bluuebunny/crossref_metadata_2025 huggingface dataset:
Reconciling user and project manager perceptions of IT project risk: a Delphi study1
Authors: Keil Mark , Tiwana Amrit , Bush Ashley
Published: March 2003

Abstract. In an increasingly dynamic business environment characterized by fast cycle times, shifting markets and unstable technology, a business organization’s survival hinges on its ability to align IT capabilities with business goals. To facilitate the successful introduction of new IT applications, issues of project risk must be addressed, and the expectations of multiple stakeholders must be managed appropriately. To the extent that users and developers may harbour different perceptions regarding project risk, areas of conflict may arise. By understanding the differences in how users and project managers perceive the risks, insights can be gained that may help to ensure the successful delivery of systems. Prior research has focused on the project manager’s perspective of IT project risk. This paper explores the issue of IT project risk from the user perspective and compares it with risk perceptions of project managers. A Delphi study reveals that these two stakeholder groups have different perceptions of risk factors. Through comparison with a previous study on project manager risk perceptions, zones of concordance and discordance that must be reconciled are identified.
Identification of Cecidophyopsis mites (Acari: Eriophyidae) based on variable simple sequence repeats of ribosomal DNA internal transcribed spacer‐1 sequences via multiplex PCR
Authors: Lava Kumar P. , Fenton B. , Jones A. T.
Published: March 2003

A PCR multiplex technique was developed for identifying Cecidophyopsis mites using species‐specific differences in rDNA ITS‐1 sequences. Four PCR primers derived from ITS‐1 were used for the simultaneous amplification (multiplex PCR) of interspecifically variable simple sequence repeats (vSSRs). Mites were identified by electrophoresing PCR products alongside those obtained from plasmids containing ITS copies of known mite species. The multiplex PCR assay was rapid, reproducible and had a sensitivity comparable to sequencing. It was used to identify mite specimens on Ribes from around the world. It also identified a profile from mites on R. rubrum that had no equivalent amongst the known Cecidophyopsis species. Sequence and ecological analysis of this mite suggest that it is a new species of nongall‐forming Cecidophyopsis mite.
Chemical and gamma‐ray mutagenesis of the white gene in Aedes aegypti
Authors: Wendell M. D. , Wilson T. G. , Higgs S. , Black W. C.
Published: March 2003

A molecular understanding of an insect gene can be facilitated by analysing the phenotypes of mutants for that gene. Protocols were developed for both chemical and gamma‐ray mutagenesis in Aedes aegypti using the white (w) gene as an assay. Wild‐type adult males were subjected to varying doses of either ethyl methanesulphonate (0.1%, 0.5% or 1%) or gamma rays (1500 R or 3000 R), mated to females homozygous for the recessive w mutation, and progeny screened for the w phenotype, indicating non‐complementation. The expression of newly induced w alleles was either complete or mosaic. Gamma‐ray mutagenesis resulted in high (1.65 or 6.39%, depending on dose) induction of mutant alleles for the w gene, but not for a different gene, red‐eye (0.15%). Gamma‐ray‐induced w alleles did not revert at a reasonable frequency following additional irradiation, suggesting that the high rate of gamma‐ray‐induced w mutagenesis is not due to a transposon insertion event.
Analysis of intraspecies polymorphism in the ribosomal DNA cluster of the cockroach Blattella germanica
Authors: Mukha D. V. , Sidorenko A. P. , Lazebnaya I. V. , Wiegmann B. M. , Schal C.
Published: March 2003

HindIII restriction digests of the rDNA repeat unit of the German cockroach, Blattella germanica, reveal significant intraspecies sequence polymorphism. This variability is probably caused by structural differences within the nontranscribed spacer regions (NTS) of the ribosomal repeat unit. HindIII rDNA fragment polymorphisms in three cockroach strains show that individuals from different populations may have different HindIII rDNA patterns, whereas individuals within populations exhibit relatively similar rDNA patterns. We suggest that HindIII restriction fragment polymorphisms within cockroach ribosomal DNA will be a valuable tool for measuring population‐level parameters within and between natural cockroach populations.
Organization, evolution and expression of a multigene family encoding putative members of the odourant binding protein family in the medfly Ceratitis capitata
Authors: Christophides G. K. , Mintzas A. C. , Komitopoulou K.
Published: March 2003

A multigene family encoding male specific serum polypeptides (MSSPs) that show significant structural similarity to the family of insect odourant binding proteins, has been characterized in the medfly Ceratitis capitata. This family comprises seven members classified in three subgroups, MSSP‐α, MSSP‐β and MSSP‐γ. The genes of subgroups α and β are clustered in tandem in a 35‐kb genomic region, and present an exceptionally high degree of similarity not only in their coding but also in the surrounding regions, while the genes of the γ subgroup are drastically divergent. Although MSSPs are predominantly expressed in the male fat body, detailed expression studies suggest that individual members of this family are expressed in a distinct sex‐ and tissue‐specific manner.
Patterns of DNA sequence variation in chromosomally recognized taxa of Anopheles gambiae: evidence from rDNA and single‐copy loci
Authors: Mukabayire O. , Caridi J. , Wang X. , Touré Y. T. , Coluzzi M. , Besansky N. J.
Published: March 2003

