Biomedical subjects

M Bianchi

Publications and source records attributed to M Bianchi.

At least 91 records · Page 5Linked to original sources

PubMed1999

Ultrasonic videodensitometric analysis of myocardium in end-stage renal disease treated with haemodialysis.

BACKGROUND: The aim of this study was to investigate videodensitometric parameters of the myocardium, in dialysis patients, who represent a complex pathophysiological model of pressure volume overload, and in essential hypertensive patients with the same level of left ventricular mass. METHODS: We compared a group of male dialysis patients (D) with two groups: hypertensive patients (H) with comparable left ventricular mass and normotensive healthy subjects as controls (C). The groups (n=15 each) were age- (53 +/- 9 years) and gender-matched. Quantitative analysis of echocardiographic digitalized imaging was performed to calculate the mean grey level (MGL) and cyclic variation index (CVI). RESULTS: The haemodialysis patients had a significantly lower CVI compared with hypertensives and controls both for septum (D): -2.5 +/- 17.4% vs (H); 11.8 +/- 17% vs (C); 43.2 +/- 15.4% (P<0.001) and for posterior wall (D): -10.1 +/- 261% vs (H); 14.2 +/- 14.7% vs (C); 46.6 +/- 17.2% (P<0.001). A significant inverse relationship was found between intact parathyroid hormone (iPTH) and CVI. CONCLUSION: Abnormalities of two-dimensional echocardiographic grey level distribution are present in both haemodialysis patients and hypertensive patients, but seem unrelated to the degree of echocardiographic hypertrophy. These videodensitometric myocardial alterations are significantly higher in dialysis patients than in hypertensive patients with the same extent of left ventricular hypertrophy. The iPTH level may play a role in the development of the ultrasonic myocardial alterations, which probably represent an early stage of uraemic cardiomyopathy.

Case-Control Studies↗

PubMed1999

Effects of anabolic-androgenic steroids on weight-lifters' myocardium: an ultrasonic videodensitometric study.

BACKGROUND: Recent bioptical data have shown that in weight-lifters (WL) under the pharmacological effects of anabolic-androgenic steroids (AAS), a focal increase in myocardial collagen content might occur as a reparative mechanism against a myocardial damage. OBJECTIVE: The aim of this study was to investigate whether by using videodensitometry an early identification of the changes in myocardial texture is possible or a potential sign of myocardial damage, which can potentially occur in WL who have used AAS. METHODS: Ten males WL (mean age: 32+/-6 yr) who had regularly used AAS (users), were compared with 10 male WL at same training level (nonusers), who had not used any drugs and with 10 healthy sedentary controls (controls). The three groups were age and sex-matched. Echocardiographic parietal, septal thickness, and left ventricular mass (LVMbs) were evaluated. Left ventricular systolic and diastolic functions were evaluated with Doppler examination. Quantitative analysis of echocardiographic digitized data was carried out with a calibrated 256 gray level digitization system, in order to calculate the mid-septum and the mid-posterior mean gray level (MGL) and to derive the cyclic variation index (CVI), i.e., the percent MGL variation during cardiac cycle. RESULTS: The weight and relative body mass index were significantly higher in WL (P<0.001); also the diastolic blood pressure was slightly but significantly higher in users in comparison both with nonusers and controls (P<0.01). Systolic and diastolic functional parameters overlapped in the three groups. LVMbs was significantly higher in users (145+/-17) and in nonusers (122+/-27) vs. C (104+/-18 g x m(-2)) (p<0.001). CVI at septum level showed significant differences: users: (2.3+/-31%) vs nonusers: (23+/-8) and controls (29+/-5) (P<0.005); although no significant difference was found between nonusers and controls. CVI at posterior wall level followed a similar pattern. No relationship was found between CVI and LVMbs or wall thickness. DISCUSSION: As brought out by videodensitometry, despite an increase in septal and parietal thickness and consequently in LVMbs, the physiological pressure overload that happens in WL during sport activities, in absence of any drugs, does not modify the myocardial ultrasonic texture. The abuse of AAS in WL, on the other hand, determines some alterations of the myocardial textural parameters. The real significance of these changes of myocardial texture detected with videodensitometry in WL who use anabolic-androgenic steroids, present also in the absence of other systolic and diastolic left ventricular functional indexes alterations, needs to be further explored with a larger population through the comparison with endobioptical data and with a follow-up study approach.

