Modulating bioreductive drug activity with antivascular agents

Modulation of tumor hypoxia to increase bioreductive drug antitumor activity was investigated. The antivascular agent 5,6-dimethylxanthenone acetic acid (DMXAA) was used in combination studies with the bioreductive drugs Tirapazamine (TPZ) and Mitomycin C (MMC). Blood perfusion studies with DMXAA showed a maximal reduction of 66% in tumor blood flow 4 hours post drug administration. This tumor specific decrease in perfusion was also found to be dose-dependent, with 25 and 30 mg/kg DMXAA yielding greater than 50% reduction in tumor blood flow. Increases in antitumor activity with combination therapy (bioreductive drugs $+$ DMXAA) were significant over individual therapies, suggesting an increased activity due to increased hypoxia induced by DMXAA. Combination studies yielded the following significant tumor growth delays over control: MMC (5mg/kg) $+$ DMXAA (25mg/kg) = 20 days, MMC (2.5mg/kg) $+$ DMXAA (25 mg/kg) = 8 days, TPZ (21.4mg/kg) $+$ DMXAA (17.5mg/kg) = 4 days. The mechanism of interaction of these drugs was investigated by measuring metabolite production and DNA damage. 'Real time' microdialysis studies indicated maximal metabolite production at 20-30 minutes post injection for individual and combination therapies. DNA double strand breaks induced by TPZ $\pm$ DMXAA (20 minutes post injection) were analyzed by pulsed field gel electrophoresis (PFGE). Southern blot analyses and quantification showed TPZ induced DNA double strand breaks, but this effect was not evident in combination studies with DMXAA. Based on these data, combination studies of TPZ $+$ DMXAA showed increased antitumor activity over individual drug therapies. The mechanism of this increased activity, however, does not appear to be due to an increase in TPZ bioreduction at this time point. ^

Detection and management of drug-resistant tuberculosis in HIV-infected patients in lower-income countries.

SETTING Drug resistance threatens tuberculosis (TB) control, particularly among human immunodeficiency virus (HIV) infected persons. OBJECTIVE To describe practices in the prevention and management of drug-resistant TB under antiretroviral therapy (ART) programs in lower-income countries. DESIGN We used online questionnaires to collect program-level data on 47 ART programs in Southern Africa (n = 14), East Africa (n = 8), West Africa (n = 7), Central Africa (n = 5), Latin America (n = 7) and the Asia-Pacific (n = 6 programs) in 2012. Patient-level data were collected on 1002 adult TB patients seen at 40 of the participating ART programs. RESULTS Phenotypic drug susceptibility testing (DST) was available in 36 (77%) ART programs, but was only used for 22% of all TB patients. Molecular DST was available in 33 (70%) programs and was used in 23% of all TB patients. Twenty ART programs (43%) provided directly observed therapy (DOT) during the entire course of treatment, 16 (34%) during the intensive phase only, and 11 (23%) did not follow DOT. Fourteen (30%) ART programs reported no access to second-line anti-tuberculosis regimens; 18 (38%) reported TB drug shortages. CONCLUSIONS Capacity to diagnose and treat drug-resistant TB was limited across ART programs in lower-income countries. DOT was not always implemented and drug supplies were regularly interrupted, which may contribute to the global emergence of drug resistance.

[Helminth control in the adult horse: the need for a re-orientation].

The epidemiological situation of strongyle infections in adult horses in Switzerland is characterized by a strong dominance of small strongyles (Cyathostominae) and an overall low level of egg shedding in the faeces. The prevailing attitude towards anthelmintic therapy considers neither husbandry conditions nor pasture hygiene measures. Instead, calendar-based routine medication, comprising usually 3 to 4 annual treatments, is the typical strategy. Such an approach, however, often results in an excessive administration of anthelmintics. With respect to the continuous spread of drug resistant cyathostomins a change of strategy seems inevitable. A consensus has been agreed on between equine parasitologists and clinicians of the Vetsuisse Faculty in Zurich and Berne to focus on the concept of a selective control approach, based on individual faecal egg counts as the central element. It is now recommended that clinically healthy horses (> 4 y) are treated only when their strongyle egg count is equal to or higher than 200 eggs per gram of faeces. A regular analysis of the strongyle population based on larval cultures, the control of drug efficacy, and quarantine measures for incoming horses are mandatory components of the concept. Recent experiences in several pilot farms have indicated that only 4 % of the McMaster analyses resulted in a deworming treatment. For horses that did not receive any nematicidal anthelmintic during the current season, a "safety" treatment is recommended at the end of the grazing period.

