Dietary management of urea cycle disorders: UK practice

BACKGROUND

There is no published data describing UK dietary management of urea cycle disorders (UCD). The present study describes dietary practices in UK inherited metabolic disorder (IMD) centres.

METHODS

Cross-sectional data from 16 IMD centres were collected by a questionnaire describing the management of UCD patients on prescribed protein-restricted diets.

RESULTS

One hundred and seventy-five patients [N-acetylglutamate synthase deficiency, n = 3; carbamoyl phosphate synthase deficiency (CPS), n = 8; ornithine transcarbamoylase deficiency (OTC), n = 75; citrullinaemia, n = 41; argininosuccinic aciduria (ASA), n = 36; arginase deficiency, n = 12] were reported; 70% (n = 123) aged 0-16 years; 30% (n = 52) >16 years. Prescribed median protein intake decreased with age (0-6 months: 2 g kg(-1) day(-1); 7-12 months: 1.6 g kg(-1) day(-1); 1-10 years: 1.3 g kg(-1) day(-1); 11-16 years: 0.9 g kg(-1) day(-1) and >16 years: 0.8 g kg(-1) day(-1)) with little variation between disorders. Adult protein prescription ranged 0.4-1.2 g kg(-1) day(-1) (40-60 g day(-1)). In the previous 2 years, 30% (n = 53) were given essential amino acid supplements (EAAs) (CPS, n = 2; OTC, n = 20; citrullinaemia, n = 15; ASA, n = 7; arginase deficiency, n = 9). EAAs were prescribed for low plasma quantitative essential amino acids (n = 13 centres); inadequate natural protein intake (n = 11) and poor metabolic control (n = 9). From diagnosis, one centre prescribed EAAs for all patients and one centre for severe defects only. Only 3% (n = 6) were given branch chain amino acid supplements. Enteral feeding tubes were used by 25% (n = 44) for feeds and 3% (n = 6) for medications. Oral energy supplements were prescribed in 17% (n = 30) of cases.

CONCLUSIONS

In the UK, protein restriction based on World Health Organization 'safe intakes of protein', is the principle dietary treatment for UCD. EAA supplements are prescribed mainly on clinical need. Multicentre collaborative research is required to define optimal dietary treatments.

Higher order Pancharatnam-Berry phase and the angular momentum of light

The first experimental demonstration of a new Pancharatnam-Berry phase for light beams with spatially inhomogeneous, or vector, states of polarization referred to as the higher-order Pancharatnam-Berry phase is presented. This new geometric phase is proportional to light's total angular momentum, a sum of spin and higher dimensional orbital angular momentum, sharply contrasting the well-known Pancharatnam-Berry phase associated with the plane wave state of polarization of a spatially homogeneous light beam. The higher-order Pancharatnam-Berry phase is directly related to the rotational symmetry of a vortex-bearing electromagnetic field, associated with the rotational frequency shift of a light beam, and has implications in quantum information science as well as other physical systems such as electron vortex beams.

Feeding difficulties in children with inherited metabolic disorders: a pilot study

BACKGROUND

In children with inherited metabolic disorders (IMD), feeding difficulties are often assumed to be inherent, although there is little evidence describing their frequency or severity. The present study aimed to describe feeding patterns/difficulties among children with IMD on protein-restricted diets from one centre.

METHODS

Data from an observational, pilot study of 20 IMD children, nine females (median age, 2.7 years; range, 1-6 years) were compared with data obtained from a retrospective historical group of 15 healthy children (HC), 12 females, aged 1-5 years (median 3.0 years). Caregivers completed a feeding assessment questionnaire, and three separate video recordings were taken of each child eating at home.

RESULTS

The main feeding problems identified by the caregivers' questionnaire in the IMD group (compared to HC) were: poor appetite (55% versus 7%; P = 0.004), limited food variety (55% versus 27%; P = 0.04) and lengthy mealtimes (70% versus 20%; P = 0.006). During mealtimes, children from the IMD group were more likely to vomit, exhibit negative behaviour, get distracted and self-feed less often. From video recordings of meals, although the median meal duration was similar for the two groups (18 min IMD versus 16 min HC), the HC ate twice the quantity of food (3.4 mouthfuls min(-1) versus 1.5 mouthfuls min(-1) ; P < 0.001). During mealtimes, IMD caregivers were less likely to talk to their children (median parent to child communications: IMD group, seven in 10 min; HC, 17 in 10 min). Eighty-three percent of IMD children regularly ate alone.

CONCLUSIONS

In children with IMD on protein restrictions, severe feeding difficulties were common. Caregivers need to focus more attention on the social aspects of feeding. Further larger scale studies are required.

Emotion recognition and oxytocin in patients with schizophrenia

BACKGROUND

Studies have suggested that patients with schizophrenia are impaired at recognizing emotions. Recently, it has been shown that the neuropeptide oxytocin can have beneficial effects on social behaviors.

