Caudal Vessels Research Articles

Does blood sampling from caudal vessels in fish produce parameter values different from those obtained by heart puncture?

Analyses of blood samples in ichthyology are of importance for assessment of fish health as well as fish responses to environmental stressors. The measurement results may be affected by multiple factors. This study aimed at assessment of the influence of the blood collection site by comparing dual values of indices measured in samples obtained both from the heart and puncturing caudal vessels in the same fish specimens. Our results revealed that the sampling site did not significantly influence measured variables including haematological indices, the plasma biochemistry profile, acid-base balance parameters and the phagocytic activity. To conclude, for the rainbow trout (Oncorhynchus mykiss) both sampling methods are interchangeable with regard to the above-mentioned indices.

Hematology of Astyanax novae Eigenmann, 1911 (Characidae: Stethaprioninae) in Neblina stream, eastern Amazon, Brazil

This study aimed to identify and measure the hematological parameters (erythrogram, thrombogram, white blood cell count and plasma metabolites) of the species Astyanax novae Eigenmann, 1911, collected in the urban stream, Neblina river in the city of Araguaína – TO, Brazil. The captured animals totaled 60 individuals, which were collected with a cast net and with the aid of a rod and reel with artificial bait. Blood collections were performed by caudal puncture of the caudal blood vessels, and blood data were collected according to the methodology described in the bibliography. From the results of the hematological analysis, mean values were obtained, which were: Hematocrit (Ht): 12.0%; Hemoglobin (Hb): 3.6 g/dL and erythrocytes: (GV): 0.59 x 106/uL. The allusive of variations in these parameters may suggest indicators of contamination in the environment where these animals are inserted. And it is concluded that the immune responses presented by the differences between the results of these parameters are indicative of changes in the water quality of the Neblina stream.

Haemodynamic dependence of mechano-genetic evolution of the cardiovascular system in Japanese medaka.

The progression of cardiac gene expression-wall shear stress (WSS) interplay is critical to identifying developmental defects during cardiovascular morphogenesis. However, mechano-genetics from the embryonic to larval stages are poorly understood in vertebrates. We quantified peak WSS in the heart and tail vessels of Japanese medaka from 3 days post fertilization (dpf) to 14 dpf using in vivo micro-particle image velocimetry flow measurements, and in parallel analysed the expression of five cardiac genes (fgf8, hoxb6b, bmp4, nkx2.5, smyd1). Here, we report that WSS in the atrioventricular canal (AVC), ventricular outflow tract (OFT), and the caudal vessels in medaka peak with inflection points at 6 dpf and 10-11 dpf instead of a monotonic trend. Retrograde flows are captured at the AVC and OFT of the medaka heart for the first time. In addition, all genes were upregulated at 3 dpf and 7 dpf, indicating a possible correlation between the two, with the cardiac gene upregulation preceding WSS increase in order to facilitate cardiac wall remodelling.

Lysine-Histone Triggers Thrombotic Thrombocytopenic Purpura in Zebrafish and Mice

