bluuebunny/crossref_metadata_2025 huggingface dataset:
Modulation in vitro of human natural cytotoxicity, lymphocyte proliferative response to mitogens and cytokine production by essential fatty acids
Authors: PURASIRI P. , MCKECHNIE A. , HEYS S. D. , EREMIN O.
Published: November 2003

Essential fatty acids (EFA) have been shown in animal studies to have a differential effect on various aspects of immune reactivity. However, there have been few studies in humans. Therefore, we elected to investigate the effects of a variety of EFA [ gamma‐linolenic acid (GLA), eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA)] in vitro on human blood lymphocyte reactivity, cytokine secretion and natural cytotoxicity. The proliferative response to polyclonal mitogens (phytohaemagglutinin, pokeweed mitogen, concanavalin A), as measured by [3H]thymidine incorporation into newly synthesized lymphocytes, was inhibited (P<0·05) by all EFAs tested, in a dose‐dependent manner (3–15 &mgr;g/ml). The greatest inhibition of proliferation was caused by EPA and DHA. Similarly, EPA, DHA and GLA significantly reduced cytotoxic activity [expressed as lytic units, using 51 chromium‐release assays, natural killer (NK) (K562 cells) and lymphokine‐activated (LAK) (Daudi cells) cells] (P<0·05) in a concentration‐dependent manner (5–50 &mgr;g/ml), without affecting cell viability. EPA and DHA exhibited greater suppression than GLA. Furthermore, the inhibition of cell proliferation and suppression of natural cytotoxicity was associated with marked decrease in cytokine [interleukin‐1 (IL‐1), IL‐2, tumour necrosis factor‐&agr; (TNF‐&agr;) and interferon‐&ggr; (IFN‐&ggr;)] production in vitro. Our findings demonstrate that EFAs (GLA, EPA, DHA) have the potential to inhibit significantly various aspects of human lymphocyte cell‐mediated and humoral immune reactivities.
The effects of monoclonal antibodies against iC3b receptors in mice with experimentally induced disseminated candidiasis
Authors: LEE K. H. , YOON M. S. , CHUN W. H.
Published: November 2003

CR3 (iC3b receptor), composed of CD11b/CD18, is a β2 integrin. A protein that shares antigenic and structural homology with the α‐chain of CD11b/CD18 has been isolated from the surface of Candidaalbicans. This molecule is thought to be essential in the pathogenesis of disseminated candidiasis. To evaluate the effects of anti‐iC3b receptor antibodies on adhesion between human dermal microvascular endothelial cells (HDMEC) and C.albicans,and in treatment of candidal infection, a binding assay of C. albicans to cultured HDMEC was performed in vitro. An anti‐iC3b receptor‐specific monoclonal antibody was administered to mice infected with C. albicans. The mice were monitored for mortality and renal involvement by culture and histopathological findings. Flow cytometric analysis demonstrated surface expression of iC3b receptor on C. albicans. The adherence of C. albicans to HDMEC was significantly decreased by treatment with anti‐iC3b receptor antibodies. Anti‐iC3b receptor antibodies significantly increased the survival time and rate while lowering the renal fungal burden. The iC3b receptors are involved in the adherence of C. albicans to vascular endothelial cells and are likely to be involved in the pathogenesis of disseminated candidiasis. The increased survival in mice infected with C. albicans after treatment with anti‐iC3b receptor antibodies indicates that this modality may be beneficial for future development of a new therapy for candidiasis.
Meta‐CASE: Is the game worth the candle?
Authors: Ter Hofstede A. H. M. , Verhoef T. F.
Published: November 2003

The current generation of CASE (Computer Aided Software Engineering) tools is too inflexible to provide adequate modelling support. One of the proposed solutions to this problem is the development of so‐called CASE shells. A CASE shell is a method independent CASE tool, which may be instantiated with a specific method to become a CASE tool supporting that method. As such, a CASE shell provides complete flexibility. This paper does not address the benefits of CASE shells, as they are completely clear, but focuses on the feasibility of this concept from a theoretical as well as a practical point of view.
Ethical theory, codes of ethics and IS practice
Authors: Walsham Geoff
Published: November 2003

Ethical issues, with respect to computer‐based information systems, are important to the individual IS practitioner. These same issues also have an important impact on the moral well‐being of organizations and societies. Considerable discussion has taken place in the Information Systems (IS) literature on specific ethical issues, but there is little published work which relates these issues to mainstream ethical theory. This paper describes a range of ethical theories drawn from philosophy literature and uses these theories to critique aspects of the newly revised ACM Code of Ethics. Some in the IS field on problematic ethical issues which are not resolved by the Code are then identified and discussed. The paper draws some implications and conclusions on the value of ethical theory and codes of practice, and on further work to develop existing ethical themes and to promote new initiatives in the ethical domain.
Information systems sourcing: examining the privatization option in USA public administration
Authors: Lacity Mary C. , Willcocks Leslie
Published: November 2003

