bluuebunny/crossref_metadata_2025 huggingface dataset:
Intragenomic heterogeneity of a ribosomal DNA spacer (ITS2) varies regionally in the neotropical malaria vector Anopheles nuneztovari (Diptera: Culicidae)
Authors: Onyabe D. Y. , Conn J. E.
Published: March 2003

We investigated intragenomic heterogeneity of ITS2 within twenty individual Anopheles nuneztovari (subgenus Nyssorhynchus) from five geographical localities in the neotropics (three from Brazil and one each from Colombia and Venezuela) by cloning and sequencing PCR‐amplified copies of this spacer. Intragenomic heterogeneity was observed in thirteen of twenty mosquitoes of both sexes from all localities. As estimated by uncorrected P, however, mean sequence divergence was greater in mosquitoes from Brazil (PR = 0.0100, BL = 0.0196, AB = 0.0182) than in those from Venezuela (SO = 0.0026) or Colombia (SI = 0.0078). Sequence divergence per genome was significantly higher in mosquitoes from Brazil than in those from SO and SI. In fact, divergence among ITS2 variants within single mosquitoes from the Brazilian localities was often as great as that between localities. Similarly, the number of variants per mosquito was significantly greater in Brazil (maximum of six variants) than in both SO and SI (maximum of two variants). These results indicate that homogenization of ITS2 has proceeded to a greater extent in SO and SI than in the localities in Brazil. The differences in intragenomic heterogeneity between both SO and SI versus the Brazilian localities probably reflect either differences in population‐level processes such as gene flow and genetic drift, or the fact that these localities may represent two or more cryptic species, as suggested by other studies.
Conserved features at the 5′ end of Drosophila R2 retrotransposable elements: implications for transcription and translation
Authors: George J. A. , Eickbush T. H.
Published: March 2003

R2 non‐LTR retrotransposable elements insert site‐specifically into the 28S ribosomal genes of insects. The sequence of the 5′ end of full‐length R2 elements from thirteen species of Drosophila were compared. Sequences within the 5′ untranslated region (5′ UTR) revealed little to suggest the presence of a promoter. Protein translation initiates within the 5′ UTR and requires the bypassing of a highly conserved termination codon preceding the single R2 open reading frame. This bypassing probably involves a conserved RNA secondary structure which brings a potential initiation codon into close proximity to this termination codon. The most highly conserved sequence within the 5′ UTR has properties similar to internal ribosomal entry sites. Based on these findings, we propose that R2 elements are co‐transcribed with the 28S gene and are translated as part of a large ribosomal subunit.
Four serine proteinases expressed in Manduca sexta haemocytes
Authors: Jiang H. , Wang Y. , Kanost M. R.
Published: March 2003

Several putative serine proteinases were detected in Manduca sexta larval plasma by labelling with radio‐active diisopropyl fluorophosphate. To begin to identify and characterize such enzymes, a polymerase chain reaction was carried out using haemocyte cDNA as template and primers designed to amplify conserved sequences from serine proteinases. Four serine proteinase cDNA fragments were cloned. These were used as probes to screen an M. sexta larval haemocyte cDNA library to obtain full‐length clones encoding haemocyte proteinases 1–4 (HP1, HP2, HP3 and HP4). HP1 and HP2 contain an aminoterminal ‘clip’ domain similar to those found in horse‐shoe crab clotting enzyme and clotting factor B and also in the Drosophila melanogaster proteinases snake and easter. HP3 and HP4 are most similar to proteinases from mammalian leucocytes. HP1 and HP2 are both present in plasma. HP1 is expressed in haemocytes (granular cells and oenocytoids) and not in fat body. HP2 is expressed in fat body and in granular haemocytes, plasmatocytes and oenocytoids. After injection of larvae with bacteria, the level of HP2 mRNA decreased in haemocytes and increased in fat body.
Molecular cloning and expression of two hexamerin cDNAs from the mosquito, Aedes aegypti
Authors: Crampton J. M. , James A. A. , Gordadze A. V. , Korochkina S. E. , Zakharkin S. O. , Norton A. L. , Beneš H.
Published: March 2003

Fourth‐instar larvae of Aedes aegypti synthesize two types of hexamerins, Hexamerin‐1 (AaHex‐1) and Hexamerin‐2 (AaHex‐2), whose subunits are distinguished by different methionine and aromatic amino acid contents. In early female pupae only the methionine‐rich AaHex‐1γ subunit accumulates to two‐fold higher levels than in males. To investigate the relationship between hexamerin structure and the roles of Hex‐1 and Hex‐2 during mosquito development and reproduction, we have cloned and sequenced cDNAs encoding the AaHex‐2α, ‐2β and AaHex‐1γ subunits. Comparison with other insect hexamerins revealed that the Aedes Hex‐1 and Hex‐2 proteins belong, respectively, to the two hexamerin subfamilies previously defined for brachyceran Diptera. Probes specific for the Hex‐2α and Hex‐1γ transcripts showed that expression of both genes follows the same developmental timetable. However, greater Hex‐1γ mRNA accumulation may contribute to the higher levels of Hex‐1γ protein in early female pupae.
Microsatellite analysis of sperm admixture in honeybee
Authors: Franck P. , Coussy H. , Le Conte Y. , Solignac M. , Garnery L. , Cornuet J.‐M.
Published: March 2003

