Biomedical subjects
Publications and source records attributed to X M Li.
Two stilbenoids, gnetupendin A and B, were isolated from the lianas of Gnetum pendulum C. Y. Cheng, together with four known compounds, resveratrol, isorhapontigenin, shegansu B and beta-daucosterol. Their structures were determined on the basis of analysis of spectral evidence, especially 2D NMR spectroscopic techniques.
The perirhinal cortex has recently been implicated in the kindling of limbic generalized seizures. The following experiments in rats tested the selectivity of the perirhinal cortex's epileptogenic properties by comparing its kindling profile with those of the adjacent insular cortex, posterior (dorsolateral) claustrum and amygdala. The first experiment examined the kindling and EEG profiles, and found that both the claustrum and insular cortex demonstrated rapid epileptogenic properties similar to the perirhinal cortex, including very rapid kindling rates and short latencies to convulsion. Furthermore, electrical stimulation of all three structures led to a two-phase progression through stage-5 seizures which had characteristics of both neocortical and amygdaloid kindling. In a second experiment rats were suspended in a harness to allow for more detailed documentation of both forelimb and hindlimb convulsions. With this procedure we were able to detect subtle yet unique differences in convulsion characteristics from each of the kindled sites and stage-5 seizure phases. Some of these convulsive parameters were correlated with changes in FosB/DeltaFosB protein and BDNF mRNA expression measured two hours after the last convulsion. Overall, it appears that the perirhinal cortex is not unique in its property of rapid epileptogenesis. Moreover, the posterior claustrum exhibited the fastest kindling and most vigorous patterns of clonus, suggesting that it may be even more intimately associated with the motor substrates responsible for limbic seizure generalization than is the perirhinal cortex.
BACKGROUND: Atopic dermatitis (AD) is an eczematous skin eruption that generally begins in early infancy and affects up to 12% of the population. The cause of this disorder is not fully understood, although it is frequently the first sign of atopic disease and is characterized by an elevated serum IgE level, eosinophilia, and histologic tissue changes characterized early by spongiosis and a CD4(+) T(H)2 cellular infiltrate. Hypersensitivity to foods has been implicated as one causative factor in up to 40% of children with moderate-to-severe AD. OBJECTIVE: The purpose of this study was to establish a murine model of food-induced AD. METHODS: Female C3H/HeJ mice were sensitized orally to cow's milk or peanut with a cholera toxin adjuvant and then subjected to low-grade allergen exposure. Histologic examination of skin lesions, allergen-specific serum Ig levels, and allergen-induced T-cell proliferation and cytokine production were examined. RESULTS: An eczematous eruption developed in approximately one third of mice after low-grade exposure to milk or peanut proteins. Peripheral blood eosinophilia and elevated serum IgE levels were noted. Histologic examination of the lesional skin revealed spongiosis and a cellular infiltrate consisting of CD4(+) lymphocytes, eosinophils, and mast cells. IL-5 and IL-13 mRNA expression was elevated only in the skin of mice with the eczematous eruption. Treatment of the eruption with topical corticosteroids led to decreased pruritus and resolution of the cutaneous eruption. CONCLUSION: This eczematous eruption resembles AD in human subjects and should provide a useful model for studying immunopathogenic mechanisms of food hypersensitivity in AD.
BACKGROUND: Allergy to peanut is a significant health problem. Interestingly, the prevalence of peanut allergy in China is much lower than that in the United States, despite a high rate of peanut consumption in China. In China, peanuts are commonly fried or boiled, whereas in the United States peanuts are typically dry roasted. OBJECTIVE: The aim of this study was to examine whether the method of preparing peanuts could be a factor in the disparity of allergy prevalence between the 2 countries. METHODS: Two varieties of peanuts grown in the United States were roasted, boiled, or fried. Proteins were analyzed by using SDS-PAGE and immunoblotting. Allergenicity was compared by using immunolabeling with sera from 8 patients with peanut allergy. RESULTS: The protein fractions of both varieties of peanuts were altered to a similar degree by frying or boiling. Compared with roasted peanuts, the relative amount of Ara h 1 was reduced in the fried and boiled preparations, resulting in a significant reduction of IgE-binding intensity. In addition, there was significantly less IgE binding to Ara h 2 and Ara h 3 in fried and boiled peanuts compared with that in roasted peanuts, even though the protein amounts were similar in all 3 preparations. CONCLUSION: The methods of frying or boiling peanuts, as practiced in China, appear to reduce the allergenicity of peanuts compared with the method of dry roasting practiced widely in the United States. Roasting uses higher temperatures that apparently increase the allergenic property of peanut proteins and may help explain the difference in prevalence of peanut allergy observed in the 2 countries.
