Biomedical subjects

F Ferri

Publications and source records attributed to F Ferri.

At least 19 recordsLinked to original sources

PubMed2006

S.A.M., the Italian Martian simulation chamber.

The Martian Environment Simulator (SAM "Simulatore di Ambiente Marziano") is a interdisciplinary project of Astrobiology done at University of Padua. The research is aimed to the study of the survival of the microorganisms exposed to the "extreme" planetary environment. The facility has been designed in order to simulate Mars' environmental conditions in terms of atmospheric pressure, temperature cycles and UV radiation dose. The bacterial cells, contained into dedicated capsules, will be exposed to thermal cycles simulating diurnal and seasonal Martian cycles. The metabolism of the different biological samples will be analysed at different phases of the experiment, to study their survival and eventual activity of protein synthesis (mortality, mutations and capability of DNA repairing). We describe the experimental facility and provide the perspectives of the biological experiments we will perform in order to provide hints on the possibility of life on Mars either autochthonous or imported from Earth.

Bacteria↗

PubMed2006

Interactions between general and regional anesthesia.

Neuraxial blockade is commonly used to abolish sensations elicited by noxious stimuli during surgical procedures. Proven advantages of combined anesthesia include early recovery from general anesthesia and postoperative analgesia, together with likely decreases in blood loss, cardiac dysrhythmias, or ischemic events and postoperative deep vein thrombosis. The side effects of the technique are related to the dose or site of local anesthetic administration and to light general anesthesia, which can result in awareness during surgery. Varying degrees of synergistic interactions have been reported among the drugs used to achieve the anesthetic state. Spinal anaesthesia appears to have sedative effects, and local anesthetics used for neuraxial blockade have been found to reduce the induction and maintenance dosage of midazolam, thiopental, propofol and inhaled anesthetics. The growing interest in combining local and general anesthesia has led to studies investigating possible interactions between general anesthesia and local anesthetics administered via spinal or epidural routes. Neuraxial blockade reduces sedative and anesthetic requirements by decreasing ascending sensory input into the brain. This has important clinical implications, as anesthetists should expect to reduce anesthetic and sedative drug doses during neuraxial blockade, unless the blockade involves lower dermatomes alone. Clinical practice of anesthesia is a polypharmacy, wherein the anesthetic state is the net result of the action of different drugs and their interaction in the presence of a surgical stimulus.

Anesthetics, General↗

PubMed2005

In situ measurements of the physical characteristics of Titan's environment.

On the basis of previous ground-based and fly-by information, we knew that Titan's atmosphere was mainly nitrogen, with some methane, but its temperature and pressure profiles were poorly constrained because of uncertainties in the detailed composition. The extent of atmospheric electricity ('lightning') was also hitherto unknown. Here we report the temperature and density profiles, as determined by the Huygens Atmospheric Structure Instrument (HASI), from an altitude of 1,400 km down to the surface. In the upper part of the atmosphere, the temperature and density were both higher than expected. There is a lower ionospheric layer between 140 km and 40 km, with electrical conductivity peaking near 60 km. We may also have seen the signature of lightning. At the surface, the temperature was 93.65 +/- 0.25 K, and the pressure was 1,467 +/- 1 hPa.

Journal Article↗

PubMed2005

PCDD and PCDF intake through consumption of locally produced seafood by Venice lagoon residents: elements for risk management.

Explore the source record for details and available documents.

Animals↗

PubMed2005

High-resolution ghost image and ghost diffraction experiments with thermal light.

High-resolution ghost image and ghost diffraction experiments are performed by using a single classical source of pseudothermal speckle light divided by a beam splitter. Passing from the image to the diffraction result solely relies on changing the optical setup in the reference arm, while leaving the object arm untouched. The product of spatial resolutions of the ghost image and ghost diffraction experiments is shown to overcome a limit which seemed to be achievable only with entangled photons.

Journal Article↗

PubMed2005

Nefopam or clonidine in the pharmacologic prevention of shivering in patients undergoing conscious sedation for interventional neuroradiology.

