351
|
Wu H, Li J, Peng L, Teng B, Zhai Z. Effect of 764-3 on aggregation and calcium movements in aequorin-loaded human platelets. Chin Med Sci J 1996; 11:49-52. [PMID: 9206120] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
Washed human platelets were loaded with the Ca(2+)-sensitive photoprotein, aequorin, using hypoosmotic shock treatment-technique. Then aggregation and cytoplasmic ionized calcium concentration ([Ca2+]i) changes in response to collagen or thrombin were measured simultaneously in the aequorin-loaded human platelets with a Platelet Ionized Calcium Aggregometer. 764-3, an active component isolated from the Chinese medicinal herb Salvia Miltiorrhiza Bge, inhibited platelet [Ca2+]i rise as well as aggregation evoked by collagen or thrombin in the presence of extracellular Ca2+. After the extracellular Ca2+ was removed by addition of EGTA, collagen or thrombin, causing no aggregation, still elicited platelet [Ca2+]i rise which reflected Ca2+ mobilization from intraplatelet stores. Under this condition, 764-3 could also suppress platelet [Ca2+]i rise. Analysis shows that 764-3 inhibits platelet Ca2+ influx and Ca2+ mobilization with similar potency, which accounts for its suppression of platelet [Ca2+]i rise, and must contribute to its inhibition of platelet aggregation.
Collapse
Affiliation(s)
- H Wu
- Institute of Hematology, CAMS & PUMC, Tianjin
| | | | | | | | | |
Collapse
|
352
|
Song H, Peng L, Cui N. [Experimental study of human micro-urokinase gene therapy]. Zhonghua Yi Xue Za Zhi 1996; 76:100-3. [PMID: 8758439] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
OBJECTIVE To determine the feasibility and efficiency of gene therapy to thrombotic disease. METHODS The retroviral vectors containing 982 bp mUKcDNA were constructed and transfected into PA317 viral packaging cells. Recombinant retroviral particles collected from media of PA317 cells were injected into mice subcutaneous tissue, abdominal cavity and quadriceps muscle, respectively. mUK activity of plasma was measured with a synthetic substrate S-2390. Six mice were sacrificed after injection for immunofluorohistochemical staining. RESULTS The mUK activity in plasma was obviously increased (P < 0.01) and the expression of mUKcDNA was observed at local sites of injection by immunofluorohistochemical staining. The mUK activity was raised for 4 months. CONCLUSION The injection of recombinant viral particles containing transcriptional unit of mUKcDNA might be applied to the prevention and treatment of thrombotic disease.
Collapse
Affiliation(s)
- H Song
- Laboratory of Molecular Genetics, School of Basic Medical Sciences, Shanghai Medical University
| | | | | |
Collapse
|
353
|
|
354
|
Peng L, Juurlink BH, Hertz L. Pharmacological and developmental evidence that the potassium-induced stimulation of deoxyglucose uptake in astrocytes is a metabolic manifestation of increased Na(+)-K(+)-ATPase activity. Dev Neurosci 1996; 18:353-9. [PMID: 8940606 DOI: 10.1159/000111428] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
There is disagreement in the literature whether or not deoxyglucose accumulation, a measure of glycolytic activity, is increased in astrocytes during exposure to elevated concentrations of the potassium ion (K+). In the present work we have confirmed our previous finding that deoxyglucose accumulation in primary cultures of well-differentiated mouse astrocytes shows a robust increase when the K+ concentration in the incubation medium is raised to or above 12 mM. This response is inhibited by ouabain (with a half-maximum effect at approximately 0.1 mM), indicating that it is a metabolic manifestation of the activity of an Na(+)-K(+)-ATPase. The stimulation at this high level of K+ indicates a remarkably low K+ affinity of the Na(+)-K(+)-ATPase involved, enabling it to be activated by above-normal concentrations of K+. At a resting concentration of K+ (5.4 mM), at least one half of the deoxyglucose accumulation is also a reflection of Na(+)-K(+)-ATPase activity, as shown by its susceptibility to inhibition by ouabain. Ouabain has some effect even at a concentration of 0.1 microM, indicating participation of not only the alpha 1 isoform which has a low affinity to ouabain, but also of the alpha 2 isoform, which has a high affinity. The stimulatory effect of elevated K+ is absent in immature astrocytes and only develops after prolonged time in culture. It could not be evoked in a seemingly similar culture of rat astrocytes, which has previously been shown to lack Na(+)-K(+)-ATPase activity as well as the alpha 2 isoform of the ATPase. This isoform has unequivocally been found to be expressed by astrocytes in situ.
Collapse
Affiliation(s)
- L Peng
- Department of Pharmacology, University of Saskatchewan, Saskatoon, Canada
| | | | | |
Collapse
|
355
|
Hertz L, Gibbs ME, O'Dowd BS, Sedman GL, Robinson SR, Syková E, Hajek I, Hertz E, Peng L, Huang R, Ng KT. Astrocyte-neuron interaction during one-trial aversive learning in the neonate chick. Neurosci Biobehav Rev 1996; 20:537-51. [PMID: 8880738 DOI: 10.1016/0149-7634(95)00020-8] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
During two specific stages of the Gibbs-Ng model of one-trial aversive learning in the neonate chick, we have recently found unequivocal evidence for a crucial involvement of astrocytes. This evidence is metabolic (utilization of the astrocyte-specific energy store, glycogen, during normal learning and inhibition of memory formation by the astrocyte specific metabolic inhibitors, fluoroacetate and methionine sulfoximine) as well as physiological (abolition of memory formation in the presence of ethacrynic acid, an astrocyte-specific inhibitor of cellular reaccumulation of potassium ions). These findings are discussed in the present review in the framework of a more comprehensive description of metabolic and physiological neuronal-astrocytic interactions across an interstitial (extracellular) space bounded by minute processes from either cell type.
Collapse
Affiliation(s)
- L Hertz
- Department of Pharmacology, University of Saskatchewan, Saskatoon, Canada
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
356
|
Peng L, Li J, Wu H, Teng B. [Characterization of platelet activation induced by CD9 McAbs]. Zhongguo Yi Xue Ke Xue Yuan Xue Bao 1995; 17:365-70. [PMID: 8706172] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
The platelet activation induced by two anti-human platelet P24/CD9 McAbs was investigated. The results showed that the pathways of platelet aggregation induced by the two McAbs (HI117 and SJ9A4) were different and HI117 and SJ9A4 induced the phosphorylation of platelet proteins (40,000 and 20,000) when platelets were activated. However, HI117 did not cause a rise in intracellular Ca2+ concentration in activated platelets in comparison with SJ9A4 and the epitope recognized by HI117 and SJ9A4 was different and this might explain why the two CD9 McAbs played different roles in platelet activation in addition, McAbs HI117 and SJ9A4 could not promote associations of other proteins (eg: GP II b/III a) with P24/CD9 on activated human platelets. All these results indicate that the mechanisms of platelet activation induced by HI117 or SJ9A4 are different from each other. It suggests that CD9 antigen plays an importent and complex role in platelet activation.
