MALDI IMS and Cancer Tissue Microarrays

Matrix-assisted laser desorption/ionization imaging mass spectrometry (MALDI IMS) technology creates a link between the molecular assessment of numerous molecules and the morphological information about their special distribution. The application of MALDI IMS on formalin-fixed paraffin-embedded (FFPE) tissue microarrays (TMAs) is suitable for large-scale discovery analyses. Data acquired from FFPE TMA cancer samples in current research are very promising, and applications for routine diagnostics are under development. With the current rapid advances in both technology and applications, MALDI IMS technology is expected to enter into routine diagnostics soon. This chapter is intended to be comprehensive with respect to all aspects and considerations for the application of MALDI IMS on FFPE cancer TMAs with in-depth notes on technical aspects.

MALDI imaging of predictive ferritin, fibrinogen and proteases in haemophilic arthropathy

Arthropathy as a result of repeated joint bleeding is a severe complication in patients with haemophilia. In the evaluation of synovial tissue specimens, histology alone is non-specific and there is considerable morphological overlap with other joint diseases. Formalin-fixed paraffin-embedded specimens are available in pathological institutes and can be studied to understand the pathogenesis of haemophilic arthropathy. A powerful technique to identify hundreds of proteins in a tissue section combining proteomics with morphology is imaging mass spectrometry (IMS). We determined whether matrix-assisted laser desorption/ionization (MALDI) IMS can be used to identify and map protein signatures in the synovial tissue of patients with haemophilic arthropathy. MALDI IMS was applied to synovial tissue of six patients with haemophilic arthropathy. We detected several peaks predictive in mass with ferritin light (m/z 1608) and heavy chain (m/z 1345), alpha- (m/z 1071) and beta (m/z 1274) haemoglobin subunits, truncated coagulation factor VIII peptide (m/z 1502, 1176), beta- and gamma fibrinogen peptides (m/z 980, 1032, 1117 and 1683), and annexin A2 (m/z 1111, 1268, 1460, 2164). In addition, the distribution of these proteins in synovial tissue sections was demonstrated. MALDI IMS identified and mapped specific proteins in the synovial membrane of patients with haemophilic arthropathy known to be involved in the pathogenesis of other joint diseases. This technique is a powerful tool to analyse the distribution of proteins in synovial tissue sections.

[Soft tissue tumor near the joint: hibernoma]

Joint associated tumors must undergo histological analysis, since not only inflammatory, but also benign and malign tumors exist in this location. We report a well circumscribed tumor, located in the elbow that histologically turned out to be a hibernoma. Complete surgical excision is the therapy of choice and recurrences are rare. To rule out liposarcoma with hibernoma like changes, fluorescence in-situ hybridisation has been performed and showed no MDM-2 amplification. Hibernomas are tumors of brown adipose tissue that may be localized next to joints.

MALDI MS imaging as a powerful tool for investigating synovial tissue

OBJECTIVE

To identify and image protein biomarker candidates in the synovial tissue of patients with rheumatoid arthritis (RA) and patients with osteoarthritis (OA).

METHODS

A novel matrix-assisted laser desorption/ionization (MALDI) imaging mass spectrometry (IMS) technique was applied to the analysis of synovial tissue. Patients were classified according to the American College of Rheumatology (ACR) criteria for RA. Frozen sections were stained to obtain morphological data. Serial sections were desiccated, and spotted with matrix for MALDI analysis. Ions generated by laser irradiation of the tissue were separated in time, based on their m/z ratio, and were subsequently detected. IMS was used in a 'profiling' mode to detect discrete spots for rapid evaluation of proteomic patterns in various tissue compartments. Photomicrographs of the stained tissue images were reviewed by a pathologist. Areas of interest (10 discrete areas/compartment) were marked digitally and the histology-annotated images were merged to form a photomicrograph of the section taken before the MALDI measurement. Pixel coordinates of these areas were transferred to a robotic spotter, the matrix was spotted, and the coordinates of the spots were transferred to a mass spectrometer for spectral acquisition. The data generated were then subjected to biocomputation analysis to reveal the biomarker candidates.

RESULTS

Several peaks (m/z) consistent in mass with calgranulins, defensins, and thymosins were detected and their distribution in various synovial compartments (synovial lining and sublining layer) was demonstrated.

CONCLUSION

MALDI IMS is a powerful tool for the rapid detection of numerous proteins (in situ proteomics) and was applied here for the analysis of the distribution of proteins in synovial tissue sections.

[Bone marrow edema in magnetic resonance imaging. A misleading term?]

Magnetic resonance imaging (MRI) is a mainstay in musculoskeletal imaging. The term"bone marrow edema" is frequently used for describing the radiological findings, especially with respect to rheumatic diseases. The referring physician should be aware that this term has a purely descriptive character and the pathophysiology of signal alterations in MRI shows a broad spectrum certainly not always corresponding to increased liquid contents. The recommendations therefore tend towards the use of the neutral terms"osteitis","bone marrow edema-like lesion" or"bone marrow lesion" instead of the misleading term"bone marrow edema".

[Gout - regardless of therapeutic options a "forgotten" disease]

Compared to other chronic inflammatory diseases, gout appears to based on a rather "simple" pathophysiology and therefore the amount of teaching time in medical school and during internship is rather limited. On the other hand, several problems in short- and long-term management still need to be solved - combined with the problem of an increased incidence in elderly people. However, there is significant advance in the knowledge of its pathophysiology including the fact that gout is more than a pure "crystal arthopathy" but rather within the spectrum of chronic inflammatory immunologic diseases. This includes cytokines such as interleukin-1 and intracellular signaling via the inflammasome. For treatment, the novel and effective xanthine oxidase inhibitor febuxostat has been added to the therapeutic armamentarium. Guidelines of EULAR and BSR support the physician in the long-term management of the numerous gout patients.

