Evidence for Infant-directed Speech Preference Is Consistent Across Large-scale, Multi-site Replication and Meta-analysis

There is substantial evidence that infants prefer infant-directed speech (IDS) to adult-directed speech (ADS). The strongest evidence for this claim has come from two large-scale investigations: i) a community-augmented meta-analysis of published behavioral studies and ii) a large-scale multi-lab replication study. In this paper, we aim to improve our understanding of the IDS preference and its boundary conditions by combining and comparing these two data sources across key population and design characteristics of the underlying studies. Our analyses reveal that both the meta-analysis and multi-lab replication show moderate effect sizes (d ≈ 0.35 for each estimate) and that both of these effects persist when relevant study-level moderators are added to the models (i.e., experimental methods, infant ages, and native languages). However, while the overall effect size estimates were similar, the two sources diverged in the effects of key moderators: both infant age and experimental method predicted IDS preference in the multi-lab replication study, but showed no effect in the meta-analysis. These results demonstrate that the IDS preference generalizes across a variety of experimental conditions and sampling characteristics, while simultaneously identifying key differences in the empirical picture offered by each source individually and pinpointing areas where substantial uncertainty remains about the influence of theoretically central moderators on IDS preference. Overall, our results show how meta-analyses and multi-lab replications can be used in tandem to understand the robustness and generalizability of developmental phenomena.

Decoding the temporal dynamics of spoken word and nonword processing from EEG

The efficiency of spoken word recognition is essential for real-time communication. There is consensus that this efficiency relies on an implicit process of activating multiple word candidates that compete for recognition as the acoustic signal unfolds in real-time. However, few methods capture the neural basis of this dynamic competition on a msec-by-msec basis. This is crucial for understanding the neuroscience of language, and for understanding hearing, language and cognitive disorders in people for whom current behavioral methods are not suitable. We applied machine-learning techniques to standard EEG signals to decode which word was heard on each trial and analyzed the patterns of confusion over time. Results mirrored psycholinguistic findings: Early on, the decoder was equally likely to report the target (e.g., baggage) or a similar sounding competitor (badger), but by around 500 msec, competitors were suppressed. Follow up analyses show that this is robust across EEG systems (gel and saline), with fewer channels, and with fewer trials. Results are robust within individuals and show high reliability. This suggests a powerful and simple paradigm that can assess the neural dynamics of speech decoding, with potential applications for understanding lexical development in a variety of clinical disorders.

A multi-lab study of bilingual infants: Exploring the preference for infant-directed speech

From the earliest months of life, infants prefer listening to and learn better from infant-directed speech (IDS) than adult-directed speech (ADS). Yet, IDS differs within communities, across languages, and across cultures, both in form and in prevalence. This large-scale, multi-site study used the diversity of bilingual infant experiences to explore the impact of different types of linguistic experience on infants' IDS preference. As part of the multi-lab ManyBabies 1 project, we compared lab-matched samples of 333 bilingual and 385 monolingual infants' preference for North-American English IDS (cf. ManyBabies Consortium, 2020: ManyBabies 1), tested in 17 labs in 7 countries. Those infants were tested in two age groups: 6-9 months (the younger sample) and 12-15 months (the older sample). We found that bilingual and monolingual infants both preferred IDS to ADS, and did not differ in terms of the overall magnitude of this preference. However, amongst bilingual infants who were acquiring North-American English (NAE) as a native language, greater exposure to NAE was associated with a stronger IDS preference, extending the previous finding from ManyBabies 1 that monolinguals learning NAE as a native language showed a stronger preference than infants unexposed to NAE. Together, our findings indicate that IDS preference likely makes a similar contribution to monolingual and bilingual development, and that infants are exquisitely sensitive to the nature and frequency of different types of language input in their early environments.

The development of gaze following in monolingual and bilingual infants: A multi-laboratory study

Determining the meanings of words requires language learners to attend to what other people say. However, it behooves a young language learner to simultaneously encode relevant non-verbal cues, for example, by following the direction of their eye gaze. Sensitivity to cues such as eye gaze might be particularly important for bilingual infants, as they encounter less consistency between words and objects than monolingual infants, and do not always have access to the same word-learning heuristics (e.g., mutual exclusivity). In a preregistered study, we tested the hypothesis that bilingual experience would lead to a more pronounced ability to follow another's gaze. We used a gaze-following paradigm developed by Senju and Csibra (Current Biology, 18, 2008, 668) to test a total of 93 6- to 9-month-old and 229 12- to 15-month-old monolingual and bilingual infants, in 11 laboratories located in 8 countries. Monolingual and bilingual infants showed similar gaze-following abilities, and both groups showed age-related improvements in speed, accuracy, frequency, and duration of fixations to congruent objects. Unexpectedly, bilinguals tended to make more frequent fixations to on-screen objects, whether or not they were cued by the actor. These results suggest that gaze sensitivity is a fundamental aspect of development that is robust to variation in language exposure.

Preverbal Infants Discover Statistical Word Patterns at Similar Rates as Adults: Evidence From Neural Entrainment

The discovery of words in continuous speech is one of the first challenges faced by infants during language acquisition. This process is partially facilitated by statistical learning, the ability to discover and encode relevant patterns in the environment. Here, we used an electroencephalogram (EEG) index of neural entrainment to track 6-month-olds’ ( N = 25) segmentation of words from continuous speech. Infants’ neural entrainment to embedded words increased logarithmically over the learning period, consistent with a perceptual shift from isolated syllables to wordlike units. Moreover, infants’ neural entrainment during learning predicted postlearning behavioral measures of word discrimination ( n = 18). Finally, the logarithmic increase in entrainment to words was comparable in infants and adults, suggesting that infants and adults follow similar learning trajectories when tracking probability information among speech sounds. Statistical-learning effects in infants and adults may reflect overlapping neural mechanisms, which emerge early in life and are maintained throughout the life span.

