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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
361

Effects of Probiotics on Intestinal Failure–Associated Liver Disease in Adult Patients Receiving Prolonged Parenteral Support: A Tertiary Care Center Experience

Alomari, Mohammad, Nusairat, Leen, Al Momani, Laith, Chadalavada, Pravallika, Covut, Fahrettin, Olayan, May, Young, Mark, Romero-Marrero, Carlos 01 June 2020 (has links)
Background: It has been hypothesized that dysbiosis plays a significant role in the pathogenesis of intestinal failure–associated liver disease (IFALD). Therefore, we aimed to investigate the effect of probiotics on IFALD in patients receiving parenteral support, namely home parenteral nutrition (HPN) and home intravenous fluids (HIVFs). Methods: We retrospectively reviewed charts of patients with intestinal failure who received HPN or HIVF for >2 weeks at our tertiary center between January 2005 and August 2016. We excluded patients <18 years of age, patients with other causes of liver disease, patients who used probiotics for <30 days, patients with <6 months' follow-up, and those who had long-term antibiotic use (>30 days). Bivariable and multivariable logistic regression analyses were used in this study. Results: A total of 282 patients who received parenteral support were included. Eighty-five percent of our sample received PN. A total of 78 (27.7%) patients used probiotics. The prevalence of IFALD in patients who used probiotics was 35.9% vs 54.4% in patients who did not use probiotics, P =.005. In multivariable analysis, only small-bowel length of 10-90 cm and HPN use showed a significant impact on IFALD, odds ratio (OR) = 4.394 (95% confidence interval [CI], 1.635-11.814; P =.003) and OR = 4.502 (95% CI 1.412-14.351; P =.011), respectively. Conclusion: Our study revealed that the prevalence of IFALD was comparable among the probiotic users and nonusers. Only small bowel length of 1090 cm and HPN use showed a significant impact on IFALD.
362

Alginate Beads: A Promising Vector for BMCs

Alsaggaf, Ahmed A. 17 May 2022 (has links)
Coral bleaching is a worldwide result of climate change that is affecting the marine ecosystems greatly. Methods to help solve the issue have been previously explored and Beneficial Microorganisms for Corals (BMCs) have been proven to help mitigate coral bleaching in laboratory trials. In their efforts to test its effectiveness on the field, scientists have found that it would be beneficial to have a constant, biocompatible, source of BMCs. We have tested Calcium Alginate microspheres, what we call Alginate Beads, in terms of release rate and cell viability to determine if they are fit to be used as vectors for the BMC consortia. By placing the Beads in two different temperatures representing winter and summer temperatures in the Red Sea in agitation we were able to understand their dynamics more clearly. By using Flow Cytometry, Colony Forming Units, and microscopy techniques we were able to see that Alginate Beads incorporate bacteria into their matrix and keep them viable for up to two weeks. We also observed that the Beads release more bacterial cells at higher temperatures compared to lower temperatures. This suggests that when used in the field, Alginate Beads are able to sustain the bacteria for a prolonged time period and it will release bacteria at a higher rate in warmer temperatures potentially either season or region-wise. Hence, we believe that Alginate Beads could be suitable as vectors for field research and should be explored further.
363

PREVENTION OF CLOSTRIDIUM DIFFICILE INFECTION / Prevention of Clostridium difficile infection: a systematic review and critical appraisal of clinical practice guidelines and an independent participant data meta-analysis on probiotics for prophylaxis in adults and children administered antibiotics

