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Biomedical subjects

A Pastore

Publications and source records attributed to A Pastore.

At least 37 records · Page 2Linked to original sources

Glutathione in blood of patients with Friedreich's ataxia.

BACKGROUND: Oxidative stress and mitochondrial dysfunction have long been considered to play a role in Friedreich's ataxia, a neurodegenerative disease due to a GAA expansion in a gene coding for a mitochondrial protein (frataxin), implicated in the regulation of iron metabolism. Since glutathione is an important antioxidant whose role has been recently proposed in the pathogenesis of some neurodegenerative diseases, we investigated glutathione metabolism in the blood of 14 patients with Friedreich's ataxia by measuring total, free and protein-bound glutathione concentrations. MATERIALS AND METHODS: Blood samples were obtained from 14 unrelated patients with Friedreich's ataxia (nine males, five females) and 20 age-matched healthy controls (10 males, 10 females). Total and free glutathione concentrations were determined by reverse-phase liquid chromatography with fluorescence detection; the glutathionyl-haemoglobin separation from healthy and pathological subjects was obtained by electrospray ionization-mass spectrometry. RESULTS: We consistently found a reduction of free glutathione levels (0.55 +/- 0.06 nmol mg(-1) haemoglobin, vs. 8.4 +/- 1.79 nmol mg(-1) haemoglobin, P < 0.001) in the blood of patients with Friedreich's ataxia, a total glutathione concentration comparable to the controls (15 +/- 2.6 nmol mg(-1) haemoglobin, vs. 15.4 +/- 1.4 nmol mg(-1) haemoglobin), and a significant increase of glutathione bound to haemoglobin (15 +/- 1.5 vs. 8 +/- 1.8%, P < 0.05) in erythrocytes. CONCLUSIONS: Our findings give evidence of an impairment in vivo of glutathione homeostasis in Friedreich's ataxia, suggesting a relevant role of free radical cytotoxicity in the pathophysiology of the disease; this study may also prove useful in the search for an oxidative stress marker in neurodegeneration.

Adolescent↗

Comparison between TANIS and UICC 1997 stage grouping in parotid gland carcinoma.

To compare the correlation of T and N Integer Score (TANIS) and International Union Against Cancer (UICC) '97 stage grouping with survival rate in parotid gland carcinoma, a series of 134 patients affected by primary carcinoma of the parotid gland was considered in this retrospective study. Data set was classified according to 1997 UICC T-category and then grouped as recommended by the two systems. Data were analyzed by means of survival analyses (Kaplan-Meier and Cox algorithms). Results showed a crude survival rate of 64.9%. Univariate analysis by means of log-rank test yielded significant P values both for TANIS and UICC '97 systems (both P < 0.0001). Multivariate analysis (Cox regression adjusted for age and gender) showed a significant correlation between the two staging systems with the mortality rate. Odds ratios were 2.64 (95% CI 1.84-3.80) and 1.79 (95% CI 1.46-2.20) for UICC '97 and TANIS, respectively. In testing the superiority, UICC '97 resulted in a higher prognostic value and TANIS did not add any statistical contribution in determining survival. In conclusion, the new UICC stage grouping better defines the prognosis for cancer of the parotid gland.

Adolescent↗

Hibernoma of the neck.

A hibernoma is a rare, benign, soft-tissue tumor composed of cells similar to those of brown adipose tissue. Only nine cases in the cervical area have been reported. Typically, hibernomas are asymptomatic and slow growing. Adequate treatment consists of complete excision. We describe an additional case of neck hibernoma and review the literature to clarify a pathologic condition rarely included in the differential diagnosis of cervical masses.

Adult↗

Parotid gland carcinoma: surgical strategy based on local risk factors.

