Search

Microorganisms can be defined as a small living forms of life, even can't be viewable with the naked eyes. The three types of microorganisms named Bacteria, Yeasts and Molds in which almost always there may be confusion with their functions, but they are just as real and alive as we are. They eat, grow, reproduce and die also. The tumour cells has also ability to reproduce themselves, to grow in numbers and die to reduce their density in some specific region. In this work we try show the growth for both tumour cells and microorganism with the help of mathematical model and also try to compare the numerical results with the help of Python. This model consists of a system of partial differential equations incorporated with different factors like migrating cells, proliferating cells and nutrient which effects the growth most. At last the results shows the variation of different classes of cell densities with respect to growth function and as well as with the total cell density.

Embryonic morphofunctional competence features regulating post-cryopreservation resumption of development are still poorly understood. In this study, we investigated the correlation between embryonic viability and the speed and ability to resume post-cryopreservation development. Thus, in vitro produced blastocysts were vitrified by the Cryotop method using standard protocols. Subsequently, the embryos were warmed, re-cultured, and classified into groups according to their speed and ability to resume post-cryopreservation development: embryos not re-expanded at 12h (NE12); embryos re-expanded at 12h and hatched at 24h (E12H24); embryos re-expanded at 12h and hatched at 48h (E12H48); embryos re-expanded at 12h and not hatched at 48h (E12NH48). Subsequently, the embryos were subjected to monitoring of total cell number and apoptosis. We identified that the blastocoel's ability to re-expand was negatively affected by the significant higher percentage of apoptotic cells observed in the NE12 group than in the other groups. A greater (P 0.05) number of total cells, found in groups E12H24 and E12H48, seems to have a positive influence on the hatching capacity of blastocysts after cryopreservation. In conclusion, the total number of cells and apoptotic index correlated with the speed and ability to resume post-cryopreservation development. Apoptosis was a determinant for embryonic re-expansion, and the total cell number was crucial for blastocyst hatching.

This study aimed at investigating for the first time whether thermosonication (TS), a non-thermal processing technique, could induce the beer-spoilage bacterium, Lactobacillus acetotolerans CGMCC 7.150, into the viable but putatively non-culturable (VPNC) state. After determining culturable, viable and total cell counts, we found that L. acetotolerans in beer could enter the VPNC state by TS at a constant frequency of 24 kHz at 50 °C at three relatively low volumetric powers (0.6, 1.2 and 1.8 W/mL, but not 2.4 W/mL). Furthermore, with the increase of volumetric power, the time required for L. acetotolerans cells to enter the VPNC state shortened. The addition of Tween 80 at a concentration of 0.1% v/v into de Man Rogosa Sharpe agar enabled the VPNC cells to regain culturability with a recovery time of approximately 3 days. However, their recovery capability decreased with the increasing volumetric power. Scanning electron microscopy analysis showed that cells decreased in size and gradually changed morphology from short rods to coccoids upon entering the VPNC state. An insignificant difference in beer-spoilage ability was found between the exponential-phase and VPNC cells. The resistance of these VPNC cells to 0.025 M NaOH and 0.025 M KOH was enhanced compared with the exponential-phase cells.

The present study aimed to examine the effects of adding different concentrations of resveratrol during in vitro culture (IVC) alone and during both in vitro maturation (IVM) and IVC on ovine blastocyst yield and quality. Therefore, this study was conducted in two separate experiments. The first experiment was carried out to test the effect of different concentrations of resveratrol (0, 0.1, 0.25, 0.5, 2.0, and 5.0 μM) in the IVC medium on cleavage, morula, developmental potential of blastocyst, and total cell number (TCN) of the embryos. Addition of 0.25 and 0.5 μM of resveratrol during IVC significantly enhanced morula and blastocyst rates as compared with other groups (P0.05). Also, supplementation of the IVC medium with 0.5 μM of resveratrol had beneficial effects on trophectoderm cells (TE), inner cell mass (ICM), and TCN of blastocysts. In the second experiment, the same concentrations of resveratrol (0, 0.1, 0.25, 0.5, 2.0, and 5.0 μM) were applied during IVM and IVC. Therefore, oocytes were matured in vitro in the presence of different concentrations of resveratrol for 22-24 h. After in vitro fertilization, presumptive zygotes were cultured in media containing 0, 0.1, 0.25, 0.5, 2.0, and 5.0 μM of resveratrol for 8 d. No significant difference was found in the percentage of oocytes developed to MII (0, 0.1, 0.25, 0.5, and 2.0 μM of resveratrol), but the percentage of oocytes developed to MII were significantly lower in 5.0 μM of resveratrol in comparison with other groups. Addition of 0.5 μM of resveratrol to the maturation and culture media significantly increased morula and blastocyst rates compared with other groups (P0.05). However, a too high concentration of resveratrol (5.0 μM) during IVM and IVC decreased cleavage, morula, and blastocyst rates compared with low concentrations (P0.05). Treatment with 0.5/0.5 μM of resveratrol during IVM/IVC significantly improved the TE, ICM, and TCN of blastocysts. In conclusion, sequential treatment with 0.5 μM of resveratrol during IVM and IVC and during IVC alone improved the developmental competence of oocytes, which was reflected in higher blastocyst rates and TCN of blastocysts.

