Low but highly geographically structured genomic diversity of East Asian Eurasian otters and its conservation implications.

Populations of Eurasian otters Lutra lutra, one of the most widely distributed apex predators in Eurasia, have been depleted mainly since the 1950s. However, a lack of information about their genomic diversity and how they are organized geographically in East Asia severely impedes our ability to monitor and conserve them in particular management units. Here, we re-sequenced and analyzed 20 otter genomes spanning continental East Asia, including a population at Kinmen, a small island off the Fujian coast, China. The otters form three genetic clusters (one of L. l. lutra in the north and two of L. l. chinensis in the south), which have diverged in the Holocene. These three clusters should be recognized as three conservation management units to monitor and manage independently. The heterozygosity of the East Asian otters is as low as that of the threatened carnivores sequenced. Historical effective population size trajectories inferred from genomic variations suggest that their low genomic diversity could be partially attributed to changes in the climate since the mid-Pleistocene and anthropogenic intervention since the Holocene. However, no evidence of genetic erosion, mutation load, or high level of inbreeding was detected in the presumably isolated Kinmen Island population. Any future in situ conservation efforts should consider this information for the conservation management units.

Range map datasets for terrestrial vertebrates across Taiwan.

Accurate data describing the geographic distribution of specific species form the basis for effective conservation management policies. However, for most species the freely available distributional information is usually confined to either expert maps or purely theoretical maps constructed by using a variety of modeling frameworks. These maps usually do not provide enough resolution for conservation applications or do not accurately describe the current distribution status. In this study, we constructed a novel workflow designed to integrate data from various species distribution models and expert knowledge into a single unified modeling process. Under this workflow, we systematically constructed current distribution maps for a selection of terrestrial vertebrates found across Taiwan. We used species distribution modeling as the base and then aggregated multiple open datasets describing species occurrence and environmental factors as data sources. Thereafter, we estimated the primary broad-scale and high spatial resolution species range maps using the MaxEnt modeling algorithm, and then consulted experts on each taxa to refine these maps. This dataset provides up-to-date species distribution maps for 379 terrestrial vertebrates in Taiwan, with members from across four taxa (27 amphibians, 52 reptiles, 264 birds, and 36 mammals). This dataset helps to fill the spatial knowledge gaps for conservation concerns and improves our understanding of the geographic distribution of more than half (61%) of the vertebrate species of Taiwan. Furthermore, by stacking the range maps of multiple species, we can identify vertebrate diversity hotspots and identify priority areas for conservation.

Rabies Virus Infection in Ferret Badgers (Melogale moschata subaurantiaca) in Taiwan: A Retrospective Study.

Fifteen ferret badgers (Melogale moschata subaurantiaca), collected 2010-13 and stored frozen, were submitted for rabies diagnosis by direct fluorescent antibody test and reverse transcription PCR. We detected seven positive animal samples, including some from 2010, which indicated that the ferret badger population in Taiwan had been affected by rabies prior to 2010.

Mobilization of Endothelial Progenitor Cells Following Creation of Arteriovenous Access in Patients with End-Stage Renal Disease.

BACKGROUND: A patent arteriovenous (AV) fistula induces activation of regional vascular endothelium and vascular shear force. Shear stress is an important physiological force in mobilizing endothelial progenitor cells (EPCs). This study aimed to explore the perioperative changes of circulating EPC levels for patients who require hemodialysis and underwent radiocephalic fistula operation. METHODS: This prospective cohort study included patients who received a radiocephalic fistula surgery when they were between 25 and 65 years of age. The subjects were followed for 90 days postoperatively for any stenotic events or immaturity of the fistula. Blood samples were obtained on the day before surgery and at postoperation day (POD) 3 and 30. CD133+/KDR+ cells, defined as EPCs, were analyzed using flow cytometry. Blood flow of the fistula was followed on POD 3 and 30. RESULTS: A total of 30 patients were enrolled in the study from July 2009 to December 2011. One patient dropped out of the study and seven patients developed a stenotic (or immature) AV fistula (7/29, 24.1%). There were positive linear relationships between EPC numbers and shear rate postoperatively, which were more significant on POD 30. In addition, postoperative mobilization of EPCs was significantly higher in patients who developed a stenotic fistula than those without. CONCLUSIONS: The mobilization of circulating EPCs correlated with a compromised arteriovenous fistula. The biological significance of increased EPC numbers need to be determined in future studies. KEY WORDS: Arteriovenous fistula; Endothelial progenitor cells.

Preconditioning renoprotective effect of isoflurane in a rat model of virtual renal transplant.

