Impact of oxygen and glucose availability on the viability and connectivity of islet cells: A computational study of reconstructed avascular human islets.

The experimental study and transplantation of pancreatic islets requires their isolation from the surrounding tissue, and therefore, from the vasculature. Under these conditions, avascular islets rely on the diffusion of peripheral oxygen and nutrients to comply with the requirements of islet cells while responding to changes in body glucose. As a complement to the experimental work, computational models have been widely used to estimate how avascular islets would be affected by the hypoxic conditions found both in culture and transplant sites. However, previous models have been based on simplified representations of pancreatic islets which has limited the reach of the simulations performed. Aiming to contribute with a more realistic model of avascular human islets, in this work we used architectures of human islets reconstructed from experimental data to simulate the availability of oxygen for α, ß and δ-cells, emulating culture and transplant conditions at different glucose concentrations. The modeling approach proposed allowed us to quantitatively estimate how the loss of cells due to severe hypoxia would impact interactions between islet cells, ultimately segregating the islet into disconnected subnetworks. According to the simulations performed, islet encapsulation, by reducing the oxygen available within the islets, could severely compromise cell viability. Moreover, our model suggests that even without encapsulation, only microislets composed of less than 100 cells would remain viable in oxygenation conditions found in transplant sites. Overall, in this article we delineate a novel modeling methodology to simulate detailed avascular islets in experimental and transplant conditions with potential applications in the field of islet encapsulation.

Prognostic value of mean velocity at the pulmonary artery estimated by cardiovascular magnetic resonance as a prognostic predictor in a cohort of patients with new-onset heart failure with reduced ejection fraction.

BACKGROUND: Pulmonary hypertension (PH) conveys a worse prognosis in heart failure (HF), in particular when right ventricular (RV) dysfunction ensues. Cardiovascular magnetic resonance (CMR) non-invasively estimates pulmonary vascular resistance (PVR), which has shown prognostic value in HF. Importantly, RV to pulmonary artery (PA) coupling is altered early in HF, before significant rise in PV resistance occurs. The aim of this study was to assess the prognostic value of mean velocity at the pulmonary artery (mvPA), a novel non-invasive parameter determined by CMR, in HF with reduced ejection fraction (HFrEF) with and without associated PH. METHODS: Prospective inclusion of 238 patients admitted for new-onset HFrEF. MvPA was measured with CMR during index admission. The primary endpoint was defined as a composite of HF readmissions and all-cause mortality. RESULTS: During a median follow-up of 25 months, 91 patients presented with the primary endpoint. Optimal cut-off value of mvPA calculated by the receiver operator curve for the prediction of the primary endpoint was 9 cm/s. The primary endpoint occurred more frequently in patients with mvPA≤9 cm/s, as indicated by Kaplan-Meier survival curves; Log Rank 16.0, p <  0.001. Importantly, mvPA maintained its prognostic value regardless of RV function and also when considering mortality and HF readmissions separately. On Cox proportional hazard analysis, reduced mvPA≤9 cm/s emerged as an independent prognostic marker, together with NYHA III-IV/IV class, stage 3-4 renal failure and ischemic cardiomyopathy. CONCLUSIONS: In our HFrEF cohort, mvPA emerged as an independent prognostic indicator independent of RV function, allowing identification of a higher-risk population before structural damage onset. Moreover, mvPA emerged as a surrogate marker of the RV-PA unit coupling status.

Root colonization and arbuscular mycorrhizal fungal community composition in a genetically modified maize, its non-modified isoline, and a landrace.

The use of genetically modified (GM) plants has increased in recent decades, but there are uncertainties about their effects on soil microbial communities. Aiming to quantify root colonization and characterize arbuscular mycorrhizal fungi (AMF) communities associated with roots and rhizosphere soil of different maize genotypes, a field trial was carried out in Southern Brazil with three maize genotypes as follows: a GM hybrid (DKB 240 VTPRO), its non-modified isoline (DKB 240), and a landrace (Pixurum). Soil samples were collected to evaluate the occurrence of AMF during the growth of corn genotypes at sowing and V3 (vegetative), R1 (flowering), and R3 (grain formation) stages of the crop. The occurrence of AMF was determined by the morphological identification of spores, and by analyzing AMF community composition in soil and roots of maize, using PCR-DGGE. The GM genotype of maize promoted lower mycorrhizal colonization in the vegetative stage and had lower sporulation at grain development than the conventional hybrid and the landrace maize. Twenty AMF morphotypes were identified and 13 were associated with all maize genotypes. The genera Acaulospora, Glomus, and Dentiscutata had the largest numbers of species. There were no differences in AMF community composition due to maize genotypes or genetic modification, but crop phenological stages affected AMF communities associated with maize roots.

