Antibodies to calnexin and mutated calreticulin are common in human sera

PURPOSE OF THE STUDY

Calreticulin is an endoplasmic reticulum chaperone protein, which is involved in protein folding and in peptide loading of major histocompatibility complex class I molecules together with its homolog calnexin. Mutated calreticulin is associated with a group of hemopoietic disorders, especially myeloproliferative neoplasms. Currently only the cellular immune response to mutated calreticulin has been described, although preliminary findings have indicated that antibodies to mutated calreticulin are not specific for myeloproliferative disorders. These findings have prompted us to characterize the humoral immune response to mutated calreticulin and its chaperone homologue calnexin.

PATIENTS AND METHODS

We analyzed sera from myeloproliferative neoplasm patients, healthy donors and relapsing-remitting multiple sclerosis patients for the occurrence of autoantibodies to wild type and mutated calreticulin forms and to calnexin by enzyme-linked immunosorbent assay.

RESULTS

Antibodies to mutated calreticulin and calnexin were present at similar levels in serum samples of myeloproliferative neoplasm and multiple sclerosis patients as well as healthy donors. Moreover, a high correlation between antibodies to mutated calreticulin and calnexin was seen for all patient and control groups. Epitope binding studies indicated that cross-reactive antibodies bound to a three-dimensional epitope encompassing a short linear sequence in the C-terminal of mutated calreticulin and calnexin.

CONCLUSION

Collectively, these findings indicate that calreticulin mutations may be common and not necessarily lead to onset of myeloproliferative neoplasm, possibly due to elimination of cells with mutations. This, in turn, may suggest that additional molecular changes may be required for development of myeloproliferative neoplasm.

Inner southern magnetosphere observation of Mercury via SERENA ion sensors in BepiColombo mission

Mercury's southern inner magnetosphere is an unexplored region as it was not observed by earlier space missions. In October 2021, BepiColombo mission has passed through this region during its first Mercury flyby. Here, we describe the observations of SERENA ion sensors nearby and inside Mercury's magnetosphere. An intermittent high-energy signal, possibly due to an interplanetary magnetic flux rope, has been observed downstream Mercury, together with low energy solar wind. Low energy ions, possibly due to satellite outgassing, were detected outside the magnetosphere. The dayside magnetopause and bow-shock crossing were much closer to the planet than expected, signature of a highly eroded magnetosphere. Different ion populations have been observed inside the magnetosphere, like low latitude boundary layer at magnetopause inbound and partial ring current at dawn close to the planet. These observations are important for understanding the weak magnetosphere behavior so close to the Sun, revealing details never reached before.

A novel desmoplakin mutation causes dilated cardiomyopathy with palmoplantar keratoderma as an early clinical sign

Background

PPKs represent a heterogeneous group of disorders with hyperkeratosis of palmar and/or plantar skin. PPK, hair shaft abnormalities, cardiomyopathy and arrhythmias can be caused by mutations in desmosomal genes, e.g. desmoplakin (DSP). PPK should trigger genetic testing to reveal mutations with possible related cardiac disease.

Objectives

To report a large multigenerational family with a novel DSP mutation associated with early‐onset PPK and adult‐onset cardiomyopathy and arrhythmias.

Methods

A custom‐designed in‐house panel of 35 PPK related genes was used to screen mutations in the index patient with focal PPK. The identified DSP mutation was verified by Sanger sequencing. DNA samples from 20 members of the large multigenerational family were sequenced for the DSP mutation. Medical records were reviewed. Clinical dermatological evaluation was performed, including light microscopy of hair samples. Cardiac evaluation included clinical examination, echocardiography, cardiac magnetic resonance imaging (CMR), electrocardiogram (ECG), Holter monitoring and laboratory tests.

Results

We identified a novel autosomal dominant truncating DSP c.2493delA p.(Glu831Aspfs*33) mutation associated with dilated cardiomyopathy (DCM) with arrhythmia susceptibility and focal PPK as an early cutaneous sign. The mutation was found in nine affected family members, but not in any unaffected members. Onset of dermatological findings preceded cardiac symptoms which were variable and occurred at adult age.

Conclusions

We report a novel truncating DSP mutation causing focal PPK with varying severity and left ventricular dilatation and ventricular extrasystoles. This finding emphasizes the importance of genetic diagnosis in patients with PPK for clinical counselling and management of cardiomyopathies and arrhythmias.

SERENA: Particle Instrument Suite for Determining the Sun-Mercury Interaction from BepiColombo

The ESA-JAXA BepiColombo mission to Mercury will provide simultaneous measurements from two spacecraft, offering an unprecedented opportunity to investigate magnetospheric and exospheric particle dynamics at Mercury as well as their interactions with solar wind, solar radiation, and interplanetary dust. The particle instrument suite SERENA (Search for Exospheric Refilling and Emitted Natural Abundances) is flying in space on-board the BepiColombo Mercury Planetary Orbiter (MPO) and is the only instrument for ion and neutral particle detection aboard the MPO. It comprises four independent sensors: ELENA for neutral particle flow detection, Strofio for neutral gas detection, PICAM for planetary ions observations, and MIPA, mostly for solar wind ion measurements. SERENA is managed by a System Control Unit located inside the ELENA box. In the present paper the scientific goals of this suite are described, and then the four units are detailed, as well as their major features and calibration results. Finally, the SERENA operational activities are shown during the orbital path around Mercury, with also some reference to the activities planned during the long cruise phase.

