bluuebunny/crossref_metadata_2025_split huggingface dataset:
Infantile mitochondrial DNA depletion syndrome associated with methylmalonic aciduria and 3‐methylcrotonyl‐CoA and propionyl‐CoA carboxylase deficiencies in two unrelated patients: A new phenotype of mtDNA depletion syndrome
Authors: Yano S. , Li L. , Le T. P. , Moseley K. , Guedalia A. , Lee J. , Gonzalez I. , Boles R. G. 
Published: September 2003

AbstractMitochondrial DNA (mtDNA) depletion refers to a quantitative defect in mtDNA and is heterogeneous with regard to causal genotypes and the associated clinical phenotypes. We report two unrelated infants with mtDNA depletion. A diagnosis of methylmalonic aciduria was initially raised in both on the basis of high urine methylmalonic acid and related organic acids and elevated propionylcarnitine and methylmalonylcarnitine. Carboxylase assay with skin fibroblasts revealed low propionyl‐CoA and 3‐methylcrotonyl‐CoA carboxylase and normal pyruvate carboxylase activities. Quantitative Southern blot analysis of mitochondrial and nuclear DNA with muscle tissues revealed the patients' mtDNA to be depleted to 24% and 39% of normal controls. Our two patients showed multiple mitochondrial dysfunction including respiratory chain defects and deficiencies in the two nuclear DNA encoded carboxylases resulting in abnormal urine organic acids. To our knowledge, there is no obvious connection between the defective pathways other than their mitochondrial locations. These two cases may represent a new entity of mitochondrial disease that might be due to a defective common mechanism, such as assembly, maintenance and transport, affecting various mitochondrial enzymes and functions. Mitochondrial depletion should be considered in infants with atypical organic aciduria that may resemble methylmalonic aciduria, propionic acidaemia, or 3‐methylcrotonyl‐CoA carboxylase deficiency.
Use of gabapentin to reduce chronic neuropathic pain in Fabry disease
Authors: Ries M. , Mengel E. , Kutschke G. , Kim K. S. , Birklein F. , Krummenauer F. , Beck M. 
Published: September 2003

AbstractThe effect of the anticonvulsant gabapentin on neuropathic pain was studied in six male patients with Fabry disease, aged 15–45 years. After 4 weeks of treatment, pain, as measured using the Brief Pain Inventory, was decreased compared with baseline. Treatment was generally well tolerated. This study indicates that gabapentin should be considered as a treatment option for the neuropathic pain of Fabry disease.
Administration of protein substitute and quality of control in phenylketonuria: A randomized study
Authors: MacDonald A. , Rylance G. , Davies P. , Asplin D. , Hall S. K. , Booth I. W. 
Published: September 2003

AbstractUneven administration of an L‐amino acid protein substitute is an important contributing factor in variability in plasma phenylalanine concentrations over the 24‐hour period in patients with phenylketonuria under treatment. The aim of this study was to determine whether manipulating the timing of protein substitution would reduce variability in plasma phenylalanine over 24 h. Sixteen children (aged 1‐11 years) with well‐controlled phenylketonuria were entered into a randomized crossover study in which four protocols of the same daily dose of protein substitute administration were compared. In protocol A, three equal, divided doses were given with meals over 10 h; in protocol B, three equal doses over 14 h; in protocol C, four equal doses over 14 h; and in protocol D, six equal doses over 24 h (3 subjects only). Four‐hourly skin puncture blood specimens were collected for 48 h in each study protocol. In protocols A, B and C, but not in protocol D, there was wide variability in 24 h plasma phenylalanine. The median daily differences (μmol/L) between highest and lowest phenylalanine concentrations were: for protocol A, 140; for protocol B, 100; for protocol C, 120; and for protocol D, 40. In protocol D, 97% of all phenylalanine concentrations were below 120 μmol/L and no concentration fell below 40νmol/L. Administration of protein substitute overnight as well as during daytime produces stable and lower plasma phenylalanine concentrations and may lead to improved dietary phenylalanine tolerance.
Physical‐statistical modeling in geophysics
Authors: Berliner L. Mark 
Published: September 2003

