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In stream ecosystems, waterfalls intercept the fluvial continuum and limit the dispersion of aquatic organisms. However, the barrier effect may be minimized or absent for insects whose life cycle is not restricted to the aquatic environment (i.e., winged adults), such as the orders Ephemeroptera, Plecoptera and Trichoptera (EPT). In this study, we investigated EPT diversity (abundance, richness, and composition) in savanna headwater streams (Cerrado Domain, Brazil) to investigate the hypothesis that large waterfalls have little effect on instream assemblage structure. During 2017 and 2018, we sampled EPTs and measured environmental conditions at reaches adjacent (downstream and upstream) to waterfalls (5 to 70 m high). We collected 2532 immature specimens of 33 genera, including the first record of 14 genera of Ephemeroptera, 11 Trichoptera, and three Plecoptera for the Tocantins State. Hydro-geomorphic and streambed conditions varied among sites, but they were not related to the presence of waterfalls. Assemblage structure was similar between downstream and upstream reaches, with no significant difference in taxa richness, abundance, and composition. This pattern was consistently observed considering all data combined, and each order separately. These results support the hypothesis that physical barriers have weak effects on EPT assemblages at small spatial scales, where strong dispersal and habitat similarity probably homogenizes the structure of local assemblages in stream corridors adjacent to large waterfalls. The study provides important information about factors driving the distribution of biodiversity in savanna streams, which are relevant to support conservation and management plans in the Brazilian Cerrado.

In this article, we describe the morphologic and immunophenotypic features of 75 cases of pediatric anaplastic large cell lymphoma (ALCL). According to the World Health Organization classification, 49 cases were common subtype ALCL, and respectively, 3, 6, and 17 cases were small cell, lymphohistiocytic, or mixed histologic variants. Anaplastic lymphoma kinase positivity was detected in 90.7% of the tumors and, using a panel of 9 T-cell surface markers, 88% could be assigned to the T-cell lineage. A molecular analysis for the T-cell receptor γ(TCR- γ) and the heavy chain of the immunoglobulin H rearrangements was performed on 6/9 ALCLs with a null immunophenotype, and a TCR clonal pattern was detected in 5/6 cases. In addition, 94.1% were immunoreactive for 1 or more cytotoxic proteins (Tia1, granzyme B, or perforin), and 15% expressed CD56. Clusterin, CD83, and Pax5, respectively, expressed in 91.3%, 1.7%, and 0% of the ALCLs, were useful biomarkers for the differential diagnosis with Hodgkin's lymphomas.

The authors report the clinical and molecular findings in eight patients with hyperornithinemia, hyperammonemia, and homocitrullinuria (HHH) syndrome. The most consistent neurologic finding was spastic paraparesis, seen in five of the eight patients. However, all showed signs of pyramidal tract involvement. A broad spectrum of pathogenetic mutations (including missense, nonsense, splice site, insertion, and deletions) were identified in the ORNT1gene.

To describe clinical and neuropathologic studies and linkage analysis on two sisters with a severe form of leukodystrophy.

We present a undescribed condition in a girl who died at 8 years of hypertrophic cardiomyopathy. Muscle and endomyocardial biopsies disclosed a selective loss of thick filaments ultrastructurally. In muscle biopsy histochemical abnormalities of myofibrillar AT-Pase were confined to type 1 fibres. Gel electrophoresis of muscle homogenate showed no qualitative abnormalities of slow and fast myosin heavy chains (MHC) and light chains, and the amount of the different myosin isozymes was in agreement with histochemical myofibrillar ATPase findings. The pathogenetic mechanisms have not been elucidated in this case but we suspect an abnormality of theß-cardiac MHC gene, the only gene expressed in the heart and in type 1 skeletal muscle fibres.

