bluuebunny/crossref_metadata_2025 huggingface dataset:
Identification of guttation fluid proteins: the presence of pathogenesis‐related proteins in non‐infected barley plants
Authors: Grunwald Ingo , Rupprecht Ines , Schuster Gadi , Kloppstech Klaus
Published: September 2003

The main driving force behind water transport in plants is the air's low water potential. In the presence of high humidity, the transpiration process is halted and water transport is mainly sustained by the root pressure. The surplus of water following the removal of essential components (e.g. salts) is excreted by the plant via guttation through the hydathodes. When guttation occurs, the plant surface is wetted. These are the conditions that will allow epiphytic living, motile bacteria to move and to eventually enter the plant's interior via the hydathodes. The question arose as to whether the plant has developed a protection mechanism against motile bacteria in the vicinity of the hydathodes. Such a protection mechanism could use the well known pathogenesis‐related (PR) proteins. Indeed, an analysis of the guttation fluid using one‐ and two‐dimensional electrophoresis showed a clustering of approximately 200 proteins, primarily with isoelectric points in the acidic pH. Proteins identified using electrospray ionization mass spectroscopic analysis and western blot analysis belong mostly to the family of PR‐proteins suggesting a role in plant protection against invaders. The protein profile of the guttation fluid was remarkably modified by treating plants with methyl jasmonic acid suggesting that the protein composition of the guttation fluid is controlled by internal and/or external stimuli.
PCEA compared to continuous epidural infusion in an ultra‐low‐dose regimen for labor pain relief: a randomized study
Authors: Ledin Eriksson S. , Gentele C. , Olofsson C. H.
Published: September 2003

Background:  Patient‐controlled epidural analgesia, PCEA, has been introduced in obstetric analgesia during the past decade. Many studies have shown that the consumption of analgesic is reduced when the parturient requests her own doses. This study investigates whether this is also true when using an ultra‐low‐dose regimen.

Methods:  Eighty parturients were prospectively randomized to have either continuous epidural infusion (CEI) with ropivacaine 1 mg ml−1 and sufentanil 0.5 µg ml−1, 6 ml h−1, or patient‐controlled epidural analgesia (PCEA) with 4 ml demand doses with 20 min' lockout. The epidural start dose was the same for the two groups, 8 ml of the study solution. Rescue bolus doses were given when needed and the continuous infusion could be increased, which gave the two groups the same maximum possible dose. The consumption of local ropivacaine in combination with sufentanil during labor was registered. Hourly assessments made throughout labor included pain intensity documented with visual analog score, VAS, the patient's opinion on epidural efficacy, motor block, pruritus and need for nitrous oxide.

Results:  The PCEA group consumed 33% less of the study solution than the CEI group. Mean total consumption was 35 ml (SD 18.0) and 52 ml (SD 19.6), respectively. Mean hourly consumption was 5.2 ml h−1 (SD 2.54) in the PCEA group and 6.9 ml h−1 (SD 1.31) in the CEI group. There were no significant differences between the two groups in pain relief, epidural efficacy, side‐effects or obstetric outcome.

Conclusion:  PCEA reduces doses compared to continuous infusion even when ultra‐low‐dose local anesthetic with opioid is used. The PCEA technique provides individual titration of doses to an acceptable degree of pain relief.
Acupuncture facilitates neuromuscular and oculomotor responses to skin incision with no influence on auditory evoked potentials under sevoflurane anaesthesia
Authors: Kvorning N. , Christiansson C. , Åkeson J.
Published: September 2003

Background:  More sevoflurane was recently found to be required to prevent movement in response to surgical incision in anaesthetized patients subjected to electro‐acupuncture (EA) than to sham procedures. The present study was designed to compare differences in movement, dilatation of the pupils, divergence of the eye axes and activity of auditory evoked potentials (AEPs) between patients given and those not given EA under standardized sevoflurane anaesthesia.

Methods:  Neuromuscular, oculomotor and AEP responses to skin incision were assessed with and without a bilateral 2‐Hz burst EA in patients under steady‐state anaesthesia maintained with 1.8% of sevoflurane. Forty‐five healthy patients, scheduled for laparoscopic sterilization, were randomized for EA (n = 22) or sham (n = 23) procedures between induction of anaesthesia and start of surgery. Middle latency AEP activity was recorded and interpreted by the A‐line ARX (autoregression with exogenous input) index (AAI).

Results:  More acupuncture than sham patients were found to respond to skin incision with movement of the neck or limbs (77% vs. 43%; P = 0.021), dilatation of the pupils (77% vs. 39%; P = 0.001) and divergence of the eye axes (72% vs. 39%; P = 0.023), whereas there was no difference in AAI response.

Conclusion:  Electro‐acupuncture facilitates physiological responses to nociceptive stimulation under sevoflurane anaesthesia. Differences in neuromuscular and oculomotor responses between acupuncture and sham patients under general anaesthesia are probably not associated with interaction between EA and the depth of anaesthesia, as AEP activity was similar in the two groups.
Dorsal flexion of head and neck for rigid oesophagoscopy – a caution for hidden foreign bodies dropped into the epipharynx
Authors: Gitzelmann C. A. , Gysin C. , Weiss M.
Published: September 2003

A 32‐month‐old girl presented with a swallowed coin in the mid‐oesophagus verified by chest radiography. Rigid oesophagoscopy was performed under general anaesthesia with muscle paralysis and tracheal intubation with dorsal flexion of the head and neck. The coin could be grasped using ‘optical forceps’. When the oesophagoscope‐forceps assembly was removed, the coin had disappeared. Repeated explorations of the oesophagus including direct laryngoscopy were unsuccessful. A further direct laryngoscopy, while placing the head in the neutral position, revealed the coin just dislodging from the epipharyngeal space in the hypopharynx, from where it was removed with a Magill forceps (Arnold Bott, Glattbrugg, Switzerland).

