37 research outputs found
Integrating Technical Standards into ET Curricula to Meet ABET Standards and Industry Needs
With technical standards affecting nearly every aspect of our daily lives, from computers to the components and materials used in car engines, it is critical that undergraduate students are educated on the importance of standards and provided with opportunities to locate and apply relevant technical standards to real world situations. In addition, with ABET accreditation requiring students to have a “basic understanding and familiarity with,” and experience “using” codes and standards, faculty need to consider how such material can be naturally integrated into the curriculum.
At Purdue University, education about codes and standards has been integrated into the mechanical engineering technology (MET) curriculum for decades with significant success. This paper discusses how standards are incorporated into mechanical design and quality control courses, as well as strategies for integrating standards into more courses in an MET curriculum. In addition, a discussion of standards resources that are freely available is included. Finally, a call to action for industry is presented, explaining the need and potential areas where industry can increase involvement in teaching students about technical standards
Goldberg-Shprintzen syndrome is determined by the absence, or reduced expression levels, of KIFBP.
Goldberg-Shprintzen syndrome (GOSHS) is caused by loss of function variants in the kinesin binding protein gene (KIFBP). However, the phenotypic range of this syndrome is wide, indicating that other factors may play a role. To date, 37 patients with GOSHS have been reported. Here, we document nine new patients with variants in KIFBP: seven with nonsense variants and two with missense variants. To our knowledge, this is the first time that missense variants have been reported in GOSHS. We functionally investigated the effect of the variants identified, in an attempt to find a genotype-phenotype correlation. We also determined whether common Hirschsprung disease (HSCR)-associated single nucleotide polymorphisms (SNPs), could explain the presence of HSCR in GOSHS. Our results showed that the missense variants led to reduced expression of KIFBP, while the truncating variants resulted in lack of protein. However, no correlation was found between the severity of GOSHS and the location of the variants. We were also unable to find a correlation between common HSCR-associated SNPs, and HSCR development in GOSHS. In conclusion, we show that reduced, as well as lack of KIFBP expression can lead to GOSHS, and our results suggest that a threshold expression of KIFBP may modulate phenotypic variability of the disease
Long-term follow-up and treatment in nine boys with X-linked creatine transporter defect
The creatine transporter (CRTR) defect is a recently discovered cause of X-linked intellectual disability for which treatment options have been explored. Creatine monotherapy has not proved effective, and the effect of treatment with L-arginine is still controversial. Nine boys between 8 months and 10 years old with molecularly confirmed CRTR defect were followed with repeated 1H-MRS and neuropsychological assessments during 4–6 years of combination treatment with creatine monohydrate, L-arginine, and glycine. Treatment did not lead to a significant increase in cerebral creatine content as observed with H1-MRS. After an initial improvement in locomotor and personal-social IQ subscales, no lasting clinical improvement was recorded. Additionally, we noticed an age-related decline in IQ subscales in boys affected with the CRTR defect
TMX2 Is a Crucial Regulator of Cellular Redox State, and Its Dysfunction Causes Severe Brain Developmental Abnormalities.
