Metabolic disturbances potentially attributable to clogging during continuous renal replacement therapy.

BACKGROUND: Clogging is characterized by a progressive impairment of transmembrane patency in renal replacement devices and occurs due to obstruction of pores by unknown molecules. If citrate-based anti-coagulation is used, clogging can manifest as a metabolic alkalosis accompanied by hypernatremia and hypercalcemia, primarily a consequence of Na3Citrate infusion. An increased incidence of clogging has been observed during the COVID-19 pandemic. However, precise factors contributing to the formation remain uncertain. This investigation aimed to analyze its incidence and assessed time-varying trajectories of associated factors in critically ill patients on continuous renal replacement therapy (CRRT). METHODS: In this retrospective, single-center data analysis, we evaluated COVID-19 patients undergoing CRRT and admitted to critical care between March 2020 and December 2021. We assessed the proportional incidence of clogging surrogates in the overall population and subgroups based on the specific CRRT devices employed at our institution, including multiFiltrate (Fresenius Medical Care) and Prismaflex System (Baxter). Moderate and severe clogging were defined as Na > 145 or ≥ 150 mmol/l and HCO3- > 28.0 or ≥ 30 mmol/l, respectively, with a total albumin-corrected calcium > 2.54 mmol/l. A mixed effect model was introduced to investigate factors associated with development of clogging. RESULTS: Fifty-three patients with 240 CRRT runs were analyzed. Moderate and severe clogging occurred in 15% (8/53) and 19% (10/53) of patients, respectively. Twenty-seven percent (37/136) of CRRTs conducted with a multiFiltrate device met the criteria for clogging, whereas no clogging could be observed in patients dialyzed with the Prismaflex System. Occurrence of clogging was associated with elevated triglyceride plasma levels at filter start (p = 0.013), amount of enteral nutrition (p = 0.002) and an increasing white blood cell count over time (p = 0.002). CONCLUSIONS: Clogging seems to be a frequently observed phenomenon in critically ill COVID-19 patients. The presence of hypertriglyceridemia, combined with systemic inflammation, may facilitate the development of an impermeable secondary membrane within filters, thereby contributing to compromised membrane patency.

Thromboembolism, Bleeding, and Mortality Incidence of Direct Oral Anticoagulants Versus Warfarin Postbariatric Surgery.

BACKGROUND: There is no randomized controlled trial comparing direct oral anticoagulants (DOACs) and warfarin following bariatric surgery to date. The mortality, thromboembolism, and bleeding risk of DOACs in comparison with warfarin following bariatric surgery remains unclear. We aimed to provide a clinical comparison between DOACs and warfarin for these 3 prespecified outcomes. METHODS: A systematic literature search was performed on November 10, 2019, using PubMed, Embase, clinicaltrial.gov, and Cochrane databases. Studies with adult patients who were on either warfarin or DOACs following bariatric surgery and reported the incidence of thromboembolism, bleeding, or mortality were included. Pooled incidence for these prespecified outcomes and its 95% confidence interval (CI) were calculated for each drug separately using the random-effects model, along with a nonadjusted P value comparing the 2 subgroups. RESULTS: A total of 11 studies (805 patients) were included. Comparing DOACs to warfarin, the following pooled incidences were observed for mortality (DOACs: 3.0%; 95% CI 0.4%-18.6% versus warfarin: 1.5%; 95% CI 0.8%-2.9%; P value comparing the 2 subgroups = .38), thromboembolism (DOACs: 4.9%; 95% CI 1%-21.1% versus warfarin: 1.5%; 95% CI 0.8%-2.9%; P value = .18), and bleeding (DOACs: 3.9%; 95% CI 0.7%-18.2% versus warfarin: 11.3%; 95% CI 5.7%-21.4%; P value = .23). CONCLUSION: The results of our meta-analysis remain hypothesis-generating, providing rationale for future randomized controlled trial design or well-designed comparative observational studies. Currently, it does not support the change in the current recommendation from warfarin to DOACs following bariatric surgery.