Survival with Newly Diagnosed Metastatic Prostate Cancer in the "Docetaxel Era": Data from 917 Patients in the Control Arm of the STAMPEDE Trial (MRC PR08, CRUK/06/019)

BACKGROUND Prostate cancer (PCa) is the second most common disease among men worldwide. It is important to know survival outcomes and prognostic factors for this disease. Recruitment for the largest therapeutic randomised controlled trial in PCa-the Systemic Therapy in Advancing or Metastatic Prostate Cancer: Evaluation of Drug Efficacy: A Multi-Stage Multi-Arm Randomised Controlled Trial (STAMPEDE)-includes men with newly diagnosed metastatic PCa who are commencing long-term androgen deprivation therapy (ADT); the control arm provides valuable data for a prospective cohort. OBJECTIVE Describe survival outcomes, along with current treatment standards and factors associated with prognosis, to inform future trial design in this patient group. DESIGN, SETTING, AND PARTICIPANTS STAMPEDE trial control arm comprising men newly diagnosed with M1 disease who were recruited between October 2005 and January 2014. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS Overall survival (OS) and failure-free survival (FFS) were reported by primary disease characteristics using Kaplan-Meier methods. Hazard ratios and 95% confidence intervals (CIs) were derived from multivariate Cox models. RESULTS AND LIMITATIONS A cohort of 917 men with newly diagnosed M1 disease was recruited to the control arm in the specified interval. Median follow-up was 20 mo. Median age at randomisation was 66 yr (interquartile range [IQR]: 61-71), and median prostate-specific antigen level was 112 ng/ml (IQR: 34-373). Most men (n=574; 62%) had bone-only metastases, whereas 237 (26%) had both bone and soft tissue metastases; soft tissue metastasis was found mainly in distant lymph nodes. There were 238 deaths, 202 (85%) from PCa. Median FFS was 11 mo; 2-yr FFS was 29% (95% CI, 25-33). Median OS was 42 mo; 2-yr OS was 72% (95% CI, 68-76). Survival time was influenced by performance status, age, Gleason score, and metastases distribution. Median survival after FFS event was 22 mo. Trial eligibility criteria meant men were younger and fitter than general PCa population. CONCLUSIONS Survival remains disappointing in men presenting with M1 disease who are started on only long-term ADT, despite active treatments being available at first failure of ADT. Importantly, men with M1 disease now spend the majority of their remaining life in a state of castration-resistant relapse. PATIENT SUMMARY Results from this control arm cohort found survival is relatively short and highly influenced by patient age, fitness, and where prostate cancer has spread in the body.

Clinically relevant quality measures for risk factor control in primary care: a retrospective cohort study

BACKGROUND Assessment of the proportion of patients with well controlled cardiovascular risk factors underestimates the proportion of patients receiving high quality of care. Evaluating whether physicians respond appropriately to poor risk factor control gives a different picture of quality of care. We assessed physician response to control cardiovascular risk factors, as well as markers of potential overtreatment in Switzerland, a country with universal healthcare coverage but without systematic quality monitoring, annual report cards on quality of care or financial incentives to improve quality. METHODS We performed a retrospective cohort study of 1002 randomly selected patients aged 50-80 years from four university primary care settings in Switzerland. For hypertension, dyslipidemia and diabetes mellitus, we first measured proportions in control, then assessed therapy modifications among those in poor control. "Appropriate clinical action" was defined as a therapy modification or return to control without therapy modification within 12 months among patients with baseline poor control. Potential overtreatment of these conditions was defined as intensive treatment among low-risk patients with optimal target values. RESULTS 20% of patients with hypertension, 41% with dyslipidemia and 36% with diabetes mellitus were in control at baseline. When appropriate clinical action in response to poor control was integrated into measuring quality of care, 52 to 55% had appropriate quality of care. Over 12 months, therapy of 61% of patients with baseline poor control was modified for hypertension, 33% for dyslipidemia, and 85% for diabetes mellitus. Increases in number of drug classes (28-51%) and in drug doses (10-61%) were the most common therapy modifications. Patients with target organ damage and higher baseline values were more likely to have appropriate clinical action. We found low rates of potential overtreatment with 2% for hypertension, 3% for diabetes mellitus and 3-6% for dyslipidemia. CONCLUSIONS In primary care, evaluating whether physicians respond appropriately to poor risk factor control, in addition to assessing proportions in control, provide a broader view of the quality of care than relying solely on measures of proportions in control. Such measures could be more clinically relevant and acceptable to physicians than simply reporting levels of control.

