Spatiotemporal Dynamics of Attention Networks Revealed by Representational Similarity Analysis of EEG and fMRI

The fronto-parietal attention networks have been extensively studied with functional magnetic resonance imaging (fMRI), but spatiotemporal dynamics of these networks are not well understood. We measured event-related potentials (ERPs) with electroencephalography (EEG) and collected fMRI data from identical experiments where participants performed visual and auditory discrimination tasks separately or simultaneously and with or without distractors. To overcome the low temporal resolution of fMRI, we used a novel ERP-based application of multivariate representational similarity analysis (RSA) to parse time-averaged fMRI pattern activity into distinct spatial maps that each corresponded, in representational structure, to a short temporal ERP segment. Discriminant analysis of ERP-fMRI correlations revealed 8 cortical networks-2 sensory, 3 attention, and 3 other-segregated by 4 orthogonal, temporally multifaceted and spatially distributed functions. We interpret these functions as 4 spatiotemporal components of attention: modality-dependent and stimulus-driven orienting, top-down control, mode transition, and response preparation, selection and execution.

Functional Imaging of Audio-Visual Selective Attention in Monkeys and Humans: How do Lapses in Monkey Performance Affect Cross-Species Correspondences?

The cross-species correspondences and differences in how attention modulates brain responses in humans and animal models are poorly understood. We trained 2 monkeys to perform an audio–visual selective attention task during functional magnetic resonance imaging (fMRI), rewarding them to attend to stimuli in one modality while ignoring those in the other. Monkey fMRI identified regions strongly modulated by auditory or visual attention. Surprisingly, auditory attention-related modulations were much more restricted in monkeys than humans performing the same tasks during fMRI. Further analyses ruled out trivial explanations, suggesting that labile selective-attention performance was associated with inhomogeneous modulations in wide cortical regions in the monkeys. The findings provide initial insights into how audio–visual selective attention modulates the primate brain, identify sources for “lost” attention effects in monkeys, and carry implications for modeling the neurobiology of human cognition with nonhuman animals.

Brain activity associated with selective attention, divided attention and distraction

Top-down controlled selective or divided attention to sounds and visual objects, as well as bottom-up triggered attention to auditory and visual distractors, has been widely investigated. However, no study has systematically compared brain activations related to all these types of attention. To this end, we used functional magnetic resonance imaging (fMRI) to measure brain activity in participants performing a tone pitch or a foveal grating orientation discrimination task, or both, distracted by novel sounds not sharing frequencies with the tones or by extrafoveal visual textures. To force focusing of attention to tones or gratings, or both, task difficulty was kept constantly high with an adaptive staircase method. A whole brain analysis of variance (ANOVA) revealed fronto-parietal attention networks for both selective auditory and visual attention. A subsequent conjunction analysis indicated partial overlaps of these networks. However, like some previous studies, the present results also suggest segregation of prefrontal areas involved in the control of auditory and visual attention. The ANOVA also suggested, and another conjunction analysis confirmed, an additional activity enhancement in the left middle frontal gyrus related to divided attention supporting the role of this area in top-down integration of dual task performance. Distractors expectedly disrupted task performance. However, contrary to our expectations, activations specifically related to the distractors were found only in the auditory and visual cortices. This suggests gating of the distractors from further processing perhaps due to strictly focused attention in the current demanding discrimination tasks.

Media multitasking is associated with distractibility and increased prefrontal activity in adolescents and young adults

The current generation of young people indulges in more media multitasking behavior (e.g., instant messaging while watching videos) in their everyday lives than older generations. Concerns have been raised about how this might affect their attentional functioning, as previous studies have indicated that extensive media multitasking in everyday life may be associated with decreased attentional control. In the current study, 149 adolescents and young adults (aged 13-24years) performed speech-listening and reading tasks that required maintaining attention in the presence of distractor stimuli in the other modality or dividing attention between two concurrent tasks. Brain activity during task performance was measured using functional magnetic resonance imaging (fMRI). We studied the relationship between self-reported daily media multitasking (MMT), task performance and brain activity during task performance. The results showed that in the presence of distractor stimuli, a higher MMT score was associated with worse performance and increased brain activity in right prefrontal regions. The level of performance during divided attention did not depend on MMT. This suggests that daily media multitasking is associated with behavioral distractibility and increased recruitment of brain areas involved in attentional and inhibitory control, and that media multitasking in everyday life does not translate to performance benefits in multitasking in laboratory settings.

