Average Doubling Time Research Articles

TMOD-10. ESTABLISHMENT OF ADULT AND PEDIATRIC BRAZILIAN PRE-CLINICAL MODELS FOR HIGH-GRADE GLIOMAS

Abstract High-grade gliomas (HGG) are the most aggressive brain tumors, necessitating robust and representative preclinical models for therapeutic research. We established primary cultures and patient-derived xenograft models from three pediatric high-grade gliomas (pHGG) and one adult IDH wild-type glioblastoma (GBM IDHwt) Brazilian patients. The first pHGG case, from an 11-year-old with PDGFRA (c.1977C>G) and TP53 (c.637C>T) mutations, led to the development of the HCB570 primary culture, PDX and patient-derived orthotopic xenograft (PDOX) OXP9. The second pHGG, from an 11-year-old with CMMRD syndrome and MSH6 germline mutation, resulted in the HCB589 primary culture, PDX and PDOX OXP22. The third pHGG case, from a 14-year-old with diffuse midline glioma harboring an H3F3A mutation, established the HCB604 primary culture and PDX OXP32. The HCB612 primary culture and PDX GBM1, were established from an adult patient with GBM IDHwt, TERT mutated, with no MGMT promoter methylated. The primary cultures showed varied proliferative rates, with an average doubling time of 55 hours. All cultures demonstrated colony-formating capability, with an average IC50 of 750µM for temozolomide (TMZ) exposure. Immunohistochemical and EPIC methylation profiles confirmed that the PDX models closely resemble the patient features. Our establishment of diverse preclinical models, including those derived from patients with rare genetic conditions such as CMMRD, provides valuable insights into HGG pathogenesis and potential therapeutic strategies. The present Brazilian patient-derived models enrich glioma research inclusion diversity and foster future personalized treatment approaches.

Comparative Analysis of Heavy Metal Content in Impacted Third Molars from Industrial and Non-Industrial Areas and Its Effect on the Isolation, Culture, and Proliferation of Dental Stem Cells (DSCs).

Background: This study investigates the impact of environmental pollution on the quality and viability of dental stem cells (DSCs) from impacted third molars. By comparing DSCs from patients in industrial areas with high air pollution and those from non-industrial regions, the research assesses the adverse effects of heavy metals on stem cell proliferation. Methods: Impacted lower third molars were collected from 28 patients-10 from industrial and 18 from non-industrial areas. Patients were divided into two age groups: 18-27 years and 28-38 years old. Dental pulp was extracted under sterile conditions, and DSCs were isolated and cultured. Heavy metal concentrations in dental tissues were measured using atomic absorption/emission spectrometry. Results: The study found significantly higher concentrations of copper and lead in the dental tissues of patients in industrial areas. Cell viability was lower in samples from these areas, with a statistically significant difference in average doubling time and the number of cells obtained after the first passage. There was no significant impact of gender on heavy metal content, except for higher iron levels in men. Conclusions: Exposure to industrial pollutants negatively affects the viability and proliferation of DSCs, but there are no differences in differentiation in the osteogenic medium regarding cell mineralization. These studies highlight the importance of environmental factors for oral health, suggesting that residents of polluted areas may face greater difficulties in dental and regenerative treatments. Further research is needed to develop strategies to mitigate the effects and improve clinical outcomes for affected populations.

Modeling the growth of Salmonella in raw ground pork under dynamic conditions of temperature abuse

Salmonella contamination of pork products is a significant public health concern. Temperature abuse scenarios, such as inadequate refrigeration or prolonged exposure to room temperature, can enhance Salmonella proliferation. This study aimed to develop and validate models for Salmonella growth considering competition with background microbiota in raw ground pork, under isothermal and dynamic conditions of temperature abuse between 10 and 40 °C. The maximum specific growth rate (μmax) and maximum population density (MPD) were estimated to quantitatively describe the growth behavior of Salmonella. To reflect more realistic microbial interactions in Salmonella-contaminated product, our model considered competition with the background microbiota, measured as mesophilic aerobic plate counts (APC). Notably, the μmax of Salmonella in low-fat samples (∼5 %) was significantly higher (p < 0.05) than that in high-fat samples (∼25 %) at 10, 20, and 30 °C. The average doubling time of Salmonella was 26, 4, 2, 1.5, 0.8, and 1.1 h at 10, 15, 20, 25, 30, and 40 °C, respectively. The initial concentration of Salmonella minimally impacted its growth in ground pork at any temperature. The MPD of APC consistently exceeded that of Salmonella, indicating the growth of APC without competition from Salmonella. The competition model exhibited excellent fit with the experimental data, as 95 % (627/660) of residual errors fell within the desired acceptable prediction zone (pAPZ >0.70). The theoretical minimum and optimum growth temperatures for Salmonella ranged from 5 to 6 °C and 35 to 36 °C, respectively. The dynamic model displayed strong predictive performance, with 90 % (57/63) of residual errors falling within the APZ. Dynamic models could be valuable tools for validating and refining simpler static or isothermal models, ultimately improving their predictive capabilities to enhance food safety.

