Large intradiploic arachnoid cyst of the skull in child-a case report and new terminology proposition.

We present a rare finding of the arachnoid matter invaginating into the base of middle cranial fossa and creating an abnormal space. Presented entity was incidentally found in head CT scan of 12-year-old male. Based on the radiological characteristics in CT scans and MR images, the diagnosis of intradiploic arachnoid cyst (AC) was suggested. After surgical intervention and histopathological analysis of the specimen, the diagnosis was confirmed. We assume this is the first description of large intrasphenoid AC without any traumatic or iatrogenic cause. The literature provides many different terms for the phenomenon. We are proposing the term intradiploic arachnoid diverticulum as the more accurate for capturing the essence of the phenomenon. It provides clear differentiation of the entities from classical arachnoid cysts since they are of different anatomical localization (intradural vs. extradural) and etiopathogenesis. Management with arachnoid diverticulum is not yet established, but observation with serial imaging studies should be recommended as primary management in case of asymptomatic cyst. When cyst is symptomatic, surgical treatment may be required.

Anatomy of the pontine arteries and perforators of the basilar artery in humans.

Cerebral blood flow constitutes a critical area of interest for neurologists, neurosurgeons, and interventional radiologists as a social burden related to ischemic stroke, hemorrhagic stroke, and vascular dementia is expected to intensify. There is a great need to develop new and effective therapies, therefore deepening understanding of cerebrovascular anatomy, physiology, and pathology is crucial. The main aim of the study was to develop a comprehensive classification of the pontine arteries considering their typology, relations to the cranial nerves, branching schemes, and superficial pontine blood supply areas. We prepared 100 anatomical specimens of the human brainstem with the basilar artery, the pontine arteries, and the terminal perforating arteries. With the use of microsurgical microscope, we analyzed morphometry of the basilar artery, origins, courses, and branching patterns of the pontine arteries as well as distribution of the terminal perforators in relation to pontine superficial vascular areas and the cranial nerves. Additionally, we studied presence of pontine branches of the superior cerebellar artery (SCA) and anterior inferior cerebellar artery (AICA). Repetitive branching patterns, origins, and courses led us to distinguish five types of the pontine arteries: type 1-the paramedian branches, type 2-the short circumflex branches, type 3-composition of the paramedian and the short circumflex branches, type 4-long circumflex branches, and type 5-median branches penetrating the pons along the basilar sulcus. Types 1, 2, and 4 were described in the literature previously, but the classification did not include the median branches (the most prevalent branches) and frequently occurring combinations of the types 1 and 2. There were seven pontine arteries on both sides on average that presented the following general pattern: the first pontine artery below the SCA is a type 4 vessel called the posterolateral pontine artery and it is followed by a type 2 vessel-the superolateral pontine artery; the next three arteries represent the types 1, 2, and 3 and supply most of the ventral pontine surface; the sixth artery-the anterolateral pontine artery-is a short circumflex branch and the seventh artery, originating below the AICA, represents long circumflex arteries. Occlusion of each of the abovementioned vessels relates to a specific pontine vascular syndrome. As explained by the phylogenesis and ontogenesis of the central nervous system, the pontine arteries are subject to variability. The SCA and the AICA took part in the pontine blood supply in 2.5% and 12.5% of cases, respectively, therefore neurovascular interventions involving the SCA, or the AICA may lead to pontine ischemia. Contact of the pontine arteries with the cranial nerves depends on the vessel type and origin location.

Mechanism of Spontaneous Intracerebral Hemorrhage Formation: An Anatomical Specimens-Based Study.