[Is bioptic assurance reasonable in patients with Sjögren's syndrome? From focus score to diagnosing vasculitides]

Sjögren's syndrome is an autoimmune disease which targets the salivary and lacrimal glands in particular, causing sicca syndrome. Extraglandular manifestations are often seen. Chronic sialadenitis of the parotid gland is the most common symptom to be assessed for differential diagnosis. Common HE and Giemsa slices are histopathologically examined and graduated for lymphocyte infiltration (focus): grade 0: absent, grade 1: slight, grade 2: moderate non-focal infiltration, grade 3: 1 focus (> or =50 lymphocytes) per 4 mm2, grade 4: >1 focus. Grade 3 infiltrates correspond to a focus score of 1, which is one of four disease-classifying criteria acknowledged for diagnosis. Bioptic examination is also performed to rule out different (non-) immunologic sialadenitises, such as the necrotizing or epithelioid-like form (in sarcoidosis), and the extranodal marginal-zone lymphoma. Extraglandular manifestations of Sjögren's syndrome can also be safely diagnosed by histopathological examination. Emphases lie on vasculitides and myositides. Bioptic work-up, therefore, is not only reasonable but also an essential tool for diagnostics in Sjögren's syndrome.

[Diagnostics of glomerulonephritis]

Glomerulonephritis occurs frequently in patients with multisystemic rheumatic disease, especially in collagen vascular disorders and vasculitides. From a clinical point of view nephrotic syndrome has to be distinguished from nephritic syndrome. Rapid deterioration of renal function is referred to as rapid progressive glomerulonephritis. The differential diagnosis of glomerulonephritis can be narrowed by the findings on urine sediment, amount of proteinuria, degree of renal insufficiency and serological findings. In particular, the presence of urine acanthocytes and cellular casts are diagnostic for glomerulonephritis or vasculitis. Renal biopsy is necessary to establish the final diagnosis in most cases; however, some histological pattern such as membranous glomerulonephritis may occur in several different etiopathogenetic diseases and one disease process may lead to different histomorphologic pictures. Rapid progressive glomerulonephritis is a nephrological emergency and should be diagnosed and treated early to prevent dialysis-dependent renal insufficiency.

Colocalization of C4d deposits/CD68+ macrophages in rheumatoid nodule and granuloma annulare: immunohistochemical evidence of a complement-mediated mechanism in fibrinoid necrosis

Rheumatoid nodule (RN) represents a palisading granuloma with central fibrinoid necrosis, which is not only a classical manifestation of rheumatoid arthritis (RA) and part of the American College of Rheumatology (ACR)-criteria, but also is its diagnostic hallmark. The pathogenesis of RN is still not fully understood. At present, only data on serum analyses indicating a complement-mediated pathogenesis in the development of RA are available. Equivalent examinations for RN have not yet been performed. Granuloma annulare (GA) represents another type of palisading granuloma. A special subtype of GA, subcutaneous GA (SGA), is an important differential diagnosis to RN. Therefore, our aim was to examine RN and SGA regarding the complement deposition (C4d) by immunohistochemical means. All RN and GA were stained by hematoxylin/eosin and different special stains. In addition, all specimens were stained immunohistochemically with antibodies against CD68. Five GA and five RN were analyzed immunohistochemically with antibodies against C4d and CD68, and evaluated using single- and doublestaining immunohistochemistry. All RN and GA displayed depositions of C4d within their central necroses and between the surrounding palisading macrophages. Most importantly, C4d/CD68 double staining was visible in the palisading macrophages next to the necroses, while macrophages in the periphery were negative for C4d but positive for CD68. The main difference between RN and GA was a quantitative phenomenon with less positively reacting macrophages in a more incomplete palisade in GA. The positive reactions of all central necroses to C4d and colocalization of CD68 and C4d suggest that a complement-mediated mechanism may be operative in the formation of fibrinoid necrosis. This mechanism may be involved in any form of "fibrinoid necrosis", since no different patterns of C4d/CD68 expression could be observed in GA. This may explain why RG/GA are not distinguishable morphologically.

[Differential diagnosis of rheumatoid granuloma]

Rheumatoid granuloma (RG) is histomorphologically defined as a subcutaneous palisading granuloma with central fibrinoid necrosis. Clinically, it presents as a nodule typically localized at pressure points near the joints. From the rheumatic pathological point of view, the main diagnostic challenge is the differentiation of RG from granuloma anulare, especially if clinical information on the site of removal, known diseases, duration of illness, medication and existing American College of Rheumatology (ACR) criteria are missing. Other granulomatous lesions, such as mycobacterial infections, foreign body granulomas, necrobiosis lipoidica or sarcoidosis, can be differentiated from RG by histopathological criteria or by additional examinations such as pathogen specification or PCR. An immunohistochemical marker for the differential diagnosis of granulomas is not yet available. Diagnosis is based on conventional H-E staining, alcian blue-PAS staining, polarizing analysis or PCR. In the following article, the most important granulomatous entities in the differential diagnosis of RG are introduced and the main diagnostic characteristics are discussed.

Abriebpartikel

The aseptic prosthetic loosening of hip and knee prosthesis is the most important cause of implant insufficiency. Bone loss as a result of the biological effect of wear particles is the main cause of such loosening. Wear particles develop their biological activity along different cellular pathways, above all via macrophages, foreign body giant cells as well as fibroblasts of the periprosthetic membrane. These cells induce particle-dependent bone resorption by means of proinflammatory cytokines, such as IL-1beta, TNF-alpha, IL-6 and PGE2. These factors induce the activation of osteoclasts as well as the suppression of osteoblasts. Neutrophil granulocytes and lymphocytes do not play an important role in the process of aseptic loosening. The different wear particles, such as ultra-high molecular weight polyethylene, metal particles, ceramic particles and polymethylmethacrylate can be morphologically recognized very easily. From the clinical point of view, the differentiation between acute or chronic implant infection and particle induced prosthetic loosening is very important, with the histomorphological differential diagnosis between septic and aseptic loosening and their combination being the key clinicopathological factor.

