bluuebunny/crossref_metadata_2025_split huggingface dataset:
Designing multimedia instruction in dentistry: need for sequencing model
Authors: Aly M. , Willems G. , Carels C. , Elen J. 
Published: November 2004

When designing any piece of instruction, multimedia or other, the designer must answer two important issues: (i) how the instructional events should be sequenced over time (sequencing); (ii) how the interrelationships among these ideas should be taught to the students (synthesis). Two fundamental levels of instructional design strategies have been identified to provide sequence and synthesis: ‘macro’ and ‘micro’ strategies. Instructional designers use macro strategies to structure a number of different content ideas. Macro strategies are concerned with the organisation of memory. Many of the prescriptions about sequencing are at the macro level. Some of the well‐known sequencing strategies are: spiral curriculum; progressive differentiation; hierarchical sequencing; shortest path sequencing and elaboration sequencing.When using the multimedia environment as a learning tool, are these four basic macro strategies effective in providing sequence and synthesis of theoretical as well as clinical knowledge for dental students? Or is there a need to create a new clinical macro‐sequencing model for instructional multimedia programs in dentistry? We concluded that further research is needed on the methods, strategies and models that induce a cognitive process when adopting a computer‐assisted learning approach. A possible approach will be discussed.
Reduced hepatic glycogen stores in patients with liver cirrhosis
Authors: Krähenbühl Lukas , Lang Corinne , Lüdes Saskia , Seiler Christian , Schäfer Markus , Zimmermann Arthur , Krähenbühl Stephan 
Published: November 2004

Abstract: Background: Patients with alcoholic liver cirrhosis have reduced hepatic glycogen stores but the mechanisms leading to this finding are not clear.Methods: We therefore determined the hepatic glycogen content in patients with alcoholic (n = 9) or biliary cirrhosis (n = 8), and in control patients undergoing liver surgery (n = 14). All patients were in the postabsorptive state. In addition, we performed a morphometric analysis of the livers, and measured activities and mRNA expression of several enzymes involved in glycogen metabolism. Cirrhotic and control patients were similar regarding age and body weight.Results: Cirrhotic patients had a reduced glycogen content per gram liver wet weight (17 ± 11 versus 45 ± 17 mg/g, P < 0.05), per milliliter hepatocytes (28 ± 16 versus 52 ± 21 mg/ml, P < 0.05) and per liver (28 ± 17 versus 64 ± 22 g, P < 0.05), the reduction being observed in both patients with alcoholic or biliary cirrhosis. Liver histology confirmed these findings and revealed that the decrease in liver glycogen in cirrhotic patients was not homogenous across cirrhotic lobules. Activities of glycogen synthase and phosphorylase (total activity and active form) were not different between cirrhotic and control patients, whereas hepatic mRNA expression was decreased in cirrhotics by approximately 50%. The activity of glucokinase was decreased in cirrhotic as compared in control patients (0.06 ± 0.30 versus 0.42 ± 0.21 U/ml hepatocytes, P < 0.05), the reduction being observed in both patients with alcoholic or biliary cirrhosis.Conclusions: We conclude that patients with alcoholic or biliary cirrhosis have decreased hepatic glycogen stores per volume of hepatocytes and per liver. Decreased activity of glucokinase may represent an important mechanism leading to this finding.
Accumulating CD57 + CD3 +  natural killer T cells are related to intrahepatic bile duct lesions in primary biliary cirrhosis
Authors: Harada Kenichi , Isse Kumiko , Tsuneyama Koichi , Ohta Hajime , Nakanuma Yasuni 
Published: November 2004