In Vitro Propagation of Isoëtes sabatina (Isoetaceae): A Key Conservation Challenge for a Critically Endangered Quillwort.

Isoëtes sabatina is an aquatic quillwort endemic to Italy. It is one of the rarest quillworts in Europe, and is critically endangered due to restricted range and to the continuous decline of both population and habitat quality. This study aims to develop an optimized protocol to reproduce and grow I. sabatina sporelings. Mature and immature megaspores were mixed with mature microspores to evaluate the influence of the developmental stage on germination and sporeling development. Two substrates, distilled water and water-agar medium, were tested for germination and sporeling emergence, and three substrates, sand, lake sediment and water-agar, were tested for transplants. A high percentage of megaspore germination (a total of 79.1%) was obtained in both substrates, higher for mature than immature spores. A total of 351 sporelings were produced in distilled water and water-agar cultures, with similar percentages (64.5% and 69.6%, respectively). The development stage of the megaspores affected both germination and sporeling development. Sporeling emergence showed significantly higher percentages in mature megaspores than immature ones (69.6% vs. 11.6%, respectively), with 85% of germinated spores developing sporelings. Only transplants over water-agar medium were successful. This protocol could be useful for the propagation of sporelings as the key step towards the planning of in situ actions to save this Mediterranean quillwort from extinction.

The 6-D Model of National Culture as a Tool to Examine Cultural Interpretation of Migration Trauma-Related Dissociative Disorder: A Case Series.

Dissociative experiences are common in traumatized individuals who can use dissociation as a psychological escape from emotional and physical distress associated with overwhelming traumatic events. Traumatic experiences and the cultural interpretation of trauma-related symptoms often serve to explain the wide range of dissociative phenomenology; in fact, dissociation is a complex and ubiquitous construct present in a variety of mental disorders. The Six-Dimensions Model of National Culture has been used as a tool to compare patients' different cultural background that could have accounted for the different clinical manifestations. This paper reports three clinical cases in which the focus of interest is represented by the dissociative alterations of consciousness, as a response to trauma, specifically related to migration, and their correlation with cultural environment. The study shows as Hofstede's model has been used for the first time as a tool to explain how different cultural background could shape clinical manifestations.

Inhibition of PAR-1 Receptor Signaling by Enoxaparin Reduces Cell Proliferation and Migration in A549 Cells.

BACKGROUND/AIM: Low-molecular weight heparins (LMWHs) may possess putative antitumoral properties; however, the underlying mechanism(s) remains elusive. We evaluated the antiproliferative and antimigratory effects of enoxaparin (a LMWH) in lung adenocarcinoma A549 cells, and assessed the possible mechanism involved, and the effect on doxorubicin's efficacy. MATERIALS AND METHODS: Proliferation and migration were evaluated using BrdU and transwell assays, respectively. Immunoblotting was used to measure PAR-1, PAR-2, MMP-2, ERK1/2 and Akt proteins. Apoptosis and cell cycle studies examined the combined effect of enoxaparin and doxorubicin. RESULTS: Enoxaparin inhibited A549 cell proliferation and migration. Following PAR-1 gene knock down, enoxaparin's effect on A549 cell proliferation was diminished compared to scrambled siRNA. Our experiments verified that enoxaparin-mediated down-regulation of MAPK and PI3K, reduced MMP-2 expression and inhibited A549 cell migration. Additionally, enoxaparin increased doxorubicin's efficacy by enhancing apoptosis, while no effect on cell-cycle progression was observed. CONCLUSION: Results suggest that the anticancer activity of enoxaparin in A549 cells was mediated by the interference of two major PAR-1 downstream signaling pathways, MAPK/ERK and PI3K/Akt, which in turn inhibit proliferation and migration. Therefore, enoxaparin may be promising as an adjunct to traditional chemotherapy for lung cancer and warrants further investigation.

