[Participation and support of clinical studies and other scientific investigations. Statement of the German Society for Pathology]. / Beteiligung und Unterstützung klinischer Studien und anderer wissenschaftlicher Untersuchungen. Stellungnahme der Deutschen Gesellschaft für Pathologie e. V.

Clinical studies and preclinical investigations are essential in order to test new therapies and diagnostics with the aim of sustained improvement in the treatment of patients. Fortunately, the number of clinical studies is continuously increasing and pathology and tissue-based research are included more often. The German Society for Pathology (DGP) and the pathologists it represents want to and can support this process and our clinical partners as best as possible as an equal partner. With our technologies and our specific expertise we can make a substantial contribution to the quality and the success of preclinical investigations, clinical studies and implementation of the results into clinical pathological diagnostics. In order to support this process the DGP has formulated a statement on the participation and support of clinical studies and other scientific investigations.

Evaluation of antimicrobial effects of novel implant materials by testing the prevention of biofilm formation using a simple small scale medium-throughput growth inhibition assay.

Staphylococcal colonization of implants is a serious complication of orthopaedic surgery. Anti-infectious modification of implant surfaces may serve to prevent bacterial colonization. The authors set out to develop an in vitro test system for the analysis of prevention of biofilm formation by Staphylococcus epidermidis and Staphylococcus aureus on implant materials. Biofilm growth was monitored over 10 days on titanium disks in order to develop appropriate test parameters. Bacterial cell counts following ultrasonic treatment of the colonized samples were compared with scanning electron microscope images of the specimens. Copper ion containing surfaces (ie copper [Cu] and inter-metallic Ti-Cu films) were used for growth inhibition assays: copper ion releasing specimens led to reduced bacterial numbers in biofilms and decreased bacterial persistence in the model used. The assay used represents an inexpensive and quick in vitro screen for the antibacterial effects of novel implant surface materials.

[Principles of tribological analysis of endoprostheses]. / Grundlagen zur tribologischen Analyse von Endoprothesen.

For the tribological characterization of artificial joints, various experimental methods are currently available. However, the in vitro test conditions applied are only comparable in a limited way and transferability to the in vivo situation is also restricted. This is due to the different wear simulation concepts used and partly insufficient simulation of clinical worst case situations. In the present paper current scientific methods and procedures for tribological testing of artificial joints are presented. In addition, the biological effects of wear products are described enabling clinicians to challenge tribological studies and to facilitate specific interpretation of scientific results taking the clinical situation into account.

The evolution of the antimicrobial peptide database over 18 years: Milestones and new features.

The antimicrobial peptide database (APD) has served the antimicrobial peptide field for 18 years. Because it is widely used in research and education, this article documents database milestones and key events that have transformed it into the current form. A comparison is made for the APD peptide statistics between 2010 and 2020, validating the major database findings to date. We also describe new additions ranging from peptide entries to search functions. Of note, the APD also contains antimicrobial peptides from host microbiota, which are important in shaping immune systems and could be linked to a variety of human diseases. Finally, the database has been re-programmed to the web branding and latest security compliance of the University of Nebraska Medical Center. The reprogrammed APD can be accessed at https://aps.unmc.edu.

[Influence of acetabular cup design on the primary implant stability : an experimental and numerical analysis]. / Einfluss der Formgebung von künstlichen Hüftpfannen auf die primäre Verankerungsfestigkeit : Eine experimentelle und numerische Analyse.

BACKGROUND: An adequate primary stability and a subsequent stable osseous fixation (secondary stability) of artificial hip cups are required for long-term implant survival. The aim of this study was to analyse the design of cementless press-fit cups as an influencing factor of primary stability. MATERIAL AND METHODS: Different hemispherical and conical cup designs were analysed. The fixation stability of the cups was detected experimentally using a spongiosa and a cortical model based on artificial bone as well as a numerical simulation using a spongiosa model by pull-out and lever-out tests. In addition, the stress on the osseous cup cavity was determined in the finite-element analysis. RESULTS: All tested cup designs revealed higher fixation stability in the cortical bone model compared to the spongiosa model. The experimental tests did not show an increase of fixation stability with the conical cup profile in comparison to hemispherical cup profiles. CONCLUSION: Therefore, cementless press-fit cups with conical cup profile do not provide a higher primary stability in comparison to hemispherical cups. Moreover, the stress on the bone cavity was lower inserting the hemispherical cup profiles in contrast to the conical profiles.