BACKGROUND: The development of warm-cold ischemia-reperfusion (IR) injury of the kidney grafts is inevitable during renal transplantation. However, there is currently no definite renoprotective strategy available in the protection of the graft tissue. In the present study, we compared the renal protection of preconditioning isoflurane with N-acetylcysteine (NAC) in a novel rat model of warm-cold renal IR injury. MATERIALS AND METHODS: Adult Sprague-Dawley rats were randomly assigned to receive inhaled isoflurane (1.5% for 2 h), NAC (1 g/kg, intra-arterial injection) or placebo before the induction of brief warm ischemia (10 min) followed by cold ischemia (45 min) periods. Plasma levels of creatinine and tissue inflammatory reaction in the kidney were analyzed 72 h after reperfusion. RESULTS: Elevated plasma level of creatinine and urea indicated the development of acute renal injury secondary to IR injury. The creatinine levels were reduced in animals pretreated with inhaled isoflurane and NAC, and the level was more significantly decreased in the isoflurane-treated group. Preconditioning with volatile isoflurane also significantly suppressed the tissue myeloperoxidase activity and expression of the inducible nitric oxide synthase. Immunostaining confirmed that myeloperoxidase expression was most significantly attenuated in the glomerulus and peritubular capillaries of rats pre-exposed to isoflurane. CONCLUSIONS: We present the first study demonstrating that the administration of volatile isoflurane before induction of experimental warm-cold renal IR injury provides preconditioning renoprotective effect, which is superior to the treatment with NAC. The beneficial renoprotective effect of isoflurane is most likely mediated by attenuation of proinflammatory reaction in the injured kidney.

Rosuvastatin suppresses the oxidative response in the venous limb of an arteriovenous fistula and enhances the fistula blood flow in diabetic rats.

OBJECTIVE: The blood flow in the arteriovenous (AV) fistula is significantly reduced in diabetic patients. Statins are known to mediate pleiotropic effects in the vascular endothelium and attenuate inflammatory responses. This study tested the vascular protective effect of rosuvastatin in an experimental model of AV fistula. METHODS: One week after the induction of diabetes mellitus (DM) in rats, a fistula was created in the abdominal aorta and inferior vena cava. Rats received placebo or rosuvastatin (15 mg/kg/day) in chow for 2 weeks. The blood flow in the venous segments of the fistula was measured. The expression of proinflammatory genes and the generation of superoxide in the venous fistula were examined. RESULTS: The blood flow and luminal diameter of the AV fistula was significantly enhanced in animals treated with rosuvastatin. Rosuvastatin attenuated the expression of inducible nitric oxide synthase, NADPH oxidase, and monocyte chemotactic protein-1 in the fistula. The levels of superoxide anions and proinflammatory cytokines were also suppressed in rosuvastatin-treated animals. Neointimal formation in the AV fistula was not affected following treatment with rosuvastatin. CONCLUSIONS: We demonstrated that rosuvastatin improves luminal dilatation and blood flow in the AV fistula of subjects with DM. These vascular protective effects of rosuvastatin are most likely mediated by the attenuation of proinflammatory activities in the remodeled vasculature.

Insular variation of the craniodental morphology in the Siberian weasel Mustela sibirica.

We compared craniodental morphology among 5 populations of the Siberian weasel Mustela sibirica including 2 insular ones (Tsushima and Taiwan). Skulls of the insular individuals tended to be smaller than those of continental ones. Shape differences were also detected, but not so pronounced. Considering these results, the Taiwan population should be regarded as a distinct subspecies M. s. taivana from the mainland ones. The Tsushima population may also possibly be a distinct subspecies from the mainland ones, but more detailed studies using a larger number of specimens are needed for a conclusion. The introduced population in Honshu is also differentiated from the source population. This suggests a high morphological plasticity in M. sibirica.

The preconditioning pulmonary protective effect of volatile isoflurane in acute lung injury is mediated by activation of endogenous iNOS.

PURPOSE: There is still a lack of evidence to support the use of specific anesthetic agents during major operations that could affect the development of postoperative acute lung injury (ALI). This study determined the protective effect of inhaled isoflurane in a rat model of endotoxin-induced ALI. METHODS: Rats were exposed to volatile isoflurane (1.5 % in oxygen) or pure oxygen via a facemask for 2 h. After a 3-h recovery period, rats were reanesthetized and ALI was induced by intratracheal instillation of lipopolysaccharide (LPS, 1 mg/kg in 0.5 ml saline). In some animals, a specific inducible nitric oxide synthase (iNOS) inhibitor, 1400W, (10 mg/kg, i.p.) was administered before exposure to isoflurane. Animals were sacrificed 12 h later for analysis. Pulmonary artery vasomotor function and alveolocapillary permeability were assessed. Expression of iNOS and CD11b, and activity of myeloperoxidase in the lung were analyzed. RESULTS: The maximal relaxation response to acetylcholine was significantly potentiated in rats pretreated with isoflurane. Lung wet-to-dry ratio was reduced in the lung of isoflurane-treated animals. Expression of iNOS and CD11b were attenuated in the lung tissue obtained from rats receiving isoflurane. Furthermore, enzymatic activity of myeloperoxidase was also reduced in the lung preexposed to isoflurane. However, these pulmonary protective effects of isoflurane were significantly abolished by pretreatment with 1400W. CONCLUSION: Pretreatment with volatile isoflurane attenuated inflammatory process in the lung tissue of rats with LPS-induced ALI, and this preconditioning pulmonary protective effect was mainly mediated by activation of endogenous iNOS in the lung.

