Poor Survival Rates (poor + survival_rate)

Distribution by Scientific Domains


Selected Abstracts


Survival of mycobacterial species in aerosols generated from artificial saliva

LETTERS IN APPLIED MICROBIOLOGY, Issue 3 2000
M.S. Lever
Tuberculosis is transmitted primarily by the aerosol route and the aim of this study was to measure the ability of pathogenic mycobacteria to survive in aerosols generated from artificial saliva. Aerosols of Mycobacterium avium, Mycobacterium intracellulare and Mycobacterium tuberculosis were generated and maintained in air under controlled conditions using a Henderson apparatus and a rotating drum. There were no differences in aerosol survival between the three species, and all had a poor survival rate over a period of 1 h. These data confirm epidemiological studies that close and prolonged contact with a TB patient is required for transmission of infection. [source]


The future of stock enhancements: lessons for hatchery practice from conservation biology

FISH AND FISHERIES, Issue 2 2002
Culum Brown
Abstract The world's fish species are under threat from habitat degradation and over-exploitation. In many instances, attempts to bolster stocks have been made by rearing fish in hatcheries and releasing them into the wild. Fisheries restocking programmes have primarily headed these attempts. However, a substantial number of endangered species recovery programmes also rely on the release of hatchery-reared individuals to ensure long-term population viability. Fisheries scientists have known about the behavioural deficits displayed by hatchery-reared fish and the resultant poor survival rates in the wild for over a century. Whilst there remain considerable gaps in our knowledge about the exact causes of post-release mortality, or their relative contributions, it is clear that significant improvements could be made by rethinking the ways in which hatchery fish are reared, prepared for release and eventually liberated. We emphasize that the focus of fisheries research must now shift from husbandry to improving post-release behavioural performance. In this paper we take a leaf out of the conservation biology literature, paying particular attention to the recent developments in reintroduction biology. Conservation reintroduction techniques including environmental enrichment, life-skills training, and soft release protocols are reviewed and we reflect on their application to fisheries restocking programmes. It emerges that many of the methods examined could be implemented by hatcheries with relative ease and could potentially provide large increases in the probability of survival of hatchery-reared fish. Several of the necessary measures need not be time-consuming or expensive and many could be applied at the hatchery level without any further experimentation. [source]


Disease control, survival, and functional outcome after multimodal treatment for advanced-stage tongue base cancer

HEAD & NECK: JOURNAL FOR THE SCIENCES & SPECIALTIES OF THE HEAD AND NECK, Issue 7 2004
James P. Malone MD
Abstract Background. Surgical resection and postoperative radiation for advanced-stage malignancies of the oral cavity, oropharynx, and hypopharynx result in a dismal overall survival of 38%. Patients with carcinoma of the tongue base frequently have advanced disease at the time of presentation, and combined-modality therapy is usually required to achieve cure. Because of the poor survival rates with advanced malignancies with standard therapy, new and innovative approaches continue to be developed in an attempt to have a greater impact on disease control, patient survival, and functional outcome after therapy. This study examines functional outcome, survival, and disease control in patients receiving an intensified treatment regimen with concomitant chemoradiotherapy, surgery, and intraoperative radiotherapy for previously untreated, resectable, stage III and IV squamous cell carcinoma (SCC) of the tongue base. Methods. Forty patients with previously untreated, resectable, stage III and IV squamous cell carcinoma of the tongue base were treated in one of three sequential phase II intensification regimens (IRs). Treatment consisted of perioperative, hyperfractionated radiotherapy (9.1 Gy) with concurrent cisplatin followed by surgical resection with intraoperative radiotherapy boost (7.5 Gy). Postoperative treatment involved concurrent chemoradiotherapy (40 Gy to the primary site and upper neck and 45 Gy to the supraclavicular areas) with cisplatin with or without paclitaxel. Locoregional and distant disease control, 2-year overall, and disease-specific survival rates were calculated. The Performance Status Scale (PSS) for Head and Neck Cancer Patients was administered to 25 of the surviving patients. The effects of the method of surgical reconstruction, surgery involving the mandible and/or larynx, and early versus advanced T stage on PSS score were evaluated with the Wilcoxon rank-sum test. Results. Median follow-up in months for IR1, IR2, and IR3 were 83.6, 75.2, and 26.8. The locoregional control rate was 100%, and the rate of distant metastases was 7.5% for all patients. Two-year overall and disease-specific survival rates for the entire study population were 74.7% and 93.6%, respectively. Mean PSS scores by subscales Eating in Public, Understandability of Speech, and Normalcy of Diet were 55 (range, 0,100), 73 (range, 25,100), and 49 (range, 0,100), respectively. PSS scores were significantly higher in patients with primary closure of the surgical defect, no mandibular surgery, and early T-stage lesions. Conclusions. Although functional outcome may be decreased by certain surgical interventions and advanced T stage, the high rate of locoregional and distant disease control and excellent 2-year disease-specific survival supports an aggressive treatment regimen for advanced tongue base cancer. © 2004 Wiley Periodicals, Inc. Head Neck26: 561,572, 2004 [source]


