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.

Retrospective, observational data collection of the treatment of phenylketonuria in the UK, and associated clinical and health outcomes

OBJECTIVE

To determine the percentage of phenylketonuria (PKU) subjects using current treatment strategies whose phenylalanine (Phe) concentrations diverge from the UK target guidelines for PKU.

RESEARCH DESIGN AND METHODS

This retrospective, observational, chart review was conducted between 2004 and 2008 at three specialist PKU treatment centres in the UK, and included 125 eligible subjects: 20 adults (18+ years, with ≥4 Phe concentrations measured per year) and 105 children (up to age 17, with ≥6 Phe concentrations measured per year).

RESULTS

The mean percentage of subjects with at least 70% of Phe concentrations within the target range for 0-5-year olds, 6-10 year olds and 11-17 year olds was similar across the period 2004-2008 (57.0%, 56.5% and 57.1%, respectively) and lower (39.4%) in the 18+ year age group. For all ages, across the period the mean was 54.4%. Further analysis of the adult population showed that some subjects were very good at complying with treatment and reporting Phe concentrations. Overall, the percentage of 100% compliance was 15.7% in females and 13.7% in males. The mean duration that subjects were 'out of range' of target Phe concentrations over the study period was approximately 1 year and 3 months and the mean duration for 'significantly out of range' values was approximately 9 months. The most common type of contact made with subjects was by telephone, with a mean number of 16 calls per subject per year.

CONCLUSION

The results support current literature showing that a proportion of subjects with PKU, in particular older subjects, are not fully compliant with their treatment and subsequently have Phe concentrations that depart from national recommendations. However, definitive conclusions may not be drawn due to the retrospective nature of the study and the small number of observed subjects.

Age at death of patients with colorectal cancer and the effect of lead-time bias on survival in elective vs emergency surgery

AIM

Colorectal cancer survival depends on stage at presentation, and current strategies aim for improvements through early detection. Previous studies have demonstrated improved survival from diagnosis but not increased life expectancy. While lead-time bias may account for variations in known prognostic indicators and also influence screening programmes, only age at death provides a true representation of the effectiveness of an intervention. We aimed to compare age at death for patients with colorectal cancer presenting on an emergency or elective basis.

METHOD

Patients presenting with colorectal cancer (2000-2006) were entered into a prospective database (analysis 1 December 2008). Fields included age at death, emergency/elective presentation, palliative/curative intent and disease stage.

RESULTS

One thousand six hundred and fifty patients (922 men) were identified. Elective patients presented younger than emergency patients (67.9 vs 70.6 years; P < 0.005). Dukes B patients presented older than Dukes D (P = 0.02). Mortality was 41% at time of analysis; no difference was seen in mean age at death between emergency and elective presentation (72.8 vs 72.0 years; P = 0.379) or palliative and curative intent (72.0 vs 72.5 years; P = 0.604).

CONCLUSION

Colorectal cancer is common in a population where actuarial life expectancy is limited. Current colorectal cancer early detection strategies may improve cancer-specific survival by increasing lead-time bias but do not influence overall life expectancy.

Nurse-lead clinics for capecitabine: A prospective audit evaluating changes in toxicity profile and efficacy

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Background: Oral chemotherapy offers patients equal efficacy but fewer visits to hospital and less time spent traveling, but there are concerns about toxicity and compliance. Nursing and physician interactions with patients are different, and when a nurse-lead oral chemotherapy service was developed in NE Scotland in 2003 a prospective audit was begun to monitor safety and efficacy.

Methods: Patients with colorectal cancer who declined or were not eligible for appropriate clinical trials had their course of adjuvant or palliative capecitabine chemotherapy prospectively monitored through a nurse-lead clinic. At every clinic visit data was collected on patient demographics, blood and imaging results, and adverse events (AEs). Any decision to change dose was made by the colorectal oncology medical staff.

