The diagnostic value of an anti-mu-capture immunoassay for the detection of IgM antibody against hepatitis B core antigen (anti-HBc) was evaluated. Strongly positive results were obtained from the acute phase sera of the 25 acute hepatitis B patients who were hepatitis B surface antigen (HBsAg) positive and of the 18 confirmed acute hepatitis B patients who had already cleared HBsAg when symptoms developed. Negative results were obtained in 5 hepatitis A patients, 20 non-A, non-B acute hepatitis patients serologically susceptible to HBV, 22 patients with chronic hepatitis B liver disease, 15 asymptomatic HBsAg carriers, and 10 healthy patients immune from past HBV infection. Fourteen of the acute hepatitis patients remained HBsAg positive for a follow-up period of at least 6 months, and 12 of these were found consistently anti-HBc IgM negative. These were considered as chronic HBsAg carriers with a superimposed form of acute liver injury. These data show that this assay can differentiate between acute from chronic (HBsAg positive) and recent from old (HBsAg negative) hepatitis B virus infection. Thus, it should be very useful in the complex diagnostic situations encountered commonly in areas with high prevalence of HBV infections.

Brackish aquaponics using Mediterranean fish and plants provides an alternative opportunity for a combined production of high-quality food products with high commercial and nutritional value. This is the first study that investigates the effect of two different salinities (8 and 20 ppt) on growth and survival of Sparus aurata and Crithmum maritimum along with the cellular stress pathways using the activation of heat shock proteins (HSPs) and mitogen-activated protein kinase (MAPK) protein family members and the water bacterial abundance. In total, 156 fish were used (average initial weight of 2.55 g, length of 5.57 cm) and 36 plants (average initial height of 8.23 cm) in floating racks above the 135 L fish tanks. Survival rate for both organisms was 100%. C. crithmum grew better at 8 ppt (t-test, p < 0.05). The growth rate of S. aurata was similar for both treatments (p > 0.05). HSPs and MAPK were differentially expressed, showing tissue-specific responses. The average bacterial abundance at the end of the experiment was higher (p < 0.05) in the 20 ppt (18.6 ± 0.91 cells × 105/mL) compared to the 8 ppt (6.8 ± 1.9 cells × 105/mL). The results suggest that the combined culture of euryhaline fish and halophytes provides good quality products in brackish aquaponics systems.

The possible source of infection due to hepatitis B virus (HBV) was investigated in 260 hospitalized adult patients with acute infections. Blood transfusions (30 patients, 11.5%), illicit drug use (16 patients, 6.2%), homosexuality (five patients, 1.9%), and possible iatrogenic transmission (77 patients, 29.6%) accounted for less than 50% of the cases of hepatitis. Thirty (29.4%) of 102 sexual partners were the most probable source of infection of the patients; three (2.9%) had a history of acute HBV infection two to six months before their partners were admitted to the hospital, and the remaining 27 (26.5%) were characterized as asymptomatic, chronic carriers of hepatitis B surface antigen (HBsAg). The HBsAg carrier rate was higher in men (47.5%) than women (12.9%) and in unmarried (31.6%) than married (25.3%) sexual partners. Hepatitis B e antigen and abnormal serum glutamic pyruvic transaminase levels were detected more frequently in sexual partners who were HBsAg carriers (29.6% and 48.1%, respectively) than in comparable control partners (2.6% and 5.4%, respectively).

Aquaponics provides an alternative opportunity for the combined production of fish and plants. Most of the essential nutrients required for optimal plant growth can be supplied from the fish feed, except for K and Fe. These nutrients are usually inadequate in fish feed. In this study, red tilapia and rocket plants were co-cultivated in an aquaponics system along with the extra addition of K and Fe. Fish growth, morpho-anatomical characteristics, and K and Fe loading on fish gills were studied. Plant growth parameters were also determined. The addition of Fe and K slightly improved the produced fresh biomass of rocket per unit area and had no impact on tilapia growth and survival. No severe histological alterations in fish gills, liver, and midgut were detected. EDX analysis showed that the addition of K led to the enrichment of this specific ion in fish gills, but no effects of this accumulation were found on other aspects of fish growth and survival.

The prevalence of serologic evidence of hepatitis B virus infection in various populations in Greece was examined to provide data for formulating cost-effective strategies for prevaccination screening. Markers were detected in 17.5% of 320 healthy persons, 73.3% of 273 multiply transfused patients and 61.0% of 146 haemodialysis patients. In multiply transfused patients, antibody to hepatitis B surface antigen (anti-HBs) was significantly more common than antibody to core antigen (anti-HBc) (67.0%, 44.3%), while the opposite was true for haemodialysis patients (43.8%, 57.5%). These data suggest that it may be most cost-effective to screen only for anti-HBs in multiply transfused patients and only anti-HBc in haemodialysis patients. Vaccination without screening may be more cost-effective for healthy persons. Anti-HBs and anti-HBc were detected with similar frequencies (14.7%, 15.9%), thus neither offers an advantage in screening healthy persons, although use of anti-HBc may facilitate detection of chronic carriers. These data indicate that the choice of marker for pre-vaccination screening should depend on the population under consideration.