Efficacy of a novel three-step decontamination protocol for titanium-based dental implants: An in vitro and in vivo study.

AIM: The aim of the study was to evaluate several mechanical and chemical decontamination methods associated with a newly introduced biofilm matrix disruption strategy for biofilm cleaning and preservation of implant surface features. MATERIALS AND METHODS: Titanium (Ti) discs were obtained by additive manufacturing. Polymicrobial biofilm-covered Ti disc surfaces were decontaminated with mechanical [Ti curette, Teflon curette, Ti brush, water-air jet device, and Er:YAG laser] or chemical [iodopovidone (PVPI) 0.2% to disrupt the extracellular matrix, along with amoxicillin; minocycline; tetracycline; H2 O2 3%; chlorhexidine 0.2%; NaOCl 0.95%; hydrocarbon-oxo-borate-based antiseptic] protocols. The optimal in vitro mechanical/chemical protocol was then tested in combination using an in vivo biofilm model with intra-oral devices. RESULTS: Er:YAG laser treatment displayed optimum surface cleaning by biofilm removal with minimal deleterious damage to the surface, smaller Ti release, good corrosion stability, and improved fibroblast readhesion. NaOCl 0.95% was the most promising agent to reduce in vitro and in vivo biofilms and was even more effective when associated with PVPI 0.2% as a pre-treatment to disrupt the biofilm matrix. The combination of Er:YAG laser followed by PVPI 0.2% plus NaOCl 0.95% promoted efficient decontamination of rough Ti surfaces by disrupting the biofilm matrix and killing remnants of in vivo biofilms formed in the mouth (the only protocol to lead to ~99% biofilm eradication). CONCLUSION: Er:YAG laser + PVPI 0.2% + NaOCl 0.95% can be a reliable decontamination protocol for Ti surfaces, eliminating microbial biofilms without damaging the implant surface.

A Molecular Analysis of Memory B Cell and Antibody Responses Against Plasmodium falciparum Merozoite Surface Protein 1 in Children and Adults From Uganda.

Memory B cells (MBCs) and plasma antibodies against Plasmodium falciparum (Pf) merozoite antigens are important components of the protective immune response against malaria. To gain understanding of how responses against Pf develop in these two arms of the humoral immune system, we evaluated MBC and antibody responses against the most abundant merozoite antigen, full-length Pf merozoite surface protein 1 (PfMSP1FL), in individuals from a region in Uganda with high Pf transmission. Our results showed that PfMSP1FL-specific B cells in adults with immunological protection against malaria were predominantly IgG+ classical MBCs, while children with incomplete protection mainly harbored IgM+ PfMSP1FL-specific classical MBCs. In contrast, anti-PfMSP1FL plasma IgM reactivity was minimal in both children and adults. Instead, both groups showed high plasma IgG reactivity against PfMSP1FL, with broadening of the response against non-3D7 strains in adults. The B cell receptors encoded by PfMSP1FL-specific IgG+ MBCs carried high levels of amino acid substitutions and recognized relatively conserved epitopes on the highly variable PfMSP1 protein. Proteomics analysis of PfMSP119-specific IgG in plasma of an adult revealed a limited repertoire of anti-MSP1 antibodies, most of which were IgG1 or IgG3. Similar to B cell receptors of PfMSP1FL-specific MBCs, anti-PfMSP119 IgGs had high levels of amino acid substitutions and their sequences were predominantly found in classical MBCs, not atypical MBCs. Collectively, these results showed evolution of the PfMSP1-specific humoral immune response with cumulative Pf exposure, with a shift from IgM+ to IgG+ B cell memory, diversification of B cells from germline, and stronger recognition of PfMSP1 variants by the plasma IgG repertoire.

SARS-CoV-2 spike-specific memory B cells express higher levels of T-bet and FcRL5 after non-severe COVID-19 as compared to severe disease.

