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1.
J Appl Microbiol ; 126(6): 1785-1796, 2019 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-30953595

RESUMEN

AIMS: This study reports the results of the application of a new agar-gauze biogel system activated with viable bacterial cells to altered wall paintings. METHODS AND RESULTS: Biocleaning using agar biogel and agar-gauze biogel systems was performed onsite by direct application to altered wall painting surfaces (25-1000 cm2 ). The treatments were performed for the restoration of two original Italian sites: (i) at the Vatican Museums, Cristo che salva Pietro dalle acque-La Navicella, a wall painting by Giovanni Lanfranco (1627-1628) and (ii) at Pisa Cathedral Cupola, Incarnato, a wall painting by Orazio Riminaldi (1593-1630) and his brother Girolamo Riminaldi. The novelty of this study is the use of viable Pseudomonas stutzeri A29 cells in an advanced agar-gauze biogel system and the short bio-application contact times of between 3 and 12 h. The historical artworks were altered by lipid and protein residues from past restoration, as confirmed by Py-gas chromatography-mass spectrometry and FT-IR data. The effectiveness of the biological treatment was assessed, and general considerations were discussed. CONCLUSIONS: The short bio-application contact time of advanced agar-gauze gel activated with viable P. stutzeri cells makes this biotechnology promising as an alternative method to the traditional onsite cleaning techniques currently in use for altered historical wall paintings. SIGNIFICANCE AND IMPACT OF THE STUDY: In this study, we report for the first time the biocleaning of altered materials located in vertical and vaulted areas using agar-gauze biogel with short application times. These findings are of great significance for future restoration activities and are crucial for determining the best preservation strategies in this field.


Asunto(s)
Biotecnología/métodos , Contaminantes Ambientales/metabolismo , Pinturas , Pseudomonas stutzeri/metabolismo , Agar , Vendajes , Biodegradación Ambiental , Cromatografía de Gases y Espectrometría de Masas , Italia , Espectroscopía Infrarroja por Transformada de Fourier
2.
Lett Appl Microbiol ; 68(2): 120-127, 2019 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-30408202

RESUMEN

Conditions of the acrylic resin (AR) surface, such as roughness, can promote a favourable environment for the adhesion of micro-organisms, even on the surface of ocular prostheses. This study evaluated the influence of photopolymerized glaze application on the roughness of ARs and adhesion of Staphylococcus aureus and Staphylococcus epidermidis on ocular AR surfaces submitted to accelerated ageing. Two hundred and eighty-eight samples of white colour (N1) and colourless ARs were distributed in eight groups (n = 9), based on surface treatments (glaze or ARs submitted to only a final polishing), accelerated ageing (before and after) and periods of microbial growth (24- and 48-h). The roughness average (Ra) and total height of roughness profile (Rt) values were greater for the groups with glaze and increased for all groups after ageing. The microbial adhesion among the groups with and without glaze did not present a statistically significant difference. The ageing did not statistically affect the adhesion of Staph. epidermidis, but affected the adhesion of Staph. aureus, which presented an increase after 24 h of growth on only N1 AR with glaze. These results demonstrate that the glaze did not contribute to adhesion of Staph. aureus and Staph. epidermidis, which are responsible for most ocular prosthetic infections. SIGNIFICANCE AND IMPACT OF THE STUDY: Some recent evidence suggested that the surface finish of ocular prostheses influences the accumulation of deposits that can affect the interaction with pathogenic bacteria, increasing the probability of infections. In addition, surface deterioration over time can increase the roughness and, consequently, biofilm formation. Thus, a better understanding of the influence of surface finish on bacterial adhesion becomes extremely important. In this study, we tested a glaze for surface polishing compared to mechanical polishing, before and after ageing. The results suggest that the glaze did not contribute to microbial adhesion and might be useful in preventing possible prosthetic infections.


Asunto(s)
Resinas Acrílicas/química , Adhesión Bacteriana/fisiología , Ojo Artificial/microbiología , Staphylococcus aureus/metabolismo , Staphylococcus epidermidis/metabolismo , Propiedades de Superficie
3.
J Appl Microbiol ; 125(3): 800-812, 2018 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-29754410

