bluuebunny/crossref_metadata_2025 huggingface dataset:
Bax regulates primary necrosis through mitochondrial dynamics
Authors: Whelan Russell S. , Konstantinidis Klitos , Wei An-Chi , Chen Yun , Reyna Denis E. , Jha Saurabh , Yang Ying , Calvert John W. , Lindsten Tullia , Thompson Craig B. , Crow Michael T. , Gavathiotis Evripidis , Dorn Gerald W. , O'Rourke Brian , Kitsis Richard N.
Published: April 2012

The defining event in apoptosis is mitochondrial outer membrane permeabilization (MOMP), allowing apoptogen release. In contrast, the triggering event in primary necrosis is early opening of the inner membrane mitochondrial permeability transition pore (mPTP), precipitating mitochondrial dysfunction and cessation of ATP synthesis. Bcl-2 proteins Bax and Bak are the principal activators of MOMP and apoptosis. Unexpectedly, we find that deletion of Bax and Bak dramatically reduces necrotic injury during myocardial infarction in vivo. Triple knockout mice lacking Bax/Bak and cyclophilin D, a key regulator of necrosis, fail to show further reduction in infarct size over those deficient in Bax/Bak. Absence of Bax/Bak renders cells resistant to mPTP opening and necrosis, effects confirmed in isolated mitochondria. Reconstitution of these cells or mitochondria with wild-type Bax, or an oligomerization-deficient mutant that cannot support MOMP and apoptosis, restores mPTP opening and necrosis, implicating distinct mechanisms for Bax-regulated necrosis and apoptosis. Both forms of Bax restore mitochondrial fusion in Bax/Bak-null cells, which otherwise exhibit fragmented mitochondria. Cells lacking mitofusin 2 (Mfn2), which exhibit similar fusion defects, are protected to the same extent as Bax/Bak-null cells. Conversely, restoration of fused mitochondria through inhibition of fission potentiates mPTP opening in the absence of Bax/Bak or Mfn2, indicating that the fused state itself is critical. These data demonstrate that Bax-driven fusion lowers the threshold for mPTP opening and necrosis. Thus, Bax and Bak play wider roles in cell death than previously appreciated and may be optimal therapeutic targets for diseases that involve both forms of cell death.
Cotranslational
cis
-phosphorylation of the COOH-terminal tail is a key priming step in the maturation of cAMP-dependent protein kinase
Authors: Keshwani Malik M. , Klammt Christian , von Daake Sventja , Ma Yuliang , Kornev Alexandr P. , Choe Senyon , Insel Paul A. , Taylor Susan S.
Published: April 2012

cAMP-dependent protein kinase A (PKA), ubiquitously expressed in mammalian cells, regulates a plethora of cellular processes through its ability to phosphorylate many protein substrates, including transcription factors, ion channels, apoptotic proteins, transporters, and metabolic enzymes. The PKA catalytic subunit has two phosphorylation sites, a well-studied site in the activation loop (Thr
197
) and another site in the C-terminal tail (Ser
338
) for which the role of phosphorylation is unknown. We show here, using in vitro studies and experiments with S49 lymphoma cells, that
cis
-autophosphorylation of Ser
338
occurs cotranslationally, when PKA is associated with ribosomes and precedes posttranslational phosphorylation of the activation loop Thr
197
. Ser
338
phoshorylation is not required for PKA activity or formation of the holoenzyme complex; however, it is critical for processing and maturation of PKA, and it is a prerequisite for phosphorylation of Thr
197
. After Thr
197
and Ser
338
are phosphorylated, both sites are remarkably resistant to phosphatases. Phosphatase resistance of the activation loop, a unique feature of both PKA and PKG, reflects the distinct way that signal transduction dynamics are controlled by cyclic nucleotide-dependent PKs.
Transition states of native and drug-resistant HIV-1 protease are the same
Authors: Kipp D. Randal , Hirschi Jennifer S. , Wakata Aya , Goldstein Harris , Schramm Vern L.
Published: April 2012

HIV-1 protease is an important target for the treatment of HIV/AIDS. However, drug resistance is a persistent problem and new inhibitors are needed. An approach toward understanding enzyme chemistry, the basis of drug resistance, and the design of powerful inhibitors is to establish the structure of enzymatic transition states. Enzymatic transition structures can be established by matching experimental kinetic isotope effects (KIEs) with theoretical predictions. However, the HIV-1 protease transition state has not been previously resolved using these methods. We have measured primary
14
C and
15
N KIEs and secondary
3
H and
18
O KIEs for native and multidrug-resistant HIV-1 protease (I84V). We observed
14
C KIEs (
14
V
/
K
) of 1.029 ± 0.003 and 1.025 ± 0.005,
15
N KIEs (
15
V
/
K
) of 0.987 ± 0.004 and 0.989 ± 0.003,
18
O KIEs (
18
V
/
K
) of 0.999 ± 0.003 and 0.993 ± 0.003, and
3
H KIEs (
3
V
/
K
) KIEs of 0.968 ± 0.001 and 0.976 ± 0.001 for the native and I84V enzyme, respectively. The chemical reaction involves nucleophilic water attack at the carbonyl carbon, proton transfer to the amide nitrogen leaving group, and C-N bond cleavage. A transition structure consistent with the KIE values involves proton transfer from the active site Asp-125 (1.32 Å) with partial hydrogen bond formation to the accepting nitrogen (1.20 Å) and partial bond loss from the carbonyl carbon to the amide leaving group (1.52 Å). The KIEs measured for the native and I84V enzyme indicate nearly identical transition states, implying that a true transition-state analogue should be effective against both enzymes.
Crystal structure of
Staphylococcus aureus
transglycosylase in complex with a lipid II analog and elucidation of peptidoglycan synthesis mechanism
Authors: Huang Chia-Ying , Shih Hao-Wei , Lin Li-Ying , Tien Yi-Wen , Cheng Ting-Jen Rachel , Cheng Wei-Chieh , Wong Chi-Huey , Ma Che
Published: April 2012

