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Peritoneal dialysis effluent, cytokine levels, and peritoneal mesothelial cell viability in CAPD: a possible relationship.

Recent studies have emphasized the role of peritoneal mesothelial cell (PMC) in peritoneal immune defense mechanisms in continuous ambulatory peritoneal dialysis (CAPD). The aim of this study was to evaluate a possible relationship between peritoneal dialysis effluent (PDE), cytokine (Cy) levels, and PMC viability and their impact on peritonitis morbidity. Fifteen patients initiating CAPD for end-stage renal failure participated in the study. The following parameters were evaluated: (1) the levels of interleukin-1 beta (IL-1 beta), tumor necrosis factor-alpha (TNF-alpha), interferon-gamma (IFN-gamma), interleukin-6 (IL-6), and interleukin-8 (IL-8) in PDE samples taken 7 days after initiating CAPD, at the end of the first, third, and sixth month of CAPD (determined by a solid phase enzyme amplified sensitivity immunoassay EASIA); (2) peritoneal mesothelial cell viability [determined by the release of lactate dehydrogenase (LDH) and by trypan blue extrusion test] by isolating and culturing peritoneal mesothelial cells at the moment of the placement of the peritoneal catheter and at the sixth month of CAPD; (3) peritonitis incidence during the 24 months after starting CAPD. At the first month of CAPD in all patients there was a slight increase in PDE IL-1 beta and TNF-alpha levels, while other Cy were almost undetectable. Time course studies showed that in 10 patients (Group I) there was a significant increase in PDE levels of IL-6, IL-8, and INF-gamma (p < 0.0005) in comparison to other Cy and a good PMC viability. In the other 5 patients (Group II) there were higher PDE levels of IL-1 beta and TNF-alpha (p < 0.0005). This was associated with a marked reduction in PMC viability determined by the release of LDH and by the trypan blue extrusion test. During the 24 months after starting CAPD, incidence of peritonitis was one episode per 24 patient-months in Group I and one episode per 9.2 patient-months in Group II. Our results show that from the beginning of CAPD there are distinct patterns of Cy in the PDE that correlate with a different PMC viability and peritonitis morbidity. Thus the analysis of the above-mentioned parameters may be useful in the early identification of the risk of peritonitis, thus allowing preventive measures.

Cell Survival↗

Effects of superporous hydrogels on paracellular drug permeability and cytotoxicity studies in Caco-2 cell monolayers.

The aim of this study was to evaluate the effect of superporous hydrogel (SPH) and SPH composite (SPHC) as permeation enhancers for peptide drug delivery on Caco-2 cell monolayers. Moreover, the cytotoxic effects of these polymers were also studied using trypan blue test, MTT assay and propidium iodide staining. Transepithelial electrical resistance (TEER) studies revealed that both SPH and SPHC polymers were able to decrease TEER values to about 40% of initial values, indicating the ability of these polymers to open tight junctions. Recovery studies of TEER showed that the effects of polymers on Caco-2 cell monolayers were reversible, indicating viability of the cells after incubation with polymers. Both polymers were able to enhance the transport of the hydrophilic marker 14C-mannitol up to 2.7 and 3.8-fold in comparison to the control group. The cumulative transport of fluorescein isothiocyanate labelled dextrans with a molecular weight of 4400 Da (FD4) and 19600 Da (FD20) was enhanced by SPH and SPHC polymers by opening of tight junctions; however, this enhancement was inversely proportional to the molecular weight of marker compounds. Cytotoxicity studies confirmed that the transport enhancing properties of SPH and SPHC polymers were not caused by damage of the Caco-2 cell monolayers. The cells were able to exclude trypan blue as well as propidium iodide after incubation with SPH and SPHC polymers. MTT assay showed that the number of viable cells was higher than 95% after incubation with SPH and SPHC polymers. This indicates that the mitochondrial metabolic activities of the cells were preserved after application of the polymers.

Acrylic Resins↗

Deep anterior lamellar keratoplasty for keratoconus.

