bluuebunny/crossref_metadata_2025 huggingface dataset:
Novel globoside‐like oligosaccharide expression patterns in nontypeable Haemophilus influenzae lipopolysaccharide
Authors: Lundström Susanna L. , Twelkmeyer Brigitte , Sagemark Malin K. , Li Jianjun , Richards James C. , Hood Derek W. , Moxon E. Richard , Schweda Elke K. H.
Published: August 2007

We report the novel pattern of lipopolysaccharide (LPS) expressed by two disease‐associated nontypeable Haemophilus influenzae strains, 1268 and 1200. The strains express the common structural motifs of H. influenzae; globotetraose [β‐d‐GalpNAc‐(1→3)‐α‐d‐Galp‐(1→4)‐β‐d‐Galp‐(1→4)‐β‐d‐Glcp] and its truncated versions globoside [α‐d‐Galp‐(1→4)‐β‐d‐Galp‐(1→4)‐β‐d‐Glcp] and lactose [β‐d‐Galp‐(1→4)‐β‐d‐Glcp] linked to the terminal heptose (HepIII) and the corresponding structures with an α‐d‐Glcp as the reducing sugar linked to the middle heptose (HepII) in the same LPS molecule. Previously these motifs had been found linked only to either the proximal heptose (HepI) or HepIII of the triheptosyl inner‐core moiety l‐α‐d‐Hepp‐(1→2)‐[PEtn→6]‐l‐α‐d‐Hepp‐(1→3)‐l‐α‐d‐Hepp‐(1→5)‐[PPEtn→4]‐α‐Kdo‐(2→6)‐lipid A. This novel finding was obtained by structural studies of LPS using NMR techniques and ESI‐MS on O‐deacylated LPS and core oligosaccharide material, as well as electrospray ionization‐multiple‐step tandem mass spectrometry on permethylated dephosphorylated oligosaccharide material. A lpsA mutant of strain 1268 expressed LPS of reduced complexity that facilitated unambiguous structural determination. Using capillary electrophoresis‐ESI‐MS/MS we identified sialylated glycoforms that included sialyllactose as an extension from HepII, this is a further novel finding for H. influenzae LPS. In addition, each LPS was found to carry phosphocholine and O‐linked glycine. Nontypeable H. influenzae strain 1200 expressed identical LPS structures to 1268 with the difference that strain 1200 LPS had acetates substituting HepIII, whereas strain 1268 LPS has glycine at the same position.
Post‐translational modifications in the active site region of methyl‐coenzyme M reductase from methanogenic and methanotrophic archaea
Authors: Kahnt Jörg , Buchenau Bärbel , Mahlert Felix , Krüger Martin , Shima Seigo , Thauer Rudolf K.
Published: August 2007

Methyl‐coenzyme M reductase (MCR) catalyzes the methane‐forming step in methanogenic archaea. Isoenzyme I from Methanothermobacter marburgensiswas shown to contain a thioxo peptide bond and four methylated amino acids in the active site region. We report here that MCRs from all methanogens investigated contain the thioxo peptide bond, but that the enzymes differ in their post‐translational methylations. The MS analysis included MCR I and MCR II from Methanothermobacter marburgensis, MCR I from Methanocaldococcus jannaschii and Methanoculleus thermophilus, and MCR from Methanococcus voltae, Methanopyrus kandleri and Methanosarcina barkeri. Two MCRs isolated from Black Sea mats containing mainly methanotrophic archaea of the ANME‐1 cluster were also analyzed.
Protein transport in chloroplasts − targeting to the intermembrane space
Authors: Vojta Lea , Soll Jürgen , Bölter Bettina
Published: August 2007

The import of proteins destined for the intermembrane space of chloroplasts has not been investigated in detail up to now. By investigating energy requirements and time courses, as well as performing competition experiments, we show that the two intermembrane space components Tic22 and MGD1 (E.C. 2.4.1.46) both engage the Toc machinery for crossing the outer envelope, whereas their pathways diverge thereafter. Although MGD1 appears to at least partly cross the inner envelope, Tic22 very likely reaches its mature form in the intermembrane space without involving stromal components. Thus, different pathways for intermembrane space targeting probably exist in chloroplasts.
High incidence of thyroid cancer in toxic multinodular goiters
Authors: SHAIKH Irshad Ahammed , MUTHUKUMARSAMY Girivasan , VIDYADHARAN Ramesh , ABRAHAM Santhosh John
Published: August 2007

Aim:  The aim of this study is to analyse the incidence of carcinoma thyroids in toxic multinodular goiters (MNG) and the pathological pattern of these cancer nodules.

Methods:  This is a retrospective review of 2344 patients, operated for MNG over a period of 10 years from January 1993 to December 2002 at Lourdes Hospital, Kochi, Kerala, India.

Results:  We operated on 2344 patients for MNG, out of whom 160 patients presented to us in a toxic state and the remaining 2184 in a non‐toxic state. Of the patients operated for MNG 4.5% were found to have associated thyroid cancer. The incidence of thyroid cancer in toxic MNG patients was 26.25% whereas in non‐toxic MNG patients it was 2.5%. All the malignant nodules detected were papillary cancers of the thyroid and relatively large nodules (range 0.6 cm−4.1 cm) were found in toxic MNG compared to non‐toxic MNG.

Conclusion:  Patients with toxic MNG showed a very high incidence of coexisting thyroid cancer. Thyroid cancers can coexist in toxic MNG despite the suppression of thyroid stimulating hormone (TSH). The coexisting thyroid cancer size is larger in toxic MNG than euthyroid MNG. A total thyroidectomy is the treatment recommended for toxic MNG in an endemic area.
Primary carcinoma of gallbladder in Yazd, Iran: A 14‐year study (1992–2006)
Authors: SALARI Ali Akbar , TAGHIPOOR Shokouh , AMIR Hassan
Published: August 2007

Aim:  To investigate the clinico‐pathological profile and stage of disease at presentation of patients with carcinoma of the gallbladder diagnosed during 1992–2006 in Iran.

