Biomedical subjects

C Andreoli

Publications and source records attributed to C Andreoli.

At least 37 records · Page 2Linked to original sources

PubMed1997

Ultrasonographic evaluation of de Quervain disease.

De Quervain disease is a job-related tenosynovitis that affects the synovial sheath of the tendons of the abductor pollicis longus and extensor pollicis brevis muscles; it is associated with pain and functional impairment and progresses to cause local fibrosis with blockage or triggering of the thumb. High-resolution ultrasonography of the wrist was performed in eight patients with de Quervain disease; the examination was performed in axial and coronal scans with a 13 MHz linear transducer. The evaluation of normal wrists helped to define the normal sonographic anatomy of the first extensor compartment; obvious changes of the tendon sheath were noted in all cases of de Quervain disease (thickening and edema of the synovial sheath and fluid within the sheath). We conclude that ultrasonography is able to confirm the clinical diagnosis of de Quervain disease and may have a role in the follow-up of this disorder.

Acute Disease↗

PubMed1997

[Computerized tomography assessment of complications secondary to abdominal aortic prosthesis].

PURPOSE: CT has gained an important role in the diagnosis of the complications of prosthetic surgery of the abdominal aorta: the importance of such complications comes from their frequency, which is proportional to the increasing number of interventions, and their severity. We investigated the CT patterns of the most frequent complications. MATERIALS AND METHODS: 24 patients referred for strongly suspected postoperative complications were examined in 2 years: fever and leukocytosis (20 cases) and progressive anemia (4 cases) were the most frequent findings. The operation had been performed 7 +/- 12 weeks before (2 patients were excluded because surgery dated less than 3 weeks). RESULTS: 14 patients had infective complications: thickening (57%) and inhomogeneity (43%) of the periprosthetic wrap and ectopic gas bubble (78%) were the most frequent CT findings. We also observed 2 periprosthetic hematomas, 1 aneurysm relapse and 1 prosthetic graft rupture. CONCLUSIONS: In conclusion, CT confirmed its important role in the study of the complications of prosthetic aortic surgery, despite its known poor specificity in the demonstration of the aorta in the first 2-3 months postoperatively, in the initial stages of infection and in the diagnosis of aorto-enteric fistulas.

Aorta, Abdominal↗

PubMed1997

[The echographic and computed tomographic assessment of "spontaneous" hematomas of the abdominal wall].

INTRODUCTION: Hematomas of the abdominal and pelvic wall are frequent findings, particularly in the patients undergoing long-term anticoagulant therapy. MATERIALS AND METHODS: We reviewed a series of 9 cases of "spontaneous" hematomas of the rectus abdominis muscle (7 cases), of the obliquus internus muscle (one case) and of the gluteus muscles (one case) studied with US and CT. During the last 4 years, 9 patients complaining of the recent onset of a painful muscular swelling were examined: 8 of them were on anticoagulant therapy, while one was on long-term hemodialysis. They were examined with US (3.5 MHz, integrated with 7.5 MHz in 7 cases) and CT (contiguous 10-mm slices before and after i.v. contrast agent injection). Color Doppler was used in 3 cases. RESULTS: US showed different signs depending on hematoma onset and extent: the muscle was swollen, with an inhomogeneous structure with both coalescing liquid and echogenic areas in 2 cases, while the hematomas were bigger and appeared with mostly liquid areas and internal inhomogeneity due to blood clots in the remaining 7 cases. The evidence of pseudocystic areas with fluid blood levels (the so-called pseudohematocrit effect) was particularly specific of diffuse hematomas (4 patients). CT helped make the final diagnosis by showing the typical hyperdensity of fresh blood (at least 50 HU) in 9 cases and by defining the typical pattern of the pseudocysts with the hematocrit effect, but was useless in characterizing "pseudotumoral" lesions (3 cases), which were better defined by B-mode and color Doppler US. CONCLUSIONS: US is the examination of choice, even though it may misdiagnose small hematomas as muscular tumors or large hematomas as other diseases; color Doppler can be useful in the former case. CT usually permits the correct diagnosis by detecting fresh blood, which can however be found also in some muscular neoplasms.