BACKGROUND: Despite advances in understanding various risk and prognostic factors, spontaneous intracerebral hemorrhage is connected to very high morbidity and mortality, while the therapy is mainly supportive. Understanding of the pathophysiology of initial hematoma expansion is limited due to insufficient clinical data and lack of a suitable animal model. METHODS: We injected 40 anatomic specimens of the basal ganglia with contrast medium, scanned them with a micro-computed tomography scanner and analyzed the results of radiological studies, direct and histological examinations. RESULTS: In 9 cases, micro-computed tomography and histological examinations revealed contrast medium extravasations mimicking intracerebral hematomas. The artificial hematomas spread both proximally and distally along the ruptured perforator and its branches in the perivascular spaces and detached the branches from the adjacent neural tissue leading to destruction of the tissue and secondary extravasations. Moreover, some contrast extravasations skipped to the perivascular spaces of unruptured perforators, created further extravasation sites and aggravated the expansion of the artificial hematoma. There was no subarachnoid extension of any artificial hematoma. CONCLUSIONS: We postulate that a forming basal ganglia intracerebral hematoma spreads initially in the perivascular space, detaches the branches from the neural tissue and causes secondary bleeding. It can also skip to the perivascular space of a nearby perforator. The proposed mechanism of hematoma initiation and formation explains extent of damage to the neural tissue, variability of growth in time and space, creation of secondary bleeding sites, and limited usefulness of surgical interventions. The model is reproducible, the extent of the artificial hematoma can be easily controlled, the rupture sites of the perforating arteries can be determined, and preparation of the model does not require specialized, expensive equipment apart from the micro-computed tomography scanner.

Anatomical variants of the medioplantar oblique ligament and inferoplantar longitudinal ligament: an MRI study.

PURPOSE: The spring ligament complex (SL) is the chief static stabilizer of the medial longitudinal foot arch. The occurrence of normal anatomical variants may influence radiological diagnostics and surgical treatment. The aim of this study was to evaluate anatomical variants of the part of SL located inferior to the talar head (i-SL), medioplantar oblique ligament (MPO) and inferoplantar longitudinal ligament (IPL). METHODS: We included 220 MRI examinations of the ankle performed on a 3.0 T engine. Only patients with a normal SL were included. Two musculoskeletal radiologists assessed the examinations and Cohen's kappa was used to assess agreement. Differences between groups were assessed using the chi-squared test; p < 0.05 was considered as significant. The final decision was made by consensus. RESULTS: Most commonly, i-SL was composed of the two ligaments IPL and MPO n = 167 (75.9%); in this group, bifid ligaments occurred in 19.2%, most commonly in the MPO. A branch to the os cuboideum was seen in n = 17 (10.2%). Three ligaments were seen in n = 52 (23.6%). In this group, bifid ligaments occurred in 13.5%; most commonly, the IPL was bifid and a branch to the os cuboideum was noted in n = 6 (11.5%). In one case, n = 1 (0.04%), we identified MPO, IPL and two accessory ligaments. No significant relationship was noted between the number of ligaments, the presence of bifid ligaments and side or gender (p > 0.05). CONCLUSION: More than two aligaments were seen in 24.1% of examined cases, the most common variant was the presence of MPO, IPL and one accessory ligament.

A Comprehensive miRNome Analysis of Macrophages Isolated from db/db Mice and Selected miRNAs Involved in Metabolic Syndrome-Associated Cardiac Remodeling.

Cardiac macrophages are known from various activities, therefore we presume that microRNAs (miRNAs) produced or released by macrophages in cardiac tissue have impact on myocardial remodeling in individuals with metabolic syndrome (MetS). We aim to assess the cardiac macrophage miRNA profile by selecting those miRNA molecules that potentially exhibit regulatory functions in MetS-related cardiac remodeling. Cardiac tissue macrophages from control and db/db mice (an animal model of MetS) were counted and sorted with flow cytometry, which yielded two populations: CD45+CD11b+CD64+Ly6Chi and CD45+CD11b+CD64+Ly6Clow. Total RNA was then isolated, and miRNA expression profiles were evaluated with Next Generation Sequencing. We successfully sequenced 1400 miRNAs in both macrophage populations: CD45+CD11b+CD64+Ly6Chi and CD45+CD11b+CD64+Ly6Clow. Among the 1400 miRNAs, about 150 showed different expression levels in control and db/db mice and between these two subpopulations. At least 15 miRNAs are possibly associated with MetS pathology in cardiac tissue due to direct or indirect regulation of the expression of miRNAs for proteins involved in angiogenesis, fibrosis, or inflammation. In this paper, for the first time we describe the miRNA transcription profile in two distinct macrophage populations in MetS-affected cardiac tissue. Although the results are preliminary, the presented data provide a foundation for further studies on intercellular cross-talk/molecular mechanism(s) involved in the regulation of MetS-related cardiac remodeling.

