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1.
Neurol Res ; 38(3): 187-95, 2016 Mar.
Article in English | MEDLINE | ID: mdl-26311576

ABSTRACT

BACKGROUND: Stroke continues to be a leading cause of mortality and morbidity worldwide, and novel therapeutic options for ischaemic stroke are urgently needed. In this context, drug combination therapies seem to be a viable approach, which has not been fully explored in preclinical studies. OBJECTIVES: In this work, we assessed the dose-response relationship and therapeutic time window, in global brain ischaemia, of a combined therapeutic approach of recombinant human epidermal growth factor (EGF) and growth hormone-releasing peptide-6 (GHRP-6). METHODS: Mongolian gerbils underwent 15 minutes occlusion of both common carotid arteries. Four different doses of rhEGF, GHRP-6 and these combined agents were intraperitoneally administered immediately after the onset of reperfusion. Having identified a better response with both agents, rhEGF+GHRP-6 were administered at 2, 4, 6, 8 or 24 hours after the onset of reperfusion to assess the time window of effectiveness. Animals were evaluated daily for neurological deficits. Three days post-occlusion, the animals were sacrificed and 2,3,5-triphenyltetrazolium chloride was used to quantify infarcted tissues. RESULTS: The coadministration of rhEGF and GHRP-6 at doses of 100 and 600 µg/kg, respectively, administered up to 4 hours following the ischaemic insult, significantly improved survival and neurological outcome, and reduced infarct volume compared with vehicle treatment. These results are considered as an additional proof of concept as supporting a combined therapeutic approach and justify the further development of this preclinical research.


Subject(s)
Drug Evaluation, Preclinical , Epidermal Growth Factor/therapeutic use , Oligopeptides/therapeutic use , Stroke/drug therapy , Animals , Disease Models, Animal , Dose-Response Relationship, Drug , Gerbillinae , Humans , Male , Neurologic Examination , Stroke/pathology , Time Factors
2.
MEDICC Rev ; 15(1): 11-5, 2013 01.
Article in English | MEDLINE | ID: mdl-23396236

ABSTRACT

Diabetic foot ulcer is a principal diabetic complication. It has been shown that diabetic patients have decreased growth factor concentrations in their tissues, particularly epidermal growth factor. Growth factor shortage impairs wound healing, which leads to chronic nonhealing wounds and sometimes eventual amputation. Ischemic diabetic foot ulcer is the most difficult to treat and confers the highest amputation risk. Injecting epidermal growth factor deep into the wound bottom and contours encourages a more effective pharmacodynamic response in terms of granulation tissue growth and wound closure. Epidermal growth factor injected into the ulcer matrix may also result in association with extracellular matrix proteins, thus enhancing cell proliferation and migration. Heberprot-P is an innovative Cuban product containing recombinant human epidermal growth factor for peri- and intra-lesional infiltration; evidence reveals it accelerates healing of deep and complex ulcers, both ischemic and neuropathic, and reduces diabetes-related amputations. Clinical trials of Heberprot-P in patients with diabetic foot ulcers have shown that repeated local infiltration of this product can enhance healing of chronic wounds safely and efficaciously. As a result, Heberprot-P was registered in Cuba in 2006, and in 2007 was included in the National Basic Medications List and approved for marketing. It has been registered in 15 other countries, enabling treatment of more than 100,000 patients. Heberprot-P is a unique therapy for the most complicated and recalcitrant chronic wounds usually associated with high amputation risk. Local injection in complex diabetic wounds has demonstrated a favorable risk-benefit ratio by speeding healing, reducing recurrences and attenuating amputation risk. Further testing and deployment worldwide of Heberprot-P would provide an opportunity to assess the product's potential to address an important unmet medical need.


Subject(s)
Diabetic Foot/drug therapy , Epidermal Growth Factor/administration & dosage , Amputation, Surgical , Clinical Trials as Topic , Cuba , Diabetic Foot/pathology , Humans , Recombinant Proteins/administration & dosage , Severity of Illness Index , Wound Healing/drug effects
3.
Eur J Pharm Sci ; 48(1-2): 40-6, 2013 Jan 23.
Article in English | MEDLINE | ID: mdl-23099431

