bluuebunny/crossref_metadata_2025 huggingface dataset:
Tool use, communicative gesture and cerebral asymmetries in the modern human brain
Authors: Frey Scott H
Published: February 2008

Determining the brain adaptations that underlie complex tool-use skills is an important component in understanding the physiological bases of human material culture. It is argued here that the ways in which humans skilfully use tools and other manipulable artefacts is possible owing to adaptations that integrate sensory–motor and cognitive processes. Data from brain-injured patients and functional neuroimaging studies suggest that the left cerebral hemisphere, particularly the left parietal cortex, of modern humans is specialized for this purpose. This brain area integrates dynamically representations that are computed in a distributed network of regions, several of which are also left-lateralized. Depending on the nature of the task, these may include conceptual knowledge about objects and their functions, the actor's goals and intentions, and interpretations of task demands. The result is the formation of a praxis representation that is appropriate for the prevailing task context. Recent evidence is presented that this network is organized similarly in the right- and left-handed individuals, and participates in the representation of both familiar tool-use skills and communicative gestures. This shared brain mechanism may reflect common origins of the human specializations for complex tool use and language.
Wild agency: nested intentionalities in cognitive neuroscience and archaeology
Authors: Jordan J. Scott
Published: February 2008

The present paper addresses the tensions between internalist and radical-interactionist approaches to cognitive neuroscience, and the conflicting conclusions these positions lead to as regards the issue of whether archaeological artefacts constitute ‘results’ or ‘components’ of cognition. Wild systems theory (WST) and the notion of wild agency are presented as a potential resolution. Specifically, WST conceptualizes organisms (i.e. wild agents) as open, multi-scale self-sustaining systems. It is thus able to address the causal properties of wild systems in a manner that is consistent with radical-interactionist concerns regarding multi-scale contingent interactions. Furthermore, by conceptualizing wild agents as self-sustaining embodiments of the persistent, multi-scale contexts that afforded their emergence and in which they sustain themselves, WST is able to address the semantic properties of wild agents in a way that acknowledges the internalist concerns regarding meaningful (i.e. semantic) internal states (i.e.
causal content
). In conclusion, WST agrees with radical interactionism and asserts that archaeological artefacts constitute components of cognition. In addition, given its ability to resolve tensions between the internalist and the radical interactionist approaches to cognition, WST is presented as potentially integrative for cognitive science in general.
Self‐regulating hyperthermia induced using thermosensitive ferromagnetic material with a low Curie temperature
Authors: Saito Hajime , Mitobe Kazutaka , Ito Aki , Sugawara Yu , Maruyama Kiyotomi , Minamiya Yoshihiro , Motoyama Satoru , Yoshimura Noboru , Ogawa Jun–ichi
Published: February 2008

Hyperthermia has been used for many years to treat a variety of malignant tumors. The Curie temperature (Tc) is a transition point at which magnetic materials lose their magnetic properties, causing a cessation of current and thus heat production. The Tc enables automatic temperature control throughout a tumor as a result of the self‐regulating nature of the thermosensitive material. We have developed a method of magnetically‐induced hyperthermia using thermosensitive ferromagnetic particles (FMPs) with low Tc (43°C), enough to mediate automatic temperature control. B16 melanoma cells were subcutaneously injected into the backs of C57BL/6 mice, after which tumors were allowed to grow to 5 mm in diameter. FMPs were then injected into the tumors, and the mice were divided into three groups: group I (no hyperthermia, control); group II (one hyperthermia treatment); and group III (hyperthermia twice a week for 4 weeks). When exposed to a magnetic field, the FMPs showed a sharp rise in heat production, reaching the Tc in tissue within 7 min, after which the tissue temperature stabilized at approximately the Tc. In groups I and II, all mice died within 30–45 days. In group III, however, 6 of 10 mice remained alive 120 days after beginning treatment. Our findings suggest that repeated treatment with magnetically‐induced self‐regulating hyperthermia, mediated by FMPs with a low Tc, is an effective means of suppressing melanoma growth. A key advantage of this hyperthermia system is that it is minimally invasive, requiring only a single injection for repeated treatments with automatic temperature control. (Cancer Sci 2008; 99: 805–809)
Secondary mutations in the kinase domain of the KIT gene are predominant in imatinib‐resistant gastrointestinal stromal tumor
Authors: Nishida Toshirou , Kanda Tatsuo , Nishitani Akiko , Takahashi Tsuyoshi , Nakajima Kiyokazu , Ishikawa Takashi , Hirota Seiichi
Published: February 2008

Although imatinib showed high activity for advanced gastrointestinal stromal tumor (GIST) and improved the prognosis of GIST patients, resistance to the drug appears with prolonged use. Mechanisms of acquired resistance are still under investigation. In the present study, we carried out histologic and genetic analysis of 45 secondary resistant lesions obtained from 25 Japanese GIST patients treated with imatinib. All resistant lesions showed viable tumor cells expressing KIT protein, whereas imatinib‐sensitive lesions did not. All pre‐imatinib samples have KIT mutations either in exon 9 (n = 3) or exon 11 (n = 22), identified in the KIT gene of corresponding resistant tumors. In addition to primary mutations, 33 out of 45 tumors (73%) showed secondary KIT mutations in the kinase domain of the KIT gene. Secondary mutations are missense mutations and are mostly located in the kinase domains of the same allele to the primary mutations (cis‐position). Resistant lesions showed monoclonal development of tumor cells. Taken together, additional cis‐positioned mutations in the kinase domains are a major cause of secondary resistance to imatinib in Japanese GIST patients. (Cancer Sci 2008; 99: 799–804)
Monitoring during sedation given by non‐anaesthetic doctors
Authors: Fanning Ruth M.
Published: February 2008

