Magnitude and persistence of higher estrus-associated temperatures in beef heifers and suckled cows.

Higher estrus-associated temperatures (HEAT) are a hallmark feature in sexually active females. The overarching aim of this study was to characterize the variability, magnitude, and persistence of HEAT in heifers and suckled beef cows as well as identify associated factors when occurring during thermoneutral conditions at the onset of the spring breeding season. In both heifers and cows, estrus was induced using a 7-d controlled internal drug release (CIDR)-PGF2α protocol. Vaginal temperature after prostaglandin F2α administration was recorded every 5 min using a Thermochron iButton affixed to a blank CIDR (containing no progesterone). Estrus was defined as when a heifer first stood to be mounted or when a cow had an Estrotect patch score of 3 or 4. Level of HEAT varied among individual animals. When comparing common HEAT variables using a mixed model with date nested within a year, maximum HEAT (39.9 ±â€…0.1 and 40.0 ±â€…0.1 °C) and duration (15.5 ±â€…0.8 and 15.4 ±â€…0.7) were similar in heifers and cows, respectively. However, the magnitude and persistence of HEAT differed. Total area under the HEAT curve was 117.1 ±â€…13.5 and 158.7 ±â€…12.3 for heifers vs cows, respectively (P = 0.0571). Further, 42.9% of heifers and 49% of cows had maximum HEAT ≥ 40 °C which persisted up to 6.5 and 10 h, respectively. When ambient conditions were predominantly thermoneutral, temperature humidity index had minimal impact on HEAT (mixed model, repeated measures over time). Toward identifying associated factors with different aspects of HEAT using best fit hierarchical linear regression models, baseline vaginal temperature and baseline duration were the most highly associated independent variables. Follicle size, estradiol and progesterone levels, and other available animal-related variables (e.g., age, weight, hair coat score) explained only a small amount of variation in HEAT. In summary, level of HEAT varies in estrus females even under thermoneutral conditions. Because HEAT can persist for an extended time, direct effects on fertility important components are unavoidable. Whether HEAT is a good or bad component of the periovulatory microenvironment is the basis of ongoing and future studies.

When striving for a pregnancy, estrus is a critically important event. Higher estrus-associated temperatures (HEAT) are a hallmark feature in sexually active females. The importance of HEAT for pregnancy, however, remains unclear. Toward filling this critical knowledge gap, efforts described in the current study focused on examining variability of HEAT in individual animals, 2) defining the magnitude and persistence of HEAT, 3) identifying HEAT-associated factors, and 4) examining the similarity of HEAT between heifers and suckled beef cows when occurring at the onset of a spring breeding season. Although the magnitude and persistence of HEAT varied, 42.9% of heifers and 49% of cows reached temperatures ≥ 40 °C which in some cases persisted up to 6.5 and 10 h, respectively. When attempting to identify factors that could explain why some females exhibiting estrus remained hot for an extended time, available animal and environmental data contributed little. Even so, because HEAT can persist for an extended time, direct effects on fertility important components are unavoidable. Whether too much HEAT is good or bad for pregnancy is the basis of ongoing and future studies.

Synthesis and In vitro Efficacy of Tetracyclic Benzothiazepines Against Blood-Stage Plasmodium falciparum and Liver-Stage P. berghei.

OBJECTIVE: A series of novel, substituted tetracyclic benzothiazepines were designed and prepared in an effort to optimize the potency of this chemical class against drug-resistant strains of the malaria parasite. METHODS: Tetracyclic benzothiazepines bearing structural modification at seven distinct positions within the structure were synthesized in Knoevenagel condensation reactions followed by sequential intermolecular thio-Michael and then intramolecular imine formation reactions. Following purification and chemical characterization, the novel compounds were tested for in vitro efficacy against blood-stage P. falciparum and liver-stage P. berghei and also for in vivo efficacy against P. berghei. RESULTS: Benzothiazepines bearing structural modification at the sulfur atom and at the three carbocycles within the molecule were successfully synthesized. The majority of analogs inhibited bloodstage P. falciparum with submicromolar IC50 values. The potency of an 8-methoxy-substituted analog 12 exceeded that of chloroquine in all three P. falciparum strains tested. The parent benzothiazepine 1 possessed liver-stage activity, inhibiting P. berghei sporozoites infecting HepG2 cells with an IC50 of 106.4 nM and an IC90 of 408.9 nM, but failed to enhance the longevity of P. berghei infected mice compared to the controls. Compounds displayed modest toxicity toward HepG2 cells and were tolerated by mice at the highest dose tested, 640 mg/kg/dose once daily for three days. CONCLUSION: The tetracyclic benzothiazepine described, which inhibits P. berghei infected hepatic cells with an IC50 of 106.4 nM, would appear to warrant further investigation. Optimization of ADME properties may be required since the most active analogs are probably excessively lipophilic.