ABSTRACT

GHRP-6 is a growth hormone secretagogue that also enhances tissue viability in different organs. In the present work, we studied the pharmacokinetics of this short therapeutic hexapeptide (His-(D-Trp)-Ala-Trp-(D-Phe)-Lys-NH(2,) MW=872.44 Da) in nine male healthy volunteers after a single intravenous bolus administration of 100, 200 and 400 µg/kg of body weight. GHRP-6 was quantified in human plasma by a specific LC-MS method, previously developed and validated following FDA guidelines, using (13)C(3)Ala-GHRP-6 as internal standard (Gil et al., 2012, J. Pharm. Biomed. Anal. 60, 19-25). The Lower Limit of Quantification (5 ng/mL) was reached in all subjects at 12h post-administration, which was sufficient for modeling a pharmacokinetic profile including over 85% of the Area under the Curve (AUC). Disposition of GHRP-6 best fitted a bi-exponential function with R(2) higher than 0.99, according to a mathematic modeling and confirmed by an Akaike index (AIC) lower than that of the corresponding one-compartment model for all subjects. Averaging all three dose levels, the distribution and elimination half-life of GHRP-6 were 7.6 ± 1.9 min and 2.5 ± 1.1h, respectively. These values are coherent with existing data for other drugs whose disposition also fits this model. Dose dependence analysis revealed a noticeable trend for AUC to increase proportionally with administered dose. Atypical GHRP-6 concentration spikes were observed during the elimination phase in four out of the nine subjects studied.


Subject(s)
Oligopeptides/pharmacokinetics , Administration, Intravenous , Adolescent , Adult , Area Under Curve , Dose-Response Relationship, Drug , Growth Hormone-Releasing Hormone , Humans , Male , Oligopeptides/blood , Young Adult
4.
Restor Neurol Neurosci ; 29(4): 243-52, 2011.
Article in English | MEDLINE | ID: mdl-21697595

ABSTRACT

PURPOSE: Multiple sclerosis is a complex and devastating autoimmune disease of the central nervous system. Up to now, a constellation of candidate drugs have been evaluated with no major success. Experimental Autoimmune Encephalitis (EAE) is the animal counterpart that reproduces critical features of the human MS process. The aim of the present work is to study a possible therapeutic effect of epidermal growth factor (EGF) and growth hormone releasing peptide-6 (GHRP(6)) coadministration in mild and severe EAE. METHODS: Mild and severe forms of EAE were generated immunizing rats and mice with xenogeneic spinal cord homogenate and with the encephalitogenic peptide MOG(p35-35), respectively. EGF and GHRP(6) alone or combined were administered in therapeutic and prophylactic schedules. A clinical score was established to follow-up the animals during the disease period. Malondialdehyde (MDA) serum concentration and insulin like growth factor-1 (IGF-1) relative level from brain tissue were determined. RESULTS: Only the combined EGF+GHRP(6) therapy reduced the clinical score in mild as well in severe EAE forms. The combination also improved the survival rate in nearly 100% of the severe EAE animals. In addition to these effects, there was an increase in the brain IGF-1 transcript and a decrease of serum MDA. CONCLUSIONS: EGF+GHRP(6) proved to be effective in improving the natural course of both mild and severe EAE. Accordingly, the treatment reduces inflammatory infiltration and microvascular damage, which may be associated to the attenuation of the lipid peroxidation process and the transcriptional enhancement of IGF-1, a major pro-survival factor for brain cells.


Subject(s)
Encephalomyelitis, Autoimmune, Experimental/drug therapy , Epidermal Growth Factor/pharmacology , Hormones/pharmacology , Multiple Sclerosis/drug therapy , Oligopeptides/pharmacology , Animals , Disease Models, Animal , Drug Therapy, Combination , Encephalomyelitis, Autoimmune, Experimental/metabolism , Epidermal Growth Factor/administration & dosage , Female , Hormones/administration & dosage , Insulin-Like Growth Factor I/metabolism , Malondialdehyde/blood , Mice , Mice, Inbred C57BL , Multiple Sclerosis/metabolism , Oligopeptides/administration & dosage , Rats , Rats, Inbred Lew , Severity of Illness Index , Treatment Outcome
5.
Neurotox Res ; 19(1): 195-209, 2011 Jan.
Article in English | MEDLINE | ID: mdl-20169434

ABSTRACT

Amyotrophic lateral sclerosis (ALS) is a disease of the central nervous system characterized by loss of spinal motor neurons, for which no effective treatment exists. Epidermal growth factor (EGF) and growth hormone releasing peptide-6 (GHRP-6) have been considered as good candidates for the treatment of this disease, due to their well documented effects in eliciting pleiotrophic and cell survival mechanisms. The aim of the present work was to evaluate the separate and combined effects of both peptides in an experimental animal model of ALS, the proximal axonopathy induced by 1,2 diacetylbenzene (1,2 DAB) in mice. The evaluations were conducted by means of behavioral tests (trapeze, tail suspension, gait pattern, and open field) and by recording the complex muscle action potential (CMAP) in three different hind limb segments: proximal S1, medial S2, and distal S3. Intraperitoneal daily administration of 1,2 DAB produced significant reduction in body weight, muscle strength, extensor reflex, spontaneous activity, and changes in gait pattern parameters. In parallel 1,2 DAB produced significant prolongation of onset latency and decrease in amplitude of CMAP and in the integrated complex action potential index. Daily administration of the separate compounds did not accelerate the recovery of the affected parameters, except for the gait pattern. The combined treatment produced significant improvement in behavioral parameters, as well as in electrophysiological recovery, particularly in the proximal segment of CMAP. The latter results confirm the proximal character of 1,2 DAB neuropathy, and suggest that combined therapy with EGF and GHRP-6 might be a good therapeutic strategy for the treatment of ALS.


