bluuebunny/crossref_metadata_2025 huggingface dataset:
Strong mixture effects among four species in fertilized agricultural grassland led to persistent and consistent transgressive overyielding
Authors: Nyfeler Daniel , Huguenin‐Elie Olivier , Suter Matthias , Frossard Emmanuel , Connolly John , Lüscher Andreas
Published: April 2009

Increasing plant species richness often increases biomass production in nutrient‐poor semi‐natural grasslands. If such positive diversity–productivity effects also apply to nutrient‐rich agricultural grasslands, mixtures could improve resource‐use efficiency in the vast area used for forage production. We therefore quantified the diversity–productivity effects in nutrient‐rich agricultural grasslands using four‐species grass–legume mixtures.

The sown overall density and species proportions ofLolium perenne,Dactylis glomerata,Trifolium pratenseandTrifolium repenswere varied in a 3‐year field experiment to investigate the effects of species richness (1, 2, 4 species) and species proportion (0, 3, 10, 25, 40, 50, 70, 90, 100% sowing proportion) on productivity under a nitrogen fertilization of 50, 150 or 450 kg N ha−1 year−1.

The four‐species mixtures reached up to twice the yield of the average of the four species’ monocultures (overyielding up to 106%), predominantly due to combining grass and legume species. Mixtures were up to 57% more productive than the most productive monoculture (transgressive overyielding). Both these diversity–productivity effects appeared across a broad range of species proportions and persisted at the two lower levels of N fertilization for 3 years.

Mixtures fertilized with 50 kg N ha−1 year−1produced yields comparable to grass monocultures fertilized with 450 kg N ha−1 year−1, if the legume proportion was about 50 to 70%. Diversity–productivity effects were reduced at the highest level of N fertilization, where they virtually disappeared in the third year. Increased N fertilization also accelerated the observed general trend towardsD. glomeratadominated and legume‐poor swards.

Synthesis and applications. Diversity–productivity effects led to consistent transgressive overyielding in intensively managed grasslands, suggesting a highly increased resource‐use efficiency in mixtures. Performance better than monocultures can be achieved with grass–legume mixtures that have a low number of species, across a wide range of species proportions and in nutrient‐rich conditions. Processes such as niche complementarity and positive interspecific interactions leading to diversity effects proved to be highly relevant and widely applicable for intensive forage production. Such diversity–productivity effects could allow reduced inputs of N fertilizer without loss of productivity in different grassland production systems.
Contrasting patterns and mechanisms of spatial turnover for native and exotic freshwater fish in Europe
Authors: Leprieur Fabien , Olden Julian D. , Lek Sovan , Brosse Sébastien
Published: April 2009

Aim  We compare the distribution patterns of native and exotic freshwater fish in Europe, and test whether the same mechanisms (environmental filtering and/or dispersal limitation) govern patterns of decrease in similarity of native and exotic species composition over geographical distance (spatial species turnover).

Locations  Major river basins of Europe.

Methods  Data related to geography, habitat diversity, regional climate and species composition of native and exotic freshwater fish were collated for 26 major European river basins. We explored the degree of nestedness in native and exotic species composition, and quantified compositional similarity between river basins according to the beta‐sim (independent of richness gradient) and Jaccard (dependent of richness gradient) indices of similarity. Multiple regression on distance matrices and variation‐partitioning approaches were used to quantify the relative roles of environmental filtering and dispersal limitation in shaping patterns of decreasing compositional similarity over geographical distance.

Results  Native and exotic species exhibited significant nested patterns of species composition, indicating that differences in fish species composition between river basins are primarily the result of species loss, rather than species replacement. Both native and exotic compositional similarity decreased significantly with increasing geographical distance between river basins. However, gradual changes in species composition with geographical distance were found only for exotic species. In addition, exotic species displayed a higher rate of similarity decay (higher species turnover rate) with geographical distance, compared with native species. Lastly, the majority of explained variation in exotic compositional similarity was uniquely related to geography, whereas native compositional similarity was either uniquely explained by geography or jointly explained by environment and geography.

Main conclusions  Our study suggests that large‐scale patterns of spatial turnover for exotic freshwater fish in Europe are generated by human‐mediated dispersal limitation, whereas patterns of spatial turnover for native fish result from both dispersal limitation relative to historical events (isolation by mountain ranges, glacial history) and environmental filtering.
Effects of habitat history and extinction selectivity on species‐richness patterns of an island land snail fauna
Authors: Chiba Satoshi , Okochi Isamu , Ohbayashi Takashi , Miura Daichi , Mori Hideaki , Kimura Kazuki , Wada Shinichiro
Published: April 2009

Aim Local‐scale diversity patterns are not necessarily regulated by contemporary processes, but may be the result of historical events such as habitat changes and selective extinctions that occurred in the past. We test this hypothesis by examining species‐richness patterns of the land snail fauna on an oceanic island where forest was once destroyed but subsequently recovered.

Location Hahajima Island of the Ogasawara Islands in the western Pacific.

Methods Species richness of land snails was examined in 217 0.25 × 0.25 km squares during 1990–91 and 2005–07. Associations of species richness with elevation, current habitat quality (proportion of habitat composed of indigenous trees and uncultivated areas), number of alien snail species, and proportion of forest loss before 1945 in each area were examined using a randomization test and simultaneous autoregressive (SAR) models. Extinctions in each area and on the entire island were detected by comparing 2005–07 records with 1990–91 records and previously published records from surveys in 1987–91 and 1901–07. The association of species extinction with snail ecotype and the above environmental factors was examined using a spatial generalized linear mixed model (GLMM).

