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S Louryan

Publications and source records attributed to S Louryan.

At least 19 recordsLinked to original sources
PubMed2006

Multimodal visualization interface for data management, self-learning and data presentation.

A multimodal visualization software, called the Data Manager (DM), has been developed to increase interdisciplinary communication around the topic of visualization and modeling of various aspects of the human anatomy. Numerous tools used in Radiology are integrated in the interface that runs on standard personal computers. The available tools, combined to hierarchical data management and custom layouts, allow analyzing of medical imaging data using advanced features outside radiological premises (for example, for patient review, conference presentation or tutorial preparation). The system is free, and based on an open-source software development architecture, and therefore updates of the system for custom applications are possible.

Anatomy↗
PubMed2006

Correlation of Hsp110 expression with caspase-3 and -9 during apoptosis induced by in vivo embryonic exposition to retinoic acid or irradiation in early mouse craniofacial development.

OBJECTIVE: To analyze the expression and role of three proteins (HSP110, caspase-3 and caspase-9) during craniofacial development. DESIGN: Seven pregnant C57Bl/6J mice received, by force-feeding at gestation day 9 (E9), 80 mg/kg of all-trans retinoic acid mixed to sesame oil. Seven pregnant NMRI mice received two grays irradiation at the same gestation day. Control mice of both strains (seven mice for each strain) were not submitted to any treatment. Embryos were obtained at various stages after exposition (3, 6, 12 and 24 h), fixed, dehydrated and embedded. Coronal sections (5 microm) were made. Slide staining occurred alternatively using anti-Hsp110, anti-caspase-3 and anti-caspase-9 immunohistochemistry. RESULTS: Expression of HSP110, caspase-3 and caspase-9 was found in cells of well-known locations of programmed cell death. After retinoic acid exposure, expressions were increased especially in neural crest cells of mandibular and hyoid arches. Quantification of positive cells shows that caspase-9 and Hsp110 were expressed before caspase-3. After irradiation, the expression of the three proteins quickly increased with a maximum 3 h after irradiation. For all three models of apoptosis (physiological, retinoic-induced and irradiation-induced) HSP110 positive cells were more numerous than caspase-3 positive cells. Caspase-3 positive cells were more numerous than caspase-9 positive cells especially in mesectodermal irradiation-induced apoptotic cells. CONCLUSION: The findings show a potential function of HSP110 in apoptosis during embryo development. Caspase-3-expressing cells are more numerous than cells expressing caspase-9, especially irradiation-induced apoptotic neural crest cells. This suggests that other caspases, still to be identified, may activate caspase-3 in this model.

Abnormalities, Drug-Induced↗
PubMed2005

A case with undescended testis, left pelvic kidney and gut malrotation.

We describe here an autopsy case presenting bilateral cryptorchidism, left pelvic kidney and intestinal malrotation, evoking a "reverse rotation" with hypoplasia of the cecum. Furthermore, the colon showed alternate bands of stenosis and dilatation. This association has not yet been described, and is discussed in the light of the embryological events of kidney, gut and gonad development. Two hypotheses can explain gut stenoses (vascular consequences of the malrotation and type Hirschprung aganglionic segments).

Aged↗
PubMed2005

[Expression of caspase 3 and p53 during physiological apoptosis and apoptosis induced by three teratologic agents during early craniofacial development of the mouse embryo].

The neural crest-derived mesectoderm gives rise to physiologic apoptosis areas in early vertebrate embryos. Certain teratologic agents increase this phenomenon. The purpose of this work was to detect caspase 3 (which is associated with the apoptosis cascade) and p53 in cell death areas, both during physiological apoptosis and during apoptosis induced by three agents (retinoic acid, methyl-triazene, irradiation). Antibody revelation was performed using the aBC peroxidase kit. Quantifications were also performed on histological sections. We observed caspase 3 uptake on some apoptotic and preapoptotic cells in control embryos, and in the embryos exposed to the three teratogens. Immunoreactivity generally preceded the development of cytological features of apoptosis. However, p53 was expressed only in the embryos exposed to ionizing radiation and methyl-triazene (an alkylating agent), but not significantly in embryos exposed to retinoic acid. The present results throw some light on apoptosis mechanisms in several teratologic conditions.

