PubMed Health⌕ Search

Biomedical subjects

A M Perna

Publications and source records attributed to A M Perna.

At least 19 recordsLinked to original sources
PubMed2005

Cardiac volume overload rapidly induces oxidative stress-mediated myocyte apoptosis and hypertrophy.

Oxidative stress stimulates both growth and apoptosis in cardiac myocytes in vitro. We investigated the role of oxidative stress in the initial phases of cardiac remodeling induced in an animal model by volume overload. As plausible candidates for a connection between oxidative stress and cardiomyocyte apoptosis or hypertrophy, we explored the behaviour of two MAPKs, specifically JNK and ERK. At 48 h of overload, the greatest increase in oxidative stress coincided with a peak of cardiomyocyte apoptosis. This was possibly induced through the mitochondrial metabolism, as evidenced by the release of cytochrome c and a significant increase in the active forms of caspase-9 and -3, but not caspase-8. Oxidative stress markers significantly decreased at 96 h of overload, combined with a marked attenuation of apoptosis and the appearance of hypertrophy. The highest levels of JNK and the lowest levels of ERK phosphorylation were observed at 48 h of overload. Conversely, a sharp increase in ERK phosphorylation was detected at 96 h of overload coinciding with the hypertrophic response. Together these results show that oxidative stress is an early and transient event in myocardial volume overload. They suggest that oxidative stress mediates amplitude dependent apoptotic and hypertrophic responses in cardiomyocytes through the selective activation of, respectively, JNK and ERK.

Animals↗
PubMed2004

Behavioral effects of serotonin and serotonin agonists in two crayfish species, Procambarus clarkii and Orconectes rusticus.

Exogenous serotonin elicits several behaviors in Procambarus clarkii, including a flexed, elevated posture, reduced locomotion, and changes in aggressive behavior. We conducted experiments to determine if several serotonin agonists mimicked the behavioral effects of serotonin in two crayfish species, P. clarkii and Orconectes rusticus. Drugs tested were 1-(3-Chlorophenyl)-piperazine dihydrochloride (mCPP), Oxymetazoline, 2,5-dimethoxy-4-iodoamphetamine (DOI), CGS-12066A, and (+/-)-8-hydroxy-2-(di-n-dipropylamino) tetralin (8-OH-DPAT). In P. clarkii, mCPP most closely mimicked the effects of serotonin, significantly increasing the performance of the flexed, elevated posture and reducing locomotion; 8-OH-DPAT significantly reduced locomotion as well. Both of these drugs produced significant increases in elevated posture and decreases in locomotion in O. rusticus, and in this species, the drugs at test concentrations were more effective in eliciting these effects than serotonin. The effects of the drugs on behaviors performed during fighting bouts were variable. In both species, only 8-OH-DPAT significantly reduced several agonistic behaviors, and no agonist or 5-HT itself produced significant increases in agonistic behavior.

Animals↗
PubMed2003

Possible role of acylphosphatase, Bcl-2 and Fas/Fas-L system in the early changes of cardiac remodeling induced by volume overload.

To identify early adaptive processes of cardiac remodeling (CR) in response to volume overload, we investigated the molecular events that may link intracellular Ca(2+) homeostasis alterations and cardiomyocyte apoptosis. In swine heart subjected to aorto-cava shunt for 6, 12, 24, 48 and 96 h sarcoplasmic reticulum (SR) Ca(2+) pump activity was reduced until 48 h (-30%), but a recovery of control values was found at 96 h. The decrease in SR Ca(2+)-ATPase (SERCA2a) expression at 48 h, was more marked (-60%) and not relieved by a subsequent recovery, while phospholamban (PLB) concentration and phosphorylation were unchanged at all the considered times. Conversely, acylphosphatase activity and expression significantly increased from 48 to 96 h (+40%). Bcl-2 expression increased significantly from 6 to 24 h, but at 48 h, returned to control values. At 48 h, microscopic observations showed that overloaded myocardium underwent substantial damage and apoptotic cell death in concomitance with an enhanced Fas/Fas-L expression. At 96 h, apoptosis appeared attenuated, while Fas/Fas-L expression was still higher than control values and cardiomyocyte hypertrophy became to develop. These data suggest that in our experimental model, acylphosphatase could be involved in the recovery of SERCA2a activity, while cardiomyocyte apoptosis might be triggered by a decline in Bcl-2 expression and a concomitant activation of Fas.

