bluuebunny/crossref_metadata_2025 huggingface dataset:
Nutritional Formula Enhanced Immune Function and Reduced Days of Symptoms of Upper Respiratory Tract Infection in Seniors
Authors: Langkamp‐henken Bobbi , Bender Bradley S. , Gardner Elizabeth M. , Herrlinger‐garcia Kelli A. , Kelley Michael J. , Murasko Donna M. , Schaller Joseph P. , Stechmiller Joyce K. , Thomas Debra J. , Wood Steven M.
Published: December 2003

Objectives: To assess whether an experimental nutritional formula, given as a supplement, would reduce days of symptoms of upper respiratory tract infection (URTI) and affect antibody and lymphocyte proliferative responses to influenza vaccine.

Design:

A prospective, randomized, double‐blind, controlled trial was conducted between October 1999 and April 2000.

Setting: Assisted‐ and independent‐living facilities in North Central Florida.

Participants: Sixty‐six individuals, aged 65 and older.

Intervention: Subjects received 8 oz/d of an experimental formula containing antioxidants, zinc, selenium, fermentable oligosaccharides, and structured triacylglycerol or an isoenergetic, isonitrogenous control formula for 183 days.

Measurements: Subjects recorded daily symptoms of URTI. Antibody titers and lymphocyte proliferation to three influenza vaccine components were measured on Days 57 and 183.

Results: Eighteen subjects in the control group and 16 subjects in the experimental group consumed an average of 7 ounces of formula daily and completed the 183‐day study. Median days of symptoms of URTI were 3 (range 0–69, total days=156) and 0 (range 0–49, total days=78) for the control and experimental groups, respectively (P= .049). On Day 57, seven of 17 (41%) subjects in the control group and 13 of 15 (87%) subjects in the experimental group achieved a fourfold or greater increase in serum antibody titer to A/Beijing (P=.012). Lymphocyte proliferation to influenza vaccine components was greater in the experimental (median=1,365 cpm, range=0–14,955 cpm) than the control group (median=136 cpm, range=0–4,270 cpm) (P=.013).

Conclusion: Subjects consuming an experimental nutritional formula experienced enhanced immune function and fewer days of URTI symptoms.
Can a Short Period of Micronutrient Supplementation in Older Institutionalized People Improve Response to Influenza Vaccine? A Randomized, Controlled Trial
Authors: Allsup Stephen J. , Shenkin Alan , Gosney Margot A. , Taylor Stephen , Taylor William , Hammond Margaret , Zambon Maria C.
Published: December 2003

Objectives: To test the hypothesis that a micronutrient supplement can improve seroconversion after influenza immunization in older institutionalized people.

Design: Randomized, double‐blind, placebo‐controlled study.

Setting: Nursing and residential homes in Liverpool, United Kingdom.

Participants: One hundred sixty‐four residents aged 60 and older from 31 homes were initially randomized; of these, 119 (72.6%) completed the study.

Intervention: Participants were randomized to receive a micronutrient supplement providing the reference nutrient intake for all vitamins and trace elements or identical placebo. Tablets were taken over an 8‐week period during September and October 2000; influenza vaccine was administered 4 weeks after their commencement.

Measurements: The hemagglutination‐inhibiting antibody response as defined by a fourfold or greater titer rise over 4 weeks and assessed separately for each of the three antigens contained in the 2000/2001 influenza vaccine (A/New Caledonia/20/99 (H1N1), A/Moscow/10/99 (H3N2), B/Beijing/184/93 (B)).

Results: Despite a significant increase in serum concentrations of vitamins A, C, D3, E, folate, and selenium in the supplemented group, there was no significant difference between groups (supplemented vs placebo, respectively) in the proportion of participants seroconverting to H1N1 (41% vs 49%, P=.374), H3N2 (49% vs 58%, P=.343), or B (41% vs 40%, P=.944).

Conclusion: A micronutrient supplement providing the reference nutrient intake administered over 8 weeks had no beneficial effect on antibody response to influenza vaccine in older people living in long‐term care.
Barriers to Pneumococcal and Influenza Vaccination in Older Community‐Dwelling Adults (2000–2001)
Authors: Nowalk Mary Patricia , Zimmerman Richard K. , Shen Shunhua , Jewell Ilene K. , Raymund Mahlon
Published: December 2003

Objectives: To identify facilitators of and barriers to vaccination in patients from a range of socioeconomic levels.

Design: A survey was conducted in 2001 using computer‐assisted telephone interviewing.

Setting: Patients from inner‐city health centers and suburban practices were interviewed.

Participants: Inclusion criteria were aged 66 and older and an office visit after September 30, 1998.

Measurements: Self‐reported influenza and pneumococcal vaccination status and facilitating conditions, attitudes, social influences, and perceived consequences from the Triandis model were assessed.

Results: Overall, 557 interviews were completed with 775 eligible patients (72%). Patients who reported having received pneumococcal vaccine more frequently believed that their physicians recommended the vaccine than did the unvaccinated (97% vs 49%; P=.001). This was also true for influenza vaccine (99% vs 80%; P<.001). More unvaccinated patients than vaccinated patients felt that obtaining either vaccine was more trouble than it is worth (pneumococcal 19% vs 1%; P=.04, influenza 20% vs 1%; P=.004). The vaccinated were more likely to be willing to obtain the influenza and pneumococcal vaccines at the same time (pneumococcal 91% vs 59%; P=.002, influenza 91% vs 55%; P=.014).