Sperm usage was investigated in an instrumentally inseminated honeybee queen. Her progeny were examined in the first 3 months of the egg‐laying period using a microsatellite marker. Frequencies of different subfamilies differed significantly from one month to another. However, there was no evidence for sperm displacement or sperm precedence of a specific male in the worker progeny. The variance of subfamily proportions decreased over time suggesting that sperm admixture in the spermatheca was incomplete at the beginning of the egg‐laying period of the queen and improved progressively during the first months after mating.
A locust type 1 ADP‐ribosylation factor (lARF1)* is 100% identical in amino acid sequence to Drosophila ARF1 despite obvious DNA sequence divergence
Authors: Hannan F. , Evans P. D.
Published: March 2003

The cDNA of a type 1 ADP‐ribosylation factor (ARF) from the desert locust, Locusta migratoria was cloned, sequenced and compared to ARF1 genes of other species. The locust ARF1 protein is 100% identical with the ARF1 protein of the fruit fly Drosophila melanogaster even though the DNA sequences are only 79% identical. The significance of this finding in relation to the considerable evolutionary distance between hemimetabolous and holometabolous insects is discussed.
Wolbachia in the Asian rice gall midge, Orseolia oryzae (Wood‐Mason): correlation between host mitotypes and infection status
Authors: Behura S. K. , Sahu S. C. , Mohan M. , Nair S.
Published: March 2003

Using a PCR‐based method, we detected Wolbachia in the Asian rice gall midge. Furthermore, results showed that all females across all biotypes are infected with Wolbachia. However, all male flies are not infected and show different infection frequency in different biotypes. We have also identified three mitotypes, in the rice gall midge, based on DraI restriction pattern of a portion of the 12S rRNA gene that was PCR amplified using primers specific to this gene. All the females and infected male flies had type 1 mtDNA while uninfected males showed only type 2 or 3 mtDNA. Inheritance patterns of mtDNA revealed the existence of a correlation between mtDNA type and Wolbachia infection in the Asian rice gall midge. Evidence for paternal inheritance of mtDNA in Wolbachia‐free gall midge is also presented.
Effect of baculovirus infection on the mRNA and protein levels of the Spodoptera frugiperda eukaryotic initiation factor 4E
Authors: van Oers M. M. , van der Veken L. T. J. N. , Vlak J. M. , Thomas A. A. M.
Published: March 2003

The cDNA sequence of eukaryotic translation initiation factor eIF4E was derived from a Spodoptera frugiperda cDNA library. Eight tryptophan residues, typical for eIF4E, are strictly conserved in the encoded 210 amino acid protein. A polyclonal antiserum detected a 26 kDa protein in lepidopteran cell lines, but not in dipteran cells. Sf21 cells have a single eIF4E gene copy, which is transcribed into a 1500 nt transcript. Infection with AcMNPV resulted in a decrease in eIF4E mRNA starting between 12 and 24 h postinfection (p.i.), while reduced eIF4E protein levels were observed at 48 h p.i. Two forms of eIF4E were recognized that differed in their iso‐electric point, of which the relative abundance did not change during infection. Mutagenesis experiments using recombinant baculoviruses revealed that the variation in mobility between these two forms did not result from a difference in the phosphorylation state of Ser‐202, the serine residue that corresponds with the eIF4E phosphorylation site in mammalian eIF4E.
Extrachromosomal RNA–DNA complex containing long telomeric repeats in chironomids
Authors: Rosén M. , Kamnert I. , Edström J.‐E.
Published: March 2003

We have analysed an extracted RNase sensitive fraction containing telomeric repeat sequences in the telomerase negative dipteran Chironomus tentans. It shows a slow and well‐defined electophoretic migration corresponding to > 20 kb and is sensitive not only to RNase, but also to DNase. It hybridizes to both strands of the telomeric repeat with about equal intensities. DNA is probably the dominant component since the fraction is only slightly heavier than genomic DNA in isopycnic gradients but considerably lighter than RNA. It can, nevertheless, be shown to incorporate tritiated uridine. The material might represent another example of extrachromosomal telomeric repeats in telomerase negative cells.
cDNA cloning, characterization and gene expression of nitric oxide synthase from the silkworm, Bombyx mori
Authors: Imamura M. , Yang J. , Yamakawa M.
Published: March 2003

Molecular cloning and nucleotide sequencing of cDNA encoding Bombyx mori nitric oxide synthase (BmNOS) was conducted to analyse its possible role in insect immunity. The amino acid sequence deduced from the BmNOS cDNA showed 84%, 54% and 53% identity with those of NOSs from Manduca sexta, Drosophila melanogaster and Rhodonius prolixus. Recombinant BmNOS produced in insect cells using baculovirus was found to require NADPH, Ca2+, calmodulin and tetrahydrobiopterin (BH4) for its activity. The BmNOS gene was constitutively expressed at a low level in the larval fat body, haemocyte, Malpighian tubule and midgut, and adult antenna, and induced strongly in the fat body by lipopolysaccharide (LPS), suggesting that the BmNOS gene plays different physiological roles in different tissues. Injection of NO donors that produce NO in vivo induced the gene expression of an antibacterial peptide, cecropin B, strongly suggesting that NO produced by BmNOS following LPS stimulation is involved in signal transduction as a signalling molecule for immune gene expression.
Nested retrotransposons on the W chromosome of the wild silkworm Bombyx mandarina
Authors: Abe H. , Sugasaki T. , Terada T. , Kanehara M. , Ohbayashi F. , Shimada T. , Kawai S. , Mita K. , Oshiki T.
Published: March 2003

