[The protection effect of selenium on the early ischemic rabbit myocardium].
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Animals↗
Biomedical subjects
J Ding
Publications and source records attributed to J Ding.
Orientation and expression of the cloned hemolysin gene of Pseudomonas aeruginosa.
The structural gene for Pseudomonas aeruginosa hemolysin, carried on recombinant plasmid pSL2 and cloned in Escherichia coli, was analyzed by insertional and deletional mutagenesis. Expression of the hemolysin was blocked by insertion of transposon Tn5 into different locations. Two of the mutants allowed detectable synthesis of truncated hemolysin polypeptides of two different sizes and thus defined the structural gene. The location of the hemolysin gene in the recombinant plasmid, and the direction of transcription, were further established by nuclease BAL 31 digestion, and by construction of gene fusions between hemolysin and beta-galactosidase. Evidently, the tet promoter contributed to the majority of the expression of cloned hemolysin gene, but the Pseudomonas promoter was present in the cloned DNA and was functional in E. coli since inactivation of the tet promoter either by Tn5 insertion or by deletion decreased synthesis of the 80-kDal hemolysin but did not fully abolish it.
Chromosome Mapping↗
[On the development and application of tools for grinding crude drugs in ancient China] (Chi).
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China↗
Preparation and crystallization of a complex between human adenovirus serotype 2 proteinase and its 11-amino-acid cofactor pVIc.
Crystals have been obtained of the recombinant human adenovirus serotype 2 proteinase (AVP) in a complex with its 11-amino-acid cofactor pVIc. AVP-pVIc complexes were formed by the incubation of AVP with a 1.2-fold molar excess of pVIc prior to the crystallization trials. Diffraction-quality crystals were obtained at 18 degrees C by the vapor-diffusion method with 5.6 mg/ml AVP-pVIc in 1.4 M sodium acetate and 0.1 M Hepes, pH 7.5. Diffraction data (99% complete to 2.6 A resolution with Rmerge of 0.077) were collected from native crystals at room temperature at beamline X12-C at the National Synchrotron Light Source. The crystals belong to space group P6(1) with unit cell dimensions a = b = 114.2 A, c = 50.1 A; alpha = beta = 90 degrees, gamma = 120 degrees. The unit cell dimensions and likely mass of the molecular species in the crystals were consistent with there being one 25,000-Da complex (1:1) per asymmetric unit. Additionally, one heavy-atom derivative, obtained by the soaking of preformed crystals, was isomorphous to the native crystal. Diffraction data obtained on these crystals were 95% complete to 3.0 A resolution with an Rmerge of 0.076. Difference-Patterson analysis indicates three heavy atom sites in the derivative asymmetric unit.
Crystallization↗
Atrial natriuretic factor (ANF) gene expression in the Brattleboro rat.
Atrial natriuretic factor (ANF) is a 28-amino acid peptide hormone of cardiac origin. It has natriuretic, diuretic and vasorelaxant properties and inhibits several cardiovascular modulators. Because of the possible effects of arginine vasopressin (AVP) on ANF secretion, we have investigated ANF gene expression in Brattleboro rats which are genetically deficient in AVP. Our results indicate that cardiac ANF mRNA and ANF content are higher in Brattleboro rats compared to Long-Evans controls, whereas the plasma levels are similar in both groups. Typical secretory granules containing immunoreactive ANF are present in ventricular cardiocytes of Brattleboro but not of Long-Evans rats. These data suggest that ANF release may be uncoupled from its synthesis in the absence of AVP.
Animals↗
The dynamic distribution of fluoro-gold and its interrelation with neural nitric oxide synthase following intracerebroventricular injection into rat brain.
We mapped the dynamic distribution of fluoro-gold (FG) within rat brain following intracerebroventricular (icv) injection into the lateral ventricle and observed its interrelation with neural nitric oxide synthase (nNOS) using FG fluorescent microphotography combined with nNOS immunohistochemistry. We also detected the amount of icv administered FG entering the peripheral circulation using a fluorescence microplate assay. The degree of periventricular penetration of FG was significantly increased over time. At 2 min after icv injection, FG primarily labeled the choroid plexus in the lateral and third ventricles, with limited penetration into the ependyma and the subependyma of the same ventricles. Some FG/nNOS-double labeled cerebrospinal fluid-contacting neurons were observed in these ventricles as well. At 15 and 30 min, FG penetrated mainly into forebrain ventricular organs and parenchymal structures. Many FG/nNOS double labeled neurons were found at each of these sites. In addition, at 30 min intense FG labeling was found in the hypophysis, while limited periventricular penetration of FG was detected in the hindbrain circumventricular areas. In the peripheral circulation, a low concentration of FG was detected 2 min after icv injection. The concentration increased slowly, peaked at 20 min, then gradually decreased until the end of the experiment at 30 min. These findings indicate that dynamic penetration of icv administrated agents into the periventricular tissues and peripheral circulation should be considered when designing icv experiments.
Animals↗
A clinically relevant orthotopic implantation nude mouse model of human epithelial ovarian cancer--based on consecutive observation.
