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Biomedical subjects

E Ferrari

Publications and source records attributed to E Ferrari.

At least 217 records · Page 12Linked to original sources
PubMed1992

[Cardiovascular manifestations of Cogan syndrome. Apropos of a case].

The authors describe a case of Cogan's syndrome in a patient with ulcerative colitis complicated by several cardiovascular manifestations including bilateral coronary ostial stenosis, rapidly progressive aortic regurgitation and aneurysm of the thoracic aorta, thrombosis of the common iliac artery and pericardial symphysis. This rare form of inflammatory arteritis, the diagnosis of which is usually made on the finding of associated ocular and auditory involvement, is distinct from other types of angiitis by the predisposition to severe cardiovascular complications which influence the vital prognosis. The differential diagnosis with more common collagen diseases with cardiovascular complications is discussed.

Adult↗
PubMed1992

Influence of triphasic oral contraceptives on blood rheology and hemostatic and metabolic patterns in young women. Results of a three-year study.

Long-term (three-year) variations in clinical, hemorheologic, hemostatic and blood lipid parameters were evaluated in 20 young healthy women taking a triphasic oral contraceptive. Body weight, arterial blood pressure, whole blood, plasma and serum viscosity, erythrocyte deformability, fibrinogen, fibronectin, alpha-2 macroglobulin, Von Willebrand factor antigen, triglycerides, nonesterified fatty acids, total and low density lipoprotein cholesterol, very low density lipoprotein, low density lipoprotein and apolipoprotein B levels remained unchanged throughout the study. However, high density lipoprotein cholesterol, high density lipoprotein and apolipoprotein A1 serum concentrations increased significantly during treatment. Long-term use of the triphasic oral contraceptive does not seem to adversely affect the blood rheology pattern or vascular endothelium function, which are the main factors responsible for the development of thromboembolic complications.

Adult↗
PubMed1992

Extracellular enzymes: gene regulation and structure function relationship studies.

The first conclusion that one could make from the literature covered in this section is that most single mutations in subtilisin BPN'n do not cause major structural alterations. Even multiple mutations, though they may cause local minor perturbations at each of the altered sites, do not affect the overall structure to a large degree. Bott and Ultsch (1986) observed that the subtilisin BPN' structure is very tolerant of single mutations, and this tolerance may have been necessary for survival of the enzyme during the course of evolution. This structural tolerance is not all that surprising if one considers that the structure of subtilisin Carlsberg is very similar to that of subtilisin BPN' while the protein sequences differ by 31%. A superposition of the 274 alpha-carbon atoms of the two enzymes gives a root mean square (rms) deviation of 0.053 nm, a value indicating significant structural similarity (McPhalen and James 1988). Furthermore, the fungal enzyme proteinase K, which is classified as part of the subtilisin family, has approximately 38-40% sequence homology with bacilli subtilisins, particularly in the catalytic site and substrate-binding regions (Betzel et al. 1988). For these sequence-homology regions there is also a structural similarity indicated by a least squares superposition of alpha-carbons giving an rms deviation of 0.11 nm (Betzel et al. 1988). Thermitase, also a member of the subtilisin family, has 47% sequence homology to subtilisin BPN' (Gros et al. 1989). If the best 203 alpha-carbon atoms are superposed, then an rms deviation of 0.05 nm is obtained (Gros et al. 1989). Apparently a significant amount of sequence variation still allows for overall structural similarities in the subtilisin family of enzymes. Though the overall structure of subtilisin is not easily perturbed by single or even multiple mutations, it is clear from the evidence reviewed here that single mutations can lead to very significant effects on the catalytic efficiency, substrate preference, and stability of the enzyme. Analyzing the structural alterations in subtilisin mutants will lead to an understanding of the molecular effects of the mutations at the atomic level. This understanding enables investigators to model and predict the effects of other substitutions, and allows them to focus their efforts on those mutants that are most likely to have the desired properties.(ABSTRACT TRUNCATED AT 400 WORDS)

Amino Acid Sequence↗
PubMed1992

[Cardiac toxicity of fluoro-uracil. Typical and atypical aspects. Apropos of 8 cases].

