Partial antigenic characterization of different potato virus Y NTN strain isolates

Eight isolates of potato virus Y NTN strain (PVY-NTN) of different origin were studied by means of monoclonal antibodies (MAbs) in non-competitive and competitive enzyme-linked immunosorbent assay (ELISA), and by immunoblot analysis of the viral coat protein (CP). As the MAbs reacted with the denatured viral CP, their epitopes must be continuous. The ELISA data demonstrate that the epitopes are topologically different. The epitopes may be located on the N-terminal part of CP as showed its partial amino acid sequencing and the immunoblot analysis.     

Downregulation of plasma membrane expression/cytoplasmic accumulation of beta-catenin predicts shortened survival in non-small cell lung cancer. A clinicopathologic study of 100 cases

The E-cadherin-catenin complex proteins function in cell-cell adhesion and have been reported to be dysregulated in various human malignancies. Beta catenin is a cytoplasmic protein that associates with tyrosine kinase receptors and modulates cytoskeletal dynamics. It also plays a role in the Wnt signaling pathway. During neoplastic transformation, the phosphorylation of beta-catenin causes a loss of intercellular adhesions resulting in increased tumor cell motility and invasiveness. Tissue sections from 100 cases of non-small cell lung cancer (NSCLC) were immunostained with a monoclonal beta-catenin antibody. There were 47 squamous cell carcinomas (SCC) and 53 adenocarcinomas (AC) in the study group. Plasma membrane/cytoplasmic beta-catenin immunoreactivity was scored for intensity and distribution and correlated with tumor stage, grade and survival. Plasma membrane/cytoplasmic immunoreactivity for beta-catenin protein was observed in 71 (71%) of 100 NSCLC. 44 (94%) of 47 SCC and 27 (51%) of 53 AC expressed beta catenin. On univariate analysis, loss of beta catenin expression correlated with high tumor stage (p = 0.025), large tumor size (p = 0.02) and decreased patient survival (p = 0.04). The loss of beta catenin expression associated with high grade NSCLC reached near significance (p = 0.07). On multivariate analysis, the loss of beta catenin expression independently predicted shortened overall patient survival in NSCLC (p = 0.05). Beta catenin expression loss is associated with advanced tumor stage and is an independent predictor of shortened patient survival in NSCLC.     

Partial purification and characterization of anhydrotetracycline oxygenase of Streptomyces aureofaciens

Anhydrotetracycline oxygenase was purified both by affinity chromatography and by hydrophobic interaction chromatography. Molecular weight of anhydrotetracycline oxygenase was determined to be 115,000 by Sephadex G-200 gel filtration. Using preparative isoelectric focusing the isoelectric point of the enzyme was estimated to be 5.3. The enzyme showed a sensitivity to thiol-specific inhibitors. During the hydrophobic interaction purification step, the activity dropped considerably. Reactivation occurred when a heat treated crude extract was added to the reaction mixture.     

Desensitization to substance P following intrathecal injection

Summary The intrathecal injection of substance P (SP) (2.5–15 g) has been shown to produce hyperalgesia in the rat tail flick test. Repeated injection of SP (7.5 or 15 g) or pretreatment with two of these doses produces desensitization to this hyperalgesic response. Desensitization is doserelated with respect to degree and duration. This phenomenon is relatively specific because the hyperalgesic response to methysergide, a serotonin receptor antagonist, is unaffected, while that produced by phentolamine, an adrenergic receptor antagonist, is much less affected than that of SP. Pretreatment with a desensitizing regimen of SP potentiates the antinociceptive effect of morphine and baclofen when they are tested immediately after the regimen but if a 30 min delay is permitted, an inhibition of their effects is observed. These results support the notion that the spinal antinociceptive effect of morphine and baclofen is due to an interaction with SP mechanisms in the spinal cord, the nature of which may be more complex than is presently understood. Desensitization produces no change in baseline responsiveness in the tail flick test. This suggests that the hyperalgesic response to SP is due either to an action at a site other than the primary afferent synapse, or if it is at this site either compensatory mechanisms occur or SP is not the primary determinant of tail flick latency but may play a modulatory role.     

Qualitative and quantitative isotachophoretic analysis of some quaternary isoquinoline alkaloids1,2

A rapid isotachophoretic separation of benzo[ C]phenanthridine alkaloids from CHELIDONIUM MAJUS L. is described. The method allows the determination of sanguinarine and chelerythrine in the presence of other isoquinoline alkaloids in crude alkaloids extracts.     

Enrichment techniques and trace analysis with microbore columns in liquid chromatography

The advantages of microbore columns for trace analysis by liquid chromatography are identified, with reference to on-column enrichment techniques performed on analytical micro-columns. The selectivity and high sensitivity of the amperometric detector are utilized in combination with a microbore column for a number of pharmaceutical and bioanalytical analyses, including phenothiazines, parabens, sulphonamides, catecholamines, tetracyclines, vitamins, amino acids and dipeptides.     

Vitamin C—Sources,Physiological Role,Kinetics, Deficiency,Use, Toxicity,and Determination

Vitamin C (L-ascorbic acid) has been known as an antioxidant for most people. However, its physiological role is much larger and encompasses very different processes ranging from facilitation of iron absorption through involvement in hormones and carnitine synthesis for important roles in epigenetic processes. Contrarily, high doses act as a pro-oxidant than an anti-oxidant. This may also be the reason why plasma levels are meticulously regulated on the level of absorption and excretion in the kidney. Interestingly, most cells contain vitamin C in millimolar concentrations, which is much higher than its plasma concentrations, and compared to other vitamins. The role of vitamin C is well demonstrated by miscellaneous symptoms of its absence—scurvy. The only clinically well-documented indication for vitamin C is scurvy. The effects of vitamin C administration on cancer, cardiovascular diseases, and infections are rather minor or even debatable in the general population. Vitamin C is relatively safe, but caution should be given to the administration of high doses, which can cause overt side effects in some susceptible patients (e.g., oxalate renal stones). Lastly, analytical methods for its determination with advantages and pitfalls are also discussed in this review.