The aim of this study is to establish an orthotopic implantation nude mouse model of epithelial ovarian cancer (EOC) and observe its biologic features. A human ovarian tumor line SKOV3ipl previously grown subcutaneously was implanted orthotopically as intact tissue into the ovarian capsule of 64 nude mice. Every week eight mice were taken randomly, and the tumor growth pattern and extent of metastatic disease were monitored continuously. Those mice that died of disease were necropsied and the end date was recorded. The orthotopic implanted tumors demonstrated a 100% take rate. Three weeks after implantation the tumors grew fast and weighed 1149 +/- 152 mg, and 5 weeks after implantation the tumors reached a flat stage. The tumors metastasized more often to peritoneum (32/56) and diaphragm (18/56), then to pelvic lymph nodes (11/56) and lung (10/56), and then to the seldom invaded organs including the pancreas, the liver, the contralateral ovary, and the para-aortic lymph node. Eight nude mice became exhausted 7 weeks after implantation and died within 68 days after implantation. Our study, utilizing the SKOV3ipl cell, is the first model of consecutive observation of the process of invasion and metastasis of EOC. It should be useful in understanding the molecular biology of EOC and in the development of therapeutic modalities against metastasis.
Animals↗
Effect of anti-cancer drugs on the binding of 125I-Fibrinogen to two leukaemia cell lines in vitro.
Anti-cancer drugs may be able to inhibit tumour growth and metastasis by blocking fibrinogen- and/or fibrin-related pathways. To test this hypothesis, the effect of various anti-neoplastic drugs on the binding of 125I-Fibrinogen to two leukaemia cell lines, HL60 and P388, was investigated. All the drugs tested inhibited the binding of fibrinogen to leukaemia cells. This effect was particularly marked for drugs that act as inhibitors of protein synthesis. Since these anti-neoplastic drugs do not have anti-coagulant actions, these results provide evidence for the potential of targeting tumour fibrinogen as a new form of cancer chemotherapy.
Antineoplastic Agents↗
Tumor tissue recycling--a new combination treatment for solid tumors: experimental and preliminary clinical research.
Although H&H combination treatment (high active TIL and high sensitive drugs) as previously described to solid tumor patients is more efficient than single-agent treatments such as TIL adoptive immunotherapy, it has a short-term efficiency for the immune response to metastatic cancers. Currently, a new version of the combination of active and adoptive immune response was established. TILs, tumor vaccines and high sensitive drugs. The experimental results demonstrated that TILs from 49 cases (65%) were more than 1,000 expansion-fold and only 6 cases (24%) less than 500 fold. The peaks of TIL 3H-TdR cytotoxicity test from 35 of 64 TIL specimens were kept from 40 to 56 days. TIL phenotypes studied here indicated CD3 80 +/- 21%, CD4 37 +/- 21%, CD8 44 +/- 18% and HLA DR 69 +/- 24% after IL2 induction, in contrast, to CD3 20 +/- 12%, CD4 10 +/- 7%, CD8 11 +/- 3% and HLA DR 30 +/- 16% before induction. Thirty two of 75 cases were assayed using the chemosensitivity test. The distribution of positive rates for the chemosensitivity test were slightly different in different tumors regarding tissues in liver, lung, ovary, breast, and melanoma, 2 cases with melanoma all showed negative results. The results of a tumor vaccine using TNF-alpha gene transduction demonstrated that the expression of HLA Class I and HLA Class II were dramatically increased 87% and 43%. After implanting tumor cells via transduced TNF-alpha retroviral vector into 6-12 week old BALB/c nude mice, only one subject of nine nude mice had a tumor weight of 2.67 g, but the control group all displayed tumors with a weight of 3.24 +/- 0.56 g. Preliminarily clinical trials also showed that the new version was obviously a promising combination.
Animals↗
Effects of somatostatin, octreotide and pitressin plus nitroglycerine on systemic and portal haemodynamics in the control of acute variceal bleeding.
To examine the haemodynamic effects of somatostatin (SS) and octreotide (OC) versus pitressin plus nitroglycerine (PN) in the control of variceal bleeding, 224 patients with acute oesophageal and gastric variceal haemorrhage were randomly divided into three groups and treated with SS, OC and PN; they also had their Doppler ultrasound parameters measured before, during and after treatment. The success rates of bleeding control in the SS (80.9%, 86.8% and 89.7%, p<0.001) and OC (75.3%, 80.8% and 84.9%, p<0.01) groups were significantly higher than in the PN group (51.8%, 59.0% and 65.1%) at 24, 48 and 72 hours respectively, and the average duration of SS (12.7 + 6.8 h) and OC (13.8 + 8.0 h) was significantly lower than that of PN (24.6 + 15.4 h, p<0.001). Side-effects of SS (7.4%) and OC (8.2%) were less than those of PN (41.0%, p<0.001 and p<0.01). The diameter of portal vein (PVD), velocity of portal vein (PVV), volume of portal blood flow (PVF) and hepatic artery pulsatility index (HA-PI) in all three groups decreased significantly during initial treatment, but recovered when treatment was stopped. Heart rate and cardiac output decreased significantly in patients treated with SS and OC; mean arterial pressure was unchanged. However, heart rate and mean arterial pressure increased, and cardiac output decreased, with PN. Somatostatin and octreotide were more effective than pitressin plus nitroglycerine in patients with acute variceal haemorrhage, with fewer side-effects, and may decrease PVF and portal vein pressure through reduction of cardiac output and dilatation of the visceral blood vessels.
Acute Disease↗