Thyroid hypofunction in Down’s syndrome

Oxidative stress affecting the thyroxin biosynthesis might explain the proneness of patients with Down's syndrome (DS) (trisomia 21) to develop hypothyroidism. Thyroideal cells are exposed to endogenous H2O2 that acts as a cofactor for the iodination of thyroxin precursors. The gland has high levels of selenium-containing proteins, including peroxide-detoxicating enzyme proteins. The object of the present study was to explore the hypothesis of a role of an imbalance between toxic oxygen production and protective metalloenzymes during the development of thyroid hypofunction in DS patients. We analyzed serum levels of thyroid hormones and trace metals in 38 institutionalized adults with DS, using mentally retarded subjects matched for age, sex, and behavioral function as controls. The DS patients had significantly lower mean values of free thyroxin (fT4) and increased TSH (thyroid stimulating hormone), as compared to the controls. They had lower serum selenium than the controls. A positive correlation was observed between serum concentrations of fT4 and selenium in the DS patients (r = 0.393, p < 0.05). No significant differences were found between the fT4 or the TSH concentrations in the patients with and without circulating antithyroid autoantibodies. Our results support the suggestion that thyroid hypofunction in patients with Down's syndrome in some way is linked to the low serum levels of selenium found in these patients. It is suggested that selenium-containing proteins are involved in thyroid hormonal synthesis, by protecting biosynthetic processes against the toxicity of free oxygen radicals.     

CASP3 protein expression by flow cytometry in Down’s syndrome subjects

Down’s syndrome (DS), the most common chromosomal disorder, is caused by 21 trisomy and is featured by intellectual disability. Subjects with DS can develop some traits of Alzheimer disease (AD) at an earlier age than subjects without trisomy 21. Apoptosis is a programmed cell death process under both normal physiological and pathological conditions. Caspase-3 (CASP3) plays an important role in neuronal death during nervous system development and under certain pathological conditions. Furthermore, in vitro and in vivo studies report elevated expression and activation of CASP3 in models of AD. On this account, the expression of CASP3 gene was evaluated in cultures of fibroblasts of DS and normal subjects by flow cytometry. CASP3 protein was up-regulated in fibroblasts of DS. The data obtained from this study strengthen the hypothesis that the over-expression of CASP3 gene could have a role in the activation of the apoptotic pathways acting in the neurodegenerative processes in DS.     

Combinations of PARP Inhibitors with Temozolomide Drive PARP1 Trapping and Apoptosis in Ewing’s Sarcoma

Ewing’s sarcoma is a malignant pediatric bone tumor with a poor prognosis for patients with metastatic or recurrent disease. Ewing’s sarcoma cells are acutely hypersensitive to poly (ADP-ribose) polymerase (PARP) inhibition and this is being evaluated in clinical trials, although the mechanism of hypersensitivity has not been directly addressed. PARP inhibitors have efficacy in tumors with BRCA1/2 mutations, which confer deficiency in DNA double-strand break (DSB) repair by homologous recombination (HR). This drives dependence on PARP1/2 due to their function in DNA single-strand break (SSB) repair. PARP inhibitors are also cytotoxic through inhibiting PARP1/2 auto-PARylation, blocking PARP1/2 release from substrate DNA. Here, we show that PARP inhibitor sensitivity in Ewing’s sarcoma cells is not through an apparent defect in DNA repair by HR, but through hypersensitivity to trapped PARP1-DNA complexes. This drives accumulation of DNA damage during replication, ultimately leading to apoptosis. We also show that the activity of PARP inhibitors is potentiated by temozolomide in Ewing’s sarcoma cells and is associated with enhanced trapping of PARP1-DNA complexes. Furthermore, through mining of large-scale drug sensitivity datasets, we identify a subset of glioma, neuroblastoma and melanoma cell lines as hypersensitive to the combination of temozolomide and PARP inhibition, potentially identifying new avenues for therapeutic intervention. These data provide insights into the anti-cancer activity of PARP inhibitors with implications for the design of treatment for Ewing’s sarcoma patients with PARP inhibitors.     