To evaluate the best surgical strategy in cases of parotid gland carcinoma, local risk factors (T, N, histology, and treatment) were analyzed in a series of 134 patients. The efficacy of the facial nerve sacrifice in case of macroscopic tumor infiltration was tested by means of survival analyses (Kaplan-Meier and Cox algorithms). This study demonstrated that nerve preservation resulted in a better prognostic value when compared with resection only in the group of patients having a T1 or T2. In patients affected by T3 and T4, the different treatment did not show any difference in survival rate. In conclusion, the sacrifice of the facial nerve is not always able to improve the survival rate.

Adolescent↗

Unresectable primary tumor of head and neck: does neck dissection combined with chemoradiotherapy improve survival?

A study regarding patients with primary and previously untreated advanced histologically proven squamous cell carcinoma of the head and neck was performed to compare two treatment modalities: neck dissection followed by chemoradiotherapy (Group I) versus chemoradiotherapy alone (Group II). Fifty-four patients were randomly chosen to receive Group I or II treatment. Our results demonstrate that Group I treatment has a higher and statistically significant disease-specific survival rate. We suggest that an association of neck dissection plus chemoradiotherapy can be useful in the event of unresectable advanced carcinomas.

Adult↗

Supraglottic tumour categories: 1987 and 1997 International Union Against Cancer classification.

PURPOSE: To verify the correlation to survival of 1987 and 1997 Union Internationale Contre le Cancer (UICC; International Union Against Cancer) supraglottic tumour categories. MATERIALS AND METHODS: Two hundred and sixty patients seen at the ENT Clinic at the University of Ferrara from 1970 to 1990 had a complete follow-up and met the criteria of enrolment in this study. Data were analyzed by means of survival analyses (Kaplan-Meier and Cox algorithms). RESULTS: Multivariate analysis (adjusted for number and patient's age) of 1997 UICC supraglottic tumour categories (T1 vs. T4) showed a significant correlation with the survival rate, whereas 1987 UICC categories did not reach any significant statistical value. CONCLUSION: The 1997 UICC tumour categories represent an improvement in supraglottic cancer classification.

Carcinoma, Squamous Cell↗

[Rhinoscleroma with extramaxillary extension: report of a clinical case].

Rhinoscleroma is a chronic, granulomatous infection most frequently affecting the respiratory tract mucosa. The disease is endemic in some geographic areas and is sporadic in Italy, where medio-facial granulomatoses must be differentiated from malignant naso-sinus neoplasms. The present work describes a case of rhino-sinus scleroma with extramaxillary extension, defining the most important clinical characteristics and the treatment performed.

Aged↗

[Eutectic mixture of local anesthetics (EMLA): evaluation of the analgesic effectiveness during ND: YAG laser turbinoplasty].

The analgesic effect of EMLA anesthetic cream is evaluated during contact turbinoplasty with a Neodymium: yttrium-aluminum-garnet (Nd: Yag) laser. A total of 48 patients were selected and randomized in two groups. EMLA was applied on the nasal mucosa, respectively, for 15 and 30 minutes after using vasoconstrictor cottonoids. Both groups underwent turbinate reduction by contact with Nd: Yag laser using three discharge incisions traced parallel on the medial surface of the lower turbinate working from the tail to the head. The pain induced by the surgical procedure was evaluated with a visual analogic scale. The score obtained was significantly lower in the 1st group than in the 2nd group and this difference was statistically significant (p < 0.01). The EMLA anesthetic cream applied on the mucosa for 15 minutes allows to obtain a good analgesia during the functional contact turbinate surgery with a Nd: Yag laser and thus can be considered a valid alternative to anesthesia by local infiltration.

Administration, Topical↗

[Malignant fibrous histiocytoma of the larynx. Presentation of a clinical case and review of the literature].

Malignant Fibrous Histiocytoma (MFH) is a tumor of mesenchymal origin which rarely occurs in head and neck. At the laryngeal level this neoplasm manifests itself as a sessile or peduncolate mass with ulcerations. Histological diagnosis of small biopsy samples is difficult and is, therefore, performed on the full surgical piece. The treatment of choice is complete exeresis of the mass within a safety margins. The Authors present a case report, the 37th laryngeal MFH reported in the literature and, in particular, the 5th case presented in a supraglottic site. Surgical treatment performed in this patient was exeresis of the neoplasm through pharyngothyrotomy conduced with safety margins and reconstruction by thyrohyoidpexy.

