Non-ossifying fibroma of the spine

Special low protein foods for phenylketonuria in Turkey: An examination of their nutritional composition compared to regular food

Background: Special low protein foods (SLPF) that are phenylalanine (Phe)-free or have a low Phe content are an integral part of PKU diet therapy. Aim: The aim of this study is to determine the nutritional profiles of SLPFs used in Turkey and to compare their contents with equivalent products in the "regular" category, in order to evaluate nutritional and metabolic risks. Methods: Between February and March 2022, the information concerning the nutritional contents of "special low protein products" recommended for PKU and available in Turkey were obtained from the websites of producers/suppliers. Results: A total of 148 SLPFs were identified in Turkey. Compared to regular products, SLPFs were determined to contain less sugar and high carbohydrate content in the Turkish market (p < 0.001). Overall, SLPF products had higher dietary fiber compared to products with regular protein content (p < 0.001). In SLPF subgroups, meat substitutes, rice and pasta, and soup products had significantly less total fat than regular products; low protein bread, sweet snacks, and salted crackers were found to contain less saturated fat (p < 0.05). Moreover, all SLPFs contained significantly more salt than regular products, especially the salt content of subgroups of low protein bread, flour, pasta, and rice was significantly higher than regular products (p < 0.05). Conclusion: Including detailed nutritional information on the Turkish SLPFs' food labels will be effective for patients with PKU to follow themselves on their own.

The first total vertebral involvement of benign fibrous histiocytoma: A case report and literature review

BACKGROUND

Benign fibrous histiocytoma (BFH) is a rare bone tumor, extremely seldom in the spine.

METHODS

We present a 52-year-old patient diagnosed with a BFH in the thoracic spine treated with total en bloc spondylectomy. A review of the published literature was also conducted.

RESULTS

Non-ossifying fibroma (NOF) and BFH are named as one tumor called NOF/BFH. A total of 20 spinal BFHs have been previously reported, mainly involving the posterior elements. We present a BFH with total vertebral involvement. Curettage and excision are the main treatment options with limited recurrence.

CONCLUSIONS

This is the first total vertebral BFH up to now. Spinal BFH occupies rather low aggressiveness. With rather limited recurrence and malignant degeneration, surgical interventions seem enough for its management.

Treating Phenylketonuria: A Single Centre Experience

Hyperphenylalaninaemia (HPA) is an inherited disorder that results in raised plasma phenylalanine levels with a range of severities, including phenylketonuria (PKU). Since the first attempts at treatment using a low-phenylalanine diet and after more than 50 years of research, considerable progress has been made so we are now at a stage where mental retardation caused by high plasma phenylalanine can be prevented. We must, however, be aware of the new challenges we face in managing PKU. These include: maintaining optimal growth by providing enough phenylalanine without jeopardizing the child's psychomotor development; providing an optimal nutritional status that ensures other essential nutrients, such as long chain polyunsaturated fatty acids, are not excluded from the diet; ensuring optimal compliance to the dietary intervention; and considering patients' quality of life. New strategies, such as tetrahydrobiopterin (BH4) supplementation, need to be evaluated with regard to safety, efficacy and expected outcomes in specific types of HPA.

Clinical therapeutics for phenylketonuria

Phenylketonuria was amongst the first of the metabolic disorders to be characterised, exhibiting an inborn error in phenylalanine metabolism due to a functional deficit of the enzyme phenylalanine hydroxylase. It affects around 700,000 people around the globe. Mutations in the gene coding for hepatic phenylalanine hydroxylase cause this deficiency resulting in elevated plasma phenylalanine concentrations, leading to cognitive impairment, neuromotor disorders and related behavioural symptoms. Inception of low phenylalanine diet in the 1950s marked a revolution in the management of phenylketonuria and has since been a vital element of all therapeutic regimens. However, compliance to dietary therapy has been found difficult and newer supplement approaches are being examined. The current development of gene therapy and enzyme replacement therapeutics may offer promising alternatives for the management of phenylketonuria. This review outlines the pathological basis of phenylketonuria, various treatment regimes, their associated challenges and the future prospects of each approach. Briefly, novel drug delivery systems which can potentially deliver therapeutic strategies in phenylketonuria have been discussed.

Randomised controlled trial of essential fatty acid supplementation in phenylketonuria

OBJECTIVE

The long-chain polyunsaturated fatty acids (LC-PUFA) status of children with PKU is often compromised. LC-PUFA, which are important fatty acids in the development of the CNS, can be synthesised endogenously from the parent essential fatty acids (EFA) provided dietary intakes are adequate. This study was designed to assess the biochemical effect over a 20-week period of a phe-free protein substitute that has been supplemented with a balanced blend of n-3 and n-6 EFAs on LC-PUFA status of children with PKU.

DESIGN, SETTING AND SUBJECTS

Fifty three community-living children aged 1-10 years diagnosed with PKU in the newborn period were recruited from seven tertiary centres in the UK and France and randomised to a fat-free control formula or the EFA-supplemented test-treatment formula in an open, prospective study. Forty four children completed the study (20 controls, 24 test-treatments). Fatty acid status was assessed at entry and 20-weeks follow-up. Three day dietary diaries were recorded at 20 weeks' follow-up. The safety, efficacy and palatability of the test-treatment formula were also assessed.

