Patterns of cranial ontogeny in lacertid lizards: morphological and allometric disparity.

We explored the ontogenetic dynamics of the morphological and allometric disparity in the cranium shapes of twelve lacertid lizard species. The analysed species (Darevskia praticola, Dinarolacerta mosorensis, Iberolacerta horvathi, Lacerta agilis, L. trilineata, L. viridis, Podarcis erhardii, P. melisellensis, P. muralis, P. sicula, P. taurica and Zootoca vivipara) can be classified into different ecomorphs: terrestrial lizards that inhabit vegetated habitats (habitats with lush or sparse vegetation), saxicolous and shrub-climbing lizards. We observed that there was an overall increase in the morphological disparity (MD) during the ontogeny of the lacertid lizards. The ventral cranium, which is involved in the mechanics of jaw movement and feeding, showed higher levels of MD, an ontogenetic shift in the morphospace planes and more variable allometric patterns than more conserved dorsal crania. With respect to ecology, the allometric trajectories of the shrub-climbing species tended to cluster together, whereas the allometric trajectories of the saxicolous species were highly dispersed. Our results indicate that the ontogenetic patterns of morphological and allometric disparity in the lacertid lizards are modified by ecology and functional constraints and that the identical mechanisms that lead to intraspecific morphological variation also produce morphological divergence at higher taxonomic levels.

Outbreak of West Nile virus infection among humans in Serbia, August to October 2012.

We describe the first reported outbreak of West Nile virus (WNV) infection in humans in Serbia in August to October 2012 and examine the association of various variables with encephalitis and fatal outcome. Enzyme-linked immunosorbent assay (ELISA) was used for detection of WNV-specific IgM and IgG antibodies in sera and cerebrospinal fluid. A total of 58 patients (mean age: 61 years; standard deviation: 15) were analysed: 44 were from Belgrade and its suburbs; 52 had neuroinvasive disease, of whom 8 had meningitis, while 44 had encephalitis. Acute flaccid paralysis developed in 13 of the patients with encephalitis. Age over 60 years and immunosuppression (including diabetes) were independently associated with the development of encephalitis in a multivariate analysis: odds ratio (OR): 44.8 (95% confidence interval (CI): 4.93­408.59); p=0.001 (age over 60 years); OR: 10.76 (95% CI: 1.06­109.65); p=0.045 (immunosuppression including diabetes). Respiratory failure requiring mechanical ventilation developed in 13 patients with encephalitis. A total of 35 patients had completely recovered by the time they were discharged; nine patients died. The presence of acute flaccid paralysis, consciousness impairment, respiratory failure and immunosuppression (without diabetes) were found to be associated with death in hospital in a univariate analysis (p<0.001, p=0.007, p<0.001 and p=0.010, respectively).

Autoradiographic localization of particulate cyclic AMP-dependent protein kinase in mammalian brain using [3H]cyclic AMP: implications for organization of second messenger systems.

Cyclic AMP's regulatory role as an intracellular second messenger is well established. In brain and other tissues, specific proteins that bind cyclic AMP have been shown to be the regulatory subunits of cystolic and particulate cyclic AMP-dependent protein kinases. This study of the autoradiographic localization of specific [3H]cyclic AMP binding revealed the heterogeneous distribution of particulate cyclic AMP-dependent protein kinase in the mammalian central nervous system. Specific [3H]cyclic AMP binding to tissue sections was of high affinity (KD = 60 nM) and saturable (Bmax = 5 pmol/mg protein). Purine and pyrimidine nucleotide analogues demonstrated inhibition constants against [3H]cyclic AMP binding consistent with the specific labelling of cyclic AMP-dependent protein kinase (e.g. 8'-bromo-cyclic AMP: IC50 = 130 nM; inosine 3',5'-cyclic monophosphate: IC50 = 1 microM; uridine 3',5'-cyclic monophosphate: IC50 = 60 microM). Variations in the levels of [3H]cyclic AMP binding presumably reflect the presence of differing amounts of particulate cyclic AMP-dependent protein kinase in different neuronal populations. Highest densities were associated with neuronal cell layers such as the pyramidal cells of the piriform cortex and hippocampus, and granule cells of the dentate gyrus and cerebellum. High levels of binding were also found in other cortical and limbic structures, while moderate levels were found in hypothalamic, thalamic and midbrain areas. Excitotoxic lesions confirmed the localization of the enzyme in hippocampal pyramidal cells and cerebellar granule cells. Localizations reported in this study are largely consistent with results obtained using immunohistochemical methods to label cyclic AMP-dependent protein kinases. Recently, [3H]forskolin, a potent and selective activator of adenylate cyclase, the enzyme responsible for the formation of cyclic AMP from adenosine 5'-triphosphate, has been used to localize the activated catalytic component of this enzyme in rat brain. Regions described as being intensely labelled with [3H]forskolin (e.g. basal ganglia, hilus of the dentate gyrus and molecular layer of the cerebellum) were found to be associated with relatively low [3H]cyclic AMP binding levels. These findings suggest a marked difference between the localization of the two related enzyme entities. However, the distribution of the enzymes is indirectly correlated as high levels of particulate cyclic AMP-dependent protein kinase are present in the soma of neurons with high concentrations of adenylate cyclase in their terminals. Alternatively, it is possible that [3H]forskolin localizes only a subpopulation of adenylate cyclase.(ABSTRACT TRUNCATED AT 400 WORDS)