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Biomedical subjects

B Borisch

Publications and source records attributed to B Borisch.

At least 37 records · Page 2Linked to original sources
PubMed2000

Divergent expression of cyclin-dependent kinase inhibitors (CKI) and p14ARF/p16 beta in non-Hodgkin's lymphomas and chronic lymphocytic leukemia.

Chronic B-cell lymphocytic leukaemia (CLL) and low-grade B-cell Non Hodgkin's lymphomas (Lg-NHL) are characterized by slow accumulation of neoplastic cells arrested in the G0/G1 phase of the cell cycle. In contrast, proliferation rates are high in aggressive B-cell lymphomas (Hg-NHL). Divergent expression of cyclin-dependent kinase inhibitors (CKI) in the cell cycle may contribute to these differences. We analysed CLL as well as low and high grade B-cell NHL for expression of G1-specific and universal CKI by competitive RT-PCR and immunostaining. p16(INK4A) expression was low in all types of neoplasms. Highest p14(ARF) /p16 beta expression levels were found in normal lymphocytes. Expression of this CKI was significantly lower in CLL, but still higher in CLL than in the lymphomas (median 27 vs. 3 mRNA transcripts x 10(3), p = 0.0001). p14(ARF) /p16 beta immunostaining correlated with mRNA expression. Highest p21 mRNA levels were found in CLL, but three of four CLL with abundant p21 mRNA production were negative on immunostaining. High grade lymphomas showed markedly decreased p21 expression (3.9 in Hg-NHL vs. 12 in Lg-NHL and 29 in CLL; values expressed as mRNA transcripts x 10(3), p < 0.009). mRNA and protein expression of p27 was considerably higher in CLL than in the lymphomas. Differential CKI expression in various B-cell neoplasias may provide important biological markers, if not the molecular underpinning of their different cell cycle kinetics. Targeted interference with such genes governing cell cycle control in lymphoid neoplasia may pave the way towards new treatment strategies.

Adult↗
PubMed2000

Epstein-Barr virus association in pediatric abdominal non-Hodgkin-lymphomas from Turkey.

Recent studies have shown marked geographic variation associated with Epstein-Barr virus (EBV) in pediatric Burkitt's lymphomas and Hodgkin's disease. In the present study we investigated 30 cases of pediatric extranodal high grade non-Hodgkin's lymphomas (NHL) from Turkey with an abdominal localisation. To classify them histologically and to determine the role of EBV in these lymphomas, immunohistochemistry (IHC), in situ hybridisation (ISH) and polymerase chain reaction (PCR) were used. Our series contained two histologic types: the Burkitt's or Burkitt's-like lymphomas (BL/BLL) and high grade NHL. They all were of the B cell type. The immunoglobulin heavy chain gene rearrangement revealed monoclonality in 87% of the BL/BLL cases, in contrast to the NHL cases, showing monoclonality in only 43% of the cases. EBV was found in tumor cells in a high frequency, independent of the histological subtype. EBV strains A and B were detected in 9 cases, with a preponderance of the B subtype (4/9 BL/BLL; 4/9 NHL). Our data suggest that high grade NHLs with abdominal localisation of Turkish children show the pattern of immunodeficient lymphomas to some extent.

Abdominal Neoplasms↗
PubMed1999

Traumatic neuroma with biliary duct obstruction after orthotopic liver transplantation.

BACKGROUND: Traumatic neuromas may develop after injury to nerve fibers encased in Schwann cells. The incidence of symptomatic neural tumors appears to be low after orthotopic liver transplantation (OLT). Only two cases of biliary stricture caused by infiltrating traumatic neuroma have been described previously. METHODS: We report two new cases of biliary tract obstruction after OLT that failed to respond to percutaneous balloon dilatation and were corrected by a resection of the bile duct stricture followed by biliary reconstruction with a Roux-en-Y jejunal loop. RESULTS: The first patient (17 months after OLT) had a traumatic neuroma appearing as a distinct mass with nerve bundles confirmed histologically; the traumatic neuroma in the second patient (5 months after OLT) was a nerve stump with infiltration of nervous elements in the bile duct. Both patients recovered without complications. CONCLUSIONS: Traumatic neuromas should be considered in the differential diagnosis of late biliary stricture after OLT, in particular when not responding to percutaneous dilatation or stenting.

Anastomosis, Roux-en-Y↗
PubMed1999

Aberrant FHIT mRNA transcripts are present in malignant and normal haematopoiesis, but absence of FHIT protein is restricted to leukaemia.