Lytvyn, Lyubov 11 1900 (has links)
Clostridium difficile infection (CDI) prevention is of high priority. We reviewed clinical practice guidelines (CPGs), and conducted an individual participant data meta-analysis (IPMDA) of randomized controlled trials (RCTs) to assess effectiveness and safety of probiotic prophylaxis. For CPGs, we rated quality, summarized recommendations with their strength and author-reported evidence, then re-evaluated evidence. For the IPDMA, we pooled RCTs investigating probiotics versus control for CDI prevention among antibiotic consumers, using generalized linear mixed models. Our outcomes were CDI and serious adverse events (SAEs). We adjusted for age, sex, hospitalization status, and exposure to high risk antibiotics. We assessed study risk of bias and confidence in estimates of effect. Five international guidelines were evaluated, and all scored poorly for applicability, stakeholder involvement, and rigor of development. Recommendations were not always linked to evidence, and guideline authors were not transparent about how evidence limitations impacted their decisions. None of the guidelines recommended probiotics. Fourteen studies contributed data, with one pending. Probiotics reduced CDI among all studies and the adjusted model. No covariates were significantly associated with CDI. Subgroups suggested that high incidence did not affect probiotic effectiveness, and high-dose, multi-strain probiotics were more beneficial. Our estimate was robust to sensitivity analyses. Probiotics did not significantly affect SAE odds among all studies and the adjusted model. Increasing age was a significantly associated with SAEs. No SAEs were reportedly probiotics-related. For both outcomes, estimates were similar from data of obtained and not obtained studies. Confidence in estimates was moderate for both outcomes, due to low event rates. Current guidelines on CDI prevention did not adhere well to validated standards for development and reporting, most notably due to insufficient links between recommendations and supporting evidence. Our preliminary analysis suggests that probiotic prophylaxis is useful and safe for CDI prevention. / Thesis / Master of Science (MSc) / Clostridium difficile infection (CDI) is a common hospital-associated infection, and prevention is of high priority. We reviewed clinical practice guidelines on CDI prevention to summarize their recommendations, and assess the quality of guideline development and reporting. Furthermore, we analysed patient data from randomized clinical trials to obtain an overall estimate (meta-analysis) of whether using a novel strategy, probiotic prophylaxis, is effective and safe. The guidelines had several limitations, importantly that authors were not transparent about how recommendation were developed, and recommendations were not always linked to evidence. Although no guideline recommended using probiotics to prevent CDI, our advanced analysis of previously conducted trials suggested that it was an effective intervention, reducing infections by approximately 76%, and was not associated with differences in serious adverse events compared to participants not receiving probiotics. In summary, guidelines on CDI prevention should be improved, and probiotics may be considered as an additional strategy.
364

Effectiveness Of Probiotics In Preventing Antibiotic Associated Diarrhea And Clostridium Difficile In Long Term Care

Edwards-Marshall, Marva 01 January 2010 (has links)
Problem/Purpose: Antibiotic associated diarrhea (AAD) and clostridium-difficile diarrhea (CDAD) are the most common forms of infectious diarrhea in long-term care facilities. The purpose of this study was to determine the effectiveness of probiotics in preventing AAD and CDAD in the long term care geriatric population, and to identify interventions that can be used to improve clinical practice. Background/Significance: Prophylactic use of probiotics have been purported to decrease the incidences of AAD and CDAD. Previous studies have yielded contradictory results on the efficacy of probiotics. The objective of this study was to evaluate the impact of administration of probiotics on the rate of infectious diarrhea in the Long Term Care (LTC) population Method: This was a retrospective cohort study. The charts of residents of a LTC facility who were 65 years of age and older, and were administered antibiotic therapies, with or without co-administration of probiotics were reviewed. A data collection instrument was created for this study and piloted prior to its utilization. A chi-square test of independence was calculated to obtain the results. Results: Forty-four residents received probiotics with antibiotics, five cases of diarrhea were reported; no cases of CDAD were reported. In 39 residents who received antibiotics without probiotics, two cases of diarrhea and one case of CDAD were reported. Conclusion: The study showed no statistically significant evidence to support the effectiveness of probiotic use in the prevention of AAD and CDAD in a long term care facility. The incidence of AAD was higher in the group with probiotics
365

Effects of Probiotics on the Reduction in Incidence of Necrotizing Enterocolitis in Premature (< 37 Weeks Gestation) Neonates

