bluuebunny/crossref_metadata_2025_split huggingface dataset:
Application of hydrotropy to transdermal formulations: hydrotropic solubilization of polyol fatty acid monoesters in water and enhancement effect on skin permeation of 5-FU
Authors: Takahashi Koichi , Komai Megumi , Kinoshita Natsumi , Nakamura Emi , Hou Xiao-Long , Takatani-Nakase Tomoka , Kawase Masaya 
Published: June 2011

Abstract

Objectives
A hydrotropic formulation containing a percutaneous enhancer was developed for the transdermal formulation of a water-soluble drug and the solubilizing mechanisms of a percutaneous enhancer in water by a hydrotropic agent were investigated. The enhancement effect was also compared with the hydrotropic formulation and the other formulations using ethanol, propylene glycol or mixed micelles.

Methods
Sodium salicylate (SA) and sodium benzoate (BA) were selected as hydrotropic agents, and polyol fatty acid ester (POFE) and 5-fluorouracil (5-FU) were selected as a percutaneous enhancer and a water-soluble drug, respectively. Near-infrared (NIR) spectrophotometric and 1H NMR spectroscopic studies were carried out to investigate the solubilizing mechanisms. The mean particle size in the hydrotropic formulation was measured. The in-vitro skin permeation of 5-FU and the accumulation in the skin of propylene glycol monocaprylate (PGMC), one of the monoesters of POFE, from the hydrotropic formulation or the other formulations were investigated by using Franz-type diffusion cell.

Key findings
The presence of SA and BA had a visible effect on the O–H stretching band of water in the NIR region. The surface tension of SA and BA aqueous solutions was found to decrease with an increase in SA or BA concentration. Although SA interacted with PGMC in the presence of water, it did not interact with PGMC in the absence of water. Mean particle size in a solution consisting of 5% (v/v) PGMC and 30% SA aqueous solution was approximately 14 nm. 1H NMR spectroscopic studies indicated that the hydrotropic salts formed aggregates with which PGMC interacted from the outside. The hydrotropic formulation prepared in this study enhanced skin permeation of 5-FU when compared with the other formulations.

Conclusions
SA and BA solubilized monoesters of POFE in water, and SA interacted with PGMC in water. The hydrotropic formulation prepared in this study significantly enhanced skin permeation of 5-FU compared with the other formulations. The results suggest that a hydrotropic formulation containing PGMC may be a useful transdermal formulation for water-soluble drugs.
Cytotoxic evaluation and induction of mitochondria-mediated apoptosis in human leukaemia HL-60 cells by Carissa spinarum stem isolate
Authors: Sehar Irum , Pal Harish Chandra , Shukla Sangeeta , Bhushan Shashi , Hamid Abid , Gupta Bishan Dutt , Saxena Ajit Kumar 
Published: June 2011

Abstract

Objective
To evaluate Carissa spinarum stem isolate for its anti-cancer therapeutic potential.

Methods
The n-butanol fraction of aqueous extract from Carissa spinarum stem was assessed for its cytotoxic and pro-apoptotic activity.

Key findings
We report for the first time the anti-cancer potential of C. spinarum stem aqueous extract (CSE) and its n-butanol fraction (CSF). Both inhibited cell proliferation of various human cancer cell lines in which leukaemia HL-60 cells treated with CSF showed maximum growth inhibition having an inhibitory concentration (IC50) value of 34.58 ± 0.91 µg/ml. In addition, CSF induced concentration-dependent apoptosis in HL-60 cells as measured by various end-points (e.g. Annexin V binding, DNA laddering, apoptotic body formation and an increase in hypodiploid subG0 DNA content). Moreover, persistent levels of reactive oxygen species caused translocation of Bax to mitochondria and Bcl-2 degradation, which led to loss of mitochondrial membrane potential and release of cytochrome c to the cytosol. These events were associated with significant activation of caspase-3, caspase-6 and caspase-9 leading to poly (ADP-ribose) polymerase cleavage.