Methods:  During this study period 34 consecutive patients with gallbladder carcinoma were identified using a pathology‐based tumor database. The data extracted for each study patient included their gender, age at diagnosis, signs and symptoms, presence of gallstones and histopathological pattern of the gallbladder carcinoma and the UICC/AJCC TNM staging system was used for labeling the stages of the disease.

Results:  The median age of the 34 patients studied was 69.50 with most between 61 and 70 years of age. The age range of the men was between 53 and 80 years with a median age of 71.50 years and that of the women was between 33 and 79 years with a median age of 68.50 years. The most common symptom was pain in the right hypochondrium. More women had gallstones (15/34) than men (3/10). Adenocarcinoma was the most common histopathological type (91.18%) with the commonest subtype being papillary (47.06%). Eighteen patients had stage IB and stage IIA (52.94%) carcinomas whereas stages IIB and III were observed in six (17.6%) and seven cases (20.6%), respectively. Only three cases (8.82%) were seen in stage IV. The follow up of gall bladder carcinoma (GBC) patients in this study ranged from 6 to 60 months. However, there was a progressive reduction of patients attending follow‐up oncology clinic, particularly by those who had stages III and IV of the disease.

Conclusion:  Most patients (52.94%) presented with early disease (stage IB and IIA) which carries a good prognosis. Early detection of GBC and a national consensus for the evidence‐based management of GBC in Iran should be the major components of a strategy aimed at improving therapeutic outcome.
THE QUALITY OF VEGETABLE OIL FROM THREE VARIETIES OF SUNFLOWER SEEDS (HELIANTHUS ANNUUS)
Authors: GALLEGOS‐INFANTE JOSÉ‐ALBERTO , ROCHA‐GUZMÁN NURIA‐ELIZABETH , GONZÁLEZ‐LAREDO RUBÉN‐FRANCISCO , GOMEZ‐SÁNCHEZ DANIEL , ZUNO‐FLORIANO FABIOLA , VIDAÑA‐MARTÍNEZ SILVIA‐ADRIANA
Published: August 2007

Vegetable oils become susceptible to oxidation during their processing. The appropriate extraction and refining conditions of oil from two experimental cultivars (Madero‐91 and Cianoc‐2) of sunflower seeds and a commercial one (Victoria) as a control, were studied. Isopropyl alcohol was used in the extraction and refining, and compared with hexane. The refining was performed by the miscella method at 40, 50, 60 and 70%. Free fatty acids (FFA) and malonaldehyde analysis of crude oils afforded no significant differences among solvents and sunflower varieties. In refined oils, differences found with the miscella concentration, the malonaldehyde content and FFA content were not significant. Cianoc‐2 was the best source for oil production because of its lower values in FFA and malonaldehyde content.

PRACTICAL APPLICATIONS

The use of hexano in refining vegetable oil in Mexico is common, lack of knowledge about the use of new solvents and their impact on the processing conditions with sunflower seed cultivars is lack. The present work describes at lab scale, the work conditions, advantages and posibilities and limitations of the use on isopropyl alcohol in comparison with hexane and the use of three Mexican cultivar with this approach, with emphasize in oxidation conditions of refined vegetable oil.
PRELIMINARY EVALUATION OF THE APPLICATION OF THE FTIR SPECTROSCOPY TO CONTROL THE GEOGRAPHIC ORIGIN AND QUALITY OF VIRGIN OLIVE OILS
Authors: BENDINI ALESSANDRA , CERRETANI LORENZO , DI VIRGILIO FABIO , BELLONI PAOLO , BONOLI‐CARBOGNIN MATTEO , LERCKER GIOVANNI
Published: August 2007

A rapid Fourier transform infrared (FTIR) attenuated total reflectance spectroscopic method was applied to determine qualitative parameters such as free fatty acid (FFA) content and the peroxide value (POV) in virgin olive oils. Calibration models were constructed using partial least squares regression on a large number of virgin olive oil samples. The best results (R2 = 0.955, root mean square error in cross validation [RMSECV] = 0.15) to evaluate FFA content expressed in oleic acid % (w/w) were obtained considering a calibration range from 0.2 to 9.2% of FFA relative to 190 samples. For POV determination, the result obtained, built on 80 olive oil samples with a calibration range from 11.1 to 49.7 meq O2/kg of oil, was not satisfactory (R2 = 0.855, RMSECV = 3.96). We also investigated the capability of FTIR spectroscopy, in combination with multivariate analysis, to distinguish virgin olive oils based on geographic origin. The spectra of 84 monovarietal virgin olive oil samples from eight Italian regions were collected and elaborated by principal component analysis (PCA), considering the fingerprint region. The results were satisfactory and could successfully discriminate the majority of samples coming from the Emilia Romagna, Sardinian and Sicilian regions. Moreover, the explained variance from this PCA was higher than 96%.

PRACTICAL APPLICATIONS

The verification of the declared origin or the determination of the origin of an unidentified virgin olive oil is a challenging problem. In this work, we have studied the applicability of Fourier transform infrared coupled with multivariate statistical analysis to discriminate the geographic origin of virgin olive oil samples from different Italian regions.
NONTHERMAL STERILIZATION OF GREEN COCONUT WATER FOR PACKAGING
Authors: REDDY KAMIDI VENKAT , DAS MADHUSWETA , DAS SUSANTA KUMAR
Published: August 2007

A laboratory scale technique for nonthermal sterilization of green coconut water was developed. The process consisted of two‐stage filtrations under constant pressure using different filter media; namely, low ash filter paper (Whatman 42) in the first stage and cellulose nitrate membrane (0.2‐µm pore opening) in the second stage. The quality of the filtered water was evaluated with respect to microbial population, organoleptic characteristics, nutrient contents and physical properties.

