bluuebunny/crossref_metadata_2025 huggingface dataset:
Influence of gender and interleukin‐10 deficiency on the inflammatory response during lung infection with Pseudomonas aeruginosa in mice
Authors: Guilbault Claudine , Stotland Peter , Lachance Claude , Tam Mifong , Keller Anna , Thompson‐Snipes Luann , Cowley Elizabeth , Hamilton Thomas A. , Eidelman David H. , Stevenson Mary M. , Radzioch Danuta
Published: March 2003

Cystic fibrosis females have a worse prognosis compared to male patients. Furthermore, cystic fibrosis patients infected with Pseudomonas aeruginosa have been shown to have dysregulated cytokine profiles, as higher levels of tumour necrosis factor alpha (TNF‐α), interleukin (IL)‐8, and lower levels of IL‐10 are found in the bronchoalveolar lavage fluid compared to healthy controls. The present study was aimed at investigating the importance of gender and IL‐10 in the susceptibility of C57BL/6 mice to pulmonary infection with Pseudomonas aeruginosa. We found that wildtype females were more susceptible than males to infection, as we observed greater weight loss, higher bacterial load, and inflammatory mediators in their lungs. IL‐10 knockout mice, both females and males, had higher levels of TNF‐α in the lungs compared to wildtype mice and maintained higher levels of polymorphonuclear cells and lower levels of macrophages for a longer period of time. Our results demonstrate that the number of bacteria recovered from the lungs of IL‐10 knockout male mice was significantly higher than that observed in their wildtype male counterparts and we show that neutralization of IL‐10 in infected female mice for a prolonged period of time leads to increased susceptibility to infection. Results reported in this study clearly demonstrate that females, both wildtype and IL‐10 knockout mice are more susceptible to Pseudomonas aeruginosa infection than males, and that they mount a stronger inflammatory response in the lungs.
Resistant mice lacking interleukin‐12 become susceptible to Trypanosoma cruzi infection but fail to mount a T helper type 2 response
Authors: Galvão Da Silva Ana Paula , Jacysyn Jacqueline F. , Abrahamsohn Ises De Almeida
Published: March 2003

Interleukin‐12 (IL‐12) is essential to resistance to Trypanosoma cruzi infection because it stimulates the synthesis of interferon‐γ (IFN‐γ) that activates macrophages to a parasiticidal effect. Investigation of mice deprived of IL‐12 genes (IL‐12 knockout mice) has confirmed the important role of IL‐12 and IFN‐γ in controlling parasitism in T. cruzi infection. However, it has not yet been addressed whether a shift towards a T helper type 2 (Th2) pattern of cytokine response occurred in these mice that might have contributed to the aggravation of the infection caused by IL‐12 deprivation. We examined the course of T. cruzi (Y strain) infection and the regulation of cytokine responses and nitric oxide production in C57BL/6 IL‐12 p40‐knockout mice. The mutant mice were extremely susceptible to the infection as evidenced by increased parasitaemia, tissue parasitism and mortality in comparison with the control C57BL/6 mouse strain (wild‐type) that is resistant to T. cruzi. A severe depletion of parasite‐antigen‐specific IFN‐γ response, without an increase in IL‐4 or IL‐10 production, accompanied by reduced levels of nitric oxide production was observed in IL‐12 knockout mice. We found no evidence of a shift towards a Th2‐type cytokine response. In IL‐12 knockout mice, the residual IFN‐γ production is down‐regulated by IL‐10 but not by IL‐4 and nitric oxide production is stimulated by tumour necrosis factor‐α. Parasite‐specific immunoglobulin G1 antibody levels were similar in IL‐12 knockout and wild‐type mice, whereas IL‐12 knockout mice had much higher levels of immunoglobulin G2b.
Interleukin‐18 plays a role in both the alum‐induced T helper 2 response and the T helper 1 response induced by alum‐adsorbed interleukin‐12
Authors: Pollock Kevin G. J. , Conacher Margaret , Wei Xiao‐Qing , Alexander James , Brewer James M.
Published: March 2003

Previous studies have shown that the antigen‐specific T helper 2 (Th2) response induced by alum adjuvants is interleukin (IL)‐4 independent. As a role for IL‐18 in Th2 induction has recently been described, in addition to its role in enhancing Th1 responses, we have studied the Th2 response induced by ovalbumin (OVA) adsorbed to alum in wild‐type and IL‐18‐deficient mice. Our results indicate that while endogenous IL‐18 facilitates alum‐induced IL‐4 production, OVA‐specific immunoglobulin G1 (IgG1) and IgE production remain unaffected. Furthermore, antigen‐specific Th1 responses induced with alum/IL‐12‐adsorbed OVA were demonstrated to be highly IL‐18 dependent. Despite these observations, injection of BALB/c mice with exogenous IL‐18 adsorbed to alum/OVA did not alter IL‐4 or interferon‐γ production by T cells and had little effect on the relative production of IgG1/IgG2a antibody subclasses compared with alum/OVA inoculated mice. However, the previously described synergism between IL‐12 and IL‐18 in Th1 induction was evident as the Th1‐promoting activity of alum/IL‐12 against adsorbed OVA was greatly augmented by the coadministration of IL‐18. These results indicate that while alum‐induced IL‐18 can facilitate Th2 induction, the addition of exogenous IL‐18 cannot further enhance the alum‐induced Th2 response.
A new perspective on the dynamics of information technology‐enabled strategic change
Authors: Hsiao R. L. , Ormerod R. J.
Published: March 2003

