Mind over motor mapping: Driver response to changing vehicle dynamics.

Improvements in vehicle safety require understanding of the neural systems that support the complex, dynamic task of real-world driving. We used functional near infrared spectroscopy (fNIRS) and pupilometry to quantify cortical and physiological responses during a realistic, simulated driving task in which vehicle dynamics were manipulated. Our results elucidate compensatory changes in driver behavior in response to changes in vehicle handling. We also describe associated neural and physiological responses under different levels of mental workload. The increased cortical activation we observed during the late phase of the experiment may indicate motor learning in prefrontal-parietal networks. Finally, relationships among cortical activation, steering control, and individual personality traits suggest that individual brain states and traits may be useful in predicting a driver's response to changes in vehicle dynamics. Results such as these will be useful for informing the design of automated safety systems that facilitate safe and supportive driver-car communication.

Generation and evaluation of a monoclonal antibody, designated MAdL, as a new specific marker for adenocarcinomas of the lung.

BACKGROUND: Different therapy regimens in non-small-cell lung cancer (NSCLC) are of rising clinical importance, and therefore a clear-cut subdifferentiation is mandatory. The common immunohistochemical markers available today are well applicable for subdifferentiation, but a fraction of indistinct cases still remains, demanding upgrades of the panel by new markers. METHODS: We report here the generation and evaluation of a new monoclonal antibody carrying the MAdL designation, which was raised against primary isolated human alveolar epithelial cells type 2. RESULTS: Upon screening, one clone (MAdL) was identified as a marker for alveolar epithelial cell type II, alveolar macrophages and adenocarcinomas of the lung. In a large-scale study, this antibody, with an optimised staining procedure for formalin-fixed tissues, was then evaluated together with the established markers thyroid transcription factor-1, surfactant protein-A, pro-surfactant protein-B and napsin A in a series of 362 lung cancer specimens. The MAdL displays a high specificity (>99%) for adenocarcinomas of the lung, together with a sensitivity of 76.5%, and is capable of delivering independent additional diagnostic information to the established markers. CONCLUSION: We conclude that MAdL is a new specific marker for adenocarcinomas of the lung, which helps to clarify subdifferentiation in a considerable portion of NSCLCs.

Human vascular smooth muscle cells express interleukin-1beta-converting enzyme (ICE), but inhibit processing of the interleukin-1beta precursor by ICE.

Local immunoregulatory processes during normal vascular biology or pathogenesis are mediated in part by the production of and response to cytokines by vessel wall cells. Among these cytokines interleukin (IL)-1 is considered to be of major importance. Although vascular smooth muscle (SMC) and endothelial cells (EC) expressed both IL-1alpha and IL-1beta as cell-associated, 33-kilodalton (kD) precursors, SMC neither contained detectable mature IL-1beta, nor processed recombinant IL-1beta precursor into its mature 17-kD form. Thus, we investigated the expression and function of IL-1beta-converting enzyme (ICE) in vascular cells. We demonstrate in processing experiments with recombinant IL-1 precursor molecules that EC processed IL-1beta, in contrast to SMC. Despite the failure of SMC to process IL-1beta, these cells expressed ICE mRNA, immunoreactive ICE protein, and the expected IL-1beta nucleotide sequence. The lack of processing was explained by our finding that extracts of SMC specifically and concentration dependently blocked processing of IL-1beta precursor by recombinant or native ICE. The initial biochemical characterization of the inhibitory activity showed that it is heat-labile, has a molecular size of 50-100 kD, and is associated to the cell membrane compartment. Inhibition of processing, i.e., activation of IL-1beta precursor by SMC may constitute a novel regulatory mechanism during normal vascular biology or pathogenesis of vascular diseases.

The cell proliferation-associated antigen of antibody Ki-67: a very large, ubiquitous nuclear protein with numerous repeated elements, representing a new kind of cell cycle-maintaining proteins.