Quantifying Sources of Variability in Infancy Research Using the Infant-Directed-Speech Preference

Psychological scientists have become increasingly concerned with issues related to methodology and replicability, and infancy researchers in particular face specific challenges related to replicability: For example, high-powered studies are difficult to conduct, testing conditions vary across labs, and different labs have access to different infant populations. Addressing these concerns, we report on a large-scale, multisite study aimed at (a) assessing the overall replicability of a single theoretically important phenomenon and (b) examining methodological, cultural, and developmental moderators. We focus on infants’ preference for infant-directed speech (IDS) over adult-directed speech (ADS). Stimuli of mothers speaking to their infants and to an adult in North American English were created using seminaturalistic laboratory-based audio recordings. Infants’ relative preference for IDS and ADS was assessed across 67 laboratories in North America, Europe, Australia, and Asia using the three common methods for measuring infants’ discrimination (head-turn preference, central fixation, and eye tracking). The overall meta-analytic effect size (Cohen’s d) was 0.35, 95% confidence interval = [0.29, 0.42], which was reliably above zero but smaller than the meta-analytic mean computed from previous literature (0.67). The IDS preference was significantly stronger in older children, in those children for whom the stimuli matched their native language and dialect, and in data from labs using the head-turn preference procedure. Together, these findings replicate the IDS preference but suggest that its magnitude is modulated by development, native-language experience, and testing procedure.

Learning speech-internal cues to pronoun interpretation from co-speech gesture: a training study

This study explores whether children can learn a structural processing bias relevant to pronoun interpretation from brief training. Over three days, 42 five-year-olds were exposed to narratives exhibiting a first-mentioned tendency. Two characters were introduced, and the first-mentioned was later described engaging in a solo activity. In our primary condition of interest, the Gesture Training condition, the solo-activity sentence contained an ambiguous pronoun, but co-speech gesture clarified the referent. There were two comparison conditions. In the Gender Training condition the characters were different genders, thereby avoiding ambiguity. In the Name Training condition, the first-mentioned name was simply repeated. Ambiguous pronoun interpretation was tested pre- and post-training. Children in the Gesture condition were significantly more likely to interpret ambiguous pronouns as the first-mentioned character after training. Results from the comparison conditions were ambiguous: there was a small but non-significant effect of training, but also no significant differences between conditions.

SOMENTHING WORHT-REMEMBERING

SOLUTIONS FOR INTRAVENOUS INFUSION

Unusual urticarias

Typical urticarial lesions are transient cutaneous swellings of sudden onset, often itchy, persisting for less than 24 hours and resolving to leave normal appearing skin. Angioedema lesions are similar subcutaneous lesions. Atypical urticarias persist for longer than 24 hours, may be painful and bruised in appearance and accompanied with severe systemic symptoms. Conditions where prolonged weals are present include delayed pressure urticaria and urticarial vasculitis. These conditions do not respond well to antihistamine therapy. In delayed pressure urticaria, weals appear after a delay of hours at sites of sustained pressure on the skin and occur in association with ordinary chronic 'idiopathic' urticaria. Weals of urticarial vasculitis show histological features of venulitis, and can be accompanied by arthralgia and abdominal pain. Rarely, the condition is due to infective or autoimmune disease. Urticarial diseases, sometimes with features of urticarial vasculitis, and with associated systemic features include Schnitzler's Syndrome, Still's disease and Muckle-Wells syndrome. The latter syndrome is linked with chromosome 1q44, as is autosomal dominant cold urticaria, an unusual physical urticaria. Persistent cholinergic erythema, a variant of cholinergic urticaria, has been mistaken for a drug eruption or cutaneous mastocytosis. Rarely, food and exercise induced urticaria and anaphylaxis occur when exercise follows a specific food or any meal within a few hours. The early stages of inflammatory disease may be mistaken for urticaria and angioedema, but lesions usually persist for longer than 48 hours and are accompanied by epidermal changes.

Methotrexate-responsive chronic idiopathic urticaria: a report of two cases

Chronic idiopathic urticaria (CIU) may be severe and refractory to standard therapies. We describe two patients with CIU, neither of whom had detectable autoantibodies, in whom control of the disease was achieved with methotrexate.

The clinical presentations of urticaria

Urticaria is a common skin condition. Although an episode may be mild and last only a few days, chronic urticaria can significantly affect the quality of life. The condition is frequently misunderstood by patients who believe the condition is always the result of an allergy and is dangerous.

Schnitzler's syndrome: no evidence for autoimmune basis in two patients

We report two cases of Schnitzler's syndrome in which anti-interleukin-1alpha autoantibodies and functional autoantibodies against the high affinity IgE receptor (FcepsilonRIalpha) or against IgE were absent. One patient responded well to TL-01 phototherapy, a treatment which may be considered in patients with Schnitzler's syndrome if, as is usually the case, they are unresponsive to antihistamine therapy.

Cutaneous inflammatory cell infiltrate in chronic idiopathic urticaria: comparison of patients with and without anti-FcepsilonRI or anti-IgE autoantibodies

BACKGROUND

Previous studies defining the histopathologic features of patients with chronic idiopathic urticaria (CIU) were performed on wheals of uncertain duration and before the identification of functional autoantibodies against FcepsilonRI and/or IgE, now known to be present in approximately 30% of patients with CIU.

OBJECTIVE

We sought to determine the timing of the inflammatory infiltrate in the wheals of patients with CIU and to detect differences between patients with and without autoantibodies.

METHODS

Immunohistochemistry was used to identify neutrophils (neutrophil elastase), T lymphocytes (CD3), and activated eosinophils (EG2) in biopsy specimens from uninvolved skin and wheals present for less than 4 hours and greater than 12 hours in 22 patients with CIU, as well as in biopsy specimens from the skin of 12 healthy control subjects. Patients were identified as having functional autoantibodies on the basis of their serum-evoked histamine release in vitro from the basophils of 2 healthy donors.