Dorsal flexion of the head and neck during foreign body removal may allow entry of the foreign body or easily fragmented foreign bodies into the epipharyngeal cavity. Exploration is recommend using naso‐pharyngeal suction and direct laryngoscopy with the head in the neutral position before tracheal extubation in order to avoid acute airway obstruction.
Influence of PRP on autogenous sinus grafts
Authors: Jakse Norbert , Tangl Stefan , Gilli Renate , Berghold Andrea , Lorenzoni Martin , Eskici Antranik , Haas Robert , Pertl Christof
Published: September 2003

Abstract: Since platelet ‐rich plasma (PRP) has been introduced to the field of oral surgery, it has become a widely accepted additive for bone regeneration treatment. The aim of this study was to evaluate the regenerative capacity of PRP in a sinus graft study on sheep. Twelve adult sheep underwent a bilateral sinus floor elevation procedure with cancellous bone from the iliac crest. Unilaterally, PRP was administrated to the bone graft. After 4 (six sheep) and 12 weeks (six sheep), bone biopsies were obtained from each site. With histomorphometric analysis we evaluated both the percentage of newly formed bone within the grafted site and the percentage of the contact area between the grafted bone and the newly formed bone. After 4 weeks the mean proportion of newly formed bone on the control side was 26.1%, whereas it was 29.2% on the test side. After 12 weeks it was 46.9% on the control side and 51.1% on the test side. The area of contact between the graft and the newly formed bone was 73.0% on the control side and 78.5% on the test side after 4 weeks, and 87.2% on the control side and 90.1% on the test side after 12 weeks. A statistical analysis did not reveal significant differences between the control and the test side. The results of the present experimental study show a regenerative capacity of PRP of quite low potency. Further basic research is needed to investigate more profoundly the possibilities of PRP in bone regeneration.
Experimental sinus grafting with the use of deproteinized bone particles of different sizes
Authors: Xu Hui , Shimizu Yoshinaka , Asai Sumito , Ooya Kiyoshi
Published: September 2003

Abstract:  This study compared the osteoconductive capability of deproteinized bone particles of two different sizes (300–500 and 850–1000 μm) in rabbits undergoing maxillary sinus lift. Histologically, deproteinized bone particles of both sizes induced osteoconduction 1 week after implantation. Bone initially formed at the sinus wall and proliferated into the center of the augmented sinus cavity. In the small‐particle group, newly formed bone showed many interconnections and appeared in most areas of the cavity 8 weeks after implantation. In the large‐particle group, newly formed bone showed limited intercommunications, and the center of the sinus cavity contained fibrous connective tissue with no evidence of ossification 8 weeks after implantation. Histomorphometric analysis revealed a significantly higher density of newly formed bone in the small‐particle group than in the large‐particle group both 4 and 8 weeks after implantation. The total newly formed bone–particle contact length was also significantly higher in the small‐particle group. The total surface length of the small particles was larger than that of the large particles, but the ratio of the newly formed bone–particle contact length to the total particle surface length did not differ significantly between the groups at any time. The interparticular spaces of the small particles were larger than those of the large particles. The bone area ratio in the interparticular spaces of the small particles was significantly higher than that of the large particles both 4 and 8 weeks after implantation. We conclude that graft bone particle size and interparticular space are important determinants of osteoconduction.
Brånemark and ITI dental implants in the human bone‐grafted maxilla: a comparative evaluation
Authors: Pinholt Else M.
Published: September 2003

Abstract: The development of new characteristics concerning implant surface makes it interesting to clinically compare different implant systems in the bone‐grafted maxilla. The aim of this evaluation was to compare clinical data of a two‐staged procedure on the augmented extremely atrophic maxilla using either Brånemark‐ or ITI‐fixures. In 25 patients (18 females, seven males) the severely atrophied maxilla was reconstructed with autogenous iliac or mandibular bone and either Brånemark or ITI implants. Seventy‐eight Brånemark implants and 80 SLA‐ITI implants were inserted in the augmented bone and the patients were followed between 20 and 67 months post implantation. The bone graft was transplanted to add bony volume in the maxillary sinus, the anterior floor of the nose and/or the alveolar ridge. After a healing period of 4½ months, dental implants were inserted and left for healing for 8 months. Twelve consecutive patients received machine‐surfaced Brånemark fixtures and 13 consecutive patients received SLA‐ITI fixtures. Gradual loading was applied after healing abutment application. After 6 months the permanent prosthetic reconstruction was provided to the patient, either as a fixed or removable bridge. Comparison in survival rate was performed: 15 machined Brånemark fixtures were lost, resulting in an overall survival rate of 81%. Two ITI fixtures were lost, resulting in an overall survival rate of 98%. The results of this evaluation show that sandblasted large grit acid etched surface‐treated ITI implants has a significant higher survival rate than machine‐surfaced Brånemark implants in autogenous grafted maxillary bone.
An oral health promotion program for an urban minority population of preschool children
Authors: Harrison Rosamund L. , Wong Tracy
Published: September 2003

