bluuebunny/crossref_metadata_2025 huggingface dataset:
Genetic identity of aminoglycoside-resistance genes in Escherichia coli isolates from human and animal sources
Authors: Ho Pak-Leung , Wong River C. , Lo Stephanie W. , Chow Kin-Hung , Wong Samson S. , Que Tak-Lun
Published: February 2010

A bacterial collection (n=249) obtained in Hong Kong from 2002 to 2004 was used to investigate the molecular epidemiology of aminoglycoside resistance among Escherichia coli isolates from humans and food-producing animals. Of these, 89 isolates were gentamicin-sensitive (human n=60, animal n=29) and 160 isolates were gentamicin-resistant (human n=107, animal n=53). Overall, 84.1 % (90/107) and 75.5 % (40/53) of the gentamicin-resistant isolates from human and animal sources, respectively, were found to possess the aacC2 gene. The aacC2 gene for 20 isolates (10 each for human and animal isolates) was sequenced. Two alleles were found that were equally distributed in human and animal isolates. PFGE showed that the gentamicin-resistant isolates exhibited diverse patterns with little clonality. In some isolates, the aacC2 gene was encoded on large transferable plasmids of multiple incompatibility groups (IncF, IncI1 and IncN). An IncFII plasmid of 140 kb in size was shared by one human and three animal isolates. In summary, this study showed that human and animal isolates share the same pool of resistance genes.
Characterization of Legionella pneumophila isolates from patients in Japan according to serogroups, monoclonal antibody subgroups and sequence types
Authors: Amemura-Maekawa Junko , Kura Fumiaki , Helbig Jürgen H. , Chang Bin , Kaneko Akiko , Watanabe Yuko , Isobe Junko , Nukina Masafumi , Nakajima Hiroshi , Kawano Kimiko , Tada Yuki , Watanabe Haruo ,   the Working Group for in Japan
Published: February 2010

We collected 86 unrelated clinicalLegionella pneumophilastrains that were isolated in Japan during the period 1980–2008. Most (80.2 %) belonged to serogroup 1, followed by serogroups 5, 3 and 2. Interestingly, the patients withL. pneumophilaserogroup 1 had a significantly higher male-to-female ratio (12.4) than the patients with otherL. pneumophilaserogroups (2.0) (OR, 10.5; 95 % CI, 2.5–44.5). When the serogroup 1 strains were analysed by monoclonal antibody (mAb) typing, the most prevalent subgroup was Benidorm (34.9 % of all isolates). Moreover, 79.7 % of the serogroup 1 isolates were bound by mAb 3/1, which recognizes the virulence-associated epitope. When all 86 isolates were subjected to sequence-based typing (SBT) using seven loci, they could be divided into 53 sequence types (STs). The ST with the most isolates (seven) was ST1, to which most isolates from patients and environments around the world belong. However, six of the seven ST1 isolates were isolated before 1994. Other major STs were ST306 (n=6), ST120 (n=5) and ST138 (n=5). All ST306 and ST138 isolates, except for one isolate (ST306), were suspected or confirmed to be derived from bath water, which suggests that these strains prefer bath habitats. The sources of all ST1 and ST120 isolates remain unclear. By combining the SBT and mAb data, the 86 isolates could be divided into 59 types (discrimination index, 0.984). This confirms the usefulness of this combination in epidemiological studies.
Structure of the O-antigen of Salmonella O66 and the genetic basis for similarity and differences between the closely related O-antigens of Escherichia coli O166 and Salmonella O66
Authors: Liu Bin , Perepelov Andrei V. , Li Dan , Senchenkova Sof'ya N. , Han Yanfang , Shashkov Alexander S. , Feng Lu , Knirel Yuriy A. , Wang Lei
Published: February 2010

O-antigen is a component of the outer membrane of Gram-negative bacteria and is one of the most variable cell surface constituents, leading to major antigenic variability. The O-antigen forms the basis for bacterial serotyping. In this study, the O-antigen structure of Salmonella O66 was established, which differs from the known O-antigen structure of Escherichia coli O166 only in one linkage (most likely the linkage between the O-units) and O-acetylation. The O-antigen gene clusters of Salmonella O66 and E. coli O166 were found to have similar organizations, the only exception being that in Salmonella O66, the wzy gene is replaced by a non-coding region. The function of the wzy gene in E. coli O166 was confirmed by the construction and analysis of deletion and trans-complementation mutants. It is proposed that a functional wzy gene located outside the O-antigen gene cluster is involved in Salmonella O66 O-antigen biosynthesis, as has been reported previously in Salmonella serogroups A, B and D1. The sequence identity for the corresponding genes between the O-antigen gene clusters of Salmonella O66 and E. coli O166 ranges from 64 to 70 %, indicating that they may originate from a common ancestor. It is likely that after the species divergence, Salmonella O66 got its specific O-antigen form by inactivation of the wzy gene located in the O-antigen gene cluster and acquisition of two new genes (a wzy gene and a prophage gene for O-acetyl modification) both residing outside the O-antigen gene cluster.
The σ R regulon of Streptomyces coelicolor A3(2) reveals a key role in protein quality control during disulphide stress
Authors: Kallifidas Dimitris , Thomas Derek , Doughty Phillip , Paget Mark S. B.
Published: February 2010

