bluuebunny/crossref_metadata_2025_split huggingface dataset:
Use of water ‘softening and conditioning systems’ significantly increases the risk of periodontitis: smoking considerations
Authors: Wood Nelson , Johnson Roger B. 
Published: October 2004

Background:  The role of water in the etiology of periodontal disease is poorly understood.Objectives:  The objective of this study was to examine the association amongst water softness, risk for periodontitis, and smoking status.Methods:  We examined the association between use of water ‘softening and conditioning systems’ and the risk for periodontal disease in smokers and non‐smokers, using adult participants (18+ years), from the third National Health and Nutrition Examination Survey (NHANES III) data. Zero to 33 per cent (0–33%) of sites with periodontal attachment loss ≥ 3 mm was considered a healthy periodontium, and > 33% of sites with periodontal attachment loss ≥ 3 mm was defined as periodontitis. Soft water users were divided into ‘yes’ or ‘no’ using the question, ‘Does your home have a “softening or conditioning system?”.’ Smoking subjects were divided into groups as follows: current smokers (had smoked ≥ 100 cigarettes in their lifetime and currently smoked), former smokers (had smoked ≥ 100 cigarettes in their lifetime, not currently smoking), or never smokers (had not smoked ≥ 100 cigarettes in their lifetime). Data was analyzed by univariate analyses using SPSS®. The 5% level of statistical significance was adopted throughout.Results:  Subjects that answered the question ‘yes’ to soft water use had a significantly higher risk of periodontitis (p < 0.05), adjusting for confounders. When mineral intake from foods was added to the model, the significance of periodontitis risk remained the same for the non‐smoking, soft water‐using subjects, whereas for the smoking, soft water‐using subjects the risk for periodontitis increased significantly (p < 0.05) in most cases.Conclusions:  Thus, use of water ‘softening and conditioning systems’ significantly increased the risk for periodontitis, and smoking increased this risk.
Mycoplasma pneumoniaeand Its Role as a Human Pathogen
Authors: Waites Ken B. , Talkington Deborah F. 
Published: October 2004

SUMMARYMycoplasma pneumoniaeis a unique bacterium that does not always receive the attention it merits considering the number of illnesses it causes and the degree of morbidity associated with it in both children and adults. Serious infections requiring hospitalization, while rare, occur in both adults and children and may involve multiple organ systems. The severity of disease appears to be related to the degree to which the host immune response reacts to the infection. Extrapulmonary complications involving all of the major organ systems can occur in association withM. pneumoniaeinfection as a result of direct invasion and/or autoimmune response. The extrapulmonary manifestations are sometimes of greater severity and clinical importance than the primary respiratory infection. Evidence for this organism's contributory role in chronic lung conditions such as asthma is accumulating. Effective management ofM. pneumoniaeinfections can usually be achieved with macrolides, tetracyclines, or fluoroquinolones. As more is learned about the pathogenesis and immune response elicited byM. pneumoniae, improvement in methods for diagnosis and prevention of disease due to this organism may occur.
Impact of Malaria during Pregnancy on Low Birth Weight in Sub-Saharan Africa
Authors: Guyatt Helen L. , Snow Robert W. 
Published: October 2004

SUMMARY
Malaria during pregnancy can result in low birth weight (LBW), an important risk factor for infant mortality. This article reviews the pathological effects of malaria during pregnancy and the implications for the newborn's development and survival. Empirical data from throughout Africa on associations between placental malaria and birth weight outcome, birth weight outcome and infant mortality, and the rates of LBW in areas with various levels of malaria transmission are evaluated to assess the increased risks of LBW and infant mortality associated with malaria. It is estimated that in areas where malaria is endemic, around 19% of infant LBWs are due to malaria and 6% of infant deaths are due to LBW caused by malaria. These estimates imply that around 100,000 infant deaths each year could be due to LBW caused by malaria during pregnancy in areas of malaria endemicity in Africa.
Prevention of Infection Due toPneumocystisspp. in Human Immunodeficiency Virus-Negative Immunocompromised Patients
Authors: Rodriguez Martin , Fishman Jay A. 
Published: October 2004