The antigen defined by mAb Ki-67 is a human nuclear protein the expression of which is strictly associated with cell proliferation and which is widely used in routine pathology as a "proliferation marker" to measure the growth fraction of cells in human tumors. Ki-67 detects a double band with apparent molecular weights of 395 and 345 kD in immunoblots of proteins from proliferating cells. We cloned and sequenced the full length cDNA, identified two differentially spliced isoforms of mRNA with open reading frames of 9,768 and 8,688 bp encoding for this cell proliferation-associated protein with calculated molecular weights of 358,761 D and 319,508 D, respectively. New mAbs against a bacterially expressed part and a synthetic polypeptide deduced from the isolated cDNA react with the native Ki-67 antigen, thus providing a circle of evidence that we have cloned the authentic Ki-67 antigen cDNA. The central part of the Ki-67 antigen cDNA contains a large 6,845-bp exon with 16 tandemly repeated 366-bp elements, the "Ki-67 repeats", each including a highly conserved new motif of 66 bp, the "Ki-67 motif", which encodes for the epitope detected by Ki-67. Computer analysis of the nucleic acid and the deduced amino acid sequence of the Ki-67 antigen confirmed that the cDNA encodes for a nuclear and short-lived protein without any significant homology to known sequences. Ki-67 antigen-specific antisense oligonucleotides inhibit the proliferation of IM-9 cell line cells, indicating that the Ki-67 antigen may be an absolute requirement for maintaining cell proliferation. We conclude that the Ki-67 antigen defines a new category of cell cycle-associated nuclear nonhistone proteins.

Two coronaviruses isolated from central nervous system tissue of two multiple sclerosis patients.

Two coronaviruses were isolated from brain material obtained at autopsy from two multiple sclerosis patients. The viruses were neutralized by serum and spinal fluid from these patients. Although most of the population have antibody to these virus isolates, multiple sclerosis patients have slightly higher concentrations of serum antibody than controls. The results suggest that coronaviruses should be considered as one additional virus with a potential implication in the etiology of multiple sclerosis.

Neural network vehicle models for high-performance automated driving.

Automated vehicles navigate through their environment by first planning and subsequently following a safe trajectory. To prove safer than human beings, they must ultimately perform these tasks as well or better than human drivers across a broad range of conditions and in critical situations. We show that a feedforward-feedback control structure incorporating a simple physics-based model can be used to track a path up to the friction limits of the vehicle with performance comparable with a champion amateur race car driver. The key is having the appropriate model. Although physics-based models are useful in their transparency and intuition, they require explicit characterization around a single operating point and fail to make use of the wealth of vehicle data generated by autonomous vehicles. To circumvent these limitations, we propose a neural network structure using a sequence of past states and inputs motivated by the physical model. The neural network achieved better performance than the physical model when implemented in the same feedforward-feedback control architecture on an experimental vehicle. More notably, when trained on a combination of data from dry roads and snow, the model was able to make appropriate predictions for the road surface on which the vehicle was traveling without the need for explicit road friction estimation. These findings suggest that the network structure merits further investigation as the basis for model-based control of automated vehicles over their full operating range.

Chromophore-assisted light inactivation of pKi-67 leads to inhibition of ribosomal RNA synthesis.

OBJECTIVES: Expression of the nuclear Ki-67 protein (pKi-67) is strongly associated with cell proliferation. For this reason, antibodies against this protein are widely used as prognostic tools for the assessment of cell proliferation in biopsies from cancer patients. Despite this broad application in histopathology, functional evidence for the physiological role of pKi-67 is still missing. Recently, we proposed a function of pKi-67 in the early steps of ribosomal RNA (rRNA) synthesis. Here, we have examined the involvement of pKi-67 in this process by photochemical inhibition using chromophore-assisted light inactivation (CALI). MATERIALS AND METHODS: Anti-pKi-67 antibodies were labelled with the fluorochrome fluorescein 5(6)-isothiocyanate and were irradiated after binding to their target protein. RESULTS: Performing CALI in vitro on cell lysates led to specific cross-linking of pKi-67. Moreover, the upstream binding factor (UBF) necessary for rRNA transcription was also partly subjected to cross-link formation, indicating a close spatial proximity of UBF and pKi-67. CALI in living cells, using micro-injected antibody, caused a striking relocalization of UBF from foci within the nucleoli to spots located at the nucleolar rim or within the nucleoplasm. pKi-67-CALI resulted in dramatic inhibition of RNA polymerase I-dependent nucleolar rRNA synthesis, whereas RNA polymerase II-dependent nucleoplasmic RNA synthesis remained almost unaltered. CONCLUSIONS: Our data presented here argue for a crucial role of pKi-67 in RNA polymerase I-dependent nucleolar rRNA synthesis.

