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Purpose – The purpose of this paper is to examine monetary policies and bank lending in the emerging economies of Sub-Sahara Africa. Design/methodology/approach – The dynamic system-generalized method of moments (GMM) that overcomes issues of unobserved period and country-specific effects, as well as potential endogeneity of explanatory variables, is applied in the estimation exercise. The study uses the data for 80 banks across 20 Sub-Saharan African countries from 2010 to 2019. Findings – The findings show that expansionary monetary policy such as an increase in money supply stimulates bank lending, while contractionary monetary policies like increase in the monetary policy rates by the central banks lead to credit contraction, albeit a weak effect due to possible underdevelopment of financial markets, institutional constraints, bank concentration and other rigidities in the system characteristic of developing countries that undermine the effectiveness of monetary policy transmission. Capital adequacy ratio and size of economic activities are other variables that significantly influence bank lending channels. Practical Implication – Sub-Sahara Africa countries can enhance the effectiveness of monetary policy transmission on bank lending through the effective use of the transmission mechanism of changes in money supply and monetary policy rate. Originality/value – While greater empirical attention has been devoted to the nexus between monetary policies and macroeconomic variables in country-specific studies, the connection between monetary policies and bank lending at an extensive regional or cross-country level is still scanty. For Sub-Saharan Africa, there is a palpable lack of empirical evidence on this. This study, therefore, seeks to fill this gap in a region where the impact of monetary policies on credit intermediation is crucial to the economic diversification efforts of the governments of Sub-Sahara Africa.

This study seeks to unravel the relationship between national electoral events and industry’s stock market returns using the various presidential elections in Nigeria. The study adopts the traditional Market Model (MM) and testing with the Cumulative Abnormal Return (CAR) approach on the daily market data from the Nigerian Stock Exchange. Evidences abound that banking and Petroleum sector decreases before and increases after all elections. With the same trend for other sectors such as Conglomerates stock prices which oscillated in the same direction for the1999 and 2003; Brewery took their turn 1999 and 2011 while building sector experienced this event effect in 1999, thereby revealing industry connectivity with political activities. This manifests as their stock returns tend to reduce generally before and increase after election periods. We therefore recommend the depoliticization of public policies through strict adherence to corporate governance codes and strengthening of public institutions. This will put a check on the political manoeuvrings of the economy by boosting investors’ confidence on the market regardless of electoral activities and power swings. More importantly, for those stocks that experiences increase in value after election it is a better time to sell those portfolios and buy these stocks that experience loss in value at a post-election window.

CMV infection alters NK cell phenotype and function toward a more memory-like immune state. These cells, termed adaptive NK cells, typically express CD57 and NKG2C but lack expression of the FcRγ-chain (gene: FCER1G, FcRγ), PLZF, and SYK. Functionally, adaptive NK cells display enhanced Ab-dependent cellular cytotoxicity (ADCC) and cytokine production. However, the mechanism behind this enhanced function is unknown. To understand what drives enhanced ADCC and cytokine production in adaptive NK cells, we optimized a CRISPR/Cas9 system to ablate genes from primary human NK cells. We ablated genes that encode molecules in the ADCC pathway, such as FcRγ, CD3ζ, SYK, SHP-1, ZAP70, and the transcription factor PLZF, and tested subsequent ADCC and cytokine production. We found that ablating the FcRγ-chain caused a modest increase in TNF-α production. Ablation of PLZF did not enhance ADCC or cytokine production. Importantly, SYK kinase ablation significantly enhanced cytotoxicity, cytokine production, and target cell conjugation, whereas ZAP70 kinase ablation diminished function. Ablating the phosphatase SHP-1 enhanced cytotoxicity but reduced cytokine production. These results indicate that the enhanced cytotoxicity and cytokine production of CMV-induced adaptive NK cells is more likely due to the loss of SYK than the lack of FcRγ or PLZF. We found the lack of SYK expression could improve target cell conjugation through enhanced CD2 expression or limit SHP-1-mediated inhibition of CD16A signaling, leading to enhanced cytotoxicity and cytokine production., (Copyright © 2023 by The American Association of Immunologists, Inc.)

New treatments are required to enhance current therapies for lung cancer. Mesothelin is a surface protein overexpressed in non-small cell lung cancer (NSCLC) that shows promise as an immunotherapeutic target in phase I clinical trials. However, the immunosuppressive environment in NSCLC may limit efficacy of these therapies. We applied time-of-flight mass cytometry to examine the state of circulating mononuclear cells in fourteen patients undergoing treatment for unresectable lung cancer. Six patients had earlier stage NSCLC (I-IVA) and eight had highly advanced NSCLC (IVB). The advanced NSCLC patients relapsed with greater frequency than the earlier stage patients. Before treatment, patients with very advanced NSCLC had a greater proportion of CD14 - myeloid cells than patients with earlier NSCLC. These patients also had fewer circulating natural killer (NK) cells bearing an Fc receptor, CD16, which is crucial to antibody-dependent cellular cytotoxicity. We designed a high affinity tri-specific killer engager (TriKE ® ) to enhance NK cytotoxicity against mesothelin + targets in this environment. The TriKE consisted of CD16 and mesothelin binding elements linked together by IL-15. TriKE enhanced proliferation of lung cancer patient NK cells in vitro . Lung cancer lines are refractory to NK cell killing, but the TriKE enhanced cytotoxicity and cytokine production by patient NK cells when challenged with tumor. Importantly, TriKE triggered NK cell responses from patients at all stages of disease and treatment, suggesting TriKE can enhance current therapies. These pre-clinical studies suggest mesothelin-targeted TriKE has the potential to overcome the immunosuppressive environment of NSCLC to treat disease., Competing Interests: NF served on the advisory board for Takeda in 2020 and 2021 and the advisory board for Astra Zeneca in 2020. Neither Takeda nor Astra Zeneca provided any funding for the work herein. DV, JM and MF receive research support and, with the University of Minnesota, are shared owners of the TriKE technology licensed by the University to GT Biopharma Inc. In addition, JM and MF consult for and hold stock options in GT BioPharma Inc. These interests have been reviewed and managed by the University of Minnesota in accordance with its conflict of interest policy. The remaining authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2023 Kennedy, Vallera, Ettestad, Hallstrom, Kodal, Todhunter, Bendzick, Hinderlie, Walker, Pulkrabek, Pastan, Kratzke, Fujioka, Miller and Felices.)