Conclusion: Physicians should take every opportunity to recommend vaccination to their eligible adult patients. Offering influenza and pneumococcal vaccines at the same visit is an acceptable means to ensure that adults are fully vaccinated.
The Effect of Equipment Usage and Residual Task Difficulty on Use of Personal Assistance, Days in Bed, and Nursing Home Placement
Authors: Taylor Donald H. , Hoenig Helen
Published: December 2003

Objectives: To determine whether residual difficulty in functioning in spite of equipment use is linked with increased use of personal assistance.

Design: Longitudinal. Two waves of the Asset and Health Dynamics Among the Oldest Old (AHEAD) database were used to test the effect of residual difficulty on hours of personal assistance and bed days at Wave 1 on hours of personal assistance, bed days, and nursing home placement at Waves 1 and 2.

Setting: A nationally representative setting of community‐dwelling persons aged 70 and older and their spouses, regardless of age at Wave 1 AHEAD. There was movement of some respondents into nursing homes by the Wave 2 interview.

Participants: Respondents to the AHEAD survey, N=8,222 at Wave 1.

Measurements: The dependent variables were hours of personal assistance in the month before the AHEAD survey (Waves 1 and 2), number of days in month before the survey in which the person did not get out of bed (Waves 1 and 2), and residence in a nursing home at Wave 2. The key explanatory variable was a mutually exclusive (four category) variable that specified whether there was residual difficulty (yes/no) in indoor mobility in spite of using equipment to aid specifically with indoor mobility. The four‐category variable was defined by the four categories created by a cross‐tabulation of equipment use (yes/no) and difficulty with indoor mobility (yes/no). A similar four‐category variable was also defined for transferring in the home.

Results: In cross section, equipment users with residual difficulty reported more hours of personal assistance in the case of indoor mobility impairment and were more likely to have some hours of personal assistance than those without residual difficulty with indoor mobility and transferring. Longitudinally, those with residual difficulty at Wave 1 were more likely to need some personal assistance hours at Wave 2 (odds ratio=1.67, 95% confidence interval= 1.23–2.26 for indoor mobility). For transferring, those with residual difficulty had 43 more hours of personal assistance per month (P=.001) than those for whom equipment resolved their disability. Residual disability was linked to more bed days for users of indoor mobility and transferring equipment, but it was not predictive of nursing home placement by Wave 2.

Conclusion: Equipment for indoor mobility or transfers apparently resolves difficulty for some users of the equipment but not for others. Residual task difficulty in spite of equipment for indoor mobility and transferring is linked with worse outcomes, including increased dependency on personal assistance and more days in bed. This shows that more attention is needed to determine whether equipment prescribed is appropriate for a patient's difficulty and that follow‐up assessment is crucial after equipment is prescribed.
Efficacy, Safety, and Tolerability of Sertraline in Patients with Late‐Life Depression and Comorbid Medical Illness
Authors: Sheikh Javaid I. , Cassidy Erin L. , Doraiswamy P. Murali , Salomon Ronald M. , Hornig Mady , Holland Peter J. , Mandel Francine S. , Clary Cathryn M. , Burt Tal
Published: December 2003

Objectives: To report on the efficacy, safety, and tolerability of sertraline in the treatment of elderly depres‐sed patients with and without comorbid medical illness.

Setting: Multicenter.

Design: Randomized, double‐blind, placebo‐controlled study.

Participants: A total of 752 patients aged 60 and older with diagnosis of major depressive disorder according to Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, diagnosis.

Measurements: Outcome measures included the 17‐item Hamilton Depression Scale (HAMD); the Clinical Global Depression—Severity/Improvement (CGI‐S/CGI‐I); efficacy and safety/adverse event assessments; Quality of Life, Enjoyment, and Satisfaction Questionnaire; and the Medical Outcomes Study 36‐Item Short‐Form Health Status Survey.

Results: In the overall sample, sertraline was superior to placebo on all three primary outcome measures, HAMD, and overall clinical severity and change (CGI‐S/CGI‐I). Furthermore, therapeutic response to sertraline was comparable in those with or without medical comorbidity, and there were no treatment‐by–comorbidity group interactions. Sertraline was also associated with a faster time to response than placebo in the comorbid group (P<.006). Sertraline‐treated patients in the comorbid group had similar adverse events and discontinuations when compared to those in the noncomorbid group.

Conclusion: Sertraline was efficacious in reducing depressive symptomatology, regardless of the presence of comorbid medical illness. Sertraline was safe and well tolerated by patients with or without medical illness.
The Short‐Term Effect of Interdisciplinary Medication Review on Function and Cost in Ambulatory Elderly People
Authors: Williams Mark E. , Pulliam Charles C. , Hunter Rebecca , Johnson Ted M. , Owens Justine E. , Kincaid Jean , Porter Carol , Koch Gary
Published: December 2003

Objectives: To determine whether a medication review by a specialized team would promote regimen changes in elders taking multiple medications and to measure the effect of regimen changes on monthly cost and functioning.

Design: A randomized‐controlled trial.

Setting: Health center ambulatory clinic.

Participants: Community‐dwelling older adults taking five or more medications were assessed at baseline and 6 weeks. A medication‐change intervention group of 57 elders was compared with a control group of 76 elder adults.

Intervention: The primary intervention was a comprehensive review and recommended modification of a patient's medication regimen. Changes were endorsed by each patient's primary physician and discussed with each patient.