The process and content of decision‐making on sourcing information systems (IS) is assessed. Two case histories from the USA public sector are examined in detail. We find that outsourcing IS problems, as opposed to tasks, rarely works in either private or public sectors. The findings suggest that both sectors must develop similar IS competencies before considering sourcing decisions. These include fostering relationships with senior management, bench‐marking performance, creating shared IS objectives, understanding requirements, diagnosing IS problems, evaluating in‐house versus market capabilities and, in the case of outsourcing, developing competencies in contract negotiation and post‐contract management. The major difference between public and private sector sourcing was found to be that public sector agencies faced more environmental constraints, including dictated budgets and requirements, and restrictions on civil servant salaries.
Trying to adopt systems development methodologies — a case‐based exploration of business users' interests
Authors: Sauer Chris , Lau Colleen
Published: November 2003

Information systems methodologies are an important component of the IS infrastructure and a primary device for organizing systems development work. Evidence suggests that methodology adoption and use are problematic. This research seeks to generate insight into business users' interest in adoption through detailed examination of a case. A framework is developed for organizing relevant research findings. The field research methods are described and details of the case reported. The case highlights the role of business managers in methodology adoption and the influence of business pressures originating in the strategic environment. Analysis shows the organizing framework to require extension to include a more direct role for business decision makers. it is argued that previous research has obscured the legitimate concern of business with systems development methodologies. As business increasingly asserts its interest in and control over IS, it will be necessary to give greater consideration to the needs of business in the selection and adoption of methodologies.
Colruyt: an organization committed to communication
Authors: Janson M. , Brown A. , Taillieu T.
Published: November 2003

The perception that organizations are developing very different organizational structures from those identified by Mintzberg (1979) has been steadily gaining ground. For example, the Colruyt Company has been developing a new organizational form since its start‐up in 1965, which was distinctly different from any of the five basic forms identified by Mintzberg (1970) a decade later. This article shows how the Colruyt Company differs from its counterparts in terms of corporate core beliefs and values, employee involvement, managerial strategy and the application of information technology. The outcome of our research will be of value to other companies that desire to pursue innovative approaches similar to those followed by the Colruyt Company.
User viewpoint modelling: understanding and representing user viewpoints during requirements definition
Authors: Darke P. , Shanks G.
Published: November 2003

There has been increasing awareness of the impact of the early stages of systems development on the quality of information systems. A critical early activity is requirements definition, when the requirements for an information system are determined. Traditional requirements capture techniques do not support the collaborative nature of requirements definition or the emergent nature of requirements themselves. This paper focuses on viewpoint development as a means of resolving some of the difficulties of requirements definition. It proposes a user viewpoint model for capturing and representing the viewpoints of users during requirements acquisition. The model can facilitate communication and interaction between analysts and users and help build a shared understanding of requirements. It can be used to structure the requirements acquisition process. The model provides for evaluation of requirements acquisition techniques to guide the selection of appropriate techniques for developing user viewpoint models. The paper reports a multiple‐case study of requirements definition efforts that examined user viewpoint development in practice and used the cases to validate empirically the concepts of the user viewpoint model. The implications of the case study findings for requirements definition practice are discussed, and some areas for future research are identified.
Improving management information systems research: question order effects in surveys
Authors: Drury D. H. , Farhoomand A.
Published: November 2003

This paper demonstrates the impact that question order can have in using survey research in management information systems (MIS). Using data from a survey of 379 companies concerning electronic data interchange (EDI), significant differences are found in the evaluation of successful implementations. The overall evaluation of success is increased (or decreased) depending upon alternative versions of question order. In addition, the analyses show that the main effects from question order interact in different ways with respondent characteristics, including functional area, educational background and being a systems user. The bias tends to be consistent for some types of respondents, such as systems users. However, other classes of respondents, especially persons with professional backgrounds in systems or MIS, are influenced in more complex ways by question order. The order in which queries regarding systems output and quality occur tends to be especially important in anchoring subsequent responses and overall assessments. The final section addresses corrective actions and future research.
Mosquito hexamerins: characterization during larval development
Authors: Korochkina S. E. , Gordadze A. V. , York J. L. , Beneš H.
Published: November 2003

We report here the first examination of hexamerins expressed during mosquito larval development. Haemolymph proteins from fourth‐instar larvae of six species representing the two major subfamilies of mosquitoes were characterized by immunoblotting using antisera to calliphorin, the major hexamerin of the blowfly,

Calliphora vicina

, or to LSP1 or LSP2, the two distinct hexamerins of

Drosophila melanogaster

. In each mosquito species the antisera demonstrated the presence of multiple abundant hexamerin polypeptides of 66–85 kDa in molecular weight. According to the subunit composition of native proteins, the larval hexamerins from both

Aedes aegypti

and

Anopheles gambiae

form heterohexamers. Furthermore, the two major

Aedes

hexamerin subunits (AaHex1 and AaHex2) are neither rich in aromatic amino acids nor methionine. cDNA clones encoding AaHex1 and AaHex2 were isolated and used to show that hexamerin mRNA is uniquely expressed in fourth‐instar larvae of both

A. aegypti

and

A. gambiae

and disappears rapidly at the onset of pupal development.
Analysis of eriophyid mite rDNA internal transcribed spacer sequences reveals variable simple sequence repeats
Authors: Fenton B. , Malloch G. , Moxey E.
Published: November 2003

Ribosomal DNA internal transcribed spacers of the eriophyid mites

Cecidophyopsis ribis

,

C. selachodon

,

C. spicata

,

C. alpina

,

C. aurea

,

C. grossulariae

and

Phylocoptes gracillis

were amplified using PCR, cloned and sequenced. Sequences for the ITS1 of

Cecidophyopsids

were 92–99% homologous.

