bluuebunny/crossref_metadata_2025_split huggingface dataset:
Molecular screens for inner ear genes
Authors: Heller Stefan 
Published: October 2002

AbstractIdentification of the genes that encode proteins that are important for proper function of specific inner ear cell types is central to our understanding of the molecular basis of hearing and balance. Whereas the combination of electrophysiology and biophysics has resulted in an exquisite understanding of inner ear function, little is known about the proteins that confer these properties at the cellular level. Furthermore, the genes that control inner ear development, susceptibility to wear and tear, regeneration from damage, and age‐related degeneration, are largely unknown. This review discusses tools that have been developed during the past few years to address this imbalance between a thorough physiologic characterization of inner ear function and a detailed understanding at a molecular level of the proteins involved in these functions. Creation of inner ear cDNA libraries has laid the foundation for the discovery of genes that are specifically expressed by cell types of the inner ear and that encode proteins that are important for molecular processes in these cells. In conjunction with expressed sequence tag database analysis, cDNA subtraction, and DNA arrays, functionally important genes, whose specific expression patterns are usually verified by gene expression analysis, can be identified. Discussion of these techniques takes into account the specific characteristics of the inner ear in relation to its study using molecular biological approaches. © 2002 Wiley Periodicals, Inc. J Neurobiol 53: 265–275, 2002
Melanization ofCryptococcus neoformansandHistoplasma capsulatumReduces Their Susceptibilities to Amphotericin B and Caspofungin
Authors: van Duin David , Casadevall Arturo , Nosanchuk Joshua D. 
Published: October 2002

ABSTRACTThe fungal pathogensCryptococcus neoformansandHistoplasma capsulatumproduce melanin-like pigments in the presence ofl-dopa in vitro and during mammalian infection. We investigated whether melanization affected the susceptibilities of the fungi to amphotericin B, caspofungin, fluconazole, itraconazole, or flucytosine (5FC). Using the standard macrodilution MIC protocol (the M27A protocol) of the National Committee for Clinical Laboratory Standards for yeast, we found no difference in the susceptibilities of melanized and nonmelanizedC. neoformansandH. capsulatumisolates. Killing assays demonstrated that melanization reduced the susceptibilities of both fungi to amphotericin B and caspofungin. Laccase-deficientC. neoformanscells grown withl-dopa were significantly more susceptible than congenic melanin-producing yeast to killing by amphotericin B or caspofungin. Preincubation of amphotericin B or caspofungin with melanins decreased their antifungal activities. Elemental analysis of melanins incubated with amphotericin B or caspofungin revealed an alteration in the C:N ratios of the melanins, which indicated binding of these drugs by the melanins. In contrast, incubation of fluconazole, itraconazole, or 5FC with melanins did not significantly affect the antifungal efficacies of the drugs or the chemical composition of the melanins. The results suggest a potential explanation for the inefficacy of caspofungin againstC. neoformansin vivo, despite activity in vitro. Furthermore, the results indicate that fungal melanins protectC. neoformansandH. capsulatumfrom the activities of amphotericin B and caspofungin and that this protection is not demonstrable by standard broth macrodilution assays.
Evaluation of Differential Gene Expression in Fluconazole-Susceptible and -Resistant Isolates of
Candida albicans
by cDNA Microarray Analysis
Authors: Rogers P. David , Barker Katherine S. 
Published: October 2002

ABSTRACT

The opportunistic fungal pathogen
Candida albicans
is the major causative agent of oropharyngeal candidiasis (OPC) in AIDS. The development of azoles, such as fluconazole, for the treatment of OPC has proven effective except in cases where
C. albicans
develops resistance to fluconazole during the course of treatment. In the present study, we used microarray technology to examine differences in gene expression from a fluconazole-susceptible and a fluconazole-resistant well-characterized, clinically obtained matched set of
C. albicans
isolates to identify genes which are differentially expressed in association with azole resistance. Among genes found to be differentially expressed were those involved in amino acid and carbohydrate metabolism; cell stress, cell wall maintenance; lipid, fatty acid, and sterol metabolism; and small molecule transport. In addition to
CDR1
, which has previously been demonstrated to be associated with azole resistance, the drug resistance gene
RTA3
, the ergosterol biosynthesis gene
ERG2
, and the cell stress genes
CRD2
,
GPX1
, and
IFD5
were found to be upregulated. Several genes, such as the mitochondrial aldehyde dehydrogenase gene
ALD5
, the glycosylphosphatidylinositol synthesis gene
GPI1
, and the iron transport genes
FET34
and
FTR2
were found to be downregulated. Further study of these differentially regulated genes is warranted to evaluate how they may be involved in azole resistance. In addition to these novel findings, we demonstrate the utility of microarray analysis for studying the molecular mechanisms of drug resistance in pathogenic organisms.
In Vivo Toxicity, Pharmacokinetics, and Anti-Human Immunodeficiency Virus Activity of Stavudine-5′-(p-Bromophenyl Methoxyalaninyl Phosphate) (Stampidine) in Mice
Authors: Uckun Fatih M. , Qazi Sanjive , Pendergrass Sharon , Lisowski Elizabeth , Waurzyniak Barbara , Chen Chun-Lin , Venkatachalam T. K. 
Published: October 2002