SARS-CoV-2 infection elicits a robust B cell response, resulting in the generation of long-lived plasma cells and memory B cells. Here, we aimed to determine the effect of COVID-19 severity on the memory B cell response and characterize changes in the memory B cell compartment between recovery and five months post-symptom onset. Using high-parameter spectral flow cytometry, we analyzed the phenotype of memory B cells with reactivity against the SARS-CoV-2 spike protein or the spike receptor binding domain (RBD) in recovered individuals who had been hospitalized with non-severe (n = 8) or severe (n = 5) COVID-19. One month after symptom onset, a substantial proportion of spike-specific IgG+ B cells showed an activated phenotype. In individuals who experienced non-severe disease, spike-specific IgG+ B cells showed increased expression of markers associated with durable B cell memory, including T-bet and FcRL5, as compared to individuals who experienced severe disease. While the frequency of T-bet+ spike-specific IgG+ B cells differed between the two groups, these cells predominantly showed an activated switched memory B cell phenotype in both groups. Five months post-symptom onset, the majority of spike-specific memory B cells had a resting phenotype and the percentage of spike-specific T-bet+ IgG+ memory B cells decreased to baseline levels. Collectively, our results highlight subtle differences in the B cells response after non-severe and severe COVID-19 and suggest that the memory B cell response elicited during non-severe COVID-19 may be of higher quality than the response after severe disease.

Longitudinal analysis of FcRL5 expression and clonal relationships among classical and atypical memory B cells following malaria.

BACKGROUND: Chronic and frequently recurring infectious diseases, such as malaria, are associated with expanded populations of atypical memory B cells (MBCs). These cells are different from classical MBCs by the lack of surface markers CD21 and CD27 and increased expression of inhibitory receptors, such as FcRL5. While the phenotype and conditions leading to neogenesis of atypical MBCs in malaria-experienced individuals have been studied extensively, the origin of these cells remains equivocal. Functional similarities between FcRL5+ atypical MBCs and FcRL5+ classical MBCs have been reported, suggesting that these cells may be developmentally related. METHODS: Here, a longitudinal analysis of FcRL5 expression in various B cell subsets was performed in two children from a high transmission region in Uganda over a 6-month period in which both children experienced a malaria episode. Using B-cell receptor (BCR)-sequencing to track clonally related cells, the connections between IgM+ and IgG+ atypical MBCs and other B cell subsets were studied. RESULTS: The highest expression of FcRL5 was found among IgG+ atypical MBCs, but FcRL5+ cells were present in all MBC subsets. Following malaria, FcRL5 expression increased in all IgM+ MBC subsets analysed here: classical, activated, and atypical MBCs, while results for IgG+ MBC subsets were inconclusive. IgM+ atypical MBCs showed few connections with other B cell subsets, higher turnover than IgG+ atypical MBCs, and were predominantly derived from naïve B cells and FcRL5- IgM+ classical MBCs. In contrast, IgG+ atypical MBCs were clonally expanded and connected with classical MBCs. IgG+ atypical MBCs present after a malaria episode mainly originated from FcRL5+ IgG+ classical MBCs. CONCLUSIONS: Collectively, these results suggest fundamental differences between unswitched and class-switched B cell populations and provide clues about the primary developmental pathways of atypical MBCs in malaria-experienced individuals.

SARS-CoV-2 spike-specific memory B cells express markers of durable immunity after non-severe COVID-19 but not after severe disease.

SARS-CoV-2 infection elicits a robust B cell response, resulting in the generation of long-lived plasma cells and memory B cells. Here, we aimed to determine the effect of COVID-19 severity on the memory B cell response and characterize changes in the memory B cell compartment between recovery and five months post-symptom onset. Using high-parameter spectral flow cytometry, we analyzed the phenotype of memory B cells with reactivity against the SARS-CoV-2 spike protein or the spike receptor binding domain (RBD) in recovered individuals who had been hospitalized with non-severe (n=8) or severe (n=5) COVID-19. One month after symptom onset, a substantial proportion of spike-specific IgG + B cells showed an activated phenotype. In individuals who experienced non-severe disease, spike-specific IgG + B cells showed increased expression of markers associated with durable B cell memory, including T-bet, FcRL5, and CD11c, which was not observed after severe disease. Five months post-symptom onset, the majority of spike-specific memory B cells had a resting phenotype and the percentage of spike-specific T-bet + IgG + memory B cells decreased to baseline levels. Collectively, our results suggest that the memory B cell response elicited during non-severe COVID-19 may be of higher quality than the response after severe disease.