Diamide is an artificial disulphide-generating electrophile that mimics an oxidative shift in the cellular thiol–disulphide redox state (disulphide stress). The Gram-positive bacteriumStreptomyces coelicolorsenses and responds to disulphide stress through theσR–RsrA system, which comprises an extracytoplasmic function (ECF) sigma factor and a redox-active anti-sigma factor. Known targets that aid in the protection and recovery from disulphide stress include the thioredoxin system and genes involved in producing the major thiol buffer mycothiol. Here we determine the global response to diamide in wild-type andsigRmutant backgrounds to understand the role ofσRin this response and to reveal additional regulatory pathways that allow cells to cope with disulphide stress. In addition to thiol oxidation, diamide was found to cause protein misfolding and aggregation, which elicited the induction of the HspR heat-shock regulon. Although this response isσR-independent,σRdoes directly control Clp and Lon ATP-dependent AAA(+) proteases, which may partly explain the reduced ability of asigRmutant to resolubilize protein aggregates.σRalso controlsmsrAandmsrBmethionine sulphoxide reductase genes, implying thatσR–RsrA is responsible for the maintenance of both cysteine and methionine residues during oxidative stress. This work shows that theσR–RsrA system plays a more significant role in protein quality control than previously realized, and emphasizes the importance of controlling the cellular thiol–disulphide redox balance.
Salmonella pathogenicity island 1 (SPI-1) type III secretion of SopD involves N- and C-terminal signals and direct binding to the InvC ATPase
Authors: Boonyom R. , Karavolos M. H. , Bulmer D. M. , Khan C. M. A.
Published: February 2010

Salmonella enterica serovar Typhimurium (S. Typhimurium) is an important pathogen and a causative agent of gastroenteritis. During infection, S. Typhimurium assembles molecular-needle complexes termed type III secretion (T3S) systems to translocate effector proteins from the bacterial cytoplasm directly into the host cell. The T3S signals that direct the secretion of effectors still remain enigmatic. SopD is a key T3S effector contributing to the systemic virulence of S. Typhimurium and the development of gastroenteritis. We have scrutinized the distribution of the SopD T3S signals using in silico analysis and a targeted deletion approach. We show that amino acid residues 6–10 act as the N-terminal secretion signal for Salmonella pathogenicity island 1 (SPI-1) T3S. Furthermore, we show that two putative C-terminal helical regions of SopD are essential for its secretion and also help prevent erroneous secretion through the flagellar T3S machinery. In addition, using protein–protein interaction assays, we have identified an association between SopD and the SPI-1 T3S system ATPase, InvC. These findings demonstrate that T3S of SopD involves multiple signals and protein interactions, providing important mechanistic insights into effector protein secretion.
Functional characterization of the Mycobacterium tuberculosis serine/threonine kinase PknJ
Authors: Jang Jichan , Stella Alexandre , Boudou Frédéric , Levillain Florence , Darthuy Eliette , Vaubourgeix Julien , Wang Chongzhen , Bardou Fabienne , Puzo Germain , Gilleron Martine , Burlet-Schiltz Odile , Monsarrat Bernard , Brodin Priscille , Gicquel Brigitte , Neyrolles Olivier
Published: February 2010

Eukaryotic-like Ser/Thr protein kinases (STPKs) are present in many bacterial species, where they control various physiological and virulence processes by enabling microbial adaptation to specific environmental signals. PknJ is the only member of the 11 STPKs identified inMycobacterium tuberculosisthat still awaits characterization. Here we report that PknJ is a functional kinase that forms dimersin vitro, and contains a single transmembrane domain. Using a high-density peptide-chip-based technology, multiple potential mycobacterial targets were identified for PknJ. We confirmed PknJ-dependent phosphorylation of four of these targets: PknJ itself, which autophosphorylates at Thr168, Thr171and Thr173residues; the transcriptional regulator EmbR; the methyltransferase MmaA4/Hma involved in mycolic acid biosynthesis; and the dipeptidase PepE, whose encoding gene is located next topknJin the mycobacterial genome. Our results provide a number of candidate phospho-targets for PknJ and possibly other mycobacterial STPKs that could be studied to investigate the role of STPKs inM. tuberculosisphysiology and virulence.
Two new silicate structures based on a rhodesite-type heteropolyhedral microporous framework
Authors: Cadoni Marcella , Ferraris Giovanni
Published: February 2010

Two new members of the mero-plesiotype rhodesite series [Sr2Na2(Si8O19)·4H2O, abbreviated as TR09; SrNa4(Si8O19)·4H2O, TR10] have been hydrothermally synthesized in Teflon-lined autoclaves at 503 K and structurally characterized using X-ray diffraction single-crystal data. The crystal structures were solved by direct methods and refined to R = 0.021 [TR09; 3317 reflections with I
o > 2σ(I
o)] and R = 0.033 [TR10; 5007 reflections with I
o > 2σ(I
o)]. Both structures are based on a rhodesite-type microporous heteropolyhedral framework, where two types of channels are within the double silicate layer that alternates with an `octahedral' O sheet. The large Sr2+ cation constrains to the roughly ellipsoidal shape of the channels. The H2O molecules are located both in the O sheets and in the channels, where they are loosely hydrogen bonded. The crystal-chemical features that allow flexibility to the rhodesite-type microporous heteropolyhedral framework and make it interesting for possible technological applications are discussed.
Maximum entropy method and charge flipping, a powerful combination to visualize the true nature of structural disorder from in situ X-ray powder diffraction data
Authors: Samy Ali , Dinnebier Robert E. , van Smaalen Sander , Jansen Martin
Published: February 2010

In a systematic approach, the ability of the Maximum Entropy Method (MEM) to reconstruct the most probable electron density of highly disordered crystal structures from X-ray powder diffraction data was evaluated. As a case study, the ambient temperature crystal structures of disordered α-Rb2[C2O4] and α-Rb2[CO3] and ordered δ-K2[C2O4] were investigated in detail with the aim of revealing the `true' nature of the apparent disorder. Different combinations of F (based on phased structure factors) and G constraints (based on structure-factor amplitudes) from different sources were applied in MEM calculations. In particular, a new combination of the MEM with the recently developed charge-flipping algorithm with histogram matching for powder diffraction data (pCF) was successfully introduced to avoid the inevitable bias of the phases of the structure-factor amplitudes by the Rietveld model. Completely ab initio electron-density distributions have been obtained with the MEM applied to a combination of structure-factor amplitudes from Le Bail fits with phases derived from pCF. All features of the crystal structures, in particular the disorder of the oxalate and carbonate anions, and the displacements of the cations, are clearly obtained. This approach bears the potential of a fast method of electron-density determination, even for highly disordered materials. All the MEM maps obtained in this work were compared with the MEM map derived from the best Rietveld refined model. In general, the phased observed structure factors obtained from Rietveld refinement (applying F and G constraints) were found to give the closest description of the experimental data and thus lead to the most accurate image of the actual disorder.
Superspace description of the homologous series Ga2O3(ZnO)m
Authors: Michiue Yuichi , Kimizuka Noboru
Published: February 2010