Conclusion
All the above parameters revealed that CSF induced apoptosis through the mitochondrial dependent pathway in HL-60 cells.
Inhibition of ketamine-induced hyperlocomotion in mice by the essential oil of Alpinia zerumbet: possible involvement of an antioxidant effect
Authors: de Araújo Fernanda Yvelize Ramos , de Oliveira Gersilene Valente , Gomes Patrícia Xavier Lima , Soares Marília Almeida , Silva Maria Izabel Gomes , Carvalho André Férrer , de Moraes Manoel Odorico , de Moraes Maria Elisabete Amaral , Vasconcelos Silvânia Maria Mendes , Viana Glauce Socorro Barros , de Sousa Francisca Cléa Florenço , Macêdo Danielle Silveira 
Published: June 2011

Abstract

Objectives
The antipsychotic, hypnotic, myorelaxant and antioxidant effects of the essential oil of Alpinia zerumbet (EOAZ) were studied.

Methods
EOAZ (50, 100 and 200 mg/kg i.p.) was administered once to mice for the determination of antipsychotic activity (evaluated by ketamine-induced hyperlocomotion), hypnotic activity (induced by sodium pentobarbital, 40 mg/kg i.p.), motor coordination (rotarod test), antioxidant effects (determination of lipid peroxidation and GSH levels), as well as alterations in nitric oxide levels (determination of nitrite content).

Key findings
EOAZ at doses of 100 and 200 mg/kg prevented ketamine hyperlocomotion, as did haloperidol (0.2 mg/kg i.p). EOAZ at a dose of 200 mg/kg decreased sleep latency, while all doses increased sleeping time. There was no effect on motor coordination. The in-vitro antioxidant capacity of the oil caused a decrease in lipid peroxidation and increase in GSH levels. EOAZ also prevented the decrease in nitrite content caused by oxidative stress.

Conclusions
The results suggest antipsychotic and antioxidant effects for the EOAZ that may have promising efficacy for the treatment of schizophrenia.
Submerged Conidiation and Product Formation by Aspergillus niger at Low Specific Growth Rates Are Affected in Aerial Developmental Mutants
Authors: Jørgensen Thomas R. , Nielsen Kristian F. , Arentshorst Mark , Park JooHae , van den Hondel Cees A. , Frisvad Jens C. , Ram Arthur F. 
Published: June 2011

ABSTRACT

Exposure to an aerial environment or severe nutrient limitation induces asexual differentiation in filamentous fungi. Submerged cultivation of
Aspergillus niger
in carbon- and energy-limited retentostat cultures both induces and fuels conidiation. Physiological and transcriptomic analyses have revealed that this differentiation strongly affects product formation. Since conidiation is inherent in the aerial environment, we hypothesized that product formation near zero growth can be influenced by affecting differentiation or development of aerial hyphae in general. To investigate this idea, three developmental mutants (Δ
fwnA
,
scl-1
, and
scl-2
mutants) that have no apparent vegetative growth defects were cultured in maltose-limited retentostat cultures. The secondary-metabolite profile of the wild-type strain defined flavasperone, aurasperone B, tensidol B, and two so far uncharacterized compounds as associated with conidium formation, while fumonisins B
2
, B
4
, and B
6
were characteristic of early response to nutrient limitation by the vegetative mycelium. The developmental mutants responded differently to the severe substrate limitation, which resulted in distinct profiles of growth and product formation.
fwnA
encodes the polyketide synthase responsible for melanin biosynthesis during aerial differentiation, and we show that conidial melanin synthesis in submerged retentostat cultures and aurasperone B production are
fwnA
dependent. The
scl-1
and
scl-2
strains are two UV mutants generated in the Δ
fwnA
background that displayed reduced asexual conidiation and formed sclerotium-like structures on agar plates. The reduced conidiation phenotypes of the
scl-1
and
scl-2
strains are reflected in the retentostat cultivation and are accompanied by elimination or severely reduced accumulation of secondary metabolites and distinctly enhanced accumulation of extracellular protein. This investigation shows that submerged conidiation and product formation of a mitosporic fungus cultured at low specific growth rates can be fundamentally affected by interfering with the genetic program for differentiation of aerial hyphae, opening new perspectives for tailoring industrial performance.
Comparison of Innovative Molecular Approaches and Standard Spore Assays for Assessment of Surface Cleanliness
Authors: Cooper Moogega , La Duc Myron T. , Probst Alexander , Vaishampayan Parag , Stam Christina , Benardini James N. , Piceno Yvette M. , Andersen Gary L. , Venkateswaran Kasthuri 
Published: June 2011

