Vimentin autoantibodies induce platelet activation and formation of platelet-leukocyte conjugates via platelet-activating factor

Anti-vimentin antibodies (AVA) are associated with autoimmunity and solid organ transplantation, conditions associated with vascular disease, but their contribution to disease pathogenesis is unknown. Here, we have examined interactions between AVA (mAb and serum from patients) and various leukocyte populations using whole blood and flow cytometry. Normal blood treated with patient sera containing high AVA-IgM titers or with a vimentin-specific monoclonal IgM led to activation of platelets and other leukocytes, as demonstrated by induced expression of P-selectin, fibrinogen, tissue factor, and formation of platelet:leukocyte (P:L) conjugates and a reduction in platelet counts. This activity was antigen (vimentin)-specific and was not mediated by irrelevant IgM antibodies. Flow cytometry demonstrated that AVA do not bind directly to resting platelets in whole blood, but they bind to approximately 10% of leukocytes. Supernatant, derived from AVA-treated leukocytes, induced platelet activation, as measured by the generation of platelet microparticles, when added to platelet-rich plasma. When AVA were added to whole blood in the presence of CV-6209, a platelet-activating factor (PAF) receptor inhibitor, platelet depletion was inhibited. This suggests that PAF is one of the mediators released from AVA-activated leukocytes that leads to P:L conjugation formation and platelet activation. In summary, AVA bind to leukocytes, resulting in release of a PAF and prothrombotic factor that exert a paracrine-activating effect on platelets. Overall, this proposed mechanism may explain the pathogenesis of thrombotic events in autoimmune diseases associated with AVA.     

Protocadherin PCDH10, involved in tumor progression,is a frequent and early target of promoter hypermethylation in cervical cancer

Cervical cancer (CC) is the second most common cancer in women. Currently, no tractable molecular‐based therapeutic targets exist for patients with invasive CC and no predictive markers of risk assessment for progression of precancerous lesions are identified. New molecular insights into CC pathogenesis are urgently needed. Towards this goal, we first determined the copy number alterations of chromosome 4 and then examined the role of PCDH10 mapped to 4q28 as a candidate tumor suppressor gene. We identified monosomy 4 in 47% of 81 invasive CC studied by SNP array and found that 91% of 130 invasive CC harboring methylation in the promoter region of the PCDH10 gene. We then showed that aberrant promoter hypermethylation of PCDH10 is associated with downregulation of gene expression and cell lines exposed to demethylating agent resulted in profound reactivated gene expression. We also showed that the promoter methylation in the PCDH10 gene occurs at an earliest identifiable stage of low‐grade squamous intraepithelial lesion. Our studies demonstrate that inactivation of PCDH10 may be a critical event in CC progression and form a potentially useful therapeutic target for CC. © 2009 Wiley‐Liss, Inc.     

Role of Wake‐Promoting Basal Forebrain and Adenosinergic Mechanisms in Sleep‐Promoting Effects of Ethanol

Background: Ethanol intake has significant impact on sleep. However, the cellular substrates responsible for sleep promotion following ethanol intake are unknown. The purine nucleoside, adenosine, is responsible for mediating many neuronal and behavioral responses to ethanol. Studies performed in cell cultures suggest that ethanol inhibits equilibrative nucleoside transporter 1 to block the reuptake of adenosine resulting in increased extracellular adenosine. Adenosine also has a pivotal role in sleep regulation. Adenosine acts via A1 receptor to inhibit the wake‐promoting neurons of the basal forebrain (BF) resulting in the promotion of sleep. Is ethanol‐induced sleep associated with the inhibition of the BF wake‐promoting neurons? Do adenosinergic mechanisms in the BF have a role in sleep‐promoting effects of ethanol? Methods: To address these questions, we performed 3 experiments in Sprague–Dawley rats. First, we verified the effect of ethanol on sleep promotion. Second, we evaluated the effect of ethanol on c‐Fos expression (a marker of neuronal activation) in the BF wake‐promoting neurons and third we monitored the effects of A1 receptor blockade in the BF on ethanol‐induced sleep. Results: Significant increase in non‐rapid eye movement (NREM) sleep with a concomitant decrease in wakefulness was observed during the first 12 hours postethanol. REM sleep remained unaffected. Ethanol administration caused a significant decrease in the number of BF wake‐promoting neurons with c‐Fos immunoreactivity. Bilateral microinjections of a selective A1R receptor antagonist 8‐cyclopentyl‐1, 3‐dipropylxanthine into the BF significantly attenuated sleep‐promoting effects of ethanol. Conclusion: These results suggest that the inhibition of BF wake‐promoting neurons by adenosinergic mechanism may be responsible for the sleep promoting effects of ethanol. We believe our study is the first to investigate the cellular mechanisms responsible for the somnogenic effects of ethanol.     

