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.

[Evaluation of physical development in children with classical phenylketonuria].

Classical phenylketonuria (PKU) is hereditary disease, which is based on the disturbance of phenylalanine conversion to tyrosine. The basic treatment of PKU is low phenylalanine diet. Prolonged restriction of natural protein may have a negative impact to PKU patient growth and physical development. The objective was to evaluate the physical development of patients with classical PKU at birth and on the diet based on the products with different chemical composition without phenylalanine. 257 PKU patients have been examined with the computer program "WHO Anthroplus 2009". All patient were born at term. Z-score of body weight, height and body mass index (BMI) to age has been retrospectively estimated. Patients were divided into 2 groups: group 1--101 children born in 1980-1993 were fed by unadapted specialty products based on protein hydrolyzate with restricted phenylalanine, and group 2--156 children born in 1995-2012 were fed by contemporary amino acid mixtures without phenylalanine. All newborn PKU patients had the middle for age Z-score of weight and BMI, 21% of neonates had high Z-score growth. Before the diet therapy BMI Z-score was normal in 84.1% patients in group 1 and 87.2% patients of group 2. After 6 mo of treatment with low phenylalanine diet the number of patient with normal BMI Z-score was 71.3% in group 1 against 95.6% in group 2. Thus, using of modern amino acid mixtures without phenylalanine, enriched with essential nutrients can promote the normal physical development of PKU patients.

[Open, non-comparative phase III clinical study to evaluate the efficacy and safety of sapropterin in patients with phenylketonuria and hyperphenylalaninemia].

BACKGROUND: Phenylketonuria (PKU) is an autosomal recessive inherited disease associated with impaired metabolism of the amino acids phenylalanine (Phe) and tyrosine. The main criterion for diagnosis of PKU is high blood Phe level determined during neonatal screening. In case where PKU patient is responsive to tetrahydrobiopterin treatment, sapropterin restores the impaired activity of the enzyme phenylalanine hydroxylase, resulting in the stimulation of normal Phe metabolism and thereby enhancing patient tolerance to natural products. AIM: The present open, non-comparative clinical study was initiated to assess the degree and frequency of response after 8-day sapropterin administration and assess the safety of 6-week sapropterin treatment in patients with PKU and hyperphenylalaninemia. PATIENTS AND METHODS: The study enrolled 90 patients with PKU. The criterion of response to 8-day sapropterin therapy was the reduction of Phe blood levels ≥ 30% compared with the baseline value. RESULTS: Positive response to treatment was observed in 30 (33.3%) patients (95% CI 23.7-44.1). The mean percentage change in Phe blood levels after the 8-day response test period compared to Phe levels prior to dosing was 14.1 ± 28.4% in the overall subject population (95% CI 8.2-20.1) and 44.3 ± 15.1% in the subpopulation of patients with a positive response (95% CI 38.6-49.9). During the study, adverse events were reported in 24 (26.7%) patients in the overall population in 16 (53.3%) patients in the subpopulation who had a response. CONCLUSION: The study results confirmed the efficacy and safety of sapropterin therapy in patients with PKU, which is consistent with international clinical trials data.

[Assessment of the life quality in children with phenylketonuria].

BACKGROUND: Phenylketonuria (PKU) - the most common inherited disorder of amino acid metabolism, identified in Russia by neonatal screening. The results of dietary treatment demonstrate a positive effect. However, the quality of PKU patients life remains unknown. OBJECTIVE: The aim of the study was to assess the quality of PKU children life in comparison with their healthy peers, also depending on the treatment onset and the patient's age. METHODS: The study involved 64 pairs - PKU child and one of his parents. It was used the common questionnaire survey Pediatric Quality of Life Inventory (PedsQLtm4. 0, Varni et al., USA, 2001) and the program SPSS v. 14.0 (US) for statistical processing of the results. RESULTS: The statistically significant (p <0.001) differences between PKU patients and healthy children in the physical, emotional, social and role functioning were found. The most pronounced differences were observed in the social (70 points vs 90 respectively) and role (57.5 vs 80 respectively) functioning. Maximum significant correlation (p <0.001) was installed between the social functioning of PKU patients and timing of the dietary treatment. Also the statistically significant interaction (p <0.05) was found between the role functioning, patient's age and treatment onset. The assessment points of social and role functioning were higher (p <0.05) in the PKU patients subgroup with early treatment initiation. CONCLUSION: These results confirmed the need of early diagnostics of PKU and initiation of dietary treatment, as well as the organization of timely psychological support for parents of sick children.

[Interaction of the Laburnum anagyroides lectin with fucoantigens].

