New quantitative automated model to simulate bacterial dissemination in human tissue during irrigation of contaminated wounds

This study presents a simple and cost-effective model using microparticles to simulate the bacterial distribution pattern in soft tissue after low- and high-pressure irrigation. Silica coated iron microparticles [comparable diameter (1 µm) and weight (0.8333 pg) to Staphylococcus aureus] were applied to the surface of twenty fresh human muscle tissue samples in two amputated lower legs. Particle dissemination into deep tissue layers as an undesired side effect was investigated in four measuring fields as positive control (PC) as well as after performing pulsatile high-pressure (HP, 8 measuring fields) and low-pressure flushing (LP, 8 measuring fields). Five biopsies were taken out of each measuring field to get a total number of 100 biopsies. After histological and digital image processing, the specimens were analysed, and all incomplete sections were excluded. A special detection algorithm was parameterised using the open source bioimage analysis software QuPath. The application of this detection algorithm enabled automated counting and detection of the particles with a sensitivity of 95 % compared to manual counts. Statistical analysis revealed significant differences (p < 0.05) in our three different sample groups: HP (M = 1608, S = 302), LP (M = 2176, SD = 609) and PC (M = 4011, SD = 686). While both HP and LP flushing techniques are able to reduce the number of bacteria, a higher effectiveness is shown for HP irrigation. Nevertheless, a challenge for the validity of the study is the use of dead tissue and therefore a possible negative influence of high-pressure irrigation on tissue healing and further dispersion of particles cannot be evaluated.

[Skin ulcerations due to CINCA syndrome and its successful treatment with prostaglandin E1]

Chronic infantile neurological cutaneous and articular syndrome (CINCA) is a disorder with a defect in the CIAS1 (NLRP3) gene and the altered gene product cryopyrin leads to inflammasome activation with increased IL-1beta synthesis. The activation pathway of the transcription factor NF-κB is also affected, which plays a role in angiogenesis. With respect to the angiogenesis stimulating ability of prostaglandin E₁, we treated a female patient with CINCA syndrome and conventionally non-responsive skin ulcers with prostaglandin E₁ infusions (6 μg/kg bw/24 h/5 day) followed by wound healing lasting over 3 weeks. After 1 year of periodic infusions, the skin defects were permanently closed.

[Indirect MR Arthrography of the wrist in the diagnosis of TFCC-Lesions]

PURPOSE

The objective of this prospective study was to assess the value of the indirect MR arthrography (MR-AR) of the wrist in the detection of lesions of the TFCC.

MATERIAL AND METHODS

Indirect MR-AR was performed in 45 patients (23 f/22 m) with unclear ulnar wrist pain. After i. v. injection of 0.1 mmol/kg Gd-DTPA and after a motion-phase of the wrist (15 minutes) MRI was performed in a coronal plane. We used a STIR-, a fatsaturated (fs) T1-SE and a 3D-DESS sequence. The images were evaluated by two radiologists using a consensus score. The lesions were assigned to the system of Palmer and correlated with arthroscopy.

RESULTS

Indirect MR-AR showed in 35 of 45 patients a lesion of the TFCC, but arthroscopy only revealed a defect in 32 cases. This means three false positive but no false negative assessments by MRI. Using this MRI protocol sensitivity and specificity in the detection of TFCC lesions were calculated as 100 % and 77 %. The accuracy was 93 %. Small degenerative changes of the fibres were most common (Palmer type II A). In trauma patients the ligaments usually showed tears near the insertion at the ulna (Palmer type I B). The sensitivity and specificity was 88 % and 95 % for evaluation of the scapho-lunate (SL) ligament, the accuracy was 93 %. Arthroscopy and MRI did not diagnose any rupture of the lunate-triquetral (LT) ligament.

CONCLUSION

Indirect MR-AR is a non-invasive method with a high sensitivity in the evaluation of the TFCC and associated injuries. Therefore, it is an excellent screening procedure to assess the indication for therapeutic arthroscopy.

[Identification of families with increased risk of Down's syndrome caused by translocation of chromosome 9]

Between 1976 and 1985 in the Genetic Out-patient Department Down's syndrome was found in 260 children. In 235 children it was a result of numerical aberration, in 15 children it was a result of structural aberration (unbalanced translocation in 21 chromosome)--in 7 children t(21q21q), in 6 children t(14q21q), in 2 children t(21q22q). In 3 children translocation was transmitted by one of the parents. The performed cytogenetic examination have allowed to find out the translocation carriers in these families. So there was a possibility to identify a whole series of families with an increased risk of Down's syndrome even before the birth of child with Down's syndrome. Concerned families were informed about the possibilities of prenatal diagnosis.