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2.
J Matern Fetal Neonatal Med ; 26(4): 419-22, 2013 Mar.
Article in English | MEDLINE | ID: mdl-23039698

ABSTRACT

AIM: To compare the analgesic effect of three treatments to relieve the pain produced by intramuscular injections (IMI) in term newborns, and to assess sex-linked differences in their response to pain. MATERIAL AND METHODS: We studied 62 babies. Each baby received antibiotic IMIs for clinical aims. During each IMI, one of the following analgesic treatments was utilized: oral 33% glucose (OG), sensorial saturation (SS), or topic anesthetic cream (TAC). SS is a validated analgesic method, based on the combination of three stimulations (tactile, acoustic and gustative). During the IMI, pain level was assessed with the use of the DAN scale, a validated neonatal pain scale. All babies who received three distinct analgesic procedures for three distinct IMIs were enrolled. Mean pain scores of the three analgesic treatment groups were compared. We then compared mean pain scores of females vs males in the whole cohort and within each treatment group. RESULTS: The 95% Confidence Intervals of pain scores were 5.6-6.5 for TAC, 1.4-2.3 for OG and 0.6-1.2 for SS: when treated with TAC, babies' pain scores were significantly higher than with OG or SS (p <0.0001); when treated with OG, babies' pain scores were higher than SS (p = 0.002). Females' mean pain score was significantly higher than males' mean pain score: (95% CI: 2.9-4.1 vs 2.0-3.1; p = 0.01). OG and SS produced significantly higher mean DAN scores in females than in males. Also in the TAC group females' mean DAN scores were higher than males, though this last difference was not statistically significant. CONCLUSION: This is the first study to show the effectiveness of nonpharmacologic analgesia in relieving IMI pain. It is also the first study to clearly show that the sex differences in pain perception are present since birth.


Subject(s)
Analgesia/methods , Injections, Intramuscular/adverse effects , Pain/etiology , Sex Factors , Treatment Outcome , Administration, Oral , Administration, Topical , Analgesics/administration & dosage , Female , Glucose/administration & dosage , Humans , Infant, Newborn , Male , Pain Measurement/methods , Sensation
3.
Reprod Biomed Online ; 19(3): 300-13, 2009 Sep.
Article in English | MEDLINE | ID: mdl-19778474

ABSTRACT

Advances in proteomic technology have enabled contaminant proteins to be identified from complex protein mixtures. The purity of two purified urinary gonadotrophin products, human menopausal gonadotrophin (u-HMG) and human FSH (u-hFSH), was compared with a preparation of recombinant human FSH (r-hFSH). After separation by sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE), western blot analysis showed that the recombinant preparation contained only FSH, whereas the urine-derived preparations exhibited several non-FSH or LH-related bands. These urinary components were further investigated by a proteomic approach using two-dimensional SDS-PAGE followed by mass spectrometric identification. The proteomic approach detected a total of 23 non-gonadotrophin-related proteins, at variable levels in different batches of the urine-derived preparations. Of these, 16 co-purified proteins have not been previously reported to be present in urine-derived gonadotrophins. These results indicate that the process used to purify urinary gonadotrophins may not remove all non-gonadotrophin proteins. By using a comprehensive proteomic approach, it has been shown that the recombinant FSH preparation has greater purity than either of the urine-derived preparations.


Subject(s)
Drug Contamination , Menotropins/analysis , Drug Evaluation , Electrophoresis, Polyacrylamide Gel , Follicle Stimulating Hormone/analysis , Follicle Stimulating Hormone/standards , Humans , Menotropins/metabolism , Menotropins/standards , Menotropins/urine , Proteins/isolation & purification , Proteins/metabolism , Proteomics , Recombinant Proteins/analysis , Recombinant Proteins/standards , Urine/chemistry
4.
Minerva Ginecol ; 59(2): 125-9, 2007 Apr.
Article in English | MEDLINE | ID: mdl-17505454

