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Conjunctivitis caused by Thelazia callipaeda infestation in a woman.

Thelazia is a nematode (Spirurida) that can parasitize the mammalian conjunctival sac. This is the first reported case of ocular. Thelazia callipaeda infestation in Taiwan. A 41-year-old woman experienced swelling, itching sensation and occasional blurred vision of the right eye 2 weeks after a small group of flies swarmed her eye while she was hiking. Her symptoms were first misdiagnosed as allergic conjunctivitis at a local medical clinic. During her first visit to our outpatient department, five white thread-like living worms were discovered on the superior and inferior fornices. The worms were cream-colored, slender and approximately 1 cm in length. Follicular and papillary conjunctivitis was noted in her right eye. After removing the worms, the symptoms resolved and no other worms were found in the following 2 months. This case is a remainder to physicians that parasitic infestation should be included in the differential diagnoses of ocular itching, conjunctivities, and blurred vision after insect contact.

Adult↗

[Value of lacrymal IgE determination and conjunctival cytology in the diagnosis of chronic conjunctivitis].

PURPOSE: Chronic conjunctival inflammatory diseases may depend upon various strongly intricated mechanisms. Discriminating allergy from nonspecific inflammation has become of striking importance for diagnosis and treatment. We investigated conjunctival inflammatory response by comparing two objective biological tools, tear IgE detection and HLA DR expression by conjunctival epithelium, as indirect indicators of activation of the Th1 and Th2 subsets, respectively. METHODS: Sixty-eight patients (135 eyes) with chronic conjunctivitis underwent tear IgE dosage by an ELISA technique and quantification of HLA DR expression in impression cytology specimens. 34 had direct or indirect clinical indications of allergic mechanisms, 22 had chronic conjunctivitis without any sign of allergy, and 12 suffered from isolated nonallergic dry eyes. RESULTS: Patients clinically considered as allergic only showed positive IgE in 31 out pf 68 eyes (46 per cent), whereas 11/44 (25%) and 7/24 (29%) eyes with nonspecific conjunctivitis and dry eyes respectively were also positive. HLA DR positivity in epithelial cells was found in 18/61 (29.5%), 15/40 (37.5%) and 9/22 (41%) eyes, respectively. HLA DR expression by epithelial cells was negatively correlated with tear IgE, as most specimens positive to one criterion were negative to the other one (37 eyes DR+ IgE-, 35 eyes DR- IgE+, and 5 eyes DR+ IgE+; chi-square: p = 0.0001). CONCLUSION: As IgE synthesis and HLA DR induction may represent indirect indicators of the activation of the Th1 and Th2 subsets, association of these two simple tests could be interesting for the routine assessment of the mechanisms of inflammatory ocular surface diseases.

Adult↗

Acute hemorrhagic conjunctivitis--St. Croix, U.S. Virgin Islands, September-October 1998.

Hurricane Georges struck the U.S. Virgin Islands on September 21, 1998. Immediately thereafter, health authorities on St. Croix (1998 population: approximately 50,000) became aware of increased numbers of cases of conjunctivitis. During September, one of the two public health clinics on the island recorded 88 cases of conjunctivitis, compared with three cases during August. Cases were characterized by periorbital swelling, excessive lacrimation, conjunctival redness with occasional hemorrhages, and foreign-body sensation in the eye. No severe sequelae were reported. Local ophthalmologists considered the symptoms characteristic of viral acute hemorrhagic conjunctivitis (AHC). This report describes the initial findings of an ongoing clinical, epidemiologic, and laboratory investigation of this outbreak.

Acute Disease↗

[Conjunctivitis, episcleritis and scleritis].

Conjunctivitis, episcleritis and scleritis are inflammation of external part of the eye ball. All these disease induce "red eyes". Some of these inflammation are potentially severe. Visual function can be involved. Conjunctivitis, episcleritis and scleritis can also be the first location of a severe systemic disease.

Adrenal Cortex Hormones↗

Diagnosis of allergic conjunctivitis.

Itching was cited as a major symptom of their ocular disease by 49 (80%) of the 61 patients with allergic conjunctivitis. Conjunctival scrapings from 51 patients (84%) demonstrated intact eosinophils or eosinophil granules. Eosinophil granules were a useful and recognizable cytologic feature of allergic conjunctivitis even in the absence of intact eosinophils. We believe that a history of itching and the presence of eosinophils or eosinophil granules in conjunctival scrapings are helpful in diagnosing allergic conjunctivitis.

