R1 Site Research Articles

Identification of the pest outbreak in the coastal mangrove ecosystem of Mahakam Delta, East Kalimantan, Indonesia

Abstract. Harmonis, Haqiqi MT, Fahroni MFA, Jefry, Gunawan S, Sekedang MA, Rahmat D, Azhar NF, Putra MOPS, Kusuma FD, Hapsari MT, Muhammad FA, Diana R, Sudarmadji T, Amirta R, Ariyanto, Saud OR, Sofyan FPM, Fajriansyah, Asngari AMS, Bulo YS, Salman I, Rizaldi R, Lubis KM. 2024. Identification of the pest outbreak in the coastal mangrove ecosystem of Mahakam Delta, East Kalimantan, Indonesia. Biodiversitas 25: 829-835. Mangrove ecosystems are considered the most essential areas in the wetland since they sequester carbon more efficiently than terrestrial ecosystems. Thus, they have received significant attention as a nature-based solution to achieve the Naturally Determined Contributions in the commitment to global climate change mitigation. Currently, the degradation of mangroves has been linked to serious threats, including pest outbreaks. Our primary objective was to assess the pest outbreaks that occurred in the coastal mangroves of the Mahakam Delta, Indonesia. This study was conducted in two areas in Tanjung (R1 and R2) and one area in Pulau (R3). A total of 19 observation plots with a size of 10 × 10 m2 were made. The water quality was further measured to identify the natural conditions affecting the outbreaks. In the present study, it was found that significant disturbance of the mangrove plants occurred due to invasions by Amphibalanus amphitrite Darwin, 1854 and Sphaeroma terebrans Spence Bate, 1866. The dangerous attack from S. terebrans has only been found at the R1 site, where we found environmental conditions such as high dissolved oxygen (DO), high total dissolved solids (TDS), and high salinity. In this area, it could affect the death of adult Avicennia alba Blume and Sonneratia alba Sm. The results obtained from this study are expected to provide preliminary data to design the best management practices in order to enhance the effectiveness of the mangrove rehabilitation strategy in the Mahakam Delta.

Design of MMP-1 inhibitors via SAR transfer and experimental validation

New matrix metalloproteinase 1 (MMP-1) inhibitors were predicted using the structure–activity relationship (SAR) transfer method based on a series of analogues of kinesin-like protein 11 (KIF11) inhibitors. Compounds 5–7 predicted to be highly potent against MMP-1 were synthesized and tested for MMP-1 inhibitory activity. Among these, compound 6 having a Cl substituent at the R1 site was found to possess ca. 3.5 times higher inhibitory activity against MMP-1 than the previously reported compound 4. The observed potency was consistent with the presence of an SAR transfer event between analogous MMP-1 and KIF11 inhibitors. Pharmacophore fitting revealed that the higher inhibitory activity of compound 6 compared to compound 4 against MMP-1 might be due to a halogen bond interaction between the Cl substituent of compound 6 and residue ARG214 of MMP-1.

Exploring facile synthesis and cholinesterase inhibiting potential of heteroaryl substituted imidazole derivatives for the treatment of Alzheimer’s disease

Alzheimer’s disease (AD) is a neurodegenerative disorder and cholinesterase (ChE) enzymes are considered as crucial targets for the treatment of AD. Herein, a series of heteroaryl substituted imidazole derivatives (5a-5x) was prepared using amino acid catalyzed, one-pot facile synthetic approach. In this context, the catalytic potentials of different amino acids were investigated and 15 mol% of glutamic acid was identified as the most suitable catalyst to obtain the target products in good yields up to 90 %. These structurally exciting heterocyclic hybrids were screened against acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) enzymes. This series displayed moderate to excellent inhibitory potential against AChE with IC50 values > 25 µM and the most active compound was 3-(4-(1-(3,5-dimethylphenyl)-4,5-diphenyl-1H-imidazol-2-yl)-1-phenyl-1H-pyrazol-3-yl)–2H-chromen-2-one (5x) with IC50 value of 25.83 ± 0.25 µM.This inhibitory potential was attributed to hydrophobicity as the major contributory factor. The most potent compound against BChE was 1,3-diphenyl-4-(1,4,5-triphenyl-1H-imidazol-2-yl)-1H-pyrazole (5a) with IC50 value of 0.35 ± 0.02 µM followed by other potent compounds 5p, 5 m, 5x, 5b, 5c, 5e and 5f with IC50 values < 10 µM. SAR studies further revealed that coumarinyl moiety at R1 position in the imidazolylpyrazole skeleton significantly improved the overall cholinesterase inhibitory potential. However, a simple phenyl ring attached at this R1 site was highly effective and selective for BChE inhibition (5a) over AChE. Docking data also demonstrated the interaction of 5x and AChE with a docking score of 7564 and atomic contact energy (ACE) value of –291.90 kcal/mol whereas docking score for 5a against BChE was 7096 with ACE value of –332.95 kcal/mol. The results altogether suggest further investigations of the heteroaryl substituted imidazole core skeleton in search of potential leads towards designing of new anti-cholinesterase drugs for the treatment of AD.

