Biomedical subjects

S Dirnhofer

Publications and source records attributed to S Dirnhofer.

At least 37 records · Page 2Linked to original sources

PubMed2003

Immunohistochemical typing of non-small cell lung cancer on cryostat sections: correlation with clinical parameters and prognosis.

AIMS: To investigate the immunohistochemical expression of a panel of biologically relevant markers in patients with non-small cell lung cancer using fresh frozen specimens and to test their prognostic relevance for identification of patients at risk. METHODS: Seventy nine tumour infiltrated lung cancer specimens and 66 adjacent histologically tumour free tissues were analysed; 11 postmortem specimens from patients who did not suffer from a malignant disease served as a control group. Cryostat sections were stained with monoclonal antibodies against epidermal growth factor receptor (EGFR), c-erbB-2, c-erbB-3, CD82, Ki-67, p120, p53, bcl-2, and CD31. RESULTS: At least one of the tested markers was raised above the defined cut off point in 75 of the tumours. In 55, three to six factors were increased. EGFR was raised in 32, c-erbB-2 in 29, c-erbB-3 in 46, p53 in 29, bcl-2 in 26, Ki-67 in 36, p120 in 46, and CD31 in 29. None of the tested parameters was significant in univariate survival analysis. In a second step, three variables were combined (c-erbB3, p53, and microvessel density), and cases with increased expression of two or three parameters proved to have a significantly lower survival probability than those expressing none or only one factor. In the tumour free group only 10 showed raised marker expression. CONCLUSION: Characterisation of tumour cells in surgical specimens with immunohistological markers could help identify those patients at risk for early cancer death who could possibly profit from adjuvant treatment after curative tumour resection.

Antigens, CD↗

PubMed2003

Prognostic significance of CD44 expression in diffuse large B cell lymphoma of activated and germinal centre B cell-like types: a tissue microarray analysis of 90 cases.

BACKGROUND: Gene expression profiling of diffuse large B cell lymphoma (DLBCL) revealed three disease types: germinal centre B cell-like (GC), activated B cell-like (ABC), and a "third" type. Expression of CD44 variant isoforms (CD44v) is associated with an unfavourable clinical outcome in DLBCL, but previous studies did not consider the clinicopathological heterogeneity of this disease. AIMS: To analyse the expression and prognostic significance of CD44 in DLBCL types. METHODS: A tissue microarray (TMA) comprising 90 DLBCLs was constructed. CD10, CD20, bcl-2, bcl-6, CD44 standard isoform (CD44s), and CD44v4, CD44v6, and CD44v9 were analysed immunohistochemically and correlated with clinical follow up. RESULTS: TMA expression of CD10, CD20, bcl-2, and bcl-6 showed 100% concordance with results from conventional sections in 60 cases. Samples were segregated into 22 GC (bcl-6+/CD10+/bcl-2-), 25 ABC (bcl-6-/CD10-/bcl-2+), and 35 unclassifiable DLBCLs. Overall survival (OS) at 30 months was 89%, 44%, and 58% in GC, ABC, and unclassified types, respectively. CD44v6 was coexpressed with bcl-2, appeared predominantly on bcl-6 negative cases, and correlated with disease stage. Cases negative for CD44s could be separated into CD44v6 negative (OS, 82% at 70 months) and CD44v6 positive (OS, 58%). CONCLUSIONS: TMA technology is useful for immunophenotyping and clinicopathological analysis of large lymphoma populations. The GC phenotype of DLBCL is of independent prognostic significance for OS. Expression of CD44v6 correlates with disease stage, and might contribute to lymphoma dissemination. CD44v6 is expressed predominantly in ABC DLBCL, and in CD44 negative cases is associated with worse OS.

Biomarkers, Tumor↗

PubMed2002

[Differentiated papillary kidney tumors. Differentiation between metanephric adenoma and papillary adenoma].

