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At least 1,027 records · Page 57Linked to original sources

PubMed2006

[Effect of HepG2 cells modified with CD80-IgG1 Fc fusion protein on anti-tumor immune response by lymphocytes].

AIM: To investigate the anti-tumor immune response of lymphocytes elicited by HepG2 cells modified with CD80-IgG1 Fc fragment fusion protein (CD80-Fc). METHODS: HepG2 cells were modified with CD80-Fc, then the expression of CD80 on the cell surface was analyzed by flow cytometry (FCM). After mixed lymphocyte-tumour cell reaction (MLTR) of the modified HepG2 cells and peripheral lymphocytes of healthy volunteers, the proliferation and cytotoxicity of the lymphocytes were tested by MTT colorimetry and LDH release assay,respectively. RESULTS: CD80-Fc could be efficiently bound on HepG2 cells. HepG2 cells modified with CD80-Fc fusion protein dramatically elicited proliferation and cytotoxicity of normal lymphocytes. CONCLUSION: CD80 may play an important role in anti-tumour immune response. HepG2 cells modified with CD80-Fc fusion protein can elicited potent anti-tumor immune response. This fusion protein provides a convenient means for further potential use in immunotherapy of tumor.

Animals↗

PubMed2006

[Ouabain-induced apoptosis of Jurkat cells correlates with activation of caspase-3 and regulation of Bcl-2 gene family].

The study was aimed to explore the apoptosis effect of ouabain on Jurkat cells and its mechanism. MTT method was used to observe the inhibitory effect of ouabain on Jurkat cell proliferation. Apoptosis was detected by using flow cytometry (FCM) and the terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick end-labeling reaction method (TUNEL). The protein expressions of Bax, Bcl-2 and active subunits of caspase-3 were measured by Western blot. Activities of caspase-3 were determined by colorimetry method. The results showed that ouabain could induce apoptosis of Jurkat cells, the expression of Bax protein in process of cell apoptosis, caspase-3 activity of Jurkat cells were remarkably enhanced after ouabain treatment. It is concluded that ouabain may induce apoptosis of Jurkat cells due to the activation of caspase-3 resulting from regulation of Bax protein and Bcl-2 gene expressions.

Apoptosis↗

PubMed2006

[In vitro cultivation of dendritic cells with serum-free medium].

This study was aimed to investigate the protocol in vitro to incubate the dendritic cell (DC) derived from peripheral blood monocytes using serum-free medium X-VIVO 20. Peripheral blood monocytes from healthy donors were treated with 100 ng/ml GM-CSF and 500 U/ml IL-4, respectively. After cultivation for 6 days, they were treated with 100 ng/ml calcium ionophore A23187. After cultivation for 24 hours the cellular morphology was observed under invert microscope, the surface markers were analyzed by flow cytometry, the proliferation of allogenetic T cells was detected by MTT colorimetry, the specific cytotoxicity of T cells primed with DC was examined by MTT assay. The results showed that in all three groups with serum-free, fetal calf serum (FCS) and human AB serum mediums, cells displayed characteristic morphological features of DC. Simultaneously CD14 expression was decreased, and CD83, HLA-DR and CDw123 expression were increased on these cells. In addition, DCs cultured with these methods could evidently stimulate the proliferation of allogenetic T cell. As compared with the two controls of serum containing groups, the cultured cells in the serum-free groups showed almost the same allo-stimulatory capability and cellular morphology and surface markers, and T lymphocytes primed with the culture-derived DC exhibited the similar killing activity to K562 (P > 0.05). It is concluded that there is no significance in DC numbers, morphology, epitope and ability to stimulate the proliferation of allogenetic T cells between DC induced by serum-free X-VIVO 20 medium and DC induced by serum-contained medium. DC cultured and induced by serum-free medium is worth using in practice widely.

Cell Culture Techniques↗

PubMed2006

[Establishment of model with inner ear mimetic aging and mtDNA 4834 bp deletion in rats].

