bluuebunny/crossref_metadata_2025_split huggingface dataset:
Dye penetration in dry and water‐filled gaps along root fillings
Authors: Kontakiotis E. G. , Georgopoulou M. K. , Morfis A. S. 
Published: March 2003

AbstractAimThe aim of this study was to investigate the influence of hydration in voids along root fillings on methylene blue penetration.MethodologyA total of 80 human root canals were prepared using a step‐back technique and filled with a zinc oxide based sealer and gutta‐percha. Leakage along the fillings was measured by a transport fluid model and classified into three categories: gross leakage (GL), slight leakage (SL) and no leakage (NL). Specimens with NL and SL were immersed into methylene blue (MB) 2% for 24 h (group I). Specimens with GL which had wide gaps filled with water were randomly divided into two groups (II, III). Transport air was applied to remove water from gaps only in specimens of group III. All tested specimens from groups II and III were also immersed into MB 2% for 24 h. Each specimen was then split longitudinally and linear measurements of dye penetration were recorded.ResultsGroup III (with dry gaps) showed significantly more dye penetration than group II. No significant difference was found between group I and group II.ConclusionsMethylene blue penetrates along root fillings more easily in dry gaps than in water‐filled gaps.
A scanning electron microscopic study of debris and smear layer remaining following use of GT rotary instruments
Authors: Gambarini G. , Laszkiewicz J. 
Published: March 2003

AbstractAim The aim of the present study was to assess debris and smear layer remaining following canal preparation with GT rotary instruments.Methodology Sixteen freshly extracted single‐rooted premolar teeth were instrumented with GT™ rotary instruments using a crown‐down preparation technique. All specimens were flushed with 2 mL of 5% NaOCl between each rotary instrument. At the end of instrumentation the following final irrigation sequence was repeated two times: 2 mL of EDTA + Cetrimide for 1 min (Largal Ultra, Septodont, France) and 2 mL of 5% NaOCl for 5 min. A final flush with saline solution was made to halt any chemical activity. Two other uninstrumented teeth that were not irrigated served as controls. All teeth were split longitudinally and prepared for SEM evaluation. The presence of debris and smear layer was evaluated from photomicrographs at ×200 and ×1000 magnification taken in the apical, middle and coronal thirds of the canals. Blind evaluation was performed by two trained observers and scores were compiled separately. A five category scoring system for debris and smear layer was used. Values obtained were tabulated and statistical analysis was carried out using a parametric chi‐squared test.Results Statistical analysis showed that there was no significant difference between the three regions of the root canals (P > 0.05) for debris. Comparison of the removal of the smear layer between the three regions showed that there was a statistically significant difference between all parts, especially between the coronal and apical thirds (P < 0.001). Overall, the coronal sections were cleaner than the middle and apical sections. The uninstrumented canals showed walls completely covered with tissue, confirming that specimen preparation alone did not remove tissue.Conclusions Under the conditions of the present study GT™ rotary instruments removed debris effectively, but left root canal walls covered with smear layer, particularly in the apical third.
In vitro comparison of different types of sodium perborate used for intracoronal bleaching of discoloured teeth
Authors: Arı H. , Üngör M. 
Published: March 2003

AbstractAim To compare the bleaching efficacy of three different types of sodium perborate (SP) commonly used for intracoronal bleaching of discoloured non‐vital teeth.Methodology Sixty‐five extracted human maxillary central incisors with intact crowns were used. Following obturation with gutta‐percha and a root canal sealer using a lateral condensation technique, the coronal aspects of the root canal fillings were covered with a 1‐mm thick protective base placed to a level 1 mm apical to the labial cemento–enamel junction (CEJ). The teeth were than stained artificially with fresh blood over a period of 18 days. One or other of the bleaching materials (group 1: SP monohydrate + water, group 2: SP trihydrate + water, group 3: SP tetrahydrate + water, group 4: SP monohydrate + hydrogen peroxide (HP), group 5: SP trihydrate + HP, group 6: SP tetrahydrate + HP) were placed in the pulp chamber of the discoloured teeth and sealed with Cavit for 21 days. They were replaced with fresh preparations after 3, 7 and 14 days. The shades of the tooth crowns were evaluated at baseline and at 7, 14 and 21 days. Comparison of tooth shades was completed at each interval and analysed statistically using the chi‐squared test.Results There was no statistically significant difference between the groups at 7, 14, 21 days. Period of bleaching significantly affected the outcome (P < 0.01). No colour changes were noted in the control teeth.Conclusion The data obtained from this study demonstrate that sodium perborate can be used mixed with water rather than with hydrogen peroxide for bleaching discoloured teeth.
The role of Na,K‐ATPase in human sperm motility
Authors: Koçak‐toker N. , Aktan G. , Aykaç‐toker G. 
Published: March 2003

