bluuebunny/crossref_metadata_2025_split huggingface dataset:
Apoptosis‐inducing protein derived from hepatocyte selectively induces apoptosis in lymphocytes
Authors: Ikeda Masanobu , Yoshikawa Hideshi , Liu Jie , Nakajima Yasuo , Akahane Yoshihiro , Tasaka Kachio 
Published: March 2003

SummaryThe liver is where lymphocytes undergo activation‐induced cell death (AICD) at the resolution phase of an immune response, which is crucial for homeostasis of the immune system and prevention of autoimmunity. Exploring the machinery of AICD in the liver, we found that a primary culture supernatant of murine hepatocytes had an antiproliferative effect on antigen‐stimulated T clone and T lymphoma cells. Biological study showed that the antiproliferation was due to induction of apoptosis in a caspase‐dependent manner. The apoptosis‐inducing potential was sensitive to trypsin, heat (> 70°) and acid (< pH 5) treatment but could not be neutralized by anti‐tumour necrosis factor‐α, anti‐Fas ligand, or anti‐transforming growth factor‐β antibodies. Biochemical study of the isolated and purified apoptosis‐inducing component from the supernatant showed that it was a protein with a molecular mass of about 68 000–70 000. It induced apoptotic change in murine T and B cells, and to a lesser degree, in human lymphoid cells, but not in macrophages. Biochemical and biological characteristics distinguish this protein from others that have been reported to induce apoptosis of lymphocytes. The identification of an apoptosis‐inducing protein derived from murine hepatocytes, which selectively induces apoptosis in lymphocytes, suggests one possible mechanism for immune suppression in the liver.
Interleukin‐1β converting enzyme subfamily inhibitors prevent induction of CD86 molecules by butyrate through a CREB‐dependent mechanism in HL60 cells
Authors: Suzuki M. , Shinohara F. , Sato K. , Taniguchi T. , Takada H. , Rikiishi H. 
Published: March 2003

SummaryTo investigate the underlying mechanism for induction of CD86 molecules, we analysed the ability of the histone deacetylase (HDAC) inhibitor, sodium butyrate (NaB), to induce CD86 at the transcriptional level in HL60 cells. Our studies showed that the expression of CD86 on the cell surface was increased by 24 hr of NaB treatment, and the enhancement of CD86 mRNA expression was observed by real‐time polymerase chain reaction. When we measured NF‐κB binding activity, significant activity was induced upon NaB stimulation, which was suppressed by the addition of pyrrolidine dithiocarbamate. Butyrate also induced phosphorylated cAMP response element‐binding protein (CREB), which bound to cAMP‐responsive elements. Dibutyryl (db) ‐cAMP induced active CREB and increased the levels of CD86 by 24 hr. These observations indicated that NF‐κB and/or CREB are crucial for butyrate‐dependent activation of CD86 gene expression. We examined the inhibitory effects of various caspase inhibitors on the expression of CD86 in cells treated with NaB, because NaB also induced apoptosis with slow kinetics. Intriguingly, our results demonstrated that inhibitors of the interleukin‐1β converting enzyme subfamily (caspase‐1, ‐4, ‐5 and ‐13) blocked the butyrate‐induced increase in level of CD86. These inhibitors interfered with CD86 gene transcription in the presence of activated NF‐κB, whereas phosphorylated CREB was down‐regulated in the reactions where these inhibitors were added to inhibit CD86 gene expression. These results suggested that butyrate not only acetylates histones on the CD86 promoter through the suppression of HDAC activity, but that butyrate also regulates CREB‐mediated transcription, possibly through the caspase activities triggered by NaB.
Induction of gene expression of antibacterial proteins by chitin oligomers in the silkworm, Bombyx mori
Authors: Furukawa S. , Taniai K. , Yang J. , Shono T. , Yamakawa M. 
Published: March 2003

