Digital images coupled to PLS regression for pH prediction in sterile culture medium

2022 ◽  
Vol 73 ◽  
pp. 103435
Author(s):  
Ânderson Ramos Carvalho ◽  
Luana Candice Genz Bazana ◽  
Alexandre Meneghello Fuentefria ◽  
Marco Flôres Ferrão
Keyword(s):  
Culture Medium ◽  
Digital Images ◽  
Pls Regression ◽  
Sterile Culture

FURTHER STUDIES ON INDUCED APOGAMY IN FERNS

1962 ◽  
Vol 40 (11) ◽  
pp. 1525-1531 ◽  
Author(s):  
D. P. Whittier ◽  
T. A. Steeves
Keyword(s):  
Carbohydrate Metabolism ◽  
Osmotic Potential ◽  
Culture Medium ◽  
General Applicability ◽  
Sterile Culture ◽  
The One ◽  
Induced Apogamy ◽  
Fern Gametophytes

Apogamous sporophyte formation has been induced in 14 strains of seven species of normal fern gametophytes using a technique similar to the one reported earlier (Whittier and Steeves, Can. J. Bot. 38, 925–930 (1960)). These gametophytes were supplied with suitable concentrations of sugar in the sterile culture medium for certain lengths of time which resulted in the formation of apogamous sporophytes. This investigation demonstrated that sucrose is more effective in inducing apogamy probably because it produces about half the osmotic potential as an equivalent percentage of glucose. Therefore more sugar can be made available to gametophytes before the osmotic potential deleteriously affects the prothallial growth and apogamy. This confirms the work carried out previously using sugar in the medium and it demonstrates that this method has general applicability for inducing apogamy in ferns. The sugar in the medium is felt to modify the carbohydrate metabolism enabling the prothalli to undergo a thickened growth and develop apogamous sporophytes.

scholarly journals Novel model for the in vivo study of central nervous system infection due to Acanthamoeba spp. (T4 genotype)

2009 ◽  
Vol 58 (4) ◽  
pp. 503-508 ◽  
Author(s):  
Parisa Nakhostin Mortazavi ◽  
Graham Goldsworthy ◽  
Ruth Kirk ◽  
Naveed Ahmed Khan
Keyword(s):  
Culture Medium ◽  
Fat Body ◽  
Central Nervous System Infection ◽  
Nutrient Agar ◽  
Migratory Locust ◽  
Mature Adult ◽  
Faecal Pellets ◽  
Sterile Culture ◽  
First Time

In this study it was shown for what is believed to be the first time that the African migratory locust can be used as a model for the study of Acanthamoeba pathogenesis. Mature adult locusts were injected intra-abdominally with 10 μl suspension of 106 Acanthamoeba (a clinical isolate of the T4 genotype) in culture medium, or with the same volume of sterile culture medium. Locusts injected with Acanthamoeba showed significant weight loss and reduced production of faeces compared with control locusts. Furthermore, injection of amoebae killed all of the locusts within 17 days at room temperature, although the speed of kill was temperature and dose dependent. When samples of faecal pellets and various tissues of infected locusts were cultured on non-nutrient agar plates containing bacterial lawns, live amoebae were recovered from haemolymph, flight muscle and fat body samples, but not from faeces. When brains dissected from locusts were incubated with an anti-amoebic drug (100 μM chlorhexidine) to kill extracellular amoebae, and then washed, homogenized and cultured on bacteria-seeded non-nutrient agar plates, only lysates from amoebae-infected locusts were positive for Acanthamoeba. This strongly suggests that amoebae invade the locust brain and, indeed, trophozoites of Acanthamoeba could be identified within the brain in histological sections of brains from infected locusts, but not from uninfected locusts. These findings support the view that locusts can be used as a model for the study of Acanthamoeba pathogenesis in vivo.