Results: From September 2003 to November 2006 there were 177 patients prospectively monitored through the nurse-lead clinics. Palliative patients (n = 100), median age 69 (range 43-89) and majority PS 0 or 1. Initial dose reduction in 30% due to low GFR and 13% due to being >75 years old. Overall 77% of patients completed on the starting dose. AE's, shown in table, and efficacy compared with capecitabine registration data (younger age group). Median overall survival 47.7 weeks (cf 56.6 weeks). Adjuvant patients (n = 77), median age 64 (range 40-88) and all PS 0 or 1. Initial dose reduction in 19% due to low GFR and 2% due to being >75 years old. Overall 58% completed on the starting dose (= X-ACT study). AEs, other than 5% G3/4 lethargy, and efficacy similar when compared with X-ACT data, including 3 year DFS of 64% (cf X-ACT 64%).

Conclusions: Using nurses to assess patients receiving capecitabine does not seem to significantly alter efficacy but does alter the AE profile compared with the registration data, particularly in the palliative patients. Differences in the nurse-patient relationship with nurses seen as less busy, more approachable and not taking treatment decisions can improve the quality of care in patients receiving capecitabine chemotherapy.

[Table: see text]

[Table: see text]

Putting the brakes on the anti-viral response: negative regulators of type I interferon (IFN) production

Type I IFNs (IFNα/β) are essential anti-viral cytokines produced in response to the detection of viral components by host pattern recognition receptors. IFNα/β production is transient, and aberrant activation can be hazardous to the host. In this article, we review our current understanding of host negative regulatory mechanisms that control IFNα/β production.

Metabolic alterations produced in the liver by chronic ethanol administration. Comparison between the effects produced by ethanol and by thyroid hormones

1. Liver slices from rats treated with thyroxine show an increased rate of O(2) consumption. The extra consumption, but not the basal respiration, can be abolished by ouabain. 2. Dinitrophenol is not effective in increasing the rate of O(2) consumption of liver slices from thyroxine-treated animals but its effectiveness can be recovered in the presence of ouabain. 3. (Na(+)+K(+))-stimulated adenosine triphosphatase activity of liver was increased by administration of thyroxine in vivo. No changes were found in total Mg(2+)-stimulated adenosine triphosphatase activity. 4. Mitochondrial alpha-glycerophosphate dehydrogenase and microsomal NADPH oxidase activity were increased by both thyroxine and chronic ethanol treatment. 5. Liver slices from animals chronically treated with ethanol synthesize urea at an increased rate. 6. Mitochondrial size (section area) is markedly increased in the liver of animals chronically treated with ethanol. 7. Acute administration of ethanol in doses of 4 and 6g/kg significantly increases the uptake of (131)I-labelled thyroxine by the liver. 8. Work reported here, along with results from other investigators, indicates marked similarities between the effects produced in the liver by chronic administration of ethanol and by thyroid hormones.

Quantitative proteomics using stable isotope labeling with amino acids in cell culture reveals changes in the cytoplasmic, nuclear, and nucleolar proteomes in Vero cells infected with the coronavirus infectious bronchitis virus

Virus-host interactions involve complex interplay between viral and host factors, rendering them an ideal target for proteomic analysis. Here we detail a high throughput quantitative proteomics analysis of Vero cells infected with the coronavirus infectious bronchitis virus (IBV), a positive strand RNA virus that replicates in the cytoplasm. Stable isotope labeling with amino acids in cell culture (SILAC) was used in conjunction with LC-MS/MS to identify and quantify 1830 cellular and two viral proteins from IBV-infected cells. Fractionation of cells into cytoplasmic, nuclear, and nucleolar extracts was used to reduce sample complexity and provide information on the trafficking of proteins between the different compartments. Each fraction showed a proportion of proteins exhibiting >or=2-fold changes in abundance. Ingenuity Pathway Analysis revealed that proteins that changed in response to infection could be grouped into different functional categories. These included proteins regulated by NF-kappaB- and AP-1-dependent pathways and proteins involved in the cytoskeleton and molecular motors. A luciferase-based reporter gene assay was used to validate the up-regulation of AP-1- and NF-kappaB-dependent transcription in IBV-infected cells and confirmed using immunofluorescence. Immunofluorescence was used to validate changes in the subcellular localization of vimentin and myosin VI in IBV-infected cells. The proteomics analysis also confirmed the presence of the viral nucleocapsid protein as localizing in the cytoplasm, nucleus, and nucleolus and the viral membrane protein in the cytoplasmic fraction. This research is the first application of SILAC to study total host cell proteome changes in response to positive sense RNA virus infection and illustrates the versatility of this technique as applied to infectious disease research.

