Discovery and Functional Characterization of hPT3, a Humanized Anti-Phospho Tau Selective Monoclonal Antibody

BACKGROUND

As a consequence of the discovery of an extracellular component responsible for the progression of tau pathology, tau immunotherapy is being extensively explored in both preclinical and clinical studies as a disease modifying strategy for the treatment of Alzheimer's disease.

OBJECTIVE

Describe the characteristics of the anti-phospho (T212/T217) tau selective antibody PT3 and its humanized variant hPT3.

METHODS

By performing different immunization campaigns, a large collection of antibodies has been generated and prioritized. In depth, in vitro characterization using surface plasmon resonance, phospho-epitope mapping, and X-ray crystallography experiments were performed. Further characterization involved immunohistochemical staining on mouse- and human postmortem tissue and neutralization of tau seeding by immunodepletion assays.

RESULTS AND CONCLUSION

Various in vitro experiments demonstrated a high intrinsic affinity for PT3 and hPT3 for AD brain-derived paired helical filaments but also to non-aggregated phospho (T212/T217) tau. Further functional analyses in cellular and in vivo models of tau seeding demonstrated almost complete depletion of tau seeds in an AD brain homogenate. Ongoing trials will provide the clinical evaluation of the tau spreading hypothesis in Alzheimer's disease.

Abstract 3813: Development of JNJ-64164711, a low fucose anti-GITR antibody for enhanced depletion of tumor regulatory T cells (Tregs)

Background: Checkpoint blockade of PD-1/PDL-1 or CTLA-4 has demonstrated clinical benefit in a subset of cancer patients (pts). To further improve the outcome, approaches to deplete immunosuppressive Tregs are being developed. Emerging evidence supports that the TNF receptor superfamily member 18 (TNFRSF18 or GITR) is highly expressed on intratumoral (i.t.) Tregs with limited expression on effector T cells or circulating immune cells (1,2). This differential expression allows for development of monoclonal antibody (mAb) therapies that eliminate this population while sparing other immune subsets. Herein we characterize JNJ-64164711 (JNJ-711), a fully human anti-GITR mAb being developed to selectively deplete GITR+ Tregs and expand the population of pts that may respond to immunotherapy.

Methods: Treg frequency and GITR expression on human cancer specimens was performed by IHC and multicolor flow cytometric analysis (FC). JNJ-711 was assessed for binding to GITR (human and cyno) and human Fcγ receptors, and inhibition of hGITRL binding to hGITR. The JNJ-711 binding epitope was mapped by hydrogen-deuterium exchange. JNJ-711 functional activity was determined by 1) an NF-kB reporter assay, 2) antibody dependent cellular cytotoxicity (ADCC) on GITR+ cell lines, and 3) JNJ-711 mediated Treg depletion in primary pts tumor samples.

Results: GITR expression prevalence was evaluated by IHC in multiple solid tumors. Immune cell GITR expression was observed in head and neck (HN), esophageal (ESO), non-small cell lung carcinoma (NSCLC), colorectal (CRC) and prostate cancers. GITR was moderately expressed on HN and ESO tumor cells. GITR expression (by FC) was higher on tumor Tregs versus other T cell populations in the tumor and periphery across NSCLC, CRC, ovarian and renal cell carcinoma samples. GITR was differentially higher on i.t. effector Tregs (eTreg) whereas CCR4 was highest on CD4+ T cells in circulation. JNJ-711 binds to hGITR on cells with high affinity [KD= 180 pM], has a log greater affinity to FcγRIIIa [KD= 37 nM on 158V; KD= 180 nM on 158F], a slower dissociation rate than most GITR agonist (Ag) mAb tested [Koff= 5.47 x 10-4 s-1 for Fab], and binds to the CRD1 of GITR. Unlike other GITR Ag mAbs tested, JNJ-711 does not block GITR interaction with GITRL. JNJ-711 demonstrates higher ADCC mediated cell depletion than other GITR Ag mAbs in clinical development on 1) GITR+ hematologic tumor cell lines (HuT102, KMS-12-BM, RPMI 8226, JJN-3), 2) primary activated GITR+ T cells, and 3) in vitro expanded Tregs. Using dissociated primary pts samples, JNJ-711 selectively depleted i.t. eTregs.

Conclusion: JNJ-64164711 selectively depletes hGITR+ cells including Tregs and has potential to enhance antitumor immune response. This antibody is being evaluated for clinical development.

References:

1. Asma et al. Tumor Biol 2015;36:3727-34.

2. Pedroza-Gonzalez et al. OncoImmunology 2015;4:12, e1051297.

Citation Format: Cam V. Holland, John Kehoe, Judith Hailey, Rupesh Nanjunda, Eilyn Lacy, Robin Ernst, Di Zhang, Sam Wu, Alexey Teplyakov, Weimin Li, Michelle Kinder, Edward W. Thompson, Patrick Wilkinson, Jackson Wong, Gerald Chu, Linda Okonkwo, John D. Alvarez, Anhco Nguyen, Iqbal S. Grewal, Moitreyee Chatterjee-Kishore, Mark Salvati, Marco Gottardis. Development of JNJ-64164711, a low fucose anti-GITR antibody for enhanced depletion of tumor regulatory T cells (Tregs) [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 3813.

