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Biomedical subjects

T Ferri

Publications and source records attributed to T Ferri.

At least 19 recordsLinked to original sources
PubMed2006

Absorption of selenium by Lactuca sativa as affected by carboxymethylcellulose.

Several organic compounds of high molecular weight present in soil interact with selenium and may act as active binding agents affecting its availability in soil, and, consequently, selenium uptake by plants. This study is aimed at investigating the effects of polysaccharides on selenium speciation in soil and on selenium absorption by Lactuca sativa L. plants. Three-week-old seedlings were transplanted into pots filled with soil, and sodium selenite at rates of 1.5 and 5mgSekg(-1) of soil, or sodium selenate at a rate of 1.5mgSekg(-1) of soil were applied. Carboxymethylcellulose (CMC) was added to the soil at rates of 0, 3 and 30mgkg(-1) of soil. After 48 and 110d from transplanting plants were harvested, separated into root and shoot, and fresh and dry matter weights were recorded. Total selenium was determined in both soil and plant samples. A sequential extraction was used to investigate the different Se oxidation states and assess the availability of Se in soil after the final harvesting. Both selenite and selenate were absorbed by roots, but plants amended with Se(VI+) showed higher selenium concentration than plants amended with Se(IV+). Selenite appears to be less mobile than selenate both in soil and plants. The addition of carboxymethylcellulose to soil decreased the amount of selenium absorbed by plants. CMC interacted with Se, making it less mobile as evidenced by the increase in the insoluble fractions. The insoluble Se forms in soil may represent environmental Se sinks potentially available for plants if the substrate is re-used for subsequent growth cycles and selenium species are mobilized as a result of biological and chemical processes.

Carboxymethylcellulose Sodium↗
PubMed2005

Salvage surgery after radiation failure in squamous cell carcinoma of the larynx.

AIM AND BACKGROUND: To investigate patients treated with radiotherapy (RT) for laryngeal squamous cell carcinoma (SCC) in order to estimate the recurrence rate and treatment used as salvage surgery. The survival rate in the group of patients treated with salvage surgery was compared to that of patients who had chemotherapy rather than surgery or who refused any treatment. METHODS: From 1989 to 1999, 185 patients came to our institution for laryngeal SCC. All of them underwent RT as primary treatment. Only patients with a minimum of three years follow-up (n = 143) were included in the study group. RESULTS: The 143 cases included 22 loco-regional recurrences (15.3%) during the minimum three years of follow-up. Recurrence was observed in the larynx in eighteen cases (81.8%), in cervical nodes in one case (4.55%) and in both the larynx and cervical nodes in one case (4.55%). There was peristomal recurrence in two cases (9.1%). Recurrence was observed after an average of 16.3 months. Fourteen patients (63.6%) out of the twenty-two cases of recurrence underwent salvage surgery. Surgery was not performed on the remaining eight patients (36.4%). The global survival rate was 92.3% after three years and 66.6% after five years in the group of patients treated with surgery. The actuarial survival rate was 100% after three years and 83.3% after five years. The global and actuarial survival rate was 20% after three years and 0% after five years in the group of patients who received chemotherapy rather than surgery or who refused any kind of treatment. CONCLUSION: The RT seems to play an important role in the loco-regional control of laryngeal SCC (especially in glottic T1). Salvage surgery for recurrence results in a good survival rate.

Adult↗
PubMed2004

Effects of gastroesophageal reflux disease in laryngeal carcinoma.

Gastroesophageal reflux disease is associated with various otolaryngological disorders. The aim of this retrospective study was to determine the role of gastroesophageal reflux disease in the development of laryngeal squamous cell carcinoma (SCC) in non-smoking and non-drinking patients. The study population consisted of 36 consecutive non-smoking and non-drinking patients with histologically confirmed SCC of the larynx. As a control, a group of 125 lifetime non-smoking and non-drinking cancer-free subjects were selected. Patients with laryngeal cancer had a higher prevalence of gastroesophageal reflux disease than the control subjects (P < 0.0001). Our results confirm the fact that gastroesophageal reflux disease in itself is associated with an increased risk of laryngeal cancer.

Aged↗
PubMed2003

Gastroesophageal reflux as a possible co-promoting factor in the development of the squamous-cell carcinoma of the oral cavity, of the larynx and of the pharynx.