B Cell Receptor Repertoire Analysis in Malaria-Naive and Malaria-Experienced Individuals Reveals Unique Characteristics of Atypical Memory B Cells.

Malaria, caused by parasites of the Plasmodium genus, is responsible for significant morbidity and mortality globally. Chronic Plasmodium falciparum exposure affects the B cell compartment, leading to the accumulation of atypical memory B cells (atMBCs). IgM-positive (IgM+) and IgG+ atMBCs have not been compared in-depth in the context of malaria, nor is it known if atMBCs in malaria-experienced individuals are different from phenotypically similar B cells in individuals with no known history of Plasmodium exposure. To address these questions, we characterized the B cell receptor (BCR) repertoire of naive B cells (NBCs), IgM+ and IgG+ classical MBCs (cMBCs), and IgM+ and IgG+ atMBCs from 13 malaria-naive American adults and 7 malaria-experienced Ugandan adults. Our results demonstrate that P. falciparum exposure mainly drives changes in atMBCs. In comparison to malaria-naive adults, the BCR repertoire of Plasmodium-exposed adults showed increased levels of somatic hypermutation in the heavy chain V region in IgM+ and IgG+ atMBCs, shorter heavy chain complementarity-determining region 3 (HCDR3) in IgG+ atMBCs, and increased usage of IGHV3-73 in IgG+ cMBCs and both IgM+ and IgG+ atMBCs. Irrespective of Plasmodium exposure, IgM+ atMBCs closely resembled NBCs, while IgG+ atMBCs resembled IgG+ cMBCs. Physicochemical properties of the HCDR3 seemed to be intrinsic to cell type and independent of malaria experience. The resemblance between atMBCs from Plasmodium-exposed and naive adults suggests similar differentiation pathways regardless of chronic antigen exposure. Moreover, these data demonstrate that IgM+ and IgG+ atMBCs are distinct populations that should be considered separately in future analyses. IMPORTANCE Malaria, caused by Plasmodium parasites, still contributes to a high global burden of disease, mainly in children under 5 years of age. Chronic and recurrent Plasmodium infections affect the development of B cell memory against the parasite and promote the accumulation of atypical memory B cells (atMBCs), which have an unclear function in the immune response. Understanding where these cells originate from and whether they are beneficial in the immune response to Plasmodium will help inform vaccination development efforts. We found differences in B cell receptor (BCR) properties of atMBCs between malaria-naive and malaria-experienced adults that are suggestive of divergent selection processes, resulting in more somatic hypermutation and differential immunoglobulin heavy chain V (IGHV) gene usage. Despite these differences, atMBCs from malaria-naive and malaria-experienced adults also showed many similarities in BCR characteristics, such as physicochemical properties of the HCDR3 region, suggesting that atMBCs undergo similar differentiation pathways in response to different pathogens. Our study provides new insights into the effects of malaria experience on the B cell compartment and the relationships between atMBCs and other B cell populations.

Replicability in measures of attentional set-shifting task performance predicting chronic heavy drinking in rhesus monkeys.

This study was designed to replicate and extend a previous report that the increase in performance of an attentional set-shifting task (ASST) in rhesus monkeys predicted their future alcohol drinking status as a heavy drinker (HD) or non-heavy drinker (NHD). A cohort of 6 young adult male monkeys was trained and tested under the same ASST and then underwent a alcohol self-administration protocol that maintained open-access (22 hours/day) choice of alcohol or water 7 days/week for approximately 6 months. The average improvement in performance in the ASST, as measured by a performance index, was replicated in the cohort of 6 monkeys when compared to the increase in the task performance in a previous cohort of 9 male monkeys. The alcohol self-administration protocol was then used to determine the drinking status (HD: n = 4 or NHD: n = 2) of the replicate cohort, which was accurately predicted by the performance on the ASST. Finally, individuals from both cohorts could be combined based on future drinking status of HD (n = 8) or NHD (n = 7), and the association with pre-alcohol ASST performance remained. Specifically, monkeys that had lower rates of PI improvement were more likely to become HDs. To our knowledge, this is the first study to replicate that deficits in the set-shifting performance can predict chronic heavy alcohol drinking in primates.