Functional, Biophysical, and Structural Characterization of Human IgG1 and IgG4 Fc Variants with Ablated Immune Functionality

Engineering of fragment crystallizable (Fc) domains of therapeutic immunoglobulin (IgG) antibodies to eliminate their immune effector functions while retaining other Fc characteristics has numerous applications, including blocking antigens on Fc gamma (Fcγ) receptor-expressing immune cells. We previously reported on a human IgG2 variant termed IgG2σ with barely detectable activity in antibody-dependent cellular cytotoxicity, phagocytosis, complement activity, and Fcγ receptor binding assays. Here, we extend that work to IgG1 and IgG4 antibodies, alternative subtypes which may offer advantages over IgG2 antibodies. In several in vitro and in vivo assays, the IgG1σ and IgG4σ variants showed equal or even lower Fc-related activities than the corresponding IgG2σ variant. In particular, IgG1σ and IgG4σ variants demonstrate complete lack of effector function as measured by antibody-dependent cellular cytotoxicity, complement-dependent cytotoxicity, antibody-dependent cellular phagocytosis, and in vivo T-cell activation. The IgG1σ and IgG4σ variants showed acceptable solubility and stability, and typical human IgG1 pharmacokinetic profiles in human FcRn-transgenic mice and cynomolgus monkeys. In silico T-cell epitope analyses predict a lack of immunogenicity in humans. Finally, crystal structures and simulations of the IgG1σ and IgG4σ Fc domains can explain the lack of Fc-mediated immune functions. These variants show promise for use in those therapeutic antibodies and Fc fusions for which the Fc domain should be immunologically "silent".

Epitope mapping and structural basis for the recognition of phosphorylated tau by the anti-tau antibody AT8

Microtubule‐associated protein tau becomes abnormally phosphorylated in Alzheimer's disease and other tauopathies and forms aggregates of paired helical filaments (PHF‐tau). AT8 is a PHF‐tau‐specific monoclonal antibody that is a commonly used marker of neuropathology because of its recognition of abnormally phosphorylated tau. Previous reports described the AT8 epitope to include pS202/pT205. Our studies support and extend previous findings by also identifying pS208 as part of the binding epitope. We characterized the phosphoepitope of AT8 through both peptide binding studies and costructures with phosphopeptides. From the cocrystal structure of AT8 Fab with the diphosphorylated (pS202/pT205) peptide, it appeared that an additional phosphorylation at S208 would also be accommodated by AT8. Phosphopeptide binding studies showed that AT8 bound to the triply phosphorylated tau peptide (pS202/pT205/pS208) 30‐fold stronger than to the pS202/pT205 peptide, supporting the role of pS208 in AT8 recognition. We also show that the binding kinetics of the triply phosphorylated peptide pS202/pT205/pS208 was remarkably similar to that of PHF‐tau. The costructure of AT8 Fab with a pS202/pT205/pS208 peptide shows that the interaction interface involves all six CDRs and tau residues 202–209. All three phosphorylation sites are recognized by AT8, with pT205 acting as the anchor. Crystallization of the Fab/peptide complex under acidic conditions shows that CDR‐L2 is prone to unfolding and precludes peptide binding, and may suggest a general instability in the antibody. Proteins 2016; 84:427–434. © 2016 The Authors. Proteins: Structure, Function, and Bioinformatics Published by Wiley Periodicals, Inc.

One sensor acoustic emission localization in plates

Acoustic emissions are elastic waves accompanying damage processes and are therefore used for monitoring the health state of structures. Most of the traditional acoustic emission techniques use a trilateration approach requiring at least three sensors on a 2D domain in order to localize sources of acoustic emission events. In this paper, we present a new approach which requires only a single sensor to identify and localize the source of acoustic emissions in a finite plate. The method proposed makes use of the time reversal principle and the dispersive nature of the flexural wave mode in a suitable frequency band. The signal shape of the transverse velocity response contains information about the propagated paths of the incoming elastic waves. This information is made accessible by a numerical time reversal simulation. The effect of dispersion is reversed and the original shape of the flexural wave is restored at the origin of the acoustic emission. The time reversal process is analyzed first for an infinite Mindlin plate, then by a 3D FEM simulation which in combination results in a novel acoustic emission localization process. The process is experimentally verified for different aluminum plates for artificially generated acoustic emissions (Hsu-Nielsen source). Good and reliable localization was achieved for a homogeneous quadratic aluminum plate with only one measurement.

Efecto de la quema controlada sobre el banco de semillas de gramíneas en diferentes parches del bosque de caldén en la región semiárida central Argentina

El banco de semillas del suelo es la principal reserva de propágulos con que cuenta una comunidad vegetal para su mantenimiento, regeneración y perpetuación. Las quemas controladas pueden producir cambios en su composición y distribución. El objetivo del presente trabajo fue evaluar y comparar el comportamiento del banco de semillas germinable de gramíneas en una región del caldenal antes y después de producida una quema controlada. Se delimitaron 5 parches de vegetación dominados por gramíneas de porte bajo (parches forrajeros), 5 parches dominados por gramíneas de porte intermedio (parches no forrajeros) y otros 5 por arbustos (parches arbustivos). A su vez mediante muestreos al azar se tomaron 5 muestras de suelo por parche, las que fueron extraídas por medio de un cilindro metálico de 7 cm de diámetro y 4 cm de profundidad, permitiendo dividir a la muestra en estratos: broza, 0-2 y 2-4 cm de profundidad. Los estratos se colocaron en bandejas de plástico sobre una cama de siembra esterilizada y se regaron periódicamente en invernáculo. Una vez germinadas las semillas se identificaron, contabilizaron y extrajeron las plántulas, reconociéndose para todas las profundidades 8 gramíneas. Luego de la quema Piptochaetium napostaense mostró un aumento en su germinación en 0-2 cm en los parches forrajeros y no forrajeros (P