Cecidophyopsis

inter‐specific differences were found in seventeen simple sequence repeats (vSSRs), fourteen point mutations and two indels. No intra‐specific variation in vSSRs was detected. A hypothetical structure for ITS1 was obtained and vSSRs were mapped onto this. Changes in vSSRs were compensated for by changes in complementary vSSRs or through multiple point mutations. A comparison with vSSRs of other arthropods suggested that the levels of intra‐specific variation in

Cecidophyopsis

mites was less than in organisms which do not use arrhentoky for male determination.
Cloning and characterization of cDNAs preferentially expressed in the ovary of the mosquito,Anopheles gambiae
Authors: Zurita M. , Reynaud E. , Kafatos F. C.
Published: November 2003

We used differential screening to isolate from an ovarian cDNA library two expressed sequences that are enriched substantially in ovaries of blood‐fed female

Anopheles gambiae

, as compared to female carcass and male mosquitoes. One of these clones encodes an isoform of histone H2B, whose transcript is polyadenylated at the 3′ end. The other cDNA clone encodes a protein that is highly conserved in evolution and has been implicated in growth control although its function is still obscure. Both genes can be used to study gene activation during

An. gambiae

oogenesis.
In vitrocultivation ofWolbachia pipientisin anAedes albopictuscell line
Authors: O'Neill S. L. , M. Pettigrew M. , Sinkins S. P. , Braig H. R. , Andreadis T. G. , Tesh R. B.
Published: November 2003

A continuous cell line, Aa23, was established from eggs of a strain of the Asian tiger mosquito,

Aedes albopictus

, naturally infected with the intracellular symbiont

Wolbachia pipientis

. The resulting cell line was shown to be persistently infected with the bacterial endosymbiont. Treatment with antibiotics cured the cells of the infection. In the course of establishing this cell line it was noticed that RFLPs in the PCR products of two

Wolbachia

genes from the parental mosquitoes were fixed in the infected cell line. This indicates that the mosquito host was naturally superinfected with different

Wolbachia

strains, whereas the infected cell line derived from these mosquitoes only contained one of the original

Wolbachia

strains. The development of an

in vitro

culture system for this fastidious microorganism should facilitate molecular analysis of the reproduction distorting phenotypes it induces in natural arthropod hosts.
Phylogenetic characterization of two transovarially transmitted endosymbionts of the bedbug Cimex lectularius (Heteroptera: Cimicidae)
Authors: Hypša V. , Aksoy S.
Published: November 2003

Two different inherited bacterial symbionts from ovary tissue of the bedbug Cimex lectularius were characterized by gene amplification and sequencing analysis of their 16S rDNA gene. The first bacterium belongs to the Wolbachia subgroup of the alpha‐Proteobacteria, the second is a member of the gamma‐subdivision, and is closely related to the bacterial parasite of the leafhopper Euscelidius variegatus (BEV) which was shown to be capable of transovarial transmission. The high similarity (>97%) between the C. lectularius symbiont and BEV indicates that these two microorganisms belong to the same lineage and share the ability to invade distant insect hosts to fulfill their symbiotic functions and to establish transovarial transmission to future generations.
Ccmar1, a full‐length mariner element from the Mediterranean fruit fly, Ceratitis capitata
Authors: Gomulski L. M. , Torti C. , Malacrida A. R. , Gasperi G.
Published: November 2003

Using a PCR primer specific to the ITR sequence of a deleted mariner element we amplified a fragment of ∼1300 bp from the genome of Ceratitis capitata. Analysis of four clones showed that they differed by ∼4.6% in nucleotide sequence and exhibited high homology to mariner elements of the mellifera subfamily. One clone in particular, Ccmar1.18, was found to possess an ORF of 338 amino acids together with many of the features typical of mariner elements. The consensus sequence, Ccmar1, derived from these clones is presented. Maximum parsimony phylogenetic analysis of the Ccmar1 element confirms its position at the periphery of the mariner mellifera subfamily. The Ccmar1 element is estimated to be present in about 500 copies in the genome. The evolutionary history of the element in relation to the colonization history of the medfly is discussed.
Cloning and sequence of a gene for the homologue of the stearoyl CoA desaturase from salivary glands of the tick Amblyomma americanum
Authors: Luo C. , McSwain J. L. , Tucker J. S. , Sauer J. R. , Essenberg R. C.
Published: November 2003

A 1488 base pair cDNA clone has been isolated from a cDNA library made from salivary glands from 3‐day feeding adult female ticks. The sequence of this cDNA suggests it is the gene for the tick homologue of the stearoyl CoA desaturase. This gene is expressed in eggs and all feeding stages of the adult examined, but appears to be transcribed to an 8 kb mRNA as well as a 1.5 kb mRNA. Because ticks have the ability to synthesize monounsaturated fatty acids and demonstrate a large increase in salivary monounsaturated fatty acids during tick feeding, we hypothesize that stearoyl CoA desaturase may be a key enzyme in the morphogenesis of tick salivary glands during feeding.
Genetic differentiation between and within strains of the saw‐toothed grain beetle, Oryzaephilus surinamensis (Coleoptera: Silvanidae) at RAPD loci
Authors: Brown R. J. , Malcolm C. A. , Mason P. L. , Nichols R. A.
Published: November 2003

