bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Future of Biothermal Engineeringa
Authors: CHATO JOHN C. , LEE RAPHAEL C. 
Published: February 2006

ABSTRACT: This is a report on a three‐day workshop held at the Allerton House of the University of Illinois. The first day consisted of invited tutorials on topics related to biothermal engineering: biological structures, analysis of microvascular heat transfer, temperature measurement, cryobiology and cryosurgery, burns, and industrial and consumer applications.The rest of the workshop consisted of discussions in ‘small groups and in plenary sessions dealing with relevant topics. Although the discussions endeavored to be as comprehensive as possible, the specific topics were selected by the participants based on their expertise and interests.The main areas examined were:

Instrumentation

Priority applications

Mathematical modeling

Thermal injury

The reliable measurement of the temperature distribution inside the living tissue is still the premier problem of instrumentation although the measurement of other parameters, such as properties, blood perfusion or heat flux, is also of great importance.The most important applications are medical, industrial, consumer, agricultural, space, and military. The degree of sophistication needed in the analysis of specific problems varies a great deal from relatively simple heat conduction models to complicated ones including blood perfusion, anisotropy, and the influence of large blood vessels. For many applications new experimental data are still needed.There have been significant advances in the modeling of living tissue with increasing understanding of its thermal behavior. The consensus was, however, that the models will always have to be tissue or organ specific and some new models are still to be developed.A new thermal injury classification for biological systems which has more meaning at the cellular and molecular level is needed to provide predictive value.Although not all aspects of biothermal engineering were covered, the findings of this workshop give a rather comprehensive overview of the field. It is the strong consensus of the participants that a periodic review of this type is of great benefit not only to the participants but to all workers in this field.
Mouse 5‐HT2B Receptor‐mediated Serotonin Trophic Functionsa
Authors: CHOI D.‐S. , KELLERMANN O. , RICHARD S. , COLAS J.‐F. , BOLAÑOS‐JIMENEZ F. , TOURNOIS C. , LAUNAY J.‐M. , MAROTEAUX L. 
Published: February 2006

ABSTRACT: 5‐HT2B receptors, in addition to phospholipase C stimulation, are able to trigger activation of the proto‐oncogene product p21ras. During mouse embryogenesis, a peak of 5‐HT2B receptor expression is detected at the neurulation stage; we localized the 5‐HT2B expression in neural crest cells, heart myocardium, and somites. The requirement for functional 5‐HT2B receptors shortly after gastrulation, is supported by culture of embryos exposed to 5‐HT2B‐high affinity antagonist such as ritanserin, which induces morphological defects in the cephalic region, heart and neural tube.Functional 5‐HT2B receptors are also expressed during the serotonergic differentiation of the mouse F9 teratocarcinoma‐derived clonal cell line 1C11. Upon 2 days of induction by cAMP, 5‐HT2B receptors become functional, and on day 4, the appearance of 5‐HT2A receptors coincides with the onset of active serotonin transporter by these cells. Active serotonin uptake is modulated by serotonin suggesting autoreceptor functions for 5‐HT2B receptors.
Fighting Nerve Agent Chemical Weapons with Enzyme Technology
Authors: LEJEUNE KEITH E. , DRAVIS BRYAN C. , YANG FANGXIAO , HETRO AMY D. , DOCTOR BHUPENDRA P. , RUSSELL ALAN J. 
Published: February 2006

