Biomedical subjects

R Ricci

Publications and source records attributed to R Ricci.

At least 19 recordsLinked to original sources

PubMed1992

Growth-inhibitory effect of quercetin and presence of type-II estrogen-binding sites in human colon-cancer cell lines and primary colorectal tumors.

We studied the effect of quercetin (Q) on the proliferation of HT-29, WiDr, COLO 201, and LS-174T human colon cancer cell lines. Q, between 10 nM and 10 microM, exerted a dose-dependent, reversible inhibition of cell proliferation. Cell-cycle analysis revealed that the growth-inhibitory effect of Q was due to a blocking action in the G0/G1 phase. Using a whole-cell assay with 17 beta-[3H]-estradiol as tracer, we demonstrated that all these cell lines contain type-II estrogen-binding sites (type-II EBS). By using Q and other chemically related flavonols (3,7-4'-trimethoxyquercetin, 3,7,3',4'-tetramethoxyquercetin, kaempferol, morin, and rutin), we observed that the affinities of these compounds for type-II EBS are correlated with their growth-inhibitory potential. Furthermore, the Q sensitivity of the colon cancer cell lines was correlated with the number of type-II EBS/cell. Then Q could regulate colon cancer cell growth through a binding interaction with type-II EBS. This mechanism could also be active in vivo as we have observed that cytosolic type-II EBS are present in primary colorectal cancers and that Q is effective in inhibiting the in vitro bromodeoxyuridine incorporated by neoplastic cells in these cancers.

Adenocarcinoma↗

PubMed1992

Comparative analysis of lysosomal hydrolases and natural glycoprotein substrates in the rat major salivary glands.

1. The activities of some lysosomal hydrolases and the concentrations of their natural substrates were studied in the submandibular and sublingual glands of male and female rats using biochemical procedures. 2. In sublingual gland enzyme activities and substrate concentrations show the highest values. 3. The enzyme activities appear, in general, lower and the natural substrate concentrations higher in the females with respect to males. 4. In both glands beta-galactosidase shows the highest activity and beta-glucosidase the lowest. 5. These findings suggest that metabolic turnover of glycoproteins is slower in females than in males, probably because the oestrogens control the activity of lysosomal hydrolases.

Animals↗

PubMed1992

Strampelli's osteo-odonto-keratoprosthesis. Clinical and histological long-term features of three prostheses.

The histological features are reported of osteo-odonto-acrylic laminae removed from three patients who for differing underlying causes received Strampelli's osteo-odonto-keratoprostheses (OOK) 20, 16, and 12 years previously. It appears that preservation of the alveolar-dental ligament plays a definitive role in the maintenance of the prosthesis. If this tissue undergoes necrosis as a consequence of an inflammatory disease the implanted material is eventually lost. However when no such event occurs the OOK is well preserved and well tolerated even 20 years after implantation.

Alveolar Process↗

PubMed1992

Demonstration of the formation of hydroxyl radicals in acute myocardial infarction in man using salicylate as probe.

Dihydroxybenzoic acid (DHBA) derivatives of acetylsalicylic acid (ASA) are formed in vivo by the action of the hydroxyl radical (OH.). In order to evaluate the possible formation of OH(.) in acute myocardial infarction (AMI) in man, 9 consecutive patients with a first episode of AMI (8 males, 1 female, mean age 50.3 years), treated with rt-PA, and 8 healthy volunteers (7 males, 1 female, mean age 29.8 years) were studied. All subjects received 100 mg ASA p.o. daily; venous blood samples were taken 30 min after the first dose (time 0) and then at 3-, 6-, 12-, 24- and 48 h and 5 days. Serum was analyzed by HPLC and electrochemical detection for 2,3- and 2,5-DHBA contents. 2,3-DHBA was present in all subjects with AMI and undetectable in healthy volunteers at all time points studied. Serum levels of 2,5-DHBA did not show statistically significant differences between AMI patients and healthy volunteers. These data support the hypothesis that hydroxyl radicals are formed during AMI in man.

Aspirin↗

PubMed1992

Diastolic ventricular dysfunction in noncomplicated acute myocardial infarction: the influence of gallopamil.

