Differential responses of olfactory neurons to axotomy at embryonic and postnatal stages.

In the nervous system, apoptosis is a major process during embryonic and postnatal stages. In chick, experimental cell death can be obtained by axotomy. We have compared the responses of olfactory neurons to axotomy at embryonic stage E17 and postnatal stages.Forty-three chicken embryos and 32 young chickens less than 3 weeks old were used. We combined optic microscopy, electronic microscopy, terminal (TdT)-mediated dUTP-nick end labeling (TUNEL) method and gel electrophoresis of genomic DNA to analyze cell death. Cells in synthetic phase were labeled by bromodeoxyuridine injected i.p. and detected by immunohistochemistry. Apoptotic index and 5-bromo-2'-deoxyuridine (BrdU) labeling index were calculated for each stage. The Wilcoxon test was used for statistical analysis. A P value <0.05 was considered significant. Within 3 days following axotomy in E17 chicken embryos, there was no significant increase of apoptosis on the lesion side analyzed 3, 6, 12, 18, 24, 48 or 56 h later. A slight increase of bromodeoxyuridine incorporation appeared at 3 h, was weakly significant at 24 h (P=0.045) and the return to basal rate took place at 48 h. In postnatal stages, an apoptotic wave appeared 12 h after axotomy, reached a maximum at 24 h, and then decreased between 48 h and 72 h. A significant elevation of bromodeoxyuridine incorporation occurred on 48 h with a 24 h delay after the peak of apoptotic death. This differential response to axotomy in embryos and postnatal chickens might be due to a less complete maturation and higher plasticity of embryonic olfactory neurons corresponding to different requirement for survival and differentiation factors. Thus the embryonic or immature neurons would depend more on local epithelial environment and mature or postnatal neurons would require target-derived survival factors and die from apoptosis after their shortage resulting from axotomy.

[Elastofibroma in the scapular region. A case report and review of the literature]. / Elastofibrome de l'espace scapulo thoracique. Revue de la littérature à propos d'un cas.

PURPOSE OF THE STUDY: We report a case of elastofibroma and have collected 280 cases in the literature. MATERIAL AND METHODS: A 56 year-old man presented with a right subscapular mass. The patient was asymptomatic but he reported a "clicking"sensation associated with mobilization of the shoulder. Physical examination revealed a round mass clearly demonstrated with forward elevation of the arm. The MRI scan showed a heterogeneous soft tissue composed of inhomogeneous density with areas of more intense signal suggesting adipose tissue. The tumor was surgically excised and the diagnosis of elastofibroma was established by histopathologic examination. RESULTS: Six months after removal of the mass, there were no functional complications. DISCUSSION: Elastofibromas usually occur in active patients generally older than 55 years of age. They are typically located in the right subscapular region. The tumor remains asymptomatic in more than 50 percent of cases. 25 percent of the patients may report a simple discomfort sometimes with a "clicking" or "catching" sensation associated with mobilization of the arm. Pain is present in less than 10 percent of cases. Physical examination may reveal a rubbery, asymptomatic mass located in the subscapular region and barely noticable when the arm lies again the chest. Plain radiographs and preoperative laboratory data were unremarkable. CT scan or MRI scan may show an heterogeneous fibrous mass of intermediate density with entrapped signals of higher intensity. However, a definitive diagnosis requires a biopsy showing the distinctive feature of elastofibroma: elastic fibers in a collagenized fibrous tissue with entrapped adipose tissue. Pathogenesis of elastofibromas may result from the friction of the scapula against the thorax thus generating tumor growth. CONCLUSION: Complete surgical excision in symptomatic patients is considered to be the treatment of choice. However, once the diagnosis of elastofibroma has been established, excision of lesions smaller than 5 cm can be avoided in asymptomatic patients.

Monoclonal antibodies to Hammondia hammondi allowing immunological differentiation from Toxoplasma gondii.

Five murine monoclonal antibodies (MAbs) were developed against purified sporozoites of Hammondia hammondi. Despite a large antigenic similarity between the 2 closely related coccidia, H. hammondi and Toxoplasma gondii, these MAbs only reacted with H. hammondi. Three MAbs, ID3, 3F2, and 4C9-7, recognized antigens of 38 kDa localized in rhoptries (1D3), in rhoptries and in oocyst and cyst walls (3F2), and in rhoptries and the apical region (4C9-7). Another MAb, 4C9-10, reacted with a 27-kDa antigen in dense granules of sporozoites and tachyzoites, and MAB 11B3 labeled an antigen of >94 kDa located in the pellicular membrane of the 3 stages of the parasite. These MAbs could be used for a rapid discrimination of the 2 coccidia in epidemiological studies or for diagnostic purposes in tissues.

