (K(d)), specificity and ability to neutralize BaP1-induced hemorrhagic and proteolytic activity. Two MABaP1 are IgM, three are IgG1 and one is IgG2b. The K(d)s of IgG MoAbs were in the nM range. All IgG MoAbs recognized conformational epitopes of BaP1 and B. asper venom components but failed to recognize venoms from 27 species of Viperidae, Colubridae and Elapidae families. Clone 7 cross-reacted with three P-I SVMPs tested (moojeni protease, insularinase and neuwiedase). BaP1-induced hemorrhage was totally neutralized by clones 3, 6 and 8 but not by clone 7. Inhibition of BaP1 enzymatic activity on a synthetic substrate by MABaP1 was totally achieved by clones 3 and 6, and partially by clone 8, but not by clone 7. In conclusion, these neutralizing MoAbs against BaP1 may become important tools to understand structure-function relationships of BaP1 and the role of P-I class SVMP in snakebite envenomation.

Identification of enteropathogenic and enterohaemorrhagic Escherichia coli strains by immunoserological detection of intimin

AIMS

To evaluate the sensitivity and specificity of polyclonal and monoclonal antibodies (Mabs) against intimin in the detection of enteropathogenic and enterohaemorrhagic Escherichia coli isolates using immunoblotting.

METHODS AND RESULTS

Polyclonal and Mabs against the intimin-conserved region were raised, and their reactivities were compared in enteropathogenic E. coli (EPEC) and enterohaemorrhagic E. coli (EHEC) isolates using immunoblotting analysis. In comparison with rat antiserum, rabbit anti-intimin IgG-enriched fraction had a stronger recognition pattern to a wide spectrum of intimin types in different EPEC and EHEC serotypes. On the other hand, murine monoclonal IgG2b specific to intimin, with dissociation constant of 1.3x10(-8) mol l(-1), failed in the detection of some of these isolates.

CONCLUSION

All employed antibodies showed 100% specificity, not reacting with any of the eae-negative isolates. The sensitivity range was according to the employed antisera, and 97% for rabbit anti-intimin IgG-enriched fraction, followed by 92% and 78% sensitivity with rat antisera and Mab.

SIGNIFICANCE AND IMPACT OF THE STUDY

The rabbit anti-intimin IgG-enriched fraction in immunoblotting analysis is a useful tool for EPEC and EHEC diagnoses.

Collagen binding is a key factor for the hemorrhagic activity of snake venom metalloproteinases

Snake venom metalloproteinases (SVMPs) are multifunctional enzymes involved in several symptoms following snakebite, such as severe local hemorrhage. Multidomain P-III SVMPs are strongly hemorrhagic, whereas single domain P-I SVMPs are not. This indicates that disintegrin-like and cysteine-rich domains allocate motifs that enable catalytic degradation of ECM components leading to disruption of capillary vessels. Interestingly, some P-III SVMPs are completely devoid of hemorrhagic activity despite their highly conserved disintegrin-like and cysteine-rich domains. This observation was approached in the present study by comparing the effects of jararhagin, a hemorrhagic P-III SVMP, and berythractivase, a pro-coagulant and non-hemorrhagic P-III SVMP. Both toxins inhibited collagen-induced platelet aggregation, but only jararhagin was able to bind to collagen I with high affinity. The monoclonal antibody MAJar 3, that neutralizes the hemorrhagic effect of Bothrops venoms and jararhagin binding to collagen, did not react with berythractivase. The three-dimensional structures of jararhagin and berythractivase were compared to explain the differential binding to collagen and MAJar 3. Thereby, we pinpointed a motif within the Da disintegrin subdomain located opposite to the catalytic domain. Jararhagin binds to both collagen I and IV in a triple helix-dependent manner and inhibited in vitro fibrillogenesis. The jararhagin-collagen complex retained the catalytic activity of the toxin as observed by hydrolysis of fibrin. Thus, we suggest that binding of hemorrhagic SVMPs to collagens I and IV occurs through a motif located in the Da subdomain. This allows accumulation of toxin molecules at the site of injection, close to capillary vessels, where their catalytic activity leads to a local hemorrhage. Toxins devoid of this motif would be more available for vascular internalization leading to systemic pro-coagulant effects. This reveals a novel function of the disintegrin domain in hemorrhage formation.