The goal of this study was to assess the effect of gallopamil on left ventricular (LV) diastolic function early after acute myocardial infarction (AMI). Gallopamil was compared with placebo and atenolol in two different groups of patients. Study patients, 2 days after experiencing their first AMI, in Killip class I and stable sinus rhythm, were randomized in a crossover, double-blind sequence to receive (a) gallopamil (50 micrograms/kg over 5 min) or placebo (i.v. 10-ml bolus, with a time interval of 90 min); and (b) gallopamil (50 micrograms/kg over 5 min) or atenolol (5 mg over 5 min), with a time interval of 24 h. Group I and group II consisted of 28 patients (26 men and 2 women; mean age 55 +/- 9 years) and of 14 patients (13 men and 1 woman; mean age 56 +/- 10 years), respectively. All the patients were treated with thrombolysis within 6 h from the onset of symptoms. Doppler echocardiographic examinations were performed as follows: at baseline (B) and 15 min after administration of gallopamil bolus and placebo bolus, in group I; at baseline before gallopamil (BG) and atenolol (BA), and 15 min after each bolus in group II. The following echo-Doppler parameters were calculated, at each examination: the early and late transmitral peak velocity ratio (E/A), the early and late velocity integral ratio (Ei/Ai), the peak filling rate normalized to mitral stroke volume (nMPFR), and the LV isovolumic relaxation time (IVRT), which was normalized to an 800-ms R-R cycle length in the patients in group II. Mean blood pressure (MBP) and heart rate (HR) were also measured.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMed1992

Myocyte cellular hypertrophy and hyperplasia contribute to ventricular wall remodeling in anemia-induced cardiac hypertrophy in rats.

To determine the effects of chronic anemia on the functional and structural characteristics of the heart, 1-month-old male rats were fed a diet deficient in iron and copper, which led to a hemoglobin concentration of 4.63 g/dl, for 8 weeks. At sacrifice, under fentanyl citrate and droperidol anesthesia, systolic, diastolic, and mean arterial blood pressures were decreased, whereas differential pressure was increased. Left ventricular systolic pressure and the ventricular rate of pressure rise (mmHg/s) were reduced by 9% and 14%, respectively. Moreover, developed peak systolic ventricular pressure and maximal dP/dt diminished 14% and 12%. After perfusion fixation of the coronary vasculature and the myocardium, at a left ventricular intracavitary pressure equal to the in vivo measured end diastolic pressure, a 10% thickening of the left ventricular wall was measured in association with a 13% increase in the equatorial cavitary diameter and a 44% augmentation in ventricular mass. The 52% hypertrophy of the right ventricle was characterized by an 11% thicker wall and a 37% larger ventricular area. The 33% expansion in the aggregate myocyte volume of the left ventricle was found to be due to a 14% myocyte cellular hypertrophy and a 17% myocyte cellular hyperplasia. These cellular parameters were calculated from the estimation of the number of myocyte nuclei per unit volume of myocardium in situ and the evaluation of the distribution of nuclei per cell in enzymatically dissociated myocytes. Myocyte cellular hyperplasia provoked a 9% increase in the absolute number of cells across the left ventricular wall. In contrast, myocyte cellular hypertrophy (42%) was responsible for the increase in myocyte volume of the right ventricle. The proliferative response of left ventricular myocytes was not capable of restoring diastolic cell stress, which was enhanced by the changes in ventricular anatomy with anemia. In conclusion, chronic anemia induced an unbalanced load on the left ventricle, which evoked a hyperplastic reaction of preexisting myocytes, in an attempt to normalize diastolic wall and myocyte stress.

Anemia↗

PubMed1992

C4 serum levels in newborns of diabetic mothers: relationship with metabolic assessment during pregnancy.

Serum levels of C4 complement factor are lower in diabetic patients: it is supposed that this finding is related to genetic inheritance factors of diabetes. The purpose is to compare C4 levels in newborns of diabetic mothers with maternal metabolic control during pregnancy. The results suggest that metabolic control could influence the expression of genetic factors of diabetes; in fact C4 serum levels in newborns are significantly higher (p < 0.01) than controls, but not different from those observed in large newborns of non diabetic mothers.

Complement C4↗

PubMed1991

Detection of mRNA and hnRNA using a digoxigenin labelled cDNA probe by in situ hybridization on frozen tissue sections.

A full-length cDNA clone encoding the constant region of T cell receptor beta chain was labelled by random priming DNA with digoxigenin-dUTP. The probe was used to estimate the relative amount of the receptor beta chain mRNA by in situ hybridization on frozen sections from human thymus and lymph nodes. The hybridization was visualized in blue using an anti-digoxigenin antibody conjugated with alkaline phosphatase and a subsequent enzyme-catalysed colour reaction. The distributions of the signal in tissue sections were as expected. Moreover, labelled cells showed hybrids both in the cytoplasm and in the nucleus, and strongly and weakly stained cells were clearly distinguishable. The results indicate that this method of in situ hybridization should be useful in the detection of specific mRNA in frozen sections.

Child, Preschool↗

PubMed1991

Immunodeficiency and plasma zinc levels in children with Down's syndrome: a long-term follow-up of oral zinc supplementation.

