Growth and setting of gas bubbles in a viscoelastic matrix imaged by X-ray microtomography: the evolution of cellular structures in fermenting wheat flour dough.

X-ray tomography is a relevant technique for the dynamic follow-up of gas bubbles in an opaque viscoelastic matrix, especially using image analysis. It has been applied here to pieces of fermenting wheat flour dough of various compositions, at two different voxel sizes (15 and 5 µm). The resulting evolution of the main cellular features shows that the creation of cellular structures follows two regimes that are defined by a characteristic time of connectivity, tc [30 and 80 min]: first (t ≤ tc), bubbles grow freely and then (t ≥ tc) they become connected since the percolation of the gas phase is limited by liquid films. During the first regime, bubbles can be tracked and the local strain rate can be measured. Its values (10(-4)-5 × 10(-4) s(-1)) are in agreement with those computed from dough viscosity and internal gas pressure, both of which depend on the composition. For higher porosity, P = 0.64 in our case, and thus occurring in the second regime, different cellular structures are obtained and XRT images show deformed gas cells that display complex shapes. The comparison of these images with confocal laser scanning microscopy images suggests the presence of liquid films that separate these cells. The dough can therefore be seen as a three-phase medium: viscoelastic matrix/gas cell/liquid phase. The contributions of the different levels of matter organization can be integrated by defining a capillary number (C = 0.1-1) that makes it possible to predict the macroscopic dough behavior.

[Intracranial ependymomas in adult patients. Diagnosis and histological prognostic factors]. / Ependymomes intracrâniens de l'adulte. Diagnostic histologique et facteurs histopronostiques.

BACKGROUND: Intracranial ependymomas are rare in adults and histopathological prognostic factors are poorly determined. PURPOSE: A retrospective multicentric study was conducted in France in order to assess the prognostic value of histology. MATERIAL: Between 1990 and 2004, 216 adult patients with newly diagnosed ependymomas were treated in 19 French centers. Eligibility required institutional histopathological confirmation of an ependymoma and available clinical history and MRI features (see comparison paper). METHODS: Histological preparations and one paraffin embedded block from each patient were sent to Pr D. Figarella-Branger in Marseille. Central review by four neuropathologists (D. Figarella-Branger, A. Maues de Paula, C. Fernandez and A. Jouvet) was performed. Specimens for which all pathologists agreed with the histological diagnosis of ependymomas were included, whereas cases for which all disagree were excluded and reclassified. In the event of doubt and/or discrepancies between pathologists immunostaining was performed in order to reach a consensus diagnosis. Diagnostic of ependymomas was confirmed in 121 cases (56%). In theses cases, ependymomas were classified according to the WHO system (subtype and grade). The potential prognostic value (overall survival OS and disease free survival DFS) of the following histological parameters was examined: perivascular pseudorosettes, ependymal rosettes, hyalinized vessels, mitotic index, microvascular proliferation, necrosis, area of increased cellularity, nuclear atypia, brain invasion and Mib-1 labelling index. RESULTS: Among the 121 ependymomas, 88 were grade II (47 classic, 17 cellular, 2 papillar, 6 clear cells and 16 tanicytic) and 33 grade III. WHO grading, occurrence of microvascular proliferation, necrosis, nuclear atypia and high proliferative index were correlated with both OS and DFS. Moreover, quantification of certain parameters enabled a reproducible grading system correlated with both OS and DFS.

[Ultrastructural study of epiretinal membrane stained by trypan blue: 15 case reports]. / Etude ultrastructurale des membranes épirétiniennes idiopathiques colorées au bleu trypan.

INTRODUCTION: Idiopathic epiretinal membrane results from detachment of the posterior hyaloid and is believed to be related to naturally occurring defects in the internal limiting membrane (ILM) of the retina. Vitrectomy and peeling are the treatment of choice. Trypan blue 0.15% (TB) stains epiretinal membrane and internal limiting membrane. It allows selective and complete removal, facilitating surgery, with less retinal damage. An ultrastructural study was conducted showing ultrastructural features of idiopathic epiretinal membranes (ERM) and those of the internal limiting membrane and its connections with the retinal side. MATERIAL AND METHODS: After pars plana vitrectomy and induction of posterior vitreous detachment, 0.2 ml TB 0.15% was injected over the ERM in an air-filled eye. The stained tissue was peeled with intraocular forceps. Specimens were at once collected in 4% glutaraldehyde for a transmission electron microscopy study. RESULTS: TB may allow complete and easier ERM and ILM peeling. The staining does not present toxic effects. The major cellular contingent is represented by glial cells, participating actively in neocollagen synthesis. Their presence supports the hypothesis of a migratory movement of retinal cells toward the vitreoretinal side. CONCLUSION: The presence of an intact internal limiting membrane, the absence of optical fibers belonging to the under retina, and the absence of any sign of apoptosis make TB a useful staining agent for ERM and ILM peeling.