The cardiac toxicity of 5 fluoro-uracil, an antimitotic agent widely used in various protocols, has been known for 16 years. Several cases have been reported in the literature, leading to the suggestion, without formal evidence, that the chief mechanism responsible for this cardiac toxicity is "classical" coronary spasm. However, certain clinical aspects already described may shed doubt on this theory. On the basis of 8 cases, the authors report different clinical pictures all caused by cardiac toxicity of 5FU. It is of interest to note that chest pain with the classically described electrocardiographic changes did not apply in the majority of cases. The commonest pattern was asymptomatic electrocardiographic abnormalities and/or arrhythmias without angina. Among the reported cases, one patient had pain with electrocardiographic abnormalities, recurrent after the withdrawal of 5FU and resistant to maximal medical treatment, despite the absence of any coronary disease or signs of spasm. One patient had a first myocardial infarction, later rechallenge with the drug resulting in failure. In another patient, with known coronary disease, 5FU probably cause cardiogenic shock. In total, some of our cases, as well as other features described in the literature, raise questions as to the pathophysiology of the cardiac toxicity of 5FU.

Adult↗
PubMed1992

[An unusual pericardial tumor: bronchogenic cyst].

The authors report the case of an intrapericardial bronchogenic cyst in a 42 year old woman with no cardiac symptoms. Despite extensive investigation, the final diagnosis was made only at anatomopathological examination. A pericardial localisation of this embryological tumour is very rare and a number of features of the condition are described. In this case, the carbohydrate antigen (CA 19-9) was a veritable marker of this tumour. This association, described for the first time, between a simple biological marker and an intrapericardial bronchogenic cyst, could be a valuable diagnostic aid in a pathology in which surgery could reasonably be deferred should the diagnosis of bronchogenic cyst be certain.

Adult↗
PubMed1991

[Idiopathic thrombocytopenic purpura in elderly subjects].

During an 8-year period, 35 patients aged over 60 and presenting with idiopathic thrombocytopenic purpura were observed. At the time of diagnosis, 51.5 percent had haemorrhages which were major in 26 percent of the cases. Response to various treatments, notably corticosteroid therapy, was weak (43 percent). During the course of the disease, 2 patients (5.7 percent) died of cerebral haemorrhage. This series confirms the importance of haemorrhagic syndrome and the resistance to treatment of the elderly as opposed to younger subjects. This is probably due to the heterogeneity of purpura in old age: in a number of patients purpura corresponded to refractory chronic thrombocytopenia or to chronic thrombocytopenia associated with carcinoma.

Adrenal Cortex Hormones↗
PubMed1991

The p15 carboxyl-terminal proteolysis product of the human immunodeficiency virus type 1 reverse transcriptase p66 has DNA polymerase activity.

The reverse transcriptase of human immunodeficiency virus type 1 is a heterodimeric protein consisting of two polypeptides with masses of 66 and 51 kDa and has, as a second enzymatic activity, RNase H activity. The 66-kDa polypeptide can be cleaved by the virus-encoded protease to yield polypeptides of 51 and 15 kDa. The latter has been characterized as possessing RNase H activity [Hansen, J., Schultze, T., Mellert, W. & Moelling, K. (1988) EMBO J. 7, 239-243]. We have purified simultaneously the heterodimeric reverse transcriptase/RNase H containing the 66/51-kDa polypeptides and the 15-kDa RNase H from Escherichia coli containing the expression vector pJS 3.7 by a procedure including chromatography on DEAE-cellulose, phosphocellulose, and heparin-Sepharose. Two RNase H and reverse transcriptase peaks were separated on phosphocellulose, one coinciding with the heterodimeric protein and the other with the 15-kDa protein. On the basis of the following findings it appears that the 15-kDa polypeptide has both RNase H and reverse transcriptase activities: (i) it copurified with both activities; (ii) it functioned as a reverse transcriptase in an in situ assay after SDS/polyacrylamide gel electrophoresis; (iii) polyclonal antibodies raised against the 66-kDa polypeptide reacted in immunoblots exclusively with a 15-kDa polypeptide, reacted in immunoblots exclusively with a 15-kDa polypeptide, while no immunoreactive bands in the range of 51-66 kDa were seen in the 15-kDa polypeptide preparation; (iv) the p15 and the p66/51 reverse transcriptase could be quantitatively pelleted in an enzymatically active form only when antibodies specific for the p66 carboxyl terminus were used; and (v) the p15 protein had bona fide properties of a reverse transcriptase and could enzymatically synthesize a high molecular weight, alkali-resistant product. The two reverse transcriptases appear to have different behaviors on various template/primer systems tested. Conceivably different forms of human immunodeficiency virus type 1 reverse transcriptases might be used in individual steps of (+)- and (-)-strand replication.