The aim of this randomised, double-blind study was to investigate the usefulness of intravenous nefopam, clonidine or placebo in preventing shivering in patients undergoing conscious sedation for interventional neuroradiological procedures. A total of 101 patients were prospectively enrolled and assigned to one of three groups to receive nefopam, clonidine or placebo. The overall incidence of intra-operative shivering was significantly lower in patients treated with nefopam than in those treated with clonidine or placebo (2/32 (6%) vs. 11/38 (29%), p < 0.02; 2/32 (6%) vs. 24/31 (77%), p < 0.0001, respectively). The number of patients who required ephedrine infusions to maintain a mean arterial pressure of 100 mm Hg was higher in the clonidine group than in the nefopam and placebo groups (18/38 (47%) vs. 5/32 (17%), p < 0.05; 18/38 (47%) vs. 6/31 (19%), p < 0.05, respectively). We found that both nefopam and clonidine significantly lowered the rate and severity of shivering during interventional neuroradiological procedures. Fewer patients in the nefopam group than in the other two groups required vasoactive drugs.

Adult↗

PubMed2004

Heterodyne near-field scattering: a technique for complex fluids.

We implemented the heterodyne near-field scattering (HNFS) technique [Appl. Phys. Lett. 81, 4109 (2002)]], showing that it is a fairly valid alternative to traditional elastic low-angle light scattering and quite suitable for studying complex fluids such as colloidal systems. With respect to the original work, we adopted a different data reduction scheme, which allowed us to improve significantly the performance of the technique, at levels of sensitivity and accuracy much higher than those achievable with classical low-angle light scattering instrumentation. This method also relaxes the requirements on the optical/mechanical stability of the experimental setup and allows for a real time analysis. The HNFS technique has been tested by using calibrated colloidal particles and its capability of performing accurate particle sizing was ascertained on both monodisperse and bimodal particle distributions. Nonstationary samples, such as aggregating colloidal solutions, were profitably studied, and their kinetics quantitatively characterized.

Journal Article↗

PubMed2002

[The use of laryngeal mask airway in esophagogastroduodenoscopy in children].

BACKGROUND: The use of laryngeal mask airway (LMA) for inducing and maintaining sedation during EGDS has never been reported in the literature but for a brief letter written by Gajraj in 1996. This study proposes the use of sevoflurane administered through LMA. METHODS: At the Pediatric Clinic of the University of Rome "La Sapienza" 80 children un-derwent EGDS. After premedication, immediate 8% sevoflurane and 60/40% N2O/O2 induction was delivered. Concentration of sevoflurane was reduced to 1% for maintaining general anesthesia. Heart rate (HR), systemic blood pressure (SBP), respiratory rate (RR), EtCO2 and SpO2 were not invasively monitored. Time for induction, time for emergence as well as complications, if any, were also evaluated. RESULTS: The monitored parameters did not show any significant changes. The time for loss of eyelash reflex and the time for end of induction were of 121+/-15 sec. 3.5+/-1.3 min respectively. The time for emergence was 3.4+/-1.8 min. Only minor complications were reported. CONCLUSIONS: The results obtained show that the use of LMA associated to sevoflurane as single inhaling agent can be a valid technique for EGDS in pediatric patients.

Anesthesia Recovery Period↗

PubMed2001

Gasless laparoscopic-assisted ileostomy or colostomy closure using an abdominal wall-lifting device.

BACKGROUND: Restoration of intestinal continuity in patients with ileostomy after total colectomy or with colostomy after Hartmann's procedure is a major operation. Herein we illustrate the validity of gasless laparoscopically assisted reversal using abdominal wall lifting. METHODS: The operation was performed on 10 patients from February 1997 to May 1999. Seven of them had a left iliac stoma after a Hartmann resection, and three had an ileostomy after total colectomy. RESULTS: The laparoscopic reversal was completed in eight patients; the two others were converted to an open procedure. Three major complications occurred (30%). There were no deaths. The average operation time was 192 min (range, 125-265). Time of discharge from surgery averaged 9.5 days. Mean follow-up of these patients was 12 months and negative. CONCLUSIONS: Laparoscopically assisted ileo- or colorectal anastomosis without pneumoperitoneum and using a laparotenser can be considered for the reversal of patients with ileostomy or colostomy. Even taking the high rate of intraoperative or postoperative complications into consideration, the advantages that make such a laparoscopic approach suitable include reduced trauma related to a second major abdominal operation, reduced postoperative pain, and fewer cutaneous tissues exposed to bacterial contamination. Moreover, the use of a laparotenser makes it possible to operate on elderly patients with cardiovascular diseases. In the absence of pneumoperitoneum, it becomes possible to use traditional instruments, with a consequent reduction in costs.

