bluuebunny/crossref_metadata_2025 huggingface dataset:
Search for human herpesvirus 6, human cytomegalovirus and varicella zoster virus DNA in recurrent aphthous stomatitis tissue
Authors: Ghodratnama F. , Riggio M. P. , Wray D.
Published: April 2006

In the present study, the involvement of human herpesvirus 6 (HHV‐6). human cytomegalovirus (HCMV) and varicella zoster virus (VZV) in the aetiology of recurrent aphthous stomatitis (RAS) was investigated using the polymerase chain reaction (PCR). Biopsies from 21 RAS patients were analysed, and 20 oral lichen planus (OLP) and 13 normal biopsies were tested as controls. HHV‐6‐DNA was detected in six of the RAS samples whereas VZV‐DNA and HCMV‐DNA were not detected in any RAS samples. In the OLP samples, four biopsies were positive for HHV‐6‐DNA and two were positive for HCMV‐DNA. One sample from this group was positive for both HHV‐6‐DNA and HCMV‐DNA. VZV‐DNA was not found in any RAS or OLP biopsies. No viral DNA was present in any normal control biopsies. These results do not support an aetiological role for HCMV and VZV in RAS. although the possible involvement of HHV‐6 cannot be excluded.
Oral exfoliative cytology: review of methods of assessment
Authors: Ogden G. R. , Cowpe J. G. , Wight A. J.
Published: April 2006

The use of oral exfoliative cytology in clinical practice declined due to the subjective nature of its interpretation and because there may be only a small number of abnormal cells identifiable in a smear. The more recent application of quantitative techniques, together with advances in immunocytochemistry. have refined the potential role of cytology, stimulating a reappraisal of its value in the diagnosis of oral cancer. This review considers the influence of the quantitative analysis of cytomorphology. DNA, analysis and other tumour markers applied to oral exfoliative cytological samples. These studies indicate that oral cytology may provide an important adjunct in the assessment of the patient with a potentially cancerous oral lesion.
Enhancement of calcyclin gene RNA expression in squamous cell carcinoma of the oral mucosa, but not in benign lesions
Authors: Berta Giovanni N. , Ghezzo Franco , D'Avollo Antonio , Zulian Paolo , Carbone Vincenzo , Racca Silvia , Vercellino Vittrio , Di Carlo Francesco
Published: April 2006

Oral cancer is a neoplasm with some known causes. Proliferation genes are significant among its few pathogenetic and prognostic factors. Calcyclin is a cell‐cycle‐related gene, the function of which is still unclear. Its expression and that of Haras and histone‐H3 have been investigated in an assessment of their pathogenetic role in squamous cell carcinoma. RNA extracted from the pathological and normal mucosa of patients with squamous cell carcinoma (SCC) and benign lesions was reverse transcribed and amplified by the polymerase chain reaction (PCR). The expression of all three genes in the pathological mucosa was enhanced in SCC only. This suggests that they may be involved in its pathogenesis and provides another parameter for the differentiation of malignant and benign lesions.
The in vitro adhesion of Candida albicans to buccal epithelial cells (BEC) from diabetic and non‐diabetic individuals after in vivo and in vitro application of nystatin
Authors: Darwazeh A. M. G. , MacFarlane T. W. , Lamey P.‐J.
Published: April 2006

Buccal epithelial cells (BEC) from 12 patients with diabetes mellitus and 12 age‐and sex‐matched non‐diabetic subjects were tested in vitro for adhesion of Candida albicans following exposure to nystatin both in vitro and in vivo. Adhesion was significantly reduced (P < ss0.002) to cells from both the diabetic and non‐diabetic subjects after in vitro exposure to nystatin. but the reduction in adhesion was variable (5.0–50.7%) in control subjects and 0.5‐4–8.4% in diabetic subjects) and equivalent between the two groups. In vivo exposure to nystatin produced no overall significant reduction in Candida! adhesion to cells from either diabetic or control subjects.
Oral candidiasis in HIV infection: predictive value and comparison of findings in injecting drug users and homosexual men
Authors: Frisian Joan A. , Begg Melissa D. , Lamster Ira B. , Gorman Jack , Mitchell‐Lewis Dennis , Bucklan Ronnie D. , El‐Sadr Wafaa M.
Published: April 2006

The objectives of this study were to compare the relationship of oral candidiasis to HIV status, cohort and CD4+ lymphocyte values in injecting drug users and homosexual men and to examine its impact on prognosis. An oral examination was added to an ongoing longitudinal study of HIV infection. Data obtained at 6‐month intervals included smoking, illicit drug use. medication use. symptoms and medical diagnoses, physical examination findings and laboratory data. In this study HIV+ subjects were much more likely to present with oral candidiasis than were HIV‐ subjects (OR = 6.3. P < 0.0l), Injecting drug users, regardless of serostatus. were more likely than homosexual men to present with oral candidiasis I OR = 3.0. P=0.00l). In both cohorts oral candidiasis was associated with low CD4+ lymphocyte counts and percent ages, and Kaplan‐Meier survival estimates showed that subjects with oral candidiasis had a poorer prognosis than those without candidiasis, even after controlling for CD4+ lymphocyte count.
Immunocytochemical detection of autoantibody deposits in Tzanck smears from patients with oral pemphigus
Authors: Mignogna M. D. , Lo Muzio L. , Zeppa P. , Ruocco V. , Bucci E.
Published: April 2006