Background We havebeen attempting to use cardiac spheroids to construct three-dimensional contractilestructures for failed hearts. Recent studies have reported that neuralprogenitors (NPs) play significant roles in heart regeneration. However, theeffect of NPs on the cardiac spheroid has not yet been elucidated. Objective This studyaims to demonstrate the influence of NPs on the function of cardiac spheroids. Methods Thespheroids were constructed on a low-attachment-well plate by mixing humaninduced pluripotent stem (hiPS) cell-derived cardiomyocytes and hiPScell-derived NPs (hiPS-NPs). The ratio of hiPS-NPs was set at 0%, 10%, 20%,30%, and 40% of the total cell number of spheroids, which was 2500. The motionwas recorded, and the fractional shortening and the contraction velocity weremeasured. Results Spheroidswere formed within 48 h after mixing the cells, except for the spheroidscontaining 0% hiPS-NPs. Observation at day 7 revealed significant differencesin the fractional shortening (analysis of variance; p = 0.01). The bestfractional shortening was observed with the spheroids containing 30% hiPS-NPs.Neuronal cells were detected morphologically within the spheroids under aconfocal microscope. Conclusion Theaddition of hiPS-NPs influenced the contractile function of the cardiacspheroids. Further studies are warranted to elucidate the underlying mechanism.

We investigated the aspects of S. Typhimurium biofilms and their resistance (thermal and chemical) depending on the different morphotypes at room temperature (rdar; strain 43971 and bdar; strain 19585) and maturation temperature. Strain 19585 biofilm had a relatively low cell mass and polysaccharide content compared to strain 43971 in all cases, and when matured for 9 days at 15 °C, both properties were significantly higher than at 25 and 37 °C maturation. The difference in secretion ability influenced the pattern in which the biofilm increased resistance. The thermal and chemical resistance levels of strain 19585 biofilms increased at 15 °C, and those of strain 43971 biofilms increased at 15 and 25 °C. When the two strains were mixed, the aspect of biofilm formation was similar to that of strain 43971 except that the heat and chemical resistance were higher at 37 °C maturation. Following 9 days of biofilm maturation, we concluded that 15 °C compared with 25 and 37 °C was the optimal condition for rdar and bdar strains in terms of quantity of total cell mass, EPS secretions and resistance against heat and chemical treatments.

Many adult organs grow or shrink to accommodate different physiological demands. Often, as total cell number changes, stem cell number changes proportionally in a phenomenon called ‘stem cell scaling’. The cellular behaviors that give rise to scaling are unknown. Here we study two complementary theoretical models of the adult Drosophila midgut, a stem cell-based organ with known resizing dynamics. First, we derive a differential equations model of midgut resizing and show that the in vivo kinetics of growth can be recapitulated if the rate of fate commitment depends on the tissue’s stem cell proportion. Second, we develop a twodimensional simulation of the midgut and find that proportion-dependent commitment rate and stem cell scaling can arise phenomenologically from the stem cells’ exploration of physical tissue space during its lifetime. Together, these models provide a biophysical understanding of how stem cell scaling is maintained during organ growth and shrinkage.

The main objective of this study was to establish a correlation between total bacterial count (TBC) and exopolysaccharide (EPS) production in a specific Streptococcus thermophilus strain. TBC was determined based on real-time quantitative polymerase chain reaction (qPCR) standard curves of S. thermophilus T9 cultured in reconstituted skim milk. EPS yields were measured following isolation and purification steps using a dextran standard curve. The relationship between TBC of and EPS production by S. thermophilus T9 was analyzed alongside these standard curves. The results showed that EPS yield reached 36.6 ± 0.8 mg L−1 following 6 h of incubation. Over the same period, the streptococcal counts measured by qPCR increased from 4.71 ± 0.15 to 7.52 ± 0.09 log10 TBC mL−1. Overall, EPS biosynthesis has been shown to be a growth-related trait in S. thermophilus T9 (R2 = 0.991). In conclusion, the monitoring of TBC may provide an insight into the mechanism of EPS production and, therefore, its use can be recommended for this purpose and for EPS quantification. To our knowledge, this is the first research that has associated qPCR-based TBC with EPS yield in S. thermophilus.

Aerobic plate counting assays based on the pour-plate technique are frequently used to enumerate microbial products; however, colony swarming and merging at the agar surface can reduce the accuracy of these assays. Some plating methods mitigate this risk through the inclusion of strategies including agar overlays; however, these interventions may be inadequate to mitigate swarming and merging of certain Bacillus colonies. In the present study, we assessed the accuracy of several pour-plate techniques for the enumeration of a mixed-species Bacillus assemblage. Tested modifications included a customized culture medium formulation, agar overlays, decreased incubation times and increased incubation temperature . Methods which produced countable plates were assessed for agreement with a Bacillus-specific plate counting assay and with total cell counts rendered by flow cytometry. While all tested pour-plate methods underestimated Bacillus endospore concentrations relative to flow cytometry and customized spread-plating, our results suggest that increasing incubation temperature and the inclusion of bile salts into culture medium formulations can improve the accuracy of pour-plate techniques when used to enumerate Bacillus assemblages by decreasing the incidence of spreading colonies. As Bacillus endospore preparations become more ubiquitous in the market, familiar enumeration methods such as the pour-plate technique may require methodological modifications to ensure that the cGMP compliance of Bacillus-based microbial products is assessed accurately.

The evolution of a chemotactic system involving a population of cells attracted to self-produced chemicals is described by the Keller–Segel system. In dimension 2, this system demonstrates a balance between the spreading effect of diffusion and the concentration due to self-attraction. As a result, there exists a critical “mass” (i.e. total cell's population) above which the solution of this system collapses in a finite time, while below this critical mass there is global existence in time. In particular, subcritical mass leads under certain additional conditions to the existence of steady states, corresponding to the solution of an elliptic Liouville equation. The existence of this critical mass is related to a functional inequality known as the Moser–Trudinger inequality. An extension of the Keller–Segel model to several cells populations was considered before in the literature. Here we review some of these results and, in particular, consider the case of conflict between two populations, that is, when population one attracts population two, while, at the same time, population two repels population one. This assumption leads to a new functional inequality which generalizes the Moser–Trudinger inequality. As an application of this inequality we derive sufficient conditions for the existence of steady states corresponding to solutions of an elliptic Liouville system.

