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1.
J Infus Nurs ; 47(4): 249-254, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38968587

RESUMO

Venipuncture for blood collection is frequently delegated to medical or nursing students, while their individual skills depend on the quality of teaching. The aim of this study was to evaluate the use of a near infrared imaging (NIR) system on the visualization of veins and its potential benefit for the education of medical personnel. Participants answered a questionnaire following standardized venipuncture for blood sampling with the help of an NIR device. Vein visibility with the NIR device and its ability to facilitate venipuncture were examined. Visibility of veins was significantly better with the NIR, and its direction was clearly delineated. Sixty-nine percent of the participants stated that they felt more secure with venipuncture after using the NIR device. Patients' individual factors limited the visibility of veins. The adjuvant use of an NIR system for venipuncture improves participants' subjective skills through visualization of veins and their direction.


Assuntos
Flebotomia , Estudantes de Enfermagem , Humanos , Feminino , Hospitais Universitários , Masculino , Adulto , Competência Clínica , Veias/anatomia & histologia , Veias/diagnóstico por imagem , Inquéritos e Questionários , Hospitais de Ensino
3.
World J Urol ; 42(1): 407, 2024 Jul 11.
Artigo em Inglês | MEDLINE | ID: mdl-38990349

RESUMO

BACKGROUND: Short harvested right renal veins (RV) are quite common in living donor kidney transplantation (KT). This technical difficulty might interfere implanting and increase warm ischemic time. Several techniques to overcome this problem have been applied, including iliac vein transposition, inverted transplant, synthetic graft, saphenous vein… Application of accompanying gonadal vein (GV), which is easily approachable and less time-consuming, has been recently published. This study aims to evaluate its effectiveness and safety. METHODS: Retrospective study on KT using the gonadal vein to lengthen the short right renal vein at Viet Duc University Hospital from April 2019 to April 2022. The following data were gathered: baseline characteristics, vascular imaging in CT scan/after nephrectomy and after reconstruction (mm), reconstruction and surgical time, hospitalization days. The outcomes were determined by kidney function after transplantation (plasma creatinine, creatinine clearance) and related complications. RESULTS: Twenty-five cases with procured right kidney with short RV from the living donor which were reconstructed and lengthened by the accompanying GV were collected. The additional length of RV was 15.9 ± 2.4 mm. Average cold ischemic time, venoplasty time, warm ischemic time were 60.4 ± 8.2, 21.2 ± 5.3, and 38.1 ± 5.6 min, respectively. The average hospital stay was 15.3 ± 3.2 days. Average follow-up time was 31 ± 5.2 months, creatinine clearance was around 60 ml/min after 1 year, no vascular or urologic complications was observed. CONCLUSION: Accompanying GV from a living donor to lengthen short right RV in KT is a feasible, safe, and effective technique.


Assuntos
Transplante de Rim , Doadores Vivos , Veias Renais , Humanos , Transplante de Rim/métodos , Estudos Retrospectivos , Masculino , Feminino , Adulto , Veias Renais/cirurgia , Pessoa de Meia-Idade , Resultado do Tratamento , Coleta de Tecidos e Órgãos/métodos , Veias , Nefrectomia/métodos
4.
Sci Rep ; 14(1): 13287, 2024 06 10.
Artigo em Inglês | MEDLINE | ID: mdl-38858395

RESUMO

Clinical outcomes of arteriovenous fistulae (AVF) for hemodialysis remain inadequate since biological mechanisms of AVF maturation and failure are still poorly understood. Aortocaval fistula creation (AVF group) or a sham operation (sham group) was performed in C57BL/6 mice. Venous limbs were collected on postoperative day 7 and total RNA was extracted for high throughput RNA sequencing and bioinformatic analysis. Genes in metabolic pathways were significantly downregulated in the AVF, whereas significant sex differences were not detected. Since gene expression patterns among the AVF group were heterogenous, the AVF group was divided into a 'normal' AVF (nAVF) group and an 'outliers' (OUT) group. The gene expression patterns of the nAVF and OUT groups were consistent with previously published data showing venous adaptive remodeling, whereas enrichment analyses showed significant upregulation of metabolism, inflammation and coagulation in the OUT group compared to the nAVF group, suggesting the heterogeneity during venous remodeling reflects early gene expression changes that may correlate with AVF maturation or failure. Early detection of these processes may be a translational strategy to predict fistula failure and reduce patient morbidity.