Eighteen patients, ten affected by pemphigus vulgaris and four affected by herpes simplex of the oral mucosa. together with four healthy patients as controls, were investigated by cytologic examination of Papanicolaou stained smears obtained by scraping the oral mucosa. In all cases additional smears were immunostained with the alkaline phosphatase‐anti‐alkaline phosphatase (APAAP) technique using monoclonal antibodies against human heavy IgG chains and A light chains. The results have shown that, for a cytological diagnosis of pemphigus, this technique can be used as an easy substitute for the immunofluorescence test and does not require any specialized training or equipment. The findings are clearly detectable by light microscopy and allow, together with the immunostaining. an adequate visualization of cell morphology.
An immunohistochemical study of thrombomodulin in oral squamous cell carcinoma and its association with invasive and metastatic potential
Authors: Tabata Masashi , Sugihara Kazumasa , Yonezawa Suguru , Yamashita Sukehide , Maruyama Luro
Published: April 2006

Thrombomodulin (TM) is a glycoprotein that was originally identified on vascular endothelium and characterized as a natural endothelial anticoagulant. We reported previously that TM was also expressed at cell‐cell boundaries of squamous epithelium, except in the basal layer cells and upper granular layer cells. The expression pattern of TM in the squamous cells implies that this molecule might be associated with keratinocyte differentiation, as well as being a potent anticoagulant. In the present study we examined TM expression immunohistochemically in biopsy specimens from 65 patients with primary oral squamous cell carcinoma (OSCC). and compared the results with the biological behavior of the carcinomas. The patients with intense TM expression in the carcinoma showed a significantly lower frequency of lymph node metastasis and significantly more favorable survival than those with negative TM expression. The TM expression was a better marker than the other prognostic factors, such as differentiation degree, tumor size and invasion mode. When TM expression was compared between the primary and metastatic lesions in the 36 patients who had lymph node metastasis, 14 (39%) showed decreased TM expression. 19 (53%) showed no change, and 3 (8%) showed an increase in the metastatic lesions. Wilcoxon's signed‐rank test indicated that tumor cells positive for TM expression were significantly rarer in the metastatic lesions than in the primary tumors (P<0.05). These results indicate that reduced expression of TM is associated with metastasis of carcinoma cells. The reduction of TM expression seems to play an important role in the metastatic process of OSCC, and to be related with a poor outcome for the patients.
Immunohistochemical demonstration of bone morphogenetic protein in odontogenic tumors
Authors: Gao Y. H. , Yang L. J. , Yamaguchi A.
Published: April 2006

The aim of the present study was to describe the expression and distribution of bone morphogenetic protein (BMP) in odontogenic tumors by immunohistochemistry using monoclonal antibody against bovine BMP (BMPMcAb). Eight types of odontogenic tumors (44 cases), including ameloblastoma (20 cases), cementifying fibroma (8 cases), benign cementoblastoma (5 cases), dentinoma (3 cases), compound odontoma (2 cases), adenomatoid odontogenic tumor (2 cases), calcifying epithelial odontogenic tumor (2 cases) and odontogenic fibroma (2 cases), were studied. The results showed that, according to the immunostaining pattern of BMPMcAb, tumors could be classified into two types: all cementifying fibro‐mas, benign cementoblastomas. Dentinomas, odontogenic fibromas. and compound odontomas demonstrated a positive reaction, whereas all ameloblastomas, adenomatoid odontogenic tumors, and calcifying epithelial odontogenic tumors were negative. BMPMcAb‐positive odontogenic tumors were those tumors with formation of enamel, dentin, cementum or bone. Therefore. BMP might play an important role in the formation of calcified dental tissues and the development of odontogenic tumors contaning such tissues.
Comparison between submucosal (extra‐nodal) and nodal non‐Hodgkin's lymphoma (ahl) In The oral and maxillofacial region
Authors: Shindoh M. , Takami T. , Arisue M. , Yamashita T. , Saito T. , Kohgo T. , Notani K. , Totsuka Y. , Amemiya A.
Published: April 2006

Fifty‐two cases of non‐Hodgkin's lymphoma (ahl) In The oral and maxillofacial region, comprising 31 submucosal (extra‐nodal) and 21 cervical node Nhls, Were investigated. The patients' ages ranged from 5 to 86 years, with a bimodal age distribution among young people below 12 years of age (average 8 years) and in those aged 30 years or older (average 60.3 years). The male‐to‐female gender difference ratio was 1.3:1. Patients presented with swelling as the major symptom. Histologically. diffuse, large cell malignant lymphoma was the most frequent type and 67.9″.!’of lymphomas were of intermediate malignancy as defined by the Working Formulation for Clinical Usage. All submucosal lymphomas showed diffuse proliferation patterns, although follicular proliferation was identified in 5 of the 21 nodal lymphomas. Immunohislochemistry showed that the B‐cell type was predominant, especially in nodal lymphomas.
Localised oral histoplasmosis lesions associated with HIV infection
Authors: Warnakulasuriya K. A. A. S. , Harrison J. D. , Johnson N. W. , Edwards S. , Taylor C. , Pozniak A. L.
Published: April 2006