We studied interaction of the lectin from the bark of Golden Rain shrub (Laburnum anagyroides, LABA) with a number of basic fucose-containing carbohydrate antigens by changes in its tryptophan fluorescence. The strongest LABA binding was observed for the trisaccharide H of type 6 [alpha-L-Fucp-(1-2)-beta-D-Galp-(1-4)-D-Glc, Ka= 4.2 x 10(3) M(-1)]. The following antigens were bound with a weaker affinity: H-disaccharide alpha-L-Fucp-(1-2)-D-Gal, a glucoanalogue of tetrasaccharide Ley alpha-L-Fucp-(1-2)-beta-D-Galp-(1-4)-[alpha-L-Fucp-(1-3)]-D-Glc, and 6-fucosyl-N-acetylglucosamine, a fragment of core of the N-glycans family (Ka 1.1-1.7 x 10(3) M(-1)). The lowest binding was observed for L-fucose (Ka = 2.7 x 10(2) M-1) and trisaccharide Lea, (3-Galp-(1-3)-[a-L-Fucp-(1-4)]-GlcNAc (Ka = 6.4 x 10(2) M(-1)). The Lea, Lea, and Lex pentasaccharides and Leb hexasaccharide were not bound to LABA.

[Features of a cytokine profile in patients with chronic glomerulonephritis with progressive chronic renal failure].

AIM: To specify the cytokine profile in chronic glomerulonephritis (CGN) with aggravating renal function, to assess prognostic value of some cytokines in development of CGN in these patients. MATERIAL AND METHODS: Indices of the cytokine profile were followed up in 56 CGN patients with nephrotic syndrome and arterial hypertension and compared in those patients who developed CGN for 2 years (group 2) versus patients with intact renal function (group 1). RESULTS: Serum levels of IL-1beta and TNF-alpha were maximal in CGN patients with aggravating renal function. Such patients had a low concentration of serum IL-1beta receptors antagonists. Severity of proteinurea correlated with serum level of TNF-alpha. If the latter was higher than 120 pg/ml, there was a high probability of CRF development within 2 years. CONCLUSION: Pathogenesis of CRF in CGN is associated with proinflammatory cytokines, especially TNF-alpha. Its serum concentration can be used for evaluating risk of renal function deterioration.

[Interaction of perch fucolectin with Lewis antigens]. / Vzaimodeistvie fukolektina okunia s l'iuisovymi antigenami.

Interaction of fucolectin of perch Perca fluviatilis (PFL) with a set of Lewis antigens was studied by monitoring changes in its tryptophan fluorescence. PFL bound Le(c) (H type 1)-pentasaccharide (Ka = 6.6 x 10(3) M(-1)) and H type 6-trisaccharide (Ka = 2.5 x 10(3) M(-1)); essentially weaker, with Le(b)-hexasaccharide (Ka = = 4.0 x 10(2) M(-1)); and failed to interact with Le(a)-, Le(x)-, and Le(d)-containing oligosaccharides. PFL belongs to a new type of the fucolectins recognizing H-disaccharide Fuc alpha1-2Gal within various antigens, including H type 1/2 and Le(b).

The structure of the yrdC gene product from Escherichia coli reveals a new fold and suggests a role in RNA binding.

The yrdC family of genes codes for proteins that occur both independently and as a domain in proteins that have been implicated in regulation. An example for the latter case is the sua5 gene from yeast. SuaS was identified as a suppressor of a translation initiation defect in cytochrome c and is required for normal growth in yeast (Na JG, Pinto I, Hampsey M, 1992, Genetics 11:791-801). However, the function of the Sua5 protein remains unknown; Sua5 could act either at the transcriptional or the posttranscriptional levels to compensate for an aberrant translation start codon in the cyc gene. To potentially learn more about the function of YrdC and proteins featuring this domain, the crystal structure of the YrdC protein from Escherichia coli was determined at a resolution of 2.0 A. YrdC adopts a new fold with no obvious similarity to those of other proteins with known three-dimensional (3D) structure. The protein features a large concave surface on one side that exhibits a positive electrostatic potential. The dimensions of this depression, its curvature, and the fact that conserved basic amino acids are located at its floor suggest that YrdC may be a nucleic acid binding protein. An investigation of YrdC's binding affinities for single- and double-stranded RNA and DNA fragments as well as tRNAs demonstrates that YrdC binds preferentially to double-stranded RNA. Our work provides evidence that 3D structures of functionally uncharacterized gene products with unique sequences can yield novel folds and functional insights.

[Comparative study of special products "Tetraphen" and "Phenyl-free" in diet therapy of children with phenylketonuria]. / Sravnitel'naia otsenka ispol'zovaniia spetsializirovannykh produktov "Tetrafen" i "Fenil-fri" v dietoterapii detei, bol'nykh fenilketonuriei.

