bluuebunny/crossref_metadata_2025_split huggingface dataset:
Folding and stability of the ligand‐binding domain of the glucocorticoid receptor
Authors: McLaughlin Stephen H. , Jackson Sophie E. 
Published: October 2002

AbstractA complex pathway involving many molecular chaperones has been proposed for the folding, assembly, and maintenance of a high‐affinity ligand‐binding form of steroid receptors in vivo, including the glucocorticoid receptor. To better understand this intricate folding and assembly process, we studied the folding of the ligand‐binding domain of the glucocorticoid receptor in vitro. We found that this domain can be refolded into a compact, highly structured state in vitro in the absence of chaperones. However, the presence of zwitterionic detergent is required to maintain the domain in a soluble form. In this state, the protein is dimeric and has considerable helical structure as shown by far‐UV circular dichroism. Further investigation of the properties of this in vitro refolded state show that it is stable and resistant to denaturation by heat or low concentrations of chemical denaturants. A detailed analysis of the unfolding equilibria using three different structural probes demonstrated that this state unfolds via a highly populated dimeric intermediate state. Together, these data clearly show that the ligand‐binding domain of the glucocorticoid receptor does not require chaperones for folding per se. However, this in vitro refolded state binds the ligand dexamethasone only weakly (Kd = 45 μM) compared to the in vivo assembled receptor (Kd = 3.4 nM). We suggest that the role of Hsp90 and associated chaperones is to bind to, and stabilize, a specific conformational state of the receptor which binds ligand with high affinity.
A Three-dimensional Finite Element Model for Arterial Clamping
Authors: Gasser Thomas C. , Schulze-Bauer Christian A. J. , Holzapfel Gerhard A. 
Published: October 2002

Abstract
Clamp induced injuries of the arterial wall may determine the outcome of surgical procedures. Thus, it is important to investigate the underlying mechanical effects. We present a three-dimensional finite element model, which allows the study of the mechanical response of an artery–treated as a two-layer tube-during arterial clamping. The important residual stresses, which are associated with the load-free configuration of the artery, are also considered. In particular, the finite element analysis of the deformation process of a clamped artery and the associated stress distribution is presented. Within the clamping area a zone of axial tensile peak-stresses was identified, which (may) cause intimal and medial injury. This is an additional injury mechanism, which clearly differs from the commonly assumed wall damage occurring due to compression between the jaws of the clamp. The proposed numerical model provides essential insights into the mechanics of the clamping procedure and the associated injury mechanisms. It allows detailed parameter studies on a virtual clamped artery, which can not be performed with other methodologies. This approach has the potential to identify the most appropriate clamps for certain types of arteries and to guide optimal clamp design.
Influence of Connection Geometry and SVC-IVC Flow Rate Ratio on Flow Structures within the Total Cavopulmonary Connection: A Numerical Study
Authors: Khunatorn Yottana , Mahalingam Shankar , DeGroff Curt G. , Shandas Robin 
Published: October 2002

AbstractThe total cavopulmonary connection (TCPC) is a palliative cardiothoracic surgical procedure used in patients with one functioning ventricle that excludes the heart from the systemic venous to pulmonary artery pathway. Blood in the superior and inferior vena cavae (SVC, IVC) is diverted directly to the pulmonary arteries. Since only one ventricle is left in the circulation, minimizing pressure drop by optimizing connection geometry becomes crucial. Although there have been numerical and in–vitro studies documenting the effect of connection geometry on overall pressure drop, there is little published data examining the effect of SVC-IVC flow rate ratio on detailed fluid mechanical structures within the various connection geometries. We present here results from a numerical study of the TCPC connection, configured with various connections and SVC:IVC flow ratios. The role of major flow parameters: shear stress, secondary flow, recirculation regions, flow stagnation regions, and flow separation, was examined. Results show a complex interplay among connection geometry, flow rate ratio and the types and effects of the various flow parameters described above. Significant changes in flow structures affected local distribution of pressure, which in turn changed overall pressure drop. Likewise, changes in local flow structure also produced changes in maximum shear stress values; this may have consequences for platelet activation and thrombus formation in the clinical situation. This study sheds light on the local flow structures created by the various connections and flow configurations and as such, provides an additional step toward understanding the detailed fluid mechanical behavior of the more complex physiological configurations seen clinically.
Self-sealing, Large Bore Arterial Punctures: A Counterintuitive New
Phenomenon
Authors: Roeder Blayne A. , Babbs Charles F. , Schoenlein William E. , Kokini Klod , Sadeghi Farshid 
Published: October 2002