Cox, Makenzie 01 January 2016 (has links)
Problem: Necrotizing Enerocolitis (NEC) is one of the leading causes of morbidity and mortality in neonatal intensive care units (NICU), affecting 7% to 14% of premature neonates weighing less than 1500g (Lin et al., 2008). Healthcare costs for the treatment of NEC account for roughly 20% of the 5 billion dollars spent on infants in the NICU annually (Gephart, McGrath, Effken & Halpern, 2012). Nutritional supplements, such as probiotics, may be used prophylactically to prevent NEC in this high-risk population. Objective: A literature review was performed to examine which strains of probiotics show the most potential in reducing the incidence of necrotizing enterocolitis. Method: A literature review was performed using CINAHL, Science Citation Index, Science Direct, Medline, Academic One file, PsychINFO, and PUBMED databases. Key words included enterocolitis, Necrotizing*/PC OR NEC* AND probiotics*. After applying exclusion criteria, 9 articles remained for this review. Results: A variety of probiotic strains used to reduce the incidence of NEC were identified, along with inconsistent times of initiation, number of colony forming units and length of treatment. The most commonly studied probiotic strains include Lactobacillus species, Bifidobacterium species, and Saccharomyces species. After detailed analysis, it appears that a combination of Bifidobacterium species and Lactobacillus species reduce the incidence of NEC from an 8% (Fernández-Carrocera et. al, 2013) reduction up to 100% reduction in the incidence of NEC (Braga, Pontes da Silva, Cabral de Lira, & Lima, 2011). These two species, when combined, were more successful when compared to Saccharomyces species or Lactobacillus species alone. Conclusion: Although there is positive support for the proactive use of probiotics for the reduction of the incidence of NEC in premature neonates, the inconsistencies between studies are a barrier for determination of a specific treatment recommendation. Although the combination of Bifidobacterium species and Lactobacillus species has been shown to have an impact on the reduction of NEC incidence, the research inconsistencies provide a barrier to generalizations for treatment. Additional research that focus on Bifidobactrium species in combination with Lactobacillus species is needed. Furthermore, the use of probiotics as a preventative treatment for NEC has not been thoroughly researched in extremely premature infant populations (gestation). Therefore, although the results are promising, further research is needed before this can be determined as a safe preventative method. The current questions remaining include: when prophylactic treatment should be initiated, how long prophylactic treatment should last, the number of colony forming units to be administered, and what is the long-term impact of probiotic administration on the normal gut flora, if any.
366

Molecular, somatic, and performance characteristics of broilers exhibiting woody breast myopathy, and the effects of dietary and challenge intervention strategies

Jia, Linan 10 December 2021 (has links)
Woody breast (WB) is a meat quality problem that has caused significant economic losses for the poultry industry. Ross × Ross 708 chicks were randomly assigned to a 3 (diet) × 2 (cocci challenge) × 2 (sex) factorial arrangement of treatments. The three diets included the control diet (corn-soybean meal basal diet), antibiotic diet (basal diet + 6.075 mg bacitracin /kg feed), and probiotic diet (basal diet + 2.2 × 108 CFU Bacillus subtilis PB6 /kg feed). Birds in the cocci challenge treatment group received 20 × the live cocci vaccine as an inoculum on d 14. Growth performance and WB score were measured to understand the effects of management factors (diet and coccidiosis) on broiler growth and WB development. Results indicated that dietary bacitracin and Eimeria spp. increased WB incidence, body weight, and growth rate. Bacillus subtilis increased WB incidence in male broilers without affecting body weight and growth rate. The association of the development of the internal organs and skeletal muscle with WB myopathy incidence in broilers were evaluated. The digestion organs (proventriculus and gizzard) and the skeletal muscles (drumsticks, thighs, and wings) developed at lower rates in birds with WB. In addition, the effects of the dietary and challenge interventions on the gut microbiota diversity and composition associated with WB in broilers were investigated. Results showed that cocci challenge altered gut microbiota composition and various biosynthetic pathways. Maintaining a healthy gut ecosystem is critical for the reduction of WB incidence in broilers. Gene expression related to oxidative stress, gut barrier function, and inflammation in jejunal mucus was investigated. Results showed that WB is related to decreased mucin expression (MUC6) in mucus, indicating a correlation between WB incidence and a lessening of the secretion of gel-forming mucin. In conclusion, dietary antibiotic and probiotic and challenge intervention strategies increased WB incidence, and microbiota composition and gut health gene expression differed in broilers exhibiting WB myopathy.
367

THE AGING MUCOSAL IMMUNE SYSTEM IN THE INTERLEUKIN-10-DEFICIENT MOUSE

Etling, Michele R. 13 July 2007 (has links)
No description available.
368

The Effects of Bifidobacterium Longum NCC3001 on AH Neuron Excitability and Slow Wave Activity of the Mouse Intestine

