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S Jiao

Publications and source records attributed to S Jiao.

At least 37 records · Page 2Linked to original sources
PubMed1996

Efficient and sustained transgene expression in mature rat oligodendrocytes in primary culture.

In order to evaluate the characteristics and efficiency of gene transfer in primary cultures of oligodendrocytes, four different techniques including particle bombardment (Accell gene gun), cationic liposome-mediated transfection (lipofection), calcium phosphate co-precipitation and retroviral infection were compared using the LacZ and luciferase reporter genes. Highly purified postnatal adult rat oligodendrocytes were obtained by sequential immunopanning, plated in culture, and transfected using various reporter and promoter genes. The most efficient expression of LacZ and luciferase genes was found with particle mediated gene delivery. The transgene expression level obtained with gene gun delivery was at least two- to 100-fold greater than three other tested gene transfer methods. Comparison of the relative strength of four viral and two cellular promoters in these primary oligodendrocytes cultures demonstrated that the CMV promoter was the strongest. Using a human growth hormone (hGH) reporter gene, a long-term transgene expression pattern in primary oligodendrocytes was demonstrated to be sustained in culture for the entire experimental period (4 weeks) after particle-mediated gene transfer. These results demonstrate that expression of a foreign gene can be effectively achieved in primary cultures of adult oligodendrocytes, especially by using the particle bombardment method. The results also suggest that the current ex vivo gene transfer system may be used to manipulate oligodendrocytes for future application in gene therapy studies.

Adenoviridae↗
PubMed1996

[A study on DNA content and cell cycle phase analysis in endometrial carcinoma].

OBJECTIVE: To study the prognostic value of DNA content, cell cycle phase in endometrial carcinoma. METHODS: DNA content and cell cycle phase analysis were performed on 100 paraffin-embedded archival specimens from 103 cases of endometrial carcinoma using flow cytometry. RESULTS: Aneuploidy was found in 71.0% of specimens. The aneuploidy rate in specimens from grade III, deep myometrial invasion and stage III, IV was significantly higher than that in specimens from grade I, nonmyometrial invasion and stage I (P < 0.05 respectively). 5-year survival rate for patients with aneuploidy was 65.9% and for patients with diploidy was 87.6% (P < 0.01). High S-phase fraction (SPF) was associated with high grade, deep myometrial invasion and advanced stage. The mean SPF was 13.4% in the living group and 17% in the dead group. The 5-year survival rate for patients with SPF > 17% was 50.4% and for patients with SPF < 17% was 79.1% (P < 0.01). SPF and stage were the most important prognostic factors in endometrial carcinoma by Cox's proportional hazards model. CONCLUSIONS: DNA ploidy and SPF were found to be of important prognostic indicators in endometrial carcinoma.

Adenocarcinoma↗
PubMed1995

Increased proportion of plasma apoB-48 to apoB-100 in non-insulin-dependent diabetic rats: contribution of enhanced apoB mRNA editing in the liver.

To assess the alteration of apolipoprotein (apo) B mRNA editing in non-insulin-dependent diabetes mellitus (NIDDM), we measured plasma apoB-100 and apoB-48 levels and apoB mRNA editing efficiency in the liver and intestine from GK (Goto-Kakizaki) rats, a genetically NIDDM animal. Male GK rats and control littermates, aged 25 weeks, were used in this study. Ventromedial hypothalamus (VMH)-lesioned control rats were used as hyperinsulinemic models. VMH-lesioned GK rats (GK+VMH) were treated as an insulin-exhausted NIDDM model. Plasma cholesterol and triglyceride levels were increased in GK rats. Very low density lipoprotein (VLDL)-triglyceride and low density lipoprotein (LDL)-cholesterol concentrations were significantly higher in GK rats than in controls. The increase of VLDL-triglyceride was most marked in GK+VMH rats. Plasma apoB-48 levels, quantified by immunoblot, were increased in GK rats. However, apoB-100 levels were minimally elevated in GK rats. Therefore, the apoB-48/apoB-100 ratio was remarkably increased in GK rats. ApoB mRNA editing was analyzed by reverse transcriptase-polymerase chain reaction coupled with dideoxynucleotide chain termination assay. The ratio of apoB-48-type cDNA to apoB-100-type cDNA was significantly increased in the liver from GK rats compared with controls. Although the development of the VMH lesion increased plasma apoB-48 levels, it had no effect on the proportion of apoB-48-type to apoB-100-type cDNA in the liver from both GK and control littermates. ApoB mRNA in the intestine was almost totally edited (approximately 95%). Intestinal apoB-48/apoB-100 cDNA ratio showed no significant difference among the four groups. In conclusion, an enhanced apoB mRNA editing was indicated in the non-insulin-dependent diabetic rats, which might contribute to the increase of plasma apoB-48 levels.