Brain activations during bimodal dual tasks depend on the nature and combination of component tasks

We used functional magnetic resonance imaging to investigate brain activations during nine different dual tasks in which the participants were required to simultaneously attend to concurrent streams of spoken syllables and written letters. They performed a phonological, spatial or “simple” (speaker-gender or font-shade) discrimination task within each modality. We expected to find activations associated specifically with dual tasking especially in the frontal and parietal cortices. However, no brain areas showed systematic dual task enhancements common for all dual tasks. Further analysis revealed that dual tasks including component tasks that were according to Baddeley's model “modality atypical,” that is, the auditory spatial task or the visual phonological task, were not associated with enhanced frontal activity. In contrast, for other dual tasks, activity specifically associated with dual tasking was found in the left or bilateral frontal cortices. Enhanced activation in parietal areas, however, appeared not to be specifically associated with dual tasking per se, but rather with intermodal attention switching. We also expected effects of dual tasking in left frontal supramodal phonological processing areas when both component tasks required phonological processing and in right parietal supramodal spatial processing areas when both tasks required spatial processing. However, no such effects were found during these dual tasks compared with their component tasks performed separately. Taken together, the current results indicate that activations during dual tasks depend in a complex manner on specific demands of component tasks.

Brain activity during divided and selective attention to auditory and visual sentence comprehension tasks

Using functional magnetic resonance imaging (fMRI), we measured brain activity of human participants while they performed a sentence congruence judgment task in either the visual or auditory modality separately, or in both modalities simultaneously. Significant performance decrements were observed when attention was divided between the two modalities compared with when one modality was selectively attended. Compared with selective attention (i.e., single tasking), divided attention (i.e., dual-tasking) did not recruit additional cortical regions, but resulted in increased activity in medial and lateral frontal regions which were also activated by the component tasks when performed separately. Areas involved in semantic language processing were revealed predominantly in the left lateral prefrontal cortex by contrasting incongruent with congruent sentences. These areas also showed significant activity increases during divided attention in relation to selective attention. In the sensory cortices, no crossmodal inhibition was observed during divided attention when compared with selective attention to one modality. Our results suggest that the observed performance decrements during dual-tasking are due to interference of the two tasks because they utilize the same part of the cortex. Moreover, semantic dual-tasking did not appear to recruit additional brain areas in comparison with single tasking, and no crossmodal inhibition was observed during intermodal divided attention.

Attention effects on the processing of task-relevant and task-irrelevant speech sounds and letters

We used event-related brain potentials (ERPs) to study effects of selective attention on the processing of attended and unattended spoken syllables and letters. Participants were presented with syllables randomly occurring in the left or right ear and spoken by different voices and with a concurrent foveal stream of consonant letters written in darker or lighter fonts. During auditory phonological (A_P) and non-phonological tasks, they responded to syllables in a designated ear starting with a vowel and spoken by female voices, respectively. These syllables occurred infrequently among standard syllables starting with a consonant and spoken by male voices. During visual phonological and non-phonological tasks, they responded to consonant letters with names starting with a vowel and to letters written in dark fonts, respectively. These letters occurred infrequently among standard letters with names starting with a consonant and written in light fonts. To examine genuine effects of attention and task on ERPs not overlapped by ERPs associated with target processing or deviance detection, these effects were studied only in ERPs to auditory and visual standards. During selective listening to syllables in a designated ear, ERPs to the attended syllables were negatively displaced during both phonological and non-phonological auditory tasks. Selective attention to letters elicited an early negative displacement and a subsequent positive displacement (Pd) of ERPs to attended letters being larger during the visual phonological than non-phonological task suggesting a higher demand for attention during the visual phonological task. Active suppression of unattended speech during the A_P and non-phonological tasks and during the visual phonological tasks was suggested by a rejection positivity (RP) to unattended syllables. We also found evidence for suppression of the processing of task-irrelevant visual stimuli in visual ERPs during auditory tasks involving left-ear syllables.

