Differential encoding in prefrontal cortex projection neuron classes across cognitive tasks.

Single-cell transcriptomics has been widely applied to classify neurons in the mammalian brain, while systems neuroscience has historically analyzed the encoding properties of cortical neurons without considering cell types. Here we examine how specific transcriptomic types of mouse prefrontal cortex (PFC) projection neurons relate to axonal projections and encoding properties across multiple cognitive tasks. We found that most types projected to multiple targets, and most targets received projections from multiple types, except PFC→PAG (periaqueductal gray). By comparing Ca2+ activity of the molecularly homogeneous PFC→PAG type against two heterogeneous classes in several two-alternative choice tasks in freely moving mice, we found that all task-related signals assayed were qualitatively present in all examined classes. However, PAG-projecting neurons most potently encoded choice in cued tasks, whereas contralateral PFC-projecting neurons most potently encoded reward context in an uncued task. Thus, task signals are organized redundantly, but with clear quantitative biases across cells of specific molecular-anatomical characteristics.

Shared Cortex-Cerebellum Dynamics in the Execution and Learning of a Motor Task.

Throughout mammalian neocortex, layer 5 pyramidal (L5) cells project via the pons to a vast number of cerebellar granule cells (GrCs), forming a fundamental pathway. Yet, it is unknown how neuronal dynamics are transformed through the L5→GrC pathway. Here, by directly comparing premotor L5 and GrC activity during a forelimb movement task using dual-site two-photon Ca2+ imaging, we found that in expert mice, L5 and GrC dynamics were highly similar. L5 cells and GrCs shared a common set of task-encoding activity patterns, possessed similar diversity of responses, and exhibited high correlations comparable to local correlations among L5 cells. Chronic imaging revealed that these dynamics co-emerged in cortex and cerebellum over learning: as behavioral performance improved, initially dissimilar L5 cells and GrCs converged onto a shared, low-dimensional, task-encoding set of neural activity patterns. Thus, a key function of cortico-cerebellar communication is the propagation of shared dynamics that emerge during learning.

Cortical reactivations predict future sensory responses.

Many theories of offline memory consolidation posit that the pattern of neurons activated during a salient sensory experience will be faithfully reactivated, thereby stabilizing the pattern1,2. However, sensory-evoked patterns are not stable but, instead, drift across repeated experiences3-6. Here, to investigate the relationship between reactivations and the drift of sensory representations, we imaged the calcium activity of thousands of excitatory neurons in the mouse lateral visual cortex. During the minute after a visual stimulus, we observed transient, stimulus-specific reactivations, often coupled with hippocampal sharp-wave ripples. Stimulus-specific reactivations were abolished by local cortical silencing during the preceding stimulus. Reactivations early in a session systematically differed from the pattern evoked by the previous stimulus-they were more similar to future stimulus response patterns, thereby predicting both within-day and across-day representational drift. In particular, neurons that participated proportionally more or less in early stimulus reactivations than in stimulus response patterns gradually increased or decreased their future stimulus responses, respectively. Indeed, we could accurately predict future changes in stimulus responses and the separation of responses to distinct stimuli using only the rate and content of reactivations. Thus, reactivations may contribute to a gradual drift and separation in sensory cortical response patterns, thereby enhancing sensory discrimination7.

A nanocomposite prepared from FeOOH and N-doped carbon nanosheets as a peroxidase mimic, and its application to enzymatic sensing of glucose in human urine.

A method is described for the synthesis of a nanocomposite containing FeOOH and N-doped carbon nanosheets. The nanocomposite was synthesized by a hydrothermal method using a Fe3O4/chitosan nanocomposite as the precursor. The nanocomposite displays peroxidase-like activity and catalyzes the oxidation of 3,3',5,5'-tetramethylbenzidine (TMB) by H2O2. This results in the formation of a blue colored product with an absorption maximum at 652 nm in the UV-vis spectra. Based on these findings, colorimetric assays were worked out for both hydrogen peroxide and glucose. The H2O2 assay works in the 5 to 19 µM concentration range, and the limit of detection is 5 nM. The glucose assay works in the 8 µM to 0.8 mM concentration range and has a 0.2 µM detection limit. The method was successfully applied to the determination of glucose in human urine. Graphical abstract Schematic of the hydrothermal synthesis of a FeOOH/N-doped carbon nanocomposite. It was used to replace peroxidase enzyme for the catalytic oxidation of 3,3',5,5'-tetramethylbenzidine (TMB) in a visual colorimetric test for glucose in human urine.