Use of diuretics and risk of incident gout: a population-based case-control study

OBJECTIVE Use of diuretics has been associated with an increased risk of gout. Data on different types of diuretics are scarce. We undertook this study to investigate the association between use of loop diuretics, thiazide or thiazide-like diuretics, and potassium-sparing agents and the risk of developing incident gout. METHODS We conducted a retrospective population-based case-control analysis using the General Practice Research Database established in the UK. We identified case patients who were diagnosed as having incident gout between 1990 and 2010. One control patient was matched to each case patient for age, sex, general practice, calendar time, and years of active history in the database. We used conditional logistic regression to calculate odds ratios (ORs) and 95% confidence intervals (95% CIs), and we adjusted for potential confounders. RESULTS We identified 91,530 incident cases of gout and the same number of matched controls. Compared to past use of diuretics from each respective drug class, adjusted ORs for current use of loop diuretics, thiazide diuretics, thiazide-like diuretics, and potassium-sparing diuretics were 2.64 (95% CI 2.47-2.83), 1.70 (95% CI 1.62-1.79), 2.30 (95% CI 1.95-2.70), and 1.06 (95% CI 0.91-1.23), respectively. Combined use of loop diuretics and thiazide diuretics was associated with the highest relative risk estimates of gout (adjusted OR 4.65 [95% CI 3.51-6.16]). Current use of calcium channel blockers or losartan slightly attenuated the risk of gout in patients who took diuretics. CONCLUSION Use of loop diuretics, thiazide diuretics, and thiazide-like diuretics was associated with an increased risk of incident gout, although use of potassium-sparing agents was not.

Poorly controlled type 2 diabetes mellitus is associated with a decreased risk of incident gout: a population-based case-control study

OBJECTIVE The aim of this study was to explore the risk of incident gout in patients with type 2 diabetes mellitus (T2DM) in association with diabetes duration, diabetes severity and antidiabetic drug treatment. METHODS We conducted a case-control study in patients with T2DM using the UK-based Clinical Practice Research Datalink (CPRD). We identified case patients aged ≥18 years with an incident diagnosis of gout between 1990 and 2012. We matched to each case patient one gout-free control patient. We used conditional logistic regression analysis to calculate adjusted ORs (adj. ORs) with 95% CIs and adjusted our analyses for important potential confounders. RESULTS The study encompassed 7536 T2DM cases with a first-time diagnosis of gout. Compared to a diabetes duration <1 year, prolonged diabetes duration (1-3, 3-6, 7-9 and ≥10 years) was associated with decreased adj. ORs of 0.91 (95% CI 0.79 to 1.04), 0.76 (95% CI 0.67 to 0.86), 0.70 (95% CI 0.61 to 0.86), and 0.58 (95% CI 0.51 to 0.66), respectively. Compared to a reference A1C level of <7%, the risk estimates of increasing A1C levels (7.0-7.9, 8.0-8.9 and ≥9%) steadily decreased with adj. ORs of 0.79 (95% CI 0.72 to 0.86), 0.63 (95% CI 0.55 to 0.72), and 0.46 (95% CI 0.40 to 0.53), respectively. Neither use of insulin, metformin, nor sulfonylureas was associated with an altered risk of incident gout. CONCLUSIONS Increased A1C levels, but not use of antidiabetic drugs, was associated with a decreased risk of incident gout among patients with T2DM.

