bluuebunny/crossref_metadata_2025 huggingface dataset:
Analysing four types of IT sourcing decisions in the context of scale, client/supplier interdependency and risk mitigation
Authors: Currie W. L. , Willcocks L. P.
Published: March 2003

The main thrust of the article is to distinguish between four types of IT sourcing decision: total outsourcing; multiple‐supplier sourcing; joint venture/strategic alliance sourcing; and insourcing. To illustrate each type, detailed case histories are used that analyse the reasons why specific IT sourcing decisions were adopted. Here, we consider total outsourcing at the London Stock Exchange; multiple‐supplier sourcing at ICI plc; joint venture project sourcing at CRESTCo Ltd; and insourcing at the Royal Bank of Scotland. The trend towards outsourcing is increasing in all industrial and commercial sectors. However, client organizations need to become more aware of some of the pitfalls, particularly in respect of large‐scale outsourcing deals to single or multiple suppliers. This is because the move to IT outsourcing engenders the need to develop new capabilities and skills to manage complex commercial contracts. We therefore conclude that, while many IT outsourcing contracts followed rationalization, cost‐cutting and disappointing results from in‐house IT provision, short‐termism and current uncertainties over market, business and political conditions pose problems for many organizations in deciding future outsourcing arrangements.
Constructing a web information system development methodology
Authors: Vidgen Richard
Published: March 2003

Abstract. This paper reports on the extension of the Multiview framework to web‐based information systems. The aims are firstly to investigate the appropriateness of Multiview – a pre‐Internet analysis and design methodology – to web‐based information systems and, secondly, to reflect on the nature and role of methodology, as distinct from method, in the information systems (IS) development process. A 2‐year e‐commerce development project in a small to medium enterprise is the setting for learning through action research. To distinguish the project from consultancy, a framework of ideas – Multiview – is declared and tested in the research process. The differences and similarities of pre‐Internet and Internet‐based projects are analysed and reported on. At a higher order of learning the project provided an opportunity to reflect on how methodologies are constructed in practice.
Towards a framework for evaluating investments in data warehousing
Authors: Counihan Ailish , Finnegan Pat , Sammon David
Published: March 2003

Data warehousing technology offers organizations the potential for much greater exploitation of informational assets. However, the evaluation of potential investments in this technology poses problems for organizations as traditional evaluation methods are constrained when dealing with strategic IT applications. Nevertheless, many organizations are procedurally obliged to use such methods for evaluating data warehousing investments. This paper identifies five problems with using such methods in these circumstances: evaluating intangible benefits; making the relationship between IT and profitability explicit; dealing with the vanishing status quo; dealing with the extended investment time frame; and evaluating infrastructural investments. The authors studied how four organizations in the UK and Ireland attempted to overcome these problems when introducing data warehousing, and propose a framework for evaluating data warehousing investments. This framework consists of a high‐level analysis of the economic environment and of the information intensity of the relationship between the organization and its customers. Based on the outcome of this analysis, the authors propose four factors that have to be managed during the evaluation process in order to ensure that the limitations of the traditional evaluation techniques do not adversely affect the evaluation process. These factors are: commitment and sponsorship; the approach to evaluation; the time scale of benefits; and the appraisal techniques used.
Dissecting insect development: baculovirus‐mediated gene silencing in insects
Authors: Hajós J. P. , Vermunt A. M. W. , Zuidema D. , Kulcsár P. , Varjas L. , De Kort C. A. D. , Závodszky P. , Vlak J. M.
Published: March 2003

A novel concept applying baculovirus‐mediated gene silencing to study insect gene function and regulation is described in this paper. A recombinant baculovirus, Autographa californica multicapsid nucleopolyhedrovirus (AcMNPV), was constructed with the juvenile hormone esterase (JHE) gene from the tobacco budworm Heliothis virescens in the antisense orientation, driven by the viral p10 promoter. Infection with this recombinant greatly reduced the haemolymph JHE level and resulted in aberrant morphogenesis of final‐instar H. virescens larvae. The body organization remained larval, although the cuticle became hard and brown, similar to pupal cuticle. These results demonstrated that baculovirus‐mediated gene silencing can be accomplished and utilized to dissect insect development and to design a new class of baculovirus insecticides.
Molecular characterization of a peroxiredoxin from the hard tickHaemaphysalis longicornis
Authors: Tsuji N. , Kamio T. , Isobe T. , Fujisaki K.
Published: March 2003

Antioxidant enzymes in eukaryotes play an important role in protection against the oxygen radicals generated during aerobic metabolism. Here we report the cloning and characterization of a cDNA encoding the antioxidant enzyme peroxiredoxin from the hard tickHaemaphysalis longicornis(HlPrx). HlPrx is 939 bp long and contains a 101 bp non‐translated sequence at the 5′ end and a polyadenylation singnal followed by a poly(A) tail at the 3′ end. HlPrx encodes a full‐length protein with a predicted molecular mass of 26 kDa that possesses one cysteine residue at amino acid 49 that is conserved among Prx proteins of various species. GenBank™ analysis showed that the deduced amino acid sequence had significant similarity to mammalian and plant Prxs at the amino acid level. A DNA‐nicking assay revealed thatEscherichia coli–expressed recombinant HlPrx (rHlPrx) inhibited oxidative‐nicking of supercoiled plasmid DNA. Two‐dimensional immunoblot analysis with mouse antirHlPrx serum showed reaction with a major constituent protein spot in extracts of adult ticks. In addition, immunoblot analysis showed that rHlPrx was immunoreacted with serum from rabbits repeatedly infested withH. longicornis. Localization analysis using mouse antirHlPrx serum revealed that native HlPrx was highly expressed in the salivary gland of the tick. Moreover, Northern blot analysis showed that the level of HlPrx transcripts was increased during blood sucking. The present results indicate that HlPrx may be an important detoxifying enzyme during the normal life span as well as during blood sucking in ticks.
Transgene expression from the Tribolium castaneum Polyubiquitin promoter
Authors: Lorenzen M. D. , Brown S. J. , Denell R. E. , Beeman R. W.
Published: March 2003