ABSTRACTWe have evaluated the clinical potential of stavudine-5′-(p-bromophenyl methoxyalaninyl phosphate(stampidine [STAMP]), a novel aryl phosphate derivative of stavudine, as a new anti-human immunodeficiency virus (anti-HIV) agent, by examining its acute, subacute, and chronic toxicity profile in mice as well as by testing its antiviral activity in a surrogate human peripheral blood lymphocyte (Hu-PBL)-SCID mouse model of human AIDS. STAMP was very well tolerated in BALB/c and CD-1 mice, without any detectable acute or subacute toxicity at single intraperitoneal or oral bolus doses as high as 500 mg/kg of body weight. Notably, daily administration of STAMP intraperitoneally or orally for up to 8 consecutive weeks was not associated with any detectable toxicity at cumulative dose levels as high as 6.4 g/kg. Micromolar concentrations of the active STAMP metabolite in plasma were rapidly achieved and maintained for more than 4 h after parenteral as well as oral administration of a nontoxic 100-mg/kg bolus dose of STAMP. In accordance with its favorable pharmacokinetic profile and in vitro potency, STAMP exhibited dose-dependent and potent in vivo anti-HIV activity in Hu-PBL-SCID mice against a genotypically and phenotypically nucleoside analog reverse transcriptase inhibitor (NRTI)-resistant clinical HIV type 1 (HIV-1) isolate (BR/92/019; D67N, L214F, T215D, K219Q) at nontoxic dose levels. The remarkable in vivo safety and potency of STAMP warrants the further development of this promising new antiretroviral agent for possible clinical use in patients harboring NRTI-resistant HIV-1.
Antimicrobial Therapy forBacillus anthracis-Induced Polymicrobial Infection in60Co γ-Irradiated Mice
Authors: Elliott Thomas B. , Brook Itzhak , Harding Rita A. , Bouhaouala S. Samy , Shoemaker Michael O. , Knudson Gregory B. 
Published: October 2002

ABSTRACTChallenge with both nonlethal ionizing radiation and toxigenicBacillus anthracisspores increases the rate of mortality from a mixed bacterial infection. If biological weapons, such asB. anthracisspores, and nuclear weapons were used together, casualties could be more severe than they would be from the use of either weapon alone. We previously discovered that a polymicrobial infection developed in B6D2F1/J mice after nonlethal (7-Gy)60Co γ irradiation and intratracheal challenge withB. anthracisSterne spores 4 days after irradiation. In this present study, we investigated the survival of mice and the response of the polymicrobial infection during the course of antimicrobial therapy with penicillin G procaine, ofloxacin, trovafloxacin, or gatifloxacin. Survival was prolonged, but not ensured, when the mice were treated with either broad-spectrum ofloxacin or narrow-spectrum penicillin G for 7 days beginning 6 or 24 h after challenge. Survival was not prolonged when therapy was delayed more than 24 h after challenge. When these two antimicrobial agents were given for 21 days, the survival rate was increased from 0% for the controls to 38 to 63% after therapy. Therapy with trovafloxacin or gatifloxacin reduced the incidence of mixed infection and improved the rate of survival to 95% (trovafloxacin) or 79% (gatifloxacin), whereas the rate of survival for the controls was 5%. We conclude that the mixed infection induced byB. anthracisin irradiated mice complicates effective therapy with a single antimicrobial agent. To limit mortality following nonlethal irradiation and challenge withB. anthracisspores, antimicrobial therapy needs to be initiated within a few hours after challenge and continued for up to 21 days.
Chromosome-Encoded β-Lactamases TUS-1 and MUS-1 from
Myroides odoratus
and
Myroides odoratimimus
(Formerly
Flavobacterium odoratum
), New Members of the Lineage of Molecular Subclass B1 Metalloenzymes
Authors: Mammeri Hedi , Bellais Samuel , Nordmann Patrice 
Published: October 2002