Bacterial transpeptidase and transglycosylase on the surface are essential for cell wall synthesis, and many antibiotics have been developed to target the transpeptidase; however, the problem of antibiotic resistance has arisen and caused a major threat in bacterial infection. The transglycosylase has been considered to be another excellent target, but no antibiotics have been developed to target this enzyme. Here, we determined the crystal structure of the
Staphylococcus aureus
membrane-bound transglycosylase, monofunctional glycosyltransferase, in complex with a lipid II analog to 2.3 Å resolution. Our results showed that the lipid II-contacting residues are not only conserved in WT and drug-resistant bacteria but also significant in enzymatic activity. Mechanistically, we proposed that K140 and R148 in the donor site, instead of the previously proposed E156, are used to stabilize the pyrophosphate-leaving group of lipid II, and E100 in the acceptor site acts as general base for the 4-OH of GlcNAc to facilitate the transglycosylation reaction. This mechanism, further supported by mutagenesis study and the structure of monofunctional glycosyltransferase in complex with moenomycin in the donor site, provides a direction for antibacterial drugs design.
Concordance between Urinary Cotinine Levels and Self-Reported Tobacco Use among Drug-Dependent Persons: A Pilot Study
Authors: Jain Raka , Balhara Yatan Pal Singh , Jhanjee Sonali , Sethi Hem
Published: April 2012

Self-reported drug use is a principle measure in the evaluation of treatment outcome. As there have been concerns about the accuracy of self-reporting, it is necessary to establish its validity by an objective method. The aim of the study was to examine the concordance between urinary cotinine concentrations and self-reported tobacco use among drug dependents seeking treatment at National Drug Dependence Treatment Centre, AIIMS, New Delhi, India. Eighty consecutive male drug addicts attending the OPD at National Drug Dependence Treatment Centre were interviewed by the clinician. Their tobacco as well as drug use history was recorded, and thereafter their urine sample was analyzed for drug testing. Mean age of the subjects was found to be 33 years (SD: 10). Urinalysis showed high concentration of cotinine (mean ± SD: 586.40 ± 222.15 ng/ml) in 95% of the subjects. High concordance was observed between self-report of tobacco use and urinary cotinine. The quantity of tobacco consumption and FTND scores were also correlated with the urinary cotinine levels. Urinalysis also showed misuse of opioids, benzodiazepines and antihistaminics. The treatment for tobacco use has been given low priority in the de-addiction centers. Tobacco is highly prevalent among the drug abusers. The effectiveness of the treatment program may be increased by using the combination of urine analysis along with self-report.
The Relationship between Substance Abuse Treatment Completion, Sociodemographics, Substance Use Characteristics, and Criminal History
Authors: Turan Reyhan , Yargic Ilhan
Published: April 2012

The purpose of this study is to determine if a significant relationship exists between the sociodemographics, substance use characteristics, criminal history, and completion of substance abuse treatment. In this study, 115 individuals being monitored for substance abuse treatment on probation at the Probation and Help Center under the Republic of Turkey's Ministry of Justice's Chief Public Prosecutor's Office of Istanbul were included successively between the dates of April 2008 and April 2009. During a 24-week follow-up, individuals whose urine analyses were clean 6 times consecutively were considered to have completed the treatment successfully. To determine the effect of sociodemographic factors and substance use characteristics on treatment completion, a semistructured sociodemographic data survey was used. Also, the participants’ criminal records were examined. A total of 115 people participated in the study. One hundred ten (95.7%) of them were male. Sixty-eight (59.1%) of the participants had completed treatment. Age group, education level, age of onset for substance use, number of substances used, employment status, and criminal records showed a significant difference between treatment completers and noncompleters. When a logistic regression analysis was done, only number of substances used and criminal record (other than drug possession) were significantly different for the 2 groups. The current treatment program for polysubstance users and individuals with a criminal record is insufficient. It is necessary that treatment systems be developed so they can be beneficial for these types of patients.
Empirical Awakening: The New Science on Mutual Help and Implications for Cost Containment under Health Care Reform
Authors: Kelly John F. , Yeterian Julie D.
Published: April 2012

Over the past 75 years, Alcoholics Anonymous (AA) has grown from 2 members to over 2 million members. AA and similar organizations (e.g., Narcotics Anonymous [NA]) are among the most commonly sought sources of help for substance-related problems in the United States. It is only relatively recently, however, that the scientific community has conducted rigorous studies on the clinical utility and health care cost-offset potential of mutual-help groups and developed and tested professional treatments to facilitate their use. As a result of this research, AA as an organization has experienced an “empirical awakening,” evolving from its peripheral status as a “nuisance variable” and perceived obstacle to progress to playing a more central role in a scientifically informed recovery oriented system of care. Also, professionally delivered interventions designed to facilitate the use of AA and NA (“Twelve-Step Facilitation” [TSF]) are now “empirically supported treatments” as defined by US federal agencies and the American Psychological Association. Under the auspices of health care reform, a rational societal response to the prodigious health and social burden posed by alcohol and other drug misuse should encompass the implementation of empirically based strategies (e.g., TSF) in order to maximize the use of ubiquitous mutual-help recovery resources.
Spice: A New “Legal” Herbal Mixture Abused by Young Active Duty Military Personnel
Authors: Bebarta Vikhyat S. , Ramirez Sasha , Varney Shawn M.
Published: April 2012

