Biomedical subjects

R Bianchi

Publications and source records attributed to R Bianchi.

At least 199 records · Page 11Linked to original sources

PubMed1991

[Experience of the National Autonomous Board for Certification of Medical Specialties].

After 6 years of operation of a National (autonomous) Board for Certification of Medical Specialists, the number, distribution and training of medical specialists is analyzed. Problems regarding significant differences in the quality of training and imbalance among different specialties are identified. The medical profession has expressed its confidence and feels supported by the activities of the Board. However, health care deliverers and users in general are expected to increase their support and consideration for the information provided by the Board, in order to fulfill the purpose for which it was established.

Chile↗

PubMed1990

Characterization of mammalian heart annexins with special reference to CaBP33 (annexin V).

Porcine heart was observed to express annexins V (CaBP33) and VI in large amounts, and annexins III and IV in much smaller amounts. Annexin V (CaBP33) in porcine heart was examined in detail by immunochemistry. Homogenization and further processing of heart in the presence of EGTA resulted in the recovery of annexin V (CaBP33) in the cytosolic fraction and in an EGTA-resistant, Triton X-100-soluble fraction from cardiac membranes. Including Ca2+ in the homogenization medium resulted in a significant decrease in the annexin V (CaBP33) content of the cytosolic fraction with concomitant increase in the content of this protein in myofibrils, mitochrondria, the sarcoplasmic reticulum and the sarcolemma. The amount of annexin V (CaBP33) in each of these subfractions depended on the free Ca2+ concentration in the homogenizing medium. At the lowest free Ca2+ concentration tested, 0.8 microM, only the sarcolemma appeared to contain bound annexin V (CaBP33). Membrane-bound annexins V (CaBP33) and VI partitioned in two fractions, one EGTA-resistant and Triton X-100-extractable, and one Triton X-100-resistant and EGTA-extractable. Altogether, these data suggest that annexins V and VI are involved in the regulation of membrane-related processes.

Animals↗

PubMed1990

T-cell subsets, IFN-gamma production and efferent specificity in anti-parental tumor immunity induced by mouse sensitization with xenogenized variant cells.

In addition to previous evidence for a role of L3T4+ T cells in the protective anti-parental tumor immunity induced by xenogenized variant cells of a murine lymphoma (L5178Y/DTIC), we have investigated the possible participation in this effect of L5178Y tumor-specific lymphocytes of the Lyt-2+ T cell subset. Spleen cells from L5178Y/DTIC tumor-immunized mice produced high levels of IFN-gamma in vitro in response to parental antigens, and this activity was only abolished by treating the responder population with anti-Thy-1.2 antibody or a combination of anti-L3T4 and anti-Lyt-2.2 monoclonal antibodies (MAbs) plus complement. Positively selected L3T4+ and Lyt-2+ cells also produced IFN-gamma in vitro, provided accessory cells (plastic-adherent and Thy-1- Ia- splenocytes, respectively) were added to the lymphocyte-tumor cell cocultures. The production of IFN-gamma by purified L3T4+ and Lyt-2+ cells was inhibited by addition of the respective anti-class-II and anti-class-I H-2 antibody to the cultures. Administration of anti-IFN-gamma MAb in vivo significantly impaired the resistance of L5178Y/DTIC-immune mice to challenge with parental cells, as manifested by survival criteria and increased tumor-cell proliferation in the spleens of antibody-treated mice. Although anti-parental tumor protection in vivo and T-cell activation in vitro for IFN-gamma production were strictly antigen-specific, bystander tumor inhibition was observed when antigenically irrelevant cells were inoculated with the L5178Y lymphoma. These results suggest that both L3T4+ and Lyt-2+ T cells play a role in the protective anti-parental tumor immunity induced by xenogenized cells, and that their activity may involve IFN-gamma-mediated stimulation of non-specific tumoricidal mechanisms.

Animals↗

PubMed1990

Interaction of two brain annexins, CaBP33 and CaBP37, with membrane-skeleton proteins.

