A network medicine approach to study comorbidities in heart failure with preserved ejection fraction

BACKGROUND

Comorbidities are expected to impact the pathophysiology of heart failure (HF) with preserved ejection fraction (HFpEF). However, comorbidity profiles are usually reduced to a few comorbid disorders. Systems medicine approaches can model phenome-wide comorbidity profiles to improve our understanding of HFpEF and infer associated genetic profiles.

METHODS

We retrospectively explored 569 comorbidities in 29,047 HF patients, including 8062 HFpEF and 6585 HF with reduced ejection fraction (HFrEF) patients from a German university hospital. We assessed differences in comorbidity profiles between HF subtypes via multiple correspondence analysis. Then, we used machine learning classifiers to identify distinctive comorbidity profiles of HFpEF and HFrEF patients. Moreover, we built a comorbidity network (HFnet) to identify the main disease clusters that summarized the phenome-wide comorbidity. Lastly, we predicted novel gene candidates for HFpEF by linking the HFnet to a multilayer gene network, integrating multiple databases. To corroborate HFpEF candidate genes, we collected transcriptomic data in a murine HFpEF model. We compared predicted genes with the murine disease signature as well as with the literature.

RESULTS

We found a high degree of variance between the comorbidity profiles of HFpEF and HFrEF, while each was more similar to HFmrEF. The comorbidities present in HFpEF patients were more diverse than those in HFrEF and included neoplastic, osteologic and rheumatoid disorders. Disease communities in the HFnet captured important comorbidity concepts of HF patients which could be assigned to HF subtypes, age groups, and sex. Based on the HFpEF comorbidity profile, we predicted and recovered gene candidates, including genes involved in fibrosis (COL3A1, LOX, SMAD9, PTHL), hypertrophy (GATA5, MYH7), oxidative stress (NOS1, GSST1, XDH), and endoplasmic reticulum stress (ATF6). Finally, predicted genes were significantly overrepresented in the murine transcriptomic disease signature providing additional plausibility for their relevance.

CONCLUSIONS

We applied systems medicine concepts to analyze comorbidity profiles in a HF patient cohort. We were able to identify disease clusters that helped to characterize HF patients. We derived a distinct comorbidity profile for HFpEF, which was leveraged to suggest novel candidate genes via network propagation. The identification of distinctive comorbidity profiles and candidate genes from routine clinical data provides insights that may be leveraged to improve diagnosis and identify treatment targets for HFpEF patients.

Abstract P3099: Identification Of Hub Genes And Construction Of Protein-protein Interaction (PPI) Network Clusters Define Racially Distinct Signatures Of Ischemic Heart Failure

Cardiovascular diseases, including ischemic heart failure (IHF), are the leading cause of mortality worldwide; furthermore, African Americans (AA) have 30% higher mortality than Caucasian Americans (CA). Our recent study correlates racial differences in socioeconomic status with DNA methylation (DNAm), altered gene expression, and mortality in HF independent of etiology.

The current analysis focused on etiology-specific differences in DNAm with a specific focus on IHF, the related changes in gene expression, within self-reported race. RNA-seq expression ( P < 0.05, ±1.5-fold) and array-based methylation ( P < 0.05, ±5%) profiles were examined using cardiac biopsies from non-IHF (NIHF) and IHF AA (n = 9/5) and CA (n = 10/5) male patients. Network clusters were identified with MCODE (v2.0) and top hub genes identified via Cytohubba (v0.1). Both AA and CA patients showed similar numbers of IHF-specific differentially expressed genes (DEG) (591/365 AA; 439/486 CA; up/down). However, CA-specific methylation changes (29703/22703; up/down) were more abundant compared to AA (2904/2897; up/down). PPI network construction of these changes identified clusters unique to each group. The AA-specific upregulated cluster included AGPAT2, PPARG, and 10 other DEG associated with the fatty acid metabolism, while BMP2, SMAD6, and 4 other DEG that regulate BMP signaling and SMAD phosphorylation were downregulated. The CA-specific upregulated cluster included EZH2, CCNA1, and 18 other DEG that regulate mitotic sister chromatic separation, while EGFR, TNF, and 12 other DEG important for chronic inflammatory response formed the top downregulated cluster. Consistent with greater changes in DNAm the majority of DEGs in CA-specific clusters were also differentially methylated (58%) while fewer were in AA-specific clusters (17%). Within AA-specific PPI networks, PPARG/BMP2 (up/down) were the top ranked hub genes and KIF20A/KIT (up/down) in CA-specific networks. These racially distinct hub genes suggest altered regulatory mechanisms. Our analysis identified racially distinct clusters associated with specific pathways, which may connect the regulators of DNAm to gene expression and IHF, supporting the potential to use this information as prognostic biomarkers.

Prevalence of familial hypercholesterolemia in patients presenting with premature acute coronary syndrome

Background

Familial hypercholesterolemia (FH) is a common genetic disorder responsible for premature and severe cardiovascular morbidity and mortality. The FH prevalence in patients who experienced a premature acute coronary syndrome (ACS) ranges from 5 to 50% according to previous studies and no comparison with FH prevalence in general population are available in those studies.