Impact of Total Mesopancreas Excision on the Superior Mesenteric Artery Margin Status

Introduction: Pancreatic ductal head adenocarcinoma (PDHAC) is a lethal disease with poor prognosis and surgical resection with complete microscopic resection (R0) in association with multimodal treatment currently represents the only curative strategy. The dissected margins around the superior mesenteric artery (SMA) are reported to be the most favorable R1 site for PDHAC. Therefore, modifications have been made to the classic surgical technique (Whipple) to improve the rate of R1 resections, such as the total mesopancreas excision (TMpE). The purpose of this study was to evaluate the impact of TMpE on the SMA margin status. Methods: This study included 93 patients with PDHAC who were treated in the Hepatobiliary Surgery Department of Miguel Servet University Hospital in Saragossa, Spain, during a 7-years period (2010-2017). They were divided into two groups. Group A included patients who underwent pancreaticoduodenectomy (PD) with TMpE and group B included standar PD (S-PD). The collected data were prospectively collected and statistically analyzed by SPSS 19.0 statistical software package. Results: The R0 resection rate was 52.1% (25/48) in Group A and 31.1% (14/45) in Group B. There was significant difference in the R0 resection rate between the two groups (p=0.027). The R1 SMA resection margin rate was 18. Conclusions: TMpE improves the oncological results of PD for pancreatic head adenocarcinoma as it halves the rate of R1 resections at the SMA resection margin.

Improvement of the corrosion resistance of mild steel in sulfuric acid by new organic-inorganic hybrids of Benzimidazole-Pyrophosphate: Facile synthesis, characterization, experimental and theoretical calculations (DFT and MC)

In this work, a new generation of corrosion inhibitors composed of xMCl2-yNa4P2O7 (MCl2 = 2,2’-dibenzimidazolyl butane dichlorhydrates) hybrids materials have been synthesized successfully with five molar ratios (R1, R2, R3, R4, and R5) by soft chemistry route and characterized. The synthesis was performed in aqueous solutions by the ionic exchange between the pyrophosphate anions and the 2,2′-dibenzimidazolyl butane dichlorhydrates cations. The structure and morphology of the synthesized hybrids are studied by infrared spectroscopy (FT-IR), UV–Visible analysis (UV-vis), X-ray diffraction (XRD), and scanning electron microscopy (SEM). The infrared results show the formation of a new band N-O-P confirming the hybrid structure. The crystalline structure was improved after adding pyrophosphate, confirming the phosphate nucleation and a better settlement of the crystals. These crystals were clearly shown in the SEM images. The corrosion inhibition performance of the prepared compounds were studied on mild steel in 0.5 M sulfuric acid by electrochemical impedance spectroscopy (EIS) and polarization studies. The inhibition efficiency increased with increasing inhibitor concentration, while the corrosion current density decreased. Indeed, the best inhibitor of these hybrids is R1 with an inhibition power of 97.1 % at 300 ppm. The effect of temperature on inhibitory efficiency in a range of 298 to 328K is discussed. The SEM images are also confirmed that the R1 retards the corrosion on the mild steel surface. The EDX analysis presented that this surface is mainly composed of N and P elements. The theoretical calculation results show that the benzimidazole cycle and the heteroatoms of N, O and P are the active sites of inhibitor R1.