Abdominal Muscles↗

PubMed2001

Growth kinetics and structure of fibrin gels.

The structure and kinetics of fibrin gels grown from fibrinogen solutions under quasiphysiological conditions, but in absence of Ca++, were investigated by means of elastic light scattering. By combining classical light scattering and low-angle elastic light scattering, an overall wave-vector range of about three decades was spanned, from q approximately 3 x 10(2) to q approximately 3 x 10(5) cm(-1). The scattered intensity distribution of the gels was measured in absolute units and fitted to a single function, which was able to reproduce accurately the data over the entire wave-vector range. From the fitting, it was possible to estimate the average diameter d of the fibrin fibers, the average crossover length xi of the gel, and establish the fractal nature of the gel structure, with a measure of its fractal dimension D(m). The measure of the intensity in absolute units also allowed the estimate of the density rho of the fibrin fibers and provided an independent measure of their size. The kinetics of formation of the gel was described in terms of a simple growth model: the scaffold of the network is formed very early in the course of the gelation process, at a "networking time," t(n), which is much smaller than the time required to form the final gel. At times t>t(n), the gel structure remains substantially unchanged and the successive growth consists only in a thickening of the gel fibers. Gels prepared under the same physical-chemical conditions, but at different fibrinogen concentrations, exhibited rather similar structures and kinetics, showing that the modalities of the gelation process are mainly governed by the solution conditions, and only secondarily by the fibrinogen concentration. For gels at fibrinogen concentration of approximately 0.24 mg/ml, the gel parameters were d approximately 130 nm, xi approximately 27 microm, D(m) approximately 1.3, and rho approximately 0.4 g/cm(3). Our d and rho values are in very good agreement with electron microscopy- and turbidity-derived literature data, respectively, while xi seems to be related to the mesh size of the initial scaffold formed at t(n), rather than to the mesh size of the final aged gel.

Fibrin↗

PubMed2001

Erythropoietin therapy and preoperative autologous blood donation in children undergoing open heart surgery.

We assessed the feasibility and efficacy of subcutaneous erythropoietin alpha (EPO) therapy and preoperative autologous blood donation (ABD) in children undergoing open heart surgery. Thirty-nine children were treated consecutively with EPO (100 U x kg(-1) s.c. three times a week in the 3 weeks preceding the operation and i.v. on the day of surgery) and two ABDs were made (Group 1). As controls to compare transfusion requirements, 39 consecutive age-matched patients who had undergone open heart surgery during the two preceding years were selected (Group 2). In a mean time of 20 (SD 5) days, 96% of scheduled ABDs were performed and only three mild vasovagal reactions were observed. The mean volume of autologous red blood cells (RBC) collected was 6 (1) ml x kg(-1) and the mean volume of autologous RBC produced as a result of EPO therapy before surgery was 7 (3) ml x kg(-1), corresponding to a 28 (11)% increase in circulating RBC volume. The mean volume of autologous RBC collected was not different from that produced [6 (1) vs 7 (3) ml x kg(-1), P=0.4]. Allogenic blood was administered to three out of 39 children in Group 1 (7.7%) and to 24 out of 39 (61.5%) in Group 2. Treatment with subcutaneous EPO increases the amount of autologous blood that can be collected and minimizes allogenic blood exposure in children undergoing open heart surgery.

Adolescent↗

PubMed2001

Early events in the polymerization of fibrin.

