373 research outputs found

    A novel alpha kinase EhAK1 phosphorylates actin and regulates phagocytosis in Entamoeba histolytica

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    Phagocytosis plays a key role in nutrient uptake and virulence of the protist parasite Entamoeba histolytica. Phagosomes have been characterized by proteomics, and their maturation in the cells has been studied. However, there is so far not much understanding about initiation of phagocytosis and formation of phagosomes at the molecular level. Our group has been studying initiation of phagocytosis and formation of phagosomes in E. histolytica, and have described some of the molecules that play key roles in the process. Here we show the involvement of EhAK1, an alpha kinase and a SH3 domain containing protein in the pathway that leads to formation of phagosomes using red blood cell as ligand particle. A number of approaches, such as proteomics, biochemical, confocal imaging using specific antibodies or GFP tagged molecules, expression down regulation by antisense RNA, over expression of wild type and mutant proteins, were used to understand the role of EhAK1 in phagocytosis. EhAK1 was found in the phagocytic cups during the progression of cups, until closure of phagosomes, but not in the phagosomes themselves. It is recruited to the phagosomes through interaction with the calcium binding protein EhCaBP1. A reduction in phagocytosis was observed when EhAK1 was down regulated by antisense RNA, or by over expression of the kinase dead mutant. G-actin was identified as one of the major substrates of EhAK1. Phosphorylated actin preferentially accumulated at the phagocytic cups and over expression of a phosphorylation defective actin led to defects in phagocytosis. In conclusion, we describe an important component of the pathway that is initiated on attachment of red blood cells to E. histolytica cells. The main function of EhAK1 is to couple signalling events initiated after accumulation of EhC2PK to actin dynamics

    Maternal and perinatal outcome in instrumental vaginal deliveries over 5 years: a retrospective study

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    Background: Due to fear of trauma and less skill, use of instrumental vaginal delivery (IVD) is decreasing every year and incidence of caesarean section is increasing. Caesarean section is a major surgery associated with increased morbidity and mortality. This study evaluates the incidence of instrumental vaginal delivery and associated maternal and perinatal outcome. Methods: This observational retrospective study was carried out in full term antenatal patients in labour with vertex presentation who had undergone operative vaginal deliveries during the study period from January 2017 to December 2021 at G.C.S. Hospital. Data were obtained from the hospital records and analysed which included the age, parity, incidence, indication, the APGAR scores of the babies and complications in the patient. Results: Incidence of instrumental deliveries was found to be 1.98%. Most common indications for IVD were prolonged second stage of labour followed by foetal distress and post-dated pregnancy. Most common maternal complication was perineal tears and most common perinatal complication was neonatal intensive care unit (NICU) admission. Conclusions: The decision to proceed with an operative vaginal delivery when a spontaneous vaginal delivery is not possible must be based upon maternal and foetal factors. Most common maternal complications were perineal tears, cervical tears, episiotomy extension, vaginal laceration and atonic postpartum hemorrhage (PPH). Most common neonatal complications were NICU admission most commonly for neonatal hyperbilirubinemia.

    LESSENING OF ISSUES REGARDING POWER QUALITY IN ELECTRICAL POWER DEVICES

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    In the recent times, issues of power quality are extremely vital for customers and hence for the devices of custom power, dynamic voltage restorer is employed to lessen the issues of power quality. Dynamic voltage restorer device manages active power flow and includes minute cost when measured to others. By dynamic voltage restorer device, introduced on feeder of load, line voltage is returned to its common level within few milliseconds as a result preventing power disruption. We carry out a control method of hysteresis voltage for building purpose of switching pulses for the inverter of dynamic system of voltage restorer. By added benefits of low expenditure as well as simple functioning, our proposed system is tremendously accepted for power supply of microprocessors. The proposed method of hysteresis voltage presents quick transient response without additional loop compensation

    Study of metastasis in lymph node by fine needle aspiration cytology: our institutional experience

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    Background:Fine needle aspiration cytology (FNAC) is a reliable as well as an inexpensive diagnostic method. It is suitable for the developing countries for the diagnosis of lymphadenopathy at any approachable site. Fine needle aspiration cytology not only confirms the presence of metastatic disease but also, in most cases, gives the clue regarding the origin of the primary tumor, prognosis as well in the management of patient for staging purposes. The aim of the study was to detect and diagnose metastasis in lymph nodes. Methods:A study was done of all metastatic lymph node lesions reported in Department of Pathology, Govt. Medical College, Surat from May 2011 to April 2012.Results:A total of 2355 cases of fine needle aspiration cytology were carried out of which 580 cases were of lymph node. Cytology results were positive for metastasis in 157 specimens (27.06%). The most common site was cervical lymph nodes. Maximum numbers of cases of metastatic tumors were in 41-50 yrs age group. There were 115 males and 42 females with a male predominance (Male:Female= 2.8:1). The most common malignancy was squamous cells carcinoma, seen in 118 cases (75.15%), followed by metastatic mammary carcinoma (13 cases, 8.29%). In 26 cases out of 580 cases, histopathological confirmation was done and diagnostic accuracy of FNAC was 100%. Conclusions:Fine needle aspiration cytology of lymphadenopathy is a useful tool in diagnosing metastatic lesions with good certainty

