Minimum Cell Density

Abstract: The effects of iron on the growth and biosynthesis of pigment in two strains of Dunaliella salina were investigated.The results indicated that for D.salina OUN04,the maximum cell density of 1.115×106 cell/ml was detected in 0.05 mmol/L iron group,followed by 0.01 mmol/L iron group.The control group had the maximum cell density of 8.29×105 cell/ml.The 0.25 mmol/L iron group had the minimum cell density of 7.0×105 cell/ml in all test groups,indicating that the growth of D.salina was inhibited by high iron content.The highest β-carotene content of 83.2 mg/g was observed in 0.25 mmol/L iron group and the control group had the minimum of 63.4 mg/g.In the first 1~3 days,the absorption rate of iron was slow,while it was fast in 4~7 days,then declined in the last 3~4 days.For D.salina OUN09,the maximum cell density of 1.31×106cell/ml was observed in 0.05 mmol/L iron group.The control group had the cell density of 1.185×106 cell/ml and the 0.25 mmol/L iron group had the minimum cell density of 1.023×106 cell/ml.The maximum β-carotene content of 130.2 mg/g was found in 0.05 mmol/L iron group and that of 70.4 mg/g in control group.The variety pattern of pH and the absorbed pattern of iron were similar to that of D.salina OUN04.

Abstract: DH82 Cell line has been utilized to grow Ehrlichia canis and RF/6A for drug evaluation in short-term cultures, as well as for replicating Anaplasma marginale. However, specific in vitro culture development conditions are unknown. Several experiments were designed to solve inquiries of such procedure. Both cell lines were acquired from ATCC and put into culture. Na Pyruvate, NaHCO3 and fetal calf serum were used to enrich MEM culture media and incubated at 37 °C on 5% CO2 - air humid mixture atmosphere. First assays used 24 well plates and were focused on determination of a minimum initial cell concentration and cell density. In the former, averages of 62,500 cell/well for DH82 & 8,836 for RF/6A; were found. Later, experiments to identify a minimum cell density started with 5, 10, 20 & 40 cells/mm2, harvesting with a EDTA-Trypsin solution when confluence be reached. Growth indexes of 3,319.32, 1,956.70, 870.73 & 422.14 times and of 62.38, 63.51, 25.31 & 12.16 times, were respectively found for DH82 & RF/6A cell lines. For kinetics studies, 35 mm O sterile Petri dishes were used. Cultures were set with 20 cell/mm2 seed density for DH82 and 10 cell/mm 2 for RF/6A. Dishes were randomly separated into two groups, with and without culture media periodical replacement. Maximum growth was observed at 336 and 315 h with 42.9 and 36.9 h doubling time in culture, respectively for DH82 & RF/6A cell lines. Generated data provided a model to define an in vitro growth pattern for future studies.

Abstract: Purpose Apparent diffusion coefficient (ADC) describes water diffusion within tissues. Previous studies report a negative linear correlation between minimum ADC and tumour cellularity in different types of gliomas, but there are no studies in oligodendroglial tumours. This study evaluated the relationship between ADC and tumour cellularity in oligodendroglial tumours characterized by genotype. Methods ADC was assessed in 17 patients with known 1p/19q status: 3 grade II oligodendrogliomas (OII), 9 grade II oligoastrocytomas (OAII), 5 grade III oligoastrocytomas (OAIII). Regions of interest were placed on ADC maps around tumour margins to generate mean tumour ADC, and over minimum and maximum tumour ADC. Histopathology assessment of tumour cellularity determined minimum, maximum and mean cell density in serial stereotactic biopsies. Results 1p/19q loss was present in 2/3 OII, 5/9 OAII, 2/5 OAIII. Grade III tumours had higher maximum cell density than grade II tumours (17.2 vs. 10.57%: Mann Whitney U; P = 0.20). Oligoastrocytoma were more likely to have a lower minimum cell density than oligodendrogliomas (Mann Whitney U; P = 0.032). There was no relationship between cell density and genotype. There was no linear correlation between mean ADC and mean cell density (Spearman’s rho; r = 0.486: P = 0.438), minimum ADC and maximum cell density (Spearman’s rho; r = 0.158: P = 0.660), and maximum ADC and minimum cell density (Spearman’s rho; r = 0.039: P = 0.985). Conclusions In oligodendroglial tumours there is no relationship between quantitative assessment of cellularity and ADC. This may reflect differences in oligodendroglial tumour biology compared to other gliomas, although the composition of the extracellular matrix may influence ADC more than cellularity.