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1.
Proc Natl Acad Sci U S A ; 120(8): e2202388120, 2023 02 21.
Article in English | MEDLINE | ID: mdl-36780524

ABSTRACT

Climate change is radically altering coral reef ecosystems, mainly through increasingly frequent and severe bleaching events. Yet, some reefs have exhibited higher thermal tolerance after bleaching severely the first time. To understand changes in thermal tolerance in the eastern tropical Pacific (ETP), we compiled four decades of temperature, coral cover, coral bleaching, and mortality data, including three mass bleaching events during the 1982 to 1983, 1997 to 1998 and 2015 to 2016 El Niño heatwaves. Higher heat resistance in later bleaching events was detected in the dominant framework-building genus, Pocillopora, while other coral taxa exhibited similar susceptibility across events. Genetic analyses of Pocillopora spp. colonies and their algal symbionts (2014 to 2016) revealed that one of two Pocillopora lineages present in the region (Pocillopora "type 1") increased its association with thermotolerant algal symbionts (Durusdinium glynnii) during the 2015 to 2016 heat stress event. This lineage experienced lower bleaching and mortality compared with Pocillopora "type 3", which did not acquire D. glynnii. Under projected thermal stress, ETP reefs may be able to preserve high coral cover through the 2060s or later, mainly composed of Pocillopora colonies that associate with D. glynnii. However, although the low-diversity, high-cover reefs of the ETP could illustrate a potential functional state for some future reefs, this state may only be temporary unless global greenhouse gas emissions and resultant global warming are curtailed.


Subject(s)
Anthozoa , Coral Reefs , Animals , Ecosystem , Heat-Shock Response , Oceans and Seas
2.
Glob Chang Biol ; 30(6): e17371, 2024 Jun.
Article in English | MEDLINE | ID: mdl-38863267

ABSTRACT

As the balance between erosional and constructive processes on coral reefs tilts in favor of framework loss under human-induced local and global change, many reef habitats worldwide degrade and flatten. The resultant generation of coral rubble and the beds they form can have lasting effects on reef communities and structural complexity, threatening the continuity of reef ecological functions and the services they provide. To comprehensively capture changing framework processes and predict their evolution in the context of climate change, heavily colonized rubble fragments were exposed to ocean acidification (OA) conditions for 55 days. Controlled diurnal pH oscillations were incorporated in the treatments to account for the known impact of diel carbonate chemistry fluctuations on calcification and dissolution response to OA. Scenarios included contemporary pH (8.05 ± 0.025 diel fluctuation), elevated OA (7.90 ± 0.025), and high OA (7.70 ± 0.025). We used a multifaceted approach, combining chemical flux analyses, mass alteration measurements, and computed tomography scanning images to measure total and chemical bioerosion, as well as chemically driven secondary calcification. Rates of net carbonate loss measured in the contemporary conditions (1.36 kg m-2 year-1) were high compared to literature and increased in OA scenarios (elevated: 1.84 kg m-2 year-1 and high: 1.59 kg m-2 year-1). The acceleration of these rates was driven by enhanced chemical dissolution and reduced secondary calcification. Further analysis revealed that the extent of these changes was contingent on the density of the coral skeleton, in which the micro- and macroborer communities reside. Findings indicated that increased mechanical bioerosion rates occurred in rubble with lower skeletal density, which is of note considering that corals form lower-density skeletons under OA. These direct and indirect effects of OA on chemical and mechanical framework-altering processes will influence the permanence of this crucial habitat, carrying implications for biodiversity and reef ecosystem function.


Subject(s)
Anthozoa , Climate Change , Coral Reefs , Seawater , Anthozoa/physiology , Anthozoa/chemistry , Animals , Seawater/chemistry , Hydrogen-Ion Concentration , Calcification, Physiologic , Carbonates/chemistry , Carbonates/analysis , Oceans and Seas , Ocean Acidification
3.
Radiographics ; 44(2): e230152, 2024 02.
Article in English | MEDLINE | ID: mdl-38206833

ABSTRACT

Radiation therapy is fundamental in the treatment of cancer. Imaging has always played a central role in radiation oncology. Integrating imaging technology into irradiation devices has increased the precision and accuracy of dose delivery and decreased the toxic effects of the treatment. Although CT has become the standard imaging modality in radiation therapy, the development of recently introduced next-generation imaging techniques has improved diagnostic and therapeutic decision making in radiation oncology. Functional and molecular imaging techniques, as well as other advanced imaging modalities such as SPECT, yield information about the anatomic and biologic characteristics of tumors for the radiation therapy workflow. In clinical practice, they can be useful for characterizing tumor phenotypes, delineating volumes, planning treatment, determining patients' prognoses, predicting toxic effects, assessing responses to therapy, and detecting tumor relapse. Next-generation imaging can enable personalization of radiation therapy based on a greater understanding of tumor biologic factors. It can be used to map tumor characteristics, such as metabolic pathways, vascularity, cellular proliferation, and hypoxia, that are known to define tumor phenotype. It can also be used to consider tumor heterogeneity by highlighting areas at risk for radiation resistance for focused biologic dose escalation, which can impact the radiation planning process and patient outcomes. The authors review the possible contributions of next-generation imaging to the treatment of patients undergoing radiation therapy. In addition, the possible roles of radio(geno)mics in radiation therapy, the limitations of these techniques, and hurdles in introducing them into clinical practice are discussed. ©RSNA, 2024 Test Your Knowledge questions for this article are available in the supplemental material.


