Mosaicism for trisomy 21: a review

The clinical and cytogenetic findings associated with mosaicism for trisomy 21/Down syndrome are the focus of this review. The primary topics discussed in this overview of the extant literature include the history of this condition and its diagnosis, the incidence of mosaicism, the meiotic and/or mitotic chromosomal malsegregation events resulting in mosaicism, the observation of mosaicism in the parents of children with the non-mosaic form of Down syndrome, and the variation in phenotypic outcome for both constitutional and acquired traits present in people with mosaicism for trisomy 21/Down syndrome, including cognition, fertility, and overall phenotypic findings. Additional topics reviewed include the social conditions of people with mosaicism, as well as age-related and epigenetic alterations observed in people with mosaicism for trisomy 21/Down syndrome. .

T-cell prolymphocytic leukemia in a 63-year-old female with a pre-existing T-cell large granular lymphocytic leukemia: metachronous T-cell leukemias with discordant subset restrictions (CD4 versus CD8) and distinct clonal identities

A 55-year-old female with T-cell large granular lymphocytic leukemia (T-LGL) (CD8+) was initially treated with anti-thymocyte globulin and then cyclosporine due to anemia/neutropenia. While the severity of cytopenia varied with the therapy, the T-LGL persisted. Eight years after the initial diagnosis, she developed lymphadenopathy and hepatosplenomegaly. A complete blood cell count revealed leukocytosis, anemia and thrombocytopenia with ∼ 80% lymphocytes. In contrast to the LGL cells, the blood lymphocytes at this time were medium-large in size and had oval/irregular nuclei, condensed chromatin, indistinct nucleoli and a moderate amount of basophilic cytoplasm, many with elongated vacuoles, and some with cytoplasmic projections. The abnormal lymphocytes comprised ∼ 30% of the bone marrow cellularity with interstitial infiltrates/aggregates. Immunophenotypic analyses demonstrated a T-cell neoplasm with features suggestive of T-cell prolymphocytic leukemia (T-PLL) (CD4+). Cytogenetic analysis revealed a novel clone with complex abnormalities. PCR-based TRG gene rearrangement studies detected a clonal amplicon distinct from that of the preexisting T-LGL. Because of the chronological sequence of the two T-cell neoplasms, this case was initially considered an aggressive transformation of T-LGL. However, this was ultimately excluded by a discordant CD4-subset restriction and the presence of a distinct clonal identity. While these two T-cell neoplasms may have intrinsic connections, the underlying pathogenesis remains to be investigated.

Dishevelled-3 activates p65 to upregulate p120-catenin transcription via a p38-dependent pathway in non-small cell lung cancer

Dishevelled-3 (Dvl-3) and p120-catenin (p120ctn) have abnormal expression in non-small cell lung cancer (NSCLC), which is associated with poor prognosis. Dvl-3 upregulates p120ctn transcription in NSCLC cells, but the mechanism is unknown. Here we transiently transfected Dvl-3 cDNA to NSCLC cells. Dvl-3 transfection is sufficient for induction of p38 signaling. In turn, Dvl-3 induces p38-mediated activation of the p65 so as to facilitate its nuclear translocation. Treatment with SB203580 (p38 inhibitor) or BAY 11-7082 (IκB-α phosphorylation inhibitor) suppresses Dvl-3 induced activation of p65. The results further show that active p65 interacts with PAX2 promoter to increase the expression of PAX2 and then PAX2 binds to p120ctn promoter so as to upregulate p120ctn gene transcription. Moreover, Dvl-3 transfection enhanced the binding of active p65 to Sp1 so as to decrease the binding of Sp1 to p120ctn promoter. The above-mentioned effects are linked to biological behavior of non-small cell lung cancer cells. These findings confirm that p38 and PAX2 are important for the Dvl-3 induced upregulation of p120ctn. Dvl-3 activates a p38 → p65 → PAX2 → p120ctn pathway to affect biological behavior of NSCLC cells.

An Epstein-Barr virus-positive diffuse large B-cell lymphoma presenting as multi-organ failure: a catastrophic lymphomatosis with fulminant visceral organ dissemination resulting in a precipitous death in a 59-year-old female with no identifiable etiology for immunodeficiency

Epstein-Barr virus (EBV)-positive diffuse large B-cell lymphoma (EBV+ DLBCL) of the elderly is an aggressive B-cell neoplasm related to age-associated impaired immunity. We report such a case in a 59-year-old woman with a catastrophic disease course. The patient initially presented with fever, fatigue, malaise and weakness over one-week period. Despite empirical treatment with antibiotics and antiviral agents, she subsequently developed multi-organ failure and coagulopathy. Radiographic imaging revealed hepatomegaly, splenomegaly, pleural effusion, and ascites. Her complete blood cell count showed marked leukocytosis, anemia and thrombocytopenia. Morphologic examination of blood smear demonstrated many abnormal plasmacytoid lymphocytes, and flow cytometric analysis detected an intermediate-large mature B-cell population (69%) without detectable surface immunoglobulin. High copy numbers of EBV genome were detected in the blood by PCR. A diagnosis of EBV+ DLBCL, leukemic phase, was made. Despite aggressive treatment and supportive care, the patient succumbed to multi-organ failure one week after initial presentation. Autopsy demonstrated EBV+ DLBCL infiltration in all the organs examined. This case describes an unusual presentation of EBV+ DLBCL and highlights the necessity of pertinent ancillary tests to avoid delay in the diagnosis and treatment.