Patterns of DNA sequence variation in the ribosomal DNA (rDNA) second internal transcribed spacer (ITS2) and five unlinked single‐copy nuclear loci were examined for evidence of reproductive isolation among four chromosomally recognized taxa of Anopheles gambiae from West Africa: Savanna, Bamako, Mopti and Forest, as well as sibling species An. arabiensis and An. merus. Included among the single‐copy loci were three sequence‐tagged random amplified polymorphic DNA (RAPD) loci, two of which (R15 and R37) had been reported as discriminating between Mopti and other chromosomal forms. Each of the five single‐copy sequences were highly polymorphic in most samples. However, the R15 and R37 loci had no diagnostic value, and therefore are not recommended as tools in recognition of field‐collected An. gambiae chromosomal forms. Although pairwise comparisons between species generally revealed significant levels of differentiation at all five loci, variation was not partitioned by chromosomal form within An. gambiae at any single‐copy locus examined. The few exceptions to these trends appear related to a location either inside or nearby chromosomal inversions. At the tryptophan oxygenase locus inside inversion 2Rb, variation was structured only by inversion orientation and not by taxonomic designation even between An. gambiae and An. arabiensis, providing the first molecular evidence that the 2Rb inversion was transferred between species by introgressive hybridization. By contrast, the rDNA showed fixed differences between species and a difference diagnostic for Mopti, consistent with effective, if not complete, reproductive isolation. The apparent disagreement between the data from this locus and multiple single‐copy loci within An. gambiae may be explained by the much lower effective population size of rDNA, owing to concerted evolution, which confers increased sensitivity at much shorter divergence times. Taken together with the accompanying reports by della Torre et al. (2001), Favia et al. (2001) and Gentile et al. (2001), our data suggest that neutral molecular markers may not have the sensitivity required to detect isolation between these recently established taxa.
The Drosophila gene Yippee reveals a novel family of putative zinc binding proteins highly conserved among eukaryotes
Authors: Roxström‐Lindquist K. , Faye I.
Published: March 2003

An intracellular Drosophila protein, Yippee, was identified in a yeast interaction trap screen as physically interacting with Hyalophora cecropia Hemolin. The Yippee gene was isolated, structurally characterized, and mapped to the region 12A on the X‐chromosome. Yippee contains a putative zinc‐finger‐like metal binding domain. It is the first characterized member of a conserved gene family of proteins present in diverse eukaryotic organisms, ranging from cellular slime mould to humans. A human cDNA clone was isolated and shown to be 76% identical to Drosophila Yippee. Yippee is ubiquitously expressed in different developmental stages of Drosophila and in different fetal tissues from human. Although the Hemolin–Yippee interaction remains to be further elucidated, the high degree of Yippee sequence conservation between a wide range of species suggests that this protein is of general importance in eukaryotes.
Developmental‐ and tissue‐specific expression of an inhibitor of apoptosis protein 1 homologue from Aedes triseriatus mosquitoes
Authors: Blitvich B. J. , Blair C. D. , Kempf B. J. , Hughes M. T. , Black W. C. , Mackie R. S. , Meredith C. T. , Beaty B. J. , Rayms‐Keller A.
Published: March 2003

We have identified a homologue of the Drosophila inhibitor of apoptosis protein 1 in Aedes triseriatus mosquitoes (designated AtIAP1). The AtIAP1 gene maps to a single locus on chromosome 2. The translation product is a 403 amino acid protein that contains two baculovirus IAP repeat (BIR) domains and a RING finger motif. AtIAP1 mRNA was detectable by RT‐PCR amplification in all the mosquito developmental stages (embryos, first–fourth instar larvae, early and late pupae, adults) and adult tissues (midguts, ovaries) examined. In contrast, immunoblots with AtIAP1‐specific antibodies revealed that the protein was detectable only in certain developmental stages (first instar larvae, early pupae, adults) and tissues (ovaries). AtIAP1‐specific serum also recognized proteins in Ae. aegypti, Ae. albopictus and Culex tritaeniorhynchus. Immunoblot analysis revealed that similar amounts of IAP1 were expressed in LaCrosse virus infected and uninfected Ae. albopictus cell cultures.
Molecular cloning and characterization of the cathepsin B‐like proteinase from the cotton boll worm, Helicoverpa armigera
Authors: Zhao X.‐F. , Wang J.‐X. , Xu X.‐L. , Schmid R. , Wieczorek H.
Published: March 2003

An enzyme purified from the ovaries of Helicoverpa armigera, as an active form with molecular mass of 30 kDa on SDS‐PAGE, was identified as a cysteine proteinase because it could be inhibited by E‐64, a specific inhibitor of cysteine proteinase, and required reducing conditions for activity. This enzyme was further identified as a cathepsin B‐like cysteine proteinase by partial amino acid sequencing. A cDNA encoding this proteinase was cloned from H. armigera, using degenerate primers and RACE techniques. Results of Northern blots indicated that the mRNA encoding the proteinase was transcribed in the ovaries, the fat bodies of female and male adults, pupae and in the larvae. No mRNA was detected from the larval epidermis or from the midgut. Hence, transcription of the cathepsin B‐like cysteine proteinase from H. armigera was tissue‐specific, but not gender‐ or developmental stage‐specific. However, proteolytic activities were only detected from ovaries, and adult female and male fat bodies. No activity was observed from pupal and larval fat bodies, from the larval epidermis or from the midgut. Only one form of mRNA of ≈ 1100 bases was detected, and in situ hybridization showed that the transcripts were distributed in the adult female fat bodies, follicular cells and the oocytes. Since the proteinase expressed in ovaries was able to degrade vitellin in vitro, it may be involved in the degradation of vitellin during embryonic development.
Prevalence of apical periodontitis and results of endodontic treatment in an adult, Portuguese population
Authors: Marques  , Moreira  , Eriksen
Published: March 2003