Purpose

We aimed to assess the prevalence of clinical FH among patients with premature acute myocardial infarction (MI) (age ≤50 years) and to compare it with FH prevalence in a control population (age ≤50 years), coming from the same population pool.

Methods

Patients with diagnosis of premature MI (age ≤50 years) referred to Ambroise Paré hospital from 2014 to 2018 were included. FH prevalence was estimated via the Dutch Lipid Clinic Network score, based on personal and familial history of premature cardiovascular disease, and LDL-cholesterol levels. FH was “possible” with a score between 3 and 5 points, “probable” with a score between 6 and 8 and “definite” with a score &gt;8 and no FH was defined as a score &lt;3. FH prevalence in patients with MI was compared to FH prevalence in a general population (age ≤50 years), coming from the prospective cohort CARVAR 92.

Results

Among the 457 patients with premature MI, 220 (48%) patients had no FH, 208 (46%) had a “possible” FH and 29 (6%) had a “probable” or “definite” FH. In the control population, 9900 subjects aged ≤50 years were identified: 9343 (94.37%) had no FH, 541 (5.46%) had a “possible” FH and 16 (0.16%) had a “probable” or “definite” FH. Considering subjects with “probable” or “definite” FH, FH prevalence was 37.5 times greater among patients with premature MI than in control population (p&lt;0.0001).

Conclusion

Familial hypercholesterolemia is &gt;30-fold more common in patients referred for premature MI than in general population of the same age, coming from the same population pool. This highlights the need for FH diagnosis after a first episode of MI to enhance lipid-lowering therapy and allow an early identification of family members.

Funding Acknowledgement

Type of funding sources: None.

Functional avoidance-based intensity modulated proton therapy with 4DCT derived ventilation imaging for lung cancer

The primary objective is to evaluate the potential dosimetric gains of performing functional avoidance‐based proton treatment planning using 4DCT derived ventilation imaging. 4DCT data of 31 patients from a prospective functional avoidance clinical trial were evaluated with intensity modulated proton therapy (IMPT) plans and compared with clinical volumetric modulated arc therapy (VMAT) plans. Dosimetric parameters were compared between standard and functional plans with IMPT and VMAT with one‐way analysis of variance and post hoc paired student t‐test. Normal Tissue Complication Probability (NTCP) models were employed to estimate the risk of two toxicity endpoints for healthy lung tissues. Dose degradation due to proton motion interplay effect was evaluated. Functional IMPT plans led to significant dose reduction to functional lung structures when compared with functional VMAT without significant dose increase to Organ at Risk (OAR) structures. When interplay effect is considered, no significant dose degradation was observed for the OARs or the clinical target volume (CTV) volumes for functional IMPT. Using fV20 as the dose metric and Grade 2+ pneumonitis as toxicity endpoint, there is a mean 5.7% reduction in Grade 2+ RP with the functional IMPT and as high as 26% in reduction for individual patient when compared to the standard IMPT planning. Functional IMPT was able to spare healthy lung tissue to avoid excess dose to normal structures while maintaining satisfying target coverage. NTCP calculation also shows that the risk of pulmonary complications can be further reduced with functional based IMPT.

P3480Tissue-specific regulation of the mitochondrial proteome by adiponectin receptor 1

Lack of the adiponectin target receptor adiponectin receptor 1 (AdipoR1) impairs gene expression of mitochondrial OXPHOS proteins due to impaired AMPK-SIRT1-PGC-1α signaling. Since decreased adiponectin serum levels in diabetes mellitus should thus compromise AdipoR1 signaling, we hypothesized that impaired AdipoR1 signaling may causally contribute to typically observed mitochondrial defects in diabetes complications. Thus, we performed comparative proteomics in cardiac, renal and hepatic tissue of AdipoR1−/− mice using LC-MS/MS. Using principal component analysis, heatmapping and hierarchical clustering, a significant separation of genotypes was observed across tissues. Enrichment analysis of differentially expressed proteins revealed disproportionate representation of proteins involved in oxidative phosphorylation, TCA cycle and fatty acid oxidation in all tissues. While 121 or 98 or 78 proteins were differentially regulated in cardiac or renal or hepatic tissue, respectively, only 15 proteins were regulated in the same direction across all tissues. Pathway analysis identified HNF4, NRF1, LONP, RICTOR, SURF1, insulin receptor and PGC-1α as most likely upstream regulators. Importantly, we found a dramatic downregulation of AdipoR1 expression in heart (−70%), liver (−90%) and kidney (−80%; all p<0.05) of high fat-fed and prediabetic non-transgenic mice compared to low fat-fed mice. In addition and beyond diabetes, AdipoR1 expression was also decreased in endstage failing hearts of non-diabetic human subjects compared to non-failing donor hearts. Thus, we conclude that AdipoR1 signaling regulates mitochondrial protein composition across all tissues in a functionally conserved, yet molecularly distinct, manner. Impaired AdipoR1 signaling may causally contribute to mitochondrial defects in diabetic complications and even human heart failure.