The redox state of the neural progenitors regulates physiological processes such as neuronal differentiation and dendritic and axonal growth. The relevance of endoplasmic reticulum (ER)-associated oxidoreductases in these processes is largely unexplored. We describe a severe neurological disorder caused by bi-allelic loss-of-function variants in thioredoxin (TRX)-related transmembrane-2 (TMX2); these variants were detected by exome sequencing in 14 affected individuals from ten unrelated families presenting with congenital microcephaly, cortical polymicrogyria, and other migration disorders. TMX2 encodes one of the five TMX proteins of the protein disulfide isomerase family, hitherto not linked to human developmental brain disease. Our mechanistic studies on protein function show that TMX2 localizes to the ER mitochondria-associated membranes (MAMs), is involved in posttranslational modification and protein folding, and undergoes physical interaction with the MAM-associated and ER folding chaperone calnexin and ER calcium pump SERCA2. These interactions are functionally relevant because TMX2-deficient fibroblasts show decreased mitochondrial respiratory reserve capacity and compensatory increased glycolytic activity. Intriguingly, under basal conditions TMX2 occurs in both reduced and oxidized monomeric form, while it forms a stable dimer under treatment with hydrogen peroxide, recently recognized as a signaling molecule in neural morphogenesis and axonal pathfinding. Exogenous expression of the pathogenic TMX2 variants or of variants with an in vitro mutagenized TRX domain induces a constitutive TMX2 polymerization, mimicking an increased oxidative state. Altogether these data uncover TMX2 as a sensor in the MAM-regulated redox signaling pathway and identify it as a key adaptive regulator of neuronal proliferation, migration, and organization in the developing brain
Pathogenic <i>SPTBN1</i> variants cause an autosomal dominant neurodevelopmental syndrome
SPTBN1 encodes βII-spectrin, the ubiquitously expressed β-spectrin that forms micrometer-scale networks associated with plasma membranes. Mice deficient in neuronal βII-spectrin have defects in cortical organization, developmental delay and behavioral deficiencies. These phenotypes, while less severe, are observed in haploinsufficient animals, suggesting that individuals carrying heterozygous SPTBN1 variants may also show measurable compromise of neural development and function. Here we identify heterozygous SPTBN1 variants in 29 individuals with developmental, language and motor delays; mild to severe intellectual disability; autistic features; seizures; behavioral and movement abnormalities; hypotonia; and variable dysmorphic facial features. We show that these SPTBN1 variants lead to effects that affect βII-spectrin stability, disrupt binding to key molecular partners, and disturb cytoskeleton organization and dynamics. Our studies define SPTBN1 variants as the genetic basis of a neurodevelopmental syndrome, expand the set of spectrinopathies affecting the brain and underscore the critical role of βII-spectrin in the central nervous system
COL4A1 Mutations Cause Ocular Dysgenesis, Neuronal Localization Defects, and Myopathy in Mice and Walker-Warburg Syndrome in Humans
Muscle-eye-brain disease (MEB) and Walker Warburg Syndrome (WWS) belong to a spectrum of autosomal recessive diseases characterized by ocular dysgenesis, neuronal migration defects, and congenital muscular dystrophy. Until now, the pathophysiology of MEB/WWS has been attributed to alteration in dystroglycan post-translational modification. Here, we provide evidence that mutations in a gene coding for a major basement membrane protein, collagen IV alpha 1 (COL4A1), are a novel cause of MEB/WWS. Using a combination of histological, molecular, and biochemical approaches, we show that heterozygous Col4a1 mutant mice have ocular dysgenesis, neuronal localization defects, and myopathy characteristic of MEB/WWS. Importantly, we identified putative heterozygous mutations in COL4A1 in two MEB/WWS patients. Both mutations occur within conserved amino acids of the triple-helix-forming domain of the protein, and at least one mutation interferes with secretion of the mutant proteins, resulting instead in intracellular accumulation. Expression and posttranslational modification of dystroglycan is unaltered in Col4a1 mutant mice indicating that COL4A1 mutations represent a distinct pathogenic mechanism underlying MEB/WWS. These findings implicate a novel gene and a novel mechanism in the etiology of MEB/WWS and expand the clinical spectrum of COL4A1-associated disorders
Confirmation of the chromosomal localization of human lamp genes and their exclusion as candidate genes for Salla disease
NPT4, a new microsomal phosphate transporter: Mutation analysis in glycogen storage disease type Ic
Deficiency of a microsomal phosphate transporter in the liver has been suggested in some patients affected by glycogen storage disease type Ic (GSD Ic). Several Na+/phosphate co-transporters have been characterized as members of the anion-cation symporter family. Recently, the cDNA sequence of two phosphate transporters, NPT3 and NPT4, expressed in liver, kidney and intestine, has been determined. We studied expression of human NPT4 in COS cells and observed an ER localization of the transporter by immunofluorescence microscopy. We speculated that this transporter could play a role in the regulation of the glucose-6-phosphatase (G6-Pase) complex. We revealed the genomic structure of NPT4 and analysed the gene as a candidate for GSD Ic. DNA was collected from five patients without mutations in G6-Pase or the G6-P transporter gene. DNA analysis of NPT4 revealed that one patient was heterozygous for a G>A transition at nucleotide 601 which would result in a G201R substitution. Our results do not confirm the hypothesis that this gene is mutated in GSD Ic patients. However, we cannot exclude that the mutation found reduces the phosphate transport efficiency, possibly modulating the G6-Pase complex