PURPOSE: To investigate surgical outcomes after deep anterior lamellar keratoplasty (DALKP) in eyes with keratoconus. METHODS: Retrospective review of 127 eyes of 118 keratoconus patients who underwent DALKP at King Khaled Eye Specialist Hospital, Riyadh, Saudi Arabia between January 1, 1998 and November 30, 2001. The mean age of all patients was 25.9 years (range 11-70 years). The mean follow-up for all patients was 10.9 months (range 4-61 months). Baring of Descemet's membrane (DM) during DALKP was achieved in 47 (37%) eyes; some stroma was left during operation in the remaining 80 (63%) eyes. Snellen visual acuity, intraoperative complications, and postoperative graft status were assessed. RESULTS: At the last follow-up visit, 74% of all eyes were able to achieve a best-corrected visual acuity of 20/50 or better. This level of improvement was more statistically significant with baring of DM (P = 0.005). Intraoperative perforation of DM occurred in 16 (13%) cases and was statistically significant in eyes with deep corneal scars (P = 0.012). However, this perforation did not seem to have an impact on the final visual acuity (P = 0.48). Main graft-related complications included graft-host vascularization (7/127), stromal graft rejection (4/127), graft infection (1/127), and persistent epithelial defect (1/127). CONCLUSIONS: Deep lamellar keratoplasty provides a safer and successful alternative to penetrating keratoplasty for keratoconus patients but remains a challenging procedure. Endothelial graft rejection is absent after DALKP. However, stromal graft rejection, although very rare, does occur.

Adolescent↗

A novel lymphocyte toxicity assay to assess drug hypersensitivity syndromes.

OBJECTIVES: To validate the novel lymphocyte toxicity assay (LTA) based on the mitochondrial succinate dehydrogenase (SDH) activity vs. the LTA by using trypan blue exclusion and to determine the utility of the assay to confirm drug hypersensitivity syndrome (DHS) to sulphonamides (SMX) and aromatic anticonvulsants. METHODS: Incubation of patient lymphocytes, with or without murine hepatic microsomes with anticonvulsants or SMX. The viability of lymphocytes was based on SDH activity that can be measured spectrophotometrically. The percentage of cells displaying cytotoxicity compared to controls (cells treated only with drug) was calculated. Seventy-two immunocompetent and 16 immunocompromised (HIV) patients with DHS to SMX were sampled. The results were validated vs. 26 controls that had not experienced DHS to SMX. Sixty-two patients who had DHS to anticonvulsants were compared with 24 controls that did not have any DHS to the same anticonvulsants. RESULTS: The results showed a very good percentage of sensitivity 98 and specificity 96 with a kappa-score of 0.96. LTA higher than 13.5% was considered positive for the immunocompetent population and LTA higher than 22% was positive for the immunocompromised population. In two of the 26 controls, LTA was positive. CONCLUSION: The high quantitative kappa-value 0.96 emphasizes that the novel LTA is at least as good as the trypan blue assay. The latter is labor intensive, time consuming, and prone to human error. The new assay is objective, faster, and has been reproducible in assessing cytotoxicity.

Adolescent↗

Simple detection method for distinguishing dead and living yeast colonies.

A rapid and simple assay was developed for detection of yeast colonies containing dying or dead cells. Methylene blue, phloxin B, rose bengal and trypan blue at concentrations of 5-10 micromol l(-1) were shown to stain non-viable cells in colonies of Saccharomyces cerevisiae, Schizosaccharomyces pombe, Candida albicans and Filobasidium capsuligenum without staining or affecting the viability of living cells of the colonies.

Basidiomycota↗

Inverse relationship between megakaryocyte buoyant density and maturity.

We examined the relationship between rat megakaryocyte buoyant density and maturation stage in continuous Percoll density gradients. An average of 88% of megakaryocytes had buoyant densities less than 1.054 g/ml. There was an inverse relationship between megakaryocyte buoyant density and maturation. Morphologically mature forms comprised 90% of the megakaryocytes with buoyant densities of 1.030-1.033 g/ml. In contrast, immature morphology was present in three-quarters of megakaryocytes with buoyant densities of 1.042-1.046 g/ml. These morphological findings were confirmed by [3H]thymidine labelling studies. Cell viability assessed by trypan blue exclusion was highest among more dense megakaryocytes of which the majority were immature. The lowest trypan blue exclusion was found in the less dense, predominantly mature megakaryocytes indicating that these cells are more susceptible to membrane damage during marrow suspension. Megakaryocyte DNA content distributions and platelet antigen levels, determined by two-colour flow cytometry, were also related to megakaryocyte density; the more dense megakaryocytes showed an approximately two-fold higher proportion of 8N cells and less platelet antibody binding than did less dense megakaryocytes. These studies suggest that megakaryocytes can be fractionated according to their buoyant densities into immature and mature populations suitable for molecular studies of differentiation.