BACKGROUND: Peanut allergy is a major cause of fatal and near-fatal anaphylactic reactions to foods. There is no curative therapy for this condition. Traditional Chinese medicines have been reported to have antiallergic properties, which might be useful for treating peanut allergy. OBJECTIVE: The purpose of this study was to investigate the effects of a Chinese herbal formula, FAHF-1, on peanut anaphylactic reactions in a mouse model of peanut allergy. METHODS: Mice were sensitized with freshly ground whole peanut in the presence of cholera toxin and boosted 1 and 3 weeks later. FAHF-1 treatment was initiated 1 week later and continued for 7 weeks. After treatment, mice were challenged with peanut, and anaphylactic symptoms, body temperatures, and plasma histamine and IgE levels were measured. T-cell proliferative responses and cytokine production were also determined. RESULTS: FAHF-1 completely blocked peanut-induced anaphylactic symptoms and markedly reduced mast cell degranulation and histamine release. Peanut-specific serum IgE levels were significantly reduced by 2 weeks of treatment at the time of challenge, and they remained lower 4 weeks after discontinuation of treatment. FAHF-1 significantly reduced peanut-induced lymphocyte proliferation as well as IL-4, IL-5, and IL-13 synthesis but not IFN-gamma synthesis. No toxic effects on liver or kidney functions were observed, nor was there any overall immune suppression. CONCLUSION: FAHF-1 protected peanut-sensitized mice from anaphylactic reactions and significantly reversed established IgE-mediated peanut allergy. This suggests that FAHF-1 might prove valuable for the treatment of peanut allergy.
A pulsatile flow in vitro model of the distal end-to-side anastomosis of an arterial bypass graft was used to examine the effects that different flow ratios between the proximal outlet segment (POS) and the distal outlet segment (DOS) have on the flow patterns and the distributions of hemodynamic factors in the anastomosis. Amberlite particles were tracked by flow visualization to determine overall flow patterns and velocity measurements were made with Laser Doppler anemometry (LDA) to obtain detailed hemodynamic factors along the artery floor and the graft hood regions. These factors included wall shear stress (WSS), spatial wall shear stress gradient (WSSG), and oscillatory index (OSI). Statistical analysis was used to compare these hemodynamic factors between cases having different POS:DOS flow ratios (Case 1-0:100, Case 2-25:75, Case 3-50:50). The results showed that changes in POS:DOS flow ratios had a great influence on the flow patterns in the anastomosis. With an increase in proximal outlet flow, the range of location of the stagnation point along the artery floor decreased, while the extent of flow separation along the graft hood increased. The statistical results showed that there were significant differences (p<0.05) for the mean WSS between cases along the graft hood, but no significant differences were detected along the artery floor. There were no significant differences for the spatial WSSG along both the artery floor and the graft hood. However, there were significant differences (p<0.05) in the mean OSI between Cases 1 and 2 and between Cases 1 and 3 both along the artery floor and along the graft hood. Comparing these mechanical factors with histological findings of intimal hyperplasia formation obtained by previous canine studies, the results of the statistical analysis suggest that regions exposed to a combination of low mean WSS and high OSI may be most prone to the formation of intimal hyperplasia.
The peroxidase isozyme and the soluble peoteins of four isonucleus-alloplasmic lines of common wheat--D2-CA8057 (fertile, BC14), CMS line msD2-CA8057(BC11), CMS line msA-CA8057(BC12), CA8057 (nucleus donor) in different developmental stages were studies by polyacrylamide gel electrophoresis (PAGE) and gradient SDS-PAGE respectively. The peroxidase isozyme of bionucleus-stage anther, milk-stage endosperm and the soluble proteins of bionucleus-stage anther, leaf (the beginning and ending overwinter), dry-seed endosperm among fertile line, msD2-CA8057 and msA-CA8057 were evidently different (but few differences between CA8057 and D2-CA8057). These differences resulted from the pecially-regulated expression of (male-sterile) cytoplasmic genes to nuclear genes and could be used to identify the four isonucleus-alloplasmic lines. These results showed that msD2-CA8057 and msA-CA8057 were two different kinds of new CMS pattern.