Spice is an herbal mixture smoked for euphoria and mixed with synthetic cannabinoids that are undetected on urine drug screens. Spice use has increased in the military because it is considered legal and is not detected on urine drug screen. The authors describe 3 cases of Spice use in military members. Case 1: 19-year-old male presented with paranoia, agitation, and visual hallucinations after smoking the “Space” brand of Spice. Urine thin-layer chromatography (TLC) and gas chromatography–mass spectrometry (GC-MS) were negative. Case 2: 19-year-old female presented with sedation, amnesia, and agitation. She smoked the “Space” brand. She was alert within 3 hours of arrival. Urine GC-MS detected levorphanol. Case 3: 23-year-old male presented with delusions and paranoia. He complained of “monsters on his back.” His symptoms improved in the emergency department (ED). His urine TLC and GC-MS were negative. All cases were admitted and evaluated by a toxicologist; all 3 had their history corroborated by family or friends, or with drug paraphernalia. Spice is a new herbal mixture that is increasingly used in the military. Expected effects are similar to cannabis, but may include more paranoia and hallucinations, and may differ for each brand.
Social Modeling Influences and Alcohol Consumption during the First Semester of College: A Natural History Study
Authors: Talbott Laura L. , Moore Charity G. , Usdan Stuart L.
Published: April 2012

The authors examine both the alcohol consumption pattern of freshmen students during their first semester and the degree to which social modeling of peer behavior impacts consumption. A total of 534 students, residing on campus, were prospectively examined at four 30-day intervals. Data were evaluated on the basis of age, gender, and the effects of time using generalized estimating equations (GEEs). Results reflected nonsignificant increases in the amount of alcohol consumed; however, affiliations with alcohol-consuming peer groups was significantly associated with increased alcohol consumption. The mean number of drinks consumed in the past 30 days remained the same for whites (χ2 = 3.35, 3 df, P = .3411) but increased slightly for blacks (χ2 = 7.99, 3 df, P = .0462). Prevention programs should include screening for growth in alcohol consumption among first-year university students, and such screenings should include the extent and nature of affiliation with peers who consume alcohol.
MCAK activity at microtubule tips regulates spindle microtubule length to promote robust kinetochore attachment
Authors: Domnitz Sarah B. , Wagenbach Michael , Decarreau Justin , Wordeman Linda
Published: April 2012

Mitotic centromere-associated kinesin (MCAK) is a microtubule-depolymerizing kinesin-13 member that can track with polymerizing microtubule tips (hereafter referred to as tip tracking) during both interphase and mitosis. MCAK tracks with microtubule tips by binding to end-binding proteins (EBs) through the microtubule tip localization signal SKIP, which lies N terminal to MCAK’s neck and motor domain. The functional significance of MCAK’s tip-tracking behavior during mitosis has never been explained. In this paper, we identify and define a mitotic function specific to the microtubule tip–associated population of MCAK: negative regulation of microtubule length within the assembling bipolar spindle. This function depends on MCAK’s ability to bind EBs and track with polymerizing nonkinetochore microtubule tips. Although this activity antagonizes centrosome separation during bipolarization, it ultimately benefits the dividing cell by promoting robust kinetochore attachments to the spindle microtubules.
Dendritic position is a major determinant of presynaptic strength
Authors: de Jong Arthur P.H. , Schmitz Sabine K. , Toonen Ruud F.G. , Verhage Matthijs
Published: April 2012

Different regulatory principles influence synaptic coupling between neurons, including positional principles. In dendrites of pyramidal neurons, postsynaptic sensitivity depends on synapse location, with distal synapses having the highest gain. In this paper, we investigate whether similar rules exist for presynaptic terminals in mixed networks of pyramidal and dentate gyrus (DG) neurons. Unexpectedly, distal synapses had the lowest staining intensities for vesicular proteins vGlut, vGAT, Synaptotagmin, and VAMP and for many nonvesicular proteins, including Bassoon, Munc18, and Syntaxin. Concomitantly, distal synapses displayed less vesicle release upon stimulation. This dependence of presynaptic strength on dendritic position persisted after chronically blocking action potential firing and postsynaptic receptors but was markedly reduced on DG dendrites compared with pyramidal dendrites. These data reveal a novel rule, independent of neuronal activity, which regulates presynaptic strength according to dendritic position, with the strongest terminals closest to the soma. This gradient is opposite to postsynaptic gradients observed in pyramidal dendrites, and different cell types apply this rule to a different extent.
Autotaxin expression from synovial fibroblasts is essential for the pathogenesis of modeled arthritis
Authors: Nikitopoulou Ioanna , Oikonomou Nikos , Karouzakis Emmanuel , Sevastou Ioanna , Nikolaidou-Katsaridou Nefeli , Zhao Zhenwen , Mersinias Vassilis , Armaka Maria , Xu Yan , Masu Masayuki , Mills Gordon B. , Gay Steffen , Kollias George , Aidinis Vassilis
Published: April 2012

