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Biomedical subjects

T R Jordan

Publications and source records attributed to T R Jordan.

18 recordsLinked to original sources

[Clinical symptoms and mediators in the allergic early and late phase reaction].

BACKGROUND: This examination focused on the allergic early and late phase reaction via nasal symptom scores, acoustic rhinometry, and the determination of mediators possibly involved in late phase eosinophilia. We examined nasal secretions for IL-5; the chemokines IL-8, MCP-1, and Eotaxin; the adhesion molecule sVCAM-1, and the leukotriene LTC4 for their suggested impacts on tissue eosinophilia. METHODS: 13 patients suffering from seasonal allergic rhinitis were challenged intranasally out of the natural pollen season by their specific allergen. In a time window of 8 h following the provocation, patients completed symptom questionnaires, and underwent acoustic rhinometry. Nasal secretions were gained by the cotton wool method over a time period of 8 h. Nasal secretions were analyzed for the above mentioned mediators. RESULTS: Individual evaluation of the acoustic rhinometry measurements revealed an early phase reaction in 100 % of the cases and a late phase reaction in 92 %. The need to sneeze and a runny nose were the strongest symptoms during the allergic early and late phase reaction. A typical late phase kinetic was observed for IL-5, MCP-1, Eotaxin, sVCAM-1, and LTC4. IL-8 was characteristic for early phase reaction but increased in late phase as well. CONCLUSIONS: The need to sneeze, a runny nose, and the overall quality of life were most apt to evaluate the allergic early and late phase reaction. Highly significant correlations between nasal obstruction and acoustic rhinometry measurements indicate a high sensitivity of visual analogue scales in the representation of minimal changes in nasal symptom scores during the allergic reaction. Our data point to a relevant role of the TH2 cytokine IL-5; of the chemokines IL-8, MCP-1, and Eotaxin; of the adhesion molecule sVCAM-1, and of the leukotriene LTC4 for the allergic late phase eosinophilia.

Adult↗

[Humoral mucosal immunity in allergic rhinitis].

BACKGROUND: Mucosa-immunologic aspects are gaining an increasing awareness in the pathophysiology of type I allergies. Humoral mucosal immune responses are dominated by secretory IgA, but there is evidence for a relevant role of IgG in nasal mucosa-associated lymphoid tissue. OBJECTIVE: was to measure allergen-specific immunoglobulins (IgA and IgG) in nasal secretions as an expression of a humoral mucosal immune response in allergic rhinitis. For tissue eosinophilia we studied nasal Eosinophilic Cationic Protein (ECP) and for mast cell activation nasal tryptase. METHODS: Nasal secretions of 40 patients suffering from allergic rhinitis were analyzed for allergen-specific IgA, IgG, and IgE, and for ECP and tryptase. Patients were highly sensitized against the major allergens of house dust mites, timothy, and birch pollen. 43 non-atopic individuals served as controls. In order to study possible effects of the actual pollen season on the studied parameter we secondly compared patients allergic to seasonal allergens co- (n = 28) and extra-seasonally (n = 41). In order to determine a possible influence of allergen-specific IgA in eosinophilic degranulation we additionally studied 5 patients after nasal allergen challenge. RESULTS: In allergic rhinitis we found significantly increased levels of allergen-specific immunoglobulins of all studied subclasses and allergens in nasal secretions. Comparison of nasal ECP and tryptase showed significantly increased concentrations in allergic individuals as well. Co-seasonally we found elevated allergen-specific IgE, ECP, and tryptase but lower concentrations of allergen-specific IgA and IgG. There was no association between late phase eosinophilia and IgA concentrations after local allergen challenge. CONCLUSIONS: The occurrence of allergen-specific immunoglobulins in nasal secretions is interpreted as a local humoral mucosal immune response. The physiologic role of local allergen-specific immunoglobulins is not clear to date. Involvement in degranulation of eosinophils or mast cells, like suggested before, seems unlikely.