Use of Ethylenediurea (EDU) in identifying indicator cultivars of Indian clover against ambient ozone

Three clover (Trifolium alexandrium L.) cultivars (Bundel, Wardan and JHB-146) were assessed for their responses to ambient ozone (O3) with respect to growth, physiological and biochemical parameters at two rural sites (R1 and R2) using ethylenediurea (EDU). EDU solution (300ppm) was applied as soil drench, 10 days after germination (DAG) at an interval of 10 days up to 80 DAG. The average O3 concentrations were 52.76 and 60.86 ppb at R1 and R2 sites, respectively during the experimental period. Ambient O3 induced visible symptoms in all the cultivars at both the sites, with more at R2 site having high ambient O3 levels. Visible injury was observed first in non-EDU treated plants of Wardan at R2 site. Wardan also showed maximum reduction in leaf injury under EDU treatment at both the sites with more at R2. Under EDU treatment, better adaptation to ambient O3 at initial age of observation and higher acquisition of resources at later ages of observation at both the sites led to better physiological and biochemical adaptations in Wardan. Bundel retained more biomass in shoot as is reflected with higher shoot/root ratio and thus focused more on repair and defense. Shoot/root ratio of JHB-146 did not respond to EDU treatment and thus showed insignificant variations except at initial age of observation at R1 site. This study clearly suggests that Wardan and Bundel are sensitive to ambient O3 and can be used as bioindicator species in areas having higher O3 levels using EDU as a research tool.

Novel DNA packaging recognition in the unusual bacteriophage N15

Phage lambda׳s cosB packaging recognition site is tripartite, consisting of 3 TerS binding sites, called R sequences. TerS binding to the critical R3 site positions the TerL endonuclease for nicking cosN to generate cohesive ends. The N15 cos (cosN15) is closely related to cosλ, but whereas the cosBN15 subsite has R3, it lacks the R2 and R1 sites and the IHF binding site of cosBλ. A bioinformatic study of N15-like phages indicates that cosBN15 also has an accessory, remote rR2 site, which is proposed to increase packaging efficiency, like R2 and R1 of lambda. N15 plus five prophages all have the rR2 sequence, which is located in the TerS-encoding 1 gene, approximately 200bp distal to R3.An additional set of four highly related prophages, exemplified by Monarch, has R3 sequence, but also has R2 and R1 sequences characteristic of cosB–λ. The DNA binding domain of TerS-N15 is a dimer.

2D, 3D-QSAR, and pharmacophore studies on thiazolidine-4-carboxylic acid derivatives as neuraminidase inhibitors in H3N2 influenza virus

Thiazolidine-4-carboxylic acid derivative compounds with their inhibitory activity against influenza A neuraminidase (NA) were used as a data set for developing the quantitative structure–activity relationship (QSAR) model. The 2D-QSAR model was developed using multiple linear regression analysis with r 2 and r 2 (CV) value of 0.98 and 0.70, respectively. The generated QSAR model has shown that the electrostatic and steric properties have the predominant influence on biological activity. 3D-QSAR was modeled with r 2 value of 0.98 and RMSD of 0.12. The pharmacophore alignments were generated and suggested that the hydrophobic, hydrogen bond donor, and hydrogen bond acceptor features on R1 and R2 site substitutions of the core of thiazolidine are important properties to enhance the activities of molecule against influenza A NA.

High-Resolution Structure of a Protein Spin-Label in a Solvent-Exposed β-Sheet and Comparison with DEER Spectroscopy

X-ray crystallography has been a useful tool in the development of site-directed spin labeling by resolving rotamers of the nitroxide spin-label side chain in a variety of α-helical environments. In this work, the crystal structure of a doubly spin-labeled N8C/K28C mutant of the B1 immunoglobulin-binding domain of protein G (GB1) was solved. The double mutant formed a domain-swapped dimer under crystallization conditions. Two rotameric states of the spin-label were resolved at the solvent-exposed α-helical site, at residue 28; these are in good agreement with rotamers previously reported for helical structures. The second site, at residue 8 on an interior β-strand, shows the presence of three distinct solvent-exposed side-chain rotamers. One of these rotamers is rarely observed within crystal structures of R1 sites and suggests that the H(α) and S(δ) hydrogen bond that is common to α-helical sites is absent at this interior β-strand residue. Variable temperature continuous wave (CW) experiments of the β-strand site showed two distinct components that were correlated to the rotameric states observed in crystallography. Interestingly, the CW data at room temperature could be fit without the use of an order parameter, which is consistent with the lack of the H(α) and S(δ) interaction. Additionally, double electron electron resonance (DEER) spectroscopy was performed on the GB1 double mutant in its monomeric form and yielded a most probable interspin distance of 25 ± 1 Å. In order to evaluate the accuracy of the measured DEER distance, the rotamers observed in the crystal structure of the domain-swapped GB1 dimer were modeled into a high-resolution structure of the wild type monomeric GB1. The distances generated in the resulting GB1 structural models match the most probable DEER distance within ~2 Å. The results are interesting as they indicate by direct experimental measurement that the rotameric states of R1 found in this crystal provide a very close match to the most probable distance measured by DEER.