SAT-163 Prolactin Receptor Signaling Regulates a Pregnancy-Specific Transcriptional Program in Mouse Islets

Pancreatic β-cells undergo profound hyperplasia during pregnancy to maintain maternal euglycemia. Failure to reprogram β-cells into a more replicative state has been found to underlie susceptibility to gestational diabetes (GDM). Our laboratory has recently identified a requirement for prolactin receptor (PRLR) signaling in the metabolic adaptations to pregnancy, where mice lacking β-cell PRLR (βPRLRKO) exhibit a metabolic phenotype consistent with GDM. However, the underlying transcriptional program that is responsible for the PRLR-dependent metabolic adaptations during gestation remains incompletely understood. To identify PRLR signaling gene regulatory networks and target genes within β-cells during pregnancy, we performed a transcriptomic analysis of&nbsp;pancreatic islets isolated from either βPRLRKO mice or littermate controls in late gestation.&nbsp;Gene set enrichment analysis identified Forkhead box protein M1 (Foxm1) and polycomb repressor complex 2 (PRC2) subunits&nbsp;Suz12 and&nbsp;Ezh2 as novel candidate regulators of PRLR-dependent down-regulated and up-regulated genes, respectively. GO-term pathway enrichment revealed both established and novel PRLR signaling target genes that together describe a state of increased cellular metabolism and/or proliferation. In contrast to the requirement for&nbsp;β-cell PRLR signaling in maintaining euglycemia during pregnancy, PRLR target genes were not induced following high-fat-diet feeding. Altogether the current study develops our understanding of genes and transcriptional regulators mediating islet adaptation during pregnancy and suggests pregnancy-specific adaptive mechanisms distinct from those activated by&nbsp;nutritional stress.

Erratum: First Dark Matter Constraints from a SuperCDMS Single-Charge Sensitive Detector [Phys. Rev. Lett. 121, 051301 (2018)]

This corrects the article DOI: 10.1103/PhysRevLett.121.051301.

Glucagon Receptor Signaling Regulates Energy Metabolism via Hepatic Farnesoid X Receptor and Fibroblast Growth Factor 21

Glucagon, an essential regulator of glucose and lipid metabolism, also promotes weight loss, in part through potentiation of fibroblast growth factor 21 (FGF21) secretion. However, FGF21 is only a partial mediator of metabolic actions ensuing from glucagon receptor (GCGR) activation, prompting us to search for additional pathways. Intriguingly, chronic GCGR agonism increases plasma bile acid levels. We hypothesized that GCGR agonism regulates energy metabolism, at least in part, through farnesoid X receptor (FXR). To test this hypothesis, we studied whole-body and liver-specific FXR-knockout (Fxr∆liver) mice. Chronic GCGR agonist (IUB288) administration in diet-induced obese (DIO) Gcgr, Fgf21, and Fxr whole-body or liver-specific knockout (∆liver) mice failed to reduce body weight when compared with wild-type (WT) mice. IUB288 increased energy expenditure and respiration in DIO WT mice, but not Fxr∆liver mice. GCGR agonism increased [14C]palmitate oxidation in hepatocytes isolated from WT mice in a dose-dependent manner, an effect blunted in hepatocytes from Fxr∆liver mice. Our data clearly demonstrate that control of whole-body energy expenditure by GCGR agonism requires intact FXR signaling in the liver. This heretofore-unappreciated aspect of glucagon biology has implications for the use of GCGR agonism in the therapy of metabolic disorders.

First Dark Matter Constraints from a SuperCDMS Single-Charge Sensitive Detector

We present the first limits on inelastic electron-scattering dark matter and dark photon absorption using a prototype SuperCDMS detector having a charge resolution of 0.1 electron-hole pairs (CDMS HVeV, a 0.93 g CDMS high-voltage device). These electron-recoil limits significantly improve experimental constraints on dark matter particles with masses as low as 1  MeV/c^{2}. We demonstrate a sensitivity to dark photons competitive with other leading approaches but using substantially less exposure (0.49 g d). These results demonstrate the scientific potential of phonon-mediated semiconductor detectors that are sensitive to single electronic excitations.

Results from the Super Cryogenic Dark Matter Search Experiment at Soudan

We report the result of a blinded search for weakly interacting massive particles (WIMPs) using the majority of the SuperCDMS Soudan data set. With an exposure of 1690 kg d, a single candidate event is observed, consistent with expected backgrounds. This analysis (combined with previous Ge results) sets an upper limit on the spin-independent WIMP-nucleon cross section of 1.4×10^{-44} (1.0×10^{-44})  cm^{2} at 46  GeV/c^{2}. These results set the strongest limits for WIMP-germanium-nucleus interactions for masses >12  GeV/c^{2}.