RESUMEN

AIMS: In this work, the 'hi-tech' complex biocleaning and restoration of the 14th-century fresco Triumph of Death (5·6 × 15·0 m) at the Camposanto Monumental Cemetery (Pisa, Italy) is reported. Since 2000, the restoration based on the biological cleaning of noble medieval frescoes, has been successfully utilized in this site. METHODS AND RESULTS: The novelty of this study is the two-steps biocleaning process using Pseudomonas stutzeri A29 viable cells, previously applied for recovering other valuable frescoes. In this case, after the fresco detachment from the asbestos-cement support (eternity), both the animal glue and the residues of calcium caseinate were biologically removed respectively from the front and from the back of the fresco in 3 h as indicated by GC-MS and PY/GC-MS analyses. The data obtained during the monitoring of the biorestoration process confirmed that the adopted procedure does not leave residual cells on the fresco surfaces as showed by plate count method, ATP determination and also SEM observation. In addition, to avoid the risk of condensation phenomena after the relocation of the restored fresco sections onto the original walls, the use of a new support has been set up together with the design of a control system that allows a continuous monitoring of environmental parameters for prevention and conservation purposes. CONCLUSIONS: This large-scale biorestoration work clearly shows and confirms that this biotechnology is highly efficient, safe, noninvasive, risk-free and very competitive compared to the traditional cleaning methods, offering an unusual 'resurrection' of the degraded artworks also in very complicated and delicate conditions such as the Triumph of Death fresco, defined for its dimension and artistic importance the 'Pisa's Sistina frescoes'. SIGNIFICANCE AND IMPACT OF THE STUDY: These findings can be of significant importance for other future new restoration activities and they are crucial for determining preservation strategies in this field.


Asunto(s)
Biotecnología/métodos , Pinturas , Adhesivos , Caseínas , Cementerios , Cromatografía de Gases y Espectrometría de Masas , Italia , Pseudomonas stutzeri/fisiología
4.
Ann Oncol ; 25(1): 57-63, 2014 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-24276029

RESUMEN

BACKGROUND: Risk-reducing mastectomy (RRM) decreases breast cancer (BC) risk in BRCA1/2 mutation carriers by up to 95%, but the Italian attitude towards this procedure is reluctant. PATIENTS AND METHODS: This is an observational study with retrospective design, using quantitative and qualitative research methods, aimed at evaluating the attitude towards RRM by rapid genetic counselling and testing (RGCT), at the time of BC diagnosis, compared with traditional genetic counselling and testing (TGCT), after previous BC surgery. Secondary aims were to investigate patient satisfaction after RRM and the rate of occult tumour in healthy breasts. A total of 1168 patients were evaluated: 1058 received TGCT, whereas 110 underwent RGCT. RESULTS: In TGCT, among 1058 patients, 209 (19.7%) mutation carriers were identified, with the rate of RRM being 4.7% (10 of 209). Conversely in RGCT, among 110 patients, 36 resulted positive, of which, 15 (41.7%) underwent bilateral mastectomy at the BC surgery time, showing an overall good satisfaction, measured by interpretative phenomenological analysis 12 months after the intervention. CONCLUSIONS: Our study shows that RGCT in patients with a hereditary profile is associated with a high rate of RRM at the BC surgery time, this being the pathway offered within a multidisciplinary organization.


Asunto(s)
Neoplasias de la Mama/genética , Genes BRCA1 , Genes BRCA2 , Asesoramiento Genético , Pruebas Genéticas , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Neoplasias de la Mama/diagnóstico , Neoplasias de la Mama/cirugía , Femenino , Humanos , Italia , Mastectomía , Persona de Mediana Edad , Estudios Retrospectivos , Resultado del Tratamiento , Adulto Joven
5.
G Chir ; 35(5-6): 129-33, 2014.
Artículo en Inglés | MEDLINE | ID: mdl-24979104

RESUMEN

The GISTs are rare tumours but even rarer is the localization in some districts. We reported two GISTs of the duodenum, two of the omentum and peritoneum, one of the rectum and one of a Meckel's diverticulum. These exceptional locations are confirmed by the relative difficult diagnosis, obtained in some cases only by the surgical treatment despite the CT and MR. The endoscopy is useful in hemorrhagic and duodenum forms, only for the diagnosis and for the control of blood loss. Surgical treatment in all cases was decisive without the need to make use of adjuvant therapy, with positive long-term results, which excluded the disappearance of relapses or secondary lesions.


Asunto(s)
Neoplasias Gastrointestinales/diagnóstico , Neoplasias Gastrointestinales/cirugía , Tumores del Estroma Gastrointestinal/diagnóstico , Tumores del Estroma Gastrointestinal/cirugía , Adulto , Anciano , Anciano de 80 o más Años , Neoplasias Duodenales/diagnóstico , Neoplasias Duodenales/cirugía , Femenino , Humanos , Neoplasias del Íleon/diagnóstico , Neoplasias del Íleon/cirugía , Masculino , Divertículo Ileal/diagnóstico , Divertículo Ileal/cirugía , Persona de Mediana Edad , Epiplón/patología , Epiplón/cirugía , Neoplasias Peritoneales/diagnóstico , Neoplasias Peritoneales/cirugía , Neoplasias del Recto/diagnóstico , Neoplasias del Recto/cirugía , Resultado del Tratamiento
6.
Clin Ter ; 174(1): 23-27, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-36655640

RESUMEN

Introduction: This study aimed to evaluate the antibiofilm effect of different agents (neutral soap, 4% chlorhexidine, Efferdent effervescent tablets, 1% triclosan, and citronella essential oil) used for ocular prosthesis cleaning. Material and Methods: Biofilms of S. aureus and S. epidermidis were formed on 60 ocular prosthesis acrylic resin specimens. The specimens were cleaned with the studied agents with different techniques. Microorganism counting was performed. Data were submitted to ANOVA and HSD Tukey-Kramer (p<.01). Results: When compared to the control group, all cleaning protocols promoted a reduction in growth of microorganisms. The 4% chlorhexidine, effervescent tablets, and 1% triclosan cleaning agents eliminated biofilm in all groups. Conclusion: Therefore, immersion in 4% chlorhexidine, effervescent tablets, and 1% triclosan could be the best protocols indicated for ocular prosthesis cleaning due to their ability to eliminate biofilm.


