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Infectious Process (infectious + process)
Selected AbstractsAnti-adhesion therapy of bacterial diseases: prospects and problemsFEMS IMMUNOLOGY & MEDICAL MICROBIOLOGY, Issue 3 2003Itzhak Ofek Abstract The alarming increase in drug-resistant bacteria makes a search for novel means of fighting bacterial infections imperative. An attractive approach is the use of agents that interfere with the ability of the bacteria to adhere to tissues of the host, since such adhesion is one of the initial stages of the infectious process. The validity of this approach has been unequivocally demonstrated in experiments performed in a wide variety of animals, from mice to monkeys, and recently also in humans. Here we review various approaches to anti-adhesion therapy, including the use of receptor and adhesin analogs, dietary constituents, sublethal concentrations of antibiotics and adhesin-based vaccines. Because anti-adhesive agents are not bactericidal, the propagation and spread of resistant strains is much less likely to occur than as a result of exposure to bactericidal agents, such as antibiotics. Anti-adhesive drugs, once developed, may, therefore, serve as a new means to fight infectious diseases. [source] Cervical spondylodiscitis: A rare complication after phonatory prosthesis insertionHEAD & NECK: JOURNAL FOR THE SCIENCES & SPECIALTIES OF THE HEAD AND NECK, Issue 1 2006Andrea Bolzoni MD Abstract Background. Tracheoesophageal puncture has excellent voice rehabilitation after total laryngectomy. However, despite its easy insertion and use, severe complications have been reported. Methods. We report a case of cervical spondylodiscitis, occurring in a 67-year-old woman submitted to phonatory prosthesis insertion. After 1 month, she complained of severe cervicalgia associated with fever. Spondylodiscitis involving C6, C7, and the intervening vertebral disk with medullary compression was detected by means of imaging studies. Results. A right cervicotomy with drainage of necrotic tissue was performed, and a deepithelialized fasciocutaneous deltopectoral flap was interposed between the neopharynx-esophagus and the prevertebral fascia to protect the neurovascular axis. MR performed 1 month later showed a complete resolution of the infectious process. Conclusions. Severe neck pain after tracheoesophageal puncture should alert the physician about the possibility of a cervical spondylodiscitis. MR is the most useful imaging technique for preoperative and postoperative evaluation. When neurologic symptoms are detected, surgical exploration of the neck is mandatory. © 2005 Wiley Periodicals, Inc. Head Neck28: XXX,XXX, 2005 [source] Utility of Infectious Disease Coding Sheets for Surveillance in a State Medical Examiner's Office,JOURNAL OF FORENSIC SCIENCES, Issue 4 2008Ph.D., Sarah L. Lathrop D.V.M. Abstract:, Medical examiners are often first to recognize unusual occurrences of fatal infectious diseases. Recognition of these deaths allows public health officials to institute appropriate public health measures. Therefore, we developed a simple method of identifying and tracking infectious disease deaths in a statewide medical examiner's office. One-page infectious disease forms were completed for 1566/1949 autopsies (80%) performed at the New Mexico Office of the Medical Investigator in 2004. In 241 cases one infectious disease was identified at autopsy and 58 cases had two infectious diseases. Fourteen of the infectious-diseases caused deaths involved diseases that are notifiable conditions in New Mexico. Pneumonia was the most commonly reported infectious process (47 deaths) followed by sepsis (25 deaths). Tracking infectious disease deaths highlighted the importance of recognizing these deaths, although hand-written entries were unstandardized. Preferably, a tracking system would be built into electronic databases at medical examiner and coroner's offices, expediting the identification of these diseases and contact of public health agencies. [source] The RprY response regulator of Porphyromonas gingivalisMOLECULAR MICROBIOLOGY, Issue 4 2007Ana E. Duran-Pinedo Summary Porphyromonas gingivalis is a Gram-negative oral anaerobe associated with chronic adult periodontitis. Its ecological niche is the gingival crevice, where the organism adapts to the challenges of the infectious process such as host defence and bacterial products. Bacterial responses to environmental changes are partly regulated by two-component signal transduction systems. Several intact systems were annotated in the genome of P. gingivalis, as well as an orphan regulator encoding a homologue of RprY, a response regulator from Bacteroides fragilis. With the goal of defining the environmental cues that activate RprY in P. gingivalis, we used several strategies to identify its regulon. Results from gene expression and DNA,protein binding assays identified target genes that were either involved in transport functions or associated with oxidative stress, and indicated that RprY can act as an activator and a repressor. RprY positively activated the primary sodium pump, NADH : ubiquinone oxidoreductase (NQR), and RprY protein also interacted with the promoter regions of nqrA genes from B. fragilis and Vibrio cholerae. Given that gingival bleeding and infiltration of host defence cells are symptoms of periodontal infection, iron products released from blood and reactive oxygen species from polymorphonuclear leucocytes may be potential inducers of the RprY regulon. [source] Three temporal classes of gene expression during the Chlamydia trachomatis developmental cycleMOLECULAR MICROBIOLOGY, Issue 4 2000E. I. Shaw The obligate intracellular bacterium Chlamydia trachomatis has a unique developmental cycle that involves functionally and morphologically distinct cell types adapted for extracellular survival and intracellular multiplication. Infection