Leaching of Pyrite by Acidithiobacillus ferrooxidans Monitored by Electrochemical Methods

2017 ◽  
Vol 262 ◽  
pp. 541-544 ◽  
Author(s):  
Albert Saavedra ◽  
Eduardo Cortón
Keyword(s):  
Culture Medium ◽  
Culture Media ◽  
Electrochemical Methods ◽  
In Situ Monitoring ◽  
Iron Hydroxides ◽  
Current Increase ◽  
Continuous Increase ◽  
Sterile Culture ◽  
Live Bacteria ◽  
Bacterial Attack

The aim of this work was to use electrochemical methods, capable to follow the corrosion of minerals, in order to monitor the progressive attack of the bacteria on the mineral. The assay was performed in a three electrode cell, with pyrite as the working electrode. The tests were performed in the absence and presence of iron; when present it was in low concentration. In order to compare the bacterial attack with other conditions, the study was conducted in three systems: live bacteria in culture media, dead bacteria in culture media, and sterile culture media, used as a control. The initial bacterial concentration was 106 bact.mL-1. To follow the process, current and corrosion potential were calculated. Live bacteria system showed a continuous increase of current with respect to the incubation time, being up to 4-times higher in the condition with iron (the corrosion current is related to the increase of the mineral area, produced by the bacterial attack, which was corroborated identifying by SEM the bacterial fingerprint on the mineral). Dead bacteria and sterile culture medium showed no current increase with respect to time. In addition, voltammetric studies shown that in live bacteria system the surface area increased when the biofilm was present. Whereas, in the dead bacteria system only the presence of some organic compounds interacting with the mineral was detected. The controls (sterile culture medium) showed the presence of iron hydroxides complexes and elemental sulfur, product of chemical leaching and the initial phase of a passivation process. With this study we demonstrated that the leaching process can be monitored by electrochemical methods, where the process of bacterial-mineral interaction could be followed, and also simultaneously identifying the initial processes of passivation. Our work can be useful for the development of a device for the in situ monitoring of biomining processes.

scholarly journals CONTROL OF CELL PROGRESSION THROUGH THE MITOTIC CYCLE BY CARBOHYDRATE PROVISION

1968 ◽  
Vol 37 (3) ◽  
pp. 773-780 ◽  
Author(s):  
Jack Van't Hof
Keyword(s):  
Stationary Phase ◽  
Culture Medium ◽  
Mitotic Cycle ◽  
Root Meristem ◽  
Tritiated Thymidine ◽  
Energy Requirement ◽  
Sterile Culture ◽  
Cell Progression ◽  
Pea Roots ◽  
G1 Cells

A stationary phase in the root meristem of excised pea roots was established by prolonged carbohydrate deprivation in sterile culture medium. When the stationary phase had been established, cells that had collected in the G1 period of the mitotic cycle were induced to enter the S stage by subjection to relatively short intervals of carbohydrate provision (sucrose spurts). Progression and cycle location of the G1 cells induced to enter S were measured with tritiated thymidine and radioautography. The results indicated that the number of G1 cells induced to enter S increased directly with the spurt duration and that cells could be positioned and retained in the S and/or G2 periods by varying the duration of the spurt. The data support the hypothesis that S and maybe M stages have a relatively larger dependence on carbohydrate availability, and presumably a greater energy requirement, than G1 and G2.

Exacerbation of Murine Respiratory Mycoplasmosis by Sialodacryoadenitis Virus Infection in Gnotobiotic F344 Rats

1987 ◽  
Vol 24 (5) ◽  
pp. 392-399 ◽  
Author(s):  
T. R. Schoeb ◽  
J. R. Lindsey
Keyword(s):  
Virus Infection ◽  
Culture Medium ◽  
Lung Lesion ◽  
Mycoplasma Pulmonis ◽  
Experimental Conditions ◽  
Sterile Culture ◽  
Naturally Occurring ◽  
Colony Forming Units ◽  
Nasal Passages ◽  
F344 Rats

