Differential chemokine expression patterns in tonsillar disease.

Expression profiles of CXC- and CC-chemokines in various forms of tonsillar disease were studied to evaluate whether certain chemokines play a predominant role in a specific subset of tonsillar disease. Total RNA was isolated from 89 biopsies (21 hyperplastic palatine tonsils, 25 adenoids, 16 chronic inflammatory palatine tonsils and 27 chronic inflammatory palatine tonsils with histological prove of acute inflammation), reverse transcribed and subjected to PCR amplifying IL-8, Gro-alpha, eotaxin-1, eotaxin-2, MCP-3, MCP-4 and RANTES. 2% agarose gel electrophoresis revealed a predominance of IL-8 in the chronic inflammatory palatine tonsil group compared to tonsillar hyperplasia. Furthermore, eotaxin-2 was strongly overexpressed in adenoid samples compared to chronic inflammatory specimens. Our data suggest that the majority of diseases related to adenoid formation are mediated via an eotaxin-2 expression, whereas chronic inflammatory tonsillitis is associated with IL-8 upregulation. These data imply that adenoids are related to a Th-2, and chronic inflammatory tonsillitis to a Th-1 based immune response.

Activation of the cell membrane angiotensin AT2 receptors in human leiomyosarcoma cells induces differentiation and apoptosis by a PPARγ - dependent mechanism.

Angiotensin II (Ang II), the main effector peptide of the renin-angiotensin system (RAS), acting on AT1 and AT2 receptors participates in the regulation of proliferation, differentiation and apoptosis in tumour cells. The peroxisome-proliferator activated receptor γ (PPARγ) and its ligands exert anti-tumour effects in various human cancer cell lines. The present study investigates the effects initiated by AT1- and AT2 receptor stimulation in SK-UT-1 cells, a human leiomyosarcoma cell line, and clarifies the role of the PPARγ in the AT2 receptor-induced differentiation and apoptosis.Selective stimulation of AT1- and AT2 receptors was achieved by incubation of the cells with Ang II (10-6 M) in the presence of the selective AT2 receptor antagonist, PD 123177 (10-6 M) and the AT1 receptor antagonist, losartan (10-5 M), respectively, the selective PPARγ antagonist, GW 9662, was used at concentration 10-6 M. The expression of smooth muscle cell differentiation markers, SM22α and calponin, was analysed at RNA- and protein levels using RT PCR and Western blot, which was also used to quantify Bcl-2-, Bax- and cleaved caspase-3 proteins. The translocation of the AT2-receptor interacting protein 1 (ATIP1) to the nuclei was studied by Western blot and immunofluorescence staining. The mitochondrial status and the metabolic activity in response to AT1- and AT2 receptor activation were assessed by the quantification of 99mTc - sestamibi and 2´-deoxy-2´-[18F]fluoro-D-glucose uptake.AT1 receptor stimulation did not exert any profound effects in quiescent SK-UT-1 cells. The effects induced by Ang II acting on AT2 receptors were time-dependent. A short, 3 - 6 h lasting stimulation promotes differentiation, i.e increases in the mRNA- and protein levels of SM22α and calponin, whereas a sustained stimulation for 48 h activates the intrinsic apoptotic pathway, as evidenced by reduced cell numbers, down-regulation of the anti-apoptotic Bcl-2 protein and increased levels of the Bax protein and cleaved caspase-3. The effects were reversed by the PPARγ antagonist, GW 9662, clearly implying a PPARγ-dependent mechanism. Our results also demonstrate a co-localisation of the AT2-receptor interacting protein, ATIP1, and the PPARγ in nuclei of SK-UT-1 cells and an accumulation of ATIP1 in the nuclear fraction in response to AT2 receptor stimulation. The regulation of the differentiation and apoptosis via the AT2 receptor favours an important functional role of this receptor in quiescent, slow-cycling SK-UT-1 cells and provides the rationale for the use of AT1 receptor antagonists for the treatment of human leiomyosarcomas.