The present epidemiological study is derived from a random sample of 322 residents of the Porto area, aged 30–39 years. Prevalence of apical periodontitis and results of endodontic treatment were evaluated from orthopantomograms, available from 179 of a total of 197 individuals attending for examination. The results indicated a prevalence of apical periodontitis in 27% of this population. The quality of a majority (54%) of the 69 root fillings observed were found to be inadequate, (i.e. short and/or poorly condensed), but only 15 (22%) of the endodontically treated teeth presented with apical periodontitis.
Shaping ability of ProFile rotary nickel‐titanium instruments with ISO sized tips in simulated root canals: Part 2
Authors: Bryant  , Thompson  , Al‐Omari  , Dummer
Published: March 2003

The aim of this study was to determine the shaping ability of ProFile 0.04 taper rotary nickel‐titanium instruments with ISO sized tips in simulated canals. A total of 40 simulated root canals made up of four different shapes in terms of angle and position of curvature were prepared by ProFile instruments using the ‘crown down’ approach recommended by the manufacturer. Part 2 of this two‐part report describes the efficacy of the instruments in terms of prevalence of canal aberrations, the amount and direction of canal transportation and the overall post‐operative shape. Out of 37 completed specimens 9 zips (24%) and one ledge (3%) were created, but no perforations or danger zones were found. There were significant differences (P < 0.01) between canal shapes for the incidence of zips and elbows but not for their distance from the end‐point of preparation. At specific positions along the canal length there were significant differences between the canal types in terms of their mean total width; overall, at the end‐point of preparation and along the curved portion of the canals those specimens with 40° curves were widest. This trend continued for the width of material removed from the outer aspect of the canal curves, whereas along the inner aspect of curves more material was removed in the 20° canals. Overall, transportation was towards the outer aspect of the curve at the end‐point of preparation and along the curved portion of canals but more balanced along the straight coronal section. Absolute transportation was small and below 0.1 mm at every position including the zips. Under the conditions of this study, ProFile nickel‐titanium rotary instruments with ISO sized tips produced a larger number of zips than expected; however, the degree of zipping was limited and relatively minor.
A comparison of MTA, Super‐EBA, composite and amalgam as root‐end filling materials using a bacterial microleakage model
Authors: Adamo H. L. , Buruiana R. , Schertzer L. , Boylan R. J.
Published: March 2003

Aim The aim of this study was to compare traditional and newly developed root‐end filling materials for resistance to bacterial microleakage.

Methodology Sixty extracted single‐rooted teeth were randomly divided into five groups for root‐end filling with mineral trioxide aggregate, Super‐EBA, TPH composite resin with ProBond dentine bonding agent, Dispersalloy amalgam with and without ProBond, and positive and negative control groups. Root canals were instrumented using the step‐back technique and simulated root‐end resections performed. Root‐end filling materials were placed in 3 mm ultrasonic retropreparations. Nail varnish was applied to all external root surfaces to the level of the resected root ends to prevent lateral microleakage. Samples were sterilized in an ethylene oxide sterilizer for 12 h. Using a newlydesigned model system, the apical 3–4 mm of the roots were immersed in BHI culture medium with phenol red indicator within culture chambers. The coronal access of each specimen was inoculated every 48 h with a suspension of Streptococcus salivarius. Culture media were observed every 24 h for colour change indicating bacterial contamination. Media demonstrating colour change were plated for S. salivarius. Samples were observed for 12 weeks.

Results At 4 weeks 10% of specimens from each experimental group had evidence of leakage. At 8 weeks 20% of specimens filled with amalgam without dentine bonding agent, Super‐EBA and MTA had evidence of leakage. At 12 weeks minor differences between materials were noted.

Conclusions Under the conditions of the study, despite some variations, there were no statistically significant differences in rate of microleakage among the five groups tested at either 4, 8 or 12 weeks.
A case of an odontogenic cutaneous sinus tract
Authors: Nakamura Y. , Hirayama K. , Hossain M. , Matsumoto K.
Published: March 2003

Case report A 22‐year‐old female presented with a draining sinus tract on her left cheek. The tooth responsible was examined clinicopathologically. On clinical examination, the mandibular left first molar tooth was restored with an amalgam filling. Radiographic examination revealed base or pulp capping material below the restoration and a radiolucent periapical lesionsurrounding the distal root apex. Conservative non‐surgical root canal treatment was performed; 10 months later, the sinus had healed completely and the periapical lesion had resolved. Histopathological examination of pulp tissue recovered during treatment revealed foreign bodies, made up of capping material and amalgam, associated with chronic inflammation. These findings suggested that chronic inflammation in the pulp tissue had resulted in a draining sinus tract.
Assessment of apical and coronal root canal seals using contemporary endodontic obturation and restorative materials and techniques
Authors: Davalou S. , Gutmann J. L. , Nunn M. H.
Published: March 2003

Aim The purpose of this study was to evaluate the sealing ability of two contemporary endodontic obturation and restorative techniques and materials.