Adult↗

PubMed1999

Effects of tramadol on experimental inflammation.

We examined the ability of the analgesic drug tramadol to affect the development of inflammation in rats. The acute administration of tramadol significantly reduced the edema and the hyperalgesia induced by yeast injection in the paw. Moreover, in the subcutaneous carrageenin-induced inflammation, tramadol reduced the amount of the exudate, as well as the prostaglandin (PG)E2-like bio- and immuno-activity in the exudate; on the contrary, leukotriene (LT)B4 concentrations in the exudate were not changed. However, tramadol did not affect the ability of macrophages to migrate towards the chemotactic peptide N-formyl-L-methionil-L-leucyl-L-phenylalanine (FMLP). Our results suggest that tramadol is able to inhibit the development of different types of inflammation in the rat without affecting immune mechanisms, and contribute to explain the efficacy of this drug in the treatment of inflammatory pain.

Analgesics, Opioid↗

PubMed1999

Spontaneous and gamma-aminobutyric acid (GABA)-activated GABA(A) receptor channels formed by epsilon subunit-containing isoforms.

A new gamma-aminobutyric acid (GABA)A receptor (GABAR) subunit class, epsilon, has recently been cloned and shown to form functional channels when coexpressed with both alpha and beta subunits. We report that the combination of alpha1beta3epsilon subunit subtypes expressed in L929 cells produced functional chloride ion channels that were both spontaneously active and gated by the application of extracellular GABA. When cells were voltage-clamped at -75 mV in the whole-cell configuration, holding currents of 50 to 300 pA associated with increased noise were consistently recorded. The application of pentobarbital and loreclezole, which increase GABAR currents, increased the holding current, whereas the application of zinc and picrotoxin, which reduce GABAR currents, reduced the holding current in a concentration-dependent manner. Coexpression of alpha1beta3gamma2L, alpha1beta3delta, alpha1epsilon, beta3epsilon, alpha1beta3, or epsilon subtypes did not produce holding currents that were sensitive to picrotoxin (30 microM). Cells expressing alpha1 beta3epsilon subtypes had concentration-dependent GABAR currents that were potentiated by pentobarbital, loreclezole, and lanthanum and inhibited by zinc and furosemide. Spontaneous and GABAR single-channel currents from alpha1beta3epsilon receptors had single-channel conductances of approximately 24 pS. The biophysical properties and the effects of allosteric modulators were similar for spontaneous and evoked GABAR currents, suggesting that a single GABAR isoform was responsible for both currents. These data extend the pharmacological characterization of epsilon-containing GABARs and demonstrate that incorporation of the epsilon subunit permits spontaneous channel gating while preserving the structural information necessary for GABA sensitivity.

Animals↗

PubMed1999

Ultrasonic myocardial texture versus Doppler analysis in hypertensive heart: a preliminary study.

-Doppler-derived parameters of transmitral flow are useful indices of diastolic dysfunction in the hypertensive heart. Different degrees of myocardial involvement in hypertensive heart can be detected by videodensitometric myocardial textural analysis. The aim of this study was to compare Doppler-derived and ultrasonic videodensitometric parameters in the differentiation of healthy hearts from hypertensive hearts. We compared a group of age-matched (59+/-9 years) male essential hypertensive patients (n=53) with normotensive healthy subjects as controls (n=32). All subjects provided ambulatory blood pressure measurements for the evaluation of 24-hour mean systolic and diastolic blood pressure. A transmitral flow Doppler analysis was performed on all subjects. A quantitative analysis of the echocardiographic digitized imaging was performed with the help of a calibrated digitization system to calculate the septum and the posterior wall textural parameters. The myocardial mean gray level (MGL) was calculated to derive the cyclic variation index (CVI): (MGLend-diastolic-MGLend-systolic)/MGLend-diastolic x100. When compared with controls, the hypertensive patients showed a significantly lower CVI for both septum (-11.1+/-26.8% versus 34. 7+/-16.3%; P<0.001) and posterior wall (-11.2+/-27.6% versus 38. 2+/-15.4%; P<0.001). Individual analyses for the ratio of peak transmitral flow velocity in early diastole to the peak transmitral flow velocity in late diastole showed that only 24% of the patients (13/53) were discriminated from normal subjects by this parameter. Individual analyses for CVI, however, at both septum and posterior wall levels, showed that 74% of the patients (39/53) were discriminated from normal subjects by this second parameter. In comparison with Doppler-derived indices of diastolic filling, the videodensitometric parameters showed a significantly higher ability to discriminate between hypertensive subjects and normal controls.

