Dielectric relaxation of normothermic and hypothermic rat corneas.

This paper aims at the presentation of the results of in vitro research on the dielectric properties of the cornea specimen collected from the rats subjected to in vivo hypothermia. The average values of the relative permittivity and dielectric loss are about 40% higher for the hypothermic cornea than those for the normothermic tissue at the same water content of 12% for both samples and at 25°C. Whereas, at 50°C this effect of increase in the dielectric properties of the hypothermic cornea when compared to the normothermic one is observed clearly only in the relative permittivity of about 19%. In the temperature range of 25-50°C, the activation energy of conductivity associated with the release of loosely bound water takes the average values of 45kJ/mol and 30kJ/mol for the normothermic and hypothermic corneas, respectively. The study provided information on dielectric polarization and conductance mechanisms in the cornea which may be helpful in interpreting clinical results of human cornea examination, currently obtained by means of such electrodiagnostic methods as conductive keratoplasty, electroretinography or electrooculography.

Dielectric phenomena associated with the keratin-glucose interactions of nail plate.

In this study, we analyzed the effect of water and frequency on the dielectric properties of the nail plate in healthy individuals and in diabetic patients. The temperature dependencies of the loss tangent for both healthy and diabetic nail represent the relation between the electrical energy lost and stored in keratin-glucose-water complexes of this tissue. The differences between these materials concern the temperature ranges in which there appears the decomposition of loosely bound water. The effect of glycation on the loss tangent of the wet and the dry nail is supported by higher values of this parameter than in those describing the healthy samples in the whole temperature range and above 100°C, respectively. In addition, glycation lead to distinct increase in the dielectric relaxation decrement in permittivity and dielectric loss between the frequency of 500 Hz and 100 kHz for the wet and the dry nail. The results of this study indicate that the dielectric spectroscopy may be useful in observing the decomposition of water in the diabetic nail plate.

[Nasal dermoïd cyst with intracranial extension: which approach?]. / Kyste dermoïde nasal avec extension intracrânienne: quelle voie d'abord?

Dermoïd cyst is the most common midline congenital nasal tumor. Intracranial extension is rare but possible, must be suspected and confirmed by a cerebral magnetic resonance imagining (MRI). Only total surgical removal via a combined intracranial/extracranial approach appears to provide a complete resolution and effective protection against late recurrence. We report a case of a 2 years old patient who was operated for a nasal congenital cyst extending to the nasal septum. Anatomopathology showed a dermoïd cyst. Five years later, he presented local recurrence of the dermoïd cyst with intracranial extension through a bifid crista galli. We conclude that to avoid recurrence, the removal of the nasal cyst and sinus tract must be followed to its dural attachment. A transfacial approach can be associated with frontal craniotomy, which can provide adequate exposure for complete removal of the intracranial component of the cyst and sinus tract. A literature review was performed.

Epidural hematoma revealed by exophthalmia, two cases reports.

Epidural or extradural hematoma is a well known entity, usually a complication of severe traumatic head injury. The clinical presentation is most commonly a decline in consciousness and new neurological deficits. Fewer than 20% of patients demonstrate the classic presentation of a lucid interval between the initial trauma and subsequent neurological deterioration. The association of an epidural hematoma with a subperiostal intraorbital hematoma is rare, where exophthalmia is the only presenting sign. We report on two cases of frontal epidural hematoma revealed by an exophthalmia after a minor head trauma. On reporting our cases we aim to increase the awareness of this association each time a head or facial trauma is associated with exophthalmia.

[Choroid plexus carcinoma: a case report]. / Carcinome du plexus choroïde : à propos d'un cas.