OBJECTIVE: To explore the establishment of the mimetic aging effect in the inner ear of the rat. METHOD: Twenty-four Wistar rats were randomly divided into two groups: group A (D-galactose group, n = 14), which were treated with hypodermic 5% D-galactose (150 mg x kg(-1) x d(-1)) for 8 weeks and then with intraperitoneal saline for 10 days, and group B (control group, n = 10), which were given saline only. Auditory brainstem response(ABR) was used to detect the hearing threshold of rats, and colorimetry was used to analyze the activity of the glutathione peroxidase (GSH-PX). The inner ear tissue was harvested and mitochondrial DNA was amplified to identify the 4 834 bp deletion mutation by nested primer polymerase chain reaction (nested PCR) technique. RESULT: The incidence of mitochondrial DNA 4 834 bp deletion of group A was 100% (28/28), while the deletion of group B was 0. The activity of the GSH-PX in group A (59.07 +/- 8.70 U) was lower than that in group B (142.10 +/- 7.02 U). The difference between group A and group B was significant (t-test, P < 0.01). Variation in ABR threshold of (5.36 +/- 3.08) dB peSPL was observed in group A, and (6.50 +/- 3.37) dB peSPL in group B. The difference in shift of ABR threshold between group A and group B was not significant (P > 0.05). CONCLUSION: The mimetic aging effect in the inner ear of the rat can be induced by D-galactose, and this rat model presents high incidence of mtDNA4834 deletion. But no hearing loss was found in this model.

Aging, Premature↗

PubMed2007

[Effect of siRNA transfection targeting VEGF gene on proliferation and apoptosis of human breast cancer cells].

AIM: To explore the effect of RNA interference-mediated vascular endothelial growth factor (VEGF) gene silencing on proliferation and apoptosis of human breast cancer MCF-7 cells. METHODS: Small interfering RNA (siRNA) targeting VEGF gene was designed and DNA template was synthesized, then siRNA was obtained by in vitro transcription. After ds-siRNA was transfected into MCF-7 cells with Lipofectamine, the proliferation of MCF-7 cells was detected by MTT colorimetry, and the apoptosis was measured by Hoechst33258 staining. The change of cell cycle was analyzed by flow cytometry (FCM). The expression of VEGF on mRNA and protein level was analyzed by RT-PCR and immunohistochemical technology respectively. RESULTS: The siRNA targeting human VEGF gene effectively inhibited the proliferation of MCF-7 cells, induced cell apoptosis, arrested the cell cycle in G(0)/G(1) phase, and decreased the expression of VEGF on both mRNA and protein level. But these effects did not appear in scrambled siRNA (siRNA(SCR)) control group. CONCLUSION: The siRNA targeting human VEGF gene could reduce VEGF expression, inhibit cellular proliferation and induce apoptosis in MCF-7 cells in vitro.

Apoptosis↗

PubMed2006

[Effects of basic fibroblast growth factor gene transfection on biochemistry of meniscal fibrochondrocytes].

