Identification of quiescent FOXC2+ spermatogonial stem cells in adult mammals

In adult mammals, spermatogenesis embodies the complex developmental process from spermatogonial stem cells (SSCs) to spermatozoa. At the top of this developmental hierarchy lie a series of SSC subpopulations. Their individual identities as well as the relationships with each other, however, remain largely elusive. Using single-cell analysis and lineage tracing, we discovered both in mice and humans the quiescent adult SSC subpopulation marked specifically by forkhead box protein C2 (FOXC2). All spermatogenic progenies can be derived from FOXC2+ SSCs and the ablation of FOXC2+ SSCs led to the depletion of the undifferentiated spermatogonia pool. During germline regeneration, FOXC2+ SSCs were activated and able to completely restore the process. Germ cell-specific Foxc2 knockout resulted in an accelerated exhaustion of SSCs and eventually led to male infertility. Furthermore, FOXC2 prompts the expressions of negative regulators of cell cycle thereby ensures the SSCs reside in quiescence. Thus, this work proposes that the quiescent FOXC2+ SSCs are essential for maintaining the homeostasis and regeneration of spermatogenesis in adult mammals.

Open-ended movements structure sensorimotor information in early human development

Human behaviors, with whole-body coordination, involve large-scale sensorimotor interaction. Spontaneous bodily movements in the early developmental stage potentially lead toward acquisition of such coordinated behavior. These movements presumably contribute to the structuration of sensorimotor interaction, providing specific regularities in bidirectional information among muscle activities and proprioception. Whether and how spontaneous movements, despite being task-free, structure and organize sensorimotor interactions in the entire body during early development remain unknown. Herein, to address these issues, we gained insights into the structuration process of the sensorimotor interaction in neonates and 3-mo-old infants. By combining detailed motion capture and musculoskeletal simulation, sensorimotor information flows among muscle activities and proprioception throughout the body were obtained. Subsequently, we extracted spatial modules and temporal state in sensorimotor information flows. Our approach demonstrated that early spontaneous movements elicited body-dependent sensorimotor modules, revealing age-related changes in them, depending on the combination or direction. The sensorimotor interactions also displayed temporal non-random fluctuations analogous to those seen in spontaneous activities in the cerebral cortex and spinal cord. Furthermore, we found recurring state sequence patterns across multiple participants, characterized by a substantial increase in infants compared to the patterns in neonates. Therefore, early spontaneous movements induce the spatiotemporal structuration in sensorimotor interactions and subsequent developmental changes. These results implicated that early open-ended movements, emerging from a certain neural substrate, regulate the sensorimotor interactions through embodiment and contribute to subsequent coordinated behaviors. Our findings also provide a conceptual linkage between early spontaneous movements and spontaneous neuronal activity in terms of spatiotemporal characteristics.

Diagnostic and surgical management of primary central nervous system angioleiomyoma: A case report and literature review

Angioleiomyoma (ALM) is a benign smooth muscle neoplasm that mainly occurs in lower extremities subcutaneous tissue and generally affects middle-aged adults. This tumor histotype may rarely localize intracranially, although only a few cases have been described in the literature. We report a case of intracranial ALM, whose differential diagnosis has been particularly challenging, and firstly provide a comprehensive radiological and intra-operative evaluation of a such rare entity. This represents also the first report of the use of intraoperative confocal microscopy in ALM and the first documented short-term recurrence. At this regard, a scoping literature review has been conducted with the aim of presenting the major clinical and diagnostic features along with the proposed therapeutic strategies.

Uterine Primitive Neuroectodermal Tumor

Uterine primitive neuroectodermal tumors (PNETs) are rare entities, with only around 70 cases published in the literature. Most of them are diagnosed in advanced stages with rapid progression and poor prognosis. Herein, we present a case of a 71-year-old patient with postmenopausal metrorrhagia and an ultrasound finding of endometrial thickening. The pathological diagnosis after an endometrial biopsy showed PNET. In the study of extension, possible distant dissemination with infiltration of the sigmoid and liver was observed. Chemotherapy treatment was proposed, but not begun due to the rapid progression of the disease. Four months after the initial diagnosis, the patient died of multiple organ failure. While there is no optimal chemotherapy treatment regimen for PNET, some studies have reported encouraging results. It is necessary to publish more studies emphasizing the follow-up and survival of the disease to establish which may be the best treatment option and thus improve the current poor prognosis.

