Biomedical subjects

A Vitali

Publications and source records attributed to A Vitali.

At least 19 recordsLinked to original sources

PubMed2006

Purification and characterization of an antifungal thaumatin-like protein from Cassia didymobotrya cell culture.

A 23-kDa antifungal thaumatin-like protein was isolated and purified from Cassia didymobotrya (Fres.) cell cultures for the first time. The protein was secreted in the culture medium, but it could be also isolated after elution of whole cells with a 0.5 M CaCl(2) solution. Treatment of the cells with laminarin oligosaccharides or salicylic acid, but not with NaCl, resulted in enhancement of expression of the protein. A rapid purification protocol was used based on cationic exchange chromatography. The protein, with a highly basic character (pI 10), has an exact molecular mass of 23034 Da, as determined by MALDI-ToF mass spectrometry analysis. N-terminal sequencing of the intact polypeptide and the sequencing of two internal tryptic peptides indicated significant identity with other thaumatin-like proteins (TLP). The protein exerted antifungal activity towards some Candida species showing EC(50) values comparable to those of other antifungal TLPs. The collected data lead to classify this TLP as a new PR-5 protein.

Amino Acid Sequence↗

PubMed2006

Preclinical analysis of the analinoquinazoline AG1478, a specific small molecule inhibitor of EGF receptor tyrosine kinase.

The tyrphostin 4-(3-chloroanilino)-6,7-dimethoxyquinazoline (AG1478) is a potent and specific inhibitor of EGFR tyrosine kinase whose favourable preclinical profile supports progression towards clinical trials. Microphysiometric evaluation revealed a short (<24 min) effective inhibition of cellular receptor response to EGF challenge in BaF/ERX cells indicating a need to maintain sustained levels of inhibitor. Initial pharmacokinetic evaluation in mice of novel AG1478 formulations in a beta-cyclodextrin (Captisol) showed monoexponential elimination from plasma (half-life 30 min) following subcutaneous administration. A two-fold dose escalation gave a 2.4-fold increase in the total AUC. Bolus i.v. and 6 h continuous infusion were investigated in rats to mimic a more clinically relevant administration regimen. Drug elimination following bolus i.v. administration was biphasic (terminal elimination half-life 30-48 min). The linear relationship between dose and AUC(0-->infinity) (r2=0.979) enabled the prediction of infusion rates and doses for sustained delivery using continuous 6 h infusions, where steady state was reached in 120 min. Plasma levels of AG1478>10 microM were achieved over the duration of the infusion. At the lowest dose, plasma drug levels after the cessation of infusion declined with a half-life of approximately 43 min. EGFR activity, measured both by autophosphorylation and downstream signalling, was inhibited in a dose-dependent manner by injection of AG1478 in mice bearing xenografts of the human glioblastoma cell line U87MG.delta2-7, which expresses a constitutively active variant of the EGF receptor. Taken together, these experiments provide essential data to assess the anti-tumour efficacy of AG1478 and will assist in the rational design of dose regimens for clinical studies.

Animals↗

PubMed2005

Two proline-rich peptides from pig (Sus scrofa) salivary glands generated by pre-secretory pathway underlying the action of a proteinase cleaving ProAla bonds.

The primary structures of two salivary proline-rich peptides (PRP-SP-A, M 6156.0 amu and PRP-SP-B, M 1905.0 amu), from pig (Sus scrofa) were determined. The PRP-SP-B peptide, 21 residues long, overlaps with a sequence repeated 43 times in three deposited cDNAs coding for PRP proteins cloned from porcine parotid glands (Swiss-Prot codes: Q95JC9, Q95JD1, Q95JD0). PRP-SP-A peptide, 56 amino acid residues long, overlaps with the N-terminus repeats of Q95JC9 and Q95JD1 and it is phosphorylated at Ser 12 and 14. The two peptides were found both in whole saliva and in granules from pig parotid glands. The biosynthesis of the two peptides implies the action of a proteinase responsible for Pro downward arrow Ala cleavage in the pre-secretory process.

Alanine↗

PubMed2005

A novel presenilin 1 L166H mutation in a pseudo-sporadic case of early-onset Alzheimer's disease.

We report a 44-year-old woman presenting at 33 years with memory loss, followed by progressive dementia. Her family history was negative for dominant genetic disorders at high penetrance. Analysis of presenilin-1 gene revealed a missense mutation at codon 166, leading to the substitution from leucine to histidine. The mutation occurs in the third transmembrane domain of presenilin-1, at the position of two different mutations previously described, associated with an atypical phenotype. The present case has two implications: (1) mutations of presenilin-1 have to be searched also in apparently sporadic cases of dementia beginning in the third decade of life; (2) as yet unidentified factors, besides the gamma-secretase complex, influence the phenotype of presenilin-1 mutations.