Rescheduling hydrocodone combination products: Impact on patients receiving long-term HCP therapy in a large chain pharmacy-A statewide assessment.

OBJECTIVE: This study aimed to evaluate the rescheduling of hydrocodone combination products (HCPs) from schedule III (CIII) to schedule II (CII) in patients receiving chronic HCP therapy. METHODS: This study was a retrospective cohort analysis of administrative pharmacy data from 118 statewide pharmacies from a retail chain in Tennessee. HCP filling histories were analyzed on patients meeting enrollment criteria from July 1, 2014, to October 1, 2015. The average number of tablets dispensed, daily average of the number of tablets dispensed, and monthly average of morphine milligram equivalents (MME) dispensed were compared for the periods of July 1, 2014, to October 5, 2014 (enrollment period before schedule change) and October 6, 2014, to October 1, 2015 (period following schedule change) using a pooled t test. RESULTS: A total of 4536 patients met the inclusion criteria. Of these 4536 patients, 60.6% were female, and 40.4% were male, with an average age of 58 years (patients included in this study were between the ages of 18 and 99 years). The total number of hydrocodone tablets dispensed in the 12 periods after the schedule change dropped from 467,217 to 259,327, a 45.5% reduction (P < 0.001). Total MME decreased from 4.11 to 2.29 million, a 45.3% reduction (P < 0.001). The number of study participants still receiving an HCP at the end of the study decreased to an average of 2736 across the 12 periods following the schedule change, a 40% reduction. CONCLUSION: HCP dispensing and use decreased among patients receiving chronic opioid treatment from a large corporate statewide community pharmacy in Tennessee after a schedule change from CIII to CII. Monthly sums of total tablets dispensed, average daily tablets dispensed, MME, and average daily MME calculated from July 1, 2014, to October 1, 2015, all experienced statistically significant reductions.

A 24-hour perioperative case study on argatroban use for left ventricle assist device insertion during cardiopulmonary bypass and veno-arterial extracorporeal membrane oxygenation.

A 44-year-old male with ongoing chest pain and left ventricular ejection fraction <20% was transferred from a peripheral hospital with intra-aortic balloon pump placement following a non-ST-elevation myocardial infarction (STEMI). The patient underwent emergent multi-vessel coronary artery bypass grafting requiring veno-arterial (VA) extracorporeal membrane oxygenation (ECMO) on post-operative day (POD)#9 secondary to cardiogenic shock with biventricular failure. Due to clot formation, an oxygenator change-out was necessary shortly after initiation. Following a positive heparin-induced thrombocytopenia (HIT) assay, a total circuit exchange was required to eliminate all heparin coating and argatroban was deemed the anticoagulant of choice due to acute kidney injury. On POD#24, the decision was made to implant a left ventricle assist device (LVAD) as a bridge to heart transplantation. There was difficulty achieving an activated clotting time (ACT) >400 s: multiple argatroban bolus doses were required, along with accelerated up-titration of infusion dosing. Despite maintaining an ACT >484 s, clot formation was observed in the cardiotomy reservoir prior to separation. Subsequently, the patient developed severe disseminated intravascular coagulopathy, with both intra-cardiac and intravascular thrombi, requiring massive transfusion and continuous cell saving due to severe hemorrhage post cardiopulmonary bypass (CPB). The patient received a total of 105 units of plasma, 74 units of packed red cells, 19 units of platelets, 13 bottles of 5% albumin, 6 units of cryoprecipitate and 2 doses of factor VIIa intraoperatively over the course of 24 hours. A total of 19.7 L of washed red blood cells were returned to the patient from the cell saver. With the LVAD in place, the patient developed transfusion-related acute lung injury and acute respiratory distress syndrome with right ventricular dysfunction requiring VA ECMO once again. On POD#30, ECMO was discontinued and the patient was discharged from the intensive care unit (ICU) on POD 66. After a very complex post-operative stay with numerous surgeries and extensive rehabilitation, the patient was discharged home with the LVAD on POD#112.

