CFTR genotype-related body water and electrolyte balance during a marathon

The aim of this investigation was to determine the influence of CFTR genotype on body water and electrolyte balance during a marathon. Fifty-one experienced runners completed a marathon race. Before and after the race, body mass and a sample of venous blood were obtained. During the race, sweat samples were collected using sweat patches, and fluid and electrolyte intake were obtained using self-reported questionnaires. Thirty-eight participants (74.5% of the total) were 7T/7T homozygotes, 11 (21.6%) were 7T/9T heterozygotes, and one participant presented the rare genotype 5T/7T. Another participant with 9T/9T presented the mutation p.L206W. Participants with 7T/7T showed higher sweat sodium concentrations (42.2 ± 21.6 mmol/L) than 7T/9T (29.0 ± 24.7 mmol/L; P = 0.04). The runner with the 5T/7T genotype (10.2 mmol/L) and the participant with the p.L206W mutation (20.5 mmol/L) exhibited low-range sweat sodium concentrations. However, post-race serum sodium concentration was similar in 7T/7T and 7T/9T (142.1 ± 1.3 and 142.4 ± 1.6 mmol/L, respectively; P = 0.27) and did not show abnormalities in participants with the 5T/7T genotype (140.0 mmol/L) and the p.L206W mutation (143.0 mmol/L). Runners with the CFTR-7T/7T genotype exhibited increased sweat sodium concentrations during a marathon. However, this phenotype was not related with increased likelihood of suffering body water and electrolyte imbalances during real competitions.

Oxidative stress mediated mitochondrial and vascular lesions as markers in the pathogenesis of Alzheimer disease

Mitochondrial dysfunction plausibly underlies the aging-associated brain degeneration. Mitochondria play a pivotal role in cellular bioenergetics and cell-survival. Oxidative stress consequent to chronic hypoperfusion induces mitochondrial damage, which is implicated as the primary cause of cerebrovascular accidents (CVA) mediated Alzheimer's disease (AD). The mitochondrial function deteriorates with aging, and the mitochondrial damage correlates with increased intracellular production of oxidants and pro-oxidants. The prolonged oxidative stress and the resultant hypoperfusion in the brain tissues stimulate the expression of nitric oxide synthase (NOS) enzymes, which further drives the formation of reactive oxygen species (ROS) and reactive nitrogen species (RNS). The ROS and RNS collectively contributes to the dysfunction of the blood-brain barrier (BBB) and damage to the brain parenchymal cells. Delineating the molecular mechanisms of these processes may provide clues for the novel therapeutic targets for CVA and AD patients.

Combination treatment in Alzheimer's disease: results of a randomized, controlled trial with cerebrolysin and donepezil

Treatment with neurotrophic agents might enhance and/or prolong the effects of cholinesterase inhibitors (ChEIs) in Alzheimer's disease (AD). We compared the safety and efficacy of the neurotrophic compound Cerebrolysin (10 ml; n=64), donepezil (10 mg; n=66) and a combination of both treatments (n=67) in mild-to-moderate (mini-mental state examination-MMSE score 12-25) probable AD patients enrolled in a randomized, double-blind trial. Primary endpoints were global outcome (Clinician's Interview-Based Impression of Change plus caregiver input; CIBIC+) and cognition (change from baseline in AD Assessment Scale-cognitive subscale+; ADAS-cog+) at week 28. Changes in functioning (AD Cooperative Study-Activities of Daily Living scale, ADCS-ADL) and behaviour (Neuropsychiatric Inventory, NPI) were secondary endpoints. Treatment effects in cognitive, functional and behavioral domains showed no significant group differences; whereas improvements in global outcome favored Cerebrolysin and the combination therapy. Cognitive performance improved in all treatment groups (mean±SD for Cerebrolysin: -1.7±7.5; donepezil: -1.2±6.1; combination: -2.3±6.0) with best scores in the combined therapy group at all study visits. Cerebrolysin was as effective as donepezil, and the combination of neurotrophic (Cerebrolysin) and cholinergic (donepezil) treatment was safe in mild-to-moderate AD. The convenience of exploring long-term synergistic effects of this combined therapy is suggested.

