301
|
Abstract
Sodium nitroprusside produced a dose-dependent increase in extracellular levels of cGMP in the cerebellar cortex in vivo. This was independent of nitric oxide synthase activity. The metalloporphyrins zinc-protoporphyrin-IX, tin-protoporphyrin-IX and zinc-deuteroporphyrin-IX,2,4-bis glycol prevented the increase in cGMP in the cerebellar cortex produced by sodium nitroprusside. At high doses, tin-protoporphyrin-IX also decreased the basal extracellular levels of cGMP. These drugs had no effect on nitric oxide synthase activity. We conclude that the neuropharmacological effects of metalloporphyrins may result from their direct inhibition of soluble guanylyl cyclase, rather than from an effect on carbon monoxide synthesis.
Collapse
|
302
|
Hara H, Lee MH, Chen H, Luo D, Jimbow K. Role of gene expression and protein synthesis of tyrosinase, TRP-1, lamp-1, and CD63 in UVB-induced melanogenesis in human melanomas. J Invest Dermatol 1994; 102:495-500. [PMID: 8151127 DOI: 10.1111/1523-1747.ep12373136] [Citation(s) in RCA: 27] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Using melanotic cells (SK-MEL-23 and G361) and amelanotic cells (C32 and SK-MEL-24) of human melanoma, this study examined whether UV-B irradiation has a direct stimulatory effect on the expression of genes involved in melanogenesis. Our initial screening of methylthiazol tetrazolium (MTT)-formazan formation assay indicated a low dose of ultraviolet (UV)-B irradiation, 2.5 and 5.0 mJ/cm2, can metabolically stimulate these cells. Repeated exposure of UV-B at 5.0 mJ/cm2 for seven consecutive days resulted in increased tyrosinase activity and melanin synthesis in SK-MEL-23 and G361 cells, but not in C32 and SK-MEL-24 cells. On reverse-transcription-polymerase chain reaction and immunoprecipitation studies, the two melanotic cell lines exhibited upregulated expression of mRNA and antigenic epitopes of tyrosinase, tyrosinase-related protein (TRP-1; gp75/HMSA-5), and lysosomal membrane associated protein (Lamp-1). The amelanotic cell line, C32, expressed the tyrosinase gene and protein constitutively but revealed no active tyrosinase or melanin synthesis even after UV-B exposure. Another amelanotic cell line, SK-MEL-24, exhibited no expression of tyrosinase gene and protein before and after UV-B exposure and, therefore, no melanin synthesis. Both C32 and SK-MEL-24 showed no gene or protein expression of TRP-1 before or after UV exposure, but upregulation of the Lamp-1 gene and protein expressions after exposure. We conclude that tyrosinase is the key enzyme responsible for UVB-induced melanogenesis. Both TRP-1 and Lamp-1 act together in melanogenesis, TRP-1 being essential and necessary. There is no change in the expression of CD63 lysosomal membrane protein at either the mRNA or protein level.
Collapse
|
303
|
Tang XB, Hobom G, Luo D. Ribozyme mediated destruction of influenza A virus in vitro and in vivo. J Med Virol 1994; 42:385-95. [PMID: 8046429 DOI: 10.1002/jmv.1890420411] [Citation(s) in RCA: 46] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Short catalytic RNAs with inherent, specific endoribonuclease activity, called ribozymes, have recently been shown to exist in nature. According to the structural models artificial ribozymes have been designed that can potentially hydrolyse any chosen target RNA sequence in trans at a specific site. We have constructed and characterized in vitro hammerhead and hairpin ribozymes designed to cleave viral RNA segment 5 of influenza A virus. Both ribozymes were functional under optimal in vitro conditions, but quantitative measurements indicate that the hammerhead ribozyme is considerably more efficient at this target site than the hairpin ribozyme. Mg2+ dependent hammerhead ribozyme-mediated cleavage reactions were enhanced at higher temperature and in presence of spermidine, but catalytic activities were retained also in cellular extract S-100 or nuclear extracts at physiological temperatures. Recombinant plasmids derived from transfection vector pSV2-neo were engineered to allow the expression of specific ribozymes under the control of SV40 early promoter or SV40 early+ late promoters. These plasmids were introduced by transfection into COS cells, and their expression and enzymatic activities were analyzed in stable cell lines after selection of neomycin-resistance. Several permanent ribozyme-expressing clones were established and characterized: ribozyme coding DNA sequences and synthesis of ribozyme RNA molecules in the transfected cells were determined and monitored by polymerase chain reactions. It was found that the highest levels (up to 70-80%) of resistance to influenza A virus strain X-31 super-infection was observed in COS cells transfected with plasmids containing SV40 early or SV40 early+late promoters coinciding with relatively high and constitutive rates of ribozyme expression. These results suggest the feasibility of developing ribozymes designed against influenza virus to achieve therapeutic value.
