bluuebunny/crossref_metadata_2025 huggingface dataset:
Voting On Income‐Contingent Loans For Higher Education*
Authors: REY ELENA DEL , RACIONERO MARÍA
Published: June 2012

We consider risk‐averse individuals who differ in two characteristics – ability to benefit from education and inherited wealth – and analyse higher education participation under two alternative financing schemes – tax subsidy and (risk‐sharing) income‐contingent loans. With decreasing absolute risk aversion, wealthier individuals are more likely to undertake higher education despite the fact that, according to the stylised financing schemes we consider, individuals do not pay any upfront financial cost of education. We then determine which financing scheme arises when individuals are allowed to vote between schemes. We show that the degree of risk aversion plays a crucial role in determining which financing scheme obtains a majority, and that the composition of the support group for each financing scheme can be of two different types.
New Monetarist Economics: Understanding Unconventional Monetary Policy*
Authors: WILLIAMSON STEPHEN D.
Published: June 2012

This paper focuses on Federal Reserve policy in the United States after the financial crisis. Two key interventions – QE1 and QE2 – are reviewed, and a model is outlined that can be used to help understand some of the consequences of the financial crisis, and the policy responses to the crisis. Liquidity traps play an important role in the analysis, and it is shown how the financial crisis led to an unconventional liquidity shortage, requiring an unconventional policy response.
Patient‐Initiated Elective Cesarean Section of Nulliparous Women in British Columbia, Canada
Authors: Hutton Eileen K. , Kornelsen Jude
Published: June 2012

Background

The proportion of cesarean sections is increasing in Canada overall and in British Columbia in particular. It has been suggested that this increase is partially the result of women requesting the procedure, although the prevalence of patient‐initiated elective cesarean section is unclear. The objective of this study was to examine the prevalence of probable elective cesarean and physician‐suggested elective cesarean section among nulliparous women who had a cesarean section in British Columbia, Canada.

Methods

An electronic search of patient charts from seven British Columbia hospitals between June 1, 2002, and May 31, 2004, was completed and potential nulliparous women seeking elective cesarean were identified. Any women with medical factors predisposing them to a cesarean section were excluded. Identified charts were then subjected to individual chart review by two independent researchers to ensure accuracy of classification into a cohort of women with probable patient‐initiated elective cesarean section.

Results

For the study period, 10,546 nulliparous women gave birth at the seven study hospitals and 3,301 delivered by means of cesarean section. Of these 3,301 women, 36 were judged to have had a patient‐initiated elective cesarean. These 36 women represented 0.34 percent of all nulliparous births and 1.09 percent of all nulliparous cesarean births. Those judged to have selected an elective cesarean were significantly older and had babies with a lower gestational age than women with a nonelective cesarean section. No significant differences between the two groups were found with respect to maternal weight, length of stay for the mother or baby, newborn birthweight, or special care nursery days.

Conclusions

Overall, the prevalence of nulliparous women judged to have had a patient‐initiated elective cesarean was found to be low and is not likely to be substantially contributing to the rising proportion of cesarean births. (BIRTH 39:3 September 2012)
Epileptic encephalopathies of the Landau‐Kleffner and continuous spike and waves during slow‐wave sleep types: Genomic dissection makes the link with autism
Authors: Lesca Gaetan , Rudolf Gabrielle , Labalme Audrey , Hirsch Edouard , Arzimanoglou Alexis , Genton Pierre , Motte Jacques , de Saint Martin Anne , Valenti Maria‐Paola , Boulay Clotilde , De Bellescize Julitta , Kéo‐Kosal Pascale , Boutry‐Kryza Nadia , Edery Patrick , Sanlaville Damien , Szepetowski Pierre
Published: June 2012

Purpose:  The continuous spike and waves during slow‐wave sleep syndrome (CSWSS) and the Landau‐Kleffner (LKS) syndrome are two rare epileptic encephalopathies sharing common clinical features including seizures and regression. Both CSWSS and LKS can be associated with the electroencephalography pattern of electrical status epilepticus during slow‐wave sleep and are part of a clinical continuum that at its benign end also includes rolandic epilepsy (RE) with centrotemporal spikes. The CSWSS and LKS patients can also have behavioral manifestations that overlap the spectrum of autism disorders (ASD). An impairment of brain development and/or maturation with complex interplay between genetic predisposition and nongenetic factors has been suspected. A role for autoimmunity has been proposed but the pathophysiology of CSWSS and of LKS remains uncharacterized.

Methods:  In recent years, the participation of rare genomic alterations in the susceptibility to epileptic and autistic disorders has been demonstrated. The involvement of copy number variations (CNVs) in 61 CSWSS and LKS patients was questioned using comparative genomic hybridization assays coupled with validation by quantitative polymerase chain reaction (PCR).

Key Findings:  Whereas the patients showed highly heterogeneous in genomic architecture, several potentially pathogenic alterations were detected. A large number of these corresponded to genomic regions or genes (ATP13A4, CDH9, CDH13, CNTNAP2, CTNNA3, DIAPH3, GRIN2A, MDGA2, SHANK3) that have been either associated with ASD for most of them, or involved in speech or language impairment, or in RE. Particularly, CNVs encoding cell adhesion proteins (cadherins, protocadherins, contactins, catenins) were detected with high frequency (≈20% of the patients) and significant enrichment (cell adhesion: p = 0.027; cell adhesion molecule binding: p = 9.27 × 10−7).