OBJECTIVE: To explore the effects of the basic fibroblast growth factor(bFGF) gene transfection on the meniscal fibrochondrocytes with the reconstructed lentivirus and to observe the response of the meniscal fibrochondrocytes to the bFGF gene transfection. METHODS: The cultured meniscal fibrochondrocytes were isolated from the same 3-month-old New Zealand rabbit. The cultured first-generation meniscal fibrochondrocytes were divided into 3 groups:Group A (experimental group), Group B (control group), and Group C (blank group). Each group comprised the cells in a 24-hole flask in which each hole contained 2 x 10(4) cells. At the confluence of 60%, the fibrochondrocytes in Group A were cultured with the reconstructed lentivirus carrying the bFGF gene. The fibrochondrocytes in Group B were cultured with the lentivirus carrying no bFGF gene. The fibrochondrocytes in Group C were cultured without any intervention. After 48 h, the cell cycle, the collagen synthesis ability, the expression of bFGF, and the cell proliferation ability in each group were investigated. RESULTS: In Group A, the bFGF expression of 870+/-60 pg/ml was detected in the cells 48 h after the co-culture; however, in Group B and Group C, no expression of bFGF was found. After the co-culture for 6 days, the results of the MTT colorimetry revealed that the cells in Group A had an absorptance of 0.427 +/-0.037, which had a significant difference when compared with that in Group B and Group C (0.320+/-0.042, 0.308 +/-0. 034,P<0. 01). The cell cycle was significantly shorter in Group A than in Group B and Group C (P<0. 05); The durations of G, S and G2M of the cells in Group A were 16.28, 12.60 and 11.04 h, but those in Group B and Group C were 23.61, 16.90, 21.33 h and 21.56, 19.80, 21.41 h, respectively. The disintegration per minute of the cells was significantly greater in Group A than in Group B and Group C (7 281.69+/-805.50 vs 5 916. 40+/-698. 11 and 5 883. 57 +/-922.63.P<0. 05). CONCLUSION: The lentivirus vector can transfer the bFGF gene into the meniscal fibrochondrocytes, resulting in an increase of the cell proliferation and the collagen synthesis.

Animals↗

PubMed1991

[Studies on the relationship between acupuncture analgesia and testosterone or dihydrotestosterone in blood plasma].

UNLABELLED: 55 rats (Wistar, Male, 250-350 g) were divided into 4 groups: (1) BTA (bilateral testectomy + adrenalectomy) group, (2) BT (bilateral testectomy) group, (3) BA (bilateral adrenalectomy) group, (4) SO (sham operation) group. EA was applied to bilateral "Tsusanli" points of each animal at 72 h. after operation. The potassium iontophoretic colorimetry was used to determine the pain threshold of rats, radioimmunoassay was used to measure the contents of T and DHT in femoral vein blood. T, DHT and the pain threshold of each animal were measured before operation, at 72 h, after operation and after EA, but for the SO group the measurement was done once at 72 h. after im testosterone phenylacetate. RESULTS: The content of T in BTA and BT groups were decreased. significantly at 72 h. after operation, but the changes of the pain threshold were similar to BA and SO groups. After EA the content of T in BT and SO groups were raised significantly (P less than 0.01), but in BT group raised slightly (P greater than 0.05). It was found in all animals that the content of DHT and the pain threshold were significantly elevated at 45 min after EA. No effect upon the pain threshold and EA analgesia was observed in SO group after im testosterone phenylacetate. CONCLUSION: T (from testes and adrenal) and DHT rose markedly after EA. Increasing T and DHT or decreasing T in plasma had no effect upon the pain threshold and EA analgesia. It is suggested that T and DHT in plasma may not play a role in the EA analgesia, in the other hand, EA may be used for improving the hypogonadal condition.

Acupuncture Analgesia↗

PubMed1991

The effects of ivermectin on the viability of Onchocerca lienalis microfilariae in vitro and on their subsequent development in the blackfly vector, Simulium ornatum.

Experiments examined the sensitivity of Onchocerca lienalis microfilariae (mf) to ivermectin in vitro using a range of parameters to measure viability. Incubation in drug (1 x 10(-4) and 5.71 x 10(-8) M) caused an immediate decrease in motility levels in a concentration dependent fashion with a continuing decline over 24 h; the inclusion of a monkey kidney cell (LLCMK2) feeder layer in the culture system partially abrogated drug effects. The use of feeder cells allowed the longer-term culture of mf; incubation in drug at low concentrations (5.71 x 10(-8) and 1 x 10(-10) M) significantly reduced motility levels during a 17 day trial. Using MTT colorimetry it was found that 10,000 untreated mf per replicate sample were required to produce a sufficient quantity of formazan to make comparisons, and that formazan formation was most rapid during the first 30 min of incubation in MTT but continued up to 3-4 h. Following incubation of mf in ivermectin (1 x 10(-4) and 5.71 x 10(-8) M) for 24 h, only the higher concentration inhibited formazan formation (51%), while motility levels were reduced by 94% and 45% respectively. Using the same drug concentrations, mf viability was assessed by measuring the uptake of [3H]2-deoxy-D-glucose; uptake was only significantly reduced (40%) by the higher concentration, while motility levels were reduced by 77% and 63% respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed1990

Studies on the distribution of mineral elements in the tooth of zinc-deficient rats.

