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Biomedical subjects

A Cavallo

Publications and source records attributed to A Cavallo.

At least 19 recordsLinked to original sources
PubMed2006

Dynamic sonography of the forefoot in Morton's syndrome: correlation with magnetic resonance and surgery.

PURPOSE: The aim of this paper is to demonstrate the efficacy of the dynamic study of the forefoot during lateral compression of the metatarsal heads (Mulder's manoeuvre) in the visualisation of Morton's neuroma. The data were compared with clinical signs, conventional ultrasound (US), magnetic resonance (MR) and surgical findings. MATERIALS AND METHODS: Forty forefeet in 38 patients were investigated with conventional and dynamic US using a 10-MHz linear probe (Esaote Technos). MR was performed in 26 forefeet with a 0.2-T scanner (Esaote Artoscan). Twenty intermetatarsal spaces in 18 forefeet were explored surgically. RESULTS: Thirty-seven intermetatarsal masses were identified through dynamic US in the 40 forefeet investigated (two double localisations). This method was clearly more effective than conventional US, which could only locate 25. In those forefeet investigated with MR, it was possible to confirm dynamic US findings in 16 out of 22. In one of the six cases unconfirmed by MR, a neuroma was removed following surgery. Twenty masses (19 neuromas and one synovial ganglion) were found in the 18 forefeet treated by surgery. CONCLUSIONS: Clinical evaluation, which is fundamental for accurate diagnosis, can make use of dynamic US in the first instance in order to confirm clinical signs and identify the correct site and number of masses. In our opinion, MR maintains a primary role in differential diagnosis with other diseases (mainly stress fractures, bursitis, ganglion cysts or tendon tumour sheaths).

Adult↗
PubMed2006

Lung donors selection criteria: a review.

Lung transplantation has had increasing success worldwide and it became an acceptable treatment modality in end-stage pulmonary diseases. The insufficient supply of donor lungs, resulting in prolonged waiting time, and the significant rise of patients on the waiting list, have forced the most experienced transplantation centers to redefine the acceptable lung donor criteria including marginal allografts. Existing standard lung donor criteria have been established in the first period of lung transplantation activity, based mainly on opinions and individual experiences rather than on existing evidences: the paucity of donors may be also explained by the rigid application of these criteria. The quality of donor organs has a significant impact on early and long-term recipient outcome. Recent studies have demonstrated that the use of marginal donors did not affect early and late recipient outcome, and significantly increased the number of transplants performed. The aim of this paper is to review how the main lung donor selection criteria have been changed and how they influence the recipient outcome.

Brain Death↗
PubMed2005

Unmixing of polymer blends confined in ultrathin films: crossover between two-dimensional and three-dimensional behavior.

The interplay between chain conformations and phase separation in binary symmetric polymer mixtures confined into thin films by "neutral" hard walls (i.e., walls that do not preferentially attract or repel one of the two components of the mixture) is studied by Monte Carlo simulations. Using the bond fluctuation model on a simple cubic lattice in the semi grand canonical ensemble, we locate the critical temperature of demixing via finite size scaling methods for a wide range of chain lengths (16 </= N </= 256 effective monomers per chain) and film thicknesses (2 </= D </= 19 lattice spacings). Simultaneously, we investigate the geometrical structure of the chains, showing that despite using melt densities there are pronounced "correlation hole effects", in particular for the smaller values of D. Also the components of the radius of gyration and end-to-end distance parallel and perpendicular to the confining walls are analyzed and their scaling behavior is studied. Evidence is presented that for strictly two-dimensional polymers (as occur for D = 2) the average number of intermolecular contacts scales with chain length N as z(c) proportional, variant N(-3/8) and therefore the critical temperature scales as T(c) proportional, variant N(5/8), whereas for values of D that exceed the excluded volume screening length, z(c) remains nonzero for N --> infinity, and hence T(c) proportional, variant N. However, strong deviations from the Flory-Huggins theory occur as long as the unperturbed chain dimension exceeds D, and the critical behavior falls in the universality class of the two-dimensional Ising model for any finite value of D.

Journal Article↗
PubMed2005

[Methimazole versus methimazole and diphosphonates in hyperthyroid and osteoporotic patients].