Abstract: Background: Some populations of extrathymic T cells including natural killer T (NKT) cells are involved in autoimmune diseases. In particular, a deficiency of NKT cells has been implicated in human systemic sclerosis. Primary biliary cirrhosis (PBC) is an autoimmune liver disease characterized by the selective destruction of intrahepatic small bile ducts and the formation of granulomas. It is generally believed that cellular immune mechanisms, particularly T cells, cause the bile duct damage in PBC.Methods: In this study, to investigate the unique population of extrathymic T cells in PBC, we examined the T cell receptor (TCR) Vα24‐JαQ gene and CD57 + CD3 +  cells corresponding to the major genotype and one of the phenotypes of NKT cells, respectively.Results: By reverse transcription‐polymerase chain reaction (RT‐PCR), amplicons of the Vα24‐JαQ gene fragment in liver tissues of PBC were found to be similar to those of control diseased livers, demonstrating that there was no distinct deficiency of Vα24‐JαQ +  NKT cells in PBC. Immunohistochemistry for CD57 and CD3 revealed the CD57 + CD3 +  cells to be distributed in portal tracts and hepatic parenchyma in all cases studied, but the numbers of these cells were increased within portal tracts in PBC, in particular around injured interlobular bile ducts, compared to other diseased and normal livers.Conclusion: This indicates that an immune disturbance induced by a selective reduction of Vα24‐JαQ +  NKT cells is unlikely to occur in PBC. Inversely, it can be postulated that auto aggressive CD57 + CD3 +  NKT cells are recruited to regulate the altered immunity of the periductal microenvironment in PBC.
Gastrin reverses established cholangiocyte proliferation and enhanced secretin‐stimulated ductal secretion of BDL rats by activation of apoptosis through increased expression of Ca2+‐dependent PKC isoforms
Authors: Glaser Shannon , Alvaro Domenico , Ueno Yoshiyuki , Francis Heather , Marzioni Marco , Phinizy Jo Lynne , Baumann Brandy , Mancino Maria Grazia , Venter Julie , LeSage Gene , Alpini Gianfranco 
Published: November 2004

Abstract: We posed these questions: (i) Does administration of gastrin to 1‐week bile duct ligation (BDL) rats inhibits established cholangiocyte proliferation and ductal secretion? (ii) Is gastrin inhibition of cholangiocyte proliferation and secretion of BDL rats associated with enhanced apoptosis? (iii) Are gastrin's effects on cholangiocyte function associated with increased expression of protein kinase C (PKC) isoforms; and (iv) Is gastrin stimulation of cholangiocyte apoptosis regulated by the Ca2+‐dependent PKC pathway?Methods: Seven days after BDL, rats were treated with gastrin by minipumps for 14 days. Cholangiocyte proliferation was assessed by measurement of the number of PCNA and CK‐19 positive cholangiocytes in sections, and PCNA expression in cholangiocytes. Ductal secretion was determined by measurement of secretin‐induced cAMP levels and choleresis. Apoptosis was evaluated by TUNEL analysis in sections and annexin‐V staining in cholangiocytes. The expression of PKC isoforms was determined by immunoblots.Results: Gastrin inhibits established cholangiocyte proliferation and enhanced secretin‐stimulated ductal secretion of BDL rats. Gastrin's effects on cholangiocyte function were associated with enhanced apoptosis and increased expression of PKC alpha, and beta I and II. Gastrin increases in cholangiocyte apoptosis were blocked by BAPTA/AM and H7.Summary/conclusion: Gastrin inhibits cholangiocyte proliferation and secretin‐induced ductal secretion in BDL rats by increasing apoptosis through a PKC‐mediated mechanism.
Necrotic cell death induced by δ‐aminolevulinic acid in mouse astrocytes. Protective role of melatonin and other antioxidants
Authors: Juknat Adela Ana , Kotler Mónica Lidia , Quaglino Ana , Carrillo Natalia Marco , Hevor Tobias 
Published: November 2004

Abstract: Accumulation of δ‐aminolevulinic acid (ALA), as it occurs in acute intermittent porphyria (AIP), is the origin of an endogenous source of reactive oxygen species (ROS), which can exert oxidative damage to cell structures. In the present work we examined the ability of different antioxidants to revert ALA‐promoted damage, by incubating mouse astrocytes with 1.0 mm ALA for different times (1–4 hr) in the presence of melatonin (2.5 mm), superoxide dismutase (25 units/mL), catalase (200 units/mL) or glutathione (0.5 mm). The defined relative index [(malondialdehyde levels/accumulated ALA) × 100], decreases with incubation time, reaching values of 76% for melatonin and showing that the different antioxidants tested can protect astrocytes against ALA‐promoted lipid peroxidation. Concerning porphyrin biosynthesis, no effect was observed with catalase and superoxide dismutase whereas increases of 57 and 87% were obtained with glutathione and melatonin, respectively, indicating that these antioxidants may prevent the oxidation of porphobilinogen deaminase, reactivating so that the AIP genetically reduced enzyme. Here we showed that ALA induces cell death displaying a pattern of necrosis. This pattern was revealed by loss of cell membrane integrity, marked nuclear swelling and double labeling with annexin V and propidium iodide. In addition, no caspase 3‐like activity was detected. These findings provide the first experimental evidence of the involvement of ALA‐promoted ROS in the damage of proteins related to porphyrin biosynthesis and the induction of necrotic cell death in astrocytes. Interestingly, melatonin decreases the number of enlarged nuclei and shows a protective effect on cellular morphology.
Influence of cigarette filters on the risk of developing oral leukoplakia in a Kenyan population
Authors: Macigo FG , Mwaniki DL , Guthua SW , Njeru1 EK 
Published: November 2004

