Eugene Vlodavsky

Hyperbaric oxygen therapy for reduction of secondary brain damage in head injury: an animal model of brain contusion.

Cerebral contusions are one the most frequent traumatic lesions and the most common indication for secondary surgical decompression. The purpose of this study was to investigate the physiology of perilesional secondary brain damage and evaluate the value of hyperbaric oxygen therapy (HBOT) in the treatment of these lesions. Five groups of five Sprague-Dawley rats each were submitted to dynamic cortical deformation (DCD) induced by negative pressure applied to the cortex. Cerebral lesions produced by DCD at the vacuum site proved to be reproducible. The study protocol entailed the following: (1) DCD alone, (2) DCD and HBOT, (3) DCD and post-operative hypoxia and HBOT, (4) DCD, post-operative hypoxia and HBOT, and (5) DCD and normobaric hyperoxia. Animals were sacrificed after 4 days. Histological sections showed localized gross tissue loss in the cortex at injury site, along with hemorrhage. In all cases, the severity of secondary brain damage was assessed by counting the number of terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) and caspase 3-positive cells in successive perilesional layers, each 0.5 mm thick. Perilesional TUNEL positive cells suggested the involvement of apoptosis in group 1 (12.24% of positive cells in layer 1). These findings were significantly enhanced by post-operative hypoxia (31.75%, p < 0.001). HBOT significantly reduced the severity and extent of secondary brain damage expressed by the number of TUNEL positive cells in each layer and the volume of the lesion (4.7% and 9% of TUNEL positive cells in layer 1 in groups 2 and 4 respectively, p < 0.0001 and p < 0.003). Normobaric hyperoxia also proved to be beneficial although in a lesser extent. This study demonstrates that the vacuum model of brain injury is a reproducible model of cerebral contusion. The current findings also suggest that HBOT may limit the growth of cerebral contusions and justify further experimental studies.

Neuroprotective effect of hyperbaric oxygen therapy in brain injury is mediated by preservation of mitochondrial membrane properties

Recent experimental data have shown that hyperbaric oxygen therapy (HBOT) was associated increased Bcl-2 expression at the injury site that correlated with reduced apoptosis. We hypothesized that HBOT mediated enhancement of Bcl-2 expression and increased intracellular oxygen bio-availability may both contribute to preserve mitochondrial integrity and reduce the activation of the mitochondrial pathway of apoptosis. For this purpose, a cortical lesion was created in the parietal cortex of Sprague-Dawley rats by dynamic cortical deformation (DCD) and outcome measures in non-treated animals were compared with that of HBOT treated rats. Morphological analysis showed a profound reduction in neuronal counts in the perilesional area and a marked rarefaction of the density of the axonal-dendritic network. In treated animals, however, there was a significant attenuation of the impact of DCD over perilesional neurons, characterized by significantly higher cell counts and denser axonal network. In mitochondria isolated from injured brain tissue, there was a profound loss of mitochondrial transmembrane potential (Deltapsi(M)) that proved to be substantially reversed by HBOT. This finding correlated with a significant reduction of caspases 3 and 9 activation in HBOT treated animals but not of caspase 8, indicating a selective effect over the intrinsic pathway of apoptosis. All together, our results indicate that the neuroprotective effect of HBOT may represent the consequence of preserved mitochondrial integrity and subsequent inhibition of the mPTP and reduction of the mitochondrial pathway of apoptosis.

Immunohistochemical expression of peripheral benzodiazepine receptors in human astrocytomas and its correlation with grade of malignancy, proliferation, apoptosis and survival

Peripheral benzodiazepine receptors (PBR) are widely distributed in peripheral tissues, astrocytes, and microglia of the brain. They are involved in apoptosis, proliferation, and many other processes, such as steroidogenesis in adrenal glands, male and female gonads, biological adaptation to stress, etc. It has been established that the expression of PBR in astrocytomas is higher than in the normal brain. The goal of this study was to explore the correlation of the immunohistochemical expression of PBR in astrocytomas with the grade of malignancy and rates of apoptosis, proliferation and survival. In 130 cases of astrocytomas (25 grade I, 25 grade II, 20 grade III, 60 grade IV), paraffin sections were stained immunohistochemically for PBR and MIB-1(Ki-67). TUNEL assay was used for evaluation of apoptosis. It was found that the intensity and extent of staining for PBR had a strong direct correlation with the grade of malignancy of the tumor, along with proliferative and apoptotic indices. The highest expression of PBR was in glioblastomas grade IV, especially around areas of necrosis. There was a strong negative correlation between PBR expression and survival. The results of this study may be applied in the pathological diagnosis of astrocytomas as an additional clue in establishing tumor grade; they may be used in the imaging of astrocytomas, both for diagnosis and follow-up, by the application of positron emission tomography scanning with PBR specific ligands. Targeting of PBR in high-grade gliomas may be a promising approach, achieving more specific anti-tumor effect.