Results The level of habitat loss before 1945 explained the greatest proportion of variation in the geographical patterns of species richness. Current species richness was positively correlated with elevation in the arboreal species, whereas it was negatively correlated with elevation in the ground‐dwelling species. However, no or a positive correlation was found between elevation and richness of the ground‐dwelling species in 1987–91. The change of the association with elevation in the ground‐dwelling species was caused by greater recent extinction at higher elevation, possibly as a result of predation by malacophagous flatworms. In contrast, very minor extinction levels have occurred in arboreal species since 1987–91, and their original patterns have remained unaltered, mainly because flatworms do not climb trees.

Main conclusions The species‐richness patterns of the land snails on Hahajima Island are mosaics shaped by extinction resulting from habitat loss more than 60 years ago, recent selective extinction, and original faunal patterns. The effects of habitat destruction have remained long after habitat recovery. Different factors have operated during different periods and at different time‐scales. These findings suggest that historical processes should be taken into account when considering local‐scale diversity patterns.
Mobile game‐based learning in secondary education: engagement, motivation and learning in a mobile city game
Authors: Huizenga J. , Admiraal W. , Akkerman S. , Dam G. ten
Published: April 2009

Using mobile games in education combines situated and active learning with fun in a potentially excellent manner. The effects of a mobile city game called Frequency 1550, which was developed by The Waag Society to help pupils in their first year of secondary education playfully acquire historical knowledge of medieval Amsterdam, were investigated in terms of pupil engagement in the game, historical knowledge, and motivation for History in general and the topic of the Middle Ages in particular. A quasi‐experimental design was used with 458 pupils from 20 classes from five schools. The pupils in 10 of the classes played the mobile history game whereas the pupils in the other 10 classes received a regular, project‐based lesson series. The results showed those pupils who played the game to be engaged and to gain significantly more knowledge about medieval Amsterdam than those pupils who received regular project‐based instruction. No significant differences were found between the two groups with respect to motivation for History or the Middle Ages. The impact of location‐based technology and game‐based learning on pupil knowledge and motivation are discussed along with suggestions for future research.
The influence of risk factors on the abundance, egg laying habits and impact of Argulus foliaceus in stillwater trout fisheries
Authors: Taylor N G H , Wootten R , Sommerville C
Published: April 2009

Fishery managers perceive the ectoparasitic crustacean, Argulus foliaceus to be a cause of significant economic loss through reduced fish capture rates. This study investigates the influence of previously identified risk factors on the abundance, egg laying habits and impact of this parasite through a longitudinal study of five trout fisheries of varying management intensity. Low water clarity, slow stock turnover and high temperatures showed a significant association with a high abundance of A. foliaceus. High infection levels, low water clarity and low temperature were also associated with reduced rates of fish capture, suggesting abundance of A. foliaceus alone may not affect the catch rates. Depth of egg laying varied in each site throughout the study, increasing in depth as temperature and water clarity increased. Eggs were found to be most abundant in natural fish holding areas and it is hypothesized that the location of egg laying is determined by the habitat usage of host fish.
Vaccination of rainbow trout, Oncorhynchus mykiss (Walbaum), with recombinant and DNA vaccines produced to Flavobacterium psychrophilum heat shock proteins 60 and 70
Authors: Plant K P , LaPatra S E , Cain K D
Published: April 2009

Flavobacterium psychrophilum heat shock proteins (Hsp) 60 and 70 are highly immunogenic and were therefore investigated as potential vaccine candidates. Recombinant Hsps were purified from Escherichia coli and rainbow trout (Oncorhynchus mykiss) were intraperitoneally injected with phosphate buffered saline/Freunds complete adjuvant (FCA), 8 μg of rHsp60/FCA, rHsp70/FCA or a combination of 4 μg each of rHsp60 and rHsp70/FCA. Antibody responses against recombinant Hsp60 and Hsp70 8 weeks post‐immunization were observed, but only fish immunized with rHsp70 exhibited highly elevated antibody levels against F. psychrophilum whole cell lysate. Some cross reactivity occurred, which may have been due to the V5 tag common to both proteins. Protection against F. psychrophilum challenge was not observed in any treatments at 8 weeks post‐immunization. To further investigate any protective effect of these proteins, hsps were polymerase chain reaction amplified and cloned into pVAX1. Rainbow trout were intramuscularly injected with 8 μg of pVAX1hsp60, pVAX1hsp70 or a combination of 4 μg each of pVAX1hsp60 and pVAX1hsp70. Antibody responses at 4 weeks post‐immunization were low and protection was not observed following challenge at 6 or 10 weeks post‐immunization. Although Hsps of F. psychrophilum have been shown to be immunodominant, these antigens do not appear to be good vaccine candidates when delivered alone or in combination.
PCR amplification and sequence analysis of the major capsid protein gene of megalocytiviruses isolated in Taiwan
Authors: Wang C S , Chao S Y , Ku C C , Wen C M , Shih H H
Published: April 2009

