Comparison of radial 4D Flow-MRI with perivascular ultrasound to quantify blood flow in the abdomen and introduction of a porcine model of pre-hepatic portal hypertension.

OBJECTIVES: Objectives of this study were to compare radial time-resolved phase contrast magnetic resonance imaging (4D Flow-MRI) with perivascular ultrasound (pvUS) and to explore a porcine model of acute pre-hepatic portal hypertension (PHTN). METHODS: Abdominal 4D Flow-MRI and pvUS in portal and splenic vein, hepatic and both renal arteries were performed in 13 pigs of approximately 60 kg. In six pigs, measurements were repeated after partial portal vein (PV) ligature. Inter- and intra-reader comparisons and statistical analysis including Bland-Altman (BA) comparison, paired Student's t tests and linear regression were performed. RESULTS: PvUS and 4D Flow-MRI measurements agreed well; flow before partial PV ligature was 322 ± 30 ml/min in pvUS and 297 ± 27 ml/min in MRI (p = 0.294), and average BA difference was 25 ml/min [-322; 372]. Inter- and intra-reader results differed very little, revealed excellent correlation (R 2 = 0.98 and 0.99, respectively) and resulted in BA differences of -5 ml/min [-161; 150] and -2 ml/min [-28; 25], respectively. After PV ligature, PV flow decreased from 356 ± 50 to 298 ± 61 ml/min (p = 0.02), and hepatic arterial flow increased from 277 ± 36 to 331 ± 65 ml/min (p = n.s.). CONCLUSION: The successful in vivo comparison of radial 4D Flow-MRI to perivascular ultrasound revealed good agreement of abdominal blood flow although with considerable spread of results. A model of pre-hepatic PHTN was successfully introduced and acute responses monitored. KEY POINTS: • Radial 4D Flow-MRI in the abdomen was successfully compared to perivascular ultrasound. • Inter- and intra-reader testing demonstrated excellent reproducibility of upper abdominal 4D Flow-MRI. • A porcine model of acute pre-hepatic portal hypertension was successfully introduced. • 4D Flow-MRI successfully monitored acute changes in a model of portal hypertension.

Reelin, an extracellular matrix protein linked to early onset psychiatric diseases, drives postnatal development of the prefrontal cortex via GluN2B-NMDARs and the mTOR pathway.

Defective brain extracellular matrix (ECM) is a factor of vulnerability in various psychiatric diseases such as schizophrenia, depression and autism. The glycoprotein reelin is an essential building block of the brain ECM that modulates neuronal development and participates to the functions of adult central synapses. The reelin gene (RELN) is a strong candidate in psychiatric diseases of early onset, but its synaptic and behavioral functions in juvenile brain circuits remain unresolved. Here, we found that in juvenile reelin-haploinsufficient heterozygous reeler mice (HRM), abnormal fear memory erasure is concomitant to reduced dendritic spine density and anomalous long-term potentiation in the prefrontal cortex. In juvenile HRM, a single in vivo injection with ketamine or Ro25-6981 to inhibit GluN2B-N-methyl-D-aspartate receptors (NMDARs) restored normal spine density, synaptic plasticity and converted fear memory to an erasure-resilient state typical of adult rodents. The functional and behavioral rescue by ketamine was prevented by rapamycin, an inhibitor of the mammalian target of rapamycin pathway. Finally, we show that fear memory erasure persists until adolescence in HRM and that a single exposure to ketamine during the juvenile period reinstates normal fear memory in adolescent mice. Our results show that reelin is essential for successful structural, functional and behavioral development of juvenile prefrontal circuits and that this developmental period provides a critical window for therapeutic rehabilitation with GluN2B-NMDAR antagonists.

Persistence of amygdala gamma oscillations during extinction learning predicts spontaneous fear recovery.