A fourth Na,K‐ATPase α isoform, which was found to be abundant in testes, was proved to be a catalytical subunit of the enzyme. Recently, it has been shown that the α 4 isoform along with α 1 is expressed in the midpiece of the flagellum of mature rat sperm and the inhibition of α 4 with ouabain led to sperm immotility. In this study, sperm from 135 males with normal semen profile and 50 males with oligoasthenospermia were treated with 10–5 and 10–2 M ouabain solutions to inhibit α 4, and α 4 plus α 1 isoforms, respectively. In males with normal semen profile, sperm motility has been demonstrated to decrease with time to almost the same level with both ouabain solutions. In oligoasthenospermic males motility was also found almost completely lost. These observations showed us that the α 4 isoform may be held responsible for human sperm motility.When sperm plasma membrane Na,K‐ATPase activity was assayed for both normal and oligoasthenospermic males, a significant decrease in enzyme activity of males with oligoasthenospermia was observed (p < 0.05). In our recent study, sperm motility was found decreased by treatment with peroxynitrite (ONOO–). To investigate the effect of ONOO– on sperm Na,K‐ATPase activity, sperm plasma membranes were treated with 100 μM ONOO– and plasma membrane Na,K‐ATPase activity was observed to be significantly decreased (p < 0.05). Although total sulfhydryl (SH) content of sperm plasma membrane was also found significantly lower, no correlation was found between Na,K‐ATPase activity and SH content.
Modulation of androgen receptor protein by culture conditions of human skin fibroblasts
Authors: Palma Marcela M. , Fernandez Mireya , Vivanco XIMENA , Pino Ana M. 
Published: March 2003

SummaryCultures of skin fibroblasts show variation of androgen binding with culture conditions; binding variations are usually avoided by using confluent cultures. In this work, we analysed the effect of cell density and mitogenic agents on the level of androgen receptor (AR) of cultured human skin fibroblasts. Results demonstrated that in cultures of human skin fibroblasts, cellular binding of dihydrotestosterone was higher in cells grown at low than at high cell density. The reduction in binding resulted from a decrease in the number of high affinity receptors and not from a change in receptor affinity. Immunocytochemistry for AR showed greater staining intensity in cells grown at low than at high cell density. Additionally, immunoblot analysis demonstrated more AR protein in low cell density cultures. On the other hand, it was observed that cells grown at low cell density showed diminished androgen binding capacity after 24 h of treatment with insulin‐like growth factor (IGF‐l), basic fibroblast growth factor (bFGF), epidermal growth factor (EGF), or granulocyte‐colony stimulating factor (G‐CSF); this effect of growth factors was not observed in cells grown at high cell density.  In conclusion, we found that cell density of cultures and mitogenic agents can regulate AR binding activity in human fibroblasts. While we do not yet know how changes in cell density affect the amount of AR, we conclude that the mechanism could be mediated by activation of the tyrosine kinase pathway, as the effect was reproduced by mitogens.
Causes of gynaecomastia in young adult males and factors associated with idiopathic gynaecomastia
Authors: Ersöz Halil önder , önde Mehmet Emin , Terekeci Hakan , Kurtoglu Soner , Tor Hayati 
Published: March 2003

