Biomedical subjects

A Bassi

Publications and source records attributed to A Bassi.

At least 73 records · Page 4Linked to original sources

PubMed1995

Directional coronary atherectomy and progressive coronary dilatation: a comparative analysis of acute outcome.

To evaluate the acute results and in-hospital complications of directional atherectomy (DCA) as compared to progressive coronary dilatation (PCD), we retrospectively analyzed the acute outcome of DCA with PCD in age-, sex-, vessel-, and lesion morphology-matched groups of patients during the same time span. There was a total of 73 matched patients (77 lesions) in each group. Angiographic success on the basis of intent to treat was 85% in the DCA cohort versus 97%. The preprocedural mean diameter stenosis was similar between the two groups (87% vs 84%; p = n.s.). The mean postprocedural stenosis was significantly lower with DCA than with PCD (11.2% vs 19.7%; p < or = 0.05). Complications including death, myocardial infarction, and need for emergency bypass surgery were not statistically different in either group. In conclusion, PCD offers an alternative method of coronary intervention in patients with "atherectomy anatomy" with a significantly higher success rate. It can also be used successfully when DCA fails or cannot be performed because of technical factors.

Age Factors↗

PubMed1995

Systemic passive transfer studies using IgM monoclonal antibodies to sulfatide.

We present a patient with benign IgM-gamma anti-Sulfatide (SUL) whose neuropathy was transferred in newborn rabbits. The patient's clinico-pathological picture of anti-SUL-associated demyelinating neuropathy is reported. The monoclonal IgM antibodies prepared by Tatum's method, that retained their biological activity, were passively transferred to newborn rabbits. The passive transfer produced demyelinating nerve lesions very similar to the donor antibody neuropathy. In experimental lesions we observed the human IgM anti-SUL antibodies binding to Schmidt-Lanterman incisures and nodes of Ranvier. We postulate that the myelin-specific and complement-dependent lesions observed in the peripheral nerve support the potential demyelinating role of anti-SUL antibodies. Moreover, the pattern of the antibody binding to the perineuronal sheath of satellite cells in dorsal root ganglia strengthen the hypothesis that anti-SUL antibodies may have a pathogenetic role in this sensorimotor syndrome.

Aged↗

PubMed1995

Physico-chemical properties of membranes of recovered erythrocytes in blood autologous transfusion: a study using fluorescence technique.

Using fluorescence polarization of 1,6-diphenyl-1,3,5-hexatriene (DPH) and its derivative trimethylammonium-1,6-diphenyl-1,3,5-hexatriene (TMA-DPH), we have investigated the fluidity in erythrocyte membranes isolated from intraoperatively and postoperatively recovered erythrocytes, compared to membranes isolated from untreated erythrocytes or stored red blood cells (RBCs). Fluorescence polarization (Pf) of DPH and TMA-DPH was not significantly modified in membranes isolated from intraoperatively and postoperatively recovered RBCs compared to membranes isolated from untreated fresh RBCs or stored RBCs. However, using 2-dimethyl-amino-6-lauroyl-naphtalene (Laurdan), a very sensitive molecule, a significant increase in polarity in membranes from stored RBCs compared to untreated, intraoperatively and postoperatively recovered RBCs was observed. Moreover, there was significantly higher susceptibility to oxidative stress in membranes isolated from stored RBCs, compared to untreated and intraoperatively or postoperatively recovered RBC membranes, both at baseline and after oxidative stress. Our results suggest that intraoperative and postoperative recovered RBCs are less damaged than stored RBCs.

Aged↗

PubMed1995

The lipoprotein composition of plasma and ascitic fluid in liver cirrhosis.