Extinction of auditory fear conditioning induces a temporary inhibition of conditioned fear responses that can spontaneously reappear with the passage of time. Several lines of evidence indicate that extinction learning relies on the recruitment of specific neuronal populations within the basolateral amygdala. In contrast, post-extinction spontaneous fear recovery is thought to result from deficits in the consolidation of extinction memory within prefrontal neuronal circuits. Interestingly, recent data indicates that the strength of gamma oscillations in the basolateral amygdala during auditory fear conditioning correlates with retrieval of conditioned fear responses. In the present manuscript we evaluated the hypothesis that post-extinction spontaneous fear recovery might depend on the maintenance of gamma oscillations within the basolateral amygdala by using single unit and local field potential recordings in behaving mice. Our results indicate that gamma oscillations in the basolateral amygdala were enhanced following fear conditioning, whereas during extinction learning gamma profiles were more heterogeneous despite similar extinction learning rates. Remarkably, variations in the strength of gamma power within the basolateral amygdala between early and late stages of extinction linearly predicted the level of post-extinction spontaneous fear recovery. These data suggest that maintenance of gamma oscillations in the basolateral amygdala during extinction learning is a strong predictive factor of long term spontaneous fear recovery.

Biological characteristics of Anticarsia gemmatalis (Lepidoptera: Noctuidae) for three consecutive generations under different temperatures: understanding the possible impact of global warming on a soybean pest.

Climate changes can affect the distribution and intensity of insect infestations through direct effects on their life cycles. Experiments were carried out during three consecutive generations to evaluate the effect of different temperatures (25°C, 28°C, 31°C, 34°C and 37±1°C) on biological traits of the velvetbean caterpillar Anticarsia gemmatalis Hübner, 1818 (Lepidoptera: Noctuidae). The insects were fed on artificial diet and reared in environmental chambers set at 14 h photophase. The developmental cycle slowed with the increase in the temperature, within the 25°C to 34°C range. Male and female longevities were reduced with an increase in temperature from 25°C to 28°C. Egg viability was highest at 25°C, and the sex ratio was not influenced by temperature, in the three generations. There was no interactive effect between development time and temperature on pupal weight. The results suggested that the increase in the temperature negatively impacted A. gemmatalis development inside the studied temperature range, indicating a possible future reduction of its occurrence on soybean crops, as a consequence of global warming, mainly considering its impact on tropical countries where this plant is cropped. A. gemmatalis was not able to adapt to higher temperatures in a three-generation interval for the studied temperature range. However, a gradual increase and a longer adaptation period may favor insect selection and consequently adaptation, and must be considered in future studies in this area. Moreover, it is important to consider that global warming might turn cold areas more suitable to A. gemmatalis outbreaks. Therefore, more than a future reduction of A. gemmatalis occurrence due to global warming, we might expect changes regarding its area of occurrence on a global perspective.

Effects of mild temperature conditions during dehydration procedures on saffron quality parameters.

BACKGROUND: The dehydration procedure is responsible for saffron sensorial properties: colour, taste and aroma. Changes in the compounds responsible for these characteristics have been studied when dehydration processes at high and low temperature are employed. However, the evolution of these changes at mild temperatures is not available in the current bibliography. In this paper the effect of different mild conditions (18-20 degrees C for 24 h, 40-50 degrees C for 75 min and 55 degrees C for 75 min) applied to 45 saffron samples with the same origin was investigated. RESULTS: Crocetin esters, the compounds responsible for saffron colour, increased their content with no significant differences from other processes when high temperatures (55 degrees C) were used, thus producing a noticeable increment in saffron colouring capability. Similar behaviour was obtained for picrocrocin, the compound responsible for saffron taste, with higher average content at the highest temperature (55 degrees C) but without significant differences with the inferior conditions (40-50 degrees C). However, more volatile compounds were generated, especially safranal,at higher temperatures, e.g. 55 degrees C, during the dehydration procedure. CONCLUSIONS: The results found support the idea for employing mild to high temperatures during the dehydration process of saffron.

Improving thiamine prescribing at an academic hospital network using the computerized provider order entry system: a cohort study.

