J. Elnif - Academia.edu (original) (raw)

Papers by J. Elnif

The Journal of nutrition, 2002

Maturation of gastrointestinal (GI) function in neonates is stimulated by enteral nutrition, wher... more Maturation of gastrointestinal (GI) function in neonates is stimulated by enteral nutrition, whereas parenteral nutrition induces GI atrophy and malfunction. We investigated whether preterm birth alters the GI responses to parenteral and enteral nutrition. Pigs were delivered either preterm (107 d gestation) or at term (115 d gestation) and fed total parenteral nutrition (TPN) or enteral sow's milk (ENT) for 6 d after birth. Immaturity of the preterm pigs was documented by reduced blood pH, oxygen saturation and neutrophil granulocyte function, impaired intestinal immunoglobulin G uptake from colostrum, and altered relative weights of visceral organs (small intestine, liver, spleen, pancreas, and adrenals). For both ages at delivery, increases occurred in pancreatic weight (30-75%) and amylase activity (0.5- to 13-fold) after birth, but much more in ENT than in TPN pigs (P < 0.05). Six days of TPN feeding was associated with reduced intestinal weight for both delivery groups ...

The Journal of nutrition, 2001

Uptake of colostrum just after birth is essential to stimulate intestinal growth and function, an... more Uptake of colostrum just after birth is essential to stimulate intestinal growth and function, and in many species, including pigs, colostrum also provides immunological protection via the absorption of immunoglobulin G (IgG). In this study, intestinal growth, IgG absorptive capacity and enzyme activities were investigated in newborn pigs in response to different diets. Newborn piglets were bottle-fed porcine colostrum (PC), bovine colostrum (BC), porcine plasma (PP), porcine milk (PM), bovine colostrum containing porcine plasma (BCP) or a milk replacer (MR) every 3 h (15 mL/kg) for up to 2 d. Bovine serum albumin (BSA) was added to the diets as a macromolecule marker. The percentage of absorbed BSA just after birth was highest for piglets fed the PC diet (30-50%), lower for those fed the BC and BCP diets (23-30%) and lowest for the PP, PM and MR diet-fed piglets (7-20%, P < 0.05 relative to those fed colostrum). Porcine IgG was absorbed more efficiently than bovine IgG. Intestin...

American journal of physiology. Regulatory, integrative and comparative physiology, 2001

Amino acids originating from the diet are the principal metabolic fuels for the small intestine, ... more Amino acids originating from the diet are the principal metabolic fuels for the small intestine, and although the developing intestine is exposed to dramatic changes in the types and amounts of protein, there is little known about rates of amino acid absorption across the apical membrane during development. Therefore, rates of absorption were measured for five amino acids that are substrates for the acidic (aspartate), basic (lysine), neutral (leucine and methionine), and imino (proline) amino acid carriers using intact tissues from the proximal, mid-, and distal small intestines of pigs ranging in age from 90% of gestation to 42 days after birth (12 days after weaning). Rates of absorption (sum of carrier-mediated and apparent diffusion) were highest at birth (except for proline) and declined by an average of 30% during the first 24 h of suckling. There were continuing declines for leucine, methionine, and proline but not for aspartate and lysine. Due to rapid growth of the intesti...

American journal of physiology. Gastrointestinal and liver physiology, 2000

We wished to determine whether exogenous glucagon-like peptide (GLP)-2 infusion stimulates intest... more We wished to determine whether exogenous glucagon-like peptide (GLP)-2 infusion stimulates intestinal growth in parenterally fed immature pigs. Piglets (106-108 days gestation) were given parenteral nutrient infusion (TPN), TPN + human GLP-2 (25 nmol. kg(-1). day(-1)), or sow's milk enterally (ENT) for 6 days. Intestinal protein synthesis was then measured in vivo after a bolus dose of [1-(13)C]phenylalanine, and degradation was calculated from the difference between protein accretion and synthesis. Crypt cell proliferation and apoptosis were measured in situ by 5-bromodeoxyuridine (BrdU) and terminal dUTP nick-end labeling (TUNEL), respectively. Intestinal protein and DNA accretion rates and villus heights were similar in GLP-2 and ENT pigs, and both were higher (P < 0.05) than in TPN pigs. GLP-2 decreased fractional protein degradation rate, whereas ENT increased fractional protein synthesis rate compared with TPN pigs. Percentage of TUNEL-positive cells in GLP-2 and ENT gr...

