Nerve growth factor: an update on the science and therapy.

OBJECTIVE: Nerve growth factor (NGF) is a key regulator of nociceptive pain and thus appears to be an interesting target molecule for an innovative class of analgesic medication. We set out to review the principles of neurogenic inflammation and results of anti-NGF regimens in animal studies as well as clinical trials with patients with back pain and osteoarthritis (OA). DESIGN: We searched using Google Scholar Search and Pubmed as well as through conference reports for articles and abstracts related to NGF and clinical trials using anti-NGF regimens. We report on efficacy findings and adverse events (AEs) related to these agents in this review. RESULTS: We identified five full articles and eight abstract reports relating to anti-NGF agents studied for use in back pain and in OA. CONCLUSIONS: Anti-NGF agents either alone or in combination with non-steroidal anti-inflammatory agents (NSAIDs) were more efficacious for the treatment of pain in a number of trials of knee and hip pain compared to NSAIDs alone. However, adverse effects that included rapidly progressive OA and joint replacement were more common in patients treated with anti-NGF and NSAIDs than either treatment alone. Anti-NGF treatment related neurologic symptoms including paresthesias, and potentially other types of adverse effects were usually transient but warrant additional investigation.

Novel neurological and immunological targets for salicylate-based phytopharmaceuticals and for the anti-depressant imipramine.

Inflammatory processes are increasingly recognised to contribute to neurological and neuropsychatric disorders such as depression. Thus we investigated whether a standardized willow bark preparation (WB) which contains among other constituents salicin, the forerunner of non-steroidal antiphlogistic drugs, would have an effect in a standard model of depression, the forced swimming test (FST), compared to the antidepressant imipramine. Studies were accompanied by gene expression analyses. In order to allocate potential effects to the different constituents of WB, fractions of the extract with different compositions of salicyl alcohol derivative and polyphenols were also investigated. Male Sprague Dawley rats (n=12/group) were treated for 14 days (p.o.) with the WB preparation STW 33-I (group A) and its fractions (FR) (groups FR-B to E) in concentrations of 30 mg/kg. The FRs were characterized by a high content of flavone and chalcone glycosides (FR-B), flavonoid glycosides and salicyl alcohol derivatives (FR-C), salicin and related salicyl alcohol derivatives (FR-D) and proanthocyanidines (FR-E). The tricyclic antidepressant imipramine (20 mg/kg) (F) was used as positive control. The FST was performed on day 15. The cumulative immobility time was significantly (p<0.05) reduced in group A (36%), group FR-D (44%) and by imipramine (16%) compared to untreated controls. RNA was isolated from peripheral blood. RNA samples (group A, group FR-D, and imipramine) were further analysed by rat whole genome microarray (Agilent) in comparison to untreated controls. Quantitative PCR for selected genes was performed. Genes (>2 fold, p<0.01), affected by WB and/or FR-D and imipramine, included both inflammatory (e.g. IL-3, IL-10) and neurologically relevant targets. Common genes regulated by WB, FR-D and imipramine were GRIA 2 ↓, SRP54 ↓, CYP26B ↓, DNM1L ↑ and KITLG ↓. In addition, the hippocampus of rats treated (27 d) with WB (15-60 mg/kg WB) or imipramine (15 mg/kg bw) showed a slower serotonin turnover (5-hydroxyindol acetic acid/serotonin (p<0.05)) depending on the dosage. Thus WB (30 mg/kg), its ethanolic fraction rich in salicyl alcohol derivatives (FR-D) (30 mg/kg) and imipramine, by being effective in the FST, modulated known and new targets relevant for neuro- and immunofunctions in rats. These findings contribute to our understanding of the link between inflammation and neurological functions and may also support the scope for the development of co-medications from salicylate-containing phytopharmaceuticals as multicomponent mixtures with single component synthetic drugs.

Differential diagnoses of suspected Lyme borreliosis or post-Lyme-disease syndrome.

