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1.
Eur Rev Med Pharmacol Sci ; 28(15): 4060-4066, 2024 Aug.
Article in English | MEDLINE | ID: mdl-39194197

ABSTRACT

OBJECTIVE: Pulmonary hypertension in the newborn (PPHN) is a significant clinical condition characterized by elevated pulmonary artery pressures, leading to serious health consequences. Magnesium sulfate, known for its vasodilatory properties, has been studied for its potential benefits in managing PPHN. This systematic review evaluates the efficacy and safety of magnesium sulfate in neonates with PPHN. MATERIALS AND METHODS: A systematic literature search was conducted on PubMed and Scopus up to March 10, 2024. Studies were included based on predefined Population, Intervention, Comparison, Outcome, Study (PICOS) criteria focusing on pediatric patients with PPHN treated with magnesium sulfate, compared against placebo or other pharmacological interventions. Outcomes of interest included resolution of PPHN, improved oxygenation, and decreased oxygenation index. RESULTS: From a total of 1,233 articles screened, four studies met the inclusion criteria, including three randomized controlled trials and one multicentric retrospective study. The comparisons included nebulized magnesium sulfate, oral sildenafil, and inhaled nitric oxide. The outcomes varied, with none reported consistently across more than two studies, making a meta-analysis unfeasible. Results indicated a potential benefit of magnesium sulfate in improving pulmonary pressures and oxygenation, but the evidence was insufficient to establish definitive conclusions due to the heterogeneity and a limited number of studies. CONCLUSIONS: The limited data suggest that, while magnesium sulfate may have a role in the management of PPHN, it should not replace established therapies. Further research is needed to better define its efficacy and safety profile.


Subject(s)
Hypertension, Pulmonary , Magnesium Sulfate , Humans , Magnesium Sulfate/administration & dosage , Magnesium Sulfate/therapeutic use , Infant, Newborn , Hypertension, Pulmonary/drug therapy , Vasodilator Agents/administration & dosage , Vasodilator Agents/therapeutic use , Vasodilator Agents/adverse effects , Administration, Intravenous , Persistent Fetal Circulation Syndrome/drug therapy , Nitric Oxide/administration & dosage
2.
Antioxidants (Basel) ; 13(7)2024 Jul 14.
Article in English | MEDLINE | ID: mdl-39061910

ABSTRACT

Hearing loss is a prevalent condition affecting millions of people worldwide. Hearing loss has been linked to oxidative stress as a major factor in its onset and progression. The goal of this thorough analysis is to investigate the connection between oxidative stress and hearing loss, with an emphasis on the underlying mechanisms and possible treatments. The review addressed the many forms of hearing loss, the role of reactive oxygen species (ROS) in causing damage to the cochlea, and the auditory system's antioxidant defensive mechanisms. The review also goes over the available data that support the use of antioxidants and other methods to lessen hearing loss brought on by oxidative stress. We found that oxidative stress is implicated in multiple types of hearing loss, including age-related, noise-induced, and ototoxic hearing impairment. The cochlea's unique anatomical and physiological characteristics, such as high metabolic activity and limited blood supply, make it particularly susceptible to oxidative damage. Antioxidant therapies have shown promising results in both animal models and clinical studies for preventing and mitigating hearing loss. Emerging therapeutic approaches, including targeted drug delivery systems and gene therapy, offer new possibilities for addressing oxidative stress in the auditory system. The significance of this review lies in its comprehensive analysis of the intricate relationship between oxidative stress and hearing loss. By synthesizing current knowledge and identifying gaps in understanding, this review provides valuable insights for both researchers and clinicians. It highlights the potential of antioxidant-based interventions and emphasizes the need for further research into personalized treatment strategies. Our findings on oxidative stress mechanisms may also affect clinical practice and future research directions. This review serves as a foundation for developing novel therapeutic approaches and may inform evidence-based strategies for the prevention and treatment of hearing loss, ultimately contributing to improved quality of life for millions affected by this condition worldwide.