ABSTRACT
A bacterial spore assay and a molecular DNA microarray method were compared for their ability to assess relative cleanliness in the context of bacterial abundance and diversity on spacecraft surfaces. Colony counts derived from the NASA standard spore assay were extremely low for spacecraft surfaces. However, the PhyloChip generation 3 (G3) DNA microarray resolved the genetic signatures of a highly diverse suite of microorganisms in the very same sample set. Samples completely devoid of cultivable spores were shown to harbor the DNA of more than 100 distinct microbial phylotypes. Furthermore, samples with higher numbers of cultivable spores did not necessarily give rise to a greater microbial diversity upon analysis with the DNA microarray. The findings of this study clearly demonstrated that there is not a statistically significant correlation between the cultivable spore counts obtained from a sample and the degree of bacterial diversity present. Based on these results, it can be stated that validated state-of-the-art molecular techniques, such as DNA microarrays, can be utilized in parallel with classical culture-based methods to further describe the cleanliness of spacecraft surfaces.
Marine Isolates of Trichoderma spp. as Potential Halotolerant Agents of Biological Control for Arid-Zone Agriculture
Authors: Gal-Hemed Inbal , Atanasova Lea , Komon-Zelazowska Monika , Druzhinina Irina S. , Viterbo Ada , Yarden Oded 
Published: June 2011

ABSTRACT

The scarcity of fresh water in the Mediterranean region necessitates the search for halotolerant agents of biological control of plant diseases that can be applied in arid-zone agriculture irrigated with saline water. Among 29
Trichoderma
strains previously isolated from Mediterranean
Psammocinia
sp. sponges, the greatest number of isolates belong to the
Trichoderma longibrachiatum
-
Hypocrea orientalis
species pair (9),
H. atroviridis/T. atroviride
(9), and
T. harzianum
species complex (7), all of which are known for high mycoparasitic potential. In addition, one isolate of
T. asperelloides
and two putative new species,
Trichoderma
sp. O.Y. 14707 and O.Y. 2407, from Longibrachiatum and Strictipilosa clades, respectively, have been identified.
In vitro
salinity assays showed that the ability to tolerate increasing osmotic pressure (halotolerance) is a strain- or clade-specific property rather than a feature of a species. Only a few isolates were found to be sensitive to increased salinity, while others either were halotolerant or even demonstrated improved growth in increasingly saline conditions.
In vitro
antibiosis assays revealed strong antagonistic activity toward phytopathogens due to the production of both soluble and volatile metabolites. Two marine-derived
Trichoderma
isolates, identified as
T. atroviride
and
T. asperelloides
, respectively, effectively reduced
Rhizoctonia solani
damping-off disease on beans and also induced defense responses in cucumber seedlings against
Pseudomonas syringae
pv. lachrimans. This is the first inclusive evaluation of marine fungi as potential biocontrol agents.
Identification and Characterization of UndA
HRCR-6
, an Outer Membrane Endecaheme
c
-Type Cytochrome of Shewanella sp. Strain HRCR-6
Authors: Shi Liang , Belchik Sara M. , Wang Zheming , Kennedy David W. , Dohnalkova Alice C. , Marshall Matthew J. , Zachara John M. , Fredrickson James K. 
Published: June 2011