AbstractActivation of antibacterial protein genes by various chitin oligomers (from dimer to hexamer) was investigated by Northern blot analysis using cDNAs encoding cecropin B, attacin and lebocin from Bombyx mori as probes. All chitin oligomers tested were found to strongly trigger expression of cecropin B, attacin and lebocin genes. Furthermore, gene expression triggered by chitin oligomers was confirmed to occur specifically in the fat body and haemocytes. These results suggest that chitin oligomers have the same characteristics as those of lipopolysaccharide (LPS) and peptidoglycan in triggering gene expression of insect antibacterial proteins.
Mitochondrial DNA sequence divergence among greenbug (Homoptera: Aphididae) biotypes: evidence for host‐adapted races
Authors: Shufran K. A. , Burd J. D. , Anstead J. A. , Lushai G. 
Published: March 2003

AbstractThe full complement of known greenbug, Schizaphis graminum (Rondani), biotypes found in the USA were subjected to a molecular phylogenetic analysis based on a 1.2‐kb portion of the cytochrome oxidase I mitochondrial gene. In addition to these nine biotypes (B, C, E, F, G, H, I, J and K), a probable isolate of the enigmatic biotype A (NY), a ‘new biotype’ collected from Elymus canadensis (L.) (CWR), and an isolate from Germany (EUR) were included. Schizaphis rotundiventris (Signoret) was included as an outgroup. Genetic distances among S. graminum biotypes ranged from 0.08% to 6.17% difference in nucleotide substitutions. Neighbour‐joining, maximum parsimony and maximum likelihood analyses all produced dendrograms revealing three clades within S. graminum. Clade 1 contained the ‘agricultural’ biotypes commonly found on sorghum and wheat (C, E, K, I, plus J) and there were few substitutions among these biotypes. Clade 2 contained F, G and NY, and Clade 3 contained B, CWR and EUR, all of which are rarely found on crops. The rarest biotype, H, fell outside the above clades and may represent another Schizaphis species. S. graminum biotypes are a mixture of genotypes belonging to three clades and may have diverged as host‐adapted races on wild grasses.
Beta‐integrin of Anopheles gambiae: mRNA cloning and analysis of structure and expression
Authors: Mahairaki V. , Lycett G. , Blass C. , Louis C. 
Published: March 2003

AbstractWe have isolated an mRNA encoding a β integrin subunit of the malaria mosquito Anopheles gambiae. Our analysis predicts a protein that is very similar to βPS, the fruitfly orthologue. The gene is expressed during all developmental stages and it is found in all body parts, including the midgut. Finally, the expression of the gene does not seem to be modulated during blood meals, except for a substantial increase 48 h posthaematophagy, when digestion is nearly complete.
Leakage of five root canal sealers
Authors: Miletić I. , Anić I. , Pezelj‐Ribarić S. , Jukić S. 
Published: March 2003

Aim The aim of this study was to examine the apical sealing ability of five root canal sealers using a fluid transport model.Methodology A comparison of root canal sealers AH26, AH Plus, Diaket, Apexit, and Ketac‐Endo were tested on 60 single‐rooted teeth. The coronal part of each tooth was removed at the amelo‐cemento junction, and also 3 mm of the root tip. Root canals were instrumented using the ‘step‐back’ technique with Gates Glidden drills and irrigated with 2.5% NaOCl. The specimens were divided into five groups of 10 samples each and filled with test materials and gutta‐percha points by the cold lateral condensation technique. Ten teeth were used as a control group, out of which five served as negative and five as positive controls. The leakage was measured by the movement of an air bubble in a capillary glass tube connected to the experimental root section.Results The differences in leakage amongst Ketac‐Endo (0.318μL; SD 0.084), AH26 (0.319μL; SD 0.075), AH Plus (0.330L; SD 0.085) Apexit (0.360μL; SD 0.127) and Diaket (0.387μL; SD 0.140) were not statistically significant (P 0.05).Conclusions Under the conditions of this study, all five sealers produced a satisfactory seal.
A comparison of thermocouple and infrared thermographic analysis of temperature rise on the root surface during the continuous wave of condensation technique
Authors: Mc Cullagh J. J. P. , Setchell D. J. , Gulabivala K. , Hussey D. L. , Biagioni P. , Lamey P.‐J. , Bailey G. 
Published: March 2003