Landrace maize varieties differ from conventional and genetically modified hybrid maize in response to inoculation with arbuscular mycorrhizal fungi.

Land area planted with genetically modified (GM) crops has grown rapidly, and Brazil has the second largest area with those plants. There is, however, limited information on the possible effects of that technology on non-target organisms, especially root symbionts, such as arbuscular mycorrhizal fungi (AMF). We evaluated AMF symbiosis development in five maize genotypes: one landrace, two conventional hybrids (DKB 240 and Formula), and two GM hybrids (DKB 240-VT Pro and Formula TL). We evaluated symbiosis response in two separate experiments: one in autumn and the other in summer. Plants were inoculated with Rhizophagus clarus (Rc) and Gigaspora margarita (Gm) and compared to plants without inoculation. We evaluated root colonization, spore number, and plant biomass and phosphorous accumulation 30 and 60 days after inoculation. There were no consistent effects of GM crops, but AMF species and maize genotype affected symbiosis development. Formula genotype (isoline and GM) had a negative response to inoculation, with a decrease of around 30% in biomass and P concentration in Rc-inoculated plants. The maize landrace had a positive response, with increases of 17% and 14% in the same variables. DKB genotype (isoline and GM) showed negative, positive, and neutral effects. The results show that plant genetic identity is a determinant factor in symbiosis performance, suggesting that plants selected in low P availability can make better use of mycorrhizal symbiosis. Given the role that AMF play in different ecosystem processes, use of landrace maize may contribute to agrobiodiversity conservation.

Selection and characterization of coal mine autochthonous rhizobia for the inoculation of herbaceous legumes.

Coal open pit mining in the South of Santa Catarina state (Brazil) was inappropriately developed, affecting approximately 6.700 ha. Re-vegetation is an alternative for the recovery of these areas. Furthermore, the use of herbaceous legumes inoculated with nitrogen fixing bacteria is motivated due to the difficulty implementing a vegetation cover in these areas, mainly due to low nutrient availability. Therefore, the aim of this work was to evaluate, among 16 autochthonous rhizobia isolated from the coal mining areas, those with the greatest potential to increase growth of the herbaceous legumes Vicia sativa and Calopogonium mucunoides. Tests were conducted in greenhouse containing 17 inoculation treatments (16 autochthonous rhizobia + Brazilian recommended strain for each plant species), plus two treatments without inoculation (with and without mineral nitrogen). After 60 days, nodulation, growth, N uptake, and symbiotic efficiency were evaluated. Isolates characterization was assessed by the production of indole acetic acid, ACC deaminase, siderophores, and inorganic phosphate solubilization. The classification of the isolates was performed by 16 S rDNA gene sequencing. Only isolates UFSC-M4 and UFSC-M8 were able to nodulate C. mucunoides. Among rhizobia capable of nodulating V. sativa, only UFSC-M8 was considered efficient. It was found the presence of more than one growth-promoting attributes in the same organism, and isolate UFSC-M8 presented all of them. Isolates were classified as belonging to Rhizobium, Burkholderia and Curtobacterium. The results suggest the inoculation of Vicia sativa with strain UFSC-M8, classified as Rhizobium sp., as a promising alternative for the revegetation of coal mining degraded areas.

Reproductive Strategy of the Polyploid Species Varronia curassavica Jacq. in Restinga Environment.