Abdominal Muscles↗

PubMed1996

Prediction of rodent carcinogenicity of further 30 chemicals bioassayed by the U.S. National Toxicology Program.

Recently the U.S. National Toxicology Program (NTP) sponsored a comparative exercise in which different prediction approaches (both biologically and chemically based) were challenged for their predictive abilities of rodent carcinogenicity of a common set of chemicals. The exercise enjoyed remarkable scientific success and stimulated NTP to sponsor a second challenging round of tests, inviting participants to present predictions relative to the rodent carcinogenicity of a further 30 chemicals; these are currently being tested. In this article, we present our predictions based on structure-activity relationship considerations. In our procedure, first each chemical was assigned to an activity mechanism class and then, with semiquantitative considerations, was assigned a probability carcinogenicity score, taking into account simultaneously the hypothesized action mechanism and physical chemical parameters.

Animals↗

PubMed1995

Toxicology of halogenated aliphatic hydrocarbons: structural and molecular determinants for the disturbance of chromosome segregation and the induction of lipid peroxidation.

The induction of mitotic chromosome malsegregation, mitotic arrest and lethality by a set of 55 halogenated hydrocarbons was investigated. To this aim, genetic assays in the mould Aspergillus nidulans, able to provide precise quantitative information on the end-points studied, were used throughout the work. The experimental data obtained were used to develop QSAR models for the induction of aneuploidy, which pointed to a major role of electrophilicity as molecular determinant for the aneugenic potential of the halogenated hydrocarbons investigated. Within the hypothesis of a link between the electrophilicity of haloalkanes and their propensity to undergo a reductive biotransformation, with production of free radical species, a subset of 27 compounds was also tested for the ability to induce lipid peroxidation in rat liver microsomes in vitro. The results obtained indicate a partial coincidence between the abilities to initiate lipid peroxidation and to disturb chromosome segregation at mitosis. The data base obtained was also used to investigate the relationship between chemical structure and peroxidative potential. The analysis indicated that electronic and structural parameters related to the ease of homolitic cleavage of the carbon-halogen bond play a pivotal role as determinants for the peroxidative character of haloalkanes.

Aneuploidy↗

PubMed1995

Relationships among in vitro mutagenicity assays: quantitative vs. qualitative test results.

In previous investigations, we studied the relationships between the profiles of the qualitative responses of in vitro short-term tests (mutation in Salmonella typhimurium, chromosomal aberrations in CHO cells, sister chromatid exchanges in CHO cells, and mutation in mouse lymphoma cells) and common sets of chemicals. In this paper, we address the study of the quantitative responses (potency). We show that two analyses point to similar patterns of relationships: the mutation in mouse lymphoma cells assay is most similar to the CHO sister chromatid exchange assay, and the Salmonella assay is most similar to the CHO chromosomal aberrations assay.

Analysis of Variance↗

PubMed1995

Tinnitus as a Presenting Symptom in Secondary Neuropathy: a Case Report.

The authors describe a case of neuropathy characterized by involvement of most of the right cranial nerves, the initial symptom of which was tinnitus. The most likely etiopathogenetic hypothesis seems to be the paraneoplastic syndrome in which a primitive neurogenic axon lesion is more likely, although a myelinopathic lesion cannot be ruled out. It is feasible to suggest that the tinnitus was caused by a central neuron demyelination associated with concomitant peripheral nervous system involvement. Observation of present case allows the authors to point out that tinnitus may be the early sign of neurological disease which can evolve into the central and/or peripheral neurologic disease.

Journal Article↗

PubMed1994

Effect of menstrual phase on surgical treatment of breast cancer.