The highly conserved Ubiquitin proteins are expressed from genes with strong, constitutively active promoters in many species, making these promoters attractive candidates for use in driving transgene expression. Here we report the cloning and characterization of the Tribolium castaneum Polyubiquitin (TcPUb) gene. We placed the TcPUb promoter upstream of the coding region of the T. castaneum eye‐colour gene Tc vermilion (Tcv) and injected this construct into embryos from a Tcv‐deficient strain. Transient expression of Tcv during embryogenesis resulted in complete rescue of the larval mutant phenotype. We then incorporated the TcPUb‐Tcv chimera into a piggyBac donor. Resulting germline transformants were easily recognized by rescue of eye pigmentation, illustrating the potential of the TcPUb promoter for use in driving transgene expression.
Antibacterial peptide defensin is involved in midgut immunity of the soft tick, Ornithodoros moubata
Authors: Nakajima Y. , Van Der Goes van Naters‐Yasui A. , Taylor D. , Yamakawa M.
Published: March 2003

Two defensin genes A and B were previously demonstrated to be up‐regulated by blood feeding in the soft tick, Ornithodoros moubata[Nakajima et al. (2001) Two isoforms of a member of the arthropod defensin family from the soft tick, Ornithodoros moubata (Acari: Argasidae). Insect Biochem Mol Biol 31: 747–751]. In this study, two defensin isoforms C and D similar to defensins A and B were newly cloned. A total of four defensins have been identified in O. moubata. All four Ornithodoros defensins are coded as prepro‐defensins. Ornithodoros defensin genes consist of four exons and three introns, an organization reported in mussel defensins but not insect defensins. Ornithodoros defensin C and D genes are predominantly expressed in the midgut and up‐regulated in response to blood feeding. The mature peptide of the previously cloned Ornithodoros defensin A was purified from the midgut lumen, indicating defensin is secreted into the midgut. These findings confirm the involvement of Ornithodoros defensin in midgut immunity.
In vitro dentinal penetration by tracers used in microleakage studies
Authors: Youngson  , Glyn Jones  , Manogue  , Smith
Published: March 2003

Many microleakage studies, in their methodology, employ different tracers which may penetrate around restorative materials to varying extents due to their physical or chemical characteristics. The present series of in vitro studies were designed to compare the ability of freshly obtained microleakage tracers to enter cut dentinal tubules. Tracers selected were 5% eosin, 2% methylene blue, 50% silver nitrate and Indian ink all buffered, where necessary, to a range of pH 6.9–7.2. The solution of Indian ink was further investigated by particle size analysis to determine the range of particle sizes within the solution. Particles ranged from <1 μm to 600 μm. Buffered and unbuffered solutions of the tracers were applied for 1 h to open cavities, devoid of a smear layer, prepared in 42 premolars. Specimens were sectioned longitudinally through the cavities either with or without water coolant. Penetration into dentinal tubules by the tracer resulted in an area of stained dentine and this area was subsequently measured using image analysis. The results demonstrated that there were few statistically significant differences between the areas of dentinal penetration associated with each tracer. Neither the tracer used, its pH nor sectioning technique had a predictably significant effect on dentinal penetration. Indian ink was observed to be capable of entering dentinal tubules.
A teaching model for endodontic surgery
Authors: Sauveur  , Boucher
Published: March 2003

It is often difficult to achieve realistic simulation in teaching endodontic surgery. There is relatively little material available to students other than animal tissue or human cadavers. We propose a working model for the teaching of this discipline, constructed from casts of a natural skull which reproduce anatomical features such as gingiva, maxillary sinus, or mandibular canal, for example. This model, made of polyurethane resin containing mineral particles, which closely simulates the radiological and tactile differences of the relative densities of spongy bone, cortical bone and teeth, permits close simulation of the conditions under which endodontic surgery may be performed.
Endodontic retreatment behaviour: the influence of disease concepts and personal values
Authors: Reit  , Kvist
Published: March 2003

To explain dentists' variation in endodontic retreatment decision making a praxis concept (PC) has been generated. PC assumes that practitioners operate along a health continuum. Various periapical conditions are then perceived as different stages on a continuous health scale, based on their radiographic appearance. PC suggests that an individual's placement of a cut‐off point for retreatment on the health continuum to a large extent is dependent on the agent's personal values. In the present study value judgements (utilities) concerning two periapical health states in endodontically treated teeth were investigated among 82 dental students. The two methods used to elicit utilities, a Visual Analogue Scale (VAS) and the Standard Gamble (SG), produced large inter‐ and intra‐individual variations. VAS frequently generated lower utility values. The results obtained in the study satisfy a necessary criterion for the validity of PC and strengthen the position of the theory.
Herpes zoster of the trigeminal nerve third branch: a case report and review of the literature
Authors: Tidwell E. , Hutson B. , Burkhart N. , Gutmann J. L. , Ellis C. D.
Published: March 2003

