Protein C and/or S deficiency presenting as peripheral arterial insufficiency

Although protein C and/or S deficiency has frequently been associated with venous thromboembolic events, instances of arterial thromboses have been reported. However, the exact incidence of protein C and/or S deficiency in patients with peripheral arterial insufficiency has not been established. Furthermore, given the lack of adequate studies to define the natural history and angiographic findings of these patients, the treatment has not been well delineated. Therefore, we conducted a prospective study to investigate the prevalence, characteristic angiographic findings and optimal treatments in patients with peripheral arterial insufficiency associated with protein C and/or S deficiency. Between September 2000 and August 2004, 133 patients who presented with peripheral arterial insufficiency underwent hypercoagulability tests before the initiation of any treatments. Of these, 11 patients (8.3%) with protein C and/or S deficiency were included in this study. There were nine males and two females. The ages ranged from 38 years to 72 years (mean 57 years). All patients showed characteristic angiographic findings: long segment thrombotic occlusion of a main peripheral artery without evidence of atherosclerosis or with mild atherosclerotic changes in the aorta and other major arterial trees. Surgical or endovascular procedures were performed in nine patients: bypass graft in four, thrombectomy in four and catheter-directed thrombolysis in one. Conservative treatment with full anticoagulation was performed in two patients. All patients received pre- and post-operative anticoagulation. Except for one amputated case, clinical and vascular laboratory improvements were achieved in 10 patients. Mean follow-up period was 21 months (range 4-45 months). However, one patient, in whom re-vascularization surgery was performed successfully, discontinued warfarin therapy himself at 10 months after surgery, graft occlusion and limb loss occurred at 30 months after surgery. This initial experience suggests that protein C and/or S deficiency may be an independent risk factor for peripheral arterial insufficiency. Patients who present with peripheral arterial insufficiency and protein C and/or S deficiency demonstrate characteristic angiographic findings. Once the diagnosis of protein C and/or S deficiency is made, patients should be treated with life-long anticoagulation.

A novel plasmid-mediated beta-lactamase that hydrolyzes broad-spectrum cephalosporins in a clinical isolate of Klebsiella pneumoniae

A new extended-spectrum beta-lactamase with an isoelectric point (pI) of 6.2 was detected in Klebsiella pneumoniae F161 that was isolated from a patient with infection. This strain was highly resistant to the third or fourth generation cephalosporins such as ceftazidime, ceftriaxone, cefoperazone, and cefpirome. Analysis of this strain by the double disk diffusion test showed synergies between amoxicillin-clavulanate (AMX-CA) and cefotaxime, and AMX-CA and aztreonam, which suggested that this strain produced a extended-spectrum beta-lactamase (ESBL). Genetic analysis revealed that the resistance was due to the presence of a 9.4-kb plasmid, designated as pKP161, encoding for new beta-lactamase gene (bla). Sequence analysis showed that a new bla gene of pKP161 differed from bla(TEM-1) by three mutations leading to the following amino acid substitutions: Val84 --> Ile, Ala184 --> Val, and Gly238 --> Ser. These mutations have not been reported previously in the TEM type beta-lactamases produced by clinical strains. The novel beta-lactamase was overexpressed in E. coli and purified by ion exchange chromatography on Q-Sepharose and CM-Sepharose, and then further purified by gel filtration on Sehadex G-200. The catalytic activity of the purified beta-lactamase was confirmed by the nitrocefin disk.

Four new coumarin derivatives from Artemisia keiskeana

Four new coumarin monoterpene ethers, artekeiskeanols A-D (1-4), and three known coumarins, isofraxidin, fraxidin, and daphnoretin, were isolated from the whole plants of Artemisia keiskeana. All structures were determined from spectral data, and that of artekeiskeanol A (1) was confirmed by synthesis.

Milolides, new briarane diterpenoids from the western Pacific octocoral Briareum stechei

Eleven new briarane-type diterpene lactones, designated milolides (1--8, 10--12), together with four known diterpene lactones (9, 13--15), were isolated from the Micronesian octocoral Briareum stechei collected at Yap, Federated States of Micronesia. One aspect of the stereochemistry of one of the known compounds, solenolide C (9), is revised. Structures of the new compounds were determined from spectral data.

