Linking ATP and allosteric sites to achieve superadditive binding with bivalent EGFR kinase inhibitors

Bivalent molecules consisting of groups connected through bridging linkers often exhibit strong target binding and unique biological effects. However, developing bivalent inhibitors with the desired activity is challenging due to the dual motif architecture of these molecules and the variability that can be introduced through differing linker structures and geometries. We report a set of alternatively linked bivalent EGFR inhibitors that simultaneously occupy the ATP substrate and allosteric pockets. Crystal structures show that initial and redesigned linkers bridging a trisubstituted imidazole ATP-site inhibitor and dibenzodiazepinone allosteric-site inhibitor proved successful in spanning these sites. The reengineered linker yielded a compound that exhibited significantly higher potency (~60 pM) against the drug-resistant EGFR L858R/T790M and L858R/T790M/C797S, which was superadditive as compared with the parent molecules. The enhanced potency is attributed to factors stemming from the linker connection to the allosteric-site group and informs strategies to engineer linkers in bivalent agent design.

[Mental health care in French correctional facilities during the Covid-19 pandemic]

OBJECTIVE

The impact of the Covid-19 pandemic on the 11 million people currently incarcerated worldwide is the subject of many concerns. Prisons and jails are filled with people suffering from many preexisting medical conditions increasing the risk of complications. Detainees' access to medical services is already limited and overcrowding poses a threat of massive contagion. Beyond the health impact of the crisis, the tightening of prison conditions worries. On March 16, 2020, in France, the lockdown measures have been accompanied by specific provisions for prisons: all facilities have suspended visitations, group activities and external interventions. Over 10,000 prisoners have been released to reduce the prison population and the risk of virus propagation. These adjustments had major consequences on the healthcare system in French prisons. The objectives of this article are to describe the reorganization of the three levels of psychiatric care for inmates in France in the context of Covid-19 pandemic and to have a look at the impact of lockdown measures and early releases on mental health of prisoners.

METHODS

This work is based on a survey conducted in April 2020 in France among psychiatric healthcare providers working in 42 ambulatory units for inmates and in the 9 full-time inpatient psychiatric wards exclusively for inmates called "UHSAs" (which stands for "unités hospitalières spécialement aménagées", and can be translated as "specially equipped hospital units"). A review of the international literature on mental healthcare system for inmates during the Covid-19 epidemic has also been performed.

RESULTS

The Covid-19 epidemic has been rather contained during the period of confinement in French prisons but the impact of confinement measures on the prison population is significant. The three levels of psychiatric care for inmates have implemented specific measures to ensure continuity of care, to support detainees during Coronavirus lockdown and to prevent an infection's spread. Among the most important are: limitation of medical consultations to serious and urgent cases, creation of "Covid units", cancellation of voluntary psychiatric hospitalizations, reinforcement of preventive hygiene measures and reshuffling of medical staff. Prolonged confinement has consequences on mental health of detainees. Currently, mental health workers are facing multiple clinical situations such as forced drug and substance withdrawal (linked to difficulties in supplying psychoactive substances), symptoms of anxiety (due to concerns for their own and their relatives' well-being) and decompensation among patients with severe psychiatric conditions. Early releases from prison may also raise some issues. People recently released from prison are identified as at high risk of death by suicide and drug overdose. The lack of time to provide the necessary link between health services within prisons and health structures outside could have serious consequences, emphasizing the well-known "revolving prison doors" effect.

DISCUSSION

The current lockdown measures applied in French jails and prisons point out the disparities between psychiatric care for inmates and psychiatric care for general population. Giving the high vulnerability of prison population, public health authorities should pay more attention to health care in prisons.

Improved efficiency of bulk heterojunction hybrid solar cells by utilizing CdSe quantum dot-graphene nanocomposites

We present a significant efficiency enhancement of hybrid bulk heterojunction solar cells by utilizing CdSe quantum dots attached to reduced graphene oxide (rGO) as the electron accepting phase, blended with the PCPDTBT polymer. The quantum dot attachment to rGO was achieved following a self-assembly approach, recently developed, using thiolated reduced graphene oxide (TrGO) to form a TrGO-CdSe nanocomposite. Therefore, we are able to obtain TrGO-CdSe quantum dot/PCPDTBT bulk-heterojunction hybrid solar cells with power conversion efficiencies of up to 4.2%, compared with up to 3% for CdSe quantum dot/PCPDTBT devices. The improvement is mainly due to an increase of the open-circuit voltage from 0.55 V to 0.72 V. We found evidence for a significant change in the heterojunction donor-acceptor blend nanomorphology, observable by a more vertical alignment of the TrGO-quantum dot nanocomposites in the z-direction and a different nanophase separation in the x-y direction compared to the quantum dot only containing device. Moreover, an improved charge extraction and trap state reduction were observed for TrGO containing hybrid solar cells.

