Efficacy of Post-Exposure Prophylaxis in Infants Born to HBsAg Positive Mothers in Iran; Is It Authentic?

Background Hepatitis B infection is a universal concern. This infection can lead to chronic liver disease and hepatocellular carcinoma. Neonates born to HBsAg-positive mothers are at high risk of chronic hepatitis B virus (HBV) infection, especially for HBeAg-positive mothers or neonates who have not received hepatitis B immunoglobulin (HBIg) and HBV vaccines. Objectives The aim of this study was to evaluate the efficacy of post-exposure prophylaxis in these infants to prevent infection. Patients and Methods Thirty-eight infants born to HBsAg-positive mothers between September 2006 and September 2013 were followed. The investigation evaluated whether the standard prevention protocol of neonatal HBV transmission including HBIg at birth and receiving three doses of vaccine at birth and 2 and 6 months of age was performed, followed by post-vaccination tests (evaluation of HBsAg and HBsAb titer at 9 to 18 months of age) to determine subsequent infection. HBsAb titer ≥ 10 was considered as criterion for effectiveness of the prophylaxis procedure. The acquired data were analyzed using SPSS software (Version 18). The results are reported in descriptive tabulations. Results Ninety seven percent (97%) of infants received HBIg at birth in the hospital. Generally, all of them received the first, second and third doses of vaccine at birth, 2 months, and 6 months after birth, respectively. Information for 35 mothers infected with HBV and 38 infants was available. The mean age of the mothers was 30.3 years. The results indicated that 20% of mothers were HBeAg positive. HBsAg was positive in one (2.6%) infant born to an HBeAg-positive mother. Around 94% of infants’ HBsAb titers were ≥ 10, and 5.8% were reported as non-responders. Conclusions The vertical transmission prevention program used in the study population in Tehran, which had an appropriate sample size, is effective. Additional doses of the vaccine can be useful in raising the effectiveness of immunoprophylaxis for infants at high risk of HBV infection. Also, emphasis must be set on post-vaccination testing

Controlled oxidation of iron nanoparticles in chemical vapour synthesis

In the present study, iron oxide nanoparticles (primary particle size of 80-90 nm) with controlled oxidation state were prepared via an atmospheric pressure chemical vapour synthesis (APCVS) method. Iron pentacarbonyl [Fe(CO)5], a precursor material, was thermally decomposed to iron in the APCVS reactor. Subsequently, the iron was oxidized with controlled amount of oxygen in the reactor to produce nearly pure magnetite or haematite particles depending on the oxygen concentration. Size, morphology and crystal structure of the synthesized nanoparticles were studied with scanning mobility particle sizer (SMPS), transmission electron microscopy (TEM) and X-ray diffraction (XRD). In addition, thermodynamic equilibrium calculations and computational fluid dynamics model were used to predict the oxidation state of the iron oxides and the reaction conditions during mixing. Aggregates of crystalline particles were formed, determined as magnetite at the oxygen volumetric fraction of 0.1 % and haematite at volumetric fraction of 0.5 %, according to the XRD. The geometric mean electrical mobility diameter of the aggregates increased from 110 to 155 nm when the volumetric fraction of oxygen increased from 0.1 to 0.5 %, determined using the SMPS. The aggregates were highly sintered based on TEM analyses. As a conclusion, APCVS method can be used to produce nearly pure crystalline magnetite or haematite nanoparticles with controlled oxidation in a continuous one-stage gas-phase proces