Subject(s)
Amyotrophic Lateral Sclerosis/drug therapy , Axons/pathology , Disease Models, Animal , Epidermal Growth Factor/administration & dosage , Growth Hormone-Releasing Hormone/administration & dosage , Oligopeptides/administration & dosage , Amyotrophic Lateral Sclerosis/pathology , Animals , Axons/drug effects , Cell Survival/physiology , Drug Therapy, Combination , Female , Mice , Mice, Inbred C57BL , Neuroprotective Agents/administration & dosage
6.
Expert Rev Neurother ; 8(5): 819-25, 2008 May.
Article in English | MEDLINE | ID: mdl-18457538

ABSTRACT

In most tissues, the immune system plays an essential role in protection, repair and healing. Although immunologically privileged, the CNS remains subject to a highly regulated form of immunosurveillance that is of increasing interest. There is evolving evidence that repair mechanisms within the CNS may be enhanced by exploiting an innate process of protective immunity. Understanding the regulation of protective autoimmunity within the CNS is likely to lead to novel therapeutic approaches to neuroinflammatory and neurodegenerative diseases.


Subject(s)
Autoimmunity/immunology , Brain Diseases/immunology , Brain Diseases/prevention & control , Brain/drug effects , Brain/immunology , Neuroprotective Agents/immunology , Neuroprotective Agents/therapeutic use , Animals , Autoimmunity/drug effects , Drug Delivery Systems/methods , Humans , Models, Immunological
7.
Transpl Int ; 21(1): 39-48, 2008 Jan.
Article in English | MEDLINE | ID: mdl-17927680

ABSTRACT

The liver is damaged by sustained ischemia in liver transplantation, and the reperfusion after ischemia results in further functional impairment. Ozone oxidative preconditioning (OzoneOP) protected the liver against ischemia/reperfusion (I/R) injury. The aim of this study was to investigate the role of A(1) adenosine receptor on the protective actions conferred by OzoneOP in hepatic I/R. By using a specific agonist and antagonist of the A(1) subtype receptor (2-chloro N6 cyclopentyladenosine, CCPA and 8-cyclopentyl-1,3-dipropylxanthine, DPCPX respectively), we studied the role of A(1) receptor in the protective effects of OzoneOP on the liver damage, nitiric oxide (NO) generation, adenosine deaminase activity and preservation of the cellular redox balance. Immunohistochemical analysis of nuclear factor-kappa B (NF-kappaB), tumor necrosis factor alpha (TNF-alpha) and heat shock protein-70 (HSP-70) was performed. OzoneOP prevented and/or ameliorated ischemic damage. CCPA showed a similar effect to OzoneOP + I/R group. A(1)AR antagonist DPCPX blocked the protective effect of OzoneOP. OzoneOP largely reduced the intensity of the p65 expression, diminished TNF-alpha production, and promoted a reduction in HSP-70 immunoreactivity. In summary, OzoneOP exerted protective effects against liver I/R injury through activation of A(1) adenosine receptors (A(1)AR). Adenosine and (.)NO produced by OzoneOP may play a role in the pathways of cellular signalling which promote preservation of the cellular redox balance, mitochondrial function, glutathione pools as well as the regulation of NF-kappaB and HSP-70.


Subject(s)
Ischemic Preconditioning/methods , Liver Transplantation/methods , Liver/blood supply , Ozone/therapeutic use , Receptor, Adenosine A1/metabolism , Reperfusion Injury/prevention & control , Adenosine/analogs & derivatives , Adenosine/pharmacology , Adenosine A1 Receptor Antagonists , Animals , Biomarkers/metabolism , Disease Models, Animal , HSP72 Heat-Shock Proteins/metabolism , Immunohistochemistry , Male , NF-kappa B/metabolism , Nitric Oxide/biosynthesis , Oxidants, Photochemical/therapeutic use , Oxidative Stress/drug effects , Oxidative Stress/physiology , Purinergic P1 Receptor Antagonists , Rats , Rats, Wistar , Reperfusion Injury/metabolism , Reperfusion Injury/pathology , Treatment Outcome , Tumor Necrosis Factor-alpha/metabolism , Xanthines/pharmacology
8.
Clin Sci (Lond) ; 112(4): 241-50, 2007 Feb.
Article in English | MEDLINE | ID: mdl-16989643