4.
Mol Imaging Biol ; 21(1): 19-24, 2019 02.
Article in English | MEDLINE | ID: mdl-29845428

ABSTRACT

PURPOSE: Computed tomography (CT) images enable capturing specific manifestations of tuberculosis (TB) that are undetectable using common diagnostic tests, which suffer from limited specificity. In this study, we aimed to automatically quantify the burden of Mycobacterium tuberculosis (Mtb) using biomarkers extracted from x-ray CT images. PROCEDURES: Nine macaques were aerosol-infected with Mtb and treated with various antibiotic cocktails. Chest CT scans were acquired in all animals at specific times independently of disease progression. First, a fully automatic segmentation of the healthy lungs from the acquired chest CT volumes was performed and air-like structures were extracted. Next, unsegmented pulmonary regions corresponding to damaged parenchymal tissue and TB lesions were included. CT biomarkers were extracted by classification of the probability distribution of the intensity of the segmented images into three tissue types: (1) Healthy tissue, parenchyma free from infection; (2) soft diseased tissue, and (3) hard diseased tissue. The probability distribution of tissue intensities was assumed to follow a Gaussian mixture model. The thresholds identifying each region were automatically computed using an expectation-maximization algorithm. RESULTS: The estimated longitudinal course of TB infection shows that subjects that have followed the same antibiotic treatment present a similar response (relative change in the diseased volume) with respect to baseline. More interestingly, the correlation between the diseased volume (soft tissue + hard tissue), which was manually delineated by an expert, and the automatically extracted volume with the proposed method was very strong (R2 ≈ 0.8). CONCLUSIONS: We present a methodology that is suitable for automatic extraction of a radiological biomarker from CT images for TB disease burden. The method could be used to describe the longitudinal evolution of Mtb infection in a clinical trial devoted to the design of new drugs.


Subject(s)
Bacterial Load/methods , Biomarkers/analysis , Tomography, X-Ray Computed/methods , Tuberculosis, Pulmonary/diagnosis , Algorithms , Animals , Disease Progression , Imaging, Three-Dimensional , Longitudinal Studies , Lung/diagnostic imaging , Lung/microbiology , Lung/pathology , Macaca fascicularis , Male , Mycobacterium tuberculosis/cytology , Sensitivity and Specificity , Severity of Illness Index , Tuberculosis, Pulmonary/microbiology
5.
Mucosal Immunol ; 11(2): 462-473, 2018 03.
Article in English | MEDLINE | ID: mdl-28745326

ABSTRACT

Protection against Mycobacterium tuberculosis (Mtb) infection requires CD4 T cells to migrate into the lung and interact with infected macrophages. In mice, less-differentiated CXCR3+ CD4 T cells migrate into the lung and suppress growth of Mtb, whereas CX3CR1+ terminally differentiated Th1 cells accumulate in the blood vasculature and do not control pulmonary infection. Here we examine CD4 T-cell differentiation and lung homing during primary Mtb infection of rhesus macaques. Mtb-specific CD4 T cells simultaneously appeared in the airways and blood ∼21-28 days post exposure, indicating that recently primed effectors are quickly recruited into the lungs after entering circulation. Mtb-specific CD4 T cells in granulomas display a tissue-parenchymal CXCR3+CX3CR1-PD-1hiCTLA-4+ phenotype. However, most granuloma CD4 T cells are found within the outer lymphocyte cuff and few localize to the myeloid cell core containing the bacilli. Using the intravascular stain approach, we find essentially all Mtb-specific CD4 T cells in granulomas have extravasated across the vascular endothelium into the parenchyma. Therefore, it is unlikely to be that lung-homing defects introduced by terminal differentiation limit the migration of CD4 T cells into granulomas following primary Mtb infection of macaques. However, intralesional positioning defects within the granuloma may pose a major barrier to T-cell-mediated immunity during tuberculosis.