ABSTRACT

Myroides odoratus
and
Myroides odoratimimus
(formerly designated in a single species as
Flavobacterium odoratum
) are gram-negative aerobes and sources of nosocomial infections in humans. They have variable susceptibility to β-lactams and a decreased susceptibility to carbapenems. Using genomic DNAs of
M. odoratus
CIP 103105 and
M. odoratimimus
CIP 103073 reference strains, shotgun cloning of β-lactamase genes was performed, followed by protein expression in
Escherichia coli
. The deduced amino acid sequences of these β-lactamase genes revealed that TUS-1 and MUS-1 from
M. odoratus
CIP 103105 and
M. odoratimimus
CIP 103073, respectively, shared 73% amino acid identity. Mature proteins TUS-1 and MUS-1, with pI values of 7.8 and 5.2, respectively, had relative molecular masses of ca. 26 kDa. These β-lactamases are members of the subclass B1 of metallo-β-lactamases and are distantly related to other metalloenzymes, being most closely related to IND-1 from
Chryseobacterium indologenes
(42% amino acid identity). However, phylogenic analysis showed that TUS-1 and MUS-1 belong to the same phylogenic lineage of subclass B1 enzymes that groups the subclass B1 β-lactamases of
Flavobacterium
species. Kinetic parameters of purified β-lactamases TUS-1 and MUS-1 detailed their hydrolysis spectra, which encompass most β-lactams except aztreonam. β-Lactamases TUS-1 and MUS-1 were classified in functional subgroup 3a of metalloenzymes. This work further characterizes chromosome-encoded metalloenzymes from
Flavobacteriaceae
species that explain at least part of their intrinsic resistance to β-lactams.
Nonmyeloablative transplantation with or without alemtuzumab: comparison between 2 prospective studies in patients with lymphoproliferative disorders
Authors: Pérez-Simón José A. , Kottaridis Panagiotis D. , Martino Rodrigo , Craddock Charles , Caballero Dolores , Chopra Raj , Garcı́a-Conde Javier , Milligan Don W. , Schey Stephen , Urbano-Ispizua Alvaro , Parker Anne , Leon Angel , Yong Kwee , Sureda Ana , Hunter Ann , Sierra Jordi , Goldstone Anthony H. , Linch David C. , Miguel Jesus F. San , Mackinnon Stephen 
Published: October 2002

Abstract
Although nonmyeloablative conditioning regimen transplantations (NMTs) induce engraftment of allogeneic stem cells with a low spectrum of toxicity, graft-versus-host disease (GVHD) remains a significant cause of morbidity and mortality. In vivo T-cell depletion, using alemtuzumab, has been shown to reduce the incidence of GVHD. However, this type of maneuver, although reducing GVHD, may have an adverse impact on disease response, because NMTs exhibit their antitumor activity by relying on a graft-versus-malignancy effect. To explore the efficacy of alemtuzumab compared with methotrexate (MTX) for GVHD prophylaxis, we have compared the results in 129 recipients of a sibling NMT enrolled in 2 prospective studies for chronic lymphoproliferative disorders. Both NMTs were based on the same combination of fludarabine and melphalan, but the United Kingdom regimen (group A) used cyclosporin A plus alemtuzumab, whereas the Spanish regimen (group B) used cyclosporin A plus MTX for GVHD prophylaxis. Patients receiving alemtuzumab had a higher incidence of cytomegalovirus (CMV) reactivation (85% versus 24%,P < .001) and a significantly lower incidence of acute GVHD (21.7% versus 45.1%, P = .006) and chronic GVHD (5% versus 66.7%, P < .001). Twenty-one percent of patients in group A and 67.5% in group B had complete or partial responses 3 months after transplantation (P < .001). Eighteen patients in group A received donor lymphocyte infusions (DLIs) to achieve disease control. At last follow-up there was no difference in disease status between the groups with 71% versus 67.5% (P = .43) of patients showing complete or partial responses in groups A and B, respectively. No significant differences were observed in event-free or overall survival between the 2 groups. In conclusion, alemtuzumab significantly reduced GVHD but its use was associated with a higher incidence of CMV reactivation. Patients receiving alemtuzumab often required DLIs to achieve similar tumor control but the incidence of GVHD was not significantly increased after DLI.
Mice expressing a neutrophil elastase mutation derived from patients with severe congenital neutropenia have normal granulopoiesis
Authors: Grenda David S. , Johnson Sonja E. , Mayer Jill R. , McLemore Morgan L. , Benson Kathleen F. , Horwitz Marshall , Link Daniel C. 
Published: October 2002