ABSTRACT

AIM: Prenatal education courses (PEC) are a way of allaying anxiety in pregnancy. PEC consist of a series of five 1-hour lessons in the first and second trimesters of pregnancy. Conducted by nurses or midwives, the course syllabus includes the basics of fetal physiology and development, singing sessions, dance sessions, massage-through-the-womb sessions. Here we investigated whether they can enhance feto-maternal bonding. METHODS: We studied 77 pregnant women (mean age: 31.5+/-4.1 years), 36 of whom attended PEC. We used the Prenatal Attachment Inventory (PAI), a validated 21-item questionnaire, to score prenatal bonding and compared the scores of the two groups. Three months after delivery, we asked the mothers to fill in another questionnaire to assess infant and maternal well-being. RESULTS: The PEC group showed a higher PAI score than the control group (65.5+/-6.9 vs. 59.9+/-6.1; P<0.05). Babies born to the PEC group had a higher frequency of unexplained crying. CONCLUSION: PEC positively influenced prenatal attachment. More studies are needed to assess whether this may be useful for the development of the mother-infant relationship.


Subject(s)
Maternal-Fetal Relations/psychology , Object Attachment , Patient Education as Topic , Prenatal Care , Adult , Female , Humans , Pregnancy , Surveys and Questionnaires
5.
Reprod Biomed Online ; 13(2): 179-93, 2006 Aug.
Article in English | MEDLINE | ID: mdl-16895630

ABSTRACT

The revolutionary development of biotechnology-derived therapeutic proteins has provided the expected improvements in quality, purity and consistency, as demonstrated in recombinant human FSH (rhFSH). However, the development of urine-derived gonadotrophins has not always shown comparable improvements. More recently, highly purified urine-derived FSH (uFSH-HP) products have become widely available. The relative purity, level of urine-derived contaminants, and consistency of one such highly purified human uFSH (uhFSH) (urofollitropin) has been assessed and directly compared with rhFSH (follitropin alpha). It has been demonstrated that the highly purified urofollitropin contains variable levels of urine-derived contaminant proteins and demonstrates a variable level of FSH purity, FSH isoforms, and delivered dose. These variable factors may contribute to the control of ovarian stimulation. The relative purity, variable consistency and the presence of contaminants indicates that the urofollitropin is, at best, a partially purified uFSH that is not able to meet the quality attributes of follitropin alpha (rhFSH).


Subject(s)
Fertility Agents, Female/standards , Follicle Stimulating Hormone/standards , Glycoprotein Hormones, alpha Subunit/standards , Urofollitropin/standards , Blotting, Western , Chromatography, High Pressure Liquid , Densitometry , Drug Contamination , Electrophoresis, Polyacrylamide Gel , Female , Fertility Agents, Female/analysis , Follicle Stimulating Hormone/analysis , Glycoprotein Hormones, alpha Subunit/analysis , Humans , Immunohistochemistry , Protein Isoforms/analysis , Quality Control , Recombinant Proteins/standards , Urofollitropin/analysis , Urofollitropin/chemistry
6.
Panminerva Med ; 48(4): 231-9, 2006 Dec.
Article in English | MEDLINE | ID: mdl-17215795

ABSTRACT

Aspiration pneumonias occur more frequently than reported and, in many cases, the disease is not recognised. In hospitalised and institutionalised patients with predisposing diseases prompt diagnosis of this complication and correct preventive measures can drastically reduce the worsening of clinical conditions and the deaths due to aspiration pneumonia. Normal airway structure, effective defence mechanisms, and preventive measures are decisive in reducing aspiration episodes. An increased aspiration risk for food, fluids, medications, or secretions may lead to the development of pneumonia. Pneumonia is the most common respiratory complication in all stroke deaths and in mechanical ventilation patients. In addition, the increased incidence of aspiration pneumonia with aging may be a consequence of impairment of swallowing and the cough reflex. Dysphagia, compromised consciousness, invasive procedures, anaesthesia, insufficient oral care, sleep disorders, and vomiting are all risk factors. Aspiration pneumonia includes different characteristic syndromes based on the amount (massive, acute, chronic) and physical character of the aspirated material (acid, infected, lipoid), needing a different therapeutic approach. Chronic patients education and correct health care practices are the keys for preventing the events of aspiration. In patients at risk a clinical and instrumental assessment of dysphagia should be evaluated. Management includes the removal of etiologic factors (drugs, tubes, mobilisation, oral hygiene), supportive care, and in bacterial pneumonias a specific antibiotic therapy for community-acquired or nosocomial events.


