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Biomedical subjects

S Nardi

Publications and source records attributed to S Nardi.

At least 19 recordsLinked to original sources
PubMed2007

The auxin-like activity of humic substances is related to membrane interactions in carrot cell cultures.

A detailed characterization of two humic fractions was performed: One with low relative molecular mass (LMr<3,500 Da) and one with high relative molecular mass (HMr>3,500 Da). Distinct (1)H NMR spectroscopic patterns were observed for the two fractions. HMr showed an aromatic proton region, an intense and broad region (3.0-5.0 ppm) attributed to sugar-like and polyether components, and an intense doublet at 1.33 ppm (identified as protons of the beta-CH(3) in lactate). In contrast, LMr did not show resonances due to aromatic protons and was characterized by a broad unresolved region, assigned to sugar-like components. The (13)C NMR spectra showed that the LMr humic fraction was richer in carboxylic and aliphatic C groups compared to HMr fraction. These substances were fluorescein-labeled [fluorescein isothiocyanate (FITC)], and their interaction with carrot cells in culture was monitored for 10 d, and compared to FITC-indole-3-acetic acid (IAA) to clarify their mechanisms of biological activity. After different incubation times, fluorescein staining of carrot cells and decrease of fluorescein concentration in the culture medium were evaluated. Fluorescent membrane staining was only present in IAA and the LMr humic fraction treated cell cultures. A consequential decrease of fluorescein concentration in the culture media was also observed. Pretreatment of carrot cells with unconjugated IAA or LMr humic fraction markedly reduced fluorescein staining of both FITC-IAA and FITC-LMr humic fraction. Blocking tests gave indirect evidence of possible binding of the LMr humic fraction to IAA cell membrane receptors. These results indicate that the two humic fractions behave differently. Only LMr humic fraction, like IAA, interacts with cellular membranes in carrot cell cultures.

Cell Membrane↗
PubMed2006

Chemical and biological characterization of dissolved organic matter from silver fir and beech forest soils.

Despite a growing attention to the dissolved organic matter (DOM) in terrestrial ecosystems and evidence of the fact that vegetation affects the quality of both undissolved and dissolved organic matter in soil, the role of DOM as a biological indicator is still poorly understood. In this work, the fertility of 59 sites, divided into eight key alliances of the order Fagetalia sylvaticae Pawl., was studied considering chemical and biological parameters such as soil DOM, hormone-like activity, low-molecular-weight (LMW) aliphatic and phenolic acids, and floristic data. Both non-parametric tests and principal component analysis (PCA) revealed differences between silver fir and beech forests and within each type of forest. There were also differences between neutrophilous and acidophilous types. What's more, PCA reveals the dominance of the auxin (IAA)-like activity, and of some phenolic acids in distinguishing the acidophilous beeches (ACI) form the other types, whereas the gibberellin (GA)-like activity is more relevant in neutrophilous conditions such as thermophilous (THE) and mesophilous (MESO) beeches and montane (MO), high montane (HMA), high montane (HMC) silver fir forests. The GA-like activity is also related to the succinic, fumaric, malonic, and l-malic acids in the MO, HMA and HMC silver fir forests. Moreover, the role of LMW aliphatic acids in mobilizing the hormone-like activity, which improves forest growth, is stressed. The growth of seedlings of Picea abies was influenced by the phenolic acid content. At concentrations between 1 and 100 microM, phenylacetic and protocatechuic acids inhibited root growth to the same extent as indoleacetic acid, while p-hydroxybenzoic acid had a stimulating effect comparable to that of gibberellic acid. The aliphatic and phenolic acids appear to be related to plant strategies that influence soil fertility affecting plant growth through rhizodeposition. The role of LMW aliphatic and phenolic acids as molecular markers of ecosystem function is noted.

Abies↗
PubMed2005

Pancreas transplantation: problems and prospects in intensive care units.