Task-dependent activations of human auditory cortex to prototypical and nonprototypical vowels

Research in auditory neuroscience has largely neglected the possible effects of different listening tasks on activations of auditory cortex (AC). In the present study, we used high-resolution fMRI to compare human AC activations with sounds presented during three auditory and one visual task. In all tasks, subjects were presented with pairs of Finnish vowels, noise bursts with pitch and Gabor patches. In the vowel pairs, one vowel was always either a prototypical /i/ or /ae/ (separately defined for each subject) or a nonprototype. In different task blocks, subjects were either required to discriminate (same/different) vowel pairs, to rate vowel "goodness" (first/second sound was a better exemplar of the vowel class), to discriminate pitch changes in the noise bursts, or to discriminate Gabor orientation changes. We obtained distinctly different AC activation patterns to identical sounds presented during the four task conditions. In particular, direct comparisons between the vowel tasks revealed stronger activations during vowel discrimination in the anterior and posterior superior temporal gyrus (STG), while the vowel rating task was associated with increased activations in the inferior parietal lobule (IPL). We also found that AC areas in or near Heschl's gyrus (HG) were sensitive to the speech-specific difference between a vowel prototype and nonprototype during active listening tasks. These results show that AC activations to speech sounds are strongly dependent on the listening tasks.

A randomized, controlled trial of tonsillectomy in periodic fever, aphthous stomatitis, pharyngitis, and adenitis syndrome

OBJECTIVE

We carried out a prospective, randomized, controlled trial to clarify the effect of tonsillectomy on the clinical course of periodic fever, aphthous stomatitis, pharyngitis, and adenitis (PFAPA) syndrome.

STUDY DESIGN

Twenty-six consecutive children (mean age 4.1 years) with at least 5 PFAPA attacks were recruited from 3 tertiary care pediatric hospitals during 1999-2003 and randomly allocated to tonsillectomy or follow-up alone. They were all followed up with symptom diaries for 12 months. Tonsillectomy was allowed after 6 months in the control group if the attacks recurred.

RESULTS

Six months after randomization all 14 children in the tonsillectomy group and 6/12 children in the control group (50%) were free of symptoms (difference 50%, 95% confidence interval 23% to 75%, P < .001). Tonsillectomy was performed on 5/6 of the patients in the control group who still had symptoms after 6 months. The remaining unoperated child in the control group had recurrences of the fever episodes throughout the follow-up, but the symptoms became less severe, and the parents did not choose tonsillectomy.

CONCLUSION

Tonsillectomy appeared to be effective for treating PFAPA syndrome. The fever episodes ceased without any intervention in half of the control subjects. We conclude that although the mechanisms behind this syndrome are unknown, tonsillectomy can be offered as an effective intervention for children with PFAPA.

Clinical "pneumococcal pneumonia" due to Moraxella osloensis: case report and a review

A previously healthy 6-y-old girl presented with a disease very similar to pneumococcal pneumonia. However, Moraxella osloensis was isolated by lung tap. The patient responded well to a course of parenteral penicillin. This is probably the first documented case of community-acquired pneumonia associated with this agent. Clinical isolates of M. osloensis are rare and its pathogenesis has not been delineated; however, a literature review suggests that the organism is more common than is generally recognized.

Recurrent urinary tract infections in infancy: relapses or reinfections?