The early events in the thrombin-induced formation of fibrin have been studied by the use of stopped-flow multiangle laser light scattering (SF-MALLS). This technological advancement has allowed the recovering, as a function of time with a resolution of about 0.5 sec, of the mean square radius of gyration (Rg2)z and of the molecular weight Mw, and to place an upper bound to the values of the mass/unit length ML. The ionic strength, pH and salt type conditions investigated were all close to physiological, starting with a 50 mM Tris, 104 mM NaCl, pH 7.4 buffer (TBS), to which either 1 mM EDTA-Na2 or 2.5 mM CaCl2 were also added. Fibrinogen was 0.2-0.3 mg/ml and rate-limiting concentrations of thrombin were used (0.05-0.25 NIH units/mg fibrinogen). By plotting (Rg2)z and ML versus Mw on log-log scales, runs proceeding at different velocities and under different solvent conditions could be compared and confronted with model curves. It was found that: (1) within this thrombin range, the mechanism of association does not depend on its concentration, nor on the buffers employed; (2) the (Rg2)z versus Mw curves could all be reasonably fitted with a bifunctional polycondensation scheme involving semiflexible worm-like, double-stranded, half-staggered polymers with persistence length between 200-600 nm, provided that a ratio Q = 16 between the rate of release of the two fibrinopeptides A was employed; (3) the ML versus Mw data seemed more compatible with lower Q values (4 < Q < 8), but their uncertainty prevented a better assessment of this issue; the formation of fibrinogen-fibrin monomer complexes may also play a role in the polymer distributions; (4) in the very early stages (e.g., when Mw < 7 x 10(5)), the (Rg2)z versus Mw data were fitted well only in TBS and at the lowest thrombin concentration, suggesting that a transient, either sequential or concurrent fast second mechanism, involving longer and thinner polymers, may be at work.

Biopolymers↗

PubMed2000

Polymerization of rod-like macromolecular monomers studied by stopped-flow, multiangle light scattering: set-up, data processing, and application to fibrin formation.

Many biological supramolecular structures are formed by polymerization of macromolecular monomers. Light scattering techniques can provide structural information from such systems, if suitable procedures are used to collect the data and then to extract the relevant parameters. We present an experimental set-up in which a commercial multiangle laser light scattering photometer is linked to a stopped-flow mixer, allowing, in principle, the time-resolved extrapolation of the weight-average molecular weight M(w) and of the z-average square radius of gyration (z) of the polymers from Zimm-like plots. However, if elongated structures are formed as the polymerization proceeds, curved plots rapidly arise, from which M(w) and (z) cannot be recovered by linear fitting. To verify the correctness of a polynomial fitting procedure, polydisperse collections of rod-like or worm-like particles of different lengths, generated at various stages during bifunctional polycondensations of rod-like macromolecular monomers, were considered. Then, the angular dependence of their time-averaged scattered intensity was calculated in the Rayleigh-Gans-Debye approximation, with random and systematic noise also added to the data. For relatively narrow size distributions, a third-degree polynomial fitting gave satisfactory results across a broad range of conversion degrees, yielding M(w) and (z) values within 2% and no greater than 10-20%, respectively, of the calculated values. When more broad size distributions were analyzed, the procedure still performed well for semiflexible polymers, but started to seriously underestimate both M(w) and (z) when rigid rod-like particles were analyzed, even at relatively low conversion degrees. The data were also analyzed in the framework of the Casassa approximation, from which the mass per unit length of the polymers can be derived. These procedures were applied to a set of data taken on the early stages of the thrombin-catalyzed polymerization of fibrinogen, a rod-like macromolecule approximately 50 nm long. The polymers, grown in the absence of Ca(2+) by rate-limiting amounts of thrombin, appeared to be characterized by a much broader size distribution than the one expected for a classical Flory bifunctional polycondensation, and they seem to behave as relatively flexible worm-like double-stranded chains. Evidence for the formation of fibrinogen-fibrin monomer complexes is also inferred from the time dependence of the mass/length ratio. However, our data are also compatible with the presence of limited amounts of single-stranded structures in the very early stages, either as a secondary, less populated pathway, or as transient intermediates to the classical double-stranded fibrils.

Chromatography, High Pressure Liquid↗

PubMed2000

Incisional hernia and fascial defect following laparoscopic surgery.

Complications involving the abdominal wall, particularly incisional hernias, were not expected when laparoscopic procedures were first introduced. With the increasing number of laparoscopies in abdominal surgery, more incisional hernias are observed. The authors report 13 cases of umbilical incisional hernia, which occurred late after laparoscopic cholecystectomy, and one case of omental procidentia through a lateral port, which occurred early after laparoscopic hernia repair with the transabdominal preperitoneal technique. There are 4 men and 10 women (mean age, 59.8 years; range, 40-74 years). Between March 1991 and December 1997, a total of 1,287 patients underwent laparoscopic operations at the Surgical Department of the Gradenigo Hospital in Turin, Italy. Incisional hernia incidence is 1%. Risk factors, such as chronic bronchitis or weight increase, which give rise to endoabdominal pressure, are present in some cases. Malnutrition may have a major role in many cases. Calculi larger than 15 mm are also seen frequently. Postlaparoscopy incisional hernia is generally a minor complication--only once did its occurrence cause a strangulated hernia. All precautions, including fascial suturing, must be taken to reduce the 1% incidence of postoperative incisional hernias.