Naturally Acquired Humoral Immunity Against Plasmodium falciparum Malaria.

Malaria remains a significant contributor to the global burden of disease, with around 40% of the world's population at risk of Plasmodium infections. The development of an effective vaccine against the malaria parasite would mark a breakthrough in the fight to eradicate the disease. Over time, natural infection elicits a robust immune response against the blood stage of the parasite, providing protection against malaria. In recent years, we have gained valuable insight into the mechanisms by which IgG acts to prevent pathology and inhibit parasite replication, as well as the potential role of immunoglobulin M (IgM) in these processes. Here, we discuss recent advances in our understanding of the mechanisms, acquisition, and maintenance of naturally acquired immunity, and the relevance of these discoveries for the development of a potential vaccine against the blood stage of Plasmodium falciparum.

X-ray diffraction at the National Ignition Facility.

We report details of an experimental platform implemented at the National Ignition Facility to obtain in situ powder diffraction data from solids dynamically compressed to extreme pressures. Thin samples are sandwiched between tamper layers and ramp compressed using a gradual increase in the drive-laser irradiance. Pressure history in the sample is determined using high-precision velocimetry measurements. Up to two independently timed pulses of x rays are produced at or near the time of peak pressure by laser illumination of thin metal foils. The quasi-monochromatic x-ray pulses have a mean wavelength selectable between 0.6 Å and 1.9 Å depending on the foil material. The diffracted signal is recorded on image plates with a typical 2θ x-ray scattering angle uncertainty of about 0.2° and resolution of about 1°. Analytic expressions are reported for systematic corrections to 2θ due to finite pinhole size and sample offset. A new variant of a nonlinear background subtraction algorithm is described, which has been used to observe diffraction lines at signal-to-background ratios as low as a few percent. Variations in system response over the detector area are compensated in order to obtain accurate line intensities; this system response calculation includes a new analytic approximation for image-plate sensitivity as a function of photon energy and incident angle. This experimental platform has been used up to 2 TPa (20 Mbar) to determine the crystal structure, measure the density, and evaluate the strain-induced texturing of a variety of compressed samples spanning periods 2-7 on the periodic table.

EXIT (ex utero intrapartum treatment) in a growth restricted fetus with tracheal atresia.

Congenital high airway obstruction syndrome (CHAOS) encompasses a heterogeneous group of pathologies leading to poor lung development and difficulty oxygenating the newborn after delivery. While previously uniformly fatal, the ex utero intrapartum therapy (EXIT) procedure has provided a method to treat these patients and provide an airway to potentiate survival. We present a patient diagnosed prenatally with CHAOS secondary to tracheal atresia complicated by severe intra-uterine growth restriction (IUGR) who was successfully delivered via an EXIT procedure at 33-weeks. Multidisciplinary care and planning is paramount.

Robotic-Assisted Laparoscopic Abdominal Cerclage Placement During Pregnancy.

STUDY OBJECTIVE: The objective of this study is to report our center's series of robotic-assisted laparoscopic abdominal cerclage (RALAC) placement during pregnancy. DESIGN: Descriptive study (Canadian Task Force classification III). SETTING: Single academic institution. PATIENTS: Patients undergoing RALAC placement during pregnancy. INTERVENTIONS: Eleven patients underwent RALAC. MEASUREMENTS AND MAIN RESULTS: Nine out of 11 (81.8%) primary RALAC procedures resulted in a viable live-born neonate; 8 (72.7%) were born at >34 weeks of gestation. Three patients (27.3%) had preterm premature rupture of membranes on postoperative day one, 2 of whom subsequently underwent a dilation and curettage, and 1 patient carried the pregnancy to 29 weeks and delivered a live-born neonate. Four patients had subsequent pregnancies after placement of a RALAC in the antepartum period, all of whom carried successfully beyond 36 weeks, for a total of 16 pregnancies. Fourteen pregnancies (87.5%) resulted in a live birth, and 13 pregnancies (81.3%) were delivered beyond 34 weeks. CONCLUSION: RALAC is a minimally invasive procedure with an acceptable risk profile and comparable efficacy to traditional open abdominal cerclage. RALAC may be considered an acceptable alternative to open abdominal cerclage in pregnancy, and may be a particularly favorable option in certain settings.