BACKGROUND: Oral thiamine therapy is frequently prescribed to patients at risk for thiamine deficiency despite recommendations emphasizing the need for high doses of parenteral thiamine to reverse brain thiamine deficits. We evaluated the effect of changes to the computerized provider order entry system on the proportion of prescriptions for parenteral thiamine treatment (primary outcome) and dosages prescribed (secondary outcome) within our academic hospital network. METHODS: We obtained data from the pharmacy information system recording thiamine prescribed to inpatients at University Health Network hospitals (Toronto, Ontario) before (Jan. 1, 2010, to Dec. 31, 2011) and after (Nov. 21, 2013, to Apr. 30, 2017) changes to the computerized provider order entry system promoting the use of higher dosages (≥ 200 mg) of parenterally administered thiamine. Patients receiving thiamine as part of total parenteral nutrition were excluded from analyses, as thiamine prescribing was automated and unlikely to be affected by the intervention. RESULTS: A total of 6105 thiamine prescriptions were written for 2907 patients before the intervention and 12 787 thiamine prescriptions for 8032 patients after the intervention. The proportion of prescriptions for parenteral treatment increased from 55.5% (3386/6105) to 92.5% (11 829/12 787) after the intervention (p < 0.001). Increases in prescribing of parenteral thiamine treatment were sustained or enhanced across the 3.4-year observation period and were realized across all hospital services. Prescriptions for higher dosages of thiamine increased from 1.1% (65/6105) to 61.4% (7845/12 787) after the intervention (p < 0.001). INTERPRETATION: Changes to the computerized provider order entry system were associated with sustained increases in the proportion of prescriptions for high-dose parenteral thiamine therapy. Similar approaches may be leveraged to align prescriber behaviour with well-accepted practice parameters in other areas of medicine.

The Occipital Emissary Vein: A Possible Marker for Pseudotumor Cerebri.

BACKGROUND AND PURPOSE: Transverse sinus stenosis can lead to pseudotumor cerebri syndrome by elevating the cerebral venous pressure. The occipital emissary vein is an inconstant emissary vein that connects the torcular herophili with the suboccipital veins of the external vertebral plexus. This retrospective study compares the prevalence and size of the occipital emissary vein in patients with pseudotumor cerebri syndrome with those in healthy control subjects to determine whether the occipital emissary vein could represent a marker of pseudotumor cerebri syndrome. MATERIALS AND METHODS: The cranial venous system of 46 adult patients with pseudotumor cerebri syndrome (group 1) was studied on CT venography images and compared with a group of 92 consecutive adult patients without pseudotumor cerebri syndrome who underwent venous assessment with gadolinium-enhanced 3D-T1 MPRAGE sequences (group 2). The presence of an occipital emissary vein was assessed, and its proximal (intraosseous) and distal (extracranial) maximum diameters were measured and compared between the 2 groups. Seventeen patients who underwent transverse sinus stent placement had their occipital emissary vein diameters measured before and after stent placement. RESULTS: Thirty of 46 (65%) patients in group 1 versus 29/92 (31.5%) patients in group 2 had an occipital emissary vein (P < .001). The average proximal and distal occipital emissary vein maximum diameters were significantly larger in group 1 (2.3 versus 1.6 mm, P <.005 and 3.3 versus 2.3 mm, P < .001). The average maximum diameters of the occipital emissary vein for patients who underwent transverse sinus stent placement were larger before stent placement than after stent placement: 2.6 versus 1.8 mm proximally (P < .06) and 3.7 versus 2.6 mm distally (P < .005). CONCLUSIONS: Occipital emissary veins are more frequent and larger in patients with pseudotumor cerebri syndrome than in healthy subjects, a finding consistent with their role as collateral venous pathway in transverse sinus stenosis. A prominent occipital emissary vein is an imaging sign that should raise the suspicion of pseudotumor cerebri syndrome.

Metformin-associated hyperlactacidaemia acidosis: Diagnosis rate in standard clinical practice and its relationship with renal failure. / Acidosis con hiperlactacidemia por metformina: frecuencia de su diagnóstico en la práctica clínica habitual y relación con la insuficiencia renal.

