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1.
Vet Rec ; 174(17): 431, 2014 Apr 26.
Article in English | MEDLINE | ID: mdl-24591478

ABSTRACT

Porcine circovirus type 2 (PCV2) causes some of the most significant economic losses in pig production. Several multisystemic syndromes have been attributed to PCV2 infection, which are known as PCV2-associated diseases (PCVDs). This study investigated the origin and evolution of PCV2 sequences in domestic pigs and wild boars affected by PCVDs in Croatia. Viral sequences were recovered from three wild boars diagnosed with PCV2-systemic disease (PCV2-SD), 63 fetuses positive for PCV2 DNA as determined by PCR, 14 domestic pigs affected with PCV2-SD (displaying severe interstitial nephritis) and five domestic pigs with proliferative and necrotising pneumonia. Seventeen complete PCV2 genomes were recovered. Phylogenetic and evolutionary analyses based on median-joining phylogenetic networks, amino acid alignments and principal coordinate analysis were performed using complete genomes, as well as complete and partial ORF sequences for ORF1 and ORF2. Two of the 17 PCV2 sequences belonged to PCV2a, 14 to PCV2b and one was unclustered. PCV2b was the predominant genotype in Croatia and has been linked to international trade as a route of introduction. Correlation between particular viral strains with PCVDs is lacking.


Subject(s)
Circoviridae Infections/veterinary , Circovirus/genetics , Phylogeny , Swine Diseases/virology , Animals , Circoviridae Infections/virology , Croatia , DNA, Viral/genetics , Genome, Viral , Polymerase Chain Reaction/veterinary , Swine
2.
Transplant Proc ; 46(1): 284-5, 2014.
Article in English | MEDLINE | ID: mdl-24507069

ABSTRACT

Chest pain is the main presenting symptom in patients with acute myocardial infarction. However, many patients present with atypical symptoms, which may delay proper diagnosis and treatment. We present the first documented case of pain in the left ear as an atypical presentation of acute myocardial infarction 5 days after renal transplantation.


Subject(s)
Ear/pathology , Kidney Transplantation , Myocardial Infarction/diagnosis , Pain/diagnosis , Renal Insufficiency/complications , Renal Insufficiency/surgery , Acute Coronary Syndrome/diagnosis , Chest Pain/diagnosis , Humans , Male , Middle Aged , Myocardial Infarction/complications , Symptom Assessment , Transplant Recipients
3.
Transplant Proc ; 45(9): 3190-1, 2013 Nov.
Article in English | MEDLINE | ID: mdl-24182782

ABSTRACT

Racial and ethnic disparities exist in access to kidney transplantation worldwide. The Roma people are often socially deprived, uneducated, and unemployed. We investigated all dialysis centers in Croatia to determine number of Roma people on dialysis as well as their access and reasons for eventual failure to enter the waiting list. There are 9463 registered Roma people in Croatia, however, the estimated number reaches 40,000. Twenty-five Roma patients required renal replacement therapy, giving a prevalence of 830 per million people (pmp), compared with 959 pmp among the general population. Average age at the start of dialysis was 29 vs 67 years; waiting time to kidney transplantation was 48.9 vs 53.5 months; mean age at the time of transplantation was 33.18 vs 48.01 years in Roma versus the general population respectively. One patient received a kidney allograft from a living unrelated spousal donor, and all others from deceased individuals. Patients were followed for 51.5 months (range, 6-240). The most frequent post-transplant complications were urinary tract infections. One patient lost a graft due to severe acute rejection caused by noncompliance. Two young patients were also noncompliant with immunosuppressive medications. One patient died with a functioning graft at 20 years after transplantation due to cardiovascular disease. Among 14 Roma patients currently been treated with hemodialysis in Croatia, 10 are old with clinical contraindications for transplantation; 1 is on the waiting list; 1 left hospitalization for pretransplant evaluation twice; 1 refused evaluation; and 1 is currently being evaluated for the waiting list. The Roma people have excellent access to renal transplantation in Croatia. Many of them refuse evaluation. More efforts should be invested in their education to improve compliance and their post-transplant outcomes.


