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J Dai

Publications and source records attributed to J Dai.

At least 163 records · Page 9Linked to original sources
PubMed1997

[Imaging findings of malignant fibrous histiocytoma in the lung].

OBJECTIVE: To show the characteristic findings of the image of primary malignant fibrous histiocytoma (PMFH) in the lung. METHODS: Fifty-one cases of pulmonary PMFH were reviewed, 7 from our hospital and 44 from the literature including chest radiograms 51 cases; CT scans 9 cases and MRI 1 case. RESULTS: Primary MFH comprises 0.01% of all pulmonany malignant tumors seen in the same period. The mean age was 55 years. The most common complaints were cough, hemoptysis and chest pain. In 40 cases who were followed, recurrence/metastasis developed in 42.9% with 80% appearing within one year. The sites of the lesion were: right lobe in 34 cases and left lobe in 17 cases. It was peripheral in 49 (96.1%) cases and central in 2 (3.9%). The finding of the image was a large solitary mass (> 5 cm, 68.6%) with regular or irregular margin. Most of the tumors were well circumscribed (56.9%) or lobulated (43.1%) showing homogeneous attenuation (64.7%). Cystic changes or cavitation was observed in a few cases. On CT, the lesion shows low attenuation and involves the adjacent structures. CONCLUSION: PMFH gives images which are not pathognomonic. Yet, its regular, well defined border, less lobulated configuration could differentiate itself from the common malignant and benign lesionsin the lung. CT and MRI can provide useful information in demonstrating the nature and extent of invasion of the tumor.

Aged↗
PubMed1997

[Antitumor activity of the clavam peptide antibiotic G0069A].

Antibiotic G0069A, produced by a Streptomyces strain isolated from a soil sample collected in Yunnan Province, China, has been verified as a clavam peptide. Determined by MTT assay, G0069A showed highly potent cytotoxicity to cancer cells with multidrug resistance. The IC50 values of G0069A to KB and KB/VCR cells were 0.60 and 0.46 mumol.L-1, and to MCF-7 and MCF-7/ADM cells were 1.4 and 1.2 mumol.L-1, respectively. G0069A displayed equally potent cytotoxicity to the parent cell lines and their resistant sublines. When administered by i.v. or i.p. route at tolerable doses, G0069A exhibited markedly inhibitory effect on the growth of sarcoma 180 and hepatoma 22 in mice. At dose level of 3 mg.kg-1, i.v., x3, sarcoma 180 and hepatoma 22 were suppressed by 87%(P < 0.01) and 72%(P < 0.01), respectively. The results indicate that G0069A is a beta-lactam antibiotic showing antitumor activity.

Animals↗
PubMed1997

[Analysis of triacylglycerol composition of perilla oil by combination of non-aqueous reversed-phase high performance liquid chromatography with gas chromatography].

Perilla oil was verified to be a rich source of polyunsaturated fatty acid (PUFA). Its linolenic content is 64.82%, the highest in the plants. Its triacylglycerol (TAG) components were isolated and identified first time in this paper by a combination of non-aqueous reversed-phase high performance liquid chromatography (RP-HPLC) with gas chromatography (GC). The TAG of perilla oil were isolated by HPLC with a Zorbax ODS column (5 microm, 4.6 mm i.d. x 250 mm; Dupont, Inc) and differential refractometer. The eluent was acetone/acetonitrile (80:20, V/V) with flow rate of 1.0 mL/min. The TAG component acyl groups were converted to fatty acid methyl esters (FAME). The acyl constituents for each TAG were determined by GC analysis. Gas chromatography of FAMEs was performed with a AC20 Carbowax 20M column (30 m x 0.32 mm i.d.). Detector and injection port temperatures were 260 degrees C. Column temperature was programmed from 120 degrees C, 1 min initially hold, then 8 degrees C/min to 220 degrees C and finally hold for 10 min. Nitrogen was the carrier gas. FAMEs peaks were identified by comparison of their retention times with those of standards. The retention times of the palmitic, stearic, oleic, linoleic, n-nonadecanoic acid (internal standard) and linolenic FAMEs were 10.7, 13.0, 13.3, 13.8, 14.2 and 14.7 min respectively. Five main components were determined. They were LnLnLn (34.10%), LnLnL (13.22%), LnLL (6.22%), LnLnO (11.38%) and LnLnP (9.17%). The TAG contents were corrected from their fatty acids content. The combination of non-aqueous RP-HPLC with GC is a simple and rapid method for the analysis of oil TAG structure and is also very helpful for the identification of oil quality.