Cadmium-containing granules in kidney tissue of the Atlantic white-sided dolphin (Lagenorhyncus acutus) off the Faroe Islands.

Top predators from the northern sub-polar and polar areas exhibit high cadmium concentrations in their tissues. In the aim to reveal possible adverse effects, samples of five Atlantic white-sided dolphins Lagenorhyncus acutus have been collected on the occasion of the drive fishery in the Faroe Islands, for ultrastructural investigations and energy dispersive X-ray microanalyses. Cadmium concentrations were less than the limit of detection in both immature individuals and ranged from 22.7 to 31.1 microg x g(-1) wet weight in the mature individuals. Two individuals with the highest cadmium concentrations exhibited electron dense mineral concretions in the basal membranes of the proximal tubules. They are spherocrystals made up of numerous strata mineral deposit of calcium and phosphorus together with cadmium. Cadmium has been detected with a molar ratio of Ca:Cd of 10:1 in the middle of these concretions. To our knowledge, this is the first report of such granules in a wild vertebrate. The role of these granules in the detoxification of the metal and the possible pathological effects are considered.

[Primary thyroid lymphoma: report of 8 cases]. / Lymphome malin primitif de la thyroïde: à propos de huit cas.

PURPOSE: Primary thyroid lymphoma (PTL) is a rare disease. Few patients are reported in the literature. We report eight new cases of PTL with long-term follow-up. RESULTS: The clinical presentation was usually an enlarging neck mass squeezing surrounding structures. The diagnosis was established after thyroidectomy with histopathologic and immunohistochemical studies. Histology showed infiltrates of chronic lymphocytic thyroiditis in all cases. Three patients had thyroid lymphoma arising from mucosa-associated lymphoid tissue. One patient died postoperatively. The other seven were treated with combined chemotherapy and radiotherapy. They were still in remission after a 6-year follow-up. CONCLUSION: Diagnosis of PTL should be suspected when there is a recent thyroid enlargement. Surgery associated with chemotherapy and radiation gave good results in our study with long-term follow-up, though surgery was not always recommended in previous reports.

Retinol binding protein in rainbow trout: molecular properties and mRNA expression in tissues.

Retinoids are important regulatory signaling molecules during embryonic development. The molecular properties of rainbow trout (Oncorhynchus mykiss) retinol-binding protein (rtRBP), the specific retinol carrier in vertebrate plasma, were studied to elucidate its role in transporting retinols to developing fish oocytes. A 954-nucleotide rtRBP cDNA was cloned from the liver coding for a 176-amino-acid (aa) mature protein, with an estimated molecular mass of 20,267 Da. The nucleotide sequence suggests a putative 16-aa signal peptide and shows all the aa residues that were previously identified as critical for the retinol binding pocket. Five of the eight amino acid residues that are associated with the interaction of RBP and transthyretin in mammalian and non-mammalian species are conserved. The deduced aa sequence of rtRBP shows 60-66% identity with zebrafish, chicken, mouse, rat, horse, bovine, and human RBPs and 56% identity with Xenopus RBP. Northern blot analysis revealed a approximately 1.1-kb hepatic mRNA transcript. RBP is highly expressed in the liver, but low levels were also detected in the spleen, kidney, ovary, and brain. In the rainbow trout, 17beta-estradiol treatment led to a decrease in the RBP mRNA signal relative to that of the controls. The efficacy of the 17beta-estradiol treatment was verified by an induction of vitellogenin (VTG) mRNA expression in the liver and occurrence of VTG in the plasma.

[Mixed type amyloidomas, beta2 microglobulin and AL lambda, in a long term hemodialysis patient]. / Amyloïdomes fessiers de type mixte, beta 2-microglobuline et AL lambda, chez une patiente hémodialysée au long cours.

