A novel electrically conductive and biodegradable composite made of polypyrrole nanoparticles and polylactide.

A novel electrically conductive biodegradable composite material made of polypyrrole (PPy) nanoparticles and poly(d,l-lactide) (PDLLA) was prepared by emulsion polymerization of pyrrole in a PDLLA solution, followed by precipitation. The composite was characterized by scanning electron microscopy and X-ray photoelectron spectroscopy. The electrical stability of the composite containing 5 wt% PPy was investigated in a cell culture environment for 1000 h with 100 mV DC applied voltage.

Direct electrochemical detection of oligonucleotide hybridization on poly(5-hydroxy-1,4-naphthoquinone- co-5-hydroxy-3-thioacetic acid-1,4-naphthoquinone) film.

We describe the construction of a new DNA-modified electrode based on an electroactive film. 5-Hydroxy-1,4-naphthoquinone is coelectrooxidized with 5-hydroxy-3-thioacetic acid-1,4-naphthoquinone to give a copolymer, presenting both electroactive and chemically reactive groups. The carboxylic function acts as a precursor for the covalent grafting of ODN probes while the quinone group acts as the transduction element of hybridization.

A biodegradable electrical bioconductor made of polypyrrole nanoparticle/poly(D,L-lactide) composite: A preliminary in vitro biostability study.

The electrical stability of a novel polypyrrole (PPy)/poly(D,L-lactide) (PDLLA) composite was studied in vitro and compared with that of PPy-coated polyester fabrics. Specimens were incubated in Ringer's solution at 37 degrees C for up to 8 weeks with or without the circulation of DC current under a constant 100 mV voltage. In situ current variation with incubation time was recorded.

Antioxidant constituents of almond [Prunus dulcis (Mill.) D.A. Webb] hulls.

Almond hulls (Nonpareil variety) were extracted with methanol and analyzed by reversed phase HPLC with diode array detection. The extract contained 5-O-caffeoylquinic acid (chlorogenic acid), 4-O-caffeoylquinic acid (cryptochlorogenic acid), and 3-O-caffeoylquinic acid (neochlorogenic acid) in the ratio 79.5:14.

The pharmacokinetic and pharmacodynamic characteristics of a long-acting growth hormone (GH) preparation (nutropin depot) in GH-deficient adults.

A pharmacokinetic-pharmacodynamic study of a long-acting GH [Nutropin Depot; somatropin (rDNA origin) for injectable suspension] was performed in 25 patients with adult GH deficiency. Single doses of 0.25 mg/kg and 0.

Biostability of electrically conductive polyester fabrics: an in vitro study.

The biostability of a series of polypyrrole (PPy)-coated polyester fabrics was investigated in an in vitro model. PPy-coated sample fabrics were incubated in saline at 37 degrees C for 1 and 2 weeks. After each period of incubation, the surface electrical resistivity of the sample fabrics was measured to monitor the changes caused by the incubation.

Sustained delivery of human growth hormone from a novel gel system: SABER.

Purpose: The purpose of this study was to evaluate the release of recombinant human growth hormone (rhGH) from a novel non-polymeric sustained release system, SABER.

Methods: The SABER system consists of sucrose acetate isobutryate, a solvent and a polymeric release modifier. Spray dried formulations of zinc complexed rhGH in sodium bicarbonate containing sucrose and polysorbate 20 were homogenized with various SABER systems (10% w/v rhGH) and assessed in vitro and in vivo (rat studies).

[Efficiency and specificity of the KAT-test for rapid diagnosis of falciparum malaria].

A new rapid KAT Quick Malaria test for the diagnosis of falciparum malaria, which is based on the detection of a monoclonal antibody-antigen complex of malaria parasites, has been worked out by the KAT Medical CC in South Africa. The efficiency and specificity of the KAT test were compared with those of the microscopic method and with the ICT test for rapid diagnosis of P. falciparum and P.

Tissue reaction to polypyrrole-coated polyester fabrics: an in vivo study in rats.

Electrically conductive polypyrrole is very attractive for tissue engineering because of its potential to modulate cellular activities through electrical stimulation. However, its in vivo behaviors have not been fully studied. This paper investigates the in vivo biocompatibility and biostability of PPy-coated polyester fabrics.

Impaired transendothelial migration of B-CLL lymphocytes: a defect linked to low L-selectin expression.