Background: Thrombotic thrombocytopenic purpura (TTP) is a potentially fatal syndrome, primarily resulting from a severe deficiency of plasma ADAMTS13 activity due to mutations in ADAMTS13 gene or autoantibodies against ADAMTS13. However, severe deficiency of plasma ADAMTS13 activity alone is often not sufficient to cause an acute episode; additional environmental and/or genetic factors may be required to trigger acute TTP.Objectives: To address the potential triggers and identify novel therapeutic targets for TTP, we established and characterized a novel Adamts13-/- zebrafish line and determined the pathogenic role of lysine-histone in triggering TTP in both zebrafish and mice.Methods and Results:CRISPR/Cas9 was employed to create an 8-nt deletion mutation in the signal peptide region of zebrafish Adamts13, resulting in complete deficiency of Adamts13 protein. Adamts13-/- zebrafish on the double transgenic (fli1-eGFP/gata1-dsRed) background showed normal size, morphology, and fertility except for the consistent appearance of a branching interseptal vessel. Adamts13-/- zebrafish larvae exhibited a significantly increased response to oxidative stress with an increased mortality rate and an accelerated rate of thrombus formation in microvasculature and caudal vessels after oxidative injury. Additionally, Adamts13-/- zebrafish demonstrated a significantly reduced number of circulating mature thrombocytes (thrombocytopenia) and an increased number of fragmented red blood cells (schistocytosis), consistent with the clinical phenotype of a spontaneous TTP. Moreover, plasma levels of histone/DNA complexes were found to be highly elevated in patients with acute TTP, but their pathogenic role is not known. Wild-Type and Adamts13-/- zebrafish and mice were challenged with a lysine rich-histone (H5505) intraperitoneally (200 μg/g body weight) and intravenously (20, 60, and 120 μg/g body weight), respectively. Complete blood counts were determined over a period of 14 and 3 days, respectively. We showed a more severe and persistent thrombocytopenia, increased fragmentation of red blood cells, as well as increased mortality rate in Adamts13-/- compared to Wild-Type zebrafish (Figure). Similar dose-dependent and profound thrombocytopenia was observed in Adamts13-/- but not in Wild-Type mice. Histological analysis of the organ tissues from Adamts13-/- zebrafish that died after histone challenge revealed the presence of microvascular thrombosis, supporting the diagnosis of TTP in these zebrafish.Conclusions: These results demonstrate for the first time the success in establishing a zebrafish model of Adamts13-/- and TTP. Such a novel animal model enables us to rapidly evaluate the role of lysine-histone and many other potential environmental or genetic factors in the onset, progression, and outcome of TTP. This model may also help to identify novel therapeutic targets for both hereditary and acquired TTP in at an unprecedented pace. [Display omitted] DisclosuresZheng:Alexion: Speakers Bureau; Ablynx: Consultancy.

A Sequence in Recipient-Site Selection in Stacked Free Flap Breast Reconstruction: Cranial and Caudal Internal Mammary Vessels prior to Other Alternatives

A Sequence in Recipient-Site Selection in Stacked Free Flap Breast Reconstruction: Cranial and Caudal Internal Mammary Vessels prior to Other Alternatives

Peculiarities of the Development of the Myocardial Infarction in ISIAH Rats.

We studied peculiarities of the development of myocardial infarction in rats with inherited stress-induced arterial hypertension (ISIAH rats). The control group consisted of Wistar rats. Occlusion of the left coronary artery (30 min) followed by reperfusion (120 min) was performed. The infarct size was determined relative to the risk zone by staining with 1% triphenyltetrazolium. BP, blood filling, and blood flow in the caudal vessels were measured. The infarct size was 31.5±3.0% of the risk zone in Wistar rats and 47.9±4.4% in ISIAH rats (p=0.026). No correlations of infarction size and BP or HR were found at the study stages. In ISIAH rats, local 30-min ischemia followed by 120-min reperfusion caused greater myocardial infarction that did not depend on BP or HR.

PEG-b-PCL polymeric nano-micelle inhibits vascular angiogenesis by activating p53-dependent apoptosis in zebrafish.

Micro/nanoparticles could cause adverse effects on cardiovascular system and increase the risk for cardiovascular disease-related events. Nanoparticles prepared from poly(ethylene glycol) (PEG)-b-poly(ε-caprolactone) (PCL), namely PEG-b-PCL, a widely studied biodegradable copolymer, are promising carriers for the drug delivery systems. However, it is unknown whether polymeric PEG-b-PCL nano-micelles give rise to potential complications of the cardiovascular system. Zebrafish were used as an in vivo model to evaluate the effects of PEG-b-PCL nano-micelle on cardiovascular development. The results showed that PEG-b-PCL nano-micelle caused embryo mortality as well as embryonic and larval malformations in a dose-dependent manner. To determine PEG-b-PCL nano-micelle effects on embryonic angiogenesis, a critical process in zebrafish cardiovascular development, growth of intersegmental vessels (ISVs) and caudal vessels (CVs) in flk1-GFP transgenic zebrafish embryos using fluorescent stereomicroscopy were examined. The expression of fetal liver kinase 1 (flk1), an angiogenic factor, by real-time quantitative polymerase chain reaction (qPCR) and in situ whole-mount hybridization were also analyzed. PEG-b-PCL nano-micelle decreased growth of ISVs and CVs, as well as reduced flk1 expression in a concentration-dependent manner. Parallel to the inhibitory effects on angiogenesis, PEG-b-PCL nano-micelle exposure upregulated p53 pro-apoptotic pathway and induced cellular apoptosis in angiogenic regions by qPCR and terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) apoptosis assay. This study further showed that inhibiting p53 activity, either by pharmacological inhibitor or RNA interference, could abrogate the apoptosis and angiogenic defects caused by PEG-b-PCL nano-micelles, indicating that PEG-b-PCL nano-micelle inhibits angiogenesis by activating p53-mediated apoptosis. This study indicates that polymeric PEG-b-PCL nano-micelle could pose potential hazards to cardiovascular development.

