Search results for "Assay"
showing 10 items of 2241 documents
cis-Dichloroplatinum(II) complexes tethered to dibenzo[c,h][1,6]naphthyridin-6-ones: Synthesis and cytotoxicity in human cancer cell lines in vitro
2013
A novel family of cisplatin-type complexes tethered to dibenzo[c,h][1,6]naphthyridin-6-one topoisomerase inhibitor via a polymethylene chain and their nonplatinated counterparts were prepared. Their potential cytotoxicity was assessed in three human colorectal cancer cell lines HCT 116, SW480 and HT-29 and compared to the reference molecules cisplatin and oxaliplatin. Platinated compounds were poorly active whilst nonplatinated dibenzo[c,h][1,6]naphthyridin-6-one moieties exhibited higher cytotoxic properties than cisplatin and oxaliplatin whatever the length of the polymethylene chain; molecules containing the tri- and hexamethylene chain length were the most cytotoxic.
Amino acids requirements of measles virus in HeLa cells.
1973
A low plating efficiency for measles virus was obtained when arginine, threonine and isoleucine were omitted from Eagle's basal medium and a stimulatory effect on the plaque production was produced by increasing the concentration up to 0.5 mm of arginine and glutamine. However, of all amino acids in Eagle's basal medium, only methionine was found to be essential for the synthesis of infectious progeny virus. Omission of any one of the other amino acids from the culture medium permitted limited virus production, but none whatever could be detected in the absence of mediummethionine. Moreover, when methionine was restored to infected cultures after 24 hours of deprivation, release of virus be…
A hantavirus nucleocapsid protein segment exposed on hepatitis B virus core particles is highly immunogenic in mice when applied without adjuvants or…
2005
Hepatitis B virus (HBV) core particles carrying the amino-terminal 120 amino acids (aa) of the nucleocapsid (N) protein of the hantaviruses Dobrava, Hantaan or Puumala have been demonstrated to be highly immunogenic in mice when complexed with adjuvants. Here we demonstrate that even without adjuvant, these chimeric particles induced high-titered, and strongly cross-reactive N-specific antibody responses in BALB/c and C57BL/6 mice. The induced N-specific antibodies represented all IgG subclasses. Pre-existing core-specific antibodies did not abrogate the induction of an N-specific immune response by a hantavirus N insert presented on core particles. Therefore, chimeric core particles should…
A real time immunoassay in alumina membranes
2014
To date, photonic biosensing with porous membranes has produced slow responses and long sensing times, due to the narrow (less than 100 nm) closed end pores of the membranes used. Recently, polarimetry was used to demonstrate analyte flow through, and real time biosensing in, free-standing porous alumina membranes. Here, we demonstrate how an improved functionalization technology, has for the first time enabled a real-time immunoassay within a porous membrane with a total assay time below one hour. With the new approach, we show a noise floor for individual biosensing measurements of 3.7 ng/ml (25 pM), and a bulk refractive index detection limit of 5×10-6 RIU, with a standard deviation of l…
Signals involved in the early TH1/TH2 polarization of an immune response depending on the type of antigen.
1999
Abstract Background: The early production of distinct cytokines by epidermal cells (ECs) in response to antigen exposure may govern the development of T H1 -like immune responses, such as contact sensitivity, or T H2 -like immune responses, such as IgE-dependent allergies of the immediate type, depending on the type of antigen. Objective: The aim of this study was to compare the signals induced by protein allergens with those induced by haptens in ECs and subsequently in local draining lymph node cells (LNCs) or splenocytes. Methods: BALB/c mice were primed in vivo with the protein allergens ovalbumin or birch pollen or the haptens 2,4-dinitrofluorobenzene or trinitrochlorbenzene, respectiv…
In human and rat lung membranes [35s]GTPγS binding is a tool for pharmacological characterization of G protein-coupled devucleotide receptors
1999
The P2Y receptor family is activated by extracellular nucleotides such as ATP and UTP. P2Y receptors regulate physiological functions in numerous cell types. In lung, the P2Y2 receptor subtype plays a role in controlling Cl- and fluid transport. Besides ATP or UTP, also diadenosine tetraphosphate (Ap4A), a stable nucleotide, seems to be of physiological importance. In membrane preparations from human and rat lung we applied several diadenosine polyphosphates to investigate whether they act as agonists for G protein-coupled receptors. We assessed this by determining the stimulation of [35S]GTPgammaS binding. Stimulation of [35S]GTPgammaS binding to G proteins has already been successfully ap…
Seasonal Human Coronavirus Respiratory Tract Infection in Recipients of Allogeneic Hematopoietic Stem Cell Transplantation
2021
Abstract Background Little is known about characteristics of seasonal human coronaviruses (HCoVs) (NL63, 229E, OC43, and HKU1) after allogeneic stem cell transplantation (allo-HSCT). Methods This was a collaborative Spanish and European bone marrow transplantation retrospective multicenter study, which included allo-HSCT recipients (adults and children) with upper respiratory tract disease (URTD) and/or lower respiratory tract disease (LRTD) caused by seasonal HCoV diagnosed through multiplex polymerase chain reaction assays from January 2012 to January 2019. Results We included 402 allo-HSCT recipients who developed 449 HCoV URTD/LRTD episodes. Median age of recipients was 46 years (range,…
Influence of the functionalisation of mesoporous silica material UVM-7 on polyphenol oxidase enzyme capture and enzymatic browning
2020
Polyphenol oxidase (PPO), also known as tyrosinase and catechol oxidase, is the enzyme responsible for enzymatic browning in foods. It causes undesirable organoleptic, nutritional and colour changes. Here, we report the preparation of five nanomaterials and a study of their ability to modulate PPO enzyme activity. The materials consist of UVM-7 supports (a mesoporous silica material) modified with diverse functional groups (i.e. amine, carboxylic acid, isocyanate, alkane and pyridine). We also studied the PPO immobilisation capability of the materials. All the materials, except the carboxylic acid functionalised one, offer high PPO loading capabilities and the immobilisation speed increases…
Anti-inflammatory properties of hydroalcoholic extracts of Argentine Puna plants
2015
The aim of this study is to evaluate the activity of thirteen hydroalcoholic extracts obtained from aerial parts of plants from Argentina Puna on pro-inflammatory enzymes and inflammatory mediators. Eleven extracts were non-cytotoxic on RAW 264.7. Data obtained suggest the capacity of these Argentine Puna plant extracts to inhibit the production of inflammatory mediators (nitric oxide and prostaglandin) at different levels. The plant extracts can affect enzymes expression and/or enzymes activity, and they can also act by NO scavenging. Each extract exerts its anti-inflammatory effect through different mechanisms. The inhibitory ability on pro-inflammatory enzymes by these hydroalcoholic ext…
Cytotoxic activity of some natural and synthetic guaianolides
2005
Several natural guaianolides and synthetic derivatives of repin (1) were tested and found to be active against tumor cell replication. Repin (1) and both mono- and di-halohydrin analogues (2, 7-9, 11, 12) showed significant antitumor potency. A more effective compound (17) was obtained by esterificating repin with the paclitaxel side chain.