The water after the second stage of filtration was sterile with no visible growth of microbes on culture plates. The taste of the processed water did not change significantly; however, the flavor and overall acceptability decreased about 9 and 11%, respectively. The water also remained sterile after 1 month in aseptically packed condition, but overall acceptability further decreased by 6%. The filtration reduced different nutrients of the fresh water like fat, ash, total sugar, reducing sugar and protein by 40.0, 43.9, 23.4, 29.2 and 13.3%, respectively; the removal of K, Mg, Ca, Fe and Cu was 10.15, 16.14, 19.04, 20.85 and 22.21%, respectively. The removal of these nutrients increased surface tension and decreased viscosity of the coconut water.

PRACTICAL APPLICATIONS

Packaging of sterile green coconut water as soft drink has a good global market as it ensures its widespread availability, quantity and reasonable price. Non‐thermal sterilization by membrane filtration has been found to be an alternative to thermal sterilization as the later adversely deteriorates many essential qualities of this delicate coconut water. The present non‐thermal sterilization technique maintained the sterility, nutritional quality and desirable organoleptic profile of the processed water. Thus, this process could be applied for production of green coconut water as packaged soft drink.
DETERMINATION OF TRACE AMOUNT FOR GERMANIUM (Ge) BY ATOMIC FLUORESCENCE SPECTROMETRY IN RICE (ORYZA SATIVA L.)
Authors: JIANG S.L. , SHI C.H. , WU J.G.
Published: August 2007

The quantification of germanium in rice (Oryza sativa L.) was studied by atomic fluorescence spectrometry (AFS). The optimum experimental conditions or the generation of germanium hydride were 360‐V photomultiplier tube voltage, 80‐mA hollow cathode lamp, 2.5% (w/v) KBH4 in 0.5% KOH solution and 20% H3PO4 mixture with 5% H2SO4. With these experimental conditions, the correlation coefficient (R2) of calibration curve was up to 0.9992. As a convenient and sensitive calibration curve, it was proposed for the determination of trace amounts of germanium in brown and milled rice samples. The results showed that the content of germanium in brown rice was higher than that in milled rice. The means of the content of germanium were 4.98 and 18.10 ng/g in milled rice and brown rice, respectively.

PRACTICAL APPLICATIONS

Rice is an important food for human nutrition because it supplies starch, protein and the majority of micronutrients to humans, particularly in Asia. So determination the content of Germanium in rice is important for human health. In this study, we developed the method of AFS which was suitable for determination rice grain. With this method, the content of Ge could be analyzed accurately in rice, so that the good materials would be selected form germplasm resources of rice, which could be used to study physiological and genetic mechanisms and enhance germanium in diets for human.
CONTAMINATION AND DECONTAMINATION OF POULTRY CARCASS NECK TISSUE
Authors: McMEEKIN T. A. , THOMAS C. J. , PENNINGTON P. I.
Published: August 2007

Water absorption and changes in surface microtopography are major determinants of contamination of the underside of neck tissue. Salmonella cells adhere firmly to this tissue but cannot be effectively removed because of the major contribution of physical entrapment to the overall level of contamination. Heat and/or sorbate treatments can bring the bacteriological quality of neck tissue to that of the rest of the carcass but removal of this tissue is the most effective means of decontamination.
INTERVENTION AS THE RATIONAL APPROACH TO CONTROL DISEASES OF MICROBIAL ETIOLOGY TRANSMITTED BY FOODS. An actualization of the tale of the frog and the grouse—after Lafontaine (1621–1695).1
Authors: MOSSEL D. A. A.
Published: August 2007

Even advanced countries suffer from infectious diseases spread by food animal origin. The underlying mechanism of this morbidity is known and is important to design measures to reduce the incidence via intervention sensu Wilson (1955).

The classical defense lines which rely on high‐level hygiene in the slaughter‐house and during food preparation are insufficient to control these food transmitted enteric infections. Consequently, a third line of defense, processing for safety, is required here as it was in the dairy and the egg product industries. At least two effective modes of processing for safety of raw food animal origin are available to erect this third line of defense. These includ radicidation and lactic acid decontamination. The two procedures lead to marked reward in terms of control of infection, while they are both fully safe.

It is the duty of Public Health bacteriologists to advise regulatory agenci and consumers in applying one or both of these measures for improved healt protection.

The health profession cannot possibly hope to achieve this goal without recruiting the assistance of experts in human behavior and more particular in factors determining selection and rejection of foods by consumers.
PRODUCTION AND CHARACTERIZATION OF ANTIBODY AGAINST STERIGMATOCYSTIN
Authors: LI YAGUAN , CHU F. S.
Published: August 2007

Conjugation of sterigmatocystin (ST) to bovine serum albumin (BSA) was achieved by converting ST to its hemiacetal followed by a reductive alkylation method under conditions similar to those for the preparation of afla B2a‐BSA conjugate. Useful antibody was obtained from rabbits 6 weeks after they were immunized with BSA‐ST conjugate. Antibody titers reached maxima (1:51,200) 10–12 weeks after immunization. ELISA analysis revealed that the dehydro‐ST is about 16 times less reactive with the antibody than is ST. The antibody practically has no cross reaction with aflatoxins B1, B2a, G1, G2, and M1, and 6‐0‐methyl‐ST.
ANTIMICROBIAL ACTIVITY OF SOME FOOD FLAVORING COMPOUNDS
Authors: JAY JAMES M. , RIVERS GAIL M.
Published: August 2007