Prognostic value of HIF-1α expression in patients with gastric cancer

The role of hypoxia-inducible factors-1 alpha (HIF-1α) expression in gastric cancer remains controversial. We performed a systematic review of the literature with meta-analysis. Electronic databases were used to identify published studies before December 1, 2012. Pooled hazard ratio (HR) or odds ratio (OR) with 95 % confidence interval (95 % CI) was used to estimate the strength of the association between HIF-1α expression and survival of gastric cancer patients. Heterogeneity and publication bias were also assessed. Final analysis of 1,268 patients from 9 eligible studies was performed. High HIF-1α expression was significantly correlated with poor overall survival (OS) of gastric cancer patients (HR = 2.14, 95 % CI = 1.32–3.48). Subgroup analysis indicated that HIF-1α over-expression had an unfavorable impact on OS in Asian patients (HR = 2.35, 95 % CI = 1.41–3.92). Moreover, up-regulation of HIF-1α was significantly associated with the depth of invasion (OR = 2.49, 95 % CI = 1.28–4.83), lymph node metastasis (OR = 2.15, 95 % CI = 1.27–3.66), and vascular invasion (OR = 2.23, 95 % CI = 1.20–4.14). HIF-1α expression might be a predicative factor of poor prognosis for gastric cancer particularly in Asia.     

Serum neutrophil gelatinase-B associated lipocalin (NGAL) levels in Down’s syndrome patients

Neutrophil gelatinase-associated lipocalin (NGAL) is a group of proteins with different functions.NGAL is released by different cell types such as epithelial cell, hepatocytes and renal tubular cells during inflammation and after cell injury. Expression of NGAL is induced under various pathophysiological conditions such as infection, cancer, inflammation, kidney injury, cardiovascular disease, burn injury, and intoxication, which has an important anti-apoptotic and anti-inflammatory role.Subjects with Down's syndrome (DS) are affected by many pathological age related conditions such as mental retardation, Alzheimer's disease, immune defects and increased susceptibility to infections. The aim of this study is to evaluate possible use of NGAL as a marker of inflammatory status for allow an early diagnosis of inflammatory disease such as autoimmune disease in DS patients, that are more susceptible to these pathologies, especially in elderly subjects.In this study were recruited 3 groups of DS subjects (children, adults and elderly) and compared them to healthy control group.The molecules of interest was determinated by immuno-enzymatic assay (ELISA).Our results show that NGAL plasmatic level was significantly higher in DS patients compared to healthy controls. Moreover NGAL levels increase in correlation with the age, and showed a significantly correlation between the increase with the severity of disease.DS is characterized by an enhancement of gene production such as GART, SOD-1 and CBS that encode specific protein and enzyme involved in hydrogen peroxide and superoxide production, species highly cytotoxic implicated in inflammation and ageing.NGAL may have the potential application to ameliorate the toxicity induced by oxidative stress conditions such as Alzheimer's disease, thalassemia, cardiovascular disease, burn injury, transplantation, diabetes, and aging.     

Down syndrome’s brain dynamics: analysis of fractality in resting state

To the best knowledge of the authors there is no study on nonlinear brain dynamics of down syndrome (DS) patients, whereas brain is a highly complex and nonlinear system. In this study, fractal dimension of EEG, as a key characteristic of brain dynamics, showing irregularity and complexity of brain dynamics, was used for evaluation of the dynamical changes in the DS brain. The results showed higher fractality of the DS brain in almost all regions compared to the normal brain, which indicates less centrality and higher irregular or random functioning of the DS brain regions. Also, laterality analysis of the frontal lobe showed that the normal brain had a right frontal laterality of complexity whereas the DS brain had an inverse pattern (left frontal laterality). Furthermore, the high accuracy of 95.8 % obtained by enhanced probabilistic neural network classifier showed the potential of nonlinear dynamic analysis of the brain for diagnosis of DS patients. Moreover, the results showed that the higher EEG fractality in DS is associated with the higher fractality in the low frequencies (delta and theta), in broad regions of the brain, and the high frequencies (beta and gamma), majorly in the frontal regions.     

Pedometer-determined physical activity levels of healthy children and children with Down’s syndrome

Purpose: Children with Down’s syndrome (DS) are considered sedentary and less engaged in recommended physical activity (PA) levels. This study compared the PA levels between children with DS and healthy children in Saudi Arabia.

Methods: The study included 85 children divided into two groups. The DS group comprised 37 children with DS aged 8–12?years recruited from the Down Syndrome Charitable Association and Al-Nahda Schools for DS. The healthy group comprised 41 healthy children aged 8–12?years recruited from regular schools in the same region. PA levels were measured over 7?days using a pedometer.

Results: The healthy group was more active than the DS group (p?p?p?Conclusions: The DS group had a high body mass index and physical inactivity compared with the second group. Obesity and physical inactivity among Saudi Arabian children with and without DS are major health concerns. Therefore, concerted efforts are needed to combat childhood obesity, promote PA, improve patient quality of life, and reduce the sedentary lifestyle among Saudi children and adolescents.     