The motivation of someone who is locked-in, that is, paralyzed and mute, is to find relief for their loss of function. The data presented in this report is part of an attempt to restore one of those lost functions, namely, speech. An essential feature of the development of a speech prosthesis is optimal decoding of patterns of recorded neural signals during silent or covert speech, that is, speaking "inside the head" with output that is inaudible due to the paralysis of the articulators. The aim of this paper is to illustrate the importance of both fast and slow single unit firings recorded from an individual with locked-in syndrome and from an intact participant speaking silently . Long duration electrodes were implanted in the motor speech cortex for up to 13 years in the locked-in participant. The data herein provide evidence that slow firing single units are essential for optimal decoding accuracy . Additional evidence indicates that slow firing single units can be conditioned in the locked-in participant 5 years after implantation, further supporting their role in decoding., Competing Interests: PK has 98% ownership of Neural Signals Inc. AG is employed by Neural Signals Inc. The remaining author declares that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2022 Ganesh, Cervantes and Kennedy.)

Natural killer (NK) cells are innate immune cells that recognize malignant cells through a wide array of germline-encoded receptors. Triggering of activating receptors results in cytotoxicity and broad immune system activation. The former is achieved through release of cytotoxic granules and presentation of death receptor ligands, while the latter is mediated by inflammatory cytokines, such as interferon-γ and tumor necrosis factor α. Early success with ex vivo activation of NK cells and adoptive transfer suggest they are a safe therapeutic with promising responses in advanced hematologic malignancies. In particular, adoptive NK cell therapies can serve as a 'bridge' to potentially curative allogeneic stem cell transplantation. In addition, strategies are being developed that expand large numbers of cells from limited starting material and mature NK cells from precursors. Together, these make 'off-the-shelf' NK cells possible to treat a wide range of cancers. Research efforts have focused on creating a range of tools that increase targeting of therapeutic NK cells toward cancer-from therapeutic antibodies that drive antibody-dependent cellular cytotoxicity, to chimeric antigen receptors. As these novel therapies start to show promise in clinical trials, the field is rapidly moving toward addressing other challenges that limit NK cell therapeutics and the goal to treat solid tumors. This review describes the state of therapeutic NK cell targeting of tumors; discusses the challenges that need to be addressed before NK cells can be applied as a wide-ranging treatment for cancer; and points to some of the innovations that are being developed to surmount these challenges. Suppressive cells in the tumor microenvironment pose a direct threat to therapeutic NK cells, through presentation of inhibitory ligands and secretion of suppressive cytokines and metabolites. The nutrient- and oxygen-starved conditions under which NK cells must function necessitate an understanding of therapeutic NK cell metabolism that is still emerging. Prior to these challenges, NK cells must find their way into and persist in the tumor itself. Finally, the desirability of a 'single-shot' NK cell treatment and the problems and benefits of a short-lived rejection-prone NK cellular product are discussed., (© 2022. The Author(s).)

Human natural killer (NK) cells in peripheral blood perform many functions, and classification of specific subsets has been a longstanding goal. We report single-cell RNA sequencing of NK cells, comparing gene expression in unstimulated and interleukin (IL)-2-activated cells from healthy cytomegalovirus (CMV)-negative donors. Three NK cell subsets resembled well-described populations; CD56brightCD16-, CD56dimCD16+CD57-, and CD56dimCD16+CD57+. CD56dimCD16+CD57- cells subdivided to include a population with higher chemokine mRNA and increased frequency of killer-cell immunoglobulin-like receptor expression. Three novel human blood NK cell populations were identified: a population of type I interferon-responding NK cells that were CD56neg; a population exhibiting a cytokine-induced memory-like phenotype, including increased granzyme B mRNA in response to IL-2; and finally, a small population, with low ribosomal expression, downregulation of oxidative phosphorylation, and high levels of immediate early response genes indicative of cellular activation. Analysis of CMV+ donors established that CMV altered the proportion of NK cells in each subset, especially an increase in adaptive NK cells, as well as gene regulation within each subset. Together, these data establish an unexpected diversity in blood NK cells and provide a new framework for analyzing NK cell responses in health and disease., (© 2020 by The American Society of Hematology.)

Oncolytic viruses (OVs) can trigger profound innate and adaptive immune responses, which have the potential both to potentiate and reduce the activity of OVs. Natural killer (NK) cells can mediate potent anti-viral and anti-tumoral responses, but there are no data on the role of NK cells in oncolytic adenovirus activity. Here, we have used two different oncolytic adenoviruses-the Ad5 E1A CR2-deletion mutant dl 922-947 (group C) and the chimeric Ad3/Ad11p mutant enadenotucirev (group B)-to investigate the effect of NK cells on overall anti-cancer efficacy in ovarian cancer. Because human adenoviruses do not replicate in murine cells, we utilized primary human NK cells from peripheral blood and ovarian cancer ascites. Our results show that dl 922-947 and enadenotucirev do not infect NK cells, but induce contact-dependent activation and anti-cancer cytotoxicity against adenovirus-infected ovarian cancer cells. Moreover, manipulation of NK receptors DNAM-1 (DNAX accessory molecule-1) and TIGIT (T cell immunoreceptor with Ig and ITIM domains) significantly influences NK cytotoxicity against adenovirus-infected cells. Together, these results indicate that NK cells act to increase the activity of oncolytic adenovirus in ovarian cancer and suggest that strategies to augment NK activity further via the blockade of inhibitory NK receptor TIGIT could enhance therapeutic potential of OVs., (© 2020 The Author(s).)