Elemental analysis of plaque-like black deposits noted on the surface of teeth in zinc-deficient rats at necropsy was performed. Rats deficient in zinc show signs of abnormality in iron metabolism and increase or accumulation of iron in plasma and tissues. This study was designed, therefore, to examine the plasma and salivary levels of iron and other elements and to determine the distribution of mineral elements in the dental substances of zinc-deficient rats by contact microradiography, electron probe microanalysis (EPMA) and X-ray fluorescent element mapping spectrometry (XEMS) on ground sections of teeth. Rat tooth specimens were analyzed also for zinc, iron, copper and manganese using colorimetry and Inductively Coupled Plasma, ICP. EPMA and XEMS analyses revealed the presence of iron on the enamel surface of maxillary molars teeth of zinc-deficient rats. However, no such deposition was seen on those of controls. The zinc-deficient rats showed higher iron concentration in mixed saliva and in plasma, compared with the controls. Thus, the sign of abnormality in iron metabolism noted in the oral cavity of zinc-deficient rats was investigated by EPMA and XEMS analyses, with discussion on the origin of supradental iron deposits.

Animals↗

PubMedDate not supplied

Development of a parenteral formulation of trimelamol, a synthetic S-triazine carbinolamine-containing cytotoxic agent.

Trimelamol is a synthetic s-triazine carbinolamine-containing agent exhibiting poor aqueous solubility and stability characteristics. The present studies were conducted to provide a stable parenteral dosage form of trimelamol, which could be used for clinical evaluation of the drug and also be manufactured on a commercial scale without undue drug decomposition occurring. Solubility and stability of trimelamol were found to increase in the presence of aqueous-polyethylene glycol (PEG) solutions of increasing average PEG molecular weight (up to mol wt = 1000); PEG 1000 (75%) in water provided the optimum formulation vehicle. In contrast to the optimum liquid formulation of the drug (detailed above) it was necessary to make various compromises to the formulation in terms of drug solubility and stability, because of the problems encountered in processing (e.g., sterile filtration, lyophilization, and reconstitution). Freeze-drying of the formulation extended the product shelf-life relative to the liquid formulation. Differential Scanning Colorimetry (DSC) studies, to determine the freeze-drying cycle parameters, showed that the freezing and melting characteristics of the trimelamol-PEG formulations were dependent upon the rate of cooling, as well as the concentration and average molecular weight of PEG used. The prototype containing 30 mg/mL trimelamol in a 50% PEG 3400-aqueous vehicle was found to be the optimal formulation for sterile filtration, lyophilization, and subsequent reconstitution. Through the use of in vitro techniques, the possibility of hemolysis occurring upon injection resulting from the inclusion of high molecular weight PEGs in the vehicle, was shown to be unlikely.

Animals↗

PubMed1979

[Experimental silicosis. I. Fibrogenic activity of quartz material used in the ceramic industry].

A high concentration of silica dust in the air many workstands in ceramic plants is a serious risk for the health of exposed workers. It can cause the development of silicosis. The aim of this paper is to evaluate a fibrogenic activity of dusts containing 98% crystalline silica. The ceramic masses have about 25% of Quartz. The samples of 2 lode quartz and 4 sand quartz originated from different mines in Poland were used for the experiment. Their physical properties were analysed by X-ray diffraction and SiO2 content was determined by colorimetry. Their biological aggresiveness was characterised by wet weight, hydroxyproline content, lipid level in the lungs and wet weight of mediastinal lymph nodes of rats which were intratracheally given of the dusts. The results show that the tested dusts have a moderated fibrogenic activity. At short time (3 months) after their administration the fibrogenic changes in lungs were different depending on the kind of dusts, but at the 6th month of the experiment they did not differ at all. The exposition of workers to silica dusts is a great occupational hazard.

