Clinically relevant mitochondrial-targeted therapy improves chronic outcomes after traumatic brain injury

Pioglitazone, an FDA-approved compound, has been shown to target the novel mitochondrial protein mitoNEET and produce short-term neuroprotection and functional benefits following traumatic brain injury. To expand on these findings, we now investigate the dose- and time-dependent effects of pioglitazone administration on mitochondrial function after experimental traumatic brain injury. We then hypothesize that optimal pioglitazone dosing will lead to ongoing neuroprotection and cognitive benefits that are dependent on pioglitazone-mitoNEET signalling pathways. We show that delayed intervention is significantly more effective than early intervention at improving acute mitochondrial bioenergetics in the brain after traumatic brain injury. In corroboration, we demonstrate that mitoNEET is more heavily expressed, especially near the cortical contusion, in the 18 h following traumatic brain injury. To explore whether these findings relate to ongoing pathological and behavioural outcomes, mice received controlled cortical impact followed by initiation of pioglitazone treatment at either 3 or 18 h post-injury. Mice with treatment initiation at 18 h post-injury exhibited significantly improved behaviour and tissue sparing compared to mice with pioglitazone initiated at 3 h post-injury. Further using mitoNEET knockout mice, we show that this therapeutic effect is dependent on mitoNEET. Finally, we demonstrate that delayed pioglitazone treatment improves serial motor and cognitive performance in conjunction with attenuated brain atrophy after traumatic brain injury. This study illustrates that mitoNEET is the critical target for delayed pioglitazone intervention after traumatic brain injury, mitochondrial-targeting is highly time-dependent after injury and there is an extended therapeutic window to effectively treat mitochondrial dysfunction after brain injury.

Dealing with loss: food and eating in women with ovarian cancer on parenteral nutrition

BACKGROUND

Malignant bowel obstruction is a common complication of ovarian cancer, resulting in limited oral intake. Home parenteral nutrition (HPN) may be offered to patients in this condition to meet nutritional requirements. However, it is not known how they experience being unable to eat. The present study reports how patients related to food when receiving HPN.

METHODS

The investigation was a qualitative study underpinned by phenomenology with women with advanced ovarian cancer in bowel obstruction receiving parenteral nutrition. Interview transcripts were analysed thematically guided by the techniques of Van Manen.

RESULTS

We recruited 20 women to the study. Participants were interviewed a maximum of four times and a total of 39 in-depth longitudinal interviews were conducted. Participants could tolerate minimal amounts of food, if they had a venting gastrostomy. Not being able to eat engendered a sense of sadness and loss, and most women found it challenging to be in the presence of others eating. They adopted strategies to cope, which included fantasising about food and watching cookery programmes. These approaches were not a long-term solution; either participants came to terms with their loss or the strategies became less effective in providing relief.

CONCLUSIONS

Home parenteral nutrition meets the nutritional requirements of patients with malignant bowel obstruction but cannot replace the non-nutritive functions of food. Healthcare professionals can offer a patient-centred approach by acknowledging the difficulties that patients may face and, wherever possible, encourage them to focus on the positive benefits of interacting with people rather than the loss of eating on social occasions.

Healthy eating interventions in adults living with and beyond colorectal cancer: a systematic review

BACKGROUND

Rates of cancer survival are increasing, with more people living with and beyond cancer. Lifestyle recommendations for cancer survivors are based largely on extrapolation from cancer prevention recommendations. The present study aimed to systematically review the literature on randomised controlled trials (RCTs) focusing on healthy eating interventions in people with colorectal cancer (CRC).

METHODS

A structured search of electronic databases was conducted in March 2018 using medical subject headings (MeSH) and text words related to CRC and diet. The results of the literature searches were uploaded to online software for data management. Titles and abstracts were screened based on the inclusion and exclusion criteria and data were extracted. Quality of data was assessed using the Cochrane Handbook.

RESULTS

Seven studies were identified, including six RCTs and one RCT protocol, with a total of 2233 participants from six studies, of whom 1010 (45%) had CRC. Three studies assessed anthropometrics demonstrating participants who received dietary intervention had a greater reduction in measurements. Six studies assessed changes in dietary components; however, only one demonstrated an increase in dietary fibre. Two studies reported improvements in quality of life favouring dietary intervention groups.

CONCLUSIONS

The quality of identified studies was variable, with limited evidence to support dietary intervention improving dietary intake in people living with or after CRC. Studies to date have not been based on robust study design that has combined all dietary interventions linked to CRC. As a result of the heterogeneity of the studies identified, it was difficult to draw strong conclusions.

A systematic review of the use of ketogenic diets in adult patients with cancer

BACKGROUND

A growing body of evidence indicates the importance of nutrition in cancer treatment. Ketogenic diets are one strategy that has been proposed to enhance traditional anticancer therapy. This review summarises the evidence concerning the effect of oral ketogenic diets on anthropometry, metabolism, quality of life (QoL) and tumour effects, at the same time as documenting adverse events and adherence in patients with cancer.

