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Biomedical subjects

Giuseppe Romeo

Publications and source records attributed to Giuseppe Romeo.

16 recordsLinked to original sources
PubMed2006

New pyrimido[5,4-b]indoles and [1]benzothieno[3,2-d]pyrimidines: high affinity ligands for the alpha(1)-adrenoceptor subtypes.

A number of new pyrimido[5,4-b]indole and [1]benzothieno[3,2-d]pyrimidine derivatives were synthesized and evaluated for their binding and functional properties at alpha(1)-adrenergic receptor (alpha(1)-AR) subtypes. They behaved as potent alpha(1)-AR antagonists. In binding experiments, some of them (RC24 and RC23) showed very high affinity for the alpha(1D)-AR subtype.

Animals↗
PubMed2006

New 1,2,3,9-tetrahydro-4H-carbazol-4-one derivatives: analogues of HEAT as ligands for the alpha1-adrenergic receptor subtypes.

With the aim to develop new ligands able to discriminate among the three subtypes of alpha1-adrenergic receptors (alpha1A-AR, alpha1B-AR, and alpha1D-AR), a series of new 1,2,3,9-tetrahydro-4H-carbazol-4-ones bearing a 3-[[[2-(4-hydroxyphenyl)ethyl]amino]methyl] or a 3-[[4-(2-substitutedphenyl)piperazin-1-yl]methyl] side chain were synthesized. The general structure of the new compounds is reminiscent of HEAT and RN5, two potent alpha1-AR antagonists which show high affinities for all three alpha1-AR subtypes. Some derivatives in which one ring of the tetrahydrocarbazolone system was opened were also prepared. Compounds were tested in radioligand binding assays on human cloned alpha1A-AR, alpha1B-AR, and alpha1D-AR subtypes stably expressed in HEK293 cells. They showed moderate to good affinities, although their selectivity among the receptor subtypes hardly reached one order of magnitude.

Adrenergic alpha-1 Receptor Antagonists↗
PubMed2006

Prenatal testicular torsion: ultrasonographic features, management and histopathological findings.

AIM: To highlight the ultrasonographic features of prenatal torsion of the testis in utero (IUTT) at presentation, the neonatal management and the histological findings postorchiectomy or biopsy. METHODS: Seven newborns underwent emergency exploration for IUTT. All patients underwent a sonography and real-time color Doppler ultrasound study of the scrotum before any surgical procedure. A histological examination was performed in the removed specimens. RESULTS: Sonography of the scrotum revealed enlarged, heterogeneous testes. In all cases the color and power Doppler did not reveal any flow signal on the affected side. Four newborn with unilateral testicular torsion underwent orchiectomy and contralateral orchidopexy. In one neonate after detorsion and with the absence of gangrenous changes and a reassuring biopsy, a twisted testis could be treated conservatively with orchidopexy. In another case, the parents, acknowledging the inviability of the affected testis, gave consent only for a biopsy of the testis. In the neonate with bilateral IUTT, bilateral testicular biopsies were performed. Histology of the removed testes variably showed interstitial red cell extravasion and coagulation or hemorrhagic necrosis. Light microscopy of the preserved testis highlighted surviving seminiferous tubules, with gonocytes, spermatogonia and fetal Sertoli cells. CONCLUSIONS: An early diagnosis and treatment in IUTT is essential. Surgical exploration should be always performed through the inguinal route. In bilateral IUTT testes should be left to try to assure, as long as possible, a residual Leydig cell function.

Female↗
PubMed2005

Mid- and long-term effects on pulmonary perfusion, anatomy and diaphragmatic motility in survivors of congenital diaphragmatic hernia.

The aim of the present study was to evaluate the pulmonary sequelae and diaphragmatic motility in infant, adolescent and adult patients (pts) who had undergone the repair of a congenital diaphragmatic hernia. Thirty-one (81.5%) out of 38 survivors after left side CDH repair, without using a patch, were followed-up. They were subdivided in two groups. Group A (mid-term follow-up): 12 pts (39%) (5 males, 7 females) with a mean age of 4.5 years; Group B (long-term follow-up): 19 pts (61%) (9 males, 10 females) with a mean age of 21.0 years. All pts underwent physical examination, chest X-ray, diaphragmatic ultrasonographic (US) examination, pulmonary perfusion scintigraphy. Patients of the group B were also submitted to spirometry. All pts had a normal life-style and no one complained of respiratory symptoms. The chest X-ray revealed pathologic findings in 12 pts (39%). 8 pts (26%) showed chest wall alterations. The profile of the left diaphragmatic dome appeared irregular in 9 pts (29%). In all pts M-mode sonography disclosed a reduced diaphragmatic motility on the treated side. The mean pulmonary perfusion scintigraphy value on the affected side was 39.2+/-0.7%. The spirometric study showed normal values. We noted that the lung perfusion significantly and rapidly improved after CDH repair even the apparently hypoplastic and small lungs, the diaphragm maintained a good contractility during forced respiration.