[Plasma cell myeloma in the stomach?]

The detection of a diffuse infiltrate of heterogeneous small B-cells in the lamina propria mucosae invading the epithelium and destroying the glandular tissue by discrete aggregates of three or more marginal zone B-cells above the basal membrane (so-called lymphoepithelial lesions) is suspicious of a mucosa-associated lymphoid tissue (MALT) lymphoma of the stomach. The demonstration of a monoclonal B-cell population by immunohistochemistry, in situ hybridization or PCR excludes a benign lymphatic lesion. In the differential diagnosis with other small B-cell lymphomas in the stomach, a panel of five different immunohistochemical markers is useful to diagnose a small lymphocytic lymphoma (CD5 and CD23 positive), a mantle cell lymphoma (CD5 and cyclin D1 positive) or a follicular lymphoma (BCL2 and CD10 positive). The presence of the translocation t(11;18)(q21;q21) or the API2/MALT1 rearrangement could give further information about the clinical course and the prognosis of a gastric MALT lymphoma.

Functional characterization of an isoform-selective inhibitor of PI3K-p110β as a potential anticancer agent

Genetic approaches have shown that the p110β isoform of class Ia phosphatidylinositol-3-kinase (PI3K) is essential for the growth of PTEN-null tumors. Thus, it is desirable to develop p110β-specific inhibitors for cancer therapy. Using a panel of PI3K isoform-specific cellular assays, we screened a collection of compounds possessing activities against kinases in the PI3K superfamily and identified a potent and selective p110β inhibitor: KIN-193. We show that KIN-193 is efficacious specifically in blocking AKT signaling and tumor growth that are dependent on p110β activation or PTEN loss. Broad profiling across a panel of 422 human tumor cell lines shows that the PTEN mutation status of cancer cells strongly correlates with their response to KIN-193. Together, our data provide the first pharmacologic evidence that PTEN-deficient tumors are dependent on p110β in animals and suggest that KIN-193 can be pursued as a drug to treat tumors that are dependent on p110β while sparing other PI3K isoforms.

SIGNIFICANCE

We report the first functional characterization of a p110β-selective inhibitor, KIN-193, that is efficacious as an antitumor agent in mice. We show that this class of inhibitor holds great promise as a pharmacologic agent that could be used to address the potential therapeutic benefit of treating p110β-dependent PTEN-deficient human tumors.

Tyrosine phosphorylation of Rac1: a role in regulation of cell spreading

Rac1 influences a multiplicity of vital cellular- and tissue-level control functions, making it an important candidate for targeted therapeutics. The activity of the Rho family member Cdc42 has been shown to be modulated by tyrosine phosphorylation at position 64. We therefore investigated consequences of the point mutations Y64F and Y64D in Rac1. Both mutations altered cell spreading from baseline in the settings of wild type, constitutively active, or dominant negative Rac1 expression, and were accompanied by differences in Rac1 targeting to focal adhesions. Rac1-Y64F displayed increased GTP-binding, increased association with βPIX, and reduced binding with RhoGDI as compared with wild type Rac1. Rac1-Y64D had less binding to PAK than Rac1-WT or Rac1-64F. In vitro assays demonstrated that Y64 in Rac1 is a target for FAK and Src. Taken together, these data suggest a mechanism for the regulation of Rac1 activity by non-receptor tyrosine kinases, with consequences for membrane extension.

[Polypoid dysplasia in inflammatory bowel disease: differential diagnosis and further diagnostic and therapeutic approaches]

Polypoid dysplasia in inflammatory bowel disease (IBD) is categorized as DALM (dysplasia associated lesion or mass) or ALM (adenoma-like mass). DALMs are etiologically related to the underlying inflammatory disease, have a high risk of cancer and remain an indication for colectomy. Sporadic adenomas occur coincidentally according to the adenoma-carcinoma sequence. They are adequately treated by polypectomy. More recently, a special group of lesions has been termed as "adenoma-like DALM" which shows a morphological overlap with sporadic adenomas in spite of arising against the background of chronic IBD. Adenoma-like DALMs may possess a lower risk of malignancy in contrast to non-adenoma-like DALMs. They may be treated adequately by polypectomy and continued monitoring if the lesion has been excised completely and there is no evidence of flat dysplasia elsewhere in the colon.

