A new method for determining bronchospasmolytic drug effects in vagotomized guinea pigs

Airways resistance to electrical field stimulation of the vagus nerves was applied to study the efficacies of atropine and trospium chloride in anesthetized guinea pigs. Stimulation induced an airways resistance that was reproducible, thereby significantly lowering blood pressure and reducing heart rate (p less than 0.05). The induced airways resistance was antagonized using 5 micrograms/kg of either atropine or trospium, but was unaffected by physiological sodium chloride solution. At the dose 10 micrograms/kg, trospium chloride was significantly more potent than atropine which showed only slight augmentation in activity. The present results demonstrate that this procedure can be utilized to investigate, both qualitatively and quantitatively, the actions of anticholinergic and bronchospasmolytic agents in laboratory set-ups.     

Proteinase-3 mRNA expressed by glomerular epithelial cells correlates with crescent formation in Wegener's granulomatosis

BACKGROUND: Wegener's granulomatosis (WG) is characterized by systemic vasculitis with crescentic glomerulonephritis (CGN) and circulating autoantibodies directed against neutrophil cytoplasmic antigens (ANCA). Proteinase 3 (PR-3), a neutral serine proteinase in neutrophils implicated in the growth control of myeloid cells, has been identified as the target antigen for ANCA in WG. Since the kidneys are frequently involved in WG, we studied the in situ expression of PR-3 by renal parenchymal cells. METHODS: We assessed the expression of PR-3 in kidney biopsies of 15 patients with WG by immunohistochemistry (IHC) and in situ hybridization (ISH). Normal kidney tissue served as the control. RESULTS: We detected PR-3 mRNA and PR-3 protein in distal tubular epithelial cells (TECs) and glomerular epithelial cells (GECs) in normal kidney tissue and in CGN. Furthermore, a strong glomerular PR-3mRNA expression restricted to the site of cellular crescents was detected in patients with WG. The analysis of 144 glomeruli with cellular or sclerotic crescents revealed a positive correlation of glomerular PR-3mRNA expression with the percentage of cellular crescents per glomerulus. The capability of human TECs and GECs to synthesize PR-3 was confirmed by Northern blot and ISH on cultured cells. CONCLUSION: These data provide evidence that nonhematopoetic renal parenchymal cells express PR-3 and that glomerular expression of PR-3 is associated with crescent formation in WG. Our findings suggest that renal parenchymal cells may directly be involved in the pathogenesis of CGN in WG.     

Influence of tissue affinity of angiotensin-converting enzyme inhibitors on left ventricular remodeling after myocardial infarction

Background: The demonstration of local renin-angiotension systems has raised the question of whether angiotensinconverting enzyme (ACE) inhibitors with different tissue affinities differ with regard to their effects on postinfarction remodeling. Hypothesis: The study was undertaken to investigate the influence of ACE inhibitors with different tissue affinity on morphology and function of the infarcted left ventricle. Methods: In all, 52 patients (17 women, 35 men, 38-73 years) with large acute myocardial infarction were randomized to receive either 25-75 mg/day captopril or 10-20 mg/day fosinopril beginning on the Day 7 after infarction. Of these, 28 had anterior and 24 had posterior wall infarctions. Infarct size was determined by the creatine kinase integral method. Fifty patients were examined by cinemagnetic resonance imaging (CMRI) 1 and 26 weeks after infarction. The following parameters were determined: left ventricular enddiastolic and end-systolic volume index (LVEDVI, LVESVI), ejection fraction (LVEF), infarct weight, and muscle mass (LVMM). The volume-to-mass ratio (VMR) was calculated and the clinical status according to the guidelines of the New York Heart Association (NYHA) was documented at each examination time. The results were compared with those of a historical sample without ACE-inhibitor therapy examined in an identical manner (n = 31, 10 women, 21 men, 36-75 years). Results: LVEDVI and LVESVI increased in the first 6 months after infarction by 24.9 and 36.6%, respectively, in the historical sample; by 11.0 and 7.8%, respectively, under captopril; and by 13.1 and 10.7%, respectively, under fosinopril. LVEF decreased by 14.9% in the untreated sample, by 3.7% under captopril and by 5.0% under fosinopril. Infarct weight and LVMM increased by 12.7 and 15.3%, respectively, without ACE inhibition, by 5.7 and 10.1%, respectively, in patients treated with captopril, and by 6.1 and 9.3%, respectively, in patients treated with fosinopril. The VMR increased by 7.4% in the historical sample, by 3.5% in the captopril group, and by 1.8% in the fosinopril group. The NYHA clinical status improved by 18.2% without ACE inhibition, by 42.9% in the captopril group, and by 26.3% in the fosinopril group. The differences between the two ACE-inhibitor groups and the reference group were all significant, while the differences between the captopril group and the fosinopril group were significant only for VMR (p<0.01) and NYHA class (p < 0.05). Conclusions: Both captopril and fosinopril have a comparable positive influence on postinfarction remodeling and on clinical status. Lipophilicity and tissue affinity do not seem to play a clinically important role in ACE-inhibitor therapy after infarction.     

