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Biomedical subjects

Q Zhang

Publications and source records attributed to Q Zhang.

At least 883 records · Page 49Linked to original sources
PubMed1992

[Effect of the root of Polygonum multiflorum Thunb. and its processed products on fat accumulation in the liver of mice].

Experiments have shown that the root of Polygonum multiflorum exhibits inhibitory effect on triglyceride (TG) accumulation in the liver of mice induced by CCl4, cortisone acetate and thioacetamide (TAA). Its processed products (I, II) were found to be effective in lowering the accumulated TG induced by cortisone acetate. The root of Polygonum multiflorum and its processed products also reduced the enlargement of liver by CCl4.

Animals↗
PubMed1992

Retinoma and phthisis bulbi of retinoblastoma. 1. Clinical and genetic analysis.

Retinoma and phthisis bulbi of retinoblastoma are rare entities found in retinoblastoma patients and their relatives. Eleven cases of phthisis bulbi of retinoblastoma and 9 cases of retinoma were identified from 1966 to 1991 in our center. The clinic data show that retinoma and phthisis bulbi are closely related to the retinoblastoma gene. Enucleation should be carried out as soon as possible without hesitation for the phthisis of eyes with retinoblastoma. Genetic counseling and frequent observation should be paid attention to retinoma patients and their offspring. The mechanism of retinoma developed is discussed. We propose that the diversity of second mutation might be the cause of retinoma.

Adult↗
PubMed1992

Prospective double-blind study of CEE3 in peri- and postmenopausal women: effects on bone loss and lipoprotein lipids.

A prospective double-blind study was carried out in 136 women 0.5 to 21 years since menopause (YSM) in order to demonstrate the effects of a long-acting estriol derivative-Nylestriol (CEE3) on bone loss and lipoprotein lipids. They were orally administered at 2 mg of CEE3 or placebo every 2 weeks. Among 90 subjects who finished 1 year of medication, 49 received CEE3 and 41 placebo. The results were: 1. Serum ALP, Ca/Cr and Hop/Cr in fasting urine decreased in 3 months (P < 0.05); 2. Menopause-related reduction of forearm bone density was restrained; 3. LDL-C decreased in 3 months and HDL-C increased in 6 months (P < 0.05), with no significant changes in TC and TG; 4. Side effects were mild. 1/3 of those with intact uterus had spotting and another 1/3 had moderate withdrawal bleeding after the addition of medroxyprogesterone acetate at the end of 12 months of CEE3 therapy. This study demonstrates that CEE3 is effective and acceptable for preventing osteoporosis and lipoprotein lipids disorder in postmenopausal women. Long-term application awaits further studies.

Administration, Oral↗
PubMed1992

[A correlative study on post-stroke depression and CT, physical, psychological and social parameters].

58 acute hospitalized CVD patients were selected as study group. Each patient was administered a series of standardized quantitative measures. As a result, we found a significant difference between hemisphere (L: 55% vs R: 28% P < 0.05), and the difference was result from the highest incidence rate of PSD observed in the left anterior CVD subgroup. Meanwhile, those with left anterior lesion (cortical and subcortical) had the greater severity of depression than any other lesions. A strong negative correlation between the severity of depression and AP% was observed for left CVD group. The result of multiple stepwise regression analysis not only support the notions mentioned above but also shown up that a few factors other than location of the lesion had impact on the PSD. Finally, authors discussed the heterogenous causes of PSD and think probably biological etiology involved in the formation of PSD.

Brain↗
PubMed1992

Embryonic oxygen consumption and organ growth in the wedge-tailed shearwater.

Embryonic oxygen consumption and organ growth were measured in the Wedge-tailed Shearwater (Puffinus pacificus), a tropical seabird characterized by slow embryonic growth and a prolonged pipping process prior to hatching. In most organs, growth in unpipped eggs could be represented by a linear regression of organ mass on whole-embryo mass. However, the slopes of the regression lines varied considerably between organs. The slope was steepest for the stomach and lowest in the heart and lungs. Oxygen consumption also increased linearly with embryo mass up to 25g in unpipped eggs, until just prior to pipping. In pipped eggs, however, there was a considerable increase in oxygen consumption, and acceleration of growth in some organs (eg. liver, intestine) while in others (eg. stomach, pectoral muscles, eyeballs) growth rates diminished. Comparison with the reported growth of other species revealed a number of similarities between the embryos of the semi-precocial shearwater and the precocial domestic fowl, together with several differences between the shearwater and the altricial pigeon embryo.

Animals↗
PubMed1991

Effects of surface amino acid replacements in cytochrome c peroxidase on complex formation with cytochrome c.