A fenestrated persistent primitive hypoglossal artery harboring a ruptured aneurysm: A case report

RATIONALE

Persistent primitive hypoglossal artery (PPHA) is a rare and permanent carotid-vertebrobasilar anastomoses. Patients with PPHA usually have higher changes of developing intracranial aneurysms due the high intracranial hemodynamics. Although cases of PPHA alone and PPHA with aneurysms have been reported in literature, cases of fenestrated PPHA harboring a ruptured aneurysm have seldomly be reported in literature. We present a rare occurrence of a fenestrated PPHA harboring a reputed aneurysm.

PATIENTS CONCERNS

A 43-year-old woman was presented with a sudden-onset severe headache and nausea.

DIAGNOSIS

Computerized tomography scan showed third, fourth, and bilateral ventricular hemorrhages. Computed tomographic angiogram showed a PPHA with fenestration malformation and a cystic protrusion consistent with an aneurysm.

INTERVENTION

The patient underwent a successful stent-assisted coil embolization via the trans-arterial route under general anesthesia.

OUTCOMES

Two years follow-up revealed no recurrence of her symptomatology and she is currently well and go about her normal daily life.

CONCLUSION

Fenestrated PPHAs harboring aneurysms may be more prone to rupture because of the fenestration and connective tissue weakness of the artery as well as changes in hemodynamics of the already malformed and weak artery.

[Malignant mesothelioma of the ovary: a case report]

Le mésothéliome malin primitif de l´ovaire (MMPO) est une tumeur extrêmement rare qui peut se développer à partir des cellules mésothéliales. Cette néoplasie est causée principalement par une exposition à l´amiante ou à d´autres agents cancérigènes. Un bilan d´extension préopératoire comportant une tomodensitométrie, une imagerie par résonance magnétique et une tomographie par émission de positons est essentiel pour la stadification de la maladie. Le diagnostic positif anatomopathologique repose sur un panel immunohistochimique. Le MMPO reste une maladie exceptionnelle impliquant une stratégie thérapeutique multidisciplinaire, au sein de laquelle la chimiothérapie a permis d´améliorer la prise en charge et le pronostic de ces malades. Nous présentons dans cet article le cas d´une patiente ayant subi une chirurgie suboptimale, complétée par une chimiothérapie adjuvante, aboutissant à une réponse complète radiologique, avec une survie sans maladie de plus d´une année.

Being white, being Jungian: implications of Jung's encounter with the 'non-European' other1

This personal account charts the changing relationship to a Jungian identity arising from the interrelated processes of understanding the roots of the colonial and racial ideologies that underpin Jung's thinking, and a developing awareness of what it means to be a white person in a system of racism that maintains white supremacy. This is illustrated with reference to the image of a black man appearing in the dream of the white author and with use of post-Jungian thinking to critique the notion of an objective, non-racial psyche.

[Bilateral parotid'primary tuberculosis,a case study]

We report a case of bilateral Primary tuberculosis of the parotid gland that evolve more than one year, in a 35 years old patient, without any pathologic antecedent, where physical examination showed bilateral parotid swelling, in a context of conservation of general state. Ultrasound showed parotids increased in volume, heterogeneous with many fluid tissue formations, whose largest voluminous at right measure 28 millimeters, against 25 millimeters at left, with necrosis areas. The scan showed homogenous tissue density lesions, enhanced after contrast product injection. The fine needle aspiration was in favor of granulomatous lymphadenitis, suggestive of tuberculosis. Intradermoreaction to tuberculin was positive (15 millimeters in diameter).