Induction of remission in female rheumatoid arthritis patients is associated with stabilization of myocardial abnormalities: a prospective cardiac magnetic resonance follow-up study

Objectives: To study whether female patients with active rheumatoid arthritis (RA) have myocardial abnormalities and whether progression of myocardial involvement can be attenuated by disease-modifying anti-rheumatic drugs (DMARDs).Method: Cardiac magnetic resonance (cMR; 1.5 or 3.0 T), including late gadolinium enhancement (LGE), T1 relaxation time, and ventricular functions, was performed in 30 patients with untreated active early RA starting first DMARDs, and 28 patients with chronic RA with inadequate response to conventional synthetic DMARDs starting biological DMARDs. cMR was repeated in RA patients 1 year later. cMR was conducted once in 22 fibromyalgia (FM) subjects and in 35 healthy volunteers serving as controls. All subjects were non-smoking females without coronary heart disease, heart failure, or diabetes.Results: Compared with controls, 58 RA patients had slightly lower ventricular function, although in the normal range, and longer T1 time at baseline. None of the FM subjects had LGE, but it was frequent in RA (67%). During the 1 year DMARD treatment, Disease Activity Score based on 28-joint count-C-reactive protein declined, ventricular functions tended to improve, but the number of patients with LGE remained unchanged. However, the number of LGE-positive heart segments either decreased or stayed the same in 91% of RA patients. In early RA patients, achieving tight remission was associated with LGE stabilization, after adjustment for age, metabolic syndrome, baseline inflammatory activity, and leisure-time physical activity.Conclusion: Treatment targeted to tight remission in early stages of RA seems to be important to prevent not only joint damage but also myocardial abnormalities.

The Largest Electron Differential Energy Flux Observed at Mars by the Mars Express Spacecraft, 2004-2016

The goal of this paper is to understand the processes by which solar wind electrons are energized in the Martian magnetosphere and how this compares to processes at Venus and Earth. Each is unique in the source of its magnetic field topology and how this influences electron energization. To achieve this goal, 24 million spectra spanning 13 years have been examined using the electron spectrometer from the Mars Express spacecraft between about 12,000 km and about 250 km altitude, and from all latitudes and local times. The top 10 largest differential energy flux at energies above the differential energy flux peak have been found: seven spectra from the magnetosheath near noon, three from the dark tail (the largest two from the middle and ionospheric edge of the magnetosheath). Spectral comparisons show a decade range in the peak of the electron distributions; however, all distributions show a similar energy maximum dictated by solar wind/planet interaction. Similarly derived, the largest Venus spectrum occurred near the magnetosheath bow shock and had the same shape as the most intense Mars inner magnetosheath spectrum. The Mars and Venus dayside spectra compared to the Mars nightside spectrum that included an enhanced optical signal attributed to discrete "auroral" precipitation show a similar shape. These spectra are also compared to a selected auroral zone electron spectra from the Earth. The Mars and Venus results suggest that there is no more energy needed to generate electrons forming the nightside precipitation than is gained during the solar wind/planet interaction.

Age-adjusted D-dimer cut-off leads to more efficient diagnosis of venous thromboembolism in the emergency department: a comparison of four assays

Essentials Age-adjusted D-dimer cut-offs decrease the false positives in the elderly. Four D-dimer assays were compared in venous thromboembolism outpatients in an emergency ward. Age-adjusted cut-off resulted in improved specificity with maintained sensitivity for all assays. There was a substantial decrease in false positive results, especially in the older population.

SUMMARY

Background The study compares different D-dimer assays and age-adjusted cut-offs in outpatients with suspected venous thromboembolism (VTE). The plasma concentration of this sensitive biomarker is increased by activated coagulation, but also by several conditions that are linked to an increased risk of VTE. One such condition is old age, which poses a common clinical problem where many prefer not to analyze D-dimer in elderly patients. Age-adjusted cut-offs have been validated for both deep venous thrombosis (DVT) and pulmonary embolism, aiming to increase specificity without notably decreasing sensitivity. Objectives We evaluated four common D-dimer assays in parallel, with and without applying age-adjusted cut offs for VTE. Patients/methods The prospective single-center study was conducted in 940 outpatients attending the emergency department with clinically suspected pulmonary embolism or DVT. Four automated D-dimer assays were compared (Siemens INNOVANCE® , Roche Tina-quant, Medirox MRX and STA® -Liatest® D-Di PLUS). Results All assays performed with areas under the ROC curve (AUC) > 0.9 and maintained their sensitivities after implementation of age-adjusted cut-offs. Specificities increased by 6-7% and number needed to test decreased by < 0.3. The rate of false positive results decreased by 6% overall and by 10-20% for patients ≥ 70. Conclusions Age-adjusted cut-offs resulted in maintained high sensitivity and a modest improvement in specificity and number needed to test for all evaluated D-dimer assays. There was a significant reduction in false positive results, which reflects avoidable unnecessary imaging without any compromise of clinical safety. This suggests a potential to benefit the management of VTE in elderly patients, both clinically and economically.

Effects of Formaldehyde on the Nasal Mucosa

To investigate health effects of long-term exposure to formaldehyde a cross-sectional field study was performed. Seventy formaldehyde-exposed workers were compared with a control group. A higher frequency of symptoms from upper and lower airways, headache, and dermal discomfort was found in the formaldehyde-exposed group. Further, formaldehyde-exposed workers showed disturbances of nasal physiologic conditions, such as slow nasal clearance, impairment of the sense of smell, more pronounced nasal mucosal swelling, and by spirometry lower forced vital capacity than expected was found. Nasal biopsies from the concha media showed more frequent histologic changes such as loss of cilia and metaplasia in the formaldehyde-exposed group. Histologic lesions did not correlate to current or cumulative exposure doses to formaldehyde. In an experimental study of Sprague-Dawley rats exposed to formaldehyde (12.7 mg/m3, 6 hours/day, 5 days/week for 24 months), one rat developed a squamous cell carcinoma in the nose and another nasal dysplasia and in seven other rats pronounced nasal metaplasia was seen in the nasal mucosa. In a control group of rats no significant histologic lesions were found.

