In vivo infectivity of liver extracts after resolution of hepadnaviral infection following therapy associating DNA vaccine and cytokine genes

DNA‐based vaccination appears of promise for chronic hepatitis B immunotherapy, although there is an urgent need to increase its efficacy. In this preclinical study, we evaluated the therapeutic benefit of cytokine (IL‐2, IFN‐γ) genes co‐delivery with DNA vaccine targeting hepadnaviral proteins in the chronic duck hepatitis B virus (DHBV) infection model. Then, we investigated the persistence of replication‐competent virus in the livers of apparently resolved animals. DHBV carriers received four injections of plasmids encoding DHBV envelope and core alone or co‐delivered with duck IL‐2 (DuIL‐2) or duck IFN‐γ (DuIFN‐γ) plasmids. After long‐term (8 months) follow‐up, viral covalently closed circular (ccc) DNA was analysed in duck necropsy liver samples. Liver homogenates were also tested for in vivo infectivity in neonatal ducklings. Co‐delivery of DuIFN‐γ resulted in significantly lower mean viremia starting from week 21. Viral cccDNA was undetectable by conventional methods in the livers of 25% and 57% of animals co‐immunized with DuIL‐2 and DuIFN‐γ, respectively. Interestingly, inoculation of liver homogenates from 7 such apparently resolved animals, exhibiting cccDNA undetectable in Southern blotting and DHBV expression undetectable or restricted to few hepatocytes, revealed that three liver homogenates transmitted high‐titre viremia (3–5×10¹⁰ vge/mL) to naïve animals. In conclusion, our results indicate that IFN‐γ gene co‐delivery considerably enhances immunotherapeutic efficacy of DNA vaccine targeting hepadnaviral proteins. Importantly, we also showed that livers exhibiting only minute amounts of hepadnaviral cccDNA could induce extremely high‐titre infection, highlighting the caution that should be taken in occult hepatitis B patients to prevent HBV transmission in liver transplantation context.     

Reevaluation of steroid tapering after steroid pulse therapy for heart rejection.

A retrospective analysis was conducted to determine the efficacy and complications resulting from steroid pulse therapy, with or without a steroid taper, in 93 episodes of heart transplant rejection that occurred in 72 patients (58 men, 14 women; mean age, 47.6 years). Each rejection episode was classified according to severity (Texas Heart Institute endomyocardial biopsy scale) and the treatment. Group 1 included 25 episodes of grade 7, 8, 9, or 10 rejection (International Society for Heart Transplantation [ISHT] grade IIIB or IV) that were treated with high-dose methylprednisolone (2.5 to 3.0 gm) and a steroid taper of 1.75 gm over 30 days. Group 2 included 16 episodes of rejection, with the severity of rejection and methylprednisolone pulse therapy being similar to that in group 1, but without a steroid taper. The results of treatment in group 1 were compared with those in group 2. Group 3 included 12 episodes of grade 5, 6, or 7 rejection (ISHT grade IIIA or IIIB) that were treated with moderate-dose methylprednisolone (1.0 to 2.0 gm) and a steroid taper, as described. Group 4 included 40 episodes of rejection, with the severity of rejection and methylprednisolone therapy being similar to that of group 3, but without a steroid taper. The results of treatment in group 3 were compared with those in group 4. No statistically significant differences were found among the groups regarding subsequent episodes of rejection or infection within 3 months of treatment. No statistically significant difference was noted among the groups in the number of rejection episodes requiring additional therapy to control the rejection.(ABSTRACT TRUNCATED AT 250 WORDS)     

Advax™, a polysaccharide adjuvant derived from delta inulin, provides improved influenza vaccine protection through broad-based enhancement of adaptive immune responses

Advax™ adjuvant is derived from inulin, a natural plant-derived polysaccharide that when crystallized in the delta polymorphic form, becomes immunologically active. This study was performed to assess the ability of Advax™ adjuvant to enhance influenza vaccine immunogenicity and protection. Mice were immunized with influenza vaccine alone or combined with Advax™ adjuvant. Immuno-phenotyping of the anti-influenza response was performed including antibody isotypes, B-cell ELISPOT, CD4 and CD8 T-cell proliferation, influenza-stimulated cytokine secretion, DTH skin tests and challenge with live influenza virus. Advax™ adjuvant increased neutralizing antibody and memory B-cell responses to influenza. It similarly enhanced CD4 and CD8 T-cell proliferation and increased influenza-stimulated IL-2, IFN-γ, IL-5, IL-6, and GM-CSF responses. This translated into enhanced protection against mortality and morbidity in mice. Advax™ adjuvant provided significant antigen dose-sparing compared to influenza antigen alone. Protection could be transferred from mice that had received Advax™-adjuvanted vaccine to naïve mice by immune serum. Enhanced humoral and T-cell responses induced by Advax™-formulated vaccine were sustained 12 months post-immunization. Advax™ adjuvant had low reactogenicity and no adverse events were identified. This suggests Advax™ adjuvant could be a useful influenza vaccine adjuvant.     

