Molecular analysis of the CYP21 gene and prenatal diagnosis in families with 21-hydroxylase deficiency in northeastern Iran

OBJECTIVES: A rapid and convenient approach for the detection of the most common CYP21 gene mutations in patients with congenital adrenal hyperplasia (CAH) with classical forms of 21-hydroxylase deficiency was used. In addition, a new semiquantitative strategy for the detection of del8-bp was designed. These procedures were used for prenatal diagnosis and genotype-phenotype correlation in northeastern Iran. Design: Molecular analysis of the CYP21 gene for the detection of the 9 most common mutations (CYP21gene deletion, P30L, i2g, del-8bp, I172N, E6 cluster, V281L, Q318X and R356W) was performed on 30 CAH patients and for prenatal diagnosis in 2 cases. METHODS: Restriction fragment length polymorphism, amplification-created restriction sites, allele-specific polymerase chain reaction (PCR) and semiquantitative PCR were performed. RESULTS: We characterized 90% of the CAH chromosomes. The most frequent mutations in the CYP21 gene were del-CYP21 (25%), I172N (22%) and i2g (15%). Unlike in other ethnic groups, there was no R356W mutation, however, a higher rate of del-8bp (10%) was found in our population. Wealso found 6 complex alleles in our patients. For 2 families prenatal CYP21 gene analysis resulted in the diagnosis of healthy fetuses and termination of dexamethasone treatment in the 15th week of gestation. Genotype-phenotype correlation was observed. The rate of homozygosity (50%) was greater than the predicted values due to the higher rate of parental consanguinity in our population. CONCLUSIONS: These molecular procedures proved to be sensitive and rapid for the detection of the most common mutations of the CYP21 gene and prenatal diagnosis. Increased 17-hydroxyprogesterone, found in neonatal CAH screening, can be confirmed by these mutation analyses.     

Essential‐Oil Composition of the Fruits of Six Heracleum L. Species from Iran: Chemotaxonomic Significance

The fruit essential oils of Heracleum persicum, H. rechingeri, H. gorganicum, H. rawianum, H. pastinacifolium, and H. anisactis from Iran were obtained by hydrodistillation and characterized by GC‐FID and GC/MS analyses. The oils of the six species were compared to determine the similarities and differences among their compositions. Overall, 36 compounds were identified in the fruit oils, accounting for 92.40–96.74% of the total oil compositions. Aliphatic esters constituted the main fraction of the oils (86.61–94.31%), with octyl acetate and hexyl butyrate as the major components. The oil compositions of species belonging to section Pubescentia (H. persicum, H. gorganicum, and H. rechingeri) were discriminated by equally high contents of both octyl acetate (13.84–20.48%) and hexyl butyrate (17.73–38.36%). On the other hand, the oils of H. rawianum, H. pastinacifolium and H. anisactis, belonging to section Wendia, showed lower hexyl butyrate contents (3.62–6.6%) and higher octyl acetate contents (48.71–75.36%) than the former. Moreover, isoelemicin was identified at low amounts (0.10–2.51%) only in the oils of the latter species. The differences in the oil composition among the six species were investigated by hierarchical cluster and principal component analyses, which indicated that the oil composition confirmed well the taxonomical classification based on the morphological and botanical data, and, thus, may provide a reliable marker to discriminate Heracleum species at the intersectional level.     

The abundance of short proteins in the mammalian proteome

Short proteins play key roles in cell signalling and other processes, but their abundance in the mammalian proteome is unknown. Current catalogues of mammalian proteins exhibit an artefactual discontinuity at a length of 100 aa, so that protein abundance peaks just above this length and falls off sharply below it. To clarify the abundance of short proteins, we identify proteins in the FANTOM collection of mouse cDNAs by analysing synonymous and non-synonymous substitutions with the computer program CRITICA. This analysis confirms that there is no real discontinuity at length 100. Roughly 10% of mouse proteins are shorter than 100 aa, although the majority of these are variants of proteins longer than 100 aa. We identify many novel short proteins, including a “dark matter” subset containing ones that lack detectable homology to other known proteins. Translation assays confirm that some of these novel proteins can be translated and localised to the secretory pathway.     

microRNA-141 is associated with hepatic steatosis by downregulating the sirtuin1/AMP-activated protein kinase pathway in hepatocytes

Sirtuin1 (SIRT1) is a crucial regulator of metabolism and it is implicated in the metabolic pathophysiology of several disorders inclusive of Type 2 diabetes and fatty liver disease (NAFLD). The aim of this study was to investigate the role of miR-141 in hepatic steatosis via regulation of SIRT1/AMP-activated protein kinase (AMPK) pathway in hepatocytes. Liver hepatocellular cells (HepG2) were treated with high concentration of glucose to be subsequently used for the assessment of miR-141 and SIRT1 levels in a model of hepatic steatosis. On the other hand, cells were transfected with miR-141 to investigate its effect on hepatocyte steatosis and viability as well as SIRT1 expression and activity along with AMPK phosphorylation. Targeting of SIRT1 by miR-141 was evaluated by bioinformatics tools and confirmed by luciferase reporter assay. Following the intracellular accumulation of lipids in HepG2 cells, the level of miR-141 was increased while SIRT1 mRNA and protein levels, as well as AMPK phosphorylation, was decreased. Transfection with miR-141 mimic significantly downregulated SIRT1 expression and activity while miR-141 inhibitor had the opposite effects. Additionally, modulation of miR-141 levels significantly influenced AMPK phosphorylation status. The results of luciferase reporter assay verified SIRT1 to be directly targeted by miR-141. miR-141 could effectively suppress SIRT1 and lead to decreased AMPK phosphorylation in HepG2 cells. Thus, miR-141/SIRT1/AMPK signaling pathway may be considered a potential target for the therapeutic management of NAFLD.     