1175 premenopausal women whose date of last menstrual period was known were followed up for up to 20 years (average 8 years) after surgery for breast cancer. 525 patients were in the follicular phase and 650 in the luteal phase. We observed 192 unfavourable events among patients operated on during the follicular phase (36.6%) and 192 among patients operated on during the luteal phase (29.6%). The effect of phase was restricted to patients with positive axillary nodes. The 5-year relapse-free survival was 75.5% in 246 node-positive patients operated on during the luteal phase and 63.3% in 190 node-positive patients who had surgery during the follicular phase. The hazard ratio at Cox multivariate analysis was 1.329 for all patients (p = 0.006) and 1.431 for node-positive patients (p = 0.03). In our study, premenopausal patients with breast cancer and positive axillary nodes operated on during the luteal phase had a significantly better prognosis than patients operated on during the follicular phase. It may be that the processes of cell metastases, such as loss of adhesiveness, may be enhanced by high concentrations of unopposed oestrogens or by reduced activity of natural killer cells during the first half of the menstrual cycle.

Adult↗

PubMed1994

QSAR models for both mutagenic potency and activity: application to nitroarenes and aromatic amines.

We studied the molecular determinants that discriminate between mutagenic and inactive compounds for: a) aromatic and heteroaromatic amines; b) nitroarenes. Mutagenic activity (data from literature) had been previously assessed in Salmonella typhimurium and Escherichia coli (SOS repair). The Quantitative Structure-Activity Relationships (QSAR) found were compared with those obtained in the laboratory of Professor C. Hansch for the mutagenic potency of the same compounds. It appears that there is a dramatic difference between the QSARs for potency, and those for yes/no activity: hydrophobicity played a major role in determining the potency of the active compounds, whereas mainly electronic factors differentiated the actives from the inactives. The electronic factors were those expected on the basis of the hypothesized metabolic pathways of the chemicals. Our interpretation is that the electronic factors (together with size/shape, possibly) determine the minimum requirement for the chemicals to be metabolized, whereas the hydrophobicity determines the extent of activity of chemicals that can be metabolized (actives). Moreover, the different QSARs found for the Salmonella strains TA98 and TA100 were discussed in the light of recent progress in the understanding of the molecular mechanisms of mutagenicity in these organisms. It is concluded that the nonlinear relationship observed for these chemicals between the two types of QSAR should be taken into account both when planning QSAR studies, and when using mutagenicity data for risk assessment.

Amines↗

PubMed1994

Ligation of CD4 surface antigen induces rapid tyrosine phosphorylation of the cytoskeletal protein ezrin.

Ezrin is a cytoskeletal protein which is tyrosine phosphorylated in human T lymphocytes upon stimulation through CD3 antigen (Egerton, M., Burgess, W., Chen, D., Druker, B. J., Bretscher, A., and Samelson, L. A., J. Immunol. 149, 1847, 1992). We found that tyrosine phosphorylation of ezrin was markedly enhanced by ligation of either CD3 or CD4 antigen and peaked between 1 and 2 min. Furthermore, stimulations through CD4 and CD3 antigens were additive. Using the cell line HUT 78 T transfected with either normal human CD4 or mutated CD4 molecules unable to associate with p56lck tyrosine kinase, we showed that this kinase plays a major role in the tyrosine phosphorylation of ezrin. Moreover, CD45R ligation studies provided evidence that the membrane-associated tyrosine phosphatase CD45 activity regulates ezrin tyrosine phosphorylation. Subcellular fractionation showed that although ezrin is mainly located in the cytosol of T cells, anti-CD4-induced ezrin phosphorylation involved the membrane fraction, with no concomitant translocation of the protein from the cytosol to the membrane.

Animals↗

PubMed1994

Antigen non-specific immunological tests in progressive sensorineural hearing loss.

The purpose of the present study was to determine the validity of antigen non-specific immunological tests in order to develop a risk-clinical profile of patients with immune-mediated inner ear pathology. The study was carried out on 38 patients with progressive sensorineural hearing loss and a control group of 26 subjects. Serological testing was used to determine cell activation complexes. In patients with hearing loss, T-lymphocyte subpopulations were found to have an increase in cytotoxic T-cells when compared to T-helper, but only for interleukin-2 receptor expression. This difference was significant between patients and the control group. Present findings suggest that T-lymphocyte "early" marker is of particular interest for developing a risk-clinical profile of patients with sensorineural progressive hearing loss of immune origin.