SUMMARYPneumocystisinfection in humans was originally described in 1942. The organism was initially thought to be a protozoan, but more recent data suggest that it is more closely related to the fungi. Patients with cellular immune deficiencies are at risk for the development of symptomaticPneumocystisinfection. Populations at risk also include patients with hematologic and nonhematologic malignancies, hematopoietic stem cell transplant recipients, solid-organ recipients, and patients receiving immunosuppressive therapies for connective tissue disorders and vasculitides. Trimethoprim-sulfamethoxazole is the agent of choice for prophylaxis againstPneumocystisunless a clear contraindication is identified. Other options include pentamidine, dapsone, dapsone-pyrimethamine, and atovaquone. The risk for PCP varies based on individual immune defects, regional differences, and immunosuppressive regimens. Prophylactic strategies must be linked to an ongoing assessment of the patient's risk for disease.
Coccidioidomycosis: Host Response and Vaccine Development
Authors: Cox Rebecca A. , Magee D. Mitchell 
Published: October 2004

SUMMARYCoccidioidomycosis is caused by the dimorphic fungi in the genusCoccidioides. These fungi live as mycelia in the soil of desert areas of the American Southwest, and when the infectious spores, the arthroconidia, are inhaled, they convert into the parasitic spherule/endospore phase. Most infections are mild, but these organisms are frank pathogens and can cause severe lethal disease in fully immunocompetent individuals. While there is increased risk of disseminated disease in certain racial groups and immunocompromised persons, the fact that there are hosts who contain the initial infection and exhibit long-term immunity to reinfection supports the hypothesis that a vaccine against these pathogens is feasible. Multiple studies have shown that protective immunity against primary disease is associated with T-helper 1 (Th-1)-associated immune responses. The single best vaccine in animal models, formalin-killed spherules (FKS), was tested in a human trial but was not found to be significantly protective. This result has prompted studies to better define immunodominantCoccidioidesantigen with the thought that a subunit vaccine would be protective. These efforts have defined multiple candidates, but the single best individual immunogen is the protein termed antigen 2/proline-rich antigen (Ag2/PRA). Studies in multiple laboratories have shown that Ag2/PRA as both protein and genetic vaccines provides significant protection against mice challenged systemically withCoccidioides. Unfortunately, compared to the FKS vaccine, it is significantly less protective as measured by both assays of reduction in fungal CFU and assays of survival. The capacity of Ag2/PRA to induce only partial protection was emphasized when animals were challenged intranasally. Thus, there is a need to define new candidates to create a multivalent vaccine to increase the effectiveness of Ag2/PRA. Efforts of genomic screening using expression library immunization or bioinformatic approaches to identify new candidates have revealed at least two new protective proteins, expression library immunization antigen 1 (ELI-Ag1) and a β-1,3-glucanosyltransferase (GEL-1). In addition, previously discovered antigens such asCoccidioides-specific antigen (CSA) should be evaluated in assays of protection. While studies have yet to be completed with combinations of the current candidates, the hypothesis is that with increased numbers of candidates in a multivalent vaccine, there will be increased protection. As the genome sequences of the twoCoccidioidesstrains which are under way are completed and annotated, the effort to find new candidates can increase to provide a complete genomic scan for immunodominant proteins. Thus, much progress has been made in the discovery of subunit vaccine candidates againstCoccidioidesand there are several candidates showing modest levels of protection, but for complete protection against pulmonary challenge we need to continue the search for additional candidates.
Impact of 16S rRNA Gene Sequence Analysis for Identification of Bacteria on Clinical Microbiology and Infectious Diseases
Authors: Clarridge Jill E. 
Published: October 2004

