bluuebunny/crossref_metadata_2025 huggingface dataset:
Functional Role of the Front and Back Legs During a Track Start with Special Reference to an Inverted Pendulum Model in College Swimmers
Authors: Ikeda Yusuke , Ichikawa Hiroshi , Nara Rio , Baba Yasuhiro , Shimoyama Yoshimitsu , Kubo Yasuyuki
Published: June 2016

This study investigated factors that determine the velocity of the center of mass (CM) and flight distance from a track start to devise effective technical and physical training methods. Nine male and 5 female competitive swimmers participated in this study. Kinematics and ground reaction forces of the front and back legs were recorded using a video camera and force plates. The track start was modeled as an inverted pendulum system including a compliant leg, connecting the CM and front edge of the starting block. The increase in the horizontal velocity of the CM immediately after the start signal was closely correlated with the rotational component of the inverted pendulum. This rotational component at hands-off was significantly correlated with the average vertical force of the back plate from the start signal to hands-off (r = .967, P < .001). The flight distance / height was significantly correlated with the average vertical force of the front plate from the back foot-off to front foot-off (r = .783, P < .01). The results indicate that the legs on the starting block in the track start play a different role in the behavior of the inverted pendulum.
Physical Activity, Sensation Seeking, and Aggression as Injury Risk Factors in Young Swiss Men: A Population-Based Cohort Study
Authors: Martin-Diener Eva , Foster Simon , Mohler-Kuo Meichun , Martin Brian W.
Published: June 2016

Background:

This study investigates the relationships between physical activity (PA), sports participation and sensation seeking or aggression and injury risk in young men.

Methods:

A representative cohort study was conducted with 4686 conscripts for the Swiss army. Risk factors assessed at baseline were PA, the frequency of sports participation, sensation seeking, and aggression. The number of injuries during the past 12 months was reported 16 months after baseline. Exposure to moderate-tovigorous physical activity (MVPA) was estimated based on baseline PA.

Results:

Among conscripts, 48.5% reported at least 1 injury for the past 12 months. After accounting for exposure to MVPA, the most inactive individuals (reference group) had the highest injury risk and those with high levels of PA and weekly sports participation the lowest (Poisson regression analysis: incidence rate ratio = 0.14 [0.12–0.16]). Independent of activity level, sensation seeking increased cumulative injury incidence significantly (Logistic regression analysis [injured vs. not injured]: odds ratio = 1.29 [1.02–1.63]) and incidence rates marginally. Aggression was marginally associated only with cumulative injury incidence and only in those participating in daily sports.

Conclusions:

When accounting for exposure to PA, being inactive is a strong injury risk factor in young men, whereas the roles of the personality variables are less clear.
Women’s Lifestyle Physical Activity Program for African American Women: Fidelity Plan and Outcomes
Authors: Wilbur JoEllen , Schoeny Michael E. , Buchholz Susan W. , Fogg Louis , Miller Arlene Michaels , Braun Lynne T. , Halloway Shannon , Dancy Barbara L.
Published: June 2016

Background:

For interventions to be implemented effectively, fidelity must be documented. We evaluated fidelity delivery, receipt, and enactment of the 48-week Women’s Lifestyle Physical Activity Program conducted to increase physical activity and maintain weight in African American women.

Methods:

Three study conditions all received 6 group meetings; 1 also received 11 motivational interviewing personal calls (PCs), 1 received11 automated motivational message calls (ACs), and 1 received no calls. Group meeting delivery was assessed for adherence and competence. PC delivery was assessed with the Motivational Interviewing Treatment Integrity Code. Receipt was defined as group meeting attendance, completion of PCs, and listening to ACs. Enactment was number of weeks an accelerometer was worn.

Results:

For group meeting delivery, mean adherence was 80.8% and mean competence 2.9 of 3.0. Delivery of PCs did not reach criterion for competence. Receipt of more than one-half the dose was achieved for 84.9% of women for group meetings, 85.5% for PCs, and 42.1% for ACs. Higher group meeting attendance was associated with higher accelerometer steps at 24 weeks and lower BMI at 24 and 48 weeks.

Conclusions:

Fidelity measurement and examination of intervention delivery, receipt, and enactment are important to explicate conditions in which interventions are successful.
Are the Physical Activity Parenting Practices Reported by US and Canadian Parents Captured in Currently Published Instruments?
Authors: Mâsse Louise C. , O’Connor Teresia M. , Tu Andrew W. , Watts Allison W. , Beauchamp Mark R. , Hughes Sheryl O. , Baranowski Tom
Published: June 2016

Background:

The purpose of this study was to compare the physical activity parenting practices (PAPPs) parents report using with the PAPPs incorporated in the published literature.

Methods:

PAPPs in the literature were identified by reviewing the content of 74 published PAPP measures obtained from current systematic reviews supplemented with a literature search. The types of PAPPs used by parents were identified by surveying a stratified sample of 134 Canadian and US parents of 5- to 12 year-old children. Items from the literature and parent responses were coded using the same coding scheme. Differences between the PAPPs emphasized by the parents and the literature were examined.