Metanephric adenoma of the kidney is a well described tumor entity. The differential diagnosis between papillary adenoma or papillary carcinoma type 1 and metanephric adenoma of the kidney can be challenging in single cases. We report two cases of metanephric adenomas and compare their immunophenotype with a papillary adenoma. The analysis of these metanephric adenomas and a review of the literature shows that CD-57 positivity and lack of EMA expression are helpful in distinguishing metanephric adenoma from papillary adenoma and papillary carcinoma. Glomeruloid structures, Psammoma bodies, necrosis or expression of cytokeratin 7 and vimentin are common features in metanephric adenoma and papillary adenoma or papillary carcinoma. The knowledge of the immunohistochemical constellation is important, because metanephric adenoma can be very large and often have some necrosis.

Adenoma↗

PubMed2002

Diffuse large B-cell lymphoma: one or more entities? Present controversies and possible tools for its subclassification.

Diffuse large B-cell lymphoma (DLBCL) is the commonest type of lymphoid tumour world-wide. This category was included both in the REAL and WHO Classification aiming to lump together all malignant lymphomas characterized by the large size of the neoplastic cells, B-cell derivation, aggressive clinical presentation, and the need for highly effective chemotherapy regimens. These tumours are detected as primary or secondary forms both at the nodal and extranodal levels, in immunocompetent hosts as well as in patients with different types of immunosuppression. They display a significant variability in terms of cell morphology and clinical findings, which justifies the identification of variants and subtypes. Among the latter, the primary mediastinal one does actually correspond to a distinct clinicopathological entity. Immunophenotypic, tissue microarray and molecular studies underline the extreme heterogeneity of DLBCLs and suggest a subclassification of the tumour, based on the identification of different pathogenic pathways, which might have much greater relevance than pure morphology for precise prognostic previsions and adoption of ad hoc therapies. The more recent acquisitions on the pathobiology of DLBCLs are reviewed in the light of the authors' experience, aiming to contribute to the existing debate on the topic.

Animals↗

PubMed2002

Diffuse large B-cell lymphoma with infiltration-associated peripheral neuropathy and paraneoplastic myopathy with a prolonged course over seven years.

Rarely lymphoproliferative disorders (LPD) may be associated with peripheral neuropathy, based on different mechanisms of pathogenesis. Here, we report a case of a primary extranodal diffuse large B-cell lymphoma which showed a prolonged course with several recurrences manifesting as neuropathies, and long term remissions achieved by chemotherapy and involved field radiation. Repeated pathohistologic evaluations showed spread of lymphoma growth predominantly along nerve structures, suggesting neurotropism of the lymphoma cells.

Humans↗

PubMed2002

Intravascular large B-cell lymphoma with a fulminant clinical course: a case report with definite diagnosis post mortem.

A patient is described who presented with pancytopenia, splenomegaly and excessively elevated lactate dehydrogenase levels in concurrence with signs of extramedullary hematopoiesis. Although initially considered in the differential diagnostic spectrum, a highly aggressive lymphoma could not be identified before the patient died, 6 weeks after admission. Even an intensive diagnostic work-up including splenectomy and repeated bone marrow biopsies was inconclusive. Finally, the diagnosis of an intravascular large B-cell lymphoma, a highly aggressive clinical subtype of a diffuse large B-cell lymphoma, spreading within vascular structures of multiple organs was established by autopsy. Intravascular large B-cell lymphoma is often not diagnosed before death due to the exclusive intravascular growth pattern of the tumor cells and a fulminant clinical course. The heterogeneous clinical features of this lymphoma subtype are discussed.

Autopsy↗

PubMed2001

Heat shock protein expression in the transplanted human kidney.

