[Promoting young academics in anesthesiology: factors for an attractive internship]. / Nachwuchsförderung in der Anästhesiologie: attraktive Gestaltung der Famulatur.

BACKGROUND: Practical experiences in clinical traineeships can shape the later specialty choice of medical students. KEY QUESTION: The following study aimed to find factors in anesthesiological clinical traineeship that encourage students to specialize in the field. MATERIAL AND METHODS: As part of a nationwide online survey conducted by the working group for education of the German Association for Orthopedics and Trauma Surgery (Deutsche Gesellschaft für Orthopädie und Unfallchirurgie, DGOU), study participants (n = 479) answered questions about their minimum 4­week traineeship in anesthesiology. The information on items was analyzed in six content categories: 1) integration into the team, 2) acquisition of skills, 3) teachers, 4) quality of teaching, 5) structure of teaching and 6) satisfaction with the clinical internship. The respondents were subdivided into 4 groups by answering the question "Could you imagine an elective in anesthesiology during the final year (PJ)" with "Yes, I have made this decision after the clinical traineeship" (JdF, n = 212, 44%), "No I have decided against an elective during the final year after the traineeship" (NdF, n = 56, 12%), "Yes I have decided for an elective in anesthesiology before the internship" (JvF Yes: n = 144, 30%) and "No, I have decided against an elective in anesthesiology before the internship" (NvF: n = 67, 14%). Answers of the participants regarding the six content categories were compared between the four groups. RESULTS: The survey reached all medical faculties in Germany and included participants with an average age of 25.8 years and a balanced gender ratio. There were significant differences between satisfied and dissatisfied students in all four subgroups. Of the 479 respondents, 211 (44%) were already set regarding their decision of choosing anesthesiology as an elective during the final year before the clinical traineeship. Of the respondents 268 (56%) were influenced by the internship, 212 (44%) of them positively. In total, 81% of the trainees rated the internship as "satisfying". Students who were satisfied with the overall internship and who spoke in favor of the PJ elective in anesthesiology differed significantly from the other groups in the categories of team integration, skills acquisition, structure and quality of teaching. The teaching of practical skills and specialist knowledge as well as the integration into diagnostics and treatment planning promoted the recruitment of young people. DISCUSSION: The positively evaluated anesthesiology internship promotes later specialty choice, with quality and structure of the teaching affecting student satisfaction. Trainees who were attracted by anesthesiology gave better overall ratings and acquired more skills during the course of the internship. In order to win aspiring doctors for anesthesiology, the medical team has to integrate trainees well and support the acquisition of practical skills and specialist knowledge. In addition, didactics and practical relevance should be given high priority.

[Informed consent for surgery: clearly regulated by the patient rights law-significant uncertainty among medical students : Legal analysis and inventory of over 2500 medical students in Berlin as part of the Progress Test Medicine]. / Chirurgische Aufklärung: Klar geregelt durch das Patientenrechtegesetz ­ deutliche Unsicherheit bei Medizinstudierenden : Rechtsanalyse und Bestandsaufnahme bei über 2500 Berliner Medizinstudierenden im Rahmen des Progress Test Medizin.

BACKGROUND: Obtaining informed consent is a challenging task and is part of the educational objectives in the German NKLM. Teaching formats are inconsistent and time-consuming, with little emphasis on legal aspects, although they have moved into the focus of attention since the implementation of patient rights laws and play an important role in legal proceedings. OBJECTIVES: The aim of this study was the evaluation of medical students' knowledge about the legal aspects of obtaining informed consent. A legal analysis was performed, and the patient rights laws were reviewed with reference to implications for undergraduate medical education. MATERIALS AND METHODS: After the analysis of laws and jurisdiction, multiple-choice questions regarding the legal aspects of obtaining informed consent were created and placed in the Progress Test Medicine (PTM). A statistical analysis of the results of Berlin medical students was performed descriptively. RESULTS: The answers of 2625 (winter semester 2018/19) and 2409 (summer semester 2019) medical students in Berlin were analyzed. The rate of students who answered the questions about the procedures requiring informed consent and adequate time for consideration increased over time but did not reach comparable values to all PTM questions. Questions about required content were answered correctly by 30 to 60% of the students, regardless of their level of training; we did not see an increase along with the time of study. CONCLUSION: In our study, we were able to show that medical students of all educational levels show tentativeness when it comes to the legal aspects of obtaining informed consent. Yet, the legal framework offers room for new teaching formats like "Co-Action", introduced in this paper for the first time, where students acquire informed consent while being supervised by the medical doctor in charge.