Air Pollutants↗

PubMed1989

Fluorescence polarization immunoassay of urinary 5-hydroxy-3-indoleacetic acid.

Fluorescence polarization immunoassay of 5-hydroxy-3-indoleacetic acid in urine is described and compared with liquid chromatography (electrochemical detection) and colorimetry. Reports of in-house performance data and results of clinical trials are included to emphasize the usefulness of the assay for routine work.

Chromatography, High Pressure Liquid↗

PubMed1989

[The quantitative determination of cyanide by FTD-GC].

In recent buildings, new materials containing chemical goods, chemical fibers and the like are in common use. Some of them evolve hydrogen cyanide (HCN) when burning. When a person meets a fire, therefore, it is necessary to measure his blood concentration of HCN as well as that of CO-Hb%. The blood concentration of HCN can be measured by colorimetry such as pyridine-pyrazolone method, gas-chromatography, electrode method, or the like. However, these methods require much time in pretreatment and the preparation of the reagent. We have investigated to find a new measurement method free from the above demerits, so that we have found the method by FTD-GC (Flame Thermionic Detecter Gas-chromatograph) is convenient and can be effected in a short time in comparison with the aforementioned method. GC-7AG made by Shimadzu Co. is employed as gas-chromatography and the headspace method is used in the quantitative determination. Samples are employed as solutions of potassium cyanide (KCN) either in distilled water or in fresh blood. The concentration of KCN is gradient in the range of 0.5-6 micrograms/ml. The quantitative conditions is investigated by a solution in distilled water as standard. Using this method, the concentration of HCN in the blood sample is determined slightly lower than that in the distilled water; however, this method is advantageous in convenience and the saving of time. Therefore, the method is useful in practice for the determination of the concentration of HCN.(ABSTRACT TRUNCATED AT 250 WORDS)

Chromatography, Gas↗

PubMed1989

[Spectrophotometric determination of boric acid by the curcumin method].

We have contrived an improved curcumin method for a spectrophotometric determination of the boric acid content, suitable for use on biologic materials to determine cases of poisoning. The use of this method enables detection of boric acid from a level of 10 micrograms/ml up to 5 mg/ml. The steps of this measurement method follow. Initially, boric acid was extracted by using a modification of Agazzi's method, i.e., to 1 ml of the sample solution, 0.2 ml of a 50% solution of sulfuric acid is added, along with 4 ml of 10 v/v% 2-ethyl-1,3-hexanediol/chloroform (an EHD solution). This mixture was then shaken for 5 min and then centrifuged for 10 min at 3,000 rpm. The extract of this chloroform phase was dehydrated with anhydrous sodium sulfate and used for the coloring reaction sample. The colorimetry procedure for determining the boric acid content follows. Fifty microliters of the extract solution was placed into a dry tube, to which 0.5 ml of a 0.3% curcumin/acetic acid solution and 50 microliters concentrated sulfuric acid were added, and the contents mixed thoroughly. The reaction mixture was then allowed to stand for 30 min at room temperature. (Rosocyanin is formed by the reaction of boric acid and protonated curcumin). Next, ethanol (3-138 ml) was added to the reaction mixture to decompose the excess protonated curcumin. Then, the absorbancy of the resulting solution was measured at 550 nm against a blank test solution. Ethanol was added to enable the measurement of the absorbancy (ethanol amounts tested were 3, 6, 12, 24, and 138 ml).(ABSTRACT TRUNCATED AT 250 WORDS)

Boric Acids↗

PubMedDate not supplied

Comparison of glazed and polished dental porcelain.

