bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Peptidoglycan of Stationary-Phase
Mycobacterium tuberculosis
Predominantly Contains Cross-Links Generated by
l,d
-Transpeptidation
Authors: Lavollay Marie , Arthur Michel , Fourgeaud Martine , Dubost Lionel , Marie Arul , Veziris Nicolas , Blanot Didier , Gutmann Laurent , Mainardi Jean-Luc 
Published: April 2008

ABSTRACT

Our understanding of the mechanisms used by
Mycobacterium tuberculosis
to persist in a “dormant” state is essential to the development of therapies effective in sterilizing tissues. Gene expression profiling in model systems has revealed a complex adaptive response thought to endow
M. tuberculosis
with the capacity to survive several months of combinatorial antibiotic treatment. We show here that this adaptive response may involve remodeling of the peptidoglycan network by substitution of 4→3 cross-links generated by the
d
,
d
-transpeptidase activity of penicillin-binding proteins by 3→3 cross-links generated by a transpeptidase of
l,d
specificity. A candidate gene, previously shown to be upregulated upon nutrient starvation, was found to encode an
l,d
-transpeptidase active in the formation of 3→3 cross-links. The enzyme, Ldt
Mt1
, was inactivated by carbapenems, a class of β-lactam antibiotics that are poorly hydrolyzed by the
M. tuberculosis
β-lactamases. Ldt
Mt1
and carbapenems may therefore represent a target and a drug family relevant to the eradication of persistent
M. tuberculosis
.
Complete Genome Sequence of the Soil Actinomycete
Kocuria rhizophila
Authors: Takarada Hiromi , Sekine Mitsuo , Kosugi Hiroki , Matsuo Yasunori , Fujisawa Takatomo , Omata Seiha , Kishi Emi , Shimizu Ai , Tsukatani Naofumi , Tanikawa Satoshi , Fujita Nobuyuki , Harayama Shigeaki 
Published: April 2008

ABSTRACT

The soil actinomycete
Kocuria rhizophila
belongs to the suborder
Micrococcineae
, a divergent bacterial group for which only a limited amount of genomic information is currently available.
K. rhizophila
is also important in industrial applications; e.g., it is commonly used as a standard quality control strain for antimicrobial susceptibility testing. Sequencing and annotation of the genome of
K. rhizophila
DC2201 (NBRC 103217) revealed a single circular chromosome (2,697,540 bp; G+C content of 71.16%) containing 2,357 predicted protein-coding genes. Most of the predicted proteins (87.7%) were orthologous to actinobacterial proteins, and the genome showed fairly good conservation of synteny with taxonomically related actinobacterial genomes. On the other hand, the genome seems to encode much smaller numbers of proteins necessary for secondary metabolism (one each of nonribosomal peptide synthetase and type III polyketide synthase), transcriptional regulation, and lateral gene transfer, reflecting the small genome size. The presence of probable metabolic pathways for the transformation of phenolic compounds generated from the decomposition of plant materials, and the presence of a large number of genes associated with membrane transport, particularly amino acid transporters and drug efflux pumps, may contribute to the organism's utilization of root exudates, as well as the tolerance to various organic compounds.
Negative Regulation of Quorum-Sensing Systems inPseudomonas aeruginosaby ATP-Dependent Lon Protease
Authors: Takaya Akiko , Tabuchi Fumiaki , Tsuchiya Hiroko , Isogai Emiko , Yamamoto Tomoko 
Published: April 2008