RESULTS

EG2(+), neutrophil elastase+, and, to a lesser extent, CD3(+) cells were found in greater numbers in wheals undergoing biopsy at less than 4 and greater than 12 hours than in uninvolved skin (P <.05). Patients without autoantibodies (n = 12) had significantly more EG2(+) cells in wheals of greater than 12 hours' duration than patients with autoantibodies (n = 10; P =.02). There was no other difference between patients with and without autoantibodies in the cutaneous cellular infiltrate.

CONCLUSION

Neutrophil and eosinophil accumulation occurs early in the evolution of a wheal in patients with CIU, but eosinophil activation may occur later or be more persistent in patients without autoantibodies.

Chronic idiopathic urticaria: comparison of the clinical features of patients with and without anti-FcepsilonRI or anti-IgE autoantibodies

BACKGROUND

Previous studies defining the clinical features of patients with chronic idiopathic urticaria (CIU) were performed before the identification of functional autoantibodies against FcepsilonRI and/or IgE, now known to be present in approximately 30% of patients with CIU.

OBJECTIVE

Our purpose was to determine whether there are differences between patients with and those without autoantibodies in the clinical features or severity of CIU.

METHODS

The clinical features of 107 patients with CIU were evaluated prospectively. Patients were identified as having functional autoantibodies on the basis of the serum-evoked histamine release in vitro from the basophils of 2 healthy donors.

RESULTS

Patients with autoantibodies (31%) had more wheals (P = .005), a wider distribution of wheals (P = .009), higher itch scores for the most severe episodes of itching (P = .002), more systemic symptoms (P = .03), and lower serum IgE levels (P < .0005) than patients without autoantibodies.

CONCLUSION

The presence of autoantibodies indicates a subset of patients with more severe CIU.

Anti-Fc(episilon)RI auto antibodies and basophil histamine releasability in chronic idiopathic urticaria

BACKGROUND

Circulating functional autoantibodies to the high-affinity IgE receptor (Fc(epsilon)RI) or to IgE have been found in approximately one third of patients with chronic idiopathic urticaria (CIU).

OBJECTIVE

We sought to compare basophil histamine release and basophil numbers in patients with CIU with and without autoantibodies.

METHODS

Basophil histamine release to the anti-Fc(epsilon)RI mAb 22E7, anti-IgE, and formyl-methionyl-leucyl-phenylalanine (fMLP); basophil numbers; and total cellular histamine were measured in 26 patients with CIU and 18 healthy control subjects. Twelve patients were classified as having functional anti-Fc(epsilon)RI and/or anti-IgE autoantibodies on the basis of their serum-evoked histamine release from the basophils of 2 healthy donors.

RESULTS

22E7 and anti-IgE, but not fMLP, released less histamine from basophils of patients with CIU than from those of control subjects. Mean+/-SEM maximum histamine release to 22E7 from basophils of control subjects and patients with CIU with and without autoantibodies was 38.5%+/-5.0%, 17.9%+/-6.0% (P =.01), and 1.0%+/-0.3% (P <.0001), respectively. Similar results were obtained with anti-IgE, which is dependent on and cross-links cell bound IgE, and 22E7, which directly cross-links the IgE receptor. The mean+/-SEM basophil counts for control subjects and patients with CIU without and with autoantibodies were 52+/-7, 34+/-9 (P =.04), and 5+/-1 (P <.0001) x 10(6) cells/L, respectively, and similar changes were found in measurements of total cellular histamine.

CONCLUSION

Patients with autoantibodies have both markedly reduced basophil numbers and basophil histamine release to factors acting through Fc(epsilon)RI, which indicates either a residual pool of functionally distinct basophils or may be a consequence of desensitization of the Fc(epsilon)RI pathway.

Intravenous immunoglobulin in autoimmune chronic urticaria

Histamine releasing autoantibodies play a central role in the pathogenesis of chronic urticaria (CU) in approximately 30% of affected patients. We investigated the therapeutic effect of high-dose intravenous immunoglobulin (IVIG) on disease activity in patients with severe CU of autoimmune aetiology. Autoimmune urticaria was diagnosed by the development of a weal-and-flare reaction to the intradermal injection of autologous serum and by serum-induced histamine release from the basophil leucocytes of healthy donors in vitro. Ten patients with severe, autoimmune CU, poorly responsive to conventional treatment, were treated with IVIG 0.4 g/kg per day for 5 days. The outcome on cutaneous wealing and itch was monitored using urticaria activity scores, visual analogue scales and autologous intradermal serum tests. Clinical benefit was noted in nine of 10 patients: three patients continue in prolonged complete remissions (3 years follow-up), two had temporary complete remissions, and symptoms in four patients improved subsequent to treatment. There was significant improvement in the urticaria activity scores and visual analogue scores at 2 (P < 0.01) and 6 weeks (P < 0.01) post-IVIG compared with the baseline values (Wilcoxon matched pairs). The diminution in urticarial activity in the majority of patients corresponded with a reduced weal-and-flare response to the intradermal injection of autologous post-treatment serum compared with the pretreatment serum. Minor side-effects were common, but there were no serious or long-term adverse effects. IVIG represents a novel therapeutic option in selected patients with recalcitrant CU associated with histamine releasing autoantibodies.

The pathogenesis of urticaria

The underlying pathophysiology of chronic urticaria is mast cell activation, with release of histamine and other mast cell mediators. A weal producing factor has been identified in the serum of 60% of patients with chronic idiopathic urticaria. In half of these patients there is evidence for functional autoantibodies against the high affinity IgE receptor or IgE, or both. These autoantibodies release histamine from basophils and mast cells. It is therefore likely that there is an autoimmune basis for up to 30% of patients with idiopathic urticaria. In the other half of patients whose serum causes weals, the factor releases histamine from mast cells only and is as yet unidentified. So far no clinical difference has been associated with presence/absence or type of weal producing factor. Exacerbating factors in chronic urticaria such as aspirin, food additives, febrile illness and psychological stress should be identified and avoided. Treatment is symptomatic with the low sedation antihistamines. In the most severe cases not responding to conventional therapy and which may have the weal producing factor, treatments with non specific immune therapy such as cyclosporin, and intravenous gammaglobulin and also plasmapheresis have been promising.