Site-directed mutagenesis was employed to examine the role played by specific surface residues in the activity of cytochrome c peroxidase. The double charge, aspartic acid to lysine, point mutations were constructed at positions 37, 79, and 217 on the surface of cytochrome c peroxidase, sites purported to be within or proximal to the recognition site for cytochrome c in an electron-transfer productive complex formed by the two proteins. The resulting mutant peroxidases were examined for catalytic activity by steady-state measurements and binding affinity by two methods, fluorescence binding titration and cytochrome c affinity chromatography. The cloned peroxidases exhibit similar UV-visible spectra to the wild-type yeast protein, indicating that there are no major structural differences between the cloned peroxidases and the wild-type enzyme. The aspartic acid to lysine mutations at positions 79 and 217 exhibited similar turnover numbers and binding affinities to that seen for the "wild type-like" cloned peroxidase. The same change at position 37 caused more than a 10-fold decrease in both turnover of and binding affinity for cytochrome c. This empirical finding localizes a primary recognition region critical to the dynamic complex. Models from the literature proposing structures for the complex between peroxidase and cytochrome c are discussed in light of these findings.

Amino Acids↗
PubMed1991

Regulation of transformation-sensitive secreted phosphoprotein (SPPI/osteopontin) expression by transforming growth factor-beta. Comparisons with expression of SPARC (secreted acidic cysteine-rich protein).

Secreted phosphoprotein I (SPPI; osteopontin), a highly phosphorylated form of which has been associated with cell transformation, is one of the major phosphorylated proteins in bone. Populations of rat bone cells derived from fetal calvariae, neonatal parietal bone and a rat osteosarcoma cell line (ROS 17/2.8) produce several forms of the protein, the major forms having apparent molecular masses of 55 and 44 kDa by SDS/PAGE on 15% (w/v) cross-linked gels and of 60 and 56 kDa on 10% gels. Northern blot analysis of SPPI mRNA using total cellular RNA revealed a single 1.5 kb mRNA species, indicating that the nascent protein chains of these phosphoproteins are identical. On treatment of the cells with transforming growth factor-beta (TGF-beta; 1 ng/ml), the levels of SPPI mRNA and the synthesis of the 55 kDa phosphoprotein, but not of the 44 kDa phosphoprotein, were increased by 1.8-4.5-fold in the normal osteoblastic cells, the stimulation first being evident at 3 h and reaching a maximum at 12 h. In the transformed ROS 17/2.8 cells, TGF-beta did not alter significantly the SPPI mRNA level or the synthesis of either the 55 kDa or the 44 kDa SPPI over the 24 h period studied. By comparison, neither the steady-state levels of SPARC (secreted protein, acidic, rich in cysteine) mRNA nor the synthesis of SPARC protein were affected significantly by the addition of TGF-beta to any of the osteoblastic bone cells. The half-lives for SPPI and SPARC mRNAs in the osteoblastic calvarial cells were calculated to be 18 h and greater than 50 h respectively, in both the presence and the absence of TGF-beta. Since the stability of the mRNA was unchanged by TGF-beta and the increased expression of SPPI mRNA could be blocked by cycloheximide, TGF-beta appears to increase transcription of the SppI gene indirectly by stimulating the synthesis of a protein that promotes transcription. These results demonstrate that several forms of SPPI are synthesized constitutively by bone cells, and that there are clear differences in the regulation of SppI gene expression by TGF-beta in normal bone cells compared with the tumorigenic ROS 17/2.8 cells. The differential responses of normal osteoblastic cells to TGF-beta in the expression of SPPI and the selective stimulation of specific forms of the SPPI protein may be important in bone repair and remodelling.

Animals↗
PubMed1991

Immunohistochemical localization of bone sialoprotein in foetal porcine bone tissues: comparisons with secreted phosphoprotein 1 (SPP-1, osteopontin) and SPARC (osteonectin).

Bone sialoprotein (BSP) is a prominent component of bone tissues that is expressed by differentiated osteoblastic cells. Affinity-purified antibodies to BSP were prepared and used in combination with biotin-conjugated peroxidase-labeled second antibodies to demonstrate the distribution of this protein in sections of demineralized foetal porcine tibia and calvarial bone. Staining for BSP was observed in the matrix of mineralized bone and also in the mineralized cartilage and associated cells of the epiphysis, but was not observed in the hypertrophic zone nor in any of the soft tissues including the periosteum. In comparison, SPP-1 (osteopontin) and SPARC (osteonectin), which are also major proteins in porcine bone, were observed in the cartilage as well as in the mineralized bone matrix. In addition, SPARC was also present in soft connective tissues. Although SPP-1 distribution was more restricted than SPARC, hypertrophic chondrocytes, periosteal cells and some stromal cells in the bone marrow spaces were stained in addition to osteoblastic cells. The variations in the distribution and cellular expression of BSP, SPARC and SPP-1 in bone and mineralizing cartilage indicate these proteins perform different functions in the formation and remodelling of mineralized connective tissues.