Theoretical studies on the interaction of biphenyl inhibitors with Mycobacterium tuberculosis protein tyrosine phosphatase MptpB

MptpB is an essential secreted virulence factor for M. tuberculosis. Inhibition of MptpB impairs mycobacterial survival in host macrophages and thus helps reduce tuberculosis infections. However, the binding mode of the biphenyl inhibitors, which are known as some of the most potent MptpB inhibitors, remains unclear. In this study, to understand the interactions between biphenyl inhibitors and MptpB, docking and molecular dynamics simulations were carried out using AutoDock and GROMACS softwares. Calculation results show that all the biphenyl inhibitors can be docked to the binding site of MptpB, with the acid warheads forming a hydrogen bond network at the active site. But the binding modes of other terminals of these inhibitors are different. The cyclohexyl and trifluoromethyl substituents at R1 and R2 sites are necessary for the inhibitors to adopt their double-site binding mechanism. The estimated binding affinities are basically consistent with the experimental results. MD simulations show that these binding complexes display different stability.

On the Outstanding Antioxidant Capacity of Edaravone Derivatives through Single Electron Transfer Reactions

The single electron transfer (SET) reactions from the neutral and anionic forms of 27 edaravone derivatives to 11 free radicals have been studied using density functional theory and the Marcus theory. All of the studied compounds were found to be able to efficiently scavenge at least some of the studied radicals. More than half of them were found to be excellent free radical scavengers, via SET, under physiological conditions. Their SET reactions with all the studied radicals were found to have rate constants ranging from 10(6) to 10(9) M(-1) s(-1) (diffusion limited). Therefore, they are predicted to be versatile scavengers, able to deactivate free radicals of different nature. Functionalizing the R1 and R3 sites of the pyrazol-5-one ring with the NO group is not recommended for edaravone derivatives designed as free radical scavengers through the SET mechanism. In general, this family of compounds was found to be exceptionally good for scavenging free radicals by transferring one electron. Moreover they are predicted to be outstanding scavengers, even if they would only react by SET. In addition, the acid-base equilibrium was found to play an important role in their activity.

R2 and R2/R1 hybrid non-autonomous retrotransposons derived by internal deletions of full-length elements

BackgroundR2 is a non-long terminal repeat (non-LTR) retrotransposable element that inserts site specifically into the 28S genes of the ribosomal (r)RNA gene loci. Encoded at the 5' end is a ribozyme that generates the precise 5' end by self-cleavage of a 28S gene cotranscript. Sequences at the 3' end are necessary for the R2 protein to bind RNA and initiate the target primed reverse transcription (TPRT) reaction. These minimal RNA requirements suggested that if recombination/DNA repair conjoined the 5' and 3' ends of R2, the result would be a non-autonomous element that could survive as long as autonomous R2 elements supplied the TPRT activity.ResultsA PCR-based survey of 39 Drosophila species aided by genomic sequences from 12 of these species revealed two types of non-autonomous elements. We call these elements SIDEs (for ‘Short Internally Deleted Elements’). The first consisted of a 5' ribozyme and a 3' end of an R2 element as predicted. Variation at the 5' junctions of the R2 SIDE copies was typical for R2 insertions suggesting their propagation by TPRT. The second class of SIDE contained sequences from R1 elements, another non-LTR retrotransposon that inserts into rRNA gene loci. These insertions had an R2 ribozyme immediately upstream of R1 3' end sequences. These hybrid SIDEs were inserted at the R1 site with 14 bp target site duplications typical of R1 insertions suggesting they used the R1 machinery for retrotransposition. Finally, the survey revealed examples of U12 small nuclear (sn)RNA and tRNA sequences at the 5' end of R2 elements suggesting the R2 reverse transcriptase can template jump from the R2 transcript to a second RNA during TPRT.ConclusionsThe R2 SIDE and R2/R1 hybrid SIDEs are rare examples of non-autonomous retrotransposons in the Drosophila genome. Associated non-autonomous elements and in vivo template jumps are two additional characteristics R2 shares with other non-LTR retrotransposons such as mammalian L1s. Analysis of the hybrid SIDEs provides supporting evidence that R1 elements, like R2 elements, recognize their 3' untranslated region (UTR) sequences and, thus, belong to the stringent class of non-LTR elements.

