Large Pleural Effusion After Transjugular Intrahepatic Portosystemic Shunt, a Rare but Deadly Complication.

Cirrhosis affects more than 630,000 adults globally and can lead to development of ascites. Transjugular intrahepatic portosystemic shunt (TIPS) is an alternative option for refractory ascites in patients who are ineligible or are waiting for liver transplants. However, this procedure can have serious complications. We present a case that highlights the development of a complex pleural effusion complicated by hemorrhagic shock and disseminated intravascular coagulation after TIPS in a 54-year-old man. Our case is the first to report such a complication and aims to provide awareness.

Maternal Heart Failure.

Heart failure (HF) remains the most common major cardiovascular complication arising in pregnancy and the postpartum period. Mothers who develop HF have been shown to experience an increased risk of death as well as a variety of adverse cardiac and obstetric outcomes. Recent studies have demonstrated that the risk to neonates is significant, with increased risks in perinatal morbidity and mortality, low Apgar scores, and prolonged neonatal intensive care unit stays. Information on the causal factors of HF can be used to predict risk and understand timing of onset, mortality, and morbidity. A variety of modifiable, nonmodifiable, and obstetric risk factors as well as comorbidities are known to increase a patient's likelihood of developing HF, and there are additional elements that are known to portend a poorer prognosis beyond the HF diagnosis. Multidisciplinary cardio-obstetric teams are becoming more prominent, and their existence will both benefit patients through direct care and increased awareness and educate clinicians and trainees on this patient population. Detection, access to care, insurance barriers to extended postpartum follow-up, and timely patient counseling are all areas where care for these women can be improved. Further data on maternal and fetal outcomes are necessary, with the formation of State Maternal Perinatal Quality Collaboratives paving the way for such advances.

Stepwise Strategic Mitigation Planning in a Pediatric Oncology Center During the COVID-19 Pandemic.

Background: Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) first reached the United States in January 2020. Located in New York City (NYC), MSK Kids, at Memorial Sloan Kettering Cancer Center services, is one of the largest pediatric cancer centers in the U.S., caring for children, teenagers, and young adults with cancer, immune deficiencies, and blood disorders. Methods: Implementation for infection mitigation and ongoing care of patients included: (1) the creation of a strategic planning team of physicians, advanced practice providers, nurses, and administrators to develop guidance and workflows, (2) continuous reassessment of patients' needs for hospital services and visit frequency, (3) the use of telemedicine to replace in-person visits, (4) the use of satellite regional centers to manage patients living outside NYC, (5) pre-screening of patients prior to visits for risks and symptoms of coronavirus disease 2019 (COVID-19) infection, (6) day-of-service screening for risks or symptoms of COVID-19 infection, (7) surveillance testing of children and their caregivers, and (8) creation of cohort plans for the management of COVID-19 positive and uninfected patients within the same institution, in both the outpatient and inpatient settings. Results: We describe the timeline for planning mitigation during the first weeks of the pandemic, and detail in a stepwise fashion the rationale and implementation of COVID-19 containment efforts in the context of a large pediatric oncology program. Discussion: Our experience offers a model on which to base strategic planning efforts at other pediatric oncology centers, for continued preparedness to combat the threat posed by SARS-CoV-2 worldwide.

Author Correction: Distinct arsenic metabolites following seaweed consumption in humans.

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Distinct arsenic metabolites following seaweed consumption in humans.

Seaweeds contain arsenic primarily in the form of arsenosugars, which can be metabolized to a wide range of arsenic compounds. To characterize human exposure to arsenic from seaweed consumption, we determined concentrations of arsenic species in locally available seaweeds, and assessed urinary arsenic compounds in an experimental feeding study. A total of 11 volunteers consumed 10 g per day of three types of seaweeds (nori, kombu, and wakame) for three days each, while abstaining from rice and seafood following a three-day washout period. Urinary arsenosugars and their metabolites (including dimethyl arsenate (DMA), thio-dimethylarsinoylethanol (thio-DMAE), thio-dimethylarsinoylacetate (thio-DMAA), and thio-DMA) were measured in spot urine samples prior to seaweed consumption, and in 24-hour urine samples while consuming seaweed. Commercial products made from whole seaweed had substantial concentrations of arsenic (12-84 µg/g), dominated by arsenosugars. Intact arsenosugars along with DMA, thio-DMAA, thio-DMAE all increased in urine after ingesting each type of seaweed, and varied between seaweed types and between individuals. Only trace levels of the known toxic metabolite, thio-DMA, were observed, across individuals. Thio-DMAE and thio-DMAA are unique products of arsenosugar breakdown, thus assessment of these compounds may help to identify dietary intake of arsenic from seaweed from other exposure pathways.

epsilonPKC confers acute tolerance to cerebral ischemic reperfusion injury.

