Hours Of Digestion Research Articles

Exploring the impact of digestive physicochemical parameters of adults and infants on the pathophysiology of Cryptosporidium parvum using the dynamic TIM-1 gastrointestinal model

BackgroundHuman cryptosporidiosis is distributed worldwide, and it is recognised as a leading cause of acute diarrhoea and death in infants in low- and middle-income countries. Besides immune status, the higher incidence and severity of this gastrointestinal disease in young children could also be attributed to the digestive environment. For instance, human gastrointestinal physiology undergoes significant changes with age, however the role this variability plays in Cryptosporidium parvum pathogenesis is not known. In this study, we analysed for the first time the impact of digestive physicochemical parameters on C. parvum infection in a human and age-dependent context using a dynamic in vitro gastrointestinal model.ResultsOur results showed that the parasite excystation, releasing sporozoites from oocysts, occurs in the duodenum compartment after one hour of digestion in both child (from 6 months to 2 years) and adult experimental conditions. In the child small intestine, slightly less sporozoites were released from excystation compared to adult, however they exhibited a higher luciferase activity, suggesting a better physiological state. Sporozoites collected from the child jejunum compartment also showed a higher ability to invade human intestinal epithelial cells compared to the adult condition. Global analysis of the parasite transcriptome through RNA-sequencing demonstrated a more pronounced modulation in ileal effluents compared to gastric ones, albeit showing less susceptibility to age-related digestive condition. Further analysis of gene expression and enriched pathways showed that oocysts are highly active in protein synthesis in the stomach compartment, whereas sporozoites released in the ileum showed downregulation of glycolysis as well as strong modulation of genes potentially related to gliding motility and secreted effectors.ConclusionsDigestion in a sophisticated in vitro gastrointestinal model revealed that invasive sporozoite stages are released in the small intestine, and are highly abundant and active in the ileum compartment, supporting reported C. parvum tissue tropism. Our comparative analysis suggests that physicochemical parameters encountered in the child digestive environment can influence the amount, physiological state and possibly invasiveness of sporozoites released in the small intestine, thus potentially contributing to the higher susceptibility of young individuals to cryptosporidiosis.

In vitro simulated study of macronutrient digestion in complex food using digestive enzyme supplement

Digestive enzymes secreted by the body are vital for digestion and nutrient absorption. Enzyme supplements are commonly used to support them in achieving optimal digestion. Herein, the efficacy of digestive enzyme supplement (DigeSEB Super) in digestion of complex food was assessed using INFOGEST simulated static and modified semi-dynamic in vitro digestion models. Digestive enzyme supplement was found to assist the endogenous digestive enzymes to disintegrate the food matrix. Hence, it reduced the viscosity of the gastric digesta by 2.75 fold (p = 0.04) compared to the control digestion (only endogenous digestive enzymes) during the first hour of digestion. Similarly, enzyme supplement showed statistically higher release of reducing sugars in the gastric digestion (p ≤ 0.05) indicating improved digestion of carbohydrates. Further, digestion of proteins and fats was also improved in the presence of enzyme supplement. The kinetic aspects of the semi-dynamic model (transient nature of gastric secretions and gradual acidification) was found to alter the macronutrient digestion compared to the static digestion. Thus, semi-dynamic model should be preferred for the in vitro studies. Overall, current study demonstrated the potential of a digestive enzyme supplement to improve digestion by aiding digestive action of the endogenous enzymes.

Developing an in vitro lipolysis model for real-time analysis of drug concentrations during digestion of lipid-based formulations

Understanding the effect of digestion on oral lipid-based drug formulations is a critical step in assessing the impact of the digestive process in the intestine on intraluminal drug concentrations. The classical pH-stat in vitro lipolysis technique has traditionally been applied, however, there is a need to explore the establishment of higher throughput small-scale methods. This study explores the use of alternative lipases with the aim of selecting digestion conditions that permit in-line UV detection for the determination of real-time drug concentrations. A range of immobilised and pre-dissolved lipases were assessed for digestion of lipid-based formulations and compared to digestion with the classical source of lipase, porcine pancreatin. Palatase® 20000 L, a purified liquid lipase, displayed comparable digestion kinetics to porcine pancreatin and drug concentration determined during digestion of a fenofibrate lipid-based formulation were similar between methods. In-line UV analysis using the MicroDISS ProfilerTM demonstrated that drug concentration could be monitored during one hour of dispersion and three hours of digestion for both a medium- and long-chain lipid-based formulations with corresponding results to that obtained from the classical lipolysis method. This method offers opportunities exploring the real-time dynamic drug concentration during dispersion and digestion of lipid-based formulations in a small-scale setup avoiding artifacts as a result of extensive sample preparation.