Viruses belonging to the genus Megalocytivirus in the family Iridoviridae are one of the major agents causing mass mortalities in marine and freshwater fish in Asian countries. Outbreaks of iridovirus disease have been reported among various fish species in Taiwan. However, the genotypes of these iridoviruses have not yet been determined. In this study, seven megalocytivirus isolates from four fish species: king grouper, Epinephelus lanceolatus (Bloch), barramundi perch, Lates calcarifer (Bloch), silver sea bream, Rhabdosargus sarba (Forsskal), and common ponyfish, Leiognathus equulus (Forsskal), cultured in three different regions of Taiwan were collected. The full open reading frame encoding the viral major capsid protein gene was amplified using PCR. The PCR products of approximately 1581 bp were cloned and the nucleotide sequences were phylogenetically analysed. Results showed that all seven PCR products contained a unique open reading frame with 1362 nucleotides and encoded a structural protein with 453 amino acids. Even though the nucleotide sequences were not identical, these seven megalocytiviruses were classified into one cluster and showed very high homology with red sea bream iridovirus (RSIV) with more than 97% identity. Thus, the seven iridovirus strains isolated from cultured marine fish in Taiwan were closer to the RSIV genotype than the infectious spleen and kidney necrosis virus genotype.
Lack of hepatitis E virus infection in HIV patients with advanced immunodeficiency or idiopathic liver enzyme elevations
Authors: Madejón A. , Vispo E. , Bottecchia M. , Sánchez‐Carrillo M. , García‐Samaniego J. , Soriano V.
Published: April 2009

Summary.  Hepatitis E virus (HEV) is an enterically transmissible RNA agent that causes self‐limited acute hepatitis. Recent reports have highlighted that organ‐transplant recipients may develop chronic hepatitis E and progress to cirrhosis. Similar cases could occur in HIV patients. We have investigated 50 HIV‐infected individuals with CD4 counts <200 cells/mm3 and 43 with cryptogenic hepatitis. None of them showed HEV viremia. Thus, HEV infection does not seem to be prevalent in the HIV population and accordingly universal HEV vaccination is not warranted in these patients.
Phenotypic correlates of Clock gene variation in a wild blue tit population: evidence for a role in seasonal timing of reproduction
Authors: LIEDVOGEL MIRIAM , SZULKIN MARTA , KNOWLES SARAH C. L. , WOOD MATTHEW J. , SHELDON BEN C.
Published: April 2009

The timing of reproduction in birds varies considerably within populations and is often under strong natural selection. Individual timing within years is dependent on a range of environmental factors in addition to having an additive genetic basis. In vertebrates, an increasing amount is known about the molecular basis for variation in biological timing. The Clock gene includes a variable poly‐glutamine (poly‐Q) repeat influencing behaviour and physiology. Recent work in birds, fish and insects has demonstrated associations between Clock genotype and latitude across populations, which match latitudinal variation in breeding time. In this study, we investigated the phenotypic correlates of variation in Clock genotype within a single blue tit Cyanistes caeruleus population over two successive breeding seasons. In females, but not in males, we observed a general trend for birds with fewer poly‐Q repeats to breed earlier in the season. Incubation duration was shorter in both females and males with fewer repeats at the polymorphic Clock locus. Poly‐Q Clock allele‐frequency was homogenously distributed within the study population and did not exhibit any consistent environment‐related variation. We further tested for effects of Clock genotype on reproductive success and survival, and found that females with fewer poly‐Q repeats produced a higher number of fledged offspring. Our results therefore suggest that (i) selection in females, but not in males, for fewer poly‐Q repeats may be operating, (ii) the across–population associations in timing of breeding involving this locus could be linked to variation within populations, and (iii) the Clock gene might be involved in local adaptation to seasonal environments.
The LetA‐RsmYZ‐CsrA regulatory cascade, together with RpoS and PmrA, post‐transcriptionally regulates stationary phase activation of Legionella pneumophila Icm/Dot effectors
Authors: Rasis Michal , Segal Gil
Published: April 2009

Legionella pneumophila utilize the Icm/Dot type‐IV secretion system to translocate effector proteins into host cells. Some of these effectors were shown before to be regulated at the transcriptional level by the PmrAB and CpxRA two‐component systems. In addition, the stationary phase‐related regulators LetA and CsrA, which are both members of the same post‐transcriptional regulatory cascade, were shown to be involved in L. pneumophila virulence. In this report, we identified two small non‐coding RNAs which are part of the LetA‐CsrA regulatory cascade and three effector‐encoding genes which are directly controlled by this regulatory system. We found that the small non‐coding RNAs RsmY and RsmZ, were upregulated by LetA at stationary phase, and relieve the repression of CsrA from its target genes. The three effector‐encoding genes were found to be post‐transcriptionally upregulated at stationary phase and to contain CsrA regulatory elements that were found to be essential for their stationary phase activation. In addition, rsmY and rsmZ were found to be regulated by the RpoS sigma‐factor and the csrA encoding gene was found to be regulated by PmrA. Our results demonstrate that L. pneumophila effectors are regulated at both the transcriptional and the post‐transcriptional levels by a complicated regulatory network.
Organization of the genes encoding the biosynthesis of actagardine and engineering of a variant generation system
Authors: Boakes Steven , Cortés Jesús , Appleyard Antony N. , Rudd Brian A. M. , Dawson Michael J.
Published: April 2009