[Low-grade-/high-grade-synovitis: synovitis-score as a gold standard?]

BACKGROUND

Synovectomy specimens represent important material submitted from the orthopedist to the pathologist. However, no consistent histopathological grading system for chronic synovitis has been established so far.

PATIENTS AND METHODS

The three compartments of chronic synovitis (enlargement of lining cell layer, density of synovial stroma cells, leukocytic infiltrate) are graded semiquantitatively (from 0=absent to 3=strong), and the points for each compartment add up to the synovitis score: 0-1 = no synovitis, 2-4 = low-grade synovitis, 5-9 = high-grade synovitis. A total of 618 synovial specimens (resections n=559, biopsies n=59) from degenerative and inflammatory joint diseases were graded by two independent observers.

RESULTS

Median synovitis scores when correlated to clinical diagnoses were: 1, control; 2, osteoarthritis and post-traumatic arthritis; 3, psoriatic arthritis; 5, reactive and rheumatoid arthritis. The differences between rheumatic and non-rheumatic diseases were significant (p<0.001). The correlation between the two observers was high (p<0.001).

CONCLUSIONS

The proposed synovitis score enables stratification of chronic synovitis into low-grade (score 2-4) and high-grade (score >4), which is correlated to the nature of the disease (low-grade to non-rheumatic, high-grade to rheumatic), and it therefore contributes to the diagnosis of rheumatic and non-rheumatic joint diseases.

Proposal for a histopathological consensus classification of the periprosthetic interface membrane

AIMS

The introduction of clearly defined histopathological criteria for a standardised evaluation of the periprosthetic membrane, which can appear in cases of total joint arthroplasty revision surgery.

METHODS

Based on histomorphological criteria, four types of periprosthetic membrane were defined: wear particle induced type (detection of foreign body particles; macrophages and multinucleated giant cells occupy at least 20% of the area; type I); infectious type (granulation tissue with neutrophilic granulocytes, plasma cells and few, if any, wear particles; type II); combined type (aspects of type I and type II occur simultaneously; type III); and indeterminate type (neither criteria for type I nor type II are fulfilled; type IV). The periprosthetic membranes of 370 patients (217 women, 153 men; mean age 67.6 years, mean period until revision surgery 7.4 years) were analysed according to the defined criteria.

RESULTS

Frequency of histopathological membrane types was: type I 54.3%, type II 19.7%, type III 5.4%, type IV 15.4%, and not assessable 5.1%. The mean period between primary arthroplasty and revision surgery was 10.1 years for type I, 3.2 years for type II, 4.5 years for type III and 5.4 years for type IV. The correlation between histopathological and microbiological diagnosis was high (89.7%), and the inter-observer reproducibility sufficient (85%).

CONCLUSION

The classification proposed enables standardised typing of periprosthetic membranes and may serve as a tool for further research on the pathogenesis of the loosening of total joint replacement. The study highlights the importance of non-infectious, non-particle induced loosening of prosthetic devices in orthopaedic surgery (membrane type IV), which was observed in 15.4% of patients.

Correlation of quantitative histopathological morphology and quantitative radiological analysis during aseptic loosening of hip endoprostheses

OBJECTIVE

Aseptic hip prosthesis loosening is the most important long-term complication in total hip arthroplasty. Polyethylene (PE) wear is the dominant etiologic factor in aseptic loosening, which together with other factors induces mechanisms resulting in bone loss, and finally in implant loosening. The single-shot radiograph analysis (EBRA, abbreviation for the German term ""Einzel-Bild-Röntgenanalyse"") is a computerized method for early radiological prediction of aseptic loosening. In this study, EBRA parameters were correlated with histomorphological parameters of the periprosthetic membrane.

METHODS

Periprosthetic membranes obtained from 19 patients during revision surgery of loosened ABG I-type total hip pros-theses were analyzed histologically and morphometrically. The pre-existing EBRA parameters, the thickness of the PE debris lay-er and the dimension of inclination and anteversion, were compared with the density of macrophages and giant cells. Addi-tionally, the semiquantitatively determined density of lymphocytes, plasma cells, giant cells and the size of the necrotic areas were correlated with the EBRA results.

RESULTS

All periprosthetic membranes were classified as debris-induced type membranes. We found a positive correlation between the number of giant cells and the thickness of the PE debris layer. There was no significant correlation between the number of macrophages or all semiquantitative parameters and EBRA parameters. The number of giant cells decreased with implant duration.

CONCLUSION

The morphometrically measured number of foreign body giant cells more closely reflects the results of the EBRA. The semiquantitative estimation of giant cell density could not substitute for the morphometrical analysis. The density of macrophages, lymphocytes, plasma cells and the size of necrotic areas did not correlate with the EBRA parameters, indicating that there is no correlation with aseptic loosening.

[Proposal for the classification of the periprosthetic membrane from loosened hip and knee endoprostheses]

After 10 years, loosening of total joint endoprostheses occurs in about 3 to 10 percent of all patients, requiring elaborate revision surgery. A periprosthetic membrane is routinely found between bone and loosened prosthesis. Further histomorphological examination allows determination of the etiology of the loosening process. Aim of this study is the introduction of clearly defined histopathological criteria for a standardized evaluation of the periprosthetic membrane. Based on histomorphological criteria and polarized light microscopy, four types of the periprosthetic membrane were defined: periprosthetic membrane of wear particle type (type I), periprosthetic membrane of infectious type (type II), periprosthetic membrane of combined type (type III), periprosthetic membrane of indifferent type (type IV). Periprosthetic membranes of 268 patients were analyzed according to the defined criteria. The correlation between histopathological and microbiological diagnosis was high (89%, p<0,001), the inter-observer reproducibility was sufficient (95%). This classification system enables a standardized diagnostic procedure and therefore is a basis for further studies concerning the etiology of and pathogenesis of prosthesis loosening.

