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PubMed1983

Activity of neuron-specific enolase in normal and lesioned rat brain.

Rat brain contains 3 forms of enolase, a neuron-specific form (NSE), a hybrid form, and a non-neuronal form (NNE) which were separated by DEAE-cellulose column chromatography. The enolase activity corresponding to each form of the enzyme eluted from the columns was determined spectrophotometrically. Using this assay procedure, an activity ratio (%NNE/%NSE) was calculated for cerebellum, brainstem, sciatic nerve, adrenals and liver. The results indicated excellent agreement between this enzymatically determined ratio and published values of a similar ratio (NNE/NSE) determined by radioimmunoassay for enzyme protein. Following in vivo destruction of neurons by intracerebral injection of the selective neurotoxin, kainic acid, there was a significant decrease in the activity of NSE and hybrid enolase (neuronal forms) and no change in the activity of NNE (glial form). These data indicate that separation and measurement of enolase species is useful to determine levels of these species in normal tissue and to estimate neuronal damage biochemically in brain lesions.

Animals↗
PubMed1994

Product inhibition of reversible enzyme-catalysed reactions.

Product inhibition studies of reversible reactions can give unusual kinetic patterns. A plot of rate versus substrate concentration may appear to be sigmoidal and the double reciprocal plot will show upward curvature. This apparent positive cooperativity is due to the simultaneous occurrence of both the forward and reverse reaction. By fitting the appropriate rate equation to the data it is possible to determine the maximum velocity and Michaelis constant for both forward and reverse reaction from experiments conducted in one direction only.

Enzymes↗
PubMed1984

Neuron-specific enolase in cerebrospinal fluid: a possible indicator of neuronal damage in kainic acid lesions.

The presence of the neuron specific enolase (NSE) has been tested by sandwich enzyme immunoassay in cerebrospinal fluid (CSF) of rats after intrastriatal injection of various amounts of kainic acid (KA). Incremental release of NSE was observed in CSF for increasing concentrations of injected KA. Still, a significant decrease of NSE striatal content was detected only with the two maximal amounts of KA infused. These data indicate that measurements of NSE in CSF might be a more sensitive index of neuronal damage than the actual assay within the tissue, and also present the advantage of being a non-invasive method of investigation.

Animals↗
PubMed2005

Upregulation of Group I metabotropic glutamate receptors in neurons and astrocytes in the dorsal horn following spinal cord injury.

Of the glutamate receptor types, the metabotropic glutamate receptors (mGluRs) are G proteins coupled and can initiate a number of intracellular pathways leading to hyperexcitability of spinal neurons. In this study, we tested the expression of mGluRs to determine which cell types might contribute to sustained neuronal hyperexcitability in the lumbar enlargement with postoperative day (POD) 7 (early), 14 (late), and 30 (chronic phase) following spinal cord injury (SCI) by unilateral hemisection at T13 in Sprague-Dawley rats. Expression was determined by confocal analyses of immunocytochemical reaction product of neurons (NeuN positive) and astrocytes (GFAP positive) in the dorsal horn on both sides of the L4 segment. Neurons were divided into two sizes: small (<20 microm) and large (>35 microm), for physiological reasons. We report a significant increase of mGluR(1) expression in large and small neurons of the dorsal horn on both sides of the cord in late and chronic phases when compared to control sham groups. Expression of mGluR(2/3) significantly increased in large neurons on the ipsilateral (hemisected) side in the late phase. Expression of mGluR(5) significantly increased in large neurons in early, late, and chronic phases. In addition, mGluR(1) and mGluR(5) expression after hemisection was significantly increased in astrocytes in early, late, and chronic phases; whereas mGluR(2/3) did not display any significant changes. In conclusion, our data demonstrate long-term changes in expression levels of Group I mGluRs (mGluR(1) and mGluR(5)) in both neurons and astrocytes in segments below a unilateral SCI. Thus, permanent alterations in dorsal horn receptor expression may play important roles in transmission of nociceptive responses in the spinal cord following SCI.

Animals↗
PubMedDate not supplied

Orbital meningioma with a granular cell component in a dog, with extracranial metastasis.

A meningioma with a significant component of granular cells is described in the left ocular orbit of a 5-year-old male Golden retriever dog that presented with exophthalmos. The neoplastic mass surrounded the optic nerve. Microscopically, the tumour was characterized by nests of large, round to polygonal cells, variable in size, with eccentric nuclei and abundant eosinophilic cytoplasm, containing PAS-positive granules. In focal areas, cells were smaller and occasionally formed whorl-like structures. Immunohistochemical analysis revealed that neoplastic cells reacted positively for vimentin and, with less intensity, for neuron specific enolase and S-100, whereas they were negative for glial fibrillary acidic protein and cytokeratins. Metastatic growths, formed by similar cells, were seen in the lung and heart.