Cytokeratins expression in paragangliomas of the cauda equina.

BACKGROUND: Paragangliomas rarely involve the cauda equina region. In this location, these tumors can show misleading morphological features such as trabecular or papillary growth patterns and variable expression of cytokeratins. METHODS: We comparatively studied the immunohistochemical and ultrastructural patterns of 3 paragangliomas of the cauda equina (PCE) and of 8 paragangliomas from other sites. RESULTS: All the paragangliomas expressed neuroendocrine markers (neuron-specific enolase, chromogranin A, synaptophysin and neurofilament protein). In PCE, chief cells exhibited a strong positivity with a broad spectrum anti-cytokeratin antibody. The staining was diffuse in the cytoplasm or had a paranuclear dot-like disposition. In other sites, only one paraganglioma showed a focal expression of cytokeratins. At ultrastructural level, chief cells of PCE contained characteristic dense core granules and intermediate-sized filaments sometimes grouped in paranuclear whorls. CONCLUSION: The dual immunophenotype of PCE, paraganglionic and epithelial, must be recognized in order to distinguish these tumors from, for example, a metastasis of a neuroendocrine carcinoma. PCE are slow-growing tumors and have mostly a favorable prognosis after complete surgical excision.

Treatment of the postenucleation socket syndrome with a new hydroxyapatite tricalcium phosphate ceramic implant.

PURPOSE: Surgical correction of the postenucleation socket syndrome (PESS) is challenging. Various biomaterials are used for reconstruction of the anophthalmic orbit, often with unsatisfactory long-term results. Implants have been placed between the periorbital and the orbital floor. The authors describe a new material composed of hydroxyapatite tricalcium phosphate (HA-TCP) in the form of ceramic blocks, to be placed into the orbital fat as a new surgical site. METHODS: Ten patients with PESS underwent surgery to compensate the volume deficit of the anophthalmic orbit. Blocks of HA-TCP were created by fragmentation of a larger piece, tailored as needed, and implanted in the orbital fat. The patients were monitored regularly with clinical and radiologic examinations to evaluate the behavior of the implants. RESULTS: The volume of the HA-TCP was measured in 5 cases (mean, 2.95 +/- 1.08 ml). A significant reduction of enophthalmos was obtained: mean Hertel exophthalmometry measured 12.7 +/- 2.5 mm preoperatively and 14 +/- 2.4 mm postoperatively (p < 0.05). The average prosthesis volume was significantly reduced in the cases measured: 2.7 ml +/- 0.94 ml preoperatively and 1.8 +/- 0.7 ml postoperatively (p < 0.02). There was a negative correlation between the HA-TCP implant volume and postoperative prosthesis volume (correlation coefficient = -0.925; p < 0.05). According to photographic evaluation, correction of the enophthalmos and of the superior sulcus depression were obtained in 70% and 90% of cases, respectively. Magnetic resonance imaging seems to demonstrate that the blocks become well integrated into the surrounding orbital tissue. CONCLUSION: The HA-TCP blocks correct some anomalies of PESS. Placement of the blocks directly into the orbital fat is a promising alternative to the traditional subperiosteal location.

Hammondia hammondi organelle proteins are recognized by monoclonal antibodies directed against organelles of Toxoplasma gondii.

Hammondia hammondi and Toxoplasma gondii, 2 closely related coccidia of cats, are known to share many antigenic molecules as shown by serologic cross reactivity. Monoclonal antibodies (MAbs) directed against the internal organelles of Toxoplasma gondii were tested by immunofluorescence assay and immunoelectron microscopy on the tachyzoites of H. hammondi. The MAbs anti-apex, anti-dense granules, anti-micronemes, and anti-rhoptries recognized, although weakly, the corresponding antigens on H. hammondi. This finding demonstrates that organelles of the 2 parasites are not only morphologically, but also antigenically, similar.

Treatment of experimental osteosarcoma tumors in rat by herpes simplex thymidine kinase gene transfer and ganciclovir.

