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Biomedical subjects

G Lu

Publications and source records attributed to G Lu.

At least 181 records · Page 10Linked to original sources
PubMed1994

Characteristics of acupuncture meridians and acupoints in animals.

In recent years, an increasing number of studies has been conducted on the biophysical characteristics of the meridians and acupoints in humans and animals. The authors aim to further illustrate the objective existence and superficial locations of the meridians in various species of animals. Twelve sheep, ten goats, thirteen pigs, eleven cats, eight rabbits and seven donkeys were used to measure low impedance lines (LILs) and high percussion sound lines (HPSLs) on the skin surface of the animals, along the vertical planes of the dorsal line, using electrical impulses and high percussion sound. The results of these studies are given.

Acupuncture Points↗
PubMed1994

The autocrine regulatory effect of vasoactive intestinal peptide on the growth of human pancreatic carcinoma cells.

In the present study, the effects of VIP on the growth of two human pancreatic carcinoma cell lines PU-PAN-1 and PANC-1 were determined using tritiated thymidine incorporation. VIP receptors, intracellular cAMP and polyamines were investigated. The results indicated that VIP at a concentration of 10(-8) mol/L to 10(-7) mol/L can significantly stimulate the growth of PU-PAN-1 cells but not PANC-1 cells. This effect is dose-dependent and abolished by VIP receptor antagonist, [4-C1-Phe6, Leu17] VIP, suggesting VIP receptors in PU-PAN-1 cells may mediate this effect. VIP can markedly elevate the levels of intracellular cAMP and polyamines in PU-PAN-1 cells, indicating that the growth-promoting effect stimulated by VIP may be via a rapid increase in the biosyntheses of cAMP and polyamines. In addition, the VIP-antibody inhibited the growth of PU-PAN-1 cells in serum-free culture medium. The results above suggested that VIP has an autocrine regulatory effect on this pancreatic carcinoma cell line (PU-PAN-1).

Biogenic Polyamines↗
PubMed1994

Study on the mechanism and effects of Gly-Tyr-NH2 and Gly-Tyr-Lys on rat luteal cells in vitro.

The action of Gly-Tyr-NH2, (GY-NH2) and Gly-Tyr-LYS(GYK) on 125I-LH binding, cAMP accumulation and progesterone production was investigated. Incubation of rat luteal cells for 2.5 h with GY-NH2 and GYK at dosage of 0.2 mmol/L caused a significant inhibition of basal and gonadotropin-stimulated steroidogenesis. GY-NH2 and GYK were also found to reduce cAMP formation in response to hCG. The activity of adenylate cyclase of luteal cells was inhibited by 0.2 mmol/LGY-NH2 and GYK. GY-NH2 and GYK at a concentration of 0.2 mmol/L were not found to have an inhibitory effect on 8Br-cAMP-stimulated progesterone production. GY-NH2 and GYK did not affect 125I-LH binding to LH receptors on the luteal cell surface. These results suggest that GY-NH2 and GYK inhibit steroidogenesis at the step of gonadotropin-stimulated cAMP formation in luteal cells. Adenylate cyclase in luteal cells was also inhibited.

Adenylyl Cyclases↗
PubMed1994

Effects of beta-endorphin on phytohemagglutinin-induced lymphocyte proliferation and mouse plaque-forming cell response via an opioid receptor mechanism.

The effects of opioid peptides on immune responses were investigated. It was found that beta-endorphin (beta-END) can depress proliferative responses to PHA in rat splenocytes but enhance those in mice, and it could also inhibit the plaque-forming cell (PFC) response to sheep red blood cells when mouse splenocytes immunized in vivo were cultured in vitro with the peptide. The peptide antagonist naloxone was able to reverse beta-END suppression of the PFC response. The data indicate that beta-END suppresses antibody production or secretion via a specific opioid-receptor-mediated mechanism.

Animals↗
PubMed1994

[The adherence reaction between Candida and cultured cell in vitro].

The adherence reaction between Candida and cultured cells in vitro was studied. After the comparison between two fungal phases, two different ratios of cells to fungi and two different incubation temperature, we found that the better adhesion condition is at 37 degrees C, with a concentration of cell to fungi of 1:200 and with the Candida albicans in the germ tube phase. We also found 4 different materials that could inhibit C. albicans adherence.