Opportunistic fungal infections account for a significant amount of morbidity associated with HIV disease. We report here a case of localised oral histoplasmosis without evidence of disseminated disease in a patient who lacked stigmata of HIV disease at the time of initial presentation. The diagnosis is based on histology with special stains, complement fixing antibodies in serum, and culture of the organism from fresh tissues. Activation of subclinical disease following an infection in Uganda may explain the development of these exophytic oral lesions in this British resident.
Periapical tissue responses to dentin and vitreous carbon plugs in apical perforations of dogs' teeth
Authors: Torabinejad Mahmoud , Owen Rodney , Danforth Robert A. , Howell Robin E.
Published: April 2006

Abstract Apical perforations were made in 25 roots of mandibular premolars and maxillary incisors of 2 adult Labrador dogs. Autogenic dentin chips or vitreous carbon powder were condensed to form a 2 mm apical plug in each of 16 canals. The coronal segments of the canals were filled with gutta percha and Grossman root canal sealer by the lateral condensation technique. Using the same obturation technique, the remaining 9 canals were HI led with gutta percha and Grossman root canal sealer 2 mm short of the radiographic apices with no apical plugs. Apical bridge formation and periapical inflammation were compared in 3 groups.
Long‐term calcium hydroxide treatment of a tooth with iatrogenic root perforation and lateral periodontitis
Authors: Trope Martin , Tronstad Leif
Published: April 2006

Abstract This case report describes the treatment of a lower right canine with a periapical radiolucency and a radiolucency associated with a lateral perforation that was made 10 years previously, during an apicoectomy procedure on the adjacent lateral incisor. Long‐term calcium hydroxide treatment was carried out. After 3 months the apical radiolucency was greatly reduced and after 1 year was completely resolved. After 3 years a hard tissue barrier had formed across the lateral perforation defect, but at no time during the treatment period did the inflammatory lesion adjacent to the perforation improve. It is suggested that epithelial downgrowth and possibly periodontal pocket formation had occurred, allowing irritants from the gingival sulcus to sustain the inflammatory reaction in the perforation area.
Endodontic treatment decisions: A study of the clinical decision‐making process
Authors: Reit Claes , Grondahl Hans‐Göran , Engström Bure
Published: April 2006

Abstract From general decision‐making theory and endodontic teaching paradigms a hypothesis was evolved explaining variations in treatment decisions with variations in subjective probabilities of disease and complications. This hypothesis was tested on 20 general practitioners and 7 endodontists, who were introduced to 10 cases with endodontically‐treated teeth showing periapical radiolucencies of various proportions. For each case the examiners were instructed to assess probability of disease, probability of future complications and to determine mode of treatment. The results indicate that interindividual variations in endodontic treatment decisions are influenced to a rather low degree by subjective probabilities of different diagnoses and of expected complications. Instead, the decision makers seemed to rely on a limited number of heuristic principles which reduced the complex task of assessing probabilities and predicting outcomes to simpler judgemental operations.
Effect of electric current and silver electrodes on oral bacteria
Authors: Tronstad Leif , Trope Martin , Hammond Benjamin F.
Published: April 2006

Abstract The effect of a weak direct current and silver ions on microorganisms commonly found in the root canal was studied. Pour plates with the various microorganisms were prepared in petri dishes and 2 identical silver wire electrodes were submerged in the agar. The plates were incubated at 37°C for 24 hours with the electrodes attached lo the positive and negative poles of constant current generators set to deliver currents of 0.2, 0.4, 0.8, 1.5 and 10.0 μamp. Zones of inhibition were evident at the positive electrode in all experiments. The widest zones were found at 1.5 μamp followed by 0.8 and 10.0 μamp. Statistically, the responses at these current levels could not be differentiated, but they were different from the results obtained at 0.2 and 0.4 μamp.
Bacteriologic status of the root canal after sonic, ultrasonic and hand instrumentation
Authors: Barnett Frederic , Trope Martin , Khoja Mohamad , Tronstad Leif
Published: April 2006

Abstract The purpose of this study was to assess the bacteriologic status of the root canal after sonic, ultrasonic and hand instrumentation. Root canal infection was induced in 50 single‐rooted teeth in young dogs by removing the pulp and filling the canals with dental plaque. After 7 clays the root canals were instrumented under aseptic conditions with conventional hand instruments, a sonic vibratory device or an ultrasonic device. Sterile saline or 2.5% sodium hypochlorite was used as irrigating solution. Following instrumentation a sterile paper point was sealed into the root canals. After 7 d the root canals were reopened under aseptic conditions and the paper points were incubated for the demonstration of bacteria, using pre‐reduced thioglycolate culture medium and anaerobic chambers. The results obtained with the different instrumentation techniques and irrigating solutions were compared by means of the Chi‐square test. The results indicated that the sonic and ultrasonic devices were not more effective in the elimination of bacteria from the root canal than conventional hand instrumentation. Irrigation with sodium hypochlorite appeared to be more effective than saline in producing bacteria‐free root canals; however, this difference was not statistically significant. Thus, it appeared that more than one appointment and the supporting action of an antibacterial medicament between appointments would be necessary to achieve bacteria‐free root canals in infected teeth in a predictable manner.
Strengthening and restoration of immature teeth with an acid‐etch resin technique
Authors: Rabie G. , Trope M. , Garcia C. , Tronstad L.
Published: April 2006