Animals↗
PubMed2004

[Histologic and ultrastructural features of cell death both physiological and induced by two different teratogens in branchial arches of mouse embryo].

AIM OF THE STUDY: To observe and compare cell death process both physiological and associated with the administration of two different teratogens (irradiation and retinoic acid) inside cephalic mesectoderm. MATERIAL AND METHODS: Irradiated mice: 2 Gy were administered to E 9 embryos. Retinoic acid: 60 mg/kg were gave to E 8 or E 9 embryos. E 9 - 9.5 and E 10 embryos were removed. E 9 - E 9.5 and E 10 control specimens were collected. We used semi-thin sections and ultra-thin sections observed with transmission electron microscope. RESULTS: The major process is apoptosis, which is increased in experimental embryos compared to control specimens. However, autophagy was observed in retinoic acid-treated embryos, while necrosis can rarely occurs after irradiation. CONCLUSION: If the common process seems to be apoptosis, both teratological models differs owing to their respective secondary features. These differences should be explained by the specific pathogenesis of both teratological agents: ligand-receptor reaction and Hox system disruption in retinoic acid administration, direct aggression against DNA and diffuse cell death process following irradiation. Furthermore, congenital malformations induced by these teratogens are quite different. This can be partially explained by a specific blow of different cellular subpopulations.

Animals↗
PubMed2004

[External auditory meatus adenocarcinoma].

We report the case of a man presenting a deafness and a hemorrhagic ear discharge since one year. CT scanner and MRI reveal an invasive tumoral lesion of the external auditory meatus (EAM) expending into the posterior fossa. After surgery the diagnosis of high grade ceruminal gland adenocarcinoma is established whereas the malignancy was not obvious on earlier biopsy. Cancers arising in the EAM are uncommon and are essentially representating by squamous cell cancers and basal cell cancers. The precise diagnosis of a glandular tumor is a challenge for the pathologist because the limits between benign and malignant tumors are not obvious. Integration of clinical and radiological behavior and the histology of the tumor is necessary for a early diagnosis and a complete surgery.

Adenocarcinoma↗
PubMed2004

[Oral verrucous carcinoma].

Verrucous carcinoma is a rare, low-grade, well-differentiated form of squamous cell carcinoma seen on skin and mucosa. It is a slow-growing and locally aggressive tumor whose standard treatment is surgery. A case of strongly invasive oral verrucous carcinoma is presented with the medical history. The differential diagnosis of this neoplasm is difficult and requires clinic and pathologic data confrontation. In this paper, the importance of knowing the malignant potential of this lesion is stressed. Indeed, in 20% of verrucous carcinoma, foci of squamous cell carcinoma can be found. A review of literature and a differential diagnosis of verrucous carcinoma are presented.

Biopsy↗
PubMed2004

[Combined middle and inner ear abnormality: report of a case].

Congenital anomalies of the middle ear associated to anomalies of the inner ear are rarely described. Our case displays a malformation due to an association of congenital absence of the round window and aplasia of the semi-circular canals, causing conductive hearing loss. First diagnosis was a congenital atresia isolated of the round window, related to a previous surgical exploration. We tried a novel technique designed to restore the function of the round window. Labyrinthine anomalies prevented a good outcome. This kind of malformative association could be due to the complexity of early genetic control of ear development. Attentive analysis of imaging should be performed before middle ear surgery to determine the presence of inner ear anomalies which are quite frequent and which would limit its usefulness.

Abnormalities, Multiple↗
PubMed2003

Ectopic stapes: a case report with embryologic correlations.

A case report of unilateral congenital stapes misplacement revealed by computed tomography is presented. In addition to this malformation, the malleus was synostosed to the middle ear roof. This kind of stapes ectopia has not been described previously. We have analyzed the malformative pattern in the light of normal and teratologic development of the stapes. In a teratologic model in which retinoic acid is administered to pregnant mice, we have observed an ectopic stapes primordium independent of the otic capsule. We discuss the possible pathogenesis of this abnormality in terms of the genetic events of middle ear development, which can be perturbed by retinoic acid administration.