According to recent advances it is assumed that the gastroesophageal reflux (GER) is a possible co-promoting factor of the squamous-cell carcinoma development in the upper parts of the gastro-intestinal and respiratory systems, considering the higher frequency of lesions due to acid in the studied population interested by GER. The aim of this study is to investigate 274 patients with malignant neoplasm of the oral cavity, of the pharynx and of the larynx, by esophago-gastro-duodenoscopy (EGD) and to compare the incidence of GER in this group with a control group of healthy patients from their hospital. Acid exposure in the upper level of the esophagus often remains unknown using traditional pH-monitoring, especially if no pharyngeal probe is used. When necessary a good diagnostic test is EGD with mucosa biopsy; it allows to directly examine the lesion. We retrospectively studied the data of 274 patients suffering from a cancer of the upper aero-digestive tracts by EGD in order to diagnose lesions caused by GER. We compared non-smoking patients affected by GER and tumours a control group of healthy patients. Statistical analysis revealed a significant difference between the two groups using the z-Test (p = 0.0001). In our study, based on endoscopic data, we observed a high percentage of non-smoking patients affected by GER and squamous-cell carcinoma of the upper parts of the airways and the gastrointestinal system. For this reason we consider GER as a possible co-promoting factor of cancer in some patients.

Adult↗
PubMed2001

Structural characterization of complexes between iminodiacetate blocked on styrene-divinylbenzene matrix (Chelex 100 resin) and Fe(III), Cr(III), and Zn(II) in solid phase by energy-dispersive X-ray diffraction.

Local structure of Fe(III), Cr(III), and Zn(II) cations has been determined on the amorphous sample by means of the difference method used for liquid systems. We recorded energy-dispersive X-ray diffraction spectra of a chelating resin (Chelex 100), containing paired iminodiacetate ions coupled to a styrene-divinylbenzene support, in several ionic forms. Coordination geometry of Fe(III), Cr(III), and Zn(II) metal cations with Chelex 100 resin ligand sites, and conformation of the ligand groups have been determined.

Journal Article↗
PubMed2001

An electrochemical multienzymatic biosensor for determination of cholesterol.

This paper describes an electrochemical biosensor for free cholesterol monitoring. The sensor is a multienzymatic electrodic system in which horseradish peroxidase and cholesterol oxidase are simultaneously immobilized within a polymeric film, on the surface of a pyrolitic graphite electrode. From voltammetric and amperometric (flow-injection) data obtained, the efficiency, reproducibility and stability of the system are discussed. Results obtained, of interest for basic and applied biochemistry, represent a first step for construction of a mediator-free biosensor with potentialities for a successful application in the biosensor area.

Biosensing Techniques↗
PubMed2001

Cytochrome c reconstituted from two peptide fragments displays native-like redox properties.

Recombination of two fragments of horse cytochrome c (the heme-containing N-fragment, residues 1-56, and the C-fragment, residues 57-104), which are substantially unstructured at neutral pH, gives rise to a 1:1 fragment complex with a compact conformation, in which the alpha helical structure and the native Met80-Fe(III) axial bond are recovered. With respect to the native protein, the ferric complex shows a less rigid atomic packing and a decreased stability [Delta(DeltaG(o))D = 14.7 kJ.mol(-1)], ascribed to perturbations involving the Trp59 microenvironment and, to a lower extent, the heme pocket region. The redox potential, E1/2 = 234 +/- 5 mV vs. normal hydrogen electrode at 25 degrees C, is close to that of the intact protein, consistent with recovery of the native Met80-heme Fe(III) axial bond. Furthermore, the fragment complex shows reactivity similar to intact cytochrome c, in the reaction with cytochrome c oxidase. We conclude that the absence in the complex of some native cross-links and interlocked packing important for protein rigidity and stability is not as relevant for maintaining the native redox properties of the protein, provided that some structural requirements (i.e. recovering of the native-like alpha helical structure) are fulfilled and coordination of Met80 to the heme-iron is restored.

Animals↗
PubMed2000

Anion size modulates the structure of the A state of cytochrome c.

Several studies have shown that anions induce collapse of acid-denatured cytochrome c into the compact A state having the properties of the molten globule and that the anion charge is the main determinant for the A state stabilization. The results here reported show that the anion size plays a role in determining the overall structure of the A state. In particular, small anions induce formation of an A state in which the native Met80-Fe(III) axial bond is recovered and the nativelike redox properties restored. On the other hand, the A state stabilized by large anions shows a histidine (His26 or His33) as the sixth ligand of the heme-iron, a very weak interaction between Trp59 and the heme propionate, and lacks nativelike redox properties. The two anion-stabilized states show similar stability, indicating that (i) the hydrophobic core (which is equally stabilized by all the anions investigated, independently of their size) is the region that mainly contributes to the macromolecule stabilization, and (ii) the flexible loops are responsible for the spectroscopic (and, thus, structural) and redox differences observed.

Animals↗
PubMed1999

The value of CT scans in improving laryngoscopy in patients with laryngeal cancer.

