15 research outputs found

    Morfologia e Vascularização do Plexo Braquial no Rato Wistar

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    Introduction: The rat is probably the animal species most widely used in experimental studies on nerve repair. The aim of this work was to contribute to a better understanding of the morphology and blood supply of the rat brachial plexus. Material and Methods: Thirty adult rats were studied regarding brachial plexus morphology and blood supply. Intravascular injection and dissection under an operating microscope, as well as light microscopy and scanning electron microscopy techniques were used to define the microanatomy of the rat brachial plexus and its vessels. Results: The rat brachial plexus was slightly different from the human brachial plexus. The arterial and venous supply to the brachial plexus plexus was derived directly or indirectly from neighboring vessels. These vessels formed dense and interconnected plexuses in the epineurium, perineurium, and endoneurium. Several brachial plexus components were accompanied for a relatively long portion of their length by large and constant blood vessels that supplied their epineural plexus, making it possible to raise these nerves as flaps. Discussion: The blood supply to the rat brachial plexus is not very different from that reported in humans, making the rat a useful animal model for the experimental study of peripheral nerve pathophysiology and treatment. Conclusion: Our results support the homology between the rat and the human brachial plexus in terms of morphology and blood supply. This work suggests that several components of the rat brachial plexus can be used as nerve flaps, including predominantly motor, sensory or mixed nerve fibers. This information may facilitate new experimental procedures in this animal model

    Blood Supply to the Integument of the Abdomen of the Rat: A Surgical Perspective

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    BACKGROUND: Many fundamental questions regarding the blood supply to the integument of the rat remain to be clarified, namely the degree of homology between rat and humans. The aim of this work was to characterize in detail the macro and microvascular blood supply to the integument covering the ventrolateral aspect of the abdominal wall of the rat. METHODS: Two hundred five Wistar male rats weighing 250-350 g were used. They were submitted to gross anatomical dissection after intravascular colored latex injection (n = 30); conversion in modified Spalteholz cleared specimens (n=10); intravascular injection of a Perspex solution, and then corroded, in order to produce vascular corrosion casts of the vessels in the region (n = 5); histological studies (n = 20); scanning electron microscopy of vascular corrosion casts (n = 10); surgical dissection of the superficial caudal epigastric vessels (n = 100); and to thermographic evaluation (n = 30). RESULTS: The ventrolateral abdominal wall presented a dominant superficial vascular system, which was composed mainly of branches from the superficial caudal epigastric artery and vein in the caudal half. The cranial half still received significant arterial contributions from the lateral thoracic artery in all cases and from large perforators coming from the intercostal arteries and from the deep cranial epigastric artery. CONCLUSIONS: These data show that rats and humans present a great deal of homology regarding the blood supply to the ventrolateral aspect of the abdominal integument. However, there are also significant differences that must be taken into consideration when performing and interpreting experimental procedures in rats.info:eu-repo/semantics/publishedVersio

    Optimization of an Arterialized Venous Fasciocutaneous Flap in the Abdomen of the Rat

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    BACKGROUND: Although numerous experimental models of arterialized venous flaps (AVFs) have been proposed, no single model has gained widespread acceptance. The main aim of this work was to evaluate the survival area of AVFs produced with different vascular constructs in the abdomen of the rat. METHODS: Fifty-three male rats were divided into 4 groups. In group I (n = 12), a 5-cm-long and 3-cm-wide conventional epigastric flap was raised on the left side of the abdomen. This flap was pedicled on the superficial caudal epigastric vessels caudally and on the lateral thoracic vein cranially. In groups II, III, and IV, a similar flap was raised, but the superficial epigastric artery was ligated. In these groups, AVFs were created using the following arterial venous anastomosis at the caudal end of the flap: group II (n = 13) a 1-mm-long side-to-side anastomosis was performed between the femoral artery and vein laterally to the ending of the superficial caudal epigastric vein. In group III (n = 14), in addition to the procedure described for group II, the femoral vein was ligated medially. Finally, in group IV (n = 14), the superficial caudal epigastric vein was cut from the femoral vein with a 1-mm-long ellipse of adjacent tissue, and an end-to-side arterial venous anastomosis was established between it and the femoral artery. RESULTS: Seven days postoperatively, the percentage of flap survival was 98.89 ± 1.69, 68.84 ± 7.36, 63.84 ± 10.38, 76.86 ± 13.67 in groups I-IV, respectively. CONCLUSION: An optimized AVF can be produced using the vascular architecture described for group IV.info:eu-repo/semantics/publishedVersio