UPR activation specifically modulates glutamate neurotransmission in the cerebellum of a mouse model of autism.

An increasing number of rare mutations linked to autism spectrum disorders have been reported in genes encoding for proteins involved in synapse formation and maintenance, such as the post-synaptic cell adhesion proteins neuroligins. Most of the autism-linked mutations in the neuroligin genes map on the extracellular protein domain. The autism-linked substitution R451C in Neuroligin3 (NLGN3) induces a local misfolding of the extracellular domain, causing defective trafficking and retention of the mutant protein in the endoplasmic reticulum (ER). The activation of the unfolded protein response (UPR), due to misfolded proteins accumulating in the ER, has been implicated in pathological and physiological conditions of the nervous system. It was previously shown that the over-expression of R451C NLGN3 in a cellular system leads to the activation of the UPR. Here, we have investigated whether this protective cellular response is detectable in the knock-in mouse model of autism endogenously expressing R451C NLGN3. Our data showed up-regulation of UPR markers uniquely in the cerebellum of the R451C mice compared to WT littermates, at both embryonic and adult stages, but not in other brain regions. Miniature excitatory currents in the Purkinje cells of the R451C mice showed higher frequency than in the WT, which was rescued inhibiting the PERK branch of UPR. Taken together, our data indicate that the R451C mutation in neuroligin3 elicits UPR in vivo, which appears to trigger alterations of synaptic function in the cerebellum of a mouse model expressing the R451C autism-linked mutation.

Targeted sensory enrichment interventions protect against behavioral and neuroendocrine consequences of early life stress.

Both basic and clinical research support the use of tactile stimulation to rescue several neurobiobehavioral consequences that follow early life stress. Here, using a translational rodent model of the neonatal intensive care unit (NICU), we tested the individual prophylactic potential of a variety of sensory interventions including tactile (brushing pups with a paint brush to mimic maternal licking), auditory (a simulated lactating rat dam heart beat), and olfactory (a series of aroma therapy scents) stimulation. The NICU model was developed to mimic not only the reduced parental contact that sick infants receive (by isolating rat pups from their litters), but also the nosocomial infections and medical manipulations associated with this experience (by utilizing a dual lipopolysaccharide injection schedule). Each of the neurobiobehavioral consequences observed were dissociable between isolation and inflammation, or required a combined presentation ('two hits') of the neonatal stressors. Sprague-Dawley rats exposed to these early life stressors presented with sex-specific disruptions in both separation-induced ultrasonic vocalization (USV) distress calls (males & females) and juvenile social play USVs (males only). All three sensory enhancement interventions were associated with the rescue of potentiated distress calls while olfactory stimulation was protective of social vocalizations. Female rats exposed to early life stress experienced precocious puberty and shifts in the hypothalamic GnRh axis; sensory enrichment counter-acted the advanced pubertal onset. Animals that underwent the NICU protocol also displayed maturational acceleration in terms of the loss of the rooting reflex in addition to hyperalgesia, a reduced preference for a novel conspecific, blunted basal plasma corticosterone and reduced hippocampal glucocorticoid receptor expression. These alterations closely simulated the clinical effects of early life adversity in terms of disruptions in the hypothalamic pituitary "stress" axis, social communication and engagement, tactile system processing, and accelerated maturation. Moreover, sensory enrichment attenuated many of these behavioral and neurophysiological alterations, and even slowed maturation. Overall, this supports the translatability of our novel rodent model and its potential utility in understanding how brain maturation and quality of early life experiences may interact to shape the integrity of stress and sensory system development. Future work must determine the appropriate modalities and parameters (e.g. patterning, timing) for effective sensory enrichment interventions.

Correction: Energy-dependent nucleolar localization of p53 in vitro requires two discrete regions within the p53 carboxyl terminus.