Subject(s)
CD4-Positive T-Lymphocytes/immunology , Granuloma, Respiratory Tract/immunology , Lung/immunology , Macaca mulatta/immunology , Macrophages, Alveolar/immunology , Mycobacterium tuberculosis/physiology , Tuberculosis/immunology , Animals , Antigens, Bacterial/immunology , Cell Communication , Cell Movement , Cells, Cultured , Humans , Immune Evasion , Immunity, Cellular , Lung/microbiology , Macaca mulatta/microbiology , Mice , Mice, Inbred C57BL , Receptors, CXCR3/metabolism
6.
Int J Tuberc Lung Dis ; 21(10): 1145-1149, 2017 10 01.
Article in English | MEDLINE | ID: mdl-28911359

ABSTRACT

BACKGROUND: Interferon-gamma (IFN-γ) release assays (IGRAs) are used to diagnose tuberculosis (TB) but not to measure treatment response. OBJECTIVE: To measure IFN-γ response to active anti-tuberculosis treatment. DESIGN: Patients from the Henan Provincial Chest Hospital, Henan, China, with TB symptoms and/or signs were enrolled into this prospective, observational cohort study and followed for 6 months of treatment, with blood and sputum samples collected at 0, 2, 4, 6, 8, 16 and 24 weeks. The QuantiFERON® TB-Gold assay was run on collected blood samples. Participants received a follow-up telephone call at 24 months to determine relapse status. RESULTS: Of the 152 TB patients enrolled, 135 were eligible for this analysis: 118 pulmonary (PTB) and 17 extra-pulmonary TB (EPTB) patients. IFN-γ levels declined significantly over time among all patients (P = 0.002), with this decline driven by PTB patients (P = 0.001), largely during the initial 8 weeks of treatment (P = 0.019). IFN-γ levels did not change among EPTB patients over time or against baseline culture or drug resistance status. CONCLUSION: After 6 months of effective anti-tuberculosis treatment, IFN-γ levels decreased significantly in PTB patients, largely over the initial 8 weeks of treatment. IFN-γ concentrations may offer some value for monitoring anti-tuberculosis treatment response among PTB patients.


Subject(s)
Antitubercular Agents/therapeutic use , Interferon-gamma Release Tests/methods , Tuberculosis, Pulmonary/drug therapy , Tuberculosis/drug therapy , Adult , Case-Control Studies , Cohort Studies , Female , Follow-Up Studies , Humans , Interferon-gamma/blood , Male , Prospective Studies , Time Factors , Treatment Outcome , Tuberculosis/diagnosis , Tuberculosis, Pulmonary/diagnosis
7.
Bioorg Med Chem ; 23(17): 5816-28, 2015 Sep 01.
Article in English | MEDLINE | ID: mdl-26190458

ABSTRACT

The anti-inflammatory and antiproliferative activities of 4ß-cinnamoyloxy,1ß,3α-dihydroxyeudesm-7,8-ene (1) and of three derivatives, namely diacetate (2), hydrogenate (3) and diacetate hydrogenate (4) were evaluated. All derivatives exert an anti-inflammatory effect significantly lower than that exerted by 1. Otherwise, both the lead compound and 2-4 showed a comparable antiproliferative activity on human tumor cell lines. The investigation of the mechanism of action accountable for cytotoxicity highlighted the capacity to impair mitochondrial functions through two different pathways, depending on chemical structure. In particular, the lead compound 1 and derivative 3 are able to induce mitochondrial permeability transition, while derivatives 2 and 4 inhibit Complex II in the respiratory chain.


Subject(s)
Anti-Inflammatory Agents/pharmacology , Mitochondria/metabolism , Verbesina/chemistry , Humans , Molecular Structure
8.
Int J Tuberc Lung Dis ; 16(7): 961-6, 2012 Jul.
Article in English | MEDLINE | ID: mdl-22584241

ABSTRACT

OBJECTIVE: To determine the frequency of and risk factors for major adverse drug reactions (MADRs) associated with anti-tuberculosis treatment at a tuberculosis (TB) referral hospital in the Republic of Korea. METHODS: Data from an ongoing natural history cohort study were analyzed for permanent regimen changes due to adverse drug reactions and confirmed by chart review. RESULTS: Among 655 subjects, there were 132 MADRs in 112 (17%) subjects. The most common MADRs were gastrointestinal (n = 53), musculoskeletal (n = 22), psychiatric (n = 10), visual (n = 9) and peripheral neuropathic (n = 8). MADRs were more frequent in subjects being treated with second-line regimens (16%) compared to first-line regimens (2.5%). Drugs frequently associated with MADRs were amikacin (3/10, 30%), linezolid (8/29, 28%), para-aminosalicylic acid (47/192, 24%), pyrazinamide (31/528, 5.8%), macrolides (2/44, 4.5%) and cycloserine (12/272, 4.4%). Fluoroquinolones accounted for a single MADR (1/377, 0.003%), despite widespread usage. In multivariate analysis, infection with multi- or extensively drug-resistant disease and previous history of anti-tuberculosis treatment were risk factors for MADR, with adjusted hazard ratios of respectively 2.2 (P = 0.02) and 1.6 (P = 0.04). CONCLUSION: MADRs are common during anti-tuberculosis chemotherapy in this population, occurring in more than one in six subjects. New and less toxic agents to treat drug-resistant TB are urgently needed.