Adult↗

Towards a structural understanding of Friedreich's ataxia: the solution structure of frataxin.

BACKGROUND: Lesions in the gene for frataxin, a nuclear-encoded mitochondrial protein, cause the recessively inherited condition Friedreich's ataxia. It is thought that the condition arises from disregulation of mitochondrial iron homeostasis, with concomitant oxidative damage leading to neuronal death. Very little is, as yet, known about the biochemical function of frataxin. RESULTS: Here, we show that the mature form of recombinant frataxin behaves in solution as a monodisperse species that is composed of a 15-residue-long unstructured N terminus and an evolutionarily conserved C-terminal region that is able to fold independently. The structure of the C-terminal domain consists of a stable seven-stranded antiparallel beta sheet packing against a pair of parallel helices. The structure is compact with neither grooves nor cavities, features that are typical of iron-binding modules. Exposed evolutionarily conserved residues cover a broad area and all cluster on the beta-sheet face of the structure, suggesting that this is a functionally important surface. The effect of two clinically occurring mutations on the fold was checked experimentally. When the mature protein was titrated with iron, no tendency to iron-binding or to aggregation was observed. CONCLUSIONS: Knowledge of the frataxin structure provides important guidelines as to the nature of the frataxin binding partner. The absence of all the features expected for an iron-binding activity, the large conserved area on its surface and lack of evidence for iron-binding activity strongly support an indirect involvement of frataxin in iron metabolism. The effects of point mutations associated with Friedreich's ataxia can be rationalised by knowledge of the structure and suggest possible models for the occurrence of the disease in compound heterozygous patients.

Amino Acid Sequence↗

Binding of alpha-actinin to titin: implications for Z-disk assembly.

Titin is an exceptionally large protein (M.Wt. approximately 3 MDa) that spans half the sarcomere in muscle, from the Z-disk to the M-line. In the Z-disk, it interacts with alpha-actinin homodimers that are a principal component of the Z-filaments linking actin filaments. The interaction between titin and alpha-actinin involves repeating approximately 45 amino acid sequences (Z-repeats) near the N-terminus of titin and the C-lobe of the C-terminal calmodulin-like domain of alpha-actinin. The conformation of Z-repeat 7 (ZR7) of titin when complexed with the 73-amino acid C-terminal portion of alpha-actinin (EF34) was studied by heteronuclear NMR spectroscopy using (15)N-labeling of ZR7 and found to be helical over a stretch of 18 residues. Complex formation resulted in the protection of one site of preferential cleavage of EF34 at Phe14-Leu17, as determined by limited proteolysis experiments coupled to mass spectrometry measurements. Intermolecular NOEs show Val16 of ZR7 to be positioned close in space to the backbone of EF34 around Phe14. These observations suggest that the mode of binding of ZR7 to EF34 is similar to that of troponin I to troponin C and of peptide C20W to calmodulin. These complexes would appear to represent a general alternative binding mode of calmodulin-like domains to target peptides.

Actinin↗

Laryngopyocele: three new clinical cases and review of the literature.

Laryngopyocele is a fairly rare disease. It is a complication of laryngocele. Its clinical picture is often alarming; thus it needs fast differential diagnosis. Computed tomography allows early diagnosis. Surgical treatment permits a complete recovery. An association between laryngocele and carcinoma of the larynx has been reported by some authors. Three new cases of laryngopyocele are presented and discussed.

Abscess↗

Lack of association between carotid intima-media thickness and methylenetetrahydrofolate reductase gene polymorphism or serum homocysteine in non-insulin-dependent diabetes mellitus.

