Complete skipping of exon 66 due to novel mutations of the dystrophin gene was identified in two Japanese families of Duchenne muscular dystrophy with severe mental retardation

Severe mental retardation is a rare complication of Duchenne muscular dystrophy (DMD). Here we report that two DMD cases showing severe mental retardation exhibit the same exon skipping event induced by different intron mutations. In the two Japanese DMD patients studied, the complete sequence of exon 66 of the dystrophin gene was found to be absent from the dystrophin mRNA, creating a premature stop codon in exon 67. Novel point mutations at the consensus sequence of the splice donor site of intron 66 (T9857(+2) to C in one case and G9857(+5) to T in the other case) were found to be the cause of complete exon skipping. Remarkably, severe mental retardation cosegregated with an exon 66-skipping event in their families. Furthermore, pachygyria was disclosed by magnetic resonance imaging (MRI) examination of the brain of one case. Our results suggested that exon 66 skipping should be examined in DMD cases with a severe form of mental retardation.     

Effect of Different Functional Food Supplements on the Gut Microbiota of Prediabetic Indonesian Individuals during Weight Loss

The gut microbiota has been shown in recent years to be involved in the development and severity of type 2 diabetes (T2D). The aim of the present study was to test the effect of a 2-week functional food intervention on the gut microbiota composition in prediabetic individuals. A randomized double-blind, cross-over trial was conducted on prediabetic subjects. Fifteen volunteers were provided products made of: (i) 50% taro flour + 50% wheat flour; (ii) these products and the probiotic L. plantarum IS-10506; or (iii) these products with beetroot adsorbed for a period of 2 weeks with 2 weeks wash-out in between. Stool and blood samples were taken at each baseline and after each of the interventions. The gut microbiota composition was evaluated by sequencing the V3–V4 region of the 16S rRNA gene and anthropometric measures were recorded. The total weight loss over the entire period ranged from 0.5 to 11 kg. The next-generation sequencing showed a highly personalized microbiota composition. In the principal coordinate analyses, the samples of each individual clustered closer together than the samples of each treatment. For six individuals, the samples clustered closely together, indicating a stable microbiota. For nine individuals, the microbiota was less resilient and, depending on the intervention, the beta-diversity transiently differed greatly only to return to the composition close to the baseline during the wash-out. The statistical analyses showed that 202 of the total 304 taxa were significantly different between the participants. Only Butyricimonas could be correlated with taro ingestion. The results of the study show that the highly variable interindividual variation observed in the gut microbiota of the participants clouded any gut microbiota modulation that might be present due to the functional food interventions.     

Effect of glucose and incubation temperature on metabolically active Lactobacillus plantarum from dadih in removing microcystin-LR.

Lactobacillus plantarum strains IS-10506 and IS-20506 isolated from Indonesian traditional fermented milk, dadih, were screened for their ability to remove the cyanobacterial toxin microcystin-LR (MC-LR) from aqueous solution (100 microg/L) at 22 and 37 degrees C. The objective was to study the main environmental factors influencing the metabolic activity of L. plantarum in MC-LR removal. Residual MC-LR was quantified using HPLC. Non-viable cells inactivated by boiling or acid showed only low MC-LR removal (<23 %). Viable L. plantarum strain IS-10506 at pH 7, at 22 and 37 degrees C was able to remove MC-LR, 64% and 43%, respectively, after 30 h. Strain IS-20506 at pH 7, at 22 and 37 degrees C removed 92% and 45 %, respectively, after 30 h. At 37 degrees C, the removal of MC-LR was lower than at 22 degrees C. Supplementation with glucose (1%, 2%, and 3%, w/v) resulted in faster and higher removal of MC-LR at 37 degrees C, while at 22 degrees C it did not improve MC-LR removal. In the presence of 1 % glucose, IS-10506 and IS-20506 demonstrated significantly the most efficient removal of 80% and 65% of applied MC-LR, after 25 and 20 h, respectively, at pH 7, 37 degrees C. Viable cells as well as active metabolism play important roles in removing MC-LR. This finding offers new and economical tools for decontaminating microcystin containing water.     