Abstract
The human femoral artery can bleed dangerously following the removal of a catheter during cardiac catheterization. In this study, a modified technique of needle insertion, simply inserting the needle bevel-down instead of the standard bevel-up approach, was tested as a means to reduce bleeding after catheter removal. Large bore needle punctures were made in surgically exposed arteries of anesthetized pigs using either a standard technique (45 degree approach, bevel up) or a modified technique (25 degree approach, bevel down). For half the punctures, topical phenylephrine solution (1 mg/ml) was applied to the adventitia of the artery to cause constriction. Median bleeding rates were reduced from 81 to less than 1 ml/min/100 mmHg intraluminal pressure by the modified technique with application of phenylephrine. In most cases zero bleeding, that is self-sealing, of the arteries occurred. It is postulated that a flap-valve of tissue created by the modified technique produced this self-sealing behavior. Sophisticated modeling studies are needed to fully understand this new phenomenon.
Mucosal Folding in Biologic Vessels
Authors: Hrousis Constantine A. , Wiggs Barry J. R. , Drazen Jeffrey M. , Parks David M. , Kamm Roger D. 
Published: October 2002

Abstract
A two-layer model is used to simulate the mechanical behavior of an airway or other biological vessel under external compressive stress or smooth muscle constriction sufficient to cause longitudinal mucosal buckling. Analytic and finite element numerical methods are used to examine the onset of buckling. Post-buckling solutions are obtained by finite element analysis, then verified with large-scale physical model experiments. The two-layer model provides insight into how the stiffness of a vessel wall changes due to changes in the geometry and intrinsic material stiffnesses of the wall components. Specifically, it predicts that the number of mucosal folds in the buckled state is diminished most by increased thickness of the inner collagen-rich layer, and relatively little by increased thickness of the outer submucosal layer. An increase in the ratio of the inner to outer material stiffnesses causes an intermediate reduction in the number of folds. Results are cast in a simple form that can easily be used to predict buckling in a variety of vessels. The model quantitatively confirms that an increase in the thickness of the inner layer leads to a reduction in the number of mucosal folds, and further, that this can lead to increased vessel collapse at high levels of smooth muscle constriction.
Multi-axial Spine Biomechanical Testing System with Speckle
Displacement Instrumentation
Authors: Chung S. M. , Teoh S. H. , Tsai K. T. , Sin K. K. 
Published: October 2002

Abstract
This paper reports on the design and development of a multi-axis (up to 6 axes) mechanical tester for spinal research and testing. The developed spine tester allowed true motion to be simulated on a specimen in pure or combined modes. To demonstrate the capability of the new tester, flexural stiffness properties of sheep lumbar motion segments were evaluated together with a non-contact speckle displacement measurement system. The flexural stiffness of the specimens was measured and compared under constrained and non-constrained testing conditions; with relieving of shear forces (non-constrained), it was found that the specimen behaved in a ‘stiffer’ manner.
Antibiotic Resistance Genes and
Salmonella
Genomic Island 1 in
Salmonella enterica
Serovar Typhimurium Isolated in Italy
Authors: Carattoli Alessandra , Filetici Emma , Villa Laura , Dionisi Anna Maria , Ricci Antonia , Luzzi Ida 
Published: October 2002

ABSTRACT

Fifty-four epidemiologically unrelated multidrug-resistant
Salmonella enterica
serovar Typhimurium isolates, collected between 1992 and 2000 in Italy, were analyzed for the presence of integrons. Strains were also tested for
Salmonella
genomic island 1 (SGI1), carrying antibiotic resistance genes in DT104 strains. A complete SGI1 was found in the majority of the DT104 strains. Two DT104 strains, showing resistance to streptomycin-spectinomycin and sulfonamides, carried a partially deleted SGI1 lacking the

flo
st

,
tetR
, and
tetA
genes, conferring chloramphenicol-florfenicol and tetracycline resistance, and the integron harboring the
pse-1
gene cassette, conferring ampicillin resistance. The presence of SGI1 was also observed in serovar Typhimurium strains belonging to other phage types, suggesting either the potential mobility of this genomic island or changes in the phage-related phenotype of DT104 strains.
Characterization of a Self-Transferable Plasmid from
Salmonella enterica
Serotype Typhimurium Clinical Isolates Carrying Two Integron-Borne Gene Cassettes Together with Virulence and Drug Resistance Genes
Authors: Guerra Beatriz , Soto Sara , Helmuth Reiner , Mendoza M. Carmen 
Published: October 2002

