bluuebunny/crossref_metadata_2025 huggingface dataset:
Supplementation of the dilution medium after thawing with reduced glutathione improves function and the in vitro fertilizing ability of frozen‐thawed bull spermatozoa
Authors: Gadea Joaquín , Gumbao David , Cánovas Sebastián , García‐Vázquez Francisco Alberto , Grullón Luis Alberto , Gardón Juan Carlos
Published: May 2007

In this study, we evaluated the effects of glutathione (l‐γ‐glutamyl‐l‐cysteinylglycine; GSH) supplementation of the thawing extender on bull semen parameters to compensate for the decrease in GSH content observed during sperm freezing. To address these questions fully, we used a set of functional sperm tests. These included tests of sperm motility assayed by computer‐assisted semen analysis, membrane lipid packing disorder, spontaneous acrosome reaction, free radical production [reactive oxygen species (ROS) generation], sperm chromatin condensation, DNA fragmentation by terminal deoxynucleotidyltransferase‐mediated dUTP nick‐end labelling and acridine orange staining measured by flow cytometry. Finally, the in vitro penetrability of in vitro matured oocytes and the in vitro production of embryos were evaluated. The main findings emerging from this study were that addition of GSH to the thawing medium resulted in: (i) a higher number of non‐capacitated viable spermatozoa; (ii) a reduction in ROS generation; (iii) lower chromatin condensation; (iv) lower DNA fragmentation; (v) higher oocyte penetration rate in vitro and (vi) higher in vitro embryo production compared with control group. Nevertheless, GSH had no significant effect on motion parameters or the occurrence of the spontaneous acrosome reaction. Addition of GSH to the thawing extender could be of significant benefit in improving the function and fertilizing capacity of frozen bull spermatozoa.
Improved gene expression signature of testicular carcinoma in situ
Authors: Almstrup Kristian , Leffers Henrik , Lothe Ragnhild A. , Skakkebæk Niels E. , Sonne Si B. , Nielsen John E. , Meyts Ewa Rajpert‐De , Skotheim Rolf I.
Published: May 2007

The carcinoma in situ (CIS) stage is the common precursor of testicular germ cell tumours (TGCTs) that arise in young adults. Within the past decade genome wide gene expression tools have been developed and have greatly advanced the insight into the biology of TGCTs. Two independent data sets on global gene expression in testicular CIS have been previously published. We have merged the two data sets on CIS samples (n = 6) and identified the shared gene expression signature in relation to expression in normal testis. Among the top‐20 highest expressed genes, one‐third was transcription factors and the list included some ‘novel’ CIS markers (i.e. DOCK11 and ANXA3). Genes related to biological terms ‘nucleic acid binding’ and ‘translational activity’ (e.g. transcription factors and ribosomal proteins, respectively) were consistently and significantly over‐represented. Some of the significantly over‐expressed genes in CIS cells were selected for validation by RT‐PCR (IFI16, DOCK11, and ANXA3), immunohistochemistry (HLXB9), or in situ hybridization (IFI16). High‐level analysis utilizing the Ingenuity pathway analysis tool indicated that networks relating to ‘gene expression in cancer’ and ‘embryonic development’ were significantly altered and could collectively affect cellular pathways like the WNT signalling cascade, which thus may be disrupted in testicular CIS. The merged CIS data from two different microarray platforms, to our knowledge, provide the most precise CIS gene expression signature to date.
Infertility among couples in a population‐based study in Iran: prevalence and associated risk factors
Authors: Safarinejad Mohammad Reza
Published: May 2007

To explore the prevalence and risk factors of infertility in Iran, a total of 12 285 ever‐married women aged 15–50 years old and their husbands (if available) were interviewed by 82 female general practitioners and answered a self‐administered questionnaire on several aspects of infertility. They were identified from the national population in 30 counties, and invited to a confidential interview. Data were obtained about their age, education, marital status, toxic habits, medical history, disabilities and illnesses, help‐seeking, economy, ethnicity, geographic location, contraceptive use and age at which they had first intercourse. This study used the definition of childlessness proposed by World Health Organization: ‘the woman has never conceived despite cohabitation and exposure to pregnancy for a period of 2 years’. The overall prevalence of infertility was 8% (95% CI: 3.2–15.0). The weighted national estimate of primary infertility was 4.6% (95% CI: 3.6–5.2). There was a pronounced regional pattern in the levels of primary infertility. The primary infertility increased significantly from 2.6 to 4.3 to 5.5% for the 1985–1989, 1990–1994 and 1995–2000 marriage cohorts. The prevalence of secondary infertility was 3.4% (95% CI: 2.4–5.1). Overall the prevalence of infertility falls within a relatively wide range being high in the Southern counties, and low in the Northern counties. The probability of first pregnancy at the end of 2 years of marriage was 0.78 for all ever‐married women. The prevalence of infertility increased with age (linear chi‐square 198.012, 1 d.f., p = 0.01). The age pattern of infertility also varies quite markedly across the counties analysed. No effect of race was detected; neither the intercept (analysis of covariance p = 0.36) nor the slope of the age relationship was influenced by race (analysis of covariance p = 0.41). Infertility were observed as significantly higher in the presence of history of tubo‐ovarian surgery [odds ratio (OR): 1.43; 95% CI: 1.28–2.23; p = 0.01], salpingitis (OR: 2.34; 95% CI: 1.31–4.3; p = 0.016), ectopic pregnancy (OR: 2.45; 95% CI: 1.90–3.44; p = 0.04), varicocele (OR: 2.85; 95% CI: 1.61–5.20; p = 0.01) and cryptorchidism (OR: 3.81; 95% CI: 2.51–4.28; p = 0.031). This study provides a quantitative estimate of the prevalence and main risk factors for infertility in Iranian couples. Yet, further studies on the cause of primary and secondary infertility and geographical variations in the incidence and prevalence of infertility in Iran are needed.
Adjustment of vibratory signals to ambient temperature in a host‐searching parasitoid
Authors: KRODER STEFAN , SAMIETZ JÖRG , SCHNEIDER DAVID , DORN SILVIA
Published: May 2007