Adolescent↗
PubMed2005

3-Arylpiperazinylethyl-1H-pyrrolo[2,3-d]pyrimidine-2,4(3H,7H)-dione derivatives as novel, high-affinity and selective alpha(1)-adrenoceptor ligands.

The discovery of a new series of selective and high-affinity alpha(1)-adrenoceptor (alpha(1)-AR) ligands, characterized by a 1H-pyrrolo[2,3-d]-pyrimidine-2,4(3H,7H)-dione system, is described in this paper. Some synthesized compounds, including 20, 22, and 30, displayed affinity in the nanomolar range for alpha(1)-ARs and substantial selectivity with respect to 5-HT(1A) and dopaminergic D(1) and D(2) receptors. Functional assays, performed on selected derivatives, showed antagonistic properties.

Chlorine↗
PubMed2005

Synthesis of 3-arylpiperazinylalkylpyrrolo[3,2-d]pyrimidine-2,4-dione derivatives as novel, potent, and selective alpha1-adrenoceptor ligands.

Novel compounds characterized by a pyrrolo[3,2-d]pyrimidine-2,4-dione (PPm) system connected through an alkyl chain to a phenylpiperazine (PPz) residue were designed as structural analogues of the alpha(1)-adrenoceptor (alpha(1)-AR) ligand RN5 (1). In this new series of derivatives an arylpyrrolo moiety has replaced the indole nucleus of RN5. Several structural modifications were performed on the PPm and PPz moieties and the connecting alkyl chain. These compounds were synthesized and tested in radioligand binding experiments where many of them showed interesting binding profiles. Some compounds, including 31, 34, and 36, displayed substantial alpha(1)-AR selectivity with respect to serotoninergic 5-HT(1A) and dopaminergic D(1) and D(2) receptors. Two different molecular modeling approaches (pharmacophoric mapping and quantitative structure-affinity relationship analysis) have been applied to rationalize, at a quantitative level, the relationships between affinity toward alpha(1)-ARs and the structure of the studied compounds. Several QSAR models have been reported and described, accounting for the influence of various molecular portions on such affinity data.

Algorithms↗
PubMed2005

A facile synthesis of new 2-carboxamido-3-carboxythiophene and 4,5,6,7-tetrahydro-2-carboxamido-3-carboxythieno[2,3-c]pyridine derivatives as potential endothelin receptors ligands.

Endothelins (ETs) are the most ubiquitous, highly potent and unusually long-lasting peptidic constrictors of human vessels known. Elevated levels of the plasma concentration of ETs were observed in several diseases such as hypertension, acute myocardial infarction, congestive heart failure, renal failure, pulmonary hypertension, and atherosclerosis. ETs exert their activities via specific seven-transmembrane, G protein-coupled receptors. To date two receptor subtypes, endothelin A (ET(A)) and endothelin B (ET(B)), have been identified and cloned. A literature survey revealed that a number of compounds that bind ET receptors with affinity and selectivity are known, nevertheless these compounds belong only to few chemical classes. The aim of this work is the identification of an "hit compound" with novel chemical structure endowed with reasonable ET affinity and selectivity. Accordingly, new variously substituted 2-carboxamido-3-carboxythiophene derivatives (29-52) were synthesized. These compounds were tested for their ability to inhibit ETs binding in radioligand binding assay using CHO cells stably expressing human ET(A) and ET(B) receptors.

Animals↗
PubMed2005

Novel (E)-alpha-[(1H-indol-3-yl)methylene]benzeneacetic acids as endothelin receptor ligands.

Endothelin-1 (ET-1), a peptide of 21 amino acid residues, is the most potent vasoconstrictor substance known and now it is understood to be one of a family of three mammalian vasoactive peptides that also includes ET-2 and ET-3. The endothelins (ETs) affect multiple organ systems and seem to be involved in the pathogenesis of many diseases such as hypertension, pulmonary hypertension, atherosclerosis, apoptosis inhibition and angiogenesis. The ETs exert their effects via activation of two distinct G-protein coupled receptor subtypes termed ET(A) and ET(B). To date a number of ET receptor ligands with good affinity and selectivity is known, nevertheless these compounds belong only to few chemical classes. The aim of this work was the identification of a "hit compound" with novel chemical structure, endowed with reasonable ET affinity and selectivity. Accordingly, a new class of (E)-alpha-[(1H-indol-3-yl)methylene]benzeneacetic acid derivatives (1-23) was synthesized for evaluation of their binding profiles.

Acetic Acid↗
PubMed2005

Long-term functional evaluation of diaphragmatic motility after repair of congenital diaphragmatic hernia.

