DNA hypermethylation of the alpha synuclein promoter in patients with alcoholism

The aim of this study was to investigate whether the DNA methylation pattern within the alpha synuclein promoter region is altered in intoxicated and early abstinence patients with alcoholism undergoing alcohol withdrawal. We observed a significant increase of the alpha synuclein promoter DNA methylation in patients with alcoholism which was significantly associated with their elevated homocysteine levels. No significant differences of the promoter DNA methylation within a control gene (presenilin-1) in alcoholics and controls were found. The present results hint to a gene specific DNA promoter hypermethylation within the alpha synuclein gene. Since hypermethylation of DNA is an important epigenetic factor in the down regulation of gene expression and since alpha synuclein has been linked to craving these findings may explain the reduced value of craving under alcohol drinking conditions.

C677T variant in the methylentetrahydrofolate reductase gene is a genetic risk factor for primary open-angle glaucoma

PURPOSE

To estimate the prevalence of C677T single nucleotide polymorphism in the 5,10-methylentetrahydrofolate reductase (MTHFR) gene in primary open-angle glaucoma (POAG) and pseudoexfoliation open-angle glaucoma (PEXG).

DESIGN

Case-control study

METHODS

MTHFR was assessed in 147 patients (76 POAG, 71 PEXG) and 71 control subjects with cataract. Associations of genotypes were assessed by Armitage's trend test and the corresponding odds ratio (OR) for allele positivity with 95% confidence interval (CI).

RESULTS

We observed significant evidence of a higher prevalence of C677T in POAG (9% homozygote, 49% heterozygote, 42% wildtype, P = .01, OR = 2.38, 95% CI 1.23-4.62), but not in PEXG (9% homozygote, 41% heterozygote, 50% wildtype, P = .09, OR = 1.78, 95% CI 0.91-3.50) compared with the controls (3% homozygote, 34% heterozygote, 63% wildtype).

CONCLUSIONS

The MTHFR C677T variant leading to moderate hyperhomocysteinemia may play a role in the pathogenesis of POAG acting as a genetic risk factor.

Homocysteine associated genomic DNA hypermethylation in patients with chronic alcoholism

Higher plasma homocysteine concentrations can influence genomic DNA methylation in peripheral blood cells. In the present controlled study we observed a significant increase (10%) of genomic DNA methylation in patients with alcoholism (t = -3.16, df = 158, p = 0.002) which was significantly associated with their elevated homocysteine levels (multiple linear regression, p < 0.001). Since methylation of DNA is an important epigenetic factor in regulation of gene expression these findings may have important implications for a possible subsequent derangement of epigenetic control these patients.

Joint analysis of the NACP-REP1 marker within the alpha synuclein gene concludes association with alcohol dependence

Various studies have linked alcohol dependence phenotypes to chromosome 4. One candidate gene is NACP (non-amyloid component of plaques), coding for alpha synuclein. Recently, it has been shown that alpha synuclein mRNA is increased in alcohol-dependent patients within withdrawal state. This increase is significantly associated with craving, especially obsessive craving. On the basis of these observations, the present study analysed two polymorphic repeats within the NACP gene. We found highly significant longer alleles of NACP-REP1 in alcohol-dependent patients compared with healthy controls (Kruskal-Wallis test, chi(2)=99.5; df=3, P<0.001). In addition, these lengths significantly correlate with levels of expressed alpha synuclein mRNA (chi(2)=8.83; df=2, P=0.012). The present results point to a novel approach for a genetic determination of craving, a key factor in the genesis and maintenance not only of alcoholism but also of addiction in general.

Creutzfeldt-Jakob Disease and Homocysteine Levels in Plasma and Cerebrospinal Fluid

BACKGROUND

There is evidence that homocysteine contributes to various neurodegenerative disorders.

OBJECTIVE

To assess the values of homocysteine in patients with Creutzfeldt-Jakob disease (CJD) in both cerebrospinal fluid (CSF) and plasma.

METHODS

STUDY DESIGN

Case control study. Total homocysteine was quantified in CSF and plasma samples of CJD patients (n=13) and healthy controls (n=13).

RESULTS

Mean values in healthy controls: 0.15 micromol/l +/- 0.07 (CSF) and 9.10 micromol/l +/- 2.99 (plasma); mean values in CJD patients: 0.13 micromol/l +/- 0.03 (CSF) and 9.22 micromol/l +/- 1.81 (plasma). No significant differences between CJD patients and controls were observed (Mann-Whitney U, p >0.05).

