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C Viticchi

Publications and source records attributed to C Viticchi.

At least 19 recordsLinked to original sources
PubMed2003

Exploring the damage limitation possibilities of mineral fibres for future integrated solutions: an in vitro study.

Owing to their possible carcinogenic effect, asbestos and other silica derivatives have been identified as priority substances for risk reduction and prevention of pollution. Neutralisation procedures have thus become a topical research subject in many European and American countries. In the present study, silica derivatives (asbestos-containing and asbestos substitutes like slag wool, rock wool, cement asbestos) were fully impregnated with an epoxy resin according to the procedure used for the in situ impregnation with viscous polymeric media, which penetrate and cement the fibres in place and reduce the risk of their dispersion in air. Untreated and treated samples were used to investigate their in vitro interaction with a human continuous epithelial cell line (NCTC 2544 keratinocytes) and test the resin's efficiency in passivating the surface activity of the fibrous particulate. SEM and morpho-quantitative data evidenced that impregnation with the epoxy resin modifies the mineral fibres' bioactivity (reduction of cell adhesion and decreased spread/round cell ratio) and demonstrated the value of in vitro cell testing after passivation as a risk-assessment procedure. These tests could be used for the rapid determination of the level of passivation of new synthetic mineral fibrous materials subjected to resin impregnation.

Air Pollutants, Occupational↗
PubMed2001

Effect of mono-dose intraperitoneal cecropins in experimental septic shock.

OBJECTIVE: To investigate the efficacy of three cecropins, cecropin A, cecropin B, and cecropin P1, in preventing lethality in a rat model of septic shock. DESIGN: Prospective, randomized, controlled animal study. SETTING: Research laboratory in a university hospital. SUBJECTS: Adult male Wistar rats. INTERVENTIONS: Rats were given an intraperitoneal injection of 2 x 10(10) colony forming units of Escherichia coli, with the exception of the uninfected control group (C0). Animals were randomized to receive, immediately after bacterial challenge, intraperitoneally isotonic sodium chloride solution (untreated control group C1), 1 mg/kg cecropin A (group 2), 1 mg/kg cecropin B (group 3), 1 mg/kg cecropin P1 (group 4), 20 mg/kg imipenem (group 5), or 60 mg/kg piperacillin (group 6). Each group included 15 animals. MEASUREMENTS AND MAIN RESULTS: We measured bacterial growth (quantitative agar culture) in abdominal exudate and plasma, endotoxin and tumor necrosis factor-alpha concentration in plasma, and mortality. Results were evaluated at 48 hrs after inoculation. Cecropins, piperacillin, and imipenem significantly reduced the lethality and the number of E. coli in abdominal fluid compared with saline treatment. In addition, cecropin B significantly decreased the lethality compared with piperacillin treatment. Finally, only cecropins significantly reduced plasma endotoxin concentration. CONCLUSIONS: Mono-dose cecropin treatment prevents bacterial growth, endotoxemia, and mortality in rats with septic shock. Cecropin B was the most effective compound in reducing all variables measured.

Animals↗
PubMed2000

Do men and women follow different trajectories to reach extreme longevity? Italian Multicenter Study on Centenarians (IMUSCE).

Gender accounts for important differences in the incidence and prevalence of a variety of age-related diseases. Considering people of far advanced age, demographic data document a clear-cut prevalence of females compared to males, suggesting that sex-specific mortality rates follow different trajectories during aging. In the present investigation, we report data from a nationwide study on Italian centenarians (a total of 1162 subjects), and from two studies on centenarians living in two distinct zones of Italy, i.e., the island of Sardinia (a total of 222 subjects) and the Mantova province (Northern Italy) (a total of 43 subjects). The female/male ratio was about 2:1 in Sardinia, 4:1 in the whole of Italy, and about 7:1 in the Mantova province. Thus, a complex interaction of environmental, historical and genetic factors, differently characterizing the various parts of Italy, likely plays an important role in determining the gender-specific probability of achieving longevity. Gender differences in the health status of centenarians are also reported, and an innovative score method to classify long-lived people in different health categories, according to clinical and functional parameters, is proposed. Our data indicate that not only is this selected group of people, as a whole, highly heterogeneous, but also that a marked gender difference exists, since male centenarians are less heterogeneous and more healthy than female centenarians. Immunological factors regarding the age-related increase in pro-inflammatory status, and the frequency of HLA ancestral haplotypes also show gender differences that likely contribute to the different strategies that men and women seem to follow to achieve longevity. Concerning the different impact of genetic factors on the probability of reaching the extreme limits of the human life-span, emerging evidence (regarding mtDNA haplogroups, Thyrosine Hydroxilase, and IL-6 genes) suggests that female longevity is less dependent on genetics than male longevity, and that female centenarians likely exploited a healthier life-style and more favorable environmental conditions, owing to gender-specific cultural and anthropological characteristics of the Italian society in the last 100 years.