The immunogenicity and efficacy against H5N1 challenge of reverse genetics-derived H5N3 influenza vaccine in ducks and chickens

H5N1 avian influenza viruses are continuing to spread in waterfowl in Eurasia and to threaten the health of avian and mammalian species. The possibility that highly pathogenic (HP) H5N1 avian influenza is now endemic in both domestic and migratory birds in Eurasia makes it unlikely that culling alone will control H5N1 influenza. Because ducks are not uniformly killed by HP H5N1 viruses, they are considered a major contributor to virus spread. Here, we describe a reverse genetics-derived high-growth H5N3 strain containing the modified H5 of A/chicken/Vietnam/C58/04, the N3 of A/duck/Germany/1215/73, and the internal genes of A/PR/8/34. One or two doses of inactivated oil emulsion vaccine containing 0.015 to 1.2 microg of HA protein provide highly efficacious protection against lethal H5N1 challenge in ducks; only the two dose regimen has so far been tested in chickens with high protective efficacy.     

Potato lectin activates basophils and mast cells of atopic subjects by its interaction with core chitobiose of cell-bound non-specific immunoglobulin E

A major factor in non-allergic food hypersensitivity could be the interaction of dietary lectins with mast cells and basophils. Because immunoglobulin E (IgE) contains 10-12% carbohydrates, lectins can activate and degranulate these cells by cross-linking the glycans of cell-bound IgE. The present objective focuses on the effect of potato lectin (Solanum tuberosum agglutinin; STA) for its ability to release histamine from basophils in vitro and mast cells in vivo from non-atopic and atopic subjects. In this study, subjects were selected randomly based on case history and skin prick test responses with food, pollen and house dust mite extracts. Skin prick test (SPT) was performed with STA at 100 microg/ml concentration. Histamine release was performed using leucocytes from non-atopic and atopic subjects and rat peritoneal exudate cells. SPT on 110 atopic subjects using STA showed 39 subjects positive (35%); however, none showed STA-specific IgE; among 20 non-atopic subjects, none were positive by SPT. Maximal histamine release was found to be 65% in atopic subjects (n = 7) compared to 28% in non-atopic subjects (n = 5); the release was inhibited specifically by oligomers of N-acetylglucosamine and correlates well with serum total IgE levels (R(2) = 0.923). Binding of STA to N-linked glycoproteins (horseradish peroxidase, avidin and IgG) was positive by dot blot and binding assay. As potato lectin activates and degranulates both mast cells and basophils by interacting with the chitobiose core of IgE glycans, higher intake of potato may increase the clinical symptoms as a result of non-allergic food hypersensitivity in atopic subjects.     

