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1.
Clin Ter ; 172(2): 151-157, 2021 Mar 15.
Article in English | MEDLINE | ID: mdl-33763678

ABSTRACT

BACKGROUND AND AIM: Appropriate end of life (EOL) management in Internal Medicine wards is challanging. The aim of this study was to analyze the burden of an educational program on EOL management in a Internal Medicine ward. Materials and methods: We retrospectively analysed characteristics and management of patients consecutively died in an italian Internal Medicine ward along one year. We compared demographic, co-morbidity, pharmacological treatment in the last 48-hours of life and procedures during hospital stay in patients died six months before and after an educational program on palliative cares and EOL management addressed to a team of physicians and nurses. RESULTS: Study population was composed by 354 patients (190 females), with mean age ± DS 83.5 ± 10.6 years, one half admitted after the educational program. Eighty-four percent of deaths was exepected in the last 48 hours before exitus. Demographic characteristics and causes of hospitalization were not different before and after educational program. After the educational program the sharing of palliative care program with patient, relatives and/or caregivers (97.7% vs 85.8%, p=0.0001) and written order to withdrawal vital parameters relevation (39.5% vs 22%, p=0.0005) significantly increased, while difference in pharmacological classes prescribed in the last 48 hours of life was not find. Blood (54.8% vs 67.2%, p=0.0219) and arterial gas analysis (28.8% vs 39.5%, p=0.0435) samples in the last 48 hours of life were significantly reduced. Radiological and/or endoscopic examinations, red cells or platelets transfusion were reduced and palliative therapy was increased, despite difference between the two periods was not statistically significant. CONCLUSION: Educational program in Internal Medicine wards aimed to improve skills could contribute to make EOL management more appropriate and patient-oriented and it should be strongly encour-aged.


Subject(s)
Education, Medical, Continuing/organization & administration , Education, Nursing, Continuing/organization & administration , Hospitals , Internal Medicine/education , Terminal Care/organization & administration , Aged , Aged, 80 and over , Caregivers , Comorbidity , Death , Female , Humans , Italy , Length of Stay , Male , Palliative Care/organization & administration , Retrospective Studies , Socioeconomic Factors
2.
Biochim Biophys Acta ; 1771(2): 139-46, 2007 Feb.
Article in English | MEDLINE | ID: mdl-17234448

ABSTRACT

9-hydroxystearic acid (9-HSA) belongs to the class of endogenous lipid peroxidation by-products that greatly diminish in tumors, causing as a consequence the loss of one of the control mechanisms on cell division. We have previously shown that 9-HSA controls cell growth and differentiation by inhibiting histone deacetylase 1 (HDAC1) activity. In this paper our attention has not only been focused on HDAC1 inhibition but also on the hyperacetylation of other substrates such as p53, that is involved in inducing cell cycle arrest and/or apoptosis, and whose activity and stability are known to be regulated by posttranslational modifications, particularly by acetylation at the C-terminus region. 9-HSA administration to U2OS, an osteosarcoma cell line p53 wt, induces a growth arrest of the cells in G2/M and apoptosis via a mitochondrial pathway. In particular hyperacetylation of p53 induced by the HDAC1 inhibitory activity of 9-HSA has been demonstrated to increase Bax synthesis both at the transcriptional and the translational level. The subsequent translocation of Bax to the mitochondria is associated to a significant increase in caspase 9 activity. Our data demonstrate that the effects of 9-HSA on U2OS correlate with posttranslational modifications of p53.


Subject(s)
Osteosarcoma/metabolism , Signal Transduction , Stearic Acids/pharmacology , Tumor Suppressor Protein p53/metabolism , Acetylation , Apoptosis , Cell Line, Tumor , Cell Proliferation , Cyclin-Dependent Kinase Inhibitor p21/metabolism , Humans , Promoter Regions, Genetic , Stearic Acids/toxicity , bcl-2-Associated X Protein/genetics
3.
Water Sci Technol ; 58(9): 1789-96, 2008.
Article in English | MEDLINE | ID: mdl-19029720