Assuntos
Derivação Arteriovenosa Cirúrgica , Camundongos Endogâmicos C57BL , Remodelação Vascular , Animais , Camundongos , Masculino , Remodelação Vascular/genética , Feminino , Regulação para Baixo/genética , Veias/metabolismo , Diálise Renal , Fístula Arteriovenosa/genética , Fístula Arteriovenosa/metabolismo , Fístula Arteriovenosa/patologia , Regulação da Expressão Gênica , Perfilação da Expressão Gênica
5.
J Plast Reconstr Aesthet Surg ; 94: 223-228, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38823078

RESUMO

BACKGROUND: Although the usefulness of lymphaticovenous anasotmosis (LVA) for lymphedema has been reported, it is difficult to determine where the LVA is to be performed, especially for inexperienced surgeons. This study aimed to establish a map of the LVA site. METHOD: A total of 105 limbs from 64 patients who underwent lower limb LVA were retrospectively reviewed. Multi-lymphosome indocyanine green (ICG) lymphography (in 35 patients) and lymphatic ultrasound (in all patients) were performed preoperatively and the incision site was determined where dilated lymph vessels and appropriate veins were located in close proximity. The LVA location was identified using a post-operative photograph. Additionally, the degree of lymphatic degeneration at the LVA site was recorded based on the normal, ectasis, contraction, and sclerosis type (NECST) classification. RESULT: A total of 206 skin incisions were analyzed. Among them, 161 (75.9%) were medial and 45 (21.2%) were lateral. Among the 85 sites on the calf, 52 (61.2%) were medial and 33 (38.8%) were lateral. Among the 117 sites on the thigh, 106 (90.6%) were medial and 11 (9.4%) were lateral. As the severity of lymphedema progressed, the probability of performing LVA on the lateral calf increased. Among the 202 locations where LVA was performed on the thigh and lower leg, ectasis type was found in 164 sites (81.2%). CONCLUSION: We established an LVA map of the legs based on multi-lymphosome ICG lymphography and lymphatic ultrasound data. Using this LVA map, surgeons can easily predict the location of lymph vessels, thereby improving the success rate of LVA.


Assuntos
Anastomose Cirúrgica , Verde de Indocianina , Vasos Linfáticos , Linfedema , Linfografia , Humanos , Linfografia/métodos , Linfedema/diagnóstico por imagem , Linfedema/cirurgia , Vasos Linfáticos/diagnóstico por imagem , Vasos Linfáticos/cirurgia , Feminino , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Anastomose Cirúrgica/métodos , Idoso , Adulto , Ultrassonografia/métodos , Corantes , Extremidade Inferior/cirurgia , Extremidade Inferior/diagnóstico por imagem , Extremidade Inferior/irrigação sanguínea , Veias/diagnóstico por imagem , Veias/cirurgia , Idoso de 80 Anos ou mais
6.
J Clin Hypertens (Greenwich) ; 26(6): 635-644, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38751037