BACKGROUND/PURPOSE: A few studies have taken into account the diaphragmatic function in patients successfully treated for congenital diaphragmatic hernia (CDH). Monodimensional sonography has been reported to be useful in assessing the diaphragmatic motility. Aim of the present study was to investigate, in a long-term follow-up, the diaphragmatic function after CDH repair. METHODS: Ten patients, with a mean age of 16 (5-26) years, were enrolled. All had had a left diaphragmatic hernia repaired, but no one received a patch. Ten subjects of matched age were used as controls. The diaphragmatic excursions appear, at M-mode sonography, as a sinusoid; the amplitude of the curve on the vertical axis measured the movement in centimeters. Chest x-ray and spirometry were also performed in CDH patients. RESULTS: A reduced diaphragmatic motility on the left (treated) side was recorded. The amplitude of the contraction was significantly reduced when compared with the contralateral side (1.19 +/- 0.2 vs 2.33 +/- 0.9 cm; P = .017) and was also significantly reduced in comparison with the motion of the left side of controls (1.19 +/- 0.2 vs 1.83 +/- 0.4 cm; P = .01). There was no difference in the amplitude of contraction between the left and right sides of control patients and between the right side of CDH patients and the controls. Spirometry was normal in all patients but one, who had a slight reduction of ventilation on the left side. CONCLUSION: M-mode sonography appears as a very useful tool in quantitative evaluation of diaphragmatic movements and should be extensively used during follow-up of patients after CDH repair. Motility of the repaired diaphragmatic is reduced, even after a long period, but this does not affect the respiratory function in patients who survived CDH repair.

Adolescent↗
PubMed2004

Synthesis and binding properties of novel selective 5-HT3 receptor ligands.

This work reports on the synthesis and affinities for the 5-HT(3) versus the 5-HT(4) receptor of new piperazinyl-substituted thienopyrimidine derivatives 20-45 with a view to identify potent and selective ligands for the 5-HT(3) receptor. Some of the new compounds show good affinity for the 5-HT(3) receptor and, notably, do not display any affinity for the 5-HT(4) receptor. 4-(4-Methyl-1-piperazinyl)-2-methylthio-6,7-dihydro-5H-cyclopenta[4,5]thieno[2,3-d]pyrimidine 31 exhibits the highest affinity for the 5-HT(3) receptor (Ki = 33 nM) and behaves as noncompetitive antagonist.

Animals↗
PubMed2004

Immunohistology of aquaporin-1 and stem cell factor-receptor in human undescended testes.

OBJECTIVES: Both aquaporin (AQP) 1 and the stem-cell factor/C-kit system seem to have a definite role in testis function, but very few studies have been reported in humans, especially in the paediatric age group. With the present study we wanted to investigate the expression of these proteins to better delineate their role in normal and pathologic testes. METHODS: Immunohistology using AQP 1 and C-kit antibodies was performed on paraffin sections of open-testicular biopsies from 32 undescended testes. The testes of cryptorchid patients, with ages ranging from 2 to 15 years, were biopsied during an orchidopexy operation, after obtaining informed consent. Control biopsies, from 8 patients of matched age, were obtained during operations for inguinal hernia or hydrocele, always after obtaining informed consent. Positive results were recorded as diffuse or focal patterns and scored as weak, moderate or strong immunostaining. RESULTS: AQP 1 antibody strongly depicted microvessel endothelial cells, but was unlabeled in endotubular and interstitial cell lines, in both control and undescended testes. The C-kit immunostaining in normal testes revealed a diffuse, strong staining in the cytoplasm of spermatogonia and primary spermatocytes. However, in the undescended testes a focal C-kit immunolabelling was weakly recognized in both spermatogonial and immature Sertoli cells. CONCLUSIONS: These results indicate a direct involvement of AQP 1 in the regulation of fluid transport across the endothelial cell membranes of testicular microvessels. A role of the C-kit receptor protein is also substantiated by its strong expression in the maturing spermatogonia of the normal testes, but was minimally or not recognizable in undescended prepubertal testes.

Adolescent↗
PubMed2003

New pyrimido[5,4-b]indoles as ligands for alpha(1)-adrenoceptor subtypes.

