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PubMed1995

111In-DTPA-D-Phe-1-octreotide scintigraphy of small cell lung cancer.

Twenty-one patients with small cell lung cancer (SCLC) were investigated with 111in-octreotide (111-In-OCT) scintigraphs, 5 hours after the i.v. injection of 111 MBq of the radiotracer. Whole-body and planar scintigraphy as well as SPECT of the thorax were required. The scintigraphic results were compared to those of other conventional diagnostic procedures used for the staging and follow-up of SCLC patients. 111In-OCT detected 86% (48/56) of the lesions already known at the time of scintigraphy, being positive for all 20 SCLC lesions and negative for one lung adenocarcinoma. 111In-OCT showed a high sensitivity for mediastinal metastases (94%) and good sensitivity for bone (75%) and abdominal lymph node metastases (71%). It did not detect 2 liver metastases but revealed 5 unknown lesions which were then confirmed by other diagnostic examinations. 111In-OCT was also effective in patients with low levels of NSE. Three patients received cold octreotide for seven days to investigate whether this treatment might affect SCLC imaging. Scans were performed before and after treatment. The 111In-OCT uptake increased in the cancer lesions while the fixation in normal tissues decreased, demonstrating enhancement of SCLC imaging following cold octreotide administration.

Adenocarcinoma↗
PubMed1955

Cell structure and the metabolism of insect flight muscle.

The biochemical properties of insect flight muscle were investigated to ascertain the mechanisms whereby energy is made available for the contractile processes. It was found: 1. The endogenous respiration of muscle homogenates was diminished by starving the flies. The substrate for this respiration was probably glycogen. 2. To obtain the maximal rate of oxidation of glucose, the homogenate had to be fortified with inorganic phosphate, Mg ions, ATP, and cytochrome c. The nucleotides, AMP and ADP, were not as effective as ATP. The addition of DPN or TPN was not necessary for this system. 3. Flight muscle homogenates oxidized glycogen, some sugars, and amino acids, as well as the intermediates of the glycolytic and tricarboxylic acid cycles. Other evidence demonstrated the substrate specificity of the muscle. 4. By centrifugation, the muscle homogenate was divided into two fractions: one, a soluble fraction representing the sarcoplasm; the other, the particulate fraction which contained the fibrils and the sarcosomes. 5. The particulate fraction, alone, oxidized all the citric acid cycle intermediates, alpha-glycerophosphate, phosphopyruvate, and the amino acids, glutamic, proline, and cysteine. Regardless of the substrate, no oxygen uptake was found with the sarcoplasm by itself. 6. A recombination of the sarcoplasm and the particulate component was required for the oxidation of glycogen, the hexoses, and all the phosphorylated intermediates of glycolysis, except phosphopyruvate. 7. Isolated mitochondria accounted for all the enzymatic activity of the particulate fraction. These results demonstrate that the enzymes of intermediate metabolism are localized in the sarcoplasm or sarcosomes. The third cytological entity, the myofibrils, plays no role in the energy-providing scheme. From a functional viewpoint, the sarcoplasm and the mitochondria, in combination, furnish the energy for the actomyosin contraction. The results are discussed in relation to analogous findings in other insects and vertebrates.

Amino Acids↗
PubMed1968

A new enzyme for the interconversion of pyruvate and phosphopyruvate and its role in the C4 dicarboxylic acid pathway of photosynthesis.

1. An enzyme was isolated from leaves of tropical grasses that catalyses the reversible conversion of pyruvate, ATP and orthophosphate into phosphopyruvate, AMP and pyrophosphate. A requirement for Mg(2+) could not be replaced by Mn(2+) or Ca(2+). 2. By replacing orthophosphate with [(32)P]orthophosphate or with arsenate, evidence was provided that the orthophosphate consumed appears in pyrophosphate. 3. Without Mg(2+) or 2-mercaptoethanol the enzyme was rapidly and irreversibly inactivated. EDTA only partially replaced the requirement for the thiol compound. The enzyme was considerably more unstable at 0 degrees or when frozen than at 22 degrees . Even with the best conditions devised the enzyme lost about 25% of its activity every 3hr. 4. The activities of the enzyme in leaves of the tropical grasses sugar cane (Saccharum hybrid var. Pindar), maize (Zea mays) and sorghum (Sorghum vulgare) were comparable with their maximum photosynthesis rates. The enzyme was not detectable in leaf extracts from several other plants. 5. Its role in photosynthesis is discussed.

Adenine Nucleotides↗
PubMed1990

Localisation of neurone-specific enolase (ENO2) to 12p13.

