Search results for "substitut"
showing 10 items of 1337 documents
Investigation of inhibitory effects on EPC-mediated neovascularization by different bisphosphonates for cancer therapy.
2013
Bisphosphonates (BPs) are potent drugs, used in metastatic cancer-like prostate or breast carcinoma. In recent studies, besides reduced bone remodeling, influences on angiogenesis and neovascularization were reported. Since BPs have the tendency to accumulate in the bones, the biological effect of various nitrogen- and non-nitrogen BPs on endothelial progenitor cells (EPCs) that originated from bone marrow and mobilized under physiological and pathophysiological conditions, such as tumor neovascularization, was investigated. EPCs subsequent to 72-h treatment with different concentrations of bisphosphonates comprised the non-nitrogen-containing BP clodronate and the nitrogen-containing BPs i…
Endometrial Adenocarcinoma in Syrian Hamsters Treated with Diethylstilbestrol, Tamoxifen and N-Ethyl-Nitrosourea
2006
The synthetic estrogen diethylstilbestrol (DES) causes marked abnormalities in the female hamster genital tract, after either prenatal or postnatal exposure, leading to endometrial hyperplasia and carcinoma. Acting as an initiating event, DES altering uterine development may facilitate the abnormal response of promoting agents. Tamoxifen (TAM) is an antiestrogen that competes for central and peripheral estrogen receptor (ERα). TAM exerts agonistic effects on E-dependent endometrial proliferation. N-ethyl-N-nitrosourea (ENU), a potent mutagenic agent, induces tumors in a variety of organs, predominantly in the peripheral nervous system. To test whether ENU and TAM treatment in a model of hyp…
Pharmacokinetics and pharmacodynamics of hydroxyethyl starch in hypovolemic pigs; a comparison of peripheral and intraosseous infusion.
1999
Intraosseous (i.o.) infusion is considered a useful technique for the administration of medications and fluids in emergency situations when peripheral intravascular access is not possible. This study investigated the effectiveness of i.o. versus intravenous (i.v.) infusion of hydroxyethyl starch (HES 200/0.5) in hypovolemic pigs. Twenty-three pigs (8- to 9-week-old) were anaesthesized, instrumented and blood was withdrawn (25-30 ml/kg) to50 mmHg mean arterial pressure (MAP). The animals were left untreated in haemorrhage for 30 min. Relevant haemodynamic parameters were monitored and blood samples were collected for blood gas and HES concentration analysis. Infusion of HES via i.v. or i.o. …
The Impact of Hormone Therapy on Health
2017
Hormone therapy (HT) has menopausal symptom control as the main indication. However, and because estrogens have receptors spread over many systems in the body, the use of hormones may have consequences on health. Hormone therapy consists of estrogens essentially, since menopausal symptoms mainly derive from estrogen deprivation at different target tissues. However, the normal ovarian cycle includes the regular secretion of progesterone during the days of the luteal phase. Progesterone has a neutralizing effect over endometrial proliferation, this being the reason for adding progestogens to HT formulations in order to protect endometrium. So, guidelines recommend that women with uterus use e…
Alcohol and Cannabis Consumption Does Not Diminish Cure Rates in a Real-World Cohort of Chronic Hepatitis C Virus Infected Patients on Opioid Substit…
2019
Background: The importance of alcohol and cannabis consumption for the effectiveness of treatment of chronic hepatitis C virus (HCV) infection with direct acting antivirals (DAAs) in people on opioid substitution therapy (OST) has not been investigated in detail. Methods: We investigated sustained virological response (SVR) rates and proportion of lost to follow-up (LTFU) between OST (n = 739) and non-OST patients (n = 7008) in the German Hepatitis C-Registry (Deutsches Hepatitis C-Register, DHC-R), which is a national multicenter prospective non-interventional real-world registry. Non-OST patients comprised patients with former/current drug use (non-OST/DU; n = 1500) and patients never con…
Rapid Synthesis of Unsymmetrical Sulforhodamines Through Nucleophilic Amination of a Monobrominated Sulfoxanthene Dye
2014
A transition-metal-free method for the synthesis of N-substituted unsymmetrical sulforhodamine fluorophores from an unusual monobrominated sulfoxanthene dye and primary or secondary amines by direct SNAr-type reactions is presented. The simplicity and effectiveness of this “postamination” procedure were demonstrated through the rapid preparation of a library of multifunctional red-emitting rhodamine analogues. Some of these analogues are equipped with a reactive handle and retain the two water-solubilizing sulfonic acid moieties of the starting halogenated derivative; this makes them ideal candidates for biolabeling applications. The potential utility of this expeditious strategy to finely …
Insights into the Synthesis and the Solution Behavior ofmeso-Aryloxy- and Alkoxy-Substituted Porphyrins
2015
meso-RO-appended (R = alkyl, aryl) porphyrins bearing one or two OR substituents at the tetrapyrrolic macrocycle were synthesized in good yields from 5,15-dibromo-10,20-diphenylporphyrins 2H(Br2DPP), Ni(Br2DPP) and Zn(Br2DPP) using an SNAr reaction. By varying the solvent, the base, the temperature, and the time of the reaction, the optimum conditions were established, and the selective introduction of one or two meso-RO substituents at the periphery of the macrocycle was achieved. Moreover, monofunctionalization of Ni(Br2DPP) according to an SNAr reaction was used as a key step for the synthesis of rarely explored unsymmetrical porphyrinyl alkyl ethers. 1H NMR studies of these ethers in CD…
Transport, stability, and biological activity of resveratrol
2011
Numerous studies have reported interesting properties of trans-resveratrol, a phytoalexin, as a preventive agent of several important pathologies: vascular diseases, cancers, viral infections, and neurodegenerative processes. These beneficial effects of resveratrol have been supported by observations at the cellular and molecular levels in both cellular and in vivo models, but the cellular fate of resveratrol remains unclear. We suggest here that resveratrol uptake, metabolism, and stability of the parent molecule could influence the biological effects of resveratrol. It appears that resveratrol stability involves redox reactions and biotransformation that influence its antioxidant properti…
Possible transmission flow of SARS-CoV-2 based on ACE2 features
2020
AbstractAngiotensin-converting enzyme 2 (ACE2) is the cellular receptor for the Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) that is engendering the severe coronavirus disease 2019 (COVID-19) pandemic. The spike (S) protein receptor-binding domain (RBD) of SARS-CoV-2 binds to the three sub-domains viz. amino acids (aa) 22-42, aa 79-84, and aa 330-393 of ACE2 on human cells to initiate entry. It was reported earlier that the receptor utilization capacity of ACE2 proteins from different species, such as cats, chimpanzees, dogs, and cattle, are different. A comprehensive analysis of ACE2 receptors of nineteen species was carried out in this study, and the findings propose a pos…
Methacrylate monolithic columns functionalized with epinephrine for capillary electrochromatography applications.
2013
Epinephrine-bonded polymeric monoliths for capillary electrochromatography (CEC) were developed by nucleophilic substitution reaction of epoxide groups of poly(glycidyl-methacrylate-co-ethylenedimethacrylate) (poly(GMA-co-EDMA)) monoliths using epinephrine as nucleophilic reagent. The ring opening reaction under dynamic conditions was optimized. Successful chemical modification of the monolith surface was ascertained by in situ Raman spectroscopy characterization. In addition, the amount of epinephrine groups that was bound to the monolith surface was evaluated by oxidation of the catechol groups with Ce(IV), followed by spectrophotometric measurement of unreacted Ce(IV). About 9% of all th…