Noninvasive genetic population survey of snow leopards (Panthera uncia) in Kangchenjunga conservation area, Shey Phoksundo National Park and surrounding buffer zones of Nepal

<p>Abstract</p> <p>Background</p> <p>The endangered snow leopard is found throughout major mountain ranges of Central Asia, including the remote Himalayas. However, because of their elusive behavior, sparse distribution, and poor access to their habitat, there is a lack of reliable information on their population status and demography, particularly in Nepal. Therefore, we utilized noninvasive genetic techniques to conduct a preliminary snow leopard survey in two protected areas of Nepal.</p> <p>Results</p> <p>A total of 71 putative snow leopard scats were collected and analyzed from two different areas; Shey Phoksundo National Park (SPNP) in the west and Kangchanjunga Conservation Area (KCA) in the east. Nineteen (27%) scats were genetically identified as snow leopards, and 10 (53%) of these were successfully genotyped at 6 microsatellite loci. Two samples showed identical genotype profiles indicating a total of 9 individual snow leopards. Four individual snow leopards were identified in SPNP (1 male and 3 females) and five (2 males and 3 females) in KCA.</p> <p>Conclusions</p> <p>We were able to confirm the occurrence of snow leopards in both study areas and determine the minimum number present. This information can be used to design more in-depth population surveys that will enable estimation of snow leopard population abundance at these sites.</p

Outcome of craniofacial surgery in children and adolescents with malignant tumors involving the skull base: An international collaborative study

Background. The aim of the study was to characterize the distribution of anterior skull base (ASB) cancers in the pediatric population and to identify predictors of outcome. Methods. This was an international study of 1307 patients undergoing craniofacial surgery for malignant tumors; 6.4% (n = 84) among these were ≤21 years old. Results. The most common histologic type was sarcoma (40%), followed by squamous cell carcinoma (14%). Higher incidence of tumors was found in older children (7.5-21 years) compared to younger children. The 5-year disease-specific and overall survival rates were 61% and 55%, respectively (median follow-up of 30 months). The best prognosis was associated with low-grade sarcomas and the worst with salivary and squamous cell carcinomas. High-grade sarcoma represented an intermediate risk group. On multivariate analysis, prior radiotherapy and histology were independent predictors of survival. Conclusion. Surgery for malignant tumors involving the ASB is feasible and safe in children. Histology is significant determinant of poor outcome in this population. © 2008 Wiley Periodicals, Inc.link_to_subscribed_fulltex

Complications of craniofacial resection for malignant tumors of the skull base: Report of an international collaborative study

Background. Advances in imaging, surgical technique, and perioperative care have made craniofacial resection (CFR) an effective and safe option for treating malignant tumors involving the skull base. The procedure does, however, have complications. Because of the relative rarity of these tumors, most existing data on postoperative complications come from individual reports of relatively small series of patients. This international collaborative report examines a large cohort of patients accumulated from multiple institutions with the aim of identifying patient-related and tumor-related predictors of postoperative morbidity and mortality and set a benchmark for future studies. Methods. One thousand one hundred ninety-three patients from 17 institutions were analyzed for postoperative mortality and complications. Postoperative complications were classified into systemic, wound, central nervous system (CNS), and orbit. Statistical analyses were carried out in relation to patient characteristics, extent of disease, prior radiation treatment, and type of reconstruction to determine factors that predicted mortality or complications. Results. Postoperative mortality occurred in 56 patients (4.7%). The presence of medical comorbidity was the only independent predictor of mortality. Postoperative complications occurred in 433 patients (36.3%). Wound complications occurred in 237 (19.8%), CNS-related complications in 193 (16.2%), orbital complications in 20 (1.7%), and systemic complications in 57 (4.8%) patients. Medical comorbidity, prior radiation therapy, and the extent of intracranial tumour involvement were independent predictors of postoperative complications. Conclusions. CFR is a safe surgical treatment for malignant tumors of the skull base, with an overall mortality of 4.7% and complication rate of 36.3%. The impact of medical comorbidity and intracranial tumor extent should be carefully considered when planning therapy for patients whose tumors are amenable to CFR. © 2005 Wiley Periodicals, Inc.link_to_subscribed_fulltex

