Localization of the gene encoding the α2 subunit of the human VLA-2 receptor to chromosome 5q23-31

The ₂ subunit of the VLA-2 receptor (CD49B) was mapped to human chromosome 5 by several independent approaches. First, the expression of the ₂ subunit at the protein level was investigated in a panel of human-mouse hybrid cell lines. Cell surface expression was detected by indirect immunofluorescence with monoclonal anti-₂ antibody 12F1. Intracellular ₂ antigen was detected by immunostaining of whole cell extracts or of immunoprecipitated 12F1 antigen with the monoclonal antibodies 3H8 and 5C5. Second, the presence of human genomic ₂ sequences in the panel of human-mouse hybrids was detected by PCR, using primers derived from the published ₂ cDNA sequence. The specificity of the amplification product was shown by direct sequencing. The results of the PCR study were confirmed by amplifying aCD14 gene fragment, known to map to chromosome 5. Finally, in situ hybridization with a³H-labeled 1040-bp cDNA probe, also obtained by PCR, confirmed and refined the localization ofCD49B on chromosome 5 at q23-31.     

Suppression of desynchronized sleep through microinjection of the α 2-adrenergic agonist clonidine in the dorsal pontine tegmentum of the cat

The relationships between sleep-waking states and the activity of the noradrenergic system are controversial. In particular, according to an influential model of desynchronized sleep (DS) generation, the arrest of firing of noradrenergic neurons in the locus coeruleus should enhance DS, due to the release from inhibition of executive neurons located in the nearby pontine tegmentum. Since locus coeruleus neurons are strongly inhibited by ₂-adrenergic agonists like clonidine, this agent would be expected to increase DS. Yet clonidine powerfully decreases DS when injected systemically in several species. In this study, clonidine was microinjected locally into the dorsal pontine tegmentum of the cat, a region which comprises anatomically the whole locus coeruleus complex and which plays a key role in the generation of DS. In accord with the results of systemic experiments, bilateral injections of clonidine almost suppressed DS and unilateral injections consistently reduced it. The effects were dose dependent and site specific. It is suggested that clonidine may suppress DS by acting additionally on non-noradrenergic cell groups located in the dorsal pontine tegmentum.     

Impact of the Pla Protease Substrate α2-Antiplasmin on the Progression of Primary Pneumonic Plague

Many pathogens usurp the host hemostatic system during infection to promote pathogenesis. Yersinia pestis, the causative agent of plague, expresses the plasminogen activator protease Pla, which has been shown in vitro to target and cleave multiple proteins within the fibrinolytic pathway, including the plasmin inhibitor α2-antiplasmin (A2AP). It is not known, however, if Pla inactivates A2AP in vivo; the role of A2AP during respiratory Y. pestis infection is not known either. Here, we show that Y. pestis does not appreciably cleave A2AP in a Pla-dependent manner in the lungs during experimental pneumonic plague. Furthermore, following intranasal infection with Y. pestis, A2AP-deficient mice exhibit no difference in survival time, bacterial burden in the lungs, or dissemination from wild-type mice. Instead, we found that in the absence of Pla, A2AP contributes to the control of the pulmonary inflammatory response during infection by reducing neutrophil recruitment and cytokine production, resulting in altered immunopathology of the lungs compared to A2AP-deficient mice. Thus, our data demonstrate that A2AP is not significantly affected by the Pla protease during pneumonic plague, and although A2AP participates in immune modulation in the lungs, it has limited impact on the course or ultimate outcome of the infection.     

Connection types between the spinal root of the accessory nerve and the posterior roots of the C2–C6 spinal nerves

Purpose  The aim of this study was to demonstrate the connection types and frequency between the accessory nerve and the posterior roots of the C2–C6 cervical nerves. Methods  The cranial cervical regions of 49 specimens from 27 human cadavers were used for the present study under an operating microscope. Results  Five different connection types between the accessory nerve and the posterior roots of the cervical nerves were recorded and photographed (types A–F). One of these types was not described previously in literature (type F). All connections between the posterior roots of the C2–C6 spinal nerves and the accessory nerve were at the level of the C2 segment. Type B was the most frequently seen type in our series. One of the rootlets of the cervical posterior root joined the accessory nerve without a connection to the spinal cord in type B. Conclusions  The clinical importance of these connections is especially noticed during the radical neck dissection as it may lead to the development of the shoulder-arm syndrome.     