Collapse
Affiliation(s)
- L Peng
- Institute of Hematology, CAMS and PUMC, Tianjin
| | | | | | | |
Collapse
|
357
|
Schlaepfer TE, Harris GJ, Tien AY, Peng L, Lee S, Pearlson GD. Structural differences in the cerebral cortex of healthy female and male subjects: a magnetic resonance imaging study. Psychiatry Res 1995; 61:129-35. [PMID: 8545497 DOI: 10.1016/0925-4927(95)02634-a] [Citation(s) in RCA: 140] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
There are both reproductive and nonreproductive behavioral differences between men and women. Brain regions involved in determining sexual behavior have been reported to differ between the sexes. Nonreproductive, cognitive functional differences between sexes might be reflected in higher-order cortical structural dimorphisms, which have not previously been studied. We hypothesized that cortical regions involved in verbal behavior (which is sexually dimorphic) would differ between sexes. Using magnetic resonance imaging, we assessed gray matter volumes in several cortical regions in 17 women and 43 men. Women had 23.2% (dorsolateral prefrontal cortex) and 12.8% (superior temporal gyrus) greater gray matter percentages (corrected for overall brain size and age) than men in a language-related cortical region, but not in a more visuospatially related cortical region. These data seem to establish sexually dimorphic structural differences in the cerebral cortex, consistent with prior cerebral blood flow reports.
Collapse
Affiliation(s)
- T E Schlaepfer
- Department of Psychiatry, Johns Hopkins University, Baltimore, MD 21287-7362, USA
| | | | | | | | | | | |
Collapse
|
358
|
Gao S, Liu S, Shen Z, Peng L. Morphometric analysis of spinous cell in oral submucous fibrosis. Comparison with normal mucosa, leukoplakia and squamous cell carcinoma. Chin Med J (Engl) 1995; 108:351-4. [PMID: 7555236] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
The morphometric analysis of the spinous cell in 16 specimens of oral submucous fibrosis (OSF) was made by using interactive image analysis system (IBAS-II). 19 parameters of the size and shape were chosen, and compared with normal mucosa, leukoplakia, dysplasia and carcinoma. The results indicated that the cell dimensions (area, perimeter, all kinds of diameter) and nuclear cytoplasmic ratio in OSF were between normal mucosa and dysplasia as well as carcinoma. The former showed a progressive decrease (P < 0.01), and the latter showed a progressive increase (P < 0.01). The dimensions of the nuclei did not show considerable differences among the groups (P < 0.05). A series of discriminant functions had been developed with stepwise discriminant analysis, the agreement ratio for OSF was 93.75%. The decrease of cell area and the increase of nuclear cytoplasmic ratio could reflect a malignant progress. The cell morphometric model could discriminate OSF well from other groups, suggesting that the change of the epithelium in OSF appearing in the spinous cell is specific itself.
Collapse
Affiliation(s)
- S Gao
- Stomatological Hospital, Tianjin Medical University
| | | | | | | |
Collapse
|
359
|
Abstract
It is generally believed that the antidepressant drug fluoxetine (Prozac) exerts all its effects by inhibition of serotonin uptake into neurons and an ensuing increase in the extracellular concentration of serotonin. However, these studies have confirmed and expanded our previous observation that fluoxetine on its own exerts agonist effects on astrocytes (a glial cell type), which resemble those exerted by serotonin. Fluoxetine appears to act on a different subtype of receptor (the 5-HT2C receptor [in original terminology the 5-HT1C receptor]) than the one on which micromolar concentrations of serotonin are known to act in astrocytes (the 5-HT2A receptor [in original terminology the 5-HT2 receptor]). However, this study has shown that application of serotonin to these cells stimulates glycogenolysis and causes an increase in free cytosolic concentration of calcium that is not inhibited by the 5-HT2A selective antagonist, ketanserin. Moreover, both effects are pronounced at the low nanomolar level of serotonin and, therefore, by definition, act on the 5-HT2C receptor. The concentration/response correlation is identical for the serotonin effects on free cytosolic calcium concentration and on glycogenolysis. Fluoxetine exerts similar effects, but low nanomolar concentrations have no effect, and the concentration required to obtain half-maximum response is 1-3 microM, a concentration dependence that is consistent with the plasma levels of fluoxetine during treatment with this drug.(ABSTRACT TRUNCATED AT 250 WORDS)
Collapse
Affiliation(s)
- Y Chen
- Department of Pharmacology, University of Saskatchewan, Saskatoon, Canada
| | | | | | | | | |
Collapse
|
360
|
Xiao C, Hao L, Chang W, Tao Y, Zhou Z, Peng L, Du R. Distribution of red cell blood group systems in Achang and De'ang ethnic groups in China. Gene Geogr 1994; 8:185-90. [PMID: 7662610] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
A survey on the distribution of red cell group systems, including ABO, MNSs, Rhesus and P, was carried out in the Achang and De'ang ethnic groups in Yunnan Province, South-West China. The Achangs are characterized by the highest frequency of IA in China, while the De'angs show a high frequency of IO and CDe. The distribution of these blood group systems in Achang and De'ang exhibits the same characteristics observed in other ethnic groups of South China.
Collapse
Affiliation(s)
- C Xiao
- Yunnan Family Planning Institute, Kunming, China
| | | | | | | | | | | | | |
Collapse
|
361
|
Peng L, Zhang X, Hertz L. High extracellular potassium concentrations stimulate oxidative metabolism in a glutamatergic neuronal culture and glycolysis in cultured astrocytes but have no stimulatory effect in a GABAergic neuronal culture. Brain Res 1994; 663:168-72. [PMID: 7850466 DOI: 10.1016/0006-8993(94)90475-8] [Citation(s) in RCA: 95] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Rates of deoxyglucose accumulation and of CO2 production from [U-14C]glucose, or from [U-14C]lactate or [2-14C]pyruvate (as a determination of tricarboxylic acid (TCA) cycle activity) were determined in primary cultures of either astrocytes, cerebellar granule cell neurons (utilizing glutamate as their transmitter) or cerebral cortical interneurons (utilizing GABA as their transmitter) during control ('resting') conditions and during exposure to an elevated extracellular potassium concentration, mimicking functional activity. The elevation of the extracellular potassium concentration increased the rate of deoxyglucose accumulation, but not of TCA cycle activity in astrocytes and both deoxyglucose accumulation and TCA cycle activity in cerebellar granule cells, but had no stimulatory effect in cerebral cortical neurons. Based on these observations it is suggested that the increase in energy metabolism in the CNS in vivo during functional activity mainly reflects increased active accumulation of potassium ions and extrusion of sodium ions in neurons receiving excitatory input and in adjacent astrocytes in order to re-establish pre-stimulus ion distribution across cell membranes.