This study aimed to elucidate the breeding strategies of Varronia curassavica, an important medicinal species associated with Brazilian restinga. This was accomplished by combining phenological and genetic data. Every 2 weeks over a period of 2 years, we measured flowering and fruiting phenology to evaluate the activity and intensity of phenophases (n = 60). We evaluated the mating system, pollen ovule ratio and genotypes from progeny and mother plants using 8 nuclear microsatellite loci. We observed flowering and fruiting of V. curassavica at low intensity throughout the entire year, but with 2 distinct peaks, one of which was seasonal, corresponding to the period of gradual increase of temperature and photoperiod. Overlapping of flowering and fruiting strategies favors gene flow among different groups of individuals and between populations by attraction of fauna throughout the year. Analysis of the mating system indicates that V. curassavica is a typical outcrossed species (t^ = 0.98; pollen/ovule ratio = 7087.50). Combining phenology with genetic studies improved our understanding of the reproductive strategies of this species. The typical outcrossing system of V. curassavica reflects the existence of functional self-incompatibility mechanisms still unaffected by changes in genetic balance by polyploidy.

Cost-Effectiveness Analysis of the Use of a Prophylactic Antibiotic for Patients Undergoing Lower Limb Amputation due to Diabetes or Vascular Illness in Colombia.

BACKGROUND: The use of a prophylactic antibiotic in an amputation surgery is a key element for the successful recovery of the patient. We aim to determine, from the perspective of the Colombian health system, the cost-effectiveness of administering a prophylactic antibiotic among patients undergoing lower limb amputation due to diabetes or vascular illness in Colombia. METHODS: A decision tree was constructed to compare the use and nonuse of a prophylactic antibiotic. The probabilities of transition were obtained from studies identified from a systematic review of the clinical literature. The chosen health outcome was reduction in mortality due to prevention of infection. The costs were measured by expert consensus using the standard case methodology, and the resource valuation was carried out using national-level pricing manuals. Deterministic sensitivity, scenarios, and probabilistic analyses were conducted. RESULTS: In the base case, the use of a prophylactic antibiotic compared with nonuse was a dominant strategy. This result was consistent when considering different types of medications and when modifying most of the variables in the model. The use of a prophylactic antibiotic ceases to be dominant when the probability of infection is greater than 48%. CONCLUSIONS: The administration of a prophylactic antibiotic was a dominant strategy, which is a conclusion that holds in most cases examined; therefore, it is unlikely that the uncertainty around the estimation of costs and benefits change the results. We recommend creating policies oriented toward promoting the use of a prophylactic antibiotic during amputation surgery in Colombia.

Arbuscular mycorrhizal fungi in the growth and extraction of trace elements by Chrysopogon zizanioides (vetiver) in a substrate containing coal mine wastes.

Vetiver (Chrysopogon zizanioides) is a fast-growing, high biomass producing plant employed for environmental rehabilitation. The study evaluated the effects of arbuscular mycorrhizal fungi (AMF) on the growth and trace element phytoextracting capabilities of vetiver in a substrate containing coalmine wastes in Southern Brazil. AMF included Acaulospora colombiana, Acaulospora morrowiae, Acaulospora scrobiculata, Dentiscutata heterogama, Gigaspora margarita, and Rhizophagus clarus. Among those, A. colombiana, G. margarita, and R. clarus promoted higher growth. AMF stimulated average increments in the accumulated P of 82% (roots), 194% (shoots first harvest-90 days) and 300% (shoots second harvest-165 days) and affected the phytoextraction of trace elements by vetiver, with larger concentrations in the roots. Plants inoculated with A. colombiana, A. morrowiae, and A. scrobiculata, in addition to the control, presented the highest levels of Cu and Zn in the roots. Overall, G. margarita stimulated the highest production of biomass, and, therefore, showed the most significant levels of trace elements in the plants. This work shows the benefits of certain AMF (especially A. morrowiae, G. margarita, and R. clarus) for the production of biomass and P uptake by vetiver, demonstrating the potential of those species for the rehabilitation of coal-mine-degraded soils.

A novel human autoantigen, endothelial cell growth factor, is a target of T and B cell responses in patients with Lyme disease.