Chimeric RNA/ethylene-bridged nucleic acids promote dystrophin expression in myocytes of duchenne muscular dystrophy by inducing skipping of the nonsense mutation-encoding exon

Editing of dystrophin mRNA by induction of exon skipping, using antisense oligonucleotides, has been proposed as one way to generate dystrophin expression in Duchenne muscular dystrophy (DMD) patients. Here, antisense chimeric oligonucleotides consisting of RNA and a new modified nucleic acid are tested for activity to induce skipping of an exon containing a nonsense mutation. In a Japanese DMD case, a nonsense mutation (R1967X) due to a single nucleotide change in exon 41 of the dystrophin gene (C5899T) was identified. Oligonucleotides consisting of 2'-O-methyl RNA and a new 2'-O,4'-C-ethylene-bridged nucleic acid (ENA) were designed to bind the mutation site of exon 41, and their ability to induce exon 41 skipping in dystrophin mRNA was evaluated. Finally, among the specific oligonucleotides tested, an 18-mer RNA/ENA chimera was found to have the strongest activity, inducing exon 41 skipping in nearly 90% of dystrophin mRNA. Accordingly, nearly 90% of cultured myocytes were shown to be dystrophin positive by immunohistochemical analysis. Western blot analysis disclosed the presence of nearly normal-sized dystrophin up to 1 week after the transfection. Our results suggest that an RNA/ENA chimera can be used to express dystrophin in DMD.     

Detection of Epstein-Barr and Human Papilloma Viruses in the Middle Ear Squamous Cell Carcinoma

The uncommon ear tumor of middle ear squamous cell carcinoma (MESCC) is thought to be associated with the history of long-term chronic otitis media in the most cases. The main etiologic factor of MESCC is still unclear and may be multifactorial. Infections of Epstein-Barr virus (EBV) and Human Papillomavirus (HPV) are considered as one of the etiologic factor of MESCC. Previous studies have shown that the EBV and HPV have been detected in MESCC. Although the EBV and HPV have been implicated in human malignancies, their roles in pathogenesis of MESCC have not been elucidated. There has never been report on the presence of EBV and HPV in Indonesian MESCC. This study aimed to determine the presence of EBV and HPV in MESCC. Seven paraffin-embedded tissues of speciment from biopsy were analyzed for the presence of EBV and HPV by immunohistochemistry, stained using polyclonal antibody anti EBNA1 and anti HPV. The samples consisted of 4 (57 %) males and 3 (43 %) females with age range of 26–87 years old. Immunohistochemistry result demonstrated that EBV was detected in three of seven (43 %) and HPV in two of seven (29 %) samples. Coexistence of the presence of EBV and HPV were found in one of seven (14 %) sample. The presence of EBV and HPV in MESCC suggests that viral infection may play an important etiologic role in the carcinogenesis of middle ear.     

Source of the great A.D. 1257 mystery eruption unveiled,Samalas volcano,Rinjani Volcanic Complex,Indonesia

