1,489 research outputs found
Charmonium Absorption in the Meson-exchange Model
We review the meson-exchange model for charmonium absorption by hadrons. This
includes the construction of the interaction Lagrangians, the determination of
the coupling constants, the introduction of form factors, and the predicted
cross sections for absorption by both mesons and nucleons. We further
discuss the effects due to anomalous parity interactions, uncertainties in form
factors, constraints from chiral symmetry, and the change of charmed meson mass
in medium on the cross sections for charmonium absorption in hadronic matter.Comment: 10 pages, 2 figures. Talk given at Quark Matter 2002 (QM 2002),
Nantes, France, 18-24 July 2002. To appear in the proceedings (Nucl. Phys. A
Classic and spatial shift-share analysis of state-level employment change in Brazil
This paper combines classic and spatial shift-share decompositions of 1981 to 2006 employment change across the 27 states of Brazil. The classic shift-share method shows higher employment growth rates for underdeveloped regions that are due to an advantageous industry-mix and also due to additional job creation, commonly referred to as the competitive effect. Alternative decompositions proposed in the literature do not change this broad conclusion. Further examination employing exploratory spatial data analysis (ESDA) shows spatial correlation of both the industry-mix and the competitive effects. Considering that until the 1960s economic activities were more concentrated in southern regions of Brazil than they are nowadays, these results support beta convergence theories but also find evidence of agglomeration effects. Additionally, a very simple spatial decomposition is proposed that accounts for the spatially-weighted growth of surrounding states. Favourable growth in northern and centre-western states is basically associated with those states’ strengths in potential spatial spillover effect and in spatial competitive effect
Chronic inflammatory polyneuropathy associated with ulcerative colitis: a reported case in literature
AbstractBackground: Peripheral neuropathy is known to be related to inflammatory bowel disease and it is one of the most frequently reported neurologic complications. Various studies have found peripheral nervous system complications, rather than central nervous system involvement, to be predominant. In the literature, there are a few cases of inflammatory polyneuropathy developed in the course of ulcerative colitis : 5 cases of Guillain-Barré syndrome, one case of chronic inflammatory demyelinating polyneuropathy, 10 cases of neuropathy and one case of perineuritis. Case presentation: We describe a case of chronic inflammatory polyneuropathy associated with ulcerative colitis. Conclusion: Peripheral neuropathy is not a common manifestation of IBD, highlighting the need for careful exclusion of other causes of neuropathy when both conditions are encountered in clinical practice. Â
Expression of PROKR1 and PROKR2 in Human Enteric Neural Precursor Cells and Identification of Sequence Variants Suggest a Role in HSCR
Background
The enteric nervous system (ENS) is entirely derived from neural crest and its normal development is regulated by specific molecular pathways. Failure in complete ENS formation results in aganglionic gut conditions such as Hirschsprung's disease (HSCR). Recently, PROKR1 expression has been demonstrated in mouse enteric neural crest derived cells and Prok-1 was shown to work coordinately with GDNF in the development of the ENS.
Principal Findings
In the present report, ENS progenitors were isolated and characterized from the ganglionic gut from children diagnosed with and without HSCR, and the expression of prokineticin receptors was examined. Immunocytochemical analysis of neurosphere-forming cells demonstrated that both PROKR1 and PROKR2 were present in human enteric neural crest cells. In addition, we also performed a mutational analysis of PROKR1, PROKR2, PROK1 and PROK2 genes in a cohort of HSCR patients, evaluating them for the first time as susceptibility genes for the disease. Several missense variants were detected, most of them affecting highly conserved amino acid residues of the protein and located in functional domains of both receptors, which suggests a possible deleterious effect in their biological function.
