EELS: Autonomous snake-like robot with task and motion planning capabilities for ice world exploration.

Ice worlds are at the forefront of astrobiological interest because of the evidence of subsurface oceans. Enceladus in particular is unique among the icy moons because there are known vent systems that are likely connected to a subsurface ocean, through which the ocean water is ejected to space. An existing study has shown that sending small robots into the vents and directly sampling the ocean water is likely possible. To enable such a mission, NASA's Jet Propulsion Laboratory is developing a snake-like robot called Exobiology Extant Life Surveyor (EELS) that can navigate Enceladus' extreme surface and descend an erupting vent to capture unaltered liquid samples and potentially reach the ocean. However, navigating to and through Enceladus' environment is challenging: Because of the limitations of existing orbital reconnaissance, there is substantial uncertainty with respect to its geometry and the physical properties of the surface/vents; communication is limited, which requires highly autonomous robots to execute the mission with limited human supervision. Here, we provide an overview of the EELS project and its development effort to create a risk-aware autonomous robot to navigate these extreme ice terrains/environments. We describe the robot's architecture and the technical challenges to navigate and sense the icy environment safely and effectively. We focus on the challenges related to surface mobility, task and motion planning under uncertainty, and risk quantification. We provide initial results on mobility and risk-aware task and motion planning from field tests and simulated scenarios.

High coexpression of both insulin-like growth factor receptor-1 (IGFR-1) and epidermal growth factor receptor (EGFR) is associated with shorter disease-free survival in resected non-small-cell lung cancer patients.

BACKGROUND: Insulin-like growth factor receptor-1 (IGFR-1) represents a novel molecular target in non-small-cell lung cancer (NSCLC). IGFR-1 and epidermal growth factor receptor (EGFR) activation is essential to mediate tumor cell survival, proliferation and invasion. We explored the correlation between IGFR-1 and EGFR, their relationship with clinicopathological parameters and their impact on outcome in resected stage I-III NSCLC patients. PATIENTS AND METHODS: Tumors from 125 surgical NSCLC patients were evaluated for IGFR-1 and EGFR expression by immunohistochemistry. Kaplan-Meier estimates of survival and time to recurrence were calculated for clinical variables and biologic markers using the Cox model for multivariate analysis. RESULTS: IGFR-1 protein overexpression was detected in 36.0% of NSCLC patients and was associated with larger tumor size (P = 0.04) but not with other clinical or biological characteristics. EGFR protein overexpression was observed in 55.2% of NSCLC, more frequently in squamous cell carcinoma (SCC) than non-SCC (63.7% versus 36.3%, chi(2) = 9.8, P = 0.001). IGFR-1 protein expression was associated with EGFR protein expression (P = 0.03). At the multivariate analysis, high coexpression of both IGFR-1 and EGFR was a significant prognostic factor of worse disease-free survival (DFS) (hazard ratio 2.51, P = 0.01). CONCLUSION: A statistically significant association was observed between high coexpression of both IGFR-1 and EGFR and worse DFS in early NSCLC patients.

[Surgical treatment of well differentiated neuroendocrine tumours of the lung]. / Terapia chirurgica dei tumori neuroendocrini ben differenziati del polmone.

The bronchial tree represents the most frequent site of origin of carcinoids (around 25% of the total). The spectrum of differentiation of lung neuroendocrine tumors ranges from low-malignancy (carcinoids) to highly aggressive forms (small cell lung carcinoma) Diagnostic and therapeutic strategies therefore vary greatly. In well differentiated tumors (carcinoids) signs and symptoms are related to the airways obstruction in central forms, while peripheral forms are mostly discovered accidentally if asymptomatic. Clinical or subclinical paraneoplastic syndromes are associated in a minority of cases. Diagnostic work-up includes CT multislice, bronchial endoscopy and Octreoscan with chest Single Photon Emission Computed Tomography (SPECT). Further contribute may be added by the (68), Ga-DOTA-D-Phe(1)-Tyr(3)-ocreotide (DOTATOC) and 5-hydroxytryptophan (5-HTP) PET-CT, at present available only in a few centres, and by endobronchial ultrasound (EBUS), fluorescence bronchoscopy and virtual bronchoscopy. Surgery is the treatment of choice, while medical therapy is useful to treat the hypersecretion in paraneoplastic syndromes and to control tumor proliferation in metastatic or/and inoperable disease.

Epidemiology of non-gastroenteropancreatic (neuro)endocrine tumours.