Activation of matrix-metalloproteinase-2 and membrane-type-1-matrix-metalloproteinase in endothelial cells and induction of vascular permeability in vivo by human immunodeficiency virus-1 Tat protein and basic fibroblast growth factor.

Previous studies indicated that the Tat protein of human immunodeficiency virus type-1 (HIV-1) is a progression factor for Kaposi's sarcoma (KS). Specifically, extracellular Tat cooperates with basic fibroblast growth factor (bFGF) in promoting KS and endothelial cell growth and locomotion and in inducing KS-like lesions in vivo. Here we show that Tat and bFGF combined increase matrix-metalloproteinase-2 (MMP-2) secretion and activation in endothelial cells in an additive/synergistic manner. These effects are due to the activation of the membrane-type-1-matrix-metalloproteinase and to the induction of the membrane-bound tissue inhibitor of metalloproteinase-2 (TIMP-2) by Tat and bFGF combined, but also to Tat-mediated inhibition of both basal or bFGF-induced TIMP-1 and -2 secretion. Consistent with this, Tat and bFGF promote vascular permeability and edema in vivo that are blocked by a synthetic MMP inhibitor. Finally, high MMP-2 expression is detected in acquired immunodeficiency virus syndrome (AIDS)-KS lesions, and increased levels of MMP-2 are found in plasma from patients with AIDS-KS compared with HIV-uninfected individuals with classic KS, indicating that these mechanisms are operative in AIDS-KS. This suggests a novel pathway by which Tat can increase KS aggressiveness or induce vasculopathy in the setting of HIV-1 infection.

Expression of K13/v-FLIP gene of human herpesvirus 8 and apoptosis in Kaposi's sarcoma spindle cells.

BACKGROUND: Human herpesvirus 8 (HHV8) infection is associated with all forms of Kaposi's sarcoma (KS). The HHV8 genome locus ORFK13-72-73 (ORF = open reading frame) encodes proteins that may be important in HHV8-mediated pathogenesis, i.e., the latency-associated nuclear antigen (encoded by ORF73), viral-cyc-D (v-cyc-D), a viral homologue of cellular cyclin D (encoded by ORF72), and viral-FLIP (v-FLIP), a homologue of the cellular FLICE (Fas-associated death domain-like interleukin 1 beta-converting enzyme) inhibitory protein (encoded by ORFK13; is an inhibitor of apoptosis [programmed cell death]). Through differential splicing events, this locus expresses individual RNA transcripts that encode all three proteins (tricistronic transcripts) or just two of them (v-FLIP and v-cyc-D; bicistronic transcripts). We examined expression of these transcripts in KS tissues. METHODS: We collected tissues from patients with KS of different stages. By use of an optimized in situ hybridization procedure, we examined different ORFK13-72-73 locus transcripts in HHV8-infected cells in skin lesions and in one adjacent lymph node. Apoptosis in KS lesions was determined by use of an in situ assay. RESULTS AND CONCLUSIONS: Our results indicate the following: 1) Transcripts from the ORFK13-72-73 locus appear to be spliced differentially in latently infected KS cells in skin lesions and in HHV8-infected cells in lymph nodes; specifically, ORFK13-ORF72 bicistronic transcripts were expressed abundantly in KS cells, whereas ORFK13-ORF72-ORF73 tricistronic transcripts were detected only in lymph node cells. 2) Sequences encoding the antiapoptotic protein v-FLIP are expressed at very low levels in early KS lesions, but expression increases dramatically in late-stage lesions. 3) The increase in expression of v-FLIP-encoding transcripts is associated with a reduction in apoptosis in KS lesions. IMPLICATIONS: These data suggest that functional v-FLIP is produced in vivo and that antiapoptotic mechanisms may be involved in the rapid growth of KS lesions, where only a few cells undergoing mitosis are generally observed.

Identification of interleukin-1 and platelet-derived growth factor-B as major mitogens for the spindle cells of Kaposi's sarcoma: a combined in vitro and in vivo analysis.