Two powerful formulas have been available to scientists for more than two centuries: Newton's second law, providing a foundation for classical physics, and Bayes's theorem, prescribing probabilistic learning about unknown quantities based on observations. For the most part the use of these formulas has been separated, with Newton being the more dominant in geophysics. This separation is arguably surprising since numerous sources of uncertainty arise in the application of classical physics in complex situations. One explanation for the separation is the difficulty in implementing Bayesian analysis in complex settings. However, recent advances in both modeling strategies and computational tools have contributed to a significant change in the scope and feasibility of Bayesian analysis. This paradigm provides opportunities for the combination of physical reasoning and observational data in a coherent analysis framework but in a fashion which manages the uncertainties in both information sources. A key to the modeling is the hierarchical viewpoint, in which separate statistical models are developed for the process variables studied and for the observations conditional on those variables. Modeling process variables in this way enables the incorporation of physics across a spectrum of levels of intensity, ranging from a qualitative use of physical reasoning to a strong reliance on numerical models. Selected examples from this spectrum are reviewed.
So far as the laws of mathematics refer to reality, they are not certain. And so far as they are certain, they do not refer to reality.Albert Einstein (1921)
Surgical site infections following pediatric liver transplantation: risks and costs
Authors: Hollenbeak C.S. , Alfrey E.J. , Sheridan K. , Burger T.L. , Dillon P.W. 
Published: September 2003

Abstract:Purpose. Infectious complications following orthotopic liver transplantation (OLT) represent a significant cause of morbidity and mortality in both adults and children. In adults, surgical site infections complicating OLT have been shown to significantly increase resource utilization, but their impact in children has not been studied. In this study we identify risk factors for surgical site infections in children undergoing primary OLT for end‐stage liver disease and estimate their impact on patient survival, graft survival, length of stay, and charges.Methods. All pediatric liver transplants (n = 77) less than 16 years of age from the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) Liver Transplantation Database were included in the analysis. Surgical site infections (n = 25) were defined as wound infections, abdominal abscesses, and bacterial or fungal infections of the liver, intestine, or peritoneum during the initial transplant admission. Risk of infection was estimated using logistic regression, survival rates were estimated using the Kaplan‐Meier method, and length of stay and charges were compared using Student's t‐test. Multivariate analysis of charges was performed using linear regression.Results. Of the 77 patients, 25 (32.5%) developed a surgical site infection. Several factors were associated with increased risk of infections, including a leak at the biliary anastomosis (odds ratio [OR] 115, P = 0.003), preoperative white blood cell count (OR = 1.28, P = 0.009), surgery > 7 h (OR = 15.0, P = 0.011), HLA mismatches (OR = 6.0, P = 0.03), and female gender (OR = 8.0, P = 0.038). Surgical site infections did not significantly decrease either patient survival or graft survival, and increased hospital stay by an average of 21 days (P = 0.14). After controlling for other factors, patients who developed surgical site infections incurred on average $132,507 (P = 0.03) more in charges than patients who did not develop infections.Conclusions. Surgical site infections in pediatric patients following liver transplantation are significantly influenced by surgical technique and endogenous patient characteristics. Though survival outcomes are not different, the development of such infections has significant implications for resource utilization in the care of these patients.
Temporal variation of energy reserves in mayfly nymphs (Hexagenia spp.) from Lake St Clair and western Lake Erie
Authors: Cavaletto J.F. , Nalepa T.F. , Fanslow D.L. , Schloesser D.W. 
Published: September 2003