Seventeen infants with an index episode of pyelonephritis caused by Escherichia coli were monitored for 18 months for recurrent urinary tract infections (UTIs). All the infants had at least 1 recurrent UTI caused by the same pathogen. Twenty-six recurrent UTI episodes were recorded. The 40 E. coli strains available were analyzed by multiplex polymerase chain reaction for 3 alleles (classes I-III) of the papG gene and by pulsed-field gel electrophoresis (PFGE) after genomial digestion by XbaI. Of the 17 index strains, 12 (71%) carried the papG gene; 67% of these strains had class II alleles. In recurrent UTI isolates, the papG-positive E. coli appeared in 16 (70%) of 23 isolates. The proportion of all recurrent isolates available that represented a strain previously encountered (indistinguishable or highly similar in PFGE) in the same infant was 65%. Our results suggest that most recurrent UTIs in infants are endogenous relapses rather than reinfections caused by new organisms.

Predominance of class II papG allele of Escherichia coli in pyelonephritis in infants with normal urinary tract anatomy

P-fimbrial genotypes of Escherichia coli strains and their possible association with urinary tract abnormalities were studied in infants with pyelonephritis. A total of 153 urinary E. coli strains were analyzed by polymerase chain reaction for class I, II, and III alleles of the pyelonephritis-associated adhesin gene papG. Strains with any class II papG alleles were found significantly more often in infants with normal anatomy and function or in infants with clinically insignificant abnormalities than they were in infants with significant abnormalities (90 of 119 vs. 14 of 34 infants; P<. 001). On the other hand, strains without any papG alleles were found significantly more often in infants with major urinary tract abnormalities (11 of 34 vs. 17 of 119 infants; P=.016). Our genotypic findings indicate that, especially in infants with a normal urinary tract, infection is caused by more-virulent E. coli than is present in infants without a normal urinary tract. This virulence could be due to expression of pyelonephritogenic P fimbriae by an infecting E. coli strain.

Searching for the prototypic eye genetic network: Sine oculis is essential for eye regeneration in planarians

We have identified a sine oculis gene in the planarian Girardia tigrina (Platyhelminthes; Turbellaria; Tricladida). The planarian sine oculis gene (Gtso) encodes a protein with a sine oculis (Six) domain and a homeodomain that shares significant sequence similarity with so proteins assigned to the Six-2 gene family. Gtso is expressed as a single transcript in both regenerating and fully developed eyes. Whole-mount in situ hybridization studies show exclusive expression in photoreceptor cells. Loss of function of Gtso by RNA interference during planarian regeneration inhibits eye regeneration completely. Gtso is also essential for maintenance of the differentiated state of photoreceptor cells. These results, combined with the previously demonstrated expression of Pax-6 in planarian eyes, suggest that the same basic gene regulatory circuit required for eye development in Drosophila and mouse is used in the prototypic eye spots of platyhelminthes and, therefore, is truly conserved during evolution.

Isolation and expression of a Pax-6 gene in the regenerating and intact Planarian Dugesia(G)tigrina

The Pax-6 gene encodes a transcription factor containing both a paired and a homeodomain and is highly conserved among Metazoa. In both vertebrates and invertebrates, Pax-6 is required for eye morphogenesis, development of parts of the central nervous system, and, in some phyla, for the development of olfactory sense organs. Ectopic expression of Pax-6 from insects, mammals, cephalopods, and ascidians induces ectopic eyes in Drosophila, suggesting that Pax-6 may be a universal master control gene for eye morphogenesis. Platyhelminthes are an ancient phylum, originating from the base of spiralian protostomes, that bear primitive eyes, consisting of a group of rhabdomeric photoreceptor cells enclosed in a cup of pigment cells. The analysis of Pax-6 and its expression pattern should provide insights into the ancestral function of Pax-6 in eye morphogenesis. We have identified the Pax-6 gene of the planarian Dugesia(G)tigrina (Platyhelminthes; Turbellaria; Tricladida). This gene shares significant sequence identity and conserved genomic organization with Pax-6 proteins from other phyla. Phylogenetic analysis indicates that it clusters with the other Pax-6 genes, but in the most basal position. DtPax-6 is expressed as a single transcript in both regenerating and fully grown eyes, and electron microscopy studies show strong expression in the perykarion of both photoreceptor and pigment cells. Very low levels of expression also are detectable in other body regions. Because a bona fide Pax-6 homolog so far has not been detected in diploblastic animals, we speculate that Pax-6 may be typical for triploblasts and that the appearance of additional Pax genes may have coincided with increasingly complex body plans.

