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PubMed1994

Comparison of the ProSpecT and Color Vue enzyme-linked immunoassays for the detection of Cryptosporidium in stool specimens.

Two enzyme-linked immunosorbent assays, the ProSpecT (Al-exon, Sunnyvale, CA, USA) and the Color Vue (Seradyn, Indianapolis, IN, USA) were compared for their ability to detect Cryptosporidium in 236 formalin-fixed stool specimens using the Merifluor C/G (Meridian, Cincinnati, OH, USA) stain as the reference method. The initial sensitivities of the ProSpecT and the Color Vue were 96.0% and 76.0%, which upon repeat testing of all discrepancies remained at 96.0% for the ProSpecT and decreased to 72.0% for the Color Vue. There were 25 (11%) specimens positive by the reference method. Initially, there were five false positive specimens by the ProSpecT, only one of which remained positive on retesting. The specificity of the Color Vue was 100% for the initial and repeated results, whereas the ProspecT had an initial specificity of 97.6% that increased to 99.5% upon repeat testing. The enzyme-linked immunosorbent assays offered the advantages of objectivity, batch testing, and, in the case of the ProSpecT, an acceptable sensitivity.

Animals↗
PubMedDate not supplied

Imaging implications in the evaluation of permanent needle acupuncture.

Traditional Chinese acupuncture involves placing needles into the subcutaneous tissues along predefined meridians, and later totally removing the needles. A peculiar form of acupuncture exists called "Hari", which involves the permanent placement of fine needles into the subcutaneous tissues. Although this form of acupuncture is uncommon, it is still practiced in both the Orient and the West. Following treatment, the patient's skin is imbedded with hundreds of these fine needles, which remain in the skin for the rest of the patient's life. Several reports have appeared describing their curious radiologic appearance. We present plain films, sonograms, and computed tomography findings of three patients who have undergone this form of acupuncture, and describe their implications in radiographic and clinical evaluation.

Acupuncture Points↗
PubMed1993

Motion-onset visual-evoked potentials as a function of retinal eccentricity in man.

Visual-evoked potentials were elicited by the motion-onset of a black-and-white square-wave grating of 2.4 cycles/deg that drifted from right to left at a velocity of 3 deg/s. The center of the 2 x 2 deg stimulus field was binocularly viewed either foveally or at eccentricities of 6, 12, or 20 deg in the lower visual field along the vertical meridian. Peak-to-peak amplitudes P1-N2 and N2-P2 were found to decrease non-linearly as a function of eccentricity. The VEP-amplitudes were standardized by setting each foveal value to 100%, and a relative measure was derived for peripheral values given by the ratio of the peripheral to the foveal values. The decrease of the relative VEP-values with eccentricity was significantly smaller than that of the relative cortical magnification factor of striate cortex in man, whereas it agreed fairly well with that of the relative point-image size of the area MT in Macaque monkey. In this respect, the motion-onset VEP is distinct from the pattern-reversal VEP, the amplitude of which decreases much more rapidly with retinal eccentricity; hence, it may involve different generating structures of the brain.

Adolescent↗
PubMedDate not supplied

Visualization of myosin helices in sections of rapidly frozen relaxed tarantula muscle.

Tarantula leg muscles in the relaxed state were rapidly frozen against a copper block cooled with liquid helium. Thin longitudinal sections of freeze-substituted specimens, both live and skinned, clearly showed the helical tracks of crossbridges on the surface of the myosin filaments, which are not preserved by conventional fixation. Fourier transforms of selected filaments showed a myosin layer line pattern, similar to that observed in X-ray diffraction patterns of intact tarantula muscle, extending to the sixth order of the 43.5 nm X-ray repeat. The phases of corresponding reflections were similar on the two sides of the meridian on the first layer line, and the crossbridge arrangement showed a line of mirror symmetry running down the center of the filament. These observations show that the number of helices (N) is even, in agreement with N = 4 determined from image analysis of negatively stained, isolated tarantula filaments (Crowther et al., J. Mol. Biol. 184, 429-439, 1985). Filtered images showed clear detail of the crossbridge helices and were similar to filtered images of negatively stained, isolated thick filaments. Thus, rapid freezing combined with freeze-substitution preserves the crossbridges in a three-dimensional arrangement approximating that occurring in vivo.

Animals↗
PubMed2004

Human acupuncture points mapped in rats are associated with excitable muscle/skin-nerve complexes with enriched nerve endings.

