Tbx18-dependent differentiation of brown adipose tissue-derived stem cells toward cardiac pacemaker cells.

A cell-sourced biological pacemaker is a promising therapeutic approach for sick sinus syndrome (SSS) or severe atrial ventricular block (AVB). Adipose tissue-derived stem cells (ATSCs), which are optimal candidate cells for possible use in regenerative therapy for acute or chronic myocardial injury, have the potential to differentiate into spontaneous beating cardiomyocytes. However, the pacemaker characteristics of the beating cells need to be confirmed, and little is known about the underlying differential mechanism. In this study, we found that brown adipose tissue-derived stem cells (BATSCs) in mice could differentiate into spontaneous beating cells in 15% FBS Dulbecco's modified Eagle's medium (DMEM) without additional treatment. Subsequently, we provide additional evidence, including data regarding ultrastructure, protein expression, electrophysiology, and pharmacology, to support the differentiation of BATSCs into a cardiac pacemaker phenotype during the course of early cultivation. Furthermore, we found that silencing Tbx18, a key transcription factor in the development of pacemaker cells, terminated the differentiation of BATSCs into a pacemaker phenotype, suggesting that Tbx18 is required to direct BATSCs toward a cardiac pacemaker fate. The expression of Tbx3 and shox2, the other two important transcription factors in the development of pacemaker cells, was decreased by silencing Tbx18, which suggests that Tbx18 mediates the differentiation of BATSCs into a pacemaker phenotype via these two downstream transcription factors.

Applied anatomy of small branches of the portal vein in transverse groove of hepatic hilum.

PURPOSE: The objective of this study was to provide the morphological details on small branches of the portal vein in transverse groove of hepatic hilum. METHODS: According to the surgery significance, the small branches of portal vein in transverse groove of hepatic hilum were named as "Short hepatic portal veins (SHPVs)". SHPVs were minutely dissected in 30 adult cadaveric livers. The number, diameter, length, origin points, and entering liver sites of SHPVs were explored and measured. RESULTS: There were 181 SHPVs in 30 liver specimens, including 46% (83/181) from the left portal vein, 31% (56/181) from the bifurcation, and 23% (42/181) from the right portal vein. At the entering liver sites of SHPVs, 22% (40/181) supplied for segment IV, 9% (17/181) for segment V, 4% (7/181) for segment VI, 23% (41/181) for segment VII, and 42% (76/181) for segment I (caudate lobe). There were 6.0 ± 2.4 branches per liver specimen with range 3-12. The mean diameter of SHPVs was 2.25 ± 0.89 mm. The average length of SHPVs was 4.86 ± 2.12 mm. CONCLUSIONS: SHPVs widely existed in each liver specimen. The detailed anatomical study of SHPVs could be useful to avoid damaging the short portal branches during hepatic operations, such as isolated or combined caudate lobectomy.

Interferon regulatory factor-1 together with reactive oxygen species promotes the acceleration of cell cycle progression by up-regulating the cyclin E and CDK2 genes during high glucose-induced proliferation of vascular smooth muscle cells.

