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Biomedical subjects

A Albano

Publications and source records attributed to A Albano.

At least 19 recordsLinked to original sources
PubMed2002

Immunity to poliomyelitis: situation in northern Italy and in some other European population groups.

The aim of the program to eradicate poliomyelitis is expected to be achieved in the space of very few years and therefore, as they approach this goal, countries find themselves faced with various problems to be tackled. Among these is the decision about how and when to stop polio vaccination, which also depends on seroepidemiological evaluations, necessary because of the possible persistence of circulating strains of poliovirus of vaccine origin which might continue even after the suspension of vaccination. For this reason, the results of seroepidemiological surveys carried out in some European countries in different periods of time and on various samples of the population are discussed. Although the status of immune coverage is satisfactory, a few situations of susceptibility were found; these should be better monitored and, if necessary, corrected to guarantee a homogeneous and lasting resistance of the European population towards polioviruses.

Adolescent↗
PubMed1999

Survival ability of cytotoxic strains of motile Aeromonas spp. in different types of water.

The ability of motile Aeromonas spp. to survive in drinking water (mineral and tap water) and in sea water was experimentally tested. Clinically isolated cytotoxic strains of A. hydrophila, A. caviae and A. sobria were selected for this study. After contamination of water samples, the survival of Aeromonas strains was studied for at least three months using viable counts. The results obtained show that the survival of the Aeromonas spp. varies considerably depending on species and water type. For all three species, the survival time was longest in mineral water, where viable bacteria of each strain were still detected after 100 d. Moreover, A hydrophila and A. caviae also re-grew on the first day. In tap water all strains showed marked survival, although to a lesser extent than in mineral water. Aeromonas cells showed a rapid decline in sea water (90% reduction in viable cells after about two d) and thus seem to be more sensitive to saline/marine stress than chlorination.

Aeromonas↗
PubMed1999

Long-term follow up of a randomized, controlled trial on prophylactic sclerotherapy of small oesophageal varices in liver cirrhosis.

BACKGROUND: In order to evaluate the prophylactic impact of sclerotherapy of small varices in patients with cirrhosis and no endoscopic signs suggesting risk of haemorrhage, a randomized clinical trial was performed. METHODS: Seventy-one hospitalized patients met the inclusion criteria of diagnosis of cirrhosis with no previous bleeding and small varices. Due to exclusion criteria of: gastroduodenal ulcers (n = 5), diverticulosis (n = 1), hepatic insufficiency (n = 10), hepatocellular carcinoma (n = 4), death before randomization (n = 6), age over 70 (n = 1) and denial of consent to participate in the study (n = 1), 43 patients could be randomized, 21 for sclerotherapy and 22 for the control group. Two patients (one in each group) were lost to follow up, and another patient, although not lost, refused sclerotherapy after randomization. Ethanolamine oleate was used as the sclerosing agent. All patients were followed up for a mean time of 60 months, initially every 2 months for the first 2 years and clinical and endoscopic controls were performed each 6-12 months thereafter. RESULTS AND CONCLUSIONS: During the first 2 years clinical assessment showed that there were five bleedings in the sclerotherapy group and none in the control group, but mortality was similar in both groups. Long-term follow up continued to show a higher prevalence of bleeding in the sclerotherapy group but that mortality was not different from the control group.

Esophageal and Gastric Varices↗
PubMed1998

Bactericidal effect of chlorine on motile Aeromonas spp. in drinking water supplies and influence of temperature on disinfection efficacy.

The susceptibility of toxigenic Aeromonas spp. to free chlorine in drinking water supplies, and the influence of environmental temperature on the bactericidal activity of the oxidant, were evaluated. The results showed inactivation curves characterized by an initial phase of rapid reduction of viable cells followed by a slow inactivation of bacteria. The effect of the chlorine compound was markedly influenced by water temperature. At a summer water temperature (20 degrees C), the efficacy of the chlorine concentrations tested was found to be two to three times lower compared to that found at a winter temperature (5 degrees C). Resistance was moderately, but significantly, greater in Aer. hydrophila vs Aer. caviae and Aer. sobria, but all Aeromonas spp. were more susceptible than Escherichia coli. Selective pressure with free chlorine did not produce Aeromonas cells with higher levels of chlorine resistance.