Expression of fibronectin splice variants and oncofetal glycosylated fibronectin in the synovial membranes of patients with rheumatoid arthritis and osteoarthritis

OBJECTIVE

The aim of this study was to define and compare the expression of fibronectin (Fn) isoforms in synovial tissue of patients with rheumatoid arthritis (RA) and osteoarthritis (OA).

METHODS

Using monoclonal antibodies specific for total Fn, extra domain (ED)-A Fn, ED-B Fn, and oncofetal glycosylated Fn, we studied the expression of the Fn isoforms in synovium. Furthermore, in situ hybridization for the detection of ED-B Fn mRNA including a double labeling technique for the detection of cell type was applied.

RESULTS

Strong expression of total Fn, ED-A Fn, oncofetal glycosylated Fn and, to a lesser extent, ED-B Fn could be demonstrated in the synovial lining layer in both RA and OA. Stromal and vessel expression of Fn isoforms was more prominent in RA tissue. Pannus tissue showed strong labeling with ED-B Fn.

CONCLUSION

The expression of alternatively spliced isoforms of Fn is associated with tissue remodeling and, as a partial process of this phenomenon, with neovascularization rather than underlying disease, X-ray status, or parameters of acute inflammation. In the lining layer, Fn expression correlates with hyperplasia associated with cell recruitment but not with proliferative status. Most remarkably, the expression of ED-B Fn in pannus tissue seems to be associated with the invasive phenotype described in RA tissue.

[Lupus nephritis with crystal structures in glomerulopathy ]

Lupus nephritis is a common phenomenon in Systemic Lupus Erythematosus (SLE). We analyzed a renal biopsy of a 30-year-old woman with SLE. The clinical history showed a typical SLE with generalized symptoms without demonstrable lupus coagulant, positive for anti-nuclear antibodies and anti-ds-DNA antibodies but negative for rheumatoid factor, cryoglobulins and antiphospholipid antibodies. A paraproteinemia for IgA, IgG and IgM was not detectable. Using light, electron and immunoelectron microscopy electron-dense deposits were noted in subepithelial, subendothelial and mesangial position. Most remarkably, the electron-dense deposits and mesangial areas in the vicinity of deposits contained an electron-dense crystalline material. The crystalline structures were composed of IgG and kappa light chains, while they were negative for IgM, IgA and lambda light chains, as demonstrated by immunoelectron microscopy. As far as we know, this is the first case of lupus nephritis with crystalline structures. Since we could not detect cryoglobulinemia or paraproteinemia, other mechanisms possibly favor organization of macromolecular structures.

[Fabry's disease, glomerulonephritis with crescentic and granulomatous interstitial nephritis. Case of one family]

A 26-year-old female patient was admitted to the hospital because of fever of unknown origin and renal failure. Diagnosis of Fabry's disease, extracapillary proliferative (crescentic) glomerulonephritis and granulomatous interstitial nephritis was made by histological, immunohistochemical and electron microscopical diagnosis in a kidney biopsy and confirmed by further investigations. Years ago the brother of the patient had a kidney biopsy diagnosed as metabolic disease. The re-evaluation of this biopsy confirmed Fabry's disease while in this patient an association with tubulointerstitial nephritis occurred. To our knowledge this is the first family with two members having Fabry's disease combined with further kidney diseases.

Expression of drug resistance related proteins in sarcomas of the pulmonary artery and poorly differentiated leiomyosarcomas of other origin

Sarcomas are known to develop resistance to current chemotherapeutic strategies, displaying a multidrug-resistant phenotype. Mechanisms involved in drug resistance include reduced cellular drug accumulation, drug detoxification as well as alterations in drug target specificity. In seven sarcomas of the pulmonary artery (SPA) and ten leiomyosarcomas of other origin, we studied the immunohistochemical expression of P-glycoprotein (P-gp), multidrug-resistance protein (MRP), lung resistance protein (LRP), metallothionein (MT) and topoisomerase IIalpha. Upregulation was found in tumour cells for P-gp but not for MRP in SPA and other leiomyosarcomas. Topoisomerase IIalpha was expressed at high levels in tissue of primary tumours as well as recurrent tumours. Both P-gp and topoisomerase IIalpha were present in numerous tumour-associated vessels. LRP was expressed at high levels in SPA but to a lesser extent in the other leiomyosarcomas. MT was expressed at low levels but was markedly present at the border of necrosis. The overall survival and the relapse-free survival did not correlate with the expression of these factors. There was no significant relationship between treated and non-treated patients with respect to the expression of the examined molecules. P-gp, but not MRP, may play a role in the development of drug resistance. P-gp, LRP and topoisomerase IIalpha contribute to drug resistance through expression in tumour-associated vessels. Unique high levels of topisomerase IIalpha reflect the high proliferation rate of these tumours. MT seems to serve as a detoxifying agent of metabolites at the border of necrosis. Our findings underline the fact that multiple factors contribute to chemoresistance and that examination of a spectrum of relevant molecules is probably necessary to plan the best therapy.

Helicobacter pylori genotyping in gastric adenocarcinoma and MALT lymphoma by multiplex PCR analyses of paraffin wax embedded tissues

BACKGROUND

Gastric infection with Helicobacter pylori is the major cause of chronic active gastritis and is associated with the pathogenesis of peptic ulcer and gastric carcinoma. Gastric mucosal damage involves both host and H pylori dependent factors, such as the presence of the cag pathogenicity island and allelic variations of the vacA and iceA genes.

AIMS

To evaluate the association of these virulence factors with the development of gastric malignancies, a retrospective study was performed on archived tissue routinely obtained for diagnostic histopathology.

