Cell multiplicity

Bastenie and Zylberszac, in a general article on the former subject, point out that colchicine (1) brings into mitosis all cells which are in karyo-kinetic inuninence but which normally would slowly and successively reach mitosis, and (2) stops them at this stage. This has made possible a technique which picks out cell multiplication and can be used for detecting many types of hormonal stimulation, e.g., the action of follicular hormone and other oestrogens. ... 

The blastocyst is an early embryonic stage in mammalian development. Murine blastocysts can be harvested at day 3.5 p.c. Their inner cell mass contains embryonic stem cells. Multiple murine embryonic stem cell lines have been established. Embryonic stem cells carrying genetically engineered mutations are injected into blastocysts, which are subsequently implanted into pseudopregnant foster mothers. 

Cell division cycle Cell proliferation Cell multiplication... 

Cell Adhesion Molecules Cell-cycle Arrest Cell Cycle Checkpoints Cell Cycle Control Cell Division Cycle Cell Multiplication Cell Proliferation Cellular Immmunity Central Core Disease (CCD)... 

From this perspective it would be interesting to discover if there is a relationship between the substrate used and the concentration of free CoA under conditions of unlimited growth. If there is, depending on the source of carbon and energy used and the K value of the 3-ketothiolase for CoASH, cell multiplication and poly(3HB) accumulation can occur simultaneously [60,61]. If this enzyme is not involved, poly(3HB) [29] and other polyesters [28,29] can also be synthesized during growth. 

Poly(3HB) is usually produced in a batch or fed-batch regime. These types of process control are derived from the general observation that overproduction of poly(3HB) occurs when cell multiplication is limited by an essential nutrient and the carbon substrate is available in excess. Batchwise production has an advantage in that a high poly(3HB) content can be reached. One disadvantage is the quality of the product, which can vary from one batch to the next. This can be overcome by a continuous process. Continuous production is basically possible if ... 

Figure 1 The SILAC method for comparative proteomics. A real experiment requires collection of thousands of mass spectra corresponding to different peptides. In the case portrayed, the drug has lowered the abundance of the affected protein in the treated cells compared to the control cells. Multiple peptide fragments of the affected protein would show this effect, supporting the conclusion that the protein was affected.

ISO 10712 (1995) Water quality Pseudomonasputida growth inhibition test (Pseudomonas cell multiplication inhibition test). International Organization for Standardization, Geneva... 

Rasmussen, L. and Kludt, T. A. (1970). Particulate material as a prerequisite for rapid cell multiplication in Tetrahymena culture, Exp. Cell Res., 59, 457-463. 

Initially, the cells require a period of time, the lag phase, to adjust to the altered environment. No cell multiplication occurs until the individual cells have almost doubled in size. After the adaptation is complete, the cells begin to reproduce exponentially. With each period of cell division, the population doubles. Some cells... 

Where Nc = initiator core multiplicity Nb = branch cell multiplicity NcNbM = number of covalent bonds formed/step... 

It is apparent that both the core multiplicity (Nc) and branch cell multiplicity (Nh) determine the precise number of terminal groups (Z) and mass amplification as a function of generation (G). One may view those generation sequences as quantized polymerization events. The assembly of reactive monomers [48, 78], branch cells [48, 83, 89] or dendrons [85, 90] around atomic or molecular cores... 

As a consequence of the excluded volume associated with the core, interior and surface branch cells, steric congestion is expected to occur due to tethered connectivity to the core. Furthermore, the number of dendrimer surface groups, Z, amplifies with each subsequent generation (G). This occurs according to geometric branching laws, which are related to core multiplicity (iVc) and branch cell multiplicity (iVb). These values are defined by the following equation ... 

Figure 1.21 Periodic properties for poly(amidoamine) (PAMAM) dendrimers as a function of generation G = 0-10 (I) flexible scaffolding (G = 0-3) (II) container properties (G = 4-6) and (III) rigid surface scaffolding (G = 7-10) various chemo/ physical dendrimer surfaces amplified according to Z = NCN where Nc = core multiplicity, Nb = branch cell multiplicity, G = generation...

Clark, H.F. and Diamond, L. Comparative studies on the interaction of benzpyrene with cells derived from poikilothermic and homeothermic vertebrates. II. Effect of temperature on benzpyrene metabolism and cell multiplication. J. Cell. Physiol. (1971) 77., 385-392. 

Figure 1 Endocytosis of liposomes five different routes into the cell. Multiple pathways can be used by the cell to internalize liposomes. Besides the well-characterized clathrin-mediated endocytosis, other pathways can be applied by the cell. Possible alternative pathways include phagocytosis or macropinocytosis—two pathways that internalize by an actin-driven protuberance of the plasma membrane. Other routes include the involvement of caveolae where substances are taken up into the cell bypass the traditional endosome/lysosome system (particles might escape from being degraded in lysosomes). Finally there exists an ill-defined mechanism that is neither mediated by caveolae nor by clathrin. In a single cell type, two or more of these mechanisms can coexist. Source Adapted from Ref 8.

An improvement of the productivity of the NF-based process to 7.1gl h is obtained by running the process semi-continuously [64]. Final lactic acid concentrations in the permeate can reach values between 10 and 60 g 1 . The higher values are at the lower limit of concentrations found in UF- and MF-based processes [60]. Based on these data, a three-step repetitive process has been proposed [64]. The first step is the cell multiplication step during which pH can be controlled, the second step is an acid production step, followed by NF. In this approach a constant pH is assumed during each separate process step. However, other strategies in the acidification stage, which make use of natural acidification by the lactic acid bacteria are also possible. 

Bringmann. G. and Ktihn. G. Comparison of the toxicity thresholds of water pollntants to bacteria, algae and protozoa in the cell multiplication inhibition test. Water Res., 14(3) 231-241. 1980. 

ISO/DIS 10712. Water Quality — Pseudomonas putida growth inhibition test (Pseudomonas Cell Multiplication Inhibition Test) International Organization for Standardization Geneve, 1995 14 pp. 

Cell multiplication is inhibited because DNA synthesis is insufficient. This occurs in deficiencies of vitamin Bu or folic acid (macrocytic hyperchromic anemia). 2. Hemoglobin synthesis is impaired. This situation arises in iron deficiency, since Fe + is a constituent of hemoglobin (microcytic hypochromic anemia). 

Research in the area of antiviral drag synthesis has only recently allowed a significant step to be made in the area of treating diseases caused by herpes simplex virus, and just recently for treating AIDS. These drags act by inhibiting the process of virus cell multiplication. 

Here the cells are in a uniform environment. No adaptation is needed and cell multiplication proceeds at a constant rate determined by the composition of the fluid in the vessel. This is frequently represented by a Monod-type equation... 

The rate of cell multiplication depends in general on the availability of food and on the build up of wastes which interfere with cell multiplication. The simplest reasonable rate forms are shown below. We use these in the following chapters. 

---