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Biomedical subjects

F Greco

Publications and source records attributed to F Greco.

At least 19 recordsLinked to original sources
PubMed2006

Laparoscopic resection with intraoperative radiotherapy: a new step in the multimodal treatment of advanced colorectal cancer.

BACKGROUND: Local recurrence is one of the most important problems related to resection of rectal cancer in locally advanced cases (T3-T4). Total mesorectal excision (TME) is the mainstay of surgical therapy, although many articles have been published about the availability of intraoperative radiotherapy (IORT) for the control of locally advanced rectal cancers. METHODS: The authors describe six patients affected by advanced rectal cancer (T3N1) whom they treated with neoadjuvant radiochemotherapy and laparoscopic rectal resection combined with TME and IORT. RESULTS: The operative time did not exceed 6 h in any case with IORT treatment. The procedure itself and the transfer of patients to the radiotherapy room accounted for about 2 h. The postoperative course was uneventful in every case, and all the patients were discharged within the first 8 postoperative days. CONCLUSIONS: This report describes the technical aspect and the feasibility of IORT associated with laparoscopic surgical resection for rectal cancer.

Adult↗
PubMed2006

Synthesis and biological in vitro evaluation of novel PEG-psoralen conjugates.

Psoralens are well-known photosensitizers, and 8-methoxypsoralen and 4,5',8-trimethylpsoralen are widely used in photomedicine as "psoralens plus UVA therapy" (PUVA), in photopheresis, and in sterilization of blood preparations. In an attempt to improve the therapeutic efficiency of PUVA therapy and photopheresis, four poly(ethylene glycol) (PEG)-psoralen conjugates were synthesized to promote tumor targeting by the enhanced permeability and retention (EPR) effect. Peptide linkers were used to exploit specific enzymatic cleavage by lysosomal proteases. A new psoralen, 4-hydroxymethyl-4',8-dimethylpsoralen (6), suitable for polymer conjugation was synthesized. The hydroxy group allowed exploring different strategies for PEG conjugation, and linkages with different stability such ester or urethanes were obtained. PEG (5 kDa) was covalently conjugated to the new psoralen derivative using four different linkages, namely, (i) direct ester bond (7), (ii) ester linkage with a peptide spacer (8), (iii) a carbamic linker (9), and (iv) a carbamic linker with a peptide spacer (12). The stability of these new conjugates was assessed at different pHs, in plasma and following incubation with cathepsin B. Conjugates 7 and 8 were rapidly hydrolyzed in plasma, while 9 was stable in buffer and in the presence of cathepsin B. As expected, only the conjugates containing the peptide linker released the drug in presence of cathepsin B. In vitro evaluation of the cytotoxic activity in the presence and absence of light was carried out in two cell lines (MCF-7 and A375 cells). Conjugates 7 and 8 displayed a similar activity to the free drug (probably due to the low stability of the ester linkage). Interestingly, the conjugates containing the carbamate linkage (9 and 12) were completely inactive in the dark (IC50 > 100 microM in both cell lines). However, antiproliferative activity become apparent after UV irradiation. Conjugate 12 appears to be the most promising for future in vivo evaluation, since it was relatively stable in plasma, which should allow tumor targeting and drug release to occur by cathepsin B-mediated hydrolysis.

Cell Line↗
PubMed2006

[Multiple arterial ischemic strokes in a child with moyamoya disease and Mycoplasma pneumoniae infection].

Moyamoya disease is a rare disorder characterised by a progressive occlusion or stenosis of the distal portions of bilateral internal carotid arteries with the development of a network of collateral vessels. Pediatric patients show transient ischemic attacks or strokes; diagnosis is made on the basis of clinical and radiographic findings. The case of a 2-year-old female, which after a Mycoplasma pneumoniae infection presented multiple cerebral strokes is reported. A diagnosis of moyamoya disease was made on the basis of neuroradiological findings; neurological complications due to Mycoplasma infection are reported and the relationship between disease and infection are discussed.

Carotid Artery, Internal↗
PubMed2005

Stress tensor of a dilute suspension of spheres in a viscoelastic liquid.

The stress tensor for a dilute suspension of buoyancy-free, inertialess, non-Brownian, rigid spheres immersed in a viscoelastic liquid is determined via a perturbative expansion. The perturbation parameter is the Deborah number De, giving the ratio between the characteristic time of the liquid and the characteristic time of the imposed flow. The stress is also calculated from numerical simulations of continuity and momentum equations for the single sphere problem. Excellent agreement is found between the two predictions. Good agreement is found also with respect to experimental data found in the literature.