OBJECTIVE: Autoantigen presentation by HLA-DR molecules is thought to be a central component of many autoimmune diseases, but identifying disease-relevant autoantigens has been a difficult challenge. In this study we aimed to identify autoantigens in patients with antibiotic-refractory Lyme arthritis, in which infection-induced autoimmunity is thought to play an important role. METHODS: Using tandem mass spectrometry, naturally presented HLA-DR self peptides from a patient's synovium were identified, synthesized, and reacted with his peripheral blood mononuclear cells (PBMCs). Immunoreactive peptides and their source proteins were then tested for T and B cell responses using large numbers of patient cells or sera. RESULTS: Of 120 HLA-DR-presented self peptides identified from one patient, one peptide derived from endothelial cell growth factor (ECGF) caused his PBMCs to proliferate. T and B cell responses to ECGF occurred systemically in ∼10-30% of patients with early or late manifestations of Lyme disease, primarily in those with refractory arthritis-associated HLA-DR alleles, such as DRB1*0101 and 0401. Compared with patients with antibiotic-responsive arthritis, those with antibiotic-refractory arthritis had significantly higher concentrations of ECGF in synovial fluid (P<0.0001) and more often had ECGF antibody reactivity. Among non-antibiotic-treated historical patients who developed arthritis, 26% had ECGF reactivity, which often developed before the onset of arthritis and was associated with significantly longer courses of arthritis. CONCLUSION: T and B cell responses to ECGF occur in a subset of patients with Lyme disease, particularly in those with antibiotic-refractory arthritis, providing the first direct evidence of autoimmune T and B cell responses in this illness.

Improved Recovery of Complete Spinal Cord Transection by a Plasma-Modified Fibrillar Scaffold.

Complete spinal cord injury causes an irreversible disruption in the central nervous system, leading to motor, sensory, and autonomic function loss, and a secondary injury that constitutes a physical barrier preventing tissue repair. Tissue engineering scaffolds are presented as a permissive platform for cell migration and the reconnection of spared tissue. Iodine-doped plasma pyrrole polymer (pPPy-I), a neuroprotective material, was applied to polylactic acid (PLA) fibers and implanted in a rat complete spinal cord transection injury model to evaluate whether the resulting composite implants provided structural and functional recovery, using magnetic resonance (MR) imaging, diffusion tensor imaging and tractography, magnetic resonance spectroscopy, locomotion analysis, histology, and immunofluorescence. In vivo, MR studies evidenced a tissue response to the implant, demonstrating that the fibrillar composite scaffold moderated the structural effects of secondary damage by providing mechanical stability to the lesion core, tissue reconstruction, and significant motor recovery. Histologic analyses demonstrated that the composite scaffold provided a permissive environment for cell attachment and neural tissue guidance over the fibers, reducing cyst formation. These results supply evidence that pPPy-I enhanced the properties of PLA fibrillar scaffolds as a promising treatment for spinal cord injury recovery.

IL-10 Prevents apoptosis of brain endothelium during bacteremia.

IL-10-deficient mice infected with the relapsing fever bacterium Borrelia turicatae rapidly succumb to a brain hemorrhage if they are unable to clear peak bacteremia. In this study, we investigated the protective role of IL-10 during relapsing-remitting bacteremia and explored the molecular events involved in the protection of brain endothelium by IL-10. Brain endothelial injury was measured with cytotoxicity and diverse apoptotic assays, whereas the signaling pathway analysis was done by quantitative PCR array. The results showed that severe endothelial cell injury leading to hemorrhage in the brain and other organs occurred in IL-10-deficient mice during relapsing-remitting infection. Human brain microvascular endothelial cells (HBMEC) produced abundant proinflammatory mediators upon exposure to whole bacteria or purified bacterial lipoprotein but did not produce any detectable IL-10. Whole bacteria and purified outer membrane lipoprotein rapidly killed HBMEC by apoptosis in a time- and concentration-dependent manner. Exogenous IL-10 protected HBMEC from apoptosis. HBMEC apoptosis during exposure to a low number of bacteria was associated with downregulation of TNF and TNFAIP3 and upregulation of BAX. In contrast, HBMEC apoptosis during exposure to high concentrations of purified outer membrane lipoprotein was associated with marked upregulation of FAS, FAS ligand, and the adaptor molecules RIPK1 and CFLAR. Exogenous IL-10 reversed all the apoptotic signaling changes induced by whole bacteria or its purified lipoprotein. The results indicate that prominent brain endothelial cell apoptosis occurs during relapsing-remitting bacteremia in the absence of IL-10 and point to a prominent role for bacterial lipoprotein-mediated activation of FAS and caspase-3 in this process.