Ataxia-telangiectasia group D complementing gene (ATDC) promotes lung cancer cell proliferation by activating NF-κB pathway

Previous studies suggested Ataxia-telangiectasia group D complementing gene (ATDC) as an oncogene in many types of cancer. However, its expression and biological functions in non-small cell lung cancer (NSCLC) remain unclear. Herein, we investigated its expression pattern in 109 cases of human NSCLC samples by immunohistochemistry and found that ATDC was overexpressed in 62 of 109 NSCLC samples (56.88%). ATDC overexpression correlated with histological type (p<0.0001), tumor status (p = 0.0227) and histological differentiation (p = 0.0002). Next, we overexpressed ATDC in normal human bronchial epithelial cell line HBE and depleted its expression in NSCLC cell lines A549 and H1299. MTT and colony formation assay showed that ATDC overexpression promoted cell proliferation while its depletion inhibited cell growth. Furthermore, cell cycle analysis showed that ATDC overexpression decreased the percentage of cells in G1 phase and increased the percentage of cells in S phase, while ATDC siRNA treatment increased the G1 phase percentage and decreased the S phase percentage. Further study revealed that ATDC overexpression could up-regulate cyclin D1 and c-Myc expression in HBE cells while its depletion down-regulated cyclin D1 and c-Myc expression in A549 and H1299 cells. In addition, ATDC overexpression was also associated with an increased proliferation index, cyclin D1 and c-Myc expression in human NSCLC samples. Further experiments demonstrated that ATDC up-regulated cyclin D1 and c-Myc expression independent of wnt/β-catenin or p53 signaling pathway. Interestingly, ATDC overexpression increased NF-κB reporter luciferase activity and p-IκB protein level. Correspondingly, NF-κB inhibitor blocked the effect of ATDC on up-regulation of cyclin D1 and c-Myc. In conclusion, we demonstrated that ATDC could promote lung cancer proliferation through NF-κB induced up-regulation of cyclin D1 and c-Myc.

Handoffs in the era of duty hours reform: a focused review and strategy to address changes in the Accreditation Council for Graduate Medical Education Common Program Requirements

With changes in the Accreditation Council for Graduate Medical Education (ACGME) Common Program Requirements related to transitions in care effective July 1, 2011, sponsoring institutions and training programs must develop a common structure for transitions in care as well as comprehensive curricula to teach and evaluate patient handoffs. In response to these changes, within the Duke University Health System, the resident-led Graduate Medical Education Patient Safety and Quality Council performed a focused review of the handoffs literature and developed a plan for comprehensive handoff education and evaluation for residents and fellows at Duke. The authors present the results of their focused review, concentrating on the three areas of new ACGME expectations--structure, education, and evaluation--and describe how their findings informed the broader initiative to comprehensively address transitions in care managed by residents and fellows. The process of developing both institution-level and program-level initiatives is reviewed, including the development of an interdisciplinary minimal data set for handoff core content, training and education programs, and an evaluation strategy. The authors believe the final plan fully addresses both Duke's internal goals and the revised ACGME Common Program Requirements and may serve as a model for other institutions to comprehensively address transitions in care and to incorporate resident and fellow leadership into a broad, health-system-level quality improvement initiative.

Resected pancreatic neuroendocrine tumors: Patterns of failure and disease-related outcomes with or without radiotherapy

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Background: Pancreatic neuroendocrine tumors (NET) are rare with improved prognosis compared to adenocarcinomas. Surgical resection remains the standard of care although many patients present with unresectable/metastatic disease. While many resected patients will fail distantly, little is known regarding the use of adjuvant radiotherapy. To define this and establish specific patterns of failure, an analysis of resected patients from a single institution was performed.

Methods: From 1994 to 2009, 33 patients with NET of the pancreatic head underwent resection with curative intent at Duke University. Sixteen patients were treated with surgical resection alone, and an additional 17 underwent resection with adjuvant (n=10) or neoadjuvant (n=7) radiation therapy, usually with concurrent fluoropyrimidine-based chemotherapy (CMT). Median radiation dose was 50.4 Gy and median follow-up 28 months.