METHOD

To examine emotion recognition deficits in patients and see whether oxytocin could improve these deficits, we carried out two experiments. In the first experiment we recruited 30 patients with schizophrenia and 29 age- and IQ-matched control subjects, and gave them an emotion recognition task. Following this, we carried out a second experiment in which we recruited 21 patients with schizophrenia for a double-blind, placebo-controlled cross-over study of the effects of oxytocin on the same emotion recognition task.

RESULTS

In the first experiment we found that patients with schizophrenia had a deficit relative to controls in recognizing emotions. In the second experiment we found that administration of oxytocin improved the ability of patients to recognize emotions. The improvement was consistent and occurred for most emotions, and was present whether patients were identifying morphed or non-morphed faces.

CONCLUSIONS

These data add to a growing literature showing beneficial effects of oxytocin on social-behavioral tasks, as well as clinical symptoms.

Minocycline treatment for HIV-associated cognitive impairment: results from a randomized trial

OBJECTIVE

We conducted a study of minocycline to assess its safety, tolerability, and efficacy for the treatment of HIV-associated cognitive impairment.

METHODS

HIV-1-infected individuals with progressive neurocognitive decline were enrolled in a double-blind, placebo-controlled study of minocycline. Participants were randomized to receive minocycline 100 mg or matching placebo orally every 12 hours. The primary efficacy measure was change in a neuropsychological test composite z score (NPZ-8) from baseline to week 24. Measures of safety included the frequency of adverse events and changes over time in laboratory tests. After 50% of participants completed the double-blind phase, an interim analysis of futility for the primary outcome measure was performed, and our Data and Safety Monitoring Board recommended early study termination.

RESULTS

A total of 107 HIV-1-infected individuals with cognitive impairment were enrolled. The minocycline group did not show improvement in the primary outcome measure (NPZ-8) (mean 24-week change = 0.12) compared to placebo (mean 24-week change = 0.17) (95% confidence interval = [-0.26, 0.39], p = 0.70). There were few severe adverse events or laboratory abnormalities in either treatment group.

CONCLUSION

Minocycline was safe and well-tolerated in individuals with HIV-associated cognitive impairment, but cognitive improvement was not observed. Classification of evidence. This interventional study provides Class II evidence for the safety, tolerability, and efficacy of minocycline for the treatment of HIV-associated cognitive impairment.

Empirical aspects of linking intensive care registry data to hospital discharge data without the use of direct patient identifiers

In the field of intensive care, clinical data registries are commonly used to support clinical audit and develop evidence-based practice. However, they are often restricted to the intensive care unit episode only, limiting their ability to follow long-term patient outcomes and identify patient readmissions. Data linkage can be used to supplement existing data, but a lack of unique patient identifiers may compromise the accuracy of the linkage process. The aim of this study was to assess the quality of linking the Australia/New Zealand critical care registry to a state financial claims database using a method without direct patient identifiers and to identify possible sources of bias from this method. We used a linkage method relying on indirect patient identifiers and compared the accuracy of this method to one that also included the patient medical record number and date of birth. The overall linkage rate using the method with indirect identifiers was 92.3% compared to 94.5% using the method with direct identifiers. Factors most strongly associated with not being a correct link in the first method included patients at one study hospital, admissions in 2002 and 2003 and having a hospital length of stay of 20 days or more. Linking the Australia/New Zealand critical care without direct patient identifiers is a valid linkage method that will enable the measurement of long-term patient survival and readmissions. While some sources of bias have been identified, this method provides sufficient quality linkage that will support broad analyses designed to signal future in-depth research.

Retrospective Audit of Blood Transfusion and Comparison with Haemoglobin Concentration in Patients Undergoing Elective Primary and Revision Lower Limb Arthroplasty

We retrospectively audited the incidence of blood transfusion and related this to preoperative haemoglobin levels in 181 patients undergoing lower limb arthroplasty over a six-month period. This included 102 primary total knee replacements, 52 primary total hip replacements, 11 revision total knee replacements and 16 revision total hip replacements.

The overall incidence of transfusion was 16.0%. The incidence in primary arthroplasty was 11% (9.8% for total knee replacements and 13.5% for total hip replacements), and in revision surgery was 44.4% (27.3% for total knee replacements and 56.3% for total hip replacements).

Combining data for primary total knee replacements and primary total hip replacements, a preoperative haemoglobin threshold of 120 g/l divided patients into high and low risk groups for transfusion. Below or equal to this threshold the incidence of transfusion was 47.7%; above this threshold the incidence was 7.2%.

We suggest that patients having primary lower limb arthroplasty with a preoperative haemoglobin of 120 g/l or less should undergo investigation of their anaemia and optimisation of erythropoeisis.