Of 21 food flavoring compounds tested against 39–40 organisms, 10 were ineffective at 1,000 ppm or 10 mM either at pH 6 or 8 and by either surface plating or in broth. The 11 effective compounds were d‐ and l‐carvone, diacetyl, ethyl vanillin, eugenol, maltol, menthol, phenylacetic acid, phenylacetal‐dehyde, 2,3‐pentanedione and vanillin; with diacetyl and eugenol being the most effective. All were more effective at pH 6 than at pH 8. With the exception of maltol and phenylacetic acid, each was generally more effective against fungi than bacteria with the lactic acid bacteria being the most resistant. At pH 5.5 and 5°C, diacetyl was inhibitory to Pseudomonas fluorescens and P. geniculata at < 10 ppm. The findings suggest that compounds used in acid foods, ostensibly as flavoring agents, may exert antimicrobial effects when considered in context with all parameters of growth.
Characteristics of nurse practitioner curricula in the United States related to antimicrobial prescribing and resistance
Authors: Sym Donna , Brennan Caitlin W. , Hart Ann Marie , Larson Elaine
Published: August 2007

Purpose: The purpose of this study was to examine current nurse practitioner (NP) curricula in the United States with regard to antibiotics and antimicrobial resistance and assess the need for a web‐based module for instruction on antimicrobial resistance and appropriate prescribing of antibiotics.

Data sources: A 22‐item, anonymous, self‐administered, web‐based survey was sent to 312 NP programs; 149 (48%) responded. Survey items included questions related to NP specialties offered, program accreditation, format of pharmacology course(s), lecture hours related to antimicrobial therapy, and whether the participant would use a Web‐based module to teach NP students about antimicrobial resistance, if one were available.

Conclusions: Most NP programs (99.3%) required a pharmacology course, and 95% had lectures dedicated to antimicrobial therapy. Half of the programs (53.5%) devoted ≥4 lecture hours to antimicrobial therapy in the pharmacology course, and most (84.8%) reported covering antimicrobial therapy in nonpharmacology courses as well. Approximately half of the programs (45.3%) reported <4 h of lecture on antimicrobial therapy in nonpharmacology courses. Many programs (51.9%) did not offer a microbiology course; 39.2% required microbiology as a prerequisite. Most respondents (86.7%) were familiar with the Centers for Disease Control and Prevention antimicrobial resistance program, and 92.6% reported that they would use an electronic module regarding resistance.

Implications for practice: NP curricula generally include <10 h of content on antimicrobial therapy. An electronic module regarding antimicrobial resistance is likely to be a useful and relevant adjunct to current curricula.
Many asthma patients experience persistent symptoms despite appropriate clinical and guideline‐based treatment with inhaled corticosteroids
Authors: Mogil Joan
Published: August 2007

Purpose: To review possible reasons for persistence of asthma symptoms despite appropriate use of clinical and guideline‐based treatments, including the use of inhaled corticosteroids.

Data sources: Review of the worldwide scientific literature on factors related to persistent symptoms in patients with asthma.

Conclusions: Patients with asthma may not respond as expected to therapy because of factors that include poor adherence, improper inhaler technique, persistent exposure to symptom triggers, and limitations of current standard therapy, including steroid insensitivity or the steroid plateau effect. Persistent symptoms may also be associated with IgE‐mediated airway inflammation, as current standard asthma therapies do not directly address the IgE‐mediated component of the inflammatory cascade. Asthma is a complex disease and its treatment requires the full cooperation and participation of the patient.

Implications for practice: Healthcare professionals can play a key role by educating patients and their family members about the nature of asthma and rationale for treatment, supporting the importance of strict adherence to prevention measures and the prescribed treatment regimen.
Budd–Chiari syndrome from an advanced practice nurse perspective
Authors: Pahuriray Lourdes S. , Alpert Patricia T. , Kowalski Susan
Published: August 2007

Purpose: To provide nurse practitioners (NPs) with a case study and literature review of Budd–Chiari syndrome (BCS). This rare liver disease has a multitude of clinical presentations that NPs may encounter in the primary care setting.

Data source: A literature search was conducted in Pub‐Med and CINAHL using key search words. Information for the case study was obtained from a patient and his gastroenterology specialist, who is a foremost expert in this field.

Conclusion: BCS is complex and may be difficult to diagnose because of its atypical clinical presentation. Delayed diagnosis can affect the quality and quantity of a patient’s life. Increasing NPs’ awareness about this rare condition through a case presentation and review of the literature emphasizes the major factors for accurate diagnosis.

Implications for practice: Knowledge of BCS can assist the NP in identifying this syndrome and making prompt, appropriate referrals.
Immunoglobulin E‐mediated airway inflammation is active in most patients with asthma
Authors: Hayden Mary Lou
Published: August 2007

Purpose: To review the role of immunoglobulin E (IgE)‐mediated inflammation in the pathogenesis of asthma, limitations of standard therapies, and IgE as a logical target for therapy with omalizumab aimed at attaining asthma symptom control.

Data sources: Review of worldwide scientific literature on the role of IgE‐mediated inflammation in patients with asthma, supplemented with a clinical case study.

Conclusions: Clinical trials point to an important role for IgE blocker therapy as an add‐on to current therapy to reduce exacerbations and corticosteroid use and to improve quality of life in patients with moderate‐to‐severe asthma. Omalizumab, a monoclonal antibody that binds IgE, has been shown to be an effective, well‐tolerated treatment in these patients.

