Modulation of drug-induced cytotoxicity by a bispecific monoclonal antibody that recognizes the epidermal growth factor receptor and doxorubicin

A hybrid hybridoma secreting a bispecific hybrid mAb (bsmAb), which recognizes both the epidermal growth factor receptor (EGF-R) and the drug doxorubicin, was produced by somatic hybridization of two hybridomas. The bsmAb obtained was able to retarget doxorubicin cytotoxicity in vitro specifically on EGF-R-positive cells exerting at the same time an antidotal effect on cells that did not overexpress the EGF-R. Distribution studies in mice indicate that the bsmAb selectively delivers the drug to tumour cells and modifies doxorubicin biodistribution with a statistically significant decrease of drug concentration in the intestine, which is the main target of early anthracycline toxicity. In keeping with this finding is the remarkable antidotal activity exerted by bsmAb in mice treated with doxorubiein, which is proved by retardation in loss of body weight and mortality. The effectiveness on tumour growth of the mAb followed by the administration of doxorubicin appears to be equal to that of the drug alone; however, the bsmAb exerts a remarkable antidotal activity.     

Biogeneration of 2-phenylethanol and 2-phenylethylacetate important aroma components

Summary 2-Phenylethanol and 2-phenylethylacetate important aroma components are obtained in substantial amounts whenHansenula anomala CBS 110 andKloeckera saturnus CBS 5761 are grown with L-phenylalanine as sole nitrogen source. Up to 2 g/L of mixtures of alcohol and ester are obtained. While in the first microorganism the alcohol predominates, in the second the acetate is formed almost exclusively. Experiments with 1-¹³C-d-Glucose show complete incorporation of the label into the methyl group of the acetate.     

Reactive Oxygen Species Produced by a Photodynamic Effect Induced Calcium Signal in Neurons and Astrocytes

Photodynamic therapy (PDT) leads to production of reactive oxygen species (ROS) and cell destruction due to oxidative stress. We used photodynamic effect of photosensitizer radachlorin to unravel the effect of photo-induced oxidative stress on the calcium signal and lipid peroxidation in primary culture of cortical neurons and astrocytes using live cell imaging. We have found that irradiation in presence of 200 nM of radachlorin induces calcium signal in primary neurons and astrocytes. Photo-induced neuronal calcium signal depends on internal calcium stores as it was still observed in calcium-free medium and could be blocked by depletion of endoplasmic reticulum (ER) stores with inhibitor of sarco-endoplasmic reticulum Ca²⁺ ATPase (SERCA) thapsigargin. Both inhibitors of phospholipase C activity U73122 and water-soluble analogue of vitamin E Trolox suppressed calcium response activated by PDT. We have also observed that the photodynamic effect of radachlorin induces lipid peroxidation in neurons and astrocytes. This data demonstrate that lipid peroxidation induced by PDT in neurons and astrocytes leads to activation of phospholipase C that results in production of inositol 1,4,5-trisphosphate (IP3).     

Decreased Electroconvulsive Shock-Induced Diacylglycerols and Free Fatty Acid Accumulation in the Rat Brain by Ginkgo biloba Extract (EGb 761): Selective Effect in Hippocampus as Compared with Cerebral Cortex

Abstract: The effect of Ginkgo biloba extract (EGb 761) treatment (100 mg/kg/day, per os, for 14 days) on electroconvulsive shock (ECS)-induced accumulation of free fatty acids (FFA) and diacylglycerols (DAG) was analyzed in rat cerebral cortex and hippocampus. EGb 761 reduced the FFA pool size by 33% and increased the DAG pool by 36% in the hippocampus. These endogenous lipids were unaffected in cerebral cortex. During the tonic seizure (10 s after ECS) the fast accumulation of FFA, mainly 20:4, was similar in sham- and EGb 761 -treated rats, in both the cerebral cortex and hippocampus. However, further accumulation of free 18:0 and 20:4, observed in the hippocampus of sham-treated rats during clonic seizures (30 s to 2 min after ECS), did not occur in EGb 761-treated animals. The rise in DAG content triggered in the cortex and hippocampus by ECS was delayed by EGb 761 treatment from 10 s to 1 min, when values similar to those in sham animals were attained. Moreover, in the hippocampus the size of the total DAG pool was decreased by 19% during the tonic seizure. At later times, DAG content showed a faster decrease in EGb 761-treated rats. By 2 min levels of all DAG acyl groups decreased to values significantly lower than in sham animals in both cortex and hippocampus. This study shows that EGb 761 treatment affects, with high selectivity, lipid metabolism and lipid-derived second messenger release and removal in the hippocampus, while affecting to a lesser extent the cerebral cortex.     