The potential value of rapid, cloud-enabled onsite testing for the diagnosis of rheumatoid arthritis in the United States.

AIMS: Improvements in information technology have granted the recent development of rapid, cloud-enabled, onsite laboratory testing for rheumatoid arthritis (RA). This study aims to quantify the value to payers of such technologies. MATERIALS AND METHODS: To calculate the value of rapid, cloud-enabled, onsite laboratory testing to diagnose RA relative to traditional, centralized laboratory testing, an Excel-based decision tree model was created that simulated potential cost-savings to payers who cover routine evaluations of RA patients in the US. First, a conceptual framework was created to identify the value components of rapid, cloud-enabled onsite testing. Second, value associated with patient time savings, savings on visit fees, change in treatment costs, and QALY improvements was measured, leveraging existing literature and information from an observational study. Lastly, these value components were combined to estimate the total incremental value accruing to payers per patient-year relative to centralized laboratory testing. RESULTS: Rapid, cloud-enabled, onsite testing is estimated to save one office and 1.81 laboratory visits during the evaluation period for the average patient. Results from an observational study found that rapid, cloud-enabled testing increased the likelihood of completing diagnostic orders from 84.5% to 97%, resulting in an increased probability of early treatment (3.5 percentage points) with disease-modifying anti-rheumatic drugs among patients eligible for treatment. The combined total value was $5,648 per evaluated patient-year. This value is primarily attributed to health benefits of early treatment ($5,048), fewer visit payments ($459), and patient time savings due to fewer office ($216) and laboratory visits ($255). LIMITATIONS AND CONCLUSIONS: Data on the impact of rapid, cloud-enabled, onsite testing on patient health, care delivery, and clinical decision-making is scarce. More robust real-world data would confirm the validity of our model. Rapid, cloud-enabled, onsite testing has the potential to generate significant value to payers.

Microvascular Responsiveness to Pulsatile and Nonpulsatile Flow During Cardiopulmonary Bypass.

BACKGROUND: Pulsatile perfusion may offer microcirculatory advantages over conventional nonpulsatile perfusion during cardiopulmonary bypass (CPB). Here, we present direct visual evidence of microvascular perfusion and vasoreactivity between perfusion modalities. METHODS: A prospective, randomized cohort study of 20 high-risk cardiac surgical patients undergoing pulsatile (n = 10) or nonpulsatile (n = 10) flow during CPB was conducted. Changes in sublingual mucosal microcirculation were assessed with orthogonal polarization spectral imaging along with near-infrared spectroscopic indices of thenar muscle tissue oxygen saturation (StO2) and its recovery during a vascular occlusion test at the following time points: baseline (T0), 30 minutes on CPB (T1), 90 minutes on CPB (T2), 1 hour after CPB (T3), and 24 hours after CPB (T4). RESULTS: On the basis of our scoring scale, a shift in microcirculatory blood flow occurred over time. The pulsatile group maintained normal perfusion characteristics, whereas the nonpulsatile group exhibited deterioration in perfusion during CPB (T2: 74.0% ± 5.6% versus 57.6% ± 5.0%) and after CPB (T3: 76.2% ± 2.7% versus 58.9% ± 5.2%, T4: 85.7% ± 2.6% versus 69.8% ± 5.9%). Concurrently, no important differences were found between groups in baseline StO2 and consumption slope at all time points. Reperfusion slope was substantially different between groups 24 hours after CPB (T4: 6.1% ± 0.6% versus 3.7% ± 0.5%), indicating improved microvascular responsiveness in the pulsatile group versus the nonpulsatile group. CONCLUSIONS: Pulsatility generated by the roller pump during CPB improves microcirculatory blood flow and tissue oxygen saturation compared with nonpulsatile flow in high-risk cardiac surgical patients, which may reflect attenuation of the systemic inflammatory response and ischemia-reperfusion injury.