A unified description for the structures of the homologous series Ga2O3(ZnO)m, gallium zinc oxide, is presented using the superspace formalism. The structures were treated as a compositely modulated structure consisting of two subsystems. One is constructed with metal ions and the other with O ions. The ideal model is given, in which the displacive modulations of ions are well described by the zigzag function with large amplitudes. Alternative settings are also proposed which are analogous to the so-called modular structures. The validity of the model has been confirmed by refinements for phases withm= 6 andm= 9 in the homologous series. A few complex phenomena in real structures are taken into account by modifying the ideal model.
New RE microporous heteropolyhedral silicates containing 41516182tetrahedral sheets
Authors: Cadoni Marcella , Cheah Yan Ling , Ferraris Giovanni
Published: February 2010

Four heteropolyhedral microporous silicates,A3RESi6O15·2.25H2O, crystallizing in theCmm2 space group and based on 41516182tetrahedral sheets [A3= Na2.74K0.26, RE = Ce, abbreviated as TR05; TR06:A3= Na2.72K0.28, RE = La; TR07:A3= Na3, RE = La; TR08:A3= Na2.74(H3O)0.26, RE = La0.68Eu0.32] have been hydrothermally synthesized in Teflon-lined autoclaves at 503 K and structurally characterized using X-ray diffraction single-crystal data. Except for TR05, diffraction data have been collected on {001} twins by merohedry. The four structures are isotypic and based on strongly corrugated 41516182silicate sheets interconnected along [010] by seven-coordinated RE polyhedra to form a microporous heteropolyhedral framework. The framework is crossed by three systems of ellipsoidal channels that host H2O molecules and alkaline ions. The channels run either parallel or perpendicular to the silicate sheets; the largest effective channel width is 4.7 × 2 Å. In TR08 some (H3O)+replaces alkalis. Although the H atoms have not been localized, the configuration of the hydrogen bonding has been deduced from bond lengths and angles.
Epidemiological survey of foot diseases in Japan: Results of 30 000 foot checks by dermatologists
Authors: WATANABE Shinichi , HARADA Takashi , HIRUMA Masataro , IOZUMI Ken , KATOH Takuro , MOCHIZUKI Takashi , NAKA Wataru ,   JAPAN FOOT WEEK GROUP
Published: February 2010

There has been no epidemiological survey of foot diseases in Japan. In this study we determined the prevalence of foot diseases, especially tinea pedis (TP) and tinea unguium (TU) in Japan. We conducted a randomized survey of outpatients who visited a dermatologist during the third week of May in 1999, 2000 and 2006. The most frequently reported condition was “fungal infection” in 8737 (40.0%) of 21 820 patients in 1999/2000, and 3848 (49.4%) of 7783 patients in 2006. The patients who visited a dermatologist for reasons other than superficial fungal infection but were diagnosed with TP or TU comprised 18.6% of the study population in 2000 and 24.1% in 2006. Of the patients with TP or TU, 63.2% used topical medication only. This survey showed that often patients are not aware of fungal infections and that their treatment is sometimes insufficient. Dermatologists should actively examine and treat patients with TP and TU.
Association of human leukocyte antigen class II alleles with pemphigus vulgaris in a Turkish population
Authors: TUNCA Mustafa , MUSABAK Ugur , SAGKAN Rahşan Ilikci , KOC Erol , AKAR Ahmet
Published: February 2010

Pemphigus vulgaris (PV) is a severe autoimmune blistering skin disorder that is strongly associated with major histocompatibility complex class II alleles. Human leukocyte antigen (HLA) subtypes vary with racial/ethnic backgrounds. The purpose of this study was to determine the association of HLA class II alleles and haplotypes with PV in Turkish patients. Twenty‐five patients with PV and 113 healthy transplant donors were genotyped for HLA class II alleles. HLA DNA typing was performed by the polymerase chain reaction/sequence specific primer method. The frequency of HLA DRB1*04 allele was 68.00% in patients compared to 30.97% in controls (P = 0.0012) and the frequency of HLA DRB1*14 allele was 32.00% in the patient group compared to 8.85% in the control group (P = 0.0054). Also, the frequency of HLA DRB1*04/DQB1*03 and HLA DRB1*14/DQB1*05 haplotypes in PV patients was significantly higher than controls (32.0% vs 6.2%, χ2 = 28.142, P < 0.001; and 16% vs 2.7%, χ2 = 15.143, P = 0.001, respectively). A preventive allele or haplotype for the manifestation of PV has not been identified in this study. Our findings suggest that HLA DRB1*04 and DRB1*14 alleles, and HLA DRB1*04/DQB1*03 and HLA DRB1*14/DQB1*05 haplotypes are genetic markers for general susceptibility to PV in the Turkish population.
Risk factors associated with having psoriatic arthritis in patients with cutaneous psoriasis
Authors: TEY Hong Liang , EE Hock Leong , TAN Andy SL , THENG Thiam Seng , WONG Su Ni , KHOO Shih Wee
Published: February 2010

