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Biomedical subjects

Q Pan

Publications and source records attributed to Q Pan.

At least 91 records · Page 5Linked to original sources
PubMed1997

[Quantitative analysis of prevention effect of tetrandrine on pancreatic islet beta cells injury in rats].

OBJECTIVE: To observe the preventive effect of tetrandrine (TET) on pancreatic islet beta cells damaged by alloxan in rats with HE, Gomori aldehyde fuchsine staining and immunocytochemistry. METHODS: Animal diabetic models were prepared with alloxan (50 mg/kg i.v.). Pancreatic islet beta cells density (BD) in the section of HRP-SPA immunocytochemistry staining was determined with weibel square system. RESULTS: The BD in experimental groups pretreated with TET (100 mg/kg) at 1.5 hours, 5 hours prior to alloxan injection increased from the control value of 13 +/- 4 to 62 +/- 9 and 65 +/- 7 (P < 0.001), which had no evident difference compared with the BV in normal control group; while the BV (22.5 +/- 7.7) in the pretreated group at 7 hours prior to alloxan injection also increased compared with the control group. But it was much lower than that in the normal control group. When the doses of TET decreased from 100 mg/kg to 50 mg/kg and 25 mg/kg, the BD declined from 62 +/- 9 to 45 +/- 5 and 38 +/- 4 (P < 0.01 and P < 0.001). CONCLUSION: Tetrandrine can protect islet beta cells a from injury induced by alloxan.

Alkaloids↗
PubMed1996

Duplications and deletions of the human IGHC locus: evolutionary implications.

A limited number of deletions and duplications within the human immunoglobulin heavy chain constant locus (IGHC) has previously been reported. We studied the IGHC locus in about 500 individuals representing three major races of human, Negroid (Gambian), Mongoloid (Japanese and Chinese), and Caucasoid (Iranian and Swedish). The haplotype frequency of duplications is highest in the Mongoloid population (22%), followed by the Caucasian (10%) and Negroid (5%) populations. The corresponding frequency of deletions are 2, 1.5, and 3.5%, respectively. New types of multiple duplications were found in this study on different genetic (H haplotype and racial) backgrounds. The most common duplication, found in all populations studied, encompasses the IGHA1-IGHE genes. The only deletion common to all racial groups is an isolated deletion of the IGHG4 gene. Our data are consistent with the hypothesis that the Caucasoid-Mongoloid group diverged from the hominoid ancestor after development of the Negroid populations, with subsequent evolution within the respective groups thereafter.

Electrophoresis, Gel, Pulsed-Field↗
PubMed1996

1,25-Dihydroxyvitamin D3-regulated binding of nuclear proteins to a c-myc intron element.

The steroid hormone 1,25-dihydroxyvitamin D3[1,25-(OH)2D3] induces maturation of many cells, including HL-60 promyelocytic leukemia cells that are differentiated to monocytes/macrophages. This process involves changes in transcription of genes such as c-myc. We investigated the effects of 1,25-(OH)2D3 on nuclear protein binding to the c-myc intron element (MIE), a region of DNA within the c-myc gene. A mutation in this MIE sequence has been shown to be associated with uncontrolled expression of the c-myc gene in various cell lines. In this report, we demonstrate for the first time that 1,25-(OH)2D3 induces increased binding of nuclear proteins to this MIE in HL-60 cells. The major MIE-binding proteins were approximately 32 kDa in size. Interestingly, phorbol 12-myristate 13-acetate induced a similar increase in binding of the 32-kDa doublet protein to the MIE. In addition, we showed that the level of 138-kDa MIE-binding protein was increased by 1,25-(OH)2D3 and phorbol 12-myristate 13-acetate. However, the extent of MIE binding by the 138-kDa protein is significantly less than that of the 32-kDa doublet binding species. MIE binding by the 32-kDa doublet protein was significantly increased within 12 h of 1,25-(OH)2D3 treatment. The time course of this increase was similar to that of 1,25-(OH)2D3-induced inhibition of c-myc gene transcription. We also demonstrated that dephosphorylation of the 32-kDa doublet protein inhibited its binding to the MIE. Thus, this study shows that the mechanism employed by 1,25-(OH)2D3 for regulation of c-myc expression may involve an increase in protein binding to the MIE, which has been shown to be the site for control of c-myc gene expression.