As part of our ongoing investigation into the neurological mechanisms of acupuncture, we have tried to correlate the distribution of afferent nerve endings with acupuncture points (AP) in the rat hind limbs. In vivo extracellular microfilament recordings of Aalpha/Abeta/Adelta fibers were taken from peripheral nerves to search for units with nerve endings or receptive fields (RF) in the skin or the muscles. The location of the RFs for each identified unit was marked on scaled diagrams of the hind limb. Noxious antidromic stimulation-induced Evans blue extravasation was used to map the RFs of C-fibers in the skin or muscles. Results indicate that, for both A- and C-fibers, the distribution of RFs was closely associated with the APs. In the skin, the RFs concentrate either at the sites of APs or along the orbit of meridian channels. Similarly, the majority of sarcous sensory receptors are located at the APs in the muscle. Results from our studies strongly suggest that APs in humans may be excitable muscle/skin-nerve complexes with high density of nerve endings.

Acupuncture Points↗
PubMed2006

Visual spatial integrity in the absence of splenium.

Several lines of evidence have confirmed that visual integrity among the two hemifields is severely impaired following transection of posterior part of the corpus callosum (splenium). But the extent of this impairment differs for various visual functions. Here, in a posterior callosectomized patient (MD), interhemispheric visual spatial integrity is investigated in three experiments. In the first experiment, MD was asked to make decision about horizontal alignment of two balls presented simultaneously in one of three conditions: both in right or left hemifield, or each in one hemifield. We have previously shown that she is not able to perform a shape-matching task for stimuli presented to different hemifields. But in this task, MD was able to compare location of the two bilaterally presented stimuli significantly above chance level. Then we investigated whether attentive visual object tracking across vertical meridian of the visual field is possible in the absence of splenium. MD had to attentively track one bouncing ball among three identical balls, while it crossed the vertical midline in half of trials. Her performance in crossed conditions was significantly above chance level, but it was lower than uncrossed conditions. Finally, we investigated the contribution of simple interhemispheric temporal signals in performing the attentive tracking task. Results suggest that the patient was not using such temporal signals. Our results suggest that interhemispheric connections other than splenium can contribute in making an integral visual map across hemifields. Such an integrated map can be used for bilateral visual spatial comparisons and visual spatial attention.

Adult↗
PubMed2006

A TMS examination of semantic radical combinability effects in Chinese character recognition.

The proposal of human foveal splitting assumes a vertical meridian split in the foveal representation and the consequent contralateral projection of information in the two hemifields to the two hemispheres and has been shown to have important implications for visual word recognition. According to this assumption, in Chinese character recognition, the two halves of a centrally fixated character may be initially projected to and processed in different hemispheres. Here, we describe a repetitive transcranial magnetic stimulation (rTMS) investigation of hemispheric processing in Chinese character recognition, through examining semantic radical combinability effects in a character semantic judgment task. The materials used were a dominant type of Chinese character which consists of a semantic radical on the left and a phonetic radical on the right. Thus, according to the split fovea assumption, the semantic and phonetic radicals are initially projected to and processed in the right hemisphere and the left hemisphere, respectively. We show that rTMS over the left occipital cortex impaired the facilitation of semantic radicals with large combinability, whereas right occipital rTMS did not. This interaction between stimulation site and radical combinability reveals a flexible division of labor between the hemispheres in Chinese character recognition, with each hemisphere responding optimally to the information in the contralateral visual hemifield to which it has direct access. The results are also consistent with the split fovea claim, suggesting functional foveal splitting as a universal processing constraint in reading.

Adult↗
PubMed2003

MR demonstration of partial lesions of the lateral geniculate body and its functional intra-nuclear topography.

Two rare cases with a partial lesion of the lateral geniculate body (LGB) presumably due to ischemia are demonstrated on high resolution MR imaging. A 62-year-old woman (case 1) presented with left homonymous superior quadrantanopia on Goldmann perimetry. Heavily T2 weighted MR images showed a localized lesion at the lateral portion of the LGB. The visual field defect was macular and horizontal meridian sparing and persisted for 9 years. A 49-year-old woman (case 2) presented with a sudden onset of left homonymous horizontal sectoranopia on Humphrey automated perimetry and heavily T2 weighted images demonstrated a lesion localized at the more medial part of the right LGB. Axons originating from inferior, central and superior retina are essentially located laterally, centrally and medially, respectively, in the LGB, based on the electrophysiological studies of animal experiments and this observation has been applied to humans. This study radiologically shows that a discrete lateral lesion of the LGB produced homonymous upper quadrantanopia in case 1, whereas a more medially located lesion produced homonymous sectoranopia in case 2, and reveals that the axons originating from inferior retina are located more laterally than those from central retina in the human LGB.