This paper explores the dynamic nature of information technology (IT)‐enabled strategic change by using empirical evidence from a variety of organizational contexts. The pilot research described here uses the MIT 1990s framework (Scott‐Morton, 1991) as the underpinning theory to challenge the dominant approach to the management of strategic change. The preliminary findings provide new insights into how strategic change is pursued and offer a new perspective from which the propositions suggested by Scott‐Morton (1991) and Yetton et al. (1994) can be reformulated. Four change patterns (archetypes) are identified that describe planned or emergent modes of change, driven by different change elements under various circumstances. These findings lead to a redesign of the M/T 1990s framework and suggest new ways of understanding how strategic change can be sustained. Further research is required to explore the link between the archetypes identified and the various methods of change.
Telehealth acquires meanings: information and communication technologies within health policy
Authors: Klecun‐Dabrowska Ela , Cornford Tony
Published: March 2003

Abstract.

Over the last decade, British health policy has increasingly considered the role of information and information technologies in the provision of health care. Recently, there is a growing interest in new health applications, often referred to as telemedicine and telehealth, and incorporating a diverse range of services that can be provided in electronic form over various telecommunications networks. This paper discusses how such use of information and communication technologies (ICTs) in health acquires meanings through a policy process, and what implications it has for telehealth in particular. This is done through a hermeneutic exploration of four principal UK health policy papers published between 1989 and 1998.
Managing the crises in intranet implementation: a stage model
Authors: Damsgaard Jan , Scheepers Rens
Published: March 2003

In the seventies, Nolan was the first to address the need for a descriptive stage theory concerning the planning, organizing and controlling activities associated with managing the organizational computer resource. The arrival of newer technologies, such as those based on the Internet, calls for fresh approaches in terms of their implementation and management. Intranet technology, which is based on Internet technology, differs from other types of IT in terms of its characteristics, use and implementation. We propose a four‐stage model for intranet implementation and management. Each stage is portrayed by seven general characteristics. We propose that, in order to ensure intranet institutionalization, three existential crises must be overcome. First, if a sponsor does not nurture the intranet, it cannot evolve beyond its experimental beginnings. Second, if a critical mass of both users and content cannot be reached simultaneously, the intranet will not progress. Finally, if the intranet remains uncontrolled, it will be perceived to be useless, and therefore users will abandon it.
Transaction attributes and software outsourcing success: an empirical investigation of transaction cost theory
Authors: Wang Eric T. G.
Published: March 2003

Abstract. In recent years, an increasing amount of attention has been paid to information systems (IS) outsourcing by practitioners as well as academics. However, our understanding of the factors that affect outsourcing success is hardly complete. By adopting transaction cost theory (TCT) as the theoretical foundation, this study analyses the implications of transaction attributes on the consequences of customized software outsourcing practice. The research model includes three exogenous variables (contractor reputation, asset specificity and uncertainty) and two endogenous variables (post‐contractual opportunism and outsourcing success). The moderating effects of asset specificity on the relationships between uncertainty and the endogenous variables are also examined. Based on data collected in Taiwan, a research model is constructed to test the hypotheses derived from the theory. The empirical evidence is generally supportive of the theory but with some important exceptions. In particular, contractor reputation and uncertainty have the predicted effects on the contractor’s post‐contractual opportunism perceived by the client and outsourcing success, but asset specificity shows a negative effect on post‐contractual opportunism and a positive effect on outsourcing success, which are opposite to the typical predictions of TCT. Thus, in addition to the supportive findings of the theory, this study also raises an important research question regarding the effects of asset specificity on outsourcing for future research to explore.
Sequence of a mosquito ribonucleotide reductase cDNA and evidence for gene amplification in hydroxyurea‐resistant cells
Authors: Shotkoski F. A. , Jayachandran G. , Stamatoyannopoulos G. , Fallon A. M.
Published: March 2003

Ribonucleotide reductase is essential for production of the deoxyribonucleotide substrates required for DNA synthesis in all eukaryotic cells. The full‐length cDNA encoding a mosquito ribonucleotide reductase R2 subunit was obtained from Aedes albopictus cells using a polymerase chain reaction (PCR)‐based approach. The cDNA contained 1197 nucleotides, and encoded a 398 amino acid R2 protein. Overall, mosquito R2 shared approximately 70% amino acid sequence identity with R2 proteins from vertebrates, but conservation at the N‐terminus of the protein was relatively low. The sequence of R2 cDNA was identical in hydroxyurea‐resistant mosquito cells and in wild‐type cells, while the R2 gene copy number was increased ten to twentyfold in resistant cells.
Intraspecific nucleotide variation at the pheromone binding protein locus in the turnip moth, Agrotis segetum
Authors: LaForest S. M. , Prestwich G. D. , Löfstedt C.
Published: March 2003