CaPB33 and CaPB37, two annexins purified from bovine brain, interact with a Triton X-100-resistant fraction (cytoskeleton) from bovine brain membranes in a Ca2(+)-dependent way in vitro. The binding is saturable with respect to the CaBP33-CaBP37 concentration, half-maximal binding occurring at approximately 15 micrograms of the CaBP33-CaBP37 mixture/ml. The binding of these two annexins to the crude cytoskeleton preparation as a function of free Ca2+ concentration is biphasic, with half-maximal binding at approximately 50 microM and approximately 400 microM free Ca2+ for the first and the second component, respectively. By an overlay technique, CaBP33 and CaBP37 bind to a set of low Mr polypeptides (10-20 kDa) in the crude cytoskeleton preparation, with formation of an 85-90 kDa complex as investigated in cross-linking experiments. No binding of the CaBP33-CaBP37 mixture to either G- or F-actin has been observed. Identification of the CaBP33-CaBP37-binding proteins in cytoskeletons would help elucidating the function(s) of these annexins in the brain.

Animals↗

PubMed1990

Two novel brain proteins, CaBP33 and CaBP37, are calcium-dependent phospholipid- and membrane-binding proteins.

Two acidic Ca2(+)-binding proteins (CaBP33 and CaBP37) purified from bovine brain have been characterized in terms of immunological properties, heat-sensitivity, electrophoretic mobility, and Ca2(+)-dependent binding to negatively charged phospholipids and to brain membranes. They were induced to bind to membranes by homogenization of brain tissue in the presence of CaCl2. The membrane-bound CaBP33/CaBP37 mixture resisted extraction with detergents and was solubilized with high concentrations of EGTA/KCl. However, apparent Ca2(+)-independent binding of the two proteins to membranes seemed to occur as well. This latter fraction of membrane-bound CaBP33 and CaBP37 could be solubilized with Triton X-100, indicating that brain membranes normally contain the two proteins as intrinsic components.

Animals↗

PubMed1990

Ultrastructure of substance P immunoreactive elements in the periaqueductal gray matter of the rat.

Substance P (SP) is a non-opioid peptide that generates a potent analgesia when injected into the periaqueductal gray matter (PAG). The aim of this study was to investigate the fine neuronal structures and synaptic circuits involved in SP action in rats by means of electron microscopy, using immunocytochemical (ICC) pre-embedding methods. A conventional ultrastructural study, carried out to interpret the ICC data correctly, shows small sized nerve cell bodies with a high nucleus-cytoplasmic ratio; absence of an extensive granular endoplasmic reticulum; and few axo-somatic contacts having symmetrical and asymmetrical junctions in equal proportions. The large neuropil is characterized by numerous thin unmyelinated axons and axo-dendritic synapses mainly showing pleomorphic vesicles and asymmetrical junctions. The ICC analysis showed moderately labeled nerve cell bodies with the same structural, synaptic, and dimensional features as the negative cells. In the neuropil SP immunoreactivity is shown by dendrites, synapses, and thin elements which are unidentifiable structurally. No SP terminals synapsing on SP nerve cell bodies were found and only occasional SP light labeled terminals synapsing on negative perikarya were seen. The SP boutons generally have pleomorphic vesicles and asymmetrical junctions. On the basis of these data a possible excitatory activity of PAG SP synapses could be hypothesized. This activity would take place on postsynaptic neurons generally at a dendritic level. Our ultrastructural findings give support to an excitatory role carried out by SP neurons of the PAG, as suggested by the role of PAG circuitry on spinal nociception.

Animals↗

PubMed1990

Effects of dopamine, D-1 and D-2 dopaminergic agonists on the excitability of hippocampal CA1 pyramidal cells in guinea pig.