Axons↗
PubMed2005

Multifocal visual evoked potentials--a method study of responses from small sectors of the visual field.

OBJECTIVE: A method study of the mfVEP technique to establish a standardised way to identify stable response components from small areas in all parts of the visual field and a test-retest reliability study. METHODS: MfVEP was recorded from 26 healthy volunteers. RESULTS: Two response components could be clearly identified. The latencies corresponded to those of the traditional VEP response (N75 and P100). The visual field was divided into 12 sectors. A characteristic pattern was obtained. Component I was mainly negative in the upper sectors and positive in the lower sectors. Component II was positive in the upper sectors and negative in the lower ones. Most of the sectors with missing responses were the ones adjacent to the horizontal meridian, corresponding to the phase reversals. In a test-retest reliability study, the amplitude and latency measurements of the second test were plotted against those of the first test. Correlation coefficients between 0.84 and 0.93 were obtained. CONCLUSIONS: The mfVEP allows a reliable quantification of two response components from small parts of the visual field. SIGNIFICANCE: This paper suggests that mfVEP could be a valuable supplement to the traditional VEP for exploring restricted parts of the visual pathways.

Adult↗
PubMed2004

The cortical representation of foveal stimuli: evidence from quadrantanopia and TMS-induced suppression.

To address the extent to which the visual foveal representation is split, we examined a 29-year-old patient with a lower right quadrantanopia following surgical removal of the left occipital cortex above the calcarine sulcus and compared her performance with subjects receiving transcranial magnetic stimulation (TMS) over the occipital lobes. In a letter/digit classification task, the patient responded accurately to targets presented in the upper visual field, for all horizontal eccentricities. In the lower visual field, she failed to discriminate letters from digits when targets were presented in the right, but not the left visual field (RVF and LVF, respectively). This pattern was also true for the foveal targets, with poor performance to foveal-RVF (0.5 degrees to the right of fixation) but not foveal-LVF (0.5 degrees to the left of fixation) targets. Similar patterns of normal performance to LVF but not RVF or foveal-RVF targets were observed in a group of nine normal observers when TMS was applied over their left occipital cortex. Complementary impairments to LVF and foveal-LVF target classification were induced with TMS over the right occipital cortex. Thus, we have induced an hemianopic pattern in normal observers contralateral to the magnetically stimulated hemisphere. This correspondence between real and TMS-induced visual field defects is further evidence, in neurologically intact subjects, that the cortical representation of the fovea is split between the two hemispheres along the vertical meridian.

Adult↗
PubMed2004

Retinotopic organization of visual mental images as revealed by functional magnetic resonance imaging.

In this study, we used event-related functional magnetic resonance imaging to investigate whether visual mental images retinotopically activate early visual cortex. Six participants were instructed to visualize or view horizontally or vertically oriented flashing bow-tie shaped stimuli. When compared to baseline, imagery globally activated Area V1. When the activation evoked by the stimuli at the different orientations was directly compared, distinct spatial activation patterns were obtained for each orientation in most participants. Not only was the topography of the activation patterns from imagery similar to the topography obtained with a corresponding visual perception task, but it closely matched the individual cortical representation of either the horizontal or the vertical visual field meridians. These findings strongly support that visual imagery and perception share low-level anatomical substrate and functional processes. Binding of spatial features is suggested as one possible mechanism.

Acoustic Stimulation↗
PubMed2005

Jet lag and air travel: implications for performance.

This review focuses on travel stress in athletes. An outline of the circadian system is presented, followed by an explanation of how disturbances to its regulation are related to jet lag. There are consequences of jet lag that affect exercise performance and health. Measures to ameliorate adverse effects of jet lag include behavioral or pharmacologic strategies. Coaches and mentors and the athletes they support should be considered when preparing for long-haul flights across multiple meridians.

Aircraft↗
PubMed2005

Usefulness and influence of age of a novel rapid monoclonal enzyme immunoassay stool antigen for the diagnosis of Helicobacter pylori infection in children.

A novel rapid monoclonal enzyme immunoassay stool antigen for Helicobacter pylori detection (Immunocard STAT!HpSA, Meridian Diagnostic Inc , Cincinnati, OH) was evaluated in 29 infected and 99 noninfected children. The overall sensitivity, specificity, and positive and negative predictive values were 86.2%, 92.9%, 78.1%, and 95.8%, respectively, with an accuracy of 91.4%. The highest performance was observed in children older that 10 years, with a sensitivity level of 100%, contrasting with a lower level, 75%, in those younger than 5 years. A good negative predictive value was observed in all age groups, particularly in older children achieving 100%.