Subject(s)
Antitubercular Agents/adverse effects , Tuberculosis, Multidrug-Resistant/drug therapy , Tuberculosis/drug therapy , Adult , Aged , Antitubercular Agents/therapeutic use , Drug-Related Side Effects and Adverse Reactions , Female , Humans , Male , Middle Aged , Multivariate Analysis , Republic of Korea , Risk Factors , Treatment Outcome , Young Adult
9.
J Chemother ; 21(3): 302-10, 2009 Jun.
Article in English | MEDLINE | ID: mdl-19567351

ABSTRACT

This prospective study evaluated the frequency and severity of respiratory symptoms during the second respiratory syncytial virus (RSV) season in an italian cohort of preterm infants (< or = 35 weeks) who had received palivizumab prophylaxis in their first year of life (October 2004-April 2005) and who had not previously been hospitalized for RSV-induced lower respiratory tract infection (LRTI). infants were evaluated at enrolment (May-September 2005), in October/November 2005 and in April 2006. The occurrence of any respiratory episode, the rate of hospitalization for respiratory-related LRTI, total length of stay in hospital, physician-documented recurrent wheezing (>or = 3 physician-documented episodes of wheezing) and use of airway medication/antibiotics were recorded during follow-up. All infants had prior palivizumab prophylaxis during their first RSV season. In the total evaluable population (n=260), 32.3% of infants experienced at least one respiratory episode, 3.8% required short hospitalization because of LRTI, 8.5% had physician-documented recurrent wheezing, and 48.8% required airway medications/antibiotics during follow-up. in this study the rate of airway morbidity, hospitalization and physician-documented recurrent wheezing during the second RSV season was low among preterm infants who had received prior palivizumab prophylaxis.


Subject(s)
Antibodies, Monoclonal/therapeutic use , Hospitalization/statistics & numerical data , Respiratory Syncytial Virus Infections/prevention & control , Respiratory Tract Diseases/epidemiology , Antibodies, Monoclonal, Humanized , Cohort Studies , Female , Follow-Up Studies , Humans , Infant , Infant, Newborn , Infant, Premature , Male , Palivizumab , Prospective Studies , Respiratory Sounds , Respiratory Tract Infections/epidemiology
10.
Bioorg Med Chem ; 17(1): 326-36, 2009 Jan 01.
Article in English | MEDLINE | ID: mdl-19022678

ABSTRACT

This study reports the synthesis of a number of 1- and 2-phenyl derivatives of the 1,4-dihydrobenzothiopyrano[4,3-c]pyrazole nucleus, which were obtained by the reaction of the versatile 7-substituted 2,3-dihydro-3-hydroxymethylene-4H-1-benzothiopyran-4-ones with hydrazine and substituted phenylhydrazines. The antiproliferative activity of the synthesized compounds was evaluated by an in vitro assay on human tumor cell lines (HL-60 and HeLa) and showed a significant capacity of the 7-methoxy-substituted benzothiopyrano[4,3-c]pyrazoles 3b-d, carrying the pendant phenyl group in the 1-position, to inhibit cell growth. Investigation of the mechanism of action indicated the induction of the mitochondrial permeability transition (MPT) as the molecular event responsible for the inhibition of cell growth. This phenomenon is related to the ability of the test compounds to cause a rapid Ca2+-dependent and cyclosporin A-sensitive collapse of the transmembrane potential (DeltaPsi) and matrix swelling. All this leads to the release of caspase activators, such as cytochrome c (cyt c) and apoptosis-inducing factor (AIF), which trigger the pro-apoptotic pathway leading to DNA fragmentation.