Inter‐ and intraspecific amino acid variability in the pheromone binding proteins (PBPs) of the Lepidoptera is believed to contribute to a molecular mechanism of pheromone blend discrimination. Messenger RNA coding for PBP sequence in Agrotis segetum (Noctuidae) was cloned, and nucleotide and inferred amino acid variation across a 769‐bp region of a PBP locus was studied in two populations. A single gene copy was fully sequenced, revealing an intron/exon structure conserved with distant saturniids. While several nucleotide substitutions are predicted to result in amino acid replacement, tests for the presence of natural selection suggest that the observed variation is neutral. A phylogenetic analysis provides evidence that the two populations are in the process of genetic isolation.
An easter‐like serine protease from Anopheles gambiae exhibits changes in transcript abundance following immune challenge
Authors: Paskewitz S. M. , Reese‐Stardy S. , Gorman M. J.
Published: March 2003

The nucleotide and deduced amino acid sequence of a serine protease (AgSp14D1) from the human malaria vector, Anopheles gambiae, is presented. The gene product is a 360 amino acid protein that contains two domains and has the highest sequence similarity to the Drosophila melanogaster serine protease easter and to prophenol oxidase activating enzyme (pPAE) from Manduca sexta. The catalytic domain is at the carboxy terminus and has the conserved serine, histidine and aspartic acid residues found in serine proteases as well as six cysteines common to invertebrate enzymes. The amino terminus contains critical cysteines that define a clip (=disulphide knot) domain which places this gene product in a subfamily of regulatory serine proteases that includes not only easter and pPAE but also the Drosophila proteins masquerade, stubble and snake as well as proclotting enzyme and factor B from the horseshoe crab. In situ hybridization to the polytene chromosomes detects a single band at 14D and Southern analysis with a probe from the 5′ end of the gene confirms the single copy status of this gene. Northern analysis reveals changes in transcript abundance during development and following blood feeding. Interestingly, this analysis also shows an increase in transcript levels following wounding or injection of bacteria.
Systematic screening of Anopheles mosquito genomes yields evidence for a major clade of Pao‐like retrotransposons
Authors: Cook J. M. , Martin J. , Lewin A. , Sinden R. E. , Tristem M.
Published: March 2003

We developed a degenerate PCR procedure to simultaneously amplify products from divergent retrotransposon families within the genomes of Anopheles mosquitoes. The procedure required cloning of multiple PCR products, but more than half of the clones subsequently sequenced were of retrotransposon origin. These included Copia‐like and LINE retrotransposons, as well as the first Gypsy‐like retrotransposons reported from mosquitoes. Furthermore, some Anopheles retrotransposon sequences showed similarity to the divergent Pao element from the silkmoth Bombyx mori. Phylogenetic analyses provided consistently strong bootstrap support (> 95%) for a major clade of Pao‐like retrotransposons, which includes five mosquito sequences and the recently discovered Drosophila retrotransposons BEL and ninja. This appears to represent a new family of Pao‐like LTR‐retrotransposons distinct from the Copia and Gypsy families.
Subset partitioning of the ribosomal DNA small subunit and its effects on the phylogeny of the Anopheles punctulatus group
Authors: Beebe N. W. , Cooper R. D. , Morrison D. A. , Ellis J. T.
Published: March 2003

A phylogenetic study, based on maximum parsimony, of ten species in the Anopheles punctulatus group of malaria vectors from the south‐west Pacific was performed using structural and similarity‐based DNA sequence alignments of the nuclear small ribosomal subunit (SSU = 18S). The structural alignment proved to be more informative than a computer generated similarity‐based alignment. Analyses involving the full structural sequence alignment (2169 bp) and the helical regions (1547 bp) resolved a single tree of the same topology, while analyses using the similarity based alignment could not resolve the group. Studies on the three structural domains of the nuclear rDNA SSU identified domain 2 (769 bp) as the only region informative at the sibling‐species level and resulted in the same tree as the full structural sequence and helical regions. The main conclusions of these studies were that the An. punctulatus group formed two clades: a Farauti clade containing members displaying an all black scaled proboscis (An. farauti 1–3 and 5–7) and a Punctulatus clade containing members that display some degree of white scaling on the proboscis (An. farauti 4, An. punctulatus and An. species near punctulatus). Anopheles koliensis can display either proboscis morphology and was positioned basal to the Farauti Clade. These results do not fully concord with those derived from the mitochondrial COII gene.
Ultrastructural and molecular identification of a Wolbachia endosymbiont in a spider, Nephila clavata
Authors: Woo Oh Hyun , Gwang Kim Mi , Woon Shin Sang , Sook Bae Kyung , Joon Ahn Young , Park Ho‐Yong
Published: March 2003

Wolbachia‐like bacteria were observed in the egg cells of golden orb‐weaving spider, Nephila clavata, by means of transmission electron microscopy. The bacteria exhibited the typical morphology of Wolbachia, including three enveloping membranes. Based on the amplification and sequencing of partial 16S rDNA and ftsZ gene, the bacteria were identified as Wolbachia, intracellular, transovarially inherited α‐proteobacteria in invertebrates. Phylogenetic analysis based on 16S rDNA and ftsZ gene sequences invariably indicated that the intracellular bacteria from N. clavata belonged to group A Wolbachia, which were found only from insects. Clustering of Wolbachia from N. clavata with group A Wolbachia indicates that the bacteria were probably transferred horizontally between insects and the spider.
Secondary structure and conserved motifs of the frequently sequenced domains IV and V of the insect mitochondrial large subunit rRNA gene
Authors: Buckley T. R. , Simon C. , Flook P. K. , Misof B.
Published: March 2003

