Using Peripheral Venous Pressure Waveforms to Predict Key Hemodynamic Parameters

Analysis of peripheral venous pressure (PVP) waveforms is a novel method of monitoring intravascular volume. Two cohorts were used to study the hemodynamics change of the body state and its influence on the PVP using (1) dehydration setting with infants suffering from pyloric stenosis and (2) hemorrhage setting during a craniosynostosis elective surgery. The goal of this research is to develop a minimally invasive method of analyzing the PVP waveforms and find correlations with volume loss. Twenty-three pyloric stenosis patients PVP were acquired at five stages and were divided into euvolemic, normal fluid volume, and hypovolemic, significant fluid loss. Seven craniosynostosis patients were enrolled and the PVP was acquired at the intervention to explore if the isoflurane dosage influences the PVP. A multivariate analysis of variances (MANOVA) was used to test if the PVP was influenced by the volume change and the anesthetic drugs effect. Prediction algorithms based on Fast Fourier Transform were utilized at the two cohort patients analyses to classify an arbitrary PVP into its correct classification. Our research found that PVP signal is influenced by the different hemodynamics states of the body. Based on MANOVA outcomes, we built prediction systems and they were able to categorize an arbitrary PVP signal into its correct classification. The k-nearest neighbor (k-NN) model correctly predicted 77% of the data in the euvolemic and hypovolemic groups. The k-NN models of the anesthetic drugs were able to correctly predict correctly at least 85% of the preoperative and intraoperative signals of the pyloric stenosis patients and the different isoflurane dosages of the craniosynostosis patients. Analyzing the PVP signal is a promising tool for measuring the dehydration level in acute settings. Our results imply that the subsequent changes in vascular resistance due to inhaled and infused anesthetics are reflected in the peripheral veins. A technology that would accurately assess the volume status of a patient to guide triage and treatment would be a significant improvement in various care settings. This minimally invasive technology utilizes a standard peripheral intravenous line and a commercial pressure-monitoring transducer, which exist today and requires no new clinical skills

Suppression of antibody formation by the reticuloendothelial (RES)-blockade. I. Effects of the RES-blockade with macromolecular polyvinyl pyrrolidone

For the purpose of revealing the role of the reticuloendothelial system (RES) for the antibody formation, the rats which received the repeated intraperitoneal and subcutaneous injections of a vast amount of PVP were challenged by bovine serum albumin (BSA) introducing through 2 routes of intramuscular and intravenous, and then antibody formation was observed. Blood cell count and clearance rate of radiogold were observed for the purpose of obtaining the information of blockade grade of the RES by PVP. Phagocytic activity of macrophages ingesting PVP against iron colloid were also observed in vitro. 1. A severe anemia was induced by the administration of a vast amount of PVP, 15 ml of 3% solution daily or every other day for 63 days. Histological picture indicated the suppressed erythropoiesis probably by iron deficiency or the lowered iron transporting activity of the RES, as the anemia recovered after intraperitoneal iron injections. 2. With the generalized and marked swelling of the RES, the cells in germinal center of spleen and lymph nodes were extremely swollen and lymphocytes disappeared completely, suggesting that the macrophages in germinal center play an important role in reproduction and differentiation of lymphocytes. 3. The phagocytic activity of the RES as understood from the clearance rate of radiogold was suppressed only slightly even by a heavy deposition of PVP after the repeated injections. The state of blockade or the suppressed phagocytic activity persisted for 48 hours or more after the several PVP injections. However, complete blockade of the RES or inactivation of the phagocytic activity by PVP injection was not attained. 4. A prolonged treatment of animals with PVP caused delay in the appearance of circulating antibody but the final titration reached the same level as that of control. The data suggest that the blockade of the RES by PVP induces the delay in the transmittance of the information for the antibody formation from the macrophages to the immunologically competent cells but no delay in the ingesting antigen by the macrophages.</p

TRIPS and plant varietal protection : economic analysis and policy choices

This paper reviews the economic aspects of the options facing developing countries in implementing intellectual property right protection for agricultural plant varieties under the WTO TRIPS agreement (Article 27(3)b). The various provisions possible in a sui generis system of plant varietal protection (PVP) are summarised, including those specified in the existing Union for the Protection of New Varieties of Plants (UPOV) treaties of 1978 and 1991. The paper then examines the limited economic research that has been conducted on the impacts of PVP and that may be of use to policy makers faced with current decisions. This review finds that the research to-date has not yet demonstrated overwhelming net benefits from PVP. The evidence so far is weakly supportive of positive contributions by PVP to agricultural productivity. The paper concludes further research on this issue is necessary given the ongoing review of the TRIPS agreement and the efforts underway in many developing countries to implement such systems. The paper also identifies some of the key topics forming a research agenda of interest for developing countries. Further research should focus on the impacts of specific provisions, in particular, that of farm-saved seed, as opposed to the effects of PVP as a whol