We have localised the human cDNA for neurone-specific enolase (ENO2) to chromosome region 12p13 by in situ hybridisation. Two additional smaller peaks of hybridisation to specific chromosomal subregions were observed. That on chromosome 1p36 probably represents cross-hybridisation to the locus for nonneuronal enolase (ENO1), which has been previously localised to this chromosome and with which ENO2 shares homology. A further gene for a member of the enolase family may be responsible for the hybridisation to chromosome 17.

Chromosome Banding↗
PubMed2005

Protective effect of buflomedil in a rat model of moderate cerebral ischemia.

Buflomedil hydrochloride (CAS 55837-25-7) is a vasoactive drug with a variety of pharmacodynamic properties. Although a number of studies have been carried out to verify the beneficial effect of buflomedil in ischemic peripheral conditions, few data are reported to justify the efficacious employment of buflomedil in the treatment of cerebrovascular diseases. The aim of the present study was to better investigate the neuroprotective effect of buflomedil in normal pentobarbital-anaesthetized rats subjected to transient bilateral common artery occlusion (BCO) for 20 min. Buflomedil hydrochloride (10 mg/kg) was administered by slow intravenous infusion (90 min), starting 1 h after the onset of ischemia. The rats were sacrificed 48 h after carotid clamping. BCO caused dramatic death of hippocampal CA1 pyramidal neurons, and a significant increase in circulating levels of neuron-specific enolase (NSE) and lactate. Treatment with buflomedil attenuated ischemia-induced histological loss and damage of CA1 pyramidal cells. Furthermore, in ischemic rats, the drug restored blood lactate concentrations and serum NSE concentrations to near normal levels. These data clearly demonstrate that buflomedil is able to protect brain neurons against damage following moderate global cerebral ischemia. One could speculate that this protective effect could be related to the capability of buflomedil to improve cerebral blood flow and energy metabolism, or to a smooth muscle relaxant effect on cerebral blood vessels.

Animals↗
PubMedDate not supplied

Five tumor markers in lung cancer: significance of total and "lipid"-bound sialic acid.

Total sialic acid (TSA) and "lipid-bound" sialic acid (LSA) were evaluated in comparison to carcinoembryonic antigen (CEA) and ferritin and neuron specific enolase (NSE) in 152 untreated patients with primary lung cancer, 107 benign pulmonary disease patients and 207 notmal controls. The mean concentrations of TSA, LSA and CEA in lung cancer patients, were significantly higher than in benign and normal controls (p less than 0.001), while the mean ferritin and NSE levels were significantly higher than in normal controls only (p less than 0.001). At the designated cut-off serum levels, sensitivities of the five markers for lung cancer were in decreasing order: TSA 86.5% (greater than 80 mg/dL), LSA 77% (greater than 20 mg/dL), CEA 46.4% (greater than 5 ng/mL), ferritin 36% (greater than 300 ng/mL) and NSE 34.5% (greater than 12.5 ng/mL). Using the benign pulmonary values as negative controls the specificity of each marker was as follows: CEA 88%, ferritin 72%, NSE 58%, TSA 44% and LSA 44%. In small cell lung cancer (SCLC) patients, NSE mean concentrations and sensitivity were significantly higher than in non-small lung cancer (NSCLC) patients (9.63 +/- 4.4 versus 23.54 +/- 16.9, p less than 0.001 and 74% versus 21.4% respectively). While in NSCLC patients only CEA levels correlated well with the stage of the disease, in SCLC patients concentrations of TSA, LSA and ferritin were significantly higher in extensive than in limited disease stages. These preliminary data suggest that, although TSA and LSA are highly sensitive markers in lung cancer, their specificity is low.

Biomarkers, Tumor↗
PubMed1987

ID sequences in the genes of three brain-specific proteins.

We characterized the brain-specific gene coding for rat S-100 protein beta-subunit and found three "brain identifier (ID)" elements, which have been proposed to regulate the gene expression in rat brain. The nucleotide sequences of these elements corresponded well with that of the consensus ID element and were clearly different from those of "ID-like" elements in rat beta B1-crystallin gene, etc. ID elements were also observed in the flanking regions of rat neuron-specific enolase and cholecystokinin genes, which were expressed in the neuronal cells. Direct repeats were observed in the regions flanking ID elements.

Animals↗
PubMed1997

AMPA/kainate receptors modulate the survival in vitro of embryonic brainstem cells.

