Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0036690 (sepsis)
 59,461 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

OpcA is an integral outer membrane protein from Neisseria meningitidis, the causative agent of meningococcal meningitis and septicemia. It mediates the adhesion of N. meningitidis to epithelial and endothelial cells by binding to vitronectin and proteoglycan cell-surface receptors. Here, we report the determination of the crystal structure of OpcA to 2.0 A resolution. OpcA adopts a 10-stranded beta-barrel structure with extensive loop regions that protrude above the predicted surface of the membrane. The second external loop adopts an unusual conformation, traversing the axis of the beta-barrel and apparently blocking formation of a pore through the membrane. Loops 2, 3, 4, and 5 associate to form one side of a crevice in the external surface of the structure, the other side being formed by loop 1. The crevice is lined by positively charged residues and would form an ideal binding site for proteoglycan polysaccharide. The structure, therefore, suggests a model for how adhesion of this important human pathogen to proteoglycan is mediated at the molecular level.
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PMID:Crystal structure of the OpcA integral membrane adhesin from Neisseria meningitidis. 1189 40

Neisseria meningitidis is the cause of septicemia and meningococcal meningitis. During the course of infection, N. meningitidis encounters multiple environments within its host, which makes rapid adaptation to environmental changes a crucial factor for neisserial pathogenicity. Employing oligonucleotide-based DNA microarrays, we analyzed the transcriptome of N. meningitidis during two key steps of meningococcal infection, i.e., the interaction with epithelial cells (HeLa cells) and endothelial cells (human brain microvascular endothelial cells). Seventy-two genes were differentially regulated after contact with epithelial cells, and 48 genes were differentially regulated after contact with endothelial cells, including a considerable proportion of well-known virulence genes. While a considerable number of genes were in concordance between bacteria adherent to both cell types, we identified several open reading frames that were differentially regulated in only one system. The data obtained with this novel approach may provide insight into the pathogenicity mechanisms of N. meningitidis and could demonstrate the importance of gene regulation on the transcriptional level during different stages of meningococcal infection.
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PMID:Transcriptome analysis of Neisseria meningitidis during infection. 1248 52

Meningococcal septicaemia has high mortality, especially when the diagnosis is delayed or missed. Early recognition is not always straightforward, as classic clinical features may be absent or overlooked at initial presentation. Septicaemia without focal infection accounts for 15%-20% of cases of meningococcal disease and is the most worrisome manifestation in terms of diagnosis and outcome; in contrast, meningococcal meningitis is usually straightforward to diagnose, with a relatively good prognosis. Useful early clinical clues to meningococcaemia include: - a haemorrhagic (petechial or purpuric) rash; - blanching macular or maculopapular rash that appears in first 24 hours of illness; - true rigors; - severe pain in extremities, neck or back; vomiting, especially in association with headache or abdominal pain; rapid evolution of the illness; - concern of parents, relatives or friends; - patient age (highest incidence at age 3-12 months, followed by 1-4 and then 15-19 years); and - contact with a patient with meningococcal disease. In addition to specific clues, clinicians should look at the whole pattern of the illness. Timely clinical review is essential if there is doubt about the diagnosis. In any acutely febrile patient, it is prudent to ask "Why is this patient seeking help now?", then "Could this patient have meningococcaemia?".
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PMID:Early clinical clues to meningococcaemia. 1255 87

A 3-year-old girl with phenotypic and cytogenetic manifestations of the ICF syndrome and DNA hypomethylation but without DNMT3B gene mutation is described. At age 3 months, she had an apneic spell that left her with spastic paraplegia and severe mental retardation. At age 8 months, she suffered meningococcal meningitis and sepsis. When seen by us at age 3 years with virilization, she had a cleft plate, macroglossia, and an atrial septal defect. An adenoma was surgically removed from the right adrenal cortex. Her serum immunoglobulin levels were normal except IgA at the low normal border. Her lymphocytes showed paracentromeric stretching of chromosomes 1 and 16 in 7% of metaphases, and multiradial figures involving these chromosomes in 1% of cells. Hypomethylation of classical satellite 2 DNA was observed with BstBI digestion, but in a lesser degree than those in the individuals with proven DNMT3B mutations. No mutation was found in the coding and promoter regions of the gene. Several alternative interpretations were considered to explain the low frequencies of chromosomal instabilities and the lower degree of DNA hypomethylation, and undetected DNA3B mutations. A mutation may be present in the gene but undetected, present in other DNA methyltransferases (DNMT) genes or in a DNMT-associated protein gene.
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PMID:ICF syndrome in a girl with DNA hypomethylation but without detectable DNMT3B mutation. 1532 30

Severe infections caused by Neisseria meningitidis, clinically appearing as meningitis or sepsis, are constantly noted in developed countries, including Poland. Because of rapid clinical course and mortality rate they continue to pose a serious clinical problem. Most cases are sporadic ones, caused by the contact with a healthy carrier of N. meningitidis. Familial and group outbreaks are rare, being responsible for about 1% of cases. However, in family members of patients with meningococcal infection the risk of developing the disease during the following week is about one hundred times higher than in the general population and they should receive an antibiotic prophylaxis. We describe a familial outbreak of meningococcal meningitis with typical clinical features, which appeared in two members of a family during the same day, with a case of acute pharyngitis most likely of the same etiology in the third person, a child. In that instance, practically simultaneous appearance of consecutive cases gave no time for prophylaxis. However, suspicion of meningococcal disease in the first patient contributed to the prompt hospitalization and diagnostics and proper treatment in the two following cases.
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PMID:[Meningococcal meningitis--familial outbreak]. 1575 42