MAOA expression predicts vulnerability for alcohol use.

The role of the monoamines dopamine (DA) and serotonin (5HT) and the monoamine-metabolizing enzyme monoamine oxidase A (MAOA) have been repeatedly implicated in studies of alcohol use and dependence. Genetic investigations of MAOA have yielded conflicting associations between a common polymorphism (MAOA-LPR) and risk for alcohol abuse. The present study provides direct comparison of tissue-specific MAOA expression and the level of alcohol consumption. We analyzed rhesus macaque MAOA (rhMAOA) expression in blood from males before and after 12 months of alcohol self-administration. In addition, nucleus accumbens core (NAc core) and cerebrospinal fluid (CSF) were collected from alcohol access and control (no alcohol access) subjects at the 12-month time point for comparison. The rhMAOA expression level in the blood of alcohol-naive subjects was negatively correlated with subsequent alcohol consumption level. The mRNA expression was independent of rhMAOA-LPR genotype and global promoter methylation. After 12 months of alcohol use, blood rhMAOA expression had decreased in an alcohol dose-dependent manner. Also after 12 months, rhMAOA expression in the NAc core was significantly lower in the heavy drinkers, as compared with control subjects. The CSF measured higher levels of DA and lower DOPAC/DA ratios among the heavy drinkers at the same time point. These results provide novel evidence that blood MAOA expression predicts alcohol consumption and that heavy alcohol use is linked to low MAOA expression in both the blood and NAc core. Together, the findings suggest a mechanistic link between dampened MAOA expression, elevated DA and alcohol abuse.

Stability and maturity of biowaste composts derived by small municipalities: Correlation among physical, chemical and biological indices.

Stability and maturity are important criteria to guarantee the quality of a compost that is applied to agriculture or used as amendment in degraded soils. Although different techniques exist to evaluate stability and maturity, the application of laboratory tests in municipalities in developing countries can be limited due to cost and application complexities. In the composting facilities of such places, some classical low cost on-site tests to monitor the composting process are usually implemented; however, such tests do not necessarily clearly identify conditions of stability and maturity. In this article, we have applied and compared results of stability and maturity tests that can be easily employed on site (i.e. temperature, pH, moisture, electrical conductivity [EC], odor and color), and of tests that require more complex laboratory techniques (volatile solids, C/N ratio, self-heating, respirometric index, germination index [GI]). The evaluation of the above was performed in the field scale using 2 piles of biowaste applied compost. The monitoring period was from day 70 to day 190 of the process. Results showed that the low-cost tests traditionally employed to monitor the composting process on-site, such as temperature, color and moisture, do not provide consistent determinations with the more complex laboratory tests used to assess stability (e.g. respiration index, self-heating, volatile solids). In the case of maturity tests (GI, pH, EC), both the on-site tests (pH, EC) and the laboratory test (GI) provided consistent results. Although, stability was indicated for most of the samples, the maturity tests indicated that products were consistently immature. Thus, a stable product is not necessarily mature. Conclusively, the decision on the quality of the compost in the installations located in developing countries requires the simultaneous use of a combination of tests that are performed both in the laboratory and on-site.

Are we effectively informing patients? A quantitative analysis of on-line patient education resources from the American Society of Neuroradiology.

BACKGROUND AND PURPOSE: The ubiquitous use of the Internet by the public in an attempt to better understand their health care requires the on-line resources written at an appropriate level to maximize comprehension for the average user. The National Institutes of Health and the American Medical Association recommend on-line patient education resources written at a third-to-seventh grade level. We evaluated the readability of the patient education resources provided on the Web site of the American Society of Neuroradiology (http://www.asnr.org/patientinfo/). MATERIALS AND METHODS: All patient education material from the ASNR Web site and the Society of Neurointerventional Surgery Web site were downloaded and evaluated with the computer software, Readability Studio Professional Edition, by using 10 quantitative readability scales: the Flesch Reading Ease, Flesch-Kincaid Grade Level, Simple Measure of Gobbledygook, Coleman-Liau Index, Gunning Fog Index, New Dale-Chall, FORCAST Formula, Fry Graph, Raygor Reading Estimate, and New Fog Count. An unpaired t test was used to compare the readability level of resources available on the American Society of Neuroradiology and the Society of Neurointerventional Surgery Web sites. RESULTS: The 20 individual patient education articles were written at a 13.9 ± 1.4 grade level with only 5% written at <11th grade level. There was no statistical difference between the level of readability of the resources on the American Society of Neuroradiology and Society of Neurointerventional Surgery Web sites. CONCLUSIONS: The patient education resources on these Web sites fail to meet the guidelines of the National Institutes of Health and American Medical Association. Members of the public may fail to fully understand these resources and would benefit from revisions that result in more comprehensible information cast in simpler language.

