HeLa cells culture

Regulation of alkaline phosphatase activity was discussed by Cox and Griffin 65). Steroids such as hydrocortisone or prednisolone (1 (ig/ml of medium) can induce a 3- to 20-fold rise in certain HeLa cell cultures, while other cell lines are induced by 15 mM phenyl phosphate. Recently, it has been shown that fibroblast cell cultures are also stimulated by prednisolone (( ( ). According to one report, Pi may have a control function here a decrease in the level of rat kidney P produced by a low phosphate diet was accompanied by an increase in alkaline phosphatase. Nine other enzymes monitored were unaffected 67). 

So far the only well-characterized uncompetitive inhibitor is L-phenyl-alanine, shown to be uncompetitive for intestinal (180) and placental phosphatases (42). By contrast, D-phenylalanine has no inhibitory effect. The L isomer apparently acts by preventing the breakdown of phosphoryl phosphatase (170), possibly by blocking the acceptor site mentioned in Section III,D,4. A list of concentrations required to produce 50% inhibition of a wide variety of phosphatases showed that all the enzymes were affected though there was a spread in susceptibilities from 0.8 mM for HeLa cell culture phosphatase to 26 mM for mouse intestinal phosphatase... 

A HeLa cells cultured in medium containing 5 mM sodium butyrate and 50 ixCi/mL N-[acetyl-sH]-D-mannosamine after 24 hr, one set of cells harvested and medium replaced with fresh medium with and without 0.5 pg/mL cycloheximide on the other two sets, which were harvested after another 19 hr cells then analyzed for radioactive GM3. B Essentially same as A except the cells were cultured in unlabeled medium and assayed for sialyltransferase activity. C same as B except the cells were assayed for GM3-... 

As previously mentioned, degradable microspheres have gained attention as promising delivery vehicles for steroids in postmenopausal therapy. Copolymers of CL and d,l-LA were used to prepare microspheres for prolonged release of progesterone and [5-estradiol. The system offered a constant release for up to 40 days in vitro and 70 days in vivo [226]. Similarly, PCL copolymers have been considered useful for androgen replacement therapy in the treatment of aging men with a testosterone deficiency. Micelles of PCL-block-poly(ethylene oxide) released dihydrotestosterone in a controlled fashion over 30 days. The biocompatibility was confirmed in vitro in a HeLa cell culture [227]. 

HeLa cell cultures are propagated in Dulbecco s Modified Eagle Medium (D-MEM) (500 mL) (Gibco) supplemented with 10% fetal bovine semm (FBS, Bio West), 5 mL MEM non-essential amino acids (100 x ) (Gibco), 5 mL sodium pyruvate MEM (100 m /. Gibco), and 5 mL Penicillin-Streptomycin-Neomycin (PSN) Antibiotic Mixture (Gibco). 

The cytotoxicity of distamycin derivatives was estimated on the basis of the morphological modifications induced in HeLa cell cultures, after incubation for 40 h in Hanks saline solution + 0.5 % lactalbumin hydrolysate + 5 % calf serum (HLS). Assay on vaccinia virus Cultures of HeLa cells (grown in HLS medium) or mouseembryo cells (grown in HLS medium plus 0.1 % yeastolate) infected with vaccinia virus (Strain WR/ATCC) were used. Preliminary assays were made according to Herrmann et al.° Subsequent studies were carried out by assessing the inhibition of plaque formation (ECP) as well as the inhibition of infectious virus production in test tube cultures treated with the compounds for 40 h after the absorption of the virus. 

Treatment with AS-6 caused a decrease in cholesterol levels [150, 151], but it is unclear whether this property relates to its ability to enhance insulin action on lipid metabolism or results from other actions. Although ascochlorin originally was associated with cytotoxic effects in HeLa cell cultures [ 143], chronic studies (10 weeks) in mice with AS-6 showed no effects on food consumption or toxic signs in liver [147]. 

Cytotoxicity and antiviral activity of compounds in HeLa cell cultures ... 