The diagnosis of bilateral primary tuberculosis of the parotid was retained. A 6 months antituberculosis medical treatment was established with disappearance of parotid swelling, without recidive or others complications, on a decline of 14 months after treatment.

Peripheral primitive neuroectodermal tumors: A retrospective analysis of 89 cases and literature review

Peripheral primitive neuroectodermal tumors (pPNETs) are rare, small cell carcinomas with a poor prognosis. The aim of the present study was to describe therapeutic approaches, outcomes and probable prognostic factors. The clinical features, treatments, and outcomes of 89 consecutive patients with pPNET treated at the Peking Union Medical College Hospital from 1999 to 2018 were retrospectively reviewed. A total of 43 males and 46 females were included in the study, with a median age of 25 years (range, 5-73 years). The predominantly affected regions were the abdomen and pelvis, followed by the thoracopulmonary region. The mean primary tumor size was 12.6 cm (range, 1-30 cm). A total of 16 patients (18%) initially presented with metastasis. A total of 46 patients received combined therapy, 35 received mono-therapy, and 8 underwent only biopsy with no further treatment. The period of observation ranged from 1-232 months. The median overall survival (OS) time was 15 months [95% confidence interval (CI), 9-21 months], with 3- and 5-year OS rates of 32 and 25%, respectively. Large tumor size [adjusted hazard ratio (aHR)=3.65; 95% CI, 2.07-6.42; P<0.001), metastasis at initial presentation (aHR=4.34, 95% CI, 2.23-8.42; P<0.001), and combined modality treatment (aHR=0.16, 95% CI, 0.06-0.39; P<0.001) were significantly associated with OS. The prognosis of pPNET is, overall, poor. Large tumor size and metastasis at initial presentation are associated with poorer outcomes. This highly malignant tumor requires an aggressive combination of radical resection, chemotherapy and radiotherapy, when indicated.

A Taxonomy of Functional Upper Extremity Motion

Background: Functional upper extremity (UE) motion enables humans to execute activities of daily living (ADLs). There currently exists no universal language to systematically characterize this type of motion or its fundamental building blocks, called functional primitives. Without a standardized classification approach, pooling mechanistic knowledge and unpacking rehabilitation content will remain challenging.

Methods: We created a taxonomy to characterize functional UE motions occurring during ADLs, classifying them by motion presence, temporal cyclicity, upper body effector, and contact type. We identified five functional primitives by their phenotype and purpose: reach, reposition, transport, stabilize, and idle. The taxonomy was assessed for its validity and interrater reliability in right-paretic chronic stroke patients performing a selection of ADL tasks. We applied the taxonomy to identify the primitive content and motion characteristics of these tasks, and to evaluate the influence of impairment level on these outcomes.

Results: The taxonomy could account for all motions in the sampled activities. Interrater reliability was high for primitive identification (Cohen's kappa = 0.95–0.99). Using the taxonomy, the ADL tasks were found to be composed primarily of transport and stabilize primitives mainly executed with discrete, proximal motions. Compared to mildly impaired patients, moderately impaired patients used more repeated reaches and axial-proximal UE motion to execute the tasks.

Conclusions: The proposed taxonomy yields objective, quantitative data on human functional UE motion. This new method could facilitate the decomposition and quantification of UE rehabilitation, the characterization of functional abnormality after stroke, and the mechanistic examination of shared behavior in motor studies.

Cervicomedullary primitive neuroectodermal tumor of the spine: Case report

Background

Intramedullary primitive neuroectodermal tumors (PNETs) are tumors found rarely in the cervical region, with only five such cases described in the literature. The available literature contains only one report regarding cervicomedullary junction PNET.