BACKGROUND: The high glucose-induced proliferation of vascular smooth muscle cells (VSMCs) plays an important role in the development of diabetic vascular diseases. In a previous study, we confirmed that Interferon regulatory factor-1 (Irf-1) is a positive regulator of the high glucose-induced proliferation of VSMCs. However, the mechanisms remain to be determined. METHODS: The levels of cyclin/CDK expression in two cell models involving Irf-1 knockdown and overexpression were quantified to explore the relationship between Irf-1 and its downstream effectors under normal or high glucose conditions. Subsequently, cells were treated with high glucose/NAC, normal glucose/H2O2, high glucose/U0126 or normal glucose/H2O2/U0126 during an incubation period. Then proliferation, cyclin/CDK expression and cell cycle distribution assays were performed to determine whether ROS/Erk1/2 signaling pathway was involved in the Irf-1-induced regulation of VSMC growth under high glucose conditions. RESULTS: We found that Irf-1 overexpression led to down-regulation of cyclin D1/CDK4 and inhibited cell cycle progression in VSMCs under normal glucose conditions. In high glucose conditions, Irf-1 overexpression led to an up-regulation of cyclin E/CDK2 and an acceleration of cell cycle progression, whereas silencing of Irf-1 suppressed the expression of both proteins and inhibited the cell cycle during the high glucose-induced proliferation of VSMCs. Treatment of VSMCs with antioxidants prevented the Irf-1 overexpression-induced proliferation of VSMCs, the up-regulation of cyclin E/CDK2 and the acceleration of cell cycle progression in high glucose conditions. In contrast, under normal glucose conditions, H2O2 stimulation and Irf-1 overexpression induced cell proliferation, up-regulated cyclin E/CDK2 expression and promoted cell cycle acceleration. In addition, overexpression of Irf-1 promoted the activation of Erk1/2 and when VSMCs overexpressing Irf-1 were treated with U0126, the specific Erk1/2 inhibitor abolished the proliferation of VSMCs, the up-regulation of cyclin E/CDK2 and the acceleration of cell cycle progression under high glucose or normal glucose/H2O2 conditions. CONCLUSIONS: These results demonstrate that the downstream effectors of Irf-1 are cyclin E/CDK2 during the high glucose-induced proliferation of VSMCs, whereas they are cyclin D1/CDK4 in normal glucose conditions. The Irf-1 overexpression-induced proliferation of VSMCs, the up-regulation of cyclin E/CDK2 and the acceleration of cell cycle progression are associated with ROS/Erk1/2 signaling pathway under high glucose conditions.

Endothelin-induced differentiation of Nkx2.5⁺ cardiac progenitor cells into pacemaking cells.

The mechanisms governing the development of cardiac pacemaking and conduction system are not well understood. In order to provide evidence for the derivation of pacemaking cells and the signal that induce and maintain the cells in the developing heart, Nkx2.5(+) cardiac progenitor cells (CPCs) were isolated from embryonic heart tubes of rats. Endothelin-1 was subsequently added to the CPCs to induce differentiation of them towards cardiac pacemaking cells. After the treatment, Nkx2.5(+) CPCs displayed spontaneous beating and spontaneously electrical activity as what we have previously described. Furthermore, RT-PCR and immunofluorescence staining demonstrated that Tbx3 expression was increased and Nkx2.5 expression was decreased in the induced cells 4 days after ET-1 treatment. And the significantly increased expression of Hcn4 and connexin-45 were detected in the induced cells 10 days after the treatment. In addition, Nkx2.5(+) CPCs were transfected with pGCsi-Tbx3 4 days after ET-1 treatment in an attempt to determine the transcription regulatory factor governing the differentiation of the cells into cardiac pacemaking cells. The results showed that silencing of Tbx3 decreased the pacemaking activity and led to down-regulation of pacemaker genes in the induced cells. These results confirmed that Nkx2.5(+) CPCs differentiated into cardiac pacemaking cells after being treated with ET-1 and suggested that an ET-1-Tbx3 molecular pathway govern/mediate this process. In conclusion, our study support the notion that pacemaking cells originate from Nkx2.5(+) CPCs present in embryonic heart tubes and endothelin-1 might be involved in diversification of cardiomyogenic progenitors toward the cells.

Intramuscular innervations of muscle flaps that are commonly used in clinical settings.

PURPOSE: Abductor hallucis, latissimus dorsi, gracilis, rectus abdominis, sartorius and pectoralis minor are muscle flaps that are commonly used in clinic, but their intramuscular innervation has seldom been systematically investigated. METHODS: Five Chinese fresh human cadavers were included in the study and abductor hallucis, latissimus dorsi, gracilis, rectus abdominis, sartorius and pectoralis muscles were dissected. After gross anatomy measurement, the specimens were then stained by Sihler's staining technique. Intramuscular innervation was observed and the number as well as distribution was recorded. RESULTS: Intramuscular nerves were clearly visualized by Sihler's staining technique. Based on the shape and muscle-tendon morphology, Lim et al. in Muscle Nerve 29:523-530, 2004 grouped the muscles into trapezoidal-shaped (type I), spindle-shaped (type II), and combination-shaped (type III). According to Lim's study the abductor hallucis was a type IIb muscle and was divided into two compartments by the distal tendon. Latissimus dorsi was a type I muscle, divided into 3-4 compartments by intramuscular nerve branches. Gracilis was a type IIa muscle and the distal part was divided into two compartments by intramuscular nerve branches. Rectus abdominis was a type III muscle and the four bellies comprised four compartments, each of which could be designated as a subunit. Sartorius was a type II muscle and it could be divided into 2-3 compartments along the long axis. Pectoralis minor was a type I muscle that was divided into two compartments by extramuscular terminal nerves. CONCLUSIONS: The six muscles are divided into several compartments by the tendon or nerve branches, and all of them make good donor tissue for muscle compartment transfer in reconstructive surgery.