METHODS

We searched electronic databases using medical subject headings (MeSH) and text words related to ketogenic diets and cancer. Adult patients following a ketogenic diet as a complementary therapy prior, alongside or after standard anticancer treatment for more than 7 days were included. Studies were assessed for quality using the Critical Appraisal Skills Programme tools (https://www.casp-uk.net).

RESULTS

Eleven studies were included with 102 participants (age range 34-87 years) from early-phase trials, cohort studies and case reports. Studies included participants with brain, rectal or mixed cancer sites at an early or advanced disease stage. The duration of intervention ranged from 2.4 to 134.7 weeks (0.5-31 months). Evidence was inconclusive for nutritional status and adverse events. Mixed results were observed for blood parameters, tumour effects and QoL. Adherence to diet was low (50 out of 102; 49%) and ranged from 23.5% to 100%.

CONCLUSIONS

High-quality evidence on the effect of ketogenic diets on anthropometry, metabolism, QoL and tumour effects is currently lacking in oncology patients. Heterogeneity between studies and low adherence to diet affects the current evidence. There is an obvious gap in the evidence, highlighting the need for controlled trials to fully evaluate the intervention.

Patient experiences of perioperative nutrition within an Enhanced Recovery After Surgery programme for colorectal surgery: a qualitative study

AIM

Nutrition is an important element of the Enhanced Recovery After Surgery (ERAS) programme. Patients have previously indicated that nutrition is a key component of ERAS that requires improvement. Our aim was to explore the perioperative nutrition experiences of colorectal surgical patients to identify barriers and facilitators to the integration of nutrition within ERAS.

METHOD

Sixteen individuals undergoing colorectal surgery participated in a semi-structured interview between postoperative day three and hospital discharge. The topic guide was developed iteratively throughout the study; topics included preoperative counselling, carbohydrate loading, fasting and postoperative nutrition. A constant comparison technique was employed during coding, and an inductive thematic analysis was used. Validity was ensured by double coding a sample of transcripts.

RESULTS

Findings are presented in the context of the following clinical themes: preoperative information, preoperative fasting, carbohydrate loading and nutritional drinks, postoperative diet and discharge. Individuals received too much general information which was repetitive, contradictory and not disease specific; this formed a key barrier affecting nutrition. Other barriers were negative experiences of nutritional drinks, stoma management, nausea and vomiting, and challenges from the hospital environment. Facilitators included interactions with staff, food accessibility and choice, and motivation for discharge.

CONCLUSION

The key barrier to adherence of perioperative nutrition protocols was poor provision of information. Targeted information regarding postoperative diet, stoma management and coping with nausea and vomiting would be beneficial for colorectal surgical patients. Easily accessible food provided by ward staff was considered a facilitator.

Improving promoter prediction for the NNPP2.2 algorithm: a case study using Escherichia coli DNA sequences

MOTIVATION

Although a great deal of research has been undertaken in the area of promoter prediction, prediction techniques are still not fully developed. Many algorithms tend to exhibit poor specificity, generating many false positives, or poor sensitivity. The neural network prediction program NNPP2.2 is one such example.

RESULTS

To improve the NNPP2.2 prediction technique, the distance between the transcription start site (TSS) associated with the promoter and the translation start site (TLS) of the subsequent gene coding region has been studied for Escherichia coli K12 bacteria. An empirical probability distribution that is consistent for all E.coli promoters has been established. This information is combined with the results from NNPP2.2 to create a new technique called TLS-NNPP, which improves the specificity of promoter prediction. The technique is shown to be effective using E.coli DNA sequences, however, it is applicable to any organism for which a set of promoters has been experimentally defined.

AVAILABILITY

The data used in this project and the prediction results for the tested sequences can be obtained from http://www.uow.edu.au/~yanxia/E_Coli_paper/SBurden_Results.xls

CONTACT

alh98@uow.edu.au.

Dietary treatment of irritable bowel syndrome: current evidence and guidelines for future practice

The aim of this literature review is to produce guidelines for dietetic practice in irritable bowel syndrome (IBS) by evaluating the research available. In this area randomized control trials (RCT) only account for a small proportion of the literature and have been concentrated in the modification of dietary fibre in patients with IBS. The bulk of the literature is mainly observational trials from which no indisputable conclusions can be extracted. In this review, the evidence available has been interpreted within the context of the current knowledge base. Conclusions are drawn to facilitate the development of guidelines, enabling a starting point for discussion and an evaluation of current practice. The literature available on therapeutic dietary manipulation in IBS patients is centred around non-starch polysaccharides (NSPs), mono and disaccharide sensitivity and food intolerance. The production of these guidelines has focused on research examining the role of dietary components in the therapeutic management of patients with IBS. However, where there is a deficiency in the literature directly relating dietary intake to management of IBS patients, physiological function in relation to dietary components has been relied upon to produce practical guidelines which can be applied realistically in a clinical environment. An interpretation of the evidence has revealed a limited role for exclusion diets, a move away from high-fibre diets towards the manipulation of fibre fractions in the diet, an evaluation of the effects of caffeine on gut function and the necessity for individual dietary assessment to identify dietary issues pertinent to the patient's symptoms. These guidelines outline a positive role for dietitians in the treatment of IBS patients which draws on the unique skills possessed by dietitians regarding the assessment of habitual eating habits and therapeutic dietary manipulation.

