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Biomedical subjects

A Martinelli

Publications and source records attributed to A Martinelli.

At least 37 records · Page 2Linked to original sources
PubMed1998

A five-year-old with a dental abscess: a case study.

Dental caries remain one of the most common disorders of childhood in the United States. Often nurse practitioners (NPs) will see children who are suffering from the complications of a dental carie, such as a dental abscess and/or cellulitis. This article describes the case of a 5-year-old girl who presented at an evening clinic with tooth pain, fever, and facial swelling. Three treatment choices are discussed: (1) 400 mg of amoxicillin (Augmentin), by mouth, with comfort measures, and return to the clinic in the morning; (2) 2 g of ceftriaxone by injection, with comfort measures, and return to the clinic in the morning; (3) or hospitalize via emergency department for intravenous fluids and antibiotics. The treatment that was chosen not only takes into account the disease process, but also the impact of this choice on the family. A model for the progression of dental caries in low-income groups with recommendations for prevention is also presented.

Child, Preschool↗
PubMed1997

Gender and the relationship between ventricular repolarization and cardiac cycle length during 24-h Holter recordings.

AIMS: There are gender-related differences in the QT interval measured from standard ECG tracings. However, these observations are based on a limited number of beats recorded in resting conditions. Computerized Holter techniques enable ventricular repolarization and its relationship with cardiac cycle length to be analysed long term. Previous studies used only the initial portion of the QT interval to the T wave apex (QTa) to measure ventricular repolarization; however, QTa may underestimate the total QT duration (QTe). The aims of this study were to verify whether QTa and QTe had similar rate-dependence in normal subjects and whether gender-related QTe differences observed in the resting ECG were also present in the long-term QT intervalcycle length relationship. METHODS AND RESULTS: Twenty-four hour Holter recordings were obtained in 40 healthy young subjects. 20 females and 20 males (mean age 28 +/- 9 and 26 +/- 5 years, respectively ns). Two-channel ECG digitized signals were processed using new automatic QT analysis software (Ela Medical), which converted the 24-h recordings into 2880 30-s templates. It also measured the QT apex (QTa) QT end (QTe) and the RR interval (ms) of each template, and computed the slopes of the linear regressions of QTe and QTa values plotted against the corresponding RR interval (QTe/RR and QTa/RR). Females had a shorter RR interval than males (803 +/- 129 vs 877 +/- 86 ms. P = 0.037), with longer mean QTc (420 +/- 17 vs 400 +/- 200 ms. P = 0.0005). In both genders. QTa/RR slopes were steeper than QTe/RR slopes (P = 0.0001). Both QTa/RR and QTe/RR slopes were steeper in females than in males (QTa/RR 0.20 +/- 0.04 vs 0.16 +/- 0.03, P = 0.001; QTe/RR 0.16 +/- 0.04 vs 0.13 +/- 0.03, P = 0.027). Of note, QTa and QTe at fixed long cycle lengths (1000 ms) were longer in women than in men (QTa1000 330 +/- 20 vs 309 +/- 18 ms: P = 0.002; QTe1000 410 +/- 17 vs 389 +/- 19 ms: P = 0.002), while they did not differ at fixed short cycle lengths (600 ms). CONCLUSIONS: This study demonstrates that both the initial portion of the QT interval (QTa) and the entire QT interval (QTe) are useful since QTa is more prolonged than QTe at increasing cycle lengths, and thus includes most of the heart rate dependency of ventricular repolarization. In normal subjects, both the QTc and the long-term relationship between ventricular repolarization and heart rate are affected by gender. The differences in QTa and QTe duration between males and females are more marked at long cycle lengths and disappear at short cycle lengths. Finally, this study also proves the clinical feasibility of assessing the long-term relationship between ventricular repolarization and heart rate by utilizing the automatic measurement of the QT interval from 24-h Holter recordings.

Adult↗
PubMed1996

New polyurethane compositions able to bond high amounts of both albumin and heparin. II: Copolymers and polymer blends.