Settlement of bivalve spat on artificial collectors in Eyjafjordur, North Iceland

The seasonal pattern of bivalve spat settlement in Eyjafjordur, North Iceland, was investigated using artificial collectors of monofilament netting over 14 months (March 1998–January 2000) at 5, 10 and 15 m depth. SCUBA divers replaced the collectors at 4-weekly intervals. Twelve bivalve species settled on the collectors but only Mytilus edulis and Hiatella arctica were present throughout the year; they were the most abundant bivalve taxa. Of the remaining species, only Chlamys islandica, Heteranomia spp., Arctica islandica, Serripes groenlandicus and Mya spp. were sufficiently abundant to enable statistical analysis. All settled in late summer and autumn. Peak settlement of M. edulis, in September, consisted mainly of primary settlers (0.25–0.5 mm) although secondary settlers (>0.5 mm) were present in all samples. Mytilus edulis settled mostly at 5 m depth, especially larger individuals, possibly reflecting stronger currents at shallower depth and the proximity of mussel beds in the intertidal zone. Primary (<1 mm) and secondary H. arctica settlers (>1 mm) were present in most months, with the former being most numerous in September, 1999; settlement was equally abundant at 5 and 10 m depth. Primary settlement of C. islandica and S. groenlandicus occurred in autumn (mainly in September), and secondary settlers were very scarce and only seen in winter. Arctica islandica, Heteranomia spp. and Mya spp. settled mainly in September 1999 at 10 m depth, except for A. islandica, which was more numerous in August.     

Optimising Immunogenicity with Viral Vectors: Mixing MVA and HAdV-5 Expressing the Mycobacterial Antigen Ag85A in a Single Injection

The Bacillus Calmette - Guerin (BCG) vaccine provides a critical but limited defense against Mycobacterium tuberculosis (M.tb). More than 60 years after the widespread introduction of BCG, there is an urgent need for a better vaccine. A large body of pre-clinical research continues to support ongoing clinical trials to assess whether viral vectors expressing M.tb antigens that are shared by BCG and M.tb, can be used alongside BCG to enhance protection. A major focus involves using multiple unique viral vectors to limit anti-vector immunity and thereby enhance responses to the insert antigen delivered. The successful introduction of viral vector vaccines to target M.tb and other pathogens will be reliant on reducing the costs when using multiple vectors and inhibiting the development of unwanted anti-vector responses that interfere with the response to insert antigen. This study examines methods to reduce the logistical costs of vaccination by mixing different viral vectors that share the same insert antigen in one vaccine; and whether combining different viral vectors reduces anti-vector immunity to improve immunogenicity to the insert antigen. Here we show that a homologous prime-boost regimen with a mixture of MVA (Modified Vaccinia virus Ankara) and Ad5 (human adenovirus type 5) vectors both expressing Ag85A in a single vaccine preparation is able to reduce anti-vector immunity, compared with a homologous prime-boost regimen with either vector alone. However, the level of immunogenicity induced by the homologous mixture remained comparable to that induced with single viral vectors and was less immunogenic than a heterologous Ad5 prime-MVA-boost regimen. These findings advance the understanding of how anti-vector immunity maybe reduced in viral vector vaccination regimens. Furthermore, an insight is provided to the impact on vaccine immunogenicity from altering vaccination methods to reduce the logistical demands of using separate vaccine preparations in the field.     

Metabolomic analysis of sex specific metabolites in gonads of the mussel,Mytilus edulis

Marine mussels have been used as sentinel organisms to monitor exposure to a variety of chemical contaminants, including endocrine disrupting chemicals, in the aquatic environment. Although they are an important species for use in ecotoxicology investigations, information on their reproductive physiology and biochemistry is fragmentary. Mass spectrometry-based profiling techniques are increasingly being used to study how the metabolome of an organism changes as a result of tissue differentiation, disease or in response to environmental stressors. In this study, ultraperformance liquid chromatography–time-of-flight-mass spectrometry (UPLC–TOFMS) was used to investigate sex specific differences in the mussel metabolome in order to further investigate the reproductive physiology of this species. Using this method, a comparison of female and male mantle tissues containing mature gonad, revealed significant differences in glycerophosphatidylcholine (PC) and lysophosphatidylcholine (LPC) metabolites. A number of other unidentified metabolites, including those putatively identified as conjugated sterols, were also differentially expressed between male and female mantle/gonadal tissue.