[Ulceroglandular tularemia after contact with a wild boar : Risk of infection for medical personnel by aerosol inhalation during lymph node resection]. / Ulzeroglanduläre Tularämie nach Kontakt mit Wildschwein : Infektionsrisiko für medizinisches Personal durch Inhalation von Aerosolen bei Lymphknotenresektion.

This article presents a case of ulceroglandular tularemia with local lymph node manifestation in a hobby hunter. An adequate diagnosis and early treatment of tularemia is of crucial importance not only for the patient, as when a surgical intervention is necessary there are also substantial risks for medical personnel. In the diagnosis of tularemia, which is rare but with an increasing incidence in Germany, the anamnesis provides the most important clues. A surgical intervention should only be performed after adequate treatment and duration of treatment.

The effect of professional tooth cleaning or non-surgical periodontal therapy on oral halitosis in patients with periodontal diseases. A systematic review.

OBJECTIVE: The aim of this systematic review was to give the best available evidence on the impact of professional tooth cleaning (PTC) and scaling and root planing (SRP) on oral halitosis in patients with periodontal diseases. MATERIAL AND METHODS: Three databases were screened for relevant studies. Only randomized controlled trials (RCTs) or controlled clinical trials (CCT) were included. The primary outcome in all included studies was volatile sulphur compounds (VSC) measured by Halimeter or OralChroma and organoleptic scores as secondary outcome. Only studies investigating healthy adults except for periodontitis or gingivitis were included. The considered intervention strategies were professional tooth cleaning and non-surgical periodontal treatment. For both strategies, additional oral hygiene instructions (OHI) were possible. Two independent reviewers performed the study selection and quality assessment. SEARCH RESULTS: After abstract and title screening and subsequent full-text reading of potential papers, a placebo-controlled RCT could not be found. However, eight studies or particular arms used PTC or SRP as sole interventions and were included in this review. All trials or study arms included showed a positive effect on VSC levels or organoleptic scores after intervention. CONCLUSIONS: Based on best available evidence, PTC and SRP in combination with oral hygiene instructions reduced VSC values in patients with oral halitosis and/or periodontal diseases, independent of tongue cleaning and the use of mouth rinses.

In vitro effects of particulate bone substitute materials on the resorption activity of human osteoclasts.

Much research has been done on bone cells, but only a few studies deal with biomaterial-induced effects on human osteoclasts, which may take on an important role in the successful regeneration of bone. In order to highlight such effects, human peripheral blood mononuclear cells (PBMCs) were extracted from venous blood, differentiated to osteoclasts and then cultured in, the presence of five particulate hydroxyapatite (HA)/ß-tricalcium phosphate (TCP) biomaterials, on bovine bone slices and glass cover slips. The biomaterials, AlgOSS 50/50 (50 % HA/50 % TCP), AlgOSS 20/80 (20 % HA/80 % TCP), Algipore (98 % HA), Cerasorb (100 % TCP) and Bio-Oss (100 % HA) were chosen to assess their influence on cell morphology and numbers. Light microscopic evaluation was performed during ongoing cell culture. After 21 d of cultivation, the biomaterial-induced effects on osteoclastic resorption of the bone slices were evaluated by scanning electron microscopy (SEM). Osteoclast-like cells were identified by TRAP staining. All five biomaterials showed larger area fractions of resorbed bone than the control (5.6 ± 6.8 %), as measured on SEM images. The purely hydroxyapatite-based Algipore (9.8 ± 9.7 %) and Bio-Oss (7.9 ± 8.8 %) showed significantly elevated area fraction rates (p ≤ 0.05) of bone resorption. Light microscope evaluation revealed a significant, but inhibiting effect of Cerasorb (p = 0.05). These data indicated that introducing of small biomaterial hydroxyapatite particles may have improved the performance of bone substitute materials.