Asunto(s)
Clorhexidina , Triclosán , Humanos , Clorhexidina/farmacología , Ojo Artificial , Staphylococcus aureus , Triclosán/farmacología , Biopelículas , Comprimidos/farmacología
7.
ESMO Open ; 6(2): 100055, 2021 04.
Artículo en Inglés | MEDLINE | ID: mdl-33582382

RESUMEN

INTRODUCTION: The present analysis aims to evaluate the consequences of a 2-month interruption of mammographic screening on breast cancer (BC) stage at diagnosis and upfront treatments in a region of Northern Italy highly affected by the severe acute respiratory syndrome-related coronavirus-2 (SARS-CoV-2) virus. METHODS: This retrospective single-institution analysis compared the clinical pathological characteristics of BC diagnosed between May 2020 and July 2020, after a 2-month screening interruption, with BC diagnosed in the same trimester of 2019 when mammographic screening was regularly carried out. RESULTS: The 2-month stop in mammographic screening produced a significant decrease in in situ BC diagnosis (-10.4%) and an increase in node-positive (+11.2%) and stage III BC (+10.3%). A major impact was on the subgroup of patients with BC at high proliferation rates. Among these, the rate of node-positive BC increased by 18.5% and stage III by 11.4%. In the subgroup of patients with low proliferation rates, a 9.3% increase in stage III tumors was observed, although node-positive tumors remained stable. Despite screening interruption, procedures to establish a definitive diagnosis and treatment start were subsequently carried out without delay. CONCLUSION: Our data showed an increase in node-positive and stage III BC after a 2-month stop in BC screening. These findings support recommendations for a quick restoration of BC screening at full capacity, with adequate prioritization strategies to mitigate harm and meet infection prevention requirements.


Asunto(s)
Neoplasias de la Mama/diagnóstico por imagen , Neoplasias de la Mama/patología , Neoplasias de la Mama/terapia , COVID-19 , Tamizaje Masivo/organización & administración , Anciano , Neoplasias de la Mama/epidemiología , Neoplasias de la Mama Masculina/diagnóstico por imagen , Femenino , Humanos , Italia/epidemiología , Metástasis Linfática/diagnóstico por imagen , Masculino , Mamografía/estadística & datos numéricos , Mastectomía , Persona de Mediana Edad , Terapia Neoadyuvante , Estudios Retrospectivos , Factores de Tiempo
8.
Science ; 262(5142): 2005-9, 1993 Dec 24.
Artículo en Inglés | MEDLINE | ID: mdl-8266096

RESUMEN

Intermolecular multiple-quantum coherences between bulk water and a glycoprotein fragment at modest concentration (20 mM) have been experimentally produced and detected, although such coherences are inconceivable in the normal theoretical framework of nuclear magnetic resonance. A density matrix treatment explains these results by including the long-range dipolar interaction between spins and by discarding the high-temperature approximation. These results imply that peak intensities (critical for structural determinations) can be distorted in many gradient experiments, and show that magic-angle gradients provide substantial improvements with reduced gradient strengths. They also suggest methods for contrast enhancement in magnetic resonance imaging.


Asunto(s)
Fibronectinas/química , Espectroscopía de Resonancia Magnética , Agua/química , Modelos Químicos , Fragmentos de Péptidos/química , Soluciones
9.
Minerva Chir ; 62(3): 191-6, 2007 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-17519845

RESUMEN

Hiatal hernias are classified into 3 types: sliding hernia (type I), paraesophageal hernia (type II) and mixed hernia (type III), that is a combination of type I and II. The paraesophageal and mixed hernias represent about 5-10% of the surgically treated hiatal hernias. The surgical treatment of the paraesophageal and mixed hernias is unavoidable because of the high risk of severe complications and it has to be considered in a high percentage of cases. The most important technical difficulty in the video-laparoscopic treatment is represented by the hugeness of the hernial defect and by the challenging reduction of the stomach into the abdomen. A cautious dissection of hernial sac and diaphragmatic cruses as well as a careful crural repair make the video-laparoscopic procedure feasible. The operative times are not prolonged and the results are similar to the open technique ones. In literature, the incidence of both intra and postoperative complications doesn't exhibit statistically significant differences between laparoscopic and open techniques. Because of the complexity of the laparoscopic procedure, the minimally invasive access has to be reserved to surgeons who are well trained in those techniques. In this paper we describe 2 cases: one of paraesophageal hernia and the other of mixed hernia which were video-laparoscopically treated with the help, in the second case, of a Gore-Tex mesh. In both cases the technical results were positive. Intra and postoperative complications didn't occur and, one year after the surgical procedure, both patients were in good health and recurrence-free.


