Prolactin selectively transported to cerebrospinal fluid from blood under hypoxic/ischemic conditions.

AIM: The aim of this study was to determine and to verify the correlation between the amount of prolactin (PRL) levels in the blood and in the cerebrospinal fluid (CSF) by various causes of death as an indicator for acute hypoxia in autopsy cases. It is to confirm the cause of the change in prolactin level in CSF by in vitro system. MATERIALS AND METHODS: In autopsy materials, the PRL levels in blood from the right heart ventricle and in the CSF were measured by chemiluminescent enzyme immunoassay, and changes in the percentage of PRL-positive cells in the pituitary gland were examined using an immunohistochemical method. Furthermore, an inverted culture method was used as an in vitro model of the blood-CSF barrier using epithelial cells of the human choroid plexus (HIBCPP cell line) and SDR-P-1D5 or MSH-P3 (PRL-secreting cell line derived from miniature swine hypophysis) under normoxic or hypoxic (5% oxygen) conditions, and as an index of cell activity, we used Vascular Endothelial Growth Factor (VEGF). RESULTS AND DISCUSSION: Serum PRL levels were not significantly different between hypoxia/ischemia cases and other causes of death. However, PRL levels in CSF were three times higher in cases of hypoxia/ischemia than in those of the other causes of death. In the cultured cell under the hypoxia condition, PRL and VEGF showed a high concentration at 10 min. We established a brain-CSF barrier model to clarify the mechanism of PRL transport to CSF from blood, the PRL concentrations from blood to CSF increased under hypoxic conditions from 5 min. These results suggested that PRL moves in CSF through choroidal epithelium from blood within a short time. PRL is hypothesized to protect the hypoxic/ischemic brain, and this may be because of the increased transportation of the choroid plexus epithelial cells.

Aspects of trapping efficiency and matrix effects in the development of a restricted-access-media-based trap-and-elute liquid chromatography with mass spectrometry method.

Online restricted access media with liquid chromatography and tandem mass spectrometry for the direct analysis of small molecules in biological fluids represents an interesting alternative to time-demanding traditional sample preparation techniques. In this study, important considerations concerning the development of a restricted access media with liquid chromatography and tandem mass spectrometry method for the analysis of dansylated estrogens in biological matrix are presented. Parameters influencing peak tailing and trapping efficiency were evaluated. The key factors included the ion strength of the mobile phase, a loading flow rate of the sample onto the trap column, and selection of a proper stationary phase of the trap column for a given set of analytes. These parameters have proven to be essential for minimizing any unwanted chromatographic peak tailing. The bulk derivatization of the analytes in the biological fluids and its relationship to the observed matrix effects was evaluated as well.

Intraparenchymal microdialysis after acute spinal cord injury reveals differential metabolic responses to contusive versus compressive mechanisms of injury.

In animal models, spinal cord injury (SCI) is typically imparted by contusion alone (e.g., weight drop) or by compression alone (e.g., clip compression). In humans, however, the cord is typically injured by a combination of violent contusion followed by varying degrees of ongoing mechanical compression. Understanding how the combination of contusion and compression influences the early pathophysiology of SCI is important for the pre-clinical development of neuroprotective therapies that are applicable to the human condition. Disturbances in the metabolism of energy-related substrates such as lactate, pyruvate, and glucose are important aspects of secondary damage. In this study, we used a porcine model of traumatic SCI to determine the extent to which these metabolites were influenced by contusion followed by sustained compression, using the microdialysis technique. Following contusion injury, lactate and pyruvate levels near the epicenter both increased, while glucose remained quite stable. When the contusion injury was followed by sustained compression, we observed a transient rise in lactate, while pyruvate and glucose levels dropped rapidly, which may reflect decreased regional spinal cord blood flow. Furthermore, contusion with sustained compression produced a prolonged and dramatic increase in the lactate-pyruvate (L/P) ratio as a marker of tissue hypoxia, whereas after contusion injury alone, a transient and less significant elevation of the L/P ratio was observed. In this study, we demonstrate that disturbances in energy metabolism within the injured spinal cord vary greatly depending upon the biomechanical nature of the injury. Such differences are likely to be relevant to the applicability of novel therapies targeting specific aspects of the early secondary injury cascade after acute human SCI.