Implications for practice: A significant number of patients with moderate‐to‐severe asthma do not achieve asthma symptom control, despite adhering to current guidelines–based standards of therapy, including the use of inhaled corticosteroids, β‐agonists, and leukotriene modifiers. None of these therapies directly addresses IgE‐mediated inflammation. Therefore, patients with persistent symptoms of moderate‐to‐severe asthma should be evaluated and considered for therapy with the IgE blocker omalizumab.
Let us talk about it: Safe adolescent sexual decision making
Authors: Weiss Josie A.
Published: August 2007

Purpose: To discuss important factors that influence teens and provide guidance for nurse practitioners (NPs) to promote safe adolescent sexual decision making.

Data sources: A selective review of current professional literature and professional practice.

Conclusions: To promote safe sexual decision making in adolescents, communication with parents, other significant adults, and teens is essential. Being knowledgeable about factors that influence the choices of adolescents and willing to discuss them openly is an important component of NP practice and could make a difference in the lives of many teens.

Implications for practice: NPs are frontline healthcare providers who have many opportunities to promote safe adolescent sexual decision making. This article provides a guide to assist in this work.
Written educational materials for families of chronically ill children
Authors: Mahat Ganga , Scoloveno Mary Ann , Donnelly Cassandra Barnette
Published: August 2007

Purpose: To provide information on evaluation of written educational materials and to illustrate the evaluation of Sickle Cell Disease: A Family Guide (SCDFG) used for children with sickle cell disease (SCD) and their families. A large Valerie Fund Children’s Center developed the SCDFG in collaboration with the New Jersey Department of Health and Senior Services, Special Child Health and Early Intervention Services. Two university faculty members and one pediatric nurse practitioner (NP) working in the clinic conducted an evaluation of the effectiveness and usefulness of the SCDFG.

Data sources: Forty‐eight caregivers of children with SCD who were using the SCDFG were asked to complete a survey developed by the investigators. The survey was completed during a clinic visit.

Conclusions: The SCDFG met the standards for content, organization, layout, linguistics, visuals, readability, and comprehension. Overall, the caregivers were knowledgeable about the cause, signs and symptoms, and what to do during a sickle crisis. More than half the participants reported that they felt confident in managing their child’s problems related to SCD. Confidence of the caregivers was positively correlated with their perception that the information in the SCDFG was helpful and easy to understand.

Implications for practice: NPs need to evaluate written educational materials that are used as part of a multifaceted approach to the care of children with chronic illnesses. A planned systematic evaluation provides the NP with information about the efficacy and usefulness of the written educational materials. These materials may help empower children and caregivers to manage their long‐term illnesses.
Effects of Two Densities of Caged Monosex Nile Tilapia, Oreochromis niloticus, on Water Quality, Phytoplankton Populations, and Production When Polycultured with Macrobrachium rosenbergii in Temperate Ponds
Authors: Danaher Jason J. , Tidwell James H. , Coyle Shawn D. , Dasgupta Siddhartha , Zimba Paul V.
Published: August 2007

The effects of different densities of caged Nile tilapia, Oreochromis niloticus, on water quality, phytoplankton populations, prawn, and total pond production were evaluated in freshwater prawn, Macrobrachium rosenbergii, production ponds. The experiment consisted of three treatments with three 0.04‐ha replicates each. All ponds were stocked with graded, nursed juvenile prawn (0.9 ± 0.6 g) at 69,000/ha. Control (CTL) ponds contained only prawns. Low‐density polyculture (LDP) ponds also contained two cages (1 m3; 100 fish/cage) of monosex male tilapia (115.6 ± 22 g), and high‐density polyculture (HDP) ponds had four cages. Total culture period was 106 d for tilapia and 114 d for prawn. Overall mean afternoon pH level was significantly lower (P ≤ 0.05) in polyculture ponds than in CTL ponds but did not differ (P > 0.05) between LDP and HDP. Phytoplankton biovolume was reduced in polyculture treatments. Tilapia in the LDP treatment had significantly higher (P ≤ 0.05) harvest weights than in the HDP treatment. Prawn weights were higher (P ≤ 0.05) in polyculture than prawn monoculture. These data indicate that a caged tilapia/freshwater prawn polyculture system may provide pH control while maximizing pond resources in temperate areas.
Growth of Tiger Puffer, Takifugu rubripes, at Different Salinities
Authors: Kikuchi Kotaro , Furuta Takeshi , Ishizuka Haruo , Yanagawa Toshiharu
Published: August 2007

Two 12‐wk rearing experiments were conducted to examine the effect of rearing salinities of 10–35 ppt on the growth of 3‐ and 170‐g‐size tiger puffer, Takifugu rubripes. Fish were reared in a closed recirculation system without introducing fresh culture water at 23 C and were fed commercial pellet diet for tiger puffer twice or three times daily to apparent satiation each, almost everyday. Growth of 3‐g‐size fish seemed to increase with decreasing salinity; however, there were no significant differences in the specific growth rate and weight gain among treatments because of differences in initial body weight. Final body weight and length of fish reared at 10 ppt were significantly higher than those for fish reared at 30 ppt although initial sizes were similar. Differences were not found for the feed efficiency (FE) and daily feed consumption. Apparent relationships were not observed between salinity and blood characteristics or proximate compositions of muscle of the cultured fish. Differing from smaller fish, growth of 170‐g‐size fish tended to decrease with decreasing salinity from 30 to 10 ppt and with increasing salinity from 30 to 35 ppt. Similar trends for FE were observed.
Effect of Dietary Inclusion of N‐Acetyl Cysteine on Mucus Viscosity and Susceptibility of Rainbow Trout, Oncorhynchus mykiss, and Atlantic Salmon, Salmo salar, to Amoebic Gill Disease
Authors: Powell Mark D. , Ransome Julie , Barney Megan , Duijf Raymond M. M. , Flik Gert
Published: August 2007