Significance:  Overall our data bring the first insights into the possible molecular pathophysiology of CSWSS and LKS. The overrepresentation of cell adhesion genes and the strong overlap with the genetic, genomic and molecular ASD networks, provide an exciting and unifying view on the clinical links among CSWSS, LKS, and ASD.
A novel EGR2 mutation within a family with a mild demyelinating form of Charcot‐Marie‐Tooth disease
Authors: Shiga Kensuke , Noto Yuichi , Mizuta Ikuko , Hashiguchi Akihiro , Takashima Hiroshi , Nakagawa Masanori
Published: June 2012

Mutations of the early growth response 2 (EGR2) gene have been reported in a variety of severe demyelinating neuropathies such as autosomal recessive congenital hypomyelinating neuropathy, autosomal dominant child‐onset Dejerine‐Sottas neuropathy, and autosomal dominant adult‐onset Charcot‐Marie‐Tooth disease (CMT). Here, we report on a heterozygous mutation in EGR2 (c.1160C>A), which results in threonine at position 387 being changed to asparagine, in a family with a mild demyelinating form of adult‐onset CMT. Of note, both the proband and her asymptomatic son exhibited neither pes cavus nor champagne‐bottle leg atrophy, suggesting that the heterozygous T387N mutation may result in a relatively mild phenotype of demyelinating CMT.
Suppression of neurokinin‐1 receptor in trigeminal ganglia attenuates central sensitization following inflammation
Authors: Takeda Mamoru , Takahashi Masayuki , Matsumoto Shigeji
Published: June 2012

This study examined whether local application of a neurokinin‐1 (NK1) receptor antagonist into the trigeminal ganglia (TRGs) modulates hyperexcitability of trigeminal spinal nucleus caudalis (SpVc) wide‐dynamic range (WDR) neuron activity innervating both the temporomandibular joint (TMJ) region and facial skin following TMJ inflammation. Extracellular single unit recording combined with multibarrel electrodes was used. TMJ inflammation was induced by the injection of complete Freund's adjuvant (CFA). WDR neurons responding to electrical stimuli of the TMJ region and facial skin were recorded from the SpVc in anesthetized rats. The spontaneous and mechanical stimulation‐induced discharge frequencies of WDR neurons were significantly larger in inflamed rats than in control rats. The spontaneous WDR activities were current‐dependently decreased by local iontophoretic application of an NK1 receptor antagonist into the TRGs after 1 and 2 days of inflammation. The firing frequency of WDR neurons and threshold evoked by mechanical stimulation of facial skin returned to control levels by application of the NK1 receptor antagonist into TRGs after 1 day, but not 2 days, of inflammation. These results suggest that in the early stages of inflammation suppression of the NK1 receptor mechanism in TRGs may prevent central sensitization of SpVc nociceptive neurons.
BAG3 mutations: another cause of giant axonal neuropathy
Authors: Jaffer Fatima , Murphy Sinéad M. , Scoto Mariacristina , Healy Estelle , Rossor Alexander M. , Brandner Sebastian , Phadke Rahul , Selcen Duygu , Jungbluth Heinz , Muntoni Francesco , Reilly Mary M.
Published: June 2012

Mutations in Bcl‐2 associated athanogene‐3 (BAG3) are a rare cause of myofibrillar myopathy, characterised by rapidly progressive proximal and axial myopathy, cardiomyopathy and respiratory compromise. Neuropathy has been documented neurophysiologically in previously reported cases of BAG3‐associated myofibrillar myopathy and in some cases giant axons were observed on nerve biopsies; however, neuropathy was not thought to be a dominant feature of the disease. In the context of inherited neuropathy, giant axons are typically associated with autosomal recessive giant axonal neuropathy caused by gigaxonin mutations but have also been reported in association with NEFL‐ and SH3TC2‐associated Charcot‐Marie‐Tooth disease. Here, we describe four patients with heterozygous BAG3 mutations with clinical evidence of a sensorimotor neuropathy, with predominantly axonal features on neurophysiology. Three patients presented with a significant neuropathy. Muscle magnetic resonance imaging (MRI) in one patient revealed mild to moderate atrophy without prominent selectivity. Examination of sural nerve biopsies in two patients demonstrated giant axons. This report confirms the association of giant axonal neuropathy with BAG3‐associated myofibrillar myopathy, and highlights that neuropathy may be a significant feature.
Analyzing Drivers of Regional Carbon Dioxide Emissions for China
Authors: Feng Kuishuang , Siu Yim Ling , Guan Dabo , Hubacek Klaus
Published: June 2012

China faces the challenge of balancing unprecedented economic growth and environmental sustainability. Rather than a homogenous country that can be analyzed at the national level, China is a vast country with significant regional differences in physical geography, regional economy, demographics, industry structure, and household consumption patterns. There are pronounced differences between the much‐developed Eastern‐Coastal economic zone and the less developed Central and Western economic zones in China. Such variations lead to large regional discrepancies in carbon dioxide (CO2) emissions. Using the 28 regional input‐output tables of China for 2002 and 2007 and structural decomposition analysis (SDA), we analyze how changes in population, technology, economic structure, urbanization, and household consumption patterns drive regional CO2 emissions.

The results show a significant gap between the three economic zones in terms of CO2 emission intensity, as the Eastern‐Coastal zone possesses more advanced production technologies compared to the Central and Western zones. The most polluting sectors and largest companies are state‐owned enterprises and thus are potentially able to speed up knowledge transfer between companies and regions. The “greening” of the more developed areas is not only a result of superior technology, but also of externalizing production and pollution to the poorer regions in China. The results also show that urbanization and associated income and lifestyle changes were important driving forces for the growth of CO2 emissions in most regions in China. Therefore, focusing on technology and efficiency alone is not sufficient to curb regional CO2 emissions.
Implant and Long‐Term Evaluation of Atrial Signal Amplification in a Single‐Lead ICD
Authors: STAZI FILIPPO , MAMPIERI MASSIMO , CARDINALE MARIO , LAUDADIO M. TERESA , GARGARO ALESSIO , DEL GIUDICE GIOVANNI BATTISTA
Published: June 2012

Background: In patients without clinical indications for pacing the use of a single‐lead implantable cardioverter defibrillator (ICD) implementing atrial sensing capability with proper signal amplification management may represent a useful therapeutic option, combining the positive features of both single and dual‐chamber devices. The aim of the study was to evaluate the atrial signal amplification and its long‐term stability in a single‐lead ICD system adding atrial sensing to a standard single‐chamber ICD.