The thioredoxin system, composed of nicotinamide adenine dinucleotide phosphate (reduced form), thioredoxin and thioredoxin reductase, may be involved in the cellular sensitivity to cis-diamminedichloroplatinum (Sasada et al. 1999). HeLa cells cultured with cisplatin showed a time-and dose-dependent reduction of intracellular thioredoxin reductase activity, which was well correlated with the decrease in cell viability after exposure to cisplatin. In a cell-free system, cisplatin was found to directly inactivate the reduced form of purified human thioredoxin reductase. The cis-platin-resistant variants of HeLa cells, estabUshed by continuous exposure to cisplatin, exhibited an increased expression and activity of thioredoxin reductase as well as thioredoxin compared with the... 

Figure 6.2.2.1 Size of cellular adhesion area at various distances between the eiectrode tip and the substrate surface during the electrochemical treatment, (a) Phase contrast micrograph of HeLa cells cultured for 24 h on the BSA-coated glass substrate, which was pretreated by a Br - oxidation pulse of 30 sec at the tip-surface distance indicated in the micrograph, (b) Plots of the radius of the cell adhesion area versus the distance of electrode tip-substrate surface for the electrolysis periods of 10 sec (4) and 30 sec (O). Error bars for the plots were calculated from the standard deviation of at least four cellular patterns. Solid curves were calculated assuming a diffusion-limited surface reaction. [Reproduced with permission from H. Kaji, K. Tsukidate, T. Matsue, M. Nishizawa, J. Am. Chem. Soc. 126, 15026 (2004). Copyright 2004, American Chemical Society] (for colour version see colour section at the end of the book).

DeCarli et al., 1963). Also, hormone induction of alkaline phosphatase in HeLa cell cultures has been extensively studied (GriflFen and Cox, 1966 Melnykovych et al., 1967) with attention to chromosomal number (GriflFen and Bottomley, 1969). In the area of development, the diflFer-entiation of alkaline phosphatase has been evaluated (Moog et al., 1969) and in pregnancy, interesting work in the rat (Manning et al., 1969) and in the human (Posen et al., 1969 Fishman et al., 1972) have been conducted. Biochemical work has centered on the role of zinc (Simpson and... 

One of the original controlled studies on picornavirus cytopathic effects was performed by Ackermann et al. (1954) who, during investigation of the growth characteristics of poliovirus type 3 in HeLa cell cultures, noted a lack of parallelism in cellular injury and virus replication. These authors reported a latent period (before virus release) of 4-5 hr followed by gradual virus release during the ensuing... 

Ackermann, W. W., Rabson, A., and Kurtz, H., 1954, Growth characteristics of poliovirus in HeLa cell cultures. Lack of parallelism in cellular injury and virus increase, J. Exp. Med. 100 437. 

Fig. 4. Morphological changes in type C adenovirus-infected HeLa cells. (A) Uninfected HeLa cells in monolayer culture. Magnification, x 1.2 insert, x 52. (B) HeLa cell culture 3 days after Ad5 infection. Magnification, x 1.2 insert, x 52. From Periera (1958).

The template properties of virus RNA are manifested, as in the case of messenger RNA of the host cell, during its interaction with ribosomes. Just as in the case of normal intracellular synthesis, polysome structures of the type illustrated in Fig. 8 are formed under these circumstances. The formation of active polysomes during interaction between virus RNA and cell ribosomes have been studied in particular detail in the case of poliovirus infections of HeLa cell cultures (Penman et al., 1963 Scharff et al., 1963 Rich et al., 1963). In this condition virus-specific polysomes are formed which are much bigger than the polysomes of uninfected HeLa cells, as a result of the polycistron character of virus RNA. Some of them contained as many as 60 ribosomes. 

Matsumaea et al. [110] worked out an SECM method for detecting the intracellular NQO enzyme activity of a single cell. They employed menadione mediator for shuttling electrons through the cell membrane and ferticyanide as hydrophilic second mediator for increasing the electron exchange rate at the platinum surface of the microtip. In this study HeLa cells cultured on plastic Petri dish were tested and disc-type Pt electrode with a diameter of 20 pm (RG = 2) was used as SECM tip. 

Grow HeLa cells to subconfluence (80-90 %) in T75 cell culture flasks using HeLa cell culture medium. 

Wash the cells with PBS, detach with trypsin/EDTA and resuspend the detached cells in fresh HeLa cell culturing medium... 

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