Rosuvastatin improves vascular function of arteriovenous fistula in a diabetic rat model.

OBJECTIVE: This study investigates the pathogenesis of arteriovenous (AV) fistula failure in patients with diabetes mellitus (DM) and tests the vascular protective effect of rosuvastatin on the fistulous communication of diabetic rats. METHODS: DM was induced in rats by a single injection of streptozotocin. One week later, a fistula was created in the descending aorta and the adjacent inferior vena cava (aortocaval [AC] fistula). Rats were then randomly assigned to receive placebo or rosuvastatin (15 mg/kg/d) in chow for 2 weeks. Blood flow in the aortic segments of the fistula was measured. Circulating CD34+/KDR+ endothelial progenitor cells (EPCs) were determined 2 weeks after creation of the AC fistulas using flow cytometry. Vascular function of the AC fistulas was assessed by isometric force testing. The expression of proinflammatory genes and generation of superoxide anions in the fistulas were examined. RESULTS: The number of EPCs was reduced in diabetic rats, and rosuvastatin significantly increased the number of circulating EPCs. Reduced blood flow and impaired endothelium-dependent relaxation in the AC fistula of animals with diabetes was significantly potentiated after treatment with rosuvastatin. Rosuvastatin also attenuated the expression of inducible nitric oxide synthase and nicotinamide adenine dinucleotide phosphate oxidase and generation of superoxide anions in the fistula tissues isolated from diabetic rats. CONCLUSIONS: We provide the first evidence demonstrating that rosuvastatin improves blood flow and endothelial function of AC fistulas in rats with DM by attenuating the activity of proinflammatory genes and generation of superoxide anions in the remodeled vasculature. CLINICAL RELEVANCE: Arteriovenous (AV) fistula is the most common vascular access for hemodialysis in patients with end-stage renal disease. Studies have shown that blood flow in the AV fistula is significantly reduced in patients with diabetes and the period for maturation of an AV fistula is longer in these patients. The underlying mechanisms of AV fistula failure in diabetes are still poorly understood and there are limited therapeutic approaches that can increase the lifespan of these fistulas. The present study demonstrates that oral administration rosuvastatin improves blood flow and endothelial function of AC fistulas in rats with diabetes, which results from attenuating the activity of proinflammatory genes in the remodeled vasculature, thereby reducing the generation of tissue superoxide anions. Our results may thus enhance our ability to prevent and manage vascular access failure in patients with diabetes with chronic renal disease.

Cardiovascular protection of activating KATP channel during ischemia-reperfusion acidosis.

In clinical practice, prolonged occlusion of main arteries causes accumulation of metabolic waste and lactate. Reperfusion of blood flow is usually accompanied by circulatory shock. This study investigates the molecular mechanisms responsible for acidosis-induced hypotension and proposes therapeutic strategies for improving hemodynamic stability following ischemia-reperfusion acidosis. Vasomotor function of aortic rings was studied after cumulative addition of HCl in organ chambers (pH 7.4-7.0). Cultured vascular smooth muscle cells (VSMCs) were exposed to acidic buffer, and intracellular Ca levels were determined with Fluo3-AM. In an in vivo experiment, rat aorta was cross-clamped for 45 min and followed by declamping. Hemodynamic changes were measured in the presence and absence of an ATP-sensitive K channel (KATP channel) antagonist PNU37883A (3 mg/kg). Acidosis induced vasorelaxation in a dose-dependent manner, which was significantly attenuated by a KATP antagonist glibenclamide. Inhibition of KATP channel increased intracellular Ca load in the cultured VSMCs. Pretreatment with PNU37883A significantly attenuated systemic hypotension following reperfusion. However, systemic antagonism of KATP channel significantly increased the overall mortality. Recording of electrocardiogram showed progressive development of bradyarrhythmia with ST-segment elevation in animals pretreated with PNU37883A before reperfusion. We demonstrate that acidosis-induced vasodilation is, in part, mediated by the activation of KATP channels through reduction of intracellular Ca in VSMCs. However, systemic antagonism of KATP channel significantly increases the overall mortality secondary to the development of cardiac dysrhythmia in animals with profound experimental metabolic acidosis, suggesting that activation of KATP channel is a protective response during reperfusion acidosis.