AIM: The aim of this study is to describe personal experience in the intensive management of patients with severe diabetes undergoing pancreas transplantation. METHODS: Clinical records of subjects consecutively undergoing an isolated or combined pancreas transplant have been examinated. RESULTS: During the considered period, 10 patients received an isolated pancreas transplant and 43 a simultaneous kidney-pancreas transplantation (SPKT), including 6 using a kidney from a living donor. The mean stay in the Intensive Care Unit (ICU) was 4.7 days: 52 patients (98.2%) were transferred to the Surgical Department, whereas one (1.8%) belonging to the SPKT group died with a non-functioning graft. Ten patients (18.6%) were re-admitted because of the onset of late complications, including one SPKT who died of sudden cardiac death with functioning grafts. Arterial hypertension appeared in 51% of the recipients, and 5.6% experienced at least one hypotensive episode. Cardiac rhythm alterations were diagnosed in 5 subjects (9.4%), and myocardial ischemia in 9 (17%). CONCLUSIONS: Pancreas transplantation is a therapeutic option that can improve patients' quality of life by also slowing down the evolution of diabetes; however, it is important to bear in mind the associated risks. The best results are obtained in patients in whom the disease has not already seriously impaired the function of the various target organs.

Adult↗
PubMed2004

Cardiac evaluation for simultaneous pancreas-kidney transplantation and incidence of cardiac perioperative complications: preliminary study.

Type I diabetes mellitus (IDDM) is associated with an increased cardiovascular risk, and eligibility protocols for simultaneous pancreas-kidney transplantation (SPKT) are consequently accurate for preoperative cardiovascular assessment. According to our algorithm, coronary angiography in SPKT candidates is indicated for patients not only experiencing previous cardiac events or symptoms, but also those with long-standing diabetes (more than 25 years) and/or age over 45 years. Furthermore, a basal transthoracic echocardiographic exam (TTE) is performed to assess cardiac volumes, left ventricular mass, systolic function, and kinesis. The aims of this study were to evaluate perioperative cardiac morbidity and mortality in 18 SPKT-eligible patients, divided into two groups on the basis of the presence/absence of angiographically evident coronary artery disease (CAD), as well as to assess the impact of left ventricular hypertrophy (LVH) on cardiac complications. Cardiac intraoperative morbidity and mortality and postoperative mortality and major morbidity were absent; minor cardiac morbidity consisted only of silent ischemic ECG alterations, without significant differences between groups, although the incidence seemed to be higher in the CAD-positive population. LVH detected preoperatively by TTE exam also failed to correlate with the incidence of such complications. Selection of SPKT candidates by coronary angiography may have positive effects on perioperative cardiac morbidity and mortality. A larger sample size is needed to give the study statistical power. Medium- and long-term follow-up studies are warranted to evaluate the effects of preoperative selection on survival rates.

Adult↗
PubMed2002

Biological activity of soil organic matter mobilized by root exudates.

In order to study the biological activity of soil organic matter mobilized by agrarian (Zea mays: cultivars Mytos and Samantha) and forest (Picea abies Karst. and Pinus sylvestris L.) root exudates, two different soils, an Eutric Cambisol (EC) and a Rendzic Leptosol (RL), were considered. Soil organic matter extracts were obtained by treating the soils with water (control) or plant root exudates. The extracts were characterized by hormone-like activities and gas chromatographic/mass spectrometric (GC/MS) measurements. Their effects on the nitrogen metabolism in maize seedlings were evaluated. The nitrogen organification in the maize seedlings has been greatly stimulated by all the organic acid extracts from the agrarian soil, while the extracts from the forest soil had no influence upon the metabolism; this indicated a probable link between the plant and the environment. The different biological activities of the extracts are discussed.

Gas Chromatography-Mass Spectrometry↗
PubMed2002

[Pharyngeal and laryngeal hamartoma: case report].

In this report a case of laryngeal hamartoma is presented. Macroscopically this lesion is quite similar to a tumor but is actually a malformation derived from an error in the development of a healthy organ. Histologically, the hamartoma is composed of a proportionally abnormal mixture of tissues as compared to what is normally present in its anatomic site. The lesion is extremely rare and usually appears in the head and neck district, spleen, pancreas, lung and liver. The diagnosis is essentially based on histological examination. The treatment of choice consists of surgery and periodic follow-up. Differential diagnosis must consider other rare neoplasms such as rhabdomyoma and teratoma.