Adult↗

PubMed2005

Statherin levels in saliva of patients with precancerous and cancerous lesions of the oral cavity: a preliminary report.

OBJECTIVE: The aim of this study was to measure concentration of human salivary statherin in patients with oral cavity pathologies and salivary gland diseases. SUBJECTS AND METHODS: Levels of statherin were analysed with High Performance Liquid Chromatography (HPLC) in following groups of subjects: group A: 24 patients with neoplastic diseases of salivary glands, group B: 13 patients with inflammatory lesions of salivary glands, group C: 13 patients with precancerous and cancerous lesions of the oral cavity excluding salivary gland tumors, group D: 20 healthy volunteers (control group). RESULTS: Our preliminary data indicated a sensible reduction of the statherin level in the saliva of patients with precancerous and cancerous lesions of the oral cavity (group C) compared with the healthy subjects (group D). The statherin levels are not significantly reduced either in the inflammatory (group B) or in the salivary glands tumours (group A), compared with the healthy subjects (group D). CONCLUSION: Statherin could play a protective effect in oral cavity in association with its other functions.

Adolescent↗

PubMed2004

Plasma levels of amyloid beta-protein 42 are increased in women with mild cognitive impairment.

BACKGROUND: Accumulation in the brain of small aggregates of amyloid beta-protein 42 (Abeta42) is the major pathogenic event of Alzheimer disease (AD). In familial early-onset AD this event is likely the result of Abeta42 overproduction; in the most common sporadic late-onset form of the disease the mechanisms of Abeta42 accumulation are unknown. METHODS: To address this issue the authors analyzed plasma levels of Abeta42 in 88 elderly patients with amnestic mild cognitive impairment (MCI), chosen as paradigm of preclinical sporadic AD. RESULTS: The authors found a significant increase of Abeta42 plasma levels in women with MCI, in comparison to the affected men and 72 cognitively normal age-matched subjects. The levels were independent of variables in education, apolipoprotein E genotype, cholesterol, and creatinine plasma concentrations, as well as hemoglobin content. CONCLUSIONS: The elevation of Abeta42 plasma levels in women with MCI may represent a biologic explanation for the sex-dependent increased incidence of late-onset AD in women identified by epidemiologic studies.

Age of Onset↗

PubMed2004

Bilateral carcinoma in situ of the testis and cystic fibrosis transmembrane conductance regulator (CFTR) mutation in an azoospermic patient with late-onset 21beta-hydroxylase deficiency.

Testicular cancer can impair spermatogenesis. In addition, chemotherapy or radiotherapy used for its treatment further damage testicular function mainly affecting highly proliferating germ cells. The multifaceted etiology of male infertility includes, among others, alterations of male reproductive tract differentiation such as monolateral or bilateral congenital absence of vas deferens and perturbations in adrenal steroid synthesis on a genetic basis such as 21beta-hydroxylase deficiency. Herein, we report the case of a male patient with primary infertility, probably related to a combination of genetic and acquired factors with different expressions over time.

17-alpha-Hydroxyprogesterone↗

PubMed2003

Intestinal localization of anisakiasis manifested as acute abdomen.

Anisakis pathology is due mainly to two mechanisms: allergic reactions (from isolated urticaria and angioedema to life-threatening anaphylactic shock associated with gastrointestinal symptoms or 'gastroallergic anisakiasis'), and direct tissue damage, due to invasion of the gut wall, development of eosinophilic granuloma, or perforation (gastric or intestinal anisakiasis). Anisakiasis is a misdiagnosed and underestimated cause of acute abdomen: most patients undergo laparotomy, and virtually no cases are diagnosed before surgery. In some cases, diagnosis is obtained accidentally during other pathologic investigations. We report a case of acute abdomen due to terminal ileum involvement. Microscopic examination of the resected segment showed the presence of helminthic sections consistent with larvae of Anisakis spp. A history of raw fish ingestion was recorded. Histopathologic features are illustrated. A short but up-to-date review of the literature on diagnostic devices (particularly imaging and serology), clinical aspects and therapy is presented.

Abdomen, Acute↗

PubMed2003

Determination of the post-translational modifications of salivary acidic proline-rich proteins.

