Autologous hematopoietic stem cell transplantation of patients with aggressive relapsing-remitting multiple sclerosis: Danish nation-wide experience

BACKGROUND

Autologous hematopoietic stem cell treatment (AHSCT) is considered an effective treatment option for patients with aggressive relapsing-remitting multiple sclerosis (RRMS). Still there are few randomized and controlled studies of AHSCT to shed light on the safety and efficacy of the treatment, and therefore experiences from single centers are important.

AIM

To describe the Danish experience with AHSCT regarding patient characteristics, safety, and efficacy.

METHOD

Nationwide retrospective single center study of patients with multiple sclerosis (MS) treated with AHSCT.

RESULTS

A total of 32 patients were treated with AHSCT from May 2011 to May 2021. Seven were treated with carmustine, etoposide, cytarabine arabinoside, and melphalan (BEAM) as well as antithymocyte globulin (ATG). Twenty-five patients were treated with cyclophosphamide (CY) and ATG. In the whole cohort, relapse-free survival (RFS) was 77% (95% CI: 64-94%), worsening-free survival (WFS) was 79% (95% CI: 66-96%), MRI event-free survival (MFS) was 93% (95% CI: 85-100%), and no evidence of disease (NEDA-3) was 69% (95% CI: 54-89%) at the end of year two post-AHSCT. We had no treatment related mortality and only few severe adverse events (AEs).

CONCLUSION

AHSCT of patients with aggressive RRMS was an effective and relatively safe treatment with few serious AEs and no mortality in Danish patients.

Magnetic hydrogel particles improve nanopore sequencing of SARS-CoV-2 and other respiratory viruses

Presented here is a magnetic hydrogel particle enabled workflow for capturing and concentrating SARS-CoV-2 from diagnostic remnant swab samples that significantly improves sequencing results using the Oxford Nanopore Technologies MinION sequencing platform. Our approach utilizes a novel affinity-based magnetic hydrogel particle, circumventing low input sample volumes and allowing for both rapid manual and automated high throughput workflows that are compatible with Nanopore sequencing. This approach enhances standard RNA extraction protocols, providing up to 40 × improvements in viral mapped reads, and improves sequencing coverage by 20-80% from lower titer diagnostic remnant samples. Furthermore, we demonstrate that this approach works for contrived influenza virus and respiratory syncytial virus samples, suggesting that it can be used to identify and improve sequencing results of multiple viruses in VTM samples. These methods can be performed manually or on a KingFisher automation platform.

Incidence rates of suicide attempts and self-harm in Europe. What can we learn? A systematic review and meta-analysis

Introduction

Definitions used for suicide attempts and self-harm have been discussed for many years and is used differently in European countries, sometimes even interchangeably. Therefore, it is difficult to compare relevant rates across nations.

Objectives

This study aims at estimating the rate of suicide attempts and self-harm in chosen European countries in the more recent years when distinguishing between applied definitions.

Methods

A systematic search for relevant articles published between 2010-2020 will be performed in databases such as PubMed, Embase, PsycINFO, and Web of Science. Only articles in English or Danish will be included. Data will be collected for all age groups above 15 years of age. The prevalence of suicide attempts and self-harm will be calculated by a random effect model. Subgroup analyses will be performed to compare the rates according to age.

Results

from the performed systematic review and meta-study will be presented at the conference.

Conclusions

The conclusion will be presented when results have been analysed.

Disclosure

No significant relationships.

Multimodal Preventive Trial for Alzheimer's Disease: MIND-ADmini Pilot Trial Study Design and Progress

Background

Interventions simultaneously targeting multiple risk factors and mechanisms are most likely to be effective in preventing cognitive impairment. This was indicated in the Finnish Geriatric Intervention Study to Prevent Cognitive Impairment and Disability (FINGER) testing a multidomain lifestyle intervention among at-risk individuals. The importance of medical food at the early symptomatic disease stage, prodromal Alzheimer’s disease (AD), was emphasized in the LipiDiDiet trial. The feasibility and effects of multimodal interventions in prodromal AD are unclear.

Objectives

To evaluate the feasibility of an adapted FINGER-based multimodal lifestyle intervention, with or without medical food, among individuals with prodromal AD.

Methods

MIND-ADmini is a multinational proof-of-concept 6-month randomized controlled trial (RCT), with four trial sites (Sweden, Finland, Germany, France). The trial targeted individuals with prodromal AD defined using the International Working Group-1 criteria, and with vascular or lifestyle-related risk factors. The parallel-group RCT includes three arms: 1) multimodal lifestyle intervention (nutritional guidance, exercise, cognitive training, vascular/metabolic risk management and social stimulation); 2) multimodal lifestyle intervention+medical food (Fortasyn Connect); and 3) regular health advice/ care (control group). Primary outcomes are feasibility and adherence. Secondary outcomes are adherence to the individual intervention domains and healthy lifestyle changes.

Results

Screening began on 28 September 2017 and was completed on 21 May 2019. Altogether 93 participants were randomized and enrolled. The intervention proceeded as planned.

Conclusions

For the first time, this pilot trial tests the feasibility and adherence to a multimodal lifestyle intervention, alone or combined with medical food, among individuals with prodromal AD. It can serve as a model for combination therapy trials (non-pharma, nutrition-based and/or pharmacological interventions).

Potential Preventive Strategies for Amyotrophic Lateral Sclerosis

It may seem useless to propose preventive measures for a disease without established pathogenesis and successful therapy, such as amyotrophic lateral sclerosis (ALS). However, we will show that ALS shares essential molecular mechanisms with aging and that established anti-aging strategies, such as healthy diet or individually adjusted exercise, may be successfully applied to ameliorate the condition of ALS patients. These strategies might be applied for prevention if persons at ALS risk could be identified early enough. Recent research advances indicate that this may happen soon.

