Serum Activity (serum + activity)

Distribution by Scientific Domains


Selected Abstracts


Xenobiotic activity in serum and sperm chromatin integrity in European and inuit populations

MOLECULAR REPRODUCTION & DEVELOPMENT, Issue 4 2008
Tanja Krüger
Abstract Lipophilic persistent organic pollutants (POPs) are ubiquitous in the environment and suspected to interfere with hormone activities and reproduction. In previous studies we demonstrated that POP exposure can affect sperm DNA integrity and differences between Inuits and Europeans in sperm DNA integrity and xenobiotic activity were observed. The aim of this study was to investigate possible relations between human sperm chromatin integrity and the xenobiotic serum activity of lipophilic POPs assessed as effects on the estrogen (ER), androgen (AR), and/or aryl hydrocarbon (AhR) receptors. Human sperm chromatin integrity was assessed as DNA fragmentation index (%DFI) and high DNA stainability (%HDS) using the flow cytometric sperm chromatin structure assay (SCSA). Xenobiotic receptor activities were determined using chemically activated luciferase gene expression (CALUX) assay. The study included 53 Greenlandic Inuits and 247 Europeans (Sweden, Warsaw (Poland) and Kharkiv (Ukraine)). A heterogeneous pattern of correlations was found. For Inuits, ER and AhR activities and %DFI were inversely correlated, whereas a positive correlation between AR activity and %DFI was found for Europeans. In contrast, no correlation between receptor activities and %HDS was observed for Inuits but for Europeans positive and negative correlations were observed between ER and AR activities and %HDS, respectively. We suggest that the different patterns of xenobiotic serum activities, in combination with diet associated factors and/or genetics, might be connected to the observed differences in sperm chromatin integrity between the Inuits and Europeans. Mol. Reprod. Dev. 75: 669,680, 2008. © 2007 Wiley-Liss, Inc. [source]


Toxicity in Doberman Pinchers with Ventricular Arrhythmias Treated with Amiodarone (1996,2005)

JOURNAL OF VETERINARY INTERNAL MEDICINE, Issue 1 2009
M.S. Kraus
Background: Asymptomatic Doberman Pinschers with dilated cardiomyopathy (DCM) often die suddenly owing to ventricular tachycardia that degenerates into ventricular fibrillation. A safe and effective antiarrhythmic drug treatment is needed. This will require a large, well-controlled, prospective study. Hypothesis: Amiodarone toxicity is common in Dobermans with occult DCM and ventricular tachyarrhythmias refractory to antiarrhythmia therapy. Infrequent monitoring of hepatic function is inadequate. Frequent monitoring may be useful to determine dogs in which the dosage should be decreased or the drug withdrawn. Methods: Medical records from the University of Georgia and Cornell University were searched for Doberman Pinschers diagnosed with preclinical DCM that received amiodarone for severe ventricular arrhythmias refractory to other antiarrhythmic agents. Echocardiographic data, Holter recording data, hepatic enzyme serum activity, and serum amiodarone concentrations were recorded. The presence of clinical signs of toxicity was recorded. Serum amiodarone concentrations were obtained in some dogs. Results: Reversible toxicity was identified in 10 of 22 (45%) dogs. Conclusion and Clinical Importance: Adverse effects from amiodarone were common and were, in part, dosage related. Patients should be monitored for signs of toxicity and liver enzyme activity should be measured at least monthly. [source]