Purulent fluid collections, including brain abscess and subdural empyema, are exceedingly rare in association with meningococcal meningitis. We present a 5-month-old infant with meningococcal meningitis and sepsis complicated by an intracerebral abscess.
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PMID:Cerebral abscess associated with meningococcal meningitis. 1687 83

Microbiological tests for diagnosis of acute meningococcal disease are important for the clinical management of patients with this often-fatal illness, but cultures are frequently negative after antibiotics have been administered. Retrospective studies suggest that examination of skin biopsies may aid a rapid diagnosis and that cultures of skin biopsies are often positive even after antimicrobial treatment has commenced. This prospective controlled study aimed to assess the diagnostic value of skin biopsy compared with investigations of blood and cerebrospinal fluid (CSF) in patients with skin lesions and presumed meningococcal disease. A total of 43 patients, 31 with suspected acute meningococcal infection and 12 controls, were included. All skin biopsies were investigated by Gram stain and routine microbiological culture. In 25 patients, meningococcal infection was diagnosed microbiologically. The clinical diagnosis was meningococcal meningitis in 8 patients, meningococcal sepsis in 11 patients, and a combination of both in 6 patients. The sensitivity of cultures of blood, CSF, and skin biopsies was 56%, 50%, and 36%, respectively. When culture and Gram stain were combined, positive results were obtained in 56%, 64%, and 56%, respectively. There was no correlation between the diagnostic yield of skin biopsies and previous antibiotic treatment. In 14 patients, the diagnosis was based exclusively on one positive sample: CSF in 7 (28%) patients, blood in 4 (16%) patients, and skin biopsy in 3 (12%) patients. The sensitivity of skin biopsies was highest in patients with the least extensive skin lesions. Specificity was 100%. Microbiological investigation of skin biopsies increased the diagnostic yield and could be considered a component of the routine diagnostic work-up in patients with suspected meningococcal infection, even after the initiation of antimicrobial treatment.
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PMID:Prospective controlled study of the diagnostic value of skin biopsy in patients with presumed meningococcal disease. 1696 10

Invasive meningococcal infections show a broad clinical picture including sepsis and meningitis. Here we report on a case of sepsis and a case of meningitis, two clinical manifestations of meningococcal infections with striking differences in the clinical presentation and outcome. Meningococcal sepsis is characterized by a systemic release of endotoxins, that triggers an intense cytokine response of the host that can lead to shock and multi organ failure and death within hours. Meningococcal meningitis occurs when bacteria breach into the subarachnoidal and ventricular space during bacteremia and mortality is much lower that in sepsis. Thus meningitis may be seen as a consequence of lower pathogenicity and/or more efficient host control of the meningococci compared to sepsis.
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PMID:[Invasive meningococcal infections: two cases that demonstrate the broad spectrum in clinical manifestation and outcome]. 1711 53

In order to asses the clinical forms of meningococcal disease, we reviewed 201 cases diagnosed as meningococcal disease in the University Hospital of the Fluminense Federal University in Rio de Janeiro, 185 of which met the inclusion criteria. Clinical and laboratorial characterization allowed for grouping of the cases as follows: meningococcal meningitis, 18%; meningitis with septicemia, 62%; and septicemia, 20%. Available epidemiological data did not differentiate clinical forms. The following were significantly greater in meningococcal meningitis: duration of clinical history; frequency of neurological manifestations; positive bacterioscopy; culture and latex test in cerebrospinal fluid. The following were significantly predominant in septicemia: shock; fatal outcome and higher partial thromboplastin time. Septicemia and meningitis with septicemia were differentiated from meningococcal meningitis in the following: duration of clinical history; occurrence of focal neurological signs; disseminated intravascular coagulation; and arthritis. Clinical and laboratory data lead us to admit meningococcal meningitis as a localized form of Meningococcal disease, and meningitis with septicemia and septicemia as variations in severity of the systemic form of the disease.
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PMID:[Meningococcal disease: comparison between clinical forms]. 1765 66

OpcA from Neisseria meningitidis, the causative agent of meningococcal meningitis and septicemia, is an integral outer membrane protein that facilitates meningococcal adhesion through binding the proteoglycan receptors of susceptible cells. Two structures of OpcA have been determined by x-ray diffraction to 2 A resolution, revealing dramatically different conformations in the extracellular loops--the protein domain implicated in proteoglycan binding. In the first structure, a positively charged crevice formed by loops 1 and 2 was identified as the site for binding proteoglycans, whereas in the second structure the crevice was not evident as loops 1 and 2 adopted different conformations. To reconcile these results, molecular-dynamics simulations were carried out on both structures embedded in a solvated lipid bilayer membrane. Free of crystal contacts and crystallization agents, the loops were observed to undergo large structural transformations, suggesting that the conformation of the loops in either x-ray structure is affected by crystallization. Subsequent simulations of both structures in their crystal lattices confirmed this conclusion. Based on our molecular-dynamics trajectories, we propose a model for OpcA that combines stable structural features of the available x-ray structures. In this model, all five extracellular loops of OpcA have stable secondary structures. The loops form a funnel that leads to the base of the beta-barrel and that includes Tyr-169 on its exposed surface, which has been implicated in proteoglycan binding.
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PMID:Structure refinement of the OpcA adhesin using molecular dynamics. 1793 21


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