Clinical impact of clonal hematopoiesis in patients with lymphoma undergoing ASCT: a national population-based cohort study

Clonal hematopoiesis of indeterminate potential (CHIP) is suspected of being a risk factor for patients with cancer. This study aimed to assess the clinical consequences of CHIP in patients with lymphoma intended for high-dose chemotherapy and autologous stem-cell transplantation (ASCT) in a population-based setting. We identified 892 lymphoma patients who had undergone stem cell harvest at all transplant centers in Denmark. A total of 565 patients had an available harvest sample, which was analysed for CHIP by next-generation sequencing, and the median follow-up was 9.1 years. Of the patients who were intended for immediate ASCT, 25.5% (112/440) carried at least one CHIP mutation. In contrast to previous single-center studies CHIP was not associated with inferior overall survival (OS) in multivariate analyses. However, patients with mutations in genes of the DNA repair pathway (PPM1D, TP53, RAD21, BRCC3) had a significant inferior OS (HR after 1 year of follow-up 2.79, 95% confidence interval 1.71-4.56; p < 0.0001), which also was evident in multivariate analysis (p = 0.00067). These patients had also increased rates of therapy-related leukemia and admission to intensive care. Furthermore, in patients who did not undergo immediate ASCT, a significant inferior OS of individuals with DNA repair mutations was also identified (p = 0.003).

Cosmological Constraints from Multiple Probes in the Dark Energy Survey

The combination of multiple observational probes has long been advocated as a powerful technique to constrain cosmological parameters, in particular dark energy. The Dark Energy Survey has measured 207 spectroscopically confirmed type Ia supernova light curves, the baryon acoustic oscillation feature, weak gravitational lensing, and galaxy clustering. Here we present combined results from these probes, deriving constraints on the equation of state, w, of dark energy and its energy density in the Universe. Independently of other experiments, such as those that measure the cosmic microwave background, the probes from this single photometric survey rule out a Universe with no dark energy, finding w=-0.80_{-0.11}^{+0.09}. The geometry is shown to be consistent with a spatially flat Universe, and we obtain a constraint on the baryon density of Ω_{b}=0.069_{-0.012}^{+0.009} that is independent of early Universe measurements. These results demonstrate the potential power of large multiprobe photometric surveys and pave the way for order of magnitude advances in our constraints on properties of dark energy and cosmology over the next decade.

Interaction between C-Tb and PPD given concomitantly in a split-body randomised controlled trial

SETTING

Seven tuberculosis (TB) clinics in South Africa.

OBJECTIVE

As both purified protein derivative (PPD) and a Mycobacterium tuberculosis-specific skin test (C-Tb) contain region of difference 1 (RD1) antigens, we conducted a study to evaluate whether there was any interaction between the two during concomitant and separate administration in patients with newly diagnosed culture-positive TB.

DESIGN

Adult patients with active TB (n = 456, 20% human immunodeficiency virus infected) were randomised to receive only C-Tb, only PPD, or concomitant injection of both C-Tb and PPD using the Mantoux technique. Indurations were read after 48-72 h. QuantiFERON^®-TB Gold In-Tube (QFT) was performed in tandem.

RESULTS

Of the 456 study participants, 154 simultaneously received both C-Tb and PPD, 153 only C-Tb and 149 only PPD. There was no effect of concomitant injection of PPD on the mean C-Tb induration (19 mm, 95%CI 17-22 vs. 18 mm, 95%CI 16-21; P = 0.91). In patients with active TB, C-Tb sensitivity (78%) was similar to PPD (81%) and QFT (84%; excluding 82/429 [19%] indeterminate results). All tests showed reduced sensitivity in participants with CD4 <100 cells/μl.

CONCLUSION

In patients with active TB, there was no interaction between C-Tb and PPD during concomitant injection of both agents. Sensitivities were similar for PPD and C-Tb.

Adoptive cell therapy with tumor-infiltrating lymphocytes in patients with metastatic ovarian cancer: a pilot study

Objective:Ovarian cancer (OC) is often diagnosed at an advanced stage with two thirds of patients experiencing recurrent disease with a poor prognosis. Adoptive cell therapy (ACT) with tumor-infiltrating lymphocytes (TIL) has shown curative potential in malignant melanoma, but has only been investigated scarcely in other cancers. In this pilot study, we tested TIL based ACT in patients with metastatic OC. Methods:Six patients with progressive platinum-resistant metastatic OC were treated with an infusion of TIL preceded by standard lymphodepleting chemotherapy and followed by decrescendo intravenous interleukin-2 (IL-2). Primarily, the feasibility and tolerability of the treatment was assessed. Secondarily, disease control rate was described and immune responses against tumor cells were monitored. Results:Treatment was well tolerated with manageable toxicities. Four patients had stable disease for three months and two patients for five months with five patients having a decrease in target lesions. Progression was primarily due to new lesions while target lesions in general remained stable or in regression. Antitumor reactivity was observed in TIL infusion products from five patients but no antitumor reactivity was detectable in peripheral blood lymphocytes collected after treatment. High numbers of infused TIL expressed exhaustion markers including LAG3 and PD-1, and immunostaining of tumor tissue demonstrated substantial MHCII and PD-L1 expression. Conclusions:ACT with TIL in combination with decrescendo IL-2 is feasible in patients with metastatic OC. Early indications of clinical activity were found. However, TIL ACT efficacy was incomplete with possible involvement of the inhibitory immune checkpoint pathways LAG3/MHCII and PD1/PD-L1.