Subject(s)
Biological Products , Neoplasms , Radiation Oncology , Humans , Diagnostic Imaging , Neoplasms/diagnostic imaging , Neoplasms/radiotherapy , Radiotherapy Planning, Computer-Assisted/methods
4.
J Pediatr Gastroenterol Nutr ; 79(4): 841-849, 2024 Oct.
Article in English | MEDLINE | ID: mdl-39175183

ABSTRACT

OBJECTIVES: Food protein-induced enterocolitis syndrome (FPIES) is a severe type of non-IgE (immunoglobulin E)-mediated (NIM) food allergy, with cow's milk (CM) being the most common offending food. The relationship between the gut microbiota and its metabolites with the inflammatory process in infants with CM FPIES is unknown, although evidence suggests a microbial dysbiosis in NIM patients. This study was performed to contribute to the knowledge of the interaction between the gut microbiota and its derived metabolites with the local immune system in feces of infants with CM FPIES at diagnosis. METHODS: Twelve infants with CM FPIES and a matched healthy control group were recruited and the gut microbiota was investigated by 16S amplicon and shotgun sequencing. Fatty acids (FAs) were measured by gas chromatography, while immune factors were determined by enzyme-linked immunosorbent assay and Luminex technology. RESULTS: A specific pattern of microbiota in the gut of CM FPIES patients was found, characterized by a high abundance of enterobacteria. Also, an intense excretion of FAs in the feces of these infants was observed. Furthermore, correlations were found between fecal bifidobacteria and immune factors. CONCLUSION: These fecal determinations may be useful to gain insight into the pathophysiology of this syndrome and should be taken in consideration for future studies of FPIES patients.


Subject(s)
Enterobacteriaceae , Enterocolitis , Feces , Gastrointestinal Microbiome , Milk Hypersensitivity , Humans , Infant , Male , Female , Milk Hypersensitivity/microbiology , Milk Hypersensitivity/immunology , Feces/microbiology , Enterobacteriaceae/isolation & purification , Enterocolitis/microbiology , Animals , Case-Control Studies , Fatty Acids/metabolism , Milk/microbiology , Dysbiosis/microbiology
5.
J Pediatr Gastroenterol Nutr ; 78(4): 836-845, 2024 Apr.
Article in English | MEDLINE | ID: mdl-38344848

ABSTRACT

OBJECTIVE: Analyze fecal and blood samples at point of diagnosis in IgE mediated cow's milk protein allergy (CMPA) and non-IgE mediated (NIM)-CMPA patients to look for potential new biomarkers. PATIENTS AND METHODS: Fourteen patients with IgE mediated CMPA and 13 with NIM-CMPA were recruited in three hospitals in the north of Spain, and were compared with 25 infants from a control group of the same age range. To characterize intestinal microbiota, 16S rDNA gene and internal transcribed spacer amplicons of bifidobacteria were sequenced with Illumina technology. Fatty acids were analyzed by gas chromatography, meanwhile intestinal inflammation markers were quantified by enzyme-linked immunosorbent assay and a multiplex system. Immunological analysis of blood was performed by flow cytometry. RESULTS: The fecal results obtained in the NIM-CMPA group stand out. Among them, a significant reduction in the abundance of Bifidobacteriaceae and Bifidobacterium sequences with respect to controls was observed. Bifidobacterial species were also different, highlighting the lower abundance of Bifidobacterium breve sequences. Fecal calprotectin levels were found to be significantly elevated in relation to IgE mediated patients. Also, a higher excretion of IL-10 and a lower excretion of IL-1ra and platelet derived growth factor-BB was found in NIM-CMPA patients. CONCLUSIONS: The differential fecal parameters found in NIM-CMPA patients could be useful in the diagnosis of NIM food allergy to CM proteins.


Subject(s)
Food Hypersensitivity , Gastrointestinal Microbiome , Milk Hypersensitivity , Infant , Female , Animals , Humans , Cattle , Immunoglobulin E , Milk Hypersensitivity/diagnosis , Milk Proteins
6.
Mol Ecol ; 32(16): 4677-4694, 2023 08.
Article in English | MEDLINE | ID: mdl-37317893