Collapse
Affiliation(s)
- L Peng
- Department of Pharmacology, University of Saskatchewan, Saskatoon, OWO, Canada
| | | | | |
Collapse
|
362
|
Abstract
The immunoglobulin variable region genes of a murine anti-insulin IgG-producing hybridoma were rescued and cloned into a bacterial expression vector. The variable regions of the gamma heavy chain and the kappa light chain were expressed independently and together as a single chain antibody (scFv). The variable heavy chain alone demonstrated the ability to bind to insulin. The kappa light chain did not show any binding activity towards insulin. The scFv was constructed by PCR assembly using a (Gly4Ser)3 linker between the carboxyl end of the variable heavy chain and the amino terminus of the kappa light chain. The scFv bound insulin at an IC50 of 3.5 x 10(-8) M whereas the parent antibody bound insulin at 1.0 x 10(-8) M. Mutagenesis of the variable heavy chain complementarity determining regions (CDR) indicated that CDR1 and CDR3 were important for binding to insulin. Position 99 in CDR3 of the heavy chain was found to be a critical position for the ability of the scFv to bind to insulin.
Collapse
Affiliation(s)
- D F Lake
- Department of Microbiology, University of Arizona, Tucson 85724
| | | | | | | |
Collapse
|
363
|
Wilmott RW, Frenzke M, Kociela V, Peng L. Plasma interleukin-1 alpha and beta, tumor necrosis factor-alpha, and lipopolysaccharide concentrations during pulmonary exacerbations of cystic fibrosis. Pediatr Pulmonol 1994; 18:21-7. [PMID: 7970903 DOI: 10.1002/ppul.1950180107] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Earlier studies have reported the presence of interleukin-1 (IL-1) and tumor necrosis factor (TNF) in the plasma of patients with cystic fibrosis (CF), but the results have been inconsistent. To investigate the relationships among plasma IL-1 alpha, IL-1 beta, TNF, lipopolysaccharide (LPS), and clinical status, measurements were made before and after 14 days of intravenous antibiotic therapy in 13 patients with CF. In addition, whole blood cytokine production rates were measured in 18 hr cultures stimulated with 10 micrograms/mL LPS or sterile saline (control). On admission, patients with CF had significantly greater plasma levels of LPS and IL-1 alpha compared with 20 healthy adult controls. In response to antibiotic therapy, the patients had statistically significant increases in weight, oxygen saturation, chest radiograph score, and forced expiratory volume in 1 second. They had significant decreases in pulse rate, residual volume/total lung capacity ratio, white blood count, neutrophil count, LPS concentration, and resting energy expenditure per kg body weight. There were no significant changes in the plasma concentrations of IL-1 alpha, IL-1 beta, or TNF and no significant changes in the basal or stimulated whole blood production rates of IL-1 alpha, IL-1 beta, or TNF. The immunological variables did not correlate significantly with clinical measurements of severity or the presence of fever. It is likely that in CF local pulmonary effects of cytokines are of more pathophysiologic significance than systemic effects.
Collapse
Affiliation(s)
- R W Wilmott
- Department of Pediatrics, University of Cincinnati College of Medicine, Ohio
| | | | | | | |
Collapse
|
364
|
Peng L, Alcaraz ML, Klotz P, Kotzyba-Hibert F, Goeldner M. Photochemical labeling of membrane-associated and channel-forming domains of proteins directed by energy transfer. FEBS Lett 1994; 346:127-31. [PMID: 7515826 DOI: 10.1016/0014-5793(94)00392-0] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Singlet-singlet energy transfer reactions from excited tryptophan residues to photoactivatable probes possessing a suitable chromophore, generate reactive species in the vicinity of the protein, leading to its covalent labeling. This delayed labeling process can be used to map the membrane-surrounded regions of proteins with improved efficiency when it is applied with appropriate photoactivatable phospholipids. The same principle could also be applied to the labeling of channel-forming transmembrane domains of ion channels, provided that suitable photoactivatable permeant ions were available. Both applications will be discussed with regard to their potential and feasibility.
Collapse
Affiliation(s)
- L Peng
- Laboratoire de Chimie Bio-organique, URA 1386 CNRS, Faculté de Pharmacie, Université Louis Pasteur Strasbourg, Illkirch, France
| | | | | | | | | |
Collapse
|
365
|
Peng L, Zhang X, Hertz L. Alteration in oxidative metabolism of alanine in cerebellar granule cell cultures as a consequence of the development of the ability to utilize alanine as an amino group donor for synthesis of transmitter glutamate. Brain Res Dev Brain Res 1994; 79:128-31. [PMID: 7915213 DOI: 10.1016/0165-3806(94)90056-6] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Formation of 14CO2 from labeled alanine was measured in cultured cerebellar granule cells grown in the combined presence of alanine, alpha-ketoglutarate and glutamine or in the presence of glutamine alone. This was done in order to study whether the utilization of alpha-ketoglutarate plus alanine as precursors of transmitter glutamate, induced by culturing in the presence of these compounds, is reflected by an increase of CO2 production from alanine during stimulation with an elevated extracellular potassium concentration. Potassium stimulated CO2 production from alanine was present only in the cells grown in the combined presence of alanine, alpha-ketoglutarate and glutamine. This stimulation was abolished by glutamine, but not by ouabain, indicating that the depolarizing-induced stimulation of alanine metabolism is a consequence of increased release of transmitter glutamate formed from alanine, not a simple result of an increased metabolic rate.
Collapse
Affiliation(s)
- L Peng
- Department of Pharmacology, University of Saskatchewan, Saskatoon, Canada
| | | | | |
Collapse
|
366
|
Westergaard N, Sonnewald U, Unsgård G, Peng L, Hertz L, Schousboe A. Uptake, release, and metabolism of citrate in neurons and astrocytes in primary cultures. J Neurochem 1994; 62:1727-33. [PMID: 7908943 DOI: 10.1046/j.1471-4159.1994.62051727.x] [Citation(s) in RCA: 69] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Synthesis, uptake, release, and oxidative metabolism of citrate were investigated in neurons and astrocytes cultured from cerebral cortex or cerebellum. In addition, the possible role of citrate as a donor of the carbon skeleton for biosynthesis of neurotransmitter glutamate was studied. All cell types expressed the enzyme citrate synthase at a high activity, the cerebellar granule neurons containing the enzyme at a higher activity than that found in the astrocytes from the two brain regions or the cortical neurons. Saturable citrate uptake could not be detected in any of the cell types, but the astrocytes, and, in particular, those of cerebellar origin, had a very active de novo synthesis and release of citrate (approximately 70 nmol x h-1 x mg of protein-1). The rate of release of citrate from neurons was < 5% of this value. Using [14C]citrate it could be shown that citrate was oxidatively metabolized to 14CO2 at a modest rate (approximately 1 nmol x h-1 x mg-1 of protein) with slightly higher rates in astrocytes compared with neurons. Experiments designed to investigate the ability of exogenously supplied citrate to serve as a precursor for synthesis of transmitter glutamate in cerebellar granule neurons failed to demonstrate this. Rather than citrate serving this purpose it may be suggested that astrocytically released citrate may regulate the extracellular concentration of Ca2+ and Mg2+ by chelation, thereby modulating neuronal excitability.
