The use of charcoal in in vitro culture – A review

Activated charcoal is commonly used in tissue culture media. Its addition to culture medium may promote or inhibit in vitro growth, depending on species and tissues used. The effects of activated charcoal may be attributed to establishing a darkened environment; adsorption of undesirable/inhibitory substances; adsorption of growth regulators and other organic compounds, or the release of growth promoting substances present in or adsorbed by activated charcoal.     

Selection of Lactobacillus acidophilus strains for use in “acidophilus products”

Recent studies by DNA-DNA hybridization revealed that strains now designated as L. acidophilus, can be divided into several groups and only one group should be classified as L. acidophilus. We studied several phenotypic characteristics in representative strains from the six DNA-homology groups of L. acidophilus. No group specific pattern was observed among the strains for fermentation of eight carbohydrates, growth at 15 and 45°C, resistance to 0.2% oxgall, lysis by lysozyme or sensitivity to 17 antibiotics. However, some differences among groups were observed in -galactosidase (-gal) activity and surface layer (s-layer) protein. Strains in B1 do not have a s-layer or -gal while B2 strains also lack a s-layer but do possess -gal. All strains in groups A1, A2, A3 and A4, capable of growing in lactose, have -gal activity and also have a s-layer composed of protein subunits of different molecular weights (MW). Strains in A1 homology group have a s-layer with 46 Kd protein subunits while strains in other A groups have s-layer protein subunits that varied in MW within each group. On the basis of these two traits several isolates of unknown homology groups have been tentatively placed in A1, B1 or B2 groups. L. acidophilus from A1 group showed strain variation in -gal specific activity and rate of acid production and growth. For use in dietary adjuncts, L. acidophilus strains should be selected for these three and other desirable traits. They should be maintained and grown in media containing lactose.     

On the use of “life history theory” in evolutionary psychology

We critically review the use of the term “life history theory” in recent publications on evolutionary psychology, focusing on how the idea of a fast-slow continuum is deployed in that literature. We raise four issues:First, concerning plasticity, should we expect the effects of plasticity on the developmental response of a trait to mirror the effects of selection on the mean of that trait? We conclude that we should not. Do only plastic responses to harsh or unpredictable environments accelerate maturation, or are there plausible alternatives, such as nutrition? In many situations better nutrition is a plausible alternative.Second, how should we conceive of the harshness of an environment? It has several important dimensions. It could mean an increase in the mean mortality rate, a decrease in the mean growth rate or fertility rate, or increases in the variances of any of those rates. Our judgement of harshness will also be affected by the distribution of such effects across patches in space and through generations in time. The combination and distribution of effects make important differences to predictions.Third, where did the fast-slow idea come from, and how much does it explain? It was initially detected in comparisons across higher taxonomic levels, whose relevance to variation among individuals is unclear and where it fails to explain much of the variation.Fourth, what sorts of processes could generate the fast-slow pattern? Here we expand on insights mentioned earlier in passing to make clear how spatial population structure and class effects generate alternative predictions.We conclude with some thoughts on the nature of theories and research strategies and on how one might respond to empirical puzzles.     

Polymer coated liposomes for use in the oral cavity – a study of the in vitro toxicity,effect on cell permeability and interaction with mucin

In this study we investigated the in vitro toxicity, impact on cell permeability and mucoadhesive potential of polymer-coated liposomes intended for use in the oral cavity. A TR146 cell line was used as a model. The overall aim was to end up with a selection of safe polymer coated liposomes with promising mucoadhesive properties for drug delivery to the oral cavity. The following polymers were tested: chitosan, low-methoxylated pectin (LM-pectin), high-methoxylated pectin (HM-pectin), amidated pectin (AM-pectin), Eudragit, poly(N-isopropylacrylamide-co-methacrylic acid) (p(NIPAAM-co-MAA)), hydrophobically modified hydroxyethyl cellulose (HM-HEC), and hydrophobically modified ethyl hydroxyethyl cellulose (HM-EHEC). With chitosan as an exception, all the systems exhibited no significant effect on cell viability and permeability at the considered concentrations. Additionally, all the formulations showed to a varying degree an interaction with mucin (BSM type I-S); the positively charged formulations exhibited the strongest interaction, while the negatively and neutrally charged formulations displayed a moderate or low interaction. The ability to interact with mucin makes all the liposomal formulations promising for oromucosal administration. Although the chitosan-coated liposomes affected the cell viability, this formulation also influenced the cell permeability, which makes it an interesting candidate for systemic drug delivery from the oral cavity.     