ABSTRACTLon protease, a member of the ATP-dependent protease family, regulates numerous cellular systems by degrading specific substrates. Here, we demonstrate that Lon is involved in the regulation of quorum-sensing (QS) signaling systems inPseudomonas aeruginosa, an opportunistic human pathogen. The organism has two acyl-homoserine lactone (HSL)-mediated QS systems, LasR/LasI and RhlR/RhlI. Many reports have demonstrated that these two systems are regulated and interconnected by global regulators. We found thatlon-disrupted cells overproduce pyocyanin, the biosynthesis of which depends on the RhlR/RhlI system, and show increased levels of a transcriptional regulator, RhlR. The QS systems are organized hierarchically: the RhlR/RhlI system is subordinate to LasR/LasI. To elucidate the mechanism by which Lon negatively regulates RhlR/RhlI, we examined the effect oflondisruption on the LasR/LasI system. We found that Lon represses the expression of LasR/LasI by degrading LasI, an HSL synthase, leading to negative regulation of the RhlR/RhlI system. RhlR/RhlI was also shown to be regulated by Lon independently of LasR/LasI via regulation of RhlI, an HSL synthase. In view of these findings, it is suggested that Lon protease is a powerful negative regulator of both HSL-mediated QS systems inP. aeruginosa.
Role of Differential Expression of Streptococcal Arginine Deiminase in Inhibition of
fimA
Expression in
Porphyromonas gingivalis
Authors: Lin Xinghua , Lamont Richard J. , Wu Jie , Xie Hua 
Published: April 2008

ABSTRACT

Streptococcus cristatus
ArcA inhibits production of a major adhesin, FimA, in
Porphyromonas gingivalis
, a primary periodontal pathogen. In this study, we demonstrate the differential expression of
arcA
in two streptococcal species. The expression level of
arcA
in streptococci appears to be controlled by both
cis
and
trans
elements.
An essential role for SRC-activated STAT-3 in 14,15-EET–induced VEGF expression and angiogenesis
Authors: Cheranov Sergey Y. , Karpurapu Manjula , Wang Dong , Zhang Baolin , Venema Richard C. , Rao Gadiparthi N. 
Published: April 2008

Abstract
To understand the molecular mechanisms underlying 14,15-epoxyeicosatrienoic acid (14,15-EET)–induced angiogenesis, here we have studied the role of signal transducer and activator of transcription-3 (STAT-3). 14,15-EET stimulated the tyrosine phosphorylation of STAT-3 and its translocation from the cytoplasm to the nucleus in human dermal microvascular endothelial cells (HDMVECs). Adenovirus-mediated delivery of dominant negative STAT-3 substantially inhibited 14,15-EET–induced HDMVEC migration, and tube formation and Matrigel plug angiogenesis. 14,15-EET activated Src, as measured by its tyrosine phosphorylation and blockade of its activation by adenovirus-mediated expression of its dominant negative mutant, significantly attenuated 14,15-EET–induced STAT-3 phosphorylation in HDMVECs and the migration and tube formation of these cells and Matrigel plug angiogenesis. 14,15-EET induced the expression of vascular endothelial cell growth factor (VEGF) in a time- and Src-STAT-3–dependent manner in HDMVECs. Transfac analysis of VEGF promoter revealed the presence of STAT-binding elements and 14,15-EET induced STAT-3 binding to this promoter in vivo, and this interaction was inhibited by suppression of Src-STAT-3 signaling. Neutralizing anti-VEGF antibodies completely blocked 14,15-EET–induced HDMVEC migration and tube formation and Matrigel plug angiogenesis. These results reveal that Src-dependent STAT-3–mediated VEGF expression is a major mechanism of 14,15-EET–induced angiogenesis.
Activation-induced NKT cell hyporesponsiveness protects from α-galactosylceramide hepatitis and is independent of active transregulatory factors
Authors: Biburger Markus , Tiegs Gisa 
Published: April 2008