OBJECTIVE: Choroid plexus carcinomas are rare and occur more frequently in children than in adults. The differential diagnosis includes choroid plexus papilloma and papillary ependymoma. The prognosis is generally poor. The objective of this paper is to discuss the epidemiological characteristics, diagnosis, treatment, and prognosis of this rare childhood tumor. CASE REPORT: A three-year-old child was hospitalized with a history of partial epilepsy and intracranial hypertension. A computed tomography scan showed an intracranial mass measuring 11cm in diameter, extending to the ventricle system with heterogeneous contrast enhancement. He was urgently operated for loss of consciousness. During the operation, the patient developed an abundant hemorrhage and died. The histopathological examination of the excised tumor identified a choroid plexus carcinoma. CONCLUSION: Choroid plexus carcinomas are rare and treatment is currently controversial. Radical excision is quite difficult and associated with excessive blood loss.

Unusual brain edema caused by an intracranial hydatid cyst: c ase report and literature review.

The differential diagnosis of intracranial brain cystic lesions, including malignant lesions, abscesses and cystic astrocytoma, can sometimes be difficult even when using a sophisticated imaging technique. This is particularly evident in certain rare lesions such as hydatid cysts. In fact, any imaging modality that can make the diagnosis can optimize conservative or surgical treatment and prevent unnecessary biopsy. A case of a six-year-old male with raised intracranial tension and rapid consciousness disturbance presumably caused by a left frontal hydatid cyst, surrounded by an unusual edema is reported. We concluded that intracranial hydatid cyst should be entertained whenever a cystic lesion is found in an endemic region.

[Extra dural arachnoid cyst: case report]. / Kyste arachnoïdien extradural spinal: à propos d'un cas.

Extradural arachnoid cysts are uncommon expanding lesions in the spinal canal, which may communicate with the subarachnoid space. Usually located in the lower thoracic spine, they may cause symptoms by compressing the spinal cord or nerve roots. We report a case of an extradural thoracic arachnoid cyst revealed by progressive spinal cord compression. CT myelography and MRI enabled diagnosis. Rapid neurological improvement was observed after surgical resection.

[Multilevel costovertebral echinococcosis: effectiveness of a combined approach]. / Hydatidose costovertébrale pluriétagée: intérêt d'un abord combiné.

Hydatid disease generally involves the liver and the lung, but rarely can be encountered in bones. The disease predominantly occurs in vascularized areas, involving in descending order: vertebrae, long bones, ilium, skull, and ribs. Vertebral and rib hydatidosis may result from vascular or lymphatic migration of a fertile cell from a hepatic focus. In humans, the two main forms are due to Echinococcus granulosis and less frequently, E. multilocularis (alveolaris). The hydatid cysts usually grow slowly asymptomatically and compression of the involved or the neighboring organ causes clinical manifestations. In this patient, hydatid disease occurred in the chest wall with secondary spinal canal involvement successfully treated by removal of cysts via T7, T8, T9, T10, and T11 laminectomies via a posterior approach, followed by resection of the involved ribs. Total removal of cysts without rupture appears to provide effective protection against late recurrences.

Primary vertebral echinococcosis: four cases reports and review of literature.

Primary vertebral echinococcosis has been considered to be a hypothetical and exceptional possibility. It affects bones in 1% of reported cases. Spine is involved in 45-50% of these. The disease preferentially affects the thoracic spine. It begins as a single primary cyst containing daughter cysts. We report four cases of primary vertebral echinococcosis, extending into the extradural space without any other primary site of infection. We conclude that primary vertebral echinococcosis, although rare should be considered in destructive lesions of the vertebrae and spine in regions that the disease is endemic. Advanced imaging studies should be performed to diagnose the disease. Early decompressive surgery of the spine, with chemotherapy, is the treatment of choice for these patients.

[Spontaneous otogenic pneumocephalus]. / Pneumocéphalie spontanée otogénique .

Otogenic pneumocephalus is uncommon. Typical causes include trauma, tumor, infection, and nasosinusal or mastoid surgery but spontaneous otogenic pneumocephalus is very exceptional. We report a case of spontaneous otogenic pneumocephalus located in the left temporal lobe revealed by sudden onset aphasia. The temporal pneumatocele was cured through an epidural subtemporal approach with needle puncture of the aeroma and duroplasty. Two years after surgery, no recurrence was observed and the patient remained symptom free.