To test the hypothesis that sialodacryoadenitis virus infection could exacerbate respiratory mycoplasmosis in rats, four groups of 40 7- to 9-week-old gnotobiotic F344/N rats were given two intranasal inoculations 7 days apart: Mycoplasma pulmonis, then sialodacryoadenitis virus; M. pulmonis followed by sterile culture medium; medium initially, then virus; or two doses of medium. Immediately and 3, 5, 10, and 20 days after the second inoculation, the nasal passages, middle ears, larynges, tracheas, lungs, and salivary and lacrimal glands of four rats from each group were prepared for histologic examination, and the respiratory organs from four other rats were collected for quantitative culture of M. pulmonis and sialodacryoadenitis virus. To test statistically the effect of virus infection on mycoplasmosis lesions, we determined indices of the severity of respiratory tract lesions by subjective scoring. In rats given both organisms, indices of nasal and tracheal lesions were significantly ( P < 0.05) greater at 3 days and after than in rats given M. pulmonis alone, and middle ear, laryngeal, and lung lesion indices were significantly greater at 5 days and after. Rats given both mycoplasma and virus had significantly more mycoplasmal colony-forming units in the nasal passages at 3 days and after, and in the larynges, tracheas, and lungs at 10 and 20 days, than rats given only mycoplasma. These results show that sialodacryoadenitis virus infection can exacerbate respiratory mycoplasmosis in rats under experimental conditions; therefore, the virus probably also contributes to expression of naturally occurring mycoplasmosis.

Effect of Some Metabolic Inhibitors on Vinblastine-Induced Ribosomal-Granular Material Complexes

1971 ◽  
Vol 29 ◽  
pp. 548-549
Author(s):  
Awtar Krishan ◽  
Dora Hsu
Keyword(s):  
Granular Material ◽  
Rna Synthesis ◽  
Culture Medium ◽  
Actinomycin D ◽  
Metabolic Inhibitors ◽  
Protein And Rna Synthesis ◽  
Apparent Reduction ◽  
Plant Alkaloids ◽  
In Cells

Cells exposed to antitumor plant alkaloids, vinblastine and vincristine sulfate have large proteinacious crystals and complexes of ribosomes, helical polyribosomes and electron-dense granular material (ribosomal complexes) in their cytoplasm, Binding of H3-colchicine by the in vivo crystals shows that they contain microtubular proteins. Association of ribosomal complexes with the crystals suggests that these structures may be interrelated.In the present study cultured human leukemic lymphoblasts (CCRF-CEM), were incubated with protein and RNA-synthesis inhibitors, p. fluorophenylalanine, puromycin, cycloheximide or actinomycin-D before the addition of crystal-inducing doses of vinblastine to the culture medium. None of these compounds could completely prevent the formation of the ribosomal complexes or the crystals. However, in cells pre-incubated with puromycin, cycloheximide, or actinomycin-D, a reduction in the number and size of the ribosomal complexes was seen. Large helical polyribosomes were absent in the ribosomal complexes of cells treated with puromycin, while in cells exposed to cycloheximide, there was an apparent reduction in the number of ribosomes associated with the ribosomal complexes (Fig. 2).

Structural aspects of osmoregulation in porphyra

1978 ◽  
Vol 36 (2) ◽  
pp. 412-413
Author(s):  
C. Wiencke ◽  
A. Lauchli
Keyword(s):  
Culture Medium ◽  
Point Of View ◽  
Chemical Fixation ◽  
Cellular Organization ◽  
Osmotic Adaptation ◽  
Osmotic Balance ◽  
Activity Of Enzymes ◽  
Osmotic Agents ◽  
Vacuolar System ◽  
Structural Aspects