Aged↗
PubMed2000

Mupirocin prophylaxis against methicillin-susceptible, methicillin-resistant, or vancomycin-intermediate Staphylococcus epidermidis vascular-graft infection.

A rat model was used to investigate the efficacy of mupirocin in the prevention of vascular prosthetic graft infection due to Staphylococcus epidermidis strains with different susceptibility patterns (methicillin susceptible, methicillin resistant, and with intermediate resistance to vancomycin). The effect of mupirocin-soaked Dacron was compared to that of perioperative intraperitoneal prophylaxis with vancomycin. Graft infections were established in the back subcutaneous tissue of adult male Wistar rats by implantation of Dacron prostheses (1 cm(2)) followed by topical inoculation with 5 x 10(7) CFU of one staphylococcal strain. The study included a control group (no graft contamination), three contaminated groups that did not receive any antibiotic prophylaxis, three contaminated groups that received mupirocin-soaked grafts, three contaminated groups in which perioperative intraperitoneal vancomycin prophylaxis (10 mg/kg of body weight) was administered, and three contaminated groups that received mupirocin-soaked grafts and perioperative intraperitoneal vancomycin prophylaxis (10 mg/kg). The grafts were sterilely removed 7 days after implantation, and the infection was evaluated by using sonication and quantitative agar culture. Data analysis showed the efficacy of mupirocin against all three strains, with growth of the strains in treated rats significantly different than that in the untreated control. In addition, mupirocin was more effective than vancomycin against the strain with intermediate susceptibility to the glycopeptide. Finally, the combination of mupirocin and vancomycin produced complete suppression of the growth of all of the strains.

Aminoglycosides↗
PubMed1999

Contribution of zinc to reduce CD4+ risk factor for 'severe' infection relapse in aging: parallelism with HIV.

Aging and HIV have parallelism in immunodeficiency status because of the appearance of infections or relapse leading to death in both conditions. HIV-RNA is predictor for HIV progression correlated with CD4+ depletion. CD4+ and plasma zinc levels (zincaemia) may be predictors for infections relapse in aging because of zinc relevance for normal immune efficiency against infections and for CD4+ growth. Moreover, zincaemia decreases in aging and infection. A total of 67 elderly subjects affected by infections resistant to antibiotic therapy were recruited. A total of 28 HIV+ subjects with HAART therapy were also used. CD4+ depletion (507 mm3) and zincaemia deficiency (76 microg/dl), as compared to CD4+ (700-1100 mm3) and zincaemia (85-100 microg/dl; age 40-75 years) normal ranges, are possible limits (Cox hazard regression) for severe infections relapse, such as chronic obstructive bronchitis and bronchopneumonia by bacteria or Candida complication, in aging. CD4+ and zincaemia values are within the lower limits of normal range in urinary tract infections. Zincaemia and HIV-RNA or CD4+ are inversely correlated (r = 0.57 and r = 0.72, respectively) in HIV+ HAART treated subjects. Consequently there is no appearance of opportunistic infections. Parallelism between aging and HIV may exist because of the resemblance in marked zinc deficiency and CD4+ depletion with high scores in relative risks for severe infections relapse. Supplementing zinc (12 mg Zn++/day) for one month in infected elderly subjects and HAART therapy in HIV+ subjects reduces risk scores in CD4+ and zincaemia deficiencies for infections relapse, suggesting that the zinc beneficial effect may be independent either by HIV-virus or pathogen agents involved. While HAART may reduce the occurrence of opportunistic infections in HIV by means of also major zinc bioavailability, supplementing zinc can be recommended in elderly people as resistance to infections. Since zinc deficiency is correlated with CD4+ depletion, this latter may also be good diagnostic marker to detect 'clear immunodeficiency' in aging, as in HIV condition.

Adult↗
PubMed1997

Decrease of rotenone inhibition is a sensitive parameter of complex I damage in brain non-synaptic mitochondria of aged rats.