The biosynthetic pathway of the type B lantibiotic actagardine (formerly gardimycin), produced by Actinoplanes garbadinensis ATCC31049, has been cloned, sequenced and annotated. The gene cluster contains the gene garA that encodes the actagardine prepropeptide, a modification gene garM, involved in the dehydration and cyclization of the prepeptide, several putative transporter and regulatory genes as well as a novel luciferase‐like monooxygenase gene designated garO. Expression of these genes in Streptomyces lividans resulted in the production of ala(0)‐actagardine while deletion of the garA gene from A. garbadinensis generated a strain incapable of producing actagardine. Actagardine production was successfully restored however, by the delivery of the plasmid pAGvarX. This plasmid contains an engineered cassette of the actagardine encoding gene garA and offers an alternative route to generating extensive libraries of actagardine variants. Using this plasmid, an alanine scanning library has been constructed and the mutants analysed. Further modifications include the removal of the novel garO gene from A. garbadinensis. Deletion of this gene resulted in the production of deoxy variants of actagardine, demonstrating that the formation of the sulfoxide group is enzyme catalysed and not a spontaneous chemical modification as previously believed.
The species‐level phylogeny of archostematan beetles—where doMicromalthus debilisandCrowsoniella relictabelong?
Authors: HÖRNSCHEMEYER THOMAS
Published: April 2009

A species‐level phylogenetic analysis comprising 37 of the 45 known extant species of archostematan beetles and a total of 110 morphological characters from adults and larvae is presented. For the first time, characters of the male genitalia are included in a phylogenetic analysis of Archostemata. The dataset is analysed with parsimony as well as with Bayesian algorithms. Analyses with differently arranged datasets, with larval characters included or excluded, and including or excludingMicromalthus debilisandCrowsoniella relictaare conducted. The resulting hypothesis of the species‐level phylogeny of Archostemata confirms Cupedidae and Ommatidae as monophyletic taxa. Within Cupedidae, the South AmericanParacupesand the North AmericanPriacmatogether are the sister group to all remaining Cupedidae. Among the latter, the identification of a clade comprisingRhipsideigma, Cupes capitatusandTenomerga leucophaearendersTenomergapolyphyletic.Ascioplaga scalenacomb. nov. is transferred fromAdinolepis. Characters of the male genitalia support phylogenetic affinities ofMicromalthus debiliswith Ommatidae and ofCrowsoniella relictawith Cupedidae.
Sequence variants in the HLX gene at chromosome 1q41‐1q42 in patients with diaphragmatic hernia
Authors: Slavotinek AM , Moshrefi A , Lopez Jiminez N , Chao R , Mendell A , Shaw GM , Pennacchio LA , Bates MD
Published: April 2009

Congenital diaphragmatic hernia (CDH) is a common birth defect for which few causative genes have been identified. Several candidate regions containing genes necessary for normal diaphragm development have been identified, including a 4–5 Mb deleted region at chromosome 1q41‐1q42 from which the causative gene(s) has/have not been cloned. We selected the HLX gene from this interval as a candidate gene for CDH, as the Hlx homozygous null mouse has been reported to have diaphragmatic defects and the gene was described as being expressed in the murine diaphragm. We re‐sequenced HLX in 119 CDH patients and identified four novel single nucleotide substitutions that predict amino acid changes: p.S12F, p.S18L, p.D173Y and p.A235V. These sequence alterations were all present in patients with isolated CDH, although patients with both isolated CHD and CDH with additional anomalies were studied. The single‐nucleotide substitutions were absent in more than 186 control chromosomes. In‐situ hybridization studies confirmed expression of Hlx in the developing murine diaphragm at the site of the junction of the diaphragm and the liver. Although functional studies to determine if these novel sequence variants altered the inductive activity of Hlx on the α‐smooth muscle actin and SM22α promoters showed no significant differences between the variants and wild‐type Hlx, sequence variants in HLX may still be relevant in the pathogenesis of CDH in combination with additional genetic and environmental factors.
Copy number variation at 1q21.1 results in a spectrum of developmental abnormalities
Authors: Aldinger Kimbery A.
Published: April 2009

Recurrent rearrangements of chromosome 1q21.1 and variable pediatric phenotypes. Mefford H et al.. (2008) N Eng J Med 359: 1685–1699.
Mutations in the tRNA splicing endonuclease complex cause pontocerebellar hypoplasia
Authors: Bailey Kathleen A. , Aldinger Kimbery A.
Published: April 2009

tRNA splicing endoluclease mutations cause pontocerebellar hypoplasia. Budde BS et al.. (2008) Nature Genetics 40: 1113–1118.
Timing of dextral oblique subduction along the eastern margin of the Asian continent in the Late Cretaceous: Evidence from the accretionary complex of the Shimanto Belt in the Kii Peninsula, Southwest Japan
Authors: Tokiwa Tetsuya
Published: April 2009