Pharmacokinetics and Pharmacodynamics of Melagatran, a Novel Synthetic LMW Thrombin Inhibitor, in Patients with Acute DVT

Forty-eight patients with acute proximal deep vein thrombosis (DVT) were randomised to intravenous infusions for 4 to 6 days with melagatran, a novel synthetic low molecular weight thrombin inhibitor, or unfractionated heparin adjusted by the activated partial thromboplastin time (APTT). The aim of the study was to investigate the pharmacokinetics, pharmacodynamics and the safety of melagatran therapy at three different doses. Steady-state plasma concentrations were rapidly achieved and maintained throughout the infusion period. The mean plasma concentrations in the low, medium and high dose groups were 0.17, 0.31 and 0.53 μmol/l, respectively. The prolongation of APTT was stable during the melagatran infusions and correlated to the plasma concentration. Phlebographically verified regression of thrombus size measured as decrease in Marder score was seen after 4 to 6 days in 8 of 12 patients, 6 of 12 patients and 5 of 11 patients in the low, medium and high dose groups of melagatran and in 5 of the heparin-treated patients. In the low dose group with melagatran, thrombus extension was seen in one patient. At the dose levels studied, melagatran was well tolerated with no clinically significant bleeding problems, suggesting that melagatran could safely be given to patients suffering from DVT.

Long-term Clinical Follow-up in 265 Patients with Deep Venous Thrombosis Initially Treated with either Unfractionated Heparin or Dalteparin: A Retrospective Analysis

The primary objective of this retrospective study was to describe the frequency of a post-thrombotic syndrome in 265 patients previously treated for deep venous thrombosis (DVT). The secondary objectives were to document the frequency of recurrent venous thromboembolism (VTE) and mortality, especially from malignant disease. The patients were evaluated 5-14 years after inclusion in three randomized trials comparing continuous intravenous (i. v.) infusion of unfractionated heparin (UFH) (n = 85) with a low molecular weight heparin (LMWH), dalteparin (n = 180). The median post-thrombotic score at follow-up was 2 (range 0-8). In a multiple step-wise regression analysis the post-thrombotic score was significantly higher among patients with initial proximal DVT (p = 0,0001) as compared with those who had distal DVT. A recurrent venous thromboembolic event was diagnosed in 29,4% of the patients treated with dalteparin and in 23,5% of the patients treated with UFH (ns). A secondary risk factor for venous thromboembolism and a longer duration of treatment with oral anticoagulants (OAC) were significantly associated with a lower risk for recurrent VTE, whereas malignant disease diagnosed during follow-up was associated with a higher risk. During follow-up a total of 40,7% of patients had died. No difference in total mortality or mortality from malignant disease was demonstrated between the two drugs. In conclusion, a severe post-thrombotic syndrome occured relatively infrequent. considering the long observation period. Proximal DVT was significantly associated with a more severe post-thrombotic syndrome. After 14 years follow-up, no significant differences were observed in overall mortality, mortality from malignant disease or recurrent VTE between UFH- and dalteparin-treated patients. Malignant disease was a risk factor for recurrent VTE, the presence of a secondary risk factor and a longer duration of treatment with OAC decreased the risk for recurrent VTE.

Mortality caused by intracranial bleeding in non-severe hemophilia A patients

Essentials Data on bleeding-related causes of death in non-severe hemophilia A (HA) patients are scarce. Such data may provide new insights into areas of care that can be improved. Non-severe HA patients have an increased risk of dying from intracranial bleeding. This demonstrates the need for specialized care for non-severe HA patients.

SUMMARY

Background Non-severe hemophilia (factor VIII concentration [FVIII:C] of 2-40 IU dL-1 ) is characterized by a milder bleeding phenotype than severe hemophilia A. However, some patients with non-severe hemophilia A suffer from severe bleeding complications that may result in death. Data on bleeding-related causes of death, such as fatal intracranial bleeding, in non-severe patients are scarce. Such data may provide new insights into areas of care that can be improved. Aims To describe mortality rates, risk factors and comorbidities associated with fatal intracranial bleeding in non-severe hemophilia A patients. Methods We analyzed data from the INSIGHT study, an international cohort study of all non-severe hemophilia A patients treated with FVIII concentrates during the observation period between 1980 and 2010 in 34 participating centers across Europe and Australia. Clinical data and vital status were collected from 2709 patients. We report the standardized mortality rate for patients who suffered from fatal intracranial bleeding, using a general European male population as a control population. Results Twelve per cent of the 148 deceased patients in our cohort of 2709 patients died from intracranial bleeding. The mortality rate between 1996 and 2010 for all ages was 3.5-fold higher than that in the general population (95% confidence interval [CI] 2.0-5.8). Patients who died from intracranial bleeding mostly presented with mild hemophilia without clear comorbidities. Conclusion Non-severe hemophilia A patients have an increased risk of dying from intracranial bleeding in comparison with the general population. This demonstrates the need for specialized care for non-severe hemophilia A patients.