Conscious sedation is routinely performed by non‐anaesthetic doctors. Although guidelines exist to help promote patient safety, it is not clear how stringently these are adhered to. We circulated a questionnaire to non‐anaesthetic doctors in training to assess sedation practices. A response rate of 79% (111/140) was achieved. Results showed that 70% of respondents used data recording sheets and/or had protocols for recovery and discharge. In all, 88% of procedures were performed in the presence of an assistant; 82% of respondents used pulse oximetry; 80% used non‐invasive blood pressure monitoring; 53% used ECG monitoring; and none used capnography. Of respondents, 29% were Advanced Cardiac Life Support (ACLS) certified; and 22% reported an adverse event. Two respondents experienced adverse events that required the assistance of an anaesthetist. The practice of sedation is not without risk, and doctors involved in the practice should be aware of, and adhere to, appropriate guidelines.
Into adulthood: a follow‐up study of 718 young people who were placed in out‐of‐home care during their teens
Authors: Vinnerljung Bo , Sallnäs Marie
Published: February 2008

In this study, national register data were used to analyse long‐term outcomes at age 25 for around 700 Swedish young people placed in out‐of‐home care during their teens. The sample consisted of 70% of all 13‐ to 16‐year olds who entered out‐of‐home care in 1991. Results revealed a dividing line between young people placed in care for behavioural problems and those placed for other reasons. Young woman and men from the first group had – in comparison with peers who did not enter care – very high rates of premature death, serious involvement in crime, hospitalizations for mental‐health problems, teenage parenthood, self‐support problems and low educational attainment. Young people who were placed for other reasons had better outcomes, but still considerably worse than non‐care peers. Young women tended to do better than young men, regardless of reasons for placement. Very high rates of hospitalizations for mental health problems were found among young people placed for behavioural problems. Breakdown of placement was found to be a robust indicator of poor long‐term prognosis.
Effects of resource availability and social parasite invasion on field colonies of Bombus terrestris
Authors: CARVELL CLAIRE , ROTHERY PETER , PYWELL RICHARD F. , HEARD MATTHEW S.
Published: February 2008

Abstract 1. The survival, growth and fecundity of bumblebee colonies are affected by the availability of food resources and presence of natural enemies. Social parasites (cuckoo bumblebees and other bumblebees) can invade colonies and reduce or halt successful reproduction; however, little is known about the frequency of invasion or what environmental factors determine their success in the field.

2. We used 48 experimental colonies of the bumblebee Bombus terrestris, and manipulated both resource availability at the landscape scale and date of colony founding, to explore invasion rates of social parasites and their effect on the performance of host colonies.

3. Proximity to abundant forage resources (fields of flowering oilseed rape) and early colony founding significantly increased the probability of parasite invasion and thus offset the potential positive effects of these factors on bumblebee colony performance.

4. The study concludes that optimal colony location may be among intermediate levels of resources and supports schemes designed to increase the heterogeneity of forage resources for bumblebees across agricultural landscapes.
The presence of conifer resin decreases the use of the immune system in wood ants
Authors: CASTELLA GRÉGOIRE , CHAPUISAT MICHEL , MORET YANNICK , CHRISTE PHILIPPE
Published: February 2008

Abstract 1. Wood ants (Formica paralugubris) incorporate large amounts of solidified conifer resin into their nest, which reduces the density of many bacteria and fungi and protects the ants against some detrimental micro‐organisms. By inducing an environment unfavourable to pathogens, the presence of resin may allow workers to reduce the use of their immune system.

2. The present study tested the hypothesis that the presence of resin decreases the immune activity of wood ants. Specifically, three components of the humoral immune defences of workers kept in resin‐rich and resin‐free experimental nests (antibacterial, lytic, and prophenoloxidase activities) were compared.

3. The presence of resin was associated with reduced bacterial and fungal densities in nest material and with a small decrease in worker antibacterial and lytic activities. The prophenoloxidase activity was very low in all workers and was not affected by the presence of resin.

4. These results suggest that collective medication with resin reduces pathogen pressure, which in turn decreases the use of the inducible part of the immune system. More generally, the use of plant secondary compounds might be an efficient and economical way to fight pathogens.
Genetic variability in Irish populations of the invasive zebra mussel,Dreissena polymorpha: discordant estimates of population differentiation from allozymes and microsatellites
Authors: GOSLING ELIZABETH , ASTANEI IULIAN , WAS ANNA
Published: February 2008

1. The recent arrival and explosive spread of the zebra mussel,Dreissena polymorpha(Pallas), in Ireland provided a rare opportunity to study the population genetics of an invasive species.

2. Eight polymorphic allozyme loci (ACO‐1, ACO‐2,EST‐D, GPI, IDH‐2, MDH, OPDHandPGM) were used to investigate genetic diversity and population structure in five Irish populations, and the results were compared with those from a previous microsatellite study on the same samples.

3. The mean number of alleles per locus (2.7 ± 0.1) was similar to the mean for the same loci in European populations, suggesting that Irish founder populations were large and/or multiple colonization events took place after foundation. A deficiency of heterozygotes was observed in all populations, but was uneven across loci.

