Monoclonal antibodies against the iron regulated outer membrane Proteins of Acinetobacter baumanniiare bactericidal

Background

Iron is an important nutrient required by all forms of life.In the case of human hosts,the free iron availability is 10^-18M,which is far less than what is needed for the survival of the invading bacterial pathogen.To survive in such conditions, bacteria express new proteins in their outer membrane and also secrete iron chelators called siderophores.

Results/ Discussion

Acinetobacter baumanniiATCC 19606, a nosocomial pathogen which grows under iron restricted conditions, expresses four new outer membrane proteins,with molecular weight ranging from 77 kDa to 88 kDa, that are called Iron Regulated Outer Membrane Proteins (IROMPs). We studied the functional and immunological properties of IROMPs expressed by A.baumaniiATCC 19606.The bands corresponding to IROMPs were eluted from SDS-PAGE and were used to immunize BALB/c mice for the production of monoclonal antibodies. Hybridomas secreting specific antibodies against these IROMPs were selected after screening by ELISA and their reactivity was confirmed by Western Blot. The antibodies then generated belonged to IgM isotype and showed bactericidical and opsonising activities against A.baumanii in vitro.These antibodies also blocked siderophore mediated iron uptake via IROMPs in bacteria.

Conclusion

This proves that iron uptake via IROMPs,which is mediated through siderophores,may have an important role in the survival of A.baumaniiinside the host,and helps establishing the infection.     

Functional characterization of LIKE HETEROCHROMATIN PROTEIN 1 in the moss Physcomitrella patens: its conserved protein interactions in land plants

In flowering plants, LIKE HETEROCHROMATIN PROTEIN 1 (LHP1)/TERMINAL FLOWER 2 (TFL2) is known to interact with polycomb group (PcG) and non‐PcG proteins and control developmental programs. LHP1/TFL2 is an ancient protein and has been characterized in the early‐divergent plant Physcomitrella patens. However, interacting partners of PpLHP1 other than the chromomethylase PpCMT have not been identified to date. Also, while functional polycomb repressive complex 2 (PRC2) is known to exist in P. patens, there is no experimental evidence to support the existence of PRC1‐like complexes in these mosses. In this study, using protein?protein interaction methods, transient expression assays and targeted gene knockout strategy, we report the conserved properties of LHP1/TFL2 using the Physcomitrella system. We show that a PRC1‐like core complex comprising of PpLHP1 and the putative PRC1 Really Interesting New Gene (RING)‐finger proteins can form in vivo. Also, the interaction between PpRING and the PRC2 subunit PpCLF further sheds light on the possible existence of combinatorial interactions between the Polycomb Repressive Complex (PRC) in early land plants. Based on the interaction between PpLHP1 and putative hnRNP PpLIF2‐like in planta, we propose that the link between PpLHP1 regulation and RNA metabolic processes was established early in plants. The conserved subnuclear distribution pattern of PpLHP1 in moss protonema further provides insight into the manner in which LHP1/TFL2 are sequestered in the nucleoplasm in discrete foci. The PpLHP1 loss‐of‐function plants generated in this study share some of the pleiotropic defects with multiple aberrations reported in lhp1/tfl2. Taken together, this work documents an active role for PpLHP1 in epigenetic regulatory network in P. patens.     

A genomewide admixture map for Latino populations

Admixture mapping is an economical and powerful approach for localizing disease genes in populations of recently mixed ancestry and has proven successful in African Americans. The method holds equal promise for Latinos, who typically inherit a mix of European, Native American, and African ancestry. However, admixture mapping in Latinos has not been practical because of the lack of a map of ancestry-informative markers validated in Native American and other populations. To address this, we screened multiple databases, containing millions of markers, to identify 4,186 markers that were putatively informative for determining the ancestry of chromosomal segments in Latino populations. We experimentally validated each of these markers in at least 232 new Latino, European, Native American, and African samples, and we selected a subset of 1,649 markers to form an admixture map. An advantage of our strategy is that we focused our map on markers distinguishing Native American from other ancestries and restricted it to markers with very similar frequencies in Europeans and Africans, which decreased the number of markers needed and minimized the possibility of false disease associations. We evaluated the effectiveness of our map for localizing disease genes in four Latino populations from both North and South America.     

