Physicochemical properties of starches and expression and activity of starch biosynthesis-related genes in sweet potatoes.

The functional properties of starches from six sweet potato varieties containing various starch components and structures were studied in an attempt to identify starch sources for industrial uses. Tainan 18 (TNN18) with high-amylose (AM) starch exhibited high setback and breakdown viscosities, high water solubility at 85°C but low swelling volume at 65°C, and high hardness and adhesiveness; in contrast, the low-AM starch of Tainung 31 (TNG31) had opposite characteristics. Seven genes related to starch biosynthesis were tested, and GBSS, SS, SBEII, ISA, and AGPase were highly expressed in TNN18 and TNG31; however, transcript levels in DBE and SBE were extremely low. GBSS and SS activity reflected the abundance of GBSS and SS mRNA in TNG31 and TNN18, and expression of AGPase, GBSS, SS, and SBE in TNN18 substantially increased content of AM. The expression and activity of DBE had a significant effect on TNG31 with increased AP content.

Searching for a neurobiological basis for self-medication theory in ADHD comorbid with substance use disorders: an in vivo study of dopamine transporters using (99m)Tc-TRODAT-1 SPECT.

PURPOSE: Attention-deficit/hyperactivity disorder (ADHD) and substance use disorders (SUD) frequently co-occur. Although several studies have shown changes in striatal dopamine transporter (DAT) density in these disorders, little is known about the neurobiological basis of the comorbidity. The aim of this study was to evaluate striatal DAT density in treatment-naive ADHD adolescents with SUD (ADHD + SUD) and without SUD (ADHD), compared to SUD adolescents without ADHD (SUD) and healthy control subjects (HC). PATIENTS AND METHODS: Sixty-two male age-matched subjects diagnosed with DSM-IV criteria were included: ADHD + SUD (n = 18), SUD (n = 14), HC (n = 19), and ADHD (n = 11). Urine tests confirmed participants' drug use. All subjects performed SPECT scans with Tc-TRODAT-1 to evaluate DAT density in the striatum. RESULTS: The mean right striatum specific binding were 1.68 (ADHD), 1.38 (ADHD + SUD), 1.19 (HC), 1.17 (SUD), and in left striatum 1.65 (ADHD), 1.39 (ADHD + SUD), 1.19 (HC), and 1.17 (SUD). The ADHD group presented significantly higher striatal DAT density compared with ADHD + SUD, SUD, and HC groups. Adolescents with ADHD + SUD had significantly lower DAT density than those with ADHD, but significantly higher DAT density than those with SUD only and no significant difference from the healthy control group. CONCLUSION: The ADHD + SUD group had lower striatal DAT density in comparison with ADHD without SUD. It is possible to speculate that the use of cannabis and cocaine is responsible for the lower striatal DAT density in this group which would help in understanding the neurobiological basis for the self-medication theory in ADHD adolescents.

Higher striatal dopamine transporter density in PTSD: an in vivo SPECT study with [(99m)Tc]TRODAT-1.

RATIONALE: Some evidence suggests a hyperdopaminergic state in posttraumatic stress disorder (PTSD). The 9-repetition allele (9R) located in the 3' untranslated region of the dopamine transporter (DAT) gene (SLC6A3) is more frequent among PTSD patients. In vivo molecular imaging studies have shown that healthy 9R carriers have increased striatal DAT binding. However, no prior study evaluated in vivo striatal DAT density in PTSD. OBJECTIVES: The objective of this study was to evaluate in vivo striatal DAT density in PTSD. METHODS: Twenty-one PTSD subjects and 21 control subjects, who were traumatized but asymptomatic, closely matched comparison subjects evaluated with the Clinician-Administered PTSD Scale underwent a single-photon emission computed tomography scan with [(99m)TC]-TRODAT-1. DAT binding potential (DAT-BP) was calculated using the striatum as the region of the interest and the occipital cortex as a reference region. RESULTS: PTSD patients had greater bilateral striatal DAT-BP (mean ± SD; left, 1.80 ± 0.42; right, 1.78 ± 0.40) than traumatized control subjects (left, 1.62 ± 0.32; right, 1.61 ± 0.31; p = 0.039 for the left striatum and p = 0.032 for the right striatum). CONCLUSIONS: These results provide the first in vivo evidence for increased DAT density in PTSD. Increases in DAT density may reflect higher dopamine turnover in PTSD, which could contribute to the perpetuation and potentiation of exaggerated fear responses to a given event associated with the traumatic experience. Situations that resemble the traumatic event turn to be interpreted as highly salient (driving attention, arousal, and motivation) in detriment of other daily situations.

