Borna disease virus is not sensitive to amantadine

Summary.  Successful inhibition of Borna disease virus (BDV) by amantadine in cultured cells and in an infected human individual has been reported [Bode et al. (1997) Lancet 349: 178–179]. We now found that infection of monkey Vero cells by laboratory strains of BDV was not influenced by amantadine under conditions that reduced the yields of influenza A virus by about 400 fold. Amantadine treatment of Vero cells persistently infected with BDV did not result in reduced viral RNA levels, and application of the drug to persistently infected BALB/c mice had no effect on the concentration of BDV in their brains. Thus, susceptibility to amantadine is not a characteristic of BDV, although it may be observed with certain primary virus isolates. Received May 21, 1997 Accepted June 19, 1997     

End stopping in V1 is sensitive to contrast

Common situations that result in different perceptions of grouping and border ownership, such as shadows and occlusion, have distinct sign-of-contrast relationships at their edge-crossing junctions. Here we report a property of end stopping in V1 that distinguishes among different sign-of-contrast situations, thereby obviating the need for explicit junction detectors. We show that the inhibitory effect of the end zones in end-stopped cells is highly selective for the relative sign of contrast between the central activating stimulus and stimuli presented at the end zones. Conversely, the facilitatory effect of end zones in length-summing cells is not selective for the relative sign of contrast between the central activating stimulus and stimuli presented at the end zones. This finding indicates that end stopping belongs in the category of cortical computations that are selective for sign of contrast, such as direction selectivity and disparity selectivity, but length summation does not.     

Honey allergy is rare in patients sensitive to pollens

We challenged in a double-blind manner 46 pollen-allergic patients with 30 g of honey and another 32 patients with a placebo (30 g of syrup). Minor, mostly subjective, symptoms were seen in or reported by 26% of those challenged with honey and 41% of those challenged with placebo. In no case could the symptoms with certainty be related to the challenge. Eight commercially available honeys were examined for allergen activity by RAST inhibition and immunospot methods. Both pollen and insect allergen activity was found in all honeys, and they could cause allergic reactions. However, no serious or even obvious reaction occurred in pollen-allergic patients challenged with honey.     

The P300 is sensitive to concealed face recognition

In two experiments, we investigated whether a P300 based Concealed Information Test (CIT) can be used to detect concealed face recognition. The results show that detection of concealed face recognition is highly successful when stimuli depict persons who are personally highly familiar, and instructions to conceal recognition are given. When pictures depict recognized, but personally less familiar faces, and no specific instructions to conceal recognition are given, detection is unsuccessful. These findings indicate that pictures of faces can be used in a P300 based CIT, and that mere recognition is not sufficient for successful detection of concealed information.     

Osteointegration of titanium implant is sensitive to specific nanostructure morphology

An important aspect of orthopedic implant integration is the enhancement of functional activity of osteoblasts at the tissue-implant interface without any fibrous tissue intervention. Nanostructured implant surfaces are known to enhance osteoblast activity. Previously, we have reported a simple hydrothermal method for the fabrication of non-periodic nanostructures (nanoscaffold, nanoleaves and nanoneedles) on titanium implants showing good biocompatibility and a distinct osteoblast response in vitro in terms of osteoblast adhesion to the surface. In the present work, these nanostructures have been evaluated for their detailed in vitro cellular response as well as in vivo osteointegration. Our studies showed that a specific surface nanomorphology, viz. nanoleaves, which is a network of vertically aligned, non-periodic, leaf-like structures with thickness in the nanoscale, provided a distinct increase in osteoblast cell proliferation, alkaline phosphatase (ALP) activity and collagen synthesis compared to several other types of nanomorphology, such as nanotubes, nanoscaffold and nanoneedles (rods). Gene expression analysis of ALP, osteocalcin, collagen, decorin and Runx2 showed ~20- to 40-fold up-regulation on the leaf-like topography. Cytoskeletal arrangement studies on this substrate again revealed a unique response with favorable intracellular protein expressions of vinculin, FAK and src. In vivo osteointegration study over 12 weeks on rat model (Sprague-Dawley) showed early-stage bone formation (60% bone contact by week 2 and ~85% by week 8, p<0.01) in the leaf-like nanopattern, without any inflammatory cytokine production.     

The P300 is sensitive to concealed face recognition.