Management of acute diarrhoea with low osmolarity oral rehydration solutions and Lactobacillus strain GG

Two hypotonic oral rehydration solutions with osmolarities of 224 mosmol/l (Na+ 60 mmol/l, glucose 84 mmol/l) and 204 mosmol/l (Na+ 60 mmol/l, glucose 64 mmol/l), respectively, and oral treatment with Lactobacillus GG were evaluated in a double blind trial in children aged 6-36 months hospitalised for acute diarrhoea. Early administration of Lactobacillus GG at the start of oral rehydration resulted in the shortest duration of diarrhoea, best weight gain, and fastest correction of acidosis. A reduced osmolarity oral rehydration solution (224 mosmol/l) combined with early administration of Lactobacillus GG is an effective treatment for acute diarrhoea in young children; further reduction of osmolarity may not be beneficial.

Bacteriotherapy with Lactobacillus reuteri in rotavirus gastroenteritis

BACKGROUND

Certain lactic acid bacteria may accelerate recovery from acute diarrhea. Lactobacillus reuteri is a commonly occurring Lactobacillus species with therapeutic potential in diarrhea.

DESIGN

Prospective, randomized, placebo-controlled trial in two hospitals.

METHODS

Children between 6 and 36 months of age admitted for rotavirus-associated diarrhea were randomized into three groups to receive either 10(10) or 10(7) colony-forming units (cfu) of L. reuteri or a matching placebo once a day for up to 5 days.

RESULTS

The main effect of L. reuteri was on the duration of watery diarrhea. The mean (+/-SD) duration of watery diarrhea after initiation of treatment was 2.5 (1.5) days in the placebo group (n = 25) vs. 1.9 (0.9) days in the small dosage (n = 20) and 1.5 (1.1) days in the large dosage (n = 21) L. reuteri recipients (P = 0.01). By the second day of treatment watery diarrhea persisted in 80% of the placebo, 70% of the small dosage and 48% of the large dosage L. reuteri recipients (P = 0.04, large dosage vs. placebo). Stool cultures for lactobacilli confirmed that administration of L. reuteri resulted in good colonization of the GI tract. The mean (+/-SD) of total Lactobacillus count 2 days after treatment initiation was 2.8 (1.6) log 10 cfu/g in the placebo group, 4.5 (2.0) log 10 cfu/g in the small dosage L. reuteri group and 6.1 (1.2) log 10 cfu/g in the large dosage L. reuteri group (P = 0.0004).

CONCLUSIONS

L. reuteri effectively colonized the gastrointestinal tract after administration and significantly shortened the duration of watery diarrhea associated with rotavirus. There was a correlation between the dosage of L. reuteri and the clinical effect.

Comparison of four different sampling methods for detecting pharyngeal carriage of Streptococcus pneumoniae and Haemophilus influenzae in children

Samples from 96 children with acute respiratory infection were obtained simultaneously with nasal, nasopharyngeal, and oropharyngeal swabs and by nasopharyngeal aspiration and were cultured on chocolate and blood agar plates. The rates of isolation of Streptococcus pneumoniae and Haemophilus influenzae detected by the four sampling methods were compared. Nasopharyngeal aspirates were optimal for the detection of both S. pneumoniae (isolation rate, 33%) and H. influenzae (isolation rate, 31%). When a nasopharyngeal aspirate is not available, such as for healthy children or children with no obtainable secretions, the nasopharyngeal swab seems optimal for the detection of both S. pneumoniae and H. influenzae among children younger than 13 months of age. Among older children, similarly, the nasopharyngeal swab seems optimal for the detection of S. pneumoniae; however, for H. influenzae, the oropharyngeal swab seems optimal.

