1/62. Chronic herpes simplex virus type I glossitis in an immunocompromised man.herpes simplex virus (HSV) type 1 (HSV-1) infection of the tongue commonly accompanies acute primary herpetic gingivostomatitis. However, recurrent infection of the tongue is exceptional and is restricted to immunocompromised individuals. A 57-year-old man with corticosteroid-dependent chronic obstructive pulmonary disease and sciatica presented with a chronic median glossitis due to HSV-1. The main clinical and histological feature was massive necrosis of the entire mucosa. immunohistochemistry demonstrated a considerable amount of HSV gB, gC and gD envelope glycoproteins dispersed in the chorion. In contrast, HSV-1 dna was detected only in a limited number of epithelial cells using in situ hybridization. The extent of necrosis and the pattern of viral dna and envelope protein distribution represent unique features of median herpetic glossitis, which are not found in more common types of HSV infection.- - - - - - - - - - ranking = 1keywords = hybridization (Clic here for more details about this article) |
2/62. Extramedullary relapse despite graft-versus-leukemia effect after bone marrow transplantation in a girl with juvenile myelomonocytic leukemia.A 12 year-old girl with juvenile myelomonocytic leukemia (JMML) and monosomy 7 underwent allogeneic bone marrow transplantation (BMT) from her HLA-matched brother. To monitor the engraftment and the course of the disease we used fluorescence in situ hybridization (FISH) with probes specific for the centromeres of chromosomes X, Y and 7. Complete hematological remission was achieved and confirmed by the virtually exclusive presence of normal male cells in the bone marrow (BM). Acute graft-versus host disease (GvHD) was treated with prednisone and cyclosporine A (CSA) and female cells with monosomy 7 reoccurred in the peripheral blood (PB) and BM. After discontinuation of the immunosuppressive therapy, the leukemic cells with monosomy 7 disappeared again from these compartments. One year after transplantation, isolated extramedullary relapses occurred in lymph nodes and skin, followed by dissemination of blast cells into the BM, whereas the PB cells remained of donor origin. The fact that the leukemic cells fluctuated with the intensity of the immunosuppressive treatment provides evidence of a graft versus leukemia (GvL) effect in this unusually old girl with JMML with a unique extramedullary disease progression.- - - - - - - - - - ranking = 1keywords = hybridization (Clic here for more details about this article) |
3/62. Recurrent bacteremia caused by a "Flexispira"-like organism in a patient with X-linked (Bruton's) agammaglobulinemia.Helicobacter spp., except for Helicobacter cinaedi, have only rarely been reported in cases of septicemia. A patient with X-linked (Bruton's) agammaglobulinemia was found to have persistent sepsis with a Helicobacter-like organism despite multiple courses of antibiotics. His periods of sepsis were associated with leg swelling thought to be consistent with cellulitis. The organism was fastidious and required a microaerophilic environment containing H(2) for growth. Optimal growth was observed at 35 to 37 degrees C on sheep blood, CDC anaerobe, and Bordet-Gengou agars. Serial subcultures every 4 to 5 days were required to maintain viability. The organism was strongly urease positive and showed highest relatedness to Helicobacter-like organisms with the vernacular name "Flexispira rappini" by 16S rRNA gene sequence analysis. Genomic dna hybridization studies, however, found 24 to 37% relatedness to "F. rappini" and even less to other Helicobacter spp. Although the organism phenotypically resembles "Flexispira" and Helicobacter, it is thought to represent a new taxon. The patient's infection was eventually cleared with a prolonged (5-month) course of intravenous imipenem and gentamicin.- - - - - - - - - - ranking = 1keywords = hybridization (Clic here for more details about this article) |
4/62. A case of recurrent congenital fetal anomalies associated with a familial subtelomeric translocation.The potential of a new fluorescent in situ hybridization technique is discussed, which uses a complete set of telomeric probes to reveal cryptic chromosome rearrangements that remain undetected by standard cytogenetic analysis. We report the obstetric history of a patient who had a termination of pregnancy at 20 weeks for a fetus with multiple congenital anomalies but a normal male karyotype using conventional G-banding analysis on a mid-trimester placental biopsy. In a subsequent pregnancy, a diaphragmatic hernia and intra-uterine growth restriction were detected at 34 weeks' gestation and a fetal blood sample showed a normal female karotype. However, her child was born with dysmorphic features and additional severe abnormalities including microcephaly, anophthalmos and left fixed talipes. The child has shown marked developmental delay. In view of a strong family history of congenital abnormalities and recurrent miscarriage suggestive of a familial translocation, a fluorescent in situ hybridization technique using specific telomeric probes was performed on blood from the affected child and her parents. An unbalanced subtelomeric translocation was detected involving the long arms of chromosomes 2 and 7 in the child and a balanced translocation was detected in her father. Accurate genetic counselling and the opportunity for early prenatal diagnosis can now be offered to this family.