Haemocompatible new urethane copolymers and polymer blends containing, in the chain extender, a long chain alkyl group (able to bond albumin) or a tertiary ammonium group able, after suitable quaternization reaction, to bind ionically significant amounts of heparin, were prepared. The copolymers were characterized by differential scanning calorimetry, intrinsic viscosity determinations, infrared spectroscopy and nuclear magnetic resonance (1H and 13C). Biological in vitro evaluation has shown that the adsorption sequence for albumin and heparin, respectively, onto films of the various copolymers and blends, exerts a great influence. From scanning electron microscopy measurements it was seen that the bonding type of albumin to the polymer films plays a determining role on the platelet activation. A phase segregation occurring on the polymer blends surface was demonstrated by X-ray photoelectron spectroscopy measurements.

Biocompatible Materials↗
PubMed1996

1,2,3-triazolo[1.5-a]quinazolines: synthesis, benzodiazepine receptor binding and theoretical calculations.

This paper reports the synthesis of 3-substituted-1,2,3-triazolo[1,5-a]quinazolin-5-ones prepared by 1,3-dipolar cycloaddition reaction of 2-azidobenzoic acid to methylenic compounds activated by a cyano group. The new derivatives were submitted to benzodiazepine receptor binding assays: the results indicated an interesting receptorial affinity of the 1,2,3-triazolo[1,5-a]quinazoline ring. On the basis of the biological results, theoretical calculations were performed, which suggested useful structural modifications.

Animals↗
PubMed1995

New polyurethane compositions able to bond high amounts of both albumin and heparin. Part I.

In order to prepare polymers provided with better haemocompatibility with respect both to the coagulative cascade and to platelet aggregation and activation, we have synthesized new polyurethanes containing in the chain-extender [di(2-hydroxyethyl)hexadecylamine] both a long chain alkyl group (able to bond albumin) and a tertiary ammonium group able, after suitable quaternization reaction, to bind ionically significant amounts of heparin. The amounts of heparin and albumin bonded to the polymer films were determined spectrophotometrically. A biological in vitro evaluation of the heparinized and albuminized films was also carried out with respect to blood coagulation factors (by activated partial thromboplastin time measurements) and to platelet adhesion and activation (by platelet count and scanning electron microscopy examination). It was seen that the type of adsorption sequence for albumin and heparin, respectively, onto the various homo- and copolymer films, plays an important role on their biological properties; the possible mechanisms involved are also discussed on the basis of X-ray photoelectron spectroscopy and attenuated transmission reflectance evaluation of the polymer surfaces.

Albumins↗
PubMed1995

Synthesis, antiinflammatory activity and platelet antiaggregating activity of a new series of beta-aminoxypropionic acids.

A series of beta-aminoxypropionic acids (AOPAs) had previously been designed and synthesised as analogues of antiinflammatory arylacetic acids (ArAAs) in which the Ar portion is substituted by the (methyleneaminoxy) methyl moiety (C = NOCH2, MAOMM). Most of these AOPAs had exhibited a significant antiinflammatory and antiaggregating activity. This paper reports the synthesis of a new series of beta-aminoxypropionic acids (SAOPAs) which include the saturated (methylaminoxy)methyl moiety (CHNH-OCH2, SMAOMM) in the place of the MAOMM present in AOPAs. The antiinflammatory activity of SAOPAs was evaluated by the carrageenan-induced paw edema method and the antiaggregating activity was evaluated by means of tests using arachidonic acid (AA) and adenosine diphosphate (ADP) as the aggregating agents. Two SAOPAs were evaluated for their capacity to inhibit the cyclooxygenase enzyme by measuring the malondialdehyde (MDA) produced by incubation of sodium arachidonate with platelet-rich plasma (PRP). The pharmacological results showed that the saturation of the iminic double bond led to a reduction or even the disappearance of the antiaggreganting activity, whereas it did not induce any evident changes in the antiinflammatory activity. Theoretical studies were carried out in order to compare the conformation and the molecular reactivity of SAOPAs with those of AOPAs.

