Pharmacokinetics of a single orally administered therapeutic dosage of cyclosporine A in healthy cats

This study aimed to determine a pharmacokinetic profile for a single dosage of cyclosporine A (CsA) clinically used for immunosuppression in cats. Blood-CsA-concentrations were measured before and 1, 2, 4, 6, 8, 12 and 24 h after oral administration of 7 mg/kg body weight (BW) CsA (Atopica® oral solution) to 8 healthy adult cats using high-performance liquid chromatography coupled to mass spectrometry. Pharmacokinetic parameters were calculated using WinNonLin software based on a 1-compartment-model. The median maximum plasma-concentration of 1466 ng/ml (530-2235 ng/ml; minimum-maximum) was reached after 2.0 h (1.0-4.7 h). The area under the curve was 12,568 h x ng/ml (5732-20,820 h x ng/ml) and the apparent total clearance of the drug from plasma was 557 ml/h/kg (336-1221 ml/h/kg). Half-life of absorption into the central compartment was 0.6 h (0.4-2.6 h), half-life of elimination from the central compartment was 4.6 h (1.4-7.5 h).

Current estimates of T cell kinetics in humans

Stable isotope labeling is a generally applicable method of quantifying cell dynamics. Its advent has opened up the way for the quantitative study of T cells in humans. However, the literature is confusing as estimates vary by orders of magnitude between studies. In this short review we aim to explain the reasons for the discrepancies in estimates, clarify which estimates have been superseded and why and highlight the current best estimates. We focus on stable isotope labeling of T cell subsets in healthy humans.

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Current best estimates of the proliferation and production of CD4⁺ and CD8⁺ T cell subsets.

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Explanation of why estimates vary between studies and which estimates have been superseded.

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Discussion of the implications of model choice.

Use of Pistia stratiotes for phytoremediation of water resources contaminated by clomazone

The Pistia stratiotes L. was tested for phytoremediation potential of the compound clomazone in water. Clomazone is a post-emergent herbicide marketed as Gamit^®. Five groups with four samples each were evaluated, a low concentration control (LCC: 37.86 mg L^-1), low concentration treatment (LCT: 38.16 mg L^-1), high concentration control (HCC: 54.71 mg L^-1), high concentration treatment (HCT: 54.33 mg L^-1), and a plant control group (PCG). Plant resistance to clomazone at determined concentrations and their ability to remove the herbicide from water by HPLC over 24 days were evaluated. The results demonstrate that P. stratiotes has high resistance to clomazone exposure and was able to eliminate up to 90% of the herbicide residues during the experimental period. Under dissipation by P. stratiotes in water, clomazone had a halflife of 19.6 days for in the control treatments, LCC and HCC, and 8.0 days in the treatment groups, LCT and HCT. This study indicates that Pistia stratiotes is an effective phytoremediation agent for the herbicide clomazone in water.

Persistence Behavior of Penoxsulam Herbicide in Two Different Soils

Penoxsulam, a new post emergence herbicide is suspected to be toxic to aquatic organisms, crop plants and also to soil microbial community even at low concentrations. Laboratory studies were therefore performed to examine the persistence of, penoxsulam in two different soils at two application rates (0.5 and 1.0 µg g^-1). The study revealed that the dissipation followed the first order kinetics with a half life of 3.48 and 3.57 days at 0.5 µg g^-1 and 4.1 and 4.17 days at 1.0 µg g^-1 fortification rate. Both microbial- and photo-degradation seemed to play a vital role in the dissipation of penoxsulam. The results of LC MS/MS revealed that one minor and five major metabolites were formed during the degradation process of the herbicide and the cleavage of sulfonamide bridge served as the major metabolic pathway.

Effect of Abiotic Factors on Degradation of Imidacloprid

The role of soil moisture, light and pH on imidacloprid dissipation was investigated. A high performance liquid chromatography (HPLC) based method was developed to quantify imidacloprid present in soil with a recovery of more than 82%. Rate of dissipation of imidacloprid from soil was faster in submerged condition compared to field capacity and air dried condition. Imidacloprid dissipated non-significantly between sterile and non-sterile soils, but at field capacity, the dissipation was faster in non-sterile soil compared to sterile soil after 60 days of incubation. Similarly, under submergence, the dissipation of imidacloprid was 66.2% and 79.8% of the initial in sterile and non-sterile soils, respectively. Imidacloprid was rather stable in acidic and neutral water but was prone to photo-degradation. Therefore, imidacloprid degradation will be faster under direct sunlight and at higher soil moisture.