Case Description

The authors present a case report of a 45-year-old male patient who had undergone urgent hospitalization owing to progressive tetraparesis and subtle impairment of respiratory function. He underwent magnetic resonance imaging, which showed an extensive enhancing cervical intramedullary tumor extending from C5 to the bulbar region. Since he developed severe impairment of respiratory function, he required tracheostomy. He then underwent microsurgery 2 days after his admission, and a partial tumor resection was performed. The pathological diagnosis of PNET of the cervicomedullary junction (CMJ) was made. He had slight worsening of strength after surgery with subsequent deterioration over the next 3 weeks. The tumor displayed aggressive growth; thus, radiotherapy was indicated. Unfortunately, he developed severe febrile neutropenia and died after 2 weeks of radiotherapy. Given the rarity of the condition, we wish to review the epidemiology, pathophysiology, and treatment options of his population.

Conclusion

Intramedullary PNETs of the cervical spine and CMJ are exceedingly rare in adults; treatment of such patients remains a challenge, despite the modern neurosurgical armamentarium that is available.

Synergies in coordination: a comprehensive overview of neural, computational, and behavioral approaches

At face value, the term "synergy" provides a unifying concept within a fractured field that encompasses complementary neural, computational, and behavioral approaches. However, the term is not used synonymously by different researchers but has substantially different meanings depending on the research approach. With so many operational definitions for the one term, it becomes difficult to use as either a descriptive or explanatory concept, yet it remains pervasive and apparently indispensable. Here we provide a summary of different approaches that invoke synergies in a descriptive or explanatory context, summarizing progress, not within the one approach, but across the theoretical landscape. Bernstein's framework of flexible hierarchical control may provide a unifying framework here, since it can incorporate divergent ideas about synergies. In the current motor control literature, synergy may refer to conceptually different processes that could potentially operate in parallel, across different levels within the same hierarchical control scheme. There is evidence for the concurrent existence of synergies with different features, both "hard-wired" and "soft-wired," and task independent and task dependent. By providing a comprehensive overview of the multifaceted ideas about synergies, our goal is to move away from the compartmentalization and narrow the focus on one level and promote a broader perspective on the control and coordination of movement.

Late onset of primary pulmonary primitive neuroectodermal tumor: a case report

Lungs are one of most metastatic areas for primitive neuroectodermal tumor (PNET), however primary pulmonary PNET is extremely rare. Here we present a case of a 58-year-old male patient with a tumor in the right lung that originated from the lung but not from chest wall. Patient was diagnosed with PNET following histological and immunohistochemical examination of CT-guided percutaneous tru-cut needle biopsy and no distant metastasis were detected in PET-CT scan. As advised recently in published literature, surgical resection following neoadjuvant chemotherapy protocol is preferred in the treatment of our patient as it has better success of complete resection leading to higher 5-year survival rates. Although primary pulmonary PNET is uncommon, it should be taken into account and complete surgical resection should be aimed as treatment to achieve higher survival rates.

Induced-Pluripotent-Stem-Cell-Derived Primitive Macrophages Provide a Platform for Modeling Tissue-Resident Macrophage Differentiation and Function

Tissue macrophages arise during embryogenesis from yolk-sac (YS) progenitors that give rise to primitive YS macrophages. Until recently, it has been impossible to isolate or derive sufficient numbers of YS-derived macrophages for further study, but data now suggest that induced pluripotent stem cells (iPSCs) can be driven to undergo a process reminiscent of YS-hematopoiesis in vitro. We asked whether iPSC-derived primitive macrophages (iMacs) can terminally differentiate into specialized macrophages with the help of growth factors and organ-specific cues. Co-culturing human or murine iMacs with iPSC-derived neurons promoted differentiation into microglia-like cells in vitro. Furthermore, murine iMacs differentiated in vivo into microglia after injection into the brain and into functional alveolar macrophages after engraftment in the lung. Finally, iPSCs from a patient with familial Mediterranean fever differentiated into iMacs with pro-inflammatory characteristics, mimicking the disease phenotype. Altogether, iMacs constitute a source of tissue-resident macrophage precursors that can be used for biological, pathophysiological, and therapeutic studies.