AbstractCertain ichneumonid parasitoids (Hymenoptera) use self‐produced vibrations transmitted on plant substrate, so‐called vibrational sounding, to locate their immobile concealed pupal hosts. An ambient temperature dependency with higher frequencies and intensities at higher temperatures is postulated because signals are of myogenic origin. Here, temperature influence on vibratory signals is analysed in the temperate parasitoidPimpla turionellaeunder different thermal conditions using plant‐stem models to elicit host‐searching behaviour. Signals are measured with laser Doppler vibrometry and analysed for time parameters and frequency components applying fast‐Fourier transformations. The results reveal an unexpected effect of ambient temperature on signals produced by the female wasps. Although average values of time parameters (pulse trains, pulse train periods, inter pulse duration) are unchanged by ambient temperature, the frequency parameters show an inverse thermal effect. Within the temperature range tested (8–26 °C), decreasing temperature leads to significantly higher frequency and intensity of the self‐produced vibrations in the temperate species. This inverse thermal effect may be explained by a temperature‐coupled signal production in the frequency domain to compensate negative low‐temperature effects on the mechanoreceptors by increased muscle activity. The option of heterothermy to produce signals reliably during vibrational sounding under low temperature is also discussed.
Influence of soil moisture on egg cold hardiness in the migratory locust Locusta migratoria (Orthoptera: Acridiidae)
Authors: QI XIAN‐LEI , WANG XIAN‐HUI , XU HONG‐FU , KANG LE
Published: May 2007

Abstract The present study investigates the influence of environmental moisture on cold hardiness of the migratory locust, Locusta migratoria. The water content of locust eggs kept in soil at 30 °C varies according to the moisture content of the substrate. In turn, it can significantly affect the supercooling point of locust eggs (range from −26 to −14.8 °C) and the mortality when exposed to subzero temperatures. Environmental moisture influences the supercooling capacity of eggs and their survival at low temperature. When locust eggs of the same water content are exposed to subzero temperatures under different soil moistures, their mortality varies between short‐time exposure and long‐time exposure at subzero temperatures. Given a short‐time exposure, mortality in wet soil is lower than in dry soil due to the buffering effect of soil water against temperature change. The pattern of egg mortality is reversed after long‐time exposure at low temperature, suggesting that inoculative freezing may be an important mortality factor. It is suggested that interactions between soil moisture and low temperature can influence the cold hardiness of locust eggs, and partial dehydration is beneficial to over‐wintering eggs of the migratory locust.
Post‐teneral protein feeding enhances sexual performance of Queensland fruit flies
Authors: PEREZ‐STAPLES DIANA , PRABHU VEENA , TAYLOR PHILLIP W.
Published: May 2007

Abstract Adult diet is an important determinant of sexual activity in many tephritid fruit flies. Whether availability of protein (hydrolysed yeast) in addition to sucrose influences sexual activity or longevity of male and female Queensland fruit flies (Bactrocera tryoni Froggatt, ‘Q‐flies’), and whether irradiation of flies as pupae modifies their dietary needs, is investigated. Previous studies on groups of flies suggest that protein is required for sexual maturation of females but not males. By contrast, this study of individual flies demonstrates that protein in the adult diet provides a massive boost to sexual activity of both males and females. Mating probability increases with age from 4‐14 days as the flies began to mature. However, mating probability reaches much higher levels when the flies are provided with protein. Although males and females mate at similar rates when provided with protein, females suffer a greater reduction in mating probability than males when deprived of protein. In addition to increased mating probability, access to dietary protein is also associated with reduced latency from onset of dusk until copulation. Furthermore, young male flies with access to dietary protein have longer copula duration than males fed only sucrose. Irradiation of flies as pupae has no apparent effect on mating probability, the latency to copulate or copula duration. However, when deprived of protein, sterile flies (especially males) suffer a greater reduction in longevity compared with fertile flies. Overall, access to dietary protein increases longevity for both males and females, although females live longer than males on both diets. These findings suggest that prerelease provision of dietary protein has the potential to greatly enhance the efficacy of Q‐flies used in the sterile insect technique.
The Arabidopsis cohesin protein SYN3 localizes to the nucleolus and is essential for gametogenesis
Authors: Jiang Ling , Xia Ming , Strittmatter Lara I. , Makaroff Christopher A.
Published: May 2007

α‐kleisins are core components of meiotic and mitotic cohesin complexes. Arabidopsis contains genes for four α‐kleisin proteins encoded by SYN genes. SYN1, a REC8 ortholog, is essential for meiosis, while SYN2 and SYN4 appear to be SCC1 orthologs and function in mitosis. Our analysis of AtSYN3 shows that it localizes primarily in the nucleolus of both meiotic and mitotic cells. Furthermore, analysis of plants containing an AtSYN3 T‐DNA knockout mutation demonstrated that it is essential for megagametogenesis and plays an important role in pollen. These results suggest that SYN3 may not function as part of a typical cohesin complex; rather it may have evolved a specialized role in controlling rDNA structure, transcription or rRNA processing.
The regulatory gamma subunit SNF4b of the sucrose non‐fermenting‐related kinase complex is involved in longevity and stachyose accumulation during maturation of Medicago truncatula seeds
Authors: Rosnoblet Claire , Aubry Catherine , Leprince Olivier , Vu Benoit Ly , Rogniaux Hélène , Buitink Julia
Published: May 2007

