The Bare Necessities: Uncovering Essential and Condition‐Critical Genes with Transposon Sequencing

Summary

Querying gene function in bacteria has been greatly accelerated by the advent of transposon sequencing (Tn‐seq) technologies (related Tn‐seq strategies are known as TraDIS, INSeq, RB‐TnSeq and HITS). Pooled populations of transposon mutants are cultured in an environment and next‐generation sequencing tools are used to determine areas of the genome that are important for bacterial fitness. In this review we provide an overview of Tn‐seq methodologies and discuss how Tn‐seq has been applied, or could be applied, to the study of oral microbiology. These applications include studying the essential genome as a means to rationally design therapeutic agents. Tn‐seq has also contributed to our understanding of well‐studied biological processes in oral bacteria. Other important applications include in vivo pathogenesis studies and use of Tn‐seq to probe the molecular basis of microbial interactions. We also highlight recent advancements in techniques that act in synergy with Tn‐seq such as CRISPR interference and microfluidic chip platforms.

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http://bit.ly/2DpnJDG

Papular Spreaded Necrobiosis Lipoidica: a rare clinical presentation of this pathology

Abstract

A 69‐year‐old Caucasian woman suffering from long‐term diabetes mellitus type II was referred to our dermatology department with cutaneous lesions that appeared 3 years before. They were itchy and non‐tender, and spreaded progressively, with no history of previous trauma. Examination revealed multiple erythematous to yellowish papules on the lower legs, which merged in plaques, of varying shapes and sizes (Fig.1).

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http://bit.ly/2TGpKSN

Papular Spreaded Necrobiosis Lipoidica: a rare clinical presentation of this pathology

Abstract

A 69‐year‐old Caucasian woman suffering from long‐term diabetes mellitus type II was referred to our dermatology department with cutaneous lesions that appeared 3 years before. They were itchy and non‐tender, and spreaded progressively, with no history of previous trauma. Examination revealed multiple erythematous to yellowish papules on the lower legs, which merged in plaques, of varying shapes and sizes (Fig.1).

This article is protected by copyright. All rights reserved.

http://bit.ly/2TGpKSN

A Brief History of Circannual Time

Abstract

The tenet of this review is that innate circannual timing is an ancestral trait that first evolved in free‐living eukaryotic cells some 2000My ago. Marine algae of the genus Allexandrium provide a living unicellular model. This species shows the primitive trait of 'alternation of generations' where the organism alternates between fast replicating vegetative cells in summer, and a dormant cystic cell over winter. The resistant cysts sink into the cold ocean sediments. Remarkably, excystment in spring is governed by an endogenous circannual timing mechanism. Thus, a tiny, short‐lived unicell can utilize a circannual clock as part of the species' life history program. Innate timing allows for major adjustments in physiology and behavior in anticipation of the seasons, and provides an internalized sense of seasonal time for the many species where standard environmental cues are weak or ambiguous. This is a highly adaptive strategy irrespective of the organism's size and longevity. Circannual rhythms are expressed by a diverse range of organisms from flowering plants,to mammals, interwoven into each species life‐history program – the consequence of fore‐ever living in a periodic world. In complex vertebrates, the early division of the zygote potentially carries circannual timer genes into all progeny cells and into all tissues. This supports the concept of a 'clock shop' where cell‐autonomous long‐term rhythms are generated in each tissue, orchestrated by a central circannual pacemaker system. This is analogous to the organization of the circadian timing system. For the circannual time‐scale, specialized thyrotrope cells located in the pars tuberalis (PT) of the pituitary gland and adjacent tanycyte cells located in the ependymal wall of the third cerebral ventricle (3rdV) of the brain act as putative central circannual pacemakers. At a molecular level epigenetically regulated, cyclical remodeling of chromatin, that determines whether specific circannual timer genes are transcriptionary active, or not, is thought to drive the oscillation between the summer and winter phenotypes.

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http://bit.ly/2Spza8H

Surgical site infections after parotidectomy: management and benefits of an antibiotic prophylaxis protocol.

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Surgical site infections after parotidectomy: management and benefits of an antibiotic prophylaxis protocol.