The W chromosome of the silkworms Bombyx mori or B. mandarina is recombinationally isolated from the Z chromosome and the autosomes. We previously characterized a female‐specific randomly amplified polymorphic DNA (RAPD), designated W‐Yamato, derived from the W chromosome of the wild silkworm Bombyx mandarina. To further analyse the W chromosome of B. mandarina, we obtained a lambda phage clone that contains the W‐Yamato RAPD sequence and sequenced the 16.7 kb DNA insert. We found that this DNA comprises a nested structure of at least seven elements: six retrotransposons and one transposable element‐like sequence. The transposable element‐like sequence is inserted into a micropia‐like retrotransposon (Karate). The Karate and the non‐long terminal repeat (non‐LTR) retrotransposon BMC1 are inserted into a 412‐like retrotransposon (Judo). Furthermore, this Judo, and two non‐LTR retrotransposons (Kurosawa and Kendo) are inserted into a Pao‐like retrotransposon (Yamato). These results indicate that the retrotransposons inserted into the W chromosome are not efficiently removed but accumulate gradually as strata without recombination.
The period gene in two species of tephritid fruit fly differentiated by mating behaviour
Authors: An X. , Wilkes K. , Bastian Y. , Morrow J. L. , Frommer M. , Raphael K. A.
Published: March 2003

The period gene is important for the generation and maintenance of biological rhythms. It served as an ideal candidate for the investigation of the mating time isolation between two sibling Queensland fruit fly species, Bactrocera tryoni and Bactrocera neohumeralis. We have isolated the homologues of the period gene in the two species, and show that their putative amino acid sequences are identical. No length polymorphism was detected in the Thr‐Gly repeat region. per mRNA expression, assayed in light–dark diurnal conditions, displayed circadian oscillation in both the head and abdomen of B. tryoni and B. neohumeralis, with the same cycling phase. An alternatively spliced intron was identified in the 3′ untranslated region. The effect of temperature on the splicing and mRNA expression was examined.
Isolation and characterization of a neprilysin‐like protein from Venturia canescens virus‐like particles
Authors: Asgari S. , Reineke A. , Beck M. , Schmidt Otto
Published: March 2003

Maternal protein secretions from endoparasitoid wasps are evolutionary adaptations to regulate host physiology as part of an extended wasp phenotype. Virus‐like particles (VLPs) produced in the calyx region of Venturia canescens wasps are involved in immune evasion of the developing parasitoid inside the host. In contrast to polydnaviruses (PDVs), VcVLPs are devoid of any nucleic acids. To understand the role of these particles in the regulation of host physiology and phylogenetic relationship between VLPs and PDVs, it is essential to identify particle proteins. In this paper, we describe the isolation and molecular cloning of a neprilysin‐like gene (VcNEP) coding for a 94 kDa VcVLP protein and discuss its possible role in host regulation.
Developmental profiles and ecdysone regulation of the mRNAs for two ecdysone receptor isoforms in the Mediterranean fruit flyCeratitis capitata
Authors: Verras M. , Gourzi P. , Zacharopoulou A. , Mintzas A. C.
Published: March 2003

Using 5′ RACE with specific primers for the ecdysone receptor B1 isoform of the Mediterranean fruit fly (medfly),Ceratitis capitata, we isolated a cDNA clone encoding the specific region of the medfly ecdysone receptor A isoform (CcEcR‐A). The CcEcR‐A‐specific region was very similar to the EcR‐A‐specific region ofDrosophila melanogasterand less similar to the EcR‐A‐specific regions of Lepidoptera. The developmental expression of both CcEcR‐A and CcEcR‐B1 mRNAs was studied in whole animals, salivary glands and ovaries by RT‐PCR, using isoform‐specific primers. Both CcEcR mRNAs are present in very early embryos, decrease to very low levels during the first hours of embryogenesis and are highly expressed in all consequent embryonic stages. During metamorphosis both isoforms are present showing two peaks; the first at the larval–prepupal transition and the second during the second half of prepupal development. These peaks are correlated with the two puffing cycles and the two major 20‐hydroxyecdysone (20E) increases that occur during medfly metamorphosis. CcEcR‐B1 mRNA was directly induced in larval salivary glandsin vitroby 20E, even at very low concentrations of the hormone, while CcEcR‐A mRNA was slightly induced only by high 20E concentrations and in the absence of a protein synthesis inhibitor. During oogenesis, the CcEcR mRNAs were expressed synchronously, peaking at the beginning of both previtellogenic and vitellogenic phases.
Sealing ability of super EBA and Dyract as root‐end fillings: a study in vitro
Authors: Bohsali  , Pertot  , Hosseini  , Camps
Published: March 2003

The purpose of this study was to compare, in vitro, the sealing ability of Super EBA and a compomer, Dyract, as root‐end filling materials. Forty‐eight single‐rooted human teeth were cleaned, shaped and obturated with gutta‐percha. The root apices were resected and root‐end cavities were prepared. Twenty teeth were retrofilled with Super EBA and Dyract; eight teeth served as positive and negative controls. Half of the teeth in each group were immersed in basic fuschin for 4 weeks, the other half for 12 weeks. The teeth were then embedded in resin, sectioned, and the maximum extent of dye penetration measured. Statistical analysis (
ANOVA) did not reveal a significant difference between the two materials at 4 weeks. At 12 weeks, the extent of dye penetration was statistically significant with Super EBA leaking more than Dyract (P= 0.002). Moreover, the extent of the dye penetration was statistically significantly different for Super EBA between the 4‐ and 12‐week groups (P= 0), whereas no such difference was found for Dyract. Thus, the sealing ability of Dyract was found to be better than Super EBA at 12 weeks.
Quantitative analysis of lymphocytes and their subsets in periapical lesions
Authors: Alavi  , Gulabivala  , Speight
Published: March 2003

