Capacity to report on mortality attributable to chronic hepatitis B and C infections by Member States: An exercise to monitor progress towards viral hepatitis elimination.

Viral hepatitis is globally leading causes of death, and 96% of these are due to hepatitis B and C (HBV/HCV) late outcomes. The first Global Health Sector Strategy (GHSS) aims to reduce by 65% the mortality associated with HBV/HCV, and an indicator (C10) is proposed to monitor progress. Data on viral hepatitis and liver-related mortality are required, and different methods of estimation can be used, depending on availability and quality of sources. We aimed to understand the current situation and practicality of calculating C10, accessing available sources to estimate initial figure for Europe. We listed and compiled regional and national data sources reporting deaths from HCC, cirrhosis and chronic liver disease (CLD) and available estimates of attributable fraction. We critically appraised quality of data, highlighting gaps in current data and estimated mortality attributable to HBV and HCV, for 31 EU/EEA countries from 2010 to 2015. Mortality data are available for 30/31 countries. Quality varies but 60% of national sources report with specificity as required by WHO indicator. Attributable fraction is only available through the literature search. We estimated C10 for 87.6% country-years. Deaths attributable to HBV/HCV for this period and region were 292 600, while HCV deaths were three times higher. Incomplete data for 2015 prevented calculation of time trends. Regional sources are outdated for monitoring C10, but national sources are capable of reporting mortality data. Sources for attributable fraction are sparse, outdated and much needed. We recommend improvement of death registration allowing measuring this indicator. Studies measuring attributable fraction on national and subnational levels are crucial.

Mutations in osteoprotegerin account for the CCAL1 locus in calcium pyrophosphate deposition disease.

OBJECTIVE: Mutations on chromosomes 5p (CCAL2) and 8q (CCAL1) have been linked to familial forms of calcium pyrophosphate deposition disease (CPDD). Mutations in the ANKH gene account for CCAL2, but the identity of CCAL1 has been elusive. Recently, a single Dutch kindred with a mutation in the Tumor Necrosis Factor Receptor Super Family member 11B (TNFRSF11B) gene coding for osteoprotegerin (OPG) was described as a gain-of-function mutation. Affected family members had premature generalized osteoarthritis (PGOA) and CPDD. As the TNFRSF11B gene is on 8q, we sought additional evidence that TNFRSF11B was CCAL1, and investigated potential disease mechanisms. DESIGN: DNA from two novel PGOA/CPDD families was screened for sequence variants in the TNFRSF11B gene. Mutations were verified by genotype analysis of affected and unaffected family members. We also investigated effects of normal and mutant OPG on regulators of CPP crystal formation in porcine cartilage. RESULTS: The identical TNFRSF11B mutation described in the Dutch family was present in two novel PGOA/CPDD families. ANKH was normal in affected patient fibroblasts. Exogenous OPG did not alter ANKH mRNA or protein levels, affect translocation of ANKH to the membrane, nor increase [pyrophosphate (PPi)] or other key regulators of CPDD. CONCLUSION: We have firmly established the identity of CCAL1 as TNFRSF11B (OPG). Our findings suggest that this mutation produces disease in an ANKH-independent manner via novel mechanisms not primarily targeting cartilage. This work rationalizes further investigation of OPG pathway components as potential druggable targets for CPDD.

Time, place, and people: composition of the EPIET Alumni Network and its contribution to the European public health resource in 2013.

The EPIET Alumni Network (EAN) is an association of professionals who have completed field epidemiology or public health microbiology training programmes in the European Union. In 2013, we conducted a survey of EAN members to investigate this network's role within European public health. We distributed an online questionnaire to members registered at the time, collecting data on demographics, professional background, and attitudes towards EAN. Out of 362 registered members, 189 (52%) responded; 97% were from Europe; 65% were female. Their mean age was 39 years. The highest academic qualification was PhD for 44% and Master's degree for 55%. The majority (60%) worked in public health institutes. They were especially satisfied with having access to job offers and professional networking via EAN, but requested more learning opportunities and knowledge-sharing between members. EAN is a unique platform where highly skilled professionals can connect to control infectious diseases locally and internationally. Having a network of professionals that know each other, speak the same 'language', and can easily access each other's expertise, represents an important resource for European and global public health, which should be nurtured by encouraging more collaborations devoted to professional development.