AIM: It is well-know that hyperthyroidism is one of the key causes of secondary osteoporosis. High values of thyroid hormones increase the bone mineral turnover speed by promoting osteoclastic and osteoblastic activities. The aim of our study is to evaluate the increase of bone mineral density (BMD) in osteoporotic and hyperthyroid patients treated with only antithyroid drugs versus patients treated with antithyroid drugs and diphosphonates. METHODS: Twenty-six elderly male patients, 65-75 years, were selected. In all these patients, thyroid function (FT3, FT4, TSH, Tg, AbTg, AbTPO) was evaluated at baseline and after 6 and 12 months from the start of medical treatment; the following were evaluated: BMD, calcium serum, phosphorus serum, alkaline phosphatase, PTH and 24 hours urinary calcium, phosphorus and hydroxyprolin. Thirteen patients (group 1) were treated with antithyroid drugs (methimazole 5-20 mg/die/os) and diphosphonates (alendronate 10 mg/die/os). The control group of 13 patients (group 2) was treated with antithyroid drugs only. RESULTS: After 6 months of treatment, the patients of group 1 showed a mean increase of 2.5% in lumbar spine BMD compared with a mean increase of 0.3% in group 2 (p<0.01). After 12 months, group 1 showed a mean increase of 6.2% in lumbar spine BMD, compared with a mean increase of 2% in group (p<0.001). CONCLUSIONS: The combination of antithyroid and diphosphonates drugs appears to be more efficacious than antithyroid therapy alone for the treatment of osteoporosis in male hyperthyroid patients.

Aged↗
PubMed2004

Mapping SNPs to protein sequence and structure data.

MOTIVATION: Data on both single nucleotide polymorphisms and disease-related mutations are being collected at ever-increasing rates. To understand the structural effects of missense mutations, we consider both classes under the term single amino acid polymorphisms (SAAPs) and we wish to map these to protein structure where their effects can be analyzed. Our initial aim therefore is to create a completely automatically maintained database of SAAPs mapped to individual residues in the Protein Data Bank (PDB) updated as new mutations or structures become available. RESULTS: We present an integrated pipeline for the automated mapping of SAAP data from HGVbase to individual PDB residues. Achieving this in a completely automated and reliable manner is a complex task. Data extracted from HGVbase are mapped to EMBL entries to confirm whether the mutation occurs in an exon and, if so, where in the sequence it occurs. From there we map to Swiss-Prot entries and thence to the PDB. AVAILABILITY: The resulting database may be accessed over the web at http://www.bioinf.org.uk/saap/ or http://acrmwww.biochem.ucl.ac.uk/saap/ CONTACT: a.martin@biochem.ucl.ac.uk.

Algorithms↗
PubMed2004

The significance of associated pre-invasive lesions in patients resected for primary lung neoplasms.

OBJECTIVE: To evaluate the prevalence and clinico/prognostic significance of the presence of pre-invasive lesions in patients resected for primary lung neoplasm. METHODS: From 1993 to 2002, 1090 patients received resection for primary lung carcinomas. Of these, 73 presented an associated pre-invasive lesion in the surgical specimen distant from the primary tumour. Classification of pre-invasive lesions included Atypical Adenomatous Hyperplasia (AAH); Carcinoma In Situ (CIS) either diffuse or at the bronchial resection margin; Diffuse Idiopathic Pulmonary Neuroendocrine Cell Hyperplasia (DIPNECH). Correlation between the presence of pre-invasive lesion and the following variables were calculated by logistic regression analysis: sex, age, median tumour size, histology, histologic differentiation, histologic evidence of invasiveness (vascular and perineural invasion), peritumoural lymphocytic infiltrate, pTNM, lobe location, history of previous malignancy. Survival rates were computed using Kaplan-Meier method and survival differences with the total patient population of resected lung carcinomas were tested using the log-rank method. RESULTS: There were 28 AAH, 42 CIS (5 at the bronchial resection margin) and 3 DIPNECH. Histology of the primary tumor included bronchioloalveolar carcinoma (9 patients), adenocarcinoma (19), squamous cell carcinoma (39), typical carcinoid tumour (3) and adenosquamous carcinoma (3). Overall prevalence of pre-invasive lesion was 6.7%. A strong correlation was found between the presence of AAH and the co-existence of either adenocarcinoma, bronchioloalveolar carcinoma or mixed adenocarcinoma-containing tumours (P = 0.00002) between CIS and squamous cell carcinoma (P = 0.009) and between DIPNECH and carcinoid tumours (P = 0.001). No significant correlation was found between the presence of any type of pre-invasive lesion and sex, age, median tumour size, histologic differentiation, histologic evidence of invasiveness, pTNM, lobe location and history of previous malignancy or the probability to develop a second primary lung carcinoma in the remaining lobe(s) after resection. Survival rates in the patients with AAH and CIS were not significantly different from those of patients without pre-invasive lesion (P = 0.3 and P = 0.1). CONCLUSIONS: Associated pre-invasive lesions in patients resected for primary lung neoplasms are not infrequent. AAH is associated with adenocarcinoma, CIS with squamous cell carcinoma, DIPNECH with typical carcinoid tumours. Our experience indicates that in these patients histology, stage distribution and survival do not differ from the total population of resected patients with lung tumors.

