New molecular tools for precision medicine in pituitary neuroendocrine tumors

Precision, personalized, or individualized medicine in pituitary neuroendocrine tumors (PitNETs) has become a major topic in the last few years. It is based on the use of biomarkers that predictively segregate patients and give answers to clinically relevant questions that help us in the individualization of their management. It allows us to make early diagnosis, predict response to medical treatments, predict surgical outcomes and investigate new targets for therapeutic molecules. So far, substantial progress has been made in this field, although there are still not enough precise tools that can be implemented in clinical practice. One of the main reasons is the excess overlap among clustered patients, with an error probability that is not currently acceptable for clinical practice. This overlap is due to the high heterogeneity of PitNETs, which is too complex to be overcome by the classical biomarker investigation approach. A systems biology approach based on artificial intelligence techniques seems to be able to give answers to each patient individually by building mathematical models through the interaction of multiple factors, including those of omics sciences. Integrated studies of different molecular omics techniques, as well as radiomics and clinical data are necessary to understand the whole system and to finally achieve the key to obtain precise biomarkers and implement personalized medicine. In this review we have focused on describing the current advances in the area of PitNETs based on the omics sciences, that are clearly going to be the new tool for precision medicine.

Visual Assessment of 2-Dimensional Levels Within 3-Dimensional Pathology Data Sets of Prostate Needle Biopsies Reveals Substantial Spatial Heterogeneity

Prostate cancer prognostication largely relies on visual assessment of a few thinly sectioned biopsy specimens under a microscope to assign a Gleason grade group (GG). Unfortunately, the assigned GG is not always associated with a patient's outcome in part because of the limited sampling of spatially heterogeneous tumors achieved by 2-dimensional histopathology. In this study, open-top light-sheet microscopy was used to obtain 3-dimensional pathology data sets that were assessed by 4 human readers. Intrabiopsy variability was assessed by asking readers to perform Gleason grading of 5 different levels per biopsy for a total of 20 core needle biopsies (ie, 100 total images). Intrabiopsy variability (Cohen κ) was calculated as the worst pairwise agreement in GG between individual levels within each biopsy and found to be 0.34, 0.34, 0.38, and 0.43 for the 4 pathologists. These preliminary results reveal that even within a 1-mm-diameter needle core, GG based on 2-dimensional images can vary dramatically depending on the location within a biopsy being analyzed. We believe that morphologic assessment of whole biopsies in 3 dimension has the potential to enable more reliable and consistent tumor grading.

Revisiting the usefulness of the short acute octreotide test to predict treatment outcomes in acromegaly

Introduction

We previously described that a short version of the acute octreotide test (sAOT) can predict the response to first-generation somatostatin receptor ligands (SRLs) in patients with acromegaly. We have prospectively reassessed the sAOT in patients from the ACROFAST study using current ultra-sensitive GH assays. We also studied the correlation of sAOT with tumor expression of E-cadherin and somatostatin receptor 2 (SSTR2) .

Methods

A total of 47 patients treated with SRLs for 6 months were evaluated with the sAOT at diagnosis and correlated with SRLs' response. Those patients whose IGF1 decreased to <3SDS from normal value were considered responders and those whose IGF1 was ≥3SDS, were considered non-responders. The 2 hours GH value (GH2h) after s.c. administration of 100 mcg of octreotide was used to define predictive cutoffs. E-cadherin and SSTR2 immunostaining in somatotropinoma tissue were investigated in 24/47 and 18/47 patients, respectively.

Results

In all, 30 patients were responders and 17 were non-responders. GH2h was 0.68 (0.25-1.98) ng/mL in responders vs 2.35 (1.59-9.37) ng/mL in non-responders (p<0.001). GH2h = 1.4ng/mL showed the highest ability to identify responders (accuracy of 81%, sensitivity of 73.3%, and specificity of 94.1%). GH2h = 4.3ng/mL was the best cutoff for non-response prediction (accuracy of 74%, sensitivity of 35.3%, and specificity of 96.7%). Patients with E-cadherin-positive tumors showed a lower GH2h than those with E-cadherin-negative tumors [0.9 (0.3-2.1) vs 3.3 (1.5-12.1) ng/mL; p<0.01], and patients with positive E-cadherin presented a higher score of SSTR2 (7.5 ± 4.2 vs 3.3 ± 2.1; p=0.01).

Conclusion

The sAOT is a good predictor tool for assessing response to SRLs and correlates with tumor E-cadherin and SSTR2 expression. Thus, it can be useful in clinical practice for therapeutic decision-making in patients with acromegaly.

Pre- and Post-Neoadjuvant Clinicopathological Parameters Can Help in the Prognosis and the Prediction of Response in HER2+ and Triple Negative Breast Cancer

Neoadjuvant treatment (NAT) is one of the most widely used options for HER2+ and triple negative (TN) early breast cancer (BC). Since around half of the patients treated with NAT do not achieve a pathologically complete response (pCR), biomarkers to predict resistance are urgently needed. The correlation of clinicopathological factors with pCR was studied in 150 patients (HER2 = 81; TN = 69) and pre- and post-NAT differences in tumour biomarkers were compared. Low estrogen receptor (ER) expression, high tumour-infiltrating lymphocytes (TILs) and low cT-stage were associated with pCR in HER2+ tumours (p = 0.022; p = 0.032 and p = 0.005, respectively). Furthermore, ER expression was also associated with residual cancer burden (RCB; p = 0.046) in the HER2+ subtype. Similarly, pre-NAT, low progesterone receptor expression (PR; 1-10%) was associated with higher RCB (p < 0.001) in TN tumours. Only clinical and pathological T-stage (cpT-stage) had prognostic capacity in HER2+ tumours, whereas pre-NAT cpT-stage and post-NAT TILs had this capacity for the prognosis of TN tumours. We conclude that ER and PR expression may help predict response to NAT in HER2 and TN BC and should be taken into account in residual tumours. Also, changes observed in the phenotype after NAT suggest the need to reevaluate biomarkers in surviving residual tumour cells.