Collapse
Affiliation(s)
- N Westergaard
- Department of Biological Sciences, Royal Danish School of Pharmacy, Copenhagen, Denmark
| | | | | | | | | | | |
Collapse
|
367
|
Sochocka E, Juurlink BH, Code WE, Hertz V, Peng L, Hertz L. Cell death in primary cultures of mouse neurons and astrocytes during exposure to and 'recovery' from hypoxia, substrate deprivation and simulated ischemia. Brain Res 1994; 638:21-8. [PMID: 8199861 DOI: 10.1016/0006-8993(94)90628-9] [Citation(s) in RCA: 55] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Effects of hypoxia, substrate deprivation and simulated ischemia (combined hypoxia and substrate deprivation) on cell survival during the insult itself and during a 24 h 'recovery' period were studied in primary cultures of mouse astrocytes and in cerebral cortical neuronal-astrocytic co-cultures. Cell death was determined by release of the cytosolic high molecular enzyme lactate dehydrogenase (LDH) as well as morphologically (retention of staining with rhodamine 123 and lack of staining with propidium iodide as an indicator of live cells). Glutamate concentrations were measured in the incubation media at the end of the metabolic insults. Astrocytes were very resistant to hypoxia, but less so to simulated ischemia; under both conditions the glutamate concentrations in the media remained low. Cerebral cortical neurons were almost equally susceptible to damage by hypoxia and by simulated ischemia, although hypoxia had a faster deleterious effects on some of the neurons and simulated ischemia during a long-term insult (9 h) killed all neurons, whereas a non-negligible neuronal subpopulation survived 9 h of hypoxia. Neuronal cell death after long-term hypoxia (but not after simulated ischemia) was correlated with high concentrations of glutamate in the incubation media. After certain insults, most notably relatively short lasting simulated ischemia (3 h) in neurons (which caused no increased cell death during the insult), there was a large release of LDH during the 'recovery' period.
Collapse
Affiliation(s)
- E Sochocka
- Department of Pharmacology, University of Saskatchewan, Saskatoon, Canada
| | | | | | | | | | | |
Collapse
|
368
|
Huang R, Peng L, Chen Y, Hajek I, Zhao Z, Hertz L. Signalling effect of elevated potassium concentrations and monoamines on brain energy metabolism at the cellular level. Dev Neurosci 1994; 16:337-51. [PMID: 7768214 DOI: 10.1159/000112128] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
The effects of elevated K+ concentrations and monoamine transmitters on different cell types in the CNS and on different subcellular structures in these cells are reviewed. Pronounced differences exist in the metabolic processes that are stimulated by excess K+ and by adrenergic agonists, e.g., noradrenaline. An elevation in the extracellular K+ concentration appears to enhance neuronal-astrocytic interaction by stimulating metabolic processes involved in (1) the promotion of supply of precursors for transmitter glutamate, and (2) reestablishment of resting ion distribution following neuronal excitation. The monoamine transmitters stimulate energy production and Na+,K(+)-ATPase activity in astrocytes in a complex manner and, in so doing, facilitate their role in ion regulation. However, in contrast to excess K+, they do not enhance the production of astrocytic precursors for neuronal glutamate production. Emphasis is placed on possible profound differences in metabolic effects on excitatory and inhibitory neurotransmission and on the importance of stimulation of glycolytic metabolism in astrocytes versus oxidative metabolism in neurons.
Collapse
Affiliation(s)
- R Huang
- Department of Pharmacology, University of Saskatchewan, Saskatoon, Canada
| | | | | | | | | | | |
Collapse
|
369
|
Peng L, Hertz L. Potassium-induced stimulation of oxidative metabolism of glucose in cultures of intact cerebellar granule cells but not in corresponding cells with dendritic degeneration. Brain Res 1993; 629:331-4. [PMID: 8111636 DOI: 10.1016/0006-8993(93)91341-o] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Production of 14CO2 from uniformly labelled glucose was measured in conventional cultures of mouse cerebellar granule cells (a glutamatergic cell type) and in corresponding cultures which had been grown in such a manner that they showed massive degeneration of dendrites, but were otherwise morphologically normal. Both kind of cultures were studied during exposure to either a physiological potassium concentration (5 mM) or an elevated extracellular potassium concentration. During exposure to the normal extracellular potassium concentration, the rate of CO2 production in the two types of culture was identical. In the conventional granule cell cultures, the CO2 production showed a rectilinear increase as a function of the extracellular potassium concentration from 5-100 mM; this stimulation was abolished by ouabain, a specific inhibitor of Na+,K(+)-ATPase. In granule cells showing dendritic degeneration, CO2 production increased only slightly at extracellular potassium concentrations of 25-100 mM. These findings suggest that the metabolic stimulation in morphologically intact cells may be the result of a depolarization-induced sodium uptake, which has a mainly or exclusively dendritic localization, and secondarily leads to a stimulation of the Na+,K(+)-ATPase at its intracellular sodium-sensitive site.
Collapse
Affiliation(s)
- L Peng
- Department of Pharmacology, University of Saskatchewan, Saskatoon, Canada
| | | |
Collapse
|
370
|
Dudarev SL, Peng L, Whelan MJ. Correlations in space and time and dynamical diffraction of high-energy electrons by crystals. Phys Rev B Condens Matter 1993; 48:13408-13429. [PMID: 10007735 DOI: 10.1103/physrevb.48.13408] [Citation(s) in RCA: 64] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
|
371
|
Abstract
Fluoxetine is a recently introduced, widely used antidepressant. It is known as a specific inhibitor of serotonin uptake into synaptosomes but has not previously been recognized as having any direct effect on brain cell serotonin receptors. The present study describes direct effects of fluoxetine on free cytosolic calcium concentration and on breakdown of glycogen in astrocytes (a glial cell type), which are known to express serotonin receptors. Evidence is presented, suggesting that these effects are evoked by an agonist action on the 5-HT1C receptor.
Collapse
Affiliation(s)
- X Zhang
- Department of Pharmacology, University of Saskatchewan, Saskatoon, Canada
| | | | | | | |
Collapse
|
372
|
Peng L, Bradbury JH, Hammer BC, Shaw DC. Comparison of amino acid sequences of the trypsin inhibitors from taro (Colocasia esculenta), giant taro (Alocasia macrorrhiza) and giant swamp taro (Cyrtosperma chamissonis). Biochem Mol Biol Int 1993; 31:73-81. [PMID: 8260948] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
The amino acid sequences of the trypsin inhibitors from taro Colocasia esculenta var. esculenta and giant swamp taro Cyrtosperma chamissonis have been determined and are compared with the protein sequence of the trypsin/chymotrypsin inhibitor from giant taro Alocasia macrorrhiza. Both inhibitors display polymorphism and there is evidence of two components in the giant swamp taro. The positional identity between the proteins is highest at 73-75% for the comparison of the giant taro (GT) with the polymorphic forms of the taro (T) inhibitors and lowest at 56-58% for the pairs of taro and giant swamp taro (GST) proteins. The comparisons show that the inhibitors from T and GT are more related to each other than to GST, which supports their taxonomic classification into different tribes. Location of the P1 site for the trypsin inhibitors of aroids is different from that of other Kunitz-type inhibitors and could be at Leu56.