The relative proportions of lymphocytes and their subsets in periapical lesions associated with untreated teeth and endodontically treated teeth were compared. Nine periapical lesions associated with previously untreated teeth and six persistent lesions associated with previously root treated teeth which had good quality root canal fillings and coronal seals were selected from a total of 41 samples. Clinical and radiographic features of each lesion were recorded. Serial frozen sections were stained using immunohistochemical methods and monoclonal antibodies against CD20, CD3, CD4 and CD8 to identify B, T, T helper (Th) and T suppressor (Ts) lymphocytes, respectively. Ten microscopic fields, representing the most dense cellular inflammatory infiltrate were selected per specimen and cell numbers were estimated, as a proportion of lesion area, using a point counting method. The periapical lesions associated with untreated teeth had a denser inflammatory cell infiltrate. The proportion of total lymphocytes was significantly higher in the untreated group of lesions (P < 0.01). The proportions of B (P < 0.01), T (P < 0.001) and Th cells (P < 0.01) were significantly higher in untreated teeth. The ratios of Th/Ts cells (P < 0.05) and T/total lymphocytes (P < 0.01) were also significantly different between the two types of lesion. The results show a difference in the inflammatory cell infiltrate and relative proportions of T, B and T helper cells in the two groups of lesions. This indicates that future studies of periapical lesions should take into account the clinical history of the associated teeth.
Scanning electron microscope study on the efficacy of root canal wall debridement of hand versus Lightspeed instrumentation
Authors: Bechelli C. , Orlandini S. Zecchi , Colafranceschi M.
Published: March 2003

Bechelli C, Zecchi Orlandini S, Colafranceschi M. Scanning electron microscope study on the efficacy of root canal wall debridement of hand versus Lightspeed instrumentation. International Endodontic Journal, 32, 484–493 1999.

Aim The aim of this in vitro study was to compare the efficacy of root canal wall debridement following hand versus LightSpeedTM instrumentation.

Methodology Twenty recently extracted single‐rooted teeth were paired and randomly placed into two treatment groups of 10 teeth each. In group 1, a step‐back instrumentation without initial coronal flaring with stainless steel Hedstroem files was used; group 2 was instrumented with Ni‐Ti LightSpeedTM instru‐ments. Both groups had the same irrigation regimen: 2.5% NaOCl and a 15% EDTA solution. The teeth were then decoronated and each root split longitudinally into two halves to be examined using the scanning electron microscope (SEM). The presence of superficial debris and smear layer was evaluated by a standardized grading system, and the resulting scores submitted to nonparametric statistics.

Results Under the conditions of this study, the removal of superficial debris was generally excellent with both canal preparation techniques. Both techniques resulted in variable presence of residual smear layer, with a canal wall covered by smear layer as the predominant characteristic. Generally, the amount of smear layer was greater in the apical than in the middle third of the root, however, this difference was statistically significant (P 0.005) only in hand‐instrumented teeth. The use of LightSpeedTM instruments was associated with significantly more (P 0.05) smear layer presence in the middle region of the root when compared with hand instrumentation. In addition, less smear layer was present in the apical region following LightSpeedTM instrumentation than stainless steel hand files, but this difference was not statistically significant. Differences in debridement between the two halves of the same root were more evident with LightSpeedTM than manual instrumentation, however, there was no statistical significance.

Conclusions It may be inferred that the choice between hand and LightSpeedTM instrumentation should be based on factors other than the amount of root canal debridement, which does not vary significantly according to the instruments used.
Effects of pulsed Nd:YAG laser irradiation on smear layer at the apical stop and apical leakage after obturation
Authors: Goya C. , Yamazaki R. , Tomita Y. , Kimura Y. , Matsumoto K.
Published: March 2003

Aim

This study evaluated the removal of smear layer at the apical stop by pulsed Nd:YAG laser irradiation with or without black ink, and the degree of apical leakage after obturation in vitro.

Methodology

Sixty extracted human single‐rooted teeth were used in this study. The teeth were instrumented up to a size 40 K‐file, and then divided into three groups of 20 teeth each: group 1 was unlased as a control group; group 2 was treated with a laser; group 3 was treated with a laser and black ink. The laser was operated at 2 W and 20 pp for 2 s, and irradiation was performed twice with a 30‐s interval. In each group, 10 teeth for the leakage study were obturated and immersed in rhodamine B solution for 48 h at 37 °C, and the others were used for evaluation of remaining smear layer. All teeth were bisected longitudinally and observed by stereoscopy or scanning electron microscopy.

Results

The smear layer in the laser‐treated groups almost melted or evaporated, and was removed significantly compared with the control group (P < 0.05). Leakage was observed in 60% of samples in group 1 and in 20% of samples in group 2. No leakage was observed in group 3, which was significantly different from the control (P < 0.05).

Conclusions

These results suggest that pulsed Nd:YAG laser irradiation with black ink increases the removal of smear layer compared with that without black ink, and reduces apical leakage after obturation significantly.
Sealer distribution in root canals obturated by three techniques
Authors: Wu M.‐K. , Özok A. R. , Wesselink P. R.
Published: March 2003

Aim

The aim of this study was to observe sealer distribution in root canals filled by different root filling techniques.