The sucrose non‐fermenting‐related kinase complex (SnRK1) is a heterotrimeric complex that plays a central role in metabolic adaptation to nutritional or environmental stresses. Here we investigate the role of a regulatory γ‐subunit of the complex, MtSNF4b, in Medicago truncatula seeds. Western blot indicated that MtSNF4b accumulated during seed filling, whereas it disappeared during imbibition of mature seeds. Gel filtration chromatography suggested that MtSNF4b assembled into a complex (450–600 kDa) at the onset of maturation drying, and dissociated during subsequent imbibition. Drying of desiccation‐tolerant radicles led to a reassembly of the complex, in contrast to sensitive tissues. Silencing of MtSNF4b using a RNA interference (RNAi) approach resulted in a phenotype with reduced seed longevity, evident from the reduction in both germination percentage and seedling vigour in aged RNAi MtSNF4b seeds compared with the wild‐type seeds. In parallel to the assembly of the complex, seeds of the RNAi MtSNF4b lines showed impaired accumulation of raffinose family oligosaccharides compared with control seeds. In mature seeds, the amount of stachyose was reduced by 50–80%, whereas the sucrose content was 60% higher. During imbibition, the differences in non‐reducing sugar compared with the control disappeared in parallel to the disassembly of the complex. No difference was observed in dry weight or reserve accumulation such as proteins, lipids and starch. These data suggest that the regulatory γ‐subunit MtSNF4b confers a specific and temporal function to SnRK1 complexes in seeds, improving seed longevity and affecting the non‐reducing sugar content at later stages of seed maturation.
Identification of regulatory pathways involved in the reacquisition of root growth after salt stress in Medicago truncatula
Authors: Merchan Francisco , Lorenzo Laura de , Rizzo Silvina González , Niebel Andreas , Manyani Hamid , Frugier Florian , Sousa Carolina , Crespi Martin
Published: May 2007

Root growth and function are determined by the action of environmental stresses through specific genes that adapt root development to these restrictive conditions. We have defined in vitro conditions affecting the growth and recovery of Medicago truncatula roots after a salt stress. A dedicated macroarray containing 384 genes, based on a large‐scale subtractive hybridization approach, was constructed and used to analyze gene expression during salt stress and recovery of root growth from this stress. Several potential regulatory genes were identified as being linked to this recovery process: a novel RNA‐binding protein, a small G‐protein homologous to ROP9, a receptor‐like kinase, two TF IIIA‐like and an AP2‐like transcription factors (TF), MtZpt2‐1, MtZpt2‐2 and MtAp2, and a histidine kinase associated with cytokinin transduction pathways. The two ZPT2‐type TFs were also rapidly induced by cold stress in roots. By analyzing transgenic M. truncatula plants showing reduced expression levels of both TFs and affected in their capacity to recover root growth after a salt stress, we identified potential target genes that were either activated or repressed in these plants. Overexpression of MtZpt2‐1 in roots conferred salt tolerance and affected the expression of three putative targets in the predicted manner: a cold‐regulated A (CORA) homolog, a flower‐promoting factor (FPF1) homolog and an auxin‐induced proline‐rich protein (PRP) gene. Hence, regulatory networks depending on TFIIIA‐like transcription factors are involved in the control of root adaptation to salt stress.
DELLA protein function in growth responses to canopy signals
Authors: Djakovic‐Petrovic Tanja , Wit Mieke de , Voesenek Laurentius A.C.J. , Pierik Ronald
Published: May 2007

Plants can sense neighbour competitors through light‐quality signals and respond with shade‐avoidance responses. These include increased shoot elongation, which enhances light capture and thus competitive power. Such plant–plant interactions therefore profoundly affect plant development in crowded populations. Shade‐avoidance responses are tightly coordinated by interactions between light signals and hormones, with essential roles for the phytochrome B photoreceptor [sensing the red:far red (R:FR) ratio] and the hormone gibberellin (GA). The family of growth‐suppressing DELLA proteins are targets for GA signalling and are proposed to integrate signals from other hormones. However, the importance of these regulators has not been studied in the ecologically relevant, complex realm of plant canopies. Here we show that DELLA abundance is regulated during growth responses to neighbours in dense Arabidopsis stands. This occurs in a R:FR‐dependent manner in petioles, depends on GA, and matches the induction kinetics of petiole elongation. Similar interactions were observed in the growth response of seedling hypocotyls and are general for a second canopy signal, reduced blue light. Enhanced DELLA stability in the gai mutant inhibits shade‐avoidance responses, indicating that DELLA proteins constrain shade‐avoidance. However, using multiple DELLA knockout mutants, we show that the observed DELLA breakdown is not sufficient to induce shade‐avoidance in petioles, but plays a more central role in hypocotyls. These data provide novel information on the regulation of shade‐avoidance under ecologically important conditions, defining the importance of DELLA proteins and GA and unravelling the existence of GA‐ and DELLA‐independent mechanisms.
Contribution of the CFTR gene, the pancreatic secretory trypsin inhibitor gene (SPINK1) and the cationic trypsinogen gene (PRSS1) to the etiology of recurrent pancreatitis
Authors: Tzetis M , Kaliakatsos M , Fotoulaki M , Papatheodorou A , Doudounakis S , Tsezou A , Makrythanasis P , Kanavakis E , Nousia‐Arvanitakis S
Published: May 2007