Animals↗
PubMed1995

[A study on expression of tumor suppressor gene p53 in endometrial carcinoma].

OBJECTIVE: To observe the relationship between suppressor gene p53 expression and endometrial carcinoma. METHODS: Expression of p53 was studied by immunohistochemistry in paraffin sections from 23 normal endometrium, 44 endometrial hyperplasia and 103 endometrial carcinoma. RESULTS: Immunohistochemical staining of p53 protein was negative in normal and hyperplastic endometrium but positive in 47.6% of endometrial carcinoma. In endometrial carcinoma, p53 over expression was significantly associated with histologic type, tumor grade, presence of vascular invasion and DNA aneuploidy. The survival rate of patients with p53 expression is significantly lower than that of patients without p53 expression (P < 0.001), the 5-year survival rate is 59.9% and 83.4% respectively. Patients with expression of mutant forms of the tumor suppressor gene p53 products had a 6.34-fold increased risk of death as compared with patients without p53 expression by Cox proportional hazards model. CONCLUSIONS: Aberrant expression of p53 gene is indicative of aggressive biological behavior and poor survival in endometrial carcinoma.

Adenocarcinoma↗
PubMed1994

Induction of specific tolerance by intrathymic injection of recipient muscle cells transfected with donor class I major histocompatibility complex.

Induction of tolerance to allogeneic MHC antigens has been a goal in the field of transplantation because it would reduce or eliminate the need for generalized immunosuppression. Although encouraging results have been obtained in experimental models by exposing recipient thymus to donor cells before transplantation, donor cells are not typically available at that time, and the donor antigens responsible for the effect are poorly defined. In the present study, thymic tolerance was demonstrated without using donor cells. Recipient thymus was injected before transplantation with autologous myoblasts and myotubes that were genetically modified to express allogeneic donor-type MHC class I antigen. Donor-specific unresponsiveness was induced to a completely MHC-disparate liver transplant and to a subsequent donor-type cardiac allograft, but not a third-party allograft. In vitro, recipient CTL demonstrated a 10-fold reduction in killing of donor cells, but not of third-party cells. Our results demonstrate: (1) that recipient muscle cells can be genetically engineered to induce donor-specific unresponsiveness when given intrathymically, and (2) transfected recipient cells expressing only donor MHC class I antigen can induce tolerance to a fully allogeneic donor.

Animals↗
PubMed1994

Structure and function of selectable and non-selectable transgenes in maize after introduction by particle bombardment.

Zea mays transformants produced by particle bombardment of embryogenic suspension culture cells of the genotype A188 x B73 and selected on kanamycin or bialaphos were characterized with respect to transgene integration, expression, and inheritance. Selection on bialaphos, mediated by the bar or pat genes, was more efficient than selection on kanamycin, mediated by the nptII gene. Most transformants contained multicopy, single locus, transgene insertion events. A transgene expression cassette was more likely to be rearranged if expression of that gene was not selected for during callus growth. Not all plants regenerated from calli representing single transformation events expressed the transgenes, and a non-selectable gene (uidA) was expressed in fewer plants than was the selectable transgene. Mendelian inheritance of transgenes consistent with transgene insertion at a single locus was observed for approximately two thirds of the transformants assessed. Transgene expression was typically, but not always, predictable in progeny plants--transgene silencing, as well as poor transgene transmission to progeny was observed in some plant lines in which the parent plants had expressed the transgene.