[Clinical practice guidelines on the diagnosis and treatment of infectious acute diarrhea in children Peru - 2011]. / Guía de práctica clínica sobre el diagnóstico y tratamiento de la diarrea aguda infecciosa en pediatría Perú - 2011.

The Clinical Practice Guidelines cover the Diagnosis and Treatment of Acute Diarrhea in Pediatric Infectious is a consice information about definition, inclusion and exclusion criteria; epidemiology and etiology of infectious diarrhea. The guidelines cover aspects of diagnosis and treatment (dehydration, antibiotics, supportive therapy), nutritional support and other aspects of transferences and prevention.

Guía de práctica clínica sobre el diagnóstico y tratamiento de la diarrea aguda infecciosa en pediatría Perú - 2011 / Clinical practice guidelines on the diagnosis and treatment of infectious acute diarrhea in children Peru - 2011

Guía de Práctica Clínica sobre el Diagnóstico y Tratamiento de la Diarrea Aguda Infecciosa en Pediatría del Perú es una información resumida sobre la definición criterios de inclusión y exclusión epidemiología y etiología de la diarrea infecciosa; considerando aspectos en el dignóstico y tratamiento (desidratación, tratamiento antibiótico, tratamientos de apoyo), soporte nutricional criterios de transferencias y alta y aspectos de prevención.

The Clinical Practice Guidelines cover the Diagnosis and Treatment of Acute Diarrhea in Pediatric Infectious is a consice information about definition, inclusion and exclusion criteria; epidemiology and etiology of infectious diarrhea. The guidelines cover aspects of diagnosis and treatment (dehydration, antibiotics, supportive therapy), nutritional support and other aspects of transferences and prevention.

Harmonization of internal dosimetry procedures in Latin America--ARCAL/IAEA project.

Under the auspices of the Regional Coordination Agreement for Latin America, representatives of the eight member states have participated in a project to improve radiological protection for workers exposed to unsealed sources of radiation. The design of the project was based on information obtained from a questionnaire circulated among the participants, from which the initial status of internal dosimetry services in each country was characterised. The objective of the project is to harmonize internal dosimetry procedures, with reference to International Atomic Energy Agency recommendations. After the implementation of new procedures and personnel training, four intercomparison exercises were carried out: measurement of iodine in thyroid phantoms, measurement of gamma emitters in urine samples, measurement of beta emitters in urine samples and internal dose assessments. This project has resulted in important improvements in internal dosimetry services in the region.

Polymorphism in 1908STR1934 locus of the 3. UTR of the Nramp1 bovine gene in eight cattle breeds

The Nramp1 gene has been associated with natural resistance to intracellular microorganisms in several species including bovine. Recent evidence suggests an association between polymorphism in the 3. untranslated region (3. UTR) of this gene with resistance/susceptibility (R/S) to Brucella abortus as determined in vivo and in vitro. In this study we tested for the variability of the short tandem repeat (STR) within the 3. UTR of Nramp1 in six breeds of Colombian creole cattle (CCC) and compared the genotypes with those of Holstein and Brahman, which were recently introduced into this country. In CCC as well as in Holstein we found the allele 175 fixed in all populations. In Brahman, 175 allele was also present with a frequency of 0.467 but additionally, in this breed there appeared five other alleles and among them two previously unreported: 183 y 185; also was found the allele 189 in the Colombian creole Harton del Valle cattle, which is not previously reported. Together these results suggest that the 175 allele in the 3. UTR Nramp1 may be an ancestral allele in cattle and if this is true the association previously reported with the R/S trait requires further evaluation.