Rheumatoid arthritis is a destructive arthropathy characterized by chronic synovial inflammation that imposes a substantial socioeconomic burden. Under the influence of the proinflammatory milieu, synovial fibroblasts (SFs), the main effector cells in disease pathogenesis, become activated and hyperplastic, releasing proinflammatory factors and tissue-remodeling enzymes. This study shows that activated arthritic SFs from human patients and animal models express significant quantities of autotaxin (ATX; ENPP2), a lysophospholipase D that catalyzes the conversion of lysophosphatidylcholine to lysophosphatidic acid (LPA). ATX expression from SFs was induced by TNF, and LPA induced SF activation and effector functions in synergy with TNF. Conditional genetic ablation of ATX in mesenchymal cells, including SFs, resulted in disease attenuation in animal models of arthritis, establishing the ATX/LPA axis as a novel player in chronic inflammation and the pathogenesis of arthritis and a promising therapeutic target.
Occurrence of Impatiens necrotic spot virus and Tomato spotted wilt virus on Potatoes in Iran
Authors: Pourrahim R. , Golnaraghi A. R. , Farzadfar Sh.
Published: April 2012

There have been an increasing number of records of the natural infection of various crops and ornamentals in Iran with Impatiens necrotic spot virus (INSV), Tomato spotted wilt virus (TSWV), and Tomato yellow fruit ring virus (TYFRV), a recently proposed species in the genus Topovirus (3). TYFRV, originally believed to be TSWV and named as such, has been previously reported to occur in Iranian potato fields (2). During the growing seasons of 2004 to 2006, surveys were conducted in potato fields in different potato-producing (Solanum tuberosum) provinces of Iran (Ardabil, Azarbayejan-e-sharqi, Chaharmahal-va-bakhtiyari, Esfahan, Hamedan, Kerman, Khorasan, Khuzestan, Lorestan, Tehran, Qazvin, and Zanjan) to detect the presence of Tospovirus spp. infecting this crop, including Groundnut ringspot virus (GRSV), INSV, Iris yellow spot virus (IYSV), Tomato chlorotic spot virus (TCSV), TSWV, TYFRV, and Watermelon silver mottle virus (WSMoV). Overall, 186 fields were surveyed, and 2,823 potato leaf samples from plants showing tospovirus-like symptoms of chlorotic or necrotic spots, chlorosis, and necrosis were collected before or through the flowering stage, approximately 50 to 90 days after planting. Each leaf sample was tested by double-antibody sandwich (DAS)-ELISA using specific antisera (Bioreba, Reinach, Switzerland; Loewe, Sauerlach, Germany; DSMZ, Braunschweig, Germany) for the presence of the aforementioned tospoviruses. TYFRV, TSWV, and INSV were found in 24.0, 4.1, and 0.4% of the samples collected from 133, 51, and 7 fields surveyed, respectively. None of the samples had a positive reaction in ELISA to GRSV, IYSV, TCSV, and WSMoV. To confirm this testing, a number of the leaf samples that were found to be positive for INSV, TSWV, and TYFRV in ELISA tests were mechanically inoculated on Petunia × hybrid and Nicotiana benthamiana; the inoculated plants showed typical necrotic local lesions of tospoviruses and chlorotic or necrotic spots followed by systemic infection, respectively; their infection was subsequently confirmed by ELISA. The samples also were tested by reverse transcription-PCR technique using previously described specific primers (1,4). The PCR reaction resulted in the specific amplification of a 0.59-, 0.71-, and 0.67-kb (or 1.2-kb) fragment of INSV, TSWV, and TYFRV RNAs, respectively. This study showed that tospoviruses, especially TYFRV, are widespread in Iranian potato fields. It is hoped that the results may help us to improve a seed potato certification program in the future. To our knowledge, this is the first report of INSV and TSWV from potatoes in Iran.

References: (1) A. R. Golnaraghi et al. Plant Dis. 92:1280, 2008. (2) R. Pourrahim et al. Plant Dis. 84:442, 2001. (3) S. Winter et al. Plant Pathol. 55:287, 2006. (4) H. Uga and S. Tsuda. Phytopathology 95:166, 2005.
First Report of Cylindrocarpon macrodidymum Associated with Black Foot Diseases of Grapevine in Turkey
Authors: Özben S. , Demirci F. , Değirmenci K. , Uzunok S.
Published: April 2012

Grape (Vitis vinifera) is widely planted and is an economically important crop in Turkey for domestic consumption and export. Black foot disease, caused by Cylindrocarpon macrodidymum Halleen, Schroers & Crous, is a recently identified but worsening problem in vineyards worldwide (3,4). Symptomatic grapevines show reduced vigor, shortened internodes, small leaves with interveinal chlorosis, and necrosis frequently leading to the death of the plants (1). Roots of symptomatic grapevines exhibit black, sunken, necrotic lesions with a reduction in root biomass. Pith of affected vines is discolored (4). During the summers of 2009 and 2010, a survey was carried out in 63 vineyards (4 to 15 years old) in six locations of Ankara Province. We collected 44 samples from roots and crowns of grapevines exhibiting black foot symptoms. In cross section, extensive necrosis at the base of the trunk and brown-black spots in xylem vessels were observed, resembling those previously reported for black foot disease (2,4). Isolations were made from roots, vascular elements, and pith tissue. In this study, 26 isolates were identified as C. macrodidymum on the basis of morphological characteristics. Isolates identified as C. macrodidymum had a dark orange-brown colony color and abundant aerial mycelia when grown on potato dextrose agar. Isolates produced ellipsoid or ovoid microconidia. The macroconidia were one to three septate, straight, and cylindrical. One-septate macroconidia were 24 to 32 × 5 to 7 μm; three-septate macroconidia were 26 to 40 × 5 to 6 μm. Chlamydospores developed in short, intercalary chains. Conidiophores were simple or complex and sporodochial. Isolate identities were confirmed by sequence analysis of the ribosomal DNA internal transcribed spacer (GenBank Accession No. HM245331) with primers ITS1 and ITS4 (4). Isolates had 99% genetic identity with other isolates of C. macrodidymum present in GenBank. In pathogenicity tests, one representative isolate was used to inoculate five grapevine plants. Tests were completed by drench inoculation onto 3-month-old rooted cuttings of cv. Sultana with 25 ml of a conidia suspension (106 conidia ml–1). Controls were inoculated with an equal volume of sterile distilled water. Plants were incubated for 4 months in a controlled environment facility at 25°C. After 3 to 4 months, inoculations resulted in reduction of root mass, and C. macrodidymum was reisolated from regions of brown streaking in wood and discolored vascular tissue in all inoculated plants, fulfilling Koch's postulates. Control plants were asymptomatic and C. macrodidymum was not recovered from control plants. To our knowledge, this is the first report of the presence of C. macrodidymum causing black foot disease on grapevine in Turkey.