Characterization of new membrane materials by means of fouling experiments Adsorption of bsa on polyetherimide-polyvinylpyrrolidone membranes

The hydrophilicity of polyetherimide-polyvinylpyrrolidone (PEI-PVP) microfiltration membranes can be adjusted by means of a suitable post-treatment. The influence of the nature of the membrane surface on fouling properties was studied using permeation experiments before and after exposure to a protein (BSA) solution and adsorption experiments with 14C labelled BSA. A correlation between the permeation experiments and the radiolabelled BSA adsorption experiments was found. The PVP in the membrane matrix prevents BSA adsorption taking place to a large extent and it appeared that heat-treated PEI-PVP membranes showed the same nonfouling behaviour as, for example, cellulose acetate membranes

Application of Texture Analysis technique in formulation development of lyophilized orally disintegrating tablets containing mannitol, polyvinylpyrrolidone and amino acids

The file attached to this record is the author's final peer reviewed version. The Publisher's final version can be found by following the DOI link.Orally disintegrating tablets (ODTs) attract a great attention as this easy swallowing dosage form often improves patient compliance. In the current work, orally disintegrating tablets comprising mannitol, polyvinylpyrrolidone (PVP) and an amino acid (alanine, glycine or serine) with various PVP-to-amino acid ratios were formulated. The combination of mannitol and an amino acid was aimed to use the advantages of mannitol, the matrix-supporting and disintegration agent, and to reduce the total amount of sugar/polyol in tablets. Tablets were manufactured by freeze-drying and their properties (appearance, internal structure, disintegration, mechanical and texture properties, moisture uptake, shrinkage, thermal properties) were assessed. In the work, great emphasis was placed on illustrating the applicability of the Texture Analysis of the freeze-dried cakes directly in vials in formulation development. The results show that the appearance, mechanical properties, disintegration and shrinkage of the freeze-dried ODTs depend significantly on the excipient composition with PVP playing the leading role. Partial mannitol replacement with an amino acid has a limited impact on the tablet properties. The presence of an amino acid also has no impact on the PVP-mannitol interaction. The mechanical and texture properties of freeze-dried ODTs depend non-linearly on the PVP content. The transition between the different types of textures occurs in a narrow range of PVP concentrations regardless of the type of amino acid in a formulation. The non-linear effect of PVP on various tablet properties should be taken into account when designing ODT formulations as it can compromise the robustness of the manufacturing process

Electrolyte effects on polyacrylic acid-polyvinylpyrrolidone aqueous glycol mixtures for use as de-icing fluids

Rheological and wind tunnels measurements are presented for mixtures of polymers polyacrylic acid [PAA] and polyvinylpyrrolidone [PVP] polymers dispersed in water-1,2 propylene glycol mixture to examine their use as potential aircraft de-icing fluids. PAA solutions which form the basis of de-icing fluids are known to result in undesirable gelation which may lead to undesirable and catastrophic consequences in such applications. In this study, we examine the blending of PVP with PAA blends as alternative de-icing fluid formulations that can reduce the likelihood of forming such irreversible gel deposits. Through adjustment of the electrolyte concentration, the ratio of PAA to PVP as well as the molecular weight of PVP, it is possible to achieve a required viscosity profile to that exhibited by a model de-icing fluid across a range of appropriate temperatures. Wind tunnel tests indicate that the mixtures are capable of meeting the necessary requirements for boundary layer depletion as well as having sufficient capability of retaining a stable layer required during aircraft taxiing

An Empirical Analysis of the Effects of Plant Variety Protection Legislation on Innovation and Transferability

Under the TRIPs Agreement, all member-countries of the World Trade Organization are required to provide an "effective" system of plant variety protection within a specific time frame. In many developing countries this has led to a divisive debate about the fundamental desirability of extending intellectual property rights to agriculture. But empirical studies on the economic impacts of PVP, especially its ability to generate large private sector investments in plant breeding and facilitate the transfer of technology, have been very limited. This paper examines two aspects of the international experience of PVP legislation thus far (i) The relationship between legislation, R&D expenditures and PVP grants, i.e., the innovation effect, and (ii) The role of PVP in facilitating the flow of varieties across countries, i.e., the transferability effect.Plant variety protection, biotechnology, technology transfer, Crop Production/Industries,