4. Pairwise comparisons, using Fisher’s exact tests andFSTvalues, revealed significant genetic differentiation among populations. The overall multilocusFSTestimate was 0.118 ± 0.045, which contrasted with an estimate of 0.015 ± 0.007 from five microsatellite loci on the same samples in a previous study.

5. Assuming that microsatellites can be used as a neutral baseline, the discordant results from allozymes and microsatellites suggest that selection may be acting on some allozyme loci, specificallyACO‐1, ACO‐2,IDH‐2andMDH,which contributed most to the significant differentiation between samples.
Effects of flooding on avian top‐predators and their invertebrate prey in a monsoonal Taiwan stream
Authors: CHIU MING‐CHIH , KUO MEI‐HWA , SUN YUAN‐HSUN , HONG SHIAO‐YU , KUO HIH‐CHUAN
Published: February 2008

1. The effects of flooding on top predators are poorly understood globally, but particularly in monsoonal streams. We therefore attempted to assess how inter‐annual and intra‐annual variations in flood magnitude affected an obligate riverine predator, the brown dipper (Cinclus pallasii), and its invertebrate prey, in the mountain Tachia River, Taiwan. Major flooding in one of the study years (2005) allowed an insight into the effects of abnormally large flows.

2. The abundance and biomass of insects, and the abundance of dippers, decreased steadily from 2003 to 2005 as flood magnitude grew, but then increased in 2006 when more typical discharge returned. Dipper abundance, insect abundance and insect biomass were all strongly positively inter‐related, but negatively related to discharge. Insect biomass, rather than abundance, was more useful in predicting brown dipper abundance.

3. Aquatic insect composition fluctuated among sampling years, revealed by non‐metric multidimensional scaling, and these fluctuations were also related to discharge. In turn, dipper abundance and the mean body size of aquatic insects declined with the shift in insect composition as flow increased.

4. These data illustrate how discharge fluctuations can have pronounced effects on top predators in streams, mediated in this case by fluctuating prey abundance. While contributions from bird movement, breeding performance and mortality were not clearly differentiated, our data reveal how dippers have strategies to accommodate varying discharge in river systems. We suggest that the effects of floods on dippers should be taken into account when using this group as indicators of river quality.
E3 ubiquitin ligase E6AP‐mediated TSC2 turnover in the presence and absence of HPV16 E6
Authors: Zheng Li , Ding Huirong , Lu Zheming , Li Yong , Pan Yaqi , Ning Tao , Ke Yang
Published: February 2008

We previously found that HPV16 E6 causes the degradation of the tumor suppressor protein TSC2, resulting in the phosphorylation of S6 kinase and S6 even in the absence of insulin. In the present study, we investigated the role of E6‐associated protein (E6AP) in HPV16 E6‐induced TSC2 degradation. Our results demonstrated that TSC2 was targeted for degradation in the presence or absence of HPV16 E6. Over‐expression of E6AP enhanced the degradation of TSC2 by HPV16 E6, while expression of a dominant negative E6AP (C833A) inhibited the E6‐induced degradation. Additionally, by using shRNAs to block E6AP expression in HPV16 positive and negative cells, we found a significantly prolonged TSC2 half‐life. An in vivo ubiquitination assay was done to reveal that E6AP promoted the ubiquitination of TSC2 independent of HPV16 E6. We further found that TSC2 bound E6AP in the presence as well as in the absence of HPV16 E6. The binding regions on E6AP and TSC2 have been identified as amino acid (aa) 260–316, aa 428–500 and aa 1–175, aa 1251–1807, respectively. Taken together, degradation of TSC2 is mediated by E6AP ubiquitin ligase.
Combination of Clk family kinase and SRp75 modulates alternative splicing of Adenovirus E1A
Authors: Yomoda Jun‐ichiro , Muraki Michiko , Kataoka Naoyuki , Hosoya Takamitsu , Suzuki Masaaki , Hagiwara Masatoshi , Kimura Hiroshi
Published: February 2008

SR proteins are non‐snRNP splicing factors harbouring a domain rich in Arg‐Ser repeats, which are extensively phosphorylated by several kinases. We performed a comparative study of different SR kinases, including SRPK, Clk, PRP4 and DYRK, and found that only Clks efficiently altered 5′ splice site selection of Adenovirus E1A. The phosphorylation state of SR proteins was examined using a phospho‐SR specific antibody mAb1H4 and a 75 kDa protein was most evidently hyperphosphorylated by Clks. Administration of TG003, a specific inhibitor for the Clk family members, specifically and rapidly induced dephosphorylation of 75 kDa SR protein. Imaging with mRFP‐SRp75 in living cells revealed that its nuclear distribution was rapidly altered upon inhibition of the Clk activity by TG003. Co‐transfection experiments demonstrated that HA‐tagged SRp75 was hyperphosphorylated by Clk family members, but not by other SR kinases. These results indicate that Clks specifically hyperphosphorylate SRp75. Furthermore, SRp75 over‐expression promoted the selection of 12S 5′ splice site in E1A pre‐mRNA, which is stimulated by co‐expression of Clks. These results suggest that the specific combination of SR protein and SR kinase plays a distinct role in alternative splicing through dynamic balance of phosphorylation.
Cop9 signalosome subunit 8 (CSN8) is essential for Drosophila development
Authors: Oren‐Giladi Pazit , Krieger Ofra , Edgar Bruce A. , Chamovitz Daniel A. , Segal Daniel
Published: February 2008