References: (1) S. Alaniz et al. Plant Dis. 93:821, 2009. (2) F. Hallen et al. Stud. Mycol. 50:431, 2004. (3) F. Halleen et al. Phytopathol. Mediterr. 45:S55, 2006. (4) E. Petit and W. D. Gubler. Plant Dis. 89:1051, 2005.
Effects of Beet necrotic yellow vein virus in Spinach Cultivars
Authors: Mou B. , Richardson K. , Benzen S. , Liu H.-Y.
Published: April 2012

Beet necrotic yellow vein virus (BNYVV) causes one of the most economically destructive diseases of sugar beet (Beta vulgaris), rhizomania, which may reduce sugar yield by 80%. This field investigation was conducted to evaluate the interactions between spinach genotypes and different BNYVV strains, and to determine whether BNYVV is transmitted through spinach seeds. Eight commercial spinach cultivars were planted in two BNYVV-infested fields and two control fields in Salinas, CA in 2009. Spinach plants in the BNYVV-infested fields showed disease symptoms of yellow-green or light-green vein clearing, mottling, or yellow-green chlorotic lesions on younger leaves as early as 28 days after planting (four- to six-true leaf stage). Leaves may also become stiff, more crinkled, and necrotic. There was an increase of lateral roots and leaf number but a decrease in leaf weight compared to healthy plants. Infected plants often became stunted, deformed, wilted, and dead. Symptomatic leaves and roots from plants with or without leaf symptoms in BNYVV-infested fields all tested positive for BNYVV by enzyme-linked immunosorbent assay. A more aggressive (resistance-breaking) strain of BNYVV led to higher disease incidence in spinach than in the wild type. BNYVV was not transmitted through spinach seeds. There were significant differences in disease development among cultivars, with disease incidence ranging from 8 to 44%, suggesting that genetic improvement of BNYVV resistance through spinach breeding should be feasible.
NaJAZh Regulates a Subset of Defense Responses against Herbivores and Spontaneous Leaf Necrosis inNicotiana attenuataPlants
Authors: Oh Youngjoo , Baldwin Ian T. , Gális Ivan
Published: April 2012

The JASMONATE ZIM DOMAIN (JAZ) proteins function as negative regulators of jasmonic acid signaling in plants. We cloned 12 JAZ genes from native tobacco (Nicotiana attenuata), including nine novel JAZs in tobacco, and examined their expression in plants that had leaves elicited by wounding or simulated herbivory. Most JAZ genes showed strong expression in the elicited leaves, but NaJAZg was mainly expressed in roots. Another novel herbivory-elicited gene, NaJAZh, was analyzed in detail. RNA interference suppression of this gene in inverted-repeat (ir)JAZh plants deregulated a specific branch of jasmonic acid-dependent direct and indirect defenses: irJAZh plants showed greater trypsin protease inhibitor activity, 17-hydroxygeranyllinalool diterpene glycosides accumulation, and emission of volatile organic compounds from leaves. Silencing of NaJAZh also revealed a novel cross talk in JAZ-regulated secondary metabolism, as irJAZh plants had significantly reduced nicotine levels. In addition, irJAZh spontaneously developed leaf necrosis during the transition to flowering. Because the lesions closely correlated with the elevated expression of programmed cell death genes and the accumulations of salicylic acid and hydrogen peroxide in the leaves, we propose a novel role of the NaJAZh protein as a repressor of necrosis and/or programmed cell death during plant development.
Structures and immunolocalization of Na+, K+‐ATPase, Na+/H+ exchanger 3 and vacuolar‐type H+‐ATPase in the gills of blennies (Teleostei: Blenniidae) inhabiting rocky intertidal areas
Authors: Uchiyama M. , Komiyama M. , Yoshizawa H. , Shimizu N. , Konno N. , Matsuda K.
Published: April 2012