Collapse
|
304
|
Zhou ZD, Chen XR, Luo D. [Laparoscopic cholecystectomy performed in 235 cases of cholecystitis with impacted gallstones]. ZHONGHUA WAI KE ZA ZHI [CHINESE JOURNAL OF SURGERY] 1994; 32:227-9. [PMID: 7842926] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
During the past 2 years, 235 cases of cholecystitis with impacted gallstones were treated with laparoscopic technique. There were 221 chronic cases and 14 acute cases accounting altogether for 15.19% of a total of 1475 patients undergoing laparoscopic cholecystectomy during the same period. As a result, 9 of these patients were converted to open surgery. Severe adhesion around the gallbladder or/and in the Calot triangle in 7, acute impacted gallstone, gallbladder necrosis along with obscure anatomy in the calot triangle in 1, and gallstone impacted at the junction of the common hepatic and cystic duct in 1 were observed. Conversion rate was 3.8%. Postoperative bile leakage developed in 2 cases and healed spontaneously. There were no intraperitoneal sepsis and perioperative death in our patients. The diagnosis, classification, and management for acute or chronic impacted gallstone are discussed.
Collapse
|
305
|
Pu Y, Yamamoto F, Igimi H, Shilpakar SK, Kojima T, Yamamoto S, Luo D. A comparative study usefulness of magnetic resonance imaging in the diagnosis of acute cholecystitis. J Gastroenterol 1994; 29:192-8. [PMID: 8012508 DOI: 10.1007/bf02358682] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
The utility of magnetic resonance imaging (MRI) in the diagnosis of acute cholecystitis was evaluated in 72 consecutive individuals (5 healthy, 13 with chronic cholecystitis and silent gallbladder stones, 43 without biliary or diffuse liver disease, and 11 with acute cholecystitis and gallbladder stones) with a 0.5-T superconducting unit. On the T1-weighted (500/20) and less T1-weighted axial spin-echo images (620/25), the liver/gallbladder signal intensity ratio (mean +/- SD) was 2.5 +/- 0.51 (n = 5) and 1.8 +/- 0.29 (n = 8) in acute cholecystitis; 0.9 +/- 0.42 (n = 6) and 1.0 +/- 0.29 (n = 9) in chronic cholecystitis; and 0.9 +/- 0.14 (n = 5) and 0.8 +/- 0.19 (n = 43) in normal gallbladder, respectively. Our results indicate that the liver/gallbladder signal intensity ratio on the T1-weighted image may be a simple and reliable indicator for the diagnosis of acute cholecystitis; we suggest further investigation to confirm these results.
Collapse
|
306
|
Claycamp HG, Luo D. Plutonium-catalyzed oxidative DNA damage in the absence of significant alpha-particle decay. Radiat Res 1994; 137:114-7. [PMID: 8265780] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Plutonium is considered to be a carcinogen because it emits alpha particles that may result in the irradiation of stem cell population. In the present study we show that plutonium can also catalyze reactions that induce hydroxyl radicals in the absence of significant alpha-particle irradiation. Using the low specific activity isotope, 242Pu, experiments were performed under conditions in which chemical generation of hydroxyl radicals was expected to exceed the radiolytic generation by one hundred thousand-fold. The results showed that markers of oxidative DNA base damage, thymine glycol and 8-oxoguanine could be induced from plutonium-catalyzed reactions of hydrogen peroxide and ascorbate similarly to those occurring in the presence of iron catalysts. Plutonium-242, as a neutralized nitrate in phosphate buffer, was 4.8-fold more efficient than iron at catalyzing the oxidation of ascorbate at pH 7. The results suggest that plutonium complexes could participate in reactions at pH 7 that induce oxidative stress--a significant tumor-promoting factor in generally accepted models of carcinogenesis.