Human salivary acidic proline-rich proteins were analyzed by electrospray-ion trap mass spectrometry and by matrix-assisted laser desorption/ionization-time of flight mass spectrometry. All acidic-PRP isoforms share a common N-terminal region, which contains a pyroglutamic acid residue at the N-terminus, and two phosphorylation sites on Ser 8 and 22. At the same time, HPLC-MS spectra revealed isoforms of PRP-1 and PRP-3 having a different number of phosphoserine residues, namely, a mono-phosphorylated form of PRP-1 and PRP-3 and a tri-phosphorylated form of PRP-1. The analysis of the masses of tryptic digests suggested that the third phosphate residue should be located on Ser 17. Another protein with a mass of 30,923 amu was detected along the HPLC pattern and MS data of its tryptic digest suggested that it corresponds to the dimer of Pa, the isoform of PRP-1 with a substitution Arg-Cys at 103 position. Finally, structural identification is pending for another post-translational modification of acidic-PRP that provides an increase of 111-114 amu.

Amino Acid Sequence↗

PubMed2003

[Verapamil in the cardioversion of atrial fibrillation. Clinical study].

BACKGROUND: Prolonged periods of atrial fibrillation (AF) or high frequency atrial pacing lead to a significant shortening of atrial refractory periods. This time-dependent electric remodelling is reduced significantly by the administration of verapamil. METHODS: The present series consists of 24 patients all suffering from atrial fibrillation (33% acute AF and 66% chronic recurrent AF) admitted to our Cardiology Department (Rome University). Group G1 (13 patients) received i.v. verapamil (50 mg in 500 cc saline solution at 40 ml/hr). Group G2 (11 patients) received amiodarone i.v. (300 mg in bolus form followed by the infusion of 900 mg in 500 cc 5% glucosate solution, 33 ml/hr for 6 hours and subsequently 18 ml/hr). All patients received non-fractionated heparin i.v. at the same time. RESULTS: No statistically significant difference was observed in the percentage of pharmacological cardioversions in the two groups: G1=61% vs G2=54% p=0.94). The patients who were not cardioverted pharmacologically were done so electrically (external DC shock). CONCLUSIONS: Albeit in this small population of patients verapamil proved to possess anti-arrhythmic effects on a par with that of standard amiodarone antiarrhythmic treatment. This antiarrhythmic potential of verapamil should be demonstrated in a broader randomised study.

Aged↗

PubMed2003

Tanycytic ependymoma of the spinal cord. Case report and review of the literature.

OBJECTIVE AND IMPORTANCE: We report a rare case of the tanycytic variant of intramedullary ependymoma. Tanycytes are the common progenitor cells of both ependymal cells and astrocytes. These particular elongate unipolar and bipolar ependymal cells extend from the ventricular lumen to the surface of the nervous system. It is extremely important, in terms of both management and prognosis, to distinguish intramedullary tanycytic ependymomas from intramedullary astrocytomas although a correct histological diagnosis may be difficult since tanycytes resemble astrocytes. CASE REPORT: A 39-year-old woman underwent surgical treatment for a cervical intramedullary tumor in our department. Although pathological examination of frozen sections was suggestive of low-grade astrocytoma, the definitive histological diagnosis was "tanycytic" ependymoma, a tumor characterized by poor cellularity, elongated elements mixed with fibrillary components, rare pseudo-rosettes and mixed astro-ependymal aspects. Since a complete resection was performed at surgery, no further treatment was proposed. After a follow-up period of two years the patient is free from recurrence. CONCLUSION: Tanycytic ependymomas should be managed in the same way as "ordinary" ependymomas, since there is no current evidence suggesting that these morphologically distinct tumors differ in terms of biological behavior. Increased awareness of this transitional form of intramedullary ependymoma among neurosurgeons and pathologists may avoid incorrect surgical approaches and postoperative treatment.

Adult↗

PubMed2002

Papnet-assisted cytological diagnosis intensifies the already marked variability among cytological laboratories.