COMPARATIVE MOLECULAR FIELD ANALYSIS OF ANTI-TUBULIN AGENTS WITH INDOLE RING BINDING AT THE COLCHICINE BINDING SITE

A 3D-QSAR study using comparative molecular field analysis (CoMFA) was carried out on anti-tubulin agents with indole as a nucleus core. The structures of the compounds were obtained using docking calculations, and were then subjected to alignment procedures. CoMFA calculations for the 42 ligands that were examined as the training set gave a q2 value of 0.623 in correlation with experimental IC50 values for the inhibition of MKN-45 gastric cancer cells. Calculation for the test set of 17 ligands resulted in an r2 value of 0.714. The calculated results suggest that the R3 functional group site (see structure in Fig. 1) favored bulky groups while R1, R2, and R4 sites favored the opposite. At the R5 and R6 sites, parts of the region favored bulky groups while other parts favored the opposite. As for the electrostatic aspect, the R3 site was found to favor groups with a negative partial charge. At the R2 site, part of the region favored the group with a negative partial charge while other regions favored groups with a positive partial charge. The R4 and R5 sites favored groups with negative and positive partial charges, respectively, with a less favorable magnitude when compared with the R2 and R3 sites. The R1 and R6 sites did not exhibit significant electrostatic favor. Correlation of the results with IC50 values of ligands were analyzed and discussed.

DiaA Dynamics Are Coupled with Changes in Initial Origin Complexes Leading to Helicase Loading

Chromosomal replication initiation requires the regulated formation of dynamic higher order complexes. Escherichia coli ATP-DnaA forms a specific multimer on oriC, resulting in DNA unwinding and DnaB helicase loading. DiaA, a DnaA-binding protein, directly stimulates the formation of ATP-DnaA multimers on oriC and ensures timely replication initiation. In this study, DnaA Phe-46 was identified as the crucial DiaA-binding site required for DiaA-stimulated ATP-DnaA assembly on oriC. Moreover, we show that DiaA stimulation requires only a subgroup of DnaA molecules binding to oriC, that DnaA Phe-46 is also important in the loading of DnaB helicase onto the oriC-DnaA complexes, and that this process also requires only a subgroup of DnaA molecules. Despite the use of only a DnaA subgroup, DiaA inhibited DnaB loading on oriC-DnaA complexes, suggesting that DiaA and DnaB bind to a common DnaA subgroup. A cellular factor can relieve the DiaA inhibition, allowing DnaB loading. Consistently, DnaA F46A caused retarded initiations in vivo in a DiaA-independent manner. It is therefore likely that DiaA dynamics are crucial in the regulated sequential progress of DnaA assembly and DnaB loading. We accordingly propose a model for dynamic structural changes of initial oriC complexes loading DiaA or DnaB helicase.

Molecular Mechanisms of Thioredoxin and Glutaredoxin as Hydrogen Donors for Mammalian S Phase Ribonucleotide Reductase

Ribonucleotide reductase (RNR) catalyzes the rate-limiting step in deoxyribonucleotide synthesis essential for DNA replication and repair. RNR in S phase mammalian cells comprises a weak cytosolic complex of the catalytic R1 protein containing redox active cysteine residues and the R2 protein harboring the tyrosine free radical. Each enzyme turnover generates a disulfide in the active site of R1, which is reduced by C-terminally located shuttle dithiols leaving a disulfide to be reduced. Electrons for reduction come ultimately from NADPH via thioredoxin reductase and thioredoxin (Trx) or glutathione reductase, glutathione, and glutaredoxin (Grx), but the mechanism has not been clarified for mammalian RNR. Using recombinant mouse RNR, we found that Trx1 and Grx1 had similar catalytic efficiency (k(cat)/K(m)). With 4 mm GSH, Grx1 showed a higher affinity (apparent K(m) value, 0.18 microm) compared with Trx1 which displayed a higher apparent k(cat), suggesting its major role in S phase DNA replication. Surprisingly, Grx activity was strongly dependent on GSH concentrations (apparent K(m) value, 3 mm) and a Grx2 C40S mutant was active despite only one cysteine residue in the active site. This demonstrates a GSH-mixed disulfide mechanism for glutaredoxin catalysis in contrast to the dithiol mechanism for thioredoxin. This may be an advantage with the low levels of RNR for DNA repair or in tumor cells with high RNR and no or low Trx expression. Our results demonstrate mechanistic differences between the mammalian and canonical Escherichia coli RNR enzymes, which may offer an explanation for the nonconserved shuttle dithiol sequences in the C terminus of the R1.