Acute recurrent/chronic pancreatitis (CP) is a complex multigenic disease. This is a case–control study consisting of 25 Greek patients with CP and a control population of 236 healthy Greek subjects. The whole coding area and neighboring intronic regions of the three genes were screened. Seventeen of 25 patients (68%) had mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) gene: nine compound heterozygotes with either mild or severe mutations and eight heterozygotes. Four patients (16%) carried CFTR‐modulating haplotypes V470‐TG11‐T5 and V470‐TG12‐T7. All were negative for PRSS1 gene mutations, while variants c.486C/T and c.738C/T were found in nine patients each, three homozygotes for the minor alleles. Two carried SPINK1 gene mutation p.N34S, one being transheterozygote with CFTR mutation p.F1052V. The promoter variant −253T>C was found in four individuals (one homozygous for the minor allele), all four being transheterozygotes with mutations in the CFTR gene as well. Finally two carried c.272C/T in the 3′ untranslated region, one being a p.N34S carrier as well. In total, 80% (20/25) of patients had a molecular defect in one or both of the CFTR and SPINK1 genes, suggesting that mutations/variants in the CFTR plus or minus mutations in the SPINK1, but not the PRSS1 gene, may confer a high risk for recurrent pancreatitis.
HLA‐B*5701 typing: evaluation of an allele‐specific polymerase chain reaction melting assay
Authors: Hammond E. , Mamotte C. , Nolan D. , Mallal S.
Published: May 2007

Inheritance of HLA‐B*5701 is a strong predictor of a hypersensitivity reaction to the anti‐HIV drug abacavir. The identification of susceptible individuals prior to the institution of abacavir therapy is therefore of clinical importance and has generated demand for a simple and rapid diagnostic test for carriage of HLA‐B*5701. In this study, we describe the development of such a method based on allele‐specific polymerase chain reaction (AS‐PCR) and melting curve analysis. Ninety‐six patient samples including 36 HLA‐B*5701‐positive samples and 60 HLA‐B*5701‐negative samples were analysed. Compared with sequence‐based typing, this method had 100% sensitivity and specificity for the HLA‐B*5701 allele. In conclusion, the AS‐PCR/melting curve approach minimises post‐polymerase chain reaction handling processing and provides an attractive alternative to currently described AS‐PCR methods.
Pre‐screening of miniature swine may reduce the risk of transmitting human tropic recombinant porcine endogenous retroviruses
Authors: Hector Ralph D. , Meikle Sharon , Grant Louise , Wilkinson Robert A. , Fishman Jay A. , Scobie Linda
Published: May 2007

Abstract: Background:  It has been reported that peripheral blood mononuclear cells from miniature swine are capable of transmitting human tropic porcine endogenous retrovirus (PERV) recombinants to both human and pig cells. It has been suggested that these recombinants are exogenous and/or driven by one or more critical loci present in the pig genome.

Methods and Results:  Genomic analysis of a miniature swine capable of transmitting human tropic replication competent (HTRC) recombinant PERV‐A/C identified a PERV‐C provirus in a region with homology to sequences located on chromosome 7. In “null” swine, incapable of in vitro transmission of PERV to human or pig cells, amplification using specific primers revealed that only two of five animals retained this locus in comparison to a total of five out of five transmitters (recombinant PERV‐A/C transmission to both human and pig cells) and seven out of seven non‐transmitters (replication of non‐recombinant PERV in pig cells only).

Conclusion:  These data suggest that further analysis of these loci may provide a genetic basis for identifying pigs that are less likely to transmit human tropic PERV and would, therefore, be more suitable as source animals for human xenotransplantation.
Porcine PD‐L1: cloning, characterization, and implications during xenotransplantation
Authors: Jeon Dae‐Hyun , Oh Keunhee , Oh Byoung C. , Nam Dong H. , Kim Chi H. , Park Hyung‐Bae , Cho Jaejin , Lee Jeong R. , Lee Dong‐Sup , Lee Gene
Published: May 2007

Abstract: Background:  Effective intervention achieved by manipulating cell‐mediated xenogeneic immune responses would critically increase the clinical feasibility of xenotransplantation as immediate hyperacute rejections become controllable through genetic modulations of donor organs. Endogenous negative regulatory signals like the programmed death 1 (PD‐1)‐programmed death ligand 1 (PD‐L1) system are candidate targets for the control of cell‐mediated xenogeneic immune response.

Methods:  A porcine PD‐L1 molecule was cloned using RACE (rapid amplification of cDNA ends) technology based on the human PD‐L1 sequence. The functional effects of cloned porcine PD‐L1 were tested on human CD4+ T cell activation using porcine PD‐L1‐transfected bystander cells. Cellular proliferation was monitored by [3H] thymidine incorporation, and human T cell apoptosis was measured by flow cytometry.

Results:  Porcine PD‐L1 (GenBank accession number AY837780) was found to have 73.8% sequence homology with human PD‐L1 and to contain two immunoglobulin domains in its extracellular region. Moreover, porcine PD‐L1 expressed on Chinese hamster ovary (CHO) cells inhibited human CD4+ T cell proliferation stimulated with anti‐CD3 only or anti‐CD3 plus anti‐CD28. Percentages of apoptotic activated human T cells increased by over 30% in the presence of porcine PD‐L1/CHO cells, and the addition of recombinant human PD‐1‐Fc fusion proteins during human T cell activation reversed the inhibitory effects of porcine PD‐L1.