Collapse
|
307
|
Luo D, Leung E, Vincent SR. Nitric oxide-dependent efflux of cGMP in rat cerebellar cortex: an in vivo microdialysis study. J Neurosci 1994; 14:263-71. [PMID: 7506765 PMCID: PMC6576854] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
The stimulation of excitatory amino acid receptors in the cerebellar cortex results in the Ca2+/calmodulin-dependent activation of nitric oxide synthase. This leads to an increase in tissue levels of cGMP following the interaction of nitric oxide with soluble guanylyl cyclase. The cerebellar cortex has the highest levels of nitric oxide synthase and cGMP in the brain; however, the levels of guanylyl cyclase and cGMP-phosphodiesterase are remarkably low. Thus, the mechanisms regulating cGMP levels in cerebellar cells are unclear. One report has noted that cGMP can be released from cerebellar slices. We have therefore used intracerebellar microdialysis in awake, freely moving rats to test the hypothesis that activation of nitric oxide synthase in the cerebellar cortex results in the release of cGMP. Climbing fibers, which release excitatory amino acids in the cerebellum, were activated with systemic harmaline. This resulted in an immediate increase in extracellular cGMP, which was blocked by TTX or the removal of extracellular Ca2+, and attenuated by prior lesion of the climbing fibers. Blockade of N-type calcium channels with omega-conotoxin also antagonized the harmaline-induced increase. In contrast, blockade of L-type calcium channels, or inhibition of anion transport with probenecid or bromosulfophthalein, potentiated the increase in cGMP seen in response to harmaline. Inhibitors of nitric oxide synthase or guanylyl cyclase prevented the harmaline-induced increase in extracellular cGMP, while phosphodiesterase inhibitors potentiated the increase. Local application of the NMDA antagonist 2-amino-5-phosphonopentanoic acid or the AMPA receptor antagonist 6-cyano-7-nitroquinoxaline-2,3-dione attenuated the effect of harmaline.(ABSTRACT TRUNCATED AT 250 WORDS)
Collapse
|
308
|
Luo D, Knezevich S, Vincent SR. N-methyl-D-aspartate-induced nitric oxide release: an in vivo microdialysis study. Neuroscience 1993; 57:897-900. [PMID: 7508585 DOI: 10.1016/0306-4522(93)90035-e] [Citation(s) in RCA: 131] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Increasing evidence indicates that nitric oxide acts as an intercellular signal transduction molecule in the nervous system. In particular, in vitro studies have demonstrated that nitric oxide is produced in the cerebellar cortex and is responsible for the increases in cyclic GMP seen in response to glutamate receptor activation. In this study, we have combined the technique of intracerebellar microdialysis with a sensitive assay for nitric oxide oxidation products nitrate and nitrite, to assess nitric oxide release directly in awake, freely moving animals. We have found that infusion of N-methyl-D-aspartate via the microdialysis probe results in a dose-dependent increase in cerebellar nitric oxide release. This increase was prevented by prior administration of an N-methyl-D-aspartate receptor antagonist, or the nitric oxide synthase inhibitor NG-nitroarginine. Both these pretreatments also reduced the basal extracellular nitrite and nitrate levels, suggesting that there is a tonic glutamate-induced nitric oxide production in the cerebellum of awake, freely moving animals. These results provide direct evidence for nitric oxide release in response to N-methyl-D-aspartate receptor activation in the adult cerebellar cortex, in vivo. This new approach, coupling microdialysis with the azo dye detection method of Griess, should thus prove useful for the in vivo study of nitric oxide release from various brain regions in response to pharmacological, physiological or behavioral manipulations.
Collapse
|
309
|
Dakour J, Vinayagamoorthy T, Jimbow K, Chen H, Luo D, Dixon W, Munoz V. Identification of a cDNA coding for a Ca(2+)-binding phosphoprotein (p90), calnexin, on melanosomes in normal and malignant human melanocytes. Exp Cell Res 1993; 209:288-300. [PMID: 8262146 DOI: 10.1006/excr.1993.1313] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
In order to have a proper biosynthesis and secretion of the melanin-pigment granules (melanosomes) the melanocyte may require a melanosome-associated molecule that provides a signal for assembly and organization of melanogenic enzymes and proteins within the compartment of melanosomes. This study reports the presence of a Ca(2+)-binding phosphoprotein, p90, which can be engaged in such melanogenic function, located on the melanosomal membrane of human melanocytes. A human melanoma cDNA expression library in lambda Zap II was screened with a rabbit polyclonal antibody raised against human melanosomes isolated from cultured human melanoma cells, SK MEL 23. A cDNA encoding a melanosomal protein, M(r) 90 kDa, was identified through this immunoscreening. A partial sequencing of nucleotides (822 bp from the N-terminal domain) of this clone (3.8 kb) and predicted amino acids showed more than 90% homology with dog calnexin, a previously reported endoplasmic reticulum (ER) transmembrane protein. A fusion protein of this p90 with beta-galactosidase expressed in Escherichia coli revealed both the immuno-cross-reactivity with anti-dog calnexin and anti-human melanosome antibodies and the Ca(2+)-binding property. Upon immunohistochemistry, the anti-dog calnexin antibody revealed the positive immunoreactivities with both normal and malignant human melanocytes, showing a much higher expression of antigenic epitope than nonmelanocytic human cells. The laser scanning confocal immunofluorescence, using an antibody against a human melanosome-specific antigen (HMSA-5), and immunoelectron microscopy, using immunogold, confirmed the major localization of anti-dog calnexin antibody epitope on the melanosomes and ER.