[Primary intramuscular non-Hodgkin's lymphoma in young subjects: about a case and review of the literature]

Primary extra-ganglionic non-Hodgkin's lymphoma (NHL) is rare and its primary intramuscular location is exceptional, as it account for less than 0.5% of all patients. It generally affects men, with an average age of 70 years. Standard treatment is based on surgical excision combined with chemotherapy and radiation therapy. We report the case of a 31-year old patient presenting with muscular pseudotumoral syndrome at the level of the right leg. Histological examination showed intramuscular large B-cell non-Hodgkin's lymphoma. The patient underwent exclusive chemotherapy with complete remission.

[Undifferentiated liver liposarcoma: about a case]

Le liposarcome est une tumeur mésenchymateuse maligne rare, qui siège plus fréquemment au niveau du retro péritoine. La localisation hépatique est extrêmement rare, quelques cas ont été rapportés dans la littérature. Nous présentons le cas d'un un patient de 58 ans, qui se présente pour douleurs abdominales avec à la palpation une masse de hypochondre droit, ayant progressivement augmenté de taille. L'échographie abdominale a montré une masse arrondie, hyper échogène bien limitée. La tomodensitométrie(TDM) abdominale et l'imagerie par résonnance magnétique(IRM) ont confirmé la présence d'une masse qui occupe presque la totalité du foie droit, avec une composante graisseuse. Le patient a bénéficié d'une hépatectomie droite et l'analyse histologique a montrée qu'il s'agissait d'un liposarcome hépatique primitif dédifférencié.

Hematopoietic stem cell-independent hematopoiesis: emergence of erythroid, megakaryocyte, and myeloid potential in the mammalian embryo

Steady-state production of all circulating blood cells in the adult ultimately depends on hematopoietic stem cells (HSCs), which first arise in small numbers beginning at embryonic day (E) 10.5 in large arterial vessels of the murine embryo. However, blood cell synthesis first begins in the yolk sac beginning at E7.25 and consists of two waves of hematopoietic progenitors. The first wave consists of primitive erythroid, megakaryocyte, and macrophage progenitors that rapidly give rise to maturing blood cells of all three lineages. This 'primitive' wave of progenitors is followed by a partially overlapping wave of 'erythro-myeloid progenitors', which contain definitive erythroid, megakaryocyte, macrophage, neutrophil, and mast cell progenitors that seed the fetal liver and jump-start hematopoiesis before the engraftment and expansion of HSCs. These two waves of progenitors that arise in the yolk sac are necessary and even sufficient to sustain the survival of the mouse embryo until birth in the absence of HSCs. They provide key signals to support HSC emergence. Finally, HSC-independent hematopoiesis also provides long-lived tissue-resident macrophage populations that function in multiple adult organs.

[Clinical aspects of primary lung cancers in the cancer ward of CHUA-HUJRA Antananarivo]

Le retard de diagnostic des cancers broncho-pulmonaires est l'une des sources du retard de leur prise en charge dans les pays en développement. A notre connaissance, l'aspect clinique des cancers broncho-pulmonaires au Centre Hospitalier Universitaire d'Antananarivo-Hôpital Universitaire Joseph Ravoahangy Andrianavalona (CHUA-HUJRA) n'a jamais été étudié. L'objectif était de décrire les aspects cliniques des cancers broncho-pulmonaires primitifs dans le plus grand centre de cancérologie de Madagascar. C'est une étude rétrospective et descriptive des patients atteints de cancers broncho-pulmonaires primitifs vus au service d'oncologie du CHUA-HUJRA du 1er janvier 2008 au 31 décembre 2013. Nous avons recensé 101 patients (80 hommes et 21 femmes). Les circonstances de découverte sont principalement la toux chronique (n = 29), la dyspnée (n = 16) et l'association d'une hémoptysie à la toux chronique (n = 12). Soixante et onze patients avaient un index de performans status ≥ à 2 au moment du diagnostic. On a retrouvé des bacilles de Koch actives dans le crachat de deux patients. Le délai moyen entre l'apparition des premiers signes et la première consultation était de 11 mois. Le délai moyen entre la première consultation et le diagnostic anatomopathologique était de 3 mois. Le cancer broncho-pulmonaire peut avoir des manifestations cliniques non spécifiques parfois trompeuses qui peuvent retarder leur prise en charge. De ce fait, il doit être recherché devant tout signe respiratoire persistant. Par ailleurs, le délai de prise en charge pré-hospitalière et hospitalière de ces cancers doit être amélioré.