Use of Optical Imaging Technology in the Validation of a New, Rapid, Cost-Effective Drug Screen as Part of a Tiered In Vivo Screening Paradigm for Development of Drugs To Treat Cutaneous Leishmaniasis.

In any drug discovery and development effort, a reduction in the time of the lead optimization cycle is critical to decrease the time to license and reduce costs. In addition, ethical guidelines call for the more ethical use of animals to minimize the number of animals used and decrease their suffering. Therefore, any effort to develop drugs to treat cutaneous leishmaniasis requires multiple tiers of in vivo testing that start with higher-throughput efficacy assessments and progress to lower-throughput models with the most clinical relevance. Here, we describe the validation of a high-throughput, first-tier, noninvasive model of lesion suppression that uses an in vivo optical imaging technology for the initial screening of compounds. A strong correlation between luciferase activity and the parasite load at up to 18 days postinfection was found. This correlation allows the direct assessment of the effects of drug treatment on parasite burden. We demonstrate that there is a strong correlation between drug efficacy measured on day 18 postinfection and the suppression of lesion size by day 60 postinfection, which allows us to reach an accurate conclusion on drug efficacy in only 18 days. Compounds demonstrating a significant reduction in the bioluminescence signal compared to that in control animals can be tested in lower-throughput, more definitive tests of lesion cure in BALB/c mice and Golden Syrian hamsters (GSH) using Old World and New World parasites.

Whole body perfusion for hybrid aortic arch repair: evolution of selective regional perfusion with a modified extracorporeal circuit.

BACKGROUND: Patients undergoing hybrid aortic arch reconstruction require careful protection of vital organs. We believe that whole body perfusion with tailored dual circuitry may help to achieve optimal patient outcomes. METHODS: Our circuit has evolved from a secondary circuit utilizing a cardioplegia delivery device for lower body perfusion to a dual-oxygenator circuit. This allows individually controlled regional perfusion with ease of switching from secondary to primary circuit for total body flow. The re-design allows for separate flow and temperature regulation with two oxygenators in parallel. All patients underwent a single-stage operation for simultaneous treatment of arch and descending aortic pathology via a sternotomy, using a hybrid frozen elephant trunk technique. RESULTS: We report six consecutive patients undergoing hybrid arch and frozen elephant trunk reconstruction using a dual-oxygenator circuit. Five patients underwent elective surgery and one was emergent. One patient had an acute dissection while three underwent concomitant procedures, including a Ross procedure and two valve-sparing root reconstructions. Three cases were redo sternotomies. The mean pump time was 358 ± 131 min, the aortic cross clamp time 243 ± 135 min, the cardioplegia volume of 33,208 ml ± 16,173, cerebral ischemia 0 min, lower body ischemia 76 ± 34 min and the average lower body perfusion time was 142 min. Two patients did not require any donor blood products. The median intensive care unit (ICU) and hospital lengths of stay (LOS) were two days and 10 days, respectively. The average peak serum lactate on CPB was 7.47 mmol/L and, at admission to the ICU, it was 3.37 mmol/L. Renal and respiratory failure developed in the salvage acute type A dissection patient. No other complications occurred in this series. CONCLUSIONS: Whole body perfusion as delivered through individually controlled dual-oxygenator circuitry allows maximum flexibility for hybrid aortic arch reconstruction. A modified circuit perfusion strategy may help to limit intra-operative metabolic derangements, providing improved clinical outcomes.

Interactive Care Model: A Framework for More Fully Engaging People in Their Healthcare.

Transformation of care delivery requires rethinking the relationship between the person and clinician. The model described provides a process to more fully engage patients in their care. Five encounters include assessing capacity for engagement, exchanging information and choices, planning, determining interventions, and evaluating the effectiveness of engagement interventions. Created by researchers and validated by experts, implications for practice, education, and policy are explored.

Fast Direct Methods for Gaussian Processes.