Abstract – The objective of this project was to design, implement and evaluate an oral health promotion program for inner‐city Vietnamese preschool children in Vancouver, British Columbia, Canada. The project comprised of four general phases: information‐gathering, project planning, project implementation, and project evaluation. The information‐gathering phase of the project demonstrated extensive tooth decay in young children, bottle use during the day and during sleep‐time long past recommended weaning age, and a belief of many parents that primary teeth were not important. Based on this information, the project planning committee designed a program that featured one‐to‐one counseling supported by community‐wide activities. A Vietnamese lay health counselor provided counseling to mothers with telephone follow‐up that coincided with scheduled infant immunization visits to a twice‐monthly Child Health Clinic for Vietnamese families. At all the follow‐up assessment clinics scheduled over the 7‐year duration of this continuing project, mothers who had had more than one counseling visit reported significantly less use of sleep‐time and daytime bottles for their children, and their children demonstrated significantly reduced prevalence of caries compared to similarly aged children at baseline. One‐to‐one counseling with regular follow‐up provided by a lay person of similar background and culture to the participants is an effective way to facilitate adoption of healthy behaviors and to improve oral health of children.
Agreement between mothers and children aged 11–14 years in rating child oral health‐related quality of life
Authors: Jokovic Aleksandra , Locker David , Stephens Marlene , Guyatt Gordon
Published: September 2003

Abstract  – 

Objectives: To assess the agreement between mothers and children concerning the child's oral health‐related quality of life.

Methods: A total of 42 pairs of mothers and children aged 11–14 years with oral and orofacial conditions completed the parental (PPQ) and child (CPQ11–14) components of the Child Oral Health Quality of Life Questionnaire. The PPQ and CPQ11–14 are analogous questionnaires with 31 common items. Agreement between overall and subscale scores derived from the questionnaires were assessed in comparison and in correlation analyses. The former used mean directional differences between mothers and children to assess bias and mean absolute differences to assess agreement at the group level. The latter used intraclass correlation coefficients (ICCs) to assess agreement at the level of individual mother–child pairs.

Results: At the group level, agreement between mothers and children was good. There was little evidence of bias in mothers' reports compared to those of their children. The mean absolute difference in overall scores constituted 9% of the possible range of scores. However, the significance of this difference is difficult to interpret. The ICC for overall scores was 0.70 indicating substantial agreement between mother and child pairs. However, the ICCs for the emotional and social well‐being subscales indicated moderate agreement only. There was a suggestion that the level of agreement varied according to the characteristics of the child.

Conclusion: Although mothers may be used as proxies for their children in some circumstances and for some purposes, the views of both should be obtained in order to fully represent child oral health‐related quality of life.
Relationship of dental status, sociodemographic status, and oral symptoms to perceived need for dental care
Authors: Heft Marc W. , Gilbert Gregg H. , Shelton Brent J. , Duncan R. Paul
Published: September 2003

Abstract  – 

Objective:  Previous studies have noted a discrepancy between clinically determined oral health status (normative need), patients' perceptions, and perceived significance of dental signs and symptoms. Our objective was to quantify the relationships between normative need and self‐reports to improve our understanding of the factors that contribute to perceived need for care.

Methods:  Clinical examination and questionnaire data were derived from the Florida Dental Care Study, a study of oral health and dental care, in a representative sample of community‐dwelling adults aged ≥45 years. The questionnaire provided information about presence of signs and symptoms, self‐ratings of oral health, perceived need for dental care, and sociodemographic status (SDS). Perceived need was measured on a 4‐point nominal scale.

Results:  Self‐reported broken filling, broken denture, cavities, loose tooth, teeth that look bad, and toothache were strongly associated with self‐reported perceived need for dental care. Satisfaction with dental health was also associated with perceived need, but self‐rated oral health was not. Most measures of SDS were associated with perceived need. However, in a single multiple regression, with self‐reported signs and symptoms accounted for, race, age group, sex, and educational attainment were not significantly associated with a currently perceived dental problem.

Conclusions:  Certain dental signs and symptoms were significantly associated with perceived need for dental care, as were certain aspects of SDS; even once differences in dental signs and symptoms had been taken into account. Disaggregating measurement of perceived need from a single dichotomous (‘yes/no’) scale to a 4‐point nominal scale was elucidative.
Caries incidence rates in Swedish adolescents and young adults with particular reference to adjacent approximal tooth surfaces: a methodological study
Authors: Stenlund Hans , Mejàre Ingegerd , Källestål Carina
Published: September 2003

Abstract  – 

Objectives:  The objective was to assess the dependence of the caries status of the adjacent approximal surface on the incidence of approximal caries.

Methods:  At baseline, the material consisted of a cohort of 536 Swedish children. The individuals were followed through annual bitewing radiographs from the age of 11–13 to 21–22 years. A radiographic scoring system was used to assess the caries status of the surfaces: scores 0 and 1 = sound surface to score 4 = caries in the outer half of the dentine. A model was used to calculate the dependence of the caries status of adjacent approximal tooth surfaces. The unit of analysis was a pair of adjacent approximal surfaces and in all, 12 pairs of posterior approximal surfaces were analysed.

Results:  The individual caries rates of the 24 posterior approximal surfaces ranged from 1.3 to 8.3 new caries lesions per 100 tooth surface‐years. The caries rate of an approximal tooth surface depended on the caries status of the adjacent surface: a sound surface next to a sound surface had a relatively small risk of developing caries, while the risk increased 1.6–32.3 times if the adjacent surface was in a caries state as judged radiographically. The distal surface of the first molar developed caries more often than the mesial surface of the second molar.