Aged↗

PubMed1999

Ambulatory blood pressure: normality and comparison with other measurements. Hypertension Working Group.

Previous studies have reported results on 24-hour ambulatory blood pressure (ABP) in Europe and Japan, but no data exists from South America. In this study, we conducted a population survey to identify reference values and to compare ambulatory blood pressure with clinic, home, and self-measured values. A random sample of 2650 adults was selected among 190 000 people covered by our prepaid healthcare institution. Clinic (physician and nurse) and home (nurse) blood pressure measurements were performed 3 times each, with semiautomatic electronic equipment. Self-measurements were performed by the subjects manually activating the ambulatory device. We analyzed 1573 individuals who were not receiving antihypertensive therapy from 1921 participants. Self-measurement was available in a subgroup of 577 participants younger than the whole sample. Normal ambulatory blood pressure limits were estimated as those that best correlated with 140/90 mm Hg at clinic. Estimated values were 125/80 mm Hg for 24-hour ambulatory (range: 122 to 128 and 77 to 83 mm Hg) and 129/84 mm Hg for daytime ambulatory (range: 127 to 132 and 81 to 86) blood pressure, depending on gender and age. Ambulatory and clinic blood pressures increased with age. The age-dependent increase in ABP was similar in women and men. Average blood pressure at clinic was 124/79 mm Hg by physician and 123/78 mm Hg by nurse. Nurse measurement at home was 125/78 mm Hg, daytime ambulatory was 121/77 mm Hg, and 24-hour ambulatory was 118/74 mm Hg. The values of the subgroup with self-measurement were physician 119/77 mm Hg; nurse at clinic 118/77 mm Hg; nurse at home 121/78 mm Hg; self-measured 115/72 mm Hg; daytime ambulatory 119/77 mm Hg; and 24-hour ambulatory 115/73 mm Hg. This study shows that a 24-hour ABP average value of 125/80 mm Hg and a daytime ABP average value of 129/84 mm Hg are suitable upper limits for normality. Higher limits would yield an artificially higher prevalence of white coat hypertension. Most subjects showed higher blood pressure levels when measurements were performed by healthcare personnel at a clinic or at home than when self-measured at home.

Adult↗

PubMed1999

Evaluation of severe insomnia in the general population: results of a European multinational survey.

The epidemiology of severe insomnia and its effect on quality of life and healthcare consumption was assessed in a survey of the general population of five northern European countries. Applying established consumer sampling techniques, insomnia sufferers were selected from the general population using a questionnaire, conducted by face-to-face interview, and severity of insomnia was ranked (severe, mild/moderate, no sleep complaint) using a specific algorithm. Population samples were matched according to case control methodology for age, gender and geographical region. A second questionnaire gathered information on sleep problems, quality of life (SF-36 scores) and healthcare consumption. The prevalence of severe insomnia ranged from 4% to 22%, was higher in females than in males, but did not increase significantly with age. Patients with severe insomnia had been experiencing sleeping problems for a median of 2-6 years. In all countries, insomnia had a negative impact on quality of life, and the degree of impairment in quality of life was directly related to the severity of insomnia. Individuals with severe insomnia also showed a higher level of healthcare consumption. Despite this, severe insomnia did not appear to feature prominently in the doctor-patient relationship.