Aeromonas↗
PubMed1998

Acute oxygen supplementation does not relieve the impairment of respiratory muscle strength in hypoxemic COPD.

STUDY OBJECTIVES: To verify whether hypoxemia affects respiratory muscle strength in the absence of malnutrition and whether such effect, if present, is reversible with an acute oxygen supplementation. DESIGN: Case series analysis, before-after trial. SETTING: Outpatient pneumology departments of two university hospitals. PATIENTS: One hundred twenty patients affected by COPD in stable conditions having actual to ideal body weight ratio of > or =90%. MEASUREMENTS AND RESULTS: Maximal inspiratory pressure (MIP) was measured at functional residual capacity level in the whole sample of subjects and during oxygen supplementation in 58 patients having a PaO2< or =60 mm Hg when breathing in room air. Predictors of MIP were assessed by a multivariate analysis. MIP values before and after oxygen supplementation were compared by a paired t test. MIP was independently correlated with FVC (p<0.001), PaO2 (p<0.01), and age (p<0.01). In the subgroup of hypoxemic patients, MIP values did not change significantly after oxygen supplementation (3.08+/-1.74 vs 3.03+/-1.91 kPa, t=0.43, not significant). CONCLUSIONS: Hypoxemia is an important negative correlate of MIP even in well-nourished COPD patients. Its effect is not reversible with an acute oxygen supplementation.

Age Factors↗
PubMed1998

Virulence factors in Aeromonas spp and their association with gastrointestinal disease.

Culture filtrates of eight Aeromonas strains isolated from the feces of 487 subjects (292 diarrhoeic patients and 195 asymptomatic subjects) were tested for toxin production in CHO and McCoy cells, and adhesion and invasive ability in Caco-2 cells. Among these isolates, three Aeromonas sobria and one Aeromonas caviae strains possessed virulence-associated properties. Toxin production was the most common of the three virulence properties. Two A. caviae were associated, in the absence of other diarrhoeagenic agents, with gastroenteritis; however, a virulence marker (cytotoxin) was recognized only in one strain. Two strains of A. sobria isolated from subjects with gastroenteritis were shown to be associated with one (cytotoxicity) or two (adhesion and invasive abilities) virulence factors, respectively. However, a third strain of A. sobria, although cytotoxic and invasive, was isolated from an asymptomatic subject. The results show that Aeromonas spp may act as human enteric pathogens, but also indicate that the significance of several putative virulence factors, such as production of cytotoxin and the capacity to adhere to and invade mammalian cells, remains controversial in explaining the enteropathogenesis of Aeromonads and therefore needs further studies.

Aeromonas↗
PubMed1997

Increased microbicidal activity of human monoblastoid cells upon long-term exposure to dideoxycytidine.

2',3'-Dideoxycytidine (ddC) is a nucleoside analogue currently used in AIDS therapy. We had previously found that long term exposure of U937 human monoblastoid cells to ddC induces the selection of drug-resistant cells (U937-R). In the present work we investigated some important biochemical properties and functional activities of these resistant cells. The results obtained show that U937-R maintained the properties of cell aggregation, adhesion and differentiation. Basal respiration, protein kinase C activity, superoxide anion release and intracellular free calcium were all increased in the drug-resistant line. Phagocytosis of fungi (Candida albicans) and bacteria (Staphylococcus aureus and Salmonella anatum) were similar in U937 and U937-R cells. Killing of C. albicans was significantly higher in drug-resistant cells (29.07 +/- 2.23% of killing vs 19.07 +/- 2.01 in the control; p < 0.001). Similarly, the bacterial killing was enhanced in U937-R cells (34.07 +/- 8.06% vs 22.60 +/- 4.41% in the control; p < 0.05). Thus, the results presented in this paper provide evidence of an increased microbicidal activity of human monocytic cells upon long term exposure to ddC, most likely due to an increased oxidative metabolism.

Blood Bactericidal Activity↗
PubMed1997

Antipoliomyelitis immunity status in a cohort of young men drafted into military service, residing in the suburban Milan area.