A number of problems in probability and statistics can be addressed using the multivariate normal (Gaussian) distribution. In the one-dimensional case, computing the probability for a given mean and variance simply requires the evaluation of the corresponding Gaussian density. In the n-dimensional setting, however, it requires the inversion of an n ×n covariance matrix, C, as well as the evaluation of its determinant, det(C). In many cases, such as regression using Gaussian processes, the covariance matrix is of the form C = σ(2) I + K, where K is computed using a specified covariance kernel which depends on the data and additional parameters (hyperparameters). The matrix C is typically dense, causing standard direct methods for inversion and determinant evaluation to require O(n(3)) work. This cost is prohibitive for large-scale modeling. Here, we show that for the most commonly used covariance functions, the matrix C can be hierarchically factored into a product of block low-rank updates of the identity matrix, yielding an O (n log(2) n) algorithm for inversion. More importantly, we show that this factorization enables the evaluation of the determinant det(C), permitting the direct calculation of probabilities in high dimensions under fairly broad assumptions on the kernel defining K. Our fast algorithm brings many problems in marginalization and the adaptation of hyperparameters within practical reach using a single CPU core. The combination of nearly optimal scaling in terms of problem size with high-performance computing resources will permit the modeling of previously intractable problems. We illustrate the performance of the scheme on standard covariance kernels.

Interactive Care Model: A Framework for More Fully Engaging People in Their Healthcare.

Transformation of care delivery requires rethinking the relationship between the person and clinician. The model described provides a process to more fully engage patients in their care. Five encounters include assessing capacity for engagement, exchanging information and choices, planning, determining interventions, and evaluating the effectiveness of engagement interventions. Created by researchers and validated by experts, implications for practice, education, and policy are explored.

Rapid, high-fluence multi-pass q-switched laser treatment of tattoos with a transparent perfluorodecalin-infused patch: A pilot study.

BACKGROUND AND OBJECTIVES: Perfluorodecalin (PFD) has previously been shown to rapidly dissipate the opaque, white micro-bubble layer formed after exposure of tattoos to Q-switched lasers [1]. The current pilot study was conducted to qualitatively determine if the use of a transparent PFD-infused silicone patch would result in more rapid clearance of tattoos than conventional through-air techniques. MATERIALS AND METHODS: Black or dark blue tattoos were divided into two halves in a single-site IRB-approved study with 17 subjects with Fitzpatrick skin types I-III. One half of each tattoo served as its own control and was treated with one pass of a standard Q-switched Alexandrite laser (755 nm). The other half of the tattoo was treated directly through a transparent perfluorodecalin (PFD) infused patch (ON Light Sciences, Dublin, CA). The rapid whitening reduction effect of the Patch routinely allowed three to four laser passes in a total of approximately 5 minutes. Both sides were treated at highest tolerated fluence, but the optical clearing, index-matching, and epidermal protection properties of the PFD Patch allowed significantly higher fluence compared to the control side. Standard photographs were taken at baseline, immediately prior to treatment with the PFD Patch in place, and finally before and after each treatment session. Treatments were administered at 4- to 6-week intervals. RESULTS: In a majority of subjects (11 of 17), tattoos treated through a transparent PFD-infused patch showed more rapid tattoo clearance with higher patient and clinician satisfaction than conventional treatment. In no case did the control side fade faster than the PFD Patch side. No unanticipated adverse events were observed. CONCLUSIONS: Rapid multi-pass treatment of tattoos with highest tolerated fluence facilitated by a transparent PFD-infused patch clears tattoos more rapidly than conventional methods.

Innovation in prediction planning for anterior open bite correction.

This study applies recent advances in 3D virtual imaging for application in the prediction planning of dentofacial deformities. Stereo-photogrammetry has been used to create virtual and physical models, which are creatively combined in planning the surgical correction of anterior open bite. The application of these novel methods is demonstrated through the surgical correction of a case.

Assessment of the prophylactic activity and pharmacokinetic profile of oral tafenoquine compared to primaquine for inhibition of liver stage malaria infections.