To evaluate the possible effect of zinc treatment on immune disorders in children with Down's syndrome (DS), 38 noninstitutionalized DS children were investigated. Twenty-four patients (63.2%) had plasmatic zinc levels lower than 0.70 microgram/dl ("hypozinkemic," LZn) and 14 patients (36.8%) had levels higher than 0.75 microgram/dl ("normozinkemic," NZn). No correlation was found between the zinc deficiency and recurrence and/or intensity of infections. The absolute numbers of peripheral lymphocytes, the percentages of B lymphocytes, total T cells, and serum IgG, IgA, and IgM levels did not differ between the DS children and the controls. Eight (21%) patients had CD4+ T cell counts below the lowest value for the controls. Seventeen (44%) DS patients had increased levels of CD8+ T cells. The mean percentage of Leu 7+ cells in DS subjects (22.8 +/- 12.9%) was significantly higher than that in controls (15.8 +/- 4.8%) (P less than 0.01). Notably, Ig levels and numbers of lymphocytes in each subset did not show any significant difference in NZn and LZn trisomic subjects. On the contrary the peripheral blood mononuclear cells (PBMCs) from LZn DS children showed a significantly lower proliferative response to phytohemagglutinin (PHA) (S.I. = 23.4 +/- 22.4) than that of PBMCs from NZn DS children (S.I. = 46.1 +/- 21.5, P less than 0.01). A significant increase in DNA synthesis was obtained after oral administration of zinc sulfate (20 mg/kg/day, for 2 months). The lymphocyte response to PHA appeared to be normal in all patients up to 6 months after the end of the zinc treatment and it became low in half of the patients 22 months after therapy.

Administration, Oral↗

PubMed1991

Antiproliferative activity of quercetin on normal bone marrow and leukaemic progenitors.

We used an in vitro clonogenic assay in semi-solid medium to test the sensitivity of normal bone marrow and acute myeloid and lymphoid leukaemia progenitors to the flavonol quercetin. We have studied 14 acute myeloid (AML) and four acute lymphoid (ALL) leukaemias. All ALL and the vast majority of AML (12/14) had a high sensitivity to quercetin with more than 50% growth inhibition at 2 x 10(-6) M quercetin. One M3-AML was partially quercetin-sensitive displaying 60% surviving AML-colony forming units (CFU-AML) at a quercetin concentration of 10(-5) M. One M1-AML was resistant to the growth inhibitory effect of quercetin at a concentration of 2 x 10(-5) M. The clonogenic efficiency of both AML and ALL positively correlated with leukaemic colony-forming unit (CFU-L) sensitivity to quercetin suggesting that this parameter can be useful in predicting quercetin responsiveness of leukaemic cells. We have also studied the effect of various quercetin concentrations on colony formation by normal bone marrow cells. At a quercetin concentration of 10(-5) M, we observed (in five different experiments) a mean recovery of 53% and 65% of erythroid blast-forming units (BFU-E) and granulocyte-macrophage colony-forming units (CFU-GM), respectively. Thus, normal bone marrow appeared partially resistant to quercetin, being inhibited less than 50% by quercetin concentration higher than 2 x 10(-5). When normal bone marrow were deprived in CD34+ haematopoietic progenitors the resultant population became highly sensitive to quercetin, with a mean recovery of BFU-E and CFU-GM of 5% and 12% of controls respectively in the presence of 2 x 10(-5) M quercetin. Furthermore, CD34 progenitors, positively selected, appeared fully resistant to quercetin concentrations as high as 2 x 10(-5) M. Thus, CD34+ progenitors are a quercetin-resistant component in normal bone marrow. In conclusion, our results further provide a biological basis for the therapeutic use of quercetin, considering that this compound could inhibit leukaemic cell growth without suppressing normal haematopoiesis.

Acute Disease↗

PubMed1991

[The incidence and clinical implications of left ventricular thrombosis in 769 patients with acute myocardial infarct treated with antithrombotics and fibrinolytics].