A frequent complication of hemodialysis is deposition of beta 2-microglobulin amyloid in tendons and joints. Soft tissues involvement is exceptional. A 74 year-old woman on hemodialysis for 21 years developed two bilateral and symmetric tumours in gluteal regions causing discomfort when sitting. Histology, immunohistochemistry and electron microscopy showed that deposit consisted of predominant beta 2-microglobulin and lambda light chain. This is an unusual localisation of amyloidosis developing late in the course of hemodialysis. It may be perhaps initiated by chronic traumatism and be promoted by the light chain lambda of immunoglobulin.

[Pigmented Paget's disease of the male nipple]. / Maladie de Paget pigmentée du mamelon chez l'homme.

BACKGROUND: Mammary Paget's disease unfrequently occurs in males, and may be pigmented in rare instances. Differential diagnosis with malignant melanoma relies on immunohistochemical studies. CASE REPORT: A case of Paget's disease of the nipple in a 76 year-old male is reported, clinically mimicking a malignant melanoma because of massive pigmentation. Histologically, large Paget's clear cells were intermingled with numerous melanin-rich dendritic melanocytes. An underlying ductal carcinoma was found. After differential immunohistochemical staining, diagnosis of Paget's disease could be unequivocally substantiated since Paget's cells stained for epithelial markers, c-erbB-2 and hormonal receptors, whereas protein S100 and HMB45 were negative. DISCUSSION: Pigmentation in mammary Paget's disease occurs preferentially in males. Pigmentation results from numerous melanocytes with abundant melanin in close contact with Paget's cells. An increased number of melanocytes may also be observed in cutaneous metastatic breast carcinomas. It could result from a chemotactic factor produced by neoplastic cells.

Molecular characterization and high expression during oocyte development of a shrimp ovarian cortical rod protein homologous to insect intestinal peritrophins.

Penaeoid shrimp oocytes nearing the completion of oogenesis are enveloped in an acellular vitelline envelope and possess extracellular cortical rods (CRs) that extended into the cortical cytoplasm. These cortical specializations are precursors of the jelly layer (JL) of the egg. In searching for highly expressed mRNAs during oogenesis in the marine shrimp (Penaeus semisulcatus), two related cDNAs have been isolated that encode a mature protein of 250 amino acid residues. The deduced amino acid sequences revealed the presence of repeated cysteine-rich domains that are related to the chitin-binding domains of insect intestinal peritrophins. Similar cysteine-rich domains were reported in insect intestinal mucin, crustacean tachycitin, and invertebrate chitinases. The shrimp ovarian peritrophin (SOP) is glycosylated and can bind chitin when extracted from CRs. Its apparent molecular mass in SDS-PAGE is 29-35 kDa and 33-36 kDa, under nonreducing or reducing conditions, respectively. SOP is a major protein of CRs and the JL, and was immunodetected in ovaries; purified CRs; fertilized eggs that were surrounded by a JL matrix; and in the cloudy, whitish flocculent material appearing in sea water immediately after spawning. Immunolocalization in tissue sections determined that SOP was present in oocyte cytoplasm and in extraoocytic CRs. Shrimp expressed SOP mRNA in ovaries at all oocyte developmental stages, whereas expression in the hepatopancreas was restricted to vitellogenic stages. SOP mRNA was abundant in the shrimp ovary and was detected before the presence of the corresponding protein. This is the first demonstration that a protein with similar features to insect intestinal peritrophins is a component of CRs and is therefore a main precursor of the JL of spawned shrimp eggs.

Ultrastructural study of rat hippocampus after chronic administration of aluminum L-glutamate: an acceleration of the aging process.

An ultrastructural study of rat hippocampus was performed on young (group 1) and old (group 4) rats receiving daily subcutaneous injections of aluminum L-glutamate and on old untreated rats (group 5). Young controls were treated with sodium L-glutamate (group 2) and physiological saline (group 3). Group 1 showed vacuolated astrocytes with numerous lipofuscin deposits, mitochondrial swelling, a thinning of the myelin sheath, and many multivesicular bodies invading the cytoplasm. Cellular structure did not appear to be affected in groups 2 and 3. Group 4 showed swollen mitochondria, a demyelination process in axonal regions, sizable perivascular oedema with vessel retraction and gliofilament bundles. In this group, lipofuscin deposits in astrocytes were associated with multivesicular bodies that thinned the myelin sheath to the breaking point; however, no excitotoxic glutamate-induced effects were observed. In group 5, extreme cytoplasmic vacuolation was observed, with massive mitochondrial swelling, considerable thinning of the myelin sheath (at times to the breaking point), sizable vacuolar degeneration and gliofilament bundles. These results indicate that ultrastructural alterations in the hippocampus, such as cell vacuolization, massive mitochondrial swelling and the demyelination process, occur with aging and independently of aluminum intoxication. Similar alterations were observed in aluminum L-glutamate-intoxicated young rats, but not in controls. These results are consistent with aluminum-induced acceleration of the aging process.