Impact of age and donor sites on bioactivities of tendon cells in autologous tenocyte implantation (OrthoATI™) for treatment of chronic tendinopathy

ObjectivesAutologous tenocyte implantation (OrthoATI™) therapy has demonstrated efficacy in treating patients with tendinopathy at various anatomical sites. This study evaluates the effect of patient age, gender, and tendon biopsy site on morphology, growth, and gene expression of autologous tendon cells used to treat chronic tendinopathy. MethodsPatients undergoing OrthoATI™ for tendinopathies between 2020 and 2022 were initially treated by biopsies taken from patella tendon (PT) or palmaris longus tendon (PL). The biopsies were sent to a Good Manufacturing Practice (GMP) cell laboratory where tendon cells were isolated, cultured, and expanded for four to six weeks. Cell morphology was assessed using phase contrast microscopy. Droplet digital PCR (ddPCR) was utilized for gene expression analysis. Dichotomous results were compared between groups using x2 or Fisher's exact tests with no adjustment for multiple comparisons. The nonparametric Mann–Whitney U and Kruskal–Wallis tests were utilized for the sex and age (<35y, 35-44y, 45-54y, >55y) analyses, respectively. All analyses were performed using IBM SPSS v27, and a two-tailed P-value of <0.05 was considered statistically significant. Results149 patients were included in the analysis. The PT was biopsied in 63 patients, and PL in 86 patients. There were no observer effects for age and gender between the PT and PL groups. There was no statistical significance between the PT and PL tendons for cell morphology, average cell population doubling time (PDT) (PT 83.9 vs PL 82.7 ​h, p ​= ​0.482), cellular yield (PT 16.2 vs PL 15.2 ​× ​106, p ​= ​0.099), and cell viability (PT 98.7 vs PL 99.0%, p ​= ​0.277). Additionally, ddPCR analyses showed no statistical significance found in tenogenic gene expression, including collagen type I (COL1, p ​= ​0.86), tenomodulin (TNMD, p ​= ​0.837) and scleraxis (SCX, p ​= ​0.331) between PT- and PL-derived tendon cells. An age stratification analysis found no effect on growth and gene expression. COL1 was found to be higher in males when compared to females (P ​< ​0.001), but otherwise no difference was seen in growth and gene expression in the gender analysis. No postbiopsy clinical complications were reported for either group. ConclusionThis study has shown that the growth and bioactivities of tendon cells from tendon biopsies for OrthoATI™ are not affected by tendon donor site and age. Level of evidenceIV.

Abstract 3090: Development and performance of the National Cancer Institute’s HTS384 NCI60 screen: A modernized platform to support drug discovery and development by the worldwide cancer research community

