A newly identified c.1824_1828dupATACG mutation in exon 13 of the GAA gene in infantile-onset glycogen storage disease type II (Pompe disease)

Pompe disease or glycogen storage disease type II is a glycogen storage disorder associated with malfunction of the acid α-glucosidase enzyme (GAA; EC.3.2.1.3) leading to intracellular aggregations of glycogenin muscles. The infantile-onset type is the most life-threatening form of this disease, in which most of patients suffer from cardiomyopathy and hypotonia in early infancy. In this study, a typical case of Pompe disease was reported in an Iranian patient using molecular analysis of the GAA gene. Our results revealed a new c.1824_1828dupATACG mutation in exon 13 of the GAA gene. In conclusion, with the finding of this novel mutation, the genotypic spectrum of Iranian patients with Pompe disease has been extended, facilitating the definition of disease-related mutations.     

Manipulation of micro- and nanoparticles in viscoelastic fluid flows within microfluid systems

Manipulation of micro- and nanoparticles in complex biofluids is highly demanded in most biological and biomedical applications. A significant number of microfluidic platforms have been developed for inexpensive, rapid, accurate, and efficient particle manipulation. Due to the enormous potential of viscoelastic fluids (VEFs) for particle manipulation, various emerging microfluidic-based VEFs techniques have been presented over the last decade. This review provides an intuitive understanding of VEF physics for particle separation in different microchannel geometries. Besides, active and passive VEF methods are critically reviewed, highlighting the potential and practical challenges of each technique for particle/cell focusing, sorting, and separation. The outcome of this study could enable recognizing deliverable VEF technology with the promising prospect in the manipulation of submicron biological samples (e.g., exosomes, DNA, and proteins).     

Huntington’s Disease and Mitochondrial DNA Deletions: Event or Regular Mechanism for Mutant Huntingtin Protein and CAG Repeats Expansion?!

The mitochondrial DNA (mtDNA) may play an essential role in the pathogenesis of the respiratory chain complex activities in neurodegenerative disorders such as Huntington's disease (HD). Research studies were conducted to determine the possible levels of mitochondrial defect (deletion) in HD patients and consideration of interaction between the expanded Huntingtin gene as a nuclear gene and mitochondria as a cytoplasmic organelle. To determine mtDNA damage, we investigated deletions based in four areas of mitochondrial DNA, in a group of 60 Iranian patients clinically diagnosed with HD and 70 healthy controls. A total of 41 patients out of 60 had CAG expansion (group A). About 19 patients did not show expansion but had the clinical symptoms of HD (group B). MtDNA deletions were classified into four groups according to size; 9 kb, 7.5 kb, 7 kb, and 5 kb. We found one of the four-mtDNA deletions in at least 90% of samples. Multiple deletions have also been observed in 63% of HD patients. None of the normal control (group C) showed mtDNA deletions. The sizes or locations of the deletions did not show a clear correlation with expanded CAG repeat and age in our samples. The study presented evidence that HD patients had higher frequencies of mtDNA deletions in lymphocytes in comparison to the controls. It is thus proposed that CAG repeats instability and mutant Htt are causative factor in mtDNA damage.     

Folic Acid Supplementation Promotes Mammary Tumor Progression in a Rat Model

Folic acid supplementation may prevent the development of cancer in normal tissues but may promote the progression of established (pre)neoplastic lesions. However, whether or not folic acid supplementation can promote the progression of established (pre)neoplastic mammary lesions is unknown. This is a critically important issue because breast cancer patients and survivors in North America are likely exposed to high levels of folic acid owing to folic acid fortification and widespread supplemental use after cancer diagnosis. We investigated whether folic acid supplementation can promote the progression of established mammary tumors. Female Sprague-Dawley rats were placed on a control diet and mammary tumors were initiated with 7,12-dimethylbenza[a]anthracene at puberty. When the sentinel tumor reached a predefined size, rats were randomized to receive a diet containing the control, 2.5x, 4x, or 5x supplemental levels of folic acid for up to 12 weeks. The sentinel mammary tumor growth was monitored weekly. At necropsy, the sentinel and all other mammary tumors were analyzed histologically. The effect of folic acid supplementation on the expression of proteins involved in proliferation, apoptosis, and mammary tumorigenesis was determined in representative sentinel adenocarcinomas. Although no clear dose-response relationship was observed, folic acid supplementation significantly promoted the progression of the sentinel mammary tumors and was associated with significantly higher sentinel mammary tumor weight and volume compared with the control diet. Furthermore, folic acid supplementation was associated with significantly higher weight and volume of all mammary tumors. The most significant and consistent mammary tumor-promoting effect was observed with the 2.5x supplemental level of folic acid. Folic acid supplementation was also associated with an increased expression of BAX, PARP, and HER2. Our data suggest that folic acid supplementation may promote the progression of established mammary tumors. The potential tumor-promoting effect of folic acid supplementation in breast cancer patients and survivors needs further clarification.     

Separation of bacteria smaller than 4 µm from other blood components using insulator-based dielectrophoresis: numerical simulation approach

Biomechanics and Modeling in Mechanobiology - Bloodstream infection (BSI) is a life-threatening infection that causes more than 80,000 deaths and more than 500,000 infections annually in North...