Blotting, Western↗
PubMed1991

Biochemical and functional comparison of DNA polymerases alpha, delta, and epsilon from calf thymus.

DNA polymerase alpha, delta and epsilon can be isolated simultaneously from calf thymus. DNA polymerase delta was purified to apparent homogeneity by a four-column procedure including DEAE-Sephacel, phenyl-Sepharose, phosphocellulose, and hydroxylapatite, yielding two polypeptides of 125 and 48 kDa, respectively. On hydroxylapatite DNA polymerase delta can completely be separated from DNA polymerase epsilon. By KCl DNA polymerase delta is eluted first, while addition of potassium phosphate elutes DNA polymerase epsilon. DNA polymerases delta and epsilon could be distinguished from DNA polymerase alpha by their (i) resistance to the monoclonal antibody SJK 132-20, (ii) relative resistance to N2-[p-(n-butyl)phenyl]-2-deoxyguanosine triphosphate and 2-[p-(n-butyl)anilino]-2-deoxyadenosine triphosphate, (iii) presence of a 3'----5' exonuclease, (iv) polypeptide composition, (v) template requirements, (vi) processivities on the homopolymer poly(dA)/oligo(dT12-18), and (vii) lack of primase. The following differences of DNA polymerase delta to DNA polymerase epsilon were evident: (i) the independence of DNA polymerase epsilon to proliferating cell nuclear antigen for processivity, (ii) utilization of deoxy- and ribonucleotide primers, (iii) template requirements in the absence of proliferating cell nuclear antigen, (iv) mode of elution from hydroxylapatite, and (v) sensitivity to d2TTP and to dimethyl sulfoxide. Both enzymes contain a 3'----5' exonuclease, but are devoid of endonuclease, RNase H, DNA helicase, DNA dependent ATPase, DNA primase, and poly(ADP-ribose) polymerase. DNA polymerase delta is 100-150 fold dependent on proliferating cell nuclear antigen for activity and processivity on poly(dA)/oligo(dT12-18) at base ratios between 1:1 to 100:1. The activity of DNA polymerase delta requires an acidic pH of 6.5 and is also found on poly(dT)/oligo(dA12-18) and on poly(dT)/oligo(A12-18) but not on 10 other templates tested. All three DNA polymerases can be classified according to the revised nomenclature for eukaryotic DNA polymerases (Burgers, P.M. J., Bambara, R. A., Campbell, J. L., Chang, L. M. S., Downey, K. M., Hübscher, U., Lee, M. Y. W. T., Linn, S. M., So, A. G., and Spadari, S. (1990) Eur. J. Biochem. 191, 617-618).

Animals↗
PubMed1991

[Influence of sex hormones on hemorrheology and plasma proteins during the menstrual cycle].

Our study was undertaken to verify the relation among sex hormone profile, hemorheologic pattern, blood lipids and plasma proteins throughout the menstrual cycle. In effect, the estrogenic activity has been related to blood hypercoagulability, thromboembolic disorders and to cardiovascular complications in normal women and in several diseases. The protocol study concerns 15 healthy young women (mean age 25 years), with normal body weight, investigated on day 7 (follicular phase), day 14 (ovulatory phase), and days 21, 25, 27 (mid-and late luteal phase) of menstrual cycle. We evaluated: blood, plasma and serum viscosity (at shear-rate of 450; 90; 4.5; 2.25 s-1), erythrocyte deformability, haematocrit, plasma fibrinogen and fibronectin, apolipoprotein A-A1-B, triglycerides, total-HDL and LDL-cholesterol, FSH, LH, 17-beta-estradiol, progesterone, testosterone, androstenedione, DHEA, DHEA-sulfate and the estradiol/progesterone ratio (E2/P ratio). Higher blood, serum and plasma viscosity (p less than 0.01), and lower erythrocyte deformability (p less than 0.01) were demonstrated during follicular and ovulatory phase, than in mid- and late luteal phases of menstrual cycle. Plasma fibrinogen (p less than 0.01) and fibronectin (p less than 0.001) were also significantly increased in ovulatory and follicular phases; whereas haematocrit, blood lipids and apolipoproteins remained unchanged throughout the menstrual cycle. Positive correlations among E2/P ratio, plasma viscosity, fibrinogen and fibronectin, and negative correlations between E2/P ratio and erythrocyte deformability, were found on day 21 (p less than 0.05) and day 25 (p less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