Peptide screening of cerebrospinal fluid in patients with glioblastoma multiforme.

AIMS: To apply modern mass spectrometry based technology to identify possible CSF peptide markers of glioblastoma multiforme (GBM). METHODS: Mass spectrometry based peptidomics technology enables a systematic and comprehensive screening of cerebrospinal fluid (CSF) with regard to its peptide composition. Differential Peptide Display (DPD) allows the identification of single marker peptides for a target disease. Using both, we analyzed CSF samples of 11 patients harbouring a glioblastoma multiforme in comparison to 13 normal controls. RESULTS: Four CSF peptides which significantly distinguished GBM from controls in all applied statistic tests could be identified out of more than 2,000 detected CSF peptides. They were specific C-terminal fragments of alpha-1-antichymotrypsin, osteopontin, and transthyretin as well as a N-terminal residue of albumin. All molecules are constituents of normal CSF, but none has previously been reported to be significantly elevated in CSF of GBM patients. CONCLUSION: The study showed that peptidomics technology is able to identify possible biomarkers of neoplastic CNS disease. It remains to be determined if the identified elevated CSF peptides are specific for GBM. With regard to GBM, however, the more important role of CSF peptide biomarkers than aiding initial diagnosis might be early recognition of disease recurrence or monitoring of efficacy of adjuvant therapy protocols.

Dynamic shunt testing applying short lasting pressure waves--inertia of shunt systems.

Laboratory shunt testing often comprises only static pressure flow and flow pressure tests. We applied shorter acting pressure waves using a computerised shunt testing rig to investigate shunt behaviour under conditions that might occur in the clinical situation, e.g. during nocturnal vasogenic pressure waves or shorter rises in ICP at movements or exercise. Additionally the influence of a human-like compliance situation compared to a fixed pressure/volume relationship was investigated. Shunts behaved very differently than seen in static tests and demonstrated a marked inertia the shorter pressure waves acted. Although some valves opened at higher pressure, all valves showed marked hysteresis and none did close--if at all--at the specified pressure level. This behaviour might be a cause of shunt overdrainage not related to siphoning. The simulation of a human-like variable pressure-volume relationship with higher compliance at lower pressures had a positive effect on shunt function by decreasing the amount of drained volume. We therefore suggest to include dynamic pressure wave testing if hydrodynamic properties of shunts are to be evaluated.

Acute care in neurosurgery: quantity, quality, and challenges.

OBJECTIVE: Part of the daily routine in neurosurgery is the treatment of emergency room admissions, and acute cases from other departments or from outside hospitals. This acute care is not normally included in performance figures or budget management, nor analysed scientifically in respect of quantity and quality of care provided by neurosurgeons. METHOD: Over a 1 year period, all acute care cases managed by two neurosurgical on call teams in a large northern German city, were recorded prospectively on a day by day basis. A large database of 1819 entries was created and analysed using descriptive statistics. RESULTS: The minimum incidence of patients requiring neurosurgical acute care was estimated to be 75-115/100 000 inhabitants/year. This corresponds to a mean of about 6/day. Only 30% of patients came directly via the emergency room. The fate of 70% of patients depended initially on the "neurosurgical qualification" of primary care doctors and here deficits existed. Although most intracerebral and subarachnoid haemorrhages were managed with the participation of neurosurgeons, they were not involved in the management of most mild and moderate traumatic brain injuries. Within 1 year the additional workload from acute care amounted to 1000 unplanned admissions, 900 acute imaging procedures, and almost 400 emergency operations. CONCLUSION: The current policy in public health, which includes cuts in resources, transport facilities, and manpower, is not compatible with the demonstrated extent of acute neurosurgical care. In addition to routine elective work, many extra admissions, evening or night time surgery, and imaging procedures have to be accomplished. An education programme for generalists is required to improve overall patient outcome. These conclusions hold special importance if health authorities wish to not only maintain present standards but aim to improve existing deficits.

Arterial supply of the temporo-medial region of the brain: significance for preoperative vascular occlusion testing.

The mesiobasal limbic system is of particular significance in the surgical treatment of temporo-medial tumors and epilepsy. It consists of the uncus, amygdaloid body, hippocampus, dentate gyrus, subiculum, fasciolar gyrus and the parahippocampal gyrus. Knowledge of the vascular microanatomy is a key to the surgical treatment of pathologies in the region. The anterior choroidal artery was selectively injected in fresh brain specimens: 50 specimens with a gelatinous ink mixture to demonstrate vascular territories in stereotactic brain slices, and 50 with a Biodur resin to obtain casts for microanatomical evaluation. The cast technique was also applied to 35 specimens injected into the posterior cerebral artery. The rostral third of the temporomedial region is mainly supplied by branches of the anterior choroidal artery. The occipital two thirds are supplied by hippocampal branches, the posteromedial choroidal artery and the inferior temporal branches of the posterior cerebral artery. Important vessel variations with significant implications for the preoperative Wada-test are presented.