OBJECTIVE: To determine the influence of cigarette filters and the effect of smoking Kiraiku (home processed, hand rolled tobacco) on the risk of developing oral leukoplakia among cigarette smokers.DESIGN: Case control using population‐based study groups in a Kenyan rural community.MATERIALS AND METHODS: 85 cases and 141 controls identified in a cross‐section house‐to‐house screening of subjects aged 15 years and over and matched for sex, age (±3 years) and cluster origin were compared for their use of filter and non‐filter cigarettes as well as their history of smoking Kiraiku.RESULTS: The relative risk (RR) of oral leukoplakia was 9.1 (95% confidence intervals (CI) = 4.1–20.2) in smokers of filter cigarettes and 9.8 (95% CI = 2.3–47.0) in smokers of non‐filter cigarettes. The RR in the latter compared to the former was 1.1 and was not statistically significant. Regarding the influence of smoking Kiraiku, the RR of this lesion was 29.3 in smokers of both Kiraiku and filter cigarettes and 17.3 in smokers of both Kiraiku and non‐filter cigarettes.CONCLUSIONS: There was no statistically significant difference between the influence of filter and non‐filter cigarettes on the risk of developing oral leukoplakia. The effect of Kiraiku on the risk of this lesion was stronger in filter than in non‐filter cigarettes. However, the confounding effect of tobacco dose response parameters could not be ruled out.
Practical recommendations for the use of acupuncture in the treatment of temporomandibular disorders based on the outcome of published controlled studies
Authors: Rosted P 
Published: November 2004

OBJECTIVE: The objective is to analyse the treatment procedures used in the individual studies to identify any similarities of therapeutic approaches and subsequently present recommendations for a standard acupuncture procedure for the treatment of temporomandibular disorders (TMD).MATERIALS: Literature searches performed by the Royal Society of Medicine and the University Library, Copenhagen were able to identify 74 publications regarding the use of acupuncture in dentistry. Among them 14 papers concerned the use of acupuncture in the treatment of TMD. To ensure reasonable methodological soundness of the involved studies, only randomised and blinded studies were included, which reduced the number of papers to six. Among these six papers three concerns the same study and were counted as one. One paper was a follow‐up of a previous study and for this purpose counted as one.METHODS: All publications were analysed for the following information: acupuncture points used, type of stimulation, number of treatments, duration of the individual treatment and the interval between the individual treatments.MAIN OUTCOME: Acupuncture has in three out of three randomised controlled trials (RCT) proved effective for the treatment of TMD. The following local acupuncture points are recommended for the treatment of TMD: ST‐6, ST‐7, SI‐18, GV‐20, GB‐20, BL‐10. As a distant point LI‐4 is recommended. After inserting the needles they should be manipulated manually to achieve the De‐qui sensation and left in situ for 30 min. Treatment should be given weekly and a total number of six treatments is recommended.
Cherubism—clinical picture and treatment
Authors: Kozakiewicz M , Perczynska‐Partyka W , Kobos J 
Published: November 2004

Cherubism is a rare, painless, disfigurating disease primarily affecting bones of the jaws.OBJECTIVE: To report on five patients with cherubism. The symptoms of the disease, methods of management and possible mode of inheritance are discussed and literature is reviewed.PATIENTS: The study involves five cherubs, members of one family. The diagnoses were based on history, physical examination, laboratory tests, X‐ray parameters, and clinical follow‐up. One member of the family had surgical intervention. The remaining cases were left for observation.RESULTS: Good aesthetic and long lasting effect was reached in the operated patient.CONCLUSIONS: Treatment is unnecessary unless functional or emotional disturbances develop. An autosomal recessive pattern of inheritance is suggested for these cases, although autosomal dominant transmission has been previously established.
The roles of the N‐terminal portions of various tachykinins in promoting salivation
Authors: Higa K , Gao C , Motokawa W , Abe K 
Published: November 2004

