Extra-axial chordomas

INTRODUCTION

A chordoma is a slow growing malignant tumour of notochordal origin. A tumour with histological features that are identical to those of a chordoma may arise outside the axial skeleton. To date, there is little in the literature documenting their clinical course.

METHODS

Our large orthopaedic oncology database was used to document the clinical course of extra-axial chordoma.

RESULTS

Over a 30-year period, 131 patients diagnosed with a chordoma were treated at our unit. Only three (2.3%) of these cases were extra-axial chordomas: one in the femur, one in the ulna and one in the proximal fibula. All underwent surgical resection.

CONCLUSIONS

In view of the rarity of this tumour and the difficulty in confirming its diagnosis, we suggest that any suspected case is discussed with a specialist sarcoma multidisciplinary team so that the correct diagnosis can be achieved and treatment tailored accordingly.

The challenges of vitamin and mineral supplementation in children with inherited metabolic disorders: a prospective trial

BACKGROUND

In order to achieve metabolic stability, dietary treatment of inborn errors of metabolism may require restriction of protein, fat or carbohydrate. Manipulation of dietary intake potentially reduces micronutrient status, and provision of a comprehensive vitamin and mineral supplement becomes an essential adjunct to dietary treatment.

AIM

To review the efficacy of a new complete vitamin and mineral supplement [Fruitivits, Vitaflo Ltd] in 14 subjects in an open prospective 26-week study.

METHOD

All subjects had dietary restrictions: low protein diets (57%, n = 8), regular daytime cornstarch and overnight glucose polymer tube feeds (29%, n = 4), low fat diet (7%, n = 1) and modified Atkins diet (7%, n = 1). Plasma nutritional biochemistry, anthropometry and food frequency questionnaires were collected at week 0, 12 and 26 weeks respectively.

RESULTS

Five nutritional parameters showed a significant improvement from baseline (week 0) to study end (week 26): folate (P = 0.01), vitamin E (P = 0.04), plasma selenium (P = 0.002), whole blood selenium (P = 0.04) and total vitamin D (P = 0.008). All the other nutritional markers did not significantly change. Even with regular monitoring, 37% of the product remained unused.

CONCLUSIONS

Despite improvements in some nutritional markers, overall use of the vitamin and mineral supplement was less than prescribed. New methods are needed to guarantee delivery of micronutrients in children at risk of deficiencies as a result of an essential manipulation of diet in inborn disorders of metabolism.

MAVEN observations of the response of Mars to an interplanetary coronal mass ejection

Coupling between the lower and upper atmosphere, combined with loss of gas from the upper atmosphere to space, likely contributed to the thin, cold, dry atmosphere of modern Mars. To help understand ongoing ion loss to space, the Mars Atmosphere and Volatile Evolution (MAVEN) spacecraft made comprehensive measurements of the Mars upper atmosphere, ionosphere, and interactions with the Sun and solar wind during an interplanetary coronal mass ejection impact in March 2015. Responses include changes in the bow shock and magnetosheath, formation of widespread diffuse aurora, and enhancement of pick-up ions. Observations and models both show an enhancement in escape rate of ions to space during the event. Ion loss during solar events early in Mars history may have been a major contributor to the long-term evolution of the Mars atmosphere.

Early MAVEN Deep Dip campaign reveals thermosphere and ionosphere variability

The Mars Atmosphere and Volatile Evolution (MAVEN) mission, during the second of its Deep Dip campaigns, made comprehensive measurements of martian thermosphere and ionosphere composition, structure, and variability at altitudes down to ~130 kilometers in the subsolar region. This altitude range contains the diffusively separated upper atmosphere just above the well-mixed atmosphere, the layer of peak extreme ultraviolet heating and primary reservoir for atmospheric escape. In situ measurements of the upper atmosphere reveal previously unmeasured populations of neutral and charged particles, the homopause altitude at approximately 130 kilometers, and an unexpected level of variability both on an orbit-to-orbit basis and within individual orbits. These observations help constrain volatile escape processes controlled by thermosphere and ionosphere structure and variability.

The challenges of managing coexistent disorders with phenylketonuria: 30 cases

INTRODUCTION

The few published case reports of co-existent disease with phenylketonuria (PKU) are mainly genetic and familial conditions from consanguineous marriages. The clinical and demographic features of 30 subjects with PKU and co-existent conditions were described in this multi-centre, retrospective cohort study.

METHODS

Diagnostic age of PKU and co-existent condition, treatment regimen, and impact of co-existent condition on blood phenylalanine (Phe) control and PKU management were reported.

