The Cellular and Physiological Basis for Lung Repair and Regeneration: Past, Present, and Future.

The respiratory system, which includes the trachea, airways, and distal alveoli, is a complex multi-cellular organ that intimately links with the cardiovascular system to accomplish gas exchange. In this review and as members of the NIH/NHLBI-supported Progenitor Cell Translational Consortium, we discuss key aspects of lung repair and regeneration. We focus on the cellular compositions within functional niches, cell-cell signaling in homeostatic health, the responses to injury, and new methods to study lung repair and regeneration. We also provide future directions for an improved understanding of the cell biology of the respiratory system, as well as new therapeutic avenues

Genetic Studies of Sulfadiazine-resistant and Methionine-requiring \u3cem\u3eNeisseria\u3c/em\u3e Isolated From Clinical Material

Deoxyribonucleate (DNA) preparations were extracted from Neisseria meningitidis (four isolates from spinal fluid and blood) and N. gonorrhoeae strains, all of which were resistant to sulfadiazine upon primary isolation. These DNA preparations, together with others from in vitro mutants of N. meningitidis and N. perflava, were examined in transformation tests by using as recipient a drug-susceptible strain of N. meningitidis (Ne 15 Sul-s Met+) which was able to grow in a methionine-free defined medium. The sulfadiazine resistance typical of each donor was introduced into the uniform constitution of this recipient. Production of p-aminobenzoic acid was not significantly altered thereby. Transformants elicited by DNA from the N. meningitidis clinical isolates were resistant to at least 200 μg of sulfadiazine/ml, and did not show a requirement for methionine (Sul-r Met+). DNA from six strains of N. gonorrhoeae, which were isolated during the period of therapeutic use of sulfonamides, conveyed lower degrees of resistance and, invariably, a concurrent methionine requirement (Sul-r/Met−). The requirement of these transformants, and that of in vitro mutants selected on sulfadiazine-agar, was satisfied by methionine, but not by vitamin B12, homocysteine, cystathionine, homoserine, or cysteine. Sul-r Met+ and Sul-r/Met− loci could coexist in the same genome, but were segregated during transformation. On the other hand, the dual Sul-r/Met− properties were not separated by recombination, but were eliminated together. DNA from various Sul-r/Met− clones tested against recipients having nonidentical Sul-r/Met− mutant sites yielded Sul-s Met+ transformants. The met locus involved is genetically complex, and will be a valuable tool for studies of genetic fine structure of members of Neisseria, and of genetic homology between species

A multicenter experience with the Talent endovascular graft for the treatment of abdominal aortic aneurysms

AbstractObjective: The Talent endovascular graft has been used in the treatment of abdominal aortic aneurysms (AAAs) in more than 13,000 patients worldwide. However, information regarding the results of its use has been limited. This report describes the experience with 368 patients with AAAs who underwent treatment at four medical centers as part of an investigator-sponsored investigational device exemption trial. Methods: Patients with AAAs were enrolled at four sites during a 32-month period from January 1999 to July 2001. All patients underwent treatment for infrarenal AAA with the Talent endovascular graft. Repair was performed with transrenal stent fixation under epidural (362/368 patients; 98.3%), local (4/368 patients; 1.1%), or general (2/368 patients; 0.5%) anesthesia. The average diameters were: maximum aortic aneurysm, 6.2 ± 1.2 cm; proximal aortic fixation site, 2.6 ± 0.4 cm; and distal iliac fixation site, 1.4 ± 0.6 cm. Bifurcated grafts were used in 276 of 366 patients (75%), aortouniiliac in 57 of 366 patients (16%), and tube aortoaortic in 33 of 366 patients (9%). Multiple comorbid medical conditions were present in all patients (average, 4.7 conditions/patient). The mean age was 75.8 years, and 85% of the patients were male. Follow-up period ranged from 2 to 33 months (mean, 7.3 months). Results: Endovascular graft deployment was accomplished in 366 of 368 patients. In the 263 patients followed for at least 6 months after endovascular repair, AAA diameter decreased by 5 mm or more in 83 patients (32%); diameter remained unchanged (change < 5 mm) in 157 patients (60%) and increased by 5 mm or more in 23 patients (8.7%). Major morbidity occurred in 46 of 368 patients (12.5%), and minor morbidity occurred in 31 of 368 (8.4%). The 30-day mortality rate was 1.9%. Secondary procedures were performed in 32 patients (8.7%). Late rupture occurred in two patients, and late deaths unrelated to AAA occurred in 32 patients (8.7%) during the follow-up period. The primary technical success rate for all patients was 93.4%. The 30-day primary procedural success rate was 73.3%. The 30-day secondary procedural success rate was significantly higher at 85.8%. Computed tomographic scan was performed within 1 month after surgery in 349 patients. An endoleak was present in 43 of 349 patients (12.3%). These endoleaks were comprised of 10 attachment site (type I; 2.9%), 31 retrograde side-branch (type II; 8.9%), and two transgraft (type III; 0.6%). Conclusion: These midterm findings show a high degree of technical and procedural success achieved in a patient population with extensive comorbid medical illnesses with low perioperative morbidity and mortality rates. Further follow-up study will be necessary to determine the effectiveness of the Talent endograft for the long-term treatment of AAA. (J Vasc Surg 2002;35:1123-8.

