EFFECTS OF SOME AMINO ACID ANALOGUES ON BACILLUS CEREUS SPORULATION USING STATIC AND SHAKEN CULTURES

1963 ◽  
Vol 9 (6) ◽  
pp. 791-797 ◽  
Author(s):  
John P. Perkins ◽  
Daniel D. Louie ◽  
John N. Aronson

The possible utility of static culture conditions for sporulation studies was evaluated. The effects of a series of potential amino acid antagonists on the growth and sporulation of a strain of Bacillus cereus in a defined medium were compared under both static and shaken culture conditions. A randomly picked series of 24 analogues was observed to produce all of the possible effects (no inhibition of growth or sporulation, inhibition of growth, inhibition of sporulation, delay of growth and sporulation) with no important qualitative differences between the shaken and static systems. The commonly accepted premise that shaken cultures must be used for sporulation studies has no general validity; the simpler technique of static culture may have great value for observation of the developmental stages of sporulation.

Zygote ◽  
2006 ◽  
Vol 14 (3) ◽  
pp. 181-187 ◽  
Author(s):  
R.M. Garcia-Garcia ◽  
V. Dominguez ◽  
A. Gonzalez-Bulnes ◽  
A. Veiga-Lopez ◽  
M.J. Cocero

SummaryThis study evaluated the final output and quality of in vitro produced blastocysts derived from in vivo recovered sheep embryos cultured at various early developmental stages to blastocyst. A total of 270 embryos were recovered from the oviduct, at different days of the early luteal phase, and were classified into three different developmental stages: 2- to 4-cell (n = 93); 5- to 8-cell (n = 92) and 9- to 12-cell (n = 85). The effect of culture conditions was studied, at the same time, by randomly allocating the embryos to one of four groups: three groups of culture with fresh oviduct monolayers (2, 4 and 5 days old) and a fourth group with 2-day monolayers derived from frozen-thawed oviduct cells. Two control groups were established: first, embryos cultured in semi-defined medium (n = 29) and, second, blastocysts obtained in vivo and cryopreserved (n = 43). Influence on blastocyst yield of embryo developmental stage at the start of culture was statistically significant (p < 0.001). Two- to four-cell embryos showed a significantly lower developmental rate (67.7%) than the 5- to 8-cell (83.6%; p < 0.001) and 9- to 12-cell groups (90.5%; p < 0.0001) and lower quality in terms of blastocyst cryotolerance (56.0 vs. 83.7%; p < 0.005). There were no detected effects relating to the age or handling of the monolayer on the embryo developmental rate, but the day of blastocyst appearance was different between embryos cultured on monolayers derived from fresh or frozen-thawed cells (p < 0.0001); the main influence was on the group of 9- to 12-cell embryos (p < 0.0001). Current results confirm the temporal sensitivities of sheep embryos to in vitro culture, regardless of the culture conditions.


1958 ◽  
Vol 36 (1) ◽  
pp. 861-868
Author(s):  
H. E. Swim ◽  
R. F. Parker

A permanent line of altered human fibroblasts, strain U12-705, was found to require arginine, cystine, glutamine, histidine, isoleucine, leucine, lysine, methionine, phenylalanine, tryptophan, tyrosine, and valine for growth in a defined medium supplemented with 2.5% (v/v) dialyzed chick embryo extract and 5% dialyzed horse serum. In the absence of any of the essential amino acids the cells not only fail to proliferate but undergo degenerative changes which increased with time. The omission of alanine, aspartic acid, glutamic acid, glycine, hydroxyproline, and proline either separately or collectively does not alter the rate of growth or result in changes in the appearance of the cells. Cysteine and glutathione are equally as effective as cystine in promoting the growth of U12-705. None of the D-enantiomorphs of the essential amino acids will effectively replace the corresponding L-isomer. Single D-amino acids are not inhibitory when added to the medium in 5 times the concentration of the L-amino acid. The minimum concentrations of essential amino acids which permit optimal proliferation under the conditions employed range from 0.005 to 0.5 mM. Essential amino acids with the exception of glutamine, isoleucine, leucine, threonine, and valine are toxic for U12-705 when employed at a concentration of 5 mM. Toxic manifestations vary with the amino acid and range from cytologic changes in the cells without a significant decrease in the growth rate to complete inhibition of growth and extensive cellular degeneration.