Clevidipine for hypertension treatment in pheochromocytoma surgery

Pheochromocytoma is a catecholamine-producing tumour and laparoscopic adrenalectomy is its treatment of choice. During pneumoperitoneum insufflation and tumour handling there is a high risk of massive catecholamine release and hypertensive crisis. After tumour excision, severe arterial hypotension is a common effect, due to relative vasodilation and the residual effect of antihypertensive drugs. We report the case of a patient with pheochromocytoma who was treated with laparoscopic adrenalectomy. During surgical manipulation there was a sudden hypertensive peak that could be controlled quickly with clevidipine infusion. After tumour resection, clevidipine perfusion was stopped and there were no arterial hypotension episodes. Clevidipine is a new intravenous calcium antagonist with rapid onset of action and short half-life that has no residual effect and does not produce arterial hypotension after tumour resection. For these reasons, it can be a first-choice drug for this kind of surgery.

Serological markers to measure recent changes in malaria at population level in Cambodia

Background

Serological markers for exposure to different Plasmodium species have recently been used in multiplex immunoassays based on the Luminex technology. However, interpretation of the assay results requires consideration of the half-life of specific antibodies against these markers. Therefore, the aim of the present study was to document the half-life of malaria specific serological makers, as well as assessing the sensitivity of these markers to pick up recent changes in malaria exposure.

Methods

A recently developed multiplex immunoassay was used to measure the intensity of antibody (Ab) responses against 19 different Plasmodium specific antigens, covering different human malaria parasites and two vector saliva antigens. Therefore, 8439 blood samples from five cross-sectional surveys in Ratanakiri, Cambodia, were analysed. These involve a random selection from two selected surveys, and an additional set of blood samples of individuals that were randomly re-sampled three, four or five times. A generalized estimating equation model and linear regression models were fitted on log transformed antibody intensity data.

Results

Results showed that most (17/21) Ab-responses are higher in PCR positive than PCR negative individuals. Furthermore, these antibody-responses follow the same upward trend within each age group. Estimation of the half-lives showed differences between serological markers that reflect short- (seasonal) and long-term (year round) transmission trends. Ab levels declined significantly together with a decrease of PCR prevalence in a group of malaria endemic villages.

Conclusion

For Plasmodium falciparum, antibodies against LSA3.RE, GLURP and Pf.GLURP.R2 are most likely to be a reflexion of recent (range from 6 to 8 months) exposure in the Mekong Subregion. PvEBP is the only Plasmodium vivax Ag responding reasonably well, in spite of an estimated Ab half-life of more than 1 year. The use of Ab intensity data rather dichotomizing the continuous Ab-titre data (positive vs negative) will lead to an improved approach for serological surveillance.

Electronic supplementary material

The online version of this article (doi:10.1186/s12936-016-1576-z) contains supplementary material, which is available to authorized users.

Non-target effects of pretilachlor on microbial properties in tropical rice soil

The use of herbicides has been questioned in recent past for their non-target effects. Therefore, we planned to study the effect of pretilachlor on growth and activities of microbes in tropical rice soil under controlled condition at National Rice Research Institute, Cuttack, India. Three pretilachlor treatments, namely, recommended dose at 600 g a.i. ha(-1) (RD), double the recommended dose at 1200 g a.i. ha(-1) (2RD), and ten times of the recommended dose at 6000 g a.i. ha(-1) (10RD) along with control, were imposed. The initial residue (after 2 h of spray) deposits in soil were 0.174, 0.968, and 3.35 μg g(-1) for recommended, double the recommended, and ten times of the recommended doses, respectively. No residue in soil was detected in RD treatment on day 45. The half life values were 16.90, 17.76, and 36.47 days for RD, 2RD, and 10RD treatments, respectively. Application of pretilachlor at 10RD, in general, had significantly reduced the number of bacteria, actinomycetes, fungi, nitrogen fixers, and microbial biomass carbon. Pretilachlor at RD did not record any significant changes in microbial properties compared to control. The results of the present study thus indicated that pretilachlor at RD can be safely used for controlling grassy weeds in rice fields.

Intra-abscess administration of antibiotics through ultrasound-guided percutaneous catheter for the treatment of pyogenic liver abscess

Pyogenic liver abscess is a potentially life-threatening disease. The treatment of a pyogenic liver abscess usually involves ultrasound guided percutaneous drainage because of the poor penetration of the systemic administration of antibiotics inside the abscess. However, a sizable proportion of patients will necessitate surgical interventions, which involves high peri- and post-operative risks. Theoretically, the local instillation of antibiotics inside the pyogenic liver abscess fluid could achieve a high concentration of the antibiotic for a long period of time. This could be especially beneficial for time-dependent bactericidal antibiotics such as beta-lactams, because their bactericidal effectiveness depends on the amount of time that bacteria are exposed to the antibiotic. We are reporting two patients with complicated pyogenic liver abscesses, who were successfully treated with systemic antibiotics and local instillation of meropenem inside the cavities of the abscesses. These cases suggest that the local instillation of the beta-lactam antibiotics could be an effective and a safe strategy for the treatment of pyogenic liver abscesses that cannot be completely drained through an ultrasound guided percutaneous catheter.