Fluctuation-Induced Excess Conductivity in R1−x Ca x : 123 Superconductors

Fluctuation induced conductivity of Ca substitution at R sites of R1−xCax: 123 superconductors with various x and R is investigated. This work is done by using the reported data of Sedky et al. (Phys. Rev. B 58(18):12495, 1998). The logarithmic plots of Δσ and reduced temperature € reveal three different exponents corresponding to two different crossover temperatures. The first exponent at ln € (−1≥ln €≥−2) and its values are close to 1, for which order parameter dimensionalities (OPD) are two dimensional (2D). The second exponent at ln € (−2≥ln €≥−3.5) and its values are close to 2, for which OPD are neither two dimensional (2D) nor three dimensional (3D). The third exponent at ln € (−3.5≥ln €≥−8) and its values are close to 0.5, for which OPD are three dimensional (3D). The different values of the interlayer coupling are also calculated in the normal and mean field regions, respectively. Our results are discussed in terms of oxygen disorder and system anisotropy produced by Ca substitution in R1−xCax: 123 systems.

Length polymorphism of integrated copies of R1 and R2 retrotransposons in the German cockroach (Blattella germanica) as a potential marker for population and phylogenetic studies

Using polymerase chain reaction technique with primers flanking target sites of retrotransposons R1 and R2, integrated copies of these transposable elements were amplified in various cockroach species (Blattodea). It was shown that each species has a unique pattern of "5'-undertranscripts" with the definite set of amplified fragments of different lengths. Intraspecies polymorphism was revealed in analysis of German cockroach specimens obtained upon individual mating. This is the first report providing results of identifying, cloning, and sequencing extended fragments (5'-truncated copies) of Blatella germanica R1 and R2 retrotransposons. It may be assumed that patterns of 5'-truncated copies of R1 and R2 elements can be used as markers in population and phylogenetic studies. Moreover, cloned and sequenced fragments will be employed in our further studies for screening of the German cockroach genomic library in order to detect full-length copies in this class transposable elements.

Longitudinal study of vaginal flora: Increasing periodontal disease (PD) burden is associated with increased risk for bacterial vaginosis (BV)

(PD) BURDEN IS ASSOCIATED WITH INCREASED RISK FOR BACTERIAL VAGINOSIS (BV) WILLIAM ANDREWS, MARJORIE JEFFCOAT, JANE SCHWEBKE, MARK KLEBANOFF, JUN ZHANG, SUZANNE CLIVER, University of Alabama at Birmingham, Obstetrics/Gynecology, Birmingham, Alabama, University of Pennsylvania, Dentistry, Philadelphia, Pennsylvania, University of Alabama at Birmingham, Medicine, Birmingham, Alabama, National Institutes of Health (NIH), Epidemiology, Statistics and Prevention Research, Bethesda, Maryland, National Institutes of Health (NIH), Epidemiology Branch, Bethesda, Maryland OBJECTIVE: To characterize the association between PD burden and risk of BV. STUDY DESIGN: The Longitudinal Study of Vaginal Flora included nonpregnant women who underwent extensive evaluation of the vaginal flora every three months for one year. In this secondary analysis, BV was defined using both Nugent’s and Amsel’s criteria. A dental examination was performed at the first study visit. PD at any of 168 dental sites (6/tooth) was defined as clinical attachment loss (CAL) of R4 mm. RESULTS: Dental exams were performed on 3540 (98%) of 3620 study subjects. At the first visit, 41% (n=1438) had Amsel-BV and 40% (n=1438) had Nugent-BV. 25% had PD at R1 site and 5% at O25 sites. Compared to BV-negative women, the number of dental sites was significantly higher in women with Nugent-BV (Wilcoxon p=.002) and Amsel-BV (Wilcoxon p=.008). The number of sites with PD were categorized as 0 (n=2309), 1-2 (n=319), 3-25 (n=726), 26-75 (n=148), and R76 (n=38). As the number of sites with PD (R4 mm CAL) increased, so did the risk of both Nugent-BV (Mantel-Haenszel [M-H] p=.0005) and Amsel-BV (M-H p=.0009). Increasing numbers of PD sites were significantly associated with higher Mobiluncus (M-H p!.0001) and Gardnerella/Bacteroides (M-H p=.019), but not Lactobacillus Nugent scores (M-H p=.140). Increasing numbers of PD sites were significantly associated with amine odor (M-H p!.0001), homogeneous discharge (M-H p=.016), clue cells (M-H p=.019), vaginal pHO4.5 (M-H p=.0003) and T. vaginalis (M-H p=.0002). After adjusting for confounders associated with PD, high PD burden was associated with increased risk of Nugent-BV (26-75 sites: OR=1.4, 95%CI=1.0-2.0 and R76 sites: OR=2.0, 95%CI=1.04-4.0) and Amsel-BV (26-75 sites: OR=1.1, 95%CI=0.8-1.6 and R76 sites: OR=2.5, 95%CI=1.2-4.9). CONCLUSION: Increasing burden of periodontal disease is associated with a statistically significant increased risk of bacterial vaginosis.