Impaired fracture healing with high non-union rates remains irreversible after traumatic brain injury in leptin-deficient mice.

Patients with traumatic brain injury (TBI) and long-bone fractures can show increased callus formation. This effect has already been reproduced in wild-type (wt) mice. However, the mechanisms remain poorly understood. Leptin is significantly increased following TBI, while its role in bone healing remains unclear. The aim of this study was to evaluate fracture healing in leptin-deficient ob/ob mice and to measure any possible impact of TBI on callus formation. 138 female, 12 weeks old, ob/ob mice were divided into four groups: Control, fracture, TBI and combined trauma. Osteotomies were stabilized with an external fixator; TBI was induced with Controlled Cortical Impact Injury. Callus bridging was weekly evaluated with in vivo micro-CT. Biomechanical testing was performed ex vivo. Micro-CT showed high non-union rates after three and four weeks in the fracture and combined trauma group. No differences were observed in callus volume, density and biomechanical properties at any time point. This study shows that bony bridging is impaired in the present leptin-deficient trauma model. Furthermore, the phenomenon of increased callus formation after TBI could not be reproduced in ob/ob mice, as in wt mice. Our findings suggest that the increased callus formation after TBI may be dependent on leptin signaling.

A principal components analysis: how pneumatization and edentulism contribute to maxillary atrophy.

OBJECTIVE: The aim of this retrospective cohort study was to investigate the role of sinus pneumatization and residual ridge resorption in maxillary bone loss in 400 computed tomography (CT) scans. MATERIALS AND METHODS: In 200 dentate and 200 edentulous patients, both sinuses were analysed using CT scans. The image analysis sequence consisted of manual placement of 24 reference points, followed by automated segmentation and final manual refinement. Finally, a principal components analysis was performed. RESULTS: A total of 788 sinuses were included into the analysis. The edentulous group (98 female: 67.77 ± 11.28 years, 99 male: 65.22 ± 9.87) was significantly older than the group with teeth (99 female: 46.89 ± 16.77 years, 96 male: 49.74 ± 16.2). Female and male patients did not differ regarding age. The alveolar height differed significantly between the groups (edentulous: 7.1 ± 4.3 mm, with teeth: 9.7 ± 4.1 mm), but not between gender (female: 8.3 ± 4.4 mm, male: 8.5 ± 4.4 mm). Principal components analysis was able to explain 90% of the variation in sinus morphology. CONCLUSIONS: Prolonged edentulism in the maxillary molar region leads to centripetal and to minor degrees centrifugal ridge resorption. Minor pneumatization occurs in the sinus walls, but the sinus depth underlies the anatomical variation independent of dentition.

Effects of neratinib and combination with irradiation and chemotherapy in head and neck cancer cells.

OBJECTIVE: Prognosis of patients with head and neck squamous cell carcinoma (HNSCC) is still poor. Novel therapeutic approaches are of great interest to improve the effects of radiochemotherapy. We evaluated the effects of tyrosine kinase inhibitor neratinib on HNSCC cell lines CAL27, SCC25 and FaDu as a single agent and in combination with irradiation and chemotherapy. METHODS: Effects of neratinib were evaluated in HNSCC cell lines CAL27, SCC25 and FaDu. Effect on cell viability of neratinib and combination with cisplatin and irradiation was measured using CCK-8 assays and clonogenic assays. Western blot analysis was performed to distinguish the effect on epithelial growth factor receptor and HER2 expression. Apoptosis was evaluated by flow cytometry analysis. RESULTS: Growth inhibition was achieved in all cell lines, whereas combination of cisplatin and neratinib showed greater inhibition than each agent alone. Apoptosis was induced in all cell lines. Combination of neratinib with irradiation or cisplatin showed significantly increased apoptosis. In clonogenic assays, significant growth inhibition was observed in all investigated cell lines. CONCLUSION: Neratinib, as a single agent or in combination with chemo-irradiation, may be a promising treatment option for patients with head and neck cancer.