Acoustic emission localization in beams based on time reversed dispersion

The common approach for the localization of acoustic emission sources in beams requires at least two measurements at different positions on the structure. The acoustic emission event is then located by evaluating the difference of the arrival times of the elastic waves. Here a new method is introduced, which allows the detection and localization of multiple acoustic emission sources with only a single, one point, unidirectional measurement. The method makes use of the time reversal principle and the dispersive behavior of the flexural wave mode. Whereas time-of-arrival (TOA) methods struggle with the distortion of elastic waves due to phase dispersion, the method presented uses the dispersive behavior of guided waves to locate the origin of the acoustic emission event. Therefore, the localization algorithm depends solely on the measured wave form and not on arrival time estimation. The method combines an acoustic emission experiment with a numerical simulation, in which the measured and time reversed displacement history is set as the boundary condition. In this paper, the method is described in detail and the feasibility is experimentally demonstrated by breaking pencil leads on aluminum beams and pultruded carbon fiber reinforced plastic beams according to ASTM E976 (Hsu-Nielsen source). It will be shown, that acoustic emissions are successfully localized even on anisotropic structures and in the case of geometrical complexities such as notches, which lead to reflections, and cross sectional changes, which affect the wave speed. The overall relative error in localizing the acoustic emission sources was found to be below 5%.

Instabilities in electromagnetic quasilevitation

We investigate free-surface instabilities occurring in various industrial processes involving liquid metal. Of particular interest is the behavior of the free surface of a pool of liquid metal when it is submitted to an alternating magnetic field. Experimentally, we study the effect of a vertical alternating medium-frequency magnetic field on an initially circular pool. We observe various types of behavior according to magnetic field amplitude, e.g., axisymmetric deformations, azimuthal mode structures, slow radial oscillation of the pool perimeter, and random rotation of the pool around its center. Drop rotation could be attributed to nonsymmetric shape deformations. The effect of oxidation leads to drastic changes in pool behavior. The experimental results are then compared to a linear stability analysis of the free surface of a circular liquid drop.

An anti-PCSK9 antibody reduces LDL-cholesterol on top of a statin and suppresses hepatocyte SREBP-regulated genes

Proprotein convertase subtilisin/kexin type 9 (PCSK9) is a promising therapeutic target for treating coronary heart disease. We report a novel antibody 1B20 that binds to PCSK9 with sub-nanomolar affinity and antagonizes PCSK9 function in-vitro. In CETP/LDLR-hemi mice two successive doses of 1B20, administered 14 days apart at 3 or 10 mpk, induced dose dependent reductions in LDL-cholesterol (≥ 25% for 7-14 days) that correlated well with the extent of PCSK9 occupancy by the antibody. In addition, 1B20 induces increases in total plasma antibody-bound PCSK9 levels and decreases in liver mRNA levels of SREBP-regulated genes PCSK9 and LDLR, with a time course that parallels decreases in plasma LDL-cholesterol (LDL-C). Consistent with this observation in mice, in statin-responsive human primary hepatocytes, 1B20 lowers PCSK9 and LDLR mRNA levels and raises serum steady-state levels of antibody-bound PCSK9. In addition, mRNA levels of several SREBP regulated genes involved in cholesterol and fatty-acid synthesis including ACSS2, FDPS, IDI1, MVD, HMGCR, and CYP51A1 were decreased significantly with antibody treatment of primary human hepatocytes. In rhesus monkeys, subcutaneous (SC) dosing of 1B20 dose-dependently induces robust LDL-C lowering (maximal ~70%), which is correlated with increases in target engagement and total antibody-bound PCSK9 levels. Importantly, a combination of 1B20 and Simvastatin in dyslipidemic rhesus monkeys reduced LDL-C more than either agent alone, consistent with a mechanism of action that predicts additive effects of anti-PCSK9 agents with statins. Our results suggest that antibodies targeting PCSK9 could provide patients powerful LDL lowering efficacy on top of statins, and lower cardiovascular risk.

The PlaNet Consortium: a network of European plant databases connecting plant genome data in an integrated biological knowledge resource

The completion of the Arabidopsis genome and the large collections of other plant sequences generated in recent years have sparked extensive functional genomics efforts. However, the utilization of this data is inefficient, as data sources are distributed and heterogeneous and efforts at data integration are lagging behind. PlaNet aims to overcome the limitations of individual efforts as well as the limitations of heterogeneous, independent data collections. PlaNet is a distributed effort among European bioinformatics groups and plant molecular biologists to establish a comprehensive integrated database in a collaborative network. Objectives are the implementation of infrastructure and data sources to capture plant genomic information into a comprehensive, integrated platform. This will facilitate the systematic exploration of Arabidopsis and other plants. New methods for data exchange, database integration and access are being developed to create a highly integrated, federated data resource for research. The connection between the individual resources is realized with BioMOBY. BioMOBY provides an architecture for the discovery and distribution of biological data through web services. While knowledge is centralized, data is maintained at its primary source without a need for warehousing. To standardize nomenclature and data representation, ontologies and generic data models are defined in interaction with the relevant communities.Minimal data models should make it simple to allow broad integration, while inheritance allows detail and depth to be added to more complex data objects without losing integration. To allow expert annotation and keep databases curated, local and remote annotation interfaces are provided. Easy and direct access to all data is key to the project.