BACKGROUND AND OBJECTIVES: Observational study on the difference between the number of cases of acidosis with hyperlactacidaemia suspected of being caused by metformin diagnosed in standard clinical practice and the incidence of this condition according to the datasheet. The study also explored the relationship between renal function and metformin-associated hyperlactacidaemia acidosis. PATIENTS: We identified cases of acidosis between 2013 and 2014 by analysing the minimum basic data set and laboratory requests. We selected patients who presented venous lactate levels >2.7 mmol/L at the time they were treated and for whom the use of outpatient metformin was confirmed. The causal relationship with metformin was independently evaluated by several researchers. The incident cases were calculated based on the number of patients who had been dispensed a drug containing metformin during the same period in the study area. RESULTS: We identified 476 cases of acidosis. Metformin was suspected of causing the condition of acidosis with hyperlactacidaemia in 20 of these cases, which represents an incidence rate of 6.57/10,000 patients. Eighty-five percent of the cases presented acute renal failure. CONCLUSIONS: The apparent incidence of acidosis with hyperlactacidaemia in patients treated with metformin is greater than that established in the datasheet (<1/10,000). The onset of metformin-associated hyperlactacidaemia acidosis is related to acute renal impairment.

Effect of Recombinant Activated Coagulation Factor VII on Hemorrhage Expansion Among Patients With Spot Sign-Positive Acute Intracerebral Hemorrhage: The SPOTLIGHT and STOP-IT Randomized Clinical Trials.

Importance: Intracerebral hemorrhage (ICH) is a devastating stroke type that lacks effective treatments. An imaging biomarker of ICH expansion-the computed tomography (CT) angiography spot sign-may identify a subgroup that could benefit from hemostatic therapy. Objective: To investigate whether recombinant activated coagulation factor VII (rFVIIa) reduces hemorrhage expansion among patients with spot sign-positive ICH. Design, Setting, and Participants: In parallel investigator-initiated, multicenter, double-blind, placebo-controlled randomized clinical trials in Canada ("Spot Sign" Selection of Intracerebral Hemorrhage to Guide Hemostatic Therapy [SPOTLIGHT]) and the United States (The Spot Sign for Predicting and Treating ICH Growth Study [STOP-IT]) with harmonized protocols and a preplanned individual patient-level pooled analysis, patients presenting to the emergency department with an acute primary spontaneous ICH and a spot sign on CT angiography were recruited. Data were collected from November 2010 to May 2016. Data were analyzed from November 2016 to May 2017. Interventions: Eligible patients were randomly assigned 80 µg/kg of intravenous rFVIIa or placebo as soon as possible within 6.5 hours of stroke onset. Main Outcomes and Measures: Head CT at 24 hours assessed parenchymal ICH volume expansion from baseline (primary outcome) and total (ie, parenchymal plus intraventricular) hemorrhage volume expansion (secondary outcome). The pooled analysis compared hemorrhage expansion between groups by analyzing 24-hour volumes in a linear regression model adjusted for baseline volumes, time from stroke onset to treatment, and trial. Results: Of the 69 included patients, 35 (51%) were male, and the median (interquartile range [IQR]) age was 70 (59-80) years. Baseline median (IQR) ICH volumes were 16.3 (9.6-39.2) mL in the rFVIIa group and 20.4 (8.6-32.6) mL in the placebo group. Median (IQR) time from CT to treatment was 71 (57-96) minutes, and the median (IQR) time from stroke onset to treatment was 178 (138-197) minutes. The median (IQR) increase in ICH volume from baseline to 24 hours was small in both the rFVIIa group (2.5 [0-10.2] mL) and placebo group (2.6 [0-6.6] mL). After adjustment, there was no difference between groups on measures of ICH or total hemorrhage expansion. At 90 days, 9 of 30 patients in the rFVIIa group and 13 of 34 in the placebo group had died or were severely disabled (P = .60). Conclusions and Relevance: Among patients with spot sign-positive ICH treated a median of about 3 hours from stroke onset, rFVIIa did not significantly improve radiographic or clinical outcomes. Trial Registration: ClinicalTrials.gov identifier: NCT01359202 and NCT00810888.

Multi-residue contaminants and pollutants analysis in saffron spice by stir bar sorptive extraction and gas chromatography-ion trap tandem mass spectrometry.

