Mechanical force promotes dimethylarginine dimethylaminohydrolase 1-mediated hydrolysis of the metabolite asymmetric dimethylarginine to enhance bone formation

Mechanical force is critical for the development and remodeling of bone. Here we report that mechanical force regulates the production of the metabolite asymmetric dimethylarginine (ADMA) via regulating the hydrolytic enzyme dimethylarginine dimethylaminohydrolase 1 (Ddah1) expression in osteoblasts. The presence of -394 4 N del/ins polymorphism of Ddah1 and higher serum ADMA concentration are negatively associated with bone mineral density. Global or osteoblast-specific deletion of Ddah1 leads to increased ADMA level but reduced bone formation. Further molecular study unveils that mechanical stimulation enhances TAZ/SMAD4-induced Ddah1 transcription. Deletion of Ddah1 in osteoblast-lineage cells fails to respond to mechanical stimulus-associated bone formation. Taken together, the study reveals mechanical force is capable of down-regulating ADMA to enhance bone formation.

An investigation on the chloroplast and nuclear genomes of taxa belong to the subgenus Dracunculus (Bess.) Rydb. of Artemisia L. (Asteraceae) in Turkey

Artemisia is one of the biggest genera in the family Asteraceae, with around 500-600 taxa at specific and sub-specific levels and organised in 5 subgenera. Due to the high number of taxa, a lot taxonomists are trying to solve the problem of its classification and phylogeny but its natural classification still hasn’t been achieved. In this research, 60 individuals belonging to 4 taxa of the subgenus Dracunculus of Artemisia L. in Turkey were examined. For all the examined individuals from both the same and different populations belonging to the taxa of the subgenus Dracunculus, the sequences of the regions both psbA-trnH of chloroplast DNA and ITS of nuclear DNA were determined. Also, the gene regions obtained were recorded in the NCBI GenBank database and an accession number was taken. It was found that there was no gene flow and hybridization between the four studied taxa of the subgenus Dracunculus, and these 4 taxa also completed their speciation. According to the results of this molecular study, A. campestris var. campestris, A. campestris var. marschalliana and A. campestris var. araratica were proposed to be raised from the variety level to the species level. This research is important as it is the first molecular based study relating with the subgenus Dracunculus growing in Turkey.

Molecular inference of subgenus Hermodactyloides Spach for vascular flora of Iraq

Iris reticulata of sect. Reticulata from subg. Hermodactyloides in Iraq have been circumscribed based on morphological characters long time ago. Recent work, carried out in neighbouring countries (Turkey and Iran), added the new sect. Zagrica, which includes four new species. No molecular study has been performed yet to confirm the status of this subgenus. In this work, a phylogenetic study of the subg. Hermodactyloides was carried out by using internal transcribed spacer (ITS) region as well as morphological traits, with the aim to examine this subgenus in Iraq. Molecular data indicate that a new section is diverged from Hermodachtyloides and should be added to vascular flora of Iraq as a second section named Zagrica. This outcome is consistent with the morphological description. This work also implies that leaf transverse section should be considered as main morphological characters to be taken into account to separate the Reticulata section from Zagrica which has the same taxonomical value as the position of ovary (above ground or subterranean).

Molecular Study of Escherichia albertii in Pediatric Urinary Tract Infections

Background: There are insufficient data about the presence of E. albertii as a causative organism in urinary tract infection in pediatric patients. Objective: The present study aimed to detect E. albertii by polymerase chain reaction (PCR) for detection of uidA, mdh, and lysP genes among isolated E.coli from children with urinary tract infection. Methods: The present study was a cross-sectional retrograde study which was carried out on 100 isolates of phenotypically confirmed E.coli detected in urine samples of children suffering from urinary tract infection. The isolates were subjected to molecular identification by PCR for uidA, mdh, and lysP genes. Results: E. albertii was identified by PCR in 7% of the isolates and E.coli was identified in 93% of the isolates. Two mdh and lysP genes were detected for E. albertii and the uidA gene for E. coli. E. albertii isolates had marked resistance to gentamicin (71.4%), followed by resistance to ciprofloxacin (57.1%), meropenem and imipenem (42.9% each) and ESBL activity by double discs method was reported in 57.1% of the isolates. However, none of the isolates had shown resistance to nalidixic acid and only one isolate had resistance to norfloxacin. There was a statistically insignificant difference between resistance to the used antibiotics such as aztreonam (P=0.083), ampicillin/clavulanate (P=0.5), ciprofloxacin (P=0.69), gentamicin (P=0.3) and ceftazidime (P=1.00). Conclusion: The present study highlights the emergence of E. albertii as a pathogen associated with urinary tract infections in children. There is marked antibiotic resistance of this pathogen, especially toward extended spectrum beta-lactams antibiotics. The identification method depends mainly on genetic studies. Further longitudinal studies with large number of patients are required to verify the accurate prevalence of this bacterium.