Pentaisomaltose, an Alternative to DMSO. Engraftment of Cryopreserved Human CD34+ Cells in Immunodeficient NSG Mice

Hematopoietic stem cell transplantation often involves the cryopreservation of stem cell products. Currently, the standard cryoprotective agent (CPA) is dimethyl sulfoxide (DMSO), which is known to cause concentration-related toxicity and side effects when administered to patients. Based on promising in vitro data from our previous study using pentaisomaltose (a 1 kDa subfraction of Dextran 1) as an alternative to DMSO for cryopreservation of hematopoietic progenitor cells (HPCs) from apheresis products, we proceeded to a preclinical model and compared the two CPAs with respect to engraftment of human hematopoietic stem and progenitor cells (HSPCs) in the immunodeficient NSG mouse model. Human HPCs from apheresis products were cryopreserved with either pentaisomaltose or DMSO, and the following outcomes were measured: (1) the post-thaw recovery of cryopreserved cells and clonogenic potential of CD34⁺ cells and (2) hematopoietic engraftment in NSG mice. We found that recovery and colony-forming cells data were comparable between pentaisomaltose and DMSO. The engraftment data revealed comparable human CD45⁺ levels in peripheral blood at 8 weeks and bone marrow at 16 weeks post transplantation. Additionally, the frequencies of CD34⁺CD38^low/negative and myeloid/lymphoid cells in the bone marrow were comparable. We here demonstrated that long-term engrafting HSPCs were well preserved in pentaisomaltose and comparable to cells cryopreserved with DMSO. Although a clinical trial is necessary to translate these results into human use, the present data represent an important step toward the replacement of DMSO with a non-toxic alternative.

Effects of Gemfibrozil on Lipids and Haemostasis after Myocardial Infarction

The effects of gemfibrozil on haemostatic variables were studied in 43 survivors of myocardial infarction with serum triglycerides (TG) ≥2 mmol/1 2 weeks prior to randomization. The study was double-blind, placebo-controlled and stratified for chronic betablockade. Twenty-two individuals were given gemfibrozil 600 mg twice daily and 21 individuals received matching placebo. After 8 weeks the TG level was unchanged in the placebo group, whereas a 44% reduction was noted in the gemfibrozil group (p <0.0001). Fibrinogen increased in both groups, while bleeding time and platelet count were unchanged. Clotting factor VH-phospholipid complex decreased in both groups, but the change was more marked and attained statistical significance only in the gemfibrozil group (60% reduction, p <0.01). By DDAVP-stimulated D-Dimer agglutination test 8 in 21 patients in the placebo group (38%) still had reduced fibrinolytic capacity versus none in the gemfibrozil group (p = 0.001). Thus, in this study, gemfibrozil improved reduced fibrinolytic capacity and may have reduced hypercoagulability by lowering the clotting factor VH-phospholipid complex.

Nationwide population-based cohort study to assess risk of surgery for adhesive small bowel obstruction following open or laparoscopic rectal cancer resection

Background

Laparoscopic surgery has been reported to reduce the formation of adhesions following colorectal surgery. The aim of this nationwide cohort study was to investigate the risk of surgery for adhesive small bowel obstruction (SBO) following open and laparoscopic rectal cancer resection.

Methods

Patients undergoing rectal cancer resection between 2005 and 2013 were identified in the Danish Colorectal Cancer Group database. The primary outcome of surgery for adhesive SBO was identified in the Danish National Patient Registry. The risk of surgery for adhesive SBO was estimated as the cumulative incidence proportion, treating death as a competing risk. Cox proportional hazards regression analysis with multivariable adjustment was used to compute hazard ratios (HRs). The secondary outcome was 30‐day mortality after surgery for adhesive SBO.

Results

Of 7657 patients, 340 (4·4 per cent) underwent surgery for adhesive SBO. The 5‐year risk of surgery for adhesive SBO was 4·5 per cent among 4472 patients undergoing open resection and 3·0 per cent among 3185 patients having a laparoscopic resection. Laparoscopic rectal resection was associated with a lower risk of subsequent operation for adhesive SBO (adjusted HR 0·65, 95 per cent c.i. 0·50 to 0·86; P = 0·002). The adjusted HR of mortality after adhesive SBO was 0·84 (0·37 to 1·91; P = 0·671) comparing patients with previous laparoscopic and open resection.

Conclusion

Laparoscopic rectal cancer resection was associated with a decreased risk of surgery for adhesive SBO. There was a substantial difference in 30‐day mortality after surgery for adhesive SBO based on the surgical approach used at the time of rectal resection.

In vitro digestion of purified β-casein variants A(1), A(2), B, and I: effects on antioxidant and angiotensin-converting enzyme inhibitory capacity

Genetic polymorphisms of bovine milk proteins affect the protein profile of the milk and, hence, certain technological properties, such as casein (CN) number and cheese yield. However, reports show that such polymorphisms may also affect the health-related properties of milk. Therefore, to gain insight into their digestion pattern and bioactive potential, β-CN was purified from bovine milk originating from cows homozygous for the variants A(1), A(2), B, and I by a combination of cold storage, ultracentrifugation, and acid precipitation. The purity of the isolated β-CN was determined by HPLC, variants were verified by mass spectrometry, and molar extinction coefficients at λ=280nm were determined. β-Casein from each of the variants was subjected to in vitro digestion using pepsin and pancreatic enzymes. Antioxidant and angiotensin-converting enzyme (ACE) inhibitory capacities of the hydrolysates were assessed at 3 stages of digestion and related to that of the undigested samples. Neither molar extinction coefficients nor overall digestibility varied significantly between these 4 variants; however, clear differences in digestion pattern were indicated by gel electrophoresis. In particular, after 60min of pepsin followed by 5min of pancreatic enzyme digestion, one ≈4kDa peptide with the N-terminal sequence (106)H-K-E-M-P-F-P-K- was absent from β-CN variant B. This is likely a result of the (122)Ser to (122)Arg substitution in variant B introducing a novel trypsin cleavage site, leading to the changed digestion pattern. All investigated β-CN variants exhibited a significant increase in antioxidant capacity upon digestion, as measured by the Trolox-equivalent antioxidant capacity assay. After 60min of pepsin + 120min of pancreatic enzyme digestion, the accumulated increase in antioxidant capacity was ≈1.7-fold for the 4 β-CN variants. The ACE inhibitory capacity was also significantly increased by digestion, with the B variant reaching the highest inhibitory capacity at the end of digestion (60min of pepsin + 120min of pancreatic enzymes), possibly because of the observed alternative digestion pattern. These results demonstrate that genetic polymorphisms affect the digestion pattern and bioactivity of milk proteins. Moreover, their capacity for radical scavenging and ACE inhibition is affected by digestion.