Methods: P‐wave amplitudes were collected and compared at implant both with a conventional external device (“unfiltered” P wave) and telemetrically with the implanted ICD (“filtered” P wave). Filtered/unfiltered P‐wave ratio (amplification factor, AmF) was evaluated at implant and during follow‐up.

Results: In 43 enrolled patients (38 men, age 64 ± 16 years), the mean filtered P wave at implant was significantly higher than the unfiltered P wave (3.85 ± 0.81 mV vs 2.0 ± 1.49 mV; P < 10−11), with a mean AmF value of 2.77 ± 1.62. In seven patients with atrial fibrillation at implant, the AmF was higher (4.62 ± 1.94) than in patients in sinus rhythm (2.41 ± 1.30; P < 0.001). A significant linear correlation was found between the inverse of P wave and the AmF (R = 0.82, P < 0.00001). In 25 patients followed for 384 ± 244 days, atrial undersensing was never documented and AmF did not change from implant (3.19 ± 1.82; P = 0.24), also in different body position and breathing conditions.

Conclusions: The single‐lead ICD system evaluated reliably amplified P‐wave amplitudes by a factor of about three, maintaining this performance during the observed follow‐up. (PACE 2012; 35:1119–1125)
Effect of light intensity, prey density, and ontogeny on foraging success and prey selection of larval yellow perch (Perca flavescens)
Authors: Martin Benjamin T. , Wahl David H. , Czesny Sergiusz J.
Published: June 2012

Light intensity has been shown to influence the foraging success of larval fish. However, the effect of light intensity on larval foraging is likely variable and influenced by both the density and characteristics of planktonic prey. In this study we examined the influence of light intensity of 0.1, 2.0, and 60 μmol·s−1·m−2 Photosynthetically Active Radiation (PAR) on foraging of yellow perch (Perca flavescens) larvae at two prey densities. We fed them with a mixture of zooplankton taxa common to lakes inhabited by yellow perch. In addition to light intensity and prey density, the effect of larval yellow perch size was examined by using fish ranging from 9 to 15 mm. The results of our study indicated that yellow perch larvae are well adapted to feed at a wide range of light intensities, as there was no difference in foraging success at investigated light intensities. Increasing prey density from 25 to 150 (zooplankton·l−1) significantly improved the foraging success of larval yellow perch. However, the influence of prey density on foraging success was dependent on fish length. Improved foraging success at increased prey densities occurred only for individuals with a total length >10 mm. Overall, prey selection by fish larvae was influenced by light intensity, prey density, and fish length. However, the factors that influenced selection for specific prey types differed. Our study, combined with evidence from other field and laboratory work, highlight the need for a better understanding of the influence of prey density on foraging throughout ontogeny.
Genetic groups in the common plant species Castanopsis chinensis and their associations with topographic habitats
Authors: Wang Zheng‐Feng , Lian Ju‐Yu , Huang Guo‐Min , Ye Wan‐Hui , Cao Hong‐Lin , Wang Zhang‐Ming
Published: June 2012

In general, even within a local area, many common plant species are found in different types of environment. We propose that if the association of a common plant species with different types of environment is investigated, by analysing all individuals in a given population as a single entity, the results might be misleading or incomplete owing to intraspecific variation. To test this hypothesis, we used molecular markers to classify mature Castanopsis chinensis individuals with a diameter at breast height ≥ 40 cm into different genetic groups and analysed the associations of these groups with topographic features and habitats within a 20‐ha Dinghushan forest plot, South China. Our results indicated that the different groups had different topographical associations, and that the spatial distributions and genetic structures of individuals varied among the groups. Therefore, if significant genetic structure exists in the population of a common species within a community, to understand the relationship between the spatial distributions of individuals in the population and the environment, it is necessary to classify the individuals into genetic groups and analyse the data for these groups, rather than for a combined group of all individuals.
Immigration to the UK from High‐Fertility Countries: Intergenerational Adaptation and Fertility Convergence
Authors: Dubuc Sylvie
Published: June 2012

The fertility of immigrants' children increasingly shapes the ethnic diversity of the population in Western Europe. However, few data are available on the fertility patterns of immigrants and their offspring. This article provides new fertility estimates of immigrants and immigrants' children by ethnic group in the United Kingdom that may provide better‐informed fertility assumptions for future population projection models. The impact of migration‐specific tempo effects on the period TFR of immigrants is analyzed. Among the results, intergenerational fertility transitions strongly contribute both to fertility convergence between ethnic groups and to fertility “assimilation” or “intergenerational adaptation” to the UK mainstream childbearing behavior. Ethnic fertility convergence, particularly marked for populations originating from high‐fertility countries, reflects in part decreasing fertility in sending countries and in part intergenerational adaptation to the UK mainstream. Higher educational enrollment of the daughters of immigrants may partly explain their relatively lower fertility.
Bone morphogenetic protein 4 (BMP‐4) and BMP‐7 induce vascular endothelial growth factor expression in bovine granulosa cells
Authors: SHIMIZU Takashi , MAGATA Fumie , ABE Yasuyuki , MIYAMOTO Akio
Published: June 2012