The performance of the VIKIA(®) HIV1/2 rapid test-evaluation of the reliability and sensitivity

The use of rapid human immunodeficiency virus (HIV) antibody tests can help reduce the number of individuals positive for HIV who are unaware of their infection.Although several studies have demonstrated that the sensitivity and specificity of rapid HIV tests are comparable to those of enzyme immunoassays, none have addressed the rapidity with which these tests can yield a result and the reliability of such results. In this study, we investigated the performance of VIKIA^® HIV1/2 rapid tests regarding early reactive results and the stability of these results after sample addition. The results showed that using HIV-1 or HIV-2 positive samples, a positive result could be observed as early as 1 min after the addition of the sample. The ability of this test to detect early HIV-1 primary infection was also assessed using seroconversion specimens. The results demonstrate the high sensitivity of this test, and its suitability for the identification of seroconversion samples in the context of primary infection with HIV-1.     

Effect of the dephosphorylated core of 2′,5′-oligoadenylate (2′,5′-ApApA) on electrical activity of the snail neuron

Bulletin of Experimental Biology and Medicine -     

Does loss of hormonal receptors influence the pathophysiological characteristics of the HER-2 breast cancer phenotype?

Background

Some breast carcinomas (BC) of the HER-2 type respond poorly to endocrine therapy, indicating that hormonal receptor (HR) status possibly impacts the biological criteria of this tumor class. The aim of this study was to compare the clinicopathological characteristics of HR-positive and HR-negative tumors occurring in HER-2 and non-HER-2 BC.

Effects of the dihydropyridine receptor subunits γ and α2δ on the kinetics of heterologously expressed L-type Ca2+ channels

Ba2+ currents through L-type Ca2+ channels were measured in tsA201 cells transiently transfected with expression vectors encoding the dihydropyridine (DHP) receptor subunits alpha1C, beta1a-GFP, alpha2delta and gamma. The subunit effect on channel function was studied by omitting either alpha2delta or gamma from the transfection mixture and analyzing the voltage dependence and kinetics of activation, inactivation and recovery from inactivation. Activation could be described by a single exponential function while the time course of inactivation of the Ba2+ current followed a double exponential function. Progressively longer depolarization led to increasingly slower recovery, indicating the successive occupancy of several inactive states. Activation parameters remained largely unaffected in y-deficient cells whereas the voltage dependence of inactivation was shifted by 16 mV to more positive potentials and the larger one of the two inactivation time constants was increased by one-third. On the other hand, alpha2delta-deficient cells showed decreased current density and slowed activation and inactivation. Recovery from inactivation was significantly slowed by gamma coexpression. This and the effect of the gamma subunit on steady-state inactivation were independent of the presence of alpha2delta. We conclude that y stabilizes L-type Ca2+ channel inactivation in a way similar to certain Ca(2+)-antagonistic drugs. Alpha2delta is not needed for this effect.     

Reflex regulation of the “spontaneous” activity of the chemoreceptors of the tongue

Summary The spontaneous activity of the chemoreceptors of the frog's tongue was studied during stimulation of the interoceptors of the stomach and of the sympathetic chain. It was found to be under the control of the nervous system, adapting the receptors to give improved perception, and it indicates the preparedness of these apparatuses to receive stimuli. Spontaneous activity may be fundamentally a partial principle of the functioning of receptor elements. Further electrophysiological investigations of this problem are proceeding.(Presented by Active Member AMN SSSR P. K. Anokhin) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 55, No. 8, pp. 7–11, August, 1963     