Animals↗
PubMed1991

Differential regulation of the 55 and 44 kDa forms of secreted phosphoprotein 1 (SPP-1, osteopontin) in normal and transformed rat bone cells by osteotropic hormones, growth factors and a tumor promoter.

Confluent cultures of rat bone cells synthesize several forms of secreted phosphoprotein 1 (SPP-1, osteopontin), the major phosphorylated forms of which migrate at 55 and 44 kDa on 15% cross-linked SDS-PAGE gels and correspond to the transformation-associated proteins pp 69 and pp 62. A clonal rat calvarial cell line (RCA 11), which expressed the highest level of SPP-1, produced only the 55 kDa form of the phosphorylated protein, whereas normal rat calvarial cells enriched in osteoblastic cells (RC IV cells) produced mostly the 55 kDa form, with small amounts of the 44 kDa form. In contrast, a 44 kDa form was the major [32PO4]-labelled SPP-1 synthesized by a rat osteocarcoma cell line (ROS 17/2.8 cells) with lesser amounts of the 55 kDa SPP-1. When [35S]methionine was used to measure protein synthesis, only the 55 kDa SPP-1 could be clearly detected in confluent cultures of each cell population, indicating that the 55 kDa SPP-1 is the prominent form of SPP-1 synthesized by each cell population. Following treatment of the normal rat bone cells for 24 h with osteotropic hormones (vit D3, PTH and RA), growth factors (PDGF, EGF, TGF-beta), a tumor promoter (TPA) and a plant lectin (Con A), the 55 kDa [35S]methionine labelled SPP-1 was increased 1.7-8.3-fold. Similar, but generally lower responses were observed in the clonal RCA 11 cell line, whereas the ROS 17/2.8 cells were more refractory, showing only a strong response to vit D3. In general, vit D3 produced the strongest stimulation in all populations with TGF-beta producing a good response in the non-transformed cells and RA in the RC IV cells. In contrast, PTH was inhibitory in both RCA 11 and ROS 17/2.8 cells. In most, but not all, cases the alteration in SPP-1 synthesis reflected similar changes in SPP-1 mRNA and in the intensity of the [32PO4]-labelled 55 kDa SPP-1. Collectively, these studies demonstrate that bone cells produce several forms of SPP-1 which are differentially regulated in normal and transformed cells through both transcriptional and posttranscriptional mechanisms.

Animals↗
PubMed1991

Biosynthesis of bone proteins by fetal porcine calvariae in vitro. Rapid association of sulfated sialoproteins (secreted phosphoprotein-1 and bone sialoprotein) and chondroitin sulfate proteoglycan (CS-PGIII) with bone mineral.

To study the biosynthesis of bone proteins, fragments of fetal porcine calvariae were cultured in the presence of 50 micrograms/ml ascorbate and 10 mM beta-glycerophosphate and individual cultures labeled for either 4 h or 48 h with [35S]-methionine, Na2[35SO4], Na3[32PO4] or [14C]-glycine plus [14C]-proline. The radiolabeled proteins in tissue extracts were obtained by sequential extraction with 4 M GuHCl (G1-extract), 0.5 M EDTA (E-extract), and again with 4 M GuHCl (G2-extract) and analyzed together with the radiolabeled proteins secreted into the medium. SPP-1 (secreted phosphoprotein 1, osteopontin) was the major non-collagenous protein deposited into the bone matrix, with lesser amounts of BSP (bone sialoprotein), osteocalcin and chondroitin sulfate proteoglycans (CS-PG II and CS-PG III). SPP-1 was also the major phosphorylated protein and was recovered, together with several fragmented forms, almost entirely in the demineralizing extracts. Moreover, approximately one-half of the [35SO4] incorporated into E-extract proteins was present in SPP-1, the remainder being incorporated into PGs with smaller amounts associated with BSP. Over 65% of the [35SO4] in the proteoglycans of the demineralizing extracts was recovered in the small CS-PG III with less than 35% in CS-PG II, the bone homologue of DS-PG II (decorin). In contrast, CS-PG II was the predominant small proteoglycan in culture media and in guanidine extracts. Some sulfated BSP was also observed in guanidine extracts and small amounts appeared to bind to collagen. Radiolabeled SPARC (osteonectin), a prominent protein of fetal porcine bone, was not detected in the mineralized bone tissues but was prominent in the culture medium. These results demonstrate that following secretion, the major proteins expressed by osteoblastic cells are initially incorporated into different tissue compartments, with most of the sulfated sialoproteins and CS-PG III associating rapidly with the hydroxyapatite crystals. The initial distribution of these proteins is of importance in the evaluation of their role in bone formation and mineralization.

