Limited capacity of the nuclear matrix to bind telomere repeat binding factor TRF1 may restrict the proliferation of mortal human fibroblasts

The maintenance of telomere integrity is essential for prolonged cell proliferation, and failure in this mechanism is a most consistent manifestation of cellular senescence. In this study, we investigated the role of telomere repeat binding factor (TRF1) in the proliferation of human fibroblasts. TRF1 expression is upregulated in a large variety of immortal human cells and supports de novo telomere formation in a dose-dependent manner. These observations suggest that the suppression of TRF1 might limit telomere maintenance and thus the life span of mortal cells. However, primary fibroblasts ectopically overexpressing TRF1 were unable to avoid senescence. On the other hand, exogenously expressed TRF1 in primary fibroblasts neither supported de novo telomere formation nor bound to the nuclear matrix as tightly as observed in immortal cells that show upregulated TRF1 expression. We present evidence suggesting that mortal human cells lack specific ligand(s) that anchor TRF1 to the nuclear matrix and that this contributes to their limited lifespan.     

Inherited prothrombotic defects in Budd-Chiari syndrome and portal vein thrombosis: a study from North India

We studied 57 patients with Budd-Chiari syndrome (BCS) and 48 with portal vein thrombosis (PVT) for underlying inherited prothrombotic defects such as protein C, protein S, and antithrombin III deficiencies. Genetic mutations for factor V Leiden, prothrombin gene 20210A, and methyltetrahydrofolate reductase (MTHFR) C677T were studied in 29 patients in each group. Inherited prothrombotic defects were detected in 16 (28%) of 57 patients with BCS and 7 (15%) of 48 patients with PVT. Factor V Leiden mutation was the most common prothrombotic defect in BCS (5/29 [17%]) followed by protein C deficiency (7/57 [12%]) and protein S deficiency (4/57 [7%]), whereas in PVT, protein C deficiency was the most common inherited prothrombotic defect (4/48 [8%]) followed by protein S deficiency (2/48 [4%]). The factor V Leiden mutation was detected in only 1 (3%) of 29 cases of PVT. The heterozygous MTHFR C677T mutation was detected in 7 (24%) of 29 patients with BCS and 6 (21%) of 29 patients with PVT. Antithrombin III deficiency, homozygous MTHFR C677T mutation, and prothrombin G20210A mutation were not detected in any patients.     

Drosophila glob1 is required for the maintenance of cytoskeletal integrity during oogenesis

Background: Hemoglobins (Hbs) are evolutionarily conserved heme‐containing metallo‐proteins of the Globin protein family that harbour the characteristic “globin fold.” Hemoglobins have been functionally diversified during evolution and their usual property of oxygen transport is rather a recent adaptation. Drosophila genome possesses three globin genes (glob1, glob2, and glob3), and we have reported earlier that adequate expression of glob1 is required for various aspects of development, as well as to regulate the cellular level of reactive oxygen species (ROS). The present study illustrates the explicit role of Drosophila globin1 in progression of oogenesis. Results: We demonstrate a dynamic expression pattern of glob1 in somatic and germ cell derivatives of developing egg chambers during various stages of oogenesis, which largely confines around the F‐actin‐rich cellular components. Reduced expression of glob1 leads to various types of abnormalities during oogenesis, which were primarily mediated by the inappropriately formed F‐actin‐based cytoskeleton. Our subsequent analysis in the somatic and germ line clones shows cell autonomous role of glob1 in the maintenance of the integrity of F‐actin‐based cytoskeleton components in the somatic and germ cell derivatives. Conclusions: Our study establishes a novel role of glob1 in maintenance of F‐actin‐based cytoskeleton during progression of oogenesis in Drosophila. Developmental Dynamics 245:1048–1065, 2016. © 2016 Wiley Periodicals, Inc.     

