Monday, 10 August 2015

What is Russian Doll Disease ? It's Leishmaniasis !



Russian doll disease is a virus inside a parasite inside a fly




Russian doll disease is a virus inside a parasite inside a fly
Red blood cell, complete with Leishmania parasite (Image: Eye of Science/SPL)

It’s a Russian doll of a tropical disease. Leishmaniasis, a disease that infects 12 million people worldwide, is passed to humans by sandflies infected with the Leishmania parasite.
Now it seems that in some species of the parasite, a virus hiding inside is silently helping it subvert treatment.
Leishmaniasis is a common problem in Latin America, South Asia and parts of Africa. Depending on the form the disease takes and the species of parasite, it either attacks the skin, mucous linings of the nose and mouth, or the internal organs. It’s not easy to treat.

“Treatment failure is a major challenge for doctors and researchers, says Jean-Claude Dujardin from the Institute of Tropical Medicine in Antwerp, Belgium.
Depending on the drug and the region, treatment failure rates vary, says Dujardin. In Latin America, for example, two out of five people relapse after treatment, but this can rise to 70 per cent in parts of South Asia where another species of Leishmania circulates. The most obvious explanation is that the parasite has become resistant or that people aren’t taking the drugs properly.

Infected parasite

But in Latin America at least, it looks like there’s an alternative explanation. A virus that infects the parasite is known to make the disease more severe in mice. It now seems the same applies in people.

“The parasite is already infected by the virus and it is this package that gets transferred to the sandfly,” says Dujardin, part of an international collaboration that hunted down the virus in people infected with the L. braziliensis parasite in the Amazon basin of Bolivia and Peru. Of the people whose parasites were infected with the virus, 53 per cent of them had relapsed after drug treatment. Only 24 per cent of the people whose parasites were virus-free did so.
Similar results were seen in people infected with L. guyanensis, another parasite species common in the area. There was no link between treatment success and the parasite’s resistance to the drugs the patient was given.
“You need to imagine the system like a Russian doll,” says Dujardin. The parasite multiplies within the human host cell, and then the virus lurking within it wakes up and begins interacting with the host cell, he says.
“Leishmania alone, without the virus, is already known to subvert the immune response; it seems that the virus adds another layer of subversion, leading to treatment failure,” says Dujardin.

In good company

In some ways it’s not surprising that a virus can infect a parasite. It’s often said that parasitism is the most common way of life – with more than half of all animal species on the planet living off another in some way.
But Kevin Lafferty, an ecologist at the University of California, Santa Barbara, says that although viruses are known to infect bacteria and parasites, instances of a virus infecting a parasite that in turn infects another host are not very common. “This is a fascinating piece of detective work with important implications for human health.”
However, Jorge Alvar at the Drugs for Neglected Diseases Initiative in Switzerland, cautions that we still don’t how the virus affects the evolution of the parasite, or how it ultimately impacts the patient.
But, in theory, the virus gives us an added drug target, he says. “In this case a patient could be treated with either anti-Leishmania drugs or anti-virals, or both.
Similar viruses have been found in other parasites, for example, in the diarrhoea-causing Giardia and Cryptosporidium, and in Trichomonas vaginalis that causes a sexually transmitted infection. Surveys of their prevalence could help us better understand the effect of viral infection of parasites and could play a role in how we treat these parasitic diseases, says Dujardin.
Journal reference: Journal of Infectious Diseases, DOI: 10.1093/infdis/jiv355 (L. braziliensis); DOI: 10.1093/infdis/jiv354 (L. guyanensis)


If you want to read the complete article then you may visit the (actual source) direct link ---> https://www.newscientist.com/article/dn28020-russian-doll-disease-is-a-virus-inside-a-parasite-inside-a-fly/

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How if We don’t need bodies?

What if … We don’t need bodies?

Uploading our minds onto computers could be the future. But cutting ties with our animal roots would raise ethical questions for which we don't yet have answers
What if … We don't need bodies?
Is anybody in there? (Image: Skizzomat)

MINDS result from bodies, but that link can be compromised. If I severed my spinal cord at the neck, I’d get no inputs from most of my body, says Michael Graziano, a neuroscientist at Princeton University. “But I’m still a person, I still have experience, I can still think.”
What if we could separate mind from body entirely? Many now believe that we will transfer our minds on to computers, whether in a matter of decades or hundreds of years. “I would say that it’s not only possible, it’s inevitable,” says Graziano.
What would life as an upload be like? We’d still need outside stimulation. Cut off entirely, a brain would suffer sensory deprivation, says Anders Sandberg at the University of Oxford. “It’s going to fall asleep, then hallucinate and probably gently go mad.


If you want to read the complete article then you may visit the (actual source) direct link ---> https://www.newscientist.com/article/mg22730330-600-what-if-we-dont-need-bodies/

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Maintenanceof Sterility in Animal Tissue Culture
 
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Tuesday, 14 July 2015

Bioinformatics vs. Computational biology

Defining the terms bioinformatics and computational biology is not necessarily an
easy task, as evidenced by multiple definitions available over the web. In
the past few years, as the areas have grown, a greater confusion into these two
terms has prevailed. For some, the terms bioinformatics and computational
biology have become completely interchangeable terms, while for others, there is
a great distinction.