Abstract Endodontic treatment with subsequent restoration of 3 immature incisors with horizontal fractures in the cervical region is described. In 1 tooth the fracture occurred supragingivally, whereas in 2 others the fracture was such that the root margins were between 1 and 2 mm subosseous. In these teeth proper access to the roots was established by means of orthodontic extrusion and/or periodontal surgery. After endodontic treatment, the gutta‐percha was removed from the root canals to a level 2 to 3 mm apically to the osseous crest. The root canal dentin was acid‐etched and a post to retain a crown was cemented into the canal with a composite resin. The resin will then penetrate into the dentinal tubules of the root canal walls and strengthen the root to such a degree that it becomes restorable. Semipermanent composite resin crowns and, in one instance, a more permanent porcelain crown were used to restore the teeth.
Diagnosis of luxation injuries: The importance of standardized clinical, radiographic and photographic techniques in clinical investigations
Authors: Andreasen Frances M. , Andreasen Jens O.
Published: April 2006

Abstract The records of 400 patients treated for luxation injuries of the permanent dentition from 1965 to 1980 at the Dental Department of University Hospital, Copenhagen, were studied with respect to the development of post‐traumatic complications. Data from the time of injury were collected on a standardized questionnaire and completed by the treating oral surgeon as lie interviewed the patient. Standardized forms for follow‐up clinical data were also used. The present investigation was aimed at comparing the quality of information collected from the time of injury on a standaradized questionnaire vs. from a non‐standardized form. The precision of radiographic techniques with or without film holders was also studied, as well as the value of photographic documentation of luxations vs. radiographs alone. Moreover, the number of radiographs needed to diagnose displacement was checked. It was found that when a standardized questionnaire was not used for collection of data, concerning the injury, an average of 53.3% of the information on the standardized questionnaire was recorded. It was also found that the variation of tooth length from one radiographic examination to the next was more than 3 times greater when film holders were not used than when they were (6.9% average error in measurement vs. 2.0%, respectively). Moreover, an occlusal radiograph was found to be the best exposure for disclosing extrusions and lateral luxations, while occlusal and periapical exposures were equally good for disclosing intrusions. A combination of an occlusal radiograph plus an eccentric (i.e. mesio‐ or distoradial) periapical radiograph could disclose almost all displacements. It was also found that photographic registration was necessary to precisely diagnose luxation type retrospectively, as radiographs were often misleading in indicating the direction and extent of displacement. It is concluded that standardized techniques (e.g. questionnaires and radiographic film holders) are necessary to provide reliable information in clinical investigations and that photographic registration adds important information about I lie‐extent and direction of displacement, a factor to be considered in retrospective studies.
The antibacterial effect of camphorated paramonochlorophenol, camphorated phenol and calcium hydroxide in the treatment of infected root canals
Authors: Byström Anders , Claesson Rolf , Sundqvist Göran
Published: April 2006

Abstract The bactericidal efficacy of calcium hydroxide, camphorated phenol and camphorated paramonochlorophenol as intracanal dressings was evaluated clinically when the root canals of 65 single‐rooted teeth with periapical lesions were treated. A bacteriological technique that could detect even small numbers of anaerobic bacteria in the canals was used. After treatment, including intracanal dressing with calcium hydroxide paste (Calasept), bacteria were recovered from one of 35 treated root canals. After use of camphorated phenol or camphorated paramonochlorophenol as the dressing, bacteria were recovered from 10 of 30 treated root canals. The isolated bacteria were predominantly Gram‐positive and anaerobic. There was no indication that specific bacteria were resistant to the treatment. The results indicate that the endodontic treatment of infected root canals can be completed in two appointments when calcium hydroxide paste is used as an intracanal dressing.
Histometric evaluation of odontoblast responses to Nobetec® and Super Syntrex®
Authors: Benjamin Neville , Cleaton‐Jones Peter , Leidal T. Ingar
Published: April 2006

Abstract A reproducible method to determine reduction in odontoblast number and variation in dentine thickness was devised. Using this method the pulp reaction patterns to Nobetec® (a modified zinc oxide‐eugenol cement) and Super Syntrex® (a silicate cement) in verve I monkeys were quantitated. This investigation showed that statistically significant reductions in odontoblast numbers were seen under cut dentinal tubules compared lo areas under a cavity with no cut tubules. Reparative dentine thickness was similar under both materials and the mean thickness doubled between 28 and 56 clays after cavity preparation. Both materials were (bund lo be irritant. It is suggested that quantitation of odontoblasts and reparative dentine thickness under cut dentinal tubules may be used as (he main criteria in pulpal studies in order to discriminate between test materials.
Osteogenic response to low electric current and silver electrodes
Authors: Tronstad Leif , Trope Martin , Saint‐Pierre Francoise , Elfenbein Leslie , Black Jonathan , Brighton Carl T.
Published: April 2006