The emigration of lymphocytes from blood into lymph nodes is regulated by the expression of the adhesion molecule, L-selectin on the lymphocyte surface which arrests the rolling of the cell on the vessel wall and allows firmer adhesive interactions to develop. The expression of L-selectin on B-CLL lymphocytes is less than half that on normal lymphocytes and this difference correlates with an impaired capacity of B-CLL lymphocytes to migrate beneath a monolayer of human umbilical vein endothelial cells. Both the B-cell and T-cell lymphocytes from normal subjects and B-CLL patients show down-regulation of L-selectin and CD23 after transendothelial migration.

Processing effects on lycopene content and antioxidant activity of tomatoes.

Consumption of tomato products has been associated with decreased risk of some cancer types, and the tomato antioxidant, lycopene, is thought to play an important role in the observed health effects. In this study, four carotenoids, trans-lycopene, phytofluene, phytoene, and zeta-carotene, were quantified in tomato products. Samples of raw tomatoes, tomato juice after hot break scalder, and final paste were obtained from two different processing plants over two years.

Resistance of Plasmodium falciparum to antimalarial drugs in a highly endemic area of southern Viet Nam: a study in vivo and in vitro.

To assess the antimalarial sensitivity of Plasmodium falciparum in vivo and in vitro in a highly endemic area of southern Viet Nam, a field study was conducted (in 1999) at a rubber plantation in Binh Phuoc Province north of Ho Chi Minh City. Fifty patients were treated with either artesunate (4 mg/kg on day 0, then 2 mg/kg on day 1 to 4) or mefloquine (10 mg/kg at 0 h, then 5 mg/kg at 6 h), and their progress was followed for 28 days under standard WHO protocols. Blood spots were taken at baseline from all patients, as well as from those who redeveloped parasitaemia during follow-up, for polymerase chain reaction (PCR) determination of parasite genotypes to assist differentiation of re-infection from recrudescence.

Identification of benzethonium chloride in commercial grapefruit seed extracts.

Commercial grapefruit seed extracts (GSE) were extracted with chloroform. The solvent was evaporated, and the resulting solid was subsequently analyzed by high-performance liquid chromatography, electrospray ionization mass spectrometry, nuclear magnetic resonance (NMR) spectroscopy, and elemental analysis (by proton-induced X-ray emission [PIXE] analysis). The main constituent was identified as benzethonium chloride, a synthetic antimicrobial agent commonly used in cosmetics and other topical applications.

In vitro biocompatibility study of electrically conductive polypyrrole-coated polyester fabrics.

This study investigated the basic biocompatibility aspects of two types of polypyrrole (PPy)-coated polyester fabrics for possible use as vascular prostheses. These PPy-coated fabrics, PPy-Phos and PPy-Plas, were sterilized with ethylene oxide (EO) and the following characterizations were performed: surface morphology by scanning electron microscope, EO residuals analysis by the headspace method, acute systemic toxicity in the mouse model, hemolysis, blood coagulation time, viability and proliferation of endothelial cells measured with the WST-1 method, and activation of polymorphonuclear (PMN) cells indicated by the specific expression of interleukin 8 mRNA measured by reverse transcription polymerase chain reaction. Virgin polyester fabrics, expanded poly(tetrafluoroethylene) (ePTFE), and medical-grade Bionate 80A poly(carbonate urethane) were used as references in the cell culture experiments.

Diazepam induces FGF-2 mRNA in the hippocampus and striatum.

starting by 6 h following diazepam injection and returning to approximately control values by 24 h. In situ hybridization showed elevated FGF-2 mRNA labeling in the hippocampal formation, mostly in the pyramidal layer of the CA1 and CA2 subfields and in the dentate gyrus hilar region. These results indicate that diazepam treatment up-regulates FGF-2 expression in select regions of the brain and suggest that GABA may promote neuroplasticity in concert with FGF-2.

Identification of three triterpenoids in almond hulls.

Three triterpenoids, betulinic acid, oleanolic acid, and ursolic acid, were isolated as their methyl esters (treatment with diazomethane) from diethyl ether extracts of almond hulls (Nonpareil variety) using flash chromatography and preparative high-performance liquid chromatography. The triterpenoids, which comprised approximately 1% of the hulls, were characterized using chromatographic and spectroscopic methods. These studies demonstrate that almond hulls are a rich source of these triterpenoids, which have reported anti-inflammatory, anti-HIV, and anti-cancer activities.