Platelet aggregometry cannot identify uremic platelet dysfunction in heart failure patients prior to cardiac surgery.

BACKGROUND: Patients with heart failure often have concomitant renal disease which can result in uremic platelet dysfunction. Determining whether uremia has affected platelets by platelet aggregometry can be challenging in these patients since they are often on antiplatelet medications. This study was undertaken to determine if platelet aggregation studies could identify heart failure patients at risk for uremic bleeding prior to cardiac surgery. METHODS: Platelet aggregation studies from three groups were studied and compared: 17 heart failure patients with mild to moderate renal impairment, 17 heart failure patients without renal abnormalities and 17 healthy volunteers. RESULTS: Platelet aggregation was severely impaired in both heart failure groups with and without renal abnormalities compared to healthy controls, and there were no significant differences in platelet aggregation in response to any of the agonists. There was a pan-decrease in platelet aggregation to all agonists in all heart failure patients. CONCLUSION: Platelet aggregometry does not appear to be useful in measuring platelet dysfunction in heart failure patients with mild to moderate renal impairment.

Emergency department triage of low acuity patients to a Federally Qualified Health Center.

Many emergency departments (ED) are experiencing ever increasing volumes as they serve as a safety net for patients without established access to primary care. Impending physician shortages, our aging population, and recent changes in national healthcare policy are expected to further exacerbate this situation and worsen ED overcrowding. These conditions could result in a dilution of ED resources and significantly impact the ability of emergency personnel to provide quality care for patients with serious illnesses. Previous studies have demonstrated that low acuity patients without emergencies can be safely and legally identified in triage and can be sent away from the ED for further outpatient treatment and evaluation. However, without a specific designated clinic follow up, these patients often fail to get the appropriate care required. In this study, we couple the ED medical screening exam process with a timely medical referral system to a local Federally Qualified Healthcare Clinic (FQHC). These referred patients were monitored for subsequent success in satisfaction with their primary care needs and their rate of recidivism to the ED. Most of the non-emergent patients who were judged to be appropriate to refer to the FQHC were satisfied with their medical screening process (89%) and most elected to attend the same day clinic appointment at the FQHC (85%). Only 17% of these patients who were referred out of our ED returned to be seen in our ED within the three-month interval. We concluded that referring low acuity patients out of the emergency department to a primary care clinic setting provided an opportunity for these patients to establish a medical home for future access to non-emergent health care.

Primary Effusion Lymphoma: A Clinicopathological Study of 70 Cases.

Primary effusion lymphoma (PEL) is a rare type of large B-cell lymphoma associated with human herpesvirus 8 (HHV8) infection. Patients with PEL usually present with an effusion, but occasionally with an extracavitary mass. In this study, we reported a cohort of 70 patients with PEL: 67 men and 3 women with a median age of 46 years (range 26-91). Of these, 56 (80%) patients had human immunodeficiency virus (HIV) infection, eight were HIV-negative, and six had unknown HIV status. Nineteen (27%) patients had Kaposi sarcoma. Thirty-five (50%) patients presented with effusion only, 27 (39%) had an extracavitary mass or masses only, and eight (11%) had both effusion and extracavitary disease. The lymphoma cells showed plasmablastic, immunoblastic, or anaplastic morphology. All 70 (100%) cases were positive for HHV8. Compared with effusion-only PEL, patients with extracavitary-only PEL were younger (median age, 42 vs. 52 years, p = 0.001), more likely to be HIV-positive (88.9% vs. 68.6%, p = 0.06) and EBV-positive (76.9% vs. 51.9%, p = 0.06), and less often positive for CD45 (69.2% vs. 96.2%, p = 0.01), EMA (26.7% vs. 100%, p = 0.0005), and CD30 (60% vs. 81.5%, p = 0.09). Of 52 (50%) patients with clinical follow-up, 26 died after a median follow-up time of 40.0 months (range 0-96), and the median overall survival was 42.5 months. The median OS for patients with effusion-only and with extracavitary-only PEL were 30.0 and 37.9 months, respectively (p = 0.34), and patients with extracavitary-only PEL had a lower mortality rate at the time of last follow-up (35% vs. 61.5%, p = 0.07). The median OS for HIV-positive and HIV-negative patients were 42.5 and 6.8 months, respectively (p = 0.57), and they had a similar mortality rate of 50% at last follow-up. In conclusion, patients presenting with effusion-only versus extracavitary-only disease are associated with different clinicopathologic features. PEL is an aggressive lymphoma with a poor prognosis, regardless of extracavitary presentation or HIV status.