Measurements: Measures were the Timed Manual Performance Test, Physical Performance Test, Functional Reach Assessment, subtests from the Wechsler Adult Intelligence Scale, a modified Randt Memory Test, the Center for Epidemiological Studies—Depression Scale, the Self‐Rating Anxiety Scale, and the Rand 36‐item Health Survey 1.0. Comorbidity was determined using the International Classification of Diseases, Ninth Revision, Clinical Modification. Medication usage was determined using brown bag review.

Results: Intervention subjects decreased their medications by an average of 1.5 drugs. No differences in functioning were observed between groups. Intervention subjects saved an average $26.92 per month in wholesale medication costs; control subjects saved $6.75 per month (P<.006).

Conclusion: Although the intervention significantly reduced the medications taken and monthly cost, most patients were resistant to reducing medications to the recommended level. Further study is needed to understand patient resistance to reducing adverse polypharmacy and to devise better strategies for addressing this important problem in geriatric health. Greater focus on prescriber behavior is recommended.
Sexual Healthcare Needs of Women Aged 65 and Older
Authors: Nusbaum Margaret R. H. , Singh Amrit R. , Pyles Amanda A.
Published: December 2003

Objectives: To compare prevalence and type of sexual concerns and interest in and experience with discussing these concerns with physicians for women younger than 65 and 65 and older.

Design: Cross‐sectional survey.

Setting: Departments of Family Practice and Obstetrics and Gynecology at Madigan Army Medical Center, Tacoma, Washington.

Participants: Of 1,480 women seeking routine gynecological care, 964 (65%) responded; 163 (17%) were aged 65 and older.

Measurements: Self‐reported sexual concerns and interest in and experience with discussing these concerns with their physicians.

Results: Older women had a similar number of sexual concerns as younger women and were more likely to be concerned about their partner's sexual difficulties. Older women were less likely to have ever had the topic of sexual health raised during healthcare visits. Even though these women were more likely to report youthful‐appearing physicians as hindering the topic of sexual health, the majority indicated that they would have discussed their concerns had the physician raised the topic and were interested in a follow‐up appointment to do so.

Conclusion: Although the types of sexual concerns vary in frequency, women aged 65 and older have a similar number of sexual concerns as younger women. Older women want physicians to inquire about their sexual health. This discussion should include inquiries about their partner's sexual functioning. To overcome age as a barrier to this discussion, younger physicians should be particularly attentive to initiating the topic of sexual health.
Underlying Mechanisms of Impaired Visceral Pain Perception in Older People
Authors: Moore Alan R. , Clinch David
Published: December 2003

There is increasing recognition that aging can have a profound effect on the presentation of illness. Older patients with diseases of visceral organs are much more likely than younger adults to present atypically. Examples are the frequent absence of pain in older patients with conditions such as myocardial infarction, peptic ulcer disease, and pneumothorax.

Recent developments have helped elucidate the complex processes involved in signaling information from the effects of noxious stimuli on visceral organs, but understanding of why older patients with visceral disease are more likely to present without pain is still rudimentary. Much of the previous experimental evidence on age‐related differences relates to somatic rather than visceral sources of pain. As a result, it may not have direct comparability with transmission of information on visceral damage or noxious stimulation.

This article reviews the published pathophysiological data on sensory transmission from visceral organs. Where possible, this is correlated with other published clinical studies on age‐related differences in visceral pain perception. Areas in which experimental evidence is absent are also highlighted. Finally suggestions are made as to how newer experimental and neuroimaging techniques may help to increase understanding of this complex subject and its resulting clinical applicability.
The Shadow Negotiation and the Interest‐Based Approach at Kaiser Permanente
Authors: Kolb Deborah M.
Published: December 2003

As interesting and significant as the Kaiser Permanente case is in and of itself, there were many parallel negotiations that took place just below the surface of the overt negotiations. The author focuses on this “shadow negotiation,” exploring a series of strategic moves that took place in the case, enabling the parties to craft their negotiation process. These shadow negotiations involved positioning moves, process moves, power moves, and appreciative moves. The parallel shadow negotiation was a significant factor in the success of the Kaiser Permanente negotiations.
Using a Negotiations Lens to Examine the American Catholic Church's Response to the Clergy Sex‐Abuse Scandal
Authors: Cedrone Michael J.
Published: December 2003

The explosive clergy sex‐abuse scandal forced the Roman Catholic Church members, clergy, and church leaders to renegotiate the kind of dialogue that they will have with each other. As the full dimensions of the clergy sex‐abuse scandal in Boston came to light during 2002, the public response of Cardinal Law and other church leaders to victims, and groups of clergy and laity was often adversarial. While some of the Cardinal's actions were consistent with his stated goal of protecting children, his behavior revealed the unstated goal of protecting the institution of the church, its leadership structure, and ultimately, his own position. By contrast, Bishop Wilton Gregory's November 2002 presidential address to the United States Conference of Catholic Bishops employed a more complex model of negotiation: he articulated broad goals to attract the support of his various audiences and while postponing discussion of the controversies that will attend efforts to reach those goals. Ultimately, the future of relations among church members, clergy, and church leaders will depend on how successfully these groups can negotiate church membership.
Cross‐Cultural Issues in a Life Sciences Company
Authors: Chaisiri Judith , Flax Jodi
Published: December 2003