Radiation risk from fluoroscopically-assisted anterior cruciate ligament reconstruction

INTRODUCTION

Precise tunnel positioning is crucial for success in anterior cruciate ligament (ACL) reconstruction. The use of intra-operative fluoroscopy has been shown to improve the accuracy of tunnel placement. Although radiation exposure is a concern, we lack information on the radiation risk to patients undergoing fluoroscopically-assisted ACL reconstruction with a standard C-arm. The aim of our study was to determine the mean radiation doses received by our patients.

PATIENTS AND METHODS

Radiation doses were recorded for 18 months between 1 April 2007 and 30 September 2008 for 58 consecutive patients undergoing ACL reconstruction assisted by intra-operative fluoroscopy. Dose area product (DAP) values were used to calculate the entrance skin dose (ESD), an indicator of potential skin damage and the effective dose (ED), an indicator of long-term cancer risk, for each patient.

RESULTS

The median age of 58 patients included in data analysis was 28 years (range, 14-52 years), of whom 44 were male (76%). The mean ESD during intra-operative fluoroscopy was 0.0015 +/- 0.0029 Gy. The mean ED was 0.001 +/- 0.002 mSv. No results exceeded the threshold of 2 Gy for skin damage, and the life-time risk of developing new cancer due to intra-operative fluoroscopy is less than 0.0001%.

CONCLUSIONS

Radiation doses administered during fluoroscopically-assisted ACL reconstruction were safe and do not represent a contra-indication to the procedure.

Closure of Loop Ileostomies: Is Early Discharge Safe and Achievable?

A prospective audit of the complications associated with reversal of a loop ileostomy was carried out between March 2000 and March 2005. The complication rate, length of inpatient hospitalisation and re-admission rate were assessed in 100 patients, in a single clinical practice. The median (interquartile range) length of time between the primary procedure and closure was 133 days (120 – 270) days. Median length of inpatient stay was two days (one - three) days. The overall complication rate was 18 %. One patient had a post-operative leak leading to local abscess formation. This was drained surgically after initial failure with radiological drainage. A second patient had a late leak, three weeks after closure, leading to fistula formation. This patient required surgical resection of the anastomosis after failure of conservative management. Twelve patients were re-admitted with small bowel obstruction (12%), of whom 11 were managed conservatively, while one underwent further surgery. There was one post- operative death as a result of acute cardiac failure secondary to undiagnosed hypertensive cardiomyopathy.

Thus early discharge following closure of a loop ileostomy, can be achieved with an acceptably low serious complication rate.

Self expanding wall stents in malignant colorectal cancer: is complete obstruction a contraindication to stent placement?

OBJECTIVE

Technical failures have previously been associated with complete clinical obstruction and complete block to the retrograde flow of gastrograffin is considered by some to be a contraindication to the procedure. We report on the technical and clinical success rates of self-expanding metallic stents (SEMS) in both complete and incomplete obstruction in a prospective series of malignant colorectal obstructions.

METHOD

A prospective study of all patients undergoing attempted palliative and bridge to surgery SEMS placement for malignant colorectal obstruction over a 7-year period (April 1999-October 2006) was undertaken.