Acid Anhydride Hydrolases↗
PubMed2003

Altered Cx43 expression during myocardial adaptation to acute and chronic volume overloading.

Gap-junctions are specialized regions of intercellular contacts allowing electrical impulse propagation among adjacent cardiomyocytes. Connexin43 (Cx43) is the predominant gap-junction protein in the working ventricular myocardium and its reduced expression has been extensively implicated in the genesis of conduction abnormalities and re-entry arrhythmia of chronically hypertrophied hearts. In contrast, data on the role played by this protein during cardiac remodeling and early phases of developing hypertrophy are lacking. Therefore, in the present study, we investigated this issue using an experimental model of pig left ventricle (LV) volume overloading consisting in the creation of an aorto-cava fistula. At scheduled times (6, 24, 48, 96, 168 h, and 2, 3 months after surgery) echocardiographic and haemodynamic measurements were performed and myocardial biopsies were taken for the morphological and biochemical analyses. When faced with the increased load, pig myocardium underwent an initial period (from 6 up to 48 h) of remarkable tissue remodeling consisting in the occurrence of cardiomyocyte damage and apoptosis. After that time, the tissue developed a hypertrophic response that was associated with early dynamic changes (up-regulation) in Cx43 protein expression, as demonstrated by Western blot and confocal immunofluorescence analyses. However, an initial transient increase of this protein was also found after 6 h from surgery. With the progression of LV hypertrophy (from 168 hr up to 3 months), a reduction in the myocardial Cx43 expression was, instead, observed. The increased expression of Cx43 protein during acute hypertrophic response was associated with a corresponding increase in the levels of its specific mRNA, as detected by RT-PCR. We concluded that up-regulation of Cx43 gap-junction protein could represent an immediate compensatory response to support the new working conditions in the early stages of ventricular overloading.

Adaptation, Physiological↗
PubMed2002

Biochemical changes and their relationship with morphological and functional findings in pig heart subjected to lasting volume overload: a possible role of acylphosphatase in the regulation of sarcoplasmic reticulum calcium pump.

We evaluated the changes in sarcoplasmic reticulum (SR) function and the parallel hemodynamic and morphological modifications in a heart subjected to volume overload. We also determined the levels of acylphosphatase, a cytosolic enzyme, that could play a regulatory effect on SR Ca(2+) pump by hydrolyzing the phosphorylated intermediate of this transport system. For this, swine hearts were subjected to volume overload by aorta-cava shunt for 1, 2, or 3 months. Changes in heart contractility reflected modifications of SR function, whose reduction after 1 month of overload was followed by a gradual recovery. A decrease in SERCA2a protein and mRNA content was shown from 1 month and remained for the following 2 months. Phospholamban content and its phosphorylation status were not modified. Acylphosphatase was unchanged at 1 month, but at 2 months this enzyme exhibited an increased activity, protein and mRNA expression. Morphological alterations consisting of the cytoskeletal architectures, intermyofibrillar oedema, swollen mitochondria and abnormality of the membrane system (T-tubule and SR cisternae) were particularly evident after 1 month but almost disappeared after 3 months. These results suggest that our overloaded hearts underwent a substantial recovery of their structural and biochemical properties at 3 months after surgery. A possible involvement of acylphosphatase in the modification of SR function is discussed.

Acid Anhydride Hydrolases↗
PubMed2001

Clinically relevant cognitive impairment after cardiac surgery: a 6-month follow-up study.