Journal Article↗
PubMed2005

Nasal surgery and eustachian tube function: effects on middle ear ventilation.

OBJECTIVES: To investigate the effect of nasal obstruction surgery on eustachian tube function and middle ear ventilation. DESIGN: Prospective study. SETTING: University Campus Bio-Medico of Rome. PARTICIPANTS: Forty consecutive patients who underwent nasal surgery were evaluated for middle ear ventilation and tubal function. MAIN OUTCOME MEASURES: Pre- and postoperative Valsalva and Toynbee tubal function tests, tympanometry and ear fullness sensation were evaluated for both ears of each patient. RESULTS: Results of postoperative tubal function tests were significantly better than preoperative ones (90% versus 46%; P<0.001). No significant difference in tympanometric values was found. The majority (95%) of the patients reported a postoperative improvement of ear fullness sensation compared with preoperative (25%; P<0.001). CONCLUSIONS: Surgery for chronic nasal obstruction significantly improves clinical tubal function but 1-month postoperative tympanometric findings remain almost the same.

Acoustic Impedance Tests↗
PubMed2005

Polymer-drug conjugates: towards a novel approach for the treatment of endrocine-related cancer.

The last decade has seen successful clinical application of polymer-protein conjugates (e.g. Oncaspar, Neulasta) and promising results in clinical trials with polymer-anticancer drug conjugates. This, together with the realisation that nanomedicines may play an important future role in cancer diagnosis and treatment, has increased interest in this emerging field. More than 10 anticancer conjugates have now entered clinical development. Phase I/II clinical trials involving N-(2-hydroxypropyl)methacrylamide (HPMA) copolymer-doxorubicin (PK1; FCE28068) showed a four- to fivefold reduction in anthracycline-related toxicity, and, despite cumulative doses up to 1680 mg/m2 (doxorubicin equivalent), no cardiotoxicity was observed. Antitumour activity in chemotherapy-resistant/refractory patients (including breast cancer) was also seen at doxorubicin doses of 80-320 mg/m2, consistent with tumour targeting by the enhanced permeability (EPR) effect. Hints, preclinical and clinical, that polymer anthracycline conjugation can bypass multidrug resistance (MDR) reinforce our hope that polymer drugs will prove useful in improving treatment of endocrine-related cancers. These promising early clinical results open the possibility of using the water-soluble polymers as platforms for delivery of a cocktail of pendant drugs. In particular, we have recently described the first conjugates to combine endocrine therapy and chemotherapy. Their markedly enhanced in vitro activity encourages further development of such novel, polymer-based combination therapies. This review briefly describes the current status of polymer therapeutics as anticancer agents, and discusses the opportunities for design of second-generation, polymer-based combination therapy, including the cocktail of agents that will be needed to treat resistant metastatic cancer.

Antineoplastic Agents↗
PubMed2005

Comparison of sequential combined spinal-epidural anesthesia and spinal anesthesia for cesarean section.

AIM: The aim of our study was to prove that by using sequential combined spinal-epidural (CSE) anesthesia it is possible to overcome the limits connected to the use of spinal anesthesia (SA) alone for elective cesarean section. METHODS: We examined 100 women submitted to cesarean section; SA was administered to 50 patients and sequential CSE technique to the other 50. In every woman before execution of the anesthesia we infused 500 mL of a plasma expander and a previous administration of 5 mg of ephedrine. The CSE was executed at the L1-L2 intervertebral space, administering in spinal anesthesia 5 mg of levobupivacaine with 5 _g of sufentanil, and in peridural anesthesia 10-12 mL of levobupivacaine 0.25% according to the patient's height. The peridural catheter for postoperative analgesia was then positioned. In the group of women submitted only to SA, 7.5-8 mg of levobupivacaine was injected, according to the patient's height, in the L1-L2 intervertebral space, with 5 _g of sufentanil. We considered the following adverse effects: hypotension; bradycardia; vomiting; intraoperative discomfort and motor block. RESULTS: The results obtained showed that, with a P < or = 0.05, the incidence of motor block (P < 0.001), discomfort (P < 0.001) and hypotension (P = 0.021) in the SA group is greater than in the CSE group. The difference in the incidence of vomiting (P = 0.147) and bradycardia (P = 0.067) between the 2 groups is not statistically significant. CONCLUSIONS: In our opinion sequential CSE can be considered an important step forward in the regional anesthesia used for elective cesarean section.

Anesthesia, Epidural↗
PubMed2004

Is the chronologic age a contra-indication for surgical palliation of unresectable periampullary neoplasms?