SUMMARY
The traditional identification of bacteria on the basis of phenotypic characteristics is generally not as accurate as identification based on genotypic methods. Comparison of the bacterial 16S rRNA gene sequence has emerged as a preferred genetic technique. 16S rRNA gene sequence analysis can better identify poorly described, rarely isolated, or phenotypically aberrant strains, can be routinely used for identification of mycobacteria, and can lead to the recognition of novel pathogens and noncultured bacteria. Problems remain in that the sequences in some databases are not accurate, there is no consensus quantitative definition of genus or species based on 16S rRNA gene sequence data, the proliferation of species names based on minimal genetic and phenotypic differences raises communication difficulties, and microheterogeneity in 16S rRNA gene sequence within a species is common. Despite its accuracy, 16S rRNA gene sequence analysis lacks widespread use beyond the large and reference laboratories because of technical and cost considerations. Thus, a future challenge is to translate information from 16S rRNA gene sequencing into convenient biochemical testing schemes, making the accuracy of the genotypic identification available to the smaller and routine clinical microbiology laboratories.
Epidemiologic Background of Hand Hygiene and Evaluation of the Most Important Agents for Scrubs and Rubs
Authors: Kampf Günter , Kramer Axel 
Published: October 2004

SUMMARYThe etiology of nosocomial infections, the frequency of contaminated hands with the different nosocomial pathogens, and the role of health care workers' hands during outbreaks suggest that a hand hygiene preparation should at least have activity against bacteria, yeasts, and coated viruses. The importance of efficacy in choosing the right hand hygiene product is reflected in the new Centers for Disease Control and Prevention guideline on hand hygiene (J. M. Boyce and D. Pittet, Morb. Mortal. Wkly. Rep.51:1-45, 2002). The best antimicrobial efficacy can be achieved with ethanol (60 to 85%), isopropanol (60 to 80%), and n-propanol (60 to 80%). The activity is broad and immediate. Ethanol at high concentrations (e.g., 95%) is the most effective treatment against naked viruses, whereas n-propanol seems to be more effective against the resident bacterial flora. The combination of alcohols may have a synergistic effect. The antimicrobial efficacy of chlorhexidine (2 to 4%) and triclosan (1 to 2%) is both lower and slower. Additionally, both agents have a risk of bacterial resistance, which is higher for chlorhexidine than triclosan. Their activity is often supported by the mechanical removal of pathogens during hand washing. Taking the antimicrobial efficacy and the mechanical removal together, they are still less effective than the alcohols. Plain soap and water has the lowest efficacy of all. In the new Centers for Disease Control and Prevention guideline, promotion of alcohol-based hand rubs containing various emollients instead of irritating soaps and detergents is one strategy to reduce skin damage, dryness, and irritation. Irritant contact dermatitis is highest with preparations containing 4% chlorhexidine gluconate, less frequent with nonantimicrobial soaps and preparations containing lower concentrations of chlorhexidine gluconate, and lowest with well-formulated alcohol-based hand rubs containing emollients and other skin conditioners. Too few published data from comparative trials are available to reliably rank triclosan. Personnel should be reminded that it is neither necessary nor recommended to routinely wash hands after each application of an alcohol-based hand rub. Long-lasting improvement of compliance with hand hygiene protocols can be successful if an effective and accessible alcohol-based hand rub with a proven dermal tolerance and an excellent user acceptability is supplied, accompanied by education of health care workers and promotion of the use of the product.
Molecular Methods for Diagnosis of Viral Encephalitis
Authors: DeBiasi Roberta L. , Tyler Kenneth L. 
Published: October 2004

SUMMARYHundreds of viruses cause central nervous system (CNS) disease, including meningoencephalitis and postinfectious encephalomyelitis, in humans. The cerebrospinal fluid (CSF) is abnormal in >90% of cases; however, routine CSF studies only rarely lead to identification of a specific etiologic agent. Diagnosis of viral infections of the CNS has been revolutionized by the advent of new molecular diagnostic technologies to amplify viral nucleic acid from CSF, including PCR, nucleic acid sequence-based amplification, and branched-DNA assay. PCR is ideally suited for identifying fastidious organisms that may be difficult or impossible to culture and has been widely applied for detection of both DNA and RNA viruses in CSF. The technique can be performed rapidly and inexpensively and has become an integral component of diagnostic medical practice in the United States and other developed countries. In addition to its use for identification of etiologic agents of CNS disease in the clinical setting, PCR has also been used to quantitate viral load and monitor duration and adequacy of antiviral drug therapy. PCR has also been applied in the research setting to help discriminate active versus postinfectious immune-mediate disease, identify determinants of drug resistance, and investigate the etiology of neurologic disease of uncertain cause. This review discusses general principles of PCR and reverse transcription-PCR, including qualitative, quantitative, and multiplex techniques, with comment on issues of sensitivity, specificity, and positive and negative predictive values. The application of molecular diagnostic methods for diagnosis of specific infectious entities is reviewed in detail, including viruses for which PCR is of proven efficacy and is widely available, viruses for which PCR is less widely available or for which PCR has unproven sensitivity and specificity, and nonviral entities which can mimic viral CNS disease.
Antibody Therapy in the Management of Shiga Toxin-Induced Hemolytic Uremic Syndrome
Authors: Tzipori Saul , Sheoran Abhineet , Akiyoshi Donna , Donohue-Rolfe Arthur , Trachtman Howard 
Published: October 2004