Seasonal, ontogenetic and sexual changes in lipid metabolism of the small-spotted catshark (Scyliorhinus canicula) in deep-sea free-living conditions

Marine predators, such as elasmobranchs, exhibit variations in nutritional conditions related to both reproductive traits and food availability in the marine environment throughout the year. The main objective of this study was to examine changes in several blood physiological parameters in a demersal shark, the small-spotted catshark (Scyliorhinus canicula), in the wild in relation to season, sex and maturity stage. For this purpose, 108 individuals at different developmental stages were captured and released alive in the western Mediterranean. Blood was obtained from caudal vessels and plasma lipid fractions (total cholesterol, triglycerides and phospholipids) and a ketone body (3-β-hydroxybutyrate) were measured. During summer, plasma triglyceride and phospholipid levels were lower in adults than in juveniles (mainly in females, probably related to breeding season and laying eggs). Plasma cholesterol levels also showed higher values in summer, indicating higher physical activities during summer and revealing that lipid fractions are more related to reproduction than to nutrition. Plasma 3-β-hydroxybutyrate variations showed a different pattern. No differences were found between sex or maturity stage during summer, although the highest values in adult and juvenile males during winter indicates higher physical activity of males. This study, uses an innovative methodology to establish a correlation between lipid fractions and ketone bodies from the blood of wild individuals and changes in sexual and nutritional status. This method was conducted without damage to the target species and provides new information on the physiology of this abundant elasmobranch in the Mediterranean Sea.

Mixed Epigastric Axial Pattern Flap Following Cutaneous Hemangiosarcoma Excision in a Male Dog

Background: Axial pattern flaps use direct cutaneous arteries to enable closure of a skin defect using a large skin segment. Caudal epigastric axial pattern flaps are highly versatile owing to their wide arc of rotation, which includes the preputial area. The presence of abundant loose and elastic skin allows wider flaps. Hemangiosarcoma (HSA) is a malignant neoplasm of endothelial cells with aggressive local behavior and high metastatic rate; the lungs are the most common site of metastasis. This case report aims to describe the use of a caudal epigastric artery-based flap, with preservation of some cranial epigastric artery branches for penis sparing, following resection of a hemangiosarcoma in the right inguinal region of a male dog.Case: An eight-year-old male Pitt Bull dog was referred with a 15 cm, ulcerated hemangiosarcoma in the right inguinal region, near the prepuce. A similar tumor had been removed from the same location two years before. Previous treatment with oral prednisone did not provide satisfactory results. The patient was suffering from intense chronic blood loss andbacterial infection of the tumor tissue. Thoracic radiographs revealed multiple metastatic nodules. Only mild regenerative anemia was found in blood tests. Considerable reductions in tumor size and in the ulcerated surface, decrease in bleeding, and recovery of appetite were observed after 7 days of administration of piroxicam and cephalexin. Surgical resectionof the tumor was performed as a palliative treatment with a minimal safety margin of 2 cm, which spared the penis. An epigastric skin flap incorporating the second mammary gland was performed preserving branches of cranial epigastric arteries, and was rotated 160° to cover the defect created in the right inguinal region and on the body of the penis. A small suture dehiscence, necrosis of the distal border of the flap, seroma, and multidrug-resistant Escherichia coli infection were observed in the postoperative period. Administration of penicillin V and topical collagenase, placement of a passive drain, and a second surgical procedure to correct the dehiscence were necessary to solve postoperative complications. Piroxicam based metronomic chemotherapy was maintained continuously, as the patient would exhibit worsening of overall condition upon discontinuation of medication. One hundred days after the initial presentation, the animal was euthanized owing to the presence of an osteolytic lesion on the vertebral bodies of L3-L4 and L5-L6, which were suggestive of discosponlylitis or axial bone metastasis.Discussion: Since lung metastases were present, penectomy and uretrostomy were not considered an option, and a pallia tive surgical treatment was performed. In this case report, cranial and caudal epigastric flap presented few complications. Caudal epigastric blood vessels are robust and abundant. Distal necrosis was considered a minor complication and was in accordance with others reports. The multidrug resistant infection was considered a nosocomial infection that arised from a long hospital stay. By inhibiting cyclooxygenase, piroxicam decreases angiogenesis, increases apoptosis, and prolongs disease-free intervals with mild toxicity. An excellent response to preoperative administration of piroxicam was crucial when choosing the postoperative protocol. A signifcant tumor size reduction and a decrease in chronic bleeding associated to improvement in general health were observed with the piroxicam-based treatment. To our knowledge, this is the frst report of a mixed (cranial and caudal) epigastric artery skin flap. This type of flap was considered a good option for correction of large defects in the inguinal region and for preservation of the prepuce and penis.Keywords: hemangiosarcoma, cranial, caudal, penis, sparing.