By means of a combined in vitro and in vivo analysis we provide evidence that IL-1 beta and PDGF-B, but not OSM (oncostatin M) or IL-6, are major mitogens for the spindle cells of Kaposi's sarcoma (KS) in vivo. PDGF-B and IL-1 beta stimulated proliferation of cultivated KS spindle cells in vitro. Analysis of gene expression in vivo revealed that both factors as well as the PDGF beta-receptor are present in KS lesions. By contrast, IL-6 had no effect and OSM inhibited proliferation of cultivated KS spindle cells. Again, the effect of these factors on cultivated KS spindle cells in vitro was reflected by the gene expression observed in KS lesions in vivo. Neither the expression of IL-6 receptor nor of OSM could be detected in KS lesions by in situ hybridization. Moreover, in situ hybridization revealed an identical pattern of gene expression in cultivated KS spindle cells and KS spindle cells in vivo with respect to the above-mentioned cytokines [PDGF-B, IL-1 beta, IL-1 alpha, IL-6, OSM] and their receptors [PDGF beta-receptor, gp130, IL-6 receptor, leukemia inhibitory factor (LIF) receptor]. This further supported the suitability of cultivated KS spindle cells as an in vitro model in order to determine which cytokines may activate proliferation of KS spindle cells in vivo.

Human herpesvirus-8 and Kaposi's sarcoma: relationship with the multistep concept of tumorigenesis.

Kaposi's sarcoma (KS) develops through discrete inflammatory-angiogenic stages of polyclonal nature (early-stage lesions) to monomorphic nodules of spindle-shaped cells that can be clonal (late-stage lesions) and resemble true sarcomas. Molecular and epidemiological studies indicate that development of KS is tightly associated with infection by the human herpesvirus-8 (HHV-8). However, only individuals with specific conditions of immunodysregulation develop KS. In these individuals the systemic and tissue increase of Th-1-type cytokines (IC) reactivate HHV-8 infection, leading to increased viral load, antibody titers, and an expanded cell tropism that precedes the clinical appearance of KS. Recruitment of the virus into tissues by infected monocytes and other cell types is facilitated by the endothelial cell activation due to IC. In clinical lesions, HHV-8 infection increases with lesion stage and in late-stage lesions most of the spindle cells are latently infected, whereas only few lyrically infected cells are present, suggesting that latent genes may have a role in the transformation of the early inflammatory-hyperplastic lesion into a real sarcoma. The development of tumors, however, is regulated through a multistep process based on the acquisition by cells of several different capabilities leading to malignant growth. Here we review the available data on the expression of HHV-8-encoded genes in primary KS lesions and, in view of their biological activity, analyze their potential function in different steps of tumorigenesis. By this pragmatic approach interesting insights into potential key functions of HHV-8-encoded genes are found and steps of potential cooperativity with other viral factors (HIV-1-Tat) in the pathogenesis of KS are identified.

Ultrasound as a tool to evaluate remission of cutaneous Kaposi's sarcoma.

OBJECTIVE: To evaluate ultrasound measurement of Kaposi's sarcoma (KS) tumour volume for follow-up during therapy. Two-dimensional evaluation of size and description of gross alteration (for example, colour, nodularity, resolution) was used to assess treatment of KS. Flattening of palpable cutaneous KS lesions during anti-KS therapy has not been quantified objectively by a reliable method. METHODS: In six patients with advanced AIDS and KS, a total of 17 cutaneous lesions were evaluated prospectively by ultrasound and surface measurements. KS lesions were examined histologically before and after 12 weeks of chemotherapy with liposomal doxorubicin. RESULTS: In comparison with size reduction, volume measurement showed a more pronounced reduction of tumour volume. The mean tumour volume was reduced by 94% from 451 mm3 +/- 655 mm3 to 66 mm3 +/- 165 mm3 at week 12 (P < 0.001). Histological evaluation of lesions no longer detectable by ultrasound after therapy showed abundant siderophages but no increase in spindle cells and no mitoses. CONCLUSIONS: Our findings suggest that ultrasound is a useful method with which to follow growth and remission of cutaneous KS. In contrast, pigmentation due to iron deposition is unaffected by chemotherapy because, despite histological remission, pigmentation can persist. Though ultrasound cannot replace histologic evaluation for complete response, we suggest the use of ultrasound assessment, thus introducing a more objective criterion than subjective rating of nodularity.

In situ hybridization of mitochondrial DNA in the heart of a patient with Kearns-Sayre syndrome and dilatative cardiomyopathy.