The COP9 signalosome (CSN) is a multisubunit regulator highly conserved in evolution. We show here that CSN subunit 8 (CSN8) is essential for Drosophila development. CSN8 is maternally contributed and present throughout development. Null mutants generated in this study are larval lethal, showing phenotypes associated with mutations in either CSN4 (molting defects) or CSN5 (melanotic tumors). Analysis of mitotic and germ‐line csn8null clones revealed the requirement of CSN8 for multiple developmental processes. The germ‐line clones arrested at mid‐oogenesis, while the mitotic clones led to deformed adult eyes or wings. CSN8 is present exclusively as part of the CSN holo‐complex, and lack of CSN8 in the mutants leads to CSN instability. Consistent with this, Cullin deneddylation is impaired in the csn8null mutants.
Modulation of M2‐type pyruvate kinase activity by the cytoplasmic PML tumor suppressor protein
Authors: Shimada Nobukazu , Shinagawa Toshie , Ishii Shunsuke
Published: February 2008

The promyelocytic leukemia (PML) tumor suppressor protein accumulates in PML nuclear bodies (PML‐NBs), and can induce growth arrest, cellular senescence and apoptosis. PML has also been localized in the cytoplasm, although its function in this localization remains elusive. A general property of primary cancers is their high glycolytic rate which results from increased glucose consumption. However, the mechanism by which cancer cells up‐regulate glycolysis is not well understood. Here, we have shown that cytoplasmic PML (cPML) directly interacts with M2‐type pyruvate kinase (PKM2), a key regulator of carbon fate. PKM2 determines the proportion of carbons derived from glucose that are used for glycolytic energy production. Over‐expression of PML‐2KA mutant in the cytoplasm, which was generated by mutagenesis of the nuclear localization signals of PML, in MCF‐7 breast cancer cells suppressed PKM2 activity and the accumulation of lactate. PKM2 exists in either an active tetrameric form which has high affinity for its substrate phosphoenolpyruvate (PEP) or a less active dimeric form which has low affinity for its substrate. Over‐expression of PML‐2KA suppressed the activity of the tetrameric form of PKM2, but not the dimeric form. Our findings suggest that cPML plays a role in tumor metabolism through its interaction with PKM2.
Interactions of elevated carbon dioxide and temperature with aphid feeding on transgenic oilseed rape: Are Bacillus thuringiensis (Bt) plants more susceptible to nontarget herbivores in future climate?
Authors: HIMANEN SARI J. , NISSINEN ANNE , DONG WEN‐XIA , NERG ANNE‐MARJA , STEWART C. NEAL , POPPY GUY M. , HOLOPAINEN JARMO K.
Published: February 2008

Climate change factors such as elevated carbon dioxide (CO2) and temperature typically affect carbon (C) and nitrogen (N) dynamics of crop plants and the performance of insect herbivores. Insect‐resistant transgenic plants invest some nutrients to the production of specific toxic proteins [i.e. endotoxins from Bacillus thuringiensis (Bt)], which could alter the C–N balance of these plants, especially under changed abiotic conditions. Aphids are nonsusceptible to Lepidoptera‐targeted Bt Cry1Ac toxin and they typically show response to abiotic conditions, and here we sought to discover whether they might perform differently on compositionally changed Bt oilseed rape. Bt oilseed rape had increased N content in the leaves coupled with reduced total C compared with its nontransgenic counterpart, but in general the C : N responses of both plant types to elevated CO2 and temperature were similar. Elevated CO2 decreased N content and increased C : N ratio of both plant types. Elevated temperature increased C and N contents, total chlorophyll and carotenoid concentrations under ambient CO2, but decreased these under elevated CO2. In addition, soluble sugars were increased and starch decreased by elevated temperature under ambient but not under elevated CO2, whereas photosynthesis was decreased in plants grown under elevated temperature in both CO2 levels. Myzus persicae, a generalist aphid species, responded directly to elevated temperature with reduced developmental time and decreased adult and progeny weights, whereas the development of the Brassica specialist Brevicoryne brassicae was less affected. Feeding by M. persicae resulted in an increase in the N content of oilseed rape leaves under ambient CO2, indicating the potential of herbivore feeding itself to cause allocation changes. The aphids performed equally well on both plant types despite the differences between C–N ratios of Bt and non‐Bt oilseed rape, revealing the absence of plant composition‐related effects on these pests under elevated CO2, elevated temperature or combined elevated CO2 and temperature conditions.
Forest transition in Vietnam and its environmental impacts
Authors: MEYFROIDT PATRICK , LAMBIN ERIC F.
Published: February 2008

This study assesses the presence of a forest transition – that is, a shift from net deforestation to net reforestation – in Vietnam during the 1990s, and describes its key attributes relevant for global environmental change issues. Using Fuzzy Kappa and other indicators, we compared forest cover estimates and spatial patterns from global and national land cover maps from the early and late 1990s, and compiled other available statistics for years before and after that period. This showed that a forest transition indeed occurred in Vietnam: the forest cover dropped to 25–31% of the country area in 1991–1993, and then increased to 32–37% in 1999–2001. The reforestation occurred at a higher rate than deforestation in the previous decades, and was due in similar proportions, to natural forest regeneration and to planted forests. The carbon stock in forests followed a similar transition, decreasing to 903 (770–1307) Tg C in 1991–1993, and then increasing to 1374 (1058–1744) Tg C in 2005. However, forest density declined during the same period, with an increasing proportion of young and degraded forests. The effects on habitats measured with landscape pattern indices were contrasted: in several regions, the reforestation decreased forest fragmentation, while in others, clearing of old‐growth forests continued and/or forest fragmentation increased. This shows that a transition in forest area is not sufficient to rehabilitate the different ecosystem functions and services of forests. Other forest transitions exist in Tropical Asia and in Latin America. Knowledge about the causes, pattern and environmental impacts of the forest transition in Vietnam is therefore relevant to understand possible emerging regional trends that would have implications for global environmental change.
Multiple anthropogenic changes cause biodiversity loss through plant invasion
Authors: Van Der WAL RENÉ , TRUSCOTT ANNE‐MARIE , PEARCE IMOGEN S. K. , COLE LISA , HARRIS MIKE P. , WANLESS SARAH
Published: February 2008