Animals↗
PubMed1995

(E)-(arylmethyleneaminoxy)acetamides as analogues of neuroleptic benzamides: synthesis and D2-dopaminergic binding affinity.

Some type B (E)-(arylmethyleneaminoxy)acetamides were synthesised as analogues of type A neuroleptic and antipsychotic benzamides, in which the aromatic group is substituted by a (methyleneaminoxy)methyl moiety (C = NOCH2, MAOMM). Theoretical studies were performed in order to verify whether conformational analogies could exist between type A and type B compounds. Type B compounds were tested for their D2-dopaminergic binding affinity which represents a valid indication of their potential neuroleptic and antipsychotic properties. Biological results indicate that the MAOMM is not able to substitute the aromatic group effectively in the field of neuroleptic benzamides. The results are discussed in the light of the structural analogies and the differences between the MAOMM and the aryl.

Acetamides↗
PubMed1994

The [(methyloxy)imino]methyl moiety as a bioisoster of aryl. A novel class of completely aliphatic beta-adrenergic receptor antagonists.

Previous studies in the field of beta-adrenergic drugs had supported the hypothesis of the existence of a bioisosterism between the [(methyleneamino)oxy]methyl moiety (C = NOCH2, MAOMM) of type B beta-blocking drugs and the aryl (Ar) of type A beta-blocking agents. In the MAOMM, however, the carbon of the CH2 linked to the oximic oxygen possesses a hybridization (sp3) and a geometry different from those of the corresponding carbon of Ar which possesses an sp2 hybridization. Furthermore, in the MAOMM, in its preferred conformation, the unsaturated portion (C = N) is situated in a spatial area which does not correspond exactly to the area occupied by Ar. The formal inversion of the atomic sequence C = NOCH2 of the MAOMM leads to a different type of group, the [(methyloxy)imino]methyl moiety (CH2ON = C, MOIMM), which, in the E configuration, appears to present greater steric and electronic analogies with an Ar, with respect to the MAOMM. On the basis of these observations, some completely aliphatic (E)-N-(3-amino-2- hydroxypropylidene)(alkyloxy)amino derivatives of type C (11a,b and 12a, b) were synthesized, the their beta-adrenergic properties were compared with those of the corresponding [(methyleneamino)oxy]-methyl isomers of type B (19a, b and 20a, b). The similar beta-adrenergic properties of 11, 12 and 19, 20 evaluated in vitro both by radioligand binding assays and by functional tests on isolated preparations, are discussed on the basis of considerations regarding the spatial correspondences and electronic analogies between the MOIMM and the MAOMM.

Adrenergic beta-1 Receptor Antagonists↗
PubMed1994

Arylsulphatase A (ASA) activity in parkinsonism and symptomatic essential tremor.

Arylsulphatase A (ASA) activity was evaluated in 47 patients with a diagnosis of parkinsonism or essential tremor. Mean ASA activity was significantly reduced compared with both a healthy control group of 71 individuals (p < 0.01) and with a group of 44 neurological patients without movement disorders (p < 0.02). Using definite clinical criteria the patients were classified as typical or atypical with respect to Parkinson's disease (PD) or essential tremor (ET). A normal ASA level was found in all the cases showing typical clinical features (PD and ET), while ASA activity was significantly lowered (p < 0.01) in 55.6% of the atypical cases (Parkinsonian syndrome or symptomatic ET). Our data support the hypothesis of a non-casual association between low ASA level and the clinical features of parkinsonism or symptomatic ET.

Aged↗
PubMed1994

Synthesis and beta-adrenergic activity of new completely aliphatic 3-(methyleneaminoxy)propanolamine derivatives.