ABSTRACT

This paper deals with the case of one of the most important industrial application of membrane technology in the world: the upgrading of the main industrial wastewater treatment plant (WWTP) of the petrochemical site of Porto Marghera, Northern Italy, completed on December 2005 and tested on September 2006. It describes the principal interventions of the plant upgrading and it discusses the removal obtained during the test periods for conventional pollutants as well as for micropollutants. The plant upgrading consisted of a series of improvements of the existing industrial WWTP, in order to increase the removal efficiency of the total suspended solids and the associate removal of ten micropollutant compounds, the so called forbidden substances. The most important intervention was the conversion of the existing activated sludge section into a membrane biological reactor, in order to guarantee adherence to the severe limits imposed by the special law issued to protect the Venice Lagoon, with particular reference to the mentioned 10 forbidden compounds. The experimental results and the numerous test-runs conducted confirmed the respect of the legal limits for the pollutants in the final effluent as well of the required removal rates for the different parameters. Therefore, the upgraded treatment plant was declared agreeing with the approved design.


Subject(s)
Environmental Restoration and Remediation/methods , Industrial Waste , Water Pollutants/isolation & purification , Italy , Metals/isolation & purification , Solvents/isolation & purification
4.
Clin Ter ; 169(6): e287-e291, 2018.
Article in English | MEDLINE | ID: mdl-30554250

ABSTRACT

BACKGROUND: Guidelines recommend triple therapy (TT) with ACE inhibitors or ARBs, beta-blockers and mineralcorticoid receptor antagonists in symptomatic heart failure patients with ejection fraction <35 % (HFrEF). Nevertheless, many patients remain untreated. This study was aimed to evaluate the use of TT in HFrEF patients discharged from internal medicine wards of Tuscany, Italy. METHODS AND RESULTS: We analyzed the database of a multicenter observational study which included 770 patients consecutively hospitalized for HF in 32out of 36 Internal Medicine Units of Tuscany, Italy. The value of ejection fraction was available in 490 of the 725 patients discharged alive. Of the 117 patients with HFrEF, only 46 (39.3%) were on TT at discharge while 71 (60.7%) were not. In the latter group we observed a significantly greater percentage of patients with cognitive deficit (25.3% vs 10.8%, p=0.05). In the same group there was a slightly greater percentage of patients with hypertension (61.9% vs 58.6%), diabetes (43.6% vs 36.9%), GFR<60 ml/min (74.6% vs 67.3%), anemia (52.1% vs 45.6%) and atrial fibrillation (40.8% vs 34.7%), but the differences were not statistically significant. CONSLUSIONS: These results indicate that TT is underutilized in internal medicine wards of Tuscany. Untreated patients had a greater rate of cognitive deficit and were probably sicker, more complex and fragile.


Subject(s)
Drug Utilization/statistics & numerical data , Guideline Adherence/statistics & numerical data , Heart Failure/drug therapy , Stroke Volume/physiology , Adrenergic beta-Antagonists/therapeutic use , Aged , Angiotensin Receptor Antagonists/therapeutic use , Angiotensin-Converting Enzyme Inhibitors/therapeutic use , Cross-Sectional Studies , Female , Heart Failure/physiopathology , Humans , Italy , Male , Middle Aged , Patient Discharge , Practice Guidelines as Topic , Retrospective Studies
5.
J Chromatogr A ; 1129(1): 73-81, 2006 Sep 29.
Article in English | MEDLINE | ID: mdl-16887128

