Molecular genetics and impact of residual in vitro phenylalanine hydroxylase activity on tetrahydrobiopterin responsiveness in Turkish PKU population

BackgroundThe prevalence of phenylalanine hydroxylase (PAH)-deficient phenylketonuria (PKU) in Turkey is high (1 in 6500 births), but data concerning the genotype distribution and impact of the genotype on tetrahydrobiopterin (BH₄) therapy are scarce.ObjectiveTo characterize the phenotypic and genotypic variability in the Turkish PKU population and to correlate it with physiological response to BH₄ challenge.MethodsWe genotyped 588 hyperphenylalaninemic patients and performed a BH₄ loading test (20 mg/kg bw) in 462 patients. Residual PAH activity of mutant proteins was calculated from available in vitro expression data. Data were tabulated in the BIOPKU database (www.biopku.org).ResultsEighty-eight mutations were observed, the most common missense mutations being the splice variant c.1066-11G>A (24.6%). Twenty novel mutations were detected (11 missense, 4 splice-site, and 5 deletion/insertions). Two mutations were observed in 540/588 patients (91.8%) but in 9 patients atypical genotypes with > 2 mutations were found (8 with p.R155H in cis with another variant) and in 19 patients mutations were found in BH₄-metabolizing genes. The most common genotype was c.1066-11G>A/c.1066-11G>A (15.5%). Approximately 22% of patients responded to BH₄ challenge. A substantial in vitro residual activity (average > 25% of the wild-type enzyme) was associated with response to BH₄. In homozygous genotypes (n = 206), both severity of the phenotype (r = 0.83) and residual PAH activity (r = 0.85) correlate with BH₄ responsiveness.ConclusionTogether with the BH₄ challenge, these data enable the genotype-based classification of BH₄ responsiveness and document importance of residual PAH activity. This first report of a large-scale genotype assessment in a population of Turkish PKU patients also documents a high prevalence (47%) of the severe classic phenotype.     

The effect of blood phenylalanine concentration on Kuvan™ response in phenylketonuria

Phenylketonuria (PKU) is caused by mutations in the phenylalanine hydroxylase gene (PAH) with consequent elevation of blood phenylalanine (Phe), reduction in tyrosine (Tyr) and elevation of Phe/Tyr ratio (P/T). Although newborn screening for PKU with early dietary treatment improved severe, irreversible brain damage, older patients suffer reversible losses in executive function when Phe concentrations are elevated. The maintenance of strict nutritional control in older children and adults remains difficult. An adjunct to dietary therapy, oral tetrahydrobiopterin (BH₄) has recently been approved by the Food and Drug Administration as a stable, synthetic BH₄ called Kuvan?. Published studies of Kuvan response in PKU varies and involved primarily children. In this prospective study we evaluated dose–response, response frequency and factors predicting response in 21 patients with PKU (aged 8–30 years), who required life-long dietary treatment. Response to Kuvan was defined at 24 h (acute) and over 4 weeks (chronic) as a ≥ 30% decline in the Phe or P/T ratio. A dose of 20 mg/kg Kuvan was chosen with 29% responding in 24 h and 33% of patients at 4 weeks. We then compared baseline Phe, Tyr, P/T, Phe intake, and frequency of “severe” versus “moderate” mutant PAH alleles among acute and chronic responders and non-responders to Kuvan. Predictors of response to Kuvan, both acute and chronic were baseline Phe and baseline P/T. Baseline Phe and P/T were higher among non-responders (P < 0.05). By contrast baseline Tyr was similar (P = 0.45). Phe intake tended to be higher (18 ± 20 mg/kg/24 h) among Kuvan responders than non-responders (15 ± 11 mg/kg/24 h), P < 0.07 NS. Similarly the frequency of “severe” mutant PAH alleles tended to be more frequent (67%) among non-responders than responders (40%) by Chi² test, P = 0.08 NS. These results were reproducible in a “responder” to Kuvan. To assess directly the effect of elevated blood Phe, Phe was lowered in four, “non-responder” patients, but all failed to respond to Kuvan. We conclude that baseline blood Phe and P/T ratio can predict increased probability for response to Kuvan by patients with classic PKU, but the in vivo mechanisms of response to Kuvan remain enigmatic.     