Non‐native invasive plants are a widely acknowledged threat to global biodiversity. However, our understanding of the mechanisms underlying plant invasion, and the relative importance of multiple rather than single drivers, remains poor. Here, we provide a case study using time‐series data to reconstruct patterns of change, and field experiments to test for causality. We show how, over a 50‐year period, a series of unrelated human‐induced changes created highly favorable conditions for the non‐native tree mallow (Lavatera arborea) to turn invasive, causing loss of native vegetation and seabird breeding habitat. The combination of three drivers: human‐introduced disease, climate warming and a fisheries‐mediated increase in seabird populations, removed major constraints on plant population growth, (i.e. grazer control, climatic control, germination opportunity and nutrient limitation). Collectively, these changes created optimal conditions for the rapid expansion of tree mallow. The resulting dramatic impact on both the native vegetation and breeding seabirds, notably puffins (Fratercula arctica), exemplifies how non‐native invasive plant species can transform terrestrial ecosystems. While climate change is regarded as a key factor behind plant invasion, we highlight that multiple rather than single factors may be critical to biodiversity loss.
Influence of simulated snow cover on the cold tolerance and freezing injury of yellow‐cedar seedlings
Authors: SCHABERG PAUL G. , HENNON PAUL E. , D'AMORE DAVID V. , HAWLEY GARY J.
Published: February 2008

It has been hypothesized that yellow‐cedar [Chamaecyparis nootkatensis (D. Don) Spach] decline may result from root freezing injury following climate change‐induced reductions in protective snow cover. To test this hypothesis, we measured the freezing tolerance and injury expression of yellow‐cedar seedlings in three treatments that differed in the insulative protection they provided to soils during winter and spring: (1) full exposure to ambient temperatures (exposed treatment), (2) continuous protection from ambient temperatures via addition of perlite over pots (full protection), and (3) perlite protection only during winter and exposure to ambient temperatures during spring (partial protection). Foliage from all treatments was cold tolerant enough to prevent foliar freezing injury throughout the study period. However, on all sample dates, roots of seedlings from all treatments were only tolerant to about −5 °C – a level considerably warmer than the reported maximum cold tolerance for the species and well above the soil temperature recorded in the exposed treatment. As a result of this limited root cold tolerance, visibly uninjured roots of seedlings from the exposed treatment had significantly higher relative electrolyte leakage (REL) throughout the winter and early spring than seedlings in soil protection treatments. Seedlings from the exposed treatment also had significantly higher foliar REL values and greater visual foliar injury than seedlings from the other treatments starting in early spring. For both roots and foliage, REL measurements consistently detected tissue damage before visual injury was evident. Patterns of injury from both REL and visual injury assessments showed the same pattern: damage began with freezing injury to roots and subsequently became evident as foliar browning after spring temperatures increased. All seedlings in the exposed treatment eventually had 100% fine root damage and died. This progression of initial root damage followed by foliar browning and mortality after the onset of warming conditions is consistent with reports of yellow‐cedar decline symptom development in the field.
Blockade of epithelial sodium channels improves sperm motility in asthenospermia patients
Authors: Kong Xiang‐Bin , Ma Hua‐Gang , Li Hong‐Gang , Xiong Cheng‐Liang
Published: February 2008

Epithelial Na+ channels (ENaCs) are ion channels that play important roles in physiology as well as pathophysiology. Inhibiting ENaCs using amiloride and its derivatives has been suggested in treatment of cardivascular disease and hypertension. By immunoblotting, we demonstrated the presence of ENaC‐α protein in the flagellar midpiece of both rat and human sperm. Immunohistochemistry analyses in rat testis localized ENaC‐α expressed in the Leydig cell, Sertoli cell, Ap spermatogonium, spermatocyte, spermatid and residual body. Importantly, using computer‐assisted sperm motility analysis, we first observed that EIPA [5‐(N‐ethyl‐N‐isopropyl)‐amiloride hydrochloride] inhibition of ENaCs, possibly including ENaC‐α and ENaC‐δ, significantly improved the sperm motility in healthy donors by 14.23% (mean ± SEM, 68.75 ± 9.76% vs. 78.53 ± 6.20%, p < 0.001) and in asthenospermia patients by 115.89% from 9.50 ± 6.11% to 20.51 ± 12.13% (mean ± SEM, p < 0.001). The improved sperm motility by EIPA has important clinical implications in the treatment of asthenospermia and certainly warrants further investigation.
Assessment of erectile dysfunction in diabetic patients
Authors: Hamdan Farqad B. , Al‐Matubsi Hisham Y.
Published: February 2008