Methodology

AH26 (0.05 mL) dyed with carbon black powder was placed into the prepared root canals of maxillary central incisors using a lentulo spiral. Thereafter the canals were obturated using three different gutta‐percha root‐filling techniques. Horizontal sections were cut in the apical and middle portions of the filled canals. Images of the cross sections were scanned and the percentage of sealer coated canal perimeter (PSCP) was measured using a computer digital imaging system.

Results

At 3 mm from the apex, the PSCP after lateral condensation was similar to that after vertical condensation (P > 0.05). At 6 mm from the apex, however, the PSCP was significantly higher after lateral condensation than after vertical condensation (P < 0.05). At both levels the PSCP was significantly higher after single cone (no condensation) than after the other two condensation techniques (P < 0.0001).

Conclusions

Sealer may be removed from the canal wall by the condensation procedures.
The effect of root canal preparation on microleakage within endodontically treated teeth: an in vitro study
Authors: Von Fraunhofer J. A. , Fagundes D. K. , McDonald N. J. , Dumsha T. C.
Published: March 2003

Aim

The purpose of this study was to evaluate the effects of smear layer and canal instrumentation on leakage in root‐filled teeth.

Methodology

Six groups (n = 12) of freshly extracted human canines and premolars with closed apices and single roots were used. Groups A, B, C, and D were instrumented with engine‐driven rotary nickel‐titanium MCXIM files and Groups E and F were instrumented with conventional stainless steel hand files. Groups A, C, and E were flushed with 3.0 mL of 17.0% REDTA to remove the smear layer prior to obturation. All teeth were flushed with 5.25% NaOCl, then obturated with AH‐26 sealer and either the lateral condensation (Groups C–E) or thermomechanical compaction technique (Groups A and B). Copper wire was placed coronally in contact with the gutta‐percha in each tooth and, after immersion in 0.9% NaCl solution, a 10 volt dc voltage was connected between each tooth and a stainless steel electrode. The current flow in the circuit was observed for 45 days. One way ANOVA and Duncan’s Multiple Range Test were used to compare Groups A–F at time intervals of 10, 20, 30 and 45 days and identify statistically significant differences.

Results

Significantly less microleakage occurred when the smear layer was removed and when the canals were obturated with thermoplasticized gutta‐percha. Canals instrumented with engine‐driven NiTi files exhibited less leakage than hand‐instrumented canals irrespective of obturation method.

Conclusions

Smear layer removal is beneficial to root canal sealing. Obturation with thermoplasticized gutta‐percha provides a superior seal whilst canal instrumentation with engine‐driven NiTi files reduces the extent of microleakage in root canals.
Identification of root canals in molars by tuned‐aperture computed tomography
Authors: Nance R. , Tyndall D. , Levin L. G. , Trope M.
Published: March 2003

Aim

To compare the tuned‐aperture computed tomography system of imaging to conventional D‐speed film for their ability to identify root canals in extracted human molars.

Methodology

Thirteen maxillary and six mandibular human molars were mounted in acrylic blocks to simulate clinical conditions by surrounding the teeth with a radiodense structure. The teeth were then imaged with conventional D‐speed film using a standard paralleling technique, and with a modified orthopantomograph OP100 machine using a Schick no. 2 size CCD sensor as the image receptor. The source images were registered and TACT slices were generated using TACT Workbench™ Software. Three observers were asked to identify the number of canals in the conventional film group and the TACT image group using specific criteria. Ground truth was established by cross‐sectioning the teeth at the coronal, middle, and apical thirds of the roots and directly visualizing the root canal morphology.

Results

TACT imaging detected 36% of 4th canals in maxillary molars and 80% of third canals in mandibular molars. Conventional film detected 0% of fourth canals in maxillary molars and 0% of third canals in mandibular molars. The differences in canal detection between the two techniques were statistically significant (Wilcoxon matched pair sign rank test, P = 0.001).

Conclusions

In this study, the TACT system of digital imaging was superior to conventional film in the detection of root canals in human molars and may be useful for the detection of root canals that will probably be missed upon conventional X‐ray examination.
Apical inflammatory root resorption: a correlative radiographic and histological assessment
Authors: Laux M. , Abbott P. V. , Pajarola G. , Nair P. N. R.
Published: March 2003

Aim

To assess the reliability of routine single radiographs in the diagnosis of inflammatory apical root resorption by correlating the radiographic and histological findings.

Methodology

The material comprised serial and step serial sections of plastic‐embedded root‐apices with attached apical periodontitis lesions that were prepared for a previous study and the diagnostic radiographs. The histological sections of 114 specimens were analysed by light microscopy and categorized into three groups: (i) those without any resorption (0); (ii) those with moderate resorption (+); and (iii) those with severe resorption (+ +). The radiographs were examined by a separate examiner and graded with a similar categorization of no resorption (0); moderate (+); and severe (+ +) apical resorption.

Results

Radiographically, 19% of the teeth were diagnosed as having apical inflammatory root resorption, whereas histologically, 81% of the teeth revealed apical inflammatory root resorption. A correlative radiographic and histological assessment (n = 104) revealed a coincidence of diagnosis in 7% of the specimens and noncoincidence of diagnosis in 76% of the specimens.

