Publications by authors named "Croom W"

Hypothesis: In a cadaveric irreparable rotator cuff tear model, patellar tendon allograft-superior capsule reconstruction (PT-SCR) will restore glenohumeral stability and reduce subacromial contact pressures without significant graft deformation during testing.

Methods: Eight cadaveric shoulders were tested in a custom shoulder testing system. Rotational range of motion (ROM), superior translation, and subacromial contact pressure were measured in the following experimental conditions: intact rotator cuff, irreparable supraspinatus tear (massive cuff tear [MCT]), and PT-SCR.

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Objectives: To determine native individual bilateral differences (IBDs) in femoral version in a diverse population.

Methods: Computed tomography scans with complete imaging of uninjured bilateral femora were used to determine femoral version and IBDs in version. Age, sex, and ethnicity of each subject were also collected.

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Jones fractures are reportedly prone to nonunion and generally treated with a period of non-weightbearing or operative treatment. Extended non-weightbearing can have adverse effects, and operative treatment poses various risks. We report the clinical results of patients treated without weightbearing restriction.

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The concept of improving animal health through improved gut health has existed in food animal production for decades; however, only recently have we had the tools to identify microbes in the intestine associated with improved performance. Currently, little is known about how the avian microbiome develops or the factors that affect its composition. To begin to address this knowledge gap, the present study assessed the development of the cecal microbiome in chicks from hatch to 28 days of age with and without a live Salmonella vaccine and/or probiotic supplement; both are products intended to promote gut health.

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Direct-fed microbials (DFM) could serve as a potential alternative to the feeding of antibiotics in poultry production. In this study, the effects of providing a DFM were compared with the feeding of salinomycin on intestinal histomorphometrics, and microarchitecture was examined. Broiler chicks (n=18 per treatment; trials 1 and 2) were fed a standard starter diet (control), control+PrimaLac (DFM; 0.

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The hypothesis was proposed that the carbohydrate in the first diet fed to turkey hatchlings upregulates the glucose transport system. Heavy and light body mass poults were observed to determine differences in glucose transport and carbohydrate digestion. Poults were weighed immediately posthatching.

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Incomplete uterine involution is the putative cause of the increased embryo mortality and reproductive failure often exhibited by sows that lactate for less than 21 days. Since such short lactation lengths are common in American swine production, an effective technique to monitor the postpartum involution process and test this hypothesis might be valuable. Rapid and extensive catabolism of uterine collagen is essential for normal postpartum involution.

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The effects of in ovo Peptide YY (PYY) administration on growth and feed conversion ratios in a commercial broiler line were investigated. Six hundred Ross male x Cobb female eggs were administered either 0.9% saline (control) or 600 microg/kg egg weight PYY in ovo at Day 18 of incubation.

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Mice trisomic for the distal portion of MMU 16 (Ts65Dn) were examined for differences in jejunal function and plasma amino acids as compared to diploid controls. Eighteen control and 19 Ts65Dn mice were compared for whole-body and intestinal O2 consumption, jejunal glucose uptake, and plasma amino acid concentrations. Ts65Dn mice consumed less (P < 0.

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Five-wk-old male mice from three lines were used to examine whether the apparent energetic efficiency of active jejunal glucose uptake in mouse jejunum is altered by genetic selection for different body composition. The mice lines were selected as follows: HE, high percentage of body fat with no change in body weight as a constraint; LF, low percentage of body fat; and RS, randomly bred control. Body weight was similar in all lines.

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Five-wk-old male mice from high growth (M16) and randomly bred control (ICR) lines, plus their reciprocal crosses, ICR x M16 and M16 x ICR, were used to investigate whether whole-body O2 consumption, jejunal respiration, jejunal glucose absorption and the apparent energetic efficiency of jejunal active glucose uptake in mice are altered by genetic selection for growth as well as by heterosis and maternal effects. Whole-body O2 consumption was measured in 12 mice from each line or cross. The mice were later killed for measurement of jejunal O2, using tissue respiration chambers and jejunal glucose transport determined by 3H-3-O-methylglucose accumulation.

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In digesting and absorbing dietary nutrients, the gastrointestinal tract consumes approximately 20% of all incoming energy. A substantial proportion of this consumption is due to the rapid turnover of cellular protein, which permits abrupt changes in gut size to occur, matching capacity with delivery. If it is size of the alimentary tract that constrains nutrient uptake, greater than 20% allocation of ME intake above maintenance to the gut would improve the growth rate of a young animal but the efficiency of ME utilization for growth would deteriorate.