Molecular characterization and gene expression in the eye of the apolipophorin II/I precursor from Locusta migratoria.

The transport of lipids via the circulatory system of animals constitutes a vital function that uses highly specialized lipoprotein complexes. In insects, a single lipoprotein, lipophorin, serves as a reusable shuttle for the transport of lipids between tissues. We have found that the two nonexchangeable apolipoproteins of lipophorin arise from a common precursor protein, apolipophorin II/I (apoLp-II/I). To examine the mechanisms of transport of lipids and liposoluble substances inside the central nervous system, this report provides the molecular cloning of a cDNA encoding the locust apoLp-II/I. We have recently shown that this precursor protein belongs to a superfamily of large lipid transfer proteins (Babin et al. [1999] J. Mol. Evol. 49:150-160). We determined that, in addition to its expression in the fat body, the locust apoLp-II/I is also expressed in the brain. Part of the signal resulted from fat body tissue associated with the brain; however, apoLp-II/I was strongly expressed and the corresponding protein detected, in pigmented glial cells of the lamina underlying the locust retina and in cells or cellular processes interspersed in the basement membrane. The latter finding strongly suggests an implication of apolipophorins in the transport of retinoids and/or fatty acids to the insect retina.

Intestinal fatty acid binding protein gene expression reveals the cephalocaudal patterning during zebrafish gut morphogenesis.

Intracellular fatty acid-binding proteins (FABPs) are small and highly conserved cytoplasmic proteins that bind long-chain fatty acids and other hydrophobic ligands. We have examined, as a model for studying intestinal epithelial cell differentiation, the cell-specific and spatio-temporal expression of intestinal fatty acid-binding protein (i-fabp) gene during zebrafish larval development. After molecular cloning of zebrafish I-FABP cDNA, whole-mount in situ hybridization analysis revealed that i-fabp is expressed in the intestinal tube around day 3 postfertilization. By day 4, highest level of i-fabp transcript is encountered in the proximal columnar epithelium. From day 5 onwards, i-fabp is strongly expressed in the anterior intestine and its rostral expansion, slightly expressed in the esophagus mucosa and rectum, while no mRNA could be detected in the posterior intestine. Therefore, the regional differentiation of the intestine precedes first feeding and complete yolk resorption. I-fabp expression in the anterior intestine of the fed larvae is correlated with an intracellular storage of lipid droplets in the enterocytes and the massive synthesis of very low-density lipoprotein particles. In conclusion, the cephalocaudal expression pattern of i-fabp demarcates early during zebrafish gut morphogenesis the anterior fat absorbing to posterior cells of the intestine. This gene could be used as a marker for screening for mutations that affect the events of intestinal epithelial differentiation, cephalocaudal patterning, and asymmetric gut looping morphogenesis.

[Alveolar adenoma: a rare peripheral pulmonary tumor]. / L'adénome alvéolaire: une tumeur pulmonaire périphérique rare.

Alveolar adenoma was first described in 1986. It is a benign peripheral lung neoplasm present more frequently in middle-aged woman. We report a new case occurring in 52 year-old woman. We describe histopathological and immunohistochemical characteristics. Then, this observation is compared with the 11 cases previously published. Finally, we try to understand its origin.

Chronic administration of aluminium L-glutamate in young mature rats: effects on iron levels and lipid peroxidation in selected brain areas.

Clinical and experimental studies have demonstrated the neurotoxicity of aluminium (Al), notably as a result of lipid peroxidation in vitro. We previously showed that Al is able to cross the blood-brain barrier as an L-glutamate complex and be deposited in rat brain. The present work in young mature rats investigated the in vivo effects of chronic Al-L-glutamate treatment on Al and iron movement in plasma and selected brain regions. Brain lipid peroxidation was determined by evaluating the production of thiobarbituric acid reactive substances (TBARS) and analysing polyunsaturated fatty acids (PUFAs) such as C20:4n-6 and C22:6n-3. Our results indicate that iron concentration was decreased in plasma and that Al accumulated especially in striatum where iron levels were decreased and in the hippocampus where TBARS were increased without PUFA modifications. These data show that Al administered chronically as an L-glutamate complex is neurotoxic in vivo and thus provides a good model for studying Al toxic mechanisms.