Comparative biochemistry and physiology. Part A, Physiology, 1996

The effect of glucocorticoids on the growth of digestive organs was investigated in the postnatal... more The effect of glucocorticoids on the growth of digestive organs was investigated in the postnatal period of mink. A total of 110 mink kits from 20 litters were either not injected or injected intramuscularly for seven days with saline, adrenocorticotropic hormone (ACTH, 50 micrograms/kg/day) or hydrocortisone-acetate (synthetic glucocorticoid, 50 mg/kg/day). The kits were killed at 2-10 weeks of age. Plasma cortisol levels did not change significantly with age in the control animals. In the ACTH group, plasma cortisol was minimum at 4 weeks of age, whereas in the hydrocortisone-acetate group, plasma cortisol was maximum at this age. The mink appears to have a period of reduced adrenal responsiveness to ACTH and a low metabolic clearance rate of cortisol around 4 weeks of age. The weight of the ventricle, pancreas and intestine per body weight reached a maximum at 6-8 weeks of age. Hydrocortisone-acetate treated kits showed reduced body growth at 2-6 weeks and increased weight of the...

Journal of Nanotechnology, 2012

Silver nanoparticles (AgNano) as carrier of available oxygen (O 2 ) and with high surface reactiv... more Silver nanoparticles (AgNano) as carrier of available oxygen (O 2 ) and with high surface reactivity may increase O 2 consumption, enhance fat uptake (FU), and stimulate growth and development. The objective was to investigate the effects of in ovo injection of AgNano on the metabolic rate (O 2 consumption, CO 2 production, and heat production, HP), fat uptake, and the development of broiler and layer hatchlings. AgNano concentrations (50, 75, and 100 mg/kg) were injected in ovo at day 1 of incubation to different breeds of broiler and layer chicken embryos. Oxygen consumption and subsequently FU did not increase linearly following AgNano treatment. FU was lower in hatchlings treated with 50 and 100 mg AgNano/kg, but surprisingly not in hatchlings treated with 75 mg AgNano/kg. Interestingly, the difference in FU between treatments was not reflected in hatchling development. The results indicated that AgNano affected metabolic rate and FU; however, it did not influence the development of hatchlings. This suggests that in ovo injection of AgNano reduces the need to use yolk fat as an energy source during embryonic development and consequently the remaining fat in the residual yolk sac may provide a potent source of nutritional reserves for chicks of few days after hatching.

Archives of animal nutrition, 2012

This study evaluated the potential of silver nanoparticles (AgNano) as an antimicrobial growth-pr... more This study evaluated the potential of silver nanoparticles (AgNano) as an antimicrobial growth-promoting supplement for broiler chickens. One hundred forty-four seven-day-old broiler chicks were distributed randomly to AgNano treatments at 0, 10 and 20 mg/kg (Control, Group AgNano10, and Group AgNano20, respectively) provided via the drinking water from day 7 to 36 post-hatching. Body weight and feed consumption were measured weekly. In addition, balance and respiration experiments were carried out to determine nitrogen (N) utilisation and energy retention. At days 22 and 36, blood samples and intestinal content were collected to evaluate the effects of AgNano on plasma concentration of immunoglobulins and the intestinal microflora, respectively. The provision of water solutions containing different concentrations of AgNano had no effect on postnatal growth performance and the energy metabolism of broiler chickens. However, in Group AgNano10 N intake (p = 0.05) and retention (p = 0....