Paleomagnetic studies and hotspot track analyses show that the Kula Plate was subducted dextrally with respect to the Eurasian Plate from the Coniacian to Campanian. However, geological evidence for dextral subduction of the Kula Plate has not been reported from Southwest Japan. Studies of the Coniacian to lower Campanian Miyama Formation of the Shimanto Belt reveal that the mélange fabrics show a dextral sense of shear both at outcrop and microscopic scales. In addition, thrust systems at map‐scale also show dextral shearing. Restored shear directions in the mélange indicate dextral oblique subduction of an oceanic plate. This indicates that the Kula Plate subducted dextrally along the eastern margin of Asia during the Coniacian to early Campanian. Combinations with other published kinematic and age constraints suggest that Southwest Japan experienced a change from sinistral to dextral and back to sinistral shear between 89–76 Ma. This history is compatible with global‐scale plate reconstructions and places good constraints on the timing of plate boundary interaction with the Cretaceous East Asian margin.
Melt–wall rock interaction in the mantle shown by silicate melt inclusions in peridotite xenoliths from the central Pannonian Basin (western Hungary)
Authors: Szabó Csaba , Hidas Károly , Bali Enikő , Zajacz Zoltán , Kovács István , Yang Kyounghee , Guzmics Tibor , Török Kálmán
Published: April 2009

In this paper we present a detailed textural and geochemical study of two equigranular textured amphibole‐bearing spinel lherzolite xenoliths from Szigliget, Bakony–Balaton Highland Volcanic Field (BBHVF, western Hungary) containing abundant primary silicate melt inclusions (SMIs) in clinopyroxene rims and secondary SMIs in orthopyroxene (and rarely spinel) along healed fractures. The SMIs are dominantly composed of silicate glass and CO2‐rich bubbles. Clinopyroxene and orthopyroxene are zoned in both studied xenoliths, especially with respect to Fe, Mg, Na, and Al contents. Cores of clinopyroxenes in both xenoliths show trace element distribution close to primitive mantle. Rims of clinopyroxenes are enriched in Th, U, light rare earth elements (LREEs) and medium REEs (MREEs). Amphiboles in the Szg08 xenolith exhibit elevated Rb, Ba, Nb, Ta, LREE, and MREE contents. The composition of silicate glass in the SMIs covers a wide range from the basaltic trachyandesite and andesite to phonolitic compositions. The glasses are particularly rich in P2O5. Both primary and secondary SMIs are strongly enriched in incompatible trace elements (mostly U, Th, La, Zr) and display a slight negative Hf anomaly. The development of zoned pyroxenes, as well as the entrapment of primary SMIs in the clinopyroxene rims, happened after partial melting and subsequent crystallization of clinopyroxenes, most probably due to an interaction between hot volatile‐bearing evolved melt and mantle wall‐rocks. This silicate melt filled microfractures in orthopyroxenes (and rarely spinels) resulting in secondary SMIs.
Reconstructing the evolution of fault zone architecture: Field‐based study of the core region of the Atera Fault, Central Japan
Authors: Niwa Masakazu , Mizuochi Yukihiro , Tanase Atsushi
Published: April 2009

In order to reconstruct the architectural evolution of a fault zone with heterogeneous structures, we studied the Atera Fault in Central Japan, and described the detailed mesoscopic and microscopic features of the zone. The fault zone studied consists of a 1.2‐m wide fault core of fault breccia mixed with fragments derived from welded tuff, granite, and mafic volcanic rocks. The 1.2‐m wide fault core is bordered by a western damage zone characterized by a welded tuff fault breccia and an eastern damage zone characterized by a granite cataclasite. A secondary fault core, a 30‐cm wide granite‐derived fault gouge, cross‐cuts the granite cataclasite. Although welded tuff fault breccia and granite cataclasite are also pervasively fractured and fragmented, the fault cores are significantly affected by fragment size reduction due to intense abrasive wear and comminution. The 1.2‐m wide fault core includes fragments and a sharp dark layer composed of mafic volcanic rocks, which can be correlated with neighboring 1.6 Ma volcanic rocks. This observation places a younger constraint on the age of the fault core formation. Carbonate coating on basalt fragments in the 1.2‐m wide fault core has also been fractured indicating the repetition of intense fragmentation. Bifurcated, black and gray veins near the 1.2‐m wide fault core are likely injection veins, formed by the rapid injection of fine material within fault zones during seismic events. The granite‐derived fault gouge, characterized by hard granite fragments without intense brecciation and microfracturing, in a kaolinite‐rich clay matrix, is interpreted as the most recent slip zone within the exposed fault zone. A preview of published geological and hydrological studies of several fault zones shows that clay‐rich fault cores can exhibit much lower permeability than the adjacent damage zones represented in this present case by the welded tuff fault breccia and granite cataclasite.
Does lactate level in the first 12 hours of life predict mortality in extremely premature infants?
Authors: Hussain Farhat , Gilshenan Kristen , Gray Peter H
Published: April 2009

Aims:  To determine if high lactate levels within the first 12 h of life independently or in combination with Clinical Risk Index for Babies (CRIB) II can predict mortality in extremely premature babies.

Study Design:  A retrospective review of medical charts of babies born between 2001 and 2003 with birthweight <1000 g or gestation <28 weeks was performed. Blood gases and highest umbilical lactate levels in first 12 h of life were noted. Area under the curve (AUC) was calculated for lactate, CRIB and CRIB II as a predictor of mortality. The AUC for lactate and CRIB II were combined using discriminant analysis.

Results:  Two hundred nineteen infants were included in the study, 41 (18.7%) of whom died. The AUC for lactate was 0.67 (P < 0.001), while AUCs for CRIB and CRIB II score were 0.81 (P < 0.001) and 0.82 (P < 0.001), respectively. The AUC for the combined measure of lactate and CRIB II was 0.82, similar to CRIB II.