Asunto(s)
Hernia Diafragmática/cirugía , Hernia Hiatal/cirugía , Laparoscopía , Anciano , Femenino , Humanos , Masculino , Persona de Mediana Edad
10.
Eur J Surg Oncol ; 43(4): 613-618, 2017 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-27793416

RESUMEN

BACKGROUND: The optimal time interval between the end of neoadjuvant systemic therapy (NST) and breast surgery is still unclear. It is not known if a delay in surgery might influence the benefit of primary chemotherapy. The aim of this study is to evaluate the relationship between time to surgery (TTS) and survival outcomes. PATIENTS AND METHODS: According to TTS, women with diagnosis of BC treated with NST were divided into two cohorts: group A = 21 days or fewer and group B = longer than 21 days. OS and RFS were estimated and compared according to TTS and known prognostic factors. RESULTS: A total of 319 patients were included in the study: 61 in group A and 258 in group B. Median TTS was 34 days. No association between clinical stage, nuclear grade, type of chemotherapy, type of surgery and TTS was detected. OS and RFS were significantly worse for group B compared with group A, with a hazard ratio of 3.1 (95% CI, 1.1-8.6 p = 0.03) and 3.1 (95% CI, 1.3-7.1 p = 0.008) respectively. Multivariate analysis confirmed that TTS was an independent prognostic factor in term of OS (p = 0.03) and RFS (p = 0.01). Even in the subgroup of patients with pCR, TTS continued to be an independent prognostic factor for both OS and RFS (p = 0.05 and p = 0.03). CONCLUSIONS: TTS after NST seems to influence survival outcomes. BC patients underwent surgery within 21 days experienced maximal benefit from previous treatment: this advantage is consistent and maintained over time.


Asunto(s)
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , Neoplasias de la Mama/cirugía , Mastectomía Segmentaria/métodos , Terapia Neoadyuvante , Tiempo de Tratamiento/estadística & datos numéricos , Adulto , Anciano , Anciano de 80 o más Años , Antraciclinas/administración & dosificación , Axila , Neoplasias de la Mama/mortalidad , Neoplasias de la Mama/patología , Quimioterapia Adyuvante , Estudios de Cohortes , Supervivencia sin Enfermedad , Femenino , Humanos , Escisión del Ganglio Linfático/métodos , Mastectomía/métodos , Persona de Mediana Edad , Análisis Multivariante , Clasificación del Tumor , Estadificación de Neoplasias , Pronóstico , Modelos de Riesgos Proporcionales , Radioterapia Adyuvante , Estudios Retrospectivos , Tasa de Supervivencia , Taxoides/administración & dosificación , Factores de Tiempo
11.
J Mol Biol ; 302(3): 607-23, 2000 Sep 22.
Artículo en Inglés | MEDLINE | ID: mdl-10986122

RESUMEN

Interleukin-2 tyrosine kinase (Itk), is a T-cell specific tyrosine kinase of the Tec family. We have examined a novel intermolecular interaction between the SH3 and SH2 domains of Itk. In addition to the interaction between the isolated domains, we have found that the dual SH3/SH2 domain-containing fragment of Itk self-associates in a specific manner in solution. Tec family members contain the SH3, SH2 and catalytic domains common to many kinase families but are distinguished by a unique amino-terminal sequence, which contains a proline-rich stretch. Previous work has identified an intramolecular regulatory association between the proline-rich region and the adjacent SH3 domain of Itk. The intermolecular interaction between the SH3 and SH2 domains of Itk that we describe provides a possible mechanism for displacement of this intramolecular regulatory sequence, a step that may be required for full Tec kinase activation. Additionally, localization of the interacting surfaces on both the SH3 and SH2 domains by chemical shift mapping has provided information about the molecular details of this recognition event. The interaction involves the conserved aromatic binding pocket of the SH3 domain and a newly defined binding surface on the SH2 domain. The interacting residues on the SH2 domain do not conform to the consensus motif for an SH3 proline-rich ligand. Interestingly, we note a striking correlation between the SH2 residues that mediate this interaction and those residues that, when mutated in the Tec family member Btk, cause the hereditary immune disorder, X-linked agamaglobulinemia.