Cross‐cultural issues transcend the boundaries of nations and native tongues. Traditionally considered in national or religious contexts, cross‐cultural issues also occur in the corporate environment, especially those environments specializing in high technology. The life sciences industry employs many different professional cultures including scientists, engineers, computer programmers and management and, due to the highly specialized needs within this industry, success is reliant on the interaction between the groups. Scientists and management in particular come from completely different cultures: the academic world (Ph.D.) and the business world (MBA). While speaking the same native language, these two cultures are separated by cultural norms and biases. Bridging the gap between these differences can be difficult but not impossible. This article explores the origins of tension between scientists and management and seeks to offer a path to more open, productive communication.
An Object-Based Software Package for Interactive Control System Design and Analysis
Authors: Zhu Yong , Chen Bo , Cheng Harry H.
Published: December 2003

Ch is an embeddable C/C++ interpreter. It was developed to allow software developers to use one language, anywhere and everywhere, for any programming task. Ch supports C99, a latest C standard ratified in 1999, and contains salient features for two and three dimensional plotting and numerical computing for applications in engineering and science. Developed in Ch, Ch Control System Toolkit provides a control class with member functions for object-based interactive modeling, analysis, and design of linear time-invariant control systems. The software package, available for downloading on the web, has been widely used in industry to solve practical engineering problems and in universities for instructional improvement. The design and implementation of Ch Control System Toolkit are described in this paper. Two application examples of control system design and analysis using Ch Control System Toolkit demonstrate its power and simplicity.
Surface Reconstruction of Freeform Objects Based on Multiresolution Volumetric Method
Authors: Azernikov Sergei , Miropolsky Alex , Fischer Anath
Published: December 2003

Recently developed 3D scanning devices are capable of capturing point clouds, as well as additional information, such as normals and texture. This paper describes a new and fast reverse engineering method for creating a 3D computerized model from data captured by such contemporary 3D scanning devices. The proposed method aggregates large-scale 3D scanned data into an extended Hierarchical Space Decomposition Model (HSDM) based on Octree data structure. This model can represent both an object’s boundary surface and its interior volume. The HSDM enables data reduction, while preserving sharp geometrical features and object topology. As a result the execution time of the reconstruction process is significantly reduced. Moreover, the proposed model naturally allows multiresolution surface reconstruction, represented by a mesh with regular properties. Based on the proposed volumetric model, the surface reconstruction process becomes more robust and stable with respect to sampling noise.
Tolerance-based Variations in Solid Modeling
Authors: Moroni G. , Polini W.
Published: December 2003

Information on tolerances and attributes of mechanical parts and assemblies is crucial for many activities in a product’s life cycle. Tolerance design is a complex task because many factors (functional, technological and economical) should be considered. It is an iterative process, starting from a first tolerances assignment and ending with the definition of their optimal values. Once all tolerances have been assigned to each part of an assembly, tolerance analysis is performed. This stage aim is to evaluate if the combined effects of the assigned tolerances let the design requirements be met. Then, feasible and economical aspects are considered on the basis of both available processes and cost evaluations. The whole tolerance design stage is usually defined as tolerance synthesis. The focus of this work is the discussion of the algorithms to model the geometrical variations, of each part of an assembly, allowed by geometric tolerances. This involves the change of the boundary nominal representation of a part face on the basis of the assigned dimensional and geometric tolerances. At present, the developed algorithms are able to simulate flatness, location and orientation. The modified parts, generated by tolerance simulation, may be used to evaluate the overall assemblability and, then, to verify the assembly functional requirements.
Efficient Computation of A Simplified Medial Axis
Authors: Foskey Mark , Lin Ming C. , Manocha Dinesh
Published: December 2003

The computation and application of the medial axis have been limited because of its instability and algebraic complexity. In this paper, we use a simplification of the medial axis, the θ-SMA, that is parameterized by a separation angle formed by the vectors connecting a point on the medial axis to the closest points on the boundary. We formally characterize the degree of simplification of the θ-SMA as a function of θ. We present a fast algorithm to compute an approximation of the θ-SMA. It relies on computation of the distance field and its gradient using graphics hardware. The complexity of the algorithm varies based on resolution of the volume discretization and is a linear function of the input size. We have applied this algorithm to approximate the SMA of complex models composed of tens or hundreds of thousands of triangles. On a 2-GHz PC, its running time varies from a few seconds, for a model consisting of hundreds of triangles, to minutes for highly complex models.
Collision Prediction
Authors: Kim Byungmoon , Rossignac Jarek
Published: December 2003

The prediction of collisions amongst N rigid objects may be reduced to a series of computations of the time to first contact for all pairs of objects. Simple enclosing bounds and hierarchical partitions of the space-time domain are often used to avoid testing object-pairs that clearly will not collide. When the remaining pairs involve only polyhedra under straight-line translation, the exact computation of the collision time and of the contacts requires only solving for intersections between linear geometries. When a pair is subject to a more general relative motion, such a direct collision prediction calculation may be intractable. The popular brute force collision detection strategy of executing the motion for a series of small time steps and of checking for static interferences after each step is often computationally prohibitive. We propose instead a less expensive collision prediction strategy, where we approximate the relative motion between pairs of objects by a sequence of screw motion segments, each defined by the relative position and orientation of the two objects at the beginning and at the end of the segment. We reduce the computation of the exact collision time and of the corresponding face/vertex and edge/edge collision points to the numeric extraction of the roots of simple univariate analytic functions. Furthermore, we propose a series of simple rejection tests, which exploit the particularity of the screw motion to immediately decide that some objects do not collide or to speed-up the prediction of collisions by about 30%, avoiding on average 3/4 of the root-finding queries even when the object actually collide.
Scale-Space Representation and Classification of 3D Models
Authors: Bespalov and Dmitriy , Shokoufandeh Ali , Regli William C. , Sun Wei
Published: December 2003