Novel type of proliferating lymphoplasmacytoid cell with a characteristic spotted immunofluorescence pattern.

We examined bone marrow from myeloma patients for the presence of cells with the characteristics of the clonogenic cell in the myeloma stem cell assay. We identified a novel type of cell that contained cytoplasmic immunoglobulin of the relevant idiotype located in a cytoplasmic spot. This "spotted" Ig could be located in the rough endoplasmic reticulum. Spotted cells are highly proliferative, as evidenced by the nuclear staining with the antibody Ki67, and were found in the bone marrow from most of the myeloma patients studied. This type of cell was also present in patients with immunocytomas, in some cases of benign monoclonal gammopathy, and in patients in the state of polyclonal hypergammaglobulinemia. IgG subclass distribution of so-called spotted cells and plasma cells, found in a patient with pseudo biclonal gammopathy, indicates that spotted cells are intermediate between B cells and plasma cells. Spotted cells express the B cell-associated antigens HB4 and HB6 but do not express other B cluster of differentiation antigens or plasmacytoid antigens tested.

Neural, physiological, and behavioral correlates of visuomotor cognitive load.

Visuomotor ability is quite crucial for everyday functioning, particularly in driving and sports. While there is accumulating evidence regarding neural correlates of visuomotor transformation, less is known about the brain regions that accommodate visuomotor mapping under different cognitive demands. We concurrently measured cortical activity and pupillary response, using functional near infrared spectroscopy (fNIRS) and eye-tracking glasses, to examine the neural systems linked to pupil dilation under varying cognitive demands. Twenty-three healthy adults performed two sessions of a navigation task, in which the cognitive load was manipulated by either reversing the visuomotor mapping or increasing the speed of the moving object. We identified a region in the right superior parietal lobule that responded to both types of visuomotor load and its activity was associated with larger pupillary response and better performance in the task. Our multimodal analyses suggest that activity in this region arises from the need for increased attentional effort and alertness for visuomotor control and is an ideal candidate for objective measurement of visuomotor cognitive load. Our data extend previous findings connecting changes in pupil diameter to neural activity under varying cognitive demand and have important implications for examining brain-behavior associations in real-world tasks such as driving and sports.

Relationship of cytosolic estrogen and progesterone receptor content and the growth fraction in human mammary carcinomas.

In this study of breast cancer specimens, the relationship between cytosolic estrogen (ER) and progesterone receptor (PR) content to the size of the respective growth fraction (GF) (expressed as percentage of proliferating tumor cells) was investigated. We applied the recently developed ligand-binding assay for extracts of frozen sections and Ki-67 immunocytochemistry for the assessment of the GF to adjoining serial sections of a single tissue block. If the receptor content is plotted against the percentage of Ki-67 labeled cells, an inverse relationship between receptor content and proliferation becomes obvious, meaning that a high receptor content is associated with a small GF and vice versa. If tumor specimens are grouped according to the evaluated receptor status, the mean percentage of Ki-67-positive cells is 12% for ER-positive/PR-positive (ER+/PR+), 26% for ER-positive/PR-negative (ER+/PR-), 55% for ER-negative/PR-positive (ER-/PR+), and 57% for ER-negative/PR-negative (ER-/PR-) specimens. A significant population of tumors exists, however, which exhibit a high receptor content and a high GF. The percentages of ER+/PR+ samples with a high proliferation index are 16 and 26% if the total ER+ population is considered.

Motor learning affects car-to-driver handover in automated vehicles.