Ecological urbanism as a condition underpinning urban life for internally displaced peoples in Colombia.

This paper employs the concepts of sustainability and habitability to define and measure ecological urbanism in informal settlements founded by people who have been forcibly displaced by violence. The objective is to identify the obstacles in meeting the tenets of ecological urbanism in informal settlements. We offer primary research from La Primavera, an informal settlement founded by internally displaced people in the late 1970s, located in the corregimiento El Hatillo of Barbosa, Antioquia in northwestern Colombia. Primary research includes qualitative and quantitative data gathered through 72 surveys and 45 technical assessments of properties and houses in the settlement. Situated between the Aburrá River and the northbound highway, above a gas pipeline and under an electricity pylon, La Primavera exists in a state of extreme risk, exacerbated by increasing migration which threatens to exceed the carrying capacity of the territory. Moreover, in Article 35 of Law 388 of 1997, the territory was declared a protected or restricted area and earmarked for the development of the regional commuter train, called the Tren de Cercanías, in 2017. The case study highlights the contradictions in the development agenda in Colombia by showing how development projects designed for the economic betterment and environmental conservation of the region negatively impact the quality of life for the most vulnerable inhabitants and expose them to greater environmental, economic, and social risk.

ADC restriction is not associated with clinical response to plasma exchange following a cerebral attack of multiple sclerosis.

BACKGROUND: MS is the most common CNS inflammatory demyelinating disease. Plasma exchange (PLEX) has well-demonstrated efficacy in acute corticosteroid-refractory attacks of demyelination but identifying the factors that predict favorable PLEX response remains elusive. We aimed to determine if apparent diffusion coefficient (ADC) restriction on brain MRI predicts clinical response to PLEX in individuals with an acute cerebral attack of MS. METHODS: Retrospective chart review of individuals with a cerebral attack of MS who underwent PLEX at Mayo Clinic. RESULTS: We identified 34 individuals who fulfilled the inclusion criteria. Twenty-seven (79%) responded to plasma exchange, with 16/34 (47%) having moderate and 11/34 (32%) marked improvement. Twenty-three (68%) people had ADC restriction on brain MRI prior to PLEX.  ADC restriction did not predict response (p = 0.51). Several other pre-PLEX factors, including sex, Expanded Disability Status Scale (EDSS) at initial attack, time to PLEX, and concurrent spinal cord attack, also failed to predict response. Plasma-exchange responders had less disability at 6-month follow-up compared to non-responders (median EDSS 2.5 (range 1.0-10.0) vs. 7.5 (5.5-10.0), p<0.001). CONCLUSION: Acute cerebral attacks of MS have a high rate of plasma exchange response resulting in a lower EDSS at 6-months. ADC restriction does not predict response to plasma exchange.

Some Contributions From The Scientific Realism of Evandro Agazzi to Discursive Social Psychology.

This article aims to show how the scientific realism proposed by the philosopher Evandro Agazzi contributes to the epistemological development of social discursive psychology. To do this, the debates led by Ian Parker and John Greenwood in the early 1990s about scientific and critical realism are addressed. In this debate, the limits of naive empiricism and discursive idealism, which began to predominate in discursive social psychology, are highlighted. Evandro Agazzi's assumptions about scientific realism are then presented to account for the contributions of scientific realism to the epistemological development of discursive social psychology.

Population-based study of erectile dysfunction and polypharmacy.