Comparative research of the thin transverse sectional anatomy and the multislice spiral CT on Pterygopalatine Fossa.

AIM: To explore a method to obtain sub-millimeter data of the thin transverse section of the pterygopalatine fossa (PPF), and to study the thin transverse sectional anatomy of the adult pterygopalatine fossa and its communicating structure for providing anatomic gist for the imaging diagnosis and minimal invasive operation when PPF diseased. MATERIAL AND METHODS: Two heads of adult cadaver without macroscopic trauma (four sides of PPF) were selected to observe. Images of 0.6 mm-thick multi-planar construction (MPR) were obtained with multislice spiral CT (MSCT) based on the superior orbitomeatal line. Then, the specimens were sliced into 0.1 mm serial section on the transverse plane with the computerized milling machine, the figures were taken with digital camera and the sectional data were stored in the computer. Lastly, the thin transversal section of PPF was investigated and compared with multislice spiral CT images acquired by MPR technique to explore and discuss the anatomy of the thin transverse section of the internal structure of PPF. RESULTS: PPF was divided into four portions: infrapterygopalatine portion, pterygopalatine ganglionic one, suprapterygopalatine one and roof of PPF according to the structural characteristics of the transverse section of PPF. The infrapterygopalatine portion communicated laterally with the infratemporal fossa through the pterygomaxillary fissure and communicated downwards with the oral cavity via palatine greater and lesser canals. The pterygopalatine ganglion was shown clearly in the pterygopalatine ganglionic portion, and its dimensions were 3.91x1.92 mm at the best layer. In the suprapterygopalatine portion, the sphenopalatine foramen and artery were obviously shown on the medial wall, while the palatovaginal canal and artery, the pterygoid canal and artery, and the foramen rotundum and maxillary nerve were shown from the inferiomedial to laterosuperior on the posterior wall. The vomerovaginal canal and artery were located at the slightly superior portion of the medial side of the palatovaginal canal. CONCLUSION: Figures of thin transverse section and multislice spiral CT have highly consistency for the display of PPF. Both of them can correctly identify the micro-structure, the complex relationship of the connectivity and the spatial localization in the narrow space of PPF. It can provide reference gist for the imaging diagnosis and minimal invasive operation.

Isolation, culture and characterization of cardiac progenitor cells derived from human embryonic heart tubes.

A variety of studies have reported on the isolation and expansion of cardiac stem cells from adult hearts. However, there is little information concerning cardiac stem/progenitor cells derived from embryonic hearts/heart tubes. To provide more evidence for embryonic heart-derived stem/progenitor cells, Nkx2.5+ human cardiac progenitorcells (hCPCs) were isolated and cloned from human heart tubes. The cells stained positive for Nkx2.5 and Oct-4, and negative for alpha-smooth muscle actin (alpha-SMA), cytokeratin, factor-VIII, alpha-sarcomeric actin and c-Kit. GATA-4 expression of Nkx2.5+ hCPCs was higher than that of embryonic limb bud mesenchymal cells of the control group (p < 0.05). These cells were passaged continuously for >3 months (23 passages) and proliferated actively in vitro. After being treated with 5-azacytidine, Nkx2.5+ hCPCs underwent cardiomyogenic differentiation. Ultrastructural observation confirmed that the longitudinal section of these cardiomyogenic differentiation cells clearly revealed typical sarcomeres and intercalated discs. alpha-MHC, alpha-sarcomeric actin and GATA-4 levels were increased in Nkx2.5+ hCPCs treated with 5-azacytidine compared to untreated cells. Nkx2.5+ hCPCs exhibited positive staining and had a higher expression for alpha-SMA when cocultured with canine vascular endothelial cells. After Nkx2.5+ hCPCs were treated with endothelin-1, all cells displayed spontaneous electrical activity and spontaneous beating. Connexin-40 and -45 were stained positive in the treated cells. In conclusion, Nkx2.5+ hCPCs derived from heart tubes have been isolated and cloned in vitro. These cells are capable of long-term self-renewal and possess a potential to differentiate into cardiac muscle-like cells, cardiac pacemaking cells and smooth muscle-like cells. They could have a significant impact on cardiac regeneration medicine and developmental biology.

