This study aims to understand the response of the trophic state index (TSI) of a reservoir under different watershed land-use scenarios. A novel methodology was applied to the Verde River Basin in ...the south of Brazil, which is exploited by agricultural activity and has a reservoir for water supply. An ecohydrological model was used to calculate daily nutrient concentrations in the water system, which allowed the determination of the reservoir's TSI. The authors propose a new TSI known as TSI
mod
, considering phosphorus, nitrogen, and chlorophyll in its determination. The results indicate that TSI
mod
may be more appropriate for classifying highly impacted environments when compared to the index currently used in Brazil. The Verde River Reservoir was classified as mesotrophic under the current land-use scenario and eutrophic under the proposed scenarios. The framework developed in this study can be replicated in other watersheds to evaluate the impacts of land-use change on water quality.
Spinal muscular atrophy is an autosomal recessive neurodegenerative disorder characterized by progressive muscle wasting and loss of muscle function due to severe motor neuron dysfunction, secondary ...to mutations in the survival motor neuron 1 (SMN1) gene. A second neighboring centromeric gene, SMN2, is intact in all patients but contains a C-to-T variation in exon 7 that affects a splice enhancer and determines exclusion of exon 7 in the majority of its transcript, leading to an unstable protein that cannot substitute for mutant SMN1. Following successful studies on disease models and intensive studies on SMN functions in the past decade, SMN upregulation targeting SMN2, has been suggested as a possible therapeutic approach. Recently, we have witnessed an historical turning point with the first disease-modifying treatment receiving Food and Drug Administration approval and now being available to patients also outside the clinical trial. This innovative treatment is an antisense oligonucleotide, which, administered intrathecally, is able to increase exon 7 inclusion in the majority of the SMN2 mRNA and increase the production of fully functional SMN protein. Alternative advanced therapies, such as viral vector mediated gene therapy and orally available small molecules, are also showing promising results in early clinical trial phases.
Abstract The motor skills of patients with spinal muscular atrophy, type I (SMA-I) are very limited. It is difficult to quantify the motor abilities of these patients and as a result there is ...currently no validated measure of motor function that can be utilized as an outcome measure in clinical trials of SMA-I. We have developed the Children’s Hospital of Philadelphia Infant Test of Neuromuscular Disorders (“CHOP INTEND”) to evaluate the motor skills of patients with SMA-I. The test was developed following the evaluation of 26 infants with SMA-I mean age 11.5 months (1.4–37.9 months) with the Test of Infant Motor Performance and The Children’s Hospital of Philadelphia Test of Strength in SMA, a newly devised motor assessment for SMA. Items for the CHOP INTEND were selected by an expert panel based on item mean and standard deviation, item frequency distribution, and Chronbach’s alpha. Intra-rater reliability of the resulting test was established by test–retest of 9 infants with SMA-I over a 2 month period; Intraclass correlation coefficient (ICC) (3,1) = 0.96. Interrater reliability was by video analysis of a mixed group of infants with neuromuscular disease by 4 evaluators; ICC (3,4) = 0.98 and in a group of 8 typically developing infants by 5 evaluators ICC (3,5) = 0.93. The face validity of the CHOP INTEND is supported by the use of an expert panel in item selection; however, further validation is needed. The CHOP INTEND is a reliable measure of motor skills in patients with SMA-I and neuromuscular disorders presenting in infancy.
This study describes a mathematical model for bone remodeling that integrates the bone cells activities with the pharmacological dynamics for bone-seeking agents. The evolution of bone cells ...population involves the osteoblast-osteoclast signaling mediated by biochemical factors and receives both mechanical stimulus evaluated at the microscale and pharmacological regulation. A physiologically based pharmacokinetic model (PBPK) for bone-seeking agents was developed to provide the drug concentration on bone sites and feed the remodeling algorithm. The drug effect on bone was reproduced coupling three different strategies: modification of the RANKL expression, increase the osteoclast apoptosis and change in the rate of differentiation of preosteoblasts. Computational simulations were performed in the PBPK model considering different dosing regimens. A 3D finite element model of a proximal femur was generated and the simulation of the bone remodeling algorithm were implemented in Matlab. The results indicate that the proposed integrated model is able to capture adequately the expected adaptive behavior of bone subjected to mechanical and pharmacological stimulus. The model demonstrated to have potential for use as a platform to investigate therapies and may help in the study of new drugs for bone diseases.