Subject(s)
Ethnicity , Kidney Transplantation , Roma , Social Justice , Adult , Aged , Croatia , Humans , Middle Aged , Renal Replacement Therapy
4.
Vet Rec ; 171(21): 529, 2012 Nov 24.
Article in English | MEDLINE | ID: mdl-23104589

ABSTRACT

Torque teno virus (TTV) is ubiquitous and species-specific, and two different TTV species, Torque teno sus virus 1 (TTSuV1) and Torque teno sus virus 2 (TTSuV2), have been described in domestic pigs and wild boars. Whether these two species are involved in clinical cases of porcine circovirus type 2-associated disease (PCVDs) remains unknown. This study investigates the presence of TTSuV in 85 fetuses, pigs and wild boars infected by PCV2 and affected by PCVDs other than postweaning multisystemic wasting syndrome (PMWS) and porcine dermatitis and nephropathy syndrome. It also explores the genetic diversity of identified strains using phylogenetic analysis. The presence or absence of TTSuV was determined in 85 samples of PCV2-containing organs from 85 infected animals using a specific, one-step PCR method. A nucleotide distance matrix between sequences was computed to infer phylogeny based on a median-joining (MJ) network. TTSuV2 showed high prevalence in animals affected by nephropathy and proliferative and necrotising pneumonia (PNP), and both TTSuV1 and TTSuV2 showed high prevalence in wild boars affected by PMWS. TTSuV1 showed low prevalence in animals affected by nephropathy and PNP, and both TTSuV1 and TTSuV2 showed low prevalence in animals with reproductive disorders. MJ network analysis revealed significant genetic diversity among Croatian isolates.


Subject(s)
DNA Virus Infections/veterinary , Porcine Postweaning Multisystemic Wasting Syndrome/virology , Sus scrofa , Swine Diseases/virology , Torque teno virus , Animals , Animals, Newborn , Circovirus/classification , Circovirus/genetics , Circovirus/isolation & purification , Croatia/epidemiology , DNA Virus Infections/epidemiology , DNA Virus Infections/virology , Female , Genetic Variation , Male , Phylogeny , Porcine Postweaning Multisystemic Wasting Syndrome/epidemiology , Species Specificity , Swine , Swine Diseases/epidemiology , Torque teno virus/classification , Torque teno virus/genetics , Torque teno virus/isolation & purification
5.
Acta Vet Hung ; 55(3): 389-404, 2007 Sep.
Article in English | MEDLINE | ID: mdl-17867466

ABSTRACT

This report describes the first case of postweaning multisystemic wasting syndrome (PMWS) in wild boar in Croatia. During the winter season of 2004, eight wild young piglets (of approximately 2 to 5 months of age) were found dead in a fenced hunting area. Polymerase chain reaction (PCR) was carried out on mesenteric lymph nodes and all animals yielded positive results. In one of these animals diagnosis of PMWS was established based on the three key diagnostic criteria including the clinical manifestation, moderate lymphoid lesions consisting of lymphocyte depletion and granulomatous inflammation, and detection of the presence of PCV2 genome within the lymphoid lesions by in situ hybridisation (ISH). Three additional wild piglets had also mild PMWS-like lesions and a low amount of PCV2 was also found. No PMWS-like lesions or PCV2 genome were detected in the rest of the wild piglets studied. Three PCR-positive isolates were partially sequenced, which confirmed the diagnosis of PCV2 and demonstrated that the three sequences were genetically identical. The phylogenetic analysis of a representative PCV2 isolate indicated that its sequence (DQ875444) is grouped in a separate branch with Hungarian isolate (AY256460) and differs from any of the annotated sequences.


Subject(s)
Circovirus/classification , Phylogeny , Porcine Postweaning Multisystemic Wasting Syndrome/epidemiology , Sus scrofa , Animals , Animals, Newborn , Base Sequence , Croatia/epidemiology , In Situ Hybridization/veterinary , Molecular Sequence Data , Polymerase Chain Reaction/veterinary , Porcine Postweaning Multisystemic Wasting Syndrome/pathology , Porcine Postweaning Multisystemic Wasting Syndrome/virology , Swine
6.
Endothelium ; 6(3): 175-84, 1999.
Article in English | MEDLINE | ID: mdl-10365769

