Ventilatory and carotid body chemoreceptor responses to purinergic P2X receptor antagonists in newborn rats

Adenosine triphosphate, acting through purinergic P2X receptors, has been shown to stimulate ventilation and increase carotid body chemoreceptor activity in adult rats. However, its role during postnatal development of the ventilatory response to hypoxia is yet unknown. Using whole body plethysmography, we measured ventilation in normoxia and in moderate hypoxia (12% fraction of inspired O?, 20 min) before and after intraperitoneal injection of suramin (P2X? and P2X? receptor antagonist, 40 mg/kg) in 4-, 7-, 12-, and 21-day-old rats. Suramin reduced baseline breathing (～20%) and the response to hypoxia (～30%) in all rats, with a relatively constant effect across ages. We then tested the effect of the specific P2X? antagonist, A-317491 (150 mg/kg), in rats aged 4, 7, and 21 days. As with suramin, A-317491 reduced baseline ventilation (～55%) and the hypoxic response (～40%) at all ages studied. Single-unit carotid body chemoreceptor activity was recorded in vitro in 4-, 7-, and 21-day-old rats. Suramin (100 μM) and A-317491 (10 μM) significantly depressed the sinus nerve chemosensory discharge rate (～80%) in normoxia (Po? ～150 Torr) and hypoxia (Po? ～60 Torr), and this decrease was constant across ages. We conclude that, in newborn rats, P2X purinergic receptors are involved in the regulation of breathing under basal and hypoxic condition, and P2X?-containing receptors play a major role in carotid body function. However, these effects are not age dependent within the age range studied.     

In-solution staining and arraying method for the immunofluorescence detection of γH2AX foci optimized for clinical applications

Immunofluorescence quantification of γH2AX foci is a powerful approach to quantify DNA double-strand breaks induced by cancer therapy or accidental exposure to ionizing radiation. Here we report a modification to the γH2AX immunofluorescence labeling method, whereby cells are stained in-solution before being spotted and fixed onto microscope slides. Our modified method allows arraying of 16 patient samples/slide ready for foci counting in 2 h and demonstrated reliably detection of γH2AX foci in mononuclear cells prepared from patients who had undergone radiation therapy.     

Early Pleistocene human mandible from Sima del Elefante (TE) cave site in Sierra de Atapuerca (Spain): a palaeopathological study

Here we present a detailed palaeopathological study of the hominin mandible ATE9-1 found at the Sima del Elefante site (TE), Sierra de Atapuerca, Spain. This fossil represents the earliest hominin remains from Western Europe with an age of ca. 1.3 Ma. The specimen displays several dento-gnathic lesions; the antiquity and geographic location of this fossil justifies a detailed palaeopathological study to determine if the pathologies have significantly altered taxonomically relevant features. Our study reveals severe dental attrition combined with generalized hypercementosis, alveolar root exposure, mild periodontal disease, tooth dislocation, and an anomalous occlusal plane. We have also observed calculus deposits, two cystic lesions and an anomalous wear facet compatible with tooth picking. The majority of these pathological signs can be explained by compensatory eruption. We propose that these lesions are associated as causes, consequences, and amplifiers of one another within the framework of heavy and even traumatic occlusion, masticatory habits, or both traumatic occlusion and masticatory habits. Despite the severity of these lesions, occlusion was at least partially functional so it was unlikely to influence the survival of this individual. In addition, the lesions do not prohibit the taxonomic assessment of the mandible.     

Early Pleistocene human mandible from Sima del Elefante (TE) cave site in Sierra de Atapuerca (Spain): a comparative morphological study

We present a detailed morphological comparative study of the hominin mandible ATE9-1 recovered in 2007 from the Sima del Elefante cave site in Sierra de Atapuerca, Burgos, northern Spain. Paleomagnetic analyses, biostratigraphical studies, and quantitative data obtained through nuclide cosmogenic methods, place this specimen in the Early Pleistocene (1.2-1.3 Ma). This finding, together with archaeological evidence from different European sites, suggests that Western Europe was colonised shortly after the first hominin expansion out of Africa around the Olduvai subchron. Our analysis of the ATE9-1 mandible includes a geometric morphometric analysis of the lower second premolar (LP₄), a combined and detailed external and internal assessment of ATE9-1 roots through CT and microCT techniques, as well as a comparative study of mandibular and other dental features. This analysis reveals some primitive Homo traits on the external aspect of the symphysis and the dentition shared with early African Homo and the Dmanisi hominins. In contrast, other mandibular traits on the internal aspect of the symphysis are derived with regard to African early Homo, indicating unexpectedly large departures from patterns observed in Africa. Reaching the most occidental part of the Eurasian continent implies that the first African emigrants had to cross narrow corridors and to overcome geographic barriers favouring genetic drift, long isolation periods, and adaptation to new climatic and seasonal conditions. Given these conditions and that we are dealing with a long time period, it is possible that one or more speciation events could have occurred in this extreme part of Eurasia during the Early Pleistocene, originating in the lineages represented by the Sima del Elefante-TE9 hominins and possibly by the Gran Dolina-TD6 hominins. In the absence of any additional evidence, we prefer not include the specimen ATE9-1 in any named taxon and refer to it as Homo sp.     