The aim of this study was to determine if the following characteristics were associated with the presence of psoriatic arthritis in a sample of psoriasis patients: race, family history of psoriasis and psoriatic arthritis, age of onset of psoriasis, smoking, alcohol consumption and the maximum body surface area (BSA) affected by psoriasis. This was a case–control study involving 400 psoriasis patients who attended the Psoriasis and Photo‐medicine clinic in the National Skin Center of Singapore over a 1‐year period. Cases were psoriasis patients with psoriatic arthritis while controls were psoriasis patients without psoriatic arthritis. The diagnosis of psoriatic arthritis was made by rheumatologists and participants completed a self‐administered standardized questionnaire. The maximum BSA involved was determined from the case notes. Psoriatic arthritis was not significantly associated with sex, race, age of onset of psoriasis, a family history of psoriasis, smoking and alcohol consumption but was significantly associated with a family history of psoriatic arthritis (P < 0.001) and the maximum body surface involved (P = 0.05). Using multivariate analysis to control for variables, the presence of psoriatic arthritis was significantly associated with a family history of psoriatic arthritis (odds ratio [OR] = 20.5; 95% confidence interval [CI] = 2.49–169.10) and the maximum BSA involved (OR = 2.52; 95% CI = 1.33–4.75). Indian psoriatic patients were more likely to have psoriatic arthritis compared to the other races. A family history of psoriatic arthritis and a greater maximum body surface involved may be associated with having psoriatic arthritis in this study population of psoriasis patients.
Adalimumab in Japanese patients with moderate to severe chronic plaque psoriasis: Efficacy and safety results from a Phase II/III randomized controlled study
Authors: ASAHINA Akihiko , NAKAGAWA Hidemi , ETOH Takafumi , OHTSUKI Mamitaro ,   THE ADALIMUMAB M04‐688 STUDY GROUP
Published: February 2010

Incidence of psoriasis vulgaris in Asians is estimated at 0.05–0.3%. Studies in North America and Europe demonstrated that adalimumab, a fully human, recombinant, immunoglobulin G1 monoclonal antibody, was efficacious and well‐tolerated in patients with chronic plaque psoriasis. This 24‐week, placebo‐controlled study evaluated the efficacy and safety of three different dosing regimens of adalimumab in Japanese patients with moderate to severe chronic plaque psoriasis (n = 169). Patients were randomized to receive adalimumab 40 mg every other week (eow), adalimumab 80‐mg loading dose at week 0 followed by adalimumab 40 mg eow starting at week 2, adalimumab 80 mg eow, or placebo eow given as s.c. injections. The primary efficacy endpoint was the percentage of patients achieving a 75% or greater improvement in Psoriasis Area and Severity Index (PASI 75) score at week 16. At week 16, PASI 75 response rates were significantly greater for all three adalimumab groups (40 mg eow: 57.9%, P < 0.001; 40 mg eow plus loading dose: 62.8%, P < 0.001; 80 mg eow: 81.0%, P < 0.001) versus placebo (4.3%). As early as week 4, the 40‐mg eow plus loading dose and 80‐mg eow groups achieved significantly greater PASI 75 response rates compared with placebo. Injection‐site reactions and hepatic events occurred in greater percentages of adalimumab‐treated patients compared with placebo. Adalimumab therapy demonstrated efficacy and safety at all three dosage regimens. Rapid response rate in patients receiving 40 mg eow plus loading dose supports using an 80‐mg loading dose in the treatment of psoriasis.
From anti‐p200 pemphigoid to anti‐laminin γ1 pemphigoid
Authors: DAINICHI Teruki , KOGA Hiroshi , TSUJI Takako , ISHII Norito , OHYAMA Bungo , UEDA Akihiro , NATSUAKI Yohei , KARASHIMA Tadashi , NAKAMA Takekuni , YASUMOTO Shinichiro , ZILLIKENS Detlef , HASHIMOTO Takashi
Published: February 2010

Anti‐laminin γ1 pemphigoid is an autoimmune subepidermal bullous disease first described in 1996, and has been distinct from previously known subepidermal blistering diseases, such as bullous pemphigoid and epidermolysis bullosa acquisita. Circulating autoantibodies of the patients do not react to any known autoantigen of the skin, but react to a 200‐kDa molecule (p200) from dermal extracts. The identity of p200 was unmasked as laminin γ1, an extracellular matrix glycoprotein composing several forms of laminin heterotrimers. We renamed this disease from the previously used anti‐p200 pemphigoid to anti‐laminin γ1 pemphigoid, a new entity of an autoimmune bullous disease. In this decade, we have experienced over 70 cases of this disease. Although the number of the cases of anti‐laminin γ1 pemphigoid is half as many as the number of definitely diagnosed cases of epidermolysis bullosa acquisita in the same duration, a considerable number of the cases could be clinically misdiagnosed as epidermolysis bullosa acquisita. Unveiling the pathogenicity and development of a useful diagnostic method is necessary for appropriate management of this new disease.
Pretibial dystrophic epidermolysis bullosa with localized cutaneous amyloidosis: Coincidental or secondary amyloidosis?
Authors: AOKI Mikako , NIIMI Yayoi , ISHIKO Akira , KAWANA Seiji
Published: February 2010

Here, we describe the case of a patient with pretibial dystrophic epidermolysis bullosa (PDEB) with amyloid deposition. The patient was a 40‐year‐old Japanese woman who presented a blistering eruption in the pretibial area with flat violaceous‐brown lichenoid papules. The histology of the blister revealed a subepidermal bulla with antibodies bound to basement membrane antigens on the blister roof by immunoflourescent mapping. Electron microscopy revealed a blister cleavage plane below the lamina densa. The histology of the lichenoid papules showed amyloid deposition in the papillary dermis. Because it was confined to just beneath the bulla base of the blister specimen, the amyloid deposition may have been derived from degenerated keratinocytes induced by damage to the epidermal–dermal junction due to blister formation in PDEB in this case. PDEB, in general, is often misdiagnosed as lichen amyloidosis; however, some PDEB cases could actually be associated with amyloid deposition.
What’s new in i.v. immunoglobulin therapy and pemphigus: High‐dose i.v. immunoglobulin therapy and its mode of action for treatment of pemphigus
Authors: AOYAMA Yumi
Published: February 2010