Chromatography, Gas↗
PubMed1997

Alcohol feeding impedes early atherosclerosis in low-density lipoprotein receptor knockout mice: factors in addition to high-density lipoprotein-apolipoprotein A1 are involved.

The effect of alcohol feeding on the development of atherosclerosis was investigated in low-density lipoprotein receptor gene-knockout (LDLR-/-) mice. Eight-week-old male mice were pair-fed atherogenic liquid diets containing ethanol at different levels (w/v; group A, 5%; group B, 2.5%; and group C, 0%). Tissue sections of the heart were stained with Oil Red O to examine for fatty lesions in proximal aorta. Results showed that the lesion size of group A was 70% smaller than group C after 6 weeks. By contrast, the lesion size of group B was not significantly different from that of group C. Serum high-density lipoprotein-apolipoprotein A1 (apo A1) A1 in LDLR-/- mice was suppressed by feeding the atherogenic diet, but the decrease was negated by alcohol (both groups A and B). The effectiveness of 5% alcohol to protect against atherosclerosis waned with time, but was still noticeable at 12 weeks, even though serum apo A1 remained high. Serum apolipoprotein E was increased by the high fat diet, but not altered by alcohol in the diet. Our data, therefore, show that: (1) alcohol-feeding impedes early atherosclerosis in LDLR-/- mice (this effect of alcohol is dose-dependent); (2) the protective effect of alcohol is not entirely attributable to an elevated serum high-density lipoprotein-apo A1; and (3) severe impairment of lipoprotein metabolism due to a lack of low-density lipoprotein receptors can eventually overwhelm the protective effect of alcohol against atherosclerosis.

Alcohol Drinking↗
PubMed1997

Cell-cycle dependent anti-FGF-2 staining of chicken cardiac myocytes: movement from chromosomal to cleavage furrow- and midbody-associated sites.

Fibroblast growth factor-2 (FGF-2) promotes cardiac myocyte proliferation and has been detected in extracellular as well as cytoplasmic and nuclear compartments. As a first step in examining the participation of intracellular FGF-2 in cardiac myocyte cell cycle we have investigated its localization in proliferative chicken cells during interphase and the various stages of mitosis in culture. We have used a previously characterized and affinity-purified anti-FGF-2 antibody preparation which recognizes the 19-22 kDa variants of chick FGF-2. By immunofluorescence, bright, punctate anti-FGF-2 labelling was observed in 26% of interphase nuclei from myocytes derived from 5 day embryonic heart ventricles; these nuclei were positive for anti-bromodeoxyuridine staining indicating that they are at the S- or G2 phase of the cell cycle. In prophase and metaphase, bright anti-FGF-2 staining was detected in apparent association with chromosomes. During anaphase, however, anti-FGF-2 staining dissociated from chromosomal locations distinctly remaining in strand-like structures in the area of ensuing cleavage furrow formation. In late telophase and cytokinesis, strong staining persisted in the area of the midbody and reappeared in a small fraction of newly formed daughter nuclei. Absorption of the antibody preparation with immobilized FGF-2 eliminated all staining. This dynamic pattern of anti-FGF-2 staining suggests that chick FGF-2 or immunologically related protein(s) not only increase in DNA-synthesizing nuclei but they may play a role in subsequent stages of mitosis and cytokinesis.

Animals↗
PubMed1996

R(+)-8-OH-DPAT, a 5-HT1A receptor agonist, inhibits amphetamine-induced serotonin and dopamine release in rat medial prefrontal cortex.

Pretreatment with R(+)-8-OH-DPAT, a selective serotonin (5-HT)1A receptor agonist (50 micrograms/kg, s.c.), inhibited D-amphetamine sulfate (1.0 mg/kg, s.c.)-induced increases in extracellular levels of both 5-HT and dopamine (DA) in rat medial prefrontal cortex, as determined by in vivo microdialysis. The inhibitory effect of R(+)-8-OH-DPAT was completely reversed by the selective 5-HT1A receptor antagonist WAY 100,635 (100 micrograms/kg s.c.) administered 5 min prior to R(+)-8-OH-DPAT. These results suggest that stimulation of 5-HT1A receptors may inhibit amphetamine-induced release of 5-HT and DA in the medial prefrontal cortex.