Animals↗

Inhibition of viral interferon induction in mammalian cell cultures by azo dyes and derivatives activated with rat liver S9 fraction.

Four azo dyes (Benzopurpurine 4B, trypan blue, Direct Blue 15, and Congo red) and their derivatives (o-tolidine, o-dianisidine, and benzidine) were studied for their effect on induction of interferon by influenza virus in mammalian, Rhesus monkey kidney (LLC-MK2), cell monolayers. Whereas Benzopurpurine 4B, Direct Blue 15, and Congo red inhibited viral interferon induction from approximately 35 to 60%, negligible inhibition was noted with trypan blue and other derivative compounds. By comparison, when rat S9 fraction was used for enzymatic activation of azo dyes and derivatives, interferon inhibition was significantly depressed moreover (P less than 0.01 to less than 0.0001) by all chemical compounds. The concentration of rat S9 (0.5%) used for metabolic activation of dyes and congeners was critical because concentrations greater than 0.5% of S9 per se inhibited the interferon induction process. Uninduced hamster S9 and both Aroclor 1254-induced hamster and rat S9 fractions were all comparable in their ability to activate the chemical compounds tested. That potential mutagenic and carcinogenic chemicals which require metabolic activation can be discriminated on the basis of interferon induction inhibition in eukaryotic cell cultures augurs for the usefulness and credibility of this system.

Animals↗

Zonation of glycogen and glucose syntheses, but not glycolysis, in rat liver.

We have investigated the cause of defective glycogen synthesis in hepatocyte preparations enriched with cells from the periportal or perivenous zones obtained by the methods of Lindros & Penttila [Biochem. J. (1985) 228, 757-760] and of Quistorff [Biochem. J. (1985) 229, 221-226]. A modified procedure which yields hepatocytes capable of consistent rates of glycogen synthesis is described, and the rates of glucose and glycogen syntheses and of glycolysis in hepatocytes from the two zones are compared. Glycogen synthesis in cells was greatly impaired by very low concentrations (0.01-0.05 mg/ml) of digitonin, which had little effect on glucose and protein syntheses and Trypan Blue exclusion. Cells exposed to such low concentrations of digitonin lose all their synthetic capacity and ability to exclude Trypan Blue when incubated with EGTA, which does not affect cells not exposed to digitonin. With a modified procedure based on this phenomenon, our study reveals that hepatocyte preparations enriched with cells from the periportal zone synthesized glucose from lactate and alanine at rates twice those by cells from the perivenous zone, whereas the rate of glycogen synthesis from C3 precursors in periportal cells was 4 times that in the perivenous preparations. With substrates entering the pathway at the triose phosphate level, gluconeogenesis in periportal-cell preparations was 20% higher, and glycogen synthesis was twice that in perivenous preparations. Glycolysis was studied by the formation of 3HOH from [2-3H]glucose, the yield of lactate, and the conversion of [14C]glucose into [14C]lactate. In cell preparations from both zones glycolysis by all criteria was negligible at 10 mM-glucose, but was substantial at higher concentrations. However, there was no difference between the zones. We confirm that the capacities for glucose and glycogen syntheses in periportal cells are higher than in perivenous cells, but that at physiological glucose concentrations there is negligible glycolysis in liver parenchyma in both zones. The metabolic pattern in the perivenous cells is not glycolytic.

Animals↗

Heat shock inhibits the hypoxia-induced effects on iodide uptake and signal transduction and enhances cell survival in rat thyroid FRTL-5 cells.

