CONTROLLING INFECTIOUS DISEASE IN LABORATORY ZEBRAFISH (DANIO RERIO)

Mycobacteriosis is a bacterial disease caused by Mycobacterium spp. that is common in captive, wild and research fish species. The overall goal of this thesis was to investigate mycobacteriosis in laboratory zebrafish in order to increase our understanding of this disease with the intention of influencing control and management practices. First, disease prevention through embryo disinfection was investigated. The effectiveness of several disinfectants were evaluated and povidone-iodine was identified as an effective disinfectant in vitro, it was then evaluated in vivo and showed minimal effects embryo health. Second, the potential of antibiotic treatment against mycobacteriosis in zebrafish was evaluated in vitro where tigecycline and clarithromycin were identified as key drug candidates. The tolerance and efficacy of both antibiotics were tested in vivo in adult zebrafish; where treatments were well tolerated and resulted in a decreased severity in establish mycobacterial infections. Last, natural modes of transmission were examined. Transmission between tank biofilms and zebrafish was demonstrated and the role mycobacterial biofilms play as both a reservoir for and source of Mycobacterium spp. in zebrafish tanks was identified. Finally, the role that live feeds play as a vector of mycobacterial transmission to zebrafish was tested and common zebrafish feeds are able to transmit Mycobacterium spp. to zebrafish. Altogether, these studies contribute to our current knowledge of mycobacterial infections in laboratory zebrafish and inform management. These results are also of use to other fish species as well

Perturbing the developing skull: using laser ablation to investigate the robustness of the infraorbital bones in zebrafish (Danio rerio)

Publisher's Version/PDFBackground: The development of the craniofacial skeleton from embryonic mesenchyme is a complex process that is not yet completely understood, particularly for intramembranous bones. This study investigates the development of the neural crest derived infraorbital (IO) bones of the zebrafish (Danio rerio) skull. Located under the orbit, the IO bones ossify in a set sequence and are closely associated with the lateral line system. We conducted skeletogenic condensation and neuromast laser ablation experiments followed by shape analyses in order to investigate the relationship between a developing IO bone and the formation of the IO series as well as to investigate the highly debated inductive potential of neuromasts for IO ossification. Results: We demonstrate that when skeletogenic condensations recover from laser ablation, the resulting bone differs in shape compared to controls. Interestingly, neighbouring IO bones in the bone series are unaffected. In addition, we show that the amount of canal wall mineralization is significantly decreased following neuromast laser ablation at juvenile and larval stages. Conclusions: These results highlight the developmental robustness of the IO bones and provide direct evidence that canal neuromasts play a role in canal wall development in the head. Furthermore, we provide evidence that the IO bones may be two distinct developmental modules. The mechanisms underlying developmental robustness are rarely investigated and are important to increase our understanding of evolutionary developmental biology of the vertebrate skull

Positron emission tomographic imaging of Copper 64- and Gallium 68-labeled chelator conjugates of the somatostatin agonist Tyr3-octreotate

The bifunctional chelator and radiometal have been shown to have a direct effect on the pharmacokinetics of somatostatin receptor (SSTR)-targeted imaging agents. We evaluated three Y3-TATE analogues conjugated to NOTA-based chelators for radiolabeling with 64 Cu and 68 Ga for small-animal positron emission tomographic/computed tomograhic (PET/CT) imaging. Two commercially available NOTA analogues, p-SCN-Bn-NOTA and NODAGA, were evaluated. The p-SCN-Bn-NOTA analogues were conjugated to Y3- TATE through β-Ala and PEG 8 linkages. The NODAGA chelator was directly conjugated to Y3-TATE. The analogues labeled with 64 Cu or 68 Ga were analyzed in vitro for binding affinity and internalization and in vivo by PET/CT imaging, biodistribution, and Cerenkov imaging ( 68 Ga analogues). We evaluated the effects of the radiometals, chelators, and linkers on the performance of the SSTR subtype 2–targeted imaging agents and also compared them to a previously reported agent, 64 Cu-CB-TE2A-Y3-TATE. We found that the method of conjugation, particularly the length of the linkage between the chelator and the peptide, significantly impacted tumor and nontarget tissue uptake and clearance. Among the 64 Cu- and 68 Ga-labeled NOTA analogues, NODAGA-Y3-TATE had the most optimal in vivo behavior and was comparable to 64 Cu-CB-TE2A-Y3-TATE. An advantage of NODAGA-Y3-TATE is that it allows labeling with 64 Cu and 68 Ga, providing a versatile PET probe for imaging SSTr subtype 2-positive tumors

Intradermal Administration of Fractional Doses of Inactivated Poliovirus Vaccine: A Dose-Sparing Option for Polio Immunization.

