Formulation of Ocular In Situ Gels with Lithuanian Royal Jelly and Their Biopharmaceutical Evaluation In Vitro

Royal jelly is a natural substance produced by worker bees that possesses a variety of biological activities, including antioxidant, anti-inflammatory, antibacterial, and protective. Although fresh royal jelly is kept at low temperatures, to increase its stability, it needs to be incorporated into pharmaceutical formulations, such as in situ gels. The aim of this study was to formulate in situ ocular gels containing Lithuanian royal jelly for topical corneal use in order to increase the retention time of the formulation on the ocular surface and bioavailability. Gels were evaluated for physicochemical characteristics (pH, rheological properties, refractive index) and in vitro drug release measuring the amount of 10-hydroxy-2-decenoic acid (10-HDA). An ocular irritation test and cell viability tests were performed using the SIRC (Statens Seruminstitut Rabbit Cornea) cell culture line. Results indicated that all the in situ gels were within an acceptable pH and refractive index range close to corneal properties. Rheology studies have shown that the gelation temperature varies between 25 and 32 °C, depending on the amount of poloxamers. The release studies have shown that the release of 10-HDA from in situ gels is more sustained than royal jelly suspension. All gel formulations were non-irritant according to the short-time exposure test (STE) using the SIRC cell culture line, and long-term cell viability studies indicated that the formulations used in small concentrations did not induce cell death. Prepared in situ gels containing royal jelly have potential for ocular drug delivery, and they may improve the bioavailability, stability of royal jelly, and formation of non-irritant ocular formulations.

STUDY OF THE EFFECT OF BIOLOGICALLY ACTIVE SUBSTANCES ON THE REPRO-DUCTION OF THE TRANSPLANTED CELL CULTURE LINE

The present study was carried out with take into account the high biological activity of bi-opolymers, in particular chitin and chitosan for animal cell cultures in vivo and in vitro. The aim of the study was investigating the effect of apiphytoextract on the growth and reproduction of trans-planted Taurus-1 cell lines after their recriopreservation for long-term storage in the liquid nitrogen. The use of apiphytoextract as part of the culture medium in the cultivation of hydrated cell lines allowed the use of the method of cell recriopreservation for reproduction of viruses, which are used for vaccine production.

Genetic diversity of dengue virus serotypes 1 and 2 in the State of Paraná, Brazil, based on a fragment of the capsid/premembrane junction region

INTRODUCTION: The precise identification of the genetic variants of the dengue virus is important to understand its dispersion and virulence patterns and to identify the strains responsible for epidemic outbreaks. This study investigated the genetic variants of the capsid-premembrane junction region fragment in the dengue virus serotypes 1 and 2 (DENV1-2). METHODS: Samples from 11 municipalities in the State of Paraná, Brazil, were provided by the Central Laboratory of Paraná. They were isolated from the cell culture line C6/36 (Aedes albopictus) and were positive for indirect immunofluorescence. Ribonucleic acid (RNA) extracted from these samples was submitted to the reverse transcription polymerase chain reaction (RT-PCR) and nested PCR. RESULTS: RT-PCR revealed that 4 of the samples were co-infected with both serotypes. The isolated DENV-1 sequences were 95-100% similar to the sequences of other serotype 1 strains deposited in GenBank. Similarly, the isolated DENV-2 sequences were 98-100% similar to other serotype 2 sequences in GenBank. According to our neighbor-joining tree, all strains obtained in this study belonged to genotype V of DENV-1. The DENV-2 strains, by contrast, belonged to the American/Asian genotypes. CONCLUSIONS: The monitoring of circulating strains is an important tool to detect the migration of virus subtypes involved in dengue epidemics.

A sequence related to rice Pong transposable element displays transcriptional activation by in vitro culture and reveals somaclonal variations in maize

Miniature inverted-repeat transposable elements (MITEs) are nonautonomous elements that are abundant in plant genomes. The rice MITE mPing was shown to be mobilized by anther culture, and the associated transposon Pong was shown to transpose actively in an Oryza sativa ‘indica’ rice cell-culture line. We have identified 3 sequences in maize named ZmTPAPong-like 1, 2, and 3 that displayed homology with the transposase of Pong. Here, we show that these sequences are differentially expressed during the in vitro androgenetic process in maize. We also demonstrate that the ZmTPAPong-like 1 and 3 sequences reveal somaclonal variations among plants regenerated from the calli of a doubled haploid line. These data suggest that the ZmTPAPong-like sequences could form part of a Zea mays element related to the rice Pong element. The possible activation of this newly discovered element under stress conditions is discussed.

Effect of Local Anesthetic on Neuronal Cytoplasmic Calcium and Plasma Membrane Lysis (Necrosis) in a Cell Culture Model

Background To investigate the mechanism by which rare cases of spinal local anesthetic (LA) neurotoxicity occur, we have tested the hypotheses that LAs elevate cytoplasmic calcium (Ca2+(cyt)), that this is associated with a neurotoxic effect, and that lidocaine and bupivacaine differ in their neurotoxicity. Methods Neurons of the ND7 cell culture line, derived from dorsal root ganglion, were loaded with fura-2 and analyzed by digitized video fluorescence microscopy during 60 min LA exposure, allowing determination of Ca2+(cyt) and time of necrotic cell death (plasma membrane lysis) at the single neuron level. Results Lidocaine 0.1% and bupivacaine 0.025% caused minimal changes in Ca. Lidocaine 0.5-5% and bupivacaine 0.125-0.625% caused an early, small (less than threefold), concentration-dependent increase in Ca2+(cyt) that was transient and returned to near baseline within 10 min. Lidocaine 2.5% and 5% then caused a sustained, greater than ten-fold increase in Ca2+(cyt) and death in some neurons during the 60 min exposure period. Pretreatment with thapsigargin eliminated the initial transient increase in Ca2+(cyt), consistent with endoplasmic reticulum (ER) as its source, and increased neuronal death with 5% lidocaine, suggesting that lidocaine neurotoxicity can be increased by failure of ER to take up elevated Ca2+(cyt). The later sustained increase in Ca2+(cyt) seen with 2.5 and 5% lidocaine was prevented in Ca2+ -free medium, and restored when Ca2+ was added back to the buffer in the presence of lidocaine, suggesting that higher concentrations of lidocaine increase influx of Ca2+ through the plasma membrane. Conclusions In this model, lidocaine greater than 2.5% elevates Ca2+(cyt) to toxic levels. Bupivacaine and lower concentrations of lidocaine transiently alter Ca2+(cyt) homeostasis for several minutes, but without an immediate neurotoxic effect within 60 min.