Hydroxypropyl methylcellulose (H) films incorporated with oregano and bergamot essential oils were characterized and evaluated for their effectiveness suitability as an edible coating for fresh ‘Formosa’ plum. The effects of the oregano essential oil (OEO) and bergamot essential oil (BEO) at different concentrations of 0.5, 1, 1.5, and 2% (w/w) in the HPMC edible films were observed by measuring their physical and mechanical properties, gas permeation, color values, transparency, antimicrobial activities. The effect of HPMC edible coating with OEO and BEO for fresh ‘Formosa’ plum were analyzed using physiochemical properties and sensory parameters. The 2% H-OEO coating was shown to be very effective in reducing the respiration rate, ethylene production, total weight loss, and total cell count, compared to the plums treated with other coatings at 23 ± 2 °C. In addition, the 2% H-OEO coated plum was firmer and showed less surface color change than the control fruit at the end of storage. The results of our study indicated that the 2% H-OEO coating treatment showed good potential to extend the storage quality of harvested plums. Among all of the sample sensory aspects of H-OEO, H-BEO and H, increased respectively.

In this paper, we discuss a two-way multivariate analysis of variance in high-dimensional settings. With a high-dimensional setting, we propose new approximate tests that work well under the following conditions: 1. The error vectors do not necessarily follow a multivariate normal distribution, 2. The cell sizes are unequal, 3. The cell covariance matrices are unequal, and 4. The dimension p is much larger than the total cell size n . The accuracy of the proposed tests with finite samples is shown through simulations for a variety of high-dimensional scenarios.

A thermodynamic method is proposed that can determine to which electrode the entropy evolution is attributable without destroying the lithium battery. The entropy evolution of two battery types sharing the same anode composition but different cathode compositions are monitored over cycling. Then, the entropy evolution of the two types are cross-correlated to identify their common component. From the correlation coefficient, the electrode that dominates the entropy evolution at each SOC could be identified. Indicating that the material evolution of each electrode in a battery could be monitored separately by the thermodynamic analysis. Moreover, in combination with prior nondestructive tools, the identification of each electrode’s contribution to the total cell entropy opens the possibility to nondestructively monitor the degradation processes of each electrode continuously during the battery cycling.

Purpose A growing body of evidence suggests that quantification of total cell-free DNA (TcfDNA) may serve as an appropriate biomarker for risk for in several clinical scenarios. We designed a multi-center prospective blinded study to investigate the value of TcfDNA in non-invasive clinical monitoring following heart transplantation, DTRT. Methods 241 heart transplant patients, age at transplant 8 days to 73 years (146 18 years), were recruited from seven heart transplant sites producing 2537 samples. 134 patients were enrolled prior to transplant and 107 were enrolled within 30 months following transplant. All patients were followed longitudinally for at least one year. 2537 samples were analyzed to determine the TcfDNA (myTAI-Total cfDNA, TAI Diagnostics, Wauwatosa, WI). All downstream sample processing was handled by researchers blinded to clinical parameters. Logistic regression for modeling and the standard receiver operating characteristic (ROC) curve was calculated, and repeated measures analysis using generalized linear modeling with patients as clusters was used. Results By ROC analysis a threshold of TcfDNA ng/ml plasma could be determined (33.6 ng/ml) that was highly predictive of death within 30 days, p Conclusion Elevation of TcfDNA strongly correlates with risk for near term death in both adult and pediatric heart transplant recipients and precise measurement of TcfDNA may be useful as a trend monitor for effectiveness of clinical care.

Introduction Both total nucleated cell (TNC) & CD34+ cell doses are critical for CB engraftment. However, how CBU potency characteristics are reported is not established. Methods We evaluated the completeness of CBU potency information in NMDP Traxis system & individual Bank Reports at the time of selection/ release. We then compared the reported data to CBU post-thaw values. At our center, CBU underwent albumin-dextran dilution (1:8). Post-thaw flow cytometry for CD45+/CD34+ cell counts & 7-AAD viability was done within 2 hours. Results Between 1/2016-4/2018, 154 CBU were obtained from domestic (N=88) or international (N=66) Banks. Post-processing/ pre-cryopreservation results: At least 1 viability result was reported for 147/154 (95%) CBU (Table 1). CD34+ viability was present in only 75/154 (49%) Reports. In most, the method was not stated (presumed 7-AAD). "Total cell viability" (not specifying CD45+ or TNC) was present in 110/154 (71%); 26 of these were by trypan blue or ethidium bromide. Total CFU were reported in 96/154 (62%), mostly domestic CBU & 7 reported only CFU-GM. Of 7/154 (5%) CBU without any viability, 2 were domestic (collected 2006, 2012) & 5 international (collected 2012-2015). Only 6 domestic CBU did not have CFU data (5 collected in 2006). Post-thaw segment results: A minority of Reports (47/154, 31%), all international, included segment CD34+ data. 43/154 (28%) also had segment CFU results but few included pre-cryopreservation values for comparison. Five CBU Reports had only cryovial data. Results after CBU thaw: Median CD34+ viability was 93% (SD: 7%). Except one very low CD34+ viability (22%, no pre-freeze value reported), all others were >77%. Post-thaw CD34+ viability was similar between domestic (mean: 92%; SD: 8.1%) & international CBU (mean: 92%; SD: 3.6%). However, viable CD34+ cell recovery (ratio of viable CD34+ cells post-thaw to those pre-freeze) was significantly lower for international CBU (p 84% & 28/43 (65%) had higher post-thaw CBU CD34+ viability than the segment (median increase: 10%). Conclusions CBU Reports include highly variable potency data & may be incomplete even when the information is available at the Banks. Efforts to standardize CBU potency testing & reporting are needed. Disparities in CD34+ recovery likely indicate high inter-laboratory variability & possibly differences in flow gating strategies. Also, Banks need to provide interpretation of segment results as reduced viability may be due to technical challenges, not CBU quality problems. Finally, the clinical significance of this data requires validation.