METHODS

DNA was extracted from formalin fixed, paraffin wax embedded gastric tissue sections of 93 patients with chronic active gastritis (n = 39), adenocarcinoma (n = 28), or mucosa associated lymphoid tissue (MALT) lymphoma (n = 24). The extracted DNA was used to perform a polymerase chain reaction based, simultaneous analysis of the following: (1) cagA status, (2) allelic variation of the iceA genes (iceA1, iceA2), allelic variation of the signal peptide (s1a, s1b, s2) and the midregion (m1, m1a, m2) of the vacA gene.

RESULTS

The iceA1 gene showed a 3.6 fold and the vacA s1a variant a 4.2 fold higher prevalence in gastric adenocarcinoma than in gastritis. The combined presence of both the vacA s1a and iceA1 genes had a 5.6 fold higher frequency in adenocarcinoma. The vacA m2 allele was the predominant subtype in MALT lymphoma and the combination of the vacA m2 subtypes with the vacA s1 and the iceA1 variants occurred in MALT lymphoma nearly five times more often than in chronic active gastritis.

CONCLUSIONS

Certain H pylori subtype combinations possess a differentiating and predictive value for the development of gastric adenocarcinoma and MALT lymphoma.

Massives lokalisiertes Lymphödem - eine seltene Entität

Massive localized lymphedema is a rare disease. Only a few cases have been described in the literature. These monstrous pseudotumors of the subcutis are mostly localized in the inguinal region or at the lower extremity. These tumors often show a slow growth for many years. Besides hernias, lipomatous tumors must be distinguished. The therapy of choice is the excision of the tumor. Relapse is not uncommon in the few cases described in the literature so far. The diagnostic procedure and therapy of an 48-year-old women with a massive localized lymphedema weighing about 22 kg are demonstrated and discussed.

Differential adhesion of polymorphous neutrophilic granulocytes to macro- and microvascular endothelial cells under flow conditions

OBJECTIVE

As one of the important active barriers in the human organism, endothelial cells (EC) play a central role in the biological reaction to a variety of stimuli, e.g. during the induction and regulation of inflammation, as well as in the reaction to transplantation and biomaterial implantation. In the study of endothelial function, the most widely used in vitro model is that of human umbilical vein EC (HUVEC), i.e. an EC type of embryonic and macrovascular origin. However, many of the important pathological processes occur at microvascular level, thus questioning the validity of the HUVEC model. Moreover, the morphological and functional heterogeneity of the endothelium in the various organs, e.g. kidney, liver and lung, must be taken into consideration. The purpose of the present study was to use a dynamic cell culture system to compare the reactions of HUVEC and human pulmonary microvascular EC (HPMEC) to pro-inflammatory stimulation.

METHODS

HUVEC and HPMEC in monolayer culture were stimulated by tumor necrosis factor-alpha (TNFalpha) in a parallel-plate flow chamber. Short- (4 h) and long-term (12 h) stimulation were compared. As a functional parameter, the adhesion of human peripheral blood polymorphonuclear granulocytes (PMN) to EC was quantitated both under venous and arterial flow conditions.

RESULTS

Short-term (4 h) TNFalpha stimulation and venous flow conditions elicited a 32% higher PMN adhesion to HPMEC compared with HUVEC, whereas under arterial flow conditions no statistically significant differences were found. Following longer-term (12 h) TNFalpha stimulation, PMN adhesion to HPMEC was 65% higher than to HUVEC under venous flow. Under arterial flow no differences were detected.

CONCLUSION

The present results provide new data on the heterogeneity of the endothelium and affect a central element in microvascular pathology, namely granulocyte-endothelial interactions. Moreover, this paper emphasizes the necessity to evaluate the in vitro models of the endothelium with respect to the extrapolation to the situation in vivo.

Characterisation of the cell type-specificity of collagenase 3 mRNA expression in comparison with membrane type 1 matrix metalloproteinase and gelatinase A in the synovial membrane in rheumatoid arthritis

OBJECTIVE

To study the pattern and cell type-specificity of collagenase 3, membrane-type 1 matrix metalloproteinase (MT1-MMP), and gelatinase A mRNA expression in the synovial membrane in rheumatoid arthritis (RA).

METHODS

The mRNA expression of collagenase 3, MT1-MMP, and gelatinase A was characterised by northern blot analysis, reverse transcriptase-polymerase chain reaction, and in situ hybridisation. In situ hybridisation was performed in combination with the immunohistochemical detection of cell type-specific antigens.

RESULTS

Synovial membrane specimens from 19 of 21 patients with RA expressing collagenase 3 mRNA were positive for MT1-MMP and gelatinase A mRNA. In control samples from patients without destructive inflammatory joint diseases collagenase 3 mRNA was not expressed and only in two of seven cases was a coexpression of MT1-MMP and gelatinase A mRNA detected. Fibroblast-like cells of the synovial membrane were found to be the predominant source of collagenase 3, MT1-MMP, and gelatinase A mRNA expression in lining and sublining layers as well as at the synovial membrane-cartilage interface. Additionally, the expression of MT1-MMP mRNA was detected in endothelial cells. Collagenase 3 mRNA expression was found in about 5% of CD68 positive macrophages.

CONCLUSIONS

Collagenase 3 mRNA is expressed simultaneously with MT1-MMP and gelatinase A mRNA in fibroblast-like cells of the synovial membrane in RA. These results suggest (a) a broad extracellular proteolytic potential of fibroblast-like cells and (b) an important role of cell surface associated procollagenase 3 activation by MT1-MMP and gelatinase A for cartilage degradation by invading fibroblast-like cells.

