scholarly journals Fibonacci Sequence-related Phenomenon During Chondrocyte Proliferation of the Gottingen Pig Knee Tibial Plateau

2021 ◽  
Author(s):  
xiao jian wang ◽  
Wei Tian ◽  
Jian-bo Wu ◽  
Jian Zhang
Keyword(s):  
Tibial Plateau ◽  
Fibonacci Sequence ◽  
Related Phenomenon ◽  
Chondrocyte Proliferation ◽  
Logarithmic Growth Phase ◽  
Quantitative Changes ◽  
Full Separation ◽  
Logarithmic Growth ◽  
Time Point

Abstract Background The aim of our study was to observe the quantitative changes in tibial plateau chondrocytes in the proliferation process from normal Gottingen pigs in vitro and compare them with the Fibonacci sequence.Methods Chondrocytes from normal Gottingen pig tibial plateau cartilage were isolated and cultured to the third generation, and the number of chondrocytes was measured to determine whether the chondrocyte growth was at the logarithmic growth phase. Chondrocytes were added to cell culture bottles at very a low density to allow full separation and allow each chondrocyte to grow as independently as possible. Thirty single chondrocytes were selected, and the number of chondrocyte colonies were observed and recorded every day. Results Among the 30 chondrocyte colonies, the changes in the numbers of 16 chondrocyte colonies were 1, 2, 3, 5, 8, 13, 21, 34, 55, 89, 144, 233, 377, 610, and 987, which conformed to the numbers of the Fibonacci sequence.The number of other chondrocyte colonies was lower than corresponding numbers of the Fibonacci sequence at the same time point.Conclusion The numbers of normal Gottingen pig tibial plateau chondrocytes during the proliferation process were in line with the numbers of the Fibonacci sequence.Alignment to the Fibonacci sequence may be the fastest way for changes in the numbers of normal chondrocytes during the proliferation process in vitro.

GROWTH OF PENICILLIN-RESISTANT AND PENICILLIN-SENSITIVE STRAINS OF STAPHYLOCOCCUS AUREUS

1963 ◽  
Vol 9 (2) ◽  
pp. 179-186
Author(s):  
Wendall E. Allen ◽  
Ilda McVeigh
Keyword(s):  
Staphylococcus Aureus ◽  
Stationary Phase ◽  
Growth Phase ◽  
Growth Curves ◽  
Viable Cell ◽  
Fresh Medium ◽  
Logarithmic Growth Phase ◽  
Resistant Strains ◽  
Logarithmic Growth

Ten strains of naturally penicillin-resistant Staphylococcus aureus (obtained from patients), two in vitro derived resistant strains, and two sensitive strains, were grown at 37 C in Antibiotic Assay broth, and viable cell determinations were made at intervals. From these data, growth curves were plotted for each of the strains. The curves for the naturally penicillin-resistant and the sensitive strains are very similar. Little, if any, lag in growth of these strains occurred on transfer from maximum stationary-phase cultures to fresh medium. They grew at approximately the same rate during the logarithmic growth phase, which lasted for 3 to 4 hours; during the maximum stationary phase, about the same number of cells was present per milliliter in cultures of each of these strains. In contrast, the in vitro derived resistant strains underwent a lag of 2 to 6 hours on transfer to fresh medium and grew at a slower rate during the logarithmic growth phase. However, during the maximum stationary phase, which occurred after an incubation period of 24 to 32 hours, the cell titers were approximately the same as those of the naturally resistant and the sensitive strains. When grown in competition with either of the sensitive strains in Antibiotic Assay broth in the absence of penicillin, one of the naturally resistant strains persisted for 14 successive subcultures without any apparent change in ability to tolerate the antibiotic.

scholarly journals Modified PEHPS Medium as an Alternative for theIn VitroCulture ofGiardia lamblia

2014 ◽  
Vol 2014 ◽  
pp. 1-4 ◽  
Author(s):  
Javier Vargas-Villarreal ◽  
Benito D. Mata-Cárdenas ◽  
Magda E. Hernández-García ◽  
Jesús N. Garza-González ◽  
Laura H. De La Garza-Salinas ◽  
...  
Keyword(s):  
Trichomonas Vaginalis ◽  
Culture Medium ◽  
Culture Media ◽  
Logarithmic Growth Phase ◽  
Economic Culture ◽  
The Mean ◽  
Logarithmic Growth ◽  
Axenic Cultivation ◽  
Duplication Time