Higher dopamine transporter density in Parkinson's disease patients with depression.

RATIONALE: Depression is a frequent non-motor symptom in Parkinson's disease (PD) with increasing rates with the progression of the disease. Molecular imaging studies have shown a reduction of dopamine transporter (DAT) density in depressed PD patients (dPD); however, DAT role in the pathophysiology of PD depression is not clear since clinical matching was inappropriate and DAT reduction could be attributed to PD severity. OBJECTIVES: To further examine the role of DAT in PD depression, this study compared thoroughly matched depressed vs. non-depressed PD patients (ndPD). MATERIALS AND METHODS: Twenty PD patients (n = 10 ndPD; n = 10 dPD) matched for age and disease severity were submitted to brain SPECT imaging with [(99m)Tc]-TRODAT-1, a DAT radioligand. DAT-binding potential was calculated using regions of interest bilaterally drawn in the striatum, caudate, and putamen. Depression was defined according to Beck Depression Inventory (BDI; cut-off >18). RESULTS: Mean BDI scores were higher in dPD (25.0 +/- 5.6) than in ndPD patients (8.0 +/- 1.9, p < 0.0001). DAT density was greater on dPD especially in the left caudate (dPD 0.87 +/- 0.19 vs. ndDP 0.69 +/- 0.18, p = 0.02) and right putamen (dPD 0.37 +/- 0.07 vs. ndPD 0.28 +/- 0.13, p = 0.03) than in ndPD patients. CONCLUSION: Our results suggest that in vivo DAT density is increased in dPD patients as compared to ndPD, suggesting that DAT is implicated in the pathophysiology of PD depression.

Evaluation of patients with Clinically Unclear Parkinsonian Syndromes submitted to brain SPECT imaging using the technetium-99m labeled tracer TRODAT-1.

Despite its relatively high prevalence Parkinson's Disease (PD) is still misdiagnosed in approximately 25% of cases. In this study our aim was to evaluate patients with Clinically Unclear Parkinsonian Syndromes (CUPS) submitted to brain SPECT imaging using the technetium-99m labeled Dopamine Transporter (DAT) tracer TRODAT-1. We recruited 15 subjects with CUPS and matched them with 13 patients with probable PD and 13 healthy control subjects (HCS). A SPECT with TRODAT-1 was performed at the baseline evaluation and patients from the CUPS were followed-up for 2-years to ensure or not PD diagnosis ("gold-standard"). The mean+/-SD results from Right and Left striatum Binding Potential (BP) were, respectively, 1.08+/-0.20 and 1.04+/-0.16 in the HCS group, 0.47+/-0.16 and 0.53+/-0.17 in the PD group, and 0.68+/-0.11 and 0.84+/-0.17 in the CUPS group. The rate of disagreement between baseline SPECT in the CUPS group as compared to the "gold standard" diagnosis (clinical diagnosis of PD on follow-up) was of 20%. The sensitivity of the SPECT with TRODAT-1 was 100%, while specificity was 70%. In conclusion, our data provided further information about the role of the technetium-99m labeled tracer TRODAT-1 as a biomarker of DAT reduction that can also be used in the diagnosis of patients with CUPS.

Degenerative parkinsonism in patients with psychogenic parkinsonism: A dopamine transporter imaging study.