Efficacy and safety of Cerebrolysin in moderate to moderately severe Alzheimer's disease: results of a randomized, double-blind, controlled trial investigating three dosages of Cerebrolysin

BACKGROUND

cerebrolysin is a neuropeptide preparation mimicking the effects of neurotrophic factors. This subgroup analysis assessed safety and efficacy of Cerebrolysin in patients with moderate to moderately severe Alzheimer's disease (AD) (ITT data set: N = 133; MMSE: 14-20) included in a dose-finding study (ITT data set: N = 51; MMSE: 14-25). Results of the mild AD subgroup (ITT data set: N = 118; MMSE: 21-25) are also presented.

METHODS

patients with AD received 100 ml IV infusions of Cerebrolysin (10, 30 or 60 ml diluted in saline; N = 32, 34 and 35, respectively) or placebo (saline; N = 32) over twelve weeks (5 days per week for 4 weeks and 2 days per week for another 8 weeks). Primary efficacy criteria ADAS-cog+ (Alzheimer's Disease Assessment Scale Cognitive Subpart Modified) and CIBIC+ (Clinical Interview-based Impression of Change with Caregiver Input) were assessed 24 weeks after baseline.

RESULTS

at week 24, Cerebrolysin improved the global clinical function significantly with all three dosages and induced significant improvements in cognition, initiation of activities of daily living (ADL) and neuropsychiatric symptoms at 10-, 30- and 60-ml doses, respectively. Treatment effects on total ADL and other secondary parameters (MMSE, Trail-making test) were not significant. Cerebrolysin was safe and well tolerated.

CONCLUSIONS

these results demonstrate the efficacy of Cerebrolysin in moderate to moderately severe AD, showing dose-specific effects similar to those reported for patients with mild to moderate AD. The benefits of Cerebrolysin in advanced AD need to be confirmed in larger trials.

A 24-week, double-blind, placebo-controlled study of three dosages of Cerebrolysin in patients with mild to moderate Alzheimer's disease

Cerebrolysin (Cere) is a compound with neurotrophic activity shown to be effective in Alzheimer's disease in earlier trials. The efficacy and safety of three dosages of Cere were investigated in this randomized, double-blind, placebo-controlled, study. Two hundred and seventy-nine patients were enrolled (69 Cere 10 ml; 70 Cere 30 ml; 71 Cere 60 ml and 69 placebo). Patients received iv infusions of 10, 30, 60 ml Cere or placebo 5 days/week for the first 4 weeks and thereafter, two iv infusions per week for 8 weeks. Effects on cognition and clinical global impressions were evaluated 4, 12 and 24 weeks after the beginning of the infusions using the CIBIC+ and the modified Alzheimer's Disease Assessment Scale (ADAS)-cog. At week 24, significant improvement of cognitive performance on the ADAS-cog (P=0.038) and global function (CIBIC+; P>0.001) was observed for the 10 ml dose. The 30 and 60 ml doses showed significant improvement of the global outcome but failed to show significant improvement of cognition. The results are consistent with a reversed U-shaped dose-response relationship for Cere. The percentage of patients reporting adverse events was similar across all study groups. Cere treatment was well tolerated and led to significant, dose-dependent improvement of cognition and global clinical impression.

Neuropeptide dietary supplement N-PEP-12 enhances cognitive function and activates brain bioelectrical activity in healthy elderly subjects

N-PEP-12 is a dietary supplement consisting of neuropeptides and amino acids. In animal experiments, the compound has been shown to enhance cognitive function and reduce neurodegenerative events associated with aging. In this study, we investigated the effects of a single oral dose of N-PEP-12 (180 mg) on brain bioelectrical activity and cognitive performance in healthy elderly subjects. N-PEP-12 induced a significant (p < 0.05) increase in relative alpha-activity power 6 h after administration. This enhancement was accompanied by a generalized decrease in slow Delta-activity. Significant improvement in memory performance subtests was also seen 6 h after N-PEP-12 administration in some but not in all tests. Taken together, these data suggest that N-PEP-12 might be a reliable dietary supplement to be investigated for improving and, perhaps, maintaining brain function among healthy older adults.