Subject(s)
Antineoplastic Agents/chemical synthesis , Apoptosis/drug effects , Pyrazoles/chemical synthesis , Antineoplastic Agents/pharmacology , Apoptosis Regulatory Proteins , Benzene Derivatives , Cell Line, Tumor , Cell Proliferation/drug effects , Humans , Membrane Potentials , Mitochondrial Membranes , Permeability , Pyrazoles/pharmacology
11.
Eur J Med Chem ; 43(2): 429-34, 2008 Feb.
Article in English | MEDLINE | ID: mdl-17573162

ABSTRACT

The newly synthesized 1-[4-(3H-pyrrolo[3,2-f]quinolin-9-ylamino)-phenyl]-ethanone hydrochloride showed high antiproliferative activity by mixed mechanisms of action. The compound acts by forming an intercalative complex with DNA and inhibiting DNA topoisomerase II (topo II) and by blocking the cell cycle in G(2)/M phase. Probable cell death by apoptosis is also suggested by flow cytometry analysis.


Subject(s)
Antineoplastic Agents/chemistry , Antineoplastic Agents/pharmacology , Quinolines/chemistry , Quinolines/pharmacology , Apoptosis/drug effects , Cell Cycle/drug effects , Cell Line, Tumor , Enzyme Inhibitors/chemistry , Enzyme Inhibitors/pharmacology , Flow Cytometry , Humans , Mass Spectrometry , Spectrophotometry, Ultraviolet , Topoisomerase II Inhibitors
12.
Bioorg Med Chem ; 12(4): 771-7, 2004 Feb 15.
Article in English | MEDLINE | ID: mdl-14759737

ABSTRACT

Two novel DNA-direct alkylating agents, consisting of aniline mustard linked to an angular 3H-pyrrolo[3,2-f]quinoline nucleus, were synthetized and assayed for their in vitro antiproliferative activity. Simple convergent synthesis, consisting of separate preparation of 9-chloro-3H-pyrrolo[3,2-f]quinoline and p-amino-aniline derivatives, and following their linkage by substitution reactions 8a, b and 10, yielded the corresponding diol derivatives 7b and 9. Biological properties were evaluated with respect to cell growth inhibition, ability to form cross-links with DNA, and capacity to give rise to a molecular complex with the macromolecule for 7b, 8b, 9 and 10.


Subject(s)
Alkylating Agents/chemical synthesis , Alkylating Agents/pharmacology , DNA/metabolism , Pyrroles/chemistry , Pyrroles/pharmacology , Quinolines/chemistry , Quinolines/pharmacology , Alkylating Agents/chemistry , Alkylation/drug effects , Animals , Cell Division/drug effects , Cell Line , Circular Dichroism , DNA/chemistry , Humans , Inhibitory Concentration 50 , Molecular Structure , Pyrroles/chemical synthesis , Quinolines/chemical synthesis , Salmon , Substrate Specificity
14.
Curr Med Chem ; 8(12): 1405-18, 2001 Oct.
Article in English | MEDLINE | ID: mdl-11562274

ABSTRACT

The development of therapies which are selective for tumor tissues is one of the most important goals in anticancer research. Within this framework photochemotherapy can be considered a very promising approach. Its therapeutic effectiveness depends on two connected factors: drug and light. The drug (photosensitizer) is able to exert an antiproliferative effect only after interaction with suitable light. Both the photosensitizing drug and light alone are ineffective at doses used for these treatments. Nowadays, photochemotherapy is used in the treatment of cutaneous T-cell lymphoma and cavitary tumors. In the first case the photosensitizer is a psoralen derivative (P) and long-wavelength ultraviolet radiation (UVA) is used (PUVA therapy). In the second case, the treatment with porphyrins, porphyrin-based and non porphyrin-based photosensitizers is followed by irradiation with 600-1000 nm light (photodynamic therapy, PDT). This review is concerned with PUVA and PDT treatments of cancer. The molecular mechanisms considered accountable for the photochemotherapeutic effects are discussed, the development of new chemical structures aimed at improving the effectiveness and/or overcoming some undesired side effects will also be reported. Moreover, some clinical applications will be described.