Evaluation of the apoptosis-related proteins of the BCL-2 family In the traumatic penumbra area of the rat model of cerebral contusion, treated by hyperbaric oxygen therapy: a quantitative immunohistochemical study

The growth and progression of traumatic brain injury (TBI) lesions depend significantly on developments in the traumatic penumbra area, perilesional region, where delayed neuronal death occurs. Recent data supports the important role of apoptosis in delayed cell death in TBI. Previously we demonstrated a significant reduction of apoptosis in traumatic penumbra in animals treated by hyperbaric oxygen (HBO).In this study we evaluate the expression of apoptosis-related proteins of the Bcl-2 family (Bcl-2, Bax and Bcl-xL) in the traumatic penumbra area in correlation with the extent of apoptosis in the rat model of focal cerebral contusion, treated by HBO. Sprague-Dawley rats underwent cortical dynamic deformation, some with subsequent hypoxemia. A group of both hypoxemic and non-hypoxemic animals was treated by HBO. The pathological study was based on immunohistochemical staining of the brain sections for Bcl-2, Bax and Bcl-xL with quantitative evaluation of staining by image analysis. The expression of Bcl-2 in hypoxemic animals was lower than in non-hypoxemic animals, but a significant increase in Bcl-2 expression was seen in both groups after HBO treatment. Bcl-xL also demonstrated an increase after HBO treatment but less significant. Staining for Bax protein did not demonstrate significant change after treatment. These data correlate well with the reduction of TUNEL-positive cells in traumatic penumbra after HBO treatment. We concluded that the apoptotic mechanisms are important in delayed cell death in TBI and that post-traumatic hypoxemia increases the intensity of apoptosis, probably through a decrease in Bcl-2 and Bcl-xL expression which normally repress apoptosis. The beneficial effect of HBO treatment in our model of brain contusion correlates well with the increased expression of anti-apoptotic proteins (Bcl-2 and Bcl-xL) following treatment and the appropriate decrease in the extent of apoptosis. In light of these results, the usage of HBO is justified as neuroprotective treament in TBI.

Neuroprotective effect of Ro5-4864 following brain injury

The 18 kDa translocator protein (TSPO) is a protein complex located at the outer mitochondrial membrane and interacting with the mitochondrial permeability transition pore (mPTP), indicating its involvement in the control of mPTP opening. We intended to explore the effect of TSPO ligands, PK 11195 and Ro5-4864 on apoptosis in a rat model of cortical injury. Sprague-Dawley rats received a daily intraperitoneal injection of dimethylsulfoxide (vehicle), PK 11195, or Ro5-4864, starting 2 days prior the injury and a third injection after the injury. At 6 weeks, immunohistochemistry analysis showed that Ro5-4864 resulted in a significant increase in the number of surviving neurons and in the density of the neurofilament network in the perilesional cortex in comparison with animals of the vehicle and PK 11195 groups. In tissue samples dissected from the injured area, Ro5-4864 caused a significant reduction in activation of caspases 3 and 9 but not of caspase 8 in comparison with the vehicle and PK 11195 groups. In addition, measurements of transmembrane mitochondrial potential of mitochondria (Deltapsi(M)) isolated from normal rat brain showed that loss of Deltapsi(M) induced by recombinant Bax could be significantly reduced by Ro5-4864 in a concentration-dependent manner. Our findings indicate that the neuroprotective effect shown by Ro5-4864 in the present model of brain injury involves the mitochondrial pathway of apoptosis modulation of mPTP.

Relative effects of mannitol and hypertonic saline on calpain activity, apoptosis and polymorphonuclear infiltration in traumatic focal brain injury.