Conclusions
Our results suggest that not only PROKR1, but also PROKR2 might mediate a complementary signalling to the RET/GFRα1/GDNF pathway supporting proliferation/survival and differentiation of precursor cells during ENS development. These findings, together with the detection of sequence variants in PROKR1, PROK1 and PROKR2 genes associated to HSCR and, in some cases in combination with RET or GDNF mutations, provide the first evidence to consider them as susceptibility genes for HSCR.This work was supported by Fondo de Investigación Sanitaria, Spain (PI070080, PI1001290 and PI071315 for the E-Rare project), Consejería de Innovación Ciencia y Empresa de la Junta de Andalucía (CTS 2590) and Consejería de Salud de la Junta de Andalucía (PI0249-2008). The CIBER de Enfermedades Raras is an initiative of the ISCIII. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.Peer reviewe
Acute and sub chronic toxicity study of aqueous extract from the leaves and branches of Campomanesia velutina (Cambess) O. Berg.
Ethnopharmacological relevance: Campomanesia velutina leaves and branches infusions are used in Brazilian
folk medicine to treat diarrhea and to ameliorate intestinal cramps, respectively.
Aim of the study: Carry out the acute and sub chronic pre-clinical evaluation and thus assess the safety and
toxicological potential of the specie.
Materials and methods: In vivo toxicity was evaluated by acute and sub chronic toxicity assays conducted
according to the guidelines of the Brazilian Agency of National Health Surveillance (Ag?ncia Nacional de
Vigil?ncia Sanit?ria ? ANVISA). For acute toxicity evaluation, a single dose of aqueous extracts from the leaves
(AEL) and branches (AEB) of Campomanesia velutina were orally administered to mice at doses of 300, 600
and 1200 mg/kg. Then, the animals were observed for 14 days. In the sub chronic study, the extracts were orally
administered to mice for 14 days at doses of 300, 600 and 1200 mg/kg. To assess the toxicological effects,
animals were closely observed on general behavior, clinical signs of toxicity, body weight, food and water intake.
At the end of the experiment, it was performed biochemical and hematological evaluations, as well as
histopathological analysis from the following organs: brain, heart, lungs, liver, stomach, small intestine (section)
and left kidney. Preliminary phytochemical analysis was performed using thin layer chromatography (TLC) and
colorimetric pharmacognostic tests.
Results: In oral acute assay, treatment with AEB at the major dose (1200 mg/kg) caused diarrhea, abdominal
cramps and tremors in females. These effects were reversed at 4th hour. Normochromic normocytic anemia was
observed in males treated with AEL 300 mg/kg and AEB 600 and 1200 mg/kg as well as in females treated with
AEB 300 and 1200 mg/kg. The kidney of all treated animals showed moderate inflammation and a few hemorrhagic
points. In sub chronic assay, treatment with AEL 600 mg/kg, AEL 1200 mg/kg and AEB 1200 mg/kg caused hyper
excitability in females that was not reversed. Treatments also had impact on weight gain and the relative weight of
males? brain was increased on group treated with AEL 300 mg/kg, AEB 300 and AEB 1200 mg/kg. Although
changes in hematological parameters were not observed, serum creatinine levels were significantly higher in males
treated with AEB 300 mg/kg. Besides, the heart of all treated animals showed intense hyperemia. Preliminary
phytochemical analysis revealed the presence of flavonoids, tannins and phenolic compounds.
Conclusions: Toxicity signs were mainly observed after treatment with AEL and AEB at the two highest tested
doses (600 and 1200 mg/kg), suggesting that the extracts are relatively safe at its effective dose (300 mg/kg).
