Coregulation of anterior and posterior mesendodermal development by a hairy-related transcriptional repressor

During embryonic development in vertebrates, the endoderm becomes patterned along the anteroposterior axis to produce distinct derivatives. How this regulation is controlled is not well understood. We report that the zebrafish hairy/enhancer of split [E(spl)]-related gene her5 plays a critical role in this process. At gastrulation, following endoderm induction and further cell interaction processes including a local release of Notch/Delta signaling, her5 expression is progressively excluded from the presumptive anterior- and posteriormost mesendodermal territories to become restricted to an adjacent subpopulation of dorsal endodermal precursors. Ectopic misexpressions of wild-type and mutant forms of her5 reveal that her5 functions primarily within the endodermal/endmost mesendodermal germ layer to inhibit cell participation to the endmost-fated mesendoderm. In this process, her5 acts as an active transcriptional repressor. These features are strikingly reminiscent of the function of Drosophila Hairy/E(spl) factors in cell fate decisions. Our results provide the first model for vertebrate endoderm patterning where an early regulatory step at gastrulation, mediated by her5 controls cell contribution jointly to the anterior- and posteriormost mesendodermal regions.

Residual lesions after Kasabach-Merritt phenomenon in 41 patients

BACKGROUND

Kasabach-Merritt phenomenon (KMP) is the association of a vascular tumor and thrombocytopenic coagulopathy. Vascular tumors are either kaposiform hemangioendothelioma or tufted angioma but not "true" common hemangioma of infancy. There is a conspicuous absence in the literature regarding the late outcome and possible residual lesions after apparent clinical cure of KMP.

OBJECTIVE

The purpose of the study was to analyze these residua in a large number of patients.

METHODS

Clinical data on 41 patients who had KMP were accrued in an international cooperative study. The emphasis was on the residual lesions after resolution of the thrombocytopenia and other coagulation abnormalities. Imaging studies (follow-up magnetic resonance imaging studies available for 10 patients) and histologic specimens (30 specimens available for 26 patients, 18 biopsies done during the KMP and 12 concerning the sequelae) were reviewed.

RESULTS

Residual lesions after "cure" of KMP were common. They exhibited 3 clinical patterns: type I lesions (n = 28) showed a cutaneous red stain, with or without associated red papules. The stain might overlap a minor fibrotic infiltration or a significant poorly delineated diffuse fibrotic infiltration. These cutaneous vascular lesions varied in size and appearance over time and were occasionally painful. Type II lesions were telangiectatic streaks and swelling (n = 5), and type III lesions showed a minor, firm, irregular, subcutaneous mass assessed by palpation or deep infiltration evidenced by computed tomography or magnetic resonance imaging (n = 8). A fourth feature was sequelae in muscles and/or joints. Histologically, tufted angioma was more common in the specimens from residual lesions, whereas kaposiform hemangioendothelioma was more common during the active phase of KMP. Imaging findings were remarkably reproducible and revealed a persistent vascular tumor.

CONCLUSION

Residua of tumors associated with KMP are common after the resolution of thrombocytopenia and coagulopathy. They are (more or less) prominent dormant vascular tumors, not "scars" and, clinically as well as histologically, they differ markedly from involuted hemangioma.

[An unusual primary vascular tumor: intimal sarcoma of the pulmonary artery]

Primary sarcomas of great vessels are rare and involve the aorta, pulmonary artery and inferior vena cava. The pathologic classification of these tumors can be made on the location of the sarcoma in relation to the vessel wall, luminal or mural. Luminal sarcomas are usually intimal sarcoma and mural sarcoma are most frequently leiomyosarcoma. The myofibroblastic or endothelial differentiation of these tumors is still debated. We report a case of intimal sarcoma of the pulmonary artery.

Spinal melanotic schwannoma: a tumour with poor prognosis

AIM

To clarify the prognosis of melanotic schwannoma. This is a rare tumour which is generally considered as a benign lesion, reported in many cases with a short follow-up only.