British Journal of Nutrition, 1997

Ten adult female mink (Mustela vison) were studied in a 7 d balance experiment consisting of a 2 ... more Ten adult female mink (Mustela vison) were studied in a 7 d balance experiment consisting of a 2 d pre-surgery feeding period, followed by surgery, 1 d of recovery 4 d of ad libitum feeding, and a 2 d fasting period. In this experiment (Expt A) the animals had osmotic pumps implanted for continuous release of radioactively-labelled p-aminohippuric acid (p-aminobenzoyl-2-[3H]glycine; [3H]PAH; n 10) and 14C-labelled inulin ([14C]IN; n 5). Repeated 24 h collections of urine, corrected to 100% [3H]PAH or [14C]IN recovery, were used for accurate determination of N balances, 24 h urinary excretion of urea, creatinine, and total N, and calculation of mean 24 h renal clearance rates for endogenous creatinine and inulin. N balances were slightly below zero, but not significantly different between feeding and fasting periods, indicating that correction to 100% [3H]PAH recovery resulted in slight overestimation of the final balances. During fasting, withdrawal of the dietary water and protein loads resulted in a dramatic decline in 24 h urinary volume, and urea and creatinine excretion. Large individual variations in 24 h urinary creatinine excretion (with relative variation coefficients up to 30%) confirmed that this is an unreliable index of the completeness of urine collection. In this respect, recovery rates of [3H]PAH proved far more consistent. Renal clearance values obtained in fed mink were in fair agreement with published data from cats, dogs and ferrets (Mustela putorius furo). Inulin clearance was about 30% higher than endogenous creatinine clearance, although its decline in response to fasting was not significant. In a separate study (Expt B) another ten female mink were equipped with osmotic pumps containing [3H]PAH for determination of 24 h excretion rates of purine derivatives. During feeding, allantoin accounted for more than 97% of the excretion of purine derivatives in urine, uric acid making up less than 2.5%, xanthine and hypoxanthine less than 1%. In fasted animals, urinary excretion of each of these purine derivatives declined to less than 50% of the feeding value. In conclusion, an experimental technique is presented for efficient and accurate measurements of daily urinary excretion of nitrogenous constituents, which allows for correct determination of N balances in adult mink and, presumably, in other mammalian species.

Open Access Animal Physiology, 2012

Background: Because of their unique biological properties and strong antimicrobial activity, silv... more Background: Because of their unique biological properties and strong antimicrobial activity, silver nanoparticles have received considerable attention and been used widely in an increasing number of consumer and medical products. In the present study, the potential of silver nanoparticles as an alternative antimicrobial growth-promoting supplement for broiler chickens was investigated. Methods: On day 1 of incubation, two groups of fertile eggs were injected with colloidal silver nanoparticles 10 mg/kg or 20 mg/kg. A third group was not injected and designated as a control group. At day 7 post-hatching, drinking water containing three silver nanoparticle concentrations (0, 10, and 20 mg/kg) was offered for 4 weeks. Body weight and feed consumption were measured weekly. At days 22 and 36, blood samples and intestinal contents were collected to evaluate the effects of the silver nanoparticles on plasma concentrations of immunoglobulins (IgG and IgM) and intestinal microflora. Results: In ovo injection of silver nanoparticles 10 mg/kg and 20 mg/kg and subsequent provision in the drinking water during the post-hatch period reduced feed intake by about 5.0 g/day (P = 0.02) and body weight by about 41.0 g (P = 0.001); however, no concurrent effect on feed conversion ratio was observed. Bacterial populations in the ileum were not affected. Numbers of lactose-negative enterobacteria and lactic acid bacteria decreased in the cecum (P , 0.05). Silver nanoparticle supplementation increased the concentration of acetic acid (P = 0.006), but not the concentrations of butyric, propionic, valeric, and succinic acid in the cecum. No treatment effects on plasma concentrations of IgG and IgM were noted. Conclusion: Silver nanoparticles affect feed intake, acetic acid concentration, numbers of lactosenegative and lactic acid bacteria, and immunoglobulin levels in broiler chickens. Silver nanoparticles are a potent antimicrobial agent for use in these birds. However, their activity and impact on growth performance should be explored further in a commercial poultry production setting.