Results:

Parents significantly emphasized different issues than what is measured in the literature (P < .001). Parents emphasized more control (13.6% vs. 6.9%), modeling and teaching (13.2% vs. 9.2%), and structural strategies (32.2% vs. 28.6%) and less autonomy support (11.8% vs. 14.0%), logistical support (9.9% vs. 12.8%), and responsiveness strategies (19.3% vs. 28.5%).

Conclusions:

Physical activity practices most often employed by parents are not the ones emphasized in current measures. The extent to which putting more emphasis on the areas identified by parents will increase the predictive validity of the measures warrants further examination.
Orbital-exchange and fractional quantum number excitations in an f-electron metal, Yb
2
Pt
2
Pb
Authors: Wu L. S. , Gannon W. J. , Zaliznyak I. A. , Tsvelik A. M. , Brockmann M. , Caux J.-S. , Kim M. S. , Qiu Y. , Copley J. R. D. , Ehlers G. , Podlesnyak A. , Aronson M. C.
Published: June 2016

Orbitals and charge go their separate ways

In certain materials at very low temperatures, an electron's spin can separate from its charge, zooming through the crystal in the form of a “spinon.” Such materials are usually one-dimensional, and their atoms have spins of 1/2. Wu
et al.
observed related behavior in a three-dimensional metal, Yb
2
Pt
2
Pb, where the Yb ions have a large magnetic moment that has its origin in the electrons' orbital motion rather than their spin. Neutron-scattering measurements indicated that these large magnetic moments can flip their direction through an exchange process similar to the one that occurs in spin 1/2 systems. This process results in effective charge-orbital separation.

Science
, this issue p.
1206
Water splitting–biosynthetic system with CO
2
reduction efficiencies exceeding photosynthesis
Authors: Liu Chong , Colón Brendan C. , Ziesack Marika , Silver Pamela A. , Nocera Daniel G.
Published: June 2016

Artificial photosynthesis steps up

Photosynthesis fixes CO
2
from the air by using sunlight. Industrial mimics of photosynthesis seek to convert CO
2
directly into biomass, fuels, or other useful products. Improving on a previous artificial photosynthesis design, Liu
et al.
combined the hydrogen-oxidizing bacterium
Raistonia eutropha
with a cobalt-phosphorus water-splitting catalyst. This biocompatible self-healing electrode circumvented the toxicity challenges of previous designs and allowed it to operate aerobically. When combined with solar photovoltaic cells, solar-to-chemical conversion rates should become nearly an order of magnitude more efficient than natural photosynthesis.

Science
, this issue p.
1210
Ecologically relevant data are policy-relevant data
Authors: Rochman Chelsea M.
Published: June 2016

Microplastics reduce fish hatching success and survival
Phase 1 trial of vocimagene amiretrorepvec and 5-fluorocytosine for recurrent high-grade glioma
Authors: Cloughesy Timothy F. , Landolfi Joseph , Hogan Daniel J. , Bloomfield Stephen , Carter Bob , Chen Clark C. , Elder J. Bradley , Kalkanis Steven N. , Kesari Santosh , Lai Albert , Lee Ian Y. , Liau Linda M. , Mikkelsen Tom , Nghiemphu Phioanh Leia , Piccioni David , Walbert Tobias , Chu Alice , Das Asha , Diago Oscar R. , Gammon Dawn , Gruber Harry E. , Hanna Michelle , Jolly Douglas J. , Kasahara Noriyuki , McCarthy David , Mitchell Leah , Ostertag Derek , Robbins Joan M. , Rodriguez-Aguirre Maria , Vogelbaum Michael A.
Published: June 2016

Toca 511 and Toca FC show promising results in treating recurrent high-grade glioma, and a specific molecular signature correlates with treatment-related survival.
Made-by-measure
Authors: Shalek Alex K.
Published: June 2016

Single-cell RNA-Seq can be used to rationally guide the selection of precision cancer therapies, as demonstrated in renal cell carcinoma.
Clostridium difficile: its disease and toxins
Authors: Lyerly D M , Krivan H C , Wilkins T D
Published: June 2016

Clostridium difficile is the etiologic agent of pseudomembranous colitis, a severe, sometimes fatal disease that occurs in adults undergoing antimicrobial therapy. The disease, ironically, has been most effectively treated with antibiotics, although some of the newer methods of treatment such as the replacement of the bowel flora may prove more beneficial for patients who continue to relapse with pseudomembranous colitis. The organism produces two potent exotoxins designated toxin A and toxin B. Toxin A is an enterotoxin believed to be responsible for the diarrhea and mucosal tissue damage which occur during the disease. Toxin B is an extremely potent cytotoxin, but its role in the disease has not been as well studied. There appears to be a cascade of events which result in the expression of the activity of these toxins, and these events, ranging from the recognition of a trisaccharide receptor by toxin A to the synergistic action of the toxins and their possible dissemination in the body, are discussed in this review. The advantages and disadvantages of the various assays, including tissue culture assay, enzyme immunoassay, and latex agglutination, currently used in the clinical diagnosis of the disease also are discussed.
Serum bactericidal test
Authors: Stratton C W
Published: June 2016