Abstract The NCI60 screen was established in the 1980s and introduced in the 1990s as a screening service for the worldwide cancer research community. The screen features 60 human tumor cell lines that represent 9 cancer types including non-small cell lung, colon, central nervous system, ovarian, renal, prostate and breast, as well as leukemia and melanoma. On a weekly basis, synthetic molecules, natural products, and biologics are screened against the 60-cell line panel to evaluate their anticancer potential. On average, more than 13,000 compounds are screened annually for investigators throughout the world. Cell growth and cytotoxicity were assessed by the sulforhodamine B (SRB) assay, performed in a 96-well format, that measures cellular protein content with an absorbance readout and enabled unprecedented throughput in the 1980s. Although the SRB assay supported a robust screening platform for three decades, its sensitivity and throughput are limited. Recently the NCI’s DCTD introduced the HTS384 NCI60 as a modernized screening platform. While the same 60 cell lines are evaluated, the HTS384 NCI60 is fully automated and performed in a 384-well format to enable a higher throughput. Additionally, the 48-h test agent exposure period of the SRB assay was increased to 72 h, which may result in lower 50% growth inhibition values (GI50) for some agents. A highly sensitive CellTiter-Glo luminescence readout for cell viability, based on cellular ATP content, was selected to enable comparisons of the NCI60 monolayer data to 3D cell culture models where the same assay chemistry can be applied. The HTS384 NCI60 was evaluated by screening a library of 1,003 U.S. Food and Drug Administration-approved and investigational oncology agents at five concentrations. Assay performance of the 60 cell lines was assessed from the controls of 30 - 60 microplates per cell line. The average doubling time of the 60 cell lines during the 72-h exposure period ranged between 19 h for NCI-H460 (17 - 23 h, n = 57) to 117 h for MDA-MB-468 (43 - 272 h, n = 60). The average signal-to-background ratio of all 60 cell lines was 89 (3,413 microplates) and ranged from 6 for OVCAR-5 (3 - 13, n = 54) to 229 for SF-539 (141 - 566, n = 60). The average coefficient of variation for microplate vehicle controls (n = 14) of all 60 cell lines (n = 3,413) was 5.2% and ranged from 3.2% for SK-MEL-28 (1.4 - 7.7%, n = 60) to 11.1% for HL-60(TB) (5.2 - 20.2%, n = 59). The average Z’-factor value of all 60 cell lines (n = 3,413) was 0.82 and ranged between 0.66 for HL-60(TB) (0.39 - 0.84, n = 59) to 0.89 for MALME-3M (0.79 - 0.95, n = 59), SF-295 (0.49 - 0.97, n = 59), SK-MEL-28 (0.74 - 0.95, n = 60), and UO-31 (0.8 - 0.94, n = 54). The development and performance of the HTS384 NCI60 screen will be described. This project was funded in part with federal funds from the NCI, NIH, under contract no. HHSN261201500003I. Citation Format: Nathan P. Coussens, Thomas S. Dexheimer, Eric M. Jones, Thomas Silvers, John R. Britt, Ronald C. Taylor, Mark W. Kunkel, James H. Doroshow, Beverly A. Teicher. Development and performance of the National Cancer Institute’s HTS384 NCI60 screen: A modernized platform to support drug discovery and development by the worldwide cancer research community [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 3090.

De novo genome assembly and pan-genome analysis of the fast-growing Indian isolates of Synechococcus elongatus: Potential chassis for bioproduction

Cyanobacteria are explored as phototrophic cell factories for the conversion of CO2 to chemicals. Although several cyanobacterial platforms have been established, discovering novel cyanobacterial strains with different growth and metabolic traits would be advantageous. Here, we describe de novo genome assembly and pan-genome analysis of eight fast-growing Indian isolates of Synechococcus elongatus, displaying an average doubling time of 3–4 h. The draft genome sequences of S. elongatus PCC 11801 and PCC 11802 were earlier reported by our group. However, here we present circular un-gapped genome sequences of all the eight strains. Their pan-genome analysis showed that these strains form a distinct sub-clade within the S. elongatus clade, and are closely related to a widely used cyanobacterium S. elongatus PCC 7942. Pan-genome and extra-chromosomal DNA sequence analyses further revealed intriguing features, including CRISPR-associated protein genes, circular episomal elements, and other essential genes which were previously not reported for this clade. Further, from bio-engineering perspective, we optimized their transformation using neutral site integrative plasmids. The heterologous protein expression was confirmed using eYFP reporter system, and validated by engineering a mannitol biosynthesis pathway in these strains. Although the strains exhibited comparable eYFP fluorescence, the mannitol production varied significantly, indicating physiological differences among the strains. The maximum mannitol was obtained from S. elongatus IITB6 strain. Overall, this work encompasses comparative growth analysis of the eight Indian isolates of S. elongatus, their genome sequences and pan-genome analysis. We demonstrated their potential as phototrophic cell factories, providing cyanobacterial bio-chassis options.