8-Hydroxy-2-(di-n-propylamino)tetralin↗
PubMed1996

Evaluation of Bacillus thuringiensis and Bacillus sphaericus Strains from Chinese Soils Toxic to Mosquito Larvae

During our research to isolate and screen microbial agents, eight Bacillus thuringiensis isolates and five Bacillus sphaericus isolates were shown to have high toxicity to mosquito larvae. Comparing the LC50 values, four B. sphaericus isolates with LC50 values ranging from 0.50 to 1.47 ng/ml were about two to six times more toxic than strain 1593 (LC50 3.00 ng/ml) against larvae of Culex quinquefasciatus. Four B. thuringiensis isolates (LC50 values ranging from 3.80 to 7.54 ng/ml) and four B. sphaericus isolates with LC50 of 17.0 to 43.7 ng/ml were more toxic to Aedes aegypti than strain 1897 (LC50 8.46 ng/ml) and strain 1593 (LC50 67.3 ng/ml). As to Anopheles hyrcanus, the LC50 values of three B. sphaericus isolates ranging from 3.63 to 5.73 ng/ml were three to five times smaller than that of strain 1593 (LC50 16.1 ng/ml). Two B. sphaericus isolates showed high toxicity against mosquito larvae in the three genera Culex, Aedes, and Anopheles.

Journal Article↗
PubMed1996

Comparison of three immunoassay kits for serum thyroglobulin in patients with thyroid cancer.

OBJECTIVES: This study describes the evaluation of performance of three immunoassay kits [Sanofi-Pasteur, IRMA, with five monoclonal antibodies; Wallac-Delfia, FIA, with double monoclonal antibodies; and Diagnostic Products Corporation (DPC), RIA, with polyclonal antibodies] for serum thyroglobulin in patients with thyroid cancer. Specific aims were (a) to recognize a method with minimal interference, by comparing analyte recoveries, from thyroglobulin autoantibodies (TgAb) that can be present in some thyroid cancer patient samples, (b) to correlate individual results with those from Mayo Medical Laboratories (MML) (current referred out assay service used by our institute), and (c) to compare assay precision. METHODS: In evaluating performance of the three immunoassays, procedures were followed as recommended by the respective manufacturers. Parallel comparison of the three immunoassays with the MML procedure was performed with thyroid cancer patient sera. Recovery studies utilized sera from 15 thyroid cancer patients, 4 Hashimoto's thyroiditis patients, and 1 Grave's disease patient. TgAb were also measured directly by an IRMA thyroglobulin antibody kit (Sanofi-Pasteur). RESULTS: Among the randomly selected 20 samples assayed in parallel studies, low recoveries (< 80%) were present in 2 samples by IRMA assay (Sanofi-Pasteur), 8 samples by FIA assay (Wallac-Delfia), and 10 samples by RIA assay (DPC). The majority of the low recovery samples contained high titers of TgAb. All three kits correlated well with the Mayo method. At the control-1 level (approximately 9.9 microgram/L by Delfia determination), both the IRMA kit (CV = 1.96%, n = 10) and FIA Kit (CV = 2.16%, n = 10) showed good within-run precision. CONCLUSIONS: In our hands, the IRMA Kit (Sanofi-Pasteur) demonstrated excellent precision, analyte recoveries, the least interference from TgAb, and good correlation with the Mayo Medical Laboratories procedure.

Autoantibodies↗
PubMed1996

Modulation of membrane dynamics and cell motility by membrane tension.

The plasma membrane of most cells is drawn tightly over the cytoskeleton of the cell, resulting in a significant tension being developed in the membrane. The tension in the membrane can be calculated from the force required to separate it from the cytoskeleton; and the force itself can be measured rapidly by using laser tweezers. Recent observations indicate that decreasing membrane tension stimulates endocytosis and increasing tension stimulates secretion. Thus, membrane tension provides a simple physical mechanism to control the area of the plasma membrane. Here, we speculate that tension is a global parameter that the cell uses to control physically plasma membrane dynamics, cell shape and cell motility.

Journal Article↗
PubMed1996

Deformation and flow of membrane into tethers extracted from neuronal growth cones.