Hormonal contraceptive use before and after conception in relation to preterm birth and small for gestational age: an observational cohort study.

OBJECTIVE: To evaluate whether hormonal contraceptives, used before or in early pregnancy, confer increased risk of preterm birth or reduced fetal growth. DESIGN: Population-based cohort study conducted by the Norwegian Institute of Public Health (Mother and Child Cohort Study, 1998-2008) with linkage to the Norwegian Prescription Registry and to the Medical Birth Registry of Norway. SETTING: Norway. POPULATION: Of the 48,615 pregnancies meeting study inclusion criteria, 44,734 pregnancies were included in the complete case analysis. METHODS: We characterised hormonal contraception by type (combination oral, progestin-only oral, vaginal ring, transdermal, and injectable) and specific progestin component. We used generalised estimating equations to estimate the odds of adverse outcome according to formulation used. Several sensitivity analyses were conducted. MAIN OUTCOME MEASURES: Preterm birth, small for gestational age. RESULTS: We observed a positive association between use of a combination oral contraceptive and preterm birth for all exposure periods (e.g. adjusted odds ratio 1.21, 95% confidence interval 1.04-1.41 for last use 12 to >4 months before conception); combination contraceptives containing the progestin norethisterone were consistently related to risk. Other types of hormonal contraception were generally not associated with preterm birth; none were related to small for gestational age. Observed associations were robust to sensitivity analyses. CONCLUSION: Hormonally active agents may exert dose-, agent-, and timing-specific effects on growth and development. We found that the particular progestin component is important when assessing the potential for adverse effects among former users of hormonal contraceptives.

Mathematical model of a gene regulatory network reconciles effects of genetic perturbations on hematopoietic stem cell emergence.

Interlinked gene regulatory networks (GRNs) are vital for the spatial and temporal control of gene expression during development. The hematopoietic transcription factors (TFs) Scl, Gata2 and Fli1 form one such densely connected GRN which acts as a master regulator of embryonic hematopoiesis. This triad has been shown to direct the specification of the hemogenic endothelium and emergence of hematopoietic stem cells (HSCs) in response to Notch1 and Bmp4-Smad signaling. Here we employ previously published data to construct a mathematical model of this GRN network and use this model to systematically investigate the network dynamical properties. Our model uses a statistical-thermodynamic framework to describe the combinatorial regulation of gene expression and reconciles, mechanistically, several previously published but unexplained results from different genetic perturbation experiments. In particular, our results demonstrate how the interactions of Runx1, an essential hematopoietic TF, with components of the Bmp4 signaling pathway allow it to affect triad activation and acts as a key regulator of HSC emergence. We also explain why heterozygous deletion of this essential TF, Runx1, speeds up the network dynamics leading to accelerated HSC emergence. Taken together our results demonstrate that the triad, a master-level controller of definitive hematopoiesis, is an irreversible bistable switch whose dynamical properties are modulated by Runx1 and components of the Bmp4 signaling pathway.

Maternal hormonal contraceptive use and offspring overweight or obesity.