Lipoprotein particles were examined in plasma and ascitic fluid from nine patients (5 males and 4 females) with liver cirrhosis and in plasma from nine control subjects. LDL and HDL fractions were isolated by ultracentrifugation under rate flotation conditions in a zonal rotor. LDL size was analysed by non-denaturing polyacrylamide gradient gel electrophoresis. Plasma lipids in cirrhotic patients were markedly reduced compared to controls. Free cholesterol represented 45.3% of the total cholesterol in plasma and 70.4% of the total cholesterol in the ascitic fluid. The total cholesterol-triglyceride ratio was three times higher in the plasma than in the ascitic fluid of cirrhotic patients. The LDL particles had the same flotation properties in plasma from cirrhotic patients as in that from controls. In cirrhotic patients the IDL concentration was higher than that in controls. In ascitic fluid the LDL particles had a higher flotation rate than in the plasma. The LDL diameter as measured by gradient gel electrophoresis was similar in both plasma and ascitic fluid of the cirrhotic patients as well as in the plasma of controls. In plasma and ascitic fluid of cirrhotic patients only a single HDL subclass (HDL1) could be identified. HDL1 particles had a higher flotation rate than normal HDL particles. The plasma levels of all the apoproteins were reduced in cirrhotic subjects compared to controls, but to a variable degree; while apo CII level in cirrhosis represented only 9% of the control level, the apo E level represented 77% of the control level.(ABSTRACT TRUNCATED AT 250 WORDS)

Ascites↗

PubMed1995

Blood saving program: a multicenter Italian experience.

To assess the causes of failure in a blood saving program and the consequent need for homologous transfusions during major orthopedic surgery, data were collected from six orthopedic centers where an autotransfusion program was carried out from 1992-1994. The 1,576 (1,016 female and 560 male) patients studied (average age 63.6 +/- 10 years) were treated either for total hip prosthesis (1,144 pts) total knee prosthesis (212 pts), plate and screw removal plus hip prosthesis (8 pts), hip revision (cup 48 pts, stem 10 pts, cup plus stem 146 pts) and total knee revision (8 pts). Ninety percent of patients did not undergo homologous transfusions, which was significantly connected to: male sex (8% versus 11.7% p = 0.02), younger age (63.2 vs 66.9 years, p = 0.0001), higher weight (male 76 vs 70.7 Kg. p = 0.003, female 65.6 vs 61.9 Kg. p = 0.0003); higher baseline Hb (13.9 vs 12.8 g/dl, p = 0.0041), shorter operation time (110 vs 128 minutes, p = 0.0001); use of indobufen for antithromboembolic prophylaxis (indobufen 4.6% vs heparin calcium 15.2% vs low molecular weight heparin 9% p = 0.0001). On the contrary, the factors favoring homologous transfusions were: peripheral anesthesia (spinal and epidural 15.3% vs general 9.3% vs integrated 9.8% p = 0.016), total hip or knee revision, fixation device removal before hip prosthesis, systemic hypertension and coronary heart disease.

Aged↗

PubMed1995

Anaesthesia and autologous transfusion.

The anaesthesiologist plays a central role in co-ordinating the combined application of the various blood saving techniques. In fact, to carry out transfusion therapy correctly, the anaesthesiologist must plan the right number of units of predeposit blood during the first examination, estimate the salvage of intra and post operative blood loss and spread the infusion of the units over the first three days in order to keep the patient in a state of haemodilution. From January 1992 to June 1994 in the department of anaesthesia and the intensive care unit, 980 patients were treated for total joint replacement: 714 total hips (7 after removal of plates and screws) 145 revisions, and 121 total knee prostheses. Basal Hb was 13.4 +/- 1.4 g/dl (range 6.7-17.9 g/dl). Homologous transfusions were carried out in 6.3% of these patients. The need to use homologous transfusions was negatively influenced by female sex, coronary heart disease (p = 0.005), length of surgery and type of antithromboembolic prophylaxis (indobufen has a significantly low incidence-p = 0.0001--compared to calcium heparin or low molecular weight heparin).

Adult↗

PubMed1995

[Evaluation of the efficacy of oral sumatriptan in the management of migraine attacks. Clinical results].