TNF-α -308 genotypes are associated with TNF-α and TGF-β₁ mRNA expression in blood leucocytes of humans

AimTumor necrosis factor α (TNF-α) influences the pathogenesis of lung-fibrosis and carcinogenesis in normal cells. Polymorphisms of this gene are suggested to be associated with susceptibility to lung-diseases. Additionally TNF-α is postulated to play a significant role in regulating. Transforming growth factor (TGF-β₁) expression Therefore we investigated if the TNF-α or TGF-β₁ gene expression level is different within the ?308 TNF-α genotypes.MethodsQuantitative Real-time PCR of TNF-α and TGF-β₁ was performed in 178 Germans. Calculations of expression were made with the 2^?ΔΔCT method. Detection of the ?308 promoter polymorphism of the TNF-α gene was performed by rapid capillary PCR with melting curve analysis.ResultsThe relative TNF-α mRNA expression revealed significant differences between the TNF-α ?308 homozygote wild-type G/G (0.00079 ± 0.00011; n = 113) and the heterozygote genotype G/A (0.0005 ± 0.00008; n = 52; p = 0.030) as well as between homozygote wild-type G/G and the homozygote mutant A/A (0.00029 ± 0.00009; n = 5; p = 0.004). The relative TGF-β mRNA expression showed, similar to TNF-α, the highest mRNA expression was seen within the TNF-α ?308 homozygote wild-types, while the lowest mRNA expression lay within the homozygote mutant-types.ConclusionOur findings suggest that the G-allele of TNF-α ?308 is associated with a significantly higher TNF-α mRNA expression compared to the A-allele and that this also reflects in TGF-β expression. Therefore we support the thesis that TGF-β is regulated by TNF-α.     

Differential diagnostic performance of Rose Bengal Score Test in Sjøgren's syndrome patients

Aim of the study was to evaluate the diagnostic performance of the Rose Bengal score test for Sj?gren's syndrome (SS), and to explore differences between other tests and examinations. All participants were examined, including (but not limited to) unstimulated (UWS) and stimulated (SWS) whole saliva, labial gland biopsy (LGB or focus score), ophthalmologic questionnaire (ocular surface disease index OSDI) and objective tests: Schirmer test 1 (Sch. 1), Schirmer test 2 (Sch.2), Tear Break-up Time (TBUT) test and Rose Bengal score (RBS). Data were analyzed using Mann Whitney U-test, Receiver Operating Characteristic analysis, with specificity and sensitivity calculations and Spearman's correlation test. ROC curves showed a poor diagnostic performance of TBUT and OSDI. Sch. 1, Sch.2 and LGB all exhibited a high diagnostic performance. RBS exhibited the best performance (sensitivity 100,00; specificity 100,00; AUC 1,000). Study reveals the scarce reliability of TBUT, OSDI and Sch.1, and emphasizes RBS as the test of choice in the SS diagnosis.     

Application of trace metal analysis to basic problems in neurobiology studies of patients with Reye’s syndrome

Reye’s syndrome (Rs) is an acute illness in children manifested by encephalopathy and fatty degeneration of the liver. The syndrome may be secondary to injury of mitochondria following a toxic insult in a susceptible individual with a viral illness. Since the response to infection often involves a change in trace metals, we investigated the metal status of patients with Rs. Decreased levels of serum and liver selenium (Se) and copper (Cu) were demonstrated via PIXE analysis, in addition to an increase in serum iron (Fe) and zinc (Zn). In a subsequent study using a rat animal model of Rs, the hepatotoxin 4-pentenoic acid (4-PA) produced similar changes in serum and liver trace metals. Serum and liver Se levels were also significantly depleted in rats exposed to another toxin, valproic acid (VPA). Aspirin, known to complex metals, may also be associated with Rs. Rats chronically exposed to aspirin had decreased serum Se, Fe, and Zn compared to controls. Selenium was also decreased in liver, as was Cu. Atomic absorption spectrophotometric analysis of serum and liver Cu for mice exposed to aspirin and influenza A virus were also studied. In liver, Cu was significantly decreased in mice on Cu-deficient diets but, not in control mice exposed to virus, or aspirin and virus. For the Se-deficient animals, liver Cu was not different from controls, but there was an increase in tissue Cu for Se-sufficient mice exposed to virus and aspirin; Cu levels were decreased in sera of this latter group. Serum Cu was increased in Cu-sufficient mice exposed to virus and aspirin. The above data are of biologic and toxicologic interest because of metalloenzyme localization in the mitochondrial matrix, the cellular compartment showing the greatest degree of pathologic change in Rs. In particular, Se-dependent gluthathione peroxidase is a major deterent of peroxidative damage of lipid membranes. The accumulated evidence suggests that alteration of trace metals, e.g., decrease in Se, may promote peroxidation of mitochondrial membranes in patients with Rs.     