Previous results have demonstrated the efficiency of Herpes simplex type 1 thymidine kinase (HSV1-TK) retroviral gene transfer and ganciclovir (GCV) treatment of a human osteosarcoma cell line resulting in the death of the cell population and a proximal bystander effect; therefore, we investigated gene therapy on an in vivo osteosarcoma rat model. For in vivo experiments, small fragments of tumor were grafted onto rats in a paratibial position. Seven days after the graft, packaging cells (psi CRIP-TK and psi CRIP-LLZ) were inoculated into tumor mass, followed by GCV administration. In vivo results showed the efficiency of this system that allowed the reduction of the tumor mass and prevented lung metastasis appearance, which represents the normal evolution. This type of treatment seems promising for rapidly proliferating tumors such as osteosarcoma; the lower IC50 makes this system particularly attractive as clinically doses may be of low magnitude to prevent secondary effects in patients.

Interactions of hydroxyapatite and fluorapatite particles on human osteoarthritis type B synoviocytes: effects on interleukin-1 alpha levels and lipoxygenase pathways.

We investigated the effects of the biomaterials hydroxyapatite (HAP) and fluorapatite (FAP) on cultured human osteoarthritis type B synoviocytes by analyzing interleukin-1 alpha (IL-1 alpha) production and arachidonic acid metabolism via lipoxygenase pathways. A portion of opsonized particles was endocytosed and was found in numerous phagolysosomes in human synoviocyte cytoplasms. The present study demonstrates that HAP and FAP calcined at 700 degrees C induced a decrease in IL-1 alpha production but markedly decreased the synthesis of lipoxygenase products after 1-month incubation with the particles. This model will allow us to study the possible inflammatory response (arachidonic acid metabolism, proinflammatory cytokines) that can be induced by any biomaterials used in orthopedics.

Binding of autoantibodies is not restricted to desmosomes in pemphigus vulgaris: comparison of 14 cases of pemphigus vulgaris and 10 cases of pemphigus foliaceus studied by western immunoblot and immunoelectron microscopy.

Pemphigus vulgaris (PV) and pemphigus foliaceus (PF) are autoimmune blistering diseases characterized by a loss of cell-cell adhesion and by autoantibodies directed against epidermal cadherins. PF antigen has been established as desmoglein I which is located strictly on the desmosome, whereas the precise ultrastructural localization of PV antigen remains unclear and controversial to date. To further investigate this question, we compared the location of immune deposits in 14 patients with PV and 10 patients with PF by both direct and indirect immunoelectron microscopy (IEM). Inclusion criteria were based upon clinical features, histological level of cleavage and characterization of circulating antibodies by Western blot on epithelial bovine tongue extracts. IEM was performed on unfixed 0.7-mm slices of skin for the direct technique or on normal skin for the indirect technique using peroxidase labelling. In PF, by both direct and indirect IEM, immune deposits were located on the extracellular part of desmosomes (desmoglea) in all the samples studied. In PV, by both direct and indirect IEM, deposits were situated on the desmoglea and along large portions of the keratinocyte membrane without desmosomal structures in 15 of the 18 samples studied and only on the desmoglea in 3 samples. These results suggest that, in contrast to PF, the target antigen in PV is not always restricted to desmosomes. As various types of adherens junctions have been reported to mediate cell adhesion in the epidermis, the PV antigen could be a component of desmosomes and of other focal adhesions.

[Multicentric histiocytosis with hematological involvement]. / Histiocytose multicentrique avec atteinte hématologique.

INTRODUCTION: The aim of this work was to present a case of multicentric histiocytosis with haematologic involvement. CASE REPORT: A 68-year-old man presented with poor general health and a nodular eruption of the skin and larynx. On clinical examination there was an enlarged spleen and laboratory results revealed an inflammatory syndrome, platelet count 60,000 and myelemia with 10 p. 100 immature elements in a white cell count of 14,000. Pathology and ultrastructure examinations led to the diagnosis of multicentric histiocytosis. Bone marrow aspiration was normal. Pancytopenia then developed with bone marrow hypoplasia without infiltration. Corticosteroids then cyclophosphamide were uneffective for either the skin disease or the hematologic disorder. The patient developed severe buccal aphthosis which responded well to thalidomide. This treatment reduced the size and the number of skin nodules. Finally, renal failure of unknown origin was observed. DISCUSSION: Electron microscopy is essential for positive and differential diagnosis of atypical multicentric histiocytosis. Hematological disorders associated with multicentric histiocytosis may either be specific or totally independent.

Hammondia hammondi cysts in cell cultures.

In an attempt to obtain the continuous development of Hammondia hammondi in vitro, culture of the parasite was performed in 3 cell lines. Although organisms were present in culture fluids of feline kidney cells (CRFK) for as long as 3 mo, continuous culture was not possible. However, for the first time, cysts of H. hammondi were observed in cell culture from day 6 after inoculation of sporozoites. Ultrastructure of the H. hammondi cysts was similar to that observed for in vitro-obtained Toxoplasma gondii cysts. Feeding a cat with these in vitro-developed cysts resulted in oocyst shedding 5 days after ingestion.