Collapse
|
310
|
Deng X, Luo D, Li Y, Lian S. [Changes in TXB2/6-keto-PGF1 alpha ratio and their relation to blood lipids of Type A behavioral patterns]. HUA XI YI KE DA XUE XUE BAO = JOURNAL OF WEST CHINA UNIVERSITY OF MEDICAL SCIENCES = HUAXI YIKE DAXUE XUEBAO 1993; 24:414-7. [PMID: 8150445] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
To study the pathophysiological relation between Type A behavioral pattern and coronary artery disease, we analyzed the Type A behavioral pattern, serum triglycerides (TG), cholesterol (TC), high density lipoprotein cholesterol (HDLc), and TXB2, 6-keto-PGF1 alpha in 60 patients with coronary artery disease and 60 age-sex-matched healthy subjects. All of them had normal blood pressure. The results showed Type A behavioral pattern was more prevalent than Type B behavioral pattern in coronary artery diseased patients and the reverse was true in the controlled subjects (P < 0.025); TG, TC and TXB2/6-keto-PGF1 alpha ratio increased significantly in Type A behavioral pattern compared with Type B behavioral patients, but HDLc/(TC+TG) and the level of HDLc decreased significantly in the Type A behavioral pattern than in the Type B behavioral pattern (P < 0.05). The TG, TC increased significantly and 6-keto-PGF1 alpha HDLc decreased significantly in the coronary artery diseased patients (P < 0.05). However, the ratio of TXB2/6-keto-PGF1 alpha was inversely related to HDLc/(TC+TG) among the coronary artery diseased patients. The results of this cross-sectional study suggest that coronary artery disease is associated with Type A behavioral pattern through the metabolism of lipids and prostaglandins in various ways.
Collapse
|
311
|
Dakour J, Jimbow K, Vinayagamoorthy T, Luo D, Chen H. Characterization of melanosome-associated proteins by establishment of monoclonal antibodies and immunoscreening of a melanoma cDNA library through an anti-melanosome antibody. Melanoma Res 1993; 3:331-6. [PMID: 8292889 DOI: 10.1097/00008390-199310000-00005] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Monoclonal antibodies against melanosomal components (human melanosome specific antigens; HMSAs) have been developed in our laboratory. HMSA-1-4 recognizes structural matrix proteins of melanosomes. HMSA-5 is identical to TRP-1, equivalent to the b (brown) locus of murine melanocytes and expressed in early stages of melanosomal maturation. HMSA-6 is a protein associated with melanosomes but its role is still unclarified, and HMSA-7 is identical to the lysosomal protein CD63. We have also recently identified p90 calnexin-like, Ca(2+)-binding protein p97 melanotransferrin, and p64 beta-D-galactosidase-like protein associated with melanosomes through immunological screening of our melanocytes (melanoma cells) cDNA library. Approximately 150 genes and 60 loci are known to influence eye, skin and hair colour in mammals. Tyrosinase is a rate-limiting enzyme responsible for melanin synthesis. In addition, tyrosine-related proteins (TRPs) and their genes have been identified and cloned. Tyrosinase and TRPS (e.g., TRP-1; b-locus protein identical to HMSA-5 and TRP-2; dopachrome tautomerase) are synthesized according to underlying genetic programmes, and are up- and/or down-regulated to create various forms of abnormal melanin pigmentation. We herein propose the importance of investigating the role of non-tyrosinase related proteins such as those which we have recently identified.