Methodology Seventy‐nine extracted human single‐rooted teeth were distributed randomly in two experimental groups of 36 and 37 specimens (groups 1 and 2, respectively), one group of three positive controls and one of three negative controls. The teeth were radiographed preoperatively, accessed, and instrumented. After smear layer removal, the teeth in group 1 were obturated using the System B and Obtura and were restored coronally with Core Paste using Tenure as a bonding agent. The teeth in group 2 were obturated using the Microseal technique and were restored coronally with amalgam using Panavia 21 as a bonding agent. All teeth in groups 1 and 2 were coated with three layers of nail varnish on all of their surfaces apart from the apical 4.0 mm and the coronalarea above the cemento‐enamel junction. The positive control teeth were obturated, restored coronally and completely coated with varnish, whereas the negative control teeth were not obturated, restored coronally, nor coated with varnish. The teeth were radiographed postoperatively and retained in saline solution for 10 days. For the next 10 days they were submerged in India ink. Subsequently all teeth were demineralized, dehydrated and rendered transparent. Dye penetration was measured using a stereomicroscope.

Results All materials and techniques provided minimal to zero dye penetration, apart from one specimen in the Core Paste group that showed 4.0 mm of dye penetration. The Wilcoxon rank sum test and t‐test showed no statistically significant differences and all materials and techniques tested presented with a high degree of acceptability.

Conclusions It was concluded that these contemporary techniques and materials provide equally good results, but long‐term studies are needed for outright inferences to be drawn relative to their clinical performance.
Comparative radiopacity of tetracalcium phosphate and other root‐end filling materials
Authors: Laghios C. D. , Benson B. W. , Gutmann J. L. , Cutler C. W.
Published: March 2003

Aim

This study compared the radiopacity of tetracalcium phosphate (TTCP) and 11 root‐end filling materials relative to human dentine.

Methodology

Specimens of 2 mm thickness and a graduated aluminium stepwedge were placed on dental X‐ray films and exposed to an X‐ray beam. The optical densities of the specimens and aluminium steps were measured. The optical densities of the specimens were correlated to the equivalent thickness of aluminium with a regression analysis equation. The equation was used to calculate the equivalent aluminium thickness of each of the specimens.

Results

Nine of the materials were found to be of acceptable radiopacity (at least 2 mm Al more radiopaque than dentine). TCCP and two of the glass‐ionomer compounds were found to have insufficient radiopacity to be radiographically distinguishable from human dentine.

Conclusions

All the materials were found to be distinguishable radiographically from dentine, except for Vitrebond, TTCP and Ketac‐Fil. Amalgam was the most radiopaque material and Ketac‐Fil was the least radiopaque material tested.
Canal shapes produced sequentially during instrumentation with Quantec SC rotary nickel–titanium instruments: a study in simulated canals
Authors: Griffiths I. T. , Chassot A. L. , Nascimento M. F. , Bryant S. T. , Dummer P. M. H.
Published: March 2003

Aim

The aim of this study was to determine the shaping ability of Quantec SC nickel–titanium rotary instruments in simulated root canals.

Methodology

Forty simulated canals consisting of four different shapes in terms of angle and position of curvature were prepared with Quantec SC instruments. Sequential still images were taken of the canals using a video camera attached to a computer with image analysis software. Images were taken preoperatively, and then after instrument 7 (Size 25, 0.05 taper), instrument 8 (size 25, 0.06 taper), and instrument 10 (size 45, 0.02 taper) were taken to length. Each sequential postoperative image was superimposed individually over the preoperative image in order to highlight the amount and position of material removed during preparation.

Results

Overall, the mean preparation time to size 10 was 3.6 min with 12 mm canals taking on average less time than 8 mm canals. There was a highly significant difference between the canal types (P < 0.0001). No instruments fractured within the canal or deformed, although one instrument separated from the latch grip. All canals remained patent. Following preparation to size 10, 19 canals (48%) retained their length, eight (20%) lost length, and 13 (32%) gained length; the magnitude of the change in length was always 0.5 mm or below. Following preparation to size 7 instruments all canals showed aberrant shapes. Excess removal of material along the outer aspect of the curve between the beginning of the curve and the end‐point (outer widening) was found in 26 canals (65%) after instrument 7. At the same stage of preparation six canals (15%) had zips, three (8%) had ledges and five (13%) had perforations. Following preparation to size 10, 27 (68%) canals were perforated.

Conclusions

Under the conditions of the study, Quantec SC instruments consistently produced aberrations when canals were enlarged to size 7 (size 25, 0.05 taper) or above. Care should be exercised when using these instruments in real teeth.
Control of microorganisms in vitro by calcium hydroxide pastes
Authors: Estrela C. , Bammann L. L. , Pimenta F. C. , Pécora J. D.
Published: March 2003

Aim

The aim of this study was to determine the influence of vehicles on the antimicrobial efficiency of calcium hydroxide.