Subject(s)
Neoplasms/drug therapy , Photochemotherapy , Photosensitizing Agents/therapeutic use , Humans
15.
Farmaco ; 56(3): 159-67, 2001 Mar.
Article in English | MEDLINE | ID: mdl-11409322

ABSTRACT

The synthesis of benzimidazoquinazoline derivatives bearing different alkylamino side chains is reported. All new compounds tested by means of an in vitro assay exhibit antiproliferative activity toward human tumor cell lines. The cytotoxic effect depends on the type of side chain inserted in the planar nucleus and in some cases it is comparable to that of the well-known drug ellipticine. In order to understand the mechanism of action of these compounds, the interaction with DNA has been investigated. Linear flow dichroism measurements allowed us to verify the formation of a molecular complex with DNA and the corresponding geometry of interaction. Intrinsic binding constants have also been evaluated by performing fluorimetric titrations.


Subject(s)
Antineoplastic Agents/chemical synthesis , Antineoplastic Agents/pharmacology , Benzimidazoles/chemical synthesis , Benzimidazoles/pharmacology , DNA, Neoplasm/drug effects , Quinazolines/chemical synthesis , Quinazolines/pharmacology , Circular Dichroism , DNA/chemistry , Drug Screening Assays, Antitumor , HL-60 Cells , Humans , Kinetics , Magnetic Resonance Spectroscopy , Spectrometry, Fluorescence , Spectrophotometry, Ultraviolet , Tumor Cells, Cultured
16.
J Photochem Photobiol B ; 56(2-3): 132-8, 2000 Jul.
Article in English | MEDLINE | ID: mdl-11079473

ABSTRACT

This paper reports the photobiological properties of two new thienocoumarins, 4,6,9-trimethyl-2H-thieno[3,2-g]-1-benzopyran-2-one (compound I) and the 6,9-dimethyl-4-methoxymethyl-2H-thieno[3,2-g]-1-benzopyran-2-one (compound II). Cell growth inhibition studies have revealed significant antiproliferative potency on human tumor cell lines. The photoaddition process of these tritium-labeled derivatives was investigated using various nucleic acid structures (calf thymus DNA, bacterial DNA, and synthetic polydeoxyribonucleotides). The results obtained show that both compounds photobind to DNA to a higher extent than 8-MOP, taken as the reference drug. The capacity to form interstrand crosslinks into DNA helix was also evaluated. Interestingly, notwithstanding the lack of cutaneous phototoxicity, II revealed a good ability to induce diadduct formation.


Subject(s)
Coumarins/chemistry , Coumarins/toxicity , DNA/chemistry , Photosensitizing Agents/chemistry , Photosensitizing Agents/toxicity , Polydeoxyribonucleotides/chemistry , Skin/drug effects , Thiophenes/chemistry , Thiophenes/toxicity , Animals , Cattle , Cell Division/drug effects , Cell Division/radiation effects , DNA/drug effects , DNA, Bacterial/chemistry , HL-60 Cells , Humans , Kinetics , Methoxsalen/toxicity , Skin/pathology , Skin/radiation effects , Tumor Cells, Cultured , Ultraviolet Rays
18.
Thromb Res ; 98(1): 59-71, 2000 Apr 01.
Article in English | MEDLINE | ID: mdl-10706934