Angiotensin-converting enzyme (ACE) inhibitors and angio-oedema

Angiotensin-converting enzyme inhibitors (ACEIs) are used increasingly for the treatment of hypertension and chronic heart failure, and they reduce mortality when given after myocardial infarction. Of the patients prescribed these drugs 0.1-0.7% develop angio-oedema, but the association is not widely recognized. In 60% of cases the onset occurs during the first week of treatment; however, it may be considerably delayed. Angio-oedema nearly always occurs on the head and neck, frequently involving the mouth, tongue, pharynx and larynx. The course is unpredictable, and attacks vary in severity from mild to fatal from laryngeal obstruction. Severe ACEI-induced angio-oedema may require emergency treatment with adrenalin and early intubation. The drug should be withdrawn in any patient who presents with ACEI-induced angio-oedema, and treatment continued with an appropriate drug of a different class. Therapy with ACEIs is contraindicated in patients with a prior history of idiopathic angio-oedema, or in patients with hereditary or acquired C1 esterase inhibitor deficiency.

Vitamin B-12 deficiency and malabsorption are highly prevalent in rural Mexican communities

Vitamin B-12 status of rural Mexicans was evaluated in two studies, 6 y apart. In the first, a single blood sample was collected from children and adults, including pregnant and lactating women. Prevalence of deficient plasma vitamin B-12 values ranged from 19% to 41% among groups, but plasma folate status was normal in all individuals. Breast milk vitamin B-12 concentration was low in 62% of samples. The second study was conducted in 219 children aged 18-36 mo in five communities, whose prevalence of deficient and low plasma vitamin B-12 concentrations, respectively, was 8% and 33% on entry, 3% and 22% 6 mo later, and 7% and 29% 12 mo later. Prevalence of low holotranscobalamin II concentrations, indicating malabsorption of the vitamin, averaged 18-40% across the three same periods. Both vitamin B-12 status indicators differed significantly between communities. The widespread vitamin B-12 deficiency was probably caused by malabsorption, perhaps exacerbated by low dietary intake and, for young children, maternal depletion of the vitamin.

Urticarial vasculitis

Urticarial vasculitis describes a distinct entity in which the gross cutaneous lesions resemble urticaria and histologically show features of a vasculitis. The incidence of vasculitis in patients with apparent urticaria is between 2% and 20%. The diagnosis is suggested clinically by more persistent (lasting > 24 hours) and more symptomatic weals than in ordinary urticaria and by the presence of residual bruising. In addition to the skin the musculoskeletal, respiratory, renal and gastrointestinal systems may be involved in the disease, which is probably an immune complex mediated process. Urticarial vasculitis is most commonly an acquired idiopathic phenomenon but may occur in association with other disorders most often systemic lupus erythematosus, Sjögren's syndrome and serum sickness. In this article we review the background, histopathology, clinical features, extracutaneous manifestations, pathogenesis, aetiology, associated diseases, investigation, treatment, course and prognosis of urticarial vasculitis.

The effects of topical corticosteroids on delayed pressure urticaria

Six patients with delayed pressure urticaria (DPU) applied clobetasol propionate (0.05%) ointment or its base to predetermined test sites on the right and left thigh as part of a randomized, double-blind study. A pressure challenge was administered to each test site at the initial visit and repeated after 3 days and 6 weeks of treatment and at between 4 and 8 weeks after treatment. The areas of pressure-induced weals were measured 6 h after each challenge. At the 6-week visit, a 4-mm punch biopsy was taken from pressure-challenged skin on each test site. Sections were stained for mast cells and immunohistochemical labelling was used to demonstrate neutrophils (neutrophil elastase), eosinophils (eosinophil cationic protein), monocytes/macrophages (EBM 11), cells expressing the beta-2 integrins (CD11/18) and the vascular adhesion molecules, E selectin and intercellular adhesion molecule-1 (ICAM-1). In the steroid-treated sites, there was a significant decrease (P < 0.05, Wilcoxon's matched-pairs test) in the size of the pressure weals compared with baseline at 3 days, 6 weeks and at follow-up. Demonstrable mast cells were significantly decreased (P = 0.059) in the pressure-challenged areas in the steroid-treated sites compared with the base-treated sites. The histological response to pressure was minimal in both sites perhaps demonstrating an active pharmacological effect of the ointment base. In conclusion, the application of potent topical steroids significantly reduced the clinical response to pressure in patients with DPU, possibly through a reduction in mast cells.

Adhesion molecule expression and the inflammatory cell infiltrate in delayed pressure urticaria

We have investigated the kinetics of the leucocyte infiltrate in delayed pressure urticaria (DPU) in relation to the in vivo expression of the cytokine-regulated cell surface adhesion molecules, E-selectin (endothelial adhesion molecule-1, ELAM-1), intercellular adhesion molecule-1 (ICAM-1), and vascular adhesion molecule-1 (VCAM-1). Immunohistochemical analysis was performed on biopsies taken from unchallenged skin, and at 0, 2, 6, 24, 48 and 120 h after weighted rods had been applied to 13 patients with DPU. There was moderate to marked upregulation of E-selectin at 6 and 24 h after application of pressure. At 24 h, more patients showed expression of VCAM-1 on perivascular cells than before pressure. Moderate expression of ICAM-1 was present in some biopsies from both unchallenged and pressure-challenged skin, but there was no clear trend. In DPU, there was a significant increase in the neutrophil count at 2 h after a pressure challenge, with further increases at 6 and 24 h. The median cell counts per high-power field of eosinophils and monocyte/macrophages increased significantly at 24 h after pressure. Biopsies from four normal controls subjected to an identical pressure challenge showed no detectable changes in adhesion molecule expression or in the cell infiltrate. The findings in four patients with chronic idiopathic urticaria not associated with DPU were qualitatively similar to (but intermediate in severity between) the findings in DPU weals at 6 and 24 h. These results suggest that vascular endothelial activation is an early response to pressure challenge in DPU, and is also present in chronic idiopathic urticaria.(ABSTRACT TRUNCATED AT 250 WORDS)