Comparative burden of arthropathy in mild haemophilia: a register-based study in Sweden

INTRODUCTION

Mild haemophilia is a congenital bleeding disorder affecting males. The burden of arthropathy in mild haemophilia has not been comprehensively described.

AIM

The aim of this study was to compare the incidence, age at diagnosis and surgery for arthropathy and related hospitalizations between people with mild haemophilia and the general population in Sweden.

METHODS

This was a register-based cohort study. Eligible participants were those with mild haemophilia born between 1941 and 2008 and a randomly selected, birthdate and sex-matched comparison group from the general population. Follow-up was from birth (or earliest 1984) until death, emigration or end of the study in 2008. Data on arthropathy were obtained from a national patient register. Negative binomial and competing risk regression and Kaplan-Meier estimate curves were used in the analysis.

RESULTS

Overall, 315 people with haemophilia and 1529 people in the comparison group were included. Participants with haemophilia born between 1984 and 2008 had a ninefold (95% CI: 3.3-27.2) and 16-fold (95% CI: 6.7-36.5) increased incidence of arthropathy-related hospital admission and arthropathy diagnosis respectively. None in this cohort underwent surgery. Among participants with haemophilia born prior to 1984, the rates of arthropathy diagnosis and surgery of the index joints (knee, elbow, ankle) were increased twofold (95% CI: 1.0-3.2) and fivefold (95% CI: 1.7-17.8) respectively.

CONCLUSION

Our data suggested a higher burden of arthropathy among individuals with mild haemophilia compared to the general population. Further research should investigate the need for targeted joint screening programmes among individuals with mild haemophilia.

Long-term liver-related morbidity and mortality related to chronic hepatitis C virus infection in Swedish patients with inherited bleeding disorders

INTRODUCTION

Hepatitis C virus (HCV) infection is common in patients with inherited bleeding disorders treated with clotting factor concentrates prior to the introduction of viral inactivation of these products. The long-term consequences of hepatitis C infection in Swedish patients are not fully understood.

AIM

To examine the impact of HCV infection on liver-related morbidity and mortality in Swedish patients with inherited bleeding disorders.

METHODS

We retrospectively collected data on 183 patients with inherited bleeding disorders infected with HCV who attended the Coagulation Unit at Karolinska University Hospital, Sweden. Data regarding end-stage liver disease (ESLD), defined as presence of ascites, encephalopathy, variceal bleeding, hepatocellular carcinoma or liver-related death, were collected from the patient records and the national registers.

RESULTS

The median follow-up time was 35.9 years (IQR 29.0-41.2). A total of 41% had achieved sustained virological response (SVR) after treatment. In total, 14.2% developed ESLD at the median age of 52.6 years (IQR 46.5-64.7). Nineteen (35.8%) of all deaths were due to liver-related causes. Co-infection with human immunodeficiency virus (HIV), older age at time of infection and severe form of bleeding disorder was associated with higher risk of developing ESLD, while SVR was a strong protective factor.

CONCLUSIONS

This study demonstrated that liver-related morbidity and mortality was significant in patients with bleeding disorders and HCV infection in Sweden. Patients with HCV-infection should be candidates for treatment with the new highly effective antiviral drugs, since SVR proved to be a strong protective factor.

Plasma observations during the Mars atmospheric "plume" event of March-April 2012

We present initial analysis and conclusions from plasma observations made during the reported "Mars plume event" of March - April 2012. During this period, multiple independent amateur observers detected a localized, high-altitude "plume" over the Martian dawn terminator [Sanchez-Lavega et al., Nature, 2015, doi:10.1038/nature14162], the cause of which remains to be explained. The estimated brightness of the plume exceeds that expected for auroral emissions, and its projected altitude greatly exceeds that at which clouds are expected to form. We report on in-situ measurements of ionospheric plasma density and solar wind parameters throughout this interval made by Mars Express, obtained over the same surface region, but at the opposing terminator. Measurements in the ionosphere at the corresponding location frequently show a disturbed structure, though this is not atypical for such regions with intense crustal magnetic fields. We tentatively conclude that the formation and/or transport of this plume to the altitudes where it was observed could be due in part to the result of a large interplanetary coronal mass ejection (ICME) encountering the Martian system. Interestingly, we note that the only similar plume detection in May 1997 may also have been associated with a large ICME impact at Mars.

Evaluating outcome of prophylaxis in haemophilia: objective and self-reported instruments should be combined

INTRODUCTION

Routine outcome assessment of prophylaxis should use validated tools, while balancing comprehensiveness and burden. Collecting overlapping information should be avoided.

AIM

To assess correlations between different outcome assessment tools in haemophilia.

METHODS

From an international cross-sectional study, data on objective outcome (Haemophilia Joint Health Score (HJHS 2.1, range 0-124), radiological Pettersson score) and self-reported joint bleeding, Haemophilia Activities List (HAL, range 100-0), health-related quality of life (SF-36, including five physical and five mental domain scores, range 100-0), and Utility (SF6D and EQ-5D, range 1.0-0) were extracted. Spearman's correlations were calculated: ≥0.8 very strong, 0.60-0.79 strong, 0.40-0.59 moderate.

RESULTS

Ninety patients with severe haemophilia, on prophylaxis since median age 3.4 years, were evaluated at median 25.5 years (range 16.0-37.6). Objective outcome was favourable (median HJHS 2.1 6 points, Pettersson score 9 points). Self-reported outcome showed a median of 7 joint bleeds in 5 years, median HAL sum 96 points, high scores for physical domains of SF-36 (median 80-95) and high Utility values (median SF6D 0.87; EQ-5D 0.84). Physical examination (HJHS 2.1) showed strong correlation with radiological scores, moderate correlation with physical domains of the SF-36 and Utility, but no correlation with self-reported bleeding or limitations in activities (HAL). Bleeding was not associated with any other outcome parameter. The HAL was only correlated with the SF36 'Physical functioning' domain.