Previous studies have revealed cytochrome-c-oxidase-deficient cardiomyocytes and the 4,977 base pair deletion ("common deletion") of mitochondrial DNA (position 8,482-13,459) in the heart of a patient with dilatative cardiomyopathy and Kearns-Sayre syndrome. In the present investigation the co-localization of the enzymatic and genomic defects was studied. In situ hybridization of mitochondrial DNA (mtDNA) revealed different hybridization patterns in the cytochrome-c-oxidase-deficient cells: (1) a selective reduction of the hybridization signal with an mtDNA probe recognizing the common deletion, indicating predominance of the deleted over the nondeleted mtDNA molecules in the cytochrome-c-oxidase-deficient cells; (2) a reduced hybridization signal with different mtDNA probes, indicating depletion of mtDNA; and (3) normal hybridization signals with different probes in single cytochrome-c-oxidase-deficient cardiomyocytes. These results indicate that different mechanisms may co-exist in Kearns-Sayre syndrome and may lead to defective respiratory chain function. The question of the pathogenetic interrelationship is discussed.

HIV-related parotid lymphoepithelial cysts. Immunohistochemistry and 3-D reconstruction of surgical and autopsy material with special reference to formal pathogenesis.

Whether lymphoepithelial cysts in the parotid glands in HIV-infected patients develop from pre-existing salivary gland inclusions in intraparotid lymph nodes or from a lymphoepithelial lesion of salivary parenchyma is unclear. To examine their pathogenesis we performed a histological and immunohistochemical study of salivary specimens from 100 AIDS patients in different disease stages. There is a continuous morphological spectrum of changes within the salivary parenchyma, starting with lymphoid stroma infiltration and evolving to characteristic lymphoepithelial duct lesions with a immunohistochemically proven basal cell proliferation and to fully developed ductal cysts. Involvement of myoepithelial cells-postulated in comparable Sjögren-associated duct lesions-is excluded immunohistochemically. Computer-assisted 3-D reconstructions confirm an association of the cysts with the intralobular duct system. Our study disproves the prevailing hypothesis, which suggests that the lymphoid cell compartment of HIV-associated lymphoepithelial cysts stems from pre-existing intraparotid lymph nodes. The results demonstrate that a secondary lymphatic infiltration of salivary parenchyma provokes a lymphoepithelial lesion of striated ducts with basal cell hyperplasia. The frequent progression to a multifocal cystic lymphoepithelial lesion may be supported by ductal compression through a high degree of lymphofollicular hyperplasia in early disease.

Lymphoepithelial duct lesions in Sjögren-type sialadenitis.

It is not clear, whether the so-called basal cells of the salivary striated ducts are an independent cell-type distinct from myoepithelial cells, making characterization of the cell proliferation typical of the duct lesions in Sjögren-type sialadenitis/benign lymphoepithelial lesion (BLEL) difficult. An immunohistochemical investigation including different cytokeratin subtypes, alpha-actin, Ki-67 and Bcl-2 was directed at the epithelial cytoskeleton in normal parotid parenchyma (n=8), BLEL (n=12), HIV-associated lymphoepithelial cysts (n=8) and palatine tonsils (n=8). There are profound morphological and functional differences between basal and myoepithelial cells in the normal salivary duct. Development of duct lesions in BLEL arises from basal cell hyperplasia of striated ducts with aberrant differentiation into a multi-layered and reticulated epithelium, characterized by profound alteration of the cytokeratin pattern. This functionally inferior, metaplastic epithelium is similar to the lymphoepithelial crypt epithelium of palatine tonsils. The often postulated participation of myoepithelial cells in duct lesions of Sjögren disease/BLEL cannot be supported. We regard the designations lymphoepithelial lesion and lymphoepithelial metaplasia as the most appropriate.

Expression of human herpesvirus-8 (HHV-8) encoded pathogenic genes in Kaposi's sarcoma (KS) primary lesions.

Transcription of six different HHV-8 specific mRNAs was examined in early- and late-stage KS primary lesions. Expression of the latency-associated T0.7 mRNA and of VP23 mRNA which is a specific marker of lytic/productive infection suggested that HHV-8 is secondarily recruited into the KS lesions by productively infected monocytes, macrophages. From these cells HHV-8 is transmitted to the KS spindle cells, which are latently infected. v-BCL-2, v-MCP-1 and v-IL-6 were not expressed in latently infected KS spindle cells, therefore the impact of these factors in KS pathogenesis appears to be low. By contrast, v-Cyclin D was highly expressed in almost all latently infected spindle cells and may therefore be an important factor triggering progression of late-stage KS lesions.