Iron, vitamin B-12 and folate status in Mexico: associated factors in men and women and during pregnancy and lactation

To determine the prevalence and causes of anemia in rural Mexico, blood samples and longitudinal dietary data were collected from 187 women, some pregnant and then lactating, and from 72 men. Blood was used to measure anemia, mean cell volume, and plasma ferritin, folate and vitamin B-12. Anemia was found in 33% of the men, 54% of nonpregnant, nonlactating women, 35% of pregnant women and 41% of lactating women, and varied by season. Low iron stores (ferritin) accompanied anemia in only 8% of men compared with 38-67% of women. Low meat intake and poor dietary iron bioavailability were associated with anemia in women. There were no cases of low plasma folate. Low plasma vitamin B-12 was common in all groups, and the incidence increased from 15% at 7 mo of pregnancy to 30% at 7 mo of lactation. Vitamin B-12 was lower in the plasma and milk of anemic lactating women than in plasma and milk of non-anemic lactating women and was classified as deficient in 62% of breast milk samples.

Diagnosis and incidence of delayed pressure urticaria in patients with chronic urticaria

BACKGROUND

The incidence of delayed pressure urticaria (DPU) may have been underestimated, particularly in patients with widespread wheals of concurrent idiopathic urticaria, because of difficulty in recognizing the association between pressure-related swellings and the preceding physical stimulus. Diagnostic tests for DPU have not been done routinely in studies of urticaria and have not been compared.

OBJECTIVE

Our purpose was to establish the incidence of DPU and other physical urticarias in patients with chronic urticaria and to compare two reproducible pressure challenge tests.

METHODS

One hundred thirty-five patients were tested for immediate dermographism, for DPU and, when indicated by the history, for cholinergic and/or cold urticaria. In patients with pressure-related symptoms, pressure challenge testing with a dermographometer (100 gm/mm2) was compared with a test that involves the application of 1.5 cm diameter weighted rods and more closely resembles a naturally occurring pressure stimulus.

RESULTS

Physical urticarias were present in 96 patients (71%). Thirty patients (22%) had immediate dermographism, 50 (37%) had DPU, 15 (11%) had cholinergic urticaria, and 3 (2%) had cold urticaria. A 70-second pressure challenge with the dermographometer gave results comparable to the use of the weighted rods.

CONCLUSION

DPU appears to be more common in chronic urticaria than previously reported and is present in some patients who do not report pressure-related wheals.

Cloning and characterization of a lignin peroxidase gene from the white-rot fungus Trametes versicolor

Six putative lignin peroxidase (LIP) genes were isolated from a lambda EMBL3 phage library of the white-rot fungus, Trametes versicolor, using the Phanerochaete chrysosporium LIP cDNA CLG5 as the probe. Sequence analysis of one of the genes, VLG1, showed that its coding region is interrupted by six small introns (49-64 bp) and that it encodes a mature LIP protein (341 aa; Mr: 36,714) that is preceded by a 25 aa signal sequence. This protein has a relatively high degree of aa homology to the N-termini of the LIP proteins purified from T. versicolor and has an aa homology of 55-60% to the LIP proteins of P. chrysosporium, which is comparable to that found between P. chrysosporium and Phlebia radiata LIP proteins.

Contact urticaria due to the common stinging nettle (Urtica dioica)--histological, ultrastructural and pharmacological studies

A frequent cause of contact urticaria is skin exposure to the common stinging nettle (Urtica dioica). The urticaria is accompanied by a stinging sensation lasting longer than 12 h. Little is known of the cellular and molecular mechanism of stinging-nettle urticaria. After preliminary pharmacological analysis of pro-inflammatory activity in nettle stings, the cellular response of mononuclear cells, polymorphonuclear cells and mast cells was examined in six people 5 min and 12 h after nettle contact. Only mast cell numbers were significantly increased at 12 h. Ultrastructurally, some mast cells showed evidence of degranulation at 5 min and 12 h. At 12 h mast cells were closely associated with dermal dendritic cells and lymphocytes suggesting a functional unit. The mean histamine and serotonin contents of a nettle hair were found to be 6.1 ng and 33.25 pg, respectively. Nettle-sting extracts did not demonstrate histamine release from dispersed rat mast cells in vitro. These results suggest that part of the immediate reaction to nettle stings is due to histamine introduced by the nettle. However, the persistence of the stinging sensation might suggest the presence of substances in nettle fluid directly toxic to nerves or capable of secondary release of other mediators.

Radiobiological studies in the naevoid basal cell carcinoma syndrome

The naevoid basal cell carcinoma syndrome is described in a 43-year-old male. The response of dividing fibroblasts from this patient to the lethal effects of ionizing radiation was indistinguishable from that of a normal control: mean inactivation dose (D) = 1.74 Gy and 1.68 Gy, respectively. However, these cells were defective in the repair of potentially lethal damage (D = 2.36 Gy and 3.26 Gy, respectively). The response to radiation of Go T lymphocytes derived from the patient was similar to that of the control. The frequency of mutant circulating T lymphocytes resistant to 6-thioguanine was 17 x 10(-6) which was elevated when compared with age-matched controls. These results suggest an abnormality in the response of the fibroblasts to ionizing radiation damage.