Evaluation of a primary care-based temazepam withdrawal programme

Focal points

Accuracy of home enteral feed preparation for children with inherited metabolic disorders

BACKGROUND

Many children with rare chronic disorders require home enteral tube feeds (HETF) consisting of multiple modular ingredients. Feeds are often complex and the risk of errors during their preparation is high. The consequences of over- or under-concentration can be critical. The aim of the present prospective observation study was to assess the accuracy, skills and technique of caregivers when preparing and administering HETF.

METHODS

Fifty-two HETF patients (median age 7.5 years, range 0.7-18.0 years) with inherited metabolic disorders (IMD) requiring special feeds were recruited. Using observation and a structured questionnaire, a practical assessment of feed preparation and storage by the main caregiver was undertaken by an independent dietitian and nurse in the child's home, including hygiene practices, accuracy of measuring recipe ingredients, and storage of both ingredients and prepared feeds.

RESULTS

The majority (85%; n = 44) of feeds were based on >1 ingredient (median 3; range 1-6). Almost half (48%; n = 25) of caregivers measured feed ingredients inaccurately. Of the 31% (n = 16) using scoops, 31% used incorrect measuring spoons and 25% did not level scoops appropriately. Some 45% (n = 20/44) of carers measured liquid ingredients inaccurately. Hygiene practices during feed preparation were poor, including a lack of hand washing (31%: n = 16) and incorrect storage procedures for unused feed ingredients (56%; n = 29).

CONCLUSIONS

Practices in the preparation of modular HETF for children with IMD were not ideal. A combination of inaccuracy, poor hygiene, inappropriate storage, and long feed hanging times increases both metabolic and microbial risk. Better education, regular monitoring and the development of ready-to-use or preweighed ingredients would be beneficial.

Gamma bang time analysis at OMEGA

Absolute bang time measurements with the gas Cherenkov detector (GCD) and gamma reaction history (GRH) diagnostic have been performed to high precision at the OMEGA laser facility at the University of Rochester with bang time values for the two diagnostics agreeing to within 5 ps on average. X-ray timing measurements of laser-target coupling were used to calibrate a facility-generated laser timing fiducial with rms spreads in the measured coupling times of 9 ps for both GCD and GRH. Increased fusion yields at the National Ignition Facility (NIF) will allow for improved measurement precision with the GRH easily exceeding NIF system design requirements.

Monitoring of home safety issues in children on enteral feeds with inherited metabolic disorders

OBJECTIVE

To assess the safety aspects of carers' enteral feeding technique when home enteral tube feeding children with inherited metabolic disorders (IMD).

METHODS

40 patients (median age, 5.1 years; range, 0.3-13.6 years) with IMD requiring pump tube feeding were recruited. 12 patients had glycogen storage disease, 11 organic acidemias, 8 fatty acid oxidation disorders, 4 urea cycle disorders, and 5 had other conditions. 50% of the patients were fed by gastrostomy and 50% nasogastric tube. A questionnaire and practical assessment of feeding process was completed with carers by a dietician and nurse in the child's home. Areas investigated included carer hygiene, feed preparation, tube care, tube changing, use of feeding pumps and equipment, and storage of enteral feeding equipment.

RESULTS

The main issues identified were poor hygiene practices (78% unclean work surfaces; 25% no hand washing); inaccurate ingredient measuring (40%); irregular checking of tube position (40%); inadequate tube flushing (50%); poor knowledge of how to clear tube blockages (80%); incorrect priming of pump sets (50%); incorrect position of child for night feeding (63%); untrained secondary carers (43%); and poor knowledge of pump alarms, battery life, and charging time. Children commonly slept in parent's room as a safety precaution (58%).

CONCLUSIONS

Long term follow-up of children with IMD on home enteral tube feeding suggests that regular updates on knowledge and technique for carers may be necessary to reduce risk.

Molecular pathways in the progression of hormone-independent and metastatic prostate cancer

Once prostate cancer becomes castration resistant, cancer cells may rapidly gain the ability to invade and to metastasize to lymph nodes and distant organs. The progression through hormone-dependent to hormone-independent/castration-resistant and metastatic PCa is poorly understood. In this review paper, we provide an overview on the cellular and molecular mechanisms underlying the process of tumor cell invasion and metastasis in prostate cancer. We specifically present the most recent findings on the role of multiple cellular signaling pathways including androgen receptor (AR), mitogen-activated protein kinases (MAPK), Akt, transforming growth factor b (TGFb interleukin-6 (IL-6) and vascular endothelial growth factor (VEGF) in the development of hormone-independent/castration-resistant prostate cancer. In addition, we also discuss the recent findings on signatures of gene expression during prostate cancer progression. Our overviews on the novel findings will help to gain better understanding of the complexity of molecular mechanisms that may play an essential role in the development of castration-resistant and metastatic prostate cancer. It will also shed light on the identification of specific targets and the design of effective therapeutic drug candidates.