Alkaline Phosphatase↗
PubMed1996

[Study of chromosome painting for one rare carrier with complex translocation].

This paper reports that one rare male carrier with complex translocation, being married for eight years, made his wife consecutive seven times abortions, stillbirth and teratogenesis of early death. Using human chromosome 7 and 8-specific probe pools constructed with the technique of chromosome microdissection and PCR, we carried out chromosome painting research of the patients, and identified the karyotype was: 46, XY, -7, -8, -9, +der (7)t(7; 9) (q2200; p24), +der(8)inv ins(8; 7) (q2100; q31.2q2200), +der (9)t(9; 7) (p24; q31.2).ish der(7)t(7; 9) (wcp7+), der(8)inv ins(8; 7)(wcp7+, wcp8+), der(9)t(9; 7) (wcp7+). The technique of chromosome painting provided us an effective technique of molecular cytogenetics for the study of chromosomal abnormalities. The formation mechanism of the complex translocation of the carrier is discussed.

Adult↗
PubMed1996

[Identification of the origin of 7q+ marker chromosome in a mental retard patient].

The present chromosome-specific and chromosome-band-specific probe pools constructed by the technique of human chromosome microdissection and PCR were taken as painting probes. Using the forward chromosome painting and chromosome screening method, we had identified a chromosome additional fragment of a 7 q+ marker chromosome in a patient originated from 3 q 26-->3 qter, and ascertained the patient's karyotype was 46, XX, -7, + der (7) t (7;3) (7 pter-->7 q 32::3 q 26-->3 qter). Applying this strategy, we can identify the origin of marker chromosomes fastly and effectively.

Child↗
PubMed1996

[Combined effects of high temperature and carbon monoxide on heat stress protein levels in rat brain and viscera].

Combined effects of high temperature and carbon monoxide (CO) on the amounts of heat stress protein 60 (HSP 60) and 70 (HSP 70) in rat brain and viscera were studied by western dot blot technique. Results showed that (1) amounts of HSP 60 in rat brain, spleen and kidney, as well as its rectal temperature, increased with CO concentrations, while those in heart decreased; and both of them showed synergistic effects on those in spleen and kidney, antagonistic ones in brain and liver, and synergistic ones of lowering them in heart; (2) amounts of HSP 70 changed with CO concentrations in five rat viscera, with synergism in brain, and antagonism in other organs; and (3) amounts of HSP 60 and 70 in most rat viscera and their body temperature were the most sensitive to 693.6 mg/m3 of CO.

Animals↗
PubMed1995

Genetics of IgA deficiency.

IgA deficiency is the most common humoral defect in man and results in an increased susceptibility to respiratory tract and gastrointestinal infections. Both clinical and genetic data support a close relationship with common variable immunodeficiency, a disease which involves not only IgA and IgG production, but also, in half of the patients, IgM. It is likely that the two disorders represent an allelic condition with a variable expression of a common gene defect which is thought to be involved in the regulation of immunoglobulin class switching. It is possible that a single, autosomally inherited gene with a limited penetrance is responsible for the development of both these defects.

Gene Expression Regulation↗
PubMed1995

[Reduced intracellular drug accumulation related to overexpression of P-glycoprotein cannot explain the complete drug resistance in MDR cell variant K562/Dox].

The purpose of this study was to determine what proportion of drug resistance of MDR cell variant K562/Dox was attributed to the reduced steady state intracellular drug accumulation related to overexpression of P-glycoprotein. K562/Dox was derived from repeated exposure of human erythroleukaemic cell line K562 cell to doxorubicin. As assessed with MTT assay, the resistance of K562/Dox to 7 cytotoxic drugs increased variably in the range between 1200 and 11 folds. K562/Dox cells were positively stained with anti-human p-glycoprotein monoclonal antibody JSB-1, indicating overexpression of P-gp. Intracellular drug accumulation in K562/Dox, though significantly reduced as compared with that in K562 cells, was maximally restored by concurrent exposure of cells to 6 mumol/L verapamil and 1.72 mumol/L either of the doxorubicin, epirubicin or daunorubicin. Similar results were obtained by exposure of cells to 12 mumol/L verapamil and 8.62 mumol/L drug, indicating that restoration of intracellular drug accumulation in MDR cells was dependent on the relative concentrations of verapamil to drug. However, the resistances of K562/Dox cells to epirubicin and daunorubicin still remained for about 5.6 and > 6.6 folds, respectively, even at verapamil concentration of 6 mumol/L, suggesting at least a relatively big fraction of drug resistance was not directly related to the altered cellular pharmacokinetics associated with overexpression of P-glycoprotein.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed1995

[Analysis of heavy chain immunoglobulins gene and T-cell receptor delta gene in children with acute leukemia].