ABSTRACT

The application of reversed-phase high-pressure liquid chromatography under gradient conditions and electrospray ion trap mass spectrometry (LC-ESI-MS) to the analysis of global modification levels of core histones is described. The optimised LC-ESI-MS method was applied for the first time to the characterisation of histones extracted from HT29, a human colon cancer cell line. Eight histones (H1-1, H1-2, H2A-1, H2A-2, H2B, H3-1, H3-2, H4) were separated on a C4 stationary phase with complete resolution, never reached in previous HPLC-MS methods, by using a gradient elution with the combined presence of heptafluorobutyric acid and formic acid as acidic modifiers in the mobile phase. Heptafluorobutyric acid was found to improve selectivity, whereas the presence of formic acid decreased ion suppression. Histones eluted from the column were detected with an ion trap mass spectrometer with an electrospray source. The peak averaged mass spectra were reconstructed by Mag Tran 1.0 software and the mass of the various isoforms of histones were derived. Method validation was conducted by performing the same sample analysis by coupling LC-ESI to a quadrupole-time-of-flight mass spectrometer (Q-TOF). The number of histone forms and their mass were found to differ not significantly from those obtained by ion trap mass spectrometer. Also the relative modifications abundance within the same histone type was found following the same trend as the two mass analysers. This method was then applied to the characterisation of changes in histone modification in HT29, never analysed by LC-MS before, treated with histone deacetylase inhibitors such as valproate and sodium butyrate, also used in preclinical trials as anticancer drugs. In particular, both the inhibitors produced a significant increase in H4 histone acetylated forms: 89% increase of the diacetyl dimethyl H4 form was observed with 1mM valproate supplementation, whereas 5 mM butyrate led to a 68% increase of the same form. Triacetyl monomethyl H4 (11,377 Da) and triacetyl dimethyl H4 (11,390 Da) were found only in cells treated with butyrate. Selective changes of H3 histone were detected with butyrate, in agreement with recently reported western blotting studies. Modifications in the H2A histone degree of acetylation were revealed by treatment of the cells with butyrate (H2A-1, H2A-2) and valproate (H2A-2). The results of the proposed methodology confirmed that inhibition of histone deacetylases caused histone hyperacetylation, responsible for decondensation and reorganization of interphase dynamic chromatin. This method resulted in selective and sensitive method to monitor variations in the acetylation and methylation state of histones after treatment of HT29 with inhibitors, and is therefore suitable for further application in new drug discovery for tumour therapy.


Subject(s)
Chromatography, High Pressure Liquid/methods , Colonic Neoplasms/metabolism , Histones/analysis , Spectrometry, Mass, Electrospray Ionization/methods , Acetylation/drug effects , Butyrates/pharmacology , HT29 Cells , Histone Deacetylase Inhibitors , Histone Deacetylases/metabolism , Histones/chemistry , Histones/metabolism , Humans , Reproducibility of Results , Valproic Acid/pharmacology
6.
Eur J Intern Med ; 33: 47-54, 2016 Sep.
Article in English | MEDLINE | ID: mdl-27289494

ABSTRACT

BACKGROUND: The optimal management of major bleeding associated with vitamin K antagonists remains unclear. OBJECTIVES: The aim of the study was to assess the determinants of outcome of vitamin K antagonists-associated major bleeding and the outcome of bleeding in relation with the therapeutic management. METHODS: Patients hospitalized for major bleeding while on vitamin K antagonists were included in a prospective, cohort study. Major bleeding was defined according to the criteria of the International Society of Thrombosis Haemostasis. The primary study outcome was death at 30days from major bleeding. RESULTS: 544 patients were included in this study, of which 282 with intracranial hemorrhage. Prothrombin complex concentrates were used in 51% and in 23% of patients with intracranial hemorrhage or non-intracranial major bleeding, respectively (p<0.001); fresh frozen plasma was used in 7% and in 17% of patients with intracranial hemorrhage or non-intracranial major bleeding (p<0.001). Death at 30days occurred in 100 patients (18%), 72 patients with intracranial hemorrhage and 28 patients with non-intracranial major bleeding. Age over 85years, low Glasgow Coma Scale score and shock were independent predictors of death at 30days. Invasive procedures were associated with decreased risk of death. CONCLUSIONS: Among the patients hospitalized for major bleeding while on vitamin K antagonists, the risk for death is substantial. The risk for death is associated with the clinical severity of major bleeding as assessed by the GCS score and by the presence of shock more than with the initial localization of major bleeding (ICH vs other sites).