Inducible and constitutive expression using new plasmid and integrative expression vectors for Thermus sp

AIMS

To develop molecular tools and examine inducible and constitutive gene expression in Thermus thermophilus.

METHODS AND RESULTS

Two plasmid promoter probe vectors and an integrative promoter probe vector were constructed using a promoterless thermostable kanamycin nucleotidyltransferase (KmR) cassette. Three expression vectors were constructed based on a constitutive promoter J17, that functions in both Thermus and Escherichia coli. An inducible expression vector was constructed using the heat-shock inducible promoter (70 to 85 degrees C) from the dnaK gene of T. flavus, and the malate dehydrogenase gene (mdh) from T. flavus was cloned and expressed in both E. coli and T. thermophilus HB27.

CONCLUSION

This report describes the construction and use of improved promoter probe and expression vectors for use in Thermus species. The mdh gene can be used as a high temperature (85 degrees C) reporter gene for Thermus sp. The dnaK promoter is thermo-inducible.

SIGNIFICANCE AND IMPACT OF THE STUDY

The expression vectors and molecular tools described here are significant improvements over previously reported vectors for Thermus sp. The mdh gene and the thermo-inducible dnaK promoter will facilitate high temperature studies employing Thermus species.

Gene delivery into rat glomerulus using a mesangial cell vector

To develop an effective protocol of gene transfer into glomeruli, an ex vivo gene delivery system using rat mesangial cells (RMC) as a vector was examined. RMC genetically engineered with a retrovirus harboring the Escherichia coli beta-galactosidase gene was used to estimate the efficacy of gene delivery and the location of the cells within the kidney. The RMC expressing beta-galactosidase, RMCLZ1, was cultured in vitro and the cells were injected into the left kidney through the renal artery of a normal Sprague Dawley rat. At least 1 x 10(6) RMCLZ1 was required for effective gene delivery into glomeruli. One hour and 1, 4, and 14 d after injection, glomeruli were isolated from the left kidneys injected with the cells and the expression of beta-galactosidase in each glomeruli was evaluated. One hour and 1 d after injection, more than 90 and 80%, respectively, of glomeruli from the left kidney showed strong beta-galactosidase activity, while no activity of beta-galactosidase was found in the glomeruli from the right kidneys. The number of glomeruli stained by X-gal and the intensity decreased with time. Fourteen days after injection, about 35% of the glomeruli retained the RMCLZ1. X-gal and periodic acid-Schiff staining of frozen sections obtained 14 d after injection allowed the estimation of the site where the mesangial cells injected were located. The mesangial cells were found mainly in two different locations, the glomerular capillary and the mesangium. The majority (about 90%) of the mesangial cells were located in the glomerular capillary and about 9% of the cells were in the mesangial area. Occasionally, the positive staining was found in proximal tubules and the interlobular artery. Although additional methods are required for the site-specific targeting of the mesangial area, the ex vivo gene transfer to glomeruli is feasible and may be a useful tool for future investigations in the pathological mechanisms of glomerular injury.

Sesquiterpene quinols/quinones from the Micronesian sponge Petrosaspongia metachromia

Two new sesquiterpenes, pelorol (1) and 5-epi-smenospongine (2), and seven known ones (3-9) were isolated from the sponge Petrosaspongia metachromia, collected from Yap, Federated States of Micronesia. Their structures were determined from spectral data. Pelorol (1) possesses a new carbon skeleton.

Cloning, overexpression and purification of Bacillus subtilis elongation factor Tu in Escherichia coli

To establish the overexpression and one-step purification system of Bacillus subtilis elongation factor-Tu (EF-Tu), the EF-Tu gene was amplified with or without own ribosome binding site (rbs) by PCR and the only PCR product without rbs was subcloned successfully. For the expression of the EF-Tu gene cloned after PCR amplification, a constitutive expression system and inducible expression system with His6 tag at N-terminus or C-terminus, or glutathione-S-transferase (GST) fusion system were examined in E. coli and B. subtilis. Except GST fusion system in E. coli, however, all other trials were unsuccessful at the step of plasmid construction for the EF-Tu expression. The GST/EF-Tu fusion proteins were highly expressed by IPTG induction and obtained as both soluble and insoluble form. From the soluble GST/EF-Tu fusion protein, EF-Tu was obtained to near homogeneity by one-step purification with glutathione-sepharose affinity column chromatography followed by factor Xa treatment. The purified EF-Tu showed high GDP binding activity. These results indicate that the GST/EF-Tu fusion system is favorable to overexpression and purification of B. subtilis EF-Tu.

