Low-field Mri and arthroscopy of meniscal lesions in ten dogs with experimentally induced cranial cruciate ligament insufficiency

Little is known about the magnetic resonance imaging (MRI) appearance of canine meniscal lesions. The aim of this study is to describe the MR appearance of meniscal lesions in dogs with experimentally induced cranial cruciate ligament (CCL) deficiency. The pilot study revealed dogs weighing approximately 10 kg to be too small for meniscal evaluation on low-field MRI. In the main study, dogs weighing approximately 35 kg were used. The left CCL was transected and low-field MRI was performed regularly until 13 months post-surgery. Normal menisci were defined as grade 0. Intrameniscal lesions not reaching any surface corresponded to grade 1 if focal and to grade 2 if linear or diffuse. Grade 3 lesions consisted in linear tears penetrating a meniscal surface. Grade 4 lesions included complex signal changes or meniscal distortion. Between 2 and 13 months post-surgery, all dogs developed grade 4 lesions in the medial meniscus. Most of them corresponded to longitudinal or bucket handle tears on arthroscopy and necropsy. Two dogs showed grade 3 lesions reaching the tibial surface of the lateral meniscus on MRI but not in arthroscopy. Such tears are difficult to evaluate arthroscopically; MRI provides more accurate information about the tibial meniscal surface. Grades 1 and 2 lesions could not be differentiated from presumably normal menisci with our imaging technique. An MRI grading system better adapted to canine lesions has yet to be developed. MRI is a helpful tool for the diagnosis of complete tears in the canine meniscus, especially in larger dogs.

Treating open carious lesions in anxious children with ozone. A prospective controlled clinical study

PURPOSE: To determine whether the treatment of dental caries with ozone was possible in apprehensive children and to ascertain whether ozone reverses caries in open single-surface lesions. Further, the influence of ozone on laser fluorescence was investigated. METHODS: 82 lesions in 28 children with at least two open single-surface lesions were assessed. The children were anxious and were judged by the referring dentist as non-treatable. For each test lesion, which was treated with ozone, a control lesion was left without ozone treatment. Hardness and laser fluorescence values were assessed and the changes for hardness and laser fluorescence values in the test lesion were compared with the values in the control lesion after 2, 4, 6, and 8 months. RESULTS: 94 percent of the children were treatable and 93% lost their dental anxiety. The hardness values improved significantly in the ozone-treated test lesions after 4, 6, and 8 months (P< 0.05) compared with baseline while the control lesions had no significant change in hardness at any recall interval. Comparing the differences between test and control teeth over time, the laser fluorescence values improved, however the improvement was not statistically significant (P> 0.05). The use of ozone resulted in an average reduction of 13% of the laser fluorescence values immediately after the ozone treatment.

Gender and the relationship between traumatic childhood experiences and pain in adulthood

OBJECTIVES AND METHODS: Gender differences regarding 17 childhood experiences, thought to have traumatising potential (Traumatic Childhood Experiences = TCE), and pain behaviour in adulthood were assessed using a self-administered, anonymously filled-out questionnaire. Patients were consecutively accrued in the offices of practicing physicians. Three research questions were formulated: 1) Are specific TCE reported more frequently in male and female patients with the diagnosis "Pain Associated with Psychological Factors" (PP), compared to patients with "Pain, explained by Organic Processes" (OP), and "Patients with Diseases without Pain" (OD)? 2) Do PP-men and PP-women differ in reporting TCE?; 3) Are specific TCE correlated with Pain Duration, -Intensity and Number of Operations? RESULTS: 1). TCE occurred more frequently in PP-men and PP-women compared to OP- and OD-patients. 2). The PP-women reported much more TCE-items than the PP-men. 3). Duration and Intensity of adult pain associated with psychological factors correlated with certain TCE-items. CONCLUSIONS: The three research questions can be answered by "yes". In patients with pain which has been impossible to diagnose and/or has resisted conventional forms of therapy, TCE (verbal, physical and sexually abusive) have to be looked for, because they often explain adult pain. Unnecessary examinations and surgery can be avoided and therapies can be tailored for the individual patient.