Educational Case: Mantle Cell Lymphoma.

The following fictional case is intended as a learning tool within the Pathology Competencies for Medical Education (PCME), a set of national standards for teaching pathology. These are divided into three basic competencies: Disease Mechanisms and Processes, Organ System Pathology, and Diagnostic Medicine and Therapeutic Pathology. For additional information, and a full list of learning objectives for all three competencies, see http://journals.sagepub.com/doi/10.1177/2374289517715040.1.

Educational Case: Systemic Mastocytosis with an Associated Hematological Neoplasm.

The following fictional case is intended as a learning tool within the Pathology Competencies for Medical Education (PCME), a set of national standards for teaching pathology. These are divided into three basic competencies: Disease Mechanisms and Processes, Organ System Pathology, and Diagnostic Medicine and Therapeutic Pathology. For additional information, and a full list of learning objectives for all three competencies, see http://journals.sagepub.com/doi/10.1177/2374289517715040.1.

Anaplastic large cell lymphoma in leukemic phase: extraordinarily high white blood cell count.

Anaplastic large cell lymphoma (ALCL) is a distinct type of T/null-cell non-Hodgkin lymphoma that commonly involves nodal and extranodal sites. The World Health Organization of lymphoid neoplasms recognizes two types: anaplastic lymphoma kinase (ALK) positive or ALK negative, the former as a result of abnormalities involving the ALK gene at chromosome 2p23. Patients with ALCL rarely develop a leukemic phase of disease, either at the time of initial presentation or during the clinical course. Described herein is a patient with ALK+ ALCL, small cell variant, associated with the t(2;5)(p23;q35), who initially presented with leukemic involvement and an extraordinarily high leukocyte count of 529 x 10(9)/L, which subsequently peaked at 587 x 10(9)/L. Despite chemotherapy the patient died 2(1/2) months after diagnosis. In the literature review 20 well-documented cases are identified of ALCL in leukemic phase reported previously, with a WBC ranging from 15 to 151 x 10(9)/L. Leukemic phase of ALCL occurs almost exclusively in patients with ALK+ ALCL, most often associated with the small cell variant and the t(2;5)(p23;q35), similar to the present case. Patients with leukemic phase ALK+ ALCL appear to have a poorer prognosis than most patients with ALK+ ALCL.

Howell-Jolly Body-Like Inclusions in Neutrophils of Patients With Myelodysplastic Syndrome: A Novel Correlation.

CONTEXT.­: Howell-Jolly body-like inclusions have been previously associated with patients who are human immunodeficiency virus (HIV) infected, taking antiviral medications, and immunosuppressed. These inclusions appear in neutrophils and resemble Howell-Jolly bodies of normoblasts in abnormal erythropoiesis. In granulocytes, they are thought to represent detached nuclear fragments produced from dysplastic granulopoiesis. To the best of our knowledge, no association of Howell-Jolly body-like inclusions and myelodysplastic syndrome (MDS) has been reported previously. OBJECTIVE.­: To establish an unprecedented correlation of Howell-Jolly body-like inclusions in patients with MDS. DESIGN.­: Eleven bone marrow cases from patients diagnosed with MDS and 20 bone marrow cases with no significant pathologic alterations were retrospectively reviewed. Detailed medical record review was performed to ensure none of the patients had a history of HIV, or was taking immunosuppressants and/or antiviral medications. RESULTS.­: Eight of 11 cases (72%) from the study group show detached intracytoplasmic inclusions in a minority (<5%) of mature neutrophils consistent with Howell-Jolly body-like inclusions. No Howell-Jolly body-like inclusions were identified in the control group. Notably, none of the selected patients had a history of HIV or was taking immunosuppressants and antiviral medications. CONCLUSIONS.­: In review of the literature, Howell-Jolly body-like inclusions seem to correlate with immunosuppression and antiviral therapies with nucleoside analogs. We propose that the formation of Howell-Jolly body-like inclusions is the consequence of dysplasia, and hence its correlation not only with the abovementioned conditions, but also with MDS. The inclusions are, however, seen in only a minority of white cells (<5%), which is probably why they were not brought to practicing pathologists' awareness in the past. This study aims to raise awareness and correlate the presence of Howell-Jolly body-like inclusions in MDS.