Listeria monocytogenes meningitis: an uncommon opportunistic infection in HIV/AIDS

OBJECTIVE: To report an interesting case of meningitis caused by Listeria monocytogenes meningitis in an HIV seropositive individual. MATERIALS & METHODS: A previously healthy 45 years old HIV seropositive man, presented with atypical clinical features of meningitis. Blood and Cerebrospinal fluid (CSF) were obtained for biochemical and microbiological investigations. RESULTS: CSF analysis showed pleocytosis with lymphocytic predominance. Gram stain of CSF was negative; however culture yielded growth of gram positive bacilli with tumbling motility. Based on relevant biochemical tests the isolate was identified as Listeria monocytogenes. Patient was treated with i.v. ampicillin and recovered completely. CONCLUSION: Listeriosis is relatively rare in HIV/AIDS among the immunodeficient populations. Atypical clinical and laboratory findings make the diagnosis difficult and these infections may go undiagnosed. Since it is easily treated with readily available antibiotics, it is important to diagnose them at the earliest and thereby prevent treatment failure.     

To study prevalence of persistent pulmonary hypertension in newborn with meconium aspiration syndrome in western Rajasthan,India: a prospective observational study

Aim: To study the prevalence of persistent pulmonary hypertension (PPHN) in newborn with meconium aspiration syndrome (MAS) in western Rajasthan, India.

Material and methods: Hundred full-term newborns who had features of MAS at birth were included in this survey and were evaluated for PPHN using laboratory investigations, including pulse oximetry, ABG, chest X-ray, ECG and 2D color echocardiography.

Results: Nineteen neonates showed PPHN, of them 16 had a shunt reversal at PFO level and the rest at PDA level. Most of these newborns were delivered by emergency cesarean section and were unplanned. A majority of neonates of PPHN (84.21%) were diagnosed within 48?h of life and 73.69% had Downey’s score more than 6. Neonates of PPHN had mean PH 7.21?±?0.07, mean PCO₂ 53.73?±?6.8, mean PaO₂ 61.10?±?10.61 and mean PaO₂/FiO₂ 144.03?±?46.31.

Conclusions: PPHN is a genuine problem in MAS-born neonates and is commonly seen in neonates born by unplanned and unmonitored delivery, and the prevalence of PPHN can be reduced by providing good antenatal care, regular follow up of high-risk pregnancy. 2D echocardiography is an important point of care in the diagnosis of PPHN in nursery and should be promoted in nurseries of developing countries as being engaged in developed countries for more reliable treatment.     

Cytogenetic analysis of 130 renal oncocytomas identify three distinct and mutually exclusive diagnostic classes of chromosome aberrations

The cytogenetic alterations in renal oncocytoma (RO) are poorly understood. We analyzed 130 consecutive RO for karyotypic alterations. Clonal chromosome abnormalities were identified in 63 (49%) cases, which could be categorized into three classes of mutually exclusive cytogenetic categories. Class 1 (N = 20) RO had diploid karyotypes with characteristic 11q13 rearrangement in balanced translocations with 10 or more different chromosome partners in all cases. We identified recurrent translocation partners at 5q35, 6p21, 9p24, 11p13‐14, and 11q23, and confirmed that CCND1 gene rearrangement at 11q13 utilizing fluorescence in situ hybridization (FISH). Class 2 RO (N = 25) exhibited hypodiploid karyotypes with loss of chromosome 1 and/or losses of Y in males and X in females in all cases. The class 3 tumors comprising of 18 cases showed diverse types of abnormalities with the involvement of two or more chromosomes exclusive of abnormalities seen in classes 1 and 2 tumors. Furthermore, karyotypically uninformative cases were subjected to FISH analysis to identify classes 1 and 2 abnormalities. In this group, we found similar frequencies of CCND1 rearrangement, loss of chromosome 1 or Y as with karyotypically abnormal cases. We validated our results against 91 tumors from the Mitelman database. Correlation of clinical data with all the three classes of ROs showed no clear evidence of overall patient survival. Our findings support the hypothesis that RO exhibit three principal cytogenetic categories, which may have different roles in initiation and/or progression. These cytogenetic markers provide a key tool in the diagnostic evaluation of RO.