BACKGROUND: As anti-malarial drug resistance escalates, new safe and effective medications are necessary to prevent and treat malaria infections. The US Army is developing tafenoquine (TQ), an analogue of primaquine (PQ), which is expected to be more effective in preventing malaria in deployed military personnel. METHODS: To compare the prophylactic efficacy of TQ and PQ, a transgenic Plasmodium berghei parasite expressing the bioluminescent reporter protein luciferase was utilized to visualize and quantify parasite development in C57BL/6 albino mice treated with PQ and TQ in single or multiple regimens using a real-time in vivo imaging system (IVIS). As an additional endpoint, blood stage parasitaemia was monitored by flow cytometry. Comparative pharmacokinetic (PK) and liver distribution studies of oral and intravenous PQ and TQ were also performed. RESULTS: Mice treated orally with three doses of TQ at 5 mg/kg three doses of PQ at 25 mg/kg demonstrated no bioluminescence liver signal and no blood stage parasitaemia was observed suggesting both drugs showed 100% causal activity at the doses tested. Single dose oral treatment with 5 mg TQ or 25 mg of PQ, however, yielded different results as only TQ treatment resulted in causal prophylaxis in P. berghei sporozoite-infected mice. TQ is highly effective for causal prophylaxis in mice at a minimal curative single oral dose of 5 mg/kg, which is a five-fold improvement in potency versus PQ. PK studies of the two drugs administered orally to mice showed that the absolute bioavailability of oral TQ was 3.5-fold higher than PQ, and the AUC of oral TQ was 94-fold higher than oral PQ. The elimination half-life of oral TQ in mice was 28 times longer than PQ, and the liver tissue distribution of TQ revealed an AUC that was 188-fold higher than PQ. CONCLUSIONS: The increased drug exposure levels and longer exposure time of oral TQ in the plasma and livers of mice highlight the lead quality attributes that explain the much improved efficacy of TQ when compared to PQ.

The semantics of time and space: a thematic analysis.

Three empirical studies and one analysis of pre-existing data were performed to determine the everyday meanings of time, a major component of phenomenological analyses of human experience. To this end, participants in Studies 1 and 2 sorted time related words into groups having similar meanings, with these groups then evaluated by hierarchical clustering procedures. Results of Studies 1 and 2 produced similar clustering patterns suggesting it was possible to define the everyday meanings of time in terms of experiences of change and continuity, linear organization, tempo, and boundaries. Results of Study 3 indicated little or no effect on clustering patterns of time words when space words also were included in the set of items to be sorted. Concerns about the size and representativeness of the words used as stimuli in Studies 1, 2 and 3 led to an analysis of over 2,000 words falling under the general heading of Time in Roget's Thesaurus. Results of this analysis revealed that clusters comparable to those obtained in the other three studies also appeared in these data. These results were discussed in terms of their implications for the way in which "invisible" concepts such as time are thought about and used, particularly as related to figurative expression.

First-in-human evaluation of genetically attenuated Plasmodium falciparum sporozoites administered by bite of Anopheles mosquitoes to adult volunteers.

BACKGROUND: Immunization with genetically engineered, attenuated malaria parasites (GAP) that arrest during liver infection confers sterile protection in mouse malaria models. A first generation Plasmodium falciparum GAP (Pf p52(-)/p36(-) GAP) was previously generated by deletion of two pre-erythrocytic stage-expressed genes (P52 and P36) in the NF54 strain. METHODS: A first-in-human, proof-of-concept, safety and immunogenicity clinical trial in six human volunteers was conducted. Exposure consisted of delivery of Pf p52(-)/p36(-) GAP sporozoites via infected Anopheles mosquito bite with a five-bite/volunteer exposure followed by an approximately 200-bite exposure/volunteer one month later. RESULTS: The exposures were well tolerated with mild to moderate local and systemic reactions. All volunteers remained blood stage negative after low dose exposure. Five volunteers remained blood stage negative after high dose exposure. One volunteer developed peripheral parasitemia twelve days after high dose exposure. Together the findings indicate that Pf p52(-)/p36(-) GAP was severely but not completely attenuated. All six volunteers developed antibodies to CSP. Furthermore, IFN-γ responses to whole sporozoites and multiple antigens were elicited in 5 of 6 volunteers, with both CD4 and CD8 cell cytokine production detected. CONCLUSION: Severe attenuation and favorable immune responses following administration of a first generation Pf p52(-)/p36(-) GAP suggests that further development of live-attenuated strains using genetic engineering should be pursued.