Many species live in spatially separated patches. In real ecosystems, the capacity of patch is finite. If a patch is already occupied by the individuals of some species, then the migration into the patch is impossible. For the migration, empty cells are necessary in the destination patch (“nonlinear migration”). In the present article, we deal with two-patch system composed of prey and ambush predator. Preys can migrate between both patches, but predators stay in a single patch. Agent-based model (ABM) is applied in respective patches. Each patch contains a finite number of cells; “capacity” of a patch is defined by the total cell number in the patch. Each cell is either empty or occupied with prey or predator. Reaction-migration equations are presented for non-spatial system of ABM. Both non-spatial and spatial models indicate that the population dynamics are largely affected by the finiteness of respective patches. In particular, we find a self-organized habitat segregation, depending on parameter values. The prey density becomes nearly zero in the predator patch, although many preys live in non-predator patch. Although the migration occurs between both patches, the prey almost disappears in one patch. Such a segregation may be caused by the finite capacity of patches.

A new presence/absence method has been developed to count fluorochrome-stained bacterial and archaeal cells on membrane filters using epifluorescence microscopy. This approach was derived from the random distribution of cells on membranes that allowed the use of the Poisson distribution to estimate total cell densities. Comparison with the standard Acridine Orange Direct Count (AODC) technique shows no significant difference in the estimation of total cell populations, or any reduction in the precision of these estimations. The new method offers advantages over the standard AODC in considerably faster counting, as there is no need to discriminate between every potential cell visible on a field and fluorescent detritus, it is only necessary to confirm the presence of one cell. Additionally, the new method requires less skill, so has less reliance on expert counters, and that should reduce inter-counter variability. Although this work used the fluorochrome Acridine Orange, clearly the results are applicable to any fluorochrome used to count bacterial and archaeal cells. This method was developed using enrichment cultures for use with enrichment cultures and aqueous environmental samples where interfering detrital and mineral particles are minimal e.g., freshwater/seawater, therefore, it is not suitable for estimating total cells from sediment samples. This method has the potential for use in any situation where counts of randomly distributed items are made using a grid or quadrat system.

Hydrogenated microcrystalline silicon germanium (µc-Si 1– x Ge x :H), with the advantage of its narrower variable band gap and higher absorption coefficient over the conventional hydrogenated microcrystalline silicon (µc-Si:H), has been implemented as the bottom sub-cell absorber of the triple junction solar cells. By replacing µc-Si:H i-layer with µc-Si 0.91 Ge 0.09 :H i-layer in the triple junction solar cell, the bottom sub-cell thickness ( D bottom ) could be reduced by almost a half, meanwhile a higher efficiency was attained. As a result, an initial efficiency of 12.02% in an a-Si:H/a-Si 0.6 Ge 0.4 :H/µc-Si 0.91 Ge 0.09 :H triple junction structure with a total cell thickness as small as 1800 nm was achieved. It is demonstrated that the triple junction solar cell incorporating µc-Si 1− x Ge x :H bottom sub-cell with high efficiency and a relatively low thickness has a high potential for cost-effective photovoltaic applications.

In this study, we have investigated the electrical and structural properties of sub-micron thick Cu(In,Ga)Se2 (CIGS) films with various in-situ post annealing times. Sub-micron thick CIGS films were deposited on Mo/soda-lime glass (SLG) substrates by single-stage co-evaporation. We decreased the deposition time to 700 s for sub-micron thick CIGS films (≈0.85 μm thickness). After deposition, the CIGS films were annealed under a constant Se rate by a SiC heater for 500–3000 s in a co-evaporator. Increased annealing time led to improved surface morphology and grain size. In the XRD patterns, the CIGS films also showed improved crystal quality for the (112) plane. We suggest that post annealing of sub-micron thick CIGS films at optimized time can be applied for improving device efficiency. The open circuit voltage (Voc) and the fill factor (FF) were increased by 15% and 10%, respectively. The total cell efficiency was increased by more than 35%.

This paper reports studies on the effects of re-vitrification by the CPS (Closed Pulled Straw) method on the development of 4-cell stage mouse embryos. The procedure involved culturing 2-cell mouse embryos in G-1 medium until the 4-cell stage followed by the division of the normal 4-cell stage embryos into a control group (non-vitrified) and two experimental subgroups (vitrified and re-vitrified). Embryos in the vitrified subgroup were cryopreserved by the CPS vitrification method. In the second experimental subgroup (re-vitrified), embryos that were already vitrified were warmed and cryopreserved again by the same method. There was no significant reduction in the rate of blastocyst formation after vitrification and re-vitrification. However, re-vitrification reduced the total cell number, ICM (inner cell mass) percent and blastocyst diameter (P < 0.05). These results showed that vitrification and re-vitrification by the CPS method did not negatively affect the development of vitrified-warmed 4-cell mouse embryos, whereas re-vitrification significantly reduced both the cell number and diameter of blastocysts.