Methionyl adenylate analogues as inhibitors of methionyl-tRNA synthetase

Four stable analogues of methionyl adenylate (3-6) were designed as inhibitors of methionyl-tRNA synthetase and synthesized from 2',3'-isopropylideneadenosine. They strongly inhibited aminoacylation activity of methionyl-tRNA synthetases isolated from Escherichia coli, Mycobacterium tuberculosis, Saccharomyces cerevisiae and human. Among the microorganisms tested, however, these chemicals showed the growth inhibition effect only on E. coli.

Methionine analogues as inhibitors of methionyl-tRNA synthetase

A series of methionine analogues have been synthesized as inhibitors of methionyl-tRNA synthetase and evaluated for their inhibitory activities of E. coli methionyl-tRNA synthetase and bacterial growth. Among them, L-methionine hydroxamate 20 has proved to be the best inhibitor of the enzyme with Ki = 19 microM and showed a growth inhibition against E.coli JM 109, P. vulganis 6059 and C. freundii 8090.

A new prenylated flavonol from the roots of Sophora flavescens

A new prenylated flavonol, sophoflavescenol (1), together with five known flavonoids, kurarinol, kushenol K, kushenol H, trifolirhizin, and kuraidin, were isolated from the roots of Sophora flavescens. The structure of 1 was determined by spectroscopic analysis. Among the five known flavonoids, kurarinol, kushenol K, and kushenol H showed weak antiviral activity against Herpes simplex virus types I and II.

A furan derivative from Cornus officinalis

Dimethyltetrahydrofuran cis-2,5-dicarboxylate a furan derivative has been isolated from the fruits of Cornus officinalis, and it was isolated for the first time in the nature. The structure was elucidated by NMR spectroscopic techniques.

Isolation and identification of chondroitin sulfates from the mud snail

Chondroitin sulfates were isolated from the mud snail. For the quantitative analysis of enzymatic digestion products of isolated chondroitin sulfates, strong anion exchange-high performance liquid chromatography (SAX-HPLC) was performed. By the action of chondroitinase ABC, three unsaturated disaccharides 2-acetamide-2-deoxy-3-O-(beta-D-gluco-4-enepyranosyluronic acid)-D-galactose (delta Di-OS), 2-acetamide-2-deoxy-3-O-(beta-D-gluco-4-enepyranosyluronic acid)-6-O-sulfo-D-galactose (delta Di-6S) and 2-acetamide-2-deoxy-3-O-(beta-D-gluco-4-enepyranosyluronic acid)-4-O-sulfo-D-galactose (delta Di-4S) were produced from the mud snail chondroitin sulfates. The analysis showed that relative proportion of delta Di-OS/delta Di-6S/delta Di-4S was 58.7/3.1/38.2. The immunomodulating activity of chondroitin sulfate was examined by cell proliferation assay and these results suggest that it might be a immunosuppressant.

Purification and characterization of Cop, a protein involved in the copy number control of plasmid pE194

Cop protein has been overexpressed in Escherichia coli using a T7 RNA polymerase system. Purification to apparent homogeneity was achieved by the sequential chromatography on ion exchange, affinity chromatography, and reverse phase high performance liquid chromatography system. The molecular weight of the purified Cop was estimated as 6.1 kDa by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). But the molecular mass of the native state Cop was shown to be 19 kDa by an analytical high performance size exclusion chromatography, suggesting a trimer-like structure in 50 mM Tris-HCl buffer (pH 7.5) containing 100 mM NaCl. Cop protein was calculated to contain 39.1% alpha-helix, 16.8% beta-sheet, 17.4% turn, and 26.8% random structure. The DNA binding property of Cop protein expressed in E. coli was preserved during the expression and purification process. The isoelectric point of Cop was determined to be 9.0. The results of amino acid composition analysis and N-terminal amino acid sequencing of Cop showed that it has the same amino acid composition and N-terminal amino acid sequence as those deduced from its DNA sequence analysis, except for the partial removal of N-terminal methionine residue by methionyl-aminopeptidase in E. coli.