[Endoscopic-bioptic diagnostics, surveillance of and therapy for gastrointestinal diseases according to guidelines]

The present review summarises the detailed recommendations for an optimal endoscopic-bioptic diagnostic procedure, endoscopic surveillance of and therapy for gastrointestinal diseases. The recommendations are mainly based on the S 3-guidelines and have been developed by histopathologists and gastroenterologists in interdisciplinary work. The material has been arranged according to topographic regions of the gastrointestinal tract and clinical problems. The focus is placed on diagnostic and surveillance of Barrett's oesophagus, therapy and postoperative treatment for early gastrointestinal carcinoma, management of colon polyps and endoscopic surveillance of inflammatory bowel disease. Treatment recommendations for both ulcerative colitis and Crohn's disease as well as low-grade and high-grade intraepithelial neoplasia and polypoid neoplasia are currently being intensively discussed. Thus we examine this controversial discussion in detail. Furthermore, the recent guidelines for Helicobacter pylori (H. pylori) and gastric MALT-lymphoma diagnostics are included in this survey. To allow the gastroenterologist a time-sparing overview during practical work, most of the recommendations are presented in itemised form and summarised in tables and figures at the end of the discussion.

[Palmar wrist arthroscopy for evaluation of concomitant carpal lesions in operative treatment of distal intraarticular radius fractures]

Fractures of the distal radius, which currently are treated with palmar locking plates, are often accompanied by carpal lesions. Tears of the scapholunate interosseus ligament (SL) can affect the outcome. Between January 2007 and May 2008, 28 patients with distal intraarticular fractures of the radius were included in a prospective study. Preoperative CT-arthrography was performed. SL tears were found in 11 patients, with 10 partial and one complete rupture observed. A tear of the triangular fibrocartilage complex (TFCC) was detected in 16 patients. Every patient was operated with a palmar locking plate through a palmar approach between the flexor carpi radialis tendon and the radial artery. Then, a palmar wrist arthroscopy using a palmar portal was performed. Eleven SL tears with 9 partial and two total ruptures were diagnosed by arthroscopy. Ten lesions were associated with a C1-fracture with a fracture line projected onto the scapholunate interval. The TFCC was appraisable by palmar wrist arthroscopy only in 4 patients. Three of the SL tears detected by CT-arthrography could not be confirmed by palmar wrist arthroscopy. One complete rupture and one partial lesion confirmed by palmar wrist arthroscopy were found by CT-arthrography to be intact. Palmar wrist arthroscopy affords certainty when assessing the SL ligament. In this study, an assessment of ulnocarpal structures was not possible. For assessment of the ulnocarpal structures, CT-arthrography was superior to palmar wrist arthroscopy. However, the latter is an alternative during emergency treatment or when CT-arthrography is not available.

Triggering receptor expressed on myeloid cells-1 (TREM-1) expression on gastric epithelium: implication for a role of TREM-1 in Helicobacter pylori infection

In Helicobacter pylori gastritis gastric epithelium plays a central role in the innate immunity to H. pylori. However, epithelial receptors interacting with H. pylori have been poorly characterized so far. Recently a new triggering receptor expressed on myeloid cells-1 (TREM-1) has been identified on human neutrophils and monocytes. On these cells TREM-1 triggers innate immunity by stimulating the secretion of interleukin (IL)-8 and tumour necrosis factor (TNF)-alpha and thus amplifies bacterial-induced inflammation. In this study expression and function of TREM-1 in gastric epithelium exposed to H. pylori has been investigated. TREM-1 mRNA and protein were expressed on gastric epithelial cell lines as demonstrated by reverse transcription-polymerase chain reaction (RT-PCR) and fluorescence activated cell sorter analysis. Gastric epithelial TREM-1 expression was up-regulated directly by H. pylori and was independent of epithelial IL-8 induced by H. pylori. Immunohistochemistry and tissue RT-PCR demonstrated significantly stronger TREM-1 expression in H. pylori gastritis compared with the non-inflamed gastric mucosa supporting in vivo that epithelial TREM-1 is up-regulated during H. pylori infection. Stimulation of gastric epithelial TREM-1 receptor resulted in IL-8 up-regulation on mRNA and protein level, as shown by real-time PCR and immunoassay. This is the first study localizing TREM-1 on gastric epithelium. Functional data suggest that TREM-1 expressed on gastric epithelium amplifies inflammation of the underlying gastric mucosa by up-regulation of IL-8.

Gastric extranodal marginal zone B-cell lymphomas of MALT type exclusively express Toll-like receptor 4 in contrast to other lymphomas infiltrating the stomach

BACKGROUND

Development and growth of extranodal marginal zone B-cell lymphomas (eMZBCLs) of mucosa-associated lymphoid tissue (MALT) type are thought to be highly dependent on Helicobacter pylori and autoantigens. Receptors mediating these effects are not characterised so far. Toll-like receptors (TLRs) recognise bacterial proteins and autoantigens, which results in inflammatory reactions and influences tumour development and growth.

MATERIALS AND METHODS

TLR4, 5 and 9 expressions were evaluated by immunohistology and confocal microscopy in gastric eMZBCL in comparison to other lymphomas infiltrating the stomach.