    A Model of Free Tissue Transfer: The Rat Epigastric Free Flap

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    Free tissue transfer has been increasingly used in clinical practice since the 1970s, allowing reconstruction of complex and otherwise untreatable defects resulting from tumor extirpation, trauma, infections, malformations or burns. Free flaps are particularly useful for reconstructing highly complex anatomical regions, like those of the head and neck, the hand, the foot and the perineum. Moreover, basic and translational research in the area of free tissue transfer is of great clinical potential. Notwithstanding, surgical trainees and researchers are frequently deterred from using microsurgical models of tissue transfer, due to lack of information regarding the technical aspects involved in the operative procedures. The aim of this paper is to present the steps required to transfer a fasciocutaneous epigastric free flap to the neck in the rat. This flap is based on the superficial epigastric artery and vein, which originates from and drain into the femoral artery and vein, respectively. On average the caliber of the superficial epigastric vein is 0.6 to 0.8 mm, contrasting with the 0.3 to 0.5 mm of the superficial epigastric artery. Histologically, the flap is a composite block of tissues, containing skin (epidermis and dermis), a layer of fat tissue (panniculus adiposus), a layer of striated muscle (panniculus carnosus), and a layer of loose areolar tissue. Succinctly, the epigastric flap is raised on its pedicle vessels that are then anastomosed to the external jugular vein and to the carotid artery on the ventral surface of the rat's neck. According to our experience, this model guarantees the complete survival of approximately 70 to 80% of epigastric flaps transferred to the neck region. The flap can be evaluated whenever needed by visual inspection. Hence, the authors believe this is a good experimental model for microsurgical research and training.info:eu-repo/semantics/publishedVersio

    MAMMALS IN PORTUGAL : A data set of terrestrial, volant, and marine mammal occurrences in P ortugal

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    Mammals are threatened worldwide, with 26% of all species being includedin the IUCN threatened categories. This overall pattern is primarily associatedwith habitat loss or degradation, and human persecution for terrestrial mam-mals, and pollution, open net fishing, climate change, and prey depletion formarine mammals. Mammals play a key role in maintaining ecosystems func-tionality and resilience, and therefore information on their distribution is cru-cial to delineate and support conservation actions. MAMMALS INPORTUGAL is a publicly available data set compiling unpublishedgeoreferenced occurrence records of 92 terrestrial, volant, and marine mam-mals in mainland Portugal and archipelagos of the Azores and Madeira thatincludes 105,026 data entries between 1873 and 2021 (72% of the data occur-ring in 2000 and 2021). The methods used to collect the data were: live obser-vations/captures (43%), sign surveys (35%), camera trapping (16%),bioacoustics surveys (4%) and radiotracking, and inquiries that represent lessthan 1% of the records. The data set includes 13 types of records: (1) burrowsjsoil moundsjtunnel, (2) capture, (3) colony, (4) dead animaljhairjskullsjjaws, (5) genetic confirmation, (6) inquiries, (7) observation of live animal (8),observation in shelters, (9) photo trappingjvideo, (10) predators dietjpelletsjpine cones/nuts, (11) scatjtrackjditch, (12) telemetry and (13) vocalizationjecholocation. The spatial uncertainty of most records ranges between 0 and100 m (76%). Rodentia (n=31,573) has the highest number of records followedby Chiroptera (n=18,857), Carnivora (n=18,594), Lagomorpha (n=17,496),Cetartiodactyla (n=11,568) and Eulipotyphla (n=7008). The data setincludes records of species classified by the IUCN as threatened(e.g.,Oryctolagus cuniculus[n=12,159],Monachus monachus[n=1,512],andLynx pardinus[n=197]). We believe that this data set may stimulate thepublication of other European countries data sets that would certainly contrib-ute to ecology and conservation-related research, and therefore assisting onthe development of more accurate and tailored conservation managementstrategies for each species. There are no copyright restrictions; please cite thisdata paper when the data are used in publications.info:eu-repo/semantics/publishedVersio