Biogas Production from Palm Oil Mill Effluent at Low pH

The palm oil industry in Malaysia has aided our economy, but with any thriving industry comes the baggage of industrial waste. This paper focuses on palm oil mill effluent (POME), a waste product formed by palm oil milling operations. The objective of this paper is to evaluate the ability of POME to generate biogas through acid and heat pre-treatment methods. The feasibility of producing biogas at pH levels lower than 5 was investigated. The inoculum is effective microbe 1 (EM1), and the substrate is a liquid POME. Hydrochloric and phosphoric acid were used in this study, and the effect of low initial pH on biogas generation was investigated. The results show that POME alone produced the highest biogas volume (20.1 Nml). However, POME incubated with activated EM1 inoculant at low pH (3.74) generated consistent biogas during 57.75 hours of digestion. In conclusion, the EM1 is a good source of inoculum for POME treatment at low pH, with no pre-treatment required. The pre-treatment methods proposed in this study could have opened new doors for bio-renewable energy research, particularly in agricultural biomass, since substrate pre-treatment can enhance biogas production.

Dynamic in vitro gastric digestion behaviour of camel milk

This study investigated the dynamic in vitro gastric digestion behaviour of camel milk. Coagulum that was retainable in the stomach was not formed during the digestion of camel milk, whereas bovine milk reconstituted to the same protein concentration (2.9%, w/w) underwent pronounced gastric coagulation into structured clots. During early digestion, the camel milk formed small particles, resulting from its weak coagulation, that were preferentially emptied from the stomach. These particles became more compact and spherical in the first hour of digestion and then gradually decreased in size. Protein analysis indicated that the main camel milk proteins were digested in the order αS1-casein > β-casein > α-lactalbumin, which may have been modulated by the decreasing pH during the dynamic gastric digestion. This unique coagulation behaviour of camel milk resulted in its rapid gastric digestion and emptying, which may have nutritional implications.

Encapsulation of DHA oil with heat-denatured whey protein in Pickering emulsion improves its bioaccessibility

This study compared the bioaccessibility of docosahexaenoic acid (DHA) provided encapsulated or unencapsulated within a food matrix. DHA oil was composed of DHA-enriched triacylglycerols prepared as Pickering emulsion by encapsulation with heat-denatured whey protein isolate particles and then incorporated into homogenized liquid egg to get omelets. The effect of encapsulation was analyzed by using a static in vitro digestion model of the adult, which digestive fluid enzymes have also been characterized by proteomics. First, the size of lipid droplets was shown to be smaller and uniformly dispersed in omelets with encapsulated-DHA oil compared to non-encapsulated-DHA oil. Distribution of droplets was more regular with encapsulated-DHA oil as well. As a consequence, we showed that encapsulating DHA oil promoted the hydrolysis by pancreatic lipase during the intestinal phase. A larger proportion of DHA enriched-triacylglycerols was hydrolyzed after two hours of digestion, leading to a greater release in free DHA. Thus, only 32% of DHA remained esterified in the triacylglycerols with encapsulated-DHA oil, compared to 43% with non-encapsulated-DHA oil. The DHA in free form ultimately represented 52% of the total DHA with encapsulated-DHA oil, compared to 40% with non-encapsulated-DHA oil. Finally, our results showed that as much DHA was released after one hour of intestinal digestion when the DHA oil was encapsulated as after two hours when the DHA oil was not encapsulated. Therefore, DHA bioaccessibility was significantly improved by encapsulation of DHA oil in omelets.