Genetic diversity in human natural killer (NK) cell receptors is linked to resistance and susceptibility to many diseases. Here, we tested the effect of this diversity on the nanoscale organization of killer cell immunoglobulin-like receptors (KIRs). Using superresolution microscopy, we found that inhibitory KIRs encoded by different genes and alleles were organized differently at the surface of primary human NK cells. KIRs that were found at low abundance assembled into smaller clusters than those formed by KIRs that were more highly abundant, and at low abundance, there was a greater proportion of KIRs in clusters. Upon receptor triggering, a structured interface called the immune synapse assembles, which facilitates signal integration and controls NK cell responses. Here, triggering of low-abundance receptors resulted in less phosphorylation of the downstream phosphatase SHP-1 but more phosphorylation of the adaptor protein Crk than did triggering of high-abundance receptors. In cells with greater KIR abundance, SHP-1 dephosphorylated Crk, which potentiated NK cell spreading during activation. Thus, genetic variation modulates both the abundance and nanoscale organization of inhibitory KIRs. That is, as well as the number of receptors at the cell surface varying with genotype, the way in which these receptors are organized in the membrane also varies. Essentially, a change in the average surface abundance of a protein at the cell surface is a coarse descriptor entwined with changes in local nanoscale clustering. Together, our data indicate that genetic diversity in inhibitory KIRs affects membrane-proximal signaling and, unexpectedly, the formation of activating immune synapses., (Copyright © 2019 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works.)

The particular HLA class I variants an individual carries influences their resistance and susceptibility to a multitude of diseases. Expression level and variation in the peptide binding region correlates with, for example, a person's progression to AIDS after HIV infection. One factor which has not yet been addressed is whether or not different HLA class I proteins organize differently in the cell membrane on a nanoscale. Here, we examined the organization of three HLA-B allotypes (B * 2705, B * 5301, and B * 5701) and two HLA-C allotypes (C * 0602 and C * 0702) in the membrane of 721.221 cells which otherwise lack expression of HLA-B or HLA-C. All these allotypes are ligands for the T cell receptor and leukocyte immunoglobulin-like receptors, but additionally, the HLA-B allotypes are ligands for the killer-cell immunoglobulin-like receptor family member KIR3DL1, HLA-C * 0602 is a ligand for KIR2DL1, and HLA-C * 0702 is a ligand for KIR2DL2/3. Using super-resolution microscopy, we found that both HLA-B and HLA-C formed more clusters and a greater proportion of HLA contributed to clusters, when expressed at lower levels. Thus, HLA class I organization is a covariate in genetic association studies of HLA class I expression level with disease progression. Surprisingly, we also found that HLA-C was more clustered than HLA-B when expression level was controlled. HLA-C consistently formed larger and more numerous clusters than HLA-B and a greater proportion of HLA-C contributed to clusters than for HLA-B. We also found that the organization of HLA class I proteins varied with cell type. T cells exhibited a particularly clustered organization of HLA class I while B cells expressed a more uniform distribution. In summary, HLA class I variants are organized differently in the cell surface membrane which may impact their functions.

Tissue-specific NK cells are abundant in the pregnant uterus and interact with invading placental trophoblast cells that transform the maternal arteries to increase the fetoplacental blood supply. Genetic case-control studies have implicated killer cell Ig-like receptor (KIR) genes and their HLA ligands in pregnancy disorders characterized by failure of trophoblast arterial transformation. Activating KIR2DS1 or KIR2DS5 (when located in the centromeric region as in Africans) lower the risk of disorders when there is a fetal HLA-C allele carrying a C2 epitope. In this study, we investigated another activating KIR, KIR2DS4, and provide genetic evidence for a similar effect when carried with KIR2DS1 KIR2DS4 is expressed by ∼45% of uterine NK (uNK) cells. Similarly to KIR2DS1, triggering of KIR2DS4 on uNK cells led to secretion of GM-CSF and other chemokines, known to promote placental trophoblast invasion. Additionally, XCL1 and CCL1, identified in a screen of 120 different cytokines, were consistently secreted upon activation of KIR2DS4 on uNK cells. Inhibitory KIR2DL5A, carried in linkage disequilibrium with KIR2DS1, is expressed by peripheral blood NK cells but not by uNK cells, highlighting the unique phenotype of uNK cells compared with peripheral blood NK cells. That KIR2DS4, KIR2DS1, and some alleles of KIR2DS5 contribute to successful pregnancy suggests that activation of uNK cells by KIR binding to HLA-C is a generic mechanism promoting trophoblast invasion into the decidua., (Copyright © 2016 The Authors.)

Super-resolution microscopy has revealed that immune cell receptors are organized in nanoscale clusters at cell surfaces and immune synapses. However, mechanisms and functions for this nanoscale organization remain unclear. Here, we used super-resolution microscopy to compare the surface organization of paired killer Ig-like receptors (KIR), KIR2DL1 and KIR2DS1, on human primary natural killer cells and cell lines. Activating KIR2DS1 assembled in clusters two-fold larger than its inhibitory counterpart KIR2DL1. Site-directed mutagenesis established that the size of nanoclusters is controlled by transmembrane amino acid 233, a lysine in KIR2DS1. Super-resolution microscopy also revealed two ways in which the nanoscale clustering of KIR affects signaling. First, KIR2DS1 and DAP12 nanoclusters are juxtaposed in the resting cell state but coalesce upon receptor ligation. Second, quantitative super-resolution microscopy revealed that phosphorylation of the kinase ZAP-70 or phosphatase SHP-1 is favored in larger KIR nanoclusters. Thus, the size of KIR nanoclusters depends on the transmembrane sequence and affects downstream signaling., (Copyright © 2016 The Author(s). Published by Elsevier Inc. All rights reserved.)