ABSTRACT

UndA
HRCR-6
was identified from the metal-reducing bacterium
Shewanella
sp. strain HRCR-6. Both
in vivo
and
in vitro
characterization results indicate that UndA
HRCR-6
is an outer membrane endecaheme
c
-type cytochrome and probably has a key functional role in the extracellular reduction of iron [Fe(III)] oxides and uranium [U(VI)] by
Shewanella
sp. HRCR-6.
Natural Competence and Recombination in the Plant Pathogen Xylella fastidiosa
Authors: Kung Stephanie H. , Almeida Rodrigo P. P. 
Published: June 2011

ABSTRACT

Homologous recombination is one of many forces contributing to the diversity, adaptation, and emergence of pathogens. For naturally competent bacteria, transformation is one possible route for the acquisition of novel genetic material. This study demonstrates that
Xylella fastidiosa
, a generalist bacterial plant pathogen responsible for many emerging plant diseases, is naturally competent and able to homologously recombine exogenous DNA into its genome. Several factors that affect transformation and recombination efficiencies, such as nutrient availability, growth stage, and methylation of transforming DNA, were identified. Recombination was observed in at least one out of every 10
6
cells when exogenous plasmid DNA was supplied and one out of every 10
7
cells when different strains were grown together
in vitro
. Based on previous genomic studies and experimental data presented here, there is mounting evidence that recombination can occur at relatively high rates and could play a large role in shaping the genetic diversity of
X. fastidiosa
.
Interface of Candida albicans Biofilm Matrix-Associated Drug Resistance and Cell Wall Integrity Regulation
Authors: Nett Jeniel E. , Sanchez Hiram , Cain Michael T. , Ross Kelly M. , Andes David R. 
Published: June 2011

ABSTRACT

Candida albicans
frequently infects medical devices by growing as a biofilm, i.e., a community of adherent organisms entrenched in an extracellular matrix. During biofilm growth,
Candida
spp. acquire the ability to resist high concentrations of antifungal drugs. One recently recognized biofilm resistance mechanism involves drug sequestration by matrix β-1,3 glucan. Using a candidate gene approach, we investigated potential
C. albicans
β-1,3-glucan regulators, based on their homology to
Saccharomyces cerevisiae
, including
SMI1
and protein kinase C (PKC) pathway components. We identified a role for the
SMI1
in biofilm matrix glucan production and development of the associated drug resistance phenotype. This pathway appears to act through transcription factor Rlmp and glucan synthase Fks1p. The phenotypes of these mutant biofilms mimicked those of the
smi1
Δ/
smi1
Δ biofilm, and overexpression of
FKS1
in the
smi1
Δ/
smi1
Δ mutant restored the biofilm resistant phenotype. However, control of this pathway is distinct from that of the upstream PKC pathway because the
pkc1
Δ/
pkc1
Δ,
bck1
Δ/
bck1
Δ,
mkk2
Δ/
mkk2
Δ, and
mkc1
Δ/
mkc1
Δ biofilms retained the resistant phenotype of the parent strain. In addition, resistance to cell-perturbing agents and gene expression data do not support a significant role for the cell wall integrity pathway during the biofilm formation. Here we show that Smi1p functions in conjunction with Rlm1p and Fks1p to produce drug-sequestering biofilm β-glucan. Our work provides new insight into how the
C. albicans
biofilm matrix production and drug resistance pathways intersect with the planktonic cell wall integrity pathway. This novel connection helps explain how pathogens in a multicellular biofilm community are protected from anti-infective therapy.
Uracil-DNA Glycosylase of Thermoplasma acidophilumDirects Long-Patch Base Excision Repair, Which Is Promoted by Deoxynucleoside Triphosphates and ATP/ADP, into Short-Patch Repair
Authors: Moen Marivi N. , Knævelsrud Ingeborg , Haugland Gyri T. , Grøsvik Kristin , Birkeland Nils-Kåre , Klungland Arne , Bjelland Svein 
Published: June 2011