Conclusions:  Lactate predicts mortality in premature infants, but was found to be inferior to CRIB and CRIB II. Adding lactate level to CRIB II score does not improve its predictive ability.
Laparoscopic adrenalectomy: Troublesome cases
Authors: Kawabata Gaku , Shimogaki Hiroyoshi , Yamanaka Kunito , Matsushita Kei , Takechi Yoshizumi
Published: April 2009

Among 143 cases of laparoscopic adrenalectomy carried out from 1993 to the present, 13 patients in whom the surgical manipulation presented problems were examined. Problems occurred due to the condition of the adrenal tumors themselves in six patients, whereas problems occurred due to the operative history in four patients. There were three patients with no operative history but with strong intraperitoneal adhesion. In patients with a history of laparotomy in other fields such as open cholecystectomy, gastrectomy or colostomy, operations were possible in most patients by examining the trocar site preoperatively. Patients with strong adhesion even without a history of surgery could be handled by full separation of the adhesion during surgery. In patients with bleeding in the adrenal tumors, large adrenal tumors, or tumors impacted in the liver, methods such as changing the sequence of separation procedures were required. In patients with a history of renal subcapsular hematomas due to extracorporeal shock wave lithotripsy (ESWL), it was not possible to understand the conditions of adrenal or perinephritic adhesion in preoperative imaging diagnosis, but resection was possible by changing the order of separation procedures and by using optimal instruments and devices. As with any surgery, including open surgeries, it is necessary to obtain knowledge on how to deal with variations in laparoscopic adrenalectomy to assure safe outcomes and to always consider effective methods for coping with unexpected difficulties.
Eye‐conserving treatment in massive congenital orbital teratoma
Authors: Gündüz Kaan , Kurt Rengin Aslıhan , Heper Aylin Okçu
Published: April 2009

Abstract

An 8‐month‐old healthy girl presented with a left orbital mass, which orbital magnetic resonance imaging revealed to be a well‐circumscribed, mostly cystic lesion. The patient underwent orbitotomy via inferior fornicial conjunctival approach. Tumour shrinkage was accomplished by aspiration of the intralesional fluid, and the remaining debulked mass was removed by total excisional biopsy. Pathological examination revealed a cystic tumour lined mainly with keratinized stratified squamous epithelium, in addition to small foci of mucinous ciliated epithelium resembling respiratory epithelium. Histopathological findings were consistent with the diagnosis of mature orbital teratoma (hair follicles, adipose tissue, mature glial elements, choroid plexus‐like papillary organizations and small foci of cartilage in the cyst wall). Derivatives of all three germ lines were present. At 56‐month follow up, uncorrected visual acuity in the affected eye was 6/9. This case demonstrates the importance of decompressing the tumour before dissecting it from the periorbital tissues in an eye‐conserving approach to orbital teratoma.
Nurturing of surgical careers by the wellington surgical interest club
Authors: Srinivasa Sanket , Sapre Nikhil S.
Published: April 2009

The Royal Australasian College of Surgeons (RACS) has recently introduced the new Surgical Education and Training programme. The purpose of this was, in part, to help address the anticipated shortage of surgeons in the future, by streamlining the surgical training programme. The formation of the Wellington Surgical Interest Club (WSIC), a student‐led initiative, had several complementary goals. These included the desire to identify potential candidates for a career in surgery, promote a surgical career to students especially women, help students acquire basic surgical skills early, inform students about surgical careers, promote student involvement in surgical research and to create an effective mentorship model during undergraduate and junior surgical training. The strengths of WSIC are its goals, which are similar to those of the RACS with regard to promoting surgery as a career option; its easy reproducibility at other medical institutions; its ability to focus on issues of relevance to both students and junior doctors; and being a bridging solution at a time when early exposure to surgical specialties is both desired and necessary.
Surgical workforce in New Zealand: characteristics, activities and limitations
Authors: Raymont Antony , Simpson John
Published: April 2009

Planning the future surgical workforce is a vitally important activity in which the Royal Australasian College of Surgeons is actively engaged. This paper reports on a survey, undertaken in late 2005, of all vocationally registered New Zealand surgeons. It describes their age and gender distribution, their workload, the distribution of their work hours and limitations on their activities. It is hoped that this will contribute to planning of surgical services for the future. Of surgeons surveyed, 452 (73%) responded. Their mean age was 51 years and 7% were female. Recruitment has been stable at approximately 20 per year since 1990. New Zealand surgeons worked, on average, 48 h per week and could accommodate additional work. Seventy‐seven per cent of surgeons took after‐hours calls and reported a 55% chance of returning to the hospital each week (30% in the main population centres and 70% in other districts). Overall, surgeons spent 50% of their clinical time in private practice. Most surgeons experienced significant resource constraints in providing surgical care. The current workload of surgeons in New Zealand is acceptable but after‐hours duties, especially in secondary hospitals, may be unattractive. Surgical services are currently limited by institutional resources. If there is a substantial increase in the need for surgery in the future, surgical recruitment, which has been stable, should be increased.
Human adipose‐derived stem cells: isolation, characterization and applications in surgery
Authors: Locke Michelle , Windsor John , Dunbar P. Rod
Published: April 2009