RESULTS

TLR4 was exclusively expressed on the cell surface in all eMZBCL (n = 19) and not in chronic lymphocytic leukaemia (CLL, n = 12) or mantle cell lymphoma (MCL, n = 10). TLR5 was strongly expressed in CLL and weak in some eMZBCL (15 of 19), but not in MCL. TLR4, 5 and 9 were negative in all the three lymphoma entities.

CONCLUSIONS

Exclusive TLR4 expression may enable eMZBCL to interact with H. pylori and autoantigens. Blockade of TLR4 might be a new approach for therapy of eMZBCL of MALT type.

Lymphoepithelioma-like carcinoma of the uterine cervix: absence of Epstein-Barr virus and high-risk human papilloma virus infection

OBJECTIVE

Lymphoepithelioma-like carcinoma (LELC) is a rare variant of squamous cell carcinoma of the uterine cervix. In contrast to Asian women, Caucasian women have a low prevalence of cervical LELC with no infection of the Epstein-Barr virus (EBV) and sporadic appearances of human papilloma viruses (HPV) in Caucasian women.

CASE

We report a 36-year-old female Caucasian patient with LELC of the cervix.

RESULT

In contrast to the present studies, our case of LELC of the cervix is not associated with EBV or high-risk HPV appearances.

CONCLUSION

This is the first study, that showed no relationship between LELC of the uterine cervix with EBV and high-risk HPV infections in a Caucasian woman.

Increased tartrate-resistant acid phosphatase (TRAP) expression in malignant breast, ovarian and melanoma tissue: an investigational study

Background

Tartrate-resistant acid phosphatase (TRAP) is a metalloprotein enzyme that belongs to the acid phosphatases and is known to be expressed by osteoclasts. It has already been investigated as a marker of bone metastases in cancer patients. In this study, which examined the value of serum TRAP concentrations as a marker of bone disease in breast cancer patients, we observed high concentrations of TRAP even in patients without bone metastases. To elucidate this phenomenon, we examined the expression of TRAP in breast cancer cells and the cells of several other malignancies.

Methods

TRAP concentrations in the serum of tumor patients were determined by ELISA. The expression of TRAP in breast, ovarian, and cervical cancer and malignant melanoma was analyzed by immunohistochemistry. RT-PCR and immunocytology were used to evaluate TRAP expression in cultured tumor cells.

Results

A marked increase in serum TRAP concentrations was observed in patients with breast and ovarian cancer, regardless of the presence or absence of bone disease. TRAP expression was found in breast and ovarian cancers and malignant melanoma, while cervical cancer showed only minimal expression of TRAP. Expression of TRAP was absent in benign tissue or was much less marked than in the corresponding malignant tissue. TRAP expression was also demonstrated in cultured primary cancer cells and in commercially available cell lines.

Conclusion

Overexpression of TRAP was detected in the cells of various different tumors. TRAP might be useful as a marker of progression of malignant disease. It could also be a potential target for future cancer therapies.

Epidermal growth factor receptor variant III mutations in lung tumorigenesis and sensitivity to tyrosine kinase inhibitors

The tyrosine kinase inhibitors gefitinib (Iressa) and erlotinib (Tarceva) have shown anti-tumor activity in the treatment of non-small cell lung cancer (NSCLC). Dramatic and durable responses have occurred in NSCLC tumors with mutations in the tyrosine kinase domain of the epidermal growth factor receptor (EGFR). In contrast, these inhibitors have shown limited efficacy in glioblastoma, where a distinct EGFR mutation, the variant III (vIII) in-frame deletion of exons 2-7, is commonly found. In this study, we determined that EGFRvIII mutation was present in 5% (3/56) of analyzed human lung squamous cell carcinoma (SCC) but was not present in human lung adenocarcinoma (0/123). We analyzed the role of the EGFRvIII mutation in lung tumorigenesis and its response to tyrosine kinase inhibition. Tissue-specific expression of EGFRvIII in the murine lung led to the development of NSCLC. Most importantly, these lung tumors depend on EGFRvIII expression for maintenance. Treatment with an irreversible EGFR inhibitor, HKI-272, dramatically reduced the size of these EGFRvIII-driven murine tumors in 1 week. Similarly, Ba/F3 cells transformed with the EGFRvIII mutant were relatively resistant to gefitinib and erlotinib in vitro but proved sensitive to HKI-272. These findings suggest a therapeutic strategy for cancers harboring the EGFRvIII mutation.

