The functional role of temperate forest understorey vegetation in a changing world.

Temperate forests cover 16% of the global forest area. Within these forests, the understorey is an important biodiversity reservoir that can influence ecosystem processes and functions in multiple ways. However, we still lack a thorough understanding of the relative importance of the understorey for temperate forest functioning. As a result, understoreys are often ignored during assessments of forest functioning and changes thereof under global change. We here compiled studies that quantify the relative importance of the understorey for temperate forest functioning, focussing on litter production, nutrient cycling, evapotranspiration, tree regeneration, pollination and pathogen dynamics. We describe the mechanisms driving understorey functioning and develop a conceptual framework synthesizing possible effects of multiple global change drivers on understorey-mediated forest ecosystem functioning. Our review illustrates that the understorey's contribution to temperate forest functioning is significant but varies depending on the ecosystem function and the environmental context, and more importantly, the characteristics of the overstorey. To predict changes in understorey functioning and its relative importance for temperate forest functioning under global change, we argue that a simultaneous investigation of both overstorey and understorey functional responses to global change will be crucial. Our review shows that such studies are still very scarce, only available for a limited set of ecosystem functions and limited to quantification, providing little data to forecast functional responses to global change.

Revision of Acrochordonoposthia Reisinger, 1924 (Rhabditophora, Typhloplanidae, Protoplanellinae) with the description of one new species.

An overview of the morphology, taxonomy and distribution of all known species of the rhabdocoel taxon Acrochordonoposthia is provided. One new species A. vandeputae n. sp. is described from Graz (Austria). This new species can easily be distinguished from its congeners by the morphology of its copulatory organ, which contains a straight cirrus lined with spines. All species of Acrochordonoposthia are compared with one another, and an updated identification key is provided.

Long-term cattle grazing shifts the ecological state of forest soils.

Cattle grazing profoundly affects abiotic and biotic characteristics of ecosystems. While most research has been performed on grasslands, the effect of large managed ungulates on forest ecosystems has largely been neglected. Compared to a baseline seminatural state, we investigated how long-term cattle grazing of birch forest patches affected the abiotic state and the ecological community (microbes and invertebrates) of the soil subsystem. Grazing strongly modified the soil abiotic environment by increasing phosphorus content, pH, and bulk density, while reducing the C:N ratio. The reduced C:N ratio was strongly associated with a lower microbial biomass, mainly caused by a reduction of fungal biomass. This was linked to a decrease in fungivorous nematode abundance and the nematode channel index, indicating a relative uplift in the importance of the bacterial energy-channel in the nematode assemblages. Cattle grazing highly modified invertebrate community composition producing distinct assemblages from the seminatural situation. Richness and abundance of microarthropods was consistently reduced by grazing (excepting collembolan richness) and grazing-associated changes in soil pH, Olsen P, and reduced soil pore volume (bulk density) limiting niche space and refuge from physical disturbance. Anecic earthworm species predominated in grazed patches, but were absent from ungrazed forest, and may benefit from manure inputs, while their deep vertical burrowing behavior protects them from physical disturbance. Perturbation of birch forest habitat by long-term ungulate grazing profoundly modified soil biodiversity, either directly through increased physical disturbance and manure input or indirectly by modifying soil abiotic conditions. Comparative analyses revealed the ecosystem engineering potential of large ungulate grazers in forest systems through major shifts in the composition and structure of microbial and invertebrate assemblages, including the potential for reduced energy flow through the fungal decomposition pathway. The precise consequences for species trophic interactions and biodiversity-ecosystem function relationships remain to be established, however.

Pathways for Novel Epidemiology: Plant-Pollinator-Pathogen Networks and Global Change.

Multiple global change pressures, and their interplay, cause plant-pollinator extinctions and modify species assemblages and interactions. This may alter the risks of pathogen host shifts, intra- or interspecific pathogen spread, and emergence of novel population or community epidemics. Flowers are hubs for pathogen transmission. Consequently, the structure of plant-pollinator interaction networks may be pivotal in pathogen host shifts and modulating disease dynamics. Traits of plants, pollinators, and pathogens may also govern the interspecific spread of pathogens. Pathogen spillover-spillback between managed and wild pollinators risks driving the evolution of virulence and community epidemics. Understanding this interplay between host-pathogen dynamics and global change will be crucial to predicting impacts on pollinators and pollination underpinning ecosystems and human wellbeing.

Nail-patella syndrome, infantile nephrotic syndrome: complete remission with antiproteinuric treatment.