Relationships between lumbar bone mineral density and biochemical parameters in phenylketonuria patients

BackgroundThe etiology of reduced bone mineral density (BMD) in phenylketonuria (PKU) is unknown. Reduced BMD may be inherent to PKU and/or secondary to its dietary treatment.Materials and methodsLumbar BMD was measured by dual-energy X-ray absorptiometry in 53 early and continuously treated PKU patients (median age 16, range 2–35 years). First, Z-scores of BMD were correlated to age group, clinical severity of PKU, mean phenylalanine (Phe) concentration and Phe variation in the year prior to DXA scanning, as well as to blood vitamin, mineral, and alkaline phosphatase concentrations. Second, parameters were compared between subjects with reduced BMD (Z-score < ? 2 SD) and subjects with normal BMD.ResultsBMD was significantly reduced in our cohort (p = 0.000). Z-scores of BMD were neither significantly correlated to age group, nor clinical severity of PKU. Both mean Phe concentration and Phe variation in the year prior to DXA scanning did not significantly correlate with Z-scores of BMD. Higher blood calcium concentrations were significantly associated with lower BMD (r² = ? 0.485, p = 0.004). Other biochemical parameters, including vitamin B12 availability markers, did not show significant correlations with Z-score of BMD. Subjects with reduced BMD had significantly higher blood phosphorus concentrations than subjects with normal BMD (p = 0.009). No other significant differences were found between both BMD groups.ConclusionReduced BMD in PKU is present from early age onward and does not progress with age. Therefore, BMD deserves attention from early age onward in PKU patients. Our findings are consistent with increased bone turnover in PKU. It remains unclear whether reduced BMD is inherent to PKU and/or secondary to its dietary treatment.     

The activity of wild type and mutant phenylalanine hydroxylase with respect to the C-oxidation of phenylalanine and the S-oxidation of S-carboxymethyl-l-cysteine

The involvement of the enzyme, phenylalanine hydroxylase (PAH), in the S-oxidation of S-carboxymethyl-l-cysteine (SCMC) is now firmly established in man and rat. However, the underlying role of the molecular genetics of PAH in dictating and influencing the S-oxidation polymorphism of SCMC metabolism is as yet unknown. In this work we report that the S-oxidation of SCMC was dramatically reduced in the tetrahydrobiopterin (BH₄) responsive mutant PAH proteins (I65T, R68S, R261Q, V388M and Y414C) with these enzymes possessing between 1.2% and 2.0% of the wild type PAH activity when SCMC was used as substrate. These same mutant proteins express between 23% and 76% of the wild type PAH activity when phenylalanine was used as the substrate. The PAH mutant proteins (R158Q, I174T and R408W) that result in the classical phenylketonuria (PKU) phenotype expressing 0.2–1.8% of the wild type PAH activity when using phenylalanine as substrate were found to have <0.1% of the wild type PAH activity when SCMC was used as the substrate. Mutations that result in PAH proteins retaining some residual PAH activity with phenylalanine as substrate have <2.0% residual activity when SCMC was used as a substrate. This investigation has led to the hypothesis that the S-oxidation polymorphism in man is a consequence of an individual carrying one mutant PAH allele which has resulted in the loss of the ability of the residual PAH protein to undertake the S-oxidation of SCMC in vivo.     

Pitfalls in phenylalanine loading test in the diagnosis of dopa-responsive dystonia

Phenylalanine (Phe) loading test is a useful tool in the differential diagnosis of dopa-responsive dystonia due to autosomal dominant or recessive GTP cyclohydrolase I (GTPCH) deficiency or autosomal recessive sepiapterin reductase (SR) deficiency. In these patients hepatic phenylalanine hydroxylase system is compromised due to subnormal tetrahydrobiopterin (BH₄) levels and hydroxylation of phenylalanine (Phe) to tyrosine (Tyr) is reduced with elevated Phe/Tyr ratio 1–2 h after oral Phe administration (100 mg/kg bw) administration. In healthy persons there is only a modest increase in Tyr production and blood Phe normalizes after 4 h. We report on a challenge with Phe (100 mg/kg bw) in a patient with dopa-responsive dystonia while on therapy with BH₄ and l-dopa. During Phe challenge Phe concentration remained below the normal range while a transient mild hypertyrosinemia was observed, leading to an extremely low Phe/Tyr ratio. A repeated test, after BH₄ withdrawal, reversed the findings and resulted normal. These data suggest activation of hepatic phenylalanine hydroxylase by BH₄. Thus, the Phe loading test should not be performed during substitution with BH₄.     