Heat shock proteins (HSPs) have been shown to represent potential target molecules for T-cell-mediated allograft rejection in heart and kidney transplants. In the present study, we therefore investigated the expression of HSP subtypes 60, 72, and 73 in normal kidneys and qualitative and/or quantitative changes in rejected renal allografts. Six normal kidney tissue specimens, three biopsies from patients with minimal change nephritis, as well as 37 biopsies and eight transplant nephrectomy specimens of patients with renal allograft rejection were studied. Type and severity of rejection were assessed according to the Banff classification. Immunohistochemical demonstration of HSP expression was performed using specific monoclonal antibodies after wet autoclave antigen retrieval on sections from either Carnoy-fixed (biopsies) or formalin-fixed (transplant nephrectomies) and paraffin-embedded tissue. The expression was scored in a semiquantitative manner. All three subtypes were found to be constitutively expressed in normal kidney tissue and in noninflammatory minimal change nephritis, albeit with a characteristic compartmental and cellular distribution. Rejection resulted in a higher immunohistochemical scoring for all three HSP subtypes in compartments in which they were normally present; in addition, a de novo expression of HSP60 was found in the vascular compartment and, moreover, infiltrating mononuclear cells were strongly immunoreactive for HSP60 and HSP73. Only quantitative differences were observed for HSP72 immunoreactivity. These results indicate that rejection episodes are paralleled by an increased but differential expression of HSPs in the glomerular, tubular, and vascular compartments of the kidney. This enhancement as well as the de novo appearance of HSP60 on vascular endothelial cells might explain the presence of HSP-reactive T lymphocytes in rejected allografts.

Carrier Proteins↗

PubMed2001

Hypoxia induces heat shock protein expression in human coronary artery bypass grafts.

OBJECTIVE: Heat shock proteins (HSPs) are molecular chaperones which are essential for cell survival. Heat shock and hypoxia markedly increase the expression of several HSPs in various tissues, i.e. heart. In our in vitro study, we investigated whether HSPs are inducible in human vessels which are used as coronary artery bypass grafts. METHODS: We used remnants of the saphenous vein and the internal mammary artery from 34 patients undergoing coronary artery bypass surgery. Each vessel was divided into segments, one for control conditions at 37 degrees C (5% CO(2)-95% air), the remaining ones for thermal (30 min at 42 degrees C) or hypoxic treatment (6 h oxygen deprivation with nitrogen). The expression of Hsp60, Hsp72 and Hsp73 was investigated by immunohistochemistry and Western-blot analysis. RESULTS: Compared to controls, segments of the saphenous vein undergoing heat treatment showed significantly increased expression of Hsp72 in the intima (P=0.035) and Hsp73 in the media (P=0.003). In the internal mammary artery, Hsp72 and Hsp73 were expressed in the intima at significantly higher levels (P=0.042 each). A 6 h oxygen deprivation with nitrogen resulted in elevated levels of Hsp60 (media: P=0.048), of Hsp72 (intima: P<0.001 and media: P=0.004) and of Hsp73 (intima: P=0.029) in the saphenous vein. In the internal mammary artery, Hsp73 expression was significantly enhanced (intima: P=0.048 and media: P=0.017). The results were confirmed by Western-blot analysis in representative veins. CONCLUSIONS: These findings demonstrate the common cellular defense mechanism of HSP expression in response to stress in coronary artery bypass grafts. Hypoxia and heat treatment strongly induce Hsp72 and Hsp73 expression in human coronary artery bypass grafts.

Aged↗

PubMed2001

p27(Kip1) immunostaining for the differential diagnosis of small b-cell neoplasms in trephine bone marrow biopsies.