Subject(s)
Blood Coagulation Factors/therapeutic use , Fibrinolytic Agents/adverse effects , Intracranial Hemorrhages/mortality , Intracranial Hemorrhages/therapy , Vitamin K/antagonists & inhibitors , Adult , Aged , Aged, 80 and over , Anticoagulants/adverse effects , Disease Management , Female , Glasgow Coma Scale , Humans , International Normalized Ratio , Intracranial Hemorrhages/chemically induced , Italy , Length of Stay , Male , Middle Aged , Plasma , Prognosis , Proportional Hazards Models , Prospective Studies , Warfarin/adverse effects
7.
Biochim Biophys Acta ; 862(2): 265-72, 1986 Nov 17.
Article in English | MEDLINE | ID: mdl-2430620

ABSTRACT

The evolution of the incorporation of cation transport channels into lysolecithin micelles by gramicidin A was followed by measuring the ns time-resolved fluorescence of the tryptophan residues. In all samples, the tryptophan fluorescence could be resolved into three exponentially decaying components. The three decay times ranged from 6 to 8 ns, 1.8 to 3 ns, and 0.3 to 0.8 ns, depending on the emission wavelength. The fractional fluorescence of each component changed with incubation time. The long lifetime component had a reduced contribution to the total fluorescence while the short decay time component increased. The fluorescence spectra could be resolved into three distinct fluorescent components having maxima at 340 nm, 330 nm and 323 nm after 90 min of incubation, and 335 nm, 325 nm and 320 nm after 24 h of incubation. These maxima were, respectively, associated with the long, medium and short decay components. The fluorescence decay behaviour was interpreted as representing three families of tryptophans, the short lifetime component being due to a stacking interaction between tryptophan residues. The variation with incubation time suggests a two-step process in the channel-lipid organization. The first is associated with the conformational change of the polypeptide as it takes up a left-handed helical head-to-head dimer structure in the lipid. The second step is proposed to involve changes originating from membrane assembly and intermolecular interactions between channels as they form hexameric clusters.


Subject(s)
Gramicidin , Ion Channels/physiology , Lysophosphatidylcholines , Tryptophan , Kinetics , Micelles , Models, Biological , Protein Conformation , Spectrometry, Fluorescence
8.
Biochim Biophys Acta ; 689(1): 113-20, 1982 Jul 14.
Article in English | MEDLINE | ID: mdl-6179540

ABSTRACT

Fluorescence studies are reported on gramicidin A' incorporated into lysophosphatidylcholine phospholipid structures. The shift in the emission maximum during incorporation and the quenching of fluorescence by I- and by acrylamide of the incorporated state obtained after prolonged heating are consistent with the presence of the channel state comprised of two single-stranded beta 6 -helices associated head-to-head (formyl end-to-formyl end). The quantum yield for the incorporated state, when gramicidin A' is within the lipid matrix, is very low and indicates the occurrence of intermolecular Trp-Trp interactions. Possible interactions between channels within the lipid matrix are discussed utilizing Trp-Trp contacts.


Subject(s)
Gramicidin , Ion Channels/metabolism , Lysophosphatidylcholines , Kinetics , Liposomes , Micelles , Models, Molecular , Protein Conformation , Quantum Theory , Spectrometry, Fluorescence
9.
Biochim Biophys Acta ; 732(1): 58-68, 1983 Jul 13.
Article in English | MEDLINE | ID: mdl-6191773

ABSTRACT

Heat derived gramicidin A'/L-alpha-lysophosphatidylcholine complexes were separated on a sucrose gradient to form two fractions: Fraction A which had an approximately constant Gramicidin A' to phospholipid ratio of 8 to 10 lipid molecules per Gramicidin A' molecule and Fraction B which had a larger but variable ratio. Fluorescence and circular dichroism studies confirmed Fraction A to be a lipid-incorporated channel state. Electron microscopic studies, using uranyl acetate negative staining, showed fraction A to be a membranous state with the formation of bilayer vesicles, that is, the interaction of peptide and phospholipid micelles causes the lipid to reorganize into a bilayer structure. Freeze-fracture replicas of the channel incorporated state demonstrated the presence of a supramolecular organization of particles exhibiting a tendency to form rows with a 50-60 A periodicity along the row and with 70-80 A distance between rows. An idealized working model for the incorporated state is presented.


