Koszul binomial edge ideals

It is shown that if the binomial edge ideal of a graph $G$ defines a Koszul algebra, then $G$ must be chordal and claw free. A converse of this statement is proved for a class of chordal and claw free graphs

Host carbon sources modulate cell wall architecture, drug resistance and virulence in a fungal pathogen

The survival of all microbes depends upon their ability to respond to environmental challenges. To establish infection, pathogens such as Candida albicans must mount effective stress responses to counter host defences while adapting to dynamic changes in nutrient status within host niches. Studies of C. albicans stress adaptation have generally been performed on glucose-grown cells, leaving the effects of alternative carbon sources upon stress resistance largely unexplored. We have shown that growth on alternative carbon sources, such as lactate, strongly influence the resistance of C. albicans to antifungal drugs, osmotic and cell wall stresses. Similar trends were observed in clinical isolates and other pathogenic Candida species. The increased stress resistance of C. albicans was not dependent on key stress (Hog1) and cell integrity (Mkc1) signalling pathways. Instead, increased stress resistance was promoted by major changes in the architecture and biophysical properties of the cell wall. Glucose- and lactate-grown cells displayed significant differences in cell wall mass, ultrastructure, elasticity and adhesion. Changes in carbon source also altered the virulence of C. albicans in models of systemic candidiasis and vaginitis, confirming the importance of alternative carbon sources within host niches during C. albicans infection

Global analysis of mutations driving microevolution of a heterozygous diploid fungal pathogen

Data deposition: The sequence reported in this paper has been deposited in the NCBI Sequence Read Archive, https://www.ncbi.nlm.nih.gov/bioproject (BioProject ID PRJNA345600). This article contains supporting information online at www.pnas.org/lookup/suppl/doi:10.1073/pnas.1806002115/-/DCSupplemental.Peer reviewedPublisher PD

On the symbolic powers of binomial edge ideals

We show that under some conditions, if the initial ideal in$_<(I)$ of an ideal $I$ in a polynomial ring has the property that its symbolic and ordinary powers coincide, then the ideal $I$ shares the same property. We apply this result to prove the equality between symbolic and ordinary powers for binomial edge ideals with quadratic Gr\"obner basis

Endoscopic Endonasal Transsphenoidal Approach in the Management of Sellar and Parasellar Lesions: and Standard Surgical Technique (Part I)

Transsphenoidal approaches have been used for a century for the resection of pituitary and other sellar tumors. In the past decade, however, the endoscopic endonasal transsphenoidal approach has been proposed as a minimally invasive procedure for the treatment of pathologies of the sellar region. This procedure introduces various advantages compared with the transsphenoidal microsurgical approach, such as an improved vision of the surgical field, less traumatism of the nasal structures and reduced complications. Patients’ quick recovery, short hospital stays and minimal postoperative discomfort have been observed. More recently, the standard endoscopic endonasal technique has been extended to provide access to parasellar lesions. This expansion carries significant potential for the resection of skull base lesions. In this article, the authors review the indications of the endoscopic endonasal transsphenoidal approach and define the main phases of the standard surgical technique. Preoperative evaluation, equipment, preoperative and postoperative care are presented. Endoscopic endonasal technique is a safe and effective method for removal of most sellar and some parasellar masses, providing more complete lesion excision and reducing complications

Identification of an active RNAi pathway in Candida albicans

RNA interference (RNAi) is a fundamental regulatory pathway with a wide range of functions, including regulation of gene expression and maintenance of genome stability. Although RNAi is widespread in the fungal kingdom, well-known species, such as the model yeast , have lost the RNAi pathway. Until now evidence has been lacking for a fully functional RNAi pathway in , a human fungal pathogen considered critically important by the World Health Organization. Here, we demonstrated that the widely used reference strain (SC5314) contains an inactivating missense mutation in the gene encoding for the central RNAi component Argonaute. In contrast, most other isolates contain a canonical Argonaute protein predicted to be functional and RNAi-active. Indeed, using high-throughput small and long RNA sequencing combined with seamless CRISPR/Cas9-based gene editing, we demonstrate that an active RNAi machinery represses expression of subtelomeric gene families. Thus, an intact and functional RNAi pathway exists in , highlighting the importance of using multiple reference strains when studying this dangerous pathogen

Endoscopic endonasal transsphenoidal approach in the management of sellar and parasellar lesions: Alternative surgical techniques, results, complications (Part II)

The endoscopic endonasal transsphenoidal approach is a minimally invasive surgical technique for the removal of sellar and parasellar lesions. It allows panoramic vision of the surgical target and surrounding structures, with minimal trauma and a low complication rate. The procedure has been gaining in popularity in recent years. There are now surgical instruments intentionally conceived to respond to the specific characteristics of the neuroendoscopy.&nbsp;The widespread use of the endoscope in transsphenoidal surgery has recently contributed to the extension of the approach superior, inferior or lateral. This expansion carries significant potential for the resection of skull base lesions. For selected patients, the various techniques of the endoscopic endonasal transsphenoidal approach are valid alternatives to transcranial approaches. Macroadenomas, suprasellar or even intraventricular craniopharyngiomas, tuberculum sellae or even planum sphenoidale meningiomas and clival tumors become accessible for removal via an endoscopic approach.&nbsp;The authors review the main alternative surgical techniques of the endoscopic endonasal transsphenoidal approach. They also present the results and the complications of the endoscopic transsphenoidal surgery. Due to an improvement and refinement of the surgical procedures, the endoscopic endonasal transsphenoidal approach can be considered a good choice for the excision of the sellar and parasellar lesions

The clinical features of osteogenesis imperfecta in Vietnam

Purpose Osteogenesis imperfecta (OI) has not been studied in a Vietnamese population before. The aim of this study was to systematically collect epidemiological information, investigate clinical features and create a clinical database of OI patients in Vietnam for future research and treatment strategy development. Method Participants underwent clinical and physical examinations; also medical records were reviewed. Genealogical information was collected and family members’ phenotypical manifestations recorded. Cases were classified according to the Sillence classification. Results In total, 146 OI patients from 120 families were studied: 46 with OI Type I, 46 with Type III and 54 with Type IV. Almost patients had skeletal deformations. One hundred and forty-two had a history of fractures, 117 blue sclera, 89 dentinogenesis imperfecta and 26 hearing loss. The total number of fractures was 1,932. Thirty-four patients had intra-uterine fractures and nine had perinatal fractures. Surgery was performed 163 times in 58 patients; 100 osteosyntheses and 63 osteotomies. Bisphosphonate treatment was used in 37 patients. The number of affected individuals and predominance of severe forms of OI indicate that the disease is under diagnosed in Vietnam, especially in cases without a family history or with mild form of OI. Deformities appeared in all patients with different severity and localisation, affecting mostly the lower limbs. OI medical and surgical treatment rates are low and in most cases surgery was performed due to fractures. Conclusions Compared to previous studies, our results indicate a lower OI prevalence and greater severity of symptoms in the Vietnamese population when compared with other areas. Further investigation, improved diagnosis and treatment are needed to increase the patients’ quality of life