New Results from the Search for Low-Mass Weakly Interacting Massive Particles with the CDMS Low Ionization Threshold Experiment

The CDMS low ionization threshold experiment (CDMSlite) uses cryogenic germanium detectors operated at a relatively high bias voltage to amplify the phonon signal in the search for weakly interacting massive particles (WIMPs). Results are presented from the second CDMSlite run with an exposure of 70 kg day, which reached an energy threshold for electron recoils as low as 56 eV. A fiducialization cut reduces backgrounds below those previously reported by CDMSlite. New parameter space for the WIMP-nucleon spin-independent cross section is excluded for WIMP masses between 1.6 and 5.5  GeV/c^{2}.

Cesarean delivery is not associated with decreased at-birth fracture rates in osteogenesis imperfecta

Purpose

Osteogenesis imperfecta (OI) predisposes to recurrent fractures. The moderate-to-severe forms of OI present with antenatal fractures and the mode of delivery that would be safest for the fetus is not known.

Methods

We conducted systematic analyses on the largest cohort of individuals (n=540) with OI enrolled to-date in the OI Linked Clinical Research Centers. Self-reported at-birth fracture rates were compared in individuals with OI types I, III, and IV. Multivariate analyses utilizing backward-elimination logistic regression model building were performed to assess the effect of multiple covariates including method of delivery on fracture-related outcomes.

Results

When accounting for other covariates, at-birth fracture rates did not differ based on whether delivery was by vaginal route or by cesarean section (CS). Increased birth weight conferred higher risk for fractures irrespective of the delivery method. In utero fracture, maternal history of OI, and breech presentation were strong predictors for choosing CS for delivery.

Conclusion

Our study, the largest to analyze the effect of various factors on at-birth fracture rates in OI shows that delivery by CS is not associated with decreased fracture rate. With the limitation that the fracture data were self-reported in this cohort, these results suggest that CS should be performed only for other maternal or fetal indications, but not for the sole purpose of fracture prevention in OI.

First direct limits on lightly ionizing particles with electric charge less than e/6

While the standard model of particle physics does not include free particles with fractional charge, experimental searches have not ruled out their existence. We report results from the Cryogenic Dark Matter Search (CDMS II) experiment that give the first direct-detection limits for cosmogenically produced relativistic particles with electric charge lower than e/6. A search for tracks in the six stacked detectors of each of two of the CDMS II towers finds no candidates, thereby excluding new parameter space for particles with electric charges between e/6 and e/200.

Search for low-mass weakly interacting massive particles with SuperCDMS

We report a first search for weakly interacting massive particles (WIMPs) using the background rejection capabilities of SuperCDMS. An exposure of 577 kg days was analyzed for WIMPs with mass <30  GeV/c(2), with the signal region blinded. Eleven events were observed after unblinding. We set an upper limit on the spin-independent WIMP-nucleon cross section of 1.2×10(-42)  cm(2) at 8  GeV/c(2). This result is in tension with WIMP interpretations of recent experiments and probes new parameter space for WIMP-nucleon scattering for WIMP masses <6  GeV/c(2).

A cross-sectional multicenter study of osteogenesis imperfecta in North America - results from the linked clinical research centers

Osteogenesis imperfecta (OI) is the most common skeletal dysplasia that predisposes to recurrent fractures and bone deformities. In spite of significant advances in understanding the genetic basis of OI, there have been no large-scale natural history studies. To better understand the natural history and improve the care of patients, a network of Linked Clinical Research Centers (LCRC) was established. Subjects with OI were enrolled in a longitudinal study, and in this report, we present cross-sectional data on the largest cohort of OI subjects (n = 544). OI type III subjects had higher prevalence of dentinogenesis imperfecta, severe scoliosis, and long bone deformities as compared to those with OI types I and IV. Whereas the mean lumbar spine area bone mineral density (LS aBMD) was low across all OI subtypes, those with more severe forms had lower bone mass. Molecular testing may help predict the subtype in type I collagen-related OI. Analysis of such well-collected and unbiased data in OI can not only help answering questions that are relevant to patient care but also foster hypothesis-driven research, especially in the context of 'phenotypic expansion' driven by next-generation sequencing.

Search for low-mass weakly interacting massive particles using voltage-assisted calorimetric ionization detection in the SuperCDMS experiment

SuperCDMS is an experiment designed to directly detect weakly interacting massive particles (WIMPs), a favored candidate for dark matter ubiquitous in the Universe. In this Letter, we present WIMP-search results using a calorimetric technique we call CDMSlite, which relies on voltage-assisted Luke-Neganov amplification of the ionization energy deposited by particle interactions. The data were collected with a single 0.6 kg germanium detector running for ten live days at the Soudan Underground Laboratory. A low energy threshold of 170  eVee (electron equivalent) was obtained, which allows us to constrain new WIMP-nucleon spin-independent parameter space for WIMP masses below 6  GeV/c2.