Subject(s)
Gramicidin , Liposomes , Lysophosphatidylcholines , Biological Transport , Circular Dichroism , Microscopy, Electron , Models, Biological , Models, Molecular , Molecular Conformation , Spectrometry, Fluorescence , Spectrophotometry, Ultraviolet
10.
Mol Aspects Med ; 14(3): 209-15, 1993.
Article in English | MEDLINE | ID: mdl-8264335

ABSTRACT

Lipid peroxidation products have recently been proposed among the possible regulators of tumour cell growth. According to our current working hypothesis, the greatly diminished content of such products in tumour cells might relieve the inhibition of cell growth thus leading to uncontrolled proliferation. Hydroperoxy- and hydroxy derivatives of long chain fatty acids have been identified and determined in normal and tumour cells. Among these, hydroxystearic acid (HSA) has been shown to have a different cytostatic and cytotoxic effect when administered to murine lung carcinoma cells or to human colon tumour cells. It interferes with cell cycle kinetics, blocking the murine cells in G2-M and the human ones in G0-G1. The molecular target of HSA in both cell lines has been shown to be the cdc2 kinase complex. The results so far obtained in tumour as long as in normal highly proliferating cells do not exclude a potential future use of this class of compounds as selective anti tumour drugs.


Subject(s)
Cell Cycle/drug effects , Cell Division/drug effects , Stearic Acids/pharmacology , Animals , CDC2 Protein Kinase/metabolism , Cell Line , Colonic Neoplasms , DNA, Neoplasm/metabolism , Humans , Lipid Peroxidation , Lung Neoplasms , Mice , Tumor Cells, Cultured
11.
Free Radic Biol Med ; 4(6): 377-86, 1988.
Article in English | MEDLINE | ID: mdl-3290063

ABSTRACT

Several studies point to the existence of a disturbance in the metabolism of the reactive species of oxygen in cancer cells. Based on this evidence, and in particular on a characteristic behaviour of tumour membrane lipids, namely their growth-related resistance to oxy-radical-induced peroxidation, a sequence of events is outlined that could hypothetically drive the transformed cell to an uncontrolled proliferation. The proposed scheme is also conceived as a framework for further in vivo investigations of the complex biological phenomena of tumour cell growth and invasion in more integrated and kinetically controlled cellular systems.


Subject(s)
Lipid Peroxides/metabolism , Neoplasms, Experimental/metabolism , Tumor Cells, Cultured/metabolism , Animals , Free Radicals
12.
FEBS Lett ; 198(2): 301-6, 1986 Mar 31.
Article in English | MEDLINE | ID: mdl-3956738

ABSTRACT

Microsomal membranes from rat liver and from the fast-growing Morris hepatoma 3942A have been peroxidized to different extents and the order parameter of the membranes measured by fluorescence depolarization of the probe 1,6-diphenyl-1,3,5-hexatriene. The data have been analysed by applying a mathematical approach that takes into account simultaneously static and dynamic fluorescence parameters. It appears that tumour membranes are more ordered than the control and their order parameter does not increase with greater exposure to the action of O2 radicals in contrast to liver membranes. The fatty acid composition of the membrane lipids has been studied under different experimental conditions and correlated to the behaviour of the physical parameter.


Subject(s)
Lipid Peroxides/metabolism , Liver Neoplasms, Experimental/metabolism , Microsomes, Liver/metabolism , Oxygen/metabolism , Animals , Diphenylhexatriene , Fatty Acids/analysis , Fluorescence , Lipid Bilayers/metabolism , Male , Membrane Lipids/analysis , Rats , Temperature
13.
FEBS Lett ; 169(2): 169-73, 1984 Apr 24.
Article in English | MEDLINE | ID: mdl-6714424

ABSTRACT

Plasma membranes isolated from the fast-growing, maximal-deviation, Morris hepatoma 3924A exhibit remarkable changes in lipid composition, lipid peroxidation and to some extent in the physical state with respect to rat liver plasmalemmas. A correlation appears to exist between the lower phospholipid: protein ratio, higher cholesterol: phospholipid ratio, lower rate of lipid peroxidation and decrease in fluidity in tumor plasma membranes.