Pneumococcal capsular antigen detection after enrichment culture: an alternative to culture methods in epidemiologic research

Bacterial culture of Streptococcus pneumoniae followed by serotyping is not always feasible under field conditions. Antigen detection methods could be an alternative, but they are associated with sensitivity problems. In an effort to improve their sensitivity, we introduced an enrichment phase before antigen detection and compared the results with direct bacterial culture, using nasopharyngeal swabs from 95 children with symptoms of acute respiratory infection. Antigen detection was performed by latex agglutination and counterimmunoelectrophoresis. Streptococcus pneumoniae was found in 29 (30%) of the samples by culture, and in 42 (44%) by antigen detection after enrichment, an excess of 45% over culture findings. This excess was shown to represent true positive samples since pneumococcal DNA could be detected by polymerase chain reaction in all 15 antigen-positive, culture-negative samples. Two culture-positive samples were antigen-negative; in one of these the bacteria were nonencapsulated. We conclude that for type-specific demonstration of S. pneumoniae, detection of pneumococcal antigen after an enrichment step is a sensitive method that can be applied for epidemiologic study purposes, e.g., in vaccine trials, in areas without ready access to a good microbiology laboratory.

Epidemiology of Kawasaki disease

In this paper we review the main epidemiologic characteristics of Kawasaki disease (KD) and summarize the results of a prospective incidence survey conducted in Finland from 1981 to 1992, supplemented with some previously unpublished data. The epidemiologic features of KD have been well established in studies conducted during the past 20 years. However, continuous surveillance of KD is important to maintain a high level of awareness of the disease and to detect possible new risk factors. Epidemiologic studies should also be focused on individuals who have had KD to ascertain the final outcome of the disease, including the possible risk of premature coronary atherosclerosis.

Randomised double blind trial of hypotonic oral rehydration solutions with and without citrate

Hypotonic oral rehydration salts solutions (ORS) have been proved to be better than isotonic solutions with respect to water absorption. To establish whether a base precursor is essential in the composition of a hypotonic ORS with improved absorption properties, a randomised double blind clinical trial was conducted comparing two formulas of hypotonic ORS, each with an osmolality of 224 mmol/l, with or without citrate, in a group of 107 children admitted to hospital with acute diarrhoea. The two solutions were effective in the correction of dehydration and there was no difference between the treatments in the duration of diarrhoea. The patients receiving the hypotonic ORS with citrate consumed less of the solution, however, and their metabolic acidosis was corrected earlier. It is concluded that citrate is clinically advantageous in a hypotonic ORS, but a hypotonic formula without a base precursor is also effective.

Kawasaki disease in Finland in 1982-1992

Data on patients suffering from Kawasaki disease have been collected prospectively in Finland since 1981. To ascertain the incidence, treatment and outcome in these patients the data were analysed for the 10-year period April 1982 to March 1992. Kawasaki disease was confirmed in 229 patients. The annual attack rate varied from 3.1 to 7.2 per 100,000 children below the age of 5 years. Their mean age was 3.9 years (range: 7 weeks to 39 years). 40% were under 2 years and 71% under 5 years of age. There was 1 adult patient. The male/female ratio was 1.5:1. Coronary artery lesions were found in 28 patients, 2 of whom died of myocardial infarction. Since April 1985, 132 patients (73%) have been treated with intravenous immunoglobulin. When treatment was begun before day 7 of the disease, coronary artery lesions were found in 5.5%; when begun between days 7 and 10, in 12%, and when begun after day 10, in 28% of the patients.