Polymorphic variants of the beta2-adrenergic receptor (ADRB2) gene and ADRB2-related propanolol-induced dyslipidemia in the Colombian population

Different polymorphisms of the ADRB2 gene encoding the beta-adrenergic receptor (ADRB2) are associated with changes in a variety of responses of the sympathetic nervous system (SNS). In this study, we have investigated the distribution of frequencies of ADRB2-related allelic variants (Arg16Gly, Gln27Glu, Thr164Ile) in the Colombian population, as well as the influence of the Gln27Glu polymorphism as a risk factor for the development of dyslipidemia following propranolol administration. Genotyping was performed in unrelated Colombian volunteers, using PCR-RFLP methods. To examine the association between the Gln27Glu polymorphism of the ADRB2 gene and dyslipidemia induced by propranolol, we recruited 19 healthy individuals who were homozygous for either the Gln27 (wild-type, N = 11) or the Glu27 (homozygous mutant, N = 8) genotype. Electrocardiography (ECG), heart rate (HR), systolic blood pressure (SBP), diastolic blood pressure (DBP), body mass index (BMI), serum lipid levels (T-CHO, HDL-CHO, TG), and fibrinogen were determined before and after propranolol administration. The distribution of genotypes was as follows: Arg16Arg 46%, Arg16Gly 47.4%, Gly16Gly 6.6%, Gln27Gln 44.7%, Gln27Glu 48.2%, and Glu27Glu 7.1%, with allelic frequencies of 69.7% for Arg16, 30.3% for Gly16, 68.8% for Gln27, and 31.2% for Glu27. The Thr164Ile polymorphism was found only in one subject, who was heterozygous for the isoleucine variant. Significant changes in physiological parameters (HR, SBP, DBP) have been found in association with ADRB2 variants in both native and mutant subgroups after propranolol intake. HDL-CHO levels diminished (p = 0.005) in native homozygous individuals (Gln27Gln), whereas TG levels were found increased (p = 0.012) in the mutant homozygous individuals (Glu27Glu). T-CHO levels and serum fibrinogen levels remained unaltered in both subgroups. The evidence that subjects homozygous for Gln27 in the ADRB2 gene show a significant reduction of HDL-CHO levels, as well as the increased TG levels in subjects homozygous for Glu27 after propranolol administration, suggest that the Gln27Glu polymorphism represents a risk factor for dyslipidemia induced by propranolol. These results may contribute to a better understanding of the mechanisms underlying dyslipidemia induced by ADRB2 antagonists.

Effects of fish-derived lipoprotein extracts on activation markers, Fas expression and apoptosis in peripheral blood lymphocytes

Several factors may influence numbers and function of peripheral blood lymphocytes (PBLs) by different processes. We conducted this study to evaluate the effect of E-CAB-94011 and E-JUR-94013, two marine fish extracts from S. scombrus and T. trachurus, respectively, on in vitro PBLs activation and on the expression and functionality of Fas, a cell surface molecule that plays a central role in immune homeostasis and cytotoxic activity. PBLs from 24 healthy volunteers were isolated and flow cytometry was performed to measure the state of activation, Fas expression and apoptosis of PBLs. Functionality of Fas was tested by assessing apoptosis after incubation of isolated lymphocytes with agonistic anti-Fas antibodies in blood samples treated with both E-CAB-94011 and E-JUR-94013. Studies on the lymphocyte cell marker suggest a clear immune activation as measured by the increased levels of CD25, CD8, CD38, CD19 and HLA-DR in vitro expression on lymphocytes treated with both extracts. In addition, a significant reduction in the percentages of apoptotic CD19(+)CD38(+) double positive lymphocytes could be demonstrated in the treated samples with respect to controls (p<0.05). Therefore the present results indicate that both E-CAB-94011 and E-JUR-94013 in vitro are powerful immunoregulatory, increasing immune surveillance.

Association between APOE epsilon4 allele and increased expression of CD95 on T cells from patients with Alzheimer's disease

Alzheimer's disease (AD) is the most prevalent neurodegenerative disorder, characterized by progressive impairment of cognitive functions. AD has a strong and complex genetic etiology, and multiple genes, acting independently and/or interacting, likely to influence the risk of developing AD. To test whether the expression of Fas receptor is upregulated in peripheral blood T lymphocytes and whether or not it correlates with APOE genotypes, 88 patients with AD and 24 normal individuals as controls were included in this study. T lymphocytes from patients as opposed to controls did undergo DNA fragmentation after in vitro exposure to IgM anti-Fas. In addition, several activation markers (CD25, HLA-DR, and CD45R0) were increased after 72 h in culture with respect to the controls, and Fas expression was also significantly different from the control group (p < 0.01). Reverse transcription PCR for Fas mRNA yielded the same results. T cells from both patients and controls showed upregulation of Fas receptor expression after in vitro anti-CD3 stimulation. Co-culture experiments with interleukin-4 downmodulated surface Fas receptor expression on T cells from patients and at a lesser extent in the control group. AD patients with the APOE allele 4 showed an increased expression of CD95 (53% +/- 6) with respect to APOE allele 3 (38% +/- 4). The control group showed a 22% +/- 3 (allele 4) and 31% +/- 5 (allele 3), respectively. Hyperexpression of Fas mRNA and surface Fas receptor on CD45RO(+) T lymphocytes may explain the occurrence of inflammatory cellular infiltrates in the CNS of AD patients.