Collapse
|
312
|
Hirzmann J, Luo D, Hahnen J, Hobom G. Determination of messenger RNA 5'-ends by reverse transcription of the cap structure. Nucleic Acids Res 1993; 21:3597-8. [PMID: 8346046 PMCID: PMC331478 DOI: 10.1093/nar/21.15.3597] [Citation(s) in RCA: 78] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
|
313
|
Stoll R, Luo D, Kouwenhoven B, Hobom G, Müller H. Molecular and biological characteristics of avian polyomaviruses: isolates from different species of birds indicate that avian polyomaviruses form a distinct subgenus within the polyomavirus genus. J Gen Virol 1993; 74 ( Pt 2):229-37. [PMID: 8381462 DOI: 10.1099/0022-1317-74-2-229] [Citation(s) in RCA: 58] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
The isolation and characterization of two avian polyomaviruses, from chicken (BFDV-2) and a parrot (BFDV-3), is reported. Both isolates are closely related to the non-mammalian polyomavirus budgerigar fledgling disease virus (BFDV) isolated from budgerigars (now called BFDV-1), and all three viral genomes are shown to have the same basic size of 4981 bp. A 151 bp insertion was, however, observed in the non-coding region of BFDV-2 which represented an exact duplication of the left half of the non-coding region, including the putative early promoter and amino terminus of the large T antigen. With a further 15 base pairs exchanged elsewhere throughout the three genomes, these viruses have distinct degrees of tropism for various avian species. The production of antibodies directed against a beta-galactosidase-large T antigen fusion protein of BFDV-1 is described. These antibodies detected the large T antigen, with an M(r) of approximately 80K, and the small t antigen, with an M(r) of approximately 24K, in cells infected with BFDV isolates. Whereas these antibodies bind with low affinity to the large T antigen of simian virus 40 (SV40), SV40- or mouse polyomavirus-specific antibodies will not bind to the BFDV large T antigen. Antibodies directed against BFDV structural polypeptides exhibit broad, reciprocal cross-reactivities with all three structural proteins of mammalian polyomaviruses. The significance of polyomavirus infections in various avian species is discussed. Based on unique structural and biological properties we propose that these viruses should be placed in a distinct subgenus (Avipolyomavirus) within the polyomaviruses.
Collapse
|
314
|
Chen CJ, Guo SG, Luo D, Huang YQ. Full-valve annuloplasty in treatment of primary deep venous valvular incompetence of the lower extremities. Chin Med J (Engl) 1992; 105:256-9. [PMID: 1395848] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Full-valve annuloplasty of superficial femoral venous valves was performed successfully in 139 extremities affected with primary deep venous incompetence of the lower limb. Chronic ulcerations in 43 affected extremities healed after operation. Postoperative venography showed that the recovery rate of valvular function was 97%, and no serious complication was noted. Follow-up for a mean of 3.5 years showed no varicosed vein and no recurrence of ulceration. The principles of operation, the optimum site, number and degree of annuloplasty, indications and results of the operation were discussed.
Collapse
|
315
|
Luo D. [Emery-Dreifuss muscular dystrophy--reported a family with 5 cases]. ZHONGHUA SHEN JING JING SHEN KE ZA ZHI = CHINESE JOURNAL OF NEUROLOGY AND PSYCHIATRY 1991; 24:330-1, 382. [PMID: 1800056] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Five cases of Emery-Dreifuss muscular dystrophy in four generations of a family was reported. It is a rare form X-linked recessive muscular dystrophy. The distinctive features of this disease are: Firstly, early contractures of elbows and achilles tendons and posterior cervical muscles are revealed. Secondly, muscle weakness is more proximal (scapulo-humeral) in the upper limbs and distal (anterior tibial and peroneal muscle) in the lower limbs. Thirdly, there is no calf pseudohypertrophy. Fourthly, myocardial involvement with cardiac conduction defects is frequent and important features. The CPK level is usually slightly raised. In our report, the EMG and muscle biopsies showed a mixed pattern of neurogenic and myogenic changes.
Collapse
|
316
|
Luo D, McKeown BA. Interaction of carp growth hormone-releasing factor and somatostatin on in vitro release of growth hormone in rainbow trout (Oncorhynchus mykiss). Neuroendocrinology 1991; 54:359-64. [PMID: 1684643 DOI: 10.1159/000125914] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Possible antagonism between somatostatin (SS) and carp growth hormone-releasing factor (GRF) on growth hormone (GH) secretion was examined by radioimmunoassay in a dispersed rainbow trout pituitary cell culture system. SS (3 nM) significantly antagonized carp GRF(1-29; 1 nM, 10 nM)-induced GH secretion. The slope of the dose-response curve for carp GRF(1-29) with SS was statistically different from that of carp GRF(1-29) alone (p less than 0.05) suggesting a noncompetitive antagonism of SS to carp GRF. The carp GRF(1-29) was also indicated to be a noncompetitive antagonist to SS (p = 0.056). Carp GRF(1-29; 100 nM) was unable to restore the inhibitory effect of SS on GH release after pre-exposure of SS (30 nM) to the pituitary cells. We conclude that SS antagonizes carp GRF on GH release at the pituitary level in rainbow trout and this antagonism is noncompetitive. SS has a postantagonism to carp GRF which may implicate some important physiological adaptations in teleosts.