Literature review and case report A literature review of Herpes zoster of the trigeminal nerve is presented. Included are differential diagnosis and treatment modalities that will enable the dental practitioner to identify and manage this disease. A case report is provided to amplify this timely information.
Rotary Ni‐Ti profile systems for preparing curved canals in resin blocks: influence of operator on instrument breakage
Authors: Mandel E. , Adib‐Yazdi M. , Benhamou L. ‐M. , Lachkar T. , Mesgouez C. , Sobel M.
Published: March 2003

Mandel E, Adib‐Yazdi M, Benhamou L‐M, Lachkar T, Mesgouez C, Sobel M. Rotary Ni‐Ti profile systems for preparing curved canals in resin blocks: influence of operator on instrument breakage. International Endodontic Journal,32, 436–443 1999.

Aim The aim of this study was to determine the incidence of fracture of ProFile 0.4 and 0.6 taper Series 29 nickel‐titanium instruments with respect to operator experience.

Methodology A total of 125 simulated root canals in resin blocks with the same geometrical shape in terms of angle and radius of curvature and coronal and apical orifice diameter were used. Five operators prepared all the specimens using an identical step‐down instrument sequence, each one preparing 25 canals. The operators included two endodontists and three general practitioners. Statistical data concerning the incidence of instrument failure was compiled using Statlab and Fisher’s partial least square difference analysis of variance.

Results A total of 21 (16.8%) instruments fractured, all had 0.04 tapers. Nine size 25 instruments failed, 9 xsize 20 instruments failed and 3 size 15. During the study, the Binary Tree analysis of instrument failure revealed two operator populations belonging to two different study periods. The first period, which represented the first 13 root canal preparations, was called the ‘learning period’, and the second period, which represented the next 12 sample preparations, was called the ‘application period’. A greater number of instruments failed during the first period than during the second. In the ‘learning period’, both groups of operators learned the same way. In the ‘application period’, two groups could be distinguished; the first group consisted of a general practitioner who produced worse results, and the second group consisted of the other four operators.

Conclusions The results indicate the necessity of mastering this rotary canal preparation technique, and the importance of improving competence through learning and experience.
An in vitro study into the effect of the ferrule preparation on the fracture resistance of crowned teeth incorporating prefabricated post and composite core restorations
Authors: Al‐Hazaimeh N. , Gutteridge D. L.
Published: March 2003

Aim

This in vitro study investigated the effect of a ferrule preparation on the fracture resistance of crowned central incisors incorporating a prefabricated post (Parapost) cemented with Panavia‐Ex and with a composite core.

Methodology

The test group consisted of 10 post crowned natural central incisor teeth with a 2‐mm wide ferrule preparation, whilst the control group of 10 teeth had no ferrule. The specimens were mounted on a Lloyd universal testing machine and a compressive load was applied at an angle of 135 degrees to the palatal surface of the crown until failure occurred.

Results

In both groups, failure occurred at higher loads compared with previous studies. The mean failure load was 1218 N for the unferruled group and 1407 N for the ferruled group. Statistical analysis showed no significant difference between the groups.

Conclusions

Under the conditions of this study, when composite cement and core materials are utilized with a Parapost prefabricated system invitro the additional use of a ferrule preparation has no benefit in terms of resistance to fracture.
Effects of endodontic instrument handle diameter on electromyographic activity of forearm and hand muscles
Authors: Ozawa T. , Nakano M. , Sugimura H. , Kurayama H. , Tahata K. , Nakamura J. , Shiozawa K.
Published: March 2003

Aim

To determine the influence of the handle diameter of endodontic instruments on forearm and hand muscle activity using electromyographic (EMG) recording.

Methodology

Size 45 K‐type files were fitted with four different handle diameters; 3.5, 4.0, 5.0, and 6.0 mm. Seven dentists then attempted to negotiate to the working length acrylic resin root canals with each of the four handle sizes using a reaming motion. EMG activities were recorded from the flexor pollicis brevis muscle (f.p.b.), the flexor carpi radialis muscle (f.c.r.), and the brachioradialis muscle (b) with bipolar surface electrodes. The time taken to negotiate the canals, the area of integrated EMG that corresponded to the amount of EMG activity required during penetration and the maximum amplitude of EMG were measured using the EMG data. Results were analysed statistically using a one‐way factorial anova test and multiple comparison tests.

Results

Reaming time and integrated EMG area of each muscle decreased with an increase in handle diameter. The most significant difference in time and area of integrated EMG was detected between handles of 6 mm and 3.5 mm diameter (time: P < 0.01, area of the f.p.b.: P < 0.01, area of the f.c.r. and b: P < 0.05), and between handles of 5 mm and 3.5 mm diameter (P < 0.05). Both 5 mm and 6 mm handles significantly decreased the maximum amplitude of EMG recorded from the f.p.b. compared with 3.5 mm handles (between 3.5 mm and 6 mm: P < 0.01, between 3.5 mm and 5 mm: P < 0.05).

Conclusion

The results indicate that handle diameter has an effect on reaming time as well as on muscle activity. As a consequence, handle diameter influenced operator performance during instrumentation.
The standardized‐taper root canal preparation – Part 5. GT file technique in Small Root canals
Authors: Buchanan L. S.
Published: March 2003

Aim To describe the shaping of Small Root canals with GT files.