In two experiments, we investigated whether a P300 based Concealed Information Test (CIT) can be used to detect concealed face recognition. The results show that detection of concealed face recognition is highly successful when stimuli depict persons who are personally highly familiar, and instructions to conceal recognition are given. When pictures depict recognized, but personally less familiar faces, and no specific instructions to conceal recognition are given, detection is unsuccessful. These findings indicate that pictures of faces can be used in a P300 based CIT, and that mere recognition is not sufficient for successful detection of concealed information.     

Central gray modulation of affective defense is differentially sensitive to naloxone

Specific areas of feline central gray (CG) modulate affective aggression elicited by hypothalamic stimulation and produce analgesia, possibly mediated by enkephalins. Despite correlations between opiates and aggressive behavior suggested previously, their relationship has not been clearly demonstrated. The goal of this study was to examine the possible role of endogenous opiate mechanisms in CG modulation of affective aggression. Electrodes were placed in the ventromedial hypothalamus (VM) which, when stimulated, elicited affective attack. Control latency to VM-elicited hiss was established. CG cannula-electrodes were then implanted. Response modulation was determined by dual stimulation of CG and VM electrodes, alternated with VM stimulation alone. Naloxone was introduced through the CG electrodes and VM-elicited hiss latency was again determined, followed by paired trials of dual and single stimulation. Six ventral facilitatory and eight dorsal inhibitory sites were identified. Naloxone had no effect on CG facilitation but completely blocked CG inhibition of VM-elicited hissing. In support of these findings, it was observed that D-A1A2-MET5-enkephalin injected directly into CG-inhibitory sites suppressed VM-elicited hissing. These results demonstrate that opiate mechanisms are operative in the inhibitory modulation of intra-specific aggression.     

Family health history reporting is sensitive to small changes in wording

PurposeFamily health history is often collected through single-item queries that ask patients whether their family members are affected by certain conditions. The specific wording of these queries may influence what individuals report.MethodsParents of Boston Children’s Hospital patients were invited to participate in a Web-based survey about the return of individual genomic research results regarding their children. Participants reported whether 11 types of medical conditions affected them or their family. Randomization determined whether participants were specifically instructed to consider their extended family.ResultsFamily health history was reported by 2,901 participants. Those asked to consider their extended family were more likely to report a positive family history for 8 of 11 medical conditions. The largest differences were observed for cancer (65.1 vs. 45.7%; P < 0.001), cardiovascular conditions (72.5 vs. 56.0%; P < 0.001), and endocrine/hormonal conditions (50.9 vs. 36.7%; P < 0.001).ConclusionsSmall alterations to the way family health history queries are worded can substantially change patient responses. Clinicians and researchers need to be sensitive about patients’ tendencies to omit extended family from health history reporting unless specifically asked to consider them.Genet Med 18 12, 1308–1311.     

Persistent adhesion of epithelial tissue is sensitive to polymer topography.

The persistent adhesion of corneal epithelial tissue to the surface of a porous polymer is of interest in the development of a corneal onlay. Using an in vitro model system, this study examined the effect of polymer surface topography on the assembly of basement membrane and hemidesmosomes. Corneal epithelial tissue was grown on polycarbonate surfaces with a range of pore sizes (0.1-3.0 micron, pore diameter) and an equivalent nonporous surface. The ultrastructure of the tissue-polymer interface was evaluated using electron microscopy. On the porous surfaces, the tissue responded to a balance between the size of the discontinuity (pores) and the amount of polymer surface between the pores. Continuous basement membrane and a regular pattern of hemidesmosomal plaque occurred only on the 0.1 micron surface, where both the pores and the total surface area covered by pores were relatively small. The assembly of adhesive structures on surfaces with pore diameters between 0.4-2.0 microns was restricted to regions of polymer between pores. No adhesive structures assembled on the nonporous or on the 3.0-micron surface. These results demonstrate that, in addition to porosity, surface topography is a significant factor in the formation of structures involved in the persistent adhesion of stratified epithelial tissue on a polymer.     

Binding of perforin to membranes is sensitive to lipid spacing and not headgroup.