Collapse
Affiliation(s)
- L Peng
- Division of Botany & Zoology, Australian National University, Canberra
| | | | | | | |
Collapse
|
373
|
Westergaard N, Varming T, Peng L, Sonnewald U, Hertz L, Schousboe A. Uptake, release, and metabolism of alanine in neurons and astrocytes in primary cultures. J Neurosci Res 1993; 35:540-5. [PMID: 8377225 DOI: 10.1002/jnr.490350510] [Citation(s) in RCA: 65] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
The uptake, release, and metabolism of alanine were studied in primary cultures of cerebral cortical neurons or astrocytes and cerebellar granule neurons. All three cell types exhibited a saturable, sodium-dependent uptake of alanine with Km values (microM) of 256 +/- 30, 463 +/- 39, and 292 +/- 39, respectively, and Vmax values (nmol/min/mg) of 15.9 +/- 0.7, 7.9 +/- 0.01, and 17.4 +/- 0.8, respectively. The corresponding values (nmol/min/mg) for the specific activity of alanine aminotransferase were 4.7 +/- 0.4, 17.1 +/- 2.5, and 4.5 +/- 0.9 (all values represent the mean +/- SEM). Release of alanine from the cells was rectilinear with time over a 10 hr period in case of astrocytes (40 nmol/hr/mg) and cerebellar granule neurons (21 nmol/hr/mg). In cortical neurons the release rate declined from an initial value of 19 nmol/hr/mg during the first 3 hr to a value of less than 3 nmol/hr/mg during the subsequent 7 hr of incubation. Metabolism of [14C]alanine to 14CO2 was found to have a lag period of 15 min and subsequently the rate of CO2 production was constant over a 45 min period with a value of 0.5 nmol/min/mg in granule neurons and about 0.3 nmol/min/mg in the other two cell types. Altogether the results show that alanine is preferentially produced in and released from astrocytes and accumulated into both GABAergic cortical neurons and glutamatergic cerebellar granule neurons.
Collapse
Affiliation(s)
- N Westergaard
- PharmaBiotec Research Center, Department of Biological Sciences, Royal Danish School of Pharmacy, Copenhagen
| | | | | | | | | | | |
Collapse
|
374
|
Zhao Z, Peng L. Glutamate effects on calcium homeostasis in cerebellar granule cells in primary cultures grown under depolarizing and nondepolarizing conditions. Synapse 1993; 13:315-21. [PMID: 8097597 DOI: 10.1002/syn.890130404] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Cerebellar granule cell cultures are normally grown under partly depolarizing conditions (in a medium with approximately 25 mM K+), but these cultures can also be grown at a normal potassium concentration (5.4 mM K+), although some of their characteristics are altered. In this study, intracellular free calcium concentration and 45Ca uptake were measured in cerebellar granule cell cultures grown at either 25 or 5.4 mM extracellular potassium in the presence of glutamate, and/or some of its subtype-specific agonists and antagonists. Granule cells in cultures grown at 25 mM K+ responded to glutamate, but not to quisqualate, with an increase in free cytosolic calcium concentration and in 45Ca uptake. This increase in free cytosolic calcium concentration was dependent on extracellular calcium and it was antagonized by AP5 and ketamine, NMDA receptor antagonists. In contrast, granule cells in cultures grown at 5.4 mM K+ responded to both glutamate and quisqualate, and these responses were independent of extracellular calcium and not sensitive to AP5 and ketamine. In agreement with this, 45Ca uptake was not affected by glutamate. Neither of the two culture types responded to kainate with an increase in calcium concentration or uptake. These observations indicate that calcium uptake in granule cells in cultures grown at 25 mM K+ reflect NMDA activation of calcium influx, whereas the cells in cultures grown at 5 mM K+ increase cytosolic calcium concentration on account of intracellular release of bound calcium, caused by activation of the metabotropic receptor.(ABSTRACT TRUNCATED AT 250 WORDS)
Collapse
Affiliation(s)
- Z Zhao
- Department of Pharmacology, University of Saskatchewan, Saskatoon, Canada
| | | |
Collapse
|
375
|
Peng L, Wang X. Lymphocyte B and T cell subsets in peripheral blood from patients with asbestosis. Br J Ind Med 1993; 50:183-184. [PMID: 8382078 PMCID: PMC1061258 DOI: 10.1136/oem.50.2.183] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
Peripheral blood lymphocytes were analysed by indirect staphylococcus protein A (SPA) rosette assay using monoclonal antibodies that identify B cells, total T cells (OKT3+), helper-inducer T cells (OKT4+), and suppressor-cytotoxic T cells (OKT8+). The purpose of this investigation was to determine the characteristics of lymphocyte B and T subsets in peripheral blood, and the relation of the changes to radiographic abnormalities in workers exposed to asbestos.
Collapse
Affiliation(s)
- L Peng
- Department of Occupational Medicine, Chongqing Medical University, China
| | | |
Collapse
|
376
|
Peng L, Hertz L, Huang R, Sonnewald U, Petersen SB, Westergaard N, Larsson O, Schousboe A. Utilization of glutamine and of TCA cycle constituents as precursors for transmitter glutamate and GABA. Dev Neurosci 1993; 15:367-77. [PMID: 7805591 DOI: 10.1159/000111357] [Citation(s) in RCA: 93] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
In the present review evidence is presented that (1) glutamine synthesis in astrocytes is essential for synthesis of GABA in neurons; (2) alpha-ketoglutarate in the presence of alanine (as an amino group donor) can replace glutamine as a precursor for synthesis of transmitter glutamate, but maybe not as a precursor for transmitter GABA; (3) differences exist in the intraneuronal metabolic pathways for utilization of alpha-ketoglutarate plus alanine and of glutamine, and (4) alanine also functions as a substrate for oxidative metabolism in glutamatergic neurons. It should be emphasized that the supply of precursors for transmitter glutamate and GABA in glutamatergic and GABAergic neurons depends on metabolic processes in astrocytes regardless whether glutamine or alpha-ketoglutarate plus L-alanine function as the transmitter precursors. The key reason that an interaction with astrocytes is essential is that both pyruvate carboxylase, the major enzyme in the brain for net synthesis of tricarboxylic acid cycle intermediates, and glutamine synthetase, the enzyme forming glutamine from glutamate, are specifically located in astrocytes, but not in neurons.
Collapse
Affiliation(s)
- L Peng
- Department of Pharmacology, University of Saskatchewan, Saskatoon, Canada
| | | | | | | | | | | | | | | |
Collapse
|
377
|
Schousboe A, Westergaard N, Sonnewald U, Petersen SB, Huang R, Peng L, Hertz L. Glutamate and glutamine metabolism and compartmentation in astrocytes. Dev Neurosci 1993; 15:359-66. [PMID: 7805590 DOI: 10.1159/000111356] [Citation(s) in RCA: 137] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
Metabolism of glutamate and glutamine in cultured mouse cerebral cortical astrocytes has been investigated using either radioactively labelled (14C) amino acids or 13C-labelled amino acids combined with NMR spectroscopy of cell extracts and lyophilyzed incubation media. Using [U-13C]glutamate it has been shown that in astrocytes exogenously supplied glutamate is primarily (70%) metabolized oxidatively through the tricarboxylic acid (TCA) cycle and to a lesser extent (30%) directly to glutamine. Glutamate metabolized in the TCA cycle is to a large extent recovered as lactate showing that the astrocyte-specific enzyme, malic enzyme is functionally active. Incubation with [U-14C]glutamine led to a higher specific radioactivity in glutamate than in glutamine. It could also be shown that glutamate and glutamine were metabolized differently to aspartate and alanine. These results taken together strongly suggest that glutamate/glutamine metabolism in astrocytes is compartmentalized and a model with multiple cytoplasmic and mitochondrial compartments of these amino acids is proposed.