Susceptibility of diverse primary HIV isolates with varying co-receptor specificity's to CXCR4 antagonistic compounds

The chemokine receptors CCR5 and CXCR4 are an obvious target for HIV therapies. Two compounds, T-22 and AMD-3100, have been shown to inhibit infection of CXCR4-using HIV-1 isolates. The specificity of T-22 and AMD-3100 was further confirmed by their ability to block entry of HIV-1 in GHOST-CXCR4 transfected cells with no effect on viral entry in the GHOST-CCR5 cells. The ability of T-22 to block replication of diverse HIV-1 isolates (group M, subtypes A, B, D, E, and F as well as group O) and HIV-2 primary isolates with varying coreceptor specificities ranging from exclusive CCR5 usage to multiple coreceptor usage was examined in detail. T-22 was found to be highly effective (>90%) at blocking infection of diverse HIV-1 (subtypes A-F, and group O) and HIV-2 isolates that use multiple coreceptors in human PBMCs homozygous for a 32-bp deletion in CCR5 (CCR5-/-), but less effective in CCR5 +/+ PBMCs. Additionally, sequential primary HIV-1 isolates obtained from a longitudinal cohort who had switched from single coreceptor usage to a broad range of multiple receptors could be blocked effectively by both T-22 and AMD-3100 in CCR5-/- PBMCs. Our data suggest that CXCR4 antagonistic compounds are highly effective in blocking the entry of X4-tropic HIV-1, and that these compounds could be a useful additive to current anti-retroviral therapy for clinical management of HIV disease.     

BIA-ALCL diagnosis on CytoLyt fixed ThinPrep,cell block and immunohistochemistry

Breast implant associated anaplastic large cell lymphoma (BIA-ALCL) is an emergent rare T cell non-Hodgkin lymphoma arising in association with a breast implant, particularly textured ones. Recent guidelines list cytopathological examination as the first essential step for diagnosis, routinely followed by CD30 immunohistochemistry (IHC) and flow cytometry (FC) for a T cell clone. The majority of BIA-ALCL literature regarding cytopathological evaluation describes morphology based on various preparation methods limited to cytospins and smears with the exception of at least one case report detailing cytomorphological and IHC findings on ThinPrep. This case report details initial diagnosis of BIA-ALCL rendered with CytoLyt prepared ThinPrep and cell block, including the specific antibodies used for IHC. The ThinPrep slide showed numerous singly dispersed large, atypical cells with abundant cytoplasm containing irregular nuclei with dispersed chromatin and prominent nucleoli in a background of macrophages, inflammatory cells and granular debris. TIA-1 and CD30 along with other T-cell markers, including specific antibodies, remains immunoreactive in tissue collected in CytoLyt solution. Cell size reduction, artifactual lymphoid cell aggregation and prominent nucleoli in benign and reactive conditions are among other ThinPrep cellular alterations pathologists should bear in mind.     

Detection of Human T-Lymphotropic Virus (HTLV) tax Sequences in New York City Blood Donors Seronegative for HTLV Types 1 and 2

A potential public health concern is the reported detection of the human T-lymphotropic virus (HTLV) tax gene in the lymphocytes of up to 11% of a low-risk group of New York City blood donors (NYBD). This study aimed to independently confirm the prevalence of HTLV tax sequences in 293 NYBD. All NYBD tested negative for antibodies to HTLV types 1 and 2 and HTLV Tax. HTLV tax sequences were not detected in the NYBD lymphocytes. These data demonstrate the lack of HTLV-1 tax in this group of NYBD at low risk for HTLV infection.     