Abstract It has been shown that weak anodic currents are bactericidal when delivered by silver electrodes. In this study, the Osteogenic effect of weak cathodic currents and silver electrodes was studied in 20 adult rabbits. A 12 mm silver wire electrode with diameter 0.2 mm was inserted into the medullary canal of the left tibia and connected to the negative pole of constant current generators implanted subcutaneously in the backs of the animals. The generators were set to deliver 1.5 and 10 μA. For comparison, a 12 mm silver wire was inserted into the medullary canal of the right tibia. This wire was not connected to the power pack. After 21 days the animals were sacrificed and I In‐lower limbs fixed with 10% neutral buffered formalin via aortic perfusion. The tibiae with the electrodes in place were excised and X‐rayed to document the location of the electrode and 2.5 mm‐thick transverse slices were cut from this part of the tibiae. They were demineralized, embedded in paraffin, sectioned at 6 μm, and stained with hematoxylin and eosin. The sections were examined for bone growth in the medullary canals using a Zeiss Universal microscope and a MOP‐3 computerized area integrator. Bone growth was recorded as percentage of the total cross medullary canal area. New bone was observed at the experimental sites as well as in some of the controls. The largest amount of bone had formed in the experiments with a current level of 10 μA.
Differences in apex formation during apexification with calcium hydroxide paste
Authors: Feiglin Barry
Published: April 2006

Abstract In immature teeth, apexification once only produced occassionally ‐ can now be induced in most cases by the use of calcium hydroxide paste. The different types of apices produced are presented in this paper and warning is given as to the young, very immature tooth where apexification may occur, but will leave the tooth with a very poor prognosis.
Tooth avulsion and replantation — A review
Authors: Hammarström Lars , Pierce Angela , Blomlöf Leif , Feiglin Barry , Lindskog Sven
Published: April 2006

Abstract The major causes of post‐replantation tooth loss are inflammatory root resorption and root resorption associated with ankylosis. Recent studies have concentrated on delineating the cellular interactions in the pulp and periodontium in order to more fully understand the various factors affecting the prognoses of such teeth. The aim of this report is to discuss the nature of the pathology responsible for tooth loss following avulsion and to review recent replantation and attachment studies.
Transient apical breakdown and its relation to color and sensibility changes after luxation injuries to teeth
Authors: Andreasen Frances M.
Published: April 2006

Abstract In examining a population of 637 luxated permanent teeth, it was found that 27 teeth (4.2%) demonstrated apical breakdown in the form of either a pronounced radiolucency which appeared spontaneously some time after injury, or a persistent expansion of the periodontal ligament space (PDL) over an extended interval after injury, which at later follow‐up controls had either returned to normal without further radiographic change or was accompanied by surface resorption and/or pulp canal obliteration without intervening treatment. Two of the 27 teeth demonstrated radiographic change alone, while the remaining 25 demonstrated color and/or electrometric sensibility‐changes as well. Twenty‐three teeth had fully‐formed roots whose apices were either closed or half‐closed at the time of injury. Five had roots which were fully formed, but with an open apex; the remaining tooth had three‐quarter root formation. The injuries were moderate, the majority being extrusion or lateral luxation, affecting both pulpal and periodontal structures. Based on clinical findings, the following hypothesis is proposed: Transient apical breakdown appears to be a phenomenon linked to the repair processes in the traumatized pulp or pulp and periodontium of luxated mature teeth which returns to normal when repair is complete. Whether this is related to a transitory infection and/ or removal of necrotic traumatized tissue cannot be evaluated from the material available.
Resistance to fracture of restored endodontically treated premolars
Authors: Trope Martin , Langer Ian , Maltz David , Tronstad Leif
Published: April 2006

Abstract Endodontically treated premolars were restored using 5 different methods. Copper rings were filled with commercial hard‐setting cement and the teeth were placed into the cement up to the level of the cemento‐enamel junction. The teeth were grouped according to restorative method, mounted in an Instron TT machine and the buccal walls subjected to a slowly increasing compressive force until fracture occurred. The force of fracture of the walls of each tooth was recorded and the results in the various groups compared. All teeth fractured in a similar manner irrespective of the restorative method used. The resistance to fracture of the teeth increased significantly when MOD cavities in the teeth were acid etched prior to the restoration with a composite resin. The use of a bonding agent after acid etching did not further increase the resistance to fracture of the premolars restored with a resin. The acid etch composite resin technique was as effective in preventing fractures of the teeth when 2 mm of the resin was removed and replaced with an amalgam as when the entire cavities were filled with the resin material.
A scanning electron microscope study of dentinal tubule continuity in monkey tooth sections
Authors: Kroon Jeroen , Grossman Elly Saskia , Cleaton‐Jones Peter
Published: April 2006

Abstract The American Dental Association (ADA) and Federation Dentaire Internationale (FDI) specifications for the biological evaluation of dental materials in experimental Cavities in dentine require that sections permit dentinal tubules to be followed from cavity floor to pulp lumen. The aim of this study was to investigate this requirement in the specification. Twenty hematoxylin and eosin stained sections of vervet monkey incisor teeth satisfying the ADA and FDI specifications were selected. Adjacent unstained sections of the same specimens were prepared for scanning electron microscopy, and a low power photomicrograph was taken of the dentine between the cavity floor and pulp for each specimen. Two areas on each photomicrograph were selected using a superimposed grid and random number table and this area was re‐photographed at higher magnification on the specimen. A histometric analysis of the 40 SEM photomicrographs thus prepared showed that the dentinal tubules in 14 specimens were cut in cross‐section, 14 were tangential and only 12 were longitudinal sections. None of die tubules examined in the high power photomicrographs was continuous. It is concluded that serial section evaluation of the area encompassing die entire cavity as well as a few sections before and beyond the cavity zone should be considered for inclusion in die specifications.
The measurement of human pain
Authors: McGrath Patricia A.
Published: April 2006

Abstract The assessment of human pain is complicated not only because pain, like other sensory experiences, is subjective, but also because pain, unlike other sensory experiences, may be modified by psychological, social, and situational factors. These factors can modify the neuronal response evoked by a relatively constant noxious stimulus (such as an injection) so that the resulting pain sensation may be enhanced or reduced. Consequently, in order to measure pain accurately, investigators must attempt to assess the subjective experience of pain.