Genomics and phenotypic profiles in dementia: implications for pharmacological treatment

Constitutive genomics are probably determinant for the onset of dementia in conjunction with cerebrovascular and environmental factors. Furthermore, pharmacogenomic studies predict that the therapeutic response in Alzheimer's disease (AD) is genotype-specific, and that the expression of genes involved in the regulation of drug metabolism can influence efficacy and safety issues in pharmacotherapy. AD and dementia with a vascular component (DVC = VD + MXD) are the most prevalent forms of dementia. These clinical entities share many similarities, but they differ in major phenotypic and genotypic profiles, as revealed by structural and functional genomics studies. Comparative phenotypic studies have identified significant differences in 25% of more than 100 parametric variables, including anthropometry, cardiovascular function, aortic atherosclerosis, brain atrophy, blood pressure, blood biochemistry, hematology, thyroid function, folic acid and vitamin B(12) levels, brain hemodynamics and lymphocyte markers. The phenotypic profile of patients with DVC differs from that of AD patients in the following: (a) anthropometric values, (b) cardiovascular function, (c) blood pressure, (d) lipid metabolism, (e) uric acid levels, (f) peripheral calcium levels, (g) liver function (GOT, GPT, GGT), (h) alkaline phosphatase, (i) lactate dehydrogenase, (j) red and white blood cells, (k) regional brain atrophy (left temporal region, inter-hippocampal distance) and (l) brain blood flow velocity. Functional genomics studies incorporating APOE-related changes in biological markers extended the difference between AD and DVC up to 57%. Structural genomics studies with AD-related genes, including APP, MAPT, APOE, PS1, PS2, A2M, ACE, AGT, cFOS and PRNP genes, demonstrate different genetic profiles in AD and DVC, with an absolute genetic variation rate ranging from 30 to 80%, depending upon genes and genetic clusters. Single gene analysis identifies relative genetic variations ranging from 0 to 5%. The relative polymorphic variation in genetic clusters integrated by 2, 3 or 4 genes associated with AD ranges from 1 to 3%. The main phenotypic differences between AD and DVC are genotype-dependent, especially in AD, probably indicating that different genomic factors are essential for the expression of dementia symptoms that might be accelerated or induced by environmental and/or cerebrovascular factors.

Allelic variants of the thiopurine methyltransferase (TPMT) gene in the Colombian population

Thiopurine methyltransferase (TPMT) catalyzes the inactivation of thiopurine drugs (mercaptopurine, thioguanine and azathioprine) used to treat acute lymphoblastic leukemia, autoimmune diseases and recipients of transplanted organs. No endogenous substrates for this enzyme are known. The TPMT polymorphism is a major determinant of individual differences in the toxicity or therapeutic efficacy of these drugs. The molecular basis of this polymorphism has been established in Caucasians, Africans, African-Americans and Asians, but not yet in the heterogeneous Latin American groups, including the Colombian population. The frequency of the four allelic variants of the TPMT gene, TPMT*2 (G238C), TPMT*3A (G460A and A719G), TPMT*3B (G460A) and TPMT*3C (A719G), were determined in 140 Colombian volunteers of Mestizo origin, using allele-specific PCR and PCR-RFLP assays. The *3A allele was found in 10 samples and the *2 allele in one, all heterozygotes; neither homozygous mutant genotypes nor the *3B and *3C alleles were detected. In agreement with these results, 92.1% and 7.9% of the Colombian population correspond to the phenotypes high and intermediate methylators, respectively. These results show that the frequency of mutations and the allelic distribution of the TPMT gene in the Colombian population are similar to the genetic profile found among US and European Caucasian populations, where the *3A allele is prevalent and the *2 allele is currently present.