Subject(s)
Lipid Peroxides/metabolism , Liver Neoplasms, Experimental/ultrastructure , Liver/ultrastructure , Membrane Fluidity , Animals , Cell Line , Cell Membrane/metabolism , Cholesterol/metabolism , Mathematics , Membrane Lipids/metabolism , Phospholipids/metabolism , Rats , Temperature
14.
Biochem Pharmacol ; 33(1): 147-54, 1984 Jan 01.
Article in English | MEDLINE | ID: mdl-6200113

ABSTRACT

The results reported in this paper describe the effects produced by the antibiotic Coumermycin A1 (CA1) on survival and metabolism of chick embryo fibroblast cells (CEF), and give a clue to the understanding of its toxicity. The drug acts primarily at the level of DNA and RNA synthetic enzymes; no effect on DNA superstructure is detectable at doses at which cytotoxicity is pronounced. A spectroscopic approach produced evidence that CA1 binds to DNA, RNA, chromatin components such as histones and to a structurally unrelated protein such as bovine serum albumin. Furthermore, CA1 behaves like a pure non-competitive inhibitor of lactic dehydrogenase, a ubiquitous enzyme not involved in nucleic acid metabolism. The interaction of CA1 with a wide range of macromolecules playing different biological roles is certainly relevant to its activity and adds a new insight into the mechanism of action of this antibiotic. These observations are also discussed in the light of the alleged role of CA1 as a specific inhibitor of DNA topoisomerase in eukaryotic cells.


Subject(s)
DNA Replication/drug effects , Protein Biosynthesis/drug effects , RNA/biosynthesis , Aminocoumarins , Animals , Chick Embryo , Coumarins/toxicity , DNA Polymerase II/metabolism , Fibroblasts/drug effects , L-Lactate Dehydrogenase/metabolism , Mathematics , RNA Polymerase II/metabolism , Spectrophotometry
15.
Antiviral Res ; 6(1): 19-32, 1986 Jan.
Article in English | MEDLINE | ID: mdl-3008643

ABSTRACT

The mechanism of inhibition of the replication of herpes simplex virus type 1 (HSV-1) by coumermycin A1 (CA1), an inhibitor of bacterial DNA gyrase, has been investigated. Concentrations of antibiotic slightly higher than those needed for 50% inhibition of viral growth were able to inhibit viral DNA synthesis in infected cells. This effect was accompanied by a depressed synthesis of viral polypeptides. Protein synthesis was also inhibited in uninfected cells, especially after long exposure to the drug, but not in a cell-free system. In vitro assays of highly purified HSV-1 DNA polymerase in the presence of the drug, provided evidence that the enzyme was a target of CA1. The viral polymerase was in fact inhibited by the antibiotic to an extent comparable to that of viral DNA synthesis in intact cells. In contrast, DNA polymerase alpha, the enzyme involved in chromosomal DNA replication, was relatively insensitive to CA1. The drug was also shown to bind to protein and to viral and cellular DNA.


Subject(s)
DNA Replication/drug effects , Simplexvirus/drug effects , Virus Replication/drug effects , Aminocoumarins , Cell Line , Coumarins/metabolism , Coumarins/pharmacology , DNA Polymerase II/antagonists & inhibitors , DNA, Viral/biosynthesis , DNA-Directed DNA Polymerase , Exodeoxyribonucleases/antagonists & inhibitors , Nucleic Acid Synthesis Inhibitors , Peptide Biosynthesis , Topoisomerase II Inhibitors , Viral Proteins/biosynthesis
16.
Ann N Y Acad Sci ; 488: 468-80, 1986.
Article in English | MEDLINE | ID: mdl-3555261