Adenocarcinoma↗
PubMed2001

Two-time Green's functions and the spectral density method in nonextensive classical statistical mechanics.

The two-time retarded and advanced Green's function technique is formulated in nonextensive classical statistical mechanics within the optimal Lagrange multiplier framework. The main spectral properties are presented and a spectral decomposition for the spectral density is obtained. Finally, the nonextensive version of the spectral density method is given and its effectiveness is tested by exploring the equilibrium properties of a classical ferromagnetic spin chain.

Journal Article↗
PubMed2001

Descending necrotizing mediastinitis: surgical management.

OBJECTIVE: Descending necrotizing mediastinitis (DNM) is a primary complication of cervical or odontogenical infections that can spread to the mediastinum through the anatomic cervical spaces. METHODS: Between April 1994 and April 2000, 13 patients, mean age 39.23+/-18.47 (median 38, range 16-67) years, with DNM were submitted to surgical treatment. Primary odontogenic abscess occurred in six, peritonsillar abscess in five and post-traumatic cervical abscess in two patients. Diagnosis was confirmed by computed tomography (CT) of the neck and chest. All patients underwent surgical drainage of the cervico-mediastinal regions by a bilateral collar incision associated with right thoracotomy in ten cases. RESULTS: Six patients out of 13 required reoperation. Two patients previously submitted only to cervical drainage required thoracotomy; four patients, which have been submitted to cervico-thoracic drainage, underwent contralateral thoracotomy in two cases and ipsilateral reoperation in two cases. Ten patients evolved well and were discharged without major sequelae; three patients died of multiorgan failure related to septic shock. Mortality rate was 23%. CONCLUSION: Early diagnosis by CT of the neck and chest suggest a rapid indication of surgical approach to DNM. Ample cervicotomy associated with mediastinal drainage via large thoracotomic incision is essential in managing these critically ill patients and can significantly reduce the mortality rate for this condition, often affecting young people, to acceptable values.

Abscess↗
PubMed2001

Personal radon dosimetry from eyeglass lenses.

Eyeglass lenses are commonly composed of allyl-diglycol carbonate (CR-39), an alpha-particle detecting plastic, thus making such lenses personal radon dosemeters. Samples of such lenses have been obtained, etched to reveal that radon and radon progeny alpha tracks can be seen in abundance, and sensitivities have been calibrated in radon chambers as a primary calibration, and with a uranium-based source of alpha particles as a convenient secondary standard. With one exception natural, environmental (fossil) track densities ranged from less than 3,000 to nearly 70,000 per cm2 for eyeglasses that had been worn for various times from one to nearly five years. Average radon concentrations to which those wearers were exposed are inferred to be in the range 14 to 130 Bq x m(-3) (0.4 to 3.5 pCi x l(-1)). A protocol for consistent, meaningful readout is derived and used. In the exceptional case the fossil track density was 1,780,000 cm(-2) and the inferred (24 h) average radon concentration was 6500 Bq x m(-3) (175 pCi x l(-1)) for a worker at an inactive uranium mine that is used for therapy.

Eyeglasses↗
PubMed2001

Surgical management of acquired non-malignant tracheo-esophageal fistulas.

