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Tuberculosis (TB) is the leading cause of death among infectious diseases worldwide. Among the estimated cases of drug-resistant TB, approximately 60% occur in the BRICS countries (Brazil, Russia, India, China and South Africa). Among Brazilian states, primary and acquired multidrug-resistant TB (MDR-TB) rates were the highest in Rio Grande do Sul (RS). This study aimed to perform molecular characterisation of MDR-TB in the State of RS, a high-burden Brazilian state. We performed molecular characterisation of MDR-TB cases in RS, defined by drug susceptibility testing, using 131 Mycobacterium tuberculosis (M.tb) DNA samples from the Central Laboratory. We carried out MIRU-VNTR 24loci, spoligotyping, sequencing of the katG, inhA and rpoB genes and RDRio sublineage identification. The most frequent families found were LAM (65.6%) and Haarlem (22.1%). RDRio deletion was observed in 42 (32%) of the M.tb isolates. Among MDR-TB cases, eight (6.1%) did not present mutations in the studied genes. In 116 (88.5%) M.tb isolates, we found mutations associated with rifampicin (RIF) resistance in rpoB gene, and in 112 isolates (85.5%), we observed mutations related to isoniazid resistance in katG and inhA genes. An insertion of 12 nucleotides (CCAGAACAACCC) at the 516 codon in the rpoB gene, possibly responsible for a decreased interaction of RIF and RNA polymerase, was found in 19/131 of the isolates, belonging mostly to LAM and Haarlem families. These results enable a better understanding of the dynamics of transmission and evolution of MDR-TB in the region.
Gluten is only partially digested by intestinal enzymes and can generate peptides that can alter intestinal permeability, facilitating bacterial translocation, thus affecting the immune system. Few studies addressed the role of diet with gluten in the development of colitis. Therefore, we investigate the effects of wheat gluten-containing diet on the evolution of sodium dextran sulphate (DSS)-induced colitis. Mice were fed a standard diet without (colitis group) or with 4·5 % wheat gluten (colitis + gluten) for 15 d and received DSS solution (1·5 %, w/v) instead of water during the last 7 d. Compared with the colitis group, colitis + gluten mice presented a worse clinical score, a larger extension of colonic injury area, and increased mucosal inflammation. Both intestinal permeability and bacterial translocation were increased, propitiating bacteria migration for peripheral organs. The mechanism by which diet with gluten exacerbates colitis appears to be related to changes in protein production and organisation in adhesion junctions and desmosomes. The protein α-E-catenin was especially reduced in mice fed gluten, which compromised the localisation of E-cadherin and β-catenin proteins, weakening the structure of desmosomes. The epithelial damage caused by gluten included shortening of microvilli, a high number of digestive vacuoles, and changes in the endosome/lysosome system. In conclusion, our results show that wheat gluten-containing diet exacerbates the mucosal damage caused by colitis, reducing intestinal barrier function and increasing bacterial translocation. These effects are related to the induction of weakness and disorganisation of adhesion junctions and desmosomes as well as shortening of microvilli and modification of the endocytic vesicle route.
Diarrhoeagenic Escherichia coli (DEC) is a leading cause of infectious diarrhoea worldwide. In recent years, Escherichia albertii has also been implicated as a cause of human enteric diseases. This study describes the occurrence of E. coli pathotypes and serotypes associated with enteric illness and haemolytic uremic syndrome (HUS) isolated in Brazil from 2011 to 2016. Pathotypes isolated included enteropathogenic E. coli (EPEC), enteroaggregative E. coli (EAEC), enterotoxigenic E. coli (ETEC), enteroinvasive E. coli (EIEC) and Shiga toxin-producing E. coli (STEC). PCR of stool enrichments for DEC pathotypes was employed, and E. albertii was also sought. O:H serotyping was performed on all DEC isolates. A total of 683 DEC and 10 E. albertii strains were isolated from 5047 clinical samples. The frequencies of DEC pathotypes were 52.6% (359/683) for EPEC, 32.5% for EAEC, 6.3% for ETEC, 4.4% for EIEC and 4.2% for STEC. DEC strains occurred in patients from 3 months to 96 years old, but EPEC, EAEC and STEC were most prevalent among children. Both typical and atypical isolates of EPEC and EAEC were recovered and presented great serotype heterogeneity. HUS cases were only associated with STEC serotype O157:H7. Two E. albertii isolates belonged to serogroup O113 and one had the stx2f gene. The higher prevalence of atypical EPEC in relation to EAEC in community-acquired diarrhoea in Brazil suggests a shift in the trend of DEC pathotypes circulation as previously EAEC predominated. This is the first report of E. albertii isolation from active surveillance. These results highlight the need of continuing DEC and E. albertii surveillance, as a mean to detect changes in the pattern of pathotypes and serotypes circulation and provide useful information for intervention and control strategies.