BACKGROUND/OBJECTIVES: Experiments in animal models have shown a positive association between in utero exposure to pharmacologic sex hormones and offspring obesity. The developmental effects of such hormones on human obesity are unknown. SUBJECTS/METHODS: Using data from a large, prospective pregnancy cohort study (n=19 652), with linkage to a national prescription registry, we evaluated the association between use of hormonal contraceptives before and after conception (defined from dispensed prescription data and characterized by last date of use relative to conception, 12 to >4 months before (n=3392), 4 to >1 months before (n=2541), 1 to >0 months before (n=2997) and 0-12 weeks after (n=567)) in relation to offspring overweight or obesity at age 3 years. RESULTS: We observed a weak, inverse association between early pregnancy use of a combination oral contraceptive and offspring overweight or obesity at age 3 (adjusted odds ratio (OR): 0.75, 95% confidence interval (CI): 0.53, 1.08) and a positive, but imprecise, association with use of a progestin-only oral contraceptive in early pregnancy (adjusted OR: 1.26, 95% CI: 0.79, 2.02). In general, no association was observed between the use of a hormonal contraceptive before conception and offspring overweight or obesity. A sensitivity analysis comparing combination oral contraceptive users in early pregnancy to other unplanned pregnancies without hormonal contraceptive use further strengthened the inverse association (adjusted OR: 0.70, 95% CI: 0.48, 1.02). Other sensitivity analyses were conducted to evaluate the robustness of the associations observed given varying assumptions. CONCLUSIONS: Pharmacologic sex hormones in early pregnancy may be inversely or positively associated with offspring overweight or obesity at age 3, depending on the specific formulation used. The present study provides support for the potential for environmental sources of hormonally active agents to exert developmental effects.

Recent outbreaks of infectious syphilis, United Kingdom, January 2012 to April 2014.

Six outbreaks of infectious syphilis in the United Kingdom, ongoing since 2012, have been investigated among men who have sex with men (MSM) and heterosexual men and women aged under 25 years. Interventions included case finding and raising awareness among healthcare professionals and the public. Targeting at-risk populations was complicated as many sexual encounters involved anonymous partners. Outbreaks among MSM were influenced by the use of geospatial real-time networking applications that allow users to locate other MSM within close proximity.

In ovo administration of the Marek's disease vaccine in conjunction with 25-hydroxyvitamin D3 and its subsequent effects on the performance and immunity-related characteristics of Ross 708 broiler hatchlings1,2,3.

The combined effects of the in ovo injection of commercial Marek's disease vaccine (MDV) and various levels of 25-hydroxyvitamin D3 (25OHD3) on the hatch variables, immunological measurements, and gene expression of Ross 708 hatchling broilers were investigated. A total of 5 in ovo injection treatments that were applied at 18 d of incubation (doi) included: 1) noninjected (control); or a 50 µL solution volume of 2) MDV alone; or MDV combined with 3) 0.6 µg of 25OHD3; 4) 1.2 µg of 25OHD3; or 5) 2.4 µg of 25OHD3. At hatch, hatchability of set and live embryonated eggs, hatchling body weight, hatch residue analysis, serum IgY and alpha-1 acid glycoprotein (AGP) concentrations, and the expression of genes related to immunity (INFα, INFß, INFγ, TLR-3, and TLR-21) and vitamin D3 activity (1 α-hydroxylase, 24 hydroxylase, and vitamin D receptor) were determined. No significant treatment differences were observed for hatchability of set and live embryonated eggs, or for serum IgY and AGP concentrations. However, hatchling body weight was higher when MDV was combined with either 1.2 or 2.4 µg of 25OHD3 than when MDV was provided alone or in combination with 0.6 µg of 25OHD3. Also, in comparison to the noninjected treatment group, the expression of the genes for 1 α-hydroxylase and 24 hydroxylase was improved when MDV was combined with either 1.2 or 2.4 µg of 25OHD3. Lastly, expression of the genes linked to viral detection (TLR-3) and antibody production (INF-ß) was increased in those treatments that contained any level of 25OHD3. These results indicate that in comparison to controls, the effects of MDV were observed to be greater on hatchling BW and splenic gene expression when it was administered in combination with the 1.2 or 2.4 µg doses of 25OHD3. Further research is needed to determine the posthatch effects of the administration of various levels of 25OHD3 in combination with MDV.

Risk exposures for human ornithosis in a poultry processing plant modified by use of personal protective equipment: an analytical outbreak study.