Asunto(s)
Proteínas Tirosina Quinasas/química , Proteínas Tirosina Quinasas/metabolismo , Dominios Homologos src , Secuencias de Aminoácidos , Secuencia de Aminoácidos , Sitios de Unión , Dominio Catalítico , Secuencia Conservada , Difusión , Activación Enzimática , Ligandos , Modelos Moleculares , Datos de Secuencia Molecular , Resonancia Magnética Nuclear Biomolecular , Fragmentos de Péptidos/química , Fragmentos de Péptidos/metabolismo , Unión Proteica , Estructura Secundaria de Proteína , Proteínas Tirosina Quinasas/genética , Alineación de Secuencia , Especificidad por Sustrato , Ultracentrifugación
12.
J Clin Endocrinol Metab ; 80(3): 841-5, 1995 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-7883840

RESUMEN

Cabergoline (CAB) a long-acting dopaminergic ergoline derivative, was given orally, in single doses of 0.5, 1.0, and 1.5 mg, to 12 healthy men in order to evaluate its PRL-lowering effect as well as its plasma pharmacokinetics and urinary excretion. Drug administrations were separated by 5-week washout periods. Blood samples for PRL and CAB determination were taken at baseline and for 840 h thereafter (every 1 h up to 4 h, every 4 h up to 12 h, every 24 h up to 168 h, and weekly up to 5 weeks). Fractional urine collections for CAB excretion were taken immediately before drug administration, every 4 h up to 12 h, and every 12 h up to 168 h. During the study period, blood pressure and heart rate were monitored at the same time periods of plasma sampling for CAB, and electrocardiographic tracings and hematological evaluations were performed before and after each treatment period. All CAB doses (0.5, 1.0, and 1.5 mg) produced in all subjects a complete PRL suppression (PRL < 1.0 micrograms/L), that occurred earlier and persisted longer with the two higher doses. PRL secretion areas [area under the curve (AUC) 0-48 h and 48-840 h] were higher after 0.5-mg than after 1.0- and 1.5-mg doses. In particular, in the first portion of the area, the difference between 0.5 mg and both 1.0 and 1.5 mg was highly statistically significant (P < 0.01) without significant differences between the two highest doses. Mean CAB maximal plasma concentrations (Cmax) were 33.3 +/- 3.69, 40.3 +/- 2.49, and 67.0 +/- 9.79 ng/L after 0.5, 1.0, and 1.5 mg CAB, respectively; time to Cmax was 2 h (median) for all doses; CAB AUC(0-168 h) after 0.5 mg CAB was significantly lower (P < 0.01) than after 1.5 mg CAB. The percentages of the administered doses of CAB excreted in urine were 1.1 +/- 0.1%, 1.1 +/- 0.1%, and 1.2 +/- 0.1% for the 0.5-, 1.0-, and 1.5 mg doses, respectively (P = NS). CAB AUCs(0-168 h) and Cmax normalized to the 1.0-mg dose were compared by two-way analysis of variance; no significant differences were found for CAB AUCs(0-168h); Cmax after 0.5 mg was significantly higher (P < 0.01) than after 1.0 and 1.5 mg CAB. A progressive decrease of systolic and diastolic blood pressure was observed, and symptomatic hypotension after the 1.0-mg dose did not allow one subject to receive the 1.5-mg dose. Other mild to moderate adverse events occurred only after 1.0 and 1.5 mg CAB. These results indicate that, in the dose range of 0.5-1.5 mg, the pharmacokinetics of CAB are dose independent, and that the pharmacodynamic data and the frequencies of adverse events of CAB are dose related, with no significant differences in the PRL-lowering effect of the 1.0- and 1.5-mg doses.


Asunto(s)
Antineoplásicos/farmacocinética , Agonistas de Dopamina/farmacocinética , Ergolinas/farmacocinética , Prolactina/sangre , Adulto , Cabergolina , Relación Dosis-Respuesta a Droga , Ergolinas/efectos adversos , Ergolinas/farmacología , Humanos , Masculino
13.
J Clin Endocrinol Metab ; 80(11): 3279-83, 1995 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-7593438

RESUMEN

In acromegaly, high GH levels are primarily attributable to GH hypersecretion, but the contribution of GH clearance is still under debate and is difficult to assess. In the present study, GH plasma clearance rate (PCR), half-life (t1/2), and volume of distribution (VD) were assessed in seven acromegalic patients and seven normal lean subjects, after suppression of endogenous GH release by octreotide, with use of a constant GH infusion. An octreotide sc infusion was started the night before the day of the test (2100 h) and maintained throughout the study. On the day of the test, exogenous GH was constantly infused iv for 6 h (0900-1500 h) in order to achieve a new steady state of GH levels. After the cessation of GH infusion, the decay curve of serum GH levels was monitored for 1 h. In both groups, GH PCR was calculated from the steady state serum GH levels, and GH t1/2 was estimated from the monoexponential analysis of the GH disappearance curve. Estimates of VD were derived from PCR and t1/2. In acromegalic patients, GH PCR was 2.5 +/- 0.2 mL/kg.min-1, and GH t1/2 and VD were 15.7 +/- 1.0 min and 54.9 +/- 5.5 mL/kg, respectively. GH PCR and GH t1/2 of acromegalic patients were higher and lower, respectively, than those of normal subjects (PCR, 1.7 +/- 0.2 mL/kg.min-1, P < 0.02; t1/2, 18.4 +/- 0.6 min, P < 0.05). VD was not significantly different in the two groups. In summary, in acromegalic patients GH kinetic parameters can be reliably assessed by using a constant GH infusion after suppression of endogenous GH release by octreotide. Our results also indicate that the increased circulating GH levels observed in acromegaly are attributable only to GH overproduction and do not depend on an alteration in the processes of GH distribution or disappearance.