Parameterizing Toxic Stress in Early Childhood: Maternal Depression, Maltreatment, and HPA-Axis Variation in a Pilot Intervention Study

Adverse experiences superseding a child's capacity to sustain regulation of emotion and adaptive function are theorized to constitute "toxic stressors" when they induce a deleterious biological response within an individual. We ascertained presumptive parameters of toxic stress among 164 low-income infants and toddlers (ages 4-48 months) from 132 families enrolled in Early Head Start (EHS). We randomized a subset of these families into a pilot intervention arm of parenting education (the Incredible Years, TIY), which supplemented the EHS curriculum. Official report child abuse and neglect (CAN) and child behavior were serially ascertained over the course of the study. We observed relatively low associations among maternal depression, CAN, caregiver-child relationship quality, hair cortisol, and adverse child behavioral outcomes. Moreover, despite poverty and the high prevalence (51%) of CAN in this sample, the frequency of clinical-level internalizing and externalizing behavior among the children did not exceed that of the general population, by their parents' report. The pilot supplementation of EHS with TIY improved attendance in group meetings but did not significantly reduce adverse behavioral outcomes or CAN. This study revealed marked independence of standard indices of toxic stress (child maltreatment, maternal depression, caregiver emotional unavailability) which have been presumed to be risk factors for the development of psychopathology. That they were weakly inter-correlated, and only modestly predictive of child behavioral outcomes in this EHS sample, caution against presumptions about the toxicity of individual stressors, highlight the importance of ascertaining risk (and compensatory influences) comprehensively, suggest buffering effects of programs like EHS, and demonstrate the need for greater understanding of what parameterizes resilience in early childhood.

DigiPatICS: Digital Pathology Transformation of the Catalan Health Institute Network of 8 Hospitals—Planification, Implementation, and Preliminary Results

Complete digital pathology transformation for primary histopathological diagnosis is a challenging yet rewarding endeavor. Its advantages are clear with more efficient workflows, but there are many technical and functional difficulties to be faced. The Catalan Health Institute (ICS) has started its DigiPatICS project, aiming to deploy digital pathology in an integrative, holistic, and comprehensive way within a network of 8 hospitals, over 168 pathologists, and over 1 million slides each year. We describe the bidding process and the careful planning that was required, followed by swift implementation in stages. The purpose of the DigiPatICS project is to increase patient safety and quality of care, improving diagnosis and the efficiency of processes in the pathological anatomy departments of the ICS through process improvement, digital pathology, and artificial intelligence tools.

Molecular profiling for acromegaly treatment: a validation study

Pharmacologic treatment of acromegaly is currently based upon assay-error strategy, the first-generation somatostatin receptor ligands (SRL) being the first-line treatment. However, about 50% of patients do not respond adequately to SRL. Our objective was to evaluate the potential usefulness of different molecular markers as predictors of response to SRL. We used somatotropinoma tissue obtained after surgery from a national cohort of 100 acromegalic patients. Seventy-one patients were treated with SRL during at least 6 months under maximal therapeutic doses according to IGF1 values. We analyzed the expression of SSTR2, SSTR5, AIP, CDH1 (E-cadherin), MKI67 (Ki-67), KLK10, DRD2, ARRB1, GHRL, In1-Ghrelin, PLAGL1 and PEBP1 (RKIP) by RT-qPCR and mutations in GNAS gene by Sanger sequencing. The response to SRL was categorized as complete response (CR), partial (PR) or non-response (NR) if IGF1 was normal, between >2<3 SDS or >3 SDS IGF1 at 6 months of follow-up, respectively. From the 71 patients treated, there were 27 CR (38%), 18 PR (25%) and 26 NR (37%). SSTR2, Ki-67 and E-cadherin were associated with SRL response (P < 0.03, P < 0.01 and P < 0.003, respectively). E-cadherin was the best discriminator for response prediction (AUC = 0.74, P < 0.02, PPV of 83.7%, NPV of 72.6%), which was validated at protein level. SSTR5 expression was higher in patients pre-treated with SRL before surgery. We conclude that somatotropinomas showed heterogeneity in the expression of genes associated with SRL response. E-cadherin was the best molecular predictor of response to SRL. Thus, the inclusion of E-cadherin in subsequent treatment-decision after surgical failure may be useful in acromegaly.

Fibrin Associated Epstein–Barr Virus Positive Large B Cell Lymphoma as a Complication of a Repaired Thoraco-abdominal Aortic Aneurysm

Background

Malignancies involving the aorta are extremely rare.

Case report

A 62 year old man with a history of open repair of a thoracic aortic aneurysm developed new visceral aneurysms and an anastomotic pseudoaneurysm. Fludeoxyglucose positron emission tomography/computed tomography, performed for suspicion of graft infection, found abnormal uptake around the bypass, the visceral aneurysms, and the femoral arteries. The patient was treated by embolisation of the visceral aneurysms and a thoracic endovascular aortic repair. Several bleeding complications occurred, and the patient died. Post-mortem revealed a fibrin associated Epstein–Barr virus positive diffuse large B cell lymphoma.

Conclusion

Patients with aortic aneurysms can develop malignancies including fibrin associated lymphoma. Clinical manifestations may be similar to those of an infectious process; timely diagnosis is uncommon.

•

Malignancies as fibrin associated lymphoma can be found involving aortic aneurysms.

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Clinical manifestations of a fibrin associated lymphoma can mimic an infection.

•

Timely diagnosis of aortic malignancies is uncommon.

