The mammalian immune system includes a sophisticated array of antimicrobial mechanisms. However, successful pathogens have developed subversive strategies to detect, modulate, and/or evade immune ...control and clearance. Independent disciplines study host immunology and bacterial pathogenesis, but interkingdom signaling between bacteria and host during natural infection remains poorly understood. An efficient natural host infection system has revealed complex communication between Bordetella spp. and mice, identified novel regulatory mechanisms, and demonstrated that bordetellae can respond to microenvironment and inflammatory status cues. Understanding these bacterial signaling pathways and their complex network that allows precisely timed expression of numerous immunomodulatory factors will serve as a paradigm for other organisms lacking such a powerful experimental infection system.
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Well adapted bacterial pathogens have evolved mechanisms to sense and respond to immune components and host molecules, enabling them to evade, manipulate, or escape their antimicrobial effects.
Bacteria adapt to particular anatomical sites and inflammatory stages by sensing signals specific to each and changing gene expression accordingly.
Two-component systems, sigma factors, sRNAs, and chaperones allow bacteria to respond to environmental changes by orchestrating gene expression to optimize their fitness.
Sensing carbon dioxide, iron starvation, hormones, and likely many other signals can refine the precise expression of virulence factors.
Optimal temporal and spatial expression of virulence factors allows effective manipulation of host immune responses, and allows bacteria to efficiently colonize, infect, persist, and increase transmission amongst hosts.
Wide-field surveys are discovering a growing number of rare transients whose physical origin is not yet well understood. Here we present optical and UV data and analysis of intermediate Palomar ...Transient Factory (iPTF) 16asu, a luminous, rapidly evolving, high-velocity, stripped-envelope supernova (SN). With a rest-frame rise time of just four days and a peak absolute magnitude of mag, the light curve of iPTF 16asu is faster and more luminous than that of previous rapid transients. The spectra of iPTF 16asu show a featureless blue continuum near peak that develops into an SN Ic-BL spectrum on the decline. We show that while the late-time light curve could plausibly be powered by 56Ni decay, the early emission requires a different energy source. Nondetections in the X-ray and radio strongly constrain the energy coupled to relativistic ejecta to be at most comparable to the class of low-luminosity gamma-ray bursts (GRBs). We suggest that the early emission may have been powered by either a rapidly spinning-down magnetar or by shock breakout in an extended envelope of a very energetic explosion. In either scenario a central engine is required, making iPTF 16asu an intriguing transition object between superluminous SNe, SNe Ic-BL, and low-luminosity GRBs.
Purpose: This article reviews the demographics, presentation, cause, clinical findings, and treatment of 12 cases of cervical necrotizing fasciitis of odontogenic origin.
Patients and Methods: A ...retrospective chart review of 12 cases treated between 1987 and 1997 was done.
Results: Most cases resulted from an abscessed mandibular molar. The most common significant medical conditions in the patient's history were diabetes, hypertension, obesity, and substance abuse. All patients were treated surgically within 24 hours of admission. Hyperbaric oxygen (HBO) was used as adjunctive treatment in all cases. The average length of hospital stay was 31 days. All patients recovered.
Conclusion: Early surgical intervention and the use of HBO decreases morbidity and improves the clinical outcome.
The purpose of this study was to examine the effect of distraction osteogenesis surgery on the inferior alveolar nerve (IAN) and on the stability of the occlusion in patients undergoing mandibular ...osteotomy and advancement for correction of severe retrognathia.
Five patients (4 women and 1 man) underwent vertical posterior body osteotomy or bilateral sagittal split ramus osteotomy with the application of a distraction device for advancement of the mandible of 10 to 14 mm. After a period of latency, each mandible was advanced 1 mm per day until the patient achieved a Class I occlusion. Distraction devices were removed after a suitable period of consolidation (4 to 11 months). IAN sensory function was evaluated by 2-point discrimination, response to painful stimulus, and moving brush stroke identification. Testing of the IAN was performed on all patients at 7 different time intervals: preoperative (T0), postsurgery and predistraction (T1), within 7 days after the end of distraction (T2), 3 months after T2 (T3), 6 months after T2 (T4), 9 months after T2 (T5), and 1 year after T2 (T6). The same surgeon performed all IAN testing.
There were no instances of malunion or fibrous union. At the 1-year follow-up, all 5 patients showed no relapse of their advancement as assessed by their maintenance of a Class I occlusion. Radiographic analysis was not done to discern skeletal versus dental stability. All 10 IANs were intact after the initial surgery. As time progressed, all 10 nerves showed improvement of function as measured by 2-point discrimination, response to painful stimulus, and moving brush stroke identification. At 1 year postsurgery, all 10 nerves showed function consistent with or very near presurgery levels.
Stable mandibular advancements of 10 mm and greater can be successfully accomplished by distraction osteogenesis without producing significant damage to the IAN.
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