Subject(s)
Pneumonia, Aspiration/physiopathology , Pneumonia, Aspiration/therapy , Primary Prevention , Humans , Pneumonia, Aspiration/diagnosis , Pneumonia, Aspiration/prevention & control , Prognosis
7.
Curr Med Res Opin ; 21(6): 899-905, 2005 Jun.
Article in English | MEDLINE | ID: mdl-15969890

ABSTRACT

OBJECTIVE: Pharmaceutical preparations of human menopausal gonadotrophin (hMG), urine-derived follicle-stimulating hormone (u-FSH) and highly purified u-FSH (u-FSH-HP) have been available since the early 1960s and the mid 1980s and 1990s, respectively. Another commercial preparation of u-FSH-HP, Folyrmon P, was launched in Japan in 1999. The aim of this study is to assess the purity of Folyrmon P and to compare it with Fertinorm-P, another commercial preparation of u-FSH-HP that has been available since 1993. METHODS: Folyrmon P and Fertinorm-P were assessed for total protein content, biological activity, immunological activity, specific activity, purity and levels of protein contamination. RESULTS: Folyrmon P, which is extracted from the urine of post-menopausal women, has a specific activity of between 4000 and 5000 IU/mg, while Fertinorm-P, which is also manufactured from the urine of post-menopausal women, has a specific activity of at least 10,000 IU/mg. It has been well documented that commercially available hMG and u-FSH preparations can contain a number of urine-derived protein contaminants. This also proves to be the case for Folyrmon P, in which contaminant proteins other than FSH were shown to be present. It was also demonstrated that both preparations, Folyrmon P and Fertinorm-P, contained high levels of oxidized FSH. CONCLUSIONS: The low specific activity and high level of contaminants in Folyrmon P indicate that this u-FSH is not highly purified. Overall, Fertinorm-P, with higher specific activity and lower levels of contaminant proteins, appears to be of higher quality compared with Folyrmon P.


Subject(s)
Follicle Stimulating Hormone/analysis , Pharmaceutical Preparations/analysis , Female , Follicle Stimulating Hormone/isolation & purification , Follicle Stimulating Hormone/urine , Humans , Postmenopause
8.
J Virol ; 74(11): 4939-48, 2000 Jun.
Article in English | MEDLINE | ID: mdl-10799567

ABSTRACT

The EBNA1 protein of Epstein-Barr virus (EBV) governs the replication and segregation of the viral episomes in latently infected cells and transactivates the expression of other EBV latency proteins through direct interactions with DNA sequences in the EBV latent origin of replication, oriP. To better understand how EBNA1 controls these processes, we have assessed the contribution of various EBNA1 sequences to its replication, segregation, and transactivation functions. Here we show that EBNA1 residues 325 to 376 are responsible for the transactivation activity of EBNA1. This region coincides with the DNA looping domain previously shown to mediate interactions at a distance between DNA-bound EBNA1 molecules. The same residues mediate DNA segregation but have no apparent role in DNA replication, indicating that the replication and transcription activation activities of EBNA1 are distinct. The acidic C-terminal tail of EBNA1 was not found to contribute to replication, transactivation, or segregation. We have also investigated the functional significance of two structural motifs within the DNA binding and dimerization domains of EBNA1, the proline loop and the WF motif. Although the amino acids in these motifs do not directly contact the DNA, both of these motifs were found to contribute to EBNA1 functions by increasing the DNA-binding ability of EBNA1. Mechanisms by which DNA binding is stimulated by these motifs are discussed.


Subject(s)
DNA, Viral/biosynthesis , Epstein-Barr Virus Nuclear Antigens/physiology , Herpesvirus 4, Human/genetics , Replication Origin , Amino Acid Sequence , Animals , Binding Sites , Epstein-Barr Virus Nuclear Antigens/chemistry , Epstein-Barr Virus Nuclear Antigens/genetics , Humans , Molecular Sequence Data , Proline/genetics , Proline/physiology
9.
EMBO Rep ; 1(2): 140-4, 2000 Aug.
Article in English | MEDLINE | ID: mdl-11265753