An Atypical Mitochondrial Carrier That Mediates Drug Action in Trypanosoma brucei

Elucidating the mechanism of action of trypanocidal compounds is an important step in the development of more efficient drugs against Trypanosoma brucei. In a screening approach using an RNAi library in T. brucei bloodstream forms, we identified a member of the mitochondrial carrier family, TbMCP14, as a prime candidate mediating the action of a group of anti-parasitic choline analogs. Depletion of TbMCP14 by inducible RNAi in both bloodstream and procyclic forms increased resistance of parasites towards the compounds by 7-fold and 3-fold, respectively, compared to uninduced cells. In addition, down-regulation of TbMCP14 protected bloodstream form mitochondria from a drug-induced decrease in mitochondrial membrane potential. Conversely, over-expression of the carrier in procyclic forms increased parasite susceptibility more than 13-fold. Metabolomic analyses of parasites over-expressing TbMCP14 showed increased levels of the proline metabolite, pyrroline-5-carboxylate, suggesting a possible involvement of TbMCP14 in energy production. The generation of TbMCP14 knock-out parasites showed that the carrier is not essential for survival of T. brucei bloodstream forms, but reduced parasite proliferation under standard culture conditions. In contrast, depletion of TbMCP14 in procyclic forms resulted in growth arrest, followed by parasite death. The time point at which parasite proliferation stopped was dependent on the major energy source, i.e. glucose versus proline, in the culture medium. Together with our findings that proline-dependent ATP production in crude mitochondria from TbMCP14-depleted trypanosomes was reduced compared to control mitochondria, the study demonstrates that TbMCP14 is involved in energy production in T. brucei. Since TbMCP14 belongs to a trypanosomatid-specific clade of mitochondrial carrier family proteins showing very poor similarity to mitochondrial carriers of mammals, it may represent an interesting target for drug action or targeting.

Contribution of APOBEC3G/F Activity to the Development of Low-Abundance Drug-Resistant HIV-1 variants.

Plasma drug-resistant minority HIV-1 variants (DRMV) increase the risk of virological failure to first-line NNRTI antiretroviral therapy (ART). The origin of DRMVs in ART-naive patients, however, remains unclear. In a large pan-European case-control study investigating the clinical relevance of pre-existing DRMVs using 454 pyrosequencing, the six most prevalent plasma DRMVs detected corresponded to G-to-A nucleotide mutations (V90I, V106I, V108I, E138K, M184I and M230I). Here, we evaluated if such DRMVs could have emerged from APOBEC3G/F activity. Out of 236 ART-naïve evaluated subjects, APOBEC3G/F hypermutation signatures were detected in plasma viruses of 14 (5.9%) individuals. Samples with minority E138K, M184I, and M230I mutations, but not those with V90I, V106I, or V108I were significantly associated with APOBEC3G/F activity (Fisher's p<0.005), defined as presence of >0.5% of sample sequences with an APOBEC3G/F signature. Mutations E138K, M184I and M230I co-occurred in the same sequence as APOBEC3G/F signatures in 3/9 (33%), 5/11 (45%) and 4/8 (50%) of samples, respectively; such linkage was not found for V90I, V106I or V108I. In-frame STOP codons were observed in 1.5% of all clonal sequences; 14.8% of them co-occurred with APOBEC3G/F signatures. APOBEC3G/F-associated E138K, M184I and M230I appeared within clonal sequences containing in-frame STOP codons in 2/3 (66%), 5/5 (100%) and 4/4 (100%) of the samples. In a reanalysis of the parent case-control study, presence of APOBEC3G/F signatures was not associated with virological failure. In conclusion, the contribution of APOBEC3G/F editing to the development of DRMVs is very limited and does not affect the efficacy of NNRTI ART.

Certolizumab treatment during late pregnancy in patients with rheumatic diseases: Low drug levels in cord blood but possible risk for maternal infections. A case series of 13 patients