Skin exudate levels of interleukin 6, interleukin 1 and other cytokines in mycosis fungoides

The role of locally released cytokines in inducing lymphocyte activation and infiltration in the skin lesions of mycosis fungoides has been investigated. The levels of selected cytokines were measured in chamber fluid samples from lesional and control skin. Biologically active interleukin 6 was significantly elevated in lesional samples and a recombinant form of this cytokine was shown to induce lymphocyte migration in an in vitro assay. Biologically active interleukin 1 was detected in all control chamber fluid samples. Significantly reduced levels of this cytokine were present in lesional samples, which may be the result of the release of preformed material. Interleukin 2 and tumour necrosis factor activity, and gamma interferon and granulocyte macrophage colony-stimulating factor immunoreactivity, were not detectable in any of the samples. Interleukins 1 and 6 may play a role in the pathogenesis of the lesional lymphocyte infiltrates in mycosis fungoides.

Pharmacologic and clinical effects of lonapalene (RS 43179), a 5-lipoxygenase inhibitor, in psoriasis

The pharmacologic and clinical effects of the 5-lipoxygenase inhibitor, lonapalene, have been determined in a double-blind, placebo-controlled, topical study in ten volunteers with psoriasis. A statistically significant clinical improvement was seen in lesions treated with 2% lonapalene ointment as compared with vehicle-treated sites. Although there was a statistically significant reduction in the levels of material similar or identical to the chemoattractant arachidonate 5-lipoxygenase product, leukotriene B4, in skin chamber fluid samples from lonapalene versus vehicle treated lesions, no significant reduction in arachidonic acid or 12-hydroxy-5,8,10,14-eicosatetraenoic acid was seen. The reduction in leukotriene B4 equivalents occurred before significant clinical improvement in lesions was seen. This and the selectivity of the pharmacologic response suggest that the therapeutic effect of topical lonapalene in psoriasis might be related to inhibition of leukotriene B4 synthesis. These results support the view that 5-lipoxygenase inhibitors may be useful in the treatment of psoriasis, and that leukotriene B4 is a relevant mediator of the pathology of this disease.

Symptomatic dermographism: wealing, mast cells and histamine are decreased in the skin following long-term application of a potent topical corticosteroid

Clobetasol propionate 0.05% ointment and an otherwise identical steroid-free base were applied topically to a 10 cm2 area on the anterior thighs of six patients with symptomatic dermographism for 6 weeks. Four patients showed a significantly decreased wealing response to stroking of steroid pretreated skin compared to that of control sites. There was a parallel decrease in mast cell numbers and histamine levels in skin biopsies taken from the steroid treated areas. At 6 weeks two patients demonstrated a decrease in flare areas following the intradermal injection of compound 48/80 in steroid pretreated skin compared to base treated sites. Flare areas following intradermal injection of histamine in these two patients were equivalent in base and steroid treated skin.

Delayed pressure urticaria, objective evaluation of a variable disease using a dermographometer and assessment of treatment using colchicine

A randomized double-blind placebo controlled trial of colchicine in the treatment of 13 patients with delayed pressure urticaria enabled us to assess some of the variables in this disorder. We have modified a previously described method of pressure testing using a calibrated dermographometer and shown a pressure induced papular dose response curve. Assessment of disease activity was based on the number of pressure weals which occurred, the size of delayed pressure induced papules using a dermographometer calibrated at 9.75 x 10(5) pascals for five separate time periods on the back and estimations of erythrocyte sedimentation rate and the acute phase protein levels. We have been unable to show a therapeutic effect using colchicine 0.5 mg bd for I week.

Vibratory angioedema: lesion induction, clinical features, laboratory and ultrastructural findings and response to therapy

We report the investigation and treatment of a 28-year-old woman with the rare condition of non-familial vibratory angiodema. Lesions were reproduced using a vibrator set at pre-determined frequencies and amplitudes, applied for a fixed time period. There was no indication of the production of tolerance in the patient with repeated vibration, but terfenadine produced a good therapeutic response. There was no evidence of mast cell degranulation at the ultrastructural level. The patient also had mild delayed pressure urticaria and dermographism, thus demonstrating the clustering frequently found in the physical urticarias.

The release of prostaglandin D2 from human skin in vivo and in vitro during immediate allergic reactions

1. The release of prostaglandin D2 (PGD2) during immediate allergic reactions in human skin was investigated in vivo and in vitro. 2. Skin exudates were collected from abraded sites on the thigh of atopic subjects sensitive to D. pteronyssinus antigen and from non-atopic control subjects. Challenge with antigen caused the release of PGD2 and histamine, but not PGE2, from the skin of the atopic subjects. The molar ratio of histamine to PGD2 was about 140:1. Control subjects were unresponsive. 3. PGD2 was released from passively sensitized human skin challenged with antigen in vitro. The time course was similar in vitro and in vivo. The ratio of histamine to PGD2 in vitro was 78:1. 4. The identities of the prostaglandins were confirmed by high performance liquid chromatography and radioimmunoassay to PGD2 and PGE2. 5. PGD2 is the major arachidonic acid cyclo-oxygenase product synthesized by human mast cells. It is pro-inflammatory in human skin but its functions as a mediator in immediate hypersensitivity reactions in human skin are not clear. The results of this study suggest that, relative to histamine, PGD2 contributes little to the oedema and erythema of immediate reactions in human skin.

Delayed pressure urticaria. Clinical features, laboratory investigations, and response to therapy of 44 patients

We studied 44 patients with delayed pressure urticaria. The mean age at onset of the disease was 33 years (range, 5 to 63 years) and the mean duration of disease was 9 years (range, 1 to 40 years). After pressure stimulus, the mean onset of whealing occurred in 3 1/2 hours, the mean peak swelling occurred after 10 hours, and the mean lesion duration was 36 hours. Two thirds of patients had generalized flulike symptoms. Sixty percent had disabling nonremitting delayed pressure urticaria. Sixty-two percent had coexistent chronic idiopathic urticaria, and 27% had angioedema. Delayed pressure urticaria was confirmed by pressure tests with either a calibrated dermographometer or suspended weights. More than 50% of patients tested also had delayed dermographism. A double-blind, controlled, crossover trial of indomethacin therapy in 14 patients revealed no significant subjective improvement or reduction in area of induced wheals. We conclude: (1) The diagnosis of delayed pressure urticaria can be easily made by dermographometer testing. (2) Delayed dermographism may be the same entity as delayed pressure urticaria induced by a different method of pressure application. (3) Systemic corticosteroids remain the only known effective treatment for disabling delayed pressure urticaria.