An in vivo drug screening model using glucose-6-phosphate dehydrogenase deficient mice to predict the hemolytic toxicity of 8-aminoquinolines.

Anti-malarial 8-aminoquinolines drugs cause acute hemolytic anemia in individuals with glucose-6-phosphate dehydrogenase deficiency (G6PDD). Efforts to develop non-hemolytic 8-aminoquinolines have been severely limited caused by the lack of a predictive in vivo animal model of hemolytic potential that would allow screening of candidate compounds. This report describes a G6PDD mouse model with a phenotype closely resembling the G6PDD phenotype found in the African A-type G6PDD human. These G6PDD mice, given different doses of primaquine, which used as a reference hemolytic drug, display a full array of hemolytic anemia parameters, consistently and reproducibly. The hemolytic and therapeutic indexes were generated for evaluation of hemotoxicity of drugs. This model demonstrated a complete hemolytic toxicity response to another known hemolytic antimalarial drug, pamaquine, but no response to non-hemolytic drugs, chloroquine and mefloquine. These results suggest that this model is suitable for evaluation of selected 8-AQ type candidate antimalarial drugs for their hemolytic potential.

Functional analysis of Plasmodium vivax dihydrofolate reductase-thymidylate synthase genes through stable transformation of Plasmodium falciparum.

Mechanisms of drug resistance in Plasmodium vivax have been difficult to study partially because of the difficulties in culturing the parasite in vitro. This hampers monitoring drug resistance and research to develop or evaluate new drugs. There is an urgent need for a novel method to study mechanisms of P. vivax drug resistance. In this paper we report the development and application of the first Plasmodium falciparum expression system to stably express P. vivax dhfr-ts alleles. We used the piggyBac transposition system for the rapid integration of wild-type, single mutant (117N) and quadruple mutant (57L/58R/61M/117T) pvdhfr-ts alleles into the P. falciparum genome. The majority (81%) of the integrations occurred in non-coding regions of the genome; however, the levels of pvdhfr transcription driven by the P. falciparum dhfr promoter were not different between integrants of non-coding and coding regions. The integrated quadruple pvdhfr mutant allele was much less susceptible to antifolates than the wild-type and single mutant pvdhfr alleles. The resistance phenotype was stable without drug pressure. All the integrated clones were susceptible to the novel antifolate JPC-2067. Therefore, the piggyBac expression system provides a novel and important tool to investigate drug resistance mechanisms and gene functions in P. vivax.

Pulsatile versus nonpulsatile flow during cardiopulmonary bypass: microcirculatory and systemic effects.

BACKGROUND: Controversy exists regarding the optimal perfusion modality during cardiopulmonary bypass (CPB). Here we compare the effects of pulsatile versus nonpulsatile perfusion on microvascular blood flow during and after CPB. METHODS: High-risk cardiac surgical patients were randomly assigned to have pulsatile (n=10) or nonpulsatile (n=10) flow during CPB. The sublingual microcirculation was assessed using orthogonal polarization spectral imaging. Hemodynamic and microvascular variables were obtained after anesthesia (baseline), during CPB, and post-CPB. RESULTS: Compared with baseline, a normal microcirculatory blood flow pattern was accomplished at all time points under pulsatile flow conditions. Peaking 24 hours postoperatively, a higher proportion of normally perfused microvessels occurred under pulsatile versus nonpulsatile flow (56.0%±3.9% vs 33.3%±4.1%; p<0.05). Concurrently, pulsatility resulted in a reduction in the prevalence of pathologic hyper-dynamically perfused vessels (6.0%±3.4% vs 19.6%±8.8%; p<0.05). Leukocyte adherence decreased relative to the nonpulsatile group both during and after CPB. Furthermore, peak lactate levels were reduced under pulsatile flow conditions postoperatively. CONCLUSIONS: Pulsatile perfusion is superior to nonpulsatile perfusion at preserving the microcirculation, which may reflect attenuation of the systemic inflammatory response during CPB. We suggest the implementation of pulsatile flow can better optimize microvascular perfusion, and may lead to improved patient outcomes in high-risk cardiac surgical procedures requiring prolonged CPB time.