We assessed the contribution of the serum homocysteine (Hcy) level, an independent risk factor for vascular disease, and methylene tetrahydrofolate reductase (MTHFR) gene polymorphism to the variability of intimal-medial thickness (IMT) of the common carotid artery in middle-aged non-insulin-dependent diabetes mellitus (NIDDM) subjects. One hundred thirty NIDDM patients (60 males and 70 females) with a mean age of 53 +/- 10 years and a mean diabetes duration of 11.3 +/- 7.9 years were enrolled for the study. Exclusion criteria included liver, heart, kidney, or other major-organ disease. Fasting total serum Hcy, folate, and vitamin B12 and clinical chemistry analyte levels were measured. MTHFR polymorphism was determined by polymerase chain reaction (PCR). IMT and plaques or stenosis in the common carotid were measured by ultrasonography. Serum Hcy was inversely correlated with vitamin levels and was slightly higher in subjects with the Val/Val genotype versus Ala/Val and Ala/Ala (P = .02); no differences in genotype were found in subjects with folate or vitamin B12 at or above the median level. In univariate analysis, common carotid IMT was significantly associated with age (P = .00001), the body mass index ([BMI] P = .0003), uric acid (P = .004), systolic blood pressure (P = .03), glycemia (P = .03), and total cholesterol (P = .04). No significant association was found between serum Hcy or MTHFR polymorphism and IMT. In multiple regression analysis, age (P = .0001), uric acid (P = .03), glycemia, and the BMI (P = .05) were independently associated with IMT and explained about 42% of IMT variability. In 130 NIDDM patients without nephropathy, basal levels of serum Hcy, as well as MTHFR polymorphism, did not predict significant changes in common carotid IMT.

Arteriosclerosis↗

Schwannoma of the parapharyngeal space.

A schwannoma (or neurilemmoma) of the parapharyngeal space is a rare tumor in the head and neck region arising from the sheath of cranial nerves and/or the sympathetic chain. In the early stages of growth, there is usually a lack of symptoms because of the anatomical localization and slow growth of the tumor. The large dimension of the mass at presentation makes it difficult to perform a functional surgery, and in many cases the operation worsens the nerve status. The choice of surgical approach is of paramount importance in both preserving nerve function and achieving vascular control. The authors report a case and discuss the English literature.

Aged↗

Purification, biochemical, and immunological characterisation of a major food allergen: different immunoglobulin E recognition of the apo- and calcium-bound forms of carp parvalbumin.

BACKGROUND: Almost 4% of the population suffer from food allergy which is an adverse reaction to food with an underlying immunological mechanism. AIMS: To characterise one of the most frequent IgE defined food allergens, fish parvalbumin. METHODS: Tissue and subcellular distribution of carp parvalbumin was analysed by immunogold electron microscopy and cell fractionation. Parvalbumin was purified to homogeneity, analysed by mass spectrometry and circular dichroism (CD) spectroscopy, and its allergenic activity was analysed by IgE binding and basophil histamine release tests. RESULTS: The isoelectric point (pI) 4.7 form of carp parvalbumin, a three EF-hand calcium-binding protein, was purified to homogeneity. CD analysis revealed a remarkable stability and refolding capacity of calcium-bound parvalbumin. This may explain why parvalbumin, despite cooking and exposure to the gastrointestinal tract, can sensitise patients. Purified parvalbumin reacted with IgE of more than 95% of individuals allergic to fish, induced dose-dependent basophil histamine release and contained, on average, 83% of the IgE epitopes present in other fish species. Calcium depletion reduced the IgE binding capacity of parvalbumin which, according to CD analysis, may be due to conformation-dependent IgE recognition. CONCLUSIONS: Purified carp parvalbumin represents an important cross reactive food allergen. It can be used for in vitro and in vivo diagnosis of fish-induced food allergy. Our finding that the apo-form of parvalbumin had a greatly reduced IgE binding capacity indicates that this form may be a candidate for safe immunotherapy of fish-related food allergy.

Allergens↗