The structure and immunolocalization of the ion transporters Na+,K+‐ATPase (NKA), Na+/H+ exchanger (NHE3) and vacuolar‐type H+‐ATPase (VHA) were examined in the gills of teleosts of the family Blenniidae, which inhabit rocky shores with vertical zonation in subtropical seas. These features were compared among the following species with different ecologies: the amphibious rockskipper blenny Andamia tetradactylus, the intertidal white‐finned blenny Praealticus tanegasimae and the purely marine yaeyama blenny Ecsenius yaeyamaensis. Light and electron microscopic observations indicated that thick gill filaments were arranged close to each other and alternately on two hemibranches of a gill arch in the opercular space of A. tetradactylus. Many mucous cells (MC) and mitochondrion‐rich cells (MRC) were present in the interlamellar regions of the gill filament. An immunohistochemical study demonstrated that numerous NKA, NHE3 and some VHA were located predominantly on presumed MRCs of gill filaments and at the base of the lamellae. Analyses using serial (mirror image) sections of the gills indicated that only a few NKA immunoreactive cells (IRC) were colocalized with VHA on some MRCs in the filaments. In the gills of P. tanegasimae, NKA‐ and NHE3‐IRCs were observed in the interlamellar region of the filaments and at the base of the lamellae. VHA‐IRCs were located sparsely on the lamellae and filaments. In the gills of E. yaeyamaensis, the lamellae and filaments were thin and straight, respectively. MCs were located at the tip as well as found scattered in the interlamellar region of gill filaments. NKA‐, NHE3‐ and VHA‐IRCs were moderately frequently observed in the filaments and rarely on the lamellae. This study shows that the structure and distribution of ion transporters in the gills differ among the three blennid species, presumably reflecting their different ecologies.
Chemical properties of humic matter as related to induction of plant lateral roots
Authors: Canellas L. P. , Dobbss L. B. , Oliveira A. L. , Chagas J. G. , Aguiar N. O. , Rumjanek V. M. , Novotny E. H. , Olivares F. L. , Spaccini R. , Piccolo A.
Published: April 2012

A series of humic matter samples isolated from a soil sequence, different oxisols, size‐fractionated from a vermicompost humic acid and subjected to chemical modifications, were characterized by CPMAS 13C‐NMR spectroscopy. The relative signal areas in chemical shift regions of NMR spectra of the four sets of samples were analysed by principal component analysis (PCA). Hierarchical cluster analysis (HCA) was applied to build a classification model, which allowed the recognition of humic matter according to its origin. The relationship between carbon species and biological activity of humic acids, as promoters of lateral root emergence, was obtained by applying PLS multivariate analysis. This showed that lateral root emergence was mostly related to NMR parameters such as the hydrophobicity index (HB/HI) and the 40–110 and 160–200 ppm chemical shift regions (hydrophilic carbon HI), while the content of hydrophobic (HB) carbon in humic samples was negatively correlated with induction of lateral root hair. Our results represent a step further in the structure‐bioactivity relationship of natural humic substances and confirm their role as plant root growth promoters.
Bimodal transparency as an indicator for alternative states in South American lakes
Authors: KOSTEN SARIAN , VERNOOIJ MARTINE , VAN NES EGBERT H. , SAGRARIO MARÍA DE LOS Á. G. , CLEVERS JAN G. P. W. , SCHEFFER MARTEN
Published: April 2012

1. The alternative state theory claims that shallow lakes may have either clear water, and be dominated by submerged macrophytes, or turbid water and be dominated by phytoplankton. Most evidence for this theory comes from studies in temperate or boreal regions of Europe. Because of differences in the strength of trophic interactions, such as in the pressure of zooplankton grazing on phytoplankton, this influential theory might not apply elsewhere.

2. Here, we test the theory for South American lakes, combining field data and Landsat satellite data. We studied the frequency distribution of primary producers and water transparency, looking for potential bimodality separating clear and turbid lakes. A bimodal distribution might be observed if there are indeed alternative states, although would not itself be sufficient evidence for the theory. Possible shifts between alternative states were analysed by comparing satellite data from 1987 to 2005.

3. In our field data, there was a bimodal pattern in phytoplankton abundance and possibly in the abundance of submerged macrophytes, but not in water transparency. Analyses of the larger satellite data set revealed bimodality in lake transparency in 2005, but less so in 1987. In 1987, the lakes were generally clearer, and the transition to higher turbidity was more gradual than in 2005. The stronger bimodality in the more recent data, and the overall lower transparency, could have been caused by an increase in fertiliser use and subsequent eutrophication but also by differences in hydrology. Further, 1987 was much wetter than 2005, which could have caused dilution of suspended particles, leading to clearer water.

4. While a bimodal distribution in the abundance of primary producers and water clarity is not decisive evidence for or against the theory of alternative states, our data clearly fail to refute it.
Increasing trends in childlessness in recent birth cohorts – a registry‐based study of the total Danish male population born from 1945 to 1980
Authors: Priskorn L. , Holmboe S. A. , Jacobsen R. , Jensen T. K. , Lassen T. H. , Skakkebaek N. E.
Published: April 2012

The fertility rate has recently declined in many parts of the World, including Europe. To a large extent, this change can be explained by the socio‐economic development. However, increasing fertility problems and widespread occurrence of poor semen quality could in part explain the few births. The objective of this registry based study was to investigate birth cohort related trends in fertility and childlessness among Danish men. The study population comprised all 1 616 677 men in Denmark born from 1945 to 1980 of whom 1 359 975 (84.1%) were native Danes. Data were obtained from Statistics Denmark and contained information from The National Danish Birth Registry and The Danish In Vitro Fertilization (IVF) Registry. For consecutive birth cohorts of native Danish men cumulative fertility rates at age 45 declined from 1.91 children per man in the 1945 birth cohort to 1.71 for men born in 1960. The proportion of childless men at age 45 increased from 14.8% to 21.9% in the same birth cohorts. Assisted reproductive technology (ART) seemed to compensate partly for the lower fertility and to reduce the proportion of childless men. In contrast, recent reports on corresponding birth cohorts of Danish women showed that the proportion remaining childless throughout life has been lower than in men and has not shown a similar increase. In conclusion, using unique Danish registries the study showed a birth cohort related decline in fertility rates and an increase in childlessness among men. In the more recent cohorts more than one in five men remained childless. The causes behind the findings are likely multi‐factorial. Hitherto, most attention has been given to socio‐economic factors which undoubtedly play a major role. Our findings lend support to the hypothesis that the high prevalence of low sperm counts among young Danish men may be a contributing factor.
Reduced artery diameters in Klinefelter syndrome
Authors: Foresta C. , Caretta N. , Palego P. , Ferlin A. , Zuccarello D. , Lenzi A. , Selice R.
Published: April 2012