[Primitive mammary hydatid cyst]

La localisation mammaire du kyste hydatique est exceptionnelle. De ce fait, le diagnostic est difficile avant l'examen anatomopathologique. Nous rapportons une observation d'un cas de kyste hydatique du sein chez une femme de 32 ans, qui consultait pour un nodule du sein, dont l'imagerie montrait une lésion en rétro-aréolaire du sein gauche, homogène, ovalaire et de contours réguliers. L'examen anatomopathologique objectivait un kyste hydatique à localisation mammaire. Les suites opératoires étaient simples. L'hydatidose est une maladie ubiquitaire, pouvant atteindre tous les organes. Le diagnostic peut être évoqué devant une masse kystique du sein avec des aspects très évocateurs à l'imagerie. La confirmation du diagnostic n'est confirmée qu'après une cytoponction ou une chirurgie d'exérèse qui réalise le traitement de cette pathologique. La négativité du bilan d'extension hydatique permet de retenir une localisation primitive de l’échinococcose.

[Primitive omental appendagitis: a rare cause of abdominal pain]

Les appendagites sont une cause rare de douleur abdominale chez l'adulte, elles simulent souvent le tableau d'une appendicite aiguë ou une sigmoïdite, le diagnostic est souvent poser par une TDM ou lors d'un acte chirurgicale, le traitement est essentiellement médicale.

[Primary osteosarcoma of the thigh: about a case]

À travers cette observation d'ostéosarcome extra-osseux de localisation atypique, le diagnostic clinique et radiologique, ainsi que le profil épidémiologique de cette entité pathologique sont discutés. Patient de 64 ans consultait pour tuméfaction évolutive douloureuse de la cuisse droite qui évoluait depuis plus de 03 ans. Ce patient avait bénéficié d'une TDM, d'une IRM puis d'une scintigraphie osseuse. Une exérèse chirurgicale de la tumeur avait été réalisée. L'analyse histopathologique de la pièce opératoire concluait à un ostéosarcome conventionnel extra osseux. Le patient a été adressé en oncologie pour complément de prise en charge. L'ostéosarcome extra squelettique occupe typiquement une situation profonde, sans lien avec l'os ou le périoste adjacent. Le pronostic est mauvais.

Pleuropulmonary blastoma in adolescence: A rare tumor beyond first decade of life

Pleuropulmonary blastoma (PPB) is a unique dysontogenetic and a primitive neoplasm occuring almost exclusively in the first decade of life, as a pulmonary- and/or pleural-based tumor with cystic, solid, or combined cystic and solid features. It is characterized histologically by a primitive, variably mixed blastematous and sarcomatous tissues. These tumors are usually associated with a poor prognosis. However, with a multimodality treatment approach, the survival of the patient can be prolonged. We herein report two cases of PPB in adolescence, a rare presentation beyond first decade of life with a short review of literature.

[Bilateral primitive non-Hodgkin Lymphoma of the breast: about a case]

Les lymphomes malins non-hodgkiniens (LMNH) primitifs du sein sont des tumeurs rares. Leur symptomatologie clinique est polymorphe. L'imagerie médicale est non-spécifique. Le diagnostic peut être évoqué à l'examen cytologique, sa confirmation est toujours histologique. Il s'agit essentiellement de lymphomes de type B, ceux de type NK/T restant rares. Les plus fréquents sont les lymphomes diffus à grandes cellules présentant la particularité de donner des rechutes sous forme d'extension au système nerveux central. Nous rapportons un cas de LMNH primitif bilatéral du sein chez une patiente âgée de 33 ans, révélé par deux nodules mammaires bilatéraux. La mammographie et l'examen extemporané ont évoqué une tumeur phyllode. Le diagnostic du LMNH n'a été fait qu'après examen histologique définitif. Sous chimiothérapie, l’évolution était favorable avec un recul de 15 mois.