Conclusions:  Cloned porcine PD‐L1 showed high sequence homology with human PD‐L1 and a similar molecular structure. Moreover, porcine PD‐L1 inhibited human CD4+ T cell activation in human PD‐1‐dependent manner, and this involved activated T cell apoptosis. The authors suggest that PD‐1‐PD‐L1 might play an important endogenous immune regulatory role during xenogeneic transplantation, and that the effective application of this system would improve transplanted xenogeneic organ survival.
Anaesthetic considerations for patients with a pre‐existing neurological deficit: are neuraxial techniques safe?
Authors: Vercauteren M. , Heytens L.
Published: May 2007

Pre‐existing neurological and muscular disease may be a specific concern for anaesthetists as they need to consider the effect of anaesthesia upon the disease, vice versa, and the interaction of anaesthesia with the medication taken by the patient. Despite a lack of controlled studies, many anaesthetists, being afraid of a claim, will prefer general rather than regional anaesthesia in these patients. Nevertheless regional anaesthesia certainly merits its place because it offers undeniable advantages. A good pre‐operative examination is very important while patients should also be informed about peri‐operative implications of anaesthesia, surgery and stress. Paraesthesias, epinephrine and high concentrations of local anaesthetics should be avoided in the majority of the diseases. Some diseases may benefit from epidural anaesthesia while for others a spinal technique may be the technique of preference. Special attention should be paid to patients with spinal stenosis despite recent reassuring reports with respect to safety of regional anaesthetic techniques. Anaesthetists should not automatically take all responsibility in case of progressive or new deficit after the procedure.
Divergent effects of ephedrine and phenylephrine on cardiovascular hemodynamics of near‐term fetal sheep exposed to hypoxemia and maternal hypotension
Authors: Erkinaro T. , Mäkikallio K. , Acharya G. , Päkkilä M. , Kavasmaa T. , Huhta J. C. , Alahuhta S. , Räsänen J.
Published: May 2007

Background:  We hypothesized that the administration of ephedrine and phenylephrine for maternal hypotension modifies cardiovascular hemodynamics in near‐term sheep fetuses.

Methods:  At 115–136 days of gestation, chronically instrumented, anesthetized ewes with either normal placental function or increased placental vascular resistance after placental embolization were randomized to receive boluses of ephedrine (n = 12) or phenylephrine (n = 12) for epidural‐induced hypotension after a short period of hypoxemia. Fetal cardiovascular hemodynamics were assessed by Doppler ultrasonography at baseline, during hypotension and after vasopressor treatment.

Results:  During hypotension, fetal PO2 decreased and proximal branch pulmonary arterial and pulmonary venous vascular impedances increased. Additionally, in the embolized fetuses, the time‐velocity integral ratio between the antegrade and retrograde blood flow components of the aortic isthmus decreased. These parameters were restored to baseline conditions by ephedrine but not by phenylephrine. With phenylephrine, weight‐indexed left ventricular cardiac output and ejection force decreased in the non‐embolized fetuses, and the proportion of isovolumetric contraction time of the total cardiac cycle was elevated in the embolized fetuses.

Conclusions:  After exposure to hypoxemia and maternal hypotension, ephedrine restored all fetal cardiovascular hemodynamic parameters to baseline. Phenylephrine did not reverse fetal pulmonary vasoconstriction or the relative decrease in the net forward flow through the aortic isthmus observed in fetuses with increased placental vascular resistance. Moreover, fetal left ventricular function was impaired during phenylephrine administration.
Single bolus of intravenous ketamine for anesthetic induction decreases oculocardiac reflex in children undergoing strabismus surgery
Authors: Choi S. H. , Lee S. J. , Kim S. H. , Kim J. H. , Kwon H. H. , Shin Y. S. , Lee K. Y.
Published: May 2007

Background:  Oculocardiac reflex (OCR) is a major complication of pediatric strabismus surgery. The aim of the present study was to determine whether a single bolus of intravenous (i.v.) ketamine for anesthetic induction can decrease OCR in children undergoing strabismus surgery.

Methods:  One hundred and twenty healthy children undergoing strabismus surgery were allocated to three groups using double‐blind randomization. Anesthesia was induced with propofol 3 mg/kg in Group P, ketamine 1 mg/kg in Group K1, or ketamine 2 mg/kg in Group K2. Anesthesia was maintained with 3% sevoflurane in 50% N2O/O2 in all patients. The baseline heart rate was obtained 30 s prior to the first traction of the extraocular muscle (EOM). OCR was defined as a development of arrhythmia or a decrease of more than 20% of the baseline heart rate during EOM traction.

Results:  The incidence of OCR was significantly lower in the ketamine groups (4/40 and 1/40 in Group K1 and K2, respectively) compared with the propofol group (14/40).

