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Biomedical subjects

E M Weaver

Publications and source records attributed to E M Weaver.

17 recordsLinked to original sources
PubMed2005

Effects of spray-dried animal plasma and immunoglobulins on performance of early weaned pigs.

Five experiments were conducted to evaluate the effects of dietary spray-dried porcine plasma (SDPP) and spray-dried bovine plasma (SDBP) and their various molecular weight fractions on performance of pigs weaned at approximately 14 or 21 d of age. In addition, the efficacy of various levels of the immunoglobulin G (IgG)-rich fraction of SDPP and SDBP were evaluated. Experiment 1 evaluated the dietary addition of SDPP and three of its fractions (IgG-rich, albumin-rich, and low molecular weight fractions). Pigs fed SDPP grew faster and consumed more feed than the controls during the first week (P < 0.05). The IgG-rich fraction resulted in improvements in ADG and ADFI that were similar to those of pigs fed SDPP. The albumin-rich fraction had no effect on growth rate, but the low molecular weight fraction decreased feed intake as well as growth rate. Experiments 2 and 3 evaluated SDPP and graded levels of its IgG-rich fraction in pigs weaned at 21 or 14 d, respectively. In Exp. 2, pigs fed SDPP grew faster and consumed more feed than the controls during the first week (P < 0.05). Pig performance was enhanced with the addition of the IgG-rich fraction that provided 80% of the amount of IgG in the SDPP diet. In Exp. 3, there was no response to SDPP during the first week, but a positive growth response to SDPP (P < 0.01) occurred by the end of wk 2 (0 to 14 d). Feeding the IgG-rich fraction increased growth rate compared with controls (P < 0.05). Over the entire experiment, the greatest ADG occurred with the IgG-rich fraction that provided 128% of the amount of IgG provided by SDPP (quadratic; P < 0.05). Two additional experiments assessed feeding SDBP and bovine IgG-rich fractions to early weaned pigs. In Exp. 4, SDPP was superior to SDBP in stimulating growth and feed intake, but this difference did not occur in Exp. 5. In both experiments, the IgG fraction of bovine plasma seemed to be as effective at improving growth as SDPP and more effective than SDBP. The results indicate that both porcine and bovine plasma are beneficial to young pig performance during the first week after weaning and that the IgG fraction of plasma is the component that is responsible for the enhancement in growth rate and feed intake.

Animal Feed↗
PubMed2004

Arginine stimulates intestinal cell migration through a focal adhesion kinase dependent mechanism.

BACKGROUND: L-Arginine is a nutritional supplement that may be useful for promoting intestinal repair. Arginine is metabolised by the oxidative deiminase pathway to form nitric oxide (NO) and by the arginase pathway to yield ornithine and polyamines. AIMS: To determine if arginine stimulates restitution via activation of NO synthesis and/or polyamine synthesis. METHODS: We determined the effects of arginine on cultured intestinal cell migration, NO production, polyamine levels, and activation of focal adhesion kinase, a key mediator of cell migration. RESULTS: Arginine increased the rate of cell migration in a dose dependent biphasic manner, and was additive with bovine serum concentrate (BSC). Arginine and an NO donor activated focal adhesion kinase (a tyrosine kinase which localises to cell matrix contacts and mediates beta1 integrin signalling) after wounding. Arginine stimulated cell migration was dependent on focal adhesion kinase (FAK) signalling, as demonstrated using adenovirus mediated transfection with a kinase negative mutant of FAK. Arginine stimulated migration was dependent on NO production and was blocked by NO synthase inhibitors. Arginine dependent migration required synthesis of polyamines but elevating extracellular arginine concentration above 0.4 mM did not enhance cellular polyamine levels. CONCLUSIONS: These results showed that L-arginine stimulates cell migration through NO and FAK dependent pathways and that combination therapy with arginine and BSC may enhance intestinal restitution via separate and convergent pathways.

Animals↗
PubMed2001

Radiofrequency treatment of turbinate hypertrophy in subjects using continuous positive airway pressure: a randomized, double-blind, placebo-controlled clinical pilot trial.

OBJECTIVES: To estimate the treatment effect of temperature-controlled radiofrequency (TCRF) reduction of turbinate hypertrophy in patients with sleep-disordered breathing (SDB) treated with nasal continuous positive airway pressure (CPAP), and to assess the impact of study design on this estimate. STUDY DESIGN: Prospective, randomized, double-blind, placebo-controlled clinical pilot trial. METHODS: Twenty-two CPAP-treated patients with SDB with turbinate hypertrophy were randomly assigned to either TCRF turbinate treatment (mean energy 415 +/- 37 J/turbinate; n = 17) or placebo control (n = 5). Changes in nasal obstruction were evaluated between pretreatment and 4 weeks post-treatment. The primary outcome assessed changes in the blinded examiners' findings of nasal obstruction on a visual analogue scale (VAS). Secondary outcomes included blinded patients' and unblinded examiner assessments of nasal obstruction (VAS), nightly CPAP use, adherence, and tolerance, along with sleepiness and general health status scales. The treatment group findings were subtracted from the changes in the placebo group to yield treatment effect. RESULTS: The primary outcome treatment effect by VAS was -0.9 cm (95% confidence interval [CI], -2.4, 0.7), and beyond the placebo effect of -1.5 cm (95% CI: -3.4, 0.3). The secondary treatment effect of the unblinded examiner was -3.0 cm (95% CI, -4.9, -1.1). A beneficial treatment effect was also seen on every secondary outcome except general health status, but only self-reported CPAP adherence (P = .03) was statistically significant. CONCLUSIONS: TCRF turbinate treatment appears to benefit nasal obstruction and CPAP treatment for SDB. Placebo control and double blinding are critical for establishing the true treatment effect. A future definitive trial is feasible to establish statistical significance of these findings.