Heterologous Expression of Two Jatropha Aquaporins Imparts Drought and Salt Tolerance and Improves Seed Viability in Transgenic Arabidopsis thaliana

Drought and high salinity are environmental conditions that cause adverse effects on the growth and productivity of crops. Aquaporins are small integral membrane proteins that belong to the family of the major intrinsic proteins (MIPs), with members in animals, plants and microbes, where they facilitate the transport of water and/or small neutral solutes thereby affecting water balance. In this study we characterized two aquaporin genes namely, plasma membrane intrinsic protein (PIP2;7) and tonoplast intrinsic protein TIP1;3 from Jatropha curcas that are localised to the plasma membrane and vacuole respectively. Transgenic Arabidopsis thaliana lines over-expressing JcPIP2;7 and JcTIP1;3 under a constitutive promoter show improved germination under high salt and mannitol compared to control seeds. These transgenic plants also show increased root length under abiotic stress conditions compared to wild type Col-0 plants. Transgenic lines exposed to drought conditions by withholding water for 20 days, were able to withstand water stress and attained normal growth after re-watering unlike control plants which could not survive. Transgenic lines also had better seed yield than control under salt stress. Importantly, seed viability of transgenic plants grown under high salt concentration was 35%-45% compared to less than 5% for control seeds obtained from plants growing under salt stress. The effect of JcPIP2;7 and JcTIP1;3 on improving germination and seed viability in drought and salinity make these important candidates for genetic manipulation of plants for growth in saline soils.     

Conservative Management of Urinary Incontinence in Women

Urinary incontinence in women has a high prevalence and causes significant morbidity. Given that urinary incontinence is not generally a progressive disease, conservative therapies play an integral part in the management of these patients. We conducted a nonsystematic review of the literature to identify high-quality studies that evaluated the different components of conservative management of stress urinary incontinence, including behavioral therapy, bladder training, pelvic floor muscle training, lifestyle changes, mechanical devices, vaginal cones, and electrical stimulation. Urinary incontinence can have a severe impact on our healthcare system and patients’ quality of life. There are currently a wide variety of treatment options for these patients, ranging from conservative treatment to surgical treatment. Although further research is required in the area of conservative therapies, nonsurgical treatments are effective and are preferred by some patients.Key words: Urinary incontinence, Women, Conservative managementUrinary incontinence (UI) is a significant cause of decrease in quality of life, especially among women.¹ The prevalence of UI in women is estimated to range from 13% to 46%,^2,3 and studies have shown that incontinence increases with age.⁴ In addition to the significant social impact that UI has on a woman’s quality of life, this condition has a significant financial burden on individual and national healthcare dollars. It has been estimated that the total annual direct and indirect cost for UI in the United States alone is $19.5 billion.⁵UI is defined according to patients’ symptoms. Although definitions vary in the literature, the International Continence Society defines three major subtypes of UI: (1) stress urinary incontinence (SUI) is the complaint of involuntary leakage on effort or exertion, or on sneezing or coughing; (2) urgency urinary incontinence (UUI) is the complaint of involuntary leakage accompanied by or immediately preceded by urgency; and (3) mixed urinary incontinence (MUI) is the complaint of involuntary leakage associated with urgency and also with exertion, effort, sneezing, or coughing.^6,7Although there is a plethora of treatment options, conservative management is the first-line option for most patients with UI. The rationale for conservative treatment is that UI is not necessarily a progressive disease, and that conservative therapies can be effective, well tolerated, and safe. Furthermore, a moderate delay in surgical therapy does not make treatment more difficult or less effective. One of the recommendations of the 1992 Agency for Health Care Policy and Research guideline states that “surgery, except in very specific cases, should be considered only after behavioral and pharmacologic interventions have been tried.”⁸ Similarly, the European Association of Urology guidelines advocate a stepwise approach regarding management of UI, which begins with addressing underlying medical or cognitive issues, progressing to lifestyle modifications, behavioral therapy, and mechanical devices.⁹ In addition, conservative therapies are frequently preferred by many patients. Taking into account the patient’s goals and preferences, it is appropriate to recommend conservative management as an initial approach.     

Synthesis and antibacterial activity of novel oxazolidinones with methylene oxygen- and methylene sulfur-linked substituents at C5-position

Novel oxazolidinone derivatives of the lead compound RBx 8700, containing methylene oxygen- and methylene sulfur-linked substituents at the C5-position, were synthesized. Antibacterial screening of these compounds against a panel of resistant and susceptible Gram-positive and fastidious Gram-negative bacteria gave compounds 2 and 4 as new antibacterial agents.