Is there any scientific evidence for the use of glucosamine in the management of human osteoarthritis?

Glucosamine in its acetylated form is a natural constituent of some glycosaminoglycans (for example, hyaluronic acid and keratan sulfate) in the proteoglycans found in articular cartilage, intervertebral disc and synovial fluid. Glucosamine can be extracted and stabilized by chemical modification and used as a drug or a nutraceutical. It has been approved for the treatment of osteoarthritis (OA) in Europe to promote cartilage and joint health and is sold over the counter as a dietary supplement in the United States. Various formulations of glucosamine have been tested, including glucosamine sulfate and glucosamine hydrochloride. In vitro and in vivo studies have uncovered glucosamine's mechanisms of action on articular tissues (cartilage, synovial membrane and subchondral bone) and justified its efficacy by demonstrating structure-modifying and anti-inflammatory effects at high concentrations. However, results from clinical trials have raised many concerns. Pharmacokinetic studies have shown that glucosamine is easily absorbed, but the current treatment doses (for example, 1,500 mg/day) barely reach the required therapeutic concentration in plasma and tissue. The symptomatic effect size of glucosamine varies greatly depending on the formulation used and the quality of clinical trials. Importantly, the effect size reduces when evidence is accumulated chronologically and evidence for the structure-modifying effects of glucosamine are sparse. Hence, glucosamine was at first recommended by EULAR and OARSI for the management of knee pain and structure improvement in OA patients, but not in the most recent NICE guidelines. Consequently, the published recommendations for the management of OA require revision. Glucosamine is generally safe and although there are concerns about potential allergic and salt-related side effects of some formulations, no major adverse events have been reported so far. This paper examines all the in vitro and in vivo evidence for the mechanism of action of glucosamine as well as reviews the results of clinical trials. The pharmacokinetics, side effects and differences observed with different formulations of glucosamine and combination therapies are also considered. Finally, the importance of study design and criteria of evaluation are highlighted as new compounds represent new interesting options for the management of OA.     

Sertoli cells of adult rats “in vitro”

Summary A cell line obtained from isolated seminiferous tubules of adult rat testis has been studied in vitro over a period of 35 days.Light and electron microscopic studies performed from hour 2 to the end of culture have shown the presence of a monomorphic cell population. After 5–6 days of culture the cells formed a monolayer. The cytoplasm of the cells contained numerous lipid bodies and produced numerous projections. The nucleus showed several indentations and one or more nucleoli. From the 9th to the 15th day of culture the cells developed a large amount of endoplasmic reticulum, Golgi apparatus and aggregates of electron dense granules. From the 20th to 40th day the cell cultures progressively degenerated.Immunochemical analysis of the culture medium revealed the presence of estradiol-17, which reached its maximum production rate from the 8th day to the 18th day of culture. Corresponding to cell involution estradiol concentration underwent a rapid decrease.On the basis of morphological and biochemical data the cells could be considered Sertoli cells.This work was supported by Grants n. 74.00155.04 and n. 75.01224.04 from the Consiglio Nazionale delle Ricerche (C.N.R.), Rome, Italy, and by Istituto di Ricerca F. Angelini, Rome, ItalyPart of this work was presented at the 10th Italian Congress of Electron Microscopy. Ostuni 1–4 October 1975The excellent technical assistance of Miss Laura Vassallo, Daniela Venturini and Mr. Massimo Rosati and Mario Termine is deeply appreciated     

Experiences with the use of a starter culture in the fermentation of maize for ‘kenkey’ production in Ghana