Conclusions

The results indicate that routine single radiographs are not sufficiently accurate or sensitive to consistently diagnose apical root resorptive defects developing as a consequence of apical periodontitis.
The influence of ultrasound on the retention of cast posts cemented with different agents
Authors: Gomes A. P. M. , Kubo C. H. , Santos R. A. B. , Santos D. R. , Padilha R. Q.
Published: March 2003

Aim

The aim of this study was to evaluate the influence of ultrasound during the removal of posts cemented with either zinc phosphate cement, glass ionomer cement or resin cement.

Methodology

Eighty‐four single‐rooted teeth were prepared and after cementation of cast posts, they were randomly divided into six groups of 14. Groups 1, 2 and 3 did not receive ultrasonic vibration, whilst groups 4, 5 and 6 received ultrasonic vibration for 10 min. The force necessary for post removal was determined using a universal testing machine. Results were statistically analysed using anova and Tukey tests (5%).

Results

The application of ultrasonic vibration reduced the retention provided by zinc phosphate and glass ionomer cements by 39% and 33%, respectively.

Conclusions

A statistically significant reduction in the force necessary to remove posts cemented with zinc phosphate and glass ionomer cements occurred following application of ultrasound. The application of ultrasonic vibration did not influence the retention of cast posts cemented with resin cement.
Does the first file to bind correspond to the diameter of the canal in the apical region?
Authors: Wu M.‐K. , Barkis D. , Roris A. , Wesselink P. R.
Published: March 2003

Aim The aim of this study was to determine whether the first file that binds at the working length corresponds to the canal diameter.

Methodology Two similar groups (n = 10) of mandibular premolars with curved canals were selected on the basis of their morphology. Following access and pulp tissue removal, the first instrument that bound in each canal at the working length was determined. In one group the instrument used was a K‐file, in the other group a Lightspeed instrument was used. After fixing the instruments in place, the apices were ground to the level of the working length and the diameters of both the instrument and the apical canal were recorded.

Results In 75% of the canals, the instruments bound at one side of the wall only; in the other 25%, the instrument did not contact the wall. In 90% of the canals, the diameter of the instrument was smaller than the short diameter of the canal; this discrepancy was up to 0.19 mm. No significant difference in discrepancy was found between instruments (P > 0.05).

Conclusions Neither the first K‐file nor the first Lightspeed instrument that bound at the working length accurately reflected the diameter of the apical canal in curved mandibular premolars. It is uncertain whether dentine can be removed from the entire circumference of the canal wall by filing the root canal to three sizes larger than the file that binds first.
Percentage of normal sperm heads is significantly increased by Percoll separation of semen
Authors: GRAVANCE  , CHAMPION  , SAX‐GRAVANCE  , CASEY
Published: March 2003

The purpose of this study was to assess objectively the effects of Percoll separation on human sperm head morphometry. Semen samples were washed and smears were prepared on slides. An aliquot of each sample was centrifuged on a Percoll gradient and spermatozoa were prepared on slides. Dimensions of sperm heads from each sample were assessed by computer‐aided sperm head morphometry analysis and manual sperm morphology was assessed for each sample. The percentage of normal sperm heads and morphometric dimensions from washed and post‐Percoll separated samples were compared across all men by a paired t‐test. Correlations between normal sperm head morphometry and manual sperm morphology were assessed in washed and Percoll‐separated samples. The percentage of normal sperm head morphometry was significantly ( p < 0.001) higher in Percoll‐separated samples than in washed samples (23.6 vs. 12.6%). No differences ( p > 0.1) in mean sperm head measurements were detected between washed samples and Percoll‐separated samples. Coefficients of variation for mean sperm head measurements were significantly lower in Percoll‐separated samples. No correlation ( p > 0.1) in percentage normal was found between computer‐assisted sperm head morphometry and manual morphology for washed and post‐Percoll samples. These results indicate that percentage normal sperm head morphometry is increased by Percoll separation. While sperm head dimensions were unchanged, sample variability was decreased.
Apoptosis precedes detachment of germ cells from the seminiferous epithelium after hormone suppression by short‐term oestradiol treatment of rats
Authors: BLANCO‐RODRÍGUEZ  , MARTÍNEZ‐GARCÍA
Published: March 2003

Spermatogenesis is a highly synchronized process in which FSH and testosterone are considered the major regulators. Nevertheless, the mechanism by which these hormones act on germ cells is unclear. Cell adhesion has been proved to play an essential role in the regulation of programmed cell death in epithelial cells and it is now known that FSH and testosterone withdrawal results in the triggering of apoptosis as well as germ cell detachment from the seminiferous epithelium. Therefore, it seemed important to investigate whether the triggering of apoptosis in germ cells by experimental hormone suppression occurred as a result of their previous detachment from the epithelium. To achieve this goal, adult male rats were injected with 50 μg oestradiol benzoate for 1, 2, 3, 4, 5 or 10 days to suppress gonadotrophin secretion and thus intratesticular levels of testosterone. Germ cell apoptosis was assessed in testes from these animals by in situ 3′ end‐labelling of DNA fragments and quantified in seminiferous tubule sections at stages VII–VIII. Serial sections throughout the epididymides from these animals were analysed to search for immature germ cells detached from the epithelium. These cells were scored and quantified in non‐consecutive randomly selected epididymal sections. Our data indicate that the triggering of apoptosis in germ cells precedes germ cell detachment, suggesting that detachment of germ cells from the epithelium, occurring after hormone suppression, is not necessary for germ cell apoptosis.
Screening for Chlamydiatrachomatis and Ureaplasmaurealyticum infection in semen from asymptomatic male partners of infertile couples prior to in vitro fertilization
Authors: Levy  , Layani‐Milon  , Giscard D’Estaing  , Najioullah  , Lornage  , Aymard  , Lina
Published: March 2003

In a prospective study, the prevalence of infection with Chlamydia trachomatis and Ureaplasma urealyticum was evaluated in the semen of 92 asymptomatic male partners of infertile couples using polymerase chain reaction and culture, respectively. The results were compared with the detection of serologically specific antibodies. U. urealyticum and C. trachomatis were detected in 12 (13%) and 10 (10.8%) of the tested ejaculates, respectively. One mixed infection was detected.