Neuroprotection by memantine against neurodegeneration induced by beta-amyloid(1-40)

Progressive neuronal loss and cognitive decline in Alzheimer's disease (AD) might be aggravated by beta-amyloid-enhanced excitotoxicity. Memantine is an uncompetitive NMDA receptor antagonist under clinical development for the treatment of AD. Memantine has neuroprotective actions in several in vitro and in vivo models. In the present study, we determined whether memantine protected against beta-amyloid induced neurotoxicity and learning impairment in rats. Twenty Sprague-Dawley rats received vehicle or vehicle plus memantine (steady-state plasma concentrations of 2.34+/-0.23 microM, n=10) s.c. by osmotic pump for 9 days. After 2 days of treatment, 2 microl of water containing beta-amyloid 1-40 [Abeta(1-40)] were injected into the hippocampal fissure. On the ninth day of treatment, animals were sacrificed, and morphological and immunohistochemical techniques were used to determine the extent of neuronal degeneration and astrocytic and microglial activation in the hippocampus. Psychomotor activity and spatial discrimination were tested on the eighth day of treatment. Abeta(1-40), but not water, injections into hippocampus led to neuronal loss in the CA1 subfield, evidence of widespread apoptosis, and astrocytic and microglial activation and hypertrophy. Memantine treated animals had significant reductions in the amount of neuronal degeneration, pyknotic nuclei, and GFAP immunostaining as compared with vehicle treated animals. These data suggest that memantine, at therapeutically relevant concentrations, can protect against neuronal degeneration induced by beta-amyloid.

Enhancement in immune function and growth using E-JUR-94013 supplementation

Animal studies suggest that fish oils are capable of modulating the cell functions of immune system and there is some evidence that the effects of fish oils on immune function are due to fatty acids rather than trace elements or antioxidants. The major objectives of this study were: i) to identify a fish species with high nutritional value able to improve pig feeding conditions; ii) to utilize diets that modulate the immune system early in life in pigs and; iii) to enhance growth rate on a physiological basis. With the aim of maximizing feeding intake after weaning in order to reduce stress and increase growth rate, a study was carried out on 300 pigs supplemented with different fish extracts obtained by advanced biotechnological methods. The results of this work suggest that the lipoproteins obtained from the Trachurus trachurus (E-JUR-94013) species may have a great effect as both an immunomodulating compound (acting mainly on the regulation of IgA synthesis and/or release) and as a hypocholesterolemic compound, reducing the total cholesterol level in the serum of treated pigs. Both effects resulted in better pig growth, demonstrating that E-JUR-94013 can also be used as a natural growth promoter and an immune enhancer.

Histamine function in brain disorders

The neurotransmitter histamine (HA) has been implicated in the regulation of numerous and important activities of the central nervous system as arousal, cognition, circadian rhythms and neuroendocrine regulation. The data presented here indicate the participation of the histaminergic system in central nervous system disorders, such as Alzheimer's disease and schizophrenia. We also present experimental data on histamine in an animal model of neurodegeneration and the cytotoxic effects of histamine on cultured rat endothelial cells. More studies are needed to investigate the role of the histaminergic system in central nervous system disorders. Peripheral cellular studies in health and disease, molecular studies on receptors and in vivo pharmacological studies may help us to better understand the function of the histaminergic system in health and disease.

Celastrol, a potent antioxidant and anti-inflammatory drug, as a possible treatment for Alzheimer's disease

In the brains of patients with Alzheimer's disease (AD) signs of neuronal degeneration are accompanied by markers of microglial activation, inflammation, and oxidant damage. The presence of nitrotyrosine in the cell bodies of neurons in AD suggests that peroxynitrite contributes to the pathogenesis of the disease. A drug with antioxidant and anti-inflammatory activity may prevent neuronal degeneration in AD. Celastrol, a plant-derived triterpene, has these effects. In low nanomolar concentrations celastrol was found to suppress the production by human monocytes and macrophages of the pro-inflammatory cytokines TNF-alpha and IL-1beta. Celastrol also decreased the induced expression of class II MHC molecules by microglia. In macrophage lineage cells and endothelial cells celastrol decreased induced but not constitutive NO production. Celastrol suppressed adjuvant arthritis in the rat, demonstrating in vivo anti-inflammatory activity. Low doses of celastrol administered to rats significantly improved their performance in memory, learning and psychomotor activity tests. The potent antioxidant and anti-inflammatory activities of celastrol, and its effects on cognitive functions, suggest that the drug may be useful to treat neurodegenerative diseases accompanied by inflammation, such as AD.