Human papillomavirus oncogene mRNA testing for the detection of anal dysplasia in HIV-positive men who have sex with men

BackgroundAnal human papillomavirus (HPV) infection and anal dysplasia are frequent in HIV-positive men who have sex with men (HIV + MSM), and progression of low-grade (LSIL) to high-grade squamous intraepithelial lesions (HSIL) or anal cancer (AC) occurs faster than in HIV-negative individuals. High-risk (HR)-HPV-E6/E7 oncogene mRNA testing has a higher specificity and a higher positive predictive value (PPV) than HR-HPV-DNA testing for detecting high-grade cervical lesions.ObjectiveTo evaluate the diagnostic accuracy of the NucliSENS-EasyQ HPV1.1 E6/E7-mRNA-assay for the detection of anal dysplasia in HIV + MSM.Study design289 intraanal swabs from HIV + MSM participating in a screening program that included anal cytology, high-resolution anoscopy and histology were analyzed. HR-HPV-DNA detection was performed by PCR and hybridization using a bead-based multiplex genotyping assay. E6/E7-mRNA detection of HR-HPV-types 16, 18, 31, 33 and 45 was performed using the NucliSENS-EasyQ assay.Results269 swabs had valid results in both test formats (111 normal, 10 ASCUS, 105 LSIL, 42 HSIL, 1 AC). For the detection of LSIL + (LSIL + HSIL + cancer) sensitivity, specificity, negative predictive value (NPV) and PPV were 80.4%, 26.4%, 52.5%, and 57.2% for HR-HPV-DNA testing, respectively, compared to 75.7%, 57.9%, 66.0% and 68.7% for E6/E7-mRNA testing. The respective values for the detection of HSIL/cancer were 95.3%, 26.1%, 96.7%, 19.7% for HR-HPV-DNA and 95.3%, 46.0%, 98.1%, 25.2% for E6/E7-mRNA detection.ConclusionCompared to HR-HPV-DNA detection, E6/E7-mRNA testing has an increased specificity (approximately two-fold), similar sensitivity and higher NPV and PPV for the detection of low- and high-grade anal dysplasia in HIV + MSM.     

Overexpression of recombinant human antiquitin in E. coli: Partial enzyme activity in selected ALDH7A1 missense mutations associated with pyridoxine-dependent epilepsy

Pyridoxine-dependent epilepsy (PDE) is an autosomal recessive disorder characterized by early onset seizures responsive to pyridoxine and caused by a defect in the α-aminoadipic semialdehyde dehydrogenase (antiquitin) gene (ALDH7A1). We selected four PDE-associated missense ALDH7A1 mutations, p.V367F, p.F410L, p.Q425R, and p.C450S, generated them in a recombinant human antiquitin cDNA with expression in E. coli at either 30 °C or 37 °C. One mutation, p.C450S, demonstrated substantial activity after expression at both temperatures, potentially contributing to milder biochemical and clinical phenotypes. The p.Q425R mutation yielded no activity at either temperature. The other two mutations yielded significant enzymatic activity at 30 °C and markedly reduced activity at 37 °C. For these latter three mutations, the markedly reduced or absent enzymatic activity resulting from expression at 37 °C may be consistent with pathogenicity.     

Prediction of antidepressant response in both 2.25xthreshold RUL and fixed high dose RUL ECT