Исследование иммобилизации полифенолов овсяных отрубей в комплексные коацерваты сывороточного белка и мальтодекстрина

Introduction. Bioactive compounds are a very popular topic of modern food science, especially when it concerns obtaining polyphenols from cereals. The antiradical, antioxidant, and anti-inflammatory properties of these ingredients allow them to inhibit and prevent coronary, artery, and cardiovascular diseases, as well as several types of cancer. Encapsulation is an effective technology that protects bioactive ingredients during processing and storage. In addition, it also prevents any possible interaction with other food constituents. The research objective was to obtain effective tools of controlled delivery of bioactive compounds. The study featured whey protein as a wall material in combination with maltodextrin to encapsulate the bioactives from oat bran.
 Study objects and methods. The processed material was oat bran. The technology of its biotransformation was based on ultrasound processing and enzymatic hydrolysis. The antioxidant properties were determined using a coulometer of Expert – 006-antioxidants type (Econix-Expert LLC, Moscow, Russia). Separation and quantitative determination of extract were followed using a Stayer HPLC device (Akvilon, Russia) and a system column Phenomenex Luna 5u C18(2) (250×4.6 mm). The total phenolic content was measured by a modified Folin-Ciocalteu method. To prepare microcapsules, whey protein concentrate (WPC) and maltodextrin (MD) solutions were mixed at ratios 6:4, 4:6, and 5:5. After that, the mixes were treated by ultrasonication and 10% w/w of guar gum solution as double wall material. The encapsulation efficiency (EE) was determined as a ratio of encapsulated phenolic content to total phenolic content. A digestion protocol that simulates conditions of the human gastric and intestinal tract was adapted to investigate the release kinetics of the extracts.
 Results and discussion. Ferulic acid is the main antioxidant in cereals. Its amount during extraction was consistent with published data: 9.2 mg/mL after ultrasound exposure, 9.0 mg/mL after enzymatic extraction, and 8.6 mg/mL after chemical treatment. The antioxidant activity of the obtained polyphenols was quite high and reached 921 cu/mL. It depended on the concentration of the preparation in the solution and the extraction method. The polyphenols obtained by ultrasonic exposure and enzyme preparations proved to have a more pronounced antioxidant activity. The highest EE (95.28%) was recorded at WPC:MD ratio of 60:40. In vitro enzymatic hydrolysis protocol simulating digestion in the gastrointestinal tract was used to study the effect of capsule structural characteristics on the kinetics of polyphenol release. The percentage of o polyphenols released from capsules ranged from 70% to 83% after two hours of digestion, which confirmed the effectiveness of microencapsulation technology.
 Conclusion. The research confirmed the possibility of using polyphenols obtained by the biotechnological method from oat bran as functional ingredients. Eventually, they may be used in new functional products with bifidogenic properties. Whey protein can be used to encapsulate polyphenols as the wall material of microcapsules.

Physical, Mechanical, and Bioactive Properties of Pig Lung-Derived ECM Hydrogels are Dependent on the Duration of Pepsin Digestion

Extracellular matrix (ECM) hydrogels derived from decellularized lungs are promising materials for tissue engineering, in the development of clinical therapies, and for modeling the lung ECM in vitro. Characterizing and controlling the resulting physical, biochemical, mechanical, and biologic properties of decellularized ECM after enzymatic solubilization and gelation is thus of key interest. As the role of enzymatic pepsin digestion in effecting these properties has been understudied, we investigated the digestion time-dependency on key parameters of the resulting ECM hydrogel. Using resolubilized homogenized decellularized pig lung ECM (dECM) as a model system, significant time-dependent alterations in the protein concentration, turbidity, and gelation potential occurred between 4 and 24 hours of digestion, plateauing at longer digestion times. These results correlated with qualitative SEM images and quantitative analysis of hydrogel interconnectivity and average fiber diameter. Interestingly, the time-dependent changes in the storage modulus tracked with the hydrogel interconnectivity results, while the Young's modulus values were more closely related to average fiber size at each time point. The structural and biochemical alterations translated to significant changes in metabolic activity of several representative lung cells seeded onto the hydrogels with progressive decreases in cell viability and alterations in morphology observed in cells cultured on hydrogels produced with dECM digested for greater than 12 and up to 72 hours of digestion. These studies demonstrate that 12hr structured pepsin digest of pig lung dECM provides an optimal balance between desirable physical dECM hydrogel properties and effects on lung cell behaviors.