Seven hundred sixty-nine patients (pts) admitted to the Coronary Care Unit (CCU) between January 1987 and January 1990 suffering from first acute myocardial infarction (AMI) were studied. The presence of left ventricular thrombosis (LVT) was evaluated by two-dimensional echocardiography (2D-echo). The relation of LVT to site, size and intra-CCU clinical outcome of AMI, in terms of systemic embolic events, Killip class and mortality, was also assessed. AMI was transmural in 707 pts (92%), anterior in 446 pts (58%) and inferior in 261 pts (34%), non-Q in 62 pts (8%). Two hundred sixty-one pts (34%) were treated with IV thrombolytic therapy followed by IV heparin 1000 IU/h over 12 hrs and then calcium heparin (CH) 12500 IU s.c. bid; 508 pts (66%) were given only antithrombotic therapy (CH 12500 IU s.c. bid). 2D-Echo was performed within 48 hours and on day 5-7 from the onset of AMI. In 41 pts (5.3%) LVT was observed: 39 had anterior AMI (8.7% of all anterior AMI pts), one had inferior AMI (0.4% of all inferior AMI pts), and one had non-Q AMI (1.6% of all non-Q AMI pts) [p less than 0.001 for anterior AMI vs inferior and non-Q AMI]. Pts with LVT had a greater infarct size (number of akinetic plus dyskinetic segments/total number of segments x 100) compared to pts without LVT (32.3 +/- 12.6% vs 16.4 +/- 5.7%, p less than 0.001). In pts treated with thrombolytic therapy, LVT incidence was not significantly different from that of pts treated with antithrombotic therapy (4.2% vs 5.9%) alone.(ABSTRACT TRUNCATED AT 250 WORDS)

Chi-Square Distribution↗

PubMed1991

[Pharmacological effects on left diastolic ventricular function in acute myocardial infarct: comparison of gallopamil and atenolol].

The aim of the study was to assess the effects of gallopamil and atenolol administration on left ventricular (LV) relaxation and filling in patients (pts) with acute myocardial infarction (AMI), by pulsed Doppler echocardiography (PDE). Two days after first AMI, 14 pts aged 56 +/- 10 years in Killip class I and treated with thrombolysis were randomized to gallopamil (50 mcg/Kg over 5 min) or atenolol (5 mg over 5 min) IV 10 ml bolus, with a 24 hour time interval, in a cross-over double blind sequence. Four PDE were performed in each patient: at baseline, before gallopamil and atenolol IV bolus, and a 15 min after each bolus. The following Doppler parameters were calculated: early (E) and late (A) peak filling velocities and their ratios (E/A), early (Ei), late (Ai) and total (TVi) diastolic filling time velocity integrals; the ratio between Ei and Ai (Ei/Ai), the peak filling rate normalized to mitral stroke volume (calculated as E/TVi [nPRP]), the percentage of atrial contribution to total diastolic filling (%AC), and the isovolumic relaxation time (nTRIV) normalized to an 800msec RR cycle length. Compared to baseline PDE evaluation, gallopamil administration significantly shortened nTRIV (89 +/- 13 vs 116 +/- 13 msec), improved early LV filling parameters (E: 74.5 +/- 14.0 vs 58.1 +/- 14.6 cm/sec; E/A 1.2 +/- 0.4 vs 0.9 +/- 0.3; Ei: 11.2 +/- 1.8 vs 8.9 +/- 2.0 cm; Ei/Ai: 1.8 +/- 0.6 vs 1.3 +/- 0.6; nPRP: 3.9 +/- 1.0 vs 3.5 +/- 1.0 SV/sec), and reduced %AC (35.6 +/- 8.8 vs 44.6 +/- 10.6). A and Ai were not significantly changed.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMed1990

Morphological and immunohistochemical study of Down syndrome thymus.

The incidence and severity of various histologic changes were studied in the thymuses from 35 Down syndrome (DS) patients. Variable histologic alterations up to fibrotic involution of the gland were found. In addition, immunohistochemical investigation showed a reduction or absence of interdigitating reticulum cells roughly correlated with the severity of morphologic changes. The complex architectural and cellular thymic alterations, concerning both cortical and medullary microenvironment, could be correlated with the imbalances of immunity in DS patients.

Child, Preschool↗

PubMed1990

Oral administration of loxiglumide (CCK antagonist) inhibits postprandial gallbladder contraction without affecting gastric emptying.

The effect of a single oral dose of loxiglumide, a cholecystokinin antagonist, on postprandial gallbladder contraction and on gastric emptying was evaluated in humans. Following a 12-hr fasting period, two tablets of loxiglumide (400 mg each) or placebo was administered on different days, in random order and in a double-blind fashion to 10 healthy volunteers 15 min before the ingestion of a 1050-kcal standard meal. Gallbladder and antral volumes were measured by real-time ultrasonography in basal conditions and at fixed time intervals after the meal. Oral loxiglumide administration was followed by a total inhibition of the gallbladder contraction for 60 min after the end of the meal ingestion. Thereafter, up to the end of the study period, gallbladder volume was larger than that of the placebo study (at 300 min after the meal 2.7 +/- 1.6 ml after placebo and 8.2 +/- 3.5 ml after loxiglumide; P less than 0.008). No difference between placebo and loxiglumide was found in the antral volumes at any time interval (postprandial 63.5 +/- 16.5 ml after placebo and 59.4 +/- 24 ml after loxiglumide; at 300 min after the meal 20.8 +/- 13.3 ml after placebo and 18.9 +/- 9.5 ml after loxiglumide). In conclusion, a single oral dose of loxiglumide at the dose of 800 mg can inhibit postprandial gallbladder contraction without affecting gastric emptying. It would therefore appear that in man endogenous CCK, released after a solid-liquid, caloric, nutrient-balanced meal, plays a major role in the contraction of the gallbladder but does not affect gastric emptying.