ABSTRACT

The renin-angiotensin system plays an important role in the pathophysiology of hypertension. We studied vascular function in the aorta of mouse Ren-2 transgenic rats (TGR(mRen2)27). Changes in isometric tension of isolated aorta of TGR(mRen2)27 and Sprague-Dawley rats (SD) were recorded in organ chambers. Contractions to angiotensin II (AII), big-endothelin and endothelin-1 (ET-1), but not KCl were decreased in TGR. Blockade of nitric oxide (NO)-synthase by L-NAME or removal of the endothelium did not alter these decreased contractions to ET-1 and AII in TGR, suggesting that receptors or signaling pathways of these two agonists are downregulated during hypertension. Contractions to norepinephrine (NE) were also lower in TGR, however blockade of NO-synthase by L-NAME or removal of the endothelium evoked similar contractions to NE in both strains, suggesting that basal release of NO reduces contractions to NE to a greater extent in transgenic than control rats. In the presence of L-NAME, acetylcholine evoked endothelium-dependent contractions (EDCF) in TGR, which were blocked by the thromboxane/prostaglandin H2 receptor antagonists SQ 30741, and partially by the thromboxane synthase inhibitor CGS 13080, suggesting that prostaglandin H2 is the mediator. Endothelium-dependent relaxation to acetylcholine was decreased in TGR, while endothelium-independent relaxations to sodium nitroprusside were similar in both strains. SQ 30741 did not improve relaxations to acetylcholine in TGR indicating that impaired relaxations to acetylcholine are due to a decreased acetylcholine-receptor mediated release of NO rather than increased release of EDCF. Thus, Ren-2 hypertension leads to marked alterations of vascular functions in the aorta. These changes could contribute to hypertension and its vascular complications in TGR(mRen2)27 rats.


Subject(s)
Aorta/physiopathology , Endothelium, Vascular/physiopathology , Hypertension/physiopathology , Renin/metabolism , Acetylcholine/pharmacology , Angiotensin II/pharmacology , Animals , Animals, Genetically Modified , Aorta/drug effects , Blood Pressure , Body Weight , Endothelin-1/pharmacology , Endothelins/pharmacology , Hypertension/genetics , Hypertension/metabolism , Male , Mice , Muscle Contraction/drug effects , Muscle Contraction/physiology , Muscle Relaxation/drug effects , Muscle Relaxation/physiology , Muscle, Smooth, Vascular/drug effects , Muscle, Smooth, Vascular/physiopathology , NG-Nitroarginine Methyl Ester/pharmacology , Norepinephrine/pharmacology , Protein Precursors/pharmacology , Rats , Rats, Sprague-Dawley , Renin/genetics
7.
Croat Med J ; 40(1): 77-9, 1999 Mar.
Article in English | MEDLINE | ID: mdl-9933900

ABSTRACT

The calculation of the heart axis in the frontal plane can be performed with the combination of any two leads. The use of combination of bipolar (I, II, III) and unipolar leads (aVR, aVL and aVF) can produce wrong results. Calculation of the electrical axis from leads I and aVF without correction (sometimes used in ECG recorders): EA= Arctan (aVF/I) results in lower values (in our study: 34 4 , n = 48) as compared to the values obtained with formula that uses leads I and II: EA= Arctan ((2*II-I)/(Sqr(3)*I)) (axis = 33+/-7 degrees, n=48; p<0.005, paired t-test with Bonferroni correction) or with corrected formula which uses leads I and aVF: EA=+/-Arctan ((2*aVF)/(Sqr(3)*I)) (axis = 374 degrees, n=48; p<0.005, paired t-test with Bonferroni correction). The correction factor 2/Sqr(3) is required because the unipolar and bipolar leads have different strengths. Although the difference rarely reach clinical significance, our results suggests that the ECG recorders should be proofed on formulas used for the calculation of the electrical axis.


Subject(s)
Electrocardiography/methods , Signal Processing, Computer-Assisted , Humans
8.
J Cardiovasc Pharmacol ; 24(6): 979-85, 1994 Dec.
Article in English | MEDLINE | ID: mdl-7898083

ABSTRACT

The effects of chronic therapy with the angiotensin-converting enzyme (ACE) inhibitor trandolapril and/or Ca2+ antagonist verapamil on endothelial and vascular smooth muscle (VSM) function were studied in spontaneously hypertensive, stroke-prone rats (SHRSP). Dosages decreasing systolic blood pressure (SBP) by 20% were administered orally (p.o.) by gavage as monotherapy or combination therapy for 8 weeks, beginning at age 6 weeks. Combination therapy dosages were the same as those used in monotherapy (trandolapril 0.7 mg/kg/day verapamil 20 mg/kg/day) in one group; the second group received only half the monotherapy dosage. The study was placebo-controlled and performed in parallel groups. Isometric tension was measured in aortic rings suspended in organ chambers (95% C2/5% CO2; 37 degrees C). SBP decreased in all groups, as compared with placebo [30-47 mm Hg, analysis of variance (ANOVA), p < 0.05], but decrease was more pronounced in rats receiving high-dose combination (76 mm Hg, ANOVA, p < 0.05). In norepinephrine (NE)-contracted rings, endothelium-dependent relaxation to acetylcholine (ACh) was augmented similarly with all forms of therapy (maximal relaxations 89-94%) as compared with placebo (64 +/- 6%, p < 0.05). In contrast, the response to sodium nitroprusside (SNP) was similar in all groups (NS). In quiescent rings, ACh elicited endothelium-dependent contractions (in the presence of N omega-monomethyl-L-arginine, L-NAME) that were not affected by therapy.(ABSTRACT TRUNCATED AT 250 WORDS)