Following the publication of this article the authors noted that two images were duplicated in Figure 2B. The corrected figure 2B is below. The authors wish to apologize for any inconvenience caused.

Complex Environmental Rearing Enhances Social Salience and Affects Hippocampal Corticotropin Releasing Hormone Receptor Expression in a Sex-Specific Manner.

Methods for understanding the neurocircuitry of ethologically relevant behaviors have advanced substantially; however renovations to standard animal laboratory housing, in the form of enhanced enrichment, have lagged behind. This is despite evidence that environmental enrichment (EE) reduces stress, stereotypy, and promotes healthy species typical behaviors. While many scientists express interest for increased EE as a standard for animal caging systems, there are concerns that its effects on brain, behavior, and cognition are not well characterized. In the present study, male and female Sprague-Dawley rats were housed for six weeks in either EE, Colony Nesting (CN), or Standard Housing (SD) conditions. We show that adolescent exposure to environmental complexity changed the dynamics of social interactions, sensory processing, and underlying basal stress neurocircuitry, in a sex- and enrichment-type-dependent manner. Specifically, EE and CN increased prosocial engagement and the social saliency of male and female rats while the profile of hippocampal Crhr2 expression was affected only in EE males. Hippocampal Crh was associated with anxiety-like behavior in SD males - this did not extend to EE or CN groups, nor to females. Observations such as these are an important consideration for the validity of translational research investigating the neurocircuitry of stress resiliency, and for understanding the mechanisms of psychiatric disorders. Future work must focus on characterizing how individual environmental enhancements (e.g. novelty, social enrichment, physical activity) shape phenotypic differences, how they vary as a function of species, strain and sex, and (if warranted) how to meaningfully implement this knowledge into biomedical research designs.

Evaluation of three-dimensional SonoAVC ultrasound for antral follicle count in infertile women: its agreement with conventional two-dimensional ultrasound and serum levels of anti-Müllerian hormone.

BACKGROUND: Several studies have reported a correlation between antral follicle count by conventional 2D transvaginal sonography and serum anti-Müllerian hormone levels. However, few studies have investigated the effectiveness of 3D SonoAVC transvaginal ultrasound technology, particularly in infertile women. Therefore, this study aims to evaluate the usefulness of three-dimensional (3D) SonoAVC transvaginal ultrasound technology for antral follicle count and its correlation to conventional two-dimensional (2D) transvaginal ultrasound and serum levels of anti-Müllerian hormone in infertile women. METHODS: This cross-sectional study included 42 infertile women with age lower than 40 years that underwent treatment at a private fertility clinic between June and December 2015. Patient data included age, body mass index and cause of infertility. On cycle day 3 the following hormone levels were measured: serum levels of anti-Müllerian hormone, follicle-stimulating hormone, cancer antigen 125, prolactin, thyroid-stimulating hormone and oestradiol; the number of antral follicles was counted as well. The scanning were performed through 2D and 3D technology transvaginal ultrasound. RESULTS: Using a Bland-Altman test we demonstrated that both technologies are quite equivalent. However, antral follicle count is higher using 3D ultrasound technology compared to 2D technology (p < 0.001; Wilcoxon test), this finding is mainly remarkable in ovaries with more than 20 antral follicles. Moreover, the mean time required for manual 2D ultrasound and 3D SonoAVC measurements were 275 ± 109 and 103 ± 57 s, respectively (p < 0.001). Serum AMH concentration correlated to the total number of early antral follicles (correlation coefficients = 0.678 and 0.612; p < 0.001 by 2D ultrasound and 3D SonoAVC, respectively; Spearman's correlation test). CONCLUSIONS: Antral follicle count is better estimated using 3D ultrasound compared to 2D technology. A great advantage of 3D SonoAVC was less time required for an examination and the visual advantage when it need to count more than 20 follicles. TRIAL REGISTRATION: CAAE: 35141114.4.0000.5327 . Registered 10 June 2015.