Phosphorus and calcium deficiency in horses represents an important factor responsible for the low equine production in Brazil. The basic mechanisms of P and Ca metabolism differ substantially among species. Regulation of P and Ca metabolism is less well understood in horses than in others species. With the use of the isotopic dilution technique is possible to evaluate the metabolism for this mineral. The aim of the present experiment was to study the effect of different Ca levels in the diet on P and Ca metabolism in horses.
In vitro and in situ techniques for research on ruminants are currently much in focus. Since they have good correlations with in vivo data, they are feasible alternatives to predict the nutrition rates of feeds and may be applied in equine research on in vivo apparent digestibility. On the other hand, the disadvantage of these methods is due to the fact that fistulated animals are required to obtain the inoculum. Theodorou et al., (1994) developed an extremely promising gas production technique to assess feeds for ruminants, but still require rumen inoculum obtained from operated animals. Faecal microorganisms function similarly to those in the rumen and in the large intestine of equines. The objective this experiment was to compare rumen liquor and equine faeces as inoculum to determine in vitro digestibility of equine feeds.
Concentrate mixtures fed ruminants generally are composed by cereals where phosphorus is present mainly in phytate form or phytin (Maga, 1982). Phytate phosphorus is thought to be completely available to ruminants due to the presence of phytase enzyme that hydrolyzes phytate phosphorus making it available for absorption. Researches have shown that this fact is not always true, depending on different conditions (Park et al., 2000). The aim of this paper was to study the influence of phytate phosphorus on calcium availability.
In Northeast of Portugal sheep is reared under extensive systems. These systems frequently involve expressive body composition changes due to the storing and mobilization of body reserves, mainly fat. Body condition score (BCS) is the most common way to assess these reserves and the nutritional status of ewes. However due to the subjective nature of BCS, their quality has been questioned and other alternatives has been studied. For cattle there are some studies that use the real time ultrasonography (RTU) to evaluate the BCS (Schwager-Suter et al., 2000; Broring et al., 2003), but this approach was not tested in ewes. Therefore the aim of the present study was to establish a relationship between the BCS and ultrasound subcutaneous fat (SF) and Longissimus thoracis et lumborum muscle (LM) measurements.
With the use of radioactive calcium (Ca) it is possible to study the kinetic aspects of Ca metabolism. Research in Brazil has been carried out to study mineral metabolism in sheep and cattle, especially phosphorus, by using isotope dilution techniques. However, there is very little information on Ca metabolism in sheep. The objective of this experiment was to study the effects of various Ca sources on the Ca metabolism in sheep by using isotope and balance techniques.
The close association of calcium and phosphorus in bone, and the narrow relationship between these minerals makes this subject always an important aim of study for researches on animal nutrition (Braithwaite, 1984). The utilization of alternative sources of calcium has been studied in Brazil in the last years however there is a lack of information about the effects of these sources on phosphorus metabolism. The aim of this study was to evaluate phosphorus metabolism in sheep fed four different sources of calcium through determination of true absorption and endogenous faecal loss of phosphorus by using the isotope dilution technique (Vitti et al., 2000).
The aim of this study was to evaluate the effect of dietary lysine on performance, protein deposition and respiratory chain gene expression in male broilers. A total of 252 Cobb 500 broilers were distributed, in a completely randomized design, into four treatments with seven replicates of nine birds per experimental unit. Experimental treatments consisted of diets based on corn and soybean meal, with four levels of digestible lysine: 1.016%, 1.099%, 1.182% and 1.265%. The increase in the level of digestible lysine in the diet provided higher weight gains, feed efficiency and body protein deposition. Birds fed the lowest level of dietary lysine (1.016%) showed a lower expression of genes such as NADH dehydrogenase subunit I (ND1), cytochrome b (CYTB) and cytochrome c oxidase subunits I (COX I), II (COX II) and III (COX III), displaying the worst performance and body protein deposition. This demonstrates the relationship existing between the expression of the evaluated genes and the performance responses. In conclusion, results indicate that broilers fed diets with higher levels of digestible lysine have increased messenger RNA expression of some genes coded in the mitochondrial electron transport chain (ND1, CYTB, COX I, COX II and COX III). It may be stated that diets with proper levels of digestible lysine, within the ‘ideal protein’ concept, promote the expression of genes, which increases the mitochondrial energy, thereby fostering body protein deposition and the performance of broilers in the starter phase.