RESUMO

During our previous bilateral adrenal vein sampling (AVS) procedure, the authors observed that accessing the left adrenal vein through the antecubital vein was more feasible than the conventional femoral vein. Meanwhile, the femoral vein pathway facilitated access to the right adrenal vein than the antecubital vein pathway. Therefore, the authors hypothesized that simultaneous bilateral AVS via the antecubital combined with the femoral vein pathway could improve the success rate. A total of 94 cases of AVS via the antecubital combined with the femoral vein pathway were performed, while the remaining 20 cases employed the antecubital vein pathway at our center between August 2020 and April 2023. Furthermore, a meta-analysis was conducted in this study using 15 selected articles to determine the success rate of AVS in each center and pathway. The success rate of ACTH-stimulated simultaneous bilateral AVS via the antecubital vein combined with the femoral vein pathway was 92.85% (P = .503) on the right and 95.00% (P < .001) on the left. In the antecubital vein pathway, the success rates were only 25.00% (P < .001) on the right side and 80.00% (P = .289) on the left side. The results of meta-analysis demonstrated a success rate of 78.16% on the right and 94.98% on the left for ACTH-stimulated AVS via the femoral vein pathway. Based on our center's experience, simultaneous bilateral adrenal vein sampling via the combined pathway could improve the success rate of AVS in the short term and shorten the learning curve.


Assuntos
Glândulas Suprarrenais , Veia Femoral , Curva de Aprendizado , Humanos , Glândulas Suprarrenais/irrigação sanguínea , Masculino , Feminino , Pessoa de Meia-Idade , Adulto , Veias , Hormônio Adrenocorticotrópico/sangue , Coleta de Amostras Sanguíneas/métodos
8.
Forensic Sci Int ; 360: 112050, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38761549

RESUMO

Forensic identification using vein patterns in standard colour images presents significant challenges due to their low visibility. Recent efforts have employed various computational techniques, including artificial neural networks and optical vein disclosure, to enhance vein pattern detection. However, these methods still face limitations in reliability when compared to Near-Infrared (NIR) reference images. One of the biggest challenges of the studies is the limited number of available datasets that have synchronised colour and NIR images from body limbs. This paper introduces a new dataset comprising 602 pairs of synchronised NIR and RGB forearm images from a diverse population, ethically approved and collected in Auckland, New Zealand. Using this dataset, we also propose a conditional Generative Adversarial Networks (cGANs) model to translate RGB images into their NIR equivalents. Our evaluations focus on matching accuracy, vein length measurements, and contrast quality, demonstrating that the translated vein patterns closely resemble their NIR counterparts. This advancement offers promising implications for forensic identification techniques.


Assuntos
Identificação Biométrica , Redes Neurais de Computação , Veias , Humanos , Nova Zelândia , Identificação Biométrica/métodos , Veias/diagnóstico por imagem , Veias/anatomia & histologia , Feminino , Masculino , Adulto , Pessoa de Meia-Idade , Adulto Jovem , Processamento de Imagem Assistida por Computador , Conjuntos de Dados como Assunto , Idoso , Cor , Adolescente
9.
BMJ Case Rep ; 17(5)2024 May 14.
Artigo em Inglês | MEDLINE | ID: mdl-38749516

RESUMO

We present the first-in-human robot-assisted microsurgery on a lymphocele in the groin involving a man in his late 60s who had been coping with the condition for 12 months. Despite numerous efforts at conservative treatment and surgical intervention, the lymphocele persisted, leading to a referral to our clinic.Diagnostic techniques, including indocyanine green lymphography and ultrasound, identified one lymphatic vessel draining into the lymphocele. The surgical intervention, conducted with the assistance of a robot and facilitated by the Symani Surgical System (Medical Microinstruments, Calci, Italy), involved a lymphovenous anastomosis and excision of the lymphocele. An end-to-end anastomosis was performed between the lymphatic and venous vessels measuring 1 mm in diameter, using an Ethilon 10-0 suture.The surgery was successful, with no postoperative complications and a prompt recovery. The patient was discharged 3 days postoperatively and exhibited complete recovery at the 14-day follow-up. This case marks the first use of robot-assisted microsurgical lymphovenous anastomosis to address a groin lymphocele, highlighting the benefit of advanced robotic technology in complex lymphatic surgeries.