A fully human monoclonal antibody to Staphylococcus aureus iron regulated surface determinant B (IsdB) with functional activity in vitro and in vivo

A fully human monoclonal antibody (CS-D7, IgG1) specific for the iron regulated surface determinant B (IsdB) of Staphylococcus aureus was isolated from the Cambridge Antibody Technology (CAT) scFv antibody library. As compared to previously described IsdB specific murine monoclonals, CS-D7 has a unique, non-overlapping binding site on IsdB, and exhibits increased in vivo activity. The antibody recognizes a conformational epitope spanning amino acids 50 to 285 and has a binding affinity of 340 (± 75) pM for IsdB. CS-D7 bound to a wide variety of S. aureus strains, but not to an isdB deletion mutant. The antibody mediated opsonophagocytic (OP) killing in vitro and mediated significant protection in vivo. In a murine lethal sepsis model, the antibody conferred protection from death when dosed prior to challenge, but not when dosed after challenge. Importantly, in a central venous catheter (CVC) model in rats, the antibody reduced bacteremia and prevented colonization of indwelling catheters. Protection was observed when rats were dosed with CS-D7 prior to challenge as well as post challenge. IsdB is currently being investigated for clinical efficacy against S. aureus infection, and the activity of this human IsdB specific antibody supplements the growing body of evidence to support targeting this antigen for vaccine development.

Generation and selection of novel fully human monoclonal antibodies that neutralize Dickkopf-1 (DKK1) inhibitory function in vitro and increase bone mass in vivo

Wnt/LRP5 signaling is a central regulatory component of bone formative and resorptive activities, and the pathway inhibitor DKK1 is a suppressor of bone formation and bone mass accrual in mice. In addition, augmented DKK1 levels are associated with high bone turnover in diverse low bone mass states in rodent models and disease etiologies in human. However, examination of the precise role of DKK1 in the normal skeleton and in higher species requires the development of refined DKK1-specific pharmacological tools. Here, we report the strategy resulting in isolation of a panel of fully human anti-DKK1 antibodies applicable to studies interrogating the roles of mouse, rhesus, and human DKK1. Selected anti-DKK1 antibodies bind primate and human DKK-1 with picomolar affinities yet do not appreciably bind to DKK2 or DKK4. Epitopes mapped within the DKK1 C-terminal domain necessary for interaction with LRP5/6 and consequently effectively neutralized DKK1 function in vitro. When introduced into naïve normal growing female mice, IgGs significantly improved trabecular bone volume and structure and increased both trabecular and cortical bone mineral densities in a dose-related fashion. Furthermore, fully human DKK1-IgG displayed favorable pharmacokinetic parameters in non-human primates. In summary, we demonstrate here a rate-limiting function of physiologic DKK1 levels in the regulation of bone mass in intact female mice, amendable to specific pharmacologic neutralization by newly identified DKK1-IgGs. Importantly the fully human IgGs display a profile of attributes that recommends their testing in higher species and their use in evaluating DKK1 function in relevant disease models.

Effects of local climate variability on transmission dynamics of cholera in Matlab, Bangladesh

Cholera is considered as a model for climate-related infectious diseases. In Bangladesh, cholera epidemics occur during summer and winter seasons, but it is not known how climate variability influences the seasonality of cholera. Therefore, the variability pattern of cholera events was studied in relation to the variation in local climate variables in Matlab, Bangladesh. Classification and regression tree (CART) and principal component analysis (PCA) were used to study the dependency and variability pattern of monthly total cholera cases. An average temperature <23.25 degrees C corresponded to the lowest average cholera occurrence (23 cases/month). At a temperature of >or=23.25 degrees C and sunshine <4.13h/day, the cholera occurrence was 39 cases/month. With increased sunshine (>or=4.13h/day) and temperature (23.25-28.66 degrees C), the second highest cholera occurrence (44 cases/month) was observed. When the sunshine was >or=4.13h/day and the temperature was >28.66 degrees C, the highest cholera occurrence (54 cases/month) was observed. These results demonstrate that in summer and winter seasons in Bangladesh, temperature and sunshine hours compensate each other for higher cholera incidence. The synergistic effect of temperature and sunshine hours provided the highest number of cholera cases.

The role of MR cholangiopancreatography in the evaluation of pregnant patients with acute pancreaticobiliary disease

This study aimed to determine the usefulness of MR cholangiopancreatography (MRCP) in the evaluation of pregnant patients with acute pancreaticobiliary disease and its additional value over ultrasound. MRI studies of pregnant patients who were referred because of acute pancreaticobiliary disease were included. MR images and patient charts were reviewed retrospectively to determine clinical outcome and the results of other imaging studies. 18 pregnant patients underwent MRCP because of right upper quadrant pain (n = 6), pancreatitis (n = 9), cholangitis (n = 1) or jaundice (n = 2). 15 patients were also evaluated with ultrasound. Biliary dilatation was detected in eight patients by ultrasound, but the cause of biliary dilatation could not be determined by ultrasound in seven patients. MRCP demonstrated the aetiology in four of these patients (choledocholithiasis (n = 1), Mirizzi syndrome (n = 1), choledochal cyst (n = 1) and intrahepatic biliary stones (n = 1)) and excluded obstructive pathology in the other four patients. MRCP was unremarkable in the seven patients who had no biliary dilatation on ultrasound. Three patients underwent only MRCP; two had choledocholithiasis and one cholelithiasis and pancreatitis. Choledocholithiasis diagnosed with MRCP (n = 3) was confirmed by endoscopic retrograde cholangiopancreatography. Mirizzi syndrome (n = 1) and a choledochal cyst (n = 1) were confirmed by surgery. The patients with normal MRCP (n = 12) and one patient with intrahepatic stones improved with medical treatment. MRCP appears to be a valuable and safe technique for the evaluation of pregnant patients with acute pancreaticobiliary disease. Especially when ultrasound shows biliary dilatation, MRCP can determine the aetiology and save the patient from unnecessary endoscopic retrograde cholangiopancreatography by excluding a biliary pathology.