ABSTRACT

Latent Epstein-Barr virus (EBV) genomes are maintained in human cells as low copy number episomes that are thought to be partitioned by attachment to the cellular mitotic chromosomes through the viral EBNA1 protein. We have identified a human protein, EBP2, which interacts with the EBNA1 sequences that govern EBV partitioning. Here we show that, in mitosis, EBP2 localizes to the condensed cellular chromosomes producing a staining pattern that is indistinguishable from that of EBNA1. The localization of EBNA1 proteins with mutations in the EBP2 binding region was also examined. An EBNA1 mutant (delta325-376) disrupted for EBP2 binding and segregation function was nuclear but failed to attach to the cellular chromosomes in mitosis. Our results indicate that amino acids 325-376 mediate the binding of EBNA1 to mitotic chromosomes and strongly suggest that EBNA1 mediates EBV segregation by attaching to EBP2 on the cellular mitotic chromosomes.


Subject(s)
Carrier Proteins/metabolism , Chromosomes/metabolism , Epstein-Barr Virus Nuclear Antigens/genetics , Herpesvirus 4, Human/physiology , Nuclear Proteins/metabolism , Antineoplastic Agents, Phytogenic/pharmacology , B-Lymphocytes/physiology , Burkitt Lymphoma/genetics , Cell Line , Chromosomes/genetics , DNA/metabolism , Demecolcine/pharmacology , Epstein-Barr Virus Nuclear Antigens/metabolism , Humans , Microscopy, Fluorescence , Mitosis/drug effects , Mitosis/physiology , Protein Binding , Protein Structure, Tertiary , RNA-Binding Proteins , Tumor Cells, Cultured
10.
J Bioenerg Biomembr ; 32(2): 175-82, 2000 Apr.
Article in English | MEDLINE | ID: mdl-11768750

ABSTRACT

Hepatic iron toxicity because of iron overload seems to be mediated by lipid peroxidation of biological membranes and the associated organelle dysfunctions. However, the basic mechanisms underlying this process in vivo are still little understood. Gerbils were dosed with weekly injections of iron-dextran alone or in combination with sylibin, a well-known antioxidant, by gavage for 8 weeks. A strict correlation was found between lipid peroxidation and the level of desferrioxamine chelatable iron pool. A consequent derangement in the mitochondrial energy-transducing capability, resulting from a reduction in the respiratory chain enzyme activities, occurred. These irreversible oxidative anomalies brought about a dramatic drop in tissue ATP level. The mitochondrial oxidative derangement was associated with the development of fibrosis in the hepatic tissue. Silybin administration significantly reduced both functional anomalies and the fibrotic process by chelating desferrioxamine chelatable iron.


Subject(s)
Antioxidants/pharmacology , Iron Overload/prevention & control , Iron/adverse effects , Liver Cirrhosis/prevention & control , Mitochondria/drug effects , Oxidants/adverse effects , Silymarin/pharmacology , Adenosine Triphosphate/metabolism , Animals , Disease Models, Animal , Gerbillinae , Iron/metabolism , Iron Overload/metabolism , Iron-Dextran Complex/administration & dosage , Iron-Dextran Complex/metabolism , Lipid Peroxidation , Liver/metabolism , Liver Cirrhosis/chemically induced , Liver Cirrhosis/etiology , Liver Cirrhosis/metabolism , Male , Mitochondria/metabolism , Mitochondria/physiology , Oxidants/metabolism , Oxidative Stress
11.
J Neurol Sci ; 166(2): 131-40, 1999 Jul 01.
Article in English | MEDLINE | ID: mdl-10475107

ABSTRACT

Myopathy often complicates Zidovudine (AZT) treatment in patients with acquired immunodeficiency syndrome (AIDS). The pathogenesis of the myopathy is controversial, since clinical phenomena intrinsic to AIDS may interfere per se with the onset of the myopathy. In the present work we investigated the in vivo effect of AZT in an animal model species (rat) not susceptible to HIV infection. Histochemical and electron microscopic analyses demonstrated that, under the experimental conditions used, the in vivo treatment with AZT does not cause in skeletal muscle true dystrophic lesions, but rather mitochondrial alterations confined to the fast fibers. In the same animal models, the biochemical analysis confirmed that mitochondria are the target of AZT toxicity in muscles. The effects of AZT on mitochondria energy transducing mechanisms were investigated in isolated mitochondria both in vivo and in vitro. Membrane potential abnormalities, due to a partial impairment of the respiratory chain capability observed in muscle mitochondria from AZT-treated rats, closely resemble those of control mitochondria in the presence of externally added AZT. mtDNA deletion analysis by PCR amplification and Southern blot analysis did not show any relevant deletion, while mtDNA depletion analysis demonstrated a significant decrease in mtDNA in AZT-treated rats. The present findings show that AZT causes damage to mitochondria by two mechanisms: a short-term mechanism that affects directly the respiratory chain, and a long-term mechanism that alters the mitochondrial DNA thus impairing the mitochondrial protein synthesis. In addition, the ultrastructural observations indicate that the fiber types are differently affected upon AZT treatment, which poses a number of questions as to the pathogenesis of this myopathy.