Female↗
PubMed2001

Atrial electroanatomic remodeling after circumferential radiofrequency pulmonary vein ablation: efficacy of an anatomic approach in a large cohort of patients with atrial fibrillation.

BACKGROUND: Circumferential radiofrequency ablation around pulmonary vein (PV) ostia has recently been described as a new anatomic approach for atrial fibrillation (AF). METHODS AND RESULTS: We treated 251 consecutive patients with paroxysmal (n=179) or permanent (n=72) AF. Circular PV lesions were deployed transseptally during sinus rhythm (n=124) or AF (n=127) using 3D electroanatomic guidance. Procedures lasted 148+/-26 minutes. Among 980 lesions surrounding individual PVs (n=956) or 2 ipsilateral veins with close openings or common ostium (n=24), 75% were defined as complete by a bipolar electrogram amplitude <0.1 mV inside the lesion and a delay >30 ms across the line. The amount of low-voltage encircled area was 3594+/-449 mm(2), which accounted for 23+/-9% of the total left atrial (LA) map surface. Major complications (cardiac tamponade) occurred in 2 patients (0.8%). No PV stenoses were detected by transesophageal echocardiography. After 10.4+/-4.5 months, 152 patients with paroxysmal AF (85%) and 49 with permanent AF (68%) were AF-free. Patients with and without AF recurrence did not differ in age, AF duration, prevalence of heart disease, or ejection fraction, but the LA diameter was significantly higher (P<0.001) in permanent AF patients with recurrence. The proportion of PVs with complete lesions was similar between patients with and without recurrence, but the latter had larger low-voltage encircled areas after radiofrequency (expressed as percent of LA surface area; P<0.001). CONCLUSIONS: Circumferential PV ablation is a safe and effective treatment for AF. Its success is likely due to both PV trigger isolation and electroanatomic remodeling of the area encompassing the PV ostia.

Atrial Fibrillation↗
PubMed2000

Soil organic matter mobilization by root exudates.

In order to study the different soil organic matter mobilisation by agrarian (Zea mais: cultivars Paolo and Sandek) and forest (Picea abies Karst. and Pinus sylvestris L.) root exudates, three different soils (Dystric Spodic Cambisol--S1, Haplic Luvisol--S2 and Calcaric Cambisol--S3) have been considered. Treating the soils with water (control) or plant root exudates, soil organic matter extracts were obtained. The extracts were characterised by hormone-like activities and gas chromatographic/mass spectrometric (GC/MS) measurements. Water extract and plant root exudates exhibited no hormone-like activity, while the other soil-extracts were endowed with a different hormone-like behaviour. GC/MS data indicated that in the acid soils (S1) Sandek and Picea abies exudates showed a greater ability in extracting organic acid isomers (Cl4COOH, Cl5COOH and Cl7COOH), while in neutral soils (S3) all the exudates were active in separating organic acids. In intermediate conditions (S2), Picea abies and Pinus sylvestris exudates liberated C15COOH isomers, Paolo C11COOH isomers, while Sandek was not effective. The different role of plant root exudates in mobilising bio-molecules from the bulk of the soil is proposed.

Acids↗
PubMed2000

Pharmacokinetics and tissue penetration of vancomycin in patients undergoing prosthetic mammary surgery.

Vancomycin concentrations in periprosthetic breast tissues were evaluated in 24 women undergoing reconstructive surgery after mastectomy for breast cancer. Patients were given a single prophylactic dose of vancomycin (1 g iv) 1-8 h before surgery, and mean capsular and pericapsular tissue concentrations were measured by HPLC. Vancomycin was not detectable in the majority of patients belonging to the 1-3 h post-dose groups, whereas in the 4-8 h post-dose groups, mean capsular and pericapsular concentrations were as follows: at 4 h, 4.0 mg/kg and 5.9 mg/kg; at 6 h, 4.1 mg/kg and 4. 8 mg/kg; at 8 h, 5.9 mg/kg and 11.1 mg/kg, respectively. Vancomycin tissue concentrations thus were equal to or exceeded the breakpoint of 4 mg/L in most samples collected 4-8 h after dosing. In conclusion, our data suggest that appropriate timing of vancomycin prophylaxis should be considered to allow the maintenance of adequate tissue concentrations throughout the surgical procedure.