[Fulminant course of diffuse alveolar hemorrhage in systemic lupus erythematosus--a case report]

A 31-year old male patient had suffered from systemic lupus erythematosus (SLE) for 21 years. During the last 8 years he exhibited no clinical symptoms and did not receive any medical SLE treatment. He was admitted with a two-day history of dyspnea and fever. Laboratory studies revealed microcytic anemia and elevated levels of inflammation markers. Chest X-ray showed pulmonary infiltrates. The respiratory status rapidly deteriorated and the patient died 16 hours after admission. An autopsy was performed and diffuse alveolar hemorrhage in all parts of the lungs were seen, which was confirmed by microscopic examination. In contrast, lung histology did not show evidence of infection or inflammatory lesions. Additionally, membranous glomerulonephritis could be identified by light and electron microscopy. Diffuse alveolar hemorrhage (DAH) and concomittant lupus nephritis as manifestations of the known SLE were diagnosed. Acute pulmonary hemorrhage was determined as the cause of death. DAH is a rare, but serious manifestation of SLE. The diagnosis is difficult since the occurrence is abrupt and both symptoms and histology of the lesion are non-uniform and unspecific. The present case demonstrates that DAH also develops in patients that have not had clinical symptoms for several years. Since the early diagnosis is essential for the outcome, DAH should be considered in every case of SLE patients with severe pulmonary symptoms. Corticosteroids are the recommended form of therapy for this disorder.

Metastasizing chordoma of the lumbar spine

Chordoma is a dysontogenetic bone tumour that appears in the region of the axial skeleton. Its malignant transformation has been underestimated in the past, since the incidence of metastasis is disputed. This paper describes a chordoma of the fifth lumbar vertebra, which at first was monolocular, but in the course of the disease led to a diffuse metastasis of the spine. Specific histological findings and the differential diagnosis of the chordoma are discussed, as well as previous descriptions in the literature relating to course, diagnosis, and therapy.

Anderson-Fabry disease: clinical manifestations of disease in female heterozygotes

Anderson-Fabry disease is a rare, X-chromosomal lipid storage disorder caused by a deficiency of lysosomal alpha-galactosidase A. Clinical manifestations of Anderson-Fabry disease include excruciating pain in the extremities (acroparaesthesia), skin vessel ectasia (angiokeratoma), corneal and lenticular opacity, cardiovascular disease, stroke and renal failure, only renal failure being a frequent cause of death. Heterozygote female carriers have often been reported as being asymptomatic or having an attenuated form of the disease. To evaluate the spectrum of clinical signs in heterozygotes, a comprehensive clinical examination was performed on 20 carriers of Anderson-Fabry disease. This revealed that, in addition to the skin manifestation, various other clinical manifestations of the disease are present, including acroparaesthesia, kidney dysfunction, cerebrovascular disease, and gastrointestinal and heart problems. It therefore appears that Anderson-Fabry disease affects both hemizygotes and heterozyotes and therefore should be considered to be an X-linked dominant disease.

Expression of matrix-degrading cysteine proteinase cathepsin K in cholesteatoma

Cholesteatoma is a nonneoplastic lesion of the middle ear space or mastoid that is histologically characterized by a progressive bone erosion of the ossicles and surrounding bone. Several matrix-degrading enzymes have been implicated as mediators of this bone erosion. Because the novel cysteine proteinase cathepsin K has been shown to play a central role in bone resorption, we examined the expression of this enzyme in tissue specimens of cholesteatoma. Tissue specimens of 9 patients with cholesteatoma were obtained during middle-ear surgery. Expression of cathepsin K mRNA was determined by RT-PCR using specific primers. Immunohistochemical analysis of cathepsin K protein expression in tissue sections was performed by using the streptavidin-alkaline phosphatase technique. Expression of both cathepsin K mRNA and protein was detected in areas affected by cholesteatoma, whereas specimens of nonaffected ear cartilage and surrounding tissue were not positive. In addition, cathepsin K was detected in numerous multinucleated giant cells, particularly osteoclasts at the site of bone degradation. In contrast, keratinized squamous epithelium was negative for cathepsin K. These data demonstrate that the matrix-degrading cysteine proteinase cathepsin K may be involved in bone erosion in cholesteatoma. Strong expression of this collagenolytic enzyme in osteoclasts suggests that these cells are mainly involved in cathepsin K-mediated bone destruction.

[The frozen shoulder. Arthroscopy, histological findings and transmission electron microscopy imaging]

INTRODUCTION

During a period of 17 months (February 1998 to July 1999) arthroscopy was performed in 172 patients because of pathologic changes of the shoulderjoint.

METHODS

From the history and clinical examination, only eleven patients fulfilled the criteria for primary frozen shoulder set up by Lundberg in 1969. Further investigations such as X-ray examination, ultrasonography and MRI scanning showed no changes that could explain the clinical picture of shoulder stiffness. Of the eleven patients with frozen shoulder. additionally in two cases hyperthyroidism, in five cases diabetes type II and in a further five cases a Dupuytren's contracture could be found. Based on the operative procedure, recently published by Habermeyer, Ogilvie and Warner we carried out an arthroscopic arthrolysis of the stiff shoulder.

RESULTS

Diagnostic arthroscopy demonstrated synovialitis in the upper and ventral areas of the joint in over 50% of the patients. Interestingly, intraarticular adhesions were not found in any of our patients; in particular, no obliteration of the axillary recess could be seen. Altogether, in seven of the eleven patients with frozen shoulder, a notably contracted biceps tendon was found which obviously applied increased the force on the humeral head, as in corresponding areas cartilage damage could be demonstrated arthroscopically. A significant increase in fibroblast cells next to loose areas of connective tissue could be shown in histological examinations of biopsies of the capsule in the rotatorer interval. We noted thickened vessel walls and an augmentation of the synovial surface, whereas typical inflammation could not be demonstrated in any of the histological specimens. In the transmission-electron microscope examination (TEM) of samples taken from the capsule in the rotatorer interval, structural changes in collagenous tissue were discernible. Typically, a loss of fibril order and a twisting of collagen fibrils were seen. This twirling led to an up to fourfold diameter of the collagenous fibrils, whereby thin, elastin-like filaments could be seen between the thickened bundles of collagen fibrils.