Adolescent↗
PubMed2004

Diagnosis of Helicobacter pylori infection in dyspeptic patients by stool antigen detection usefulness of a new monoclonal enzyme immunoassay test.

BACKGROUND: Helicobacter pylori antigens can be measured in human stools with an enzyme immunoassay, which may prove to be a valuable non-invasive diagnostic tool. Aim. To evaluate the usefulness of a new monoclonal enzyme immunoassay for detecting H. pylori antigens in dyspeptic patients' faeces (FemtoLab H. pylori, Connex, Martinsried, Germany). PATIENTS: H. pylori infection was determined in 75 patients (49 men, 26 women, mean age 52 + 16.5) for histology and rapid urease test. METHODS: H. pylori status was established by concordance of the reference tests. FemtoLab H. pylori was measured in triplicate. In addition, two determinations of a polyclonal faecal antigen test (HpSA, Platinum Premier HpSA, Meridian Diagnostic Inc., Cincinnati, USA) were also performed. Sensitivity, specificity, positive and negative predictive values were calculated. Concordance between different measurements was estimated by Kappa statistics. RESULTS: The sensitivity of the FemtoLab H. pylori immunoassay ranged from 98 to 100% and its specificity was 76%. Positive and negative predictive values were 91 and 94-100%, respectively. Concordance coefficients ranged from 0.81 to 0.92. Corresponding HpSA values were 69, 86, 92 and 53%, respectively. Concordance coefficient was 0.61. CONCLUSIONS: FemtoLab H. pylori is a very sensitive, specific, highly reproducible and easy-to-perform tool for diagnosis of H. pylori infection.

Adolescent↗
PubMed2005

Quantifying rod photoreceptor-mediated vision in retinal degenerations: dark-adapted thresholds as outcome measures.

Pre-clinical trials of treatment in retinal degenerations have shown progress toward preventing loss or restoring function of rod photoreceptors. In anticipation of human clinical trials, we assessed two psychophysical methods of quantifying rod photoreceptor-mediated function as potential outcome measures. Modified automated perimeters were used to deliver focal or full-field light stimuli and dark-adapted thresholds were measured. Patients with retinal degeneration were studied in two experimental protocols. Experiment 1 (n = 35 patients) studied dark-adapted focal chromatic stimuli in central retinal locations along the horizontal meridian. Experiment 2 (n = 146 patients) studied dark-adapted responses to a full-field stimulus test (FST) using white and chromatic stimuli. Patients in both experimental groups had testing on two different visits to determine inter-visit variability. In Experiment 1, two subgroups of patients were identified: a group with a majority of test loci detected by rod photoreceptors and a group with only cone-mediated detection. Inter-visit variability (95% confidence interval) was +/-3.1 dB for normals, +/-3.0 dB for patients with rod-mediated function and +/-2.8 dB for patients with only cone-mediated function. In Experiment 2, the dynamic range of the FST using white stimuli was sufficient to quantify sensitivity in all patients studied, including those with severe retinal degenerations. Chromatic stimuli in the FST were detectable by 85% of patients and rod- or cone-mediation could be determined. Regional retinal sources of FST were explored by comparing FST and dark-adapted perimetry in the same patients; there was a strong correlation between FST level and the loci with highest sensitivity by perimetry. Inter-visit variability (95% confidence interval) in the patients was +/-3.9 dB compared to +/-3.5 dB in normals. Dark-adapted focal threshold measurements with an abbreviated protocol in retinal degeneration patients with stable fixation may be useful as an outcome measure for therapies that can affect rod vision. FST measurements were feasible and reproducible in a large spectrum of retinal degenerative diseases and will be most applicable as a psychophysical outcome measure for treatment trials of very severe disorders in which fixation is lost and there is need for a large dynamic range of stimulus intensity.

Adolescent↗
PubMed2006

Myocardial contractile dysfunction contributes to the development of heart failure in rats with aortic stenosis.

