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Biomedical subjects

F Zanardi

Publications and source records attributed to F Zanardi.

At least 19 recordsLinked to original sources

Variable strategy toward carbasugars and relatives. 2. Diversity-based synthesis of beta-D-xylo, beta-D-ribo, beta-L-arabino, and beta-L-lyxo 4a-carbafuranoses and (4a-carbafuranosyl)thiols.

The silyloxy diene-based construction of carbasugars, previously exploited for the synthesis of four carbocyclic furanose and pyranose analogues, has been investigated further. By introducing a novel silylative cycloaldolization protocol and by adjusting a couple of minor transformations, the efficiency of this synthetic sequence was greatly improved. Through a series of lactone/thiolactone aldehyde cyclization precursors, four carbafuranoses (4a-carba-beta-D-xylofuranose, 4a-carba-beta-D-ribofuranose, 4a-carba-beta-L-arabinofuranose, and 4a-carba-beta-L-lyxofuranose) and four (carbafuranosyl)thiols [(4a-carba-beta-D-xylofuranosyl)thiol, (4a-carba-beta-D-ribofuranosyl)thiol, (4a-carba-beta-L-arabinofuranosyl)thiol, and (4a-carba-beta-L-lyxofuranosyl)thiol] were assembled. From this study, it was shown that these constructions tolerate a variety of precursors, and in many instances, they are suitable for scaling-up.

Journal Article↗

Variable strategy toward carbasugars and relatives. 1. Stereocontrolled synthesis of pseudo-beta-D-gulopyranose, pseudo-beta-D-xylofuranose, (pseudo-beta-D-gulopyranosyl)amine, and (pseudo-beta-D-xylofuranosyl)amine.

Four novel, chiral nonracemic carbasugars have been synthesized from 1,2-O-isopropylidene-D-glyceraldehyde. Furan- and pyrrole-based 2-silyloxy dienes--mimics of the alpha,gamma-dianions of gamma-hydroxy- and gamma-aminobutanoic acid, respectively--nicely served to complete the syntheses of two all-oxygen compounds, pseudo-beta-D-gulopyranose and pseudo-beta-D-xylofuranose, and two "anomeric" amino derivatives, (pseudo-beta-D-gulopyranosyl)amine (1,2,4-tri-epi-validamine) and (pseudo-beta-D-xylofuranosyl)amine. Two sequential, highly diastereoselective carbon-carbon bond-forming maneuvers, i.e., a vinylogous crossed aldol addition and an intramolecular aldolization, proved central to these constructions. The fact that readily available heterocyclic diene scaffolds can be employed in the assembly of a varied repertoire of carbasugars and analogues widens the prospects of dienoxy silane chemistry.

Carbohydrates↗

The utility of furan-, pyrrole-, and thiophene-based 2-silyloxy dienes as demonstrated by modular synthesis of annonaceous acetogenin core units and their pyrrolidine and thiolane analogues.

We report a modular strategy for obtaining the core units of annonaceous acetogenins and their nitrogen and sulfur analogues, which generates great structural diversity. This synthesis is based on the application of a reiterative vinylogous addition protocol involving a unique triad of silyloxy diene modules, 2-[(tert-butyldimethylsilyl)oxy]furan (TBSOF), N-(tert-butoxycarbonyl)-2-[(tert-butyldimethylsilyl)oxy]pyrrole (TBSOP), and 2-[(tert-butyldimethylsilyl)oxy]thiophene (TBSOT) and suitable heteroatom-stabilized carbenium ions. By combining TBSOF, TBSOP, and TBSOT nucleophilic synthons with certain tetrahydrofuran, pyrrolidine, and thiolane acceptors, the construction of varied, adjacently linked oligo-heterocyclic motifs related to the core segments of the annonaceous acetogenins is assured. At first, the reliability of the pivotal coupling maneuver was certified, by assembling a collection of 18 model constructs, covering all oxygen, nitrogen, and sulfur heteroatom combinations (i.e., compounds 7-9, 13-15, and 19-21). This uniformed protocol was then suited to forge advanced bis-tetrahydrofuran, bis-pyrrolidine, and bis-thiolane scaffolds encompassing the heterocyclic core portion of various binuclear annonaceous acetogenins and relatives. The utility of this synthesis was demonstrated by the preparation of a repertoire of eight isomeric bis-tetrahydrofuran units, 41-48, two bis-pyrrolidine units, 62 and 63, and four bis-thiolane units, 78-81.