Adult↗
PubMed2003

Differential expression of S100 calcium-binding proteins in epidermoid cysts, branchial cysts, craniopharyngiomas and cholesteatomas.

AIMS: To investigate whether epidermoid cysts, branchial cysts, craniopharyngiomas and cholesteatomas express S100 proteins differentially by immunohistochemical assaying the presence of S100A1, S100A2, S100A3, S100A4, S100A5, S100A6 and S100B. METHODS AND RESULTS: Immunopositivity/negativity was recorded for each S100 protein in a series of 52 cases consisting of 12 epidermoid cysts, 12 branchial cysts, 15 adamantinomatous craniopharyngiomas and 13 acquired cholesteatomas. Except in the case of the craniopharyngiomas, immunoreactivity was assessed independently in the basal membrane and the basal, the internal and the keratin layers. Our data show that in contrast to S100B, which was rarely expressed, S100A1, S100A2, S100A4 and S100A5 were often present in these four types of epithelial lesions. S100A3 and S100A6 and, to a lesser extent, S100A5 were the most differentially expressed proteins across the different histopathological groups analysed. These three proteins are expressed more often in craniopharyngiomas and cholesteatomas, the two more aggressive types of lesions. CONCLUSIONS: This is the first study to report data on the expression of seven S100 proteins in different histopathological groups of epithelial head and neck lesions, whose precise embryological origins are still a matter of debate. S100 proteins could possibly be used as markers to target this embryonic origin, since our results show that S100A3 and S100A6 (and, to a lesser extent, S100A5) are expressed differentially across these different groups of epithelial lesions.

Adolescent↗
PubMed2002

Computed tomography of a cyclotocephalic neonate.

Cyclotocephaly is a very rare malformative lethal condition which associates otocephaly (extreme hypoplasia of the mandibular arch with agnathia) and cyclopy with proboscis. The head of a cyclotocephalic neonate from our Museum of Anatomy and Embryology was examined using computed tomography (CT). Cutaneous and osseous three-dimensional reformations were performed. Severe bony malformations were observed. A single orbital cavity was surrounded by a cartilaginous proboscis and a median fusion of maxillae, temporal and zygomatic bones. The single orbital cavity contained both paramedial eyeballs (synophthalmia). The external auditory meati and the ear pinnae were also parasagittal. No oral cavity and mandible were observed. Despite the poor conservation state of the brain, lobar holoprosencephaly was suspected. The mesencephalon and pituitary gland were absent. This exercise could lead to optimizing ultrasonographic prenatal diagnosis.

Abnormalities, Severe Teratoid↗
PubMed2002

[Diagnostic imaging of peripheral vertigo].

Clinical imaging investigation of vertigo is actually mainly performed using MRI, which offers a detailed analysis of cochieo-vestibular nerve and labyrinth. Computed tomography is reserved to the analysis of bony structures. Several causes of vertigo are described, e.g. tumours, labyrinthitis, malformations, Ménière's disease, otoscierosis, trauma, cholesteatomas and postoperative changes. The interest of imaging is discussed. The necessity to perform paraclinical tests prior to diagnostic imaging to optimise the choice of imaging is emphasized.

Cochlea↗
PubMed2002

[Heat shock proteins, embryogenesis and evolution].

We present results about immunohistochemical identification of several heat shock proteins (HSP'S) during mouse normal and teratological embryogenesis. Apoptotic cells express very specifically and precociously HSP 110. This fact permits to identify apoptotic cells before apparition of morphologic features of apoptosis, but also to quantify the process of cell death in some teratological models, particularly administration of retinoic acid. HSP 86 is expressed in some cell populations, and particularly permanent in germ cells. Our observations brought us to discuss the potential protective role of HSP on germ cells, and the consequence of their inactivation in the macroevolution process, as well as the role of apoptosis in teratology.

Animals↗