Summary1. We analysed changes in energy reserves (lipid and glycogen) and length–weight relationships of burrowing mayflies (Hexagenia spp.) in 1997–99 to compare an established population in Lake St Clair with a recovering population in western Lake Erie of the Laurentian Great Lakes. In addition, we measured changes in water temperature and potential food in both water columns and sediments.2. Although overall mean values of lipid and glycogen levels of Hexagenia nymphs from Lake St Clair and western Lake Erie were not significantly different, there were differences in seasonal patterns between the two lakes. In Lake St Clair, levels were highest in early spring, declined throughout the year, and reached their lowest levels in fall during all 3 years of study. In contrast, levels in western Lake Erie were lower in spring, increased to a maximum in summer, then declined in fall. Seasonal patterns in length–weight relationships were similar to those for lipid and glycogen.3. Total lipid as a percentage of dry weight did not increase with developmental stage of nymphs until just prior to metamorphosis and emergence from water. However, the major reserve lipid, triacylglycerols, increased systematically with development stage. In the final stage of development, triacylglycerols declined, probably as a result of energy consumption and its conversion to other biochemical components for metamorphosis and reproduction.4. Indicators of potential food (algal fluorescence in the water column and chlorophyll a and chlorophyll a/phaeophytin ratio in sediments) suggest that Hexagenia in Lake St Clair have a food source that is benthic based, especially in early spring, whereas in western Lake Erie nymphs have a food source that is water column based and settles to the lake bottom during late spring and summer.
Measuring and controlling data quality in biological assemblage surveys with special reference to stream benthic macroinvertebrates
Authors: Cao Yong , Hawkins Charles P. , Vinson Mark R. 
Published: September 2003

Summary1. Biological assemblage surveys primarily aim to characterise species composition and relative abundance at one or more spatial or temporal scales. Data interpretation and conclusions are dependent on how well samples characterise the assemblage of interest.2. Conventional measures of data quality, e.g. standard deviations or coefficients of variation, were designed for single variable estimation, and they are either insufficient or invalid for assessing the quality of data describing entire assemblages. Similarity indices take species composition and relative abundance into account and may be used to effectively measure and control the quality of data used to characterise assemblage structure.3. The average Jaccard coefficient (JC) calculated across multiple pairs of replicate samples, i.e. autosimilarity JC (AJC), is conceptually and numerically related to the average coefficient of variation in the densities of all species recorded, a measure of sampling precision, and to the proportion of total species richness sampled, a measure of sampling accuracy.4. We explored how AJC can be used to assess the effect of different potential sources of error on the quality of assemblage survey data, including the sampling effort used both within regions and at individual sites, the individuals collecting samples, sub‐sampling procedures, and consistency of taxon identification.5. We found that the autosimilarity‐based approach overcomes most weaknesses associated with conventional measures of data quality and can be used to effectively measure and control the quality of assemblage survey data.
Habitat change in braided flood plains (Tagliamento, NE‐Italy)
Authors: Van Der Nat Dimitry , Tockner Klement , Edwards Peter J. , Ward J.V. , Gurnell Angela M. 
Published: September 2003

Summary1. Relative changes and age distribution of habitats were investigated in the active channel of a bar‐braided and an island‐braided reach of the Tagliamento River (NE‐Italy). Between September 1999 and January 2002, six habitat types were delineated with a differential Global Positioning System on five dates following floods of different magnitude. Overlay maps were employed to calculate age and relative change of habitats. We established exponential decay rates (k‐values) for islands and major aquatic habitats.2. Relative changes of all aquatic habitats combined were up to 82% between survey dates in the bar‐braided flood plain, with a cumulative rate of 85% over the 2.5‐year period. Relative habitat changes in the island‐braided flood plain were lower with a cumulative change of almost 60% during the study period. In the bar‐braided flood plain significant exponential decay relationships were established for channels, alluvial channels, backwaters, and ponds.3. Half‐lives were particularly short for backwaters and ponds. In the island‐braided reach, significant relationships existed for channels and alluvial channels. The half‐lives of channels and alluvial channels increased with the presence of vegetated islands. Relative habitat composition within the active corridor remained almost constant, supporting the applicability of the shifting mosaic steady state model to braided floodplain ecosystems.4. Our results indicate that under natural conditions aquatic floodplain habitats can be highly dynamic over short time‐scales. Even small water level fluctuations (‘flow pulses’) can lead to major habitat changes with important consequences for the fauna and flora.
Variation in the temperature preference and growth rate of individual fish reconciles differences between two growth models
Authors: Elliott J.M. , Hurley M.A. 
Published: September 2003

