bluuebunny/crossref_metadata_2025_split huggingface dataset:
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.
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

ABSTRACT

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

ABSTRACT

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

ABSTRACT

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

ABSTRACTKlebsiella 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

ABSTRACT

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

ABSTRACTSequencing 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

ABSTRACTWe 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

ABSTRACT

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

ABSTRACTPeptide 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

ABSTRACT

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

ABSTRACT

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.