M2 Macrophages in Crystal Storing Histiocytosis Associated with Plasma Cell Myeloma.

Crystal Storing Histiocytosis (CSH) is a rare entity occurring in association with underlying lymphoproliferative disorders and plasma cell neoplasms. It denotes accumulation of immunoglobulin crystals in the histiocyte cytoplasm. In this study, we report a patient with plasma cell myeloma who presented with bilateral comminuted femur fractures. Histological examination of fracture tissue revealed hypercellular (~100%) marrow with extensive involvement by sheets of histiocytes with abundant eosinophilic cytoplasm admixed with scattered plasma cells. Intracytoplasmic diamond and rhomboid crystals within histiocytes were demonstrated by electron microscopy. Immunohistochemistry highlighted monotypic plasma cells with kappa restriction, representing 20-30% of marrow cellularity; however, non-polarizable cytoplasmic striations in histiocytes were negative for light chain expression. A diagnosis of crystal-storing histiocytosis associated with plasma cell myeloma was rendered. Further evaluation of these macrophages is positive for CD163 and COX2 and shows pSTAT3 with variable nuclear staining in some histiocytes. This case demonstrates that numerous M2 macrophages are present as crystal storing histiocytosis; and this knowledge might convey prognostic and therapeutic significance for the patients with crystal storing histiocytosis.

PIFA PLUSS P4 Assay for Screening of Heparin-Induced Thrombocytopenia.

BACKGROUND: The PIFA PLUSS PF4 Rapid Assay (PIFA) is a rapid screening test used for the diagnosis of heparin-induced thrombocytopenia (HIT). OBJECTIVE: To determine the usefulness of this assay as a screening method in our institution. METHODS: A total of 159 specimens from patients with suspected HIT were included in our study. We simultaneously performed PIFA assay and confirmatory polyspecific enzyme-linked immunosorbent assay (ELISA). We subjected most of the specimens with false-negative results to serotonin release assay (SRA). RESULTS: The initial sensitivity and specificity of the PIFA assay were calculated as 27.3% and 71.5%, respectively. A total of 12 of 16 false-negative results were further tested using the SRA method. The revised sensitivity and specificity were 50.0% and 73.5%, respectively. CONCLUSIONS: Despite its appealing feature of yielding rapid results, the PIFA assay is inadequate as a sole screening test for HIT because of its high probability of missing many true cases of HIT.

Effects of the Use of a Mallet during Bone Marrow Biopsy Collection on Specimen Quality: A Quality Improvement Project.

CONTEXT: Avoiding procedure-related morphologic distortion such as fragmentation and crush artifact is critical in bone marrow diagnosis. Use of a hammer or mallet, although infrequent, is a known technique of advancing the biopsy needle during specimen collection. OBJECTIVES: We performed a double-blinded, retrospective review of bone marrow biopsies collected by the Interventional Radiology department at our institution in order to assess specimen quality by using this technique. DESIGN: We reviewed 93 bone marrow biopsy specimens collected at our hospitals, between January 2015 and June 2015. Routine bone marrow core biopsy slides were reviewed. The presence of crush artifact, specimen fragmentation, and aspiration artifact, as well as the presence of osteopenia and an overall grade of specimen adequacy, was recorded for each specimen. RESULTS: A sterile mallet was used during the bone marrow biopsy procedure in 29 cases. Use of a mallet was significantly associated with the presence of suboptimal or inadequate specimen quality of bone marrow core biopsy (p<0.005) and was independently associated with severe specimen fragmentation (2+) (p<0.0001). There was no statistically significant association between length of the core and use of a mallet. CONCLUSIONS: Use of a mallet during bone marrow core biopsy collection is significantly associated with morphologic distortion in the form of severe specimen fragmentation and negatively affects specimen adequacy. There is no difference in length of core biopsy as previously thought by using a mallet to advance the needle during the procedure. We recommend that the use of this technique should be avoided during specimen collection.