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Terminal hydrolysis of oligosaccharides at the small intestinal brush border yields monomeric glucose, most of which is then absorbed by the transepithelial route. This involves carrier-mediated processes requiring specialized functional proteins situated in the brush border (SGLT1) and basolateral (GLUT2) membranes. Glucose translocation at the enterocyte apical membrane is an active, Na(+)-dependent and saturable process, whereas exit from enterocytes is by facilitated diffusion and is energy-independent.

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The influence of slaframine (SF), a parasympathomimetic compound isolated from the fungus Rizoctonia leguminicola, on circulating metabolic hormone concentrations was investigated in goats. In Exp. 1, SF was administered i.

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The effect of duodenal slaframine (SF) infusion on site and extent of digestion was determined using four steers equipped with ruminal, duodenal, and ileal cannulas in a 4 x 4 Latin square. A 77% dry-rolled corn diet was provided in 12 equal portions daily at a DMI of 2.26% BW.

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The history of "slobbers syndrome," a mycotoxicosis associated with Rhizoctonia leguminicola infestation of pastures and stored forages, is discussed. The chemistry and physiological effects of the two known biologically active alkaloids of R. leguminicola, slaframine and swainsonine, are described.

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Experiments were conducted to determine 1) the effect of injecting slaframine (SF) on salivary output in growing beef steers and 2) whether increased salivary output after SF injection would inhibit the decrease in ruminal pH that occurs after experimentally induced subacute and acute ruminal acidosis. In Exp. 1 and 2, we measured ruminal pH and salivary output in ruminally and esophageally cannulated beef steers fed an 88% concentrate diet.

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Small intestinal glucose absorption and gastrointestinal morphology were compared in adult bovine somatotropin transgenic (MT-bGH) and control mice. The MT-bGH mice were 57% heavier than controls, although both groups consumed comparable amounts of food during the 5 d before transport measurements were made. Stomach, cecum and colon were 98, 53, and 81% heavier (P < 0.

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Eight Holstein cows were assigned following calving to two groups, balanced for parity, using a continuous completely randomized block design. Cows were fed a diet with 13.5% CP and 22.

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The effects of epidermal growth factor on intestinal glucose transport were examined in mice. Glucose transport measurements were performed using an in vitro assay system that estimated the rate of accumulation of [3H]3-O-methyl-D-glucose. In Experiment 1, two-mo-old male and female mice were subcutaneously injected once daily with 0, 150 or 300 micrograms epidermal growth factor/kg body weight for 3 d.

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Three Holstein steers (345 +/- 22 kg) surgically fitted with a pancreatic cannula were used in two 3 x 3 Latin square design experiments to examine the effects of slaframine (SF), a muscarinic agonist, or 4-diphenylacetoxy-N-methylpiperidine methiodide (4DAMP), an M3 muscarinic glandular receptor antagonist, on pancreatic exocrine secretion. Pancreatic exocrine secretion was collected for 8 h postdosing at 30-min intervals beginning 1 h postfeeding. In experiment 1, steers were dosed with 0, 25, or 50 micrograms.

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Discussed herein are the constraints of nutrient delivery from the gastrointestinal tract that are placed on postabsorptive synthetic processes in highly selected strains of domestic livestock or livestock treated with growth promotants exogenously or via transgenic manipulation. Emphasis is placed on the discussion of recent advances in the knowledge of the regulation and manipulation of digestion and the absorption by the intestinal epithelium. Slaframine, a muscarinic exocrine secretagogue with a high affinity for the gastrointestinal tract, and epidermal growth factor may have practical potential for the manipulation of digestion and absorption, respectively.

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Sixteen mature, ruminally cannulated wethers (average BW = 41 +/- 1 kg) were fed a low-quality hay diet with or without a cottonseed meal (CSM) supplement and the parasympathomimetic agonist slaframine (SF). Treatments were basal diet (Mitchell grass hay, 4.8% CP, 46.

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An organ explant culture system for the intact chick pancreatic splenic lobe (SL) was characterized for exocrine function. Organ cultures were prepared using the pancreatic splenic lobe from 9- and 15-day-old male broiler chicks (Arbor Acres x Arbor Acres) to characterize amylase release as well as tissue integrity during 2, 4, 8, and 12 h of incubation. Light microscopy studies indicated necrosis of the exocrine pancreatic acini after 4 h of incubation.

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Mechanisms regulating ruminant pancreatic exocrine function differ in some respects from those in nonruminants. This may affect the post-ruminal digestion of certain dietary nutrients such as starch. Ruminants do not exhibit clearly defined cephalic and gastric phases of pancreatic regulation, a likely consequence of the continuous nature of digesta flow from the rumen.

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