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.

Influence of the developmental state of valvular lesions on the antimicrobial activity of cefotaxime in experimental enterococcal infections

Cefotaxime has little antimicrobial activity in vitro against most strains of enterococci, as measured by conventional MICs and MBCs. However, the MICs of cefotaxime against many enterococci are markedly reduced by the addition of serum to the test medium. To assess the relevance of this observation in vivo, we examined the efficacy of cefotaxime in experimental Streptococcus faecalis endocarditis. Since response to antimicrobial agents may vary with the degree of vegetation development, therapeutic efficacy was assessed both in rabbits with newly formed vegetations and in rabbits with well-developed endocardial lesions. Peak serum levels of cefotaxime (50.1 +/- 20.0 micrograms/ml) exceeded the MIC in medium supplemented with serum (4 micrograms/ml), but not in Mueller-Hinton broth alone (greater than 64 micrograms/ml). After 4 days of therapy, animals with newly formed lesions (therapy initiated 1 h after infection, transvalvular catheters removed) had lower mean vegetation bacterial titers than did untreated controls. Among animals with mature vegetations (therapy initiated 12 h after infection, catheters indwelling), the rate of mortality was significantly reduced by cefotaxime therapy. However, no difference in vegetation titers was observed. Thus, cefotaxime demonstrated antienterococcal activity within newly formed vegetations, but did not inhibit bacterial proliferation within well-established vegetations.

Laryngeal and hypopharyngeal carcinomas after (chemo)radiotherapy: a diagnostic dilemma

PURPOSE OF REVIEW: During recent years, (chemo)radiotherapy has evolved into a primary treatment modality for both early and advanced laryngeal and hypopharyngeal carcinomas. Head and neck surgeons will be concerned more frequently with patients presenting symptoms and signs suggesting recurrent tumor or complications of (chemo)radiotherapy. RECENT FINDINGS: Analysis of histologic characteristics and tumor spread of recurrent carcinomas on whole-organ slices of salvage laryngectomy specimens showed that recurrent laryngeal carcinomas are often present with multiple tumor foci dispersed in different regions; furthermore, they may develop beneath an intact mucosa. Only a few articles analyze the reliability of laryngoscopy and biopsy in detecting recurrences after (chemo)radiotherapy: the number of false negative biopsies is relatively high. The differentiation between radionecrosis and tumor recurrence is difficult by computed tomography scan and magnetic resonance imaging in many cases. Positron emission tomography-computed tomography and diffusion-weighted magnetic resonance imaging are promising diagnostic modalities to detect or exclude persistent or recurrent disease after (chemo)radiotherapy. SUMMARY: Endoscopy with biopsy, computed tomography scan and conventional magnetic resonance imaging present several deficiencies in diagnosing recurrent disease after (chemo)radiotherapy. New imaging modalities such as positron emission tomography-computed tomography and diffusion-weighted magnetic resonance imaging show promising results, increasing the diagnostic efficacy.

[Oral erythroplakia and erythroleukoplakia: red and red-white dysplastic lesions of the oral mucosa--part 2: cytodiagnosis, pathogenesis, therapy, and prognostic aspects]

The second part of the present review article presents and discusses the current literature regarding cytodiagnostic aspects, pathogenesis, therapy, incidence of recurrence, and malignant transformation rate of oral erythroplakia (OE) and oral erythroleukoplakia (OEL). Oral cytopathology, eventually in combination with DNA cytometry, can add valuable information to conventional histopathology, but is not able yet to replace the aforementioned. Numerous molecular genetic variants have been studied in precancerous lesions to gain knowledge about the prognosis of these lesions. Still, there are no evidence-based parameters available to safely detect precursor lesions that will undergo malignant transformation in the future. Excision of OE and OEL should be performed with a margin of safety using the CO2 laser or a scalpel. Data about incidence of recurrence and malignant tranformation rates of OE are mostly based upon case reports or case series. The OEL has a significantly higher risk of malignant transformation than oral leukoplakias.

[Oral erythroplakia and erythroleukoplakia: red and red-white dysplastic lesions of the oral mucosa--part 1: epidemiology, etiology, histopathology and differential diagnosis]

Oral erythroplakia (OE) and oral erythroleukoplakia (OEL; synonym: speckled leukoplakia) are working diagnoses for red and red-white lesions of the oral mucosa after exclusion of all other possible diagnoses for lesions with a similar clinical appearance. A good knowledge of oral medicine and possible differential diagnoses of oral mucosal pathologies is mandatory to correctly detect OE and OEL on this exclusion basis. In the present review article in a series of two, epidemiologic data, etiologic factors, possible differential diagnoses, and the histopathologic characteristics of OE and OEL will be presented and discussed regarding the current literature. A thorough histopathologic examination of these epithelial precursor lesions is mandatory to recognise the presence and the severity of epithelial dysplasia, which is a decisive factor for the subsequent treatment planning.

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.