Bone morphogenetic protein‐4 (BMP‐4) and BMP‐7, theca cell‐derived growth factors, directly affect the granulosa cell function. The aim of this study was to examine the involvement of BMP‐4 or BMP‐7 in vascular endothelial growth factor (VEGF) expression in bovine granulosa cells. Granulosa cells were collected from small follicles (4–6 mm) and seeded at a density of 2–5 × 105 cells per well in Dulbecco's modified Eagle's medium (DMEM)/F12 medium with BMP‐4 or BMP‐7. The expression of VEGF messenger RNA and protein was the maximum when 1.0 ng/mL of BMP‐4 was added to the culture medium. On the other hand, 10 ng/mL of BMP‐7 significantly increased the expression of the VEGF gene and protein. In addition, BMP‐4 stimulated the expression of Smad1 and Smad5 genes in granulosa cells, whereas BMP‐7 stimulated the expression of Smad5 gene. These results suggested that BMP‐4 and BMP‐7 may be associated with VEGF expression via several specific Smads in bovine granulosa cells: BMP‐4 via Smad1/Smad5 and BMP‐7 via Smad5. In conclusion, theca cell‐derived BMP‐4 and BMP‐7 might contribute to follicular vasculature and development by inducing VEGF expression in granulosa cells.
UK health visitors' role in identifying and intervening with infants at risk of developing obesity
Authors: Redsell Sarah A. , Swift Judy A. , Nathan Dilip , Siriwardena A. Niroshan , Atkinson Philippa , Glazebrook Cris
Published: June 2012

Childhood obesity is associated with a number of modifiable risk factors that can be identified during infancy or earlier. In the UK, health visitors advise parents about infant feeding, but little is known about their role in obesity prevention. The aim of this study was to investigate the beliefs and current practices of UK health visitors in relation to recognising and intervening with infants at risk of developing obesity. Thirty members of the health visiting team were interviewed. The interviews were audio‐recorded and transcribed verbatim. Thematic analysis was applied using an interpretative, inductive approach. Health visitors were aware of some of the modifiable risk factors for childhood obesity such as infant feeding practices. They felt they had a role in advising parents about diet but did not formally identify and/or intervene with larger infants. Infant overweight was considered a sensitive issue that was difficult to raise with parents. They believed some parents preferred larger infants and were unaware that their feeding practices might be contributing to obesity risk. A need for training and guidance was identified together with strategies to overcome system barriers. Health visitors do not currently target parents of infants at risk of obesity largely because they do not perceive they have appropriate guidance and skills to enable them to do so. There is an urgent need for tools and training to enable all health care professionals to recognise and manage infants at risk of developing obesity without creating a sense of blame.
Power resources of older people in Iran
Authors: Ravanipour Maryam , Salehi Shayesteh , Taleghani Fariba , Abedi Heidar Ali , Ishaghi Sayed Reza , Schuurmans Marieke J. , de Jong Anneke
Published: June 2012

Background.  Maximising the client’s power resources facilitates their ability to cope with chronic illness. Nurses must be well informed about power resources and feelings of empowerment among older people.

Aim.  This article reports on a study exploring power resources in daily life from the perspective of older people in Iran.

Design.  A qualitative content analysis study was conducted. The participants were selected from older community dwellers in Iran using in‐depth, semi‐structured interviews to understand their experiences with power resources.

Results.  Power in older people in Iran is represented by four dimensions: spiritual, intellectual, social and physical. Each power dimension can be divided into intrinsic and extrinsic modes.

Conclusion.  By maximising older people’s power in intellectual, social and especially in spiritual resources, the effect of the loss of physical power, with its deteriorative or depressogenic effect on older people’s sense of power and well‐being can be compensated for. It is recommended that nurses should plan their interventions to enhance older people’s power, especially their spiritual power.

Implications for practice.  Different models of empowering older people should be explored in Iranian nursing care delivery.
Early post‐operative incontinence following transurethral resection of the prostate: prevalence and patient experiences
Authors: Rita Willener , Elisabeth Spichiger
Published: June 2012

Benign prostatic hyperplasia affects many men over 70 years of age. One of the most effective treatments is transurethral resection of the prostate using either diathermy current through a fine metal cutting loop or holmium fibre. Even after successful surgery, however, patients can suffer from temporary incontinence. Results of a pilot study found that nurses underestimated this problem and were not aware of incontinence in their patients. The aims of this study were to assess prevalence of early post‐operative incontinence, to explore patients' experiences with it, and to determine whether they received adequate information from nurses about how to deal with incontinence at home. To assess prevalence, symptoms and their interference with daily life, 94 men were interviewed using the International Consultation of Incontinence Questionnaire Short Form. To explore experiences, six men were interviewed using an interview guide with open‐ended questions. The findings showed that 35% of the men experienced early post‐operative incontinence within 2 weeks after discharge from hospital. The majority (84%) declared that incontinence interfered with their daily lives. This study reveals that nurses have an important role in educating patients about coping with temporary incontinence following prostate surgery.
Origin and Metamorphism of Corundum‐Rich Metabauxites at Mt. Ismail in the Southern Menderes Massif, SW Turkey
Authors: AYDOĞAN M Selman , MOAZZEN Mohssen
Published: June 2012