METHODS AND RESULTS

Five cases of spinal melanotic schwannoma were retrospectively studied. The tumours were examined using standard histological, immunohistochemical and ultrastructural methods. No features of malignancy (high mitotic count, atypia or necrosis) were found in the primary tumours. The follow-up period ranged from 3 to 7 years. Malignant clinical behaviour was clear-cut in four cases: three patients died from metastases to various sites and one presented several discrete spinal tumours of the same type seven years after the first operation. Only one patient presented no recurrence and was free of disease 6 years after initial diagnosis. The review of 57 cases of the literature (including our cases), showed that 15% of the cases had recurrences and 26.3% were complicated by metastasis. Only 53% of the cases followed for more than 5 years, were free of disease vs. 67.5% of the cases with shorter follow-up. Twenty additional cases had no follow-up.

CONCLUSION

Appropriate long-term follow-up is required for all melanotic schwannomas, as it may recur or metastasize after more than 5 years, even in the absence of overt malignant histological features.

Phenotypic and functional characteristics of porcine peritoneal mesothelial cells

The objective of this study was to establish a technique to isolate porcine mesothelial cells (PMCs) from omental tissue and to compare them to human mesothelial cells (HMCs). The PMCs were dispersed by collagenase digestion and isolated on a Ficoll layer. Their morphologic and ultrastructural features were assessed at confluence by light and electronic microscopy, and they were characterized by immunohistochemistry using specific HMC markers. PMC proliferation was studied in the presence of growth factors platelet-derived growth factor (PDGF), epidermal growth factor (EGF) or transforming growth factors beta1, beta2, or beta3 (TGF). Fibrinolytic PMC activity was detected by zymography for tissue plasminogen activator (tPA) and by reverse zymography for plasminogen activator inhibitor-1 (PAI-1). The recalcification time of cell lysates was used to define PMC procoagulant activity, and gelatinase zymography was used to detect metalloproteinase production. At confluence, PMCs formed typical cobblestone monolayers and exhibited structural features characteristic of HMCs. Weibel Palade bodies were never seen. Specific HMC markers (HBME1, ME1, WT1) cross-reacted with PMCs. As HMCs and PMCs coexpressed cytokeratin and vimentin, and also expressed vinculin and alpha-actin. Addition of PDGF or EGF to the culture medium stimulated PMC proliferation. PMCs constitutively expressed fibrinolytic and procoagulant activity and secreted MMP9 and MMP2. The technique described in this study allows isolation of mesothelial cells from porcine omental tissue. These porcine cells exhibit a mesothelial phenotype and functional properties similar to those of HMCs. Our data warrant an evaluation of mesothelial cells as targets in several therapeutic strategies with porcine models.

Role of thalamic axons in the expression of H-2Z1, a mouse somatosensory cortex specific marker

In the H-2Z1 mouse line, postnatal expression of the lacZ containing transgene in the cerebral cortex is restricted to layer IV neurons of the somatosensory area. We have used H-2Z1 embryos in previous heterotopic transplantation experiments to investigate the chronology of determination of areal identity. From the onset of neurogenesis, the cortex was regionalized in domains fated to express or not the somatosensory area-specific transgene. Determination occured 1 day later. In the present study, we show that, in vivo, H-2Z1 expression coincides with invasion of the cortical plate by thalamic afferents. We therefore investigated the role of thalamic innervation in the onset of H-2Z1 expression. For this purpose, we examined the pattern of H-2Z1 expression in perinatal cortical explant, in reeler mutant and MaoA deficient mice, or in animals which had received neonatal lesions affecting the somatosensory cortex or the thalamocortical projection. We found that, around birth, a switch occurs in the control of H-2Z1 expression: whereas H-2Z1 expression developed autonomously in embryonic parietal cortex in the absence of thalamic fibers, a transient requirement for a thalamic axon derived signal was observed postnatally. This property has interesting implications for the plasticity of cortical areas in development and evolution.