Methodology

A total of 588 size 50 sterile absorbent paper points, were immersed in various microbial suspensions for 3 min. The points were then placed on Petri dishes and covered with intracanal dressings containing calcium hydroxide: Ca(OH)2 + saline; Ca(OH)2+ camphorated paramonochlorophenol; Ca(OH)2 + 1% chlorhexidine solution; Ca(OH)2 + 3% sodium lauryl sulphate; Ca(OH)2 + Otosporin®. After 1 min, 48 and 72 h and 7 days, 147 absorbent paper cones were removed from contact with the intracanal dressings and individually transported and immersed in 5 mL of Letheen Broth, followed by incubation at 37 °C for 48 h. Microbial growth was evaluated by turbidity of the culture medium. A 0.1‐mL inoculum obtained from the Letheen Broth was transferred to 5 mL of BHI, and incubated at 37 °C for 48 h. Bacterial growth was again evaluated by turbidity of the culture medium. Positive BHI tubes were selected and inocula were spread on the surface of BHI agar and incubated at 37 °C for 48 h. Gram staining of the BHI growth and from colonies growing on BHI agar was carried out.

Results

An antimicrobial effect occurred after 48 h on the cultures of S. mutans, E. faecalis, S. aureus, P. aeruginosa, B. subtilis, C. albicans and a mixed culture, irrespective of the intracanal dressing.

Conclusions

Under the conditions of this study, the various vehicles associated with calcium hydroxide pastes did not influence the time required for microbial inactivation.
Bacteria on the apical root surfaces of untreated teeth with periradicular lesions: a scanning electron microscopy study
Authors: Siqueira J. F. , Lopes H. P.
Published: March 2003

Aim The purpose of this study was to examine the presence of bacteria on the apical root surfaces of untreated teeth associated with chronic periradicular lesions.

Methodology  Twenty‐seven extracted teeth with extensive carious lesions, radiolucent lesions of varying sizes and attached periradicular lesions after extraction, were selected for study. Following fixation, lesions were removed and the apical 5‐mm portion of each root was sectioned. Root tips were dehydrated, sputter‐coated with gold, and then examined for the occurrence of bacteria on the apical root surfaces using a scanning electron microscope.

Results Bacterial cells were usually observed close to the apical foramen, but restricted to the root canal. Morphologically, these bacteria consisted of cocci and rods. A dense bacterial aggregate composed mainly of rods was observed within the root canal and surrounding the apical foramen of one specimen. Beyond the apical foramen, other bacterial morphological types were recognized, including coaggregations of cocci and filaments, characterizing a fully developed ‘corn cob’.

Conclusions Extraradicular bacteria were observed in one tooth out of 27 (4% of the cases).
Isolation of yeasts and enteric bacteria in root‐filled teeth with chronic apical periodontitis
Authors: Peciuliene V. , Reynaud A. H. , Balciuniene I. , Haapasalo M.
Published: March 2003

Aims

The aim of this study was to determine the occurrence and role of yeasts, enteric gram‐negative rods and Enterococcus species in root‐filled teeth with chronic apical periodontitis, and the antimicrobial effect of iodine potassium iodide (IKI) irrigation.

Methodology

Forty symptom‐free root‐filled teeth with chronic apical periodontitis were included in the study. The patients were divided into two groups. In group A the canals were filled with calcium hydroxide for 10–14 days after cleaning and shaping; in group B the canals were irrigated with IKI for 5 min after cleaning and shaping followed by a permanent root filling. Microbiological samples were taken from the canals before and after the chemomechanical preparation and after iodine irrigation (group B).

Results

Microbes were isolated from 33 of 40 teeth in the initial sampling. Yeasts were isolated from six teeth, three of them together with E. faecalis. Enteric rods (Escherichia coli, Klebsiella pneumoniae and Proteus mirabilis) were present in three teeth and E. faecalis was isolated from 21 of the 33 culture positive teeth, 11 in pure culture. Growth was detected in 10 teeth of the second samples. Six of the 10 cases were E. faecalis, with five being a pure culture. All third samples (after IKI) except one were negative. The number of microbial cells per sample did not correlate with lesion size. Two flare‐ups were recorded, both in teeth with a mixed infection.

Conclusion

The high prevalence of enteric bacteria and yeasts in root‐filled teeth with chronic apical periodontitis was established. IKI improved the antimicrobial effect of the treatment.
Curved molar root canal preparations using Hero 642 rotary nickel–titanium instruments
Authors: Bertrand M‐F. , Lupi‐Pégurier L. , Médioni E. , Muller M. , Bolla M.
Published: March 2003

Aim

The Bramante method was used to study how the natural curvature of root canals was modified when using the Hero 642 nickel–titanium rotary system.

Methodology

Twenty‐four canals were selected in freshly extracted human mandibular molars. Every root canal had an angle of curvature greater than 20°. Roots were embedded in clear casting resin using a plaster mould. Cross‐sectional cuts were made in the apical, middle and coronal thirds of each root. A first group (control) of 12 curved root canals was prepared using stainless steel hand instruments and the step‐back technique. A second group of 12 curved root canals was instrumented using the Hero sequence according to the manufacturer's instructions. For each sectioning level, the amount of dentine removed, the change of shape factor and the canal centre displacement were calculated with the aid of a digital image analysis system. The results were subjected to the Mann–Whitney U‐test.

Results

No significant difference occurred in the amount of dentine removed, change of shape factor or canal centre displacement in the coronal and middle thirds of the curved canals. In the apical third, transportation was significantly higher (P = 0.0171) with stainless steel hand instruments than with the Hero system.