This paper presents a framework for shape matching and classification through scale-space decomposition of 3D models. The algorithm is based on recent developments in efficient hierarchical decomposition of a point distribution in metric space p,d using its spectral properties. Through spectral decomposition, we reduce the problem of matching to that of computing a mapping and distance measure between vertex-labeled rooted trees. We use a dynamic programming scheme to compute distances between trees corresponding to solid models. Empirical evaluation of the algorithm on an extensive set of 3D matching trials demonstrates both robustness and efficiency of the overall approach. Lastly, a technique for comparing shape matchers and classifiers is introduced and the scale-space method is compared with six other known shape matching algorithms.
Oral Delivery of Meglumine Antimoniate-β-Cyclodextrin Complex for Treatment of Leishmaniasis
Authors: Demicheli Cynthia , Ochoa Rosemary , da Silva José B. B. , Falcão Camila A. B. , Rossi-Bergmann Bartira , de Melo Alan L. , Sinisterra Ruben D. , Frézard Frédéric
Published: December 2003

The need for daily parenteral administration represents one of the most serious limitations in the clinical use of pentavalent antimonials against leishmaniasis. In this work, we investigated the ability of β-cyclodextrin to enhance the oral absorption of antimony and to promote the oral efficacy of meglumine antimoniate against experimental cutaneous leishmaniasis. The occurrence of interactions between β-cyclodextrin and meglumine antimoniate was demonstrated through the changes induced in the spin lattice relaxation times of protons in both compounds. When free and complexed meglumine antimoniate were given orally to Swiss mice, plasma antimony levels were found to be about three times higher for the meglumine antimoniate-β-cyclodextrin complex than for the free drug. Antileishmanial efficacy was evaluated in BALB/c mice experimentally infected with
Leishmania amazonensis
. Animals treated daily with the complex (32 mg of Sb/kg of body weight) by the oral route developed significantly smaller lesions than those treated with meglumine antimoniate (120 mg of Sb/kg) and control animals (treated with saline). The effectiveness of the complex given orally was equivalent to that of meglumine antimoniate given intraperitoneally at a twofold-higher antimony dose. The antileishmanial efficacy of the complex was confirmed by the significantly lower parasite load in the lesions of treated animals than in saline-treated controls. This work reports for the first time the effectiveness of an oral formulation for pentavalent antimonials.
In Vitro and In Vivo Activities of a Triterpenoid Saponin Extract (PX-6518) from the Plant
Maesa balansae
against Visceral
Leishmania
Species
Authors: Maes Louis , Berghe Dirk Vanden , Germonprez Nils , Quirijnen Ludo , Cos Paul , De Kimpe Norbert , Van Puyvelde Luc
Published: December 2003

The in vitro and in vivo activities of a mixture of six oleane triterpene saponins, recovered from the methanolic extract of the leaves of the Vietnamese plant
Maesa balansae
(PX-6518), were evaluated against drug-sensitive visceral
Leishmania
strains. The in vitro 50% inhibitory concentration (IC
50
) against intracellular
Leishmania infantum
amastigotes was 0.04 μg/ml. The cytotoxic concentrations causing 50% cell death (CC
50
s) were about 1 μg/ml in murine macrophage host cells and >32 μg/ml in human fibroblasts (MRC-5 cell line). Evaluation in the
Leishmania donovani
BALB/c mouse model indicated that a single subcutaneous administration of 0.4 mg/kg at 1 day after infection reduced liver amastigote burdens by about 95% in all treated animals. If treatment was delayed until 14 days after infection, a dose of 1.6 mg/kg of body weight was required to maintain the same level of activity. Single 250-mg/kg doses of sodium stibogluconate (Pentostam) 1 and 14 days after infection produced comparable efficacies. A single dose of PX-6518 at 2.5 mg/kg administered 5 days before infection was still 100% effective in preventing liver infection, suggesting a particularly long residual action. Spleen and bone marrow could not be cleared by PX-6518 nor sodium stibogluconate. PX-6518 did not show activity after oral dosing at up to 200 mg/kg for 5 days. This study concludes that triterpenoid saponins from
M. balansae
show promising in vitro and in vivo antileishmanial potential and can be considered as new lead structures in the search for novel antileishmanial drugs.
Molecular Basis of Intrinsic Macrolide Resistance in the
Mycobacterium tuberculosis
Complex
Authors: Buriánková Karolína , Doucet-Populaire Florence , Dorson Olivier , Gondran Anne , Ghnassia Jean-Claude , Weiser Jaroslav , Pernodet Jean-Luc
Published: December 2003

The intrinsic resistance of the
Mycobacterium tuberculosis
complex (MTC) to most antibiotics, including macrolides, is generally attributed to the low permeability of the mycobacterial cell wall. However, nontuberculous mycobacteria (NTM) are much more sensitive to macrolides than members of the MTC. A search for macrolide resistance determinants within the genome of
M. tuberculosis
revealed the presence of a sequence encoding a putative rRNA methyltransferase. The deduced protein is similar to Erm methyltransferases, which confer macrolide-lincosamide-streptogramin (MLS) resistance by methylation of 23S rRNA, and was named ErmMT. The corresponding gene,
ermMT
(
erm37
), is present in all members of the MTC but is absent in NTM species. Part of
ermMT
is deleted in some vaccine strains of
Mycobacterium bovis
BCG, such as the Pasteur strain, which lack the RD2 region. The Pasteur strain was susceptible to MLS antibiotics, whereas MTC species harboring the RD2 region were resistant to them. The expression of
ermMT
in the macrolide-sensitive
Mycobacterium smegmatis
and BCG Pasteur conferred MLS resistance. The resistance patterns and ribosomal affinity for erythromycin of
Mycobacterium
host strains expressing
ermMT
,
srmA
(monomethyltransferase from
Streptomyces ambofaciens
), and
ermE
(dimethyltransferase from
Saccharopolyspora erythraea
) were compared, and the ones conferred by ErmMT were similar to those conferred by SrmA, corresponding to the MLS type I phenotype. These results suggest that
ermMT
plays a major role in the intrinsic macrolide resistance of members of the MTC and could be the first example of a gene conferring resistance by target modification in mycobacteria.
Emergence of Oxacillinase-Mediated Resistance to Imipenem inKlebsiella pneumoniae
Authors: Poirel Laurent , Héritier Claire , Tolün Venus , Nordmann Patrice
Published: December 2003

