Ciliates from the intestine of zoo-kept black rhinoceros, with immunofluorescence microscopic and molecular phylogenetic investigation of Rhinozeta rhinozeta (Litostomatea).

The study of endobiotic ciliates from the intestines of various zoo mammals is important for revealing the influence of various factors on endobiont communities. In this paper we describe the species diversity of endobiotic ciliates from the faeces of the eastern black rhinoceros Diceros bicornis michaeli (male and two females, mother and daughter) kept in the zoo. Seven species of the ciliates were found, among them Rhinozeta rhinozeta, R. triciliata and Prototapirella clypeata were observed in the rhinos only. The other two, Monoposthium sp. and Triplumaria sp., according to their morphology should have been identified as new ciliate species. Successful transmission of the endobionts from parents to the young rhino in the zoo was demonstrated. R. rhinozeta was investigated with the using of the methods of the light and immunofluorescence microscopy and molecular phylogeny. The composition and phylogeny of the family Cycloposthiidae were discussed.

Verbal Abilities: Sex Differences in Children at Different Ages.

Background: The assertion of sex differences in verbal abilities is a highly controversial subject. Some studies have demonstrated a female advantage; other studies have found higher rates in males. The results depended on the type of verbal ability that was studied, the cultural context, and the ages of the subjects. There are two types of theories that have been developed to explain the existence of sex differences in cognitive abilities. Social theories explain the differences as caused by social determinants. Biological theories consider biological factors such as prenatal development conditions and hormone levels, among others, as the cause of sex differences. Objective: To investigate sex differences in verbal abilities in children of different ages. Design: Two different editions of Wechsler tests were used. For children age 2.5 to 5 years, the Wechsler Preschool Primary Scale of Intelligence (WPPSI-IV) was used. For children age 6 and older, we administered the Wechsler Intelligence Scale for Children (WISC-V). The total sample included 313 children. Results: The study found significant sex differences in performance on the Verbal Comprehension Scale in children of different ages. At the age of 2 to 4 years, the girls performed better than the boys. In the group of boys, there was a significant increase in verbal abilities at the age of 8-9 years. By the age of 10-11 years, boys began outperforming girls on the Verbal Comprehension Index. Scores on the Verbal Comprehension and Visual Spatial subtests for the boy sample showed stronger correlations than in the girl sample in all age groups. Conclusion: Sex differences in verbal abilities varied depending on the age of the children. The boys showed a stronger integration of their verbal abilities into the structure of their intelligence than the girls.

GAT inhibition preserves cerebral blood flow and reduces oxidant damage to mitochondria in rodents exposed to extreme hyperbaric oxygen.

Oxygen breathing at elevated partial pressures (PO2's) at or more than 3 atmospheres absolute (ATA) causes a reduction in brain γ-aminobutyric acid (GABA) levels that impacts the development of central nervous system oxygen toxicity (CNS-OT). Drugs that increase brain GABA content delay the onset of CNS-OT, but it is unknown if oxidant damage is lessened because brain tissue PO2 remains elevated during hyperbaric oxygen (HBO2) exposures. Experiments were performed in rats and mice to measure brain GABA levels with or without GABA transporter inhibitors (GATs) and its influence on cerebral blood flow, oxidant damage, and aspects of mitochondrial quality control signaling (mitophagy and biogenesis). In rats pretreated with tiagabine (GAT1 inhibitor), the tachycardia, secondary rise in mean arterial blood pressure, and cerebral hyperemia were prevented during HBO2 at 5 and 6 ATA. Tiagabine and the nonselective GAT inhibitor nipecotic acid similarly extended HBO2 seizure latencies. In mice pretreated with tiagabine and exposed to HBO2 at 5 ATA, nuclear and mitochondrial DNA oxidation and astrocytosis was attenuated in the cerebellum and hippocampus. Less oxidant injury in these regions was accompanied by reduced conjugated microtubule-associated protein 1A/1B-light chain 3 (LC3-II), an index of mitophagy, and phosphorylated cAMP response element binding protein (pCREB), an initiator of mitochondrial biogenesis. We conclude that GABA prevents cerebral hyperemia and delays neuroexcitation under extreme HBO2, limiting oxidant damage in the cerebellum and hippocampus, and likely lowering mitophagy flux and initiation of pCREB-initiated mitochondrial biogenesis.

Increased Antiseizure Effectiveness with Tiagabine Combined with Sodium Channel Antagonists in Mice Exposed to Hyperbaric Oxygen.

Hyperbaric oxygen (HBO2) is acutely toxic to the central nervous system, culminating in EEG spikes and tonic-clonic convulsions. GABA enhancers and sodium channel antagonists improve seizure latencies in HBO2 when administered individually, while combining antiepileptic drugs from different functional classes can provide greater seizure latency. We examined the combined effectiveness of GABA enhancers (tiagabine and gabapentin) with sodium channel antagonists (carbamazepine and lamotrigine) in delaying HBO2-induced seizures. A series of experiments in C57BL/6 mice exposed to 100% oxygen at 5 atmospheres absolute (ATA) were performed. We predicted equally effective doses from individual drug-dose response curves, and the combinations of tiagabine + carbamazepine or lamotrigine were tested to determine the maximally effective combined doses to be used in subsequent experiments designed to identify the type of pharmacodynamic interaction for three fixed-ratio combinations (1:3, 1:1, and 3:1) using isobolographic analysis. For both combinations, the maximally effective combined doses increased seizure latency over controls > 5-fold and were determined to interact synergistically for fixed ratios 1:1 and 3:1, additive for 1:3. These results led us to explore whether the benefits of these drug combinations could be extended to the lungs, since a centrally mediated mechanism is believed to mediate hyperoxic-induced cardiogenic lung injury. Indeed, both combinations attenuated bronchoalveolar lavage protein content by ~ 50%. Combining tiagabine with carbamazepine or lamotrigine not only affords greater antiseizure protection in HBO2 but also allows for lower doses to be used, minimizing side effects, and attenuating acute lung injury.