The effects of β-2-microglobulin on the infectivity of murine cytomegalovirus

Summary The role of -2-microglobulin (2m) in murine cytomegalovirus (MCMV) infection of susceptible (H-2^d) and resistant (H-2^k) murine embryo fibroblasts (MEF) and peritoneal macrophages was evaluated using serum-free virus (SF-MCMV). The infectivity of SF-MCMV was significantly lower than virus propagated in serum, although the concentrations of virions were similar. Infection of cells with SF-MCMV was assessed by measuring the proportion of cells expressing viral antigens, the sizes of plaques formed in fibroblast monolayers and TCID₅₀ titers. Infection of susceptible fibroblasts was significantly increased 1.6–4.7 fold by the addition of whole FCS, a<20 kDa FCS fraction, or purified human 2m. These supplements also significantly enhanced infection of susceptible macrophages and increased TCID₅₀ titers by 3.5–10 fold in susceptible MEF. In relatively resistant H-2^k cells, the TCID₅₀ titer and the proportion of cells expressing viral antigens after infection with SF-MCMV were not affected by 2m or FCS, but plaque sizes were increased 2.5–3 fold in resistant BALB.K MEF.When human or murine 2m was added to infected cultures, immunogold electron microscopy revealed these proteins to be always associated extracellularly with the tegument material of disrupted multicapsid virions, but rarely with the envelope of intact virions. However, no murine 2m was found in association with the envelope or tegument of SF-MCMV. These relatively modest effects of 2m which were restricted to genetically susceptible cells, may be due to tegument-bound 2m facilitating infection by capsids, or the stabilisation of the conformation of Class 1 molecules by exogenous 2m, promoting MCMV binding to the target cell.     

What is the real importance of evaluating the expression of c-erbB-2 (HER-2/neu) in carcinoma of the breast and prostate? (A short review)

This minireview covers the key data on biology and clinical implications of the c-erbB-2 oncogene in breast and prostate cancer. The aim was to provide basic information to practically oriented pathologists in order to make a reasonable application of methods for c-erbB-2 overexpression or amplification analysis. The clinical interpretation of c-erbB-2 abnormalities should reflect the complexity of c-erbB-2 mediated regulatory pathway and explain why tumours with overexpression/amplification of c-erbB-2 very often do not respond to therapy using Herceptin.     

Post-translational oxidative modification of β2-glycoprotein I and its role in the pathophysiology of the antiphospholipid syndrome

Vascular thrombosis and/or recurrent miscarriages are the main characteristics defining Antiphospholipid Syndrome (APS). Currently there is no well-defined clinical features and/or laboratory tests that predicts the risk of adverse prognostic outcomes in APS. In this short review, we report the importance of posttranslational modification of beta2 glycoprotein I, the major autoantigen in the APS beta2 glycoprotein I that may, in part, explain possible mechanisms for the generation of auto antibodies to beta2 glycoprotein I. A specific ELISA measuring the level of oxidised beta2 glycoprotein I could be used as a potential new laboratory test - along with other laboratory tests - to more accurately predict the risk of having a clinical event in patients with APS.     

Gender-specific haplotype association of collagen α2 (XI) gene in ossification of the posterior longitudinal ligament of the spine

Among Japanese, ossification of the posterior longitudinal ligament of the spine (OPLL) is a leading cause of myelopathy, showing ectopic bone formation in the paravertebral ligament. We have provided genetic evidence that the collagen α2 (XI) (COL11A2) locus of chromosome 6 constitutes susceptibility for OPLL. Five distinct single nucleotide polymorphisms (SNPs), identified in COL11A2, were combined to construct possible haplotypes by the use of a maximum likelihood program. Estimated haplotype frequency was compared in OPLL patients and non-OPLL controls. We report a gender-specific association of the COL11A2 haplotype with OPLL. The frequency of the most commonly observed haplotype was significantly higher in male patients (P = 0.0003) compared with controls, but not in female patients (P = 0.21). OPLL is predominantly observed in males, with a prevalence ratio of 2 : 1, and our gender-specific associations indicate that genetic factors involving COL11A2 play a specific role in the etiology of OPLL exclusively in males. Received: September 5, 2000 / Accepted: October 2, 2000     