AbstractNK T (NKT) cells, unique lymphocytes expressing features of NK and T lymphocytes, can specifically be activated with the glycolipid antigen α-galactosylceramide (α-GalCer). In humans and mice, this activation provokes pronounced cytokine responses. In C57BL/6 mice, α-GalCer injection additionally induces NKT-mediated liver injury, representing a model for immune-mediated hepatitis in humans. However, a single α-GalCer pretreatment of mice prevented NKT-mediated liver injury, cytokine responses (systemically and locally in the liver), and up-regulation of hepatocellular Fas upon α-GalCer rechallenge. As α-GalCer is used as a NKT cell-activating agent in clinical trials, an investigation of tolerance induction appears crucial. We demonstrate that α-GalCer tolerance does not depend on Kupffer cells, IL-10, Caspase-3-mediated apoptosis, or CD4+CD25+ T regulatory cells (Tregs), which are crucial in other models of immunological tolerance. Amending relevant, earlier approaches of others, we cocultivated highly purified, nontolerized and tolerized liver NKT cells ex vivo and could convincingly exclude the relevance of transdominant NKT Tregs. These results strongly suggest α-GalCer-induced tolerance to be exclusively caused by NKT cell intrinsic hyporesponsiveness. Tolerized mice showed specific diminishment of the intrahepatic CD4+ NKT cell subpopulation, with the CD4− population largely unaffected, and revealed down-modulation of α-GalCer-specific TCR and the NKT costimulator glucocorticoid-induced TNFR-related protein on liver NKT cells, whereas inhibitory Ly49I was increased. In conclusion, α-GalCer tolerance could serve as a model for the frequently observed NKT cell hyporesponsiveness in tumor patients and might help to develop strategies for their reactivation. Conversely, approaches to render NKT cells hyporesponsive may constitute new therapeutic strategies for diseases, where aberrant NKT cell activation is causally involved.
Az intraductalis komponens jelentősége az emlőrák emlőmegtartó műtétei után fellépő lokális recidívák létrejöttébenr
Authors: Garami Zoltán , Szluha Kornélia , Fülöp Balázs , Lukács Géza , Damjanovich László 
Published: April 2008

Absztrakt
A korai stádiumú (stage I–II) emlőrákok miatt végzett emlőmegtartó műtétek utáni lokális recidíváknak (LR) számos hajlamosító tényezőjét említi a szakirodalom, de egyes faktorok jelentősége nem egyértelmű. Ilyen az intraductalis komponens (IC) jelenléte, melyet a szerzők egy része az LR prediktív faktorának tekint, mások nem, vagy csak egyéb tényezőkkel való együttes jelenlétekor találtak összefüggést az LR-rel. A szerzők vizsgálatukban arra a kérdésre keresték a választ, hogy beteganyagukban az IC különböző mértékű jelenléte mennyiben befolyásolja az LR mértékét különböző tumorméretek és szövettani anaplasiafokok mellett. 1996 és 2002 között 701 betegnél végeztek emlőmegtartó műtétet korai stádiumú emlőrák miatt. Az IC szempontjából a daganatokat 3 csoportba osztották: IC-negatív, ha intraductalis komponens nem volt kimutatható, MIC (IC < 25%), ha az intraductalis komponens az össztumormennyiség 25%-ánál kisebb volt, és EIC (IC > 25%), ha 25%-nál nagyobb mértékben volt jelen. 65 hónapos átlagos követési idő alatt 13,5%-ban észleltek LR-t. IC nélküli daganat esetében 8,7%-ban (recidívaráta: 0,017, 95% CI: 0,012–0,023) jelentkezett helyi kiújulás, ugyanezek az értékek MIC és EIC esetében 16,8%-ra (recidívaráta: 0,032, 95% CI: 0,021–0,047), illetve 25,6%-ra (recidívaráta: 0,046, 95% CI: 0,033–0,064) emelkedtek (p = 0,0001). T1 tumorméret esetében a fenti értékek 6,4%, 11% és 24,3%-nak, T2 esetében 11,5%, 22,9% és 27%-nak adódtak (p < 0,005). Ha az EIC G3 differenciáltsági fokkal társult, úgy T1 tumorméret esetén az IC nélküli 6,9%-ról 31%-ra (p = 0,008), T2 esetén 15,7%-ról 33,3%-ra nőtt az LR előfordulási gyakorisága (p = 0,02). Az eredményekből a szerzők azt állapítják meg, hogy az intraductalis komponens jelenléte önmagában is az LR felléptének nagyobb veszélyét jelenti, mely kockázat jelentősen növekszik, amennyiben az EIC G3 szövettani grade-del társul. A kiemelt kockázatú betegek egyénre szabott adjuváns kezelésének megtervezésekor ezt a tényt feltétlenül tekintetbe kell venni. Ezen betegcsoport utánkövetésére fokozott figyelmet kell fordítani.
Hosszú távú utánkövetés krónikus pancreatitis miatt végzett szervmegtartó pancreasfej-resectio után: 8 éves klinikai tapasztalatr
Authors: Farkas Gyula , Leindler László , Farkas Gyula 
Published: April 2008