The Kager's fat pad radiological anatomy revised.

PURPOSE: The aim of the study was to map connections within the Kager's fat pad between the structures which limit it. METHODS: A retrospective re-review of 200 ankle magnetic resonance imaging (MRI) examination was conducted. Connections within the Kager's fat pad between the superior peroneal retinaculum, the fibulotalocalcaneal ligament, the posterior talocalcaneal ligament, the flexor hallucis longus, the paratenon of the Achilles tendon, the flexor retinaculum and bones were studied and a model of the connections was constructed. RESULTS: The superior peroneal retinaculum was directly connected with the fibulotalocalcaneal ligament in 85.5% of cases, the lateral part of the paratenon in 82.5%, the processus posterior tali in 78.5%, the posterior talofibular ligament in 32%, the flexor retinaculum in 29.5% and the anterior talofibular ligament in 9%. The fibulotalocalcaneal ligament was connected with the paratenon (on the medial side 88.5%, on the lateral side 68.5%), the flexor retinaculum in 70%, the posterior process of the talus in 79%, the osteofibrosus tunnel for the flexor hallucis longus in 53%, the posterior talofibular ligament in 43.5% and the calcaneofibular ligament in 10.5%. The posterior talocalcaneal ligament was connected with the fibulotalocalcaneal ligament in 71%, with the osteofibrosus tunnel for the flexor hallucis longus in 76.5%, with the flexor retinaculum in 70%. The plantaris tendon showed projection to the crural fascia in 34 of % cases. CONCLUSION: In the Kager's fat pad there are present more connections than previously reported. All the connections unit at the level of the posterior process of the talus.

The twisted structure of the fetal calcaneal tendon is already visible in the second trimester.

INTRODUCTION: The progress in morphological science results from the greater possibilities of intra-pubic diagnosis and treatment of congenital disabilities, including the motor system. However, the structure and macroscopic development of the calcaneal tendon have not been investigated in detail. Studies on the adult calcaneal tendon showed that the calcaneal tendon is composed of twisted subtendons. This study aimed to investigate the internal structure of the fetal calcaneal tendon in the second trimester. MATERIALS AND METHODS: Thirty-six fetuses fixed in 10% formaldehyde were dissected using the layer-by-layer method and a surgical microscope. RESULTS: The twisted structure of the calcaneal tendon was revealed in all specimens. The posterior layer of the calcaneal tendon is formed by the subtendon from the medial head of the gastrocnemius muscle. In contrast, the anterior layer is formed by the subtendon from the lateral head of the gastrocnemius muscle. The subtendon from the soleus muscle constitutes the anteromedial outline of the calcaneal tendon. The lateral outline of the calcaneal tendon is formed by the subtendon originating from the medial head of the gastrocnemius muscle. In contrast, the medial outline is formed by the subtendon from the soleus muscle. In most of the examined limbs, the plantaris tendon attached to the tuber calcanei was not directly connected to the calcaneal tendon. CONCLUSIONS: The twisted structure of the subtendons of the fetal calcaneal tendon is already visible in the second trimester and is similar to that seen in adults.

Anatomy of proximal attachment, course, and innervation of hamstring muscles: a pictorial essay.