SELECTIVE ACTION OF FLUOROQUINOLONES AGAINST INTRACELLULAR AMASTIGOTES OF LEISHMANIA (VIANNIA) PANAMENSIS IN VITRO

We have demonstrated that fluoroquinolones, a class of antibacterial agents that act through inhibition of type II DNA topoisomerases, exert selective action against intracellular amastigotes of Leishmania (Viannia) panamensis at concentrations that are achievable in vivo. Drug cytotoxicity assays employing the luciferase reporter gene revealed that intracellular amastigotes were 6.6- to 25.9-fold more sensitive than human macrophages (P < 0.05) to second-generation fluoroquinolones in vitro. The most selective agents (enoxacin and ciprofloxacin) exhibited 2 orders of magnitude greater potency against parasites (50% effective dose [ED50] = 54.9-83.4 microM) than host cells (ED50 = 1,425-1,740 microM). Linear regression analysis of ED50 data confirmed a complete lack of correlation (r = 0.001) between the relative drug sensitivities of parasites and host cells. A potential relationship between the structures of fluoroquinolones and their relative leishmanicidal activities was observed. The key substituents of the basic pyridone beta-carboxylic acid nucleus accounting for enhanced antiparasite potency and selectivity appear to be a nitrogen at position 8 of the bicyclic nucleus (enoxacin), a cyclopropyl substituent at the R1 site (ciprofloxacin), and linkage of the R1 and X8 groups by a CH3CHO bridge to form a tricyclic compound (ofloxacin). These findings support the potential of fluoroquinolones and derivatives as novel antileishmanials and encourage their clinical evaluation.

Cooperative Interactions between RUNX2 and Homeodomain Protein-binding Sites Are Critical for the Osteoblast-specific Expression of the Bone Sialoprotein Gene

The bone sialoprotein (Bsp) gene provides an excellent model for studying mechanisms controlling osteoblast-specific gene expression. Although the RUNX2 transcription factor directly regulates many osteoblast-related genes, its function in Bsp expression remains uncertain. By using chromatin immunoprecipitation (ChIP) analysis in MC3T3-E1 (clone MC-4) preosteoblast cells, RUNX2 was shown to bind a chromatin fragment containing the proximal Bsp promoter. Two putative RUNX2-binding sites (R1 and R2) were identified within this region of the mouse, rat, and human genes and were shown to bind RUNX2 in vitro and in vivo (by ChIP assay). Site-specific mutagenesis established that both sites act as osteoblast-specific transcriptional enhancers and together account for nearly two-thirds of the total promoter activity. In addition, functional cooperativity was observed between the R2 site and an adjacent homeodomain protein-binding site previously characterized by this laboratory (the C site). All three sites (R1, R2, and C) are necessary for maximal promoter activity in osteoblasts. DLX5 in MC-4 cell nuclear extracts binds to the C site in vitro. Furthermore, ChIP assays revealed that DLX5 is selectively associated with chromatin in the vicinity of the C site only when Bsp is transcriptionally active. Finally, co-immunoprecipitation assays detected a physical complex containing DLX5 and RUNX2. Taken together, our data show that RUNX2 is a direct regulator of Bsp in osteoblasts and that it functions in cooperation with DLX5 or a related factor to activate osteoblast-specific gene expression.