    Establishment and cryptic transmission of Zika virus in Brazil and the Americas

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    Transmission of Zika virus (ZIKV) in the Americas was first confirmed in May 2015 in northeast Brazil1. Brazil has had the highest number of reported ZIKV cases worldwide (more than 200,000 by 24 December 20162) and the most cases associated with microcephaly and other birth defects (2,366 confirmed by 31 December 20162). Since the initial detection of ZIKV in Brazil, more than 45 countries in the Americas have reported local ZIKV transmission, with 24 of these reporting severe ZIKV-associated disease3. However, the origin and epidemic history of ZIKV in Brazil and the Americas remain poorly understood, despite the value of this information for interpreting observed trends in reported microcephaly. Here we address this issue by generating 54 complete or partial ZIKV genomes, mostly from Brazil, and reporting data generated by a mobile genomics laboratory that travelled across northeast Brazil in 2016. One sequence represents the earliest confirmed ZIKV infection in Brazil. Analyses of viral genomes with ecological and epidemiological data yield an estimate that ZIKV was present in northeast Brazil by February 2014 and is likely to have disseminated from there, nationally and internationally, before the first detection of ZIKV in the Americas. Estimated dates for the international spread of ZIKV from Brazil indicate the duration of pre-detection cryptic transmission in recipient regions. The role of northeast Brazil in the establishment of ZIKV in the Americas is further supported by geographic analysis of ZIKV transmission potential and by estimates of the basic reproduction number of the virus

    Meningioma and Breast Cancer: Survival of Patients with Synchronous and Metachronous Meningioma and Breast Cancer

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    The prognosis of the association between Breast Cancer (BC) and Meningioma (M) is unknown. To evaluate the survival impact of tumor exposure sequence in patients with both tumors. Patients were divided in groups according to the tumors sequence: BC before M (group 1), synchronous BC + M (group 2) and BC after M (group 3). The SEER database was used. Demographics, meningioma and breast cancer variables were analyzed. The primary outcome was oncological survival. A total of 1715 patients were included (median follow-up:84 months). Group 2 had the shortest survival (median:32 months) and group 1 the longest (median:110 months). On the unadjusted analysis, group 2 had the shortest survival (HR:3.13, 95% CI 1.62-6.04) and adjusted analysis confirmed this finding (HR 3.11, 95% CI 1.58-6.19), with no statistical difference between the metachronous tumors groups. Increasing age (HR:1.13, 95% CI 1.11-1.15, p < 0.005) and grade III meningioma (HR:4.51, 95% CI 1.90-10.69, p < 0.005) were related with lower survival. Meningioma treatment had no influence on the survival (p > 0.05). The association between surgery and radiotherapy in BC treatment improved the outcome (HR 0.37, 95% CI 0.23-0.93, p < 0.05). Grade III meningioma and receptor hormonal status influenced synchronous tumors (p < 0.05) but had no influence on metachronous tumors survival (p > 0.05) on stratified analysis. Synchronous tumors were associated with lower survival. Increasing age had a negative influence on patient survival. Although surgery and radiotherapy for breast cancer had a positive influence in the outcome, meningioma treatment was not related with survival. Grade III meningioma and hormonal receptor status only influenced synchronous tumors patient survival.info:eu-repo/semantics/publishedVersio
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