A pharmacogenomic approach to Alzheimer's disease

Single nucleotide polymorphisms (susceptibility genetics) and genomic point mutations (mendelian genetics) can be used in Alzheimer's disease (AD) for diagnostic, predictive and therapeutic purposes. Using a matrix genetic model, including APOE, PS1 and PS2 allelic variants, we have studied the distribution of 36 different genotypes in the AD population (N= 479) and the genotype-related cognitive response to a multifactorial therapy in AD patients with mild-to-moderate dementia. The 10 most frequent AD genotypes are the following: 1) E33P112P2 + (17.75%), 2) E33P112P2- (15.55%), 3) E33P111P2+ (10.85%), 4) E34P112P2+ (9.60%), 5) E34P112P2- (7.56%), 6) E33P111P2- (7.10%), 7) E34P111P2+ (4.80%), 8) E33P122P2+ (4.38%), 9) E34P111P2- (4.18%), and 10) E34P122P2+ (3.55%). APOE-4/4-related genotypes represent less than 3% in the following order: E44P112P2 + > E44P111P2+ = E44P111P2- > E44P112P2+ > E44P122P2+ = E44P122P2. Multifactorial therapy with CDP-choline (1,000 mg/day) + piracetam (2,400 mg/day) + anapsos (360 mg/day) did improve mental performance during the first 6-15 months in a genotype-specific fashion. The best responders in the APOE series were patients with APOE-3/4 genotype (r= +0.013), while the worst responders were APOE-4/4 patients (r= -0.93). PS1-related genotypes responded in a similar manner; and patients with a defective PS2 gene exon 5 (PS2+) always showed a poorer therapeutic response than PS2- patients. All these data suggest that the therapeutic outcome in AD exhibits a genotype-specific pattern, and that a pharmacogenomic approach to AD might be a valuable strategy for drug development and monitoring.

Oral Cerebrolysin enhances brain alpha activity and improves cognitive performance in elderly control subjects

Cerebrolysin is a porcine brain derived peptide preparation with potential neurotrophic activity. The effects of a single oral dose of the Cerebrolysin solution (30 ml) on brain bioelectrical activity and on cognitive performance were investigated in healthy elderly people. A single oral dose of Cerebrolysin induced a progressive increase in relative alpha activity power from 1 to 6 hours after treatment in almost all the brain electrodes in elderly control subjects. As compared with baseline alpha power (45.8+/-9.5%), the increase in relative alpha activity in the left occipital electrode (O1) reached significant values at 1 hour (57.2+/-8.5%; p < 0.05), 3 hours (59.4+/-7.6%; p < 0.05) and 6 hours (63.4+/-9.8%; p < 0.05) after Cerebrolysin administration. Enhancement in relative alpha power was accompanied by a generalized decrease in slow delta activity that was maximum at 6 hours after Cerebrolysin intake. A significant improvement in memory performance, evaluated with items of the ADAS cog, was also found in elderly people taken a single dose of oral Cerebrolysin (6.9+/-1.0 errors at baseline versus 4.9+/-1.0 errors after treatment; p < 0.01). This memory improvement was more evident in recognition (2.8+/-0.6 errors vs. 1.5+/-0.7 errors; p < 0.05) than in recall tasks (4.1+/-0.5 errors versus 3.4+/-0.5 errors; ns). These data indicate that Cerebrolysin potentiates brain alpha activity, reduces slow EEG delta frequencies and improves memory performance in healthy elderly humans, suggesting that this compound activates cerebral mechanisms related to attention and memory processes. According to the present results, it seems that oral Cerebrolysin might be useful for the treatment of memory impairment and brain damage in eldely subjects with or without neurodegenerative disorders.

Isolation, sequence and genotyping of the drug metabolizer CYP2D6 gene in the Colombian population

Cytochrome P450 2D6 monooxygenase metabolizes several commonly used drugs, particularly psychotropics and cardiovascular agents. The gene that encodes this isoenzyme is highly polymorphic, with 1-10% of the population carrying mutations that produce an inactive enzyme, and 1-29% of individuals who possess additional copies of functional CYP2D6 genes. The genotypic features of the CYP2D6 gene have already been studied in many ethnic groups; however, the genetic characteristics of this enzyme are unknown in the Colombian population. The allelic variants and mutations of this polymorphic isoenzyme are the main cause of interindividual and interethnic differences in the therapeutic efficacy and adverse effects at standard doses of drugs metabolized by the products of the CYP2D6 gene. In the present study we have isolated, sequenced and genotyped the CYP2D6 gene in the Colombian population. The distribution of allelic frequencies of 10 alleles associated with normal, diminished or increased CYP2D6 activity has been studied in 121 healthy volunteers. The commonest alleles detected in the Colombian people were the functional alleles *1 (38.8%) and *2 (37%). Among the seven nonfunctional alleles studied in our sample, we found frequencies of 19.4%, 1.6%, 1.2% and 0.8%, for the *4, *17, *3 and *5 alleles, respectively. The alleles *6, *7 and *8 could not be identified in any of the subjects studied. The frequency of the duplicate allele was 1.2%. In this Colombian sample, 91.7% of the individuals were normal metabolizers (EM), 6.6% were poor metabolizers (PM), and 1.7% were ultrarapid metabolizers (UM). These results show that the allelic distribution of the CYP2D6 gene in the Colombian population of mestizo-prevalent subjects is compatible with the genomic assembly of the constitutive tri-ethnic origin of this Latin American country.