Evaluation of immunodiagnostic potential of ESAT-6 synthetic peptides mixture in Egyptian pulmonary tuberculosis patients

Identification of M. tuberculosis ESAT-6 proteins has enhanced research for developing new specific and reliable in vitro diagnostic tests for pulmonary tuberculosis. The aim of this study was to assess the diagnostic potential of ESAT-6 synthetic overlapping peptides mixture (Pepmix) for diagnosis of pulmonary M. tuberculosis infection in Egypt. IFN-gammaand IL-17 production was assessed in whole-blood culture assay after overnight stimulation with M. tuberculosis crude culture filtrate (CF), purified 38 kDa antigen, and ESAT-6 Pepmix. Concentration of IFN-gamma and IL-17 was evaluated in the culture supernatant by ELISA. Patients with active pulmonary TB patients (n = 37), Tuberculin Skin Test (TST) positive healthy subjects (n = 16) and TST negative healthy subjects (n = 16) were included. Results indicated that IFN-gammaproduction following stimulation with crude CF, and 38 kDa purified antigen was not significantly different between patients and TST+ healthy controls. In contrast, Pepmix clearly distinguished between patients and TST+ healthy subjects with sensitivity of 70.3 % and specificity 96.9 %. The concentration of secreted IL-17 was significantly lower than IFN-gamma, and no statistically significant difference was found between groups. It is concluded that IFN-gamma assay using ESAT-6 Pepmix, as antigenic stimulus, has the potential to rapidly diagnose pulmonary TB infection.

Endovascular treatment of superior vena cava syndrome

AIM

The aim of this study was to report our experience with palliative stent treatment of superior vena cava syndrome.

METHODS

Between January 2008 and December 2009, 30 patients (mean age 60.7 years) were treated with stents because of stenosed superior vena cava. All patients presented clinically with superior vena cava syndrome and according caval stenosis confirmed by computed tomography. The causes of stenoses were non-small cell carcinoma in 22 patients and small cell carcinoma in 8 patients.

RESULTS

In all patients the stents were placed as intended in all patients there was an immediate clinical improvement with considerable reduction in the edema of upper extremities and head. There was, however, continous dyspnea in five patients (17%) and two patients (7%) had persistent visible collateral venous circulations on the upper chest. There were no stent associated complications. All patients were followed clinically till death and the median follow-up period was 2.8 months (15-420 days). During follow-up three cases of stent thrombosis (one complete and two partial thrombosis) were observed.

CONCLUSION

Palliative care with stent implantation for superior vena cava syndrome is a minimal invasive and safe procedure with good clinical effect giving the patients a significant better quality of their residual life.

The ada operon of Mycobacterium tuberculosis encodes two DNA methyltransferases for inducible repair of DNA alkylation damage

The ada operon of Mycobacterium tuberculosis, which encodes a composite protein of AdaA and AlkA and a separate AdaB/Ogt protein, was characterized. M. tuberculosis treated with N-methyl-N'-nitro-N-nitrosoguanidine induced transcription of the adaA-alkA and adaB genes, suggesting that M. tuberculosis mount an inducible response to methylating agents. Survival assays of the methyltransferase defective Escherichia coli mutant KT233 (ada ogt), showed that expression of the adaB gene rescued the alkylation sensitivity. Further, adaB but not adaA-alkA complemented the hypermutator phenotype of KT233. Purified AdaA-AlkA and AdaB possessed methyltransferase activity. These data suggested that AdaB counteract the cytotoxic and mutagenic effect of O(6)-methylguanine, while AdaA-AlkA most likely transfers methyl groups from innocuous methylphosphotriesters. AdaA-AlkA did not possess alkylbase DNA glycosylase activity nor rescue the alkylation sensitivity of the E. coli mutant BK2118 (tag alkA). We propose that AdaA-AlkA is a positive regulator of the adaptive response in M. tuberculosis. It thus appears that the ada operon of M. tuberculosis suppresses the mutagenic effect of alkylation but not the cytotoxic effect of lesions such as 3-methylpurines. Collectively, these data indicate that M. tuberculosis hypermutator strains with defective adaptive response genes might sustain robustness to cytotoxic alkylation DNA damage and confer a selective advantage contributing to host adaptation.

EFNS guidelines for the molecular diagnosis of neurogenetic disorders: motoneuron, peripheral nerve and muscle disorders

OBJECTIVES

These EFNS guidelines on the molecular diagnosis of motoneuron disorders, neuropathies and myopathies are designed to summarize the possibilities and limitations of molecular genetic techniques and to provide diagnostic criteria for deciding when a molecular diagnostic work-up is indicated.

SEARCH STRATEGY

To collect data about planning, conditions and performance of molecular diagnosis of these disorders, a literature search in various electronic databases was carried out and original papers, meta-analyses, review papers and guideline recommendations reviewed.

RESULTS

The best level of evidence for genetic testing recommendation (B) can be found for the disorders with specific presentations, including familial amyotrophic lateral sclerosis, spinal and bulbar muscular atrophy, Charcot-Marie-Tooth 1A, myotonic dystrophy and Duchenne muscular dystrophy. For a number of less common disorders, a precise description of the phenotype, including the use of immunologic methods in the case of myopathies, is considered as good clinical practice to guide molecular genetic testing.