SUMMARYHemolytic uremic syndrome (HUS) is a disease that can lead to acute renal failure and often to other serious sequelae, including death. The majority of cases are attributed to infections withEscherichia coli, serotype O157:H7 strains in particular, which cause bloody diarrhea and liberate one or two toxins known as Shiga toxins 1 and 2. These toxins are thought to directly be responsible for the manifestations of HUS. Currently, supportive nonspecific treatment is the only available option for the management of individuals presenting with HUS. The benefit of antimicrobial therapy remains uncertain because of several reports which claim that such intervention can in fact exacerbate the syndrome. There have been only a few specific therapies directed against neutralizing the activities of these toxins, but none so far has been shown to be effective. This article reviews the literature on the mechanism of action of these toxins and the clinical manifestations and current management and treatment of HUS. The major focus of the article, however, is the development and rationale for using neutralizing human antibodies to combat this toxin-induced disease. Several groups are currently pursuing this approach with either humanized, chimeric, or human antitoxin antibodies produced in transgenic mice. They are at different phases of development, ranging from preclinical evaluation to human clinical trials. The information available from preclinical studies indicates that neutralizing specific antibodies directed against the A subunit of the toxin can be highly protective. Such antibodies, even when administered well after exposure to bacterial infection and onset of diarrhea, can prevent the occurrence of systemic complications.
Role of Microglia in Central Nervous System Infections
Authors: Rock R. Bryan , Gekker Genya , Hu Shuxian , Sheng Wen S. , Cheeran Maxim , Lokensgard James R. , Peterson Phillip K. 
Published: October 2004

SUMMARYThe nature of microglia fascinated many prominent researchers in the 19th and early 20th centuries, and in a classic treatise in 1932, Pio del Rio-Hortega formulated a number of concepts regarding the function of these resident macrophages of the brain parenchyma that remain relevant to this day. However, a renaissance of interest in microglia occurred toward the end of the 20th century, fueled by the recognition of their role in neuropathogenesis of infectious agents, such as human immunodeficiency virus type 1, and by what appears to be their participation in other neurodegenerative and neuroinflammatory disorders. During the same period, insights into the physiological and pathological properties of microglia were gained from in vivo and in vitro studies of neurotropic viruses, bacteria, fungi, parasites, and prions, which are reviewed in this article. New concepts that have emerged from these studies include the importance of cytokines and chemokines produced by activated microglia in neurodegenerative and neuroprotective processes and the elegant but astonishingly complex interactions between microglia, astrocytes, lymphocytes, and neurons that underlie these processes. It is proposed that an enhanced understanding of microglia will yield improved therapies of central nervous system infections, since such therapies are, by and large, sorely needed.
The Genome Sequence ofMycoplasma hyopneumoniaeStrain 232, the Agent of Swine Mycoplasmosis
Authors: Minion F. Chris , Lefkowitz Elliot J. , Madsen Melissa L. , Cleary Barbara J. , Swartzell Steven M. , Mahairas Gregory G. 
Published: October 2004