Collapse
|
317
|
Luo D, Li Y, Deng S, Zeng X. [Prophylactic effect of refined amorphophallus konjac on MNNG-induced lung cancers in mice]. HUA XI YI KE DA XUE XUE BAO = JOURNAL OF WEST CHINA UNIVERSITY OF MEDICAL SCIENCES = HUAXI YIKE DAXUE XUEBAO 1991; 22:287-91. [PMID: 1748413] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Three hundred and seventy LACA mice of seven weeks old were used in 2 batches for studying the prophylactic effect of Konjaku powder on MNNG-induced lung cancers. These mice (within each batch) were randomly allocated to four groups, namely positive control (MNNG), refined Amorphophallus Konjac (R.A.K.), complex (MNNG + R.A.K.), and blank control (C). In MNNG group, MNNG (250 micrograms) was injected intravenously once five days for seven times in each mouse, the total dosage of MNNG was 1.75 mg. In R.A.K. group, according to w/w, 8% R.A.K. was well mixed into 92% common diet for long-term term breeding. In complex group, MNNG was given as that in MNNG group and the mice were reared as those in R.A.K. group. The mice in MNNG group and in C group were all reared by common diet. The results of experiments showed different degrees of preventive effect of R.A.K. on MNNG-induced lung cancers in LACA mice. R.A.K. not only exerted effect on the number of induced cancer, causing a drop of the cancerous rate from 79.75% to 20.00% and the mean number of cancer in each animal, but also prolonged the survival time of animals. At the same time, the constituent ratio of the kinds of tumor denoted a decrease in malignancy (adenoma with malignant change), an absence of adenocarcinoma and relative increase in benign adenoma. The results of experiments also exhibited good duplication as well as absence of adverse reactions to Konjaku powder.
Collapse
|
318
|
Li L, Luo D, Ye D. [Studies on varietal resources of Chinese medicinal plants and their preservation]. ZHONGGUO ZHONG YAO ZA ZHI = ZHONGGUO ZHONGYAO ZAZHI = CHINA JOURNAL OF CHINESE MATERIA MEDICA 1991; 16:386-8, 446. [PMID: 1910498] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
The paper reviews the status of varietal resources of Chinese medicinal plants in China. The existing problems are analysed. Characteristics of these resources are dealt with. The results have shown that the study of varietal resources of Chinese medicinal plants must be strengthened for facilitating their production. Methods of varietal preservation of these plants are also discussed.
Collapse
|
319
|
Luo D, Coen ES, Doyle S, Carpenter R. Pigmentation mutants produced by transposon mutagenesis in Antirrhinum majus. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 1991; 1:59-69. [PMID: 1668965 DOI: 10.1111/j.1365-313x.1991.00059.x] [Citation(s) in RCA: 27] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
New pigmentation mutants were generated by transposon mutagenesis in Antirrhinum majus, in three previously described loci, nivea, delila and incolorata, and two new loci, daphne and olive. The wild-type olive gene is required for the production of dark-green leaves, and the daphne gene for the synthesis of flavones. Five out of the six mutants were both germinally and somatically unstable, indicating that they resulted from transposon insertions. Molecular analysis of the mutant at nivea (niv-600) showed that it was caused by insertion of a new transposon, Tam4. The sequence of Tam4 suggests that it is unable to transpose autonomously and that it is related to Tam1 and Tam2. All three of these transposons have identical inverted repeats, produce 3 bp target duplications, leave similar excision footprints and share at one end a 600-700 bp region containing many palindromic copies of a motif sequence, possibly required in cis for transposition. The somatic excision of Tam4 in niv-600 is at a very low rate compared to germinal excision but it can be activated by crossing to lines carrying derivative alleles of a Tam1 insertion at niv. Molecular analysis of four different pigmentation mutants has shown that insertions of Tam1, Tam2, Tam3 and Tam4 have been obtained, illustrating the potential of general transposon mutagenesis for trapping and isolating new transposons as well as for tagging genes.