Craniofacial surgery for malignant skull base tumors: Report of an international collaborative study

BACKGROUND. Malignant tumors of the skull base are rare. Therefore, no single center treats enough patients to accumulate significant numbers for meaningful analysis of outcomes after craniofacial surgery (CFS). The current report was based on a large cohort that was analyzed retrospectively by an International Collaborative Study Group. METHODS. One thousand three hundred seven patients who underwent CFS in 17 institutions were analyzable for outcome. The median age was 54 years (range, 1-98 years). Definitive treatment prior to CFS had been administered in 59% of patients and included radiotherapy in 367 patients (28%), chemotherapy in 151 patients (12%), and surgery in 523 patients (40%). The majority of tumors (87%) involved the anterior cranial fossa. Squamous cell carcinoma (29%) and adenocarcinoma (16%) were the most common histologic types. The margins of surgical resection were reported close/ positive in 412 patients (32%). Adjuvant postoperative radiotherapy was received by 510 patients (39%), and chemotherapy was received by 57 patients (4%). RESULTS. Postoperative complications were reported in 433 patients (33%), with local wound complications the most common (18%). The postoperative mortality rate was 4%. With a median follow-up of 25 months, the 5-year overall, disease-specific, and recurrence-free survival rates were 54%, 60%, and 53%, respectively. The histology of the primary tumor, its intracranial extent, and the status of surgical margins were independent predictors of overall, disease-specific, and recurrence-free survival on multivariate analysis. CONCLUSIONS. CFS is a safe and effective treatment option for patients with malignant tumors of the skull base. The histology of the primary tumor, its intracranial extent, and the status of surgical margins are independent determinants of outcome. © 2003 American Cancel' Society.link_to_subscribed_fulltex

Craniofacial resection for malignant melanoma of the skull base: Report of an International Collaborative Study

Objective: To report postoperative mortality, complications, and outcomes in a subset of patients with the histologic diagnosis of malignant melanoma extracted from an existing database of a large cohort of patients accumulated from multiple institutions. Design: Retrospective outcome analysis. Setting: Seventeen international tertiary referral centers performing craniofacial surgery for malignant skull base tumors. Patients: A total of 53 patients were identified from a database of 1307 patients who had craniofacial resection for malignant tumors at 17 institutions. The median age was 63 years. Of the 53 patients, 25 (47%) had had prior single modality or combined treatment, which included surgery in 22 (42%), radiation in 11 (21%), and chemotherapy in 2 (4%). The margins of resection were close or microscopically positive in 7 (13%). Adjuvant radiotherapy was given in 22 (42%), chemotherapy in 3 (6%), and vaccine or interferon therapy in 2 (4%). Complications were classified into overall, local, central nervous system, systemic, and orbital. Overall survival (OS), disease-specific survival (DSS), and recurrence-free survival (RFS) were determined using the Kaplan-Meier method. Predictors of outcome were identified by multivariate analysis. Results: Postoperative mortality occurred in 3 patients (6%) and postoperative complications were reported in 14 patients (26%). Local wound complications occurred in 6 patients (11%), central nervous system in 7 (13%), systemic in 3 (6%), and orbital in 1 (2%).With a median follow-up of 10 months (range, 1-159 months), the 3-year OS, DSS, and RFS rates were 28.2%, 29.7%, and 25.5%, respectively. The extent of orbital involvement and adjuvant postoperative radiation therapy (PORT) were independent predictors of DSS and OS on multivariate analysis, whereas only PORT was an independent predictor of RFS. Patients treated with PORT had significantly better 3-year OS (39% vs 18%; relative risk, 2.9; P=.007), DSS (41% vs 19%; relative risk, 3.0; P=.007), and RFS (39% vs 15%; relative risk, 4.2; P=.001). Conclusions: Craniofacial resection in patients with malignant melanoma of the skull base has mortality (6%) and complication rates (26%) comparable to other malignant tumors of the skull base. However, malignant melanoma is associated with a much poorer OS, DSS, and RFS. Adjuvant PORT correlated with improved 3-year OS, DSS, and RFS on multivariate analysis. These factors must be taken into account when considering craniofacial resection in a patient with malignant melanoma invading the skull base. ©2006 American Medical Association. All rights reserved.link_to_subscribed_fulltex