Conclusions:  The caries rate of an approximal tooth surface was 1.6–32.3 times higher if the adjacent surface was in a caries state compared to when the latter was sound.
Time and duration of eruption of first and second permanent molars: a longitudinal investigation
Authors: Ekstrand Kim Rud , Christiansen Jette , Christiansen Mauri Erik Christian
Published: September 2003

Abstract  – 

Objective:  The aim of this study was to investigate the variation in (i) the time (age) of eruption and (ii) the duration of the eruption of first (M1) and second (M2) permanent molar teeth. Finally, the study also provides data about the association between time of eruption of the first of the M1s and the first of the M2s.

Methods:  The study was carried out in Nexö Public Dental Health Service, Denmark. All children who, in a period of 12 months, had the first of their M1s or M2s recorded as erupted and the occlusal surface still partly covered by gingiva formed the study groups (N = 69 and 112 children, respectively). The continued eruption of all four molar teeth was recorded at recall intervals not exceeding 4 months until functional occlusion was obtained.

Results:  First permanent molars: eruption time – girls: from the age of 5 years and 3 months to 7 years and 8 months (mean 6.1 years); boys: from 5 years and 2 months to 7 years and 10 months (mean 6.3 years). The duration of eruption – girls: from 5 to 32 months (mean 15.4 months); boys: from 7 to 28 months (mean 15.0). Second permanent molars: eruption time – girls: from the age of 8 years and 11 months to 14 years and 4 months (mean 11.3 years); boys: from 9 years and 11 months to 13 years and 11 months (mean 12.0 years). The duration of eruption – girls: from 12 to 44 months (mean 27.1 months); boys: from 9 to 45 months (mean 27.9 months). No correlation was found between the time of eruption and the duration of eruption of M1 or M2. There was a strong positive association between the time of eruption of the M1s and the M2s (rs = 0.81).

Conclusions:  A tremendous variation was found in time of eruption and in duration of eruption of permanent molars. This variation highlights the importance of individualizing caries preventive strategies for children.
Patient participation during dental consultations: the influence of patients' characteristics and dentists' behavior
Authors: Schouten Barbara C. , Hoogstraten Johan , Eijkman Michiel A. J.
Published: September 2003

Abstract  – 

Objective:  This study examined the influence of the following variables on patients' information‐seeking and participating behavior during emergency treatment: patients' preferences for information and participation, patients' coping style, patients' socio‐demographic variables, and dentists' communicative behavior.

Methods:  The sample consisted of 83 patients receiving emergency care from 13 different dentists. Consultations were videotaped in order to assess dentists' and patients' behavior. Dentists' communicative behavior was coded by means of the Communication in Dental Settings Scale (CDSS); scores for patients' behavior included the number and nature of questions asked during the consultation, attempts to offer diagnoses, and whether or not patients made the decision to undergo treatment themselves. At home, patients filled out a questionnaire that included scales to measure their preference for information and participation and other background variables.

Results:  Results showed that patients' desire for information and participation, together with other variables, was not reflected in their overt behavior. Furthermore, dentists' communicative behavior was unrelated to patients' information‐seeking and participating behavior.

Conclusions:  Scores on the CDSS show that still there is a discrepancy between the legal prerequisites of information‐giving and emergency dental practice. Therefore, dentists' information‐giving behavior should be improved in order to enhance the patients' right to make informed decisions.
Tobacco prevention in Swedish dental care
Authors: Helgason Ásgeir R. , Lund Karl E. , Adolfsson Jan , Axelsson Susanna
Published: September 2003

Abstract –  Objective:  To assess tobacco prevention in Swedish dental care and to identify barriers. Also, to investigate whether dentists and dental hygienists were familiar with recently published review of smoking cessation methods.

Methods:  A questionnaire was mailed to all 353 dental hygienists and 528 dentists in Stockholm County.

Results:  The overall response rate was 61% for the dentists and 67% for the dental hygienists. Nearly all considered smoking to be a major health issue, but one out of two was not convinced that smokeless tobacco use was a major health problem. A small minority was routinely engaged in cessation support. However, on the aggregate level, the active dentists and hygienists advised annually approximately 70 000 and 40 000 smokers, respectively. The main barrier to cessation counseling was lack of smoking cessation experts to refer to and was followed by a lack of reimbursement, a lack of knowledge, time constraints, and a feeling of inadequacy. Also, one out of two dentists and 3 out of 10 hygienists did not see it as a part of their job to help patients stop smoking. Approximately 10% in both groups made use of the review of smoking cessation methods. Fifty per cent of these had increased their cessation consultations by an average of 30% because of the guidelines. On the average, dentists and hygienists had spent approximately 1.4 and 2.9 h, respectively, during the previous month on all smoking cessation activities.

Conclusions:  Despite several barriers, there is an excellent potential for a more active role in tobacco cessation counseling in Swedish dental care.
A 5‐year evaluation of two glass‐ionomer cements used as fissure sealants
Authors: Pardi Vanessa , Pereira Antonio Carlos , Mialhe Fábio Luiz , De Castro Meneghim Marcelo , Ambrosano Gláucia Maria Bovi
Published: September 2003

Abstract  – 

Objective: To evaluate the retention and caries preventive effect of two glass ionomers used as fissure sealants: one resin modified glass ionomer (A) and one conventional glass‐ionomer cement (B).