Collapse
|
320
|
Luo D, McKeown BA. The effect of thyroid hormone and glucocorticoids on carp growth hormone-releasing factor (GRF)-induced growth hormone (GH) release in rainbow trout (Oncorhynchus mykiss). COMPARATIVE BIOCHEMISTRY AND PHYSIOLOGY. A, COMPARATIVE PHYSIOLOGY 1991; 99:621-6. [PMID: 1679699 DOI: 10.1016/0300-9629(91)90140-8] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
1. The effect of thyroid hormone and glucocorticoids on carp growth hormone-releasing factor (GRF)-induced growth hormone (GH) secretion was studied on rainbow trout using a dispersed pituitary cell culture system. 2. A combined administration of lower doses (0.01 microM) of 3,5,3'-triiodo-L-thyronine (T3) and dexamethasone (Dex) significantly increased spontaneous as well as carp GRF-induced GH release. 3. Lower doses of Dex alone had no effect, and T3 had a marginal effect on GH release. Higher doses of either Dex or T3 potentially reduced GH release. 4. This study indicates an important role of thyroid hormone and/or glucocorticoids in the hypothalamic regulation of GH secretion in fish.
Collapse
|
321
|
Luo D. [Immunohistochemical demonstration of mycobacterial antigen]. ZHONGHUA JIE HE HE HU XI ZA ZHI = ZHONGHUA JIEHE HE HUXI ZAZHI = CHINESE JOURNAL OF TUBERCULOSIS AND RESPIRATORY DISEASES 1990; 13:360-2, 381-2. [PMID: 2128223] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
BCG antigen and M. tuberculosis antigen were demonstrated in smear of M. tuberculosis, tissue sections of experimental infected mice and tuberculous patients by immunohistochemical staining. Both acid-fast-HRP-SPA and acid-fast-IGSS double staining methods were tried successfully. Both antigens were present on acid-fast bacilli (AFB). Furthermore, BCG antigen was localized on the mycobacteria cell wall by immunoelectron-microscopic staining. Both antigens were not detected in 19 control specimens of normal tissues and the tissues infected by 8 other species bacilli or fungi except M. leprae and atypical mycobacteria (photochromogens). The rate of positive BCG antigen (69.34%, 95/137) was significantly higher than that of AFB (34.3%, 47/137), (P less than 0.01). The antigens were also found in some AFB free necrotic areas and macrophages. So, immunohistochemical detection of mycobacteria antigens is fairly specific. It is helpful in studying immunopathological changes and in the diagnosis of tuberculosis.
Collapse
|
322
|
Luo D. [Ultracytochemical observation on lysosome of hair cells in kanamycin ototoxic guinea pigs]. ZHONGHUA ER BI YAN HOU KE ZA ZHI 1990; 25:281-2, 318. [PMID: 2076337] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Using the ultracytochemical technique, we found the lysosome with high electronic density just beneath the cuticle plate in all normal hair cells; but in ototoxic group, the lysosome became multivesicular, expanded and displaced in hair cells. Occasionally the vesicles of the lysosome fused. In some of the hair cells, the cytoplasm dissolved, the membrane ruptured, the contents of the cells leaked out. In these cells the lysosome disappeared. We assume that the vesicle in the lysosome may be kanamycin and its metabolic products. The overloading and rupture of the lysosome can result in autolysis of the hair cell. This may be one of the mechanism of kanamycin ototoxicity.
Collapse
|
323
|
Chakraborty G, Yu M, Luo D, Sturman JA, Ingoglia NA. Amino acid modification of proteins in regenerating sciatic nerves of rats. J Neurosci Res 1990; 25:503-10. [PMID: 2352290 DOI: 10.1002/jnr.490250407] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Recent experiments have shown that Arg, Lys, and Leu can be incorporated posttranslationally into proteins of regenerating sciatic nerves of rats. The present experiments investigate a mixture of 15 radioactive amino acids to determine if additional amino acids can be conjugated posttranslationally to proteins of regenerating nerves. Proteins of regenerating sciatic nerves of rats were able to incorporate Arg, Lys, Leu, Pro, Val, Ala, Phe, and Ser in relatively large amounts and Asp, Glu, Thr, Gly, Ile, His, and Tyr in relatively low or undetectable amounts, in the most advanced portion of the regenerating nerves. Two-dimensional SDS PAGE showed incorporation of the amino acid mixture into distinct radioactive peaks with molecular weights in the 80-90 kD, 53-66 kD, 22-46 kD, and 17 kD ranges with isoelectric points between 5.0 and 7.9. Most of the amino acids were incorporated into proteins in all of the molecular weight ranges. But Ser was incorporated in highest amounts in the 17 kD range, and Val was most abundant in the 22-46 kD range. In some cases results indicated that single proteins were modified by several amino acids. While we do not yet know which amino acids modify specific nerve proteins or the function of the modifications in nerve regeneration, these studies demonstrate the participation of some but not all amino acids in posttranslational modification reactions and the selective modification of specific groups of nerve proteins by these amino acids.