In vitro inhibitory effect of tea extracts on starch digestibility

AbstractThe effect of brown, oolong, and green teas’ extract on the in vitro inhibition of starch digestibility of cassava, corn, plantain, and yam was explored. The starches exhibited moderately low hydrolysis rate and had moderate resistant starch ratios. Tea metabolites after extraction at different temperatures were quantified and correlated to starch inhibition at 1% introduction using principal component analysis (PCA). Total polyphenols (TP), (−)‐epigallocatechin (EGC), (−)‐gallocatechin gallate (GCG), (−)‐catechin gallate (CG), and (−)‐epigallocatechin gallate (EGCG) were positively correlated with starch digestion inhibition especially in the first and second hours of digestion. The (+)‐catechin (C) and Total flavonoids (TF) in the teas, however, had a negative correlation with starch inhibition. Green tea extracts were more effective in starch digestion inhibition followed by brown tea and then oolong. TP, EGC, GCG, CG, and EGCG from green tea had the strongest inhibitory effect on starch digestion and that purified extracts of these compounds could be used at a statistically optimized combination to formulate diets with improved hypoglycemic potential.Practical applicationsIn order to identify key components in tea responsible for hypoglycemic effect, tea extracts from three different source and their starch inhibitory properties were analyzed using starches from four plant sources. To this end, key components in the tea varieties were identified with potential hypoglycemic effect. Therefore, diets with potential hypoglycemic effect could be formulated using purified extracts from tea such as TP, (−)‐epigallocatechin, (−)‐gallocatechin gallate, (−)‐catechin gallate, and (−)‐epigallocatechin gallate under optimized conditions.

Feeding effects of total mixed ration on rumen metabolic profile in Cattle

A feeding trial was undertaken to select the best combination of roughage and concentrate based on total mixed ration (TMR), to better rumen environment and determine the feeding effects of TMR on rumen metabolic profile in cattle. The experiment was conducted at Bangladesh Livestock Research Institute (BLRI) for a period of 35 days. A total of 5 types of TMR was prepared on fed basis with different roughage and concentrate ratios as T1=70:30, T2=60:40, T3=50:50, T4=40:60, and T5=30:70. Five cannulated bulls with an average live weight ranging from 200 to 300 kg and approximately 18 months of age were selected for the experiment. The present study indicated that there was no significant difference in pH among different treatment groups. Concentration of total volatile fatty acids (TVFAs) was highest in T2 group which was found to be increased up to 12 h after feeding, then gradually decreased up to 24 h. Concentration of total nitrogen (TN), ammonia nitrogen (NH3-N), non protein nitrogen (NPN) and protein nitrogen (PN) were highest in T5 group. Concentration of total nitrogen (TN), ammonia nitrogen (NH3-N) and protein nitrogen (PN) were gradually decreased up to 12 h after feeding but then gradually increased trend observed up to 24 h. Concentration of non protein nitrogen (NPN) was found to be decreased gradually from 0 h up to 24 h after feeding. The result also indicated that rumen NH3-N was positively correlated with TN intake of the animal. It can be concluded from the present study that the TMR provided better rumen environment at different hours of digestion could be used for better rumen fermentation. The best combination of roughage to concentrate ratio (30:70) was in T5 group for better N utilization to achieve maximum performance through proper feeding which might reflect the gross return of cattle production.
 Bang. J. Anim. Sci. 2018. 47 (1): 35-39

Protein Digestion and Quality of Goat and Cow Milk Infant Formula and Human Milk Under Simulated Infant Conditions.