•Cellular micromechanics and pharmacokinetics integrated in a bone remodeling model.•Drug concentration at bone sites alters the dynamics of bone cell populations.•Osteoporosis and its treatment simulated in a mechanobiologic model.•Physiologically based pharmacokinetics model for bone seeking agents.•Bone tissue modeled by a permeability rate limited tissue compartment model.
Highlights • Study of the biological response to different mechanical stimuli in a cellular dynamics model for bone remodelling. • Coupling of mechanical and biological models to describe the bone ...remodelling process. • Three proposals for mechanical stimuli were tested: strain energy density (SED), hydrostatic and deviatoric parts of SED. • The results show the temporal evolution of the apparent density distribution of bone.
Late-preterm infants (LPT) are at increased risk for long-term neurodevelopmental sequelae and iron deficiency. The aim of the study is to assess the positive effect of iron supplementation on ...psychomotor development in healthy LPT. We designed a randomized placebo-controlled double-blind trial dividing the newborns into two groups. Every patient was assessed using the Griffiths Mental Development Scales (GMDS)-II edition at 12-month post-conceptional age. The study was performed at the Neonatology Unit of our Hospital, in Italy. Sixty-six healthy LPT infants born between 34
0⁄7
and 36
6⁄7
weeks of gestational age were enrolled in the study. One group received martial prophylaxis from the third week of life to 6 months of post-conceptional age (2 mg/kg/day of iron pidolate), the other received placebo. Fifty-two of the enrolled infants were assessed using the GMDS at 12-month of post-conceptional age. Statistical analysis of the mean scores of the Griffiths subscales was performed. There was a difference in the mean developmental quotient (DQ) (p < 0.01) between the two groups: iron group mean DQ 121.45 ± 10.53 vs placebo group mean DQ 113.25 ± 9.70. Moreover, mean scores of the Griffiths subscales A, B, and D showed significant differences between the two groups (scale A p < 0.05, scale B p < 0.02, scale D p < 0.01, respectively).
Conclusions:
We recommend that all LPT neonates receive iron supplementation during the first 6 months of life in order to improve their 1-year neurodevelopmental quotient.
What is Known:
• Late-preterm infants (LPT) are at increased risk for long-term neurodevelopmental sequelae and also for iron deficiency.
• Iron deficiency is an independent risk factor for adverse neurological outcomes.
What is New:
• Healthy late-preterm who received iron supplementation during the first 6 months of life achieved better neurological outcomes at 12-month post-conceptional age than LPT who received placebo.
• Our study strongly supports the need for the implementation of martial prophylaxis in LPT neonates.
The aim of the study was to assess different outcome measures in a cohort of ambulant boys with Duchenne muscular dystrophy (DMD) over 12 months in order to establish the spectrum of possible changes ...in relation to age and steroid treatment.
The study is a longitudinal multicentric cohort study. A total of 106 ambulant patients with DMD were assessed using the 6-minute walk test (6MWT) and North Star Ambulatory Assessment (NSAA) at baseline and 12 months. Clinical data including age and steroid treatment were collected.
During the 12 months of the study, we observed a mean decline of 25.8 meters in the 6MWT with a SD of 74.3 meters. On NSAA, the mean decline was 2.2 points with a SD of 3.7. Not all the boys with DMD in our cohort showed a decline over the 12 months, with young boys showing some improvement in their 6MWT and NSAA scores up to the age of 7. NSAA and the 6MWT had the highest correlation (r = 0.52, p < 0.001).
This study provides longitudinal data of NSAA and 6MWT over a 12-month period. These data can be useful when designing a clinical trial.