A new series of compounds were designed as structural analogues of the alpha(1)-AR ligand RN5 (4), characterized by a tricyclic 5H-pyrimido[5,4-b]indole-(1H,3H)2,4-dione system connected through an alkyl chain to a phenylpiperazine (PP) moiety. These compounds were synthesized and tested in binding assays on human alpha(1A)-AR, alpha(1B)-AR, and alpha(1D)-AR subtypes expressed in HEK293 cells. Several structural modifications were performed on the PP moiety, the tricyclic system, and the connecting alkyl chain. Many of the new molecules showed a preferential affinity for the alpha(1D)-AR subtype. Some compounds, including 39 and 40, displayed substantial alpha(1D)-AR selectivity with respect to alpha(1A)-AR, alpha(1B)-AR, serotonergic 5-HT(1A), 5-HT(1B), 5-HT(2A), and dopaminergic D(1) and D(2) receptors. Two conformationally rigid analogues of 4, useful for studying the architecture of the receptor/ligand complex, were also prepared and tested. A subset of the new compounds was then used to evolve a preliminary pharmacophore model for alpha(1D)-AR antagonists, based on a more generalized model we had developed for alpha(1)-AR antagonists. This new model rationalized the relationships between structural properties and biological data of the pyrimido[5,4-b]indole compounds, as well as other compounds.

Adrenergic alpha-Antagonists↗
PubMed2003

Diagnostic and technical approach to esthetic rehabilitations.

The success of an esthetic rehabilitation depends on the understanding of the patient's needs and on effective communication among the entire dental team. The involvement of the dental technician since the beginning of the treatment plan is one of the keys for success. This article describes a systematic approach to oral rehabilitations involving esthetic areas. Technical suggestions for the construction of the diagnostic wax-up, the provisional, and the final ceramic restorations are illustrated in a logical sequence.

Crowns↗
PubMed2002

[11C]RN5: a new agent for the in vivo imaging of myocardial alpha1-adrenoceptors.

The radiolabelling with the positron-emitter Carbon-11 and the biological evaluation in rats of 3-[2-[4-(2-[11C]methoxyphenyl)piperazin-1-yl]ethyl]pyrimido[5,4-b]indole-2,4-dione ([11C]RN5), alpha1-adrenoceptor antagonist (K(i)=0.21 nM), as a putative radioligand for the non-invasive assessment of alpha1-adrenoceptors with positron emission tomography (PET) is reported. The radiosynthesis procedure consisted of O-methylation of des-methyl precursor with [11C]methyl iodide in the presence of potassium hydroxide in dimethylformamide (DMF) at 80 degrees C. [11C]RN5 was obtained in >99% radiochemical purity in 25 min with a radiochemical yield in the 20-30% range, end of synthesis (EOS) (non-decay corrected) and a specific radioactivity of 92.5+/-18.5 GBq/micromol. Pre-clinical studies in rats showed a high uptake of [11C]RN5 in heart, spleen, adrenal gland, lung and kidney but not in the brain. Inhibition studies with high doses of different adrenergic antagonists indicate that more than 70% of myocardial uptake of [11C]RN5 is due to specific binding to alpha1-adrenoceptors. Our results indicate that [11C]RN5 is suitable to be further developed as a potential radioligand for the in vivo PET imaging of myocardial alpha1-adrenoceptors in humans.

Adrenergic alpha-Antagonists↗
PubMed2002

[1,2,4]Triazole derivatives as 5-HT(1A) serotonin receptor ligands.

A series of new 4-amino-3-[3-[4-(2-methoxy or nitro phenyl)-1-piperazinyl] propyl]thio]-5-(substitutedphenyl)[1,2,4]triazoles 11a-t was synthesized in order to obtain compounds with high affinity and selectivity for 5-HT(1A) receptor over the alpha(1)-adrenoceptor. A series of isomeric 4-amino-2-[3-[4-(2-methoxy or nitro phenyl)-1-piperazinyl]propyl]-5-(substitutedphenyl)-2,4-dihydro-3H[1,2,4]triazole-3-thiones 12a-r was also isolated and characterized. New compounds were tested to evaluate their affinity for 5-HT(1A) receptor and alpha(1)-adrenoceptor in radioligand binding experiments. As a general trend, triazoles 11a-t showed a preferential affinity for the 5-HT(1A) receptor whereas isomeric 2,4-dihydro-3H[1,2,4]triazole-3-thiones 12a-r preferentially bind to the alpha(1)-adrenoceptor site. Several molecules showed affinities in the nanomolar range and 4-amino-3-[3-[4-(2-methoxyphenyl)-1-piperazinyl]propyl]thio]-5-(4-propyloxy-phenyl)[1,2,4]triazole (11o) was the most selective derivative for the 5-HT(1A) receptor (K(i) alpha(1)/K(i) 5-HT(1A)=55). The decrease in 5-HT(1A) receptor selectivity in 3-[3-[4-(2-methoxyphenyl)-1-piperazinyl]propyl]thio]-5-(substitutedphenyl)[1,2,4] triazole 14a-b, lacking in the amino group in 4-position of the triazole ring, in comparison with their analogues in the series 11a-t, suggest that the amino function represents a critical structural feature in determining 5-HT(1A) receptor selectivity in this class of compounds.

Animals↗