ABSTRACT

Corals are important models for understanding invertebrate host-microbe interactions; however, to fully discern mechanisms involved in these relationships, experimental approaches for manipulating coral-bacteria associations are needed. Coral-associated bacteria affect holobiont health via nutrient cycling, metabolic exchanges and pathogen exclusion, yet it is not fully understood how bacterial community shifts affect holobiont health and physiology. In this study, a combination of antibiotics (ampicillin, streptomycin and ciprofloxacin) was used to disrupt the bacterial communities of 14 colonies of the reef framework-building corals Pocillopora meandrina and P. verrucosa, originally collected from Panama and hosting diverse algal symbionts (family Symbiodiniaceae). Symbiodiniaceae photochemical efficiencies and holobiont oxygen consumption (as proxies for coral health) were measured throughout a 5-day exposure. Antibiotics altered bacterial community composition and reduced alpha and beta diversity, however, several bacteria persisted, leading to the hypothesis that these bacteria are either antibiotics resistant or occupy internal niches that are shielded from antibiotics. While antibiotics did not affect Symbiodiniaceae photochemical efficiency, antibiotics-treated corals had lower oxygen consumption rates. RNAseq revealed that antibiotics increased expression of Pocillopora immunity and stress response genes at the expense of cellular maintenance and metabolism functions. Together, these results reveal that antibiotic disruption of corals' native bacteria negatively impacts holobiont health by decreasing oxygen consumption and activating host immunity without directly impairing Symbiodiniaceae photosynthesis, underscoring the critical role of coral-associated bacteria in holobiont health. They also provide a baseline for future experiments that manipulate Pocillopora corals' symbioses by first reducing the diversity and complexity of coral-associated bacteria.


Subject(s)
Anthozoa , Dinoflagellida , Microbiota , Animals , Anthozoa/genetics , Anthozoa/microbiology , Anti-Bacterial Agents/pharmacology , Microbiota/genetics , Symbiosis/genetics , Bacteria/genetics , Oxygen Consumption , Dinoflagellida/genetics , Gene Expression , Coral Reefs
7.
Plant Biotechnol J ; 19(1): 51-63, 2021 01.
Article in English | MEDLINE | ID: mdl-32594636

ABSTRACT

Effective and durable disease resistance for bacterial blight (BB) of rice is a continuous challenge due to the evolution and adaptation of the pathogen, Xanthomonas oryzae pv. oryzae (Xoo), on cultivated rice varieties. Fundamental to this pathogens' virulence is transcription activator-like (TAL) effectors that activate transcription of host genes and contribute differently to pathogen virulence, fitness or both. Host plant resistance is predicted to be more durable if directed at strategic virulence factors that impact both pathogen virulence and fitness. We characterized Tal7b, a minor-effect virulence factor that contributes incrementally to pathogen virulence in rice, is a fitness factor to the pathogen and is widely present in geographically diverse strains of Xoo. To identify sources of resistance to this conserved effector, we used a highly virulent strain carrying a plasmid borne copy of Tal7b to screen an indica multi-parent advanced generation inter-cross (MAGIC) population. Of 18 QTL revealed by genome-wide association studies and interval mapping analysis, six were specific to Tal7b (qBB-tal7b). Overall, 150 predicted Tal7b gene targets overlapped with qBB-tal7b QTL. Of these, 21 showed polymorphisms in the predicted effector binding element (EBE) site and 23 lost the EBE sequence altogether. Inoculation and bioinformatics studies suggest that the Tal7b target in one of the Tal7b-specific QTL, qBB-tal7b-8, is a disease susceptibility gene and that the resistance mechanism for this locus may be through loss of susceptibility. Our work demonstrates that minor-effect virulence factors significantly contribute to disease and provide a potential new approach to identify effective disease resistance.


Subject(s)
Oryza , Xanthomonas , Bacterial Proteins/genetics , Bacterial Proteins/metabolism , Disease Resistance/genetics , Gene Expression Regulation, Plant , Genome-Wide Association Study , Oryza/genetics , Oryza/metabolism , Plant Diseases/genetics , Quantitative Trait Loci , Virulence Factors/genetics
8.
New Phytol ; 232(4): 1540-1548, 2021 11.
Article in English | MEDLINE | ID: mdl-34478160

ABSTRACT

To more sustainably mitigate the impact of crop diseases on plant health and productivity, there is a need for broader spectrum, long-lasting resistance traits. Defense response (DR) genes, located throughout the genome, participate in cellular and system-wide defense mechanisms to stave off infection by diverse pathogens. This multigenic resistance avoids rapid evolution of a pathogen to overcome host resistance. DR genes reside within resistance-associated quantitative trait loci (QTL), and alleles of DR genes in resistant varieties are more active during pathogen attack relative to susceptible haplotypes. Differential expression of DR genes results from polymorphisms in their regulatory regions, that includes cis-regulatory elements such as transcription factor binding sites as well as features that influence epigenetic structural changes to modulate chromatin accessibility during infection. Many of these elements are found in clusters, known as cis-regulatory modules (CRMs), which are distributed throughout the host genome. Regulatory regions involved in plant-pathogen interactions may also contain pathogen effector binding elements that regulate DR gene expression, and that, when mutated, result in a change in the plants' response. We posit that CRMs and the multiple regulatory elements that comprise them are potential targets for marker-assisted breeding for broad-spectrum, durable disease resistance.