The ideal stem cell for use in functional tissue engineering needs to be abundantly available, harvested with minimal morbidity, differentiated reliably down various pathways and able to be transplanted safely and efficaciously. Adult human adipose tissue contains a population of mesenchymal stem cells, termed ‘adipose‐derived stem cells’ (ASC), which seem to fulfil most, if not all, of these criteria. ASC can be harvested readily, safely, and in relative abundance by modern liposuction techniques. They are capable of differentiating into other mesenchymal tissue types, including adipocytes, chondrocytes, myocytes and osteoblasts. They also show angiogenic properties, with recent evidence of a potential role in healing radiotherapy‐damaged tissue, possibly due to their secretion of vascular endothelial growth factor. Similarly, they may have a role in healing chronic wounds, and as such are being investigated in phase 1 trials for their ability to aid healing of recurrent Crohn’s fistulae. Subsequently they have a wide range of potential clinical uses in all fields of surgery. This article reviews the current and potential clinical applications of ASC in relation to surgery, as well as methods for their isolation, differentiation and molecular characterization.
Simultaneous pancreas and kidney transplantation from organ donation after cardiac death
Authors: Suh Nancy , Ryan Brendan , Allen Richard , O’Connell Philip , Pleass Henry
Published: April 2009

Background:  The concept of organ donation after cardiac death (DCD) historically precedes the current practice of organ procurement from heartbeating donors meeting the brainstem death criteria. DCD has not gained widespread interest, however, due partly to initial fears that transplantation of such organs leads to suboptimal outcome.

Methods:  Available data on long‐term outcomes following simultaneous pancreas and kidney transplant (SPK) from DCD donors were reviewed, and it was found that the long‐term outcome is comparable to SPK from heartbeating donors. Australia’s first SPK from a DCD donor was performed.

Results:  The patient received a kidney and a pancreas from a young healthy donor after cardiac death, and at the time of writing was well with functioning grafts.

Conclusion:  SPK from donation after cardiac death is safe and should continue to be available for patients in need.
Smoking is a major risk factor for wound dehiscence after midline abdominal incision; case–control study
Authors: Abbas Saleh M. , Hill Andrew G.
Published: April 2009

Background:  The incidence of acute fascial wound dehiscence (AFWD) after major abdominal operations is as high as 3%. AFWD is associated with mortality rates of 15–20%. Male gender, advanced age and numerous systemic factors including malignancy hypoproteinemia and steroid use have been associated with increased risk. The aim of the present study was to investigate the association between smoking prevalence and AFWD.

Methods:  Middlemore Hospital records were retrieved from the 1997–2006 period for patients who had undergone midline abdominal surgery and developed AFWD. A return to the operating theatre for closure of the fascial dehiscence was required for study group inclusion. Each patient in the study group was matched to two control patients who had been admitted in the same year for surgery and who had a similar initial surgical intervention. Conditional logistic regression was used to calculate odds ratios with 95% confidence intervals, representing the risk of developing fascial wound dehiscence in smokers compared with the non‐smoking group.

Results:  There were 52 patients (32 male, 20 female) and 104 controls (64 male, 40 female). Median age for both groups was 63 years. A history of heavy tobacco use (≥20 pack‐years) was more prevalent in those who had AFWD (46%) compared with the control group (16%; P = 0.0002; odds ratio 3.7).

Conclusions:  Smoking is associated with an increased incidence of acute fascial wound dehiscence following laparotomy. It is not known whether smoking is a causal or a surrogate factor.
Oesophagectomy for tumours and dysplasia of the oesophagus and gastro‐oesophageal junction
Authors: Epari Krishna , Cade Richard
Published: April 2009

Background:  Neoadjuvant therapy, radical lymphadenectomy and treatment in high‐volume centres have been proposed to improve outcomes for resectable oesophageal tumours. The aim of the present study was to review the oesophagectomy experience of a single surgeon with a moderate caseload who uses neoadjuvant therapy selectively and performs a conservative lymphadenectomy.

Methods:  A retrospective review of prospectively collected data was performed. The study included 125 consecutive attempted oesophageal resections performed by a single surgeon (RC) from 1993 to 2006.

Results:  All patients were staged with computed tomography and also laparoscopy for lower third and junctional tumours. Endoscopic ultrasound was used in 69%. Seventy‐seven per cent were adenocarcinomas. Neoadjuvant therapy was used selectively in 23%. One hundred and twenty‐one resections were carried out, giving an overall resection rate of 97% with an R0 resection in 82%. In‐hospital mortality was 0.8%, clinical anastomotic leak 1.7% and median length of stay 14 days. Overall median and 5‐year survival were 46 months and 47%. Stage‐specific 5‐year survival was 100%, 71%, 41% and 21% for stages 0, I, II and III, respectively. Isolated local recurrence occurred in 8%.

Conclusions:  A moderate volume surgeon with specialist training in oesophageal resectional surgery can achieve a low mortality and anastomotic leak rate with good survival outcomes. The role for neoadjuvant therapy and radical lymphadenectomy is controversial and remains to be clearly defined. Accurate preoperative staging is essential for selection of patients for curative surgery with or without neoadjuvant therapy and for comparison of results.
Treatment of internal iliac artery aneurysms: single‐centre experience
Authors: Tsilimparis Nikolaos , Alevizakos Pavlos , Yousefi Sharham , Laipple Andreas , Hagemann Jürgen , Rogalla Patrik , Hanack Ulrich , Rückert Ralph I.
Published: April 2009

Background:  The aim of the present study was to analyse the short‐term results of treatment of internal iliac artery aneurysms (IIAA).