RESULTS

Seventy-two patients (49 males) with a mean age of 71 years (range 49-98) were included. Technical success was achieved in 27 of 32 patients (84%) with complete obstruction and 33 of 36 patients (92%) with incomplete obstruction, P < 0.46, Fishers exact test. Clinical success was achieved in 17 of 26 patients (65%) with complete obstruction and 24 of 33 patients (73%) with incomplete obstruction, P < 0.58, Fishers exact test. Although placed correctly in 89% cases, relief of symptoms occurred in only 71%, P = 0.002, matched pairs test. There were two colonic perforations in the series with one procedure related death.

CONCLUSION

Placement of SEMS for obstructing colorectal cancer is technically successful in a high proportion of cases. Complete radiological obstruction is not a contraindication to stent placement. The relief of obstructive symptoms following successful placement of a wall stent is less predictable.

Expression of the NS3 protease of cytopathogenic bovine viral diarrhea virus results in the induction of apoptosis but does not block activation of the beta interferon promoter

Bovine viral diarrhea virus (BVDV; genus Pestivirus) can exist as two biotypes, cytopathogenic (CP) and non-cytopathogenic (NCP). The CP form differs from NCP by the continual expression of free non-structural protein 3 (NS3). CP BVDV infection of cultured cells induces apoptosis, whereas NCP BVDV infection has been reported to block the induction of beta interferon (IFN-beta). To investigate the viral mechanisms underlying these effects, NS3 or NS2-3 proteins of NCP and CP BVDV biotypes, together with the cognate NS3 co-factor NS4A, were expressed in cells, and their effect on apoptosis and induction of IFN-beta was investigated. Expression of NS3/4A resulted in increased activity of caspase-9 and caspase-3, indicating induction of the intrinsic apoptosis pathway. Mutational analysis revealed that a protease-inactive NS3/4A was unable to induce apoptosis, suggesting that NS3 protease activity is required for initiation of apoptosis during CP BVDV infection. The ability of NS2-3 to modulate activation of the IFN-beta promoter was also investigated. These studies confirmed that, unlike the related hepatitis C virus and GB virus-B, BVDV proteases are unable to inhibit TLR3- and RIG-I-dependent activation of the IFN-beta promoter. These data suggest that BVDV NS3/4A is responsible for regulating the levels of cellular apoptosis and provide new insights regarding the viral elements associated with CP biotype pathogenesis.

ERK5 regulation in naïve T-cell activation and survival

ERK5 has been implicated in regulating the MEF2-dependent genes Klf2 and nur77 downstream of the TCR and the maintenance of expression of CD62L on peripheral T cells. Based on this data, knockout of ERK5 would be predicted to compromise T-cell development and the maintenance of T cells in the periphery. Using an ERK5 conditional knockout, driven by CD4-CRE or Vav-CRE transgenes resulting in the loss of ERK5 in T cells, we have found that ERK5 is not required for T-cell development. In addition, normal numbers of T cells were found in the spleens and lymph nodes of these mice. We also find that TCR stimulation is not a strong signal for ERK5 activation in primary murine T cells. ERK5 was found to contribute to the induction of Klf2 but not nur77 mRNA following TCR activation. Despite the reduction in Klf2 mRNA, no effect was seen in ERK5 knockouts on either the mRNA levels for the Klf2 target genes CD62L, CCR7 and S1P, or the cell surface expression of CD62L. These results suggest that while ERK5 does contribute to Klf2 regulation in T cells, it is not essential for the expression of CD62L or T-cell survival.