Elective implantation of sirolimus-eluting stents for bifurcated and non-bifurcated unprotected left main coronary artery lesions: clinical outcomes at one year

AIMS: Recent studies of drug-eluting stents for unprotected left main coronary artery (LMCA) disease have been encouraging. We examined the performance of sirolimus-eluting stents (SES) for this indication. METHODS AND RESULTS: This retrospective study included 228 consecutive patients (mean age = 68 +/- 11 years, 80.6% men, 26.3% diabetics) who underwent implantation of SES for de novo LMCA stenoses. The mean additive and logistic EuroSCOREs were 5.2 +/- 3.9 and 8.2 +/- 13.2, respectively. The main objective of this study was to measure the rate of major adverse cardiac events (MACE), including death, myocardial infarction and target lesion revascularisation (TLR) at 12 months. Other objectives were to measure the rates of in-hospital MACE and 12-month TLR. Outcomes in 143 patients with (BIF+ group), versus 84 patients without (BIF-group) involvement of the bifurcation were compared. The pre-procedural percent diameter stenosis (%DS) was 60.1 +/- 11.2 in the BIF+ versus 54.7 +/- 12.2% in the BIF- group (p=0.008), and decreased to 18.0 +/- 9.7 and 13.9 +/- 11.3%, respectively (ns), after SES implant. The overall in-hospital MACE rate was 3.5%, and similar in both subgroups. The 1-year MACE rate was 14.5% overall, 16.8% in the BIF+ and 10.7% in the BIF- subgroup (ns). CONCLUSIONS: SES implants in high-risk patients with LMCA stenoses were associated with a low 1-year MACE rate. Stenting of the bifurcation was associated with significant increases in neither mortality nor 1-year MACE rate.

Rotational atherectomy followed by drug-eluting stent implantation (Rota-DES): a rational approach for complex calcified coronary lesions

Rotational atherectomy has been regaining interest over the last couple of years after it almost has disappeared from most interventional catheterization laboratories for several years due to failure to prove its original concept of improving long term results of percutaneous coronary interventions (PCI) as was repeatedly shown in studies in the 1990s. Its revival coupled the introduction of drug-eluting stents (DES); these devices have led to treating much more complex lesions and high-risk patients by PCI. However, real-world experience suggested that off-label use of DES is associated with a higher rate of early and late stent thrombosis. Therefore, more attention is now being paid to the initial implantation technique of DES including aggressive lesion preparation to facilitate stent delivery and expansion. The limited studies with rot-ablation and DES showed promising results with no long term safety concerns. In these studies, a subtle observation was made suggesting that rot-ablation prior to DES implantation in such lesions may have an add-on effect on long term outcome compared to DES alone. An ongoing multicenter study is investigating such effect among complex calcified coronary lesions. Even if this additive benefit does not prove true, rot-ablation remains an efficient tool for preparing certain lesions to facilitate effective and safe DES implantation. Therefore, interventional training programs should focus on this difficult technique to bridge the gap of experience which resulted from neglecting it for several years. In this regard, dedicated courses at experienced sites as well as medical simulation may be appropriate.

Toll-like receptor 2 is highly expressed in lesions of acne inversa and colocalizes with C-type lectin receptor

BACKGROUND: Acne inversa (hidradenitis suppurativa) is a chronic inflammatory and cicatricial disorder that affects skin areas rich in apocrine glands and terminal hairs, such as perineum and axillae. The exact pathogenesis of the disease is not well understood and the mechanisms by which bacterial superinfection contributes to the disease progression are not clear. Toll-like receptors (TLRs) expressed by inflammatory cells play a crucial role in the innate immune response to bacteria. OBJECTIVES: We sought to investigate the role of TLR2 in the pathogenesis of acne inversa. METHODS: We investigated the expression of TLR2 using real-time polymerase chain reaction analysis and immunohistochemical stainings of tissue samples from patients with acne inversa. Furthermore, we phenotypically characterized the infiltrating cells and their expression of TLR2. RESULTS: Compared with normal skin, a highly increased in situ expression of TLR2 in acne inversa skin lesions was found at both the mRNA and the protein level. The most abundant cells in the dermal infiltrate of acne inversa were CD68+ macrophages, CD209+ dendritic cells (DCs) and CD3+ T cells. CD19+ B cells and CD56+ natural killer cells were found only in small numbers. Double staining with fluorescence-labelled antibodies showed that TLR2 was expressed by infiltrating macrophages (CD68+) and DCs (CD209+). Flow cytometric analysis of isolated infiltrating cells further confirmed surface expression of TLR2 by macrophages and DCs. CONCLUSIONS: These data indicate that the enhanced expression of TLR2 by infiltrating macrophages and DCs may contribute to the pathogenesis of inflammatory lesions of acne inversa.

Neoplastic invasion of laryngeal cartilage: reassessment of criteria for diagnosis at MR imaging

PURPOSE: To evaluate whether proposed diagnostic criteria applied to magnetic resonance (MR) images of patients with laryngeal and hypopharyngeal carcinoma may be used to distinguish neoplastic from inflammatory involvement of the laryngeal cartilages. MATERIALS AND METHODS: The radiologic and histopathologic data in 121 consecutive patients with primary squamous cell carcinoma of the larynx (n = 63) or hypopharynx (n = 58) who underwent MR imaging before laryngectomy formed the basis of this retrospective study. Patient consent for retrospective chart review was waived by the institutional review board. All laryngectomy specimens were processed with a dedicated histopathologic whole-organ slice technique. MR images were evaluated by two readers according to established ("old") and proposed ("new") diagnostic criteria on the basis of the signal intensity behavior of cartilage on T2-weighted images and contrast material-enhanced T1-weighted images compared with that of the adjacent tumor. Specifically, with the new criteria, T2-weighted or postcontrast T1-weighted cartilage signal intensity greater than that of the adjacent tumor was considered to indicate inflammation, and signal intensity similar to that of the adjacent tumor was considered to indicate neoplastic invasion. The results of the MR image interpretation were compared with the histologic reference standard. RESULTS: The area under the receiver operating characteristic curve for the new criteria (0.94) was nominally but significantly larger than that for the old criteria (0.92) (P = .01). Overall specificity was significantly improved (82% for new vs 74% for old criteria, P < .001) and was greatest for the thyroid cartilage (75% for new vs 54% for old criteria, P < .001) with the new criteria. The sensitivities of the established and the proposed criteria were identical. CONCLUSION: The proposed MR imaging criteria enable improved differentiation of neoplastic cartilage invasion from peritumoral inflammation.

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.