Evaluation of viral load and expression level of apoptotic genes in selected tissues of two hybrids of commercial broiler chickens challenged with infectious bronchitis virus: a comparative study

Background:Infectious bronchitis virus (IBV) causes severe economic losses worldwide. IBV has a broad tissue distribution with different viral loads in different tissues. Additionally, IBV can induce apoptosis in infected cells. Aims:The present study aimed to evaluate the role of the genetic background of chickens in viral load and the expression level of apoptotic genes in different tissues of two hybrids of commercial broiler chickens (Ross 308 and Cobb 500) challenged with IBV. Methods:Chickens at 21 days of age were nasally challenged with 200 μL of allantoic fluid containing 10⁴ EID₅₀/ml of Iranian variant-2-like IBV (IS/1494). The expression level of apoptotic genes (Fas, FasL, Bax, and Bcl-2) in the tracheal and renal tissues and the amount of viral load in the tracheal, renal, and cloacal swab samples were investigated two, five, and seven days after IBV infection by RT-qPCR assay. Results:The amount of viral load and apoptotic the expression level of apoptotic genes in the tracheal (two and five days after infection) and renal samples (seven days after infection) were significantly higher in the Ross challenged group than in the Cobb challenged group.Furthermore, no difference was observed in the cloaca viral load on sampling days. Conclusion:To our knowledge, this is the first report that evaluated the role of the chickens’ genetic background in the amount of viral load and the expression level of apoptotic genes against IBV. Further studies are needed to investigate the pathogenic characteristics of IBV in Ross 308 and Cobb 500 chickens.Key Words: Apoptosis, Broiler chickens, Infectious bronchitis virus, Viral load     

Skin testing to evaluate oculo-respiratory syndrome (ORS) associated with influenza vaccination during the 2000-2001 season

A syndrome of red eyes and respiratory symptoms was noted following receipt of influenza vaccine in Canada during the 2000-2001 influenza season. We conducted intra-dermal skin testing to determine if oculo-respiratory syndrome (ORS) was related to failure of the splitting process during vaccine manufacturing, if it was associated with a particular viral strain and to identify individuals at risk for subsequent ORS reaction. Skin testing with minute quantities of vaccine antigen induced ORS symptoms at a higher rate amongst persons previously affected by this syndrome compared to previously unaffected persons. Skin test reaction size or quality could not identify persons at risk of ORS. Skin testing could not identify a specific strain or the stage in the manufacturing process during which the trigger may have been introduced.     

Induction of specific cell‐mediated immune responses and protection in BALB/c mice by vaccination with outer membrane vesicles from a Brucella melitensis human isolate

Brucellosis is a worldwide bacterial zoonosis caused by Brucella spp. No approved vaccine is available for human use against the disease. In this study, outer membrane vesicles (OMVs) from a Brucella melitensis biovar 1 human isolate obtained in Iran were used to immunize BALB/c mice (n = 12) by 2 intramuscular injections with a 2‐week interval. Another group of 12 mice was used as non‐vaccinated controls. Two weeks after the last vaccination, six mice of each group were sacrificed, and proliferation and interferon gamma (IFNγ) production responses of their splenocytes were evaluated following in vitro stimulation with killed Brucella cells. The other mice were challenged with the virulent B. melitensis isolate. Two weeks later, mice were killed and spleens were cultured to determine the number of the challenge strain. The results showed proliferative response and IFNγ production of splenocytes from vaccinated mice (stimulation index: 2.18 ± 0.57, and 1519.35 ± 10.70 pg/mL, respectively) were significantly higher than those of control mice (stimulation index: 1.02 ± 0.02, and 210.01 ± 17.58 pg/mL, respectively). Numbers of the challenge strain in spleens of vaccinated mice were also significantly less than those in the controls with 1.6 units of protection. Our study revealed vaccination with OMVs of the B. melitensis isolate could induce specific immune responses and protection against infection in the mouse model suggesting their potential application for active immunization against brucellosis.     

Intravitreal bevacizumab alone or combined with 1 mg triamcinolone in diabetic macular edema: a randomized clinical trial

Purpose

To compare the results of intravitreal bevacizumab (IVB) injection alone or in combination with intravitreal 1 mg triamcinolone acetonide (IVT) in center-involved diabetic macular edema.

Methods

In this randomized clinical trial study, ninety-two eyes of 46 patients with bilateral center-involved diabetic macular edema and no previous treatment were included in the study. One eye of each patient was randomly assigned to 1.25 mg of IVB injection or combination of 1.25 IVB and 1 mg IVT. Evaluation of best-corrected visual acuity (BCVA), central macular thickness (CMT), intraocular pressure (IOP) and grading of lens opacity was conducted at baseline, and weeks 2, 4, 6, 8, 12 and 24 after treatment. Retreatment was performed at a 6-week interval whenever indicated based on CMT.