Specification of somatosensory area identity in cortical explants

The H-2Z1 transgene is restricted to a subset of layer IV neurons in the postnatal mouse cortex and delineates exactly the somatosensory area. Expression of the H-2Z1 transgene was used as an areal marker to determine when the parietal cortex becomes committed to a somatosensory identity. We have shown previously that grafts dissected from embryonic day 13.5 (E13.5) H-2Z1 cortex and transplanted into the cortex of nontransgenic newborns express H-2Z1 according to their site of origin. Expression was not modified on heterotopic transplantation (). In the present study, whole cortical explants were isolated at E12.5 from noncortical tissues. The explants developed a regionalized expression of H-2Z1, indicating that regionalization takes place and is maintained in vitro. We used this property and confronted embryonic H-2Z1 cortex with presumptive embryonic sources of regionalizing signals in an in vitro grafting procedure. A great majority of E11.5-E13.5 grafts maintained their presumptive expression of H-2Z1 when grafted heterotopically on nontransgenic E13.5-E15.5 explants. However, a significantly lower proportion of E11.5 parietal grafts expressed H-2Z1 in occipital compared with parietal cortex, indicating that somatosensory identity may be partially plastic at E11.5. Earlier stages could not be tested because the E10.5 grafts failed to develop in vitro. The data suggest that commitment to the expression of a somatosensory area-specific marker coincides with the onset of neurogenesis and occurs well before the birth of the non-GABAergic neurons that express H-2Z1 in vivo.

Protective effects of Celsior in lung transplantation

BACKGROUND

Celsior is a new preservation solution for heart transplants that recently has been shown also to improve protection of pulmonary grafts. As these data were obtained in isolated lung preparations, we sought to perform further tests with an in vivo model of allogeneic lung transplantation.

METHODS

The left lungs of 41 rats were either transplanted immediately after harvest (controls) or flushed with and cold stored in Celsior or the blood-based Wallwork solution for 5 or 12 hours. Lungs were then reperfused for 30 minutes, after which ligation of the contralateral pulmonary artery and bronchus made the recipient rat exclusively dependent on the transplanted lung. Assessment of preservation was made on functional (blood gases, pulmonary hemodynamics) and structural (dry-to-weight ratio, light microscopy, myeloperoxidase [MPO] content) end points.

RESULTS

The protective effects of Celsior were primarily manifest, once the contralateral lung had been functionally excluded, as a better preservation of oxygen tensions in the 5-hour storage experiments (416 +/- 52 mm Hg vs 406 +/- 59 mm Hg in controls [p = NS] and vs 239 +/- 34 mm Hg in Wallwork [p < 0.05 vs the 2 other groups]) and a smaller increase in pulmonary vascular resistance in the 12-hour storage experiments (10.2 +/- 4.1 mm Hg/mL/minute vs 3.2 +/- 1.1 mm Hg/mL/minute in controls [p = NS] and vs 23.1 +/- 4.3 mm Hg/mL/minute in Wallwork [p < 0.02 vs Celsior, p < 0.002 vs controls]). Survival was also longer in the 12-hour preserved Celsior group. Other end points were not significantly different between the two preservative solutions.

CONCLUSION

These data support the efficacy of Celsior as a flush-out and storage solution for pulmonary grafts. Given its previously documented ability to adequately preserve heart transplants, Celsior might provide a unified "solution" to thoracic organ preservation.

Nasal haemangiopericytoma: report of two cases with literature review

Haemangiopericytoma (HPC) is a rare vascular tumour produced by proliferation of pericytes. One hundred and thirty-three cases of HPC have been reported in the nose and the paranasal sinuses. We present two more cases. Wide surgical excision via lateral rhinotomy, midfacial degloving, or endonasal removal is the treatment of choice. Radiotherapy has been used post-operatively in cases of incomplete removal. Life-long follow-up is required to evaluate local recurrence and late metastases.

Transnasal endoscopic removal of an orbital cavernoma

The approach to posterior and medial orbital tumors is still a challenge, since poor functional results are frequent. We report a case of cavernoma successfully removed by a modified transnasal endoscopic procedure. The patient, a 56-year-old woman, complained of a decrease in vision of the left eye. Magnetic resonance imaging evidenced a lesion in the posterior part of the orbital cavity, inferior to the optic nerve, extending to the sphenoidal cleft. The lesion was isodense on T1-weighted images and showed contrast enhancement. Because of the medial location of the tumor, the patient was referred to the otolaryngology department by the neurosurgeons, and a transnasal endoscopic approach was chosen. A large exposure of the operative field was obtained, and a cavernoma was removed. Rapid relief of the symptoms was obtained. In view of this good result, we advocate the transnasal endoscopic approach in cases of inferomedial and posterior intraconal lesions as an alternative and addition to the standard techniques of orbital surgery.