Commercial culture media present interlot variations in biological activity. We have previously designed a homemade and economic culture medium, PEHPS medium, for the axenic cultivation ofEntamoeba histolyticaandTrichomonas vaginalis. Trophozoites of amoebae and trichomonads grow well in this medium. Furthermore, the medium is stable for several months when stored frozen or refrigerated. The objective of this work was to modify PEHPS medium to support thein vitrogrowth ofGiardia lamblia. Inocula of 5 × 103trophozoites/mL ofG. lambliawere incubated at 36.5°C in modified PEHPS or TYI-S-33 medium. Then, the growths of the threeGiardiastrains in both media were compared. The logarithmic growth phase lasted 72 h; the mean yield of the strains ranged from 10.06 to 11.43 × 105Giardiatrophozoites/mL, and the range of duplication time in the three strains was from 5.67 to 6.06 in modified PEHPS medium. These growth characteristics were not significantly different from those obtained with TYI-S-33 medium. We conclude that modified PEHPS medium might be used for the axenic cultivation ofG. lamblia.

scholarly journals About 4-day Rhythm of Proliferative Activity of Fibroblast-like Cell Cultures Depends on the Environmental Factor

2021 ◽  
Author(s):  
Marina A. Diatroptova ◽  
Anna M. Kosyreva ◽  
Mikhail E. Diatroptov
Keyword(s):  
Cell Cultures ◽  
Proliferative Activity ◽  
Simultaneous Increase ◽  
Embryonic Cells ◽  
Logarithmic Growth Phase ◽  
Infradian Rhythm ◽  
Cell Proliferative Activity ◽  
Embryonic Fibroblast ◽  
Logarithmic Growth

Abstract A study of the 4-day rhythm of the proliferative activity of the embryonic fibroblast-like cells in the logarithmic growth phase was carried out. It was shown that in cell cultures obtained on different days from embryos of different ages, the phase of the 4-day rhythm coincides. In vitro the maxima of the proliferative activity were consistent with the minima of the motor activity of mice. Freezing the culture for 2 or 6 days does not cause a shift in the phase of the 4-day rhythm of cell proliferative activity compare with the unfreezing culture. That indicates the existence of an external synchronizer, which determines the 4-day infradian rhythm of the proliferative activity of embryonic cells. Then we daily thawed samples of single L-929 culture of mice fibroblast-like cells for 22 and 17 days and researched the dynamics of its proliferative activity. We also showed 4-day rhythm of the simultaneous increase in the number of cells for all thawed samples. Taking into account that deep freezing of a culture leads to the cessation of all life processes, the fact we obtained indicates an exogenous mechanism of the formation of about a 4-day rhythm of the proliferative activity of cell culture.

A Micrurgical Method for Preparation of Chromosomes for Electron Microscopy

1967 ◽  
Vol 25 ◽  
pp. 128-129
Author(s):  
Godfrey C. Hoskins
Keyword(s):  
Electron Microscopy ◽  
Mammalian Cells ◽  
Microscope Slide ◽  
Mitotic Apparatus ◽  
Logarithmic Growth Phase ◽  
Clear Area ◽  
Fluid Environment ◽  
A Cell ◽  
Logarithmic Growth

Mammalian cells on coverslips in vitro are used during logarithmic growth phase to obtain many cells in mitosis without the use of mitotic inhibitors.Two short lengths of glass tubing attached by beeswax to a standard microscope slide provide support for the coverslip. The coverslip is placed cell side down to form a chamber with open ends for admission of microneedles and for changing the fluid environment of the cells. This open ended chamber is then filled with a physiologic salt solution such as Hanks or a growth medium such as Eagles.Microneedles governed by deFonbrune micromanipulators are admitted through the open ends of the chamber. A cell in metaphase is located, picked up by microneedle, and carried to a clear area on the coverslip (Fig. 1). The second microneedle may hold the cell while the first is moved sidewise to create an incision in the cell membrane through which the mitotic apparatus may egress.

Yeast Cells as a Test System for Evaluating the Toxicity of Chemicals

1990 ◽  
Vol 17 (3) ◽  
pp. 203-206
Author(s):  
Klaus Stadtlander ◽  
Heidemarie Lawohnus
Keyword(s):  
Partition Coefficients ◽  
Evaluation Study ◽  
Test System ◽  
In Vitro Cytotoxicity ◽  
Yeast Cells ◽  
Logarithmic Growth Phase ◽  
Very High ◽  
Logarithmic Growth ◽  
Key Parameter

The first 13 substances of the MEIC (multicentre evaluation study of in vitro cytotoxicity) project were tested in a test system in which the generation time of yeast cells in their logarithmic growth phase was used as the endpoint. Toxic effects, expressed as EC10, EC20 or EC50 values, were correlated with octanol/water partition coefficients. The correlation was found to be very high, indicating that the lipophilicity of substances is a key parameter for describing the toxicity of chemicals.