CONCLUSIONS

The results indicate that the CSF and plasma of CJD patients showed no higher endogenous levels of homocysteine as compared to normal healthy controls. These findings provide no evidence for an additional role of homocysteine in the pathogenetic mechanisms underlying CJD neurodegeneration.

Olfactory deficits in anorexia nervosa

OBJECTIVE

Young patients admitted to the hospital due to anorexia nervosa report reduced pleasure and impaired perception of smell while eating. So far, two studies on odour identification ability in eating disorders did not suggest any significant deficits. Therefore a new and more detailed method of olfactory testing may be needed, in order to determine the subjective impairment of olfaction.

METHOD

By using all three subtests of the recently developed smell test called "Sniffin'Sticks", the olfactory deficits were assessed in more detail and the results of female anorectic patients (n = 17) were compared with those of healthy females (n = 15).

RESULTS

By examining the anorectic patients no deficits in the subtest odour identification were found. On the contrary, in the subtests odour discrimination and odour threshold deficits of the anorectic patients were detected.

CONCLUSION

Reduced olfactory perception might be considered as a common deficit in anorexia nervosa with possible influences and consequences for therapy.

Elevated alpha synuclein mRNA levels are associated with craving in patients with alcoholism

BACKGROUND

Alpha synuclein has been found elevated in dopamine neurons of cocaine abusers and in rats whose alcohol preference is inbred.

METHODS

The alpha synuclein mRNA expression level was measured by quantitative polymerase chain reaction in the blood of 75 male alcoholics and 69 nondrinking healthy control subjects. Alcohol craving was assessed by the Obsessive-Compulsive Drinking Scale total score, including subscales for obsessive and compulsive craving.

RESULTS

The alpha synuclein expression in patients with alcoholism (2.79 DeltaCT; SD = 1.69; p = .021) was significantly higher when compared with healthy control subjects (2.20 DeltaCT; SD = 1.59). Increased alpha synuclein levels significantly predict Obsessive-Compulsive Drinking Scale total score (odds ratio = 1.44, 95% confidence interval: 1.01-2.06, p = .042) and especially Obsessive-Compulsive Drinking Scale obsessive subscale (odds ratio = 1.74, 95% confidence interval: 1.18-2.58, p = .005) but not Obsessive-Compulsive Drinking Scale compulsive subscale alcohol craving.

CONCLUSIONS

Higher levels of alpha synuclein are associated with an increase in alcohol craving. The present results provide a novel pathophysiological approach to the explanation of craving mechanisms.

The Etiopathogenesis of Schizophrenias

There is no generally accepted model explaining the aetiopathogenesis of schizophrenias. In recent years, hypotheses with a focus on single aspects of neurotransmission, single major genetic loci or single brain areas were predominating. Now, these different approaches converge to systemic models including neurotransmission, genetic changes and neurodevelopmental malformation of brain structures. Such systemic models will explain more aspects of schizophrenias than the recent confined hypotheses.

Plasma homocysteine concentrations do not influence craving in alcohol withdrawal

Results of a number of studies indicate that the glutamate system, especially the N-methyl-D-aspartate (NMDA) receptor, has a major function in chronic alcoholism, including craving. Homocysteine and other excitatory amino acids, such as glutamate and aspartate, lead to an overstimulation of NMDA receptors. Because alcoholism is associated with elevated plasma homocysteine concentrations, we designed the current study to determine whether elevated plasma homocysteine concentrations have an influence on craving in alcohol withdrawal. Two groups of patients with an established diagnosis of alcohol dependence were compared. Group A comprised 50 consecutively admitted alcohol-dependent individuals who had been abstinent from alcohol between 24 and 72 h before hospitalization. Group B comprised 146 consecutively recruited alcohol-dependent individuals who were admitted, acutely intoxicated, for withdrawal treatment. All patients were assessed with the Obsessive Compulsive Drinking Scale (OCDS) on the day of admission and after 7 days of treatment. The mean (27.1, S.D. 18.4) plasma homocysteine concentration for group B was significantly higher than the mean (12.5, S.D. 5.3) plasma homocysteine concentration for group A (Mann-Whitney U test: P < .001). No significant influence of homocysteine concentration on the extent of craving was found for either group with the use of the Spearman correlation (day 0: group A, r = -.076, P = .601; group B, r = .120, P = .148) and logistic regression analysis. Although homocysteine is a potent modulator of glutamatergic neurotransmission, results of the current study provide no evidence for a pathophysiologic role of homocysteine in withdrawal craving. Therefore, further research about alcohol craving should focus on neurobiologic factors other than homocysteine.