Summary Small Roots are lower incisors, two and three canal bicuspids, buccal roots of upper molars, and mesial roots of lower molars. The Shaping Objective instrument for such cases is usually a 0.08 or 0.06 taper GT file. After proper access, pulp tissue should be removed to prevent its compaction and canal blockage. Orifice shaping and smoothing is then achieved with a 35‐0.12 accessory GT File, running at full slow‐speed r.p.m. (5–20K).

Crown‐down preparation commences with the 0.10 GT file, followed by the 0.08 and 0.06 tapers as needed. Occasionally, a 20‐0.04 Profile is required to reach length. Files are rotated at 300 r.p.m. with steady, light pressure, and withdrawn frequently for cleaning and inspection. Once one of these files has cut to length, the canal terminus is enlarged to Shaping Objective. If difficulty is encountered, be willing to accept a 0.06 instead of the original 0.08 taper Shaping Objective. If the terminal diameter is 0.2 mm you will have plenty of apical resistance form in a tortuous canal with the 0.06 taper preparation. It is definitely better to end up with a smaller shape than originally planned, than to experience the heartache of separation.

Key learning points

 Small Root canals should be prepared to a Shaping Objective 0.08 or 0.06 taper.

 Pulp tissue should be removed before preparation to prevent compaction and blockage.

 Preparation follows in a crown‐down sequence, and may occasionally require the use of small Profiles.

 Final apical shaping is easily achieved when root length is reached.
Coronal leakage following three obturation techniques
Authors: Gilbert S. D. , Witherspoon D. E. , Berry C. W.
Published: March 2003

Aim

To compare coronal bacterial and India ink leakage in three different obturation techniques with the smear layer having been removed.

Methodology

Seventy extracted single‐rooted teeth were instrumented to an apical preparation size 7 Profile Series 29 (Tulsa Dental Products, Tulsa, OK, USA). The smear layer was removed and 20 teeth were randomly obturated with lateral compaction, 20 teeth with vertical compaction, and 20 teeth with Thermafil (Tulsa Dental Products, Tulsa OK, USA). Ten teeth were used for positive (five teeth) and negative (five teeth) controls. Teeth were stored for 90 days in 100% humidity, then subjected coronally to Proteus vulgaris for 21 days to assess bacterial leakage. Following bacterial challenge, India ink was placed coronally for a further 21 days, then scored according to depth of dye leakage.

Results

Vertical compaction leaked significantly less than lateral compaction during bacterial challenge. However, when dye was used there were no significant differences.

Conclusions

Bacterial leakage and dye leakage demonstrated considerable variability. The use of a dye following bacterial testing may highlight the failure of experimental devices and vertical root fractures, thus avoiding false positive results found with bacterial testing alone.
Effect of calcium hydroxide form and placement on root dentine pH
Authors: Pérez F. , Franchi M. , Péli J. F.
Published: March 2003

Aim

The aim of this study was to measure variations in dentinal pH following the placement of various forms of calcium hydroxide in either the root canal or the pulp chamber.

Methodology

Extracted single‐rooted human teeth were prepared, and the root canals instrumented using a conventional technique. Three cavities were drilled through the root dentine to within 1 mm of the canal wall at the cervical, middle and apical thirds. A total of 125 teeth were randomly divided into five groups; group 1: pure aqueous calcium hydroxide paste (calcium hydroxide/distilled water solution) was placed in the root canal; group 2: the same aqueous calcium hydroxide paste was placed in the pulp chamber; group 3: Hycal®, a new form of calcium hydroxide paste, was placed in the pulp chamber; group 4: calcium hydroxide gutta‐percha points were placed in the root canal; group 5: control group, wet canal (distilled water) without medication. The access cavities and apical ends were sealed, and the teeth were placed in individual vials containing phosphate‐buffered saline, and stored at 37 °C. The pH was measured in the dentinal cavities at 8 h and at 1, 2, 3, 7, 14, and 21 days using a calibrated microelectrode.

Results

At 8 h and 1, 2, and 3 days, the highest pH values were obtained when the aqueous calcium hydroxide paste was placed in the pulp chamber. At 7 days, the pH had increased in the Hycal® group without being significantly different from the aqueous calcium hydroxide paste placed either in the root canal or in the pulp chamber. At 14 days, Hycal® had the highest pH values (pH 10.65); however, at 21 days no significant difference was noted amongst these first three groups. Control group values ranged from 7.88 to 8.60; the pH created by the calcium hydroxide gutta‐percha points was lower than for the control group. Whatever the product or placement location, cervical pH was similar to middle pH, and greater than apical. However, there was no significant difference between the three when all groups were combined. Overall, aqueous calcium hydroxide paste placed in the pulp chamber provided the highest pH values during the experiment, except at day 14. The aqueous calcium hydroxide paste placed in the root canal or Hycal® had similar values at days 7 and 21.

Conclusions

Under the conditions of this study, an aqueous calcium hydroxide paste placed in the pulp chamber increased dentinal pH more than the other techniques. The pH of dentine is affected by the form of calcium hydroxide used.
Effect of conditioning films and a novel anti‐adherent agent on bacterial adherence to dentine
Authors: Maglad A. , Spratt D. A. , Ng Y‐L. , Gulabivala K.
Published: March 2003

Aim Adherence of bacteria to dentine is a prerequisite to infection of the root canal system, yet adherence of root canal bacteria to dentine is poorly understood. The aim of this study was to evaluate the effect of conditioning films and anti‐adherent compounds on bacterial adherence to dentine.