Nine strains of Oryzaephilus surinamensis have been kept in laboratory culture for periods ranging from 5 to 30 years (30–180 generations). Two RAPD primers provided sufficient information to separate the strains reliably and unambiguously. The strains are maintained at a population size of 200 breeding adults. The marked divergence between strains is consistent with the small population size, which for the older strains, according to population genetics theory, implies that roughly half the original genetic variation should now be lost from within strains. However, there is no indication that the older strains have less inter‐strain variation. The results demonstrate RAPD loci can reliably detect population subdivision, which in field populations of pest species is of fundamental importance in understanding the population genetics of insecticide resistance.
Cloning and characterization of a serine protease from the human malaria vector, Anopheles gambiae
Authors: Han Y. S. , Salazar C. E. , Reese‐Stardy S. R. , Cornel A. , Gorman M. J. , Collins F. H. , Paskewitz S. M.
Published: November 2003

The nucleotide and deduced amino acid sequence of a serine protease (AgSp24D) from the human malaria vector, Anopheles gambiae, is presented. The gene product is a 271 amino acid protein that contains the conserved serine, histidine and aspartic acid residues found in serine proteases, and has the highest identity to a serine protease of unknown function from Drosophila melanogaster. In situ hybridization to the polytene chromosomes detects a single band at 24D. Northern analysis reveals only low levels of transcripts in larvae and pupae, but more abundant transcription products occur in adults. Interestingly, this analysis also shows that adult males express much higher levels of AgSp24D mRNA than females. In addition, Plasmodium‐refractory mosquitoes express higher levels of AgSp24D mRNA than susceptible mosquitoes although the biological significance of this remains to be examined. The thorax is the primary site for expression in the adults. The lack of a dramatic increase in AgSp24D mRNA levels following blood feeding suggests that this protease is not involved in digestive processes. Transcriptional induction does not follow cold shock, septic wounding, bacterial injection, laminarin injection or CM‐Sephadex bead injection.
Application of cross‐sectional imaging in the differential diagnosis of apical radiolucency
Authors: HARRIS I. R. , BROWN J. E.
Published: November 2003

A case is described in which exact localization of a cystic lesion associated with the apices of the maxillary central incisor teeth was sought to aid diagnosis and presurgical planning. The area was imaged using cross‐sectional tomographic slices in the sagittal plane produced by a Scanora® multimodal tomographic unit (Orion Corporation Soredex, Helsinki, Finland). The images demonstrated the cystic lesion arising within the incisive canal, confirming a diagnosis of naso‐palatine duct cyst. Surgery was therefore performed via a palatal approach giving direct access to the cyst. Histological examination of the enucleated cyst confirmed a naso‐palatine duct cyst.
The effect of pulpotomy using CO2 and Nd:YAG lasers on dental pulp tissue
Authors: JUKIĆ S. , ANIĆ I. , KOBA K. , NAJŽAR‐FLEGER D. , MATSUMOTO K.
Published: November 2003

The histological response of the dental pulp after laser irradiation was studied. After pulpotomy was performed in the premolar and molar teeth of dogs, the exposed pulp tissue at the root canal opening was lased using either a CO2 or Nd:YAG laser. The laser parameters were 2 W, 10 ms, 5 times per second for 1, 2 and 3 s for CO2 laser and 2W, 20 pulses per second for 1, 2 and 3 s for the Nd:YAG laser. Observations were made 30 and 45 days after treatment. The results revealed that laser irradiation caused carbonization, necrosis, infiltration of inflammation cells, oedema and haemorrhage in the pulp tissue. Under the conditions of this experiment, there was little histological evidence of repair to the treated pulp with a newly formed dentine barrier, which was in contrast to the control samples treated with a calcium hydroxide‐containing cement(Dycal).
Microleakage of Diaket and amalgam in root‐end cavities prepared using MicroMega sonic retro‐prep tips
Authors: LLOYD A. , GUTMANN J. , DUMMER P. , NEWCOMBE R.
Published: November 2003

Thein vitro sealing ability of the root‐canal sealer Diaket when used as a root‐end filling material was compared with that of amalgam using linear microleakage of Indian ink. Eight groups of 20 extracted teeth each were formed, plus 12 control teeth as follows: 1) root‐end resection of 45° bevel, root‐end cavity preparation with an 008 round bur, amalgam root‐end filling; 2) 45° bevel, bur, Diaket; 3) 45° bevel, using a sonic retro‐prep tip, amalgam; 4) 45° bevel, sonic, Diaket; 5) no bevel, bur, amalgam; 6) no bevel, bur, Diaket; 7) no bevel, sonic, amalgam; 8) no bevel, sonic, Diaket, Root‐end cavity depths of 3 mm were prepared. Specimens were immersed in Indian ink for 2 weeks. The teeth were demineralized, rendered transparent and linear dye penetration recorded. Results showed that Diaket provided a superior seal to amalgam irrespective of the root‐end preparation. The degree of bevel of the resected root‐end did not influence leakage. Sonic instrumentation resulted in a larger root‐end cavity than with burs.
Calcium hydroxide root canal sealers: evaluation of pH, calcium ion concentration and conductivity
Authors: da SILVA L. A. BEZERRA , LEONARDO M. R. , da SILVA R. S. , ASSED S. , GUIMARÃES L. F. L.
Published: November 2003