The treatment of amoebic gill disease (AGD) in cultured Atlantic salmon, Salmo salar L., using mucolytic agents has been previously reported. The agent L‐cysteine ethyl ester reduces salmonid mucus viscosity and potentially increases the flushing of the gill. In the present study, the effects of the mucolytic agent N‐acetyl cysteine (NAC) were assessed. Cutaneous mucus from rainbow trout, Oncorhynchus mykiss Walbaum, and Atlantic salmon was shown to have reduced viscosity when mixed in vitro with 100 or 200 μg/mL NAC. Saltwater‐acclimated rainbow trout and Atlantic salmon were fed an oil‐incorporated, NAC‐medicated diet (8 g NAC/kg diet) for up to 24 d and challenged with inoculation of 300 cells/L Neoparamoeba spp., the etiological agent of AGD. Control fish were fed normal oil‐coated pellets and received no NAC. NAC medication failed to reduce the severity of gill lesions associated with AGD even though the mucus viscosity from medicated fish was less than that of controls. Oral NAC medication does not appear to be an effective method for controlling AGD in salmonids despite reducing cutaneous mucus viscosity.
The application of Tet repressor in prokaryotic gene regulation and expression
Authors: Bertram Ralph , Hillen Wolfgang
Published: August 2007

Inducible gene expression based upon Tet repressor (tet regulation) is a broadly applied tool in molecular genetics. In its original environment, Tet repressor (TetR) negatively controls tetracycline (tc) resistance in bacteria. In the presence of tc, TetR is induced and detaches from its cognate DNA sequence tetO, so that a tc antiporter protein is expressed. In this article, we provide a comprehensive overview about tet regulation in bacteria and illustrate the parameters of different regulatory architectures. While some of these set‐ups rely on natural tet‐control regions like those found on transposon Tn10, highly efficient variations of this system have recently been adapted to different Gram‐negative and Gram‐positive bacteria. Novel tet‐controllable artificial or hybrid promoters were employed for target gene expression. They are controlled by regulators expressed at different levels either in a constitutive or in an autoregulated manner. The resulting tet systems have been used for various purposes. We discuss integrative elements vested with tc‐sensitive promoters, as well as tet regulation in Gram‐negative and Gram‐positive bacteria for analytical purposes and for protein overproduction. Also the use of TetR as an in vivo biosensor for tetracyclines or as a regulatory device in synthetic biology constructs is outlined. Technical specifications underlying different regulatory set‐ups are highlighted, and finally recent developments concerning variations of TetR are presented, which may expand the use of prokaryotic tet systems in the future.
Metabolic engineering to enhance bacterial hydrogen production
Authors: Maeda Toshinari , Sanchez‐Torres Viviana , Wood Thomas K.
Published: August 2007

Hydrogen fuel is renewable, efficient and clean, and fermentative bacteria hold great promise for its generation. Here we use the isogenic Escherichia coli K‐12 KEIO library to rapidly construct multiple, precise deletions in the E. coli genome to direct the metabolic flux towards hydrogen production. Escherichia coli has three active hydrogenases, and the genes involved in the regulation of the formate hydrogen lyase (FHL) system for synthesizing hydrogen from formate via hydrogenase 3 were also manipulated to enhance hydrogen production. Specifically, we altered regulation of FHL by controlling the regulators HycA and FhlA, removed hydrogen consumption by hydrogenases 1 and 2 via the hyaB and hybC mutations, and re‐directed formate metabolism using the fdnG, fdoG, narG, focA, fnr and focB mutations. The result was a 141‐fold increase in hydrogen production from formate to create a bacterium (BW25113 hyaB hybC hycA fdoG/pCA24N‐FhlA) that produces the largest amount of hydrogen to date and one that achieves the theoretical yield for hydrogen from formate. In addition, the hydrogen yield from glucose was increased by 50%, and there was threefold higher hydrogen production from glucose with this strain.
Extrasynaptic and synaptic NMDA receptors form stable and uniform pools in rat hippocampal slices
Authors: Harris Alexander Z. , Pettit Diana L.
Published: August 2007

N‐methyl‐d‐aspartate receptor (NMDAR) activation can trigger both long‐ and short‐term plasticity, promote cell survival, and initiate cell death. A number of studies suggest that the consequences of NMDAR activation can vary widely depending on whether synaptic or extrasynaptic receptors are activated. Here we have examined the spatial distribution of NMDARs of CA1 pyramidal neurons in acutely dissected hippocampal slices. Using a physiological definition of extrasynaptic receptors as those not accessible to single release events, we find that extrasynaptic NMDARs comprise a substantial proportion of the dendritic NMDAR pool (36%). This pool of extrasynaptic NMDARs is stable and does not shuttle into the synaptic receptor pool, as we observe no recovery of synaptic current after MK‐801 synaptic blockade and washout. The subunit composition of synaptic and extrasynaptic NMDA receptor pools is similar at 3 weeks of age, with NR2B subunits present in both compartments. NR2B receptors are not enriched in the extrasynaptic compartment. Our data suggest that any role played by extrasynaptic NMDARs in synaptic transmission is dictated by their subcellular location rather than their subunit composition or mobility.
Impact of temperature on cross‐bridge cycling kinetics in rat myocardium
Authors: De Tombe Pieter P. , Stienen G. J. M.
Published: August 2007