Methods:  In a prospective single‐centre cohort study all patients with IIAA (symptomatic or maximal diameter ≥30 mm) were evaluated for endovascular repair, which included coil embolization of the run‐off vessels and coverage of the orifice of the IIAA with a stent graft. Open repair was performed with aneurysm excision or aneurysmorrhaphy. Outcome criteria were technical and clinical success and complications of treatment.

Results:  In a period of 40 months 11 patients underwent operation for 12 IIAA. Nine aneurysms were repaired endovascularly and three with open repair. Coil embolization was routinely performed in all cases. At a median follow up of 18 months, technical and clinical success was 100%. Major complications included two early limb thromboses, a contrast‐agent‐induced nephropathy, and an intraoperative ureteric injury.

Conclusion:  Despite the limited number of patients, the present series, with good short‐term results, further supports the trend towards endovascular repair of suitable IIAA.
Is laparoscopic colectomy as cost beneficial as open colectomy?
Authors: Shabbir Asim , Roslani April C. , Wong Kutt‐Sing , Tsang Charles B. S. , Wong Hwee‐Bee , Cheong Wai‐Kit
Published: April 2009

Background:  Laparoscopic colectomy has yet to gain widespread acceptance in cost‐conscious health‐care institutions. The aim of the present study was to define the cost–benefit relationship of laparoscopic versus open colectomy.

Methods:  Thirty‐two consecutive patients undergoing elective laparoscopic colectomy (LC) by a single colorectal surgeon between August 2004 and September 2005 were reviewed. Cases were matched with a historical cohort undergoing elective open colectomy (OC) between June 2003 and July 2004. Demography, perioperative data, histopathology and cost were compared.

Results:  Both groups had similar demographics. Most resections (90.6%) were for cancer. Operative time was significantly longer for LC compared to OC (180 min vs 110 min, P < 0.001). Four patients (12.5%) in the LC group required conversion. LC patients, however, had lower median pain scores (3, 2 and 1 vs 6, 4 and 2 at 24, 48 and 72 h postoperatively, P < 0.001), faster resolution of ileus (3 vs 4 days, P < 0.001) and earlier discharge (6 vs 9 days, P < 0.001) compared to the OC group. As a result, overall hospital cost for both procedures was not significantly different (US$7943 vs US$7253, P = 0.41).

Conclusion:  Laparoscopic colectomy is as cost‐beneficial in the short term as open colectomy.
Cricotracheal reconstruction following external beam radiotherapy for recurrent thyroid cancer
Authors: Ashford Bruce G. , Clark Jonathan R.
Published: April 2009

Tracheal resection for invasive thyroid cancer is well described. Segmental tracheal or cricotracheal resection and reconstruction is an uncommon but established method in the treatment of invasive thyroid cancer. This has seldom been reported in a recurrence following external beam radiotherapy. Radiotherapy compromises healing and predisposes tracheal reconstruction to dehiscence. A fascia‐only radial forearm free‐flap reconstruction of a segmental cricotracheal resection is described.
Transanal endoscopic microsurgery
Authors: Platell Cameron
Published: April 2009

Transanal endoscopic microsurgery (TEM) is a minimally invasive surgical technique that was developed more than two decades ago to manage distal colorectal neoplasias. The aim of the current study was to present a prospective review of 7 years of experience in using this equipment. All patients undergoing TEM between 1999 and 2007 were prospectively evaluated. Patients underwent regular endoscopic follow up. Cumulative incidence probability analysis was used to calculate rates of recurrence. The study involved 232 patients, median age 68 years (interquartile range (IQR), 37–90). The median neoplasia area was 12 cm2 (IQR, 6–25 cm2) and the median height above the anal verge was 9 cm (IQR, 3–17 cm). Histology indicated 128 adenomas, 52 carcinomas in situ, and 52 adenocarcinomas. The median postoperative stay was 1 day (IQR, 1–3 days). There was one (0.5%) unplanned return to theatre and no postoperative deaths. Sixteen patients (6.9%) underwent more radical surgical procedures following the identification of carcinoma in the resected specimen. During a median follow up of 4.2 years (IQR, 2.6–6.2 years), the 5‐year cumulative incidence for local recurrence for benign pathology was 3.1% (95% confidence interval (CI): 1.2–6.7%, n = 180) and for cancers managed primarily by TEM excision it was 8.5% (95%CI: 1.4–23.9%, n = 36). TEM is an excellent treatment modality for benign rectal neoplasias of any size, and in any location. TEM is an oncologically inferior treatment for rectal cancer, however, when compared to more radical treatments. Its principal advantage in this setting is that it is associated with relatively minimal morbidity and mortality.
Surgical management of extracranial carotid artery aneurysms
Authors: Choudhary Anwar S. , Evans Richard J. , Naik Dilip K. , Tripathi Ramesh K. , Wickremesekera Janaka K.
Published: April 2009

Extracranial carotid artery aneurysms are uncommon and not much is known about them. The purpose of this study is to report the authors’ surgical experience and present a review of this entity. This single institution experience shows that resection of these aneurysms and restoration of flow can be accomplished using a number of surgical techniques with relatively low morbidity and mortality. Endovascular techniques are also increasingly being considered in the repair of these aneurysms, although long‐term data from such techniques are not currently available.