The serum bactericidal test represents one of the few in vitro tests performed in the clinical microbiology laboratory that combines the interaction of the pathogen, the antimicrobial agent, and the patient. Although the use of such a test antedates the antimicrobial era, its performance, results, and interpretation have been subject to question and controversy. Much of the confusion concerning the serum bactericidal test can be avoided by an understanding of the various factors which influence bactericidal testing. In addition, the methodologic aspects of the serum bactericidal test have recently been addressed and should place this test on firmer ground. New information on the clinical utility of this test is becoming available; additional data are needed to establish more clearly the usefulness of the serum bactericidal test in specific infections. Such clinical trials from multiple centers will enable firmer recommendations for the future use of the serum bactericidal test.
Pathogenicity and virulence: another view
Authors: Isenberg H D
Published: June 2016

The concepts of pathogenicity and virulence have governed our perception of microbial harmfulness since the time of Pasteur and Koch. These concepts resulted in the recognition and identification of numerous etiological agents and provided natural and synthetic agents effective in therapy and prevention of diseases. However, Koch's postulates--the premier product of this view--place the onus of harmfulness solely on the microbial world. Our recent experiences with polymicrobic and nosocomial infections, legionellosis, and acquired immunodeficiency syndrome point to the host as the major determinant of disease. The principles of parasitism, enunciated by Theobold Smith, approximate more accurately the disturbances of the host-parasite equilibrium we designate as infection. Many complex attributes of microbial anatomy and physiology have been obscured by our dependency on the pure-culture technique. For example, bacterial attachment organelles and the production of exopolysaccharides enable microorganisms to interact with mammalian glycocalyces and specific receptors. In addition, selection, through the use of therapeutic agents, aids in the progression of environmental organisms to members of the intimate human biosphere, with the potential to complicate the recovery of patients. These factors emphasize further the pivotal significance of host reactions in infections. Parasitism, in its negative aspects, explains the emergence of "new" infections that involve harm to more than host organs and cells: we may encounter subtler infections that reveal parasitic and host cell nucleic acid interactions in a form of genomic parasitism.
Antibiotic combinations: should they be tested?
Authors: Eliopoulos G M , Eliopoulos C T
Published: June 2016

When antibiotic combinations are used to provide a broader spectrum of antimicrobial activity or in an attempt to prevent the emergence of resistant organisms, it is rarely necessary or practical to perform tests of drug interactions in vitro. In vitro testing of combinations may be useful when combinations are used in an attempt to attain synergistic interactions. In some cases, screening methods can be used as substitutes for formal synergy testing. This paper examines the mechanisms of antibiotic interaction leading to synergism or antagonism, surveys attempts to correlate in vitro observations with efficacy in animal models, and reviews clinical data providing evidence for or against a useful role of synergistic antibiotic interactions in the treatment of human infections.
Methicillin-resistant staphylococci
Authors: Chambers H F
Published: June 2016

Strains of staphylococci resistant to methicillin were identified immediately after introduction of this drug. Methicillin-resistant strains have unusual properties, the most notable of which is extreme variability in expression of the resistance trait. The conditions associated with this heterogeneous expression of resistance are described. Methicillin resistance is associated with production of a unique penicillin-binding protein (PBP), 2a, which is bound and inactivated only at high concentrations of beta-lactam antibiotics. PBP2a appears to be encoded by the mec determinant, which also is unique to methicillin-resistant strains. The relationships between PBP2a and expression of resistance and implications for the mechanism of resistance are discussed. The heterogeneous expression of methicillin resistance by staphylococci poses problems in the detection of resistant strains. Experience with several susceptibility test methods is reviewed and guidelines for performance of these tests are given. Treatment of infections caused by methicillin-resistant staphylococci is discussed. Vancomycin is the treatment of choice. Alternatives have been few because methicillin-resistant strains often are resistant to multiple antibiotics in addition to beta-lactam antibiotics. New agents which are active against methicillin-resistant staphylococci are becoming available, and their potential role in treatment is discussed.
Overview of medically important antifungal azole derivatives
Authors: Fromtling R A
Published: June 2016

Fungal infections are a major burden to the health and welfare of modern humans. They range from simply cosmetic, non-life-threatening skin infections to severe, systemic infections that may lead to significant debilitation or death. The selection of chemotherapeutic agents useful for the treatment of fungal infections is small. In this overview, a major chemical group with antifungal activity, the azole derivatives, is examined. Included are historical and state of the art information on the in vitro activity, experimental in vivo activity, mode of action, pharmacokinetics, clinical studies, and uses and adverse reactions of imidazoles currently marketed (clotrimazole, miconazole, econazole, ketoconazole, bifonazole, butoconazole, croconazole, fenticonazole, isoconazole, oxiconazole, sulconazole, and tioconazole) and under development (aliconazole and omoconazole), as well as triazoles currently marketed (terconazole) and under development (fluconazole, itraconazole, vibunazole, alteconazole, and ICI 195,739).
Detection of urinary tract infections by rapid methods
Authors: Pezzlo M
Published: June 2016