Subject(s)
Anti-HIV Agents/adverse effects , DNA, Mitochondrial/drug effects , Mitochondrial Myopathies/chemically induced , Muscle Fibers, Skeletal/drug effects , Zidovudine/adverse effects , Animals , DNA, Mitochondrial/metabolism , Female , Mitochondrial Myopathies/metabolism , Mitochondrial Myopathies/pathology , Muscle Fibers, Skeletal/metabolism , Muscle Fibers, Skeletal/pathology , Oxidation-Reduction , Phosphorylation , Rats , Rats, Wistar
12.
J Virol ; 73(4): 2587-95, 1999 Apr.
Article in English | MEDLINE | ID: mdl-10074103

ABSTRACT

The replication and stable maintenance of latent Epstein-Barr virus (EBV) DNA episomes in human cells requires only one viral protein, Epstein-Barr nuclear antigen 1 (EBNA1). To gain insight into the mechanisms by which EBNA1 functions, we used a yeast two-hybrid screen to detect human proteins that interact with EBNA1. We describe here the isolation of a protein, EBP2 (EBNA1 binding protein 2), that specifically interacts with EBNA1. EBP2 was also shown to bind to DNA-bound EBNA1 in a one-hybrid system, and the EBP2-EBNA1 interaction was confirmed by coimmunoprecipitation from insect cells expressing these two proteins. EBP2 is a 35-kDa protein that is conserved in a variety of organisms and is predicted to form coiled-coil interactions. We have mapped the region of EBNA1 that binds EBP2 and generated internal deletion mutants of EBNA1 that are deficient in EBP2 interactions. Functional analyses of these EBNA1 mutants show that the ability to bind EBP2 correlates with the ability of EBNA1 to support the long-term maintenance in human cells of a plasmid containing the EBV origin, oriP. An EBNA1 mutant lacking amino acids 325 to 376 was defective for EBP2 binding and long-term oriP plasmid maintenance but supported the transient replication of oriP plasmids at wild-type levels. Thus, our results suggest that the EBNA1-EBP2 interaction is important for the stable segregation of EBV episomes during cell division but not for the replication of the episomes.


Subject(s)
Carrier Proteins/physiology , Epstein-Barr Virus Nuclear Antigens/physiology , Herpesvirus 4, Human/physiology , Nuclear Proteins , Amino Acid Sequence , Binding Sites/genetics , Cell Line , Humans , Molecular Sequence Data , Mutation , RNA-Binding Proteins , Saccharomyces cerevisiae Proteins , Sequence Alignment , Sequence Analysis , Virus Latency/physiology , Virus Replication/physiology
13.
Ital J Gastroenterol Hepatol ; 31(9): 861-7, 1999 Dec.
Article in English | MEDLINE | ID: mdl-10669994