RESULTS

30 patients (11 males and 19 females), with PKU and a co-existent condition, current median age of 14 years (range 0.4 to 40 years) from 13 treatment centres from Europe and Turkey were described. There were 21 co-existent conditions with PKU; 9 were autoimmune; 6 gastrointestinal, 3 chromosomal abnormalities, and 3 inherited conditions. There were only 5 cases of parental consanguinity. Some patients required conflicting diet therapy (n=5), nutritional support (n=7) and 5 children had feeding problems. There was delayed diagnosis of co-existent conditions (n=3); delayed treatment of PKU (n=1) and amenorrhea associated with Grave's disease that masked a PKU pregnancy for 12 weeks. Co-existent conditions adversely affected blood Phe control in 47% (n=14) of patients. Some co-existent conditions increased the complexity of disease management and increased management burden for patients and caregivers.

CONCLUSIONS

Occurrence of co-existent disease is not uncommon in patients with PKU and so investigation for co-existent disorders when the clinical history is not completely consistent with PKU is essential. Integrating care of a second condition with PKU management is challenging.

The Nutritional Intake of Patients with Organic Acidaemias on Enteral Tube Feeding: Can We Do Better?

BACKGROUND

Detailed nutritional intake data on children with organic acidaemias (OA) (propionic acidaemia (PA), vitamin B12 nonresponsive methylmalonic acidaemia (MMA) and isovaleric acidaemia (IVA)) remains unreported. Aim and subjects: A review of the longitudinal nutritional intake of 14 children with organic acidaemias (PA n = 8; MMA n = 5; IVA n = 1) dependent on enteral tube feeding (≥90% of energy requirements) from a single treatment centre.

METHODS

Nutritional intake (energy, protein, precursor-free L-amino acids, vitamins and minerals), anthropometry and nutritional biochemistry data were collated from diagnosis to current age.

RESULTS

The median energy intake was only 72% (63-137) of the estimated average DH (1991) requirement (EAR), decreasing significantly by 40% between 6 months and 5 years (p < 0.05). Total protein intake met WHO/FAO/UNU (2007) safe intake levels with median (range) precursor-free L-amino acids providing 21% (14-28) of total protein intake. Median mineral intake for sodium was 57% (20-97%), potassium 64% (27-125%) and magnesium 72% (22-116%) and was consistently < RNI for all age points. Fibre median intake was 4 g/day (0-11 g), and fluid intake provided 80% (60-100%) of the requirements for age. Linear growth was poor, and children were overweight for their height (1-10 years: z score median weight +0.6, height -1.2). Nutritional markers consistently indicated that plasma valine concentrations were < target reference ranges in PA and MMA. Iron deficiency anaemia was common in MMA/PA, and in PA, 50% of plasma zinc concentrations were < reference range.

CONCLUSION

In MMA/PA, energy intake decreases over time, weight gain accelerates, but linear height is poor. There are many nutrient deficiencies which may affect short- and long-term outcome of patients with organic acidaemias. The quality of long-term diet in these conditions deserves more attention.

How strict is galactose restriction in adults with galactosaemia? International practice

Dietary management of 418 adult patients with galactosaemia (from 39 centres/12 countries) was compared. All centres advised lactose restriction, 6 restricted galactose from galactosides ± fruits and vegetables and 12 offal. 38% (n=15) relaxed diet by: 1) allowing traces of lactose in manufactured foods (n=13) or 2) giving fruits, vegetables and galactosides (n=2). Only 15% (n=6) calculated dietary galactose. 32% of patients were lost to dietetic follow-up. In adult galactosaemia, there is limited diet relaxation.

Practices in prescribing protein substitutes for PKU in Europe: No uniformity of approach

BACKGROUND

There appears little consensus concerning protein requirements in phenylketonuria (PKU).

METHODS

A questionnaire completed by 63 European and Turkish IMD centres from 18 countries collected data on prescribed total protein intake (natural/intact protein and phenylalanine-free protein substitute [PS]) by age, administration frequency and method, monitoring, and type of protein substitute. Data were analysed by European region using descriptive statistics.

RESULTS

The amount of total protein (from PS and natural/intact protein) varied according to the European region. Higher median amounts of total protein were prescribed in infants and children in Northern Europe (n=24 centres) (infants <1 year, >2-3g/kg/day; 1-3 years of age, >2-3 g/kg/day; 4-10 years of age, >1.5-2.5 g/kg/day) and Southern Europe (n=10 centres) (infants <1 year, 2.5 g/kg/day, 1-3 years of age, 2 g/kg/day; 4-10 years of age, 1.5-2 g/kg/day), than by Eastern Europe (n=4 centres) (infants <1 year, 2.5 g/kg/day, 1-3 years of age, >2-2.5 g/kg/day; 4-10 years of age, >1.5-2 g/kg/day) and with Western Europe (n=25 centres) giving the least (infants <1 year, >2-2.5 g/kg/day, 1-3 years of age, 1.5-2 g/kg/day; 4-10 years of age, 1-1.5 g/kg/day). Total protein prescription was similar in patients aged >10 years (1-1.5 g/kg/day) and maternal patients (1-1.5 g/kg/day).