AbstractAimThis study was designed to use two methods of temperature measurement to analyse and quantify the in vitro root surface temperature changes during the initial stage of the continuous wave technique of obturation of 17 single‐rooted premolar teeth with standard canal preparations.MethodologyA model was designed to allow simultaneous temperature measurement with both thermocouples and an infrared thermal imaging system. Two thermocouples were placed on the root surface, one coronally and the other near the root apex. A series of thermal images were recorded by an infrared thermal imaging camera during the downpack procedure.ResultsThe mean temperature rises on the root surface, as measured by the two thermocouples, averaged 13.9 °C over the period of study, whilst the infrared thermal imaging system measured an average rise of 28.4 °C at the same sites. Temperatures at the more apical point were higher than those measured coronally. After the first wave of condensation, the second activation of the plugger in the canal prior to its removal always resulted in a secondary rise in temperature. The thermal imaging system detected areas of greater temperature change distant from the two selected thermocouple sites.ConclusionsThe continuous wave technique of obturation may result in high temperatures on the external root surface. Infrared thermography is a useful device for mapping patterns of temperature change over a large area.
An in vitro comparison of canal preparation using two automated rotary nickel–titanium instrumentation techniques
Authors: Jardine S. J. , Gulabivala K. 
Published: March 2003

AbstractAimThe aim of this study was to compare the efficacy of root canal preparation using two automated rotary nickel–titanium instrumentation techniques with a double flared balanced forces hand preparation technique, using stainless steel files in extracted human teeth.MethodologySixty root canals in extracted human teeth were matched for curvature, length and diameter and divided evenly between three groups (group 1 = double flare using Flexofiles®, group 2 = rotary nickel–titanium using McXIM® instruments and group 3 = rotary nickel–titanium using Profile® .04 TaperTM Series 29 instruments). The instruments were used according to the manufacturer’s instructions in a torque controlled motor and handpiece (groups 2 and 3) and according to a predetermined procedure in group 1. A standardized radiographic technique using mercury as a contrast medium was used to evaluate the canal shape before and after preparation in the plane of maximum curvature. The pre‐ and postoperative radiographic images were compared against each other and with a predicted ‘ideal preparation’ calculated from a projection of the final instrument dimensions. The outcome measures were changes in canal dimensions as quantified by measuring the changes in the position of the inner and outer wall at 1 mm intervals. Alteration in canal curvature could be inferred by comparison with the ideal preparation.ResultsThe degree of canal curvature did not influence the effectiveness of any of the techniques. The results showed no statistically significant differences in the outcome measures between the groups (two‐way anova). There were no significant differences in canal wall position changes at any level except the apical three, where significantly less change occurred in all groups (P = 1%). Instruments fractured in three canals, with acute curves in groups 2 and 3.ConclusionsCanal curvatures were equally and well maintained following preparation in all the groups, as long as the instrument did not fracture.
Cytotoxicity of resin‐, zinc oxide–eugenol‐, and calcium hydroxide‐based root canal sealers on human periodontal ligament cells and permanent V79 cells
Authors: Huang F.‐M. , Tai K.‐W. , Chou M.‐Y. , Chang Y.‐C. 
Published: March 2003

AbstractAim The purpose of this study was to determine the cytotoxicity of three different types of root canal sealer on human periodontal ligament (PDL) cells and a permanent hamster cell line (V79 cells).Methodology Set specimens from two resin based sealers (AH26 and AHPlus), three zinc oxide–eugenol‐based sealers (Canals, Endomethansone and N2) and one calcium hydroxide‐based sealer (Sealapex) were eluted with culture medium for 1, 2, 3 and 7 days. Cytotoxicity was judged using tetrazolium bromide reduction assay on human primary PDL cells and V79 cells derived from a Chinese hamster.Results The results showed that elutes from resin‐based, zinc oxide–eugenol‐based, and calcium hydroxide‐based sealers were cytotoxic to primary human PDL cultures and V79 cells. Calcium hydroxide‐based sealer was the least toxic sealer amongst the chemicals tested in both cultures. The cytotoxic response decreased in an order of N2 > Endomethansone > AH26 > AHplus > Canals > Sealapex.Conclusions The sensitivity of toxicity depended on the materials tested and the cell culture system used. Thus, the use of both permanent and primary cells is recommended for screening of the cytotoxic effects of root canal sealers. In addition, the results confirmed that root canal sealers constantly dissolve when exposed to an aqueous environment for extended periods, possibly causing moderate or severe cytotoxic reactions. Use of calcium hydroxide‐based material as a root canal sealer initially may result in a more favourable response to periradicular tissues.
Secular and seasonal changes in semen quality among young Danish men: a statistical analysis of semen samples from 1927 donor candidates during 1977–1995
Authors: GYLLENBORG  , SKAKKEBÆK  , NIELSEN  , KEIDING  , GIWERCMAN  
Published: March 2003