Myeloid Sarcoma in a Patient with Myelodysplastic Syndrome Associated with del(5q-): Case Report and Literature Review.

OBJECTIVE: Myeloid sarcoma (MS) is defined in the World Health Organization classification as a tumor mass consisting of myeloblasts with or without maturation and involving any anatomic site other than the bone marrow. We present a case of MS developing in a patient with 5q- myelodysplastic syndrome (MDS) and review the relevant literature. METHODS: A 77-year-old woman with recent diagnosis of MDS associated with del(5q) presented with symptoms and signs attributable to a mass involving the T8 vertebra. Biopsy of the spinal mass was performed and the specimen was analyzed using routine hematoxylin-eosin stain, immunohistochemical methods, and fluorescence in situ hybridization (FISH). RESULTS: Microscopic examination revealed an infiltrate of intermediate-large cells with basophilic cytoplasm and nuclei containing occasional prominent nucleoli. Immunohistochemical analysis showed that the neoplastic cells were positive for CD4, CD43, CD45, CD68, and CD117, and negative for B- and T-cell antigens supporting the diagnosis of MS. Fluorescence in situ hybridization of the spinal mass showed del(5q) in the neoplastic cells. CONCLUSION: Although the 5q- syndrome is a clinically indolent form of MDS, a small subset of patients may develop MS as illustrated in this patient. The relevant literature is also reviewed.

Morphoproteomics Identifies SIRT1 and EZH2 Pathways as Commonalities in B-cell Acute Lymphoblastic Leukemia: Pathogenetic Implications and Opportunities for Therapeutic Intervention.

B-cell acute lymphoblastic leukemia (ALL) represents a malignant process in which bone marrow-derived lymphoblasts retain their undifferentiated state. Genetic testing has revealed either no identifiable cytogenetic and genomic abnormalities in such patients or a wide range of aberrations that may or may not contribute to the block in differentiation and the associated proliferation of the malignant lymphoblasts in cases of B-cell ALL. In this study, we applied morphoproteomics to a representative spectrum of cases of newly diagnosed B-cell ALL in order to identify pathways that are known to be associated with the maintenance of the undifferentiated state while promoting proliferation. Our results showed nuclear expression in a majority of the lymphoblasts from bone marrow clot preparations of each of the study cases for both silent mating type information regulation 2 homolog 1 (SIRT1), an NAD+ histone deacetylase and enhancer of Zeste homolog 2 (EZH2), a histone methyltransferase. These represent pathogenetic pathways capable of blocking differentiation and promoting proliferation of the B-cell ALL lymphoblasts. Data mining of the National Library of Medicine's MEDLINE Database and Ingenuity Pathway analysis revealed agents of relatively low toxicity-melatonin, metformin, curcumin and sulforaphane-that are capable of inhibiting directly or pharmacogenomically one or both of the SIRT1 and EZH2 pathways and should, in a combinatorial fashion, remove the block in differentiation and decrease the proliferation of the B-cell ALL lymphoblasts.

Post-transplant Lymphoproliferative Disorder Presented in a Form of Primary Effusion Lymphoma with t (8; 14).

Post-transplant lymphoproliferative disorders (PTLD) are emergent complications of organ transplantation occurring in 2% to 10% of transplanted patients. Epstein-Barr virus (EBV) infections are considered the most important factors for the development of these heterogeneous disorders. Primary effusion lymphoma (PEL) is a lymphoproliferative disorder predominantly described in patients with advanced AIDS and it is almost universally associated with human herpesvirus 8 (HHV8). In rare case, PEL also occurs in HHV8-negative patient, in the setting of hepatitis B and C virus infection. However, all these cases showed pan B-cell markers to be positive. Here, we report a case of PTLD presented as HHV8-negative and HIV-negative primary effusion lymphoma lacking near all lymphoid markers except PAX5 on immunohistochemistry, which created a diagnostic challenge. The diagnosis requires multiple approaches including molecular and genetic tests.

Inequity in National Institutes of Health Predoctoral Fellowships, 2001-2020.

