Search results for "Toxic"
showing 10 items of 6968 documents
Aryl hydrocarbon receptor-dependent cell cycle arrest in isolated mouse oval cells
2013
The aryl hydrocarbon receptor (AhR) is a ligand-activated transcription factor, which mediates toxic responses to environmental pollutants, such as 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) and related compounds. Besides its well known role in induction of xenobiotic metabolizing enzymes, for instance CYP1A1, the AhR is also involved in tumor promotion in rodents although the underlying mechanisms are still poorly understood. Additionally, the AhR is known to regulate cellular proliferation, which might result in either inhibition or stimulation of proliferation depending on the cell-type studied. Potential targets in hepatocarcinogenesis are liver oval (stem/progenitor) cells. In the pres…
Release of non-neuronal acetylcholine from the isolated human placenta is affected by antidepressants.
2007
Non-neuronal acetylcholine (ACh) is released from the human placenta into the extracellular space via organic cation transporters (OCTs). The present experiments investigated whether ACh release from epithelial cells is affected by drugs which are substrates of OCTs. The antidepressant drugs amitriptyline and doxepine were tested as both substances are not approved for pregnant women but frequently used. Release of ACh was measured in 10 min intervals over a period of 100 min. Test substances were added from t=50 min of incubation onwards. The effect was calculated by comparing the ACh release of the last three samples (t=70-100 min; B2) with that immediately before the application of the t…
The induction of hepatic microsomal metabolism in rats following acute administration of a mixture of polybrominated biphenyls.
1976
Abstract Firemaster BP6, a mixture of polybrominated biphenyls (PBBs), was administered to female Sprague-Dawley rats (170–180 g) as a single ip injection at 25 and 150 mg/kg. Other animals received phenobarbital (PB), 3-methylcholanthrene (3MC), or PB and 3MC together. Animals were killed at intervals of 12, 24, 48, 192, and 336 hr after treatment with PBBs, or 24 hr after PB, MC, or PB-MC, and various hepatic microsomal parameters were measured. After 150 mg/kg of PBBs, cytochrome P450 concentrations reached a maximum by 48 hr (225% of control), then remained elevated through 336 hr. A similar pattern of induction was observed for epoxide hydratase and aniline hydroxylase activities. In c…
Determination of renal tissue ibandronate levels in rats with normal and mildly impaired renal function
2013
After entering the blood, bisphosphonates are immediately bound to bone or excreted unchanged by the kidney. During renal excretion about 0.5% of administrated dosage remains in kidney tissue. The renal tissue level of bisphosphonates (RTL) decreases over time and remains at about 0.15% after 3weeks, but the influence of renal insufficiency (RI) is unclear.We investigated the influence of mild to moderate RI on RTL of ibandronate (IBD). First a method for determination of RTL was implemented and validated. We measured RTL in rats with normal renal function (SHAM) and after unilateral nephrectomy (UNX). In each case one SHAM and one UNX groups received one or alternatively 9 times every 3wee…
The acute myotoxic effects of bupivacaine and ropivacaine after continuous peripheral nerve blockades.
2003
Bupivacaine causes muscle damage. However, the myotoxic potency of ropivacaine is still unexplored. Therefore, we performed this study to compare the effects of bupivacaine and ropivacaine on skeletal muscle tissue in equipotent concentrations. Femoral nerve catheters were inserted into anesthetized minipigs, and 20 mL of either bupivacaine (5 mg/mL) or ropivacaine (7.5 mg/mL) was injected. Subsequently, bupivacaine (2.5 mg/mL) and ropivacaine (3.75 mg/mL) were continuously infused over 6 h. Control animals were treated with corresponding volumes of normal saline. Finally, muscle samples were dissected at injection sites. After processing and staining, histological patterns of muscle damage…
Evaluation of low-dose metronomic (LDM) cyclophosphamide toxicity in cats with malignant neoplasia
2014
Oral administration of low-dose cyclophosphamide in pets with spontaneously occurring malignant neoplasms has become a common practice in veterinary medicine. The purpose of this retrospective study was to investigate toxicity events in cats with spontaneous malignancies receiving cyclophosphamide as a metronomic therapy for at least 1 month. The number and severity of clinical, haematological and biochemical adverse events were recorded according to the Veterinary Cooperative Oncology Group’s Common Terminology Criteria for Adverse Events v1.1 classification scheme. Twenty-four cats were enrolled in the study with a total number of 27 neoplasms: 13 sarcomas, 12 carcinomas, one melanoma an…
Pharmacokinetic evaluation of mycophenolate mofetil for pemphigus.
2011
Introduction: Pemphigus is an autoimmune blistering disease of the skin and mucous membranes characterized by the development of autoantibodies against the desmosomal proteins, desmoglein-1 and -3. Before the advent of corticosteroids, therapy was almost fatal. The introduction of high-dose corticosteroid therapy has reduced mortality rates to similar to 10%, but long-term use of steroids can lead to side effects, many of which are severe and associated with significant morbidity. Thus, the major goal of pemphigus therapy has been to reduce the patient's cumulative exposure to systemic corticosteroids. Over the last 2 decades, a range of corticosteroid-sparing immunosuppressive agents have …
Potential Diagnostic Properties of Chest Ultrasound in Thoracic Tuberculosis-A Systematic Review.
2018
Background: Chest ultrasound (CUS) has been shown to be a sensitive and specific imaging modality for pneumothorax, pneumonia, and pleural effusions. However, the role of chest ultrasound in the diagnosis of thoracic tuberculosis (TB) is uncertain. We performed a systematic search in the medical literature to better define the potential role and value of chest ultrasound in diagnosing thoracic tuberculosis. Aim: To describe existing literature with regard to the diagnostic value of chest ultrasound in thoracic tuberculosis. Methods: MEDLINE, EMBASE, and Scopus databases were searched for relevant articles. We included studies that used chest ultrasound for the diagnosis or management of any…
Proliferative effect of acetylcholine on rat trachea epithelial cells is mediated by nicotinic receptors and muscarinic receptors of the M1-subtype.
2003
Acetylcholine (ACh), synthesized in mammalian non-neuronal cells such as epithelial cells of the airways, digestive tract and skin, is involved in the regulation of basic cell functions (so-called non-neuronal cholinergic system). In the present experiments rat trachea epithelial cells have been cultured to study the proliferative effect of applied ACh by [3H]thymidine incorporation. ACh (exposure time 24 h) caused a concentration-dependent increase in cell proliferation with a doubling of the [3H]thymidine incorporation at a concentration of 0.1 microM. This effect was partly reduced by 30 microM tubocurarine and completely abolished by the additional application of 1 microM atropine. The …
Direct Oral Anticoagulants versus Vitamin K Antagonists in Patients Aged 80 Years and Older.
2021
The effectiveness of direct oral anticoagulants (DOAC) is non-inferior to vitamin K antagonists (VKA) to treat atrial fibrillation and venous thromboembolism (VTE). In this cross-sectional study, we compared older persons taking DOACs to those taking VKAs. We included ambulatory individuals ≥80 years, affiliated to Mutualité Sociale Agricole of Burgundy, who were refunded for a medical prescription in September 2017. The demographic conditions, registered chronic diseases (RCD), and number and types of prescribed drugs were compared in the DOAC group and VKA group. Of the 3190 included individuals, 1279 (40%) were prescribed DOACs and 1911 (60%) VKAs. Individuals taking VKAs were older than…