Basing on the comparative clinical and biochemical evaluation of the usage of the specialized product "Tetraphen" (Russia) and early utilized product "Phenyl-Free" (USA) it has been shown that "Tetraphen" does not yield to "Phenyl-Free", while some of its parameters (energy value, carbohydrate content) even in the higher degree correspond to the physiologic requirements of this aged children suffering from phenylketonuria. Intake of this product in smaller doses completely covers their requirements for the basic food ingredients. High frequency of carotenoids insufficiency in children received both "Tetraphen" and "Phenyl-Free" demonstrate necessity of the diet correction by means of beta-carotene additional supplementation.

[Effectiveness of beta-carotene for treatment of erosive ulcerative changes in gastric and duodenal mucosa in children with chronic glomerulonephritis]. / Otsenka éffektivnosti primeneniia beta-karotina pri érozivno-iazvennykh izmeneniiakh slizistoi obolochki zheludka i dvenadtsatiperstnoi kishki u detei s khronicheskim glomerulonefritom.

The peptic ulcer of stomach and duodenum are the more often occuring complications of steroid treatment in children with chronic glomerulonephrite. Dinamic investigation has shown that the using of beta-carotin oily solution in therapy of this complications increases the efficiency of traditional treatment. It has been shown that beta-carotene administration speeds the reparation of stomach and duodenum ulcers, saves adequate serum concentration of beta-carotene and retinol. The data obtained demonstrate that beta-carotene administration in the complex therapy of chronic glomerulonephrite patient with gastroenteropathy should be recommended.

Interaction of smooth muscle caldesmon with calmodulin mutants.

The interaction of avian smooth muscle caldesmon with calmodulin (CaM) was investigated by studying the ability of selected mutant calmodulins to induce fluorescence changes in caldesmon. Different types of CaM mutants were used including point charge mutants, cluster mutations, and mutations which alter the calcium binding of CaM. The caldesmon binding properties were only slightly affected by E84K-CaM or by the double mutation E84Q/E120Q-CaM. Affinity of calmodulin to caldesmon was decreased 2-4 times by point mutation G33V-CaM, double mutation E84K/E120K-CaM, deletion of residues 82-84, and by cluster mutations DEE118-120-->KKK or EEE82-84-->KKK. Mutations of the first (E31A-CaM) and the second (E67A-CaM) calcium binding sites reduced the affinity of calmodulin to caldesmon by at least 5-fold; in addition these calmodulin mutants exhibited smaller changes in the fluorescence spectra of caldesmon. Simultaneous mutation of the two negatively charged clusters of calmodulin EEE82-84-->KKK and DEE118-120-->KKK resulted in a more than 15-fold decrease in the affinity of calmodulin for caldesmon. The data indicate that charged and uncharged amino acids in both halves of CaM play an important role in the binding of calmodulin to caldesmon, and that Ca2+ binding must be maintained in the amino-terminal sites for maximal interaction with caldesmon.

[Structure-functional properties of conjugates of proteins with polyalkylene oxides: study by a fluorescence method]. / Strukturno-funktsional'nye svoistva kon''iugatov belkov s polialkilenoksidami: issledovanie metodom fluorestsentsii.

A fluorescent study of some structural and functional properties of conjugates of a number of proteins (bovine serum albumin, pyruvate kinase, alpha-chymotrypsin, and the two toxic proteins of plant origin--ricin and viscumin) with polyalkylene oxides (polyethylene glycol and pluronic) has been carried out. Analysis of the intrinsic protein fluorescence showed that the structure and stability of various protein conjugates to denaturing agents change only slightly: the conformational mobility of tryptophan residues accessible to the solvent decreases, whereas that of tryptophan residues localized in the protein regions of low polarity remains unchanged. Besides, the conjugates display a higher thermal stability in comparison with their native proteins. The fluorescence of 1-anilinonaphthalene-8-sulfonic acid and water insoluble 2',3',4',5'-tetrabenzoylriboflavin bound to the native and modified proteins indicated that modification of the proteins with polyalkylene oxides decreased the polarity and increased the viscosity of the microenvironment. Hence, this modification makes it possible to change some functional characteristics of the protein without causing any significant changes in its structure.

[Calcium homeostasis and calcium-regulating hormones in young children with phenylketonuria]. / Sostoianie kaltsievogo gomeostaza i kaltsiireguliruiushchikh gormonov u detei rannego vozrasta, bolnykh fenilketonuriei.

Calcium and calcium-regulating hormones were investigated in 19 infants with phenylketonuria. Parathyroid hormone, osteocalcin, dehydrocholecalciferol were found elevated while calcitonin reduced in the serum of the infants prior to the diet. Total calcium and phosphorus remained stable in the course of the study. Element diet resulted in reduced serum parathormone levels though surpassing those of healthy subjects. This fact is attributed to primary metabolic disorders responsible for the onset of hyperparathyroidism. The conclusion is made that element diet is unable to change calcium homeostasis and that of calcium-regulating hormones in infants with phenylketonuria.