This cross-sectional study examines trends in number of awards and funding of general and diversity F31 predoctoral fellowships from 2001 to 2020.

Short-Term Experience with Off-Pump Versus On-Pump Implantation of the HeartWare Left Ventricular Assist Device.

Implantation of left ventricular assist devices while avoiding cardiopulmonary bypass (CPB) may decrease bleeding and improve postoperative recovery. To understand the effectiveness of this approach, we reviewed the charts of 26 patients who underwent HeartWare left ventricular assist device (HVAD) implantation without use of CPB (off-CPB group) and 22 patients who had HVAD implanted with CPB (CPB group) with an emphasis on the 30 day postoperative period. Preoperatively, both groups had similar demographic, functional, and hemodynamic characteristics. Off-CPB patients had significantly shorter surgery times than CPB patients, 188.5 (161.5-213.3) min versus 265.0 (247.5-299.5) min, respectively; p < 0.001. Blood transfusion requirements during surgery and within the postoperative 48 hour period were significantly lower in the off-CPB group than in the CPB group (odds ratio: 5.9; 95% confidence interval: 1.1-31.1, p = 0.042). Compared with the CPB group, the off-CPB group patients had a shorter intubation time, 21 (17.4-48.5) hours versus 41 (20.6-258.4) hours; p = 0.042. Intensive care unit stay was 7.0 (4.75-13.5) days for off-CPB versus 10.0 (6.0-19.0) days for CPB (p = 0.256). The off-CPB approach allows HVAD to be implanted quickly with significantly less perioperative bleeding and transfusion requirements and facilitates postoperative rehabilitation.

Expression of Sirt1 and FoxP3 in classical Hodgkin lymphoma and tumor infiltrating lymphocytes: Implications for immune dysregulation, prognosis and potential therapeutic targeting.

BACKGROUND: Hodgkin Reed-Sternberg (HRS) cells may promote differentiation of CD4+ naïve T cells toward both FoxP3+ T regulatory (Treg) cells and TIA-1+ cytotoxic T lymphocytes (CTL). Previous studies suggest that an overabundance of cytotoxic TIA-1+ cells in relation to FoxP3+ T reg cells portends unfavorable outcomes in classical Hodgkin lymphoma (cHL), raising the possibility that its pathogenesis may be related to immune dysregulation. Sirt1 deacetylates FoxP3 and leads to decreased Treg functionality. Our objective was to compare Sirt1 and FoxP3 expressions in Hodgkin lymphoma infiltrating lymphocytes (HLIL) and confirm Sirt1 expression in HRS cells. DESIGN: Immunohistochemical staining of paraffin-embedded tissue with antibodies to Sirt1, FoxP3, TIA-1, and CD8 was performed. Expression of Sirt1 was assessed in both the HRS cells and in the HLILs in twenty-four cases. Adequate tissue was available in 13 cHL cases to permit the enumeration of FoxP3, TIA-1 and CD8 by giving their percent staining of HLILs. RESULTS: In HLILs, nuclear expression of Sirt1 was 32-88% (mean 67%); FoxP3 expression was 9-40% (mean 23.9%); TIA-1 expression was 15-87% (mean 32%); and CD8 expression was 10-45% (mean = 31%). Sirt1 to FoxP3 ratio was 0.96-5.5 (mean 3.2). TIA-1 to FoxP3 ratio was 0.6-5.1 (mean 1.6). CD8 to FoxP3 ratio was 0.43-3.7 (mean 1.5). There was a difference of Sirt1 to FoxP3 ratios between remission and recurrence groups, being significantly higher in the recurrence group (P = 0.005). Sirt1 demonstrated high nuclear expression in the HRS cells of 21 out of 24 (88%) cases analyzed. CONCLUSION: The relative overexpression of Sirt1 to FoxP3 in HLILs may be considered possible targets for immune modulation. Histone deacetylase inhibitors may increase the efficacy of existing treatment regimens by downregulating SIRT1 gene mRNA/Sirt1 protein function and together with rapamycin could expand the T regulatory/FoxP3 population and functionality and improve prognosis for remission in cHL. Targeting Sirt1 in the HRS cells may facilitate their ability to promote naïve T cell differentiation toward Treg cells over CTL.