Subject(s)
Angiotensin-Converting Enzyme Inhibitors/therapeutic use , Cerebrovascular Disorders/prevention & control , Endothelium, Vascular/drug effects , Hypertension/drug therapy , Indoles/therapeutic use , Verapamil/therapeutic use , Administration, Oral , Angiotensin-Converting Enzyme Inhibitors/administration & dosage , Animals , Body Weight/drug effects , Drug Administration Schedule , Drug Therapy, Combination , Indoles/administration & dosage , Male , Muscle Contraction/drug effects , Nitric Oxide/metabolism , Norepinephrine/pharmacology , Rats , Rats, Inbred SHR , Verapamil/administration & dosage
9.
J Cardiovasc Pharmacol ; 23(6): 916-21, 1994 Jun.
Article in English | MEDLINE | ID: mdl-7523783

ABSTRACT

Neurohumoral changes influencing peripheral vascular resistance play a major role in congestive heart failure (CHF). We studied vascular function in 1-year-old cardiomyopathic syrian hamsters with pulmonary congestion and age-matched control hamsters. Aorta and mesenteric resistance arteries were suspended in organ chambers and myographs, respectively, for isometric tension recording. In aorta and mesenteric resistance arteries, contractile responses to norepinephrine (NE) were comparable in cardiomyopathic hamsters and controls. After inhibition of nitric oxide (NO) formation with nitro-L-arginine methylester (L-NAME), contractions to NE were enhanced in aorta of cardiomyopathic hamsters (p < 0.05); no effect was noted in controls or mesenteric resistance arteries. Low doses of endothelin-1 (ET-1 10(-10)-10(-9) M) caused stronger contractions in aorta of cardiomyopathic hamsters as compared with controls (p < 0.05). The sensitivity and maximal contraction to ET were more pronounced in mesenteric resistance arteries as compared with aorta in both cardiomyopathic and control hamsters (p < 0.05-0.001). In both aorta and mesenteric resistance arteries, acetylcholine (ACh 10(-9)-10(-5) M) induced concentration-dependent relaxation, which was prevented by L-NAME (p < 0.001). Maximal endothelium-dependent relaxation was more pronounced in aorta of cardiomyopathic hamsters (p < 0.05), but not different in mesenteric resistance arteries.(ABSTRACT TRUNCATED AT 250 WORDS)


Subject(s)
Arginine/physiology , Endothelins/pharmacology , Heart Failure/metabolism , Heart Failure/physiopathology , Nitric Oxide/physiology , Acetylcholine/pharmacology , Animals , Aorta/drug effects , Aorta/physiology , Arginine/analogs & derivatives , Arginine/metabolism , Arginine/pharmacology , Body Weight/physiology , Cricetinae , Disease Models, Animal , Endothelium, Vascular/drug effects , Endothelium, Vascular/physiology , In Vitro Techniques , Male , Mesenteric Arteries/drug effects , Mesenteric Arteries/physiology , Mesocricetus , Muscle Relaxation/drug effects , Myocardial Contraction/drug effects , NG-Nitroarginine Methyl Ester , Nitric Oxide/metabolism , Norepinephrine/pharmacology , Organ Size/physiology , Vascular Resistance/drug effects , Vascular Resistance/physiology
10.
Circulation ; 89(6): 2780-6, 1994 Jun.
Article in English | MEDLINE | ID: mdl-8205692