UNLABELLED: Study Type - Symptom prevalence (population cohort). Level of Evidence 1b. What's known on the subject? and What does the study add? It is known that medical conditions such as diabetes, high blood pressure, high cholesterol, smoking and prescribed medications cause erectile dysfunction (ED). This has been studied at the molecular level and reported in population studies. The present study shows that, after accounting for known medical problems, there is a dose-response relationship, in which worsening degrees of ED are seen when a greater number of medications are taken, regardless if they are prescribed or over the counter. The study can help primary care doctors and urologists to make a differential diagnosis of ED and it can also help improve patient's erectile function by tailoring and curtailing current medication use to maximize therapeutic benefit but minimize ED side effects in men, thus improving health-related quality of life. OBJECTIVE: • To study the association between erectile dysfunction (ED) and polypharmacy use in a large, ethnically and racially diverse cohort of men enrolled in the California Men's Health Study (CMHS). PATIENTS AND METHODS: • Men from the Kaiser Permanente Southern California (KPSC) health plan, enrolled in the CMHS in 2002, had an age range of 45-69 years. ED and comorbidities of these subjects were identified by questionnaire responses. • The number of drugs taken was determined from the year before enrollment through electronic pharmacy records and questionnaire responses. RESULTS: • Among the 37 712 (KPSC) subjects, 10 717 (29%) reported moderate or severe ED. • Across all age groups, ED was more prevalent as the number of medications increased. • In men taking 0-2, 3-5,6-9 and ≥ 10 medications, the percentage of men reporting moderate ED was 15.9, 19.7, 25.5 and 30.9%, respectively (P < 0.001). • With adjustment for age, race, smoking, diabetes, hypertension, hyperlipidaemia, peripheral vascular disease, coronary artery disease and body mass index, men taking >10 drugs were more likely to have ED (odds ratio = 2.32, 95% confidence interval 2.14-2.52) with evidence of a dose-response relationship. CONCLUSION: • These data suggest that the number of medications a man takes is associated with worse ED, even after comorbidities have been taken into account.

Diagnosis of coexistent neurodegenerative dementias in multiple sclerosis.

Among people with multiple sclerosis, cognitive impairment occurs commonly and is a potent predictor of disability. Some multiple sclerosis patients present with severe cognitive impairment, and distinguishing multiple sclerosis-related cognitive impairment from co-existent progressive neurodegenerative diseases such as Alzheimer disease poses a diagnostic challenge. The use of biomarkers such as PET and CSF proteins may facilitate this distinction. The study was a retrospective, descriptive study on convenience samples of separate cohorts, one of cognitively impaired multiple sclerosis patients evaluated on autopsy to demonstrate coincidence of both multiple sclerosis and neurodegenerative cognitive diseases. The second cohort were cognitively impaired multiple sclerosis patients evaluated by biomarker to investigate possible additional neurodegenerative cognitive disorders contributing to the cognitive impairment. We investigated selected biomarkers among 31 severely impaired patients (biomarker cohort) and 12 severely impaired patients assessed at autopsy and selected 24 (23 biomarker cohort, 1 autopsy cohort) had comprehensive neurocognitive testing. Biomarker cohort investigations included 18F-Fluorodeoxyglucose PET and/or CSF amyloid Aß1-42, phospho-tau and total tau levels. The autopsy cohort was evaluated with comprehensive neuropathological assessment for aetiology of cognitive impairment. The cohorts shared similar sex, age at multiple sclerosis onset and multiple sclerosis clinical course. The autopsy-cohort patients were older at diagnosis (69.5 versus 57 years, P = 0.006), had longer disease duration [median (range) 20 years (3-59) versus 9 (1-32), P = 0.001] and had more impaired bedside mental status scores at last follow-up [Kokmen median (range) 23 (1-38) versus 31 (9-34) P = 0.01]. Autopsy-cohort patients confirmed, or excluded, coexistent neurogenerative disease by neuropathology gold standard. Most biomarker-cohort patients had informative results evaluating coexistent neurogenerative disease. Biomarkers may be useful in indicating a coexistent neurodegenerative disease earlier, and in life, in patients with multiple sclerosis and significant cognitive impairment.

Bacterial lipoproteins can disseminate from the periphery to inflame the brain.

The current view is that bacteria need to enter the brain to cause inflammation. However, in mice infected with the spirochete Borrelia turicatae, we observed widespread cerebral inflammation despite a paucity of spirochetes in the brain parenchyma at times of high bacteremia. Here we studied the possibility that bacterial lipoproteins may be capable of disseminating from the periphery across the blood-brain barrier to inflame the brain. For this we injected normal and infected mice intraperitoneally with lanthanide-labeled variable outer membrane lipoproteins of B. turicatae and measured their localization in blood, various peripheral organs, and whole and capillary-depleted brain protein extracts at various times. Lanthanide-labeled nonlipidated lipoproteins of B. turicatae and mouse albumin were used as controls. Brain inflammation was measured by TaqMan RT-PCR amplification of genes known to be up-regulated in response to borrelial infection. The results showed that the two lipoproteins we studied, LVsp1 and LVsp2, were capable of inflaming the brain after intraperitoneal injection to different degrees: LVsp1 was better than LVsp2 and Bt1 spirochetes at moving from blood to brain. The dissemination of LVsp1 from the periphery to the brain occurred under normal conditions and significantly increased with infection. In contrast, LVsp2 disseminated better to peripheral organs. We conclude that some bacterial lipoproteins can disseminate from the periphery to inflame the brain.