MRI characteristics and histology of bone marrow lesions in dogs with experimentally induced osteoarthritis

Signal changes within the bone marrow adjacent to osteoarthritic joints are commonly seen on magnetic resonance (MR) images in humans and in dogs. The histological nature of these lesions is poorly known. In this study, we describe the MR imaging of bone marrow lesions adjacent to the stifle joints of dogs with experimental osteoarthritis over 13 months. Histology of the proximal tibia at the end of the study was compared with the last MR imaging findings. In five adult dogs, the left cranial cruciate ligament was transected. Post-operatively, MR imaging was performed at 1, 2, 3, 4, 6, 8, and 13 months. Dogs were euthanised after 13 months and histological specimen of the proximal tibia were evaluated. Bone marrow edema like MR imaging signal changes were seen in every MR examination of all dogs in one or more locations of the proximal tibia and the distal femur. Lesions varied in size and location throughout the whole study with the exception of constantly seen lesions in the epiphyseal and metaphyseal region at the level of the tibial eminence. On histology, hematopoiesis and myxomatous transformation of the bone marrow and/or intertrabecular fibrosis without signs of bone marrow edema were consistent findings in the areas corresponding to the MR imaging signal changes. We conclude that within the bone marrow, zones of increased signal intensity on fat suppressed MR images do not necessarily represent edema but can be due to cellular infiltration. Contrary to humans, hematopoiesis is seen in bone marrow edema-like lesions in this canine model of osteoarthritis.

Effects of various forms of calcium added to chewing gum on initial enamel carious lesions in situ

The purpose of this randomized, cross-over in situ study was to determine the effects of 4 chewing gums on artificial caries-like subsurface lesions. Two chewing gums (1 with zinc citrate and 1 without) contained dicalcium phosphate (3.9%), calcium gluconate (1.8%) and calcium lactate (0.45%), 1 chewing gum contained casein phosphopeptide-amorphous calcium phosphate nanocomplexes (0.7%), and another one contained no calcium. Fifteen subjects without current caries activity (7 male, 8 female; mean age: 27.5 +/- 2.5 years) wore removable buccal appliances in the lower jaw with 4 bovine enamel slabs with subsurface lesions. The appliances were inserted immediately before gum chewing for 20 min and then retained for an additional 20 min. This was performed 4 times per day. Every subject chewed 4 different chewing gums over 4 periods of 14 days each. During a fifth period (control) the subjects only wore the appliances without chewing gum. At completion of each period the enamel slabs were embedded, sectioned and subjected to transversal microradiography. With regard to change of mineral loss and of lesion depth no significant differences could be found between chewing gums containing calcium and calcium-free chewing gums. Moreover, the chewing gum groups and the control group did not differ significantly if adjustments were made for baseline values (p > 0.05; ANCOVA). Under the conditions of the present study it may be concluded that the use of chewing gum offers no additional remineralizing benefit to buccal tooth surfaces, even if the chewing gum contains calcium compounds.

Effects of dose reduction on the detectability of standardized radiolucent lesions in digital panoramic radiography

Dose reduction in digital panoramic radiography was studied. Intentional underexposure was performed with the Orthophos DS while six different human mandibles were radiographed. Exposure settings were 69 kV/15 mA (standard), 64 kV/16 mA, and 60 kV/16 mA. Standardized spherical defects, each either 1 or 1.25 mm in diameter, were simulated in 288 of 432 images, and seven observers decided whether defects were present or not. Areas under the receiver operating characteristics curves were calculated. They showed no significant differences in the detectability of the 1-mm defect at 69, 64, or 60 kV. For the 1.25-mm defect, no difference was found between the 69 and 60 kV images, but a statistically significant different detectability was found for 64 kV images in comparison with both 69 and 60 kV images. A dose reduction of up to 43% was ascertained with a Pedo-RT-Humanoid phantom when panoramic radiography was performed at 60 kV/16 mA. The conclusion is that with the Orthophos DS, it seems possible to reduce the dose rate of x-rays without loss of diagnostic quality in the case of radiolucent changes.