OBJECTIVE Due to reduction of immune-suppressive drugs, patients with rheumatic diseases can experience an increase in disease activity during pregnancy. In such cases, TNF-inhibitors may be prescribed. However, monoclonal antibodies with the Fc moiety are actively transported across the placenta, resulting in therapeutic drug levels in the newborn. As certolizumab (CZP) lacks the Fc moiety, it may bear a lower risk for the child. METHOD We report a case series of thirteen patients (5 with rheumatoid arthritis and 8 with spondyloarthritis) treated with CZP during late pregnancy to control disease activity. RESULT CZP measured in cord blood of eleven infants ranged between undetectable levels and 1μg/mL whereas the median CZP level of maternal plasma was 32.97μg/mL. Three women developed an infection during the third trimester, of whom one had a severe infection and one had an infection that resulted in a pre-term delivery. During the postpartum period, 6 patients remained on CZP while breastfeeding. CZP levels in the breast milk of two breastfeeding patients were undetectable. CONCLUSION The lack of the active transplacental transfer of CZP gives the possibility to treat inflammatory arthritis during late gestation without potential harm to the newborn. However, in pregnant women treated with TNF-inhibitors and prednisone, attention should be given to the increased susceptibility to infections, which might cause prematurity. CZP treatment can be continued while breastfeeding.

The Akt/PKB pathway is constitutively activated in Theileria-transformed leucocytes, but does not directly control constitutive NF-kappaB activation

The intracellular protozoan parasites Theileria parva and Theileria annulata transform leucocytes by interfering with host cell signal transduction pathways. They differ from tumour cells, however, in that the transformation process can be entirely reversed by elimination of the parasite from the host cell cytoplasm using a specific parasiticidal drug. We investigated the state of activation of Akt/PKB, a downstream target of PI3-K-generated phosphoinositides, in Theileria-transformed leucocytes. Akt/PKB is constitutively activated in a PI3-K- and parasite-dependent manner, as judged by the specific phosphorylation of key residues, in vitro kinase assays and its cellular distribution. In previous work, we demonstrated that the parasite induces constitutive activation of the transcription factor NF-kappaB, providing protection against spontaneous apoptosis that accompanies transformation. In a number of other systems, a link has been established between the PI3-K-Akt/PKB pathway and NF-kappaB activation, resulting in protection against apoptosis. In Theileria-transformed leucocytes, activation of the NF-kappaB and the PI3-K-Akt/PKB pathways are not directly linked. The PI3-K-Akt/PKB pathway does not contribute to the persistent induction of IkappaBalpha phosphorylation, NF-kappaB DNA-binding or transcriptional activity. We show that the two pathways are downregulated with different kinetics when the parasite is eliminated from the host cell cytoplasm and that NF-kappaB-dependent protection against apoptosis is not dependent on a functional PI3-K-Akt/PKB pathway. We also demonstrate that Akt/PKB contributes, at least in part, to the proliferation of Theileria-transformed T cells.

Connecticut Poison Control Center. 2002 and 2003 Annual Report and Poison Exposure Statistics

The Connecticut Poison Control Center (CPCC) at the University of Connecticut Health Center (UCHC) was established in 1957 under Connecticut General Statute 10a- 132. The CPCC’s main responsibility is to provide 24-hour emergency toxicology management consultations for victims of poisoning, and serve as a source for pharmacology and toxicology-related information. The center monitors the epidemiology of human poisoning and provides surveillance for environmental and occupational chemical exposures, drug abuse, and pharmaceutical interactions and adverse effects. The CPCC performs toxicological research, and provides formal toxicology instruction for allied health professionals, as well as professional and consumer poison prevention education. The CPCC is one of 63 nationwide centers certified by the American Association of Poison Control Centers (AAPCC), and the only poison center in the state of Connecticut. The AAPCC establishes standards of care for poisoning and administers the Toxic Exposure Surveillance System (TESS), a national database of poisoning statistics, to which the CPCC is a contributor.

The Making of Optimal and Consistent Policy: An Analytical Framework for Monetary Models

This paper shows that optimal policy and consistent policy outcomes require the use of control-theory and game-theory solution techniques. While optimal policy and consistent policy often produce different outcomes even in a one-period model, we analyze consistent policy and its outcome in a simple model, finding that the cause of the inconsistency with optimal policy traces to inconsistent targets in the social loss function. As a result, the central bank should adopt a loss function that differs from the social loss function. Carefully designing the central bank s loss function with consistent targets can harmonize optimal and consistent policy. This desirable result emerges from two observations. First, the social loss function reflects a normative process that does not necessarily prove consistent with the structure of the microeconomy. Thus, the social loss function cannot serve as a direct loss function for the central bank. Second, an optimal loss function for the central bank must depend on the structure of that microeconomy. In addition, this paper shows that control theory provides a benchmark for institution design in a game-theoretical framework.