Effects of aging and caloric restriction on mitochondrial energy production in gastrocnemius muscle and heart

Mitochondria are chronically exposed to reactive oxygen intermediates. As a result, various tissues, including skeletal muscle and heart, are characterized by an age-associated increase in reactive oxidant-induced mitochondrial DNA (mtDNA) damage. It has been postulated that these alterations may result in a decline in the content and rate of production of ATP, which may affect tissue function, contribute to the aging process, and lead to several disease states. We show that with age, ATP content and production decreased by approximately 50% in isolated rat mitochondria from the gastrocnemius muscle; however, no decline was observed in heart mitochondria. The decline observed in skeletal muscle may be a factor in the process of sarcopenia, which increases in incidence with advancing age. Lifelong caloric restriction, which prolongs maximum life span in animals, did not attenuate the age-related decline in ATP content or rate of production in skeletal muscle and had no effect on the heart. 8-Oxo-7,8-dihydro-2'-deoxyguanosine in skeletal muscle mtDNA was unaffected by aging but decreased 30% with caloric restriction, suggesting that the mechanisms that decrease oxidative stress in these tissues with caloric restriction are independent from ATP availability. The generation of reactive oxygen species, as indicated by H2O2 production in isolated mitochondria, did not change significantly with age in skeletal muscle or in the heart. Caloric restriction tended to reduce the levels of H2O2 production in the muscle but not in the heart. These data are the first to show that an age-associated decline in ATP content and rate of ATP production is tissue specific, in that it occurs in skeletal muscle but not heart, and that mitochondrial ATP production was unaltered by caloric restriction in both tissues.

End-of-life issues in intensive care units: a national random survey of nurses' knowledge and beliefs

OBJECTIVE: To investigate the knowledge, beliefs, and ethical concerns of nurses caring for patients dying in intensive care units. METHODS: A survey was mailed to 3000 members of the American Association of Critical-Care Nurses. The survey contained various scenarios depicting end-of-life actions for patients: pain management, withholding or withdrawing life support, assisted suicide, and voluntary and nonvoluntary euthanasia. RESULTS: Most of the respondents (N = 906) correctly identified the distinctions among the end-of-life actions depicted in the scenarios. Almost all (99%-100%) agreed with the actions of pain management and withholding or withdrawing life support. A total of 83% disagreed with assisted suicide, 95% disagreed with voluntary euthanasia, and 89% to 98% disagreed with nonvoluntary euthanasia. Most (78%) thought that dying patients frequently (31%) or sometimes (47%) received inadequate pain medicine, and almost all agreed with the double-effect principle. Communication between nurses and physicians was generally effective, but unit-level conferences that focused on grief counseling and debriefing staff rarely (38%) or never (49%) occurred. Among the respondents, 37% had been asked to assist in hastening a patient's death. Although 59% reported that they seldom acted against their consciences in caring for dying patients, 34% indicated that they sometimes had acted against their conscience, and 6% had done so to a great extent. CONCLUSIONS: Intensive care unit nurses strongly support good pain management for dying patients and withholding or withdrawing life-sustaining therapies to allow unavoidable death. The vast majority oppose assisted suicide and euthanasia. Wider professional and public dialogue on end-of-life care in intensive care units is warranted.

Early behavioral and catecholaminergic effects of 6-hydroxydopamine and guanethidine in the neonatal rat

New born rats received 7 consecutive daily injections of 6-hydroxydopamine (6-OHDA) or guanethidine. Locomotor activity, measured at 3 day intervals, was differentially affected by these drugs, although neither drug elimination a characteristic pattern of ontogeny of locomotor activity. Differing neurochemical effects were also observed. 6-OHDA decreased tyrosine hydroxylase activity in cortex and cerebellum, increased it in the brainstem and had no effect on the hypothalamus. Guanethidine slightly elevated enzyme levels in all four brain regions, with the elevation in brainstem significant at 16 days of age. Regional brain changes in enzyme activity after 4 daily 6-OHDA injections beginning at 1, 5 or 9 days of age indicated that toxic effect of 6-OHDA upon catecholaminergic neurons was age dependent. These data are not consistent with a simple interpretation either in terms of maturational changes in blood brain barrier permeability to 6-OHDA or neuronal uptake of the drug. Further analyses of brainstem areas indicated that the increased brainstem enzyme activity after 6-OHDA was restricted to the pons.