ABSTRACT

An unusual self-transferable virulence-resistance plasmid (pUO-
St
VR2) was found in nine multidrug-resistant (ACSSuT phenotype)
Salmonella enterica
serotype Typhimurium clinical isolates that were assigned to four different phage types and a single and distinctive
Xba
I pulsed-field gel electrophoresis profile. pUO-
St
VR2 is an IncFII plasmid of about 140 kb in length carrying the
spvA
,
spvB
, and
spvC
(
Salmonella
plasmid virulence) and
rck
(resistance to complement killing) genes. It also carries the
oxa1/aadA1a
(ampicillin resistance and streptomycin-spectinomycin resistance) gene cassette configuration located within a class 1 integron with
qacEΔ1/sul1
(ammonium antiseptics resistance and sulfadiazine resistance); the transposon genes
merA
,
tnpA
, and
tnpR
(mercury resistance, transposase, and resolvase of Tn
21
, respectively); and the
catA1
(chloramphenicol resistance) and
tet
(B) (tetracycline resistance) genes. The insertion of resistance genes into a
Salmonella
virulence plasmid constitutes a new and interesting example of plasmid evolution and presents a serious public health problem.
Surveillance for Antiviral-Agent-Resistant Herpes Simplex Virus in the General Population with Recurrent Herpes Labialis
Authors: Bacon Teresa H. , Boon Ron J. , Schultz Margaret , Hodges-Savola Cheryl 
Published: October 2002

ABSTRACT
In a general population survey in the United States, the prevalence of antiviral-agent-resistant herpes simplex virus was very low among more than 1,000 isolates from individuals with an episode of recurrent herpes labialis not treated with topical antiviral agents. Two isolates had borderline resistance to acyclovir (0.2%), and all were susceptible to penciclovir.
Role of
Pseudomonas putida
Indoleacetic Acid in Development of the Host Plant Root System
Authors: Patten Cheryl L. , Glick Bernard R. 
Published: October 2002

ABSTRACT

Many plant-associated bacteria synthesize the phytohormone indoleacetic acid (IAA). While IAA produced by phytopathogenic bacteria, mainly by the indoleacetamide pathway, has been implicated in the induction of plant tumors, it is not clear whether IAA synthesized by beneficial bacteria, usually via the indolepyruvic acid pathway, is involved in plant growth promotion. To determine whether bacterial IAA enhances root development in host plants, the
ipdc
gene that encodes indolepyruvate decarboxylase, a key enzyme in the indolepyruvic acid pathway, was isolated from the plant growth-promoting bacterium
Pseudomonas putida
GR12-2 and an IAA-deficient mutant constructed by insertional mutagenesis. The canola seedling primary roots from seeds treated with wild-type
P. putida
GR12-2 were on average 35 to 50% longer than the roots from seeds treated with the IAA-deficient mutant and the roots from uninoculated seeds. In addition, exposing mung bean cuttings to high levels of IAA by soaking them in a suspension of the wild-type strain stimulated the formation of many, very small, adventitious roots. Formation of fewer roots was stimulated by treatment with the IAA-deficient mutant. These results suggest that bacterial IAA plays a major role in the development of the host plant root system.
Accumulation of Inorganic Polyphosphate in
phoU
Mutants of
Escherichia coli
and
Synechocystis
sp. Strain PCC6803
Authors: Morohoshi Tomohiro , Maruo Tatsuya , Shirai Yoko , Kato Junichi , Ikeda Tsukasa , Takiguchi Noboru , Ohtake Hisao , Kuroda Akio 
Published: October 2002