The CSF creatine kinase-BB isoenzyme activity in experimental lumbar spinal stenosis model.

STUDY DESIGN: An investigation of creatine kinase (CK)-BB isoenzyme activity in cerebrospinal fluid (CSF) of the rabbits after experimentally induced spinal stenosis. OBJECTIVES: To create a lumbar spinal stenosis (LSS) model at conus medullaris level without laminectomy in rabbits and to investigate the importance of CK-BB isoenzyme activity in CSF associated with electrophysiologic and histopathologic changes in the spinal cord. SUMMARY OF BACKGROUND DATA: LSS is a disorder characterized by leg pain and difficulty of walking. Narrowing of the spinal canal and compression on the spinal cord and nerves are the main features of spinal stenosis. METHODS: Fifteen male albino rabbits were used in this study. A reproducible, subacute LSS model was created in all rabbits, and CSF CK-BB activity was measured above and below the stenosis level. The electrophysiologic evaluation and the histopathologic examination of the conus medullaris were also performed in each rabbit. RESULTS: The CK-BB activity was 71.5% in CSF samples that were obtained below the stenosis. The activity was 44.5% in samples obtained above the stenosis and 43.6% in nonstenotic rabbits. In the electrophysiologic studies, the mean amplitudes were decreased and the latency values were lengthened in all ascending and descending nerve potentials at both sides of the stenosis. The number of the neural cells was decreased and imperception of the nucleolus of neural cells and vacuolar degeneration were observed in the histopathologic examination of conus medullaris. CONCLUSIONS: The activity of CK-BB isoenzyme was increased in CSF of which the circulation was disturbed as a result of neural ischemia, which was accepted in the pathophysiology of LSS.

New targets for pharmacological intervention in the glutamatergic synapse.

Excitotoxicity is thought to be a major mechanism in many human disease states such as ischemia, trauma, epilepsy and chronic neurodegenerative disorders. Briefly, synaptic overactivity leads to the excessive release of glutamate that activates postsynaptic cell membrane receptors, which upon activation open their associated ion channel pore to produce ion influx. To date, although molecular basis of glutamate toxicity remain uncertain, there is general agreement that N-methyl-d-aspartate (NMDA) subtype of ionotropic glutamate receptors plays a key role in mediating at least some aspects of glutamate neurotoxicity. On this view, research has focused in the discovery of new compounds able to either reduce glutamate release or activation of postsynaptic NMDA receptors. Although NMDA receptor antagonists prevent excitotoxicity in cellular and animal models, these drugs have limited usefulness clinically. Side effects such as psychosis, nausea, vomiting, memory impairment, and neuronal cell death accompany complete NMDA receptor blockade, dramatizing the crucial role of the NMDA receptor in normal neuronal processes. Recently, however, well-tolerated compounds such as memantine has been shown to be able to block excitotoxic cell death in a clinically tolerated manner. Understanding the biochemical properties of the multitude of NMDA receptor subtypes offers the possibility of developing more effective and clinically useful drugs. The increasing knowledge of the structure and function of this postsynaptic NMDA complex may improve the identification of specific molecular targets whose pharmacological or genetic manipulation might lead to innovative therapies for brain disorders.

Cell culture isolation of a transmissible cytotoxicity from a human sample of cerebrospinal fluid.

We investigated a transmissible cytotoxicity isolated in VERO cell cultures from a sample of cerebrospinal fluid (CSF) drawn from a woman with ischemic brain injury. Amorphous aggregates formed by subunities of approximately 11 nm of diameter were detected in ultracentrifugates from partially purified cytotoxic cell preparations in the absence of virion-like particles which might justify the trasmissibility of this cytotoxic activity. Results of chemico-physical studies provided indications on the presence in the CSF of two protease-resistant acidic glycoproteins of about 39 and 27 kDa, respectively. The conformational change of a proteinic molecule may associate with particular properties such as tendency to aggregation, resistance to proteolysis, cytotoxicity. Considering that these same properties are shared by proteins present in the CSF sample under study, a hypothesis to pursue is that the CSF inoculum we isolated contained misfolded proteins formed in vivo following the ischemic injury of brain tissue. As far as the in vitro transmissibility of the cytotoxic activity, this could take place following the reproduction of the alterations of those proteins, independently of the original cause(s) which have fostered their formation in vivo.