Conclusions

The original canal shape was maintained better in the apical third of curved canals when using the Hero system in a crown‐down technique when compared to a hand preparation technique with stainless steel instruments.
Marmoset spermatogenesis: organizational similarities to the human
Authors: Millar Michael R. , Sharpe Richard M. , Weinbauer Gerhard F. , Fraser Hamish M. , Saunders Philippa T. K.
Published: March 2003

The common marmoset (Callithrix jacchus), a small New World primate of high fecundity, is widely used in reproductive research. The aim of the present study was to determine the organization of the germ cells within the seminiferous epithelium, the duration of the spermatogenic cycle and the number of spermatogonial mitoses. Antibodies to cAMP response element modulator (CREM) and proliferating nuclear cell antigen (PCNA) and a cRNA directed against protamine P2 and morphological criteria were used to discriminate between stages of the spermatogenic cycle. Plastic sections were used to document the cell associations present in each of the nine stages of spermatogenesis. Up to five such stages could be observed within individual cross‐sections of seminiferous tubules. Based on the pattern of incorporation of bromodeoxyuridine the length of the spermatogenic cycle was estimated to be 10 days and the duration of spermatogenesis to be 37 days. Four mitotic divisions were noted in spermatogonia. It is concluded that the organization of spermatogenesis in the marmoset has similarities to the human (‘helical’) and this makes the marmoset a suitable model for studies relevant to human testicular function.
Present and future therapeutic strategies for idiopathic oligozoospermia
Authors: Adamopoulos Dimitrios A.
Published: March 2003

The effectiveness of medical treatment for idiopathic oligozoospermia (IO) has been at best doubtful until now and a logical consequence of this unsatisfactory situation has been the partial displacement of this approach by assisted reproduction techniques. This state of affairs has resulted from insufficient investigation, inappropriately designed clinical trials and consistent disregard for the principles of evidence‐based medicine. Protocol‐related shortcomings and wrong interpretation of the data available have also been some of the all too frequent problems encountered in this therapeutic approach. In this rather misty situation, it appears that, of the therapeutic agents used so far, follicle stimulating hormone (FSH) (mainly FSH‐secretagogues) may exert some beneficial effects on a number of biological endpoints related to spermatogenesis and sperm maturation. The short and medium term prospects of medical treatment for IO rest mainly with improvement of investigative procedures to a higher degree of sophistication, with emphasis placed on identifying the causes rather than the results of dysfunction so that a better selection of candidates can be made. Moreover, the introduction of prognostic indices for evaluation of the beneficial effects of a therapeutic agent may be of paramount importance. Finally, a better assessment of the preparations available and, possibly, the introduction of new more specific agents may also be an important step forward in this field. This type of large‐scale effort should not be left to individual investigators or special centres working independently, but it may come under the auspices of a central regulating agency so that undisputed results from large, multicentre and uniform studies might be obtained, if medical treatment is to remain a good option. In this context, it may also be emphasized that andrology's main task should always be to treat the male with the problem rather than his healthy female partner, whenever this is possible.
Activity of testis angiotensin converting enzyme (ACE) in ejaculated human spermatozoa
Authors: Shibahara H. , Kamata M. , Hu J. , Nakagawa H. , Obara H. , Kondoh N. , Shima H. , Sato I.
Published: March 2003

Testicular angiotensin converting enzyme (ACE) isozyme is likely to play important functional roles in male reproduction. Several studies have shown that ACE is released from human spermatozoa during capacitation and that ACE is associated with reduced sperm motility. Recently, we established an assay to detect testicular ACE activity in human spermatozoa. The purpose of this study was to determine if testicular ACE activity is related to sperm motility in human ejaculates. Semen samples were collected from 80 infertile patients. According to the semen characteristics, they were divided into four (WHO) categories. Enzyme activities of ACE in spermatozoa (testicular ACE) and seminal plasma (somatic ACE) were spectrophotometrically determined. Total testicular ACE activity in spermatozoa was measured by solubilization of spermatozoa with Triton X‐100. Membrane testicular ACE activity was measured in a sperm : PBS suspension. Sperm concentration and sperm motility were 136.6 ± 154.1 × 106/mL and 58.6 ± 23.4%, respectively (mean ± SD). Enzyme activities of membrane testicular ACE, total testicular ACE and somatic ACE were 0.273 ± 1.219 μU/106 spermatozoa, 0.35 ± 1.34 μU/106 spermatozoa and 684.7 ± 226.6 mU/mL, respectively. A negative correlation was observed between sperm motility and membrane testicular ACE activity (p < 0.05). Membrane testicular ACE activity in 44 normal semen samples was 0.04 ± 0.02 μU/106 spermatozoa, whilst that in 36 abnormal semen samples was 0.24 ± 0.42 μU/106 spermatozoa. There was a significant difference between these two groups (p < 0.01). Membrane testicular ACE in sperm samples from normozoospermic men was significantly lower than that from oligoasthenozoospermic men (p < 0.05). These findings suggest that testicular ACE is released from normal functional spermatozoa for them to have fertilizing ability.
Evaluation of the acrosome reaction and viability in buffalo spermatozoa using two staining methods: the effects of heparin and calcium ionophore A23187
Authors: Kitiyanant Y. , Chaisalee B. , Pavasuthipaisit K.
Published: March 2003

