DTI-MRI at 2 days after spinal cord injury accurately predicts long-term locomotor function recovery in rats.

OBJECTIVE: Spinal cord injury (SCI) damages an individual's sensory, motor, and autonomic functions and represents a social emergency, mostly in developed countries. Accurate and timely diagnosis of the severity of SCI must be carried out as quickly as possible to allow time for drug and therapy testing in the early stages after injury. MATERIALS AND METHODS: Male Dark Agouti (DA) rats underwent spinal cord cryoinjury at the T13 level of the spine. Under typical conditions, in vivo magnetic resonance imaging (MRI) T2 and echo-planar imaging - diffusion tensor imaging (EPI-DTI) examinations were conducted. This involved the reconstruction of nerve tracts and the measurement of the fractional anisotropy (FA) index, as well as measurements of the ratio of Hyper/Hypo intensive areas and spinal cord injury severity scores. RESULTS: Our study shows that, after cryoinjury, the FA significantly decreased in all animals. An increase in FA level, derived from EPI-DTI within 2 days after SCI, accurately predicts long-term locomotor function recovery. In rats with higher FA, recorded on day 2 after injury, complete restoration of locomotor function was observed, while at low FA values, the animals maintained stable monoplegia. CONCLUSIONS: Our results, though validating the T2 10-grade MRI scale for SCI, indicate that FA would represent the MRI technical instrument, which would better monitor the evolution of SCI and, accordingly, better objectively evaluate the impact of potentially therapeutic protocols for spinal cord traumatic injury. Despite the results achieved, significant difficulties must be overcome on the way to successful clinical implementation of the findings in humans.

CSF - injected contrast medium enhances post-traumatic spinal cord cysts. An experimental study in rats.

OBJECTIVE: Spinal cord injury (SCI) is still one of the most challenging problems in neurosurgical practice. One of the major obstacles to neural regeneration following trauma is the formation of glial scarring and post-traumatic cysts which acts against proper growth of axons through the site of injury. Cerebrospinal fluid (CSF) delivery of bioactive agents into cystic cavities could represent a promising therapeutic strategy. In the present study, we investigated specifically the dynamics of intradural delivery of contrast medium and its relocation into post-traumatic cysts in an experimental model of spinal cord cryoinjury in rats. MATERIALS AND METHODS: 32 male Sprague Dawley SPF rats were submitted to injury as previously described. Omnipaque-240 was injected either into the cisterna magna or at the level of the cauda equina. Subsequently, cerebral CT scan examinations were performed in order to check the CSF dynamics of the contrast medium. RESULTS: There was a steady accumulation of contrast medium into post-traumatic cysts as early as five minutes after injection. A dosage of 65 mg of iodine per kilogram ensured an adequate feeling of the cysts at an average of 30 minutes. CONCLUSIONS: Our data indicate that intraspinal injection of bioactive agents can easily reach the site of injury and fill post-traumatic cysts. This could represent an interesting potential therapeutic protocol for SCI.

A new mouse unilateral model of diffuse alveolar damage of the lung.

OBJECTIVE AND DESIGN: The existing biological models of diffuse alveolar damage (DAD) in mice have many shortcomings. To offset these shortcomings, we have proposed a simple, nonsurgical, and reproducible method of unilateral total damage of the left lung in ICR mice. This model is based on the intrabronchial administration of a mixture of bacterial lipopolysaccharide (LPS) from the cell wall of S. enterica and α-galactosylceramide (inducing substances) to the left lung. METHODS: Using computer tomography of the lungs with endobronchial administration of contrast material, we have been able to perform an operative intravital verification of the targeted delivery of the inducer. The model presented is characterized by more serious and homogeneous damage of the affected lung compared to the existing models of focal pneumonia; at the same time, our model is characterized by longer animal survival since the right lung remains intact. RESULTS: The model is also characterized by diffuse alveolar damage of the left lung, animal survival of 100%, abrupt increases in plasma levels of TNFa, INFg, and IL-6, and significant myocardial overload in the right heart. It can be used to assess the efficacy of innovative drugs for the treatment of DAD and ARDS as the clinical manifestations that are developed in patients infected with SARS-CoV-2. Morphological patterns of lungs in the noninfectious ("sterile") model of DAD induced by LPS simultaneously with α-galactosylceramide (presented here) and in the infectious model of DAD induced by SARS-CoV-2 have been compared. CONCLUSION: The DAD model we have proposed can be widely used for studying the efficacy of candidate molecules for the treatment of infectious respiratory diseases, such as viral pneumonias of different etiology, including SARS-CoV-2.