Subject(s)
Plant Breeding , Quantitative Trait Loci , Disease Resistance/genetics , Haplotypes , Plant Diseases/genetics , Plants/genetics , Quantitative Trait Loci/genetics
9.
Br J Haematol ; 188(5): 661-673, 2020 03.
Article in English | MEDLINE | ID: mdl-31573078

ABSTRACT

Rituximab is a standard treatment for non-Hodgkin diffuse large B-cell (DLBCL) and follicular (FL) lymphomas. A subcutaneous formulation was developed to improve the resource use of intravenous rituximab, with comparable efficacy and safety profiles except for increased administration-related reactions (ARRs). MabRella was a phase IIIb trial to assess the safety of switching from intravenous to subcutaneous administration of rituximab during first-line induction/maintenance for DLBCL or FL, focusing on ARRs. Efficacy, satisfaction and quality of life were also assessed. Patients received subcutaneous rituximab plus standard induction chemotherapy for DLBCL or FL for 4-7 cycles, and/or every 2 months maintenance monotherapy for FL for 6-12 cycles. The study included 140 patients: DLBCL, n = 29; FL, n = 111. Ninety-five percent of patients experienced adverse events, reaching grade ≥3 in 38·6% and were serious in 30·0%. AARs occurred in 48·6%, mostly (84·9%) at the injection site, with only 2·1% of patients reaching grade 3. The end-of-induction complete/unconfirmed complete response rate was 69·6%. After a median follow-up of 33·5 months, median disease-/event-/progression-free and overall survivals were not attained. The Rituximab Administration Satisfaction Questionnaire showed improvements in overall satisfaction and the EuroQoL-5D a good quality-of-life perception at induction/maintenance end. Therefore, switching to subcutaneous rituximab showed no new safety issues and maintained efficacy with improved satisfaction and quality of life.


Subject(s)
Lymphoma, Large B-Cell, Diffuse/drug therapy , Lymphoma, Large B-Cell, Diffuse/mortality , Quality of Life , Rituximab/administration & dosage , Safety , Administration, Intravenous , Adolescent , Adult , Aged , Aged, 80 and over , Disease-Free Survival , Female , Humans , Infusions, Subcutaneous , Male , Middle Aged , Rituximab/adverse effects , Spain/epidemiology , Survival Rate
10.
Glob Chang Biol ; 26(7): 3880-3890, 2020 07.
Article in English | MEDLINE | ID: mdl-32315464

ABSTRACT

Coral reefs worldwide are threatened by thermal stress caused by climate change. Especially devastating periods of coral loss frequently occur during El Niño-Southern Oscillation (ENSO) events originating in the Eastern Tropical Pacific (ETP). El Niño-induced thermal stress is considered the primary threat to ETP coral reefs. An increase in the frequency and intensity of ENSO events predicted in the coming decades threatens a pan-tropical collapse of coral reefs. During the 1982-1983 El Niño, most reefs in the Galapagos Islands collapsed, and many more in the region were decimated by massive coral bleaching and mortality. However, after repeated thermal stress disturbances, such as those caused by the 1997-1998 El Niño, ETP corals reefs have demonstrated regional persistence and resiliency. Using a 44 year dataset (1970-2014) of live coral cover from the ETP, we assess whether ETP reefs exhibit the same decline as seen globally for other reefs. Also, we compare the ETP live coral cover rate of change with data from the maximum Degree Heating Weeks experienced by these reefs to assess the role of thermal stress on coral reef survival. We find that during the period 1970-2014, ETP coral cover exhibited temporary reductions following major ENSO events, but no overall decline. Further, we find that ETP reef recovery patterns allow coral to persist under these El Niño-stressed conditions, often recovering from these events in 10-15 years. Accumulative heat stress explains 31% of the overall annual rate of change of living coral cover in the ETP. This suggests that ETP coral reefs have adapted to thermal extremes to date, and may have the ability to adapt to near-term future climate-change thermal anomalies. These findings for ETP reef resilience may provide general insights for the future of coral reef survival and recovery elsewhere under intensifying El Niño scenarios.


Subject(s)
Anthozoa , Coral Reefs , Animals , Climate Change , Ecuador , El Nino-Southern Oscillation
11.
Am J Physiol Gastrointest Liver Physiol ; 314(2): G247-G255, 2018 02 01.
Article in English | MEDLINE | ID: mdl-29146676

ABSTRACT

As the largest interface between the outside and internal milieu, the intestinal epithelium constitutes the first structural component facing potential luminal threats to homeostasis. This single-cell layer is the epicenter of a tightly regulated communication network between external and internal factors that converge to prime defensive responses aimed at limiting antigen penetration and the maintenance of intestinal barrier function. The defensive role developed by intestinal epithelial cells (IEC) relies largely on the variety of receptors they express at both extracellular (apical and basolateral) and intracellular compartments, and the capacity of IEC to communicate with immune and nervous systems. IEC recognize pathogen-associated molecules by innate receptors that promote the production of mucus, antimicrobial substances, and immune mediators. Epithelial cells are key to oral tolerance maintenance and also participate in adaptive immunity through the expression of immunoglobulin (Ig) receptors and by promoting local Ig class switch recombination. In IEC, different types of antigens can be sensed by multiple immune receptors that share signaling pathways to assure effective responses. Regulated defensive activity maintains intestinal homeostasis, whereas a breakdown in the control of epithelial immunity can increase the intestinal passage of luminal content and microbial invasion, leading to inflammation and tissue damage. In this review, we provide an updated overview of the type of immune receptors present in the human intestinal epithelium and the responses generated to promote effective barrier function and maintain mucosal homeostasis.


