440 research outputs found
A Simplified Model of Glycoprotein Production within Cell Culture
Complex biological products, such as those used to treat various forms of cancer, are typically produced by mammalian cells in bioreactors. The most important class of such biological medicines is proteins. These typically bind to sugars (glycans) in a process known as glycosylation, creating glycoproteins, which are more stable and effective medicines. The glycans are large polymers that are formed by a long sequence of enzyme catalysed reactions. This sequence is not always completed, thus leading to a heterogeneous glycoprotein distribution. A better comprehension of this distribution could lead to more efficient production of high quality drugs. To understand how the manufacturing process can affect the extent of glycosylation of protein, a non-linear ODE model of glycoprotein production is developed which describes the bioreactor configuration as well as the protein production and glycosylation reactions within the cell. The entire system evolves eventually to a stable steady state. The earlier evolution is critical however, as the amount of product produced and its quality varies over time. The model is considered as two coupled systems: the bioreactor submodel and the glycosylation submodel. To investigate the early time evolution within the bioreactor submodel, analytical and numerical properties are derived using matched asymptotic expansions and a finite difference scheme for a range of initial conditions. This leads to qualitatively different regimes for aglycosylated protein production, which affect the glycosylation submodel. The discrete glycoprotein distribution is approximated as continuous and written as a first-order PDE, with good agreement between the discrete and continuous models. The PDE is found to admit shocks, but the existence of these shocks is dependent on the early time evolution within the bioreactor submodel and leads to higher levels of glycosylation at early time. This suggests that changing the bioreactor configuration can lead to higher quality product at certain times
Pearl oyster farming and pearl production
Natural pearls were the oldest gems known
to mankind. Long before man discovered the
diamond and other precious stones, pearls were
considered to be the first precious gem. The Vedas
of India, the Bible and the Quran make several
reference of pearls as objects of adoration and
worship. The natural pearls of the Gulf of Mannar
and the Persian Gulf enjoyed very good reputation
in the world trade from the time immemorial. The
Gulf of Mannar pearls are famous throughout the
world as 'Orient Pearls'
Experimental culture of the Indian oyster, Crassostrea madrasensis (Preston) at Ashtamudi lake, Kerala
The edible oyster,
Crassostrea Madrasensis, (P reston)
occurs attached to hard substrates
in the intertidal and subtidal regions
of the coastal areas. Oyster
meat is a highly esteemed seafood
and aquaculture of oysters is widely
prevalent and well established in
many temperate countri
рдорд╛рдирд╕реВрди рдХреЗ рджреМрд░рд╛рди рдмреБрдХрд╛рдиреАрд░ рдРрдВрдЪреЛрд╡реА рдХрд╛ рдЙрдкрддрдЯ рдкреНрд░рд╡рд╛рд╕
рдХреГрдкрдпрд╛ рдкреВрд░рд╛ рд▓реЗрдЦрд╛ рдкрдв
The pearl oysters
An account of the pearl oyster resources with a brief note on
biology, collection methods, seed production and conservation and
management in the Indian subcontinent is dealt with in this paper.