Functional analysis in vivo of engineered valved venous conduit with decellularized matrix and two bone marrow-derived progenitors in sheep.

Tissue engineering has been considered a promising approach for creating grafts to replace autologous venous valves. Here, ovine bone marrow-derived endothelial progenitor cells (EPCs) and multipotent adult progenitor cells (MAPCs) were harvested and then loaded into decellularized venous matrix to create tissue-engineered (TE) valved vein. Subsequently, the ovine femoral veins containing the valve were removed and replaced by TE grafts or acellular matrix only. The morphology and function were analysed for up to 1 year by ultrasonography, angiography, H&E staining and scanning electron microscopy (SEM). The differentiation of seeded cells was traced immunofluorochemically. The results showed that decellularized venous matrix could initially and feebly attract endogenous cells, but failed afterwards and were insufficient to restore valve function. On the contrary, the seeded cells differentiated into endothelial cells (ECs) in vivo and formed a monolayer endothelium, and smooth muscle cells within the scaffold therefore produced TE grafts comparable to the native vein valve. This TE graft remained patent and sufficient after implantation into the venous circuit of the ovine lower extremity for at least 6 months. Unfortunately, cells seeded on the luminal surface and both sides of the leaflets lost their biological functions at 12 months, resulting in thrombosis formation and leading to complete occlusion of the TE grafts and impotent venous valves. These findings suggest that this TE valved venous conduit can function physiologically in vivo in the medium term. Before translating this TE venous valve into clinical practice, the durability should be improved and thrombogenicity should be suppressed. Copyright © 2016 John Wiley & Sons, Ltd.

Biocompatibility evaluation of tissue-engineered valved venous conduit by reseeding autologous bone marrow-derived endothelial progenitor cells and multipotent adult progenitor cells into heterogeneous decellularized venous matrix.

Clinical treatment of chronic deep venous insufficiency remains difficult despite the availability of various therapies. Previous experimental efforts have demonstrated that the tissue-engineered valvedvenous conduit (TEVV) is a promising option to replace the damaged venous valve. The aim of the present study was to evaluate the TEVV by reseeding bone marrow-derived endothelial progenitor cells and multipotent adult progenitor cells into acellular matrix according to International Standard ISO10993, and to clarify their interactions with blood, the local effect after implantation both in vitro and vivo, and immunogenicity. The results showed that the 2-cm long TEVV did not cause haemolysis in vitro and remained patent without thrombosis formation in vivo. However, the luminal surface of TEVV was partially covered by multilayer cells. Compared with the native ovine femoral vein segment, the TEVV beneath the mouse skin produced significant mononuclear cell infiltration, with serum interleukin-6 and tumour necrosis factor-α similar to normal. The TEVV maintained its structural integrity, while the native ovine femoral vein segments fell apart at postoperative week nine. The TEVV implantation did not change serum immunoglobulin G. In addition, the seeds and extracts of the scaffold did not affect the proliferation of mouse lymphocytes. These findings suggest that the histocompatibility, haemocompatibility and immunogenicity of this TEVV are acceptable owing to complete removal of the cellular components of autologous seeds and residues of chemical regents, thus providing an experimental basis for further clinical translation. Copyright © 2014 John Wiley & Sons, Ltd.

[Correlation between blood flow velocity of feeding arteries and microvessel density of hepatocellular carcinoma].

