Ventriculoperitoneal (VP) shunt is the most commonly utilized shunting procedure because of the capacity of the peritoneum to resorb fluid. Initial and subsequent peritoneal catheter placements can ...be done with relative ease. They are associated with a variety of complications.
The total number of patients operated in the study period was 96. We studied 41 operated patients of VP shunt who had various shunt-related complications and analyzed the predisposing risk factors and spectrum of complications.
The mean age was 28 ± 32 months out of which 28 were males and 13 females. The etiology of hydrocephalus was aqueductal stenosis in 18, Arnold Chiari malformation in 10, Dandy-Walker malformation in 2, postmeningitis in 8 (pyogenic in 5 and tubercular in 3), postintraventricular hemorrhage in 2 patients and postencephalocele surgery in 1.
With this retrospective review of complications of VP shunts, age at initial shunt insertion and the interval between the age of initial shunt placement and onset of complications were the most important patient-related predictors of shunt failure. The different predominant etiological factors responsible for early and late shunt failure were infective and mechanical complications, respectively.
Analysis of the transcriptome of Borrelia burgdorferi, the causative agent of Lyme disease, during infection has proven difficult due to the low spirochete loads in the mammalian tissues. To overcome ...this challenge, we have developed an In Vivo Expression Technology (IVET) system for identification of B. burgdorferi genes expressed during an active murine infection. Spirochetes lacking linear plasmid (lp) 25 are non-infectious yet highly transformable. Mouse infection can be restored to these spirochetes by expression of the essential lp25-encoded pncA gene alone. Therefore, this IVET-based approach selects for in vivo-expressed promoters that drive expression of pncA resulting in the recovery of infectious spirochetes lacking lp25 following a three week infection in mice. Screening of approximately 15,000 clones in mice identified 289 unique in vivo-expressed DNA fragments from across all 22 replicons of the B. burgdorferi B31 genome. The in vivo-expressed candidate genes putatively encode proteins in various functional categories including antigenicity, metabolism, motility, nutrient transport and unknown functions. Candidate gene bbk46 on essential virulence plasmid lp36 was found to be highly induced in vivo and to be RpoS-independent. Immunocompetent mice inoculated with spirochetes lacking bbk46 seroconverted but no spirochetes were recovered from mouse tissues three weeks post inoculation. However, the bbk46 gene was not required for B. burgdorferi infection of immunodeficient mice. Therefore, through an initial IVET screen in B. burgdorferi we have identified a novel in vivo-induced virulence factor critical for the ability of the spirochete to evade the humoral immune response and persistently infect mice.
The conversion of nicotinamide to nicotinic acid by nicotinamidase enzymes is a critical step in maintaining NAD(+) homeostasis and contributes to numerous important biological processes in diverse ...organisms. In Borrelia burgdorferi, the nicotinamidase enzyme, PncA, is required for spirochaete survival throughout the infectious cycle. Mammals lack nicotinamidases and therefore PncA may serve as a therapeutic target for Lyme disease. Contrary to the in vivo importance of PncA, the current annotation for the pncA ORF suggests that the encoded protein may be inactive due to the absence of an N-terminal aspartic acid residue that is a conserved member of the catalytic triad of characterized PncA proteins. Herein, we have used genetic and biochemical strategies to determine the N-terminal sequence of B. burgdorferi PncA. Our data demonstrate that the PncA protein is 24 aa longer than the currently annotated sequence and that pncA translation is initiated from the rare, non-canonical initiation codon AUU. These findings are an important first step in understanding the catalytic function of this in vivo-essential protein.
Two phase treatment of Class III malocclusion Roopa Siddegowda; Kanhu Charan Sahoo; Sunny Jain
SRM Journal of Research in Dental Sciences,
10/2013, Letnik:
4, Številka:
4
Journal Article
Recenzirano
Odprti dostop
The developing skeletal Class III malocclusion is one of the most challenging problems confronting the practicing orthodontists. True Class III malocclusion is rare when compared with Class II and ...Class I and may develop in children as a result of inherent growth abnormality. Treatment should be carried out as early as possible with the aim to prevent it from becoming severe. The case was treated with biphasic therapy, i.e., orthopedic appliance followed by fixed orthodontic treatment. Facemask helps resolving the skeletal discrepancy.
The Lyme disease spirochete Borrelia burgdorferi is dependent on purine salvage from the host environment for survival. The genes bbb22 and bbb23 encode purine permeases that are essential for B. ...burgdorferi mouse infectivity. We now demonstrate the unique contributions of each of these genes to purine transport and murine infection. The affinities of spirochetes carrying bbb22 alone for hypoxanthine and adenine were similar to those of spirochetes carrying both genes. Spirochetes carrying bbb22 alone were able to achieve wild-type levels of adenine saturation but not hypoxanthine saturation, suggesting that maximal hypoxanthine uptake requires the presence of bbb23. Moreover, the purine transport activity conferred by bbb22 was dependent on an additional distal transcriptional start site located within the bbb23 open reading frame. The initial rates of uptake of hypoxanthine and adenine by spirochetes carrying bbb23 alone were below the level of detection. However, these spirochetes demonstrated a measurable increase in hypoxanthine uptake over a 30-min time course. Our findings indicate that bbb22-dependent adenine transport is essential for B. burgdorferi survival in mice. The bbb23 gene was dispensable for B. burgdorferi mouse infectivity, yet its presence was required along with that of bbb22 for B. burgdorferi to achieve maximal spirochete loads in infected mouse tissues. These data demonstrate that both genes, bbb22 and bbb23, are critical for B. burgdorferi to achieve wild-type infection of mice and that the differences in the capabilities of the two transporters may reflect distinct purine salvage needs that the spirochete encounters throughout its natural infectious cycle.
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