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Biomedical subjects

M Crippa

Publications and source records attributed to M Crippa.

At least 19 recordsLinked to original sources
PubMed1992

[Plasma-erythrocyte viscosity and evaluation of several pro- and anti-aggregating factors in NIDDM patients in metabolic decompensation state].

In NIDDM diabetic subjects, the microcirculatory damage shows a double aspect: an alteration of the vascular wall, particularly of the arteriolar capillary, and a hemorheological alteration at the level of the capillary district. In the microcirculation, because of the low velocity of the flow and the inverse relationship between capillary size and RBC diameter, the viscosity has an important role with its components: RBC viscosity and deformability. Even the erythrocyte aggregation has a key role as resultant of the attracting and repulsing forces, among which the plasma-RBC viscosity and the deformability play opposite role. Our method allows to evaluate the erythrocyte, the whole blood, the plasma and the plasma-RBC viscosity, and the deformability. Studies from this laboratory in NIDDM subjects show an increase in the blood viscosity, a decrease in the erythrocyte deformability and plasma-RBC viscosity. It is suggested that in microcirculatory district the flow reductions are particularly of hemorheological type and that the sludged blood is an "optical" phenomenon with poor meaning. We consider some hematological parameters, namely the Hgb A1c %, Hgb concentration, RBC count, MCV, etcetera.

Aged↗
PubMed1992

[Relations between plasma-erythrocyte viscosity factors and ESR].

The ESR is usually put in relationship: to the real density of the RBCs (erythrocytes) (difference between the RBC specific gravity and the plasma one), and to the resistance that the RBCs meet moving in a medium, which is due to the plasma viscosity and to the total external RBC surface. When the RBCs take shape of aggregates, their external surface is decreased and ESR increases. The most important plasma factor causing changes in ESR is the fibrinogen level followed by the plasma globulins and by the products arising from the tissue damage. The resistance that the RBCs meet moving in the plasma is well expressed by the measurement of the plasma-RBC viscosity considering that is inclusive of both factors that are the plasma viscosity and the external RBC surface. The plasma-RBC viscosity is the resultant of several factors: Fa = Fb - Fe - Fs - Fm, were: Fa is the resultant, Fb the attracting forces due to the proteic macromolecules, Fe the repulsing forces due the negative charges. Fs the repulsing forces due to the shear-stress, Fm the force which opposes itself against the surface tension of the aggregation; it depends on the RBC morphology and on the RBC rigidity. The ESR has been recently used like an index of the RBC aggregation. The Authors study the relationship between several hemorheological parameters and the ESR in infective and inflammatory processes.(ABSTRACT TRUNCATED AT 250 WORDS)

Blood Sedimentation↗
PubMed1991

Activity of doxorubicin and cisplatin combination chemotherapy in patients with diffuse malignant pleural mesothelioma. An Italian Lung Cancer Task Force (FONICAP) Phase II study.

Twenty-six symptomatic patients with diffuse malignant pleural mesothelioma (DMPM) were enrolled in a Phase II Italian Lung Cancer Task Force (FONICAP) study to assess the activity and toxicity of doxorubicin and cisplatin combination chemotherapy. The drug schedule was as follows; 60 mg/m2 of doxorubicin and 60 mg/m2 of cisplatin both given intravenously (IV) on day 1 every 3 to 4 weeks. Of the 24 evaluable patients, 6 objective partial responses (25%; 95% confidence limits, 9.77% to 46.71%) were observed. Twelve of 24 patients (50%), including 6 with no radiologic evidence of response, had a clinical improvement as demonstrated by an objective reduction of symptom or performance status scores along treatment. The overall median survival time was 10 months. Toxicity was mild and dose reductions or suspensions were not required. The combination of doxorubicin and cisplatin is effective and well tolerated. It might be considered for palliation of symptomatic patients with DMPM.

Adult↗
PubMed1991

Cor triatriatum. Clinical presentation and operative results.

From November 1973 to January 1988, 15 patients with cor triatriatum underwent surgical correction at the Department of Cardiac Surgery, Ospedali Riuniti, Bergamo, Italy. Their ages ranged from 15 days to 48 years. Eight patients (53%) were younger than age 1 year. Evidence of congestive heart failure was present in five infants, whereas three infants, three children, and two adults initially had signs of pulmonary venous obstruction, and two children had a heart murmur only. Five patients had cor triatriatum alone; in ten cases there also was an atrial septal defect. Associated anomalies in four patients included left superior vena cava, ventricular septal defect and left superior vena cava, partial anomalous pulmonary venous connection, and bilateral partial anomalous pulmonary venous connection. Cor triatriatum was repaired with the aid of cardiopulmonary bypass in all patients. Excision of the membrane was accomplished with a right atrial approach in 13 patients and a left atriotomy in one patient. Both atria were opened in one case. All associated anomalies were simultaneously corrected. Three patients (20%) died early after operation. Among the 12 survivors, no late events have occurred, and all of them are presently in New York Heart Association functional class I. A recent echocardiogram shows absence of residual obstruction or shunt and good development of the left cardiac chambers.

Adolescent↗
PubMed1991

[Sulfonylurea resistance in type II diabetes mellitus. Assessment of metabolic and hormonal aspects].