OBJECTIVE: To evaluate the correlation between the mean of time blood flow velocity (TVmean) of feeding artery around hepatocellular carcinoma (HCC) and the microvessel density (MVD) in relation to tumor cell differentiation, and to evaluate the usefulness of TVmean as a noninvasive preoperative marker of biologic characteristic of HCC. METHODS: To measure TVmean of feeding arteries around the HCC in 45 patients before operation and TVmean of minute arteries in hepatic tissue in 45 normal subjects by ultrasonographic examination. Tumor cell differentiation grade was determined by routine histopathological staining. Tumor MVD was measured by immunohistochemical staining with monoclonal antibodies against F VIII RAg of excised HCC. Correlationship between TVmean of feeding arteries and MVD of HCC was studied. RESULTS: A linear correlation between TVmean of feeding arteries around the tumors of HCC and MVD of HCC tissue (r = 0.794, y = 18.2764 + 1.5544x) was obtained. With TVmean > or = 21.3 cm/s, the positive and negative predictive values of poorly differentiated HCC were 97.4% and 87.5%, respectively. With TVmean < 21.3 cm/s, those of well differentiated HCC were 88.5% and 97.3%, respectively. The degree of reliability of calculating HCC cell differentiation according to TVmean was 89.5%. CONCLUSION: Tumor growth and cellular differentiation, the two major factors affecting prognosis of HCC, may be evaluated by TVmean of feeding arteries around the tumor. It offers a useful preoperative information for predicting prognosis of HCC patients.

Bone marrow-derived, neural-like cells have the characteristics of neurons to protect the peripheral nerve in microenvironment.

Effective repair of peripheral nerve defects is difficult because of the slow growth of new axonal growth. We propose that "neural-like cells" may be useful for the protection of peripheral nerve destructions. Such cells should prolong the time for the disintegration of spinal nerves, reduce lesions, and improve recovery. But the mechanism of neural-like cells in the peripheral nerve is still unclear. In this study, bone marrow-derived neural-like cells were used as seed cells. The cells were injected into the distal end of severed rabbit peripheral nerves that were no longer integrated with the central nervous system. Electromyography (EMG), immunohistochemistry, and transmission electron microscopy (TEM) were employed to analyze the development of the cells in the peripheral nerve environment. The CMAP amplitude appeared during the 5th week following surgery, at which time morphological characteristics of myelinated nerve fiber formation were observed. Bone marrow-derived neural-like cells could protect the disintegration and destruction of the injured peripheral nerve.

Cardiomyocyte differentiation induced in cardiac progenitor cells by cardiac fibroblast-conditioned medium.

Our previous study showed that after being treated with 5-azacytidine, Nkx2.5(+) human cardiac progenitor cells (CPCs) derived from embryonic heart tubes could differentiate into cardiomyocytes. Although 5-azacytidine is a classical agent that induces myogenic differentiation in various types of cells, the drug is toxic and unspecific for myogenic differentiation. To investigate the possibility of inducing CPCs to differentiate into cardiomyocytes by a specific and non-toxic method, CPCs of passage 15 and mesenchymal stem cells (MSCs) were treated with cardiac ventricular fibroblast-conditioned medium (CVF-conditioned medium). Following this treatment, the Nkx2.5(+) CPCs underwent cardiomyogenic differentiation. Phase-contrast microscopy showed that the morphology of the treated CPCs gradually changed. Ultrastructural observation confirmed that the cells contained typical sarcomeres. The expression of cardiomyocyte-associated genes, such as alpha-cardiac actin, cardiac troponin T, and beta-myosin heavy chain (MHC), was increased in the CPCs that had undergone cardiomyogenic differentiation compared with untreated cells. In contrast, the MSCs did not exhibit changes in morphology or molecular expression after being treated with CVF-conditioned medium. The results indicated that Nkx2.5(+) CPCs treated with CVF-conditioned medium were capable of differentiating into a cardiac phenotype, whereas treated MSCs did not appear to undergo cardiomyogenic differentiation. Subsequently, following the addition of Dkk1 and the blocking of Wnt signaling pathway, CVF-conditioned medium-induced morphological changes and expression of cardiomyocyte-associated genes of Nkx2.5(+) CPCs were inhibited, which indicates that CVF-conditioned medium-induced cardiomyogenic differentiation of Nkx2.5(+) CPCs is associated with Wnt signaling pathway. In addition, we also found that the activation of Wnt signaling pathway was accompanied by higher expression of GATA-4 and the blocking of the pathway inhibited the expression of GATA-4 in CVF-conditioned medium-incubated Nkx2.5(+) CPCs. This finding suggests that Wnt signaling pathway may alter GATA-4 expression and activate the cardiogenic program in the regulation of differentiation. In conclusion, Nkx2.5(+) CPCs have enormous potential for cardiomyogenic differentiation and the CVF-conditioned medium specifically induces CPCs to differentiate into a cardiac phenotype. Wnt signaling pathway is involved in CVF-conditioned medium-induced cardiomyogenic differentiation of Nkx2.5(+) CPCs.