Animals↗
PubMed1991

[Regulation of atrial natriuretic peptide receptor in cultured aortic vascular smooth muscle cells from stroke-prone spontaneously hypertensive and Wistar-Kyoto rats].

The specific binding sites for atrial natriuretic peptide (ANP) were present in cultured vascular smooth muscle cells (VSMC) from stroke-prone spontaneously hypertensive (SHRsp) and Wistar-Kyoto(WKY) rats with a Bmax of 3.65 +/- 0.13 and 1.89 +/- 0.09 pmol/mg pr. and a Kd of 72.0 +/- 10.2 and 42.1 +/- 4.8 x 10(-12) mol/L, respectively. The basal levels of cGMP of the two strains showed no statistical difference. After treatment with ANP (1.67 x 10(-7) mol/L) for 5 min, the cGMP levels of VSMC were increased by 139 folds in SHRsp and 271 folds in WKY rats, i.e., cGMP levels were significantly lower in the former (P less than 0.01). Therefore, the cultured VSMC of SHRsp had higher ANP receptor density but lower affinity and responsiveness to ANP than that of WKY rats. After incubation of VSMC in the medium containing high NaCl (2-folds of normal) at 37 degrees C for 24 h, the number of ANP binding sites decreased to 34.8 +/- 8.2% in SHRsp and to 38.6 +/- 9.4% in WKY rats (P less than 0.01) with a parallel decrease of cGMP, while the affinity of ANP receptor did not change. It is suggested that the lower responsiveness of ANP receptor to ANP in SHRsp might result in a diminution of vasorelaxation to ANP and thus an increase of arterial pressure. In addition, the more down-regulation of ANP receptor by high NaCl in cultured VSMC from SHRsp implicates that it is one of the mechanisms that high dietary intake of NaCl might enhance high blood pressure.

Animals↗
PubMed1991

[Bayesian and RFLP linkage analysis on a DMD family].

Three methods were applied to estimate the carrier risk of the daughter of an obligate carrier of the Duchenne gene in a pedigree of Duchenne muscular dystrophy (DMD). According to Mendel's law of segregation, the daughter (III-3) of the obligate carrier (II-2) has a 50% chance of being a carrier. III-3 is also found to have a normal value in a carrier test, creatine phosphate kinase (CPK), and so the Bayesian analysis in risk estimation shows that the posterior probability that she is a carrier (25%). The restriction fragment length polymorphism (RFLP) linkage analysis indicates that the probability that III-3 is a carrier less than 5%. This result can be included in the Bayesian analysis to give an even lower risk of less than 2%. Our study demonstrates that the best result of carrier risk estimation can be obtained by a simultaneous application of Mendel's law, RFLP linkage analysis and the Bayesian analysis.

Bayes Theorem↗
PubMed1991

[Determination of trace chloride and sulfate in drugs by ion chromatography].

Chloride and sulfate in magnesium trisilicate, activated charcoal, vesnarinone and bendazac were determined by the IC conductimetric detection. Analysis were performed by using a separating column (100 x 6 mm i.d.) packed with anion exchanger and with a stripper column (100 x 6 mm i.d.); 1.4 mmol/L Na2CO3 and 1.4 mmol/L Na2CO3-0.75 mmol/L NaHCO3 were used as eluents respectively. The peak height was linear with concentration from 10(-6) to 10(-3) mol/L for Cl- and from 10(-5) to 10(-3) mol/L for SO4(2-). Results showed no significant difference as compared with those determined by the CHP (1985) and CHP (1990) appendices methods. The IC method is specific, sensitive, simple and rapid.

Charcoal↗
PubMed1991

[Screening studies on anti-inflammatory function of traditional Chinese herb Gardenia jasminoides Ellis and its possibility in treating soft tissue injuries in animals].

This paper reports the study of six fractions and one chemical constituent isolated from the traditional Chinese herb Gardenia jasminoides. The results showed that two fractions (G5.G6,), alcohol extract (G1) and genipoiside(A) had obvious anti-inflammatory effects and were comparatively effective in treating soft tissue injuries in animals.

Animals↗