We investigated NADH oxidation in non-synaptic and synaptic mitochondria from brain cortex of 4- and 24-month-old rats. The NADH oxidase activity was significantly lower in non-synaptic mitochondria from aged rats; we also found a significant decrease of sensitivity of NADH oxidation to the specific Complex I inhibitor, rotenone. Since the rotenone-binding site encompasses Complex I subunits encoded by mtDNA, these results are in accordance with the mitochondrial theory of aging, whereby somatic mtDNA mutations are at the basis of cellular senescence. Accordingly, a 5 kb deletion was detected only in the cortex of the aged animals.

Aging↗
PubMed1997

Thyroid-thymus interaction on beta-adrenoceptor regulation during development and ageing.

Up-regulation of brain cortex beta-adrenoceptors (beta ARs) can be induced by very acute stimulation with a single injection of T4 or T3 in young Balb/c-nu mice. We have also shown that this very rapid receptor increase can also be demonstrated in ageing animals when stimulated with T3 but not T4 injection. The aim of the present paper was to verify the capability of the thymus to reverse these impairments which we often observed in other experiments on old mice and young athymic nudes. The up-regulation induced by T4 and T3 was studied in normal and athymic nude young, normal old, and normal old and athymic nude young mice grafted with neonatal thymus 1 month earlier. In addition, since brain cortex bears both beta AR subpopulations, the eventual differential behavior of beta 1AR and beta 2AR subtypes was also investigated. Animals were injected intraperitoneally with saline, or saline containing 0.5 microgram T3 or 6.4 micrograms T4 per g body weight and killed 15 or 60 min after injection. Results show that thymus can recover the modifications of basal levels as well as T3-induced up-regulation of beta ARs in nude and old mice. On the contrary, impaired response to T4 stimulation is corrected in nude but not in old mice. The peripheral conversion of T4 into T3 can explain their differential influence since a correct conversion only occurs in presence of an efficient beta-adrenergic function. Thus, a vicious circle may occur with a decreasing number of beta-adrenoceptors causing in old age altered T4 to T3 conversion, in turn responsible for altered beta-adrenergic responsiveness to T4.

Aging↗
PubMed1996

Presence of a DNA-4236 bp deletion and 8-hydroxy-deoxyguanosine in mouse cardiac mitochondrial DNA during aging.

A particular mitochondrial DNA (mtDNA) deletion, the so-called "common deletion", accumulates progressively with age in human post-mitotic cells. We investigated the presence of age-related mtDNA deletions in mouse heart and, according to the free-radical theory of aging, the potential involvement of reactive oxygen species (ROS). Hearts from young, adult and old male Balb/c mice were homogenized and centrifuged in order to discard nuclear DNA. The supernatant was then utilized to prepare mtDNA by SDS-proteinase K digestion. The presence of a mtDNA4236 deletion was estimated by PCR analysis, by separating the amplificated segment on agarose gel. The incidence of the mtDNA4236 deletion was 16%, 28% and 78% in young, adult and old mice, respectively. 8-hydroxy-2'-deoxyguanosine (8-OH-dG), a marker of DNA oxidation, was also determined by HPLC-electrochemical analysis. 8-OH-dG was not detectable in young mice, while its concentrations (moles 8-OH-dG/10(6) moles dG; mean +/- SD) were 59.0 +/- 1.41 and 31.0 +/- 4.24 (p < 0.02) in adult and old mice, respectively. These data indicate that a mtDNA4236 deletion is progressively associated with aging in mouse hearts, and that oxidative damage to mtDNA is greater in middle-aged than senescent animals.

8-Hydroxy-2'-Deoxyguanosine↗
PubMed1994

Immune enhancement by conditioning of senescent mice. Comparison of old and young mice in learning ability and in ability to increase natural killer cell activity and other host defense reactions in response to a conditioned stimulus.

It has been clearly demonstrated that immune responses may be conditioned in a manner similar to that of the classical Pavlovian experiments. Evidence of impaired immune function in aging has raised the question of whether psychological conditioning of an immune response can also be effective in old age. The knowledge that aged mice have decreased spleen cell natural killer (NK) activity and that NK cytotoxicity, at least in young mice, can be psychologically conditioned led us to explore in old mice the possibility of conditioning the response of NK cell activity using the odor of camphor as the conditioned stimulus (CS) and the injection of Poly I:C as the unconditioned stimulus (US). Young and old male mice were divided into five and six groups, respectively. They received the CS and/or the US in association (conditioning) trials (sessions 1-9). Mice were exposed to the camphor odor alone at 72 hours after the final association trial to observe the conditioning phenomenon (session 10). The group conditioned with Poly I:C and camphor and receiving the CS at session 10 showed statistically significant increases in spleen cell NK activity over those of the control groups that did not receive the CS treatment at session 10 (2.6- and 4.0-fold increase in young and old, respectively). Treatment with camphor odor alone had no effect on boosting NK cell activity. These findings demonstrate the possibility of conditioning immune responses in old age, offering a valuable tool for attenuating age-related immune deterioration in various species, including the human. In addition, these results again confirm highly significant immune enhancement by classical conditioning and extend previous findings from female mice to males as well.