Knockdown Epithelial Membrane Protein 1 Suppresses Human Degenerative Intervertebral Disc-Derived Nucleus Pulposus Cell Proliferation.

OBJECTIVE: Our previous work showed that epithelial membrane protein 1 (EMP1) is highly expressed in nucleus pulposus of the human degenerative intervertebral disc. The present study was designed to investigate the role of EMP1 in nucleus pulposus cells in intervertebral disc degeneration (IDD). DESIGN: Human nucleus pulposus cells derived from degenerative intervertebral discs were cultured. EMP1 expression was knocked down by lentivirus-mediated specific interfering RNA. Cell morphology was observed, and cell proliferation, apoptosis, and cycle were evaluated. RESULTS: Knockdown of EMP1 inhibited cell proliferation, caused cells to shrink, and accelerated the apoptosis induced by serum deprivation or addition of cycloheximide but did not evoke apoptosis in normal culture conditions. CONCLUSIONS: These findings suggest that EMP1 promoted chondrocyte proliferation, survival, and morphological change of cells during IDD, implying that EMP1 may be a target for biological therapy for IDD.

Epithelial membrane protein 1 inhibits human spinal chondrocyte differentiation.

The molecular mechanisms underlying human spinal chondrocyte differentiation remain unclear. We recently demonstrated that epithelial membrane protein 1 (EMP1) is highly expressed in degenerative intervertebral discs. EMP1 is involved in the differentiation of multiple cell types, including progenitor/pre-B cells, neurons, and podocytes. Therefore, we hypothesize that EMP1 may participate in the differentiation of spinal chondrocytes. We cultured chondrocytes from human nucleus pulposus. Through lentivirus-mediated knockdown and overexpression of EMP1, we find that EMP1 promotes cell proliferation and survival, alters cell morphology and cell cycle, reduces cell condensation, and inhibits cell hypertrophy and the expression of chondrocyte maturation markers such as collagen X, aggrecan, sex-determining region Y (SRY)-box 9, and runt-related transcription factor 2. We also show that EMP1 is not expressed in the ossification center of vertebrae but is highly expressed in the nucleus pulposus and growth plate, where chondrocytes are immature and endochondral ossification has not occurred. These results suggest that EMP1 inhibits human spinal chondrocyte differentiation.

Sectional anatomy of the optic pathways on the coronal plane.

BACKGROUND: The purpose of this study was to provide practical data for the imaging diagnosis of the optic pathways. METHODS: Sectional anatomy of the optic pathways on the coronal plane was investigated on 15 sets of serial coronal sections of the head of Chinese adult cadavers and 6 sets of serial coronal magnetic resonance imaging of normal adults. RESULTS: On the coronal plane, we recognized the special structures of optic pathways by 5 key sections. (1) The midorbital optic nerve lay superomedially in the center of the adipose body of the orbit, surrounded by the subarachnoid space and the sheath of the optic nerve. (2) The optic chiasma was transverse between the optic and infundibular recesses of the portion of the floor of the third ventricle and it lay below the A1 segment of the anterior cerebral artery and above the tuber cinereum and the pituitary stalk, C2 or C3 segment of the internal carotid artery laterally. (3) The optic tract lay between the crus cerebri and the amygdaloid, the tail of the caudate nucleus laterally. The anterior choroidal artery inferiorly and downward M2 segment of the middle cerebral artery lay between the uncus and the crus cerebri. (4) The lateral geniculate body lay between the crus cerebri medially and the tail of the caudate nucleus laterally, the uncus and P2 segment of the posterior cerebral artery inferiorly. (5) The optic radiation formed the lateral wall of the lateral ventricle both in the temporal horn and in the occipital horn. The optic radiation was separated from the wall of the occipital horn by the tapetum, a thin layer of fibers derived from the splenium of the corpus callosum. Coronal sectional anatomy and magnetic resonance imaging of the optic pathways revealed similar results. CONCLUSION: This study provides a good understanding of the structures of the optic pathways by correlation of coronal sections of the head of adult cadavers with the coronal magnetic resonance images of normal adults.