The widespread availability and reliability of immunohistochemical techniques in the last three decades have allowed researchers to identify cells with common neuroendocrine markers in virtually every organ. As a whole, these neuroendocrine cells form the so-called diffuse neuroendocrine system. Tumours arising from the cells of the diffuse neuroendocrine system are defined as (neuro)endocrine tumours (NETs). NETs have been increasingly described in recent years. However, despite the increase in the number of published papers focused on NET, we still lack adequate epidemiological data, particularly for non-gastroenteropancreatic (GEP) NETs. Furthermore, the real incidence of neuroendocrine differentiation for most sites is not completely known and is probably underestimated. As a consequence, data on the clinical features of many NET subgroups are not well known or confusing. For all of these reasons, we have attempted to evaluate the epidemiology of non-GEP NETs, reviewing the limited data available in the literature.

Thymic neuroendocrine carcinoma (carcinoid) in multiple endocrine neoplasia type 1 syndrome: the Italian series.

Neuroendocrine tumors may occur in the setting of multiple endocrine neoplasia type 1 (MEN1) syndrome. Among these, a probably underestimated prevalence of well differentiated neuroendocrine thymic carcinoma (carcinoid), a neoplasm characterized by very aggressive behavior, has been described. We report characterization of the seven Italian cases in which this association occurred among a series of 221 MEN1 patients (41 sporadic and 180 familial cases; prevalence, 3.1%). All of the patients were male, and six of seven (85%) were heavy smokers. No associated hormonal hypersecretion was detected. The first diagnosis was between the second and fifth decades. Familial clusters were present in three of seven (42.8%). No genotype-phenotype correlation was found. All seven cases were associated with hyperparathyroidism. In one patient, prophylactic thymectomy revealed a small nodular lesion suggestive of a thymic carcinoid, providing evidence that preventive thymectomy might prevent additional growth of an occult thymic carcinoid. These findings confirm that thymic carcinoids are associated with a very high lethality, with a near-total prevalence in smoker males. Therefore, prophylactic thymectomy should be considered at neck surgery for primary hyperparathyroidism in MEN1 male patients, especially for smokers, and, due to the frequent familial clusters distribution of this pathology, in subjects with affected relatives presenting this feature. Thus, we recommend screening every patient affected with a neuroendocrine thymic neoplasm for MEN1 syndrome.

Clinical significance of serum gastrin levels in patients with colorectal cancer.

AIMS: An association between elevated serum gastrin levels and the presence of human colorectal cancer has been reported, and gastrin has been shown to stimulate the growth of experimentally induced colon neoplasia. The aim of this study was to determine the preoperative and postoperative concentrations of serum gastrin in 53 patients with colorectal cancer and to assess the correlation between gastrin levels and tumor characteristics and prognosis. MATERIALS AND METHODS: A prospective study was performed over a six-year period during which 53 patients received potentially curative surgery for colorectal cancer. The prognostic variables used for the analysis included age, sex, tumor site, stage and degree of differentiation, preoperative and postoperative serum values of carcinoembryonic antigen (CEA) and gastrin, cancer-related mortality, and survival. CEA and gastrin serum values were determined using radioimmunological methods. Follow-up was carried out with clinical and radiological tests. RESULTS: The mean preoperative gastrin concentration was 51.2+/-27.4 pg/mL (range 12-146). Significantly increased serum gastrin concentrations, which returned to normal after surgery, were detected only in patients with well-differentiated cancer (74.2+/-28.3 pg/mL; moderately differentiated, 52.1+/-23.8; poorly differentiated, 29.9+/-12.3, p=0.02). The prognosis was unrelated to serum gastrin level; instead, tumor stage, preoperative CEA value, and degree of differentiation affected patient survival. CONCLUSIONS: This study showed that the serum gastrin concentration is not an appropriate clinical oncogenic factor. Although occurring only in well-differentiated tumors, serum gastrin is unrelated to the prognosis of patients with colorectal cancer.

[Use of the Dynamic Stent in the palliation of carinal and distal tracheal stenosis]. / Impiego del Dynamic Stent nella palliazione delle lesioni della carena e dell'estremo distale della trachea.