Prolyl endopeptidase inhibitors from caryophylli flos

Three prolyl endopeptidase inhibitors were isolated and identified as luteolin, quercetin and beta-sitosterol-3-O-beta-D-glucopyranoside with IC50 of 0.17, 0.19 and 27.5 ppm, respectively. The inhibition of two flavonoids were non-competitive with substrate. Twenty authentic flavonoids were tested in order to investigate structure-activity relationship. No significant relationship was found in them, however, catechol moiety of B-ring and 7-OH group in flavonoid skeleton were seemed to be responsible for the stronger activity.

Methyloxime-substituted aminopyrrolidine: a new surrogate for 7-basic group of quinolone

Novel fluoroquinolones containing oxime functionalized aminopyrrolidines have been synthesized. They were found to possess potent antibacterial activities against both Gram-negative and Gram-positive organisms, including methicillin resistant Staphylococcus aureus (MRSA). Among these compounds, LB20277 (compound 12) showed the most favorable in vivo efficacy and pharmacokinetic profile in animals. Based on these promising results, LB20277 was selected as a candidate for further evaluation.

Novel fluoroquinolone antibacterial agents containing oxime-substituted (aminomethyl)pyrrolidines: synthesis and antibacterial activity of 7-(4-(aminomethyl)-3-(methoxyimino)pyrrolidin-1-yl)-1-cyclopropyl-6- fluoro-4-oxo-1,4-dihydro[1,8]naphthyridine-3-carboxylic acid (LB20304)

New pyrrolidine derivatives, which bear an alkyloxime substituent in the 4-position and an aminomethyl substituent in the 3-position of the pyrrolidine ring, have been synthesized and coupled with various quinolinecarboxylic acids to produce a series of new fluoroquinolone antibacterials. These fluoroquinolones were found to possess potent antimicrobial activity against both Gram-negative and Gram-positive organisms, including methicillin resistant Staphylococcus aureus (MRSA). Variations at the C-8 position of the quinolone nucleus included fluorine, chlorine, nitrogen, methoxy, and hydrogen atom substitution. The activity imparted to the substituted quinolone nucleus by the C-8 substituent was in the order F (C5-NH2) > F (C5-H) > naphthyridine > Cl = OMe = H against Gram-positive organisms. In the case of Gram-negative strains, activity was in the order F (C5-NH2) > naphthyridine = F (C5-H) > H > Cl > OMe. The advantages provided by the newly introduced oxime group of the quinolones were clearly demonstrated by their comparison to a desoximino compound 30. In addition, the oxime moiety greatly improved the pharmacokinetic parameters of the novel quinolones. Among these compounds, compound 20 (LB20304) showed the best in vivo efficacy and pharmacokinetic profile in animals, as well as good physical properties. The MICs (microgram/mL) of LB20304, compound 30, and ciprofloxacin against several test organisms are as follows: S. aureus 6538p (0.008, 0.031, and 0.13), methicillin resistant S. aureus 241 (4, 16, and 128), Streptococcus epidermidis 887E (0.008, 0.016, and 0.13), methicillin resistant S. epidermidis 178 (4, 32, and 128), Enterococcus faecalis 29212 (0.063, 0.13, and 1), Pseudomonas aeruginosa 1912E (0.25, 0.5, and 0.13), Escherichia coli 3190Y (0.008, 0.016, and 0.008), Enterobacter cloacae P99 (0.008, 0.031, and 0.008), Actinobacter calcoaceticus 15473 (0.063, 0.13, and 0.25). On the basis of these promising results, LB20304 was selected as a candidate for further evaluation.

