Biomedical subjects

Marco Moretti

Publications and source records attributed to Marco Moretti.

9 recordsLinked to original sources

PubMed2006

Biodiversity and resilience of arthropod communities after fire disturbance in temperate forests.

Changes in ecosystem functions following disturbances are of central concern in ecology and a challenge for ecologists is to understand the factors that affect the resilience of community structures and ecosystem functions. In many forest ecosystems, one such important natural disturbance is fire. The aim of this study was to understand the variation of resilience in six functional groups of invertebrates in response to different fire frequencies in southern Switzerland. We measured resilience by analysing arthropod species composition, abundance and diversity in plots where the elapsed time after single or repeated fires, as determined by dendrochronology, varied. We compared data from these plots with data from plots that had not burned recently and defined high resilience as the rapid recovery of the species composition to that prior to fire. Pooling all functional groups showed that they were more resilient to single fires than to repeated events, recovering 6-14 years after a single fire, but only 17-24 years after the last of several fires. Flying zoophagous and phytophagous arthropods were the most resilient groups. Pollinophagous and epigaeic zoophagous species showed intermediate resilience, while ground-litter saprophagous and saproxylophagous arthropods clearly displayed the lowest resilience to fire. Their species composition 17-24 years post-burn still differed markedly from that of the unburned control plots. Depending on the fire history of a forest plot, we found significant differences in the dominance hierarchy among invertebrate species. Any attempt to imitate natural disturbances, such as fire, through forest management must take into account the recovery times of biodiversity, including functional group composition, to ensure the conservation of multiple taxa and ecosystem functions in a sustainable manner.

Animals↗

PubMed2005

Operative endoscopy of the airway with the old-fashioned esophageal dilators.

Bronchial dilation is usually required to treat a number of disorders; the most frequent are complications after airway surgery, including lung transplantation, stenosis after radiotherapy, and compression by an extraluminal mass. The procedure is performed by forcing the tip of a rigid bronchoscope through the stenosis using barrels of increasing size; however, when there is a clear discrepancy between the caliber of the rigid instrument and the stenosis, the first step may be difficult. In such cases, we have successfully employed two types of old-fashioned esophageal dilators rescued from the armamentarium of our endoscopy unit.

Airway Obstruction↗

PubMed2004

Complete mechanical cervical anastomosis using a narrow gastric tube after esophagectomy for cancer.

OBJECTIVE: Fibrous stenosis of the esophagogastric cervical anastomosis remains a significant complication occurring in up to one-third of cases. Trying to reduce the incidence of this complication, we describe our technique of cervical esophagogastric anastomosis using endoscopic linear stapler which seems to reduce the incidence of fibrous stricture formation after resection of esophageal cancer. METHODS: Between March 2000 and June 2003, 26 patients (15 males and 11 females) underwent esophagectomy using tubulized stomach for reconstruction. Cervical esophagogastric anastomosis using linear endoscopic stapler was performed in all cases. The occurrence of post-operative anastomotic leak and development of anastomotic stricture were recorded and analyzed. RESULTS: All patients survived esophagectomy and were available for post-operative follow-up. Anastomotic leak developed in one case. No patient developed fibrous stenosis that required dilatation therapy. CONCLUSION: Complete mechanical esophagogastric anastomosis, using endoscopic linear stapler is effective and safe, even when a narrow gastric tube is used as esophageal substitute. This technique seems superior to other techniques to reduce the incidence of post-operative anastomotic complications.

Adult↗

PubMed2004

ADC mapping of neurodegeneration in the brainstem and cerebellum of patients with progressive ataxias.