Efficacy and Toxicosis of VELCAP-C Treatment of Lymphoma in Cats

JOURNAL OF VETERINARY INTERNAL MEDICINE, Issue 1 2008
A.G. Hadden
Background: Lymphoma is the most common malignancy affecting cats. A protocol employing vincristine, l -asparaginase, cyclophosphamide, doxorubicin, and prednisone (VELCAP-S) is effective and well tolerated in dogs with lymphoma. A 24-week variation of this protocol (VELCAP-C) was developed for treatment of cats. Hypothesis: That VELCAP-C will result in survival times for cats with lymphoma that are similar to those obtained when cats are treated with a protocol that includes fewer chemotherapy agents. Animals: Sixty-one cats with lymphoma. Methods: Retrospective study. Outcomes evaluated were response to VELCAP-C therapy, toxicosis, and survival time. The effect of signalment, staging, CBC, and serum chemistry profile and dosage on these outcomes was examined. Results: Six cats (10%) completed the protocol with a median survival of 1189 days. Forty-three percent (23 of 61) of the cats achieved complete response (CR) with a median survival time of 62 days. Cats that required a dose reduction of any drug during induction were more likely to achieve CR. Weight loss and hepatomegaly at diagnosis were negatively associated with response to treatment. Increased lactate dehydrogenase (LDH) serum activity at the time of initial treatment correlated with decreased survival times. Conclusions and Clinical Importance: This multi agent protocol did not provide improved survival over historical data using protocols with fewer agents. Serum LDH activity levels might provide useful prognostic information for cats with lymphoma. [source]


Disposition of oral telithromycin in foals and in vitro activity of the drug against macrolide-susceptible and macrolide-resistant Rhodococcus equi isolates

JOURNAL OF VETERINARY PHARMACOLOGY & THERAPEUTICS, Issue 4 2010
L. H. JAVSICAS
Javsicas, LH., Gigučre, S., Womble, AY. Disposition of oral telithromycin in foals and in vitro activity of the drug against macrolide-susceptible and macrolide-resistant Rhodococcus equi isolates. J. vet. Pharmacol. Therap. doi: 10.1111/j.1365-2885.2009.01151.x. The objectives of this study were to determine the serum and pulmonary disposition of telithromycin in foals and to determine the minimum inhibitory concentration (MIC) of telithromycin against macrolide-susceptible and macrolide-resistant Rhodococcus equi isolates. A single dose of telithromycin (15 mg/kg of body weight) was administered to six healthy 6,10-week-old foals by the intragastric route. Activity of telithromycin was measured in serum, pulmonary epithelial lining fluid (PELF), and bronchoalveolar lavage (BAL) cells using a microbiological assay. The broth macrodilution method was used to determine the MIC of telithromycin, azithromycin, clarithromycin and erythromycin against R. equi. Following intragastric administration, mean ± SD time to peak serum telithromycin activity (Tmax) was 1.75 ± 0.76 h, maximum serum activity (Cmax) was 1.43 ± 0.37 ,g/mL, and terminal half-life (t˝) was 3.81 ± 0.40 h. Telithromycin activity, 4 h postadministration was significantly higher in BAL cells (50.9 ± 14.5 ,g/mL) than in PELF (5.07 ± 2.64 ,g/mL), and plasma (0.84 ± 0.25 ,g/mL). The MIC90 of telithromycin for macrolide-resistant R. equi isolates (8 ,g/mL) was significantly higher than that of macrolide-susceptible isolates (0.25 ,g/mL). The MIC of telithromycin for macrolide-resistant isolates (MIC50 = 4.0 ,g/mL) was significantly lower than that of clarithromycin (MIC50 = 24.0 ,g/mL), azithromycin (MIC50 =256 ,g/mL) and erythromycin (MIC50 = 24 ,g/mL). [source]


Pharmacokinetics of oral doxycycline and concentrations in body fluids and bronchoalveolar cells of foals

JOURNAL OF VETERINARY PHARMACOLOGY & THERAPEUTICS, Issue 3 2007
A. WOMBLE
The objective of this study was to determine the disposition of orally administered doxycycline in foals. Six healthy 4- to 8-week-old foals were used. Doxycycline was administered to each foal via the intragastric (IG) route at dosages of 10 and 20 mg/kg, in a cross-over design. After the first 10 mg/kg dose, five additional doses were administered at 12-h intervals. A microbiological assay was used to measure doxycycline activity in serum, urine, peritoneal fluid, synovial fluid, cerebrospinal (CSF), pulmonary epithelial lining fluid (PELF), and bronchoalveolar (BAL) cells. Following administration at 10 mg/kg, mean ± SD time to peak serum doxycycline activity (tmax) was 3.0 ± 1.2 h, maximum serum activity (Cmax) was 2.54 ± 0.27 ,g/mL, and terminal half-life (t1/2) was 8.5 ± 2.8 h. Administration at a dose of 20 mg/kg resulted in a significantly longer tmax (5.5 ± 1.8 h) as well as a tendency toward higher Cmax (2.89 ± 0.33 ,g/mL) and longer t1/2 (11.9 ± 2.6 h). After multiple IG doses, doxycycline activity in CSF was significantly lower than concurrent serum activity, whereas peritoneal fluid, synovial fluid, and BAL cell doxycycline activity was similar to concurrent serum activity. Doxycycline activity in urine and PELF was significantly higher than that found at other sites. Oral administration at a dosage of 10 mg/kg every 12 h would maintain serum, PELF, and BAL cell activity above the minimum inhibitory concentrations of Rhodococcus equi, , -hemolytic streptococci, and other susceptible bacterial pathogens for the entire dosing interval. [source]