Pyrrole Plasma Polymer-Coated Electrospun Scaffolds for Neural Tissue Engineering.

Promising strategies for neural tissue engineering are based on the use of three-dimensional substrates for cell anchorage and tissue development. In this work, fibrillar scaffolds composed of electrospun randomly- and aligned-oriented fibers coated with plasma synthesized pyrrole polymer, doped and undoped with iodine, were fabricated and characterized. Infrared spectroscopy, thermogravimetric analysis, and X-ray diffraction analysis revealed the functional groups and molecular integration of each scaffold, as well as the effect of plasma polymer synthesis on crystallinity. Scanning microscopy imaging demonstrated the porous fibrillar micrometric structure of the scaffolds, which afforded adhesion, infiltration, and survival for the neural cells. Orientation analysis of electron microscope images confirmed the elongation of neurite-like cell structures elicited by undoped plasma pyrrole polymer-coated aligned scaffolds, without any biochemical stimuli. The MTT colorimetric assay validated the biocompatibility of the fabricated composite materials, and further evidenced plasma pyrrole polymer-coated aligned scaffolds as permissive substrates for the support of neural cells. These results suggest plasma synthesized pyrrole polymer-coated aligned scaffolds are promising materials for tissue engineering applications.

Pyrrole Plasma Polymer-Coated Fibrillar Scaffold Implant: Pilot Study in Rat Spinal Cord Transection with MRI.

Despite extensive research on spinal cord injury (SCI) therapies for the recovery of motor, sensory and autonomic function, currently there are no effective treatments to completely restore tissue structure and function. In this work, a polylactic acid (PLA) fibrillar scaffold coated with pyrrole plasma polymer doped with iodine (pPPy/I), was studied as therapeutic strategy in a SCI transection model. Magnetic resonance imaging (MRI) was used to evaluate tissue response to the implant. Behavioral analysis using the BBB open-field testing was conducted to evaluate functional response. MRI analysis showed the SCI model completely disrupted tissue continuity, and diffusion indices were altered at the injury site. The animals had completely paralyzed hindlimbs and bladder control loss after injury. After 8 weeks of treatment, in contrast to control and PLA-implanted animals, PLA+pPPy/I-implanted animal had regained bladder control autonomy and frequent to consistent weight supported plantar steps and occasional coordination between forelimbs and hindlimbs. These results suggest fibrillar scaffolds coated with pPPy/I constitute a promising therapy for SCI.

IL-10 helps control pathogen load during high-level bacteremia.

During relapsing fever borreliosis, a high pathogen load in the blood occurs at times of peak bacteremia. Specific IgM Abs are responsible for spirochetal clearance so in absence of B cells there is persistent high-level bacteremia. Previously, we showed that B cell-deficient mice persistently infected with Borrelia turicatae produce high levels of IL-10 and that exogenous IL-10 reduces bacteremia. This suggested that IL-10 helps reduce bacteremia at times of high pathogen load by a B cell-independent mechanism, most likely involving innate immunity. To investigate this possibility, we compared B. turicatae infection in RAG2/IL-10(-/-) and RAG2(-/-) mice. The results showed that IL-10 deficiency resulted in significantly higher bacteremia, higher TNF levels, and early mortality. Examination of the spleen and peripheral blood showed markedly increased apoptosis of immune cells in infected RAG2/IL-10(-/-) mice. Neutralization of TNF reduced apoptosis of leukocytes and splenocytes, increased production of IFN-gamma by NK cells, increased phagocytosis in the spleen, decreased spirochetemia, and rescued mice from early death. Our results indicate that at times of high pathogen load, as during peak bacteremia in relapsing fever borreliosis, IL-10 protects innate immune cells from apoptosis via inhibition of TNF resulting in improved pathogen control.