Some forms of electroconvulsive therapy (ECT) can result in generalized seizures that lack efficacy, therefore physiological markers of treatment adequacy would be helpful. EEG measures of seizure quality, such as EEG regularity and post-ictal suppression, have largely supplanted seizure duration as a marker for seizure adequacy, yet no predictive algorithm has gained wide clinical acceptance. Electrographic seizure durations of less than 25 s still prompt re-stimulation in many settings. We re-examined the utility of EEG seizure duration and other measures of EEG seizure as predictors of antidepressant response to right unilateral (RUL) ECT.MethodsSeventy-two adult patients with major depression were randomized to either titrated RUL ECT at 2.25 times initial seizure threshold or RUL ECT at a fixed dose of 403 mC. Intent-to-treat responder status (defined by 60% reduction in HRSD scores and final score of 12 or less after the last RUL ECT session) was identified as the dependent variable in a nominal logistic regression model including EEG seizure quality candidate variables, controlled for age and gender.ResultsA model including EEG seizure duration, EEG regularity, post-ictal suppression, age and gender and randomization status was significantly predictive of intent-to-treat responder status at treatment 2 (R2 = .21 p < .003; N = 66) and treatment 4 (R2 = .27 p < .0004; N = 67). The model remained significant at these time points even when randomization status (titrated moderately suprathreshold vs. high fixed dosage) was removed (Treatment 2: R2 = .18 p < .007; Treatment 4: R2 = .23 p < .0007).ConclusionEEG markers of seizure adequacy, including EEG seizure duration, are modestly predictive of antidepressant response for both titrated moderately suprathreshold and high fixed dosage RUL ECT.     

Aberrant expression of cell cycle regulatory genes predicts overall and disease free survival in malignant pleural mesothelioma patients

BackgroundMalignant pleural mesothelioma (MPM) is a highly aggressive disease with a generally poor prognosis. Since escape from cell cycle checkpoint control is common in several solid tumors, the present study was performed to evaluate the role of some cell cycle regulatory genes in the development and progression of MPM.Patients and methodsAberrant expression of p14^ARF, p16^INK4A, p21^waf, p27^KIP, p53, mdm2 and Rb was assessed in 55 MPM cases from Egypt using immunohistochemistry and PCR techniques. Results were correlated with clinico-pathological prognostic factors, overall and disease free survival (OS&;DFS).ResultsAltered expression of p14^ARF, p16^INK4A, p21^waf, p27^KIP1, Rb, p53 and mdm2 proteins was detected in 50.9%, 54.5%, 53.3%, 61.8%, 53.3%, 58.2%, and 50.8% of cases, respectively. SV40 infection significantly correlated with p14^ARF, 16^INK4A, p27^kip1 and Rb aberrations (p = 0.014, p = 0.02, p = 0.01, p = ? 0.01). Asbestos exposure significantly correlated with p53, p21^waf and mdm2 aberrations (p = 0.001, p = 0.03, p = 0.02). On multivariate analysis PS ≥ 2, p27^KIP1 and Rb aberrations were independent prognostic factors for OS (p = 0.016, p = 0.011, p = 0.003) whereas on tumor recurrence, p27^KIP1 and Rb aberrations were independent prognostic factors for DFS (p = 0.002, p = 0.03, p = 0.01).ConclusionsMPM is a complex disease characterized by multiple genetic aberrations; some of them involve cell cycle regulatory genes. p14^ARF, p16^INK4A, Rb and p27^KIP1 seem to be involved in SV40-associated MPM whereas mdm2, p53 and p21^WAF are related to asbestos exposure. In addition to recurrence and PS, only p27^KIP1and Rb could be used as molecular prognostic markers in MPM.     

The mechanism of BH(4) -responsive hyperphenylalaninemia-As it occurs in the ENU1/2 genetic mouse model

The Pah^enu1/enu2 (ENU1/2) mouse is a heteroallelic orthologous model displaying blood phenylalanine (Phe) concentrations characteristic of mild hyperphenylalaninemia. ENU1/2 mice also have reduced liver phenylalanine hydroxylase (PAH) protein content (～20% normal) and activity (～2.5% normal). The mutant PAH protein is highly ubiquitinated, which is likely associated with its increased misfolding and instability. The administration of a single subcutaneous injection of l ‐Phe (1.1 mg l ‐Phe/g body weight) leads to an approximately twofold to threefold increase of blood Phe and phenylalanine/tyrosine (Phe/Tyr) ratio, and a 1.6‐fold increase of both nonubiquitinated PAH protein content and PAH activity. It also results in elevated concentrations of liver 6R‐l ‐erythro‐5,6,7,8‐tetrahydrobiopterin (BH₄), potentially through the influence of Phe on GTP cyclohydrolase I and its feedback regulatory protein. The increased BH₄ content seems to stabilize PAH. Supplementing ENU1/2 mice with BH₄ (50 mg/kg/day for 10 days) reduces the blood Phe/Tyr ratio within the mild hyperphenylalaninemic range; however, PAH content and activity were not elevated. It therefore appears that BH₄ supplementation of ENU1/2 mice increases Phe hydroxylation levels through a kinetic rather than a chaperone stabilizing effect. By boosting blood Phe concentrations, and by BH₄ supplementation, we have revealed novel insights into the processing and regulation of the ENU1/2‐mutant PAH. Hum Mutat 33:1464–1473, 2012. © 2012 Wiley Periodicals, Inc.     