Ornithosis outbreaks in poultry processing plants are well-described, but evidence for preventive measures is currently lacking. This study describes a case-control study into an outbreak of ornithosis at a poultry processing plant in the East of England, identified following three employees being admitted to hospital. Workers at the affected plant were recruited via their employer, with exposures assessed using a self-completed questionnaire. Cases were ascertained using serological methods or direct antigen detection in sputum. 63/225 (28%) staff participated, with 10% of participants showing evidence of recent infection. Exposure to the killing/defeathering and automated evisceration areas, and contact with viscera or blood were the main risk factors for infection. Personal protective equipment (goggles and FFP3 masks) reduced the effect of exposure to risk areas and to self-contamination with potentially infectious material. Our study provides some evidence of effectiveness for respiratory protective equipment in poultry processing plants where there is a known and current risk of ornithosis. Further studies are required to confirm this tentative finding, but in the meantime respiratory protective equipment is recommended as a precautionary measure in plants where outbreaks of ornithosis occur.

Estimating the prevalence of infections in vector populations using pools of samples.

Several statistical methods have been proposed for estimating the infection prevalence based on pooled samples, but these methods generally presume the application of perfect diagnostic tests, which in practice do not exist. To optimize prevalence estimation based on pooled samples, currently available and new statistical models were described and compared. Three groups were tested: (a) Frequentist models, (b) Monte Carlo Markov-Chain (MCMC) Bayesian models, and (c) Exact Bayesian Computation (EBC) models. Simulated data allowed the comparison of the models, including testing the performance under complex situations such as imperfect tests with a sensitivity varying according to the pool weight. In addition, all models were applied to data derived from the literature, to demonstrate the influence of the model on real-prevalence estimates. All models were implemented in the freely available R and OpenBUGS software and are presented in Appendix S1. Bayesian models can flexibly take into account the imperfect sensitivity and specificity of the diagnostic test (as well as the influence of pool-related or external variables) and are therefore the method of choice for calculating population prevalence based on pooled samples. However, when using such complex models, very precise information on test characteristics is needed, which may in general not be available.

A retrospective audit of the timescales involved in the diagnosis and management of suspected Achilles tendon ruptures at a single National Health Service trust: A quality service improvement and redesign project.

Introduction: The Achilles tendon is the most frequently ruptured tendon. Prompt diagnosis of this injury ensures optimal management decisions are instituted early ensuring the best outcome and patient experience, at minimal cost to the United Kingdom National Health Service. Despite this, regional and national variations to diagnosis and management exist, with anecdotal evidence of inefficiencies in the local patient pathway. To explore this further, a retrospective departmental audit of timescales from presentation to ultrasound diagnosis and definitive treatment decision was undertaken. Methods: All suspected Achilles tendon ruptures in 2018 were identified through electronic and written patient records, and information on timescales involved in the diagnosis and management of each compiled. Descriptive statistics were used to map each step of the pathway and timescales involved, with performance assessed against local departmental standards and the Swansea Morriston Achilles Rupture Treatment (SMART) protocol. Results: In total, 119 patients were identified, of which 113 received an ultrasound examination. Local departmental standards were met in the majority of cases, with 78% (n = 88) diagnosed by ultrasound within one week of the request and 83% (n = 91) given a treatment decision within two weeks of presentation. However, this was suboptimal when compared with timeframes utilised for developing the SMART protocol, with only 7% (n = 8) scanned within 48 hours of presentation. Conclusions: Key areas of the patient pathway were identified for quality service improvement and redesign, with multidisciplinary discussion resulting in the development of a revised patient pathway which expedites diagnosis and treatment for these injuries.

Field evaluation of the accuracy of vaccine deposition by two different commercially available in ovo injection systems.