Cardiac papillary fibroelastoma: aA rare cause of ischemic stroke in the young

Among etiologies of stroke in young adults, primary cardiac tumors are very rare. We report the case of a 37-year-old woman who was admitted for an ischemic stroke in the right middle cerebral artery region. Etiologic investigations revealed, after transthoracic and transesophageal echocardiography, an aortic valve tumor. Treatment was first medical with anticoagulation, then surgical. Histological examination showed a papillary fibroelastoma. After a review of the literature, the possible mechanisms of the ischemic event are discussed and lead to the conclusion that this tumor must be surgically excised, even if asymptomatic, because of recurrent ischemic complications responsible for myocardial infarction, stroke and sudden death.

In vivo left ventricular function and collagen expression in aldosterone/salt-induced hypertension

Cardiac fibrosis is linked to aldosterone-induced hypertension, but the effects on in vivo left ventricular (LV) function are not established. We studied the relations between in vivo LV function and aldosterone/salt cardiac fibrosis. Adult guinea pigs (GPs) were treated for 3 months with an aldosterone infusion and high-salt diet. This treatment induced arterial hypertension (+35%) and moderate LV hypertrophy (LVH; +60%) without right ventricular (RV) hypertrophy. Echo-Doppler LV assessment demonstrated unaltered cardiac output, stroke volume, or LV relaxation. Type I collagen messenger RNA (mRNA) was significantly increased in both ventricles (LV, +48%; RV, +77%) and accompanied by a significant increase in total collagen deposition (LV, from 0.52% in controls to 4.4% in treated GPs; RV, from 0.82 to 5.5% in treated GPs). Plasma norepinephrine levels increased 2.6-fold (p < 0.01) and correlated with the increase in collagen deposition in both ventricles. Collagen content was not correlated with hypertension or LVH. We conclude that aldosterone administration induces cardiac collagen accumulation and a sympathetic stimulation, which might preserve systolic and diastolic function.

[Mallear epidermosis. An unusual form of open mucous otitis]

The presence of keratin in the middle ear cavity is usually associated with the diagnosis of cholesteatoma or epidermoid metaplasia. Analysis of a series of 18 cases suggests that it may correspond to a specific entity developing in the course of severe or long-lasting opened chronic otitis. This condition, we called mallear epidermosis, is characterized by: i) a perforation of the tympanic membrane lining the handle of the malleus and the umbo; ii) a proliferation of keratin surrounding the handle of the malleus and diffusing into the mesotympanum on the internal side of the tympanic membrane, without matrix; and iii) a mild inflammation of the middle ear epithelium. The process is usually limited to the mesotympanum and does not extend towards the attic and the posterior cavities. Epidemiological, clinical, pathophysiological, and histological features allow this entity to be distinguished from cholesteatoma and epidermoid metaplasia. Management is either medical consisting of local treatment and microaspiration, or surgical including resection of the umbo, removal of the tympanic membrane invaded by the adherent hyperkeratotic layers and repair by conventional underlay myringoplasty. This report emphasizes the need for a clear identification of the various types of chronic otitis media presenting with keratin in the middle ear, as they do not share the same course and do not require the same therapeutic management.

Nonpenetrating stapling: a valuable alternative for coronary anastomoses?

BACKGROUND

The safe development of minimally invasive coronary artery bypass operations might require alternatives to conventional suture-based anastomotic techniques. In this setting, nonpenetrating stapling is an attractive option because of its simplicity of use and potential for improved endothelial preservation.

METHODS AND RESULTS

In the experimental part of this study, porcine internal mammary arteries were anastomosed to left anterior descending coronary arteries using either an 8-0 polypropylene running suture or nonpenetrating microclips (7 anastomoses in each group). The endothelium-dependent relaxations to bradykinin of the arterial rings bearing the anastomosis and of noninstrumented rings were compared in organ chamber experiments. There were no significant differences in maximal relaxations (mean +/- SEM) between the microclipped and sutured anastomoses (81%+/-7% versus 74%+/-10%), which were both significantly lower than those of control coronary rings (98%+/-2%, p = 0.001 versus the two anastomosed groups). Histologic examination showed a comparable preservation of the coronary and graft endothelium with both techniques. The clinical part of the study comprised 7 patients in whom the left internal mammary artery was conventionally sutured to the left anterior descending whereas 13 saphenous vein grafts were anastomosed to their target vessels by nonpenetrating staples. There were no clip-related complications. An angiographic assessment of the venous grafts was performed within 10 days postoperatively in all patients. One graft is presumably occluded. The 12 remaining conduits were patent with stapled anastomoses featuring a widely open "shark-mouth" configuration.