In a previous paper, it had been found that completely aliphatic 3-(methylene aminoxy)propanolamine derivatives showed a good beta-blocking adrenergic activity directed prevalently towards beta 2-tracheal receptors. In an attempt to change the beta-adrenergic properties of these compounds from antagonist to agonist, while still retaining the beta 2-selectivity, a series of new completely aliphatic 3-(methyleneaminoxy)propanolamine derivatives were designed in which either a hydroxylic or a methoxylic group was present on the aliphatic portion linked to the oximic carbon. The synthesis of the new compounds and their beta-adrenergic activity, evaluated by means of functional tests on isolated preparations, are described and discussed; the results obtained are then rationalised on the basis of their conformational and reactivity characteristics, determined by means of theoretical methods.

Adrenergic Agents↗
PubMed1994

2-(Methyleneaminoxy)methylmorpholine derivatives. Synthesis and antidepressant activity.

The 3-(methyleneaminoxy)methylmorpholines 2 were synthesized as analogues of viloxazine 1, an antidepressant drug, in which the aryloxymethyl group is substituted by a (methyleneaminoxy)methyl moiety (MAOMM). Compounds 2 were tested as potential antidepressant agents by using the test of antagonism to reserpine-induced hypothermy in mice. In addition, their anticholinergic and antihistaminic activity on isolated preparations and their ability to antagonize the toxicity induced by adrenaline in mice were evaluated. "In vivo" and "in vitro" tests showed that some compounds of type 2 possess a pharmacological profile similar to that of viloxazine 1.

Animals↗
PubMed1994

Bioisosters of the diphosphate group in activated forms of antiherpes virus agents. A theoretical study.

In order to identify potential bioisosteric replacements for the diphosphate moiety, which is present in activated forms generated from antiherpes virus agents during their inhibitory action against herpes viruses, 5'-phosphonoacetamido (4) and 5'-O-sulfamoylcarbamoyl (5) derivatives of idoxuridine were synthesised as analogues of idoxuridine 5'-diphosphate (6). In this paper we report on the antiherpetic activity of 4 and 5. Moreover, a theoretical study is presented in which both the conformational and the electronic characteristics of 4 and 5 are compared with those of the diphosphate metabolite of idoxuridine (6), in order to verify the possibility of bioisosterism relationship between the phosphonoacetamido, the sulfamoylcarbamoyl and the diphosphate group.

Antiviral Agents↗
PubMed1993

Conformationally restrained analogs of sympathomimetic catecholamines. Synthesis, conformational analysis, and adrenergic activity of isochroman derivatives.

In previous papers dealing with the study of the conformations and the biopharmacological activity of conformationally restrained analogs of sympathomimetic catecholamines (NE and ISO), proposals were advanced for the three-dimensional molecular models A, B, and C; these models provided information about the steric requirements for the direct activation of alpha 1, alpha 2,beta 1, and beta 2 adrenoceptors, respectively. The 1-(aminomethyl)-6,7-dihydroxyisochromans 11 and 12 and the 1-(aminomethyl)-5,6-dihydroxyisochromans 13 and 14 (1-AMDICs) are two different types of semirigid analogs of NE and ISO. The alpha 1, alpha 2, beta 1, and beta 2 adrenergic properties of the 1-AMDICs 11-14 were evaluated in vitro, both by radioligand binding assays and by functional tests on isolated preparations, and were compared with those of their parent compounds (NE and ISO). The results of a conformational study carried out by means of both 1H NMR spectrometry and theoretical calculations indicated that, in these 1-AMDICs, the presumed active groups (aryl moiety, amine nitrogen and benzylic ethereal oxygen) are in a spatial relationship corresponding to the one found for NE and ISO in their preferred conformations, which also proved to be the pharmacophoric conformation in the models A-C. By means of a comparison of the stereostructures of the 1-AMDICs 11-14 with their biopharmacological properties, it was possible to obtain a further definition of the model B with respect to the activation of the alpha 2 adrenoceptors; the superimposition of the 1-AMDICs 11 and 12 with the molecular model C made it possible to detect an area of the beta-adrenergic receptors which might hinder the fit of adrenergic drugs that are analogs of catecholamines with these receptors.