OBJECTIVES: To analyze the potential contribution of contractility state and ventricular geometry to the development of heart failure in rats with aortic stenosis. METHODS: Rats were divided into three groups: compensated aortic stenosis (AS, n=11), heart failure AS (n=12) and control rats (C, n=13). RESULTS: After 21 weeks, failing AS rats presented higher systolic (C=36.6+/-3.1, AS=78.6+/-4.8*, failing AS=104.6+/-7.8*(dagger)) and diastolic meridian stress (C=6.9+/-0.4, AS=20.1+/-1.1*, failing AS=43.2+/-3.2*(dagger)), hydroxyproline (C=3.6+/-0.7 mg/g, AS=6.6+/-0.6* mg/g, failing AS=9.2+/-1.4*(dagger) mg/g) and cross-sectional area (C=338+/-25 microm2, AS=451+/-32* microm2, failing AS=508+/-36*(dagger) microm2), in comparison with control and compensated AS animals (*p<0.05 vs. control, (dagger)p<0.05 vs. AS). In the isometric contraction study, considering the time from peak tension to 50% relaxation (RT50), the relative variation responses, following post-rest contraction and increase in Ca2+ concentration, were higher in failing AS than compensated AS animals. In contrast, following post-rest contraction, compensated AS group presented higher values of the peak developed tension (DT) than failing AS group. Following beta-adrenergic stimulation, control animals presented higher values of +dT/dt and -dT/dt than AS animals. In addition, failing AS animals presented higher TPT values than compensated AS animals. CONCLUSION: Myocardial contractile dysfunction contributes to the development of heart failure in rats with aortic stenosis.

Animals↗
PubMed2006

Effects of acupressure on dysmenorrhea and skin temperature changes in college students: a non-randomized controlled trial.

BACKGROUND: Complementary and alternative therapies may be adopted as nursing interventions to alleviate dysmenorrhea and improve productivity, creativity, work performance, and quality of life. OBJECTIVES: This study aimed to evaluate the efficacy of San Yin Jiao (SP6) acupressure as a non-pharmacologic nursing intervention for dysmenorrhea and identify its effects on temperature changes in two related acupoints as an explanatory mechanism of chi circulation. DESIGN: A non-equivalent control group pre and post-test design was employed to verify the effects of SP6 acupressure on skin temperature and dysmenorrhea. SETTING AND PARTICIPANTS: Young college women with primary dysmenorrhea were recruited from classrooms at two universities in Korea and 58 eligible participants were allotted to either a SP6 acupressure group or placebo group that received light touch on the SP6 acupoint. METHODS: The experimental group received acupressure treatment within the first 8h of menstruation, and severity of dysmenorrhea and skin temperature changes in the Zhongwan (CV2) and Qugu (CV12) acupoints were assessed prior to and 30 min, 1, 2, and 3h following treatment. RESULTS: There was a significant difference in severity of dysmenorrhea between the two groups immediately after (F=18.50, p=0.000) and for up to 2h (F=8.04, p=0.032) post treatment. Skin temperature was significantly elevated at 30 min after acupressure at the suprapubic CV2 acupoint in the experimental group compared to the control group. Temperature elevation was also noted at the epigastric CV12 acupoint post treatment but group differences were not significant, indicating that SP6 acupressure relieves dysmenorrhea primarily by temperature elevation in the CV2 pathway. CONCLUSIONS: Acupressure to the SP6 meridian can be an effective non-invasive nursing intervention for alleviation of primary dysmenorrhea, with effects lasting 2h post treatment.

Acupressure↗
PubMed2004

Anterior chamber angle biometry with ultrasound biomicroscopy after diode laser thermal keratoplasty.

PURPOSE: To evaluate the effect of diode laser thermal keratoplasty (DTK) on the geometry of the anterior chamber angle with ultrasound biomicroscopy (UBM). SETTING: Department of Ophthalmology and Optometry, Paracelsus Private Medical University, Salzburg, Austria. METHODS: In 9 eyes, a Rodenstock DTK (ProLaser Medical Systems) was used to correct hyperopia (n = 6) or hyperopic astigmatism (n = 3). Hyperopia was treated with a single- or double-ring pattern and hyperopic astigmatism, with additional spots in each of the flat half meridians. Ultrasound biomicroscopy measurements of the chamber angle were obtained preoperatively and 3 months postoperatively using a Humphrey UBM 840 system with a 50 MHz transducer. Quantitative measurements were performed at 3-, 6-, 9-, and 12-o'clock positions using a standardized method. RESULTS: No statistically significant differences between the preoperative and postoperative chamber angle measurements were detected. CONCLUSIONS: The results of the UMB measurements were surprising given the flattening of the corneal periphery found by computerized topography, a finding that suggests narrowing of the chamber angle. Shortening of the corneal tissue may result in centripetal traction that affects the trabecular meshwork and results in a relative opening of the chamber angle structures.

Adult↗