In this study, we investigated the effect of heparin and calcium ionophore A23187 on in vitro induction of buffalo sperm acrosome reaction (AR). Two methods for detection of the AR and viability were employed. Fluorescein isothiocyanate‐conjugated Arachis hypogea agglutinin (FITC‐PNA) was used as a vital stain in combination with ethidium homodimer‐1 (EthD‐1) to determine the acrosome status of viable spermatozoa. In another experiment, trypan blue replaced EthD‐1 to differentiate live and dead spermatozoa having undergone AR. The results from the two methods were significantly correlated (r > 0.9). Four different staining patterns were found in both methods. The FITC‐PNA intensely labels the acrosome region of acrosome‐intact spermatozoa. EthD‐1 and trypan blue stained red and blue at the post‐acrosomal region of dead spermatozoa, respectively. Spermatozoa incubated with heparin showed a significant increase ( p < 0.05) in the percentage of live acrosome‐reacted sperm after 30 min incubation period. This trend continued and was significantly different over the entire incubation period when compared with the control group at the same interval. In the ionophore‐treated group, the proportion of changes in live acrosome‐intact and live acrosome‐reacted spermatozoa was statistically significantly different ( p < 0.001) when compared with those treated with heparin at the same interval. The AR occurred sooner and to a greater extent when incubated with the ionophore but at 5 h of incubation the percentage of false acrosomal reaction was significantly higher than those in the control and heparin‐treated groups. The results in this study indicated that the in vitro induction of AR by heparin and calcium ionophore evaluated by both methods could be used to assess sperm fertilizing capacity for in vitro fertilization of this species.
Sperm morphology analysis using strict criteria as a prognostic factor in intrauterine insemination
Authors: Lee Robert Kuo‐Kuang , Hou Jen‐Wan , Ho Hsin‐Yi , Hwu Yuh‐Ming , Lin Ming‐Huei , Tsai Yi‐Chun , Su Jin‐Tsung
Published: March 2003

The objective of this study was to investigate the predictive value of Kruger's criteria for sperm morphology on intrauterine insemination (IUI) outcome. A total of 209 infertile patients underwent 244 IUI treatment cycles. These include 75 couples (80 cycles) with teratozoospermia and 134 couples (164 cycles) with unexplained infertility. The pregnancy rates per IUI cycle were 3.8 (1/26), 18.5 (10/54) and 29.9% (49/164) in patients with sperm morphology with <4, 4–9 and >9% normal forms, respectively, according to Kruger's criteria. A statistical difference in outcome was seen between couples with <4 and >9% normal forms (p = 0.005). Although the difference in pregnancy rates between those with 4–9 and <4% normal forms was not statistically significant, the pregnancy rate for those with 4–9% normal forms was acceptable and still higher than in those with <4% normal forms. Therefore, we suggest that IUI is a reasonable first‐line therapy for patients with sperm morphology >4% normal forms, while couples with <4% normal forms should be advised to use in vitro fertilization with intracytoplasmic sperm injection instead of IUI.
The association between murine cytomegalovirus induced hepatitis and the accummulation of oval cells
Authors: Cassell Heidi S. , Price Patricia , Olver Stuart D. , Yeoh George C. T.
Published: March 2003

The accumulation of oval cells is an early event in the development of hepatocellular carcinoma induced by certain experimental regimes involving hepatocarcinogens. Oval cells have also been observed during chronic hepatitis induced by alcohol and iron overload. In this study, livers of murine cytomegalovirus (MCMV) infected mice were examined to determine whether hepatitis induced by this virus could initiate oval cell proliferation. BALB/c and C57BL/6 mice were infected with MCMV and studied 4, 8, 10 and 12 months later, alongside control (uninfected) mice. The livers were examined histochemically, immunocytochemically and by in situ hybridization to identify oval cells, inflammatory cells and proliferating cells. Oval cells were seen in the periportal regions of livers from MCMV infected BALB/c mice. These increased in number from 4 to 12 months after infection in parallel with increases in the numbers of inflammatory cells, even though cells expressing MCMV antigens were no longer evident in these samples. Proliferating oval cells and hepatocytes were identified by PCNA staining, indicating an increased level of liver regeneration in the infected livers. C57BL/6 mice are less susceptible to persistent MCMV hepatitis and had fewer oval cells than BALB/c mice. Thus the study demonstrates an association between MCMV induced hepatitis, inflammation, and presence of oval cells.
Influence of host microvascular environment on tumour vascular endothelium
Authors: KUBITZA MARION , HICKEY LUCAS , GREGORY ROBERTS
Published: March 2003

This review will focus on the tumour microvascular endothelium; how it is derived, modulated by angiogenic factors, and how the structure and function is influenced by the host tissue microenvironment.
Effects of vitamin E on human platelet and mononuclear cell responses in vitro
Authors: Williams J.C. , Forster L.A. , Tull S.P. , Ferns G.A.A.
Published: March 2003