Absztrakt
Krónikus pancreatitisben (CP) szenvedő betegek egyharmadában az inflammatoricus folyamat a pancreasfej gyulladásos tumorát idézi elő, mely a vezetékrendszerek obstructióját, fájdalmat és fogyást okoz. Egy biztonságos, szervmegtartó pancreasfej-resectiót (OPPHR) dolgoztunk ki. Közleményünkben az elmúlt 8 évben végzett 150 OPPHR műtéti és késői eredményeiről számolunk be. A sebészi beavatkozás magában foglalja a pancreasfejben kialakult gyulladásos tumor széles resectióját anélkül, hogy a pancreast a v. portae felett izolálnánk, illetve átvágnánk. A rekonstrukció, amely biztosítja a resecált pancreas secretióját az emésztőtraktus felé, a vékonybélből izolált Roux-kaccsal történik. A posztoperatív időszakban két reoperációra kényszerültünk, egyrészt anastomosisvérzés, másrészt vékonybél-adhaesiós ileus miatt, ugyanakkor halálos szövődmény nem jelentkezett. Az ápolási idő 7 és 12 nap között változott. Az áltagos utánkövetési idő 4,5 év volt (0,5–8 év). A késői mortalitás 4%-osnak bizonyult. A műtét után a betegek 89%-ában az életminőség javult, melyet EORTC Quality-of-Life kérdésekre adott válaszok bizonyítottak. A 8 éves klinikai megfigyeléseink egyértelműen alátámasztották, hogy az OPPHR műtét egy biztonságos és hatásos sebészi beavatkozás a CP komplikációinak megoldására, és javasolt műtétnek tekinthető a CP gyógyítására.
Videoasszisztált minithoracotomiából elvégzett lobectomia mint új műtéti eljárás klinikai gyakorlatunkbanr
Authors: Furák József , Bács Ervin , Grochulski Radek , Wolfárd Antal , Szőke Tamás , Troján Imre , Csernay Edina , Lázár György 
Published: April 2008

Absztrakt
Retrospektív tanulmányunkban az osztályunkon 2006-ban bevezetett, videoasszisztált minithoracotomiából (VAMT) végzett lobectomiákkal szerzett tapasztalatainkról számolunk be. 2006 első félévében 10 betegnél végeztünk minimálisan invazív technikával lobectomiát. A 8 nő- és 2 férfibeteg átlagéletkora 61,4 év (47–68) volt. A műtéti indikációt 3 betegnél jóindulatú daganat, 6 betegnél igazolt T1N0 laphámcarcinoma, 1 esetben a CT-kép alapján feltételezett, T1N0 stádiumú malignus folyamat képezte. Izolált intubálást követően történt a videothoracoscopos exploratio, majd a lapocka csúcsa alatt egy 6–8 cm-es minithoracotomiát végzünk. A bordák 2 cm-es felterpesztését követően végezzük el a tüdő áttapintását, a resectiót és malignus esetekben a mediastinalis blokkdissectiót. 5 alsólebeny-, 4 felsőlebeny-lobectomiát és 1 felső bilobectomiát végeztünk. Műtéti mortalitás vagy lényeges morbiditás nem volt. Az átlagos műtéti idő 130 perc (80–200) volt. A 3 benignoma hamartochondromának bizonyult. A szövettani vizsgálat 4 esetben T1N0, 2 esetben T2N2 laphámcarcinomát és 1 esetben T1N2 kissejtes tüdőrákot (műtét előtt laphámráknak diagnosztizálták) igazolt. A videoasszisztált minithoracotomiából végzett lobectomia biztonsággal alkalmazható műtéti eljárás. A tüdőállomány áttapintása és resectiója, valamint a mediastinalis blokkdissectio a nyitott műtétekhez hasonlóan kivitelezhető.
A műtét szerepe az időskori tüdőrák kezelésébenr
Authors: Benkő István , Horváth Örs Péter , Nagy Klára , Sárosi Veronika , Balikó Zoltán , Potó László , Molnár F. Tamás 
Published: April 2008

