Channel catfish ovarian fluid differentially enhances blue catfish sperm performance.

For externally fertilizing fishes, interactions between male and female gametes have been shown to have remarkable impacts on sperm performance. Ovarian fluid (OF) and its ability to alter the swimming behavior of fish sperm makes it a determining factor of fertility. With the expansion of channel catfish (Ictalurus punctatus) ♀ × blue catfish (Ictalurus furcatus) ♂ hybrid aquaculture, it is essential to understand the impacts during fertilization and the magnitude such gametic interactions have on sperm performance and subsequent male fertility potential. This study was conducted to address the following: 1) activate blue catfish sperm with/without channel catfish OF to determine impacts on sperm performance and 2) assess if sperm behave differently when activated in the OF from individual females. Sperm (n = 4 males) were activated without OF (control) and with diluted OF from unique females (n = 6), creating 24 experimental crosses. Sperm motility (%), velocity (VCL), and longevity were analyzed using computer assisted sperm analyses software. With OF incorporated in the activation media, sperm velocity was significantly higher than the control at 10, 20, and 30 s post-activation. OF did not have an impact on motility for any females at 10 s and 20 s post-activation but became significantly higher than the control at 30 s. In all cases, OF treatments greatly increased longevity. Male × female interactions were highly significant, such that motility, velocity, and longevity were dependent on specific male-female pairs. This information shows that OF should be incorporated in aquatic media to simulate natural spawning conditions and accurately assess the fluid mechanics of sperm propulsion for each male. Additionally, there are mechanisms that drive gamete interactions that need to be explored further, which may improve selection of male-female pairs for in-vitro fertilization. On a broad scale, our results also help to shed light on the complexities of fertilization and fish reproduction overall, which may have implications for recruitment variability and recovery strategies of threatened and/or endangered freshwater species.

The stool examination reports amoeba cysts: should you treat in the face of over diagnosis and lack of specificity of light microscopy?

Amoebiasis is a common clinical diagnosis in tropical settings and clinicians continue to treat asymptomatic carriers diagnosed by light microscopy. A minority of carriers, however, are infected with Entamoeba histolytica and the remaining with the non-pathogenic Entamoeba dispar. We compared the diagnostic results of 298 asymptomatic residents of Aracaju, Brazil, obtained by different diagnostic methods, and ascertained their clinical symptoms, to highlight the implications for practitioners. Fifty-eight (19.4%) specimens were amoebae positive by microscopy. Of these, 38 (13%) were E. histolytica/E. dispar enzyme-linked immunosorbent assay (ELISA) positive and 4 (1%) E. histolytica ELISA positive. The frequent use of anti-amoebic treatment on the basis of non-specific symptoms and the findings of light microscopy tests is not justified. Methods for the specific diagnosis of E. histolytica infection for developing countries are urgently needed.

Controlling human capital costs in the new millennium.

Low productivity and high turnover can be more costly to employers than insurance premiums and medical claims. This article discusses the need for coordinated management of all behavioral health benefits. It provides two case studies that illustrate how such coordination can avert possible long-term costs and loss of a valued employee.