In response to mild ischemic stress, the brain elicits endogenous survival mechanisms to protect cells against a subsequent lethal ischemic stress, referred to as ischemic tolerance. The molecular signals that mediate this protection are thought to involve the expression and activation of multiple kinases, including protein kinase C (PKC). Here we demonstrate that epsilonPKC mediates cerebral ischemic tolerance in vivo. Systemic delivery of psiepsilonRACK, an epsilonPKC-selective peptide activator, confers neuroprotection against a subsequent cerebral ischemic event when delivered immediately prior to stroke. In addition, activation of epsilonPKC by psiepsilonRACK treatment decreases vascular tone in vivo, as demonstrated by a reduction in microvascular cerebral blood flow. Here we demonstrate the role of acute and transient epsilonPKC in early cerebral tolerance in vivo and suggest that extra-parenchymal mechanisms, such as vasoconstriction, may contribute to the conferred protection.

DeltaPKC mediates microcerebrovascular dysfunction in acute ischemia and in chronic hypertensive stress in vivo.

Maintaining cerebrovascular function is a priority for reducing damage following acute ischemic events such as stroke, and under chronic stress in diseases such as hypertension. Ischemic episodes lead to endothelial cell damage, deleterious inflammatory responses, and altered neuronal and astrocyte regulation of vascular function. These, in turn, can lead to impaired cerebral blood flow and compromised blood-brain barrier function, promoting microvascular collapse, edema, hemorrhagic transformation, and worsened neurological recovery. Multiple studies demonstrate that protein kinase C (PKC), a widely expressed serine/threonine kinase, is involved in mediating arterial tone and microvascular function. However, there is no clear understanding about the role of individual PKC isozymes. We show that intraperitoneal injection of deltaV1-1-TAT(47-57) (0.2 mg/kg in 1 mL), an isozyme-specific peptide inhibitor of deltaPKC, improved microvascular pathology, increased the number of patent microvessels by 92% compared to control-treated animals, and increased cerebral blood flow by 26% following acute focal ischemia induced by middle cerebral artery occlusion in normotensive rats. In addition, acute delivery of deltaV1-1-TAT(47-57) in hypertensive Dahl rats increased cerebral blood flow by 12%, and sustained delivery deltaV1-1-TAT(47-57) (5 uL/h, 1 mM), reduced infarct size by 25% following an acute stroke induced by MCA occlusion for 90 min. Together, these findings demonstrate that deltaPKC is an important therapeutic target for protection of microvascular structure and function under both acute and chronic conditions of cerebrovascular stress.

Protein kinase C delta (deltaPKC)-annexin V interaction: a required step in deltaPKC translocation and function.

Protein kinase C (PKC) plays a critical role in diseases such as cancer, stroke, and cardiac ischemia, and participates in a variety of signal transduction pathways such as apoptosis, cell proliferation, and tumor suppression. Though much is known about PKC downstream signaling events, the mechanisms of regulation of PKC activation and subsequent translocation have not been elucidated. Protein-protein interactions regulate and determine the specificity of many cellular signaling events. Such a specific protein-protein interaction is described here between deltaPKC and annexin V. We demonstrate, at physiologically relevant conditions, that a transient interaction between annexin V and deltaPKC occurs in cells after deltaPKC stimulation, but before deltaPKC translocates to the particulate fraction. Evidence of deltaPKC-annexin V binding is provided also by FRET and by in vitro binding studies. Dissociation of the deltaPKC-annexin V complex requires ATP and microtubule integrity. Furthermore, depletion of endogenous annexin V, but not annexin IV, with siRNA inhibits deltaPKC translocation following PKC stimulation. A rationally designed eight amino acid peptide, corresponding to the interaction site for deltaPKC on annexin V, inhibits deltaPKC translocation and deltaPKC-mediated function as evidenced by its protective effect in a model of myocardial infarction. Our data indicate that translocation of deltaPKC is not simply a diffusion-driven process, but is instead a multi-step event regulated by protein-protein interactions. We show that following cell activation, deltaPKC-annexin V binding is a transient and an essential step in the function of deltaPKC, thus identifying a new role for annexin V in PKC signaling and a new step in PKC activation.