In Vitro Biodegradation of Resorbable Magnesium Alloys Promising for Implant Development.

The aim of the investigation was to study the biodegradation characteristics and rate of magnesium alloys in vitro. MATERIALS AND METHODS: We studied the biodegradation of magnesium alloys Mg-Zn-Ca and WE43 (Mg-Y-Nd-Zr) in homogenized (initial) condition and after strengthening by mechanical processing using equal channel angular pressing (ECAP). The samples were incubated in a model system based on reference fetal calf serum (FCS) in the static and dynamic modes. The morphology of alloy surfaces was analyzed using light microscopy and computed tomography. Biodegradation was assessed by calculating weight loss within a certain incubation period. Cell adhesion and colonization stimulation were quantified in terms of a cell index (CI) using an analyzer xCELLigence RTCA Systems (ACEA Biosciences, Inc., USA) during the incubation of HEK 293 cells on WE43 specimens. RESULTS: Strengthening of magnesium alloys Mg-Zn-Ca and WE43 using ECAP and, consequently, the changed structure resulted in the biodegradation acceleration as high as eightfold. Among the specimens incubated in FCS in different modes, those incubated in liquid flow exhibited the biodegradation rate twice as high as that of the specimens tested under static conditions. The biodegradation process was accompanied by local corrosion, although the degradation was primarily concentrated along the specimen margins stimulating cell adhesion and colonization. Such nature of degradation, as a rule, does not lead to anisotropy of the strength characteristics, that is important for medical materials. Superficial degradation of the alloys with no X-ray density changes in the bulk of the specimens was confirmed by computed tomography. CONCLUSION: The study of the biodegradation rate and further characteristics of magnesium alloys Mg-Zn-Ca and WE43 showed that the materials in both structural conditions are suitable for implants and can be used in bone implants and surgical fasteners.

[Effectiveness of various combinations of chemoradiotherapy for children and adolescents with Hodgkin's disease].

The paper presents the results of a retrospective analysis of the chemoradiotherapy of 393 infant patients with Hodgkin's disease.

[Efficacy of remote gamma-therapy in patients with juvenile angiofibroma of the base of the skull].

The results of radiation therapy of 48 patients with juvenile nasopharyngeal angiofibroma were analysed. It was found that radiation therapy can produce 80% stable remissions in postoperative recurrence or unresectable tumor. The response did not depend on primary size of the tumor and was better in a total dose over 35 Gy and in children over 14 years of age. Long-term side effects were minimal and did not deteriorate quality of life.

[Efficiency of radiation or chemoradiation therapy for diffusely growing brainstem tumors in children].

Radiation or chemoradiation therapy was performed in 97 children with diffusely growing brainstem tumors. A reduction in the severity of neurological disorders was achieved in 92 (94.8%) patients. The course of the disease was traced in 79 patients. Control studies recorded no complete tumor regression. Following 4-8 months, there was growth resumption of a tumor with its lysis and cyst formation in most children. The principal cause of death was local tumor progression. Six-month survivors were 64 (81%) patients; one-, two-, and three-survivors were 21 (26.5%), 8 (10.1%), and 3 (7.65) patients, respectively; one (2.8%) patient survived 5 years. A combination of radiotherapy and monochemotherapy with temodal, vincristine, oncofer, and theraloc failed to improve immediate and long-term results