A Randomized Trial of Home Visitation for CPS-Involved Families: The Moderating Impact of Maternal Depression and CPS History

Home visitation (HV) interventions may hold promise to improve parenting and prevent child maltreatment recidivism in families reported to child protective services (CPS) with young children, but this has rarely been studied. Findings are presented from an 18-month randomized controlled trial in which intact families ( N = 122) with at least one CPS report were provided with a facilitated connection to a paraprofessional evidence-based HV program or usual care services from child protection. Results are reported for changes in maternal stress, depression, and social support outcomes and repeat reports to CPS. No significant changes were found in maternal outcomes by group. Among nondepressed mothers or families without multiple CPS reports prior to study enrollment, HV was associated with a significantly lower likelihood of CPS report recidivism. These results indicate potential for HV to prevent maltreatment recidivism but suggest that higher intensity intervention is warranted for mothers exhibiting significant depressive symptoms or families with extensive CPS histories.

Service Engagement and Retention: Lessons from the Early Childhood Connections Program

The high attrition rates found in studies of early childhood home visitation create barriers to measuring the effectiveness of such programs. Most studies examine attrition at program completion. This practice may mask important differences in characteristics between families that end participation at various time points. This study helps address this gap by examining factors associated with percent attrition for early drop out (before three months) compared to the program midpoint (nine months or more) and program completion (18 months) using data from the treatment arm of a small feasibility study of enhanced referral to home visitation among child welfare-involved families (n = 64). Caregivers who identified as White tended to leave by the program midpoint and caregivers who had better social support were more likely to stay at the end of the program. This study is the only published study to date of participation in a community-based home visitation program by child welfare-involved families but several trends identified were consistent with prior studies with other populations. Given the very small sample size, both statistically significant and near significant trends are discussed in the context of existing literature. The practical variation found has implications for continuing to build knowledge of attrition in early childhood home visitation.

Trying to bridge the worlds of home visitation and child welfare: Lessons learned from a formative evaluation

Young children in families contacting the child welfare system are at high risk of recurrent maltreatment and poor developmental outcomes. Home visitation programs to support parenting may offer hope as a preventive resource but these programs are rarely linked with child welfare. This article describes findings from a formative evaluation of a program designed to connect child welfare-involved families to an existing evidence-supported home visitation program. The program, Early Childhood Connections (ECC), was developed by a field-university partnership including leaders from a public state child welfare system, regional early childhood education systems, and several local agencies providing family support services. Despite extensive and rigorous planning by the workgroup and collaborative refining of the intervention approach as agency needs changed, the continued structural and policy changes within both the home visitation agency and the child welfare agencies created significant ongoing barriers to implementation. On the other hand, child welfare-involved families were receptive to engaging with home visitation. Implications of lessons learned for ongoing program development in this area are discussed.

Dexibuprofen prevents neurodegeneration and cognitive decline in APPswe/PS1dE9 through multiple signaling pathways

The aim of the present study is to elucidate the neuronal pathways associated to NSAIDs causing a reduction of the risk and progression of Alzheimer's disease. The research was developed administering the active enantiomer of ibuprofen, dexibuprofen (DXI), in order to reduce associated gastric toxicity. DXI was administered from three to six-month-old female APPswe/PS1dE9 mice as a model of familial Alzheimer's disease. DXI treatment reduced the activation of glial cells and the cytokine release involved in the neurodegenerative process, especially TNFα. Moreover, DXI reduced soluble β-amyloid (Aβ1-42) plaque deposition by decreasing APP, BACE1 and facilitating Aβ degradation by enhancing insulin-degrading enzyme. DXI also decreased TAU hyperphosphorylation inhibiting c-Abl/CABLES/p-CDK5 activation signal pathway and prevented spatial learning and memory impairment in transgenic mice. Therefore, chronic DXI treatment could constitute a potential AD-modifying drug, both restoring cognitive functions and reversing multiple brain neuropathological hallmarks.

Prenatal microarray comparative genomic hybridization: Experience from the two first years of activity at the Lyon university-hospital

OBJECTIVES

This study aims to describe how microarray comparative genomic hybridization (aCGH) has shifted to become a prenatal diagnosis tool at the Lyon university-hospital.

MATERIALS AND METHODS

This retrospective study included all patients who were referred in the 3 pluridisciplinary centers for prenatal diagnosis of the Lyon university-hospital and who received a prenatal aCGH between June 2013 and June 2015. aCGH was systematically performed in parallel with a karyotype, using the PréCytoNEM array design.

RESULTS

A total of 260 microarrays were performed for the following indications: 249 abnormal ultrasounds (95.8%), 7 characterizations of chromosomal rearrangements (2.7%), and 4 twins with no abnormal ultrasounds (1.5%). With a resolution of 1 mega base, we found 235 normal results (90.4%), 23 abnormal results (8.8%) and 2 non-returns (0.8%). For the chromosomal rearrangements visible on the karyotype, aCGH identified all of the 12 unbalanced rearrangements and did not identify the 2 balanced rearrangements. Among the fetuses with normal karyotypes, 11 showed abnormal microarray results, corresponding to unbalanced cryptic chromosomal rearrangements (4.2%).

CONCLUSION

Transferring aCGH to a prenatal diagnosis at the Lyon university-hospital has increased the detection rate of chromosomal abnormalities by 4.2% compared to the single karyotype.

Evidence of pathway-specific basophil anergy induced by peanut oral immunotherapy in peanut-allergic children

BACKGROUND

In Westernized countries, over 1% of the population is allergic to peanuts or tree nuts, which carries a risk of severe allergic reactions. Several studies support the efficacy of peanut oral immunotherapy (OIT) for reducing the clinical sensitivity of affected individuals; however, the mechanisms of this effect are still being characterized. One mechanism that may contribute is the suppression of effector cells, such as basophils. Basophil anergy has been characterized in vitro as a pathway-specific hyporesponsiveness; however, this has not been demonstrated to occur in vivo.

OBJECTIVE

To evaluate the hypothesis that basophil anergy occurs in vivo due to chronic allergen exposure in the setting of a clinical oral immunotherapy trial.

METHODS

Samples of peripheral blood were obtained from subjects during a placebo-controlled clinical trial of peanut OIT. Basophil reactivity to in vitro stimulation with peanut allergen and controls was assessed by the upregulation of activation markers, CD63 and CD203c, measured by flow cytometry.