Assuntos
Anastomose Cirúrgica , Virilha , Vasos Linfáticos , Linfocele , Microcirurgia , Procedimentos Cirúrgicos Robóticos , Humanos , Linfocele/cirurgia , Masculino , Anastomose Cirúrgica/métodos , Procedimentos Cirúrgicos Robóticos/métodos , Virilha/cirurgia , Vasos Linfáticos/cirurgia , Vasos Linfáticos/diagnóstico por imagem , Microcirurgia/métodos , Linfografia/métodos , Pessoa de Meia-Idade , Veias/cirurgia , Resultado do Tratamento
10.
Cells ; 13(10)2024 May 07.
Artigo em Inglês | MEDLINE | ID: mdl-38786017

RESUMO

Arteries and veins develop different types of occlusive diseases and respond differently to injury. The biological reasons for this discrepancy are not well understood, which is a limiting factor for the development of vein-targeted therapies. This study contrasts human peripheral arteries and veins at the single-cell level, with a focus on cell populations with remodeling potential. Upper arm arteries (brachial) and veins (basilic/cephalic) from 30 organ donors were compared using a combination of bulk and single-cell RNA sequencing, proteomics, flow cytometry, and histology. The cellular atlases of six arteries and veins demonstrated a 7.8× higher proportion of contractile smooth muscle cells (SMCs) in arteries and a trend toward more modulated SMCs. In contrast, veins showed a higher abundance of endothelial cells, pericytes, and macrophages, as well as an increasing trend in fibroblasts. Activated fibroblasts had similar proportions in both types of vessels but with significant differences in gene expression. Modulated SMCs and activated fibroblasts were characterized by the upregulation of MYH10, FN1, COL8A1, and ITGA10. Activated fibroblasts also expressed F2R, POSTN, and COMP and were confirmed by F2R/CD90 flow cytometry. Activated fibroblasts from veins were the top producers of collagens among all fibroblast populations from both types of vessels. Venous fibroblasts were also highly angiogenic, proinflammatory, and hyper-responders to reactive oxygen species. Differences in wall structure further explain the significant contribution of fibroblast populations to remodeling in veins. Fibroblasts are almost exclusively located outside the external elastic lamina in arteries, while widely distributed throughout the venous wall. In line with the above, ECM-targeted proteomics confirmed a higher abundance of fibrillar collagens in veins vs. more basement ECM components in arteries. The distinct cellular compositions and transcriptional programs of reparative populations in arteries and veins may explain differences in acute and chronic wall remodeling between vessels. This information may be relevant for the development of antistenotic therapies.


Assuntos
Artérias , Miócitos de Músculo Liso , Análise de Célula Única , Remodelação Vascular , Veias , Humanos , Artérias/metabolismo , Veias/metabolismo , Miócitos de Músculo Liso/metabolismo , Fibroblastos/metabolismo , Masculino , Feminino , Pessoa de Meia-Idade
12.
Medicina (Kaunas) ; 60(5)2024 May 13.
Artigo em Inglês | MEDLINE | ID: mdl-38792988

RESUMO

Background and Objectives: Facial vascular anatomy plays a pivotal role in both physiological context and in surgical intervention. While data exist on the individual course of the facial artery and vein, to date, the spatial relationship of the vasculature has been ill studied. The aim of this study was to assess the course of facial arteries, veins and branches one relative to another. Materials and Methods: In a total of 90 halved viscerocrania, the facial vessels were injected with colored latex. Dissection was carried out, the relation of the facial vessels was studied, and the distance at the lower margin of the mandible was measured. Furthermore, branches including the labial and angular vessels were assessed. Results: At the base of the mandible, the facial artery was located anterior to the facial vein in all cases at a mean distance of 6.2 mm (range 0-15 mm), with three cases of both vessels adjacent. An angular vein was present in all cases, while an angular artery was only present in 34.4% of cases. Conclusions: The main trunk of the facial artery and vein yields a rather independent course, with the facial artery always located anterior to the vein, while their branches, especially the labial vessels, demonstrate a closer relationship.