A girl, second child of healthy parents, was referred to the Renal Unit at the age of 9 months with haematuria (230 RBC/microl) and proteinuria (2.4 g/l). Serum creatinine was normal (0.25 mg/dl), albumin low (34 g/l) and cholesterol elevated (223 mg/dl). Physical examination showed bilateral webbing of the elbows, equinovarus of both feet and absent patellae. The clinical diagnosis of nail-patella syndrome was confirmed by demonstrating a splice mutation in the intron 5 (750 + 1 G>A) of the LMX1B gene. Treatment with enalapril for 2 years (0.1-1 mg/kg per day) did not bring about any change in urinary protein excretion. However, enalapril (1 mg/kg per day) associated with losartan (1 mg/kg per day) resulted in complete remission (proteinuria 140 mg/24 h) at the age of 7 years.

GNAS defects identified by stimulatory G protein alpha-subunit signalling studies in platelets.

CONTEXT: GNAS is an imprinted region that gives rise to several transcripts, antisense transcripts, and noncoding RNAs, including transcription of RNA encoding the alpha-subunit of the stimulatory G protein (Gsalpha). The complexity of the GNAS cluster results in ubiquitous genomic imprints, tissue-specific Gsalpha expression, and multiple genotype-phenotype relationships. Phenotypes resulting from genetic and epigenetic abnormalities of the GNAS region include Albright's hereditary osteodystrophy, pseudohypoparathyroidism types Ia (PHPIa) and Ib (PHPIb), and pseudopseudohypoparathyroidism (PPHP). OBJECTIVE: The aim was to study the complex GNAS pathology by a functional test as an alternative to the generally used but labor-intensive erythrocyte complementation assay. DESIGN AND PATIENTS: We report the first platelet-based diagnostic test for Gsalpha hypofunction, supported by clinical, biochemical, and molecular data for six patients with PHPIa or PPHP and nine patients with PHPIb. The platelet test is based on the inhibition of platelet aggregation by cAMP, produced after Gsalpha stimulation. RESULTS: Platelets are easily accessible, and platelet aggregation responses were found to reflect Gsalpha signaling defects in patients, in concordance with the patient's phenotype and genotype. Gsalpha hypofunction in PHPIa and PPHP patients with GNAS mutations was clearly detected by this method. Mildly decreased or normal Gsalpha function was detected in patients with PHPIb with either an overall or exon 1A-only epigenetic defect, respectively. Platelet Gsalpha expression was reduced in both PHPIb patient groups, whereas XLalphas was up-regulated only in PHPIb patients with the broad epigenetic defect. CONCLUSION: The platelet-based test is a novel tool for establishing the diagnosis of Gsalpha defects, which may otherwise be quite challenging.

Schimke immunoosseous dysplasia: suggestions of genetic diversity.

Schimke immunoosseous dysplasia (SIOD), which is characterized by prominent spondyloepiphyseal dysplasia, T-cell deficiency, and focal segmental glomerulosclerosis, is a panethnic autosomal recessive multisystem disorder with variable expressivity. Biallelic mutations in switch/sucrose nonfermenting (swi/snf) related, matrix-associated, actin-dependent regulator of chromatin, subfamily a-like 1 (SMARCAL1) are the only identified cause of SIOD. However, among 72 patients from different families, we identified only 38 patients with biallelic mutations in the coding exons and splice junctions of the SMARCAL1 gene. This observation, the variable expressivity, and poor genotype-phenotype correlation led us to test several hypotheses including modifying haplotypes, oligogenic inheritance, or locus heterogeneity in SIOD. Haplotypes associated with the two more common mutations, R820H and E848X, did not correlate with phenotype. Also, contrary to monoallelic SMARCAL1 coding mutations indicating oligogenic inheritance, we found that all these patients did not express RNA and/or protein from the other allele and thus have biallelic SMARCAL1 mutations. We hypothesize therefore that the variable expressivity among patients with biallelic SMARCAL1 mutations arises from environmental, genetic, or epigenetic modifiers. Among patients without detectable SMARCAL1 coding mutations, our analyses of cell lines from four of these patients showed that they expressed normal levels of SMARCAL1 mRNA and protein. This is the first evidence for nonallelic heterogeneity in SIOD. From analysis of the postmortem histopathology from two patients and the clinical data from most patients, we propose the existence of endophenotypes of SIOD.

Notes on some enigmatic taxa of limnoterrestrial rhabdocoels, with the description of two new species.