A review of rapid urine screens for detection of bacteriuria and pyuria demonstrates a number of available alternatives to the culture method. Selection of one or more of these systems for routine use is dependent upon the laboratory and the patient population being tested. The laboratory approach to the diagnosis of urinary tract infection should consider the clinical diagnosis of the patient whenever possible. Keeping in mind that quantitative urine cultures alone cannot be used to detect infection in some patient populations unless lower colony counts are considered, a rapid screen may be a more practical approach. It has become accepted that 10(5) CFU/ml can no longer be used as the standard for all patient groups, that pyuria often is important in making the diagnosis of a urinary tract infection, and that most of the rapid screens are more sensitive than the culture method at 10(5) CFU/ml. Presently, no one approach can be recommended for all laboratories and all patient groups. However, each diagnostic laboratory should select one approach which is best for its situation. It is not practical, efficient, or cost effective to define a protocol for each possible clinical condition; however, all should be considered when developing a protocol. This protocol should be compatible with the patient population and communicated to the physicians. Use of a rapid screen should be beneficial to the patient, the physician, and the laboratory.
Laboratory, clinical, and epidemiological aspects of coagulase-negative staphylococci
Authors: Pfaller M A , Herwaldt L A
Published: June 2016

Coagulase-negative staphylococci, particularly Staphylococcus epidermidis, are increasingly important causes of nosocomial infection. Microbiologists and clinicians no longer can afford to disregard clinical isolates of coagulase-negative staphylococci as contaminants. Accurate species identification and antimicrobial susceptibility testing, in a clinically relevant time frame, are important aids in the diagnosis and management of serious coagulase-negative staphylococcal infections. Emphasis in the clinical laboratory should be placed on the routine identification of S. epidermidis and Staphylococcus saprophyticus, with identification of other species of coagulase-negative staphylococci as clinically indicated. The application of newer techniques, such as plasmid analysis and tests for slime production and adherence, contribute to our understanding of the epidemiology and pathogenesis of coagulase-negative staphylococci and may also be helpful in establishing the diagnosis of infection.
Epstein-Barr virus and human diseases: recent advances in diagnosis
Authors: Okano M , Thiele G M , Davis J R , Grierson H L , Purtilo D T
Published: June 2016

Since the discovery of Epstein-Barr virus (EBV) from a cultured Burkitt's lymphoma cell line in 1964, the virus has been associated with Burkitt's lymphoma, nasopharyngeal carcinoma, and infectious mononucleosis. During the recent decade, EBV has been etiologically implicated in a broad spectrum of human diseases. The precise role of this virus in these diseases is not well understood, but clearly, defective immunosurveillance against the virus may permit an uncontrolled proliferation of EBV-infected cells. As a result, a growing number of cases of EBV-associated B-cell proliferative diseases or lymphoma have been noted in patients with primary and acquired immunodeficiencies. These lymphoproliferative diseases and others, such as chronic mononucleosis syndrome, are leading to new areas of investigation which are providing information regarding the pathogenetic mechanisms of EBV-induced diseases. The early accurate diagnosis of EBV infection can be achieved by performing EBV-specific serology, detecting for EBV-determined nuclear antigen in tissues, establishing spontaneous lymphoid cell lines, and using molecular hybridization techniques for demonstrating the presence of viral genome in affected lesions.
Leprosy
Authors: Hastings R C , Gillis T P , Krahenbuhl J L , Franzblau S G
Published: June 2016

Leprosy affects over 10 million people in the world. The disease is a model of graded cell-mediated immunity, in this case to the causative organism, Mycobacterium leprae. The clinical manifestations are due to (i) bacterial progression, (ii) immunologic responses of the host, (iii) peripheral nerve damage due to either or both bacterial progression and immunologic responses of the host, and (iv) preventable secondary deformities following nerve damage, which account for most of the stigma of the disease. Treatment modalities are now available to control or minimize the effects of bacterial progression, harmful immunologic responses of the host, peripheral nerve damage, and secondary deformities. Unique biochemical characteristics of M. leprae reside in the cell wall and associated macromolecules. Some of these molecules are potent immunogens in humans, while others constitute the structural integrity of the bacillus. Proteins of M. leprae are currently under intensive investigation as a result of deoxyribonucleic acid cloning of M. leprae genes. Structure-function and antigenic relationships of M. leprae proteins should become available by using recombinant deoxyribonucleic acid procedures coupled with T- and B-cell cloning to advance our understanding of the immunologic reactions encountered in Hansen's disease. Until recently, the study of the immunology of leprosy has been stymied by the lack of immunologically specific M. leprae antigens. The definition of specific antigens and production of recombinant and synthetic immunologic reagents have fostered state-of-the-art research efforts into new immunodiagnostic procedures and development of a leprosy vaccine. Also discussed is progress in understanding of the mechanism(s) underlying the M. leprae-specific immunodeficiency associated with lepromatous leprosy, including the role of suppressor T cells and defective macrophage function. Metabolic studies of M. leprae suggest intact catabolic pathways and energy generation with purine bases and catalase as possible growth factors. Special attention may also need to be given to biophysical parameters for eventual in vitro cultivation. Rapid in vitro systems, using quantitation of bacillary metabolic activity, may soon replace the lengthy mouse footpad test for determining the viability and drug susceptibility of the leprosy bacillus.
Pertussis: the disease and new diagnostic methods
Authors: Friedman R L
Published: June 2016