A method for the simultaneous determination of 46 semi-volatile organic contaminants and pollutants in saffron has been developed for the first time using a stir bar sorptive extraction technique and thermal desorption in combination with gas chromatography-ion trap tandem mass spectrometry. The analytical method proposed was easy, rapid and sensitive and showed good linearity, accuracy, repeatability and reproducibility over the concentration range tested. Moreover, the correlation coefficients were higher than 0.98 for all target compounds and detection limits were lower than 1 microg/kg except for simazine. The present method was also applied for the analysis of trace contaminants in saffron samples.

Molecular mechanisms of membrane polarity in renal epithelial cells.

Exciting discoveries in the last decade have cast light onto the fundamental mechanisms that underlie polarized trafficking in epithelial cells. It is now clear that epithelial cell membrane asymmetry is achieved by a combination of intracellular sorting operations, vectorial delivery mechanisms and plasmalemma-specific fusion and retention processes. Several well-defined signals that specify polarized segregation, sorting, or retention processes have, now, been described in a number of proteins. The intracellular machineries that decode and act on these signals are beginning to be described. In addition, the nature of the molecules that associate with intracellular trafficking vesicles to coordinate polarized delivery, tethering, docking, and fusion are also becoming understood. Combined with direct visualization of polarized sorting processes with new technologies in live-cell fluorescent microscopy, new and surprising insights into these once-elusive trafficking processes are emerging. Here we provide a review of these recent advances within an historically relevant context.

Genome-wide association study of immunoglobulin light chain amyloidosis in three patient cohorts: comparison with myeloma.

Immunoglobulin light chain (AL) amyloidosis is characterized by tissue deposition of amyloid fibers derived from immunoglobulin light chain. AL amyloidosis and multiple myeloma (MM) originate from monoclonal gammopathy of undetermined significance. We wanted to characterize germline susceptibility to AL amyloidosis using a genome-wide association study (GWAS) on 1229 AL amyloidosis patients from Germany, UK and Italy, and 7526 healthy local controls. For comparison with MM, recent GWAS data on 3790 cases were used. For AL amyloidosis, single nucleotide polymorphisms (SNPs) at 10 loci showed evidence of an association at P<10-5 with homogeneity of results from the 3 sample sets; some of these were previously documented to influence MM risk, including the SNP at the IRF4 binding site. In AL amyloidosis, rs9344 at the splice site of cyclin D1, promoting translocation (11;14), reached the highest significance, P=7.80 × 10-11; the SNP was only marginally significant in MM. SNP rs79419269 close to gene SMARCD3 involved in chromatin remodeling was also significant (P=5.2 × 10-8). These data provide evidence for common genetic susceptibility to AL amyloidosis and MM. Cyclin D1 is a more prominent driver in AL amyloidosis than in MM, but the links to aggregation of light chains need to be demonstrated.

Efficacy and safety of valsartan, an angiotensin II receptor antagonist, in hypertension after renal transplantation: a randomized multicenter study.

BACKGROUND: The prevalence of posttransplant hypertension is high, and it appears to be a major risk factor for graft and patient survival. The aim of this study was to assess the efficacy and safety of valsartan, an angiotensin-receptor blocker (ARB), in the treatment of posttransplant hypertension. METHODS: A multinational, multicenter, prospective, randomized, double-blind, placebo-controlled study was performed on the treatment of hypertension (systolic blood pressure [BP] >/= 140 and/or diastolic BP >/= 90 mm Hg) in adult cyclosporin-treated renal transplant recipients randomized to receive either valsartan (80 mg once daily) or a matching placebo for 8 weeks. After the first 4 weeks, furosemide 20 mg twice daily was added on a open basis if systolic BP remained >/= 130 mm Hg and/or diastolic BP remained >/= 85 mm Hg. RESULTS: One hundred fifteen (valsartan = 57, placebo = 58) uncontrolled hypertensive patients despite monotherapy for hypertension, other than angiotensin-converting enzyme inhibitor or ARB, were randomized. In the valsartan group, significant decreases were seen in systolic BP (from 153 +/- 11 to 140.9 +/- 18.35 mm Hg at 4 weeks, and 136.5 +/- 15 mm Hg at 8 weeks) and diastolic BP (from 93 +/- 9 to 85.2 +/- 11.28 mm Hg at 4 weeks, and 83.8 +/- 9.2 mm Hg at 8 weeks). There was no significant change in the placebo group. In the valsartan group, a statistically but not clinically significant reduction was observed in the mean hemoglobin concentration (12.9 +/- 1.6 g/dL versus 13.8 +/- 1.6 g/dL at 4 weeks, P < .01; and 12.3 +/- 1.6 versus 13.8 +/- 1.7 at 8 weeks; P < .001) as well as a significant increase in serum potassium (4.4 +/- 0.5 mmol/L versus 4.1 +/- 0.4 mmol/L at 4 weeks, P < .01) vs placebo. CONCLUSIONS: Valsartan is effective in the treatment of posttransplant hypertension and is well tolerated.