The objective of this study was to determine the effect of storage temperature during ovary transport on the developmental competence of bovine oocytes for use in somatic cell nuclear transfer (SCNT). Ovaries obtained from a slaughterhouse were stored in physiological saline for 3-4h at one of the three temperatures: 15 °C, 25 °C, or 35 °C. The developmental competence of oocytes used for SCNT was ascertained by cleavage and blastocyst formation rate, total cell number, apoptosis index, and the relative abundance of Bax and Hsp70.1 in day 7 blastocysts. Ovaries stored at 35 °C for 3-4h reduced the recovery rate of grade I and II oocytes compared with those stored at 25 °C or 15 °C (45.1±0.7% vs. 76.7±1.2% or 74.8±2.0%, P

In this short work, by combining the total cell evolution curve and the two-compartment model, the evolution of one of the subpopulations is simulated while the system interacts with a proliferating regulatory factor.

Objective To study the effects and the appropriate concentration of insulin on the development of mouse embryos in vitro, and the effects of insulin on the development of different stages of embryos. Methods Mouse embryos were cultured in vitro in the mKSOM media supplemented with insulin at different concentrations and with insulin during different stages of embryos. The blastocyst rates and the cell numbers were counted. Results Additions of insulin significantly increased the rates of blastocyst and the total cell numbers. The concentrations of 0.005 µg/ml and 0.05 µg/ml insulin caused a significant increase in the total cell numbers compared with the control and experimental groups. Addition of insulin from 2-cell to 4-cell stage or from the 4-cell to morula stage, significantly increased the blastocyst rates compared with control and experimental groups. Conclusion Insulin can promote the development of mouse embryos in vitro. The appropriate concentration of insulin added in mKSOM was 0.005 µg/ml and 0.05 µg/ml. Exposure of embryos to insulin, beginning at the 2-cell and extending to the 4-cell stage or beginning at the 4-cell and extending to the morula stage, is important for the development of ICR mouse embryos in vitro.

Although cellular proliferation is a key component in the progression of atherosclerosis, research so far has been focused primarily on VSMCs. In this study we attempted to evaluate overall proliferation rates in general, as well as foam cells and the endothelial cells lining newly formed plaque microvessels in particular. For this purpose, cellular proliferation was assessed through immunohistochemical staining for PCNA in 10 fresh human carotid artery samples received from patients undergoing carotid endarterectomy. Overall proliferative activity was found significantly higher ( P ≤ 0.01) among complicated type VI lesions compared to uncomplicated type V lesions. A similar assessment focused on foam cells alone also revealed a significantly higher ( P ≤ 0.05) proliferative index among complicated lesions. On the other hand, the proliferation rate for the endothelial cells lining the interior walls of newly formed microvessels was harder to properly assess, since only two of the uncomplicated lesions bore signs of neovascularization. Still, both of these samples displayed proliferation rates similar to those of the complicated type VI lesions. Thus, it seems that, although total cell population and foam cells are probably affected by the stimulating factors that are expressed during acute events, the same does not apply to the endothelial cells lining plaque vessels.

Teicoplanin, a glycopeptide antibiotic, is composed of five main components, denoted T-A2-1 to T-A2-5. We investigated the use of glycerol as a carbon source affecting the teicoplanin components and its acyl moieties. As a result, we show the change of teicoplanin components, as well as an increase of total teicoplanin yields, caused by the addition of glycerol to the production medium. Analysis of the total cell lipids upon the addition of glycerol also showed a corresponding change in the proportion of teicoplanin, suggesting that glycerol strongly affects a change of teicoplanin branched acyl moieties.

By combining the total cell evolution curve and a two-compartment model interacting with dynamic anti-cancer agents, the evolution of subpopulations has been analytically obtained and investigated in this work.

A motility mechanism based on a simple exclusion process, where the movement of discrete agents on a lattice is either unbiased (symmetric) or biased (asymmetric) is considered. Estimates of diffusivities from tracking data do not describe the population-level response of the system. This mismatch between the individual-level and population-level behaviour can be resolved by averaging the individual-level mechanism in terms of an expected site occupancy. New insight into simple exclusion processes is obtained by representing the system as a series of interacting subpopulations. This formalism leads to a system of nonlinear advection–diffusion equations which can be interpreted in terms of the agent fluxes. These interactions have consequences for both agent-based modelling and continuum modelling in cell biology, such as tracking subpopulations of cells within a total cell population.

Imaging, light microscopy and scanning electron microscopy were used to compare the microstructure of crumbs from pound cakes baked in a microwave or conventional oven. The microwave baking conditions for pound cake (240 W, 5 min) were established in previous research, conventional baked pound cakes were obtained using a swing oven at 180 °C for 40 min. Statistical differences in total cell, cell/cm2 and mean cell area (P⩽0.05) were observed in the image analysis. Cells from microwaved pound cake crumbs were 20% larger. However, factor shape was 0.81 for both microwave and conventionally baked crumbs, and crumbs from both oven types were similar in appearance. Light microscopy revealed birefringence in crumbs from both types of pound cakes. Scanning electron microscopy revealed that the conventionally baked product had a greater amount of protein matrix however; the matrix structure of the crumb was comparable between microwave-baked and conventionally baked pound cakes. In conclusion, our results suggest that the unique aspects of pound cake dough, including its high content of fat, sugar and moisture, make it well suited to microwave baking.