Satisfactory palliation of the lesions involving the carinal region is difficult to achieve because the stenting is conducted in an unsuitable anatomy, in highly symptomatic patients. During the period 1987-2000 we performed 785 operative rigid bronchoscopies in 524 patients, 184 of whom received a respiratory stent. The stenting of the carinal region was carried out in 27 patients with the use of the Frietag Dynamic stent. In this group of patients indication for stenting was as follows:--advanced lung cancer (22);--esophageal cancer invading the lower trachea (1);--severe tracheobronchomalacia (2);--postintubation stenosis of the lower trachea (2). No perioperative mortality was observed. All patients experienced symptomatic improvement. Follow-up ranged from 1 to 60 months: all neoplastic patients died for advanced disease without significant respiratory problems with a median survival of 5.6 months; three patients treated for benign diseases are still alive at 2, 31 and 65 months from stent deployment. No major complications were observed: in two patients the stent was removed after few days due to mucous retention; furthermore we observed symptomatic respiratory infections caused by a residual space between the tracheal wall and the prosthesis in other two patients with severe COPD. Dynamic stent is to be considered the stent of choice for palliation of the carinal region because it is effective and well tolerated with a low complications rate. The main limitations of such prosthesis are the shortness of the right bronchial branch and the size, sometimes inadequate.

Preservation of the inferior mesenteric artery in colorectal resection for complicated diverticular disease.

BACKGROUND: Preservation of the inferior mesenteric artery (IMA) and consequential blood flow to the rectum would reduce the risk of leakage of a colorectal anastomosis. METHODS: One hundred and sixty-three patients undergoing left colectomy for complicated diverticular disease of the colon were randomly placed into two groups: A, n = 86; and B, n = 77. In group A, the integrity of the IMA was preserved by artery skeletization (IMAS); in group B, the IMA was divided at its origin. Variables recorded included duration of the surgical procedure, need for blood transfusion, length of hospital stay, operative mortality and morbidity, staple-ring disruption, and radiologic and clinical leakage. Anastomotic stenosis and recurrence of diverticular disease were noted. RESULTS: Surgical time was superior in the IMAS group. Radiologic and clinical leakages were significantly higher in group B (P = 0.02, P = 0.03, respectively). In group A a significant lower number of staple-ring disruptions was observed, evolving into clinical dehiscence. CONCLUSION: Preserving the natural blood supply to the rectum and the ensuing use of a healthy well-nourished rectal stump are suggested as the main aspects of IMAS in preventing and healing leakage of colorectal anastomosis.

[The role of surgery in the treatment of small cell lung cancer]. / Ruolo della chirurgia nel trattamento del microcitoma polmonare.

Small cell lung cancer (SCLC) is a biologically aggressive tumor with a low long-term survival rate. SCLC is highly responsive to chemotherapy and surgery has a very limited role in its treatment because the disease is usually widely disseminated at the diagnosis. Good results from surgery have been reported in the small subgroup of T1-2 N0 M0 patients. In N1 peripheral SCLC, surgery in combination with other treatments, can obtain fair results. Surgical treatment does not influence the prognosis in SCLC as stage III and IV.

The role of silicone stents in the treatment of cicatricial tracheal stenoses.

OBJECTIVE: Tracheal stenting for cicatricial stenoses is reserved for patients whose lesions are deemed inoperable for local or general reasons. The aim of our study was to verify the long-term results of silicone tracheal stents in such a clinical setting. METHODS: Clinical data of 45 patients treated by tracheal silicone stents, between 1987 and 1999, were reviewed. All patients had highly symptomatic cicatricial stenoses; they were selected for stenting rather than for surgery because of local and general conditions. This series has been divided in two groups according to the purpose of stenting: bridge to surgery or definitive treatment. Follow-up ranged between 12 and 83 months. Twenty-seven patients received a Montgomery T tube (Hood Laboratories, Pembroke, Mass), 16 a Dumon stent (Novatech, Plan de Gras, France), and 2 a Dynamic stent (Rusch, Kernen, Germany). RESULTS: No procedure-related mortality was observed. Nine patients underwent curative resection and reconstruction after a variable stenting period; one had a recurrent stenosis and was treated for palliation with a T tube. Tracheal stenting was performed for palliation as a definitive treatment in 37 patients. Among this group, 11 patients died of unrelated causes at a median of 10 months after the endoscopic treatment. The stent was permanently removed in 10 after a median interval of 32 months (range 9-70 months); in 4 others, symptomatic recurrence of the stenosis was observed within 6 weeks of stent removal. None of the patients successfully decannulated had a completely normal tracheal lumen but all remained asymptomatic because the residual stenosis was mild or well tolerated for concomitant limitation of physical activity. CONCLUSIONS: Long-term treatment with a silicone stent was safe and well tolerated in cicatricial tracheal stenoses. This procedure can be considered as a bridge to curative surgery or as a definitive treatment. The latter, generally performed for palliation, may provide satisfactory therapeutic results in selected patients, even in the presence of severe circumferential stenoses.

Long-term safety and tolerance of silicone and self-expandable airway stents: an experimental study.