ABSTRACT

The biological process for phosphate (P
i
) removal is based on the use of bacteria capable of accumulating inorganic polyphosphate (polyP). We obtained
Escherichia coli
mutants which accumulate a large amount of polyP. The polyP accumulation in these mutants was ascribed to a mutation of the
phoU
gene that encodes a negative regulator of the P
i
regulon. Insertional inactivation of the
phoU
gene also elevated the intracellular level of polyP in
Synechocystis
sp. strain PCC6803. The mutant could remove fourfold more P
i
from the medium than the wild-type strain removed.
Acute Septic Arthritis
Authors: Shirtliff Mark E. , Mader Jon T. 
Published: October 2002

SUMMARYAcute septic arthritis may develop as a result of hematogenous seeding, direct introduction, or extension from a contiguous focus of infection. The pathogenesis of acute septic arthritis is multifactorial and depends on the interaction of the host immune response and the adherence factors, toxins, and immunoavoidance strategies of the invading pathogen.Neisseria gonorrhoeaeand Staphylococcus aureus are used in discussing the host-pathogen interaction in the pathogenesis of acute septic arthritis. While diagnosis rests on isolation of the bacterial species from synovial fluid samples, patient history, clinical presentation, laboratory findings, and imaging studies are also important. Acute nongonococcal septic arthritis is a medical emergency that can lead to significant morbidity and mortality. Therefore, prompt recognition, rapid and aggressive antimicrobial therapy, and surgical treatment are critical to ensuring a good prognosis. Even with prompt diagnosis and treatment, high mortality and morbidity rates still occur. In contrast, gonococcal arthritis is often successfully treated with antimicrobial therapy alone and demonstrates a very low rate of complications and an excellent prognosis for full return of normal joint function. In the case of prosthetic joint infections, the hardware must be eventually removed by a two-stage revision in order to cure the infection.
Atopic Dermatitis and Fungi
Authors: Faergemann Jan 
Published: October 2002

SUMMARYAtopic dermatitis (AD) is a chronic, itching, inflammatory skin disease which is associated with asthma and/or hay fever and a familial occurrence of these conditions. Genetic factors are important in the development of AD, but the exact hereditary pathway is still unknown. Dry skin and the weakened barrier function in patients with AD is very important for the patient's reactions to irritants and other external trigger factors including microorganisms. The standard treatments are topical corticosteroids, topical immunomodulating agents, and emollients. If AD cannot be controlled by this type of treatment, systemic immunomodulating agents may be used. UVB, UVA, or psoralen-UVA may also be used for widespread severe lesions. However, some patients do not respond to these standard treatment, and then it is important to consider the role of microorganisms, house dust mites or food. The role of the Malassezia yeasts in AD, especially AD located to the head and neck region, is now documented in several papers. There are also several papers indicating the role of Candida as an aggravating factor in AD. Patients with AD also develop chronic dermatophyte infections more easily, and patients with AD and chronic dermatophyte infections may show improvement in their AD when treated with antifungal drugs.
Evolutionary and Historical Aspects of the Burden of Malaria
Authors: Carter Richard , Mendis Kamini N. 
Published: October 2002

SUMMARYMalaria is among the oldest of diseases. In one form or another, it has infected and affected our ancestors since long before the origin of the human line. During our recent evolution, its influence has probably been greater than that of any other infectious agent. Here we attempt to trace the forms and impacts of malaria from a distant past through historical times to the present. In the last sections, we review the current burdens of malaria across the world and discuss present-day approaches to its management. Only by following, or attempting to follow, malaria throughout its evolution and history can we understand its character and so be better prepared for our future management of this ancient ill.
History of Human Parasitology
Authors: Cox F. E. G. 
Published: October 2002

SUMMARYHumans are hosts to nearly 300 species of parasitic worms and over 70 species of protozoa, some derived from our primate ancestors and some acquired from the animals we have domesticated or come in contact with during our relatively short history on Earth. Our knowledge of parasitic infections extends into antiquity, and descriptions of parasites and parasitic infections are found in the earliest writings and have been confirmed by the finding of parasites in archaeological material. The systematic study of parasites began with the rejection of the theory of spontaneous generation and the promulgation of the germ theory. Thereafter, the history of human parasitology proceeded along two lines, the discovery of a parasite and its subsequent association with disease and the recognition of a disease and the subsequent discovery that it was caused by a parasite. This review is concerned with the major helminth and protozoan infections of humans: ascariasis, trichinosis, strongyloidiasis, dracunculiasis, lymphatic filariasis, loasis, onchocerciasis, schistosomiasis, cestodiasis, paragonimiasis, clonorchiasis, opisthorchiasis, amoebiasis, giardiasis, African trypanosomiasis, South American trypanosomiasis, leishmaniasis, malaria, toxoplasmosis, cryptosporidiosis, cyclosporiasis, and microsporidiosis.
What Happened to the Streptococci: Overview of Taxonomic and Nomenclature Changes
Authors: Facklam Richard 
Published: October 2002