Osteoarthritis in morbidly obese children and adolescents, an age-matched controlled study.

PURPOSE: Main objective of this study was to investigate the association of pain and early cartilage lesions in morbidly obese children and adolescents. METHODS: A total of 57 subjects were included in the study. Morbidly obese patients (n = 39) were subdivided into two groups: Group A: (11 males and 9 females, 14.2 ± 2.7 years) with permanent knee pain; and Group B: (10 males and 9 females, 14.4 ± 2.2 years) without permanent or without any knee pain. Group C (8 males and 10 females, 15.0 ± 2.9 years) included age-matched children and adolescents of normal weight. MRI examinations were performed in all subjects, and an extensive analysis of the images was conducted according to the condition of the cartilage surface and the meniscus. Patients' subjective health was assessed by means of four well-known knee scores (IKDC, KOOS, Tegner/Lysholm, and VAS). Nonparametric Jonckheere-Terpstra test was used to test the trend of the natural order between the three groups. RESULTS: In 38 of 39 morbidly obese children and adolescents, in at least one region of the knee, a marked cartilage lesion could be shown by MRI. Group A showed significantly (p < 0.001) more cartilage lesions (mean 3.7) compared to Group B (mean 2.8) and Group C (mean 0.8). IKDC, and all the KOOS subunits, showed significantly (p < 0.001, p Bonferroni < 0.001) increasing scores from Group A to B to C, in addition to KOOS symptoms. CONCLUSIONS: Morbid obesity causes early lesions of the knee cartilage, even in young patients. Significantly, more patients with reported pain show more severe damages.

[Interpersonal competence in orthopedics and traumatology : Why technical and procedural skills alone are not sufficient]. / Interpersonelle Kompetenz in Orthopädie und Unfallchirurgie : Warum technische und prozedurale Fähigkeiten alleine nicht ausreichen.

Patient safety has increasingly gained significance as criterion which clinics and doctors will be measured against in terms of ethics and finances. The "human factor" moved into focus regarding the question of how to reduce treatment errors in clinical daily routine. Nevertheless, systematic mediation of interpersonal competences only plays a minor role in the catalogue of requirements for medical specialization and professional training. This is the case not only in orthopedics and traumatology, but in other medical fields as well. At the insistence of DGOU and in cooperation with Lufthansa Flight Training, a training model was initiated, comparable to training models used in aviation. In aviation, apart from the training of procedural and technical abilities, regular soft skills training has become standard in the training of all Lufthansa staff. Several studies confirm that by improving communication, interaction, and teamwork skills not only a reduction of intolerable incidents is observed, but also a positive economic effect. Interpersonal competences should be firmly anchored in orthopedics and traumatology and thus be implemented as third post in specialist training.

The effect of cilengitide in combination with irradiation and chemotherapy in head and neck squamous cell carcinoma cell lines.