AbstractSevere congenital neutropenia (SCN) is a syndrome characterized by an isolated block in granulocytic differentiation and an increased risk of developing acute myeloid leukemia (AML). Recent studies have demonstrated that the majority of patients with SCN and cyclic neutropenia, a related disorder characterized by periodic oscillations in the number of circulating neutrophils, have heterozygous germline mutations in the ELA2 gene encoding neutrophil elastase (NE). To test the hypothesis that these mutations are causative for SCN, we generated transgenic mice carrying a targeted mutation of theirEla2 gene (“V72M”) reproducing a mutation found in 2 unrelated patients with SCN, one of whom developed AML. Expression of mutant NE mRNA and enzymatically active protein was confirmed. Mice heterozygous and homozygous for the V72M allele have normal numbers of circulating neutrophils, and no accumulation of myeloid precursors in the bone marrow was observed. Serial blood analysis found no evidence of cycling in any of the major hematopoietic lineages. Rates of apoptosis following cytokine deprivation were similar in wild-type and mutant neutrophils, as were the frequency and cytokine responsiveness of myeloid progenitors. The stress granulopoiesis response, as measured by neutrophil recovery after cyclophosphamide-induced myelosuppression, was normal. To define the leukemogenic potential of V72M NE, a tumor watch was established. To date, no cases of leukemia have been detected. Collectively, these data suggest that expression of V72M NE is not sufficient to induce an SCN phenotype or leukemia in mice.
Chronic graft-versus-host disease after allogeneic blood stem cell transplantation: long-term results of a randomized study
Authors: Mohty Mohamad , Kuentz Mathieu , Michallet Mauricette , Bourhis Jean-Henri , Milpied Noël , Sutton Laurent , Jouet Jean-Pierre , Attal Michel , Bordigoni Pierre , Cahn Jean-Yves , Boiron Jean-Michel , Blaise Didier 
Published: October 2002

AbstractThe use of peripheral blood stem cells (PBSCs) is rapidly growing in the allogeneic transplantation setting as an alternative to bone marrow (BM). We previously reported a higher incidence of chronic graft-versus-host disease (cGVHD) associated with allogeneic PBSC transplantation in a randomized trial. In this follow-up report, we analyzed the evolution of cGVHD in the patients (n = 101) enrolled on this study. At a median follow-up of 45 months (range, 31-57 months), we found that the 3-year cumulative incidence of cGVHD was 65% (95% confidence interval [CI] 51%-78%) in the PBSC group and 36% (95% CI 23%-49%) in the BM group (P = .004). We also found that extensive cGVHD was more frequent in the PBSC group (44% [95% CI 30%-58%] vs 17% [95% CI 7%-27%];P = .004). The prevalence of cGVHD was always higher in the PBSC arm. Ocular involvement was more frequent in PBSC recipients (P = .02). Cutaneous and liver involvement was similar among BM and PBSC recipients. Chronic GVHD required multiple courses of immunosuppressive therapy in addition to cyclosporine and corticosteroids during longer periods (P = .03). Altogether, this translated into longer periods of hospitalization after transplantation in the PBSC group (P = .04). Finally, we also confirm that cGVHD after PBSC transplantation is associated with an antileukemic effect that is at least as potent as after BM. However, to date, this has not translated into a survival difference, possibly due to the early-stage leukemic status of these patients or to the relatively small size of the study population.
Binding of Sp1 to the proximal promoter links constitutive expression of the human uPA gene and invasive potential of PC3 cells
Authors: Ibañez-Tallon Inés , Ferrai Carmelo , Longobardi Elena , Facetti Ileana , Blasi Francesco , Crippa Massimo P. 
Published: October 2002