Silicon detector dark matter results from the final exposure of CDMS II

We report results of a search for weakly interacting massive particles (WIMPS) with the silicon detectors of the CDMS II experiment. This blind analysis of 140.2 kg day of data taken between July 2007 and September 2008 revealed three WIMP-candidate events with a surface-event background estimate of 0.41(-0.08)(+0.20)(stat)(-0.24)(+0.28)(syst). Other known backgrounds from neutrons and 206Pb are limited to <0.13 and <0.08 events at the 90% confidence level, respectively. The exposure of this analysis is equivalent to 23.4 kg day for a recoil energy range of 7-100 keV for a WIMP of mass 10  GeV/c2. The probability that the known backgrounds would produce three or more events in the signal region is 5.4%. A profile likelihood ratio test of the three events that includes the measured recoil energies gives a 0.19% probability for the known-background-only hypothesis when tested against the alternative WIMP+background hypothesis. The highest likelihood occurs for a WIMP mass of 8.6  GeV/c2 and WIMP-nucleon cross section of 1.9×10(-41)  cm2.

Inhibition of myostatin signaling through Notch activation following acute resistance exercise

Myostatin is a TGFβ family member and negative regulator of muscle size. Due to the complexity of the molecular pathway between myostatin mRNA/protein and changes in transcription, it has been difficult to understand whether myostatin plays a role in resistance exercise-induced skeletal muscle hypertrophy. To circumvent this problem, we determined the expression of a unique myostatin target gene, Mighty, following resistance exercise. Mighty mRNA increased by 6 h (82.9 ± 24.21%) and remained high out to 48 h (56.5 ± 19.67%) after resistance exercise. Further examination of the soleus, plantaris and tibialis anterior muscles showed that the change in Mighty mRNA at 6 h correlated with the increase in muscle size associated with this protocol (R(2) = 0.9996). The increase in Mighty mRNA occurred both independent of Smad2 phosphorylation and in spite of an increase in myostatin mRNA (341.8 ± 147.14% at 3 h). The myostatin inhibitor SKI remained unchanged. However, activated Notch, another potential inhibitor of TGFβ signaling, increased immediately following resistance exercise (83 ± 11.2%) and stayed elevated out to 6 h (78 ± 16.6%). Electroportion of the Notch intracellular domain into the tibialis anterior resulted in an increase in Mighty mRNA (63 ± 13.4%) that was equivalent to the canonical Notch target HES-1 (94.4 ± 7.32%). These data suggest that acute resistance exercise decreases myostatin signaling through the activation of the TGFβ inhibitor Notch resulting in a decrease in myostatin transcriptional activity that correlates well with muscle hypertrophy.

Reversible control of electrochemical properties using thermally-responsive polymer electrolytes

A thermally responsive copolymer is designed to modulate the properties of an electrolyte solution. The copolymer is prepared using pNIPAM, which governs the thermal properties, and acrylic acid, which provides the electrolyte ions. As the polymer undergoes a thermally activated phase transition, the local environment around the acid groups is reversibly switched, decreasing ion concentration and conductivity. The responsive electrolyte is used to control the activity of redox electrodes with temperature.

Mucosal immunization against ovine lentivirus using PEI-DNA complexes and modified vaccinia Ankara encoding the gag and/or env genes

Sheep were immunized against Visna/Maedi virus (VMV) gag and/or env genes via the nasopharynx-associated lymphoid tissue (NALT) and lung using polyethylenimine (PEI)-DNA complexes and modified vaccinia Ankara, and challenged with live virus via the lung. env immunization enhanced humoral responses prior to but not after VMV challenge. Systemic T cell proliferative and cytotoxic responses were generally low, with the responses following single gag gene immunization being significantly depressed after challenge. A transient reduction in provirus load in the blood early after challenge was observed following env immunization, whilst the gag gene either alone or in combination with env resulted in significantly elevated provirus loads in lung. However, despite this, a significant reduction in lesion score was observed in animals immunized with the single gag gene at post-mortem. Inclusion of IFN-gamma in the immunization mixture in general had no significant effects. The results thus showed that protective effects against VMV-induced lesions can be induced following respiratory immunization with the single gag gene, though this was accompanied by an increased pulmonary provirus load.

Lack of risk of transmission of caprine arthritis-encephalitis virus (CAEV) after an appropriate embryo transfer procedure