Vehicles in the foreseeable future will be required to transition between autonomous driving (without human involvement) and full human control. During this transition period, the human, who has not been actively engaged in the driving process, must resume the motor control necessary to steer the car. The in-car study presented here demonstrates that when human drivers are presented with a steering behavior that is different from the last time they were in control, specifically the ratio of hand wheel angle to road wheel angle (emulating a change in vehicle speed), they undergo a significant period of adaptation before they return to their previous steering behavior. However, drivers do not require an adaptation period to return to previous driving behavior after changes in steering torque. These findings have implications for the design of vehicles that transition from automated to manual driving and for understanding of human motor control in real-world tasks.

Nuclear and cytoplasmic distribution of cellular myb protein in human haematopoietic cells evidenced by monoclonal antibody.

A monoclonal antibody was used for analysing the expression of the cellular myb (c-myb) protein in a variety of established human tumor cell lines and its decrease after induction of differentiation. Differentiated resting human T-cells and B-cells do not express detectable amounts of c-myb protein. However, upon mitogenic stimulation in vitro T-cells exhibit strong expression of the c-myb protein as demonstrated by immunocytochemical staining and indirect immunoprecipitation. In contrast to the transformed T-lymphoblastic cell line Molt-4, where c-myb protein is a nuclear antigen, it was found in proliferating normal T-cells almost exclusively distributed in the cytoplasm. Screening of a total of 70 fresh human malignant lymphomas by immunohistochemical staining indicates the presence of the c-myb protein primarily in non-Hodgkin's lymphomas with a large growth fraction, i.e. precursor cell-derived lymphoblastic lymphomas of B-cell type and T-cell type (9/10, 3/4, respectively) and anaplastic large cell Ki-1 lymphomas (5/9), which originate from activated lymphoid cells. The c-myb protein was located predominantly in the nucleus and in some cases additionally in the cytoplasm. The different subcellular locations suggest a dual functional role. While nuclear localisation is exhibited by transformed haematopoietic cells, cytoplasmic localisation appears to be characteristic for proliferating normal T-cells and points to a second property of the c-myb protein other than interaction with DNA.

Decreased fibronectin biosynthesis by human cord blood mononuclear phagocytes in vitro.

Cultured cord blood monocytes synthesize significantly less fibronectin than cultured monocyte-macrophages from adult peripheral blood. Biosynthesis of the second component of complement in vitro is similar for both cell systems. The monocyte-macrophages from neonates and adults have similar functional and morphologic properties in long-term cultures. The decreased monocyte-macrophage biosynthesis of fibronectin observed in vitro may be in part related to the reduced plasma fibronectin concentrations and reticuloendothelial system hypofunction which occur in newborn infants.

Fibronectin and complement secretion by monocytes and peritoneal macrophages in vitro from patients undergoing continuous ambulatory peritoneal dialysis.

We investigated the role of the opsonic glycoprotein fibronectin in the host defense of the peritoneum in patients undergoing continuous ambulatory peritoneal dialysis (CAPD). Fibronectin concentration in peritoneal dialysate from high infection rate CAPD patients (greater than 1.50 episodes peritonitis per year) was significantly less than from low infection rate CAPD patients (less than 0.55 episodes peritonitis per year). In vitro secretion of fibronectin by cultured peritoneal macrophages from patients with high infection rate was less than from low infection rate patients (P less than 0.05) and controls (P less than 0.01). In vitro secretion of the second component of complement, however, was similar in both high and low infection rate patients. Plasma fibronectin concentration and in vitro fibronectin secretion by cultured peripheral blood monocytes was not different between high infection rate patients and low infection rate patients, but was less than normals. Decreased fibronectin secretion by peritoneal macrophages is associated with a higher incidence of peritonitis among CAPD patients.

Molecular characterization of the gene locus of the human cell proliferation-associated nuclear protein defined by monoclonal antibody Ki-67.