Plasmodium falciparum signal peptidase is regulated by phosphorylation and required for intra-erythrocytic growth

The human malaria parasite Plasmodium falciparum exports a variety of its proteins through its endoplasmic reticulum (ER) based secretory pathway in order to survive in the host erythrocyte. Signal peptidases are membrane-bound endopeptidases and have an important role in the transport and maturation of these parasite proteins. Prokaryotic signal peptidases are indispensable enzymes required for the removal of N-terminal signal peptide from the secretory proteins. Eukaryotic signal peptidases exist as multimeric protein complex in the ER and the catalytic subunit of this complex catalyzes removal of the N-terminal signal peptide from preproteins. All the signal peptidases contain five regions of high-sequence similarity referred to as boxes A-E. Here we report characterization of the catalytic subunit of signal peptidase complex (SPC) from P. falciparum. This protein designated as PfSP21 shows homology with the similar subunit from other sources and contains all the conserved boxes A-E. PfSP21 is able to cleave the peptide substrate containing the signal peptidase cleavage site. PfSP21 is phosphorylated by protein kinase C and its enzyme activity was upregulated after this phosphorylation. Immunofluorescence assay studies revealed that PfSP21 is localized in the ER of P. falciparum. PfSP21 dsRNA specifically inhibits the growth of P. falciparum in culture and this inhibition is most likely due to the decrease in the amount of endogenous PfSP21 protein. These studies demonstrate the characterization of a functional subunit of SPC from P. falciparum and should make an important contribution in our better understanding of the complex process of protein translocation in the parasite.     

Spectrum of anemia in pregnant Indian women and importance of antenatal screening

Anemia is a common health problem but control of anemia in pregnant women is less well studied. The purpose was to study prevalence of anemia in young pregnant women, correlate with indices and study significance of identification of hemoglobinopathies. Of the 120 pregnant women, Hb was less than 8 g% in 58 (44.2%). Seventy-eight (65%) had iron deficiency, 22 (18.3%) had dimorphic anemia, and 14 (11.6%) had hemolytic anemia. Megaloblastic anemia was present in 6 (5%). Of hemolytic anemia, 50% were thalassemia trait. MCV< 76 fl was observed in 88 (73.3 %) cases. MCV<76 fl and MCH < 27 pg had 100 % sensitivity and 28.7 % specificity for screening of beta-thalassemia trait. NESTROFT had comparable sensitivity but lower specificity (14.9%). Sixty-three percent (60/78) of IDA had increased RDW whereas 78 % (11/14) of hemolytic anemia had RDW value in normal range (p value< 0.05). MCV/RBC of <14 was more specific parameter (96.8%) for beta-thalassemia trait. Four high-risk couples were identified. Thus, moderate to severe anemia was observed in most pregnant women. Hemoglobinopathies should be screened in antenatal clinics to identify the couples that would need a prenatal test. A lower MCV/RBC with RDWin the normal range may be useful in screening for thalassemia trait in pregnant women.     

Sublingual misoprostol versus intravenous oxytocin in prevention of post-partum hemorrhage

Background

Post-partum hemorrhage (PPH) is the most common direct cause of maternal mortality and timely intervention can save many lives.

Objective

To compare the effectiveness of sublingual misoprostol to intravenous oxytocin in preventing post-partum hemorrhage in low risk vaginal birth.

Methods

One hundred patients with no risk factor for PPH were randomly allocated to receive 600 μg misoprostol administered sublingually or 10 IU of intravenous oxytocin immediately after the delivery of baby. Main outcome measures were post-partum blood loss, drop in hemoglobin in 24 h, duration of third stage of labor, and drug-related adverse effects.

Results

Mean age, parity and gestational age were similar in both groups. Mean blood loss was significantly lower in oxytocin group (114.28 ± 26.75 versus 149.50 ± 30.78 ml; p = 0.00). Drop in hemoglobin was 0.31 ± 0.16 versus 0.49 ± 0.21 g% (p = 0.01) in oxytocin and misoprostol group, respectively. Duration of third stage labor was shorter in oxytocin group (median 5 min, IQR: 4.5–5.5 versus 5.5 min, IQR: 5–6 min, p < 0.01). Although fever and shivering were common adverse effects with misoprostol but were not clinically significant.

Conclusion

Intravenous oxytocin is more efficacious than sublingual misoprostol in preventing PPH in institutional deliveries.