OBJECTIVE: To study the chemical constituents in the fruit of Lycium barbarum. METHOD: The chemical constituents were isolated by column chromatography and identified by spectral data. RESULT: The compounds obtained were identified as scopoletin(I), beta-sitosterol(II), p-coumaric acid(III), glucose(IV), daucosterol(V) and betaine(VI). CONCLUSION: Compounds III, IV and V were isolated from Lycium barbarum for the first time.
OBJECTIVE: To investigate the population constitution and geographical distribution of Plasmodium vivax in China using molecular technique. METHODS: Blood-spot filter paper samples with related epidemiological data were collected from vivax malaria patients living in malarious area of 10 provinces (autonomous region) in China. Semi-nested- or nested-allelic-specific PCR genotyping method was used to identify CSP genotypes, families and types of Plasmodium vivax of each isolate from these patients. RESULTS: Of 384 field isolates of Plasmodium vivax, 258 temperate zone family strains were identified, including 14 allelic variant genotypes spreading among 10 sampling provinces; allelic variants sized less than 731 bp were only seen in 5 provinces in southern China; 79 tropical zone family strains including 5 genotypes were also distributed in 5 provinces of southern China south to 25 degrees N. lat; and 14 PV Type-2 strains including 2 genotypes were found in some areas of Hainan and Yunnan Provinces. In addition, 33 isolates from genotype-mixed infections were revealed. CONCLUSION: At present, area north to 25 degrees N. lat. of the country is the sole area prevalent for Plasmodium vivax family strains of temperate zone; there is overlapping distribution of P. v. of temperate zone family and tropical zone family of this parasite in the southern China south to 25 degrees N. lat; where the most complex isolate constitution is in Yunnan and Hainan Provinces, and PV Type-2 strains have been found in some areas of the two provinces. Besides, there were 2 groups of genotype with distinct geographic distribution feature within the temperate zone family.
OBJECTIVE: To explore the effect of Nephropathy mixture on genetic expression of liver albunin in rats with adriamycin-induced nephrotic syndrome. METHODS: The rat model of adriamycin-induced nephrotic syndrome was established and the liver albumin mRNA expression level was observed with Northern hybridization and Dot-blot quantitative analysis. RESULTS: The liver albumin mRNA expression level in the Nephropathy Mixture treated group was significantly higher than that in the model group and the normal control group (P < 0.05). CONCLUSION: Nephropathy Mixture could up-regulate the liver albumin mRNA expression level and promote the synthesis of albumin in rats with adriamycin-induced nephrotic syndrome.
OBJECTIVE: In order to explore the therapeutic mechanism of Langchuangding (LCD) in treating systemic lupus erythematosus (SLE) by observation of its effect on serum soluble interleukin-2 receptor (sIL-2R) and neopterin level in SLE patients. METHODS: Forty-five patients of SLE were randomly divided into two groups, the 25 cases in the treated group were treated with LCD plus glucocorticoid (GCC) and the 20 cases in the control group were treated with GCC alone. The levels of sIL-2R and neopterin were observed before and after treatment by double antibody sandwich ELISA. RESULTS: SLE patient showed higher levels of sIL-2R and neopterin than normal, and being higher in active stage than in remission stage. The level of neopterin was positively correlated with erythrocyte sedimentation rate (ESR) (r = 0.86, P < 0.01). After treatment, the levels of sIL-2R and neopterin were lowered significantly in the treated group than those in the control group (P < 0.05). CONCLUSION: LCD could effectively reduce the serum levels of sIL-2R and neopterin in SLE patients, which would be beneficial to cellular immune functional regulation and induce the disturbed internal environment of immunity to homeostasis.
OBJECTIVE: To isolate a kind of endophytic fungus which can produce taxol compounds from the bark of Taxus Cuspidata Sieb et Zucc. METHODS: Endophytic fungus was isolated from the bark of Taxus Cuspidata Sieb et Zucc by aseptic techniques and the analysis of the culture fluid from the fermentation of fungus was carried out by high performance liquid chromatography (HPLC). RESULTS: Endophytic fungus was obtained from the bark of Taxus Cuspidata Sieb et Zucc and the chemical analysis showed that the culture of fungus contain taxol compounds. CONCLUSION: Endophytic fungus which can produce taxol compounds exists in the bark of Taxus Cuspidata Sieb et Zucc.
