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Biomedical subjects

Q Yang

Publications and source records attributed to Q Yang.

At least 469 records · Page 26Linked to original sources
PubMed1993

Changes of T cell subsets in peripheral blood of patients with Schistosomiasis japonica and their relation to interleukin-1.

T cell subsets in peripheral blood were phenotyped in 56 patients with different stages of Schistosomiasis japonica, including 17 with acute, 14 with chronic and 25 with advanced infection. The activity of interleukin-1 (IL-1) produced by peripheral blood mononuclear cells (PBMC) induced by lipopolysaccharide (LPS) in vitro was simultaneously detected in these three groups of patients. It was found that the percentages of CD3+ (total T cell), CD4+ (helper/inducer T cell) and CD8+ (suppressor/cytotoxic T cell) T cell and the level of IL-1 were significantly increased in the group of acute Schistosomiasis japonica. In the groups of chronic and advanced Schistosomiasis japonica, the proportion of CD3+ T cell, the ratio of CD3+/CD4+ and the level of IL-1 were remarkably reduced, and the percentage of CD8+ T cell was increased. The rate of CD4+ T cell was obviously decreased in cases patients with advanced Schistosomiasis japonica. The percentage of CD4+ T cell was positively correlated to the level of IL-1 in the three groups of patients. These results indicate that T cell subsets and IL-1 may play an important role in the immunoregulation of Schistosomiasis japonica.

Adolescent↗
PubMed1993

Vitamin E requirement of rats fed on a diet containing grains from the endemic region of Keshan disease.

Keshan disease (KD) is an endemic cardiomyopathy occurring in China. Combined selenium and vitamin E (VE) deficiency might be involved in the development of KD. It was shown in this paper that addition of 20 and 100 mg/kg DL-alpha-tocopherol tended to decrease malondialdehyde (MDA) content of myocardium in the rats receiving the low selenium (0.013 ppm) grains from the endemic region of KD, but not to a statistically significant extent. And addition of 200 mg/kg DL-alpha-tocopherol significantly decreased the myocardial MDA content, which suggested that VE requirement of the rats receiving KD endemic grains was 200 mg/kg DL-alpha-tocopherol. However, the MDA content in the myocardium of rats receiving KD grains added with 100 mg/kg DL-alpha-tocopherol was significantly decreased when selenium (0.1 ppm) was supplemented, which suggested that VE requirement of these rats was decreased to 100 mg/kg DL-alpha-tocopherol in the presence of selenium. The ability of VE in counteracting free radicals in myocardium of rats appeared greater than that of selenium.

Animals↗
PubMed1993

[Screening for risk factors in agricultural schools of 5 Austrian federal counties ].

While screening activities have already been performed in a wide range in adults in Austria, extensive investigations in children and juveniles have so far only been done in a very limited number. In 1094 out of 1732 juveniles attending agricultural schools all lipid parameters were fully documented and thus could be evaluated. On an average, the total cholesterol (169 mg/dl) was too high; the worst findings for lipid parameters cholesterol, HDL-cholesterol, triglycerides, apolipoprotein-A1 were found in pupils of Burgenland. The cholesterol/HDL-cholesterol ratio in Burgenland was significantly (p < 0.01) higher than in Lower Austria. Female participants had a higher total cholesterol, HDL-cholesterol, and apolipoprotein-A1, but lower triglycerides and also lower blood pressure. Juveniles with a positive family history showed lower total cholesterol, but higher triglycerides as well as HDL-cholesterol. In heavy smokers, but also in occasional smokers, a lower total cholesterol, but decreased HDL-cholesterol and apolipoprotein-A1 and increased triglycerides were found. These findings underline the high prevalence of hypercholesterolemia in juveniles justifying screening activities and possibly therapeutic intervention at this young age.

Adolescent↗
PubMed1992

Effect of irradiation on the prostaglandin system of human hypernephroma cells.

Specific PGE1-, PGE2-, PGI2-binding sites and the eicosanoid production were investigated in cultured human hypernephroma cells. Low numbers of PGE1-, PGE2- as well as PGI2-high-affinity binding sites and high levels of PG-production were found as compared to normal kidney. Treatment with acetylsalicyclic acid (ASA) significantly (p less than 0.01) increased PGE1-, PGE2- and PGI2-binding sites and inhibited PG-formation. Following irradiation, PG-receptors and eicosanoid generation were significantly (p less than 0.01) diminished, however, were insignificantly lowered in the ASA-treated group. These findings suggest that ASA may modify the radioresponse of cultured hypernephroma cells by preventing the decrease of PG-receptors induced by irradiation.