The calcium hydroxide ionization of four root canal sealers (Sealapex, CRCS, Sealer 26, and Apexit) was studied by measuring conductivity and pH and by conducting atomic absorption spectroptiotometry. Samples 6 mm in diameter and 15 mm long were prepared from these sealers. After setting and 48 h storage in a desiccator, five samples of each material were placed in 50 ml distilled water and analysed after 0,1,2,4, 6 and 24 h and 5, 15 and 30 days. The results showed that Sealapex was the root canal sealer showing the highest pH, ionic calcium and total calcium values (P<0.05) throughout the experimental period, followed by CRCS, Apexit and Sealer 26
Root canal treatment of a mandibular canine with three root canals. Case report
Authors: HOLTZMAN LIOR
Published: November 2003

The differing morphological manifestations of the root canal system have been the subject of research, and the incidence of various shapes of root canal systems has been classified. The present case describes the root canal treatment of a rare morphological pattern, namely a mandibular permanent canine with three root canals. No report of a similar case has been published previously.
Cutaneous odontogenic sinus tract to the chin: a case report
Authors: TIDWELL E. , JENKINS J.D. , ELLIS C.D. , HUTSON B. , CEDERBERG R.A.
Published: November 2003

We report a case of cutaneous odontogenic sinus tract to the chin. The patient first noticed the cutaneous condition in 1977. Inappropriate medical and dental treatment was ineffective. Correct diagnosis and treatment was completed in 1993. We offer diagnostic and treatment guidelines for the management of similar cases.
Sealing properties of a new epoxy resin‐based root‐canal sealer
Authors: ZMENER O. , SPIELBERG C. , LAMBERGHINI F. , RUCCI M.
Published: November 2003

In this study a new epoxy‐resin‐based endodontic sealer, AH Plus, was tested in vitro for apical leakage. The conventional sealer AH26, for which information is already available, was used as the control. The root canals of 72 single‐rooted teeth were prepared biome‐chanically using a stepback technique before lateral condensation of gutta‐percha with one of the two sealers. Teeth were immersed in 5% methylene blue dye for 2,4 or 10 days. The roots were split longitudinally so that the extent of dye penetration could be measured with a stereomicroscope. The mean extent at 2 days was 0.4 mm for AH26 and 1.4 mm for AH Plus. Neither material produced a complete apical seal and leakage increased with the duration of immersion in dye. The differences between observation periods as well as between materials with respect to dye penetration were statistically significant ANOVA, (P < 0.005).
An evaluation of microbial coronal leakage in the restored pulp chamber of root‐canal treated multirooted teeth
Authors: CHAILERTVANITKUL P. , SAUNDERS W. P. , SAUNDERS E. M. , MACKENZIE D.
Published: November 2003

This in vitro study investigated the effect of a resinreinforced glass ionomer lining material on the coronal leakage of a mixed obligate microbial marker in maxillary molars obturated with lateral condensation of cold gutta‐percha and Tubliseal sealer, after 2 years' storage. Forty maxillary first molars were prepared chemomechanically to a size 30–40 master apical file. The teeth were divided into an experimental group (30 teeth) and control group (10 teeth). In the experimental group, the floor of pulp chamber and the root‐canal opening of I5 teeth were covered with Vitrebond as a lining; the remaining 15 teeth received no lining. These teeth were tested for leakage using a microbiological marker consisting of anaerobic streptococci and Fusobacterium nucleatum. The teeth were checked daily for bacterial leakage for 60 days. All positive control teeth leaked within 48 h, while the negative control teeth remained uncontaminated throughout the test period. The teeth restored with Vitrebond liner showed no leakage whilst 60% of the specimens with no Vitrebond liner showed leakage after 60 days.
An in vitro study of coronal microleakage in root‐canal‐treated teeth restored by the post and core technique
Authors: FOX K. , GUTTERIDGE D. L.
Published: November 2003

The aims of this study were to compare coronal microleakage around cast and prefabricated post and cores and to examine the coronal seal achieved by temporary post crowns. Thirty extracted, single‐rooted, human teeth were prepared chemomechanically, root filled with gutta‐percha and sealer and prepared for a standard post. Three groups, each of 10 teeth, were restored with either: (i) cast post and cores cemented with zinc phosphate cement; (ii) prefabricated posts and composite cores cemented with a composite luting cement; or (iii) temporary post crowns cemented with a temporary zinc oxide–eugenol cement. The teeth were thermocycled and placed in Indian ink for 1 week, then demineralized and rendered transparent. Linear coronal dye penetration around the posts was measured and recorded. Results indicated that while cast post and cores and prefabricated posts and composite cores produced a good seal, leakage was significantly greater with temporary post crowns (P < 0.05). It is concluded that to prevent re‐infection of the root canal system, it may be preferable to restore the tooth immediately with a prefabricated post and composite system rather than place a temporary post crown and subsequently a cast post and core.
Evaluation of the effectiveness of sodium hypochlorite used with three irrigation methods in the elimination of Enterococcus faecalis from the root canal,in vitro
Authors: SIQUEIRA J.F. , MACHADO A.G. , SILVEIRA R.M. , LOPES H.P. , de UZEDA M.
Published: November 2003