Conjunctiva↗

Causal attribution as a search for underlying mechanisms: an explanation of the conjunction fallacy and the discounting principle.

We propose that causal attribution involves searching for underlying mechanism information (i.e., the processes underlying the relationship between the cause and the effect). This processing account can explain both the conjunction effect (i.e., conjunctive explanations being rated more probable than their components) and the discounting effect (i.e., the effect of one cause being discounted when another cause is already known to be true). When two explanations cohere with respect to a single mechanism, they would be judged to be more likely than a single explanation which partly supports that mechanism. When the two explanations imply two separate mechanisms, one would be discounted. In Experiment 1, both effects occurred with mechanism-based explanations but not with covariation-based explanations in which the cause-effect relationship was phrased in terms of statistical covariations without referring to mechanisms. In Experiments 2 and 3, the amount of the discounting and conjunction effects varied depending on the relationships between specific mechanisms in the two given explanations. We discuss why the current results pose difficulties for previous attribution models.

Causality↗

Division of inputs between hemispheres eliminates illusory conjunctions.

We demonstrate that division of inputs between the hemispheres does not just generally improve performance but specifically reduces inter-item perceptual interference relative to single hemisphere presentation. Subjects verified the presence of colored letter targets in briefly presented letter pairs presented to the same (unihemispheric condition) or different (bihemispheric condition) sides of space. Four experiments showed consistently that although illusory conjunctions (i.e. perceptual miscombinations of stimulus features) occurred commonly during unihemispheric presentations, they never occurred during bihemispheric presentations, even though accuracy of detecting individual stimulus features was held constant across the conditions. Increasing inter-item similarity resulted in a general interference effect based in discrimination difficulty that was sufficient to eliminate illusory conjunctions even in the unihemispheric condition. However, when inter-item interference was manipulated using perceptual grouping by movement the bihemispheric illusory conjunction advantage increased with increasing interference. Our findings suggest that the two cerebral hemispheres can operate as relatively independent work stations during visual perceptual processing, thereby maximizing the efficiency of information processing.

Adult↗

Parallel search for a conjunction of contrast polarity and shape.

When a target object embedded in an array of other objects can be distinguished along a single feature dimension (e.g. color or shape), it can be detected in parallel. When a target object is defined by a conjunction of stimulus features, at least some serial search is required, indicating that the visual system is less efficient in conducting a parallel search over two stimulus dimensions simultaneously. Some exceptions to this finding have been reported. The present results suggest another exception: search for a conjunction of contrast polarity and shape can be conducted in parallel while the same conjunction consisting of color and shape requires some serial search. The neurophysiological implications are discussed.

Color Perception↗

Preattentive representation of feature conjunctions for concurrent spatially distributed auditory objects.

The role of attention in conjoining features of an object has been a topic of much debate. Studies using the mismatch negativity (MMN), an index of detecting acoustic deviance, suggested that the conjunctions of auditory features are preattentively represented in the brain. These studies, however, used sequentially presented sounds and thus are not directly comparable with visual studies of feature integration. Therefore, the current study presented an array of spatially distributed sounds to determine whether the auditory features of concurrent sounds are correctly conjoined without focal attention directed to the sounds. Two types of sounds differing from each other in timbre and pitch were repeatedly presented together while subjects were engaged in a visual n-back working-memory task and ignored the sounds. Occasional reversals of the frequent pitch-timbre combinations elicited MMNs of a very similar amplitude and latency irrespective of the task load. This result suggested preattentive integration of auditory features. However, performance in a subsequent target-search task with the same stimuli indicated the occurrence of illusory conjunctions. The discrepancy between the results obtained with and without focal attention suggests that illusory conjunctions may occur during voluntary access to the preattentively encoded object representations.

Acoustic Stimulation↗

The fast detection of rare auditory feature conjunctions in the human brain as revealed by cortical gamma-band electroencephalogram.

Natural environments typically contain temporal scatters of sounds emitted from multiple sources. The sounds may often physically stand out from one another in their conjoined rather than simple features. This poses a particular challenge for the brain to detect which of these sounds are rare and, therefore, potentially important for survival. We recorded gamma-band (32-40 Hz) electroencephalographic (EEG) oscillations from the scalp of adult humans who passively listened to a repeated tone carrying frequent and rare conjunctions of its frequency and intensity. EEG oscillations that this tone induced, rather than evoked, differed in amplitude between the two conjunction types within the 56-ms analysis window from tone onset. Our finding suggests that, perhaps with the support of its non-phase-locked synchrony in the gamma band, the human brain is able to detect rare sounds as feature conjunctions very rapidly.