Measure representation and multifractal analysis of complete genomes

This paper introduces the notion of measure representation of DNA sequences. Spectral analysis and multifractal analysis are then performed on the measure representations of a large number of complete genomes. The main aim of this paper is to discuss the multifractal property of the measure representation and the classification of bacteria. From the measure representations and the values of the $D_{q}$ spectra and related $C_{q}$ curves, it is concluded that these complete genomes are not random sequences. In fact, spectral analyses performed indicate that these measure representations considered as time series, exhibit strong long-range correlation. For substrings with length K=8, the $D_{q}$ spectra of all organisms studied are multifractal-like and sufficiently smooth for the $C_{q}$ curves to be meaningful. The $C_{q}$ curves of all bacteria resemble a classical phase transition at a critical point. But the 'analogous' phase transitions of chromosomes of non-bacteria organisms are different. Apart from Chromosome 1 of {\it C. elegans}, they exhibit the shape of double-peaked specific heat function.Comment: 12 pages with 9 figures and 1 tabl

Immunisation coverage in the rural Eastern Cape – are we getting the basics of primary care right? Results from a longitudinal prospective cohort study

Background. Immunisations are one of the most cost-effective public health interventions available and South Africa (SA) has implemented a comprehensive immunisation schedule. However, there is disagreement about the level of immunisation coverage in the country and few studies document the immunisation coverage in rural areas.Objective. To examine the successful and timely delivery of immunisations to children during the first 2 years of life in a deeply rural part of the Eastern Cape Province of SA.Methods. From January to April 2013, a cohort of sequential births (N=470) in the area surrounding Zithulele Hospital in the OR Tambo District of the Eastern Cape was recruited and followed up at home at 3, 6, 9, 12 and 24 months post birth, up to May 2015. Immunisation coverage was determined using Road-to-Health cards.Results. The percentages of children with all immunisations up to date at the time of interview were: 48.6% at 3 months, 73.3% at 6 months, 83.9% at 9 months, 73.3% at 12 months and 73.2% at 24 months. Incomplete immunisations were attributed to stock-outs (56%), lack of awareness of the immunisation schedule or of missed immunisations by the mother (16%) and lack of clinic attendance by the mother (19%). Of the mothers who had visited the clinic for baby immunisations, 49.8% had to make multiple visits because of stock-outs. Measles coverage (of at least one dose) was 85.2% at 1 year and 96.3% by 2 years, but 20.6% of babies had not received a second measles dose (due at 18 months) by 2 years. Immunisations were often given late, particularly the 14-week immunisations.Conclusions. Immunisation rates in the rural Eastern Cape are well below government targets and indicate inadequate provision of basic primary care. Stock-outs of basic childhood immunisations are common and are, according to mothers, the main reason for their children’s immunisations not being up to date. There is still much work to be done to ensure that the basics of disease prevention are being delivered at rural clinics in the Eastern Cape, despite attempts to re-engineer primary healthcare in SA

Approaches that will yield greater success when implementing self-administered electronic data capture ICT systems in the developing world with an illiterate or semi-literate population

The Information Technology (IT) Group at the Population Council responded to a need for a technology solution that would help researchers obtain more accurate responses to survey questions that concerned subject matter of a sensitive nature. The IT Group had three goals: (1) to enhance research by obtaining the best data possible, (2) to operate successfully in the local environment and be welcomed by the local populations, and (3) to increase the efficiency and cost-effectiveness of the survey process. This paper outlines approaches to consider when designing and implementing self-administered information and communications technology (ICT) questionnaires in developing countries, and reviews the problems and issues we encountered and how we overcame them. Many of the approaches outlined may also be used in general for ICT-related projects in the developing world. To meet future challenges, we have begun an effort to build a prototype system that would operate on a variety of devices—when connected to the internet or not (securely storing the data when the system is offline)—and provide an administrative application to step through simple screens to build a self-administered questionnaire with the most frequently used functions

The disulphide isomerase DsbC cooperates with the oxidase DsbA in a DsbD-independent manner

In Escherichia coli , DsbA introduces disulphide bonds into secreted proteins. DsbA is recycled by DsbB, which generates disulphides from quinone reduction. DsbA is not known to have any proofreading activity and can form incorrect disulphides in proteins with multiple cysteines. These incorrect disulphides are thought to be corrected by a protein disulphide isomerase, DsbC, which is kept in the reduced and active configuration by DsbD. The DsbC/DsbD isomerization pathway is considered to be isolated from the DsbA/DsbB pathway. We show that the DsbC and DsbA pathways are more intimately connected than previously thought. dsbA - dsbC - mutants have a number of phenotypes not exhibited by either dsbA - , dsbC - or dsbA - dsbD - mutations: they exhibit an increased permeability of the outer membrane, are resistant to the lambdoid phage φ80, and are unable to assemble the maltoporin LamB. Using differential two-dimensional liquid chromatographic tandem mass spectrometry/mass spectrometry analysis, we estimated the abundance of about 130 secreted proteins in various dsb - strains. dsbA - dsbC - mutants exhibit unique changes at the protein level that are not exhibited by dsbA - dsbD - mutants. Our data indicate that DsbC can assist DsbA in a DsbD-independent manner to oxidatively fold envelope proteins. The view that DsbC's function is limited to the disulphide isomerization pathway should therefore be reinterpreted.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/72894/1/MMI_6030_sm_Tables_S1-S4.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/72894/2/MMI_tables_s1-s4.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/72894/3/j.1365-2958.2007.06030.x.pd