α2-Antiplasmin Is Associated with the Progression of Fibrosis

Systemic sclerosis results in tissue fibrosis due to the activation of fibroblasts and the ensuing overproduction of the extracellular matrix. We previously reported that the absence of α2-antiplasmin (α2AP) attenuated the process of dermal fibrosis; however, the detailed mechanism of how α2AP affects the progression of fibrosis remained unclear. The goal of the present study was to examine the role of α2AP in fibrotic change. We observed significantly higher levels of α2AP expression in the skin of bleomycin-injected systemic sclerosis model mice in comparison with the levels seen in control mice. We also demonstrated that α2AP induced myofibroblast differentiation, and the absence of α2AP attenuated the induction of myofibroblast differentiation. Moreover, we found that connective tissue growth factor induced the expression of α2AP through both the extracellular signal-regulated kinase 1/2 (ERK1/2) and c-Jun N-terminal kinase (JNK) pathways in fibroblasts. Interestingly, α2AP also induced transforming growth factor-β expression through the same pathways, and the inhibition of ERK1/2 and JNK slowed the progression of bleomycin-induced fibrosis. Our findings suggest that α2AP is associated with the progression of fibrosis, and regulation of α2AP expression by the ERK1/2 and JNK pathways may be an effective antifibrotic therapy for the treatment of systemic sclerosis.Systemic sclerosis (SSc) affects the skin and the internal organs, resulting in tissue fibrosis. Although the disease process involves immunological mechanisms, vascular damage, and activation of fibroblasts, the pathogenesis of SSc remains to be further elucidated. Fibrotic diseases are characterized by excessive scarring due to excessive production, deposition, and contraction of the extracellular matrix (ECM). This process usually occurs over many months and years, and can lead to organ dysfunction or death. Connective tissue growth factor (CTGF) is constitutively overexpressed in fibrotic lesions such as in scleroderma,¹ liver,² renal,^3,4 lung,⁵ and pancreatic fibrosis.⁵ CTGF acts as a downstream effecter of at least some of the profibrotic effects of transforming growth factor-β (TGF-ß),⁶ and promotes fibroblast proliferation, myofibroblasts differentiation, matrix production, and granulation tissue formation.^7,8Human and murine α2-antiplasmin (α2AP) are serpins (serine protease inhibitors) with a molecular weight of 65 to 70 kd,⁹ which rapidly inactivate plasmin, resulting in the formation of a stable inactive complex, plasmin-α2AP.¹⁰ Tissue fibrosis is generally considered to arise due to a failure of the normal wound healing response to terminate.¹¹ Previous our studies show that α2AP is associated with the wound healing and the fibrosis.^12,13 In addition, it has been reported that the level of plasmin-α2AP complex in plasma is elevated in SSc patients.¹⁴ These findings suggest that α2AP may be associated with the progression of fibrotic disease, but the physiological roles of α2AP are not precisely understood. We herein report that α2AP plays an important role in the progression of fibrosis.     

Multicenter evaluation of the Panbio™ COVID-19 rapid antigen-detection test for the diagnosis of SARS-CoV-2 infection

ObjectivesThe standard RT-PCR assay for coronavirus disease 2019 (COVID-19) is laborious and time-consuming, limiting testing availability. Rapid antigen-detection tests are faster and less expensive; however, the reliability of these tests must be validated before they can be used widely. The objective of this study was to determine the performance of the Panbio? COVID-19 Ag Rapid Test Device (PanbioRT) (Abbott) in detecting severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in nasopharyngeal swab specimens.MethodsThis prospective multicentre study was carried out in ten Spanish university hospitals and included individuals with clinical symptoms or epidemiological criteria of COVID-19. Only individuals with ≤7 days from the onset of symptoms or from exposure to a confirmed case of COVID-19 were included. Two nasopharyngeal samples were taken to perform the PanbioRT as a point-of-care test and a diagnostic RT-PCR test.ResultsAmong the 958 patients studied, 325 (90.5%) had true-positive results. The overall sensitivity and specificity for the PanbioRT were 90.5% (95%CI 87.5–93.6) and 98.8% (95%CI 98–99.7), respectively. Sensitivity in participants who had a threshold cycle (C_T) < 25 for the RT-PCR test was 99.5% (95%CI 98.4–100), and in participants with ≤5 days of the clinical course it was 91.8% (95%CI 88.8–94.8). Agreement between techniques was 95.7% (κ score 0.90; 95%CI 0.88–0.93).ConclusionsThe PanbioRT performs well clinically, with even more reliable results for patients with a shorter clinical course of the disease or a higher viral load. The results must be interpreted based on the local epidemiological context.