Many ceramists advocate polishing, rather than glazing, to control the surface luster of metal ceramic restorations. There is concern that compared to a natural glaze, the polished surface might have inferior properties. This study compared apparent fracture toughness (Kc) and stainability of a commercially available metal ceramic system with either a glazed or polished surface finish. The indentation technique was used for Kc determinations and colorimetry measurements of specimens immersed in a coffee solution for staining. Higher fracture toughness values were found for the polished specimens. No differences were detected in the staining characteristics.

Dental Polishing↗

PubMed1989

[Automated instruments for clinical laboratory--its past and future].

Since the invention of the Autoanalyzer (flow system) by Skeggs in 1953 and Swedish invention of the AGA-Autochemist (discrete system) remarkable developments have been made in the field of clinical laboratory examinations. The Autoanalyzer was improved, from mono-channel to multi-channel, using various methods besides colorimetry, and with the aid of computers, it is now being applied to hematology and immunochemistry as well as chemistry. Although the AGA-Autochemist was something like a chemical factory at the beginning, various instruments using discrete system have been produced according to the refinement of the basic mechanisms of AGA-Autochemist. It is now used in other fields and has contributed considerably to clinical laboratory examinations. This article reviews the development of these instruments at intervals of five years, as reported or reviewed at the scientific meetings of the Japan Society for Clinical Laboratory Automation, and articles of the Journal of the Society. The evaluation of merits and demerits of clinical automation is omitted due to limitation of space.

Autoanalysis↗

PubMedDate not supplied

Determination of nicarbazin in chicken tissues by liquid chromatography and confirmation of identity by thermospray liquid chromatography/mass spectrometry.

A liquid chromatographic method is described for the quantitative measurement of nicarbazin in chicken liver, fat, muscle, and skin tissues. The 4,4'-dinitrocarbanilide (DNC) portion of nicarbazin is extracted from tissues with ethyl acetate. After filtration and evaporation, the extract is purified by liquid-liquid partitioning with acetonitrile-hexane and alumina cartridge chromatography. DNC is separated and measured by reverse-phase liquid chromatography (RP-LC) with an octadecylsilyl (ODS) column and a UV detector set at 340 nm. The overall average recovery of DNC added to tissues was 83.4 +/- 3.1%. The lowest level validated in tissues by this procedure was 0.10 ppm. The limit of detection was estimated to be 0.020 ppm. This method provides a sensitive, selective, rapid, and reproducible alternative to existing purification, separation, and detection techniques, such as differential pulse polarography and colorimetry, for determination of nicarbazin in chicken tissues. Identity of DNC is confirmed by subjecting the purified extracts to thermospray-LC/mass spectrometric analysis using negative-ion detection and selected ion monitoring. Three structural-indicating ions at m/z 302, 272, and 164 are monitored in the thermospray-mass spectrum which are characteristic of the DNC molecule.

Animals↗

PubMedDate not supplied

[Evaluation of seminal carnitine as a marker of epididymal function].

Carnitine is present in seminal fluid either as a free compound or in acetylated form, and as can be inferred from the latest studies, it is of epididymal origin. In the present study, a comparative analysis has been made between carnitine levels in a group of subjects made up of fertile males and another group composed of patients with varying degrees of oligo-asthenospermia. The levels of free carnitine were measured through the enzyme-colorimetry method of Marquis and Fritz. It was found that carnitine levels were significantly lower in the oligo-asthenospermic group, and that such levels decreased progressively as the degree of oligo-asthenospermia increased. On the other hand, a regression analysis showed an increase in carnitine values as seminogram parameters measuring sperm motility and maturation (vitality, active motility, hypo-osmotic test, sperm count per ml and total sperm count of ejaculate) increased. Such differences lead us to think that carnitine plays an important role in the maturation process and in development of sperm motility.

Biomarkers↗