ABSTRACTObjective:The aim of this study was to determine the kinetics of true ileal protein digestion and digestible indispensable amino acid score (DIAAS) of a goat milk-based infant formula (GIF), a cow milk-based infant formula (CIF), and human milk (HM).Methods:The GIF, CIF, and HM were investigated in an in vitro gastrointestinal model simulating infant conditions. Digested compounds were dialyzed from the intestinal compartment as bioaccessible fraction. Dialysate was collected in 15 to 60-minute periods for 4 hours. True ileal protein digestibility and DIAAS were determined as bioaccessible nitrogen (N) and amino acids.Results:N bioaccessibility from the GIF showed similar kinetics to that of HM. The CIF showed a delay in N bioaccessibility versus the GIF and HM. In the 1st hour of digestion, N bioaccessibility was 19.9% ± 3.5% and 23.3% ± 1.3% for the GIF and HM, respectively, and 11.2% ± 0.6% for CIF (P < 0.05 vs HM). In the 3rd hour of digestion, the N bioaccessibility was higher (P < 0.05) for the CIF (28.9% ± 1.2%) than for the GIF (22.5% ± 1.6%) and HM (20.6% ± 1.0%). After 4 hours, the true ileal protein digestibility of the GIF, CIF, and HM was 78.3% ± 3.7%, 73.4% ± 2.7%, and 77.9% ± 4.1%, respectively. The DIAAS for the GIF, CIF, and HM for 0- to 6-month-old infants was 83%, 75%, and 77% for aromatic AA.Conclusion:The protein quality is not different between the GIF, CIF, and HM, but the kinetics of protein digestion of the GIF is more comparable to that of HM than that of the CIF.

Biological Pre-treatment of Surplus Sludge Using the Protease-secreting Bacteria

The performances of biological pre-treatment were compared at different inoculation ratios of Bacillus licheniformis (0.17%, 0.66%, 1.16% and 1.65%, TS/TS), in order to evaluate the influence on sludge liquefaction and its dewaterability. The analysis showed that biological pre-treatment by inoculating Bacillus licheniformis accelerated the dissolution of intracellular materials and increased the degradation of protein, but the sludge dewaterability deteriorated. When the inoculation ratio of Bacillus licheniformis was 1.16%, the cumulative effect of dissolved organic carbon reached its maximum. Keeping increasing the inoculation ratio would not result in any improvement. At an inoculation ratio of 1.16%, the quantity of protein per volatile solid reached the minimum, which was 72% of the initial value, after 129 hours of digestion, which reflected the maximal degradation rate of protein. But at same time, the value of CST of sludge doubled, which indicated the deterioration of sludge dewaterability.

Microscopic Analysis of in Vitro Digested Milled Barley Grains : Influence of Particle Size Heterogeneity

In this study, Scanning Electron Microscopy (SEM) is used to characterize the structure of ground and whole barley grain before and after the exposure to in vitro enzymatic digestion at different incubation times (0, 0.5, 1, 2, 6 and 24 h). SEM analysis showed that digestion started to take place in barley grain fragments after 0.5 h of incubation time. SEM indicated that complete starch digestion is dependent on grain fragment size in barley. Starch digestion seems to be completed after 24 hours of digestion in small fragments of barley grains ( 1.0mm). In case of whole barley grain, SEM showed that alpha amylase was not capable of penetrating and diffusing through barley grain husk after 24 h of incubation. In conclusion, microscopic examination for in vitro digested milled and unprocessed barley fragments differ in particle size, indicating that the extent of starch digestion is dependent on fragment particle size.

Physical Property Changes in Raw and Roasted Almonds during Gastric Digestion In vivo and In vitro

The rate of almond breakdown during gastric digestion may be influenced by structural changes that occur during roasting. The primary objective of this study was to investigate in vivo physical property changes of raw and roasted almonds during gastric digestion, using the growing pig as a model for an adult human. Seventy two male pigs were fed a meal of raw or roasted almonds and digested samples were taken 20, 60, 180, 300, 480, and 720 min after meal consumption from the proximal and distal stomach regions. Particle size distribution, rheological flow behavior, and textural attributes of gastric digesta were measured. Particle size distributions were fit to the Rosin-Rammler function to determine the median particle diameter (x50) and distribution spread (b) parameters. Median particle diameter was statistically influenced by stomach region (p < 0.0001). Evidence of gastric sieving was observed by an increased median particle diameter and narrower distribution spread in the distal region. To elucidate on textural changes of diced almonds during digestion, an in vitro study was conducted in a static gastric environment. Results indicated that a majority of textural changes occurred during the first hour of digestion, a trend unobserved in the in vivo trial. No significant differences in physical property changes were observed between raw and roasted almonds during gastric digestion in vivo as measured by particle size distribution, textural attributes, and rheological flow behavior. This suggests that raw and roasted almonds break down at a similar rate in the gastric environment.