AbsztraktA világszerte vezető halálokként szereplő tüdőrák komplex kezelésében jelentős szerep jut a sebészi resectiónak, mely az átlagéletkor kitolódásával egyre idősebb embereken történik. Dolgozatunkban a 75 év feletti korosztály speciális problémáira szeretnénk rávilágítani az eredmények tükrében. Az 1995–2005 közötti 10 évben klinikánkon 908 beteget operáltunk meg nem kissejtes tüdőrák miatt, és 884 resectiós műtétre került sor. Ezen 75 év feletti betegcsoport adatainak retrospektív analízisét végeztük el. A betegeink közül 75 év feletti 54 volt, és közülük 80 év feletti pedig 12, átlagéletkoruk 77,5 év (75–85). Műtéti típusok: pneumonectomia (2), bilobectomia (2), lobectomia (41), segmentectomia (2), wedge resectio (5), lobectomia + mellkasfali resectio (2). Az átlagos ápolási idő 11,4 (8–36) nap. A 30 napon belüli mortalitás: 4 (7,4%). Posztoperatív szövődményt 28 betegnél (52%) észleltünk, melyek az alábbiak: váladékretentio 23 (43%), arrythmia 18 (33%), tágulási zavarok 8 (15%), hörgőcsonkkinyílás 2 (4%), reoperatio 3 (5%). Átlagos követés 32 hónap. Az 5 éves túlélés 33,7% (átlag 43 hónap). Többváltozós analízissel a kiterjesztett resectio, a férfinem és a 80 év feletti életkor adódott predilectiós tényezőnek a halálozásra. A hosszabb túlélést elősegítette a női nem, az IA stádium és a lobectomia. Mindezekből arra következtetünk, hogy a megfelelő betegkiválasztás (ASA 3 alatti, IA–IIA stádium) és a gondosan kivitelezett posztoperatív kezelés (monitorozás, fizioterápia) mellett megfelelő eredménnyel operálhattak egyre idősebb korú betegeink is.
The Openness of Knowledge Sharing within Organizations: A Comparative Study of the United States and the People's Republic of China
Authors: Chow Chee W. , Deng F. Johnny , Ho Joanna L. 
Published: April 2008

This study examines empirically the interaction effects of national culture and contextual factors (nature of the knowledge and the relationship between the knowledge sharer and recipient) on employees' tendency to share knowledge with co-workers. Quantitative and open-ended responses to two scenarios were collected from 142 managers (104 from the U.S. and 38 from the People's Republic of China). These two nations were selected due to their divergence on salient aspects of national culture, as well as their global political and economic importance. The focus on interaction effects was aimed at providing a more powerful test of culture's effects than simple comparisons of means typical of prior related research.
Consistent with culture-based expectation, the quantitative results indicated that Chinese vs. U.S. nationals' openness of knowledge sharing was related to their different degrees of collectivism—the relative emphasis on self vs. collective interests—as well as whether knowledge sharing involved a conflict between self and collective interests. Also consistent with prediction, Chinese relative to U.S. nationals shared knowledge significantly less with a potential recipient who was not a member of their “ingroup.” Content analysis of the open-ended responses further showed that the quantitative results are the aggregated outcomes of trade-offs across cultural attributes and their interactions with contextual factors.
Promotion and Performance Evaluation of Managerial Accountants (Retracted)
Authors: Wier Benson , Stone Dan N. , Hunton James E. 
Published: April 2008

Using survey, interview, and archival data, we investigate two questions related to managerial accountants' (MA) performance evaluations (PE) and promotion processes: (1) Are there “fast tracks” (i.e., positive serial dependencies) in promotions? (2) Are promotions primarily determined by within-rank comparisons (i.e., “relative” comparisons) or comparisons to standards (i.e., “absolute” evaluations)? The survey data (n = 101) suggest that lower- and higher-ranking MA have differing perceptions of PE and promotion processes. For example, lower-ranking MA generally believe in the existence of fast-track promotions while higher-ranking MA do not.
Twenty years of archival PE and promotion data (1976–1995) from 5,899 managerial accountants employed at 2,525 companies in three industries (publishing, paper, and chemical) do not support the existence of fast-track promotions; instead, the archival data suggest a negative correlation between time to promotion to senior and time to promotion to manager. In addition, these data suggest that comparisons to standards are the largest influence on promotions to manager, while within-rank comparisons are the largest influence on promotions to senior. We conclude by discussing the importance and limitations of our results.
Performance Measurement and Reward Systems, Trust, and Strategic Change
Authors: Chenhall Robert H. , Langfield-Smith Kim 
Published: April 2008