The chemokine receptor CCR7 is expressed on epithelium of non-inflamed gastric mucosa, Helicobacter pylori gastritis, gastric carcinoma and its precursor lesions and up-regulated by H. pylori

CCR7 chemokine-receptor expression on tumour cells of gastric carcinoma has been associated with lymph-node metastasis and is thought to play an important role in metastasis. However, so far it is unknown whether CCR7 is newly up-regulated on gastric carcinoma or already expressed in non-neoplastic gastric epithelium. Therefore, epithelial CCR7 expression was investigated in the process of gastric carcinogenesis: non-inflamed mucosa --Helicobacter pylori gastritis -- intestinal metaplasia/dysplasia -- gastric carcinoma. CCR7 was expressed by gastric epithelium in non-inflamed gastric mucosa (n = 5), H. pylori gastritis (n = 17), intestinal metaplasia (n = 10), dysplasia (n = 3) and on tumour cells in 20 of 24 patients with gastric carcinoma (13/14 intestinal-type; 7/10 diffuse-type) as tested by immunohistochemistry. As CCR7 expression by gastric epithelium was significantly stronger in H. pylori gastritis than in non-infected mucosa, the influence of H. pylori on CCR7 receptor expression of gastric epithelial cells was investigated by fluorescence activated cell sorter analysis. H. pylori strains up-regulated the CCR7 chemokine-receptor in CCR7-positive cell lines. No difference in CCR7 up-regulation between cag(+) and cag(-)H. pylori strains was found. Epithelial CCR7 up-regulation by H. pylori may alter the metastatic fate of gastric carcinoma. Additionally, CCR7 expression not only on gastric carcinoma, but also on non-neoplastic gastric epithelium, suggests a novel biological function.

A case of metastasizing invasive hydatidiform mole. Is less--less good? Review of the literature with regard to adequate treatment

BACKGROUND

Patients with invasive hydatidiform moles (IHM) have a good prognosis. Even if disease has spread, monocytostatic treatment might be sufficient if the diagnosis has been histologically confirmed. Established classifications divide gestational trophoblastic disease (GTD) including choriocarcinoma into cases with "high" and "low" risk. Without respect to histology "high-risk" cases are recommended to obtain polychemotherapy.

CASE

A 40-year-old nullipara underwent hysterectomy for persistent vaginal bleeding after she had already been treated with curettage for hydatidiform mole. An IHM was pathohistologically confirmed. There were no signs of pulmonary spread or other metastases at the time of surgery. Postsurgically persistent beta-hCG levels lead to thorough staging, which revealed multiple pulmonary metastases and a vaginal metastasis. Despite metastasizing GTD with poor prognosis criteria she was treated with single agent therapy. Eight cycles of two weekly methotrexate (MTX) were administered. All sites of metastases responded and our patient is still fine after one year of follow-up.

CONCLUSION

With respect to this and other reports monochemotherapy can be a reasonable primary treatment for metastatic IHM.

Expression and subcellular distribution of toll-like receptors TLR4, TLR5 and TLR9 on the gastric epithelium in Helicobacter pylori infection

Toll-like receptors (TLRs) expressed by mucosal epithelium play an essential role in the defense against microbes by recognizing conserved bacterial molecules. For the first time TLR4, TLR5 and TLR9 have been microanatomically localized in patients with noninflamed gastric mucosa and Helicobacter pylori gastritis by immunohistochemistry. Because polarized expression of TLRs in apical and basolateral epithelial compartments is thought to modulate mucosal immunity, subcellular TLR distribution by gastric epithelium was investigated using confocal microscopy. TLR4, TLR5 and TLR9 were expressed by gastric epithelium in antrum and corpus of all patients with H. pylori gastritis (n = 14) and with noninflamed gastric mucosa (n = 5). TLR4 was expressed at the apical and the basolateral pole of the gastric epithelium as well in noninflamed gastric mucosa as in H. pylori gastritis. TLR5 and TLR9 expression in the noninflamed gastric mucosa was identical to that of TLR4 with localization at the apical and the basolateral epithelial pole. However, in H. pylori gastritis TLR5 and TLR9 expression on the gastric epithelium changed to an exclusive basolateral localization without detectable expression at the apical pole. In the human stomach, the gastric epithelium expressed TLR4, TLR5 and TLR9, which gives it the possibility to interact with H. pylori. Furthermore, gastric epithelial TLR4 expression is highly polarized in an apical and a basolateral compartment, whereas TLR5 and TLR9 polarization seems to be a process dynamically influenced by H. pylori infection. This polarized and dynamically regulated gastric epithelial expression of TLRs supports a sentinel role for these receptors in the mucosal immunity to H. pylori.