Conclusion:  A single bolus of i.v. ketamine 1 or 2 mg/kg for anesthetic induction results in a lower incidence of OCR than propofol when combined with sevoflurane for maintenance in children undergoing strabismus surgery.
Detecting local adaptation in a natural plant–pathogen metapopulation: a laboratory vs. field transplant approach
Authors: LAINE ANNA‐LIISA
Published: May 2007

Antagonistic coevolution between hosts and parasites in spatially structured populations can result in local adaptation of parasites. Traditionally parasite local adaptation has been investigated in field transplant experiments or in the laboratory under a constant environment. Despite the conceptual importance of local adaptation in studies of (co)evolution, to date no study has provided a comparative analysis of these two methods. Here, using information on pathogen population dynamics, I tested local adaptation of the specialist phytopathogen,Podosphaera plantaginis, to its host,Plantago lanceolataat three different spatial scales: sympatric host population, sympatric host metapopulation and allopatric host metapopulations. The experiment was carried out as a field transplant experiment with greenhouse‐reared host plants from these three different origins introduced into four pathogen populations. In contrast to results of an earlier study performed with these same host and parasite populations under laboratory conditions, I did not find any evidence for parasite local adaptation. For interactions governed by strain‐specific resistance, field studies may not be sensitive enough to detect mean parasite population virulence. Given that parasite transmission potential may be mediated by the abiotic environment and genotype‐by‐environment interactions, I suggest that relevant environmental variation should be incorporated into laboratory studies of parasite local adaptation.
Moult speed constrains the expression of a carotenoid‐based sexual ornament
Authors: SERRA L. , GRIGGIO M. , LICHERI D. , PILASTRO A.
Published: May 2007

We investigated the effect of moult speed on the expression of a sexually selected, carotenoid‐based feather ornament in the rock sparrow (Petronia petronia). We experimentally accelerated the moult speed of a group of birds by exposing them to a rapidly decreasing photoperiod and compared the area and the spectral characteristics of their ornaments with those of control birds. Birds with accelerated moulting rate showed a smaller yellow patch with lower yellow reflectance compared to their slow‐moulting counterparts. Considering that the time available for moulting is usually constrained between the end of the breeding season and migration or wintering, carotenoid feather ornaments, whose expression is mediated by moult speed, may convey long term information about an individual's condition, potentially encompassing the previous breeding season. Furthermore, the observed trade‐off between moult speed and ornament expression may represent a previously unrecognized selective advantage for early breeding birds.
Childhood invasive pneumococcal disease: A hospital‐based study from Malaysia
Authors: Lim Li Han , Lee Way Seah , Parasakthi Navaratnam
Published: May 2007

Aim:  New conjugate vaccine for Streptococcus pneumoniae has been introduced in Malaysia recently. Information on infection due to S. pneumoniae in Malaysian children is scarce. We conducted a retrospective chart review of childhood invasive pneumococcal disease (IPD) presented to a single centre in Malaysia.

Methods:  A retrospective review of 5 years and 4 months of all cases of IPD in children younger than 14 years of age (May 1999–August 2004) seen at the University of Malaya Medical Centre (UMMC), Kuala Lumpur, was conducted. Cases were identified from the record of Department of Medical Microbiology, UMMC.

Results:  IPD was identified in 50 children (median age 1.1 years, range 2 weeks−14 years) during the study period. Seventy‐six per cent of the cases were younger than 2 years of age. Pattern of infections noted include definite pneumonia (n = 8), probable pneumonia (n = 33), meningitis (n = 4), bacteraemia without focus (n = 4) and septic arthritis (n = 1 each). Pre‐morbid diseases were present in 28% of all cases. Complications (n = 12, 24%) due to IPD were seizures (n = 5), pleural effusion/empyema (n = 4), cerebral palsy (n = 2) and deafness (n = 1). No deaths were attributed to IPD. Sixty‐two per cent of the pneumococcal isolates were penicillin non‐susceptible and were detected throughout the study period.

Conclusions:  IPD is associated with high morbidity, particularly among young children. Majority of the isolates were penicillin‐non‐susceptible strains. Additional information on the serotype of S. pneumoniae isolated is necessary to assess the potential impact of immunisation on preventing pneumococcal infection in Malaysia.
Infant care practices associated with sudden infant death syndrome: Findings from the Pacific Islands Families study
Authors: Schluter Philip J , Paterson Janis , Percival Teuila
Published: May 2007

Aim:  To report infant care practice prevalence for known modifiable sudden infant death syndrome (SIDS) risk factors among a generally disadvantaged yet low‐SIDS rate population of mothers with Pacific infants.

Methods:  The Pacific Islands Families study follows a cohort of Pacific infants born at a large tertiary hospital in South Auckland, between 15 March and 17 December 2000. Maternal self‐report of infant care practices was undertaken at interview 6 weeks post‐partum.

Results:  Overall, 1376 mothers self‐reported upon their care practices for infants with median age of 7 weeks. Current maternal smoking was reported by 29%. Of infants: 50% were fully breastfed; 1% were placed prone to sleep; 50% usually bed‐shared with their mother and 12% usually bed‐shared with a mother who smoked; and 94% usually and 1% occasionally slept in the same room as their mother. Except for room sharing (P = 0.09), there were significant differences in these practices between the three major Pacific Island ethnic subgroups (all P < 0.001).

Conclusion:  Adoption of bed‐sharing and room‐sharing practices appears to be saving Pacific infants’ lives, even though the New Zealand Cot Death Association has discouraged bed‐sharing and not actively promoted room sharing. Mothers need to receive adequate information antenatally about the risks and benefits of room‐sharing, bed‐sharing and safe‐sleeping practices and environments should they decide or have no option but to bed‐share.
Association of endothelial nitric oxide synthase gene intron 4 polymorphism with end‐stage renal disease
Authors: BELLINI MARIA H , FIGUEIRA MÁRCIA N , PICCOLI MICHELLY F , MARUMO JÚLIO T , CENDOROGLO MAYSA S , NETO MIGUEL C , DALBONI MARIA A , BATISTA MARCELO C , GOES MIGUEL Â , SCHOR NESTOR
Published: May 2007

Background:  Nitric oxide (NO) released from endothelial cells is related to the maintenance of physiological vascular tone. The impairment of endothelial NO generation brought about by gene polymorphism is considered one of the deterioration factors in progressive renal disease. In the endothelial nitric oxide synthase (eNOS) intron 4 polymorphism, the presence of the aa genotype has been associated with cardiovascular and renal disease. The aim of this study was to investigate the presence of eNOS gene intron 4 polymorphism in patients with end‐stage renal disease (ESRD).