IgH gene, TCR delta gene rearrangements and Tal-1 gene deletion were analysed by using PCR, Southern blot and DNA sequencing methods in newly diagnosed BM samples from children with AL. The DNAs from leukemic cells in 102 children were detected with PCR. The results showed that IgH gene rearrangement mainly occurred in B Precursor ALL (37/49). Six PCR products were further analysed by DNA sequencing. Less homogene and bias of JH gene usage were found in analysed DNA sequences. V delta 2-D delta 3 rearrangement of 78 samples from ALL was analysed with PCR method. V delta 2-D delta 3 rearrangements mainly observed in B precursor ALL and related HAL. V delta 2-D delta 2-N-D delta 3 rearrangement was found in a sequence of PCR product. Three cases of Tal-1 gene deletion were observed in all studied 70 samples of AL. They all were in stage I of thymus differentiation. We conclud that PCR detection of those genes are useful in the diagnosis of clonality of AL, DNA sequencing of PCR products is the base of preparing clonal specific probes, and dynamic analysis of IgH gene rearrangement using PCR may be helpful in detection of residual clones.

Child↗
PubMed1995

[Chemical constituents of Hemsleya pengxianensis W.J. Chang].

Six compounds were isolated from the tubers of Hemsleya pengxianensis and identified as chikuset-susaponin IV a, hemslosides Ma1, G1, H1, dihydrocucurbitacin F-25-O-acetate and dihydrocucurbitacin F on the basis of chemical and physical properties and spectral data. They were all isolated from this plant for the first time.

Drugs, Chinese Herbal↗
PubMed1993

Lesions of the hippocampus enhance or depress humoral immunity in rats.

The effect on the humoral immune response in rats by bilaterally destroying cell bodies in the hippocampus with kainic acid or by electrolytic lesion was studied. After 3 days a humoral immune response was evoked by injecting 1 ml of 10% sheep red blood cells. Five days later, the haemolysin content (MC50) was measured. Chemical destruction of pyramidal cell bodies in CA2 and CA3 significantly increased humoral immunity as measured by HC50, but larger chemical lesions that also included CA1 did not. Electrical destruction of cell bodies and axonal pathways in CA2 and CA3 did not significantly affect HC50. These results suggest that different areas of the hippocampus can stimulate or inhibit humoral immunity.

Animals↗
PubMed1991

[An experimental study on acupoint neiguan-heart short reflex].

It is reported that the dichotomizing afferent fibers supply both the pericardium and the brachium in rat. This finding provides a possible morphological explanation for short reflex which transmits messages only through the connection of peripheral nerve dichotomization. The animals utilized in this study were 15 male or female wistar rats (235-360 g). Rats were anesthetized with 26% urethane (100mg/100g b. wt, i.p.) and then, acute myocardial ischemia (AMI) was produced by pituitrin (1.0-1.5 u/a rat, i.M.). Following anesthetization and AMI, The I lead of electrocardiogram (ECG) was recorded, the superficial electrical resistance and cutaneous temperature of the acupoint Neiguan and Zusali were measured. In order to break off the long reflex which invokes some effects through central nervous system, the dorsal roots were removed of spinal cord segments cervical 6) C6-thoracic 1(T1). In this condition, the AMI can decrease in superficial electrical resistance and cutaneous temperature of the acupoint Neiguan (P less than 0.01). Acupuncture at Neiguan can also influence the superficial electrical resistance of the acupoint Neiguan, improve in the ECG, increase in the heart rate, but acupuncture at Zusali has no these effects. It suggests that acupoint Neiguan and heart can be connected through a short reflex.

Acupuncture Points↗