Changing patterns of antigen exposure and their impact on the prevalence of allergy

Industrial development has advanced at a varying pace in different parts of the world over the past 200 years. Inhabitants of the most industrially advanced regions have experienced major changes in patterns of antigen exposure to infectious agents and to environmental biologic substances. This article analyzes the major factors that affect the amounts and variety of antigens to which the immune system of a young child is exposed. Depending on individual living environments and lifestyles, the types of antigen exposure of young children are graded into five patterns: 'primitive', 'pre-modern', 'early modern', 'modern', and 'ultramodern'. These patterns represent increasing deviation from the pattern of human immune system exposure to antigens prior to the industrial revolution. This article further discusses how such changes in antigen exposure have affected the immunologic system, especially with regard to the development of total IgE and allergic response-relevant antigen-specific IgE, and how the patterns of antigen exposure are related to the propensity to develop allergy.

Primitive neuroectodermal tumour of pancreas; second case from Asia

Primitive neuroectodermal tumours (PNETs) are malignant tumours composed of small round cells of neuroectodermal origin that affect soft tissue and bone. PNETs originating in the pancreas are extremely rare; previous to this report, only 14 cases were reported worldwide, making this case the fifteenth in the world and the second in Asia. We present the case of a painful pancreatic lump diagnosed as PNET of the pancreas after a thorough workup. The diagnosis of PNET is made according to the overall clinical picture, imaging, histopathology, cytogenetics, and immunohistochemistry, as in the case we present. It is essential to differentiate primary pancreatic PNET from a secondary involvement. A review of all of the cases diagnosed worldwide thus far is also provided.

Primary fallopian tube carcinoma: a case report

Primary cancer of the fallopian tube is very rare and their preoperative diagnosis is difficult due to the lack of specific symptoms. We report a case in a patient aged 42 years, discovered after abdominopelvic mass. Total surgery was performed, followed by platinum-based chemotherapy. The authors report a review of the literature regarding the epidemiology, diagnosis, treatment and prognosis of this cancer.

Dynamic primitives in the control of locomotion

Humans achieve locomotor dexterity that far exceeds the capability of modern robots, yet this is achieved despite slower actuators, imprecise sensors, and vastly slower communication. We propose that this spectacular performance arises from encoding motor commands in terms of dynamic primitives. We propose three primitives as a foundation for a comprehensive theoretical framework that can embrace a wide range of upper- and lower-limb behaviors. Building on previous work that suggested discrete and rhythmic movements as elementary dynamic behaviors, we define submovements and oscillations: as discrete movements cannot be combined with sufficient flexibility, we argue that suitably-defined submovements are primitives. As the term “rhythmic” may be ambiguous, we define oscillations as the corresponding class of primitives. We further propose mechanical impedances as a third class of dynamic primitives, necessary for interaction with the physical environment. Combination of these three classes of primitive requires care. One approach is through a generalized equivalent network: a virtual trajectory composed of simultaneous and/or sequential submovements and/or oscillations that interacts with mechanical impedances to produce observable forces and motions. Reliable experimental identification of these dynamic primitives presents challenges: identification of mechanical impedances is exquisitely sensitive to assumptions about their dynamic structure; identification of submovements and oscillations is sensitive to their assumed form and to details of the algorithm used to extract them. Some methods to address these challenges are presented. Some implications of this theoretical framework for locomotor rehabilitation are considered.