CONCLUSIONS

These preliminary data suggest that non-penetrating stapling is an easy-to-use technique that competes well with conventional suturing, at least in terms of immediate results. Further studies are warranted to better define its potential place within the armamentarium of minimally invasive coronary artery bypass techniques.

Altered gap and tight junctions in human thyroid oncocytic tumors: a study of 8 cases by freeze-fracture

Human oncocytic tumors of the thyroid gland may be either adenomas or carcinomas. The morphology and the ultrastructure of these oncocytes are well-known. Numerous studies have demonstrated the role of gap and tight junctions in experimental and human carcinogenesis; however, the junctional complexes of the oncocytic tumors have never been studied. The aim of this study is to analyze gap and tight junctions in the oncocytic tumors of the thyroid. Because they are morphologically similar, whether benign or malignant, they offer an attractive model for studying the junctional complexes in both benign and malignant lesions. Eight oncocytic human thyroid tumors were collected and studied by freeze-fracture. Four of these cases were benign and four were malignant. Four cases of normal gland were also studied to represent the control group. Normal tight and gap junctions were described for the control group. No gap junctions could be found for the oncocytic tumors. Furthermore, alterations of the tight junctions were described; especially focal tights in the oncocytic adenomas and well organized and labyrinthic tight junctions in the oncocytic carcinomas. The lack of gap junction in the benign as well as in the malignant oncocytomas may suggest that the absence of gap junction is not sufficient for malignancy. The alterations of the tight junctions found in the oncocytic tumors of the thyroid are similar to those observed in poorly differentiated tissues or tumors, and may suggest a cellular regression rather than a tumorogenic factor.

[Sclerosing tufted angioma. Apropos of 4 cases involving lower limbs]

BACKGROUND

Tufted angioma belongs to the family of vascular skin proliferations. Clustered capillaries is the characteristic histological feature. Classically, tufted angioma is an acquired disease observed in children or young adults with lesions predominating on the neck, the shoulders and the upper trunk.

CASE REPORTS

Four children were seen for flat skin lesions which were either initially or secondarily erythematous. The lesions were observed at birth or within the first weeks of life. In all 4 cases, the lesions progressed by infiltration, leading to sclerous plaques within a few weeks. The hip area was involved in case n(o) 2 and the thigh in the other cases. Pathology reported tufted angioma. A repeated biopsy 4 years after the first biopsy demonstrated the progressive nature of the fibrosis in case n(o) 2. Magnetic resonance imaging, performed in 3 of the 4 cases, demonstrated deep penetration of the vascular proliferation. The lesions were in contact with bony structures in case n(o) 2, reached the hypodermis in case n(o) 3 and infiltrated between the adducter muscles in case n(o) 4.

DISCUSSION

Among tufted angiomas, there is a clinical variant characterized by very early discovery (congenital or within the first months of life), preferential localization on the lower limbs and progression to sclerosis. Although non-specific, hypersudation and lanuginous hypertrichosis are also highly suggestive signs. The main clinical and histological differential diagnosis is angio-eccrine hamartoma and, to a lesser degree, Kaposi hemangioendothelioma which does not predominate on the lower limbs. This particular clinical presentation of tufted angioma should lead to wide and sufficiently deep biopsy to allow precise diagnosis prior to initiating therapy. The possibility of spontaneous involution would allow abstention with regular surveillance to detect reactivation and progression or functional impairment. Such unfavorable progression has lead certain authors to propose high-dose systemic corticosteroid therapy or alpha-interferon.