ABSTRACT

Previous reports have shown that various amines inhibited platelet activation, but no definitive conclusions on their action mechanism were drawn. We have further investigated the action of spermine on platelet responses evoked by alpha-thrombin and other agonists. Spermine inhibited in a concentration-dependent manner (1-10 mM), and more efficiently than spermidine and putrescine, the alpha-thrombin-induced (1.5 nM) platelet activation. Spermine added at a concentration that inhibited completely aggregation only partially affected the thrombin-induced increase in cytosolic Ca(2+) concentration, protein phosphorylation, and ATP secretion. The polyamine had little effect on the morphology of resting platelets, as measured by electron microscopy, thrombin hydrolytic activity, and fibrinogen clotting capacity but decreased the thrombin binding to platelets and isolated glycocalicin. Spermine partially inhibited the aggregation elicited by ADP, vasopressin, platelet-activating factor, thrombin receptor-activating peptide, fluoroaluminate, ionomycin, and dioctanoylglycerol but did not affect the cytosolic Ca(2+) increase induced by these agonists. The polyamine bound to both glycocalicin and platelets, and it inhibited the fibrinogen binding to stimulated platelets. The amount of 14C-spermine bound to resting cells decreased in the presence of the glycoprotein GPIb-antibody LJIB1, whereas the polyamine bound to activated platelets, which was higher than that tied to resting cells, was markedly reduced by LJCP8 or decorsin, a GPIIb/IIIa antibody and antagonist-peptide, respectively. These results indicate that spermine specifically inhibits the thrombin binding to GPIb of resting platelets and the fibrinogen binding to GPIIb/IIIa (integrin alpha(IIb)beta(3)) of activated platelets.


Subject(s)
Blood Platelets/drug effects , Platelet Aggregation Inhibitors/pharmacology , Platelet Aggregation/drug effects , Spermine/pharmacology , Adenosine Triphosphate/metabolism , Blood Platelets/physiology , Calcium/metabolism , Dose-Response Relationship, Drug , Humans , Thrombin/pharmacology
19.
Bioorg Med Chem Lett ; 10(2): 135-7, 2000 Jan 17.
Article in English | MEDLINE | ID: mdl-10673096

ABSTRACT

Benzoangelicins 4-6 were synthesized in good yields from 7-hydroxy-5-methoxy-4-methylcoumarin (1). In the absence of UVA radiation, compounds 5 and 6 were only weakly active against HL60 and HeLa tumour cells; in its presence, compound 6 was 10 times more active than the reference compound 8-methoxypsoralen. None of 4-6 exhibited cutaneous phototoxicity.


Subject(s)
Benzofurans/chemical synthesis , Coumarins/chemical synthesis , Photosensitizing Agents/chemical synthesis , Antineoplastic Agents/chemical synthesis , Antineoplastic Agents/pharmacology , Benzofurans/pharmacology , Coumarins/chemistry , Coumarins/pharmacology , DNA/metabolism , HL-60 Cells/drug effects , HeLa Cells/drug effects , Humans , Kinetics , Methoxsalen/pharmacology , Molecular Structure , Photosensitizing Agents/pharmacology , Ultraviolet Rays
20.
Biochemistry ; 39(2): 324-31, 2000 Jan 18.
Article in English | MEDLINE | ID: mdl-10630992

ABSTRACT

In the present study, the voltage-dependent mechanism of spermine transport in liver mitochondria [Toninello, A., Dalla Via, L., Siliprandi, D., and Garlid, K. D. (1992) J. Biol. Chem. 267, 18393-18397] was further characterized by determining the rate constants J(max) and K(m) as functions of membrane potential. An increase in mitochondrial membrane potential from 150 to 210 mV promoted spermine transport, as reflected by an approximate 4-fold increase in J(max) and 25% decrease in K(m). The mechanism for the voltage dependence of transport was examined using the beta value, i. e., the slope of ln(flux) vs FDeltaPsi/RT plots. Flux-voltage analyses performed at very high and very low spermine concentrations yielded beta values of 0.125 and 0.25, for J(max) and J(max)/K(m), respectively. The physical significance of these beta values was analyzed by means of a theory relating the enzyme reaction rate to the free energy profiles [Yagisawa, S. (1985) Biochem. J. 303, 305-311]. Depending on the nature of K(m), two possible models could be proposed to describe the location and shape of the barriers in the membrane. Analysis of previous data concerning spermine binding [Dalla Via, L., Di Noto, V., Siliprandi, D., and Toninello, A. (1996) Biochim. Biophys. Acta 1284, 247-252] by a new rationale provided evidence for an asymmetrical energy profile composed of two peaks with the binding site near the membrane surface followed by a rate-determining energy barrier for the movement of the bound spermine toward the internal region of the membrane.


Subject(s)
Mitochondria, Liver/metabolism , Spermine/metabolism , Animals , Biological Transport , Kinetics , Membrane Potentials , Rats , Spermine/chemistry , Statistics as Topic , Thermodynamics
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