Double-blind, randomized, placebo-controlled pilot study with anapsos in senile dementia: effects on cognition, brain bioelectrical activity and cerebral hemodynamics

The aim of this study was to evaluate the effects of two doses of anapsos in comparison with placebo on cognitive performance, brain bioelectrical activity pattern and cerebral hemodynamic parameters in patients with mild to moderate senile dementia of vascular type and Alzheimer type. Forty-five patients (age 73.8 +/- 7.6 years; range 56-89 years) with mild to moderate senile dementia (Global Deterioration Scale: stages 3-5) of the vascular (VD; n = 22) or the Alzheimer type (AD; n = 23) were included in a double-blind randomized placebo-controlled clinical trial. After a 2-week period of drug washout, patients were treated with placebo (n = 15; age 72.7 +/- 7.5 years), 360 mg/day of anapsos (n = 15; age 75.5 +/- 7.2 years), or 720 mg/day of anapsos (n = 15; age 73 +/- 7.7 years) for 4 weeks (28 days). At baseline and after the 4-week period of double-blind treatment, cognitive performance, brain bioelectrical activity power and blood flow hemodynamics in the middle cerebral arteries were evaluated with ADAScog, brain mapping and transcranial Doppler ultrasonography, respectively. Patients receiving 360 mg/day of anapsos showed a significant improvement in cognitive performance after treatment (ADAScog scores: p < 0.05) that was not observed in patients treated with placebo or 720 mg/day of anapsos. As compared to placebo, anapsos (360 mg/day) induced a significant improvement in ADAScog scores in mild senile dementia patients (p < 0.01) and in the subset of patients with AD (p < 0.05). Anapsos (360 mg/day) also increased cerebral blood flow velocities in left and right middle cerebral arteries in the subgroup of AD patients, whereas with the dose of 720 mg/kg this increase was only observed in the left side. Patients treated with anapsos (360 mg/day) showed a decrease in relative delta power and an increase in relative theta and alpha brain bioelectrical activity frequencies, indicating an acceleration of the EEG pattern. The present results show that anapsos (360 mg/day) improves cognitive performance, cerebral blood perfusion and brain bioelectrical activity in patients with senile dementia. These effects of anapsos were more marked in demented patients with mild mental deterioration and/or with dementia of the Alzheimer type.

Pharmacological treatment of Alzheimer disease: from psychotropic drugs and cholinesterase inhibitors to pharmacogenomics