BACKGROUND: Integrins are highly attractive targets in oncology due to their involvement in angiogenesis in a wide spectrum of cancer entities. Among several integrin inhibitors under clinical evaluation, cilengitide is the most promising compound. However, little is known about the cellular processes induced during cilengitide therapy in combination with irradiation and cisplatin in head and neck squamous cell carcinoma (HNSCC). MATERIALS AND METHODS: The cytostatic effect of cilengitide was assessed by proliferation assay in the three HNSCC cell lines SCC25, FaDu and CAL27. Combination experiments with cisplatin and irradiation were performed. Possible synergistic effects were calculated in combination index (CI) analyses. Colony forming inhibition was investigated in clonogenic assays. Real-time PCR arrays were used to evaluate target protein gene expression patterns. Flow cytometry was used to detect apoptosis. RESULTS: Used alone, cilengitide has only minor cytotoxic effects in HNSCC cell lines. However, combination with cisplatin resulted in synergistic growth inhibition in all three cell lines. Irradiation showed synergism in short-term experiments and in colony forming assays, an additive effect was detected. Real-time PCR assay detected downregulation of the antiapoptotic protein Bcl-2 after exposure of cells to cilengitide. CONCLUSION: Cilengitide in combination with cisplatin and irradiation may be a feasible option for the treatment of patients with head and neck cancer. However, further investigations are required to understand the exact mechanism that leads to synergistic cytotoxicity.

The effect of resveratrol in combination with irradiation and chemotherapy: study using Merkel cell carcinoma cell lines.

BACKGROUND AND PURPOSE: Merkel cell carcinoma (MCC) is a rare, but highly malignant tumor of the skin. In case of systemic disease, possible therapeutic options include irradiation or chemotherapy. The aim of this study was to evaluate whether the flavonoid resveratrol enhances the effect of radiotherapy or chemotherapy in MCC cell lines. MATERIALS AND METHODS: The two MCC cell lines MCC13 and MCC26 were treated with increasing doses of resveratrol. Combination experiments were conducted with cisplatin and etoposide. Colony forming assays were performed after sequential irradiation with 1, 2, 3, 4, 6, and 8 Gy and apoptosis was assessed with flow cytometry. Expression of cancer drug targets was analyzed by real-time PCR array. RESULTS: Resveratrol is cytotoxic in MCC cell lines. Cell growth is inhibited by induction of apoptosis. The combination with cisplatin and etoposide resulted in a partially synergistic inhibition of cell proliferation. Resveratrol and irradiation led to a synergistic reduction in colony formation compared to irradiation alone. Evaluation of gene expression did not show significant difference between the cell lines. CONCLUSION: Due to its radiosensitizing effect, resveratrol seems to be a promising agent in combination with radiation therapy. The amount of chemosensitizing depends on the cell lines tested.

Sequential cervical length screening in pregnancies after loop excision of the transformation zone conisation: a retrospective analysis.

OBJECTIVE: To review our experience with a screening programme that included four sequential cervical length (CL) measurements from 16 to 22( ) weeks of gestation. DESIGN: Historical cohort study. SETTING: Tertiary-care centre in a university hospital. POPULATION: There were 312 singleton pregnancies in 321 women with a previous large loop excision of the transformation zone (LLETZ), and 62 pregnancies after a second-trimester miscarriage in a previous pregnancy. METHODS: The CL measurements were performed by transvaginal ultrasound at 16, 18, 20, and 22 completed weeks of gestation. MAIN OUTCOME MEASURES: Early preterm delivery before 34 completed weeks of gestation. RESULTS: Early preterm delivery was found in 7.4%. The CL at 16 completed weeks of gestation was smaller in the LLETZ group (36 mm, interquartile range 30-40 mm) compared with the control group (38 mm, interquartile range 32-42 mm; P = 0.040). For the analysis of risk factors for early preterm delivery after LLETZ, only cases with a complete data set were included (n = 145). In a multivariate analysis, two parameters remained significantly predictive, with CL at 16 completed weeks of gestation being the most significant measure (P < 0.001, OR 0.90, 95% CI 0.83-0.98), followed by conception using IVF treatment (P = 0.031, OR 0.64, 95% CI 1.54-34.80). CONCLUSIONS: Even as early as 16 weeks of gestation, women with early preterm delivery reveal a significantly lower CL than those without. Dynamics in the CL do not add to this information.