Hematology of Nile tilapia (Oreochromis niloticus) subjected to anesthesia and anticoagulation protocols

Clinical hematology facilitates the diagnosis of disease and can act as a prognostic indicator of pathological conditions in fish. The aim of the present study was to evaluate hematological parameters of Nile tilapia (Oreochromis niloticus) subjected to different anesthetics and anticoagulants. Thirty apparently healthy fishes (average weight of 473 ± 35. 50 g and mean total length of 29. 33 ± 0. 37 cm), were selected from the local commercial fish farm in the Lages municipality (Santa Catarina, Brazil). The animals were randomly divided into three groups of 10. In two groups, anesthesia was induced with eugenol (70 mg·L- 1) (EG) and Benzocaine hydrochloride (100 mg·L-1) (BG), respectively. Anesthesia was not administered to fish of the third group (CG/control group). Blood samples were obtained by venipuncture of the caudal vessels and placed into microtubes containing sodium heparin or Na2EDTA for further analysis. The results were analyzed by Sigma Stat for Windows, the paired t-test for significant differences between anticoagulants of the same group, and analysis of variance followed by the Tukey test for comparison of means between groups (p ? 0. 05). Most of the observed changes in the erythrogram were significantly higher for the anticoagulant heparin and benzocaine group in comparison to the control group. However, the values obtained for the leukogram were significantly higher for all groups subjected to the Na2EDTA anticoagulant, suggesting that heparin may cause cell clumping. The results suggest that the anesthetics under investigation effectively minimizes the effects of stress caused by handling and invasive procedures, and that the anticoagulant heparin causes less hemolysis in comparison to Na2EDTA for Nile tilapia. Thus, the hematological variations attributed to different anesthetic protocols and/or different anticoagulants should be considered for the species Oreochromis niloticus.

Hematology of Nile tilapia (Oreochromis niloticus) subjected to anesthesia and anticoagulation protocols

<p>Clinical hematology facilitates the diagnosis of disease and can act as a prognostic indicator of pathological conditions in fish. The aim of the present study was to evaluate hematological parameters of Nile tilapia (<em>Oreochromis niloticus</em>) subjected to different anesthetics and anticoagulants. Thirty apparently healthy fishes (average weight of 473 ± 35. 50 g and mean total length of 29. 33 ± 0. 37 cm), were selected from the local commercial fish farm in the Lages municipality (Santa Catarina, Brazil). The animals were randomly divided into three groups of 10. In two groups, anesthesia was induced with eugenol (70 mg·L- 1) (EG) and Benzocaine hydrochloride (100 mg·L-1) (BG), respectively. Anesthesia was not administered to fish of the third group (CG/control group). Blood samples were obtained by venipuncture of the caudal vessels and placed into microtubes containing sodium heparin or Na2EDTA for further analysis. The results were analyzed by Sigma Stat for Windows, the paired t-test for significant differences between anticoagulants of the same group, and analysis of variance followed by the Tukey test for comparison of means between groups (p ? 0. 05). Most of the observed changes in the erythrogram were significantly higher for the anticoagulant heparin and benzocaine group in comparison to the control group. However, the values obtained for the leukogram were significantly higher for all groups subjected to the Na2EDTA anticoagulant, suggesting that heparin may cause cell clumping. The results suggest that the anesthetics under investigation effectively minimizes the effects of stress caused by handling and invasive procedures, and that the anticoagulant heparin causes less hemolysis in comparison to Na2EDTA for Nile tilapia. Thus, the hematological variations attributed to different anesthetic protocols and/or different anticoagulants should be considered for the species <em>Oreochromis niloticus. </em></p>