Comparison of 18-lead ECG and selected body surface potential mapping leads in determining maximally deviated ST lead and efficacy in detecting acute myocardial ischemia during coronary occlusion

Kornreich identified 6 body surface potential mapping (BSPM) leads outside the standard 12-lead electrocardiographic (ECG) sites for optimal recognition of ST segment elevation (+) and depression (-) during acute ischemia in anterior, inferior, and posterior myocardial zones (A+, A-, I+, I-, P+, P-). No comparison has been made between the 6 selected BSPM leads and 18-lead ECG (12 + V3-5R + V7-9) in detecting acute myocardial ischemia during coronary occlusion. Continuous 18-lead ECG and 6 selected BSPM leads were recorded in 68 patients (77 vessels) undergoing coronary angioplasty during balloon occlusion. Ischemia was defined as ST segment deviation (deltaST) > or = 100 microV > or = 1 lead from the preinflation baseline. The 18-lead ECG was a more frequent source of the maximal deltaST lead during left anterior descending artery, right coronary artery, and left circumflex artery occlusion (71 [92%]) than the 6 selected BSPM leads (5 [7%]). The 18-lead ECG was more efficacious than the 6 selected BSPM leads for detecting acute myocardial ischemia in the group as whole. The 18-lead ECG was also more efficacious for detecting right ventricular ischemia associated with proximal right coronary artery occlusion and for detecting ST segment elevation during left circumflex artery occlusion. Our findings indicate that the 18-lead ECG is the most frequent source of maximally deviated lead and is more efficacious in detecting myocardial ischemia during balloon occlusion than the 6 selected BSPM leads. The 6 selected BSPM leads do not add information above and beyond the 12- or 18-lead ECG, and thus cannot be recommended as optimal sites for continuous ST segment monitoring of patients with acute coronary syndromes.

Ageing and subcellular distribution of mitochondria: role of mitochondrial DNA deletions and energy production

The rapid growing population of elderly illustrates the importance of understanding the mechanisms responsible for ageing and the detrimental effects on health associated with increasing age. One of the primary mechanisms may be because of the accumulation of mtDNA damage and oxidative damage with age. Previous studies have examined this correlation in post-mitotic tissues such as skeletal muscle, heart and brain with decreased mitochondrial function, such as enzymatic activities of the electron transport chain and ATP production. However, regional differences in the subcellular location of mitochondria exist and most studies have failed to differentiate the effects of these two autonomous fractions, the subsarcolemmal and intermyofibrillar populations. Hence, while future research attempts to explain the mechanisms responsible for ageing in the mitochondrion, it should also take into account the independent pathways of these two distinctly different populations.

The effect of excess dietary iodine on pregnant mares and foals

On a thoroughbred stud four foals were born with greatly enlarged thyroids and leg weakness. Two foals died within 18 hours of birth, the others subsequently recovered. An enlarged thyroid was also evident in one of the resident mares. The thyroids from the dead foals were hyperplastic. Feed analyses showed that the mares had an iodine intake of about 83 mg daily, 8-8 ppm of the dietary dry matter, due almost entirely to the high iodine content of a proprietary compound horse nut which had been fed at the daily rate of 12 lb per head. It was concluded from the histology of the thyroids, the high intake of iodine, the lack of response to treatment with potassium iodide and the elevated levels of serum protein bound iodine that the condition of the foals on the stud was caused by an excess of iodine fed to the mares during pregnancy.

Field trial of a planned breeding regimen for dairy cows, using gonadotrophin-releasing hormone and prostagladin F2alpha

A planned breeding regimen, using gondadotrophin-releasing hormone (GnRH), prostaglandin F2alpha, and a second dose of GnRH, followed by a fixed time insemination, was evaluated in comparison with a negative control on eight commercial dairy farms in the south of England. Fertility data were collected from the 220 cows in the planned breeding group and from 220 matched control cows inseminated at observed oestrus. The planned regimen induced visible oestrus in the vast majority of the cows, and serving the cows at this oestrus reduced the calving to conception interval by 15 days, resulting in 12 per cent more cows being pregnant by 125 days after calving, and 6 per cent more by 150 days. The results from the individual farms suggested that more benefit may be derived from using the regimen in herds with only average fertility indices. There was also evidence to suggest that the second GnRH injection was important, even in cows that came on heat and were served before the fixed time insemination.

Upper airway complications in children after bone marrow transplantation

OBJECTIVE

To describe the upper and lower airway complications in children during bone marrow transplantation (BMT).