The aim of this study was to demonstrate that embryo transfer can be used to produce CAEV-free kids from CAEV-infected biological mothers when appropriate procedure is implemented. Twenty-eight goats that had tested positive for CAEV using PCR on vaginal secretions were used as embryo donors. Embryos with intact-ZP were selected and washed 10 times; they were then frozen and used for transfer into CAEV-free recipient goats. Nineteen of the 49 recipient goats gave birth, producing a total of 23 kids. Three blood samples were taken from each recipient goat, 10 days before, during, and 10 days after parturition; these were tested for CAEV antibodies using ELISA and for CAEV proviral DNA using PCR. The mothers were then euthanized. Tissue samples were taken from the lungs, udder, and retromammary and prescapular lymph nodes. The kids were separated from their mothers at birth. Seven of them died. At 4 months of age, 16 kids were subjected to drug-induced immunosuppression. Blood samples were taken every month from birth to 4 months of age; samples were then taken on days 15, 21, and 28 after the start of the immunosuppressive treatment. The kids were then euthanized and tissue samples taken from the carpal synovial membrane, lung tissue, prescapular lymph nodes, inguinal and retromammary lymph nodes, and uterus. All samples from the 19 recipient goats and 23 kids were found to be negative for CAEV antibodies and/or CAEV proviral DNA. Under acute conditions for infection this study clearly demonstrates that embryo transfer can be safely used to produce CAEV-free neonates from infected CAEV donors.

Prevalence and epidemiological features of ovine enzootic abortion in Lithuania

The aim of performed study was to determine the level of enzootic abortion (EA) in sheep breeding farms in different districts of Lithuania, to determine differences in clinical signs and infection frequency between various age groups, and to evaluate the sensitivity and specificity of complement fixation test for antibodies detection and indirect immunofluorescence for antigen detection in sheep chlamydiosis. The clinical, serological and immunological tests in sheep farms were performed in 2004 and 2005. Comparing different age groups of sheep revealed that the lowest number of infected sheep was registered in animals younger than 18 months (23.1%, antibodies titre 3.191 log2, P<0.05) and highest in animals aged 18 to 24 months (53.8%, antibodies titre 4.224 log2, P<0.001). In sheep aged more than 3 years, titre of antibodies was significantly reduced. The majority of infected sheep which aborted (86.4%) was registered in 18-24 month age group. Furthermore, in sheep which aborted the infection level was 2.5-fold higher as compared to sheep which didn't abort. Analysis of smears from patological material by indirect FAT revealed that 54.5% of animals were positive to Chlamydophila abortus infection. The highest prevalence of chlamydia (66.7%) was registered in placentas of sheep which aborted.

Studies on the Safety and Immunogenicity of the South African Bluetongue Virus Serotype 2 Monovalent Vaccine: Specific Detection of the Vaccine Strain Genome by RT-PCR

In order to study the safety and the immunogenicity of the South African vaccine against the serotype 2 bluetongue virus, two groups of seven sheep were vaccinated with the vaccine used in the French island of Corsica. Vaccinated and non-vaccinated sheep were observed clinically and their rectal temperatures were recorded daily. The serological response in vaccinated animals confirmed the immunogenicity of the vaccine. Post-vaccinal viraemia was investigated and the vaccine genome was detected by reverse transcription polymerase chain reaction (RT-PCR). No viraemia was observed at post-vaccination days 4, 7 and 11 but the vaccine strain of virus was detected by RT-PCR throughout the experiment. The thermostability of the vaccine was also evaluated. The vaccine titre strongly decreased at temperatures higher than 35 degrees C.

Clinical and genetic features of Ehlers-Danlos syndrome type IV, the vascular type

BACKGROUND

Ehlers-Danlos syndrome type IV, the vascular type, results from mutations in the gene for type III procollagen (COL3A1). Affected patients are at risk for arterial, bowel, and uterine rupture, but the timing of these events, their frequency, and the course of the disease are not well documented.

METHODS

We reviewed the clinical and family histories of and medical and surgical complications in 220 index patients with biochemically confirmed Ehlers-Danlos syndrome type IV and 199 of their affected relatives. We identified the underlying COL3A1 mutation in 135 index patients.

RESULTS

Complications were rare in childhood; 25 percent of the index patients had a first complication by the age of 20 years, and more than 80 percent had had at least one complication by the age of 40. The calculated median survival of the entire cohort was 48 years. Most deaths resulted from arterial rupture. Bowel rupture, which often involved the sigmoid colon, accounted for about a quarter of complications but rarely led to death. Complications of pregnancy led to death in 12 of the 81 women who became pregnant. The types of complications were not associated with specific mutations in COL3A1.

CONCLUSIONS

Although most affected patients survive the first and second major complications, Ehlers-Danlos syndrome type IV results in premature death. The diagnosis should be considered in young people who come to medical attention because of uterine rupture during pregnancy or arterial or visceral rupture.