Chronic hypoxia inhibits rat thyroid function in vivo. To determine possible mechanisms, we studied the effect of hypoxia on iodide uptake, the involvement of second messengers, and cell membrane permeability in rat thyroid FRTL-5 cells. Since sublethal heat stress protects tissues from ischemia, we also determined effects of heat stress. The initial rate of iodide uptake in untreated cells was between 12.98 and 15.28 pmol/micrograms DNA/min. Hypoxia (5% O2) increased the rate of uptake in a time-dependent manner. Heating cells at 45 degrees C for 15 min (heat shock) prior to exposure to hypoxia for 3 days inhibited the increase in the initial rate of I-uptake. Using fura-2, we found that the resting [Ca2+]i in suspended FRTL-5 cells was 65 +/- 7 nM (n = 16). [Ca2+]i was not increased in cells exposed to hypoxia for 1 day, while a 3-day exposure increased [Ca2+]i by 43 +/- 4% (p < 0.05); no additional increase occurred after 7 days of exposure. When cells were heated prior to hypoxia exposure for 3 days, the hypoxia-induced increase in [Ca2+]i did not occur. Similar observations were found with inositol trisphosphates (InsP3). Exposure of cells to hypoxia for 3 days increased InsP3 from 0.08 +/- 0.02 (n = 5) to 0.32 +/- 0.04% total cpm (n = 5, p < 0.05), but sublethal heating of cells prior to hypoxia exposure prevented the increase. Three-day hypoxia increased PKC activity in the membrane fraction (from 67 +/- 7 to 86 +/- 4% of total activity, p < 0.05), and heat shock inhibited these changes also. Immunoblots showed that hypoxia treatment alone and heat shock plus hypoxia resulted in the translocation of PKC-alpha, -delta, -epsilon, and -zeta isoforms, whereas heat shock alone translocated only PKC-beta I, -beta II, and -zeta. Cell membrane integrity was assayed by trypan blue exclusion. Hypoxia alone for 3 days did not affect membrane permeability, but only 49 +/- 3% of cells excluded trypan blue when a 3-day hypoxia exposure was followed by a 6 h reoxygenation. Heat shock prior to hypoxia and reoxygenation protected cell membrane function. Heat shock also induced heat shock protein 70 kDa (HSP-70) synthesis at the transcriptional level. Results suggest that heat shock protects FRTL-5 cells from hypoxic injury, perhaps by inhibiting the initial rate of iodide uptake and second messengers. It is likely that HSP-70 plays an essential role in the process of protection.

Animals↗

[Preservation of human corneas in organ culture: technical protocol].

Using organ-culture preservation human corneas were preserved up to 5 weeks in a modified tissue culture medium at 37 degrees C. The endothelial viability was examined after staining with trypan-blue 0.3%, after determination of endothelial cell density and cell loss and by light microscopy after staining with trypan-blue 0.3% and alizarin red 1%. The biochemical analysis of the medium (pH, glucose, lactate) has allowed the evaluation of three kinds of storage. The influence of time preservation on the endothelial viability and the metabolic conditions are determined. At the end of this study a clinical trial is proposed.

Cell Count↗

Inorganic mercury pre-exposures protect against methyl mercury toxicity in NSC-34 (neuron x spinal cord hybrid) cells.

A neuron spinal chord x hybrid (NSC-34) cell culture derived from neonatal mouse was characterized for studies on mercury toxicity. Exposure of NSC-34 cells to methyl mercury chloride (MeHgCl) (0-16 microM) resulted in significant dose-dependent cell damage and death (P < 0.05). MeHgCl was more toxic than inorganic mercury (Hg2+) for both the NSC-34 cells and its parent neuroblastoma cell line N18TG-2 (P < 0.05). Hg2+, but not ZnCl2 or MeHg exposure induced metallothionein (MT) (P < 0.05). To mimic the increase in Hg2+ in the mammalian brain with long term MeHg exposure, the cells were treated with 1 microM mercuric chloride (HgCl2) for five passages before exposure to MeHgCl (1-16 microM) for 48 h. MeHgCl toxicity was measured by trypan blue exclusion, reduction of resazurin dye and acid phosphatase activity. Pre-exposure to HgCl2 lessened the toxicity as shown by trypan blue exclusion (P = 0.0559) and reduction of resazurin (P = 0.0001). Pre-exposure to HgCl2 also resulted in induction of MT (P = 0.0066) and lessened the decrease of reduced glutathione (GSH) (P = 0.0013). These results suggest that MT and GSH may play a protective role in methyl mercury induced neurotoxicity of neuron spinal chord cells. The NSC-34 hybrid cell line can be a useful model for the study of MeHg neurotoxicity.

Acid Phosphatase↗

Improvement of human corneal endothelium in culture after prolonged hypothermic storage.