Khoshdel, Amir 04 1900 (has links)
<p>The small intestine holds an intrinsic ability to digest and absorb nutrients from the food we intake without intervention from the central nervous system. This ability is made possible by the population of cells that inhabit the gut, particularly interstitial cells of Cajal of the myenteric plexus and sensory primary intrinsic neurons (AH cells), which ultimately influence muscle function and motility. The AH cells are the first neurons in the hierarchy of sensory neurons in the gut and are therefore a perfect candidate to test the effects of <em>Bifidobacterium longum</em> NCC3001 supernatant since in a physiological setting the metabolites secreted by this bacterium can interact with the AH cells directly or indirectly through absorption by the mucosa.</p> <p>The probiotic <em>Bifidobacterium</em> <em>longum</em> NCC3001 has been shown to normalize anxiety-like behaviour and hippocampal brain derived neurotropic factor (BDNF) levels in mice infected with <em>Trichuris</em> <em>muris </em>in a model of infectious colitis. Utilizing a chronic model of colitis, a study was conducted to decipher whether or not the anxiolytic effects of <em>Bifidobacterium longum</em> NCC3001 involved the vagus. My specific objective in this study was to find evidence for interaction between <em>B.longum</em> NCC3001 and myenteric neurons as a potential route for <em>B.longum</em> NCC3001 to influence CNS function. We assessed a cell’s electro-responsiveness through spike discharge, which is the number of action potentials elicited in response to a supra-threshold depolarizing current injection.</p> <p>The electro-responsiveness of neurons perfused with <em>B. longum</em> NCC3001 supernatant (conditioned medium; n = 4) was significantly reduced compared to the control group (those perfused with Krebs solution; n = 5; <em>P</em> = 0.016). The electro-responsiveness of neurons perfused with the conditioned medium was also significantly lower than that of neurons perfused with unconditioned group (MRS growth medium alone) group (n = 4; <em>P</em> = 0.029). In comparing the excitabilities of the neurons in the control group with that of the control media group, there was no statistical difference (<em>P</em> = 0.29).</p> <p>In subsequent studies, the objective was to identify the AH cells and to determine the effect of <em>B. longum</em> NCC3001 conditioned medium on this population of cells. The electro-responsiveness as measured through spike discharge of AH cells perfused with the conditioned medium (n = 5) was significantly reduced compared to neurons perfused with the unconditioned medium (n = 5; <em>P</em> = 0.02). Sensory neurons perfused with the conditioned medium (n = 9) exhibited a significant reduction in their instantaneous input resistances compared to neurons perfused with the unconditioned medium (n = 8; <em>P </em>= 0.01). There was also a significant reduction in the time-dependent input resistance of neurons perfused with the conditioned medium (n = 9) compared to neurons perfused with the unconditioned medium (n = 8; <em>P </em>= 0.02). In addition, perfusion of the conditioned medium over sensory neurons (n = 9) significantly reduced the magnitude of the hyperpolarization-activated cationic current (<em>I</em><sub>h</sub>) compared to neurons perfused with the unconditioned medium (n = 8; <em>P</em> = 0.0003). Furthermore, there was also a significant reduction in the action potential half width duration of myenteric sensory neurons perfused with conditioned medium (n = 5) compared to that exhibited by neurons perfused with the unconditioned medium (n = 5; <em>P</em> = 0.008).</p> <p>In later experiments, we wanted to gain a more comprehensive understanding of the effect of this bacterium on the gut so we evaluated its effects on the gut musculature. Upon full immersion, the supernatant of <em>Bifidobacterium longum</em> NCC3001 (conditioned medium) caused an initial depolarization of the circular smooth muscle cell. This depolarization continued until the slow wave oscillations in these cells ceased and membrane potential would plateau. Several minutes after this plateau, the slow wave oscillations reappeared and the cell was significantly hyperpolarized relative to the conditions before conditioned medium was added. The resting membrane potential of circular smooth muscle cells in Krebs solution was -54.3 mV and -70.3 mV approximately two minutes after full immersion by the supernatant when the cell was hyperpolarized and a stable recorded was achieved (n = 7; <em>P</em> = 0.02). The average time of onset of depolarization was 18.6 s and the average change in membrane potential (depolarization) from onset of effect to its plateau was 14.0 mV (n = 7). Occasionally, the addition of the conditioned medium only caused an immediate but slight depolarization (n = 3) and in other cases caused only a hyperpolarization of the cell (n = 3) with no significant changes in any slow wave characteristics in either case. Furthermore, any cells that exhibited the waxing and waning of the slow wave lost this pattern upon the addition of the conditioned medium (n = 10).</p> <p>In attempts to understand the role of neurotransmission in this system, we conducted several experiments whereby carbachol (acetylcholine agonist) and L-NNA (nitric oxide synthase inhibitor) were administered to the muscle. Prior to the addition of 1μM carbachol or 2e<sup>-4 </sup>M L-NNA, we would only observe the pacemaker slow wave associated with the interstitial cells of Cajal of the myenteric plexus during the perfusion of Krebs solution. Upon the addition of carbachol (n = 3) or L-NNA (n = 4), we would observe a second slower frequency pattern appear, referred to as a waxing and waning pattern.</p> / Master of Science (MSc)
369

