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OBJECTIVE: To assess the medial plantar nerve action potential (NAP) and skin biopsy in the evaluation of suspected distal sensory neuropathies (SN) with normal routine nerve conduction studies (NCS). METHODS: A total of 110 consecutive patients with suspected distal SN and normal routine NCS underwent medial plantar NAP testing and punch skin biopsy. Patients were clinically stratified as having pure small fiber sensory neuropathy (SFSN), or distal SN with large fiber involvement (SN-LFI). RESULTS: A total of 56 patients were classified as SN-LFI and 54 SFSN. The medial plantar NAP, a measure of large fiber function, was abnormal in 31.8% of patients, more frequently in SN-LFI than SFSN. Distal leg epidermal nerve fiber (ENF) density, a measure of small fibers, was reduced in 47.3% of biopsies, with isolated ENF morphologic changes in 29.1% and normal findings in 23.6%. Biopsy abnormalities were more severe and prevalent in SN-LFI than in SFSN. In patients with a normal medial plantar NAP, distal leg biopsy showed reduced ENF density in 34.7%, and isolated morphologic changes in a further 37% of cases. CONCLUSIONS: The medial plantar nerve action potential and skin biopsy are complementary in evaluation of distal SN with normal routine NCS. Small sensory nerve fibers are affected early in SN, and more severely so when large fiber involvement is apparent clinically.

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Nutrition screening identifies individuals who are malnourished or at risk of becoming malnourished and who may benefit from nutrition support. The aim of this study was to validate a new malnutrition screening tool (MST) in cancer patients undergoing radiotherapy. The MST was compared with the subjective global assessment (SGA) of nutritional status. One hundred and six patients attending two cancer care centres in Australia were independently rated as well nourished or malnourished using SGA and at risk or not at risk of malnutrition using the MST. Convergent validity of the MST was established by determining the ability of the MST to predict SGA. According to SGA, 89% of the patients were well nourished and 11% were moderately malnourished. According to the MST, 28% of patients were at risk of malnutrition. The MST had a sensitivity of 100% and a specificity of 81%. The positive predictive value was 0.4 and the negative predictive value was 1.0. The MST is easy to use and is a strong predictor of nutritional status. The malnutrition screening tool is a simple, quick, valid tool that can be used to identify radiation oncology outpatients who are at risk of malnutrition.

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Gravitational billiards provide a simple method for the illustration of the dynamics of Hamiltonian systems. Here we examine a new billiard system with two parameters, which exhibits, in two limiting cases, the behaviors of two previously studied one-parameter systems, namely the wedge and parabolic billiard. The billiard consists of a point mass moving in two dimensions under the influence of a constant gravitational field with a hyperbolic lower boundary. An iterative mapping between successive collisions with the lower boundary is derived analytically. The behavior of the system during transformation from the wedge to the parabola is investigated for a few specific cases. It is surprising that the nature of the transformation depends strongly on the parameter values. (c) 1999 American Institute of Physics.

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The yellow fever mosquito, Aedes aegypti, transmits pathogens that affect both humans and livestock, and has been the focus of extensive research to identify genetic loci that may be useful in control strategies. Fluorescence in situ hybridization (FISH) and digital imaging microscopy have provided a rapid mechanism to populate the physical map with probes derived from genetic markers, cDNAs and recombinant genomic libraries. When the physical and genetic linkage maps are aligned, map-based cloning will allow the rapid isolation of target genomic sequences. The strategy of FISH mapping and the results of initial hybridization studies are reviewed here by Martin Ferguson, Susan Brown and Dennis Knudson. An Ae. aegypti-specific genomic database, which collates data from mapping studies, sequences, references and other relevant information, is also discussed.

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Few investigators have attempted to examine empirically the relationship between perception of autonomic arousal and emotional state. According to Jamesian theory, individuals who are more aware of their visceral activity should demonstrate greater affective response to emotion-laden stimuli than individuals who are not viscerally perceptive. Therefore, certain groups of 'unemotional' subjects, such as anhedonics, may report fewer or less intense emotional experiences due to an attenuation or lack of autonomic feedback. Results from studies by Katkin (Psychophysiology, 22, (1985) 125-137) suggest that there is a relationship between induced sympathetic arousal, the perception of that arousal, and the self-report of emotional experience. The present study sought to expand upon these findings by comparing visceral perception (i.e. heartbeat detection) performance and a multi-component assessment of emotion in normal and anhedonic subjects. No correlation was found between anhedonia and visceral perception; however, anhedonics were significantly different from normals across several measures of heart rate, self-report, and facial expressions in response to emotion-eliciting slides, with anhedonics consistently showing emotional hypo-responsiveness. Additionally, subjects who were able to perceive their own heartbeats were found to be more facially expressive than poor perceivers.