Field pea (Pisum sativum L.) is an important grain legume consumed both as human food and animal feed. However, productivity in low rainfall regions can be significantly reduced by inferior soils containing high levels of boron and/or salinity. Furthermore, powdery mildew (PM) (Erysiphe pisi) disease also causes significant yield loss in warmer regions. Breeding for tolerance to these abiotic and biotic stresses are major aims for pea breeding programs and the application of molecular markers for these traits could greatly assist in developing improved germplasm at a faster rate. The current study reports the evaluation of a near diagnostic marker, PsMlo, associated with PM resistance and boron (B) tolerance as well as linked markers associated with salinity tolerance across a diverse set of pea germplasm. The PsMlo1 marker predicted the PM and B phenotypic responses with high levels of accuracy (>80%) across a wide range of field pea genotypes, hence offers the potential to be widely adapted in pea breeding programs. In contrast, linked markers for salinity tolerance were population specific; therefore, application of these markers would be suitable to relevant crosses within the program. Our results also suggest that there are possible new sources of salt tolerance present in field pea germplasm that could be further exploited.

During human pregnancy, fetal trophoblast cells invade the decidua and remodel maternal spiral arteries to establish adequate nutrition during gestation. Tissue NK cells in the decidua (dNK) express inhibitory NK receptors (iNKR) that recognize allogeneic HLA-C molecules on trophoblast. Where this results in excessive dNK inhibition, the risk of pre-eclampsia or growth restriction is increased. However, the role of maternal, self-HLA-C in regulating dNK responsiveness is unknown. We investigated how the expression and function of five iNKR in dNK is influenced by maternal HLA-C. In dNK isolated from women who have HLA-C alleles that carry a C2 epitope, there is decreased expression frequency of the cognate receptor, KIR2DL1. In contrast, women with HLA-C alleles bearing a C1 epitope have increased frequency of the corresponding receptor, KIR2DL3. Maternal HLA-C had no significant effect on KIR2DL1 or KIR2DL3 in peripheral blood NK cells (pbNK). This resulted in a very different KIR repertoire for dNK capable of binding C1 or C2 epitopes compared with pbNK. We also show that, although maternal KIR2DL1 binding to C2 epitope educates dNK cells to acquire functional competence, the effects of other iNKR on dNK responsiveness are quite different from those in pbNK. This provides a basis for understanding how dNK responses to allogeneic trophoblast affect the outcome of pregnancy. Our findings suggest that the mechanisms that determine the repertoire of iNKR and the effect of self-MHC on NK education may differ in tissue NK cells compared with pbNK., (Copyright © 2015 The Authors.)

Natural killer (NK) cells discriminate between healthy and unhealthy target cells through a balance of activating and inhibitory signals at direct intercellular contacts called immune synapses. Rearrangements in the cellular cytoskeleton have long been known to be critical in assembly of immune synapses. Here, through bringing together the vast literature on this subject, the number of different ways in which the cytoskeleton is important becomes evident. The dynamics of filamentous actin are critical in (i) creating the nanometer-scale organization of NK cell receptors, (ii) establishing cellular polarity, (iii) coordinating immune receptor and integrin-mediated signaling, and (iv) directing secretion of lytic granules and cytokines. The microtubule network also is important in the delivery of lytic granules and vesicles containing cytokines to the immune synapse. Together, these data establish that the cytoskeleton acts as a central regulator of this complex and dynamic process - and an enormous amount of NK cell biology is controlled through the cytoskeleton., (© 2013 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

Reduced trophoblast invasion and vascular conversion in decidua are thought to be the primary defect of common pregnancy disorders including preeclampsia and fetal growth restriction. Genetic studies suggest these conditions are linked to combinations of polymorphic killer cell Ig-like receptor (KIR) genes expressed by maternal decidual NK cells (dNK) and HLA-C genes expressed by fetal trophoblast. Inhibitory KIR2DL1 and activating KIR2DS1 both bind HLA-C2, but confer increased risk or protection from pregnancy disorders, respectively. The mechanisms underlying these genetic associations with opposing outcomes are unknown. We show that KIR2DS1 is highly expressed in dNK, stimulating strong activation of KIR2DS1+ dNK. We used microarrays to identify additional responses triggered by binding of KIR2DS1 or KIR2DL1 to HLA-C2 and found different responses in dNK coexpressing KIR2DS1 with KIR2DL1 compared with dNK only expressing KIR2DL1. Activation of KIR2DS1+ dNK by HLA-C2 stimulated production of soluble products including GM-CSF, detected by intracellular FACS and ELISA. We demonstrated that GM-CSF enhanced migration of primary trophoblast and JEG-3 trophoblast cells in vitro. These findings provide a molecular mechanism explaining how recognition of HLA class I molecules on fetal trophoblast by an activating KIR on maternal dNK may be beneficial for placentation.