The corundum‐rich metabauxites, found at the northwest limb of an NE–SW‐trending isoclinal recumbent fold at Mt. Ismail, are enclosed in thick‐bedded platform‐type marbles of Late Cretaceous age, surrounding the polymetamorphic core series in the southern part of the Menderes Massif (SW Turkey). The metabauxite horizons observed as typically boudine‐like structure, extend laterally over c. 3 km and are 1 to 5 m thick. These rocks have dominant mineral assemblages of corundum (∼50 modal %), chloritoid (∼30 modal %), white mica (margarite, muscovite), diaspore, Fe–Ti‐Oxides (ilmenite, ilmenohematite, rutile), and goethite, limonite, pyrite, tourmaline (uvite, schorl) as minor phases. Chemical analyses of whole rock samples and the mineral assemblage indicate that coexisting minerals of metabauxites are highly aluminous. A number of minerals (e.g. chloritoid and margarite) display a large compositional variation reflecting the initial chemical inhomogenetiy of the karstbauxites. The field observations, trace‐element accumulation coefficients, concentration of elements such as Cr, Zr, Ga and Ni and low amounts of immobile elements all suggest that the studied corundum‐rich metabauxites can be classified as karstbauxites, and are more likely to be a product of weathering of intermediate igneous or argillaceous parental rocks, similar to the karstic Tauric bauxites in the Central Taurides (Seydi şehir region) and probably are similar in age (Cenomanian–Turonian). In respect of tectono‐metamorphic evolution, the studied corundum‐rich metabauxites were regionally metamorphosed at ∼5–6 kbar pressure and 500–600°C as a consequence of the Barrovian metamorphism referred to as the ‘Main Menderes Metamorphism’ related to the ophiolitic obduction onto the Menderes platform from the Izmir–Ankara Suture during the Middle Eocene.
U–Pb Zircon Age Constraining the Source and Provenance of Gem‐Bearing Late Cenozoic Detrital Deposits, Mamfe Basin, SW Cameroon
Authors: KANOUO Nguo Sylvestre , ZAW Khin , YONGUE Rose Fouateu , SUTHERLAND Frederick Lin , MEFFRE Sebastien , NJONFANG Emmanuel , MA Changqian , TCHOUATCHA Milan Stafford
Published: June 2012

Zircons and other heavy minerals (corundum, rutile, ilmenite, magnetite, sillimanite) are identified in the Nsanaragati gem corundum placer deposit, in the western part of the Mamfe sedimentary basin, SW Cameroon. These alluvial minerals have different morphological characteristics and zircons, in particular, vary mostly in colour and shape. They are reddish, brownish, yellowish, pink or colourless. These minerals form rounded and sub‐rounded alluvial grains, prismatic, pyramidal or dipyramidal crystals. Reddish zircons retain their original crystallographic shape. Trace element and U–Pb isotopic geochemical analyses of these reddish zircons, using the LA‐ICP‐MS method give significant Hf (4576–6334 ppm), Th (46–1565 ppm) and U (66–687 ppm) contents, with Th/U ratio ranging from 0.6 to 3.0. The206Pb/238U corrected mean age gave 12.39 ± 0.55 Ma, which characterizes an Upper Cenozoic (Serravallian) magmatic event. The zircons are probably sourced from a magmatic field in the South eastern boundary of the Cross River Formation. The Cameroon Volcanic Line of basaltic and alkaline lavas and intrusions which lie east of the Mamfe Basin mostly range in age from 37 Ma to <1 Ma. The zircons may also relate to the Mount Bambouto plateau lavas which lie northeast of the Mamfe sedimentary basin and have an eruptive age range of 21–14 Ma. The oldest Nsanaragati reddish zircon ages overlap within error with the end stages of the Bambouto eruptions. This eruptive or a related episode provides a potential source for megacrystic reddish zircons within the Nsanagarati placer deposit.
How Plant Lysin Motif Receptors Get Activated: Lessons Learned from Structural Biology
Authors: Willmann Roland , Nürnberger Thorsten
Published: June 2012

A plant immune receptor is selectively activated by larger chitin fragments that trigger receptor dimerization.
AAV-Directed Persistent Expression of a Gene Encoding Anti-Nicotine Antibody for Smoking Cessation
Authors: Hicks Martin J. , Rosenberg Jonathan B. , De Bishnu P. , Pagovich Odelya E. , Young Colin N. , Qiu Jian-ping , Kaminsky Stephen M. , Hackett Neil R. , Worgall Stefan , Janda Kim D. , Davisson Robin L. , Crystal Ronald G.
Published: June 2012

Gene therapy with an anti-nicotine monoclonal antibody limits nicotine access to the brain in mice and may be a potential therapy for cigarette addiction.
MBX-500, a Hybrid Antibiotic with
In Vitro
and
In Vivo
Efficacy against Toxigenic Clostridium difficile
Authors: Butler Michelle M. , Shinabarger Dean L. , Citron Diane M. , Kelly Ciarán P. , Dvoskin Sofya , Wright George E. , Feng Hanping , Tzipori Saul , Bowlin Terry L.
Published: June 2012

Clostridium difficile
infection (CDI) causes moderate to severe disease, resulting in diarrhea and pseudomembranous colitis. CDI is difficult to treat due to production of inflammation-inducing toxins, resistance development, and high probability of recurrence. Only two antibiotics are approved for the treatment of CDI, and the pipeline for therapeutic agents contains few new drugs. MBX-500 is a hybrid antibacterial, composed of an anilinouracil DNA polymerase inhibitor linked to a fluoroquinolone DNA gyrase/topoisomerase inhibitor, with potential as a new therapeutic for CDI treatment. Since MBX-500 inhibits three bacterial targets, it has been previously shown to be minimally susceptible to resistance development. In the present study, the
in vitro
and
in vivo
efficacies of MBX-500 were explored against the Gram-positive anaerobe,
C. difficile
. MBX-500 displayed potency across nearly 50 isolates, including those of the fluoroquinolone-resistant, toxin-overproducing NAP1/027 ribotype, performing as well as comparator antibiotics vancomycin and metronidazole. Furthermore, MBX-500 was a narrow-spectrum agent, displaying poor activity against many other gut anaerobes. MBX-500 was active in acute and recurrent infections in a toxigenic hamster model of CDI, exhibiting full protection against acute infections and prevention of recurrence in 70% of the animals. Hamsters treated with MBX-500 displayed significantly greater weight gain than did those treated with vancomycin. Finally, MBX-500 was efficacious in a murine model of CDI, again demonstrating a fully protective effect and permitting near-normal weight gain in the treated animals. These selective anti-CDI features support the further development of MBX 500 for the treatment of CDI.
In Vitro Studies of Tobramycin, an Aminoglycoside Antibiotic
Authors: Dienstag Jules , Neu Harold C.
Published: June 2012