Differential Association of Phosphodiesterase 4D Isoforms with ��2-Adrenoceptor in Cardiac Myocytes

cAMP and protein kinase A (PKA) activation represents a key signaling mechanism upon β-adrenergic stimulation under stress. Both β₁- and β₂-adrenoreceptor (ARs) subtypes induce cAMP accumulation, yet play distinct roles in cardiac contraction and myocyte apoptosis. Differences in controlling cAMP/PKA activities through the assembly of complexes between the receptors and cAMP-specific phosphodiesterases contribute to the distinct biological outcomes. Here, we demonstrate that β₂ARs form signaling complexes with a set of PDE4D isoforms expressed in cardiac myocytes. PDE4D9 and PDE4D8 bind to the β₂AR at resting conditions; however, agonist stimulation induces dissociation of PDE4D9 from the receptor but recruitment of PDE4D8 to the receptor. Agonist stimulation also induces recruitment of PDE4D5 to the β₂AR. Moreover, the receptor-associated PDE4D isoforms play distinct roles in controlling cAMP activities and regulating the PKA phosphorylation of the receptor and myocyte contraction rate responses. Knockdown of PDE4D9 with short hairpin RNA enhances the β₂AR-induced cAMP signaling, whereas knockdown of PDE4D8 only slightly prolongs the receptor-induced cAMP signaling in myocytes. Inhibition of PDE4D9 and PDE4D5 enhances the base-line levels of contraction rates, whereas inhibition of PDE4D9 and PDE4D8 enhances the maximal contraction rate increases upon activation of β₂AR. Our data underscore the complex regulation of intracellular cAMP by β₂AR-associated phosphodiesterase enzymes to enforce the specificity of the receptor signaling for physiological responses.     

Presence of immunoreactive β-endorphin in plasma of patients with Nelson's syndrome and Addison's disease

A sensitive radioimmunoassay for β-endorphin (β-EP) has been developed with an antiserum obtained from a guinea pig immunized with β-EP which was contained in crude porcine ACTH preparations (Organon). The minimal detectable quantity of β-EP was 1 pg. This antibody has the same affinity for β-EP and β-LPH on a molar basis, but human ACTH, α-MSH, β-MSH, α-EP, γ-EP, Met⁵-Enkephalin and Leu⁵-Enkephalin failed to displace ¹²⁵I-β-EP from its antibody. Utilizing this radioimmunoassay we have demonstrated the existence of β-EP in plasma from patients with Nelson's syndrome and Addison's disease.     

Antineural antibody in patients with Tourette’s syndrome and their family members

Summary It has been proposed that antineural antibodies were present in patients with Tourette’s syndrome (TS) and other neuropsychiatric disorders. The purpose of our study was to investigate the presence of antineural antibodies in the individuals with Tourette’s syndrome and the family members of TS patients. The sera of four TS patients with no current streptococcal infection, their tic-free family members including father, mother and sibling, and a age-matched control group who were tic free were assayed for antineural antibodies directed against rat tissue and neurons in primary cell culture. There were prominent antineural antibodies present in TS patients and their first-degree family members, but not in the control group. Western blotting showed proteins of about 120 kDa in their sera that were not present in the sera of controls. The preliminary results of our study suggest the importance of genetic vulnerability in the immunological pathophysiology of tic disorders. Future studies should investigate the interactions of genetics, environment, infectious agents, and immunity on symptom expression in families with tic disorders. This study was supported in part by the C.Y. Foundation for the Advancement of Education, Science and Medicine, and National Health Research Institutes (NHRI-EX94-9008SC), Taipei, Taiwan.     

A 32-year-old woman with Down’s syndrome and central cyanosis

A 32-year-old woman was referred to our hospital because of a progressive decline in her physical condition. Her medical history revealed a congenital heart defect and Down’s syndrome.     

Analysis of helicase gene mutations in Japanese Werner’s syndrome patients

The profile of helicase gene mutations was studied in 89 Japanese Werner’s syndrome (WRN) patients by examining the previously described mutations 1– 4 as well as a new mutation found during this study, designated mutation 5. Of 178 chromosomes (89 patients), 89 chromosomes (50%) had mutation 4, 11 (6.2%) chromosomes had mutation 1, and two chromosomes (1.1%) contained mutation 5. Mutations 2 and 3 were not observed in this patient population. The remaining 76 (42.7%) chromosomes had none of these mutations. A significant fraction of all patients (22 total patients, 24.7%) appear to be compound heterozygotes, including those carrying mutations of both types 1 and 4. The genotype analysis of the markers surrounding the WRN helicase gene strongly suggests that most of the chromosomes carrying either mutation 1 or 4 were derived from two single founders. Received: 25 July 1996 / Revised: 20 September 1996