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Biomedical subjects

F Castelli

Publications and source records attributed to F Castelli.

At least 73 records · Page 4Linked to original sources
PubMed1995

The ability of CD4+ cells from HIV+ individuals to express CD40 ligand after in vitro stimulation is not impaired.

Interaction between the B cell glycoprotein CD40 and its ligand (CD40L), expressed by activated T cells, is of crucial importance in the generation of specific antibody response, which is impaired in HIV+ individuals. We studied the expression of CD40L by lymphocytes activated with PMA plus ionomycin in 17 HIV+ individuals and 12 healthy donors. In HIV+ individuals, the percentage of cells expressing CD40L was lower than that in the controls (22.6 +/- 14.7 vs 40.1 +/- 12.0; P < 0.002) and clearly correlated with that of CD4+ peripheral blood lymphocytes (r = 0.83; P < 0.001); therefore, the reduced CD40L expression might be explained by the decrease of the CD4+ cells. In fact, the expression of CD40L by purified CD4+ cells was comparable in individuals with and without HIV infection. These data indicate that the ability of CD4+ cells from HIV individuals to express CD40L is not impaired, at least after optimal stimulation in vitro.

Adult↗
PubMed1995

Flavonoids as antioxidant agents: importance of their interaction with biomembranes.

Flavonoids, a group of phenolic compounds widely occurring in the plant kingdom, have been reported to possess strong antioxidant activity. In the present study, four flavonoids (quercetin, hesperetin, naringenin, rutin), chosen according to their structural characteristics, were tested in two different in vitro experimental models: (1) Fe(2+)-induced linoleate peroxidation (Fe(2+)-ILP), by detection of conjugated dienes; and (2) autooxidation of rat cerebral membranes (ARCM), by using thiobarbituric acid for assay of free malondialdehyde production. The results obtained were also interpreted in the light of flavonoid interactions, studied by differential scanning calorimetry, with dipalmitoylphosphatidylcholine (DPPC) vesicles as a biological membrane model. The antilipoperoxidant activity of the flavonoids tested can be classified as follows: rutin > hesperetin > quercetin > naringenin in the Fe(2+)-ILP test: quercetin > rutin > hesperetin > naringenin in the ARCM test. Quercetin, hesperetin, and naringenin interacted with DPPC liposomes causing different shifts, toward lower values, of the main transition peak temperature (Tm) typical for DPPC liposomes; however, no change in Tm of DPPC dispersion was observed in the presence of rutin. The hypothesis will be discussed that flavonoid capacity to modify membrane-dependent processes, such as free-radical-induced membrane lipoperoxidation, is related not only to their structural characteristics but also to their ability to interact with and penetrate the lipid bilayers.

Animals↗
PubMed1995

Epidemiology of traveler's diarrhea.

Annually, over 75 million international passengers travel to tropical areas, more than 20 million of whom come from industrialized countries. They experience a high rate of traveler's diarrhea (TD), varying from 20 to 56%, which may result in serious limitations to their activities. The cause of TD is considered to be infectious in the overwhelming majority of cases and, apart from differences in relative importance, the list of responsible microbial agents is fairly constant regardless of geographic origin. The ingestion of contaminated food or water is considered to be the principal mode of transmission of the enteric pathogens of TD. Several factors have been proposed as playing a role in the etiogenesis of diarrhea in travelers, including personal (age, socioeconomic status, body weight, preexisting gastrointestinal illnesses), behavioral (mode of travel, standard of accommodation, eating in public places, dietary errors) and travel-related (destination, duration of stay, country of origin, season) factors, which are reviewed in detail.

Animals↗
PubMed1994

Correlation between monoamino oxidase inhibitor activity of some thiazol-2-ylhydrazines and their interaction with dipalmitoylphosphatidylcholine liposomes.

A calorimetric investigation has been carried out on the influence exerted by some 1-(alkoxybenzoyl)-2-(4-substituted thiazolyl-2-yl)hydrazines, possessing monoamine oxidase inhibitory (MAOI) activity, on the thermotropic behavior of model membranes constituted by dipalmitoylphosphatidylcholine (DPPC) vesicles. Attention was paid to evaluate how structural variations of drugs may influence drug-lipid interaction. The examined drugs were found to modify the gel to liquid-crystal phase transition of DPPC liposomes, by causing a shift of the transition temperature (Tm) toward lower values and a negligible variation in the enthalpy changes (delta H). The different effects on DPPC thermotropic behavior of these MAOI drugs could be considered in terms of different substituents on the molecule's backbone. The calorimetric results were related to drug's MAO inhibitory activity measured by fluorescence techniques and the apparent distribution coefficient of the compounds in water/n-octanol. A hypothesis on a correlation between a drug's structure, inhibitory activity, and membrane interaction has been suggested.

1,2-Dipalmitoylphosphatidylcholine↗
PubMed1994

Short report: verruga peruana in an Italian traveler from Peru.

We report a case of cutaneous bartonellosis in a 24-year-old Italian woman. Soon after returning from a seven-month stay in a central area of Peru at an altitude of 3,130 meters, she developed high fever, headache, and muscle and joint pain that resolved after antibiotic therapy. Two months later, she presented with disseminated, painless, firm, purple, subcutaneous nodules on the neck, shoulders, legs, left eyelid, and hard palate, some of which developed into vegetating lesions. The diagnosis of bartonellosis was made on the basis of the clinical picture, the patient's medical history, the incubation period, the confirmatory histopathologic findings, and the response to treatment with chloramphenicol (500 mg four times a day for 14 days).