Morphological Characterization of Mycobacteriophage R1

1974 ◽  
Vol 32 ◽  
pp. 254-255
Author(s):  
B. L. Soloff ◽  
T. A. Rado
Keyword(s):  
Carbon Source ◽  
Stationary Phase ◽  
Growth Phase ◽  
Minimal Medium ◽  
Morphological Characterization ◽  
Logarithmic Growth Phase ◽  
Complete Lysis ◽  
Lysogenic Culture ◽  
Logarithmic Growth

Mycobacteriophage R1 was originally isolated from a lysogenic culture of M. butyricum. The virus was propagated on a leucine-requiring derivative of M. smegmatis, 607 leu−, isolated by nitrosoguanidine mutagenesis of typestrain ATCC 607. Growth was accomplished in a minimal medium containing glycerol and glucose as carbon source and enriched by the addition of 80 μg/ ml L-leucine. Bacteria in early logarithmic growth phase were infected with virus at a multiplicity of 5, and incubated with aeration for 8 hours. The partially lysed suspension was diluted 1:10 in growth medium and incubated for a further 8 hours. This permitted stationary phase cells to re-enter logarithmic growth and resulted in complete lysis of the culture.

Platelet Aggregation Induced in Vitro by Therapeutic Ultrasound

1977 ◽  
Vol 38 (03) ◽  
pp. 0640-0651 ◽  
Author(s):  
B. V Chater ◽  
A. R Williams
Keyword(s):  
Platelet Aggregation ◽  
Direct Action ◽  
Adenosine Diphosphate ◽  
Ultrasonic Cavitation ◽  
Related Phenomenon ◽  
Release Reaction ◽  
Physical Conditions ◽  
Platelet Aggregates ◽  
Active Substances

SummaryPlatelets were found to aggregate spontaneously when exposed to ultrasound generated by a commercial therapeutic device. At a given frequency, aggregation was found to be a dose-related phenomenon, increasing intensities of ultrasound inducing more extensive and more rapid aggregation. At any single intensity, the extent aggregation was increased as the frequency of the applied ultrasound was decreased (from 3.0 to 0.75 MHz).Ultrasound-induced platelet aggregation was found to be related to overall platelet sensitivity to adenosine diphosphate. More sensitive platelets were found to aggregate spontaneously at lower intensities of sound, and also the maximum extent of aggregation was found to be greater. Examination of ultrasound-induced platelet aggregates by electron microscopy demonstrated that the platelets had undergone the release reaction.The observation that haemoglobin was released from erythrocytes in whole blood irradiated under identical physical conditions suggests that the platelets are being distrupted by ultrasonic cavitation (violent gas/bubble oscillation).It is postulated that overall platelet aggregation is the result of two distinct effects. Firstly, the direct action of ultrasonic cavitation disrupts a small proportion of the platelet population, resulting in the liberation of active substances. These substances produce aggregation, both directly and indirectly by inducing the physiological release reaction in adjacent undamaged platelets.

scholarly journals Abnormal physiological properties and altered cell wall composition in Streptococcus pneumoniae grown in the presence of clavulanic acid.

1997 ◽  
Vol 41 (3) ◽  
pp. 504-510 ◽  
Author(s):  
A Severin ◽  
E Severina ◽  
A Tomasz
Keyword(s):  
Streptococcus Pneumoniae ◽  
High Performance ◽  
Biochemical Properties ◽  
Beta Lactam ◽  
Chromatography Analysis ◽  
Peptide Composition ◽  
Increased Sensitivity ◽  
Altered Cell ◽  
Quantitative Changes

Subinhibitory concentrations of clavulanate caused premature induction of stationary-phase autolysis, sensitization to lysozyme, and reductions in the MICs of deoxycholate and penicillin for Streptococcus pneumoniae. In the range of clavulanate concentrations producing these effects, this beta-lactam compound was selectively bound to PBP 3. Cell walls isolated from pneumococci grown in the presence of clavulanate showed increased sensitivity to the hydrolytic action of purified pneumococcal autolysin in vitro. High-performance liquid chromatography analysis of the peptidoglycan isolated from the clavulanate-grown cells showed major qualitative and quantitative changes in stem peptide composition, the most striking feature of which was the accumulation of peptide species carrying intact D-alanyl-D-alanine residues at the carboxy termini. The altered biological and biochemical properties of the clavulanate-grown pneumococci appear to be the consequences of suppressed D,D-carboxypeptidase activity.