Artekeiskeanin A: a new coumarin-monoterpene ether from Artemisia keiskeana

A new coumarin-monoterpene ether, artekeiskeanin A (1) and two known coumarins, dracunculin (2) and scopoletin (3) were isolated from the aerial parts of Artemisia keiskeana. The structure of 1 was determined to be 7-(trans-8-oxogeranyloxy)-6-methoxycoumarin on the basis of spectroscopic studies.

In vitro and in vivo activities of LB10522, a new catecholic cephalosporin

In vitro activity of LB10522 was compared with those of cefpirome, ceftazidime, ceftriaxone, and cefoperazone against clinical isolates. Against gram-positive bacteria, LB10522 was most active among the compounds tested. It was fourfold more active than cefpirome against methicillin-susceptible Staphylococcus aureus and Enterococcus faecalis. LB10522 was highly effective against most members of the family Enterobacteriaceae tested. Ninety percent of isolates of Escherichia coli, Klebsiella oxytoca, Proteus vulgaris, Proteus mirabilis, and Salmonella spp. were inhibited at a concentration of < or = 0.5 micrograms/ml. These activities were comparable to those of cefpirome. Against Pseudomonas aeruginosa, LB10522 with a MIC at which 90% of the isolates are inhibited of 2 micrograms/ml was 16- and 32-fold more active than ceftazidime and ceftazidime against systemic infections caused by Staphylococcus aureus giorgio, Streptococcus pneumoniae III, Pseudomonas aeruginosa 1912E, Escherichia coli 851E, Proteus mirabilis 1315E, Serratia marcescens 1826E, and Acinetobacter calcoaceticus Ac-54. LB10522 was very resistant to hydrolysis by various beta-lactamases such as TEM-3, TEM-7, SHV-1, FEC-1, and P-99. LB10522 did not induce beta-lactamase in Enterobacter cloacae 1194E, although most of the reference cephalosporins acted as inducers of beta-lactamase in this strain. Time-kill study showed that LB10522, at concentrations of two or four times the MIC, had a rapid bactericidal activity against Staphylococcus aureus 6538p, Escherichia coli 851E, and Pseudomonas aeruginosa 1912E.

In vitro and in vivo evaluations of LB20304, a new fluoronaphthyridone

In vitro activity of LB20304 against 1,231 clinical isolates was evaluated and compared with those of ciprofloxacin, sparfloxacin, lomefloxacin, and ofloxacin. LB20304 demonstrated the most potent activity against gram-positive bacteria. It was 32- to 64-fold more active than ciprofloxacin against methicillin-susceptible Staphylococcus aureus, methicillin-resistant S. aureus, methicillin-resistant Staphylococcus epidermidis, and Streptococcus pneumoniae (penicillin G resistant). LB20304 was also highly active against most members of the family Enterobacteriaceae. Its activity was more potent than those of sparfloxacin, ofloxacin, and lomefloxacin and comparable to that of ciprofloxacin. The protective activities of LB20304 against systemic infections caused by gram-positive bacteria in mice were superior to those of ciprofloxacin and sparfloxacin. Against infections by gram-negative bacteria, LB20304 was slightly less active than ciprofloxacin.

In-vitro and in-vivo antibacterial activity of LB10517, a novel catechol-substituted cephalosporin with a broad antibacterial spectrum

LB10517 is a new injectable cephalosporin with a broad spectrum of antibacterial activity against Gram-positive and Gram-negative bacteria. LB10517 inhibited 90% of methicillin-susceptible Staphylococcus aureus (MSSA) at 0.25 mg/L (MIC90), and was 8-fold more active than cefpirome. LB10517 was two- or four-fold more active than cefpirome against methicillin-susceptible Staphylococcus epidermidis (MSSE), Streptococcus pyogenes and Enterococcus faecalis. Both methicillin-resistant S. aureus (MRSA) and methicillin-resistant S. epidermidis (MRSE) were highly resistant to all compounds. LB10517 activity against most Enterobacteriaceae was comparable to or greater than that of cefpirome, and it also showed high activity against Pseudomonas aeruginosa. In a mouse septicaemia model, LB10517 exhibited excellent protective effects. In a respiratory tract infection model, the protective effect of LB10517 was comparable to that of cefpirome and ceftazidime. It was highly stable to hydrolysis by beta-lactamases, showing better physiological efficiency for TEM-9 than the other test compounds. LB10517 had the most potent antibacterial activity against beta-lactamase producing resistant strains. LB10517 did not induce beta-lactamase production in Enterobacter cloacae 1194E.