OBJECTIVE: The main objective was to assess the sensitivity, specificity and reliability of PAPNET-assisted diagnosis in comparison with conventional screening. SETTING: Seven Italian and one English University or Research Institutes, and a random sample of an other 20 Italian Laboratories of the Italian National Health Service (INHS) provided the cervical smears. METHODS: During the training phase every center examined in rotation four sets of slides for a total of 300 representative slides. Afterwards, 900 "positive" slides were added to the 3,100 slides which were collected consecutively without any selection or exclusion. The eight main centers were divided into four couples and each couple of centers examined 775 slides with the PAPNET system, "blindly" to the original diagnosis. An expert cytopathologist (M.A.) of the National Institute of Health (NIH) reassessed 40% of the slides with an original negative diagnosis to evaluate the false negative rate. Two expert NIH cytopathologists (M.A., G.M.) re-examined all slides where a disagreement had been observed between the original and one or both of the study diagnoses. The main analyses concerned the following three main categories: WNL and unsatisfactory for evaluation; ASCUS, AGUS and LSIL; HSIL and carcinoma. A special algorithm was devised to define the reference diagnosis for sensitivity and specificity assessment. RESULTS: Laboratories, even belonging to the same couple, classified as "no review" a very different proportion of slides ranging from 35% to 74%. The index of kappa agreement between the members of couples examining the same sets of slides was low or very low, ranging from 0.30 to 0.03. The sensitivity of the review classification was particularly low in some laboratories. Surprisingly, only a small correlation was observed between the sensitivity of the review classification and the proportion of slides classified as "review". The "tentative" diagnosis on PAPNET tiles of the "review" slides was almost as reliable as the microscopic diagnosis. In the overall performance, there were many significant differences among the eight laboratories. The best laboratory had a sensitivity of 95% and a specificity of 96%. At least three laboratories displayed unacceptably low sensitivity and one a very low specificity. CONCLUSION: Altogether these results seem to confirm that there are wide differences among cytological laboratories per se, and that these differences are intensified by the use of an instrument like PAPNET. The huge variation in performance may be explained by differences in basic skills and by different training, but it is difficult to understand exactly what could have been done to reduce it.

Autoanalysis↗

PubMed2001

Synthesis and biosynthesis of isocordoin.

In the search of a convenient synthesis for isocordoin (1), a potential anticancer natural product, 2',4'-dihydroxychalcone was inoculated in cell suspension cultures of Morus nigra, which were expected to contain an active prenyltransferase. After 24 hours the target compound was easily isolated from the metabolite extract. Optimization of the biotransformation resulted in a 85% yield of the prenyl derivative.

Acetophenones↗

PubMed2001

Examining structured representation and designated fiscal support for women's health in the U.S. Department of Health and Human Resources.

The United States Department of Health and Human Services (DHHS) is committed to monitoring, protecting, and improving the health of the nation. We examine the structure established within DHHS to address the health of women; review initiatives generated by women's health offices, advisors, and coordinators within DHHS agencies; and contrast the budgets provided to women's health offices with those of the parent DHHS agencies. Data were obtained from DHHS and other public government documents, DHHS websites, contact with agency personnel, and literature review. Significant clinical, research, and educational efforts important to the health of women have resulted from representation for women's health within the DHHS. Yet, structured representation and designated fiscal support necessary to maintain and expand these efforts are variable and not guaranteed across agencies. Only one Office of Women's Health and one Senior Advisor position are supported by statute, one director's position for an Office of Women's Health has been downgraded in government rank, and two other women's health positions had their reporting structure changed, making them less centrally located in their respective agencies. During the last 4 years of unprecedented growth within DHHS, only one Office of Women's Health received consistent increases in budgeted dollars. There is a clear need to support and stabilize representation for women's health within DHHS in order to maintain current productive efforts, coordinate existing and developing initiatives, and integrate new topics of importance to women's health into each agency. This can be accomplished by establishing structured offices by statute and ensuring future funding commensurate with the mission of each office.

Administrative Personnel↗

PubMed2001

Aryltetralin lignans: chemistry, pharmacology and biotransformations.

Podophyllotoxin derivatives like etoposide 7a, etophos 7b, and teniposide 7c are used clinically as potent chemotherapeutic agents for a variety of tumors including small cell lung carcinoma, testicular cancer, and malignant lymphoma. These compounds derived from a series of modifications which converted podophyllotoxin 1a from an entity that interacted with tubulin and blocks mitosis to one that induced a block in late S or early G2 by interacting with topoisomerase II. Synthetic studies on podophyllotoxin derivatives can be divided in four general approaches (the oxo-ester route, the digydroxy acid route, the tandem conjugate addition route and the Diels-Alder route). Albeit a number of synthetic sequences afforded products with excellent enantiopurities, the low overall yields still disqualify synthesis as an alternative for naturally produced materials. An alternative route based on the enzyme-catalyzed cyclization of synthetic intermediates to analogues of the podophyllotoxin family is being explored. Synthetic dibenzylbutanolides, which were revealed by biosynthetic studies to be the precursors of aryltetralin lignans, have been treated with enzymes derived from cell cultures of Podophyllum peltatum, Catharanthus roseus, Nicotiana sylvestris and Cassia didymobotrya. The ciclyzation process afforded however compounds with a different stereochemistry in the C ring. The obtainment of a novel compound with a bynzylidenebenzylbutirolactone structure still leaves considerable scope for exploring biotransformations in order to obtain podophyllotoxin analogues via a combination of synthetic chemistry and biotechnological methods.