When triggered, cytolytic effector cells (cytolytic T-lymphocytes (CTL) and large granular lymphocytes (LGL)) release effector molecules from cytoplasmic granules, including the lytic protein perforin. This protein binds and incorporates into the plasma membrane of target cells, where it aggregates to form pores which cause target cell lysis and death. Phosphorylcholine, the headgroup of the ubiquitous phospholipids phosphatidylcholine (PC) and sphingomyelin, has been proposed as the specific receptor for perforin. We report here that any headgroup specificity is outweighed by phospholipid spacing in determining binding of perforin to liposomes. We also find that the spacing of outer leaflet lipids in a natural bilayer, the plasma membrane of the erythrocyte, influences susceptibility of the cell to perforin-mediated lysis. Finally, we demonstrate that the plasma membrane lipids in CTL are more closely spaced than in target cells, suggesting that lipid spacing contributes to the relative resistance of CTL to perforin-mediated lysis.     

The algorithmic complexity of multichannel EEGs is sensitive to changes in behavior

Symbolic measures of complexity provide a quantitative characterization of the sequential structure of symbol sequences. Promising results from the application of these methods to the analysis of electroencephalographic (EEG) and event-related brain potential (ERP) activity have been reported. Symbolic measures used thus far have two limitations, however. First, because the value of complexity increases with the length of the message, it is difficult to compare signals of different epoch lengths. Second, these symbolic measures do not generalize easily to the multichannel case. We address these issues in studies in which both single and multichannel EEGs were analyzed using measures of signal complexity and algorithmic redundancy, the latter being defined as a sequence-sensitive generalization of Shannon's redundancy. Using a binary partition of EEG activity about the median, redundancy was shown to be insensitive to the size of the data set while being sensitive to changes in the subject's behavioral state (eyes open vs. eyes closed). The covariance complexity, calculated from the singular value spectrum of a multichannel signal, was also found to be sensitive to changes in behavioral state. Statistical separations between the eyes open and eyes closed conditions were found to decrease following removal of the 8- to 12-Hz content in the EEG, but still remained statistically significant. Use of symbolic measures in multivariate signal classification is described.     

Visible light optical spectroscopy is sensitive to neovascularization in the dysplastic cervix

Neovascularization in cervical intraepithelial neoplasia (CIN) is studied because it is the precursor to the third most common female cancer worldwide. Diffuse reflectance from 450-600 nm was collected from 46 patients (76 sites) undergoing colposcopy at Duke University Medical Center. Total hemoglobin, derived using an inverse Monte Carlo model, significantly increased in CIN 2+ (N=12) versus CIN 1 (N=16) and normal tissues (N=48) combined with P<0.004. Immunohistochemistry using monoclonal anti-CD34 was used to quantify microvessel density to validate the increased hemoglobin content. Biopsies from 51 sites were stained, and up to three hot spots per slide were selected for microvessel quantification by two observers. Similar to the optical study results, microvessel density was significantly increased in CIN 2+ (N=16) versus CIN 1 (N=21) and normal tissue (N=14) combined with P<0.007. Total vessel density, however, was not significantly associated with dysplastic grade. Hence, our quantitative optical spectroscopy system is primarily sensitive to dysplastic neovascularization immediately beneath the basement membrane, with minimal confounding from vascularity inherent in the normal stromal environment. This tool could have potential for in vivo applications in screening for cervical cancer, prognostics, and monitoring of antiangiogenic effects in chemoprevention therapies.     

The visually-induced jump response of Drosophila melanogaster is sensitive to volatile anesthetics

Fruit flies jump when startled by a sudden decrease in light intensity. We show that this visually-induced jump response in Drosophila melanogaster is sensitive to three general anesthetic agents: halothane, enflurane, and methoxyflurane. The concentration of anesthetic required to inhibit this response is similar to that needed for the inhibition of other assays in flies and other organisms. We believe the simplicity of this assay coupled with the insight gained from the more complex electrophysiological monitoring of the same neural pathway will be of value in the genetic identification of the molecular target of volatile anesthetics.     

Sindbis virus maturation in cultured mosquito cells is sensitive to actinomycin D

In contrast to its effects on Sindbis virus production in vertebrate cell cultures, actinomycin D was found to inhibit the production of virus in cultured Aedes albopictus cells and Bombyx mori cells. One to two hours of incubation in the presence of actinomycin D was required for the inhibition to be observed. Synthesis and processing of virus structural polypeptides were found to be normal during the period of arrest of virus production. These data are interpreted as indicating the presence of a labile host function involved in the assembly of Sindbis virus components into mature virus in invertebrate host cells.