Furans↗

Expeditious syntheses of sugar-modified nucleosides and collections thereof exploiting furan-, pyrrole-, and thiophene-based siloxy dienes.

A series of individual sugar-modified pyrimidine nucleosides including enantiomerically enriched 2',3'-dideoxynucleosides 14a-c (alpha and beta anomers of L- and D-series), 2',3'-dideoxy-4'-thionucleosides 21a-c (alpha and beta anomers of L- and D-series), and 2',3'-dideoxy-4'-azanucleosides 28a-c (beta anomers of L- and D-series) were synthesized, with uniform chemistry and high stereochemical efficiency, exploiting a triad of versatile heterocyclic siloxy dienes, namely, 2-(tert-butyldimethylsiloxy)furan (TBSOF), 2-(tert-butyldimethylsiloxy)thiophene (TBSOT), and N-(tert-butoxycarbonyl)-2-(tert-butyldimethylsiloxy)pyrrole (TBSOP). The synthetic procedure advantageously used both enantiomers of glyceraldehyde acetonide (D-1 and L-1) as sources of chirality and as synthetic equivalents of the formyl cation. The outlined chemistry also allowed for the rapid assemblage of a 30-member collection of racemic nucleosides (D,L-L) as well as one 15-member ensemble of chiral analogues (L-L), along with some related sublibraries.

Furans↗

a 49-year-old woman with dyspnoea, palpitations and syncope.

Pulmonary hypertension is rarely described in association with Sjögren's syndrome. The authors report the case of a patient in which pulmonary hypertension was the inaugural clinical manifestation of primary Sjögren's syndrome. Clinical assessment, differential diagnosis, etiopathological implications, and therapeutic approach are discussed.

Diagnosis, Differential↗

[Carcinoid of Meckel's diverticulum].

The carcinoid of Meckel's diverticulum is a very rare lesion, and about 100 cases in the literature have been described. Most of these tumors are casually find out at autopsy or laparoscopy for other pathology. Seldom was described a sintomatology correlated to carcinoid of Meckel's diverticulum presence, except the rare case where was formed a carcinoid syndrome. Authors present a clinical case where was casually found by a carcinoid of Meckel's diverticulum during an appendicectomy. The intention is to underline the importance of research the Meckel's diverticulum every time, and in particular in case of young subjects, remove it and perform an histological valuation, to exclude the presence of a carcinoid that could give metastases to local lymph-nodes or liver.

Carcinoid Tumor↗

[Primary and secondary hyperparathyroidism. Analysis of our results].

The Authors introduce their experience of primary and secondary surgical treatment of hyperparathyroidism, pointing out at first the good confidence of echography, scintigraphy and TAC, in the pre-operating diagnostic of the parathyroid glands localization and then the satisfactory clinical results with a follow-up which, up to date, has not shown any relapse.

Adenoma↗

[Familial arrhythmogenic dysplasia of the right ventricle. Observation of 3 cases].

A family with "arrhythmogenic right ventricular dysplasia (ARVD)" is described. ARVD is pathologically characterised by a partial or total degeneration of the right ventricular myocardium, replaced by fatty and fibrous tissue. This causes dangerous ventricular arrhythmias or congestive heart failure in infancy. About the three described patients, a sixteen-year-old subject died suddenly, and his anatomical and histopathological reports have been presented. Familiarity, rarely treated in literature, and the presence, in the died subject, of a damage of the left ventricle too, are the peculiar characteristic of these "ARVD" cases. The importance about instrumental non-invasive studies has been underlined in order to know early "ARVD", which can be deceptive clinically. The authors suppose there is surely, at the beginning of "dysplasia", a genetic alteration of the right cardiac musculature, but acquired noxae could insert afterwards, on this genetic basis.

Adolescent↗

[Apropos of a case of intra-uterine supraventricular tachycardia].