ABSTRACT

Therapies aimed at enhancing cardiomyocyte survival following myocardial injury are urgently required. As GHRP6 [GH (growth hormone)-releasing peptide 6] has been shown to stimulate GH secretion and has beneficial cardiovascular effects, the aim of the present study was to determine whether GHRP6 administration reduces myocardial infarct size following acute coronary occlusion in vivo. Female Cuban Creole pigs were anaesthetized, monitored and instrumented to ensure a complete sudden left circumflex artery occlusion for 1 h, followed by a 72 h reperfusion/survival period. Animals were screened clinically before surgery and assigned randomly to receive either GHRP6 (400 microg/kg of body weight) or normal saline. Hearts were processed, and the area at risk and the infarct size were determined. CK-MB (creatine kinase MB) and CRP (C-reactive protein) levels and pathological Q-wave-affected leads were analysed and compared. Evaluation of the myocardial effect of GHRP6 also included quantitative histopathology, local IGF-I (insulin-growth factor-I) expression and oxidative stress markers. GHRP6 treatment did not have any influence on mortality during surgery associated with rhythm and conductance disturbances during ischaemia. Infarct mass and thickness were reduced by 78% and 50% respectively, by GHRP6 compared with saline (P<0.01). More than 50% of the GHRP6-treated pigs did not exhibit pathogological Q waves in any of the ECG leads. Quantitative histopathology and CK-MB and CRP serum levels confirmed the reduction in GHRP6-mediated necrosis (all P<0.05). Levels of oxidative stress markers suggested that GHRP6 prevented myocardial injury via a decrease in reactive oxygen species and by the preservation of antioxidant defence systems (all P<0.05). Myocardial IGF-I transcription was not amplified by GHRP6 treatment compared with the increase induced by the ischaemic episode in relation to expression in intact hearts (P<0.01). In conclusion, GHRP6 exhibits antioxidant effects which may partially contribute to reduce myocardial ischaemic damage.


Subject(s)
Antioxidants/therapeutic use , Cardiotonic Agents/therapeutic use , Myocardial Infarction/drug therapy , Myocytes, Cardiac/drug effects , Oligopeptides/therapeutic use , Animals , Arrhythmias, Cardiac/prevention & control , C-Reactive Protein/metabolism , Cell Survival/drug effects , Creatine Kinase, MB Form/blood , Disease Models, Animal , Electrocardiography/drug effects , Female , Insulin-Like Growth Factor I/metabolism , Myocardial Infarction/metabolism , Myocardial Infarction/pathology , Myocardium/pathology , Myocytes, Cardiac/pathology , Necrosis/prevention & control , Organ Size/drug effects , Oxidation-Reduction , Oxidative Stress/drug effects , Swine
9.
Arch Med Res ; 37(6): 717-22, 2006 Aug.
Article in English | MEDLINE | ID: mdl-16824930

ABSTRACT

BACKGROUND: Cellular events in cisplatin-mediated nephrotoxicity include apoptosis induction, decreased protein synthesis, changes in the subcellular redistribution of Bax mitochondrial dysfunction, DNA injury, increased lipid peroxidation, depletion of glutathione and decrease in enzymatic activity of renal antioxidant enzymes. In previous papers we have shown that intra-rectal (i.r.) ozone/oxygen mixture protected and induced a significant recovery in cisplatin-induced renal damage and was related to a significant increase in the antioxidant system in renal tissue. METHODS: This study was undertaken to examine the effect of the ir applications of ozone/oxygen mixture in the renal expression pattern of Bax proteins in rats treated with cisplatin. A group of male Sprague-Dawley rats was pretreated with 15 i.r. applications of ozone/oxygen (1.1 mg/kg) before intraperitoneal injection of cisplatin (6 mg/kg). Another group was treated with five i.r. applications of ozone/oxygen mixture after cisplatin administration. Serum creatinine was measured thereafter. Subcellular distribution of Bax in renal tissue was analyzed by immunohistochemistry. RESULTS: Ozone pretreatment prevented the increase in serum creatinine levels and completely inhibited the acute tubular necrosis induced by cisplatin in renal tissue, diminishing the expression of Bax. Ozone treatment after cisplatin application reduced the increase in serum creatinine levels and the renal necrosis, inducing a lesser decrease of the Bax expression in cisplatin-treated kidneys. CONCLUSIONS: Expression of Bax in renal tissue seems to play an important role in the protection and recovery in cisplatin-nephrotoxicity achieved by ozone/oxygen mixture.