Dome-like behaviour at Mt. Etna: The case of the 28 December 2014 South East Crater paroxysm.

On the 28 December 2014, a violent and short paroxysmal eruption occurred at the South East Crater (SEC) of Mount Etna that led to the formation of huge niches on the SW and NE flanks of the SEC edifice from which a volume of ~3 × 106 m3 of lava was erupted. Two basaltic lava flows discharged at a rate of ~370 m3/s, reaching a maximum distance of ~5 km. The seismicity during the event was scarce and the eruption was not preceded by any notable ground deformation, which instead was dramatic during and immediately after the event. The SO2 flux associated with the eruption was relatively low and even decreased few days before. Observations suggest that the paroxysm was not related to the ascent of volatile-rich fresh magma from a deep reservoir (dyke intrusion), but instead to a collapse of a portion of SEC, similar to what happens on exogenous andesitic domes. The sudden and fast discharge eventually triggered a depressurization in the shallow volcano plumbing system that drew up fresh magma from depth. Integration of data and observations has allowed to formulate a novel interpretation of mechanism leading volcanic activity at Mt. Etna and on basaltic volcanoes worldwide.

Slow wave activity as the default mode of the cerebral cortex.

The function of sleep remained one of largest enigmas of neuroscience for most of the 20th century. However in recent years different evidence has accumulated in support of a critical role of sleep on functions such as replay and memory consolidation. In particular slow wave sleep, and its underlying corticothalamocortical activity, slow oscillations, could be critical not only for memory but also for the maintenance of the brain's structural and func- tional connectivity. In this article we ask: why slow oscillations? To answer this question we put forward the idea that slow oscillations are the default activity of the cortical network based on both experimental and theoretical evidence. We go on to discuss why slow oscillations emerge from the cortical circuits and what are the dynamic advantages of this activity pattern, such as the resilience to perturbances and the facilitation of transitions between a disconnected (e.g. deep sleep) brain and a connected, awake brain.

Educational and career goals of pharmacy students upon graduation.

OBJECTIVE: To assess the doctor of pharmacy (PharmD) students' desire to obtain additional degrees after graduation. METHODS: During the spring 2011 semester, an anonymous 14-question survey instrument was administered to students across all 6 years of the PharmD program to evaluate their interest in obtaining an additional degree after graduation. Demographic data was also collected and analyzed from this convenience sample. RESULTS: Approximately 34% of the respondents (n=1,239) indicated a desire to seek an additional degree. Of the additional degrees offered in the survey instrument, more than one-third of the students expressed interest in the master of business administration (MBA). Also, 79% of those respondents were willing to take summer courses to achieve a dual or additional degree. CONCLUSION: Pharmacy students are interested in obtaining an additional degree(s) after graduation and are willing to complete summer courses to achieve their career goals.

Stop-event-related potentials from intracranial electrodes reveal a key role of premotor and motor cortices in stopping ongoing movements.

In humans, the ability to withhold manual motor responses seems to rely on a right-lateralized frontal-basal ganglia-thalamic network, including the pre-supplementary motor area and the inferior frontal gyrus (IFG). These areas should drive subthalamic nuclei to implement movement inhibition via the hyperdirect pathway. The output of this network is expected to influence those cortical areas underlying limb movement preparation and initiation, i.e., premotor (PMA) and primary motor (M1) cortices. Electroencephalographic (EEG) studies have shown an enhancement of the N200/P300 complex in the event-related potentials (ERPs) when a planned reaching movement is successfully stopped after the presentation of an infrequent stop-signal. PMA and M1 have been suggested as possible neural sources of this ERP complex but, due to the limited spatial resolution of scalp EEG, it is not yet clear which cortical areas contribute to its generation. To elucidate the role of motor cortices, we recorded epicortical ERPs from the lateral surface of the fronto-temporal lobes of five pharmacoresistant epileptic patients performing a reaching version of the countermanding task while undergoing presurgical monitoring. We consistently found a stereotyped ERP complex on a single-trial level when a movement was successfully cancelled. These ERPs were selectively expressed in M1, PMA, and Brodmann's area (BA) 9 and their onsets preceded the end of the stop process, suggesting a causal involvement in this executive function. Such ERPs also occurred in unsuccessful-stop (US) trials, that is, when subjects moved despite the occurrence of a stop-signal, mostly when they had long reaction times (RTs). These findings support the hypothesis that motor cortices are the final target of the inhibitory command elaborated by the frontal-basal ganglia-thalamic network.