Expression of mRNA and protein of IL-18 and its receptor in human follicular granulosa cells.

PURPOSE: There is no information available about the IL-18 receptor in ovarian follicles, so the present study attempts to demonstrate the expression of IL-18 and its receptor in human granulosa cells (GCs). METHODS: To evaluate the concentration of IL-18 in serum and follicular fluid (FF), we collected serum and FF from 102 women undergoing oocyte retrieval. Also, to detect expression of IL-18 and its receptor by luteinized GCs, these cells were pooled six times from a total of twenty individual patients with 5-16 follicles each. The IL-18 concentration was determined by ELISA and the expression of IL-18 and its receptor by immunocytochemistry and reverse transcription polymerase chain reaction. RESULTS: Our results showed that the median IL-18 concentration in serum, 159.27 pg/ml (IQR 121.41-210.1), was significantly higher than in FF, 142.1 pg/ml (IQR 95.7-176.5), p < 0.001. Moreover, we found that IL-18 and its receptor are expressed by GCs. CONCLUSION: The presence of IL-18 in FF and the expression of IL-18 and its receptor by GCs suggest an important role for this cytokine in ovarian function.

Differential expression of antimicrobial peptides in psoriasis and psoriatic arthritis as a novel contributory mechanism for skin and joint disease heterogeneity.

OBJECTIVES: This study tested the hypothesis that a differential innate immune antimicrobial peptide (AMP) profile was evident between the skin and joints in psoriasis and psoriatic arthritis (PsA) and that PsA synovitis may have a distinct AMP pattern compared to other arthropathies. METHOD: Twenty-two cases had knee biopsies [10 PsA, eight rheumatoid arthritis (RA), and four osteoarthritis (OA)]. Lesional and non-lesional skin biopsies in psoriasis and control tissue were also obtained (n = 4 each). Immunohistochemistry with semi-quantitative scoring of both synovium and skin was performed using the following panel of AMPs: S100 A8, S100 A9, human neutrophil peptides 1-3 (HNP1-3), human ß-defensins 2 and 3 (hBD-2 and hBD-3), cathelicidin LL-37, psoriasin (S100 A7), and ribonuclease 7 (RNase 7). RESULTS: Similar expression of S100 A8, S100 A9, and HNP1-3 was detectable in PsA and RA synovium but only in the synovium sublining layer (SSL). No expression of psoriasin, RNase 7, hBD-2, and hBD-3 could be detected in the synovial tissue of PsA, RA, or OA. All psoriasis skin samples exhibited broad expression of all investigated AMPs, with strong keratinocyte expression. CONCLUSIONS: Given that some AMPs, especially hBD-2, are genetically linked to psoriasis and are only expressed in the skin, these findings show how differential AMP expression in innate immune responses may contribute to disease heterogeneity between PsA and psoriasis and provides a genetic basis for the non-progression of psoriasis subgroups to PsA.

Changes of salivary estrogen levels for detecting the fertile period.

OBJECTIVES: Is the saliva test, Geratherm ovu control, as accurate as the established urinary luteinizing hormone (LH) test for detecting ovulation and the following the fertile period? STUDY DESIGN: The voluntary participants were 74 healthy women with regular menstrual cycles and not using any hormonal contraceptives. The women used Geratherm ovu control, a small plastic hand-held microscope, for detecting the fertile period. A drop of saliva from sublingual was put onto the lens of the microscope. Three results were possible: non-fertile (dot pattern), transitional and fertile (ferning pattern). The participants performed the saliva test from the 5th till the 22nd day of the menstrual cycle and noted the respective result in a table. In addition to Geratherm ovu control, the EXACTO test for determining urinary LH concentration and the time of peak fertility was also performed. RESULTS: Positive LH shows a sharp increase beginning on the 10th cycle day with a maximum on the 17th cycle day. The curve for positive saliva and questionable positive saliva (one curve) is almost parallel with the curve for positive LH, reaching a maximum on the 16th cycle day. There is a high level of conformity for the same test results from the 5th (100%) till the 14th (84%) cycle day and from the 18th (80%) till the 22nd (96%) cycle day which corresponds to the pre- and post-ovulatory period. CONCLUSION: The saliva and the LH test both detect the fertile window of a menstrual cycle. Caused by the different hormones (estrogen for the saliva and LH for the LH test) leading to the respective positive test results, saliva turns positive 24h before LH. Consequently, the saliva test can be used as an ovulation test and help women maximize their chances of conceiving. There is also a high congruence between LH and saliva in the pre- and post-ovulatory period, indicating that the saliva test can also be used for contraception purposes.