PURPOSE: To evaluate whether the organ culture method for human cornea preservation may be applied to corneas stored for several days at 4 degrees C. METHODS: The cell density, viability, and morphology of corneal endothelium were examined in 140 human corneas stored at 4 degrees C for the minimal time required for transport to the bank and for the preliminary controls of cornea status (1.6 +/- 1.1 days) and in 46 corneas preserved at 4 degrees C for 6.1 +/- 1.9 days in Optisol-GS. The evaluation was repeated after 19.7 +/- 9.1 days of incubation at 31 degrees C in a culture medium containing 2% newborn calf serum. RESULTS: After the hypothermic storage the corneal endothelium had a mean density of 2475 +/- 159 cells/mm2 without significant difference between the short and the long-term incubation. Several corneas of the two groups showed signs of endothelium degeneration and were positive to trypan blue test. After the incubation at 31 degrees C, the corneas with endothelial degeneration decreased by 52.2% and those positive to trypan blue decreased by 21.7%. Polymorphism (enlarged endothelial cells) increased from 9.6% to 14.5% of the corneas. The remodeling of the endothelium led to a 6.7% decrease in cell density. These results were similar after short-term and long-term storage at 4 degrees C. CONCLUSIONS: Organ culture was effective in improving corneal endothelium when the hypothermic storage was prolonged to the upper temporal limit for this procedure (7-10 days). These results may encourage the possibility of an eye bank to allocate the available cornea pool, thus decreasing the risk of discarding precious material.

Aged↗

Radiation sensitivity and the status of some radiation sensitivity markers in relatively sensitive lymphoid cells.

The most commonly used indicators of ionizing radiation exposure are cytogenetic measures and survival parameters. All these methods have their advantages, disadvantages and uncertainties, such that better biological estimators of the absorbed dose, especially in the low dose range, are being sought. In this study we analyzed apoptosis and several proteins involved in the regulation of apoptosis as possible indicators of irradiation after relatively small doses (0.1-2 Gy) of X-rays. The studies were carried out in seven lymphoid cell lines: two mouse lymphoma L5178Y, the human pre-B cell leukemia Reh, and four human Epstein-Barr virus-transformed lymphoid cell lines (two apparently normal and two Ataxia-telangiectasia (AT)). We detected apoptosis with the in situ terminal deoxynucleotidyl transferase assay and flow cytometry, and measured the expression of several apoptotic-regulatory proteins (Bcl-2, Bax, Bclx, NF kappa B) with Western blotting. The cytokinesis-block micronucleus assay, comet assay as a measure of DNA damage, and trypan blue survival test were also done for comparison Although for the most of examined parameters of radiation sensitivity: i.e. micronucleus assay, trypan blue test and percentage of apoptosis--there were observed clear dose-effect relationships for all cell lines examined, we did not find agreement between values for these measured parameters. There are marked differences in both timing of apoptosis and percentage of apoptotic cells. Variation in the apoptotic fraction in the controls for different sets of experiments is not very pronounced. There is however considerable variation for the same parameters in irradiated cells, possibly due to their cell cycle status during irradiation, as the cultures were not synchronized. Overall, neither the numbers of apoptotic cells nor the expression of apoptosis-related proteins, nor DNA repair can serve as dose estimators or sensors for these lines, but still these parameters can give valuable supplementary information about radiation sensitivity.

Animals↗

[DNA degradation and changes in the permeability and form of Ehrlich ascites tumor cells when incubated in an anaerobic medium without glucose].

After a 3-hour incubation of the Ehrlich ascite tumor cells in buffered Hanks solution, without glucose and oxygen, the extensive cell injuries were observed. The time-course of appearance of these injuries was as follows: cell blebbing, staining of the cells with trypan blue, and then their staining with ethidium bromide. The DNA degradation registered with fluorometric method coincided in time with cell staining with trypan blue. All injuries (except DNA degradation) were delayed at pH 6.0 compared with those at pH 7.3. Glucose added to the cell suspension greatly protected the cells from these injuries, although DNA degradation at pH 6.0 in these conditions was a little higher than that at pH 7.3.

Anaerobiosis↗

[Application of terms of probability theory in embryology and teratology].

The aim of the paper was to show that accurate morphological statements can be made with the help of simple concepts of the theory of probability. Binomial distribution was used to find out whether the number of male and female births in large families was random or whether a particular disposition to boys/girls was to be assumed. It was found that the relation was random as a rule. A second question was that of the connection between a number of simultaneous variations and deformities. After the injection of trypan blue, combined deformities were studies in rats and found to be independent of each other, i.e. all had been directly caused by trypan blue.

Abnormalities, Severe Teratoid↗

Green fluorescent protein: A novel viability assay for cryobiological applications.