    A Review of the Mechanism of Antagonism of N-methyl-D-aspartate Receptor by Ketamine in Treatment-resistant Depression

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    The biochemical processes involved in depression go beyond serotonin, norepinephrine, and dopamine. The N-methyl-D-aspartate (NMDA) receptor has a major role in the neurophysiology of depression. Ketamine, one of the prototypical NMDA antagonists, works rapidly in controlling depressive symptoms, including acutely suicidal behavior, by just a single injection. Ketamine may rapidly increase the glutamate levels and lead to structural neuronal changes. Increased neuronal dendritic growth may contribute to synaptogenesis and an increase in brain-derived neurotrophic factor (BDNF). Activation of the mechanistic target of rapamycin (mTOR), as well as increased levels of BDNF, may increase long-term potentiation and result in an improvement in the symptoms of depression. The mechanisms of ketamine’s proposed effect as an off-label treatment for resistant depression are outlined in this paper

    Synthesis, characterisation and photochemistry of PtIV pyridyl azido acetato complexes

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    PtII azido complexes [Pt(bpy)(N3)2] (1), [Pt(phen)(N3)2] (2) and trans-[Pt(N3)2(py)2] (3) incorporating the bidentate diimine ligands 2,2′-bipyridine (bpy), 1,10-phenanthroline (phen) or the monodentate pyridine (py) respectively, have been synthesised from their chlorido precursors and characterised by X-ray crystallography; complex 3 shows significant deviation from square-planar geometry (N3–Pt–N3 angle 146.7°) as a result of steric congestion at the Pt centre. The novel PtIV complexes trans, cis-[Pt(bpy)(OAc)2(N3)2] (4), trans, cis-[Pt(phen)(OAc)2(N3)2] (5), trans, trans, trans-[Pt(OAc)2(N3)2(py)2] (6), were obtained from 1–3via oxidation with H2O2 in acetic acid followed by reaction of the intermediate with acetic anhydride. Complexes 4–6 exhibit interesting structural and photochemical properties that were studied by X-ray, NMR and UV-vis spectroscopy and TD-DFT (time-dependent density functional theory). These PtIV complexes exhibit greater absorption at longer wavelengths (ε = 9756 M−1 cm−1 at 315 nm for 4; ε = 796 M−1 cm−1 at 352 nm for 5; ε = 16900 M−1 cm−1 at 307 nm for 6, in aqueous solution) than previously reported PtIV azide complexes, due to the presence of aromatic amines, and 4–6 undergo photoactivation with both UVA (365 nm) and visible green light (514 nm). The UV-vis spectra of complexes 4–6 were calculated using TD-DFT; the nature of the transitions contributing to the UV-vis bands provide insight into the mechanism of production of the observed photoproducts. The UV-vis spectra of 1–3 were also simulated by computational methods and comparison between PtII and PtIV electronic and structural properties allowed further elucidation of the photochemistry of 4–6

    Power and the durability of poverty: a critical exploration of the links between culture, marginality and chronic poverty

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    Angiogenesis in urinary bladder carcinoma as defined by microvessel density (MVD) after immunohistochemical staining for Factor VIII and CD31

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    Background: Among the patients with bladder cancer, a group is still at risk of disease recurrence, progression, and death from their cancer after curative treatment. Angiogenesis is a crucial pathogenic mechanism for this type of urothelial carcinoma and is a potential therapeutic target. Objectives: To quantify tumor angiogenesis in bladder cancer and determine whether it correlates with tumor stage and grade. Patients and methods: A series of 42 archival samples from carcinomas of the urinary bladder were graded, staged, and analyzed for microvessel density (MVD) by a double immunohistochemical technique using Factor VIII (FVIII) and CD31 antibodies. The correlation between MVD and histopathological grade and tumor stage was evaluated. Results: FVIII and CD31 immunoreactivity was observed in 100% of cases and more intensely with CD31. Significantly higher MVD was determined in invasive tumors than in superficial tumors (p<0.05). MVD increased with tumor grade and stage (p<0.05); MVD was not affected by age or sex of the patients. Conclusion: These data demonstrate that MVD in bladder carcinoma correlates with the tumor grade and stage. Quantification of tumor angiogenesis may allow selection of the type of treatment for bladder cancer patients
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