Adolescent↗

PubMed1993

Rodent carcinogenicity and toxicity, in vitro mutagenicity, and their physical chemical determinants.

In this paper, we considered rodent carcinogenicity and toxicity, and four in vitro mutagenicity systems, and we made a global comparison between their different response profiles to a common set of 297 chemicals. This analysis is complemented with a study of the physical chemical properties of active and inactive compounds in the different systems. A clearcut separation between the different classes of toxicological end-points (carcinogenicity, in vivo toxicity, in vitro carcinogenicity) was evident. The observed lack of association between carcinogenicity and toxicity supports the validity of the rodent bioassays; this is contrary to the position that the positive results obtained are due mainly to the use of excessive doses that exert cytotoxic effects. We found substantial consistency in the responses of the in vivo toxicity systems (maximum tolerated dose and LD50), but we also found that remarkable differences exist between the in vitro mutagenicity assay systems. The study of the structure-activity relationships showed that: (a) the hydrophobic-electronic properties of the chemicals influence rodent carcinogenicity, with the tendency of carcinogens to be more electrophilic and more hydrophobic than non-carcinogens; (b) steric effects are implied in in vitro mutagenicity, bulkier molecules being less mutagenic than smaller molecules; (c) no clear association between in vivo toxicity and physical chemical properties was apparent. The differences between carcinogenicity and in vitro mutagenicity may hypothetically be related to their different experimental procedures. The relatively short treatment of in vitro mutagenicity requires that chemicals penetrate easily into the cells, and are well dissolved into the aqueous medium, size and hydrophilicity thus being critical for the action of the chemicals. The size of the molecules is not critical in the long-term rodent carcinogenicity experiments, where other factors, like bioaccumulation (hydrophobicity) and electronic reactivity, become essential.

Animals↗

PubMed1993

Idiopathic progressive sensorineural hearing loss in children.

Clinical observations were made of 42 children with bilateral idiopathic progressive sensorineural hearing loss considering hearing loss distribution in relation to age at onset, audiometric features, audiologic characteristics and possible correlation with some haematochemical alterations. Patients were divided into 2 groups on the basis of hearing onset: Group I, 0-6 years; Group II, 7-14 years. A peak in the distribution of onset age was observed in the range of 4-6 years. In most cases a 'descending' curve was recognized accompanied by recruitment. The haematochemical tests only suggested a possible correlation between hearing loss and anaemia. Finally, no significant difference of incidence between the sexes was observed.

Adolescent↗

PubMed1993

Quantitative structure-activity relationship models correctly predict the toxic and aneuploidizing properties of six halogenated methanes in Aspergillus nidulans.

In a previous study, the relationships between the chemical structure and the ability of 35 chlorinated aliphatic hydrocarbons to induce aneuploidy and toxicity in Aspergillus nidulans were analyzed. Quantitative structure-activity relationships (QSAR) were defined for each of the biological activities under study: ARR (the dose able to block mitotic growth), D37 (the dose with 37% of survival) and LEC (the lowest efficient concentration in aneuploidy induction). In this study, these QSAR equations were used to predict the toxic and genetic activity of a further six chemicals, not included in the previous data base: bromotrichloromethane, bromoform, bromochloromethane, bromodichloromethane, dibromochloromethane and dibromochlorofluoromethane. Their ARR, D37 and LEC values were measured, and were in agreement with the predicted values, with correlation coefficients around 0.99. Furthermore, the QSAR model, which had previously been developed to discriminate between aneugenic and inactive halogenated hydrocarbons, correctly predicted the aneugenic activity of five out of six methanes. These correct predictions confirmed the validity of our QSAR model, according to which the induction of aneuploidy in A. nidulans depends on both the electrophilic and steric properties of the chemicals, whereas toxicity mainly depends on steric factors.