Analysis of the apparent diffusion coefficient (ADC) maps derived from diffusion-weighted MR imaging is emerging as a reproducible, sensitive, and quantitative tool to evaluate brain damage in diseases of the white and gray matter. To explore the potentials of ADC maps analysis in degenerative ataxias, we examined 28 patients and 26 age-matched controls with T1, T2, and diffusion (b values 0-1000 along the three main body axes)-weighted MR images. Twenty-four patients had inherited genetically proven diseases including spinocerebellar ataxia type 1 (SCA1) (n = 9), spinocerebellar ataxia type 2 (SCA2) (n = 8), and Friedreich's ataxia (FA) (n = 7), whereas four patients had sporadic adult onset pure cerebellar ataxia (three idiopathic, one gluten intolerance). Area and linear measurements of the CNS structures contained in the posterior cranial fossa (PCF) preliminary enabled classification of the patients in the three morphological categories reflecting the gross pathology findings, namely olivopontocerebellar atrophy (OPCA) (n = 10: six SCA2 and four SCA1), spinal atrophy (SA) (n = 7: all FA), and cortical cerebellar atrophy (CCA) (n = 4: three idiopathic and one gluten intolerance). Seven patients with SCA1 (n = 5) or SCA2 (n = 2) had morphologic changes reminiscent of OPCA, but their values were still in the lower normal range and were classified as undefined. Mean diffusivity (D) maps of the entire brain were generated and D was measured with regions of interest (ROI) in the medulla, pons, middle cerebellar peduncles, and the peridentate white matter. Moreover, after exclusion of the skull with manual segmentation and of the CSF with application of a threshold value, histograms were obtained for D of the brainstem and cerebellum and for D of the cerebral hemispheres. As compared to controls, a (P < 0.001) increase of D was observed in the medulla, middle cerebellar peduncles, and peridentate white matter in OPCA and undefined patients groups who had also significantly increased values of the 25th and 50th percentiles in the brainstem and cerebellum D histogram. In CCA (P = 0.01), an increase of the 25th and 50th percentile of the D value was observed in the brainstem and cerebellum histograms. The SA group showed (P < 0.001) an increased D in the medulla only. A correlation between clinical severity as assessed with the Inherited Ataxias Clinical Rating Scale (IACRS) and the 50th percentile of the D value in the brainstem and cerebellum histogram (r = 0.69) was observed in patients with SCA1 or SCA2. Diffusion MR imaging reveals variable patterns of increase of D in the brainstem, cerebellum, and cerebral hemispheres in degenerative ataxias that match the known distribution of the neuropathological changes.

Adult↗

PubMed2003

Bilateral sequential lung transplantation without sternal division.

OBJECTIVES: The 'clamshell incision' is considered the standard approach for bilateral sequential lung transplantation (BSLT); however, a considerable morbidity may be related to this incision. The bilateral anterolateral thoracotomy without sternal division is an alternative approach that may contribute to avoid chest wall complications. METHODS: We have employed this approach in a prospective series of 34 patients undergoing bilateral transplantation (Group I). The results were retrospectively compared with an historical control group of 37 patients (Group II) undergoing transplantation through the clamshell incision. RESULTS: The operative time in Groups I and II were 228+/-32 and 293+/-37 min, respectively; the difference between the ischemic time of the first and second lungs were 68+/-20 and 73+/-15 min. Intensive care unit stay was 5+/-6 vs. 13+/-10 days and length of hospitalization was 25+/-16 vs. 32+/-10 days. Vital capacity measured 3 weeks after the transplant was significantly higher in Group I (65+/-13 vs. 45+/-8% predicted) as well as FEV(1) (71+/-8 vs. 58+/-7% predicted). No wound related complication was observed in Group I; in Group II, there were 17 chest wall complications: sternal osteomyelitis in three patients (surgical debridement and closure with a muscle flap), migration of the Kirshner wire in three (removal of the wire), sternal override in three (surgical correction) and prolonged pain in eight. CONCLUSIONS: The bilateral anterolateral thoracotomy without sternal splitting is a safe and effective approach for BSLT; it allows to avoid sternal complications and contributes to improve respiratory function in the early postoperative period.

Adolescent↗

PubMed2002

Synthesis and antiplatelet activity of gemfibrozil chiral analogues.

The chiral analogues of gemfibrozil 5-(2,5-dimethylphenoxy)-2-methylpentanoic acid and 5-(2,5-dimethylphenoxy)-2-ethylpentanoic acid were synthesized in optically active form using (S)-4-(1-methylethyl)-2-oxazolidinone as chiral auxiliary. All compounds inhibit human platelet aggregation. From these data, one can surmise that all tested compounds and gemfibrozil act at the platelet level with different mechanism than that of ASA, even if with a different potency.

Blood Platelets↗

PubMed2002

Whole brain apparent diffusion coefficient histogram: a new tool for evaluation of leukoaraiosis.