Membrane tethers are extracted at constant velocity from neuronal growth cones using a force generated by a laser tweezers trap. A thermodynamic analysis shows that as the tether is extended, energy is stored in the tether as bending and adhesion energies and in the cell body as "nonlocal" bending. It is postulated that energy is dissipated by three viscous mechanisms including membrane flow, slip between the two monolayers that form the bilayer, and slip between membrane and cytoskeleton. The analysis predicts and the experiments show a linear relation between tether force and tether velocity. Calculations based on the analytical results and the experimental measurements of a tether radius of approximately 0.2 micron and a tether force at zero velocity of approximately 8 pN give a bending modulus for the tether of 2.7 x 10(-19) N.m and an extraordinarily small "apparent surface tension" in the growth cone of 0.003 mN/m, where the apparent surface tension is the sum of the far-field, in-plane tension and the energy of adhesion. Treatments with cytochalasin B and D, ethanol, and nocodazole affect the apparent surface tension but not bending. ATP depletion affects neither, whereas large concentrations of DMSO affect both. Under conditions of flow, data are presented to show that the dominant viscous mechanism comes from the slip that occurs when the membrane flows over the cytoskeleton. ATP depletion and the treatment with DMSO cause a dramatic drop in the effective viscosity. If it is postulated that the slip between membrane and cytoskeleton occurs in a film of water, then this water film has a mean thickness of only approximately 10 A.

Animals↗
PubMed1996

Clinical impact of transcutaneous bilirubinometry as an adjunctive screen for hyperbilirubinemia.

OBJECTIVE: To determine what the clinical impact would be of implementing a jaundice meter for use in a busy neonatal service as an adjunctive screening tool for hyperbilirubinemia. DESIGN AND METHODS: Test utilization data was collected for a 6-month period to determine how neonatal bilirubin was utilized in this hospital. The jaundice meter was evaluated in a study population of healthy term infants. The performance characteristics of the meter and the test utilization data were used to predict the clinical impact a meter could have on screening for hyperbilirubinemia. RESULTS: Utilization data indicated that about 60% of all single bilirubin neonatal testing (i.e., bilirubin only ordered) was done by normal nurseries. A jaundice meter cutoff decision reading of 17 was shown to have a sensitivity of 100% and a specificity of 68% for hyperbilirubinemia (> 260 mumol/L) in a study population of healthy term infants. From this data, it was estimated that use of a jaundice meter could eliminate 43% of the single (i.e., not combined with other tests) bilirubin tests done on healthy term neonates with no prior exposure to phototherapy. This constitutes an overall 20% reduction in bilirubin testing in normal nurseries when testing done on babies exposed to phototherapy and combined bilirubin testing are taken into consideration. Additionally, it was shown that there would be an improvement of 9% in the prediction of hyperbilirubinemia without loss of 100% sensitivity. CONCLUSION: Use of a jaundice meter in normal nurseries as an adjunctive screening tool enhances patient care by reducing the overall blood procurement rate in normal nurseries by 20% and increasing screening efficiency for significant hyperbilirubinemia by 5%.

Bilirubin↗
PubMed1996

Coronary vascular and endothelial reactivity changes in transgenic mice overexpressing atrial natriuretic factor.

Recent advances in genetic methods permit the introduction of random and defined mutations into the mouse germ line, producing novel mouse strains, some of which affect the heart and vasculature. A TTR-ANF transgenic strain of mice, which constitutively expresses a fusion gene consisting of the transthyretin promoter and the ANF structural gene, has been shown to result in a lifelong elevation of plasma atrial natriuretic factor (ANF) and a chronically lowered arterial blood pressure. However, no established method for efficient functional analysis of possible alterations in coronary vascular function in mice has been reported. In the present study, we describe an isolated mouse coronary artery preparation that permits an effective and reproducible evaluation of coronary endothelial and vascular function. Both left main and right coronary arteries (resting luminal diam 70-90 microns) were isolated and pressurized, and changes in luminal diameter were determined by videomicroscopy. The coronary pressure-luminal diameter relationship was not significantly different between TTR-ANF transgenic and nontransgenic littermates. Relaxation of coronaries to 0.1-100 nM ANF was significantly reduced in transgenic [maximum effect (Emax) = 43 +/- 10% (mean +/- SE) of 11 vessels] compared with nontransgenic (Emax = 73 +/- 7%, n = 15) mice. Similarly, the relaxant response to an endothelium-dependent dilator, acetylcholine, but not to endothelium-independent dilators sodium nitroprusside and isoproterenol, was significantly decreased in transgenic (Emax = 46 +/- 10%, n = 12) compared with nontransgenic (Emax = 85 +/- 5%, n = 14) mice. In contrast, the dose-dependent vasoconstriction to endothelin-1, KCl and the thromboxane mimetic U-46619 was not significantly different between the two groups. These results indicate that lifelong ANF elevation in mice is associated with a decreased responsiveness of coronary vasorelaxation to ANF, possibly resulting from receptor downregulation and/or desensitization. Endothelium-dependent relaxation was also significantly depressed in transgenic mouse coronary arteries, but smooth muscle-specific dilation and constriction were not affected. The present findings are consistent with previous studies of TTR-ANF transgenic mice showing that ANF regulates arterial blood pressure and vascular function.