We have analysed over 400 partial insect mitochondrial large subunit (mit LSU) sequences in order to identify conserved motifs and secondary structures for domains IV and V of this gene. Most of the secondary structure elements described by R. R. Gutell et al. (unpublished) for the LSU were identified. However, we present structures for helices 84 and 91 that are not recognized in previous universal models. The portion of the 16S gene containing domains IV and V is frequently sequenced in insect molecular systematic studies so we have many more sequences than previous studies which focused on the complete mitochondrial LSU molecule. In addition, we have the advantage of investigating several sets of closely related taxa. Aligned sequences from thirteen insect orders and nine secondary structure diagrams are presented. These conserved sequence motifs and their associated secondary structure elements can now be used to facilitate the alignment of other insect mit LSU sequences.
Cloning of two novel P450 cDNAs from German cockroaches,Blattella germanica(L.): CYP6K1 and CYP6J1
Authors: Wen Z. , Scott J. G.
Published: March 2003

Two novel P450 cDNAs, CYP6K1 and CYP6J1, were isolated from German cockroaches,Blattella germanica(L). Both CYP6K1 and CYP6J1 are typical microsomal P450s and their deduced amino acid sequences share a number of common characteristics with other members of the P450 superfamily. Both CYP6K1 and CYP6J1 showed the highest per cent identity (based on the deduced amino acid sequence) to CYP6L1 fromB. germanicaand CYP6H1, a putative ecdysone 20‐hydroxylase fromLocusta migratoria. Using a CYP6K1 probe, two mRNA signals (~2.5 and ~2.1 kb) were detected in all life stages. Both signals were just detectable in the eggs and became stronger in later instars. The strongest signals were detected in the fifth and sixth instars as well as in adults. These two bands were also detected in the abdomens and in the remainder of bodies of both male and female adults. Southern blots suggest the two mRNA bands detected in the Northern blot might be a result of alternative splicing. No signal could be detected at any life stage using the CYP6J1 probe, suggesting that CYP6J1 was expressed at a low level.
Sequence analysis and expression of a virus‐like particle protein, VLP2, from the parasitic wasp Venturia canescens
Authors: Reineke A. , Asgari S. , Ma G. , Beck M. , Schmidt O.
Published: March 2003

Endoparasitoid wasps produce maternal protein secretions, which are transported into the body of insect hosts at oviposition to regulate host physiology for successful development of their offspring. Venturia canescens calyx fluid contains so‐called virus‐like particles (VLPs) that are essential for immune evasion of the developing parasitoid inside the host. VLPs consist of four major proteins. In this paper, we describe the isolation and molecular cloning of a gene (vlp2) that is a constituent of VLPs and discuss its possible role in VLP structure and function.
Cloning of two cDNAs encoding isoforms of a pacifastin‐related precursor polypeptide in the desert locust, Schistocerca gregaria: analysis of stage‐ and tissue‐dependent expression
Authors: Simonet G. , Claeys I. , November T. , Wataleb S. , Janssen T. , Maes R. , De Loof A. , Vanden Broeck J.
Published: March 2003

A novel serine protease inhibitor peptide family, designated as the ‘pacifastin family’, has recently been described in insects (locusts, lepidopterans) and crustaceans (crayfish). This study presents the cDNA cloning of two isoforms of SGPP‐3, a novel pacifastin‐related precursor in the desert locust, Schistocerca gregaria, which codes for three putative inhibitor peptides. The precursor isoforms differ at a single amino acid position in the third, C‐terminal peptide. Northern blot analysis confirmed the presence of two different transcripts (0.75 and 0.90 kb). Both transcripts are most abundant in the fat body and appear to be strongly regulated during the moulting cycle. In addition, the amount of transcript proved to be strictly regulated in the ovaries during the female reproductive cycle.
A method of adapting gutta‐percha master cones for obturation of open apex cases using heat
Authors: Kerezoudis N. P. , Valavanis D. , Prountzos F.
Published: March 2003

Clinical technique It is generally accepted that the success of root‐canal treatment is mainly dependent on the proper cleaning, shaping and hermetic obturation of root canals. Obturation of the root canal is of importance as 60% of endodontic failures are attributable to incomplete obliteration of the root‐canal system. The clinical application of many obturation techniques used today demands the preservation of the natural apical construction or the preparation of an artificial equivalent during chemo‐mechanical preparation. However, in clinical practice there are cases where the apical foramen is wide because of over‐instrumentation, root‐end resection during periradicular surgery, root resorption or because the apex of the root is incompletely formed. Thus the preparation of an artificial apical stop is very difficult to achieve. It is a common experience that performing usual gutta‐percha condensation techniques in such canals often results in overfilling and therefore special obturation techniques are needed. Some clinical cases of teeth with wide apical foramen treated by a special obturation method are presented in this paper. In this method the end point of the primary gutta‐percha cone is elasticized with a heated instrument and inserted into the root canal to record the internal morphology of the apical portion.
Response of class II molecule‐expressing cells and macrophages to cavity preparation and restoration with 4‐META /MMA‐TBB resin
Authors: Kamal A. M. M. , Okiji T. , Suda H.
Published: March 2003

Aim

The aim was to test the hypothesis that the resin and bonding agent 4‐META/MMA‐TBB (4‐META), has the potential to prevent transdentinal antigenic challenges.