Animals↗
PubMed1994

Comparative observations on the types of atrophic gastritis and biopsy pathology of gastric mucosa.

300 cases of chronic atrophic gastritis were classified into 3 types of qi-deficiency of spleen and stomach, yang-deficiency of spleen and stomach, and yin-deficiency of spleen and stomach according to syndrome differentiation of traditional Chinese medicine. The biopsy specimens of gastric mucosa were examined histopathologically and for the presence of pyloric spirobacteria. The results showed that the type of yin-deficiency was the most serious in the degree of pathologic changes, or the glandular atrophy and the interstitial inflammatory cellular infiltration, while the rate of pyloric spirobacteria presence was comparable in all types.

Biopsy↗
PubMed1994

[Observation on the action of extractum semen Persicae on anti-fibrosis of liver].

It was observed that Extractum Semen Persicae acted obviously on hepatic fibrosis induced by CCl4. Through promoting the degradation of collagens type I, II, IV, VI and fibronectin, ESP has proved helpful in markedly reducing the fibrous septa composed of both collagenous and reticular fibers as well as in repairing the structure of hepatic tissues.

Amygdalin↗
PubMed1994

[Studies on deoxynivalenol contamination in grain and its products in Anhui Province].

Contamination of deoxynivalenol (DON) in wheat, corn, barley, and wheat flour produced in Anhui Province were examined with thin-layer chromatography in 1983-1991. In total, 672 specimens were determined, and 63.2% of them were contaminated by DON, with an average contents of 908.7 micrograms/kg (a range of 0-13330 micrograms/kg). The contamination of DON in wheat and wheat flour was more severe than that in corn (P < 0.01). There was highly significant difference in the contamination of DON in wheat produced in different areas and years, with a P-value less than 0.01 by ANOVA, but no significant difference in corn (P > 0.1). It suggested the contamination of DON correlated with the incidence of scabby wheat in that area during these years.

Food Contamination↗
PubMed1993

Morphological differentiation of neuropeptide Y neurons in aggregate cultures of dissociated fetal cortical cells: a model system for glia-neuron paracrine interactions.

The temporal changes in the morphological profiles of neuropeptide Y (NPY) neurons and their topographical relationship with glial cells (astrocytes) were characterized in aggregate cultures derived from fetal cortical tissue using immunocytochemical procedures. On day 6 of culture, structures labelled with NPY antibodies were small and uneven in size but many resembled neuronal cell bodies. On day 14, neuronal perikarya were well defined and several morphological types of NPY neurons could be distinguished most of which gave rise to beaded processes: unipolar or multipolar bitufted neurons whose processes branch in close proximity to the cell body; bipolar neurons; and multipolar neurons. On day 23, heavily punctate and asymmetrically labelled cell bodies were dispersed throughout the aggregate; neuronal processes were less conspicuous. At 14 and 23 days, cells expressing glial fibrillary acidic protein (GFAP) and neuronal specific enolase (NSE) were abundantly distributed throughout the aggregate. Using a double immunoreaction on 14-day-old aggregates revealed that GFAP+ cells and their processes were in close apposition to and engulfing the NPY neurons. Thus, dissociated fetal NPY neurons undergo morphological differentiation in culture along with astrocytes (GFAP+) and other neuronal cell types (NSE+). Based on the topographical association of astrocytes and neurons, particularly NPY neurons, we propose that the aggregate culture system can serve as a model to study the role of paracrine interactions in the regulation of the expression of NPY.

Animals↗
PubMed1993

Altered epidermal growth factor signal transduction in activated Ha-ras-transformed human keratinocytes.