Association between folate intake and melancholic depressive symptoms. A Finnish population-based study

BackgroundAn association between low blood folate levels and depressive symptoms (DS) has been reported in several epidemiological studies, but no studies have examined folate intake in melancholic or non-melancholic DS in population-based samples.MethodsThe aim of the study was to evaluate folate intake in DS with or without melancholic characteristics as a part of the Finnish diabetes prevention program (FIN-D2D). Altogether, 4500 randomly selected subjects aged 45–74 years were selected from the National Population Register. The study population (N = 2806, participation rate 62%) consisted of 1328 men and 1478 women. The health examinations were carried out in 2007 according to the WHO MONICA project. The assessment of DS was based on the Beck Depression Inventory (BDI, cut-off ≥ 10 points). A summary score of melancholic items in the BDI was used in dividing the participants with DS (N = 429) into melancholic (N = 138) and non-melancholic DS (N = 291) subgroups. Folate intake was assessed using a validated food frequency questionnaire (FFQ).ResultsDS associated linearly with gender specific tertiles of folate intake (p for linearity = 0.003). The OR for melancholic DS was 0.55 (95%CI 0.34 to 0.90) for the high tertile of folate intake versus the low (p for linearity = 0.018), while the ORs for non-melancholic DS were nonsignificant.LimitationsAssessment of DS was based on a self-rating scale, and the population was in advanced middle-aged.ConclusionsA low folate intake was associated with DS through its effect on melancholic DS.     

Changes in modes of hepatitis C infection acquisition and genotypes in southwest China

BackgroundThe shift in the distribution of HCV genotypes could have a significant impact on practical medical issues.ObjectivesTo describe the recent distribution and evolution of HCV genotypes in southwest China.Study designHCV genotypes were determined by nucleotide sequencing of the CE1 regions followed by phylogenic analysis with the published HCV genotype. HCV genotype distribution was analyzed according to patients’ age, risk exposure, and the first time of risk exposure.ResultsAmong the 371 cases, subtypes 1a (0.8%), 1b (42.0%), 2a (9.7%), 3a (12.1%), 3b (21.0%), 4a (0.3%), and 6a (14.0%) were found. Genotypes 3 and 6 were significantly more frequent (85.4%) among IDUs than among other subjects (32.5%, P < 0.001), they were also more frequent among subjects aged 40 years or under (63.6%) than older patients (21.6%, P < 0.001), among patients infected after 1997 (54.4%) than those infected before 1997 (27.3%, P = 0.001). Age 40 years or under (P < 0.001) and infection via IDU (P < 0.001) were independently associated with genotypes 3 and 6 in the multivariate stepwise logistic regression analysis. IDU was detected as a cause of infection in 27.8% of HCV cases; it was more frequent among younger patients (40.4%) than older ones (7.1%, P < 0.001), among patients infected after 1997 (40.3%) than those infected before 1997 (16.2%, P < 0.001).ConclusionIn southwest China, the relative prevalence of genotypes 3 and 6 has increased significantly, and that of genotypes 1b and 2a has declined significantly among young patients. This shift in distribution was associated with changes in the modes of HCV acquisition.     

Pyrimethamine increases β-hexosaminidase A activity in patients with Late Onset Tay Sachs