Methodology

Class I cavity preparation and immediate restoration with 4‐META were made in the maxillary right first molars of 36 six‐week‐old Wistar rats. Contralateral teeth with an unrestored cavity served as positive control (cavity without 4‐META) group. The maxillary first molars of 12 age‐matched normal rats (total 24 teeth) were also examined as negative control (intact tooth group). At 3 or 28 days after cavity preparation, the teeth were subjected to immunoperoxidase staining using OX6 (anticlass II molecules) and ED1 (antimacrophages) as primary antibodies.

Results

A total of 10 teeth were not available for histological examination. In the teeth filled with 4‐META at 3 days, the density of OX6+ and ED1+ cells in the coronal pulp was significantly higher than that in the intact tooth group. At 28 days, formation of sound reparative dentine was noted and the density of the immunocompetent cells was comparable to the intact teeth. In the teeth without 4‐META at 3 days, pulpal abscess was observed in 14 out of 16 and the density of OX6+ and ED1+ cells was significantly increased (P < 0.001, paired t‐test) compared with the 4‐META group. Partial pulp necrosis had developed in the teeth without 4‐META at 28 days.

Conclusions

Restoration with 4‐META significantly reduced transdentinal antigenic challenges. This property may have special implications for 4‐META’s capacity to protect the dentine/pulp complex.
Effect of Nd:YAG laser irradiation on the apical leakage of obturated root canals: an electrochemical study
Authors: Park D. S. , Lee H. J. , Yoo H. M. , Oh T. S.
Published: March 2003

Aim

The purpose of this laboratory study was to evaluate the effect of Nd:YAG laser irradiation on the apical leakage of obturated root canals using an electrochemical method.

Methodology

Forty extracted single‐rooted teeth were selected and the anatomic crown of each tooth was removed. The specimens were randomly divided into four groups. In group 1, the root canals were prepared with K‐files and irradiated with Nd:YAG laser (5 W, 20 Hz) via a 300 µm optical fibre. Then the root canals were obturated with laterally condensed gutta‐percha and Pulp Canal Sealer EWT. In group 2, the root canals were treated with the same method as those of group 1 but without laser irradiation. In group 3, the root canals were prepared with ProFiles, laser irradiated and then obturated with vertically condensed gutta‐percha and Pulp Canal Sealer EWT. In group 4, the root canals were treated with the same method as those of group 3 but without laser irradiation. The electric resistance between standard and experimental electrodes in the canals was measured over a period of 10 days.

Results

At 2 h, groups 1 and 3 irradiated with laser had significantly less apical leakage than group 2 (P < 0.05). After 10 days, group 4 had the highest leakage, followed by groups 2, 1 and 3; the differences between the groups was statistically significant (P < 0.05).

Conclusions

Laser irradiation following root canal preparation reduced apical leakage following root canal obturation.
The microscopic diagnosis and treatment of a mandibular second premolar with four canals
Authors: Al‐Fouzan K. S.
Published: March 2003

Aim

The purpose of this article is to report the case of a mandibular second premolar with four distinct canals.

It is generally recognized that incomplete instrumentation and cleaning of root canals will lead to failure in root‐treated teeth. Before root canal treatment is performed, the clinician should be aware of the configuration of the pulp space of the tooth that is to be treated. Frequently, root canals are left untreated because the clinician fails to identify their presence, particularly in teeth that have anatomical variations or additional root canals. Traditionally, additional canals have been detected by clinical examination of the floor of the pulp chamber, and sometimes found radiographically. More recently microscopic examination of the pulp chamber using endodontic microscopy has assisted the identification of extra canals. A case report is presented that deals with the successful treatment of a mandibular second premolar with four canals.

Key learning points

Even in teeth with a low frequency of abnormal root canal anatomy, the possibility of additional root canals has to be considered in the clinical and radiographic examination of the patient.

The ability to recognize and locate unsuspected canals is enhanced by microscopic investigation of the pulp chamber.
Measurement of strain on tooth roots during post removal with the Eggler post remover
Authors: Castrisos T. V. , Palamara J. E. A. , Abbott P. V.
Published: March 2003

Castrisos T, Palamara JEA, Abbott PV. Measurement of strain on tooth roots during post removal with the Eggler post remover. International Endodontic Journal, 35, 337–344, 2002.

Aim The aim was to measure root surface strains in teeth when removing cast post/cores with the Eggler post remover.

Methodology Two groups of 10 teeth each were tested: group 1 had 1 mm thickness of dentine coronally, and group 2 had 2 mm thickness of dentine. After root filling, 10 mm long cast post/cores were constructed and cemented with zinc phosphate cement, and strain gauges were applied to the roots. The post/cores were removed with the Eggler post remover whilst strain measurements were being recorded. Posts were removed twice: initially along the long axis of the tooth and then at a 10° angle to the long axis. Comparisons between groups 1 and 2 were analysed statistically with the Mann–Whitney U‐test whilst strains within each group were analysed with the Wilcoxon Signed Rank test at the 95% level of confidence.

Results There was no significant difference in the strains measured between groups 1 and 2, and no significant difference within each group when removing posts along the long axis of the tooth and at a 10° angle. Three teeth in group 1 and one tooth in group 2 fractured when removing posts at the 10° angle. Three fractures were small slivers of dentine at the point where the Eggler’s repeller arms contacted the tooth mesially and distally, whilst one tooth (from group 1) fractured obliquely.