A new paradigm in health care curriculums: the pharmaceutical and health care business degree.

The rapid growth of the healthcare industry, and the need to operate more efficiently in this environment, has generated an unmet need for competent business professionals with knowledge of the health care sciences. Additionally, student demand for a business curriculum that would satisfy the needs of the health care industry has provided the impetus for the development of the B.S. Pharmaceutical Health Care and Business program (PHCB). The purpose of this paper is to illustrate the evolution of this innovative curriculum within a school of Pharmacy, and to assess student satisfaction with the current PHCB program. To that end, a 19-item online questionnaire was developed and a group of 56 graduates (2007-2009) were surveyed which resulted in a response rate of 80%. The findings of this study indicated there was an overall high level of student satisfaction with this curriculum with an average of 86%, and that the PHCB program may offer potential to prepare graduates for the business and managerial aspects in the pharmaceutical, biotech, medical device, hospital and other allied health care segments.

Brain delivery of proteins by the intranasal route of administration: a comparison of cationic liposomes versus aqueous solution formulations.

The goal of this research was to evaluate the effectiveness of cationic liposomes for intranasal administration of proteins to the brain. Cationic liposomes were loaded with a model protein, ovalbumin (OVAL), and a 50 microg dose was administered intranasally to rats. In qualitative studies, liposomes were loaded with Alexa 488-OVAL and delivery was assessed by fluorescence microscopy. By 6 and 24 h after administration, Alexa 488-OVAL deposits were widely distributed throughout brain, with apparent cellular uptake in midbrain by 6 h after administration. In quantitative studies, liposomes were loaded with (111)In-OVAL, and distribution to brain and peripheral tissues was monitored by gamma counting at 1, 4, 6, and 24 h after administration. The highest brain concentrations were achieved at the shortest time point, 1 h, for both liposomal and aqueous OVAL. However, the liposomes yielded higher (111)In-OVAL concentrations in brain than (111)In-OVAL in PBS. Moreover, a 2 microg/microL form of liposomal OVAL yielded a higher percentage of dose in brain, and a lower percentage in stomach and intestines, than twice the volume of a 1 microg/microL preparation. Cationic liposomes may provide a novel, noninvasive strategy for delivery of neuroactive proteins to the brain for treatment of central nervous system disorders.

Temperature modulation of slow and fast cortical rhythms.

In the local cortical network, spontaneous emergent activity self-organizes in rhythmic patterns. These rhythms include a slow one (<1 Hz), consisting in alternation of up and down states, and also faster rhythms (10-80 Hz) generated during up states. Varying the temperature in the bath between 26 and 41 degrees C resulted in a strong modulation of the emergent network activity. Up states became shorter for warmer temperatures and longer with cooling, whereas down states were shortest at physiological (36-37 degrees C) temperature. The firing rate during up states was robustly modulated by temperature, increasing with higher temperatures. The sparse firing rate during down states hardly varied with temperature, thus resulting in a progressive merging of up and down states for temperatures around 30 degrees C. Below 30 degrees C and down to 26 degrees C the firing lost rhythmicity, becoming progressively continuous. The slope of the down-to-up transitions, which reflects the speed of recruitment of the local network, was progressively steeper for higher temperatures, whereas wave-propagation speed exhibited only a moderate increase. Fast rhythms were particularly sensitive to temperature. Broadband high-frequency fluctuations in the local field potential were maximal for recordings at 36-38 degrees C. Overall, we found that maintaining cortical slices at physiological temperature is critical for the generated activity to be analogous to that in vivo. We also demonstrate that changes in activity with temperature were not secondary to oxygenation changes. Temperature variation sets the in vitro cortical network at different functional regimes, allowing the exploration of network activity generation and control mechanisms.