The NAC domain mediates functional specificity of CUP-SHAPED COTYLEDON proteins

In higher plants, although several genes involved in shoot apical meristem (SAM) formation and organ separation have been isolated, the molecular mechanisms by which they function are largely unknown. CUP-SHAPED COTYLEDON (CUC) 1 and CUC2 are examples of two such genes that encode the NAC domain proteins. This study investigated the molecular basis for their activities. Nuclear localization assays indicated that green fluorescent protein (GFP)-CUC proteins accumulate in the nucleus. Yeast one-hybrid and transient expression assays demonstrated that the C-terminal domain (CTD) of the CUC has transactivation activity. Domain-swapping experiments revealed that the functional specificity of the CUC for promoting adventitious shoot formation resides in the highly conserved NAC domain, not in the CTD in which motifs specific to the CUC subfamily are located. Taken together, these observations suggest that CUC proteins transactivate the target genes involved in SAM formation and organ separation through a specific interaction between the NAC domain and the promoter region of the target genes.     

The effect of IL-1beta on the expression of inflammatory cytokines and their receptors in human chondrocytes

Cytokines released at sites of inflammation and infection can alter the normal processes of cartilage turnover, resulting in pathologic destruction or formation. Interleukin (IL)-1beta plays a central role in the pathophysiology of cartilage damage and degradation in arthritis. In the present study, we examined the effect of IL-1beta on the expression of IL-1beta, IL-6, IL-8, IL-11, tumor necrosis factor-alpha (TNF-alpha), and their receptors in human chondrocytes. The cells were cultured either with or without 100 U/ml of IL-1beta for up to 28 days. The level of expression of the cytokines and their receptors was estimated by determining mRNA levels using real-time PCR or by determining protein levels using ELISA. The expression of IL-1beta, IL-8, and TNF-alpha markedly increased in the presence of IL-1beta after day 14 of culture. The expression of IL-6 and IL-11 increased greatly in the presence of IL-1beta on day 1 and after day 14 of culture. The expression of IL-1beta, IL-8, IL-11, and TNF-alpha receptors significantly decreased in the presence of IL-1beta after day 14 of culture, whereas the expression of IL-6 receptor significantly increased. The expression of these cytokines, except for IL-6, decreased with the addition of human IL-1 receptor antagonist. These results suggest that IL-1beta promotes the resolution system of cartilage matrix turnover through an increase in inflammatory cytokine production by chondrocytes and that it also may promote the autocrine action of IL-6 through an increase in IL-6 receptor expression in the cells.     

Relaxin causes changes of the liver. In vivo studies in rats.

During pregnancy, the liver undergoes metabolic adjustments directed to fulfil the needs of the mother and the growing fetus. This study was designed to verify whether relaxin, a hormone related to pregnancy, may induce histochemical and ultrastructural modifications of hepatocytes which can be related to metabolic changes. Estrogen-primed female rats were treated with relaxin (10 microg in repository vehicle) for 18 h. Additional male rats were treated with relaxin (10 microg/day in PBS) for 4 days. Appropriate vehicle-treated rats were used as controls. After fasting, the rats were killed and liver fragments were processed for light and electron microscopy and for computer-assisted morphometry of PAS-positive glycogen deposits and acid phosphatase-reactive organelles. In both sexes, the relaxin-treated rats underwent a significant decrease in the amount of glycogen in the hepatocytes as compared with the controls. These changes were accompanied by an increase in smooth endoplasmic reticulum, endocytosis vesicles and lysosomes. These findings show that relaxin promotes glycogen depletion and induces morphological changes of hepatocytes which are consistent with functional activation. It is suggested that relaxin might play an important role in hepatic metabolic adjustments occurring during pregnancy.     

Genotoxical, teratological and biochemical effects of anthelmintic drug oxfendazole Maximum Residue Limit (MRL) in male and female mice

Oxfendazole, methyl-5 (6)-phenylsulfinyl-2-benzimidazole carbamate, is a member of the benzimidazole family of anthelmintics. Anthelmintic benzimidazoles are widely used in meat producing animals (cattle, sheep and pigs) for control of endoparasites. The extensive use of veterinary drugs in food-producing animals can cause the presence of small quantities of the drug residues in food. Maximum residue limit or "MRL" means the maximum concentration of residue resulting from the use of a veterinary medicinal product which may be legally permitted recognized as acceptable in food. The FAO/WHO Expert Committee on Food Additives (1999) evaluations of toxicological and residue data, reported that oxfendazole (MRL) has toxicological hazards on human health. The toxicity of oxfendazole (MRL) was tested in male and female mice and their fetuses. Chromosomal aberrations, teratological examination and biochemical analysis were the parameters used in this study. The results show that oxfendazole MRL induced a mutagenic effect in all tested cell types. Also, oxfendazole exhibit embryotoxicity including teratogenicity. The biochemical results show that oxfendazole induced a disturbance in the different biochemical contents of all tested tissues. So, we must increase the attention paid to the potential risk of oxfendazole residues in human beings and should stress the need for careful control to ensure adherence to the prescribed withdrawal time of this drug.