Summary1. A growth model, originally developed for brown trout (Salmo trutta), has now been fitted to data for Atlantic salmon (S. salar) and stone‐loach (Barbatula barbatula) from English populations, and Arctic charr (Salvelinus alpinus) from Sweden. The model relates growth rate to temperature for a fish of standard size and the functional relationship has a triangular shape with a sharp peak at the optimal temperature for growth and zero growth at the base of the triangle. It was unsuitable for growth data for Norwegian salmon, and a curvilinear Ratkowsky model provided a better fit, though the experimental protocol was different in the Norwegian and English experiments.2. The Norwegian salmon were kept in groups in each tank, had to compete for food, and had to be divided into slow, moderate and fast growers before the Ratkowsky model could be fitted. Each English salmon was kept in its own tank and fed individually. For replicate experiments, fish of similar size were selected. Variation among fish kept under similar conditions was therefore small, and the triangular model was essentially for individual fish, not groups of fish.3. The present simulation study tests the hypothesis that individual differences in the growth response could account for the curvilinear growth‐temperature relationship for the Norwegian salmon. The triangular model was used to generate the growth response to temperature for a group of salmon, each fish having a slightly different temperature preference and growth rate. The result was a curvilinear response, well approximated by the Ratkowsky model (adjusted R2 = 0.96). When the variability in individual temperature preference was increased, the Ratkowsky model was an even better fit (adjusted R2 = 0.98). Therefore, the apparent discrepancy between the two models was reconciled by allowing for individual differences in temperature preference and growth rate within groups of fish.
Are biological classifications of headwater streams concordant across multiple taxonomic groups?
Authors: Paavola Riku , Muotka Timo , Virtanen Risto , Heino Jani , Kreivi Petri 
Published: September 2003

Summary1. Studies assessing human impacts on freshwater ecosystems are typically based on a single taxonomic group, often macroinvertebrates or fish. Unfortunately, the degree to which such macroinvertebrate or fish‐based surveys can be generalised across other taxonomic groups remains largely unknown. A prerequisite for useful generalisations is that different taxonomic groups exhibit concordant patterns of community structure across sites.2. We examined the concordance among fish, benthic macroinvertebrates and bryophytes in 32 streams in a boreal catchment in Finland. Our goal was to test how consistently different taxonomic groups classify stream sites; for example, can site groupings based on macroinvertebrates be used as a surrogate for bryophyte or fish assemblage classification?3. Our results show that community classifications in headwater streams are not concordant across taxonomic groups, at least not at the within‐river system scale. The lack of concordance reflected the fact that all three groups responded to different environmental factors. Macroinvertebrate community structure was mainly correlated with stream size and pH, whereas bryophytes were related to water colour, nutrient content and in‐stream habitat variability. Fish community structure was best described by stream depth, substrate size and water oxygen concentration.4. Our results suggest that great care should be taken when typologies based on benthic macroinvertebrates, or any other taxonomic group, are extrapolated to other groups in creating typologies of lotic environments.
Photoheterotrophy and light‐dependent uptake of organic and organic nitrogenous compounds by Planktothrix rubescens under low irradiance
Authors: Zotina Tatiana , Köster Oliver , Jüttner Friedrich 
Published: September 2003