In hippocampal pyramidal cells (HPCs), Dopamine (DA) application (1 microM) produced, in 50% of recorded cells, an hyperpolarization of the resting membrane potential (r.m.p.) and an increase of the afterhyperpolarization (AHP) amplitude and duration in 79% of recorded cells. DA-induced effects on both the r.m.p. and AHP were mimicked by bath application of a D-1 selective agonist, SKF 38393 (20 microM). In addition, we have observed that a D-1 selective antagonist such as SCH 23390 (1 microM) abolished the action of both DA and SKF 38393. In contrast, the activation of D-2 receptors through LY 171555 (10 microns) produced, in 50% of cells, a depolarization of the r.m.p. and a depression of the AHP in 67% of recorded cells. These results suggest that the effects observed in hippocampal pyramidal neurons after DA application of micromolar concentration are mediated by D-1 subtype of receptors.

2,3,4,5-Tetrahydro-7,8-dihydroxy-1-phenyl-1H-3-ben↗

PubMed1990

Diabetic neuropathy in db/db mice develops independently of changes in ATPase and aldose reductase. A biochemical and immunohistochemical study.

ATPase activity was investigated in sciatic and optic nerves of female mutant diabetic C57Bl/Ks (db/db) mice and age-matched control mice (db/m and m/m). Nerves from animals aged 50, 70, 125, 180 and 280 days were assayed in vitro for ATPase activity in the presence or absence of ouabain: the ouabain-sensitive fraction contained Na+,K(+)-ATPase. Enzymatic activity was compared within and between age-matched groups. No significant difference in Na+,K(+)-ATPase activity was detected between the diabetic and control mice, whether expressed as mumol Pi/h-1 formed per gramme wet weight or per nerve (protein content). The activity decreased by about 25% in both the sciatic and optic nerves of the oldest animals. These results were strikingly similar in all groups, regardless of the type of nerve examined, confirming that the development of neuropathy in this animal model is unrelated to the postulated derangement of Na+,K(+)-ATPase activity. Among possible explanations, a lack of polyol pathway activation was investigated by staining the sciatic nerves of animals from all groups with the peroxidase-antiperoxidase procedure using a polyclonal antiserum raised against the enzyme aldose reductase. Histological sections of all nerves were consistently negative, suggesting that these animals actually lack the enzyme involved in activating the self-perpetuating metabolic cycle leading to deranged nerve function. The db/db mouse appears to present particular biochemical changes which merit attention with a view to clarifying the pathogenesis of diabetic neuropathy.

Adenosine Triphosphatases↗

PubMed1990

The characterization of plasma-modified polydimethylsiloxane interfaces with media of different surface energy.

The effect of interfacing fresh pig blood with polydimethylsiloxane (PDMS) samples of different surface energies and chemistries is presented. PDMS-treated surfaces were obtained using oxygen plasmas. Aging in air produced rather hydrophobic surfaces, although less hydrophobic than the untreated one, due to hydrophobic recovery. Aging in water hindered it, therefore the surface remained hydrophilic. The concentration of albumin and fibrinogen was measured as a function of contact time with fresh pig blood with untreated, treated and aged in air, and treated and aged in water surfaces. The albumin concentration changed in a constant fashion. Fibrinogen depletion was observed for both treated surfaces. In the case of most hydrophobic surface a 'passivating layer' was formed. The same effect was not possible for the hydrophilic surface, due to the low albumin/fibrinogen-treated surface fracture energy.

Animals↗

PubMed1990

Thyroidal and peripheral production of 3,5,3'-triiodothyronine in humans by multicompartmental analysis.

Multicompartmental analysis of thyroxine (T4) and 3,5,3'-triiodothyronine (T3) kinetics based on the plasma disappearance curves of the two tracer hormones (J. J. DiStefano III, M. Jang, T. K. Malone, and M. Broutman. Endocrinology 110: 198-213, 1982 and J. J. DiStefano III, T. K. Malone, and M. Jang. Endocrinology 111: 108-117, 1982) was extended to include additional experimental data, namely, the appearance curve in plasma of labeled T3 generated in vivo from precursor T4. Kinetic analysis of data obtained in 14 studies carried out in normal subjects by using a composite six-pool model made it possible to quantify the contributions of the thyroid (3.3 micrograms.day-1.m-2) and the periphery (12.7 micrograms.day-1.m-2) to T3 production. T4 monodeiodination occurred mainly in peripheral tissues rapidly exchanging with plasma (10.7 micrograms T3.day-1.m-2), whereas only 2.0 micrograms T3.day-1.m-2 arose in slowly exchanging tissues. In contrast, if plasma disappearance curves only were analyzed, a value of 10.9 micrograms T3.day-1.m-2 was calculated for peripheral conversion in slowly exchanging tissues; this underscores the need for additional data, such as the [125I]T3 plasma appearance curve for the partition of central and peripheral production of T3.