The clinical, morphological and biochemical findings of a sporadic case, showing accumulation of desmin-type intermediate filaments in skeletal muscle and myocardium are described. Desmin storage was demonstrated by immunofluorescence, sodium dodecyl sulfate gel electrophoresis and two-dimensional gel electrophoresis. These findings are in agreement with those of Rappaport et al. (FEBS Lett. 231:421–425, 1989). A sensory-motor polyneuropathy was established by electrophysiological studies and, ultrastructurally, intramuscular nerves showed accumulation of neurofilaments and neurotubules with formation of axonal spheroids. These findings are discussed considering all previous reports with related conditions.

Lymphangiomas are unusual benign neoplasms originating from the lymphatic system that are rarely found in the scrotal area. Ultrasound and magnetic resonance findings in a 4-year-old boy with a scrotal lymphangioma are presented. There was no recurrence after surgical excision.

Fibrous hamartomas of infancy and childhood are rare benign tumors. The clinical and morphological features of these lesions can be different according to the age at onset. Although the most common localizations are the shoulders, axillas, and upper arms, these lesions may develop in unusual sites such as the scrotum. The authors report a 13-month-old child with a fibrous hamartoma in the scrotum, which was excised. At 1-year follow-up there was no sign of local recurrence or distant disease. The clinical and histological features of the disease are described in order to facilitate correct diagnosis and avoid inadequate therapy.

Purpose: In bladder exstrophy and to a lesser extent in epispadias th e muscular tissue in the bladder wall may often be replaced by collagen. The aim of our study was to assess the relative changes of smooth muscle versus connective tissue in patients with the exstrophy-epispadias complex. Materials and Methods: Nine full thickness detrusor biopsies from children with the exstrophy-epispadias complex were analyzed. Biopsies were stained with the Masson trichrome method to differentiate muscular tissue from collagen. At X50 magnification using image software for computerized morphometry the areas of smooth muscle and collagen were measured and expressed as a percent. As controls, detrusor biopsies from 8 children with unilateral obstructive megaureter or ectopic ureter were analyzed using the same method. Results: The average rates of smooth muscle in children with the exstrophy-epispadias complex were 7, 19.3 and 31.5 percent, respectively, in newborns, and before and after bladder neck reconstruction. In controls the rate average 56.5 percent. Conclusions: The ratio of smooth muscle-to-connective tissue increases from the newborn period to puberty in the exstrophy-epispadias complex. After staged reconstruction is completed this ratio remains below normal, although it is increased. Such a change may represent a histological marker of the inadequate volume increase of some of these bladders.

A case of brown tumor of hyperparathyroidism in a young girl with a long history of chronic renal failure and hemodialysis therapy is reported. The diagnosis can be reached with the aid of the classic skeletal radiological sign which address the evaluation of both CT and MR imaging.

PSYCHOLOGICAL stimulation affects the normal cardiac function in man, causing tachycardia and vascular spasms; if these continue for a sufficiently long time, they may become, according to some workers, very important factors in the pathogenesis of some cardiovascular diseases1. We have studied the effect of repeated stimulation on the hearts of laboratory animals.

THE amounts of adenosine triphosphate, creatine phosphate and inorganic phosphorus in the heart of hyperthyroid animals are below normal. These amounts are restored to about the normal level by administration of adenosine triphosphate, whereas with cocarboxylase and organic phosphates restoration is incomplete1. Moreover, thyroxin intoxication reduces the creatine content of the skeletal muscle and the rate of creatine synthesis by liver2.

THYROXINE can uncouple oxidation and phosphorylation in animal tissues1, and it has been shown that this phenomenon occurs in the heart muscle of hyperthyroid animals, where a depression in adenosine triphosphate, phosphocreatine and inorganic phosphorus content is observed2. We have investigated the effects of injecting certain compounds concerned with phosphorylation on the levels of these substances in the heart muscle of rats treated with thyroxine.