OBJECTIVES: In order to determine the active sites for salivation of various tachykinins, the regulatory roles of the N‐terminal portion of various newly‐synthesized tachykinins were studied after i.p. injection of rats using the submandibular glands as model organs.METHODS: N‐shortened oligopeptides from kassinin, eledoisin, neurokinins A (NKA) and NKB were synthesized by the multipin peptide synthesis method. Amino acids were eliminated one by one to form octa‐ to undeca‐peptides adjoining the inactive or less active heptapeptides and various heptapeptides, in which an amino acid in position 8 (Xaa8 ), numbering as in an undecapeptide, was replaced with Tyr, Phe, Ile or Val.RESULTS: The N‐terminal amino acids in positions 1 to 4 could be activators or inhibitors, depending on whether the C‐terminal heptapeptide was inactive or less active. The Xaa8 residue, in combination with amino acids in positions 5 and 6, seemed to be very important in determining the sialogogic activity of a heptapeptide. The discrimination between NKA and NKB appeared due to the N‐terminal amino acid sequence in positions 1 to 4 including Phe or Ser in position 6.CONCLUSIONS: It is concluded that the N‐terminal amino acids in positions 1 to 4 serve as either activators or inhibitors depending upon the sialogogic activity of the C‐terminal heptapeptide, in which particular amino acids in positions 5, 6 and 8 regulate its activity.
Permeability barrier properties of oral keratinocyte cultures: a model of intact human oral mucosa
Authors: Selvaratnam L , Cruchley AT , Navsaria H , Wertz PW , Hagi‐Pavli EP , Leigh IM , Squier CA , Williams DM 
Published: November 2004

OBJECTIVES: The aim of this study was to establish whether an in vitro model of human oral mucosa had similar permeability characteristics to normal oral mucosa. Such a model would have considerable value as an alternative to the use of mucosal biopsies in studies of transmucosal drug delivery.MATERIALS AND METHODS: Keratinocytes obtained from buccal mucosa, hard palate and abdominal skin were seeded onto inert collagen membranes (Cellagen Discs) or dead deepidermised dermis (DDED) and grown either as submerged or air‐liquid interface cultures. Subsequently the ultrastructural characteristics, permeability to water and barrier lipid content of the epithelial cultures were assessed and compared with samples of intact mucosa and skin.RESULTS: All the cultures stratified into multilayered epithelia and displayed features of differentiation including tonofilaments, desmosomes and membrane coating granules. The permeability characteristics and barrier lipid content of the oral mucosal cultures resembled those of intact mucosa. By contrast, pidermal keratinocytes failed to produce a permeability barrier comparable with that of skin and had low levels of barrier associated lipids.CONCLUSIONS: Cultures of human oral mucosal keratinocytes obtained from healthy adults develop similar permeability properties and barrier lipid composition to their site of origin. This model system may be useful for the evaluation of local and systemic oral mucosal drug delivery.
CT-based evaluation of axillary sentinel lymph node status in breast cancer: value of added contrast-enhanced study
Authors: Yuen S. , Yamada K. , Goto M. , Sawai K. , Nishimura T. 
Published: November 2004

Purpose: To evaluate the diagnostic reliability of CT-based sentinel lymph node (SLN) size criteria for selecting the candidates for direct axillary dissection without SLN biopsy and to determine the value of added contrast-enhanced study. Material and Methods: Breast cancer patients ( n=107) underwent triple phasic (1-min, 3-min, 8-min) contrast-enhanced 5 mm-computed tomography (CT) of the breasts and axillae. In the CT image, the most inferior lymph node in the axilla was designated the SLN. Axillary status was judged based on SLN size criteria. CT density, enhancement rate, and peak enhancement time of each SLN were correlated with histopathological results. Results: SLN size criteria demonstrated a sensitivity of 76% and a positive predictive value of 95% in predicting SLN metastasis. The density values at each scanning time-point were significantly different for metastatic and non-metastatic SLN. However, their enhancement rates differed significantly only at 1 min. Their peak enhancement occurred primarily at 1 min. The use of contrast-enhancement criteria improved the predictive sensitivity, but failed to decrease the false-positive rate of the SLN size criteria. Conclusion: The enhancement rate at 1 min proved to be the most useful parameter in contrast-enhanced CT studies; however, it failed in improving the accuracy of the SLN size criteria.
Magnetic resonance microscopic images with 50-mm field-of-view of the medial aspect of the knee
Authors: Niitsu M. , Ikeda K. 
Published: November 2004