The distinction between mantle cell lymphoma (MCL) and other small B-cell non-Hodgkin lymphomas (NHL) is important because MCL has a more aggressive clinical course. In bone marrow (BM) biopsy specimens, this distinction can be particularly difficult. Although cyclin D1 immunostaining and molecular detection of the t(11;14) translocation are highly specific markers for MCL, they fail to detect a proportion of cases. We have recently described that MCL typically lacks detectable expression of the cyclin-dependent kinase inhibitor p27(kip1) protein by immunostaining, which is expressed at high levels in most small B-cell NHL inversely correlated to the proliferation rate. We therefore examined whether p27(kip1) immunostaining could be a useful adjunct for the differential diagnosis of small B-cell NHL infiltrates in the BM. Trephine BM biopsy specimens of 96 patients, including well-characterized MCL (19 cases), B-cell chronic lymphocytic leukemia (27 cases), follicular lymphoma (18 cases), hairy cell leukemia (22 cases), and marginal zone lymphoma (10 cases) as well as 10 reactive BM, including five with benign lymphoid aggregates were investigated. In addition, the presence of a t(11;14) translocation involving the major translocation cluster was studied by PCR in all MCL. All cases of B-cell chronic lymphocytic leukemia, follicular lymphoma, and marginal zone lymphoma revealed a strong p27(kip1) nuclear staining in the majority of neoplastic cells. Fourteen (78%) cases of MCL were p27(kip1)-negative in the tumor cells, whereas four cases revealed a weak nuclear positivity. Seventeen (77%) cases of hairy cell leukemia were also either completely negative for p27(kip1) or showed a faint positive staining in a minority of the neoplastic cells. Nine of 19 cases (47%) of MCL showed a bcl1 rearrangement involving the major translocation cluster region. These findings demonstrate that p27(kip1) immunostaining is a valuable additional marker for the differential diagnosis of small B-cell NHL infiltrates in BM biopsies. The reduction or lack of p27(kip1) protein expression in MCL, as well as in hairy cell leukemia, might be an important event in the pathogenesis of these disorders.

Biopsy↗

PubMed2001

Epstein-Barr virus-associated extranodal NK/T-cell lymphoma, nasal type of the hypopharynx, in a renal allograft recipient: case report and review of literature.

Posttransplant lymphoproliferative disorders (PTLPDs) are predominantly B-cell lymphoproliferations, whereas a T-cell origin is rarely observed. In contrast to B-cell PTLPD, T-cell PTLPDs show an inconsistent association with Epstein-Barr virus (EBV). Until now, only 13 cases of EBV-associated T-cell PTLPDs have been reported. We describe a case of an EBV-associated T-cell PTLPD in a renal allograft recipient 2 years after transplantation. Histologic examination showed medium- to large-sized lymphoid cells with an angiocentric growth pattern and necrosis. The atypical cells showed a CD2+, CD3epsilon+, CD7+, CD43+, CD45R0+, CD56+, and CD4-, CD5-, CD8- betaF1- phenotype with expression of the latent membrane protein (LMP)-1 of EBV. In addition, EBV-specific RNAs (EBER 1/2) were identified by in situ hybridization. Molecular analysis of the T-cell receptor (TCR) gamma chain by polymerase chain reaction (PCR) showed a polyclonal pattern. The morphologic, immunohistochemical, and molecular findings were consistent with a diagnosis of an EBV-associated extranodal natural killer (NK)/T-cell non-Hodgkin lymphoma (NHL) of nasal type. To our knowledge, this is the first reported case of this rare entity in the posttransplant setting.

Aged↗

PubMed2001

Primary gastrointestinal B-cell lymphoma. A clincopathological and immunohistochemical study of 61 cases with an evaluation of prognostic parameters.

We hereby present a retrospective clinicopathological and immunohistochemical study of surgically resected primary gastrointestinal (GI) lymphoma with an analysis of parameters of potential prognostic relevance. From a larger series of 144 cases of primary GI lymphomas, we chose 61 cases with sufficient clinical follow-up (mean 60, range 1-219 months), classified either as extranodal marginal zone B-cell lymphoma of MALT type (MALT lymphoma) or diffuse large B-cell lymphoma (DLBCL), after having excluded other subtypes. In addition to conventional clinical and morphological parameters, the expression levels of Ki-67 (MIB-1), bcl-2 and p53 were evaluated for prognostic significance. Twenty-one (34.4%) cases were classified as pure low grade marginal zone B-cell lymphoma of MALT type, 12 (19.7%) cases as low grade MALT lymphoma with a high grade component (mixed type), and 28 (45.9%) cases as primary extranodal DLBCL. Most of the lymphomas (53/61; 86.9%) were localized in the stomach, 3 (4.9%) in the small bowel, 3 (4.9%) multifocal in both stomach and small intestine and 2 (3.3%) in the large bowel. MIB-1 expression in more than 30% of tumor cells was detected in 42 (68.6%), bcl-2 expression in 20 (32.8%) and p53 accumulation in more than 10% of neoplastic cells in 16 (26.2%) lymphomas. Both high Ki-67 expression and p53 accumulation were more prevalent in the DLBCL. 30 (49%) patients showed lymph node involvement at surgery, 14 (23%) patients suffered tumor recurrence, and 24 (38.5%) died during the follow-up period. Tumor recurrence occurred primarily in patients who had presented lymph node involvement (9/14, 64.3%). The 5-year survival rate was 66.1% for all patients. Important prognostic factors for overall survival were tumor stage (p < .004) and p53 accumulation (p < .05) in univariate analysis, and tumor stage in multivariate analysis (p < .001). Although p53 accumulation did not reach statistical significance in our small study group, it may be both important in the transformation of low grade MALT lymphoma and an indicator for aggressive behavior in high grade tumors.

