Evolution of aminoacyl-tRNA synthetase quaternary structure and activity: Saccharomyces cerevisiae mitochondrial phenylalanyl-tRNA synthetase

Phenylalanyl-tRNA synthetases [L-phenylalanine:tRNAPhe ligase (AMP-forming), EC 6.1.1.20] from Escherichia coli, yeast cytoplasm, and mammalian cytoplasm have an unusual conserved alpha 2 beta 2 quaternary structure that is shared by only one other aminoacyl-tRNA synthetase. Both subunits are required for activity. We show here that a single mitochondrial polypeptide from Saccharomyces cerevisiae is an active phenylalanyl-tRNA synthetase. This protein (the MSF1 gene product) is active as a monomer. It has all three characteristic sequence motifs of the class II aminoacyl-tRNA synthetases, and its activity may result from the recruitment of additional sequences into an alpha-subunit-like structure.     

Renal transplants from category III non-heart-beating donors with evidence of pre-arrest acute renal failure

Kidneys transplanted from non-heart-beating donors (NHBDs) have been exposed to varying degrees of ischemic damage after death. Category III donors have invariably been managed, treated, and investigated in a hospital setting prior to arrest and death. Some therefore exhibit evidence of renal dysfunction and even acute renal failure (ARF) before death. Many surgeons would regard a NHBD with pre-arrest evidence of ARF as too marginal for renal transplantation. This retrospective study examines five Maastricht category III NHBD donors with evidence of pre-arrest ARF. We compare 3- and 12-month GFR outcome data from the nine resulting transplants with 40 category III NHBD transplants with normal pre-arrest renal function. The mean GFR at 3 months was 45.4 and 43.8 for the ARF and normal group, respectively. At 12 months the GFR was 42.2 and 44.7 in the ARF and normal groups, respectively. Thus evidence of ARF pre-arrest does not preclude successful category III NHBD renal transplantation.     

Dual renal transplantation for kidneys from marginal non-heart-beating donors

Kidneys transplanted from non-heart-beating donors (NHBD) are generally regarded as marginal or extended criteria grafts due to the associated period of warm ischemia. The most prolonged periods occurring in the category II (uncontrolled) donor. This potential for injury can adversely affect the glomular filtration rate (GFR), which in severe cases results in primary nonfunction. Viability testing can identify a group of kidneys that, although unsuitable for solitary transplantation, may be considered for dual transplant. This retrospective study examined a series of 11 dual renal transplants, comparing 3- and 12-month GFR outcome data with 81 single NHBD transplants. The mean GFR at 3 months in the dual group was 47.6 and at 12 months was 48.6. In the single group the GFR at 3 months was 40.6 and at 12 months was 41.9. Thus using viability testing to identify NHBD kidneys suitable for dual transplant appears reliable and predictable.     

Temozolomide and concomitant whole brain radiotherapy in patients with brain metastases: a phase II randomized trial

PURPOSE: To evaluate the safety profile and efficacy of whole brain radiotherapy (WBRT) concomitantly with temozolomide (TMZ) in patients with brain metastases (BM). METHODS AND MATERIALS: Patients with BM were randomly assigned to 30 Gy of WBRT with or without concomitant TMZ (75 mg/m(2)/d) plus two cycles of TMZ (200 mg/m(2)/d for 5 days). The primary outcome was analysis of neurologic toxicity. The primary efficacy measures were 90-day progression-free survival of BM and the radiologic response at Days 30 and 90. RESULTS: We enrolled 82 patients. No neurologic acute toxicity was observed. Grade 3 or worse hematologic toxicity was seen in 3 patients and Grade 3 or worse vomiting in 1 patient of the WBRT plus TMZ arm. The objective response rate at 30 and 90 days and overall survival were similar in both arms. The percentage of patients with progression-free survival of BM at 90 days was 54% for WBRT vs. 72% for WBRT and TMZ (p = 0.03). Death from BM was greater in the WBRT arm (69% vs. 41%, p = 0.03). CONCLUSION: The concomitant use of RT with TMZ was well tolerated and resulted in significantly better progression-free survival of BM at 90 days. Although caution should be used, these results suggest TMZ could improve local control of BM.     

Home and community based care program assessment for people living with HIV/AIDS in Arba Minch, Southern Ethiopia

Background

Homeless populations have complex and diverse end-of-life care needs. However, they typically die outside of the end-of-life care system. To date, few studies have explored barriers to the end-of-life care system for homeless populations. This qualitative study involving health and social services professionals from across Canada sought to identify barriers to the end-of-life care system for homeless populations and generate recommendations to improve their access to end-of-life care.

Methods

Semi-structured qualitative interviews were conducted with 54 health and social services professionals involved in end-of-life care services delivery to homeless persons in six Canadian cities (Halifax, Hamilton, Ottawa, Thunder Bay, Toronto and Winnipeg). Participants included health administrators, physicians, nurses, social workers, harm reduction specialists, and outreach workers. Interviews were audio-recorded, transcribed verbatim and analysed thematically.

Results

Participants identified key barriers to end-of-life care services for homeless persons, including: (1) insufficient availability of end-of-life care services; (2) exclusionary operating procedures; and, (3) poor continuity of care. Participants identified recommendations that they felt had the potential to minimize these barriers, including: (1) adopting low-threshold strategies (e.g. flexible behavioural policies and harm reduction strategies); (2) linking with population-specific health and social care providers (e.g. emergency shelters); and, (3) strengthening population-specific training.

Conclusions

Homeless persons may be underserved by the end-of-life care system as a result of barriers that they face to accessing end-of-life care services. Changes in the rules and regulations that reflect the health needs and circumstances of homeless persons and measures to improve continuity of care have the potential to increase equity in the end-of-life care system for this underserved population.     

循证护理在直肠癌患者PICC置管中的应用

目的探讨循证护理在直肠癌患者PICC置管中的应用。方法选择2011年1月-2012年1月间在我科行PICC置管的直肠癌患者80例,分为观察组（n=40）和对照组（n=40）,分别采用循证护理方法和常规护理方法护理．观察两组患者首次穿刺成功率及PICC置管后第1、2、3个月并发症的发生情况。结果两组患者首次穿刺成功率为96．25％。术后1个月内,两组患者各种并发症发生率均无统计学意义;术后2个月内,两组患者静脉炎及感染发生率均有统计学意义：术后3个月内。两组患者感染及导管堵塞发生率均有统计学意义。结论循证护理方案比常规护理方案在降低PICC置管并发症的发生率方面更为有效。