Finite element and experimental analyses of polymer-based dental bridges reinforced by ceramic bars

Dental bridges made of polymer materials reveal only low loading capacity. This paper analyzes possible improvements of the loading capacity of polymer-based dental bridges reinforced by incorporated ceramic bars. Finite element (FE) analyses were performed to study the stress distribution caused by the mastication process in the bridge material. In the experimental part of the study, the fracture load of dental bridges with and without ceramic bar reinforcement was evaluated. Critical stresses occur in the connector area between abutment and pontic of bridges without bar reinforcement. A suitably shaped ceramic bar incorporated into the polymer-based bridge can significantly reduce these critical stresses. The fracture load of the bridge was increased from 515 to 1603N by the bar reinforcement. We conclude from our study that a ceramic bar can significantly improve the loading capacity of a polymer-based dental bridge. The FE and the experimental analyses revealed that the detailed design of the ceramic bar is of decisive importance for the effectiveness of the suggested ceramic reinforcement.

Pleiotropic effects of CXC chemokines in gastric carcinoma: differences in CXCL8 and CXCL1 expression between diffuse and intestinal types of gastric carcinoma

CXC chemokines modulate host immunity, neovascularization, growth and invasive behaviour of tumours. Despite their relevance in tumour biology, chemokine expression in intestinal- and diffuse-type gastric carcinoma, which exhibit a completely different growth pattern, has not been investigated in detail. In this study, expression of the CXC chemokines CXCL8 [interleukin (IL)-8], CXCL1 [growth-related oncogene alpha (Gro alpha)], CXCL9 [monokine induced by interferon (IFN)-gamma] and CXCL10 [IFN-gamma-inducible protein-10 (IP-10)] and the corresponding chemokine receptors CXCR1-3 was investigated by immunohistochemistry in intestinal- and diffuse-type gastric carcinoma. Tumour cells of all patients expressed CXCL8. CXCL8 expression was significantly stronger in tumour cells of diffuse- rather than intestinal-type gastric carcinoma (P < 0.01) as determined by a semiquantitative score. CXCL1 was expressed almost exclusively by diffuse- but not intestinal-type carcinoma cells. The corresponding chemokine receptors, CXCR1 and CXCR2, were found on carcinoma cells. Furthermore, CXCL8 expression correlated with number of tumour vessels (P < 0.01), suggesting an angiogenetic function in gastric carcinoma not only in vitro but also in vivo. CXCL10 and CXCL9, attractants for T cells, were expressed by peritumorous macrophages in close proximity to IFN-gamma-producing CXCR3-positive T cells in both tumour types. These chemokines may attract gastric carcinoma-infiltrating T cells via an IFN-gamma-mediated pathway and enhance host immunity against the tumour. In gastric carcinoma a complex interplay between CXC-chemokine signals derived from both tumour cells and tumour-infiltrating immune cells may exhibit pleiotropic effects in tumour biology that go far beyond their originally described functions as leucocyte chemoattractants. Because CXCL8 and CXCL1, which are known to increase growth and invasive behaviour of malignant tumours, are significantly stronger expressed in diffuse- than intestinal-type gastric carcinoma, one may speculate that these chemokines influence the different growth pattern of gastric carcinoma types.

[Immunochemical demonstration of human herpes virus 8 in conjunctival Kaposi's sarcoma]

BACKGROUND

Angiomatous lesions of the conjunctiva and chronic conjunctivitis are frequently difficult to differentiate.

CASE

A 28 year old white male sought help because of a conjunctival swelling. A biopsy made elsewhere had revealed a capillary haemangioma of the conjunctiva. Recently striking alterations of the skin led to the suspicion of a Kaposi's sarcoma. Immunohistochemical and dermatological examinations confirmed the diagnosis of a Kaposi's sarcoma and viral testing of serum revealed an HIV-infection. Besides intensive antiviral therapy, our patient underwent local irradiation of the right eye, the nose and of the left shoulder with an external beam.

CONCLUSIONS

Kaposi's sarcoma is the most frequent Aids-associated malignant tumor. In about 30% of all patients with Aids, a Kaposi's sarcoma is diagnosed. The angiomatous character may lead to the histopathological diagnosis of a haemangioma. Human herpes virus 8 is known to be the transforming element.

Hepatic angiomyoma: CT and MRI findings

Angiomyoma is a benign tumor that arises from soft muscular tissue within the blood vessel wall. This lesion has been found in different organs. The preferential location of these tumors is the lower extremity. We describe the rare case of a hepatic angiomyoma and present the radiologic findings of computed tomography and magnetic resonance imaging.