Results

Between the groups, BCVA changes were not statistically different until 24-week follow-up (P > 0.05), but at 24 weeks after treatment, BCVA improvement was significantly better in IVB group (P = 0.049). Significant CMT reduction was observed in each group along the follow-up period (P = 0.001). The mean CMT reduction was more significant in combination (IVB + IVT) group at 2 weeks of follow-up (P < 0.001), but CMT changes were not significant between the groups at weeks 12th and 24th after injection. Overall, retreatment was applied for 59 eyes up to 24 weeks (33 in the IVB group, 26 in the IVB + IVT group). Among patients with 2 or more injections, number of injections was significantly lower in IVB + IVT group (P = 0.043). Three eyes within IVB + IVT group developed IOP rise beyond 21 mmHg, which were controlled with topical anti-glaucoma medications within 1 week. Changes in lens opacity were not significant between two groups.

Conclusion

Eyes treated with IVB plus 1 mg IVT injections had more significant reduction in CMT in early post-injection, but this effect was transient. Although after 24 weeks visual acuity improvement was better in IVB group, combination therapy may decrease the number of injections. Combining 1 mg of intravitreal triamcinolone with bevacizumab was not accompanied with significant side effects.

     

Intravitreal bevacizumab in retinopathy of prematurity: an interventional case series

Background  

To evaluate the results of intravitreal bevacizumab in terms of regression of retinopathy of prematurity (ROP).     

Specific Method Validation and Sample Analysis Approaches for Biocomparability Studies of Denosumab Addressing Method and Manufacture Site Changes

Manufacturing changes during a biological drug product life cycle occur often; one common change is that of the manufacturing site. Comparability studies may be required to ensure that the changes will not affect the pharmacokinetic properties of the drug. In addition, the bioanalytical method for sample analysis may evolve during the course of drug development. This paper illustrates the scenario of both manufacturing and bioanalytical method changes encountered during the development of denosumab, a fully human monoclonal antibody which inhibits bone resorption by targeting RANK Ligand. Here, we present a rational approach to address the bioanalytical method changes and provide considerations for method validation and sample analysis in support of biocomparability studies. An updated and improved ELISA method was validated, and its performance was compared to the existing method. The analytical performances, i.e., the accuracy and precision of standards and validation samples prepared from both manufacturing formulation lots, were evaluated and found to be equivalent. One of the lots was used as the reference standard for sample analysis of the biocomparability study. This study was sufficiently powered using a parallel design. The bioequivalence acceptance criteria for small molecule drugs were adopted. The pharmacokinetic parameters of the subjects dosed with both formulation lots were found to be comparable.     

Transscleral vs transpupillary diode laser photocoagulation for the treatment of zone II type 1 retinopathy of prematurity: Anatomical and refractive outcomes

Purpose:To compare the anatomical and refractive outcomes of transscleral diode versus transpupillary laser photocoagulation for the treatment of zone II type 1 retinopathy of prematurity (ROP).Methods:In this prospective comparative interventional case series, infants with type 1 ROP in zone II were assigned to either transpupillary or transscleral laser based on the surgeons’ expertise area. The rate of regression, need for retreatment, and structural and biometric outcomes at month 6 were evaluated and compared between the two treatment groups.Results:In total, 209 eyes were enrolled; 145 eyes of 77 infants and 64 eyes of 33 infants and were in transscleral and transpupillary groups, respectively. There was no significant difference in baseline characteristics between the groups. There was no significant difference in retreatment rates (1.6% vs. 3.4%; P = 0.669) and progression to stage 4 (1.6% vs. 2.8%; P = 0.999) between the transpupillary and transscleral groups, respectively. At month 6, the mean spherical equivalent was 0.31 ± 3.57 and 0.44 ± 2.85 diopters, and the axial length was 18.28 ± 6.22 and 18.36 ± 6.87 mm in the transpupillary and transscleral groups, respectively, without a significant difference between groups. There was no significant difference in the rate of myopia (43.8% vs. 33.8%; P = 0.169) and high myopia (4.7% vs. 4.8%; P = 0.965) in transpupillary and transscleral groups at month 6.Conclusion:The transpupillary and transscleral laser photocoagulation routes are both effective in the treatment of zone II type 1 ROP and show no significant differences in anatomical or refractive outcomes in relation to the route chosen.     

A population-based comparison between travelers who consulted travel clinics and those who did not

BACKGROUND: Travel to hepatitis A-endemic countries is frequent among North Americans. Such travel carries significant risks for the individuals themselves and for the general population. We documented the patterns of use of travel clinics in a large Canadian adult population. METHODS: Travelers who had visited a hepatitis A-endemic country between 1990 and the time of the survey in 1999 were eligible. Subjects were identified from a representative sample of 4,002 adults from the two largest Canadian provinces. They were contacted by random digit dialing and interviewed by telephone. RESULTS: Only 15% of trips had been preceded by a visit to a travel clinic. The probability of visiting a travel clinic was approximately 10 times greater for travelers considered to be in the high-risk category than for those in the low-risk category, but the former represented only 2% of the total. The probability of visiting a travel clinic was approximately 23 times greater for travelers who were aware of the health risks in their country of destination. Income level was not associated with attendance at a travel clinic, and cost was rarely mentioned as a reason for not attending such a travel clinic before departure. CONCLUSIONS: Each year, millions of Canadian travelers go to hepatitis A-endemic countries without consulting a travel clinic. Active steps must be taken by public health authorities to improve their utilization of health services and prevent the accrued health risk for these travelers.