High‐dose i.v. immunoglobulin (HD‐IVIG) has several distinguishing therapeutic characteristics including rapid clearance of pathogenic antibody, non‐immunosuppressive and less adverse effects. In 2009, the first multicenter, randomized, placebo‐controlled, double‐blind trial of HD‐IVIG for pemphigus was conducted in Japan. This clinical trial has proved that 400 mg/kg per day for 5 days administration of IVIG is effective as an adjuvant therapy with systemic steroid therapy and/or immunosuppressive agents. Among the several mechanisms to explain the mode of action of IVIG, several lines of evidence have suggested that neonatal Fc receptor for immunoglobulin (Ig)G (FcRn) plays an important role for rapid clearance of pathogenic antibody in pemphigus induced by HD‐IVIG. Additionally, the long suppression of IgG production induced by HD‐IVIG has been observed in some cases. Taking these characteristics into consideration, HD‐IVIG, which leads to decreased pathogenic IgG, is recommended to use in combination with oral corticosteroids or other immunosuppressants, which suppress the production of pathogenic IgG. This review summerizes experimental and clinical evidences for major mechanism of action in HD‐ IVIG and how to use it.
Immunoglobulin A antibodies against desmoglein 1, envoplakin, periplakin and BP230 in a patient with atypical bullous pemphigoid
Authors: YAMAKI Fumi , MAYUZUMI Nobuyasu , IKEDA Shigaku , HASHIMOTO Takashi
Published: February 2010

Bullous pemphigoid is an autoimmune subepidermal blistering disease associated with autoantibodies against BP180 and BP230. We report herein a rare case of bullous pemphigoid with newly formed annular erythematous lesions when bullous skin lesions were in remission. Various immunological studies revealed immunoglobulin (Ig)A antibodies against desmoglein 1, envoplakin, periplakin and BP230 in addition to IgG antibodies against BP180 and BP230. These clinical and immunological changes in a patient are a rare event, suggesting an epitope‐spreading phenomenon.
Influence ofColophospermum mopanecanopy cover on litter decomposition and nutrient dynamics in a semi‐arid African savannah
Authors: Mlambo Donald , Mwenje Eddie
Published: February 2010

The objective of this study was to investigate the influence of mopane canopy cover on litter decomposition in a semi‐arid African savannah. We used a randomized block design with five blocks of 100 × 100 m demarcated in a 10‐ha pocket of open mopane woodland. Litterbags were placed beneath large (8.3 m crown diameter) and small mopane trees (2.7 m crown diameter) and in the intercanopy area. Decomposition was fastest in the intercanopy area exposed to solar radiation (k = 0.35 year−1), intermediate beneath small trees (k = 0.28 year−1) and slowest beneath large trees (k = 0.23 year−1). Soil temperatures beneath small and large trees were 3–5 and 6–9°C lower than in the intercanopy area, respectively. Bacterial and fungal counts were significantly higher (P < 0.05) beneath large than small trees and in the intercanopy area. The amount of N and P released did not vary significantly among sampling sites. Soil moisture in the dry season was similar among sampling sites but rainy‐season soil moisture was significantly greater (P < 0.05) beneath large than small trees and in the intecanopy area. Mopane canopy cover retarded litter decomposition suggesting that photodegradation could be an important factor controlling carbon turnover in semi‐arid African savannahs.
Exposure to oral oxycodone is increased by concomitant inhibition of CYP2D6 and 3A4 pathways, but not by inhibition of CYP2D6 alone
Authors: Grönlund Juha , Saari Teijo I. , Hagelberg Nora M. , Neuvonen Pertti J. , Olkkola Klaus T. , Laine Kari
Published: February 2010

WHAT IS ALREADY KNOWN ABOUT THIS SUBJECT

• Oxycodone is an opioid analgesic that is metabolized mainly in the liver by cytochrome P450 (CYP) 2D6 and 3A4 enzymes.

• So far, the effects of CYP2D6 or CYP3A4 inhibitors on the pharmacokinetics of oxycodone in humans have not been systematically studied.

WHAT THIS STUDY ADDS

• Drug interactions arising from CYP2D6 inhibition most likely have minor clinical importance for oral oxycodone.

• When both of CYP2D6 and CYP3A4 pathways are inhibited, the exposure to oral oxycodone is increased substantially.

AIM

The aim of this study was to find out whether the inhibition of cytochrome P450 2D6 (CYP2D6) with paroxetine or concomitant inhibition of CYP2D6 and CYP3A4 with paroxetine and itraconazole, altered the pharmacokinetics and pharmacological response of orally administered oxycodone.

METHODS

A randomized placebo‐controlled cross‐over study design with three phases was used. Eleven healthy subjects ingested 10 mg of oral immediate release oxycodone on the fourth day of pre‐treatment with either placebo, paroxetine (20 mg once daily) or paroxetine (20 mg once daily) and itraconazole (200 mg once daily) for 5 days. The plasma concentrations of oxycodone and its oxidative metabolites were measured for 48 h, and pharmacological (analgesic and behavioural) effects were evaluated.

RESULTS

Paroxetine alone reduced the area under concentration–time curve (AUC(0,0–48 h)) of the CYP2D6 dependent metabolite oxymorphone by 44% (P < 0.05), but had no significant effects on the plasma concentrations of oxycodone or its pharmacological effects when compared with the placebo phase. When both oxidative pathways of the metabolism of oxycodone were inhibited with paroxetine and itraconazole, the mean AUC(0,∞) of oxycodone increased by 2.9‐fold (P < 0.001), and its Cmax by 1.8‐fold (P < 0.001). Visual analogue scores for subjective drug effects, drowsiness and deterioration of performance were slightly increased (P < 0.05) after paroxetine + itraconazole pre‐treatment when compared with placebo.