is initiated by an environmentally resistant cell type called an elementary body (EB). Over the first several hours of infection, EBs differentiate into a larger replicative form, termed the reticulate body (RB). Late in the infectious process, RBs asynchronously begin to differentiate back to EBs, which accumulate within the lumen of the inclusion until released from the host cell for subsequent rounds of infection. In an effort to characterize temporal gene expression in relation to the chlamydial developmental cycle, we have used quantitative,competitive polymerase chain reaction (QC-PCR) and reverse transcription (RT)-PCR techniques. These analyses demonstrate that C. trachomatis double their DNA content every 2,3 h, with synthesis beginning between 2 and 4 h after infection. We determined the onset of transcription of specific temporal classes of developmentally expressed genes. RT-PCR analysis was performed on several genes encoding key enzymes or components of essential biochemical pathways and functions. This comparison encompassed approximately 8% of open reading frames on the C. trachomatis genome. In analysis of total RNA samples harvested at 2, 6, 12 and 20 h after infection, using conditions under which a single chlamydial transcript per infected cell is detected, three major temporal classes of gene expression were resolved. Initiation of transcription appears to occur in three temporal classes which we have operationally defined as: early, which are detected by 2 h after infection during the germination of EBs to RBs; mid-cycle, which appear between 6 and 12 h after infection and represent transcripts expressed during the growth and multiplication of RBs; or late, which appear between 12 and 20 h after infection and represent those genes transcribed during the terminal differentiation of RBs to EBs. Collectively, the data suggest that chlamydial early gene functions are weighted toward initiation of macromolecular synthesis and the establishment of their intracellular niche by modification of the inclusion membrane. Surprisingly, representative enzymes of intermediary metabolism and structural proteins do not appear to be transcribed until 10,12 h after infection; coinciding with the onset of observed binary fission of RBs. Late gene functions appear to be predominately those associated with the terminal differentiation of RBs back to EBs. [source] Disease-specific particles without prion protein in prion diseases , phenomenon or epiphenomenon?NEUROPATHOLOGY & APPLIED NEUROBIOLOGY, Issue 4 2007P. P. Liberski The search for the cause of transmissible spongiform encephalopathies (TSEs) has a long and tortuous history. In a recent paper, 25-nm virus-like particles were identified that were consistently observed in cell cultures infected with Creutzfeldt-Jakob disease (CJD) and scrapie; they are similar to, or even identical with, the virus-like tubulovesicular structures (TVS) found in experimental scrapie as early as in 1968, and subsequently in all naturally occurring and experimentally induced TSEs. These particles have been viewed with caution by the scientific community because of the unverified or uninterpretable record of virus-like structures reported over the years in TSEs. TVS are spherical or tubular particles of approximate diameter 25,37 nm. They are smaller than synaptic vesicles, but larger than many particulate structures of the central nervous system, such as glycogen granules. Their electron density is higher compared with synaptic vesicles, and in experimental murine scrapie, they form paracrystalline arrays. None of these observations distinguish between TVS as an entity critical to the infectious process, or as a highly specific ultrastructural epiphenomenon, but their consistent presence in all TSEs demands further research. [source] Regular Tracheostomy Tube Changes to Prevent Formation of Granulation TissueTHE LARYNGOSCOPE, Issue 1 2003Kathleen Yaremchuk MD Abstract Objectives/Hypothesis Tracheostomy is a commonly performed operative procedure that has been described since 2000 b.c. The early indications for tracheostomy were for upper airway obstruction, usually occurring in young people as a result of an infectious process. Recently, tracheostomies are more commonly performed in the critically ill patient to assist in long-term ventilatory support. Granulation tissue at the stoma and the trachea has been described as a late complication resulting in bleeding, drainage, and difficulty with maintaining mechanical ventilatory support. Study Design The present report is of an observational study of a newly implemented policy that required regular changing of tracheostomy tubes. Comparable groups of patients were compared before and after this procedural change to document complications. Data collection consisted of chart reviews of all admissions for 1 year before the policy change and the subsequent 2 years. Complication rates were compared using standard statistical techniques. Methods A policy change was instituted that required all tracheostomy tubes to be changed every 2 weeks in conjunction with a detailed evaluation of the tracheostomy stoma. Charts were reviewed the year before the change in policy and in the subsequent 2 years to determine the incidence of granulation tissue requiring operative intervention. Results The number of patients requiring surgical intervention secondary to granulation tissue showed a statistically significant decrease (P = .02). A review of policies and procedures from the six largest hospitals in southeastern Michigan had no recommendations for routine tracheostomy tube changes. Conclusions A policy requiring a routine change of tracheostomy tubes results in fewer complications from granulation tissue. Tracheostomy tube changes to prevent granulation tissue and its complications. [source] Postoperative surgical site infections in cardiac surgery ,an overview of preventive measuresAPMIS, Issue 9 2007BENGT GÅRDLUND Postoperative surgical site infections are a major cause of postoperative morbidity and mortality in cardiac surgery. A surgical site infection occurs when the contaminating pathogens overcome the host defense systems and an infectious process begins. Bacteria may enter the operating site either by direct contamination from the patient's skin or internal organs, through the hands and instruments of the surgical staff or by bacteria-carrying particles that float around in the operating theatre and may land in the wound. The ability to withstand the contaminating bacteria depends on both local and systemic host defense. Successful preventive strategies are multiple and must include: 1) Minimizing the bacterial contamination of the surgical site (skin preparation, operating room ventilation, scrubbing, double gloving, etc.), 2) Minimizing the consequences of virulent contaminating bacteria by antibiotic prophylaxis (adequate dose, sort, timing, duration), 3) Minimizing injury to local host defense (atraumatic surgery, no excessive electrocautery, meticulous hemostasis, etc.), and 4) Optimizing general host defense (nutrition, tobacco smoking, weight loss, etc.). Compliance with these preventive procedures must be enforced through regular reviews of performance. Non-compliance with hygiene routines is often due to ignorance and poor planning. Education of personnel in these issues is a continuous process. [source] Parasites in food webs: the ultimate missing linksECOLOGY LETTERS, Issue 6 2008Kevin D. Lafferty Abstract Parasitism is the most common consumer strategy among organisms, yet only recently has there been a call for the inclusion of infectious disease agents in food webs. The value of this effort hinges on whether parasites affect food-web properties. Increasing evidence suggests that parasites have the potential to uniquely alter food-web topology in terms of chain length, connectance and robustness. In addition, parasites might affect food-web stability, interaction strength and energy flow. Food-web structure also affects infectious disease dynamics because parasites depend on the ecological networks in which they live. Empirically, incorporating parasites into food webs is straightforward. We may start with existing food webs and add parasites as nodes, or we may try to build food webs around systems for which we already have a good understanding of infectious processes. In the future, perhaps researchers will add parasites while they construct food webs. Less clear is how food-web theory can accommodate parasites. This is a deep and central problem in theoretical biology and applied mathematics. For instance, is representing parasites with complex life cycles as a single node equivalent to representing other species with ontogenetic niche shifts as a single node? Can parasitism fit into fundamental frameworks such as the niche model? Can we integrate infectious disease models into the emerging field of dynamic food-web modelling? Future progress will benefit from interdisciplinary collaborations between ecologists and infectious disease biologists. [source] Balloon Cell Melanoma: Case ReportJOURNAL OF CUTANEOUS PATHOLOGY, Issue 1 2005Anna Yemelyanova Balloon cell melanoma (BCM) is a rare histological variant of amelanotic melanoma. The differential diagnosis of clear cell lesion includes BCM, renal cell carcinoma, clear cell sarcoma as well as a number of histiocytic and infectious processes. We report a case of BCM in a 33 year-old Indonesian man who presented with a non-tender, freely movable, non-pigmented left thigh nodule, which had been present for a year. On microscopic examination tumor consisted of a nodular infiltrate present within the dermis with superficial invasion of subcutaneous fat. Tumor cells formed nested aggregates were relatively bland in appearance and had abundant, clear cytoplasm, enlarged nuclei and prominent eosinophilic nucleoli. Rare mitotic figures were present within the deep portion of the neoplasm. No definitive nests were seen at the dermal epidermal junction or within the epidermis. Histochemical stains AFB, PAS/D, and GMS were negative. Immunoperoxidase studies were positive with antibodies to vimentin, S100, HMB45, CD68, and negative with cytokeratin, Factor XIIIA, and lysozyme. The diagnosis of BCMM was favored based on histological features, and immunoperoxidase staining pattern. We believe this case can provide additional information to help establish diagnostic criteria of this rare variant of melanoma. [source] Benign cysts in the central nervous system: Neuropathological observations of the cyst wallsNEUROPATHOLOGY, Issue 1 2004Asao Hirano A diverse variety of benign cysts exist in the CNS. Advances in diagnostic radiology have facilitated diagnoses and surgical intervention in many patients with CNS cysts. However, a fundamental understanding of the pathological features of these lesions is clinically vital. From an etiological point of view, the cysts can be divided into two groups. The first includes lesions that arise from within the CNS and may be static structures such as cavities arising from infarcts and other destructive processes while other lesions such as arachnoid cysts, ependymal cysts, cystic hemangioblastoma, cystic cerebellar astrocytoma and infectious processes, are progressive. The second group of cysts arise from the intrusion of non-nervous system tissue into the neuroaxis and are usually midline. They are frequently expanding congenital lesions although some become symptomatic only in adults. Examples include teratomas, dermoid cysts, epidermoid cysts, craniopharyngiomas, Rathke's cleft cysts, and other epithelial cysts presumably derived from the upper respiratory or intestinal tract. Chick embryos exposed to lead have been used as a model of cyst formation. [source] | |||||||||||||