Conclusions Post removal with the Eggler device is a relatively safe procedure but care must be taken when there is a possibility of pulling the post out in a nonaxial direction or when less than 1 mm of dentine surrounds the apical end of the post.
Bacterial and fungal microleakage of AH26 and AH Plus root canal sealers
Authors: Miletić I. , Prpić‐Mehičić G. , Maršan T. , Tambić‐Andrašević A. , Pleško S. , Karlović Z. , Anić I.
Published: March 2003

Aim To evaluate the penetration of Candida albicans alone and a combination of bacteria through root canals filled with gutta‐percha and one or other root canal sealers, AH26 and AH Plus.

Methodology Eighty teeth were randomly divided into two groups of 40 teeth each and obturated with gutta‐percha using either AH26 or AH Plus sealer. A further 10 teeth served as negative controls and 10 as positive controls. The external surface of each root, except the apical 2 mm, was covered with two layers of nail varnish. The teeth were inserted into Eppendorf plastic tubes and suspended in glass bottles containing sterile Schaedler broth. Streptococcus mutans, Streptococcus mitis, Prevotella melaninogenica and Lactobacillus acidophilus were placed in the access cavities of 20 teeth filled with AH26 and 20 with AH Plus. Candidaalbicans was placed in the access cavities of the other teeth. The culture medium with microorganisms was changed every 7 days. Every 72 h bacterial or fungal growth in the broth was tested up to a period of 90 days.

Results Leakage in the experimental teeth occurred between 14 and 87 days. Leakage was present in 47% of all samples. From the samples with AH26, 45% leaked bacteria and 60% leaked fungi; whilst from the samples with AH Plus, 50% leaked bacteria and 55% fungi. There was no statistically significant difference in penetration of bacteria and fungi between the sealers.

Conclusion In this in vitro study, gutta‐percha and the sealers AH26 and AH Plus allowed leakage of bacteria and fungi.
Effect of calcium hydroxide as a supplementary barrier in the radicular penetration of hydrogen peroxide during intracoronal bleaching in vitro
Authors: Lambrianidis T. , Kapalas A. , Mazinis M.
Published: March 2003

Lambrianidis T, Kapalas A, Mazinis M. Effect of calcium hydroxide as a supplementary barrier in the radicular penetration of hydrogen peroxide during intracoronal bleaching in vitro. International Endodontic Journal, 35, 985–990, 2002.

Aim To examine pH changes in the cervical external root surface, when calcium hydroxide was used as a supplementary barrier to the protective base material during intracoronal bleaching.

Methodology Twenty‐eight single‐rooted human premolars extracted for orthodontic reasons were instrumented with K‐Flex files, obturated with gutta‐percha and subjected to thermocatalytic bleaching. The teeth were divided into four groups. In group A, a glass‐ionomer cement barrier was placed at the cemento–enamel junction (CEJ) level and in group C, the barrier was placed 1 mm apical to the CEJ. In groups B and D, Ca(OH)2 was placed in contact and apical to the glass‐ionomer cement at the CEJ and 1 mm apical to the CEJ, respectively. The teeth were placed in vials containing distilled water and the pH values of the medium surrounding the teeth were recorded after 1, 2, 4, 10 and 15 days, following renewal of the medium.

Results The pH in the medium became acidic in all groups. No statistically significant differences existed between groups for all the experimental days (P = 0.790).

Conclusion The placement of Ca(OH)2 as a supplementary barrier during intracoronal bleaching did not have a significant effect in reversing the acidic pH created at the external root surface in vitro. Its potential effect during these procedures in vivo needs to be further investigated.
Asymmetrical testicular weights in mammals, birds, reptiles and amphibia
Authors: YU ZONG‐HAN
Published: March 2003

The testes of different classes of animals (mammals, birds, reptiles and amphibia) were weighed. Some species showed inconsistent left–right asymmetric testicular weights, while other species (including amphibians, reptiles, some birds and some mammals) showed consistent asymmetry in their weights. In rodents, for example, five strains of mice consistently exhibited asymmetrical testes, with the right testis always being heavier than the left. In contrast, another strain of mice showed inconsistent bilateral asymmetry of the testes.
Performance of the sperm quality analyser in predicting the outcome of assisted reproduction
Authors: MAHMOUD  , GORDTS  , VEREECKEN  , SERNEELS  , CAMPO  , ROMBAUTS  , COMHAIRE
Published: March 2003

The present study was undertaken to assess the relationship between the results of conventional semen analysis and the sperm motility index (SMI) as measured by the sperm quality analyser (SQA), and to evaluate these in relation to the fertilization and/or pregnancy outcome of assisted reproduction. SMI determinations and conventional semen analyses were performed on 223 samples from subfertile men in two laboratories in Leuven (n = 136) and Antwerp (n = 87), and on spermatozoa prepared on a Percoll gradient (n = 136) used for treatment of male factor infertility in 57 cycles of intrauterine insemination (IUI), 44 attempts at in vitro fertilization (IVF) and 31 attempts at intracytoplasmic sperm injection (ICSI). SMI values for native semen correlated significantly with sperm concentration, motility and morphology. Multiple regression analysis revealed sperm concentration after preparation, and the concentration of motile spermatozoa with normal morphology and SMI (before preparation) to be the independent determinants for SMI after preparation. SMI values were significantly higher after, than before, preparation ( p < 0.0001). In regular IVF (n = 44) the percentage of fertilized oocytes correlated significantly ( p < 0.05) with sperm motility (A + B%, r = 0.33), with the percentage of spermatozoa with normal morphology (r = 0.46) before preparation, with the values of SMI both before and after preparation (r = 0.54, r = 0.48), with sperm concentration (r = 0.34) and with the motile sperm concentration (r = 0.29) after preparation. For the occurrence of pregnancy (all treatment methods), comparison of areas under ROC curves (AURC) indicated motile sperm concentration after preparation, as well as SMI both before and after preparation, to have the highest AURC, with no significant difference between these values as far as predictive power was concerned. These results indicate that the SQA allows for rapid evaluation of sperm characteristics and of the effectiveness of sperm preparation techniques. However, it is not superior to conventional semen analysis in predicting the outcome of assisted reproduction.
The effect of biological dyes and contrast media on the vas deferens in Long Evans rats
Authors: CHANG  , CHEN  , HSIEH  , SHUN  , LAI
Published: March 2003