CONCLUSION

These guidelines are provisional and the future availability of molecular-genetic epidemiological data about the neurogenetic disorders under discussion in this article will allow improved recommendation with an increased level of evidence.

Differential induction of functional IgG using the Plasmodium falciparum placental malaria vaccine candidate VAR2CSA

Background

In Plasmodium falciparum malaria endemic areas placental malaria (PM) is an important complication of malaria. The recurrence of malaria in primigravidae women irrespective of acquired protection during childhood is caused by the interaction between the parasite-expressed VAR2CSA antigen and chondroitin sulfate A (CSA) in the placental intervillous space and lack of protective antibodies. PM impairs fetal development mainly by excessive inflammation processes. After infections during pregnancy women acquire immunity to PM conferred by antibodies against VAR2CSA. Ideally, a vaccine against PM will induce antibody-mediated immune responses that block the adhesion of infected erythrocytes (IE) in the placenta.

Principal Findings

We have previously shown that antibodies raised in rat against individual domains of VAR2CSA can block IE binding to CSA. In this study we have immunized mice, rats and rabbits with each individual domain and the full-length protein corresponding to the FCR3 VAR2CSA variant. We found there is an inherently higher immunogenicity of C-terminal domains compared to N-terminally located domains. This was irrespective of whether antibodies were induced against single domains or the full-length protein. Species-specific antibody responses were also found, these were mainly directed against single domains and not the full-length VAR2CSA protein.

Conclusions/Significance

Binding inhibitory antibodies appeared to be against conformational B-cell epitopes. Non-binding inhibitory antibodies reacted highly against the C-terminal end of the VAR2CSA molecule especially the highly polymorphic DBL6ε domain. Differential species-specific induction of antibody responses may allow for more direct analysis of functional versus non-functional B-cell epitopes.

Rhythmic activity in a simulated neuronal network

1. A digital computer has been programmed to simulate a neuronal network consisting of eighty cells with the following characteristics:(a) All cells in the network had a set random probability of discharge when not affected by other cells. The probability of discharge was chosen as one system parameter (PD).(b) Subsequent to the firing of any neurone in the network, a certain number of other neurones underwent a change in their probability of discharge, consisting of an inhibitory period followed by a period of increased excitability. The changes of excitability mimic the changes of the membrane potential recorded for spontaneously rhythmically active cells in the animal thalamus.2. Starting the network, a typical transient response appeared, consisting of a burst-like activity. The initial activity was followed, first by random fluctuations of the number of active cells, later by periods of spontaneous rhythmic activity that had several characteristics in common with the type of spontaneous activity seen in the animal thalamus.3. The parameters which affected the rhythmic activity of the network most strongly were the degree of the post-inhibitory increase of the probability of discharge and the degree of distribution of the inhibition to neighbouring cells.4. The results are compatible with the inhibitory phasing theory advanced by Andersen & Sears (1964) to explain the occurrence of spontaneous rhythmic activity in the animal thalamus. However, before sufficient experimental knowledge is available, it is difficult to establish whether the rhythmic activity in the network is of the same type as that of the animal thalamus.5. A closer study of the parameters governing the behaviour of the simulated network has given indications of some parameters to be more closely investigated in future animal experiments.

Plasmodium falciparum population dynamics in a cohort of pregnant women in Senegal

BACKGROUND

Pregnant women acquire protective antibodies that cross-react with geographically diverse placental Plasmodium falciparum isolates, suggesting that surface molecules expressed on infected erythrocytes by pregnancy-associated malaria (PAM) parasites have conserved epitopes and, that designing a PAM vaccine may be envisaged. VAR2CSA is the main candidate for a pregnancy malaria vaccine, but vaccine development may be complicated by its sequence polymorphism.

METHODS

The dynamics of P. falciparum genotypes during pregnancy in 32 women in relation to VAR2CSA polymorphism and immunity was determined. The polymorphism of the msp2 gene and five microsatellites was analysed in consecutive parasite isolates, and the DBL5epsilon + Interdomain 5 (Id5) part of the var2csa gene of the corresponding samples was cloned and sequenced to measure variation.

RESULTS

In primigravidae, the multiplicity of infection in the placenta was associated with occurrence of low birth weight babies. Some parasite genotypes were able to persist over several weeks and, still be present in the placenta at delivery particularly when the host anti-VAR2CSA antibody level was low. Comparison of diversity among genotyping markers confirmed that some PAM parasites may harbour more than one var2csa gene copy in their genome.

CONCLUSIONS

Host immunity to VAR2CSA influences the parasite dynamics during pregnancy, suggesting that the acquisition of protective immunity requires pre-exposure to a limited number of parasite variants. Presence of highly conserved residues in surface-exposed areas of the VAR2CSA immunodominant DBL5epsilon domain, suggest its potential in inducing antibodies with broad reactivity.

Tau levels do not influence human ALS or motor neuron degeneration in the SOD1G93A mouse

BACKGROUND

The microtubule-associated protein tau is thought to play a pivotal role in neurodegeneration. Mutations in the tau coding gene MAPT are a cause of frontotemporal dementia, and the H1/H1 genotype of MAPT, giving rise to higher tau expression levels, is associated with progressive supranuclear palsy, corticobasal degeneration, and Parkinson disease (PD). Furthermore, tau hyperphosphorylation and aggregation is a hallmark of Alzheimer disease (AD), and reducing endogenous tau has been reported to ameliorate cognitive impairment in a mouse model for AD. Tau hyperphosphorylation and aggregation have also been described in amyotrophic lateral sclerosis (ALS), both in human patients and in the mutant SOD1 mouse model for this disease. However, the precise role of tau in motor neuron degeneration remains uncertain.

METHODS

The possible association between ALS and the MAPT H1/H2 polymorphism was studied in 3,540 patients with ALS and 8,753 controls. Furthermore, the role of tau in the SOD1(G93A) mouse model for ALS was studied by deleting Mapt in this model.