The human antigen defined by the monoclonal antibody Ki-67, the 'Ki-67 protein', is an ubiquitously expressed human nuclear protein strictly associated with cell proliferation and is widely used in routine pathology as a 'proliferation marker' to measure the growth fraction in human tumours. In immunoblots of proteins from proliferating cells, Ki-67 detects two bands with the apparent molecular weights of 345 and 395 kDa. Recently we reported on the cloning and sequencing of the complete cDNA of the Ki-67 protein. We found two isoforms of cDNA with full lengths of 11.4 and 12.5 kb, respectively, likely formed by the alternative splicing of exon 7. The remarkable exon 13 at the 'centre' of this gene contains 16 homologous segments of 366 bp (Ki-67 repeats), each including a highly conserved new motif of 66 bp (Ki-67 motif). Computer analyses confirmed that the cDNAs encode for a new class of nuclear proteins. The complete gene locus of the Ki-67 protein, comprising a 74 bp 5' region and a 264 bp 3' region, has been sequenced and aligned to a continuous sequence of 29,965 bp length located on chromosome 10q25-ter. The gene is organized in 15 exons with sizes from 67 to 6845 bp and in 14 introns with sizes from 87 to 3569 bp. Three introns contain homologue copies of 'Alu-repeats'. Interestingly, the introns flanking the alternative spliced exon 7 are free of any consensus donor and acceptor splicing signal. All other intron-exon transitions contained a potential branch site. The complete 5' region including the first two exons represents a CpG-rich island. We found the transcription initiation site in exon two adjacent to the consensus sequence of a cap site. Upstream of this cap site no TATA- or CCAAT-box could be located, but downstream we found two remarkable directly repeated elements of 24 bp lengths each containing a TATA box in inverse orientation.

Pathogenesis of coronavirus SD in mice. I. Prominent demyelination in the absence of infectious virus production.

Following intracerebral inoculation of 3- to 4-week-old C57 B16/J mice with coronavirus SD, 23% exhibited neurologic signs within the first week. However, only 6% died. Within the first week after inoculation (AI), we noted a panencephalitis. Prominent demyelination detected in the spinal cord on day 6 continued through day 29 AI. Demyelinated lesions in the spinal cord were either subpial with few inflammatory cells except for macrophages or perivascular with prominent accumulation of lymphocytes, plasma cells, and macrophages. Beginning on day 6 AI, IgG was detected in the lesions. Although an infectious virus was detectable in the CNS only through day 12 AI, viral antigen expression continued through day 24. We concluded that coronavirus SD persists in a nonrecoverable form throughout the initial phase of demyelination, day 6 to day 24 AI.

Assessment of cell proliferation by means of an enzyme-linked immunosorbent assay based on the detection of the Ki-67 protein.

A new ELISA system for the estimation of cell proliferation based on the detection of the Ki-67 protein is described. This protein has turned out to be strictly correlated to all active parts of the cell cycle, i.e., G1, S, G2, and mitosis, but is absent in G0. In addition, it is not detectable during DNA repair. In cultures of cell line cells as well as stimulated peripheral blood cells the values obtained with this ELISA system paralleled the [3H]thymidine uptake in different cell cultures. Thus, this assay provides a simple, non-radioactive assessment of proliferation of cultured cells.

Autoradiographic detection of IgG and viral antigens.

Autoradiographic methods can be used as an alternative to indirect immunofluorescence to detect viral antigen expression or the presence of IgG in tissue sections. Iodinated protein A isolated from Staphylococcus aureus detects an influx of IgG into the central nervous system of mice inoculated with the coronavirus SD. Antispecies antibody that has been iodinated detects coronavirus antigen expression for 24 days post-inoculation while it is only detectable for 10 days by immunofluorescence. A direct comparison of indirect fluorescence and autoradiographic methods indicates that the autoradiographic techniques are considerably more sensitive. This increased sensitivity is sufficient to permit the detection of viral antigen in formalin fixed paraffin embedded tissue sections.

Antisera with anti-pan C3 receptor reactivity which block complement C3b, C3bi and C3d receptors.

Antisera directed at human C3 receptors were prepared by 2 different methods. In method I rabbits were immunized with EAC coated with C3 receptors of tonsil cells (AC3RS type I). In method II rabbits were immunized with insoluble aggregates of tonsil membrane constituents containing significant amounts of C3 receptors. After appropriate absorptions both types of AC3RS showed a selective reactivity with those cells known to express C3 receptors. With the EAC rosette inhibition test it is demonstrated that both types of AC3RS contain antibodies against the binding sites of C3b, C3bi and C3d receptors. The antibody titer was consistently higher in AC3RS of type II.