Subject(s)
Epithelial Cells/immunology , Immunity, Mucosal , Intestinal Mucosa/immunology , Receptors, Immunologic/immunology , Adaptive Immunity , Animals , Epithelial Cells/metabolism , Host-Pathogen Interactions/immunology , Humans , Immune Tolerance , Immunity, Innate , Intestinal Mucosa/metabolism , Ligands , Receptors, Immunologic/metabolism , Signal Transduction
12.
Plant Biotechnol J ; 2018 Feb 06.
Article in English | MEDLINE | ID: mdl-29406604

ABSTRACT

Quantitative trait loci (QTL) that confer broad-spectrum resistance (BSR), or resistance that is effective against multiple and diverse plant pathogens, have been elusive targets of crop breeding programmes. Multiparent advanced generation intercross (MAGIC) populations, with their diverse genetic composition and high levels of recombination, are potential resources for the identification of QTL for BSR. In this study, a rice MAGIC population was used to map QTL conferring BSR to two major rice diseases, bacterial leaf streak (BLS) and bacterial blight (BB), caused by Xanthomonas oryzae pathovars (pv.) oryzicola (Xoc) and oryzae (Xoo), respectively. Controlling these diseases is particularly important in sub-Saharan Africa, where no sources of BSR are currently available in deployed varieties. The MAGIC founders and lines were genotyped by sequencing and phenotyped in the greenhouse and field by inoculation with multiple strains of Xoc and Xoo. A combination of genomewide association studies (GWAS) and interval mapping analyses revealed 11 BSR QTL, effective against both diseases, and three pathovar-specific QTL. The most promising BSR QTL (qXO-2-1, qXO-4-1 and qXO-11-2) conferred resistance to more than nine Xoc and Xoo strains. GWAS detected 369 significant SNP markers with distinguishable phenotypic effects, allowing the identification of alleles conferring disease resistance and susceptibility. The BSR and susceptibility QTL will improve our understanding of the mechanisms of both resistance and susceptibility in the long term and will be immediately useful resources for rice breeding programmes.

13.
Gut ; 66(9): 1537-1538, 2017 09.
Article in English | MEDLINE | ID: mdl-28082316

ABSTRACT

OBJECTIVE: Micro-RNAs (miRNAs) play a crucial role in controlling intestinal epithelial barrier function partly by modulating the expression of tight junction (TJ) proteins. We have previously shown differential messenger RNA (mRNA) expression correlated with ultrastructural abnormalities of the epithelial barrier in patients with diarrhoea-predominant IBS (IBS-D). However, the participation of miRNAs in these differential mRNA-associated findings remains to be established. Our aims were (1) to identify miRNAs differentially expressed in the small bowel mucosa of patients with IBS-D and (2) to explore putative target genes specifically involved in epithelial barrier function that are controlled by specific dysregulated IBS-D miRNAs. DESIGN: Healthy controls and patients meeting Rome III IBS-D criteria were studied. Intestinal tissue samples were analysed to identify potential candidates by: (a) miRNA-mRNA profiling; (b) miRNA-mRNA pairing analysis to assess the co-expression profile of miRNA-mRNA pairs; (c) pathway analysis and upstream regulator identification; (d) miRNA and target mRNA validation. Candidate miRNA-mRNA pairs were functionally assessed in intestinal epithelial cells. RESULTS: IBS-D samples showed distinct miRNA and mRNA profiles compared with healthy controls. TJ signalling was associated with the IBS-D transcriptional profile. Further validation of selected genes showed consistent upregulation in 75% of genes involved in epithelial barrier function. Bioinformatic analysis of putative miRNA binding sites identified hsa-miR-125b-5p and hsa-miR-16 as regulating expression of the TJ genes CGN (cingulin) and CLDN2 (claudin-2), respectively. Consistently, protein expression of CGN and CLDN2 was upregulated in IBS-D, while the respective targeting miRNAs were downregulated. In addition, bowel dysfunction, perceived stress and depression and number of mast cells correlated with the expression of hsa-miR-125b-5p and hsa-miR-16 and their respective target proteins. CONCLUSIONS: Modulation of the intestinal epithelial barrier function in IBS-D involves both transcriptional and post-transcriptional mechanisms. These molecular mechanisms include miRNAs as master regulators in controlling the expression of TJ proteins and are associated with major clinical symptoms.