RESULTS

The MAPT genotype of the H1/H2 polymorphism did not influence ALS susceptibility (odds ratio = 1.08 [95% confidence interval 0.99-1.18], p = 0.08) and did not affect the clinical phenotype. Lowering tau levels in the SOD1(G93A) mouse failed to delay disease onset (p = 0.302) or to increase survival (p = 0.557).

CONCLUSION

These findings suggest that the H1/H2 polymorphism in MAPT is not associated with human amyotrophic lateral sclerosis, and that lowering tau levels in the mutant SOD1 mouse does not affect the motor neuron degeneration in these animals.

Co-Infection of cattle with Fasciola hepatica and Mycobacterium bovis- immunological consequences

Fasciola hepatica, the liver fluke, is a common parasite of cattle in much of the world. Previously, we have shown that cattle infected with F. hepatica have altered responsiveness (delayed type hypersensitivity reaction and cytokine responses) to M. bovis BCG infection. We hypothesized that co-infection with F. hepatica would, likewise, alter the immune response of cattle to virulent M. bovis infection, with possible implications for disease diagnosis and disease progression. Our previous work with F. hepatica/M. bovis BCG-infected cattle demonstrated a reduction in interferon (IFN)-gamma responsiveness in co-infected animals. Similar findings are reported here with virulent M. bovis following aerosol infection. The epidemiological significance of these findings, also, require exploration, particularly in view of the considerable resources devoted to the diagnosis and eradication of bovine tuberculosis, and the high prevalence of F. hepatica infection in areas where eradication has proved difficult.

A generic method for assignment of reliability scores applied to solvent accessibility predictions

BACKGROUND

Estimation of the reliability of specific real value predictions is nontrivial and the efficacy of this is often questionable. It is important to know if you can trust a given prediction and therefore the best methods associate a prediction with a reliability score or index. For discrete qualitative predictions, the reliability is conventionally estimated as the difference between output scores of selected classes. Such an approach is not feasible for methods that predict a biological feature as a single real value rather than a classification. As a solution to this challenge, we have implemented a method that predicts the relative surface accessibility of an amino acid and simultaneously predicts the reliability for each prediction, in the form of a Z-score.

RESULTS

An ensemble of artificial neural networks has been trained on a set of experimentally solved protein structures to predict the relative exposure of the amino acids. The method assigns a reliability score to each surface accessibility prediction as an inherent part of the training process. This is in contrast to the most commonly used procedures where reliabilities are obtained by post-processing the output.

CONCLUSION

The performance of the neural networks was evaluated on a commonly used set of sequences known as the CB513 set. An overall Pearson's correlation coefficient of 0.72 was obtained, which is comparable to the performance of the currently best public available method, Real-SPINE. Both methods associate a reliability score with the individual predictions. However, our implementation of reliability scores in the form of a Z-score is shown to be the more informative measure for discriminating good predictions from bad ones in the entire range from completely buried to fully exposed amino acids. This is evident when comparing the Pearson's correlation coefficient for the upper 20% of predictions sorted according to reliability. For this subset, values of 0.79 and 0.74 are obtained using our and the compared method, respectively. This tendency is true for any selected subset.

A randomized controlled trial of R-salbutamol for topical treatment of discoid lupus erythematosus

BACKGROUND

In a recent open pilot trial, R-salbutamol sulphate, a well-known molecule with anti-inflammatory effects, was tested successfully on patients with therapy-resistant discoid lupus erythematosus (DLE).

OBJECTIVES

To compare the efficacy and safety of R-salbutamol cream 0.5% vs. placebo on DLE lesions in a multicentre, double-blinded, randomized, placebo-controlled phase II trial.

METHODS

Thirty-seven patients with at least one newly developed DLE lesion were randomized - 19 to the R-salbutamol cream 0.5% and 18 to placebo - and treated twice daily for 8 weeks. Efficacy was evaluated through scores of erythema, scaling/hypertrophy and induration as well as pain and itching; general improvement scored by the investigator and global improvement scored by patients' assessment were also evaluated.

RESULTS

The mean area under the curve of improvement for scaling/hypertrophy, pain, itching and global patient assessment was significantly better for the actively treated patients as compared with placebo (scaling/hypertrophy, P = 0.0262; pain, P = 0.0238; itching, P = 0.0135; global patient assessment, P = 0.045). Moreover, the percentage of patients without induration was significantly higher in the active group compared with the placebo group (P = 0.013), and a statistically significantly greater decrease in the size of the lesional area was also seen in the overall analysis of the R-salbutamol-treated patients (P = 0.0197). No serious adverse events were reported.

CONCLUSIONS

Application of R-salbutamol cream 0.5% was safe and well tolerated. Statistically significant effects were seen on scaling/hypertrophy, induration, pain and itching as well as patient global assessment, suggesting that R-salbutamol could be a promising new topical therapy alternative for DLE.

Hyperlipidaemia and reduced fibrinolytic activity associated with thromboembolic complications in a family

Although not significantly correlated, the occurrence of reduced fibrinolytic activity and capacity in hyperlipidaemics has often been described. Hyperlipidaemia and reduced fibrinolysis might well enhance the possibility of thromboembolism. Such a coincidence of risk factors has probably caused thrombotic disease in a family, as described in this case report and family investigation.