The objective of this study was to investigate whether semen quality has changed during the years 1977–1995 in a group of unselected semen donor candidates, and to determine whether semen quality is subject to seasonal variation, by analysis of time‐ and season‐related changes in semen quality using multiple regression and ANOVA. The study was based on analysis of the first semen sample delivered by 1927 semen donor candidates in Copenhagen during the period 1977–1995, with determination of semen volume, sperm concentration, total sperm count, percentage motile spermatozoa, and a semi‐quantitative sperm motility score.Multiple linear regression analysis with year, sexual abstinence and season as covariates showed a significant increase in mean sperm concentration from 53.0 × 106/mL in 1977 to 72.7 × 106/mL in 1995 (p < 0.0001) and in mean total sperm count from 166.0 × 106 to 227.6 × 106 (p < 0.0001). Mean semen volume and percentage motile spermatozoa did not change. Sperm motility deteriorated, as the spermatozoa in 74.2% of the samples were of excellent motility in 1977–1980 compared to only 41.9% in 1993–1995 (χ2=130.0, p < 0.0001). Analysis of variance showed significant variation between seasons regarding sperm concentration (p < 0.0001) and total sperm count (p < 0.0001). Highest sperm counts were found in spring, with a mean concentration (95% C.I.) of 77.6 × 106/mL (71.9–83.7), and lowest in summer, with a mean of 57.5 × 106/mL (50.1–65.4). No other semen parameter varied with season. It is concluded that sperm counts increased, whereas sperm motility decreased, in a group of Danish semen donor candidates, from 1977 to 1995. Due to the retrospective design and the anonymity of the donors, we were unable to control for variation in donor age, and we cannot exclude the possibility that some donor candidates were selected by being accepted as donors by other semen donor services in Copenhagen. With these limitations in mind, we suggest our results should be interpreted cautiously and regarded as a contribution to the ongoing dispute on whether or not there is a continuous decrease in sperm quality.The seasonal variations found in sperm concentration and total sperm count were pronounced and were not attributable to seasonal differences in the length of sexual abstinence. Additionally, the same seasonal pattern was observed in five successive year‐intervals. These findings strongly indicate that human testicular function is influenced by season, a phenomenon well known in many lower mammals.
Antiproliferative effect of thalidomide alone and combined with carmustine against C6 rat glioma
Authors: ARRIETA OSCAR , GUEVARA PATRICIA , TAMARIZ JOAQUÍN , REMBAO DANIEL , RIVERA ERIKA , SOTELO JULIO 
Published: March 2003

Summary. Thalidomide could have therapeutic applications in neoplasms and in other diseases, particularly those of autoimmune origin. The objective of this study was to investigate the effect of various doses of thalidomide on the growth of C6 glioma in rats, and to determine its effects on parameters of cell proliferation and angiogenesis. Additionally, we investigated a potential enhancement of the antitumoral action of thalidomide when combined with a low dose of the antineoplastic carmustine. C6 glioma cells were implanted subcutaneously in Wistar rats. A highly malignant glioma developed in 80% of animals. When the tumour reached 2.0 cm diameter thalidomide was administered at doses of 100, 200 or 400 mg/kg/day. When given at a dose of 400 mg/kg/day thalidomide significantly reduced the tumour volume, the mitotic index and cell proliferation but not the vascular density. The combination of thalidomide plus carmustine increased the inhibitory effect on tumoral growth. Our results indicate that thalidomide is effective against malignant glioma; apparently by an antiproliferative effect, rather than by inhibition of angiogenesis; when combined with carmustine it could increase the response of glioma to antineoplastic treatment.
Microleakage of composite resins in cavities of upper primary molars
Authors: Nozaka K. , Suruga Y. , Amari E. 
Published: March 2003