The dependence of contractile properties on intracellular calcium in cardiac tissue is a highly cooperative process. Here, the temperature and calcium dependence of contractile and energetical properties in permeabilized cardiac trabeculae from rat were studied to provide novel insights into the underlying kinetic processes. Myofilament Ca2+ sensitivity significantly increased with temperature between 15 and 25°C, whereas its steepness was independent of temperature. A direct proportionality between active tension and Ca2+‐activated rate of ATP hydrolysis was observed; the slope of this relationship (tension cost) was highly temperature dependent. The rate of tension redevelopment following a quick release–restretch manoeuvre (ktr) depended in a complex manner on the level of contractile activation and on temperature. At saturating calcium levels, the temperature dependence (Q10) of ktr and Ca2+‐activated ATP hydrolysis rate were similar (Q10∼3.5), and significantly higher than the Q10 for maximum tension (Tmax; Q10∼1.3) or tension cost (Q10∼2.5). In contrast, at a low level of contractile activation (∼5% of Tmax), the Q10 of ktr was similar to that of tension cost, and significantly lower than the Q10 of Ca2+‐activated ATP hydrolysis at that level of contractile activation. Our results are consistent with the hypothesis that at high levels of contractile activation, the rates of tension redevelopment and Ca2+‐activated ATP hydrolysis are determined by both apparent cross‐bridge attachment and detachment rates, while at low levels, ktr is limited by cross‐bridge detachment rate. Tension cost, on the other hand, is determined solely by cross‐bridge detachment kinetics at all temperatures and levels of contractile activation.
Gastric motility in soluble guanylate cyclase α1 knock‐out mice
Authors: Vanneste Gwen , Dhaese Ingeborg , Sips Patrick , Buys Emmanuel , Brouckaert Peter , Lefebvre Romain A.
Published: August 2007

The principal target of the relaxant neurotransmitter nitric oxide (NO) is soluble guanylate cyclase (sGC). As the α1β1‐isoform of sGC is the predominant one in the gastrointestinal tract, the aim of this study was to investigate the role of sGC in nitrergic regulation of gastric motility in male and female sGCα1 knock‐out (KO) mice. In circular gastric fundus muscle strips, functional responses and cGMP levels were determined in response to nitrergic and non‐nitrergic stimuli. sGC subunit mRNA expression in fundus was measured by real‐time RT‐PCR; in vivo gastric emptying of a phenol red meal was determined. No changes were observed in sGC subunit mRNA levels between wild‐type (WT) and KO tissues. Nitrergic relaxations induced by short trains of electrical field stimulation (EFS) were abolished, while those by long trains of EFS were reduced in KO strips; the latter responses were abolished by 1H[1,2,4,]oxadiazolo[4,3‐a]quinoxalin‐1‐one (ODQ). The relaxations evoked by exogenous NO and the NO‐independent sGC activator BAY 41‐2272 were reduced in KO strips but still sensitive to ODQ. Relaxations induced by vasoactive intestinal peptide (VIP) and 8‐bromo‐cGMP were not influenced. Basal cGMP levels were decreased in KO strips but NO, long train EFS and BAY 41‐2272 still induced a moderate ODQ‐sensitive increase in cGMP levels. Gastric emptying, measured at 15 and 60 min, was increased at 15 min in male KO mice. sGCα1β1 plays an important role in gastric nitrergic relaxation in vitro, but some degree of nitrergic relaxation can occur via sGCα2β1 activation in sGCα1 KO mice, which contributes to the moderate in vivo consequence on gastric emptying.
The olympic brain. Does corticospinal plasticity play a role in acquisition of skills required for high‐performance sports?
Authors: Nielsen Jens Bo , Cohen Leonardo G.
Published: August 2007

Non‐invasive electrophysiological and imaging techniques have recently made investigation of the intact behaving human brain possible. One of the most intriguing new research areas that have developed through these new technical advances is an improved understanding of the plastic adaptive changes in neuronal circuitries underlying improved performance in relation to skill training. Expansion of the cortical representation or modulation of corticomotor excitability of specific muscles engaged in task performance is required for the aquisition of the skill. These changes at cortical level appear to be paralleled by changes in transmission in spinal neuronal circuitries, which regulate the contribution of sensory feedback mechanisms to the execution of the task. Such adaptive changes also appear to be essential for the consolidation of a memory of performance of motor tasks and thus for the lasting ability of performing highly skilled movements such as those required for Olympic sports.
Dependence on extracellular Ca2+/K+ antagonism of inspiratory centre rhythms in slices and en bloc preparations of newborn rat brainstem
Authors: Ruangkittisakul Araya , Secchia Lucia , Bornes Troy D. , Palathinkal Darren M. , Ballanyi Klaus
Published: August 2007

The pre‐Bötzinger Complex (preBötC) inspiratory centre remains active in isolated brainstem–spinal cords and brainstem slices. The extent to which findings in these models depend on their dimensions or superfusate [K+] and [Ca2+] (both of which determine neuronal excitability) is not clear. We report here that inspiratory‐related rhythms in newborn rat slices and brainstem–spinal cords with defined boundaries were basically similar in physiological Ca2+ (1.2 mm) and K+ (3 mm). Hypoglossal nerve rhythm was 1 : 1‐coupled to preBötC activity in slices and to cervical nerve bursts in en bloc preparations lacking the facial motonucleus (VII). Hypoglossal rhythm was depressed in brainstems containing (portions of) VII, while pre/postinspiratory lumbar nerve bursting was present only in preparations with > 79% VII. preBötC‐related slice rhythms were inhibited in 1.5 mm Ca2+ solution, whereas their longevity and burst rate were substantially augmented in 1 mm Ca2+. Ca2+ depression of slice rhythms was antagonized by raising superfusate K+ to 8–10 mm. This strong extracellular Ca2+/K+ antagonism of inspiratory (motor) rhythms was also revealed in brainstem–spinal cords without VII, while the inhibition was progressively attenuated with increasing amount of rostral tissue. We hypothesize that depression of hypoglossal rhythm and decreased Ca2+ sensitivity of preBötC rhythm are probably not related to an increased content of rostral respiratory structures, but rather to larger brainstem dimensions resulting in interstitial gradients for neuromodulator(s) and K+, respectively. We discuss whether block of pre/postinspiratory activity in preparations with < 79% VII is due to impairment of the pathway from preinspiratory interneurons to abdominal muscles
Design and Analysis of a Spherical Constant Velocity Coupling Mechanism
Authors: Kocabas Hikmet
Published: August 2007