Myosin heavy chain 7 (MYH7)-related myopathies are emerging as an important group of muscle diseases of childhood and adulthood, with variable clinical and histopathological expression depending on ...the type and location of the mutation. Mutations in the head and neck domains are a well-established cause of hypertrophic cardiomyopathy whereas mutation in the distal regions have been associated with a range of skeletal myopathies with or without cardiac involvement, including Laing distal myopathy and Myosin storage myopathy. Recently the spectrum of clinical phenotypes associated with mutations in MYH7 has increased, blurring this scheme and adding further phenotypes to the list. A broader disease spectrum could lead to misdiagnosis of different congenital myopathies, neurogenic atrophy and other neuromuscular conditions.
As a result of a multicenter Italian study we collected clinical, histopathological and imaging data from a population of 21 cases from 15 families, carrying reported or novel mutations in MYH7. Patients displayed a variable phenotype including atypical pictures, as dropped head and bent spine, which cannot be classified in previously described groups. Half of the patients showed congenital or early infantile weakness with predominant distal weakness. Conversely, patients with later onset present prevalent proximal weakness. Seven patients were also affected by cardiomyopathy mostly in the form of non-compacted left ventricle. Muscle biopsy was consistent with minicores myopathy in numerous cases. Muscle MRI was meaningful in delineating a shared pattern of selective involvement of tibialis anterior muscles, with relative sparing of quadriceps.
This work adds to the genotype-phenotype correlation of MYH7-relatedmyopathies confirming the complexity of the disorder.
There are currently no effective treatments to halt the muscle breakdown in Duchenne muscular dystrophy (DMD), although genetic-based clinical trials are being piloted. Most of these trials have as ...an endpoint the restoration of dystrophin in muscle fibers, hence requiring sufficiently well-preserved muscle of recruited patients. The choice of the muscles to be studied and the role of noninvasive methods to assess muscle preservation therefore require further evaluation.
We studied the degree of muscle involvement in the lower leg muscles of 34 patients with DMD >8 years, using muscle MRI. In a subgroup of 15 patients we correlated the muscle MRI findings with the histology of open extensor digitorum brevis (EDB) muscle biopsies. Muscle MRI involvement was assigned using a scale 0-4 (normal-severe).
In all patients we documented a gradient of involvement of the lower leg muscles: the posterior compartment (gastrocnemius > soleus) was most severely affected; the anterior compartment (tibialis anterior/posterior, popliteus, extensor digitorum longus) least affected. Muscle MRI showed EDB involvement that correlated with the patient's age (p = 0.055). We show a correlation between the MRI and EDB histopathologic changes, with MRI 3-4 grades associated with a more severe fibro-adipose tissue replacement. The EDB was sufficiently preserved for bulk and signal intensity in 18/22 wheelchair users aged 10-16.6 years.
This study provides a detailed correlation between muscle histology and MRI changes in DMD and demonstrates the value of this imaging technique as a reliable tool for the selection of muscles in patients recruited into clinical trials.
To describe the course, complications, and prognosis of Ullrich congenital muscular dystrophy (UCMD), with special reference to life-changing events, including loss of ambulation, respiratory ...insufficiency, and death.
Review of the case notes of 13 patients with UCMD, aged 15 years or older at last visit, followed up at a tertiary neuromuscular centre, London, UK, from 1977 to 2007. Data collected were age at onset of symptoms, presenting symptoms, mobility, contractures, scoliosis, skin abnormalities, respiratory function, and feeding difficulties.
The mean age at onset of symptoms was 12 months (SD 14 months). Eight patients (61.5%) acquired independent ambulation at a mean age of 1.7 years (SD 0.8 years). Nine patients (69.2%) became constant wheelchair users at a mean age of 11.1 years (SD 4.8 years). Three patients continued to ambulate indoors with assistance. Forced vital capacity (FVC) values were abnormal in all patients from age 6 years. The mean FVC (% predicted) declined at a mean rate of 2.6% (SD 4.1%) yearly. Nine patients (69.2%) started noninvasive ventilation at a mean age of 14.3 years (SD 5.0 years). Two patients died of respiratory insufficiency.
In Ullrich congenital muscular dystrophy (UCMD), the decline in motor and respiratory functions is more rapid in the first decade of life. The deterioration is invariable, but not always correlated with age or severity at presentation. This information should be of help to better anticipate the difficulties encountered by patients with UCMD and in planning future therapeutic trials in this condition.
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