Low-dose interleukin-2 in combination with interferon-alpha effectively modulates biological response in vivo.

Phenotypic characterization of peripheral blood lymphocytes was performed in patients with advanced metastatic cancer receiving low-dose recombinant interleukin-2 (rIL-2) and recombinant interferon-alpha (rIFN-alpha) as subcutaneous home therapy. A total of 31 patients with progressive metastatic renal cell carcinoma, malignant melanoma, colorectal cancer, B-cell lymphoma, and Hodgkin's disease, were evaluated. Patients were treated with a combination of low-dose subcutaneous rIL-2 and rIFN-alpha, consisting of a 2-day rIL-2 pulse at 9.0 million IU/m2 twice daily, followed by 6 weeks of combined low-dose rIL-2 at 1.8 million IU/m2 twice daily, 5 days per week, and rIFN-alpha at 5.0 million U/m2 3 times per week. This treatment regimen resulted in an overall significant (p < 0.002) increase in peripheral blood lymphocyte subsets expressing CD3, CD8, CD16, CD25, and CD56. Expansion of peripheral blood natural killer (NK) cells was correlated to treatment response. Thus, treatment-related increase in CD56-positive lymphocytes was 1.8-fold higher in complete or partial responders when compared to progressive disease patients (p = 0.0). Increase in NK cells upon low-dose rIL-2 and rIFN-alpha was associated with a significant expansion (p = 0.0) of peripheral blood eosinophils (r = 0.71). Patient pretreatment using rIL-2, rIL-2 and rIFN-alpha, or chemotherapy abrogated the treatment-induced induction of NK cells and IL-2 receptor- (CD25) positive T lymphocytes, respectively. Peripheral blood NK cells were significantly decreased (p < 0.05) in patients developing neutralizing antibodies specific to rIL-2.

Biological monitoring of low-dose interleukin 2 in humans: soluble interleukin 2 receptors, cytokines, and cell surface phenotypes.

Different immunotherapy regimens using s.c. recombinant interleukin-2 (rIL-2) were studied in 76 patients with progressive metastatic renal carcinoma, malignant melanoma, colorectal cancer, B-cell lymphoma, or Hodgkin's disease. To assess the immunomodulatory capacity of rIL-2, we measured serum levels of soluble interleukin-2 (sIL-2) receptors, gamma-interferon, tumor necrosis factor-alpha, and various lymphocyte subsets expressing the CD25 Tac IL-2 receptor and the CD56 natural killer (NK) associated antigen. Additionally, we measured serum antibodies specific to rIL-2 in order to evaluate immunogenicity of rIL-2. In all patients, a significant increase in sIL-2 receptor levels could be observed when comparing values on day 0 and after one treatment course. Patients developing a neutralizing anti-rIL-2 antibody exhibited significantly lower serum sIL-2 receptor levels than patients without antibody. Soluble IL-2 receptors correlated with the percentage of CD25 IL-2 receptor-positive peripheral blood lymphocytes. Both soluble and cell surface IL-2 receptors exhibited a significant increase during rIL-2 therapy but did not correlate with the percentage of CD56-positive peripheral blood lymphocytes. Measurement of treatment-induced secondary cytokines showed significant increases in gamma-interferon serum levels in a proportion of patients tested, although with considerable interindividual variability. No significant increase in mean tumor necrosis factor-alpha levels was observed during rIL-2 treatment in vivo. The percentage of CD56-positive NK cells correlated with the clinical outcome of rIL-2 therapy. Thus, partial or complete responders had an increase from a mean of 20% NK cells prior to therapy up to a mean of 40% after the first treatment course. In contrast, patients with progressive disease had a mean of 22 and 24% NK cells before and after treatment, respectively.

Immunophenotypic demonstration of two natural killer surface markers, H25 and H366, on fresh human leukemic cells.

Using a modified alkaline-phosphatase/antialkaline-phosphatase method for phenotyping fresh human leukemias, we could demonstrate peripheral blood and bone marrow-derived blast cells to specifically react with two monoclonal antibodies (MoAbs), H25 and H366, previously shown to recognize natural killer cells, activated T lymphocytes and a proportion of normal hematopoietic precursor cells. MoAbs H25 and H366 were found to identify the majority of leukemic cells in patients presenting with T-ALL, LGL leukemia, pre-B-ALL, CML, and AML, respectively.