BACKGROUND AND PURPOSE: The majority of studies on neuropsychological complications after cardiac surgery used the raw variation of selective tests scores to define the occurrence of cognitive decline. We prospectively estimated the frequency of cognitive impairment after cardiac surgery, with a particular emphasis on persistent and clinically relevant cognitive decline. Possible baseline and operative predictors were also evaluated. METHODS: An extensive neuropsychological battery was administered to 110 patients (mean age 64.1+/-9.4 years; 70.9% males) undergoing cardiac surgery before and 6 months after the operation. After evaluating the variations in the cognitive performances, two independent neuropsychologists ranked the patients as unchanged-improved, mildly-moderately deteriorated, or severely deteriorated, using a global and functionally oriented judgement. The degree of the impairment was determined in relation to its impact on everyday life activities. RESULTS: Ten patients (9.1%) were ranked as severely deteriorated, 22 (20%) as mildly-moderately deteriorated, and 78 (70.9%) as unchanged-improved. Cognitively impaired patients were older (p=0.031), more often females (p=0.005), with a low education level (p=0.013). At multivariate analysis, female gender (odds ratio (OR) 6.14, 95% confidence interval (95% CI) 2.16-17.50), baseline use of beta-blockers (OR 4.55, 95% CI 1.30-15.92), and PaO2 at arrival in intensive care unit (OR for 1 mm Hg increment 1.012, 95% CI 1.004-1.020) were significant predictors of cognitive impairment of any degree. Positive predictors of severe cognitive impairment were history of hypertension (OR 5.33, 95% CI 1.03-27.64) and PaO2 at arrival intensive care unit (OR for 1 mm Hg increment 1.020, 95% CI 1.006-1.035), while education was protective (OR per year of increment 0.53, 95% CI 0.31-0.90). CONCLUSIONS: A considerable proportion of cardiac surgery patients may undergo clinically relevant cognitive impairment. The knowledge of variables influencing cognitive outcome is essential for the adoption of preventive measures.

Adult↗
PubMed2001

Are macrophages involved in early myocardial reperfusion injury?

BACKGROUND: Neutrophils are the predominant phagocytes in the early stages of myocardial ischemia-reperfusion response and are also implicated in the development of tissue damage. This study examined the role of recruited macrophages in the evolution of this tissue injury. METHODS: Farm pigs were subjected to 30 minutes of myocardial ischemia followed by 30 minutes of reperfusion. Biopsy samples were taken from the control, ischemic, and ischemic-reperfused left ventricle wall and processed for both morphologic and biochemical analyses. In situ production of tumor necrosis factor-alpha was evaluated by Western blot and immunofluorescence. A full hemodynamic evaluation was also performed. RESULTS: Myocardial ischemia and early reperfusion caused marked neutrophil and macrophage tissue accumulation and tumor necrosis factor-alpha production by the injured tissue. Immunofluorescence studies allowed us to localize tumor necrosis factor-alpha predominantly in tissue-infiltrating macrophages. No depression in the global myocardial contractile function was observed, either during ischemia or after reperfusion. CONCLUSIONS: These data suggest that the newly recruited macrophages within the ischemic and early post-ischemic myocardium may play a role in promoting neutrophil tissue infiltration and subsequent neutrophil-induced tissue dysfunction by producing tumor necrosis factor-alpha.

Animals↗
PubMed2001

Intramural hematoma of the aorta: diagnosis and treatment.

OBJECTIVE: Increasing use of modern high-resolution imaging techniques yields to describe very early stages of aortic pathology which, if left untreated, may lead to overt aortic dissection. One typical example is aortic intramural hematoma (IMH) with a limited number of cases described in the literature and uncertainties still existing about the most appropriate treatment. Purpose of our study is to report our experience in the evaluation and treatment of IMHs. METHODS: From 1991 to 1999 175 patients were conveyed to our centre for aortic dissection; in nine of them diagnosis of acute IMH was performed. RESULTS: Diagnosis was obtained by means of conventional CT scan of the chest. All the patients underwent surgery, one patient died (11%). At the follow-up (mean 31 months) eight patients were alive and well and did not require any other cardiac surgery. CONCLUSIONS: The possibility to progress to overt aortic dissection may explain the need to an early diagnosis in the treatment of acute IMHs. Immediate surgical treatment is, in our experience, the preferred therapeutic option.