LC-MS/MS based determination of basal- and ACTH-stimulated plasma concentrations of 11 steroid hormones: implications for detecting heterozygote CYP21A2 mutation carriers.

OBJECTIVE: Heterozygosity in 21-hydroxylase deficiency (21OHD) has been associated with hyperandrogenemic symptoms in children and adults. Moreover, the carrier status is mandatory for genetic counseling. We aimed at defining a hormonal parameter for carrier detection by mass spectrometry. DESIGN: Eleven basal and ACTH-stimulated steroid hormones of heterozygous carriers of CYP21A2 mutations and control individuals were compared. METHOD: Hormones were determined in plasma samples by liquid chromatography tandem mass spectrometry (LC-MS/MS) in 58 carriers (35 males, 23 females, age range 6-78 years) and 44 random controls (25 males, 19 females, age range 8-58 years). RESULTS: Heterozygotes could be identified best applying the 17-hydroxyprogesterone+21-deoxycortisol/cortisol×1000 ((17OHP+21S)/F×1000) equation 30  min after ACTH injection. An optimal cut-off value of 8.4 provided 89% sensitivity and specificity. Considering this data and a published frequency of heterozygotes of 1/50 to 1/61, the positive predictive value (PPV) of this cut-off is 12%. Of note, the negative predictive value (NPV) excluding heterozygosity in a given patient is 99.8%. CONCLUSION: Considering only marginal biochemical effects anticipated from heterozygosity, the stimulated ((17OHP+21S)/F×1000) identifies and excludes heterozygotes remarkably well. Nevertheless, LC-MS/MS cannot replace genetic testing, since sensitivity and specificity did not reach 100%. However, due to the considerably high NPV of the optimal cut-off and to a specificity of even 100% applying a cut-off higher than 14.7, hormonal assessment of heterozygosity can be of significant aid in conditions with limited access to genetic testing, as in some health care systems. The ((17OHP+21S)/F×1000) equation can guide diagnostic considerations in the differential diagnosis of hyperandrogenism.

In vitro comparison of different carrier materials with rat bone marrow MSCs.

OBJECTIVES: Injectable or implantable scaffolds seeded with autologous chondrogenic cells may represent a promising option for treatment of cartilage defects in the future. Current problems with the autologous chondrocyte implantation including dedifferentiation and the development of fibrocartilage suggest the use of alternative chondrogenic cell sources such as mesenchymal stromal cells (MSCs). The aim of this study was to compare the early effects of different scaffolds on the proliferation and metabolic activity of chondrogenic MSCs in vitro. MATERIALS AND METHODS: Multipotent stromal cells were isolated from rat bone marrow, phenotyped by flow cytometry, and differentiated into distinct lineages proved by lineage-specific staining and gene expression (RT-PCR) pattern. Cell proliferation on Tutodent® Membrane, Bio-Gide®, TissuFleece E, and Belotero® Soft was quantified by the MTT and WST-1 assay and direct determination of total cell numbers. Potential cytotoxic effects of eluates obtained from the materials were quantified by lactate dehydrogenase (LDH) and 5-bromo-2-deoxyuridine (BrdU) assay. RESULTS: TissuFleece E displayed the best results regarding cell proliferation on the biomaterials and metabolic activity (MTT, WST-1) (p < 0.001). Yet, the eluates of TissuFleece E caused an increased LDH release and lower values in the BrdU test. Cell proliferations on Bio-Gide®, Tutodent® Membrane, and Belotero® Soft were similar to the control. The eluates of Belotero® Soft exhibited the highest LDH release and lowest values in the BrdU assay (p < 0.05). CONCLUSIONS: Our results support the use of Tissufleece E as scaffold for chondrogenic rat MSCs. However, it should be prewashed with culture medium before seeding of the cells. CLINICAL RELEVANCE: Tissufleece E may serve as a promising carrier material for chondrogenic MSCs for cartilage tissue engineering attempts.