Changes in light-induced fluorescence of cervical collagen in guinea pigs during gestation and after sodium nitroprusside treatment.

Light-induced fluorescence (LIF) of collagen was used to investigate in vivo changes in cervical collagen in guinea pigs during gestation and following sodium nitroprusside treatment. Natural fluorescence of collagen is due to collagen cross-linking molecules that connect single collagen fibers and therefore provide rigidity of the cervical stroma. LIF of cervical collagen was measured from the surface of the exocervix in anesthetized nonpregnant and timed pregnant guinea pigs at different times of gestation with an instrument designed in our lab (Collascope). Measurements were also performed in guinea pigs at midgestation before and 8 hours after intracervical treatment with sodium nitroprusside. Collagen fluorescence decreased significantly as pregnancy progressed, reached lowest values at delivery, and increased gradually postpartum. Treatment with sodium nitroprusside, but not with the vehicle, caused a significant decrease in LIF (p = 0.007). We conclude, that LIF changes in the cervix reflect the gradual cervical softening (ripening) during pregnancy and the return to the rigid state of the cervix postpartum. Cervical softening during pregnancy, and after sodium nitroprusside treatment, is associated with a decrease in collagen cross-links. Measurements of LIF can be used to investigate cervical softening in vivo.     

Bernard-Soulier syndrome in pregnancy; a report of four pregnancies in one patient, and review of the literature

Bernard-Soulier Syndrome is a rare autosomal recessive bleeding disorder characterized by a normal or low platelets count, the presence of giant platelets, and a prolonged bleeding time. Only five pregnant patients with this disease have been previously reported. Most of the complications seem to occur in the intrapartum or postpartum period. In some patients the disease can go unrecognized until the third or fourth decade. Our patient had two uneventful pregnancies, one pregnancy with early postpartum hemorrhage, and another pregnancy with intrapartum and late postpartum bleeding. Although the optimum mode of delivery is not clear yet, the vaginal route should be considered unless otherwise obstetrically indicated. Management of active bleeding episodes is also debatable; it includes platelets transfusions, desmopressin (DDAVP), antifibrinolytic therapy, and ecbolic agents for postpartum hemorrhage.     

Effect of gestational age and position on peak expiratory flow rate: a longitudinal study

OBJECTIVE: We sought to study the effects of gestational age and maternal position on peak expiratory flow rates. METHODS: Peak expiratory flow rates were measured in the standing, sitting, and supine positions in 38 healthy pregnant women at 4-week intervals starting at less than 10 weeks until delivery and again at 6 weeks postpartum. The highest reading of 3 consecutive peak expiratory flow rate measurements for each encounter and position was used in the analysis. Repeated measures analysis of covariance was performed with subjects, gestational age, position, and gestational age times position as the model effects. Least squares mean peak expiratory flow rates were compared among positions at different gestation ages using Bonferroni-adjusted least significant difference t tests. RESULTS: Peak expiratory flow rate declined significantly throughout gestation in all positions (P < .001) with mean rate of decline of 0.65 L/min per week). The slopes of linear trends were not statistically different between positions (P = .222). However, the rate of decline for the supine position was higher than for standing and sitting positions (0.86 compared with 0.46 and 0.57 L/min per week), respectively. On average, the postpartum peak expiratory flow rate returned to 71.9% of its measurement in early gestation. Nomograms depicting mean and the 5th and 95th percentiles of peak expiratory flow rates were constructed for each position. CONCLUSION: Peak expiratory flow rate measurements are affected by maternal position and advancing gestational age, especially in the supine position. Adjustment of patient's flow rate in relation to gestational age and maternal position is recommended, especially in pregnant women with asthma. LEVEL OF EVIDENCE: III.