Autotaxin (ATX), a potent tumor motogen, augments invasive and metastatic potential of ras-transformed cells.

Autotaxin (ATX), an exo-nucleotide pyrophosphatase and phosphodiesterase, was originally isolated as a potent stimulator of tumor cell motility. In order to study whether ATX expression affects motility-dependent processes such as invasion and metastasis, we stably transfected full-length ATX cDNA into two non-expressing cell lines, parental and ras-transformed NIH3T3 (clone7) cells. The effect of ATX secretion on in vitro cell motility was variable. The ras-transformed, ATX-secreting subclones had enhanced motility to ATX as chemoattractant, but there was little difference in the motility responses of NIH3T3 cells transfected with atx, an inactive mutant gene, or empty vector. In MatrigelTM invasion assays, all subclones, which secreted enzymatically active ATX, demonstrated greater spontaneous and ATX-stimulated invasion than appropriate controls. This difference in invasiveness was not caused by differences in gelatinase production, which was constant within each group of transfectants. In vivo studies with athymic nude mice demonstrated that injection of atx-transfected NIH3T3 cells resulted in a weak tumorigenic capacity with few experimental metastases. Combination of ATX expression with ras transformation produced cells with greatly amplified tumorigenesis and metastatic potential compared to ras-transformed controls. Thus, ATX appears to augment cellular characteristics necessary for tumor aggressiveness.

Influence of chronic kidney disease development and renin-angiotensin system inhibition on cardiovascular prognosis.

Recently published guidelines recognize the relevance of the development of chronic kidney disease in the stratification of risk of the hypertensive patient. Adequate assessment of renal function, including estimation of glomerular filtration rate, is mandatory in order to ensure an adequate evaluation of global cardiovascular risk in the hypertensive patient. The presence of subtle elevations of serum creatinine concentrations is a potent predictor of a poor cardiovascular prognosis. Clustering of associated risk factors seems to justify the elevated cardiovascular risk observed in patients with essential hypertension and mild renal function derangement. Chronic kidney disease is associated with a significant increase in cardiovascular risk attributable to the simultaneous existence of other risk factors related to the metabolic syndrome. The inhibition of the effects of angiotensin II is necessary to ensure the best degree of renal protection. It has demonstrated to improve the long-term renal outcome of patients with nephrosclerosis and to reduce the appearance of cardiovascular complications in high risk patients The high prevalence of chronic kidney disease in the general and in the hypertensive populations forces the recognition of its relevance and the need for an integrative therapeutic approach to protect simultaneously renal and cardiovascular systems.

Correlations of smoothness index and trough-to-peak ratio with left ventricular mass index changes induced by lercanidipine in hypertensive patients. A pilot trial.

