[Organoids for the advancement of intraoperative diagnostic procedures]. / Organoide zur Weiterentwicklung der intraoperativen Diagnostik.

In the context of cancer surgery, there is always a trade-off between oncological safety and preservation of function. This is especially true in pelvic surgery due to the close relationship to the pelvic floor muscles, blood supply and nerves. Currently, risk models, preoperative imaging, the surgeon's assessment, and the intraoperative frozen section serve as the basis for decision-making. New imaging techniques and standardization in frozen section have significantly improved this in recent years. However, limitations remain due to time delays as well as more difficult correct anatomical assignment in the follow-up. Alternative intraoperative techniques may overcome this limitation in the future. Patient-derived organoids have emerged as an important new research vehicle in recent years. They are based on tumor stem cells that, under special culture conditions, form three-dimensional replicas of the original tissue. This makes them ideally suited for testing individual system therapies but also as a validation technique for new intraoperative diagnostic procedures. The Research Training Group 2543/I, which is funded by the German Research Foundation, is researching the potential of new diagnostic methods in an interdisciplinary team regarding validation in addition to intraoperative frozen sections.

Antibodies to flagellin indicate reactivity to bacterial antigens in IBS patients.

One of the several possible causes of irritable bowel syndrome (IBS) is thought to be low-grade mucosal inflammation. Flagellin, the primary structural component of bacterial flagellae, was shown in inflammatory bowel disease patients to activate the innate and adaptive immunity. It has not yet been conclusively established if IBS patients show reactivity to luminal antigens. In 266 patients [112 IBS, 61 Crohn's disease (CD), 50 ulcerative colitis (UC) and 43 healthy controls (HC)], we measured antibodies to flagellin (FAB, types A4-Fla2 and Fla-X), anti-Saccharomyces cerevisiae antibodies (ASCA) (both ELISA), antipancreas antibodies (PAB) and perinuclear antineutrophil cytoplasmatic antibodies (p-ANCA) (both IF). All IBS patients had normal fecal calprotectin (mean 21 microg mL(-1), SD 6.6) and fulfilled the ROME II criteria. Frequencies of antibodies in patients with IBS, CD, UC and HC, respectively, are as follows (in per cent): antibodies against A4-Fla2: 29/48/8/7; antibodies against Fla-X: 26/52/10/7; ASCA: 6/59/0/2; p-ANCA: 0/10/52/0; and PAB: 0/28/0/0. Antibodies against A4-Fla2 and Fla-X were significantly more frequent in IBS patients than in HC (P = 0.004 and P = 0.009). Antibodies to A4-Fla2 and Fla-X were significantly more frequent in IBS patients with antecedent gastroenteritis compared to non-postinfectious IBS patients (P = 0.002 and P = 0.012). In contrast to ASCA, PAB and p-ANCA, antibodies against A4-Fla2 and Fla-X were found significantly more often in IBS patients, particularly in those with postinfectious IBS, compared to HC. This observation supports the concept that immune reactivity to luminal antigens has a putative role in the development of IBS, at least in a subset of patients.

In vitro differentiation of human dental follicle cells with dexamethasone and insulin.

The dental follicle is an ectomesenchymally derived connective tissue harboring precursor cells for the tooth supporting apparatus. In this study, we examined gene expression of freshly isolated human dental follicle cells during osteogenic differentiation in vitro. These plastic adherent fibroblastic cells express Notch-1, nestin and vimentin. We differentiated dental follicle cells with dexamethasone or insulin-based protocols into membrane-like structures containing mineralizing foci. An analysis of mineralized tissue with atomic force microscopy illustrated a bone and cementum-like structure. A real-time RT-PCR analysis was developed to investigate expression of typical osteoblast or cementoblast related genes during differentiation. Gene expressions of osteocalcin (OCN), bone morphogenic protein (BMP)-2 and nestin were increased during the both differentiation approaches. Our work demonstrates differentiation of dental follicle cells with an insulin-based protocol for the first time.

Analyzing heat capacity profiles of peptide-containing membranes: cluster formation of gramicidin A.

The analysis of peptide and protein partitioning in lipid membranes is of high relevance for the understanding of biomembrane function. We used statistical thermodynamics analysis to demonstrate the effect of peptide mixing behavior on heat capacity profiles of lipid membranes with the aim to predict peptide aggregation from c(P)-profiles. This analysis was applied to interpret calorimetric data on the interaction of the antibiotic peptide gramicidin A with lipid membranes. The shape of the heat capacity profiles was found to be consistent with peptide clustering in both gel and fluid phase. Applying atomic force microscopy, we found gramicidin A aggregates and established a close link between thermodynamics data and microscopic imaging. On the basis of these findings we described the effect of proteins on local fluctuations. It is shown that the elastic properties of the membrane are influenced in the peptide environment.