Samples and methods: The permanent first molars of 100 children, 6–8 years of age at the start of the study, were sealed. Material A was applied on one side (right side, upper, and lower) and material B was applied on the contralateral side (left side, upper, and lower) of the mouth. The control group was composed of 108 children who did not receive fissure sealant but received oral health education. After 5 years, 64.0% of the children of the experimental group and 73.0% of the children of the control group were available for reexamination.

Results: Material A was completely lost in 74.2% and material B in 89.0% (Wilcoxon matched pairs test, P < 0.05). Total retention rate was 1.6% for materials A and B. After 5 years, caries increment was 21.5% for the experimental group and 34.2% for the control group (χ2‐test, P < 0.05).

Conclusion: Sealing pits and fissures with glass‐ionomer cements was effective in preventing caries.
Gender differences in burnout among Dutch dentists
Authors: Brake Hans te , Bloemendal Evelien , Hoogstraten Johan
Published: September 2003

Abstract  – 

Objectives: Differences between the sexes in the manifestation of burnout have been reported for different occupational groups. Although some gender‐specific explanations for this finding have been forwarded, there is a paucity of studies in which the relation with other work‐related gender differences is examined. The objective of this study was to analyze gender differences in burnout among dentists and to identify possible concomitant factors.

Methods: Male (n = 411) and female (n = 81) Dutch dentists filled out the Dutch version of the Maslach Burnout Inventory (MBI) together with several health and work‐related questionnaires.

Results: Results showed male dentists to report a higher score on the depersonalization dimension of the MBI than did female dentists. No gender differences were found on the other dimensions (i.e. emotional exhaustion and personal accomplishment). Moreover, no gender‐related differences in experienced work‐stress or health‐related aspects were found. It was found, however, that male dentists put in working hours and see more patients per week when compared to female dentists. Also, a difference in mean age was found. Our main finding was that the difference in depersonalization disappears when controlling for working hours and age.

Conclusions: Gender differences in burnout among dentists do exist. However, our results indicate that underlying factors, such as working hours, have a profound effect on these differences. These results can have direct practical consequences, for instance, in distinguishing between groups concerning the way burnout scores should be interpreted.
Chewing ability of subjects with shortened dental arches
Authors: Sarita Paulo T. N. , Witter Dick J. , Kreulen Cees M. , Van't Hof Martin A. , Creugers Nico H. J.
Published: September 2003

Abstract  – 

Objectives:  The objective was to study chewing ability in subjects with shortened dental arches in Tanzania.

Methods:  A sample of 725 adults with shortened dental arches comprising intact anterior regions and 0–8 occluding pairs of posterior teeth and 125 adults with complete dental arches were recruited. Subjects were classified into nine categories according to arch length and symmetry. Chewing ability was investigated by interview on chewing complaints and on perceived difficulty of chewing 20 common Tanzanian foods, 12 soft, and 8 hard.

Results:  Categories with extreme shortened arches (0–2 pairs of occluding premolars) reported most frequent (95–98%) and most severe complaints (‘cannot chew all foods’ or ‘have to use special or specially prepared food’). Categories with intact premolar regions and at least one occluding pair of molars had nearly no complaints (95–97%). The other arch categories had an intermediate volume of complaints (33–54%). Perceived difficulty of chewing deteriorated with a decrease of occluding pairs of teeth. Subjects with 0–2 pairs of occluding premolars had major difficulties with chewing. Subjects with 3–4 pairs of occluding premolars or asymmetric arches comprising a short side with none or one pair of premolars and a long side including at least one occluding pair of molars had more difficulties with chewing compared to subjects with more complete dental arches. As a whole, they perceived for hard foods, ‘minor problems, not adapted’.

Conclusions:  Shortened dental arches with intact premolar regions and at least one occluding pair of molars provide sufficient chewing ability. Shortened arches with 3–4 pairs of occluding premolars and asymmetric arches with a long side result in impairment of chewing ability, especially for hard foods. In extremely shortened arches comprising 0–2 occluding premolars, chewing ability is severely impaired.
Cryotherapy modifies synthetic activity and differentiation of keloidal fibroblasts in vitro
Authors: Dalkowski A. , Fimmel S. , Beutler C. , Zouboulis Ch. C.
Published: September 2003