Although there are observational, self‐report, behavioral, and physiological methods available for measuring pain, direct scaling techniques may constitute a comprehensive measure by providing qualitative and quantitative estimates of pain expressed in terms of a patient's perception. A patient may rate both the strength and the affective dimensions of their clinical pain using simple measurement techniques that have been validated in well‐controlled studies on experimental pain. Direct scaling throughout a range of stimulus intensities (experimental pain) or throughout a range of time intervals (clinical pain) also provides a framework for standardization of individual responses. This standardization facilitates rigorous evaluation of analgesic efficacy for different pharmacological methods and for different pain conditions.

The requirements for an objective measure of pain are similar to the requirements for any measuring instrument. These are: 1) reliability – that the procedure yields consistent results over time; 2) validity – that the procedure measures unequivocally a specific dimension of pain; 3) minimum inherent bias – that the procedure is relatively independent of method bias or patient/investigator response bias; and 4) versatility – that the procedure is applicable for both laboratory and clinical use and is practical for a wide variety of different medical settings.

Visual analog scales, a direct scaling method in which a patient adjusts the length of a line so that the length is proportional to their pain, have been validated in a variety of experimental and clinical pain studies. Although these scales are deceptively simple, they have the reliability, validity, and versatility necessary for an objective pain measure.
Thermal stimuli in dentinal sensitivity
Authors: Kim Syngcuk
Published: April 2006

Abstract Current thinking on thermal stimuli and dentinal sensitivity are reviewed in this manuscript. There are two schools of thought: 1) following the Hydrodynamic Theory, thermal stimuli evoke dentinal sensitivity by changing physical properties of the dentin, namely, tubular radius and dentinal fluid viscosity, and 2) thermal stimuli evoke dentinal stimuli by altering physiological properties of the pulp, namely, pulpal microcirculation, which in turn causes excitation of pulpal sensory nerves by an increased tissue pressure.
Delivery systems and clinical significance of available agents for dentinal hypersensitivity
Authors: Ciancio Sebastian G.
Published: April 2006

Abstract This paper evaluates the use and clinical significance of various chemotherapeutic agents and delivery systems for dentinal hypersensitivity. Agents applied by the dentist as well as those applied by the patient are included. The most effective topical agents have been: strontium chloride, potassium nitrate, sodium citrate. Iontophoresis offers promise for the treatment of sensitive surfaces which do not respond to topically applied agents.
Clinical evaluation of dentinal hypersensitivity: A comparison of methods
Authors: Kanapka Joseph A. , Colucci Salvatore V.
Published: April 2006

Abstract Clinical methods to quantitatively assess the effectiveness of treatments for dentinal hypersensitivity are based on two different principles: scalar rating of the intensity of pain perceived by a subject in response lo a constant stimulus, and measurement in physical parameters of the quantity of stimulus applied to achieve a constant endpoint response. Traditional scalar rating methods often lead to large placebo effects and are generally inaccurate and difficult to reproduce across laboratories because of the large number of variables involved in pain perception. To overcome this difficulty, a variable stimulus‐fixed end‐point response method was developed based on the controlled application of an electrical stimulus to the crowns of teeth with the endpoint being a sensation defined as warmth or tingling. The electrical stimulus procedure correlates highly with the traditional methods of cold air application and individual subjective evaluation. Advantages include pain avoidance, high precision and clinical practicality.
Recommendations for evaluating agents for the reduction of dentinal hypersensitivity
Authors:   ADA Ad hoc Advisory Committee
Published: April 2006

*The following committee members were nominated by the Council on Dental Therapeutics and appointed by President Bentley: Dr. Major M. Ash, Jr., Professor and Chairman, Department of Occlusion, School of Dentistry, University of Michigan; Dr. Mohandas Bhat, Assistant Professor, Department of Community Dentistry, Case Western Reserve University; Dr. Nabil Bissada, Professor and Chairman, Department of Periodontics, School of Dentistry, Case Western Reserve University; Dr. Sebastian G. Ciancio, Professor and Chairman, Department of Periodontics, School of Dentistry, State University of New York at Buffalo; Dr. Louis P. Gangarosa, Professor and Coordinator of Pharmacology, School of Dentistry, Medical College of Georgia; Dr. Hans Graf, Chairman, Department of Periodontology, School of Dentistry, University of Bern (Switzerland); Dr. Isreal Klineberg, Chairman, Department of Oral Biology and Pathology, School of Dentistry, State University of New York at Stony Brook; Dr. Joseph A. Kanapka, Assistant Director, Dental Research, Vicks Research Center; Dr. Synguck Kim, Assistant Professor, Department of Endodontics, College of Dental and Oral Surgery, Colombia University; Dr. Walter T. McFall, Jr., Professor, Department of Periodontology, School of Dentistry, University of North Carolina; Dr. Patricia A. McGrath, Director, Pain Research Unit, Department of Oral Biology, Faculty of Dentistry, University of Western Ontario; Dr. David A. Pashley, Professor, Department of Oral Biology‐Physiology, School of Dentistry, Medical College of Georgia; Dr. Gerald Silverman, Private Practice, Hartford, Connecticut.