The conventional diagnostic procedure of vasography utilizes a contrast medium to evaluate the patency of the vas deferens. With the development of microsurgical reconstruction for obstructive azoospermia in the past two decades, intraoperative vasography with saline or biological dye injection has replaced the use of radiographic contrast media. However, there are few reports on the effect of biological dyes on the healthy vas deferens. Therefore, we used experimental vasography to evaluate histological changes and functional patency of the vas deferens after infusion with a contrast medium and biological dye.

Four groups of 10 Long Evans male rats were injected by vasopuncture with 1% methylene blue, 1% gentian violet and 38% Urografin or saline into the vas deferens. The animals were killed 30 days later, and the vasa deferentia were excised and examined for histological changes and for functional patency. Vasopuncture with saline injection induced minimal change both at the puncture site and in the distal vas deferens. In both the Urografin‐ and methylene blue‐injected groups, inflammation at the puncture site was found in 20–22% of cases, and 10–11% of cases revealed functional obstruction of the vasal lumen. In the gentian violet‐injected group, severe histological and obliterated changes were found in all cases. Leakage of the dye and contrast medium or the sperm reaction may be responsible for the inflammation; otherwise, methylene blue and urografin did not seem to be harmful to the vas deferens. Although gentian violet is a blue dye, as is methylene blue, it has marked destructive effects on the vas deferens. It is concluded that some biological dyes used for vasal injection can cause occlusion of the vasal lumen, while inflammatory responses can occur from placing a needle transmurally.
Effects of long‐term use of testosterone enanthate. II. Effects on lipids, high and low density lipoprotein cholesterol and liver function parameters
Authors: Tyagi Alpana , Rajalakshmi  , Jeyaraj D. Antony , Sharma  , Bajaj
Published: March 2003

The present study was designed to evaluate the effects of long‐term administration of testosterone enanthate (TE) on lipid and liver function parameters in rhesus monkeys (n=9) maintained under controlled dietary conditions. Bimonthly administration of 50 mg of TE increased serum testosterone into the supraphysiological range one day after injection and peak levels were seen on day 3, followed by a decrease to above baseline values by day 14. High density lipoprotein cholesterol (HDL‐C) levels decreased gradually; compared to baseline values, the decline was significant from the 19th month of injection until the first month of recovery. The increase in low density lipoprotein cholesterol (LDL‐C) levels and the LDL‐C/HDL‐C ratio during the treatment period was not significant compared to baseline values; however, when compared to control animals, HDL‐C and LDL‐C levels and the LDL‐C/HDL‐C ratio were significantly elevated from the 12th month until the end of the treatment period. All lipid parameters recovered by the end of the treatment period. Control animals (n=9) did not show significant changes in HDL‐C and LDL‐C levels and the LDL‐C/HDL‐C ratio during the study period. Total cholesterol levels decreased in control (n=9) and treated animals from 6 to 15th months of the treatment period, coinciding with the feeding of sprouted grams to animals. TE injections did not change the levels of triglycerides, alkaline phosphatase or bilirubin in control and treated animals. However, transaminase (SGOT and SGPT) levels increased following TE injections and remained elevated until the end of injections followed by a return to baseline values or below during the recovery period. These effects could be due to the pharmacokinetic profile of TE in which testosterone levels were elevated to supraphysiological values after injections. The recovery of the TE‐induced changes in lipid parameters and liver transaminases is reassuring but the changes in these parameters during TE injections indicate the need for long‐acting androgens with better pharmacokinetic properties.
Male reproductive health research needs and research agenda: Asian and Pacific perspective
Authors: Wang Yi‐Fei
Published: March 2003

Enhancing male reproductive health, and increasing men’s participation in it, involves encouraging a range of positive reproductive health and social behaviour by men to help ensure women’s and children’s well‐being. More intellectual work–including research programmes–is urgently needed to clarify the conceptual framework for male reproductive health. At the Asia and the Pacific Symposium ‘Intra‐regional Cooperation in Reproductive Health Research’ (Shanghai, China, 12–13 October 1998) the Symposium participants identified regional research needs and recommended a regional reproductive health research agenda, which addresses six key issues related to male reproductive health: (i) male contraceptive technology; (ii) reproductive tract infections/sexually transmitted diseases and male infertility; (iii) male involvement in reproductive health; (iv) male adolescent reproductive health; (v) male reproductive ageing; and (vi) environment and male reproductive health. One of the major challenges now facing us is the elaboration of a comprehensive, yet realistic, male reproductive health research agenda that reflects the needs and demands of Asian developing countries. Making full use of an interdisciplinary approach is of strategic importance to achieve this.
Sperm number and condition affect the number of basal cells and their expression of macrophage antigen in the murine epididymis
Authors: Seiler Petra , Cooper Trevor G. , Nieschlag Eberhard
Published: March 2003