Subject(s)
Claudins , Diarrhea/metabolism , Irritable Bowel Syndrome , Jejunum , Membrane Proteins , MicroRNAs/genetics , Microfilament Proteins , Adult , Claudins/genetics , Claudins/metabolism , Down-Regulation , Female , Gene Expression Profiling , Humans , Intestinal Mucosa/metabolism , Irritable Bowel Syndrome/genetics , Irritable Bowel Syndrome/metabolism , Irritable Bowel Syndrome/pathology , Irritable Bowel Syndrome/physiopathology , Jejunum/metabolism , Jejunum/pathology , Jejunum/physiopathology , Male , Membrane Proteins/genetics , Membrane Proteins/metabolism , Microfilament Proteins/genetics , Microfilament Proteins/metabolism , Middle Aged , Up-Regulation
14.
J Gastroenterol Hepatol ; 32(1): 53-63, 2017 Jan.
Article in English | MEDLINE | ID: mdl-27087165

ABSTRACT

Irritable bowel syndrome (IBS) is one of the most prevalent gastrointestinal disorders in developed countries. Its etiology remains unknown; however, a common finding, regardless of IBS subtype, is the presence of altered intestinal barrier. In fact, signaling and location of cell-to-cell adhesion proteins, in connection with increased immune activity, seem abnormal in the intestinal epithelium of IBS patients. Despite that most research is performed on distal segments of the intestine, altered permeability has been reported in both, the small and the large bowel of all IBS subtypes. The small intestine carries out digestion and nutrient absorption and is also the site where the majority of immune responses to luminal antigens takes place. In fact, the upper intestine is more exposed to environmental antigens than the colon and is also a site of symptom generation. Recent studies have revealed small intestinal structural alterations of the epithelial barrier and mucosal immune activation in association with intestinal dysfunction, suggesting the commitment of the intestine as a whole in the pathogenesis of IBS. This review summarizes the most recent findings on mucosal barrier alterations and its relationship to symptoms arising from the small intestine in IBS, including epithelial structural abnormalities, mucosal immune activation, and microbial dysbiosis, further supporting the hypothesis of an organic origin of IBS.


Subject(s)
Intestinal Mucosa/immunology , Intestinal Mucosa/physiopathology , Intestine, Small/immunology , Intestine, Small/physiopathology , Irritable Bowel Syndrome/etiology , Cell Adhesion Molecules , Cell Membrane Permeability , Digestion , Humans , Intestinal Absorption , Intestinal Mucosa/metabolism , Intestinal Mucosa/pathology , Intestine, Small/metabolism
15.
Gut ; 64(9): 1379-88, 2015 Sep.
Article in English | MEDLINE | ID: mdl-25209656

ABSTRACT

BACKGROUND AND AIMS: Altered intestinal barrier is associated with immune activation and clinical symptoms in diarrhoea-predominant IBS (IBS-D). Increased mucosal antigen load may induce specific responses; however, local antibody production and its contribution to IBS aetiopathogenesis remain undefined. This study evaluated the role of humoral activity in IBS-D. METHODS: A single mucosal jejunal biopsy, luminal content and blood were obtained from healthy volunteers (H; n=30) and IBS-D (n=49; Rome III criteria) participants. Intraepithelial lymphocytes, mast cells, B lymphocytes and plasma cells were studied by imaging techniques. Differential gene expression and pathway analysis were assessed by microarray and PCR techniques. Blood and luminal immunoglobulins (Igs) were quantified. Gastrointestinal symptoms, respiratory atopy and stress and depression were also recorded. RESULTS: Patients with IBS-D showed a higher number and activation of mucosal B lymphocytes and plasma cells (p<0.05). Mast cell density was increased in patients with IBS-D (non-atopic) and in close proximity to plasma cells (p<0.05). Microarray profiling identified differential humoral activity in IBS-D, involving proliferation and activation of B lymphocytes and Igs production (p<0.001). Mucosal humoral activity was higher in IBS-D, with upregulation of germline transcripts and Ig genes (1.3-fold-1.7-fold increase; p<0.05), and increased IgG(+) cells and luminal IgG compared with H (p<0.05), with no differences in blood. Biological markers of humoral activity correlated positively with bowel movements, stool form and depression. CONCLUSIONS: Enhanced small bowel humoral immunity is a distinctive feature of IBS-D. Mucosal Ig production contributes to local inflammation and clinical manifestations in IBS-D.


Subject(s)
Immunity, Humoral/immunology , Intestinal Mucosa/immunology , Irritable Bowel Syndrome/immunology , Irritable Bowel Syndrome/physiopathology , Jejunum/pathology , Adult , Analysis of Variance , Biopsy, Needle , Case-Control Studies , Diarrhea/immunology , Diarrhea/pathology , Disease Progression , Female , Fluorescent Antibody Technique , Humans , Immunoglobulins/immunology , Immunoglobulins/metabolism , Immunohistochemistry , Intestinal Mucosa/pathology , Jejunum/immunology , Male , Microscopy, Electron, Transmission/methods , Middle Aged , Prospective Studies , Severity of Illness Index , Statistics, Nonparametric , T-Lymphocytes/immunology , T-Lymphocytes/metabolism , Young Adult
16.
BMC Infect Dis ; 14: 33, 2014 Jan 18.
Article in English | MEDLINE | ID: mdl-24438336