ObjectiveTo assess whether or not pyrimethamine (PMT) can be used to enhance β-hexosaminidase A activity (HexA) in subjects with Late Onset Tay Sachs (LOTS), we studied the effect of incremental doses of PMT in vivo in 9 LOTS patients carrying the αG269S/c.1278insTACT mutations.MethodsPMT treatment was initiated at a dose of 6.25 mg, increasing gradually up to a maximal allowable dose of 75 mg daily at 4–6 weeks intervals for a total of up 10 months. Mean patients' age was 37.9 ± 16.1 yrs (range 20–67 years).ResultsLymphocyte HexA activity rose in all subjects, peaking at 78 ± 30% over baseline activity (mean ± SD; range 36–114%). The optimal PMT dose varied considerably, averaging at 30 ± 24.1 mg (range—6.25–75 mg, daily). Further increase in PMT beyond the optimal dose was associated with gradual loss of effect on lymphocyte HexA. Improvement in speech was seen within several weeks in 4 out of 9 subjects, mostly paralleling the initial increment in HexA. Mood stabilization was also perceived in 3 subjects, but this was more difficult to assess due to the concomitant use of psychotropic/mood stabilizing agents. Reversible decline in motor activity manifesting predominantly in more frequent falls was seen in 3 subjects when the PMT dose was increased beyond the peak effect generating dose.ConclusionsPMT therapy can increase HexA activity in LOTS in vivo. Optimal doses should be tailored individually to avoid loss of biochemical effects. Clear cut neurological and psychiatric effects are difficult to discern at this time, mostly due to short term study follow up and large inter-individual variability.     

Prevalence and correlates of the proposed DSM-5 diagnosis of Chronic Depressive Disorder

ContextThe draft proposal to add Chronic Depressive Disorder to DSM-5 will combine DSM-IV Dysthymic Disorder and Major Depressive Disorder, with chronic specifier, into a single diagnosis.ObjectiveThe objective of this study is to estimate the prevalence and correlates of the proposed DSM-5 diagnosis of Chronic Depressive Disorder using unit record data from the 2007 Australian National Survey of Mental Health and Wellbeing.DesignSecondary analysis of a nationally representative household survey.SettingUrban and rural census tracts.ParticipantsOne individual between the ages of 16 and 85 years from 8841 households was interviewed for the survey.Main outcome measureLifetime prevalence estimates for chronic and non-chronic depression were determined using data from the World Health Organization's Composite International Diagnostic Interview, version 3.0 (WMH-CIDI 3.0).ResultsChronic depression of at least two years' duration had a lifetime prevalence of 4.6% (95% CI: 3.9–5.3%) and was found in 29.4% (95% CI: 25.6–33.3%) of individuals with a lifetime depressive disorder. Higher rates of psychiatric co-morbidity (OR = 1.42; 95% CI = 1.26–1.61), older age (OR = 1.04; 95% CI = 1.02–1.05), a younger age of onset (OR = 0.97; 95% CI = 0.95–0.98) and more frequent episodes of depression (OR = 1.75; 95% CI = 1.07–2.86) were found to be significant correlates of chronic depression. The first episode of depression for individuals with chronic depression often developed after the death of someone close (OR = 2.38; 95% CI 1.16–5.79).ConclusionsChronic depression is highly prevalent among community-residing persons and has a set of correlates that discriminate it from non-chronic depression. The distinction between chronic and non-chronic depression proposed for DSM-5, in the form of Chronic Depressive Disorder, seems to be warranted.     

A 40-week double-blind aripiprazole versus lithium follow-up of a 12-week acute phase study (total 52 weeks) in bipolar I disorder

BackgroundThis study followed manic or mixed bipolar I subjects for an additional 40 weeks after initial randomization to 12 weeks of lithium versus aripiprazole monotherapy. This is the only long-term, double-blind study comparing lithium and aripiprazole.MethodsPatients continued receiving either aripiprazole 15 or 30 mg/day, or lithium 900, 1200 or 1500 mg/day in a double-blind fashion for 40 weeks after completing a 12-week double-blind study (52 weeks total treatment). Efficacy endpoints included adjusted mean change from baseline to Week 52 in Young Mania Rating Scale (YMRS) total score and Montgomery–Åsberg Depression Rating Scale (MADRS) total scores (observed cases). Remission was defined as YMRS total score ≤ 12. Safety and tolerability were also assessed.ResultsOf the 66 patients who entered the extension phase, only 20 patients (30.3%) completed the entire phase (aripiprazole n = 7; lithium n = 13). The significant improvement that occurred over the first 12 weeks was maintained over the 40 weeks of blinded continuation (from Week 12 through Week 52). The most common treatment-emergent adverse events in the extension phase for aripiprazole were akathisia, headache, somnolence, anxiety and nasopharyngitis (all 8%), and for lithium were insomnia (15.8%), headache (13.2%), diarrhea (13.2%) and vomiting (10.5%). Mean weight change was + 2.71 kg for lithium and + 5.66 kg for aripiprazole (p = 0.46).LimitationsThis trial was not powered to statistically compare active treatments, and long-term completion rates were low in both groups.ConclusionsAripiprazole monotherapy appears to be equivalently useful to lithium for the extended treatment of mixed or manic bipolar disorder patients.     