Priming with tat-deleted caprine arthritis encephalitis virus (CAEV) proviral DNA or live virus protects goats from challenge with pathogenic CAEV

We previously reported that infection of goats with caprine arthritis encephalitis virus (CAEV) tat- proviral DNA or virus results in persistent infection, since the animals seroconverted and direct virus isolation from cultures of blood-derived macrophages was positive. In this study we wanted to determine whether goats injected with CAEV tat- proviral DNA or virus were protected against challenge with the pathogenic homologous virus and to investigate whether CAEV tat- was still pathogenic. All animals injected with CAEV tat- became infected as indicated by seroconversion and virus isolation. Challenge at 8 or 9 months postinfection demonstrated protection in four of four animals injected with CAEV tat- but did not in three of three mock-inoculated challenged goats. Challenge virus was undetectable in the blood macrophages of protected animals during a period of 6 or 10 months postchallenge. In two of four protected animals, however, we were able to detect the challenge wild-type virus by reverse transcriptase PCR on RNA directly extracted from synovial membrane cells surrounding the inoculation site. This result suggests that protection was achieved without complete sterilizing immunity. Animals injected with CAEV tat- and mock challenged developed inflammatory lesions in the joints, although these lesions were not as severe as those in CAEV wild-type-injected goats. These results confirm the dispensable role of Tat in CAEV replication in vivo for the establishment of infection and pathogenesis and demonstrate in another lentivirus infection model the efficacy of live attenuated viruses to induce resistance to superinfection.

Strategies and outcomes of prenatal diagnosis for osteogenesis imperfecta: a review of biochemical and molecular studies completed in 129 pregnancies

We completed prenatal diagnostic studies from 129 pregnancies at risk for osteogenesis imperfecta (OI). Studies in 107 pregnancies were completed by analysis of collagen synthesized by cells cultured from chorionic villus biopsies and the remaining 22 used direct mutation identification or analysis of polymorphic restriction sites in the COL1A1 gene of type I collagen. The vast majority of studies (n = 113) were obtained to identify fetuses with OI type II (the perinatal lethal form) and some fetuses affected with OI type III or IV (the deforming varieties). Of the 50 couples who had had one previous affected pregnancy with the lethal form of OI, one had a second affected pregnancy, a rate of 2 per cent. Two of the seven unaffected couples (28 per cent) who had had two previous affected pregnancies with OI type II had a third affected pregnancy; none of the three with two previous pregnancies with OI type III had a third. Pregnancies at risk for OI type I could not be ascertained reliably by biochemical analysis of cultured CVS cells but were identified by direct analysis of the causative mutation or the use of linked markers in families. All prenatal diagnostic studies were undertaken only after earlier diagnostic studies (biochemical or molecular) had been completed on the proband, a necessary strategy for accurate results. In all pregnancies at risk for OI type II, OI type III, and OI type IV studied with biochemical strategies and in pregnancies at risk for OI type I studied with molecular techniques, there were neither false-negative nor false-positive results. Diagnostic information can be obtained within 20-30 days of biopsy using biochemical techniques and within 10-14 days when molecular strategies are used.

Requirement of caprine arthritis encephalitis virus vif gene for in vivo replication

Replication of vif-caprine arthritis encephalitis virus (CAEV) is highly attenuated in primary goat synovial membrane cells and blood-derived macrophages compared to the wild-type (wt) virus. We investigated the requirement for CAEV Vif for in vivo replication and pathogenicity in goats by intra-articular injection of either infectious proviral DNA or viral supernatants. Wild-type CAEV DNA or virus inoculation induced persistent infection resulting in severe inflammatory arthritic lesions in the joints. We were unable to detect any sign of virus replication in vif- CAEV DNA inoculated goats, while vif- CAEV virus inoculation resulted in the seroconversion of the goats. However, virus isolation and RT-PCR analyses on blood-derived macrophage cultures remained negative throughout the experiment as well as in joint or lymphoid tissues taken at necropsy. No pathologic lesions could be observed in joint tissue sections examined at necropsy. Goats inoculated with the vif- virus demonstrated no protection against a pathogenic virus challenge. These results demonstrate that CAEV Vif is absolutely required for efficient in vivo virus replication and pathogenicity and provide additional evidence that live attenuated lentiviruses have to establish a persistent infection to induce efficient protective immunity.

Studies of collagen synthesis and structure in the differentiation of child abuse from osteogenesis imperfecta

OBJECTIVE

To determine whether analysis of collagen synthesized by dermal fibroblasts could identify children with osteogenesis imperfecta (OI) among those suspected to have been abused.

METHODS

We reviewed biochemical studies and clinical findings for all children who were referred to us to distinguish OI from abuse during a 4-year period.

RESULTS

Cells from 6 of 48 children tested to distinguish OI from abuse had biochemical evidence of OI. In five of the six children with abnormal results on collagen studies, clinical signs of OI in addition to fractures were present on examination by a physician familiar with the condition. In those five cases, the diagnosis of OI was strongly suspected.

CONCLUSIONS

OI can be diagnosed by biochemical studies in some cases of suspected abuse, but clinical evaluation by experienced physicians is usually sufficient to do so. When diagnostic uncertainty persists in cases of suspected child abuse, biochemical studies may be a useful adjunct, but routine biopsy for children suspected to have been abused is unwarranted.