The major leukocyte population in the decidua during the first trimester of pregnancy consists of NK cells that express receptors capable of recognizing MHC class I molecules expressed by placental trophoblast. These include members of the killer immunoglobulin-like receptor (KIR) family, the two-domain KIR (KIR2D), which recognize HLA-C. Interactions between decidual NK (dNK) cell KIR2D and placental HLA-C contribute to the success of pregnancy and dNK cells express KIR2D at higher frequency than peripheral NK (pNK) cells. Thus, they are biased toward recognizing HLA-C. In order to investigate when this unusual KIR repertoire appears, we compared the phenotype of NK cells isolated from non-pregnant (endometrium) and pregnant (decidua) human uterine mucosa. Endometrial NK (eNK) cells did not express KIR2D at a higher level than matched pNK cells, so the bias toward HLA-C recognition occurs as a response to pregnancy. Furthermore, HLA-C expression was upregulated on uterine stromal cells as the mucosa transformed from endometrium to decidua at the onset of pregnancy. As uterine NK (uNK) cells can mature from NK precursors and acquire KIR expression in utero, the pregnancy-specific bias of uNK cells toward HLA-C recognition could arise as developing uNK cells interact with uterine stromal cells, which express higher levels of HLA-C during pregnancy., (Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

We conducted a neurophysiological study of attempted speech production in a paralyzed human volunteer using chronic microelectrode recordings. The volunteer suffers from locked-in syndrome leaving him in a state of near-total paralysis, though he maintains good cognition and sensation. In this study, we investigated the feasibility of supervised classification techniques for prediction of intended phoneme production in the absence of any overt movements including speech. Such classification or decoding ability has the potential to greatly improve the quality-of-life of many people who are otherwise unable to speak by providing a direct communicative link to the general community. We examined the performance of three classifiers on a multi-class discrimination problem in which the items were 38 American English phonemes including monophthong and diphthong vowels and consonants. The three classifiers differed in performance, but averaged between 16 and 21% overall accuracy (chance-level is 1/38 or 2.6%). Further, the distribution of phonemes classified statistically above chance was non-uniform though 20 of 38 phonemes were classified with statistical significance for all three classifiers. These preliminary results suggest supervised classification techniques are capable of performing large scale multi-class discrimination for attempted speech production and may provide the basis for future communication prostheses.

This paper briefly reviews current silent speech methodologies for normal and disabled individuals. Current techniques utilizing electromyographic (EMG) recordings of vocal tract movements are useful for physically healthy individuals but fail for tetraplegic individuals who do not have accurate voluntary control over the speech articulators. Alternative methods utilizing EMG from other body parts (e.g., hand, arm, or facial muscles) or electroencephalography (EEG) can provide capable silent communication to severely paralyzed users, though current interfaces are extremely slow relative to normal conversation rates and require constant attention to a computer screen that provides visual feedback and/or cueing. We present a novel approach to the problem of silent speech via an intracortical microelectrode brain computer interface (BCI) to predict intended speech information directly from the activity of neurons involved in speech production. The predicted speech is synthesized and acoustically fed back to the user with a delay under 50 ms. We demonstrate that the Neurotrophic Electrode used in the BCI is capable of providing useful neural recordings for over 4 years, a necessary property for BCIs that need to remain viable over the lifespan of the user. Other design considerations include neural decoding techniques based on previous research involving BCIs for computer cursor or robotic arm control via prediction of intended movement kinematics from motor cortical signals in monkeys and humans. Initial results from a study of continuous speech production with instantaneous acoustic feedback show the BCI user was able to improve his control over an artificial speech synthesizer both within and across recording sessions. The success of this initial trial validates the potential of the intracortical microelectrode-based approach for providing a speech prosthesis that can allow much more rapid communication rates.

Background: Brain-machine interfaces (BMIs) involving electrodes implanted into the human cerebral cortex have recently been developed in an attempt to restore function to profoundly paralyzed individuals. Current BMIs for restoring communication can provide important capabilities via a typing process, but unfortunately they are only capable of slow communication rates. In the current study we use a novel approach to speech restoration in which we decode continuous auditory parameters for a real-time speech synthesizer from neuronal activity in motor cortex during attempted speech., Methodology/principal Findings: Neural signals recorded by a Neurotrophic Electrode implanted in a speech-related region of the left precentral gyrus of a human volunteer suffering from locked-in syndrome, characterized by near-total paralysis with spared cognition, were transmitted wirelessly across the scalp and used to drive a speech synthesizer. A Kalman filter-based decoder translated the neural signals generated during attempted speech into continuous parameters for controlling a synthesizer that provided immediate (within 50 ms) auditory feedback of the decoded sound. Accuracy of the volunteer's vowel productions with the synthesizer improved quickly with practice, with a 25% improvement in average hit rate (from 45% to 70%) and 46% decrease in average endpoint error from the first to the last block of a three-vowel task., Conclusions/significance: Our results support the feasibility of neural prostheses that may have the potential to provide near-conversational synthetic speech output for individuals with severely impaired speech motor control. They also provide an initial glimpse into the functional properties of neurons in speech motor cortical areas.

We describe the use of human cortical control signals to operate two assistive technology tools--a virtual keyboard speller and a computer-simulated digit. The cortical signals used for control are local field potentials recorded through an implanted neurotrophic electrode. In this system, the patients' cortical signals are transmitted wirelessly to a receiver and translated by computer software into either a computer cursor movement (for the virtual keyboard) or flexion of a cyber digit on a virtual hand. This report focuses on the progress of two subjects toward effective use of their "virtual" neuro-prosthetic devices to meet their assistive technology needs.

This paper is a first attempt to present a "decision tree" to assist in choosing a brain-computer interface device for patients who are nearly or completely "locked-in" (cognitively intact but unable to move or communicate.) The first step is to assess any remaining function. There are six inflexion points in the decision-making process. These depend on the functional status of the patient: 1) some residual movement; 2) no movement, but some residual electromyographic (EMG) activity; 3) fully locked-in with no EMG activity or movements but with conjugate eye movements; 4) same as 3 but with disconjugate eye movements; 5) same as 4 but with inadequate assistance from the available EEG-based systems; 6) same as 5 and accepting of an invasive system.