[Sinusoidal hemangioma]

INTRODUCTION

Sinusoidal hemangioma (SH) was described by two pathologists, Calonje and Fletcher, in 1991. This uncommon cutaneous benign vascular lesions with distinctive histologic features was considered a subset of lesions known as "cavernous hemangiomas". It is made of dilated interconnecting ("sinusoidal"), thin-walled channels with a single-layered lining endothelium and a lobular architecture.

PATIENTS AND METHODS

Clinical, radiological (CT, MRI and arteriography), evolutive, and histologic data of 4 patients, whose lesions appeared very similar clinically and histologically, were reviewed and compared to the patterns of the so-called SH.

RESULTS

There were 2 males and 2 females. Lesions had an infantile onset in 3 (congenital in 2). They exhibited a protracted course over years in the 4, and they all invaded the right forehead, eyelids and orbit areas. Clinically, they appeared as multilobulated, building, firm tumors under a normal shiny skin. Radiologically, lesions were strikingly nodular, with criteria of slow-flow vascular lesions on MRI and arteriograms. Histologically, all lesions were comprised of well-circumscribed nodules with a lobulated architecture, made of greatly dilated, blood-filled, thin-walled vascular channels, with scanty fibrous stroma between them. Interconnecting channels had the distinctive sinusoidal pattern. There were some elongated pseudopapillary structures. Islands of spindle cells were noted in 2 lesions.

DISCUSSION

On the one hand histologic features of the lesions in our 4 patients are identical to those described by Calonje and Fletcher as SH, a lesion not to be confused with classic, involuting-type, hemangioma of infancy and childhood, and with venous or lymphatic malformations of the same location. SH fits into the group of lesions defined by pathologists as "cavenous hemangiomas". On the other hand the lesions in our 4 patients differed from the clinical description of SH as a solitary acquired small (less than 3 cm) nodule in adults. Otherwise the four lesions described herein constitute a distinctive clinicopathologic entity with a striking aggressive local growth although there is a histologic malformative pattern. The presence in 2 cases of islands of spindle cells led us to discuss the differences with spindle cell hemangioendothelioma.

Primary T-cell non-Hodgkin lymphoma of the larynx with subsequent cutaneous involvement

BACKGROUND

T lymphocytes expressing the gammadelta T-cell receptor represent a minority of normal T lymphocytes and are mostly located in the spleen or mucosa. Lymphomas expressing the gammadelta T-cell receptor are rare and usually present as hepatosplenic (negative for Epstein-Barr virus) disease. Primary lymphomas of the larynx are also rare.

OBJECTIVE

To report the first case of primary laryngeal gammadelta T-cell lymphoma related to Epstein-Barr virus infection.

DESIGN

Single-case study, including clinical, histological, immunohistochemical, and ultrastructural analysis, and in situ hybridization for Epstein-Barr virus-encoded small nuclear RNA.

PATIENT

An 88-year-old man presenting with a 6-month history of a cough followed by progressive dysphonia and a thickening of the left aspect of the aryepiglottic fold.

INTERVENTION

Two weeks of treatment with corticosteroids and antibiotics, followed by radiotherapy and then chemotherapy with chlorambucil and corticosteroids.

OUTCOME

The patient died of heart failure 10 months after the onset of the disease.

RESULTS

The tumor was laryngeal and disseminated to the skin over the parotid gland. Tumor cells were medium-sized T cells of cytotoxic immunophenotype, expressed the gammadelta T-cell receptor, and contained azurophilic granules and cytotoxiclike granules detected on electron microscopy. Epstein-Barr virus-encoded small nuclear RNA was detected in most tumor cells.

CONCLUSIONS

Lymphomas with a T-cell cytotoxic phenotype expressing the gammadelta T-cell receptor are rare, and this case appears to be the first to involve the larynx. The association between Epstein-Barr virus and T-cell lymphomas has been shown to be frequent in the upper respiratory tract and is confirmed in this case. This finding suggests that T cells in the upper respiratory tract may be more exposed to Epstein-Barr virus infections, perhaps because of their anatomical location.

[Maffucci syndrome: a false venous malformation? A case with hemangioendothelioma with fusiform cells]

BACKGROUND

Maffucci syndrome occurs as a sporadic disease. Progressive onset of both cutaneous vascular lesions (considered to be of venous type) and bony enchondromatous tumors (similar to those seen in Ollier disease) occurs throughout childhood. We report a case of a woman with Maffucci syndrome whose cutaneous vascular lesions revealed spindle cell hemangioendothelioma.