CONCLUSIONS

Drug interactions arising from CYP2D6 inhibition most likely have minor clinical importance for oral oxycodone if the function of the CYP3A4 pathway is normal. When both CYP2D6 and CYP3A4 pathways are inhibited, the exposure to oral oxycodone is increased substantially.
Oversight: a retrospective study of biochemical monitoring in patients beginning antihypertensive drug treatment in primary care
Authors: Coleman Jamie J. , McDowell Sarah E. , Evans Stephen J. W. , Gill Paramjit S. , Ferner Robin E.
Published: February 2010

WHAT IS ALREADY KNOWN ABOUT THIS SUBJECT

• Guidelines recommend biochemical monitoring of patients treated with antihypertensive agents, although there is little primary evidence for these recommendations.

WHAT THIS STUDY ADDS

• Patients treated for hypertension in general practice often have no biochemical tests before, or in the 6 months after, starting drug treatment.

AIMS

Guidelines on the management of hypertension have recommended baseline testing of serum electrolyte and creatinine concentrations before treatment since the 1990s. We wished to examine the extent of laboratory monitoring in patients with newly diagnosed hypertension and newly treated with antihypertensive drugs.

METHODS

We carried out a retrospective analysis of 74 096 patients in the General Practice Research Database (GPRD) aged 18 years and older with newly diagnosed hypertension and prescribed a single antihypertensive agent. We determined the number of patients with a laboratory test for serum electrolyte and creatinine (or urea) concentrations prior to the first antihypertensive drug prescription and in the 6 months after and patient factors associated with subsequent monitoring.

RESULTS

Thirty‐four thousand nine hundred and forty‐seven patients (47%) had at least one biochemical test in the 12 months prior to beginning antihypertensive treatment, and 26 946 (36%) had at least one biochemical monitoring test in the 6 months after beginning antihypertensive treatment. Thirteen thousand five hundred and four (18%) had both baseline and monitoring tests. Baseline tests were normal in 11 671 patients (86%), of whom 10 213 (88%) had normal tests at first monitoring. Monitoring was significantly more likely in patients treated with ACE inhibitors than thiazides (adjusted OR 1.90; 95% CI 1.80, 2.00), older patients (adjusted OR 1.23; 95% CI 1.11, 1.36) [individuals aged 80–89 years compared with <40 years], and patients with diabetes mellitus (adjusted OR 2.03; 95% CI 1.91, 2.16).

CONCLUSION

Biochemical testing at baseline and monitoring after starting treatment is often omitted in newly diagnosed hypertensive patients. When both are tested, one in eight normal results becomes abnormal.
Oestrogen‐related receptor alpha inverse agonist XCT‐790 arrests A549 lung cancer cell population growth by inducing mitochondrial reactive oxygen species production
Authors: Wang J. , Wang Y. , Wong C.
Published: February 2010

Objective:  Although oestrogen‐related receptor α (ERRα) is primarily thought to regulate energy homeostasis, it also serves as a prognostic marker for cancer. The aim of this study was to investigate any connection between ERRα activity and cell population growth.

Materials and methods:  XCT‐790, an ERRa specific inverse agonist, was employed to suppress ERRa activity in human non‐small cell lung cancer cells (NSCLC) A549. Gene expressions were detected using quantitative real‐time PCR and Western blot analysis. Mitochondrial mass, membrane potential and reactive oxygen species (ROS) production were measured by staining with Mitotracker green, JC‐1 and CM‐H2DCFDA dyes respectively. Rate of progression through the tricarboxylic acid (TCA) cycle was analysed by measuring activities of citrate synthase and succinate dehydrogenase. Cell cycle analysis was performed by using flow cytometry.

Results:  We found that XCT‐790 treatment reduced mitochondrial mass but enhanced mitochondrial ROS production by increasing rate through the TCA cycle, elevating mitochondrial membrane potential (ΔΨm) and down‐regulating expression of superoxide dismutase. It was further demonstrated that XCT‐790‐induced ROS modulated p53 and Rb signalling pathways and suppressed cell replication.

Conclusions:  ERRα affects cell cycle mechanisms through modulating mitochondrial mass and function. Dysregulation of this essential pathway leads to elevation in mitochondrial ROS production, which in turn modulates activities of tumour suppressors, resulting in cell cycle arrest.
γ‐secretase inhibitor induces adipogenesis of adipose‐derived stem cells by regulation of Notch and PPAR‐γ
Authors: Huang Y. , Yang X. , Wu Y. , Jing W. , Cai X. , Tang W. , Liu L. , Liu Y. , Grottkau B. E. , Lin Y.
Published: February 2010

Objective:  To determine the inhibitory effect and mechanism of Notch signalling on adipogenesis of mouse adipose‐derived stem cells (mASCs).

Materials and methods:  Varied concentrations of N‐[N‐(3,5‐difluorophenacetyl)‐l‐alanyl]‐S‐phenylglycine t‐butylester (DAPT) were added to mASCs 3 days before adipogenic induction with insulin‐containing differentiation medium. The process of adipogenesis and ability of lipid droplet accumulation were analysed using oil red‐O staining. The Notch signalling pathway (Notch‐1, ‐2, ‐3, ‐4, Hes‐1 and Hey‐1) and adipogenesis‐related factors (PPAR‐γ, DLK‐1/Pref‐1 and Acrp) were tested using real‐time PCR, Western blot analysis and immunofluorescence staining assays.

Results:  We demonstrated that Notch‐2‐Hes‐1 signalling pathway was inhibited dose‐dependently by DAPT in mASCs. In addition, transcription of PPAR‐γ was promoted by DAPT before adipogenic induction, while inhibitor of adipogenesis DLK‐1/Pref‐1 was further depressed. At early stages of differentiation (2–4 days), adipogenesis in mASCs was advanced and significantly enhanced in 5 and 10 μm DAPT pre‐treated cases. On day 4, in differentiated mASCs cases with DAPT pre‐treatment, we also found promotion of activation of de‐PPAR‐γ and depression of HES‐1, DLK‐1/Pref‐1 mRNA and protein expression.