Investigation of the agreement of a continuous non-invasive arterial pressure device in comparison with invasive radial artery measurement.

BACKGROUND: Arterial pressure (AP) monitoring should be accurate, easy to use, free of risks, and ideally continuous. The continuous non-invasive arterial pressure (CNAP) device is non-invasive and provides continuous pressure readings. This study was performed to compare the agreement of CNAP and invasive AP monitoring. METHODS: Ninety patients undergoing surgery under general anaesthesia were enrolled. Invasive pressure monitoring was established at the radial artery. CNAP monitoring using a finger sensor recording was begun before induction of anaesthesia. Statistical analysis was conducted with the Bland-Altman method for comparisons of repeated measures. RESULTS: We obtained 16 843 valid pressure readings from 85 patients. Mean (sd) bias during maintenance of anaesthesia was: systolic AP: 4.2 (16.5) mm Hg; mean AP (MAP): -4.3 (10.4) mm Hg; and diastolic AP: -5.8 (6) mm Hg. The results of a subgroup analysis of patients who had a mean intra-arterial pressure of <70 mm Hg were as follows: systolic pressure: -0.3 (9.7) mm Hg; mean pressure: -6.8 (7.6) mm Hg; and diastolic pressure: -7.9 (7.2) mm Hg. Bias and percentage error during the induction period were greater in both the main and subgroup analyses, probably due to recalibration being omitted after induction. CONCLUSIONS: The CNAP monitor showed an acceptable agreement and was interchangeable with invasive pressure monitoring for MAP during normotensive conditions. During induction of anaesthesia and when the AP was low, the agreement was less good and interchangeability was not achieved. These results suggest that CNAP is not statistically equivalent to invasive monitoring during all periods of anaesthesia but may be a useful additional AP monitor.

Biocompatibility of bone graft substitutes: effects on survival and proliferation of porcine multilineage stem cells in vitro.

Bone graft substitutes (BGS) are widely used in clinical practice. For stem cellbased approaches to bone tissue engineering BGS need to show sufficient biocompatibility in the in vitro setting. This study was designed to demonstrate the influence of six different BGS on the proliferation and metabolic activity of porcine mesenchymal multilineage stem cells (pMSC) in vitro. Bone-marrow derived pMSC were cultivated for 24 hours with the eluates of six different BGS. The eluates were generated by incubating the BGS three times in succession for 24 hours with a culture medium and collecting the supernatants. pMSC vitality and proliferation in the presence of eluates from the first, second, and third incubation were assessed by WST-test quantification of metabolically active cells. Culture of pMSC with eluates in all cases resulted in decreased cell numbers in an eluate concentration-dependent manner. At least a 65% loss of cells compared to controls (culture medium without eluates) could be observed in the presence of undiluted eluates. The negative influence of eluates varied significantly among BGS. In all cases, second and third eluates were less potent in their negative effects on cellular vitality/proliferation. In conclusion, the BGS examined here should be submitted to thorough preincubation before in vitro use for cell-based constructs to maximize cell viability for the tissue engineering of bone.