Chairing the committee meeting were the following American Dental Association Staff Members: Dr. Kenneth H. Burrell, Assistant Secretary, Council on Dental Therapeutics; Dr. Conrad A. Naleway, Director, Division of Chemistry, Council on Dental Therapeutics; Dr. Helmut Zander, Special Consultant for Scientific Affairs, American Dental Association.

The committee was funded by the American Fund for Dental Health through the support of the Block Drug Company, the John O. Butler Company, the Mentholaltim Company, and Richardson‐Vicks, Inc.
Modulation of glucocorticoid receptor‐interacting protein 1 (GRIP1) transactivation and co‐activation activities through its C‐terminal repression and self‐association domains
Authors: Liu Pei‐Yao , Hsieh Tsai‐Yuan , Chou Wei‐Yuan , Huang Shih‐Ming
Published: April 2006

Glucocorticoid receptor‐interacting protein 1 (GRIP1), a p160 family nuclear receptor co‐activator, possesses at least two autonomous activation domains (AD1 and AD2) in the C‐terminal region. AD1 activity appears to be mediated by CBP/p300, whereas AD2 activity is apparently mediated through co‐activator‐associated arginine methyltransferase 1 (CARM1). The mechanisms responsible for regulating the activities of AD1 and AD2 are not well understood. We provide evidence that the GRIP1 C‐terminal region may be involved in regulating its own transactivation and nuclear receptor co‐activation activities through primary self‐association and a repression domain. We also compared the effects of the GRIP1 C terminus with those of other factors that functionally interact with the GRIP1 C terminus, such as CARM1. Based on our results, we propose a regulatory mechanism involving conformational changes to GRIP1 mediated through its intramolecular and intermolecular interactions, and through modulation of the effects of co‐repressors on its repression domains. These are the first results to indicate that the structural components of GRIP1, especially those of the C terminus, might functionally modulate its putative transactivation activities and nuclear receptor co‐activator functions.
Differing molecular mechanisms appear to underlie early toxicity of prefibrillar HypF‐N aggregates to different cell types
Authors: Cecchi Cristina , Pensalfini Anna , Baglioni Serena , Fiorillo Claudia , Caporale Roberto , Formigli Lucia , Liguri Gianfranco , Stefani Massimo
Published: April 2006

Considerable attention has been paid to the high cytotoxic potential of small, prefibrillar aggregates of proteins/peptides, either associated or not associated with amyloid diseases. Recently, we reported that different cell types are variously affected by early aggregates of the N‐terminal domain of the prokaryotic hydrogenase maturation factor HypF (HypF‐N), a protein not involved in any disease. In this study, we provide detailed information on a chain of events triggered in Hend murine endothelial cells and IMR90 fibroblasts, which have previously been shown to be highly vulnerable or very resistant, respectively, to HypF‐N aggregates. Initially, both cell lines displayed impaired viability upon exposure to HypF‐N toxic aggregates; however, at longer exposure times, IMR90 cells recovered completely, whereas Hend cells did not. In particular, significant initial mitochondrial permeability transition (MPT) pore opening was found in IMR90 cells followed by a sudden repair of membrane integrity with rapid and efficient inhibition of cytochrome c and AIF release, and upregulation of Bcl‐2. The greater resistance of IMR90 fibroblasts may also be due to a higher cholesterol content in the plasma membrane, which disfavours interaction with the aggregates. In contrast, Hend cells, which have less membrane cholesterol, showed delayed MPT opening with prolonged translocation of cytochrome c into the cytosol. Finally, the caspase 9 active fragment was increased significantly in both Hend and IMR90 cells; however, only Hend cells showed caspase 8 and caspase 3 activation with DNA fragmentation. From our data, the different responses of the two cell types to the same aggregates appear to be associated with two key events: (a) aggregate interaction with the plasma membrane, disfavoured by a high level of membrane cholesterol; and (b) alterations in mitochondrial functionality, leading to the release of pro‐apoptotic stimuli, which are counteracted by upregulation of Bcl‐2.
Electron‐transfer capacity of catechin derivatives and influence on the cell cycle and apoptosis in HT29 cells
Authors: Lozano Carles , Juliá Lluís , Jiménez Aurora , Touriño Sonia , Centelles Josep J. , Cascante Marta , Torres Josep Lluís
Published: April 2006