Conclusions:  We conclude that blocking Notch signalling with DAPT enhances adipogenesis of differentiated mASCs at an early stage. It may be due to depression of DLK‐1/Pref‐1 and promotion of de‐PPAR‐γ activation, which work through inhibition of Notch‐2‐Hes‐1 pathway by DAPT.
Feasibility of using cryopreserved lymphoblastoid cells to diagnose some lysosomal storage diseases
Authors: De Mello A. S. , Provin F. , Michelin‐Tireli K. , Camelier M. V. , Coelho J. C.
Published: February 2010

Objectives:  The Epstein–Barr virus (EBV) is utilized as a tool in the study of cellular biology because of its capacity to transform B‐lymphocytes. For this reason, EBV is used in conservation of human B‐lymphocytes for long periods for subsequent evaluation of lysosomal hydrolase activity. Lymphoblastoid cell lines have several advantages for use over other cell types, such as prompt availability and possibility to develop, characterize and standardize cell banks, to test effects of promising pharmaceutical reagents. The study below presents biochemical data that demonstrate validity of lymphoblastoid cell lines for diagnosis of GM1‐gangliosidosis, Gaucher, Fabry and Pompe diseases and mucopolysaccharidosis type I.

Materials and methods:  Cultures were prepared from peripheral blood, collected from 25 normal subjects and 13 affected individuals. Enzyme activities and immunohistochemistry (IHC) were measured. Activities of enzymes β‐galactosidase, β‐glucosidase, α‐iduronidase, α‐galactosidase and α‐glucosidase were measured before and after cryopreservation for 180 days. Enzymatic activity was measured when transformation was confirmed by IHC.

Results:  We observed some significant alterations in enzymatic activity of non‐cultured cells when compared to others that had been cultured for 12 days and kept frozen for 180 days.

Conclusions:  However, these alterations did not invalidate use of the technology of transformation of lymphoblastoid cell lines with EBV, to diagnose the diseases mentioned above, in view of the fact that the cultured cells, before and after freezing, demonstrated similar enzymatic activities.
Establishment and biological characterization of fibroblast cell line from the Langshan chicken
Authors: Guan W. , He X. , Li L. , Liang H. , Zhao Q. , Pu Y. , Ma Y.‐H.
Published: February 2010

Objective:  We needed to establish an embryonic fibroblast cell line from the Langshan chicken (LSCEF61) to preserve their important genetic resources at the cellular level.

Material and methods:  The cell line was established from 9‐day‐old embryos by direct explant culture and cryopreservation techniques. Cell morphology, dynamic proliferation and any contamination present were tested, and the karyotype and levels of isoenzymes of lactic dehydrogenase and malic dehydrogenase were analysed. Four types of fluorescent protein exogenous genes for pEGFP‐C1, pEGFP‐N3, pEYFP‐N1 and pDsRed1‐N1 were transfected into the cells.

Results:  Showed that the cells were healthy and were of spindle shaped structure, without change in morphology. Cell growth curves were of typical S‐shape. Assays for microbial contamination were negative. The LSCEF61 line showed no cross‐contamination when assessed by isoenzyme analysis. Chromosome number (2n) = 78 on more than 90% of occasions. The four types of fluorescent protein extro‐genes appeared to be expressed effectively with high transfection efficiency between 15.6% and 38.6%.

Conclusion:  The cell line met each of the quality control standards required for the American Type Culture Collection. It had not only preserved the genetic resources of the important Langshan chicken at the cellular level, but also provided valuable material for genomic, post‐genomic and somatic cell cloning research and other applications.
Endothelin receptors blockade blunts hypoxia‐induced increase in PAP in humans
Authors: Pham I. , Wuerzner G. , Richalet J.‐P. , Peyrard S. , Azizi M.
Published: February 2010

Eur J Clin Invest 2010; 40 (3): 195–202

Background Activation of the endothelin‐1 (ET‐1) pathway may be involved in hypoxia‐induced pulmonary vasoconstriction, increase in pulmonary pressure and high altitude pulmonary oedema. Thus, we investigated the effect of the ETA/ETB receptor antagonist, bosentan, on pulmonary artery systolic pressure (PASP) in healthy subjects (n = 10).

Design We used a double‐blind, placebo‐controlled, randomized, cross‐over design to study the effects of a single oral dose of bosentan (250 mg) on PASP after 90‐min‐exposure to normobaric hypoxia (FiO2 = 0·12). We measured PASP and cardiac output by echocardiography, systolic arterial blood pressure, arterial O2saturation (SaO2), and blood gases at rest and during a sub‐maximal exercise.

Results PASP in normoxia at rest was 23·5 ± 2·7 and during exercise 39·8 ± 11·6 mmHg (P < 0·0001). During the placebo period, hypoxia induced a significant decrease in SaO2, PaO2and PCO2and increase in pH. PASP at rest increased significantly: 32·1 ± 3·5 mmHg (P < 0·001 vs. normoxia). Bosentan significantly blunted the hypoxia‐induced increase in PASP: bosentan: 27·0 ± 3·3 mmHg,P = 0·002 vs. placebo at rest, but not during exercise: bosentan 39·8 ± 11·6 vs. placebo 43·0 ± 8·5 mmHg, ns. Bosentan had no effect on the hypoxia‐induced changes in blood gases, or on cardiac output and systolic arterial blood pressure, which were not modified by hypoxia.