The symptoms of Lyme borreliosis are similar to those of a variety of autoimmune musculoskeletal diseases. Persistence of complaints is frequently interpreted as unsuccessful antibiotic treatment of Borrelia-associated infections. However, such refractory cases are rare, and re-evaluation of differential diagnoses helps to avoid the substantial risk of long-term antibiotic therapy. In this study, we analyzed patients who presented to our rheumatology unit with previous suspected or diagnosed Lyme borreliosis. Eighty-six patients from a 3.5-year period were evaluated. The mean age of patients was 49.2 +/- 17.2 years; 60% (n = 52) reported a tick bite and 33% (n = 28) an erythema. Forty-seven percent (n = 39) had positive enzyme-linked immunoassay results and Western blots (Mikrogen, Martinsried, Germany). All but 12 patients had already received antibiotic treatment previously. Nine percent (n = 8) had ongoing or recent Lyme borreliosis. Twenty-nine percent (n = 25) showed clinical symptoms and radiographic changes compatible with degenerative disorders of the cervical and/or lumbar spine. These patients were significantly older when compared to the other patients (59.3 +/- 13.7 years vs 46.1 +/- 17.2 years, p = 0.001). Seventeen percent (n = 16) had arthropathies related to psoriasis or rheumatoid arthritis. Twelve percent (n = 10) were positive for the HLA B27 antigen. Other diseases were less frequent. Six patients (7%) could not be diagnosed conclusively, and four of these patients had negative Borrelia immunoassay results. In conclusion, Borrelia-associated diseases were rare in this study. Differential diagnoses helped to initiate a successful disease-specific therapeutic strategy.

ICAM-1/LFA-1 expression in acute osteodestructive joint lesions in collagen-induced arthritis in rats.

Collagen-induced arthritis in rats is a widely used model of rheumatoid arthritis (RA). However, the joint immunohistopathology is less well characterized. The objective of this study was therefore to analyze whole ankle joints for markers known to mediate inflammatory mechanisms in RA. Indirect immunohistochemistry was performed on undecalcified cryostat sections for intercellular adhesion molecule-1 (ICAM-1, clone 1A 29) and leukocyte function-associated antigen-1 (LFA-1, clone WT.1) expression, for CD4+ lymphocytes (clone W3/25), B-cells (clone HIS 14), and macrophages (clone ED2). Acute, osteodestructive arthritis (n = 8) induced with bovine collagen Type II was verified by clinical and radiological measures. LFA-1 expression was found almost exclusively at sites associated with cartilage erosion or osteodestruction. ICAM-1 was similarly expressed in the vicinity of tissue degradation but also by blood vessels in peripheral areas of joint swelling. CD4+ lymphocytes and macrophages were more ubiquitous. B-cells were infrequent. In control animals (n = 4) ICAM-1 was expressed by synovial blood vessels. Macrophages were identified at the synovial lining. The results suggest that LFA-1 and ICAM-1 mediate important inflammatory events in this model. Similar findings in human RA synovium provide further arguments that collagen-induced arthritis in rats might be regarded as a comparable disease.

Isolation of arteriolar microvessels and culture of smooth muscle cells from cerebral cortex of guinea pig.

Published methods for the isolation of cerebral microvessels primarily yield terminal resistance vessels and capillary networks, not the more proximal, subpial penetrating arterioles desired for certain studies. We report a novel method for isolating microvessels from the cerebral cortex of a single guinea-pig brain that yields large arteriolar complexes that are up to 50% intact. Instead of using homogenization to disperse brain parenchyma, we digested cortical fragments with trypsin, gently dispersed the parenchyma mechanically, and recovered microvascular complexes by sieving. Phase-contrast and electron microscopy showed primary (penetrating) arterioles, secondary arterioles, and capillary networks that frequently were in continuity as intact microvascular units. Culture of microvascular cells was carried out by enzymatic dissociation followed by an overnight incubation in a recovery medium at 4 degrees C before plating onto fibronectin-modified surfaces. Viability of isolated cells was demonstrated by good cell attachment and prompt proliferation that resulted in confluent cultures after 10 days. Confluent secondary cultures demonstrated characteristic features of smooth muscle cells, including a "hill-and-valley" growth pattern and expression of alpha-actin. Less than 1% of cells were endothelial or astrocytic cells by immunocytochemical and morphologic criteria. Ultrastructural studies demonstrated evidence of a synthetic phenotype of smooth muscle cell and absence of a significant number of fibroblasts. This method demonstrates that viable smooth muscle cells from the cerebral parenchymal microvasculature can be isolated in bulk quantities for study in vitro.