STUDY DESIGN

Review of medical records of patients requiring airway intervention during BMT over a 4-year period.

RESULTS

During the 4-year period, 832 pediatric BMTs were performed. Of these, 87 patients (10.5%) required mechanical ventilation. Patients had intubation for a mean of 79 days (range, -7-638 d) after BMT. Patients received mechanical ventilation for a mean of 12 days (range, 1-85 d). Duration of ventilation was significantly longer in patients with difficult intubation; in these 54 patients there were 64 intubations. Of these intubations, 19 (30%) were difficult. These difficult intubations occurred in 16 (30%) patients. Patients with Hurler syndrome and congenital immunodeficiencies had significantly more difficult intubations than children with leukemia. The incidence of complications causing difficult intubation were difficulty visualizing cords, because of the presence of blood (63%); difficulty visualizing cords, because of edema (19%); anatomically narrowed airway (13%); limited neck extension (13%); and limited jaw opening (6%). The resulting mortality rate was 82% in children requiring intubation. Survivors were significantly younger than nonsurvivors.

CONCLUSIONS

Pediatric BMT has become increasingly more common. Airway management is rarely required during the engraftment phase, but when intervention is required, it is often difficult, particularly in the nonleukemic child, and may require the skills of an otolaryngologist. Representative cases are presented, and management is discussed.

Assisted suicide: implications for nurses and nursing

Assisted suicide is an issue of great importance to nurses. This issue reflects our values and beliefs as a society, calls for a clear and precise response as a profession, and challenges individual nurses to think about their own moral views. The history of the debate and the compelling moral arguments on both sides attest to the complexity of the issue and also suggest that it will not soon be resolved. The current position of the profession, as expressed in the ANA Code for Nurses and a specific position statement, were reviewed. The dilemma faced by the individual nurse who perceives an obligation to adhere to the guidelines specified by his or her profession's code and yet whose conscience dictates an act in violation of this code has been discussed as an instance of conscientious objection. While this analysis has been necessarily brief, it was intended to illustrate the importance of being clear about one's personal moral views and equally clear about one's duty to fulfil the obligations stemming from the profession's public statements. It is essential that the profession continue to explore the moral issues involved in requests for assistance in dying and provide additional guidelines for practicing nurses, with sound rationale for the profession's position.

A systematic review assessing non-pharmacological conservative treatment studies for people with non-inflammatory multi-joint pain: clinical outcomes and research design considerations

To systematically review the evidence to determine the clinical outcomes and the important methodological quality features of interventional studies on adults with non-inflammatory multi-joint pain (MJP). Systematic search of published and unpublished literature using the databases: AMED, CINAHL, MEDLINE, EMBASE, psycINFO, SPORTDiscus, PEDro, OpenGrey, the EU Clinical Trials Register, World Health Organization International Clinical Trial Registry Platform, ClinicalTrials.gov and the ISRCTN registry (search: inception to 19th October 2017). All papers reporting the clinical outcomes of non-pharmacological interventions for people with non-inflammatory MJP were included. Studies were critically appraised using the Downs and Black Critical Appraisal and the TIDieR reporting checklists. Data were analysed using a Best Evidence Synthesis approach. From 3824 citations, four papers satisfied the eligibility criteria. Three studies reported outcomes from multidisciplinary rehabilitation programmes and one study reported the findings of a spa therapy intervention. All interventions significantly improved pain, function and quality of life in the short-term. There was limited reporting of measures for absenteeism, presenteeism and psychosocial outcomes. The evidence was 'weak', and due to a lack of controlled trials, there is limited evidence to ascertain treatment effectiveness. Design consideration for future trials surround improved reporting of participant characteristics, interventions and the standardisation of core outcome measures. There is insufficient high-quality trial data to determine the effectiveness of treatments for non-inflammatory MJP. Given the significant health burden which this condition presents on both individuals and wider society, developing and testing interventions and accurately reporting these, should be a research priority. Registration PROSPERO (CRD42013005888).

Novel approach to documenting expert ECG interpretation using eye tracking technology: a historical and biographical representation of the late Dr Rory Childers in action

The 12-lead electrocardiogram (ECG) is a complex set of cardiac signals that require a high degree of skill and clinical knowledge to interpret. Therefore, it is imperative to record and understand how expert readers interpret the 12-lead ECG. This short paper showcases how eye tracking technology and audio data can be fused together and visualised to gain insight into the interpretation techniques employed by an eminent ECG champion, namely Dr Rory Childers.