Conclusion A single oral dose of bosentan blunted an acute hypoxia‐induced increase in PASP in healthy subjects, without altering cardiac output or systemic blood pressure.
From kidney to cardiovascular diseases: NGAL as a biomarker beyond the confines of nephrology
Authors: Bolignano D. , Coppolino G. , Lacquaniti A. , Buemi M.
Published: February 2010

Eur J Clin Invest 2010; 40 (3): 273–276

Neutrophil gelatinase‐associated lipocalin (NGAL), a small 25 kDa stress‐protein released from injured tubular cells after various damaging stimuli, is already known by nephrologists as one of the most promising biomarkers of incoming Acute Kidney Injury. Moreover, recent studies seem to suggest a potential involvement of this factor also in the genesis and progression of chronic kidney diseases. This brief review explores the new interesting involvement of NGAL in the experimental and clinical field of cardiovascular diseases, such as the pathogenesis and clinical manifestations of atherosclerosis, acute myocardial infarction and heart failure. It does not seem difficult that, in the next future, NGAL may become a new missing link between the kidney and the cardiovascular system.
Pulse wave velocity and augmentation index, but not intima‐media thickness, are early indicators of vascular damage in hypercholesterolemic children
Authors: Riggio S. , Mandraffino G. , Sardo M. A. , Iudicello R. , Camarda N. , Imbalzano E. , Alibrandi A. , Saitta C. , Carerj S. , Arrigo T. , Saitta A.
Published: February 2010

Eur J Clin Invest 2010; 40 (3): 250–257

Background  Arterial stiffness is an important determinant of cardiovascular risk. It is associated with several cardiovascular risk factors, including hypertension, diabetes and cigarette smoking. However, there are conflicting data about the relationship between arterial stiffness and hypercholesterolemia. Furthermore, augmentation index (AIx), a measure of systemic arterial stiffness, has not been previously investigated in hypercholesterolemic (HCh) children. Aim of our study was to evaluate local and systemic arterial stiffness as well as carotid intima‐media thickness (IMT) in HCh children and also to investigate the relation between serum cholesterol levels and arterial stiffness.

Materials and methods  We determined lipid profile, body mass index, blood pressure, heart rate, carotid IMT and several arterial stiffness parameters, as β‐index, elastic modulus (Ep), arterial compliance (AC), pulse wave velocity (PWV) and AIx, in 44 untreated HCh children (mean age 10·7 ± 2·8 years; 18 with familial hypercholesterolemia, FH, and 26 with primary hypercholesterolemia, PHC) and 18 age‐ and sex‐matched controls. HCh children never received any medication, including antihypertensive and lipid lowering drugs.

Results  Respect to controls and to PHC, FH had significantly higher (P < 0·001) β‐index (5·22 ± 1·13 vs. 3·13 ± 0·74 and 3·60 ± 1·02), PWV (4·72 ± 0·72 m s−1 vs. 3·66 ± 0·55 m s−1 and 4·10 ± 0·67 m s−1), AIx (3·55 ± 3·97% vs. −4·43 ± 4·09% and 0·61 ± 2·39%) and Ep (64·4 ± 19·6 kPa vs. 36·2 ± 11·3 kPa and 42·9 ± 13·1), whereas AC (1·25 ± 0·48 mm2 kPa−1 vs. 1·9 ± 0·43 mm2 kPa−1 and 1·62 ± 0·43 mm2 kPa−1) was lower (P < 0·001). There was no significant difference in carotid IMT and blood pressure values between the groups. The multiple regression analysis showed a significant association of arterial stiffness values with plasma cholesterol levels (P < 0·0001).

Conclusion  Our findings show that local and systemic arterial stiffness are increased in asymptomatic, normotensive HCh children, suggesting that HCh plays a key role in arterial mechanical impairment since the paediatric age.
Sulfido‐peptide leukotrienes in coronary heart disease – relationship with disease instability and myocardial ischaemia
Authors: De Caterina R. , Giannessi D. , Lazzerini G. , Bernini W. , Sicari R. , Cupelli F. , Lenzi S. , Rugolotto M. M. , Madonna R. , Maclouf J.
Published: February 2010

Eur J Clin Invest 2010; 40 (3): 258–272

Background  Urinary excretion of leukotriene (LT) E4 is an index of LTC4 biosynthesis and platelet–neutrophil interactions, which may occur in coronary heart disease and contribute to myocardial ischaemia. Enhanced LTC4 biosynthesis may be a consequence of myocardial ischaemia or be linked to its pathogenetic substrate.

Methods and results  Overnight urine collections were obtained from 17 patients with chronic stable angina, three patients with Prinzmetal’s angina, 16 patients with non ST‐elevation acute coronary syndromes (NSTE‐ACS) and six patients with acute ST‐elevation myocardial infarction (STEMI). LTE4 excretion was measured by enzyme immunoassay after HPLC separation. Compared with healthy controls (51·1 ± 21·3 pg mg−1 creatinine, mean ± SD, n = 11) and with non‐coronary cardiac controls (36·6 ± 9·8 pg mg−1 creatinine, n = 9), LTE4 excretion was unchanged in stable angina (40·5 ± 25·8 pg mg−1 creatinine), but significantly (P < 0·01) increased in NSTE‐ACS (122·7 ± 137·2 pg mg−1 creatinine) and STEMI (213·4 ± 172·4 pg mg−1 creatinine). In these patients, LTE4 excretion rapidly dropped after day 1, consistent with effective coronary reperfusion. In patients with NSTE‐ACS, the increase in LTE4 excretion was entirely restricted to patients with recent (< 48 h) spontaneous anginal episodes. Myocardial ischaemia elicited by a positive exercise stress test was not accompanied by any detectable increase in LTE4 excretion, while a significant (P < 0·01) increase was detected after a single‐vessel percutaneous coronary interventions (PCI) procedure (n = 10), as compared with diagnostic angiography (n = 9).

Conclusions  In coronary heart disease, increased LTC4 biosynthesis is restricted to ACS and not linked to myocardial ischaemia per se, but likely to the occurrence of plaque disruption.