ABSTRACT

BACKGROUND: The renin-angiotensin system and endothelium-derived nitric oxide (EDNO) are important regulators of vascular tone. This study was designed to investigate endothelial and vascular smooth muscle function in coronary arteries of Ren-2 transgenic rats. METHODS AND RESULTS: Left anterior descending coronary arteries and aortas were isolated from transgenic rats and Sprague-Dawley control rats at 6 (young) and 12 (adult) weeks of age and examined in myographs or organ chambers for isometric tension recording. Systolic blood pressure was significantly higher in transgenic rats (young, 229 +/- 6 mm Hg; adult, 239 +/- 8 mm Hg) than in control rats (young, 126 +/- 2 mm Hg; adult, 118 +/- 3 mm Hg; P < .005). N omega-Nitro-L-arginine methyl ester (L-NAME, 10(-7) to 10(-4) mol/L) evoked marked endothelium-dependent contractions in coronary arteries (young, 52 +/- 8% of the contraction to 100 mmol/L KCl; adult, 40 +/- 8%) but not aortas (young, 3 +/- 1%; adult, 2 +/- 1%). In coronary arteries, this response was significantly smaller in adult (n = 9) than in young (n = 8, P < .05) control rats. Young transgenic rats (56 +/- 9%, n = 8) showed slightly stronger contractions in response to L-NAME than young control rats (NS), which almost totally disappeared in adult transgenic rats (6 +/- 3%, n = 7; P < .05 versus adult control rats; P < .01 versus young transgenic rats). Endothelium-dependent relaxations in response to acetylcholine (10(-9) to 10(-4) mol/L) were totally blocked by L-NAME (10(-4) mol/L) but were unaffected by the thromboxane receptor antagonist SQ30741 (10(-7) mol/L). This stimulated release of EDNO, endothelium-independent relaxations in response to the nitrovasodilator linsidomine (10(-9) to 10(-5) mol/L), and contractions in response to KCl (100 mmol/L) were comparable in all groups of rats. CONCLUSIONS: Ren-2 transgenic rats develop fulminant hypertension that is associated with a selective decrease in endothelium-dependent contractions in response to L-NAME, whereas endothelium-dependent relaxations in response to acetylcholine as well as smooth muscle function remain unaffected.


Subject(s)
Coronary Vessels/physiopathology , Endothelium, Vascular/physiology , Hypertension/physiopathology , Renin-Angiotensin System/physiology , Acetylcholine/pharmacology , Animals , Animals, Genetically Modified , Arginine/analogs & derivatives , Arginine/pharmacology , In Vitro Techniques , Molsidomine/analogs & derivatives , Molsidomine/pharmacology , Muscle, Smooth, Vascular/physiology , NG-Nitroarginine Methyl Ester , Nitric Oxide/physiology , Rats , Rats, Sprague-Dawley
11.
Circulation ; 89(5): 2212-8, 1994 May.
Article in English | MEDLINE | ID: mdl-8181147

ABSTRACT

BACKGROUND: Coronary artery disease is an important complication of hypertension. Therefore, the effects of antihypertensive therapy on the endothelial nitric oxide (NO)/L-arginine pathway and vascular smooth muscle were studied in left anterior descending coronary arteries of Wistar-Kyoto (WKY) rats and spontaneously hypertensive rats (SHR). Angiotensin II (AT1) receptor antagonists CGP 48369 and valsartan, angiotensin-converting enzyme inhibitor benazepril HCl, and calcium antagonist nifedipine were used as antihypertensive agents. METHODS AND RESULTS: Rings were examined in myograph systems for isometric tension recording. In untreated WKY and SHR rings, acetylcholine (10(-9) to 10(-5) mol/L) but not bradykinin, substance P (both 10(-6) mol/L), or thrombin (1 U/mL) induced comparable endothelium-dependent relaxations. These relaxations were markedly decreased by NG-monomethyl-L-arginine (10(-4) mol/L) and fully prevented by N omega-nitro-L-arginine methyl ester (10(-4) mol/L) or methylene blue (10(-5) mol/L). In vitro treatment of WKY and SHR rings with benazeprilat, CGP 48369, or valsartan (3 x 10(-7) mol/L) did not affect responses to acetylcholine. In SHR, chronic therapy for 8 weeks with benazepril HCl, CGP 48369, valsartan, or nifedipine (each 10 mg.kg-1.d-1 PO) similarly reduced blood pressure and increased endothelium-dependent relaxations to acetylcholine (log shift at IC50, ie, half-maximal inhibition of a preceding contraction, 10-, 8-, 13-, and 13-fold, P < .05 versus control), whereas relaxations to the NO donor 3-morpholino sydnonimine (SIN-1, 10(-9) to 10(-5) mol/L) remained unaffected. In WKY, chronic therapy with nifedipine (10 mg.kg-1.d-1 PO) affected neither blood pressure nor relaxations to acetylcholine or SIN-1. CONCLUSIONS: In rat coronary arteries, NO is synthesized via the endothelial L-arginine pathway and released after stimulation with acetylcholine. In SHR, chronic antihypertensive therapy with either angiotensin receptor antagonists, an angiotensin-converting enzyme inhibitor, or a calcium antagonist specifically increased the normal endothelium-dependent relaxations to acetylcholine, probably because of their blood pressure-lowering effects, whereas the responsiveness of vascular smooth muscle to NO remained unaffected.