This italian multicentre, double blind, parallel groups study compared the efficacy, safety and tolerability of oral sumatriptan, given as new film-coated tablet, with placebo in the acute treatment of migraine. 88 Patients received placebo and 162 patients received sumatriptan 100 mg (plus an optional dose 2 h later if the headache persisted plus a further optional dose for recurrence within 24 h). Sumatriptan was significantly more effective than placebo at releiving headache at 2 h (51% versus 31%, P = 0.003) and 4 h (71% versus 35%, P < 0.001). Fewer sumatriptan-treated patients required a second dose compared with placebo-treated patients (49% versus 74%, P < 0.001). Sumatriptan was more effective than placebo at relieving nausea, vomiting and photophobia/phonophobia. Few patients were evaluable for treatment of headache recurrence, and statistical analysis was not possible. More sumatriptan-treated patients than placebo-treated patients reported adverse events (29% versus 16%) but the difference was not statistically significant. More of these events were mild to moderate in severity, of short duration and resolved without treatment. Sumatriptan had no clinically significant effect on blood pressure, heart rate, electrocardiogram or laboratory test results. It is concluded that oral sumatriptan 100 mg, given as a film-coated, tablet, provides an effective and well-tolerated acute treatment for migraine.

Acute Disease↗

PubMed1995

N30 wave amplitude of somatosensory evoked potentials from median nerve in Parkinson's disease: a pharmacological study.

We studied N20 and N30 waves of Somatosensory Evoked Potentials from median nerve stimulation in different pharmacological conditions. N30 wave amplitude was decreased in 33 parkinsonians without therapy in comparison with a group of age-matched normal subjects. In a group of 19 parkinsonians, N30 wave amplitude was significantly augmented during apomorphine infusion and less evidently, but still significantly, during chronic 1-dopa therapy. The administration of an oral dose of haloperidol in 11 normals did not affect significantly the studied parameters. The infusion of apomorphine in 6 psychotic patients with extrapyramidal symptoms secondary to long-term treatment with neuroleptics, determined, together with a clear-cut clinical amelioration, a significant increase of N30 amplitude and N30/N20 ratio. Possible pathophysiological hypothesis of such electrophysiological modifications are discussed.

Aged↗

PubMed1994

Relationship between time of activation of phospholipase C-linked plasma membrane receptors and reloading of intracellular Ca2+ stores in LAN-1 human neuroblastoma cells.

The effect of sequential stimulation of different inositol (1,4,5)-trisphosphate (IP3)-linked receptors on the functioning of intracellular Ca2+ stores was evaluated in single LAN-1 human neuroblastoma cells by means of fura-2 microfluorimetry. Homologous restimulation both in the absence and in the presence of extracellular Ca2+ with endothelin-1 (ET-1), Lys-bradykinin (BK), and ATP did not elicit an intracellular Ca2+ increase, whereas a [Ca2+]i elevation after carbachol (CCh) re-exposure was obtained only in the presence of extracellular Ca2+. Since thapsigargin and ionomycin, in the absence of extracellular Ca2+, were still able to release Ca2+ after ET-1, BK, and ATP but not after CCh, it can be argued that in the first case the stores were not completely depleted. This evidence was also confirmed by the fact that LAN-1 cells, sequentially exposed in different order to ET-1, BK, ATP, and upon extracellular Ca2+ removal, showed an increase of [Ca2+]i although progressively reduced in magnitude. By contrast, when CCh was perfused as the first agonist, it completely precluded any further Ca2+ mobilization by the other three agonists. In addition, the lack of potentiation of the Ca2+ response when BK and ET-1 were superfused together and the potentiation of Ca2+ response elicited by ET-1 after BK, when the plasma membrane Ca2+ efflux pathways were blocked by lanthanum during the first agonist exposure, indicated that LAN-1 cells can recycle cytoplasmic Ca2+ when exposed to ET-1, BK, ATP but not when exposed to CCh. This inhibitory effect of CCh (perfused for 90 s) on Ca2+ refilling was strictly dependent on the time of receptor occupancy since the exposure to CCh for a shorter period (15 s) produced the same effect on Ca2+ refilling when ET-1, BK, and ATP were perfused, as first agonist, for 90 s. Furthermore, the entity of Ca2+ refilling after 15 s of BK receptor occupancy was similar to that observed after 90 s. This seems to suggest that the receptors for ET-1, BK, and ATP maintain the transductional mechanisms in an activated state for a time shorter than the time of receptor occupancy. This was confirmed by the fact that IP3 levels during a 90-s BK exposure fell to prestimulated value within 30 s, whereas after CCh they reached a sustained plateau phase, after the peak.