BMP2 Is Required for Postnatal Maintenance of Osteochondral Tissues of the Temporomandibular Joint

Cartilage ◽  
2020 ◽  
pp. 194760352098015
Author(s):  
Mara H. O’Brien ◽  
Eliane H. Dutra ◽  
Shivam Mehta ◽  
Po-Jung Chen ◽  
Sumit Yadav
Keyword(s):  
Age Groups ◽  
Mandibular Condyle ◽  
Bone Morphogenetic Protein 2 ◽  
Matrix Synthesis ◽  
Cartilage Growth ◽  
Chondrocyte Proliferation ◽  
Conditional Deletion ◽  
Morphogenetic Protein

Objective Bone morphogenetic protein 2 (BMP2) plays important roles in cartilage growth and development. Paradoxically, elevated levels of BMP2 leads to hypertrophic differentiation and osteoarthritis of cartilage. We examined the in vivo loss of BMP2 in cells expressing aggrecan of the mandibular condyle and knee. Design Three-week-old BMP2 flox/flox- CreER-positive mice and their Cre-negative littermates were treated with tamoxifen and raised until 3 or 6 months. We also investigated the direct effects of BMP2 on chondrocytes in vitro. Cells from the mandibular condyle of mice were treated with recombinant human BMP2 (rhBMP2) or rhNoggin (inhibitor of BMP2 signaling). Results Conditional deletion of BMP2 caused breakage of the cartilage integrity in the mandibular condyle of mice from both age groups, accompanied by a decrease in cartilage thickness, matrix synthesis, mineralization, chondrocyte proliferation, and increased expression of degeneration markers, while the effects at articular cartilage were not significant. In vitro results revealed that rhBMP2 increased chondrocyte proliferation, mineralization, and differentiation, while noggin induced opposite effects. Conclusions In conclusion, BMP2 is essential for postnatal maintenance of the osteochondral tissues of the mandibular condyle.

Lateral Extra-articular Tenodesis Alters Lateral Compartment Contact Mechanics under Simulated Pivoting Maneuvers: An In Vitro Study

2021 ◽  
pp. 036354652110282
Author(s):  
Niv Marom ◽  
Hamidreza Jahandar ◽  
Thomas J. Fraychineaud ◽  
Zaid A. Zayyad ◽  
Hervé Ouanezar ◽  
...  
Keyword(s):  
Contact Mechanics ◽  
Contact Force ◽  
Contact Stress ◽  
Tibial Plateau ◽  
Cruciate Ligament ◽  
In Vitro Study ◽  
Lateral Compartment ◽  
Lateral Tibial Plateau ◽  
Intact Knee

Background: There is concern that utilization of lateral extra-articular tenodesis (LET) in conjunction with anterior cruciate ligament (ACL) reconstruction (ACLR) may disturb lateral compartment contact mechanics and contribute to joint degeneration. Hypothesis: ACLR augmented with LET will alter lateral compartment contact mechanics in response to simulated pivoting maneuvers. Study Design: Controlled laboratory study. Methods: Loads simulating a pivot shift were applied to 7 cadaveric knees (4 male; mean age, 39 ± 12 years; range, 28-54 years) using a robotic manipulator. Each knee was tested with the ACL intact, sectioned, reconstructed (via patellar tendon autograft), and, finally, after augmenting ACLR with LET (using a modified Lemaire technique) in the presence of a sectioned anterolateral ligament and Kaplan fibers. Lateral compartment contact mechanics were measured using a contact stress transducer. Outcome measures were anteroposterior location of the center of contact stress (CCS), contact force from anterior to posterior, and peak and mean contact stress. Results: On average, augmenting ACLR with LET shifted the lateral compartment CCS anteriorly compared with the intact knee and compared with ACLR in isolation by a maximum of 5.4 ± 2.3 mm ( P < .001) and 6.0 ± 2.6 mm ( P < .001), respectively. ACLR augmented with LET also increased contact force anteriorly on the lateral tibial plateau compared with the intact knee and compared with isolated ACLR by a maximum of 12 ± 6 N ( P = .001) and 17 ± 10 N ( P = .002), respectively. Compared with ACLR in isolation, ACLR augmented with LET increased peak and mean lateral compartment contact stress by 0.7 ± 0.5 MPa ( P = .005) and by 0.17 ± 0.12 ( P = .006), respectively, at 15° of flexion. Conclusion: Under simulated pivoting loads, adding LET to ACLR anteriorized the CCS on the lateral tibial plateau, thereby increasing contact force anteriorly. Compared with ACLR in isolation, ACLR augmented with LET increased peak and mean lateral compartment contact stress at 15° of flexion. Clinical Relevance: The clinical and biological effect of increased anterior loading of the lateral compartment after LET merits further investigation. The ability of LET to anteriorize contact stress on the lateral compartment may be useful in knees with passive anterior subluxation of the lateral tibia.

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