Acoustic Stimulation↗

The role of the Genial Bone Advancement Trephine system in conjunction with uvulopalatopharyngoplasty in the multilevel management of obstructive sleep apnea.

OBJECTIVES: The successful surgical management of obstructive sleep apnea (OSA) requires surgical procedures that address both retropalatal and retrolingual airway obstruction. The Genial Bone Advancement Trephine (GBAT) system is a new, 1-step system that allows for isolation and advancement of the genioglossus muscle via a guided trephine system. The purpose of this project was to describe our experience using the GBAT system to perform genioglossus advancement (GGA) in conjunction with uvulopalatopharyngoplasty (UPPP) in the surgical management of OSA. STUDY DESIGN: Retrospective analysis of 35 consecutive patients undergoing GGA using the GBAT system in conjunction with UPPP for the management of OSA during a 3-year period (1999 to 2002). RESULTS: Twenty-four patients had complete preoperative and postoperative polysomnographic data. A 70% reduction in the Respiratory Disturbance Index (RDI) and Apnea Index (AI) in the preoperative versus postoperative PSG (RDI, 52.9 +/- 17.1 versus 15.9 +/- 7.5; AI, 20.1 +/- 6.7 versus 6.1 +/- 4.5; P < or = 0.0001). The lowest oxygen desaturation increased from 80% to 88% (P = 0.0002), and the posterior airway increased from 7.9 to 12.6 mm (P < 0.0001). With a surgical cure defined as a greater than 50% reduction in the RDI and a final postoperative RDI of less than 20 events per hour, the true surgical cure rate was 67% (16 of 24 patients). CONCLUSIONS: The GBAT system performed in conjunction with UPPP can produce significant reductions in RDI and AI while improving the oxygen desaturation and enlarging the posterior airway space. The effective cure rates using the GBAT system are in agreement with previous reports in the literature using various GGA techniques. The GBAT may have some advantages in terms of simplicity and safety.

Adult↗

Attention speeds processing across eccentricity: feature and conjunction searches.

We investigated whether the effect of covert attention on information accrual varies with eccentricity (4 degrees vs 9 degrees) and the complexity of the visual search task (feature vs conjunction). We used speed-accuracy tradeoff procedures to derive conjoint measures of the speed of information processing and accuracy in each search task. Information processing was slower with more complex conjunction searches than with simpler feature searches, and overall it was faster at peripheral (9 degrees) than parafoveal (4 degrees) locations in both search types. Covert attention increased discriminability and accelerated information accrual at both eccentricities, and the magnitude of this attentional effect was the same for both feature (simple) and conjunction (complex) searches. Interestingly, in contrast to the compensatory effect of covert attention on information processing at iso-eccentric locations (temporal performance fields), covert attention did not eliminate speed differences across eccentricity.

Attention↗

The role of priming in conjunctive visual search.

To assess the role of priming in conjunctive visual search tasks, we systematically varied the consistency of the target and distractor identity between different conditions. Search was fastest in the standard conjunctive search paradigm where identities remained constant. Search was slowest when potential target identity varied predictably for each successive trial (the 'switch' condition). The role of priming was also demonstrated on a trial-by-trial basis in a 'streak' condition where target and distractor identity was unpredictable yet was consistent within streaks. When the target to be found was the same for a few trials in a row, search performance became similar to that when the potential target was the same on all trials. A similar pattern was found for the target absent trials, suggesting that priming is based on the whole search array rather than just the target in each case. Further analysis indicated that the effects of priming are sufficiently strong to account for the advantage seen for the conjunctive search task. We conclude that the role of priming in visual search is underestimated in current theories of visual search and that differences in search times often attributed to top-down guidance may instead reflect the benefits of priming.

Attention↗

Independent processing of changes in auditory single features and feature conjunctions in humans as indexed by the mismatch negativity.

The mismatch negativity (MMN), an event-related potential component of the EEG, is elicited by violations of auditory regularities In the present study, the stimulus blocks contained two types of standard tones, differing from each other in frequency and intensity. MMNs were recorded to three different types of deviant stimuli: (a) feature deviants, differing from standards in their perceived locus of origin; (b) conjunction deviants, having the frequency of one of the standards and the intensity of the other; (c) double deviants, differing from standards in both (a) and (b). The MMN to double deviants was similar to the sum of the MMNs to feature and conjunction deviants. This result indicates that changes in simple stimulus features and conjunction of features are processed independently by the automatic sound change detection system indexed by MMN.