Controlled fermentation of maize was carried out using six strains of Lactobacillus fermentum and one strain of yeast, Saccharomyces cerevisiae, isolated from traditionally fermented maize dough as starter cultures for inoculum enrichement. The fermentations were monitored by pH, acidity, microbiological analysis and taste panel evaluation of two products, kenkey and koko, prepared from the fermented doughs. The strains of L. fermentum used as starter culture dominated the microflora during fermentation and in most inoculated doughs the required pH was attained by 24 h instead of 48 h of dough fermentation. Higher contents of lactic acid bacteria and yeasts were observed in inoculated doughs at the initial stages of fermentation but the spontaneously fermented doughs attained similar lactic acid bacteria and yeasts counts by 24 h of dough fermentation. The organoleptic quality of kenkey and koko prepared from doughs fermented with starter culture for 48 h was not significantly different from the traditional products. Kenkey prepared from doughs fermented for 24 h with starter culture were found to be unacceptable by the taste panel although similarly produced koko was acceptable.The authors are with the Food Research Institute, Council for Scientific and Industrial Research, P.O Box M 20. Accra, Ghana.     

A procedure for the Cherenkov counting of high energy β and γ emitting radionuclides in coloured plant extracts

Summary Elimination of count rate variations caused by the absorption of Cherenkov radiation by pigments in coloured solutions was achieved by placing these solutions in opaque walled cylinders immersed in colourless liquids contained in standard counting vials. Good counting efficiencies for a range of and emitting radionuclides were obtained by selecting colourless liquids with high refractive index.     

The use of β-propiolactone for the sterilization of heat-labile materials

A short literature survey on chemical sterilization with -propiolactone is given. The auto-inactivatio 1 of this compound in aqueous solution appears to be one of its main advantages.Time-kill studies have been carried out with bacterial cells and spores, and with fungal spores. The compatibility of BPL with textiles and plastics was also studied to some extent. It is concluded that heat-sensitive materials can be sterilized with a 1.0% aqueous solution of BPL within one hour at room temperature. The compatibility of BPL with the materials studied does not appear to offer serious problems.     

In vitro metabolic engineering for the production of α-ketoglutarate

α-Ketoglutarate (aKG) represents a central intermediate of cell metabolism. It is used for medical treatments and as a chemical building block. Enzymatic cascade reactions have the potential to sustainably synthesize this natural product. Here we report a systems biocatalysis approach for an in vitro reaction set-up to produce aKG from glucuronate using the oxidative pathway of uronic acids. Because of two dehydrations, a decarboxylation, and reaction conditions favoring oxidation, the pathway is driven thermodynamically towards complete product formation. The five enzymes (including one for cofactor recycling) were first investigated individually to define optimal reaction conditions for the cascade reaction. Then, the kinetic parameters were determined under these conditions and the inhibitory effects of substrate, intermediates, and product were evaluated. As cofactor supply is critical for the cascade reaction, various set-ups were tested: increasing concentrations of the recycling enzyme, different initial NAD⁺ concentrations, as well as the use of a bubble reactor for faster oxygen diffusion. Finally, we were able to convert 10 g L⁻¹ glucuronate with 92% yield of aKG within 5 h. The maximum productivity of 2.8 g L⁻¹ h⁻¹ is the second highest reported in the biotechnological synthesis of aKG.     

Importance of functional classification in the use of carabids for the environmental risk assessment of the GE crops and other agricultural practices