Aneuploidy↗

PubMed1992

The induction of mitotic chromosome malsegregation in Aspergillus nidulans. Quantitative structure activity relationship (OSAR) analysis with chlorinated aliphatic hydrocarbons.

The biological activity of 24 chlorinated aliphatic hydrocarbons has been studied in the mold Aspergillus nidulans. The ability to induce chromosome malsegregation, lethality and mitotic growth arrest has been experimentally determined for each chemical. These data, together with those of 11 related compounds previously investigated, generated a data base which was used for quantitative structure-activity relationship (QSAR) analysis. To this aim, both physico-chemical descriptors and electronic parameters of each compound have been calculated and included in the analysis. The QSAR analysis indicated that toxic effects induced by chlorinated aliphatics in A. nidulans are mainly dependent on steric factors, as indicated by the correlation with molar refractivity (MR). Conversely, the ease with which they accept electrons, parametrized by LUMO (energy of the lowest unoccupied molecular orbital), plays a prevailing role in determining the aneuploidizing properties. An involvement of free radicals, generated by the reductive metabolism of haloalkanes, is hypothesized as an explanation of the data.

Aneuploidy↗

PubMed1992

Electrophilicity as measured by Ke: molecular determinants, relationship with other physical-chemical and quantum mechanical parameters, and ability to predict rodent carcinogenicity.

This paper analyzes electrophilicity data as measured by the Ke system for 205 chemicals including both rodent carcinogens and non-carcinogens. Multivariate statistical methods were used. The analysis identified atoms and substructures contributing to electrophilicity, and permitted to establish a theoretical method by which the Ke value (electrophilicity) of chemicals can be easily estimated. In a subset of chemicals, the Ke parameter was compared with other physical-chemical and quantum mechanical properties: Ke appeared to be mostly correlated with the energy of the lowest unoccupied molecular orbital and with the absolute electronegativity. The role of Ke in structure-activity studies was also investigated; in particular, a comparative analysis of the performance of Ke, Salmonella typhimurium and Ashby's structural alerts in predicting carcinogenicity was carried out. The Ke system performed better than the other systems. However, because of the many different mechanisms underlying carcinogenesis, the Ke system cannot predict the potential carcinogenicity of all kinds of chemicals. It is concluded that the main role of Ke in risk assessment consists in producing a probabilistic estimate of the rodent carcinogenicity of the chemicals: e.g. a chemical with Ke higher than 3.0 x 10(12) M-1S-1 has nearly 80% probability of being a carcinogen. Such a probability estimate can be used to rank the chemicals in a priority scale for subsequent and more detailed studies, either theoretical or experimental. In view of this, the role of our method for estimating Ke is particularly important: it gives rapidly and at no cost a chemical classification for risk assessment and priority setting.

Animals↗

PubMed1992

Pre-surgical treatment of uterine myomas with LH-RH agonists.

Twenty-five non-menopausal women with uterine myomas were treated with LHRH-analogues for 3-6 months. An average reduction of 40% in uterine volume was observed. One patient refused to complete her therapy, three had no more menses after the interruption of treatment, nine underwent myomectomy within four weeks of their final administration, while in 12 cases hysterectomy was performed. In all cases the decrease in uterine volume induced by the analogue allowed a more limited intervention and prevented excessive blood loss.

Administration, Inhalation↗

PubMed1992

[Cervix cerclage. A 20-year case load].

Uterine cervical incompetence is the most common cause of habitual abortion in the second trimester of pregnancy and premature delivery; cervical cerclage still represents the only surgical treatment for cervical incompetence. In the last 20 years (1971-1990) we performed 272 Mac Donald cervical cerclages in patients between the 8th and the 34th week of pregnancy. In 16 cases the outcome of pregnancy is unknown; 198 women (73.3%) subsequentely delivered healthy infants later than 37 weeks' gestation or weighing more than 2500 g.

Abortion, Habitual↗