The in vitro 5-lipoxygenase and cyclo-oxygenase inhibitor L-652,343 does not inhibit 5-lipoxygenase in vivo in human skin

1 3-hydroxy-5-trifluoromethyl-N-[2-(2-thienyl)-2-phenyl-ethenyl]-benzo(B) thiophene-2-carboxamide (L-652,343) is a 5-lipoxygenase and cyclo-oxygenase inhibitor in vitro. 2 In psoriasis increased concentrations of arachidonic acid transformation products are found in the lesional skin which may be important in the pathogenesis of the disease. We have measured the effect of orally administered L-652,343 on the concentration of LTB4 and prostaglandins in the lesional skin. 3 Eight patients with stable chronic plaque psoriasis received 500 and 250 mg of L-652,343, 12 h apart. A chamber technique was used to collect skin exudate samples from abraded plaques before and at 4, 24 and 48 h after the first dose. Exudates were analysed for LTB4 by a neutrophil chemokinesis assay and for PGE2 and PGD2 by RIA. 4 PGE2 and PGD2 levels were significantly reduced at 4 and 24 h after the first dose of L-652,343 but LTB4 levels were not affected indicating inhibition of the cyclo-oxygenase pathway but not of the 5-lipoxygenase pathway. This shows the importance of confirming that the action of 5-lipoxygenase inhibiting drugs in vitro occurs in vivo.

Cutaneous responses to 12-hydroxy-5,8,10,14-eicosatetraenoic acid (12-HETE) and 5,12-dihydroxyeicosatetraenoic acid (leukotriene B4) in psoriasis and normal human skin

The arachidonate lipoxygenase products 12-hydroxy-5,8,10,14-eicosatetraenoic acid (12-HETE) and 5(S),12(R)-dihydroxy-6,8,10,14-eicosatetraenoic acid (leukotriene B4, LTB4) are potent leucocyte chemoattractants in vitro and in vivo. Both 12-HETE and LTB4-like material are found in increased amounts in lesional skin in psoriasis. Epicutaneous administration of 12(R,S)-HETE and LTB4 in normal skin evokes neutrophil and mononuclear dermal infiltrates accompanied by collections of neutrophils in the epidermis. Similar appearances result from the application of LTB4 to uninvolved skin in psoriasis. We have now investigated the effects of single and multiple epicutaneous applications of 12(R,S)-HETE and LTB4, both alone and in combination, in normal human skin and in clinically uninvolved skin of patients with psoriasis. As in the case of LTB4, erythematous responses to 12(R,S)-HETE were similar in normal skin and in psoriasis. Similar neutrophil polymorphonuclear responses were evoked by topical application of 50 ng LTB4 and 20 micrograms 12(R,S)-HETE. Application of the combination of 12(R,S)-HETE and LTB4 evoked only a partially additive erythematous response, and no evidence of an additive neutrophilotactic response was detected histologically. Multiple applications resulted in tolerance both clinically and histologically. Cross tolerance to 12(R,S)-HETE and LTB4 occurred in the majority of subjects. These results suggest that both 12(R,S)-HETE and LTB4 may be important in the production and control of the magnitude of the inflammatory events in psoriasis.

Lipoxygenase products of arachidonic acid in human inflamed skin

Monohydroxy acids (HETEs) and leukotriene B4 (LTB4) metabolites of arachidonic acid were measured in skin of healthy volunteers after ultraviolet B irradiation, and in the uninvolved skin of psoriatics after topical dithranol application. Exudate was collected from suction bullae on control and inflamed abdominal skin, and analysed for 12-HETE and PGE2 by GC-MS and LTB4 by bioassay. 12-HETE and PGE2 were raised at 24 h but not at 72 h after u.v.B irradiation: control and 24 h values were 13.7 and 41.5 ng ml-1 (P less than 0.05, n = 6) for 12-HETE respectively, and 4.5 and 30.2 ng ml-1 (P less than 0.01, n = 6) for PGE2. Dithranol application raised PGE2 levels from 23.1 ng ml-1 in control exudate to 62 ng ml-1 (P less than 0.01, n = 6) at 24 h before declining to base levels at 72 h. However, 12-HETE was raised at 72 h (200 ng ml-1, P less than 0.01, n = 5) but not at 24 h (104 ng ml-1) compared to control levels (50 ng ml-1, n = 5). The levels of the LTB4 were low (less than 100 pg ml-1), and no significant increases were observed. Arachidonic acid in inflamed skin can be metabolised by the cyclo-oxygenase and lipoxygenase pathway. It is probable that the lipoxygenase product 12-HETE is involved in these inflammatory reactions.

Leukotrienes C4 and D4 in psoriatic skin lesions

Chemoattractant arachidonate lipoxygenase products have been recovered from the skin lesions of psoriasis, and may play a role in eliciting the intra-epidermal neutrophil infiltrate that characterises this disease. In view of evidence for lipoxygenase activity in psoriasis, the characteristic vasodilation in psoriatic lesions, and the vasodilator properties of leukotriene (LT) C4 and D4 in human skin, the presence of these LTs in psoriatic lesions has been investigated. Skin chamber fluid from abraded psoriatic lesions contained significantly greater amounts of immunoreactive material than that from clinically normal skin, as determined by a double antibody radioimmunoassay (RIA) that uses antiserum cross-reacting with both LTC4 and LTD4. Purification of lesional chamber fluid and scale extracts by high performance liquid chromatography (HPLC) and RIA of fractions showed immunoreactivity which co-eluted with standard LTC4 and LTD4. These findings suggest that LTC4 and LTD4 may play a role in mediating the vasodilation and increased blood flow that characterise psoriatic skin lesions.