We analyse the coalescence of invasive cell populations by studying both the temporal and steady behaviour of a system of coupled reaction–diffusion equations. This problem is relevant to recent experimental observations of the dynamics of opposingly directed invasion waves of cells. Two cell types, u and v , are considered with the cell motility governed by linear or nonlinear diffusion. The cells proliferate logistically so that the long-term total cell density, u + v approaches a carrying capacity. The steady-state solutions for u and v are denoted u s and v s . The steady solutions are spatially invariant and satisfy u s + v s = 1 . However, this expression is underdetermined so the relative proportion of each cell type u s and v s cannot be determined a priori. Various properties of this model are studied, such as how the relative proportion of u s and v s depends on the relative motility and relative proliferation rates. The model is analysed using a combination of numerical simulations and a comparison principle. This investigation unearths some novel outcomes regarding the role of overcrowding and cell death in this type of cell migration assay. These observations have relevance to experimental design and interpretation regarding the identification and parameterisation of mechanisms involved in cell invasion.

The xylanolytic enzyme system was examined in Bifidobacterium adolescentis , B. infantis and B. bifidum to determine their ability to utilize xylooligosaccharides (XOSs). All these species produced only xylosidase and arabinosidase, and no xylanase, α-glucuronidase and acetyl xylan esterase were found. The optimal activity of β- d -xylosidase from B. adolescentis was at pH 5.6 and 45 °C, and α- l -arabinoside was at pH 5.0 and 40 °C. The degradation products of cell-free extracts and the growth rate of B. adolescentis were tested over XOSs and XOSs de-branched by recombinant α-glucuronidase. The results showed that de-branching α-glucuronidase increased the production of xylose and the total cell density by 10%, and accelerated the growth of B. adolescentis by 20%.

This study examined calcium, iron, and zinc uptake in Caco-2 cells (retention plus transport) from white beans, chickpeas, and lentils subjected to prior in vitro gastrointestinal digestion and the effect of cooking (traditional and industrial—ready to eat) on the uptake of these minerals from lentils. The highest cell uptake of calcium, iron, and zinc corresponded to raw chickpeas, which had the lowest soluble oxalate content and intermediate phenolic and tannin contents. From these results, raw chickpeas would be the best dietary source of calcium, iron, and zinc, although consumption in this form (ie, raw) is low. Cooking affects the calcium, iron, and zinc contents of lentils and their solubility and also the contents of components that can affect mineral solubility; however, these changes exerted only favorable effects on total cell uptake of calcium from ready to eat lentils, with negative effects in the case of iron and zinc.

The power function of metabolic rate scaling for an organ is established as B organ ∼ T organ ( D + N / 6 ) / ( D + 1 ) , where Borgan is the metabolic rate of the organ, Torgan is its mass, D is its fractal dimension of the total cell boundary, and N is its cell’s degree of freedom of motion. This prediction agrees quite well with the experimental data for the brain, liver, heart, and kidneys, and it explains very well the reason why the maximal metabolic rate induced by exercise scales with M0.86 rather then M0.75.

In order to detail the relation between the initial positioning of statoliths and root graviresponsiveness, the movement of amyloplasts within root statocytes of cress ( Lepidium sativum L.) seedlings grown under fast clino-rotation (50 rpm) and vertically at 1 g or 180° inverted after growth at 1 g has been analyzed during a subsequent 6-min period of lateral (reoriented 90°) gravistimulation. The main parameters of statolith motion kinetics such as relative positions and motion velocities in transverse and longitudinal directions have been evaluated taking linear measurements of organelle position with respect to the lower longitudinal and distal wall in the cells of the 2nd–5th columella storeys. A significant discrepancy in the direction and velocity of statolith movement has been determined within the first and second minutes of root horizontal placement. Centrally or proximally located statoliths in clino-rotated or inverted root statocytes moved transversely to the lower longitudinal cell wall more quickly as compared with distally located ones in 1- g root cells. At the same time, the longitudinal displacement of proximally located statoliths towards the cell center has been determined, while this displacement of distally located plastids was significantly more pronounced. The longitudinal motion of amyloplasts grouped in the central cell part was negligible within this 2-min period. After the 6th minute of stimulation, the total downward shift of the mean relative position of statoliths amounted to 16.3% from the total cell width in clino-rotated root statocytes and 17.1% in the cells of inverted roots, while it equalled 13.3% in 1- g root statocytes. The total change of the relative longitudinal position of amyloplasts with respect to the distal cell wall remained almost unchanged in roots grown on the clinostat. In inverted roots, the initial longitudinal position of 56.2% from the total cell length has been shifted significantly to 47.8% and from 27.7% to 38.8% in 1- g roots. The data imply that a more pronounced sedimentation of centrally or proximally located amyloplasts during the first minutes of root stimulation could be responsible for the earlier generation and transmission of a directional signal which triggers the subsequent events of gravitropic reaction in clino-rotated or inverted roots as compared to 1- g roots.

