Trunk, abdomen, and pressure sore reconstruction

LEARNING OBJECTIVES: After reading this article, the participant should be able to: 1. Describe the principles of wound closure, torso reconstruction, and pressure sore reconstruction. 2. Outline standard options to treat defects of the chest, abdomen, and back and pressure ulcers in all anatomical areas. 3. Manage and prevent pressure ulcers. SUMMARY: Chest wall reconstruction is indicated following tumor resection, radiation wound breakdown, or intrathoracic sepsis. Principles of wound closure and chest wall stabilization, where indicated, are discussed. Principles of abdominal wall reconstruction continue to evolve with the introduction of newer bioprosthetics and the application of functional concepts for wound closure. The authors illustrate these principles using commonly encountered clinical scenarios and guidelines to achieve predictable results. Pressure ulcers continue to be devastating complications to patients' health and a functional hazard when they occur in the bedridden, in patients with spinal cord injuries, and in patients with neuromuscular disease. Management of pressure ulcers is also very expensive. The authors describe standard options to treat defects of the chest, abdomen, and back and pressure ulcers in all anatomical areas. A comprehensive understanding of principles and techniques will allow practitioners to approach difficult issues of torso reconstruction and pressure sores with a rational confidence and an expectation of generally satisfactory outcomes. With pressure ulcers, prevention remains the primary goal. Patient education and compliance coupled with a multidisciplinary team approach can reduce their occurrence significantly. Surgical management includes appropriate patient selection, adequate débridement, soft-tissue coverage, and use of flaps that will not limit future reconstructions if needed. Postoperatively, a strict protocol should be adapted to ensure the success of the flap procedure. Several myocutaneous flaps commonly used for the surgical management of pressure are discussed. Commonly used flaps in chest and abdominal wall reconstruction are discussed and these should be useful for the practicing plastic surgeon.     

The role of nodules in the tolerance of common bean to iron deficiency

Iron is vital for the establishment and function of symbiotic root nodules of legumes. Although abundant in the environment, Fe is often a limiting nutrient for plant growth due to its low solubility and availability in some soils. We have studied the mechanism of iron uptake in the root nodules of common bean to evaluate the role of nodules in physiological responses to iron deficiency. Based on experiments using full or partial submergence of nodulated roots in the nutrient solution, our results show that the nodules were affected only slightly under iron deficiency, especially when the nodules were submerged in nutrient solution in the tolerant cultivar. In addition, fully submerged root nodules showed enhanced acidification of the nutrient solution and showed higher ferric chelate reductase activity than that of partially submerged roots in plants cultivated under Fe deficiency. The main results obtained in this work suggest that in addition to preferential Fe allocation from the root system to the nodules, this symbiotic organ probably develops some mechanisms to respond to iron deficiency. These mechanisms were implied especially in nodule Fe absorption efficiency and in the ability of this organ to take up Fe directly from the medium.     

Poultry Slaughtering Practices in Rural Communities of Bangladesh and Risk of Avian Influenza Transmission: A Qualitative Study

Slaughtering sick poultry is a risk factor for human infection with highly pathogenic avian influenza and is a common practice in Bangladesh. This paper describes human exposures to poultry during slaughtering process and the customs and rituals influencing these practices in two Bangladeshi rural communities. In 2009, we conducted 30 observations to observe slaughtering practices and 110 in-depth and short interviews and 36 group discussions to explore reasons behind those practices. The villagers reported slaughtering 103 poultry, including 20 sick poultry during 2 months. During different stages of slaughtering, humans, the environment, healthy poultry, and other animals were exposed to poultry blood and body parts. Women performed most of the slaughtering tasks, including evisceration. Defeathering required the most time and involved several persons. During festivals, ceremonies, and rituals, many people gathered and participated in the slaughtering of poultry. Exposure to poultry slaughtering created numerous opportunities for potential avian influenza transmission. Strategies that can be further tested to determine if they reduce the risk of transmission include skinning the carcasses of sick poultry, using hot water for defeathering and cleaning, using a bucket to contain slaughtering blood and carcass, burying the offal and encouraging handwashing.     

A new species of the rare buthid scorpion genus Lissothus Vachon, 1948 from Central Algeria (Scorpiones,Buthidae)

Taxonomic considerations are given for the genus Lissothus Vachon, 1948 (Scorpiones, Buthidae). Two species are currently known, Lissothus bernardi Vachon, 1948 from Libya and Lissothus occidentalis Vachon, 1950 from Mauritania. In this contribution, a new species, Lissothus chaambi sp. n., is described from the desert of Central Algeria. The new species is most closely related to L. bernardi. The geographical distribution of the genus is discussed.     

Whole Mitochondrial and Plastid Genome SNP Analysis of Nine Date Palm Cultivars Reveals Plastid Heteroplasmy and Close Phylogenetic Relationships among Cultivars