ABSTRACT

BACKGROUND: Porphyria cutanea tarda and haemochromatosis are taken to be spontaneous human models of oxidative cellular damage, with an increased risk of fibrosis and cancer evolution. AIM: To define the relative pro-oxidant roles of porphyrin and iron, in their different molecular forms, and their effects on antioxidant biological systems. PATIENTS: A group of 17 patients with porphyria cutanea tarda and a group of 14 patients with primary and secondary haemochromatosis, were compared with 21 healthy controls. METHODS: Plasma retinol, tocopherol, alpha- and beta-carotene, ascorbic acid, glutathione, malonyldialdehyde and red blood cell free iron were determined using high performance liquid chromatography. RESULTS: Only a modest increase in iron stores was demonstrated in the porphyria cutanea tarda group; in the haemochromatosis patients ferritin levels were almost seven times higher. By contrast, there was a sharp and virtually identical increase in red blood cell free iron and malonyldialdehyde in both the patient groups. A significant reduction was observed in retinol, alpha-, beta-carotene and red blood cell glutathione levels being more marked in porphyria cutanea tarda than in haemochromatosis patients. CONCLUSIONS: The study confirms the strong pro-oxidant effects of porphyrins in vivo, through an induction of the free toxic iron form, even though the total iron pool is not greatly expanded. The additional free-iron and porphyrin oxidant effects are documented both in red blood cell and plasma in the porphyria cutanea tarda group. It confirmed that aging exerts a negative influence in terms of pro- and antioxidant balance in all cases, but particularly in the haemochromatosis group.


Subject(s)
Hemochromatosis/blood , Porphyria Cutanea Tarda/blood , Antioxidants , Female , Humans , Male , Middle Aged , Reactive Oxygen Species
14.
Hepatology ; 25(2): 385-90, 1997 Feb.
Article in English | MEDLINE | ID: mdl-9021951

ABSTRACT

Cocaine hepatotoxicity may be mediated by oxidative damage, possibly involving mitochondrial injury. The effect of an acute dose of cocaine in rats on the mitochondrial level of reduced glutathione, nicotinamide adenine dinucleotide (NADH) and nicotinamide adenine dinucleotide phosphate (NADPH), important determinants in cellular defense against oxidative stress, was investigated. Under these conditions, the extent of lipid peroxidation was assessed as thiobarbituric acid reactive substances formation and the energy transducing capability of the inner mitochondrial membrane was evaluated by membrane potential measurements. Female Wistar albino rats were given an acute 50 mg/kg intraperitoneal dose of cocaine and, 6 hours later, hepatic and mitochondrial biochemical analyses were made. Rats administered intraperitoneally, 7.5 hours before the sacrifice, a specific inhibitor of glutathione synthesis, L-buthionine-(S,R)-sulphoximine, either alone or in combination with cocaine, underwent in parallel the same determinations. Cocaine intoxication did not impair mitochondrial functions, although a significant increase of lipid peroxidation occurred. By contrast the combination of L-buthionine-(S,R)-sulphoximine with cocaine induced a severe derangement of mitochondrial functional efficiency, a large depletion of reduced glutathione, and a further enhancement of lipid peroxidation. The mitochondrial functional anomalies were largely restored by the use of cyclosporin A, ethyleneglycotetraacetic acid (EGTA) and glutathione methylmonoester. A nonspecific calcium dependent inner membrane permeabilty transition (pore opening) accounted for the partial loss of mitochondrial coupled functions at a period of cocaine intoxication when no cell damage occurred. The level of mitochondrial glutathione played a critical role in protecting inner membrane functional integrity against cocaine-induced oxidative stress.


Subject(s)
Cocaine/pharmacology , Glutathione/metabolism , Mitochondria, Liver/drug effects , Narcotics/pharmacology , Adenosine Diphosphate/metabolism , Animals , Calcium/metabolism , Female , Membrane Potentials/drug effects , Methionine/analogs & derivatives , Methionine/pharmacology , Mitochondria, Liver/physiology , Oxidation-Reduction , Rats , Rats, Wistar
15.
Exp Cell Res ; 222(1): 84-94, 1996 Jan 10.
Article in English | MEDLINE | ID: mdl-8549677

ABSTRACT

Isolated rat liver mitochondria were incubated under various metabolic conditions to determine their membrane potential (MMP) as measured continuously by a tetraphenylphosphonium (TPP+)-selective electrode. By flow cytometry, a parallel analysis of fluorescence emissions observing single mitochondria stained with the lipophilic cation 5,5',6,6'-tetrachloro-1,1'3,3'-tetraethylbenzimidazolcarbocyanine iodide (JC-1) revealed linear correlation between the median orange fluorescence (FL2) due to J-aggregate formations and MMP values measured by TPP+. No correlation was detected with the green fluorescence (FL1) emission. A significantly higher correlation appeared between the FL2/FL1 ratio and MMP values. Within the same mitochondrial population, cytofluorimetric analysis revealed the presence of various classes of organelles with different MMP, whose distribution was dependent on metabolic condition. The highest functional heterogeneity was found in deenergized mitochondria, while the highest homogeneity was observed during the first phase of the phosphorylative process. Thus, these data suggest that the cytofluorimetric use of JC-1 provides direct experimental evidence for the hypothesis of functional mitochondrial heterogeneity, at least with respect to their membrane potential.