Various epidemiological studies in relatively large cohorts of patients with Klinefelter syndrome (KS) described the increased morbidity and mortality in these subjects. Our aim was to study the structure and function of arteries in different districts to investigate in these subjects possible alterations. A total of 92 patients having non‐mosaic KS, diagnosed in Centre for Human Reproduction Pathology at the University of Padova, and 50 age‐matched healthy male controls were studied. Klinefelter syndrome subjects and controls evaluation included complete medical history, physical examination, measurement of concentrations of the reproductive hormones, lipidic and glycidic metabolism, AR function and sensitivity, ultrasound examinations (diameters, carotid intima‐media thickness and brachial flow‐mediated dilation) of brachial, common carotid and common femoral artery and abdominal aorta. Klinefelter syndrome patients showed significantly reduced artery diameters in all districts evaluated. On the contrary no statistically significant difference was found in cIMT and brachial FMD values between KS patients and controls. Furthermore, we found no statistically significant correlation of artery diameters with reproductive hormones, metabolic parameters, anthropometric measures and weighted CAG repeats. To our knowledge, this is the first study finding a reduced artery diameter in several districts in KS patients compared with that of normal male subjects and overlapping to that of female subjects. We have not an explanation for this phenomenon, even if a possible involvement of genes controlling the development of vascular system might be hypothesized, and further research is required to verify this hypothesis.
Pretreatment of aqueous pectin solution by cross‐flow microfiltration: analysis of operational parameters, degree of concentration and pectin losses
Authors: da Silva Vítor R. , Hamerski Fabiane , Scheer Agnes P.
Published: April 2012

Obtaining pectin through traditional precipitation processes requires a large amount of organic solvent. A reduction in solvent consumption may be achieved by incorporating a cross‐flow microfiltration step in which the extraction solution is removed and pectin is concentrated. In this study, we used α‐alumina tubular membrane (0.44 μm) in two operation modes: total recycle mode to evaluate the effect of temperature, initial concentration of pectin and transmembrane pressure on the permeate flux and pectin coefficient rejection; and batch mode to evaluate the degree of concentration and loss of pectin. It was observed that pectin coefficient rejection varied from 93.4 ± 0.7% to 97.8 ± 0.3%, and a maximum permeate flux of 238.69 ± 6.48 kg m−2 h−1 with 0.12 MPa at 50 °C and 1.0 g kg−1. Using the optimum conditions, the flux observed at the end of the process was 32.8% lower than the flux in the total recycle mode, enabling a final concentration of pectin in the retained solution of 61.04 ± 0.87% with an average pectin loss in the permeate stream of 8.18%.
Effect of processing of corn for production of masa, tortillas and tortilla chips on the scavenging capacity of reactive nitrogen species
Authors: López‐Martínez Leticia X. , Parkin Kirk L. , Garcia Hugo S.
Published: April 2012

The effect of processing conventional and pigmented corn into masa, tortilla and tortilla chips on the ability to scavenge nitric oxide (NO) and peroxynitrite (ONOO−) was investigated. The level of retention of nitric oxide and peroxynitrite (mediated for inhibition of nitrite formation scavenging capacity for masa, tortilla and tortilla chips) ranged 56.2–78.2%, 67.4–45%, 40.3–62.0% (for nitric oxide) and 38.6–81.7%, 23.3–47.7%, 19.3–67.2% (for inhibition of nitrite formation), respectively. The antinitrosative activities were affected significantly (P > 0.05) by nixtamalisation, but not by processing masa into tortilla and tortilla chips (P > 0.05). The yellow variety and its corresponding products showed the greatest capacity to scavenge nitric oxide and inhibition of nitrite formation among conventional varieties and the purple variety ranked highest among the pigmented varieties.
Influence of pH on colour and iron content of peptide fractions obtained from bovine Hb concentrate hydrolysates
Authors: Cian Raúl E. , Drago Silvina R. , González Rolando J.
Published: April 2012

The effect of pH on colour and iron content (Fe) of peptide fractions obtained from bovine haemoglobin concentrate (BHC) hydrolysates was studied. Four hydrolysates were obtained using three enzymes: Protex‐6‐L (P), Fungal–Protease–Concetrate (FC) and Flavourzyme (F). BHC and its hydrolysates (P, FC, P + F, FC + F) were fractioned at pH 4.5, 7.0 and 9.5. Solubility and Fe from different fractions were measured. Correlations between CIELAB colour parameters and Fe from different fractions were analysed. The colour from different fractions varied from red to yellow (a* and b* positives). Lightness values (L*) ranged from twenty‐four to seventy. FC4.5 and FC + F4.5 fractions were the clearest and yellow (higher L*, b*, h), while BHC9.5 and P + F9.5 fractions had the lowest values of L*, b* and h. There was an inverse linear relationship between b* and L* parameters and Fe from fractions. This relationship could be associated with the pH of extraction. As pH increases Fe significantly increases and lower b* and L* values were obtained.
Unravelling stability‐complexity relationships
Authors: Hastings Alan
Published: April 2012