Aged↗
PubMed1999

Deterioration of protein fraction by Maillard reaction in dietetic milks.

The development of the Maillard reaction in pasteurized, UHT and in-bottle sterilized dietetic milks was studied. In these products damage caused by heat treatments could increase as a result either of the addition of various ingredients or of manufacturing processes that alter their content of reducing carbohydrates. Protein damage was evaluated by measuring furosine by reversed-phase ion-paired HPLC. The levels of furosine detected made it possible to assess the amounts of biologically unavailable lysine. In all milks analysed blocked lysine values were < 340-350 mg/g total lysine, the level at which lysine becomes the limiting amino acid in milk. Pasteurized dietetic milks had levels of blocked lysine similar to that in ordinary pasteurized cows' milk. In some UHT and in-bottle sterilized dietetic milks their different composition resulted in an increase in the blocked lysine content. In some in-bottle sterilized milks, protein damage greatly reduces the beneficial effects of milk as a dietary supplement. Lactose-free milks, which are more susceptible to protein deterioration because of their higher content of reducing carbohydrates, were also analysed after storage at 20 degrees C and at < or = 4 degrees C. At the end of their recommended storage times, they contained limited amounts of blocked lysine only if they had been stored at < or = 4 degrees C.

Animals↗
PubMed1999

[Massive thrombosis of the superior mesenteric artery following splenectomy. A coincidence?].

Postsplenectomy thrombocytosis is a well recognised complication about which there is little published information. Therefore, postoperative complications of this effect have not been emphasised. An experience with a case of superior mesenteric artery thrombosis and small intestinal ischemia following splenectomy is reported. We reviewed the literature, but we wasn't able to find any case, whereas the association between splenectomy and mesenteric or portal vein thrombosis is well known. Pathogenesis of postsplenectomy thrombocytosis is poorly understood. Theories to explain it include removal of the splenic sequestration effect or removal of a regulatory humoral factor produced by the spleen. Both mechanisms could be operative at the same time, explaining the observation that some patients develop thrombocytosis related complications soon after surgery, while others after a longer time. The literature on the thromboembolic risk of postsplenectomy thrombocytosis is inconclusive and no studies have established whether patients with thrombocytosis following splenectomy should be treated with anticoagulants or antiplatelet medications in order to prevent thrombotic complications. Certainly, a recommendation for the routine use of these drugs cannot be made on the basis of one observation, but the need for controlled studies must be stressed.

Aged↗
PubMed1999

[Hürthle cell carcinoma and "insular" carcinoma: uncommon varieties of thyroid carcinoma].

The Hürthle cell carcinoma and "insular" carcinoma are two uncommon types of thyroid carcinoma. These neoplasms do not present accurate characteristics as to incidence, natural history, pathophysiology and therapies. Two cases are presented: the first was submitted to near-total thyroidectomy for Hürthle cell carcinoma, the second to total thyroidectomy for "insular" carcinoma with bone and lung metastases. Some literature previous studies on pathophysiology and natural history of both tumors are discussed. At the end, personal trend on the surgical treatment of these two thyroid neoplasms is presented: total thyroidectomy for CCh and "insular" carcinoma, and near-total thyroidectomy for Hürthle cell adenoma.

Adenocarcinoma↗
PubMed1998

Response of uncomplicated falciparum malaria to oral chloroquine and quinine in Burundi highlands.

