Roberto Ruiz-Cordero

Decreased Astrocytic Thrombospondin-1 Secretion After Chronic Ammonia Treatment Reduces the Level of Synaptic Proteins: In Vitro and In Vivo Studies

Chronic hepatic encephalopathy (CHE) is a major complication in patients with severe liver disease. Elevated blood and brain ammonia levels have been implicated in its pathogenesis, and astrocytes are the principal neural cells involved in this disorder. Since defective synthesis and release of astrocytic factors have been shown to impair synaptic integrity in other neurological conditions, we examined whether thrombospondin‐1 (TSP‐1), an astrocytic factor involved in the maintenance of synaptic integrity, is also altered in CHE. Cultured astrocytes were exposed to ammonia (NH4Cl, 0.5–2.5 mM) for 1–10 days, and TSP‐1 content was measured in cell extracts and culture media. Astrocytes exposed to ammonia exhibited a reduction in intra‐ and extracellular TSP‐1 levels. Exposure of cultured neurons to conditioned media from ammonia‐treated astrocytes showed a decrease in synaptophysin, PSD95, and synaptotagmin levels. Conditioned media from TSP‐1 over‐expressing astrocytes that were treated with ammonia, when added to cultured neurons, reversed the decline in synaptic proteins. Recombinant TSP‐1 similarly reversed the decrease in synaptic proteins. Metformin, an agent known to increase TSP‐1 synthesis in other cell types, also reversed the ammonia‐induced TSP‐1 reduction. Likewise, we found a significant decline in TSP‐1 level in cortical astrocytes, as well as a reduction in synaptophysin content in vivo in a rat model of CHE. These findings suggest that TSP‐1 may represent an important therapeutic target for CHE.

Increased toll-like receptor 4 in cerebral endothelial cells contributes to the astrocyte swelling and brain edema in acute hepatic encephalopathy.

Astrocyte swelling and the subsequent increase in intracranial pressure and brain herniation are major clinical consequences in patients with acute hepatic encephalopathy. We recently reported that conditioned media from brain endothelial cells (ECs) exposed to ammonia, a mixture of cytokines (CKs) or lipopolysaccharide (LPS), when added to astrocytes caused cell swelling. In this study, we investigated the possibility that ammonia and inflammatory agents activate the toll‐like receptor 4 (TLR4) in ECs, resulting in the release of factors that ultimately cause astrocyte swelling. We found a significant increase in TLR4 protein expression when ECs were exposed to ammonia, CKs or LPS alone, while exposure of ECs to a combination of these agents potentiate such effects. In addition, astrocytes exposed to conditioned media from TLR4‐silenced ECs that were treated with ammonia, CKs or LPS, resulted in a significant reduction in astrocyte swelling. TLR4 protein up‐regulation was also detected in rat brain ECs after treatment with the liver toxin thioacetamide, and that thioacetamide‐treated TLR4 knock‐out mice exhibited a reduction in brain edema. These studies strongly suggest that ECs significantly contribute to the astrocyte swelling/brain edema in acute hepatic encephalopathy, likely as a consequence of increased TLR4 protein expression by blood‐borne noxious agents.

Activation of NF-κB Mediates Astrocyte Swelling and Brain Edema in Traumatic Brain Injury

Brain edema and associated increased intracranial pressure are major consequences of traumatic brain injury (TBI). While astrocyte swelling (cytotoxic edema) represents a major component of the brain edema in the early phase of TBI, its mechanisms are unclear. One factor known to be activated by trauma is nuclear factor-κB (NF-κB). Because this factor has been implicated in the mechanism of cell swelling/brain edema in other neurological conditions, we examined whether NF-κB might also be involved in the mediation of post-traumatic astrocyte swelling/brain edema. Here we show an increase in NF-κB activation in cultured astrocytes at 1 and 3 h after trauma (fluid percussion injury, FPI), and that BAY 11-7082, an inhibitor of NF-κB, significantly blocked the trauma-induced astrocyte swelling. Increased activities of nicotinamide adenine dinucleotide phosphate-oxidase and the Na(+), K(+), 2Cl(-) cotransporter were also observed in cultured astrocytes after trauma, and BAY 11-7082 reduced these effects. We also examined the role of NF-κB in the mechanism of cell swelling by using astrocyte cultures derived from transgenic (Tg) mice with a functional inactivation of astrocytic NF-κB. Exposure of cultured astrocytes from wild-type mice to in vitro trauma (3 h) caused a significant increase in cell swelling. By contrast, traumatized astrocyte cultures derived from NF-κB Tg mice showed no swelling. We also found increased astrocytic NF-κB activation and brain water content in rats after FPI, while BAY 11-7082 significantly reduced such effects. Our findings strongly suggest that activation of astrocytic NF-κB represents a key element in the process by which cytotoxic brain edema occurs after TBI.