HOPX EXPRESSION IN IMMUNE REGULATORY B CELL REGULATE INTESTINAL INFLAMMATION

Thayaparana, Nalayini 04 1900 (has links)
<p>Inflammatory bowel disease (IBD) is chronic, relapsing, intestinal inflammation characterized by periods of remission and exacerbation. Pathogenesis of IBD is a complex process and the exact aetiology is unclear yet. Studies have provided evidences that IBD is a result of a genetic predisposition that leads to a mucosal immune regulatory cell defect, barrier defects, and susceptibility to environmental triggers like luminal bacteria and specific antigens. Innate and adaptive immune responses to commensal bacteria are balanced by the multiple regulatory cells like T regs and B regs. Monoclonal-antibody-based therapies have been identified for the treatment of IBD but, they have side effects and the efficacy is not stable. Hence, great expectations lie towards finding a successful cure for IBD.</p> <p>Recent studies have proved the involvement of several different genes in the pathogenesis of IBD and there expressions were highly reduced in IBD. Homeodomain only protein- Hopx is a nuclear protein required to modulate heart growth and function. Expression of Hopx has been reported in various types of normal tissues but not in malignant tissues. Recent study on Hopx revealed that Hopx is needed for the function of regulatory T cells induced by DCs. However the correlation between Hopx gene and IBD remains unanswered. In this study, we examined the role of Hopx expressing regulatory B cell in IBD.</p> <p>The aim of this study is to investigate whether the expression of Hopx in regulatory B cell play a key role in suppressing colitis in murine model.</p> <p>The expression of Hopx was studied using cellular and molecular techniques including flowcytometry, immunohistochemistry, western blotting and real time RT-PCR.</p> <p>As a first step, we investigated the Hopx expression in colitis and control murine model. After we found the possible involvement of Hopx gene in regulating intestinal inflammation, we further our study to investigate whether Hopx is expressed by regulatory B cell and function together to inhibit intestinal inflammation. After establishing Hopx and B regs association, we used probiotics to modulate Hopx expression in regulatory B cells in order to prevent/reduce intestinal inflammation. Finally we elucidate the importance of Hopx expression by injecting neutralizing anti-Hopx antibody to block Hopx.</p> <p>Together, studies on human intestinal tissue and murine model revealed that Hopx expression is suppressed during inflammation condition. Probiotic administration helps to increase Hopx expressing Breg cell thereby, prevent IBD. Hopx deficient group expressed high frequency of proinflammatory cytokines and reduced immune regulatory cells. This particular study proposes that the down regulation of Hopx contributes to the development of intestinal inflammation.</p> / Master of Health Sciences (MSc)
370

Probiotics as a Treatment for Increased Nighttime Activity in Rhesus Macaques (Macaca mulatta) Displaying Self-Injurious Behavior

Stanwicks, Lauren L 07 November 2016 (has links) (PDF)
Self-injurious behavior (SIB) is a behavioral pathology seen in a small percentage of humans and non-human primates. In one previous study, macaques with SIB had more sleep disruption than controls, but observations were limited. Two studies were conducted: a baseline study to investigate nighttime activity in rhesus macaques (Macaca mulatta) displaying SIB and controls, and a probiotic study to assess probiotic Bifidobacterium infantis 35624 for high nighttime activity. Subjects were 13 rhesus macaques, 5 with SIB (3 females; 1 SIB). Videocapture of Nighttime Activity (VNRA) was developed to record in complete darkness. IR-receptive webcams were connected to a laptop running ISPYCONNECT, software which recorded movement. Subjects were observed during the entire lights-off period (8pm-7am). Measures included total movement time (TMT), movement in hour 1 (HR1) and hour 11 (HR11), and number of videos. In the baseline, SIB subjects had higher TMT (pBifidobacterium infantis 35624 had no effect on sleep disruption, and also that increased nighttime activity seems to be a persistent characteristic of SIB subjects. It is unknown if increased nighttime activity affects SIB subjects; it may result in elevated SIB, or the SIB pathology could result in sleep disruption.

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