MR imaging findings in patients with secondary intracranial hypertension.

BACKGROUND AND PURPOSE: IH can alter the configuration of anatomic structures of the central nervous system. We determined the sensitivity and specificity of MR imaging to detect these changes in patients with secondary IH. MATERIALS AND METHODS: Patients (n = 36) with IH were prospectively investigated with MR imaging and were matched to 36 controls. MR images were evaluated for elongation and edema of the optic nerves, protrusion of the optic disc, flattening of the posterior sclera, height of the pituitary gland, and width of the optic nerve sheath. On MRV, we recorded venous sinus abnormalities and measured the luminal width of the superior ophthalmic veins. A grading score was introduced to define cranial venous outflow obstruction. RESULTS: Cranial venous outflow obstruction and ONS hydrops were the most valid signs indicating IH with a sensitivity of 94% and 92% and a specificity of 100% and 89%, respectively. Sensitivities and specificities were 56% and 97% for reduced pituitary height, 64% and 78% for flattening of the posterior sclera, 31% and 97% for widening of the superior ophthalmic veins, 33% and 100% for optic disc protrusion, 14% and 100% for optic nerve edema, and 6% and 100% for elongation of the optic nerve. At least 2 MR imaging findings could be demonstrated in each patient but in none of the controls. The number of positive MR imaging findings correlated with CSF pressure (r = 0.62, P = .01). CONCLUSIONS: The combination of cranial and orbital MR imaging and MRV can be highly sensitive and specific in the diagnosis of patients with IH.

Surgical treatment for brain metastases: Prognostic factors and survival in 309 patients with regard to patient age.

Brain metastases are the most common intracranial tumors. Overall, the only accepted prognostic factors are patient age and performance status. However, several other factors are considered before surgery. We performed a retrospective analysis of 309 patients who underwent surgical resection of newly diagnosed brain metastases between 1994 and 2004. Univariate survival analysis revealed age, performance status, extracranial metastases, complete resection, radiotherapy and re-craniotomy as prognostic indicators. Multivariate analysis determined that patient age, performance status, extracranial metastases, radiotherapy and re-craniotomy are independent factors of prolonged survival. We statistically estimated the age threshold separating patients with favorable outcomes from those with unfavorable prognoses. Using the Kaplan-Meier analysis this threshold can be set at 65 years. Multivariate analysis of patients >65 years revealed the presence of co-morbidities, the number of brain metastases, post-operative performance status and radiotherapy as independent prognostic factors.

Breast ultrasound elastography--results of 193 breast lesions in a prospective study with histopathologic correlation.

PURPOSE: To evaluate the diagnostic performance of ultrasound elastography in breast masses. MATERIAL AND METHODS: 193 lesions (129 benign, 64 malignant) were analyzed with the EUB 8500 Logos-ultrasonic-unit (Hitachi Medical, Japan) and a linear-array-transducer of 7.5-13-MHz. Standard of reference was cytology (FNAfine needle aspiration) or histology (core biopsy). The elastic-score was classified according to a 6-point colour-scale (Ueno classification; 1-3 = benign, 4-5 = malignant). Conventional B-mode ultrasound (US) findings were classified according to the BI-RADS classification. Statistical analysis included sensitivity, specificity, ROC-analysis and kappa-values for intra-/interobserver reliability. RESULTS: The mean score for elasticity was 4.1 ± 0.9 for malignant lesions, and 2.1 ± 1.0 for benign lesions (p < 0.001). With a best cut-off point between elasticity scores 3 and 4, sensitivity was 96.9%, and specificity 76%. Setting a best cut-off point for conventional US between BI-RADS 4 and 5, sensitivity was 57.8%, and specificity 96.1%. Elastography provided higher sensitivity and lower specificity than conventional US, but two lesions with elasticity score 1 were false negative, whereas no lesion scored BI-RADS 1-3 were false negative. ROC-curve was 0.884 for elastography, and 0.820 for conventional US (p < 0.001). Weighted kappa-values for intra-/interobserver reliability were 0.784/0.634 for BI-RADS classification, and 0.720/0.561 for elasticity scores. CONCLUSION: In our study setting, elastography does not have the potential to replace conventional B-mode US for the detection of breast cancer, but may complement conventional US to improve the diagnostic performance.

