Search results for "Dose"
showing 10 items of 2247 documents
Effects of dopamine in isolated rat colon strips.
2005
The aim of the present work is to investigate the effects of dopamine on isolated rat colon strips, and whether dopamine receptors are involved in these effects. Experiments on spontaneous motility and under potassium contraction were performed with dopamine and isoprenaline, both in the absence and presence of antagonists (distal colon strips, isotonic recording, Tyrode solution, 31 °C, 1 g of resting tension). At higher concentration (10–4mol/L), dopamine abolished spontaneous motility of the rat colon and this effect was not modified by antagonists. In isolated rat colon strips that were depolarized with potassium, dopamine produced concentration-dependent relaxation, without significant…
Modulatory role of a constitutively active population of α1D-adrenoceptors in conductance arteries
2002
A constitutively active population of α1D-adrenoceptors in iliac and proximal, distal, and small mesenteric rat arteries was studied. The increase in resting tone (IRT) that evidences it was observed only in iliac and proximal mesenteric and was inhibited by prazosin (pIC50 = 9.57), 5-methylurapidil (pIC50 = 7.61), and BMY 7378 (pIC50 = 8.77). Chloroethylchlonidine (100 μmol/l) did not affect IRT, but when added before the other antagonists it blocked their effect. The potency shown by BMY 7378 confirms the α1D-subtype as responsible for IRT. BMY 7378 displayed greater inhibition of adrenergic responses in iliac (pIC50 = 7.57 ± 0.11) and proximal mesenteric arteries (pIC50 = 8.05 ± 0.2) th…
Pruritus precipitated by hydroxyethyl starch: a review.
2005
Summary Hydroxyethyl starch (HES) is widely used for fluid management in broad populations of patients, particularly in the surgery and intensive care settings. Pruritus, often manifested as pruritic crises, is increasingly being recognized as a common major adverse effect of HES administration. This iatrogenic form of pruritus is frequently severe and protracted with a serious negative impact on patient quality of life, including sleep disturbance, disruption of daily routine and mental distress. Such pruritus is generally refractory to available therapies and can persist for up to 12–24 months. All currently clinically available HES solutions entail the risk of pruritus, including those o…
Editorial: CBCT special issue
2014
In the dental community, it is a common belief that CBCT was invented for oral and maxillofacial imaging. Of course, we know that this is a myth since the technique of a volumetric CT is indeed much older and dates back to the late 1970s.1,2 Considering that CT was introduced in 1973, its volumetric counterpart was developed very soon thereafter driven by the need for high spatial and temporal resolution that a conventional CT at that time was not able to achieve. However, successful marketing of the technique indeed was much later, and certainly a consequence of the publication of “A new volumetric CT machine for dental imaging based on the cone-beam technique: preliminary results” by Mozz…
Practical recommendations for the application of DE 59/2013
2019
The changes introduced with Council Directive 2013/59/Euratom will require European Member States adapt their regulations, procedures and equipment to the new high standards of radiation safety. These new requirements will have an impact, in particular, on the radiology community (including medical physics experts) and on industry. Relevant changes include new definitions, a new dose limit for the eye lens, non-medical imaging exposures, procedures in asymptomatic individuals, the use and regular review of diagnostic reference levels (including interventional procedures), dosimetric information in imaging systems and its transfer to the examination report, new requirements on responsibiliti…
Hepatic mesenchymal hamartoma in a preterm newborn: demonstration by low-dose multidetector CT.
2007
Primary liver tumours are very rare in the neonatal period. Differential diagnoses include haemangioendothelioma, malignant hepatoblastoma and mesenchymal hamartoma. Due to non-specific clinical symptoms and indecisive imaging findings, correct diagnosis may be difficult to establish. We report a female preterm newborn who was delivered at 33 weeks of gestation and in whom ultrasonography (US) revealed a large cystic intraabdominal tumour of unknown origin. For further evaluation, contrast-enhanced multidetector computed tomography (CT) was performed on the 4th day of life using a low-dose protocol (80 kVp, 50 mAs, collimation 0.75 mm, total effective dose 3.6 mSv). Based on CT findings, di…
Radiation exposure in CT-guided interventions.
2013
To investigate radiation exposure in computed tomography (CT)-guided interventions, to establish reference levels for exposure, and to discuss strategies for dose reduction.We analyzed 1576 consecutive CT-guided procedures in 1284 patients performed over 4.5 years, including drainage placements; biopsies of different organs; radiofrequency and microwave ablations (RFA/MWA) of liver, bone, and lung tumors; pain blockages, and vertebroplasties. Data were analyzed with respect to scanner settings, overall radiation doses, and individual doses of planning CT series, CT intervention, and control CT series.Eighty-five percent of the total radiation dose was applied during the pre- and post-interv…
Mechanism of New Antipsychotic Medications
2003
Antagonism of D 2 -like dopamine receptors is the putative mechanism underlying the antipsychotic efficacy of psychotropic drugs. Positron emission tomographic studies suggest that the antipsychotic effect of dopamine receptor antagonists occurs within a therapeutic window between 60% and 80%(striatal) D 2 receptor occupancy. The incidence of extrapyramidal side effects increases above the 80% threshold. However, the novel atypical antipsychotic drug, aripiprazole, occupies up to 95% of striatal D 2 -like dopamine receptors at clinical doses, and the incidence of extrapyramidal side effects with aripiprazole is no higher than with placebo. The most likely explanation for this finding is ari…
SEXUALHORMONE-BINDING GLOBULINE (SHBG) AND FREE TESTOSTERONE (FTE) IN PATIENTS WITH ULLRICH TURNLR SYNDROME(UTS) RECEIVING OXANDROLONE
1993
Our investigation showed that the concentration of SHBG decreased in healthy girls and boys at increased FIE concentrations. It was therefore the aim of the present study to examine the effects of anabolic steroid oxandrolone in SHBG and FTE concentrations in patients with Turner's syndrome. The normal dose to promote growth in patients wilh UTS is 0,1 mg/kg/BW. Our patients received a very low dose of 1,25 mg oxandrolone/doy. We analysed 21 sera of UTS patients. The determination of SHBG concentrations was performed with the IRMA (Famos diagnostics, Oulunsala, Finnland), the concentration of FTE was determined with the RIA (Immunchem.Corporation, Carson, USA). In 7 untreated UIS patients w…
Reduced-dose of doublet chemotherapy combined with anti-EGFR antibodies in vulnerable older patients with metastatic colorectal cancer: Data from the…
2022
Abstract Objectives To assess the toxicity patterns and effectiveness of doublet chemotherapy when administered at reduced doses of 20% (FOLFOX or FOLFIRI) in combination with anti-EGFR antibodies (cetuximab or panitumumab) in old, vulnerable patients with metastatic colorectal cancer (mCRC). Patients and methods We performed a retrospective observational study of RAS and BRAF wild-type, vulnerable patients aged ≥70 years with previously untreated mCRC. The primary endpoint was safety, and secondary endpoints were overall response rate (ORR), progression-free survival (PFS), and overall survival (OS). Results One hundred and eighteen patients were collected from 14 selected Italian centres.…