Purpose: Trastuzumab combined with chemotherapy improves outcomes for women with human epidermal growth factor receptor 2 (HER2) overexpressing advanced breast cancer. We conducted a pilot study of preoperative trastuzumab and paclitaxel, followed by surgery and adjuvant doxorubicin and cyclophosphamide chemotherapy in earlier stage breast cancer., Patients and Methods: Patients with HER2-positive (2+ or 3+ by immunohistochemistry) stage II or III breast cancer received preoperative trastuzumab (4 mg/kg x 1, then 2 mg/kg/wk x 11) in combination with paclitaxel (175 mg/m(2) every 3 weeks x 4). Patients received adjuvant doxorubicin and cyclophosphamide chemotherapy following definitive breast surgery. Clinical and pathologic response rates were determined after preoperative therapy. Left ventricular ejection fraction and circulating levels of HER2 extracellular domain were measured serially., Results: Preoperative trastuzumab and paclitaxel achieved clinical response in 75% and complete pathologic response in 18% of the 40 women on study. HER2 3+ tumors were more likely to respond than 2+ tumors (84% v 38%). No unexpected treatment-related noncardiac toxicity was encountered. Four patients developed grade 2 cardiotoxicity (asymptomatic declines in left ventricular ejection fraction). Baseline HER2 extracellular domain was elevated in 24% of patients and declined with preoperative therapy. Immunohistochemical analyses of posttherapy tumor specimens indicated varying patterns of HER2 expression following trastuzumab-based treatment., Conclusion: Preoperative trastuzumab and paclitaxel is active against HER2 overexpressing early-stage breast cancer and may be feasible as part of a sequential treatment program including anthracyclines. The observed changes in cardiac function merit further investigation. Correlative analyses of HER2 status may facilitate understanding of tumor response and resistance to targeted therapy.

A serum- and steroid-free primary culture system was developed for the maintenance and automated analysis of cerebellar granule cell viability. Conventional poly-lysine coated 96-well tissue culture plates serve as a platform for growth, experimental manipulation and subsequent automated analysis of these primary cultured neurons. Cerebellar granule neurons were seeded at densities ranging from 2 x 10(4) to 1.25 x 10(6) cells/cm(2) and maintained in serum- and steroid-free culture conditions for 7 days. Viability was subsequently determined by the reduction of [3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium (MTS), and the degree of cell death occurring over that period was determined by the release of lactate dehydrogenase (LDH). At appropriate cell densities, the results of the MTS reduction and LDH release assays were directly proportional to the initial number of cerebellar granule cells plated. Those results indicate that an initial cell density of 0.5 - 1.0 x 10(5) cells per well (0.32 cm(2)) was appropriate for simultaneous analysis with the MTS reduction and LDH release assays. Both assays were then used to demonstrate the utility of this model system for analysis of tert-butyl-hydroperoxide and hydrogen peroxide induced oxidative stress. Additionally, the MTS reduction assay was used to demonstrate that the NMDA-receptor selective antagonist MK-801 was neuroprotective against glutamate-mediated excitotoxicity. This study defines a powerful and flexible primary culture system for cerebellar neurons that is useful for high-throughput analysis of factors that influence neuronal viability.

We describe an invasive alternative to externally applied brain-computer interface (BCI) devices. This system requires implantation of a special electrode into the outer layers of the human neocortex. The recorded signals are transmitted to a nearby receiver and processed to drive a cursor on a computer monitor in front of the patient. Our present patient has learned to control the cursor for the production of synthetic speech and typing.

Patients with severe paralysis of limbs, face and vocal apparatus may be intelligent and aware and yet, tragically, unable to communicate. We describe a communication link for such a 'locked-in' patient with amyotrophic lateral sclerosis. We recorded action potentials in her brain over several months by means of an electrode that induces growth of myelinated fibers into its recording tip. She was able to control the neural signals in an on/off fashion. This result is an important step towards providing such patients with direct control of their environment by interfacing with a computer. Additionally, it indicates that restoration of paralyzed muscles may be possible by using the signals to control muscle stimulators.

Studies using continuous recording of neural activity during long-term learning are now possible with an implanted neurotrophic electrode. During recording of individual cortical action potentials in monkeys performing a reach and grasp task, we were able to follow the gradual change in firing of several action potentials as the task was learned. Control experiments suggest that the neurons involved in the learning were initially silent.

The relationship between intracellular Ca2+ and glucose production in the liver during early and late states of hemorrhagic shock was studied. Rats were anesthetized with intraperitoneal sodium pentobarbital and both femoral arteries and one femoral vein were cannulated. Rats were divided into two groups. One group was subjected to hemorrhagic shock by rapid withdrawal of blood to a mean arterial pressure of 40 mm Hg and maintained in shock for either 30 or 150 min. Rats in the control group were observed for the same time period. Hepatic glucose production was evaluated in both groups by a nonrecirculating liver perfusion model with and without lactate as a substrate. Intracellular free Ca2+ in hepatocytes was measured using the Ca2+ selective indicator Fura-2, under basal and epinephrine-stimulated conditions. Hyperglycemia and hyperlacticacidemia were observed in vivo at 30 min of hemorrhagic shock, whereas hypoglycemia and hyperlacticacidemia were observed at 150 min of shock. Hepatic glucose production in isolated perfused livers was significantly depressed at 30 min in animals subjected to shock (P less than 0.05). Lactate-induced glucose production was significantly attenuated at 30 and 150 min (P less than 0.05). Basal Ca2+, in isolated hepatocytes, at 30 and 150 min of hemorrhagic shock was significantly (P less than 0.05) higher than in controls. The hemorrhagic shock rat hepatocytes failed to evaluate intracellular free Ca2+ upon stimulation with 10(-5) M epinephrine. These results demonstrate that hemorrhagic shock is associated with an increase in hepatocyte intracellular Ca2+ concentration along with attenuation of hormone-mediated mobilization of calcium and substrate specific stimulation of hepatic glucose production.