A fractional dose of inactivated poliovirus vaccine (fIPV) administered by the intradermal route delivers one fifth of the full vaccine dose administered by the intramuscular route and offers a potential dose-sparing strategy to stretch the limited global IPV supply while further improving population immunity. Multiple studies have assessed immunogenicity of intradermal fIPV compared with the full intramuscular dose and demonstrated encouraging results. Novel intradermal devices, including intradermal adapters and disposable-syringe jet injectors, have also been developed and evaluated as alternatives to traditional Bacillus Calmette-Guérin needles and syringes for the administration of fIPV. Initial experience in India, Pakistan, and Sri Lanka suggests that it is operationally feasible to implement fIPV vaccination on a large scale. Given the available scientific data and operational feasibility shown in early-adopter countries, countries are encouraged to consider introducing a fIPV strategy into their routine immunization and supplementary immunization activities

Subject preferences of fifth-grade children.

Thesis (Ed.M.)--Boston University N.B.:Pages 155 and 309 are missing from original thesis

Cord blood versus age 5 mononuclear cell proliferation on IgE and asthma

Abstract Background Fetal immune responses following exposure of mothers to allergens during pregnancy may influence the subsequent risk of childhood asthma. However, the association of allergen-induced cord blood mononuclear cell (CBMC) proliferation and cytokine production with later allergic immune responses and asthma has been controversial. Our objective was to compare indoor allergen-induced CBMC with age 5 peripheral blood mononuclear cell (PBMC) proliferation and determine which may be associated with age 5 allergic immune responses and asthma in an inner city cohort. Methods As part of an ongoing cohort study of the Columbia Center for Children's Environmental Health (CCCEH), CBMCs and age 5 PBMCs were cultured with cockroach, mouse, and dust mite protein extracts. CBMC proliferation and cytokine (IL-5 and IFN-γ) responses, and age 5 PBMC proliferation responses, were compared to anti-cockroach, anti-mouse, and anti-dust mite IgE levels, wheeze, cough, eczema and asthma. Results Correlations between CBMC and age 5 PBMC proliferation in response to cockroach, mouse, and dust mite antigens were nonsignificant. Cockroach-, mouse-, and dust mite-induced CBMC proliferation and cytokine responses were not associated with allergen-specific IgE at ages 2, 3, and 5, or with asthma and eczema at age 5. However, after adjusting for potential confounders, age 5 cockroach-induced PBMC proliferation was associated with anti-cockroach IgE, total IgE, and asthma (p < 0.05). Conclusion In contrast to allergen-induced CBMC proliferation, age 5 cockroach-induced PBMC proliferation was associated with age 5 specific and total IgE, and asthma, in an inner-city cohort where cockroach allergens are prevalent and exposure can be high

Video Analysis of Newborn Resuscitations After Simulation-Based Helping Babies Breathe Training

Background Simulation-based Helping Babies Breathe (HBB) training is currently rolled-out in around 80 low-income countries with various results. Method Workflow was analyzed in 76 video-recorded newborn resuscitations performed by regularly HBB-trained nurse-midwives over 3 years in rural Tanzania. Results Actual newborn resuscitation practice deviated from HBB intention/guideline: most newborns underwent prolonged suction and stimulation before ventilation; ventilation was delayed and frequently interrupted. Nurse-midwives often worked together. Conclusions There is a gap between training intention and clinical practice. HBB trainings should focus more on urgency, ventilation skills, and team training. Combining clinical debriefing with HBB simulations could facilitate continuous learning and application.publishedVersio

Video Analysis of Newborn Resuscitations After Simulation-Based Helping Babies Breathe Training

Background: Simulation-based Helping Babies Breathe (HBB) training is currently rolled-out in around 80 low-income countries with various results. Method: Workflow was analyzed in 76 video-recorded newborn resuscitations performed by regularly HBB-trained nurse-midwives over 3 years in rural Tanzania. Results: Actual newborn resuscitation practice deviated from HBB intention/guideline: most newborns underwent prolonged suction and stimulation before ventilation; ventilation was delayed and frequently interrupted. Nurse-midwives often worked together. Conclusions:There is a gap between training intention and clinical practice. HBB trainings should focus more on urgency, ventilation skills, and team training. Combining clinical debriefing with HBB simulations could facilitate continuous learning and applicatio