Hyperlipoproteinaemia and reduced fibrinolytic activity in healthy coronary high-risk men

One hundred and four consecutive men from the non-symptomatic hyperlipoproteinaemic group of the Oslo Study were examined with regard to their fibrinolytic response to venous occlusion of the arm. Sixty-eight per cent showed reduced fibrinolytic activity as compared to 24% of 21 age-matched healthy coronary low-risk men. In the hyperlipoproteinaemic group, 55 individuals had been on a moderate lipid-lowering diet for about 3 years, whereas the other 49 had not (controls). The diet group showed a market tendency towards normalization of their lipoprotein patterns, but this was not significantly associated with normalization of the fibrinolytic activity. Out of 20 men with type IV hyperlipoproteinaemia, 95% showed reduced fibrinolytic activity. The association between hypertriglyceridaemia (type IV hyperlipoproteinaemia) and reduced fibrinolytic activity might possibly be explained by a reduced lipoprotein lipase activity in these individuals.

Serum antibodies to pigeon antigens in smokers and nonsmokers

Antibodies to pigeon antigens were determined by double immunodiffusion and ELISA in 80 pigeon breeders without pigeon breeder's disease. Precipitating antibodies to pigeon serum and droppings were found in 5 and 8%, respectively, of 39 breeders who were smokers and in 46 and 51%, respectively, of 41 breeders who were nonsmokers (p less than 0.001). By ELISA, IgG antibodies to pigeon serum and droppings were detected in 44 and 54%, respectively, of smokers and in 81 and 85%, respectively, of nonsmokers (p less than 0.01). The antibody titres were generally higher in nonsmokers than in smokers. These findings may partly explain why allergic alveolitis occurs most often in nonsmokers.

ECG recording in emergency home visits

During the first half of 1974, 756 emergency home calls have been made by 6 doctors in the City of Oslo. A portable ECG instrument was available at all visits. The visits were unselected as regards complaints. ECG was recorded in 7% of all patients and in 19% of all patients over 60 years of age. The main indication for recording an ECG was chest pain (nearly 2/3 of all recordings). In only a small number of cases did the recording give a definite result as regards diagnosis of management of the case. However, a slight additional benefit was obtained with a majority of the ECG recordings, including what we defined as a phychotherapeutic benefit. The results of this study indicate that the value of a portable electrocardiograph is very limited for emergency home calls in a city.

Increased fibrinolytic potential after diet intervention in healthy coronary high-risk individuals

Twenty healthy individuals (15 men and 5 women) with initial fasting serum triglycerides greater than or equal to 1.80 mmol/l and euglobulin clot lysis time after venous occlusion greater than or equal to 60 min (upper normal limit 45 min) were tested for fibrinolytic response to venous occlusion and intravenous injection of desmopressin (DDAVP), serum lipids, serum glucose and relative body weight before and after a minimum of 3 to a maximum of 12 months' diet intervention. In order to be defined as a good diet responder, at least 20% reduction of the initial serum triglyceride concentration was required. At the end of the study, half of the participants (7 men and 3 women) met the criteria of good diet responders. All of these showed an improved fibrinolytic response to DDAVP injection, and 7 out of 10 had a normalized fibrinolytic response to venous occlusion. We conclude that, through dietary measures with substantial reduction of hypertriglyceridaemia, it is possible to improve and even normalize the fibrinolytic potential.

Autoantibodies and serum immunoglobulins in chronic liver diseases

In a prospective consecutive study, 68 patients with various liver diseases and 67 control persons were examined for the occurrence of smooth muscle antibodies (SMA), antinuclear antibodies (ANA) and mitochondrial antibodies (MTA) of IgG, IgA and IgM class. A determination of serum immunoglobulins (S-IgG, S-IgA and S-IgM) was also performed. IgG-SMA in titres of greater than 80 occurred in 8 of 12 patients (67%) with hepatitis B antigen (HBag)-negative chronic active liver disease (CALD) and not in other diseases. Apart from one patient with primary biliary cirrhosis (PBC), IgG-ANA in titres of greater than 40 were likewise detected only in HBag-negative CALD (33%). The titres of IgG-SMA and IgG-ANA varied analogously with the biochemical liver parametres. There was a mutual exclusion between HBag and IgG-SMA/-ANA in titres of greater than 20, while IgM-SMA occured in titres of 80 in two patients with HBag-positive CALD. The incidence and titres of IgM-SMA and -ANA were not higher than in the controls. IgA-SMA and -ANA were detected only sporadically. The MTA demonstrated were of IgG PCLASS AND TITRES OF GREATER THAN 40 WERE FOUND ONLY IN PATIENTS WITH PBC (4 of 5). Som of the patients in all groups had an increased conenctration of one or more of the serum immunoglobulins. S-IgG levels were found to be significantly higher in CALD than in the other groups

Long-lasting facilitation of synaptic transmission

After tetanization of several hippocampal pathways (10--50 Hz for 5--15 seconds) there is an increased synaptic transmission of long duration (long-lasting facilitation). The present investigation was undertaken on isolated hippocampal slices to study the mechanism of the effect. The transverse hippocampal slice preparation in vitro allows the simultaneous testing of several afferent fibre systems on the same cell or population of cells. Tetanization of one group of afferent fibres to CA1 pyramids was followed by a long-lasting increase of synaptic transmission along the same fibres, whereas a control input line gave unchanged responses. Using the presynaptic volley as an indicator of the number of afferent impulses, the increased synaptic transmission appeared as an increased excitatory postsynaptic potential (EPSP), increased amplitude and reduced latency of the population spike, and an increased probability of firing of single units. Intracellular recording showed increased EPSPs to afferents of the tetanized line, but no lasting change in membrane resistance or in the response to a depolarizing current pulse. Thus, the effect cannot be ascribed to a general postsynaptic excitability increase. The specific changes in the synaptic transmission may be due either to an increased amount of liberated transmitter or to a local postsynaptic change near the tetanized synapses.