Abstract:  In order to obtain a persuasive explanation for the beneficial clinical effect of cryotherapy on keloids, we developed a reproducible model to apply freezing temperatures on cell cultures, and investigated their influence on proliferation, viability, synthetic activity and differentiation of dermal fibroblasts in vitro. Cell cultures were established from 13 untreated keloids and 10 healthy skin specimens matched for age and skin localization to the donors. No significant influence of cell freezing on the proliferation rates of both keloidal and normal fibroblasts was documented, but mechanical cell destruction with a wide variation in lethality rates (29% average lethal effect on keloidal fibroblasts and 41% on normal ones) was observed. When comparing specimens of keloidal and normal tissue derived from the same four donors, the keloidal fibroblasts were similar regarding their synthetic activity but presented enhanced tenascin‐C expression compared with the normal fibroblasts. After cryotherapy, delayed collagen III increase was detected in both cell types (P = 0.03). The collagen III/collagen I ratio increased from 1.6 to 2.8 in the keloidal and only from 1.9 to 2.2 in the normal fibroblasts after subcultivation. Normal fibroblasts exhibited a significantly lasting increase in fibronectin synthesis after freezing (P = 0.03). The intensity of staining against tenascin‐C was decreased in five of nine keloidal fibroblast cultures after cryotherapy (P < 0.05) but increased in four of five normal fibroblast cultures (P = 0.016), so that the intensity of tenascin‐C staining after freezing became identical in both cell types. Immunoblot studies in four patients and two controls confirmed a temporary decrease of tenascin‐C in keloidal but not in normal fibroblasts immediately after freezing. Significantly decreased staining with two markers of myogenic differentiation, myosin in keloidal fibroblasts (P = 0.002) and desmin (P = 0.007) in normal fibroblasts, could also be detected after treatment. In summary, with the help of a model for controlled cell freezing in vitro, cryotherapy was found to modify collagen synthesis and differentiation of keloidal fibroblasts.
Strategy to assess the efficiency of U1 RNA‐hammerhead ribozyme constructs using GFP‐tagged targets
Authors: Cserhalmi‐Friedman Peter B. , Djabali Karima , Dietz Harry C. , Christiano Angela M.
Published: September 2003

Abstract: The application of ribozymes for gene therapy of autosomal dominant diseases has become popularized in recent years. Further this technology has widespread utility in the treatment of any disease, acquired or inherited, by inhibition of gene expression. The design of ribozymes is usually accomplished using computer assisted design programs, however they are not very useful in predicting the behavior of the ribozyme in the in vivo setting. To overcome this technical challenge, we developed a simple in vivo strategy to accurately assess the efficiency of ribozyme cleavage that significantly enhances the computer based design programs.
Molecular genetics of Xeroderma pigmentosum variant
Authors: Gratchev Alexei , Strein Pamela , Utikal Jochen , Goerdt Sergij
Published: September 2003

Abstract:  Xeroderma pigmentosum (XP) is an autosomal recessive disease characterized by sun sensitivity, early onset of freckling and subsequent neoplastic changes on sun‐exposed skin. Skin abnormalities result from an inability to repair UV‐damaged DNA because of defects in the nucleotide excision repair (NER) machinery. Xeroderma pigmentosum is genetically heterogeneous and is classified into seven complementation groups (XPA‐XPG) that correspond to genetic alterations in one of seven genes involved in NER. The variant type of XP (XPV), first described in 1970 by Ernst G. Jung as ‘pigmented xerodermoid’, is caused by defects in the post replication repair machinery while NER is not impaired. Identification of the XPV gene was only achieved in 1999 by biochemical purification and sequencing of a protein from HeLa cell extracts complementing the PRR defect in XPV cells. The XPV protein, polymerase (pol)η, represents a novel member of the Y family of bypass DNA polymerases that facilitate DNA translesion synthesis. The major function of polη is to allow DNA translesion synthesis of UV‐induced TT‐dimers in an error‐free manner; it also possesses the capability to bypass other DNA lesions in an error‐prone manner. Xeroderma pigmentosum V is caused by molecular alterations in the POLH gene, located on chromosome 6p21.1–6p12. Affected individuals are homozygous or compound heterozygous for a spectrum of genetic lesions, including nonsense mutations, deletions or insertions, confirming the autosomal recessive nature of the condition. Identification of POLH as the XPV gene provides an important instrument for improving molecular diagnostics in XPV families.
Lack of clinicopathologic correlation in the diagnosis of oral lichen planus based on the presently available diagnostic criteria and suggestions for modifications
Authors: Van Der Meij E. H. , Van Der Waal I.
Published: September 2003

Introduction:  Confirmation of a clinical diagnosis of oral lichen planus (OLP) by means of histopathologic study of a biopsy specimen is generally advised. However, hardly any data exist about the correlation between clinical and histopathologic diagnoses of OLP. The aim of the present investigation was to study the correlation between the clinical and histopathologic assessment of OLP, and to propose diagnostic refinements, if appropriate.

Methods:  Clinical and histopathologic data of two previously published studies were used for this purpose. The number of clinical cases in which all clinicians agreed as well as the number of microscopic slides on which all reviewing pathologists agreed were calculated and compared with each other in order to assess the clinicopathologic correlation.

Results:  In 42% of the cases in which all clinicians agreed about the clinical diagnosis being diagnostic of OLP, there appeared to be no consensus on the histopathologic diagnosis. Conversely, in 50% of the cases in which all pathologists agreed about the histopathologic diagnosis being diagnostic of OLP there was a lack of consensus on the clinical diagnosis.

Conclusion:  Based on the findings of the present study, there appears to be a lack of clinicopathologic correlation in the diagnostic assessment of OLP. We therefore propose a set of revised diagnostic criteria of OLP and oral lichenoid lesions, based on the WHO definition of OLP, including clinical as well as histopathologic aspects.
Changing expression of E‐ and P‐cadherin during rat tongue carcinogenesis induced by 4‐nitroquinoline 1‐oxide
Authors: Sakaki Toshio , Tamura Isao , Kadota Hidetaka , Kakudo Kenji
Published: September 2003

Background:  Oral squamous cell carcinoma (SCC) develops from pre‐malignant lesions, but the role of cell adhesion molecules such as E‐cadherin (E‐CD) and P‐cadherin (P‐CD) in the pre‐malignant stage has not been elucidated.

Methods:  The expression of E‐CD and P‐CD was examined immunohistochemically and biochemically in a 4‐nitroquinoline 1‐oxide (4NQO)‐induced rat model of carcinogenesis.

