High-definition imaging in spinal neuroendoscopy.

BACKGROUND: Spinal endoscopy is still under controversial discussion. An often acclaimed critic is the poor endoscopic image quality in comparison with the microscope. Since high-definition digital cameras have recently been introduced into spinal neuroendoscopy, the aim of the current study is to examine whether superior image quality has a relevant impact on intraoperativen orientation. MATERIAL AND METHODS: A lumbar endoscopic discectomy was recorded simultaneously in High-Definition resolution (HD) and Standard-Definition resolution (SD). 10 experienced spinal surgeons were asked to identify predefined as well as not predefined anatomic structures in HD and SD resolution. Additionally, the video quality was rated with grades from 1 ("very good") to 6 ("poor"). RESULTS: Out of 14 predefined structures an average of 7.8+/-3.3 structures (55.71%) were identified in HD, 4.4+/-3.2 structures (31.43%) in SD (p=0.03). Out of 14 not predefined anatomical structures, 5.9+/-3.6 were correctly identified in HD, 2.6+/-2.5 in SD (p=0.05). Misinterpretation of structures occurred in 1.4+/-1 cases in HD, compared to 3+/-2.2 in SD (p=0.05). Subjective impression of video quality was rated 2.2 ("good") for HD, 3.0 ("satisfactory") for SD (p=0.03). CONCLUSION: HD in endoscopic discectomy accounts for a significantly more reliable identification of anatomic structures in freeze-images in comparison with standard definition images. Additionally, the subjective impression of video quality is significantly better in HD. This superior identification of structures might contribute to improve intraoperative orientation in endoscopic neurosurgery using high definition quality technology.

Morphological differences in Neisseria meningitidis pili.

Disease and carrier isolates of Neisseria meningitidis were examined for their ability to adhere to human buccal epithelial cells and human cell lines and to hemagglutinate human erythrocytes, properties thought to be associated with the presence of pili. Seventy percent (7 of 10) of carrier isolates were found to be highly adherent to human buccal epithelial cells and to agglutinate human A, B, O, Rh-, and Rh+ erythrocytes. In contrast, 60% of the disease isolates adhered poorly to human buccal epithelial cells and 80% failed to agglutinate human erythrocytes. No adherence of either disease or carrier isolates was observed when several human cell lines were tested. When the meningococcal strains were examined by electron microscopy, 7 of 10 disease isolates were found to possess large bundles of aggregated pili (alpha-type pili), while 7 of 10 carrier isolates were found to have numerous unaggregated pili (beta-type pili). A monoclonal antibody against meningococcal pili and one against gonococcal pili reacted with 6 of 10 piliated carrier isolates and 4 of 10 piliated disease isolates. These results suggest that meningococci, like gonococci, possess different types of pili which differ in morphological, antigenic, and binding properties. In addition, antigenic and morphological differences between pili from carrier and disease isolates were observed as well as differences in adherence and hemagglutinating properties.