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[ The consumer Ceriodaphnia reticulata. This experiment used a very similar species to the one shown here, namely Ceriodaphnia reticulata. This freshwater cladoceran grazer can consume phytoplankton species that have a maximal axial dimension of upto ∼35 μm. As a result, Pediastrum simplex (CPCC 431), Fragilaria crotonensis (CPCC 269), Asterionella formosa (CPCC 605), and Staurastrum pingue (UTEX1606) would have inedible for Ceriodaphnia dubia. Ankistrodesmus falcatus (UTEX 101) may also have been selected against in some instances due to its large size. Neither C. dubia density nor stability were affected by resource species diversity, although resource community composition did matter. ]

Narwani, A. & Mazumder, A. (2012) Bottom‐up effects of species diversity on the functioning and stability of food webs. Journal of Animal Ecology, 81, 702–714.

Defining the characteristics of persistent species assemblages is a major focus in ecology. A key set of questions is: how to scale up from interactions between two species to multiple species, what is the role of species characteristics in coexistence and what are the ecosystem level consequences of the characteristics of coexistence. Narwani & Mazumder use meticulous experimental work to look at these three questions simultaneously using carefully controlled microcosms. A key finding is that the relationships between stability and diversity as measured by effects on different trophic levels and different aspects of ecosystem function depend critically on the community composition. The particular species involved are more important than the overall diversity.
Wearing of complete dentures reduces slow fibre and enhances hybrid fibre fraction in masseter muscle
Authors: CVETKO E. , KAREN P. , ERŽEN I.
Published: April 2012

Summary Edentulous conditions and use of complete dentures alter the function of jaw muscles, which is presumably reflected in the myosin heavy chain (MyHC) isoform composition. This study is the first dealing with MyHC isoforms expression in edentulous persons with the aim to clarify to which extent the decreased functional load following teeth loss contributes to the changed muscle phenotype during ageing. We analysed MyHC expression in old masseter muscle at decreased and full functional load by comparing age‐matched edentulous and dentate subjects. Edentulous subjects had upper and lower complete dentures. Dentate subjects had at least 24 natural teeth in continuous dental arches with two molars present in each quadrant and normal intermaxillary relationship. The adaptive response to the reduced masticatory load was lower numerical and area proportion of MyHC‐1 expressing fibres and higher numerical proportion of hybrid fibres in edentulous compared with dentate subjects with no significant difference in the proportion of MyHC‐neo‐expressing fibres between both groups. We conclude that the observed differences in the proportion of fibre types between denture wearers and dentate subjects cannot be ascribed to degenerative changes intrinsic to the ageing muscle, but to functional differences in muscle activity and to morphological alterations of stomatognathic system accompanying the complete teeth loss.
Are bruxism and the bite causally related?
Authors: LOBBEZOO F. , AHLBERG J. , MANFREDINI D. , WINOCUR E.
Published: April 2012

Summary  In the dental profession, the belief that bruxism and dental (mal‐)occlusion (‘the bite’) are causally related is widespread. The aim of this review was to critically assess the available literature on this topic. A PubMed search of the English‐language literature, using the query ‘Bruxism [Majr] AND (Dental Occlusion [Majr] OR Malocclusion [Majr])’, yielded 93 articles, of which 46 papers were finally included in the present review*. Part of the included publications dealt with the possible associations between bruxism and aspects of occlusion, from which it was concluded that neither for occlusal interferences nor for factors related to the anatomy of the oro‐facial skeleton, there is any evidence available that they are involved in the aetiology of bruxism. Instead, there is a growing awareness of other factors (viz. psychosocial and behavioural ones) being important in the aetiology of bruxism. Another part of the included papers assessed the possible mediating role of occlusion between bruxism and its purported consequences (e.g. tooth wear, loss of periodontal tissues, and temporomandibular pain and dysfunction). Even though most dentists agree that bruxism may have several adverse effects on the masticatory system, for none of these purported adverse effects, evidence for a mediating role of occlusion and articulation has been found to date. Hence, based on this review, it should be concluded that to date, there is no evidence whatsoever for a causal relationship between bruxism and the bite.
Decreased chewing activity during mouth breathing
Authors: HSU H.‐Y. , YAMAGUCHI K.
Published: April 2012

Summary  This study examined the effect of mouth breathing on the strength and duration of vertical effect on the posterior teeth using related functional parameters during 3 min of gum chewing in 39 nasal breathers. A CO2 sensor was placed over the mouth to detect expiratory airflow. When no airflow was detected from the mouth throughout the recording period, the subject was considered a nasal breather and enrolled in the study. Electromyographic (EMG) activity was recorded during 3 min of gum chewing. The protocol was repeated with the nostrils occluded. The strength of the vertical effect was obtained as integrated masseter muscle EMG activity, and the duration of vertical effect was also obtained as chewing stroke count, chewing cycle variation and EMG activity duration above baseline. Baseline activity was obtained from the isotonic EMG activity during jaw movement at 1·6 Hz without making tooth contact. The duration represented the percentage of the active period above baseline relative to the 3‐min chewing period. Paired t‐test and repeated analysis of variance were used to compare variables between nasal and mouth breathing. The integrated EMG activity and the duration of EMG activity above baseline, chewing stroke count and chewing cycle significantly decreased during mouth breathing compared with nasal breathing (P < 0·05). Chewing cycle variance during mouth breathing was significantly greater than nasal breathing (P < 0·05). Mouth breathing reduces the vertical effect on the posterior teeth, which can affect the vertical position of posterior teeth negatively, leading to malocclusion.