Global Publication Output of Tinospora cordifolia (Medicinal Plant) Research: A Scientometric Study

Abstract: Scientometrics is described as a technique for analysing a researcher's quantitative research output. This study examines scientometric analysis on Tinospora cordifolia, medicinal plant by measuring the year-wise distribution of articles, annual growth rate, authorship pattern, author productivity, relative growth rates, article doubling time, degree of author collaboration, ranked list of authors, and distribution of publications output by broad topic areas. By observing the output, we found that a maximum of 166 articles (25.75%) were published in 2021. According to the authorship pattern, 40 publications out of 1054 were written by a single author. There are 227 two-author papers, 216 three-author papers, and 206 four-author papers. Author productivity is 0.238. This indicates that production per author is just 23.80% on average, while the average number of authors per manuscript is 4.20. The average doubling time is 0.969 and the relative growth rate (RGR) is 0.68. The overall cooperation rate is 0.96. India ranks first, having published 900 articles (0.85%) out of a total of 1054 articles. By publishing 22 publications, Maharishi Dayanand University and Banaras Hindu University have taken the lead. The University Grants Commission funded 52 articles, with Dabur, R ranking first with 12 papers published.

Effects of different host plants on the growth, development, and fecundity of Phthorimaea absoluta (Lepidoptera: Gelechiidae): an evaluation based on the age-stage two-sex life table.

This study aimed to investigate the growth and development parameters of Phthorimaea absoluta (Meyrick) population at each stage when feeding on 4 host plants: Lycopersicon esculentum, Solanum tuberosum, Solanum melongena, and Nicotiana tabacum. The objective was to predict population dynamics and develop appropriate control strategies. The age-stage sex-life table was used to evaluate survival rate, fecundity, life expectancy, reproductive value, population parameters, and population growth prediction of P. absoluta after feeding on the 4 Solanaceae plants. The results showed significant variations in the fecundity parameters of P. absoluta among the different host plants. The L. esculentum population exhibited the highest average egg-laying period (13.17 ± 0.61 days) and average egg production (219.31 ± 21.02 eggs), while N. tabacum had the lowest values (4.56 ± 0.26 days and 26.08 ± 2.53 eggs, respectively). The gross reproduction rate of P. absoluta feeding on L. esculentum was 146.43 ± 21.00, which was 1.80, 3.77, and 6.39 times higher compared to S. tuberosum, S. melongena, and N. tabacum, respectively. The average age period and population doubling time of P. absoluta feeding on L. esculentum were lower than those of the other 3 host plants. These results indicated that while P. absoluta can complete a generation on L. esculentum, S. tuberosum, S. melongena, and N. tabacum, L. esculentum is the most suitable host for its growth and development. Therefore, in the occurrence and adjacent areas of P. absoluta, relevant authorities should promptly monitor and control its population in the planting areas of Solanaceae plants to prevent further spread.

Establishment of Primary Adult Skin Fibroblast Cell Lines from African Savanna Elephants (Loxodonta africana).

Following population declines of the African savanna elephant (Loxodonta africana) across the African continent, the establishment of primary cell lines of endangered wildlife species is paramount for the preservation of their genetic resources. In addition, it allows molecular and functional studies on the cancer suppression mechanisms of elephants, which have previously been linked to a redundancy of tumor suppressor gene TP53. This methodology describes the establishment of primary elephant dermal fibroblast (EDF) cell lines from skin punch biopsy samples (diameter: ±4 mm) of African savanna elephants (n = 4, 14-35 years). The applied tissue collection technique is minimally invasive and paves the way for future remote biopsy darting. On average, the first explant outgrowth was observed after 15.75 ± 6.30 days. The average doubling time (Td) was 93.02 ± 16.94 h and 52.39 ± 0.46 h at passage 1 and 4, respectively. Metaphase spreads confirmed the diploid number of 56 chromosomes. The successful establishment of EDF cell lines allows for future elephant cell characterization studies and for research on the cancer resistance mechanisms of elephants, which can be harnessed for human cancer prevention and treatment and contributes to the conservation of their genetic material.

Roles of bovine sialoglycoproteins for anti-skin aging and accelerating skin wound healing.