The aim of this study was to verify the antipolio immune status of a cohort of eighteen year-olds residing in the suburban Milan area for whom vaccination histories were available. Seropositivity (titres of neutralizing antibodies > or = 1:8) for the three virus serotypes was detected in 89.2% of the 530 subjects tested, whereas simultaneous seronegativity for all three polioviruses was found for only 0.6% of the subjects.

Adolescent↗
PubMed1997

Comparison of colloidal bismuth subcitrate and metronidazole, both in combination with an H2-antagonist as therapy for Helicobacter pylori.

In this random study, the efficacy of either colloidal bismuth subcitrate (CBS) or metronidazole in combination with an H2-antagonist in the treatment of various gastric pathologies was evaluated, along with the trends in antibody levels. Among the 40 Helicobacter pylori-positive patients with various gastroduodenal pathologies who underwent chemotherapy, 27 were treated with CBS and 13 with metronidazole. H. pylori was eradicated in 48.14% of the patients treated with CBS and 53.8% of those treated with metronidazole. After therapy, no statistically significant or slight decrease in the serum levels of antibodies was found.

Adult↗
PubMed1995

Action of cystine in the cytotoxic response of Escherichia coli cells exposed to hydrogen peroxide.

Cystine markedly enhanced the cytotoxic response of Escherichia coli cells to concentrations of hydrogen peroxide resulting in mode one killing, but displayed little effect in mode two killed cells. The effect of cystine was concentration-dependent over a range of 5-50 microM and did not further increase at higher levels. Cystine had similar effects in other bacterial systems. In order to sensitize the cells to the oxidative injury, the amino acid must be present during exposure to the oxidant since no enhancement of the cytotoxic response can be observed in cystine pre-loaded cells. In addition, no further enhancement of cytotoxicity could be detected when cystine was added before and left during challenge with the oxidant. The enhancing effect of cystine on oxidative injury of E. coli cells appears to be directly mediated by the amino acid and in fact cysteic acid, the most likely oxidation product, had no effect on the killing of bacterial cells elicited by hydrogen peroxide. Other disulfide compounds such as oxidized glutathione, cystamine and dithionitrobenzoic acid only slightly increased the susceptibility of bacteria to the oxidant. The effect of the disulfides was not concentration-dependent over a range of 200-800 microM and was statistically significant only for cystamine. Taken together, these results indicate that cystine markedly increases the cytotoxic response of bacteria to hydrogen peroxide and suggest that the amino acid might impair the cellular defence machinery against hydrogen peroxide. This effect may involve a thiol-disulfide exchange reaction at the cell membrane level.

Cystine↗
PubMed1993

Sexual transmission of hepatitis C virus and HIV-1 infection in female intravenous drug users.

We examined the relationship between the presence of antibody to HCV and sexually transmitted diseases in 151 female, intravenous drug users aged 17-43 years. Anti-HCV was present in 49 of 66 HIV-1-negative women (74.2%), and 63 of 85 HIV-1-positive women (74.1%). Anti-HCV seropositivity was significantly related to sexually transmitted infections (Ureaplasma urealyticum infections excluded) in HIV-1-seronegative women, but not in HIV-1-positive women. Also, in HIV-1-negative subjects. Trichomonas vaginalis infections (and infections with M. hominis) were significantly related to anti-HCV seropositivity, and a positive relation between the number of sexual partners and the presence of anti-HCV was demonstrated. In HIV-1-positive subjects a shared use of needles and syringes was more likely, and an increased parenteral exposure to HCV may decrease the relative contribution by sexual transmission. However, in HIV-1-negative subjects, sexual transmission of HCV appears to be both a possible and important means of transmission.

Adolescent↗
PubMed1993

The bone marrow in murine AIDS.

In order to increase the understanding of blood cytopenias in HIV infection we have investigated the bone marrow in murine AIDS. C57BL/6 mice infected with the LP-BM5 retrovirus show a decrease in cellularity, numerous haemophagocytic histiocytes, a reduction of all erythroid precursor cells, an increase in eosinophil number and an increase in lymphocytes. Immunostaining with an anti-Pr60gag antibody shows that the majority of bone marrow cells express the viral protein. Thus, the bone marrow in MAIDS has many similarities with the bone marrow from patients with advanced AIDS and may prove useful as a model for therapy aimed at treating blood cytopenias.