Sensitivity tests to SU allow two populations to be distinguished. One contains severely diabetic subjects in a continuous state of metabolic precariousness with reduced alkaline reserves, hyperinsulinemia and insulin resistance; the other contains mildly diabetic subjects who are normoinsulemic and show no insulin-resistance to i.v. tests irrespective of the presence of a similar level of SU resistance. While the first group may be more readily interpreted, especially with reference to the dualism between the alterations of insulin synthesis and resistance of peripheral tissues, with special reference to the function of receptors and post-receptors, the second group raises numerous questions of interpretation. The test becomes important to identify those subjects who right from the start show a reduced insulin secretion to drug stimulation and the possibility of obtaining euglycemia with high doses of SU. This finding suggests the existence of a genetically determined mechanism for SU resistance: in addition to the population who show marked SU resistance from the onset of diabetic symptoms, there is also a group of subjects in whom this resistance is less evident and may be provoked only by certain stimuli or spontaneously under stress, or by the appearance of the triggering metabolic factor. It is clearly important to identify the latter population before the clinical manifestation of symptoms so as to establish the correct therapy or combined therapy. This led us to consider the SU-resistant cases in the series of patients studied as being two clinical stages of the same condition rather than two separate populations with different pathogenesis.

Aged↗
PubMed1990

[Assessment of exposure to polycyclic aromatic hydrocarbons in 3 work activities using mineral oils].

The exposure to polycyclic aromatic hydrocarbons (PAH) in different industries using cutting, hardening and extruding oils, was investigated determining their concentration in oils and in environmental samples. The following compounds: phenanthrene, anthracene, fluoranthene, pyrene, benzo-a-anthracene, chrysene, triphenylene, benzo-a-pyrene, benzo-e-pyrene and perylene were evaluated by means of gas-chromatography-mass spectrometry. PAH concentrations in oils ranged from 652 to 4461 ng/gr and environmental concentrations from 63.86 to 120.54 ng/mc. In particular the BaP concentrations varied from 0.73 to 1.9 ng/mc. These results, compared with those measured in other environmental surveys and with the limit values proposed in various countries, point out the existence of a very low inhalatory risk of PAH.

Air Pollutants, Occupational↗
PubMed1989

[Qualitative and quantitative changes in the polycyclic aromatic hydrocarbons in cutting oils after their use].

The quantitative and qualitative variations in the mixture of polycyclic aromatic hydrocarbons (PAH) present in different samples of a cutting oil, unused and after 3,6 and 9 months of use, were evaluated by means of gas-chromatography mass spectrometry. Nine of the identified hydrocarbons (phenanthrene, anthracene, fluoranthene, pyrene, benzo-a-anthracene, chrysene, triphenylene, benzo-a-pyrene, benzo-e-pyrene and perylene) were studied. The total PAH concentration increased from 45 (first sample) to 915 ng/gr of oil, even if a different behaviour for various hydrocarbons was shown. In fact some of them, such as phenanthrene and anthracene increased with use, some, such as fluoranthene and pyrene decreased and the other did not exhibit a regular trend. In the light of results, the influence of variations of the PAH mixture in oil on the PAH air concentration and on the preventive measures to be adopted, is discussed.

Gas Chromatography-Mass Spectrometry↗
PubMed1979

Transcription of spacer sequences in genes coding for ribosomal RNA in Xenopus cells.

Untreated Xenopus cells synthesize RNA is increased and some sequences complementary to those of the nontranscribed spacer are found in the heavy shoulder of the 40S precursor rRNA peak. In such events transcription initiation seems to take place within the spacer because its middle and right BamHI endonuclease fragments are preferentially transcribed, whereas only few RNA sequences complementary to the left spacer fragment are found. It is concluded that at least some spacer regions contain promoters for transcription and can be transcribed either into a special class of "spacer transcripts" or into molecules covalently linked to rRNA precursor.

Animals↗
PubMed1978

Large scale isolation of nuclei and nucleoli from vitellogenic oocytes of Xenopus laevis.

A new method is described which allows the purification of large quantities of nuclei (germinal vesicles) from Xenopus laevis vitellogenic oocytes of different developmental stages. From the isolated nuclei, purified nucleoli were obtained. The isolated germinal vesicles are transcriptionally active showing endogenous RNA polymerase activity as well as a high level of activity with an exogenously added template.

Animals↗
PubMed1978

Translation "in vitro" of globin mRNA from Xenopus laevis.

RNA isolated from Xenopus laevis reticulocytes and characterized as globin mRNA (Meza et al., 1978) was tested for its capacity to stimulate "in vitro" a wheat germ translation system, and the ability to synthesize a polypeptide. The latter was identified as globin by its electrophoretic mobility and immunoprecipitation with antiglobin antibody.

Animals↗
PubMed1978

Characterization of globin mRNA from Xenopus laevis.

A 9S polyadenylated mRNA was isolated from 'xenopus laevis reticulocytes and purified by sedimentation and oligo-dT-cellulose chromatography. The size of this RNA estimated in denaturing agarose gels was 2.2 x 10(5) daltons. 9S polyadenylated mRNA hydridized to total DNA with a Cot1/2 of 3.8 x 10(3).

Animals↗