The purpose of this study was to compare the relative effects of mannitol and hypertonic saline (HTS) on calpain activity, apoptosis and neuroinflammatory response induced by experimental cortical contusion. Four groups of 5 Sprague-Dawley male rats were submitted to focal brain injury produced by exposing the parietal cortex to dynamic cortical deformation. Groups were defined by rescucitation fluids administered 30 min post-injury as follows: group 1-0.9% normal saline 2 ml/kg; group 2-mannitol 20% 0.5 g/kg; group 3-HTS 2 ml/kg; group 4-HTS 4 ml/kg. At 72 h, animals were sacrificed. Paraffin-mounted sections of were stained for mu-Calpain, TUNEL, active caspase 3 and myeloperoxidase. There was no difference in the lesion size between the different groups. In contrast, there was a significant reduction in calpain and apoptosis activity and in the neuroinflammatory response in animals receiving HTS. Although mannitol proved to significantly decrease the neuroinflammatory response and calpain activity, it did not affect apoptosis, and its effect was significantly less than that of HTS. Importantly, the effect of HTS was mostly independent from the infused volume. Our results show that HTS promotes cell survival and reduces secondary brain damage following TBI. This protective effect was evidenced at rather small infused volumes, proved to encompass several cellular and molecular mechanisms involved in secondary cell death and could not be related to relief of intracranial pressure. These findings suggest that the high osmolality of HTS may have protective effects besides its impact on brain edema.

Gliosarcoma with liposarcomatous differentiation: the new member of the lipid-containing brain tumors family.

Gliosarcoma is a rare malignant, biphasic brain tumor composed of glioblastoma multiforme and sarcomatous components. Various types of sarcomatous differentiation are described in this tumor: fibrosarcomatous, malignant fibrous histiocytoma-like, chondrosarcomatous and osteosarcomatous types. We report an extremely unusual variant of liposarcomatous differentiation in gliosarcoma in 72-year-old woman. Fat cells were presented by atypical multivacuolar and monovacuolar lipoblasts, stained positive for S100. p53 that was positive in both glial and mesenchymal cells of the tumor were negative in the lipoblasts. To the best of our knowledge, this is the first report in the literature of liposarcomatous differentiation in gliosarcoma.

Primary malignant melanoma of the anterior mediastinum in a child.

Primary malignant melanoma of the mediastinum is extremely rare. We report a case not previously reported of primary malignant melanoma located in the mediastinum in a 11-year-old boy. The tumor could not be completely resected as a result of extensive invasion of the large blood vessels. Histologically, the tumor was heavily pigmented and composed of vague fascicles of spindle cells intermingled with epithelioid cells. Immunohistochemical analysis showed vimentin, S-100 protein, Melan-A, and HMB-45 immunoreactivity in most of the tumor cells. Nearly 50% of the tumor cells were also positive for p53. It is suggested that primary malignant melanoma of the anterior mediastinum may have a histogenetic relationship to the recently described aggregates of nevus cells in the thymus or mediastinal lymph nodes.

Metastatic Rhabdoid Meningioma with BRAF V600E Mutation and Good Response to Personalized Therapy: Case Report and Review of the Literature.

Rhabdoid meningioma is an aggressive phenotype of meningioma, associated with a poor prognosis. We present a very rare case of high-grade meningioma with rhabdoid features that eventually expressed in a coma state. Comprehensive genomic profiling using a Next Generation Sequencing (NGS) assay revealed three genomic alterations: activating BRAF mutation (V600E), loss of CDKN2A/2B, and APC I1307K. After treatment with BRAF inhibitor (dabrafenib), the childs clinical condition improved progressively. After seven months, an MEK inhibitor was added (trametinib).

Accelerated pulmonary nodulosis and sterile pleural effusion in a patient with psoriatic arthropathy during methotrexate therapy: a case report.

Pulmonary nodulosis and sterile pleural exudates are well-known extra-articular manifestations in rheumatoid arthritis patients with a positive rheumatoid factor. In some patients, treatment with methotrexate has been postulated as the trigger of these complications. We report a patient with psoriatic arthropathy, negative RF, negative anticyclic citrulinated peptide antibodies but positive antibodies to cardiolipin who developed massive sterile pleural empyema and multiple cavitary pulmonary nodules during methotrexate treatment. We suggest that awareness of methotrexate-induced lung and pleural complications should be extended to other than rheumatoid arthritis diseases, not necessarily accompanied by rheumatoid factor or anticyclic citrulinated peptide antibodies.