1958 ◽  
Vol 36 (8) ◽  
pp. 861-868 ◽  
Author(s):  
H. E. Swim ◽  
R. F. Parker

A permanent line of altered human fibroblasts, strain U12-705, was found to require arginine, cystine, glutamine, histidine, isoleucine, leucine, lysine, methionine, phenylalanine, tryptophan, tyrosine, and valine for growth in a defined medium supplemented with 2.5% (v/v) dialyzed chick embryo extract and 5% dialyzed horse serum. In the absence of any of the essential amino acids the cells not only fail to proliferate but undergo degenerative changes which increased with time. The omission of alanine, aspartic acid, glutamic acid, glycine, hydroxyproline, and proline either separately or collectively does not alter the rate of growth or result in changes in the appearance of the cells. Cysteine and glutathione are equally as effective as cystine in promoting the growth of U12-705. None of the D-enantiomorphs of the essential amino acids will effectively replace the corresponding L-isomer. Single D-amino acids are not inhibitory when added to the medium in 5 times the concentration of the L-amino acid. The minimum concentrations of essential amino acids which permit optimal proliferation under the conditions employed range from 0.005 to 0.5 mM. Essential amino acids with the exception of glutamine, isoleucine, leucine, threonine, and valine are toxic for U12-705 when employed at a concentration of 5 mM. Toxic manifestations vary with the amino acid and range from cytologic changes in the cells without a significant decrease in the growth rate to complete inhibition of growth and extensive cellular degeneration.


Author(s):  
Lucia De Marchi ◽  
Carlo Pretti ◽  
Alessia Cuccaro ◽  
Matteo Oliva ◽  
Federica Tardelli ◽  
...  

AbstractThe phylum Porifera and their symbionts produce a wide variety of bioactive compounds, playing a central role in their ecology and evolution. In this study, four different extracts (obtained by non-polar and semi-polar extraction methodologies) of the Mediterranean sponge Ircinia oros were tested through a multi-bioassay integrated approach to assess their antifouling potential. Tests were performed using three common species, associated with three different endpoints: the marine bacterium Aliivibrio fischeri (inhibition of bioluminescence), the marine diatom Phaeodactylum tricornutum (inhibition of growth), and different development stages of the brackish water serpulid Ficopomatus enigmaticus (gametes: sperm motion, vitality inhibition and cellular damage; larvae: development; adults: AChE (acetylcholinesterase)-inhibitory activity). The effects of extracts were species specific and did not vary among different extraction methodologies. In particular, no significant reduction of bioluminescence of A. fischeri was observed for all tested samples. By contrast, extracts inhibited P. tricornutum growth and had toxic effects on different F. enigmaticus’ developmental stages. Our results suggest that the proposed test battery can be considered a suitable tool as bioactivity screening of marine natural products.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Kornphimol Kulthong ◽  
Guido J. E. J. Hooiveld ◽  
Loes Duivenvoorde ◽  
Ignacio Miro Estruch ◽  
Victor Marin ◽  
...  

AbstractGut-on-chip devices enable exposure of cells to a continuous flow of culture medium, inducing shear stresses and could thus better recapitulate the in vivo human intestinal environment in an in vitro epithelial model compared to static culture methods. We aimed to study if dynamic culture conditions affect the gene expression of Caco-2 cells cultured statically or dynamically in a gut-on-chip device and how these gene expression patterns compared to that of intestinal segments in vivo. For this we applied whole genome transcriptomics. Dynamic culture conditions led to a total of 5927 differentially expressed genes (3280 upregulated and 2647 downregulated genes) compared to static culture conditions. Gene set enrichment analysis revealed upregulated pathways associated with the immune system, signal transduction and cell growth and death, and downregulated pathways associated with drug metabolism, compound digestion and absorption under dynamic culture conditions. Comparison of the in vitro gene expression data with transcriptome profiles of human in vivo duodenum, jejunum, ileum and colon tissue samples showed similarities in gene expression profiles with intestinal segments. It is concluded that both the static and the dynamic gut-on-chip model are suitable to study human intestinal epithelial responses as an alternative for animal models.


Zygote ◽  
2020 ◽  
Vol 28 (2) ◽  
pp. 154-159
Author(s):  
Juliana I. Candelaria ◽  
Anna C. Denicol

SummaryPreantral follicles are a potential reservoir of oocytes to be used in assisted reproductive technologies. With the increasing interest in developing techniques to grow preantral follicles in vitro, and as the bovine emerges as an appropriate model species to understand human folliculogenesis, the establishment of an accurate classification of developmental stages is needed. Classification of bovine preantral follicles has been mostly based on histological analysis and estimation models, which may not translate well to correctly characterize preantral follicles isolated from the ovary. In this study, we classified bovine preantral follicles by morphology upon isolation, determined diameter and number of granulosa cells by direct counting, and compared our results with previous studies reporting bovine preantral follicle classification. Follicles were isolated via homogenization of ovary tissue and classified into primary, early secondary and secondary stage based on morphology and number of layers of granulosa cells. Diameter was individually measured and Hoechst 33342 was used as a nuclear stain to count granulosa cells. We found that follicles classified by morphology into primary, early secondary, and secondary had different mean diameter and cell number (P < 0.01); cell number and diameter were positively correlated, as were cell density and cell number in each developmental stage (P < 0.01). Results obtained here were mostly in agreement with previous classifications based on histological sections and on isolated follicles, with some discrepancies. The present data add accuracy to classification of bovine preantral follicles that is critical to optimize culture conditions to produce developmentally competent oocytes.