Adult↗

PubMed1990

Correction of altered metabolic activities in sciatic nerves of streptozocin-induced diabetic rats. Effect of ganglioside treatment.

The effect of ganglioside administration to nondiabetic and streptozocin-induced diabetic rats on sciatic nerve Na(+)-K(+)-ATPase, polyphosphoinositide (PPI) turnover, and protein phosphorylation was investigated. Gangliosides were injected (10 mg/kg body wt i.p.) for 10 or 30 days beginning 20 days after induction of diabetes. Na(+)-K(+)-ATPase activity was reduced nearly 50% in diabetic nerve and was restored to normal by both ganglioside treatments. The elevated levels of fructose and sorbitol and depressed content of myoinositol in diabetic nerve were unaffected by 30 days of ganglioside treatment, indicating that the restoration of Na(+)-K(+)-ATPase activity is not dependent on normal concentrations of these compounds. In the same nerves, 32P incorporation into phosphatidylinositol 4,5-bisphosphate and phosphatidylinositol 4-phosphate increased 73-76 and 39-53%, respectively, in diabetic compared with nondiabetic tissue. Ganglioside administration abolished the elevated labeling of PPIs after 30 days but was ineffective after only 10 days. Neither ganglioside regimen was able to reverse enhanced phosphorylation of the major peripheral nerve myelin protein P0. The finding that gangliosides can more quickly correct the effects of diabetes on Na(+)-K(+)-ATPase activity than on PPI turnover suggests that the mechanisms underlying these two phenomena are not closely related and are distinct from the sequence of events responsible for altered myelin protein phosphorylation.

Animals↗

PubMed1990

CAM26, CAM29 and mucin-like carcinoma associated antigen in epithelial ovarian cancer.

The levels of CA125 (reference values [RVs] 35 U/mL and 65 U/mL), CA15.3 (RV = 32 U/mL), Mucin-like carcinoma associated antigen (MCA; RV = 15 U/mL), CAM26 (RV = 75 U/mL) and CAM29 (RV = 15 U/mL) were preoperatively assayed in blood samples drawn from 42 patients with ovarian carcinoma and 101 patients with benign ovarian pathology undergoing laparotomy at the Department of Gynecology and Obstetrics of the University of Pisa. With 65 U/mL as RV, CA125 had a sensitivity (SE) of 80.9% and a specificity (SP) of 89.1% for ovarian carcinoma; with 35 U/mL as RV, CA125 had a SE of 85.7% and a SP of 66.3%; CA15.3 had a SE of 57.1% and a SP of 96.0%; MCA had a SE of 59.5% and a SP 86.1%; CAM26 had a SE of 21.4% and a SP of 96.0%, CAM29 had a SE of 64.3% and a SP of 97.0%. The association of CA125 with each of other antigens did not improve the SE of CA125 assay alone in the detection of patients with ovarian carcinoma. In conclusion, the present data showed that the measurement of CA15.3, MCA and CAM26 did not give any additional information with respect to CA125 assay in the diagnosis of ovarian carcinoma. The good SE and the very good SP and diagnostic accuracy of CAM29 could suggest further investigation in order to evaluate the role of this antigen in the management of patients with this malignancy.

Adenocarcinoma↗

PubMed1990

Accessory oculomotor nuclei of man. 1. The nucleus of Darkschewitsch: a Nissl and Golgi study.