Aged↗
PubMed1992

Histamine immunohistochemistry: a new and highly sensitive method for studying cutaneous mast cells.

Mast cells have characteristic granulae containing various glucoseaminoglycans, proteases and amines (predominantly histamine). The conventional histological methods for studying mast cells are based upon acidic ortho- and metachromatic routine stains of the glucoseaminoglycans. However, the success of these procedures is dependent upon both the fixatives and the tissues used. In this study, we wanted to find out whether an immunohistochemical procedure could overcome some of these difficulties. Normal human skin was fixed in five different types of fixative and processed for indirect immunofluorescence, using an antiserum to histamine. Only one, 4% carbodiimide in 0.1 M phosphate buffer (pH 7.4), resulted in immunostaining. The quality of the staining was good, with a high signal-to-noise ratio, and was located on the mast cells. The method made it possible to visualize small structures such as a single secreted granula, the thin cytoplasmatic extension of some cells, and a previously undescribed dendritic morphology of some of the mast cells. We therefore recommend this procedure for cellular studies of mast cells when accuracy is needed.

Adult↗
PubMed1992

Tissue-restricted accumulation of a ribosomal protein mRNA is not coordinated with rRNA transcription and precedes growth of the sea urchin pluteus larva.

We have identified an mRNA that encodes a protein, SpS24, of the small ribosomal subunit in the sea urchin, Strongylocentrotus purpuratus. RNA blot and in situ hybridization analyses show that the SpS24 gene is active during early oogenesis, downregulated in the mature egg and during cleavage, and reactivated in the early blastula. The mRNA then increases in abundance at least 100-fold. Later in development, expression of SpS24 mRNA becomes restricted primarily to cells in the oral ectoderm and endoderm of the pluteus larva, and the message is undetectable in aboral ectoderm cells and most mesenchyme cells. To determine whether transcription of the ribosomal RNA genes occurs at a higher rate in oral ectoderm and endoderm tissues, a probe for the transcribed spacer was used in RNase protection and in situ hybridization assays. High concentrations of rRNA-processing intermediates were observed in unfertilized eggs and shown to reside primarily, if not exclusively, in the cytoplasm. The spatial and temporal distributions of these sequences strongly suggest that they are associated with heavy bodies. New embryonic rRNA transcripts are first detectable at the very early blastula stage. In later embryos, the content of this transcribed spacer sequence is similar in all but a few cells, which implies that they synthesize rRNA at a similar low rate. Comparison of available estimates of rRNA transcription rate with the potential rate of SpS24 protein synthesis, calculated from SpS24 mRNA prevalence, shows that oral ectoderm and endoderm cells have the capacity to synthesize 15- to 30-fold more SpS24 protein than is required to keep pace with rRNA synthesis in these cells. Because the sea urchin embryo develops from an egg to a pluteus larva in the absence of growth, this stockpiling of SpS24 mRNA anticipates rather than accompanies the onset of growth, which does not begin until after feeding. Upregulation of this gene is therefore part of the developmental program, rather than a physiological response to nutrient availability.

Amino Acid Sequence↗
PubMed1992

Mutational analysis of the adeno-associated virus rep gene.

The replication (rep) gene of the human parvovirus adeno-associated virus (AAV) is a pleiotropic effector of numerous viral functions and experts profound effects on cellular transformation. Of the four Rep proteins, the primarily nuclear Rep78 and Rep68 direct AAV DNA replication, trans activation of the capsid (cap) gene promoter, and inhibition of cellular proliferation mediated by various oncogenes. In an initial attempt to define functional domains in Rep78, we have constructed a comprehensive set of XhoI linker insertion and deletion mutations in the rep gene. Each of the mutant genes has been expressed in cell culture and assayed for the following functions: (i) nuclear localization, (ii) AAV DNA replication, (iii) trans activation of the AAV capsid gene transcription promoter, and (iv) suppression of cellular transformation mediated by the adenovirus E1a and an activated ras oncogene pair. Modest disruptions in the normal conformation of Rep78 inactivated its AAV DNA replication function and trans activation of the cap gene promoter. Linker insertion mutations in the amino-terminal one-third of the protein inactivated Rep78's ability to suppress oncogene-mediated cellular transformation. The transformation suppression domains are not limited to the amino-terminal regions, however, since deletions throughout the protein altered its suppression capabilities. A putative nuclear localization signal that is essential for each of the above functions was found in the Rep proteins. These results provide a preliminary screening of the functional domains in the AAV Rep proteins and pave the way for more subtle mutational analysis.