Subject(s)
Flow Cytometry/methods , Mitochondria, Liver/physiology , Adenosine Diphosphate/pharmacology , Animals , Benzimidazoles , Carbocyanines , Carbonyl Cyanide p-Trifluoromethoxyphenylhydrazone , Female , Fluorescent Dyes , Indicators and Reagents , Ion-Selective Electrodes , Ionophores , Membrane Potentials , Onium Compounds , Organophosphorus Compounds , Phosphorylation/drug effects , Potassium Chloride , Rats , Rats, Wistar , Reproducibility of Results , Sensitivity and Specificity , Valinomycin
16.
Gastroenterology ; 109(6): 1941-9, 1995 Dec.
Article in English | MEDLINE | ID: mdl-7498660

ABSTRACT

BACKGROUND & AIMS: Hepatic iron toxicity may be mediated by free radical species and lipid peroxidation of biological membranes. The antioxidant property of silybin, a main constituent of natural flavonoids, was investigated in vivo during experimental iron overload. METHODS: Rats were fed a 2.5% carbonyl-iron diet and 100 mg.kg body wt-1.day-1 silybin for 4 months and were assayed for accumulation of hepatic lipid peroxidation by-products by immunocytochemistry, mitochondrial energy-dependent functions, and mitochondrial malondialdehyde content. RESULTS: Iron overload caused a dramatic accumulation of malondialdehyde-protein adducts into iron-filled periportal hepatocytes that was decreased appreciably by silybin treatment. The same beneficial effect of silybin was found on the iron-induced accumulation of malondialdehyde in mitochondria. As to the liver functional efficiency, mitochondrial energy wasting and tissue adenosine triphosphate depletion induced by iron overload were successfully counteracted by silybin. CONCLUSIONS: Oral administration of silybin protects against iron-induced hepatic toxicity in vivo. This effect seems to be caused by the prominent antioxidant activity of this compound.


Subject(s)
Antioxidants/pharmacology , Hemosiderosis/prevention & control , Silymarin/pharmacology , Adenosine Triphosphate/metabolism , Animals , Chemical and Drug Induced Liver Injury , Energy Metabolism , Female , Glutathione/metabolism , Immunohistochemistry , Iron/metabolism , Lipid Peroxidation/drug effects , Liver/drug effects , Liver/metabolism , Liver Diseases/metabolism , Liver Diseases/prevention & control , Male , Malondialdehyde/metabolism , Mitochondria, Liver/drug effects , Mitochondria, Liver/metabolism , Rats , Rats, Sprague-Dawley
17.
Biochem Biophys Res Commun ; 209(1): 53-9, 1995 Apr 06.
Article in English | MEDLINE | ID: mdl-7726863

ABSTRACT

The concentration of total iron in the hepatic tissue and mitochondria from rats fed a 2.5% carbonyl iron supplemented diet progressively increased up to 40 days, then reached nearly a steady-state. By contrast the level of free iron (desferrioxamine-chelatable) exhibited a transient but significant increase at 40 days of treatment, only in this period of treatment the induction of lipid peroxidation and the resulting mitochondrial abnormalities in calcium transport was observed too. The enhancement of the energy dissipating mitochondrial calcium cycling was found to be associated with a significant decrease of endogenous mitochondrial ATP content. As to the pathophysiological mechanism for hepatocellular injury in iron overload, these results indicated that the transit pool of free iron may play a critical role in initiating organelle dysfunctions, at least in this experimental model of iron overload.


