Solitary metastatic adenocarcinoma of the sternum treated by total sternectomy and chest wall reconstruction using a Gore-Tex patch and myocutaneous flap: a case report

Introduction

Necrotizing soft tissue infection is a life-threatening disease characterized by rapid progressive inflammation and necrosis of the subcutaneous and deep fascia with or without involvement of the adjacent muscles.

Case presentation

We report the case of a 62-year-old Caucasian woman with goiter recurrence who underwent a right-sided hemithyroidectomy. Postoperatively, she developed fulminant mediastinitis caused by group A β-hemolytic streptococcus and septic shock. Our patient survived this rare life-threatening complication.

Conclusions

Initial atypical postoperative symptoms, such as personality changes or an unstable circulatory system, should lead a practitioner to consider the possibility of this severe complication and to begin therapy immediately.     

Amyloidogenic determinants are usually not buried

Background  

Amyloidoses are a group of usually fatal diseases, probably caused by protein misfolding and subsequent aggregation into amyloid fibrillar deposits. The mechanisms involved in amyloid fibril formation are largely unknown and are the subject of current, intensive research. In an attempt to identify possible amyloidogenic regions in proteins for further experimental investigation, we have developed and present here a publicly available online tool that utilizes five different and independently published methods, to form a consensus prediction of amyloidogenic regions in proteins, using only protein primary structure data.     

Collagen fiber orientation at the tendon to bone insertion and its influence on stress concentrations

The tendon to bone insertion serves the mechanical role of transferring loads from a relatively compliant tendon to a relatively rigid bone. The details of the mechanism of load transfer are of great importance, since current surgical procedures for tendon reattachment have high failure rates. We hypothesized that the microscopic structure of the insertion is optimized to minimize stress concentrations associated with this load transfer. To explore this, collagen fiber orientation distributions were measured in the supraspinatus tendons of rats. The angular deviation of fibers was fairly uniform across the insertion, and the mean angles of the local distributions deviated mildly from the tendon axis. To explore how these observed property distributions could influence load transfer, these distributions were used to derive material properties for an idealized two-dimensional mechanical model of an insertion. Comparison between stress concentrations in this idealized model and those in three comparison models suggests that the microstructure serves to (1) simultaneously reduce stress concentrations and material mass, and (2) shield the insertion's outward splay from the highest stresses.     

Status and structure of the griffon vulture (Gyps fulvus) population in Crete

Griffon vulture (Gyps fulvus) population surveys were conducted during 1996–2002 in the island of Crete (Greece) to document population status and structure. Fieldwork was carried out during the breeding period when birds could be monitored in their colonies. Total population size was estimated at 379 individuals (range = 341–417) with adult birds comprising 63%. The breeding population was estimated at 141 pairs, which were distributed on an average in 23 colonies per year (range = 16–30) while the mean number of breeding pairs that laid eggs was 98 (range= 64–126). Crete thus supports the largest insular population of the species in the world and hosts 70–80% of the breeding population of the species in Greece. Population density was estimated at 6.9 individuals/100 km², 2.6 breeding pairs/100 km² and 1.8 nesting pairs/100 km². The average home range of an occupied colony (i.e., breeding group) was estimated at ca. 204 km² producing a theoretical foraging range of 8 km radius around the breeding cliff. No trends in the total number of individuals and breeding pairs appeared to exist, although significant differences in population size of individual colonies occurred between the years. The majority of the population was concentrated in small-sized colonies, which showed a low occupancy rate. The number of abandoned sites and the colonization of new ones could represent a shift of breeding pairs to alternative colonies provoked by local food abundance and conspesific attraction.     

Principal methods for isolation and identification of soil microbial communities

Soil microbial populations play crucial role in soil properties and influence below-ground ecosystem processes. Microbial composition and functioning changes the soil quality through decomposition of organic matter, recycling of nutrients, and biological control of parasites of plants. Moreover, the discovery that soil microbes may translate into benefits for biotechnology, management of agricultural, forest, and natural ecosystems, biodegradation of pollutants, and waste treatment systems maximized the need of scientists for the isolation and their characterization. Operations such as the production of antibiotics and enzymic activities from microorganisms of soil constitute objectives of industry in her effort to cope with the increase of population of earth and disturbance of environment and may ameliorate the effects of global climate change. In the past decades, new biochemical and molecular techniques have been developed in our effort to identify and classify soil bacteria. The goal of measuring the soil microbial diversity is difficult because of the limited knowledge about bacteria species and classification through families and orders. Molecular techniques extend our knowledge about microbial diversity and help the taxonomy of species. Measuring and monitoring soil microbial communities can lead us to better understanding of their composition and function in many ecosystem processes.     

The Geminin and Idas Coiled Coils Preferentially Form a Heterodimer That Inhibits Geminin Function in DNA Replication Licensing

Geminin is an important regulator of proliferation and differentiation in metazoans, which predominantly inhibits the DNA replication licensing factor Cdt1, preventing genome over-replication. We show that Geminin preferentially forms stable coiled-coil heterodimers with its homologue, Idas. In contrast to Idas-Geminin heterodimers, Idas homodimers are thermodynamically unstable and are unlikely to exist as a stable macromolecule under physiological conditions. The crystal structure of the homology regions of Idas in complex with Geminin showed a tight head-to-head heterodimeric coiled-coil. This Idas-Geminin heterodimer binds Cdt1 less strongly than Geminin-Geminin, still with high affinity (∼30 nm), but with notably different thermodynamic properties. Consistently, in Xenopus egg extracts, Idas-Geminin is less active in licensing inhibition compared with a Geminin-Geminin homodimer. In human cultured cells, ectopic expression of Idas leads to limited over-replication, which is counteracted by Geminin co-expression. The properties of the Idas-Geminin complex suggest it as the functional form of Idas and provide a possible mechanism to modulate Geminin activity.