SUMMARY

Since the division of the
Streptococcus genus
into enterococci, lactococci, and streptococci in 1984, many changes in the nomenclature and taxonomy of the
Streptococcus genus
have taken place. The application of genetic comparisons has improved the proper classification of the different species. The Lancefield system of serogrouping the streptococci by the expression of beta-hemolysis on blood agar plates is still very useful for the identification of streptococci for patient management. The Lancefield grouping system cannot be used in itself for accurate identification of specific beta-hemolytic species, but it can be a useful part of the identification procedure. Except for identification of the “
Streptococcus bovis
group” of species and
Streptococcus suis
, Lancefield grouping is of little value in identification of the non-beta-hemolytic streptococci and related genera. In fact, identification of the non-beta-hemolytic species is problematic for conventional as well as commercially available identification procedures. A combination of conventional tests and specific chromogenic tests suggested by several investigators is presented and discussed. Tables are included that suggest tests and procedures to guide investigators attempting to identify all the species.
Tularemia
Authors: Ellis Jill , Oyston Petra C. F. , Green Michael , Titball Richard W. 
Published: October 2002

SUMMARYFrancisella tularensis is the etiological agent of tularemia, a serious and occasionally fatal disease of humans and animals. In humans, ulceroglandular tularemia is the most common form of the disease and is usually a consequence of a bite from an arthropod vector which has previously fed on an infected animal. The pneumonic form of the disease occurs rarely but is the likely form of the disease should this bacterium be used as a bioterrorism agent. The diagnosis of disease is not straightforward.F. tularensisis difficult to culture, and the handling of this bacterium poses a significant risk of infection to laboratory personnel. Enzyme-linked immunosorbent assay- and PCR-based methods have been used to detect bacteria in clinical samples, but these methods have not been adequately evaluated for the diagnosis of pneumonic tularemia. Little is known about the virulence mechanisms ofF. tularensis, though there is a large body of evidence indicating that it is an intracellular pathogen, surviving mainly in macrophages. An unlicensed live attenuated vaccine is available, which does appear to offer protection against ulceroglandular and pneumonic tularemia. Although an improved vaccine against tularemia is highly desirable, attempts to devise such a vaccine have been limited by the inability to construct defined allelic replacement mutants and by the lack of information on the mechanisms of virulence ofF. tularensis. In the absence of a licensed vaccine, aminoglycoside antibiotics play a key role in the prevention and treatment of tularemia.
Interactions among Strategies Associated with Bacterial Infection: Pathogenicity, Epidemicity, and Antibiotic Resistance
Authors: Martínez José L. , Baquero Fernando 
Published: October 2002

SUMMARYInfections have been the major cause of disease throughout the history of human populations. With the introduction of antibiotics, it was thought that this problem should disappear. However, bacteria have been able to evolve to become antibiotic resistant. Nowadays, a proficient pathogen must be virulent, epidemic, and resistant to antibiotics. Analysis of the interplay among these features of bacterial populations is needed to predict the future of infectious diseases. In this regard, we have reviewed the genetic linkage of antibiotic resistance and bacterial virulence in the same genetic determinants as well as the cross talk between antibiotic resistance and virulence regulatory circuits with the aim of understanding the effect of acquisition of resistance on bacterial virulence. We also discuss the possibility that antibiotic resistance and bacterial virulence might prevail as linked phenotypes in the future. The novel situation brought about by the worldwide use of antibiotics is undoubtedly changing bacterial populations. These changes might alter the properties of not only bacterial pathogens, but also the normal host microbiota. The evolutionary consequences of the release of antibiotics into the environment are largely unknown, but most probably restoration of the microbiota from the preantibiotic era is beyond our current abilities.