The effectiveness of 4.0% sodium hypochlorite (NaOCl) used with three irrigation methods in the elimination ofEnterococcus faecalis from the root canal was tested in vitro. Root canals contaminated with E.faecalis were treated as follows: (i) irrigation with 2 mL of NaOCl solution and agitation with hand files;(ii)irrigation with 2 mL of NaOCl solution and ultrasonic agitation;(iii)irrigation with NaOCl alternated with hydrogen peroxide. Contaminated canals irrigated with sterile saline solution served as the control. Paper points used to sample bacteria from the root canals were transferred to tubes containing 5 mL of brain heart infusion (BHI) broth. Tubes were incubated and the appearance of broth turbidity was indicative of bacteria remaining in the root canal. There were no statistically significant differences between the experimental groups. However, NaOCl applied by the three methods tested, was significantly more effective than the saline solution(control group) in disinfecting the root canal.
Bacterial penetration through temporary restorative materials in root‐canal‐treated teeth in vitro
Authors: IMURA N. , OTANI S. M. , CAMPOS M. J. A. , JARDIM E. G. , ZUOLO M. L.
Published: November 2003

Seventy extracted single‐rooted mandibular premolars were used in this study to determine the length of time needed for bacteria present in natural human saliva to penetrate through three commonly used temporary restorative materials and through the entire root canal system obturated with the lateral condensation technique. Five intact teeth with no decay were used in the negative control group and five teeth with extensive decay in communication with the canal, in the positive control group. The 60 teeth used in the experimental group were divided into three groups. In Group 1, the access cavities of 20 teeth were temporarily restored with gutta percha, in Group 2 with IRM and in Group 3 with Cavit‐G. All 70 teeth were mounted individually where the crown was placed in contact with human saliva. All five teeth in the positive control group caused broth turbidity within 24 h. In contrast, broth in the negative control group remained clear throughout the entire experimental period. In the experimental group, the average time for broth contamination of access cavities closed with gutta percha, IRM and Cavit‐G was 7.85, 12.95 and 9.80 days, respectively. The Kruskal‐Wallis nonparametric test showed significant differences among the groups, while the multiple comparison test showed that the IRM group was statistically better than the gutta percha group when the average lengths of time for contamination were compared (P < 0.05).
Antibacterial activity of calcium hydroxide‐containing endodontic sealers onEnterococcus faecalis in vitro
Authors: FUSS Z. , WEISS E. I. , SHALHAV M.
Published: November 2003

Antimicrobial activity of endodontic sealers is an important factor in the prognosis of root canal treatment. The aim of this study was to analyse the antimicrobial activity of calcium hydroxide‐containing endodontic sealers, Sealapex (SA) and CRCS compared to a ZOE‐containing sealer, Roth's cement. The sealers were mixed and placed on the side wall of microtitre plate wells. A 10 μL suspension of Enterococcus faecalis was added to the surface of the sealers 1 h, 24 h, or 7 days after mixture. Bacteria were allowed to come into contact with the sealers for 1 h at 37°. Fresh media was then added and bacterial growth was measured every 30 min for 16 h. The results showed that in 1‐hour‐old mixture, CRCS and Roth's cement had a significantly better antimicrobial effect than SA. In 24‐hour‐old mixtures, ZOE‐based sealer showed a more potent antimicrobial activity than calcium hydroxide‐containing sealers, whereas SA showed a significantly better antimicrobial effect in the 7‐day‐old mixture. The antimicrobial activity of each tested sealer changes differently with the time interval between mixing and testing, suggesting different physicochemical properties and potentially diverse clinical applications.
Sperm counts in semen of farm animals 1932–1995
Authors: SETCHELL B. P.
Published: November 2003

In some countries, sperm counts in normal human semen seem to have declined over the last 50 years. If this decline is real and due to environmental factors, falls might also be seen in sperm numbers in the semen of farm animals. Sperm counts are available for bull, boar and ram from the early 1930s, obtained using techniques similar to those used for human semen. Data have been obtained from the literature between 1932 and 1995 from 137 studies involving bulls, 76 involving boars and 130 involving rams. All were normal adult animals, from which semen was collected regularly but at a frequency which would not be likely to cause a fall in sperm counts. The references were obtained systematically from Animal Breeding Abstracts, and where possible the original articles were consulted to obtain mean values for each study; where the original reference was not easily obtainable, values were taken from the abstract. The bull data showed no correlation of sperm count with year of publication (r2 = 0.000), for the boars there was a slight but non‐significant positive correlation (r2 = 0.041), and for the sheep there was a slight, but significant, rise in sperm counts with time (r2 = 0.124 for sperm counts and 0.126 for total sperm per ejaculate; not all authors gave both values). It would appear that, if the fall in human sperm counts is real, then it must be due to something which is not affecting farm animals.
Successful lowering of epididymal carnitine by administration of pivalate to rats
Authors: COOPER T. G. , WANG X.‐S. , YEUNG C.‐H. , LEWIN L. M.
Published: November 2003