Comparative Biochemistry and Physiology Part A: Molecular & Integrative Physiology, 2012

AJP: Regulatory, Integrative and Comparative Physiology, 2007

Exogenous glucagon-like peptide 2 (GLP-2) prevents intestinal atrophy and increases nutrient abso... more Exogenous glucagon-like peptide 2 (GLP-2) prevents intestinal atrophy and increases nutrient absorption in term newborn pigs receiving total parenteral nutrition (TPN). We tested the hypothesis that the immature intestine of fetuses and preterm neonates has a diminished nutrient absorption response to exogenous GLP-2. This was accomplished using catheterized fetal pigs infused for 6 days (87-91% of gestation) with GLP-2 (25 nmol.kg(-1).day(-1) iv; n = 7) or saline (n = 7), and cesarean-delivered preterm pigs (92% of gestation) that received TPN with GLP-2 (25 nmol.kg(-1).day(-1) iv; n = 8) or saline (n = 7) for 6 days after birth. Responses to GLP-2 were assessed by measuring intestinal dimensions, absorption of nutrients (glucose, leucine, lysine, proline) by intact tissues and brush border membrane vesicles, and abundance of sodium-glucose cotransporter mRNA. Infusion of GLP-2 increased circulating GLP-2 levels in fetuses, but did not increase intestinal mass or absorption of nutrients by intact tissues and brush border membrane vesicles, except for lysine. Administration of exogenous GLP-2 to preterm TPN-fed pigs similarly did not increase rates of nutrient absorption, yet nutrient absorption capacities of the entire small intestine tended to increase (+10-20%, P &amp;amp;amp;amp;amp;lt; 0.10) compared with TPN alone due to increased intestinal mass (+30%, P &amp;amp;amp;amp;amp;lt; 0.05). GLP-2 infusion did not increase sodium-glucose cotransporter-1 mRNA abundance in fetuses or postnatal preterm pigs. Hence, the efficacy of exogenous GLP-2 to improve nutrient absorption by the intestine of fetal and preterm pigs is limited compared with term pigs and more mature animals and humans.

Journal of Pediatric Gastroenterology and Nutrition, 2006

Objectives: Parenteral nutrition is a critically important intervention for children with intesti... more Objectives: Parenteral nutrition is a critically important intervention for children with intestinal dysfunctions. However, total parenteral nutrition (TPN) with no enteral feeding is associated with small intestine atrophy and malabsorption, which complicate the transition to enteral nutrition. The objective of the present study was to evaluate the therapeutic potential of the intestinotrophic peptide glucagon-like peptide 2 (GLP-2), which reduces TPN-associated atrophy and maintains nutrient absorption in adult rats, for preventing nutrient malabsorption in neonates receiving TPN. Methods: Term pigs obtained by cesarean delivery received from birth TPN alone (TPN; n = 7) or TPN with GLP-2 (25 nmol I kg j1 I d j1 ; GLP-2; n = 8) or were fed sow milk enterally (n = 7). The small intestine was removed on postnatal day 6 to measure morphological responses and absorption of glucose, leucine, lysine and proline by intact tissues and brush border membrane vesicles and to quantify the abundances of mRNA and protein for enterocyte glucose transporters (SGLT-1 and GLUT2). Results: Relative to TPN alone, administration of GLP-2 resulted in small intestines that were larger (P G 0.01), had greater abundances of mRNA and protein for SGLT-1, but not for GLUT2, and had higher capacities to absorb nutrients (P G 0.01). Moreover, the intestines of GLP-2 pigs were comparable in size and absorptive capacities with those of pigs fed sow milk enterally. Conclusions: Providing GLP-2 to neonates receiving TPN prevents small intestine atrophy, results in small intestine absorptive capacities that are comparable to when nutrients are provided enterally and may accelerate the transition from TPN to enteral nutrition.