Measurement of free fatty acids in cerebrospinal fluid from patients with hemorrhagic and ischemic stroke.

Free fatty acid (FFA) concentrations in cerebrospinal fluid (CSF) from patients with ischemic and hemorrhagic stroke (n=25) and in contemporary controls (n=73) were examined using HPLC. Concentrations of CSF FFAs from ischemic and hemorrhagic stroke patients obtained within 48 h of the insult were significantly greater than in control patients. Higher concentrations of polyunsaturated fatty acids (PUFAs) in CSF obtained within 48 h of insult were associated with significantly lower (P<0.05) admission Glasgow Coma Scale scores and worse outcome at the time of hospital discharge, using the Glasgow Outcome Scale (P<0.01).

The effects of moderate hypothermia and intrathecal tetracaine on glutamate concentrations of intrathecal dialysate and neurologic and histopathologic outcome in transient spinal cord ischemia in rabbits.

UNLABELLED: The aim of the present study was to compare the effects of intrathecal tetracaine (a sodium channel blocker) with those of moderate hypothermia on glutamate concentrations of intrathecal dialysate, hindlimb motor functions, and histopathology in spinal cord ischemia. New Zealand White rabbits implanted with an intrathecal dialysis probe were assigned to one of the three groups (seven in each): control (temperature 38 degrees C), tetracaine (tetracaine 0.5%, 0.6 mL, given intrathecally 30 min before ischemia, 38 degrees C), or moderate hypothermia (32 degrees C). Spinal cord ischemia (20 min) was produced by occlusion of the abdominal aorta during isoflurane (1%) anesthesia. Glutamate concentrations significantly increased during ischemia in all groups, but the levels in the moderate hypothermia group were significantly lower than those in the control and tetracaine groups. Neurologic status (24 and 48 h after reperfusion) and histopathology (48 h) in the moderate hypothermia group were significantly better than in the other two groups. There were no significant differences between the tetracaine and control groups in either glutamate concentrations, neurologic status, or histopathology. We conclude that intrathecal tetracaine does not provide any protection against ischemic spinal cord injury, whereas moderate hypothermia does. IMPLICATIONS: Sodium channel blockers, including local anesthetics, have been shown to reduce glutamate release in brain ischemia and have a neuroprotective effect. However, in the present study, intrathecal tetracaine did not attenuate either glutamate release or the neurologic or histopathologic outcome in spinal cord ischemia, whereas moderate hypothermia did.

Changes in cerebrospinal fluid pressure and lactate concentrations during thoracoabdominal aortic aneurysm surgery.

BACKGROUND: Although ischemic injury to the spinal cord is a well-known complication of aortic surgery, no metabolic markers have been identified as predictors of an adverse outcome. This study evaluated the effect of cerebrospinal fluid (CSF) drainage, with and without distal femoral perfusion or moderate hypothermia on blood and CSF lactate concentrations and CSF pressure during thoracoabdominal aortic aneurysm surgery. METHODS: Three nonconcurrent groups of patients were studied prospectively: patients with normal body temperature (35 degrees C) but without distal femoral bypass (n = 6), patients with normal body temperature with bypass (n = 7), and patients with hypothermia (30 degrees C) and bypass (n = 8). In all patients, CSF pressure was recorded before, during, and after aortic cross-clamping. During the surgical repair, CSF drainage was performed using a 4-Fr intrathecal silicone catheter. Blood and CSF lactate concentrations were measured throughout the operation. RESULTS: Significant increases in blood (490%) and CSF (173%) lactate concentrations were observed during and after thoracic aortic occlusion in patients with normothermia and no bypass (P < 0.02 and 0.05, respectively). Distal perfusion attenuated the increase in both blood and CSF lactate (P < 0.01), and a further reduction was achieved with hypothermia of 30 degrees C (P < 0.001). Patients who became paraplegic showed a greater increase in CSF lactate concentrations after aortic clamp release compared with those who suffered no neurological damage (275% vs. 123% of baseline; P < 0.05). Increased CSF pressure of 42-60% (P < 0.005) was noted soon after thoracic aortic occlusion, both with and without distal femoral bypass. CONCLUSIONS: Incremental reductions in CSF lactate concentrations were achieved using distal femoral bypass and hypothermia. The reduction in CSF lactate correlated with the methods used to protect the spinal cord during thoracoabdominal aortic aneurysm surgery and was associated with better outcome. Decompression by distal bypass of the hemodynamic overload caused by aortic occlusion was insufficient to eliminate the acute increase in CSF pressure. Cerebrospinal fluid lactate measurements during high aortic surgery may accurately represent the spinal cord metabolic balance.