A Systematic Reevaluation of Enzymatic Isolation Methodology for Nucleus Pulposus Cells

IntroductionThe nucleus pulposus (NP) is the central part of IVD and understanding its function is essential for studying IVD degeneration. Enzymatic digestion by collagenase is used to release cel...

P059 Les peptides et les cinétiques de la digestion intestinale des protéines laitières chez l’homme

Milk proteins are of interest as they contain soluble (SP) and non-soluble (casein) fractions that behave differently during digestion. SP are rapidly evacuated from the stomach whereas gastric emptying of casein is delayed (Boirie et al. 1997). This difference that has been demonstrated in vitro or in vivo in animals and in humans induces differential appearance of derived peptides and amino acids in the blood and postprandial metabolic response. This study aims to assess in humans the intestinal digestion kinetics of both protein fractions. It has been performed on 16 in good health volunteers whose diets were standardized during 9 days. On the 9th day they ingested the meal composed among others of 30 g of either casein or SP. Ileal effluents were continuously collected every 30 min for 6 hours using a double lumen nasogastric tube that migrated to the jejunum. In order to verify whether casein and SP present differential digestion in jejunum, immunoreactive proteins were quantified and peptides were identified using proteomic tools (chromatography coupled on line with mass spectrometry). This study shows that i) immunoreactive proteins and peptides were present in a greater amount during the first hour of digestion for SP meal whereas a two-step digestion was observed for casein meal: a first one at 1.5-2.5 hours and a second one 4-5 hours after meal ingestion, ii) large protein fragments were present within the jejunum for both meals thus demonstrating that proteins digestion was incomplete in the jejunum, and iii) the peptides derived from casein were smaller than the ones from SP. The digestion of casein and soluble proteins differed in both the intestinal kinetics and the molecular weight of the peptides. These differences offer several applications in overweight and elderly people or in patients with wasting disorders

Chemical composition and enzymatic digestibility of sugarcane clones selected for varied lignin content

BackgroundThe recalcitrance of lignocellulosic materials is a major limitation for their conversion into fermentable sugars. Lignin depletion in new cultivars or transgenic plants has been identified as a way to diminish this recalcitrance. In this study, we assessed the success of a sugarcane breeding program in selecting sugarcane plants with low lignin content, and report the chemical composition and agronomic characteristics of eleven experimental hybrids and two reference samples. The enzymatic digestion of untreated and chemically delignified samples was evaluated to advance the performance of the sugarcane residue (bagasse) in cellulosic-ethanol production processes.ResultsThe ranges for the percentages of glucan, hemicellulose, lignin, and extractive (based on oven-dry biomass) of the experimental hybrids and reference samples were 38% to 43%, 25% to 32%, 17% to 24%, and 1.6% to 7.5%, respectively. The samples with the smallest amounts of lignin did not produce the largest amounts of total polysaccharides. Instead, a variable increase in the mass of a number of components, including extractives, seemed to compensate for the reduction in lignin content. Hydroxycinnamic acids accounted for a significant part of the aromatic compounds in the samples, with p-coumaric acid predominating, whereas ferulic acid was present only in low amounts. Hydroxycinnamic acids with ester linkage to the hemicelluloses varied from 2.3% to 3.6%. The percentage of total hydroxycinnamic acids (including the fraction linked to lignin through ether linkages) varied from 5.0% to 9.2%, and correlated to some extent with the lignin content. These clones released up to 31% of glucose after 72 hours of digestion with commercial cellulases, whereas chemically delignified samples led to cellulose conversion values of more than 80%. However, plants with lower lignin content required less delignification to reach higher efficiencies of cellulose conversion during the enzymatic treatment.ConclusionSome of the experimental sugarcane hybrids did have the combined characteristics of high biomass and high sucrose production with low lignin content. Conversion of glucan to glucose by commercial cellulases was increased in the samples with low lignin content. Chemical delignification further increased the cellulose conversion to values of more than 80%. Thus, plants with lower lignin content required less delignification to reach higher efficiencies of cellulose conversion during the enzymatic treatment.