ABSTRACTWe present the complete genome sequence ofMycoplasma hyopneumoniae, an important member of the porcine respiratory disease complex. The genome is composed of 892,758 bp and has an average G+C content of 28.6 mol%. There are 692 predicted protein coding sequences, the average protein size is 388 amino acids, and the mean coding density is 91%. Functions have been assigned to 304 (44%) of the predicted protein coding sequences, while 261 (38%) of the proteins are conserved hypothetical proteins and 127 (18%) are unique hypothetical proteins. There is a single 16S-23S rRNA operon, and there are 30 tRNA coding sequences. The cilium adhesin gene has six paralogs in the genome, only one of which contains the cilium binding site. The companion gene,P102, also has six paralogs. Gene families constitute 26.3% of the total coding sequences, and the largest family is the 34-member ABC transporter family. Protein secretion occurs through a truncated pathway consisting of SecA, SecY, SecD, PrsA, DnaK, Tig, and LepA. Some highly conserved eubacterial proteins, such as GroEL and GroES, are notably absent. The DnaK-DnaJ-GrpR complex is intact, providing the only control over protein folding. There are several proteases that might serve as virulence factors, and there are 53 coding sequences with prokaryotic lipoprotein lipid attachment sites. Unlike other mycoplasmas,M. hyopneumoniaecontains few genes with tandem repeat sequences that could be involved in phase switching or antigenic variation. Thus, it is not clear howM. hyopneumoniaeevades the immune response and establishes a chronic infection.
Crystal Structure of the YgfZ Protein from
Escherichia coli
Suggests a Folate-Dependent Regulatory Role in One-Carbon Metabolism
Authors: Teplyakov Alexey , Obmolova Galina , Sarikaya Elif , Pullalarevu Sadhana , Krajewski Wojciech , Galkin Andrey , Howard Andrew J. , Herzberg Osnat , Gilliland Gary L. 
Published: October 2004

ABSTRACT

The
ygfZ
gene product of
Escherichia coli
represents a large protein family conserved in bacteria to eukaryotes. The members of this family are uncharacterized proteins with marginal sequence similarity to the T-protein (aminomethyltransferase) of the glycine cleavage system. To assist with the functional assignment of the YgfZ family, the crystal structure of the
E. coli
protein was determined by multiwavelength anomalous diffraction. The protein molecule has a three-domain architecture with a central hydrophobic channel. The structure is very similar to that of bacterial dimethylglycine oxidase, an enzyme of the glycine betaine pathway and a homolog of the T-protein. Based on structural superposition, a folate-binding site was identified in the central channel of YgfZ, and the ability of YgfZ to bind folate derivatives was confirmed experimentally. However, in contrast to dimethylglycine oxidase and T-protein, the YgfZ family lacks amino acid conservation at the folate site, which implies that YgfZ is not an aminomethyltransferase but is likely a folate-dependent regulatory protein involved in one-carbon metabolism.
Tertiary Structure of
Staphylococcus aureus
Cell Wall Murein
Authors: Dmitriev Boris A. , Toukach Filip V. , Holst O. , Rietschel E. T. , Ehlers S. 
Published: October 2004

ABSTRACT

The recently described scaffold model of murein architecture depicts the gram-negative bacterial cell wall as a gel-like matrix composed of cross-linked glycan strands oriented perpendicularly to the plasma membrane while peptide bridges adopt a parallel orientation (B. A. Dmitriev, F. V. Toukach, K. J. Schaper, O. Holst, E. T. Rietschel, and S. Ehlers, J. Bacteriol. 185:3458-3468, 2003). Based on the scaffold model, we now present computer simulation studies on the peptidoglycan arrangement of the gram-positive organism
Staphylococcus aureus
, which show that the orientation of peptide bridges is critical for the highly cross-linked murein architecture of this microorganism. According to the proposed refined model, staphylococcal murein is composed of glycan and oligopeptide chains, both running in a plane that is perpendicular to the plasma membrane, with oligopeptide chains adopting a zigzag conformation and zippering adjacent glycan strands along their lengths. In contrast to previous models of murein in gram-positive bacteria, this model reflects the high degree of cross-linking that is the hallmark of the staphylococcal cell wall and is compatible with distinguishing features of
S. aureus
cytokinesis such as the triple consecutive alteration of the division plane orientation and the strictly centripetal mode of septum closure.