Epidermal growth factor (EGF) can stimulate proliferation and 92 kDa gelatinase/matrix metalloproteinase (MMP-9) expression. The induction of MMP-9 is not only pathologically significant for invasion and metastasis, but also serves as a semiquantitative measure of EGF signal transduction. In order to examine the role of mutated ras p21 in EGF signal transduction, an activated Ha-ras-transformed human keratinocyte cell line was developed and characterized. Overexpression of the mutated Ha-ras p21 in these cells was demonstrated. Our results showed that EGF induced 92 kDa MMP-9 secretion was doubled in the ras-transformed keratinocytes in comparison to the parent cells. The karyotype, the expression of EGF receptor (EGFR) and transforming growth factor (TGF) alpha at the mRNA level remained unchanged. These results suggest that the presence of high levels of mutated ras p21 may be responsible for the aberrant EGF signal transduction and contributes to transformation. In addition, a reduction of TGF beta expression at mRNA level by 70% was found in the activated Ha-ras-transformed keratinocytes when compared to the parent cells.

Cell Line, Transformed↗
PubMed1993

Sequence analysis and antigenic cross-reactivity of a venom allergen, antigen 5, from hornets, wasps, and yellow jackets.

Ag 5 is a major allergen of vespid venom. The complete amino acid sequences of Ag 5 from two species each of hornets (Dolichovespula arenaria and maculata), wasps (Polistes annularis and exclamans), and yellow jackets (Vespula maculifrons and vulgaris) have been determined by amino acid sequencing and/or cDNA cloning. The sequence data reveal several conserved and variable regions for vespid Ag 5. The conserved regions show greater sequence similarity than do the less conserved regions to a family of proteins from human, mouse, and rat testis and to a class of pathogenesis-related proteins from tobacco and tomato leaves. Tests in the murine system for both T and B cell responses demonstrate a high degree of cross-reactivity of hornet Ag 5 with wasp or yellow jacket Ag 5 and a low degree of cross-reactivity of yellow jacket Ag 5 with wasp Ag 5. This pattern of cross-reactivity is in the same order as their sequence similarity.

Allergens↗
PubMed1993

Homopurine/homopyrimidine sequences as potential regulatory elements in eukaryotic cells.

1. Homopurine/homopyrimidine (PuPy) repetitive duplex sequences can form intramolecular triplexes (H-DNA) or intermolecular triplexes with a third strand in a sequence-specific manner. 2. Such sequences are present in natural genomes within 5'- and 3'-flanking sequences and coding regions of genes. Triplex DNA structures have been detected in vitro and in vivo and have been immunolocalized to chromosomes by triplex-specific monoclonal antibody approaches. 3. Intermolecular triplex formation represses gene expression at the transcriptional level and is also useful in genomic mapping, gene cloning, sequence-specific drug delivery, and selective modulation of gene expression.

Animals↗
PubMed1993

Review of the cytogenetic changes in acute megakaryoblastic leukemia: one disease or several?

The karyotypes of 116 cases of acute megakaryoblastic leukemia (AMKL) were reviewed, including 43 pediatric patients with Down syndrome (DS) and 73 non-DS patients. DS patients with AMKL often had a history of transient leukemia or myelodysplasia with an early age of onset of AMKL (median 23 months). In these patients, the frequency of additional cytogenetic change (numerical or structural) was low, with 10 of the 43 DS patients showing no additional cytogenetic change. A second group of patients had t(1;22)(p13;q13) or other cytogenetic abnormality involving 22q13. These patients had no history of transient leukemia but showed very early onset of AMKL. In this group of patients, marked organomegaly was noted; these patients also showed few specific additional cytogenetic changes. The remaining AMKL patients had a median age of 30 years with much more frequent cytogenetic changes, including rearrangement of 3q21 and 3q26-27, trisomy 21, and other specific changes. Based on the karyotype and clinical data, we hypothesize that AMKL may represent at least three separate disease entities with different genetic alterations giving rise to similar, but not identical, disorders. Subclassification of AMKL on the basis of the cytogenetic changes in the leukemic cells appears to be justified.

Adolescent↗
PubMed1993

Dietary arachidonate enhances tissue arachidonate levels and eicosanoid production in Syrian hamsters.