This study aimed at analyzing the involvement of (RS)-alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid/kainate (AMPA/kainate) receptors in the survival of cultured rat embryonic brainstem cells, dissociated on embryonic day 14. The cell number was estimated after pharmacological manipulation of the receptors by exposure to agonists or antagonists. The developmental stage at the moment of drug application was critical for cell survival. We observed after 8 days in vitro a much stronger decrease in the number of gamma-enolase-positive cells when the cultures were treated for 3 days with the antagonist 6,7-dinitroquinoxaline-2,3-dione (DNQX) starting on the day of plating than when DNQX was added after 5 days in vitro. Conversely, exposure to the agonists (RS)-2-amino-3-(3-hydroxy-5-tri-fluoromethyl-4-isoxazolyl)-propion ic acid (T-AMPA) or kainate for 3 days significantly reduced cell survival only when the treatment was initiated after 5 days in vitro. Survival of S-100-positive cells was not affected after exposure to either agonists or antagonists. Neither agonist nor antagonist treatment modified cell proliferation, as assessed by 5-bromo-2'-deoxyuridine (BrdU) staining, suggesting that the decrease in the number of gamma-enolase-positive cells is essentially due to cell death. If some of the processes we observed in vitro correspond to analogous events in vivo, then exposure to excitatory amino acid receptor agonists or antagonists at critical stages of embryogenesis may alter the development of the central nervous system.

Animals↗
PubMed1997

Surprising diversity and distribution of spliced leader RNAs in flatworms.

Trans-splicing generates the mature 5' ends of certain mRNAs through the addition of a small spliced leader (SL) exon to pre-mRNAs. To search for novel flatworm spliced leaders, degenerate oligonucleotides and 5' RACE [corrected was used to isolate and characterize the 5' terminal sequences of enolase mRNAs in diverse flatworms. Several new spliced leaders and their SL RNA genes were identified, characterized, and compared. All parasitic trematodes examined trans-splice enolase. A primitive polyclad turbellarian, Stylochus zebra, also contains a trans-spliced enolase mRNA. The S. zebra SL is the longest SL yet identified, 51 nucleotides. Comparison of flatworm SLs indicates that they vary significantly in sequence and length. This suggests that neither spliced leader exon sequence nor size is likely to be essential for trans-splicing in flatworms. Flatworm SL RNAs have unusual Sm binding sites with characteristics distinct from other known flatworm snRNA Sm binding sites. Predicted flatworm SL RNA secondary structures show variation exhibiting 2-4 stem loops. Although limited in sequence similarity, phylogenetically conserved regions within the diverse flatworm SL RNAs suggest that they are likely to be derived from a common ancestor and provide information on potentially important SL RNA elements. The identification of a SL in a primitive flatworm suggests that trans-splicing may have been an ancestral feature in the phylum. Representative species of other early and more recent clades within the phylum, however, do not trans-splice enolase, nor do they or representatives of several other flatworm groups, have an SL RNA with a phylogenetically conserved region identified in the current study.

Amino Acid Sequence↗
PubMed2003

Neural progenitor cells resist excitatory amino acid-induced neurotoxicity.

The applications of neural progenitor cells in clinical therapy for neural degeneration, such as Parkinson's disease, Huntington's disease, and cerebral infarction, have long been explored widely. It had been suggested that these cells may block the apoptosis of ischemia-induced neuronal damage and may themselves resist neurotoxic factors. In the present study, neural progenitor cells derived from the cortex of rodent embryos were cultured with the mitogenic agent epidermal growth factor. It was observed that these progenitor cells could self-renew and differentiate into a number of types of neurons and glial cells. By using sodium nitroprusside, glutamate, and N-methyl-D-aspartate, these neural progenitor cells were shown to have a higher resistance to neurotoxicity induced by these drugs compared with primary neuronal cells. However, the release of nitric oxide in response to glutamate by these neural progenitor cells was similar to the released by primary neuronal cells. Also, when the glutamate-stimulated increase in intracellular free Ca(2+) concentration was measured, stimulation of the glutamate receptors could not induce a significant influx of Ca(2+) into these progenitor cells until they differentiated. Our results suggest that the resistance of neural progenitor cells to neurotoxicity may be partially due to a lack of response to glutamate. In addition, some progenitor-generated neurotrophic factors may contribute to the resistance of these cells to nitric oxide-induced neurotoxicity.

Animals↗
PubMed1999

Expression of neuron-specific enolase in adult rat brain following status epilepticus.