Bordetella pertussis, the causative agent of whooping cough, produces an acute and chronic respiratory infection in infants and young children. B. pertussis is still a major health problem of young children throughout the world even though effective immunization against whooping cough is available. While predominantly a childhood disease, it has been reported also to be a cause of persistent cough in adults. This review discusses the numerous bacterial virulence factors that may play roles in the pathogenesis of pertussis and in immunity to infection. The present problems with pertussis diagnosis, recent advances, and future prospects for new and improved rapid diagnostics tests also are explored.
Human viral gastroenteritis
Authors: Christensen M L
Published: June 2016

During the last 15 years, several different groups of fastidious viruses that are responsible for a large proportion of acute viral gastroenteritis cases have been discovered by the electron microscopic examination of stool specimens. This disease is one of the most prevalent and serious clinical syndromes seen around the world, especially in children. Rotaviruses, in the family Reoviridae, and fastidious fecal adenoviruses account for much of the viral gastroenteritis in infants and young children, whereas the small caliciviruses and unclassified astroviruses, and possibly enteric coronaviruses, are responsible for significantly fewer cases overall. In addition to electron microscopy, enzyme immunoassays and other rapid antigen detection systems have been developed to detect rotaviruses and fastidious fecal adenoviruses in the stool specimens of both nonhospitalized patients and those hospitalized for dehydration and electrolyte imbalance. Experimental rotavirus vaccines have also been developed, due to the prevalence and seriousness of rotavirus infection. The small, unclassified Norwalk virus and morphologically similar viruses are responsible for large and small outbreaks of acute gastroenteritis in older children, adolescents, and adults. Hospitalization of older patients infected with these viruses is usually not required, and their laboratory diagnoses have been limited primarily to research laboratories.
Crohn's disease and the mycobacterioses: a review and comparison of two disease entities
Authors: Chiodini R J
Published: June 2016

Crohn's disease is a chronic granulomatous ileocolitis, of unknown etiology, which generally affects the patient during the prime of life. Medical treatment is supportive at best, and patients afflicted with this disorder generally live with chronic pain, in and out of hospitals, throughout their lives. The disease bears the name of the investigator who convincingly distinguished this disease from intestinal tuberculosis in 1932. This distinction was not universally accepted, and the notion of a mycobacterial etiology has never been fully dismissed. Nevertheless, it was 46 years after the distinction of Crohn's disease and intestinal tuberculosis before research attempting to reassociate mycobacteria and Crohn's disease was published. Recently, there has been a surge of interest in the possible association of mycobacteria and Crohn's disease due largely to the isolation of genetically identical pathogenic Mycobacterium paratuberculosis from several patients with Crohn's disease in the United States, the Netherlands, Australia, and France. These pathogenic organisms have been isolated from only a few patients, and direct evidence for their involvement in the disease process is not clear; however, M. paratuberculosis is an obligate intracellular organism and strict pathogen, which strongly suggests some etiologic role. Immunologic evidence of a mycobacterial etiology, as assessed by humoral immune determinations, has been conflicting, but evaluation of the more relevant cellular immunity has not been performed. Data from histochemical searches for mycobacteria in Crohn's disease tissues have been equally conflicting, with acid-fast bacilli detected in 0 to 35% of patients. Animal model studies have demonstrated the pathogenic potential of isolates as well as elucidated the complexity of mycobacterial-intestinal interactions. Treatment of Crohn's disease patients with antimycobacterial agent has not been fully assessed, although case reports suggest efficacy. The similarities in the pathology, epidemiology, and chemotherapy of Crohn's disease and the mycobacterioses are discussed. The issue is fraught with controversy, and the data generated on the association of mycobacteria and Crohn's disease are in their infantile stages so that a general conclusion on the legitimacy of this association cannot be made. While no firm evidence clearly implicates mycobacteria as an etiologic agent of Crohn's disease, the notion is supported by suggestive and circumstantial evidence and a remarkable similarity of Crohn's disease to known mycobacterial diseases.
Acquisition of cytomegalovirus infection: an update
Authors: Forbes B A
Published: June 2016