Observation and measurements of long thoracic nerve: a cadaver study and clinical consideration.

Long thoracic nerve (LTN) is an important nerve originating from cervical nerve roots. It varies a lot in origins and branches, which lead to several clinical problems, such as diagnosis, prophylaxis and treatment of LTN injury. LTN was dissected in 38 cadavers in the present study. Origin, level of union, branches, sites where nerve entered the muscle, length of nerve trunk and branches as well as transverse diameter were documented. Different derivations of LTN were observed, and C4-7, C5-7, C5 and C7, C5-7, C5-8, C6 and C7, and branch from C6 was the most important components of LTN. After evolution, LTN trunk was composed by superior and inferior trunks at scalenus muscle or the three superior slips level. Branches of LTN traveled on the surface of the six superior slips of anterior serratus muscle and then penetrated through the inferior slips without correlation between different branches. Mean length of trunk of LTN is 111.73 (30.08) mm, axis of cross section was 2.27x0.96 mm at the union level and 1.91 x 0.68 mm at the end branch. Each slip was innervated by 1-4 branches of LTN. The observation and measurement data described in our study presented some variations and could provide clinicians with important information on diagnosis, prophylaxis and treatment of LTN injury and pursuing more suitable muscle flaps for reconstruction operation.

Applied Anatomy of the Femoral Veins in Macaca fascicularis / Anatomía Aplicada de las Venas Femorales en Macaca fascicularis

The aim was to understand the anatomical features of the venous valve in Macaca fascicularis and to compare it with that of humans. The bilateral lower limbs (24 limbs from 12 animals) of Macaca fascicularis cadavers were dissected, and the femoral veins (FVs) were equally divided into distal, intermediate, and proximal sections. The external diameter of the FV in each section was measured. The venous valves were observed microscopically and stained with hematoxylin and eosin as well as trichrome. Data describing the human venous valve were collected from the current literature. No great saphenous veins were found among the 24 lower limbs from the Macaca fascicularis cadavers. The external diameters of the FVs in the distal, intermediate, and proximal sections were 3.53 ± 0.37 mm, 3.42 ± 0.55 mm, and 3.37 ± 0.54 mm, respectively. In most cases, there was one venous bivalve located in the FV approximately 0-2.71 mm below the junction of the FV and the deep femoral vein. Endothelium covered the luminal and sinusal surfaces of the leaflets. Abundant collagen fibers were found under the endothelial cells beneath the luminal surface of the leaflets. An elastin fiber network was located under the sinus endothelial surface. Smooth muscle cells in the FV extend to the edge of the valve. The venous valve of Macaca fascicularis is similar to that of humans, both morphologically and histologically. However, there is only one venous bivalve and no great saphenous vein in Macaca fascicularis.

El objetivo fue comprender las características anatómicas de la válvula venosa en Macaca fascicularis y compararla con la de los humanos. Fueron disecados bilateralmente los miembros pélvicos (24 miembros de 12 animales) de cadáveres de Macaca fascicularis; las venas femorales (VF) fueron divididas en secciones distal, media y proximal. Se midió el diámetro externo de las VFs en cada sección. Las válvulas venosas se observaron microscópicamente y se tiñeron con H-E y tricrómico. Los datos para describir la válvula venosa humana se obtuvieron desde la literatura. No se encontraron venas safenas magnas entre los 24 miembros inferiores. Los diámetros externos de las VFs en las secciones distal, media y proximal fueron 3,53±0,37 mm, 3,42 mm±0,55, y 3,37±0,54 mm, respectivamente. En la mayoría de los casos, hubo vena bivalva situada aproximadamente 0-2,71 mm debajo de la unión de la VF y la vena femoral profunda. El endotelio cubrió las superficies luminal y sinusal. Se observaron abundantes fibras de colágeno en las células endoteliales bajo la superficie luminal de las válvulas. Una red de fibras de elastina se encontró bajo la superficie del seno endotelial. Las células musculares lisas en las VFs se extiendían hasta el margen de la válvula. La válvula venosa del Macaca fascicularis es similar a la de los seres humanos, morfológica e histológicamente. Sin embargo, sólo hubo una vena bivalvular, y no se observaron venas safenas en Macaca fascicularis.