Bioinformatics and computational biology follows the NIH definitions listed below: 

Bioinformatics: Research, development, or application of computational tools and approaches for expanding the use of biological, medical, behavioral or health data, including those to acquire, store, organize, archive, analyze, or visualize such data. 

Computational Biology: The development and application of data-analytical and theoretical
methods, mathematical modeling and computational simulation techniques to the study of
biological, behavioral, and social systems.


Computational biology and bioinformatics are multidisciplinary fields, involving
researchers from different areas of specialty, including (but in no means limited
to) statistics, computer science, physics, biochemistry, genetics, molecular
biology and mathematics. The goal of these two fields is as follows:
•  Bioinformatics: Typically refers to the field concerned with the collection
and storage of biological information. All matters concerned with biological
databases are considered bioinformatics.
•  Computational biology: Refers to the aspect of developing algorithms
and statistical models necessary to analyze biological data through the aid
of computers. 


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Thursday, 2 July 2015

Role of carbon dioxide in animal cell culture



Carbon dioxide (CO2) and Bicarbonate

Carbon dioxide in the gas phase dissolves in the medium, establishes equilibrium with HCO3− ions, and lowers the pH. Because dissolved CO2, HCO3−, and pH are all interrelated, it is difficult to determine the major direct effect of CO2.
The atmospheric CO2 tension will regulate the concentration of dissolved CO2 directly, as a function of temperature.
This regulation in turn produces H2CO3, which dissociates according to the reaction
(1)
H2O+CO2 ⇔ H2CO3 ⇔ H+ + HCO3−
HCO3− has a fairly low dissociation constant with most of the available cat-ions so it tends to re-associate, leaving the medium acid. The net result of increasing atmospheric CO2 is to depress the pH, so the effect of elevated CO2tension is neutralized by increasing the bicarbonate concentration:
(2)
NaHCO3 ⇔ Na+ + HCO3−
The increased HCO3− concentration pushes equation (1) to the left until equilibrium is reached at pH 7.4. If another alkali (e.g., NaOH) is used instead, the net result is the same:
(3)
NaOH + H2CO3 ⇔ NaHCO3 + H2O ⇔ Na+ + HCO3− + H2O
Intermediate values of CO2 and HCO3− may be used, provided that the concentration of both is varied proportionately. Because many media are made up in acid solution and may incorporate a buffer, it is difficult to predict how much bicarbonate to use when other alkali may also end up as bicarbonate, as in equation (3). When preparing a new medium for the first time, add the specified amount of bicarbonate and then sufficient 1 N NaOH such that the medium equilibrates to the desired pH after incubation in a Petri dish at 37°C, in the correct CO2 concentration, overnight. When dealing with a medium that is already at working strength, vary the amount of HCO3− to suit the gas phase, and leave the medium overnight to equilibrate at 37°C. Each medium has a recommended bicarbonate concentration and CO2 tension for achieving the correct pH and osmolality, but minor variations will occur in different methods of preparation.
With the introduction of Good’s buffers (e.g., HEPES, Tricine) into tissue culture, there was some speculation that, as CO2 was no longer necessary to stabilize the pH, it could be omitted. This proved to be untrue, at least for a large number of cell types, particularly at low cell concentrations. Although 20 mM HEPES can control pH within the physiological range, the absence of atmospheric CO2 allows equation (1) to move to the left, eventually eliminating dissolved CO2, and ultimately HCO3−, from the medium. This chain of events appears to limit cell growth, although whether the cells require the dissolved CO2 or the HCO3− (or both) is not clear. Recommended HCO3−, CO2, and HEPES concentrations are given in.
The inclusion of pyruvate in the medium enables cells to increase their endogenous production of CO2, making them independent of exogenous CO2, as well as HCO3−. Leibovitz L15 medium contains a higher concentration of sodium pyruvate (550 mg/L) but lacks NaHCO3 and does not require CO2 in the gas phase. Buffering is achieved via the relatively high amino acid concentrations. Because it does not require CO2, L15 is sometimes recommended for the transportation of tissue samples. Sodium β-glycerophosphate can also be used to buffer autoclavable media lacking CO2 and HCO3−, and Invitrogen markets a CO2− independent medium. If the elimination of CO2 is important for cost saving, convenience, or other reasons, it might be worth considering one of these formulations, but only after appropriate testing.
In sum, cultures in open vessels need to be incubated in an atmosphere of CO2, the concentration of which is in equilibrium with the sodium bicarbonate in the medium. Cells at moderately high concentrations (≥1×105 cells/mL) and grown in sealed flasks need not have CO2 added to the gas phase, provided that the bicarbonate concentration is kept low (∼4mM), particularly if the cells are high acid producers. At low cell concentrations, however (e.g., during cloning), and with some primary cultures, it is necessary to add CO2 to the gas phase of sealed flasks. When venting is required, to allow either the equilibration of CO2 or its escape in high acid producers, it is necessary to leave the cap slack or to use a CO2− permeable cap.