15-Hydroxy-11 alpha,9 alpha-(epoxymethano)prosta-5↗
PubMed1996

Studies on the transfer techniques of three maize genes.

Maize transformation has been carried out through microprojectile bombardment, ultrasonication in a DNA buffer, and ovary-injection with a self-made microinjector. The plasmid pB48.415, which carries a 3'-truncated Bt-toxin protein gene and a hygromycin phosphotransferase (hpt) gene, was used in the transformation. Transgenic maize plants were obtained from immature embryos and embryogenic calli bombarded with a particle gun, embryogenic calli ultrasonicated under different conditions of ovaries injected 10-20 hours after pollination. The results of Dot blotting and Southern blotting analyses proved the integration of the Bt gene into maize genome.

Bacillus thuringiensis Toxins↗
PubMed1996

[Computed tomographic features of malignant fibrous histiocytoma].

CT findings in 45 cases of malignant fibrous histiocytoma (MFH) were reviewed. There were 27 primary and 22 (23 episodes) cases of recurrent tumor, 4 (5 episodes) cases of recurrent tumor were initially treated in our hospital. Tumors located in craniofacial area in 16 cases, abdomen or retroperitoneum in 17, soft tissues of extremities or trunk in 12. There were 26 male and 19 female patients, with 19-82 years of age (medium, 46 years of age). The most common clinical symptom was a local mass (64.4%). On CT scan, 84% (42/50) of lesions with tumor mass > 5 cm, mostly with irregular contour, medium to markedly hyper-attenuated enhancement were revealed in 78.8% of cases and 60.6% of cases with hypo-attenuated necrotic area inside. Most of the tumors invaded adjacent organs or structures which were revealed in 75.8% of cases, such as infratemporal fossa, pterygopalatine fossa, extradural space in the craniofacial lesions; liver, psoas muscle, abdominal wall in abdominal and retroperitoneal lesions. Expansible change could be shown when paranasal sinus was invaded (8/9). The CT findings of recurrent lesions were similar to the primary ones. Enhanced CT scan may provide useful information in demonstrating the nature and extent of invasion of the tumor. Closely integrating CT and pathologic findings is important for the differential diagnosis of malignant tumors of soft tissue.

Adult↗
PubMed1996

[The regulation of the secretion of transforming growth factor-beta 1 by estrogen on ovarian cancer AO, 3AO cell lines and its relationship with cell proliferation].

OBJECTIVE: To investigate the regulatory effect of the secretion of transforming growth factor-beta 1 (TGF-beta 1) by estrogen on ovarian cancer AO, 3AO cell lines and on cell proliferation. METHOD: The secretion of TGF-beta 1 was investigated by using western dot blot and the cell proliferation by 3H-thymidine uptake. RESULT: In vitro, AO cells under the effect of estrogen can secreted TGF-beta 1, and there was cell proliferation, but both gave dose-dependent responses. Estrogen significantly promoted the secretion of TGF-beta 1 of AO cells at low (10(-13) mol/L) and high (10(-5)mol/L) concentrations, but the level of cell proliferation showed inhibition. In contrast, in the 3AO cells under the same conditions, no difference in TGF-beta 1 secretion was found from those of the control groups, dose-dependent response was seen in cell proliferation and there was no significant correlation between the expression of TGF-beta 1 and cellular proliferation. CONCLUSION: The results suggest that there may be TGF-beta 1 autocrine loop in AO ovarian cancer cell line, which, when estrogen regulated may be associated with the cell proliferation. In 3AO cell line, under the same conditions, TGF-beta 1, autocrine is not regulated by estrogen, nor is it related to cell proliferation regulation.

Cell Division↗
PubMed1996

[Quantitative analysis of organochlorine pesticide residues in Chinese drugs].

This paper reports the GC determination of 20 organochlorine pesticides in Chinese drugs Flos Ionicerae and Moluodan etc by the present method of Japan for determinaing pesticide residues. The results suggest that except Folium Isatidis, Radix Codonopsis and Sanqi Pian all accord with the for provisions pesticide residues in Japanese foodstuffs.

Chromatography, Gas↗