Real-time technique for conversion of skin temperature into skin blood flow: human skin as a low-pass filter for thermal waves

Monitoring of skin blood flow oscillations related with mechanical activity of vessels is a very useful modality during diagnosis of peripheral hemodynamic disorders. In this study, we developed a new model and technique for real-time conversion of skin temperature into skin blood flow oscillations, and vice versa. The technique is based on the analogy between the thermal properties of the human skin and electrical properties of the special low-pass filter. Analytical and approximated impulse response functions for the low- and high-pass filters are presented. The general algorithm for the reversible conversion of temperature into blood flow is described. The proposed technique was verified using simulated or experimental data of cold stress, deep inspiratory gasp, and post-occlusive reactive hyperaemia tests. The implementation of the described technique will enable to turn a temperature sensor into a blood flow sensor.     

Fluorescence Adherence Inhibition Assay: A Novel Functional Assessment of Blocking Virus Attachment by Vaccine-Induced Antibodies

Neutralizing antibodies induced by vaccination or natural infection play a critically important role in protection against the viral diseases. In general, neutralization of the viral infection occurs via two major pathways: pre- and post-attachment modes, the first being the most important for such infections as influenza and polio, the latter being significant for filoviruses. Neutralizing capacity of antibodies is typically evaluated by virus neutralization assays that assess reduction of viral infectivity to the target cells in the presence of functional antibodies. Plaque reduction neutralization test, microneutralization and immunofluorescent assays are often used as gold standard virus neutralization assays. However, these methods are associated with several important prerequisites such as use of live virus requiring safety precautions, tedious evaluation procedure and long assessment time. Hence, there is a need for a robust, inexpensive high throughput functional assay that can be performed rapidly using inactivated virus, without extensive safety precautions. Herein, we report a novel high throughput Fluorescence Adherence Inhibition assay (fADI) using inactivated virus labeled with fluorescent secondary antibodies virus and Vero cells or erythrocytes as targets. It requires only few hours to assess pre-attachment neutralizing capacity of donor sera. fADI assay was tested successfully on donors immunized with polio, yellow fever and influenza vaccines. To further simplify and improve the throughput of the assay, we have developed a mathematical approach for calculating the 50% titers from a single sample dilution, without the need to analyze multi-point titration curves. Assessment of pre- and post-vaccination human sera from subjects immunized with IPOL^®, YF-VAX^® and 2013–2014 Fluzone^® vaccines demonstrated high efficiency of the assay. The results correlated very well with microneutralization assay performed independently by the FDA Center of Biologics Evaluation and Research, with plaque reduction neutralization test performed by Focus Diagnostics, and with hemaglutination inhibition assay performed in-house at Sanofi Pasteur. Taken together, fADI assay appears to be a useful high throughput functional immunoassay for assessment of antibody-related neutralization of the viral infections for which pre-attachment neutralization pathway is predominant, such as polio, influenza, yellow fever and dengue.     

Comparing Arachnids in Rovno Amber with the Baltic and Bitterfeld Deposits

Paleontological Journal - So far 107 families of chelicerates are known from the Rovno amber, which is comparable with those known from the Baltic amber (144 families) and three times more than in...     

New Pyrimidine Cyclonucleosides with Hydrogenated Aglycones: Synthesis and X-Ray Structures

Abstract

Acid catalysed transformations of (6S)-6,5′-anhydro-6-hydroxy-1-(2′,3′-O-isopropylidene-β-D-ribofuranosyl)hexahydropyrimidine-2-thione are studied. (6R)-6,2′-anhydro-6-hydroxy-1-(α-D-ribofuranosyl)hexahydropyrimidine-2-thione was formed as a thermodynamically stable product. Two intermediates, (6S)-6,5′-anhydro-6-hydroxy-1-(β-D-ribofuranosyl)hexahydropyrimidine-2-thione and 6-hydroxy-1-(D-ribosyl)hexahydropyrimidine-2-thione and products of cleavage of glycosidic bond were identified in the reaction mixtures. Results of X-ray structural determination of the synthesised nucleosides are presented.     

Prognostic value of non-MHC-restricted killer cell activity in lung cancer

The prognostic value of peripheral blood non-MHC-restricted cytotoxicity against the myeloid leukaemic line K562 in lung cancer patients was studied. At the time of diagnosis and before operation, 57 patients with lung cancer were tested for cytotoxicity and subsequently followed for up to 4 years. In addition, 145 lung cancer patients, 30 patients with non-neoplastic lung diseases and 76 healthy donors were tested for cytotoxicity without the follow-up, in order to correlate the stage of lung cancer and the growth rate of tumours to the level of non-MHC-restricted cytotoxicity. On average, lung cancer patients had similar non-MHC-restricted cytotoxicity to the controls. However, patients with stage II–IV diseases showed an impaired activity, stages III and IV differing significantly from the controls. This result shows that the decline in natural killer (NK) activity is associated with tumour burden. Patients with slowly growing neoplasms had stronger cytotoxic activity than patients with fast or moderately progressing disease. In the follow-up study, the whole material of 57 patients showed only a slight correlation between cytotoxicity and survival: 42% of the patients with strong activity survived for more than 2.5 years, whereas 6% of the patients with weak activity did so. In stage I patients there was no correlation between cytotoxicity and survival, nor was there a correlation in patients with stages II–IV of the disease. Hence, in our group of patients the determination of cytotoxicity preoperatively yielded no prognostic information beyound that already available from staging. However, those stage II–IV patients that survived for 1 year or more after the diagnosis and cytotoxicity tests, showed a significant correlation between cytotoxicity and survival.