A morphoquantitative study was carried out to provide detailed information regarding the cytoarchitecture and neuronal morphology of the nucleus of Darkschewitsch (ND) of man. The neuronal population showed heterogeneity of shape and size of the nerve cell bodies. Small and medium-sized neurons appeared scattered in a wide neuropil. In the Golgi material, two types of neurons were identified: multipolar and fusiform cells. Multipolar cells, which were the most numerous (77%), had 3-5 dendrites giving off primary bifurcations at a short distance from the nerve cell body. Sometimes dendrites and axons were seen to spread outside the ND. The fusiform cells had 1-2 dendrites emerging from the opposite poles of the elongated nerve cell bodies. The dendrites tended to run unbranched for long distances in the section plane before dichotomizing. The dendrites and axons of the fusiform cells always lay inside the ND. The cytoarchitectural features of the ND corresponded to the characters of the reticular formation so that the ND of man could be considered to be a typical reticular nucleus inside the central gray matter. The prevailing presence of multipolar neurons whose processes often spread outside the ND could suggest that the ND is a mainly projective nucleus.

Adult↗

PubMed1990

An ultrastructural stereologic study of mitochondria in the neonatal adrenal cortex of the rat.

The ultrastructural changes observed during the neonatal period of the rat adrenal cortex are described. The zona juxta-medullaris cells presented round mitochondria with vesicular cristae and large endoplasmic reticulum. Variations on the surface of the mitochondrial cristae were determined by morphometric methods. The cortical cells of 1 and 10-days-old rats showed a well developed endoplasmic reticulum. Morphological analysis indicate that the number of mitochondrial cristae increase the third day, followed by a decrease. At the tenth day a second increase was observed. Plasma corticosterone was also measured. The highest levels of this hormone were found in the 1, 2 and 10-days-old rats. A decrease was observed in rats of 3 to 8 days of age. This result is coincident with the adrenal changes observed in the developing of mitochondria and endoplasmic reticulum in the neonatal period. The increase in the number of mitochondrial cristae in the three-days old rats can be considered a morphological expression of the neonatal gland in the period influenced by maternal dependence. The most important morphological and metabolic changes observed the second week of life are probably due to the maturation of the hypothalamic pituitary axis that stimulates the neonatal adrenal cortex secretion, which is independent of maternal dependence.

Adrenal Cortex↗

PubMed1990

The spinal terminals into the midbrain periaqueductal gray of the rat. A light and electron microscope study of the projections ascending via the ventro-lateral funiculus.

Light and electron microscope studies of the terminal fields of the spinal afferents ascending in the ventrolateral quadrant of the spinal cord to the periaqueductal gray matter (PAG) were carried out using silver degeneration techniques and anterograde WGA-HRP transport. At all mesencephalic levels the terminal degeneration and the labelling of the spinal fibres to the PAG were fairly dense, mainly concentrated in the outer part of the annular ring. At the electron microscope, the spinal nerve terminals were found ending almost exclusively in the neuropil, impinging on small dendritic profiles. The majority of these synaptic contacts were of the asymmetrical type and contained a prevalence of round vesicles. This study provides an accurate representation of the terminal domain of the spino-PAG afferents and gives the conclusive anatomical evidence that the fibres ascending in the ventro-lateral funiculus of the spinal cord do not simply pass through the PAG, but actually terminate in it, synapsing in the neuropil.

Animals↗

PubMed1990

A comparison of pretreatment serum levels of four tumor markers in patients with endometrial and cervical carcinoma.

CA125 (reference value [RV] = 35 U/mL), CA50 (RV = 20 U/mL), CA72.4 (RV = 3.8 U/mL) and SCC (RV = 3.6 ng/mL) levels were retrospectively assayed in blood samples collected at diagnosis from 42 patients with endometrial carcinoma, 45 patients with cervical carcinoma and 68 patients with benign uterine pathology as controls. Among the patients with endometrial carcinoma. CA50 was the antigen with the highest sensitivity (SE) (34.4%) followed by CA125 (26.2%), CA72.4 (21.9%) and SCC (16.7%). The incidence of elevated serum CA125 and CA72.4 levels was significantly greater in advanced stages than in early ones (66.7% vs 19.4%, p = 0.032 for CA125; 66.7% vs 11.5%, p = 0.012 for CA72.4), while CA50 positivity was not significantly correlated with the extent of disease (50% in advanced stages vs 30.8% in early ones, p = 0.38). Among the patients with cervical carcinoma, CA125 and CA50 respectively showed a SE of 33.3% and of 42.9% for adenocarcinoma, while SCC had a SE of 33.3% and of 42.9% for squamous cell adenocarcinoma; in particular among the patients with squamous cell carcinoma, the incidence of elevated SCC levels was correlated with the extent of tumor (57.1% in advanced stages vs 12.5% in early ones, p = 0.013). In conclusion, CA50 and CA125 were the most sensitive tumor markers in both endometrial carcinoma and cervical adenocarcinoma, while SCC was the most reliable antigen for squamous cell carcinoma of the cervix. Because of the affinity of SCC, CA50 and CA125 for different histological types of cervical carcinoma, the combined evaluation of SCC with CA50 or CA125 showed an increased SE with respect to each marker alone.