Unilateral ligation of the mid‐corpus epididymis, the proximal vas deferens and imposition of an abdominal temperature for 6 days as well as bilateral castration for 3, 6 or 14 days, resulted in a change in epithelial composition of the adult murine epididymis with regard to the number and antigen expression of basal cells. There were fewer basal cells per tubule cross‐section with fewer expressing F4/80 antigen when spermatozoa were absent from the proximal lumen following short‐term castration. Conversely, more basal cells with more of them demonstrating macrophage antigen expression were evident when more or damaged spermatozoa were in the proximal lumen after corpus ligation and exposure to abdominal temperature or in the cauda after long‐term withdrawal of androgen support. By contrast, ligation of the vas deferens did not lead to tubule distension, and hence sperm accumulation, and did not alter the basal cell population in the cauda epididymis. The data suggest that epididymal basal cells respond in number and macrophage antigen expression to the presence of sperm autoantigens in the lumen with little dependence on circulating androgens. These changes may represent responses to minimise the interaction of sperm autoantigens with the immune system and the risk of immunological infertility.
Escherichia coli‐induced alterations of human spermatozoa. An electron microscopy analysis
Authors: Diemer  , Huwe  , Michelmann  , Mayer  , Schiefer  , Weidner
Published: March 2003

This study evaluated if the negative influence of Escherichia coli on the motility of human spermatozoa is a consequence of E. coli‐induced ultrastructural alterations. Suspensions of spermatozoa were artificially infected with E. coli from a serotyped, pathogenic strain and incubated at 37 °C for 6 h. After incubation, spermatozoa were fixed in glutaraldehyde, stained with osmium tetroxide and ruthenium red and embedded in Spurr®‐resin followed by ultramicrotomy. The sections were analysed subsequently by use of transmission electron microscopy. Uninfected suspensions of spermatozoa in medium and bacterial suspensions served as controls. Negative contrast technique was performed to facilitate visualization of ultrastructural details of the bacterial capsule after experimental exposure to spermatozoa. Electron microscopic evaluation revealed multiple and profound alterations in the ultrastructure of spermatozoa such as membrane defects and cytoplasmic vacuoles exclusively in spermatozoa of infected samples (> 90%). Morphological alterations involved all superficial structures of spermatozoa, in particular the plasma membrane of the mid‐piece and neck as well as the inner and outer acrosomal membrane of the acrosome, indicating that morphological defects account for the immobilization of spermatozoa by E. coli. The results suggest that E. coli infection of ejaculates results in immobilization and impaired acrosomal function in human spermatozoa, findings that support the indication for antimicrobial chemotherapy in symptomatic and silent infections that affect the ejaculate.
Reduction in libido and fertility of male rats by administration of the nitric oxide (NO) synthase inhibitor N‐nitro‐L‐arginine methyl ester
Authors: Ratnasooriya  , Dharmasiri  , Wadsworth
Published: March 2003

The role of nitric oxide (NO) in libido and fertility of male rats was investigated by administration of the NO synthase inhibitor N‐nitro‐L‐arginine methyl ester (L‐NAME) (25 or 50 mg/kg/day). L‐NAME caused marked reduction of precoital sexual behaviour, and a failure of most rats to mount or ejaculate during the test interval. In most matings that were successful, recovered spermatozoa were present in normal numbers. In mating experiments, L‐NAME profoundly reduced the fertility of male rats. In those animals that did succeed in mating, the quantal pregnancy and the number of implants were reduced. After cessation of treatment with L‐NAME, the fertility parameters returned close to normal. The inactive stereoisomer, D‐NAME, caused none of the above effects when administered to rats. The results suggest that NO is essential for the expression of normal libido and fertility in male rats. It is likely that NO is required both in the male reproductive tract and in the brain.
Immunocytochemical detection of mitochondrial dihydroorotate dehydrogenase in human spermatozoa
Authors: Dietz Carsten , Hinsch Elvira , Löffler Monika
Published: March 2003

In mammalian cells the requirement for pyrimidines is met by uridine phosphate (UMP) de novo synthesis and, to a greater or lesser extent, by salvage of free nucleosides. The fourth enzyme of the de novo synthesis, the mitochondrially bound dihydroorotate dehydrogenase (DHODH) was the focus of the present study. Rabbit anti‐DHODH IgG, which was generated using an immunization protocol with truncated recombinant human DHODH protein and purified by an immunosorbent method, was used for immunocytochemical detection and localization of this enzyme in ejaculated human spermatozoa. The presence of DHODH protein was demonstrated by Western blotting of solubilized membrane fractions with peroxidase conjugated anti‐rabbit IgG in combination with chemiluminescence detection. Indirect immunofluorescence microscopy, using Cy3‐conjugated anti‐rabbit IgG, revealed specific binding in the midpiece of spermatozoa. As these cells no longer have a demand for de novo biosynthesis of pyrimidines, we hypothesize that the pathway could serve a specialized function in nitrogen or zinc metabolism during the process of spermiogenesis and/or epididymal maturation.