Results:  The expression of E‐CD in the pre‐malignant stage was the same as that in the normal epithelium. The expression of P‐CD was even throughout the prickle cell layer in the dysplasia stage. E‐CD and P‐CD were expressed in essentially the same locations in SCC and in the pre‐malignant stage. P‐CD expression was very strong in the pre‐malignant stage, compared to that in normal epithelium.

Conclusions:  Aberrant P‐CD expression in E‐CD‐positive cells may play a crucial role in the progression of the pre‐malignant stage of 4NQO‐induced carcinogenesis, and may activate mechanisms responsible for cell proliferation.
Doxorubicin‐Induced Cardiac Mitochondrionopathy
Authors: Wallace Kendall B.
Published: September 2003

Abstract: Doxorubicin (Adriamycin®) is a potent and broad‐spectrum antineoplastic agent prescribed for the treatment of a variety of cancers, including both solid tumours and leukaemias. Unfortunately, despite its broad effectiveness, long‐term therapy with doxorubicin is associated with a high incidence of a cumulative and irreversible dilated cardiomyopathy. Numerous mechanisms have been proposed to account for this toxicity. Although there is general consensus that doxorubicin undergoes redox cycling to generate free radicals that are responsible for mediating the various cytopathologies associated with drug exposure, the source and subcellular targets continue to be debated. This short review provides a synopsis of the evidence implicating cardiac mitochondria as key intracellular targets, both as sites of generation of highly reactive free radical intermediates as well as targets for the interference with cell calcium regulation and bioenergetic failure that are hallmarks of doxorubicin‐induced cardiac failure.
Protective Effects of Glycyrrhizin on Gentamicin‐Induced Acute Renal Failure in Rats
Authors: Sohn Eun‐Jin , Kang Dae‐Gill , Lee Ho‐Sub
Published: September 2003

Abstract: The aim of this study was to investigate the effects of glycyrrhizin (200 mg/kg/day) on renal function in association with the regulation of aquaporin 2 water channel in rats with gentamicin (100 mg/kg/day)‐induced acute renal failure. Polyuria in rats with gentamicin‐induced acute renal failure was associated with down‐regulation of renal aquaporin 2 in the inner and outer renal medulla, and cortex. Glycyrrhizin administration restored the expression of aquaporin 2 with paralleled changes in urine output. Changes in renal functional parameters, such as creatinine clearance, urinary osmolality, and solute‐free reabsorption, accompanying acute renal failure were also partially restored after administration of glycyrrhizin. Histological changes in rats with gentamicin‐induced acute renal failure were also abrogated by glycyrrhizin treatment. The above results suggest that glycyrrhizin treatment could ameliorate renal defects in rats with acute renal failure induced by gentamicin.
Oxidation by Thimerosal Increases Calcium Levelsin Renal Tubular Cells
Authors: Jan Chung‐Ren , Jiann Bang‐Ping , Lu Yih‐Chau , Chang Hong‐Tai , Yu Chia‐Cheng , Chen Wei‐Chung , Huang Jong‐Khing
Published: September 2003

Abstract: The effect of thimerosal, a reactive oxidant, on cytoplasmic free Ca2+ concentrations ([Ca2+]i) in Madin Darby canine kidney (MDCK) cells was explored by using the Ca2+‐sensitive dye fura‐2. Thimerosal acted in a concentration‐dependent manner with an EC50 of 0.5 μM. The Ca2+ signal comprised a gradual rise and a sustained elevation. Removal of extracellular Ca2+ reduced 80% of the signal. In Ca2+‐free medium, the [Ca2+]i rise induced by 1 μM thapsigargin (an endoplasmic reticulum Ca2+ pump inhibitor) was completely inhibited by pretreatment with 5 μM thimerosal. The thimerosal (5 μM)‐induced Ca2+ release was not changed by inhibition of phospholipase C with 2 μM U73122. Collectively, this study shows that thimerosal induced [Ca2+]i rises in renal tubular cells via releasing store Ca2+ from the endoplasmic reticulum Ca2+ stores in a manner independent of phospholipase C activity.
Lovastatin Induces Relaxation and Inhibits L‐Type Ca2+ Current in the Rat Basilar Artery
Authors: Bergdahl Andreas , Persson Erik , Hellstrand Per , Swärd Karl
Published: September 2003

Abstract: Statins inhibit cholesterol biosynthesis and protect against ischaemic stroke. It has become increasingly apparent that the beneficial effects of statin therapy may extend beyond lowering of serum cholesterol. The present study was done to explore possible pleiotropic statin effects at the level of the cerebral vascular smooth muscle. Lovastatin, lovastatin acid, simvastatin and pravastatin, were added to segments of the rat basilar artery and effects on contraction and Ca2+ handling were examined. Pravastatin had no effect on contraction. Simvastatin, lovastatin, and, to a lesser degree, lovastatin acid, caused relaxation (IC50=0.8, 1.9 and 22 μmol/l) of both intact and denuded arteries precontracted with 5‐HT or high‐K+. This effect was not reversed by mevalonate, suggesting that it was not related to cholesterol or isoprenoid metabolism. Relaxation was associated with a reduction of the intracellular Ca2+ concentration measured with Fura 2 and with a reduced Mn2+ quench rate, suggesting a direct effect on ion channels in the smooth muscle cell membrane. Current measurements in isolated and voltage clamped basilar artery muscle cells demonstrated that both lovastatin and lovastatin acid inhibit L‐type Ca2+ current. We propose that lipophilicity is an important factor behind the effects of statins on vascular tone and that Ca2+ current inhibition is the likely mechanism of action.
Autoprotection against Acetaminophen Toxicity in Cultured Rat Hepatocytes: The Effect of Pretreatment and Growth Factors
Authors: Grunnet Niels , Tygstrup Niels , Dich John
Published: September 2003