Objective. To improve the quality of resin restorations, studies are necessary not only of the physical properties of materials but also of the cavity geometry. We have evaluated marginal microleakage for two types of photo‐curing composite resin applied to cavities with different marginal structures. Sample and methods. The test materials were 91 extracted upper primary molars. The two composite resins used in this experiment were Liner Bond II (LBII) and Photo Clearfil A (PCA). A class 1 cavity was created in each tooth; the cavity configuration was a round bevel, a straight bevel and a butt joint. The tooth was then restored with each composite resin. Each tooth was exposed to thermal cycles, followed by immersion in 0·2% basic fuchsin solution. Three sections, through the mesial, central and distal areas of each tooth were taken. The penetration of the dye was examined with a stereoscopic microscope. The sites of observation for examination of microleakage were awarded scores of between 0 and 7. Results. LBII–among the three marginal forms, absence of leakage was observed most frequently in the straight bevel group followed by the round bevel and the butt joint groups, in the mesial and distal sections. In the central section, the straight bevel did not show any scores of 0, 6 or 7.PCA–an absence of leakage in the mesial section occurred most frequently for the round bevel group. However, the absence of leakage in the central and distal sections was most frequent for the straight bevel group. Microleakage of the central section (with scores from 1 to 7) was frequently lower than that for the mesial and distal sections. Scores of 5 and above in the central section were observed only in the butt joint group.The frequency and mean score of leakage were clearly higher in LBII than in PCA, with one significant exception. For both composite resins, the butt joint group showed higher‐mean scores of leakage than did either the round or straight bevel group, but for PCA, the mean score of the central section was lower than the other two sections in all groups. Conclusion. Our study shows that bevelling does reduce marginal leakage. This leakage was more frequently observed with the use of LBII than with PCA. However, the amount of tooth ground away was greater for the bevel‐treated cavity. In considering these features, special care is necessary in selecting the bur for treating a bevelled cavity.
Enamel hypomineralization of permanent first molars: a morphological study and survey of possible aetiological factors
Authors: Jälevik B. , Norén J.G. 
Published: March 2003

Objectives. The aim of this study was to investigate the morphological appearance of severe hypomineralized enamel of permanent first molars by means of polarized light microscopy, and to estimate the possible time, severity and longevity of the insult. Furthermore, the aim was to survey some commonly implicated aetiological factors in order to gain knowledge about possible pathogenesis of the enamel disturbances which could be compared with future epidemiological studies. Sample and methods. Seventy‐three teeth, which had been extracted due to severe hypomineralizations of the enamel, were collected and serially cut longitudinally in a bucco‐lingual direction. The sections were examined in polarized light, dry and embedded in water. The children were also examined with respect to the demarcated opacities of other permanent teeth than those that were extracted. The parents were asked about their health during the mother’s pregnancy, the time of gestation, birth weight and any complications. They were also asked about the child’s health during the first 2 years of its life, the length of time of breast‐feeding and also about fluoride supplements. Results. The hypomineralized areas extended cervically from the cusps, comprising about half of the buccal and lingual sides. The cervical borders to normal enamel were well defined and mainly followed the lines of Hunter‐Schreger. The hypomineralized zones were covered by thin well‐mineralized enamel. The majority of the children had demarcated opacities of all their first molars and also of some permanent incisors. No obvious correlation to the anamnestic data could be found. Conclusions. The hypomineralized enamel in the investigated teeth demonstrated areas of porosity of varying degrees. The yellow/brown defects were more porous than the white‐cream and extended through the whole enamel layer, while the white‐cream opacities were situated in the inner parts of the enamel. There had probably been an interacting disturbance of short duration of systemic origin of the activity of the ameloblast during the first 2 years of the child’s life, resulting in chronological dispersed hypomineralized demarcated opacities in the developing teeth.