METHODS: Early and late results of surgical palliation for unresectable periampullary neoplasms were evaluated in 24 patients older than 70 years and compared with the same results obtained from 33 younger patients. The two groups of patients were comparable, except for age. Biliary bypass associated to gastric bypass was the most common performed procedure. RESULTS: No significant differences in the results (morbidity, mortality, and outcome) were found in the two groups of patients. In addition, the results of palliative surgery in the elderly were compared with those obtained from a comparable group of 35 patients palliated with endoscopic stent insertion: surgical palliation resulted in better long-term results. CONCLUSIONS: This study provides evidence that the chronologic age is not a contra-indication for surgical palliation of periampullary neoplasms and that surgery provides a better quality of residual life.

Adult↗
PubMed2004

1H NMR spin-spin relaxation and imaging in porous systems: an application to the morphological study of white portland cement during hydration in the presence of organics.

Proton nuclear magnetic resonance (NMR) spin-spin relaxation and imaging have been applied to investigate white Portland cement pastes during hydration in the absence and in the presence of organic solvents. The main organic solvent investigated was methanol, alone or together with the organic waste 2-chloroaniline (2-CA), an aromatic amine representative of an important class of highly toxic compounds. For all the analysed samples, prepared with a solvent-to-cement ratio of 0.4, the decay of the echo magnetization has been fitted by adopting a model that combines an exponential component with a gaussian one. The calculated independent relaxation parameters have been discussed in terms of morphological and dynamical changes that occur during the cement hardening process and pore formation. Three kinds of water molecules: "solid-like" (chemically and physically bound), "liquid-like" (porous trapped) and "free" water, endowed with anisotropic, near isotropic and isotropic motion, respectively, were identified. Spin-echo images collected on the same samples during the hydration kinetics, allowed the changes of water and solvents spatial distribution in the porous network to be monitored, showing percolation phenomena and confirming the multimodal open channels structure of the hardened cement system. Both T(2) relaxation and imaging data indicated that a pronounced delay occurs in the cement hardening when organics are present.

Construction Materials↗
PubMed2004

Activation of the small GTPase Rap2B in agonist-stimulated human platelets.

The activation of the small GTPase Rap2B in resting and agonist-stimulated human platelets was investigated. Both thrombin, that stimulates heterotrimeric G-protein-coupled receptors, and the GPVI ligand convulxin, that activates a tyrosine-kinase based signaling pathway, were able to induced the rapid and sustained binding of GTP to Rap2B. Similarly, a number of other agonists tested, previously known to activate the highly related protein Rap1B, were also able to stimulate Rap2B. In contrast, platelet antagonists that increase the intracellular concentration of cAMP did not signal to Rap2B. Thrombin- and convulxin-induced activation of Rap2B was not dependent on thromboxane A2, did not require the interaction of the protein with the cytoskeleton, and was not regulated by integrin alphaIIbbeta3-dependent outside-in signaling. When secreted ADP was neutralized, activation of Rap2B induced by thrombin, but not by convulxin, was significantly reduced. ADP itself was found to induce the rapid and sustained binding of GTP to Rap2B, and this effect was predominantly mediated by stimulation of the Gi-coupled P2Y12 receptor. Activation of Rap2B promoted by both thrombin and convulxin was regulated by intracellular Ca2+, while protein kinase C was found to be involved in convulxin- but not in thrombin-induced activation of Rap2B. Moreover, Rap2B activation induced by thrombin, but not by convulxin, was totally dependent on phosphatidylinositol 3-kinase activity. These results demonstrate that the small GTPase Rap2B is involved in platelet activation, and outline some important differences between the regulation of highly related GTPases Rap2B and Rap1B in human platelets.

Adenosine Diphosphate↗
PubMed2004

[Oral-facial-digital syndrome type I. A case report].

Oral-facial-digital syndrome type I (OFDI) is a congenital X-linked dominant disorder characterized by anomalies of the oral cavity, face and digits sometimes associated to cerebral malformations and polycystic kidney disease. The gene, responsible for this syndrome, is ofd1. Clinically it is seen only in females. Lesions of the mouth include median pseudoclefting of the upper lip, clefts of the palate and tongue, and dental anomalies (missing or supernumerary teeth, enamel hypoplasia, and teeth malpositions). Dysmorphic features affecting the head include hypertelorism, frontal bossing, micrognathia, facial asymmetry and broadened nasal ridge. The digital abnormalities are syndactyly, clinodactyly, brachydactyly and, rarely, pre or post-axial polydactyly. Less frequently ex-pressed phenotypic anomalies include skin milia, alopecia, deafness and trembling. Sometimes the diagnosis of OFDI can be difficult because there is an overlap with other types of oral-facial-digital syndromes. A sporadic case of OFDI, with 7 lower incisors, both in the primary and permanent dentition, is reported. This dental anomaly is very unusual because in literature only supernumerary cuspids are reported. In the light of this case, the authors discuss the oral phenotypic expression of ofd1 gene and its role in human odontogenesis.