SummaryGynaecomastia is a common clinical condition. Persistent pubertal or late onset idiopathic gynaecomastia is the leading cause of gynaecomastia in different series. The aim of this study was the assessment of the prevalence and characteristics of different causes of gynaecomastia in young adult males, and evaluation of the factors associated with idiopathic gynaecomastia. Fifty‐three male patients (mean age 22.04 ± 2.22, range 19–29), who had been admitted to our outpatient clinics with gynaecomastia as the main presenting symptom were enrolled in the study. Patients were evaluated with breast palpation, breast ultrasonography, anthropometric measurements and sex steroid levels. Secondary causes of gynaecomastia were ruled out. Thirty age‐matched healthy individuals were also studied as healthy control group. Idiopathic gynaecomastia was diagnosed in 31 of 53 patients (58%), with 17 (32%) persistent pubertal and 14 (24%) late onset course. Other causes of gynaecomastia were hypogonadism in 13 cases (25%), hyperprolactinaemia in five (9%), chronic liver disease in two (4%), and drug induced (prolonged use of H2 antagonists) in two (4%). Patients with idiopathic gynaecomastia, either pubertal or late onset, were compared with the healthy control group in order to find out associated factors. Anthropometric measurements revealed a significant increase in body weight and body mass index (BMI) in the patient group compared with healthy controls (72.4 ± 13.3 vs. 63.6 ± 7.9 kg, p = 0.0086 and 25.2 ± 4.0 vs. 21.5 ± 2.7 kg/m2, p = 0.0001). Total skin fold thickness (SFT) of four different regions were also higher in the patient group (50.9 ± 22.1 vs. 32.6 ± 10.2 mm, p = 0.0006) indicating a higher body fat percentage. Total serum testosterone (4.76 ± 1.31 vs. 5.70 ± 1.06 μg/mL, p = 0.0038) and luteinizing hormone (LH) (4.80 ± 1.92 vs. 7.32 ± 1.90 mIU/mL, p < 0.0001) levels were significantly lower in the patient group while oestradiol levels were similar. There was a significant correlation between total testosterone and LH levels (r = 0.27, p = 0.0445). Total testosterone and LH levels were negatively correlated with BMI and total SFT. As a result most common form of gynaecomastia is idiopathic gynaecomastia either as persistent pubertal or late onset forms in young adult males. Idiopathic gynaecomastia is closely correlated with generalized obesity, reduced LH and testosterone levels which may be the result of increased conversion of testosterone to oestradiol in increased adipose tissue mass.
Heterogeneity in the granulomatous response to mycobacterial infection in patients with defined genetic mutations in the interleukin 12‐dependent interferon‐gamma production pathway
Authors: LAMMAS D. A. , DE HEER E. , EDGAR J. D. , NOVELLI V. , BEN‐SMITH A. , BARETTO R. , DRYSDALE P. , BINCH J. , MACLENNAN C. , KUMARARATNE D. S. , PANCHALINGAM S. , OTTENHOFF T. H. M. , CASANOVA J.‐L. , EMILE J.F. 
Published: March 2003

SummaryPatients with genetic lesions in the Type‐1 cytokine/cytokine receptor pathway exhibit a selective susceptibility to severe infections with poorly pathogenic mycobacteria and non‐typhi salmonella spp. These experiments of nature demonstrate that IL‐12‐dependent IFNγ production is critical for granuloma formation and therefore host immunity against such pathogens. The essential role of granuloma formation for protective immunity to these organisms is emphasized by the differing granuloma forming capabilities and resultant clinical sequelae observed in these patients which seems to reflect their ability to produce or respond to IFNγ (Fig. 9). At one pole of this spectrum, represented by the complete IFNγR1/2 deficient patients, there is a complete absence of mature granuloma formation, whereas with the less severe mutations (i.e. partial IFNγR1/2, complete IL‐12p40 and complete IL‐12Rβ1 deficiency), granuloma formation is very heterogenous with wide variations in composition being observed. This suggests that in the latter individuals, who produce partial but suboptimal IFNγ responses, other influences, including pathogen virulence and host genotype may also affect the type and scale of the cellular response elicited. Spectrum of genetic susceptibility to intracellular bacteria. At one pole of this spectrum complete IFNγR deficiencies are found; at the other pole are healthy resistant individuals. Partial IFNγR1 deficiencies, and complete IL‐12Rβ1 and IL‐12p40 deficiencies can be positioned in between, albeit closer to the former end of the spectrum, with clinical outcome also depending on pathogen virulence and host compensatory immune mechanism(s). Abbreviations: IFNγR – interferon gamma receptor, IL‐12Rβ1 – interleukin 12 receptor‐1 (modified from Ottenhoff et al. (1998)).image
Time course of bleomycin‐induced lung fibrosis
Authors: Izbicki G. , Segel M.J. , Christensen T.G. , Conner M.W. , Breuer R. 
Published: March 2003