Fibroblasts are the most predominant cell subpopulation in the dermal layer of human skin, they play an important role in maintaining skin architecture and function. The senescence of fibroblasts is one of major causes of skin aging and chronic wound in the elderly, which is accompanied with a reduction of α2,6-sialylation on the cell surface. In this study, we investigated the effects of the bovine sialoglycoproteins on normal human dermal fibroblasts (NHDF). The results showed that bovine sialoglycoproteins could promote the proliferation and migration of NHDF cells, and accelerate the contraction of fibroblast-populated collagen lattice (FPCL). The average doubling time of NHDF cells treated with bovine sialoglycoproteins (0.5 mg/mL) was 31.1 ± 1.0 h whereas that was 37.9 ± 2.7 h for the control (p ˂ 0.05). Moreover, the expression of basic fibroblast growth factor (FGF-2) was upregulated, while that of transforming growth factor-beta 1 (TGF-β1) and human type I collagen (COL-I) were downregulated in treated NHDF cells. Furthermore, bovine sialoglycoproteins treatment significantly enhanced the α2,6-sialylation on the cell surfaces, which was consistent with the upregulation of α2,6-sialyltransferase I (ST6GAL1) expression. These results indicated that the bovine sialoglycoproteins might be developed as a reagent against skin aging in the cosmetic industry, or as a new candidate for accelerating skin wound healing and inhibiting scar formation.

Mouse Fibroblast L929 Cell Line as a Useful Tool for Replication and Adaptation of Infectious Bursal Disease Virus.

Infectious bursal disease virus (IBDV) causes a highly contagious disease associated with immunosuppression in young chickens. Production of either egg-based or primary cell-based high-quality vaccines requires time-consuming and costly procedures. To determine a suitable cell line for IBDV replication, L929 cell line was a candidate for the growth kinetics processing of the virus. The L929 cells were proliferated in monolayer, and doubling time was calculated. Replication kinetics an IBDV isolate at the multiplicity of infection 0.1 PFU/cell were determined using virus titration. To adapt IBDV on L929 cells, seven consecutive passages were performed. Virus titer and levels of apoptosis were quantitatively analyzed at each passage. The viral VP2 gene was amplified and sequenced in three passages. An average doubling time of 21 h was estimated for monolayers of L929 cells. Although during early passages, virus growth did not produce a clear cytopathic effect (CPE), an increase in IBDV titers was observed. Serial passages led to the evidence of marked CPEs and an increase in the virus titer in the third passage. During the fourth to seventh passages, consistent CPEs characterized by the formation of granulated and round cells were evident within 24 to 48 hours post-inoculation. The titer of the virus was increased in the third passage onwards to peak in the fourth and constant at 5.9 TCID50 until the end passage. The IBDV replication in connection with DNA fragmentation and FITC, revealed the characteristic picture of apoptosis in a time-dependent manner. We found that the IBDV could easily be adapted to L929 cells, increasing virus yields by about two orders of magnitude. These results indicated that the cell line may be useful in the production of efficient virus particles.

Spread and seasonality of COVID-19 pandemic confirmed cases in sub-Saharan Africa: experience from Democratic Republic of Congo, Nigeria, Senegal, and Uganda

BackgroundThe COVID-19 pandemic has impacted the world negatively with huge health and socioeconomic consequences. This study estimated the seasonality, trajectory, and projection of COVID-19 cases to understand the dynamics of the disease spread and inform response interventions.MethodDescriptive analysis of daily confirmed COVID-19 cases from January 2020 to 12th March 2022 was conducted in four purposefully selected sub-Saharan African countries (Nigeria, Democratic Republic of Congo (DRC), Senegal, and Uganda). We extrapolated the COVID-19 data from (2020 to 2022) to 2023 using a trigonometric time series model. A decomposition time series method was used to examine the seasonality in the data.ResultsNigeria had the highest rate of spread (β) of COVID-19 (β = 381.2) while DRC had the least rate (β = 119.4). DRC, Uganda, and Senegal had a similar pattern of COVID-19 spread from the onset through December 2020. The average doubling time in COVID-19 case count was highest in Uganda (148 days) and least in Nigeria (83 days). A seasonal variation was found in the COVID-19 data for all four countries but the timing of the cases showed some variations across countries. More cases are expected in the 1st (January-March) and 3rd (July–September) quarters of the year in Nigeria and Senegal, and in the 2nd (April-June) and 3rd (October-December) quarters in DRC and Uganda.ConclusionOur findings show a seasonality that may warrant consideration for COVID-19 periodic interventions in the peak seasons in the preparedness and response strategies.