Toll-like receptor 2-mediated innate immune response in human nonparenchymal liver cells toward adeno-associated viral vectors

Adeno-associated viral vectors (rAAV) are frequently used in gene therapy trials. Although rAAV vectors are of low immunogenicity, humoral as well as T cell responses may be induced. While the former limits vector reapplication, the expansion of cytotoxic T cells correlates with liver inflammation and loss of transduced hepatocytes. Because adaptive immune responses are a consequence of recognition by the innate immune system, we aimed to characterize cell autonomous immune responses elicited by rAAV in primary human hepatocytes and nonparenchymal liver cells. Surprisingly, Kupffer cells, but also liver sinusoidal endothelial cells, mounted responses to rAAV, whereas neither rAAV2 nor rAAV8 were recognized by hepatocytes. Viral capsids were sensed at the cell surface as pathogen-associated molecular patterns by Toll-like receptor 2. In contrast to the Toll-like receptor 9-mediated recognition observed in plasmacytoid dendritic cells, immune recognition of rAAV in primary human liver cells did not induce a type I interferon response, but up-regulated inflammatory cytokines through activation of nuclear factor κB. CONCLUSION: Using primary human liver cells, we identified a novel mechanism of rAAV recognition in the liver, demonstrating that alternative means of sensing rAAV particles have evolved. Minimizing this recognition will be key to improving rAAV-mediated gene transfer and reducing side effects in clinical trials due to immune responses against rAAV.     

The impact of fluorescence guidance on spinal intradural tumour surgery

Purpose

5-Aminolevulinic acid (5-ALA)-based fluorescence-guided surgery was shown to be beneficial for cerebral malignant gliomas. Extension of this technique for resection of meningiomas and cerebral metastasis has been recently evaluated. Aim of the present study is to evaluate the impact of fluorescence-guided surgery in spinal tumor surgery.

Methods

Twenty-six patients with intradural spinal tumors were included in the study. 5-ALA was administered orally prior to the induction of anesthesia. Intraoperative, 440 nm fluorescence was applied after exploration of the tumor and, if positive, periodically during and at the end of resection to detect tumor-infiltrated sites.

Results

Tumors of WHO grade III and IV were found in five patients. In detail intra- or perimedullary metastasis of malignant cerebral gliomas was found including glioblastoma WHO grade IV (n = 2), anaplastic astrocytoma WHO grade III (n = 1), anaplastic oligoastrocytoma WHO grade III (n = 1). In addition, one patient suffered from a spinal drop metastasis of a cerebellar medulloblastoma WHO grade IV. Tumors of WHO grade I were diagnosed in 18 patients: Eight cases of meningioma (two recurrences), six cases of neurinoma, one neurofibroma, two ependymoma and one plexus papilloma. At least, benign pathologies were histologically proven in three patients. All four spinal metastasis of malignant glioma (100 %), seven of eight meningiomas (87.5 %) and one of two ependymoma (50 %) were found to be ALA-positive.

Conclusion

The present study demonstrates that spinal intramedullary gliomas and the majority of spinal intradural meningiomas are 5-ALA positive. As a surgical consequence, especially in intramedullary gliomas, the use of 5-ALA fluorescence seems to be beneficial.     

The impact of cerebral metastases growth pattern on neurosurgical treatment

The surgical resection of cerebral metastases is one key element in a multimodal therapy of brain oligometastatic patients. Standard surgery alone is often not sufficient to achieve local control. Various reasons have been discussed including microscopic and macroscopic tumor rests after surgery and different growth patterns of cerebral metastases: In this review, we assessed the surgical standard technique and then analyzed the growth pattern of cerebral metastases and discussed its oncologic impact and new strategies in the surgical management of cerebral metastases. A major percentage of cerebral metastases are not sharply delimitated but show an irregular tumor-brain interface or even an infiltrative growth pattern. Different patterns of adjacent brain invasions have been described and may correlate with the prognosis of patients with cerebral metastasis. Even metastases of the same histological subtype and the same origin show a heterogeneous brain invasion pattern. Future therapeutic strategies might have to take this heterogeneity into account. An infiltrative growth pattern of cerebral metastases might be one reason for their extraordinary high local recurrence rate and might have an influence on the individual overall survival. An intraoperative detection of residual tumor and development of more radical surgical techniques is therefore an important neurooncological challenge and might result in better tumor control. Supramarginal resection of cerebral metastases is a promising approach.