CONCLUSIONS

The amounts of total protein prescribed varied between European countries and appeared to be influenced by geographical region. In PKU, all gave higher than the recommended 2007 WHO/FAO/UNU safe levels of protein intake for the general population.

Dose reduction of scattered photons from concrete walls lined with lead: Implications for improvement in design of megavoltage radiation therapy facility mazes

PURPOSE

This study explores the possibility of using lead to cover part of the radiation therapy facility maze walls in order to absorb low energy photons and reduce the total dose at the maze entrance of radiation therapy rooms.

METHODS

Experiments and Monte Carlo simulations were utilized to establish the possibility of using high-Z materials to cover the concrete walls of the maze in order to reduce the dose of the scatteredphotons at the maze entrance. The dose of the backscatteredphotons from a concrete wall was measured for various scattering angles. The dose was also calculated by the FLUKA and EGSnrc Monte Carlo codes. The FLUKA code was also used to simulate an existing radiotherapy room to study the effect of multiple scattering when adding lead to cover the concrete walls of the maze. Monoenergetic photons were used to represent the main components of the x ray spectrum up to 10 MV.

RESULTS

It was observed that when the concrete wall was covered with just 2 mm of lead, the measured dose rate at all backscattering angles was reduced by 20% for photons of energy comparable to Co-60 emissions and 70% for Cs-137 emissions. The simulations with FLUKA and EGS showed that the reduction in the dose was potentially even higher when lead was added. One explanation for the reduction is the increased absorption of backscatteredphotons due to the photoelectric interaction in lead. The results also showed that adding 2 mm lead to the concrete walls and floor of the maze reduced the dose at the maze entrance by up to 90%.

CONCLUSIONS

This novel proposal of covering part or the entire maze walls with a few millimeters of lead would have a direct implication for the design of radiation therapy facilities and would assist in upgrading the design of some mazes, especially those in facilities with limited space where the maze length cannot be extended to sufficiently reduce the dose.

Delayed diagnosis in metastatic lesions of the foot

INTRODUCTION

Pedal acrometastases are a rare complication of disseminated malignancy. To date, there is little in the literature documenting their clinical course.

METHODS

Our large orthopaedic oncology database was used to review the clinical course of symptomatic pedal acrometastases.

RESULTS

A total of 15 cases of pedal acrometastases were identified from 2,595 patients with metastases. The median age at presentation was 64.5 years (range: 14-83 years) and the median length of foot symptoms (predominantly pain and swelling) prior to diagnosis of metastasis was 16 weeks (range: 6-104 weeks). The median survival following diagnosis was 4.6 months (range: 2.3-104.5 months).

CONCLUSIONS

This study suggests that 0.58% of all osseous metastases involve the foot, and that symptoms of foot pain and swelling are often misdiagnosed, leading to delays in treatment. A high index of suspicion is required to diagnose pedal acrometastases early, thereby allowing early treatment so that the patient's quality of life can be maintained prior to death.

Mapping the dynamic expression of Wnt11 and the lineage contribution of Wnt11-expressing cells during early mouse development

Planar cell polarity (PCP) signaling is an evolutionarily conserved mechanism that coordinates polarized cell behavior to regulate tissue morphogenesis during vertebrate gastrulation, neurulation and organogenesis. In Xenopus and zebrafish, PCP signaling is activated by non-canonical Wnts such as Wnt11, and detailed understanding of Wnt11 expression has provided important clues on when, where and how PCP may be activated to regulate tissue morphogenesis. To explore the role of Wnt11 in mammalian development, we established a Wnt11 expression and lineage map with high spatial and temporal resolution by creating and analyzing a tamoxifen-inducible Wnt11-CreER BAC (bacterial artificial chromosome) transgenic mouse line. Our short- and long-term lineage tracing experiments indicated that Wnt11-CreER could faithfully recapitulate endogenous Wnt11 expression, and revealed for the first time that cells transiently expressing Wnt11 at early gastrulation were fated to become specifically the progenitors of the entire endoderm. During mid-gastrulation, Wnt11-CreER expressing cells also contribute extensively to the endothelium in both embryonic and extraembryonic compartments, and the endocardium in all chambers of the developing heart. In contrast, Wnt11-CreER expression in the myocardium starts from late-gastrulation, and occurs in three transient, sequential waves: first in the precursors of the left ventricular (LV) myocardium from E7.0 to 8.0; subsequently in the right ventricular (RV) myocardium from E8.0 to 9.0; and finally in the superior wall of the outflow tract (OFT) myocardium from E8.5 to 10.5. These results provide formal genetic proof that the majority of the endocardium and myocardium diverge by mid-gastrulation in the mouse, and suggest a tight spatial and temporal control of Wnt11 expression in the myocardial lineage to coordinate with myocardial differentiation in the first and second heart field progenitors to form the LV, RV and OFT. The insights gained from this study will also guide future investigations to decipher the role of non-canonical Wnt/PCP signaling in endoderm development, vasculogenesis and heart formation.