A Beefy-R culture medium: Replacing albumin with rapeseed protein isolates

The development of cost-effective serum-free media is essential for the economic viability of cultured meat. A key challenge facing this goal is the high-cost of recombinant albumin which is necessary in many serum-free media formulations, including a recently developed serum-free medium for bovine satellite cell (BSC) culture termed Beefy-9. Here we alter Beefy-9 by replacing recombinant albumin with rapeseed protein isolate (RPI), a bulk-protein solution obtained from agricultural waste through alkali extraction (pH 12.5), isoelectric protein precipitation (pH 4.5), dissolution of physiologically soluble proteins (pH 7.2), and concentration of proteins through 3 kDa ultrafiltration. This new medium, termed Beefy-R, was then used to culture BSCs over four passages, during which cells grew with an average doubling time of 26.6 h, showing improved growth compared with Beefy-9. In Beefy-R, BSCs maintained cell phenotype and myogenicity. Together, these results offer an effective, low-cost, and sustainable alternative to albumin for serum-free culture of muscle stem cells, thereby addressing a key hurdle facing cultured meat production.

ANALYSES OF BIOPSIED TISSUES IN AUTOLOGOUS TENOCYTE THERAPY FOR TREATMENT OF TENDINOPATHY

Autologous tendon cell injection (ATI) is a promising non-surgical treatment for tendinopathies and tendon tear that address its underlying pathology. The procedure involves harvesting autologous tendon tissue, the isolation of the tendon cells, expansion under quality assured GMP cell laboratory and the injection of the tendon cells via U/S into the degenerative tendon tissue. In clinical practice, the patella (PT) and palmaris longus (PL) tendons are common sites used for tendon tissue biopsy. The objective of this study is to compare the tendon cell quality, identity, purity, doubling time and yield of cells between PT and PL tendons for ATI.Tendon tissue biopsies were harvested from PT via U/S using a 14-gauge needle or resected surgically from the PL tendon. The biopsies were transported to a GMP cell laboratory, where tendon cells were isolated, cultured and expanded for 4 to 6 weeks, and analysed for viability, cell doubling time, cellular characteristics including cell purity, potency and identity (PPI).Tendon samples from 149 patients were analysed (63 PT). Average biopsy weight was 62mg for PT and 119mg for PI (p&lt;0.001). Average cell doubling time (83.9 vs 82.7 hours), cellular yield (16.2 vs 15.2×106), viability (98.7 vs 99.0%) and passage number (3 vs 3) were not significantly different between tendons. Additionally, ddPCR analyses showed no differences of PPI including tendon cell markers of collagen type I, scleraxis and tenomodulin. No post-biopsy complications or contamination were reported for either group. Assessing tendon tissue from palmaris tendon is relatively easier.Tendon tissue biopsy tissue for autologous tendon cell therapy can be obtained from either the PT or PL tendons. Tendon cells isolated from PT and PL were equal in growth characteristics and PPI. There are no differences in the quality of tendon cells isolated from the PT or PL.

Analysis and mapping of global research publications on shift work (2012–2021)

BackgroundThe main objective of the study was to identify research trends, collaboration patterns, and the most impactful publications in the field of shift work.MethodsDocuments published in scientific journals indexed in the Scopus database on shift work were retrieved and analyzed using the title/abstract search methodology. The study period was from January 1st, 2012, to December 31st, 2021.ResultsTwo thousand three hundred twenty-eight documents were retrieved with an h-index of 71 and an average number of 4.5 authors per document. The cumulative number of publications showed a linear growth pattern, while that of citations showed an exponential pattern. The most frequent author keywords, excluding keywords related to shift work, were sleep, fatigue, and nursing. The average annual growth rate was 4.3, and the average doubling time was 3.2. No significant correlation was found between the number of publications and national income among prolific countries. Cross-country research collaboration was weak while the degree of author-author collaboration was relatively high. The Chronobiology International journal was the most prolific, while Harvard University was the most active institution in the field of shift work.ConclusionsGiven the volume and the negative health impact of shift work, better human resource management is needed to create safer and healthier working schedules.

