Natural history, clinical pattern, and surgical considerations of pneumatosis intestinalis

<p>Abstract</p> <p>Objective</p> <p>Pneumatosis intestinalis has been increasingly detected in recent years with the more frequent use of computed tomography for abdominal imaging of the intestine. The underlying causes of the gas found during radiographic studies of the bowel wall can vary widely and different hypotheses regarding its pathophysiology have been postulated. Pneumatosis intestinalis often represents a benign condition and should not be considered an argument for surgery. However, it can also require life-threatening surgery in some cases, and this can be a difficult decision in some patients.</p> <p>Methods</p> <p>The spectrum of pneumatosis intestinalis is discussed here based on various computed tomographic and surgical findings in patients who presented at our University Medical Centre in 2003-2008. We have also systematically reviewed the literature to establish the current understanding of its aetiology and pathophysiology, and the possible clinical conditions associated with pneumatosis intestinalis and their management.</p> <p>Results</p> <p>Pneumatosis intestinalis is a primary radiographic finding. After its diagnosis, its specific pathogenesis should be ascertained because the appropriate therapy is related to the underlying cause of pneumatosis intestinalis, and this is sometimes difficult to define. Surgical treatment should be considered urgent in symptomatic patients presenting with an acute abdomen, signs of ischemia, or bowel obstruction. In asymptomatic patients with otherwise inconspicuous findings, the underlying disease should be treated first, rather than urgent exploratory surgery considered. Extensive and comprehensive information on the pathophysiology and clinical findings of pneumatosis intestinalis is provided here and is incorporated into a treatment algorithm.</p> <p>Conclusions</p> <p>The information presented here allows a better understanding of the radiographic diagnosis and underlying aetiology of pneumatosis intestinalis, and may facilitate the decision-making process in this context, thus providing fast and adequate therapy to particular patients.</p

Persistence of root-colonizing Pseudomonas protegens in herbivorous insects throughout different developmental stages and dispersal to new host plants.

The discovery of insecticidal activity in root-colonizing pseudomonads, best-known for their plant-beneficial effects, raised fundamental questions about the ecological relevance of insects as alternative hosts for these bacteria. Since soil bacteria are limited in their inherent abilities of dispersal, insects as vectors might be welcome vehicles to overcome large distances. Here, we report on the transmission of the root-colonizing, plant-beneficial and insecticidal bacterium Pseudomonas protegens CHA0 from root to root by the cabbage root fly, Delia radicum. Following ingestion by root-feeding D. radicum larvae, CHA0 persisted inside the insect until the pupal and adult stages. The emerging flies were then able to transmit CHA0 to a new plant host initiating bacterial colonization of the roots. CHA0 did not reduce root damages caused by D. radicum and had only small effects on Delia development suggesting a rather commensal than pathogenic relationship. Interestingly, when the bacterium was fed to two highly susceptible lepidopteran species, most of the insects died, but CHA0 could persist throughout different life stages in surviving individuals. In summary, this study investigated for the first time the interaction of P. protegens CHA0 and related strains with an insect present in their rhizosphere habitat. Our results suggest that plant-colonizing pseudomonads have different strategies for interaction with insects. They either cause lethal infections and use insects as food source or they live inside insect hosts without causing obvious damages and might use insects as vectors for dispersal, which implies a greater ecological versatility of these bacteria than previously thought

Elucidating the genomic history of commercially used Bacillus thuringiensis subsp. tenebrionis strain NB176

Bacillus thuringiensis subsp. tenebrionis (Btt) produces a coleopteran-specific crystal protoxin protein (Cry3Aa δ-endotoxin). After its discovery in 1982, the strain NB125 (DSM 5526) was eventually registered in 1990 to control the Colorado potato beetle (Leptinotarsa decemlineata). Gamma-irradiation of NB125 resulted in strain NB176-1 (DSM 5480) that exhibited higher cry3Aa production and became the active ingredient of the plant protection product Novodor® FC. Here, we report a comparative genome analysis of the parental strain NB125, its derivative NB176-1 and the current commercial production strain NB176. The entire genome sequences of the parental and derivative strains were deciphered by a hybrid de novo approach using short (Illumina) and long (Nanopore) read sequencing techniques. Genome assembly revealed a chromosome of 5.4 to 5.6 Mbp and six plasmids with a size range from 14.9 to 250.5 kbp for each strain. The major differences among the original NB125 and the derivative strains NB176-1 and NB176 were an additional copy of the cry3Aa gene, which translocated to another plasmid as well as a chromosomal deletion (~ 178 kbp) in NB176. The assembled genome sequences were further analyzed in silico for the presence of virulence and antimicrobial resistance (AMR) genes