RESULTS

The upregulation of CD63 following stimulation of the IgE receptor, either specifically with peanut allergen or non-specifically with anti-IgE antibody, was strongly suppressed by active OIT. However, OIT did not significantly suppress this response in basophils stimulated by the distinct fMLP receptor pathway. In the subset of subjects with egg sensitization, active peanut OIT also suppressed CD63 upregulation in response to stimulation with egg allergen. Allergen OIT also suppressed the upregulation of CD203c including in response to stimulation with IL-3 alone.

CONCLUSION

Peanut OIT induces a hyporesponsive state in basophils that is consistent with pathway-specific anergy previously described in vitro. This suggests the hypothesis that effector cell anergy could contribute to clinical desensitization.

Effect of surface roughness, biofilm coverage and biofilm structure on the electrochemical efficiency of microbial cathodes

Biofilms of Geobacter sulfurreducens were formed under chronoamperometry at -0.5 V and -0.6 V vs. Ag/AgCl on stainless steel cathodes and tested for fumarate reduction. Increasing the surface roughness Ra from 2.0 μm to 4.0 μm increased currents by a factor of 1.6. The overall current density increased with biofilm coverage. When the current density was calculated with respect to the biofilm-coated area only, values up to 280 A/m(2) were derived. These values decreased with biofilm coverage and indicated that isolated cells or small colonies locally provide higher current density than dense colonies. Steel composition affected the current values because of differences in biofilm structure and electron transfer rates. Biofilms formed under polarisation revealed better electrochemical characteristics than biofilm developed at open circuit. This work opens up new guidelines for the design of microbial cathodes: a uniform carpet of isolated bacteria or small colonies should be targeted, avoiding the formation of large colonies.

[Community onset of methicillin resistant Staphylococcus aureus infections in previously healthy or health care-associated children in Argentina]

INTRODUCTION

Community-acquired methicillin-resistant Staphylococcus aureus infections (CA-MRSA) are prevalent in several countries of the world. These infections seem to differ clinically from those occurring within the health care system (HCS-MRSA).

OBJECTIVE

To compare clinical characteristics of infections by CA-MRSA and HCA-MRSA in the same community.

MATERIAL AND METHODS

Prospective, multicentric and comparative study. Children with clinically and microbiologically documented CA-MRSA were included.

RESULTS

Between 11/2006 and 11/2007, 840 infections caused by S. aureus were diagnosed. Of them 582 (68%) were community-acquired. Among these 356 (61%) were CA-MRSA. In this group, 75 (21%) were HCA-MRSA and 281 (79%) CA-MRSA. The median age was 36 months (range: 1-201). Chronic skin disease (13) and chronic disease of CNS (9) were the underlying disease predominant. Children with CA-MRSA had more frequency of previous antibiotic treatment (63 vs 34%) and previous medical consult (76 vs 52%), invasive procedures (31 vs 8%), surgery (15 vs 0.3%) and fever (94 vs 74%) (p = < 05). Children with CA-MRSA had subcutaneous abscesses (34 vs 15%) (p = < .05) more frequently. Bacteremia and sepsis rate was similar in both groups (21 vs 18%) and 17 vs 11%) respectively) (p = NS). Antibiotic resistance was more frequent in children with HCA-MRSA: Rifampin (7 vs 1%), trimethoprim-sulphametoxazole (7 vs 1%) and clindamycin (25 vs 9%) (p = < .05). Four children (5%) with HCA-MRSA infections died and 3 (1%) mCA-MRSA group (p = .05).

CONCLUSION

Children with HCA-MRSA infections more frequent antibiotic resistance than CA-MRSA should be reconsider the empiric antibiotic treatment of community-acquired infections in children in our area.

[Community-acquired methicillin-resistant Staphylococcus aureus infections in children: multicenter trial]

INTRODUCTION

Methicillin-resistant Staphylococcus aureus (MRSA) isolates are increasingly frequent causes of skin and soft-tissue infections or invasive infections in many communities. Local data are scarce.

OBJECTIVE

To determine the frequency, clinical features and outcome of infections caused by MRSA.

MATERIAL AND METHODS

Prospective and multicentric study of surveillance for community-acquired S. aureus infections in children from Argentina. Infections meeting the definition of community-acquired were identified. Demographic and clinical data were collected. Antibiotic susceptibilities were determined in the clinical microbiology laboratory with the methodology of the NCCLS.

RESULTS

From November 2006 to November 2007, 840 S. aureus infections were diagnosed, 447 of them were community-acquired. One hundred and thirty-five children with underlying disease or previous hospital admission were excluded. Two hundred and eighty one (62%) infections were community-acquired MRSA (CA-MRSA). The median age of children was 36 months (r:1-201), 60% were male. Among the CA-MRSA isolates, 62% were obtained from children with skin and soft-tissue infections, and 38% from children with invasive infections. Of them, osteomyelitis, arthritis, empyema and pneumonia were prevalent. Eigthteen percent of children had bacteremia and 11% sepsis. The rate of clindamycin resistance of CA-MRSA isolates was 10% and 1% for trimethoprim-sulfamethoxazole. Only 31% of children had appropriate treatment at admission. The median time of treatment delayed was 72 h. The median time of parenteral treatment was 6 days (r:1-70). In 72% of patients surgical treatment was required. Three children died (1%).

CONCLUSIONS

CA-MRSA isolates account for a high percentage and number of infections in children of Argentina. Community surveillance of CA-MRSA infections is critical to determine the appropriate empiric antibiotic treatment for either local or invasive infections. Clindamycin resistance was under 15% in the strains tested. Clindamycin should be use when CA-MRSA infection is suspected in children.

Contribution of Ara h 2 to peanut-specific, immunoglobulin E-mediated, cell activation

BACKGROUND

Ara h 2 is a potent peanut allergen but its contribution to the ability of a crude peanut extract (CPE) to cross-link IgE and activate mast cells has not been rigorously evaluated.