Collapse
Affiliation(s)
- A Schousboe
- Department of Biological Sciences, Royal Danish School of Pharmacy, Copenhagen
| | | | | | | | | | | | | |
Collapse
|
378
|
Hertz L, Code WE, Huang R, Juurlink BH, Peng L, Sochocka E, Zhong Z, Yu AC. Glutamate and anoxic-ischemic cell death in neurons and astrocytes. Clin Neuropharmacol 1992; 15 Suppl 1 Pt A:126A-127A. [PMID: 1354021 DOI: 10.1097/00002826-199201001-00068] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Affiliation(s)
- L Hertz
- Dept. of Pharmacology, University of Saskatchewan, Saskatoon, Canada
| | | | | | | | | | | | | | | |
Collapse
|
379
|
Abstract
Evidence is accumulating that interactions between different cell types are of paramount importance for CNS function, for example, release of the excitatory transmitter glutamate from neurons and its preferential uptake into astrocytes. Some information is also available about energy metabolism in different cell types, or more often in models of different cell types (e.g., synaptosomes, cultured neurons, cultured astrocytes). In this review an attempt is made not only to correlate information obtained with different cell models but also to integrate this information with in vivo data, with histochemical observations, and with results obtained using brain slices. The emerging patterns indicate that neurons, synaptosomes, and astrocytes are all capable of complete glycolysis and oxidation of glucose. Elevated extracellular concentrations of potassium, known to occur in vivo, enhance energy metabolism by mechanisms that differ between neurons and astrocytes and to a large extent serve to reaccumulate extracellular potassium ions into adjacent cells. Monoaminergic agonists also stimulate energy metabolism, but mainly or exclusively in astrocytes. Profound differences are found between the effects of excess potassium and of aminergic transmitters, suggesting that high potassium concentrations enhance neuronal-astrocytic interactions, whereas the monoamines may tend to dissociate metabolic events in neurons and in astrocytes.
Collapse
Affiliation(s)
- L Hertz
- Department of Pharmacology, University of Saskatchewan, Saskatoon, Canada
| | | |
Collapse
|
380
|
Peng L, Hertz L. Long-lasting abolishment of noradrenaline induced stimulation of oxidative metabolism after chronic exposure of developing mouse astrocytes to cocaine. Brain Res 1992; 581:334-8. [PMID: 1356581 DOI: 10.1016/0006-8993(92)90728-r] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Rate of 14CO2 production from [l-14C]glutamate was determined as a measurement of oxidative metabolism in developing primary cultures of astrocytes, obtained from the neonatal mouse brain and grown in the absence (control) or presence of cocaine. From the age of 3 days, the drug-exposed cultures were grown in a tissue culture medium containing either 1 or 3 microM cocaine. After 2 months of chronic exposure to cocaine the metabolic rate showed an increase of approximately 50%, but there was a long lag period (several weeks) before this response occurred. In contrast to a marked stimulation of CO2 production when noradrenaline was added to untreated cultures of the same age, there was no similar effect of noradrenaline on cultures treated with cocaine. After exposure to cocaine for 21 days (24-day-old cultures), both the enhanced CO2 production and the abolishment of the normal response to noradrenaline persisted during 'withdrawal' (cessation of drug exposure) throughout the total period investigated, i.e. to an age of 60 days (corresponding to a withdrawal period of 36 days). The correlation of these findings with in vivo data is discussed.
Collapse
Affiliation(s)
- L Peng
- Department of Pharmacology, University of Saskatchewan, Saskatoon, Canada
| | | |
Collapse
|
381
|
Peter K, Lindsley D, Peng L, Gallant JA. Context rules of rightward overlapping reading. New Biol 1992; 4:520-6. [PMID: 1515416] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
We have investigated the mechanism and sequence context rules governing ribosome frameshifting promoted by aminoacyl-tRNA limitation. In the case of one shifty sequence, frameshifting promoted by lysyl-tRNA limitation occurs at the sequence AAG C and is due to rightward movement of the ribosome so as to read the AGC triplet overlapping the hungry codon from the right. The frequency of this event is unaffected by sequence elements more than three bases to the left (upstream) or two bases to the right (downstream) of the hungry codon, and only slightly affected by the identity of the base two bases to the right. It is strongly affected by the base immediately to the right of the hungry codon, which becomes the wobble base of the shifted triplet; and by the third base of the hungry codon, even though the two synonyms (AAG and AAA) call for the same aminoacyl-tRNA; and by the identity of the base immediately to the left of the hungry codon. The latter result suggests that the aminoacyl-tRNA in the P site affects the maintenance of reading frame at the adjacent A site of the ribosome. However, the DNA sequence makes it seem unlikely that the P-site tRNA shifts to the right in concert with the A-site tRNA, a mechanism that can account for leftward frameshifting (in the opposite direction) in retroviral translation. The specificity of sequence determinants of leftwing versus rightwing frameshifting is discussed.
Collapse
Affiliation(s)
- K Peter
- Department of Genetics, University of Washington, Seattle 98195
| | | | | | | |
Collapse
|
382
|
Hertz L, Peng L. Effects of monoamine transmitters on neurons and astrocytes: correlation between energy metabolism and intracellular messengers. Prog Brain Res 1992; 94:283-301. [PMID: 1283791 DOI: 10.1016/s0079-6123(08)61758-6] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Affiliation(s)
- L Hertz
- Department of Pharmacology, University of Saskatchewan, Saskatoon, Canada
| | | |
Collapse
|
383
|
Abstract
Indomethacin inhibits bone formation when treatment is initiated before the implantation of demineralized bone matrix (DBM). For the inhibition of bone induction to occur, indomethacin treatment had to be initiated 6 h or more before implantation of DBM. Initiating the drug treatment at or after the time of DBM implantation had no effects on the amounts of new bone formed. The inhibition by indomethacin is dose related over a range between 0.04 and 4 mg/kg body weight. Recovered day-1 DBM implants, transplanted into indomethacin pre- and posttreated syngeneic rats, formed bone at the same rate as controls did. However, recovered day-1 DBM implants lyophilized before transplantation showed decreased bone formation but significant dystrophic calcification as judged by a lower alkaline phosphatase activity and an elevated calcium content.