The location of injection and vaccine deposition in ovo is known to be critical to the efficacy of Marek's disease (MD) vaccine protection against MD viral challenge. Vaccine deposition into the amniotic sac or a s.c. or i.m. site of the embryo is required for MD vaccine efficacy. Vaccine deposition into the air cell or allantoic fluid results in chicks that are not adequately protected against subsequent MD viral challenge. A study was conducted in 2 commercial broiler hatcheries to evaluate the ability of 2 in ovo injection systems, the Embrex Inovoject system (Pfizer Poultry Health, Research Triangle Park, NC) and the Intelliject system (Avitech, Salisbury, MD; distributed by Merial Ltd., Gainesville, GA) to deliver a vaccine approved for use in ovo accurately and properly. A standard MD vaccine diluent mixed with a protein-staining dye was delivered through each machine to simulate in ovo vaccination. The location of the dye within the egg determined whether the vaccine was delivered correctly. Each egg was also evaluated for normal embryo development (normal eggs). Correct vaccine delivery included eggs in which the vaccine was injected into the amniotic sac or into s.c. or i.m. regions of the embryo. Incorrect vaccine delivery was defined as delivery into the air cell; allantoic sac; any combinations including air cell or allantois; the abdominal, cranial, orbital, or thoracic cavities of the embryo; or no vaccine delivery at all. In hatchery 1 (Chick Master, Newton, MS) 1,171 normal eggs were processed through the Inovoject system and 1,138 eggs were processed by the Intelliject system. The Inovoject system correctly vaccinated 94.62% of the normal eggs as compared with 61.16% delivery accuracy of normal eggs with the Intelliject system. In hatchery 2 (Jamesway Super J, Magee, MS) 926 normal eggs were processed by the Inovoject system and 910 normal eggs were processed by the Intelliject system. The Inovoject system correctly vaccinated 91.04% of the normal eggs, whereas the Intelliject system correctly vaccinated 71.98% of the normal eggs. The results of this study clearly demonstrate that the Inovoject system accurately delivered in ovo vaccine at a significantly higher rate than the Intelliject system.

Effects of administration of an in ovo coccidiosis vaccine at different embryonic ages on vaccine cycling and performance of broiler chickens,.

Use of a live coccidiosis vaccine has become an increasingly common method to control coccidiosis, especially in antibiotic-free broiler production. The Inovocox EM1 vaccine (EM1) is recommended for the vaccination of embryonated broiler hatching eggs between 18.0 and 19.0 d of incubation (doi). This allows for earlier acquisition of immunity to wild-type coccidia. However, it is unclear whether the difference in embryo age at the time of in ovo injection can influence the effect of the vaccine during grow-out as well as if the growth performance of broiler chickens is affected. Therefore, the objective of the study was to evaluate the effects of 2 injection ages (18.5 and 19.0 doi) and 3 injection types (noninjected, diluent, and vaccine) in a 3 × 2 factorial design, consisting of 10 replicates per treatment (60 treatment-replicate groups). There was a significant effect of injection age on BW at 0, 14, and 35 d after hatch, with a difference in the BW of birds belonging to the 18.5 and 19.0 doi groups up to day 35 after hatch. There was a significant effect of injection type on BW gain, feed intake, and FCR between 0 and 28 d after hatch. Between 0 and 35 d, FCR was lower in the vaccine-injected group in comparison with the noninjected and diluent control groups. Furthermore, total intestine coccidia and lesion indices were higher in the vaccine-18.5 treatment group in comparison with the diluent-18.5 treatment group at 28 d. In conclusion, hatchling weight was affected by injection age, and this subsequently affected growth performance. Furthermore, intestinal coccidia cycling peaked at 28 d, resulting in a reduction in growth performance through 28 d and subsequent compensatory growth by 35 d. There was no significant difference in coccidiosis cycling between the vaccine-18.5 and vaccine-19.0 doi treatment combination groups.

MED and PSACH COMP mutations affect chondrogenesis in chicken limb bud micromass cultures.