3T3 Cells↗
PubMed1992

Binding of 111In-labeled HDL to platelets from normolipemic volunteers and patients with heterozygous familial hypercholesterolemia.

High density lipoproteins (HDLs; d = 1.063 - 1.21 g/ml) were isolated by ultracentrifugation and radiolabeled with 111In. The in vitro binding onto platelets from healthy volunteers (n = 15) and patients (n = 36) with heterozygous familial hypercholesterolemia (FH) was investigated. Binding was saturable and indicated high-affinity binding sites, which bound 1,882 +/- 361 ng protein of 111In-HDL/10(9) platelets (dissociation constant [Kd] = 7 +/- 3 micrograms protein/ml) in healthy volunteers and significantly (p less than 0.01) lower amounts in the FH patients (1,012 +/- 439 ng protein of 111In-HDL/10(9) platelets [Kd = 12 +/- 4 micrograms protein/ml]; p less than 0.01). The capacity to displace one half of the bound ligand (IC50) amounted to 14 +/- 3 micrograms protein/ml in healthy volunteers and 22 +/- 9 micrograms protein/ml in FH patients (p less than 0.001). Treatment with lipid-lowering drugs (gemfibrozil, alone or in combination with cholestyramine) in 10 patients resulted in an increased HDL binding capacity: before treatment, 1,280 +/- 883; after 2 months of treatment, 2,052 +/- 873 (p less than 0.05); and after 6 months of treatment, 2,127 +/- 812 ng protein/10(9) platelets (p less than 0.01). There was a significant (p less than 0.001) correlation between 111In-HDL binding data and plasmatic lipid and lipoprotein values. Furthermore, those FH patients with the additional risk factors of smoking (p less than 0.05) and hypertension (p less than 0.01) showed significantly lower 111In-HDL binding onto platelets. The findings indicate specific 111In-HDL binding sites for human platelets, which may be decreased in patients with heterozygous FH. Upregulation of HDL binding sites during lipid-lowering medication therapy supports the hypothesis that high-affinity HDL binding is involved in hyperlipemic disorders and is possibly related to the reactivity of platelets.

Adult↗
PubMed1992

Cloning and partial sequencing of the porcine growth hormone (pGH) gene from pituitary gland.

High molecular weight DNA was isolated from porcine pituitary gland, and a genomic library was constructed using lambda EMBL3 as cloning vector. Five positive clones were identified by in-situ hybridization with the full-length pGH cDNA as the probe. Dot-blot hybridization, restriction analysis, and Southern hybridization showed that one of the positive clones contained the entire pGH gene. A subclone that contained the upstream sequence from the SmaI site of pGH gene was identified, and part of it was sequenced. We also compared the sequence of our pGH gene with the corresponding sequence of the published pGH gene.

Amino Acid Sequence↗
PubMed1992

[The endocrine abnormalities of depressive patients].

In the present study, the levels of the baseline cortisol, thyrotropin (TSH), triiodothyronine (T3), thyroxine (T4) and growth hormone (GH) were determined in 64 depressive patients, 17 patients with other depressive disorders and 19 normal controls. Meanwhile, dexamethasone suppression test (DST) and insulin tolerance test (ITT) were conducted. The baseline cortisol level at 23:00 in the depressive group (8.12 +/- 5.55 micrograms/dl) was significantly higher than that in the normal control group (4.80 +/- 2.10 micrograms/dl), and DST nonsuppression ratio in the depressive group (14.5%) was significantly higher than those in the other two groups (0%). There were not significantly differences in the levels of the baseline TSH, T3 and T4 between the three groups. There were not significantly differences in the baseline GH level between the three groups, but GH level in the depressive group at 90 min. after infusing insulin was significantly lower than that in the normal control group. The results showed the HPA axis hyperactivity, normal thyroid function and blunted GH response to insulin-induced hypoglycemia at 90 min. in ITT in the depressive patients.

Adolescent↗
PubMed1991

Effectiveness of palladium matrix modification for the determination of thallium by graphite furnace atomic absorption spectrometry.

The effect of palladium matrix modification on the determination of thallium has been investigated. The effect of palladium combined either with ammonium nitrate or with magnesium nitrate on the sodium chloride interference was systematically studied and was compared with that of the classical sulfuric acid modifier. A combination of 6 micrograms palladium with 100 micrograms ammonium nitrate allows the direct determination of thallium in ten-fold diluted blood against matrix-free standards. The detection limit (3 sigma) in the undiluted blood was calculated to be 25 micrograms.1(-1). For the urine analysis the standard addition technique is recommended because a complete thallium recovery for all different urine samples studied was not always obtained.

Hot Temperature↗