Tobramycin is an aminoglycoside antibiotic which has excellent antibacterial activity against
Pseudomonas, Staphylococcus aureus
, and many members of the
Enterobacteriaceae
. Most strains of
Serratia, Providence, Streptococcus
, and
Diplococcus pneumoniae
were resistant to concentrations of tobramycin which could be achieved in man. Tobramycin was effective against certain
Pseudomonas
strains resistant to gentamicin. The growth medium used to determine the inhibitory level of tobramycin had a significant effect upon the minimal inhibitory concentration. Calcium and magnesium ions inhibited the bactericidal effect of tobramycin. Tobramycin and carbenicillin acted in a synergistic manner. Ethylenediaminetetraacetic acid did not act in a synergistic manner with tobramycin. Broth-dilution susceptibility tests and disc-diffusion tests in agar (10-μg discs) showed excellent correlation except with
Proteus
strains.
Automated Method for Determination of Penicillins, Cephalosporins, and Penicillinases
Authors: Lindström E. Börje , Nordström Kurt
Published: June 2012

The microiodometric assay of Novick for penicillinase was adapted to the Technicon Autoanalyzer system. With this automated method, it is possible to analyze almost 60 samples per hr. Two different procedures are described: in the first, the samples were incubated with substrate in the machine under standardized conditions; in the second, samples were incubated outside the Autoanalyzer and assayed at intervals for penicilloic acid. As little as 5 μ
m
penicilloic acid could easily be detected in a sample of 0.4 ml. The reproducibility was very good. The hydrolysis of penicillin in a suspension of nongrowing bacteria as well as in a growing culture could also be followed. The automated method has been used both for kinetic studies and in screening for activity in eluates from column chromatography experiments.
Relation of β-Lactamase Activity and Cellular Location to Resistance of
Enterobacter
to Penicillins and Cephalosporins
Authors: Neu Harold C. , Winshell Elaine B.
Published: June 2012

The
Enterobacter
species
E. aerogenes, E. cloacae
, and
E. hafnia
were examined for resistance to penicillin and cephalosporin derivatives. All were resistant to benzyl penicillin, ampicillin, 6 [
d
(−)α-amino-
p
-hydroxyphenylacetamido] penicillanic acid, cephaloridine, cephalothin, and cephalexin. A significant number were sensitive to carbenicillin and 6 [
d
(−)α-carboxy-3-thienylacetamido] penicillanic acid. No differences among the three species were noted. The β-lactamase activity was cell-bound, and was not released by osmotic shock, toluene treatment, or diphenylamine treatment. It was rarely released into the growth medium. The β-lactamase activity was primarily directed against cephalosporin derivatives. Synthesis of β-lactamase was chromosomally mediated. Resistance to ampicillin seemed to be partly related to entry of the molecule into the bacteria since exposure to ethylenediaminetetraacetate lowered the minimal inhibitory concentration.
Biosynthesis of Novobiocin by
Streptomyces niveus
Authors: Kominek L. A.
Published: June 2012

Streptomyces niveus
in a chemically defined medium requires the inclusion of Krebs cycle acids for good growth. These acids are used in preference to glucose, and this results in diauxic growth. Studies with washed cells, cell-free extracts, and mutants of
S. niveus
were performed to determine the mode of synthesis of the individual ring systems of novobiocin and their linkage. A pathway for novobiocin synthesis is proposed on the basis of these experiments.
Effect of Antiviral Agents in Equine Abortion Virus-Infected Hamsters
Authors: Lieberman Melvin , Pascale Andrea , Schafer Thomas W. , Came Paul E.
Published: June 2012

Equine abortion virus, a member of the herpesvirus group, produces a lethal infection in hamsters. With this system, the protective effect of certain inhibitors of deoxyribonucleic acid viruses, inducers of interferon and exogenous interferon, was evaluated. Of the various agents studied, 9-β-
d
-arabinofuranosyladenine markedly suppressed mortality, and 5-iodo-2′-deoxyuridine, distamycin A, and
N
-ethylisatin β-thiosemicarbazone were inactive. Of the inducers tested, statolon, ultraviolet-irradiated Newcastle disease virus, and polyriboinosinic:polyribocytidylic acid (poly I:C) were protective, and endotoxin, polyacrylic acid, and polymethacrylic acid did not protect. Administration of exogenous interferon did not afford protection. Statolon and ultraviolet-irradiated Newcastle disease virus induced circulating interferon in hamsters, whereas poly I:C, endotoxin, and polyacrylic acid did not produce interferon. Because of the severity of the disease produced in hamsters by equine abortion virus, lack of protective activity by an agent in this system should not preclude possible efficacy against other members of the herpesvirus group.
In Vitro Antimicrobial Susceptibility of Anaerobic Bacteria Isolated from Clinical Specimens
Authors: Martin William J. , Gardner Mildred , Washington John A.
Published: June 2012