Polymerization and surface analysis of electrically-conductive polypyrrole on surface-activated polyester fabrics for biomedical applications.

A new synthetic route is reported for the synthesis and covalent bonding of electrically conductive polypyrrole to a poly(ethylene terephthalate) fabric. It involves a three-step process including surface phosphorylation and graft polymerization from the gaseous phase. In the first step, the fibre surfaces are activated using phosphorus trichloride.

[Pleuropulmonary staphylococcal infection in infants, in a hospital environment in Ouagadougou (Burkina Faso)].

We observed 36 cases of pleuropulmonary staphylococcal infection (PPS) in infants aged 0 to 30 months, during a prospective study carried out between April 1st 1995 and March 31 1996 at the Pediatrics Department of Ouagadougou University Hospital. PPS accounted for 0.5% of all hospital admissions and 11.

Diazepam induces FGF-2 and its mRNA in the spinal cord.

We have explored the possibility that the GABA system can influence the expression of FGF-2 in the spinal cord. The GABA agonist diazepam was systemically injected in adult rats, and the expression of FGF-2 was examined in the cervical spinal cord region between 6 h and 7 days post-injection. Results of nuclease protection assays showed increases in FGF-2 mRNA, starting by 6 h and returning to approximately control values by 3 days.

Impact of mutations within the putative Ca2+-binding lumenal interhelical a-b loop of the photosystem II D1 protein on the kinetics of photoactivation and H2O-oxidation in Synechocystis sp. PCC6803.

Mutations D1-D59N and D1-D61E in the putative Ca2+-binding lumenal interhelical a-b loop of the photosystem II (PSII) D1 protein [Chu, H. A., Nguyen, A.

Transendothelial migration of lymphocytes in chronic lymphocytic leukaemia is impaired and involved down-regulation of both L-selectin and CD23.

Chronic lymphocytic leukaemia (B-CLL) is characterized by a progressive accumulation of B lymphocytes in blood and bone marrow and high concentrations of soluble CD23 and L-selectin are found in the serum of these patients. In this study lymphocytes from normal subjects and patients with B-CLL were allowed to undergo transendothelial migration across confluent layers of human umbilical vein endothelial cells. Lymphocytes in B-CLL samples showed an impaired capacity to migrate while the minor proportion of normal T cells was enriched by a mean of 2.

B-cell chronic lymphocytic leukaemia with CD8 expression: report of 10 cases and immunochemical analysis of the CD8 antigen.

We report 10 cases of B-cell chronic lymphocytic leukaemia (B-CLL) with expression of the T-cell antigen CD8. The majority of patients had typical B-cell CLL with stable and non-progressive stage A(O) disease except for more common expression of lambda light chain and CD25. Two patients had progressive disease and required therapy, one with atypical morphological and phenotypic features.

In vitro cellular response to polypyrrole-coated woven polyester fabrics: potential benefits of electrical conductivity.

Electrically conducting polypyrrole-treated films have recently been shown to influence the morphology and function of mammalian cells in vitro. This type of polymer represents a possible alternative biomaterial for use in vascular implantation. The present study compared the in vitro biocompatibility of the five different polyester woven fabrics having increasing levels of electrical conductivity ranging from 4.

Resistance to antifolates in Plasmodium falciparum monitored by sequence analysis of dihydropteroate synthetase and dihydrofolate reductase alleles in a large number of field samples of diverse origins.

Resistance of Plasmodium falciparum to antifolate chemotherapy is a significant problem where combinations such as Fansidar (pyrimethamine-sulfadoxine; PYR-SDX) are used in the treatment of chloroquine-resistant malaria. Antifolate resistance has been associated with variant sequences of dihydrofolate reductase (DHFR) and dihydropteroate synthetase (DHPS), the targets of PYR and SDX respectively. However, while the nature and distribution of mutations in the dhfr gene are well established, this is not yet the case for dhps.

Physical exercise induces FGF-2 and its mRNA in the hippocampus.

Clinical and experimental evidence indicate that physical activity has a positive impact on brain function; however, the molecular bases for how exercise affects the structure and function of the brain are largely unknown. We have investigated the influences of variable periods of voluntary wheel-running on the expression of basic fibroblast growth factor and its mRNA in various brain regions. Nuclease protection assays revealed that the hippocampus was the only region examined exhibiting changes in FGF-2 mRNA as a result of exercise.