Hematological and morphometric blood value of four cultured species of economically important tropical foodfish

The use and validation of fish health monitoring tools have become increasingly evident due to aquaculture expansion. This study investigated the hematology and blood morphometrics of Piaractus mesopotamicus, Brycon orbignyanus, Oreochromis niloticus and Rhamdia quelen. The fish were kept for 30 days in 300-liter aquariums, after which they were anesthetized with benzocaine and blood was collected from caudal vessels. In comparison to other species, B. orbignyanus presented the highest hematocrit (Ht), RBC averages and Mean Corpuscular Volume (MCV) with a particular range of data. B. orbignyanus presented lower Ht, Hb, RBC averages and values, and Mean Corpuscular Hemoglobin Concentration (MCHC). Oreochromis niloticus presented lower Ht, Hb, RBC averages and values, and Mean Corpuscular Hemoglobin Concentration (MCHC). Rhamdia quelen and O. niloticus presented higher variation of White Blood Cells (WBC), neutrophils (Nf), lymphocytes (Lf), monocytes (Mf) and thrombocytes (Trb). Data of large axes (LA), minor axes (MA), surface (SF) and volume (VL) are in the same variance range. This study has demonstrated that hematological variances can occur between animals of different species as well as of the same species.

Multiplane spectroscopic whole-body photoacoustic imaging of small animals in vivo.

We have successfully developed a multiscale acoustic-resolution photoacoustic tomography system in a single imaging platform. By switching between ultrasound transducers (center frequencies 5 and 40MHz) and optical condensers, we have photoacoustically imaged microvasculatures of small animals in vivo at different scales. Further, we have extended the field of view of our imaging system to entire bodies of small animals. At different imaging planes, we have noninvasively imaged the major blood vessels (e.g., descending aorta, intercostal vessels, cephalic vessels, brachial vessels, femoral vessels, popliteal vessels, lateral marginal vessels, cranial mesenteric vessels, mammalian vessels, carotid artery, jugular vein, subclavian vessels, iliac vessels, and caudal vessels) as well as intact internal organs (e.g., spleen, liver, kidney, intestine, cecum, and spinal cord) of the animals in vivo. The spectroscopic whole-body photoacoustic imaging clearly reveals the spectral responses of the internal structures. Similar to other existing preclinical whole-body imaging systems, this whole-body photoacoustic tomography can be a useful tool for small-animal research.

Visualizing the cell-cycle progression of endothelial cells in zebrafish

The formation of vascular structures requires precisely controlled proliferation of endothelial cells (ECs), which occurs through strict regulation of the cell cycle. However, the mechanism by which EC proliferation is coordinated during vascular formation remains largely unknown, since a method of analyzing cell-cycle progression of ECs in living animals has been lacking. Thus, we devised a novel system allowing the cell-cycle progression of ECs to be visualized in vivo. To achieve this aim, we generated a transgenic zebrafish line that expresses zFucci (zebrafish fluorescent ubiquitination-based cell cycle indicator) specifically in ECs (an EC-zFucci Tg line). We first assessed whether this system works by labeling the S phase ECs with EdU, then performing time-lapse imaging analyses and, finally, examining the effects of cell-cycle inhibitors. Employing the EC-zFucci Tg line, we analyzed the cell-cycle progression of ECs during vascular development in different regions and at different time points and found that ECs proliferate actively in the developing vasculature. The proliferation of ECs also contributes to the elongation of newly formed blood vessels. While ECs divide during elongation in intersegmental vessels, ECs proliferate in the primordial hindbrain channel to serve as an EC reservoir and migrate into basilar and central arteries, thereby contributing to new blood vessel formation. Furthermore, while EC proliferation is not essential for the formation of the basic framework structures of intersegmental and caudal vessels, it appears to be required for full maturation of these vessels. In addition, venous ECs mainly proliferate in the late stage of vascular development, whereas arterial ECs become quiescent at this stage. Thus, we anticipate that the EC-zFucci Tg line can serve as a tool for detailed studies of the proliferation of ECs in various forms of vascular development in vivo.