[The pseudotumorous course of ischemic myelopathies]. / Psevdotumoroznoe techenie ishemicheskikh mielopatii.

Study of 36 cases of ischemic myelopathy following a pseudotumorous course and 30 cases of spinal cord tumors revealed similarity and differences in the clinical manifestations which should be taken into account in differential diagnosis. Authentic differences in the content of serotonin and its metabolites in the cerebrospinal fluid and blood of this group of patients are pointed out.

Beta-endorphin in experimental canine spinal ischemia.

Plasma and cerebrospinal fluid beta-endorphin concentrations were radioimmunologically assayed in dogs subjected to spinal cord ischemia induced by infrarenal aortic ligature and in control sham-operated dogs. Plasma beta-endorphin levels rose significantly following surgery in control dogs but were unaffected by spinal ischemia. On the other hand, a significant increase in cerebrospinal fluid beta-endorphin concentration occurred after spinal ischemia, while surgical stress had no significant effect. Thus, the origins of plasma and cerebrospinal fluid beta-endorphin may be different, with the former secreted from the hypophysis and the latter from nervous tissue. Observed changes in cerebrospinal fluid beta-endorphin concentration could be related to the ischemic lesion of nervous tissue while the changes in plasma levels may reflect general stressing factors such as the surgery in our experiments.

The potassium concentration in cerebrospinal fluid in young and adult rats following complete brain ischemia. Effects of pretreatment with hypoxia.

The potassium concentration in the cisternal cerebrospinal fluid (CSF) was measured following brain ischemia in rats of different ages which has been kept at normoxia or pretreated with hypoxia (PIO2 = 70 mmHg) for 24 h. In all age groups the potassium concentration rose following ischemia. The rate of rise was relatively slow in the 4-day rat and faster in 16- and 24-day rats; beyond this age the rate of rise became slower. Pretreatment with hypoxia significantly diminished the rate of rise in CSF potassium in 4- and 8-day rats, while no effect was observed in the older age groups. It is suggested that the rate of rise in CSF potassium is inversely correlated with the capacity of surviving a period of oxygen deprivation.

[Contribution to the subacute necrotic myelitis (Foix-Alajouanine) (author's transl)]. / Beitrag zur angiodysgenetischen nekrotisierenden Myelopathie (Foix-Alajouanine)

A case of a 54 years old man with an acute lumbalgia in result of heavy labour is described. With in 7 years he developed a progressive paralysis of the upper and lower motor neuron type and an insensibility of the inferior extremities. The protein content of the cerebrospinal fluid was increased. The cells were insignificantly increased in number. No tumour was detected. The man died at the age of 62 on intoxication by infected decubitus and focal pneumonia. Autopsy revealed subacute necrotic myelitis (Foix-Alajouanine) with enlarged, varicose, and thickened extramedullary veins of the sacral, lumbal, and lower thoracic spinal cord, which was soft and diminished in size. In the grey and white matter of the cord, there were found more numerous and more prominent vessels like an angioma capillare et venosum; complete and incomplete necrosis was observed, partially with plasmatic infiltration. Some nerve cells were still present. Nerve fibres without myelin mantle were found in the spinal cord as well as in the spinal roots. The authors support the suggestion that the subacute necrotic myelitis results from a dysgenesis of the spinal venous vessels.