- - - - - - - - - - ranking = 2keywords = hybridization (Clic here for more details about this article) |
5/62. association of lamivudine resistance in recurrent hepatitis B after liver transplantation with advanced hepatic fibrosis.BACKGROUND: Orthotopic liver transplantation (OLT) in patients with hepatitis b virus (HBV) infection is known to be associated with a high recurrence rate and poor prognosis. lamivudine, a nucleoside analogue, is a potent inhibitor of HBV replication, but it is associated with a 14-39% rate of resistance. methods: We report on four patients who underwent OLT for HBV infection. In all cases, the HBV infection recurred in the grafted liver and was treated with lamivudine (100 mg daily) on a compassionate-use basis. The patients were monitored closely for serum liver enzymes, hepatitis B surface antigen and HBV dna (by hybridization). Liver biopsy was performed before and after lamivudine therapy. HBV dna was amplified from serum for each patient and sequenced through a conserved polymerase domain, the tyrosine-methionine-aspartate-aspartate (YMDD) locus. RESULTS: All four patients exhibited lamivudine resistance 9-20 months after initiation of the drug. In all patients with a clinically mild disease, liver histology findings (12-24 months after lamivudine therapy) showed progressive fibrosis as compared to biopsies performed before lamivudine therapy, with a significant increase (> or =2 points) in the Knodell score in three patients. Moreover, two patients exhibited worsening of the necroinflammatory process. A mutation at the YMDD motif of the HBV polymerase gene was detected in all cases. CONCLUSIONS: lamivudine resistance frequently occurs in patients with recurrent HBV infection after OLT and is associated with advanced hepatic fibrosis and necroinflammatory process. A combination of antiviral therapies may be necessary.- - - - - - - - - - ranking = 1keywords = hybridization (Clic here for more details about this article) |
6/62. Epstein-Barr virus-associated lymphoproliferative skin lesion with recurrent necrotic papulovesicles of the face.A 24-year-old man showed recurrent necrotic papulovesicles of the face. The cutaneous lesions started with erythema, followed by vesicles, necrosis, and crusting, and leaving depressed scars. light avoidance did not prevent the development of the lesions. Histologic examination revealed lymphoproliferative lesions confined to the skin. Latent Epstein-Barr virus (EBV) infection was detected in the lymphoid cells from the skin lesions by in situ hybridization. A moderate to high dosage of corticosteroids suppressed the development of new skin lesions, but relapses occurred when these systemic corticosteroids were tapered.- - - - - - - - - - ranking = 1keywords = hybridization (Clic here for more details about this article) |
7/62. Loss of the TEL/ETV6 gene by a second translocation in ALL patients with t(12;21).Inactivation of the non translocated TEL/ETV6 gene is commonly associated with translocation (12;21) of acute lymphoblastic leukemia (ALL). Translocations involving the short arm of chromosome 12 were analysed in two children with t(12;21) ALL. fluorescence in situ hybridation studies showed that these associated translocations resulted in loss of TEL/ETV6. While hybridization with a YAC probe covering TEL/ETV6 was positive in one patient, analysis with cosmid probes covering the gene demonstrated that the gene was in fact deleted. It is concluded that deletions involving TEL/ETV6 can remain undetected by FISH using only YAC probes.- - - - - - - - - - ranking = 1keywords = hybridization (Clic here for more details about this article) |