OBJECTIVE

To measure the contribution that Ara h 2 makes to the effector function of a CPE.

METHODS

Ara h 2 was specifically removed from a CPE as demonstrated by immunoblots, 2D gels, and an inhibitory ELISA. Functional assays of sham-treated and Ara h 2-depleted CPEs were performed with RBL SX-38 cells sensitized with IgE from highly peanut-allergic subjects and with naturally sensitized basophils.

RESULTS

Depletion of approximately 99% of the Ara h 2 from the CPE led to an increase in the concentration of the CPE necessary to give 50% of maximal degranulation (EC50) of the SX-38 cells following sensitization with sera that contain anti-Ara h 2 IgE. Assays with a pool of 10 sera showed a small but significant increase in the EC50 following depletion of Ara h 2 (1.65+/-0.15-fold; P<0.05) and assays of seven individual sera showed a similar increase in the average EC50 (1.7+/-0.2-fold; P<0.02). The percent of the anti-peanut IgE that binds Ara h 2 correlated with an increase in the EC50 of the CPE following depletion of Ara h 2 (r=0.83; P<0.02). On the other hand, data from three of these patients studied with a basophil histamine release assay did not show a significant effect of depletion of Ara h 2.

CONCLUSION

Based on its ability to cross-link IgE effectively, Ara h 2 is clearly an important peanut allergen. Its ability to cross-link IgE effectively from a specific serum is related to the proportion of anti-Ara h 2 in that serum but Ara h 2 does not account for a majority of the effector activity of the CPE for any of the sera studied.

The 18 kDa peanut oleosin is a candidate allergen for IgE-mediated reactions to peanuts

BACKGROUND

Peanut allergy is one of the five most frequent food allergies in children and in adults. Recently, we purified and evaluated the allergenicity of peanut oleosins, a family of small-sized proteins involved in the formation of peanut oil bodies.

METHODS

Allergenicity of the purified native protein and of the recombinant protein was tested by Western blot and by IgE-RIA.

RESULTS

We found IgE-binding with oleosin in 3 of 14 sera of patients who had suffered an allergic reaction to peanuts. Two sera reacted weakly against 16-18 kDa proteins corresponding to oleosin monomers, in Western blot. The main reacting bands had a molecular size estimated at approximately 34 kDa, approximately 50 kDa and approximately 68 kDa and could therefore correspond to oleosin oligomers. IgE reactivity was higher in extracts from roasted peanuts. The same phenomenon occurred with crude soybean oil fraction, with two bands of 16.5 and 24 kDa corresponding to monomers, and two bands of 50 kDa and 76 kDa corresponding to dimers and trimers, respectively. The 18 kDa band was observed in the 3 Western blots of a membrane-enriched fraction of recombinant oleosin produced in the Sf9-baculovirus expression system (performed with the 3 patient sera).

CONCLUSIONS

We have characterized a new peanut allergen which belongs to the oleosins, a family of proteins involved in the formation of oil bodies. The protein may be involved in some of the allergic cross-reactions to peanuts and soybeans.

Paracellular transport of avidin saturated or not with biotinylated cobalamin through Caco-2 cell epithelium monolayer

BACKGROUND

The cationic charge of molecules may promote their uptake across epithelia, which are rich in brush border anionic sites. The transport of unsaturated avidin and avidin saturated with a biotinylated compound was investigated across Caco-2 adenocarcinoma cell with fetal enterocyte phenotype.

METHODS

The unsaturated avidin and avidin saturated with either biotin or a biotinyl-cobalamin conjugate (biotinyl-Cbl) were iodinated to follow their transport through the cell monolayer. Their apparent permeability coefficient (Papp) and transepithelial pathway were determined and compared to those for control radiolabeled markers [3H]-mannitol, [125I]-beta-lactoglobulin and [57Co]-cobalamin/intrinsic factor (Cbl/IF).

RESULTS

The Papp of [125I]-avidin estimated at 2.8 x 10(-7) +/- 0.08 cm/s was close to that for mannitol that uses paracellular pathway. The binding of biotin or biotin conjugate to avidin enhanced its tetrameric conformation. The Papp for [125I]-avidin/biotin and [125I]- avidin/biotinyl-Cbl were respectively increased by 2-fold, compared to that for [125I]-avidin and 4-fold, compared to that for [125I]-beta-lactoglobulin and [54Co]-Cbl/IF. The protein was not accumulated in the cell and was found in intact form in the basolateral side, after its transport across the monolayer. Chloroquine (0.66 micromol/ml) did not significantly decrease the Papp for [125I]-avidin/biotinyl-Cbl. Conversely it decreased by 80% the Papp for Cbl/IF, that uses transepithelial pathway.

CONCLUSIONS

Avidin (either saturated or not with biotin and biotinyl-Cbl) was able to cross the monolayer of Caco-2 cell line through a paracellular pathway. This study pointed out the interest for using this protein as a shuttle for increasing the transport rate of biotinylated compounds through fetal epithelial barriers.

Transcytosis and coenzymatic conversion of [(57)Co]cobalamin bound to either endogenous transcobalamin II or exogenous intrinsic factor in caco-2 cells

We have examined the intracellular route, coenzyme conversion and transcytosis rate of [(57) Co]-labeled cobalamin (Cbl) in function of its presentation to the apical side of Caco-2 cells, either free or bound to intrinsic factor (IF). The free-presented Cbl was progressively bound to endogenous transcobalamin II (TCII) which may stem, in part, from a basolateral to apical passage. Its transcytosis was TCII-mediated as it was abolished when antibodies to TCII were added to the apical medium. The apparent permeability coefficient (P(app)) was estimated at 20.8+/-3.6, 103.5+/-17.7, 0.9+/-0.3 x 10(-5) cm/h for TCII-Cbl, IF-Cbl and haptocorrin-Cbl, respectively. Chloroquine inhibited the transcytosis rate of both TCII and IF-bound Cbl in a dose-dependent manner. Approximately 80% of apical Cbl, bound to either exogenous IF or endogenous TCII, was transported to the basolateral side as intact cyano[(57)Co]Cbl whereas the remainder was converted into Ado-Cbl and CH(3)-Cbl within the cells, as shown by HPLC analyses of a 1,000-g pellet and a 12,000-g supernatant. Coenzymatic conversion was virtually abolished by chloroquine. In conclusion, we suggest that apically presented free Cbl is internalized via TCII-dependent transport. The apically internalized CN-Cbl, bound to either IF or TCII, is processed via an acidic vesicle and part of it is converted to coenzymes, whereas bulk of CN-Cbl is transcytosed intact.