Galloylated and nongalloylated catechin conjugates with cysteine derivatives have been synthesized and evaluated for their capacity to scavenge free radicals and to influence crucial functions (cell cycle, apoptosis) in HT29 colon carcinoma cells. We show that the nonphenolic part of the molecule modified the capacity of catechins to donate hydrogen atoms and to transfer electrons to free radicals. Nongalloylated derivatives did not significantly influence either the cell cycle or apoptosis. Among the galloylated species, 4β‐[S‐(O‐ethyl‐cysteinyl)]epicatechin 3‐O‐gallate, which showed a high electron‐transfer capacity (5 e– per molecule), arrested the cell cycle and induced apoptosis as expected for galloylated catechins such as tea (–)‐epigallocatechin 3‐O‐gallate. 4β‐[S‐(N‐Acetyl‐O‐methyl‐cysteinyl)]epicatechin 3‐O‐gallate, which showed the highest hydrogen‐donating capacity (10 H per molecule) while keeping the electron‐transfer capacity low (2.9 e– per molecule), did not trigger any significant apoptosis. The gallate moiety did not appear to be sufficient for the pro‐apoptotic effect of the catechin derivatives in HT29 cells. Instead, a high electron‐transfer capacity is more likely to be behind this effect. The use of stable radicals sensitive exclusively to electron transfer may help to design molecules with either preventive scavenging action (high hydrogen donation, low electron transfer) or therapeutic pro‐apoptotic activity (high electron transfer).
The subcellular localization of vaccinia‐related kinase‐2 (VRK2) isoforms determines their different effect on p53 stability in tumour cell lines
Authors: Blanco Sandra , Klimcakova Lucia , Vega Francisco M. , Lazo Pedro A.
Published: April 2006

VRK is a new kinase family of unknown function. Endogenous human vacinia‐related kinase 2 (VRK2) protein is present in both the nucleus and the cytosol, which is a consequence of alternative splicing of two VRK2 messages coding for proteins of 508 and 397 amino acids, respectively. VRK2A has a C‐terminal hydrophobic region that anchors the protein to membranes in the endoplasmic reticulum (ER) and mitochondria, and it colocalizes with calreticulin, calnexin and mitotracker; whereas VRK2B is detected in both the cytoplasm and the nucleus. VRK2A is expressed in all cell types, whereas VRK2B is expressed in cell lines in which VRK1 is cytoplasmic. Both VRK2 isoforms have an identical catalytic N‐terminal domain and phosphorylate p53 in vitro uniquely in Thr18. Phosphorylation of the p53 protein in response to cellular stresses results in its stabilization by modulating its binding to other proteins. However, p53 phosphorylation also occurs in the absence of stress. Only overexpression of the nuclear VRK2B isoform induces p53 stabilization by post‐translational modification, largely due to Thr18 phosphorylation. VRK2B may play a role in controlling the binding specificity of the N‐terminal transactivation domain of p53. Indeed, the p53 phosphorylated by VRK2B shows a reduction in ubiquitination by Mdm2 and an increase in acetylation by p300. Endogenous p53 is also phosphorylated in Thr18 by VRK2B, promoting its stabilization and transcriptional activation in A549 cells. The relative phosphorylation of Thr18 by VRK2B is similar in magnitude to that induced by taxol, which might use a different signalling pathway. In this context, VRK2B kinase might functionally replace nuclear VRK1. Therefore, these kinases might be components of a new signalling pathway that is likely to play a role in normal cell proliferation.
Physical properties and surface activity of surfactant‐like membranes containing the cationic and hydrophobic peptide KL4
Authors: Sáenz Alejandra , Cañadas Olga , Bagatolli Luís A. , Johnson Mark E. , Casals Cristina
Published: April 2006

Surfactant‐like membranes containing the 21‐residue peptide KLLLLKLLLLKLLLLKLLLLK (KL4), have been clinically tested as a therapeutic agent for respiratory distress syndrome in premature infants. The aims of this study were to investigate the interactions between the KL4 peptide and lipid bilayers, and the role of both the lipid composition and KL4 structure on the surface adsorption activity of KL4‐containing membranes. We used bilayers of three‐component systems [1,2‐dipalmitoyl‐phosphatidylcholine/1‐palmitoyl‐2‐oleoyl‐phosphatidylglycerol/palmitic acid (DPPC/POPG/PA) and DPPC/1‐palmitoyl‐2‐oleoyl‐phosphatidylcholine (POPC)/PA] and binary lipid mixtures of DPPC/POPG and DPPC/PA to examine the specific interaction of KL4 with POPG and PA. We found that, at low peptide concentrations, KL4 adopted a predominantly α‐helical secondary structure in POPG‐ or POPC‐containing membranes, and a β‐sheet structure in DPPC/PA vesicles. As the concentration of the peptide increased, KL4 interconverted to a β‐sheet structure in DPPC/POPG/PA or DPPC/POPC/PA vesicles. Ca2+ favored α⇆β interconversion. This conformational flexibility of KL4 did not influence the surface adsorption activity of KL4‐containing vesicles. KL4 showed a concentration‐dependent ordering effect on POPG‐ and POPC‐containing membranes, which could be linked to its surface activity. In addition, we found that the physical state of the membrane had a critical role in the surface adsorption process. Our results indicate that the most rapid surface adsorption takes place with vesicles showing well‐defined solid/fluid phase co‐existence at temperatures below their gel to fluid phase transition temperature, such as those of DPPC/POPG/PA and DPPC/POPC/PA. In contrast, more fluid (DPPC/POPG) or excessively rigid (DPPC/PA) KL4‐containing membranes fail in their ability to adsorb rapidly onto and spread at the air–water interface.