Aims: To determine the role of surfactant-related gene anomalies in neonatal/infantile interstitial lung disease.Methods: 22 infants >32weeks/< 1year with unexplained progressive alveolar/interstitial lung disease. SP-B, SP-C and ABCA3 sequencing. Optical (OM) and electronical (EM) microscopy of biopsy/autopsy lung tissue. Surfactant proteins immunofluorescence.Results: 13/22 infants (59.1%) had lamellar bodies (LB) ultrastructural abnormalities suggesting genetic surfactant deficiency. Eleven infants (50.0%) carried ABCA3 mutations.-Five (22.7%) had bi-allelic mutations (2 homozygote frameshift, 3 double heterozygote missense), showing small, dense LB with 1-2 denser cores and no normal LB on EM.-Five (22.7%) had a single mutation (four missense, one intron), showing a mix of small and normal LB plus multivesicular bodies (MVB) on EM. On immunofluorescence, one had cytoplasmic mislocation of TTF-1 despite normal TTF-1 gene sequence, one had altered cleavage of proSP-B into SP-B, and one had reduced/misplaced alveolar capillaries.-One infant (4.5%) carried a heterozygote SP-C mutation, plus a synonymous ABCA3 mutation, showing large, empty LB lacking normal surfactant layers on EM.-One infant (4.5%) with normal LB + MVB had a heterozygote SP-B mutation.-One infant (4.5%) with small dense LB (similar to homozygote ABCA3 mutants) had no mutation identified.In the 9 remaining infants (40.9%), one had alveolar proteinosis, one had COX-deficiency, one had Niemann-Pick C disease, two had idiopathic pulmonary fibrosis, four remained cryptogenetic.Conclusions: ABCA3 mutations are the most frequent abnormality. Although EM is indicative in most (92%) cases, molecular mechanisms are elusive in >50% of cases, likely involving complex, multiple surfactant-related gene interactions.

Background: Besides surfactant protein B (SP-B), respiratory distress syndrome in term neonates is associated to mutations of ABCA3, a gene encoding a type II pneumocyte protein essential for intracellular surfactant metabolism.Study goal: To correlate mutations in surfactant-related genes with specific tissue/cell structural anomalies and alterations of surfactant-related protein expression.Methods: 4 neonates with primary, progressive respiratory failure unresponsive to exogenous surfactant. Optical microscopy (OM) on formalin-fixed lung biopsy: HE, PAS, Masson trichrome; immunohistochemestry with CD45, CD68, SP-B and SP-C antibodies; immunofluorescence with ABCA3 antibody. Electron microscopy (EM) on Karnowsky-fixed ultrathin sections. Direct sequencing of SP-B, SP-C and ABCA3 genes on PCR-amplified genomic DNA.Results: Case 1, 2 and 3 were term-born infants dead at 68, 48 and 55d; case 4 was a 32-week preterm alive with severe respiratory failure at 4 months. OM: All cases showed marked interstitial thickening with monocyte infiltrate, type II pneumocyte hyperplasia, intra-alveolar proteinaceous material and macrophage accumulation. SP-B and SP-C protein expression was normal. ABCA3, abundantly expressed with a cytoplasmic granular pattern in normal subjects, was either absent (1), low with a diffuse cytoplasmic pattern (2,4), or apparently normal (3). EM: In all cases, type II pneumocyte lamellar bodies appeared much smaller than normal and filled with homogenous material with an eccentric, denser inclusion. Pseudomyelin structures, corresponding to intracellular surfactant, were virtually absent. Molecular genetics: SP-B and SP-C gene sequences were normal. In the ABCA3 gene, homozygous frameshift (1) or double heterozygote missense mutations (2,3,4) were found.Conclusions: ABCA3 deficiency is a rare but relevant cause of progressive respiratory failure in newborns. Various recessive mutations are associated with this phenotype, leading in most cases to absent or aberrant ABCA3 protein expression and/or function. Whereas OM may be nonspecific, EM shows typical anomalies of the lamellar bodies that may contribute to early diagnosis.