Methodology Freshly extracted molar teeth were prepared and sectioned to give 225 discs of predetermined dimensions. The discs were allocated to two groups. Group 1 (n = 189) was divided into three subgroups (n = 63) and coated with one of three conditioning agents (artificial saliva, serum, or distilled water) prior to bacterial inoculation. Group 2 discs (n = 36) were treated with either a novel anti‐adherent agent (PC1036, Biocompatibles) (n = 18) or distilled water (n = 18) prior to conditioning with artificial saliva. Monospecies bacterial biofilms were generated on the dentine discs by incubating them in brain heart infusion broth (37 gL−1) containing Streptococcus intermedius (Si), Enterococcus faecalis (Ef) or Lactobacillus fermentum (Lf) (originally isolated from infected root canals). The number of bacteria adhering to the discs in each of the groups was determined using standard serial dilution protocols. Additional discs were prepared under all conditions for scanning electron microscopy. Where appropriate, statistical analysis by one way anova, post hoc Bonferroni, and independent t‐test were used.

Results Si adhered significantly better to dentine when conditioned with serum compared with artificial saliva (P = 0.005) or distilled water (P = 0.009). Conversely, Ef adhered significantly better to the control discs (distilled water) compared with serum conditioned discs (P = 0.016). The conditioning films had no effect on the adherence of Lf, which adhered to the dentine discs significantly less (P = 0.001) than either Si or Ef. The anti‐adherent coating significantly reduced the number of Si adhering to the dentine compared with the control (P = 0.012).

Conclusion Given the importance of adherence in root canal infection it is conceivable that an anti‐adherent compound, could be used to prevent bacterial recontamination of cavities or the root canal system.
Occlusal loading of EBA and MTA root‐end fillings in a computer‐controlled masticator: a scanning electron microscopic study
Authors: Peters C. I. , Peters O. A.
Published: March 2003

Aim The aim of this investigation was to assess the marginal adaptation of Super‐EBA (EBA) and Pro Root MTA (MTA) root‐end fillings and the occurrence of microcracks in resected root‐ends of extracted teeth before and after occlusal loading for a five‐year equivalent period in a computer‐controlled masticator.

Methodology Twenty‐four molar teeth were root‐filled using lateral condensation and their root‐ends resected. Root‐end cavities were prepared and either EBA or MTA root‐end fillings were placed. All surgical procedures were completed in vitro under an operating microscope. Replicas taken of the root‐end fillings and resected root‐ends were examined using an SEM before and after they were subjected to in vitro chewing cycles in a computer‐controlled chewing simulator for the equivalent of 5 years. Marginal adaptation and integrity of the two root‐end filling materials were evaluated and the presence of microcracks recorded.

Results Before loading, a continuous margin was observed with 99.4 ± 2.4% of EBA and 99.2 ± 1.6% of MTA root‐end fillings. After loading, the percentage of continuous margin decreased to 93.1 ± 6.6% and 98.9 ± 3.2% for EBA and MTA, respectively. After occlusal loading, 39.5% of the EBA root‐end fillings were overfilled, whilst 52.6% of the MTA root‐end fillings were underfilled. In total, 12.5% of the resected root‐end surfaces showed microcracking before loading and 25% after occlusal loading.

Conclusions Both EBA and MTA displayed excellent marginal adaptation before masticatory loading. After loading, the amount of continuous margin for both root‐end filling materials decreased slightly but was still high.
Non‐surgical root canal treatment of dens invaginatus type 2 in a maxillary lateral incisor
Authors: Tsurumachi T. , Hayashi M. , Takeichi O.
Published: March 2003

Aim  To describe the clinical management of an unusual dens invaginatus type 2.

Summary  A case of dens invaginatus in a maxillary lateral incisor with a periapical lesion is reported. The patient presented with pain and localized swelling. Despite the complex anatomy and diagnosis of dens invaginatus, non‐surgical root canal treatment was performed successfully.

Key learning points

 Dens invaginatus may be presented in many forms, and the aetiology of this phenomenon is not fully understood.

 Due to abnormal anatomical configuration, dens invaginatus presents technical difficulties in its clinical management.

 Non‐surgical root canal treatment can be performed successfully.
Vitality status of microorganisms in infected human root dentine
Authors: Weiger R. , De Lucena J. , Decker H. E. , Löst C.
Published: March 2003

Aim This experimental study was initiated to establish a method for characterizing the vitality status of bacteria in infected human root dentine by differentiating between viable and dead microorganisms.

Methodology Twenty‐four root segments of extracted human teeth were infected with either Streptococcus sanguinis or Enterococcus faecalis for 8 weeks. Baseline samples from root dentine (rd) were collected after 4 weeks. These were compared with samples taken at week 8 (control group: n = 12) and with samples collected at week 12 after calcium hydroxide treatment for four weeks (test group: n = 12). After marking viable and dead bacterial cells by two fluorescent dyes, the portion of viable bacteria (PVB) was determined, as well as the number of colony‐forming units (CFU).