Delivery of macromolecules into adherent cells via electroporation for use in fluorescence spectroscopic imaging and metabolic studies

A method is described to introduce by electroporation membrane-impermeant molecules into adherent living cells with little perturbation. The approach uses simple, commonly available equipment to introduce small fluorescent dyes, large carrier-based dyes (e.g., fluorescein-labeled dextran), large macromolecules (e.g., antibodies), and metabolic precursors (e.g., 32P-ATP) with high efficiency. Conditions are relatively independent of cell type. Electroporation with three pulses of 300 volts at 540 microF capacitance at 4 degrees C is a good starting point for many cell types. Electrode distance from the adherent cells was critical at 1.0 +/- 0.15 mm. Suitable poration medium includes calcium-magnesium free phosphate buffered saline (PBS), PBS-buffered 0.25-3.0 M sucrose, Hepes-buffered sucrose, or unbuffered sucrose. Potential use in fluorescence imaging and metabolic studies is shown with DNA synthesis, cell replication, cell substratum attachment, 32P-ATP phosphorylation, and insulin-mediated increases in glucose uptake and its suppression by antiphosphotyrosine and antiglucose transporter protein antibodies. The ability to load foreign molecules into large numbers of adherent cells provides a means of studying these cells individually via microscopic approaches, such as fluorescence spectroscopic imaging, as well as with conventional biochemical and physiological techniques.

Sleep apnea in end-stage renal disease patients on hemodialysis and continuous ambulatory peritoneal dialysis

Fifteen unselected end-stage renal disease patients (nine hemodialysis [HD] and six continuous ambulatory peritoneal dialysis [CAPD]) were randomly selected from four Sydney metropolitan dialysis centers for sleep assessment by full polysomnography. Four of six CAPD patients and eight of nine HD patients were found to have clinically significant obstructive sleep apnea. An additional 21 unselected patients (10 CAPD and 11 HD patients) were assessed using overnight home monitoring of nasal airflow and arterial oxygen saturation. Of these, 8 of the 11 HD and 7 of the 10 CAPD patients were found to have obstructive sleep apnea. These data confirm the high incidence of obstructive sleep apnea in the end-stage renal disease population at large. Screening for obstructive sleep apnea should become a routine part of the management of these patients.

Identification of an intracellular postsynaptic antigen at the frog neuromuscular junction

A layer of amorphous, electron-dense material is situated at the cytoplasmic surface of the postsynaptic membrane of vertebrate neuromuscular synapses. The function of this structure is not clear, but its location suggests that it may have an important role in the formation and/or maintenance of the synapse. This paper demonstrates that a monoclonal antibody raised against antigens from Torpedo electric organ binds to an intracellular, postsynaptic protein at the frog neuromuscular synapse. Indirect immunofluorescence on frozen sections of frog muscle was used to demonstrate that the antigen is concentrated at synaptic sites in normal muscle. In denervated muscle, the antigen remains concentrated at synaptic sites, but is also present at extrasynaptic regions of denervated myofibers. The antigen cannot be labeled in intact, whole muscle, but only in whole muscle that has been permeabilized with nonionic detergents. The antibody staining pattern in Triton X-100-permeabilized whole-mounts of the frog neuromuscular synapse is arranged in elongate, arborized areas which are characteristic of the frog neuromuscular synapse. The stained areas are striated and the striations occur with a periodicity that corresponds to the regular folding of the postsynaptic membrane. Immunoferritin labeling of fixed, saponin-permeabilized muscle demonstrates that the antigen is associated with amorphous material that is situated between the postsynaptic membrane and an underlying layer of intermediate filaments. The antigen, solubilized from membrane and an underlying layer of intermediate filaments. The antigen, solubilized from Torpedo electric organ by high ionic strength, was identified by antibody binding to nitrocellulose replicas of SDS gels of Torpedo tissue. In Torpedo tissue, the antibody binds to a single protein band at 51,000 daltons (51 kd). The 51-kd protein shares an antigenic determinant with intermediate filament proteins, since a monoclonal antibody to all intermediate filaments reacts with the same 51-kd protein. The monoclonal antibody also reacts with a 55-kd protein in frog skin which is localized to the perinuclear region of the epithelial cells.