This study was designed to lower the epididymal content of carnitine in male rats and to examine subsequent effects on fertility and sperm motility. As carnitine is transported from serum into the epididymal lumen a method to lower serum carnitine was sought. Administration of 20 mmol/L sodium pivalate in the drinking water for up to 5 weeks substantially lowered serum carnitine (to 20% of control levels within 1 week) and reduced epididymal carnitine content (to 25% of control levels in the proximal and 52% of control in distal regions) within 2 weeks. Carnitine in distal cauda epididymal fluid was also reduced (to 30% of control levels) but no changes were observed in the sperm carnitine content. The percentage motility and kinematic parameters of spermatozoa released from four epididymal regions and diluted into artificial medium were unaltered by the treatment, and all males retained their fertility in mating tests performed at weekly intervals. Increasing the dose of sodium pivalate administered to 60 mmol/L for 2 weeks lowered serum carnitine concentration more but did not further decrease epididymal carnitine content and altered neither sperm motility nor male fertility. The rat epididymis secretes an excessive amount of carnitine into its lumen so that substantially lowering the tissue content does not reduce sperm carnitine or affect their motility or fertilizing ability.
Does the gonadotrophic axis play a role in the pathogenesis of Sertoli‐cell‐only syndrome?
Authors: LEIFKE E. , SIMONI M. , KAMISCHKE A. , GROMOLL J. , BERGMANN M. , NIESCHLAG E.
Published: November 2003

Infertile men with Sertoli‐cell‐only syndrome (SCO) have highly elevated serum FSH immunoactivity related to the degree of histological damage. The activity that serum FSH exerts at the target site depends on its glycosylation pattern and FSH receptor (FSHR) function. Either could be impaired, leading to failure of spermatogenesis. The aim of the present investigation was to study bioactivity and the glycosylation pattern of serum FSH and the occurrence of mutations in the FSH receptor in infertile patients with SCO compared to normal men.

Blood was taken from 19 patients with bilateral testicular focal or complete SCO and eight normozoospermic controls. FSH bioactivity in serum was measured using an␣ in‐vitro FSH bioassay based on recombinant rat FSHR. The glycosylation pattern of serum FSH was determined by concanavalin A chromatography. Inhibin B was determined in serum using a recently available assay. Genomic DNA extracted from blood lymphocytes was amplified by PCR using primers specific for the FSHR and screened by single‐stranded conformation polymorphism gel electrophoresis.

Men with SCO showed significantly higher FSH in‐vitro bioactivity␣(34.9 ± 5.0␣IU/l) than controls (9.6 ± 0.8 IU/l; p < 0.01), as well as significantly elevated FSH immunoactivity (14.9 ± 1.7 IU/l) compared to controls (3.1 ± 0.5; p < 0.01). Immunoactivity of serum FSH was correlated with in‐vitro bioactivity (r = 0.9; p < 0.001) and was related to the degree of testicular damage (proportion of SCO‐tubules) (ANOVA: p < 0.001) and total testicular volume (r = −0.76; p < 0.01). An inverse relationship between serum FSH and inhibin B levels (r = −0.93; p < 0.001) was found. In the serum of SCO patients a slight increase in less glycosylated FSH isoforms was found (6.7 ± 0.6% versus 3.6 ± 0.3%; p < 0.05). No mutations of the FSHR were observed in SCO patients.

We conclude that the spermatogenic failure observed in infertile patients with SCO histology and elevated FSH serum levels can be explained neither by a change in FSH bioactivity nor by mutations in the FSHR. The slight change in the FSH glycosylation pattern is probably related to higher hormonal secretion rates in SCO patients. The inverse relationship between serum FSH and inhibin B points to an intact endocrine testicular–pituitary circuit responsible for the compensatory increase of FSH in SCO.
Alpha‐glucosidase activity in the rat epididymis under different physiological conditions
Authors: KALLA N. R. , KAUR S. , UJWAL N. , MEHTA U. , JOOS H. , FRICK J.
Published: November 2003

The estimation of alpha‐glucosidase activity in semen is widely used as a marker of epididymal function. In the present studies, glucosidase activity was evaluated in the different segments of the rat epididymis under various physiological conditions. In addition, the effect of two known male antifertility agents, gossypol and alpha‐chlorohydrin, on enzyme activity was evaluated. Enzyme activity was absent from the epidiymis of rats aged 10 and 20 days but became detectable at 30 days of age when the adult pattern of distribution (highest activity in the caput epididymis) was established. Enzyme activity was reduced significantly in all segments of the epididymis at 7 days after castration and a significant decrease in activity was also observed following the administration of either gossypol or alpha‐chlorohydrin. These findings are consistent with a role for alpha‐glucosidase in sperm maturation in the epididymis.
Experimental uremia in male rats: effect of interval between partial nephrectomies on testicular function
Authors: SASAGAWA I. , ADACHI Y. , TOMARU M. , TATENO T. , IIJIMA Y. , KUBOTA Y. , NAKADA T.
Published: November 2003