Abstract: The extreme toxicity of organophosphorous‐based compounds has been known since the late 1930s. Starting in the mid‐1940s, many nations throughout the world have been producing large quantities of organophosphorous (OP) nerve agents. Huge stockpiles of nerve agents have since developed. There are reportedly more than 200,000 tons of nerve agents in existence worldwide. There is an obvious need for protective clothing capable of guarding an individual from exposure to OP chemical weapons. Also, chemical processes that can effectively demilitarize and detoxify stored nerve agents are in great demand. The new and widely publicized Chemical Weapons Treaty requires such processes to soon be in place throughout the world. Biotechnology may provide the tools necessary to make such processes not only possible, but quite efficient in reducing the nerve agent dilemma.The following paper discusses some of the history in developing enzyme technology against nerve agents. Our laboratory has interest in enhancing the productivity and potential utility of these systems in both demilitarization and decontamination applications. Freeze‐dried nerve agent‐hydrolyzing enzyme preparations have been shown to be effective in decontaminating gaseous nerve agents. The direct incorporation of nerve agent‐hydrolyzing enzymes within cross‐linked polyurethane foam matrices during polymer synthesis has been shown to dramatically enhance the productivity of two different enzyme systems. The future goal of such work lies in building a bridge between the clinical application of nerve agent‐hydrolyzing enzymes and practical processing techniques that may take advantage of the initial results already achieved in the laboratory.
The Dynamics of Globin Gene Expression and Gene Therapy Vectors
Authors: GROSVELD FRANK , DE BOER ERNIE , DILLON NIALL , GRIBNAU JOOST , MILOT ERIC , TRIMBORN TOLLEIV , WIJGERDE MARK , FRASERA PETER 
Published: February 2006

Abstract:The most important level of regulation of the β‐globin genes is by activation of all of the genes by the Locus Control Region (LCR) and repression of the early genes by an as yet unknown factor acting on sequences flanking the genes. Superimposed on this is a mechanism in which the early genes (ɛ and γ) suppress the late genes (δ and β) by competition for the interaction with the LCR. Although this extra level of gene regulation is quantitatively of less importance than the direct repression mechanism, it has important implications and has provided an excellent assay system to probe the regulation of transcription at the single cell level.These studies indicate that the LCR interacts with individual globin genes and that LCR/gene interactions are dynamic with complexes forming and dissociating continually. The levels of expression of each of the genes appear to depend on: 1) the frequency of interaction which is itself dependednt on the distance of the gene to the LCR, 2) the affinity of the LCR for the gene and 3) the stability of the LCR/gene complex. The latter two are dependent on the balance of transcription factors. We conclude that transcription only appears to take place while the LCR and gene interact and that the level of transcription is determined by the frequency and duration of such interaction rather than by changes in the rate of transcription of promoters.
Neurotrophic Factors in the Tongue: Expression Patterns, Biological Activity, Relation to Innervation and Studies of Neurotrophin Knockout Micea
Authors: NOSRAT CHRISTOPHER A. 
Published: February 2006

ABSTRACT: How taste buds develop and how they become innervated has been a matter of debate for a long time. Brain‐derived neurotropic factor (BDNF) and neurotrophin‐3 (NT3) mRNA expression patterns suggested a possible involvement in lingual gustatory and somatosensory innervation. Studies of null‐mutated mice showed that BDNF−/− mice had few abnormal taste buds and were unable to discriminate between primary tastes. NT3−/− mice had a severe loss of lingual somatosensory innervation. These novel findings may have clinical implications in rare human conditions such as familial dysautonomia and/or in more common cases of problems with loss of taste and sensation in the mouth such as those seen after injury to the nerves, either by accident or following oral/facial surgery. Knowledge about which proteins that are required to stimulate nerve fibers to grow into mucous membranes of the oral cavity during development suggests that these same proteins might become helpful in stimulating regeneration of injured nerves in patients, perhaps helping them to regain lost taste and sensory functions.Here, the presence of glial cell‐derived neurotrophic factor (GDNF) families of neurotrophic factors and receptors in the tongue is also discussed. Further, a model for the development and innervation of taste buds in mammals is proposed.
Quantitative Relationships between Taste Bud Development and Gustatory Ganglion Cellsa
Authors: KRIMM ROBIN F. , HILL DAVID L. 
Published: February 2006