Six taxa of limnoterrestrial rhabdocoels are discussed, two of them, both belonging to Typhloplanidae Graff, 1905, are new to science. Adenoplea reisingeri n. sp. can be distinguished from its congeners by the absence of a separate seminal receptacle, the presence of a copulatory bursa and the fact that it has an unarmed copulatory organ. Carcharodopharynx schlitzensis n. sp. can be distinguished from C. arcanus (Reisinger, 1924) Poche, 1926, the only other species within the genus, by the fact that the cirrus bears spines. For four other taxa: Adenoplea perigraptopera Reisinger, 1924, A. meridionalis Kolasa, 1981, C. arcanus (Reisinger, 1924) Poche, 1926 and Archivortex silvestris Reisinger, 1924, new data on morphology and distribution are provided. Neotypes are designated for A. perigraptopera and C. arcanus.

Acute renal failure in childhood.

The definition of acute renal failure is a sudden reduction in renal function of at least 50 percent and is characterised by rising serum levels of waste products such as urea and creatinine, by disturbed water and electrolyte metabolism and changes in the amount or composition of the urine. The clinical manifestations are extremely variable, there are very many causes and the outcome depends mainly on the underlying condition, which is either in the kidneys or in the body as a whole. This paper will discuss the pathophysiology of acute renal failure and the aetiology including prerenal, renal and postrenal causes. Clinical findings, diagnosis and treatment will be discussed and complications of this life-threatening condition highlighted. The final part of the paper deals with the prognosis of acute renal failure.

A novel mutation in the complement regulator clusterin in recurrent hemolytic uremic syndrome.

A novel heterozygous mutation in the clusterin gene, nucleotide position A1298C (glutamine>proline Q433P), was detected in exon 7 of a child with recurrent hemolytic uremic syndrome (HUS). The same mutation was found in the child's two siblings and mother but not in 120 controls. In addition, a previously described heterozygous mutation was detected in the gene encoding membrane cofactor protein (MCP) causing a 6 base-pair deletion 811-816delGACAGT in exon 6. It was found in the patient, both siblings and the father. One sibling had recovered from post-streptococcal glomerulonephritis. Clusterin levels in the patient, siblings and parents were normal as was the migration pattern in a gel. Patient serum induced C3 and C9 deposition on normal washed platelets, and platelet activation, as detected by flow cytometry. The same phenomenon was found in serum taken from the siblings and the mother but not in the sample from the father and controls. Addition of clusterin to patient serum did not inhibit complement activation on platelets. The Q433P mutant, in isolated form, was further studied by binding to the components of the terminal complement complex. The mutant did not bind to C5b-7 that was immobilized onto a BIAcore chip, whereas wild-type clusterin did, indicating that the mutation could lead to defective inhibition of formation of the membrane attack complex under these conditions. Hemolysis of rabbit erythrocytes was inhibited by wild-type clusterin but not by the mutant. Mutated clusterin could thus not prevent assembly of the membrane attack complex on platelets and erythrocytes.

The neurogenic bladder: introducing four contributions.

Neurogenic bladder dysfunction in children is frequently seen in patients with meningomyelocele (MMC). The disorder carries a high risk for all kinds of complications, with renal damage being the most important. More than 95% of MMC patients have a neurogenic bladder, the paramount manifestation of which is a disturbed coordination between detrusor and sphincter muscles. This vesicourethral dysfunction leads to defective filling and emptying of the urinary bladder. Voiding at will is almost never possible. According to the location and extent of the neural tube lesion, patients have either an atonic or a hypertonic pelvic floor and either an atonic or a hypertonic detrusor, leading to four classic combinations. Hypertonic sphincter and detrusor hyperactivity lead to the most dangerous form of neurogenic bladder, referred to as the "unsafe" bladder. The presence of residual urine in a high-pressure container causes either decompensation of the detrusor with vesicoureteral reflux or deterioration of the bladder wall with hypertrophy and stiffness resulting in uterovesical obstruction. The subsequent insufficient drainage of the upper urinary tract leads to decompensation of the ureters and finally to chronic renal disease, the process being accelerated by urinary tract infections. The aim of treatment is to restore as much as possible both essential functions: urine storage and timely emptying of the reservoir. What should and can be achieved is a more or less adequate, low-pressure, functional capacity of the bladder that is emptied as completely as possible by clean intermittent catheterization (CIC). MMC leads to the prototype of neurogenic bladder in childhood. What we know and what we do for MMC patients can roughly be applied to all other forms of neurogenic bladder, either congenital or acquired.

Renal outcome of children with one functioning kidney from birth. A study of 99 patients and a review of the literature.