The in vivo response of falciparum malaria to oral chloroquine and quinine was evaluated in two identical hospital-based, comparative open trials carried out 2 years apart in the same seasonal period at a hospital located in the highlands of Northern Burundi. Children aged 0-14 with uncomplicated falciparum malaria were administered either chloroquine, at 25 mg/kg over 3 days, or quinine, at 10 mg/kg per 8 hourly for 5 days (alternate allocation) and treatment response was evaluated by the WHO 7-day test. In the first study (1992/1993) 472 patients qualified for analyses (211 in the chloroquine and 261 in the quinine group), as compared to 249 subjects in the second study (1994/1995). In each study, the response to quinine was significantly higher than that to chloroquine (P = 0.004 and < 0.001, respectively). While the response to quinine showed insignificant changes over time (95.8 vs. 92.9%), chloroquine was found to be significantly less effective in the second study as compared to the first (77.8 vs. 63.1%; OR (95% CI) 2.04 (1.21-3.43)). Such decline in chloroquine efficacy was attributable to the age group < 5 years of age, where response to chloroquine decreased from 72.9% in 1992/93 to 56% in 1994/1995. Uncontrolled chloroquine use, which spread after the onset in late 1993 of the still ongoing ethnic fighting, appears to be the most likely reason for such a decrease in chloroquine efficacy. Chloroquine resistance has long been known to be present in the hyperendemic lowlands of Burundi, but no data have so far been reported on the response to antimalarials in the highlands of the country. These findings should be considered when deciding on drug policies for the treatment of falciparum malaria in Burundi.

Administration, Oral↗
PubMed1998

Trace elements in human scalp hair and soil in Irian Jaya.

Pb, Cd, and Ni contents were determined in the scalp hair of the Asmat of Irian Jaya (Indonesian New Guinea) on 35 adult subjects. These data are presented together with those of Al, Ca, Ti, Fe, Cu, Zn and Sr, which were determined in previous research on the same group. Hair samples were analyzed by EDXRS and ICP. Trace elements were also determined in 12 soil samples from the same area by EDXRS (Al, Si, K, Ca, Fe) and ICP (Cu, Sr, Ti), and by AAS (Cd, Ni, Pb). When hair element levels are compared and discussed with those of other New Guinea populations, acculturated and nonacculturated tropical groups, populations from Western countries and from polluted areas, and "recommended levels" in the literature, they greatly exceed Western levels and generally fit those of other New Guinea populations, stressing the importance of common environment, subsistence, and behavior. The results of soil analyses are consistent with the presence of those elements in hair, and their quantitative distribution follows a common trend. Metal mobility in soil, patterns of absorption, and transfer from soil to plants and to humans are considered here.

Adolescent↗
PubMed1998

[Colo-uterine fistula, a complication of sigma diverticulitis].

The colo-uterine fistula is a rare complication of diverticular disease of the colon; the literature review has shown only few well studied cases. The fistula, among the complications of the sigma diverticulitis, is 20% of the observed cases; generally, the bladder is the most involved organ, but also the skin or gut can be interested. If we consider the aetiology of the colo=uterine fistula of the observed case, the presence of the sigma locked stenosis with an endocolic pressure increase, associated with a peridiverticulitis condition, seems to have a relevant rule. The clinical symptomatology is represented by vague abdominal pain localized in particular in the left iliac cavity and by emission of blood, purulent material and stools from the vagina. The diagnosis of colo-uterine fistula is not easily reached: barium enema, Fallopian tube endoscopy and colon endoscopy not always allow to visualize in a right manner the fistula and only the oral administration of non-absorbable substances to be searched in the vaginal tampon, clear each doubt. Regarding the therapy to be carried out, we think that, colic resection en bloc with the uterus is the treatment of choice, while, in emergency, the Hartman operation is the most suitable to avoid the beginning of septic complications.

Aged↗
PubMed1997

Autonomic nervous system imbalance and left ventricular systolic dysfunction as potential candidates for arrhythmogenesis in Becker muscular dystrophy.