ABSTRACT: To determine whether patterns of taste bud innervation change during postnatal rat development, the number of geniculate ganglion cells that innervate single taste buds were quantified in adult and developing rats. While there was a large variation in numbers of ganglion cells that innervate individual taste buds, there was a high degree of organization in the system. Namely, the number of labeled geniculate ganglion cells innervating a taste bud was highly correlated with the size of the taste bud. This relationship between taste bud size and number of innervating ganglion cells develops over a prolonged postnatal period and is not established until postnatal day 40 (P40), when taste buds reach their adult size.In a second series of experiments, we sought to determine whether neural rearrangement of chorda tympani neurons is responsible for the development of this relationship by double‐labeling single taste buds at different ages. We found that the number of ganglion cells innervating individual taste buds on P10 predicts the size that taste buds become by P40. This finding suggests that neural rearrangement is not responsible for establishing the relationship between taste bud size and the number of innervating ganglion cells during development. More importantly, it strongly suggests that the 'neural template' for the mature innervation pattern is determined during early postnatal development.
Differentiation in an Olfactory Cell Line: Analysis via Differential Displaya
Authors: ZEHNTNER SIMONE P. , MACKAY‐SIM ALAN , BUSHELL GILLIAN R. 
Published: February 2006

ABSTRACT: The olfactory epithelium is a unique system, in which new neurons are continually generated throughout adult life. Olfactory neurons are derived from stem cells that lie adjacent to the basal lamina of the olfactory epithelium; these stem cells divide several times and their progeny differentiate into mature sensory neurons. In our laboratory immortalized cell lines have been derived from these dividing cells. The morphology of these cell lines and their expression of neuronal markers varies with culture conditions. When grown in low serum medium one of these cells lines, OLF 442, differentiates by extending long neurites and increasing its expression of neurofilament and B50/GAP43 proteins at the same time reducing expression of glial fibrillary acidic protein (GFAP).Identification of differentially expressed mRNA in cell lines has previously relied on both screening for known markers, and the use of subtractive techniques for identification of unique mRNA species. The differential display technique allows simultaneous detection of differentially expressed mRNA at different time periods and growth conditions. A modified Liang and Pardee differential display technique was used to screen OLF 442 over a number of time intervals in serum‐depleted media, and compared with OLF 442 grown in complete media. The differentially displayed fragments were cloned and sequenced, leading to the identification of a number of sequences, both known and unknown. The known sequences include SPARC (encoding a Ca2+ binding secreted Protein which is Acidic and Rich in Cysteine), which is reported to function as a modulator of the cell matrix, and RHAMM, the receptor for hyaluronan‐mediated motility. Both the known and the unknown sequences are being studied further to provide insight into the differentiation of olfactory neurons.
Inhibitors of Sensillar Esterase Block Reversibly the Responses of Moth Pheromone Receptor Cells
Authors: POPHOF B. 
Published: February 2006

ABSTRACT: The Pheromone of Antheraea polyphemus is slowly (within min) degraded by a sensillum lymph specific esterase. The effects of two volatile alkyl‐thio‐trifluoro‐methyl‐ketones with alkyl chain length of six (HTFP) and ten carbons (DTFP), which selectively inhibit the activity of the sensillar esterase, were tested.Single sensillum recordings from sensilla trichodea were performed on isolated antennae either held in a continuous stream of clean air, or exposed to an airstream containing one of the esterase inhibitors. Afterwards the antennae were stimulated with the Pheromone components (E,Z)‐6,11‐hexadecadienyl acetate and (E,Z)‐6,11‐hexadecadienal. Both esterase inhibitors caused a reduction of electrophysiological responses to each of the two Pheromone compounds. The DTFP was slightly more effective then HTFP. An almost complete block of the receptor potential amplitude and nerve impulse response was achieved within seconds of exposure to the inhibitors. Responses of both Pheromone receptor cells were reduced to the same extent. The half‐times of rise and decline of the receptor potential remained unaffected in most cells. The responses to Pheromone partially recovered to ~50‐70% within several min in clean air.An inhibition of the sensillar esterase cannot explain the observed effects. The inhibitors could either react directly with the receptor molecules, thereby inhibiting the action of the Pheromone, or bind to the Pheromone‐binding protein (PBP) and prevent the formation of the Pheromone‐PBP complex stimulating the receptor.
Neural Circuits for Taste: Excitation, Inhibition, and Synaptic Plasticity in the Rostral Gustatory Zone of the Nucleus of the Solitary Tracta
Authors: BRADLEY ROBERT M. , GRABAUSKAS GINTAUTAS 
Published: February 2006