Results: Patients receiving radiation therapy were more likely to have involved nodes (47% vs 19%, p=0.09), more mitoses per high power field (p=0.10) and involved margins (47% vs 31%, p=0.20) compared to surgery alone patients. Median survival for the whole cohort was 52 months. Two-year survival was 68% for the CMT group and 93% for the surgery alone group (p=0.03). Two-year local control was 85% for the CMT and 90% for the surgery group (p=0.49). Two-year metastasis-free survival was 45% and 69% for the CMT and surgery patients, respectively (p=0.02).

Conclusions: Patients receiving CMT were more likely to have adverse pathologic features compared to surgery-alone patients. Survival outcomes were high in both groups, although less so in the CMT group. Distant metastasis development dominated patterns of failure. Local failure following resection of NETs is uncommon, and the role of adjuvant radiotherapy in this setting remains unclear.

No significant financial relationships to disclose.

The phenotype of persons having mosaicism for trisomy 21/Down syndrome reflects the percentage of trisomic cells present in different tissues

Little is known about the pathogenesis of the phenotype in individuals with trisomy 21 mosaicism and Down syndrome. The primary goal of this study was to identify factors contributing to the observed phenotypic variation by evaluating 107 individuals having trisomy 21 mosaicism. To investigate a potential "threshold" effect due to trisomic imbalance, lymphocyte and buccal mucosa nuclei were scored using FISH. Overall, buccal cells showed a significantly higher frequency of trisomy than lymphocytes (P < 0.0001). Using latent class analysis, two phenotypic classes were identified based on the clinical findings of the propositi. Patients from class 1 had significantly fewer traits and a lower percentage of trisomic cells (mean of 37.3% lymphocytes; 34.5% buccal mucosa cells) when compared to those stratified into class 2 (54.0% lymphocytes; 53.4% buccal mucosa cells). Tissue-specific influences were also detected, with buccal mucosa trisomy levels being significantly correlated with IQ (P = 0.0094; both ectodermal derivatives), while congenital heart defects were significantly correlated with lymphocytes (P = 0.0286; both mesodermal embryonic derivatives). In conclusion, allowing for the distinction of two groups, we observed variation in phenotype, associated with the percentage of trisomic cells. We also observed tissue-specific effects on phenotype. The results of this study should enable geneticists and other health care professionals to provide information regarding optimal diagnostic approaches and anticipated clinical outcomes.

Diagnosis of ovine enzootic abortion, using a competitive ELISA based on monoclonal antibodies against variable segments 1 and 2 of the major outer membrane protein of Chlamydia psittaci serotype 1

OBJECTIVE

To develop and evaluate a competitive ELISA (cELISA) specific for detection of antibodies to abortion strains of Chlamydia psittaci and C pecorum that is based on monoclonal antibodies against the 2 segments. PROCEDURA: Monoclonal antibodies were screened for binding to ELISA plates coated with elementary bodies, and were selected on the basis of positive competition with experimentally produced sera against C psittaci and lack of competition with anti-C pecorum sera. The cELISA was evaluated with field sera, and the results were compared with those obtained by complement-fixation testing and by an ELISA containing solubilized outer membrane complexes (A-ELISA).

RESULTS

The cELISA detected 9 of 10 C psittaci-infected flocks (57/125 sera, 45.6%), and in 6 of 10 flocks (27.3% of the sera), it specified correctly the infecting chlamydial species. Regarding test sensitivity, the complement-fixation test detected 6 of 10 test-positive (19.2% of the sera) flocks, whereas 7 of 10 test-positive (48.8% of the sera) flocks were detected by use of the A-ELISA. The specificity of the test was satisfactory (100%), compared with the A-ELISA (72.2%).

CONCLUSIONS

The new cELISA is a sensitive and specific assay for antibodies against C psittaci abortion strains. It is rapid and easy to perform and does not require serum dilutions. The new cELISA is, therefore, suitable as a routine test for chlamydial diagnosis and seroepidemiologic studies.

Effect of iron chelation on the in-vitro growth of Leishmania promastigotes

The development of vaccines and drugs to control leishmaniasis is urgently needed. The presence of a leishmania transferrin receptor on the parasite suggests that an adequate supply of iron is needed for the life cycle of leishmania. We have investigated the effect of iron deprivation on the growth of leishmania promastigotes in vitro using an iron chelation approach. All chelators tested reduced the rate of promastigote multiplication in a dose-dependent fashion, whereas referrated ones did not. The hydroxypyridin-4-one chelators CP94 and L1 were found to be more efficient than desferrioxamine. We suggest that iron depletion may be an effective mechanism against leishmania infection.