Subject(s)
Antihypertensive Agents/therapeutic use , Coronary Vessels/drug effects , Endothelium, Vascular/drug effects , Hypertension/drug therapy , Muscle, Smooth, Vascular/drug effects , Pyrimidines , Angiotensin Receptor Antagonists , Animals , Arginine/physiology , Coronary Vessels/physiology , Hypertension/physiopathology , Nitric Oxide/physiology , Rats , Rats, Inbred SHR , Rats, Inbred WKY , Tetrazoles/therapeutic use , Valine/analogs & derivatives , Valine/therapeutic use , Valsartan
12.
J Cardiovasc Pharmacol ; 22(3): 499-505, 1993 Sep.
Article in English | MEDLINE | ID: mdl-7504144

ABSTRACT

Tropisetron (ICS 205-930) is a novel drug that blocks serotonin (5-HT3) receptors and, at higher concentrations, potassium channels. Programmed electrical stimulation (PES) and tracer microspheres were used to investigate antiarrhythmic, systemic, and regional hemodynamic effects in anesthetized rabbits. Tropisetron (0.3, 1, and 3 mg/kg intravenously, i.v.) dose-dependently increased the effective refractory period (ERP) to a first and similarly to a second extrastimulus. The arrhythmias elicited by PES with one and two extrastimuli were suppressed dose dependently. The same doses and a higher dose (6 mg/kg i.v.) were tested for systemic, especially cardiodepressant, and regional hemodynamic activity in a second series of experiments. Doses < or = 3 mg/kg were almost devoid of systemic hemodynamic activity and did not alter the ECG. At the highest dose used (6 mg/kg), cardiodepression caused a decrease in blood pressure (BP), cardiac output (CO), and heart rate (HR) and an increase in central venous pressure (CVP). A selective increase in gastric blood flow was observed, starting at the lowest dose used. The highest cardiodepressant dose reversed this increase and decreased regional myocardial blood flow, especially to the subendocardial layer of the left ventricle, probably by lowering myocardial oxygen consumption. Antiarrhythmic effects thus start at 0.3 mg/kg, and doses < or = 3 mg/kg i.v. did not elicit hemodynamic side effects.


Subject(s)
Anti-Arrhythmia Agents/pharmacology , Blood Pressure/drug effects , Cardiac Output/drug effects , Heart Rate/drug effects , Indoles/pharmacology , Animals , Dose-Response Relationship, Drug , Electric Stimulation , Indoles/administration & dosage , Injections, Intravenous , Microspheres , Oxygen Consumption/drug effects , Rabbits , Tropisetron
13.
J Cardiovasc Pharmacol ; 21(6): 937-46, 1993 Jun.
Article in English | MEDLINE | ID: mdl-7687720

ABSTRACT

Structural alterations after myocardial infarction (MI) in rats are usually examined only after death of the experimental animal. Magnetic resonance imaging (MRI) allows repeated and noninvasive measurements of important structural [left ventricular (LV) mass, LV wall thickness, LV chamber radius] as well as function [LV end-systolic and LV end-diastolic volume, stroke volume (SV), ejection fraction (EF)] parameters for a prolonged period. We describe our experience in a series of experiments in rats. Three weeks after MI, infarct size (IS) was determined by MRI and the rats were divided into two groups with equal IS. Three weeks later, treatment with the angiotensin-converting enzyme (ACE) inhibitor spirapril (10 mg/kg in food) or placebo was started. In both groups, the first MRI scan taken before the treatment showed moderately dilated left ventricles and signs of impaired LV function, i.e., an increase in LV end-systolic and end-diastolic volume and decreased EF. After 3-week treatment, no significant differences with respect to heart structure and function were detected as compared with those of untreated animals. Prolonged treatment for 10 weeks with spirapril resulted in significant reduction of LV dilatation, LV mass, and LV end-systolic and end-diastolic volume, which was accompanied by improved EF. Hemodynamic examinations after treatment for 6 months showed, in contrast to control animals, no increase in right ventricular systolic pressure in animals receiving spirapril. Furthermore, histologic examination of perfusion-fixed hearts at the end of the study demonstrated more pronounced LV dilatation in control animals, thus confirming the in vivo MRI data. Delayed treatment with spirapril proved to have beneficial effects on structure and function of infarcted hearts within 10 weeks. Spirapril limited LV dilatation, reduced LV weight and LV end-systolic and end-diastolic volumes, and improved EF.