Collapse
|
324
|
Wang X, Luo D, Wang C, Xiao B. [Observation of morphological genesis and histochemistry of pulmonary adenocarcinoma in mice]. HUA XI YI KE DA XUE XUE BAO = JOURNAL OF WEST CHINA UNIVERSITY OF MEDICAL SCIENCES = HUAXI YIKE DAXUE XUEBAO 1990; 21:54-8. [PMID: 2365343] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
In the developing process of pulmonary adenocarcinoma in mice induced by N-methyl-N'-nitro-N-nitrosoguanidine, the observations of histological pathology, ultrastructure and the changes of enzyme activity of the lesions related to pulmonary adenocarcinoma were made by light microscopy, transmission electron microscopy and enzyme histochemistry, by sacrificing animals at intervals. The results indicated that there was a series of precancerous lesions before the initiation of adenocarcinoma; that adenoma was a kind of precancerous lesion which might develop into adenocarcinoma; and that adenoma with malignant change might be a focus of early adenocarcinoma. Based on the results of histological pathology, ultrastructure and enzyme histochemistry, a process of the morphological genesis of pulmonary adenocarcinoma in mice was proposed, and the metabolic changes related to various lesions were discussed.
Collapse
|
325
|
Luo D, Pradhan AK. R-matrix calculations for electron-impact excitation of C+, N2+, and O3+ including fine structure. PHYSICAL REVIEW. A, ATOMIC, MOLECULAR, AND OPTICAL PHYSICS 1990; 41:165-173. [PMID: 9902856 DOI: 10.1103/physreva.41.165] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
|
326
|
Ingoglia N, Chakraborty G, Yu M, Luo D, Liu C. Posttranslational modification of nerve proteins by amino acids. Restor Neurol Neurosci 1990; 1:245-52. [DOI: 10.3233/rnn-1990-13411] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
|
327
|
Luo D, McKeown BA. An antioxidant dependent in vitro response of rainbow trout (Salmo gairdneri) somatotrophs to carp growth hormone-releasing factor (GRF). Horm Metab Res 1989; 21:690-2. [PMID: 2515141 DOI: 10.1055/s-2007-1009323] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
|
328
|
Luo D, McKeown BA. Immunohistochemical detection of a substance resembling growth hormone-releasing factor in the brain of the rainbow trout (Salmo gairdneri). EXPERIENTIA 1989; 45:577-80. [PMID: 2500360 DOI: 10.1007/bf01990512] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
We studied the distribution of an immunoreactive substance resembling growth hormone-releasing factor (GRF) in the hypothalamus and pituitary gland of the rainbow trout by immunofluorescence methods. The GRF-like immunoreactive perikaryon was observed in colchicine-treated fish. The majority of GRF-containing neurons were located in the nucleus lateral tuberis; others were located in the caudal part of the preoptic nucleus of the hypothalamus. The GRF-like immunoreactive neuronal processes projected into the pars distalis via the pars nervosa of the pituitary gland. The distribution of the GRF-like immunoreactive substance in the hypothalamus and pituitary gland suggests that GRF plays a physiological role in the regulation of growth hormone release from the pituitary gland of rainbow trout, as it does in mammals.
Collapse
|
329
|
Luo D, McKeown B. Immunological evidence of growth hormone-releasing factor-like substances in salmon (Oncorhynchus kisutch and O. keta). ACTA ACUST UNITED AC 1989. [DOI: 10.1016/0305-0491(89)90385-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
|
330
|
Wang YZ, Xu YZ, Luo D, Xu X. [Purification and characterization of depressor component of Agkistrodon acutus venom]. ZHONGGUO YAO LI XUE BAO = ACTA PHARMACOLOGICA SINICA 1988; 9:334-7. [PMID: 3195344] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
|
331
|
Luo D, Delos JB, Geltman S. Laser-induced collisional detachment. PHYSICAL REVIEW. A, GENERAL PHYSICS 1988; 37:2361-2364. [PMID: 9899941 DOI: 10.1103/physreva.37.2361] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
|