BACKGROUND: A variety of respiratory stents are currently available, but the ideal airway prosthesis seems far from being recognized. The objective of this study was to verify safety and long-term effect on the bronchial wall of three different types of airway stents. METHODS: Twelve healthy adult sheep were divided in three groups, scheduled to receive: (1) bare self-expandable metallic stents (Gianturco); (2) silicone stents (Dumon); and (3) covered self-expandable synthetic stents (Polyflex). Insertions were performed through a rigid bronchoscope under general anesthesia. Chest roentgenogram was performed 1 and 6 months after surgery, and flexible bronchoscopy after 6 months. Twelve months postoperatively, the animals were killed and a postmortem examination was carried out. RESULTS: All Polyflex stents migrated during the observation period; one late migration was observed in the Dumon group. Microscopic study showed: (1) Gianturco stents: full-thickness perforation of the bronchial wall covered by a thick layer of a chronic inflammatory infiltrate. Infection by Candida at the bottom of some ulcerations; (2) Dumon stents: mild bronchial inflammation (squamous metaplasia, submucosal inflammatory infiltrates; granuloma-like infiltrates). In case of displacement, no significant changes of the previously stented bronchus occurred; and (3) Polyflex stents: no changes of the previously stented bronchi. CONCLUSIONS: Gianturco stents proved unsafe in the long term, owing to the risk of severe airway wall damage. The Polyflex stent is well tolerated but presents a high migration rate. Silicone stents show several limitations but appear to be well tolerated by the host mucosa.

[Conservative surgery in the treatment of rectal tumors. Our experience, 1986-1997]. / La chirurgia conservativa nel trattamento dei tumori del retto. Nostra esperienza 1986-1997.

OBJECTIVE: Our institution's experience with low anterior resection for primary rectal cancer was reviewed to determine cancer treatment results and to identify risk factors for pelvic recurrence. METHODS: Ninety-two patients treated for primary rectal cancer between 1986 and 1997 were studied retrospectively. All cases was classified according to Astler-Coller. Median follow up was 46 months. RESULTS: Actuarial 5-year survival for all patients was 79%. Among 28 patients who relapsed, only 9 pelvic recurrence was detected with an actuarial rate of 15% at 5 years. Lymph nodes involvement were associated with increased risk for pelvic recurrence. DISCUSSION: Low anterior resection permitted by circular stapler provides good treatment for mid-rectal cancers and for some distal rectal cancers. Pelvic recurrence is not correlated with neoplasm localization, T stage and short distal resection margins, but only with the presence of lymph nodes involvement. This result increase the value of the hypothesis that search the pelvic recurrence origin in a extra-parietal disease respect anastomotic disease. CONCLUSION: Fundamental to prevent pelvic recurrence is the surgical technique that have to remove lymph node en bloc with the rectum doing a dissection along the endopelvic fascia to Denonvillers fascia so to take away completely the mesorectum.

Resection with curative intent after endoscopic treatment of airway obstruction.

BACKGROUND: Endoscopic treatment of malignant central airway obstructions usually is done for palliation. The exact role of such a procedure as preparatory to operation remains controversial. METHODS: From 1987 through 1996, 24 patients at our institution underwent tracheobronchial pulmonary resection after preliminary endoscopic treatment. During the same period, 304 patients underwent 449 operative rigid bronchoscopies for airway obstructions, most involving the use of a neodymium:yttrium-aluminum-garnet laser. The indications for operation were squamous cell carcinoma in 14 patients, bronchial gland tumors in 8 patients, and papillary thyroid cancer infiltrating the trachea in 2 patients. The total resection rate was 9.5% (5% for squamous cell carcinoma, 75% for low-grade malignant bronchial tumors, and 75% for papillary thyroid cancer). The median period between operative rigid bronchoscopy and operation was 18 days. RESULTS: No complications were observed after endoscopic treatment. There were two perioperative deaths (adult respiratory distress syndrome after carinal resection and pulmonary embolism after pneumonectomy) and one major complication (poor postoperative pulmonary function after pneumonectomy). No anastomotic complications were observed in the tracheobronchoplastic procedures. Follow-up was possible in every patient but 1: 6 patients died at a median of 30.5 months after operation (range, 3 to 46 months), 2 patients are alive with disease, and the rest are alive without evidence of disease at a median of 21 months (range, 2 to 61 months). CONCLUSIONS: Most patients who require endoscopic therapy for malignant airway obstructions are not candidates for operative resection. Preliminary endoscopic relief of obstruction can increase operability and improve surgical results in a highly selected group of patients.