Adult↗
PubMed1994

Short report: imported mosquito: an uninvited guest.

Recently, the trend in the number of people traveling from the tropics to malaria-free areas has tremendously increased and this is paralleled by the number of imported malaria cases. Imported infected mosquitoes transmitting the infection to persons living or working nearby international airports have been reported. The possibility that mosquitoes may also reach areas far away from the landing area in the baggage of international travelers is indicated by two cases that are reported here. Malaria should be investigated in any case of unexplained fever even if no apparent risk factor for imported malaria is present, regardless of the distance from international airports.

Animals↗
PubMed1994

[Primary embryonal rhabdomyosarcoma of the breast. Description of a case].

Authors report a case of embryonal rhabdomyosarcoma of the breast occurring in a 16-year-old girl. To date, 26 cases have been described in the literature of which only 4 in girls younger than 16 years. Histological features, immunohistochemical findings and differential diagnosis are discussed.

Adolescent↗
PubMed1994

MAOI activity of thiosemicarbazides and related 2-thiazolylhydrazines.

The preparation is described of hydrazides I, thiosemicarbazides II, III, IV and hydrazinothiazoles VIII, which can be considered as "precursors" or "open models" for the synthesized benzoyl-, benzilidene- and benzyl-hydrazinothiazoles V, VI and VII, analogous to 4-methyl and 4-phenyl substituted derivatives A, B and C, described and tested for their MAOI activity in a previous paper. Biochemical assay on the new prepared compounds allowed us to better clarify the structure-activity relationship also of compounds A, B and C of the precedent note. Moreover, on a group of derivatives, which showed a higher activity, a further test was performed to observe the possible correlation between MAOI activity and both their lipophilicity and ability in interacting with liposome bilayers, taken as a model of cell membrane.

Animals↗
PubMed1993

[Cutaneous melanoma at the Turin Melanoma Center. Correlations of anamnestic data, histopathologic aspects and clinical picture in 306 stage-I patients (1990-1991)].

The correlation between anamnestic data, histological and clinical features in 306 stage I patients, studied at the Melanoma Centre in Turin during the period 1990-1991, have been analyzed. The somatic features, the distribution by sex and age, clinical findings, histological type, the Clark assessment and Breslow's thickness are reported. In a short interview, patients were asked about when the lesion and its modifications appeared. The patients have shown a low level of information about the risk of malignant melanoma. The answers prove totally unreliable and the comparison between anamnesis and histological picture has not helped to explain the natural history of melanoma. Both men and women with more formal education have been at greater risk for malignant melanoma than those with less education. The authors underline the importance of the public education campaign on early detection of this tumor.

Adult↗
PubMed1993

Transmission of HIV-associated tuberculosis to healthcare workers.

OBJECTIVE: A retrospective investigation was made to compare the occupational risk of tuberculosis in personnel assisting human immunodeficiency virus (HIV)-infected and uninfected subjects with active tuberculosis. DESIGN: We retrospectively reviewed 6 years of hospital activity in 3 units where HIV-infected patients with tuberculosis are hospitalized and in 2 units where non-HIV-infected tuberculosis patients are hospitalized. The risk of occupational tuberculosis in healthcare workers who assisted HIV-infected and non-HIV-infected patients with tuberculosis was investigated. PARTICIPANTS: The risk of occupational tuberculosis in healthcare workers was studied by considering the numbers of potential source cases (hospitalized patients with tuberculosis) in the two conditions investigated (HIV-positive and HIV-negative). Both potential source cases and cases of tuberculosis in healthcare workers had to be microbiologically proven in order to be considered. RESULTS: Seven cases of tuberculosis occurred in persons who cared for 85 HIV-infected subjects with tuberculosis, while only 2 cases occurred in staff members who took care of 1,079 HIV-negative tuberculosis patients over the same period (relative risk = 44.4; 95% confidence interval = 8.5-438). CONCLUSIONS: Tuberculosis seems no longer to be a neglectable risk in healthcare workers assisting patients with HIV infection. Further study is urgently needed to see whether such unexpectedly high dissemination of tuberculosis also is demonstrable in the community.

HIV Infections↗
PubMed1992

[Drug sensitivity study of Plasmodium falciparum in the city of Yaounde (Cameroon)].

In July 1990, the in vitro chemosensitivity of 22 isolates of Plasmodium falciparum was assessed by an isotopic semi-microtest in Yaounde, Cameroon. Out of them, 54.5% were resistant to chloroquine, 28.6% to amodiaquine, 4.8% to quinine and 4.5% had a decrease of sensitivity to mefloquine. A strong positive correlation between the IC50 of the antimalarial drugs compared by pairs was detected.

Adolescent↗
PubMed1991

Occlusion of the carotid artery as presenting symptom of acute promyelocytic leukemia.

In a 44-year-old female acute promyelocytic leukemia (APL) presented with abrupt onset of right hemiplegia and aphasia due to occlusion of the left carotid artery at bifurcatio. There was laboratory evidence of disseminated intravascular coagulation (DIC). Thrombotic complications are unusual in APL, even in cases with evidence of DIC. This report aims at underlying the important implication of a correct timely diagnosis in young patients presenting with stroke.

Adult↗