Carabids(Coleoptera:Carabidae)seem to be suitable bioindicalors of the environmental impacts of novel agrotechnologies,including deployment of the genetically engineered(GE)crops.In this article,we describe our effort to employ carabids in the environmental risk assessment(ERA).GE maize MON88017,its near-isogenic hybrid nontreated or treated with the soil insccticide chlorpyrifos,and two reference hybrids were used to compare three different ways how to utilize carabids in ERA.The analysis of abundance of all captured carabids or of the most abundant carabid specics did not disclose any differences between the treatments.The analysis based on the categories of functional traits revealed distinct fecatures of some treatments and proved suitable for ERA because it permitted field data transportability in spite of different species compositions.Our results indicate that GE maize has no detrimental environmental effecl,On the other hand,we found significant trends toward lower abundance and lower species number(including analysis of all carabid species together)in plots treated with the insecticide,and some tendencies to higher abundance and higher species number in plots sown with the reference hybrid PR38N86.Using functional group indicators alows identification of unintended changes in ecological functions of agroecosystem and comparability across geographics.We recommend data evaluation at the level of the categories of functional traits in ERA of GE crops and other agricultural practices.     

Development of an in vitro system for screening the ligands of a membrane glycoprotein CD36

It has well been known that human and rodents exhibit a preference for fats. This suggests the existence of an orosensory system responsible for the detection of dietary fats. A plasma membrane glycoprotein CD36, besides the role in the uptake of long-chain fatty acids (LCFAs) as well as oxidized low-density lipoprotein (OxLDL) in a variety of cells, has been postulated to be a candidate fat taste receptor on the tongue. Therefore, molecules that bind with CD36 to cause intracellular signaling but have fewer calories could be substitutes for dietary fats. In the present study, we developed an in vitro system for the screening of CD36 ligands using Chinese hamster ovary-K1 cells (CHO-K1) stably transfected with human or mouse CD36. When incubated with OxLDL labeled with fluorescence dye, the fluorescence was much higher in the transfected CHO-K1 cells than in non-transfected CHO-K1 cells. Incubation of the transfected cells with OxLDL caused a rapid phosphorylation of extracellular signal regulated kinase, and the degree was significantly higher compared with that in non-transfected CHO-K1 cells. The expression system using CHO-K1 cells could be a convenient tool to screen the novel ligands of CD36.     

A review on the “in vitro” culture of freshwater mussels (Unionoida)

Many Unionoida are considered to be extinct, endangered, or of special concern. These bivalves have complex life cycle stages that limit successful culture. In nature, the larvae (glochidia) of these bivalves must successfully parasitize a host (mainly fish) in order to metamorphose into juveniles. The two artificial methods used to obtain juvenile freshwater mussels in laboratory are either by induced attachment to host fish or by in vitro culture of glochidia. This article is focused on the in vitro method that represents a novel and alternative process to fish infestation, offering the ability to obtain larger numbers of juveniles without the need for host fishes and reducing the overall costs of propagation. In vitro culture requires a medium which fulfills the nutritional needs of each glochidia species and avoids microbial contamination. Recently, this methodology has presented excellent results with survival and transformation rates up to 94% using host fish plasma. High efficiencies on growth, and survival rates (84%) of juvenile freshwater bivalve Hyriopsis myersiana (Lea, 1856) up to 120 days were obtained when reared in adequate recirculating aquacultural systems using a very specific diet. More research is still needed to demonstrate successful propagation, mainly concerning the media nutritional composition to increase glochidia transformation and juvenile quality.     

Elucidating the mode of action for thiophene-based organic D-π-A sensitizers for use in photodynamic therapy

Photodynamic therapy (PDT) is a non-invasive, selective, and cost-effective cancer therapy. The development of readily accessible templates that allow rapid structural modification for further improvement of PDT remains important. We previously reported thiophene-based organic D-π-A sensitizers consisted of an electron-donating (D) moiety, a π-conjugated bridge (π) moiety, and an electron-accepting (A) moiety as valuable templates for a photosensitizer that can be used in PDT. Our preliminary structure-activity relationship study revealed that the structure of the A moiety significantly influences its phototoxicity. In this study, we evaluated the photoabsorptive, cellular uptake, and photo-oxidizing abilities of D-π-A sensitizers that contained different A moieties. The level of phototoxicity of the D-π-A sensitizers was rationalized by considering those three abilities. In addition, we observed the ability of amphiphilic sensitizers containing either a carboxylic acid or an amide in an A moiety to form aggregates that penetrate cells mainly via endocytosis.