Subject(s)
Angiotensin-Converting Enzyme Inhibitors/pharmacology , Enalapril/analogs & derivatives , Myocardial Infarction/pathology , Angiotensin-Converting Enzyme Inhibitors/pharmacokinetics , Animals , Blood Pressure/drug effects , Body Weight/drug effects , Enalapril/pharmacokinetics , Enalapril/pharmacology , Hemodynamics/drug effects , Image Processing, Computer-Assisted , Magnetic Resonance Imaging , Male , Myocardial Infarction/physiopathology , Peptidyl-Dipeptidase A/blood , Perfusion , Rats , Rats, Wistar , Stroke Volume/physiology , Ventricular Function, Left/drug effects
14.
J Cardiovasc Pharmacol ; 21(6): 967-72, 1993 Jun.
Article in English | MEDLINE | ID: mdl-7687724

ABSTRACT

Among antiarrhythmic agents, those belonging to class III are considered most promising. Class III drugs act by prolonging the action potential duration (APD), which increases the effective refractory period (ERP). This effect can be achieved by several different cellular mechanisms. We hypothesized that among other variables the mechanism of action could be important for the propensity of class III agents to have proarrhythmic effects. We investigated the effects of sotalol (a potassium channel blocker) and DPI 201-106 (DPI, an activator of sodium channels) at doses causing the same increase in ERP, using programmed electrical stimulation (PES) in open-chest rabbits. After baseline measurements, three cumulative doses of DPI (0.3, 1, and 3 mg/kg) or sotalol (0.1, 0.3, and 1 mg/kg) or vehicle (placebo) were infused. Before drug administration, PES elicited arrhythmias in 11 of 21 animals. These arrhythmias remained unchanged in the placebo group and decreased dose dependently with sotalol. DPI, however, increased the inducibility of arrhythmias in all animals at the third dose. The two agents differed with respect to their effect on ERP2, measured with a second extrastimulus. In contrast to ERP1, which was prolonged to the same extent by both drugs, ERP2 was prolonged more by sotalol than by DPI. Proarrhythmic effects of sotalol could not be shown in this model. Our results suggest that the cellular mechanism that causes the class III effect is an important factor with respect to the occurrence of proarrhythmic activity.


Subject(s)
Arrhythmias, Cardiac/chemically induced , Piperazines/pharmacology , Sotalol/pharmacology , Animals , Arrhythmias, Cardiac/physiopathology , Blood Pressure/drug effects , Dose-Response Relationship, Drug , Electric Stimulation , Heart Rate/drug effects , Rabbits , Refractory Period, Electrophysiological/drug effects
15.
J Pharmacol Toxicol Methods ; 28(2): 73-7, 1992 Sep.
Article in English | MEDLINE | ID: mdl-1482788

ABSTRACT

Dimension measurements of the right ventricle are difficult to obtain because of its complex geometry, thus we evaluated a method of right ventricular dimension measurements. Crystals were placed on the ventral and dorsal side of the right ventricular free wall, approximately one-fourth of the right ventricular semicircle away from the septum, in the middle of a cranio-caudal axis of the ventricles. The effects of an increased (infusion of 20 mL/kg of 5% glucose for 3 min into seven rabbits), as well as decreased preload (nitroglycerin, 5 micrograms/kg/min i.v. n = 6) were measured and compared with changes during a placebo infusion (n = 6). The change in shortening of the right ventricle wall segment correlated with changes in both atrial natriuretic factor (ANF) plasma concentration (r = 0.89, p < 0.05) and central venous pressure (CVP) (r = 0.94, p < 0.05), respectively. Both these variables are influenced by right ventricular function and dimensions in healthy animals. Dimension measurements obtained across the free wall of the right ventricle appear to reflect right ventricular function well and should be useful in assessing the effects of drugs intended for the treatment of angina pectoris or heart failure.