Osmoregulatory mechanisms in algae were investigated mainly from a physiological point of view (KAUSS 1977, HELLEBUST 1976). In Porphyra two osmotic agents, i. e. floridoside/isofloridoside (KAUSS 1968) and certain ions, such as K+ and Na+(EPPLEY et al. 1960) are considered for osmotic balance. Accumulations of ions (particularly Na+) in the cytoplasm during osmotic adaptation is improbable, because the activity of enzymes is generally inhibited by high ionic concentrations (FLOWERS et al. 1977).The cellular organization of Porphyra was studied with special emphasis on the development of the vacuolar system under different hyperosmotic conditions. Porphyra was cultivated at various strengths of the culture medium ASP 12 (PROVASOLI 1961) ranging from normal to 6 times concentrated (6x) culture medium. Por electron microscopy freeze fracturing was used (specimens fixed in 2% glutaraldehyde and incubated in 30% glycerol, preparation in a BALZERS BA 360 M apparatus), because chemical fixation gave poor results.

The significance of SEM in the diagnosis of haematopoietic malignancies

1978 ◽  
Vol 36 (2) ◽  
pp. 314-315
Author(s):  
Etienne de Harven ◽  
Nina Lampen
Keyword(s):  
Room Temperature ◽  
Culture Medium ◽  
Cell Attachment ◽  
Ethanol Dehydration ◽  
Moist Chamber ◽  
Efficient Alternative ◽  
Mononuclear Leucocytes ◽  
Fast Quenching ◽  
Freeze Dryer ◽  
Scanning Electron

Samples of heparinized blood, or bone marrow aspirates, or cell suspensions prepared from biopsied tissues (nodes, spleen, etc. ) are routinely prepared, after Ficoll-Hypaque concentration of the mononuclear leucocytes, for scanning electron microscopy. One drop of the cell suspension is placed in a moist chamber on a poly-l-lysine pretreated plastic coverslip (Mazia et al., J. Cell Biol. 66:198-199, 1975) and fifteen minutes allowed for cell attachment. Fixation, started in 2. 5% glutaraldehyde in culture medium at room temperature for 30 minutes, is continued in the same fixative at 4°C overnight or longer. Ethanol dehydration is immediately followed by drying at the critical point of CO2 or of Freon 13. An efficient alternative method for ethanol dehydrated cells is to dry the cells at low temperature (-75°C) under vacuum (10-2 Torr) for 30 minutes in an Edwards-Pearse freeze-dryer (de Harven et al., SEM/IITRI/1977, 519-524). This is preceded by fast quenching in supercooled ethanol (between -90 and -100°C).

Effects of carbamylcholine on chick embryo aggregate retina cell cultures

1988 ◽  
Vol 46 ◽  
pp. 350-351
Author(s):  
Glenn M. Cohen ◽  
Radharaman Ray
Keyword(s):  
Cell Cultures ◽  
Single Cells ◽  
Retinal Cell ◽  
Cell Aggregates ◽  
High Concentration ◽  
In Ovo ◽  
Sterile Culture ◽  
Retinal Tissue ◽  
Synaptic Junctions ◽  
And Control

Retinal,cell aggregates develop in culture in a pattern similar to the in ovo retina, forming neurites first and then synapses. In the present study, we continuously exposed chick retinal cell aggregates to a high concentration (1 mM) of carbamylcholine (carbachol), an acetylcholine (ACh) analog that resists hydrolysis by acetylcholinesterase (AChE). This situation is similar to organophosphorus anticholinesterase poisoning in which the ACh level is elevated at synaptic junctions due to inhibition of AChE, Our objective was to determine whether continuous carbachol exposure either damaged cholino- ceptive neurites, cell bodies, and synaptic elements of the aggregates or influenced (hastened or retarded) their development.The retinal tissue was isolated aseptically from 11 day embryonic White Leghorn chicks and then enzymatically (trypsin) and mechanically (trituration) dissociated into single cells. After washing the cells by repeated suspension and low (about 200 x G) centrifugation twice, aggregate cell cultures (about l0 cells/culture) were initiated in 1.5 ml medium (BME, GIBCO) in 35 mm sterile culture dishes and maintained as experimental (containing 10-3 M carbachol) and control specimens.

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