Asunto(s)
Acromegalia/sangre , Hormona del Crecimiento/sangre , Octreótido , Adulto , Femenino , Hormona del Crecimiento/farmacocinética , Semivida , Humanos , Inyecciones Subcutáneas , Masculino , Valores de Referencia , Distribución Tisular
14.
J Clin Endocrinol Metab ; 82(7): 2239-43, 1997 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-9215300

RESUMEN

It has been previously reported that in healthy subjects, the acute reduction of free fatty acids (FFA) levels by acipimox enhances the GH response to GHRH. In the present study, the GH response to GHRH was evaluated during acute blockade of lipolysis obtained either by acipimox or by insulin at different infusion rates. Six healthy subjects (four men and two women, 25.8 +/- 1.9 yrs old, mean +/- SE) underwent three GHRH tests (50 micrograms iv, at 1300 h) during: 1) iv 0.9% NaCl infusion (1200-1500 h) after oral acipimox administration (250 mg) at 0700 h and at 1100 h; 2) 0.1 mU.kg-1.min-1 euglycemic insulin clamp (1200-1500 h) after oral acipimox administration (250 mg at 0700 h and at 1100 h); 3) 0.4 mU.kg-1.min-1 euglycemic insulin clamp (1200-1500 h) after oral placebo administration (at 0700 and 1100 h). Serum insulin (immunoreactive insulin) levels were significantly different in the three tests (12 +/- 2, 100 +/- 10, 194 +/- 19 pmol/L, P < 0.06), plasma FFA were low and similar (0.04 +/- 0.003, 0.02 +/- 0.005, 0.02 +/- 0.003, not significant), and the GH response to GHRH was progressively lower (4871 +/- 1286, 2414 +/- 626, 1076 +/- 207 micrograms/L 120 min), although only test 3 was significantly different from test 1 (P < 0.05). Pooling the three tests together, a significant negative regression was observed between mean serum immunoreactive insulin levels and the GH response to GHRH (r = -0.629, P < 0.01). Our results indicate that in healthy subjects, acipimox and hyperinsulinemia produce a similar decrease in FFA levels and that at similar low FFA, the GH response to GHRH is lower during insulin infusion than after acipimox. These data suggest that insulin exerts a negative effect on GH release. Because the insulin levels able to reduce the GH response to GHRH are commonly observed during the day, for instance during the postprandial period, we conclude that the insulin negative effect on GH release may have physiological relevance.


Asunto(s)
Hormona Liberadora de Hormona del Crecimiento/farmacología , Hormona del Crecimiento/sangre , Insulina/sangre , Adulto , Estudios Cruzados , Ácidos Grasos no Esterificados/sangre , Femenino , Glicerol/sangre , Humanos , Hipolipemiantes/farmacología , Masculino , Pirazinas/farmacología , Método Simple Ciego , Factores de Tiempo
15.
Metabolism ; 42(10): 1242-8, 1993 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-8105365

RESUMEN

Insulin inhibits its own release (autofeedback), and growth hormone (GH) inhibits the GH response to a variety of stimuli. The aim of this study was to evaluate whether glucagon (G) can modify pancreatic G (IRG) release in humans. Seven healthy men received intravenous (i.v.) arginine (30 g in 30 minutes) 240 minutes after the beginning of a 0.9% NaCI saline infusion and a 2.5-, 4.0-, and 8.0-ng/kg.min-1 porcine G infusion, with each infusion lasting 360 minutes. All G infusions yielded stable and dose-related plasma IRG levels, and the 4.0- and 8.0-ng/kg.min-1 G infusions decreased plasma free fatty acids (FFA) and blood glycerol and beta-OH-butyrate levels and elicited insulin (IRI) release, and the 8.0-ng/kg.min-1 G infusion elicited GH release and increased blood glucose (BG) levels; somatostatin (SRIF) levels were not affected by G infusions. At 240 minutes, plasma IRG levels were higher during G infusion than during saline infusion, whereas serum IRI and BG levels had returned to preinfusion levels. At this point, G infusions decreased the integrated (240 to 300 minutes) IRG, IRI, BG, and SRIF responses, but not the GH response to arginine. These data indicate that prolonged G infusions decrease the IRG response to arginine; in addition, G decreases plasma FFA levels, and higher G doses stimulate IRI release and exert a self-limited hyperglycemic effect. The fact that the IRI response to arginine was decreased by G could be due to a refractoriness of beta cells to subsequent stimuli; the decreased SRIF response to arginine is likely due to G itself or to a decrease of plasma FFA levels.


