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31.
Awasthi S Singhal SS Pandya U Gopal S Zimniak P Singh SV Awasthi YC 《Toxicology and applied pharmacology》1999,155(3):215-226
We have recently demonstrated mutually inhibitory ATP-dependent transport of dinitrophenyl-S-glutathione (DNP-SG) and doxorubicin by DNP-SG ATPase purified from human erythrocyte membranes (S. Awasthi et al., 1998a,b). Our previous studies indicate a broad substrate specificity for this transport mechanism, including some P-glycoprotein substrates. Present studies were carried out to determine whether colchicine (COL), a classical P-glycoprotein substrate, could be transported by purified human erythrocyte DNP-SG ATPase reconstituted in artificial liposomes. We also investigated whether leukotriene C4 (LTC4), an endogenous proinflammatory glutathione-conjugate derived from arachidonic acid, would inhibit colchicine transport. Uptake of COL was compared in proteoliposomes reconstituted with the purified DNP-SG ATPase as well as control liposomes in the presence or absence of ATP. Increased colchicine uptake was observed upon addition of ATP to proteoliposomes, but not control liposomes. Uptake was linear with respect to the amount of vesicle protein used. Sensitivity to osmolarity was consistent with intravesicular COL accumulation. The ATP-dependent colchicine uptake was sensitive to temperature in a manner consistent with a protein-mediated transport process with activation energy of 7.3 kcal/mol. Time-dependent COL uptake by proteoliposomes in the presence of ATP was consistent with a single compartment model with an apparent rate constant of 0.21 +/- 0.02 min-1. Kinetic studies indicated a saturable behavior with respect to ATP (Km 2.3 +/- 0.7 mM) and colchicine (Km 4.3 +/- 0.2 microM). LTC4 was found to be a competitive inhibitor of COL transport (Kis 16.4 microM). Since DNP-SG ATPase is present in many tissues, it may play an important role in determining colchicine accumulation in cells. Increased LTC4 would tend to increase cellular COL accumulation. 相似文献
32.
This paper describes the use of the bromodeoxyuridine/propidium iodide method to assess the effects of bioactive and cytotoxic agents on the kinetic characteristics of acute myelogenous leukemia cells. By careful selection of gates, the following parameters can be measured simultaneously using only 50,000 cells: the proportion of cells in S-phase, the distribution of cells within the S-phase compartment, the relative rate of DNA synthesis, the relative distribution of S-phase times, the proportion of S0 cells, and the proportion of cells in G1 and G2/M. This method was used to demonstrate that while retinoic acid, alpha-interferon, and cytosine arabinoside may all "inhibit" DNA synthesis, the actual effects of these agents differ. Retinoic acid appears to arrest cells in G1 without affecting the rate of DNA synthesis, while alpha-interferon and cytosine arabinoside "inhibit" DNA synthesis by reducing the rate of synthesis per se. 相似文献
33.
A 4 year old girl with neurofibromatosis type 1 (NF1) was referred for hypertension. An aortogram showed narrowing of the left main renal artery. An angiogram three and a half years later showed coarctation of the abdominal aorta. She underwent aortoplasty but the stenosis recurred. Vascular involvement in NF1 may be progressive and requires long term follow up. 相似文献
34.
P. M. Parikh S. H. Advani J. S. Nadkarni S. Kulkarni G. Kapoor P. S. R. K. Sastry M. Anand T. K. Saikia R. Gopal 《Cancer investigation》1997,15(4):326-328
Hepatic veno-occlusive disease (VOD) is the second most common cause of death after autologous bone marrow transplantation (ABMT). A patient with multiple myeloma undergoing ABMT developed classic features of hepatic VOD. He responded to treatment with pentoxiphyllin. Serum tumor necrosis factor (TNF) levels showed remarkable correlation with the severity of VOD and response to therapy. 相似文献
35.
G. K. Maheshwari H. A. Baboo Usha Gopal M. K. Wadhwa 《Indian journal of otolaryngology and head and neck surgery》2004,56(2):138-141
Sarcomas constitute fewer than 1% of the head and neck cancers. They represent less than 1% of laryngeal cancers. Primary
rhabdomyosarcoma of the larynx is an extremely rare malignancy. The available literature on this medical oddity is in the
form of isolated case reports only. The purpose of this article is to add another case of primary rhabdomyosarcoma of a rare
site, the larynx, of which only 36 cases have so far been reported in the world literature. The present patient, an eighteen-year-old
boy is only the third case being reported from India among all reported cases of rhabdomyosarcoma of the larynx in the world
literature. 相似文献
36.
I. E. Ezeagu A. G. Gopal Krishna S. Khatoon L. R. Gowda 《Ecology of food and nutrition》2004,43(4):295-305
Analysis showed the seeds of Adenanthera pavonina contained appreciable amounts of proteins (29.44g/100g), crude fat (17.99g/100g), and minerals, comparable to commonly consumed staples. Total sugar was low (8.2g/100g) while starch (41.95g/100g) constitutes the major carbohydrates. Low levels of antinutrients were reported and methionine and cystine were the most deficient amino acids. Linoleic and oleic acids make up 70.7 percent of the total fatty acids. Free fatty acid levels were relatively high but peroxide and saponification values of 29.6mEqkg-1 and 164.1mgKOHg-1respectively point to a resemblance to oils processed for food. It was concluded that A. pavonina seeds represent a potential source of oil and protein that could alleviate shortages. 相似文献
37.