Cell size homeostasis under the circadian regulation of cell division in cyanobacteria

Bacterial cells maintain their characteristic cell size over many generations. Several rod-shaped bacteria, such as Escherichia coli and the cyanobacteria Synechococcus elongatus, divide after adding a constant length to their length at birth. Through this division control known as the adder mechanism, perturbation in cell length due to physiological fluctuation decays over generations at a rate of 2−1 per cell division. However, previous experiments have shown that the circadian clock in cyanobacteria reduces cell division frequency at a specific time of day under constant light. This circadian gating should modulate the division control by the adder mechanism, but its significance remains unknown. Here we address how the circadian gating affects cell length, doubling time, and cell length stability in cyanobacteria by using mathematical models. We show that a cell subject to circadian gating grows for a long time, and gives birth to elongated daughter cells. These elongated daughter cells grow faster than the previous generation, as elongation speed is proportional to cell length and divide in a short time before the next gating. Hence, the distributions of doubling time and cell length become bimodal, as observed in experimental data. Interestingly, the average doubling time over the population of cells is independent of gating because the extension of doubling time by gating is compensated by its reduction in the subsequent generation. On the other hand, average cell length is increased by gating, suggesting that the circadian clock controls cell length. We then show that the decay rate of perturbation in cell length depends on the ratio of delay in division by the gating τG to the average doubling time τ0 as 2τG/τ0−1. We estimated τG≈2.5, τ0≈13.6 hours, and τG/τ0≈0.18 from experimental data, indicating that a long doubling time in cyanobacteria maintains the decay rate similar to that of the adder mechanism. Thus, our analysis suggests that the acquisition of the circadian clock during evolution did not impose a constraint on cell size homeostasis in cyanobacteria.

Simple and effective serum-free medium for sustained expansion of bovine satellite cells for cell cultured meat

Cell-cultured meat offers the potential for a more sustainable, ethical, resilient, and healthy food system. However, research and development has been hindered by the lack of serum-free media that enable the robust expansion of relevant cells (e.g., muscle satellite cells) over multiple passages. Recently, a low-cost serum-free media (B8) was described for pluripotent stem cells. Here, B8 is adapted for bovine satellite cells through the addition of a single component, recombinant albumin, which renders it suitable for long-term satellite cell expansion without sacrificing myogenicity. This new media (Beefy-9) maintains cell growth over the entire period tested (seven passages), with an average doubling time of 39 h. Along with demonstrated efficacy for bovine cells, Beefy-9 offers a promising starting-point for developing serum-free media for other meat-relevant species. Ultimately, this work offers a foundation for escaping cultured meat research’s reliance on serum, thereby accelerating the field.

Advent Of Omicron: An Attempt to Decode the Third Wave Covid Variant

Currently, severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) has spread worldwide as an Omicron (B.1.1.529) variant, after alpha, beta, gamma, Delta. World Health Organization (WHO) has identified the Omicron variant as a variant of concern due to its heavily mutated nature. Phylogenetically, this variant with more than 50 mutations is very different from other variants. With an average doubling time of two days, the Omicron variant spreads rapidly. However, it has been milder than the Delta. Although previous infection and vaccination do not protect against infection with Omicron, they do appear to protect against hospitalization and severe disease. It is likely that Omicron will have enormous indirect effects, such as lockdowns, restrictions, travel bans, economic losses, infections of healthcare workers, and an overwhelming of healthcare facilities. However, as with previous variants, Omicron's direct effects are expected to be mild. Nevertheless, the indirect effects on mental, physical, and social health may be considerable. It is recommended to for all the people to follow the COVID-19 behaviours. In this review, we focused on the emergence, severity, genomics, effectiveness of vaccines, and treatment and management strategy against the Omicron variant, which will be helpful for further investigation of a new variant of SARS‐CoV‐2.

PD54-06 ACTIVE OBSERVATION OF BIOCHEMICAL RECURRENCE WITHOUT TREATMENT FOLLOWING RADICAL PROSTATECTOMY: LONG TERM ANALYSIS OF OUTCOMES