Asunto(s)
Arginina/farmacología , Glucagón/sangre , Glucagón/farmacología , Insulina/sangre , Somatostatina/sangre , Ácido 3-Hidroxibutírico , Adulto , Arginina/administración & dosificación , Glucemia/análisis , Glucemia/metabolismo , Relación Dosis-Respuesta a Droga , Ácidos Grasos no Esterificados/sangre , Ácidos Grasos no Esterificados/metabolismo , Retroalimentación/fisiología , Glucagón/administración & dosificación , Glicerol/sangre , Glicerol/metabolismo , Hormona del Crecimiento/sangre , Hormona del Crecimiento/metabolismo , Humanos , Hidroxibutiratos/sangre , Infusiones Intravenosas , Insulina/metabolismo , Masculino , Radioinmunoensayo , Somatostatina/metabolismo , Factores de Tiempo
16.
Metabolism ; 43(10): 1207-13, 1994 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-7934970

RESUMEN

Obesity is associated with blunted growth hormone (GH) levels and pulsatility and elevated plasma free fatty acids (FFA) levels. To evaluate whether the two phenomena are correlated, in the present study we investigated the effects of an acute pharmacologic blockade of lipolysis on nocturnal GH levels and pulsatility in 10 obese and 10 control subjects. At 9 PM on two different nights with a 1-night interval in between, all subjects received either a single oral tablet of placebo or acipimox slow release (ACX-SR, 500 mg) in randomized order. Blood samples were drawn from 10 PM to 6 AM for evaluation of FFA, glycerol, GH, immunoreactive insulin (IRI), glucose, and insulin-like growth factor-I (IGF-I) levels. After placebo, FFA and glycerol levels were higher (P < .02) and GH levels, areas, peak amplitude, and peak increment (assessed by the Cluster algorithm) were lower in obese than in control subjects (P < .01). After ACX-SR, FFA and glycerol levels were reduced in both groups (P < .02 v placebo), and in obese subjects they became similar to those observed in control subjects after placebo. ACX-SR had no effect on GH levels and pulsatility in control subjects. GH levels, areas, peak, amplitude, peak increment, and interpeak valley levels were all increased after ACX-SR in obese subjects (P < .05 or less v placebo) and became similar to those observed in normal subjects after placebo, but no correlation was found between the reduction in FFA levels and the increase in GH levels and pulsatility.(ABSTRACT TRUNCATED AT 250 WORDS)


Asunto(s)
Hormona del Crecimiento/sangre , Hipolipemiantes/farmacología , Lipólisis/efectos de los fármacos , Obesidad/metabolismo , Pirazinas/farmacología , Administración Oral , Adulto , Glucemia/análisis , Índice de Masa Corporal , Ritmo Circadiano , Estudios Cruzados , Preparaciones de Acción Retardada , Método Doble Ciego , Ácidos Grasos no Esterificados/sangre , Femenino , Glicerol/sangre , Humanos , Hipolipemiantes/uso terapéutico , Insulina/sangre , Factor I del Crecimiento Similar a la Insulina/análisis , Masculino , Persona de Mediana Edad , Obesidad/tratamiento farmacológico , Flujo Pulsátil , Pirazinas/uso terapéutico
17.
Metabolism ; 48(9): 1152-6, 1999 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-10484056

RESUMEN

We have recently presented experimental evidence indicating that insulin has a physiologic inhibitory effect on growth hormone (GH) release in healthy humans. The aim of the present study was to determine whether in obesity, which is characterized by hyperinsulinemia and blunted GH release, insulin contributes to the GH defect. To this aim, we used a simplified experimental protocol previously used in healthy humans to isolate the effect of insulin by removing the interference of free fatty acids (FFAs), which are known to block GH release. Six obese subjects (four men and two women; age, 30.8 +/- 5.2 years; body mass index, 36.8 +/- 2.8 kg/m2 [mean +/- SE]) and six normal subjects (four men and two women; age, 25.8 +/- 1.9 years; body mass index, 22.7 +/- 1.1 kg/m2) received intravenous (i.v.) GH-releasing hormone (GHRH) 0.6 microg/kg under three experimental conditions: (1) i.v. 0.9% NaCl infusion and oral placebo, (2) i.v. 0.9% NaCl infusion and oral acipimox, an antilipolytic agent able to reduce FFA levels (250 mg at 6 and 2 hours before GHRH), and (3) euglycemic-hyperinsulinemic clamp (insulin infusion rate, 0.4 mU x kg(-1) x min(-1)). As expected, after placebo, the GH response to GHRH was lower for obese subjects versus normals (488 +/- 139 v 1,755 +/- 412 microg/L x 120 min, P < .05). Acipimox markedly reduced FFA levels and produced a mild reduction of insulin levels; under these conditions, the GH response to GHRH was increased in both groups, remaining lower in obese versus normal subjects (1,842 +/- 360 v 4,871 +/- 1,286 microg/L x 120 min, P < .05). In both groups, insulin infusion yielded insulin levels usually observed under postprandial conditions and reduced circulating FFA to the levels observed after acipimox administration. Again, the GH response to GHRH was lower for obese subjects versus normals (380 +/- 40 v 1,075 +/- 206 microg/L x 120 min, P < .05), and in both groups, it was significantly lower than the corresponding response after acipimox. In obese subjects, as previously reported in normals, the GH response to GHRH was inversely correlated with the mean serum insulin (r = -.70, P < .01). In conclusion, our data indicate that in the obese, as in normal subjects, the GH response to GHRH is a function of insulin levels. The finding that after both the acipimox treatment and the insulin clamp the obese still show higher insulin levels and a lower GH response to GHRH than normal subjects suggests that hyperinsulinemia is a major determinant of the reduced GH release associated with obesity.