This retrospective study assessed the value of computed tomography (CT) scan with contrast in improving the staging accuracy of indirect and direct laryngoscopy. We compared the preoperative staging obtained by the two latter procedures with postoperative histopathological findings in 187 patients operated on for laryngeal cancer. Of these cancers, 98 were supraglottic, 82 glottic and 7 subglottic in origin. The staging accuracy of laryngoscopy was 51.3% and CT was 70.1%. When the two procedures were combined, the staging accuracy was 80.2%. The accuracy of the CT increased from glottic to supraglottic to subglottic tumors, although the accuracy of laryngoscopy decreased in the same direction. Laryngoscopy alone tended to understage larger tumors (pT3 and pT4), whereas CT underestimated the smaller ones (pT1 and pT2). Our data suggest that in order to plan the best treatment both laryngoscopy and CT should be used in making the diagnosis.

Adult↗
PubMed1999

The pectoralis major myocutaneous flap in head and neck reconstructive surgery: 16 years of experience.

Wide defects resulting after resection of malignant tumors of the head and neck need an adeguate closure. In the last 16 years, 85 pectoralis major myocutaneous island flap procedures were carried out for the immediate reconstruction of surgical defects following extirpation of malignant tumors at various sites of the upper aerodigestive tract. The final functional and cosmetic results were satisfactory. Partial necrosis was observed in four cases. We did not have any cases of total flap necrosis. Post-operative fistulas were encountered in 14 cases (surgical closure was not necessary). The application and complications of the pectoralis major myocutaneous flap placed at cervical level are reviewed. The aspects of postoperative swallowing function of such surgery are discussed. Reconstruction with the pectoralis major myocutaneous flap is a safe and versatile procedure, yielding good clinical and functional results in patients with advanced head and neck tumors.

Adult↗
PubMed1998

Unmediated heterogeneous electron transfer reaction of ascorbate oxidase and laccase at a gold electrode.

The unmediated electrochemistry of two large Cu-containing proteins, ascorbate oxidase and laccase, was investigated by direct-current cyclic voltammetry. Rapid heterogeneous electron transfer was achieved in the absence of promoters or mediators by trapping a small amount of protein within a solid, electrochemically inert, tributylmethyl phosphonium chloride membrane coating a gold electrode. The problems typical of proteins in solution, such as adsorption on the electrode surface, were avoided by this procedure. In anaerobic conditions, the cyclic voltammograms, run at a scan rate of up to 200 mV/s, showed the electron transfer process to be quasi-reversible and diffusion-controlled. The pH-dependent redox potentials (+360 mV and +400 mV against a normal hydrogen electrode at pH7.0 for ascorbate oxidase and laccase respectively and +390 mV and +410 mV at pH5.5) were similar to those of the free proteins. The same electrochemical behaviour was recorded for the type 2 Cu-depleted derivatives, which contain reduced type 3 Cu, whereas the apoproteins were electrochemically inactive. Under aerobic conditions the catalytic current intensity of holoprotein voltammograms increased up to approx. 2-fold at a low scanning rate, with unchanged redox potentials. The voltammograms of type 2 Cu-depleted proteins and of apoproteins were unaffected by the presence of oxygen. This suggests that electron uptake at the electrode surface involves type 1 Cu and that only in the presence of oxygen is the intramolecular electron transfer to other protein sites rapid enough to be observed. The analogy with available kinetic results is discussed.

Ascorbate Oxidase↗
PubMed1996

Direct electrochemical evidence for an equilibrium intermediate in the guanidine-induced unfolding of cytochrome c.

This paper reports a voltammetric and spectroscopic investigation of the guanidine-induced unfolding of cytochrome c at neutral pH and 25 degrees C. Electrochemical data provide direct evidence for the presence of an equilibrium intermediate (form I) strictly dependent on the denaturant concentration. The midpoint potential of form I has been determined (E1/2 = +0.010 V vs. NHE) and its structural features defined from analysis of the circular dichroism and absorbance spectroscopy data obtained under the same experimental conditions. From the correlation of electrochemical and spectroscopic data, we propose that the features detected by the intermediate conform to the molten globule state.

Animals↗
PubMed1996

Influence of glycerol on the structure and redox properties of horse heart cytochrome c. A circular dichroism and electrochemical study.