Role of Ca2+ was studied for neurite outgrowth in rat pheochromocytoma cell, PC12 and its subline, PC12D differentiated into neuron-like cells. The cells were cultured during 1–3 days in the presence of 10 μM forskolin together with 0–0.58 mM EGTA, that is, at 0.70–0.17 mM of Ca2+ measured in medium. We obtained the fraction of neurite-bearing cells f=n+/nT under microscope, where n+ is the number of cells with at least one neurite longer than the cell body diameter against the total cell number nT. f varied concavely in PC12D and convexly in PC12 at different culture days as quadratic functions of Ca2+ molarity. In 1 day, PC12D increased f more than PC12 at 0 mM EGTA (0.70 mM Ca2+) and the difference was not observed at 0.45–0.30 mM Ca2+. In 2 days f was decreased in PC12D and increased in PC12 as compared with those in 1 day. In 3 days PC12D less increased f than PC12 at 0.45–0.17 mM Ca2+. In proliferation the number of both the cells markedly decreased in Ca2+-free medium at 1 mM EGTA. The results exhibited that the decrease of Ca2+ induces and reduces the neurite outgrowth in PC12 and PC12D, respectively. There may exist some switching mechanisms operating oppositely in original PC12 and differentiated PC12D.

Marine microorganism activities are commonly assessed by bulk methods and assigned to the total cell count. The presence in significant amounts of ghost, dead, and damaged cells makes such as assignment a non-correct one. A Nucleic Acid Double Staining protocol (NADS) of fresh water bacteria (Barbesti et al., Cytometry 40 (2000) 214-218) has been adapted to resolve viable, damaged and dead cells in marine environments (Gregori et al., Appl. Environ. Microbiol. 67 (2001) 4662-4670). The present reports the first in situ application of this approach, conducted in the Bay of Marseilles in winter and spring periods at two sites with contrasted features.

Fibroblasts cultured from the distal lower extremity of chronic venous insufficiency (CVI) patients exhibit characteristics of cellular senescence. Basic fibroblast growth factor (bFGF) has been shown to improve growth rates in these fibroblasts. In bFGF-treated fibroblasts, levels of fibronectin and matrix metaloproteinase-2 (MMP-2), known to be up-regulated in senescence, were examined to determine whether bFGF induces changes in these markers of senescence with rescue of cellular proliferation. Fibroblasts were isolated from the distal leg of patients with CVI with and without ulcers (fb-D). In all patients, a control was obtained from the proximal ipsilateral thigh (fb-P). Cells were plated at 3000 cells/plate and treated with bFGF (20 ng/mL) on days 1, 5, 8, and 11. Total cell number was obtained on days 5 and 12 using the Coulter particle counter, and concurrently cells were plated at 10,000 cells/plate and treated with bFGF on the same schedule; cell lysate was harvested on day 12 for immunoblot analysis for MMP-2 and fibronectin. In all patients (n = 7), fb-P grew faster than fb-D (p = 0.039). fb-D showed a mean 3.3-fold increase in growth in response to bFGF, and immunoblot analysis demonstrated an up-regulation of fibronectin and MMP-2 in response to bFGF. This represents the possibility that by stimulating growth, bFGF may drive cells toward senescence. This suggests clinical implication for the use of bFGF and other growth factors in general.

Outgrowth of neurites in culture is used for assessing neurotrophic activity. Neurite measurements have been performed very slowly using manual methods or more efficiently with interactive image analysis systems. In contrast, medium-throughput and noninteractive image analysis of neurite screens has not been well described. The authors report the performance of an automated image acquisition and analysis system (IN Cell Analyzer 1000) in the neurite assay. Neuro-2a (N2a) cells were plated in 96-well plates and were exposed to 6 conditions of retinoic acid. Immunofluorescence labeling of the cytoskeleton was used to detect neurites and cell bodies. Acquisition of the images was automatic. The image set was then analyzed by both manual tracing and automated algorithms. On 5 relevant parameters (number of neurites, neurite length, total cell area, number of cells, neurite length per cell), the authors did not observe a difference between the automated analysis and the manual analysis done by tracing. These data suggest that the automated system addresses the same biology as human scorers and with the same measurement precision for treatment effects. However, throughput of the automated system is orders of magnitude higher than with manual methods.

Aim: Culture remains important for the detection and typing of Clostridium difficile. Culture of C. difficile spores can be enhanced on media supplemented with a germinant. Despite this, unsupplemented media continues to be used in some laboratories. The aim of this study was to quantify the effect of the known germinant sodium taurocholate on recovery of C. difficile spores and to determine if the supplement impacts on the recovery of vegetative C. difficile. Methods: The recovery on cycloserine-cefoxitin-fructose agar (CCFA) with and without taurocholate, of spore, vegetative, and total cell fractions of broth cultures of eight C. difficile isolates was compared. Results: Taurocholate in CCFA did not inhibit growth of vegetative C. difficile and significantly increased recovery of spores (p=0.04). Conclusions: The routine incorporation of taurocholate in CCFA is recommended for improved sensitivity in C. difficile culture from specimens.

We have developed Escherichia coli and Pseudomonas expression vectors based on the alkane-responsive Pseudomonas putida ( oleovorans ) GPo1 promoter P alkB . The expression vectors were tested in several E. coli strains, P. putida GPo12 and P. fluorescens KOB2Δ1 with catechol-2,3-dioxygenase (XylE). Induction factors ranged between 100 and 2700 for pKKPalk in E. coli and pCom8 in Pseudomonas strains, but were clearly lower for pCom8, pCom9, and pCom10 in E. coli . XylE expression levels of more than 10% of total cell protein were obtained for E. coli as well as for Pseudomonas strains.

Some recent work in the development of a high energy density lead–acid battery for electric vehicle application is described. Two separate methods are used to achieve this objective. Significant total cell weight savings can be achieved by the use of an electrolyte management system. This minimises the quantity of water used in the electrolyte. The second feature concerns the form and utilization of the lead–paste active materials. The positive and negative pastes are carried as a slurry and are agitated during the charge/discharge cycle. This maximises the utilisation of the active materials and reduces premature sulphation.