Older age and liver transplantation: A review

LIVER TRANSPLANTATION, Issue 8 2004
Rajesh N. Keswani
Patients older than 60 are undergoing transplantation with increasing frequency. Reports from several transplant centers document that overall short-term patient survival rates in seniors undergoing liver transplantation are comparable to survival rates of younger adults. However, specific subgroups of older patients may not fare as well. Seniors with far-advanced end-stage liver disease are high-risk for liver transplantation and have poor survival rates. In addition, seniors older than 65 have worse outcomes than those who are 60 to 65, and studies have shown increased mortality with increasing age as a continuous variable. On the other hand, the majority of seniors who survive liver transplantation have full or only minimally limited functional status. Preoperative evaluation of older patients for transplantation requires careful screening to exclude cardiopulmonary disease, malignancy, and other diseases of the aged. Paradoxically, seniors may benefit from a senescent immune system, which results in decreased requirements for immunosuppressive drugs, and possibly a lower rate of acute allograft rejection. Despite good overall short-term survival in the elderly, long-term survival may be worse because of an increased rate of long-term complications, such as malignancy and heart disease. In conclusion, although advanced age is a negative risk factor, advanced age alone should not exclude a patient from liver transplantation; however, it mandates thorough pretransplant evaluation and careful long-term follow-up with attention to usual health maintenance issues in the elderly. (Liver Transpl 2004;10:957,967.) [source]


Thymic carcinoma in children: A report from the Polish pediatric rare tumors study,

PEDIATRIC BLOOD & CANCER, Issue 7 2010
Teresa Stachowicz-Stencel MD
Abstract Background Invasive thymomas and thymic carcinomas are rare tumors jointly accounting between 0.2% and 1.5% of malignancies in adults. They are usually at an advanced stage when diagnosed and have both high recurrence and poor survival rates. In this report, the aim is to explore our experience in the treatment of thymic carcinomas in Polish children. Procedure The clinical data of nine children with thymic carcinomas, treated between 1992 and 2008 in the Polish oncological and surgical centers was retrospectively analyzed. Results In five cases, presenting symptoms resulted from the compression of the respiratory ways by the mediastinal tumor. In two children paraneoplastic autoimmune syndromes were associated with thymic carcinoma. In accordance with the Masaoka classification, two patients had stage II, five had stage III, and two had stage IV of the disease. Diagnostic biopsy of mediastinal tumor was performed on eight patients and one underwent complete primary resection and subsequently received radiotherapy; he has passed 11 years since the conclusion of therapy. Six patients received multi-drug chemotherapy with or without steroids. Delayed surgery was performed in four children (R0-2, R1-1, and R2-1). After complete resection, one child received chemotherapy. In three patients, chemotherapy and radiotherapy was administered. Seven patients died, including six due to progression of the disease with the other as a result of complications following chemotherapy; only two patients classed at stage II remain alive. Conclusions Most thymic tumors in pediatric patients are inoperable at diagnosis, which results in poor prognosis. Improved chemotherapy approaches are needed. Pediatr Blood Cancer 2010;54:916,920 © 2010 Wiley-Liss, Inc. [source]


Preoperative radiation therapy with selective dose escalation to the margin at risk for retroperitoneal sarcoma

CANCER, Issue 2 2006
Ching-Wei D. Tzeng MD
Abstract BACKGROUND Retroperitoneal sarcomas (RPSs) are rare tumors with poor survival rates due to difficult resectability and high local and distant recurrence rates. Preoperative radiation therapy appears to have dosimetric advantages to utilize the tumor as a tissue expander to limit exposure of small bowel to higher radiation doses. METHODS Between June 1999 and December 2003, 16 consecutive patients with biopsy-proven RPS were treated with preoperative radiation with selective dose escalation. This included 45 grays (Gy) in 25 fractions to the entire tumor plus margin and a boost dose of 57.5 Gy to the volume predicted as high risk for positive surgical margins. Treatment toxicity and local control were evaluated prospectively as primary endpoints. The secondary goal was the theoretical calculation of future dose escalation and feasibility. Each patient underwent laparotomy. Tumor response was judged using computed tomography (CT) scan and by necrosis on final pathology. Theoretical treatment plans evaluated the potential for additional radiation dose escalation. RESULTS All patients completed the radiation protocol. The most common acute side effects were nausea/vomiting, which affected 4 patients (25%), with only 1 patient requiring inpatient intravenous hydration. There was no severe late postoperative morbidity or mortality. Twelve tumors (75%) decreased in maximum dimension, with a median decrease of 9.4%. Fourteen of 16 patients (88%) underwent complete macroscopic resection. With a median follow-up of 28 months (range, 7-52 months), there were only 2 local recurrences. The actuarial 2-year local control rate was 80%. Theoretical treatment plans suggest that significant dose escalation (up to 80 Gy) may be possible. CONCLUSIONS Preoperative radiation therapy with selective dose escalation to the margin at risk is tolerable and allows higher radiation dose to the volume judged to be at greatest risk for local tumor recurrence. Cancer 2006. © 2006 American Cancer Society. [source]