Graft rejection after hematopoietic cell transplantation with nonmyeloablative conditioning

Graft rejection after hematopoietic cell transplantation (HCT) with nonmyeloablative conditioning is a rare but serious clinical problem. Graft rejection and salvage therapy in eight patients in a retrospective analysis of 124 consecutive patients is reported. The patients were conditioned with low-dose fludarabine and total body irradiation (TBI). The association of pretransplantation risk factors with rejection and the effect of chimerism and graft-versus-host disease on rejection were analyzed. Overall survival (OS) and progression free survival (PFS) were compared between patients with and without rejection. Retransplantation was performed with increased TBI conditioning for all patients, and with increased mycophenolate mofetil doses for recipients with HLA-identical sibling donors. No known pretransplantation risk factors were confirmed in this study. Rejection episodes were unevenly distributed over time. The storage temperature of the apheresis products was identified as a risk factor for rejection. Storage of the apheresis products at 5 degrees C diminished the risk of rejection. Low donor T cell chimerism at Day +14 significantly increased the risk of rejection. Seven patients were retransplanted. All but one engrafted successfully, but with decreased OS and PFS. Two patients received pentostatin infusion prior to donor lymphocyte infusions in unsuccessful attempts at reversing rejection. Storage temperature and donor chimerism had a significant effect on rejection. Following rejection, patients are at greater risk of dying from infections and progression/relapse of their malignancy. Retransplantation is feasible and well tolerated after HCT with nonmyeloablative conditioning and should be performed without delay in patients with imminent and manifest graft rejection.

Structural insight into epitopes in the pregnancy-associated malaria protein VAR2CSA

Pregnancy-associated malaria is caused by Plasmodium falciparum malaria parasites binding specifically to chondroitin sulfate A in the placenta. This sequestration of parasites is a major cause of low birth weight in infants and anemia in the mothers. VAR2CSA, a polymorphic multi-domain protein of the PfEMP1 family, is the main parasite ligand for CSA binding, and identification of protective antibody epitopes is essential for VAR2CSA vaccine development. Attempts to determine the crystallographic structures of VAR2CSA or its domains have not been successful yet. In this study, we propose 3D models for each of the VAR2CSA DBL domains and we show that regions in the fold of VAR2CSA inter-domain 2 and a PfEMP1 CIDR domain seem to be homologous to the EBA-175 and Pkα-DBL fold. This suggests that ID2 could be a functional domain. We also identify regions of VAR2CSA present on the surface of native VAR2CSA by comparing reactivity of plasma containing anti-VAR2CSA antibodies in peptide array experiments before and after incubation with native VAR2CSA. By this method we identify conserved VAR2CSA regions targeted by antibodies that react with the native molecule expressed on infected erythrocytes. By mapping the data onto the DBL models we present evidence suggesting that the S1+S2 DBL sub-domains are generally surface-exposed in most domains, whereas the S3 sub-domains are less exposed in native VAR2CSA. These results comprise an important step towards understanding the structure of VAR2CSA on the surface of CSA-binding infected erythrocytes.

Individuals living in areas with high Plasmodium falciparum transmission acquire immunity to malaria over time and adults have markedly reduced risk of getting severe disease. However, pregnant women constitute an important exception, and they become more susceptible to malaria during pregnancy. This so called pregnancy-associated malaria (PAM) has severe consequences for both mother and child, and a vaccine would save hundreds of thousands of lives each year. PAM is caused by P. falciparum–infected red blood cells that bind to receptors in the placenta. By binding to the placental tissue, the parasites avoid being filtered though the spleen where they would have been killed. The protein mediating this placental binding is a very large multidomain and variant protein named VAR2CSA. Using structural modeling of VAR2CSA and antibody reagents from women who have had PAM, we show that antibodies tend to bind in similar regions, on one side of the individual VAR2CSA domains. In addition, we show that highly conserved parts of this variant protein are accessible for antibodies. This finding correlates with epidemiological data showing that woman acquire immunity towards PAM relatively fast, and the identification of these epitopes is thus a major step towards a protective vaccine.

Identification of glycosaminoglycan binding regions in the Plasmodium falciparum encoded placental sequestration ligand, VAR2CSA

BACKGROUND

Pregnancy malaria is caused by Plasmodium falciparum-infected erythrocytes binding the placental receptor chondroitin sulfate A (CSA). This results in accumulation of parasites in the placenta with severe clinical consequences for the mother and her unborn child. Women become resistant to placental malaria as antibodies are acquired which specifically target the surface of infected erythrocytes binding in the placenta. VAR2CSA is most likely the parasite-encoded protein which mediates binding to the placental receptor CSA. Several domains have been shown to bind CSA in vitro; and it is apparent that a VAR2CSA-based vaccine cannot accommodate all the CSA binding domains and serovariants. It is thus of high priority to define minimal ligand binding regions throughout the VAR2CSA molecule.

METHODS

To define minimal CSA-binding regions/peptides of VAR2CSA, a phage display library based on the entire var2csa coding region was constructed. This library was screened on immobilized CSA and cells expressing CSA resulting in a limited number of CSA-binding phages. Antibodies against these peptides were affinity purified and tested for reactivity against CSA-binding infected erythrocytes.

RESULTS

The most frequently identified phages expressed peptides residing in the parts of VAR2CSA previously defined as CSA binding. In addition, most of the binding regions mapped to surface-exposed parts of VAR2CSA. The binding of a DBL2X peptide to CSA was confirmed with a synthetic peptide. Antibodies against a CSA-binding DBL2X peptide reacted with the surface of infected erythrocytes indicating that this epitope is accessible for antibodies on native VAR2CSA on infected erythrocytes.

CONCLUSION

Short continuous regions of VAR2CSA with affinity for multiple types of CSA were defined. A number of these regions localize to CSA-binding domains and to surface-exposed regions within these domains and a synthetic peptide corresponding to a peptide sequence in DBL2 was shown to bind to CSA and not to CSC. It is likely that some of these epitopes are involved in native parasite CSA adhesion. However, antibodies directed against single epitopes did not inhibit parasite adhesion. This study supports phage display as a technique to identify CSA-binding regions of large proteins such as VAR2CSA.