Erectile dysfunction (ED) aetiology is multifactorial, including endocrine, neurological, vascular, systemic disease, local penile disorders, nutrition, psychogenic factors, and drug‐related. This study was performed to compare the relevant comprehensive biochemical parameters as well as the clinical characteristics in diabetic ED and healthy control subjects and to assess the occurrence of penile neuropathy in diabetic patients and thus the relationship between ED and diabetes. A total of 56 patients accepted to undergo assessment for penile vasculature using intracavernosal injection and colour Doppler ultrasonography. Of the 56 diabetic patients, 38 patients were found with normal blood flow and thus they were considered as the diabetic‐ED group, whereas, ED diabetic patients with an arteriogenic component were excluded. These patients with an age range between 17 and 58 years, complaining of ED, with duration of diabetic illness ranging from 2 to 15 years. The Control group comprised of 30 healthy subject aged between 19 and 55 years. Peripheral venous levels of testosterone, prolactin, follicle stimulating hormone (FSH), luteinizing hormone (LH), thyroid stimulating hormone (TSH), malondialdehyde and glycosylated haemoglobin (HbA1c) were obtained in all subjects. Valsalva manoeuvre and neurophysiological tests were also determined. Testosterone, prolactine, FSH, LH, and TSH hormones of the diabetic patients were not significantly different from those of the control group. Diabetic patients with ED have higher HbA1c and oxidative stress levels while the R‐R ratio was significantly decreased. Bulbocavernosus reflex latency was significantly prolonged, whereas its amplitude, the conduction velocity and amplitude of dorsal nerve of penis were significantly reduced in the diabetic patients. We concluded that although ED is a multifactorial disorder, yet, the present study revealed that in ED patients without arteriogenic ED a neurogenic component is present. Furthermore, the complex effect of the Valsalva manoeuvre on cardiovascular function is the basis of its usefulness as a measure of autonomic function. Thus, it can be of value in the diagnosis of ED although these hypotheses require follow‐up in a large study cohort.
Patterns of release of the secondary conidia of Claviceps africana, the sorghum ergot pathogen in Australia
Authors: Ryley M. J. , Chakraborty S.
Published: February 2008

Trials were conducted in southern Queensland, Australia between March and May 2003, 2004 and 2005 to study patterns of hourly and daily release of the secondary conidia of Claviceps africana and their relationships with weather parameters. Conidia were trapped for at least one hour on most (> 90%) days in 2003 and 2004, but only on 55% of days in 2005. Both the highest daily concentration of conidia, and the highest number of hours per day when conidia were trapped, were recorded 1–3 days after rainfall events. Although the pattern of conidial release was different every day, the highest hourly conidial concentrations occurred between 10·00 hours and 17·00 hours on 73% of all days in the three trials. Hours when conidia were trapped were characterized by higher median values of temperature, windspeed and vapour pressure deficit, lower relative humidity, and leaf wetness values of 0%, than hours when no conidia were recorded. The results indicate that fungicides need to be applied to the highly ergot‐susceptible male sterile (A‐) lines of sorghum in hybrid seed production blocks and breeders’ nurseries as soon as possible after rainfall events to minimize ergot severity.
Quantification of ToxB gene expression and formation of appressoria by isolates of Pyrenophora tritici‐repentis differing in pathogenicity
Authors: Amaike S. , Ozga J. A. , Basu U. , Strelkov S. E.
Published: February 2008

Tan spot, caused by the fungus Pyrenophora tritici‐repentis, is an important foliar disease of wheat. The pathogen produces at least three host‐specific toxins, including Ptr ToxB, a 6·6 kDa protein that causes chlorosis in sensitive wheat genotypes and is encoded by the ToxB gene. Using quantitative reverse transcriptase (qRT)‐PCR, transcript levels of ToxB homologues found in virulent (≡ pathogenic) and weakly virulent (≡ weakly pathogenic) race 5 isolates and an avirulent (≡ nonpathogenic) race 4 isolate of the fungus were compared in conidia, mycelia, and in host tissues after inoculation of resistant and susceptible wheat genotypes. Abundance of the ToxB transcript was greatest in the virulent isolate, followed by the weakly virulent and avirulent isolates, and was positively correlated with the development of chlorosis in the susceptible wheat genotype; transcript was detectable in mycelia and conidia of all isolates tested, and levels peaked at 24 h after inoculation of the race 5 isolates onto resistant and susceptible wheat hosts, before disease symptoms developed. Although all isolates could penetrate host epidermal cells to varying degrees, transcript abundance was positively correlated with the greater and more rapid development of appressoria. Therefore Ptr ToxB may have other roles in the basic pathogenic fitness of the fungus and/or in pre‐penetration processes, suggesting that quantitative variation in the virulence of P. tritici‐repentis is related to the extent of ToxB gene expression.
Silencing RNA‐directed RNA polymerase 2 increases the susceptibility of Nicotiana attenuata to UV in the field and in the glasshouse
Authors: Pandey Shree P. , Baldwin Ian T.
Published: February 2008