You have accessJournal of UrologyCME1 May 2022PD54-06 ACTIVE OBSERVATION OF BIOCHEMICAL RECURRENCE WITHOUT TREATMENT FOLLOWING RADICAL PROSTATECTOMY: LONG TERM ANALYSIS OF OUTCOMES Erica Huang, Linda My Huynh, Adam Gordon, Ryan Chandhoke, Blanca Morales, Douglas Skarecky, Joshua Tran, and Thomas Ahlering Erica HuangErica Huang More articles by this author , Linda My HuynhLinda My Huynh More articles by this author , Adam GordonAdam Gordon More articles by this author , Ryan ChandhokeRyan Chandhoke More articles by this author , Blanca MoralesBlanca Morales More articles by this author , Douglas SkareckyDouglas Skarecky More articles by this author , Joshua TranJoshua Tran More articles by this author , and Thomas AhleringThomas Ahlering More articles by this author View All Author Informationhttps://doi.org/10.1097/JU.0000000000002631.06AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookLinked InTwitterEmail Abstract INTRODUCTION AND OBJECTIVE: Biochemical recurrence (BCR) following radical prostatectomy (RP) is an unreliable predictor of metastatic progression or prostate cancer death, potentially resulting in overtreatment. Little has been published on identification and observation of men without treatment via radiation (RT) and/or androgen deprivation (ADT). The present study seeks to characterize findings of men managed using PSA doubling time (DT) kinetics to direct active observation (AO). METHODS: A retrospective cohort analysis of 1864 men undergoing RP between June 2002 and September 2019 was conducted. BCR (PSA >0.2 ng/dl, x2) patients were assessed for treatment intervention (RT and/or ADT) versus observation with DT kinetics. Initial risk was determined as a DT <12 month. Further assessment was based on DT change over time. Patients with rapidly decreasing DT were treated; increasing or slowly decreasing DT were observed without treatment. RESULTS: Median follow-up was 7.3 years (IQR 3.9-10.7). 407/1864 (21.8%) experienced BCR. 136/407 (33.4%) were observed without RT and/or ADT, at 0% PCSM and average current DT 26.0±19.9 months. Patient with lower pGGG’s had longer DT’s (p=0.02). 93/136 (68.4%) patients had increasing DT’s at last follow-up, while patients with decreasing DT’s (37/136, 27.2%) were characterized by long DT’s (mean 19.36 mos, calculated from first 4 PSA’s post-RP) and slowly decreasing DT’s (Table 1).Presently, 69 (50%) have been actively observed for 7.3-18 years, with no PCSM. All PCSM’s occurred in higher risk patients who were treated (Figure 1, p <0.001). CONCLUSIONS: This suggests that a significant portion (33.4%) of men develop a benign BCR post-RARP without need for RT and/or ADT, with 0% PCSM (median 7.3 years). These men are characterized by long DT’s and increasing or slowly decreasing DT kinetics. Source of Funding: N/A © 2022 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 207Issue Supplement 5May 2022Page: e917 Advertisement Copyright & Permissions© 2022 by American Urological Association Education and Research, Inc.MetricsAuthor Information Erica Huang More articles by this author Linda My Huynh More articles by this author Adam Gordon More articles by this author Ryan Chandhoke More articles by this author Blanca Morales More articles by this author Douglas Skarecky More articles by this author Joshua Tran More articles by this author Thomas Ahlering More articles by this author Expand All Advertisement PDF DownloadLoading ...

Enhanced proliferation and differentiation of human mesenchymal stem cells in the gravity-controlled environment.

Human bone marrow mesenchymal stem cells (hMSCs) present a promising cell source with the potential to be used for curing various intractable diseases, and it is expected that the development of regenerative medicine employing cell-based therapy would be significantly accelerated when such methods are established. For that, powerful methods for selective growth and differentiation of hMSCs should be developed. We developed an efficient method for hMSC proliferation and differentiation into osteoblasts and adipocytes using gravity-controlled environments. The results indicate that the average doubling time of hMSCs cultured in a regular maintenance medium under microgravity conditions (0.001 G) was 1.5 times shorter than that of cells cultured under natural gravity conditions (1.0G). Furthermore, 99.2% of cells grown in the microgravity environment showed the expression of hMSC markers, as indicated by flow cytometry analysis. Osteogenic and adipogenic differentiation of hMSCs expanded in the microgravity environment was enhanced under microgravity and hypergravity conditions, respectively, as evidenced by the downregulation of hMSC markers and upregulation of osteoblast and adipocyte markers, respectively. Most cells differentiated into osteoblasts in the microgravity environment after 14 days (~80%) and adipocytes in the hypergravity environment after 12 days (~90%). Our results indicate that hMSC proliferation and selective differentiation into specific cell lineages could be promoted under microgravity or hypergravity conditions, suggesting that cell culture in the gravity-controlled environment is a useful method to obtain cell preparations for potential clinical applications.