CONCLUSION

For the evaluation of patients on early prophylaxis, information on bleeding should be complemented by objective joint assessment as well as self-reported limitations in activities and quality of life.

Structural model, physiology and regulation of Slr0006 in Synechocystis PCC 6803

The slr0006 gene of Synechocystis sp. PCC 6803 is upregulated at mRNA and protein level under carbon limitation. The T(N11)A motif in the upstream region of slr0006 is a binding site for transcriptional regulator NdhR, and accumulation of the Slr0006 protein in ndhR deletion mutant grown in high CO2 suggests that NdhR may be a negative regulator of slr0006. Accumulation requires photosynthetic electron transfer, because no Slr0006 was detected in darkness or in the presence of electron transfer inhibitors DCMU and DBMIB. Structural modeling of the Slr0006 protein suggests that it adopts Sua5/YciO/YrdC family fold, which is an α/β twisted open-sheet structure. Similar to the structurally known members of this protein family, the surface of Slr0006 contains positively charged cavity indicating a possible binding site for RNA or nucleotides. Moreover, Slr0006 was co-localized with 30S ribosomal proteins and rRNA, suggesting involvement in processes linked to protein synthesis.

Studies of microparticles in patients with the antiphospholipid syndrome (APS)

OBJECTIVES

To study circulating platelet, monocyte and endothelial microparticles (PMPs, MMPs and EMPs) in patients with antiphospholipid syndrome (APS) in comparison with healthy controls.

MATERIAL AND METHOD

Fifty-two patients with APS and 52 healthy controls were investigated. MPs were measured on a flow cytometer (Beckman Gallios) and defined as particles sized < 1.0 µm, negative to phalloidin, positive to lactadherin and positive to either CD42a (PMPs), CD144 (EMPs) or CD14 (MMPs). Exposure of CD142 (TF) was measured on CD144 positive MPs.

RESULTS

Total number of MPs (i.e. lactadherin positive particles) was higher in APS patients versus controls (p < 0.001). An increased number of EMPs (p < 0.001), increased TF-positive EMPs (p < 0.001) and increased MMPs (p < 0.001) were also observed. PMP numbers did not differ between the groups. None of the MP types differed in numbers between obstetric and thrombotic APS patients.

CONCLUSION

We observed a high number of EMPs expressing TF in APS patients. The numbers of MMPs and total EMPs were also higher as compared with healthy controls but in contrast to previous reports, the number of PMPs did not differ between groups.

A chloroplast-targeted DnaJ protein AtJ8 is negatively regulated by light and has rapid turnover in darkness

The DnaJ proteins (also called as J proteins, J domain proteins or HSP40 proteins) function as molecular co-chaperones for the HSP70 proteins. We assessed the expression of the small chloroplast-targeted DnaJ protein, the AtJ8 protein, by subjecting the wild type Arabidopsis plants to different illumination conditions. It is shown that the expression of the transcripts and proteins of the ATJ8 gene is primarily regulated at the level of transcription. When plants were incubated under high light for 3h, both the transcripts and proteins were completely abolished. Upon transfer of plants to darkness, the transcripts started rapidly accumulating, and subsequently, the AtJ8 protein became visible after 2h in darkness. Conversely, incubation of plants in darkness or under low light intensities induced expression of the ATJ8 transcripts and proteins. Feeding plants with sugars clearly decreased the transcript and protein levels, and incubation with cycloheximide revealed a rapid turnover for AtJ8 in darkness. Moreover, the AtJ8 protein was found to be nearly missing from the var1 mutant, which lacks the FTSH5 protease. It is concluded that AtJ8 is expressed mainly in darkness, is prone to a rapid turnover but is partially stabilized by the FTSH proteases.

Regulatory subunit B'gamma of protein phosphatase 2A prevents unnecessary defense reactions under low light in Arabidopsis

Light is an important environmental factor that modulates acclimation strategies and defense responses in plants. We explored the functional role of the regulatory subunit B'γ (B'γ) of protein phosphatase 2A (PP2A) in light-dependent stress responses of Arabidopsis (Arabidopsis thaliana). The predominant form of PP2A consists of catalytic subunit C, scaffold subunit A, and highly variable regulatory subunit B, which determines the substrate specificity of PP2A holoenzymes. Mutant leaves of knockdown pp2a-b'γ plants show disintegration of chloroplasts and premature yellowing conditionally under moderate light intensity. The cell-death phenotype is accompanied by the accumulation of hydrogen peroxide through a pathway that requires CONSTITUTIVE EXPRESSION OF PR GENES5 (CPR5). Moreover, the pp2a-b'γ cpr5 double mutant additionally displays growth suppression and malformed trichomes. Similar to cpr5, the pp2a-b'γ mutant shows constitutive activation of both salicylic acid- and jasmonic acid-dependent defense pathways. In contrast to cpr5, however, pp2a-b'γ leaves do not contain increased levels of salicylic acid or jasmonic acid. Rather, the constitutive defense response associates with hypomethylation of DNA and increased levels of methionine-salvage pathway components in pp2a-b'γ leaves. We suggest that the specific B'γ subunit of PP2A is functionally connected to CPR5 and operates in the basal repression of defense responses under low irradiance.