Klebsiella pneumoniaestrain 11978 was isolated in Turkey in 2001 and was found to be resistant to all β-lactams, including carbapenems. Cloning and expression inEscherichia coliidentified five β-lactamases, including two novel oxacillinases. The β-lactamase OXA-48 hydrolyzed imipenem at a high level and was remotely related (less than 46% amino acid identity) to the other oxacillinases. It hydrolyzed penicillins and imipenem but not expanded-spectrum cephalosporins. TheblaOXA-48gene was plasmid encoded and not associated with an integron, in contrast to most of the oxacillinase genes. An insertion sequence, IS1999, was found immediately upstream ofblaOXA-48. Another plasmid that encoded a second oxacillinase gene,blaOXA-47, located inside a class 1 integron was identified inK. pneumoniae11978. OXA-47 had a narrow spectrum of hydrolysis activity and did not hydrolyze ceftazidime or imipenem, as is found for the β-lactamase (OXA-1) to which it is related. In addition, β-lactamases TEM-1 and SHV-2a were expressed from the sameK. pneumoniaeisolate. Analysis of the outer membrane proteins of this isolate revealed that it lacked a porin of ca. 36 kDa. Thus, the high-level resistance to β-lactams of this clinical isolate resulted from peculiar β-lactamases and modification of outer membrane proteins.
Five Additional Genes Are Involved in Clavulanic Acid Biosynthesis in
Streptomyces clavuligerus
Authors: Jensen S. E. , Paradkar A. S. , Mosher R. H. , Anders C. , Beatty P. H. , Brumlik M. J. , Griffin A. , Barton B.
Published: December 2003

An approximately 12.5-kbp region of DNA sequence from beyond the end of the previously described clavulanic acid gene cluster was analyzed and found to encode nine possible open reading frames (ORFs). Involvement of these ORFs in clavulanic acid biosynthesis was assessed by creating mutants with defects in each of the ORFs
. orf12
and
orf14
had been previously reported to be involved in clavulanic acid biosynthesis. Now five additional ORFs are shown to play a role, since their mutation results in a significant decrease or total absence of clavulanic acid production. Most of these newly described ORFs encode proteins with little similarity to others in the databases, and so their roles in clavulanic acid biosynthesis are unclear. Mutation of two of the ORFs,
orf15
and
orf16
, results in the accumulation of a new metabolite,
N
-acetylglycylclavaminic acid, in place of clavulanic acid.
orf18
and
orf19
encode apparent penicillin binding proteins, and while mutations in these genes have minimal effects on clavulanic acid production, their normal roles as cell wall biosynthetic enzymes and as targets for β-lactam antibiotics, together with their clustered location, suggest that they are part of the clavulanic acid gene cluster.
Constitutive Expression of a Chromosomal Class A (BJM Group 2) β-Lactamase inXanthomonas campestris
Authors: Weng Shu-Fen , Lin Juey-Wen , Chen Chih-Hung , Chen Yih-Yuan , Tseng Yi-Hsuan , Tseng Yi-Hsiung
Published: December 2003

Sequencing of the upstream region of the β-lactamase gene fromXanthomonas campestrispv. campestris 11 (blaXCC-1) revealed the cognateampR1gene (289 amino acids, 31 kDa). It runs divergently fromblaXCC-1with a 100-bp intergenic region (IG) containing partially overlapped promoters with structural features typical of thebla-ampRIG. The deduced AmpR1 protein shows significant identity in amino acid sequence and conserved motifs with AmpR proteins of other species, e.g., ofPseudomonas aeruginosa(58.2% amino acid identity). Results of insertional mutation, complementation tests, and β-lactamase assays suggested that expression ofblaXCC-1was constitutive and dependent on AmpR1. Fourblagenes and twoampRgenes are present in the fully sequencedX. campestrispv. campestris ATCC 33913 genome, with XCC3039 and XCC3040 considered the analogues ofblaXCC-1andampR1, respectively. AnampR1homologue was detected by Southern hybridization in the ampicillin-resistantXanthomonasstrains, which appear to express β-lactamase constitutively. Although the significance remains to be studied, constitutive expression of β-lactamase by a widespread bacterial genus raises environmental concerns regarding the dissemination of resistance genes.
Intracutaneous Distributions of Fluconazole, Itraconazole, and Griseofulvin in Guinea Pigs and Binding to Human Stratum Corneum
Authors: Sobue Satoshi , Sekiguchi Kaneo , Nabeshima Toshitaka
Published: December 2003