Eicosanoids are oxidative derivatives of arachidonic acid. When produced in excess many of them are proinflammatory agents. This study investigates whether dietary arachidonic acid enhances arachidonic acid phospholipid content of various tissues and whether this enrichment increases eicosanoid production. Male Syrian hamsters were divided into four groups and fed diets supplemented with ethyl esters of oleic acid, linoleic acid, arachidonic acid or eicosapentaenoic acid. Differences in the composition of the phospholipid fatty acids were monitored in liver, lung, heart, spleen, kidney, testes, macrophages and platelets. In all tissues analyzed, the phospholipid content of arachidonic acid was significantly higher in the arachidonic dietary group compared with all other dietary groups (average > 50% higher). In contrast, increasing dietary linoleic acid by 50% had little effect on altering tissue arachidonic acid levels. Following in vitro stimulation, macrophages and platelets from animals maintained on arachidonic acid produced, in general, the highest levels of eicosanoids compared with cells from animals fed the other diets. Significant differences were observed in prostaglandin E2 (macrophages) and thromboxane B2 (platelets) formation when compared with the oleic acid and eicosapentaenoic acid dietary groups. The data demonstrate that including low to moderate levels of arachidonic acid in the diet increases macrophage and platelet arachidonic acid levels and may augment eicosanoid production.

Analysis of Variance↗
PubMed1993

Arrhythmogenic doses of epinephrine are similar during desflurane or isoflurane anesthesia in humans.

BACKGROUND: Inhaled anesthetics can alter the arrhythmogenicity of exogenously administered epinephrine. Although swine anesthetized with desflurane or isoflurane do not differ in their arrhythmic response to exogenous epinephrine, the relative effect of epinephrine in the presence of these anesthetics in humans is untested. METHODS: The authors compared the arrhythmogenicity of submucosally administered epinephrine in 36 ASA physical status 1 and 2 patients undergoing transsphenoidal resection of pituitary tumors who were randomly assigned to receive 1.0-1.3 MAC desflurane or isoflurane anesthesia. A surgeon, blinded to the administered anesthetic and the concentration of epinephrine, injected 1:50,000, 1:75,000, or 1:100,000 (20, 13.3, or 10 micrograms/ml) epinephrine in saline of volumes sufficient for surgical need. The authors defined a positive response as three or more premature ventricular contractions (PVCs) in the 5 min after starting the injection. RESULTS: No patient given either anesthetic developed any PVCs with epinephrine doses less than 7.0 micrograms/kg. Greater doses of epinephrine (7.0-13.0 micrograms/kg) produced positive responses at equal frequencies in the two anesthetic groups. CONCLUSIONS: The authors concluded that isoflurane and desflurane do not differ in their sensitization of human myocardium to the arrhythmogenic effects of exogenously administered epinephrine.

Adolescent↗
PubMed1993

[Pulmonary embolism: an analysis of 25 patients].

We reported 25 cases of patients with pulmonary embolism (PE) definitely diagnosed in our hospital from 1983 to 1990. Twenty-one cases of them were found in the last 5 years. This indicated that the discovery rate had increased obviously. Five of these patients were confirmed by autopsy, the other twenty cases were diagnosed by clinical manifestations combined with perfusion-inspiration lung scans and chest roentgenogram. Due to the prompt diagnosis and the appropriate use of anticoagulants, 72% of the patients survived after treatment. We suggest that all the patients with suspected PE should take perfusion-inspiration lung scans, because this is a noninvasive and reliable method. Digital subtraction angiography is necessary for some patients. Routine chest radiography, arterial blood gas analysis, intrapulmonary shunt test, deep venography or nuclide scan of lower extremities are also useful methods for the diagnosis of PE.

Angiography, Digital Subtraction↗
PubMed1993

Histopathological study of congenitally diabetic yellow KK mouse lens.

Lenses of Yellow KK mice with marked obesity and diabetic symptoms were examined by light and electron microscopy. At 2 months of age, the entire lens appeared normal. At 4 months, however, epithelial cells sometimes had become necrotic and showed intranuclear inclusions. At 6 months, the anterior cortical fibers were swollen. At 8 months, the number of intranuclear inclusions of the epithelial cells had increased, and the posterior cortex contained densely stained cells among the fibers, with swollen cytoplasm. At 10 months, these cells had become atrophic. At 12 months, the lens cells in the posterior sutural area showed marked swelling, and the suture was almost separated. This animal model showed a slow progressive cataract in the superficial cortical zone which is similar to the diabetic cataract in human eyes.

Animals↗