Methods:  A total of 114 patients and 94 controls were studied. DNA specimens were extracted from blood and amplified by polymerase chain reaction. The alleles were separated by agarose gel electrophoresis. Genotype distribution and allele frequencies were compared between groups using the chi‐squared test.

Results:  Statistical analysis revealed that the frequency of the eNOS4 genotype aa was significantly different in ESRD patients and in controls (P = 0.016, OR = 2.07, CI 95%: 1.14–3.74). There was also a statistically significant difference between ESRD patients and controls regarding allele carriers (P = 0.004; OR = 2.26; CI 95%: 1.29–3.96). When the frequencies of allele carriers in the diabetic nephropathy group and in the control group were compared, a significant difference was found (P = 0.034, OR = 2.28; CI 95%: 1.04–5.00).

Conclusion:  This study showed a strong correlation between eNOS4a polymorphism and end‐stage renal disease.
The differential regulation of Smad7 in kidney tubule cells by connective tissue growth factor and transforming growth factor‐beta1
Authors: QI WEIER , CHEN XINMING , TWIGG STEPHEN , ZHANG YUAN , GILBERT RICHARD E , KELLY DARREN J , POLLOCK CAROL A
Published: May 2007

Aims:  Smad7 is an inhibitory Smad that regulates transforming growth factor‐β (TGF‐β) signaling. Connective tissue growth factor (CTGF) is recognized as a potent downstream mediator of the fibrogenic effects of TGF‐β1. SMAD binding sites have been identified in both TGF‐β and CTGF promoters. The effect of CTGF on Smad7 expression and its role in the regulation of Smad7 induced by TGF‐β1 in renal tubular cells is unknown.

Methods:  Human model of proximal tubular cells (HK‐2 cells) was used and confirmed using a diabetic rat model. RT‐PCR was performed to measure Smad7, TGF‐β1 and Smad2 and ELISA was performed to measure active TGF‐β1. CTGF or TGF‐β1 was silenced in HK‐2 cells using siRNA methodology.

Results:  TGF‐β1 induced Smad7 in a time‐dependent manner, peaking at 30 min (P < 0.0005) but sustained up to 24 hrs (p < 0.005). Conversely, CTGF reduced Smad7, which was maximal at 24 hrs (p < 0.05). This was supported by our in vivo data demonstrating that CTGF protein significantly increased while Smad7 mRNA level was reduced in a diabetic rat model. The basal expression level of Smad7 decreased in TGF‐β1 silenced cells compared to cells transfected with non‐specific siRNA (p < 0.0005). The basal expression level of Smad7 increased in CTGF silenced cells (p < 0.05), which was increased by TGF‐β1 (p < 0.005). Both mRNA and protein levels of TGF‐β1 decreased in CTGF silenced cells (p < 0.05 and p < 0.005 respectively) accompanied by reduction in Smad2 mRNA level in CTGF silenced cells.

Conclusions:  Smad7 is induced rapidly by TGF‐β1 limiting the response to TGF‐β1. CTGF likely plays a key role in promoting TGF‐β1 activity by decreasing the availability of Smad7 and increasing Smad2.
Is it time to revisit residual renal function in haemodialysis? (Review Article)
Authors: NG TSUN G , JOHNSON DAVID W , HAWLEY CARMEL M
Published: May 2007

SUMMARY:  Residual renal function (RRF) is not currently emphasized for patients undergoing haemodialysis (HD). The role of RRF is well recognized in the peritoneal dialysis population as studies have clearly demonstrated a survival benefit with preservation of RRF. There is however, data to suggest that RRF is important in HD patients as well. Contemporary HD therapies using high flux biocompatible synthetic dialysers, bicarbonate buffered ultrapure dialysis fluids with ultrafiltration control appear to allow better preservation of RRF. The long held belief that peritoneal dialysis is better at preserving RRF than HD may no longer be true. More robust studies are required to determine the relative importance of RRF in HD and strategies to best preserve this vital asset.
The pathogenic role of IgA1 O‐linked glycosylation in the pathogenesis of IgA nephropathy (Review Article)
Authors: BARRATT JONATHAN , SMITH ALICE C , FEEHALLY JOHN
Published: May 2007