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Kinetoplast DNA, the mitochondrial DNA of trypanosomatid parasites, is a network containing several thousand minicircles and a few dozen maxicircles. We compared kinetoplast DNA replication in Trypanosoma brucei and Crithidia fasciculata using fluorescence in situ hybridization and electron microscopy of isolated networks. One difference is in the location of maxicircles in situ. In C. fasciculata, maxicircles are concentrated in discrete foci embedded in the kinetoplast disk; during replication the foci increase in number but remain scattered throughout the disk. In contrast, T. brucei maxicircles generally fill the entire disk. Unlike those in C. fasciculata, T. brucei maxicircles become highly concentrated in the central region of the kinetoplast after replication; then during segregation they redistribute throughout the daughter kinetoplasts. T. brucei and C. fasciculata also differ in the pattern of attachment of newly synthesized minicircles to the network. In C. fasciculata it was known that minicircles are attached at two antipodal sites but subsequently are found uniformly distributed around the network periphery, possibly due to a relative movement of the kinetoplast disk and two protein complexes responsible for minicircle synthesis and attachment. In T. brucei, minicircles appear to be attached at two antipodal sites but then remain concentrated in these two regions. Therefore, the relative movement of the kinetoplast and the two protein complexes may not occur in T. brucei.

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By using the computer in the ways mentioned, students learn important communication skills. The fact that they have fun in the process is an added bonus and a great motivator for changing behavior. The information given is by no means all-inclusive. Each speech-language pathologist can use his or her own ideas and creativity to develop treatment materials. The possibilities are endless.

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This study evaluated the retest reliability of a number of inotropic and chronotropic indexes of cardiovascular reactivity to mental arithmetic stress over a 1-week interval. Differential habituation effects of the dependent measures were also assessed. 15 male and 15 female undergraduate Ss were administered a mental arithmetic task (serial subtractions by 13 from a 4-digit number) for 1-min on two successive weeks while their electrocardiogram and impedance cardiogram were recorded. Dependent measures included HR, PEP, HI, SV and CO. Results indicate that all dependent measures were reliable.

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In Necturus gallbladders bathed in a NaCl Ringer solution buffered with 10 mM HCO3(-)-1% CO2, furosemide (added to the serosal solution) caused a concentration-dependent hyperpolarization of both cell membranes that was slow and reversible. At 10(-3) M furosemide, the basolateral membrane voltage (Vcs) increased significantly from -71 +/- 3 to -85 +/- 3 mV, the depolarization of Vcs elicited by a 10-fold rise in serosal [K+] increased from 34 +/- 4 to 50 +/- 1 mV, the depolarization elicited by lowering serosal [Cl-] from 98 to 8.1 mM was reduced from 15 +/- 1 to 1 +/- 1 mV, and the depolarization in response to lowering serosal [HCO3-] from 10 to 1 mM was reduced from 13 +/- 1 to 5 +/- 0.4 mV. Furosemide could in principle decrease the basolateral membrane Cl- conductance (Gcl), increase the basolateral membrane K+ conductance, or have a combined effect. To distinguish among these possibilities, we estimated the resistance of the basolateral membrane (Rb) by means of two-point intraepithelial cable analysis experiments. Furosemide increased Rb by 22%, which indicates that furosemide reduces basolateral membrane Gcl. The effect cannot be attributed to inhibition of apical membrane anion exchange by serosal addition of furosemide, because base secretion from cells to lumen is unchanged. We conclude that furosemide blocks reversibly basolateral membrane electrodiffusive Cl- permeability. A concomitant stimulation of basolateral membrane electrodiffusive K+ permeability is also possible.

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Research on loneliness has been hindered by the lack of a simple and reliable assessment technique. The development of the UCLA Loneliness Scale, a short, 20-item general measure of loneliness is reported. The measure has high internal consistency (coefficient alpha = .96) and a test-retest correlation over a two-month period of .73. Concurrent and preliminary construct validity are indicated by correlations with self-reports of current loneliness and related emotional states, and by volunteering for a "loneliness clinic."

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