Adult↗

PubMed1999

Ultrasonic videodensitometric analysis in scleroderma heart disease.

OBJECTIVES: Symptomatic cardiac involvement is a frequent visceral complication of systemic sclerosis that can affect the overall prognosis of the disease. The aim of the present study was to detect preclinical myocardial alterations in patients with systemic sclerosis using ultrasonic videodensitometric analysis. METHODS: Fifty patients with systemic sclerosis [five men, aged 48.8 +/- 11 years (mean +/- SD), range 22-65 years] with normal left ventricular function and 25 age- and sex-matched healthy controls were investigated. Exclusion criteria were the presence of positive maximal exercise stress, arterial hypertension, renal involvement and diabetes. Echocardiographic images were digitized using a real-time video-digitizer Quantitative texture analysis was performed on data from the septum and posterior wall, and mean gray level (MGL) histograms at both end-diastole (d) and end-systole (s) were obtained. The cyclic variation index (CVI) was calculated according to the formula [(MGLd - MGLs)/MGLd] x 100. Left ventricular mass, body surface corrected, was calculated according to the Penn convention. RESULTS: The pattern of variations of mean gray level during the cardiac cycle was totally different from that of the controls; this finding, probably related to myocardial fibrosis, was detected in the large majority of patients with systemic sclerosis (90%). In particular, CVI, which is the expression of the intrinsic myocardial structural function, was significantly lower than in controls (septum -31 +/- 38% versus 36 +/- 9%, P < 0.0001; and posterior wall -19 +/- 33% versus 51 +/- 20%, P < 0.0001). CONCLUSIONS: Ultrasonic videodensitometric analysis is a non-invasive, feasible method of detecting myocardial alterations in patients with systemic sclerosis, which could be related to both fibrosis and microcirculatory abnormalities. The potential role of these abnormalities in the pathogenesis of ventricular dysfunction should be investigated further.

Adult↗

PubMed1999

[Sclerosing peritonitis. A complication of LeVeen peritoneovenous shunt].

Sclerosing peritonitis (abdominal cocoon syndrome) is a rare chronic affection of the peritoneum; its etiology is multifactorial and it affects all ages. Capsulating membranes seem to grow from a poorly cellular connective deposition in many layers on the intestinal peritoneum and are casually detected by surgery or autopsy. The placement of the peritoneovenous shunt can favour the deposition of fibrin on the visceral peritoneum, determining the formation of sclerosing membranes. When mechanical occlusion occurs, surgery is the choice therapy in order to remove the obstacle and, if possible, the membranes as well.

Humans↗

PubMed1999

Tubulin isoforms are differently expressed in developing and mature neurons: a study on the cerebral cortex of newborn and adult rats.

Tubulin heterogeneity was observed in the rat brain, where these proteins can vary in different neurons suggesting multiple functions. In this paper, the different expression of tubulins in cerebral cortex between newborn and adult rats was analyzed by Western blot and immunocytochemical methods, using anti-tubulin antibodies. Our results showed that tubulins were present at higher levels in the newborn than in the adult cerebral cortex. In newborn rats, a marked staining of the perikarya and basal dendrites of pyramidal cells was noted. This significant expression of tubulins in the newborn cerebral cortex could be related to the major needs of tubulins in developing neurons. The higher amount in tyrosine-tubulin and class III beta-tubulin could be consistent with the state of "dynamic instability", typical of the microtubular network of neurons during brain development.

Aging↗

PubMed1998

Fetuin (alpha2-HS-glycoprotein) opsonizes cationic macrophagedeactivating molecules.