Adult↗

PubMed2000

Evidence from a leukaemia model for maintenance of vascular endothelium by bone-marrow-derived endothelial cells.

BACKGROUND: Vascular endothelial cells lost from the blood-vessel endothelium through necrosis or apoptosis must be replaced. We investigated in a leukaemia model whether bone-marrow-derived endothelial cells contribute to this maintenance angiogenesis. METHODS: We studied six patients with chronic myelogenous leukaemia (CML) carrying the BCR/ABL fusion gene in their bone-marrow-derived cells. We screened endothelial cells generated in vitro from bone-marrow-derived progenitor cells and vascular endothelium in myocardial tissue for the BCR/ABL fusion gene by in-situ hybridisation. For detection of donor-type endothelial cells after transplantation of haemopoietic stem cells, recipient tissue was stained with monoclonal antibodies against donor-type HLA antigens. FINDINGS: We identified the BCR/ABL fusion gene in variable proportions (0-56%) of endothelial cells generated in vitro. Endothelial cells expressing the fusion gene were found in the vascular endothelium of a patient. In a recipient of an allogeneic stem-cell transplant, normal donor-type endothelial cells were detected in the vascular endothelium. INTERPRETATION: These findings suggest that CML is not solely a haematological disease but originates from a bone-marrow-derived haemangioblastic precursor cell that can give rise to both blood cells and endothelial cells. Moreover, normal bone-marrow-derived endothelial cells can contribute to the maintenance of the blood vascular endothelium. The integration of bone-marrow-derived endothelial cells into the vascular endothelium provides a rationale for developing vascular targeting strategies in vasculopathies, inflammatory diseases, and cancer.

Adult↗

PubMed2000

Transplantation of IL-2-transduced murine bone marrow is associated with dose-dependent toxicity.

OBJECTIVE: The purpose of this study was to investigate the effects of interleukin-2 (IL-2) gene-transduced hematopoietic progenitor cells or cytotoxic function and systemic toxicity following syngeneic bone marrow transplantation. MATERIAL AND METHODS: Marrow of 5-fluorouracil pretreated donor mice were transfected with a retroviral vector containing the murine IL-2 gene and transplanted into lethally irradiated syngeneic hosts. RESULTS: Productive insertion of the IL-2 gene could be demonstrated at various intervals post-transplant without impairment of hematopoietic engraftment. Endogenously augmented IL-2 release resulted in a selective increase in CD4(+), CD8(+), and NK1.1(+) population in spleen and bone marrow, as well as significant cytolytic activity against syngeneic leukemia cells in vitro. Our results also illustrate the interdependence among the magnitude of systemic IL-2 levels, the number of IL-2-transduced cells in the transplant inoculum, and the appearance of systemic toxicity. Infusion of marrow transduced with high-titer, high-expressing IL-2 retrovirus resulted in significant morbidity and mortality in the recipients. Our studies demonstrate that mortality was secondary to severe lymphocytic infiltration of liver and lung, which was associated with increased expression of intercellular adhesion molecule-1 and vascular adhesion molecule-1. Reducing the number of IL-2-transduced cells in the bone marrow inoculum, however, resulted in significantly improved survival with no adverse events being evident during the post-transplant period. CONCLUSION: Delivery of IL-2 to the bone marrow can be achieved by transplantation of genetically modified hematopoietic cells, however, the overall feasibility is strongly influenced by the number of transduced cells in the bone marrow inocolum and/or the expression pattern of IL-2 in vivo.