Administration, Oral↗

PubMed1990

Effects of acute administration of gallopamil on left ventricular relaxation and filling dynamics in acute myocardial infarction assessed by Doppler echocardiography.

The purpose of this study was to assess the acute effect of an intravenous bolus of the calcium antagonist gallopamil on left ventricular diastolic function using Doppler echocardiography. Fifteen patients with acute myocardial infarction in the first Killip class and sinus rhythm were randomized to an intravenous bolus of gallopamil (50 micrograms/kg over 5 minutes) or placebo in a crossover sequence. Doppler echocardiography was performed at baseline and 15 minutes after each bolus. No patients had received calcium antagonists or beta blockers before the study; all patients received nitroglycerin, which was withdrawn at least 2 hours before the baseline Doppler echocardiogram. The following Doppler parameters were calculated: the early (E) and late (A) peak filling velocities, the velocities ratio (E/A), the diastolic filling time-velocity integral (TVI), the peak filling rate normalized to the mitral stroke volume (nMPFR), the isovolumic relaxation time (IVRT), and the systolic flow velocity integral (SFVI). Expressing the parameters measured after a gallopamil bolus as the percent change of those measured after placebo, E, E/A, and nMPFR increased by 25.5 +/- 11.5%, 30.6 +/- 15.5%, and 19.0 +/- 12.2%, respectively (p less than 0.001); IVRT decreased by 13.5 +/- 7.0% (p less than 0.001); and TVI increased mildly by 6.9 +/- 9.9% (p = 0.01). SFVI and A did not change significantly. Negligible differences were observed between placebo and baseline values. Heart rate, mean blood pressure, and left ventricular and atrial diameters did not change significantly. It was concluded that gallopamil infusion improves early left ventricular filling and relaxation in patients with acute myocardial infarction. Considering the unchanged loading conditions, this indicates an improvement in left ventricular diastolic performance.

Adult↗

PubMed1990

Sialic acid and neuraminidase activity in the frog oviduct: comparative biochemical investigation in the different tracts during the reproductive cycle.

1. A biochemical study was carried out on the protein-bound and lipid-bound sialic acid, and neuraminidase activity in the different tracts of the oviduct of the frog Rana esculenta during the reproductive cycle. 2. Plasma sexual steroids were also investigated by RIA. 3. Fluctuations in neuraminidase activity are related to that of glycoprotein sialic acid and plasma estradiol. Glycolipid sialic acid does not have a close relationship either with neuraminidase or plasma estradiol. 4. Very high plasma concentration of progesterone before ovulation and, on the contrary, its drop after ovulation were observed. 5. The results are discussed and hypotheses advanced to explain fluctuations of the studied parameters during the reproductive cycle.

Animals↗

PubMed1990

Neuropeptide-immunoreactive cells in human thymus.

The outer cortex of the human thymus contains a one- to two-cell-thick layer that is immunoreactive with antisera against beta-endorphin, (Leu)- and (Met)-enkephalin, bombesin, and substance P. The epithelial nature of these immunostained cells is revealed by immunoelectron microscopic studies showing the presence of desmosomal junctions. The presence of peptide-containing cells in the outer cortex, where the most immature and recently immigrated thymocytes are found, emphasizes the role of neuropeptides in regulating the microenvironment for T cell development.

Cell Differentiation↗

PubMed1990

Ventricular cross stimulation in a dual chamber pacing system: phenomenon analysis.

Seven cases of ventricular cross stimulation from a group of 23 patients implanted with DDD devices are presented. In two patients the phenomenon was observed at the moment of DDD programming at nominal values, and in five other patients it was reproduced by increasing the atrial output voltage up to ten volts. In all 23 patients cross stimulation disappeared permanently within 24 hours after implantation. From the onset of cross stimulation to its end, atrial and ventricular threshold voltages were unchanged, while the atrial and ventricular impedances significantly decreased. These results suggest that an important role in the phenomenon occurs by impedance variation at the interface between the pulse generator and body tissue.

Aged↗