Human cytomegalovirus (CMV) is a ubiquitous deoxyribonucleic acid virus that commonly infects a majority of individuals at some time during their life. Although most of these CMV infections are asymptomatic, certain patient groups are at risk to develop serious illness. Understanding the epidemiology of this virus is a key element in the development of strategies for preventing CMV disease. However, a number of features of this virus complicate such understanding. Following infection, CMV can remain latent, with subsequent reactivation; the factors controlling latency and reactivation and those factors which determine whether a CMV infection will be symptomatic are unknown. CMV disease can be acquired by natural routes, including horizontal and vertical transmission. Due to the ubiquity of CMV, the delineation of CMV transmission by these natural routes is complicated by the myriad of possible sources. Moreover, concerns over the risk of CMV transmission to the seronegative pregnant female have been raised in relation to preventing CMV transmission. By using molecular biologic techniques, much knowledge has been gained regarding the transmission of CMV disease by natural routes; however, a number of questions remain unanswered. The transmission of CMV infection by natural routes is therefore reviewed and the issues are highlighted. Primary infection, reactivation, and reinfection are the types of active CMV infections that can occur in an immunocompromised patient. In addition to natural routes of infection, introduction of presumably latently infected organs and requirements for multiple blood transfusions increase potential exposure to CMV in the immunocompromised patient. Understanding the epidemiology of CMV infections in the immunocompromised patient is difficult and in some instances controversial due to the complexity and interdependency of a number of factors which lead to CMV infection. In an immunocompromised individual, a major risk factor in developing overt CMV-related disease is associated with the serological status of an organ donor, the recipient, and the blood product given to these patients. In addition, a large body of inferential data supports the transmission of CMV by blood products or organs from seropositive donors; however, the mechanisms by which transmission occurs remain unclear. The possible sources and mechanisms of transmission of CMV infections in the immunocompromised host are reviewed. Lastly, strategies for the ultimate prevention of CMV disease are discussed in light of the epidemiology of CMV infections. To date, these strategies have included use of CMV-seronegative blood products or organs, antiviral agents, and vaccines.(ABSTRACT TRUNCATED AT 400 WORDS)
Nucleic acid amplification in vitro: detection of sequences with low copy numbers and application to diagnosis of human immunodeficiency virus type 1 infection
Authors: Guatelli J C , Gingeras T R , Richman D D
Published: June 2016

The enzymatic amplification of specific nucleic acid sequences in vitro has revolutionized the use of nucleic acid hybridization assays for viral detection. With this method, the copy number of a pathogen-specific sequence is increased several orders of magnitude before detection is attempted. The sensitivity and specificity of detection are thus markedly improved. Mullis and Faloona devised the first method of sequence amplification in vitro, the polymerase chain reaction (K.B. Mullis and F.A. Faloona, Methods Enzymol. 155:355-350, 1987). By this method, synthetic oligonucleotide primers direct repeated, target-specific, deoxyribonucleic acid-synthetic reactions, resulting in an exponential increase in the amount of the specific target sequence. The application of sequence amplification to viral detection was initially performed with human immunodeficiency virus type 1 and human T-cell lymphoma virus type I. In principle, however, this approach can be applied to the detection of any deoxyribonucleic or ribonucleic acid virus; the only requirement is that sufficient nucleotide sequence data exist to allow the synthesis of target-specific oligonucleotide primers. The use of target amplification in vitro will permit a variety of studies of viral pathogenesis which have not been feasible because of the low copy number of the viral nucleic acids in infected material. This approach is particularly applicable to the study of human retroviral infections, which are chronic and persistent and are characterized by low titers of virus in tissues. In addition, target amplification in vitro will facilitate the development of new methods of sequence detection, which will be useful for rapid viral diagnosis in the clinical laboratory.
Anisakiasis
Authors: Sakanari J A , McKerrow J H
Published: June 2016

Anisakiasis is a zoonotic disease caused by the ingestion of larval nematodes in raw seafood dishes such as sushi, sashimi, ceviche, and pickled herring. Symptoms of anisakiasis include abdominal pain, nausea, vomiting, and diarrhea. Because symptoms are vague, this disease is often misdiagnosed as appendicitis, acute abdomen, stomach ulcers, or ileitis. Endoscopic examination with biopsy forceps has facilitated the diagnosis of gastric anisakiasis. Worms can be removed and identified, and a definitive diagnosis can be made. Patients generally recover with no further evidence of disease. Worms can become invasive, however, and migrate beyond the stomach, penetrating the intestine, omentum, liver, pancreas, and probably the lungs. Surgery is often necessary for treatment of invasive anisakiasis. With the increase in popularity of eating lightly cooked or raw fish dishes, the number of cases of anisakiasis may be expected to increase.
Erysipelothrix rhusiopathiae: an occupational pathogen
Authors: Reboli A C , Farrar W E
Published: June 2016

Erysipelothrix rhusiopathiae is a nonsporulating, gram-positive, rod-shaped bacterium which was identified more than 100 years ago as the etiologic agent of swine erysipelas. Since then, it has been found to cause infection in several dozen species of mammals and other animals. Humans become infected through exposure to infected or contaminated animals or animal products. By far the most common type of human infection is a localized, self-limited cutaneous lesion, erysipeloid. Diffuse cutaneous and systemic infections occur rarely. Approximately 50 cases of endocarditis have been reported; all but one recent case have involved native valves. The organism may be isolated from biopsy or blood specimens on standard culture media. It is identified by morphology, lack of motility, and biochemical characteristics; identification may be confirmed by the mouse protection test. It is susceptible to penicillins, cephalosporins, erythromycin, and clindamycin, but it is often resistant to many other antibiotics, including vancomycin, a drug frequently used in empiric therapy for infections due to gram-positive bacteria.
Fluoroquinolone antimicrobial agents
Authors: Wolfson J S , Hooper D C
Published: June 2016