Hemoparasite and hematological parameters in Nile tilapia

The accelerated growth of finfish aquaculture has resulted in a series of health problems, including blood disorders by hemoparasites; there are scarce studies about these agents and their impact in actual intensive farming. The aim of this study was to identify and quantify the hemoparasites present in monocytes and erythrocytes in the blood of tilapia and their correlation with the hematological profile. Blood samples were collected from caudal vessels of 15 cage-reared Nile tilapia (Oreochromis niloticus), with 70 ± 10 g weight on average, from Itambaraca Municipality, Parana State, Brazil. The total red blood cells, mean corpuscular volume, hematocrit, total and differential white blood cells counts, and the number of thrombocytes were determined in blood smears stained with May-Grunwald–Giemsa–Wright and Quick Panoptic. The results showed the presence of pleomorphic cytoplasmic inclusions with corrugated appearance and basophilic staining, mainly in monocytes, suggesting Anaplasmataceae parasitemia and inclusions with the same morphological characteristics in erythrocytes of one Nile tilapia. The hematological analysis showed no significant difference (P < 0.05) between infected and not infected fish, and therefore, there was no correlation between parasitemia and hematological profile. These observations allow us to infer that the intracytoplasmic inclusions in monocytes and erythrocytes are compatible with the family Anaplasmataceae. There was no correlation between the blood profile and low level of parasitemia.

Variation in the branching pattern of the four major caudal vessels emerging from the external carotid artery

The branching pattern of vessels emerging from the external carotid artery (ECA) displays considerable variation. Knowledge of these variations is of particular interest to clinicians. Surprisingly, there are few reports in the literature assessing these differences with regard to gender and sidedness (i.e., branching patterns of the right vs. left neck). The objective of the current study was to assess the origin of the four primary caudal branches of the external carotid artery: the superior thyroid (STA), lingual (LA), facial (FA), and occipital (OA) arteries with regard to gender and side. Seventy‐three cadavers (35 male, 38 female) were studied (65 right necks, 62 left necks). We observed that the STA on the right side emerged from the ECA more frequently than it did from the common carotid artery (CCA) (28 and 20, respectively), however, on the left side, the STA emerged more frequently from the CCA than the ECA (34 and 19, respectively). We observed the LA and FA to arise individually more frequently than from a common trunk (right 72%, left 81%). We observed that the OA emerged below the origin of the FA more frequently than above (right 55%, left 64%). With regard to gender, branching pattern variation was similar for the vessels studied. We conclude that variation in the branching pattern is substantial regarding sidedness but not so regarding gender. This study was supported by the JMU Department of Biology.

A Chimeric Flap Model in Dogs

Prelamination is sometimes required for reconstruction of specialized organs. The purpose of this study was to create a chimeric flap model in dogs for prelamination. The anatomy of the deep and superficial caudal epigastric vessels, which supply the rectus abdominis muscle and superficial ventral fascia, respectively, were measured in 14 dogs. Their lengths were ~30 mm with the arteries averaging 1.4 mm and veins, 2.5 mm in diameter. These vessels shared a 10-mm-long common trunk with the artery averaging 2 mm and the vein, 3.2 mm in diameter. Chimeric flaps were successfully raised in six dogs based on the common vascular trunk, and they remained well perfused 3 weeks after prelamination. The perfusion territory of the abdominal skin measured 25 cm long and 10 cm wide with methylene blue injection. This study suggests that the caudal epigastric system can be a suitable chimeric flap model in dogs.