Fibrin Resistance to Lysis in Patients with Pulmonary Hypertension Other Than Thromboembolic

Reportedly, fibrin isolated from patients with chronic thromboembolic pulmonary hypertension (CTEPH) is resistant to lysis. Persistence of regions within the fibrin beta chain, which mediate cell signaling and migration, could trigger the organization of pulmonary thromboemboli into chronic intravascular scars. Ascertain whether fibrin resistance to lysis occurs in patients with pulmonary hypertension (PAH) other than CTEPH, and in those with prior pulmonary embolism (PE) and no pulmonary hypertension. Fibrinogen was purified from 96 subjects (17 with CTEPH, 14 with PAH, 39 with prior PE, and 26 healthy control subjects) and exposed to thrombin to obtain fibrin clots. Plasmin-mediated cleavage of fibrin beta chain was assessed hourly over a 6-hour period by polyacrylamide gel electrophoresis. Fibrin band intensity was measured by densitometry of stained gels. Data were normalized to the band intensity of the undigested protein. By 1 hour of digestion, fibrin band intensity had decreased by a median of 25% (interquartile range [IQR], 20 to 27%) in control subjects, and by 15% (IQR, 11 to 18%) in patients with prior PE (P < 0.0001). The 1-hour median reduction in band intensity was 2% (IQR, 1 to 3%) in CTEPH, and 4% (IQR, 2 to 7%) in PAH (P < 0.0001 vs. control subjects and PE). The decline in fibrin band intensity remained significantly different among the four groups up to 6 hours (P < 0.0001). Fibrin resistance to lysis occurs in pulmonary hypertension other than CTEPH and, to a smaller extent, in patients with prior PE and no pulmonary hypertension.

Ironin VitroBioavailability and Iodine Storage Stability in Double-Fortified Salt

Ferrous fumarate is useful in iron fortification because of its high bioavailability, mild taste, and relatively low cost. A ferrous fumarate premix for incorporation into salt has been developed by agglomerating ferrous fumarate with appropriate binder materials into salt-size particles followed by microencapsulation. The bioavailability of iron is critical for the usefulness of double-fortified salt. This study examined the in vitro bioavailability of various iron forms in double-fortified salt and microencapsulated ferrous fumarate premixes prepared by various techniques in an effort to identify key processing factors affecting iron bioavailability. Iron in vitro bioavailability was approximated through the rate of dissolution of iron in 0.1 N HCl, which closely approximates the acid in gastric juice. Iron in vivo bioavailability was tested using the hemoglobin repletion assay in rats. The materials and techniques used in microencapsulating ferrous fumarate had little effect on iron in vitro bioavailability: more than 90% of iron in the premixes was released during 2 hours of digestion in the simulated gastric fluid. By incorporating titanium dioxide in the coating materials, the dark reddish-brown color of ferrous fumarate was effectively masked, resulting in acceptable sensory qualities, while maintaining the stability of iodine in the salt. Iron in vivo tests in rats have confirmed that the ferrous fumarate microencapsulated in a lipid is highly bioavailable, with a bioavailability of 95% relative to ferrous sulfate. These findings were corroborated by field tests in southern India which demonstrated that double-fortified salt containing microencapsulated ferrous fumarate was effective in reducing the prevalence of iron-deficiency anemia and iodine-deficiency disorders.

Análise micro-histológica da composição botânica de misturas preestabelecidas, submetidas ao processo de digestão in vitro

A composição botânica de misturas preestabelecidas de seis espécies forrageiras foi estimada após diferentes tempos de digestão in vitro e comparadas com a composição real. Três misturas de seis espécies, com participações conhecidas, foram constituídas nos períodos chuvoso e seco e examinadas pela técnica micro-histológica. O período de amostragem interferiu na estimativa de apenas uma das misturas. Apesar das diferenças estatísticas entre a composição real das misturas e suas estimativas, nos períodos, seus índices de similaridade foram superiores a 85%. O tempo de digestão influenciou nas estimativas das misturas, dependendo da porcentagem de participação das espécies. As estimativas foram idênticas para as três misturas após 48 e 72 horas de digestão. A digestão das amostras pode melhorar ou piorar as estimativas, dependendo da porcentagem de participação e da resistência das espécies. O processo digestivo não deve ser considerado como único fator de variação quando se utiliza esta técnica, que pode ser considerada robusta, uma vez que os índices de similaridade entre os períodos, o tempo de digestão e a composição real foram superiores a 75%.