ABSTRACT

Hydrolytic deamination of cytosine to uracil in DNA is increased in organisms adapted to high temperatures. Hitherto, the uracil base excision repair (BER) pathway has only been described in two archaeons, the crenarchaeon
Pyrobaculum aerophilum
and the euryarchaeon
Archaeoglobus fulgidus
, which are hyperthermophiles and use single-nucleotide replacement. In the former the apurinic/apyrimidinic (AP) site intermediate is removed by the sequential action of a 5′-acting AP endonuclease and a 5′-deoxyribose phosphate lyase, whereas in the latter the AP site is primarily removed by a 3′-acting AP lyase, followed by a 3′-phosphodiesterase. We describe here uracil BER by a cell extract of the thermoacidophilic euryarchaeon
Thermoplasma acidophilum
, which prefers a similar short-patch repair mode as
A. fulgidus
. Importantly,
T. acidophilum
cell extract also efficiently executes ATP/ADP-stimulated long-patch BER in the presence of deoxynucleoside triphosphates, with a repair track of ∼15 nucleotides. Supplementation of recombinant uracil-DNA glycosylase (rTaUDG; ORF Ta0477) increased the formation of short-patch at the expense of long-patch repair intermediates, and additional supplementation of recombinant DNA ligase (rTalig; Ta1148) greatly enhanced repair product formation. TaUDG seems to recruit AP-incising and -excising functions to prepare for rapid single-nucleotide insertion and ligation, thus excluding slower and energy-costly long-patch BER.
Different Conformations of the Kinase-On and Kinase-Off Signaling States in the Aer HAMP Domain
Authors: Watts Kylie J. , Johnson Mark S. , Taylor Barry L. 
Published: June 2011

ABSTRACTHAMP domains are sensory transduction modules that connect input and output domains in diverse signaling proteins from archaea, bacteria, and lower eukaryotes. Here, we employedin vivodisulfide cross-linking to explore the structure of the HAMP domain in theEscherichia coliaerotaxis receptor Aer. Using an Aer HAMP model based on the structure ofArchaeoglobus fulgidusAf1503-HAMP, the closest residue pairs at the interface of the HAMP AS-1 and AS-2′ helices were determined and then replaced with cysteines and cross-linkedin vivo. Except for a unique discontinuity in AS-2, the data suggest that the Aer HAMP domain forms a parallel four-helix bundle that is similar to the structure of Af1503. The HAMP discontinuity was associated with a segment of AS-2 that was recently shown to interact with the Aer-PAS sensing domain. The four-helix HAMP bundle and its discontinuity were maintained in both the kinase-on and kinase-off states of Aer, although differences in the rates of disulfide formation also indicated the existence of different HAMP conformations in the kinase-on and kinase-off states. In particular, the kinase-on state was accompanied by significantly increased disulfide formation rates at the distal end of the HAMP four-helix bundle. This indicates that HAMP signaling may be associated with a tilting of the AS-1 and AS-2′ helices, which may be the signal that is transmitted to the kinase control region of Aer.
Taking the Escherichia coli TonB Transmembrane Domain “Offline”? Nonprotonatable Asn Substitutes Fully for TonB His20
Authors: Swayne Cheryl , Postle Kathleen 
Published: June 2011