The fluoroquinolones, a new class of potent orally absorbed antimicrobial agents, are reviewed, considering structure, mechanisms of action and resistance, spectrum, variables affecting activity in vitro, pharmacokinetic properties, clinical efficacy, emergence of resistance, and tolerability. The primary bacterial target is the enzyme deoxyribonucleic acid gyrase. Bacterial resistance occurs by chromosomal mutations altering deoxyribonucleic acid gyrase and decreasing drug permeation. The drugs are bactericidal and potent in vitro against members of the family Enterobacteriaceae, Haemophilus spp., and Neisseria spp., have good activity against Pseudomonas aeruginosa and staphylococci, and (with several exceptions) are less potent against streptococci and have fair to poor activity against anaerobic species. Potency in vitro decreases in the presence of low pH, magnesium ions, or urine but is little affected by different media, increased inoculum, or serum. The effects of the drugs in combination with a beta-lactam or aminoglycoside are often additive, occasionally synergistic, and rarely antagonistic. The agents are orally absorbed, require at most twice-daily dosing, and achieve high concentrations in urine, feces, and kidney and good concentrations in lung, bone, prostate, and other tissues. The drugs are efficacious in treatment of a variety of bacterial infections, including uncomplicated and complicated urinary tract infections, bacterial gastroenteritis, and gonorrhea, and show promise for therapy of prostatitis, respiratory tract infections, osteomyelitis, and cutaneous infections, particularly when caused by aerobic gram-negative bacilli. Fluoroquinolones have also proved to be efficacious for prophylaxis against travelers' diarrhea and infection with gram-negative bacilli in neutropenic patients. The drugs are effective in eliminating carriage of Neisseria meningitidis. Patient tolerability appears acceptable, with gastrointestinal or central nervous system toxicities occurring most commonly, but only rarely necessitating discontinuance of therapy. In 17 of 18 prospective, randomized, double-blind comparisons with another agent or placebo, fluoroquinolones were tolerated as well as or better than the comparison regimen. Bacterial resistance has been uncommonly documented but occurs, most notably with P. aeruginosa and Staphylococcus aureus and occasionally other species for which the therapeutic ratio is less favorable. Fluoroquinolones offer an efficacious, well-tolerated, and cost-effective alternative to parenteral therapies of selected infections.
Immunoserology of infectious diseases
Authors: James K
Published: June 2016

The immune response to microorganisms not only participates in the elimination of unwanted organisms from the body, but also assists in diagnosis of infectious diseases. The nonspecific immune response is the first line of defense, assisting the body until the specific immune response can be mobilized to provide protective mechanisms. The specific immune response involves humoral or cell-mediated immunity or both, dependent on the nature of the organism and its site of sequestration. A variety of test systems have been developed to identify the causative organisms of infectious diseases. Test systems used in immunoserology have classically included methods of detecting antigen-antibody reactions which range from complement fixation to immunoassay methods. Relevant test systems for detecting antigens and antibodies are described. With numerous test systems available to detect antigens and antibodies, there can be confusion regarding selection of the appropriate system for each application. Methods for detecting antibody to verify immunity differ from immunologic methods to diagnose disease. Techniques to detect soluble antigens present in active infectious states may appear similar to those used to detect antibody, but their differences should be appreciated.
Vaccinia virus vectors: new strategies for producing recombinant vaccines
Authors: Hruby D E
Published: June 2016

The development and continued refinement of techniques for the efficient insertion and expression of heterologous DNA sequences from within the genomic context of infectious vaccinia virus recombinants are among the most promising current approaches towards effective immunoprophylaxis against a variety of protozoan, viral, and bacterial human pathogens. Because of its medical relevance, this area is the subject of intense research interest and has evolved rapidly during the past several years. This review (i) provides an updated overview of the technology that exists for assembling recombinant vaccinia virus strains, (ii) discusses the advantages and disadvantages of these approaches, (iii) outlines the areas of outgoing research directed towards overcoming the limitations of current techniques, and (iv) provides some insight (i.e., speculation) about probable future refinements in the use of vaccinia virus as a vector.
Pneumococcal resistance to antibiotics
Authors: Klugman K P
Published: June 2016

The geographic distribution of pneumococci resistant to one or more of the antibiotics penicillin, erythromycin, trimethoprim-sulfamethoxazole, and tetracycline appears to be expanding, and there exist foci of resistance to chloramphenicol and rifampin. Multiply resistant pneumococci are being encountered more commonly and are more often community acquired. Factors associated with infection caused by resistant pneumococci include young age, duration of hospitalization, infection with a pneumococcus of serogroup 6, 19, or 23 or serotype 14, and exposure to antibiotics to which the strain is resistant. At present, the most useful drugs for the management of resistant pneumococcal infections are cefotaxime, ceftriaxone, vancomycin, and rifampin. If the strains are susceptible, chloramphenicol may be useful as an alternative, less expensive agent. Appropriate interventions for the control of resistant pneumococcal outbreaks include investigation of the prevalence of resistant strains, isolation of patients, possible treatment of carriers, and reduction of usage of antibiotics to which the strain is resistant. The molecular mechanisms of penicillin resistance are related to the structure and function of penicillin-binding proteins, and the mechanisms of resistance to other agents involved in multiple resistance are being elucidated. Recognition is increasing of the standard screening procedure for penicillin resistance, using a 1-microgram oxacillin disk.
Bacterial spores and chemical sporicidal agents
Authors: Russell A D
Published: June 2016