Acta Otorhinolaryngol Ital. 2018 Dec 29;:

Authors: Meccariello G, Montevecchi F, D'Agostino G, Zeccardo E, Al-Raswashdeh MFH, De Vito A, Vicini C

Abstract
The use of perioperative prophylactic antibiotics in uncontaminated head and neck surgery is still controversial. The aim of this study was to assess the efficacy of an institutional antibiotic prophylactic protocol in preventing surgical site infection after parotidectomy. The medical charts of 448 patients who underwent parotidectomy were reviewed. Patients were divided in two groups according the use of perioperative administration of intravenous cefazolin or post-operative week course of antibiotics. Surgical site infection was registered in 29 (6.5%) cases, 16 (5.7%) within the group before the application of protocol and 13 (7.9%) within the antibiotic prophylaxis protocol group. The univariate and multivariate logistic regression analyses showed that predictors for surgical site infection were the amount of drain output ≥ 50 ml in the first post-operative 24 hours (OR: 4.86; 1.59-14.82 95% CI; p < 0.01) and history of a previous parotid acute infection (OR: 13.83; 5.31-36 95% CI; p < 0.01). The majority of post-surgical infections (82%) were treated with intravenous antibiotic therapy. The remnants were treated surgically. Perioperative antibiotic treatment is recommended for patients undergoing parotid gland surgery and intravenous antibiotics during the post-operative course are highly suggested in case of history of previous acute parotid infection and drain output ≥ 50 ml in first 24 hours.

PMID: 30632521 [PubMed - as supplied by publisher]

http://bit.ly/2RnDUuS

Oculorespiratory Reflex During Repair of an Orbital Fracture.

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Oculorespiratory Reflex During Repair of an Orbital Fracture.

JAMA Otolaryngol Head Neck Surg. 2019 Feb 07;:

Authors: Dang RP, Bhatt NK, Rizzi CJ, Chi JJ

PMID: 30730542 [PubMed - as supplied by publisher]

http://bit.ly/2GuWz14

Association of Chronic Rhinosinusitis With Depression and Anxiety in a Nationwide Insurance Population.

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Association of Chronic Rhinosinusitis With Depression and Anxiety in a Nationwide Insurance Population.

JAMA Otolaryngol Head Neck Surg. 2019 Feb 07;:

Authors: Kim JY, Ko I, Kim MS, Yu MS, Cho BJ, Kim DK

Abstract
Importance: Chronic rhinosinusitis (CRS) is associated with a decreased quality of life, affecting physical and emotional aspects of daily function, the latter of which could manifest as depression and anxiety.
Objective: To evaluate the risk of depression and anxiety in CRS, depending on the CRS phenotype (CRS without nasal polyps [CRSsNP] and CRS with nasal polyps [CRSwNP]).
Design, Setting, and Participants: This retrospective nationwide cohort study used population-based insurance data (consisting of data from approximately 1 million patients). The study population included 16 224 patients with CRS and 32 448 individuals without CRS, with propensity score matching between groups according to sociodemographic factors and enrollment year. Data were collected from January 1, 2002, through December 31, 2013, and analyzed from July 1 through November 15, 2018.
Main Outcomes and Measures: Survival analysis, the log-rank test, and Cox proportional hazards regression models were used to calculate the incidence, survival rate, and hazard ratio (HR) of depression and anxiety for each group.
Results: Among the 48 672 individuals included in the study population (58.8% female), the overall incidence of depression during the 11-year follow-up was 1.51-fold higher in the CRS group than in the non-CRS group (24.2 vs 16.0 per 1000 person-years; adjusted HR, 1.54; 95% CI, 1.48-1.61). The incidence of anxiety was also higher in the CRS group than in the comparison group (42.2 vs 27.8 per 1000 person-years; adjusted HR, 1.57; 95% CI, 1.52-1.62). Moreover, the adjusted HRs of developing depression (CRSsNP, 1.61 [95% CI, 1.54-1.69]; CRSwNP, 1.41 [95% CI, 1.32-1.50]) and anxiety (CRSsNP, 1.63 [95% CI, 1.57-1.69]; CRSwNP, 1.45 [95% CI, 1.38-1.52]) were greater in patients with CRSsNP than in those with CRSwNP.
Conclusions and Relevance: This observational study suggests that CRS is associated with an increased incidence of depression and anxiety. Specifically, findings from this study found that patients without nasal polyps showed a higher risk of developing depression and anxiety than those with nasal polyps.

PMID: 30730537 [PubMed - as supplied by publisher]

http://bit.ly/2E1DBxB