Sodium dodecyl sulphate gel electrophoretic preparation of protein standard human apolipoprotein B-48

Quantitation of plasma apo B-48 is currently performed by densitometric analysis of SDS-PAGE zones stained with Coomassie Brilliant Blue, using standard solutions of purified apo B-48. Here, preparative gel electrophoresis with a continuous elution system was used for purifying apo B-48. A chylomicron fraction was isolated by 107,000 g ultracentrifugation of a chylous ascite. The proteins were delipidated and precipitated in ethanol-diethyl ether (3:1, v/v), subjected to preparative electrophoresis in a 5% polyacrylamide gel and eluted in 0.1% SDS. The peak containing apo B-48 was eluted at a retention time of 445-480 min. The purity of apo B-48 in this fraction was assessed by the detection of a single band (M(r) 260,000) after silver staining and Coomassie staining of 4-15% gradient SDS-PAGE. It was confirmed by the absence of apo B-100 contaminant in Western blot of the purified protein preparation. A linear relationship was observed between the densitometric analysis of SDS-PAGE bands and the apo B-48 in a protein range of 0-3 microg. In conclusion, preparative gel electrophoresis was used in a single step purification of apo B-48 that was adapted to the preparation of a standard solution.

One-step purification of R-phycoerythrin from the red macroalga Palmaria palmata using preparative polyacrylamide gel electrophoresis

Phycoerythrin is a major light-harvesting pigment of red algae and cyanobacteria widely used as a fluorescent probe. In this study, phycoerythrin of the red macroalga Palmaria palmata was extracted by grinding the algal sample in liquid nitrogen, homogenisation in phosphate buffer and centrifugation. Phycoerythrin was then purified from this crude extract using preparative polyacrylamide gel electrophoresis (PAGE) with a continuous elution system and detected by its pink colour and fluorescence. The pigment presented a typical spectrum of R-phycoerythrin, with three absorbance maxima at 499, 545 and 565 nm, and displayed a fluorescence maximum at 578 nm. The absorbance ratio A565/A280, a criterion for purity, was 3.2. A single protein of relative molecular mass 240,000 was detected on native-PAGE with silver staining. Sodium dodecyl sulphate-PAGE demonstrated the presence of two major subunits with Mr 20,000 and 21,000, respectively, and a very minor subunit of Mr 30,000. These observations are consistent with the (alphabeta)6gamma subunit composition characteristic of R-phycoerythrin. Phycoerythrin of Palmaria palmata was determined to be present in larger amounts in autumn and showed a good stability up to 60 degrees C and between pH 3.5 and 9.5. In conclusion, phycoerythrin of Palmaria palmata was purified in a single-step using preparative PAGE. Obtaining pure R-phycoerythrin of Palmaria palmata will allow one to evaluate its fluorescence properties for future applications in biochemical techniques.

[21-hydroxylase autoantibodies as a marker of adrenal involvement in patients with autoimmune endocrinopathies]

Autoantibodies against 21-hydroxylase are common in idiopathic Addison's disease. The objective of this study was to determine the frequency of these antibodies in different endocrine autoimmune diseases with or without adrenal insufficiency and to follow up their evolution. We have used a radiobinding assay based on 125-I labeled 21-hydroxylase (21-OH-AB, RSR, UK). Serum samples with 21-hydroxylase antibodies levels equal or greater than 1.0 U/ml were considered as positive. We found these autoantibodies in 21/23 idiopathic Addisonian patients, in 0/18 patients with isolated hypothyroïdism, in 0/6 patients with isolated Grave's disease, in 2/14 patients with isolated ovarian failure, in 1/27 patients with 2 ou more associated autoimmune diseases without adrenal insufficiency. The comparison between patients with or without adrenal insufficiency has shown, for this assay, a sensibility of 91 %, a specificity of 96 %. The 21-hydroxylase autoantibodies were followed up in 4 patients with Addison's disease and showed progressive decreasing levels. We can not exclude that the addisonian sera might become negative for these antibodies after the total destruction of adrenal cortex. In conclusion, the presence of 21-hydroxylase autoantibodies is highly specific for idiopathic Addison's disease and the level of these antibodies decrease with disease duration.

Meningeal involvement in Behçet's disease: MRI

Behçet's disease is a multisystem disease that involves the central nervous system up to half of cases. Presentation with neurologic symptoms occurs in 5% of cases and cerebral venous thrombosis is one of its major manifestations. A feature not previously reported is progressive meningeal thickening with involvement of both optic nerves. We report a patient with cerebral venous thrombosis, meningeal thickening and contrast enhancement on MRI. This patient had two other unusual features: positive antineutrophil cytoplasmic antibodies and later development of central diabetes insipidus.

Isolation and characterization of proteic allergens in refined peanut oil

Allergic reactions to peanut oil are very much debated, even if the responsibility of peanut oil has been evoked in several cases of adverse reactions, including death related to severe asthma. The aim of the present study was to investigate the presence of allergenic proteins in peanut oil. Proteins were extracted from commercial refined peanut oil, with a relative content in the order of 0.1-0.2 microg per g of oil, and molecular sizes ranging from 14 up to 76kDa in SDS-PAGE. Eight protein bands were systematically observed in crude, neutralized and refined oils, with a molecular mass ranging from approximately 14 to 76 kDa, including one at 18 kDa which was identified by Western blot performed with serum from two allergic patients. The protein extract gave positive IgE-RIA with patient sera, positive in vitro leucocyte histamine release tests and positive skin-prick tests in allergic patients. The allergenic protein was purified by HPLC and [125I] iodide-labelled. It had an isoelectric point at 4.5 in isoelectrofocusing. In conclusion, we have demonstrated the presence of allergenic proteins in crude and refined peanut oil. These proteins are the same size as two allergens previously described in peanut protein extracts.