[Ectopic prolactinoma of the sphenoidal sinus: case report]. / Prolactinome ectopique du sinus sphénoïdal.

A 34-year-old woman was hospitalized for exploration of amenorrhea and galactorrhea. She had experienced primary sterility, diagnosed 11 years earlier. Endocrine tests demonstrated hyperprolactinemia (serum prolactin 594 ng/ml). Magnetic resonance imaging (MRI) showed a soft tissue mass located within the posterior part of the sphenoidal sinus. The pituitary gland appeared normal. Medical treatment with bromocriptine was unsuccessful. Transsphenoidal tumor resection was performed. Histology reported adenoma, which was consistent with prolactin-producing tumor demonstrated by immunohistochemical staining for prolactin. Because of the persistence of hyperprolactinemia related to an intra-sphenoidal tumor remnant, bromocriptine (15 mg/d) was initiated. Menses ensued and prolactin level declined (49 ng/ml). One year later, the tumor remnant had disappeared on the MRI and the patient became pregnant. Ectopic adenomas of the sphenoidal sinus are of particular interest due to the diagnostic difficulties encountered. Nevertheless, the nature of the lesion can be determined from the endocrine manifestations. Some of these tumors respond to medical treatment, similar to intra sellar tumors. Surgery remains however the only means of obtaining definitive diagnosis and cure.

Cavernous sinus tuberculoma: diagnostic difficulties in a personal case.

BACKGROUND: Tuberculoma of the brain is rare, and its location in the cavernous sinus is exceptional. Many factors make the diagnosis difficult, necessitating a surgical procedure. CASE DESCRIPTION: A 44-year-old woman complained of persistent headaches and diplopia. The examination revealed a right cavernous sinus syndrome. Radiologic investigation showed a growing process in the right cavernous sinus, overlapping the sella turcica. The diagnoses of metastasis, tuberculoma, and sarcoidosis were considered, but none of them could be confirmed. A biopsy of the lesion via a subtemporal approach revealed a tuberculoma. Antituberculous treatment led to complete resolution of her symptoms. CONCLUSION: The diagnosis of a cavernous sinus tuberculoma is difficult; it is confirmed by biopsy. However, a trial of medical treatment, if the results are favorable, may obviate the need for a surgical procedure.

Comparative analysis of reproductive cycles in female Persian gazelle (Gazella subgutturosa subgutturosa) (Central Asia) and sand gazelle (Gazella subgutturosa marica) (Arabian Peninsula).

This study was conducted at the Bukhara breeding centre (Ouzbekistan, Central Asia) on Persian gazelles (Gazella subgutturosa subgutturosa) and at Thumammah (Saudi Arabia) on sand gazelles (Gazella subgutturosa marica). Plasma prolactin (PRL) and progesterone were determined in groups of females. Because these females were under two different photoperiods (20 degrees N in Saudi Arabia and 40 degrees N in Uzbekistan), some Persian females were treated with melatonin implants. Both groups of females living in natural environment in Uzbekistan and in Saudi Arabia exhibited an estrus (autumn and early winter) and an anestrus season (spring and summer). Both groups of females exhibited estrous and anestrous seasons. The estrous season was shorter in females from Uzbekistan. During the anestrous season, progesterone concentrations remained at basal levels in Persian gazelles (Uzbekistan) while in sand gazelles (Saudi Arabia) hormonal concentrations were higher than in Persian gazelles until August and decreased to similar concentrations in September-October. Moreover, the pattern of PRL significantly differed in the two groups. Persian gazelles exhibited a clear seasonal pattern with significantly high levels of PRL in June whereas in the sand gazelle PRL did not rise significantly in summer and fluctuated widely. Melatonin treatment significantly depressed PRL concentrations but did not affect the length of the estrous season in Persian gazelles, suggesting that the reproductive cycle was entrained by an endogenous rhythm.