A case of intrauterine paroxysmal supraventricular tachycardia (PSVT)--without heart malformations and fetal cardiac failure at the echographic assessment--is reported. After birth, the EKG of the newborn documented recurrent accesses of reentrant PSVT, likely related to the presence of a concealed Kent's bundle in the reentry circuit. Mother and grand-father of the newborn were affected by Lown-Ganong-Levine syndrome. The familial occurrence of pre-excitation syndromes--with different by-passes--and the possibility of autosomal inheritance are discussed. The importance of early identification of fetal cardiac dysrythmias and/or failure by monitoring pregnancies with familial history of PSVT is emphasized. Pharmacological approaches of fetal supraventricular tachycardia, as reported by several Authors in the literature, are presented.

Adult↗

[Value and limits of echocardiography of the acute or previous myocardial infarction. Mono- and bi-dimensional study (author's transl)].

81 subjects with acute or previous myocardial infarction were studied in order to assess the relations between ecg location and diskinetic zones as seen on the echocardiogram; another purposes of the work was to establish if serial echocardiographic measurements would be useful for prognostic purposes. The obtained results were the following: 1) there is a good correlation between ecg location of anterior infarction and diskinetic or ipokinetic zones if on the echocardiographic pattern were simultaneously present the following echocardiographic findings: lessened systolic escursion + lessened systolic thickening + enhanced left ventricular diastolic dimension (LVDD); 2) in the group of posterior and inferior infarctions is observed either an ipokinetic left ventricular posterior wall either an ipokinetic septum; 3) left ventricle diastolic dimension (LVDD) was greater and the motion of the septum was less frequently paradoxical in previous infarction than in acute infarction; 4) there was a good correlation in anterior acute infarction among M-mode echo-patterns which indicate both progressive dilatation of the left ventricle and an abnormal septum movement and the appearance of congestive failure, shock and intrahospital mortality; 5) the aneurysms localized in apical section of the ventricles could be missed by M-mode studies and therefore when this complication is suspected bidimensional investigations are more indicated.

Adult↗

[A case of Churg-Strauss granulomatous angiitis: an autonomous clinical entity or a variant of panarteritis nodosa?].

A fatal case of Churg and Strauss granulomatous angiitis in a 21-yr-old woman is described. Its unusual features included marked personal and familial dysreaction, sudden onset, bronchopulmonitis with distinct eosinophilia and antibiotic- and cortisone-resistant pericarditis, and a terminal picture of generalised septico-pyaemia. The histological findings included necrotising systemic vasculitis with granulomas, some of them extravascular, in various organs. Differential diagnosis and the relation between this form and panarteritis nodosa are discussed.

Adult↗

[The reliability of several polycardiographic indices in the quantitative evaluation of mitral stenosis (author's transl)].

In 21 patients with pure, isolated mitral stenosis, four hemodynamic parameters were studied. They were obtained by left and right cardiac catheterization and were: the mean pulmonary artery wedge pressure, the diastolic mitral gradient, the stroke volume and the mitral valve area with one or more parametres amd polycardiographic indices, to verify the reliability of the quantitative evaluation of mitral stenosis by noninvasive methods. The polycardiographic indices of Yigitbasi (r = 0.76) and Wells (r = 0.65) were best correlated with the mean pulmonary wedge pressure. The only index with a moderate correlation (r = 0.60) with the mitral diastolic gradient was that of Wells. The LVET/PEP index has only a mediocre correlation with the stroke volume (r = 0.50). The Oreshkov index was the only one among those studies to correlate at all significantly with the mitral valve area (r = --0.62). The investigation confirms the practical use of noninvasive methods in predicting the pulmonary wedge pressure, whilst the indices of Wells and Oreshkov seem less satisfactory in prediction both for the mitral diastolic gradient and the mitral valve area.

Adult↗

[Phono-mechanographic aspects in parietal blocks of left ventricle (author's transl)].

20 subjects with parietal ventricular block, detected by Frank vectoracardiogram, were submitted to phono-mechanographic examination. Prolongation of PEP was shown; the second period of electromechanical interval (A-C interval in apex-cardiogram) was given in detail. Isovolumetric contraction, systolic ejection time and diastolic period were normal. This pattern is quite typical for parietal block and completely differs from bundle blocks and cardiomyopathies. Therefore it may be useful in differntial diagnosis of these kinds of conduction disturbances as well.

Aged↗