Dehydroepiandrosterone in women with premature ovarian failure and Hashimoto's thyroiditis.

We evaluated dehydroepiandrosterone sulfate (DHEAS) levels in premature ovarian failure (POF) patients with and without Hashimoto's thyroiditis, and the impact of DHEA supplementation on thyroid autoantibodies. In a retrospective case series, we included 67 women with spontaneous POF who received estrogen/gestagen replacement with or without DHEA (30 mg/day) for 3 months. Women who were seropositive for thyroglobulin antibodies and/or thyroperoxidase autoantibodies (n = 30) revealed lower pretherapeutic DHEAS levels (1.2 µg/ml, range 0.4-2.9 µg/ml vs. 1.9 µg/ml, range 0.2-3.9 µg/ml; p < 0.001). DHEAS showed an inverse correlation with both thyroglobulin antibodies (r = -0.426, p < 0.001) and thyroperoxidase autoantibodies (r = -0.362, p = 0.002). When treated with additional DHEA, significant decreases were found for thyroperoxidase autoantibodies (median 85.0 IU/ml, range 41-600 IU/ml vs. median 51.0 IU/ml, range 20-589 IU/ml; p = 0.005) but not for thyroglobulin antibodies.

Prenatal sonography can predict degree of placental invasion.

OBJECTIVE: To evaluate whether the maximum degree of placental invasion (placenta accreta, increta or percreta) can be predicted with ultrasound imaging, using criteria developed in our department. METHODS: This was a retrospective study of all 232 patients at risk for placental invasion who were part of a routine screening program for placental invasion from January 2001 to January 2011. The whole placenta was scanned in a systematic manner using both gray-scale ultrasound and color-flow mapping. Sonographic findings were compared with the clinical outcome during and after delivery and the histomorphological examination of the placenta. RESULTS: Placental invasion was suspected by ultrasound in 40 (17.2%) patients and was clinically/histopathologically confirmed in a total of 35 (15.1%) patients. The sensitivity, specificity and positive and negative predictive values of ultrasound for placental invasion were 91.4% (95% CI, 77.6-97.0%), 95.9% (95% CI, 92.2-97.9%), 80.0% (95% CI, 65.2-89.5%) and 98.4% (95% CI, 95.5-99.5%), respectively. No case of placenta increta (n = 7) or percreta (n = 17) was diagnosed as showing normal placentation or placenta accreta on ultrasound, giving an overall accuracy for the differentiation between normal placentation/placenta accreta and placenta increta/percreta of 100%. CONCLUSION: Our data suggest that prediction of the degree of placental invasion is possible using prenatal ultrasound, with high overall accuracy.

Are implants more reliable than severely compromised endodontically treated teeth as abutments for zirconia-based FPDs? : In vitro results of long-term preclinical load simulation.

OBJECTIVES: The aim was to study the impact of the defect size of endodontically treated incisors compared to dental implants as abutments on the survival of zirconia two-unit anterior cantilever-fixed partial dentures (2U-FPDs) during 10-year simulation. MATERIALS AND METHODS: Human maxillary central incisors were endodontically treated and divided into three groups (n = 24): I, access cavities rebuilt with composite core; II, teeth decoronated and restored with composite; and III as II supported by fiber posts. In group IV, implants with individual zirconia abutments were used. Specimens were restored with zirconia 2U-FPDs and exposed to two sequences of thermal cycling and mechanical loading. STATISTICS: Kaplan-Meier; log-rank tests. RESULTS: During TCML in group I two tooth fractures and two debondings with chipping were found. Solely chippings occurred in groups II (2×), IV (2×), and III (1×). No significant different survival was found for the different abutments (p = 0.085) or FPDs (p = 0.526). Load capability differed significantly between groups I (176 N) and III (670 N), and III and IV (324 N) (p < 0.024). CONCLUSION: Within the limitations of an in vitro study, it can be concluded that zirconia-framework 2U-FPDs on decoronated teeth with/without post showed comparable in vitro reliability as restorations on implants. The results indicated that restorations on teeth with only access cavity perform worse in survival and linear loading. CLINICAL RELEVANCE: Even severe defects do not justify per se a replacement of this particular tooth by a dental implant from load capability point of view.