Subject(s)
Antineoplastic Agents , Cisplatin , Kidney/drug effects , Oxidants, Photochemical/pharmacology , Oxygen/metabolism , Ozone/pharmacology , bcl-2-Associated X Protein/metabolism , Animals , Antineoplastic Agents/pharmacology , Antineoplastic Agents/toxicity , Antioxidants/metabolism , Cisplatin/pharmacology , Cisplatin/toxicity , Creatinine/blood , Humans , Kidney/metabolism , Kidney/pathology , Male , Oxidants, Photochemical/metabolism , Oxidation-Reduction , Ozone/metabolism , Rats , Rats, Sprague-Dawley
10.
Clin Sci (Lond) ; 110(5): 563-73, 2006 May.
Article in English | MEDLINE | ID: mdl-16417467

ABSTRACT

Novel therapies for the treatment of MOF (multiple organ failure) are required. In the present study, we examined the effect of synthetic GHRP-6 (growth hormone-releasing peptide-6) on cell migration and proliferation using rat intestinal epithelial (IEC-6) and human colonic cancer (HT29) cells as in vitro models of injury. In addition, we examined its efficacy when given alone and in combination with the potent protective factor EGF (epidermal growth factor) in an in vivo model of MOF (using two hepatic vessel ischaemia/reperfusion protocols; 45 min of ischaemia and 45 min of reperfusion or 90 min of ischaemia and 120 min of reperfusion). In vitro studies showed that GHRP-6 directly influenced gut epithelial function as its addition caused a 3-fold increase in the rate of cell migration of IEC-6 and HT29 cells (P<0.01), but did not increase proliferation ([3H]thymidine incorporation). In vivo studies showed that, compared with baseline values, ischaemia/reperfusion caused marked hepatic and intestinal damage (histological scoring), neutrophilic infiltration (myeloperoxidase assay; 5-fold increase) and lipid peroxidation (malondialdehyde assay; 4-fold increase). Pre-treatment with GHRP-6 (120 microg/kg of body weight, intraperitoneally) alone truncated these effects by 50-85% (all P<0.05) and an additional benefit was seen when GHRP-6 was used in combination with EGF (1 mg/kg of body weight, intraperitoneally). Lung and renal injuries were also reduced by these pre-treatments. In conclusion, administration of GHRP-6, given alone or in combination with EGF to enhance its effects, may provide a novel simple approach for the prevention and treatment of MOF and other injuries of the gastrointestinal tract. In view of these findings, further studies appear justified.


Subject(s)
Growth Hormone-Releasing Hormone/therapeutic use , Multiple Organ Failure/prevention & control , Animals , Cell Movement/drug effects , Cell Proliferation/drug effects , Cells, Cultured , Dose-Response Relationship, Drug , Epidermal Growth Factor/pharmacology , Growth Hormone-Releasing Hormone/pharmacology , Humans , Intestinal Mucosa/cytology , Intestinal Mucosa/drug effects , Lipid Peroxidation/drug effects , Male , Multiple Organ Failure/metabolism , Multiple Organ Failure/pathology , Neutrophil Infiltration/drug effects , Oligopeptides , Rats , Rats, Wistar , Recombinant Proteins/pharmacology , Reperfusion Injury/metabolism , Reperfusion Injury/pathology , Reperfusion Injury/prevention & control , Tumor Cells, Cultured
11.
Biotecnol Apl ; 23(1): 54-59, 2006. gràfilus
Article in English | CUMED | ID: cum-36472

ABSTRACT

The objective of this work was the generation of an animal model of the SCA2 disease for future studies on thebenefits of therapeutic molecules and the underlying neuropathological mechanisms in this human disorder. Thetransgenic fragment was microinjected into pronuclei of B6D2F1 X OF1 mouse hybrid strain. For Northern blots,RNAs were hybridized with a human cDNA fragment from the SCA2 gene and a mouse b-actin cDNA fragment.Monoclonal antibodies directed at the N-terminal of the ataxin 2 protein with 22Q were used for Western blotanalysis. A rotating rod apparatus was utilized to measure motor coordination of mice. Immunohistochemicaldetection of Purkinje neurons was performed with anti-calbindin 28K as the primary antibody. An ubiquitousexpression of the SCA2 transgene with 75 CAG repeats regulated by the SCA2 self promoter was obtained afterthe generation of our transgenic mice. The analysis of transgenic mice revealed significant differences of motorcoordination compared with the wild type littermates. A specific degeneration of Purkinje neurons and transgeneover-expression in the brain, liver and skeletal muscle, rather than in lungs and kidneys was also observed, resemblingthe expression pattern of the ataxin 2 in humans...(AU)


Subject(s)
Animals , Mice, Transgenic , Spinocerebellar Ataxias
12.
Neurosci Lett ; 392(3): 202-6, 2006 Jan 16.
Article in English | MEDLINE | ID: mdl-16203087

ABSTRACT

The objective of this work was the generation of an animal model of the SCA2 disease for future studies on the benefits of therapeutic molecules and neuropathological mechanisms that underline this human disorder. The transgenic fragment was microinjected into pronuclei of B6D2F1 X OF1 mouse hybrid strain. For Northern blots, RNAs were hybridized with a human cDNA fragment from the SCA2 gene and a mouse beta-actin cDNA fragment. Monoclonal antibody directed to the N-terminal of the ataxin 2 protein with 22Q was used for Western blot analysis. A rotating rod apparatus was utilized to measure motor coordination of mice. Immunohistochemical detection of Purkinje neurons was performed with anti-calbindin 28K as primary antibody. Ubiquitous expression of the SCA2 transgene with 75 CAG repeats regulated by the SCA2 self promoter was obtained after generation of our transgenic mice. Analysis of transgenic mice revealed significant differences of motor coordination compared with the wild type littermates. Specific degeneration of Purkinje neurons and transgene over-expression in the brain, liver and skeletal muscle, rather than in lungs and kidneys was also observed, resembling the expression pattern of the ataxin 2 in humans.