Xenobiotic activity in serum and sperm chromatin integrity in European and inuit populations

MOLECULAR REPRODUCTION & DEVELOPMENT, Issue 4 2008
Tanja Krüger
Abstract Lipophilic persistent organic pollutants (POPs) are ubiquitous in the environment and suspected to interfere with hormone activities and reproduction. In previous studies we demonstrated that POP exposure can affect sperm DNA integrity and differences between Inuits and Europeans in sperm DNA integrity and xenobiotic activity were observed. The aim of this study was to investigate possible relations between human sperm chromatin integrity and the xenobiotic serum activity of lipophilic POPs assessed as effects on the estrogen (ER), androgen (AR), and/or aryl hydrocarbon (AhR) receptors. Human sperm chromatin integrity was assessed as DNA fragmentation index (%DFI) and high DNA stainability (%HDS) using the flow cytometric sperm chromatin structure assay (SCSA). Xenobiotic receptor activities were determined using chemically activated luciferase gene expression (CALUX) assay. The study included 53 Greenlandic Inuits and 247 Europeans (Sweden, Warsaw (Poland) and Kharkiv (Ukraine)). A heterogeneous pattern of correlations was found. For Inuits, ER and AhR activities and %DFI were inversely correlated, whereas a positive correlation between AR activity and %DFI was found for Europeans. In contrast, no correlation between receptor activities and %HDS was observed for Inuits but for Europeans positive and negative correlations were observed between ER and AR activities and %HDS, respectively. We suggest that the different patterns of xenobiotic serum activities, in combination with diet associated factors and/or genetics, might be connected to the observed differences in sperm chromatin integrity between the Inuits and Europeans. Mol. Reprod. Dev. 75: 669,680, 2008. © 2007 Wiley-Liss, Inc. [source]


Transcriptional expression and gelatinolytic activity of matrix metalloproteinases in Henoch,Schonlein purpura

ACTA PAEDIATRICA, Issue 8 2010
N Mahajan
Abstract Aim:, Accelerated extracellular matrix breakdown caused by the increased activity of matrix metalloproteinases (MMPs) has been implicated in several rheumatological disorders and systemic vasculitides, especially Takayasu's arteritis and Kawasaki disease. Therefore, the aim of the present study was to investigate the potential role of MMPs in Henoch,Schonlein purpura (HSP), an acute type of systemic vasculitis in children. Methods:, We studied the activity of MMP-2 and MMP-9 in the sera using gelatin zymography and the transcriptional expression in peripheral blood mononuclear cells using semi-quantitative RT-PCR in 20 patients with HSP in acute and convalescent phase and in 20 healthy children, who were siblings of the subjects with same age group. Results:, All 20 children with HSP showed increased levels of serum activity of MMP-2 and MMP-9 in acute phase as compared with their convalescent phase [MMP-2 (p > 0.05); MMP-9 (p > 0.05)] and their control counterparts [MMP-2 (p < 0.001); MMP-9 (p < 0.001)]. Similarly, transcriptional expression of MMPs was found to be higher in the acute phase of HSP than in convalescent phase [MMP-2 (p < 0.05); MMP-9 (p < 0.001)] and in their healthy controls [MMP-2 (p < 0.001); MMP-9 (p < 0.01)]. Conclusion:, The presence of excessive transcriptional expression and gelatinolytic activity of MMPs may be downstream to the actual aetiopathogenetic factors. [source]