No correlation was found between detection of the pathogens in ejaculates and the presence of specific antibodies in serum. This study therefore confirms the limited diagnostic value of serological analysis to ascertain infection with C. trachomatis or U. urealyticum. The high frequency of detection of these pathogens among asymptomatic male partners of infertile couples emphasizes their potential role in the impairment of male fertility, and the need for sensitive and specific detection methods to prevent infection of the early embryo when using new reproductive techniques such as zona pellucida hatching or intracytoplasmic microinjection.
Hormonal deficiency in elderly males
Authors: Qian Shao‐Zhen , Cheng Xu Yuan , Zhang Jian
Published: March 2003

During the aging process, a number of morphological and neurochemical alterations have been found in the supra‐chiasmatic nuclei, which are in part responsible for the age‐dependent decrease in plasma testosterone (andropause or PADAM), DHEA (adrenopause), GH/IGF‐I (somatopause) and melatonin that develops in most men at about the age of 50 ( Perry, 1999;
Vermeulen et al., 1999
). An important principle in antiaging practice is the employment of the best of available means to prevent the preventable and delay the inevitable. Therefore, some scientists advocate multihormonal replacement therapy and the use of antioxidant drugs that may favourably influence some of the pathological conditions in aging men.
Prostate cancer in Honolulu, Hawaii: pathological and clinical characteristics
Authors: Namiki  , Carlile
Published: March 2003

We reviewed trends in prostate cancer at our institution to determine if there are changing characteristics that need to be considered in conducting comparative studies with patients from other institutions. Assessed between 1993 and 1998 were trends in PSA status, race, tumour grade, clinical stage and treatment. The incidence dropped between 1993 and 1994, but has remained stable since, except in Philipinos. Changes in clinical tumour stage and PSA positive rate were not noted; Gleason score distribution changed with marked decline of low grade tumours. This reflects the tendency pathologists had of undergrading prostatic adenocarcinoma in biopsy specimens during the early 1990s. Use of hormonal treatment increased from 21% to 57%. Patients receiving radiation therapy also increased slightly. Comparative studies between institutions would require review of the biopsy material for accurate Gleason scores. Outcome studies would need to control for the changing pattern of prostate cancer therapy.
Feasibility of surveillance of changes in human fertility and semen quality
Authors: Baker  , Garrett  , Clarke  , Stewart  , Brown  , Venn  , Mbizvo  , Farley
Published: March 2003

To show that male fertility is declining is not simple. Few men volunteer and recruitment bias may lead to over‐representation of the subfertile. Semen analysis has errors arising from counting and poorly standardized criteria, which may be overcome by automation. Time to pregnancy (TTP)–the number of menstrual cycles taken to conceive–measures fertility and allows male recruitment bias to be estimated. We review automated measurement of sperm concentration, motility and morphology and present a preliminary report on a study to assess a retrospective TTP questionnaire, recruitment bias and feasibility for large‐scale surveillance of fertility.
Identification of differentiation antigens in mouse testicular germ cells recognized by monoclonal antibody TRA 55
Authors: Ling X. , Tanaka H. , Tsuchida J. , Nishimune Y.
Published: March 2003

We have isolated a monoclonal antibody (mAb) TRA 55, which recognizes mouse testicular germ cells from mid‐pachytene spermatocytes to the early stages of haploid spermatids during differentiation. Immunohistochemical analysis produced strong positive staining of the nuclei and faint staining in the cytoplasm of germ cells. At meiotic division, when the nuclear membrane disappeared, a specific positive signal could be observed on metaphase chromosomes. When germ cells produced haploid spermatids, antigenicity became suddenly weak and soon disappeared. TRA 55 did not react with testicular somatic cells, such as Sertoli cells or Leydig cells. Western blot analysis of the whole testis showed four positive bands with molecular weights of 43, 46, 49 and 55 kDa. Three bands of 43, 49 and 55 kDa, and a single band of 46 kDa were recovered in cytoplasmic and nuclear fractions of testicular germ cells, respectively. Chronological changes in the Western blot pattern indicated that these antigens became detectable in the testis at the age of 10 days. Furthermore, all antigens were resistant to periodate treatment, suggesting that the epitope was in an amino acid rather than a sugar moiety. These antigen molecules may play important roles in the differentiation of germ cells at the later stages of meiotic prophase and meiotic division in the mouse testis.
Accurate detection of male subclinical genital tract infection via cervical culture and DNA hybridization assay of the female partner
Authors: Trum J. W. , Pannekoek Y. , Spanjaard L. , Bleker O. P. , Van Der Veen F.
Published: March 2003