Summary1. Planktothrix rubescens is the dominant photoautotrophic organism in Lake Zürich, a prealpine, deep, mesotrophic freshwater lake with an oxic hypolimnion. Over long periods of the year, P. rubescens accumulates at the metalimnion and growth occurs in situ at irradiance near the photosynthesis compensation point. Experiments were conducted to evaluate the contribution of photoheterotrophy, heterotrophy and light‐dependent uptake of nitrogenous organic compounds to the carbon and nitrogen budget of this cyanobacterium under conditions of restricted availability of light quanta.2. We used both purified natural populations of P. rubescens from the depth of 9 m and an axenic culture grown under low irradiance at 11 μmol m−2 s−1 on a light : dark cycle (10 : 14 h) to determine the uptake rates of various amino acids, urea, glucose, fructose, acetate and inorganic carbon. The components were added to artificial lake water in low amounts that simulated the naturally occurring potential concentrations.3. The uptake rates of acetate and amino acids (glycine, serine, glutamate and aspartate) were strongly enhanced at low irradiance as compared with the dark. However, no difference was observed in the uptake of arginine, which was taken up at high rates under both treatments. The uptake rates of glucose, fructose and urea were very low under all conditions. Similar results were obtained for both axenic P. rubescens and for purified natural populations of P. rubescens that were separated from bacterioplankton and other phytoplankton.4. Metalimnetic P. rubescens that was stratified at low irradiance for weeks exhibited much higher uptake rates than filaments that were entrained in the deepening surface mixed layer and experienced higher irradiance. The added organic compounds contributed up to 62% to the total carbon uptake of metalimnetic P. rubescens. On the basis of a molar C : N ratio of 4.9, the nitrogen uptake as organic compounds satisfied up to 84% of the nitrogen demand.5. The experiments indicate that photoheterotrophy and light‐dependent uptake of nitrogenous organic compounds may contribute significantly to the carbon and nitrogen budget of filaments at low irradiance typical for growth of P. rubescens in the metalimnion and at the bottom of the surface mixed layer.
Hospitalization of childhood rotavirus infection from Kuala Lumpur, Malaysia
Authors: Lee WS , Veerasingam PD , Goh AYT , Chua KB 
Published: September 2003

Aim:  To determine the epidemiology of rotavirus gastroenteritis in children admitted to an urban hospital in a developing country from South‐East Asia.Methods:  Retrospective review of cases of acute gastroenteritis admitted to the children's ward of the University of Malaya Medical Centre, Kuala Lumpur, Malaysia, between 1996 and 1999.Results:  During the study period, 333 cases (24%) of 1362 stool samples, obtained from children admitted with acute diarrhoea, were positive for rotavirus. Acute gastroenteritis constituted 8.2%, and rotavirus infection 1.6% of all the paediatric admissions each year. Of the 271 cases analysed, 72% of the affected population were less than 2 years of age. Peak incidence of admissions was between January to March, and September to October. Dehydration was common (92%) but electrolyte disturbances, lactose intolerance (5.2%), prolonged diarrhoea (2.6%) and cow's milk protein intolerance was uncommon. No deaths were recorded.Conclusions:  Rotavirus infection was a common cause of childhood diarrhoea that required hospital admission in an urban setting in Malaysia.
Long and short‐term effect of prednisolone in hospitalized infants with acute bronchiolitis
Authors: Zhang L , Ferruzzi E , Bonfanti T , Auler MI , D’avila NE , Faria CS , Costa MM 
Published: September 2003

Objective:  To assess long and short‐term effect of prednisolone in hospitalized infants with bronchiolitisMethodology:  A randomized and controlled trial was carried out at the Federal University of Rio Grande, Rio Grande‐RS, Brazil. Twenty‐eight patients were randomly allocated prednisolone (1 mg/kg/day for 5 days) plus standard care, and 24 patients allocated standard care alone. The primary endpoint was the prevalence of post‐bronchiolitis wheezing at 1, 3, 6 and 12 months after hospital discharge. The secondary endpoints were: length of hospital stay, duration of oxygen therapy and time to clinical improvement during the hospitalization.Results:  There were no significant differences between the prednisolone and control group in the prevalence of post‐bronchioltis wheezing at 1 month (73.1 vs 83.3%, P = 0.5), 3 months (73.1 vs 79.2%, P = 0.7), 6 months (65.4 vs 66.7%, P = 0.9) and 12 months (50.0 vs 58.3%, P = 0.5) after hospital discharge. No reduction was observed in the prednisolone group, compared with the control group, in terms of length of hospital stay (6.0 vs 5.0 days, P = 0.7), duration of oxygen therapy (24.0 vs 24.0 h, P = 0.4) and time to clinical resolution (4.0 vs 4.0 days, P = 0.8).Conclusions:  Prednisolone has no significant effect on reducing the prevalence of post‐bronchiolitis wheezing and on improving the acute course of illness in hospitalized infants with bronchiolitis.