Child↗
PubMed2004

Benign paroxysmal positional vertigo: diagnosis and treatment.

Benign paroxysmal positional vertigo (BPPV) has been recognized as the most common vestibular disorder; it is a term coined in 1952 by Dix and Hallpike, and it is most commonly used to describe a disease with a characteristic clinical presentation believed to be caused by free-floating particles leaving the macula and entering one of the semicircular canals, usually the posterior one, more rarely the horizontal or superior ones. A lot of studies showed as the prevalence is higher in females than in males with a ratio of 2:1; furthermore, prevalence increases with the age: the mean age at onset is 54 years, with a range of 11 to 84 years. The most important clinical manifestations of BPPV are: vertigo, lightheadedness, dysequilibrium and sometimes nausea, vomiting, pallor and sweating. The diagnosis of BPPV is very simple through the Dix-Hallpike test or the diagnostic Semont's maneuver; the increasing information about the BPPV's pathogenesis has led most authors to consider the rehabilitative therapy, and in particular the so-called Semont's "liberatory" maneuver, as the first choice treatment of BPPV, in relation to its quickness and efficacy. In this treatment the debris are moved from the posterior semicircular canal to another location within the vestibular labyrinth. In our review we consider the possible pathogenesis of this disease and the best therapies, like repositioning maneuvers, in a patient affected by BPPV.

Adolescent↗
PubMed2003

Investigation of work-related disorders in truck drivers using RULA method.

A high incidence of spinal disorders is observed in professional drivers; in particular, back and neck pain result in high rates of morbidity and low retirement age. A sample of 77 drivers, of rubbish-collection vehicles who sit in a standard posture and of road-washing vehicles, who drive with the neck and trunk flexed, bent and twisted, was studied using RULA, a method for the evaluation of the exposure to risk factors associated with work-related upper-limb disorders. Results showed a significant association between trunk and neck scores and all self-reported pains, aches or discomforts in the trunk or neck regions in all subjects. In particular, the neck score was significant in both postures, reflecting high loading of the neck. Significantly different posture scores were also recorded for drivers using an adjustable vs. a non-adjustable seat. In this first RULA study of the working posture of professional truck drivers, the method proved to be a suitable tool for the rapid evaluation of the loading of neck and trunk.

Adult↗
PubMed2003

Stapes surgery in relation to age.

This prospective study aims to evaluate the efficacy of stapedotomy in relation to age. Eighty-four ears of 82 consecutive patients who underwent stapedotomy were studied. Patients were divided into five groups according to their age. In each patient, we evaluated the pre- and postoperative auditory thresholds, according to the Committee on Hearing and Equilibrium of the American Academy of Otolaryngology - Head and Neck Surgery guidelines. Statistically significant (P < 0.05) differences between the pre- and postoperative air conduction thresholds were observed in all groups. Statistically significant reductions of air-bone gap were observed at lower-medium frequencies (250, 500 and 1000 Hz) in the elderly as well as in the younger patients. We did not find a higher susceptibility of the inner ear to surgical trauma in the elderly in comparison to the younger patients. Our data show that stapedotomy results in older adults are comparable to those obtained in the younger, without an increased incidence of complications.

Adult↗
PubMed2003

Bilateral irreversible hearing loss associated with the combination of carboplatin and paclitaxel chemotherapy: a unusual side effect.

The regimen with paclitaxel and platinum compound (carboplatin or cisplatin) is the standard chemotherapy for patients with advanced ovarian cancer. Ototoxity for carboplatin and paclitaxel alone or combined is rarely observed. We report the case of a 35-year old female with advanced ovarian cancer who developed sudden bilateral sensorineural hearing loss related to paclitaxel and carboplatin based chemotherapy. This uncommon adverse effect of carboplatin and paclitaxel alone or combined is discussed and the literature reviewed. Hearing monitoring should be mandatory to evaluate the real incidence of clinical and sub-clinical hearing modification induced by carboplatin and paclitaxel based chemotherapy.

Adult↗