Cells, Cultured↗
PubMed1994

Familial hypercholesterolaemia-like syndrome with apolipoprotein E-7 associated with marked Achilles tendon xanthomas and coronary artery disease: a report of two cases.

We observed two patients with hypercholesterolaemia and tendon xanthomas associated with apolipoprotein (apoE-7) E-7, a rare variant of the apoE isoforms. Both suffered from coronary artery disease and had undergone a coronary bypass operation. Their cholesterol levels were 268 and 310 mg dl-1, respectively. Both patients had marked xanthomas in the Achilles tendons. Both also suffered from diabetes. Although their clinical and laboratory findings were compatible with typical familial hypercholesterolaemia (FH), the analysis of low-density lipoprotein (LDL) receptors in cultured fibroblasts showed no abnormality of binding, internalization or degradation of 125I-LDL. Diabetic control with a low-calorie, low-fat diet led to the rapid reduction of serum cholesterol. Other family members of the patients with apoE-7, who were normoglycaemic, showed normal cholesterol levels and no xanthomas. These findings suggest that coexistent diabetes mellitus may induce overt hyperlipidaemia and accumulation of lipids in tissues in subjects with apoE7.

Achilles Tendon↗
PubMed1994

Pharmacological enhancement of in vivo foreign gene expression in muscle.

Intramuscular injection of naked plasmid DNA provides a means for gene transfer and expression in striated muscle. In this study, the effects of treating muscle with normal saline, etidocaine, mepivacaine, acetic anhydride, sodium bicarbonate, Notechis scutatus venom, cardiotoxin and bupivacaine before plasmid DNA injection on foreign gene expression were evaluated. Dose dependence, strain and species specificity, the time interval between pharmacological agent and plasmid DNA injection, the stability of gene expression and the fate of the injected plasmid DNA were studied using reporter gene expression, by histological examination and semi-quantitative polymerase chain reaction. Of the various agents tested, the best enhancement of foreign gene expression occurred in muscle treated with 0.75% bupivacaine five to seven days before plasmid DNA injection. Rat and mouse quadriceps muscle treated with 0.75% bupivacaine had levels of luciferase activity four- to 40-times greater than non-bupivacaine-treated muscle. Also, beta-galactosidase expressing myofibers were observed throughout the length of the muscle in samples treated with 0.75% bupivacaine before reporter gene injection. Muscle treated with 0.75% bupivacaine fully recovered from the degeneration caused by its injection with no long-term effects histologically. The heightened level of reporter gene expression persisted in 0.75% bupivacaine-treated muscle for one month, but decreased to that of non-bupivacaine-treated muscle by two months after plasmid DNA injection. Enhancement of foreign gene expression may be particularly advantageous in vaccination protocols employing intramuscular plasmid injection.

Acetic Anhydrides↗
PubMed1993

Long-term correction of rat model of Parkinson's disease by gene therapy.

The implantation of cells genetically modified to express tyrosine hydroxylase has been proposed for the treatment of Parkinson's disease. Tyrosine hydroxylase converts tyrosine to L-DOPA and endogenous decarboxylase activity then converts L-DOPA to the neurotransmitter dopamine, which alleviates the symptoms of Parkinson's disease. Immortalized cells have been successfully used as intracerebral vehicles for transgene expression of tyrosine hydroxylase, but the tumorigenic potential of these cells prevents their application in humans. Intracerebral expression of this enzyme has also been achieved using primary cells like skin fibroblasts, but the ameliorating effect on a rat model for Parkinson's disease lasted for only a few weeks. We have found that co-transplantation of cultured myoblasts and myotubes enabled reporter genes to be expressed intracerebrally at high and stable levels. Here we show that the intracerebral transplantation of plasmid-transfected primary muscle cells can substantially reduce for the long-term the asymmetric rotational behaviour in the rat model.

Animals↗
PubMed1993

Particle bombardment-mediated gene transfer and expression in rat brain tissues.