Mutations in cartilage oligomeric matrix protein (COMP) cause pseudoachondroplasia (PSACH) and multiple epiphyseal dysplasia (MED). We studied the effects of over-expression of wild type and mutant COMP on early stages of chondrogenesis in chicken limb bud micromass cultures. Cells were transduced with RCAS virus harboring wild type or mutant (C328R, PSACH; T585R, MED) COMP cDNAs and cultured for 3, 4, and 5 days. The effect of COMP constructs on chondrogenesis was assessed by analyzing mRNA and protein expression of several COMP binding partners. Cell viability was assayed, and evaluation of apoptosis was performed by monitoring caspase 3 processing. Over-expression of COMP, and especially expression of COMP mutants, had a profound affect on the expression of syndecan 3 and tenascin C, early markers of chondrogenesis. Over-expression of COMP did not affect levels of type II collagen or matrilin-3; however, there were increases in type IX collagen expression and sulfated proteoglycan synthesis, particularly at day 5 of harvest. In contrast to cells over-expressing COMP, cells with mutant COMP showed reduction in type IX collagen expression and increased matrilin 3 expression. Finally, reduction in cell viability, and increased activity of caspase 3, at days 4 and 5, were observed in cultures expressing either wild type or mutant COMP. MED, and PSACH mutations, despite displaying phenotypic differences, demonstrated only subtle differences in their cellular viability and mRNA and protein expression of components of the extracellular matrix, including those that interact with COMP. These results suggest that COMP mutations, by disrupting normal interactions between COMP and its binding partners, significantly affect chondrogenesis.

Development of CD4+CD8+ thymocytes in RAG-deficient mice through a T cell receptor beta chain-independent pathway.

Antigen-binding diversity is generated by site-specific V(D)J recombination of the T cell receptor (TCR) and immunoglobulin loci in lymphocyte precursors. Coordinate expression of two structurally distinct recombinase activating genes, RAG-1 and RAG-2, is necessary for activation of site-specific V(D)J recombination. In mice bearing targeted disruptions of either the RAG-1 or RAG-2 genes, T and B lymphocyte development is arrested at the CD4-8- double negative (DN) thymocyte or B220+/CD43+ pro-B cell stage. Development of CD4+CD8+ double positive (DP) thymocytes is restored by expression of a functionally rearranged TCR beta transgene, suggesting that TCR beta expression is critical for this developmental transition. We have found that treatment of adult or newborn RAG-deficient mice with a single sublethal dose of gamma-irradiation rescues the DN to DP transition in early thymocytes, and this is accompanied by a dramatic increase in thymus cellularity. In contrast to the observed induction of thymocyte maturation, there was no phenotypic or functional evidence of coincident B lymphocyte development in irradiated RAG-deficient mice. Interestingly, maturation of DP thymocytes occurred without expression of TCR beta protein in the cytoplasm or on the cell surface. These results suggest an in vivo pathway for DP thymocyte development which is TCR beta chain independent.

Comparative field evaluations of in ovo applied technology.

Mass vaccination of poultry has advanced in recent years with field application of in ovo vaccination technologies in hatcheries worldwide. Working from a laboratory concept to a commercially available system within a matter of a decade, with subsequent full application to 90% of US broiler production a few years later, the commercial systems continue to be an area for study and continued understanding. Within the production setting, 2 methods to evaluate the types of equipment available for this technology were evaluated in this research. Utilizing a whole hatchery approach and paired testing in a field setting allowed for direct comparison of the 2 US-manufactured in ovo systems (Embrex Inovoject System and Intelliject). The results of the whole hatchery study showed an advantage for 1 system at d 18 and 19 transfer, with the Embrex Inovoject System showing as much as a 2.32% advantage in percentage of hatch. Paired testing showed a statistical difference in percentage of hatchability at d 18 of transfer favoring the Embrex Inovoject System but no difference at d 19 transfer. Differences in the 2 systems were additionally evaluated in terms of day of transfer and flock age.

Effects of stage of broiler embryo development on coccidiosis vaccine injection accuracy, and subsequent oocyst localization and hatchling quality.