The achievement of long-term recording of neural signals from the central nervous system has potential clinical and investigative application. To facilitate long-term recording, a novel cone electrode composed of an insulated gold wire within a hollow glass cone had been developed. Cone electrodes containing sciatic nerve or neurotrophic medium were implanted into cerebral cortex in rats and monkeys. Electrophysiologic recordings had been previously obtained from cone tissue for as long as 15 months following implantation and this tissue contained silver-positive processes. We now extend these observations to characterize the fine structural features of the tissue within these long-term implants. Electron microscopy revealed central myelinated axons, dendrites, synaptic profiles, blood vessels, and glia; peripheral nerve was not found in the cones in which sciatic nerve had been placed. These observations further suggest ingrowth of cortical neurites and elements into the hollow glass tip of the cone and support the feasibility of long-term recording using this electrode.

Long-term recording of stable action potentials with a new electrode configuration has been achieved for up to 15 months in monkeys. Action potentials are separated from the continuous multi-unit recordings made between two wires inside a glass open ended cone implanted in the motor cortex. Neural tissue is induced to grow into the glass cone by autologous sciatic nerve placed inside prior to implantation. Data presented here show that behavioral correlates of neural activity are related to flexion and extension movements of the contralateral hand and digits. These data suggest that this electrode can be used in both basic and applied studies.

Fibrin glue is an effective hemostatic agent in a variety of clinical situations; its utility is limited by potential transmission of viral infection. We studied the bactericidal properties of fibrin gel (FG) in a murine contaminated hepatic injury model and in vitro by agar plate culture method. Intra-abdominal abscess formation and adhesion rate were assessed following controlled liver injury in association with abdominal contamination with 10(7) Bacteroides fragilis and hepatorrhaphy (H, n = 15) or FG (n = 12). Animals treated by hepatorrhaphy had a significantly greater intra-abdominal abscess rate (15/15 vs. 4/12, p less than 0.05) and adhesion rate (14/15 vs. 6/12, p less than 0.05) than animals treated with FG. Fibrin gel is bactericidal to Bacteroides fragilis, Enterobacter faecium, Escherichia coli, and Staphylococcus aureus but has no effect against Klebsiella pneumoniae or Pseudomonas aeruginosa; the plasma component appears active. Fibrin gel demonstrates significant improvement in adhesion formation and intra-abdominal abscess rate when compared with suture hepatorrhaphy. Fibrin gel appears protective in contaminated hepatic injury.

Sepsis produces profound hypothyroidism. This hypothyroid state is associated with altered lung metabolism and structural integrity. We studied the respiratory function of rats during sepsis-induced hypothyroidism with or without T3 treatment. Forty-four male Holtzman rats underwent cecal ligation and puncture (CLP). Treatment was administered at six hours after surgery consisting of intraperitoneal injection of T3 (15 micrograms/kg, n = 19) or saline (n = 25). At 20 hours (Group A) or 30 hours (Group B) following CLP, respiratory drive was assessed by serial occlusion pressure technique (P0.1). The rats were killed and static elastance determined by serial air inflation to 10 cc. The lungs were excised for weight determination. The P0.1 values were significantly greater in T3-treated animals over controls in Group A (9.3 +/- 0.7 vs. 6.6 +/- 2.2, p less than 0.05 by t test); elastance was significantly improved by T3 treatment in Group B (p less than 0.05 by two-way ANOVA). Lung weight, pH, pO2, pCO2, respiratory rate (RR), and mortality were not significantly different between groups. Control animals were hypothyroid by 20 hours after CLP (T3 less than 12.5 ng/dL) whereas T3-treated animals were euthyroid (T3 = 145 +/- 43 ng/dL). Pulmonary dysfunction frequently accompanies sepsis; the euthyroid state appears protective. We found a significantly improved respiratory drive in septic animals with T3 treatment. Lung elastance was similarly improved in late sepsis with T3 treatment. The data suggest that T3 treatment preserves respiratory function in septic rats as evidenced by respiratory drive and compliance.

There has been a dispute about the corticospinal and rubrospinal tracts for about 100 years. Both are descending motor pathways and have remarkably similar functional properties. It has been proposed previously that each system is primarily active in different movement contexts. The corticospinal tract is most involved when a new movements is being learnt, while the rubrospinal tract is preferentially active when automated movements are being executed. However, what structure decides which system should be in use? In this article Philip Kennedy discusses the evidence that the rubro-olivary tract switches between the two systems depending on the context of the movement.

Using X-rays to improve accuracy of stereotaxic implantation of the brain stem of Macaca irus monkeys overcomes the problems of moveable brain stem and inaccurate fixation in the stereotaxic frame. The method is independent of standard atlases and correct ear bar fixation. The key to the method is the establishment of a nomogram which relates the implantation target to bony landmarks. The nomogram is established by X-ray contrast studies which outline the brain stem, the implantation target in the brain stem being decided by superimposed histology. This target is nomographically related to bony landmarks seen both on the contrast X-ray and on a plain X-ray taken later at implantation with the monkey in the stereotaxic frame. Being able to locate the target on this plain X-ray, and having included on the X-ray a metal marker, the stereotaxic coordinates of which are known, the distance can be measured (allowing for X-ray magnification) between target and stereotaxic marker and thus one computes the target coordinates. Accuracy of implantation according to these coordinates is monitored with further plain X-rays.

A new method for reversible cooling of the inferior olivary nucleus has been used in chronically prepared monkeys. Local olivary cooling depressed discharge of complex spikes of Purkinje cells in contralateral cerebellar cortex. Selective cooling of the principal olive (lateral and dorsal lamellae) produced movement oscillations at about 3-5 Hz of the contralateral arm during cooling in a monkey trained to make prescribed arm movements in the horizontal plane. The effects resemble those of dentate dysfunction. Selective cooling of the dorsal accessory olive and/or the overlying reticular formation, in 3 monkeys, produced during cooling a tendency for postural drift of the contralateral arm and for reduction of its movement amplitudes. These changes tended to vary together according to the degree of cooling. Arm oscillations did not occur. It is concluded that climbing fiber projections from the principal olivary nucleus are essential in the primate for optimal neocerebellar control of arm movements.