AbstractActivated transcription of the urokinase-type plasminogen activator (uPA) gene depends on the enhancer, located approximately 2 kb from the start of transcription. The proximal promoter, driving basal transcription, contains a GC-/GA-rich sequence immediately upstream of the TATA box. We have investigated the role played by this element in the transcription of the uPA gene in HeLa and PC3 cells, which do not express or constitutively express the gene, respectively. This region binds either Sp1 or Sp3, as monomers or multimers, but not a combination of the 2 proteins. The more efficient binding of Sp1 to the proximal promoter in PC3 cells is correlated to its phosphorylation state. Polymerase chain reaction (PCR)–coupled, chromatin immunoprecipitation experiments with anti-Sp1 antibodies indeed show an enrichment of proximal promoter sequences in PC3 cells and support the observed difference in transcription levels from proximal promoter constructs in HeLa versus PC3 cells. Furthermore, overexpression of Sp1 increases transcription from the reporter construct in HeLa cells, whereas in PC3 cells, overexpression of Sp3 does not reduce transcription from the same construct, indicating that the Sp1/Sp3 balance cannot be shifted. We conclude that the GC-/GA-rich element of the uPA regulatory region is an independent functional element, regulated by Sp family proteins. Phosphorylation of Sp1 determines the presence in vivo and the functionality of this element in PC3 cells. Thus, the cellular context determines the relevance of the GC-/GA-rich region in uPA gene transcription, which contributes to constitutive gene expression, related, in turn, to the invasive phenotype.
Quercetin 3,7-dimethyl ether: a vasorelaxant flavonoid isolated from Croton schiedeanus Schlecht
Authors: Guerrero M F , Puebla P , Carrón R , Martín M L , Román L San 
Published: October 2002

Abstract
The vasorelaxant profile of quercetin 3,7-dimethyl ether, a flavonoid isolated from Croton schiedeanus Schlecht (Euphorbiaceae), was assessed in aortic rings isolated from Wistar rats. To gain insight into its structure-activity relationship, we compared this substance with quercetin 3,4′,7- trimethyl ether (ayanin), another flavonoid isolated from this plant, quercetin 3,3′,4′,7-tetramethyl ether, a flavonoid synthesized by us, and quercetin. In addition we examined the interaction of quercetin 3,7-dimethyl ether with the nitric oxide (NO)/cyclic guanosine monophosphate (cGMP) pathway. According to their pEC50 values (concentration producing a 50% inhibition of the maximal contractile response) to phenylephrine-induced precontraction in rat isolated aorta, the potency order was quercetin 3,7-dimethyl ether &gt; quercetin &gt; quercetin 3,4′,7-trimethyl ether &gt; quercetin 3,3′,4′,7-tetramethyl ether (4.70 ± 0.18; 3.96 ± 0.07; 3.64 ± 0.02; 3.11 ± 0.16). The relaxant effect of quercetin 3,7-dimethyl ether was significantly decreased by the removal of endothelium as well as by methylene blue, an inhibitor of guanylyl cyclase, and by NG-nitro-L-arginine methyl ester hydrochloride (L-NAME), an NO-synthase inhibitor. Therefore, quercetin 3,7-dimethyl ether has a NO/cGMP pathway-related profile, with increased vasorelaxant activity due to hydroxylation at positions 3 and 4 of the B ring. In addition, methylation at positions 3 and 7 with respect to quercetin of the C and A rings, respectively, seems to further enhance the vasorelaxant activity of quercetin 3,7-dimethyl ether.
Salivary gland choristoma of the middle ear: case treated with KTP laser
Authors: Supiyaphun Pakpoom , Snidvongs Kornkiat , Shuangshoti Shanob 
Published: October 2002

Salivary gland choristoma of the middle ear is rare. It consists of non-malignant, non-growing, normal salivary gland tissue in the middle ear. It is a developmental abnormality that occurs around the proximal part of the second branchial arch before the fourth month of intrauterine life.The authors found the 25th recorded case in our centre and another 24 reported cases from a review of the literature between 1961 and 1999. Intratympanic salivary gland choristoma frequently occurs during the first and second decades of life and with a female preponderance (56 per cent). Nearly all the patients (96 per cent) in our review presented with a hearing loss, that had begun since birth, in infancy, or during childhood. Tinnitus (28 per cent), and serous otitis media (24 per cent) were also commonly present. One case complained of otorrhoea. Intratympanic and extratympanic anomalies were found in 96.2 per cent and 34.6 per cent of cases respectively. Of these anomalies, ossicular chain (88.5 per cent), facial nerve (65.4 per cent), middle-ear muscles (30.8 per cent) and labyrinthine windows (23 per cent) were the four most common sites. Therefore, salivary gland choristoma may represent a manifestation of a congenital ear anomaly.Diagnosis of salivary gland choristoma is generally not documented pre-operatively, but is based on surgical biopsy and histopathological investigations. Treatment of this rare lesion depends on the size, location and extent of the mass, degree of anatomical abnormality and expertise of the surgeon. In difficult cases where the mass is attached to the dehiscent or inferiorly placed facial nerve, only biopsy is recommended. However, complete surgical removal is advocated for a mass that is easy to remove. KTP laser use via a 200 micron fibreoptic light carrier can facilitate removal especially in cases with ossicular chain involvement.