Subject(s)
Nerve Tissue Proteins/metabolism , Promoter Regions, Genetic/physiology , Purkinje Cells/pathology , Spinocerebellar Degenerations/metabolism , Spinocerebellar Degenerations/pathology , Analysis of Variance , Animals , Ataxins , Blotting, Northern/methods , Blotting, Western/methods , Calbindin 1 , Calbindins , Disease Models, Animal , Humans , Immunohistochemistry/methods , Mice , Mice, Transgenic , Motor Activity/physiology , Nerve Tissue Proteins/genetics , Purkinje Cells/metabolism , RNA, Messenger/biosynthesis , Regulatory Sequences, Nucleic Acid , Reverse Transcriptase Polymerase Chain Reaction/methods , Rotarod Performance Test/methods , S100 Calcium Binding Protein G/metabolism , Spinocerebellar Degenerations/physiopathology , Time Factors
13.
Transpl Int ; 18(5): 604-12, 2005 May.
Article in English | MEDLINE | ID: mdl-15819811

ABSTRACT

The liver is damaged by sustained ischaemia during liver transplantation, and the reperfusion after ischaemia results in further functional impairment. Ozone oxidative preconditioning (OzoneOP) protected the liver against ischaemia/reperfusion (I/R) injury through different mechanisms. The aim of this study was to investigate the influence of the inhibition of protein synthesis on the protective actions conferred by OzoneOP in hepatic I/R. Rats were treated with cycloheximide (CHX) in order to promote protein synthesis inhibition after OzoneOP treatment. Plasma transaminases, malondialdehyde and 4-hydroxyalkenals and morphological characteristics were measured as an index of hepatocellular damage; Cu/Zn-superoxide dismutase (SOD), Mn-SOD, catalase, total hydroperoxides and glutathione levels as markers of endogenous antioxidant system. OzoneOP increased Mn-SOD isoform and ameliorated mitochondrial damage. CHX abrogated the protection conferred by OzonoOP and decreased Mn-SOD activity. Cellular redox balance disappeared when CHX was introduced. Protein synthesis is involved in the protective mechanisms mediated by OzoneOP. Ozone treatment preserved mitochondrial functions and cellular redox balance.


Subject(s)
Liver Transplantation , Liver/injuries , Liver/metabolism , Ozone/administration & dosage , Protein Biosynthesis , Alanine Transaminase/blood , Animals , Aspartate Aminotransferases/blood , Catalase/metabolism , Cycloheximide/pharmacology , Glutathione/metabolism , Glutathione Disulfide/metabolism , Ischemic Preconditioning , Liver/drug effects , Liver/ultrastructure , Liver Transplantation/adverse effects , Liver Transplantation/physiology , Male , Microscopy, Electron , Oxidation-Reduction , Protein Synthesis Inhibitors/pharmacology , Rats , Rats, Wistar , Superoxide Dismutase/metabolism
14.
Clin Sci (Lond) ; 109(1): 83-95, 2005 Jul.
Article in English | MEDLINE | ID: mdl-15755259

ABSTRACT

Increased formation of MG (methylglyoxal) and related protein glycation in diabetes has been linked to the development of diabetic vascular complications. Diabetes is also associated with impaired wound healing. In the present study, we investigated if prolonged exposure of rats to MG (50-75 mg/kg of body weight) induced impairment of wound healing and diabetes-like vascular damage. MG treatment arrested growth, increased serum creatinine, induced hypercholesterolaemia (all P < 0.05) and impaired vasodilation (P < 0.01) compared with saline controls. Degenerative changes in cutaneous microvessels with loss of endothelial cells, basement membrane thickening and luminal occlusion were also detected. Acute granulation appeared immature (P < 0.01) and was associated with an impaired infiltration of regenerative cells with reduced proliferative rates (P < 0.01). Immunohistochemical staining indicated the presence of AGEs (advanced glycation end-products) in vascular structures, cutaneous tissue and peripheral nerve fibres. Expression of RAGE (receptor for AGEs) appeared to be increased in the cutaneous vasculature. There were also pro-inflammatory and profibrotic responses, including increased IL-1beta (interleukin-1beta) expression in intact epidermis, TNF-alpha (tumour necrosis factor-alpha) in regions of angiogenesis, CTGF (connective tissue growth factor) in medial layers of arteries, and TGF-beta (transforming growth factor-beta) in glomerular tufts, tubular epithelial cells and interstitial endothelial cells. We conclude that exposure to increased MG in vivo is associated with the onset of microvascular damage and other diabetes-like complications within a normoglycaemic context.