Results Viable and dead bacteria were identified in all ‘rd’ samples. PVBrd values were lower than PVB values of the bacterial suspension in the root canal lumen. In the control group, PVBrd and CFUrd did not markedly differ at week 4 and at week 8, regardless of the strain used. In the test group, viable but non‐culturable sanguinis streptococci (mean PVBrd = 27%; CFUrd = 0) were detected, despite calcium hydroxide treatment. The viability of E. faecalis was not affected by calcium hydroxide.

Conclusions Fluorescence labelling of bacteria in human root dentine gives valuable additional information about their vitality status compared to the parameter CFU. The method may be suitable for following the fate of bacteria in dentinal tubules, for example in the presence of intracanal dressings.
Endocrine and reproductive health status of men who had experienced short‐term radiation exposure at Chernobyl
Authors: GONCHAROV  , KATSIYA  , KOLESNIKOVA  , DOBRACHEVA  , TODUA  , VAX  , GIWERCMAN  , WAITES
Published: March 2003

Hormonal and semen parameters in 416 men aged 25–45 years were examined: 328 were men who cleaned the territory around the Chernobyl nuclear reactor (called `liquidators') and 88 were healthy age‐matched controls. The dose of radiation received by the liquidators was 0.16 ± 0.08 Gy. LH, FSH, prolactin, testosterone and cortisol levels were assayed using WHO‐matched reagents. Semen analyses were performed according to the WHO Manual (1992). The mean concentration of all hormones in liquidators and controls were within the WHO‐defined normal range. The mean levels of LH and cortisol in liquidators were significantly lower ( p = 0.013 and p < 0.001, respectively) and testosterone significantly higher ( p = 0.023) than in controls. The variations in hormone levels in liquidators were not correlated with the acquired doses of radiation as measured by personal dosimeters (film badges). Semen parameters in a sub‐group of 70 liquidators were within the normal WHO‐defined range. The percentage of normal forms of spermatozoa in liquidators (35.0 ± 13.1%) was significantly lower ( p < 0.015) than in a control group (42.8 ± 8.9%). The study has shown that exposure of men to relatively short‐term radiation did not cause long‐lasting disruption of their endocrine status and spermatogenesis. The study was 7–9 years retrospective and it is therefore impossible to infer what the immediate effects of the radiation exposure were on these parameters.
Pituitary‐dependent expression of the testicular angiotensin II receptor and its subtypes in rats
Authors: HIRAI  , SONG  , KANEHARA  , SHIOTA  , UEDA  , KIM  , MIYAZAKI  , KATSUOKA  , MIYAZAKI
Published: March 2003

Angiotensin II (AT2) has been implicated in the growth and/or differentiation of its target tissues. In the present study, testicular AT2receptor and its subtypes in hypophysectomized rats were examined using quantitative in vitro autoradiography and Northern blot analysis in an attempt to determine possible involvement of pituitary hormones in their expression. Prepubescent (3 weeks of age) male Sprague–Dawley rats underwent hypophysectomy or sham operation. From 10 days thereafter, they were treated with vehicle, growth hormone, human chorionic gonadotrophin or human menopausal gonadotrophin for 10 days. Testicular AT2receptors were labelled with125I‐[Sar1,Ile8] AT2and differentiated into its subtypes (AT1and FAT2) according to their susceptibility to AT1(losartan, 5 μM) and AT2(CGP42112B, 1 μM) antagonists. Hypophysectomy led to a marked increase in AT2receptor concentration (sham‐operated rats: 0.7 ± 0.2 fmol/mg protein, hypophysectomized rats: 2.5 ± 0.6 fmol/mg protein, mean ± SEM,n = 11–12,p < 0.01) with predominant occurrence of AT1receptors. Both human chorionic gonadotrophin and human menopausal gonadotrophin decreased testicular AT2receptor concentration, whereas growth hormone did not affect AT2receptor expression. Northern blot analysis revealed both testicular AT1and AT2receptor mRNA expression to be significantly increased after hypophysectomy and reduced by gonadotrophin treatment. These results suggest that the expression of testicular AT2receptors is regulated by pituitary gonadotrophins and that AT2may play a role in testicular growth and/or differentiation.
The appearance of basal cells in the developing murine epididymis and their temporal expression of macrophage antigens
Authors: SEILER  , WENZEL  , WAGENFELD  , YEUNG  , NIESCHLAG  , COOPER
Published: March 2003

This work demonstrates similarities between epididymal basal cells and macrophages in the mouse. Light microscopic studies of the postnatal development of the murine epididymis showed that basal cells were not present before days 12, 14 and 16 in the cauda, caput and corpus epididymis, respectively. An increase in cell number per unit length of tubule perimeter was demonstrated in all segments between days 20 and 27, when testicular fluid and spermatozoa start entering the epididymis. In the adult, there were more basal cells per unit perimeter in the cauda than caput or corpus epididymis. Conspicuous and consistent expression by basal cells of antigens detected by antibodies against tissue‐fixed macrophages (F4/80) and mature macrophages (Mac‐1) occurred only after they became established within the epithelium. Basal cells in the cauda epididymis did not display either antigen in the adult, although they persisted in the caput region. Such developmental patterns are compatible with the hypothesis that basal cells play a role in immune defence against sperm autoantigens.
Lectin histochemistry of the human testis
Authors: ARENAS  , MADRID  , BETHENCOURT  , FRAILE  , PANIAGUA
Published: March 2003