Safety and pharmacokinetics of subcutaneously administered recombinant activated factor VII (rFVIIa)

BACKGROUND

 Recombinant activated factor VIIa (rFVIIa) is used to treat bleeds in hemophilia patients with inhibitors. A subcutaneous formulation could potentially improve its half-life and make it suitable for prophylactic treatment.

OBJECTIVES

 A study was conducted to determine the safety of subcutaneously administered rFVIIa in patients with hemophilia and the pharmacokinetic profile (including bioavailability).

PATIENTS/METHODS

 This was a multicenter, open-label, cross-over comparison of single doses of intravenous rFVIIa 90μgkg(-1) and a new formulation of rFVIIa for subcutaneous injection at dose levels of 45, 90, 180, 270 and 360μgkg(-1) . Sixty subjects (12 per dose cohort) with hemophilia A or B were enrolled.

RESULTS

 Subcutaneously administered rFVIIa showed lower mean peak plasma concentrations and prolonged FVII activity (C(max) , 0.44-5.16IU mL(-1) [across doses]; t(1/2) , 12.4h; t(max) , 5.6h) compared with intravenously administered rFVIIa (C(max) , 51.7IUmL(-1) ; t(1/2) , 2.7h; t(max) , <10min). The absolute bioavailability of subcutaneous rFVIIa ranged from 21.1 to 30.1% across dose levels. Dose proportionality was observed within a 2-fold dose increase but not across the full dose range. No thromboembolic events, drug-related serious adverse events, severe injection-site reactions or neutralizing antibodies were reported (primary endpoint). Mild and moderate injection-site reactions were more frequent with subcutaneous than with intravenous injections.

CONCLUSION

 This phase I clinical trial did not identify safety concerns of prolonged exposure to rFVIIa administered subcutaneously in single doses to hemophilia patients.

Two proteins homologous to PsbQ are novel subunits of the chloroplast NAD(P)H dehydrogenase

The PsbQ-like (PQL) proteins 1 and 2, previously shown to be located in the thylakoid lumen of Arabidopsis thaliana, are homologous to PSII oxygen-evolving complex protein PsbQ. Nevertheless, pql mutants showed no defects in PSII but instead the activity of the chloroplast NAD(P)H dehydrogenease (NDH) complex was severely impaired. In line with this observation, the NDH subunits were low in abundance in pql mutants, and, conversely, ndh mutants strongly down-regulated the accumulation of the PQL proteins. In addition, the PQL2 protein was up-regulated in mutant plants deficient in the PSI complex or the thylakoid membrane-bound ferredoxin-NADP(+) oxidoreductase, whereas in pql mutants the PSI complex was slightly up-regulated. Taken together, the two PQL proteins are shown to be novel subunits of the lumenal protuberance of the NDH complex.

Small chloroplast-targeted DnaJ proteins are involved in optimization of photosynthetic reactions in Arabidopsis thaliana

BACKGROUND

DnaJ proteins participate in many metabolic pathways through dynamic interactions with various components of these processes. The role of three small chloroplast-targeted DnaJ proteins, AtJ8 (At1 g80920), AtJ11 (At4 g36040) and AtJ20 (At4 g13830), was investigated here using knock-out mutants of Arabidopsis thaliana. Photochemical efficiency, capacity of CO2 assimilation, stabilization of Photosystem (PS) II dimers and supercomplexes under high light illumination, energy distribution between PSI and PSII and phosphorylation of PSII-LHCII proteins, global gene expression profiles and oxidative stress responses of these DnaJ mutants were analyzed.

RESULTS

Knockout of one of these proteins caused a series of events including a decrease in photosynthetic efficiency, destabilization of PSII complexes and loss of control for balancing the redox reactions in chloroplasts. Data obtained with DNA microarray analysis demonstrated that the lack of one of these DnaJ proteins triggers a global stress response and therefore confers the plants greater tolerance to oxidative stress induced by high light or methyl viologen treatments. Expression of a set of genes encoding enzymes that detoxify reactive oxygen species (ROS) as well as a number of stress-related transcription factors behaved in the mutants at growth light similarly to that when wild-type (WT) plants were transferred to high light. Also a set of genes related to redox regulation were upregulated in the mutants. On the other hand, although the three DnaJ proteins reside in chloroplasts, the expression of most genes encoding thylakoid membrane proteins was not changed in the mutants.

CONCLUSION

It is proposed that the tolerance of the DnaJ protein knockout plants to oxidative stress occurs at the expense of the flexibility of photosynthetic reactions. Despite the fact that the effects of the individual protein knockout on the response of plants to high light treatment are quite similar, it is conceivable that both specific- and cross-talk functions exist between the three small chloroplast-targeted DnaJ proteins, AtJ8, AtJ11 and AtJ20.

Genes regulating molecular and cellular functions in noninfectious nonallergic rhinitis

BACKGROUND

Chronic noninfectious, nonallergic rhinitis (NINAR) is a complex syndrome with a principally unknown pathophysiology. New technology has made it possible to examine differentially expressed genes and according to network theory, genes connected by their function that might have key roles in the disease.

METHODS

Connectivity analysis was used to identify NINAR key genes. mRNA was extracted from nasal biopsies from 12 NINAR patients and 12 healthy volunteers. Microarrays were performed using Affymetrix chips with 54 613 genes. Data were analysed with the Ingenuity Pathway System for organization of genes into annotated biological functions and, thereafter, linking genes into networks due to their connectivity. The regulation of key genes was confirmed with reverse transcription-polymerase chain reaction (RT-PCR).