CONCLUSION

In stage of the primary frozen shoulder exclusive fibrosis of the joint capsule was found. Electronmicroscopic twists of collagen fibrills were marked.

Osteopontin expression in primary sarcomas of the pulmonary artery

Primary tumors of the great vessels (aorta, pulmonal artery, and inferior vena cava) are rare and represent in most cases vascular leiomyosarcomas. Furthermore, there also exists a group of sarcomas arising from the intima, known as intimal sarcomas, associated with early metastasis and a very poor prognosis. Osteopontin (OPN) is an extracellular matrix protein that binds to alphav integrins, thereby promoting cell attachment, chemotaxis, and signal transduction. The reported association of OPN with malignancy and metastasis prompted us to examine the expression of this protein in seven sarcomas of the pulmonary artery. Strong OPN-specific staining could be detected in tumor cells and the adjacent extracellular matrix. Using a double labeling procedure, proliferating cells showed a strong positive reaction with antibodies against OPN. In addition, this protein could be demonstrated in the cytoplasm of macrophages. CD44, a putative receptor of OPN, was expressed on the cellular surface of tumor-associated lymphocytes. The expression of OPN in macrophages and tumor cells indicates that this molecule could possibly mediate cellular adhesion of both cell types in pulmonary sarcomas. The detection in the extracellular matrix shows that OPN is actively secreted and may interact with the corresponding receptor, CD44, on the surface of lymphocytes. Although the function of OPN is not yet fully understood, our data indicate that strong expression of this molecule in poorly differentiated sarcomas could play a role in the progression of malignancy and metastasis as described previously for carcinomas.

[A benign form of osteopetrosis. Case report]

Osteopetrosis is a disease in which a disturbance in the resorption of bone formed by endochondral ossification takes place. The cause of the osteoclast insufficiency is unknown. In the literature, the etiology of the disease is discussed in relation to the complete absence of cathepsin K synthesis, a cysteine protease. In our case report, we demonstrated cathepsin K expression in the osteoclast cells of the benign form of osteopetrosis. We also found the macrophage marker CD 68 in these osteoclast cells, whereas other mononuclear phagocytic cells were not present in the vicinity of osteoclasts. The inhibition of osteoclast cells by phagocytes is unlikely.

Temporary warm ischaemia, 5/6 nephrectomy and single uranyl nitrate administration--comparison of three models intended to cause renal fibrosis in rats

In patients the progression of pathologic renal processes after the treatment of primary disease is a problem of increasing importance and therapeutic strategies are insufficient till now. The aim of this paper was to search for rat models of interstitial fibrosis as a basis for testing therapeutic strategies to prevent end-stage renal failure. Experiments were done on adult female Wistar rats (Han:Wist) to investigate long-term consequences of temporary warm ischaemia, 5/6 nephrectomy (5/6 NX) and single uranyl nitrate (UN) administration (0.3 or 0.5 mg/ 100 g body wt. intraperitoneally). Observation time was 20 weeks after injury in each group. Creatinine clearance, urinary protein excretion and hydroxy-proline (OH-proline) concentration in renal tissue were measured and light microscopic investigations were done to characterise both quality and time course of long-term renal damage in relation to matched control animals. Temporary warm ischaemia and 5/6 NX did not cause any fibrotic changes during the 20 weeks observation period. The higher UN dose led to decreased creatinine clearance, increased urinary protein excretion and enhanced OH-proline concentration in renal tissue. Morphologic investigations showed fibrotic areas containing strongly dilated and atrophic tubules with thickened basal membranes. These effects can be seen from week four after UN administration up to the end of the observation period. In conclusion, administration of one single dose of UN is a simple procedure to induce interstitial renal fibrosis as an experimental model to investigate therapeutic strategies for their prevention.

Expression of apoptosis-related proteins, p53, and DNA fragmentation in sarcomas of the pulmonary artery

BACKGROUND

Apoptosis is a common feature in a variety of pathologic conditions. Induction of apoptosis through apoptotic stimuli such as, chemotherapy or radiation, presents new insights into tumor biology and therapy. In particular, members of the Bcl-2 family as well as the Fas system are known to be involved in the regulation of apoptosis in different tumor entities.

METHODS

In the current study, the expression of the apoptosis-related molecules p53, Bax, Bcl-2, Fas (CD95), Fas-Ligand and perforin was examined in 7 patients with a sarcoma of the pulmonary artery. Furthermore, the TUNEL-method for the detection of apoptotic cells was applied as well as sequencing of the p53 gene.

RESULTS

In the TUNEL assay, approximately 10% of the sarcoma cells displayed DNA fragmentation. In addition, Bax was expressed in tumor cells. Accumulation of p53 was evident in 4 of 7 patients (pAB 240 antibody), and 2 of them were positive for the pAB 1801 antibody. Only 1 case had a point mutation in Exon 5 of the p53 sequence. A few tumor cells showed a double labeling of Bax and p53. Bcl-2 could be detected only in tumor-associated lymphocytes. Finally, several lymphocytes could be stained with perforin, but none of the specimens showed a reactivity for Fas or Fas-Ligand.

CONCLUSION

The expression of Bax indicated a possible role of this molecule in programmed cell death in pulmonary sarcomas. The limited coexpression of Bax and p53 suggested that induction of Bax can occur independently of p53. The detection of perforin in lymphocytes suggested a possible role for this molecule in apoptosis of the sarcoma cells. In contrast, the Fas system did not seem to play an essential role in sarcomas of the great vessels.