Adult↗

PubMed2000

[Spigelian hernia: an up-to-date].

Nine cases of Spigelian hernia occurred and surgically treated in the years 1992-1997 are reported. Spigelian hernias were observed in 5 females and 3 males with mean age of 62.1 years (range 49-70). In 5 cases prosthetic repair has been done with preperitoneal mesh and a very good outcome. In a 61 years old obese female spigelian hernia was bilateral. Her left sided hernia needed an emergency operation for strangulation. Hernia has been repaired by simple suture and recurred early. For the diagnosis of Spigelian hernia it is essential to remember it inside the "Spigelian belt". The satisfactory results obtained at present by prosthetic repair are underlined.

Aged↗

PubMed1999

Positive and sustained effects of highly active antiretroviral therapy on HIV-1-associated neurocognitive impairment.

OBJECTIVES: To determine whether highly active antiretroviral therapy (HAART) is effective in HIV-associated neurocognitive impairment. DESIGN: An open label, prospective, observational study. METHODS: Since April 1996, 116 patients with advanced HIV infection, reverse transcriptase inhibitor (nRTI) experienced but protease inhibitor (PI) naive, were screened for the presence of neurocognitive impairment. Ninety patients with confounding neurological illness, opportunistic infections or drug abuse were excluded. The remaining 26 patients underwent comprehensive neuropsychological testing, and laboratory measures before, after 6 and after 15 months of treatment with one PI plus two nRTI. RESULTS: The prevalence of neurocognitive impairment decreased from 80.8% (baseline) to 50.0% (P<0.05) (sixth month) and to 21.7% (P<0.001) (15th month). Among the functions explored, the impairment of concentration and speed of mental processing decreased from 65.4 to 21.7% (P<0.01) and of memory impairment from 50 to 8.7% (P<0.01). Comparing baseline with the sixth and 15th month raw scores, a statistically significant improvement was seen in measures exploring concentration and speed of mental processing (P<0.05), mental flexibility (P<0.05), memory (P<0.05), fine motor functions (P<0.05) and visuospatial and constructional abilities (P<0.01). After 6 months of HAART patients with a normal neuropsychological examination had lower mean plasma viraemia (2.95 versus 3.97 log copies/ml, P<0.05) and greater mean log plasma HIV RNA changes from baseline (-1.84 versus -0.83 log copies/ml, P<0.05) than neuropsychologically impaired subjects. CONCLUSION: HAART produces a positive and sustained effect on neurocognitive impairment in HIV-infected patients. A reduction of plasma viral load was associated with the regression of neuropsychological test abnormalities.

Adult↗

PubMed1999

Incisional hernia and fascial defect following laparoscopic surgery.

Adult↗

PubMed1998

Sporadic hepatitis C virus infection: a case-control study of transmission routes in a selected hospital sample of the general population in Italy.

A case-control study was performed on 9,175 Italian adult outpatients in 5 hospitals in Rome. The study was carried out to clarify the role of some less investigated risk factors (RF) in the spread of hepatitis C virus (HCV) infection. All subjects were contacted by interviewers, who completed a questionnaire. Their sera were stored and subsequently tested for both HCV and hepatitis B virus core (HBc) antibodies. 365 subjects, positive for anti-HCV and anti-HBc-negative, and who had denied intravenous drug use (IDU) (cases) were compared with an equal number of suitable random controls negative for anti-HCV and anti-HBc. Gender, age and region of birth and residence were matched. The prevalence of 13 RFs were statistically compared by univariate and multivariate analysis. A positive anti-HCV test was significantly associated, by multivariate analysis with intravenous treatments and minor surgical procedures (both before 1975) (p < 0.001), blood transfusions (before 1991) (p < 0.01), diabetes (p < 0.01), and deliveries in hospital (p < 0.05) (both before 1975). After 1975 (1991 for transfusions), all associations lost their significance. Intra-familial (sexual and non sexual), occupational RFs and dental care were not significantly associated with the presence of anti-HCV. We suggest that non-disposable syringes, commonly used until 1975 in Italy for i.v. treatments, have been the major route for HCV transmission in Italy among non-IDU subjects.

Adult↗