Purpose: To demonstrate the utility of microscopic images with field-of-view of 50 mm in delineation of the medial aspect of the knee, including fascial plane, superficial and deep layers of the medial collateral ligament (MCL), and the medial meniscus. Material and Methods: Using a phantom, the signal-to-noise ratio (SNR) of a magnetic resonance (MR) microscopy coil with a diameter of 47 mm was calculated and compared with that of a regular coil. Four cadaveric knees were imaged by microscopy and resected to confirm the morphologies. Sixty-nine patients with internal derangement were examined by routine and microscopic imaging. Comparing the paired images for delineation of the above-mentioned structures, a qualitative image analysis was performed. Results: SNRs of the MR microscopy coil were higher than those of the regular coil. MR microscopy readily demonstrated the multilayered appearance of the fascial plane and both layers of the MCL in cadavers and patients. In cases with MCL tears, ruptured stumps were identified by microscopy. MR microscopy delineated tiny cleavages in cases with meniscal tears. The mean values of qualitative evaluation of the MR microscopy were significantly higher than those of the routine imaging. Conclusion: High-resolution imaging delineated fine structures of the medial aspect of the knee.
Computed tomography perfusion of the liver: assessment of pure portal blood flow studied with CT perfusion during superior mesenteric arterial portography
Authors: Kojima H. , Tanigawa N. , Komemushi A. , Kariya S. , Sawada S. 
Published: November 2004

Purpose: To quantitatively assess the portal component of hepatic blood flow using computed tomography (CT) perfusion studies during superior mesenteric arterial portography. Material and Methods: Thirty-four patients with hepatocellular carcinoma and liver cirrhosis (LC) and 13 patients with liver metastasis without chronic liver disease were enrolled in this study. Ten milliliters of a non-ionic contrast medium (150 mgI) was injected at a rate of 5 ml/s via a catheter placed in the superior mesenteric artery. Single-slice cine CT images at the level of the main trunk or the right/left main trunk of the portal vein were acquired over 40 s. The deconvolution method was then used on these CT images to measure blood flow (BF), blood volume (BV), and mean transit time (MTT) in (a) liver parenchyma in patients with HCC and liver cirrhosis; (b) liver parenchyma in patients with liver metastasis without cirrhosis; (c) directly in the HCC; and (d) directly in one of the metastases. Results: In 34 LC patients (a), BF, BV, and MTT in the liver parenchyma were 44.7±24.5 ml/min/100 g, 3.9±2.4 ml/100 g, and 10.9±5.5 s, respectively. In 13 patients without cirrhosis (b), BF, BV, and MTT in the liver parenchyma were 89.6±52.0 ml/min/100 g, 6.3 ±3.2 ml/100 g, and 8.7±3.6 sec, respectively. A significant difference in BF and BV was seen in patients with liver cirrhosis compared to those without cirrhosis. BF, BV, and MTT measured directly in HCC (c) were 6.5±4.5 ml/min/100 g, 0.4±0.4 ml/100 g, and 3.0±3.1 sec respectively, and BF, BV, and MTT in liver metastases (d) were 19.3 ± 21.7 ml/min/100 g, 0.6±0.8 ml/100 g, and 1.8±1.6 s, respectively. Conclusion: CT perfusion studies during superior mesenteric arterial portography allow quantitative assessment of pure portal blood flow in the liver.
Ultrasonography in follow-up of soft tissue augmentation of the face with synthetic materials: a pilot study
Authors: Giovagnorio F. , Drudi F. M. , Valentini C. , Paonessa A. 
Published: November 2004

Purpose: To assess ultrasonography in the evaluation of reactions after soft tissue augmentation of the face with synthetic materials. Material and Methods: Six female patients (mean age 39±8 years) treated for facial tissue augmentation noticed unpleasant or painful effects in the intervention site after a mean of 24 months were evaluated with ultrasonography. Two patients had been treated with injections of microparticles, two with Gore-Tex implants, and two had been injected with liquid silicone. Fifteen female patients (age 27-55 years, mean 41±14 years) who had received the same treatment 14-48 months before without any complications were also evaluated and used as controls. Biopsy was performed in all patients, while four underwent re-intervention. Results: In all patients with Gore-Tex implants, a thick, homogeneous hypoechoic halo was seen surrounding the implants. Small hypoechoic nodules were noticed in the patients who had been treated with microparticles and with liquid silicone. In two cases treated with liquid silicone the subcutaneous tissue was invaded by an irregular area of marked inhomogeneity. Conclusion: Sonography must be considered the method of choice for producing instrumental evidence of foreign body reactions after soft tissue augmentation of the face with synthetic materials.