Macrophages become activated by bacterial endotoxin (lipopolysaccharide) and other stimuli to release proinflammatory cytokines and NO. To prevent release of toxic or potentially lethal quantities of these factors, the state of macrophage activation is counter-regulated by anti-inflammatory mediators (e.g., glucocorticoid hormones, interleukin 10, and transforming growth factor type beta). Fetuin, a negative acute-phase protein, recently was implicated as an anti-inflammatory mediator, because it is required for macrophage deactivation by spermine. In the present studies, we found that fetuin is necessary for macrophages to respond to CNI-1493, a tetravalent guanylhydrazone inhibitor of p38 mitogen-activated protein kinase phosphorylation. Fetuin dose-dependently increases macrophage uptake of CNI-1493, which can be specifically inhibited by anti-human fetuin antibodies. Anti-human fetuin antibodies render primary human peripheral blood mononuclear cells insensitive to deactivation by CNI-1493. Thus, macrophages use fetuin as an opsonin for cationic-deactivating molecules, both endogenous (e.g., spermine) and pharmacologic (e.g., CNI-1493). This role of fetuin as an opsonic participant in macrophage-deactivating mechanisms has implications for understanding and manipulating the innate immune response.

Amino Acid Sequence↗

PubMed1998

Interleukin-1 and nociception in the rat.

It has recently become accepted that several cytokines may affect peripheral and central nervous system functions. Consistently with these findings, accumulating evidence points toward an important role for interleukin- in the modulation of nociceptive information. Here we review the observations collected after the administration of this cytokine by intracerebroventricular, intrathecal or peripheral route in rats. Taken together, these data suggest that IL-1 can differently affect pain responsivity depending on the dose and the site of action, and clearly demonstrate that this immune factor is deeply involved in the modulation of neuronal functions.

Animals↗

PubMed1998

Anti-hyperalgesic effects of tramadol in the rat.

A new simple behavioral method was used for the evaluation of the anti-hyperalgesic properties of tramadol in the rat. At the lowest dose (1.25 mg/kg i.p.), tramadol did not modify thermal nociceptive thresholds, but it was able to prevent and block thermal hindpaw hyperalgesia induced by the tail injection of formalin. Our results provide evidence that tramadol blocks hyperalgesic behaviors without altering nociception, suggesting that this analgesic drug might represent a valid agent against central sensitization.

Analgesics, Opioid↗

PubMed1998

The tetravalent guanylhydrazone CNI-1493 blocks the toxic effects of interleukin-2 without diminishing antitumor efficacy.

The use of interleukin 2 (IL-2) as an antineoplastic agent has been limited by the serious toxicities that accompany the doses necessary for a tumor response. Elevation of nitric oxide (NO) and tumor necrosis factor (TNF) both have been implicated in IL-2 toxicities. CNI-1493, a tetravalent guanylhydrazone, is an inhibitor of macrophage activation including the synthesis of TNF and other cytokines. Doses of CNI-1493 as low as 1 mg/kg/day conferred complete protection against fatal toxicity of IL-2 with IL-2 doses tenfold higher than the safely tolerated level in Sprague-Dawley rats. Moreover, typical pathologic changes in the lungs, kidneys, and the liver caused by IL-2 infusion were blocked by cotreatment with CNI-1493. When animals bearing established hepatomas were given IL-2 and CNI-1493 combination therapy, 10 of 10 hepatomas regressed from 1 cm3 to <1 mm3. Intracytoplasmic TNF levels were increased in normal tissues from IL-2 treated animals, and treatment with CNI-1493 maintained TNF at control levels. The degree of apoptosis measured by terminal deoxynucleotidyltransferase-mediated dUTP-biotin nick end labeling staining of tumors following IL-2 therapy was not reduced compared with IL-2 cotreated with CNI-1493. In contrast, apoptosis in the liver and lung parenchyma following IL-2 therapy was blocked completely by cotreatment with CNI-1493. Taken together, these data showed that low and infrequent doses of CNI-1493 markedly protected animals from IL-2 systemic toxicities whereas not affecting tumor response to IL-2 therapy. With the protection afforded by CNI-1493 treatment, IL-2 therapy dose levels could be increased to provide significant antitumor effects in animals with established hepatomas.

Animals↗

PubMed1998

Expression, purification, and characterization of a recombinant erythroid-specific hexokinase isozyme.