Calcium↗

PubMed1994

Decreased activity of scavenger enzymes in human hepatocellular carcinoma, but not in liver metastases.

To investigate the role of oxygen free radicals in hepatocellular carcinoma we assayed tissue scavenger enzymes (superoxide dismutase and selenium-dependent glutathione peroxidase) in liver homogenate, plasma concentrations of vitamins A and E and the serum selenium level from 19 control patients, 23 cases of hepatocellular carcinoma and 18 cases of metastases to liver from different carcinomas. In hepatocellular carcinoma tissue the enzyme activities were all significantly lower than in control liver and in metastases-bearing liver; the enzyme activities of the latter tissues were not different from control liver. In contrast, normal liver adjacent to the hepatocellular carcinoma had decreased activity of superoxide dismutase. Serum selenium concentrations were significantly decreased in patients with hepatocellular carcinoma and those with liver metastases, while vitamin A was significantly decreased only in the former. These findings suggest that hepatocellular carcinoma develops in liver with severe impairment of cellular antioxidant systems, since, in patients with liver metastases from different cancers, despite low selenium concentrations, cellular scavenger enzymes have normal activities.

Adult↗

PubMed1994

Factors affecting the thiobarbituric acid test as index of red blood cell susceptibility to lipid peroxidation: a multivariate analysis.

The relationship between formation of thiobarbituric acid reactive substances (TBARS) in red blood cells (RBC) after exposure to H2O2 and factors potentially able to modulate it was investigated by a multivariate analysis in 92 healthy volunteers. The independent covariates considered were: RBC membrane fatty acids and cholesterol, RBC antioxidant enzymes and zinc, plasma vitamins A and E and serum selenium, zinc and copper. The stepwise multiple-linear-regression analysis revealed RBC membrane fatty acids and cholesterol as predictors of a consistent proportion of the RBC-TBARS variability whereas none of the antioxidants entered the equation. The unsaturation index was the most important individual predictor; RBC-TBARS increased with increasing concentrations of total omega-3 polyunsaturated fatty acids, C 20:5 omega-3 and cholesterol, whereas they decreased with increasing concentrations of total monounsaturated fatty acids, saturated fatty acids, C 16:0 and C 18:0. It is suggested that formation of TBARS, at least in currently used conditions, reflects mainly the lipid composition of the tissue under investigation, without giving sufficient information about the status of the antioxidant defences.

Adult↗

PubMed1994

Appearance of depolarization- and maitotoxin-induced [Ca2+]i elevation in single LAN-1 human neuroblastoma cells on exposure to retinoic acid.

LAN-1 is a human neuroblastoma cell line that, in the undifferentiated state, does not respond to membrane depolarization with an elevation of [Ca2+]i, monitored by fura-2 single-cell microfluorimetry. The exposure of LAN-1 cells to the differentiating agent retinoic acid induced the appearance of [Ca2+]i elevation elicited by 55 mM K+. Maitotoxin, a putative activator of voltage-sensitive Ca2+ channels, did not evoke an elevation of [Ca2+]i in undifferentiated LAN-1 cells, but produced a marked and sustained increase in [Ca2+]i when superfused in retinoic acid-treated cells. Both high K(+)- and maitotoxin-induced [Ca2+]i elevation in retinoic acid-differentiated LAN-1 cells was reversed by the lanthanide Gd3+, an inorganic Ca(2+)-entry blocker, and by the snail toxin omega-conotoxin GVIA, which interacts with the N subtype of voltage-sensitive Ca2+ channels. In contrast, both Bay K 8644 and nimodipine, dihydropyridines that selectively activate or block, respectively, the L-channel subtype, were completely ineffective. The tumor promoter phorbol 12-myristate 13-acetate (100 nM), a protein kinase C activator, inhibited the elevation of [Ca2+]i due to Ca2+ influx elicited by membrane depolarization. K(+)-induced [Ca2+]i elevation appeared 24 h after the addition of retinoic acid and reached the highest magnitude after 72 h. Furthermore, 8 days after the removal of the differentiating agent from the culture medium, the high K(+)-induced increase of [Ca2+]i was still present.(ABSTRACT TRUNCATED AT 250 WORDS)

3-Pyridinecarboxylic acid, 1,4-dihydro-2,6-dimethy↗

PubMed1994

Erythrocyte Na(+)-H+ exchanger and Na(+)-Li+ countertransport activity in primary aldosteronism.