Asunto(s)
Hormona Liberadora de Hormona del Crecimiento/farmacología , Hormona de Crecimiento Humana/sangre , Insulina/sangre , Obesidad/fisiopatología , Adulto , Índice de Masa Corporal , Ácidos Grasos no Esterificados/sangre , Femenino , Técnica de Clampeo de la Glucosa , Humanos , Hiperinsulinismo/fisiopatología , Hipolipemiantes/farmacología , Insulina/farmacología , Masculino , Obesidad/sangre , Pirazinas/farmacología
18.
Photochem Photobiol ; 77(1): 5-9, 2003 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-12856875

RESUMEN

Nuclear magnetic resonance measurements indicate that hypericin exists in the same "normal" tautomeric form irrespective of whether the solvent is dimethyl sulfoxide or tetrahydrofuran. This result is discussed in the context of previous experimental and theoretical work. It is concluded that solvent perturbations cannot induce tautomerization in hypericin.


Asunto(s)
Perileno/análogos & derivados , Perileno/química , Solventes/química , Antracenos , Polarización de Fluorescencia , Espectroscopía de Resonancia Magnética , Estructura Molecular , Espectrofotometría Atómica , Estereoisomerismo
19.
Ann Ist Super Sanita ; 31(1): 197-209, 1995.
Artículo en Inglés | MEDLINE | ID: mdl-8546369

RESUMEN

For correct enforcement of an external quality assessment (EQA) scheme, suitable parameters are required for the assessment of analytical performance. Traditional EQA schemes have always been chiefly concerned with the agreement of analytical results between laboratories. Although we consider this concept to be important, we also believe that particular attention must be paid to the quality of the clinical information, in relation to correct use of the results. On the basis of this principle, we have developed an EQA model which, besides considering the absolute value, also take the reference limits (RLs) into consideration by means of the normalization procedure. The evaluation of clinical information is of vital importance, especially in relation to immunoassays, since the low degree of standardization between methods, and the ensuing phenomenon of relative inaccuracy, make the use of suitable RLs essential. Actually, analysis of the results reveals a high degree of heterogeneity in the RLs used by the laboratories, even within the same method-groups.


Asunto(s)
Sistemas de Información en Laboratorio Clínico/normas , Sistemas de Información en Laboratorio Clínico/organización & administración , Sistemas de Información en Laboratorio Clínico/estadística & datos numéricos , Procesamiento Automatizado de Datos/normas , Humanos , Italia , Proyectos Piloto , Garantía de la Calidad de Atención de Salud/organización & administración , Garantía de la Calidad de Atención de Salud/estadística & datos numéricos , Control de Calidad
20.
Minerva Chir ; 54(7-8): 491-4, 1999.
Artículo en Italiano | MEDLINE | ID: mdl-10528481

RESUMEN

BACKGROUND AND AIM: Carcinoma of the gallbladder is a rare pathology which is extremely malignant with a fatal prognosis owing to its difficult and late diagnosis. It represents 3% of all digestive tumours and is predominant in females. The major risk factor is gallbladder stones. METHODS: A total of 14 gallbladder neoplasms were diagnosed in 798 cholecystectomies performed from October 1990 to October 1995, with a male/female ratio of 6: 1 and a mean age of 68 years and 11 months. Biliary colic and jaundice represented approximately 93% of symptoms present in this series. Fourteen cholecystectomies were performed in association with other forms of surgery (1 GEA, 2 drainage acc. Kehr, 1 hemicolectomy, 1 resection of the hepatic bed, 1 hepaticojejunostomy). RESULTS: The operative mortality was nil. Mean survival was 1 year, 4 months and 15 days, and was obviously higher in the early stages. Four patients (all female) are still alive (mean survival 2 years 10 months 9 days). The five-year survival rate reported in the literature does not exceed 5-10%. Surgery does not currently give satisfactory results. In the light of present knowledge it is important to intervene on the risk factors in the form of laparoscopic cholecystectomies for patients with lithiasis or gallbladder polyps. CONCLUSIONS: Diagnosis must be as early as possible during the "early cancer" phase in order to ensure that surgery is oncologically radical and therefore also remedial.


Asunto(s)
Carcinoma/cirugía , Neoplasias de la Vesícula Biliar/cirugía , Anciano , Carcinoma/mortalidad , Carcinoma/patología , Colecistectomía , Drenaje , Femenino , Neoplasias de la Vesícula Biliar/mortalidad , Neoplasias de la Vesícula Biliar/patología , Humanos , Masculino , Persona de Mediana Edad , Estadificación de Neoplasias
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