A validated PCR-based method to detect Listeria monocytogenes using raw milk as a food model--towards an international standard

A PCR assay with an internal amplification control was developed for Listeria monocytogenes. The assay has a 99% detection probability of seven cells per reaction. When tested against 38 L. monocytogenes strains and 52 nontarget strains, the PCR assay was 100% inclusive (positive signal from target) and 100% exclusive (no positive signal from nontarget). The assay was then evaluated in a collaborative trial involving 12 European laboratories, where it was tested against an additional 14 target and 14 nontarget strains. In that trial, the inclusivity was 100% and the exclusivity was 99.4%, and both the accordance (repeatability) and the concordance (reproducibility) were 99.4%. The assay was incorporated within a method for the detection of L. monocytogenes in raw milk, which involves 24 h of enrichment in half-Fraser broth followed by 16 h of enrichment in a medium that can be added directly into the PCR. The performance characteristics of the PCR-based method were evaluated in a collaborative trial involving 13 European laboratories. In that trial, a specificity value (percentage of correct identification of blank samples) of 81.8% was obtained; the accordance was 87.9%, and the concordance was 68.1%. The sensitivity (correct identification of milk samples inoculated with 20 to 200 L. monocytogenes cells per 25 ml) was 89.4%, the accordance was 81.2%, and the concordance was 80.7%. This method provides a basis for the application of routine PCR-based analysis to dairy products and other foodstuffs and should be appropriate for international standardization.

Comparison of different monoclonal antibodies against immunosuppressive proteins of Ascaris suum

The extract of Ascaris suum suppresses the humoral and cellular immune responses to unrelated antigens in the mouse. In order to further characterize the suppressive components of A. suum, we produced specific monoclonal antibodies which can provide an important tool for the identification of these proteins. The A. suum immunosuppressive fractions isolated by gel filtration from an extract of adult worms were used to immunize BALB/c mice. Popliteal lymph node cells taken from the immunized animals were fused with SP2/O myeloma cells and the cloned hybrid cells obtained were screened to determine the specificity of secreted antibodies. Three monoclonal antibodies named MAIP-1, MAIP-2 and MAIP-3 were selected and were shown to react with different epitopes of high molecular weight proteins from the A. suum extract. All antibody molecules have kappa-type light chains but differ in heavy chain isotype. MAIP-1 is a mouse IgM, MAIP-2 is an IgA immunoglobulin and MAIP-3 is an IgG1 immunoglobulin and they recognize the antigen with affinity constants of 1.3 x 10(10) M-1, 7.1 x 10(9) M-1 and 3.8 x 10(7) M-1, respectively. The proteins recognized by these monoclonal antibodies (PAS-1, PAS-2 and PAS-3) were purified from the crude extract by affinity chromatography and injected with ovalbumin in BALB/c mice in order to determine their suppressive activity on heterologous antibody production. It was demonstrated that these three proteins are able to significantly suppress anti-ovalbumin antibody secretion, with PAS-1 being more efficient than the others.

Agonist-bound nuclear receptors: not just targets of coactivators

Members of the nuclear receptor superfamily of ligand-regulated transcription factors are targets of a wide range of lipophilic signaling molecules as well as several drugs and xenobiotics that modulate many aspects of physiology and metabolism. Agonist binding to receptors is associated with recruitment of coactivators, which are essential for activation of target gene transcription. However, several biochemical and molecular genetic studies have shown that a full understanding of the function of agonist-bound receptors must also accommodate the recruitment of corepressors. These factors may attenuate agonist-induced transactivation, act more transiently as part of a cycle of cofactors recruited to target promoters by ligand-bound receptors, or function in hormone-dependent repression of target gene expression.