Bone heterograft for chest wall reconstruction after sternal resection.

BACKGROUND: Experimental and clinical results of chest-wall reconstruction with bone heterograft after sternectomy are reported. METHODS: Seven dogs underwent subtotal or total sternectomy and reconstruction by implantation of a cortico-spongy bone heterograft sandwiched between two layers of a reabsorbable mesh. RESULTS: No major postoperative complications were observed. The implant has shown favorable mechanical and biological properties. Six and 9 months after operation all animals were sacrificed and pathologic examination showed good incorporation of the implanted bone with only partial resorption of its spongiosa. Subsequently, 2 patients underwent sternal resection with different indications and reconstruction was achieved by the technique developed experimentally. No complications were observed. Excellent immediate chest-wall stabilization was obtained, persisting for a follow-up period longer than 6 months. CONCLUSIONS: In comparison with autologous bone, sterile bone heterograft seems to offer the same mechanical properties with a significantly reduced surgical trauma.

Chest wall stabilization with synthetic reabsorbable material.

Experimental results and preliminary clinical experience with synthetic reabsorbable materials in chest wall reconstruction are reported. Six beagle dogs underwent chest wall resection involving three or four consecutive ribs. Reparative procedure was performed by construction of a polydioxanone-band grid, anchored to the adjacent undamaged ribs. A mild wound infection developed in 1 animal but resolved without rejection of the prosthesis. The experimental material has shown favorable properties, both mechanical and biological. Subsequently, 11 patients, with different indications, underwent reconstructive procedures of the chest wall with reabsorbable prostheses. No complications have occurred. Long-term stability was excellent in all patients, with a mean follow-up longer than 6 months. The advantages of reabsorbable compounds are pointed out along with the possible applications for chest wall reconstruction after chest wall resection.

[Surgery of pulmonary and hepatic metastases]. / Chirurgia delle metastasi polmonari ed epatiche.

In recent years surgery for hepatic and pulmonary metastases has been undertaken with a curative intent in a growing percentage of cases. In the present study the Authors evaluate their own experience in such a field, and summarize the state of the art, as it appears from a review of the international literature. At present, the subject is not settled, as several aspects are matter of debate (prognostic significance of free interval, tumor doubling time, number and location of metastatic lesions, histologic type, and stage, of the primary tumor, approach to synchronous metastases, accuracy of preoperative diagnosis), with different therapeutic implications according to the hepatic or pulmonary site. Pulmonary metastases should be managed by resection through a median sternotomy, in order to allow thorough exploration of both lungs. Hepatic lesions (from colorectal primaries) should be resected with a free margin not less than 1-2 cm. The need for uniformity of selection criteria and for the establishment of protocols including adjuvant therapy is strongly felt.

Mucinous cystadenoma occurring in heterotopic pancreatic tissue. A case report.

The first known case of mucinous cystadenoma occurring in heterotopic pancreatic tissue is described. Histogenesis, clinical behaviour, diagnostic and therapeutic problems of such tumor are analyzed as well as the endocrine and associated neoplastic diseases.

Synthetic prostheses in repair of chest wall defects after exeresis of malignancies.

Five cases of chest wall repair with synthetic prostheses following thoracectomy for malignant tumours are reported. Two patients were submitted to partial sternal resection (manubrium); in the first case Marlex mesh alone and in the second a composite graft with Methyl-methacrylate were used. The remaining cases underwent extended thoracectomy and reconstructive procedure based upon Marlex prosthetic replacement and myoplasty. No postoperative complications were observed and satisfactory stabilization of the chest wall with good cosmetic results were obtained.

Lung cancer: long-term survival after surgical treatment.

The authors have carried out an analysis on a series of 1802 patients with lung cancer. 1254 patients were considered operable (69.5%) and 828 were resected. Overall 5-year survival rate was 28.3%. Results of surgical treatment were analysed in relation to the specific features both of primary tumour and the host organism. Although patients affected with epidermoid carcinoma showed a better survival as compared to those affected with tumours of other histotypes. Conversely long-term results were significantly related to post-surgical stage. Patients treated for stage I tumour showed a significantly better long-term survival (5-year survival rate 48.2%) as compared to those undergone resection for stage II and III neoplasms (22.8% and 12%, respectively; p: less than 0.001). From the prognostic standpoint female patients undergone resection showed markedly lower long-term survival (5-year survival rate 12.5%) as compared to male patients (5-year survival rate 29.5%), but the numerical differences between the two groups of patients does not permit to detect statistically significant differences (P: less than 0.05). Type and intensity of the immune response affect significantly long-term survival.