CASE REPORT

An italian woman developed severe bone distortion and dwarfism due to multiple enchondromas, first diagnosed as Ollier disease during childhood. At puberty, multiple vascular nodules appeared mainly on the limbs, leading to the diagnosis of Maffucci syndrome. Clinical data suggested the diagnosis of cutaneous venous anomalies: blue color of some nodules, phleboliths, arteriographic pattern. Histopathological examination of the skin specimen showed features of spindle cell hemangioendothelioma, e.g. nodules of dense spindle cell infiltration in combination with dysplastic vessels.

DISCUSSION

The few reports available do not clearly evidence the underlying histopathology progression of the lesions over years in a given patient. Skin lesions are classified among venous malformations. Bony enchondromatous involvement of the limbs is common and reported in 9 out of 10 patients. Both vascular and bony lesions classically develop from childhood to adulthood. Spindle cell hemangioendothelioma is a vascular tumor recently described. Cellular spindling in association with vascular spaces must not be misdiagnosed as Kaposi sarcoma. Some of the reported cases of spindle cell hemangioendothelioma had Maffucci syndrome. It is unknown whether Maffucci syndrome occurs in association with venous malformation or whether it is always present in the cutaneous vascular lesions of the disease.

Expression of the Emx-1 and Dlx-1 homeobox genes define three molecularly distinct domains in the telencephalon of mouse, chick, turtle and frog embryos: implications for the evolution of telencephalic subdivisions in amniotes

Homologies between vertebrate forebrain subdivisions are still uncertain. In particular the identification of homologs of the mammalian neocortex or the dorsal ventricular ridge (DVR) of birds and reptiles is still a matter of dispute. To get insight about the organization of the primordia of the main telencephalic subdivisions along the anteroposterior axis of the neural tube, a fate map of the dorsal prosencephalon was obtained in avian chimeras at the 8- to 9-somite stage. At this stage, the primordia of the pallium, DVR and striatum were located on the dorsal aspect of the prosencephalon and ordered caudorostrally along the longitudinal axis of the brain. Expression of homeobox-containing genes of the Emx, Dlx and Pax families were used as markers of anteroposterior developmental subdivisions of the forebrain in mouse, chick, turtle and frog. Their expression domains delineated three main telencephalic subdivisions in all species at the onset of neurogenesis: the pallial, intermediate and striatal neuroepithelial domains. The fate of the intermediate subdivisions diverged, however, between species at later stages of development. Homologies between forebrain subdivisions are proposed based on the conservation and divergence of these gene expression patterns.

[Importance of bFGF ("basic fibroblast growth factor") for diagnosis and treatment of hemangiomas]

OBJECTIVES

Hemangiomas of infancy follow a characteristic three-phases course: proliferation, involution, regressed Proliferative endothelial cells predominate during the proliferative phase. Moreover it has been shown that patients with active angiogenesis have elevated levels of urinary bFGF (basic Fibroblast Growth Factor).

PATIENTS AND METHODS

Here we report our preliminary results of urinary bFGF assay (ELISA) for the diagnosis and follow up of severe hemangioma. We also assayed bFGF in normal infants, in patients with large vascular malformations and in infants with Kasabach-Merritt syndrome.

RESULTS

In the control group, urinary bFGF was elevated in new borns but nul or very low in infants. Urinary bFGF levels were normal, i.e. very low in 4 patients with a vascular malformation. In infants with a clinically proliferative hemangioma, urinary bFGF was elevated in 8 among the 10 studied. bFGF levels guided treatment in 9 patients. Urinary bFGF was elevated in 4 patients with Kasabach-Merritt syndrome.

DISCUSSION

Angiogenesis is regulated by angiogenic and inhibitory factors. The angiogenic factor bFGF is an autocrine growth factor for endothelial cells and hemangioma endothelial cells expressing bFGF in their cytosol during the proliferative phase. As suggested by J. Folkman and his group, assay of urinary bFGF appears useful in differentiating between hemangioma and vascular malformation and for follow up of treated patients.