Animals↗

PubMed2000

Selective expression of trophoblastic hormones by lung carcinoma: neurendocrine tumors exclusively produce human chorionic gonadotropin alpha-subunit (hCGalpha).

Recent findings suggest that glycoprotein- and protein hormones act as local auto/paracrine growth/differentiation factors in normal and malignant tissue. An imbalanced or even selective production of human chorionic gonadotropin-alpha (hCGalpha) by neuroendocrine tumors in various organs has been reported. In this context, the ectopic production of trophoblastic hormones by lung carcinoma has not been investigated systemically. Because the determination of serum levels of hCGalpha are flawed by a number of factors, we designed an immunohistochemical study to precisely assess the comprehensive paraneoplastic auto-/paracrine hormone production by lung carcinoma of various histological types. To this end, 90 patients with primary lung neoplasms (40 neuroendocrine tumors, 29 adenocarcinomas, 20 squamous cell carcinomas, and 1 adenosquamous carcinoma) were analyzed by our well characterized monoclonal antibodies (mabs) against the glycoprotein hormones hCG, and its derivatives hCGalpha, hCGbeta, hCGbeta core-fragment (hCGbetacf), luteinizing hormone (LH, LHbeta), follicle-stimulating hormone (FSH, FSHbeta), and the protein hormones placental lactogen (PL) and growth hormone (GH). Overall, trophoblastic hormone immunoreactivity was found in 31% (28/90) of all lung carcinomas, regardless of histological differentiation. Detailed analysis showed 23% (21/90) hCGalpha-, 7% (6/90) hCGbeta, and 2% (2/90) hCGbetacf-positive cases. The tumors produced neither the intact heterodimer hCG, nor the other placental protein hormones PL-A/B and GH-V, or the hCG-related pituitary gonadotropins FSH/FSHbeta and LH/LHbeta. With regard to histological differentiation, it appeared that neuroendocrine tumors exclusively produced free hCGalpha in a distinct expression pattern depending on histological tumor grade. Thirty-eight percent (15/40) of all neuroendocrine neoplasms were hCGalpha-positive, and marker positivity increased with more mature, highly differentiated tumors (20% of small cell neuroendocrine carcinomas versus 90% of atypical and typical carcinoids). This is in striking contrast not only to trophoblastic malignancies and testicular germ cell tumors, but also to nontrophoblastic tumors, such as gynecological and urothelial malignancies, 60% of which produce hCGbeta and where marker positivity correlates with poor histological tumor differentiation. In conclusion, free hCGalpha, but not hCGbeta, is a useful marker for neuroendocrine differentiation in primary lung tumors. The fact that it is preferentially produced by the differentiated tumor types (carcinoids) points to a putative biological function in these tissues. The few hCGbeta-positive NSCLC must not be confounded with primary mediastinal choriocarcinoma.

Adult↗

PubMed2000

Epstein-Barr virus-associated multicentric leiomyosarcoma in an adult patient after heart transplantation: case report and review of the literature.