Animals↗
PubMed2002

The effects of osmotic and hydrostatic pressures on macromolecular systems.

Osmotic pressure and hydrostatic pressure can be used effectively to probe the behavior of biologically important macromolecules and their complexes. Using the two techniques requires a theoretical framework as well as knowledge of the more common pitfalls. Both are discussed in this review in the context of several examples.

Animals↗
PubMed2000

Quantitative immunochemistry on neuronal loss, reactive gliosis and BBB damage in cortex/striatum and hippocampus/amygdala after systemic kainic acid administration.

Cell specific markers were quantified in the hippocampus, the amygdala/pyriform cortex, the frontal cerebral cortex and the striatum of the rat brain after systemic administration of kainic acid. Neuron specific enolase (NSE) reflects loss of neurons, glial fibrillary acidic protein (GFAP) reflects reactive gliosis, and brain levels of serum proteins measures blood-brain-barrier permeability. While the concentration of NSE remained unaffected in the frontal cerebral cortex and the striatum, their GFAP content increased during the first three days. In the hippocampus and amygdala, NSE levels decreased significantly. GFAP levels in the hippocampus were unaffected after one day and decreased in the amygdala/pyriform cortex. After that, GFAP increased strikingly until day 9 or, in the case of amygdala/pyriform cortex, even longer. This biphasic time course for GFAP was accompanied by a decrease of S-100 during days 1-9 followed by a significant increase at day 27 above the initial level. The regional differences in GFAP and S-100 could result from the degree of neuronal degeneration, the astrocytic receptor set-up and/or effects on the blood-brain barrier.

Amygdala↗
PubMed1992

Structure of the bis divalent cation complex with phosphonoacetohydroxamate at the active site of enolase.

Phosphonoacetohydroxamate (PhAH) is a tight-binding (Ki = 15 pM) inhibitor of enolase that is believed to mimic the aci-carboxylate form of the intermediate carbanion in the reaction [Anderson, V. E., Weiss, P. M., & Cleland, W. W. (1984) Biochemistry 23, 2779]. Electron paramagnetic resonance (EPR) spectroscopy of Mn2+ has been used to map sites of interaction of PhAH with the two divalent cations at the active site of enolase from bakers' yeast. EPR spectra of enolase-PhAH complexes containing two Mn2+ bound at the active site contain multiple fine structure transitions each with a 45-G 55Mn hyperfine spacing that is a characteristic of spin exchange coupled pairs of Mn2+. Magnetically dilute complexes were obtained by preparation of specific Mg2+/Mn2+ hybrid complexes by manipulating the order of addition of the divalent metal species. Thus, Mn2+ was placed in the higher affinity site by addition of 1 equiv of Mn2+ to a solution of enolase and PhAH, followed by addition of 1 equiv of Mg2+. Reversing the order of addition of Mg2+ and Mn2+ placed Mn2+ in the lower affinity site. Regiospecifically 17O-labeled forms of PhAH were prepared, and the binding of the functional groups on PhAH to Mn2+ at the two metal ion sites was determined from the presence or absence of 17O superhyperfine coupling in the EPR signals. The hydroxamate oxygen is a ligand of Mn2+ at the higher affinity site, a phosphonate oxygen is a ligand of Mn2+ at the lower affinity site, and the carbonyl oxygen is a mu-O bridge of the two metal ions.(ABSTRACT TRUNCATED AT 250 WORDS)

Binding Sites↗
PubMed2003

Comparative evaluation of the performance of two commercial kits for the detection of central nervous system tissue in meat.

The ScheBo Brainostic test, which detects neuron-specific enolase by Western blotting, and the r-Biopharm Ridascreen Risk Material ELISA test, which detects the presence of glial fibrillary acidic protein, were evaluated using meats containing spinal cord and brain central nervous system (CNS) tissue from ovine and bovine species. The meats were pork, cooked pork sausage, raw minced lamb and cooked minced lamb. Spiking of the CNS tissue ranged from 0.01 to 5%. No false-positives were observed with either test using the manufacturers' analytical protocols. The presence or absence of CNS tissue was correctly determined in 20 of 20 samples using the ScheBo Brainostic test and 18 of 20 samples using the Ridascreen tests. When results were placed in categories according to quantity of CNS tissue detected, 19 of 20 samples were classified correctly using the Brainostic test and 14 of 20 samples using the Ridascreen test. Both kits were considered appropriate for reporting the presence of 1% or more CNS tissue in meat products, but the ScheBo Brainostic test was more consistent at detecting the presence of CNS tissues below the 1% level. Overall, the format of the Ridascreen test was technically easier to use, and the data simpler to interpret.