ABSTRACT
The TonB system of Gram-negative bacteria uses the proton motive force (PMF) of the cytoplasmic membrane to energize active transport of nutrients across the outer membrane. The single transmembrane domain (TMD) anchor of TonB, the energy transducer, is essential. Within that TMD, His20 is the only TMD residue that is unable to withstand alanine replacement without a loss of activity. H20 is required for a PMF-dependent conformational change, suggesting that the importance of H20 lies in its ability to be reversibly protonated and deprotonated. Here all possible residues were substituted at position 20 (H20X substitutions). The His residue was also relocated throughout the TonB TMD. Surprisingly, Asn, a structurally similar but nonprotonatable residue, supported full activity at position 20; H20S was very weakly active. All the remaining substitutions, including H20K, H20R, H20E, and H20D, the obvious candidates to mimic a protonated state or support proton translocation, were inactive. A second-site suppressor, ExbB(A39E), indiscriminately reactivated the majority of H20 substitutions and relocations, including H20V, which cannot be made protonatable. These results suggested that the TonB TMD was not on a proton conductance pathway and thus only indirectly responds to PMF, probably via ExbD.
Cryptococcus neoformans Requires a Functional Glycolytic Pathway for Disease but Not Persistence in the Host
Authors: Price Michael S. , Betancourt-Quiroz Marisol , Price Jennifer L. , Toffaletti Dena L. , Vora Haily , Hu Guanggan , Kronstad James W. , Perfect John R. 
Published: June 2011

ABSTRACTCryptococcus neoformansis an important fungal pathogen of immunocompromised individuals, with a close relative,Cryptococcus gattii, emerging as a serious threat for the immunocompetent. During initial infection,C. neoformanscolonizes the airspaces of the lungs, resulting in pneumonia, and subsequently migrates to the central nervous system (CNS). We sought to understand fungal carbon utilization during colonization of these fundamentally different niches within the host, in particular the roles of gluconeogenesis and glycolysis. We created mutants at key points in the gluconeogenesis/glycolysis metabolic pathways that are restricted for growth on lactate and glucose, respectively. A phosphoenolpyruvate carboxykinase mutant (thepck1∆mutant), blocked for entry of 2- and 3-carbon substrates into gluconeogenesis and attenuated for virulence in a murine inhalation model, showed wild-type (WT) persistence in a rabbit cerebrospinal fluid (CSF) model of cryptococcosis. Conversely, both the pyruvate kinase (pyk1∆) and the hexose kinase I and II (hxk1∆/hxk2∆) mutants, which show impaired glucose utilization, exhibited severely attenuated virulence in the murine inhalation model of cryptococcosis and decreased persistence in the CNS in both the rabbit CSF and the murine inhalation models while displaying adequate persistence in the lungs of mice. These data suggest that glucose utilization is critical for virulence ofC. neoformansand persistence of the yeast in the CNS.IMPORTANCECryptococcus neoformansis an emerging fungal pathogen of humans and is responsible for approximately 625,000 deaths annually among those suffering from HIV infection/AIDS. The ability of this fungus to persist in the host, coupled with its propensity to colonize the CNS, makes the understanding of nutrient acquisition in the host a primary concern. In this study, we report a requirement of glucose utilization for virulence ofC. neoformansthat is separate from its role in ATP production in the pathogen. Furthermore, we show that inhibition of glycolysis is a viable antifungal drug target, and impaired ATP production via thePYK1deletion may serve as a model for dormant/chronic fungal infection in the host. Taken together, these results demonstrate the critical importance of understanding basic metabolic processes of the fungus in the context of host-pathogen interactions.
Fertility and whelping complications in bitches following correction of vaginal abnormalities
Authors: Moxon R. , England G. C. W. 
Published: June 2011

The fertility and whelping complications of normal bitches and of bitches that had had surgery to correct a vaginal abnormality of varying severities were compared retrospectively. Reproductive performance and whelping statistics were compared between 37 bitches that had been diagnosed with a vaginal abnormality and 37 age‐ and breed‐matched bitches with no history of vaginal abnormalities. There were no significant differences in reproductive performance between the affected and control bitches. When analysed by the severity of the abnormality, pregnancy rates were significantly lower for the group of bitches with the most severe abnormalities compared with the group of bitches that had mild vaginal abnormalities. Furthermore, the bitches that had severe abnormalities were significantly more likely to require a caesarean section than those with mild abnormalities.