We have compared the distribution of fluconazole (FLC) with that of itraconazole (ITC) and griseofulvin (GRF) in the abdominal skin tissues after a single oral dose was administered to guinea pigs. The FLC concentrations in the stratum corneum reached a peak at 2 h after administration and were similar to those of ITC and higher than those of GRF in spite of the administration of a lower dose. GRF was eliminated from the stratum corneum faster than FLC and ITC. The FLC concentrations were also remarkably higher than those of ITC and GRF in the epidermis-cutis but lower in the subcutaneous fatty tissue. The distribution characteristics of each drug result from differences in their physicochemical properties. Following the administration of multiple doses, the FLC concentrations in the stratum corneum were highest in the abdominal skin tissues; those at 24 h after each administration increased gradually and were maintained at a level more than 10 times higher than that of the plasma concentrations. The FLC concentrations in the planta pedis stratum corneum and in the nail showed good dose proportionality and obvious accumulation and were 60 and 40 times as high as that in plasma on day 14. The extent of binding of FLC to human corneous keratin in vitro was about 10%, which is lower than those of ITC (94 to 97%) and GRF (36 to 38%). FLC, unlike ITC, therefore, is presumed to exist in the stratum corneum at high concentrations in an active nonbinding form. These excellent intracutaneous pharmacokinetic properties of FLC probably account in large part for the in vivo efficacy of FLC.
In Vitro Inhibition of the
Mycobacterium tuberculosis
β-Ketoacyl-Acyl Carrier Protein Reductase MabA by Isoniazid
Authors: Ducasse-Cabanot Stéphanie , Cohen-Gonsaud Martin , Marrakchi Hedia , Nguyen Michel , Zerbib Didier , Bernadou Jean , Daffé Mamadou , Labesse Gilles , Quémard Annaíik
Published: December 2003

The first-line specific antituberculous drug isoniazid inhibits the fatty acid elongation system (FAS) FAS-II involved in the biosynthesis of mycolic acids, which are major lipids of the mycobacterial envelope. The MabA protein that catalyzes the second step of the FAS-II elongation cycle is structurally and functionally related to the in vivo target of isoniazid, InhA, an NADH-dependent enoyl-acyl carrier protein reductase. The present work shows that the NADPH-dependent β-ketoacyl reduction activity of MabA is efficiently inhibited by isoniazid in vitro by a mechanism similar to that by which isoniazid inhibits InhA activity. It involves the formation of a covalent adduct between Mn
III
-activated isoniazid and the MabA cofactor. Liquid chromatography-mass spectrometry analyses revealed that the isonicotinoyl-NADP adduct has multiple chemical forms in dynamic equilibrium. Both kinetic experiments with isolated forms and purification of the enzyme-ligand complex strongly suggested that the molecules active against MabA activity are the oxidized derivative and a major cyclic form. Spectrofluorimetry showed that the adduct binds to the MabA active site. Modeling of the MabA-adduct complex predicted an interaction between the isonicotinoyl moiety of the inhibitor and Tyr185. This hypothesis was supported by the fact that a higher 50% inhibitory concentration of the adduct was measured for MabA Y185L than for the wild-type enzyme, while both proteins presented similar affinities for NADP
+
. The crystal structure of MabA Y185L that was solved showed that the substitution of Tyr185 induced no significant conformational change. The description of the first inhibitor of the β-ketoacyl reduction step of fatty acid biosynthesis should help in the design of new antituberculous drugs efficient against multidrug-resistant tubercle bacilli.
Peptide Deformylase Inhibitors as Antibacterial Agents: Identification of VRC3375, a Proline-3-Alkylsuccinyl Hydroxamate Derivative, by Using an Integrated Combinatorial and Medicinal Chemistry Approach
Authors: Chen D. , Hackbarth C. , Ni Z. J. , Wu C. , Wang W. , Jain R. , He Y. , Bracken K. , Weidmann B. , Patel D. V. , Trias J. , White R. J. , Yuan Z.
Published: December 2003

Peptide deformylase (PDF), a metallohydrolase essential for bacterial growth, is an attractive target for use in the discovery of novel antibiotics. Focused chelator-based chemical libraries were constructed and screened for inhibition of enzymatic activity, inhibition ofStaphylococcus aureusgrowth, and cytotoxicity. Positive compounds were selected based on the results of all three assays. VRC3375 [N-hydroxy-3-R-butyl-3-(2-S-(tert-butoxycarbonyl)-pyrrolidin-1-ylcarbonyl)propionamide] was identified as having the most favorable properties through an integrated combinatorial and medicinal chemistry effort. This compound is a potent PDF inhibitor with aKiof 0.24 nM against theEscherichia coliNi2+enzyme, possesses activity against gram-positive and gram-negative bacterial pathogens, and has a low cytotoxicity. Mechanistic experiments demonstrate that the compound inhibits bacterial growth through PDF inhibition. Pharmacokinetic studies of this drug in mice indicate that VRC3375 is orally bioavailable and rapidly distributed among various tissues. VRC3375 has in vivo activity againstS. aureusin a murine septicemia model, with 50% effective doses of 32, 17, and 21 mg/kg of body weight after dosing by intravenous (i.v.), subcutaneous (s.c.), and oral (p.o.) administration, respectively. In murine single-dose toxicity studies, no adverse effects were observed after dosing with more than 400 mg of VRC3375 per kg by i.v., p.o., or s.c. administration. The in vivo efficacy and low toxicity of VRC3375 suggest the potential for developing this class of compounds to be used in future antibacterial drugs.
Denaturing High-Performance Liquid Chromatography Detection of Ribosomal Mutations Conferring Macrolide Resistance in Gram-Positive Cocci
Authors: Canu Annie , Abbas Ahmed , Malbruny Brigitte , Sichel François , Leclercq Roland
Published: December 2003