Summary.Intratracheal instillation (IT) of bleomycin is a widely used experimental model for lung fibrosis. In this study we describe the time‐course of bleomycin‐induced lung fibrosis in mice using computer‐assisted morphometry. C57Bl/6J mice were treated with a single IT dose of bleomycin or control saline. Animals were killed 3, 6, 14 and 21 days post‐IT. Lung injury was evaluated by analysis of bronchoalveolar lavage (BAL) fluid, hydroxyproline concentration in the lung, routine light microscopic examination resulting in a semiquantitative morphological index (SMI) of lung injury, and quantitative morphological measurements (fibrosis fraction and alveolar wall area fraction) aided by optimas image analysis software. Changes in BAL fluid attributed to bleomycin treatment include increased total cell count (days 14 and 21), and increased percentage of neutrophils (days 3 and 6) followed by a sustained increase in lymphocytes (days 6, 14 and 21). Hydroxyproline levels increased in bleomycin‐treated mice on days 14 and 21. Median SMI grades were significantly elevated on days 3, 14 and 21. Computer‐assisted morphometry demonstrated a 3‐fold increase in fibrosis fraction and a 1.3‐fold increase in wall area fraction in bleomycin‐treated mice on day 14, with no further increase on day 21. These data also demonstrate that the most suitable time point for assessing lung fibrosis in this model is 14 days after IT instillation of bleomycin, based on the observation that at 14 days the animals developed extensive fibrosis, but had less variability in the fibrotic response and lower mortality than later at 21 days. Computer‐assisted morphometry provides objective and quantitative measurements that are a useful tool for the evaluation of bleomycin‐induced lung injury.
Chemical tainting of foods
Authors: Mottram Donald S. 
Published: March 2003

Taints and off‐flavours in food are a major cause of consumer rejection of the food product, and consequently the occurrence of such flavour defects is of great concern also to the manufacturer. Unacceptable flavours in foods may develop within the food through chemical or microbial action on food components, or they may be inadvertently introduced into the food during processing or storage, by absorption of chemicals from airborne, waterborne or packaging‐related sources. The chemicals responsible for taints and off‐flavours are usually volatile organic compounds, which are frequently found at concentrations of less than 1 μg kg−1, and cause flavour problems because of their low odour‐threshold values. This paper discusses the possible origins of off‐flavours and taints in foods, and describes some incidents in which food taints have been caused by chemical contamination from the environment.
Novel food products from genetically modified crop plants: methods and future prospects
Authors: Dunwell Jim M. 
Published: March 2003

SummaryUsing a variety of in vitro techniques, it is now possible to isolate a selected gene sequence from any source and introduce it into any major crop plant. Millions of hectares of such genetically modified (GM) or transgenic plants are already being grown commercially, mostly in North America. To date, the most widely grown GM crops (soybean and maize) are those with modified agronomic traits (herbicide or insect tolerance); the products from these commodity crops are now included in a wide range of processed foods. This review describes the methods used to generate these GM crops and then discusses the range of modified food products that can be generated using this new technology. Such products include those with altered protein, starch or oil quality, as well as examples of improved micronutrient or vitamin content. Much of this work, particularly that aiming to develop food with specific health benefits, is still at the experimental stage, but there is no doubt that many GM foodstuffs, with an increasing variety of qualitative changes, will reach the market in the coming years. The rate at which such products are developed commercially depends to a large extent on the public reaction to a technology still poorly understood by most consumers.
The optimization of a laboratory processing procedure for southern‐style Chinese steamed bread
Authors: Huang  , Quail  , Moss  
Published: March 2003