Hamstring injuries are very common in sports medicine. Knowing their anatomy, morphology, innervation, and function is important to provide a proper diagnosis, treatment as well as appropriate prevention strategies. In this pictorial essay, based on anatomical dissection, the detailed anatomy of muscle-tendon complex is reviewed, including their proximal attachment, muscle course, and innervation. To illustrate hamstrings' role in the rotational control of the tibia, the essay also includes the analysis of their biomechanical function.Level of evidence V (expert opinion based on laboratory study).

Morphology and morphometry of pulmonary veins and the left atrium in multi-slice computed tomography.

PURPOSE: Pulmonary veins are involved in pathogenesis and treatment of atrial fibrillation and structures at risk during thoracic surgeries. There is lack of data regarding pulmonary vein morphology and morphometry in normal population. METHODS: The study was conducted using 135 chest computed tomography studies with intra-venous iodine contrast injection. The study population contained 86 females and 49 males, mean age was 60. 13 had atrial fibrillation.The studies were analyzed using radiological workstation. RESULTS: Mean dimensions of the left atrium: transverse 52 mm, coronal 49 mm, and sagittal 35 mm. The mean volume of the left atrium was 93 cm3. The mean volume of the left atrium in patients with atrial fibrillation was 176 cm3. The sagittal dimension and the volume of the left atrium were correlated with age, r = 0.43 and r = 0.42, respectively. Surface area of the left inferior pulmonary vein ostium was 136 mm2, significantly less than the surface area of other ostia of pulmonary veins. The mean distance between two pulmonary veins was 5.42 mm on the right and 4.02 mm on the left side. 13 types of pulmonary veins outflow patterns were described on the right side and 5 types on the left side. 66.7% of right pulmonary veins and 82% of the left pulmonary veins emptied into the left atrium with two venous trunks on each side (the typical pattern). CONCLUSIONS: Morphological features of pulmonary veins and morphometry of the left atrium and pulmonary veins are important for clinical purposes and are in accordance with previous papers.

The radioanatomical assessment of the Körner's septum.

PURPOSE OF THE STUDY: Körner's septum (KS) is a developmental remnant formed at the junction of mastoid and temporal squama, representing the persistence of the petrosquamosal suture. During mastoid surgery, it could be taken as a false medial wall of the antrum so that the deeper cells might not be explored. The aim of the study was to assess a Körner's septum prevalence and to analyze its topography. METHODS: The study was performed on 80 sets of cone-beam computed tomography (CBCT) images of temporal bone (41 male, 39 female, 160 temporal bones). Körner's septum was identified and its thickness was measured on axial sections at three points: at the level of superior semicircular canal (SCC), at the level of head of malleus (HM) and at the level of tympanic sinus (TS). RESULTS: KS was encountered at least in one point of measurements in 50 out of 80 sets of CBCT images (62.5%). The average thickness at the level of SCC was 0.87 ± 0.34 mm, at the level of HM was 0.99 ± 0.37 mm and at the level of TS was 0.52 ± 0.17 mm. CONCLUSIONS: Körner's septum is a common structure in the temporal bone-air cell complex. It is more often encountered in men. In half of the patients, it occurs bilaterally. However, in most of the cases it is incomplete with anterior and superior portions being the most constant.

Cells with hematopoietic potential reside within mouse proepicardium.

