Hans Brun: a Swiss pioneer in the surgery of the spinal cord, brain and herniated lumbar disc

INTRODUCTION Toward the end of the nineteenth century, it was Gowers, Horsley and Macewen who first reported successful surgical procedures for the treatment of subdural extramedullary tumors. Following this, Church and Eisendrath as well as Putnam and Warren reported unsuccessful attempts to treat subpial spinal pathologies in their patients. Only at the beginning of the twentieth century did reports of successful interventions of this type accumulate. In the analysis of these case reports, the authors noticed a certain lack of accuracy about the anatomical allocations and descriptions of intra- and extramedullary spinal lesions. From this, the question of who actually carried out the pioneering works in the early twentieth century in the field of surgery of intramedullary pathologies arose. METHODS Analysis of the relevant original publications of Hans Brun and research on the poorly documented information about his life history by personally contacting contemporary relatives. RESULTS The literature analysis showed that the Swiss neurologist Otto Veraguth and surgeon Hans Brun made fundamental contributions to subpial spinal cord surgery at the very beginning of the last century that remain valid today. According to our research, Hans Brun should be remembered as the third surgeon (after von Eiselsberg and Elsberg) who successfully removed an intramedullary lesion in a patient. CONCLUSION Brun should be remembered as an early and successful surgeon in this specialized field. His operative work is described in detail in this article. At the same time, his achievements in the fields of brain and disc herniation surgery are presented.

Interactions between Siglec-7/9 receptors and ligands influence NK cell-dependent tumor immunosurveillance

Abstract Alteration of the surface glycosylation pattern on malignant cells potentially affects tumor immunity by directly influencing interactions with glycan-binding proteins (lectins) on the surface of immunomodulatory cells. The sialic acid-binding Ig-like lectins Siglec-7 and -9 are MHC class I-independent inhibitory receptors on human NK cells that recognize sialic acid-containing carbohydrates. Here, we found that the presence of Siglec-9 defined a subset of cytotoxic NK cells with a mature phenotype and enhanced chemotactic potential. Interestingly, this Siglec-9+ NK cell population was reduced in the peripheral blood of cancer patients. Broad analysis of primary tumor samples revealed that ligands of Siglec-7 and -9 were expressed on human cancer cells of different histological types. Expression of Siglec-7 and -9 ligands was associated with susceptibility of NK cell-sensitive tumor cells and, unexpectedly, of presumably NK cell-resistant tumor cells to NK cell-mediated cytotoxicity. Together, these observations have direct implications for NK cell-based therapies and highlight the requirement to consider both MHC class I haplotype and tumor-specific glycosylation.