Familial leiomyomatosis: a review and discussion of pathogenesis

Multiple cutaneous leiomyomas of pilar origin have long been recognized to have an autosomal dominant inheritance. While the skin tumors are relatively uncommon and benign, women of affected families often develop uterine fibroids with associated infertility, pain and bleeding. In addition, a subset of these families harbors a predisposition to papillary renal cell carcinoma. Germline mutations in a recently identified classical tumor suppressor gene encoding fumarate hydratase are observed in these individuals. Appropriate screening measures for associated disorders are mandatory.

The power law distribution for walking-time intervals correlates with the ellipsoid-body in Drosophila

The temporal properties of a variety of behavioral traits obey power law distributions, a property often referred to as fractal. We recently showed that the temporal pattern of locomotor activity of the fruitfly Drosophila melanogaster follows this distribution. Although an increasing number of such fractal patterns are being discovered, the brain areas and neuronal networks responsible remain unknown. In this study, we show that specifically blocking synapses established by neurons of the Drosophila ellipsoid-body, a substructure of the central complex in the brain, leads to a loss of the fractal properties in the temporal pattern. We conclude that the temporal fractal pattern of locomotor activity is regulated in the ellipsoid-body.

Wind-induced ventilation of the giant nests of the leaf-cutting ant Atta vollenweideri

To understand the significance of elaborate nest architecture for the control of nest climate, we investigated the mechanisms governing nest ventilation in a large field nest of Atta vollenweideri. Surface wind, drawing air from the central tunnels of the nest mound, was observed to be the main driving force for nest ventilation during summer. This mechanism of wind-induced ventilation has so far not been described for social insect colonies. Thermal convection, another possible force driving ventilation, contributed very little. According to their predominant airflow direction, two functionally distinct tunnel groups were identified: outflow tunnels in the upper, central region, and inflow tunnels in the lower, peripheral region of the nest mound. The function of the tunnels was independent of wind direction. Outflow of air through the central tunnels was followed by a delayed inflow through the peripheral tunnels. Leaf-cutting ants design the tunnel openings on the top of the nest with turrets which may reinforce wind-induced nest ventilation.

Combining speech recognition software with Digital Imaging and Communications in Medicine (DICOM) workstation software on a Microsoft Windows platform

This presentation describes our experience in combining speech recognition software, clinical review software, and other software products on a single computer. Different processor speeds, random access memory (RAM), and computer costs were evaluated. We found that combining continuous speech recognition software with Digital Imaging and Communications in Medicine (DICOM) workstation software on the same platform is feasible and can lead to substantial savings of hardware cost. This combination optimizes use of limited workspace and can improve radiology workflow.

Combined intravenous and intra-arterial recombinant tissue plasminogen activator in acute ischemic stroke

BACKGROUND AND PURPOSE

A retrospective analysis was performed on 20 consecutive patients who presented with severe acute ischemic stroke and were evaluated for a combined intravenous (IV) and local intra-arterial (IA) recombinant tissue plasminogen activator (rtPA) thrombolytic approach within 3 hours of onset.

METHODS

Twenty consecutive patients with carotid artery distribution strokes were evaluated and treated using a combined IV and IA rtPA approach over a 14-month period (September 1998 to October 1999). rtPA (0.6 mg/kg) was given intravenously (maximum dose 60 mg); 15% of the IV dose was given as bolus, followed by a continuous infusion over 30 minutes. A maximal IA dose, up to 0.3 mg/kg or 24 mg, whichever was less, was given over a maximum of 2 hours. IV treatment was initiated within 3 hours in 19 of 20 patients. All 20 patients underwent angiography, and 16 of 20 patients received local IA rtPA.

RESULTS

The median baseline National Institutes of Health Stroke Scale (NIHSS) score for the 20 patients was 21 (range 11 to 31). The median time from stroke onset to IV treatment was 2 hours and 2 minutes, and median time to initiation of IA treatment was 3 hours and 30 minutes. Ten patients (50%) recovered to a modified Rankin Scale (mRS) of 0 or 1; 3 patients (15%), to an mRS of 2; and 5 patients (25%), to an mRS of 4 or 5. One patient (5%) developed a symptomatic intracerebral hemorrhage and eventually died. One other patient (5%) expired because of complications from the stroke.

CONCLUSIONS

We believe that the greater-than-expected proportion of favorable outcomes in these patients with severe ischemic stroke reflects the short time to initiation of both IV and IA thrombolysis.