Distribution of basement membrane-associated heparan sulfate proteoglycan in idiopathic and AIDS-associated Kaposi's sarcoma.

In the present study we analyzed the immunohistochemical distribution of different major basement membrane (BM) components with special emphasis on the BM-associated heparan sulfate proteoglycan (HSPG) in early and late stages of Kaposi's sarcoma (KS), both of idiopathic and AIDS-associated origin. In early KS all BM components tested were found surrounding the small clefts of tumour vessels. Heparan sulfate proteoglycan showed the weakest and often fragmented pattern of staining. In the late, nodular sarcomatous form of KS individual tumour cells were surrounded by a BM composed of collagen IV, laminin and fibronectin, while heparan sulfate proteoglycan was not detectable in most cases. Neither between idiopathic and AIDS-associated KS nor between cutaneous and visceral lesions were significant differences in the staining pattern. Our findings of a rather selective expression of various BM-components and the known distribution in normal blood and lymphatic capillaries raises the hypothesis that KS-cells may be derived from cells of lymphaticovenous differentiation.

[Clinical studies and treatment of Karposi's sarcoma of the head and neck in AIDS patients]. / Clínica y terapéutica del sarcoma de Kaposi de localización cervicofacial en pacientes con síndrome de inmunodeficiencia adquirida.

Kaposi's sarcoma is the major neoplastic disease of HIV-infected patients in the head and neck regions. A clinical study realized at Ludwig-Maximilians University, München, uncover 25 homosexuals with KS out of 135 HIB-positive patients. Six of them showed a KS as initial manifestation of the syndrome. The KS was found principally in the palate (22 cases), oropharynx (12) and skin of the neck (11). Symptoms like swallowing or breathing problems occurred in nodular lesions of the mouth, pharynx or larynx, but no in the maculous type. Local laser and/or systemic (retrovir, interferon, chemotherapy) treatment was performed. CO2 and Nd:YAG laser-therapy showed a regression of the tumors and thus an improvement of quality of life could be achieved.

[Benign lymphoepithelial parotid cysts in patients infected with the human immunodeficiency virus]. / Quistes linfoepiteliales benignos parotídeos en enfermos infectados por el virus de la inmunodeficiencia humana.

This report describes four patients who presented with masses in the tail of the parotid gland and who were seropositive for antibody to the human immunodeficiency virus. Two had unilateral gland enlargement and the other two had bilateral disease. A characteristic cyst appearance and a benign lymphoepithelial infiltrate with cystic degeneration was found on the radiographic and the histological examinations, respectively. They were located peri- and intraparotid. Benign lymphoepithelial parotid cysts appear to be an early manifestation of pre-AIDS or AIDS-related complex. Surgical excision is recommended for therapy.

[Oral hairy leukoplakia in human immunodeficiency virus positive patients: clinical and etiopathogenic aspects]. / Leucoplasia verrucosa oral en pacientes positivos para el virus de la inmunodeficiencia humana: aspectos clíncos y etiopatogénicos.

Clinical and etiopathogenetic features of oral hairy leukoplakia in 5 patients positive for Human Immunodeficiency Virus were studied. Oral hairy leukoplakia were located on the lateral borders of the tongue and showed a corrugated/hairy aspect in all the cases. Histological examination showed hyperparakeratosis, acanthosis, hair like projection (n = 4) koilocyte-like-cells and moderate subepidermal inflammation. Immunohistochemistry revealed positive results for Epstein-Barr virus indicating an active replication of this virus within the epithelial cells of the stratum granulosum and upper stratum spinosum.

[Malignant otorhinolaryngological lymphomas associated with human immunodeficiency virus infection]. / Linfomas malignos otorrinolaringológicos asociados a la infección por el virus de la inmunodeficiencia humana.

Six instances of lymphoma occurring in homosexual male patients among 140 HIV-positive subjects attended at our Department of Otolaryngology were evaluated for clinical features, histopathologic features and Epstein-Barr virus (EBV) DNA. The histology of the patients was consistent with a Hodgkin's lymphoma, centroblastic lymphoma and four lymphoblastic lymphoma. High malignancy and nodal localization were characteristic of four non-Hodgkin's lymphoma, which carries a poor prognosis. The DNA in situ hybridization studies demonstrated the presence of EBV DNA sequences in the four lymphoblastic lymphoma.