Mutations in genes coding for L4 (
rplD
) or L22 (
rplV
) ribosomal proteins or in 23S rRNA (
rrl
gene) are reported as a cause of macrolide resistance in streptococci and staphylococci. This study was aimed at evaluating a denaturing high-performance liquid chromatography (DHPLC) technique as a rapid mutation screening method. Portions of these genes were amplified by PCR from total DNA of 48 strains of
Streptococcus pneumoniae
(
n
= 22),
Staphylococcus aureus
(
n
= 16),
Streptococcus pyogenes
(
n
= 6),
Streptococcus oralis
(
n
= 2), and group G streptococcus (
n
= 2). Thirty-seven of these strains were resistant to macrolides and harbored one or several mutations in one or two of the target genes, and 11 were susceptible. PCR products were analyzed by DHPLC. All mutations were detected, except a point mutation in a pneumococcal
rplD
gene. The method detected one mutated
rrl
copy out of six in
S. aureus
. This automated method is promising for screening of mutations involved in macrolide resistance in gram-positive cocci.
High-Throughput Screen for Inhibitors of Transglycosylase and/or Transpeptidase Activities of
Escherichia coli
Penicillin Binding Protein 1b
Authors: Chandrakala B. , Shandil Radha K. , Mehra Upasana , Ravishankar Sudha , Kaur Parvinder , Usha Veeraraghavan , Joe Bina , deSousa Sunita M.
Published: December 2003

Penicillin binding protein (PBP) 1b of
Escherichia coli
has both transglycosylase and transpeptidase activities, which are attractive targets for the discovery of new antibacterial agents. A high-throughput assay that detects inhibitors of the PBPs was described previously, but it cannot distinguish them from inhibitors of the MraY, MurG, and lipid pyrophosphorylase. We report on a method that distinguishes inhibitors of both activities of the PBPs from those of the other three enzymes. Radioactive peptidoglycan was synthesized by using
E. coli
membranes. Following termination of the reaction the products were analyzed in three ways. Wheat germ agglutinin (WGA)-coated scintillation proximity assay (SPA) beads were added to one set, and the same beads together with a detergent were added to a second set. Type A polyethylenimine-coated WGA-coated SPA beads were added to a third set. By comparison of the results of assays run in parallel under the first two conditions, inhibitors of the transpeptidase and transglycosylase could be distinguished from inhibitors of the other enzymes, as the inhibitors of the other enzymes showed similar inhibitory concentrations (IC
50
s) under both conditions but the inhibitors of the PBPs showed insignificant inhibition in the absence of detergent. Furthermore, comparison of the results of assays run under conditions two and three enabled the distinction of transpeptidase inhibitors. Penicillin and other β-lactams showed insignificant inhibition with type A beads compared with that shown with WGA-coated SPA beads plus detergent. However, inhibitors of the other four enzymes (tunicamycin, nisin, bacitracin, and moenomycin) showed similar IC
50
s under both conditions. We show that the main PBP being measured under these conditions is PBP 1b. This screen can be used to find novel transglycosylase or transpeptidase inhibitors.
Genetic and Biochemical Characterization of the Chromosomal Class A β-Lactamases of
Raoultella
(formerly
Klebsiella
)
planticola
and
Raoultella ornithinolytica
Authors: Walckenaer Estelle , Poirel Laurent , Leflon-Guibout Véronique , Nordmann Patrice , Nicolas-Chanoine Marie-Hélène
Published: December 2003

Enterobacterial strains of
Raoultella
spp. display a penicillinase-related β-lactam resistance pattern suggesting the presence of a chromosomal
bla
gene. From whole-cell DNA of
Raoultella planticola
strain ATCC 33531
T
and
Raoultella ornithinolytica
strain ATCC 31898
T
,
bla
genes were cloned and expressed into
Escherichia coli
. Each gene encoded an Ambler class A β-lactamase, named PLA-1 and ORN-1 for
R. planticola
and
R. ornithinolytica
, respectively. These β-lactamases (291 amino acids), with the same pI value of 7.8, had a shared amino acid identity of 94%, 37 to 47% identity with the majority of the chromosome-encoded class A β-lactamases previously described for
Enterobacteriaceae
, and 66 to 69% identity with the two β-lactamases LEN-1 and SHV-1 from
Klebsiella pneumoniae
. However, the highest identity percentage (69 to 71%) was found with the plasmid-mediated β-lactamase TEM-1. PLA-1, which displayed very strong hydrolytic activity against penicillins, also displayed significant hydrolytic activity against cefepime and, to a lesser extent, against cefotaxime and aztreonam, but there was no hydrolytic activity against ceftazidime. Such a substrate profile suggests that the
Raoultella
β-lactamases PLA-1 and ORN-1 should be classified into the group 2be of the β-lactamase classification of K. Bush, G. A. Jacoby, and A. A. Medeiros (Antimicrob. Agents Chemother.
39:
1211-1233, 1995). The highly homologous regions upstream of the
bla
PLA-1A
and
bla
ORN-1A
genes comprised a nucleotide sequence identical to the −35 region and another one very close to the −10 region of the
bla
LEN-1
gene. From now on, as the
bla
gene sequences of the most frequent
Raoultella
and
Klebsiella
species are available, the
bla
gene amplification method can be used to differentiate these species from each other, which the biochemical tests currently carried out in the clinical laboratory are unable to do.