RESULTS

In all, 43 genes were differentially expressed. The functional analysis showed that these genes were primarily involved in cellular movement, haematological system development and immune response. Merging these functions, 10 genes were found to be shared. Network analysis generated three networks and two of these 'shared genes' in key positions, c-fos and cell division cycle 42 (Cdc42). These genes were upregulated in both the array and the RT-PCR analysis.

CONCLUSION

Ten genes were found to be of pathophysiological interest for NINAR and of these, c-fos and Cdc42 seemed to be of specific interest due to their ability to interact with other genes of interest within this context. Although the role of c-fos and Cdc42 in upper airway inflammation remains unknown, they might be used as potential disease markers.

AtCYP20-2 is an auxiliary protein of the chloroplast NAD(P)H dehydrogenase complex

AtCYP20-2 is one of 16 immunophilins in thylakoid lumen. The presence of the isomerase domain in AtCYP20-2, an enrichment of AtCYP20-2 in the stroma membranes and it's co-migration with NAD(P)H dehydrogenase (NDH) in native gels provide evidence that AtCYP20-2 is an auxiliary protein of NDH. When different NDH mutants were studied, AtCYP20-2 was found to be strongly reduced especially in mutants deficient in the membrane domain of NDH, thus suggesting a role in the assembly of NDH hydrophobic domain. Lack of AtCYP20-2, however, did not lead to severe malfunction of NDH, indicating redundancy in the function of lumenal immunophilins.

Comparison of the electron transport properties of the psbo1 and psbo2 mutants of Arabidopsis thaliana

Genome sequence of Arabidopsis thaliana (Arabidopsis) revealed two psbO genes (At5g66570 and At3g50820) which encode two distinct PsbO isoforms: PsbO1 and PsbO2, respectively. To get insights into the function of the PsbO1 and PsbO2 isoforms in Arabidopsis we have performed systematic and comprehensive investigations of the whole photosynthetic electron transfer chain in the T-DNA insertion mutant lines, psbo1 and psbo2. The absence of the PsbO1 isoform and presence of only the PsbO2 isoform in the psbo1 mutant results in (i) malfunction of both the donor and acceptor sides of Photosystem (PS) II and (ii) high sensitivity of PSII centers to photodamage, thus implying the importance of the PsbO1 isoform for proper structure and function of PSII. The presence of only the PsbO2 isoform in the PSII centers has consequences not only to the function of PSII but also to the PSI/PSII ratio in thylakoids. These results in modification of the whole electron transfer chain with higher rate of cyclic electron transfer around PSI, faster induction of NPQ and a larger size of the PQ-pool compared to WT, being in line with apparently increased chlororespiration in the psbo1 mutant plants. The presence of only the PsbO1 isoform in the psbo2 mutant did not induce any significant differences in the performance of PSII under standard growth conditions as compared to WT. Nevertheless, under high light illumination, it seems that the presence of also the PsbO2 isoform becomes favourable for efficient repair of the PSII complex.

Validation of a composite score for clinical severity of hemophilia

INTRODUCTION

Evaluation of modulators of the phenotypic expression of hemophilia may benefit from a scoring system that reflects several aspects of the clinical severity instead of only one dimension.

METHODS

We describe here how we constructed a composite Hemophilia Severity Score (HSS) and performed validation. The items in the HSS are annual incidence of joint bleeds, World Federation of Hemophilia Orthopedic joint score, and annual factor consumption. The latter two were adjusted for age at start of prophylaxis and body weight. Data for 100 adolescent or adult patients with hemophilia A or B in the mild, moderate or severe form without inhibitors were collected for the 1990-1999 period. We evaluated the reliability (multidimension property, test-retest) and validity (content, convergent, discriminant and known groups) of the score.

RESULTS

The HSS ranged from 0 to 0.94 and was higher in severe hemophilia A than severe hemophilia B (median 0.50 and 0.24; P = 0.031). The validation indicated that the HSS is reliable and reflective of the clinical severity of hemophilia. The presence of factor V G1691A or prothrombin G20210A polymorphisms was found in 13 patients. The clinical severity, measured as the HSS or each of the three components, appeared to be modified by prothrombin G20210A but not by FV G1691A.

CONCLUSION

The HSS is a well-defined tool that provides a comprehensive representation of the clinical severity of hemophilia in adults. It would be useful in larger studies on the assessment of modulators of the phenotypic expression of hemophilia.

Assessment of the effect of endurance training on left ventricular relaxation with magnetic resonance imaging

The purpose of the study was to assess the effect of endurance training on the early diastolic global and regional left ventricular (LV) relaxation with three magnetic resonance imaging (MRI) techniques. Fourteen subjects were examined with MRI before and after 3-month endurance training. Global early diastolic LV myocardial relaxation was assessed with mitral flow velocity mapping and regional LV early myocardial relaxation with myocardial tagging. LV end-diastolic and end-systolic volumes and mass were assessed with cine Magnetic resonance imaging (MRI). Mitral flow velocity mapping analysis revealed that the time to peak early filling shortened after training (before 112+/-32 ms, after 97+/-21, P<0.05), indicating more rapid global early myocardial relaxation. LV mass increased (97+/-19 g, 105+/-18, P<0.01) and end-systolic volume decreased (47+/-11 mL, 42+/-13, P<0.05). According to myocardial tagging analysis early myocardial relaxation in the septum and in the LV lateral wall increased (P<0.05). Regional tagging analysis showed enhanced myocardial relaxation in the basal septum (P<0.05). Global and regional LV early diastolic relaxation improved and physiological LV hypertrophy was found after the exercise training period for 3 months in healthy sedentary subjects.