Epstein-Barr virus (EBV)-associated smooth muscle tumors following solid organ transplantation are extremely rare, with only 12 cases reported in the literature thus far. The exact pathogenetic role of EBV infection in the oncogenesis of these soft tissue tumors in immunodeficient patients and the biologic behavior of such tumors is still unclear. We report a 26-year-old man in whom multiple smooth muscle tumors developed 36 to 51 months after heart transplantation. All tumors, two synchronous liver nodules, two subsequently occurring paravertebral tumors, and a single tumor in a vein at the left ankle were surgically resected. The tumor tissue was processed for routine histology and immunohistochemical (IHC) stains. Additionally, competitive polymerase-chain-reaction (PCR), reverse-transcriptase PCR (RT-PCR), as well as in situ hybridization (ISH) were used for EBV particle quantification and gene transcription analysis. The histologic features and immunohistochemical profiles were consistent with leiomyosarcoma in all tumor nodules. EBV infection was detected in >95% of tumor cell nuclei by EBER 1/2 ISH. Competitive PCR revealed 3105 EBV particles per milligram of tumor tissue. The EBV gene expression pattern analyzed by RT-PCR and IHC corresponded to the latency type III with specific expression of EBNA1, EBNA2, LMP1, and LMP2A genes. Under continuous antiviral therapy (famcyclovir) the patient currently shows no evidence of disease. Our data indicate that EBV infection plays a causal role in the development of smooth muscle tumors following organ transplantation. A latency type III, identical to EBV-associated posttransplant lymphoproliferative disorders, was identified and suggests a common pathogenetic mechanism in the development of these histogenetically distinct neoplasms. The fact that the patient currently shows no evidence of disease may be the result of the continuous administration of antiviral therapy because the soft tissue recurrences of the leiomyosarcoma occurred while the patient was not receiving antiviral prophylaxis.

Adult↗

PubMed2000

Mouse model of transplant arteriosclerosis: role of intercellular adhesion molecule-1.

Transplant-accelerated arteriosclerosis in coronary arteries is the major limitation to long-term survival of patients with heart transplantation. The pathogenesis of this disease is not fully understood. Herein, we describe a simplified model of artery allografts in the mouse that allows us to take advantage of transgenic, knockout, or mutant animals. Common carotid arteries or aortic vessels were end-to-end allografted into carotid arteries between C57BL/6J and BALB/c mice. Neointimal lesions were observed as early as 2 weeks after surgery and had progressed at 4 and 6 weeks postoperatively. The lumen of grafted arteries was significantly narrowed due to neointima hyperplasia 4 weeks after transplantation. Using this model, we studied the role of intercellular adhesion molecule-1 (ICAM-1) in the development of transplant arteriosclerosis in ICAM-1-deficient mice. Neointimal lesions of artery grafts from ICAM-1 -/- C57BL/6J to BALB/c mice were reduced up to 60% compared with wild-type controls. MAC-1 (CD11b/18)-positive cells adhering to the surface of ICAM-1 -/- artery grafts were significantly less as identified by en face immunofluorescence, and these positive cells were more abundant in intimal lesions of artery grafts in wild-type mice. Furthermore, the major cell component of neointimal lesions 4 weeks after surgery was found to be alpha-actin-positive smooth muscle cells, which were significantly reduced in lesions of ICAM-1 -/- artery grafts. Thus, this model has been proven to be useful for understanding the mechanism of transplant arteriosclerosis. Our findings demonstrate that ICAM-1 is critical in the development of allograft arteriosclerosis via mediation of leukocyte adhesion to, and infiltration into, the vessel wall.

Actins↗

PubMed1999

The testis-specific expression pattern of the growth hormone/placental lactogen (GH/PL) gene cluster changes with malignancy.