Subject(s)
Diabetic Angiopathies/chemically induced , Pyruvaldehyde/pharmacology , Skin/injuries , Wound Healing , Animals , Blood Glucose/analysis , Cholesterol/blood , Diabetic Angiopathies/immunology , Diabetic Angiopathies/physiopathology , Disease Models, Animal , Fructosamine/blood , Injections, Intraperitoneal , Interleukin-1/analysis , Male , Microcirculation , Neovascularization, Pathologic , Random Allocation , Rats , Rats, Wistar , Skin/blood supply , Skin/immunology , Triglycerides/blood , Tumor Necrosis Factor-alpha/analysis , Vasodilation/drug effects
15.
Burns ; 28(5): 435-42, 2002 Aug.
Article in English | MEDLINE | ID: mdl-12163282

ABSTRACT

Major burns are associated with multiple internal organ damages, including necrosis of the gastrointestinal mucosa. Failure of the intestinal barrier is a serious complication in burned patients. Epidermal growth factor (EGF) is a mitogenic polypeptide that stimulates wound repair and affords protection to the gastric mucosa. We examined whether a single systemic intervention with EGF prevents organ systems damages, following full-thickness scalds (25-30%) in rodents. Animals were randomly assigned to receive an intraperitoneal injection of EGF (30 microg/kg in mice, 10 microg/kg in rats) or saline solution, 30 min prior thermal injury in mice or after the cutaneous injury in rats. General clinical condition and mortality during 24h were recorded. Animals were autopsied and histopathological and histomorphometric studies were conducted. Mice treated with EGF exhibited a milder clinical evolution and acute lethality was significantly reduced as compared to saline counterparts (P<0.01). Histopathological and morphometric analysis showed that EGF significantly reduced intestinal necrosis and contributed to preserve jejunoileal architecture in mice (P<0.05) and rats (P<0.01). The onset of renal hemorrhagic foci was significantly reduced in EGF-treated groups (P<0.01). Lung damages appeared attenuated in EGF-treated animals. These data indicate the salutary effects of EGF by attenuating internal complications associated to thermal injuries. Further studies are warranted to fully elucidate the usefulness of this therapy.


Subject(s)
Burns/complications , Epidermal Growth Factor/therapeutic use , Multiple Organ Failure/etiology , Multiple Organ Failure/prevention & control , Animals , Burns/pathology , Digestive System/drug effects , Digestive System/pathology , Disease Models, Animal , Epidermal Growth Factor/administration & dosage , Injections, Intraperitoneal , Male , Mice , Mice, Inbred BALB C , Multiple Organ Failure/pathology , Random Allocation , Rats , Rats, Sprague-Dawley , Time Factors , Trauma Severity Indices
16.
Am J Pathol ; 161(2): 373-9, 2002 Aug.
Article in English | MEDLINE | ID: mdl-12163361

ABSTRACT

Ischemia/reperfusion of mesenteric vessels is a useful model for acute vascular insufficiency and the early stages of multiorgan failure, conditions associated with high morbidity and mortality. Epidermal growth factor (EGF) is a potent mitogen that shows potential for use in intestinal injury. We therefore examined its influence on this model. Male Sprague-Dawley rats received human recombinant EGF (2 mg/kg i.p., n = 14) or saline (n = 16); 25 minutes before arterial clamping of the superior mesenteric artery (ischemic period) for 60 minutes followed by a final 60-minute reperfusion period. Additional rats were not operated on (controls, n = 7) or had sham operation (laparotomy only, n = 10). Ischemia/reperfusion caused macroscopic damage affecting 56%, 51 to 67% (median, interquartile range), of small intestinal length and intraluminal bleeding. Malondialdehyde levels (free radical marker) increased eightfold compared to nonoperated animals (2400, 2200 to 2700 micro mol/mg protein versus 290, 250 to 350 micro mol/mg protein, P < 0.01) and myeloperoxidase levels (marker for inflammatory infiltrate) increased 15-fold (3150, 2670 to 4180 U/g tissue versus 240, 190 to 250 U/g tissue, P < 0.01). Pretreatment with EGF reduced macroscopic injury to 11%, 0 to 15%; prevented intraluminal bleeding; and reduced malondialdehyde and myeloperoxidase levels by approximately 60% and 90% (all P < 0.01 versus non-EGF-treated). Mesenteric ischemia/reperfusion also damaged the lungs and kidneys and increased serum tumor necrosis factor-alpha levels (circulating cytokine activity marker). EGF pretreatment also reduced these changes. These studies provide preliminary evidence that EGF is a novel therapy for the early treatment or prevention of intestinal damage and multiorgan failure resulting from mesenteric hypoperfusion.