MR imaging of the optic nerve sheath in patients with craniospinal hypotension.

BACKGROUND AND PURPOSE: Craniospinal hyper- or hypotension leads to morphologic changes in certain intracranial structures. We tested the hypothesis that the amount of CSF in the ONS visible in MR imaging is reduced in patients with CSH. MATERIALS AND METHODS: Nineteen patients with CSH were prospectively studied. Three readers assessed the width of the peri-optical CSF rim at 4 different anatomic positions by using coronal STIR sequences from a 3T MR imaging scanner. The height of the pituitary gland was also measured. Results were compared with normal values obtained with the same imaging technique. Qualitative signs of CSH also recorded were engorgement of venous sinuses, dural enhancement, subdural effusion, narrow ventricles, and sagging brain. RESULTS: CSF signal intensity surrounding the optic nerves was diminished in at least 2 of the 4 positions used for measurements so that decreased diameters of the ONSs were observed in all patients (sensitivity, 100%; specificity, 97%). The height of the pituitary gland was above normal limits in 12 of 19 patients (sensitivity, 63%; specificity, 97%). Frequencies of qualitative signs of CSH varied from 32% to 81%. CONCLUSIONS: The ISSON in patients with CSH is partially or fully collapsed due to reduced CSF content. In comparison with other anatomic markers, this sign showed the highest sensitivity for the diagnosis of patients with CSH in this study.

No correlation between androgen receptor CAG and GGN repeat length and the degree of genital virilization in females with 21-hydroxylase deficiency.

CONTEXT: In 21-hydroxylase (CYP21A2) deficiency (21OHD), the level of in vitro enzymatic function allows for classification of mutation groups (null, A, B, C) and prediction of disease severity. However, genital virilization in affected females correlates only weakly with CYP21A2 mutation groups, suggesting the influence of genetic modifiers. OBJECTIVE: The objective of the study was to investigate the influence of the polymorphic CAG and GGn repeats of the androgen receptor (AR) gene on the degree of genital virilization in 21OHD females. DESIGN AND PATIENTS: Design of the study was the determination of CYP21A2 genotype, degree of genital virilization (Prader stage), and X-weighted biallelic mean of AR CAG and GGn repeat length in 205 females with 21OHD. OUTCOME MEASUREMENTS: Correlation of AR CAG and GGn repeat lengths with Prader stages using nested stepwise logistic regression analysis was measured. RESULTS: CYP21A2 mutation groups null and A showed significantly higher levels of genital virilization than groups B and C (P < 0.01). However, Prader stages varied considerably within mutation groups: null, Prader I-V (median IV); A, Prader I-V (median IV); B, Prader I-V (median III); C, 0-III (median I). Mean GGn repeat length of patients was not significantly associated with Prader stages, classified as low (0-I), intermediate (II-III), or severe (IV-V) (odds ratio per repeat: 0.98, 95% confidence interval 0.71-1.35). In contrast, patients with Prader 0-I showed a trend toward longer CAG repeats without reaching statistical significance (P = 0.07, odds ratio per repeat: 0.82, 95% confidence interval 0.65-1.02). CONCLUSION: Neither CAG nor GGn repeat lengths are statistically significant modifiers of genital virilization in females with 21OHD.

Development of a permanently controllable rotating biopsy device, part II: Competitive in-vitro testing of a cannula-like prototype compared to established end-cut and side-notch biopsy devices.