OBJECTIVES: To evaluate patients with "clinically established" psychogenic parkinsonism (PsyP) using single-photon emission computer tomography (SPECT) with the technetium-99m labeled tracer TRODAT-1, a dopamine transporter (DAT) ligand, and investigate whether these patients have an underlying degenerative parkinsonism. PATIENTS AND METHODS: Five patients with PsyP were assessed using demographic data, standard clinical scales for Parkinson's Disease (PD), and a neuropsychiatric interview. DAT imaging using SPECT with TRODAT-1 was performed, and values for caudate/putamen DAT binding potentials (BP) registered. Patients with PsyP were matched with PD (n=5) and healthy control subjects (n=5). RESULTS: The mean age (years-old) at first evaluation in the PsyP group was 37.4+/-3.7, and the mean disease duration (years) was 3.9+/-1.2. DAT BPs (means+/-standard deviations) on right/left caudate were, respectively, 0.69+/-0.18 and 0.70+/-0.18 in the PD group versus 1.17+/-0.06 and 1.12+/-0.10 in the control group. DAT BPs on right/left putamen were, respectively, 0.48+/-0.10 and 0.45+/-0.06 in the PD group versus 1.10+/-0.10 and 1.21+/-0.43 in the control group. Two out of five patients from the PsyP group had values for DAT BP in the putamen under the cut-off (< or =0.70) for controls, implying pre-synaptic dopaminergic deficit. CONCLUSIONS: Our data in this small group of patients suggest that DAT imaging is a tool that may help in the identification of underlying degenerative parkinsonism in PsyP.

The posttraumatic stress disorder project in Brazil: neuropsychological, structural and molecular neuroimaging studies in victims of urban violence.

BACKGROUND: Life trauma is highly prevalent in the general population and posttraumatic stress disorder is among the most prevalent psychiatric consequences of trauma exposure. Brazil has a unique environment to conduct translational research about psychological trauma and posttraumatic stress disorder, since urban violence became a Brazilian phenomenon, being particularly related to the rapid population growth of its cities. This research involves three case-control studies: a neuropsychological, a structural neuroimaging and a molecular neuroimaging study, each focusing on different objectives but providing complementary information. First, it aims to examine cognitive functioning of PTSD subjects and its relationships with symptomatology. The second objective is to evaluate neurostructural integrity of orbitofrontal cortex and hippocampus in PTSD subjects. The third aim is to evaluate if patients with PTSD have decreased dopamine transporter density in the basal ganglia as compared to resilient controls subjects. This paper shows the research rationale and design for these three case-control studies. METHODS AND DESIGN: Cases and controls will be identified through an epidemiologic survey conducted in the city of São Paulo. Subjects exposed to traumatic life experiences resulting in posttraumatic stress disorder (cases) will be compared to resilient victims of traumatic life experiences without PTSD (controls) aiming to identify biological variables that might protect or predispose to PTSD. In the neuropsychological case-control study, 100 patients with PTSD, will be compared with 100 victims of trauma without posttraumatic stress disorder, age- and sex-matched controls. Similarly, 50 cases and 50 controls will be enrolled for the structural study and 25 cases and 25 controls in the functional neuroimaging study. All individuals from the three studies will complete psychometrics and a structured clinical interview (the Structured Clinical Interview for DSM-IV and the Clinician-Administered PTSD Scale, Beck Anxiety Inventory, Beck Depression Inventory, Global Assessment of Function, The Social Adjustment Scale, Medical Outcomes Study 36-Item Short-Form Health Survey, Early Trauma Inventory, Clinical global Impressions, and Peritraumatic Dissociative Experiences Questionnaire). A broad neuropsychological battery will be administered for all participants of the neuropsychological study. Magnetic resonance scans will be performed to acquire structural neuroimaging data. Single photon emission computerized tomography with [(99m)Tc]-TRODAT-1 brain scans will be performed to evaluate dopamine transporters. DISCUSSION: This study protocol will be informative for researchers and clinicians interested in considering, designing and/or conducting translational research in the field of trauma and posttraumatic stress disorder.

Clinical and molecular neuroimaging characteristics of Brazilian patients with Parkinson's disease and mutations in PARK2 or PARK8 genes.