Many constant velocity (CV) couplings have been invented in the last decade. First they are summarized including the classic double Cardan mechanism. A newly developed spherical CV coupling mechanism is then discussed and analyzed structurally and dynamically by using computer aided structural analysis and mechanism solution programs. Joint reaction forces, torques, speeds, and power consumptions are also checked. Algebraic equations of this new spherical CV coupling mechanism are derived. This mechanism has the advantage of a very compact structure and uses only standard radial bearings. It may be used wherever misaligned shafts are required.
TG‐43U1 parameterization of elongated RadioCoil brachytherapy sources
Authors: Dini Sharifeh A. , Awan Shahid B. , Dou Kai , Meigooni Ali S.
Published: August 2007

Recently, to eliminate problems associated with seed type sources, RadioMed Corporation (Tyngsboro, MA) introduced RadioCoil sources for interstitial prostate implants. The RadioCoil sources are available in integral lengths ranging from 1.0 cm to 6.0 cm. In this project, dosimetric characteristics of these sources were determined following the TG‐43U1 recommendations, with consideration of our recent publication on the evaluation of two‐dimensional anisotropy function for elongated brachytherapy sources. Dosimetric parameters of these sources were determined experimentally in Solid Water (Gammex RMI, Middleton, WI) and theoretically using Monte Carlo simulation in Solid Water and liquid water. Per the TG‐43U1 protocol, the consensus of these results would be used for their clinical applications.

PACS number: 87.53.Jw
Structure of the Zinc Transporter YiiP
Authors: Lu Min , Fu Dax
Published: August 2007

YiiP is a membrane transporter that catalyzes Zn
2+
/H
+
exchange across the inner membrane of
Escherichia coli
. Mammalian homologs of YiiP play critical roles in zinc homeostasis and cell signaling. Here, we report the x-ray structure of YiiP in complex with zinc at 3.8 angstrom resolution. YiiP is a homodimer held together in a parallel orientation through four Zn
2+
ions at the interface of the cytoplasmic domains, whereas the two transmembrane domains swing out to yield a Y-shaped structure. In each protomer, the cytoplasmic domain adopts a metallochaperone-like protein fold; the transmembrane domain features a bundle of six transmembrane helices and a tetrahedral Zn
2+
binding site located in a cavity that is open to both the membrane outer leaflet and the periplasm.
A Common Fold Mediates Vertebrate Defense and Bacterial Attack
Authors: Rosado Carlos J. , Buckle Ashley M. , Law Ruby H. P. , Butcher Rebecca E. , Kan Wan-Ting , Bird Catherina H. , Ung Kheng , Browne Kylie A. , Baran Katherine , Bashtannyk-Puhalovich Tanya A. , Faux Noel G. , Wong Wilson , Porter Corrine J. , Pike Robert N. , Ellisdon Andrew M. , Pearce Mary C. , Bottomley Stephen P. , Emsley Jonas , Smith A. Ian , Rossjohn Jamie , Hartland Elizabeth L. , Voskoboinik Ilia , Trapani Joseph A. , Bird Phillip I. , Dunstone Michelle A. , Whisstock James C.
Published: August 2007

Proteins containing membrane attack complex/perforin (MACPF) domains play important roles in vertebrate immunity, embryonic development, and neural-cell migration. In vertebrates, the ninth component of complement and perforin form oligomeric pores that lyse bacteria and kill virus-infected cells, respectively. However, the mechanism of MACPF function is unknown. We determined the crystal structure of a bacterial MACPF protein, Plu-MACPF from
Photorhabdus luminescens
, to 2.0 angstrom resolution. The MACPF domain reveals structural similarity with poreforming cholesterol-dependent cytolysins (CDCs) from Gram-positive bacteria. This suggests that lytic MACPF proteins may use a CDC-like mechanism to form pores and disrupt cell membranes. Sequence similarity between bacterial and vertebrate MACPF domains suggests that the fold of the CDCs, a family of proteins important for bacterial pathogenesis, is probably used by vertebrates for defense against infection.
The Dark Side of the Rings of Uranus
Authors: de Pater Imke , Hammel H. B. , Showalter Mark R. , van Dam Marcos A.
Published: August 2007

The rings of Uranus are oriented edge-on to Earth in 2007 for the first time since their 1977 discovery. This event provides a rare opportunity to observe their dark (unlit) side, where dense rings darken to near invisibility, but faint rings become much brighter. We present a ground-based infrared image of the unlit side of the rings that shows that the system has changed dramatically since previous views. A broad cloud of faint material permeates the system but is not correlated with the well-known narrow rings or with the embedded dust belts imaged by the Voyager spacecraft. Although some differences can be explained by the unusual viewing angle, we conclude that the dust distribution within the system has changed substantially since the 1986 Voyager encounter and that it occurs on much larger scales than has been seen in other planetary systems.