ABSTRACT

BACKGROUND: Control programs have been executed in an attempt to reduce vertical transmission and the severity of congenital infection in regions with a high incidence of toxoplasmosis in pregnant women. We aimed to evaluate whether treatment of pregnant women with spiramycin associated with a lack of monitoring for toxoplasmosis seroconversion affects the prognosis of patients. METHODS: We performed a prospective cohort study with 246 newborns (NB) at risk for congenital toxoplasmosis in Goiânia (Brazil) between October 2003 and October 2011. We analyzed the efficacy of maternal treatment with spiramycin. RESULTS: A total of 40.7% (66/162) of the neonates were born seriously infected. Vertical transmission associated with reactivation during pregnancy occurred in 5.5% (9/162) of the NB, with one showing severe infection (systemic). The presence of specific immunoglobulins (fetal IgM and NB IgA) suggested the worst prognosis. Treatment of pregnant women by spiramycin resulted in reduced vertical transmission. When infected pregnant women did not undergo proper treatment, the risk of severe infection (neural-optical) in NB was significantly increased. Fetal IgM was associated with ocular impairment in 48.0% (12/25) of the fetuses and neonatal IgA-specific was related to the neuro-ophthalmologic and systemic forms of the disease. When acute toxoplasmosis was identified in the postpartum period, a lack of monitoring of seronegative pregnant women resulted in a higher risk of severe congenital infection. CONCLUSION: Treatment of pregnant women with spiramycin reduces the possibility of transmission of infection to the fetus. However, a lack of proper treatment is associated with the onset of the neural-optical form of congenital infection. Primary preventive measures should be increased for all pregnant women during the prenatal period and secondary prophylaxis through surveillance of seroconversion in seronegative pregnant woman should be introduced to reduce the severity of congenital infection in the environment.


Subject(s)
Coccidiostats/therapeutic use , Infectious Disease Transmission, Vertical/prevention & control , Pregnancy Complications, Infectious/drug therapy , Spiramycin/therapeutic use , Toxoplasmosis, Congenital/prevention & control , Adult , Brazil , Cohort Studies , Drug Monitoring , Female , Humans , Immunoglobulin A/blood , Infant, Newborn , Pregnancy , Pregnancy Complications, Infectious/diagnosis , Prenatal Care , Prognosis , Prospective Studies , Serologic Tests , Toxoplasmosis/drug therapy , Toxoplasmosis, Congenital/blood
17.
BMC Infect Dis ; 14: 349, 2014 Jun 24.
Article in English | MEDLINE | ID: mdl-24961630

ABSTRACT

BACKGROUND: The different laboratory methods used in the diagnosis of congenital toxoplasmosis have variable sensitivity and specificity. There is no evidence to prove that maternal treatment reduces the risk of fetal infection. The purpose of this study was to assess methods for the confirmation of congenital toxoplasmosis after maternal treatment with spiramycin during pregnancy, and to evaluate the effect of this treatment on clinical manifestations of the disease in newborns (NB). METHODS: This was a community-based, cross-sectional study of acute toxoplasmosis in newborns at risk of acquiring congenital infection. Participating newborns were born in the Clinical Hospital Maternity Ward of the Federal University of Goiás. Eligible participants were divided into 2 groups: group 1 consisted of 44 newborns born to mothers treated with spiramycin during pregnancy and group 2 consisted of 24 newborns born to mothers not treated with spiramycin during pregnancy because the diagnosis of toxoplasmosis was not performed. The sensitivity and specifity of PCR for T. gondii DNA in peripheral blood and serological testing for specific anti-T. gondii IgM and IgA, and the effects of maternal spiramycin treatment on these parameters, were determined by associating test results with clinical manifestations of disease. RESULTS: The sensitivity of the markers (T. gondii DNA detected by PCR, and the presence of specific anti-T. gondii IgM and IgA) for congenital toxoplasmosis was higher in group 2 than in group 1 (31.6, 68.4, 36.8% and 3.7, 25.9, 11.1% respectively). Even with a low PCR sensitivity, the group 2 results indicate the importance of developing new techniques for the diagnosis of congenital toxoplasmosis in newborns. Within group 1, 70.4% of the infected newborns were asymptomatic and, in group 2, 68.4% showed clinical manifestations of congenital toxoplasmosis. CONCLUSIONS: The higher proportion of infants without clinical symptoms in group 1 (70.4%) suggests the maternal treatment with spiramycin delays fetal infection, reducing the clinical sequelae of the disease in newborns. Given the low sensitivity of the tests used, when there is suspicion of congenital transmission several serological and parasitological tests are required in order to confirm or exclude congenital toxoplasmosis in newborns.