We evaluated the arrhythmic profile in a population of 20 Becker muscular dystrophy (BMD) patients searching for possible correlations between the severity of the arrhythmic events, the cardiac autonomic balance (assessed by heart rate variability analysis in the time domain) and the degree of left ventricular systolic impairment. A population of 14 male healthy individuals served as the control group. BMD subjects exhibited lower values of SDNN (P=0.013), SDANN index (P=0.008) and 24-h mean heart rate (P=0.002). The total number of premature ventricular beats (totPVB) and the number of PVB out of 1000 heartbeats (PVB/1000) appeared also higher in BMD subjects (P=0.05 and P=0.046, respectively). No difference was found in terms of 24-h mean QTc and 24-h longest QT among the two groups. TotPVB and PVB/1000 were inversely related to both the ejection fraction (r= -0.620, P=0.004 and r= -0.517, P=0.019) and to the shortening fraction (r= -0.568, P=0.009 and r= -0.469, P=0.037). Twenty-four-h mean QTc was also inversely related to both the ejection fraction (r= -0.520, P=0.019) and the fractional shortening (r= -0.491, P=0.028). These data suggest that in BMD there is cardiac autonomic imbalance characterized by sympathetic predominance and an increased susceptibility to ventricular arrhythmias, even in the absence of overt cardiomyopathy. Furthermore, the severity of the arrhythmic profile in BMD appears closely related to the degree of left ventricular systolic dysfunction.

Adult↗
PubMed1997

Intravenous immunoglobulin versus corticosteroid in treatment of Graves' ophthalmopathy.

We compared the effectiveness of systemic corticosteroids with the use of high-dose intravenous immunoglobulin (IVIG) in the treatment of Graves' ophthalmopathy. This was performed as a prospective, nonrandomized study including a blinded ophthalmological and orbital computed tomographic (CT) evaluation. The two groups of patients were not significantly different in relation to sex composition, age distribution, duration of Graves' disease, and ophthalmopathy and previous hyperthyroidism. All patients were followed up by endocrinologic evaluation and blinded ophthalmological (before therapy = B, at the end of therapy = E, and 6 months after the end = 6M) and orbital CT (B and E) evaluations. Twenty-seven patients treated with IVIG were followed up after the end of treatment for an average of 21 months (range 12 to 48 months). Soft tissue involvement (NOSPECS) improved or disappeared in 32 of 35 (90%) patients treated with IVIG and in 25 of 27 (92.5%) patients treated with corticosteroids. Diplopia improved or disappeared in 22 of 29 (75%) patients treated with IVIG and in 16 of 20 (80%) patients treated with corticosteroids. The results observed by clinical evaluation were confirmed with orbital CT score in 30 IVIG patients and in the corticosteroid-treated patients; a significant reduction of extraocular muscle thickness was observed after treatment in both groups. Proptosis improved or disappeared in 20 of 31 (65%) patients treated with IVIG and in 15 of 24 (62%) patients treated with corticosteroids. Mean values of proptosis evaluated by Hertel's exophthalmometer showed a slight reduction both in IVIG as well as in corticosteroid-treated patients. It is interesting to observe that in 28 IVIG-treated patients in whom it was possible to evaluate soft tissue involvement, proptosis and diplopia in the period between the fifth and sixth month from the start of therapy, the most important part of the amelioration (if responders) was already obtained at that time. Responder patients were defined in relation to the decrease in the highest NOSPECS class or grade. Among IVIG-treated patients 26 of 34 (76%) responded; while in the corticosteroid group 18 of 27 (66%) responded to treatment. The prevalences of patients who responded to the treatments were not significantly different in the two groups (Chi-square). The initial values of the subjective eye score were similar in the two groups, and a significant reduction was observed in both. Major side effects requiring discontinuation of the corticosteroid therapy were observed in two patients with hemorrhagic gastritis and in one patient with manic-depressive psychosis. Among 15 patients submitted to the evaluation of bone mineral content before and after corti-costeroid therapy, 4 presented signs of osteoporosis and 3 a reduction of bone mineral content. Moderate and minor side effects were more frequently noted in steroid-treated patients than in the IVIG group. These data suggest that IVIG is safe and effective in reducing the eye changes in patients with Graves' ophthalmopathy.

Adrenal Cortex Hormones↗