Impact of 2004 ISUP/WHO classification on bladder cancer grading

PurposeTo determine whether implementation of the 2004 WHO/ISUP bladder cancer (BCa) grading system caused a grade migration, i.e., more tumors being graded as high grade (HG).MethodsData on 1040 BCa cases from 668 patients treated at our institution between 2000 and 2013 and reviewed by six pathologists were evaluated: low grade (LG): 249; HG: 791; Ta: 389; T1: 214; CIS: 95; ≥T2: 342. Differences in LG or HG cases (expressed as %BCa cases/year) were analyzed by Mann–Whitney test. Correlation between the year of diagnosis and clinical/pathological parameters was evaluated by logistic regression analyses.ResultsDuring the study period, BCa cases diagnosed as LG significantly decreased with a corresponding increase in HG cases. Nonlinear regression analysis indicated that ~2008 was the crossover point for grade migration; %LG: 31.8xa0±xa04.8 (2000–2007); 14.1xa0±xa07.0 (2008–2013); %HG: 68.2xa0±xa04.8 (2000–2007); 85.9xa0±xa06.9 (2008–2013), Pxa0=xa00.004. The grade migration was confined to Ta cases with %LG Ta cases diagnosed decreasing by 3.6-fold from 2000–2007 to 2008–2013 (Pxa0=xa00.004). Univariate and multivariate analyses confirmed the grade migration following the adoption of the 2004 system (Pxa0<xa00.0001). Kaplan–Meier curves showed no significant differences between the two time intervals in terms of disease progression (Pxa0>xa00.05).ConclusionsImplementation of the 2004 WHO/ISUP system caused a significant increase in pathologists grading Ta cases as HG; however, this increase did not seem to correlate with disease progression. Since LG and HG Ta tumors are treated differently, grade migration may impact the clinical management of BCa patients.

Adrenal Oncocytic Neoplasm with Paradoxical Loss of Important Mitochondrial Steroidogenic Protein: The 18 kDA Translocator Protein

The adrenal glands produce a variety of hormones that play a key role in the regulation of blood pressure, electrolyte homeostasis, metabolism, immune system suppression, and the bodys physiologic response to stress. Adrenal neoplasms can be asymptomatic or can overproduce certain hormones that lead to different clinical manifestations. Oncocytic adrenal neoplasms are infrequent tumors that arise from cells in the adrenal cortex and display a characteristic increase in the number of cytoplasmic mitochondria. Since the rate-limiting step in steroidogenesis includes the transport of cholesterol across the mitochondrial membranes, in part carried out by the 18-kDa translocator protein (TSPO), we assessed the expression of TSPO in a case of adrenal oncocytic neoplasm using residual adrenal gland of the patient as internal control. We observed a significant loss of TSPO immunofluorescence expression in the adrenal oncocytic tumor cells when compared to adjacent normal adrenal tissue. We further confirmed this finding by employing Western blot analysis to semiquantify TSPO expression in tumor and normal adrenal cells. Our findings could suggest a potential role of TSPO in the tumorigenesis of this case of adrenocortical oncocytic neoplasm.

Cost-Containment Protocols for Prostate Core Needle Biopsies: Hypothetical Scenarios to Reduce Procedural Costs

Background In recent years, anatomic pathology laboratories have been struck by new revenue policies secondary to the Affordable Care Act. In particular, modifications to compensation for processing prostatic core needle biopsies (PCNBs) have led to important reimbursement cuts. Herein, we explore a hypothetical reduction in the costs for the processing of PCNBs using three simple, hypothetical methods while maintaining high-standard patient care. Materials and methods We determined the number of blocks and slides used per case on all PCNBs performed at our institution from August 2013 to September 2014 and calculated the total procedural cost for each case and for the total number of cases processed during the study period based on a published estimated procedural cost. We then estimated the procedural cost of three different proposed hypothetical scenarios that consisted in reducing the number of blocks used per case. A Student t test was used to assess the difference between real and hypothetical costs. Results A total of 4,406 paraffin blocks were used to process 363 PCNBs with a total annual procedural cost of

Twin Reversed Arterial Perfusion Sequence (TRAPS): An Illustrative Series of 13 Cases

26,303. By implementing any of the hypothetical scenarios, the annual procedural cost was significantly reduced; the reduction could potentially be as low as

Multidisciplinary Teaching Atlas of the Pancreas

8,978 (P < 0.0001). Conclusions This study illustrates three hypothetical alternatives that could dramatically reduce the procedural costs of PCNBs while maintaining high-quality care. Implementation of these scenarios at a global scale could potentially have an impact on health-care cost in the USA of several millions of dollars per year.

Pancreatic Ductal Adenocarcinoma (PDAC)

ABSTRACT Twin reversed-arterial-perfusion sequence (TRAPS) is a rare and severe complication of monochorionic twin pregnancies. It usually occurs in the setting of monochorionic placentation, when the heart of a normal appearing twin serves as the pump for one or more dysmorphic twins whose head, thoracic organs, and upper extremities do not fully develop or do not develop at all and thus lack cardiac activity. Anomalous vascular placental architecture causes a shift in arterial flow towards the acardiac twin(s). The exact physiopathologic mechanisms that lead to this devastating phenomenon are not well known. We reviewed the maternal history and the surgical pathology reports of the fetuses and placentas of 13 different cases of TRAPS that were collected in a 23-year study period at a single institution. Herein we summarize the characteristic findings and illustrate specific mechanical feto-placental circulation issues that appear to be instrumental in the development of TRAPS.