Adult↗

Techniques for the production of point-light and fully illuminated video displays from identical recordings.

Illumination of only a few key points on a moving human body or face is enough to convey a compelling perception of human motion. A full understanding of the perception of biological motion from point-light displays requires accurate comparison with the perception of motion in normal, fully illuminated versions of the same images. Traditionally, these two types of stimuli (point-light and fully illuminated) have been filmed separately, allowing the introduction of uncontrolled variation across recordings. This is undesirable for accurate comparison of perceptual performance across the two types of display. This article describes simple techniques, using proprietary software, that allow production of point-light and fully illuminated video displays from identical recordings. These techniques are potentially useful for many studies of motion perception, by permitting precise comparison of perceptual performances across point-light displays and their fully illuminated counterparts with accuracy and comparative ease.

Computer Terminals↗

How physician assistants use and perceive complementary and alternative medicine.

The use of complementary and alternative medicine (CAM) is growing in the United States. Patients and their health care providers are increasingly accepting of complementary and alternative therapies. The purpose of this study was to identify physician assistants' (PAs') attitudes, beliefs, knowledge, training, recommendations for, and personal use of CAM. A random sample of 500 practicing PAs was sent a four-page, 78-item survey investigating their personal use of, recommendations for, and perceptions of the efficacy and safety of complementary and alternative therapies. Of PAs eligible to complete the survey, 50% responded. Chi-square analyses found a significant relationship between knowledge level and recommendation for CAM; status of use and belief that CAM exerts a placebo effect; status of use and recommendation for CAM; and source of information on CAM and recommendation for CAM. With the increasing prevalence of use of CAM, PAs need to be informed regarding CAM therapies.

Adult↗

Effects of horizontal viewing angle on visual and audiovisual speech recognition.

The authors investigated the effects of changes in horizontal viewing angle on visual and audiovisual speech recognition in 4 experiments, using a talker's face viewed full face, three quarters, and in profile. When only experimental items were shown (Experiments 1 and 2), identification of unimodal visual speech and visual speech influences on congruent and incongruent auditory speech were unaffected by viewing angle changes. However, when experimental items were intermingled with distractor items (Experiments 3 and 4), identification of unimodal visual speech decreased with profile views, whereas visual speech influences on congruent and incongruent auditory speech remained unaffected by viewing angle changes. These findings indicate that audiovisual speech recognition withstands substantial changes in horizontal viewing angle, but explicit identification of visual speech is less robust. Implications of this distinction for understanding the processes underlying visual and audiovisual speech recognition are discussed.

Humans↗

Lateralized word recognition: assessing the role of hemispheric specialization, modes of lexical access, and perceptual asymmetry.

The processing advantage for words in the right visual field (RVF) has often been assigned to parallel orthographic analysis by the left hemisphere and sequential by the right. The authors investigated this notion using the Reicher-Wheeler task to suppress influences of guesswork and an eye-tracker to ensure central fixation. RVF advantages obtained for all serial positions and identical U-shaped serial-position curves obtained for both visual fields (Experiments 1-4). These findings were not influenced by lexical constraint (Experiment 2) and were obtained with masked and nonmasked displays (Experiment 3). Moreover, words and nonwords produced similar serial-position effects in each field, but only RVF stimuli produced a word-nonword effect (Experiment 4). These findings support the notion that left-hemisphere function underlies the RVF advantage but not the notion that each hemisphere uses a different mode of orthographic analysis.

Brain↗

Rural parents' communication with their teen-agers about sexual issues.

This survey assessed rural parents' (n = 374) perceptions of the characteristics, content, and comfort level of discussions about sexual issues with their teens. Almost all parents (94%) reported they had talked with their teens about sex. Two-thirds (65%) reported being comfortable talking with their teens about sexual issues. From a list of 17 potential topical areas in sexual communication, parents were most likely to discuss with their teens the responsibilities of being a parent (46%), sexually transmitted diseases (40%), dating behavior (37%), and not having sex until marriage (36%). Most parents (80%) believed that the majority of sexuality education should be provided by the family and supplemented by outside organizations, preferably schools. Almost all parents (92%) believed sexuality education should include information on birth control methods including condoms. Almost two of three parents (64%) believed schools should begin teaching sexuality education before students reach seventh grade. Parents (52%) claimed they could best be helped in communicating with their teens by receiving a regular newsletter regarding teen sexual issues.