In patients with a single functioning kidney, renal function was assessed at regular intervals over a period of 10 years. Serum creatinine, glomerular filtration rate (GFR), blood pressure, and urinary protein-creatinine ratio were assessed at the age of 2, 5 and 10 years. Between January 1980 and December 2005, 99 such patients were diagnosed in the first year of life. They were divided into three groups: A, patients with multicystic kidney disease and a normal contralateral kidney (n = 36); B, patients with a normal solitary kidney without uropathy (n = 20); and C, patients with obstructive uropathy and one nonfunctioning kidney (n = 43). Serum creatinine levels increased significantly with increasing age in every group. In group C, serum creatinine was significantly elevated compared with group A in all age categories (p = 0.043, p = 0.019, p = 0.001 respectively). Median figures of GFR remained within normal limits over the 10-year period. GFR was significantly lower in group C compared with group A (p = 0.001, p = 0.009, p = 0.019 respectively) and B in all age categories (p = 0.013, p = 0.002, p = 0.016 respectively). There were no changes in blood pressure over time and no differences among the three groups were observed. At the age of 10 years, the patients in group C had a significantly higher median urinary protein-creatinine ratio (p = 0.022) than those in groups A and B. There was also an increasing level of proteinuria with increasing age in group C (p = 0.002). In conclusion, renal function was stable over time in all patients, but children with obstructive uropathy have a lower median GFR and higher serum creatinine level for the whole study period. Hypertension was exceptionally observed in group C, with obstructive uropathy, as was an elevated urinary protein-creatinine ratio.

Threading through the mizmaze of Bartter syndrome.

The story, described here in detail, started in 1962 with the publication of a seminal paper by Frederic Bartter et al. in the December issue of the American Journal of Medicine. The authors reported two pediatric patients with hitherto undescribed features, namely growth and developmental delay associated with hypokalemic alkalosis and normal blood pressure despite high aldosterone production. It soon became clear that this condition was not so exceptional. The syndrome named after Bartter was actually identified in children as well as in adults, females as well as males and in all five continents. It took almost four decades to clarify the exact nature of the disease. Bartter disease is an autosomal recessive disorder with four genotypes and mainly two phenotypes. Moreover, there are acquired secondary forms of Bartter syndrome as well as pseudo-Bartter syndromes. The history demonstrates the power of genetics but also illustrates the fundamental and irreplaceable contributions from nephrologists and renal physiologists.

Epidemiology, clinical presentation, and pathophysiology of atypical and recurrent hemolytic uremic syndrome.

Hemolytic uremic syndrome (HUS) includes a heterogeneous group of hemolytic disorders. Among the identified causes of HUS are infections, particularly infections with Shiga toxin-producing ESCHERICHIA COLI (STEC), complement disorders, and disorders interfering with the degradation of von Willebrand factor (VWF). Other causes for atypical HUS include the cobalamin metabolism; pregnancy/hemolysis, elevated liver enzymes, and low platelets syndrome (HELLP); drugs; and other disorders (e.g., systemic diseases appearing as HUS, such as systemic lupus erythematosus and rejection after transplantation). The group not related to STEC is often also called atypical HUS. Most of the occurrences of infectious HUS have only one episode. Recurrent episodes (recurrent HUS) have strong relationships to diseases of the complement system. In these two subgroups the prognosis is poor, with severe renal insufficiency, together with the need for renal replacement therapy. Severe arterial hypertension is common. Treatment options are limited. To better define this group of patients, the European Society for Pediatric Nephrology supported an initiative to develop a European HUS registry. In this registry, 167 patients were acquired; 73 were female (43.8%). The year of onset of the disease ranged from 1974 to 2005. The prevalence of atypical HUS/recurrent HUS can be calculated as 3.3 per million child population (< 18 years). Underlying disorders included factor H, factor I, MCP-1, pneumococci, and von Willebrand factor disturbances. In 33 patients at least one renal transplantation was performed (total, 55 kidneys); 18% were successful and 73% demonstrated recurrence or thrombosis. Treatment options were plasma substitution or plasmapheresis. Despite continued efforts, transplantation is not recommended at present for these patients. Living-related transplantation should be abandoned. New therapeutic strategies are urgently needed.

Renal biopsy 2-9 years after Henoch Schönlein purpura.

Twelve children and adolescents with classical Henoch-Schönlein purpura (HSP) underwent renal biopsy 2-9 years later. The clinical course was favorable in 10 of the patients who received only supportive treatment. Two patients with a prolonged course, characterized by marked hematuria and proteinuria, were given steroids and azathioprine first and mycophenolate mofetil later. At the time of biopsy, 4 patients did not have any urinary abnormalities, 6 had hematuria and/or mild proteinuria, and 2 had proteinuria >1 g/24 h. Renal histology showed mild lesions on light microscopy. Immunohistochemistry disclosed mesangial IgA in 8 of the 12 patients. In percentages, this is a proportion of 66.6 with 95% exact confidence limits of 34.9-90.1. In this small series of selected former HSP patients, the majority had IgA nephropathy years after the initial vasculitis episode. This indicates that some patients with apparently completely healed HSP have a chronic glomerular condition that possibly means protracted disease and certainly indicates the need for careful follow-up.