ABSTRACT

Membranes isolated from tumor cells present profound alterations in their composition, structural organization, and functional properties. In this study we have reported some of these alterations in microsomal and plasma membranes of hepatomas with different growth rate and degree of differentiation. The chemical parameters studied were the phospholipid-to-protein, the cholesterol-to-protein, and the cholesterol-to-phospholipid ratios and the fatty acid composition of the phospholipids. The physical parameters were the molecular order (static) and the fluidity (dynamic), determined, respectively, as the order parameter [P2] and the correlation time tau R of the fluorescent probe 1,6-diphenyl-1,3,5-hexatriene (DPH). The functional property investigated was the ability of the membranes to undergo superoxide-induced lipid peroxidation, determined as byproduct (malondialdehyde and lipid hydroperoxides) formation and as changes in the fatty acid acyl residues. Changes in the physical state of the membrane, induced by oxy radicals, were also monitored during lipid peroxidation. A study of the antioxidant activity of the tumor cell, in terms of oxy radical enzymatic defenses (superoxide dismutase, glutathione peroxidase and catalase) was also performed. The main results obtained are the following: hepatoma membranes possess a lower phospholipid content and a lower degree of fatty acid unsaturation; on the other hand, the cholesterol-to-phospholipid ratio is increased; the physical state appears characterized by an increased rigidity (increased molecular order of the lipids and decreased fluidity); the membrane peroxidizability is markedly depressed and its order parameter, in contrast to liver membranes, does not increase with exposure to the action of O2- radicals; and the oxy radical enzymatic defense mechanisms are decreased. All these alterations increase with increasing growth rate and dedifferentiation of the tumor. Considering all of the data, we are inclined to think that tumor membranes are altered structurally and functionally in part as the result of an oxy radical-induced damage that takes place in vivo under conditions of increased oxygen toxicity.


Subject(s)
Liver Neoplasms, Experimental/metabolism , Oxygen/metabolism , Animals , Cell Membrane/metabolism , Free Radicals , Intracellular Membranes/metabolism , Lipid Peroxides/metabolism , Membrane Lipids/metabolism , Microsomes, Liver/metabolism , Rats
17.
Ann N Y Acad Sci ; 551: 47-57; discussion 57-8, 1988.
Article in English | MEDLINE | ID: mdl-3245678

ABSTRACT

Our studies on the biochemical composition and the structural organization of smooth and rough endoplasmic reticulum isolated from Morris hepatomas 9618A and 3924A confirm the results obtained employing the total microsomal fraction. We have definitely established the following facts: (1) Tumor subcellular organelles exhibit the very low degree of peroxidizability that has been shown to be related to the growth rate of the tumor. (2) Associated with such a low susceptibility to peroxidation are (a) changed lipid composition of cellular membranes, whose content in polyunsaturated fatty acid is markedly decreased, and (b) changed static and dynamic properties of the membrane. Previously it was also found that cellular oxy-radical scavenging enzymes are markedly reduced. From these data, it is possible to infer that tumor membranes are altered structurally and functionally in part as the result of an oxy-radical-induced damage that occurs in vivo under conditions of oxygen toxicity. This seems to be supported by recent findings that the spontaneous increase in growth rate of the originally very slow-growing Morris hepatoma 9618A results also in the loss of cytochrome P-450 (an important intramembraneous propagator of lipid peroxidation) as well as of C20:4 and C22:6. Studies performed by GLC and GC-MS on the fatty acid residues of phospholipids of rat liver microsomes show the presence of C20:3-OH and C18:1-OH, but no hydroxyl derivatives of low molecular weight aldehydes. The hydroxyl derivatives of arachidonic acid and linoleic acid are present in much smaller amounts in the microsomes isolated from H9618A and H3924A.


Subject(s)
Lipid Peroxidation , Liver Neoplasms, Experimental/metabolism , Animals , Chromatography, Gas , Endoplasmic Reticulum/metabolism , Gas Chromatography-Mass Spectrometry , Rats
18.
J Gerontol A Biol Sci Med Sci ; 55(12): M761-4, 2000 Dec.
Article in English | MEDLINE | ID: mdl-11129400

ABSTRACT

BACKGROUND: Arterial blood gas analysis (BGA) remains a first-step diagnostic approach in patients with suspected pulmonary embolism (PE). The aim of this study was to evaluate BGA parameters in elderly patients with suspected pulmonary embolism for diagnosis and 14-day prognosis. METHODS: We performed a retrospective cohort observational study of 6 years (1994-1999) in a 60-bed acute geriatric ward of University Hospital in Siena, Italy. Room air arterial oxygen partial pressure (pO2), arterial carbon dioxide partial pressure (pCO2), pH, arterial oxyhemoglobin saturation (SO2), and alveolar-arterial oxygen gradient [D(A-a)O2] were performed on hospital admission of 75 patients with confirmed PE (CPE) and were compared with data from 43 patients with unconfirmed PE (UCPE). The same parameters of 54 CPE surviving patients were compared with 21 CPE nonsurviving patients. RESULTS: Significantly lower PO2 and SO2, and higher DA-aO2 were found in CPE patients. Respiratory alkalosis was found in one third of the patients in both groups (no significant difference). In the CPE group, there was a significantly lower SO2 in nonsurviving patients, without significant differences for the other parameters. Metabolic acidosis was significantly more frequent in nonsurviving patients. CONCLUSION: More severe hypoxemia, oxyhemoglobin hyposaturation, and higher D(A-a)O2 are associated with the diagnosis of PE in elderly patients. Respiratory alkalosis is less frequent than in younger patients, and metabolic disorders are negative prognostic indicators.