Physiological correlates of coastal arrival and river entry timing in late summer Fraser River sockeye salmon (Oncorhynchus nerka)

Animal migrations typically occur within a predictable time frame and sequence, but little is known about the triggers that initiate migration, despite their importance in animal ecology and for resource management. The migration of adult sockeye salmon (Oncorhynchus nerka) in the Fraser River, British Columbia, Canada, is an excellent model to study such triggers because for nearly a decade a segment of the late summer stocks has been proceeding into the river as much as 6 weeks earlier than the historic norm. In this study, late-run sockeye salmon (N = 146) were intercepted about 215 km from the mouth of the Fraser River and implanted with radio transmitters. These fish were biopsied, which included drawing blood from the caudal vessels, removing some gill filament tips, and quantifying energetic status using a microwave energy meter. Fish that entered the river without delaying in the estuary were in a more advanced state of reproductive maturation, as evidenced by hormone and energy levels. Indicators of osmoregulatory preparedness (i.e., plasma ions and gill Na 1 /K 1 -ATPase activity) provided little insight into migration timing aside from greater variation in Na 1 /K 1 -ATPase activity in fish that entered early relative to those that held in the ocean. Given the dissimilar reproductive hormone profiles for early arrival into the estuary and early entry into the Fraser River, it appears that only a subset of the population are early migrants and triggers for early migration may be related to a relatively advanced reproductive development and higher energetic status. These findings provide the first assessment of the physiological correlates of migration timing and provide a mechanistic understanding of the proximate factors associated with abnormal migration timing in late-run sockeye salmon. Key words: cues, energetics, migration behavior, timing. [Behav Ecol]

Axial Pattern Flap Based on the Lateral Caudal Arteries of the Tail in the Dog: An Experimental Study

To determine applicability and size limits of an axial pattern flap based on the lateral caudal arteries in dogs to reconstruct caudodorsal trunk skin defects. Experimental study. Ten mature, mixed breed dogs. The lateral caudal vessels of the tail were incorporated in the flaps of the treatment group (n=5) and were ligated in the control group (n=5). Flaps were rotated and placed into experimentally created caudodorsal skin defects on the trunk. The length and area of tissue that remained viable in each flap were determined. Mean (+/-SD) survival area (222.8+/-32.9 cm2) and length (25.1+/-4.5 cm) of vascularized flaps were significantly greater (P<.05) compared with control flaps (94.9+/-13.4 cm2 and 14.61+/-4.7 cm). Necrosis occurred in all control flaps, resulting in lower percentage flap area (48.8%) and length (47.1%) survival compared with vascularized flaps (78.1%, 77.5%). Axial pattern flap based on lateral caudal arteries of the tail was successfully elevated and transferred in a single procedure, with 78% survival for closure of large experimentally created caudodorsal trunk defects in dogs. Large cutaneous defects of the caudodorsal trunk area in dog could be reconstructed with tail axial pattern flap. Limitations in terms of size and changes in animal appearance have to be considered before flap elevation.

Expression and mapping of duplicate neuropilin-1 and neuropilin-2 genes in developing zebrafish

Previously, we described the isolation and characterization of the first zebrafish neuropilin gene, which we now call nrp1a, and found its protein to be a mediator of vascular endothelial growth factor (VEGF)-dependent angiogenesis [Proc. Natl Acad. Sci. USA 99 (2002) 10470]. Subsequently, we have isolated three other full-length neuropilin genes ( nrp1b, nrp2a, and nrp2b) and find that they map to independent zebrafish linkage groups. The nrp1s and nrp2s had differential spatio-temporal gene expression profiles with nrp1a being most prominent in the gut, brain, retina, hypochord, motorneurons, fin bud and mandibular cartilage, nrp1b in the brain, dorsal aorta, melanophores, ventral fin, and heart, nrp2a in the brain, retina, heart, and caudal vessels, and nrp2b in the brain, retina, gut, fin bud, melanophores, heart, and caudal vessels. In addition, we have identified an alternatively-spliced transcript of the nrp1b gene (denoted as nrp1b(s)) which is predicted to encode a soluble form of Nrp1b, containing only the a, b, and c extracellular domains. Transcript expression of nrp1b(s) was different from full-length nrp1b transcript, with prominence in the brain, developing mouth, heart, and fin bud. The NRP1s were tested for VEGF-binding ability. Both 125 kDa Nrp1a and 145 kDa Nrp1b bound 125I-labelled VEGFA 165. In summary, two nrp1 and two nrp2 genes, with expression patterns similar to higher vertebrates, have been isolated from zebrafish.