Adult↗
PubMed1999

Effect of internal maxillary arterial occlusion on nasal blood flow in swine.

OBJECTIVES: The precise effects of therapeutic occlusion of the internal maxillary artery (IMA) on distal nasal mucosal perfusion are unknown. A better understanding of these effects has important implications regarding the rationale and expected efficacy of certain therapeutic interventions for epistaxis management. The authors developed an animal model to assess these issues. STUDY DESIGN: The effects of "proximal" and progressively more "distal" occlusions of the IMA on nasal mucosal blood flow (NBF) were assessed in anesthetized swine using continuous laser Doppler flowmetry. The levels of arterial occlusion were selected to simulate clinical therapeutic occlusions used for the management of epistaxis. METHODS: Nineteen swine were entered into one of four experimental groupings: proximal IMA occlusion using platinum micro-coils (n = 6), mid-grade distal IMA occlusion with polyvinyl alcohol particulate (PVA) suspensions (300 to 500 microns, n = 5), high-grade distal IMA occlusion with polyvinyl alcohol particulate suspensions (50 to 150 microns, n = 5), and sham control (n = 2). RESULTS: All embolizations resulted in acute decreases in average NBF from 120 mL/min per 100 g to 40 mL/min per 100 g (P < .05 for all groups). NBF returned to baseline in all three treated groups within 2 to 8 days after therapeutic embolization, depending on the level of occlusion (coils, 2 d; mid-grade PVA, 2-3 d; high-grade PVA, 8 d). Follow-up angiography showed recanalization and collateralization as possible methods of reestablishing NBF. CONCLUSIONS: This study supports the rationale for performing distal IMA occlusion with transarterial particulate embolization, in order to provide a longer period of time of diminished NBF. This theoretically should promote hemostasis within an injured portion of the nasal mucosa by decreasing perfusion pressure within the capillary bed. However, the benefits of distal IMA embolization must be balanced against potential ischemic complications, as may be more commonly seen with high-grade particulate embolization.

Animals↗
PubMed1998

Prognostic staging system for recurrent, persistent, and second primary cancers of the oral cavity and oropharynx.

OBJECTIVE: To develop a practical staging system for predicting mortality of patients with recurrent squamous cell tumors of the oral cavity and oropharyngeal mucosa. DESIGN AND SETTING: An inception cohort at an academic medical center. PATIENTS: A total of 308 patients who had evidence of recurrent, persistent, or second primary tumors of the oral cavity and oropharynx between January 1, 1980, and December 31, 1991, of whom 162 (52.6%) met inclusion criteria. MAIN OUTCOME MEASURE: One-year mortality. RESULTS: The median survival time was 10 months. In bivariate analysis, the TNM stage of the recurrent tumor, invasion of pharyngeal constrictors and the floor-of-mouth muscles, weight loss, local and systemic symptoms, and eating function had significant effects on mortality. Multivariable analysis (done by conjunctive consolidation and Cox regression) identified constrictor invasion, the TNM stage of the recurrence, and weight loss as having a substantial effect on mortality. A composite 4-stage system using these 3 variables demarcated 1-year survival rates of 88.2% (30/34), 71.9% (23/32), 32.6% (16/49), and 4.2% (2/47). CONCLUSIONS: The TNM status of recurrent tumors predicts mortality, but constrictor muscle invasion and weight loss also have major prognostic importance. The consolidation of these variables into a composite staging system successfully stratifies patients with widely divergent mortality rates. Improved staging of recurrent head and neck tumors can lead to more effective decisions about the comparisons and merits of additional treatment.

Aged↗
PubMed1998

Percutaneous direct-puncture acrylic embolization of a pseudoaneurysm after failed carotid stenting for the treatment of acute carotid blowout.

We report a difficult case of recurrent carotid blowout syndrome in a patient who had a rupture of the common carotid artery with formation of a large pseudoaneurysm. Conventional management of this emergency, consisting of composite occlusion of the internal and common carotid arteries, was not possible owing to prior clinical failure of balloon test occlusion. This led to an initial attempt to cover the site of rupture with overlapping self-expanding stents, which was only temporarily successful in controlling the hemorrhage. When a subsequent episode of carotid rupture with life-threatening hemorrhage occurred, percutaneous direct-puncture acrylic embolization with temporary flow arrest was used to successfully obliterate the pseudoaneurysm.

Acrylates↗
PubMedDate not supplied

True malignant mixed tumor (carcinosarcoma) of tonsillar minor salivary gland origin: diagnostic imaging and endovascular therapeutic embolization.

We report a case of carcinosarcoma of the minor salivary glands of the left palatine tonsil, an especially rare location. Imaging characteristics assessed at CT, MR imaging, and angiography are presented. In addition, we describe our experience with preoperative therapeutic endovascular embolization of this hypervascular tumor.

Arteries↗