A response surface methodology (RSM) design was used to optimize the laboratory processing procedure for southern‐style Chinese steamed bread (SSCSB). A screening test was applied to weak, medium and strong flours to establish critical variables. Consumer preference testing on the eating quality of southern‐style steamed bread (SSSB) established a scoring system for quality assessment of this product. For further RSM optimization testing, only the strong and medium flours were used. The following settings were established as optimal laboratory processing procedures for this style of steamed bread: farinograph mixer (300‐g bowl; speed 60 rpm); compressed yeast (1.5%); water addition [80% of farinograph water absorption (FWA)]; mixing time (50% of farinograph dough development time (FDDT); fermentation time (150 min); remixing time (180% FDDT); fermentation temperature (32°C); relative humidity (RH; 85%); sheeting time (20 passes); proving time (35 min); steaming rate (155 g of steam m−3 min−1); and steam time (20 min). The adequacy of the predictive models generated using the RSM procedure and reproducibility of the method for this style steamed bread were verified.
Effect of barrel temperature and screw speed on rapid viscoanalyser pasting behaviour of rice extrudate
Authors: Guha Manisha , Ali Syed Zakiuddin , Bhattacharya Suvendu 
Published: March 2003

The effect of extrusion barrel temperature (80–120 °C) and screw speed (200–400 rpm) on the pasting and gelatinization properties of extruded rice products were studied. A twin‐screw extruder was used without using a die. A rapid viscoanalyser (RVA) was used for the pasting study; the parameters determined were the initial viscosity (IV), peak viscosity (PV), hot‐paste viscosity (HPV) and cold‐paste viscosity (CPV). The PV, HPV and CPV generally decreased with increasing barrel temperature and screw speed. The IV was high, 30–43 rapid viscoanalyser units (RVU), for extrudates compared with raw rice, 3–4 RVU. The extent of gelatinization (GE) of the extruded rice samples ranged between 93.8% and 99.0%, and an increase in screw speed enhanced the GE values. Regression equations (r > 0.991, P < 0.01) that relate pasting and gelatinization behaviour to temperature and screw speeds are reported.
Characterization of rheological properties of systems containing sugar substitutes and carrageenan
Authors: Ozdemir Murat , Sadikoglu Hasan 
Published: March 2003

The effects of addition of κ‐carrageenan to solutions containing 40% (w/w) sugar substitute on the rheological properties of these systems were investigated at 25 °C using a rotational viscometer at rotational speeds of 6, 12, 30, and 60 rev min−1. The flow behaviour of the solutions was adequately described by the power law model with or without yield stress. The consistency index (K) and the flow behaviour index (n) were determined from shear stress vs. shear rate data. The flow parameters of the solutions depended on the carrageenan concentration. The apparent viscosities of the systems decreased with increasing shear rate, indicating pseudoplastic behaviour. The final carrageenan concentration was found to be an effective factor controlling the degree of sliminess of the model food systems studied.
Effect of dry heat on the in vitro digestibility and trypsin inhibitor activity of chickpea flour
Authors: Márquez  , Fernández  , Alonso  
Published: March 2003

The effect of a dry heat treatment on trypsin inhibitors, protein quality and molecular weight of products obtained from enzymatic hydrolysis of chickpea flours was analysed in order to use chickpeas as food protein hydrolysates. Chickpea flour obtained from dehusked seeds was processed under different conditions, either by heating or enzymatic treatment. Heat treatment at 140 °C for varying times (1–24 h) inactivated trypsin inhibitors and facilitated enzymatic treatment but showed an unacceptable loss in the nutritional quality of the protein for heating times longer than 6 h. Enzymatic treatment with a commercial protease, Alcalase 0.6L, at pH 8 and 50 °C, increased the protein nutritional value of the chickpea by breaking the protein chains into shorter peptide chains more suitable to human nutrition.