Aged↗
PubMed2000

Early changes induced in the left ventricle by pressure overload. An experimental study on swine heart.

The purpose of this study was to evaluate the early changes in sarcoplasmic reticulum (SR) function and the parallel morphological and hemodynamic modifications occurring in the heart following pressure overload. As regards SR function, we also explored the levels of acylphosphatase, an enzyme which might have a regulatory effect on the SR Ca(2+) pump by hydrolyzing the phosphorylated intermediate of this transport system. Pigs subjected to pressure overload by aortic stenosis for 6, 12, 24, 48, 72, and 96 h were compared to sham-operated controls. At each of the considered times both SR Ca(2+)-ATPase activity and Ca(2+) uptake, as well as acylphosphatase activity, were significantly enhanced in the pressure overloaded compared to the control hearts, with a maximal increase at 6 h; moreover, a positive and significant correlation was found between these parameters. The modifications in the activities of Ca(2+)-ATPase and acylphosphatase reflected an increased expression of these proteins, while phospholamban did not show significant changes in its concentration nor in its phosphorylation status. As for hemodynamic parameters, rapid changes in the left ventricular function were observed and especially the early hours following the aortic stenosis appeared to be crucial for the adjustment of heart function. The most relevant morphological finding was a focal disarrangement of the myofibrillar pattern which was very evident at 6 h, and progressively attenuated at later times. Taken together our data suggest that an early adaptation to the increased hemodynamic working overload is a consistent activation of the contractile apparatus which reflects, at least in part, an enhanced SR function. Besides the changes in Ca(2+) pump protein expression, increased acylphosphatase levels might also contribute to this effect.

Animals↗
PubMed2000

Serological and virological evidence of non-sexual transmission of human herpesvirus type 8 (HHV8).

To evaluate whether or not human herpesvirus 8 (HHV8) can be transmitted through a non-sexual route a serological survey was carried out in a group of 51 catholic nuns. The seroprevalence rate and the geometrical mean antibody titre to anti-latent HHV8 antigen were similar in nuns and in a group of 60 women, matched by age, in the general population (27 vs. 24%; 1028 vs. 1575, respectively). Moreover, by using nested polymerase chain reaction (PCR), HHV8 DNA sequences were detected in 7 of 16 (43.8%) saliva and peripheral blood mononuclear cells (PBMC) from patients with classical Kaposi's sarcoma (KS) and in 3 out of 7 (42%) AIDS-KS patients. None of 5 HIV positive persons who did not have KS tested positive for HHV8 DNA. HHV8 DNA sequences were also detected in 2 of 12 (17%) saliva and 1 PBMC sample out of 12 healthy HHV8 positive individuals (age range: 30-80 years old). This paper suggests that non-sexual transmission of HHV8 is operating in our geographical setting and saliva may be a potential source of HHV8 spreading in the general population.

Adult↗
PubMed2000

Antibodies to human herpes virus type 8 (HHV8) in general population and in individuals at risk for sexually transmitted diseases in Western Sicily.

BACKGROUND: Human herpes virus 8 (HHV8) appears to be the primary aetiologic agent of Kaposi sarcoma (KS). To study the distribution of HHV8, a seroepidemiological study was carried out in western Sicily, where a high incidence rate of classical KS is well documented. METHODS: A total of 970 sera of healthy human immunodeficiency virus (HIV) negative individuals of general population (1-70 years old) and 742 sera of individuals in different risk groups for HIV infection were evaluated by means of an indirect immunofluorescence assay able to detect antibodies to lytic and latent HHV8 antigens. RESULTS: Crude seroprevalence to HHV8 antigens was 11.5% in the general population, and it increased significantly with age from 6% under age 16 to 22% after age 50. Significantly higher HHV8 seroprevalence rates were detected among HIV positive and negative homosexual men (62% and 22%, respectively), men who had sex with prostitutes (40% and 29%, respectively); female prostitutes (42% and 30%, respectively), and clients at a sexually transmitted disease clinic (male: 60% and 33%, respectively, female: 63% and 43%, respectively). In contrast, heterosexual intravenous drug users had seroprevalence rates comparable to those found in the general population. CONCLUSIONS: The results suggest that HHV8 infection is widespread in Western Sicily. The high seroprevalence in individuals with high risk sexual activity point to the role of sexual behaviour in the transmission of the infection in adults, whereas the detection of antibodies in younger population (under 16 years old) is suggestive of a non-sexual route of transmission, probably occurring during childhood by close personal contact.