Assuntos
Cadáver , Face , Humanos , Face/irrigação sanguínea , Face/anatomia & histologia , Masculino , Feminino , Artérias/anatomia & histologia , Veias/anatomia & histologia , Mandíbula/anatomia & histologia , Mandíbula/irrigação sanguínea
14.
Sci Rep ; 14(1): 12002, 2024 05 25.
Artigo em Inglês | MEDLINE | ID: mdl-38796559

RESUMO

To address several common problems of finger vein recognition, a lightweight finger vein recognition algorithm by means of a small sample has been proposed in this study. First of all, a Gabor filter is applied to deal with the images for the purpose of that these processed images can simulate a kind of situation of finger vein at low temperature, such that the generalization ability of the algorithm model can be improved as well. By cutting down the amount of convolutional layers and fully connected layers in VGG-19, a lightweight network can be given. Meanwhile, the activation function of some convolutional layers is replaced to protect the network weight that can be updated successfully. After then, a multi-attention mechanism is introduced to the modified network architecture to result in improving the ability of extracting important features. Finally, a strategy based on transfer learning has been used to reduce the training time in the model training phase. Honestly, it is obvious that the proposed finger vein recognition algorithm has a good performance in recognition accuracy, robustness and speed. The experimental results show that the recognition accuracy can arrive at about 98.45%, which has had better performance in comparison with some existing algorithms.


Assuntos
Algoritmos , Dedos , Veias , Humanos , Dedos/irrigação sanguínea , Processamento de Imagem Assistida por Computador/métodos , Redes Neurais de Computação , Reconhecimento Automatizado de Padrão/métodos
15.
Sensors (Basel) ; 24(9)2024 Apr 24.
Artigo em Inglês | MEDLINE | ID: mdl-38732790

RESUMO

With the development of biometric identification technology, finger vein identification has received more and more widespread attention for its security, efficiency, and stability. However, because of the performance of the current standard finger vein image acquisition device and the complex internal organization of the finger, the acquired images are often heavily degraded and have lost their texture characteristics. This makes the topology of the finger veins inconspicuous or even difficult to distinguish, greatly affecting the identification accuracy. Therefore, this paper proposes a finger vein image recovery and enhancement algorithm using atmospheric scattering theory. Firstly, to normalize the local over-bright and over-dark regions of finger vein images within a certain threshold, the Gamma transform method is improved in this paper to correct and measure the gray value of a given image. Then, we reconstruct the image based on atmospheric scattering theory and design a pixel mutation filter to segment the venous and non-venous contact zones. Finally, the degraded finger vein images are recovered and enhanced by global image gray value normalization. Experiments on SDUMLA-HMT and ZJ-UVM datasets show that our proposed method effectively achieves the recovery and enhancement of degraded finger vein images. The image restoration and enhancement algorithm proposed in this paper performs well in finger vein recognition using traditional methods, machine learning, and deep learning. The recognition accuracy of the processed image is improved by more than 10% compared to the original image.


Assuntos
Algoritmos , Dedos , Processamento de Imagem Assistida por Computador , Veias , Humanos , Dedos/irrigação sanguínea , Dedos/diagnóstico por imagem , Veias/diagnóstico por imagem , Processamento de Imagem Assistida por Computador/métodos , Identificação Biométrica/métodos , Atmosfera
16.
J Nepal Health Res Counc ; 21(4): 587-592, 2024 Mar 31.
Artigo em Inglês | MEDLINE | ID: mdl-38616587

RESUMO

BACKGROUND: Although rare, deep vein thrombosis is a potentially life-threatening complication of knee arthroscopy. There are scanty literature analysing deep vein thrombosis after arthroscopy in Nepal. This study aimed to identify the prevalence of deep vein thrombosis in patients undergoing knee arthroscopy without chemoprophylaxis postoperatively at 2 weeks and 6 weeks, respectively. The study also aimed to estimate the risk of deep vein thrombosis in these patients by using Caprini Risk Assessment Model. METHODS: This prospective observational study was conducted at AKB center, B and B Hospital, Gwarko, Lalitpur, over a period of 16 months. All patients who underwent arthroscopy knee surgeries fulfilling the inclusion criteria were included in the study. The primary outcome measure was the prevalence of deep vein thrombosis as diagnosed by compression color-coded ultrasonography of the popliteal vein and calf vein at 2 weeks and 6 weeks postoperatively. The secondary outcome measure was the prevalence of deep vein thrombosis in the risk groups according to Caprini Risk Assessment Model. RESULTS: Out of 612 patients who underwent arthroscopic knee surgeries during the study period, 2 patients (0.33%) developed deep vein thrombosis at 6 weeks follow-up as diagnosed with ultrasonography of the popliteal and calf veins. The prevalence rate in high-risk group was 0.33% (1 in 307) and in very high-risk group was 5.88% (1 in 17). CONCLUSIONS: There was a low prevalence of deep vein thrombosis without chemoprophylaxis following knee arthroscopy in our study. There was higher prevalence of deep vein thrombosis in very high-risk group patients, so close monitoring of such patients during follow-up is recommended.