BACKGROUND: The aim of this study was to evaluate the results of one-stage surgical management of acquired non-malignant tracheo-esophageal fistulas (TEF). METHODS: Six consecutive patients, 2 men and 4 women with median age of 65 (range 34-71) years had tracheo-esophageal fistulas resulting from a median of 33 (range 20-86) days of intubation via oro-tracheal or tracheostomy tubes. Median TEF length was 2.6 (range 1.8-3.5) cm and the defect was associated with a tracheal stenosis near or immediately below the stoma in 4 cases (66%). Tracheal resection and anastomosis with primary esophageal closure was carried out in 4 patients; direct closure of the tracheal and esophageal defects with muscle flap interposition was performed in 2 patients: tracheal stoma was left in site because of the high risk of postoperative respiratory insufficiency related to chronic obstructive pulmonary disease. RESULTS: All six patients had complete control of the TEF. One perioperative death occurred on day 27 (16%) related to the recurrence of endocranial bleeding. The 5 long-term survivors were routinely submitted to tracheo-bronchoscopic control and only one (20%) revealed granulation tissue at the suture line requiring two consecutive bronchoscopic removals. CONCLUSIONS: Postintubation tracheoesophageal fistula is usually best treated with one-stage surgical procedure: which preferably consists of tracheal resection and anastomosis and primary esophageal closure.

Aged↗
PubMed2001

Fungal infections in lung transplantation. Incidence, risk factors and prognostic significance.

BACKGROUND AND AIM OF THE WORK: Fungal infections are frequent following lung transplantation and are associated with high mortality and morbidity. The study aims at 1) reporting our experience with fungal infections after lung transplantation; 2) identifying statistically significant correlations between the occurrence of fungal infections and bacterial infections, cytomegalovirus disease, rejection and steroid therapy; 3) assessing whether the presence of fungal infection has an impact on long-term survival. METHODS: 60 lung transplant recipients were studied with respect to incidence, pattern of presentation and median time to presentation of fungal infection after the transplant. Correlation analysis of the variables of interest was undertaken in 30 patients who had a minimum follow-up of 1 year following transplant. RESULTS: The prevalence of fungal infection was 44%; severe infections occurred in 5 patients (11%). The presence of Candida preoperatively was not associated with an increased risk of fungal infection. In a logistic regression analysis, a significant correlation was found between the occurrence of fungal infection and the following variables: respiratory bacterial infections (p = 0.0003), cytomegalovirus disease (p = 0.00001) and steroid therapy (p = 0.04). No statistically significant difference was found between patients who experienced a fungal infection and those who did not, either in univariate or multivariate survival analysis (p = 0.08). CONCLUSIONS: 1) fungal infections are frequent in lung transplant recipients and may be severe in more than 10% of the cases; 2) the presence of fungi preoperatively is not a contraindication to transplantation: an antifungal prophylaxis is probably indicated in such cases postoperatively; we recommend the use of the less nephrotoxic liposomal Amphotericin B by aerosol route; 3) a statistically significant association exists between fungal infections and both steroid therapy and CMV disease; this suggests that a similar antifungal prophylaxis is indicated in these clinical circumstances; 4) the presence of fungal infection is not an independent prognostic factor of long-term survival.

Adolescent↗
PubMed2000

Eyeglass lenses for personal radon dosimetry.

Eyeglass lenses are commonly composed of allyl-diglycol carbonate (CR-39), an alpha-particle detecting plastic, thus making such lenses personal radon dosimeters. Samples of such lenses have been etched to reveal that radon and radon progeny alpha tracks can be seen in abundance, and sensitivities have been calibrated in radon chambers as a primary calibration and with a uranium-based source of alpha particles as a convenient secondary standard. Natural, environmental (fossil) track densities ranged from 3,000 to 25,000 cm(-2) for eyeglasses that had been worn for various times from 1 to nearly 5 y. Average radon concentrations to which the wearers were exposed are inferred to be in the range 20 to 130 Bq m(-3) (0.5 to 3.5 pCi L(-1)). Procedures for consistent, meaningful readout are described.

Air Pollutants, Radioactive↗
PubMed1999

Radon progeny unattached fraction in an atmosphere far from radioactive equilibrium.