Subject(s)
Heart Ventricles/diagnostic imaging , Ventricular Function, Right/physiology , Animals , Atrial Natriuretic Factor/blood , Central Venous Pressure/physiology , Hemodynamics , Male , Placebos , Rabbits , Ultrasonography/methods , Ventricular Function, Right/drug effects
16.
J Cardiovasc Pharmacol ; 20(1): 125-30, 1992 Jul.
Article in English | MEDLINE | ID: mdl-1383621

ABSTRACT

Blunted cardiac responses to sympathetic and vagal activation are key features of heart failure. Since the modulation of drug effects by a selective autonomic dysfunction is little known, we developed an acute rabbit model imitating these defects. Anesthetized rabbits were subject to cervical vagotomy and propranolol (1 mg/kg i.v.) pretreatment, thus eliminating vagally and sympathetically mediated cardiac responses, while maintaining the responsiveness of the peripheral circulation to these reflexes ("V-B" animals). Responses to drugs were altered in V-B compared with normal animals: Ouabain (5-50 micrograms/kg) increased myocardial contractile force more and milrinone (30-300 micrograms/kg) less, yet it increased the heart rate more; the reflex tachycardia to nitroprusside (1-10 micrograms/kg/min) was blunted and spirapril (0.1 and 1 mg/kg, all i.v.) decreased the central venous pressure only in V-B animals. Several drug effects were thus strongly modulated by autonomic dysfunction and responses of V-B animals were closer to those of heart failure patients than the responses of the normal animals, especially for milrinone.


Subject(s)
Autonomic Nervous System/physiopathology , Cardiovascular Agents/pharmacology , Heart Failure/drug therapy , Heart Rate/drug effects , Myocardial Contraction/drug effects , Animals , Cardiovascular Agents/therapeutic use , Disease Models, Animal , Enalapril/analogs & derivatives , Enalapril/pharmacology , Heart Failure/physiopathology , Milrinone , Nitroprusside/pharmacology , Ouabain/pharmacology , Propranolol/pharmacology , Pyridones/pharmacology , Rabbits , Vagotomy , Vasodilator Agents/pharmacology
17.
J Cardiovasc Pharmacol ; 19(3): 375-81, 1992 Mar.
Article in English | MEDLINE | ID: mdl-1378117

ABSTRACT

The effect of the angiotensin-converting enzyme (ACE) inhibitor spirapril on structural and functional parameters of volume-overloaded rat hearts was evaluated in a time-course study. Left ventricular hypertrophy (LVH) was induced by graded disruption of the aortic valve in male Wistar rats. Four weeks later, structural (LV mass and LV wall thickness) as well as functional parameters [LV end-systolic and end-diastolic volumes, stroke volume (SV), ejection fraction (EF)] were determined in anesthetized animals by magnetic resonance imaging (MRI). The rats were then divided into two groups, one of them receiving spirapril (10 mg/kg/day) in food. LV parameters were evaluated by MRI at 4, 18, 25, and 32 days after treatment was started. MRI analysis before the start of treatment showed that both groups had developed a similar degree of eccentric LV hypertrophy. Similarly, LV wall thickness, end-systolic and end-diastolic volumes, SV, and EF did not differ between the groups. Treatment with spirapril resulted in stable LV weight during the follow-up period of 32 days, whereas the untreated group showed a significant steady increase in heart weight. LV end-diastolic volume, LV end-systolic volume, and SV were smaller in the spirapril group when measured after 25 and 32 days, but only the difference in end-diastolic volume reached statistical significance. LV wall thickness and EF were not affected by spirapril. After the last MRI determinations, blood pressure (BP) and the response to angiotensin I (ANGI) were measured in conscious animals. Systolic BP (SBP) and mean arterial pressure (MAP) were significantly lower in spirapril-treated rats, and the dose-response curve to ANGI was shifted to the right.(ABSTRACT TRUNCATED AT 250 WORDS)


Subject(s)
Angiotensin-Converting Enzyme Inhibitors/therapeutic use , Cardiomegaly/prevention & control , Enalapril/analogs & derivatives , Animals , Blood Pressure/drug effects , Enalapril/therapeutic use , Heart Ventricles/anatomy & histology , Magnetic Resonance Imaging , Male , Rats , Rats, Inbred Strains , Stroke Volume/drug effects , Ventricular Function, Left/drug effects
18.
Plucne Bolesti ; 42(1-2): 113-5, 1990.
Article in Croatian | MEDLINE | ID: mdl-2217621

ABSTRACT

A computer program for analysing the parameters of the acid-base status and respiratory gases has been designed. The program separates cases which are included into classical picture of certain respiratory, metabolic and mixed disorders. Out of a test series of 200 findings, 93% findings have been accurately interpreted. The program is written in BASIC, translated into machine code and occupies about 25 Kbyte computer memory. The main parts of the program use commands which do not favorize any version of BASIC increasing the program portability to other systems. The classification of respiratory gases and acid-base status was based on the already known facts.


Subject(s)
Acid-Base Equilibrium , Blood Gas Analysis , Diagnosis, Computer-Assisted , Acid-Base Imbalance/diagnosis , Humans , Respiration Disorders/diagnosis
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