Antibodies against neutrophil cytoplasmic components in Kawasaki disease

The occurrence of antibodies against neutrophil cytoplasmic components in 39 children (23 boys, 16 girls, median age 2.0 years) with Kawasaki syndrome was studied. The conventional indirect immunofluorescence test (ANC-Ab) on alcohol-fixed neutrophils and two commercially available ELISA tests (ANCA-EIA and MPO-EIA) were employed to detect the antibodies. Fourteen (36%) of the 39 patients with Kawasaki disease had antibodies against neutrophil cytoplasmic components in at least one of the three tests used. Eleven patients were identified using the indirect immunofluorescence test. Five patients were positive in the MPO-EIA test and two additional patients in the ANCA-EIA test. The IF staining pattern was cytoplasmic in eight patients and perinuclear in three. The cytoplasmic staining pattern in patients with acute Kawasaki disease is different from that seen in patients with Wegener's granulomatosis. The occurrence of antibodies may assist in the diagnosis of some patients with Kawasaki disease, although neither the positivity itself nor the five different antibody profiles seem to have any other clinical relevance.

Serum cholesterol levels during and after Kawasaki disease

Serum total cholesterol and high-density lipoprotein (HDL) cholesterol concentrations were studied in paired sera from 23 patients (16 boys) with Kawasaki disease (KD) during acute illness and in 35 patients (21 boys) 5.4 to 7.7 years after KD. Total cholesterol and HDL cholesterol concentrations were significantly lower (paired t test, p = 0.0001) in samples taken within 30 days of the onset of illness (3.32 +/- 0.85 mmol/L (128 +/- 33 mg/dl) and 0.54 +/- 0.25 mmol/L (20.8 +/- 9.7 mg/dl) than in the second samples taken 2 to 16 months after onset of disease (4.16 +/- 0.93 mmol/L (161 +/- 35 mg/dl) and 1.24 +/- 0.35 mmol/L (47.2 +/- 13.9 mg/dl). The lowest total cholesterol levels were observed in samples taken 6 to 9 days after the onset of KD (p = 0.019). No correlations were seen between the highest erythrocyte sedimentation rate, C-reactive protein, or thrombocyte counts and the acute or convalescent cholesterol levels. In patients studied 5.4 to 7.7 years after recovery from KD, the mean total cholesterol concentrations were still lower than in healthy Finnish children. In girls the HDL cholesterol concentrations were similar, whereas 3 of the 18 boys studied had HDL cholesterol values more than 2 SDs below the mean for healthy boys. There was no correlation between the serum cholesterol concentrations and coronary artery abnormalities. These data lead us to infer that KD does not cause such permanent changes in cholesterol metabolism as to be considered a risk factor for atherosclerosis beyond that caused by the disease itself.

Anticardiolipin response in Kawasaki disease

Antibodies against cardiolipin are formed in many different infectious diseases, and high levels are associated with susceptibility to thrombosis, especially in patients with systemic lupus erythematosus. In view of the postulated infectious etiology of Kawasaki disease an its association with thrombosis, we have studied the occurrence of anticardiolipin antibodies in this disease. Serial serum specimens from 36 patients were tested, using a solid-phase enzyme immunoassay. A change of at least 0.3 optical density units between two consecutive specimens for at least one immunoglobulin class was observed in 47% of cases. Peak levels occurred one to two weeks after the onset of symptoms. Four patients developed coronary artery aneurysms, and they all showed a clear anticardiolipin response. Anticardiolipin antibodies might be one factor contributing to coagulation abnormalities in patients with Kawasaki disease.

Regeneration and pattern formation in planarians. III. that neoblasts are totipotent stem cells and the cells

In most regenerating systems, blastema cells arise by dedifferentiation of functional tissue cells. In is still debatable whether dedifferentiated cells or a undifferentiated cells, the neoblasts, are the main cells. Moreover, it is unclear whether in the intact neoblasts are quiescent cells ‘reserved’ for serve as functional stem cells of all differentiated uncertainties partly stem from the failure to conventional labelling methods neoblasts from Here we describe a new approach to these problems regenerative and stem cell capabilities of purified differentiated cells when introduced, separately, into hosts. Introduction of neoblasts led to resumed blastema formation, and extended or complete survival differentiated cells, in contrast, never did so. neoblasts can be qualified as totipotent stem cells of blastema cells, while dedifferentiation does not either in intact or regenerating organisms. In strengthen the idea that different types of formation, linked to the tissular complexity of the present in the animal kingdom.