Animals↗
PubMed1986

Evidence for neural origin and PAS-positive variants of the malignant small cell tumor of thoracopulmonary region ("Askin tumor").

The differential diagnoses of childhood and adolescent tumors composed of small round cells include a distinctive clinicopathological entity called malignant small cell tumor (MSCT) of the thoracopulmonary region in childhood. In the present study, 15 such tumors that fulfilled the criteria by Askin et al. were examined for features of possible neural differentiation by light and electron microscopy (EM). With hematoxylin-eosin stain (H&E) the tumors were made up of small undifferentiated cells; rosette formation was noticed in four cases. By immunohistochemistry all 15 tumors were positive for neuron/specific enolase (NSE), which is a specific marker for neural elements and their tumors including neuroblastomas. Ten of 15 MSCT had positive PAS staining. Ultrastructurally dense core (neurosecretory) granules and cell processes indicative of neuronal differentiation could be recognized in 10 of 14 tumors. The dense core granules were often atypical. Filamentous cytoskeleton, never observed in Ewing's sarcoma, was often present. Based on the current results, MSCT of the thoracopulmonary region can be considered a peripheral neuroectodermal tumor with the possible origin in intercostal nerves. MSCTs are generally misdiagnosed as Ewing's sarcoma due to their primitive appearance in H&E sections and their periodic acid-Schiff positivity. NSE immunostaining, preferably augmented by electron microscopy, is necessary for their correct diagnosis.

Adolescent↗
PubMed2004

Solitary retinal astrocytoma in a dog.

An intraocular mass from a 13-year old Husky-mix dog was diagnosed as retinal astrocytoma. The mass arose from the ganglion layer of the retina and occupied 50% of the vitreous space. The mass was immunoreactive for neuron-specific enolase, S-100, vimentin, and glial fibrillary acidic protein. The neoplasm had characteristics similar to solitary retinal astrocytomas of humans but lacked the marked vascularity.

Animals↗
PubMed2000

[Effect of regional hypothermia on cerebrospinal fluid parameters during thoracoabdominal aorta clamping in dogs].

The most feared complication of thoracoabdominal clamping is the paraplegia or paraparesis following ischemic injury of the spinal cord. Early intraoperative recognition of this complication has not been solved yet. In our earlier experiment we found significant alterations of CSF glucose, lactate, pCO2 and Neuron Specific Enolase (NSE) levels during 60 minutes thoracoabdominal aortic clamping in dogs. The analysis of these parameters proved to be proper to follow metabolism of the spinal cord during this type of surgery. In our present paper we studied protective effect of regional hypothermia using peridural cooling by registration of above parameters. Statistical analysis of our data showed prevention of production of anaerobe metabolites in animals with icy peridural irrigation. The biochemical approach is appropriate for monitoring effectiveness of regional hypothermia of the spinal cord during aortic surgery.

Animals↗
PubMed2005

Diagnosis and treatment of solid-pseudopapillary tumors of the pancreas.

BACKGROUND: Solid-pseudopapillary tumors (SPTs) of the pancreas have been reported as rare lesions with "low malignant potential" occurring mainly in young women. This study was designed to define the clinicopathological characteristics and the effect of surgical intervention. METHODS: A retrospective clinical analysis was made of 21 patients with solid-pseudopapillary tumor of the pancreas admitted from June 1994 to December 2004. RESULTS: Abdominal pain as the major complaint was found in 13 patients, and palpable abdominal mass in 7. Imaging examination showed the abdominal mass clearly, but diagnosis was not defined. In 12 patients, tumors were located in the pancreatic head and in 9 patients, in the pancreatic tail. The average diameter of the tumor was 9.5 cm (range, 3-20 cm). One patient had liver metastasis. The diagnosis of the tumor was proved pathologically during operation in 14 patients, and other 3 patients who had been diagnosed as having insulinoma and other malignant tumors were confirmed by paraffin section and enzyme labeling after operation. Eighteen patients (85.7%) were followed up with a median period of 24 months, 1-60 months without tumor recurrence. CONCLUSION: Huge pancreatic masses of the pancreas in young women are suggestive of solid-pseudopapillary tumors. Aggressive surgical therapy can result in good prognosis in these patients.

Adolescent↗