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.     

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.     

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).     

Impact of Glycoprotein IIb/IIIa Inhibitors Use on Outcomes After Lower Extremity Endovascular Interventions From Nationwide Inpatient Sample (2006–2011)

• Anticoagulant and antiplatelet medications are necessary in peripheral endovascular intervention, but a standardized approach has not yet been established.
• Glycoprotein IIb/IIIa inhibitor use in endovascular lower extremity interventions decreased overall amputation rates.
• Glycoprotein IIb/IIIa inhibitor use in endovascular lower extremity interventions increased postprocedural bleeding and complications requiring intervention.

     

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.     

Ineffectiveness of the current strategy to prevent hepatitis A in travelers

BACKGROUND: Each year, a large number of Canadians travel to regions of the world where hepatitis A remains endemic. Many of these travelers are not immune and the current preventive strategy relies wholly on self-referral to a travel clinic. All of the costs associated with such a visit are assumed by the traveler. We estimated the effectiveness of this strategy. METHODS: This case-control study included 108 travel-related hepatitis A cases with onset of disease between 1997 and 1999 and 620 controls who traveled during the same period. RESULTS: Hepatitis A was strongly associated with high-risk travel (Odds Ratio = 7.2, 95% Confidence Interval 1.76-29.4), but only 7% of cases were found in this category. The risk of hepatitis A was 5 times lower in travelers who visited a travel clinic than in those who did not (80% efficacy). However, only 14% of the controls visited a travel clinic. As a result, the effectiveness of the current strategy is estimated to be 11% (80% of 14%). CONCLUSIONS: Hepatitis A in travelers can be prevented effectively by attendance at a travel clinic. Unfortunately, most travelers do not visit such clinics prior to departure. Even if all high-risk travelers were to visit a travel clinic and receive vaccination, this would have negligible impact on the number of travel-related hepatitis A cases (approximately 7% reduction). The current strategy for the prevention of hepatitis A in travelers is ineffective and should be reexamined.