Subject(s)
Coccidiostats/administration & dosage , Pregnancy Complications, Parasitic/diagnosis , Spiramycin/administration & dosage , Toxoplasmosis, Congenital/diagnosis , Adult , Animals , Cross-Sectional Studies , DNA, Protozoan/analysis , Female , Humans , Infant , Infant, Newborn , Infectious Disease Transmission, Vertical/prevention & control , Polymerase Chain Reaction , Pregnancy , Pregnancy Complications, Parasitic/drug therapy , Prenatal Diagnosis , Sensitivity and Specificity , Serologic Tests , Toxoplasma/genetics , Toxoplasma/immunology , Toxoplasma/isolation & purification , Toxoplasmosis, Congenital/drug therapy
18.
Children (Basel) ; 11(9)2024 Sep 12.
Article in English | MEDLINE | ID: mdl-39334645

ABSTRACT

BACKGROUND: One of the most common food allergies in the pediatric population is allergy to cow's milk protein (CMPA). Treatment consists of avoiding cow's milk proteins in lactating mothers and/or using therapeutic formulas based on hydrolysates or vegetable formulas. In infants with CMPA at diagnosis, a different gut microbial profile has been found compared to healthy children, with a reduction in beneficial bacteria. The aim of this study was to evaluate changes in the gut microbiota profile and its metabolites, dietary patterns and anthropometric variables in a pediatric cohort with CMPA after six months on a restrictive diet compared to healthy controls. METHODS: In total, 21 patients diagnosed with CMPA and a control group of 24 healthy infants participated in this study. The fecal microbiota of all participants were investigated by metataxonomic analysis of 16S rDNA amplicons, and fecal short-chain fatty acids were measured by gas chromatography. Epidemiological assessment and dietary questionnaires were carried out for both groups. RESULTS: Regarding growth, no significant differences were found, but differences in dietary intake of some macro- and micronutrients were observed. Patients who were breastfed at six months had higher bifidobacteria and lipid intakes than patients fed with hydrolyzed formulas. CONCLUSIONS: Although the growth of CMPA infants fed with therapeutic formula is similar to breastfed CMPA infants, there are differences in microbiota composition and macronutrient intake that underline the importance of continued breastfeeding in CMPA cases.

19.
PLoS One ; 19(6): e0292474, 2024.
Article in English | MEDLINE | ID: mdl-38923956

ABSTRACT

The effects of turbidity and sedimentation stress on early life stages of corals are poorly understood, particularly in Atlantic species. Dredging operations, beach nourishment, and other coastal construction activities can increase sedimentation and turbidity in nearby coral reef habitats and have the potential to negatively affect coral larval development and metamorphosis, reducing sexual reproduction success. In this study, we investigated the performance of larvae of the threatened Caribbean coral species Orbicella faveolata exposed to suspended sediments collected from a reef site in southeast Florida recently impacted by dredging (Port of Miami), and compared it to the performance of larvae exposed to sediments collected from the offshore, natal reef of the parent colonies. In a laboratory experiment, we tested whether low and high doses of each of these sediment types affected the survival, settlement, and respiration of coral larvae compared to a no-sediment control treatment. In addition, we analyzed the sediments used in the experiments with 16S rRNA gene amplicon sequencing to assess differences in the microbial communities present in the Port versus Reef sediments, and their potential impact on coral performance. Overall, only O. faveolata larvae exposed to the high-dose Port sediment treatment had significantly lower survival rates compared to the control treatment, suggesting an initial tolerance to elevated suspended sediments. However, significantly lower settlement rates were observed in both Port treatments (low- and high-dose) compared to the control treatment one week after exposure, suggesting strong latent effects. Sediments collected near the Port also contained different microbial communities than Reef sediments, and higher relative abundances of the bacteria Desulfobacterales, which has been associated with coral disease. We hypothesize that differences in microbial communities between the two sediments may be a contributing factor in explaining the observed differences in larval performance. Together, these results suggest that the settlement success and survival of O. faveolata larvae are more readily compromised by encountering port inlet sediments compared to reef sediments, with potentially important consequences for the recruitment success of this species in affected areas.


Subject(s)
Anthozoa , Coral Reefs , Geologic Sediments , Larva , Animals , Anthozoa/growth & development , Anthozoa/microbiology , Anthozoa/physiology , Larva/growth & development , Geologic Sediments/microbiology , Endangered Species , RNA, Ribosomal, 16S/genetics , Florida , Microbiota
20.
J Org Chem ; 78(2): 647-57, 2013 Jan 18.
Article in English | MEDLINE | ID: mdl-23256861

ABSTRACT

The reaction of o-sulfinylbenzyl carbanions with prochiral Michael acceptors, such as differently sized cycloalkenones, proceeded with high levels of stereoselectivity, generating molecules containing up to three asymmetric carbon centers in just one synthetic step. All these reactions involved the use of either a proton or an acylating reagent as the final electrophile. Furthermore, the trapping of the enolate resulting from Michael addition with prochiral electrophiles, such as aldehydes or N-sulfonylimines, allowed the highly stereoselective synthesis of densely functionalized compounds containing four chiral centers in just a one-pot sequence, the stereochemical outcome of the sequence being controlled by the sulfinyl auxiliary.


Subject(s)
Aldehydes/chemistry , Benzyl Compounds/chemistry , Carbon/chemistry , Lithium Compounds/chemistry , Sulfhydryl Compounds/chemistry , Catalysis , Molecular Structure , Stereoisomerism
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