Increased levels of neuron-specific enolase (NSE), a key glycolytic enzyme, in either the cerebrospinal fluid or the serum is correlated with both the duration and the outcome of status epilepticus. To further understand the molecular basis of seizure-induced elevations in NSE protein, we investigated NSE mRNA expression in the adult rat brain following systemic administration of kainic acid. The findings demonstrated either no change or a decrease in NSE gene expression during, and following, status epilepticus, suggesting that posttranscriptional mechanisms are responsible for seizure-induced increases in NSE protein.

Age Factors↗
PubMed1989

Neuron-specific enolase and its mRNA are highly expressed in large congenital nevi: a study using immunocytochemistry, biochemical assay, and in situ hybridization.

The malignant transformation of congenital nevocellular nevi, both large and small, is controversial and presents problems in management. The size of the lesion is taken to indicate potential malignant transformation, but this is an arbitrary scale. A more reliable biological indicator is needed to help predict the lesions at risk. Following the localization of neuron-specific enolase to most cells of the diffuse neuroendocrine system and their neoplasms (including benign and malignant melanocytic lesions), it has been suggested that its level is related to tumor activity. In a prospective trial, the presence of neuron-specific enolase immunoreactivity, its concentration, and gene expression in nevus cells were studied in 31 congenital melanocytic nevi of various sizes (1.5 cm to bathing trunk) using immunocytochemistry, biochemical assay, and in situ hybridization. Twenty-five of the 31 congenital nevi were immunoreeactive to neuron-specific enolase antiserum, with stronger immunostaining in the larger lesions. There is an apparent linear relationship between the size of the nevi and the level of neuron-specific enolase (expressed as nanograms per milligram protein). Neuron-specific enolase mRNA was highly expressed in most of the large congenital nevi (greater than 15 cm in diameter), as revealed by autoradiography following in situ hybridization. Our results show that neuron-specific enolase and its mRNA are expressed to a greater extent in large congenital nevi compared with the smaller lesions. This might prove to be a useful indicator of those lesions at risk of malignant transformation.

Adolescent↗
PubMed1990

Differential expression of the neural cell adhesion molecule NCAM 140 in human pituitary tumors.

We have analyzed the expression of the intracellular marker protein neuron specific enolase (NSE), synaptophysin (SYN) and of the cell surface marker NCAM (neural cell adhesion molecule) in both normal hypophysis and in pituitary adenomas in order to explore their potential use as diagnostic tools. All adenomas (4 prolactinomas, 3 growth hormone (GH) producing adenomas and 4 inactive adenomas) showed SYN and NSE immunoreactivity on tissue sections and this was confirmed by immunoblots. NCAM 140 (an isoform of NCAM with molecular mass 140 kDa) was detected by immunoblotting in normal human adenohypophysis, in all GH adenomas, and in three out of four inactive adenomas, but not in prolactinomas. Using highly sensitive techniques, NCAM immunoreactivity was observed by electron microscopy in all adenomas. These data indicate that NCAM 140 is a constituent of the cell surface of endocrine cells in both normal human adenohypophysis and its tumors. Since prolactinomas express very low levels of NCAM 140 compared to other hypophyseal tumors its virtual absence could be used for differential diagnosis. A combined analysis of NCAM, SYN and NSE could be useful to characterize inactive adenomas which are not immunoreactive for pituitary hormones and which may contain no or only low levels of the alpha chain of the glycoprotein hormones.

Adenoma↗
PubMed1990

Ontogenic changes in expression of neuron-specific enolase (NSE) and its mRNA in the Purkinje cells of the rat cerebellum: immunohistochemical and in situ hybridization study.

In the postnatal development of rats, neuron-specific enolase (NSE)-immunoreactivity first appeared in the Purkinje cells at postnatal day 3 (P3) and elevated strikingly at P9 when almost all the Purkinje cell somata and dendrites exhibited the intense immunoreactivity. In situ hybridization signals for NSE-mRNA also increased markedly in the Purkinje cell somata from P3 to P9. These results indicate that the NSE synthesis is transiently enhanced in the Purkinje cells from P3 to P9 at the transcriptional level. At P11 and thereafter NSE-immunoreactive Purkinje cells decreased in number, and no significant immunoreaction was detected in their somata and dendrites in the adulthood, whereas distinct immunoreactivity for NSE was still detected in the Purkinje cell axons until the adult stage. However, the signals for NSE-mRNA were still localized in the Purkinje cell somata after P11 until the adult. The possible involvement of the negative translational control and/or the axoplasmic transport of NSE was briefly discussed to explain this discrepancy between NSE-immunoreactivity and its mRNA expression in the Purkinje cells in the late postnatal development.

Animals↗