Date palm is a very important crop in western Asia and northern Africa, and it is the oldest domesticated fruit tree with archaeological records dating back 5000 years. The huge economic value of this crop has generated considerable interest in breeding programs to enhance production of dates. One of the major limitations of these efforts is the uncertainty regarding the number of date palm cultivars, which are currently based on fruit shape, size, color, and taste. Whole mitochondrial and plastid genome sequences were utilized to examine single nucleotide polymorphisms (SNPs) of date palms to evaluate the efficacy of this approach for molecular characterization of cultivars. Mitochondrial and plastid genomes of nine Saudi Arabian cultivars were sequenced. For each species about 60 million 100 bp paired-end reads were generated from total genomic DNA using the Illumina HiSeq 2000 platform. For each cultivar, sequences were aligned separately to the published date palm plastid and mitochondrial reference genomes, and SNPs were identified. The results identified cultivar-specific SNPs for eight of the nine cultivars. Two previous SNP analyses of mitochondrial and plastid genomes identified substantial intra-cultivar ( = intra-varietal) polymorphisms in organellar genomes but these studies did not properly take into account the fact that nearly half of the plastid genome has been integrated into the mitochondrial genome. Filtering all sequencing reads that mapped to both organellar genomes nearly eliminated mitochondrial heteroplasmy but all plastid SNPs remained heteroplasmic. This investigation provides valuable insights into how to deal with interorganellar DNA transfer in performing SNP analyses from total genomic DNA. The results confirm recent suggestions that plastid heteroplasmy is much more common than previously thought. Finally, low levels of sequence variation in plastid and mitochondrial genomes argue for using nuclear SNPs for molecular characterization of date palm cultivars.     

Evaluation of a gp63–PCR Based Assay as a Molecular Diagnosis Tool in Canine Leishmaniasis in Tunisia

A gp63PCR method was evaluated for the detection and characterization of Leishmania (Leishmania) (L.) parasites in canine lymph node aspirates. This tool was tested and compared to other PCRs based on the amplification of 18S ribosomal genes, a L. infantum specific repetitive sequence and kinetoplastic DNA minicircles, and to classical parasitological (smear examination and/or culture) or serological (IFAT) techniques on a sample of 40 dogs, originating from different L. infantum endemic regions in Tunisia. Sensitivity and specificity of all the PCR assays were evaluated on parasitologically confirmed dogs within this sample (N = 18) and control dogs (N = 45) originating from non–endemic countries in northern Europe and Australia. The gp63 PCR had 83.5% sensitivity and 100% specificity, a performance comparable to the kinetoplast PCR assay and better than the other assays. These assays had comparable results when the gels were southern transferred and hybridized with a radioactive probe. As different infection rates were found according to the technique, concordance of the results was estimated by (κ) test. Best concordance values were between the gp63PCR and parasitological methods (74.6%, 95% confidence intervals CI: 58.8–95.4%) or serology IFAT technique (47.4%, 95% CI: 23.5–71.3%). However, taken together Gp63 and Rib assays covered most of the samples found positive making of them a good alternative for determination of infection rates. Potential of the gp63PCR-RFLP assay for analysis of parasite genetic diversity within samples was also evaluated using 5 restriction enzymes. RFLP analysis confirmed assignment of the parasites infecting the dogs to L. infantum species and illustrated occurrence of multiple variants in the different endemic foci. Gp63 PCR assay thus constitutes a useful tool in molecular diagnosis of L. infantum infections in dogs in Tunisia.     

Differential Interaction Kinetics of a Bipolar Structure-Specific Endonuclease with DNA Flaps Revealed by Single-Molecule Imaging

As DNA repair enzymes are essential for preserving genome integrity, understanding their substrate interaction dynamics and the regulation of their catalytic mechanisms is crucial. Using single-molecule imaging, we investigated the association and dissociation kinetics of the bipolar endonuclease NucS from Pyrococcus abyssi (Pab) on 5′ and 3′-flap structures under various experimental conditions. We show that association of the PabNucS with ssDNA flaps is largely controlled by diffusion in the NucS-DNA energy landscape and does not require a free 5′ or 3′ extremity. On the other hand, NucS dissociation is independent of the flap length and thus independent of sliding on the single-stranded portion of the flapped DNA substrates. Our kinetic measurements have revealed previously unnoticed asymmetry in dissociation kinetics from these substrates that is markedly modulated by the replication clamp PCNA. We propose that the replication clamp PCNA enhances the cleavage specificity of NucS proteins by accelerating NucS loading at the ssDNA/dsDNA junctions and by minimizing the nuclease interaction time with its DNA substrate. Our data are also consistent with marked reorganization of ssDNA and nuclease domains occurring during NucS catalysis, and indicate that NucS binds its substrate directly at the ssDNA-dsDNA junction and then threads the ssDNA extremity into the catalytic site. The powerful techniques used here for probing the dynamics of DNA-enzyme binding at the single-molecule have provided new insight regarding substrate specificity of NucS nucleases.     

Dynamics of Japanese Encephalitis Virus Transmission among Pigs in Northwest Bangladesh and the Potential Impact of Pig Vaccination

Background

Japanese encephalitis (JE) virus infection can cause severe disease in humans, resulting in death or permanent neurologic deficits among survivors. Studies indicate that the incidence of JE is high in northwestern Bangladesh. Pigs are amplifying hosts for JE virus (JEV) and a potentially important source of virus in the environment. The objectives of this study were to describe the transmission dynamics of JEV among pigs in northwestern Bangladesh and estimate the potential impact of vaccination to reduce incidence among pigs.

Methodology/Principal Findings

We conducted a comprehensive census of pigs in three JE endemic districts and tested a sample of them for evidence of previous JEV infection. We built a compartmental model to describe JEV transmission dynamics in this region and to estimate the potential impact of pig vaccination. We identified 11,364 pigs in the study area. Previous JEV infection was identified in 30% of pigs with no spatial differences in the proportion of pigs that were seropositive across the study area. We estimated that JEV infects 20% of susceptible pigs each year and the basic reproductive number among pigs was 1.2. The model suggest that vaccinating 50% of pigs each year resulted in an estimated 82% reduction in annual incidence in pigs.

Conclusions/Significance

The widespread distribution of historic JEV infection in pigs suggests they may play an important role in virus transmission in this area. Future studies are required to understand the contribution of pig infections to JE risk in humans and the potential impact of pig vaccination on human disease.