Subject(s)
Diet , Iron/metabolism , Mitochondria, Liver/metabolism , Animals , Egtazic Acid , Female , Intracellular Membranes/metabolism , Iron/administration & dosage , Lipid Peroxidation , Liver/metabolism , Liver/physiopathology , Malondialdehyde/metabolism , Membrane Potentials , Rats , Rats, Wistar
18.
Biochim Biophys Acta ; 1188(1-2): 46-52, 1994 Nov 01.
Article in English | MEDLINE | ID: mdl-7947904

ABSTRACT

Severe iron deficiency was induced in rats by rearing nursing dams and their offspring on a diet comprising all the requisite nutrients and trace metals except iron. The iron deficient 5-week-old rats exhibited a severe anemia and a drastic decrease in iron content of the hepatic tissue and of the mitochondrial fraction. Cytochromes c + c1 and b were moderately but significantly reduced. A large increase in liver concentration was observed in iron-deficient animals; whereas there was no modification in total lipid, cholesterol, phospholipid and fatty acid composition of the mitochondrial membrane. Mitochondria from iron-deficient rats presented a partial uncoupling of the oxidative phosphorylation process. This functional derangement was completely reversed by the presence of either bovine serum albumin or L-carnitine plus ATP. This behaviour suggested that endogenous long-chain fatty acids could be primarily involved in the onset of mitochondrial dysfunction. The hepatic energy state of the liver appeared dramatically decreased under the pathological condition of severe iron-deficiency anemia. The possibility of a direct link between the partial loss of coupled functions observed in isolated mitochondria and the heavy energy deficit detected in the liver is discussed.


Subject(s)
Iron Deficiencies , Liver/metabolism , Animals , Cholesterol/metabolism , Diet , Energy Metabolism , Female , Intracellular Membranes/metabolism , Magnetic Resonance Spectroscopy , Membrane Potentials , Mitochondria, Liver/metabolism , Phospholipids/metabolism , Rats , Rats, Sprague-Dawley
19.
Biochim Biophys Acta ; 1188(1-2): 53-7, 1994 Nov 01.
Article in English | MEDLINE | ID: mdl-7947905

ABSTRACT

Severe iron deficiency in rats was found to be associated with abnormal lipid accumulation in the liver and impairment of the oxidative metabolism in the hepatic tissue. Iron therapy, consisting in oral administration to iron-deficient 4-week-old rats of iron succinyl-albumin complex, at a daily dose of 10 mg/kg body weight, over a period of 7 days, almost completely corrected these functional anomalies. This treatment fully reverted severe anemia associated with iron deficiency. The level of iron in the hepatic tissue and in the mitochondrial fraction also increased largely. By contrast, no significant improvement in the lowered level of cytochromes occurred. Iron supplements significantly decreased the abnormal level of liver total lipids and serum triglycerides. Concomitantly, iron repletion fully reverted the partial loss of coupled function in isolated mitochondria and the energy state perturbation of the liver. A close relationship among abnormal lipid accumulation, impairment of mitochondrial oxidative phosphorylation and energy derangement in the hepatic cell in this experimental model of severe dietary iron deficiency anemia appears to be likely.


Subject(s)
Iron Deficiencies , Liver/metabolism , Milk Proteins/therapeutic use , Organometallic Compounds/therapeutic use , Anemia, Iron-Deficiency/drug therapy , Animals , Cell Survival , Diet , Energy Metabolism , Female , Hemoglobins/analysis , Iron/analysis , Iron/therapeutic use , Lipids/analysis , Liver/chemistry , Metalloproteins , Mitochondria, Liver/metabolism , Rats , Rats, Wistar , Succinates , Triglycerides/blood
20.
Biosci Rep ; 14(1): 33-42, 1994 Feb.
Article in English | MEDLINE | ID: mdl-8032007

ABSTRACT

Reports of the antiviral activity of aliphatic alcohols led us to investigate the effects of aliphatic alcohols, from 10 to 20 carbons in length, on the phase transition behaviour of model phospholipids and on the fusion of influenza to liposomes. Contrary to the effects of many other antiviral agents, we find that alcohols are potent promoters of the inverted hexagonal phase. However, we also find that aliphatic alcohols have little effect on influenza fusion to liposomes. Eicosanol is the only aliphatic alcohol tested which substantially increases in fusion of influenza virus. We also find that long chain alcohols display multi-component bilayer to hexagonal phase transitions at higher mole fractions. This suggests that eicosanol may be facilitating fusion by creating defects between alcohol-rich and alcohol-poor regions of the lipid bilayer.


Subject(s)
Alcohols/pharmacology , Liposomes , Membrane Fusion/drug effects , Orthomyxoviridae/drug effects
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