This study examines the extent to which a manufacturing company used performance measurement and a gain-sharing reward system to achieve strategic change over a 15-year period. The case examines the initial impact of the gain-sharing scheme in overcoming inherent hostility within the workforce, its continued success in gaining the cooperation of employees to work toward the successful implementation of strategic initiatives and, finally, its limitations in sustaining ongoing strategic change after a ten-year period of apparent success. The firm eventually adopted team-based structures to complement gain sharing and sustain commitment to strategic change.We explain the apparent success of the gain-sharing scheme over the first ten-year period in terms of the role of organizational trust. Gain sharing is a mechanistic form of control system, and hence may be compatible with organizational trust. After this initial success, managers believed that the level of employee cooperation to sustain strategic change was insufficient to maintain high performance in an increasingly competitive environment. The firm then introduced team-based structures to enhance employee enthusiasm to work toward sustaining strategic change. The adoption of teams promotes personal trust and the sharing of values and goals. The team-based initiatives did not result in significant performance improvements. We attribute this result, in part, to the continued role of gain sharing, a mechanistic control, which inhibited the development of personal trust.
Effects of Progesterone on Benzene Toxicity in Rats
Authors: Verma Yeshvandra , Rana Suresh 
Published: April 2008

Effects of Progesterone on Benzene Toxicity in RatsBenzene is a frequently used industrial solvent. Its toxic manifestations could be modified by sex hormones, but mechanisms of their action are poorly understood. We have examined the influence of progesterone on lipid peroxidation (malondialdehyde), reduced glutathione (GSH), and cytochrome P450 2E1 (CYP2E1) in the liver and kidneys of female rats. Progesterone applied to benzene-treated rats inhibited the formation of reactive oxygen species (ROS), but in ovariectomised benzene-treated rats it significantly increased GSH in the liver. No improvement in CYP2E1 activity was observed in progesterone treated rats. Our results evidence that progesterone changes benzene toxicity (generation of ROS, oxidative stress). However, the probable antioxidative effect of progesterone needs to be confirmed by further studies.
Non-Hip Peripheral Osteoporotic Fractures: Epidemiology and Significance
Authors: Koršić Mirko , Grazio Simeon 
Published: April 2008

Non-Hip Peripheral Osteoporotic Fractures: Epidemiology and SignificanceFractures are the most serious consequence of osteoporosis. Non-vertebral and non-hip fractures are seldom recognised as important, even though they account for the majority of all fractures. The most prevalent localisations are distal radius, proximal humerus, ribs, clavicle, and the pelvis. According to the results from large phase III clinical trials for placebo groups, their incidence ranges from 4.9 % to 12.0 %. Hospital morbidity data in Croatia in 2006 show that peripheral non-hip fractures ranked among the leading fifteen injuries, accounting for 23.7 % of all injuries in patients aged 60 years and above. Risk factors for non-hip and non-vertebral fractures are similar to other osteoporotic fractures, and the main are low bone mineral density and earlier fractures. Quality of life is considerably affected by these fractures, and medical costs are very high, soaring as high as 36.9% of all national medical costs in the USA. Non-vertebral non-hip fractures need more attention, which was also recognised by the European regulatory bodies that approve use of anti-osteoporotic drugs.
Synthesis and pharmacological activities of some condensed 4-chloro-2,2-dialkyl chromene-3-carbaldehyde derivatives
Authors: Hegab Mohamed , Yousef Nabil , Nour Hany , Ellithey Mohey , Arbid Mahmoud 
Published: April 2008

Synthesis and pharmacological activities of some condensed 4-chloro-2,2-dialkyl chromene-3-carbaldehyde derivativesSome new hydrazono5a,b, thiosemicarbazono6a-c, and oximo chromenes7a-cwere preparedviathe reaction of the corresponding β-chlorocarbaldehyde3with hydrazine, aromatic hydrazine, thiosemicarbazide and hydroxylamine hydrochloride, respectively. In addition, ether derivatives8a-hwere prepared from the corresponding aldoximes7a-c. The new products were tested for anti-inflammatory and ulcerogenic score activities compared to indomethacin.