An Ultra-Wideband Terahertz Metamaterial Absorber Utilizing Sinusoidal-Patterned Dielectric Loaded Graphene

In this paper, a non-structured graphene sheet loaded with a sinusoidal-patterned dielectric is introduced as an ultra-wideband metamaterial absorber in terahertz regime. Regardless of conventional structures with multilayered-graphene, a single layer sheet of non-structured graphene is used whereas the proposed structure benefits from dielectric width modulation and cavity method in order to excite continuous graphene plasmon resonances. The structure comprises four layers that two Fabry-Perot cavity mirrors are constructed by upper sinusoidal-patterned dielectric and a gold film. Full wave simulation results demonstrate that a broadband over 90% absorption with absolute bandwidth of 6.58 THz and central frequency of 3.97 THz is achieved under normal TE/TM incident plane wave. The designed structure yields 166% relative bandwidth. According to the symmetric configuration, the absorption spectra of mentioned polarizations are thoroughly close to each other resulting to a polarization insensitive structure. The stability of bandwidth and absorbance of the structure versus angle of incidence, θ, up to 35°/65° for TM/TE polarizations, respectively, and azimuth angle, φ, shows an interesting capability for utilization as detectors and sensors. The simple geometry of utilized graphene layer results in easy fabrication. The designed structure has wideband absorption in THz regime. Moreover, it is more compact than conventional broadband THz absorbers.

     

Assessing coral reefs on a pacific-wide scale using the microbialization score

The majority of the world's coral reefs are in various stages of decline. While a suite of disturbances (overfishing, eutrophication, and global climate change) have been identified, the mechanism(s) of reef system decline remain elusive. Increased microbial and viral loading with higher percentages of opportunistic and specific microbial pathogens have been identified as potentially unifying features of coral reefs in decline. Due to their relative size and high per cell activity, a small change in microbial biomass may signal a large reallocation of available energy in an ecosystem; that is the microbialization of the coral reef. Our hypothesis was that human activities alter the energy budget of the reef system, specifically by altering the allocation of metabolic energy between microbes and macrobes. To determine if this is occurring on a regional scale, we calculated the basal metabolic rates for the fish and microbial communities at 99 sites on twenty-nine coral islands throughout the Pacific Ocean using previously established scaling relationships. From these metabolic rate predictions, we derived a new metric for assessing and comparing reef health called the microbialization score. The microbialization score represents the percentage of the combined fish and microbial predicted metabolic rate that is microbial. Our results demonstrate a strong positive correlation between reef microbialization scores and human impact. In contrast, microbialization scores did not significantly correlate with ocean net primary production, local chla concentrations, or the combined metabolic rate of the fish and microbial communities. These findings support the hypothesis that human activities are shifting energy to the microbes, at the expense of the macrobes. Regardless of oceanographic context, the microbialization score is a powerful metric for assessing the level of human impact a reef system is experiencing.     

Relationship between muscle length and moment arm on EMG activity of human triceps surae muscle.

PURPOSE: The purpose of this experiment was to evaluate the effects of both muscle length and moment arm (MA) on the electromyographic (EMG) and force output of the triceps surae (TS) muscle. RELEVANCE: It is well recognized that changes in muscle length affect both the muscle's force generating capacity as well as its twitch speed. This relationship is well established in animal preparations. Contrary to animal experiments where length can be directly manipulated in isolated muscles, human experiments require that all muscle length changes be secondary to changes in a joint angle. Such experimental manipulations therefore produce changes in not only muscle length, but also in the muscle's MA. The relative effect of muscle length and MA changes on muscle EMG has not been determined in previous experiments. METHODS: This study was executed in two phases. First, using fresh human cadaver lower limbs, data were gathered describing the relationship between knee and ankle angle changes for maintenance of a constant TS muscle length, while its MA at the ankle joint has been changed. In the second phase of the study, results obtained from phase one were applied to 10 healthy adult human subjects to measure the EMG (surface and fine wire) activity of TS at three different conditions: when both length and MA were shortened, when muscle length was decreased given a constant MA and when MA was shortened given a constant muscle length. RESULTS: A significant increase in muscle activity was found as both the length and MA of TS muscle were shortened. A similar pattern of increased muscle activity was observed when the MA was shortened given a constant muscle length. No significant change in TS activity was found when muscle length was shortened, given a constant MA at the ankle joint. CONCLUSIONS: The findings of this study indicate that changes in the Achilles tendon MA predominate over the muscle length variations in determining the level of TS activity when generating plantar flexion torque.