Morphology of the novel ventral scape gland in the ant genus Strumigenys

We describe a novel ventral scape gland in all 19 species of the genus Strumigenys that we examined, confirming the postulated existence of this gland by Bolton (1999). The gland occurs in workers and queens; it belongs to 'class-1' and is formed by a layer of epithelial secretory cells that line the ventrodistal tegumental cuticle of the antennal scape. The gland is characterized by its bowl-shape, by the ultrastructural characteristics of microvillar arrangement and by the presence of nerves in between the epithelial cells. These features make this gland structurally very similar to 3 other epithelial glands that occur exclusively in Strumigenys. Besides the epithelial ventral scape gland, also scattered class-3 glandular cells are found. The function of both glands in the scape remains unclear, although a role in prey attraction cannot be excluded.

Cerebrospinal fluid pleocytosis as a predictive factor for CSF and plasma HIV RNA discordance and escape

The aims of this study were to investigate the frequency of HIV-1 RNA level discordance between the cerebrospinal fluid (CSF) and plasma and of CSF viral escape (CVE) in patients with HIV-1 subtype C on antiretroviral therapy, and evaluate the CSF white blood cell (WBC) performance characteristics in predicting CSF discordance in HIV+ group and the frequency of cognitive impairment in individuals with CSF HIV discordance or escape. HIV-1 RNA levels were assessed in plasma and CSF samples from 68 HIV+ participants without opportunistic infection. CSF discordance was found in 7.4% and CVE in 10%, with comparable frequencies between HIV-1B and C. Twenty samples (29%) showed increased CSF WBC counts. This group had higher CSF and plasma HIV-1 RNA levels than the group with normal WBC counts (p < 0.0001 and 0.006, respectively). The odds of CSF discordance were 18 times higher for a person with CSF WBC count of > 5 cells/mm3 than the group with normal CSF WBC count. CSF WBC counts (cut-off of 15 cells/mm3) showed high-performance characteristics as a predictive biomarker of CSF discordance (AUC the ROC curve 0.98). The frequency of cognitive impairment for CSF escape or discordance was 83% and 80%. The odds of cognitive impairment in these groups were 19 and 15 times higher than those for an HIV(-) person. Viral discordance or escape in the CNS occurs at a comparable frequency for HIV-1C and HIV-1B. The CSF WBC count was effective as a predictive biomarker of CSF and plasma discordance.