8/62. Mucosa-associated lymphoid tissue-type lymphomas occurring in post-transplantation patients.Post-transplantation lymphoproliferative disorders (PTLDs) are usually Epstein-Barr virus (EBV)-associated B-cell lymphoproliferative disorders that vary in their morphologic spectrum. Extranodal marginal zone lymphomas of the mucosa-associated lymphoid tissue-type (MALT-type) have not been considered to be part of this spectrum. The authors encountered five such cases recently. The clinical, histopathologic, and immunophenotypic features are reported. There were three men and two women with a mean age of 51.2 years (range, 48-63 years). Two patients were cardiac transplant recipients, two patients were liver transplant recipients, and the remaining patient was a renal transplant patient. Sites of lymphoma were the stomach in three patients and the parotid gland in two patients. Mean time to the lymphoma was 84 months after transplantation. All patients had morphologic features of low-grade extranodal marginal zone lymphomas of the MALT-type, and helicobacter pylori was present in all three gastric cases. All patients exhibited the B-cell immunophenotype and were negative for EBV by in situ hybridization. These lymphomas were treated with a variety of modalities, including reduction of immunosuppression, antibiotics, surgical resection, radiation therapy, and chemotherapy. At last follow-up, one patient had developed signet ring adenocarcinoma at 27 months but had no evidence of PTLD, one patient relapsed at 17 months but is alive with stable disease at 24 months, and the remaining patients were alive without disease at 11, 12, and 14 months. Extranodal low-grade MALT-type lymphomas can occur in the post-transplantation setting and generally develop years after transplant. As seen in immunocompetent patients, EBV appears to play no role in the pathogenesis of these lymphomas. These lymphomas appear to have more in common with MALT-type lymphomas in nonimmunocompromised patients than conventional PTLDs, although they occur in "at-risk" patients due to their immunosuppressive therapy. These lymphomas do not appear to be clinically aggressive. Recognition of MALT-type lymphomas in the post-transplantation setting as an indolent disease avoids unnecessary treatment.- - - - - - - - - - ranking = 1keywords = hybridization (Clic here for more details about this article) |
9/62. A novel t(11;12)(q23-24;q24) in a case of minimally-differentiated acute myeloid leukemia (AML-M0).Acute myeloid leukemia with minimal signs of myeloid differentiation (AML-M0) is a recent addition to the FAB group classification. Chromosome data is scarce, but existing reports describe a high incidence of complex karyotypes and myelodysplastic syndrome-like chromosome alterations, while single chromosome translocations have rarely been reported. We describe the case of a 60-year-old woman diagnosed with AML-M0 with a novel translocation t(11;12)(q23-24;q24) as the sole karyotypic marker. fluorescence in situ hybridization analysis to assess MLL gene splitting did not show rearrangement of this oncogene.- - - - - - - - - - ranking = 1keywords = hybridization (Clic here for more details about this article) |
10/62. Histopathology and vascular endothelial growth factor in untreated and diode laser-treated retinopathy of prematurity.OBJECTIVES: We had the unique opportunity to compare the eyes of a premature infant with stage 3 retinopathy of prematurity (ROP) in both eyes after the condition was treated by diode laser photocoagulation in one eye only. After the infant's death, we investigated the extent of structural damage incurred with the diode laser and examined the effect of treatment on vascular endothelial growth factor (VEGF) expression. methods: The eyes were fixed and embedded in paraffin. Adjacent 6 microns sections were either stained for histopathologic analysis or used for in situ hybridization. VEGF messenger rna (mRNA) was detected by using radiolabeled antisense riboprobes. RESULTS: In the treated eye, histopathologic results demonstrated the clinically evident dose-response effect, with sparing of inner retinal elements with mild laser burns and full-thickness retinal cell disruption with severe burns. Scleral and ciliary nerve effects were absent. VEGF mRNA was localized primarily in the ganglion cell layer but was also found in the inner nuclear layer. In the untreated eye, an increase in VEGF mRNA was detected at the peripheral edge of the vascularized retina anterior to the ridge. In the laser-treated eye, VEGF mRNA expression was dramatically upregulated in the ganglion cell layer in areas adjacent to laser burns. CONCLUSIONS: VEGF mRNA was found to be elevated in the peripheral, avascular retina of the untreated eye, consistent with the hypothesis that retinal hypoxia stimulates VEGF expression. In the treated eye with recurrent ROP, VEGF mRNA was not detected in the photocoagulated areas of retina but was increased between laser scars. This finding confirms the results of prior animal studies and validates the use of these models.- - - - - - - - - - ranking = 1keywords = hybridization (Clic here for more details about this article) |
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