Heterocyst-forming cyanobacteria are multicellular organisms that grow as chains of cells (filaments or trichomes) in which the cells exchange regulators and nutrients. In this article, we review the morphological, physiological and genetic data that have led to our current understanding of intercellular communication in these organisms. Intercellular molecular exchange appears to take place by simple diffusion through proteinaceous structures, known as septal junctions, which connect the adjacent cells in the filament and traverse the septal peptidoglycan through perforations known as nanopores. Proteins that are necessary to produce, and that may be components of, the septal junctions-SepJ, FraC and FraD-have been identified in the heterocyst-forming cyanobacterium sp. strain PCC 7120 model. Additionally, several proteins that are necessary to produce a normal number of nanopores and functional septal junctions have been identified, including AmiC-type amidases, peptidoglycan-binding proteins and some membrane transporters. Available reports and reevaluation of intercellular molecular transfer data for some mutants of suggest that the septal junctions can be regulated, likely by a mechanism of gating.
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http://dx.doi.org/10.3390/life9010001 | DOI Listing |
Clin Pract Cases Emerg Med
November 2024
Sher-i-Kashmir Institute of Medical Sciences Soura, Department of Anesthesia, Srinagar, Jammu and Kashmir, India.
Introduction: Although myocardial injury is common after blunt chest trauma, tricuspid valve injury associated with traumatic atrial septal defect resulting in acute hypoxia is an infrequent event. We report an unusual case of blunt chest trauma referred to us for unexplained hypoxemia, emphasizing the unusual nature of injury and the importance of comprehensive cardiac evaluation in such cases.
Case Report: A 35-year-old male presented to the emergency department after falling from a tree from an approximate height of 15 feet.
Ann Pediatr Cardiol
October 2024
Department of Cardiothoracic and Vascular Surgery, The Madras Medical Mission Hospital, Chennai, Tamil Nadu, India.
Objective: Skull base defects can be challenging to reconstruct. The nasoseptal flap (NSF) remains the first-line option for reconstruction. However, it can be inadequate to cover wide defects or compromised by tumor invasion or prior surgery requiring additional reconstructive options.
View Article and Find Full Text PDFCardiol Young
October 2024
Pediatric Cardiac Surgery, Saitama Medical University International Medical Center, Hidaka, Saitama, Japan.
A six-month-old boy with Down syndrome, complete atrioventricular septal defect with intact atrial septum, and moderate left-sided atrioventricular valve regurgitation underwent surgery. The presence of a common atrioventricular junction could not be diagnosed preoperatively. Postoperative left-sided atrioventricular valve regurgitation remained mild by complete cleft closure, direct closure of incised atrial septum, and patch augmentation of the underside of septum primum.
View Article and Find Full Text PDFCardiol Young
October 2024
Department of Thoracic and Cardiovascular Surgery, Hirosaki University School of Medicine, Hirosaki, Aomori, Japan.
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