Adenocarcinoma↗

PubMed1990

A comparison of the usefulness of serum measurements of CA 125, CA 50 and TATI in patients with malignant and benign gynecological pathology.

CA 125, CA 50 and Tumor Associated Trypsin Inhibitor (TATI) levels were assayed in blood samples drawn at diagnosis from 149 patients with malignant or benign gynecological pathology. CA 125 serum levels greater than 35 U/ml and 65 U/ml were respectively found in 34/38 (89.5%) and in 33/38 (86.8%) patients with ovarian carcinoma, in 17/61 (27.9%) and in 6/61 (9.8%) with benign ovarian pathology, in 6/30 (20.0%) and in 1/30 (3.3%) with cervical carcinoma, in 6/20 (30.0%) and in 6/20 (30.0%) with endometrial carcinoma. TATI serum levels greater than 22 ng/ml were observed in 17/38 (44.7%) patients with ovarian carcinoma, in 3/61 (4.9%) with benign ovarian pathology, in 1/30 (3.3%) with cervical carcinoma and in 3/20 (15.0%) with endometrial carcinoma. CA 50 serum levels greater than 20 U/ml were found in 11/38 (28.9%) patients with ovarian carcinoma, in 19/61 (31.1%) with benign ovarian pathology, in 7/30 (23.3%) with cervical carcinoma and in 6/20 (30%) with endometrial carcinoma. This study confirmed that CA 125 is the most reliable marker for ovarian carcinoma; however TATI could have a role in the diagnostic evaluation of adnexal masses, because of its very good specificity, CA 125 and CA 50, but not TATI, could be of some benefit in the management of endometrial and cervical carcinoma.

Antigens, Tumor-Associated, Carbohydrate↗

PubMed1990

A comparative evaluation of the ability of serum CA 125, CA 19-9, CA 15-3, CA 50, CA 72-4 and TATI assays in reflecting the course of disease in patients with ovarian carcinoma.

The Authors compared the ability of serum CA 125, CA 19-9, CA 15-3, CA 50, CA 72-4 and Tumor-Associated Trypsin Inhibitor (TATI) assays in reflecting the disease course in a group of 27 patients with ovarian carcinoma. Before initial surgery, elevated levels of CA 125 (greater than 65 U/ml) were found in 27 patients, of CA 19-9 (greater than 40 U/ml) in 7, of CA 15-3 (greater than 32 U/ml) in 17, of CA 50 (greater than 20 U/ml) in 7, of CA 72-4 (greater than 3.8 U/ml) in 20, and of TATI (greater than 22 ng/ml) in 13. For each marker, only patients with elevated antigen levels at diagnosis were considered. CA 125, CA 19-9, CA 15-3, CA 50, CA 72-4 and TATI levels correlated with disease regression, stability or progression in 123/147 (83.7%), 24/34 (70.6%), 57/87 (65.5%), 26/38 (68.4%), 87/120 (72.5%), 33/75 (44.0%) instances respectively. Alterations in CA 125 levels correlated with disease status better than alterations in each other antigen levels. However serial measurement of the other tumor markers could be of help in the monitoring of patients with normal CA 125 values before initial surgery.

Antigens, Tumor-Associated, Carbohydrate↗