Assuntos
Tromboembolia Venosa , Trombose Venosa , Humanos , Artroscopia/efeitos adversos , Tromboembolia Venosa/epidemiologia , Tromboembolia Venosa/etiologia , Tromboembolia Venosa/prevenção & controle , Nepal/epidemiologia , Veias , Trombose Venosa/epidemiologia , Trombose Venosa/etiologia , Trombose Venosa/prevenção & controle
18.
J Vasc Surg Venous Lymphat Disord ; 12(4): 101897, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38679143

RESUMO

OBJECTIVE: We investigated the feasibility and efficacy of assessing calf perforating veins (PVs) using the ankle pump in a sitting position (AP-sit) method by color Doppler ultrasound. METHODS: We performed a multicenter prospective clinical trial between November 2022 and October 2023. Eligible patients with chronic venous disease and healthy controls were enrolled. The calf PVs were assessed using three different methods: manual compression in a standing position, manual compression in a sitting position, and AP-sit method. The reflux durations and detection rate of incompetent PVs (IPVs) were compared among the three methods. The number and diameter of calf PVs and distribution of IPVs were analyzed. RESULTS: A total of 50 patients with chronic venous disease and 50 healthy controls were included. There were 173 calves analyzed, including 97 healthy calves and 76 calves with chronic venous disease. The number of PVs per calf was higher in the diseased calves (median, 7.0; interquartile range [IQR], 6.0-8.0) than in the healthy calves (median, 5.0; IQR, 3.0-6.0; P < .001). The diameter of IPVs (median, 2.3 mm; IQR, 2.0-3.1 mm) was larger than that of competent PVs (median, 1.4 mm; IQR, 1.2-1.7 mm). Most of the IPVs (78.8%) were located in the medial and posterior middle of the calf. The reflux duration induced by the AP-sit method was greater than that induced by the manual compression methods (P < .001). Although the AP-sit method had a higher detection rate (92.0%) of IPVs than the manual compression methods (71.7% and 74.3% for standing and sitting, respectively; P < .001), especially in the distal lower leg, the manual compression methods found IPVs not found using the AP-sit method. CONCLUSIONS: Diseased calves with chronic venous disease have more PVs than do healthy calves. IPVs are commonly larger than competent PVs, with most IPVs located in the medial and posterior middle of the calf. Most importantly, the AP-sit method provides a convenient and effective approach for assessing the calf PVs, especially those located in the distal calf, as an alternative or complementary method to traditional manual compression, which is valuable in the daily practice of sonographers.


Assuntos
Estudos de Viabilidade , Postura Sentada , Ultrassonografia Doppler em Cores , Insuficiência Venosa , Estudos Prospectivos , Humanos , Feminino , Masculino , Pessoa de Meia-Idade , Insuficiência Venosa/diagnóstico por imagem , Insuficiência Venosa/fisiopatologia , Doença Crônica , Valor Preditivo dos Testes , Adulto , Idoso , Posicionamento do Paciente , Estudos de Casos e Controles , Perna (Membro)/irrigação sanguínea , Perna (Membro)/diagnóstico por imagem , Veias/diagnóstico por imagem , Fluxo Sanguíneo Regional
19.
Exp Eye Res ; 243: 109904, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38642600