Defective pigment granule biogenesis and aberrant behavior caused by mutations in the Drosophila AP-3beta adaptin gene ruby

Lysosomal protein trafficking is a fundamental process conserved from yeast to humans. This conservation extends to lysosome-like organelles such as mammalian melanosomes and insect eye pigment granules. Recently, eye and coat color mutations in mouse (mocha and pearl) and Drosophila (garnet and carmine) were shown to affect subunits of the heterotetrameric adaptor protein complex AP-3 involved in vesicle trafficking. Here we demonstrate that the Drosophila eye color mutant ruby is defective in the AP-3beta subunit gene. ruby expression was found in retinal pigment and photoreceptor cells and in the developing central nervous system. ruby mutations lead to a decreased number and altered size of pigment granules in various cell types in and adjacent to the retina. Humans with lesions in the related AP-3betaA gene suffer from Hermansky-Pudlak syndrome, which is caused by defects in a number of lysosome-related organelles. Hermansky-Pudlak patients have a reduced skin pigmentation and suffer from internal bleeding, pulmonary fibrosis, and visual system malfunction. The Drosophila AP-3beta adaptin also appears to be involved in processes other than eye pigment granule biogenesis because all ruby allele combinations tested exhibited defective behavior in a visual fixation paradigm.

[An instrument for evaluating the psychiatric personnel regulation]

Since 1991, the Psychiatrie-Personalverordnung (Psych-PV) regulates the allocation of personnel in German psychiatric hospitals and psychiatric wards. Psych-PV defines the personnel's diagnostic and therapeutic tasks based on an illness severity scale. A group of experts from the Medical Advisory Services of Social Security--Health Insurance (MDK) has developed a questionnaire as an instrument to systematically gather, from a given hospital, structural data relevant for application of Psych-PV. The questionnaire consists of two parts, relating to the hospital and to the individual wards. The hospital supplies information such as statutory catchment area, types of care offered, capacity, personnel, organisational structure, patients' diagnoses, and co-operation with complementary institutions. The section pertaining to individual wards collects data on admission and discharge, duration of treatment, re-admissions, and internal transfer. The distribution of the severity of patients' illnesses within individual wards, which has been defined in the budget, is the basis for a review of the actual number of staff as well as of the realization of basic tasks of diagnostics and treatment. Questions pertaining to treatment concepts in individual wards are aimed to ascertain the degree of agreement with the conceptual goals of Psych-PV. The methods of treatment offered in a given ward can be gleaned from its weekly organisation-plan. Indications for the realization of basic tasks of diagnostics and treatment can be derived from the information supplied by each personnel group of a ward with regard to specific tasks of individual and group treatment. The questionnaire developed by the MDK in Hessen allows to review the extent to which the allocation of staff according to Psych-PV on the level of the individual ward translates into appropriate treatment options. The questionnaire also offers a basis for a comparison of hospitals.

Stringent tests of shell model calculations in fp shell nuclei (46, 48)Ti and (50,52)Cr from measurements of g factors and B(E2) values

Measurements of magnetic moments and lifetimes of 2(+)(1) and 4(+)(1) states of (46,48)Ti and (50,52)Cr were performed with high accuracy via projectile Coulomb excitation and the technique of transient magnetic fields. The high quality of the data allows for the first time to establish stringent constraints on large scale shell model calculations. Whereas the global behavior of the data is well explained by full fp shell model calculations, distinct deviations in the g factors and B(E2) values of (46,48)Ti from theoretical predictions can be attributed to excitations of the 40Ca core. This suggestion is supported by recent Monte Carlo calculations which provide evidence that 48Ca is a better inert core.

The memory template in Drosophila pattern vision at the flight simulator

Pattern recognition is studied in flight orientation of fixed flying Drosophila melanogaster controlling the horizontal rotations of an arena. Earlier experiments had suggested a simple mechanism of pattern recognition in which a memory template and the actual image are retinotopically matched. In contrast, we now show that Drosophila extracts at least two and probably four pattern parameters: size, vertical position of the center of gravity and, presumably horizontal/vertical extent as well as vertical separatedness of pattern elements. Moreover, the fly treats isolated pattern elements as a compound figure. Retinal transfer is possible between training and test if the centers of gravity of the compound figures are retained.

Flexible sigmoidoscopy by nurses: state of the art 1999

Although screening flexible sigmoidoscopy is associated with a significant decrease in colorectal cancer mortality, less than 50% of eligible Americans have had a sigmoidoscopy. As the United States population ages, over 50 million Americans will be eligible for colorectal cancer screening with flexible sigmoidoscopy. The projected increase in a population eligible for screening is expected to increase demand for this procedure and may result in overwhelming currently available endoscopic resources. Gastroenterology nurses should actively seek training to perform flexible sigmoidoscopy to accommodate this increased demand. Current barriers to nurse-performed sigmoidoscopy are prohibitions by state Boards of Nursing and lack of procedural reimbursement for nurse endoscopists performing flexible sigmoidoscopy. The lack of research about the effectiveness of this practice is a contributing factor to the hindrances in the development of this nursing role. This review outlines research about the effectiveness of flexible sigmoidoscopy by nurses, legal and reimbursement issues, and details the scope of training programs used by institutions with nurse endoscopists.

Three cases of dural arteriovenous fistula of the anterior condylar vein within the hypoglossal canal

Dural arteriovenous fistulas (DAVFs) of the anterior condylar vein are an uncommon but important subset of fistulas occurring at the skull base that can be confused with DAVFs of the marginal sinus on angiography. MR angiography source images can document the intraosseous extent and the relationship to the hypoglossal canal of this type of fistula, which can have significant clinical implications. We present the imaging features of angiography, CT, and MR angiography of three cases of DAVFs localized to the anterior condylar vein and within the hypoglossal canal, which were confirmed by source images from MR angiography. Transvenous coil embolization was curative in two of three cases and would seem to be the treatment of choice when venous access is available.