Brain undergoes neurodegeneration when excess free radicals overwhelm antioxidative defense systems during senescence, head trauma and/or neurotoxic insults. A site-specific accumulation of ferrous citrate-iron complexes in the substantia nigra dopaminergic neurons could lead to exaggerated dopamine turnover, dopamine auto-oxidation, free radical generation, and oxidant stress. Eventually, this iron-catalyzed dopamine auto-oxidation results in the accumulation of neuromelanin, a progressive loss of nigral neurons, and the development of Parkinson's disease when brain dopamine depletion is greater than 80%. Emerging evidence indicates that free radicals such as hydroxyl radicals ((.-)OH) and nitric oxide ((.-)NO) may play opposite role in cell and animal models of parkinsonism. (.-)OH is a cytotoxic oxidant whereas oNO is an atypical neuroprotective antioxidant. (.-)NO and S-nitrosoglutathione (GSNO) protect nigral neurons against oxidative stress caused by 1-methyl-4-phenylpyridinium (MPP(+)), dopamine, ferrous citrate, hemoglobin, sodium nitroprusside and peroxynitrite. MPP(+), the toxic metabolite of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP), increases the nigral uptake of iron complexes and dopamine overflow leading to the generation of (.-)OH, protein oxidation, lipid peroxidation, and associated retrograde degeneration. In addition to GSNO, MPP(+)-induced oxidative neurotoxicity can be prevented by antioxidants including selegiline, 7-nitroindazole, 17beta-estradiol, melatonin, alpha-phenyl-tert-butylnitrone and U78517F. Similar to selegiline, 7-nitroindazole is a MAO-B inhibitor, which blocks the bio-activation of MPTP and oxidative stress. Freshly prepared but not light exposed, (.-)NO-exhausted GSNO is about 100 times more potent than the classic antioxidant glutathione. Via S-nitrosylation, GSNO also inhibits proteolysis and cytotoxicity caused by caspases and HIV-1 protease. Furthermore, in addition to protection against serum deprivation stress, the induction of neuronal NOS1 in human cells increases tolerance to MPP(+)-induced neuro-toxicity since newly synthesized (.-)NO prevents apoptosis possibly through up-regulation of bcl-2 and down regulation of p66(shc). In conclusion, reactive oxygen species are unavoidable by-products of iron-catalyzed dopamine auto-oxidation, which can initiate lipid peroxidation, protein oxidation, DNA damage, and nigral loss, all of which can be prevented by endogenous and exogenous (.-)NO. Natural and man-made antioxidants can be employed as part of preventative or neuroprotective treatments in Parkinson's disease and perhaps dementia complexes as well. For achieving neuroprotection and neuro-rescue in early clinical parkinsonian stages, a cocktail therapy of multiple neuroprotective agents may be more effective than the current treatment with extremely high doses of a single antioxidative agent. 相似文献
38.
The foramen ovale is usually obliterated following establishment of the adult circulation but remains patent in 25% of individuals. This potential communication between the venous and arterial circulations can allow thromboembolic material to bypass the lungs and enter the systemic circulation. We report two cases of paradoxical embolization through a patent foramen ovale following acute large pulmonary embolism (PE) and discuss the factors that predispose to paradoxical embolization following PE. 相似文献
39.
Tisungane Mvalo Hillary M. Topazian Portia Kamthunzi Jane S. Chen Isobel Kambalame Pilirani Mafunga Noel Mumba Msandeni Chiume Khadija Paseli Gerald Tegha Wiza Kumwenda J. Brett Heimlich Graham Ellis Nigel Key Satish Gopal Irving Hoffman Kenneth I. Ataga Kate D. Westmoreland 《Pediatric blood & cancer》2019,66(11)
40.
Ashley Sharp Berit Muller-Pebody Andre Charlett Bharat Patel Rebecca Gorton Jonathan Lambourne Martina Cummins Adela Alcolea-Medina Mark Wilks Robin Smith Damien Mack Susan Hopkins Andrew Dodgson Phillipa Burns Nelun Perera Felicia Lim Gopal Rao Priya Khanna Elizabeth Johnson Andrew Borman Silke Schelenz Rebecca Guy Joanna Conneely Rohini J Manuel Colin S Brown 《Euro surveillance : bulletin européen sur les maladies transmissibles = European communicable disease bulletin》2021,26(8)
Background Candida auris is an emerging multidrug-resistant fungal pathogen associated with bloodstream, wound and other infections, especially in critically ill patients. C. auris carriage is persistent and is difficult to eradicate from the hospital environment.AimWe aimed to pilot admission screening for C. auris in intensive care units (ICUs) in England to estimate prevalence in the ICU population and to inform public health guidance.MethodsBetween May 2017 and April 2018, we screened admissions to eight adult ICUs in hospitals with no previous cases of C. auris, in three major cities. Swabs were taken from the nose, throat, axilla, groin, perineum, rectum and catheter urine, then cultured and identified using matrix-assisted laser desorption/ionisation time-of-flight mass spectrometry (MALDI-TOF MS). Patient records were linked to routine ICU data to describe and compare the demographic and health indicators of the screened cohort with a national cohort of ICU patients admitted between 2016 and 2017.ResultsAll C. auris screens for 921 adults from 998 admissions were negative. The upper confidence limit of the pooled prevalence across all sites was 0.4%. Comparison of the screened cohort with the national cohort showed it was broadly similar to the national cohort with respect to demographics and co-morbidities.ConclusionThese findings imply that C. auris colonisation among patients admitted to ICUs in England is currently rare. We would not currently recommend widespread screening for C. auris in ICUs in England. Hospitals should continue to screen high-risk individuals based on local risk assessment. 相似文献