Collapse
Affiliation(s)
- P E DiCesare
- Bone and Connective Tissue Biochemistry Research Laboratory, University of Southern California School of Medicine, Orthopaedic Hospital, Los Angeles 90007
| | | | | | | | | |
Collapse
|
384
|
Abstract
Collagen composition and cross-linking in human keloid and normal skin tissues were analyzed biochemically. CNBr peptides were separated by 2-dimensional (2-D) mapping and high performance liquid chromatography (HPLC). The amounts of type I and type III collagen was quantified by 2-D scanning densitometry of fluorographs of 2-D maps derived from samples radioactively labelled in vitro by [3H]-NaBH4 in dimethylformamide. Keloid tissues contained 31.6 +/- 2.2 percent type III collagen as compared to 21.4 +/- 2.7 percent type III present in normal human skin dermis. HPLC profiles of CNBr peptides showed that approximately 5 percent of the high molecular weight material in keloids is mercaptoethanol reducible, compared to insignificant amounts in normal skin. 2-D maps derived from CNBr peptides of keloid collagen demonstrated thiol reduction sensitive alpha 1(III)-CB9 dimer as well as 24,000- and 32,000-dalton CNBr peptides, which were not mercaptoethanol reduction sensitive in normal skin due to cross-linking via the lysyl oxidase pathway. Also, a group of 20,000- to 25,000-dalton CNBr peptides, in the alpha 1(I)-CB6 cross-linking region were prominent in keloid tissues.
Collapse
|
385
|
Wood LL, Cobbs CS, Lantz L, Peng L, Calton GJ. Immobilization of enzymes with polyaziridines. J Biotechnol 1990; 13:305-14. [PMID: 1366362 DOI: 10.1016/0168-1656(90)90078-p] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
A novel method of enzyme immobilization using a low molecular weight prepolymer of tri-functional aziridines which can immobilize enzymes both by covalent attachment and entrapment within a gel matrix is described. The enzymes are immobilized on a solid support and exhibit an excellent retention of enzymatic activity. The immobilization procedure is essentially a single step process which can be easily performed at room temperature or 4 degrees C in either aqueous solution or in an inert organic solvent. The polyaziridines used in the immobilization are nontoxic, available in bulk at low cost and completely miscible with water and many organic solvents, thus providing one of the most satisfactory methods of immobilization available.
Collapse
Affiliation(s)
- L L Wood
- Rhone Poulenc Research Center, Savage, MD 20763
| | | | | | | | | |
Collapse
|
386
|
East TD, Wortelboer PJ, van Ark E, Bloem FH, Peng L, Pace NL, Crapo RO, Drews D, Clemmer TP. Automated sulfur hexafluoride washout functional residual capacity measurement system for any mode of mechanical ventilation as well as spontaneous respiration. Crit Care Med 1990; 18:84-91. [PMID: 2293972 DOI: 10.1097/00003246-199001000-00018] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
A new sulfur hexafluoride (SF6) washout functional residual capacity (FRC) measurement system has been developed which will work with any mode of mechanical ventilation, as well as with spontaneous respiration. This system was evaluated in three different human studies. In the first two studies, the accuracy of the system was compared with He dilution and body plethysmography in 12 spontaneously breathing normal volunteers and in 12 spontaneously breathing chronic obstructive pulmonary disease (COPD) patients. In the third study, the reproducibility and efficacy of using the system in the ICU was tested in 12 adult respiratory distress syndrome (ARDS) patients who were mechanically ventilated with PEEP. In the normal volunteers, there was no significant difference between the three measurement techniques. In the COPD group, there was an overall significant difference between measurement techniques (F[2,28] = 17.18, p less than .0001) and the rank of the magnitude of the FRC measurements from lowest to highest was SF6 washout, He dilution, and body plethysmography. There was a significant difference in accuracy between the COPD and normal volunteer groups (F[2,28] = 12.24, p less than .0002). There were a total of 1,227 FRC measurements made on the 12 ARDS patients. The number of FRC measurements per patient was 102 +/- 13 (SEM). The "stable" periods were 14 +/- 2 h long and ranged from 60 min to 63.5 h. The reproducibility for all 12 patients was 188 +/- 17 ml or 11.7 +/- 0.7%. This automated SF6 washout system should make routine FRC measurements in patients who are being mechanically ventilated simple and easy to do.(ABSTRACT TRUNCATED AT 250 WORDS)
Collapse
Affiliation(s)
- T D East
- Department of Anesthesiology, University of Utah Medical Center, Salt Lake City 84132
| | | | | | | | | | | | | | | | | |
Collapse
|
387
|
Hertz L, Peng L, Hertz E, Juurlink BH, Yu PH. Development of monoamine oxidase activity and monoamine effects on glutamate release in cerebellar neurons and astrocytes. Neurochem Res 1989; 14:1039-46. [PMID: 2575232 DOI: 10.1007/bf00965940] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Activities of monoamine oxidase (MAO) A and B were measured during the first month of postnatal development in mouse cerebellum and in primary cultures of either cerebellar granule cells or cerebellar astrocytes, derived from 7-day-old cerebella. In addition, effects of the two monoamines, serotonin (a MAO A substrate) and phenylethylamine (a MAO B substrate) on the release of glutamate under resting conditions and in a transmitter related fashion (i.e., potassium-induced, calcium-dependent glutamate release) were studied during the same period. Both MAO A and MAO B activities increased during in vivo development (beginning around postnatal day 14) and in cultured astrocytes (during a comparable time period and to a similar extent), but remained constant at a low level in granule cells. In 4-day-old cerebellar granule cell cultures there was no potassium-induced glutamate release but serotonin as well as phenylethylamine reduced the release in both the presence and absence of excess potassium. In 8- and 12-day-old granule cell cultures and in 8- and 18-day old astrocyte cultures there was a pronounced glutamate release during superfusion with 50 mM K+. In both neurons and astrocytes this response was inhibited by 1 nM of either serotonin or phenylethylamine. In the astrocytes the inhibition was followed by an increased release of glutamate in both the presence and absence of the high potassium concentration, whereas the 8-day-old neurons showed only a slight increase in glutamate release after the withdrawal of the monoamine and only in the absence of excess potassium. The response was almost identical in 8- and 18-day-old astrocytes in spite of the marked difference in MAO activities.
Collapse
Affiliation(s)
- L Hertz
- Department of Pharmacology, University of Saskatchewan, Saskatoon, Canada
| | | | | | | | | |
Collapse
|
388
|
Peng L, Suzuki K. Ultrastructural study of neurons in metachromatic leukodystrophy. Clin Neuropathol 1987; 6:224-30. [PMID: 2826059] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
Neuronal inclusions were investigated with the electron microscope in several regions of the central nervous system (CNS) of a patient with late infantile metachromatic leukodystrophy (MLD). The neuronal perikarya of the spinal anterior horn cells and the neurons in the globus pallidus were distended with concentrically arranged lamellar inclusions which closely resembled membranous cytoplasmic bodies (MCB) of gangliosidoses. Large pyramidal neurons in the motor cortex also contained a few smaller MCB-like inclusions. These neuronal inclusions were relatively uniform in size and in morphology in contrast to pleomorphic inclusions in glial cells in MLD. Membrane-bound vacuoles containing moderately electron-dense granular materials or electron-dense aggregates were found in some pyramidal neurons in the Ammon's horn and cerebellar Purkinje cells. These changes were interpreted to represent the reaction of these neurons to subtle cellular injury which may or may not be related to metabolic derrangement in MLD.