Clinical performance of a new laser fluorescence device for detection of occlusal caries lesions in permanent molars

OBJECTIVES: To determine the clinical performance of a laser fluorescence device (DIAGNOdent pen, KaVo) to discriminate between different occlusal caries depths (D(0)-D(1-4); D(0-2)-D(3,4)) in permanent molars. METHODS: In this prospective, randomized two-centre-study 120 sound/uncavitated carious sites in 120 patients were measured after visual and radiographic caries assessment. In cases of operative intervention (n=86), the lesion depths after caries removal were recorded (reference). In cases of preventive intervention (n=34), the sites were reassessed visually/radiographically after 12 months to verify the status assessed before (reference). The discrimination performance was determined statistically (Mann-Whitney test, Spearman's rho coefficient, and areas under the receiver operating characteristic curves (AUCs)). Sensitivities (SE) and specificities (SP) were plotted as a function of the measured values and cut-off values for the mentioned thresholds suggested. RESULTS: Sound sites (n=13) had significantly minor fluorescence values than carious sites (n=107) (P<0.0001) as had sites with no/enamel caries (n=63) compared to dentinal caries (n=57). The AUCs for the same discriminations were 0.92 and 0.78 (P<0.001). For the D(0)-D(1-4) threshold, a cut-off at a value of 12 (SE: 0.88, SP: 0.85) and for the D(0-2)-D(3,4) threshold at 25 (SE: 0.67, SP: 0.79) can be suggested. A moderate positive correlation between the measurements and the caries depths was calculated (rho=+0.57, P=0.01). CONCLUSION: Within this study, the device's discrimination performance for different caries depths was moderate to very good and it may be recommended as adjunct tool in the diagnosis of occlusal caries.

Virtopsy -- noninvasive detection of occult bone lesions in postmortem MRI: additional information for traffic accident reconstruction

In traffic accidents with pedestrians, cyclists or motorcyclists, patterned impact injuries as well as marks on clothes can be matched to the injury-causing vehicle structure in order to reconstruct the accident and identify the vehicle which has hit the person. Therefore, the differentiation of the primary impact injuries from other injuries is of great importance. Impact injuries can be identified on the external injuries of the skin, the injured subcutaneous and fat tissue, as well as the fractured bones. Another sign of impact is a bone bruise. The bone bruise, or occult bone lesion, means a bleeding in the subcortical bone marrow, which is presumed to be the result of micro-fractures of the medullar trabeculae. The aim of this study was to prove that bleeding in the subcortical bone marrow of the deceased can be detected using the postmortem noninvasive magnetic resonance imaging. This is demonstrated in five accident cases, four involving pedestrians and one a cyclist, where bone bruises were detected in different bones as a sign of impact occurring in the same location as the external and soft tissue impact injuries.

Ethanol-induced cytochrome P4502E1 causes carcinogenic etheno-DNA lesions in alcoholic liver disease

Oxidative stress is thought to play a major role in the pathogenesis of hepatocellular cancer (HCC), a frequent complication of alcoholic liver disease (ALD). However, the underlying mechanisms are poorly understood. In hepatocytes of ALD patients, we recently detected by immunohistochemistry significantly increased levels of carcinogenic etheno-DNA adducts that are formed by the reaction of the major lipid peroxidation product, 4-hydroxynonenal (4-HNE) with nucleobases. In the current study, we show that protein-bound 4-HNE and etheno-DNA adducts both strongly correlate with cytochrome P450 2E1 (CYP2E1) expression in patients with ALD (r = 0.9, P < 0.01). Increased levels of etheno-DNA adducts were also detected in the liver of alcohol-fed lean (Fa/?) and obese (fa/fa) Zucker rats. The number of nuclei in hepatocytes stained positively for etheno-DNA adducts correlated significantly with CYP2E1 expression (r = 0.6, P = 0.03). To further assess the role of CYP2E1 in the formation of etheno-DNA adducts, HepG2 cells stably transfected with human CYP2E1 were exposed to ethanol with or without chlormethiazole (CMZ), a specific CYP2E1 inhibitor. Ethanol increased etheno-DNA adducts in the nuclei of CYP2E1-transfected HepG2 cells in a concentration-dependent and time-dependent manner, but not in vector mock-transfected control cells. CMZ blocked the generation of etheno-DNA adducts by 70%-90% (P < 0.01). CONCLUSION: Our data support the assumption that ethanol-mediated induction of hepatic CYP2E1 leading inter alia to highly miscoding lipid peroxidation-derived DNA lesions may play a central role in hepatocarcinogenesis in patients with ALD.