PURPOSE: To evaluate the quantitative and qualitative efficiency of a permanently controllable biopsy-cannula prototype with lancet-like helically bent cutting edge for safer biopsy compared to established end-cut and side-notch biopsy devices. MATERIALS AND METHODS: Each of the n = 100 specimens per organ and system were obtained by the prototype, an end-cut device and a side-notch device (18 gauge each) using a bovine liver, kidney and myocardium as the biopsy tissue. Quantitatively, the number of fragments, length in mm and weight in mg of the specimen were analyzed. Qualitatively, a histopathological analysis was performed with respect to tissue fragmentation, crush artifact and adequacy of tissue (score per category min. 1 and max 3). To identify significant differences (p < 0.025), chi-square and Kruskal-Wallis tests were calculated in the statistical analysis. RESULTS: For each of the n = 300 specimens, the one-piece fragment/mean length/mean weight were n = 232 / 10.34 mm/ 4.86 mg for the prototype, n = 210 / 12.16 mm/ 5.35 mg for the end-cut system and n = 248 / 11.63 mm/ 4.08 mg for the side-notch system. The differences reached a level of significance with p < 0.001. The mean histopathological score for the prototype/end-cut system/side-notch system was 5.60 / 5.60 / 5.25 for the liver, 5.65 / 4.65 / 4.60 for the kidney and 5.05 / 5.35 / 4.85 for the myocardium. The differences did not reach a level of significance for the liver/kidney/myocardium with p = 0.665 /p = 0.186 /p = 0.436. CONCLUSION: Compared to established core biopsy systems, the biopsy-cannula prototype offers diagnostically equivalent biopsy specimen quality in an in-vitro setting in bovine liver, kidney and myocardium.

Olfactory dysfunction in Wegener's granulomatosis.

Necrotizing granulomatous inflammation of the upper respiratory tract is one of the hallmarks of Wegener's granulomatosis (WG), which may explain the reason for olfactory dysfunction in WG. However, a systematic analysis using modem olfactory testing tools has not been performed and potential causes of dysfunction at different levels of olfactory information processing remain obscure so far. In this study a group of 76 WG-patients was examined with sniffin'sticks screening 12, odour threshold (T)/discrimination (D)/identification (I) TDI-score, active anterior rhinomanometry and a standardized questionnaire for olfactory function. WG-patients were aware of their olfactory dysfunction, as proven by psychophysiological test results. An altered olfactory function was significantly correlated to local administration of mupirocin and to the time interval between first diagnosis and study entry. None of the other variables had a statistical significant effect on the olfactory dysfunction.

Development of a permanently controllable rotating biopsy device, Part I: theoretical considerations and in-vitro results for five different prototypes.

PURPOSE: To develop different prototypes of permanently controllable rotating biopsy devices with determination of the most efficient prototype in biopsies in bovine myocardium. MATERIALS AND METHODS: Five different prototypes of 18-gauge rotating biopsy devices were designed and constructed, four (1 - 4) with various drill-like cutting edges and one (5) cannula type with a lancet-like helically bent cutting edge. Using bovine myocardium as the biopsy tissue, n = 100 specimens per prototype were obtained, and a quantitative analysis including tissue fragmentation, length in mm and weight in mg was carried out. For statistical analysis, the chi-square test for tissue fragmentation and Kruskal-Wallis test for the parameters length and weight were calculated. RESULTS: Prototype 5 showed the highest rate of extraction of one-fragment specimens in n = 66 cases and the lowest rate of failure to obtain tissue in n = 11 cases. The mean length/weight were 4.15 mm/ 3.91 mg for prototype 1, 1.80 mm/ 1.66 mg for prototype 2, 4.61 mm/ 3.28 mg for prototype 3, 5.20 mm/ 3.74 mg for prototype 4, and 9.57 mm/ 6.97 mg for prototype 5. In all three categories, prototype 5 was significantly superior to the prototypes 1 - 4 with p < 0.001. CONCLUSION: The cannula type with a lancet-like helically bent cutting edge proved to be the most efficient prototype and may now be tested competitively against established automated biopsy devices in vitro.