However, alterations on hematological and biochemical parameters and on the kidney and heart of the animals
were not closely related with the dose, implying caution on its use
NOX1-dependent redox signaling potentiates colonic stem cell proliferation to adapt to the intestinal microbiota by linking EGFR and TLR activation
The colon epithelium is a primary point of interaction with the microbiome and is regenerated by a few rapidly cycling colonic stem cells (CSCs). CSC self-renewal and proliferation are regulated by growth factors and the presence of bacteria. However, the molecular link connecting the diverse inputs that maintain CSC homeostasis remains largely unknown. We report that CSC proliferation is mediated by redox-dependent activation of epidermal growth factor receptor (EGFR) signaling via NADPH oxidase 1 (NOX1). NOX1 expression is CSC specific and is restricted to proliferative CSCs. In the absence of NOX1, CSCs fail to generate ROS and have a reduced proliferation rate. NOX1 expression is regulated by Toll-like receptor activation in response to the microbiota and serves to link CSC proliferation with the presence of bacterial components in the crypt. The TLR-NOX1-EGFR axis is therefore a critical redox signaling node in CSCs facilitating the quiescent-proliferation transition and responds to the microbiome to maintain colon homeostasis
Genetic Characterization of Human T-Cell Lymphotropic Virus Type 1 in Mozambique: Transcontinental Lineages Drive the HTLV-1 Endemic
Human T-cell lymphotropic virus type 1 (HTLV-1) is the causative agent of Adult T-Cell Leukemia/Lymphoma (ATL), the Tropical Spastic Paraparesis/HTLV-1-associated Myelopathy (TSP/HAM) and other inflammatory diseases, including dermatitis, uveitis, and myositis. It is estimated that 2–8% of the infected persons will develop a HTLV-1-associated disease during their lifetimes, frequently TSP/HAM. Thus far, there is not a specific treatment to this progressive and chronic disease. HTLV-1 has means of three transmission: (i) from mother to child during prolonged breastfeeding, (ii) between sexual partners and (iii) through blood transfusion. HTLV-1 has been characterized in 7 subtypes and the geographical distribution and the clinical impact of this infection is not well known, mainly in African population. HTLV-1 is endemic in sub-Saharan Africa. Mozambique is a country of southeastern Africa where TSP/HAM cases were reported. Recently, our group estimated the HTLV prevalence among Mozambican blood donors as 0.9%. In this work we performed a genetic analysis of HTLV-1 in blood donors and HIV/HTLV co-infected patients from Maputo, Mozambique. Our results showed the presence of three HTLV-1 clusters within the Cosmopolitan/Transcontinental subtype/subgroup. The differential rates of HIV-1/HTLV-1 co-infection in the three HTLV-1 clusters demonstrated the dynamic of the two viruses and the need for implementation of control measures focusing on both retroviruses
Dietary inflammatory index and inflammatory biomarkers in adolescents from LabMed physical activity study
Background/objectives The dietary inflammatory index (DII) is a tool to measure the diet’s inflammatory potential and has
been used with adults to predict low-grade inflammation. The present study aims to assess whether this dietary score predicts
low-grade inflammation in adolescents.
Subjects/methods The sample comprises 329 adolescents (55.9% girls), aged 12–18 years, from LabMed Physical Activity
Study. DII score was calculated based on a food-frequency questionnaire and categorized into tertiles. We collected blood
samples to determine the follow inflammatory biomarkers: C-reactive protein (CRP), interleukin-6 (IL-6), complement
component 3 (C3), and 4 (C4). In addition we calculated an overall inflammatory biomarker score. Odds ratios (OR) and
95% confidence intervals (95%CI) were computed from binary logistic regression models.
Results DII score, comparing first with third tertile, was positively associated with IL-6 in crude model (OR = 1.88, 95%
CI:1.09–3.24, ptrend = 0.011) and in fully adjusted (for biological and lifestyle variables) (OR = 3.38, 95%CI:1.24–9.20,
ptrend = 0.023). Also, DII score was positively associated with C4, when fully adjusted (OR = 3.12, 95%CI:1.21–8.10, ptrend
= 0.016). DII score was negatively associated with C3 in crude model, comparing first with second but not with third tertile,
and no significant associations in fully adjusted model were observed, although a trend was found (OR = 1.71, 95%
CI:0.63–4.66, ptrend = 0.044). No significant associations were observed between DII score and CRP. However, DII score
was positively associated with the overall inflammatory biomarker score, when fully adjusted (OR = 5.61, 95%
CI:2.00–15.78, ptrend = 0.002).
Conclusions DII score can be useful to assess the diet’s inflammatory potential and its association with low-grade inflammation in adolescents.The authors gratefully acknowledged the participation
of all adolescents and their parents, teachers and schools of
the LabMed and Physical Activity Study, the cooperation of volunteer’s,
the Department of Hygiene and Epidemiology (University of
Porto) for the conversion food frequency questionnaire data into
nutrients, and the Research Centre in Physical Activity, Health and
Leisure (University of Porto) for the sponsoring the LabMed and
Physical Activity Study.info:eu-repo/semantics/publishedVersio
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