Cascade genetic testing for mismatch repair gene mutations

Mismatch repair gene mutation carriers have a high risk of developing colorectal cancer, and can benefit from appropriate surveillance. A combined population based ascertainment cascade genetic testing approach provides a systematic and potentially effective strategy for identifying such carriers. We have developed a Markov Chain computer model system which simulates various factors influencing cascade genetic testing; including demographics, uptake, genetic epidemiology and family size. This was used to evaluate cascade genetic testing for mismatch repair gene mutations in theory and practice. Simulations focussed on the population of Scotland by way of illustration, and were based on a 20-year programme in which index cases were ascertained from colorectal cancer cases aged<55 years at onset. Results indicated that without practical barriers to cascade genetic testing, 545 (95% CI=522, 568) carriers could be identified; 42% of the population total. This comprised approximately 140 index cases, 302 asymptomatic relatives and 104 previously affected relatives. However, when realistic ascertainment and acceptance rates were used to inform simulations, only 257 (95% CI=246, 268) carriers, about 20% of the carrier population, were identifiable. Of these approximately 112 were index cases, 108 were asymptomatic relatives, and 37 were previously affected relatives. This contrast emphasises the importance of ascertainment and acceptance rates. Likewise the low number of index cases shows that case identification is a limiting factor. In the absence of robust data from epidemiological studies, these findings can inform decisions about the use of cascade genetic testing for mismatch repair gene mutations.

MSK regulate TCR-induced CREB phosphorylation but not immediate early gene transcription

Stimulation of the T cell receptor activates the ERK1/2 and p38 mitogen-activated protein kinase (MAPK) cascades. We demonstrate that TCR stimulation also activates the mitogen- and stress-activated kinases (MSK) downstream of ERK1/2 and p38 in both a T cell line and primary peripheral T cells. MSK1/2-knockout mice were found to have normal numbers of T cells in the thymus, and development of these cells appeared unaffected. Using naive T cells and T lymphoblasts from MSK1/2-knockout mice, it was found that MSK was the kinase responsible for phosphorylation of the transcription factor CREB in response to TCR stimulation. Phosphorylation of CREB by MSK has been linked to the transcription of nur77, nor1 and c-fos downstream of MAPK signalling in various cell types. In T cells, the TCR-dependent transcription of these genes was found to require a MAPK-dependent but MSK-independent signalling pathway. Nevertheless, the number of T cells present in the spleens of MSK1/2-knockout mice and the IL-2-induced proliferation of these cells was reduced compared to wild-type mice. This correlated to a reduction in the TCR-induced up-regulation of the IL-2 receptor CD25 and a requirement for MSK in IL-2-induced CREB phosphorylation.

Prospective treatment in carnitine-acylcarnitine translocase deficiency

Carnitine-acylcarnitine translocase (CACT) deficiency is a rare disorder that results in long-chain fatty acids being unavailable for mitochondrial beta-oxidation and ketogenesis. It can present in the neonatal period or infancy with a severe clinical form, typically with convulsions, hypothermia, encephalopathy, cardiomyopathy and liver dysfunction, or with a milder phenotype with episodes of hypoglycaemia and hyperammonaemia during intercurrent illness. Investigations show hypoketonaemia, intermittent dicarboxyluria and hypocarnitinaemia with grossly elevated acylcarnitines. Enzyme assay or DNA analysis confirms the diagnosis. The severe phenotype results in severe disability or death. The less severe phenotype can also cause significant disability secondary to hypoglycaemia and/or hyperammonaemia at presentation. We report the outcome of two siblings with CACT deficiency. The index patient presented at the age of 2 months during a respiratory illness with hypoglycaemia, hyperammonaemia and cardiorespiratory collapse. Acylcarnitine profiles showed decreased free carnitine but striking elevations of long-chain acylcarnitines. Urine organic acids showed dicarboxylic aciduria. Fatty acid oxidation studies showed reduced oleate and myristate oxidation. His acylcarnitine profile normalized after he was started on a medium-chain triglyceride (MCT) low-fat diet and carnitine supplementation. Low CACT activity on enzyme assay confirmed the diagnosis. He has resulting profound developmental delay and epilepsy. The sibling was prospectively treated with a low-fat MCT diet and carnitine supplementation. Acylcarnitine profile at birth also showed elevated long-chain acylcarnitines. Fatty acid oxidation studies confirmed the diagnosis. To date he has normal development and has not had any significant periods of hypoglycaemia or hyperammonaemia.