Adolescent↗
PubMed1999

Inhibition of human immunodeficiency virus 1 (HIV-1) by variant B of human herpesvirus 6 (HHV-6).

Four HHV-6 strains were initially isolated during attempts to observe HIV-1 replication in cultured primary lymphocytes from 48 patients with AIDS. HHV-6 DNA from each strain was extracted from primary cell cultures and amplified using specific primers in a nested polymerase chain reaction (PCR) assay. All HHV-6 strains were classified as B variants by submitting the PCR products to the digestion of two restriction enzymes (Hind III and Bgl II). Since in primary cultures, the appearance of HHV-6 cytopathic effect was followed by a progressive reduction of HIV-1 replication, we tried to reproduce the observed inhibition in vitro. Two HHV-6 strains, used throughout the experiments, showed their ability to suppress HIV-1 replication when the viruses co-infected CD4+T lymphocyte cultures. While the intrinsic mechanism of this finding still remains unclear, the inhibition of HIV-1 replication was observed only when a high multiplicity of infection (m.o.i.) of HHV-6 and a low m.o.i. of HIV-1 were used in dually infected cell cultures. By using a semiquantitative determination of HIV-1 cDNA by PCR, it appears that the inhibition begins in infected cell cultures and, once established, does not allow any further HIV-1 replication.

Acquired Immunodeficiency Syndrome↗
PubMed1998

Distribution of hepatitis C virus genotypes among intravenous drug users. A ten-year study in Palermo, Sicily.

A cross-sectional study was carried out on the sera of 88 active intravenous drug users (IVDU) collected between 1985 and 1986 to evaluate the circulation of HCV genotypes in Western Sicily. The patients were grouped by age and classified by their HIV status. Genotype 3a (48.8% of all cases) was most frequently detected, followed by genotype 1a (20.4%) and type 1b (17.0%). No significant differences in HCV genotype distribution were observed between HIV positive and negative individuals. Next, the HCV genotype distribution found in sera samples of IDVUs drawn between 1985 and 1986 was studied and divided into three age groups. The genotype distribution in the younger group was then compared with samples collected ten years later, between 1995 and 1996, from young HIV negative IVDU individuals. A different distribution between HCV genotypes 3a and 1a was found with a relative, though not significant, increase in the detection of genotype 1a (38%). Finally, sera from six IVDUs obtained at three different times over a ten-year period were genotyped for HCV. None of the subjects showed any change in the genotype found at the first sampling throughout the ten years. The results suggest that a) genotype 1a and 3a are the most common among IVDUs in Western Sicily, b) concurrent HIV infection does not seem to influence HCV genotype and c) infected IVDUs harbor almost exclusively one genotype.

Adolescent↗
PubMed1997

Beneficial effects of the 21-aminosteroid U 74389G on the ischemia-reperfusion damage in pig hearts.