A girl with rickets and nephrocalcinosis.

A 5-year-old girl presented with short stature. She was found to have rickets due to renal phosphate wasting and nephrocalcinosis. Serum parathyroid hormone was suppressed, 25-OH vitamin D was within the normal range, and 1,25-(OH)(2 )vitamin D was elevated. In addition, she had hypercalciuria, proteinuria, which was partially tubular in origin, and a reduced glomerular filtration rate of 58 ml/min per 1.73 m(2). Treatment with phosphate supplements resulted in healing of the rickets and normalization of the serum 1,25-(OH)(2 )vitamin D level. This patient is an example of hypercalciuric rickets, most likely due to an inherited disorder of phosphate metabolism. Hypercalciuric rickets can be inherited as an autosomal recessive as well as autosomal dominant trait.

Enalapril in children with Alport syndrome.

Ten pediatric patients with Alport syndrome received enalapril for 5 years. There were nine boys. Eight patients have the X-linked form of the disease and two the autosomal recessive form. The median age at the start of treatment was 10.25 years. Only one patient was hypertensive. The starting dose of enalapril was 0.05 mg/kg; the target dose was 0.5 mg/kg per day. The median dose given effectively was 0.24, 0.37, 0.45, 0.43, and 0.49 mg/kg per day at years of study 1, 2, 3, 4, and 5, respectively. The median urinary protein/creatinine ratio was 1.58 g/g (range 0.49-4.60) before treatment. This decreased to 0.98, 1.09, 1.35, 1.11, and 1.38 g/g after 1, 2, 3, 4, and 5 years, respectively. The median creatinine clearance at baseline was 100 ml/min per 1.73 m2 (range 82-133) and after 5 years 92 ml/min per 1.73 m2 (range 22-115). Three patients did not reach the target dose of enalapril because of orthostatic hypotension. One of them was the only patient to develop chronic renal failure within 5 years. The present study indicates that enalapril reduces urinary protein excretion and preserves glomerular filtration in Alport patients as a group. However, there was individual variation, as in most studies of patients with proteinuric nephropathies given inhibitors of the angiotensin-converting enzyme.

Renoprotection by ACE inhibitors after severe hemolytic uremic syndrome.

Five patients with severe hemolytic uremic syndrome (HUS) were followed for 10-18 years. Because of proteinuria, arterial hypertension, and reduced glomerular filtration rates, they received either captopril (n=2) or enalapril (n=3), or both (n=1) for 8-15 years. Blood pressure was normalized and proteinuria reduced in all; glomerular filtration improved in three patients and fell moderately in two. Four of the five patients have reached adult age with body weight and height, blood pressure, and serum creatinine levels within the normal range. At the last evaluation, median proteinuria was 220 mg/24 h (range 0-310) and glomerular filtration rate 56 ml/min per 1.73 m(2)(range 40-127). This long-term study indicates a renoprotective effect of angiotensin-converting enzyme inhibitors in patients with sequelae after HUS.

Tuberous sclerosis with cystic renal disease and multifocal renal cell carcinoma in a baby girl.

An infant, in whom the prenatal diagnosis of tuberous sclerosis complex was made, presented with extreme bilateral nephromegaly owing to diffuse cystic changes. Histology of the resected non-functioning left kidney revealed, in addition to the characteristic cysts, two foci of renal cell carcinoma not visible on US or MRI. This infant is exceptional given the extensive cystic transformation of both kidneys and the presence of malignant lesions at this young age.

Pseudo-Bartter syndrome in a neonate on prostaglandin infusion.

UNLABELLED: We describe a case of iatrogenic pseudo-Bartter syndrome caused by administration of prostaglandin E1 (PGE1 alprostadil). Although the use of i.v. PGE1 is a well-established pharmacological therapy in neonates with a ductus-dependent congenital cardiopathy to ensure ductus-dependent flow, we could only find one other report on pseudo-Bartter syndrome related to PGE1 infusion. CONCLUSION: Primary Bartter syndrome is associated with endogenous increased levels of prostaglandins. Therefore, we postulate that the dose of prostaglandin E1 administered, immaturity and the genetic background are all relevant factors involved in the phenotypic presentation of iatrogenic pseudo-Bartter syndrome in this preterm infant.