During embryonic development, hematopoietic cells are present in areas of blood-vessel differentiation. These hematopoietic cells emerge from a specific subpopulation of endothelial cells called the hemogenic endothelium. We have previously found that mouse proepicardium contained its own population of endothelial cells forming a network of vascular tubules. We hypothesize that this EC population contains cells of hematopoietic potential. Therefore, we investigated an in vitro hematopoietic potential of proepicardial cell populations. The CD31+/CD45-/CD71- cell population cultured for 10 days in MethocultTM gave numerous colonies of CFU-GEMM, CFU-GM, and CFU-E type. These colonies consisted of various cell types. Flk-1+/CD31-/CD45-/CD71-, and CD45+ and/or CD71+ cell populations produced CFU-GEMM and CFU-GM, or CFU-GM and CFU-E colonies, respectively. Immunohistochemical evaluations of smears prepared from colonies revealed the presence of cells of different hematopoietic lineages. These cells were characterized by labeling with various combinations of antibodies directed against CD31, CD41, CD71, c-kit, Mpl, Fli1, Gata-2, and Zeb1 markers. Furthermore, we found that proepicardium-specific marker WT1 co-localized with Runx1 and Zeb1 and that single endothelial cells bearing CD31 molecule expressed Runx1 in the proepicardial area of embryonic tissue sections. We have shown that cells of endothelial and/or hematopoietic phenotypes isolated from mouse proepicardium possess hematopoietic potential in vitro and in situ. These results are supported by RT-PCR analyses of proepicardial extract, which revealed the expression of mRNA for crucial regulatory factors for hemogenic endothelium specification, i.e., Runx1, Notch1, Gata2, and Sox17. Our data are in line with previous observation on hemangioblast derivation from the quail PE.

Posterior cruciate ligament is twisted and flat structure: new prospective on anatomical morphology.

PURPOSE: This cadaveric study aimed to elucidate PCL morphology by observing the anatomical relationship with other structures and the fibre layers of the PCL in cross section for remnant preserving PCL reconstruction. METHODS: Seventeen fresh-frozen cadaveric knees were studied, using the clock-face method to analyse the anatomical relationship between the PCL and Humphrey's ligament. The width and thickness of the PCL, Humphrey's and Wrisberg's ligaments were measured. The PCL was cut sharply perpendicular to the tibia shaft, and the fibre layers were observed in cross section. RESULTS: The PCL was located between 12 and 4 o'clock in the right knee (8 and 12 o'clock in the left), while Humphrey's ligament was located between 2 and 4 o'clock in the right knee (8 and 10 o'clock in the left). Humphrey's ligament at femoral insertion, midsubstance and lateral meniscus insertion averaged 8.7 ± 2.3, 5.9 ± 2.1 and 6.1 ± 2.0 mm, respectively, while the thickness at each level averaged 2.0 ± 1.2, 1.6 ± 0.6 and 1.9 ± 0.6 mm. The width of the PCL at midsubstance and at medial meniscus level averaged 13.3 ± 2.0 and 11.0 ± 1.6 mm, respectively, while the thickness of the PCL averaged 5.4 ± 0.8 and 5.5 ± 1.4 mm. In cross section, multiple, interconnected layers were observed which could not be divided. The main layers at each level were aligned from the posterolateral to the anteromedial aspect and formed a C-shape at the medial meniscus level. CONCLUSION: The PCL at midsubstance is flat. PCL appears as a twisted ribbon composed of many small fibres without clearly separate bundles. When remnant preserving PCL reconstruction is performed, it is necessary to take account of not only PCL morphology but also the ligaments of Humphrey and Wrisberg. These findings may affect the PCL footprint and the graft shape in the future remnant preserving PCL reconstruction.

Postnatal development of the subarcuate fossa and subarcuate canaliculus-a computed tomographic study.

PURPOSE: The subarcuate fossa (SF) is an anatomical structure situated on posterior wall of the petrous part of the temporal bone. In older children and adults, SF is a shallow depression and the subarcuate canaliculus starts within it. Awareness of postnatal changing morphology of this region is important especially for otosurgeon. The aim of this paper is to characterize both SF and SC by means of anatomical and radiological methods. METHODS: The study was carried out on CT scans of 101 children, aged 1-60 months. Length of the pyramid (PL), the distance between the anterior semicircular canal (ASC) and the pyramidal apex (PLM), the outer diameter of ASC (ASCD), width under ASC (SFWM), the distance between the fundus of SF and ASC (SFLL), the maximal width of SF lateral to ASC (SFWL), the distance between the fundus of SF and posterior surface of the pyramid (SFL) were measured. RESULTS: Average value of all measured distances: PL 52.14 ± 6.32 mm and PLM 25.73 ± 3.47 mm (raised with age); ASCD 8.63 ± 0.67 mm; SFWM 0.95 ± 1.24 mm; SFLL 1.07 ± 1.63 mm; SFWL 0.76 ± 1.19 mm; SFL 3.60 ± 2.50 mm. CONCLUSIONS: Petrous part of the temporal bone grows with age up to 5 years old, whereas ASC does not. SF diminishes with age: lateral to ASC is well developed in newborns and infants (up to first year), rapidly diminishes in children aged 1-2 years and is totally absent in children > 2 years. SF medial to ASC is constant and diminishes with age. In children older than 3 years morphology of SF is similar to adult.