To assess the role of the parvocellular division of the red nucleus in motor control, rats were operantly conditioned to walk on a rotating bar and their red nuclei were lesioned with the fiber sparing agent, quinolinic acid. Since both parvocellular and magnocellular divisions of the red nucleus overlap in the rat, they both became involved in this lesion. To differentiate between them, two paradigms were used. (1) Prior to the lesion, the magnocellular division was dysfunctioned by transecting its spinal output, namely, the rubrospinal tract, in the dorso-lateral funiculus (DLF) of the spinal cord. After compensation for this transection had occurred in a few days, the red nucleus was lesioned with quinolinic acid. Rats again compensated rapidly, suggesting that the remaining red nuclear outflow systems, such as the rubro-olivary tract, play no detectable role in the control of on-going movements. (2) In the second paradigm, the red nucleus was lesioned without a preceding DLF transection. This lesion involved both the rubro-bulbar and rubro-spinal projections. Rats did not compensate, or did so very slowly. For compensation to occur, therefore, rubro-bulbar projections need to be intact. This suggests that such projections, that include the rubro-olivary tract, play a role in the compensation for DLF transections.

Single cells were recorded in the magnocellular red nucleus (RNm) of two cynomolgus monkeys using tungsten microelectrodes. The first monkey was trained to press finger switches and to operate a push-pull device. Comparison of responses while operating the two devices demonstrated a strong distal bias. The finger device elicited large modulations in discharge (greater than or equal to 50 impulses/s) in 75% of the sampled neurons. Most cells fired optimally during thumb switch operation, but also fired vigorously in association with other switch operations. The left motor cortex was removed from the second monkey 18 months prior to microelectrode recording. Cells in the cortically denervated RNm discharged vigorously in association with grouped finger movements that opened and closed the affected right hand. These results coupled with our previous findings suggest that the RNm is preferentially linked to distal limb muscles, and the primary role of the forelimb zone may be to control coordinated hand function including grouped movements of the fingers.

A new technique is described for accurate, reliable measurement of eyeball retraction in the rabbit. A narrow film strip, on which a linear light intensity grating has been exposed, is attached to a contact lens which is placed on the animal's cornea. The other end of the intensity grating slides between a photodiode and an LED. The contact lens-film grating assembly moves freely with eyeball retraction and relaxation, causing changes in photodiode output. This device appears to be well tolerated by the animal. Large amplitude eyeball retractions occur in response to air puff stimulation directed at the upper or lower eyelid and to periorbital shock. Average eye retraction latency to stimulation of the abducens (VI) nerve with a chronically implanted stimulating electrode was 5.3 ms (S.D. = 0.75 ms) in the conscious rabbit as measured with our device. Latency to periorbital electrical shock was 9.3 ms (S.D. = 2.1 ms). Eye retraction latency decreased with increasing shock amplitudes. Rabbits readily acquired classically conditioned eyeball retractions, monitored with this device, when a white noise auditory stimulus was paired with an air puff directed at the eyelid.

Use of programmed movements seems to depend on comprehension of the required behavior of which the movements are part. Once this understanding becomes evident by correct behavior, smooth movement take-offs and landings are programmed together. Monkeys were trained to perform a step-tracking task that required accurate self-paced elbow movements of moderate speed. Behavioral aspects of the task, such as correct successive movement directions and timing, were all learned at about the same rates. Use of programmed movements however, increased only after these behavioral requirements had been learned to near the 50% level, i.e., the beginning of behavioral sureness. Movements were programmed as a whole, accelerations together with decelerations, from earliest training onwards.

A novel long-term recording electrode combines neural regeneration with a standard wire recording technique. The electrode consists of an insulated gold wire fixed inside a hollow glass cone. A piece of sciatic nerve is placed in the glass cone before implantation in cortex of rat. Cortical neurites grow into the sciatic nerve in the cone from surrounding neurons and their electrical activity is recorded via the wire (or wires) in the cone. This activity increases in amplitude over the first few weeks after implantation and remains stable until termination of the experiment many months later. Activity of both single and multi units has been recorded. The cone electrode opens unique opportunities for studies of neurite growth in vivo, for plasticity studies on a captive set of neurites, for studying the neural correlates of behavior and motor learning, and for accessing the central nervous systems of patients with severe paralysing and communicative disorders.

Single unit recording in awake monkeys was used to search for functional differences between the two divisions of the red nucleus, and anatomical tracing of WGA-HRP was used to investigate inputs to the two divisions. We studied a total of 323 units in 4 red nuclei of two monkeys. Recording sites were identified in histological sections by the locations of lesions and the reconstruction of electrode tracks. Of the units in the RNm 98.5% discharged in high frequency bursts during movement. Only 52% showed reliable responses to somatosensory stimulation, and the responses observed were weaker than the movement-related discharge. None of the units recorded in the RNp showed strong movement-related discharge, and 51% were completely unresponsive during both motor and sensory tests. A dorsolateral group of medium-sized cells that overlaps the rostral half of the main RNm and the caudal pole of RNp appears to represent an extension of the magnocellular region. Retrograde transport of WGA-HRP indicated that some of these cells are rubrospinal neurons. Furthermore, the discharge properties of dorsolateral neurons are like the main RNm neurons, except for lower discharge rates and smaller spike amplitudes. Mouth movements are strongly represented in the dorsolateral region. Anterograde transport of WGA-HRP from the motor cortex demonstrated dense terminal label in RNp as contrasted with light label in RNm. Retrograde transport of WGA-HRP from RNm labeled many more cells in the cerebellar interpositus nucleus than in motor cortex. We concluded that input to RNm from the cerebellum is the likely source of the strong movement-related activity recorded from cells in the RNm. The absence of appreciable movement-related activity in parvicellular red nucleus provides a clear functional distinction between this division and the magnocellular division of the red nucleus.