RNA‐directed RNA‐polymerases (RdRs) are essential in small interfering RNA (siRNA) biogenesis and appear to be functionally specialized. We examined the consequences of silencing RdR2 in Nicotiana attenuata with a field release, and transcriptional, two‐dimensional proteomic and metabolite analyses. NaRdR2‐silenced plants (irRdR2) had large reductions (46% of wild type) in 22–24‐nt small RNAs (smRNAs), and smaller reductions (35, 23 and 26% of wild type) in the 19–21, 25–27 and 28–30‐nt smRNAs, respectively. When planted into their native habitats in the Great Basin Desert, irRdR2 plants had impaired growth and reproductive output, which were associated with reduced levels of leaf phenolics (rutin and 4′‐chlorogenic acid) and MYB and PAL transcripts, but were unaffected in their herbivore resistance. These phenotypes were confirmed in glasshouse experiments, but only when irRdR2 plants were grown with UV‐B radiation. irRdR2 plants had wild‐type levels of elicited phytohormones and resistance to Manduca sexta attack, but when exposed to UV‐B, had reduced growth, fitness, levels of MYB and PAL transcripts, and phenolics. Proteins related to protection against oxidative and physiological stresses, chromatin remodeling and transcription were also downregulated. Silencing the MYB gene by virus‐induced gene silencing (VIGS) in wild‐type plants reduced levels of PAL transcripts and phenolics, as it did in UV‐exposed irRdR2 plants. Bioinformatic analysis revealed that genes involved in phenylpropanoid biosynthesis contained a large number of smRNA binding motives, suggesting that these genes are targets of smRNAs. We conclude that although NaRdR2 transcripts are upregulated in response to both UV‐B and herbivore elicitation, the responses they regulate have been tailored to provide protection from UV‐B radiation.
Nuclear localization of the mutant protein phosphatase abi1 is required for insensitivity towards ABA responses in Arabidopsis
Authors: Moes Danièle , Himmelbach Axel , Korte Arthur , Haberer Georg , Grill Erwin
Published: February 2008

ABI1, a protein phosphatase 2C, is a key component of ABA signal transduction in Arabidopsis that regulates numerous ABA responses, such as stomatal closure, seed germination and inhibition of vegetative growth. The abi1‐1 mutation, so far the only characterized dominant allele for ABI1, impairs ABA responsitivity in both seeds and vegetative tissues. The site of action of ABI1 is unknown. We show that there is an essential requirement for nuclear localization of abi1 to confer insensitivity towards ABA responses. Transient analyses in protoplasts revealed a strict dependence of wild‐type ABI1 and mutant abi1 on a functional nuclear localization sequence (NLS) for regulating ABA‐dependent gene expression. Arabidopsis lines with ectopic expression of various abi1 forms corroborated the necessity of a functional NLS to control ABA sensitivity. Disruption of the NLS function in abi1 rescued ABA‐controlled gene transcription to wild‐type levels, but also attenuated abi1‐conferred insensitivity towards ABA during seed germination, root growth and stomatal movement. The mutation in the PP2C resulted in a preferential accumulation of the protein in the nucleus. Application of a proteosomal inhibitor led to both a preferential nuclear accumulation of ABI1 and an enhancement of PP2C‐dependent inhibitory action on the ABA response. Thus, abi1‐1 acts as a hypermorphic allele, and ABI1 reprograms sensitivity towards ABA in the nucleus.
Can ecological and evolutionary arguments solve the riddle of the missing marine insects?
Authors: Ruxton Graeme D. , Humphries Stuart
Published: February 2008

We critically appraise the recent literature on the paucity of marine insects and conclude that this near‐absence does demand explanation; but this explanation is unlikely to be found in the suggested problems of depth for insect respiratory systems. We tentatively suggest some areas where further consideration may yield fruitful answers to this long‐standing evolutionary riddle.
Rectal tuberculosis: A rare cause of recurrent rectal suppuration
Authors: Samarasekera D. N. , Nanayakkara P. R.
Published: February 2008

Tuberculosis affecting the rectum is a rare extra‐pulmonary form of the disease that needs recognition, because it requires specific treatment and avoids multiple, unwarranted surgical interventions. The following discussion is centred on a case of rectal tuberculosis, a disease that rarely affects the anorectal region. The condition was diagnosed on histology and was successfully treated medically with complete resolution.
Trends in colorectal day case surgery in NHS Trusts between 1998 and 2005
Authors: Faiz O. D. , Brown T. J. , Colucci G. , Grover M. , Clark S. K.
Published: February 2008

Objective  Day case surgery is safe and offers potential benefits to both patients and healthcare providers. This study aimed to describe national changes in colorectal day case workload between 1998 and 2005.

Methods  Admission data relating to Office of Population Censuses and Surveys Classification of Surgical Operations and Procedures (4th revision) (OPCS‐4) coloproctology operation codes were analysed using the Hospital Episode Statistics (HES) database. Day case rates (DCRs) were calculated as the proportion of elective cases performed on an ambulatory basis.

Results  In total, 3 119 058 colorectal admissions were recorded on the HES database between 1998 and 2005; 1 891 474 (61%) of these were for lower gastrointestinal endoscopies. Emergency cases accounted for 527 665 (17%), elective inpatient cases for 406 368 (13%) and elective day cases for 293 551 (9%) admissions. Throughout the study period the DCRs for five commonly performed elective colorectal procedures were: 0.70 for anal lesion excisions (OPCS‐4 codes: H48.1, H48.2 and H48.3); 0.16 for haemorrhoidectomy (OPCS‐4 code: H51.1); 0.63 for anal fissure procedures (OPCS‐4 codes: H56.2 and H56.4); 0.39 for elective procedures for anal fistula (OPCS‐4 codes: H55.1, H55.2, H55.3 and H55.4); 0.37 for elective pilonidal surgery (OPCS‐4 codes: H59 and H60.2). Two emergency operations, drainage of perianal and pilonidal abscesses (OPCS‐4 codes: H58.2 and H60.3 respectively), were identified as operations potentially amenable to day surgery. Over the seven study years, an annual average of 8559 (±SD 307) admissions were coded to drainage of a perianal abscess and 4676 (±SD 478) admissions to drainage of pilonidal abscess. The average annual bed usage associated with these procedures was 18 831 (±SD 718) and 7623 (±SD 436) bed days respectively.