Animals↗
PubMed1992

Prevalence of anti-HCV in subjects of various age groups.

812 serum samples from 382 males and 430 females from various age groups were examined. All the samples were tested for anti-HCV hepatitis C virus, anti-HBc and HBsAg with an enzymeimmunoassay. The total serum prevalence was 2.9% for anti-HVC, 22.2% for anti-HBc and 4.6% for HBsAg. The seropositivity rates of anti-HCV and anti-HBc tended to increase with age, while for HBsAg a more regular pattern was observed for the different subject groups. The fact that anti-HCV are more frequently found together with HBV markers confirms the existence of similar modes of transmission of the two viruses.

Adult↗
PubMed1992

In vitro and in vivo toxicity of 2',3'-dideoxycytidine in mice.

3T3 mouse embryo fibroblast cell growth was inhibited in a concentration dependent manner by 2',3'-dideoxycytidine (ddCyd), a strong inhibitor of human immunodeficiency virus. Cell growth inhibition was associated with an increased incorporation of ddCyd into cell DNA. In contrast SP2/0-Ag14 (a mouse myeloma) cell growth is not inhibited by 100 microM ddCyd both in the presence or absence of hypoxanthine and thymidine. Furthermore, in vitro spleen cell proliferation, upon phytohemagglutinin (PHA) addition, was much more affected by ddCyd in C57BL/6 mice than in Swiss albino mice. That indeed ddCyd affects spleen cell proliferation was confirmed by studies on splenocytes obtained from C57BL/6 mice that received ddCyd for 2 weeks in drinking water. These results suggest that ddCyd toxicity in mice is cell and strain dependent and that the toxicity mechanism is related to the incorporation of the drug in cell DNA.

3T3 Cells↗
PubMed1992

Differential effect of the amino acid cystine in cultured mammalian and bacterial cells exposed to oxidative stress.

The effect of cystine in the cytotoxic response of cultured Chinese hamster ovary and Escherichia coli cells to challenge with hydrogen peroxide has been investigated. It was found that this amino acid could either protect or sensitize cells, depending on the cellular system. In fact, although a reduction in the growth-inhibitory effect of hydrogen peroxide was observed in mammalian cells, a marked increase in the susceptibility to oxidative stress was induced by cystine in bacteria. None of the amino acid precursors of glutathione, e.g., glutamate, glycine or cysteine, afforded protection in the mammalian cell system, whereas cysteine, but not glycine or glutamate, markedly sensitized bacteria to hydrogen peroxide-induced cell killing. In mammalian cells, methionine, an amino acid which is converted to cysteine, was also unable to modify the oxidative response. The results presented indicate that cystine displays differential effects in oxidatively injured mammalian or bacterial cells and suggest that the mechanism whereby the amino acid modulates the lethal action of hydrogen peroxide differs in the two cellular systems.

Animals↗
PubMed1991

In vitro toxicity and metabolism of 2',3'-dideoxycytidine, an inhibitor of human immunodeficiency virus infectivity.

U937 human monoblastoid cell growth was inhibited in a concentration-dependent manner by 2',3'-dideoxycytidine (ddCyd) (an antiretroviral drug) up to 500 microM. Cell growth inhibition was associated with a pronounced increase in cell volume, however this was not due to cell ATP or NAD+ depletion that could effect osmotic balance or DNA repair. This ddCyd toxicity paralleled the accumulation of ddCyd into acid soluble material where 2',3'-dideoxycytidine-5'-triphosphate (ddCTP) was the predominant labelled nucleotide up to an extracellular ddCyd concentration of 150 microM. At higher ddCyd concentrations, the amount of 2',3'-dideoxycytidine-5'-diphosphate (ddCDP) became predominant over ddCTP. This increase of phosphorylated dideoxycytidine in U937 cells was also associated with an increased incorporation of the drug into cell DNA suggesting a possible toxicity mechanism. That ddCyd does indeed become cytotoxic to human cell by incorporation into DNA was shown by incubating human resting and stimulated lymphocytes with ddCyd. While the drug does not affect cell viability in resting cells it strongly affects cell proliferation upon phytohemagglutinin (PHA) addition.

Adenosine Triphosphate↗