HOMOCYSTEINE LEVELS IN PATIENTS CLASSIFIED ACCORDING TO LESCH'S TYPOLOGY

AIMS

It has been suggested that elevated total plasma homocysteine levels might be useful to predict alcohol withdrawal seizures. The typology by Lesch distinguishes between four subtypes of which type 1 suffers from marked withdrawal symptoms, including alcohol withdrawal seizures. This study was undertaken to investigate total plasma homocysteine levels in actively drinking patients with alcoholism who were classified according to Lesch's typology.

SUBJECTS AND METHODS

We determined total plasma homocysteine levels in 144 non-abstinent chronic alcoholics (115 men, 29 women; aged 22-67 years). Patients were classified in Lesch's typology (LT) and were divided into two groups: LT 1 (n = 27) and LT 2-4 (n = 117). Within the groups, patients with or without a history of alcohol withdrawal seizures were differentiated.

RESULTS

All patients with a history of alcohol withdrawal seizures had significantly elevated plasma homocysteine concentrations at admission when compared with those without seizures (Mann-Whitney U, P < 0.001). Furthermore, patients classified as LT 1 who suffered from an alcohol withdrawal seizure (n = 12) had significantly higher plasma homocysteine levels (Z = -2.31, P = 0.02) when compared to the corresponding types 2-4 (n = 24). Using a logistic regression analysis, withdrawal seizures were best predicted by a high homocysteine level at admission but even more pronounced in LT 1 (Wald's chi-squared [chi(2)] = 10.7; odds ratio [OR] 1.24; 95% confidence interval [CI] 1.03-1.51; P < 0.001) when compared with LT 2-4 (chi(2) = 10.6; OR 1.06; 95%CI 1.03-1.14; P = 0.004).

CONCLUSION

To our knowledge, this is the first study evaluating homocysteine levels in patients who were classified according to Lesch's typology. Homocysteine levels on admission may be a useful screening method to identify actively drinking patients at risk of alcohol withdrawal seizures, especially in alcoholics with Lesch type 1.

Leptin is associated with craving in females with alcoholism

The appetite and weight regulating peptide leptin was associated recently with alcohol craving during withdrawal. Nevertheless, correlations were only significant with craving displayed on the visual analogue scale for maximum craving during the previous week (VAS), and not if assessed with the highly validated Obsessive Compulsive Drinking Scale (OCDS). The objective of the following study, therefore, is to elucidate further the associations between the leptin system and craving concepts during alcohol withdrawal. A sufficiently large sample size should allow multiple statistical subgroup and confounder analyses. We prospectively investigated 102 chronic alcoholic inpatients (23 females, 79 males) during withdrawal on days 0 (admission), 1, 2 and days 7-10. In addition to the statistical analysis of the total sample, females and males were to be analysed separately. For detecting associations between leptin levels and craving scores multiple regression analysis was performed. Plasma leptin levels were determined, and craving for ethanol was assessed by both the OCDS and the VAS. Leptin plasma levels significantly increased during alcohol withdrawal compared to day 0, while all craving scores decreased. Body mass corrected leptin plasma levels predicted craving on day 0 in the OCDS total score (R=0.55, F=7.91, df=1.19, p<0.05) and in the OCDS obsessive subscore (R=0.57, F>=8.48, df=1.19, p<0.05) in females. Neither in males nor in the total population did multiple regression analysis reveal any significant results. Leptin levels seem to change during inpatient alcohol withdrawal. In a multivariate model, correlations between leptin levels and the highly validated craving scores of the OCDS can only be assumed in females. Hence, gender differences have to be taken into account when searching for neurobiological models of alcohol craving.

Elevated homocysteine levels in aqueous humor of patients with pseudoexfoliation glaucoma

PURPOSE

To determine total homocysteine levels in aqueous humor of pseudoexfoliation open-angle glaucoma patients.

DESIGN

Case-control study.

METHODS

Total homocysteine levels were measured by enzyme-linked immunosorbent assay in aqueous humor and plasma of 29 patients with pseudoexfoliation glaucoma and 31 control patients with cataract. Patients with factors affecting homocysteine levels were excluded.

RESULTS

We observed significantly elevated (twofold) homocysteine levels in the aqueous humor of the glaucoma patients (Z = -5.11, P <.0001). Additionally, the calculated ratio (plasma:aqueous humor) was significantly lower in these patients (Z = -3.57, P <.001), and aqueous homocysteine was significantly correlated with their respective elevated plasma levels (r =.42, P =.02).

CONCLUSIONS

Because homocysteine induces vascular injury and alterations of extracellular matrix, high aqueous homocysteine may trigger the abnormal matrix accumulation characteristic. It may reflect the proposed impairment of the blood-aqueous barrier of pseudoexfoliation open-angle glaucoma and be involved in its pathogenesis.