Recent epidemiological studies have provided evidence supporting the potential benefits of antioxidants in coronary prevention. We have investigated the effects of vitamin E on platelets, monocytes and endothelial cells in vitro. Pre‐incubation of platelets with vitamin E inhibited subsequent thrombin‐ (P < 0.05, n = 5), collagen‐ (P < 0.0001, n = 5) and ADP‐(P < 0.05, n = 4) induced platelet aggregation measured using a microtitre plate method, or conventional aggregometry. The adhesion of thrombin‐activated platelets to collagen was also inhibited by vitamin E (P < 0.05, n = 8), but not by vitamin C (P > 0.05, n = 8); nor was the adhesion of unstimulated platelets significantly affected (P > 0.05, n = 8). Pre‐incubation of monocytes with vitamin E inhibited their subsequent adhesion to plastic (P < 0.05, n = 9), and was also associated with an 18% reduction in adhesion to EA.hy 926 endothelial cells (n = 8), although this failed to reach statistical significance. Pre‐incubation of the endothelial cells with vitamin E also significantly reduced subsequent mononuclear cell adhesion by 56% (P < 0.05, n = 3).
Changing myoepithelial cell distribution during regeneration of rat parotid glands.
Authors: Takahashi Shigeru , Nakamura Shiro , Suzuki Reiko , Domon Takanori , Yamamoto Tsuneyuki , Wakita Minoru
Published: March 2003

The distribution of the myoepithelial cells during regeneration of the rat parotid gland after atrophy induced by one week of parotid duct ligation was investigated by immunohistochemistry for actin and transmission electron microscopy (TEM). Immunohistochemically, residual ducts were surrounded by actin‐positive cells when clips were removed from the duct. Three days later, most of the newly formed acini originating from the residual ducts were also embraced by actin‐positive cells. After 10 days, actin‐positivity tended to be seen as dots around acini that decreased in number day by day. On day 21 actin‐positive cells mainly surrounded intercalated ducts with only a few positive reactions identified at the acinar periphery. Electron microscopically, residual ducts and newly formed acini were peripherally embraced by myoepithelial cells before day 5. After day 7, shift of myoepithelial cells from the periphery of acini to the duct‐acinar junctional region was identified. Then few myoepithelial cells were identified at the periphery of acini. These observations indicate that myoepithelial cells migrate from the acinar periphery to the duct‐acinar junctional region during rat parotid regeneration, and that such behaviour is closely related to that seen during rat parotid development.
Experimental cerebral aneurysms in the female heterozygous Blotchy mouse
Authors: Coutard Michèle
Published: March 2003

The Blotchy mouse is characterized by an X‐linked inherited disorder of connective tissue synthesis. The susceptibility to aneurysm formation in the cerebral arteries of the circle of Willis was compared in female heterozygous ‘Blotchy’ and control mice subjected to unilateral carotid artery ligation either alone or associated with hypertension. Cerebral aneurysms developed only in hypertensive Blotchy mice (6/31 vs. 0/30 in hypertensive controls). Aneurysms of the aorta and its major branches occurred in normotensive mice only in the Blotchy group in which hypertension increased the incidence of mesenteric and coeliac aneurysms. A light microscopic study of interruptions of the internal elastic lamina (IIEL) showed that they developed in arteries of both Blotchy and control mice but to a greater extent in the Blotchy group where hypertension further increased their incidence. The IIEL incidence in the aortic arch varied in parallel to the occurrence of aneurysms in all the different arterial sites. Thus, in an apparently normally viable animal, the presence of a mutated gene which indirectly leads to defective elastin and collagen fibre synthesis, favours the formation of both peripheral and cerebral aneurysms. However, the development of cerebral aneurysms requires the addition of an increase in haemodynamic stress.
Evidence for a perforin‐mediated mechanism controlling cardiac inflammation in Trypanosoma cruzi infection
Authors: HENRIQUES‐PONS ANDREA , OLIVEIRA GABRIEL M. , PAIVA MAURICIO M. , CORREA ALEXANDRE F. S. , BATISTA MARCOS M. , BISAGGIO RODRIGO C. , LIU CHAU‐CHING , COTTA‐DE‐ALMEIDA VINÍCIUS , COUTINHO CLAUDIA M. L. M. , PERSECHINI PEDRO M. , ARAÚJO‐JORGE TANIA C.
Published: March 2003

Summary.  CD8+ T lymphocytes are considered an important cell population involved in the control of parasitaemia and mortality after Trypanosoma cruzi infection. However, despite recent developments in this field, the mechanism whereby this control is exerted is still not completely understood. Here we have used perforin knockout (–/–) mice infected with Y strain T. cruzi in order to evaluate specifically the participation of the perforin‐based cytotoxic pathway in the destruction of cardiomyocytes, cellular inflammatory infiltration, and control of parasitaemia and mortality. We observed that although parasitaemia was equivalent in perforin (+/+) and (–/–) groups, survival rate and spontaneous physical performance were significantly lower in the perforin deficient mice. The cardiac inflammatory cell infiltration, mostly composed of CD8+ cells, was more evident in perforin (–/–) mice. Ultrastructural and immunofluorescence analysis, as well as plasma creatine kinase activity, revealed cardiomyocyte damage and necrosis, more evident in perforin (–/–) mice. Terminal deoxynucleotidyl transferase‐mediated dUTP nick end labelling (TUNEL) assays performed in heart samples revealed similar and modest levels of apoptosis in both perforin (+/+) and (–/–) mice. These results indicate that perforin does not play a pivotal role in the control of parasitaemia and direct lysis of cardiomyocytes, but seems to be an important molecule involved in the control of cardiac inflammation and pathology induced by a highly virulent strain of T. cruzi.