IgG production kinetics in serum free media

Summary A murine hybridoma (455) was cultured in four different serum free media formulations, and a newborn calf serum supplemented medium was used as a basis of comparison. The serum supplemented medium supports a higher cell growth rate and results in a higher IgG titer. However, the antibody secretion rate on a per cell basis is higher in the serum free media, indicating that serum could be inhibitory to antibody secretion. The results identify the possibility of a least eliminating serum during the monoclonal antibody production phase.     

Operation and pressure distribution of immobilized cell hollow fiber bioreactors

It has been cited in the literature on hollow fiber systems that pressure gradients persist, and the transmembrane flux of the hollow fiber system is dependent on the pattern of the pressure gradients. The pattern can be used to its advantage in immobilized enzyme systems. However, with immobilized living cell systems, the pressure gradients lead to a nonuniform environment within the hollow fiber cartridge and not necessarily favorable results. This article provides pertinent pressure-drop data on hollow fiber cartridges which are in flow configurations typical of immobilized cell culture work. The results illuminate operational problems that may arise in the culture of either anchorage dependent or independent cells. Possible solutions with crossflow systems are suggested.     

Characterization of archaeal symbionts of sponges from the coral reef ecosystems of the Gulf of Mannar,Southeast coast of India

Sponges accommodate a diverse group of microorganisms with varied metabolic capabilities. The bacterial associates of sponges are widely studied while our understanding of archaeal counterparts is scanty. In the present study, we report the archaeal associates of two sponges, Pseudoceratina purpurea (NCBI barcode: KX454492) and Cinachyra sp. (NCBI barcode: KX454495), found in the coral reef ecosystems of Gulf of Mannar, India. Archaea in the water column was predominated by members of class Halobacteria of Phylum Euryarchaeota (97%) followed by a minor fraction (3%) of Nitrosopumilus sp. of phylum Thaumarchaeota. Interestingly, Thaumarchaeota was identified as the sole archaeal population associated with the two sponges studied, among which Nitrosopumilus sp. occuppied 80 and 100% of the sequences in the clone library of P. purpurea and Cinachyra sp. respectively. Other archaea found in the P. purpurea were Nitrososphaera (10%) and unclassified ones (10%). The study identified Nitrosopumilus sp. as a unique symbiotic archaeon of sponges, P. purpurea and Cinachyra sp. The existence of host driven factors in selecting specific associates from a diverse group of archaea in the environment may need further investigations.     

Chemical composition of volatile oil from Cinnamomum zeylanicum buds

The hydro-distilled volatile oil of the Cinnamomum zeylanicum (C. zeylanicum) buds was analyzed using GC and GC-MS for the first time. Thirty-four compounds representing approximately 98% of the oil was characterized. It consists of terpene hydrocarbons (78%) and oxygenated terpenoids (9%). alpha-Bergamotene (27.38%) and alpha-copaene (23.05%) are found to be the major compounds. A comparison of the chemical composition of the oil was made with that of flowers and fruits.     

Oxygen-Glucose Deprivation and Reoxygenation as an In Vitro Ischemia-Reperfusion Injury Model for Studying Blood-Brain Barrier Dysfunction

Ischemia-Reperfusion (IR) injury is known to contribute significantly to the morbidity and mortality associated with ischemic strokes. Ischemic cerebrovascular accidents account for 80% of all strokes. A common cause of IR injury is the rapid inflow of fluids following an acute/chronic occlusion of blood, nutrients, oxygen to the tissue triggering the formation of free radicals.Ischemic stroke is followed by blood-brain barrier (BBB) dysfunction and vasogenic brain edema. Structurally, tight junctions (TJs) between the endothelial cells play an important role in maintaining the integrity of the blood-brain barrier (BBB). IR injury is an early secondary injury leading to a non-specific, inflammatory response. Oxidative and metabolic stress following inflammation triggers secondary brain damage including BBB permeability and disruption of tight junction (TJ) integrity.Our protocol presents an in vitro example of oxygen-glucose deprivation and reoxygenation (OGD-R) on rat brain endothelial cell TJ integrity and stress fiber formation. Currently, several experimental in vivo models are used to study the effects of IR injury; however they have several limitations, such as the technical challenges in performing surgeries, gene dependent molecular influences and difficulty in studying mechanistic relationships. However, in vitro models may aid in overcoming many of those limitations. The presented protocol can be used to study the various molecular mechanisms and mechanistic relationships to provide potential therapeutic strategies. However, the results of in vitro studies may differ from standard in vivo studies and should be interpreted with caution.