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CpG oligodeoxynucleotides (CpG-ODN) administered during Ag sensitization or before Ag challenge can inhibit allergic pulmonary inflammation and airway hyperreactivity in murine models of asthma. In this study, we investigated whether CpG-ODN can reverse an ongoing allergic pulmonary reaction in a mouse model of asthma. AKR mice were sensitized with conalbumin followed by two intratracheal challenges at weekly intervals. CpG-ODN was administered 24 h after the first Ag challenge. CpG-ODN administration reduced Ag-specific IgE levels, bronchoalveolar lavage fluid eosinophils, mucus production, and airway hyperreactivity. We found that postchallenge CpG-ODN treatment significantly increased IFN-gamma concentrations and decreased IL-13, IL-4, and IL-5 concentrations in bronchoalveolar lavage fluids and spleen cell culture supernatants. Postchallenge CpG-ODN treatment also increased B7.1 mRNA expression and decreased B7.2 mRNA expression in lung tissues. These results suggest that CpG-ODN may have potential for treatment of allergic asthma by suppressing Th2 responses during IgE-dependent allergic airway reactions. The down-regulation of Th2 responses by CPG-ODN may be associated with regulation of the costimulatory factors B7.1 and B7.2.
Phosphoinositide 3 kinase/Akt pathway plays an essential role in neuronal survival. However, the cellular mechanisms by which Akt suppresses cell death and protects neurons from apoptosis remain unclear. We previously showed that transient expression of constitutively active Akt inhibits ceramide-induced death of hybrid motor neuron 1 cells. Here we show that stable expression of either constitutively active Akt or Bcl-2 inhibits apoptosis, but only Bcl-2 prevents the release of cytochrome c from mitochondria, suggesting that Akt regulates apoptosis at a postmitochondrial level. Consistent with this, overexpressing active Akt rescues cells from apoptosis without altering expression levels of endogenous Bcl-2, Bcl-x, or Bax. Akt inhibits apoptosis induced by microinjection of cytochrome c and lysates from cells expressing active Akt inhibit cytochrome c induced caspase activation in a cell-free assay while lysates from Bcl-2-expressing cells have no effect. Addition of cytochrome c and dATP to lysates from cells expressing active Akt do not activate caspase-9 or -3 and immunoprecipitated Akt added to control lysates blocks cytochrome c-induced activation of the caspase cascade. Taken together, these data suggest that Akt inhibits activation of caspase-9 and -3 by posttranslational modification of a cytosolic factor downstream of cytochrome c and before activation of caspase-9.
The administration of subconvulsive doses of kainic acid (5 mg/kg, intraperitoneally) to rats, with lesion of the substantia nigra pars reticulata (1 week), produced high frequency wet dog shakes and severe convulsive behavior (observed in 60% of the rats). The behavior was not observed in rats treated with kainic acid but without reticulata lesion. The results show that rats with unilateral lesion of the substantia nigra pars reticulata are more vulnerable to seizure stimuli.
A high-performance liquid chromatographic-mass spectrometric (HPLC-MS) method has been developed for determination of clopidol residues in chicken tissues. Samples are extracted with acetonitrile. The extracts are cleaned up on an alumina column followed by an anion-exchange column. The clopidol is separated on a column (150 cmx4.6 mm) of Intertsil by using acetonitrile-water (20:80) as mobile phase. The clopidol was qualitatively identified by molecule mass and determined quantitatively by selected ion monitoring mode at 190 m/z. The recoveries with RSDs ranged from 91.6+/-10.1 to 97.3+/-5.7 at 0.010 to 10.0 mg/kg by spiking three matrices (chicken muscle, liver, and kidney). The limit of detection was 0.005 mg/kg, and the limit of quantification was 0.010 mg/kg.
This paper deals with the different GC-MS analytical conditions adopted by four laboratories in an attempt to confirm the accuracy of the GC-electron-capture detection (ECD) analytical results during the international collaborative study for the establishment of the AOAC Official Method 998. 01. What is especially noted is that two laboratories have conducted comparative analysis of the respective 12 blind samples with both methods of GC-ECD and GC-MS, and the analytical results of the two methods turn out to be basically identical. This fully demonstrates that GC-MS is not only an effective confirmation tool in the analysis of the pyrethroid residues but also of sufficient sensitivity regarding the maximum residue limit of determination prescribed by FAO/WHO. Moreover, its selectivity is better than GC-ECD.