Context generalization in Drosophila visual learning requires the mushroom bodies

The world is permanently changing. Laboratory experiments on learning and memory normally minimize this feature of reality, keeping all conditions except the conditioned and unconditioned stimuli as constant as possible. In the real world, however, animals need to extract from the universe of sensory signals the actual predictors of salient events by separating them from non-predictive stimuli (context). In principle, this can be achieved if only those sensory inputs that resemble the reinforcer in their temporal structure are taken as predictors. Here we study visual learning in the fly Drosophila melanogaster, using a flight simulator, and show that memory retrieval is, indeed, partially context-independent. Moreover, we show that the mushroom bodies, which are required for olfactory but not visual or tactile learning, effectively support context generalization. In visual learning in Drosophila, it appears that a facilitating effect of context cues for memory retrieval is the default state, whereas making recall context-independent requires additional processing.

Efficacy of disinfection of shell eggs externally contaminated with Salmonella enteritidis. Implications for egg testing

Experimental contamination of the surface of shell eggs by dipping in a culture of Salmonella enteritidis resulted in the presence of Salmonella enteritidis in/on the shells as well as shell membranes but not in the egg content. Disinfection with Lugol's solution, chlorhexidine, ethanol, quarternary ammonium solutions or flaming after dipping in ethanol failed to achieve complete decontamination of the shell and membranes with resulting false positives when eggs were broken for culturing of the content. Dipping eggs for three seconds in boiling water resulted in complete destruction of Salmonella enteritidis in shells and membranes but sometimes caused the eggs to crack. A method of aseptically opening eggs without risk of contaminating the content from the shell or membrane was developed. Salmonella enteritidis deposited in/on the shell and membranes did not multiply during storage of the eggs at 20 degrees C for four weeks, the counts seemed to decrease. No Salmonella enteritidis was detected in the contents of any contaminated eggs.

Multiple mechanisms are involved in the acute vasodilatory effect of 17beta-estradiol in the isolated perfused rat heart

The purpose of this study was to define the dose-dependent effects of 17beta-estradiol on coronary flow and cardiac function in isolated rat hearts and to identify the mechanisms involved in its vasodilator action. Hearts from female and male Wistar rats were perfused at constant pressure (100 mm Hg). Stereoisomer specificity and the mechanism of vasodilation by 17beta-estradiol were examined in female rat hearts. Function was measured by a left ventricular (LV) balloon and coronary flow (CF) with an ultrasonic flowmeter. 17Beta-estradiol at 10(-6), 5 x 10(-6), and 10(-5) M increased CF in female hearts by 5 +/- 2, 27 +/- 4 (p < 0.05 vs. baseline), and 40 +/- 4% (p < 0.05 vs. baseline), respectively. The effect of 17beta-estradiol in hearts from male rats was similar but less pronounced compared with females [deltaCF 8 +/- 3, 19 +/- 3 (p < 0.05 vs. baseline)] and 25 +/- 7% (p < 0.05 vs. baseline; p < 0.05 vs. female 17beta-estradiol). Maximum vasodilation by the stereoisomer 17alpha-estradiol was significantly smaller [deltaCF 5 +/- 3, 4 +/- 3 (p < 0.05 vs. female 17beta-estradiol) and 14 +/- 1% (p < 0.05 vs. baseline; p < 0.05 vs. female 17beta-estradiol)] for 10(-6), 5 x 10(-6), and 10(-5) M. Pretreatment with the NO-synthesis inhibitor Nomega-methyl-L-arginine (10(-4) M) had no effect on the maximal vasodilator response to 17beta-estradiol (10(-5) M) [deltaCF 36 +/- 6% (p < 0.05 vs. baseline)]. When hearts were pretreated with the prostaglandin-synthesis inhibitor diclofenac (10(-6) M), the maximal vasodilator effect of 17beta-estradiol was partially attenuated [deltaCF 12 +/- 7% (p < 0.05 vs. female 17beta-estradiol)]. Similarly, pretreatment with the K+ATP-blocker glibenclamide (10(-6) M) partially inhibited the maximal vasodilator effect of 17beta-estradiol [deltaCF 22 +/- 6% (p < 0.05 vs. baseline; p < 0.05 vs. female 17beta-estradiol)]. Pretreatment with the Ca2+ channel antagonist nifedipine (7.2 x 10(-8) M) completely blocked the vasodilator effect. In isolated perfused rat hearts, 17beta-estradiol induced marked acute coronary vasodilation; this effect is in part gender specific, and in female hearts, largely stereoisomer specific. The dilator effect is mediated predominantly by calcium channel blockade, but prostaglandin release and K+ATP channel activation also are involved. In the isolated perfused rat heart, NO production does not contribute to the acute vasodilator effect of 17beta-estradiol.

A desktop digital imaging and communications in medicine picture archiving and communications system with multiple monitors using Windows '98

Combining DICOM software and internet access using desktops, an accessible and low-cost PACS system is conveniently available to the medical community.

[Cooperation and job satisfaction in a nursing-physician team. An analysis of nursing evaluation in psychiatry]

PURPOSE

Empirical studies of nursing in psychiatry rarely consider the collaboration between nurses and doctors. Which variables determine the quality of the cooperation between nurses and doctors?

METHODS

In 1992 and 1997, all nurses of a psychiatric hospital were interrogated by means of questionnaire (FAPP) in order to measure the quality of collaboration.