We have previously demonstrated that the particle bombardment method for gene transfer (Accell) provides a new means for transfection of various cell types in culture. In this study we evaluate its application to rat brain systems. Using a luciferase (luc) gene as a reporter, we obtained high levels of transient gene expression in primary cultures of fetal brain tissue. Reduced but significant levels were also detected in adult brain primary cultures. Both neuron and glial cells were transfected using this technique. The transient gene expression level obtained with Accell was at least 100-fold higher than that obtained with three other gene transfer methods. The relative strengths of four cellular and seven viral promoters were also evaluated in these cultures. In vivo gene expression was studied using freshly excised and bombarded fetal brain tissues which were immediately transplanted into caudate or intracortical brain tissues of adult host animals. Assays showed that luciferase activity was present in transplants for up to two months following gene transfer. In vitro and in vivo expression of a rat tyrosine hydroxylase (TH) gene, a candidate gene for treatment of Parkinson's disease, was also detected in this rat brain system. Our results suggest that the particle bombardment gene transfer technology can be employed as an effective method for ex vivo gene transfer into brain tissues.

Animals↗
PubMed1993

Marked reduction of acyl-CoA synthetase activity and mRNA in intra-abdominal visceral fat by physical exercise.

Several reports have suggested that the reduction of intra-abdominal visceral fat after physical exercise is more prominent than that of subcutaneous fat. We compared some parameters in mesenteric and subcutaneous fats between sedentary and exercised rats (treadmill running; 10-20 m/min, 60 min/day, 7 days). Tissue weight and cell volume were decreased in mesenteric fat by the exercise. The exercise reduced activity and mRNA levels of acyl-CoA synthetase (ACS; 67 and 26% of those of the sedentary group, respectively), mRNA levels of lipoprotein lipase (LPL; 49% of those of the sedentary group), and GLUT-4 (38% of those of the sedentary group) in the mesenteric fat. In contrast, all of these parameters did not change significantly in the subcutaneous fat. Gastrocnemius muscle was heavier in exercised rats. ACS activity was elevated in the gastrocnemius muscle of the exercised rats (137% of those of sedentary group), although mRNA levels of ACS, LPL, and GLUT-4 did not change in the muscle by the exercise. These observations suggest that mesenteric fat may contribute to switching of distribution of plasma energy flux, including lipid and glucose, from fat tissue to muscle in physical exercise.

Abdomen↗
PubMed1993

Co-transplantation of plasmid-transfected myoblasts and myotubes into rat brains enables high levels of gene expression long-term.

We have previously proposed the use of primary muscle cells as a "platform," or "vehicle" for intracerebral transgene expression. Brain grafts of minced muscle, or cultured muscle cells persisted in rat brains for at least 6 mo without any decrease in graft size, or tumor formation. Stable, but moderate levels of intracerebral transgene expression were obtained by transplanting plasmid-transfected myotubes in culture. In the present study, high and stable levels of intracerebral transgene expression were achieved by the co-transplantation of plasmid-transfected myoblasts and myotubes in culture. Approximately 5 X 10(5) myoblasts and myotubes were transfected with 10 micrograms pRSVL plasmid DNA, and 30 micrograms Lipofectin (BRL), respectively. They were mixed together (total cell number was 1 million), and stereotactically injected into the caudate nucleus of an adult rat brain. The activity of luciferase, the product of transgene expression, was stable for at least 4 mo, and much higher than the levels in myotube grafts, or co-grafts of myoblasts and minced muscle. Presumably, the myotubes served as a framework on which the myoblasts can form myotubes. The sections of brains transplanted with co-graft of myoblasts, and myotubes transfected with pRSVLac-Z were stained immunofluorescently for beta-galactosidase activity. The muscle grafts contained beta-galactosidase positive myofibers 4 mo after transplantation. Such high and stable levels of in vivo expression after postnatal gene transfer have rarely been achieved. Primary muscle cells are useful vehicle for transgene expression in brains, and potentially valuable for gene therapy of degenerative neurological disorders.

Animals↗