Assessment of tissue viability following the application of a freezing protocol is challenging due to the paucity of viability assays that can be used dynamically, in situ. Cells transfected with a green fluorescent protein (GFP) vector actively produce GFP, which is retained intracellularly. Because of its constitutive and heritable expression, GFP fluorescence of transfected cells may have significant utility as a viability assay for cells within tissues. As a first step toward application to tissues, this work seeks to establish the validity of this GFP-based assay in cell suspensions by comparing the results to other accepted measures of viability. To the authors' knowledge, this is the first use of GFP in cryobiology applications. Intracellular GFP fluorescence was evaluated following slow freezing. Nontransfected and GFP-transfected rat 3230 adenocarcinoma (R3230AC) cells were frozen at 1 degrees C/min to minimum temperatures between -5 and -30 degrees C and then immediately thawed in a 37 degrees C water bath. Samples were assayed using the common viability indicators trypan blue and ethidium bromide (EtBr). A regression analysis of recovery measured with the GFP assay as a function of recovery measured with a trypan blue assay gave a correlation coefficient of 0.97. A similar correlation coefficient, 0.95, was determined for recovery assessed by the GFP assay as a function of recovery measured by an EtBr assay. Nontransfected and GFP-transfected cells responded similarly to slow freezing, indicating that GFP transfection did not significantly alter the response of cells to typical freezing conditions. The excellent correlation of GFP assay results with those of two common viability assays suggests that the GFP-based assay is valid for cells and that further development of a tissue viability assay based on transfection is appropriate.

Animals↗

A rapid enzymatic method for the isolation of defined kidney tubule fragments from mouse.

The increasing number of available genetically manipulated mice makes it necessary to develop tools and techniques for examining the phenotypes of these animals. We have developed a straightforward and rapid method for the isolation of large quantities of single tubule fragments from the mouse kidney. Immunohistochemistry, electron microscopy, and fluorescence microscopy were used to evaluate the viability, functional characteristics, and morphology of proximal tubules (PT), and collecting ducts from cortex (CCD) and inner stripe of the outer medulla (ISOMCD). Tubules were isolated using a modified collagenase digestion technique, and selected under light microscopy for experimentation. Electron microscopy and trypan blue exclusion showed that a large portion of unselected proximal tubules were damaged by the digestion procedure. The selected tubules, however, all excluded trypan blue, indicating that the plasma membrane had remained intact. Immunocytochemistry on isolated CCD showed normal distribution of H(+)-ATPase, pendrin, and anion exchanger-1 (AE-1) staining. The pH-sensitive dye 2',7'-bis(2-carboxylethyl)-5(6)-carboxyfluorescein (BCECF) was used to measure Na(+)-dependent and -independent intracellular pH (pH(i)) recovery rates in PT, and in single intercalated cells of CCD and ISOMCD fragments. Na(+)-dependent pH(i)-recovery was 0.144+/-0.008 (PT), 0.182+/-0.013 (CCD), and 0.112+/-0.010 pH units/min. (ISOMCD). Na(+)-independent pH(i) recovery was found in all three segments (PT: 0.021+/-0.002, CCD: 0.037+/-0.002, ISOMCD: 0.033+/-0.002 pH units/min) and was sensitive to concanamycin. In summary, we have developed a new technique for rapid and straightforward preparation of large quantities of defined tubule fragments from mouse kidney. Using this technique, the first measurements of plasma membrane vacuolar H(+)-ATPase activities in mouse PT and collecting duct were made. This technique will facilitate further characterization of kidney function in normal and genetically manipulated animals.

Animals↗

High radiosensitivity of the MOLT-4 leukaemic cell line.

Radiation survival of MOLT-4, a leukaemic T-lymphocyte cell line, was measured by counting colonies formed in 0.8 per cent methyl cellulose. The survival curve was a simple exponential and showed the cells to be radiation sensitive, with D0 = 0.49 +/- 0.02 Gy and extrapolation number n = 0.92 +/- 0.09. No increase in survival as measured by colony-forming ability or trypan blue dye exclusion was seen when the dose was split into two fractions, separated by a 5 h incubation period. Electron microscopy and trypan blue dye exclusion showed that 5 h after exposure to high doses, MOLT-4 cells began to die and displayed condensed, marginated chromatin and cellular vesiculation.

Adult↗