DNAJC12 deficiency: A new strategy in the diagnosis of hyperphenylalaninemias

Patients with hyperphenylalaninemia (HPA) are detected through newborn screening for phenylketonuria (PKU). HPA is known to be caused by deficiencies of the enzyme phenylalanine hydroxylase (PAH) or its cofactor tetrahydrobiopterin (BH₄). Current guidelines for the differential diagnosis of HPA would, however, miss a recently described DNAJC12 deficiency. The co-chaperone DNAJC12 is, together with the 70 kDa heat shock protein (HSP70), responsible for the proper folding of PAH. All DNAJC12-deficient patients investigated to date responded to a challenge with BH₄ by lowering their blood phenylalanine levels. In addition, the patients presented with low levels of biogenic amine in CSF and responded to supplementation with BH₄, L-dopa/carbidopa and 5-hydroxytryptophan. The phenotypic spectrum ranged from mild autistic features or hyperactivity to severe intellectual disability, dystonia and parkinsonism. Late diagnosis result in permanent neurological disability, while early diagnosed and treated patients develop normally. Molecular diagnostics for DNAJC12 variants are thus mandatory in all patients in which deficiencies of PAH and BH₄ are genetically excluded.     

Mechanisms underlying responsiveness to tetrahydrobiopterin in mild phenylketonuria mutations

A subtype of phenylalanine hydroxylase (PAH) deficiency that responds to cofactor (tetrahydrobiopterin, BH4) supplementation has been associated with phenylketonuria (PKU) mutations. The underlying molecular mechanism of this responsiveness is as yet unknown and requires a detailed in vitro expression analysis of the associated mutations. With this aim, we optimized the analysis of the kinetic and cofactor binding properties in recombinant human PAH and in seven mild PKU mutations, i.e., c.194T>C (p.I65T), c.204A>T (p.R68S), c.731C>T (p.P244L), c.782G>A (p.R261Q), c.926C>T (p.A309V), c.1162G>A (p.V388M), and c.1162G>A (p.Y414C) expressed in E. coli. For p.I65T, p.R68S, and p.R261Q, we could in addition study the equilibrium binding of BH4 to the tetrameric forms by isothermal titration calorimetry (ITC). All the mutations resulted in catalytic defects, and p.I65T, p.R68S, p.P244L, and most probably p.A309V, showed reduced binding affinity for BH4. The possible stabilizing effect of the cofactor was explored using a cell-free in vitro synthesis assay combined with pulse-chase methodology. BH4 prevents the degradation of the proteins of folding variants p.A309V, p.V388M, and p.Y414C, acting as a chemical chaperone. In addition, for wild-type PAH and all mild PKU mutants analyzed in this study, BH4 increases the PAH activity of the synthesized protein and protects from the rapid inactivation observed in vitro. Catalase and superoxide dismutase partially mimic this protection. All together, our results indicate that the response to BH4 substitution therapy by PKU mutations may have a multifactorial basis. Both effects of BH4 on PAH, i.e., the chemical chaperone effect preventing protein misfolding and the protection from inactivation, may be relevant mechanisms of the responsive phenotype.     