Growth hormone (GH) and placental lactogen (PL) gene transcription patterns in testicular germ cell tumors (GCT) and normal testicular tissue were comparatively investigated to identify GH/PL gene products associated with the development of GCT. This was done by nondiscriminative reverse transcriptase-polymerase chain reaction (RT-PCR), amplifying all major transcripts of any of the 5 GH/PL genes--GH-N(ormal), GH-V(ariant), PL-A, PL-B, PL-L(ike)--and subsequent analytical restriction enzyme analyses of 5'-end radioactively labeled cDNA. Surprisingly, all nonseminomatous GCT (NSGCT; n = 9) expressed GH-N, PL-A/B, and PL-L transcripts (9 of 9). Seminoma (n = 7) showed a distinctly unique pattern of GH-N and PL-A/B. GH-V products, which are hallmarks of the normal healthy testis, were not detected in any testicular cancer specimen (0 of 16). The fact that both seminomatous and NSGCT showed alterations in the same gene cluster indicates a pathogenetic relationship. Two choriocarcinoma cell lines of conceptus origin, BeWo and JAR, clearly differing from the male counterparts, exhibited a placental-derived pattern of PL-A/B and GH-V. Obviously, profound differences exist between conceptus and male germ cell GH/PL gene cluster transcription. In summary, the unique testicular pattern of GH/PL gene expression changes significantly and in directed ways with malignancy. Loss of GH-V gene expression in testicular GCT compared with normal testis and loss (seminoma) or mutation (NSGCT) of PLL gene products might have significance in terms of the relationship between these tumors and for testicular GCT development.

Adult↗

PubMed1999

High prevalence of a 30-base pair deletion in the Epstein-Barr virus (EBV) latent membrane protein 1 gene and of strain type B EBV in Mexican classical Hodgkin's disease and reactive lymphoid tissue.

Depending on geographic location and patient age Hodgkin's disease (HD) is associated with Epstein-Barr virus (EBV), mostly type A EBV, in 20% to 100%. The highest prevalence occurs in children of developing countries. Molecular analysis of the oncogene coding for the latent membrane protein 1 (LMP-1) revealed a 30-base pair (bp) deletion in up to 46% of EBV-positive HD. We investigated the presence of EBV in a series of Mexican classical HD (n = 57) and reactive lymphoid tissues (n = 20) from a private and a public hospital with special emphasis on the prevalence of the 30-bp deletion and the type of EBV. EBV infection was analyzed at the cellular level by Epstein-Barr encoded early RNA transcripts (EBER) in situ hybridization (ISH) and by LMP-1 protein immunohistochemistry (IHC). Molecular analysis of the LMP-1 gene configuration was performed by polymerase chain reaction (PCR) with primers spanning the site of the deletion and subsequent Southern and/or dot blot hybridization using wild-type and deletion-specific probes. The prevalence of type A and type B EBV was investigated by PCR-analysis for divergence in the coding region of Epstein-Barr nuclear antigen (EBNA)-2. EBV was detected in Hodgkin- and Reed-Sternberg cells (H-RS) by LMP-1 IHC and/or EBER ISH in 35/57 (61%) Mexican HD including 18/32 (56%) with nodular sclerosis, 15/20 (75%) with mixed cellularity and 2/4 (50%) with lymphocyte depletion. In addition, LMP-1 gene sequences were detected by PCR in 9 cases of HD without LMP/EBER expression by H-RS cells and in 17/20 (85%) reactive lymph nodes, supposedly originating from rare latently infected B cells. Surprisingly, the 30-bp LMP-1 deletion was found in 28/35 (80%) EBV-positive HD. This deletion, however, was also found in all 9 (100%) HD with H-RS cells negative for EBV and in 10/17 (59%) reactive lymph nodes. Thus, the overall LMP-1 del prevalence in reactive tissue is 73% (19/26). Typing of EBV was successful in 26 cases of EBV-positive HD, 10 of these were infected by type B EBV (38%). Of the reactive lymphoid tissue, 9 (47%) were infected by type A, and 10 (53%) by type B; All 20 cases (100%) associated with type B, whether neoplastic or reactive, displayed the LMP-1 del variant compared with 18/25 (72%) infected by type A EBV. To our knowledge, this is the highest incidence for both the LMP-1 deletion variant and the infection by type B EBV in HD reported so far worldwide. Our data suggest that EBV infection contributes to the pathogenesis of the majority of Hodgkin's disease cases in Mexico. The specific tumorigenic role of the LMP-1 deletion variant, however, is doubtful with regard to its high frequency in nonneoplastic lesions. Moreover, type B infection frequently occurs in Mexican HD and reactive lymphoid tissue and is consistently associated with the deletion variant pointing to a pathogenetic role of this combined genotype.

Adolescent↗