Characterization of the oligomeric behavior of a 16.5 kDa peanut oleosin by chromatography and electrophoresis of the iodinated form

Oleosins are amphipathic proteins associated with oil bodies in seeds. We purified the major 16,500 peanut oleosin by preparative SDS-PAGE. Autoradiography after SDS-PAGE separation of the iodinated oleosin revealed covalently bound oligomers with Mr of 21,000, 33,000, 44,000 and 51,000. The strong capacity of these oligomers to form aggregates and to be incorporated into large-sized detergent micelles was demonstrated by gel permeation and isoelectric focusing. A 50% ethanol concentration was necessary to elute the 16,500 oleosin from octyl groups in hydrophobic interaction chromatography showing its natural tendency to interact with lipid acyl chains. This oligomerization behavior in aqueous solution is an indirect reflection of the interactions that occur in the oil body.

Purification of a 41 kDa cod-allergenic protein

Cod fish is one of the foods most frequently involved in allergy. Only the cod allergen Gad c I, a 12.3 kDa parvalbumin, has been purified and characterized. Recently, we have detected allergen bands which have not previously been described, in particular a 41 kDa protein, by Western-blot. In the present work, this protein has been purified from a crude cod extract by ammonium sulfate fractionation, hydroxyapatite chromatography and preparative electrophoresis; a single band with an Mr of 41 x 10(3) was found in silver-stained sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The amino acid composition and the isoelectric point of the protein were determined. The purified protein (p41) was shown to bind specifically to reaginic IgE from sera of cod-allergic individuals and to a monoclonal anti-parvalbumin which recognizes specifically the first calcium binding site of parvalbumins. p41 may therefore contain a calcium binding site corresponding to an IgE-epitope similar to that of Gad c I.

Role of platelet-activating factor (PAF) and prostaglandins in colonic motor and secretory disturbances induced by Escherichia coli endotoxin in conscious rats

The involvement of prostaglandins (PGs) and platelet-activating factor (PAF) in the effects of Escherichia coli endotoxin on colonic motility, transit time, and fecal dry matter (DM) in rats were evaluated in this study. Myoelectric activity was investigated in a first group of male Wistar rats chronically implanted with intraparietal nichrome electrodes in the proximal colon. A second group of animals was chronically fitted with an intracolonic catheter (+2 cm from the cecocolonic junction); colonic transit time was then calculated as the Mean Retention Time (MRT) of 51Cr chromate sodium (1 microCi 0.1ml) administered through the intracolonic catheter and determined in the faeces collected at 1 hour interval on a conveyor belt. Fecal DM was measured after 24h dessication at 103 degrees C. E. coli endotoxin (50 micrograms/kg ip) increased the frequency of colonic contractions and decreased both colonic MRT and fecal DM. PAF (25 micrograms/kg ip) also decreased colonic MRT and fecal DM, and increased the frequency of colonic contractions. BN 50730 (10 mg/kg ip), a specific PAF receptor antagonist, blocked the effects of PAF and reduced those of endotoxin on colonic motility and transit time, but did not affect either the endotoxin- or the PAF-induced fecal DM decrease. Indomethacin (10 mg/kg ip) and SC 19220 (5 mg/kg ip) reduced the increased frequency of colonic contractions induced by endotoxin and PAF, and antagonized their effects on MRT and fecal DM. These results indicate that 1) E. coli endotoxin increases both colonic motility and transit, and decreases fecal DM, 2) PAF displays similar effects, 3) the action of endotoxin on colonic motility and transit is partly mediated by PAF and PGs while its secretory effects only depend upon PGs generation.

Platelet-activating factor and interleukin 1 are involved in colonic dysmotility in experimental colitis in rats

BACKGROUND

Intracolonic administration of trinitrobenzene sulfonic acid (TNBS) to rats produces chronic colitis associated with an increased release of eicosanoids, platelet-activating factor (PAF), and interleukins.

METHODS

Motor effects of TNBS on proximal colon were evaluated electromyographically in rats. Mediator involvement was investigated using eicosanoids and PAF antagonists.

RESULTS

The colonic myoelectrical activity was 59 +/- 17 spike bursts per hour lasting 6.9 +/- 1.3 seconds. Two to eight days after TNBS treatment, spike-burst duration was significantly (P < 0.05) higher, with a maximal 1.5-4-fold enhancement at day 3. These alterations were significantly (P < 0.05) reduced by daily treatment with MK-886, a 5-lipoxygenase inhibitor (10 mg/kg, orally), whereas indomethacin (1 mg/kg per day, intramuscularly) was ineffective. At day 3, RP55778, a PAF antagonist (45, 60 mg/kg, intraperitoneally), and rIRAP, an interleukin 1 antagonist (0.3 mg/kg, intraperitoneally) but not KT1-32, a thromboxane A2 antagonist (30, 60 mg/kg orally), nor SKF104,353, a leukotriene D4 antagonist (2, 4 mg/kg, orally), significantly (P < 0.05) reduced the TNB-induced motor effects.

CONCLUSION

TNBS-induced colitis in rats involves a delayed long-lasting dysmotility involving PAF, interleukin 1, and some leukotrienes but not leukotriene D4, thromboxane A2, or other cyclo-oxygenase products.