RESUMO

Aqueous humor (AQH) is a transparent fluid with characteristics similar to those of the interstitial fluid, which fills the eyeball posterior and anterior chambers and circulates in them from the sites of production to those of drainage. The AQH volume and pressure homeostasis is essential for the trophism of the ocular avascular tissues and their normal structure and function. Different AQH outflow pathways exist, including a main pathway, quite well defined anatomically and referred to as the conventional pathway, and some accessory pathways, more recently described and still not fully morphofunctionally understood, generically referred to as unconventional pathways. The conventional pathway is based on the existence of a series of conduits starting with the trabecular meshwork and Schlemm's Canal and continuing with a system of intrascleral and episcleral venules, which are tributaries to veins of the anterior segment of the eyeball. The unconventional pathways are mainly represented by the uveoscleral pathway, in which AQH flows through clefts, interstitial conduits located in the ciliary body and sclera, and then merges into the aforementioned intrascleral and episcleral venules. A further unconventional pathway, the lymphatic pathway, has been supported by the demonstration of lymphatic microvessels in the limbal sclera and, possibly, in the uvea (ciliary body, choroid) as well as by the ocular glymphatic channels, present in the neural retina and optic nerve. It follows that AQH may be drained from the eyeball through blood vessels (TM-SC pathway, US pathway) or lymphatic vessels (lymphatic pathway), and the different pathways may integrate or compensate for each other, optimizing the AQH drainage. The present review aims to define the state-of-the-art concerning the structural organization and the functional anatomy of all the AQH outflow pathways. Particular attention is paid to examining the regulatory mechanisms active in each of them. The new data on the anatomy and physiology of AQH outflow pathways is the key to understanding the pathophysiology of AQH outflow disorders and could open the way for novel approaches to their treatment.


Assuntos
Humor Aquoso , Sistema Linfático , Humor Aquoso/fisiologia , Humor Aquoso/metabolismo , Humanos , Sistema Linfático/fisiologia , Esclera/irrigação sanguínea , Malha Trabecular/metabolismo , Vasos Linfáticos/fisiologia , Veias/fisiologia , Úvea , Animais , Pressão Intraocular/fisiologia , Linfa/fisiologia , Corpo Ciliar/irrigação sanguínea , Corpo Ciliar/metabolismo
20.
J Exp Biol ; 227(20)2024 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-38644758

RESUMO

In bivalves and gastropods, ventricle contraction causes a negative pressure in the auricles and increases venous return from the afferent oblique vein (AOV): the constant-volume (CV) mechanism. The flow in the AOV should be a pulsative flow synchronized with the ventricular contraction. The flow in the heart and adjacent vessels of Mytilus galloprovincialis were measured by magnetic resonance imaging to confirm this hypothesis. Under a regular heartbeat, pulsative flows in the AOV and branchial vessels (BVs) were almost completely synchronized with the flow in the aorta, while filling of the ventricle was in the opposite phase. Flows in the BVs were directed to the posterior direction, and a pair of BVs in the gill axes (the efferent BVs) were connected to the AOV. Based on the images of the whole pathway of the AOV in an oblique slice, we confirmed that haemolymph flow was evoked from the efferent BVs and flow into the ventricle via the auricle was completed in a single heartbeat. Therefore, the walls of the AOV and BVs could resist negative transmural pressure caused by the ventricular contraction. In conclusion, the auricle, the AOV and the BVs, including the gill filaments, act as a suction pump. The pulsative venous return is driven by the negative pressure of the AOV as in the CV mechanism, and the negative pressure in the efferent BVs could draw haemolymph from the sinus via the gill and the afferent BVs. Therefore, Mytilus can start and stop its heartbeat as necessary.


Assuntos
Mytilus , Animais , Mytilus/fisiologia , Coração/fisiologia , Veias/fisiologia , Brânquias/fisiologia , Imageamento por Ressonância Magnética , Região Branquial/fisiologia , Hemolinfa/fisiologia , Fluxo Pulsátil/fisiologia
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