High-dose chemotherapy with hematopoietic stem cell transplantation in adults with bone marrow relapse of medulloblastoma: report of two cases.

Extraneural relapses of medulloblastoma are associated with a very poor outcome. We present two cases of young adults who developed bone marrow metastases after treatment of medulloblastoma. A very good response to a sequentially scheduled combination of carboplatin and etoposide was observed. Then, high-dose chemotherapy was delivered consisting of busulfan and thiotepa followed by infusion of autologous hematopoietic stem cells. Toxicity of the conditioning regimen was acceptable. The patients remained free of disease 20 and 27 months from the time of relapse, respectively. Further studies are needed to evaluate the impact of high-dose chemotherapy in terms of survival of such patients.

[Multiple vulvar cystic and papillary fibroadenomas]. / Fibroadénomes vulvaires multiples, kystiques et papillaires.

We report a new case of multiple vulvar fibroadenoma arising in a 47-year-old woman. This papillary and cystic lesion shares similarities with papilliferum hidradenoma and mammary fibroadenomas. After describing clinical and pathological characteristics, we try to detail its origin according to the literature and particularly its relationship with anogenital sweat glands and ectopic mammary glands.

[Papillary fibroelastoma. A rare etiology of strokes in young patients]. / Fibroélastome papillaire. Une étiologie rare des accidents vasculaires cérébraux du sujet jeune.

BACKGROUND: The papillary fibroelastomas are cardiac lesions, which typically occur on the cardiac valves, but rarely on the endocardium. The incidence of these benign primitive tumors varies from 0.002 to 0.33% and increases with advancing age. METHODS: We report two cases of stroke, one in a 31-year-old man and the other in a 48-year-old woman, both admitted to the same stroke center. RESULTS: The diagnostic studies were normal in these two patients, except for the echocardiography. The first showed an echogenic mass on the mitral valve on transthoracic echocardiography (TTE), confirmed by the transesophageal echocardiography (TEE). The second demonstrated a mass on the sigmoid aortic valve on TEE, but the TTE was normal. For these two patients, a surgical excision was carried out and pathologic examination concluded to a papillary fibroelastoma. After surgery, no recurrence was observed. CONCLUSIONS: The papillary fibroelastomas are usually asymptomatic and easily detected by TEE. However, it can be revealed by stroke, myocardial infarction and lower limbs ischemia. These cardiac tumors should be surgically removed, since their complete excision remains the only means of avoiding a recurrence of embolism.

The naevoid basal-cell carcinoma syndrome (Gorlin syndrome) is a chromosomal instability syndrome.

The Gorlin syndrome, or naevoid basal-cell carcinoma syndrome (NBCS) is an autosomal dominant cancer prone disease (at risk of multiple basal cell carcinomas, and other malignant or benign proliferations). We have previously reported data from peripheral blood lymphocytes of patients with this condition, showing a significant level of spontaneous chromatid and chromosome rearrangements and an overall lengthening of the cell cycle. In this paper, we confirm this disease to be a chromosome instability syndrome from studies on fibroblasts of 5 patients. Spontaneous chromosomal rearrangements, an increased frequency of sister chromatid exchanges and a slowing of the cell cycle were found, compared to age-matched control material. There was also an increased sensitivity to aberration production by mechlorethamine in patient fibroblasts. The chromosome instability we found was not restricted to a given cell lineage, but appears to be part of the general condition of this syndrome. The recently discovered gene responsible for Gorlin syndrome, PTC (or PTCH), encodes a transmembrane protein with yet poorly known functions. However, the demonstration of Gorlin syndrome as a chromosome instability syndrome suggests that this protein has a role in DNA maintenance, repair and/or replication.

t(3;17)(q21;q25) in Epstein-Barr virus associated peripheral T-cell lymphoma: a paediatric case.

We describe an immunocompetent 8-year-old boy with a serological profile indicating chronic infection by Epstein-Barr virus (EBV) who developed subcutaneous and pulmonary lesions related to a peripheral T-cell proliferation. No clonal rearrangement of T-cell receptor or immunoglobulin genes was seen. However, the finding of a t(3;17)(q21;q25) in 44 metaphases from one skin lesion demonstrated a clonal origin. We also showed that the proliferative T cells contained EBV genome leading to the diagnosis of EBV-associated peripheral T-cell lymphoma. Further cytogenetic and molecular studies are needed to identify genes implicated in the pathogenesis of this haematological malignancy.