Post-thrombotic syndrome, recurrence, and death 10 years after the first episode of venous thromboembolism treated with warfarin for 6 weeks or 6 months

BACKGROUND

The influence of the duration of anticoagulant therapy after venous thromboembolism (VTE) on the long-term morbidity and mortality is unclear.

AIM

To investigate the long-term sequelae of VTE in patients randomized to different duration of secondary prophylaxis.

METHODS

In a multicenter trial comparing secondary prophylaxis with vitamin K antagonists for 6 weeks or 6 months, we extended the originally planned 2 years follow-up to 10 years. The patients had annual visits and at the last visit clinical assessment of the post-thrombotic syndrome (PTS) was performed. Recurrent thromboembolism was adjudicated by a radiologist, blinded to treatment allocation. Causes of death were obtained from the Swedish Death Registry.

RESULTS

Of the 897 patients randomized, 545 could be evaluated at the 10 years follow-up. The probability of developing severe PTS was 6% and any sign of PTS was seen in 56.3% of the evaluated patients. In multivariate analysis, old age and signs of impaired circulation at discharge from the hospital were independent risk factors at baseline for development of PTS after 10 years. Recurrent thromboembolism occurred in 29.1% of the patients with a higher rate among males, older patients, those with permanent triggering risk factor - especially with venous insufficiency at baseline - signs of impaired venous circulation at discharge, proximal deep vein thrombosis, or pulmonary embolism. Death occurred in 28.5%, which was a higher mortality than expected with a standardized incidence ratio (SIR) of 1.43 (95% CI 1.28-1.58), mainly because of a higher mortality than expected from cancer (SIR 1.83; 95% CI 1.44-2.23) or from myocardial infarction or stroke (SIR 1.28; 95% CI 1.00-1.56). The duration of anticoagulation did not have a statistically significant effect on any of the long-term outcomes.

CONCLUSION

The morbidity and mortality during 10 years after the first episode of VTE is high and not reduced by extension of secondary prophylaxis from 6 weeks to 6 months. A strategy to reduce recurrence of VTE as well as mortality from arterial disease is needed.

Plasma Acceleration Above Martian Magnetic Anomalies

Auroras are caused by accelerated charged particles precipitating along magnetic field lines into a planetary atmosphere, the auroral brightness being roughly proportional to the precipitating particle energy flux. The Analyzer of Space Plasma and Energetic Atoms experiment on the Mars Express spacecraft has made a detailed study of acceleration processes on the nightside of Mars. We observed accelerated electrons and ions in the deep nightside high-altitude region of Mars that map geographically to interface/cleft regions associated with martian crustal magnetization regions. By integrating electron and ion acceleration energy down to the upper atmosphere, we saw energy fluxes in the range of 1 to 50 milliwatts per square meter per second. These conditions are similar to those producing bright discrete auroras above Earth. Discrete auroras at Mars are therefore expected to be associated with plasma acceleration in diverging magnetic flux tubes above crustal magnetization regions, the auroras being distributed geographically in a complex pattern by the many multipole magnetic field lines extending into space.

Evaluation of low PAI-1 activity as a risk factor for hemorrhagic diathesis

BACKGROUND

Prospective studies of the epidemiology and clinical significance of low plasminogen activator inhibitor type 1 (PAI-1) activity are lacking.

OBJECTIVE

To evaluate the prevalence of low PAI-1 activity in patients with a bleeding tendency in comparison with a normal population.

METHODS

In 586 consecutive patients, referred because of bleeding symptoms, we added analyses of PAI-1 activity and tissue plasminogen activator complex with PAI-1 (t-PA-PAI-1) to the routine investigation, consisting of platelet count, bleeding time, prothrombin time, activated partial thromboplastin time, fibrinogen, factor VIII, von Willebrand factor activity, and antigen. Controls were 100 blood donors and 100 age- and sex-matched healthy individuals. The latter were also evaluated regarding the previous bleeding episodes. The bleeding history was classified as clinically significant or not, and the criteria were fulfilled in 75% of the patients and 18% of the healthy controls.

RESULTS

The routine laboratory investigation of the patients was negative in 57%. Low PAI-1 activity, defined as <1.0 U mL(-1), was found in 23% of the patients and in 13% and 10% of the blood donors and healthy controls, respectively (odds ratio and 95% CI, 2.04; 1.11-3.77 and 2.75; 1.39-5.42, respectively). The difference remained statistically significant after the adjustment for body mass index, use of estrogens, sex and age (odds ratio for patients vs. healthy controls 3.23; 95% CI, 1.22-8.56, P = 0.019). The distribution of the 4G/5G genotypes in the patients was not different from that of two control populations. No specific symptom predicted for low PAI-1, which did not aggravate the clinical picture in association with the other hemostatic defects. Low tPA-PAI-1 was not associated with the increased bleeding tendency.

CONCLUSION

Low PAI-1 activity is common in patients with a bleeding diathesis, but it is a risk factor of minor clinical importance and not associated with specific bleeding manifestations.

Current perspectives on the treatment of nasal polyposis: a Swedish opinion report

This Swedish study group has examined the current knowledge of nasal polyposis with emphasis on different treatment modalities. Polyposis is a multifactorial disease that exists for decades in the majority of cases. Different types of treatment must be considered, focusing on the underlying disease. However, as we only know the specific origin of polyposis in a minority of cases, treatment is usually symptomatic. When making a thorough evaluation of different treatment strategies, it is obvious that there is a real need for more controlled treatment studies which would make the scientific ground more stable when it comes to suggesting medical, surgical or combined treatments.