Regeneration and pattern formation in planarians. II. and role of cell movements in blastema formation

In planarians, blastema cells do not divide, and growth blastema is thought to result from the steady wound epithelium, of undifferentiated cells produced in the stump. However, whether these cells come only sources or whether cells placed far from the wound can participate, after long-range migrations, in the still uncertain. To study this problem, we have parameters of the process of regeneration: cell growth; number of cells produced by mitosis in the wound (postblastema); and rates of movement undifferentiated cells using grafting procedures with chromosomal markers. The results show that: (1) cells area spread (move) at higher rates than cells placed (90–140_mday-1 versus 40–50_mday-1); (2) cells than 500_m from the wound boundary are hardly 5-day-old blastemata; and (3) the number of cells within a 200–300_m postblastema area around the wound explain, provided their rates of movement are taken increasing number of blastema cells. From this, it is blastema cells in planarians originate from local mitotic activity jointly with local cell movement postblastema area around the wound match the blastema cells during regeneration. The implications for blastema growth and pattern formation mechanisms

Elevated circulating tumor necrosis factor-alpha in patients with Kawasaki disease

The mechanism of vascular injury in Kawasaki disease (KD) is unclear. Recent studies suggest a role for circulating antibodies that are cytotoxic for endothelial cell antigens inducible by cytokines. Tumor necrosis factor-alpha (TNF, cachectin) is a monocyte- or macrophage-derived cytokine that has an important role as an effector molecule in various inflammatory processes. To study the possible involvement of TNF in KD, we measured the levels of circulating TNF in 39 patients with KD at various stages of the disease by using a newly developed sensitive radioimmunoassay. The TNF levels in sera from the acute and subacute phases of the disease were significantly (p less than 0.001) higher than in sera taken in the convalescence phase or in sera from children without inflammatory disease. In all patients from whom serial samples were available, the TNF level was higher during the acute and subacute phases than during convalescence. Coronary aneurysms developed in four of the patients, and these patients were among those who had the highest levels of circulating TNF during the acute and subacute phase (51.1 +/- 13.6 pg/ml (mean +/- SD) vs 30.4 +/- 15.8 pg/ml in patients without coronary aneurysms; p less than 0.001). No differences in circulating TNF levels were observed between patients who received as treatment aspirin plus intravenous immunoglobulin and those who received aspirin alone. The results show that the levels of circulating TNF are increased in acute KD and support the hypothesis that this cytokine may be involved in the pathogenesis of the vascular injury in KD.

Kawasaki disease: monitoring of circulating immune complexes

We followed the levels of circulating immune complexes (CIC) in 27 patients with Kawasaki disease (KD) from the acute stage of the disease through convalescence, using the test for platelet-reactive IgG-IC, and C1q-binding and conglutinin-binding enzyme immunoassays. CIC were detected by one or more techniques in all but one patient. Positive results were obtained most often with the test for platelet-reactive IgG-IC. Measurement of complement components C3 and C4 in 14 patients revealed an increase in C3 levels during the first few weeks of the disease and normal levels of C4. The blood platelet count correlated directly with the level of platelet-reactive IgG-IC. The highest levels of CIC were found during weeks 3 through 7 after the onset of disease. Measurement of CIC is, however, not applicable to the clinical follow-up of patients with KD.

Outbreak of Kawasaki syndrome in Finland

During a ten-month period from June 1981 to March 1982 83 patients with Kawasaki syndrome were diagnosed in Finland. The attack rate was 26/100 000 children under five years of age, corresponding to an annual attack rate of 31/100 000 children under five years. The course of the outbreak suggested geographic spreading. 20% of the patients had clinical and ECG evidence of carditis, and ECG abnormalities were found in 59% of the patients. One patient died from a ruptured coronary aneurysm. Neurologic manifestations were seen in 10% of the patients. This is the first reported outbreak of Kawasaki syndrome outside Japan, Korea and the United States of America.