Isolated development of inner (wall) caries like lesions in a bacterial-based in vitro model

The study conducted in a bacterial-based in vitro caries model aimed to determine whether typical inner secondary caries lesions can be detected at cavity walls of restorations with selected gap widths when the development of outer lesions is inhibited. Sixty bovine tooth specimens were randomly assigned to the following groups: test group 50 (TG50; gap, 50 microm), test group 100 (TG100; gap, 100 microm), test group 250 (TG250; gap, 250 microm) and a control group (CG; gap, 250 microm). The outer tooth surface of the test group specimens was covered with an acid-resistant varnish to inhibit the development of an outer caries lesion. After incubation in the caries model, the area of demineralization at the cavity wall was determined by confocal laser scanning microscopy. All test group specimens demonstrated only wall lesions. The CG specimens developed outer and wall lesions. The TG250 specimens showed significantly less wall lesion area compared to the CG (p < 0.05). In the test groups, a statistically significant increase (p < 0.05) in lesion area could be detected in enamel between TG50 and TG250 and in dentine between TG50 and TG100. In conclusion, the inner wall lesions of secondary caries can develop without the presence of outer lesions and therefore can be regarded as an entity on their own. The extent of independently developed wall lesions increased with gap width in the present setting.

Comparison of the immediate effects of gaseous ozone and chlorhexidine gel on bacteria in cavitated carious lesions in children in vivo

Clinical application of ozone gas has been shown to arrest the progression of dentinal caries in children. In this study, we compare the immediate effects of gaseous ozone and chlorhexidine gel on bacteria in cavitated carious lesions in children. Forty children, each with at least two open occlusal carious lesions, were enrolled in the study. Two teeth were chosen randomly. In one lesion, overlying soft biological material was removed, whilst the other lesion was not excavated. Cavities were rinsed with sterile water and dried with air. A standardised sample was taken from the mesial part of each lesion. Then, gaseous ozone (HealOzone) or 1% chlorhexidine gel (Corsodyl) was applied for 30 s on both lesions of 20 children each, and a second sample was taken from the distal part of each lesion. The anaerobic microbiota was cultivated; the number of colony forming units was calculated per milligram sample. The two-sided paired t test showed no significant (P > 0.05) differences in the reduction of total bacterial counts per milligram comparing samples before and after ozone or chlorhexidine application. The tests also showed no statistically significant difference whether the superficial decayed dentine had been removed before ozone or with chlorhexidine treatment or not. It can be concluded that gaseous ozone or chlorhexidine gel application for 30 s to deep occlusal carious cavities had no significant immediate antimicrobial effects whether the superficial decayed layers dentine were removed or not.

PET-CT-guided interventions in the management of FDG-positive lesions in patients suffering from solid malignancies: initial experiences

Positron emission tomography-computed tomography (PET-CT) has gained widespread acceptance as a staging investigation in the diagnostic workup of malignant tumours and may be used to visualize metabolic changes before the evolution of morphological changes. To make histology of PET findings without distinctive structural changes available for treatment decisions, we developed a protocol for multimodal image-guided interventions using an integrated PET-CT machine. We report our first experience in 12 patients admitted for staging and restaging of breast cancer, non-small cell lung cancer, cervical cancer, soft tissue sarcoma, and osteosarcoma. Patients were repositioned according to the findings in PET-CT and intervention was planned based on a subsequent single-bed PET-CT acquisition of the region concerned. The needle was introduced under CT guidance in a step-by-step technique and correct needle position in the centre of the FDG avid lesion was assured by repetition of a single-bed PET-CT acquisition before sampling. The metabolically active part of lesions was accurately targeted in all patients and representative samples were obtained in 92%. No major adverse effects occurred. We conclude that PET-CT guidance for interventions is feasible and may be promising to optimize the diagnostic yield of CT-guided interventions and to make metabolically active lesions without morphological correlate accessible to percutaneous interventions.