Craniofacial resection for malignant paranasal sinus tumors: Report of an international collaborative study

Background. Malignant tumors of the superior sinonasal vault are rare, and, because of this and the varied histologic findings, most outcomes data reflect the experience of small patient cohorts. This International Collaborative study examines a large cohort of patients accumulated from multiple institutions experienced in craniofacial surgery, with the aim of reporting benchmark figures for outcomes and identifying patient-related and tumor-related predictors of prognosis after craniofacial resection (CFR). Methods. Three hundred thirty-four patients from 17 institutions were analyzed for outcome. Patients with esthesioneuroblastoma were excluded and are being reported separately. The median age was 57 years (range, 3-98 years). One hundred eighty-eight patients (56.3%) had had prior single-modality or combined treatment, which included surgery in 120 (36%), radiation in 79 (23.7%), and chemotherapy in 56 (16.8%). The most common histologic findings were adenocarcinoma in 107 (32%) and squamous cell carcinoma in 101 (30.2%). The margins of resection were close or microscopically positive in 95 (30%). Adjuvant radiotherapy was given in 161 (48.2%) and chemotherapy in 16 (4.8%). Statistical analyses for outcomes were performed in relation to patient characteristics, tumor characteristics, including histologic findings and extent of disease surgical resection margins, prior radiation, and prior chemotherapy to determine predictive factors. Results. Postoperative mortality occurred in 15 patients (4.5%). Postoperative complications occurred in 110 patients (32.9%). The 5-year overall, disease-specific, and recurrence-free survival rates were 48.3%, 53.3%, and 45.8%, respectively The status of surgical margins, histologic findings of the primary tumor, and intracranial extent were independent predictors of overall, disease-specific, and recurrence-free survival on multivariate analysis. Conclusions. CFR for malignant paranasal sinus tumors is a safe surgical treatment with an overall mortality of 4.5% and complication rate of 33%. The status of surgical margins, histologic findings of the primary tumor, and intracranial extent are independent predictors of outcome. © 2005 Wiley Periodicals, Inc.link_to_subscribed_fulltex

Craniofacial surgery for nonmelanoma skin malignancy: Report of an international collaborative study

Background. This study examined the efficacy of craniofacial surgery (CFS) in treating locally advanced nonmelanoma skin cancer (NMSC). Methods. One hundred twenty patients who underwent CFS for NMSC were identified from 17 participating institutions. Patient, tumor, and treatment information was analyzed for prognostic impact on survival. Results. Surgical margins were negative in 74%, close in 3%, and involved in 23% of patients. Complications occurred in 35% of patients, half of which were local wound problems. Operative mortality was 4%. Median follow-up interval after CFS was 27 months. The 5-year overall survival (OS), disease-specific survival (DSS), and recurrence-free survival (RFS) rates were 64%, 75%, and 60%, respectively. Squamous cell histology, brain invasion, and positive resection margins independently predicted worse OS, DSS, and RFS. Conclusion. CFS is an effective treatment for patients with NMSC invading the skull base. Histology, extent of disease, and resection margins are the most significant predictors of outcome. © 2007 Wiley Periodicals, Inc.link_to_subscribed_fulltex