It is often assumed that the unattached fraction of the exposure to suspended radon progeny activity can be predicted from particle concentration measurements. While this may be true in many circumstances, there are important exceptions to this rule. In particular, in an atmosphere far from radioactive equilibrium, such as a working area in a mine close to a source of radon and supplied with fresh air, the unattached fraction can be a factor of ten or more greater than indicated by a simple particle concentration measurement. Recent measurements made in a diesel powered uranium mine are presented to illustrate this effect.

Air Pollutants↗
PubMed1999

[Endotracheal tube cuff pressure. Monitoring during general anesthesia].

BACKGROUND: To value changes of endotracheal tube cuff pressure during anaesthesia with N2O, using standard tubes or Brandt-system tubes. METHODS: Endotracheal cuff pressure during anaesthesia in three groups of patients has been monitored: Group 1 (n. 41): endotracheal tube with low-pressure cuff using N2O/O2 (2:1 or 1:1); Group 2 (n. 55): Brandt's double cuff-tubes using N2O/O2 (2:1 or 1:1); Group 3 (n. 20-control group): tubes with low-pressure cuff using O2/air. Values of pressure (M +/- DS: p < 0.05) have been compared with ANOVA, Bonferroni's method (p < 0.017). RESULTS AND CONCLUSIONS: Brandt's double cuff-tubes (G2) succeed in avoiding uncontrolled increase of cuff-pressure during anaesthesia with N2O. Standard low-pressure tubes (G1) shown increase of cuff pressure during anaesthesia with N2O which is absent using no N2O (G3).

Anesthesia, General↗
PubMed1998

The specific effects of prior opioid exposure on placebo analgesia and placebo respiratory depression.

Although in most of the cases the placebo response appears to be unpredictable, several factors have been considered in order to explain the placebo analgesic effect. For example, it is widely recognized, albeit with little empirical evidence, that placebo analgesia is more likely to occur after a successful analgesic therapy. On the basis of this assumption, we tested the placebo response in a population of patients who were treated with buprenorphine the day before for relieving postoperative pain. However, due to the high variability of opioid responsiveness, buprenorphine was effective in some patients and poorly effective in some others. Similarly, buprenorphine produced respiratory depression with a large variability, ranging from mild depression to no effect. We found that the placebo analgesic response depended on the buprenorphine analgesic effectiveness of the previous day. Analogously, we found that a placebo respiratory depressant response was more pronounced in those patients with a respiratory depressant response to buprenorphine on the day before, irrespective of the analgesic effectiveness. These specific effects suggest that (1) the placebo effect is experience-dependent; (2) the mechanisms underlying placebo analgesia and placebo respiratory depression are independent from each other and, by considering the role of endogenous opioids in placebo analgesia, might involve different subpopulations of opioid receptors.

Analgesia↗
PubMed1997

Control of postoperative pain by transcutaneous electrical nerve stimulation after thoracic operations.

BACKGROUND: Transcutaneous electrical nerve stimulation (TENS) has been used extensively to control postoperative pain, but its effects are controversial. This is probably due to the different types of operations performed and, therefore, to the varying intensity of postoperative pain. Here we present an extensive study with TENS in 324 patients who underwent different types of thoracic surgical procedures: posterolateral thoracotomy, muscle-sparing thoracotomy, costotomy, sternotomy, and video-assisted thoracoscopy. METHODS: Each patient cohort was randomly subdivided into three treatment groups: TENS, placebo TENS and control. The effectiveness of TENS was assessed by two factors: the time from the beginning of treatment to the request for further analgesia and the total medication intake during the first 12 hours after operation. RESULTS: Whereas posterolateral thoracotomy produced severe pain, muscle-sparing thoracotomy, costotomy, and sternotomy caused moderate pain, and video-assisted thoracoscopy caused only mild pain. The TENS treatment was not effective in the posterolateral thoracotomy group, but it was useful as an adjunct to other medications in the muscle-sparing thoracotomy, costotomy, and sternotomy groups. In contrast, representing the only pain control treatment with no adjunct drugs, it was very effective in patients having video-assisted thoracoscopy. CONCLUSIONS: These findings show that TENS is useful after thoracic surgical procedures only when postoperative pain is mild to moderate; it is uneffective for severe pain.

Endoscopy↗