Data from batch growth curves of mouse LS cells cultivated at controlled dissolved oxygen partial pressures were used to calculate the weight of cells produced per mole of adenosine triphosphate generated (YATP). These values agree well with those reported for bacteria. A theoretical relationship was developed which allowed the biosynthetic and maintenance energy requirements to be estimated. The biosynthesis of LS cells required 1.6 x 10-11 moles of ATP/cell. The maintenance energy, which is a function of growth rate, was 2.9 x 10-11 moles ATP/new cell when the mean generation time was 1.15 days. The proportion of the total energy used for maintenance under these conditions was 65%. This corresponds to a value of less than 10% for bacterial maintenance when the organisms are grown at near their maximum rate. A comparison of biosynthetic energy requirements indicates that bacteria and moulds require about 4 times as much energy as animal cells to generate the same weight of cell material. Possible explanations of this difference are discussed.
A 3‐liter culture vessel has been developed for the growth of animal cells in suspension at controlled pH and dissolved oxygen partial pressure (pO2). The culture technique allows metabolically produced CO2 to be measured; provision can be made to control the dissolved CO2 partial pressure. In cultures containing a low serum concentration, gas sparging to control pO2 was found to cause cell damage. This could be prevented by increasing the serum concentration to 10%, or by adding 0.02% of the surface‐active polymer Pluronic F68. The growth of mouse LS cells in batch culture without pO2 control was found to be limited by the availability of oxygen. Maximum viable cell populations were obtained when dissolved pO2 was controlled at values within the range 40–100 mm Hg.
Of the 65 328 pregnancies of South Australian mothers screened by the South Australian Maternal Serum Antenatal Screening (SAMSAS) Programme between 1 January 1991 and 31 December 1997, 3431 (5.25%) were declared at increased risk of fetal Down syndrome. Fetal or neonatal karyotype was determined in 2737/3431 (79.8%) of these pregnancies, including 16 with early fetal loss. Interrogation of the database of the South Australian Neonatal Screening Service showed 643 live-born infants whose phenotype was not subsequently questioned among the 694 pregnancies whose karyotype was not determined. Of the remaining 51/3431 pregnancies, 19 ended in early fetal loss without karyotyping and no newborn screening or other records could be found for 32 cases. The 129 instances of abnormal karyotype found were Down syndrome (84), trisomy 18 (four), trisomy 13 (three), triploidy (two), female sex chromosome aneuploidy (six) and male sex chromosome aneuploidy (five), inherited balanced rearrangements (19), mosaic or de novo balanced abnormalities (four) and unbalanced karyotypes (two). In the pregnancies declared at increased risk of fetal Down syndrome, only the karyotype for Down syndrome occurred with a frequency greater than that expected for the general, pregnant population.
SummaryA 3-liter culture vessel has been developed for the growth of animal cells in suspension a t controlled p H and dissolved oxygen partial pressure (~0 2 ) . The culture technique allows metabolically produced COz to be measured ; provision can be made to control the dissolved COz partial pressure. I n cultures containing a low serum concentration, gas sparging to control pO2 was found to cauae cell damage. This could be prevented by increasing the serum concentration to lo%, or by adding 0.02y0 of the surface-active polymer Pluronic F68. The growth of mouse LS cells in batch culture without pO2 control was found to belimited by the availability of oxygen. Maximum viable cell populations were obtained when diesolved pO2 was controlled at values within the range 40-100 mm Hg.
A 3-liter culture vessel has been developed for the growth of animal cells in suspension at controlled pH and dissolved oxygen partial pressure (pO(2)). The culture technique allows metabolically produced CO(2) to be measured; provision can be made to control the dissolved CO(2) partial pressure. In cultures containing a low serum concentration, gas sparging to control pO(2) was found to cause cell damage. This could be prevented by increasing the serum concentration to 10%, or by adding 0.02% of the surface-active polymer Pluronic F68. The growth of mouse LS cells in batch culture without pO(2) control was found to be limited by the availability of oxygen. Maximum viable cell populations were obtained when dissolved pO(2) was controlled at values within the range 40-100 mm Hg.
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