[Primary intraventricular hemorrhage in a patient with unilateral moyamoya disease]

According to the diagnostic criteria currently in use, the so-called "unilateral" forms of the moyamoya disease, or rather those in which the disorders of the disease itself--such as occlusion of the internal supraclinoid carotid artery or its terminal branches and development of abnormal collateral circulation in the region of the basal ganglia--are only found in one hemisphere and should be considered as "probable" forms of the disease with a much lower incidence than the bilateral or "defined" forms of the same. One patient with a primary intraventricular hemorrhage (PIVH) in whom an occlusion of the right internal carotid artery was angiographically demonstrated and in whom collateral type moyamoya circulation was found as was the presence of an aneurysm in the right coroid territory is presented. The association of PIVH, unilateral moyamoya disease and aneurysm is infrequent in the literature, with the origin of the bleeding, in some cases, having been attributed to rupture of the aneurysm. Since angiographic control was not available in the patient presented it cannot be excluded that the aneurysm was really a pseudoaneurysm therefore being a consequence, rather than a cause, of the arterial rupture. Thus one of the other mechanisms proposed must be invoked to explain the pathogenesis of the PIVH: rupture of a perforating artery or of a microaneurysm located in the subependimary periventricular region. The treatment recommended for these case of PIVH associated to aneurysm is chirurgical if persistence is demonstrated in successive arteriographies.

Mouse macrophage receptor for acetylated low density lipoprotein: demonstration of a fully functional subunit in the membrane and with purified receptor

The functional molecular mass of the macrophage receptor for acetylated low density lipoprotein (Ac-LDL) was determined in membranes by radiation inactivation analysis. Membranes from tumors induced by the mouse macrophage cell line P388D1 were frozen and irradiated with high-energy electrons. Residual binding activity indicated a minimum functional molecular mass of 35,000 Da, considerably smaller than the active 260,000 M(r) protein seen on ligand blots under nonreducing conditions. Scatchard analysis of receptor binding gave no evidence of partially inactivated molecules. The receptor protein, purified by affinity chromatography and preparative gel electrophoresis, was incubated with dithiothreitol (0.1-100 mM) and retested for binding activity. Active subunits of 158,000 and 80,000 M(r) could be demonstrated by ligand blotting, with quantitative conversion of binding activity to the 80,000 M(r) species at 10 mM dithiothreitol. At 100 mM dithiothreitol, all binding activity was lost. Further size reduction was not detected by silver staining. These data suggest that the isolated mouse macrophage Ac-LDL receptor is a trimer with one class of SH groups involved in trimerization and another in the actual binding site. The monomeric species is fully active in vitro under mild reducing conditions. The radiation inactivation data also suggest that each monomeric unit is fully active and capable of functioning independently in the binding of ligands in the membrane.

Leukotriene D4 participates in colonic transit disturbances induced by intracolonic administration of trinitrobenzene sulfonic acid in rats

The effects of colonic inflammation induced by trinitrobenzene sulfonic acid and influence of previous treatment with specific antagonists of inflammatory mediators (platelet-activating factor, leukotrienes, prostaglandins, and thromboxanes) on colonic transit were examined in conscious rats which were permanently fitted with an intracolonic catheter inserted into the proximal colon. Colonic inflammation was induced by intracolonic administration of trinitrobenzene acid (80 mg/kg) in 50% ethanol. Colonic transit time was evaluated by intracolonic administration of a radiolabeled marker [( 51Cr]sodium chromate) and collection of the feces per hour on a conveyor belt. Excretion of the marker was then plotted vs. time, permitting calculations of the times elapsed to recover 25%, 50%, and 75% of the marker injected (T25, T50, and T75, respectively). In control (saline) animals, excretion of the marker described a regular sigmoid curve with 50% of the marker recovered at 6.92 +/- 0.40 hours after intracolonic administration (T25 = 6.4 +/- 0.43 hours; T75 = 7.49 +/- 0.39 hours). Ethanol (vehicle), 50%, did not modify the profile of marker recovery. On the contrary, single intracolonic administration of trinitrobenzene sulfonic acid/ethanol induced a biphasic response consisting of an early pool of radiolabeled feces (T25 = 4.03 +/- 0.55 hours) with a delayed total one (T50 = 11.74 +/- 0.83 hours; T75 = 13.70 +/- 0.49 hours). Antagonists of the leukotriene pathway, i.e., MK = 886, a lipoxygenase inhibitor, and SKF 104,353 and SR 2640, two different leukotriene D4 receptor antagonists, blocked the effects of trinitrobenzene sulfonic acid on colonic transit time and restored a control profile of radiolabeled marker excretion. In contrast, indomethacin, a cyclooxygenase inhibitor, and SC 19220, a specific prostaglandin E2 receptor antagonist, were inefficient in blocking the effects of trinitrobenzene sulfonic acid on colonic transit time. Specific thromboxane A2 receptor antagonists, KT1-32 and GR 32191B, did not show any improvement in colonic transit after trinitrobenzene sulfonic acid administration. Previous injection of the specific platelet-activating factor receptor antagonists, BN 52021 or BN 50730, was also unable to restore a normal marker excretion profile after administration of trinitrobenzene sulfonic acid. It is concluded that the alterations of colonic transit immediately observed after intracolonic trinitrobenzene sulfonic acid administration are mediated through the release of leukotriene D4. In contrast, platelet-activating factor, prostaglandins, and thromboxanes are not involved in the mediation of these transit disturbances.

Myoelectric intestinal disturbances in Escherichia coli endotoxic shock in rats. Involvement of platelet-activating factor

Administration of BN 52021 (50 mg/kg i.v.), a specific antagonist of platelet-activating factor (PAF), significantly reduced the intestinal myoelectric disturbances induced by E. coli endotoxin injection (50 micrograms/kg i.v.) by 62%. Thus, PAF may be involved in the intestinal motor alterations observed in endotoxic shock. When given in combination with indomethacin (10 mg/kg i.p.), BN 52021 inhibited endotoxic shock intestinal disturbances. Indomethacin alone also reduced PAF induced (25 micrograms/kg i.p.) disruption of migrating myoelectric complexes. Endotoxins may act on intestinal motility via release of endogenous PAF and prostaglandins, the effects of PAF being mediated through the release of prostaglandins.