Adult↗

The effect of gonadotrophin releasing hormone and follicle stimulating hormone in conjunction with pregnant mare serum gonadotrophin on the superovulatory response in crossbred sheep in India.

Thirty-two mature crossbred (Fine Wool Synthetic, FWS) sheep developed for fine wool production in India were treated for superovulation and oestrus synchronization in spring season. The ewes were randomly allocated to four treatment groups in a factorially designed experiment. For induction of superovulation, pregnant mare serum gonadotrophin (PMSG) was administered alone (group 1), in combination with gonadotrophin releasing hormone (GnRH) (group 2) or with follicle stimulating hormone (FSH) (group 3) and with both (group 4). Oestrus was synchronized in all the ewes by two injections of prostaglandin F2 alpha (PGF, 10 mg each) administered at an interval of 10 days. Superovulation treatment started 48 h prior to the second PGF injection. The proportion of ewes in oestrus did not differ significantly (p > 0.05) in the four groups. The use of GnRH set the ewes into oestrus earlier than the ewes in the other groups. Treatment with PMSG (800 IU) in conjunction with 4 micrograms of Buserilin (GnRH) increased the ovulation rate (9.1 +/- 2.6 corpora lutea (CL)) above that observed when PMSG was used alone (3.0 +/- 0.7 CL). The use of FSH (0.5 U ovagen) in conjunction with PMSG was characterized by a decrease in the proportion of ewes with < or = 2 CL (4/8 vs 7/8; p < 0.05) and in the number of ovulations, i.e. CL observed (2.4 +/- 0.6 vs 9.1 +/- 2.6), and a nonsignificant increase in the incidence of large follicles (LF) (4.6 +/- 1.28 vs 3.25 +/- 0.6; p > 0.05). The interaction between treatments of FSH and GnRH was not significant (p > 0.05). It is concluded that use of GnRH, in conjunction with either PMSG alone or PMSG plus FSH treatment, advanced the onset of oestrus and increased the ovulation rate in FWS sheep.

Animals↗

Conjunctive moderator variables in vulnerability and resiliency research: life stress, social support and coping skills, and adolescent sport injuries.

In life event research relating to vulnerability and resilience factors, single moderator variables have typically been the focus of study. Little is known about the ways in which moderator variables may interact with one another to increase vulnerability or resilience. We propose a distinction between conjunctive moderation, in which multiple moderators must co-occur in a specific combination or pattern to maximize a relation between a predictor and an outcome variable, and disjunctive moderation, in which any one of a number of moderators maximizes the predictor-criterion relation. Our results indicate that social support and psychological coping skills are statistically independent psychosocial resources and that they operate in a conjunctive manner to influence the relation between life stress and subsequent athletic injury in adolescents. Only athletes low in both coping skills and social support exhibited a significant stress-injury relation, and in that vulnerable subgroup, negative major life events accounted for up to 30% of the injury variance. Methodological considerations in the assessment of conjunctive moderator effects are discussed.

Adaptation, Psychological↗

Impression valence constrains social explanations: the case of discounting versus conjunction effects.

Discounting refers to a reduction in explanation plausibility in light of another explanation, whereas conjunction effects refer to an increase in plausibility of explanations judged in combination rather than in isolation. Explanation compatibility moderates these effects, such that discounting is greater for incompatible explanations and conjunction effects are greater for compatible explanations. Three experiments examined whether this effect reflects perceptions regarding (a) the prior statistical association of causal factors, (b) the sharing of common causal mechanisms, or (c) coherence with regard to global impressions. Results indicated that impression valence predicts and also directly influences discounting and conjunction effects independent of covariation and mechanism, underscoring the pervasive impact of impressions on attributions.

Adult↗

Is meaning implicated in illusory conjunctions?

According to feature-integration theory, when attention is diverted from a display, features from different objects in that display may be wrongly recombined, giving rise to "illusory conjunctions" (Treisman & Schmidt, 1982). Two experiments are reported that examine the nature of these illusory conjunctions. In displays that contain color names and adjectives printed in colored ink, subjects made two kinds of interesting and previously unreported errors. Consider, for example, a display that included the word BROWN in red ink and the word HEAVY in green ink. Subjects would sometimes incorrectly report that the word RED or the ink color brown had appeared in the display (e.g., RED in green ink or HEAVY in brown ink). It appears that subjects extract semantic representations from input and are sometimes confused about whether a particular representation has been extracted from a word or a color patch. Contrary to feature-integration theory, these findings suggest that illusory conjunctions may occur with high-level codes as well as with perceptual features.

Color Perception↗