Both in the Gulf of Kutch and the Gulf of Mannar, the population
does not show improvement. Conservation and management of this
important resource in the light of the present R&D carried out by
the CMFRI is discussed. Enhancement of the wild stock through the
production of genetically improved seed in the hatchery and ranching
them to selected beds and close monitoring of the physico-chemical
and biological factors over a period of time is suggested. Farming
of oysters on the natural beds can enhance the pearl quality
and may form a breeding reserve
Manual on Pearl Oyster Seed Production, Farming and Pearl Culture
The Central Marine Fisheries Research Institute has developed expertise
on various marine fisheries and mariculture technologies over the past
several years. Based on this expertise the Institute has been offering regular
training courses to officials from State Governments, Universities, ICAR
Institutes, Krishi Vigyan Kendras, training institutions, industry and progressive
farmers on subjects like marine prawn hatchery, prawn farming,
pearl oyster hatchery, pearl oyster culture, pearl culture, edible oyster
hatchery, edible oyster farming, seaweed culture and utilisation, SCUBA
diving, estimation of marine fish production and stock assessment. The
Trainers' Training Centre (TTC) of the CMFRI, Cochin, established in the
year 1983, has so far conducted 83 such trainings for 590 personnel from the
various maritime states including Pondicherry, Lakshadweep and the
Andaman & Nicobar Islands
Pearl production in relation to the graft tissue in the pearl oyster Pinctada fucata (Gould)
This reports the results of study on which region of the mantle gives good quality pearls and also higher production rate. The mantle tissue from 4 areas namely anterior (a),posterior (b), middle (c), and central (d)regions were used. This study showed that the middle region of mantle when used as graft tissue resulted in not only high percentage of pearl formation (50.28%) but also, the marketable pearls (A, B and C - groups) accounted for 77.53% of the total pearls produced
Neonatal septicemia: bacteriological profile in a tertiary level hospital in South India
Background: Early onset bacterial sepsis remains a major cause of neonatal morbidity and death. The choice of antibiotic for an infant with sepsis depends on the predominant bacterial pathogens and the antibiotic susceptibility profiles for the microorganisms causing disease in a particular geographic region. The purpose of this study was to analyze the bacteriological profile and antibiotic sensitivity pattern of neonatal septicemia in our neonatal unit.Methods: A descriptive cross sectional study carried was out at the NICU of a tertiary level hospital in South India for a period of one year.Results: Clinically suspected septicemia comprised 18.14% of total NICU admissions. Organism was isolated by blood culture in 14.9% of cases. The most common organisms causing septicemia were Coagulase negative Staphylococci, Klebsiella and Staphylococcus aureus. Gram positive isolates were most sensitive to Vancomycin (100%) while the gram negative isolates were most sensitive to Amikacin. Resistance to Crystalline Penicillin, Ampicillin┬а and 3rd generation cephalosporins was high.Conclusions: The most common organism isolated in septicemia was Coagulase negative staphylococcus in our NICU. Gram positive isolates were most sensitive to Vancomycin (100%) while the gram negative isolates were most sensitive to Amikacin. High resistance to commonly used antibiotics is worrisome. There should be a constant surveillance of the common microbes and their sensitivity pattern in each NICU and the antibiotic protocols should be periodically reviewed. Rational use of antibiotics and preventive measures like hand washing is the need of the hour
Larval and juvenile rearing of black-lip pearl oyster, Pinctada margaritifera (Linnaeus)
The black-lip pearl oyster, Pinctada margaritifera (Linnaeus), has been cultured in the experimental shellfish hatchery at Tuticorin, India. The flagellates Isochrysis galbana and Pavlova lutheri were used independently as larval food at a concentration of 5 cells/╬╝l up to day 5 and the ration was doubled thereafter until spat setting. The initial larval density was 1/ml. Straighthinge veliger stage (75├Ч60 ╬╝m) was reached in 20 h, umbo stage (140├Ч130 ╬╝m) on day 12, pediveliger (220├Ч210 ╬╝m) on day 20 and plantigrade (260├Ч240 ╬╝m) on day 23, and spat of 350├Ч300 ╬╝m appeared on day 28. I. galbana promoted faster growth and early spat setting as compared to P. lutheri. The modal component of the larval population showed an average growth of 10.98 ╬╝m/day. A total of 6.3% of the initial larval population metamorphosed as spat. Juveniles cultured in the laboratory showed a growth rate of 0.09 mm/day. On transplantation to the culture raft in the farm, growth rate increased to 0.4 mm/day. The juveniles suffered heavy mortality after 4 months. It remains to be tested whether P. margaritifera juveniles would have a greater chance of survival in oceanic island conditions, as the natural distribution of the species in India is confined to the Andaman and Nicobar Islands
Modulator Dynamics Shape the Design Space for Stepwise-Elution Simulated Moving Bed Chromatographic Separations
For proteins and other biological macromolecules, SMB chromatography is best operated non-isocratically. However, traditional modes of non-isocratic SMB operation generate significant mobile-phase modulator dynamics. The mechanisms by which these modulator dynamics affect a separation's success, and thus frame the design space, have yet to be explained quantitatively. Here, the dynamics of the modulator (e.g., salts in ion exchange and hydrophobic interaction chromatography) are explicitly accounted for. This leads to the elucidation of two new design constraints, presented as dimensionless numbers, which quantify the effects of the modulator phenomena and thus predict the success of a non-isocratic SMB separation. Consequently, these two new design constraints re-define the SMB design space. Computational and experimental studies at the boundaries of this design space corroborate the theoretical predictions. The design of efficient and robust operating conditions through use of the new design space is also demonstrated
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