Polar ice core records attest to a colossal volcanic eruption that took place ca. A.D. 1257 or 1258, most probably in the tropics. Estimates based on sulfate deposition in these records suggest that it yielded the largest volcanic sulfur release to the stratosphere of the past 7,000 y. Tree rings, medieval chronicles, and computational models corroborate the expected worldwide atmospheric and climatic effects of this eruption. However, until now there has been no convincing candidate for the mid-13th century “mystery eruption.” Drawing upon compelling evidence from stratigraphic and geomorphic data, physical volcanology, radiocarbon dating, tephra geochemistry, and chronicles, we argue the source of this long-sought eruption is the Samalas volcano, adjacent to Mount Rinjani on Lombok Island, Indonesia. At least 40 km³ (dense-rock equivalent) of tephra were deposited and the eruption column reached an altitude of up to 43 km. Three principal pumice fallout deposits mantle the region and thick pyroclastic flow deposits are found at the coast, 25 km from source. With an estimated magnitude of 7, this event ranks among the largest Holocene explosive eruptions. Radiocarbon dates on charcoal are consistent with a mid-13th century eruption. In addition, glass geochemistry of the associated pumice deposits matches that of shards found in both Arctic and Antarctic ice cores, providing compelling evidence to link the prominent A.D. 1258/1259 ice core sulfate spike to Samalas. We further constrain the timing of the mystery eruption based on tephra dispersal and historical records, suggesting it occurred between May and October A.D. 1257.Over the last three decades, ice core records have offered a unique opportunity to study past volcanism and its environmental impacts. Glaciochemical records have yielded estimates of volcanic sulfate aerosol loadings in the stratosphere associated with large volcanic eruptions, and have also been used to gauge the Earth system response of volcanism (1, 2). These high-resolution records have also revealed many significant eruptions that remain otherwise unknown (3, 4). One of the largest of these “mystery eruptions” has an ice core sulfate deposit dated to A.D. 1258/1259, pointing to an eruption in A.D. 1257 or 1258 (5). Estimates of its stratospheric sulfate load are around eight- and two-times greater than those of Krakatau in A.D. 1883 and Tambora in A.D. 1815, respectively (6), ranking it among the most significant volcanic events of the Holocene (7).Tree-ring, historical, and archeological records attest to substantial climatic impacts, which were most pronounced in the northern hemisphere in A.D. 1258 (8–11). Medieval chronicles highlight an unseasonable cold summer with incessant rains, associated with devastating floods and poor harvests (10). The interhemispheric transport of tephra and sulfate suggests a low-latitude eruption (12, 13). Until now, however, identification of the volcano responsible for the medieval “year without summer” has remained uncertain, despite more than 30 y of investigations. Various candidates have been implicated, including Okataina (New Zealand), El Chichón (Mexico), and Quilotoa (Ecuador), but none of these presents a strong case with respect to eruption magnitude, geochemistry, and timing (14–17).Here, we present a unique and compelling candidate for the source of the mid-13th century mystery eruption, based—among others things—on historical records from Indonesia. The records we use are known as Babad Lombok and written on palm leaves in Old Javanese. These documents describe a catastrophic caldera-forming eruption of Mount Samalas, a volcano adjacent to Mount Rinjani (Lombok Island) (Fig. 1), and the formation of the 6 × 8.5-km-wide and 800-m-deep Segara Anak caldera (Fig. 2A) and the horseshoe-shaped collapse structure that deeply incises the western flank of Rinjani volcano (Fig. 2B). The source also describes a sequence of volcanic phenomena (i.e., voluminous ashfall and pyroclastic flows) that would have devastated the lands and villages around the volcano, as well as the Kingdom’s capital, Pamatan, thereby killing thousands of people (18) (see the written sources provided in SI Materials and Methods). According to the Babad Lombok, this cataclysmic event took place before the Selaparang period (i.e., before the end of the 13th century). The age of the caldera was considered Holocene or older in the global databases and in the geological map of Lombok, whereas Nasution et al. (19) suggested that a caldera eruption had occurred between A.D. 1210 and A.D. 1260.Open in a separate windowFig. 1.Distribution of PDCs from the Samalas eruption and location of charcoal samples used for radiocarbon dating.Open in a separate windowFig. 2.Samalas caldera and Segara Anak. (A) Photograph of the present caldera viewed from the east (photo: Zulz, “Gunung Baru” June 26, 2006 via Flickr, Creative Commons License). (B) Present (shaded tones surface) and preexplosion reconstructed topography (black grid). We assume that a caldera was absent before the mid-13th century eruption, because no other large Plinian eruption has been identified.Drawing on physical volcanology, stratigraphic, and geomorphic data, high-precision radiocarbon dating, tephra geochemistry, and on an exegesis of historical texts, we present fresh evidence that corroborate the events described in the Babad Lombok. We suggest that the caldera-forming eruption of Samalas is one the largest events of the past 7,000 y (Table S1), and the likely source of the A.D. 1258/1259 sulfate spike identified in polar ice cores. We reconstruct the nature and dynamics of the caldera-forming eruption of Samalas based on a study of associated deposits, and discuss the dating and geochemical evidence that link the volcano to the mid-13th century mystery eruption.