Adolescent↗

A low-cost, accurate method of producing large quantities of digitally filtered images.

We demonstrate how to produce complex image transformations of bitmap files for vision experiments using the Cogimatic Vision Starter Kit (VSK) library of mathematical routines along with Visual Basic, C++, or the Delphi Pascal compiler. Implementing this system on an IBM-compatible PC running Windows 95, 98, or NT4 enables researchers to quickly and economically manipulate images for vision research. The VSK includes a simple stand-alone image-processing application. In addition, VSK has the ability to automate image transformations and to fully integrate image processing into new experimental software on the PC platform.

Costs and Cost Analysis↗

Visual and audiovisual speech perception with color and gray-scale facial images.

Research has shown that auditory speech recognition is influenced by the appearance of a talker's face, but the actual nature of this visual information has yet to be established. Here, we report three experiments that investigated visual and audiovisual speech recognition using color, gray-scale, and point-light talking faces (which allowed comparison with the influence of isolated kinematic information). Auditory and visual forms of the syllables /ba/, /bi/, /ga/, /gi/, /va/, and /vi/ were used to produce auditory, visual, congruent, and incongruent audiovisual speech stimuli. Visual speech identification and visual influences on identifying the auditory components of congruent and incongruent audiovisual speech were identical for color and gray-scale faces and were much greater than for point-light faces. These results indicate that luminance, rather than color, underlies visual and audiovisual speech perception and that this information is more than the kinematic information provided by point-light faces. Implications for processing visual and audiovisual speech are discussed.

Adolescent↗

The validity of male patients' self-reports regarding prostate cancer screening.

BACKGROUND: Despite the high rate of prostate cancer screening, the accuracy of male patients' self-reports of screening has not been investigated. This study assessed the concordance between patients' self-reports of prostate screening and the medical record. METHODS: Focus groups were conducted to obtain male patients' perceptions of prostate cancer screening and salient terminology. A sample of males (n = 276), 40 years of age or older, completed a 15-item questionnaire. Patients' self-reports of PSA and DRE screening were then compared with medical records. RESULTS: Results showed that patients' self-reports of DRE and PSA were discordant with the medical record 32 and 29% of the time, respectively. Sensitivity of patients' self-reports for DRE and PSA was 82 and 74%, respectively. Specificity of patients' self-reports for DRE and PSA was 56 and 65%, respectively. One in five patients reported that they were not sure how a doctor checks a man's prostate gland. Only 39% of patients knew that the prostate gland can be checked by a blood test. CONCLUSIONS: There were significant differences between patients' self-reports and the medical record. The results should be of concern to primary care practitioners and to those who evaluate the efficacy of prostate cancer screening programs.

Adult↗

Central fixations are inadequately controlled by instructions alone: implications for studying cerebral asymmetry.

A fundamental concern when using visual presentations to study cerebral asymmetry is to ensure that stimuli are presented with the same degree of retinal eccentricity from a central fixation point in either visual field. However, a widely used procedure intended to control fixation location merely instructs participants to fixate appropriately without any other means of ensuring that central fixations actually occur. We assessed the validity of assuming that instructions alone ensure central fixation by using the traditional RVF advantage for words and either (a) only instruction to fixate centrally, or (b) eye-tracking device that ensured central fixation on every trial. Experiments 1 and 2 found that when only instructions were given, the vast majority of fixations were not central, and more occurred to the right of centre than to the left. Moreover, the prevalence of non-central fixations was otherwise disguised by the finding that both fixation procedures produced similar RVF advantages in overt performance. The impact of typical non-central fixations on performance was revealed by systematically manipulating fixation location in Experiment 3, where deviations in fixation of only 0.25 degrees from centre had a reliable impact on visual field effects. Implications of these findings for studies of cerebral asymmetry are discussed.