AIM: The aim of this study was to determine the correlation of changes in left ventricular mass, with changes in office blood pressure (BP) and in 24-h ambulatory (ABP), with the trough-to-peak (T/P) ratio and with the smoothness index (SI), as induced by antihypertensive treatment with lercanidipine. METHODS: This was done through an observational, prospective, open, non-comparative, single centre, pilot study in patients naïve to antihypertensive therapy. All patients were treated with lercanidipine 10-20 mg/day plus hydrochlorothiazide 12.5-25 mg/day if treated BP exceeded an arbitrarily defined safety level (>160/100 mmHg) after 1 month on monotherapy. ABP monitoring was repeated after 1 month and after 6 months. Two-dimensional mode echocardiography was performed twice, at the beginning and end of the study. Seventeen patients were included in the final analysis (aged 45.8 +/- 10.7 years, 35% women). RESULTS: Treatment-induced changes in left ventricular mass index (LVMI) were not found to correlate neither with changes in office BP, with changes in ABP values, nor with T/P. However, a significant correlation was found between LVMI changes and SI at 6 months (r=0.50, P=0.039). CONCLUSION: The results of this study suggest that the SI has a higher predictive value, compared to other BP-derived parameters, for treatment-induced LVMI changes, in hypertensive patients treated with lercanidipine.

Thiamine prescribing practices within university-affiliated hospitals: a multicenter retrospective review.

BACKGROUND: Patients with suspected thiamine deficiency should receive treatment with parenteral thiamine to achieve the high serum thiamine levels necessary to reverse the effects of deficiency and to circumvent problems with absorption common in the medically ill. OBJECTIVE: To quantify rates of parenteral administration of thiamine across university-affiliated hospitals and to identify factors associated with higher rates of parenteral prescribing. DESIGN: Multicenter, retrospective observational study of thiamine prescriptions. METHODS: Prescriptions for thiamine were captured from computerized pharmacy information systems across participating centers, providing information concerning dose, route, frequency, and duration of thiamine prescribed from January 2010 to December 2011. SETTING: Fourteen university-affiliated tertiary care hospitals geographically distributed across Canada, including 48,806 prescriptions for thiamine provided to 32,213 hospitalized patients. RESULTS: Parenteral thiamine accounted for a statistically significant majority of thiamine prescriptions (57.6%, P < 0.001); however, oral thiamine constituted a significant majority of the total doses prescribed (68.4%, z = 168.9; P < 0.001). Protocols prioritizing parenteral administration were associated with higher rates of parenteral prescribing (61.3% with protocol, 45.8% without protocol; P < 0.001). Patients admitted under psychiatry services were significantly more likely to be prescribed oral thiamine (P < 0.001). CONCLUSIONS: Although parenteral thiamine accounted for a statistically significant majority of prescriptions, oral thiamine was commonly prescribed within academic hospitals. Additional strategies are needed to promote parenteral thiamine prescribing to patients with suspected thiamine deficiency.

The natriuretic effect of nifedipine gastrointestinal therapeutic system remains despite the presence of mild-to-moderate renal failure.

BACKGROUND: Calcium channel blockers facilitate the renal excretion of sodium and this effect is maintained during chronic administration of these drugs. However, it is unknown whether this natriuretic effect remains despite the presence of a decreased renal function. OBJECTIVE: To compare the natriuretic capacity of nifedipine gastrointestinal therapeutic system (GITS) and lisinopril in patients with mild-to-moderate chronic renal failure. METHODS: An open-label, randomized, comparative study was conducted to compare the natriuretic capacity of nifedipine GITS and lisinopril in the presence of mild-to-moderate renal failure (creatinine clearance 30-80 ml/min). After a wash-out period of 4 weeks an intravenous saline infusion (30 ml/kg of body weight of isotonic saline in 4 h) was performed and repeated after 4 weeks of active therapy. Two sex- and age-matched groups of hypertensive patients (n = 25) were included in the study. Renal failure was diagnosed as secondary to nephrosclerosis in all the patients. RESULTS: A significant increase in the renal capacity to excrete the sodium load was observed in patients receiving nifedipine GITS (n = 11) but not in those taking lisinopril (n = 13). Both drugs controlled blood pressure to a similar extent. No changes were observed in body weight, glomerular filtration rate and renal plasma flow (measured as inulin and paraaminohippurate clearances). A significant drop was observed in urinary albumin excretion after lisinopril, but not after nifedipine. Heart rate was higher in nifedipine group. CONCLUSION: The natriuretic capacity of nifedipine GITS remains despite the presence of mild-to-moderate chronic renal failure. Such an effect takes place in the absence of changes in renal hemodynamics, suggesting that it is caused by a direct tubular effect.