Biochemical and phenotypic characterization of the ovine beta 2 (leucocyte) integrins

This paper is concerned with the relationship of the three distinct members of the ovine beta 2-integrin family of leucocyte adhesion molecules that play an important role in cell-cell and cell-matrix interactions. A panel of monoclonal antibodies (mAbs) specific for sheep and cattle macrophages was characterized by flow cytometry, immunohistology, and immunoprecipitation for reactivity to the beta 2 integrins. Immunoprecipitation analysis of sheep antigens showed that these monoclonal antibodies could be divided into four distinct groups. All precipitated an M(r) 95,000 beta chain but they differed in the size or number (or both) of the alpha chains recognized. Group 1 precipitated alpha chains of M(r) 180,000; group 2 had M(r) 170,000 alpha chains; the group 3 alpha chain was of M(r) 150,000 and group 4 mAbs precipitated alpha chains of all three sizes. The relationship between these antibodies was demonstrated by sequential immunoprecipitation, which showed that the reactivities of antibodies in groups 1, 2 and 3 were mutually exclusive but that group 4 antibodies shared a common specificity with the other three groups. By analogy with the human and murine beta 2 integrin families, group 1 antibodies seemed to be specific for CD11a (LFA-1); group 2 were CD11b (CR3 or Mac1); group 3 were CD11c (CR4 or p150/95) and group 4 were CD18. In addition to different molecular weights, these antibodies had different cellular and tissue distributions. CD11a and CD18 were distributed identically. The antigens recognized by both were present on all the leucocyte populations. The mAbs recognizing CD11b reacted with a sub-population of peripheral blood B lymphocytes and all myeloid cells (alveolar macrophages, peripheral blood monocytes and granulocytes) except afferent lymph dendritic cells (ADC). Anti-CD11c (p 150/95 or CR4) antibodies reacted strongly with macrophages and ADC but were weakly reactive on monocytes and negative on neutrophils. CD11c was also present on a sub-population of peripheral blood B cells.

Lymphoscintigraphy via the targeting of macrophages with 99mTc-J001X poly-galactoside in a model of pyogranulomas developed in sheep lymph nodes

Lymphoscintigraphy usually involves labeled microparticles or colloids that distribute in the lymph flow. A new strategy for imaging pathological lymph nodes would be the targeting of macrophages recruited in these lesions. The potential for lymphoscintigraphy of the highly diffusible J001X acylated polygalactoside labeled with 99mTc was studied and compared to usual colloidal agents in a model of infectious granulomas developed in sheep. Scintigraphic and histological assessment of the specificity of targeting was performed using a MAb (OM1) raised against ovine macrophages taken as reference. This study has evidenced the ability of J001X specifically to image pathologic lymph nodes and more especially the second lymph node in the same chain with a significant scintigraphic contrast.

Expression, biological activity and kinetics of production of recombinant ovine TNF-alpha

Ovine tumour necrosis factor-alpha (OvTNF-alpha) was cloned by reverse transcription-polymerase reaction using RNA isolated from lipopolysaccharide (LPS)-stimulated alveolar macrophages and primers based on the human TNF-alpha cDNA sequence. An expression vector carrying the coding sequence of the mature form of ovine TNF was constructed. The recombinant Ov-TNF alpha (rOvTNF-alpha) was expressed as a glutathione-S-transferase (GST) fusion protein. It was cleaved with thrombin to yield rOvTNF free of the GST moiety. Growth at a lower temperature of 30 degrees C and use of Escherichia coli strains AM207, AM305, E392 and NM522 did not improve the recovery of rOvTNF-alpha from the soluble fraction to a significant extent. Purification of recombinant proteins was achieved rapidly and easily by affinity chromatography using glutathione-Sepharose. Yields of pure rOvTNF-alpha achieved in E. coli JM109 and AM207 were approximately 1 mg L-1. Both rOvTNF-alpha and recombinant human TNF-alpha (rhTNF-alpha) exerted cytotoxicity on L929 cells. However, rOvTNF-alpha but not rhTNF-alpha stimulated proliferation of ovine thymocytes. Maximum levels of TNF-alpha mRNA expression by LPS-stimulated ovine alveolar macrophages were detected at approximately 4 h post-stimulation.

Ammonium-5-tungsto-2-antimoniate (HPA23) can prevent fox rabies

HPA 23, used at 120 mg/kg, can prevent fox rabies when it is administered at the time of infection: this compound has protected two foxes. It has also delayed the time of death in thirteen other foxes.

Family studies in tuberous sclerosis. evaluation of apparently unaffected parents

A family study was conducted to evaluate the apparently unaffected parents of 13 patients with tuberous sclerosis. None of the parents had a personal or family history suggesting the diagnosis of tuberous sclerosis. All 26 parents were examined according to a protocol that entailed medical history, physical examination (including Wood's lamp examination of the skin), funduscopic examination through a dilated pupil, roentgenograms of the hands, feet, and skull, renal ultrasound studies, and cranial computed tomography (CT). In these 13 families, three fathers and one mother had previously undiagnosed tuberous sclerosis. Three of the four had skin changes, three had calcifications shown by CT, and one had renal cysts. These data demonstrate the importance of detailed examination of all parents of patients with tuberous sclerosis before recurrence-risk counseling is given.