The dune of Oitavos, the underlying paleosol, and Helix sp. gastropod shells found within the paleosol were dated using a combination of radiocarbon and blue optically stimulated luminescence (OSL). The organic component of the paleosol produced a significantly older age (∼20,000 cal BP) than the OSL age measurement (∼15,000 yr), while 14C age measurements on the inorganic component and the gastropods produced ages of ∼35,000 yr and ∼34,000 yr, respectively. Rare-earth element analyses provide evidence that the gastropods incorporate geological carbonate, making them an unreliable indicator of the age of the paleosol. We propose that the 14C age of the small organic component of the paleosol is also likely to be unreliable due to incorporation of residual material. The OSL age measurement of the upper paleosol (∼15,000 yr) is consistent with the age for the base of the dune (∼14,500 yr). The younger OSL age for the top of the dune (∼12,000 yr) suggests that it was built up by at least 2 sand pulses or that there was a remobilization of material at the top during its evolution, prior to consolidation.
During radiation therapy, unwanted scatter to healthy tissues outside the target field may occur. Children and adolescents are more sensitive to radiation injury, and the thyroid gland is particularly susceptible to these effects.
To assess acute changes in thyroid function and volume in children and adolescents undergoing radiotherapy for a variety of non-thyroid cancers.
Materials and Methods
Thirty-one children and adolescents underwent radiation therapy of various body areas in which the thyroid was not included. Thyroid-stimulating hormone (TSH), thyroxine (T4), free thyroxine (fT4), triiodothyronine (T3), anti-thyroperoxidase antibodies and thyroglobulin were measured before, on the last day and at 1 and 3 months after the end of radiotherapy. Ultrasound scans were taken and 6- and 24-hour 131I uptake was measured before and after treatment. The scattered dose to the thyroid region was estimated with a treatment planning system or measured with thermoluminescent dosimeters.
The median radiation dose scattered to the thyroid was 296·6 cGy (IQR 16·7–1,709·0). Levels of TSH (p = 0·575), T4 (p = 0·950), fT4 (p = 0·510), T3 (p = 0·842), thyroglobulin (p = 0·620) and anti-thyroid peroxidase antibodies (p = 0·546) were statistically similar at all four time points. There were no differences between pre- and post-radiotherapy thyroid volume and 131I uptake (p = 0·692 and 0·92, respectively).
More sensitive methods may be required to ascertain whether acute injury to the follicular epithelium occurs with lower radiation doses scattered to the thyroid.
The objective of the current study was to evaluate the utilization of calcium (Ca) and phosphorus (P) in growing sheep consuming increasing amounts of dicalcium phosphate. Eighteen growing sheep, aged 8 months, were fed a basal diet supplemented with 0, 12·5 and 25 g of dicalcium phosphate/day. During the experiment, animals were injected intravenously with 7·4 MBq of 45Ca and 32P and samples of plasma, faeces and urine were subsequently taken daily for 1 week after injection. Rumen fluid was sampled on days 4–7 after injection. Specific radioactivity in plasma and in faeces were used to determine true absorption of Ca and P, whereas plasmatic and ruminal specific radio-activities were used to determine endogenous P flow into the rumen and turnover time of rumen P. Increasing dicalcium phosphate intake led to linear increases in faecal excretion of endogenous Ca and P (P<0·05), suggesting that surpluses of ingested Ca and P were voided through secretion to the gut. True absorption coefficients for 0, 12·5 and 25 g of dicalcium phosphate ingested daily were 0·54, 0·41 and 0·38 for Ca, and 0·66, 0·62 and 0·64 for P, respectively. Flows of endogenous P into the rumen increased linearly and ruminal turnover time of P decreased linearly (P<0·01) as P intake was increased. Concentrations of Ca and P in bone were not affected by the increased amounts of these minerals ingested (P<0·05). In conclusion, increasing ingestion of dicalcium phosphate increases faecal excretion of Ca and P, thus decreasing the efficiency of utilization of both minerals. Moreover, increasing levels of dietary P increased endogenous P excretion, contributing to the amount of P disposed of in the environment.
The ability to control the deposition of mouse embryonic stem cells (mESCs),
and mESCs encapsulated in 200-μm diameter alginate microbeads, into
customized patterns has recently been achieved using laser direct-write
(LDW). Gelatin-based LDW was utilized to target and reproducibly deposit
groups of cells directly onto receiving substrate surfaces. Live/dead
staining for cell viability and immunocytochemistry for the pluripotency
marker, Oct-4, indicated that transferred mESCs were viable following
transfer, and maintained an important embryonic stem cell marker,
respectively. LDW was further used to print mESCs encapsulated in hydrogel
microbeads into customized patterns on a single-bead basis. Recent efforts
have also achieved patterns of discrete co-cultures of mESCs and breast
cancer cells in separate hydrogel microbeads. Altogether, we demonstrated
the feasibility of LDW to print patterns of mESCs and mESC-microbeads for
the biomimetic assembly of engineered cellular constructs and tissue
Octafunctionalized silsesquioxanes [(RsiO1.5)8, cubes] offer potential as rigid, hard nanoplatforms to which a variety of organofunctional groups can be appended. Crosslinking these groups leads to novel organic/inorganic nanocomposites that consist primarily of interfacial interactions. These materials can be 100% interphase. We present efforts to develop nanocomposite materials that consist of both continuous and discontinuous organic/inorganic phases. We then discuss methods of probing the properties of these materials.