1971 ◽  
Vol 9 (2) ◽  
pp. 529-537
Author(s):  
G. J. BLAKER ◽  
J. R. BIRCH ◽  
S. J. PIRT

The serum supplement in a defined medium for the growth of HeLa cells could be replaced by protamine-zinc-insulin (0.2 u./ml). Insulin (0.4 u./ml) replaced the growth-stimulatory properties of protamine-zinc-insulin, whilst protamine sulphate (5 µg/ml) was found to be toxic to the cells. The addition of insulin to cultures depleted of insulin increased both cell growth rates and maximum cell populations. In the defined medium, HeLa cells could only utilize glutamate when a small amount of glutamine was included. Glucose, at a level of 2 mg/ml, was shown to limit maximum cell populations. The growth yield from glucose was 295 µg cell dry weight/mg glucose. When the medium glucose concentration was increased to 4 mg/ml, HeLa cell populations in excess of 16 x 105 cells (i.e. 640 µg dry weight)/ml were routinely achieved in the defined medium supplemented with insulin. Growth is then limited by the amino acid supply. Increasing the amino acid concentration of the medium by 50% raised the maximum cell population to 23.5x105 cells (i.e. 940 µg dry weight)/ml.


2021 ◽  
Author(s):  
Ying Lu ◽  
Chongbo Hao ◽  
Shanshan Yu ◽  
Zuan Ma ◽  
Xuelian Fu ◽  
...  

Abstract Background: Abnormal proliferation of fibroblast-like synoviocytes (FLSs) in the synovial lining layer is the primary cause of synovial hyperplasia and joint destruction in rheumatoid arthritis (RA). Currently, the relationship between metabolic abnormalities and FLS proliferation is a new focus of investigation. However, little is known regarding the relationship between amino acid metabolism and RA. Methods: The concentrations of amino acids and cytokines in the synovial fluid of RA (n=9) and osteoarthritis (OA,n=9) were detected by LC-MS/MS and CBA assay, respectively. The mRNA and protein expression of CAT-1 were determined in FLSs isolated from RA and OA patients by real-time PCR and western blotting. MTT assay, cell cycle, apoptosis, invasion and cytokine secretion were determined in FLSs knocked down of CAT-1 using siRNA or treated with D-arginine under normoxic and hypoxic culture conditions. A mouse collagen-induced arthritis (CIA) model was applied to test the therapeutic potential of blocking the uptake of L-arginine in vivo.Results: L-arginine was upregulated in the synovial fluid of RA patients and was positively correlated with elevation of the cytokines IL-1β, IL-6 and IL-8. Further examination demonstrated that cationic amino acid transporter-1 (CAT-1) was the primary transporter for L-arginine and was overexpressed on RA FLSs compared to OA FLSs. Moreover, knockdown of CAT-1 using siRNA or inhibition of L-arginine uptake using D-arginine significantly suppressed L-arginine metabolism, cell proliferation, migration and cytokine secretion in RA FLSs under normoxic and hypoxic culture conditions in vitro but increased cell apoptosis in a dose-dependent manner. Meanwhile, in vivo assays revealed that an L-arginine-free diet or blocking the uptake of L-arginine using D-arginine suppressed arthritis progression in CIA mice. Conclusion: CAT-1 is upregulated and promotes FLS proliferation by taking up L-arginine, thereby promoting RA progression.


1947 ◽  
Vol 85 (1) ◽  
pp. 55-64 ◽  
Author(s):  
Leon L. Miller ◽  
Eric L. Alling

1. Further observations on the utilization of parenterally administered dog hemoglobin show that oral supplements of dl-methionine and l-cystine improve the efficiency of utilization of hemoglobin N, while a fed supplement of dl-isoleucine alone is without effect. 2. When N-isoleucine is added to a fed supplement of methionine or methionine and cystine, the utilization of parenterally given hemoglobin N is even better than with the sulfur-containing amino acids alone. 3. A suggested approach to the problem of designing the quantitatively "ideal" amino acid mixture lies in the definition of what may be called total organism-amino acid patterns of rat, dog, man, etc. These may vary considerably not only at different developmental stages in a given species, but also certainly from one species to another. 4. Further attempts to detect globin in the peripheral circulation have pointed to the need for a highly specific procedure such as that an immunologic method may offer. 5. Reduced hemin in dog plasma migrates with α1-globulin and albumin in veronal buffer at pH 8.5 and the colored zones give strong hemochromogen absorption bands.


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