Dynamic interactions of p53 with DNA in solution by time-lapse atomic force microscopy.

Dynamic interactions of the tumor suppressor protein p53 with a DNA fragment containing a p53-specific recognition sequence were directly observed by time-lapse tapping mode atomic force microscopy (AFM) in liquid. The divalent cation Mg(2+) was used to loosely attach both DNA and p53 to a mica surface so they could be imaged by the AFM while interacting with each other. Various interactions of p53 with DNA were observed, including dissociation/re-association, sliding and possibly direct binding to the specific sequence. Two modes of target recognition of p53 were detected: (a) direct binding, and (b) initial non-specific binding with subsequent translocation by one-dimensional diffusion of the protein along the DNA to the specific site.

Common hand fractures in family practice.

This article describes the office treatment for five common hand fractures. In addition to examination findings and treatment options, guidelines are provided for those complications that necessitate orthopedic referral. The five fractures reviewed include mallet finger fractures, distal phalangeal fractures, fractures from volar plate injuries to the middle phalanx, dorsal dislocations of the proximal interphalangeal joint, and fractures of the fifth metacarpal.

Joint and soft-tissue arthrocentesis.

Diagnostic arthrocentesis and therapeutic joint and soft tissue injections are important components in the treatment of musculoskeletal complaints for the primary care physician. Proper knowledge of joint architecture anatomic landmarks, indications, contraindications, and complications of injection will enable the physician to provide the patient with a maximum of benefit with a minimum of risk.

Management of common finger injuries.

Family physicians can manage most finger injuries, including uncomplicated fractures, proximal interphalangeal joint dislocations, closed tendon injuries and ligament sprains. Finger injuries that can cause long-term morbidity may present as minor sprains. Diagnosis requires a thorough history, systematic examination and radiographic evaluation.

Seriators' and nonseriators' comprehension of comparative adjective forms.

The relationship between comprehension of relational adjective forms and seriation ability was assessed for 60 children aged 4-6. Three groups, operational seriators, intuitive seriators, and nonseriators, were given a test measuring comprehension of affirmative and negative comparative and equative forms. Results indicated that operationals understood more forms than intuitives and that intuitives comprehended more than nonseriators. When age differences between groups were minimized, the latter but not the former difference was preserved. This suggests that significant growth in linguistic comprehension accompanies the emergence of the ability to order objects by size. Analysis of errors indicated that nonseriators interpreted statements dichotomously and ignored the standard more than seriators. Findings help to clarify the relationship between linguistic and cognitive development for parallel underlying structures.

Evaluation of netilmicin susceptibility discs using bacteria with known aminoglycoside resistance patterns: correlation of in vitro and in vivo test results.

Data obtained with 30 micrograms netilmicin discs on Mueller-Hinton agar have been compared to MIC values obtained in Mueller-Hinton broth. Regression analysis was used to determine susceptibility cutoff points for Pseudomonas and non-Pseudomonas gram-negatives. The utility of these cutoff points for the determination of netilmicin sensitivity was evaluated in tests with 1405 clinical isolates. These tests employed 897 sensitive isolates and 508 strains with known aminoglycoside resistance patterns. Netilmicin was shown to be active against sensitive isolates and those strains with resistance patterns corresponding to the presence of: ANT(2"), ANT(2")+AAC(6'), ANT(4'), APH(2")+AAC(6'), APH(3')-IV and AAC(3)-I modifying enzymes. PD50 values obtained in experimental mouse infection studies with gentamicin, tobramycin and amikacin as well as netilmicin confirmed the excellent activity of netilmicin against strains with the above-mentioned resistance patterns. The good correlation between disc sensitivity test results and MIC and PD50 values suggest that a 30 micrograms netilmicin disc can be used to predict the netilmicin susceptibility of clinical isolates.

Biohazard potential: recovery of infectious virus from the liquid nitrogen of a virus repository.

Flame-sealed glass ampules containing vesicular stomatitis (VSV) were submerged in a liquid nitrogen (LN2) refrigerator for storage. Onseveral occasions cracked or shattered ampules were discovered upon removal from the refrigerator. Subsequently, VSV was recovered from the LN2 of the virus repository indicating a source of potential danger to those employing glass ampules submerged in LN2 for preservation of pathogenic organisms.