Regulation of plasmid pE194 replication: control of cop-repF operon transcription by Cop and of repF translation by countertranscript RNA

The cop-rep region of plasmid pE194 contains two tandem structural genes, cop and repF, as well as the plus and minus origins of replication. The two structural genes comprise an operon whose expression is repressed by the binding of Cop protein to a 28-bp inverted complementary repeat sequence that overlaps the cop-repF promoter. From its position relative to the promoter and the experimentally determined footprint made by the Cop protein, the 28-bp inverted complementary repeat sequence is presumed to function as the cop operator. The intercistronic region between cop and repF is 80 nucleotides (nt) long and is transcribed bidirectionally: in the forward direction as part of the synthesis of the cop-repF message (ca. 900 nt), and in the reverse direction to yield a countertranscript ca. 65 nt long. The proposed countertranscript RNA (ctRNA) can form a single stem-and-loop structure that includes the single SphI sequence of plasmid pE194 as part of the loop-forming segment. Enlargement of the proposed loop from 6 to 14 nt by insertion of a SphI-BamHI adapter at the SphI site or contraction of the proposed loop down to 4 nt, by cutting with SphI followed by blunting with S1 nuclease, yields mutants with an increased copy number. By gel retardation and DNaseI footprinting analysis, Cop protein was shown to bind to the promoter region of cop; no binding by Cop protein at the 5' end of repF was detected. Two major transcripts were synthesized in vitro by using cop-repF region DNA as a template, the tandem cop-repF transcript, and the ctRNA. Addition of purified Cop protein to an vitro transcription reaction mixture reduced only the rate of cop-repF transcription but not that of ctRNA. These observations suggest that regulations of repF occurs at two levels: (i) with Cop protein acting as a repressor of cop-repF mRNA transcription and (ii) with ctRNA acting as a repressor of RepF translation.

Transcriptional attenuation control of ermK, a macrolide-lincosamide-streptogramin B resistance determinant from Bacillus licheniformis

ermK instructs bacteria to synthesize an erythromycin-inducible 23S rRNA methylase that confers resistance to the macrolide, lincosamide, and streptogramin B antibiotics. Expression of ermK is regulated by transcriptional attenuation, in contrast to other inducible erm genes, previously described, which are regulated translationally. The ermK mRNA leader sequence has a total length of 357 nucleotides and encodes a 14-amino-acid leader peptide together with its ribosome binding site. Additionally, the mRNA leader sequence can fold in either of two mutually exclusive conformations, one of which is postulated to form in the absence of induction and to contain two rho factor-independent terminators. Truncated transcription products ca. 210 and 333 nucleotides long were synthesized in the absence of induction, both in vivo and in vitro, as predicted by the transcriptional attenuation model; run-off transcription in vitro with rITP favored the synthesis of the full-length run-off transcript over that of the 210- and 333-nucleotide truncated products. Northern (RNA) blot analysis of transcripts synthesized in vivo in the absence of erythromycin indicated that transcription terminated at either of the two inverted complementary repeat sequences in the leader that were postulated to serve as rho factor-independent terminators; moreover, no full-length transcripts were detectable in the uninduced samples. In contrast, full-length (ca. 1,200-nucleotide) transcripts were only detected in RNA samples synthesized in vivo in the presence of erythromycin. Full-length transcripts formed in the absence of induction from transcriptional readthrough past the two proposed transcription terminators would fold in a way that would sequester the ribosome binding site together with the first two codons of the ErmK methylase, reducing its efficiency in translation. This feature could therefore provide additional control of expression in the absence of induction; however, such regulation, if operative, would act only secondarily, both in time and place, relative to transcriptional control. Analysis by reverse transcriptase mapping of in vivo transcripts from two primers that bracket the transcription terminator responsible for the 210-nucleotide truncated fragment supports the transcriptional attenuation model proposed and suggests further that the synthesis of the ermK message is initiated constitutively upstream of the proposed terminator but completed inductively downstream of this site.