Mechanical trauma and urticaria

Urticarial responses in skin may be elicited in different ways, viz, stroking (dermographism), after sustained pressure (delayed pressure urticaria), and after vibration (vibratory angio-oedema). Pressure may localise lesions of chronic idiopathic urticaria. Trauma may exacerbate hereditary angio-oedema. The extent of the morbidity caused by trauma-induced urticaria among workers is unknown.

Leukotriene B4-like material in scale of psoriatic skin lesions

Acidic lipid extracts of scale from the lesions of the skin disease, psoriasis, were purified by straight phase high performance liquid chromatography (h.p.l.c.). Assay of fractions by an agarose microdroplet chemokinesis method showed the presence of biologically active material that coeluted with standard leukotriene B4 (LTB4). LTB4-like chemokinetic activity was also detected in fractions collected on reversed phase h.p.l.c. of psoriatic scale extracts that were initially purified by straight phase h.p.l.c. No LTB4-like activity was detected after similar purification of scale obtained by abrasion of large areas of normal skin. The LTB4-like material found in extracts of psoriatic scale may play a role in the pathogenesis of the neutrophil infiltrate which characterizes psoriasis.

The release of leukotriene B4-like material in biologically active amounts from the lesional skin of patients with psoriasis

The 5,12-dihydroxy metabolite of arachidonic acid, leukotriene B4, is a highly potent neutrophil chemoattractant. In view of the characteristic epidermal neutrophil infiltrate in psoriasis, the presence of leukotriene B4 in samples from untreated lesional and uninvolved skin has been sought. Chambers were fixed to abraded skin and filled with phosphate-buffered saline (PBS). After 35 min, the fluid was removed, and acidic lipids were extracted and subjected to high-performance liquid chromatography (HPLC). Extracts were purified by both straight- and reversed-phase HPLC, and assay of evaporated fractions by an agarose microdroplet chemokinesis technique indicated the presence of leukotriene B4-like material. No significant leukotriene B4-like activity was found in samples from uninvolved skin. Subsequent experiments using a modification of the initial skin chamber method indicated that leukotriene B4 was being released from deeper layers of lesional skin and not only from superficial scale. Monohydroxy-eicosatetraenoic acid-like activity was also seen in lesional samples as determined by straight-phase HPLC and chemokinesis assay. These findings and the proinflammatory properties of these compounds in human skin suggest that they may play a role in the pathogenesis of the psoriatic neutrophil infiltrate.

The identification of hydroxy fatty acids in psoriatic skin

Psoriasis is a common chronic inflammatory and proliferative skin disease characterised by epidermal neutrophil infiltration which may be induced by chemotactic substances in the involved epidermis. Superficial psoriatic scale was shown to contain biologically active amounts of leukotriene B4 and monohydroxy-eicosatetraenoic acid (HETE)-like material as determined by assay for chemokinetic activity in high performance liquid chromatography (HPLC) fractions of scale extracts. Extracts of scale and chamber fluid from abraded lesional and uninvolved psoriatic skin were purified by HPLC and appropriate fractions were analysed by gas chromatography - mass spectrometry (GC-MS). The following monohydroxy metabolites of arachidonic, linoleic and 11,14-eicosadienoic acids were identified: 15-HETE, 12-HETE, 11-HETE, 9-HETE, 8-HETE, 5-HETE, 13-hydroxy-octadecadienoic acid (13-HODD), 9-HODD and 15-hydroxy-eicosadienoic acid (15-HEDE). The results suggested that 12-HETE, 13-HODD and 9-HODD are the most abundant monohydroxy fatty acids in the psoriatic skin extracts described above. Assays of 13-HODD, 9-HODD and 15-HEDE for chemokinetic activity were negative with concentrations up to 10(-4)M. The biological significance of these three compounds in not known, but some of the hydroxylated metabolites of arachidonic acid may, by virtue of their chemotactic properties, be relevant to the pathogenesis of the psoriatic neutrophil infiltrate.

Persisting cholinergic erythema: a variant of cholinergic urticaria

A new variant of cholinergic urticaria is described. Four patients each had a similar persistent macular skin rash distributed maximally over the upper limbs and upper trunk. Though the rash was persistent, individual macules were of short duration but new macules continually appeared at adjacent sites. Exercise and hot baths exacerbated pruritus and provoked lesions in previously unaffected areas. Topically applied benzoyl scopolamine blocked the appearance of the lesions after challenge. Tests of cholinergic function were normal, apart from an exaggerated pupillary response to arecoline in one patient.

Histologic changes associated with ultraviolet A--induced erythema in normal human skin

We have examined the effects of a standardized, moderately erythemogenic dose of long-wave ultraviolet (UVA) radiation on normal human skin, with the use of an appropriately filtered solar simulator and sequential biopsy specimens processed as 1-micron Epon-embedded sections. Histologic changes were present immediately after irradiation and evolved slowly during the 48-hour study. The epidermis manifested slight intracellular and intercellular edema and progressive loss of Langerhans cells to approximately one-fifth control values. A dermal infiltrate of neutrophilic polymorphonuclear leukocytes was present in all postirradiation specimens and peaked at 3 hours. A perivascular lymphocytic infiltrate, moderate endothelial cell enlargement, mast cell hypogranulation, occasional massive venular dilation, and sparse red blood cell extravasation were also noted. Overall, our findings expand and quantify earlier impressions that, compared to UVB, UVA has a relatively greater histologic effect on the dermis than on the epidermis, depletes epidermal Langerhans cells, and recruits neutrophils into irradiated human skin.