Hexokinase type I (HK I; ATP: D-hexose 6-phosphotransferase, EC 2.7.1.1), the predominant glucose-phosphorylating enzyme in red blood cells, exists in human erythrocytes in multiple molecular forms that differ in isoelectric point and are separable by ion-exchange chromatography. The major forms, designated HK Ia, Ib and Ic, have similar kinetic properties but are characterized by different age-dependent decay and different intracellular distribution in reticulocytes. HK Ib, which elutes between HK I and HK II in the DEAE ion-exchange chromatography, appears to be unique to RBCs and different from any other hexokinase isozyme previously described. Indeed, Murakami and Piomelli recently reported the presence of a specific HK isozyme (named HKr) expressed in K562 cells and in human reticulocytes and, moreover, the resolution of the human HK I gene structure provided the direct evidence of an erythroid-specific exon 1. To further investigate the microheterogeneity of HK I in human RBCs we established a prokaryotic expression system for the HKr isozyme, using the pET plasmid, inducible with IPTG. The recombinant HKr, expressed in bacterial cells as a catalytically active enzyme, was purified to homogeneity by a combination of DEAE ionexchange chromatography followed by hydrophobic interaction chromatography and dye-ligand affinity chromatography. The kinetic and chromatographic properties of the homogeneous recombinant HKr suggest that this erythroid-specific HK isozyme in fact corresponds to the HK isoform previously described in human RBCs and referred to as HK Ib.

Erythrocytes↗

PubMed1998

Two-year treatment with oral contraceptives in hyperprolactinemic patients.

The aim of this prospective study was the follow-up for 2 years in symptoms, serum prolactin (PRL) levels, and radiological aspects of a group of young patients using oral contraceptives (OC) with hyperprolactinemia. A total of 16 hyperprolactinemic women (eight with idiopathic hyperprolactinemia and eight with pituitary microadenoma) who started OC use were admitted in the study. After 2 years of OC use, the assessable patients showed a nonsignificant decrease in plasma PRL level (26.8 +/- 29.4 micrograms/mL, range 4.2-97.1 micrograms/mL vs 56.3 +/- 31.5 micrograms/mL, range 23.5-144 micrograms/mL). No patient experienced any radiological changes during OC treatment. In conclusion, although the number of observations is limited, the data suggest that after 2 years of follow-up, no harmful effect of OC use was observed in these patients.

Adult↗

PubMed1998

Polychlorinated biphenyls (PCBs) and organochlorine pesticides (OCPs) in the sediments of an Italian drinking water reservoir.

The concentration of 9 polychlorinated biphenyls (PCB 28, 52, 101, 151, 153, 170, 180, 183 and 194) and of 6 micropollutants commonly classified as organochlorine pesticides, or OCPs (alpha-HCH, beta-HCH, gamma-HCH, p,p'-DDT, p,p'-DDE and p,p'-DDD), was determined in 22 sediment samples of lake Simbirizzi, an artificial reservoir supplying drinking water to the city of Cagliari (Sardinia, Italy). The quantification was performed by analysing purified sediment extract with HRGC-ECD. The average concentrations proved to be relatively low. In the case of p,p'-DDE, the contaminant with the highest concentration, a mean value of 0.84 ppb (micrograms/kg d.m.) was found. These relatively low concentrations and the comparison with data relating to other lakes suggest that, as far as PCBs and the majority of OCPs are considered, atmospheric inputs are likely to be the main source of contamination. Only for lindane (gamma-HCH) it is possible to assume a contribution from agricultural activities. The presence of its isomers (alpha-HCH and beta-HCH) was attributed to natural occurring reactions of the gamma-form.

Agriculture↗

PubMed1998

Expression of hexokinase mRNA in human hippocampus.

The expression of hexokinase messenger RNA was evaluated in human hippocampus using in situ hybridization technique. The message showed an uneven distribution with high levels present in the granular cell layer of the dentate gyrus and CA3 region. The detection of specific transcripts was also observed in the lateral geniculate nucleus, the dentate polymorphic cell layer and the parahippocampal gyrus. The data suggest that, in the hippocampus, the expression of hexokinase is higher in neurons than in glial cells and that the rate of glucose metabolism may display considerable variations in the different subregions of this area.

Adult↗