Dynamic primitives of motor behavior

We present in outline a theory of sensorimotor control based on dynamic primitives, which we define as attractors. To account for the broad class of human interactive behaviors-especially tool use-we propose three distinct primitives: submovements, oscillations, and mechanical impedances, the latter necessary for interaction with objects. Owing to the fundamental features of the neuromuscular system-most notably, its slow response-we argue that encoding in terms of parameterized primitives may be an essential simplification required for learning, performance, and retention of complex skills. Primitives may simultaneously and sequentially be combined to produce observable forces and motions. This may be achieved by defining a virtual trajectory composed of submovements and/or oscillations interacting with impedances. Identifying primitives requires care: in principle, overlapping submovements would be sufficient to compose all observed movements but biological evidence shows that oscillations are a distinct primitive. Conversely, we suggest that kinematic synergies, frequently discussed as primitives of complex actions, may be an emergent consequence of neuromuscular impedance. To illustrate how these dynamic primitives may account for complex actions, we briefly review three types of interactive behaviors: constrained motion, impact tasks, and manipulation of dynamic objects.

Individual premotor drive pulses, not time-varying synergies, are the units of adjustment for limb trajectories constructed in spinal cord

Complex actions may arise by combining simple motor primitives. Our studies support individual premotor drive pulses or bursts as execution primitives in spinal cord. Alternatively, the fundamental execution primitives at the segmental level could be time-varying synergies. To distinguish these hypotheses, we examined sensory feedback effects during targeted wiping organized in spinal cord. This behavior comprises three bursts. We tested (1) whether feedback altered the structure of individual premotor drive bursts or primitives, and (2) whether feedback differentially modulated different drive bursts or pulses in the three burst sequence. At least two of the three bursts would need to always be comodulated to support a time-varying synergy. We used selective muscle vibration to control spindle feedback from a single muscle (biceps/iliofibularis). The structures of premotor drive bursts were conserved. However, biceps vibration (1) scaled the amplitudes of two bursts coactivated during the initial phase of wiping independently of one another without altering their phase, and (2) independently phase regulated the third burst but preserved its amplitude. Thus, all three bursts were regulated separately. Durations were unaffected. The independent effects depended on (1) time of vibration during wiping, (2) frequency of vibration, and (3) limb configuration. Because each of the three bursts was independently modulated, these data strongly support execution using individual premotor bursts rather than time-varying synergies at the spinal level of motor organization. Our data show that both sensory feedback and central systems of the spinal cord act in concert to adjust the individual premotor bursts in support of the straight and unimodal wiping trajectory.

Primary pulmonary Ewing's sarcoma/primitive neuroectodermal tumor in a 67-year-old man

Extraskeletal Ewing's sarcoma (EES) is a branch of neuroectodermal tumor (PNET), which is very rare soft tissue sarcoma. We report a case of EES/PNET arising is the lung of a 67-yr-old man. Computed tomography, bone scintigraphy, and positron emission tomography confirmed the mass to have a primary pulmonary origin. The mass showed positive reactivity in the Periodic Acid Schiff (PAS) stain and MIC-2 immunoreactivity in immunohistochemical stain. Fluorescence in situ hybridization (FISH) was performed, which revealed an EWSR1 (Ewing sarcoma breakpoint region 1) 22q12 rearrangement. The diagnosis was confirmed both pathologically and genetically. The mass lesion was resected, and the patient is currently undergoing chemotherapy.

Rapid correction of aimed movements by summation of force-field primitives

Spinal circuits form building blocks for movement construction. In the frog, such building blocks have been described as isometric force fields. Microstimulation studies showed that individual force fields can be combined by vector summation. Summation and scaling of a few force-field types can, in theory, produce a large range of dynamic force-field structures associated with limb behaviors. We tested for the first time whether force-field summation underlies the construction of real limb behavior in the frog. We examined the organization of correction responses that circumvent path obstacles during hindlimb wiping trajectories. Correction responses were triggered on-line during wiping by cutaneous feedback signaling obstacle collision. The correction response activated a force field that summed with an ongoing sequence of force fields activated during wiping. Both impact force and time of impact within the wiping motor pattern scaled the evoked correction response amplitude. However, the duration of the correction response was constant and similar to the duration of other muscles activated in different phases of wiping. Thus, our results confirm that both force-field summation and scaling occur during real limb behavior, that force fields represent fixed-timing motor elements, and that these motor elements are combined in chains and in combination contingent on the interaction of feedback and central motor programs.