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Did you read these few relative topics ?
Development of media for animal tissue culture 
Selecting the correct medium and serum in Animal Biotechnology
Serum – as a growth medium in animal tissue culture
Complete Media - Animal tissue culture
Balanced Salt Solution in Animal Tissue Culture
Animal Biotechnology - Tissue Culture and Cell Culture 
Maintenance of Sterility in Animal Tissue Culture Labs
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Friday, 26 June 2015

Selecting the correct medium and serum in Animal Biotechnology



Selecting the medium and serum in animal Biotechnology

Most of the media described in our previous post- Serum – as a growth medium in animal tissue culture were developed to support particular cell lines or conditions. Many were developed with L929 mouse fibroblasts or HeLa cervical carcinoma cells, and Ham’s F12 was designed for Chinese hamster ovary (CHO) cells; all now have more general applications and have become classic formulations. Among them, data from suppliers would indicate that RPMI 1640, DMEM, and MEM are the most popular, making up about 75% of sales. Other formulations seldom account for more than 5% of the total; most constitute 2–3%, although blended DMEM/F12 comes closer, with over 4%. Eagle’s Minimal Essential Medium (MEM) was developed from Eagle’s Basal Medium (BME) by increasing the range and concentration of the constituents. For many years, Eagle’s MEM had the most general use of all media. Dulbecco’s modification of BME (DMEM) was developed for mouse fibroblasts for transformation and virus propagation studies. It has twice the amino acid concentrations of MEM, has four times the vitamin concentrations, and uses twice the HCO3 −and CO2 concentrations to achieve better buffering. α-MEM has additional amino acids and vitamins, as well as nucleosides and lipoic acid; it has been used for a wide range of cell types, including hematopoietic cells. Ham’s F12 was developed to clone CHO cells in low-serum medium; it is also used widely, particularly for clonogenic assays and primary culture. CMRL 1066, M199, and Waymouth’s media were all developed to grow L929 cells serum-free but have been used alone or in combination with other media, such as DMEM or F12, for a variety of more demanding conditions. RPMI1640 and Fischer’s media were developed for lymphoid cells—Fischer’s specifically for L5178Y lymphoma, which has a high folate requirement. RPMI 1640 in particular has quite widespread use, often for attached cells, despite being designed for suspension culture and lacking calcium. L15 medium was developed specifically to provide buffering in the absence of HCO3 − and CO2. It is often used as a transport and primary culture medium for this reason, but its value was diminished by the introduction of HEPES and the demonstration that HCO3 − and CO2 are often essential for optimal cell growth, regardless of the requirement for buffering.
Information regarding the selection of the appropriate medium for a given type of cell is usually available in the literature in articles on the origin of the cell line or the culture of similar cells. Information may also be obtained from the source of the cells. Cell banks, such as ATCC and ECACC, provide information on media used for currently available cell lines, and data sheets can be accessed from their websites. Failing this, the choice is made either empirically or by comparative testing of several media, as for selection of serum.
Many continuous cell lines (e.g., HeLa, L929, BHK21), primary cultures of human, rodent, and avian fibroblasts, and cell lines derived from them can be maintained on a relatively simple medium such as Eagle’s MEM, supplemented with calf serum. More complex media may be required when a specialized function is being expressed or when cells are sub-cultured at low seeding density (<1×103 /mL), as in cloning. Frequently, the more demanding culture conditions that require complex media also require foetal bovine serum rather than calf or horse serum, unless the formulation specifically allows for the omission of serum.
If information is not available, a simple cell growth experiment with commercially available media and multiwell plates can be carried out in about two weeks. Assaying for clonal growth and measuring the expression of specialized functions may narrow the choice further [you may soon find the protocol for this cell growth experiment in our upcoming posts, or just mail us at BiotechExplorer@gmail.com].
Autoclavable media are available from commercial suppliers (you may search it on web). They are simple to prepare from powder and are suitable for many continuous cell strains. They may need to be supplemented with glutamine for most cells and usually require serum.

Note a simple trick: The cost of serum should be calculated on the basis of the volume of the medium when cell yield is not important, but if the objective is to produce large quantities of cells, one should calculate serum costs on a per-cell basis. Thus, if a culture grows to 1×106 /mL in serum A and 2×106 mL in serum B, serum B becomes the less expensive by a factor of two, given that product formation or some other specialized function is the same.
If foetal bovine serum seems essential, try mixing it with calf serum. This may allow you to reduce the concentration of the more expensive foetal serum. If you can, leave out serum altogether, or reduce the concentration, and use a serum-free formulation.

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Did you read these few relative topics ?
Development of media for animal tissue culture
Serum – as a growth medium in animal tissue culture
Complete Media - Animal tissue culture
Balanced Salt Solution in Animal Tissue Culture
Animal Biotechnology - Tissue Culture and Cell Culture 
Maintenance of Sterility in Animal Tissue Culture Labs

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