21-Aminosteroids (Lazaroids), acting as free radical scavengers and as membrane stabilizers, proved to have beneficial effects in various pathological conditions. In the present study we explored the effectiveness of one of these compounds, U 74389 G, in protecting pigs myocardium against the ischemia-reperfusion damage induced by transient coronary occlusion achieved by clampling the left anterior descending coronary artery. Animals were divided into three groups: control, untreated and treated. Control animals were operated but not subjected to ischemia-reperfusion; the untreated group underwent to ischemia-reperfusion without pharmacological treatment; while the treated group received the aminosteroid (4 mg/kg) before coronary occlusion and at the time of reperfusion. Specimens of myocardial tissue and blood samples were taken for morphological and biochemical studies. In the ischemic-reperfused myocardium of the untreated animals, the dominant morphological features were neutrophil infiltration, intercellular edema and severe swelling of mitochondria. All these alterations, notably neutrophil infiltration, were attenuated by aminosteroid treatment. As for the biochemical findings, the changes in adenine nucleotides and nucleosides levels, thus the reduction of energy charge, were reversed in the treated, but not in the untreated group. Myocardial concentration of malondialdehyde, which was undetectable in the control group, was raised in all the animals after reperfusion, but this effect was significantly less marked with aminosteroid treatment. In addition, the higher myocardial content of ascorbic acid and the reduced serum potential peroxidation exhibited by the treated animals compared with untreated group indicate an enhanced antioxidant protection induced by aminosteroid administration. On the other hand, the serum levels of myoglobin, cardiac troponin I and creatine kinase MB isoenzyme suggest the ability of the aminosteroid to attenuate the modifications of membrane permeability induced by ischemia-reperfusion injury. All these results lead to the conclusion that aminosteroid treatment, at least in the conditions of the present study, is effective in reducing the morphological and biochemical alterations occurring in ischemic-reperfused myocardium.

Adenosine Diphosphate↗
PubMed1997

Human herpesvirus type 8 DNA sequences in biological samples of HIV-positive and negative individuals in Sicily.

OBJECTIVE: To evaluate the circulation of a new human herpesvirus (HHV), HHV-8 or Kaposi's sarcoma (KS)-associated herpesvirus in a geographical area where a high incidence rate of classical KS was already present before the appearance of the AIDS epidemic. DESIGN AND METHODS: The study was carried out by analysing: (i) bioptic samples from classic, AIDS-associated KS, and controls; (ii) peripheral blood mononuclear cells (PBMC) from classic KS, HIV-positive subjects with and without KS and healthy HIV-negative individuals; (iii) semen samples from heterosexual HIV-positive and HIV-negative individuals affected or not by KS; and (iv) cervical swabs from HIV-negative healthy heterosexual females. All specimens were tested for the presence of HHV-8 DNA sequences by a two-step polymerase chain reaction. RESULTS: Positive results were obtained in 90% of bioptic samples of classic KS and in 100% of AIDS-associated KS. Viral sequences were also present in 50% of PBMC of subjects with classic KS and AIDS-associated KS, in 10% of AIDS patients without the angiosarcoma and in 11% of healthy HIV-negative individuals. Finally, HHV-8 DNA was detected in 13% of semen of HIV-negative heterosexual individuals and in 10% of AIDS patients without KS. Both PBMC and ejaculates from the same individual gave positive results. No HHV-8 sequences were found in cervical swabs. CONCLUSIONS: HHV-8 is widespread in the general population in Sicily since it was detected in PBMC and semen of heterosexual HIV-negative individuals and is not found only in high-risk groups. The viral load appears to be more elevated in a high-risk population and it may be ascribed to a viral reactivation. The higher incidence rates of KS in Sicily compared with northern Italy and other European countries might be related to the presence of HHV-8 in the general population.

AIDS-Related Opportunistic Infections↗
PubMed1996

Rare association of human herpesvirus 6 DNA with human papillomavirus DNA in cervical smears of women with normal and abnormal cytologies.

We investigated by nested PCR the possible association of human herpesvirus 6 (HHV-6) and human papillomavirus (HPV) genomes in the cervixes of 109 women with normal and abnormal cytological smears. HPV DNA was detected in 8.33% of 24 women with normal cytologies and in 41.1% of 85 women with abnormal cytologies; the proportion of HPV DNA was directly related to the severity of the lesions. HHV-6 DNA was found in only one patient, who had a cytological pattern of koilocytosis. The HHV-6 genome was classified by restriction enzyme analysis as variant B. The study indicates that detection of the HHV-6 genome in the cervixes of women with a wide spectrum of gynecological complaints is a rare event and rules out the possible association between HHV-6 and HPV genomes in cervical cancer lesions.

Adult↗