Animals↗

PubMed2000

Glutathione depletion induces apoptosis of rat hepatocytes through activation of protein kinase C novel isoforms and dependent increase in AP-1 nuclear binding.

Treatment of isolated rat hepatocytes with the glutathione depleting agents L-buthionine-S,R-sulfoximine or diethylmaleate reproduced various cellular conditions of glutathione depletion, from moderate to severe, similar to those occurring in a wide spectrum of human liver diseases. To evaluate molecular changes and possible cellular dysfunction and damage consequent to a pathophysiologic level of GSH depletion, the effects of this condition on protein kinase C (PKC) isoforms were investigated, since these are involved in the intracellular specific regulatory processes and are potentially sensitive to redox changes. Moreover, a moderate perturbation of cellular redox state was found to activate novel PKC isoforms, and a clear relationship was shown between novel kinase activation and nuclear binding of the redox-sensitive transcription factor, activator protein-1 (AP-1). Apoptotic death of a significant number of cells, confirmed in terms of internucleosomal DNA fragmentation was a possible effect of these molecular reactions, and was triggered by a condition of glutathione depletion usually detected in human liver diseases. Finally, the inhibition of novel PKC enzymatic activity in cells co-treated with rottlerin, a selective novel kinase inhibitor, prevented glutathione-dependent novel PKC up-regulation, markedly moderated AP-1 activation, and protected cells against apoptotic death. Taken together, these findings indicate the existence of an apoptotic pathway dependent on glutathione depletion, which occurs through the up-regulation of novel PKCs and AP-1.

Adenosine Triphosphate↗

PubMed2000

Oxidative stress induces increase in intracellular amyloid beta-protein production and selective activation of betaI and betaII PKCs in NT2 cells.

Amyloid beta-protein (Abeta) aggregation produces an oxidative stress in neuronal cells that, in turn, may induce an amyloidogenic shift of neuronal metabolism. To investigate this hypothesis, we analyzed intra- and extracellular Abeta content in NT2 differentiated cells incubated with 4-hydroxy-2,3-nonenal (HNE), a major product of lipid peroxidation. In parallel, we evaluated protein kinase C (PKC) isoenzymes activity, a signaling system suspected to modulate amyloid precursor protein (APP) processing. Low HNE concentrations (0.1-1 microM) induced a 2-6 fold increase of intracellular Abeta production that was concomitant with selective activation of betaI and betaII PKC isoforms, without affecting either cell viability or APP full-length expression. Selective activation of the same PKC isoforms was observed following NT2 differentiation. Our findings suggest that PKC beta isoenzymes are part of cellular mechanisms that regulate production of the intracellular Abeta pool. Moreover, they indicate that lipid peroxidation fosters intracellular Abeta accumulation, creating a vicious neurodegenerative loop.

Amyloid beta-Peptides↗

PubMed2000

Localization of cerebral arterovenous malformations using digital angiography.

Since 1989 we performed stereotactic radiotherapy treatments of cerebral arterovenous malformations (AVM), estimating three-dimensional (3-D) localization and shape of target volumes by the Leksell stereotactic helmet on two orthogonal radiographic projections. Due to the limitations of this method, we developed a new technique for the localization of the target volume using digital subtraction angiography (DSA) and digital image processing. To achieve this result we first developed a method to correct nonlinear distortion of DSA images using spatial relocation of image pixels based on a calibration grid. We then developed an algorithm for localization of the target volume using two independent DSA projections. Target volume coordinates in the helmet system are calculated using two DSA acquisitions taken with a free angle (approximately 90 degrees), one in the AP and the other in the LL direction. The helmet can be freely positioned between the x-ray source and the image plane. The projections of eight reference points inserted in the helmet at a known location, are used to calculate the transformation matrix between the two coordinate systems. We performed numerical and experimental validation of the system. A hypothetical random error (up to 2 mm) on image coordinates of the reference points allowed to determine that the error in target localization was less than 0.2 mm. Using DSA images of target points with a known location within a phantom, the error between calculated and actual location was, on average, 0.30+/-0.13 mm (mean+/-SD), with a maximum error of 0.49 mm. The results of numerical and experimental validations show that the system we have developed allows fast and accurate localization of the center of the target volume and it is suitable for efficient guiding during stereotactic radiosurgery of AVM.

Algorithms↗