Mapping of epitopes in discoidin domain receptor 1 critical for collagen binding

The binding and activation of the discoidin domain receptor 1 by collagen has led to the conclusion that proteins from the extracellular matrix can directly induce receptor tyrosine kinase-mediated signaling cascades. A region in the extracellular domain of DDR1 homologous to the Dictyostelium discoideum protein discoidin-I is also present in the secreted human protein RS1. Mutations in RS1 cause retinoschisis, a genetic disorder characterized by ablation of the retina. By introducing point mutations into the discoidin domain of DDR1 at positions homologous to the retinoschisis mutations, ligand binding epitopes in the discoidin domain of DDR1 were mapped. Surprisingly, some residues only affected receptor phosphorylation, whereas others influenced both collagen-binding and receptor activation. Furthermore, two truncated DDR1 variants, lacking either the discoidin domain or the stalk region between the discoidin and transmembrane domain, were generated. We showed that (i) the discoidin domain was necessary and sufficient for collagen binding, (ii) only the region between discoidin and transmembrane domain was glycosylated, and (iii) the entire extracellular domain was essential for transmembrane signaling. Using these results, we were able to predict key sites in the collagen-binding epitope of DDR1 and to suggest a potential mechanism of signaling.

A novel proliferation-associated variant of CFR-1 defined by a human monoclonal antibody

The germline coded human monoclonal IgM antibody 103/51 was isolated from a gastric carcinoma patient. This antibody binds to a 130-kd membrane molecule and has a mitotic effect on tumor cells in vitro. To characterize the target, we sequenced the protein and showed that the antibody binds to the cysteine-rich fibroblast growth factor receptor (CFR)-1, which is highly homologous to MG-160 and the E-selectin-ligand (ESL)-1. The epitope was determined by glycosidase-digestion experiments to be an N-linked carbohydrate side chain. Immunohistochemistry was used to investigate the tissue distribution of CFR-1. Different healthy tissues were tested and only the collecting tubes of the kidney, the Golgi apparatus, and the glomerular and fascicular zones of the adrenal gland stained positive. However, on malignant tissue the receptor is overexpressed in nearly all tested stomach cancers (12 of 15) and other tested carcinomas (13 of 15). Most interestingly, the receptor is also present in Helicobacter pylori gastritis and gastric dysplasia, but absent on uninflamed stomach mucosa. This restricted tissue pattern indicates that antibody 103/51 reacts with a membrane-bound variant of CFR-1, which is mainly expressed on transformed cells and precursor lesions and is essential for proliferation processes. The possible activity of antibody 103/51 as an activating ligand in these proliferative changes of gastric epithelial mucosa is discussed.

[Tumor cell embolism to pulmonary arteries]

A 69-year-old male presented with symptoms of fulminant lung embolism and, despite immediate therapy with plasminogen activator, died of acute right heart failure. At autopsy multiple tumor cell emboli were detected in small pulmonary vessels in addition to widespread liver metastases from an urothelial carcinoma. - In a 23-year-old female a malignant gastric ulcer and multiple liver metastases were diagnosed at initial presentation. She too died from pulmonary hypertension due to a series of lung embolisms which occurred despite heparin therapy. At autopsy, many small pulmonary arteries were filled with adenocarcinoma cells; the primary gastric tumor and liver metastases were confirmed. These cases demonstrate that the shedding of tumor cells from hepatic metastases can obstruct the pulmonary vessels and lead to acute cor pulmonale. Tumor cell emboli should be considered in the differential diagnosis of acute pulmonary hypertension, especially in patients with a known tumor. They may, however, also represent the first clinical signs of previously unrecognized malignancy.

CXC chemokines Gro(alpha)/IL-8 and IP-10/MIG in Helicobacter pylori gastritis

Infection with Helicobacter pylori causes chronic active gastritis, which is characterized by neutrophils infiltrating the gastric epithelial layer and the underlying lamina propria as well as by T, B lymphocytes and macrophages accumulating in the lamina propria. In this study, the chemokine profile responsible for the recruitment of these inflammatory cells is investigated. Using both RNA/RNA in situ hybridization and immunohistochemistry, the expression of the neutrophil and/or lymphocyte-attractant CXC chemokines growth-related oncogene alpha (Gro(alpha)), IL-8, interferon-gamma (IFN-gamma)-inducible protein-10 (IP-10), monokine induced by IFN-gamma (MIG) and the CC chemokines macrophage inflammatory protein-1alpha (MIP-1alpha), -1beta, regulated on activation normal T cell expressed and secreted (RANTES) and monocyte chemoattractant protein-1 (MCP-1) is studied and microanatomically localized in the gastric mucosa. Macrophages in the lamina propria at sites with neutrophil infiltration and gastric epithelium infiltrated by neutrophils highly expressed the neutrophil-attractant chemokines Gro(alpha) and IL-8. Additionally, Gro(alpha) and IL-8 were expressed by neutrophils themselves localized within gastric epithelium, in the foveolar lumen and in the cellular debris overlying mucosal erosion. IP-10 and to a lower extent MIG, both selectively chemotactic for inflammatory T cells, were expressed by endothelial cells of gastric mucosal vessels and by mononuclear cells at sites with T cell infiltration. Expression of all other CC chemokines tested was significantly lower. These in vivo data indicate that a set of predominantly CXC chemokines modulates the inflammation in H. pylori gastritis. Gro(alpha) and IL-8 may play an important role in neutrophil trafficking from the mucosal vessel into the gastric epithelium, whereas IP-10 and MIG contribute to the recruitment of inflammatory T cells into the mucosa.