The intermediate effect and the diagnostic accuracy in clinical case recall of students and experts in dental medicine.

INTRODUCTION: The extensive knowledge of experts facilitates the solving of domain-specific problems. In general, this is due to the fact that experts recall more detailed information than do novices or even advanced students. However, if physicians of different expertise levels are asked to write down the details of a given case, advanced medical students recall more information than experts. This phenomenon was called the 'intermediate effect' and is considered to be a specific feature of medical expertise. The aim of the here presented study was to examine this observation in the domain of dental medicine. MATERIALS AND METHODS: Sixty-one students and 20 specialised dentists participated in this study. Three clinical case descriptions were presented and afterwards the participants were told to write down all concrete information they remembered. Finally, they had to come up with a diagnosis. Interrater agreement, diagnostic accuracy and the recall explanation protocols were analysed statistically in comparison to state-of-the-art (canonical) explanations of the clinical cases. RESULTS: The mean interrater agreement was 96.2 +/- 3.37%. It was shown statistically that the more experienced the participants, the more accurate their diagnoses were (P < 0.001). The statistical analysis using the Games-Howell test demonstrated significant more written recall of the 5th-year students compared with 3rd- and 4th-year students and experts (P < 0.05). CONCLUSION: The results of this study suggest the existence of the intermediate effect in clinical case recall in dental medicine and thereby corroborate its importance and general applicability for different medical domains.

Influence of anaesthesia resident training on the duration of three common surgical operations.

We investigated the influence of resident training on anaesthesia workflow of three standard procedures--laparoscopic cholecystectomy, diagnostic gynaecological laparoscopy and transurethral prostate gland resection (TURP)--comparing 259 non-emergency resident vs 341 consultant cases from 20 German hospitals. Each hospital provided 10 random cases for each procedure, yielding 600 cases for analysis. Standard time intervals as documented in the hospital information system were: 'Case Time' (the time from the start of anaesthesia induction to discharge of the patient to the recovery area) and 'Anaesthesia Control Time' (which was the Case Time minus the time from the start of surgery to the end of surgical closure). Case Time was significantly shorter for consultants in all three procedures (p < 0.05, analysis of variance) and Anaesthesia Control Time shorter for consultants only in gynaecological laparoscopy and TURP. Patient comorbidity, patient age and geographical location of the hospital were not influential factors in the analysis of variance. We conclude that resident training significantly increases duration of elective operative times.

The role of pathophysiological explanations in clinical case representations of dental students and experts.

INTRODUCTION: Teaching of biomedical knowledge lays the foundations for the understanding and treatment of diseases. However, the representation of pathophysiological explanations in the management of clinical cases differs for various levels of medical expertise and different theories have been proposed to explain this phenomenon. The present study investigated for the first time how biomedical knowledge is used in clinical reasoning in dental medicine. MATERIALS AND METHODS: In an experimental study 20 experts in the field of Periodontology and 61 students of different levels of training produced written pathophysiological explanations after having studied three different clinical cases. By comparing the written protocols to a visualised expert-made 'canonical' explanation the concepts used in the pathophysiological explanation were counted and classified as well as the links between concepts. RESULTS: The statistical analysis by MANOVA showed significant differences between third- and fourth-year students, students of intermediate expertise level (fifth-year) and experts for various parameters qualifying concepts or links of the written pathophysiological explanations. The participants of intermediate expertise level produced a high rate of concepts and links; however, characteristic findings for knowledge encapsulation in the different levels of expertise were not evident. The analysis showed that the design of the clinical cases and of the canonical explanations significantly influenced the outcomes. CONCLUSION: The present study demonstrated the pathophysiological representations of clinical cases in dental students and experts to be different from other medical disciplines. It could be assumed that this observation is based on different contents for teaching of practical skills and diagnostic procedures in dental compared with medical education.