Several authors have described increased Na-H exchanger activity in essential hypertension but no data are available in secondary forms of hypertension such as primary aldosteronism. We measured Na-H exchanger kinetics together with Na-Li countertransport Vmax in the erythrocytes of eight patients with primary aldosteronism and in 15 normotensive control subjects. Plasma aldosterone, plasma renin and plasma potassium were also evaluated. Na-H exchanger Vmax appear to be increased in patients with primary aldosteronism and Hill's n, an index of co-operativity amongst intracellular proton binding sites, was significantly lower in patients than in controls. No statistically significant differences were found between affinity for intracellular protons (K50%) and for Na-Li countertransport Vmax between the two groups studied. We were unable to find any correlations between Na-H exchanger Vmax and Na-Li countertransport Vmax in the two groups considered as a whole. From the present data Na-H exchanger overactivity would not appear to be a specific feature of essential hypertension but seems to be characteristic in patients with primary aldosteronism.

Adult↗

PubMed1993

Autotransfusion: 15 years experience at Rizzoli Orthopaedic Institute.

The program of blood saving, result of 15 years of experience, includes predeposit (1977) hemodilution (1979) intra (1984) and postoperative (1985) salvage, careful intra and postoperative bleeding control, use of homologous transfusion only in case of intolerated anaemia even for 7-8g/dl Hb values. The use of autologous compared to homologous transfusion passed from 19% in 1984 to 62% in 1992. In 1992 in the surgical division of the 1st Anaesthesia and Intensive Care unit, 414 patients underwent prosthetic hip and knee surgery, 8% of these patients were homologously transfused.

Adult↗

PubMed1993

Plasma predeposit: the role of productive plasmapheresis.

At the Rizzoli Orthopaedic Institute, as part of our autotransfusion program, we have recently had the possibility to introduce plasma predeposit by means of productive plasmapheresis in patients undergoing major orthopaedic surgery, in which bleeding more than 50-60% of circulating blood mass was expected and so a greater quantity of plasma compared to red blood cells was considered necessary. Red cells and fresh frozen plasma predeposits and perioperative blood recovery was sufficient to cover transfusional needs. In our opinion, plasma predepositing by plasmapheresis is indicated in patients with anaemia, cardiopathy and/or vasculopathy, minute constitution.

Adult↗

PubMed1992

Effects induced by olive oil-rich diet on erythrocytes membrane lipids and sodium-potassium transports in postmenopausal hypertensive women.

Since we have observed that monounsaturated fatty acids (MUFA) enriched diet modifies red cell membrane lipids and cation transport systems in normotensive subjects, we similarly evaluated a group of hypertensive patients undergoing an analogous dietary modification. In a group of 18 moderately hypertensive women, the diet was supplemented for two months with olive oil (about 45 g/day), which replaced an equal amount of seasoning fats. Before and after this period, red cell fatty acid composition was evaluated by gas-chromatography in order to verify diet compliance: a significant increase in oleic acid was observed, while the content of saturated and polyunsaturated fatty acids remained unchanged. After olive oil, maximal rates of Na-K pump (5580 +/- 329 vs 6995 +/- 390, p less than 0.001) and Na-K cotransport (Na-COT 544 +/- 52 vs 877 +/- 46, p less than 0.001: K-COT 790 +/- 76 vs 1176 +/- 66, p less than 0.001), cell Na content (9.58 +/- 0.4 vs 10.61 +/- 0.6, p less than 0.03) and passive permeability for Na (936 +/- 74 vs 1836 +/- 102, p less than 0.001) rose significantly. Although the reduction in maximal rate of the Li-Na CT after olive oil was not significant, it was the only cation transport parameter being correlated with the variations of membrane lipids, namely negatively with UFA (r = -0.528, p less than 0.05) and positively with SFA (r = 0.482, p less than 0.005). The change in maximal rate of Li-Na CT was also correlated with the variation of systolic and diastolic BP (r = 0.50, p less than 0.03).(ABSTRACT TRUNCATED AT 250 WORDS)

Blood Pressure↗

PubMed1992

LAN-1: a human neuroblastoma cell line with M1 and M3 muscarinic receptor subtypes coupled to intracellular Ca2+ elevation and lacking Ca2+ channels activated by membrane depolarization.