The Monofunctional Catalase KatE of Xanthomonas axonopodis pv. citri Is Required for Full Virulence in Citrus Plants

BACKGROUND: Xanthomonas axonopodis pv. citri (Xac) is an obligate aerobic phytopathogen constantly exposed to hydrogen peroxide produced by normal aerobic respiration and by the plant defense response during plant-pathogen interactions. Four putative catalase genes have been identified in silico in the Xac genome, designated as katE, catB, srpA (monofunctional catalases) and katG (bifunctional catalase). METHODOLOGY/PRINCIPAL FINDINGS: Xac catalase activity was analyzed using native gel electrophoresis and semi-quantitative RT-PCR. We demonstrated that the catalase activity pattern was regulated in different growth stages displaying the highest levels during the stationary phase. KatE was the most active catalase in this phase of growth. At this stage cells were more resistant to hydrogen peroxide as was determined by the analysis of CFU after the exposition to different H(2)O(2) concentrations. In addition, Xac exhibited an adaptive response to hydrogen peroxide, displaying higher levels of catalase activity and H(2)O(2) resistance after treatment with sub-lethal concentrations of the oxidant. In the plant-like medium XVM2 the expression of KatE was strongly induced and in this medium Xac was more resistant to H(2)O(2). A XackatE mutant strain was constructed by insertional mutagenesis. We observed that catalase induction in stationary phase was lost meanwhile the adaptive response to peroxide was maintained in this mutant. Finally, the XackatE strain was assayed in planta during host plant interaction rendering a less aggressive phenotype with a minor canker formation. CONCLUSIONS: Our results confirmed that in contrast to other Xanthomonas species, Xac catalase-specific activity is induced during the stationary phase of growth in parallel with the bacterial resistance to peroxide challenge. Moreover, Xac catalases expression pattern is modified in response to any stimuli associated with the plant or the microenvironment it provides. The catalase KatE has been shown to have an important function for the colonization and survival of the bacterium in the citrus plant during the pathogenic process. Our work provides the first genetic evidence to support a monofunctional catalase as a virulence factor in Xac

Efficient mouse transgenesis using Gateway-compatible ROSA26 locus targeting vectors and F1 hybrid ES cells

The ability to rapidly and efficiently generate reliable Cre/loxP conditional transgenic mice would greatly complement global high-throughput gene targeting initiatives aimed at identifying gene function in the mouse. We report here the generation of Cre/loxP conditional ROSA26-targeted ES cells within 3–4 weeks by using Gateway® cloning to build the target vectors. The cDNA of the gene of interest can be expressed either directly by the ROSA26 promoter providing a moderate level of expression or by a CAGG promoter placed in the ROSA26 locus providing higher transgene expression. Utilization of F1 hybrid ES cells with exceptional developmental potential allows the production of germ line transmitting, fully or highly ES cell-derived mice by aggregation of cells with diploid embryos. The presented streamlined procedures accelerate the examination of phenotypical consequences of transgene expression. It also provides a unique tool for comparing the biological activity of polymorphic or splice variants of a gene, or products of different genes functioning in the same or parallel pathways in an overlapping manner

RMDAP: A Versatile, Ready-To-Use Toolbox for Multigene Genetic Transformation

Background: The use of transgenes to improve complex traits in crops has challenged current genetic transformation technology for multigene transfer. Therefore, a multigene transformation strategy for use in plant molecular biology and plant genetic breeding is thus needed. Methodology/Principal Findings: Here we describe a versatile, ready-to-use multigene genetic transformation method, named the Recombination-assisted Multifunctional DNA Assembly Platform (RMDAP), which combines many of the useful features of existing plant transformation systems. This platform incorporates three widely-used recombination systems, namely, Gateway technology, in vivo Cre/loxP and recombineering into a highly efficient and reliable approach for gene assembly. RMDAP proposes a strategy for gene stacking and contains a wide range of flexible, modular vectors offering a series of functionally validated genetic elements to manipulate transgene overexpression or gene silencing involved in a metabolic pathway. In particular, the ability to construct a multigene marker-free vector is another attractive feature. The built-in flexibility of original vectors has greatly increased the expansibility and applicability of the system. A proof-ofprinciple experiment was confirmed by successfully transferring several heterologous genes into the plant genome. Conclusions/Significance: This platform is a ready-to-use toolbox for full exploitation of the potential for coordinate regulation of metabolic pathways and molecular breeding, and will eventually achieve the aim of what we call ‘‘one-sto