"Hanseniaspora uvarum" the ultrastructural morphology of a rare ascomycete, isolated from oral thrush

Superficial fungal infections, including oral thrush, often affect aged full denture wearers and many individuals over 65 years old. The aim of this study was to examine the ultrastructural morphology of a very rare yeast, named Hanseniaspora uvarum/guillermondi, member of the Ascomycetes family, whose pathogenesis and behaviour is not widely known. The yeast was isolated from whitish lesions of the buccal mucosa of an 70 years old woman. The specimen was collected with a mouth swab and cultured in Sabourauds-Dextrose agar. The identification of the organism was performed on the Api 20C Aux system. The yeast colonies, after fixation in glutaraldehyde 3% for 1 hour were immersed in OsO4 1% solution for 1 hour and were "in tissue" stained with uranyl acetate. Ultrathin sections, were observed with TEM Jeol C x 100. Our ultrastructural observations showed that this yeast had a thick cell wall in which the outer surface appeared fuzzy. In some yeasts we observed multilayered intracytoplasmic membrane a figure which is not described as far as we know in any yeast. Many vacuoles were frequently observed in the cytoplasm and especially in the center of the oval shaped cells. Bilateral budding which form ascospores is identical for the morphology of this yeast.

[Laboratory technics for isolation and identification of the streptococci of the microbial flora of the mouth]

It is well known that many streptococcal species are members of the microbial flora of the mouth. We refer to the most important laboratory technics for collecting, transporting and storage, of streptococci, as well as to the manners of isolation, grouping and identification. We describe in detail the two newest of these methods that we use in our laboratory: a) The method "Streptex" by Wellcome Co., England, and b) The method "Api 20 Strep", by Api System S.A. France.

[Ultrastructural study of the action of concentrated solutions of chlorhexidine digluconate on cocci in salivary flora in vitro]

Chlorhexidine digluconate is a potent antibacterial compound widely used in stomatology. In this work the authors studied the ultrastructural alterations of cocci in salivary flora, treated "in vitro" with high concentrations of chlorhexidine digluconate (0.5%, 1% and 2%). The effect of chlorhexidine 0.5% on the cocci revealed rarefaction of the cytoplasm, ruptures of the cellular wall and alterations of the protoplasm in the form of "plasmoptysis" and "plasmolysis". Treatment of the cocci with higher concentrations (1% and 2%) of the drug caused a change in the appearance of the protoplasm, showing a general coagulation, damage of the cytoplasmic membrane and the cellular wall, malformation of the cell and disorganization of the nuclear chromatin. The ultrastructural alterations observed are in agreement with the results of preliminary biochemical studies.

[Descriptions and comparative changes of modifications on ultrastructure of cocci and bacteridium of saliva under "in vitro" influence of sparse and dense solutions of chlorhexidine di-gluconate]

In our investigation we have studied and analysed the modifications on the ultrastructure of the cocci and bacteridium of saliva under "in vitro" influence of sparse and dense solutions chlorhexidine di-gluconate. We noticed that the sparse solutions of the drug revealed ruptures of the cellular wall and of the cellular membrane as well as "plasmoptysis" and "plasmolysis". The protoplasm, showing a general coagulation, damage of the cytoplasmic membrane and the cellular wall and in concentrations of 1% and 2% we observed a disorganisation of the nuclear chromatin.

Characterization of cytochrome c3 from the thermophilic sulfate reducer Thermodesulfobacterium commune

A c3 type cytochrome has been purified from the thermophilic, non-spore-forming, sulfate-reducing bacterium Thermodesulfobacterium commune. The purified protein was homogeneous as judged by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, gel filtration, and isoelectric focusing. A pI of 6.83 was observed. The molecular weight of the cytochrome was estimated to be ca. 13,000 from both gel filtration and sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The hemoprotein exhibited absorption maxima at 530, 408.5, and 351 nm in the oxidized form and 551.5 (alpha band), 522.5 (beta band), and 418.5 nm (gamma band) in the reduced form. The extinction coefficients of T. commune cytochrome c3 were 130,000, 74,120, and 975,000 M-1 cm-1 at 551.5, 522.5, and 418.5 nm, respectively. It contains four hemes per molecule, on the basis of both the iron estimation and the extinction coefficient value of its pyridine hemochrome. The amino acid composition showed the presence of eight cysteine residues involved in heme binding. T. commune cytochrome c3 had low threonine, serine, and glycine contents and high glutamic acid and hydrophobic residue contents. The electrochemical study of T. commune cytochrome c3 by cyclic voltammetry and differential pulse polarography has shown that the cytochrome system behaves like a reversible system. Four redox potential values at Eh1 = -0.140 +/- 0.010 V, Eh2 = Eh3 = Eh4 = -0.280 +/- 0.010 V have been determined. T. commune cytochrome c3, which acts as the physiological electron carrier of hydrogenase, is similar in most respects to the multiheme low-potential cytochrome c3 which is characteristic of the genus Desulfovibrio.