Bacterial spores are among the most resistant of all living cells to biocides, although the response depends on the stage of sporulation. The development of resistance to some agents such as chlorhexidine occurs much earlier in sporulation than does resistance to glutaraldehyde, which is a very late event. During germination or outgrowth or both, resistance is lost and the cells become as susceptible to biocides as nonsporulating bacteria. Mechanisms of spore resistance to, and the action of, biocides are discussed, and possible means of enhancing antispore activity are considered. The clinical and other uses of sporicidal and sporostatic chemical agents are described.
Serology of coccidioidomycosis
Authors: Pappagianis D , Zimmer B L
Published: June 2016

Serologic tests have assisted in the diagnosis and prognosis of coccidioidomycosis for a half-century. The causative agent, Coccidioides immitis, is a dimorphic fungus existing in a hyphal form with arthroconidia in nature and in the usual culture. The arthroconidia represent the inhaled infective forms which in vivo and under special laboratory conditions form spherules which endosporulate. The culture filtrate/autolysate (coccidioidin) from the hyphal phase has provided antigens of suitable reliability for currently used serologic tests. These tests are primarily to determine the two major antibody responses: the early immunoglobulin M (IgM) response is useful in the diagnosis of acute primary coccidioidomycosis. Later, IgG is produced and usually outlasts the IgM, persisting in chronic coccidioidomycosis. The IgM is detectable by tube precipitin, a corresponding immunodiffusion, or latex particle agglutination tests. The pertinent antigen(s) is heat stable and pronase resistant and appears to be largely carbohydrate, mainly mannose with some 3-O-methyl mannose. The IgG detectable in the serum and other body fluids by complement fixation and a corresponding immuno-diffusion is useful in diagnosis, and its quantitation provides an indicator of progression of disease (increasing titer) or regression (decreasing titer). The pertinent antigen appears to be a heat-labile, pronase-sensitive protein which in an unreduced form has a molecular weight of 110,000. A third very useful serologic procedure is the exoantigen test for identification of putative cultures of C. immitis.
Candida albicans strain delineation
Authors: Merz W G
Published: June 2016

Candida albicans is a major opportunistic pathogen causing a wide spectrum of disease in human beings. Methods for strain delineation of this species to assess or predict virulence or to conduct epidemiologic or pathogenetic investigations have been developed. Although factors associated with virulence have been identified, there is no rapid system to quantitate them in a clinical laboratory. Therefore, many typing methods are based on variable phenotypic characteristics within this species including morphotyping, serotyping, antibiogram, resistogram typing, biotyping, biotyping based on commercial carbon assimilation patterns, enzyme profiles, sensitivity to yeast killer toxins, and typing based on protein variability. Phenotypically defined strains generally do not correlate with the pathogenic potential of a strain with the exception of morphotyping. However, these methods can be useful in epidemiologic investigations; for example, they have revealed that most individuals harbor one strain and that infections are frequently due to an endogenous strain. Problems with these methods usually relate to their discriminatory power. When this is maximized, reproducibility (especially between laboratories) suffers. Recently, methods based on differences in DNA structure (genotyping) for strain delineation have been developed, including electrophoretic karyotyping and restriction enzyme fragment length polymorphisms. The development of a computer-assisted data bank and analysis for these genotypic strain delineators will open investigations into the pathogenesis of this infection and permit epidemiologic studies previously not possible with this important human pathogen.
Candida mannan: chemistry, suppression of cell-mediated immunity, and possible mechanisms of action
Authors: Nelson R D , Shibata N , Podzorski R P , Herron M J
Published: June 2016

The ability of Candida albicans to establish an infection involves multiple components of this fungal pathogen, but its ability to persist in host tissue may involve primarily the immunosuppressive property of a major cell wall glycoprotein, mannan. Mannan and oligosaccharide fragments of mannan are potent inhibitors of cell-mediated immunity and appear to reproduce the immune deficit of patients with the mucocutaneous form of candidiasis. However, neither the exact structures of these inhibitory species nor their mechanisms of action have yet been clearly defined. Different investigators have proposed that mannan or mannan catabolites act upon monocytes or suppressor T lymphocytes, but research from unrelated areas has provided still other possibilities for consideration. These include interference with cytokine activities, lymphocyte-monocyte interactions, and leukocyte homing. To stimulate further research of the immunosuppressive property of C. albicans mannan, we have reviewed (i) the relationship of mannan to other antigens and virulence factors of the fungus; (ii) the chemistry of mannan, together with methods for preparation of mannan and mannan fragments; and (iii) the historical evidence for immunosuppression by Candida mannan and the mechanisms currently proposed for this property; and (iv) we have speculated upon still other mechanisms by which mannan might influence host defense functions. It is possible that understanding the immunosuppressive effects of mannan will provide clues to novel therapies for candidiasis that will enhance the efficacy of both available and future anti-Candida agents.