Subject(s)
Carbon Dioxide/blood , Oxygen/metabolism , Pulmonary Alveoli/metabolism , Pulmonary Embolism/diagnosis , Pulmonary Embolism/metabolism , Aged , Aged, 80 and over , Arteries , Cohort Studies , Female , Humans , Male , Oxygen/blood , Oxyhemoglobins/analysis , Partial Pressure , Prognosis , Pulmonary Embolism/blood , Pulmonary Embolism/mortality , Retrospective Studies
19.
Biophys Chem ; 22(1-2): 11-6, 1985 Jun.
Article in English | MEDLINE | ID: mdl-17007778

ABSTRACT

At phosphate/dye (P/D) ratios greater than 30 the quantum yield of 4',6'-diamidine-2-phenylindole dihydrochloride (DAPI)-DNA and DAPI-poly(d(A-T)) complexes was found to be 0.62 and 0.66, respectively. Contrary to earlier reports a fluorescence enhancement of DAPI-poly(d(G-C)) complexes was observed with a quantum yield of 0.22. Time-resolved fluorescence measurements of complexes with a P/D ratio of 150:1 indicate that there were three fluorescent components in DAPI-DNA complexes with lifetimes of 3.86, 1.79 and 0.13 ns. In DAPI-poly(d(A-T)) complexes the lifetimes were 3.91, 1.20 and 0.11 ns. Also, three components with lifetimes of 3.98, 0.87 and 0.12 ns were found in DAPI-poly(d(G-C)) complexes. At low P/D ratios (< 5) another binding form of DAPI was observed which was assigned to the interaction of one or more molecules of DAPI with one previously bound to DNA. It is concluded that DAPI does not exhibit A-T binding specificity and that at high P/D ratios there are two types of binding having similar binding constants.

20.
Chem Phys Lipids ; 61(3): 255-63, 1992 May.
Article in English | MEDLINE | ID: mdl-1326418

ABSTRACT

A procedure for the preparation of N-[1-(2-naphthol)]-phosphatidylethanolamine (NAPH-PE) has been developed. The synthesis is based on the Schiff base formation between the NH2 of the phospholipid and the aldehyde moiety of 2-hydroxy-1-naphthaldehyde. Then selective reduction of the imine is used to obtain the stable secondary amine, NAPH-PE. Formation of the intermediate Schiff base and the final product is confirmed by 13C- and 1H-NMR. Similar to free 2-naphthol, the excited-state pKa (pKa*) of its phospholipid derivative appears to be significantly lower than the ground-state pKa. At pH 7.4, the excitation spectrum of NAPH-PE shows no deprotonated species in the ground-state, while the emission spectrum presents a significant contribution of this species. Thus the fluorescent phospholipid exhibits the typical behavior of excited-state proton-transfer probes. NAPH-PE is found to incorporate in dimyristoyllecithin (DML) vesicles. The emission spectrum of the probe inserted in the liposomes is affected by acetate used as a proton acceptor. These properties should also be manifest in other lipid bilayers (e.g., plasma membranes of cells) and used for excited-state proton transfer studies.


Subject(s)
Fluorescent Dyes/chemical synthesis , Phosphatidylethanolamines/chemical synthesis , Fluorescence , Hydrogen-Ion Concentration , Kinetics , Lipids/analysis , Magnetic Resonance Spectroscopy/methods , Membranes/chemistry , Naphthalenes/analysis , Optics and Photonics , Phosphatidylethanolamines/analysis , Protons , Spectrum Analysis/methods
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