Subject(s)
Epidermal Growth Factor/administration & dosage , Intestines/blood supply , Reperfusion Injury/prevention & control , Animals , Humans , Injections, Intraperitoneal , Intestines/drug effects , Intestines/pathology , Male , Mesenteric Arteries/pathology , Rats , Rats, Sprague-Dawley , Recombinant Proteins/administration & dosage , Reperfusion Injury/pathology
17.
Rev. cuba. med. trop ; 50(Suppl): 235-40, 1998. graf
Article in Spanish | CUMED | ID: cum-17025

ABSTRACT

Se amplificaron secuencias virales del LCR empleando líquido cefalorraquídeo de pacientes con el empleo de oligonucleótidos homólogos con la región 5ïde los Enterovirus, los resultados arrojaron una gran variabilidad en las secuencias amplificadas, sugiriendo la presencia de cuasiespecies enterovirales con propiedades biológicas alteradas en los individuos estresados, que pueden desempeñar una función fundamental en el daño neurológico (AU)


Subject(s)
Neuritis/epidemiology , Neuritis/etiology , Disease Outbreaks , Cuba
18.
Rev. cuba. med. trop ; 50(Supl): 235-40, 1998. graf
Article in Spanish | LILACS | ID: lil-260735

ABSTRACT

Se amplificaron secuencias virales del LCR empleando líquido cefalorraquídeo de pacientes con el empleo de oligonucleótidos homólogos con la región 5ïde los Enterovirus, los resultados arrojaron una gran variabilidad en las secuencias amplificadas, sugiriendo la presencia de cuasiespecies enterovirales con propiedades biológicas alteradas en los individuos estresados, que pueden desempeñar una función fundamental en el daño neurológico


Subject(s)
Cuba , Disease Outbreaks , Neuritis/epidemiology , Neuritis/etiology
19.
Biotecnol. apl ; 14(3): 163-8, jul.-sept. 1997. tab, graf
Article in English | CUMED | ID: cum-11528

ABSTRACT

Se estudió la respuesta reparativa de lesiones de grosor total en cerdos ante variaciones en la frecuencia de aplicación de una formulación con factor de crecimiento epidérmico (FCE, 10 µ/g) y sulfadiacina de plata 1 porciento. Se indujeron 100 lesiones de 8 mm que se agruparon y trataron como: I, II, II, tratados con FCE cada 24, 48 y 72 h, respectivamente. Los grupos IV y V fueron controles medicado y espontáneo. Los animales se sacrificaron al octavo día y se colectaron las úlceras para estudio histológico o planimétrico (10/10). Se estudiaron los siguientes parámetros; porciento de área total reepitelizada, radio medio, factor de circularidad, perímetro, crecimiento lineal del epitelio, reconstitución dérmica, migración epitelial, e índice de contracción. Las heridas del grupo 1 mostraron un 80 porciento de reepitelización total, la que fue significativamente superior al resto de los grupos (P<0,05). Estas mostraron el mayor nivel de crecimiento lineal y los menores valores de radio medio y perímetro con respecto a los otros grupos (P<0,05). Se constató un incremento significativo de la migración en todos los grupos tratados con FCE con relación al grupo IV, (p<0,05). La circularidad fue significativamente menor en el grupo I con relación a los otros grupos (p<0,05). La reconstitución de la dermis fue significativamente superior en los grupos I y II con respecto al IV (p<0,05). No se demostraron diferencias en el nivel de contracción de las heridas. Este experimento demostró que el FCE estimula la reparación cutánea de forma frecuencia de tratamiento-dependiente (AU)


Subject(s)
Animals , Epidermal Growth Factor/pharmacology , Silver Sulfadiazine/pharmacology , Wound Healing , Swine
20.
Rev. sanid. mil ; 47(2): 52-8, mar.-abr. 1993. ilus
Article in Spanish | LILACS | ID: lil-134967

ABSTRACT

Se informan tres casos de adenoma microquístico, un caso de tumor papilar y quístico, un caso de cistadenocarcinoma mucinoso, un caso de leiomiosarcoma y un casos de carcinoma insular no funcionante del páncreas. Se recalca la importancia de los aspectos clínicos, histológicos, inmunohistoquímicos, ultraestructurales, y de la citometría de flujo para poder identificar estas neoplasias tan poco frecuentes. Se hace una revisión de la literatura médica pertinente y se señalan los procedimientos de diagnóstico y tratamiento


Subject(s)
Humans , Male , Female , Adult , Middle Aged , Pancreatic Neoplasms/diagnosis , Pancreatic Neoplasms/pathology , Carcinoma/diagnosis , Carcinoma/pathology , Microscopy, Electron , Histological Techniques/instrumentation , Histological Techniques , Sarcoma/diagnosis , Sarcoma/pathology
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