Aberrant FHIT mRNA transcripts are present in malignant and normal haematopoiesis, but absence of FHIT protein is restricted to leukaemia Alterations of the recently cloned fragile histidine triad (FHIT) gene at chromosome 3p14.2 are frequent in a variety of solid tumours and cancer cell lines. Based on these findings, FHIT has been proposed as a putative tumour-suppressor gene. We evaluated the mRNA expression of the FHIT gene in samples from 55 patients with various haematological malignancies (21 AML, 8 CML, 10 CLL, seven low-grade and nine high-grade Non-Hodgkin's lymphomas), in a panel of 16 leukaemia cell lines, in normal mature haematopoietic cells of both myeloid and lymphoid lineage, as well as in CD34+ haematopoietic progenitor cells. Aberrant FHIT mRNA transcripts were observed in 14/16 (88%) leukaemia cell lines, 43/55 (78%) primary haematological neoplasms, but also in 17/22 (77%) normal controls. 1/16 (6%) cell lines and 7/55 (13%) neoplasms did not express any FHIT mRNA. cDNA sequencing revealed exonic deletions, small DNA insertions and combinations of both. Analysis of genomic DNA showed gene deletions in two myeloid leukaemia cell lines. In contrast to all normal types of haematopoietic cells, FHIT protein was clearly reduced or absent in 8/18 (44%) neoplastic samples tested. Our data indicate that whilst aberrant FHIT mRNA transcripts are seen both in normal and malignant cells, lack of FHIT protein is restricted to leukaemia. Absent FHIT protein expression might contribute to leukaemogenesis.

Acid Anhydride Hydrolases↗
PubMed1999

Clinical behavior of solitary fibrous tumors of the pleura.

BACKGROUND: Solitary fibrous tumors of the pleura are rare and present unpredictable clinical behavior. METHODS: Between 1981 and 1998, 11 solitary fibrous tumors of the pleura were resected in 10 patients at the University Hospital of Geneva. Their clinical behavior and outcome were reviewed. RESULTS: Seven tumors arose from the visceral pleura, and three arose from the parietal pleura. Tumors arising from the parietal pleura were revealed to be more difficult to resect than those from the visceral pleura because of their size and adhesion to the chest wall requiring extrapleural resection. Eight tumors showed benign features, whereas two showed distinct features of malignity. One additional patient presented marked pleomorphism that could represent an intermediate form before frank malignity. Four tumors had been followed expectantly for 2 to 10 years before surgery. Although three enlarged rapidly, no signs of malignity were observed on histological examination. All patients are alive, from 2 months to 14 years after surgery (mean 55 months). In one case, however, a malignant tumor recurred 6 years after resection of a benign variant. CONCLUSIONS: Although histologically benign, solitary fibrous tumors of the pleura may enlarge rapidly and occasionally transform into malignant variants after several years. Therefore, complete surgical resection and long-term follow-up is recommended for all patients.

Adult↗
PubMed1999

Signal transduction via CD44: role of plasma membrane microdomains.

CD44 is the principal cell surface receptor for extracellular matrix glycosaminoglycan hyaluronan. CD44-hyaluronan mediated cell adhesion is important in several pathophysiological processes such as inflammation and metastatic spread of cancer cells. It has been recently recognized that CD44 also functions as a signaling receptor in a variety of cell types. Cell stimulation by monoclonal anti-CD44 antibody or natural CD44 ligands activate several signaling pathways that culminate in cell proliferation, cytokine secretion, chemokine gene expression and cytolytic effector functions. One of the earliest signaling events following stimulation via CD44 is tyrosine phosphorylation of intracellular proteins substrates, and CD44 mediated cellular activation could be abolished by protein tyrosine kinase (PTK) inhibitors. The Src-family non-receptor PTKs such as Lck, Fyn, Lyn and Hck were shown to be coupled to CD44 via sphingolipid-rich microdomains (lipid rafts) of the plasma membrane. Studies on T cell receptor and IgE receptor mediated signaling in lymphocytes and mast cells have consolidated the notion that microdomains consist of signaling platforms where components of multiple signaling pathways are assembled. Co-isolation of CD44 with microdomains strongly suggests that CD44 generates cellular activation signals utilizing the signaling machinery of the plasma membrane microdomains.

Animals↗
PubMed1999

Microdomain-dependent regulation of Lck and Fyn protein-tyrosine kinases in T lymphocyte plasma membranes.

Src family protein-tyrosine kinases are implicated in signaling via glycosylphosphatidylinositol (GPI)-anchored receptors. Both kinds of molecules reside in opposite leaflets of the same sphingolipid-enriched microdomains in the lymphocyte plasma membrane without making direct contact. Under detergent-free conditions, we isolated a GPI-enriched plasma membrane fraction, also containing transmembrane proteins, selectively associated with sphingolipid microdomains. Nonionic detergents released the transmembrane proteins, yielding core sphingolipid microdomains, limited amounts of which could also be obtained by detergent-free subcellular fractionation. Protein-tyrosine kinase activity in membranes containing both GPI-anchored and transmembrane proteins was much lower than in core sphingolipid microdomains but was strongly reactivated by nonionic detergents. The inhibitory mechanism acting on Lck and Fyn kinases in these membranes was independent of the protein-tyrosine phosphatase CD45 and was characterized as a mixed, noncompetitive one. We propose that in lymphocyte plasma membranes, Lck and Fyn kinases exhibit optimal activity when juxtaposed to the GPI- and sphingolipid-enriched core microdomains but encounter inhibitory conditions in surrounding membrane areas that are rich in glycerophospholipids and contain additional transmembrane proteins.