Detection of mRNA by non-radioactive direct primed in situ reverse transcription

There are various techniques to detect mRNA in tissue specimens. Among these in situ hybridization is widely applied, and for the detection of small quantities of RNA in situ reverse transcriptase polymerase chain reaction (in situ RT-PCR) has been applied. Furthermore in situ transcription, where signal is produced by direct incorporation of labeled nucleotides during production of a cDNA by reverse transcription, has been shown by a few investigators. We present a non-radioactive in situ reverse transcriptase (in situ RT) protocol which is at least as sensitive as in situ hybridization but avoids probe production and long procedures of preincubation, incubation, and washing. Digoxigenin-labeled UTP is incorporated into a cDNA produced by in situ reverse transcription of mRNA. This method is combined with the fast and sensitive immunogold-silver detection system allowing demonstration of the mRNA within 7 h compared to days in the case of in situ hybridization. Contrary to in situ RT-PCR this new method of in situ RT has no background problems due to non-specific amplification or diffusion of the reaction product.

[Drug therapy of carcinoids of the gastrointestinal tract]

Carcinoid tumors are rare and slowly growing neuroendocrine tumors of the foregut, midgut and hindgut. Drug therapy is of special importance in patients with inoperable metastasising disease. This palliative therapy is aimed at reduction of the hormone-dependent symptoms and inhibition of tumor growth. Somatostatin analogues, alpha-interferon and various chemotherapeutic agents are used for this purpose. Drug therapy can be supplemented by surgical and radiological intervention through interdisciplinary cooperation of the surgeon, radiologist, endocrinologist and gastroenterologist.

Cathepsin K in aseptic hip prosthesis loosening: expression in osteoclasts without polyethylene wear particles

OBJECTIVE

To investigate the expression of the bone matrix degrading cysteine proteinase cathepsin K and to determine the colocalization of cathepsin K with polyethylene (PE) particles in tissue specimens of patients with aseptic hip prosthesis loosening (AHPL).

METHODS

The expression of cathepsin K was studied by immunohistochemistry in tissue specimens of 9 patients with aseptically loosened acetabular components of failed cementless total hip replacements. The expression of cathepsin K was compared to that of the macrophage marker CD68 by serial section analysis. Double labeling of the expression of cathepsin K or CD68 by immunohistochemistry and of PE particles by modified Oil Red staining method was performed.

RESULTS

Cathepsin K could be predominantly detected in osteoclasts attached to the bone tissue, while only a few (CD68+) mononuclear and multinucleated foreign body giant cells (MGC) were positive for this enzyme. By double labeling with Oil Red staining we found the majority of CD68 positive cells of the periprosthetic tissue that were colocalized with PE particles. However, cathepsin K-expressing osteoclasts could not be stained with Oil Red.

CONCLUSION

The present data suggest that in AHPL neither mononuclear cells nor MGC but rather osteoclasts are mainly involved in cathepsin K mediated bone matrix destruction. Using double labeling of immunohistochemistry and Oil Red staining we observed that the cathepsin K-expressing osteoclasts did not include PE particles.

Expression of cysteine proteinases cathepsins B and K and of cysteine proteinase inhibitor cystatin C in giant cell tumor of tendon sheath

The expression of cysteine proteinases cathepsins B and K and of the endogenous inhibitor of cysteine proteinases, cystatin C, was investigated in tissue specimens of patients with giant cell tumor of tendon sheath (GCTTS). Expression of both enzymes was examined by immunohistochemistry in tissue specimens of 14 patients with GCTTS. Applying double-labeling techniques, the coexpression of cathepsin B and its major endogenous inhibitor cystatin C was additionally studied. Cells expressing the respective proteins were further characterized with the macrophage markers HAM56 and anti-CD68 (clone PG-M1). Cathepsin B could be detected in numerous HAM56-positive mononuclear cells (MC), but only in very few giant cells (GC). In contrast, cathepsin K was predominantly identified in GC that were also strongly immunoreactive for cystatin C and CD68. Coexpression of cathepsin B and cystatin C occurred only in a few MC. The strong expression of both cathepsin B and K suggests that in GCTTS, bone erosion might be mediated not only by pressure of the proliferative tissue, but also by matrix-degrading cysteine proteinases. Because previous studies showed that osteoclasts express high levels of CD68, cathepsin K, and cystatin C but not of cathepsin B, our study contributes to the view that GC of GCTTS and osteoclasts are closely associated.

Renal tubular dysgenesis (RTD) - an important cause of the oligohydramnion-sequence. Report of 3 cases and review of the literature

Renal tubular dysgenesis (RTD) is a disorder characterized by neonatal renal failure and regular gross renal architecture, although the histological features of immature and shortened proximal tubules lead to neonatal death. The pathogenesis of this condition includes a congenital familial condition, a twin-twin transfusion syndrome, and an angiotensin-converting enzyme inhibitor intake by the mother. The clinical picture shows an association with oligohydramnia, pulmonary hypoplasia, and skull ossification defects. In the present paper, we report the occurrence of RTD in three infants of a consanguinous couple and compared our data with those of the literature. Our data confirm that late second trimester demonstration of oligohydramnion, with structurally normal kidneys and with or without skull ossification defects, allows the diagnosis of renal tubular dysgenesis, which, however, has to be confirmed by histological and immunohistological examinations of the kidney.

Coexistence of Fabry's disease and necrotizing and crescentic glomerulonephritis

The coexistence of Fabry's disease, an X-linked hereditary disease, and other renal diseases, has rarely been described in the same patient. Combined Fabry's disease and pauci-immune necrotizing and crescentic glomerulonephritis (NCGN) is hitherto unreported. We present the clinical and pathologic data of two patients with combined Fabry's disease and NCGN. Both patients presented with fevers of unknown origin and progressive renal insufficiency, however, lacked any other pathognomic signs of Fabry's disease such as acroparesthesias, dyshidrosis, and cutaneous angiokeratomas. The possible pathogenic mechanisms and causal relationship between the two disease processes are discussed.