The minimal inhibitory concentrations of 601 clinical isolates of anaerobic bacteria to 10 different antimicrobial agents were determined by an agar-dilution technique. Nearly all strains were resistant to kanamycin and gentamicin, although moderate activity to both drugs was noted with
Fusobacterium
sp., anaerobic cocci, some strains of
Bacteroides melaninogenicus
, and nonsporeforming gram-positive bacilli. Chloramphenicol at 12.5 μg/ml inhibited all but three of the strains tested. Tetracycline at 6.25 μg/ml had high activity against all groups tested, with the exception that only 39% of strains of
Bacteroides fragilis
were inhibited at this concentration. Excluding certain species of
Bacteroides
, the majority of anaerobes were inhibited by penicillin at 3.1 μg/ml or less and by cephalothin at 12.5 μg/ml or less. Lincomycin at 6.2 μg/ml or less was active against nearly all strains. Erythromycin at a concentration of 3.1 μg/ml was active against
B. fragilis
; however, erythromycin was less active against the other groups. Most of the minimal inhibitory concentrations of lincomycin exceeded those of clindamycin by fourfold. Rifampin inhibited virtually all strains at 3.1 μg/ml.
Neutropenia Associated with Cephapirin Therapy
Authors: Levison Matthew E. , Bran Jose L. , Jepson Joanne H. , Kaye Donald
Published: June 2012

A case of neutropenia associated with cephapirin therapy is described. After discontinuation of cephapirin therapy, the neutrophil count returned to normal. Bone marrow examination revealed a marked reduction of polymorphonuclear leukocytes beyond the metamyelocyte stage and eosinophilia.
Antimicrobial Properties of Natural Phenols and Related Compounds: Obtusastyrene and Dihydro-Obtusastyrene
Authors: King A. D. , Bayne H. G. , Jurd L. , Case C.
Published: June 2012

Factors influencing the antimicrobial properties of obtusastyrene and dihydro-obtusastyrene were studied. Both of these compounds were soluble in acetone, alcohol, and olive oil. In water, they were soluble at concentrations of 34 and 53 μg/ml, respectively. The minimal inhibitory concentrations against gram-positive bacteria and yeast were below 100 μg/ml. The compounds were not effective against gram-negative bacteria at 200 μg/ml or lower concentrations. With initial populations of cells greater than 10
6
/ml, the concentrations of these compounds required to prevent growth were greater than with lower cell populations. Changing the
p
H of the growth medium did not decrease the effectiveness of these two compounds in the
p
H range of 3 through 8. Both obtusastyrene and dihydro-obtusastyrene were rapidly bactericidal to
Staphylococcus aureus
and
Bacillus cereus
at 25 μg/ml.
Inhibitory Effect of Heparin on Gentamicin Concentrations in Blood
Authors: Regamey Claude , Schaberg Dennis , Kirby William M. M.
Published: June 2012

In monitoring gentamicin concentrations in the blood of patients with renal insufficiency, the assayed antibiotic concentration was found to be lower when the sample was drawn as heparinized plasma rather than as serum. This lowering of gentamicin concentrations by heparin was studied further by adding increasing doses of heparin and various amounts of gentamicin to human serum. With a range of 2 to 100 units of heparin per ml, gentamicin concentrations in the serum were lowered by 9 to 14%; with higher heparin concentrations, an even greater and increasing inhibition was noticed, reaching 56% for 1,000 units/ml. This inhibitory effect of heparin on gentamicin was reversible by dilution, indicating that it was not due to degradation or to formation of an inactive chemical complex. Underestimation by the laboratory of gentamicin concentrations in blood is likely to be greatest with capillary tubes, with which the concentration of heparin is especially high. With clinical heparinization, the amount of active heparin in the blood does not exceed 10 units/ml and is for the most part under 3 units/ml; thus, therapeutically significant inhibition of the antibiotic is unlikely in patients receiving anticoagulation.
Screening, Fermentation, Isolation, and Characterization of Trypanomycin, a New Antibiotic
Authors: Fleck W. , Strauss D. , Schönfeld C. , Jungstand W. , Seeber C. , Prauser H.
Published: June 2012

A
Streptomyces
strain which is similar to
S. diastatochromogenes
(Krainsky) Waksman et Henrici 1948 sensu Hütter (1967) was found to produce a new antibiotic designated trypanomycin. The red-pigment antibiotic, which has novel trypanocidal activity in vitro and in vivo, was isolated from a C-, N-, and iron-containing culture of the strain IMET JA 10081/9 by extraction with organic solvents, transfer into the aqueous phase, reextraction with organic solvents at
p
H 6.8, precipitation by hydrocarbons, and purification by chromatographic methods. Trypanomycin has indicator properties. The main constituents of the antibiotic mixture are readily soluble in water and are very stable in distilled water at room temperature (28 C) for 24 hr. The composition of the base of trypanomycin A
2
(melting point, 175 to 183 C) corresponds to the empirical formula C
41–42
H
52-56
NO
21-22
. The absorption spectra in the ultraviolet and visible regions are very similar to those of the 4,5,8-trioxyanthrachinones. Trypanomycin has strong antiprotozoal activity, e.g., against trypanosomes. The natural substance additionally inhibits the growth of gram-positive bacteria, stable as well as unstable L-forms of gram-negative bacteria, mycoplasmas, yeast protoplasts, and tumor cells in vitro. The LD
50
of trypanomycin in mice was 60 mg/kg when administered intravenously and 31 mg/kg on intraperitoneal administration. If the antibiotic was added to cultures of animal or human cells in vitro, mitotic inhibition and chromosomal aberrations resulted. Trypanomycin differs in its biological activities and chromatographic behavior from other anthracyclines, e.g., cinerubine A and B, daunomycin, adriamycin, nogalamycin, rutilantin, pyrromycin, cyclamycin, and ryemycin.
The Elusive Permeability Barriers and Binding Sites for Proflavine in
Escherichia coli
Authors: Gravelle M. Joan , Mehta B. M. , Kushner D. J.
Published: June 2012