Animals↗
PubMed1999

Primary hepatic diffuse large B-cell lymphoma in a patient with chronic hepatitis C.

Epidemiological and experimental data suggest that the hepatitis C virus infection might be associated with the development of distinct types of non-Hodgkin's lymphomas. Here, we report a case of a patient with chronic hepatitis C and type II mixed cryoglobulinemia, who developed a primary hepatic non-Hodgkin's B-cell lymphoma. A diffuse, large B-cell lymphoma was diagnosed based on morphological, immunophenotypical and molecular genetic findings. Hepatitis C virus replication, as evaluated by strand-specific reverse transcriptase-polymerase chain reaction, was detected in the nonneoplastic liver, but not in the lymphomatous tissue. High grade non-Hodgkin's lymphomas, although rare complications, have to be considered as part of the spectrum of hepatitis C virus-related hepatic lesions.

Cryoglobulinemia↗
PubMed1999

Detection of mycobacterial nucleic acids by polymerase chain reaction in fixed tissue specimens of patients with human immunodeficiency virus infection. Swiss HIV Cohort Study.

A polymerase chain reaction (PCR) method, which amplifies a fragment of the 16S ribosomal RNA (rRNA) gene present in all mycobacterial species, was developed and tested on 84 formalin-fixed paraffin-embedded tissue specimens from 51 patients with human immunodeficiency (HIV) infection. The PCR products were characterized either by sequencing or by hybridization with nonradioactive oligonucleotide probes specific for Mycobacterium tuberculosis complex, M. avium, or M. genavense. Sequencing was successful for 26 samples compared with the 45 samples for probe hybridization. The sensitivity of DNA amplification compared with microscopic examination was 79.5%. A mixed infection was detected with M. genavense for only one patient who was infected with M. tuberculosis complex. In the group of 22 control patients, where no diagnosis of mycobacterial infection was made during life and no acid-fast bacteria were seen during the autopsy, four samples of one patient were positive by hybridization with the M. tuberculosis probe. This patient had a clinical history compatible with tuberculosis. This PCR method may be a powerful tool for the precise diagnosis of mycobacterial infections from histopathologic material, provided that several sections from the same specimen block are tested.

AIDS-Related Opportunistic Infections↗
PubMed1999

[Pathology].

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Diagnostic Techniques and Procedures↗
PubMed1998

Relation of smoking to breast cancer by estrogen receptor status.

It has been suggested that smoking is associated with estrogen-negative breast cancer but not with estrogen-positive breast cancer. A population-based case-control study was conducted in Geneva, Switzerland, to determine the relation of passive and active smoking to breast cancer when the referent unexposed category consisted of women unexposed to active and passive smoke. The 242 patients with breast cancer (cases), in whom estrogen receptor (ER) status was determined on biopsy material, were compared with 1,059 women free of breast cancer (controls). Lifetime history of active and passive smoking was recorded year by year, between age 10 and the date of interview. Prevalence rates of ER+ tumors were 74.7% in pre-menopausal women and 74.2% in post-menopausal women. Post-menopausal active smokers had a lower prevalence of ER+ tumors (70.0%, p = ns). Among pre-menopausal women, the age-adjusted ORs of breast cancer with having smoked an average of > or = 20 cigarettes per day (cpd) during lifetime were 2.7 for ER- tumors and 2.6 for ER+ tumors. Among post-menopausal women, corresponding ORs were 5.7 for ER- tumors and 2.4 for ER+ tumors. Smoking was related to both ER- and ER+ breast cancer in pre- and post-menopausal women, but the strength of the association appeared to be greater for ER- tumors among post-menopausal women.

Aged↗
PubMed1998

Management of true aneurysms of the splenic artery.

BACKGROUND: Splenic artery aneurysms (SAA) are detected with increasing frequency but their management still remains controversial. This paper relates our experience in the outcome and management of ruptured aneurysms of the splenic artery. METHODS: Between 1977 and 1996, 8 patients presented to our institution with a ruptured SAA. Their ages ranged from 25 to 72 years (mean 55 ys). RESULTS: All patients presented with rupture as the first sign of SAA. One patient was at 32 weeks of gestation and rupture suggested placental abruption. Three patients required cardiopulmonary reanimation prior to surgical procedures. Splenopancreatectomy (n = 4), splenectomy (n = 2), and ligation of the splenic artery (n = 1) were performed. Seven of the 8 patients survived. Size of aneurysms ranged from 2 cm to 3.5 cm (mean 3 cm). CONCLUSIONS: SAA may rupture at any age. Diagnosis during pregnancy rests upon a high index of suspicion. The mortality rate remains low if immediate resuscitation is performed and an aggressive surgical approach is taken.

Adult↗