Comparative analysis of the Helicobacter pylori status in patients with gastric MALT-type lymphoma and their respective spouses

Helicobacter pylori is of major importance for the development and progression of gastric MALT-type lymphoma. In case of localized low grade lymphoma successfully treated by Helicobacter pylori eradication reinfection by the bacterium may involve the risk of lymphoma reoccurrence.

AIMS

To assess the frequency and type of Helicobacter pylori infection among patients with gastric MALT-type lymphoma and their respective spouses as potential sources of person to person spread of the infection.

SUBJECTS

35 patients with gastric MALT-type lymphoma and their cohabiting spouses.

METHODS

We investigated serum IgG titers in response to the infection by Helicobacter pylori and to its virulence factors CagA and VacA by enzyme linked immunosorbent assay (ELISA) and by Western blot.

RESULTS

Seropositivity of Helicobacter pylori, Cag A and Vac A was found to be 100/89/69% and 97/86/66% in patients and respective partners, respectively. The seroprevalence rates of the latter group by far exceed those of the German population.

CONCLUSION

These data provide evidence for a high Helicobacter pylori infection rate in both patients with gastric MALT-type lymphoma and their respective spouses. Considering the latter as a potential source of reinfection with the risk of lymphoma reoccurrence for the successfully treated patient with gastric MALT-type lymphoma careful follow-up seems highly reasonable to decide on the necessity of a future test-and-treat strategy of this population.

Helicobacter pylori in gastric mucosa-associated lymphoid tissue type lymphoma

Infection with Helicobacter pylori triggers the acquisition of gastric mucosa-associated lymphoid tissue (MALT) and provides the background for MALT-type lymphoma development. This concept has been supported by a high association of H. pylori infection and MALT-type lymphoma and by the regression of most lymphomas after eradication therapy. In almost all patients with MALT-type lymphoma, serum antibodies to H. pylori were detectable. However, H. pylori was found only in 78% of the patients on histological examination. In addition to other effects, changes in the gastric micro-milieu caused by tumor infiltration of the gastric mucosa may be responsible for the loss of the bacterium. The discrepancy of high seroprevalence and lower histological yield has been already described in other gastric diseases, e.g. atrophic gastritis or gastric carcinoma with extensive destruction of the gastric mucosa. H. pylori strains expressing the CagA protein have been associated with duodenal ulceration and gastric carcinoma. A very high percentage of patients with MALT-type lymphoma is also infected by CagA+ strains of H. pylori as tested by immunoblotting. Antibodies directed to CagA were detectable in the serum as well as in micro-cultured gastric mucosa. Infection with H. pylori may be a precondition for the development of gastric MALT-type lymphoma. In particular, CagA+ strains of H. pylori may, together with additional up to now unknown factors, play a role in the development of gastric MALT-type lymphoma.

Erdheim-Chester disease: evidence for a disease entity different from Langerhans cell histiocytosis? Three cases with detailed radiological and immunohistochemical analysis

Erdheim-Chester (EC) disease is a rare pathological entity with a highly specific and characteristic pattern of radiographic bone changes. Histologically it resembles Langerhans cell histiocytosis (LCH), and it is still a matter of discussion whether EC disease is a distinct entity or a type of LCH. In this study, 3 cases of Erdheim-Chester disease were followed up over years and examined in detail both radiologically and immunohistochemically. All 3 cases showed the pathognomonic skeletal features for EC disease as well as an identical immunohistochemical phenotype quite different from LCH. Macrophages and Touton cells reacted strongly positive with the histiocytic marker CD 68, whereas staining with S100 and CD1a, markers for Langerhans cells, were negative. Both the immunohistochemical phenotype and the bone changes were clearly distinct from LCH.

Identification of immunogenic antigens of Helicobacter pylori via the Escherichia coli hemolysin secretion system(1)

We describe a new procedure allowing the generation and detection of immunogenic antigens from Helicobacter pylori via the hemolysin secretion apparatus of Escherichia coli. The gene (or gene fragment) encoding the H. pylori protein (or protein domain) is inserted in-frame into a residual portion of the hemolysin gene (hlyA), encoding the HlyA secretion signal (HlyA(s)). These fusion proteins are secreted efficiently by E. coli. This new approach allows the identification of immunodominant antigens by using sera derived from H. pylori-infected patients suffering from different gastroduodenal pathologies. Three immunodominant antigens bearing the ureB (urease B-subunit), flaA (flagellin A-subunit), and an unknown ORF (HP0888) encoding an E. coli FecE analogous protein fused to hlyA(s) were identified and characterized.