Inhibition of cyclooxygenase-2 modulates phenotypic switching of vascular smooth muscle cells during increased aortic blood flow.

This study investigates the interactions between cyclooxygenase (COX-2) and vascular smooth muscle cell (VSMC) phenotypic switching, the two important coupling mechanisms of the vasculature on arterial remodeling in response to high laminal shear stress. High aortic blood flow was induced by creating a fistula in the abdominal aorta and the adjacent IVC of anesthetized rats. Celecoxib, a selective COX-2 inhibitor (25 mg/kg/day), was fed in the chow, and animals were killed 8 weeks later. Blood flow, vasoreactivity and morphological changes in the aorta proximal to the fistula were measured. Concentrations of collagen, expression of desmin and smooth muscle myosin heavy chain (SM-MHC)-II in the aorta were determined. Celecoxib significantly increased aortic blood flow and reduced the contraction responses of aorta. Decreased medial thickness, presence of intimal thickening and derangement of elastic lamina were found in the aortic section of celecoxib-treated animals. Celecoxib significantly reduced the tissue content of collagen and upregulated expression of SM-MHC-II and desmin in the high-flow aorta. Inhibition of COX-2 enzymatic activity in the aorta exposed to higher blood flow resulted in increased blood flow and vascular remodeling. These functional changes were accomplished by VSMC phenotypic switching and reduced biosynthesis of collagen.

Functional dilatation and medial remodeling of the renal artery in response to chronic increased blood flow.

BACKGROUND/AIMS: Renal blood flow (RBF) is tightly regulated by several intrinsic pathways in maintaining optimal kidney blood supply. Using a rat model of aortocaval (AC) fistula, we investigated remodeling of the renal artery following prolonged increased blood flow. METHODS: An AC fistula was created in the infrarenal aorta of anesthetized rats, and changes of blood flow in the renal artery were assessed using an ultrasonic flow probe. Morphological changes and expression of endothelial nitric oxide synthase and matrix metalloproteinase-2 in the remodeled renal artery were analyzed. RESULTS: Blood flow in the renal artery increased immediately after creation of AC fistula, but normal RBF was restored 8 weeks later. The renal artery dilated significantly 8 weeks after operation. Expression of endothelial nitric oxide synthase and matrix metalloproteinase-2 was upregulated shortly after blood flow increase, and returned to baseline levels after 3 weeks. Histological sections showed luminal dilatation with medial thickening and endothelial cell-to-smooth muscle cell attachments in the remodeled renal artery. CONCLUSION: Increased RBF was accommodated by functional dilatation and remodeling in the medial layer of the renal artery in order to restore normal blood flow. Our results provide important mechanistic insight into the intrinsic regulation of the renal artery in response to increased RBF.

Origins and founder effects on the Japanese masked palm civet Paguma larvata (Viverridae, Carnivora), revealed from a comparison with its molecular phylogeography in Taiwan.

The source areas of the Japanese populations of the masked palm civet Paguma larvata (Viverridae, Carnivora), an alien species in Japan, have not been identified. In the present study, to reveal their origins and genetic features, we determined the full mitochondrial DNA cytochrome b sequences (1,140 base-pairs) of a total of 206 individuals of P. larvata from the Honshu and Shikoku islands of Japan (186 animals) and Taiwan (20 animals), and investigated their molecular phylogeography and the genetic relationships between populations in these countries. We found that each animal from Japan exhibited one of four haplotypes (JA1, JA2, JA4, and JA5), and that JA1 and JA4 were more frequent in eastern Honshu and Shikoku-central Honshu, respectively. By contrast, six haplotypes consisting of four new types (TW1, TW2, TW3, and TW4) and the previously reported two types (JA1 and JA4) were identified from 20 animals from native populations in Taiwan. Within Taiwan, one haplotype set (JA1, TW1, and TW2) was distributed in the western region, while a second (JA4, TW3, and TW4) was found in the eastern region; these regions are separated by high mountain ranges. Our comparison of haplotype distributions strongly demonstrated that the eastern Japanese populations originated from animals of western Taiwan, and that the western Japanese populations originated from those of eastern Taiwan. In addition, the lower genetic variability and particular distribution patterns of haplotypes in Japan showed founder effects, which may have resulted from multiple introductions of P. larvata to Japan from Taiwan.