Analysis of hippocampal atrophy in alcoholic patients by a Kohonen feature map

We investigated the correlation of hippocampal volume with homocysteine, folate, vitamin B12 and B6 in alcoholic patients and healthy controls applying a Kohonen feature map (KFM) and conventional statistics. Representation of subjects on the KFM suggested an inverse correlation of hippocampal volume with blood levels of homocysteine and correlation with folate and vitamin B6. In conventional statistical analyses (t-test) reduced folate and increased homocysteine was found in alcoholics compared to healthy controls (p < 0.01). In female alcoholics vitamin B6 was reduced significantly (p = 0.03). Multiple linear regression analyses showed a significant correlation between average hippocampal volume and homocysteine (p < 0.001). KFM proved to be a sensitive tool for visualisation of statistical correlations in data sets even if no further statistical information is available.

CPAP-therapy effectively lowers serum homocysteine in obstructive sleep apnea syndrome

Assessment of serum total homocysteine (tHcy) in patients with obstructive sleep apnea (OSA) syndrome is highly relevant since both are strongly associated with stroke and cognitive dysfunction. Seven of 16 untreated OSA patients showed tHcy levels exceeding 11.7 micromol/l. The circadian pattern of serum tHcy in untreated and treated patients (p < 0.001) implied a diagnostic impact of blood sampling time. Treatment with continuous positive airway pressure (CPAP) effectively lowered tHcy levels in patients by about 30% (p < 0.005) and thus probably the (hyper)homocysteinemia-related cognitive dysfunction and the risk for cardio-/cerebrovascular diseases.

Fols�ure gegen Hyperhomocystein�mie

There is growing evidence that chronic alcoholism is associated with a derangement in the sulfur amino acid metabolism. Excitatory aminoacids such as glutamate, aspartate, and homocysteine have been shown to be increased in patients with chronic alcoholism who underwent alcohol withdrawal. Furthermore, sustained hyperhomocysteinemia occurred in chronic alcoholics with active drinking pattern. Excitotoxicity can be induced by increased hormocysteine levels via rebound activation of NMDA receptor-mediated glutamatergic neurotransmission upon the removal of ethanol-evoked inhibition. Therefore, hyperhomocysteinemia may be responsible for the higher incidence of complications during alcohol withdrawal (e.g.stroke,convulsions). In addition, an association between brain atrophy and increased levels of homocysteine in chronic alcoholism was shown. This may have important implications for the pathogenesis of brain atrophy in alcoholics. Taking into account that high plasma homocysteine levels are helpful in the prediction of alcohol withdrawal seizures, early anti-convulsive therapy could prevent this severe complication. Supplementation of folate, a cofactor of the homocysteine metabolism, lowers raised homocysteine levels and therefore could be established as a new therapeutic strategy in alcohol withdrawal treatment. The results of various studies highlight the need for further research to prove whether alcoholics benefit from a reduced homocysteine level with respect to both, alcohol-related disorders and alcohol withdrawal symptoms.

Homocysteine as a neurotoxin in chronic alcoholism

There is evidence from in vitro and in vivo studies that homocysteine induces neuronal damage and cell loss by both excitotoxicity and different apoptotic processes. Clinical evidence suggest a strong relationship between higher plasma homocysteine levels and brain atrophy in healthy elderly subjects as well as in elderly at risk of and with Alzheimer's disease. Chronic alcoholism leads to elevated plasma homocysteine levels, as shown by clinical investigations and animal experiments. In addition, an association between brain atrophy and increased levels of homocysteine in chronic alcoholism was shown. This may have important implications for the pathogenesis of alcoholism-associated brain atrophy. Furthermore, taking into account that high plasma homocysteine levels are helpful in the prediction of alcohol withdrawal seizures, early anticonvulsive therapy could prevent this severe complication. Homocysteine plays a role in a shared biochemical cascade involving overstimulation of N-methyl-D-aspartate (NMDA) receptors, oxidative stress, activation of caspases, DNA damage, endoplasmic reticulum and mitochondrial dysfunction. These mechanisms are believed to be important in the pathogenesis of both excitotoxicity and apoptotic neurotoxicity. Prospective intervention studies may show whether the incidence of complications of alcohol withdrawal or alcoholism-associated disorders can be reduced by therapeutic measures with early lowering of elevated homocysteine levels (e.g. folate administration). The most important pathophysiological and pathobiochemical features of glutamatergic neurotransmission and of ethanol-induced hyperhomocysteinaemia are reviewed in relation to their excitotoxic and apoptotic potential.