Low lying spectrum of weak-disorder quantum waveguides

We study the low-lying spectrum of the Dirichlet Laplace operator on a randomly wiggled strip. More precisely, our results are formulated in terms of the eigenvalues of finite segment approximations of the infinite waveguide. Under appropriate weak-disorder assumptions we obtain deterministic and probabilistic bounds on the position of the lowest eigenvalue. A Combes-Thomas argument allows us to obtain so-called 'initial length scale decay estimates' at they are used in the proof of spectral localization using the multiscale analysis.Comment: Accepted for publication in Journal of Statistical Physics http://www.springerlink.com/content/0022-471

Pulmonary sclerosing hemangioma in a 21-year-old male with metastatic hereditary non-polyposis colorectal cancer: Report of a case

<p>Abstract</p> <p>Background</p> <p>Pulmonary sclerosing hemangioma (SH) is a rare tumor of the lung predominantly affecting Asian women in their fifth decade of life. SH is thought to evolve from primitive respiratory epithelium and mostly shows benign biological behavior; however, cases of lymph node metastases, local recurrence and multiple lesions have been described.</p> <p>Case Presentation</p> <p>We report the case of a 21-year-old Caucasian male with a history of locally advanced and metastatic rectal carcinoma (UICC IV; pT4, pN1, M1(hep)) that was eventually identified as having hereditary non-polyposis colorectal cancer (HNPCC, Lynch syndrome). After neoadjuvant chemotherapy followed by low anterior resection, adjuvant chemotherapy and metachronous partial hepatectomy, he was admitted for treatment of newly diagnosed bilateral pulmonary metastases. Thoracic computed tomography showed a homogenous, sharply marked nodule in the left lower lobe. We decided in favor of atypical resection followed by systematic lymphadenectomy. Histopathological analysis revealed the diagnosis of SH.</p> <p>Conclusions</p> <p>Cases have been published with familial adenomatous polyposis (FAP) and simultaneous SH. FAP, Gardner syndrome and Li-Fraumeni syndrome, however, had been ruled out in the present case. To the best of our knowledge, this is the first report describing SH associated with Lynch syndrome.</p

A Rickettsiella Bacterium from the Hard Tick, Ixodes woodi: Molecular Taxonomy Combining Multilocus Sequence Typing (MLST) with Significance Testing

Hard ticks (Acari: Ixodidae) are known to harbour intracellular bacteria from several phylogenetic groups that can develop both mutualistic and pathogenic relationships to the host. This is of particular importance for public health as tick derived bacteria can potentially be transmitted to mammals, including humans, where e.g. Rickettsia or Coxiella act as severe pathogens. Exact molecular taxonomic identification of tick associated prokaryotes is a necessary prerequisite of the investigation of their relationship to both the tick and possible vertebrate hosts. Previously, an intracellular bacterium had been isolated from a monosexual, parthenogenetically reproducing laboratory colony of females of the hard tick, Ixodes woodi Bishopp, and had preliminarily been characterized as a “Rickettsiella-related bacterium”. In the present molecular taxonomic study that is based on phylogenetic reconstruction from both 16 S ribosomal RNA and protein-encoding marker sequences complemented with likelihood-based significance testing, the bacterium from I. woodi has been identified as a strain of the taxonomic species Rickettsiella grylli. It is the first time that a multilocus sequence typing (MLST) approach based on a four genes comprising MLST scheme has been implemented in order to classify a Rickettsiella-like bacterium to this species. The study demonstrated that MLST holds potential for a better resolution of phylogenetic relationships within the genus Rickettsiella, but requires sequence determination from further Rickettsiella-like bacteria in order to complete the current still fragmentary picture of Rickettsiella systematics