RESULTS

The test-treatment group had significantly higher intakes of fat and EFA than the control group. There was a significant between group difference (P=0.04) in increases in median docosahexaenoic acid (DHA) concentrations in erythrocyte phospholipids, which increased by 19% in the test-treatment group and by 0.5% in the control group over the study period. Growth and phe control were satisfactory in all subjects.

CONCLUSIONS

Supplementing the diets of children with PKU with a balanced blend of n-6 and n-3 EFA improves DHA status without compromising AA status.

Fat intakes of children with PKU on low phenylalanine diets

BACKGROUND

As part of a study on the effects of a fat-supplemented phenylalanine (phe)-free protein substitute on the fatty acid status of children with phenylketonuria (PKU), the adequacy of the diets of children aged 1-10 years for fat and essential fatty acids (EFA) was assessed.

METHODS

Subjects randomized in a 1 : 1 ratio to a phe-free protein substitute supplemented with EFA (test-treatment group) or a phe-free, fat-free protein substitute (control group) for 20 weeks. 3-day semi-weighed records of food intakes collected at the end of the study period.

RESULTS

Total fat and alpha-linolenic acid (alpha-LA) intakes were found to be poor in the control group (n = 19). Those in the test-treatment group (n = 24) had higher fat and EFA intakes (P < 0.05), bringing intakes closer to population norms. The youngest children (<5 years of age) in the control group appeared to be especially vulnerable to poor fat intakes because of the restricted diversity of their diets and, regardless of age, alpha-LA intakes by this group were poor compared with the non-PKU population.

CONCLUSIONS

The quantity and quality of fat in the diets of children with PKU, in particular young children, should be given careful consideration in trying to optimize the ratio of linoleic acid: alpha-LA in their diets and in satisfying the requirements of this group for fat and alpha-LA.

Intake and blood levels of fatty acids in treated patients with phenylketonuria

BACKGROUND

Investigators in Italy and Spain have suggested that therapy for patients with phenylketonuria (PKU) may result in essential fatty acid (EFA) deficiency. Objectives of this study were to determine if the diets of patients with PKU in the United States provided adequate EFA intakes and whether patients could form long-chain polyunsaturated fatty acids.

METHODS

Patients (1-13 years of age) with classic PKU undergoing therapy and their non-PKU sibling closest in age were compared. Nutrient intakes were calculated from 3-day diet diaries. Fatty acids in plasma and erythrocytes were identified and quantified. Paired t tests compared results for the patients and their non-PKU siblings.

RESULTS

Twenty-eight patients and 26 siblings were studied. Mean fat intake was greatest by siblings (34.8 +/- 1.3% of energy) and lowest by Phenyl-Free-fed patients (19.5 +/- 1.2% of energy; P < 0.05). Fat intake (30.4 +/- 1.8% of energy) by Phenex-fed patients did not differ from that of siblings. Percentage of energy ingested as C18:2n-6 and C18:3n-3 did not differ significantly between patients and siblings. No clinically significant, consistent differences were found in fatty acid levels (wt%) in plasma or erythrocytes between patients with PKU and siblings.

CONCLUSIONS

No patient in this study exhibited a Holman index of EFA deficiency. Siblings ingested animal protein containing C20:5n-3 and C22:6n-3 fatty acids, and this may account for their greater wt% of these plasma and erythrocyte fatty acids. Because patients with PKU do not ingest fatty acids >C18 but C20:4n-6, C20:5n-3, and C22:6n-3 were found in their plasma and erythrocytes, in vivo synthesis from C18:2n-6 and C18:3n-3 appears to occur. Lack of EFA deficiency in patients in this study may be the result of the use of canola and soy oils containing C18:2n-6 and C18:3n-3 rather than olive oil in the diets.

A different approach to treatment of phenylketonuria: phenylalanine degradation with recombinant phenylalanine ammonia lyase

Phenylketonuria (PKU), with its associated hyperphenylalaninemia (HPA) and mental retardation, is a classic genetic disease and the first to have an identified chemical cause of impaired cognitive development. Treatment from birth with a low phenylalanine diet largely prevents the deviant cognitive phenotype by ameliorating HPA and is recognized as one of the first effective treatments of a genetic disease. However, compliance with dietary treatment is difficult and when it is for life, as now recommended by an internationally used set of guidelines, is probably unrealistic. Herein we describe experiments on a mouse model using another modality for treatment of PKU compatible with better compliance using ancillary phenylalanine ammonia lyase (PAL, EC 4.3.1.5) to degrade phenylalanine, the harmful nutrient in PKU; in this treatment, PAL acts as a substitute for the enzyme phenylalanine monooxygenase (EC 1.14.16.1), which is deficient in PKU. PAL, a robust enzyme without need for a cofactor, converts phenylalanine to trans-cinnamic acid, a harmless metabolite. We describe (i) an efficient recombinant approach to produce PAL enzyme, (ii) testing of PAL in orthologous N-ethyl-N'-nitrosourea (ENU) mutant mouse strains with HPA, and (iii) proofs of principle (PAL reduces HPA)-both pharmacologic (with a clear dose-response effect vs. HPA after PAL injection) and physiologic (protected enteral PAL is significantly effective vs. HPA). These findings open another way to facilitate treatment of this classic genetic disease.