Aging↗
PubMed1992

Age-related alterations of isoproterenol-stimulated adenylyl-cyclase activity are partially corrected by thymic graft.

Previous experimental results have demonstrated progressive impairments in beta-adrenergic responsiveness with advancing age. Beta-adrenoceptors are involved in the alterations as their density progressively decreases during aging. Alterations in both in vivo responsiveness and receptor density are corrected by neonatal thymic grafts. In the present paper adenylyl-cyclase (AC) activity has been studied in the same animal models used before. Results show that no statistically significant changes can be observed when AC is assayed in absence of beta-adrenergic stimulation. On the contrary, when assayed after Isoproterenol stimulation, AC activity shows a shift of the peak and a decrease of its height in aged animals. A neonatal thymus grafted into old recipients one month before the experiment was performed, is capable of correcting the altered height of the peak but not the peak concentration.

Adenylyl Cyclases↗
PubMed1991

Thymus-induced recovery of age-related decrease of brain cortex alpha- and beta-adrenoceptors.

It has previously been demonstrated that thymus exerts a regulatory influence on beta-adrenergic system during aging. In particular, it has been shown that thymus can correct the beta-adrenoceptor density decrease in old mice. In the present paper results of experiments are reported dealing with the influence of the thymus on alpha-adrenoceptors of mouse brain cortex. Both subtypes of alpha-adrenoceptors are studied separately, using different labelled ligands. Results show that alpha 1-adrenoceptor density decreases in old animals, while alpha 2-adrenoceptor density does not change significantly. A neonatal thymus grafted into old recipients is capable of correcting the alteration observed in old mice. The differential impairment of alpha-adrenoceptors resembles that one previously observed on beta-adrenoceptors, where beta 1-type decreases in number during aging with a parallel decrease of adenylyl-cyclase activity, while beta 2-type remains unchanged.

Adenylyl Cyclases↗
PubMed1990

Influence of age on the thyroid hormone-induced up-regulation of beta-adrenoceptors in mouse brain cortex.

The influence of ageing on the ability of the brain cortex beta-adrenoceptors to be regulated by very short stimulation with thyroid hormones has been investigated. Experiments were performed in 3-, 10-, 17- and 22-month-old mice using both thyroxine (T4) and triiodothyronine (T3) as stimulators and analyzing beta-adrenergic receptor characteristics 15 and 60 min after hormone injection. Results showed that a statistically significant up-regulation is present in both young and old mice when treated with T3. On the contrary, after T4 injection only 3-month-old animals respond to such a short-term treatment, whereas older adult and old animals showed not statistically significant changes. Thus, the impairment in the T4-induced up-regulation starts already in adult mice and does not seem to further increase progressively with advancing age. From these findings it is suggested that the lack of responsiveness of beta-adrenoceptors to T4 but not to T3 stimulation in adult and old mice may be due to relatively early impairment in the transformation of T4 into T3.

Age Factors↗
PubMed1989

Ageing and thymus-induced differential regulation of beta 1 and beta 2 adrenoceptors of mouse brain cortex.

Two questions have been addressed by the present paper, that is, the differential influence of age on beta 1 and beta 2 receptors and the thymus-induced recovery of such changes in receptor density and affinity have been assayed in brain cortex of Balb/c-nu mice of different ages. Results have shown a progressive decrease of beta 1 receptor density with advancing age, while no statistically significant changes were observed in beta 2 receptor density. Receptor affinity did not show any changes among the various groups examined. The influence of the thymus on receptor characteristics has been studied comparing young, old and thymus-grafted old mice. Total receptor density, which is decreased in old animals, can be up-regulated by thymus graft in old recipients. Interestingly, such a corrective effect is exerted only on the beta 1 population, the beta 2 receptor not being significantly affected. Thymic graft, therefore, acts just on the population which is found altered during ageing.

Aging↗