Adult↗

Junior high school students' perceptions regarding nonconsensual sexual behavior.

This study assessed early adolescents' attitudes and perceptions regarding nonconsensual sexual activity. A total of 371 surveys (94% return rate) was completed. More than one-third of respondents (35%) reported they had engaged in sexual intercourse; 17% reported having been sexually coerced by a teen-ager; 19% reported feeling pressure from their friends to have intercourse; 7% reported having been sexually coerced by an adult; and 6% reported having sexually coerced someone else. Students also demonstrated lack of knowledge regarding nonconsensual sexual behaviors. Analysis of variance tests determined if knowledge (KN), attitudes (AT), behavioral intentions (BI), and locus of control (LC) changed across specific background and demographic variables. One background variable (having been sexually coerced by a teen-ager) was associated with high risk orientation (lower scores) on all four subscales. Lower scores also were associated with being male (KN, AT, BI), having sexually coerced someone else (KN, AT, BI), having been sexually coerced by an adult (AT, BI), and having engaged in sexual intercourse (AT, BI).

Adolescent↗

Seeing and hearing rotated faces: influences of facial orientation on visual and audiovisual speech recognition.

It is well-known that facial orientation affects the processing of static facial information, but similar effects on the processing of visual speech have yet to be explored fully. Three experiments are reported in which the effects of facial orientation on visual speech processing were examined using a talking face presented at 8 orientations through 360 degrees. Auditory and visual forms of the syllables /ba/, /bi/, /ga/, /gi/, /ma/, /mi/, /ta/, and /ti/ were used to produce the following speech stimulus types: auditory, visual, congruent audiovisual, and incongruent audiovisual. Facial orientation did not affect identification of visual speed per se or the near-perfect accuracy of auditory speech report with congruent audiovisual speech stimuli. However, facial orientation did affect the accuracy of auditory speech report with incongruent audiovisual speech stimuli. Moreover, the nature of this effect depended on the type of incongruent visual speech used. Implications for the processing of visual and audiovisual speech are discussed.

Acoustic Stimulation↗

Word superiority over isolated letters: the neglected case of forward masking.

Previous research shows that when briefly presented alphabetic stimuli are followed by pattern masks, letters in words are reported more accurately than are isolated letters (the "Word-Letter Phenomenon," or WLP); however, when these masks are replaced by blank fields, the WLP disappears. These findings have led to the popular notion that the WLP reflects selective masking of ongoing stimulus processing and so critically depends on the use of poststimulus masks. Here we report three experiments which re-examine the role of masking in the WLP by contrasting the effects of postmasked displays with the effects of premasked displays in which words and isolated letters were preceded by a pattern mask and followed by a completely blank field. Despite the critical role generally assigned to poststimulus pattern masks, similar WLPs were obtained with pre- and postmasked displays. Implications for theories of word and letter recognition are discussed.

Computer Simulation↗

Perception and action in 'visual form agnosia'.

A single case study of a patient with 'visual form agnosia' is presented. A severe visual recognition deficit was accompanied by impairments in discriminating shape, reflectance, and orientation, although visual acuity and colour vision, along with tactile recognition and intelligence, were largely preserved. Neuropsychological and behavioural investigations have indicated that the patient is able to utilize visual pattern information surprisingly well for the control of hand movements during reaching, and can even read many whole words, despite being unable to make simple discriminative judgements of shape or orientation. She seems to have no awareness of shape primitives through Gestalt grouping by similarity, continuity or symmetry. It is proposed that many of these perceptual disorders might be the combined result of (1) a selective loss of the cortical elaboration of the magnocellular visual processing stream, and (2) a selective output disconnection from a central processor of visual boundaries and shape primitives in the occipital cortex.

Adult↗