Conclusions  Colorectal day case surgery is currently under‐exploited in the NHS. By lifting some of the barriers to day case surgery significant resource savings may be possible.
The changing impact of age on colorectal cancer surgery. A trend analysis
Authors: Nascimbeni R. , Di Fabio F. , Di Betta E. , Salerni B.
Published: February 2008

Objective  The aim of the study was to evaluate the changing influence of age on the outcomes of colorectal cancer surgery in a retrospective trend analysis.

Methods  Data on 985 patients undergoing colorectal cancer surgery were collected during 1975–1984 and 1995–2004. Variables and outcomes of patients aged < 65, 65–74, 75–84 and 85+ years were compared with intra‐ and interdecade analyses. Endpoints of the study were postoperative mortality, 5‐year overall and cancer‐related survivals.

Results  The rate of elderly patients undergoing colorectal cancer surgery increased significantly from 1975–1984 to 1995–2004. Distribution of American Society of Anesthesiology score and cancer stage remained unchanged over time. The rate of palliative procedures decreased over time, most significantly in the older age groups. In 1995–2004 the palliation rate was similar across all age groups. The rate of emergency surgery also decreased, but it remained higher in older age groups. Operative mortality rate decreased over time across all age groups, but age‐related differences were still observed in the 1995–2004 series. Cancer‐related survival after curative surgery increased from 58% in 1975–1984 to 64% in 1995–2004 in 75+ years patients, while it increased from 56% to 78% in patients aged 74 years or younger.

Conclusions  Elderly patients with colorectal cancer benefited substantially from healthcare progress during the last 30 years. The reduction of palliative procedures and the decline in operative mortality document the efficacy of not restricting the access to radical surgery for these patients.
Preoperative conditioning with oral carbohydrate loading and oral nutritional supplements can be combined with mechanical bowel preparation prior to elective colorectal resection
Authors: Hendry P. O. , Balfour A. , Potter M. A. , Mander B. J. , Bartolo D. C. C. , Anderson D. N. , Fearon K. C. H.
Published: February 2008

Objective  Preoperative conditioning with oral fluid and carbohydrate (CHO) loading allows the patient to undergo surgery in the fed state and is associated with reduced postoperative insulin resistance. Further benefit may accrue from oral nutritional supplements (ONS) to counteract the fasting associated with mechanical bowel preparation (MBP). In this study we assess the ability to prescribe, dispense and have patients comply with a protocol combining preoperative ONS and CHO/fluid loading during MBP.

Method  One hundred and forty‐seven patients undergoing elective left colonic or rectal resection were recruited to an Enhanced Recovery after Surgery (ERAS) programme. All patients were prescribed MBP (2 sachets Picolax). On the daytime prior to surgery, eligible patients were prescribed 2 × 200 ml of ONS (Fortijuice®, Nutricia) and in the evening 800 ml oral CHO/fluid loading (Preop®, Nutricia,). Patients were prescribed a further 400 ml of oral/CHO/fluid on the morning of surgery 2 h prior to induction of anaesthesia. Protocol compliance was audited prospectively.

Results  One hundred and forty‐seven patients received MBP. Twenty‐three patients were ineligible for oral CHO/fluid loading [diabetes (n = 22), allergy to lemon flavoured drinks (n = 1)]. Fourteen patients did not receive the preoperative CHO drinks due to failure to prescribe (n = 8) or dispense (n = 6). One hundred and ten patients were dispensed the combined ONS and CHO/fluid loading regimen, compliance rates were 83% with ONS, 80% with CHO/fluid loading and 74% with both.

Conclusion  Approximately 74% of patients undergoing MBP can comply with preoperative conditioning with ONS and CHO/fluid loading. Prescription and dispensing requires close attention to detail.
Pneumococcal pneumonia in HIV‐infected patients by antiretroviral therapy periods
Authors: Saindou M , Chidiac C , Miailhes P , Voirin N , Baratin D , Amiri M , Livrozet J‐M , Touraine J‐L , Trepo C , Peyramond D , Vanhems P
Published: February 2008

Objective

To ascertain the relationship between periods of various antiretroviral therapies and the incidence of first community‐acquired pneumococcal pneumonia (CAPP) among HIV‐1 infected patients.

Methods

We analysed 4075 patients enrolled prospectively in the Lyon section of the French Hospital Database on HIV between 1993 and 2004, stratified into three groups. The first group (G1) included patients for whom enrolment and last follow‐up were before the highly active antiretroviral therapy (HAART) period (beginning 1 July 1996); the second group (G2) comprised patients who were enrolled before HAART but had last follow‐up in the HAART period; the third group (G3) included patients for whom both enrolment and last follow‐up took place in the HAART period.

Results

Fifty‐five CAPP episodes were identified. The incidence of CAPP per 1000 patient‐years declined over time, from 10.6 to 1.5 and 2.5 in calendar periods G1, G2 and G3, respectively (P=0.004 for linear trend). Factors associated with a decreased risk of CAPP were lower age, baseline CD4 count ≥200 cells/μL and more recent years of enrolment, when HAART use became extensive (P<0.001). The use of intravenous drugs increased the risk of CAPP (P<0.001).

Conclusions

There has been a significant reduction in the incidence of CAPP in HIV‐1 infected patients since the advent of HAART.