Implementation of a digital health module for undergraduate medical students: A comparative study on knowledge and attitudes.

BACKGROUND: Digital competencies are more and more required in everyday work, and training future healthcare professionals in digital health is highly important. OBJECTIVE: Aim of this study was to assess medical students' gain of knowledge by participation in a teaching module "Digital Health", and to evaluate their attitudes towards digital health and its role in medical education. METHODS: Students of the module were asked to complete a questionnaire and a multiple-choice-test before and after completing the classes. Students of the same educational level in different modules served as reference group. RESULTS: 34 students took part (n= 17 "Digital Health group"; n= 17 "reference group"). There was no significant difference in pre-existing knowledge between the groups. After having completed the module, participants reached significantly higher scores, compared to their preexisting knowledge (p< 0.05) and the reference group (p< 0.05). Most students found that digital medicine is not sufficiently represented in undergraduate medical education, but will influence everyday work of physicians in the next five years. CONCLUSIONS: Students showed a high awareness for the impact of digital health on physicians' work. The results suggest that the format can sufficiently transfer knowledge about digital health. Teaching of digital knowledge and competencies should be firmly implemented into medical education to form digitally competent future doctors.

Risk factors for postoperative bleeding after thyroid surgery.

BACKGROUND: Postoperative bleeding after thyroid surgery is a feared and life-threatening complication. The aim of the study was to identify risk factors for postoperative bleeding, with special emphasis on the impact of the individual surgeon and the time to diagnosis of the complication. METHODS: Data on consecutive thyroid operations were collected prospectively in a database over 30 years and analysed retrospectively for potential risk factors for postoperative bleeding. RESULTS: There were 30,142 operations and postoperative bleeding occurred in 519 patients (1·7 per cent). Risk factors identified were older age (odds ratio (OR) 1·03 per year), male sex (OR 1·64), extent of resection (OR up to 1·41), bilateral procedure (OR 1·99) and operation for recurrent disease (OR 1·54). The risk of complications among individual surgeons differed by up to sevenfold. Postoperative bleeding occurred in 336 (80·6 per cent) of 417 patients within the first 6 h after surgery. Postoperative bleeding was diagnosed after 24 h in ten patients (2·4 per cent), all of whom had bilateral procedures. Nine patients required urgent tracheostomy. Three patients died, giving a mortality rate of 0·01 per cent overall and 0·6 per cent among patients who had surgery for postoperative bleeding. CONCLUSION: Observation for up to 24 h is recommended for the majority of patients undergoing bilateral thyroid surgery in an endemic goitre area. Same-day discharge is feasible in selected patients, especially after a unilateral procedure. Quality improvement by continuous outcome monitoring and retraining of individual surgeons is suggested.

Morphological clues to wet granular pile stability.

When a granular material such as sand is mixed with a certain amount of liquid, the surface tension of the latter bestows considerable stiffness to the material, which enables, for example, sand castles to be sculpted. The geometry of the liquid interface within the granular pile is of extraordinary complexity and strongly varies with the liquid content. Surprisingly, the mechanical properties of the pile are largely independent of the amount of liquid over a wide range. We resolve this puzzle with the help of X-ray microtomography, showing that the remarkable insensitivity of the mechanical properties to the liquid content is due to the particular organization of the liquid in the pile into open structures. For spherical grains, a simple geometric rule is established, which relates the macroscopic properties to the internal liquid morphologies. We present evidence that this concept is also valid for systems with non-spherical grains. Hence, our results provide new insight towards understanding the complex physics of a large variety of wet granular systems including land slides, as well as mixing and agglomeration problems.

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.