A plant steroid, diosgenin, a new megakaryocytic differentiation inducer of HEL cells.

We investigated the effect of plant steroids 5 alpha-spirosten-3 beta-ol (diosgenin), 5 alpha-spirostan-3 beta-ol (tigogenin) and 5 alpha-spirostan-3 beta-ol-12-one (hecogenin) on the human erythroleukemia cell line (HEL TIB 180) and found that diosgenin addition to HEL cell cultures induces morphological and biochemical changes characteristic for megakaryocyte cells. Diosgenin-treated cells exhibit, at the ultrastructural level, increases in size in cytoplasmic and nuclear complexity. At the biochemical level, we demonstrated that diosgenin-treated HEL cells increased glycoprotein Ib (GpIb) expression as previously described in the megakaryocytic differentiation of HEL cells induced by nanomolar dose phorbol myristate acetate treatment.

[Inguinal mastocytosis with histiocytic infiltrate]. / Mastocytose inguinale avec infiltrat histiocytaire.

INTRODUCTION: The diagnosis of mastocytosis is usually not difficult in cases with typical skin lesions. Intertrigo is exceptional. CASE REPORT: An 83-year-old patient developed inguinal intertrigo bilaterally. The lesions contained maculopapulous elements without Darier's sign. The histology examination revealed a mixed mast cell infiltration predominated by histiocytes. The ultrastructure confirmed the diagnosis of cutaneous mastocytosis. No extension was observed. DISCUSSION: Skin folds are rarely involved in infiltrating diffuse mastocytosis. Two cases have been reported in the literature including one doubtful case. Mastocytosis should thus be included in the possible diagnoses in patients with macupopapulous intertrigo. In addition, the mastocytic and histiocytic polymorphism observed here is rare.

Widenings of the myelin lamellae in a typical Guillain-Barré syndrome.

The so-called "widening of the myelin lamellae" are thought to be specific ultrastructural features of peripheral nerve myelin in patients with peripheral neuropathy associated with a monoclonal dysglobulinemia of IgM type and antiglycolipid activity. We report here a case of Guillain-Barré syndrome with no evidence of serum monoclonal dysglobulinemia, presenting the typical widenings of the myelin lamellae in small-diameter myelinated fibers from a sural nerve biopsy. In view of the positive reaction with anti-C3d complement on direct immunofluorescence, an immunological mechanism may be involved in the widenings of the myelin lamellae.

[Epidermoid carcinoma arising in femoral osteitis. A case]. / Carcinome épidermoïde sur ostéite du fémur: un cas.

The authors report a case of malignant degeneration arising from a fistula in a patient with chronic osteomyelitis of the femur. This rare complication (0.2 per cent-1.6 per cent) most frequently involves the lower limb. A review of the literature reveals that it is associated with long-standing osteomyelitis (30 years), is most frequently a squamous cell carcinoma or rarely a sarcoma, and is principally treated by surgical amputation. The frequency of metastatic spread is low (30 per cent). Malignant degeneration appears to be a local phenomenon, and if diagnosed early, has a rather favorable outcome following complete excision.

[Clear cell tumor of the lung (sugar tumour). Study of a case]. / Tumeur à cellules claires du poumon ("sugar tumour"). Etude d'un cas.

A case of benign clear cell tumor ("sugar tumor") is reported. Light microscopy showed a proliferation of clear cells with a rich blood supply and endocrinoid pattern. Ultrastructurally, cells were loaded with glycogen both free and membrane-bound. The cellular origin of the benign clear cell tumor of the lung is still uncertain.

Peripheral and central distal axonopathy of suspected inherited origin in Birman cats.

Three female cats, littermates born from clinically normal parents, were examined at 8 to 10 weeks of age because of a slowly progressive posterior ataxia. Another cat from a previous litter from the same parents suffered from similar neurological symptoms. Histopathological examination of the nervous tissues of these animals revealed degeneration of axons and myelinopathy in a distal distribution pattern. Both peripheral nerves and central nervous system were involved. The central nervous system lesions were most prominent in the lateral pyramidal tracts of the spinal cord, the fasciculi gracili of the dorsal column in the cervical spinal cord and the cerebellar vermian white matter. In the PNS numerous degenerating nerve fibers were found in the sciatic nerves but not in the spinal nerve roots. Our findings show that these cats were suffering from a hereditary multisystem degeneration with a distribution pattern of the lesions suggestive of a distal axonopathy.