Abdominal wall hernia repair: a comparison of Permacol and Surgisis grafts in a rat hernia model.

BACKGROUND: This study compared two porcine-derived grafts Permacol (Tissue Science Laboratory, Covington, GA, USA) and Surgisis (Cook Surgical, Bloomington, IN, USA) in terms of strength of incorporation (SOI), incorporation of host tissue, and adhesion formation using a rat model. METHODS: A prospective randomized study using 48 Sprague-Dawley rats. A standardized 1.5 x 5 cm fascial defect was created and repaired with either Permacol or Surgisis grafts. The rats were then sacrificed at 3, 14, 28, or 60 days. The specimens were examined for SOI, neovascularization, collagen deposition, collagen organization, and adhesion formation. RESULTS: Surgisis had significantly greater SOI than Permacol at 28 (0.115 vs. 0.0754 Mpa) and 60 days (0.131 vs. 0.635 Mpa). Surgisis had significantly more collagen deposition and neovascularization than Permacol at 60 days. The area of adhesions was not significantly different between Surgisis and Permacol. CONCLUSION: Surgisis is superior to Permacol in terms of SOI and tissue ingrowth at 60 days. Furthermore, Surgisis strengthened over time whereas Permacol decreased in strength.

Energy-dependent nucleolar localization of p53 in vitro requires two discrete regions within the p53 carboxyl terminus.

The p53 tumor suppressor is a nucleocytoplasmic shuttling protein that is found predominantly in the nucleus of cells. In addition to mutation, abnormal p53 cellular localization is one of the mechanisms that inactivate p53 function. To further understand features of p53 that contribute to the regulation of its trafficking within the cell, we analysed the subnuclear localization of wild-type and mutant p53 in human cells that were either permeabilized with detergent or treated with the proteasome inhibitor MG132. We, here, show that either endogenously expressed or exogenously added p53 protein localizes to the nucleolus in detergent-permeabilized cells in a concentration- and ATP hydrolysis-dependent manner. Two discrete regions within the carboxyl terminus of p53 are essential for nucleolar localization in permeabilized cells. Similarly, localization of p53 to the nucleolus after proteasome inhibition in unpermeabilized cells requires sequences within the carboxyl terminus of p53. Interestingly, genotoxic stress markedly decreases the association of p53 with the nucleolus, and phosphorylation of p53 at S392, a site that is modified by such stress, partially impairs its nucleolar localization. The possible significance of these findings is discussed.

Identification of an isomer impurity in piperaquine drug substance.

A significant contaminant of the antimalarial drug piperaquine (1,3-bis-[4-(7-chloroquinolyl-4)-piperazinyl-1]propane) has been identified using liquid chromatography-mass spectrometry (LC-MS) and 2D NMR spectroscopy (1H-1H COSY, 1H-13C HSQC, 1H-13C HMBC). The impurity was identified as the positional isomer 1-[(5-chloroquinolin-4)-piperazinyl]-3-[(7-chloroquinolin-4)-piperazinyl]propane. The impurity is formed because of contamination of batches of 4,7-dichloroquinoline (a precursor in the synthesis of piperaquine) with 4,5-dichloroquinoline. The amount of impurity (peak area impurity/peak area piperaquine using LC-UV at 347 nm) in old batches of piperaquine and in Artekin (the combination of dihydroartemisinin-piperaquine) ranged from 1.5 to 5%.