The oligosaccharide sequences of glycoconjugates and the nature of the saccharide linkage were investigated in normal human testes by means of lectin histochemistry studies, at light and electron microscopy levels. Reaction to WGA was intense in the seminiferous epithelium and interstitium. MAA showed light reactivity in all cell types of the human seminiferous epithelium, the lamina propria and Leydig cells. UEA‐I lectin labelled the lamina propria intensely and the seminiferous epithelium and Leydig cells slightly. A slight reaction to AAA was found in the seminiferous epithelium and in Leydig cells. ConA was labelled in Sertoli cells, germ cells and Leydig cells. The reaction to GNA lectin was similar although less intense. PNA labelling was slight in Sertoli cells, spermatogonia, and Leydig cells, and more intense in spermatocytes, spermatids and peritubular cells. Reaction to DSA was intense in the seminiferous epithelium and Leydig cells. HPA labelled all cell types in the seminiferous epithelium and Leydig cells slightly, and labelled peritubular cells intensely. SBA lectin showed a strong reaction in spermatids and a slight reaction in the lamina propria. The reactions to SNA, LTA, and DBA were negative in all testicular cell types. After β‐elimination pre‐treatment, MAA, UEA‐I, AAA, PNA, DSA, HPA and SBA reactions were all negative. Endo F/PNGase digestion suppressed reactivity to ConA y GNA. Staining for WGA decreased with Endo F/PNGase digestion and also after β‐elimination. Desialization increased reactivity to PNA, SBA and HPA lectins. These results indicate that the terminal sequences of oligosaccharide side‐chains in spermatocytes and, principally, in spermatids are: fucose, mannose, Neu5Ac2,3Gal1,3GalNAc, Gal1,3GalNAc, Gal1,4GlcNAc, Neu5AcGalNAc and GalNAc (in O‐glycosylated proteins); mannose (in N‐glycosylated proteins) and GlcNAc (in both protein types). A sialic acid residue is added to galactose and GalNAc residues. Present findings also indicate that Sertoli cell glycoproteins are similar to those of spermatids, and that the terminal sugar residues in Leydig cells are GlcNAc, fucose, mannose, Neu5Ac2,3Gal1,3GalNAc, Gal1,3GalNAc, and Gal1,4GlcNAc. The lectin pattern of the lamina propria suggests the presence of GlcNAc, galactose, fucose and GalNAc.
Apoptosis and mitosis in gonocytes of the rat testis during foetal and neonatal development
Authors: Boulogne Barbara , Olaso Robert , Levacher Christine , Durand Philippe , Habert René
Published: March 2003

This study was undertaken to determine the extent of apoptosis and mitosis in the various testicular cell types throughout rat development from foetal day 14.5 to postnatal days 9–10. Apoptotic activity was studied by detecting DNA fragmentation (TUNEL method) in situ. A TUNEL‐positive reaction was detected in gonocytes, while none of the other testicular cells were labelled. The morphology of the TUNEL‐positive gonocytes was characteristic of apoptotic cells and was different from that observed in experimentally induced necrosis. The percentage of stained gonocytes peaked on day 15.5–16.5 post‐conception (dpc), decreased thereafter and no TUNEL‐positive gonocytes were found from foetal day 18.5 onwards. On postnatal day 2, apoptosis resumed and increased to reach a maximum on day 7. Mitosis in the gonocytes, as evaluated by the immunodetection of 5‐bromo‐2′‐deoxyuridine (BrdU) incorporation, was present during the same developmental periods but the ratio of BrdU‐positive/TUNEL‐positive gonocytes was much greater in the foetal period than in the neonatal period. In an organotypic culture system, the changes in the apoptotic and mitotic activities of the gonocytes in testicular explants from foetuses on days 18.5 and 20.5 or from neonates on day 3, cultured for two days were similar to those observed in vivo. Addition of LH or FSH did not influence either apoptosis or mitosis in the germ cells. These results suggest that both apoptosis and mitosis of gonocytes are independent of gonadotrophins and are mainly controlled by intratesticular factors.
Human leucocyte antigen I expression in spermatozoa from infertile men
Authors: Paradisi Roberto , Neri Simona , Pession Annalisa , Magrini Elisabetta , Bellavia Emanuela , Ceccardi Stefania , Venturoli Stefano , Flamigni Carlo
Published: March 2003

The expression of class I human leucocyte antigen (HLA) has been investigated by reverse transcription polymerase chain reaction (RT‐PCR) and flow cytometry on human purified ejaculated spermatozoa from an infertile population. Similar investigation in a control fertile population has been performed. Among 22 fertile and 20 infertile men, 17 were selected for the study because they showed no contamination with non‐sperm cells. HLA I molecules were expressed in four of nine fertile subjects (44.4%) and three of eight infertile subjects (37.5%), with no significant difference between groups. These data demonstrate for the first time the presence of class I HLA antigens on spermatozoa of infertile subjects. In addition, considering that similar results have been obtained in both fertile and infertile populations, the hypothesis that the fertilizing capacity of the spermatozoon is independent of class I HLA‐antigen expression on their surface may be advanced.
Imprinting analysis in spermatozoa prepared for intracytoplasmic sperm injection (ICSI)
Authors: Manning Martina , Lissens Willy , Liebaers Inge , Van Steirteghem André , Weidner Wolfgang
Published: March 2003