ABSTRACT: The rostral nucleus of the solitary tract (rNST) plays a key role in modulating, organizing and distributing the sensory information arriving at the central nervous system from gustatory receptors. However, except for some anatomical studies of rNST synapses, the neural circuits responsible for this first stage in synaptic processing of taste information are largely unknown. Over the past few years we have used an in vitro brain slice preparation of the rNST to study synaptic processing, and it has become apparent that the rNST is a very complex neural relay.Synaptic potentials recorded in rNST neurons resulting from stimulation of afferent taste fibers are a composite of excitatory and inhibitory post synaptic potentials. Pure excitatory postsynaptic potentials (EPSP) can be isolated by using γ‐aminobutyric acid type A (GABAA) receptor blockers to eliminate the inhibitory postsynaptic potentials (IPSP). Application of glutamate ionotropic receptor blockers effectively eliminates all postsynaptic activity, indicating that glutamate is the transmitter at the first central synapse in the taste pathway. Stimulation of the afferent taste fibers originating from the anterior (chorda tympani) and posterior (glossopharyngeal) tongue results in a postsynaptic potential that is a complex sum of the two individual potentials. Thus, rNST neurons receive convergent synaptic input from the anterior and posterior tongue.The IPSP component of the synaptic potentials in rNST results from stimulation of interneurons. If these IPSPs are initiated by tetanic stimulation they undergo both short‐term and long‐term changes. Short‐term changes result in the development of biphasic depolarizing IPSPs, and long‐term changes result in potentiation of the IPSPs that can last over an hr in some neurons. This remarkable synaptic plasticity may be involved in the mechanism of learned taste behaviors.Synaptic transmission in rNST consists of excitation combined with inhibition. The inhibition does not simply depress excitation but probably serves many roles such as shaping and limiting excitation, coordinating the timing of synaptic events and participating in synaptic plasticity. Knowledge of these synaptic mechanisms is essential to understanding how the rNST processes taste information.
Ipsilateral Dominance of Human Olfactory Activated Centers Estimated from Event‐Related Magnetic Fields Measured By 122‐Channel Whole‐Head Neuromagnetometer Using Odorant Stimuli Synchronized with Respirations
Authors: TONOIKE MITSUO , YAMAGUCHI MASAHIKO , KAETSU ISAO , KIDA HIROYUKI , SEO RITSU , KOIZUKA IZUMI 
Published: February 2006

ABSTRACT:The aim of this study was to measure and analyze olfactory event‐related magnetic fields using a whole‐cortex biomagnetometer (122‐channel SQUID gradiometer). Amyl‐acetate gas (approx. 1%) was administered for 300 msec into either the right or left nostril in synchronization with respiration using a mask and an optical fiber sensor. Clear olfactory event‐related magnetic fields were asymmetrically obtained on both sides of the forehead in all six subjects. The generators of olfactory magnetic fields were estimated at two regions located fairly asymmetrivally near the bilateral frontal deep areas. The goodness‐of‐fit was better for the two‐dipole model than the one‐dipole model in all experiments.In almost all subjects the latency and intensity of ipsilateral olfactory magnetoencephalography (MEG) responses were shorter and larger than those of the contralateral responses, respectively.These results suggest that the olfactory MEG responses on the ipsilateral side are generally larger and more dominant than those on the contralateral side in the human olfactory system.
Central Nervous Correlates of Chemical Communication in Humansa
Authors: KRAUEL KERSTIN , PAUSE BETTINA M. , MUELLER CLAUDIA , SOJKA BERNFRIED , MUELLER‐RUCHHOLTZ WOLFGANG , FERSTL ROMAN 
Published: February 2006

