30 research outputs found
The comparative osmoregulatory ability of two water beetle genera whose species span the fresh-hypersaline gradient in inland waters (Coleoptera: Dytiscidae, Hydrophilidae).
A better knowledge of the physiological basis of salinity tolerance is essential to understanding the ecology and evolutionary history of organisms that have colonized inland saline waters. Coleoptera are amongst the most diverse macroinvertebrates in inland waters, including saline habitats; however, the osmoregulatory strategies they employ to deal with osmotic stress remain unexplored. Survival and haemolymph osmotic concentration at different salinities were examined in adults of eight aquatic beetle species which inhabit different parts of the fresh-hypersaline gradient. Studied species belong to two unrelated genera which have invaded saline waters independently from freshwater ancestors; Nebrioporus (Dytiscidae) and Enochrus (Hydrophilidae). Their osmoregulatory strategy (osmoconformity or osmoregulation) was identified and osmotic capacity (the osmotic gradient between the animal's haemolymph and the external medium) was compared between species pairs co-habiting similar salinities in nature. We show that osmoregulatory capacity, rather than osmoconformity, has evolved independently in these different lineages. All species hyperegulated their haemolymph osmotic concentration in diluted waters; those living in fresh or low-salinity waters were unable to hyporegulate and survive in hyperosmotic media (> 340 mosmol kg(-1)). In contrast, the species which inhabit the hypo-hypersaline habitats were effective hyporegulators, maintaining their haemolymph osmolality within narrow limits (ca. 300 mosmol kg(-1)) across a wide range of external concentrations. The hypersaline species N. ceresyi and E. jesusarribasi tolerated conductivities up to 140 and 180 mS cm(-1), respectively, and maintained osmotic gradients over 3500 mosmol kg(-1), comparable to those of the most effective insect osmoregulators known to date. Syntopic species of both genera showed similar osmotic capacities and in general, osmotic responses correlated well with upper salinity levels occupied by individual species in nature. Therefore, osmoregulatory capacity may mediate habitat segregation amongst congeners across the salinity gradient
Transcutaneous treatment with vetdrop® sustains the adjacent cartilage in a microfracturing joint defect model in sheep
The significance of the adjacent cartilage in cartilage defect healing is not yet completely understood. Furthermore, it is unknown if the adjacent cartilage can somehow be influenced into responding after cartilage damage. The present study was undertaken to investigate whether the adjacent cartilage can be better sustained after microfracturing in a cartilage defect model in the stifle joint of sheep using a transcutaneous treatment concept (Vetdrop®).
Carprofen and chito-oligosaccharids were added either as single components or as a mixture to a vehicle suspension consisting of a herbal carrier oil in a water-in-oil phase. This mixture was administered onto the skin with the aid of a specific applicator during 6 weeks in 28 sheep, allocated into 6 different groups, that underwent microfracturing surgery either on the left or the right medial femoral condyle. Two groups served as control and were either treated intravenously or sham treated with oxygen only. Sheep were sacrificed and their medial condyle histologically evaluated qualitatively and semi-quantitatively according to 4 different scoring systems (Mankin, ICRS, Little and O’Driscoll).
The adjacent cartilage of animals of group 4 treated transcutaneously with vehicle, chito-oligosaccharids and carprofen had better histological scores compared to all the other groups (Mankin 3.3±0.8, ICRS 15.7±0.7, Little 9.0±1.4). Complete defect filling was absent from the transcutaneous treatment groups.
The experiment suggests that the adjacent cartilage is susceptible to treatment and that the combination of vehicle, chitooligosaccharids and carprofen may sustain the adjacent cartilage during the recovery period
Do risk factors explain the increased prevalence of type 2 diabetes among California Asian adults?
Asian subgroup-specific information on type 2 diabetes mellitus (DM) is scarce. Using the California Health Interview Survey 2007 data, we examined Chinese, Korean, Japanese, Filipinos, and Vietnamese adults (n = 3,688) and Caucasian adults (n = 33,981) for the prevalence of DM and risk factors. The age-adjusted prevalence of DM was the highest among Filipinos (8.05%) followed by Japanese (7.07%), Vietnamese (7.03%), and Koreans (6.3%). Chinese (5.93%) was the only Asian group studied whose prevalence was lower than Caucasians (5.94%). From multiple logistic regression, after adjusting for risk factors, Japanese had the highest likelihood of DM (OR = 1.75, CI = [1.12-2.73], P < 0.05), followed by Filipinos (1.66, [1.13-2.43], P < 0.01), and Koreans (1.59, [1.00-2.52], P < 0.05), relative to Caucasians. Our results suggest that even after accounting for lifestyle and other risk factor differences between Caucasians and key Asian subgroups in California, Japanese, Filipinos, and Koreans have a 1.6-1.75 greater likelihood of DM compared to Caucasians