In an in vitro model of granulation tissue, early passage human diploid fibroblasts under mechanical tension showed little or no apoptosis. Release of mechanical tension triggered an apoptotic response that occurred within 3-6 h and reached a plateau by 24 h. The percentage of apoptotic cells (approximately 15%) remained constant up to 7 days, and after 3 days, total cell number declined. Identification of mechanical unloading as a stimulus for apoptosis, without application of pharmacologic or genetic intervention, is a novel observation that permits us to model similar events that occur during wound healing. Studies on the mechanism regulating apoptosis under these conditions established that the apoptotic response does not require differentiation of cells into myofibroblasts but is governed by a combination of mechanical tension and growth factors in the collagen matrix.

Total cell numbers within a confined tissue volume, or fractions of cell numbers may be relevant in toxicopathology. They can be estimated with the disector, or the formula of Ebbeson and Tang. For the latter the thicknesses of the sections should be estimated, e.g. with confocal microscopy, or with a vertically embedded section. The use of these methods, in combination with Cavalieri's principle, will avoid the inconsistencies possibly associated with differences in the level of sectioning. Biochemical tests on intracellular specific molecules may be applied on homogenized tissue. If the tissue is composed of different cell types reacting differently to the tested substance, it may be necessary to estimate the fractions of different types of cells in the tissue concerned. Because of cell size differences, single sections do not give truthful results. The problem is solved by applying the formula of Ebbeson and Tang.

Total cell numbers, abundance of respiring bacteria and [3H]thymidine and [14C]leucine incorporation rates were investigated in four groundwater wells of low nutrient content. Total cell numbers in the pumped groundwater were low (14 × 103 to 279 × 103 cells mL−1), and [3Hthymidine and [14C]leucine incorporation rates were, with one exception, below the detection limit. Therefore we exposed sediments in situ for 2 months which allowed us to determine bacterial numbers and incorporation rates of labeled substrates by bacteria attached to sediment particles. The two habitats differed considerably in all bacterial parameters both in magnitude and seasonal trends. Total bacterial numbers of sandy sediments (52.1 ± 21.3 × 106 cells cm−3) corresponded in average to 663 cm3 of pumped groundwater (78.5 ± 61.5 × 106 cells L−1). For the fraction of respiring bacteria this ratio was on average 3032 cm3 (sediments: 10.3 ± 5.4 × 106 respiring cells cm−3; groundwater: 3.39 ± 6.01 × 106 respiring cells L−1). The percentage of respiring bacteria in sandy sediments was between 6.0 and 41.4% (average 19.8) compared to 1.0 to 24.9% (average 5.23) in the pumped groundwater. Our results stress the importance of studying the microbial communities attached to sediment, as pumped groundwater samples may not be representative for the real structure and dynamics of microbial assemblages in subsurface environments.

Six dithymidine phosphotriester analogs bearing an enzymolabine phosphate protecting group were synthesized in order to select the most appropriate model for the prooligonucleotide approach. Series 1 and 3 were chosen on the basis of their stability in culture medium and their capacity, when incubated in total cell extract, to deliver selectively dithymidine phosphodiester and phosphorothioate diester respectively.

For the first time, metabolically active bacterial cells have recently been quantified in deep marine sediments. In contrast to previous total cell counts that do not differentiate between active cells and inactive or dormant cells, these quantifications using oligonucleotide hybridization probes target active cells and their ribosomal (r)RNA. They demonstrate a sizable, active bacterial subsurface biosphere, and allow realistic estimates of cell-specific respiration rates and turnover times for living bacteria in this global extreme habitat. In situ activities and physiologies of these active subsurface microbiota emerge as high-priority research areas.

Histamine release from canine leucocyte-enriched peripheral blood preparations was measured in atopic, non-atopic and artificially sensitised dogs after immunological challenge with D. farinae antigen and anti-IgE. Total cell histamine and spontaneous histamine release was also measured. The total cell histamine content of equal leucocyte preparations was not statistically significant between the atopic and non-atopic groups. At all dilutions of antigen a higher amount of histamine was released from the leucocytes of atopic dogs than was seen in the non-atopic group. No histamine release in response to D. farinae was seen in the sensitised dogs although a statistically significant increase in serum D. farinae-specific IgE could be demonstrated after sensitisation (P < 0.03). Histamine release in response to anti-IgE was significantly greater in the atopic dogs than the non-atopic dogs (P < 0.004) and the sensitised dogs (P < 0.003). There was no statistically significant difference in total serum IgE between the groups. The authors conclude that the leucocytes of atopic dogs have a greater tendency to release histamine than those of normal and artificially sensitised dogs and that this is independent of the concentration of total serum IgE or antigen-specific IgE. They suggest that there may be immunoregulatory abnormalities in atopic dogs intrinsic to the atopic state as is described in man.

Growth of recombinant luminous E.coli immobilized in alginate beads revealed a novel observation: pellets with a low initial cell density may yield higher final density than those of high initial density. Observations of growth were combined with bioluminescence measurements that reflect the product of oxygen concentration and cell density distribution in a spherical gel pellet. To account for this behavior a model for growth of immobilized cells in the form of microcolonies was constructed and the behavior was simulated in a deterministic and stochastic (cellular automata) forms. Growth in the form of microcolonies was observed in this study as well as in other studies. Analytical and approximate solutions for zero or first-order kinetics predict that the final total cell density and the final thickness of active biomass layer vary with the initial cell density as a — 16 power. This exponent describes well the experimental results. Stochastic simulations revealed similar qualitative dependence. A pseudohomogeneous model of growth cannot account for this behavior.