RESULTS

In spite of major changes in the hospital management and higher work-load assessment by the nurses concerning the collaboration with doctors and with other nurses, the quality of team-work and participating in treatment decisions, was more positive in 1997. Nurses with a "negative" collaboration with doctors, also have difficulties to collaborate with other nurses. This finding did not depend on gender, age or length of professional career.

CONCLUSION

All institutional provisions that improve the cooperation, the competence, the responsibility, and the ward-atmosphere, also ameliorate the cooperation with other occupational groups in the hospital.

A picture archiving and communications system featuring multiple monitors using Windows98

We present an effective approach to manage, review, and distribute Digital Imaging and Communications in Medicine (DICOM) images with multiple monitors using Windows98 (Microsoft Corp, Redmond, WA) that can be implemented in an office-based setting. Computed tomography (CT), magnetic resonance imaging (MRI), and angiographic DICOM images were collected, compressed, and stored using Medweb (Medweb, Inc, San Francisco, CA) software. The Medweb server used the Linux/UNIX operating system on a Pentium 333-MHz processor with 128 MB of RAM. Short-term storage capacity was about 2 weeks with routine usage of an 11-GB hard drive. Images were presented for reading on a dual-monitor Windows98 Pentium display station with 160 MB of RAM using a Medweb/Netscape (Netscape Communications Corp, Mountain View, CA) viewer. There was no significant discrepancy in diagnosis between electronic and conventional film images. Mean reading time for 32 cases was 118 seconds. The Medweb JAVA plug-in viewer loaded the first image within 30 seconds of selecting the case for review. Full uncompressed 16-bit images allowed different window settings to better assess for pathology. Multiple monitors allowed viewing various hanging protocols. Cine viewing was also possible. Key diagnostic images were electronically transmitted to referring physicians. On-call radiologists were able to access images through the Internet. By combining Medweb, DICOM, and web-browser software using desktop personal computers (PCs), an easily accessible picture archiving and communications system (PACS) is available to radiologists and referring physicians. Multiple monitors are easily configured and managed using Windows98. This system can sustain changes and can be extended to provide variable functions using inexpensive PCs.

[Dimensions of work stress and job satisfaction in psychiatric-psychotherapeutic practice]

Empirical studies of nursing in psychiatry and psychosomatics rarely consider the dialectics between work load and positive aspects of social support. Resulting from theoretical considerations and practical experiences seven dimensions were defined that might influence overall job satisfactions and stress. To measure this, a questionnaire containing 53 items was developed. This instrument was answered by 134 nurses of a psychiatric hospital. The results show that factor analysis and item analysis only partly confirm the presumptions. The five empirical scales include "stress due to work conditions and patients", "collaboration in teamwork", "collaboration with physicians and therapists", "collaboration with superiors in nursing" and "responsibility, competence and decision-making". Theoretical dimensions and empirical scales are discussed. The high work stress caused by work conditions and difficult patients is compensated by a positive evaluation of the collaboration in the nursing-team with physicians and therapists as well as with superiors.

Temporal pattern of locomotor activity in Drosophila melanogaster

The temporal pattern of locomotor activity of single Drosophila melanogaster flies freely walking in small tubes is described. Locomotor activity monitored by a light gate has a characteristic time-course that depends upon age and the environmental conditions. Several methods are applied to assess the complexity of the temporal pattern. The pattern varies according to sex, genotype, age and environmental conditions (food; light). Activity occurs clustered in bouts. The intrinsic bout structure is quantified by four parameters: number of light gate passages (counts) per bout, duration of a bout, pause between two successive bouts and mean bout period. In addition, the distribution of the periods between light-gate crossings (inter-count intervals) as function of inter-count interval duration reveals a power law, suggesting that the overall distribution of episodes of activity and inactivity has a fractal structure. In the dark without food, the fractal dimension which represents a measure of the complexity of the pattern is sex, genotype and age specific. Fractality is abolished by additional sensory stimulation (food; light). We propose that time-course, bout structure and fractal dimension of the temporal pattern of locomotor activity describe different aspects of the fly's central pattern generator for locomotion and its motivational control.

The virtual lecture: delivery of live and recorded presentations over the Internet

OBJECTIVE

Our objective was to deliver live and recorded lectures, with images, over the Internet using streaming media.

CONCLUSION

Streaming media are an emerging technology that can deliver live lectures over the Internet using standard PCs and modems. These lectures are also simultaneously recorded and can be played back at any time by individuals with access to the Web.

Mushroom bodies suppress locomotor activity in Drosophila melanogaster

Locomotor activity of single, freely walking flies in small tubes is analyzed in the time domain of several hours. To assess the influence of the mushroom bodies on walking activity, three independent noninvasive methods interfering with mushroom body function are applied: chemical ablation of the mushroom body precursor cells; a mutant affecting Kenyon cell differentiation (mushroom body miniature); and the targeted expression of the catalytic subunit of tetanus toxin in subsets of Kenyon cells. All groups of flies with mushroom body defects show an elevated level of total walking activity. This increase is attributable to the slower and less complete attenuation of activity during the experiment. Walking activity in normal and mushroom body-deficient flies is clustered in active phases (bouts) and rest periods (pauses). Neither the initiation nor the internal structure, but solely the termination of bouts seems to be affected by the mushroom body defects. How this finding relates to the well-documented role of the mushroom bodies in olfactory learning and memory remains to be understood.