SUMMARY:  Numerous abnormalities of the IgA immune system have been reported in IgAN but the most consistent finding remains aberrant IgA1 O‐linked glycosylation of the IgA1 hinge region. The defect comprises reduced galactosylation of O‐linked N‐acetylgalactosamine residues with or without changes in the terminal sialylation of the O‐linked sugars. Aberrant O‐galactosylation has been found in serum IgA1, in IgA1 isolated from tonsillar lymphocytes, and in IgA1 eluted from mesangial deposits. There is evidence that changes in IgA1 O‐galactosylation lead to IgA immune complex formation and mesangial IgA deposition. Mesangial cells exposed to these IgA immune complexes proliferate and adopt a pro‐inflammatory phenotype; they secrete cytokines, chemokines, growth factors and extracellular matrix components promoting glomerular inflammation and glomerulosclerosis. Recent evidence suggests that the control of IgA1 O‐glycosylation is linked to class switching from IgD to IgA1 synthesis and that the pattern of IgA1 O‐glycosylation may be programmed at the time of initial antigen encounter. IgA1 glycosylation varies between systemic and mucosal sites and the association of aberrant IgA1 galactosylation with low affinity, polymeric IgA1 antibodies against mucosal antigens suggests undergalactosylated IgA1 may in fact be a mucosal glycoform of IgA1. Although suited to the mucosal compartment, when these IgA1 glycoforms enter the systemic circulation in appreciable quantities they deposit in the mesangium and trigger glomerular inflammation. This review will discuss the evidence for the role of IgA1 O‐glycosylation in the pathogenesis of IgAN and propose an explanation for the presence of aberrantly O‐glycosylated IgA1 in the circulation of patients with IgAN.
DISCREPANCIES IN GLEASON SCORING OF PROSTATE BIOPSIES AND RADICAL PROSTATECTOMY SPECIMENS AND THE EFFECTS OF MULTIPLE NEEDLE BIOPSIES ON SCORING ACCURACY. A REGIONAL EXPERIENCE IN TAMWORTH, AUSTRALIA
Authors: Ooi Kevin , Samali Ramin
Published: May 2007

Background:  The aim of this study was to review the discrepancies in Gleason scores (GS) of prostate biopsies and radical prostatectomy specimens and the effects of multiple‐needle biopsies on scoring accuracy.

Methods:  One hundred patients who had undergone consecutive radical prostatectomies (RP) between January 2004 and May 2006 were reviewed retrospectively. Patient information including age, prebiopsy prostate‐specific antigen levels, biopsy GS, RP GS and pathology details were recorded and compared.

Results:  The concordance rate of biopsy GS and RP GS was found to be at 43%, with 46% of biopsy specimens being undergraded. Eleven per cent of the specimens were overgraded. The accuracy was fairly similar when specimens were reported by the same or different pathologists, at 42 and 44%, respectively. The accuracy of biopsy GS improved with increasing number of biopsies taken.

Conclusion:  There are significant discrepancies in Gleason scoring of biopsy and RP specimens, with a concordance rate of 43% and undergrading rate of 46%. Increasing the number of biopsies helps improve scoring accuracy. Clinicians and patients need to be mindful when deciding cancer treatment options, in view of these discrepancies.
VASCULAR SURGERY CONSULTS: A SIGNIFICANT WORKLOAD
Authors: Koh Cherry E. , Walker Stuart R.
Published: May 2007

Background:  Patients with vascular disease typically suffer from widespread atherosclerosis and complex multisystem pathologies. As a result, it may be expected that significant portion of a vascular surgeon’s inpatient workload is derived from consultations from other inpatient specialist units. This aspect of the workload of vascular surgeons is poorly documented.

Methods:  A prospective audit on inpatient vascular consultations was carried out. All vascular admissions to the Vascular Surgery unit at the Royal Hobart Hospital as well as inpatient referrals by other units over a 6‐month period were recorded on a database. The data were analysed to evaluate the number of inpatient consultations, the reason for the consultation and its outcome.

Results:  Most inpatient referrals were derived from internal medicine (32%), renal, endocrinology and plastic surgery units (26, 13 and 9%, respectively). Sixty‐four per cent of all referrals required intervention with most of these patients having been referred from renal and endocrinology units.

Conclusion:  In our experience, 50% of the vascular surgeon’s inpatient workload is derived from inpatient referrals. Sixty‐four per cent of referrals required some form of vascular intervention. This aspect of vascular workload is significant and has not been previously documented. It is time‐consuming and also resource consuming and this needs to be taken into consideration when allocating theatre resources and during rostering.
GALL BLADDER POLYPS IN SCLEROSING CHOLANGITIS: DOES THE 1‐CM RULE APPLY?
Authors: Leung Universe C , Wong Phillip Y , Roberts Ross H , Koea Jonathan B
Published: May 2007

Introduction:  Polyps of the gall bladder (PLG) are common findings in radiological investigations of the gall bladder and most are benign although carcinoma of the gall bladder can arise in PLG. In the general population PLG less than 1 cm in diameter are thought to have a low risk of malignancy and can be cautiously observed.

Methods:  All patients undergoing surgical resection for gall bladder cancer were entered into a prospective database. Four patients with primary sclerosing cholangitis (PSC) presenting with gall bladder cancer in a PLG are studied.

Results:  Four patients (two men; median age 46.5 years, range 37–71 years) presented with PLG and known histories of PSC. All patients were shown to have PLG of size between 7 mm × 8 mm and 25 mm × 14 mm on imaging with no radiological evidence of carcinoma. Tumour markers carcinoembryonic antigen and CA19‐9 were within the normal range in all patients. All patients were managed with cholecystectomy. Two patients with T1 tumours remain alive and well at 2 and 4 years post‐cholecystectomy. Of the remaining two patients with T2 tumours, one underwent re‐resection of the liver bed and portal lymph nodes and remains alive and well at 12 months. The remaining patient developed an abdominal wall recurrence 12 months after cholecystectomy. She has also undergone resection with postoperative radiation therapy and remains well after 12 months of clinical follow up.

Conclusion:  Gall bladder polyps, which are common and are usually benign in the general population, are often malignant in PSC. Regardless of size, any PLG in a patient with PSC should be considered for cholecystectomy.