ABSTRACT: The recording of chemosensory event‐related potentials (CSERPs) has been established as an objective method in the assessment of central odor processing in humans. In the present study CSERPs were used to investigate whether human body odor is genetically determined by the major histocompatibility complex (MHC), referred to in humans as the human leukocyte antigen (HLA). The immunological function of the MHC is the discrimination of self/nonself within the immune system. In rodents it has been shown that body odor is significantly influenced by the MHC and that it can be discriminated by members of different species.To create a sufficiently large subject pool, 144 subjects were screened for their HLA class I loci A and B. During the electroencephalography (EEG) session the subjects (n= 40/20 women) were confronted with the body odor (axillary hair) of three different donors. Two donors (d1 and d2) were HLA‐similar but had a different HLA type than the third donor (d3) and the perceiving subject. The third donor and the perceiver shared a similar HLA type. Half of the perceivers received odors from donors of the same sex, the other half smelt odors from donors of the opposite sex. In the EEG session subjects were presented with 200 trials. The odors were delivered through a constant flow olfactometer nonsynchronously to breathing. The odor of d1 appeared frequently (p= 0.6) whereas the odors of d2 and d3 appeared each at a rate of p= 0.2. During half the trials the subjects were instructed to respond to the odor of d2, during the other half to the odor of d3. The EEG was recorded from Fz, Cz, Pz, F3, P3, F4 and P4 in reference to linked mastoids. First results show that male perceivers show enhanced potentials in response to male donors of a similar HLA type (d3). The CSERP results of the other groups as well as valence and attractiveness ratings will be discussed.
Focused Attention and the Detectability of Weak Gustatory Stimuli: Empirical Measurement and Computer Simulationsa
Authors: MARKS LAWRENCE E. , WHEELER MARY E. 
Published: February 2006

ABSTRACT: Attentional processes can modulate the detectability of weak stimuli; for example, the detectability of visual or auditory signals can depend on whether attention is allocated to the appropriate spatial location (vision) or acoustic frequency (hearing). Earlier attempts in the first author's laboratory to find analogous effects of focused attention on the detectability of taste stimuli were equivocal, in part it seems because human gustatory sensitivity can fluctuate substantially over time, a serious problem when using procedures that track sensitivity (d') to a constant stimulus concentration. To circumvent this problem, we adopted an adaptive psychophysical procedure, the transformed up‐down method, using a 3‐down/1‐up rule to determine how the threshold to detect weak concentrations of sucrose and citric acid depended on whether the stimulus presented in a given two‐alternative, forced‐choice trial was expected or unexpected. The results showed threshold sensitivity to he slightly but consistently poorer when the test stimulus was unexpected (e.g., sucrose presented when citric acid was expected) than it was when the test stimulus was expected (e.g., sucrose presented when sucrose was expected).In this attentional paradigm, the unexpected stimulus must perforce be presented on only a small fraction of the trials. In selecting a procedure, we chose a 3‐down/1‐up adaptive rule rather than the more popular 2‐down/1‐up rule, a choice that turned out to be in line with results of Monte Carlo computer simulations. These simulations suggest that across a wide range of conditions (starting stimulus concentrations, step sizes), the variability in threshold measurements can he smaller with a 3‐down/1‐up rule than with a 2‐down/1‐up rule, even when the total number of trials is the same and not very great.
The Use of Olfactory Receptor Neurons (ORNs) from Biopsies to Study Changes in Aging and Neurodegenerative Diseasesa
Authors: RAWSON NANCY E. , GOMEZ GEORGE , COWART BEVERLY , RESTREPO DIEGO 
Published: February 2006

ABSTRACT: A gradual loss of olfactory capability with age and in a number of neurodegenerative diseases is common, and mechanisms underlying these losses are not understood. We determined the feasibility of using ORNs obtained from olfactory epithelial biopsies to identify possible changes in ORN function that may contribute to olfactory impairment in these individuals. ORNs from nine healthy subjects (66‐84 yr), three patients with Alzheimer's disease and one with multi‐infarct dementia were studied with calcium imaging techniques and two odorant mixtures. Seventy‐five viable ORNs were studied; 53% of these were odorant responsive, and twenty percent of these responded to both odorant mixtures. In contrast, 25% of 173 ORNs from younger subjects were odorant responsive, and none of these responded to both odorant mixtures. The proportion of cells responding to each of the odorant mixtures also differed between older and younger subjects.These studies demonstrate the feasibility of this approach to examine age or disease‐associated changes in neuronal function. Further, age‐related changes in ORN selectivity may contribute to changes in olfactory perfor mance.