PURPOSE: To test whole brain apparent diffusion coefficient histogram analysis as an alternative approach to visual score for the assessment of leukoaraiosis (LA). MATERIALS AND METHODS: T2 and diffusion weighted images were obtained in 15 elderly patients. LA extension was assessed on T2 weighted images by two observers using a semiquantitative visual score. Apparent diffusion coefficient (ADC) maps of the entire brain were generated and, after exclusion of the skull with manual tracing and of the cerebrospinal fluid (CSF) by application of a threshold value, whole brain (WB)-ADC histogram was obtained. Moreover, a brain volume index (BVI) was calculated on ADC maps as (intracranial volume - CSF volume) /intracranial volume. RESULTS: The kappa inter-observer agreement for LA scoring was 0.69. Manual segmentation of the skull showed a mean inter-operator coefficient of variation below 3%. The median value of whole brain ADC histogram directly correlated with LA extension (P = 0.013). Moreover a significant inverse correlation (P = 0.002) was found between WB-ADC median value and BVI. CONCLUSION: WB-ADC histogram is a reproducible alternative tool for assessing LA extension and severity.

Aged↗

PubMed2002

Nd:YAG laser resection of lung cancer invading the airway as a bridge to surgery and palliative treatment.

BACKGROUND: Thirty percent of patients with lung cancer have airway obstruction requiring palliation. In addition, endoscopic resection may be considered before surgery or induction therapy to improve quality of life and functional status, and to allow better staging. It may also help to prevent infectious complications during induction chemotherapy. METHODS: Since 1993, 351 Nd:YAG laser resections were performed in 273 patients with lung cancer. The tumor involved the trachea in 36 patients, the carina in 28, the main bronchi in 154, the bronchus intermedius in 29, and the distal airway in 26. One hundred eight stents were placed. After the endoscopic treatment 36 patients were operated on (23 after induction chemotherapy) with 8 pneumonectomies (1 tracheal sleeve) and 28 lobectomies (15 bronchial sleeves). Spirometry, arterial blood gas analysis, and quality of life and performance status were recorded before and after laser treatment and after induction chemotherapy. Complications during chemotherapy, surgical morbidity and mortality, and survival were also recorded. RESULTS: Major complications during laser resection were bleeding (7 patients) and hypoxia (5 patients). Three patients died within 24 hours after the procedure. No complications were observed in the group of patients who subsequently underwent induction chemotherapy or surgery. One patient developed pneumonia during induction chemotherapy. The airway caliber improved in 89% of patients undergoing palliation only. In the group of patients undergoing induction chemotherapy and/or surgery, the performance status, quality of life, and functional measurements significantly improved after endoscopic treatment (FEV1 from 1.4 +/- 0.5 L/s to 2.2 +/- 0.6 L/s). Three-year survival after induction chemotherapy and surgery, was 52%. Median survival after palliation alone was 12.1 months. CONCLUSIONS: Nd:YAG laser resection is a safe and effective means of relieving airway obstruction. Before induction chemotherapy or surgery preliminary endoscopic palliation helps to improve evaluation and staging and contributes to reducing morbidity during chemotherapy without increasing surgical complications.

Airway Obstruction↗

PubMed2002

Bullectomy is comparable to lung volume reduction in patients with end-stage emphysema.

OBJECTIVES: Emphysema is one of the most prevalent disabling diseases, not modified by current medical treatment and physical rehabilitation. Lung transplantation is an effective clinical option in end-stage emphysema but it is available only for a limited number of patients. Bullectomy and lung volume reduction represent other surgical options to improve symptoms and exercise tolerance in selected patients. Both procedures allow the removal of the area of emphysematous lung resulting in improvement in chest wall mechanics, ventilation/perfusion ratio and re-expansion and better function of the residual lung. There is some evidence that in patients with end-stage emphysema bullectomy and lung volume reduction work in the same manner and yield similar functional results. METHODS: We compared and analyzed retrospectively two groups of patients with end-stage emphysema who underwent bullectomy or lung volume reduction. Over the last 5 years 20 patients with end-stage emphysema presenting with bullae underwent thoracoscopic bullectomy (Group I). During the same period of time 18 patients with end-stage non-bullous emphysema underwent thoracoscopic unilateral lung volume reduction. Pre-operative baseline respiratory function data, peri-operative data, and functional results recorded at 6 and 12 months were compared and analyzed. RESULTS: Both groups were homogeneous in terms of age, degree of respiratory derangement and severity of emphysema. Complication rate and peri-operative data were similar in the two groups. Improvement in symptoms, respiratory function and exercise tolerance was comparable. CONCLUSIONS: Our experience supports the hypothesis that the physiopathological basis of respiratory improvement after bullectomy and lung volume reduction surgery in patients with end-stage emphysema is the same, although the exact mechanism remains incompletely understood.

Aged↗