Longitudinal comparison of two severities of unilateral cervical spinal cord injury using magnetic resonance imaging in rats

Magnetic resonance imaging (MRI) should be a powerful tool for characterization of spinal cord pathology in animal models. We evaluated the utility of medium-field MRI for the longitudinal assessment of progression of spinal cord injury (SCI) in a rat model. Thirteen adult rats were subjected to a 6.25 or 25 g-cm unilateral cervical SCI, and underwent MRI and behavioral tests during a 3-week study period. MRI was also performed post-mortem. Quantification of cord swelling, hypointense and hyperintense signal, and lesion length were the most valuable parameters to determine and were highly correlated to behavioral and histopathological measures. Immediately after injury, MRI showed loss of gray matter-white matter differentiation, presence of scattered hyperintense signal and local hypointense signal, and cord swelling in both groups. At 7 days after injury, the spinal cord in the 25 g-cm group was significantly larger than that of the 6.25 g-cm group (p = 0.02). Contrast enhancement of the lesion was seen at 24 h in the 6.25 g-cm group, and at 24 h and 7 days in the 25 g-cm group. The volume of hypointense signal, representing hemorrhage, throughout the lesion region was significantly larger in the 25 g-cm compared to the 6.25 g-cm group at both 14 and 21 days after SCI (p, 相似文献   

Profile of endothelial dysfunction in arterial hypertension. Vascular ultrasound assessment

Assessment of endothelial dysfunction in arterial hypertension using brachial ultrasound is a common method. Because of prognostic value of flow mediated dilation, vascular ultrasound is considered the standard noninvasive method. MATERIAL AND METHOD: In our study we assessed 92 hypertensive patients (very carefully selected) in a prospective and long term follow-up manner. We used the technical indications of actual guidelines. RESULTS: We confirmed the importance of a complete and complex assessment of endothelial dysfunction, using different parameters. Our study demonstrated that endothelial dysfunction exists in hypertensives, has a large interindividual variability and can be improved using adequate treatment. We also proposed a new parameter--the velocity ratio, and tested the value of normalized diameter ratio, as a nonconventional variable.     

Bioluminescence monitoring of intracranial glioblastoma xenograft: response to primary and salvage temozolomide therapy

OBJECT: Bioluminescence imaging (BLI) offers a rapid and accurate means for longitudinal study of tumor cell growth and response to therapy in rodent models. Because this technology has only recently come into use in the field of small animal imaging, applications in this area have been limited. In the current study we have applied BLI to the analysis of clinically relevant issues involving use of the DNA methylating agent temozolomide (TMZ) in a mouse model. METHODS: An invasive glioblastoma multiforme xenograft was modified for BLI via transduction with a luciferase-encoding lentivirus. Supratentorial tumors were established in athymic nude mice that were subsequently assigned randomly to control and TMZ treatment groups, and the extent of intracranial tumor was monitored using BLI. RESULTS: In an experiment designed to compare the extent of antitumor effect between a single high-dose TMZ treatment and a protracted low-dose TMZ regimen, BLI revealed the protracted regimen as having superior antitumor effect, and this interpretation was consistent with results from a survival comparison between the two TMZ treatment groups. In a second experiment designed to assess the utility of BLI for testing therapies against recurrent glioblastoma multiforme, mice with intracranial tumors were retreated with TMZ at a time when BLI monitoring revealed tumor regrowth following initial TMZ treatment, and retreatment was successful in providing additional survival benefit. CONCLUSIONS: The results of these experiments indicate that BLI monitoring can be used as a surrogate for predicting survival benefit from TMZ treatment, permits early determination of relative survival benefit associated with distinct TMZ therapeutic regimens, and offers a means of investigating secondary/salvage therapy efficacy following tumor regrowth from initial therapy.     

Untersuchungen über die Funktion des reticuloendothelialen Systems bei experimenteller Streptokokkensepsis

Ohne ZusammenfassungMit 10 Abbildungen im Text.