Genetic imprinting is a mechanism of gene regulation by which only one of the parental copies of a gene is expressed. This process is mediated by the methylation of DNA. As spermatozoa represent exclusively the paternal contribution to a future individual, they are expected to carry the paternal imprint only. For intracytoplasmic sperm injection (ICSI), spermatozoa mostly have to be selected from samples with pathological semen parameters. Correct establishment of the paternal imprint in these spermatozoa has not yet been demonstrated. In the present study, imprinting analysis was undertaken using DNA extracted from spermatozoa from men with normal semen analysis (group A: n=30 patients) and from men with an abnormal sperm count (B: n=30 patients with 5–20 million spermatozoa/mL and C: n=30 patients with ≤5 million spermatozoa/mL) from the ICSI program. It was performed using firstly a conventional methylation‐specific polymerase‐chain‐reaction (M‐PCR) and secondly a more sensitive modified hemi‐nested M‐PCR technique. In addition, a single cell PCR was performed on a total of 88 single spermatozoa (collected from nine males) and on 25 leucocytes (control group). With the conventional M‐PCR, exclusively paternal imprints were found in all groups. Using the more sensitive hemi‐nested M‐PCR, additional maternal imprints were found in 63% of the samples in A, 57% in B and 60% in C. In the single cell PCR, exclusively paternal imprints were detected. Because of the very small amount of DNA (3 pg), a complete amplification failure occurred in 43% of spermatozoa. The correct paternal and maternal imprints were found in 56% of the analysed leucocytes (complete amplification failure in the other 44%). In conclusion, ejaculated spermatozoa from males with medium or high‐grade semen pathology proved to have the same imprinting status as those from males with normal semen parameters. As the additional maternal imprints were never found at the single cell level, they were classified as contamination by diploid cells such as leucocytes or immature germ cells in the processed and purified semen samples, which can be detected by a more sensitive PCR method in contrast to the conventional standard PCR.
A comparison of megestrol acetate, nandrolone decanoate and dietary counselling for HIV associated weight loss
Authors: Batterham Marijka Jane , Garsia Roger
Published: March 2003

This randomized, prospective study compared three treatments, nandrolone decanoate (ND), megestrol acetate (MA) or dietary counselling, for managing human immunodeficiency syndrome (HIV) associated weight loss. It was centred on a Tertiary referral hospital, Sydney, Australia. Fifteen patients were randomized to receive ND (100 mg/fortnight), or MA (400 mg/day) or dietary counselling for 12 weeks. Those patients randomized to dietary counselling were further randomized to receive nandrolone or megestrol after completing the dietary counselling arm. Weight, fat free mass (FFM), percentage body fat mass (FM), dietary intake and appetite were assessed before commencing and at the completion of each treatment arm. Weight increased significantly in all treatment arms (dietary counselling 1.13 kg ± 0.36, nandrolone 4.01 kg ± 1.68, megestrol 10.20 kg ± 4.51, p < 0.05 paired t‐test). FFM increased significantly in patients receiving ND (3.54 ± 1.98 kg, p=0.001) and those receiving MA (2.76 ± 0.55 kg, p=0.002), whereas the change in those receiving dietary counselling alone was not significant. Percentage body fat mass increased significantly only in those receiving MA (7.77 ± 4.85%, p=0.049). The change in weight and percentage body fat mass was significantly greater in those receiving MA than the other two treatment arms. The increase in FFM was significantly greater in both the nandrolone and megestrol arms than the dietary counselling arm. It was concluded that ND and MA both resulted in an increase in FFM greater than dietary counselling alone. Megestrol produced a significantly greater increase in weight, percentage fat mass, intake and appetite than did the other two treatment arms, suggesting it may be the preferred agent, particularly in a palliative care setting in which weight, appetite and intake increase are desirable without regard to the composition of the body. The long‐term use of these agents in people with HIV should be reviewed in the context of improved survival on highly active antiretroviral therapy regimens.
Novel amino acid substitutional mutation, tyrosine‐739‐aspartic acid, in the androgen receptor gene in complete androgen insensitivity syndrome
Authors: Suzuki Kazuhiro , Fukabori Yoshitatsu , Nakazato Haruki , Hasumi Masaru , Matsui Hiroshi , Ito Kazuto , Kurokawa Kohei , Yamanaka Hidetoshi
Published: March 2003

Androgen insensitivity syndrome (AIS) is an X‐linked recessive disorder. The molecular mechanism of AIS is reduction or absence of androgen signalling caused by androgen receptor (AR) malfunction or absence. The phenotype of AIS varies from a complete female phenotype (complete AIS, CAIS) to male genitalia with mild hypospadias (partial AIS, PAIS). In the current study, we characterize a novel point mutation in the ligand binding domain of the AR gene in a 50‐year‐old Japanese CAIS patient. Sequence analysis showed a single point mutation at nucleotide 3359 (Genbank, NM 000044), T to C, in exon E in the AR gene. This mutation led to the conversion of codon 739 tyrosine into aspartic acid in the ligand binding domain. No specific androgen binding was detected in genital fibroblasts isolated from the patient. Transcriptional activating activity of the mutant AR was examined by transient DNA transfection into COS‐1 cells. Wild‐type AR successfully activated androgen inducible MMTV promoter dose‐dependently. In contrast, the mutant AR did not activate MMTV promoter. Thus, we demonstrated the molecular characteristics of the novel point mutation in the ligand binding domain of the AR gene associated with CAIS. This information will provide a further understanding of the structure and function of the AR gene.