OBJECTIVE: To describe clinical and neuroimaging (SPECT) characteristics of Brazilian patients with Parkinson's disease (PD) and mutations in PARK2 or PARK8 genes. METHOD: A total of 119 patients meeting clinical criteria for PD were evaluated. RESULTS: Of all patients studied, 13 had mutations in either PARK2 (n=9) or PARK8 genes (n=4). No statistically significant differences in clinical characteristics in both groups were seen. SPECT with [99mTc] TRODAT-1 showed significant differences between patient and control and the most remarkable difference was between PARK2 and control. CONCLUSION: The study found a frequency of mutation of 10.1% and it was most commonly seen in women. These patients had long disease course and high rates of dyskinesia after L-DOPA use. PARK8 patients did not have a relevant family history of PD.

Clinical and molecular neuroimaging characteristics of Brazilian patients with Parkinson's disease and mutations in PARK2 or PARK8 genes / Características clínicas e de neuroimagem molecular de pacientes brasileiros com doença de Parkinson e mutações nos genes PARK2 ou PARK8

OBJECTIVE: To describe clinical and neuroimaging (SPECT) characteristics of Brazilian patients with Parkinson's disease (PD) and mutations in PARK2 or PARK8 genes. METHOD: A total of 119 patients meeting clinical criteria for PD were evaluated. RESULTS: Of all patients studied, 13 had mutations in either PARK2 (n=9) or PARK8 genes (n=4). No statistically significant differences in clinical characteristics in both groups were seen. SPECT with [99mTc] TRODAT-1 showed significant differences between patient and control and the most remarkable difference was between PARK2 and control. CONCLUSION: The study found a frequency of mutation of 10.1 percent and it was most commonly seen in women. These patients had long disease course and high rates of dyskinesia after L-DOPA use. PARK8 patients did not have a relevant family history of PD.

OBJETIVO: Descrever as características clínicas e de neuroimagem (SPECT) de pacientes brasileiros com doença de Parkinson e mutações PARK2 e PARK8. MÉTODO: Foram avaliados 119 pacientes com critérios clínicos para a doença de Parkinson. RESULTADO: Entre os pacientes avaliados foram encontrados 13 pacientes com mutação nos genes PARK2 (n=9) ou PARK8 (n=4). Não houve diferença significativa na avaliação das características clínicas entre os dois grupos. Os resultados de SPECT mostraram diferenças significativas quanto ao potencial de ligação do [99mTc] TRODAT-1 SPECT entre pacientes vs. controle, sendo a diferença mais pronunciada entre PARK2 e controle. CONCLUSÃO: A freqüência de mutação encontrada foi 10,1 por cento, sendo mais comum em mulheres. Estes pacientes apresentavam longo tempo de doença e alta prevalência de discinesias associadas ao uso da levodopa. Nossos pacientes com PARK8 não apresentaram uma história familiar relevante de doença de Parkinson.

Molecular imaging studies in Parkinson disease: reducing diagnostic uncertainty.

BACKGROUND: The diagnosis of Parkinson disease (PD) is based on clinical criteria but misdiagnosis is as high as 25% of cases as confirmed by anatomic-pathologic studies. Since the introduction of in vivo molecular imaging techniques using Single-Photon Emission Computed Tomography and Positron Emission Tomography, the diagnosis of PD became more reliable by assessing dopaminergic and even nondopaminergic systems. REVIEW SUMMARY: The purpose of this article is to critically review the current data on molecular neuroimaging focusing on the nigrostriatal circuitry and providing useful information on the role of these new imaging techniques in the management of clinically unclear cases of PD. CONCLUSIONS: Patients with essential tremor, psychogenic Parkinsonism or drug-induced Parkinsonism can be differentiated from PD in doubtful situations using molecular imaging techniques evaluating striatal dopamine transporters (DAT). However, in patients with vascular Parkinsonism, atypical Parkinsonism and Parkinsonism associated with dementia DAT scans have less diagnostic usefulness. Scans with non-DAT tracers (ie, D2 dopamine receptors) are necessary together with long-term clinical follow-up, and rescans to improve diagnostic accuracy.