Collapse
Affiliation(s)
- L Peng
- Department of Pathology (Neuropathology), Albert Einstein College of Medicine, Bronx, NY
| | | |
Collapse
|
389
|
Hu YC, Li GY, Peng L, Deng YM. Sister chromatid exchanges in lymphocytes of early cases of nasopharyngeal carcinoma and in 100 healthy subjects. Cell Biol Toxicol 1987; 3:321-5. [PMID: 3507260 DOI: 10.1007/bf00117868] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Sister chromatid exchange rate was studied in 12 early diagnosed cases of nasopharyngeal carcinoma and in their paired controls. Exchange frequencies were also analyzed in 100 healthy subjects distributed in four regions of Hunan Province and correlated to nationality, age and sex. The incidence of sister chromatid exchange was significantly higher in the cancer patients than in the normal controls. No correlation was found between the frequency of sister chromatid exchange and region, nationality, age or sex.
Collapse
Affiliation(s)
- Y C Hu
- Cancer Research Laboratory, Hunan Medical College, Changsha, People's Republic of China
| | | | | | | |
Collapse
|
390
|
Yang YD, Zhang LS, Chen WJ, Peng L, Shen JY, Wu XR, Wu ZB. [Morphological studies of norethisterone oxime effect on ovary in rabbits and rats]. J Tongji Med Univ 1987; 7:95-102. [PMID: 3656491 DOI: 10.1007/bf02888169] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
|
391
|
Abstract
The effect of borohydride reducing reagents on monoclonal and polyclonal antibodies was examined by enzyme-linked immunosorbent assay (ELISA). Each antibody showed different stability characteristics to the reducing reagents. Sodium cyanoborohydride was at least five times milder toward immunological activity than sodium borohydride, however, sodium cyanoborohydride with a catalytic amount of metal ion (Zn2+ or Al3+) can be as harsh as sodium borohydride. Activated hydrophobic borohydrides, 9BBN-pyridine, did not have any advantages in respect to the stabilities of antibodies. Antibodies to be used for immunosorbent purification must be evaluated individually to determine whether their structure is stable to immobilization reagents and conditions prior to their linkage to the column support.
Collapse
|
392
|
Overberger CG, Peng L. Synthesis of poly(ethylene glycol methyl ether)-b-poly(ethylenimine) and its derivatives containing thymine and amino acids as pendants. ACTA ACUST UNITED AC 1986. [DOI: 10.1002/pola.1986.080241109] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
|
393
|
Wang LJ, Huang GJ, Zhang DW, Zhang RG, Xu PZ, Peng L, He J. [Experience in the surgical treatment of 748 patients with lung cancer]. Zhonghua Zhong Liu Za Zhi 1986; 8:283-6. [PMID: 3757745] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
A series of 748 patients with lung cancer as treated by surgery from 1961 to 1984 is reported. Regular lobectomy was done in 445 (74%) patients, bronchoplastic lobectomy in 67 (11.2%), segmental or wedge excision in 15 (2.5%) and pneumonectomy in 74 (12.3%) in which the ratio of left to right pneumonectomy was 2.9:1. Overall resection rate was 80.4% (601/748) and resection mortality was 1.2% (7/601) (death within 30 days of operation). Overall 5 year survival rate was 42% (169/402). The 5 year survival rate was 35.3% for pneumonectomy, 54.1% for bronchoplastic lobectomy, 42.3% for regular lobectomy and 16.7% for segmental or wedge excision. In this analysis, emphasis is laid to the therapeutic validity of the different modes of surgery. Statistical data show that only when the indication of different surgical interventions are strictly adhered to and the reasonable procedures are carried out, could better results be obtained. In surgical treatment of lung cancer, it is an important principle to eradicate the tumor and its metastatic foci as thorough as possible and to conserve the respiratory function as much as possible. Regular lobectomy has now become the "standard" and first choice operation. Pneumonectomy should be reserved for the patients with absolute necessity due to the extent of the lesion, adequate cardiopulmonary function and possibility of a permanent cure. Pneumonectomy is substituted by bronchoplastic lobectomy to a certain degree, preserving more of the lung function and improving the living quality after operation and long term results. Extensive practice of this surgical modality is advised.
Collapse
|
394
|
Peng L, Yang YD. Morphological studies on the mechanism of anti-implantative and early-pregnancy-terminative effect by norethisterone oxime in rats. Acta Acad Med Wuhan 1985; 5:178-84. [PMID: 4069500 DOI: 10.1007/bf02911177] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
|
395
|
Peng L. [Comparative ultrastructure of the normal mucosa and the adenocarcinoma cells of the human large intestine]. Zhonghua Zhong Liu Za Zhi 1985; 7:271-3. [PMID: 4085317] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
This paper presents the comparative observation by transmission electron microscopy (TEM) of ten cases of adenocarcinoma of the large intestine and the normal colon mucosa. The ultrastructural features of the carcinoma cells were as follows: The basement membrane was perforated by cytoplasmic projections of the carcinoma cells, extending into the lamina propria. The membrane of the neighbouring cells was quite smooth, the interdigitation appeared sparse and the intercellular space was often dilated. The phenomenon of desmosome separation was found. Therefore, careful observation of the changes in the cell membrane is helpful in the diagnosis of colonic adenocarcinoma.
Collapse
|
396
|
Chen DL, Chen TL, Xu GR, Chen YL, Peng L, Wang H. A study of dynamic development in radiolesion and cell death of eukaryotes after exposure to ionizing radiation--the visualization of the dynamic reaction by means of cytochemical method with lactate dehydrogenase (LDH) as a nuclear marker and radiation-induced nuclear anomalization by an ultramicrostructural manifestation: a dynamic explanation. Sci Sin B 1985; 28:584-98. [PMID: 4023692] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
The present work deals with the radiation effect on adult rats suffering from acute, whole-body irradiation with cobalt-60 gamma rays of dosages 100R and 300R respectively. The morphological alteration of the lymphocytic nucleus and exhibition of cytochemical reaction of LDH in intra- or extra-nuclear region has been observed at the end of predetermined time intervals after irradiation. A close relationship between the percentage of damage of the lymphocytic nucleus and that of positivity of LDH reaction is seen from their variations with time parallel. From technical color microphotographs which exhibit cytochemical reactions, the existence of enzyme LDH in the nucleus so far obscure has been visually recognized. The events happening in enzymic reaction and the leakage of enzyme across the nuclear envelope reflect the dynamic nature. The ultrastructural alteration of nuclear anomalization confirms the dynamic development of inducing radiolesion. The experimental facts inspire us to attempt an explanation of cellular radiolesion and cell death owing to ionization radiation in light of the dynamic concept.
Collapse
|
397
|
|
398
|
Peng L, Cheng J, Sun Z. [The effect of electric stimulation of the brain stem on the skin galvanic reflex]. Sheng Li Xue Bao 1966; 29:26-33. [PMID: 5178709] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
|