The accuracy of the PACE2 DNA hybridization assay of the cervix and cervical culture in female partners for the diagnosis of male subclinical genital tract infection were assessed in a male infertility population. A total of 184 men were screened for the presence of Chlamydia trachomatis, Ureaplasma urealyticum and Mycoplasma hominis. Seventy‐one men were identified with a positive test for one or more of the above mentioned micro‐organisms. The overall prevalence of bacterial infection was 39%. Female partners of all men were tested with the PACE2 DNA hybridization assay to detect a C. trachomatis infection. Sensitivity was 100% and specificity was 100%. In 67 female partners (94%) of men who tested positive for U. urealyticum and/or M. hominis, a cervical swab culture was performed. The sensitivity of the cervical swab culture was 100%. In view of the high prevalence of U. urealyticum and M. hominis in the male genital tract and the role these sexually transmitted pathogens may play in infertility, one might question whether all couples should be screened for the presence of these pathogens. Transurethral swab culture after digital prostatic massage is disincentive to men. The cervical culture in their female partner, performed as part of the routine fertility work‐up, is a suitable alternative to detect the presence of these micro‐organisms in the male genital tract.
Impact of a deep saturation dive on semen quality
Authors: Aitken  , Buckingham  , Richardson  , Gardiner  , Irvine
Published: March 2003

The demonstration dive ‘Aurora’ has provided an opportunity to study the impact of extreme hyperbaric conditions on male fertility. This operation involved a 33‐day diving programme during which divers were exposed to a maximum pressure of 4.6 Mega Pascals (Mpa) for 7 days. At days – 4, + 27, + 34, + 82 and + 263 relative to the initiation of the dive, semen samples were analysed to determine the quality of spermatogenesis and the functional competence of the spermatozoa. A dramatic fall in semen quality was observed in association with the dive and by day + 82 the potential fertility of the men was seriously compromised as evidenced by oligoasthenoteratozoospermic semen profiles and the poor fertilizing potential of the spermatozoa. These studies indicate, for the first time, that the severe hyperbaric conditions associated with deep saturation dives have a profound effect on male reproductive function.
Low number of Y‐chromosome deletions in infertile azoospermic men at a Swedish andrology centre
Authors: Österlund Christina , Segersteen Eva , Arver Stefan , Pousette Åke
Published: March 2003

Recent studies have strongly indicated that at least three regions [azoospermia factor (AZF) a–c] on the long arm of the Y‐chromosome code for factors involved in spermatogenesis. In order to reveal the prevalence of microdeletions in these regions in a Swedish population, 192 men consecutively referred to our andrology unit due to infertility and showing oligozoospermia (n=53) or azoospermia (n=139) but no obstruction or hormonal disturbances, were investigated. For this study we used a multiplex polymerase chain reaction (PCR) method including 13 pairs of primers divided into five different primer mixes. It was found that four men, all with azoospermia, had deletions including part of the AZFb region and probably the entire AZFc region. Testis biopsies showed different morphology ranging from absence of germ cells to hypospermatogenisis. Of special interest was one patient that was first investigated 10 years ago due to primary infertility and oligozoospermia. Today he has developed azoospermia. It is concluded that the number of patients with microdeletions on the Y chromosome is rather low (less than 3% in highly selected azoospermic men) in our study compared to a number of other studies in which a 1–55% incidence have been reported. It is possible that ethnic differences, selection criteria and methodological aspects can contribute to the difference between the present and previous studies.
Penile prosthesis surgery under local penile block anaesthesia via the infrapubic space
Authors: Ghanem Hussein , Fouad Gamal
Published: March 2003

The aim of this study was to evaluate the effectiveness and patient tolerance to local penile block anaesthesia via the infrapubic space with penile prosthesis implantation. Local anaesthesia was administered using a 23‐guage 1.5‐inch needle. A 50–50 mixture of 0.5% bupivicaine (Marcaine) and 0.5% lidocaine (Xylocaine) without adrenaline was injected into the infrapubic space with additional subcutaneous penile ring infiltration at the level of the penile root. A total number of 159 patients underwent this technique, mean age 57 years (range 34–86). In 148 (93%) patients, no booster sedation was needed; eight (5%) patients needed a boost of the pre‐operative sedative during crural dilatation; three (1.8%) patients required general anaesthesia owing to insufficiently effective local anaesthesia and unexpectedly difficult dilatation. It is concluded that local anaesthesia was effective and safe to produce a pain‐free procedure in 93% of cases. However, as the need for booster sedation or general anaesthesia exists, the procedure should be performed under monitored anaesthetic care and pre‐operative evaluation should be performed as for general anaesthesia.
Constitutive production of interleukin‐1α mRNA and protein in the developing rat testis
Authors: Wahab‐Wahlgren A. , Holst M. , Ayele D. , Sultana T. , Parvinen M. , Gustafsson K. , Granholm T. , Söder O.
Published: March 2003

Interleukin‐1 (IL‐1), a multifunctional cytokine produced mainly by activated macrophages, is also produced in the intact testis. Rat testicular IL‐1 was found to be identical to IL‐1α, judged by immunoneutralization of the bioactive protein and sequence comparison of cloned rat testicular and macrophage pro‐IL‐1α cDNA. Testicular IL‐1α mRNA was first demonstrated on postnatal day 15, and the corresponding bioactive protein from day 20. IL‐1α mRNA was still low on day 20, but then increased rapidly in parallel with the bioactive protein to establish a plateau level from day 25. In adult testes, IL‐1α mRNA and immunoreactive protein were low in stage VII of the seminiferous epithelial cycle, whereas other stages showed a clearly detectable expression. In the adult testis, the concentration of IL‐1α was 75 pg/mg testicular protein (approximately 200 pM). In conclusion, production of testicular IL‐1α is developmentally and stage‐dependently regulated, probably at the transcriptional level, emphasizing an important paracrine role in testicular function.