The LAN-1 clone, a cell line derived from a human neuroblastoma, possesses muscarinic receptors. The stimulation of these receptors with increasing concentrations of carbachol (CCh; 1-1,000 microM) caused a dose-dependent increase of the intracellular free Ca2+ concentration ([Ca2+]i). This increase was characterized by an early peak phase (10 s) and a late plateau phase. The removal of extracellular Ca2+ reduced the magnitude of the peak phase to approximately 70% but completely abolished the plateau phase. The muscarinic-activated Ca2+ channel was gadolinium (Gd3+) blockade and nimodipine and omega-conotoxin insensitive. In addition, membrane depolarization did not cause any increase in [Ca2+]i. The CCh-induced [Ca2+]i elevation was concentration-dependently inhibited by pirenzepine and 4-diphenylacetoxy-N-methylpiperidine methiodide, two rather selective antagonists of M1 and M3 muscarinic receptor subtypes, respectively, whereas methoctramine, an M2 antagonist, was ineffective. The coupling of M1 and M3 receptor activation with [Ca2+]i elevation does not seem to be mediated by a pertussis toxin-sensitive guanine nucleotide-binding protein or by the diacylglycerol-protein kinase C system. The mobilization of [Ca2+]i elicited by M1 and M3 muscarinic receptor stimulation seems to be dependent on an inositol trisphosphate-sensitive intracellular store. In addition, ryanodine did not prevent CCh-induced [Ca2+]i mobilization, and, finally, LAN-1 cells appear to lack caffeine-sensitive Ca2+ stores, because the methylxanthine was unable to elicit intracellular Ca2+ mobilization, under basal conditions, after a subthreshold concentration of CCh (0.3 microM), or after thapsigargin.

Calcium↗

PubMed1992

Red blood cell susceptibility to lipid peroxidation, membrane lipid composition, and antioxidant enzymes in continuous ambulatory peritoneal dialysis patients.

OBJECTIVE: To investigate the overall susceptibility of red blood cells (RBC) to lipid peroxidation from patients on continuous ambulatory peritoneal dialysis (CAPD). METHODS: The following parameters were measured: RBC malondialdehyde (MDA) production after oxidative stress with H2O2, RBC antioxidant enzymes glutathione peroxidase (GSH-Px) and superoxide dismutase (SOD), and RBC membrane lipid composition. The levels of plasma vitamin E and serum selenium were also assayed. PATIENTS: Eleven patients on continuous ambulatory peritoneal dialysis. Twenty-one healthy blood donors of similar age were used as normal controls. RESULTS: The MDA formation after H2O2 stimulation was normal in CAPD patients (0.79 +/- 0.1 mumol/gHb versus 0.78 +/- 0.1 in the control group). RBC from CAPD patients also showed a normal SOD activity, a more than adequate vitamin E status, and a peculiar pattern of membrane lipids, with reduced polyunsaturated fatty acids (p less than 0.001) and increased monounsaturated fatty acids (p less than 0.001). Both RBC GSH-Px activity, a selenium-dependent enzyme, and serum selenium levels were significantly lower in CAPD patients, and a significant positive correlation (r = 0.68; p less than 0.02) between the two parameters was found. CONCLUSIONS: This study found a normal sensitivity to oxidant stress in RBC from a group of CAPD patients, despite an impaired GSH-Px activity. The peculiar lipid pattern of RBC membrane, characterized by reduced PUFA and increased MUFA content, may contribute, in addition to adequate SOD activity and vitamin E status, to normal RBC lipid peroxidation.

Aged↗