Traumatic intracranial displacement of the ventriculoperitoneal valve chamber in a child-a report of 2 cases.

We present two cases of traumatic intracranial migration of the ventriculoperitoneal (VPS) valve chamber without malfunction of the system. In both patients, a shunt reservoir was surgically repositioned without a burr hole expansion and with no implantation of a new VPS system. We discuss a role of a head trauma and repeated valve palpation in this rare complication.

Clinical Characteristics of Benign Pediatric Cranial Vault Tumors: Surgical Considerations Based on 100 Cases.

BACKGROUND/AIMS: Tumors of the cranial vault occur at every age of childhood. Although they are mostly benign lesions, their symptomatology is variable and requires extended diagnostics. The choice of therapeutic strategy strongly depends on histopathological diagnosis, and therefore surgical excision is the elective treatment in such cases. Despite several published papers, the literature still lacks reliable clinical characteristics regarding this heterogeneous group of lesions in pediatric patients. METHODS: We present a series of 100 children (55 male, 45 female) with scalp and cranial vault masses (average age: 3.6 years; range: 1 month to 17 years). Eighty-three (83%) patients underwent surgical excision. Demographic data, clinical presentation, diagnostic studies, choice of therapy, and the results of treatment were evaluated. RESULTS: All removed tumors were benign pathologies: pilar cysts (30%), epidermoid/dermoid cysts (21%), vascular malformations (11%), inflammatory tumors (5%), and dysraphic remnants (2%). However, underlying bone destruction was observed in 61% of cases. Cranial extension occurred in 34%. Recurrence was noted in 1 case. CONCLUSIONS: Cranial vault tumors are characterized by constant growth and may penetrate the cranial cavity. Delayed surgery increases the risk of intracranial complications. Surgical problems include inappropriate planning, higher risk of intraoperative bleeding, and the need for subsequent cranioplasty.

Age dependence of critical pressure in the segments and branches of the circle of Willis.

Spontaneous intracranial haemorrhage is one of the most dramatic neurological disasters. The source of haemorrhage is linked to the pathology of the arterial wall or is unknown. Because the risk of haemorrhagic stroke increases with age, we tried to investigate the relationship between age and rupture pressure of cerebral arteries. In the presented study, 51 segments of large cerebral arteries (at the level of the circle of Willis and its incoming and outgoing branches) were obtained from 33 cadaver brains aged 12-86 years. The segments were pressurized up to the rupture. The rupture pressure was noted. The highest observed pressure was 4.3atm in specimen aged 24 years. The lowest pressure 1.19atm was observed in specimen aged 80 years. The mean value of rupture pressure of all investigated segments was 2.28atm. Statistical analysis showed a nonlinear exponential decrease of the rupture pressure of the large cerebral arteries with age. The main conclusion from our study is that drop of cerebral arteries strength is observed to the age of 40. Later this lowering is visible but not so evident.

Mouse Proepicardium Exhibits a Sprouting Response to Exogenous Proangiogenic Growth Factors in vitro.