Control of coccidiosis in broiler chickens continues to pose challenges to commercial poultry producers, especially in an era of increased consumer demand for antibiotic-free broiler production. As a result, coccidiosis vaccines are now commonly used in rotation programs to achieve effective coccidiosis control. Inovocox EM1 vaccine (EM1) is a coccidiosis vaccine that allows for earlier immune acquisition through oocyst cycling, which reduces the effects of wild-type coccidia. The EM1 vaccine is administered to embryonated broiler hatching eggs between 18 and 19 D of incubation (doi). In the U.S., commercial broiler hatcheries vaccinate embryonated eggs at either 18.5 or 19 doi. However, it is unclear whether a difference in embryo age at the time of in ovo injection can impact the actual site of vaccine delivery. In addition, it is unclear where oocysts eventually become localized within the embryo following the in ovo injection of EM1. Therefore, the objective of this study was to determine the effects of stage of embryonic development on the actual deposition site of the EM1 vaccine oocysts when they are in ovo injected and to subsequently investigate the movement and eventual location of EM1 oocysts after in ovo injection. Because all eggs were injected at the same time, a 12-h difference in set time was a means to derive 18.5 and 19.0 incubation age of injection (IAN) treatments. The experimental design was a 3 injection treatment (noninjected, diluent-injected, and vaccine-injected) × 2 IAN factorial. There was a significant main effect of IAN on site of vaccine oocysts delivery, and subsequent hatching chick quality. Qualitative histological evaluation revealed the oral uptake of vaccine oocysts through the amnion, with their subsequent presence in the gizzard and intestinal lumen by 24 to 36 h postinjection. In conclusion, physiological development influenced the site of injection, and oocysts imbibed along with the amniotic fluid in late stage broiler embryos are subsequently transported to the gastrointestinal tract.

Rescue of T cell-specific V(D)J recombination in SCID mice by DNA-damaging agents.

Assembly of antigen receptor V (variable), D (diversity), and J (joining) gene segments requires lymphocyte-specific genes and ubiquitous DNA repair activities. Severe combined immunodeficient (SCID) mice are defective in general double-strand (ds) DNA break repair and V(D)J coding joint formation, resulting in arrested lymphocyte development. A single treatment of newborn SCID mice with DNA-damaging agents restored functional, diverse, T cell receptor beta chain coding joints, as well as development and expansion of thymocytes expressing both CD4 and CD8 coreceptors, but did not promote B cell development. Thymic lymphoma developed in all mice treated with DNA-damaging agents, suggesting an interrelation between V(D)J recombination, dsDNA break repair, and lymphomagenesis.

Comparative effects of in ovo versus subcutaneous administration of the Marek's disease vaccine and pre-placement holding time on the intestinal villus to crypt ratios of Ross 708 broilers during early post-hatch development1,2,3.

Villus to crypt ratio (VCR) is used to quantify the microanatomical response of the intestine to various treatments. In early age chickens, comparative effects of the in ovo (i.o.) and s.c. methods of administration (moa) of the Marek's disease (MD) vaccine on 2 types of measurement of small intestinal VCR at 0 and 4 h post-hatch (poh) were investigated. The effects of moa and 4 and 18 h pre-placement holding times (pht) on the VCR measurements at 168 h (7 d) poh were also investigated. In the jejunum of the small intestine, a standard method for VCR determination, based on 10 villus and crypt length measurements, was utilized for the calculation of villus to crypt length ratio (VCLR). In that same region, a single histomorphometric determination of the crypt and total mucosa areas using image analysis software was also used. Subtraction of the crypt area from the total mucosa area provided the villus area, allowing for calculation of the villus to crypt area ratio (VCAR). Across 0, 4, and 18 h of poh bird age, the VCLR of birds that received an s.c. vaccination was higher in comparison to that of those that received an i.o. vaccination. The highest and lowest VCAR values were observed in the s.c. treatment at 0 h poh and in the i.o. treatment at 4 h poh, respectively. Furthermore, at 168 h poh, VCLR values in the 18 h pht and s.c. vaccination group were higher than those in the 4 h pht and s.c. vaccination or 18 h and i.o. vaccination groups. In conclusion, the effects of pht and MD vaccine moa on VCR were dependent on the use of either the VCLR or VCAR method of measurement. However, regardless of method, s.c. injection overall led to a higher VCR through 4 h poh in Ross 708 broilers, and the effects of moa on VCLR at 168 h were influenced by pht.