Cells of proflavine-sensitive and -resistant
Escherichia coli
strains were altered in different ways, and the proflavine binding of the changed material was studied. Spheroplasts prepared from sensitive and resistant cells bound similar amounts of proflavine at saturation, whether or not they were osmotically protected by 10% sucrose. Intact cells bound approximately the same amounts of proflavine as spheroplasts. On addition of glucose, osmotically protected resistant but not sensitive spheroplasts released proflavine; unprotected spheroplasts did not release bound proflavine. Thus, osmotically protected membranes are not required for proflavine binding (a passive process) but are required for proflavine release (an active process). The presence of sucrose reduced proflavine binding by resistant cells. Adding glucose to cells in 20% sucrose did not cause a release of residual proflavine, though glucose caused a release of proflavine from cells suspended in 0 or 10% sucrose. On treatment of heated cells or ruptured spheroplasts with nucleases and Pronase, practically all nucleic acids were removed. Proflavine-binding ability of such preparations fell by only 30 to 50%. Washing heated cells with ethanol did not reduce their proflavine-binding ability. There appear to be important binding sites in cells aside from nucleic acids.
Triple Crossover Study on Absorption and Excretion of Ampicillin, Talampicillin, and Amoxycillin
Authors: Verbist L.
Published: June 2012

Talampicillin and amoxycillin were shown to be absorbed twice as well as ampicillin in a triple crossover experiment.
Photoinactivation of Venezuelan Equine Encephalitis Virus Mediated by Tetracyclines
Authors: Esparza Jose , PiÑa Carmen I. , Novo Ernesto
Published: June 2012

Demethylchlortetracycline and, to a lesser extent, chlortetracycline were found to mediate the in vitro photoinactivation of Venezuelan equine encephalitis virus.
Nalidixic Acid Inhibition of Post-Ultraviolet Recovery in
Escherichia coli
K-12: Requirement for
recBC
Function
Authors: Purdy Michael A. , Yielding K. Lemone
Published: June 2012

Various repair-deficient mutants of
Escherichia coli
K-12 were tested for the impairment of post-ultraviolet survival by nalidixic acid. These studies have shown that the target of this nalidixic acid effect is dictated by the
recB
and
recC
genes and may be due to the binding of nalidixic acid to exonuclease V. Furthermore, this effect cannot be correlated with either recombination proficiency or excision repair alone.
Specific Inactivation of Herpes Simplex Virus by Silver Nitrate at Low Concentrations and Biological Activities of the Inactivated Virus
Authors: Shimizu Fumio , Shimizu Yoshinobu , Kumagai Katsuo
Published: June 2012

The infectivities of herpes simplex virus types 1 and 2 were inactivated by silver nitrate at concentrations of 30 μM or less, which did not affect at all the infectivities of hemagglutinating virus of Japan, vesicular stomatitis virus, poliovirus, vaccinia virus, and adenovirus. The inactivated virus retained the capability of adsorbing to the cell, with an adsorption kinetics quite similar to that of intact virus, and of inducing the concanavalin A agglutinability in the infected cells, whereas it lost completely the capability of producing viral antigens and other cytopathic changes.
Susceptibility of
Prototheca
Species to Antifungal Agents
Authors: Segal Ester , Padhye Arvind A. , Ajello Libero
Published: June 2012

Twenty isolates of
Prototheca filamenta, Prototheca moriformis, Prototheca stagnora, Prototheca wickerhamii
, and
Prototheca zopfii
were tested for in vitro susceptibility to five commonly used antifungal agents: amphotericin B, 5-fluorocytosine, griseofulvin, miconazole, and nystatin. The results revealed resistance to griseofulvin of all the
Prototheca
isolates tested and an inhibitory effect on
P. filamenta
by high 5-fluorocytosine concentrations (minimal inhibitory concentration [MIC] = 12.5 to 100 μg/ml; minimal fungicidal or algacidal concentration [MFC/MAC] = 50 to 100 μg/ml).
P. filamenta
isolates were also susceptible to miconazole (MIC = 0.1 to 0.5 μg/ml, MFC/MAC = 0.5 to 1 μg/ml); isolates of the other
Prototheca
species varied in regard to miconazole activity from susceptible to resistant (MIC = 1 − >100 μg/ml, MFC/MAC = 5 − >100 μg/ml). The
Prototheca
isolates revealed an in vitro susceptibility to the polyene antifungal agents, amphotericin B, and nystatin (MIC = 0.09 to 3.12 μg/ml and 0.19 to 12.5 μg/ml, respectively; MFC/MAC = 0.19 to 25 μg/ml and 0.75 to 25 μg/ml, respectively).
Indirect Method for Assessing the Penetration of Beta-Lactamase-Nonsusceptible Penicillins and Cephalosporins in
Escherichia coli
Strains
Authors: Richmond M. H. , Clark D. C. , Wotton Sandra
Published: June 2012

Escherichia coli
UB1005 and two mutants of this strain (DC2 and DC3) have been used to assess indirectly the relative ability of various β-lactam antibiotics to penetrate the outer layers of
E. coli
. Benzylpenicillin, ampicillin, methicillin, cloxacillin, cephaloridine, cephalothin, and cephalexin have been examined. The results confirm those obtained with other methods and show that, among the compounds studied here, cephalosporins seem to penetrate more readily than penicillins.