The effect of glycerol on the structure and redox properties of horse heart cytochrome c was investigated by absorption spectroscopy, circular dichroism, and dc cyclic voltammetry techniques. The results show that the organic solvent increases the alpha-helix structure of the protein and induces slight changes at the active-site environment: however, the overall tertiary structure does not appear to be significantly perturbed. Glycerol stabilizes cytochrome c, the free energy of denaturation (delta G0) being approximately 0.7 kcal/mol larger than that determined in phosphate buffer under the same conditions, and influences the heterogeneous electron transfer kinetics at a chemically modified gold electrode: on the other hand, the redox potential of the protein is unaltered. On the whole, the results obtained indicate that glycerol acts as a suitable stabilizing agent of cytochrome c, which is of interest for application in biotechnology: the organic solvent does not alter the tertiary structure significantly or the redox properties of the protein. This has to be interpreted not only in terms of the glycerol-induced solvent ordering around the protein surface, but also as due to the specific features of the protein matrix.

Animals↗
PubMed1996

Vallate, foliate and fungiform human papillae gustatory cells. An immunocytochemical and ultrastructural study.

We studied the classifications, topographic distribution and cellular lines of taste bud components in vallate, foliate and fungiform papillae of young, mature and old men with light microscopy, SEM, and TEM. By identifying ultrastructural and immunocytochemical characteristics, three distinct sensorial cells were identified, along with a few basal cells: dark type I cells, light type II cells and light type III cells. These cells extend from the epithelial basal lamina to the gustatory canal, where their apical cytoplasm sends long microvillous expansions. Excluding those of the fungiform papillae-which never go beyond the lower third of the gustatory canal, and are always void of dense substance-the microvillous expansions continue to the external border of the taste pore. Dark type I cells are rich in free ribosomes, tubular RER and large dense granules. Light type II cells with scarce ribosomes and RER, do not have enough peculiar ultrastructural characteristics to be considered effector or phagocyte elements. Light type III cells are characterizes by dense core vesicles whose peculiar ultrastructural characteristics in the foliate and vallate papillae, should be considered a consequence of different functional phases. After comparative evaluation the authors hypothesized on the functional value of some ultrastructural aspects and on the dense core vesicles which are immunoreactive to 5-HT. They observed that all gustatory cells are involved in taste transduction based on behaviours caused by microvilli in the gustatory canal and gustatory cell relationships with nerve endings. Moreover the authors noted that age does not seem to influence taste perception.

Adult↗
PubMed1996

[Panendoscopy in the research of multiple malignant synchronous occult tumors in patients with cancer of the upper aero-digestive tract].

The Authors consider the result obtained in the diagnosis of malignancies simultaneous neoplasia in patients with a tumour of the head and neck. The study was conducted on 337 patients on 750 observed in the last seven years with a squamous-cell carcinoma at different stages of keratinization, who underwent an ORL examination, bronchoscopy and esophagogastroduodenoscopy, sometimes with intravital staining. Bronchoscopy was conducted on 297 patients, esophagogastruoduodenoscopy on 300. Altogether 260 were subject to both techniques and 77 to only one procedure. Endoscopy released a second tumour in 4 cases on 297 (1.34%) of the bronchus and in 5 cases on 300 (1.66%) of the esophagus. The percentage amounts to 3.46% in 260 patients subject to both examinations. Our study released a malignancies cells (18 cases on 216); this number was not confirmed by istological examination on bronchial biopsy. Our collaborators consider this result as pollution derived from cells coming from clear tumour in expansion. Our study, obtained from a substantial number of cases, justify the use of panendoscopy screening in conjunction with routine studies; although this procedure is aggressive, it is acceptable, because these second tumours have been discovered in early and asintomatic stage and were not found in the radiological examination.

Adult↗
PubMed1991

Vital staining of oesophagus in patients with head and neck cancer: still a worthwhile procedure.

One hundred three patients with upper aerodigestive cancer were consecutively submitted to upper GI endoscopy with vital staining (Toluidine Blue 1%) of the oesophagus. The aim of the study was not only to confirm the prevalence of synchronous or metachronous tumour but also to verify the usefulness of the vital stain compared to simple endoscopy. Staining was positive in 29 patients (28.1%) for oesophagitis, leukoplakia, Barrett's oesophagus and 3 oesophageal neoplasms (2.9%), two of them unsuspected at endoscopy. We did not observe false positives while 13 cases (13/29-44.8%) were considered normal at endoscopy. Five cases with some endoscopic abnormality of the mucosa did not stain and were considered false negatives. Specificity of the method was 100%, sensibility 85.2%. The recognition of dysplastic changes and neoplasms not suspected at endoscopy should recommend in our opinion the use of vital staining of oesophagus in high-risk groups.

Adult↗
PubMed1990

[Granular cell tumor of the larynx: apropos of a case].

Granular cell tumor of the larynx is a rare benign lesion. The Authors present a literature survey and report a case observed in the E.N.T. Institute of Parma University. The patient was a 22 year-old woman, smoker, whose right vocal cord was affected. Hoarseness represented the only symptom. The tumor was removed by the microsurgical method and histologically examined.

Adult↗