Chagas' disease is a debilitating but comparatively neglected illness that affects about 15 million people. There is an urgent need to develop new, more effective, and less-toxic compounds. In this study, we assessed the in vitro anti-trypanosomal activity of the sesquiterpene elatol from the Brazilian red seaweed Laurencia dendroidea. We used electron microscopy to evaluate the effect of elatol on the morphology and ultrastructure of the parasite. Elatol showed a dose-dependent effect against the epimastigote, trypomastigote, and amastigote forms, with IC50 values of 45·4, 1·38, and 1·01 μm, respectively. Observation of treated intracellular amastigotes by light microscopy demonstrated a total elimination of the infection at a dose of 3·0 μm. In addition, the compound did not affect the red blood cells, and the CC50 value for LLCMK2 cells was 27·0 μm. Transmission and scanning electron micrographs showed aberrant-shaped cells and breaks in the plasma membrane, prominent swollen mitochondria, and extensive formation of cytoplasmic vacuoles in all the forms. This is the first report of the anti-trypanosomal effect of the sesquiterpene elatol.
The objective of the current study was to apply the Vitti–Dias model to investigate phosphorus (P) metabolism in growing pigs fed a diet supplemented with microbial phytase. The basal diet contained maize, defatted rice bran, vegetable oil, soybean meal, limestone, salt and a vitamin and mineral mix. There was no inorganic P in the diet and phytase was added at levels of 253, 759, 1265 and 1748 phytase units (PU)/kg of feed. The compartmental model included four pools of P: (1) gut lumen, (2) plasma, (3) bone and (4) soft tissue. A single dose of 32P was administered, and specific radioactivity was measured in plasma, faeces, bone and soft tissue (muscle, heart, liver and kidney) at different times post-dosing for calculation of P flows between pools. Total P absorbed showed a negative relationship with total P excreted in faeces and was strongly correlated with bone P retention, suggesting that absorbed P was channelled to bone to address its physiological growth. Average efficiency of metabolic utilization of absorbed P was estimated to be 0·94, with 0·52 g/g of total net P balance being accreted in bone and the rest in soft tissue (including muscle and some vital organs). The Vitti–Dias model provided suitable representation of P interchange between compartments (in particular, flows between gut and plasma and partitioning of available P between bone and soft tissue), resulting in estimates of P flows comparable with values calculated from balance data.
We consider the two-dimensional version of a drainage network model introduced in Gangopadhyay, Roy and Sarkar (2004), and show that the appropriately rescaled family of its paths converges in distribution to the Brownian web. We do so by verifying the convergence criteria proposed in Fontes, Isopi, Newman and Ravishankar (2002).
Inflammation is a stereotypical physiological response to infections and tissue injury; it initiates pathogen killing as well as tissue repair processes and helps to restore homeostasis at infected or damaged sites. Acute inflammatory reactions are usually self-limiting and resolve rapidly, due to the involvement of negative feedback mechanisms. Thus, regulated inflammatory responses are essential to remain healthy and maintain homeostasis. However, inflammatory responses that fail to regulate themselves can become chronic and contribute to the perpetuation and progression of disease. Characteristics typical of chronic inflammatory responses underlying the pathophysiology of several disorders include loss of barrier function, responsiveness to a normally benign stimulus, infiltration of inflammatory cells into compartments where they are not normally found in such high numbers, and overproduction of oxidants, cytokines, chemokines, eicosanoids and matrix metalloproteinases. The levels of these mediators amplify the inflammatory response, are destructive and contribute to the clinical symptoms. Various dietary components including long chain ω-3 fatty acids, antioxidant vitamins, plant flavonoids, prebiotics and probiotics have the potential to modulate predisposition to chronic inflammatory conditions and may have a role in their therapy. These components act through a variety of mechanisms including decreasing inflammatory mediator production through effects on cell signaling and gene expression (ω-3 fatty acids, vitamin E, plant flavonoids), reducing the production of damaging oxidants (vitamin E and other antioxidants), and promoting gut barrier function and anti-inflammatory responses (prebiotics and probiotics). However, in general really strong evidence of benefit to human health through anti-inflammatory actions is lacking for most of these dietary components. Thus, further studies addressing efficacy in humans linked to studies providing greater understanding of the mechanisms of action involved are required.