Abstract: To evaluate the effect of acetaminophen pretreatment and growth factors on acetaminophen hepatotoxicity in cultured rat hepatocytes, rat hepatocytes in primary culture were exposed to acetaminophen 8 mM after pretreatment with either acetaminophen 1 mM, treatment with growth factors (EGF and HGF), or no treatment. Growth response was measured by changes in DNA, [3H]thymidine incorporation and mRNA of growth related proteins, cell damage by leakage of LDH to the medium and changes in ATP, and protection against toxicity by changes in glutathione, cytochrome P450 and the expression of glutathione‐S‐transferase and Cyp1A2. Pretreatment with acetaminophen induced growth response, weaker than that of growth factors, but pretreatment and growth factors reduced cell damage equally effectively. Glutathione and glutathione‐S‐transferase increased more by growth factors than by pretreatment, but both conditions reduced Cyp1A2 to near zero. Pretreatment and growth factors protect against acetaminophen toxicity by suppressing the expression of Cyp1A2, thereby reducing the production of the intermediate N‐acetyl‐p‐benzoquinone imine (NAPQI). Suppression of Cyp1A2 expression by pretreatment is assumed to be due to a growth‐stimulating effect of low concentrations of acetaminophen.
Carbon Monoxide Specifically Inhibits Cytochrome C Oxidase of Human Mitochondrial Respiratory Chain
Authors: Alonso Jose‐Ramon , Cardellach Francesc , López Sònia , Casademont Jordi , Miró Òscar
Published: September 2003

Abstract: Carbon monoxide (CO) toxicity is the result of a combination of tissue hypoxia and direct CO‐mediated damage at a cellular level, since not all the signs and symptoms presented can be explained only by the formation of carboxyhaemoglobin. Mitochondria, specially the electron transport chain, seem to be the target for CO at a subcellular level. However, the direct effect of CO in individual complexes of the human mitochondrial respiratory chain has not been completely elucidated. We here studied the in vitro effect of CO on individual complexes of the mitochondrial respiratory chain of human mitochondria. We obtained muscle tissue from 10 healthy people who underwent orthopaedic surgery for hip replacement. Isolated mitochondria were incubated for 5 min. under CO concentrations of 50, 100 and 500 ppm. Afterwards, enzymatic activities of individual complexes of the mitochondrial respiratory chain were assessed in vitro and compared with those obtained in basal (synthetic air without CO) conditions. Cytochrome c oxidase (complex IV of the mitochondrial respiratory chain) activity showed a decrease from 836±439 nmol/min./mg of mitochondrial protein after air incubation to 670±401, 483±182, and 379±131 nmol/min./mg after 50, 100 and 500 ppm of CO incubation, respectively (20%, 42% and 55% decrease in cytochrome c oxidase activity). This gradual decrease in cytochrome c oxidase was found to be statistically significant (P<0.001). Other complex activities showed no any significant variation. Carbon monoxide is toxic for mitochondria in man, altering the mitochondrial respiratory chain at the cytochrome c oxidase level. This inhibition in cytochrome c oxidase may play a role in the development of the symptoms observed in acute CO poisoning, and in some diseases related to smoking.
The Action of Oxybutynin on Haemodynamics and Metabolism in the Perfused Rat Liver
Authors: Comar Jurandir Fernando , Suzuki‐Kemmelmeier Fumie , Bracht Adelar
Published: September 2003

Abstract: The present study was planned to investigate the possible action of oxybutynin on liver haemodynamics and its influence on metabolic variables. The isolated liver perfused either bivascularly or monovascularly in the non‐recirculating system was used for the experiments and Krebs/Henseleit‐bicarbonate buffer (pH 7.4) as a perfusion fluid. Oxybutynin (25–200 μM) was infused, the infusion time for each concentration being 14 min. Portally infused oxybutynin increased the perfusion pressure starting at 100 μM. Oxygen uptake was diminished, also starting at 100 μM. Arterially infused oxybutynin also increased the perfusion pressure in the hepatic artery. Lactate and pyruvate releases were considerably diminished by oxybutynin. Glucose release showed a small initial stimulation, then returned to values slightly below the basal ones. Cessation of oxybutynin infusion resulted in progressive stimulation of glucose release. When Ca2+ was omitted all effects of oxybutynin vanished. The hepatic contents of glucose, glucose 6‐phosphate and lactate in the presence of 200 μM oxybutynin increased 7.8‐, 4.6‐ and 5.1 times, respectively. The pyruvate content was not changed. The ATP content was diminished by 26.6% in the presence of 200 μM oxybutynin, but the AMP content was increased by 64.3%. The ADP content was not changed. Apparently, upon administration of oxybutynin, a considerable fraction of the liver parenchyma ceased to be irrigated or almost so, which is apparent from the concomitant inhibition of oxygen uptake, pressure increase and inhibition of glucose, lactate and pyruvate release together with the simultaneous intracellular accumulation of glucose, lactate and glucose 6‐phosphate.