Animals↗
PubMed1993

Familial idiopathic strio-pallido-dentate calcifications with late onset extrapyramidal syndrome.

A family with autosomal dominant inheritance of idiopathic strio-pallidodentate calcifications and late onset of extrapyramidal symptoms is reported. Clinical features consisted of parkinsonism in one member and postural tremor in two. Depression and dysarthria were present in all cases. All symptomatic members showed a peculiar biochemical abnormality consisting of reduced 25-OH vitamin D3 with normal levels of 1,25(OH)2 vitamin D3, suggesting an inborn error of Vitamin D metabolism. The biochemical, clinical, and genetic pattern of this family distinguishes this syndrome from the larger group of secondary familial basal ganglia calcifications.

Adult↗
PubMed1993

Lacunar syndromes due to non ischaemic causes: prevalence and clinical findings (study of 19 patients).

137 consecutive patients with Lacunar Syndrome (LS) were studied in order to evaluate the prevalence between ischaemic and not ischaemic forms. The lacunar infarcts (LI) were 118, the not ischaemic ones 19. These latter were caused by primary intracerebral hemorrhages with rapid recovery (12 cases), multiple sclerosis (3 cases) and unruptured top of the basilar aneurysm, chronic subdural haematoma, Arnold-Chiari malformation type 1, multiple metastases (1 case respectively). In this paper we discussed the probable pathogenetic mechanism and the clinical features in the 19 cases of not ischaemic LS. Moreover, FISHER'S opinion that LS are nearly always due to LI is here discussed.

Adult↗
PubMed1992

Conformational effects on the activity of drugs. 13. A revision of previously proposed models for the activation of alpha- and beta-adrenergic receptors.

The alpha 1-, alpha 2-, beta 1-, and beta 2-adrenergic properties of the 2-(3,4-dihydroxyphenyl)morpholines 3 and 4 (2-DPMs), of the 3-(3,4-dihydroxyphenyl)-3-piperidinols 5 and 6 (3-DPPs), and of the trans-2-amino-5,6-dihydroxytetrahydronaphthalen-1-ols 7 and 8 and the trans-2-amino-6,7-dihydroxytetrahydronaphthalen-1-ols 9 and 10 (2-ADTNs) were evaluated in vitro both by radioligand binding assays and by functional tests on isolated preparations and compared with those of norepinephrine (NE, 1) and isoprenaline (ISO, 2). Through a comparison of the stereostructures of the compounds examined with their biopharmacological properties, it was possible to revise previously proposed molecular models for the direct activation of alpha- and beta-adrenergic receptors. The revised models (A-C) provided information about the conformational requirements of adrenergic drugs, which substantially fit in with the results of several published studies involving conformationally-restricted adrenoceptor agonists. The different position of the catecholic hydroxyl groups in model B, which refers to the alpha 2 receptors, and in model C, which refers to the beta receptors, confirms the importance of the rotameric position of the aromatic ring of catecholamines in the interaction with the alpha- and beta-adrenergic receptor.

Animals↗
PubMed1992

Synthesis and physicochemical characterization of a hydrophilic polyurethane able to bind heparin.

The synthesis of a new segmented polyurethane containing quaternary ammonium groups in the side-chain is reported. The quaternization was carried out both on the polymer dissolved in an organic solvent and on polymer films. Polymeric films quaternized by both techniques were heparinized. The amount of bonded heparin, determined by spectrophotometry, was remarkably higher than previously described. Polymer quaternized in solution bonded more heparin than that heparinized directly on film. In vitro evaluations of antithrombogenicity by activated partial thromboplastin time (APTT) carried out on the films confirmed these data. The polymers were also characterized by chemical, i.r., n.m.r., differential scanning calorimetry and viscometric techniques.

Binding Sites↗