Clinical and biological monitoring of nutritional status in severe burns

Aim of the studyBurn patients are subject to hypermetabolism and catabolic states. Aim was to evaluate our current practice in nutrition.MethodsTwenty-one severely burned patients were prospectively included during three months period. Body weight was measured at least two times in a week during all stay in burn ICU. Biological markers of inflammation (C-reactive protein, CRP) and nutrition (prealbumin) were performed weekly. Protocol included early nasogastric feeding, tolerated gastric stasis less than 250 mL at four hours nasogastric aspirations, caloric target value of 40 Kcal/kg per day and measurement of total daily calorie intakes.ResultsPatient demographics showed a mean percent total body surface burn of 51.1 ± 27 % (range 20–90), age of 38.7 ± 13.1 years (range 18–67) and 57.3 % of smoke inhalation. All patients were ventilated and 19 patients survived. Length of stay was 75.7 ± 47 days (range 22–184). Patients received only 58.9 ± 10 % of calorie intakes recommended by French burn society. Loss of body mass was 15.2 ± 9 kg (range 3–31) or 19.1 ± 10 % of admission weight (range 5–37). Erosion of body mass was not correlated with burned surface (p = 0.08), calorie intakes (p = 0.26), smoke inhalation (p = 0.46), lengths of stay (p = 0.53), lengths of ventilation (p = 0.08) or nutrition (p = 0.12), days of antibiotic (p = 0.72), number of dressing changes (p = 0.6) or surgery (p = 0.64). Biological parameters showed CRP decreasing and prealbumin improving values.ConclusionNew strategies of nutrition are necessary to improve outcome and reduce body mass loss in burns.     

Pretreatment cerebral metabolic activity correlates with antidepressant efficacy of vagus nerve stimulation in treatment-resistant major depression: A potential marker for response?

BackgroundPretreatment brain activity in major depressive disorder correlates with response to antidepressant therapies, including pharmacotherapies and transcranial magnetic stimulation. The purpose of this trial was to examine whether pretreatment regional metabolic activity in selected regions of interest (ROIs) predicts antidepressant response following 12 months of vagus nerve stimulation (VNS) in 15 patients with treatment-resistant major depression (TRMD).MethodsFluorodeoxyglucose positron emission tomography (FDG PET) was used to assess regional mean relative cerebral metabolic rate for glucose (CMRGlu) in four ROIs (anterior insular, orbitofrontal, anterior cingulate, and dorsolateral prefrontal cortices) at baseline (prior to VNS activation). Depression severity was assessed at baseline and after 12 months of VNS using the Hamilton Depression Rating Scale (HDRS), with response defined as ≥ 50% reduction in HDRS from baseline.ResultsBaseline CMRGlu in the anterior insular cortex differentiated VNS responders (n = 11) from nonresponders (n = 4) and correlated with HDRS change (r = .64, p = .01). In a regression analysis, lower anterior insular cortex CMRGlu (p = .004) and higher orbitofrontal cortex CMRGlu (p = .047) together predicted HDRS change (R² = .58, p = .005). In a whole brain, voxel-wise analysis, baseline CMRGlu in the right anterior insular cortex correlated with HDRS change (r = .78, p = .001).LimitationsSample size was small, limiting statistical power; patients remained on their psychiatric medications; study was open-label and uncontrolled.ConclusionsThis preliminary study suggests that pretreatment regional CMRGlu may be useful in predicting response to VNS in TRMD patients.     

Depressive symptoms, physical activity, and weight gain in premenopausal Latina and White women

ObjectivesDescribe changes and examine the association between depressive symptoms, physical activity, body mass index (BMI), and perceived health among Latina (n = 81) and White (n = 151) women in the first year of the late-premenopausal stage.MethodsLongitudinal study focused on the biopsychosocial health of midlife women (ages 40–50 years) with regular menstrual cycles and not taking hormones. Frequency of depressive symptoms, BMI, waist to hip ratios, and self-reported physical activity levels were obtained at 6-month intervals and perceived health at 12 months. Results are reported here for 232 women who remained premenopausal (low FSH/regular cycles) for the first 12 months.ResultsDepressive symptoms were similar for Latinas (11.1 ± 9.8) and Whites (11.1 ± 8.2) and increased by 2.3 points over time for all women. Latinas had higher BMI (28 ± 5.7, p < 0.01) than Whites (26 ± 5.7). Body weight increased an average of 1.2 lbs over 12 months for both groups. Both groups reported sub-optimal levels of physical activity that did not change over time, but Latinas reported higher levels at all 3 time points. Controlling for age and ethnicity, women in service or agricultural occupations reported higher activity levels than women in other roles. Better perceived health at 12 months was predicted by lower baseline BMI (r = 0.43, p < 0.01) and fewer depressive symptoms (r = 0.38, p < 0.01).ConclusionsDepressive symptoms, weight gain and physical inactivity among women in the late-premenopausal stage point to the need for interventions focused on causal factors other than hormonal changes and menopause.