Angiogenesis contributes to the generation of the vascular bed but also affects the progression of many diseases, such as tumor growth. Many details of the molecular pathways controlling angiogenesis are still undefined due to the lack of appropriate models. We propose the proepicardial explant as a suitable model for studying certain aspects of angiogenesis. The proepicardium (PE) is a transient embryonic structure that contains a population of undifferentiated endothelial cells (ECs) forming a vascular net continuous with the sinus venosus. In this paper, we show that PE explants give rise to CD31-positive vascular sprouts in the presence of basic fibroblast growth factor (bFGF) and 2 isoforms of vascular endothelial growth factor A (VEGF-A), i.e. VEGF-A120 and VEGF-A164. Vascular sprouts exhibit differences in number, length, thickness and the number of branches, depending on the combination of growth factors used. Moreover, the ECs of the sprouts express various levels of mRNA for Notch1 and its ligand Dll4. Additionally, stimulation with bFGF/VEGF-A164 upregulates the expression of Lyve-1 antigen in the ECs in the sprouts. In summary, we present a new model for angiogenesis studies involving mouse PE as a source of ECs. We believe that our model may act as a supplementary assay for angiogenesis studies along with the existing models.

Usefulness of the radiological planning for hearing preservation surgery in vestibular schwannoma.

PURPOSE: During vestibular schwannoma surgery there is a risk of endolymphatic duct and sac injury, which may cause a loss or a deterioration of hearing. The goal of the study was to evaluate the empirical utility of presurgical planning using CT with the bone window for the hearing preservation surgery. METHODS: The study was performed on 14 human temporal bones. CT scans with the bone window were obtained in the standard position. Safe drilling line was evaluated and after that drilling distances were analysed: the lateral drilling distance, total length of internal acoustic meatus, drilled length of internal acoustic meatus. After this, a surgical exposure was performed, using size of a drill tip as measuring scale. The dura was excised and endolymphatic duct was injected with a latex. Revision of the internal acoustic meatus was performed with the use of a microscope. RESULTS: Mean results of safe drilling coefficients were: lateral drilling distance: 10 ± 2 mm, total length of internal acoustic meatus: 9 ± 2 mm, drilled length of internal acoustic meatus: 7 ± 2 mm. In all cases, no endolymphatic duct injury was observed. CONCLUSIONS: Preoperative radiological planning using the safe drilling coefficients is of value for the hearing preservation surgery in vestibular schwannoma. The size of the drilling tip may be used as an intraoperative measuring scale during this procedure. However, CT with a bone window is a necessary tool for the purposes of this procedure.

3-D reconstruction and multiple marker analysis of mouse proepicardial endothelial cell population.

BACKGROUND: The proepicardium (PE), a transient embryonic structure crucial for the development of the epicardium and heart, contains its own population of endothelial cells (ECs). The aim of our study was to determine the pattern, anatomical orientation and phenotypic marker expression of the endothelial cell network within the PE. RESULTS: Immunohistochemical findings revealed that proepicardial ECs express both early and late EC-specific markers such as CD31, Flk-1, Lyve-1 and Tie-2 but not SCL/Tal1, vWF, Dll4 or Notch1. Proepicardial ECs are present in the vicinity of the sinus venosus (SV) and form a continuous network of vascular sprouts/tubules connected with the SV endothelium, with Ter-119-positive erythroblasts in the vascular lumina. CONCLUSIONS: On the basis of our results, we postulate the existence of a continuous network of ECs in the PE, exhibiting connection and/or patency with the SV and forming vessels/tubules/strands. Marker expression suggests that ECs are immature and undifferentiated, which was also confirmed with a transmission electron microscopy (TEM) analysis. Our results deliver new data for a better understanding of the nature of proepicardial ECs.

Medial meniscus anatomy-from basic science to treatment.

This paper focuses on the anatomical attachment of the medial meniscus. Detailed anatomical dissections have been performed and illustrated. Five zones can be distinguished in regard to the meniscus attachments anatomy: zone 1 (of the anterior root), zone 2 (anteromedial zone), zone 3 (the medial zone), zone 4 (the posterior zone) and the zone 5 (of the posterior root). The understanding of the meniscal anatomy is especially crucial for meniscus repair but also for correct fixation of the anterior and posterior horn of the medial meniscus.