The role of protein kinase C in cerebral ischemic and reperfusion injury.

BACKGROUND AND PURPOSE: Stroke is a leading cause of disability and death in the United States, yet limited therapeutic options exist. The need for novel neuroprotective agents has spurred efforts to understand the intracellular signaling pathways that mediate cellular response to stroke. Protein kinase C (PKC) plays a central role in mediating ischemic and reperfusion damage in multiple tissues, including the brain. However, because of conflicting reports, it remains unclear whether PKC is involved in cell survival signaling, or mediates detrimental processes. SUMMARY OF REVIEW: This review will examine the role of PKC activity in stroke. In particular, we will focus on more recent insights into the PKC isozyme-specific responses in neuronal preconditioning and in ischemia and reperfusion-induced stress. CONCLUSIONS: Examination of PKC isozyme activities during stroke demonstrates the clinical promise of PKC isozyme-specific modulators for the treatment of cerebral ischemia.

Protein kinase C delta mediates cerebral reperfusion injury in vivo.

Protein kinase C (PKC) has been implicated in mediating ischemic and reperfusion damage in multiple organs. However, conflicting reports exist on the role of individual PKC isozymes in cerebral ischemic injury. Using a peptide inhibitor selective for deltaPKC, deltaV1-1, we found that deltaPKC inhibition reduced cellular injury in a rat hippocampal slice model of cerebral ischemia [oxygen-glucose deprivation (OGD)] when present both during OGD and for the first 3 hr of reperfusion. We next demonstrated peptide delivery to the brain parenchyma after in vivo delivery by detecting biotin-conjugateddeltaV1-1 and by measuring inhibition of intracellular deltaPKC translocation, an indicator of deltaPKC activity. Delivery of deltaV1-1 decreased infarct size in an in vivo rat stroke model of transient middle cerebral artery occlusion. Importantly, deltaV1-1 had no effect when delivered immediately before ischemia. However, delivery at the onset, at 1 hr, or at 6 hr of reperfusion reduced injury by 68, 47, and 58%, respectively. Previous work has implicated deltaPKC in mediating apoptotic processes. We therefore determined whether deltaPKC inhibition altered apoptotic cell death or cell survival pathways in our models. We found that deltaV1-1 reduced numbers of terminal deoxynucleotidyl transferase-mediated biotinylated UTP nick end labeling-positive cells, indicating decreased apoptosis, increased levels of phospho-Akt, a kinase involved in cell survival pathways, and inhibited BAD (Bcl-2-associated death protein) protein translocation from the cell cytosol to the membrane, indicating inhibition of proapoptotic signaling. These data support a deleterious role for deltaPKC during reperfusion and suggest that deltaV1-1 delivery, even hours after commencement of reperfusion, may provide a therapeutic advantage after cerebral ischemia.

Cell-specific role for epsilon- and betaI-protein kinase C isozymes in protecting cortical neurons and astrocytes from ischemia-like injury.

Activation of epsilon protein kinase C (epsilonPKC) has been shown to protect cardiac myocytes against ischemia and reperfusion injury. However, the role of PKC in ischemic brain injury is less well defined. Western blot analysis of murine neurons and astrocytes in primary culture demonstrated epsilon- and betaIPKC expression in both cell types. Activation of epsilonPKC increased in neuronal cultures in response to the ischemia-like insult of oxygen-glucose deprivation (OGD). Isozyme-specific peptide activators or inhibitors of PKC were applied at various times before, during and after the OGD period. Neuron-astrocyte mixed cultures pretreated with a selective epsilonPKC activator peptide showed a significant reduction in neuronal injury after OGD and reperfusion, compared to cultures pretreated with control peptide. The epsilonPKC activator peptide counteracted the increased damage induced by pretreatment with the epsilonPKC-selective inhibitor peptide in relatively pure neuronal cultures subjected to OGD. Neither epsilonPKC activator nor inhibitor peptides affected injury of neurons when applied after OGD onset. In contrast, the betaIPKC-selective inhibitor peptide increased injury in astrocyte cultures exposed to OGD at all application times tested. Our data demonstrate protection of neurons by selective activation of epsilonPKC but enhanced astrocyte cell death with selective inhibition of betaIPKC. Thus PKC isozymes exhibit cell type-specific effects on ischemia-like injury.