Testicular function in stepwise‐nephrectomized rats, with a different interval between the two operations, was studied suing male Wistar rats. Serum levels of urea nitrogen and creatinine in stepwise‐nephrectomized rats were significantly elevated compared to those in sham‐operated rats ( p < 0.001). With a 1‐day interval between the two operations, these concentrations were considerably higher ( p < 0.001) than those in 7‐day interval rats. While serum LH levels were significantly reduced ( p < 0.001) in 1‐day interval rats, FSH levels in this group were considerably higher ( p < 0.001) than in other groups. Serum concentrations of androstenedione in 1‐day interval rats were significantly suppressed compared to other groups ( p < 0.01). Serum testosterone levels in stepwise‐nephrectomized rats were considerably lower ( p < 0.001) than in sham‐operated rats. It is assumed that testicular function in stepwise‐nephrectomized rats is influenced by the interval between the two operations.
Increased testosterone production in vitro by Leydig cells from rats with severe autoimmune orchitis
Authors: SUESCUN M. O. , CALANDRA R. S. , LUSTIG§ L.
Published: November 2003

We have previously observed (M. O. Suescun et al., 1994, Journal of Andrology, 15, 442–448) that rats with autoimmune orchitis (EAO) exhibit increased testosterone production in vitro by isolated testes. The aim of the present study was to determine whether the increase in testosterone production correlated with an enhanced number of Leydig cells and/or enhanced steroidogenic capacity per Leydig cell. For this purpose, EAO was induced in adult Sprague‐Dawley rats by active immunization with testicular homogenate and adjuvants. At 80 days after the primary immunization, 60% of rats presented with severe testicular damage characterized by sloughing of the seminiferous epithelium, seminiferous tubule atrophy and interstitial mononuclear cell infiltration. At 160 days after the first immunization, testicular lesions were more severe. A morphometric study, by light microscopy, showed an increase in the number of Leydig cells in rats with EAO (45% increase at 80 days and 50% at 160 days). By electronmicroscopy, testicular sections of rats with EAO revealed the presence of numerous Leydig cells closely associated with macrophages. Most Leydig cells exhibited ultrastructural features of active steroid secreting cells.

The steroidogenic capacity of Percoll‐purified Leydig cells from testes of rats with EAO, killed at 80 and 160 days, was evaluated. Leydig cells from rats with EAO exhibited an enhanced steroidogenic response to hCG in vitro at 80 days (38%) and an increase in basal (77%) and post‐hCG testosterone production (115%) at 160 days compared to controls. However, these cells were less sensitive to hCG. In conclusion, the results indicate that the enhancement of in‐vitro testosterone production observed in rats with EAO is accounted for both by the increased number of Leydig cells and by the increased testosterone production of each Leydig cell.
Toxicity of ornidazole and its analogues to rat spermatozoa as reflected in motility parameters
Authors: BONE W. , YEUNG C. H. , SKUPIN R. , HAUFE G. , COOPER T. G.
Published: November 2003

Ornidazole, a 5‐nitro‐imidazole derivative, has contraceptive properties in rats. As some ornidazole passes through the body unmetabolized after administration, the aim of this study was to investigate if ornidazole itself has a direct effect on sperm motility and whether these effects are limited or potentiated by the epididymal epithelium or structural changes to the molecule. Cauda epididymal spermatozoa or cauda epididymal tubules were incubated with ornidazole or ornidazole analogues, and motility parameters were subsequently measured by means of a computer‐assisted sperm analysis (CASA) system. Incubation of spermatozoa in 2.5 mmol/L ornidazole for 4 h reduced their motility significantly, whereas incubation of epididymal tubules for 8 h in 10 mmol/L ornidazole was required to alter the velocity parameters of the enclosed spermatozoa upon release, suggesting that extratubular non‐metabolized ornidazole can participate in inhibiting the motility in vivo. The in vitro toxicity of ornidazole derivatives depends on the halogen present and on the position of the nitro‐group. The putatively inactive (R)‐ and the active (S)‐ornidazole exhibited equivalent depression of sperm motility by direct incubation. This observation, and the differences between the in vitro and the in vivo efficacies of various ornidazole analogues, indicates distinct mechanisms of motility inhibition in the two experimental systems.
Effects of vasoactive intestinal peptide (VIP) on the testicular vasculature of the rat
Authors: LISSBRANT E. , BERGH A.
Published: November 2003

Using laser Doppler flowmetry, the effects of unilateral intratesticular injection of vasoactive intestinal peptide (VIP) on testicular blood flow and mean arterial blood pressure were studied in anaesthetized adult rats. At doses of 50 and 500 ng, VIP increased blood flow by 29 ± 8 and by 77 ± 25% ( p < 0.05), respectively (means ±  SEM) at 5 mm, but not at 15 mm, from the injection site. Blood pressure was not significantly affected by 50 ng, but was slightly reduced (by −8 ± 2%) after treatment with 500 ng VIP. The highest dose of VIP (5 μg) reduced blood pressure (by −30 ± 9%), and decreased blood flow at 15 mm, but not at 5 mm, from the injection site. It is concluded that VIP can act as a vasodilator in the rat testis.
Further studies on the lobar heterogeneity in response to coumarin‐mediated hepatotoxicity
Authors: Jack Katherine R. , Kho Karina , Thomas Norman W. , Fry Jeffrey R.
Published: November 2003

A randomized sampling protocol coupled with quantitative morphometry has been used to evaluate the inter‐lobe variation in centrilobular hepatic necrosis in the mouse, and periportal hepatic necrosis in the β‐naphthoflavone‐induced rat, both in response to treatment with coumarin. The results of these studies indicate a random inter‐lobe variation in xenobiotic‐mediated hepatotoxicity.