For the past 20 years the scientific community and the pharmaceutical industry have been searching for treatments to neutralize the devastating effects of Alzheimer disease (AD). During this period important changes in the etiopathogenic concept of AD have occurred and, as a consequence, the pharmacological approach for treating AD has also changed. During the past 2 decades only 3 drugs for AD have been formally approved by the FDA, although in many countries there are several drugs which are currently used as neuroprotecting agents in dementia alone or in combination with cholinesterase inhibitors. The interest of the pharmaceutical industry has also shifted from the cholinergic hypothesis which led to the development of cholinesterase inhibitors to enhance the bioavailability of acetylcholine at the synaptic cleft to a more "molecular approach" based on new data on the pathogenic events underlying neurodegeneration in AD. In our opinion, the pharmacological treatment of AD should rely on a better understanding of AD etiopathogenesis in order to use current drugs that protect the AD brain against deleterious events and/or to develop new drugs specifically designed to inhibit and/or regulate those factors responsible for premature neuronal death in AD. The most relevant pathogenic events in AD can be classified into main categories: primary events (genetic factors, neuronal apoptosis), secondary events (beta-amyloid deposition in senile plaques and brain vessels, neurofibrillary tangles due to hyperphosphorylation of tau proteins, synaptic loss), tertiary events (neurotransmitter deficits, neurotrophic alterations, neuroimmune dysfunction, neuroinflammatory reactions) and quaternary events (excitotoxic reactions, calcium homeostasis miscarriage, free radical formation, primary and/or reactive cerebrovascular dysfunction). All of these pathogenic events are potential targets for treatment in AD. Potential therapeutic strategies for AD treatment include palliative treatment with nonspecific neuroprotecting agents, symptomatic treatment with psychotropic drugs for noncognitive symptoms, cognitive treatment with cognition enhancers, substitutive treatment with cholinergic enhancers to improve memory deficits, multifactorial treatment using several drugs in combination and etiopathogenic treatment designed to regulate molecular factors potentially associated with AD pathogenesis. This review discusses the conventional cholinergic enhancers (cholinesterase inhibitors, muscarinic agonists), noncholinergic strategies that have been developed with other compounds, novel combination drug strategies and future trends in drug development for AD treatment. Stem-cell activation, genetically manipulated cell transplantation, gene therapy and antisense oligonucleotide technology constitute novel approaches for the treatment of gene-related brain damage and neuroregeneration. The identification of an increasing number of genes associated with neuronal dysfunction along the human genome together with the influence of specific allelic associations and polymorphisms indicate that pharmacogenomics will become a preferential procedure for drug development in polygenic complex disorders. Furthermore, genetic screening of the population at risk will help to identify candidates for prevention among first-degree relatives in families with transgenerational dementia.

Pharmacogenomics in Alzheimer's disease

Scientists from the EuroEspes Biomedical Research Center, La Coruna, Spain, presented the conclusions of a pharmacogenomics study in Alzheimer's disease at the Sixth International Stockholm/Springfield Symposium on Advances in Alzheimer Therapy, held in Stockholm, April 5-8, 2000. The authors carried out a genomic screening to search for potential genes associated with neuronal death and found that in practically all 23 human chromosomes, except chromosome 16, there is at least one gene whose dysfunction is associated with neuronal death and/or dementia-related syndromes. This distribution of genomic loci related to neurodegeneration could indicate that is unlikely that a single drug would be capable of preventing neuronal death in subjects with a multifactorial, polygenic disease and that a genotype-related differential response should be expected in AD patients treated with any potential neuroprotective drug. It is suggested that AD patients be genotyped prior to the administration of novel drugs and that a pharmacogenomics approach to AD treatment would help in the development of more effective drugs and in the prediction of therapeutic responses.

Cerebrolysin reduces microglial activation in vivo and in vitro: a potential mechanism of neuroprotection

Neurotrophins, such as NGF, BDNF and NT-3 play a regulatory role on the function of microglial cells in vivo and in vitro, and the identification of new compounds with neurotrophic properties is becoming a new strategy for the prevention and/or treatment of neurodegenerative disorders. In this study we describe the use of two different models to demonstrate the ability of Cerebrolysin to reduce microglial activation. The results of these in vitro and in vivo studies indicate that Cerebrolysin might exert a neuroimmunotrophic activity reducing the extent of inflammation and accelerated neuronal death under pathological conditions such as those observed in neurodegenerative diseases.

Double-blind placebo-controlled study with citicoline in APOE genotyped Alzheimer's disease patients. Effects on cognitive performance, brain bioelectrical activity and cerebral perfusion

Cytidine 5'-diphosphocholine (citicoline) is a an endogenous intermediate in the biosynthesis of structural membrane phospholipids and brain acetylcholine. Citicoline has been extensively used for the treatment of neurodegenerative disorders associated with head trauma, stroke, brain aging, cerebrovascular pathology and Alzheimer's disease. In this study we have investigated the efficacy and safety of the treatment with citicoline versus placebo in patients with Alzheimer disease. Thirty patients (age = 73.0 +/- 8.5 years; range = 57-87 years) with mild to moderate senile dementia (GDS: stages 3-6) of the Alzheimer type were included in a double-blind, randomized and placebo-controlled clinical trial. After a 2-week period of drug washout, patients were treated with i) placebo (n = 17; age = 73 +/- 5 years) or ii) 1,000 mg/day of citicoline (n = 13; age = 76 +/- 9 years) for 12 weeks (84 days). Examinations were done at baseline (T0) and after the 12 weeks of treatment (T12). As compared to placebo, citicoline improved cognitive performance in Alzheimer's disease patients with APOE E4 (ADAS: difference between groups = -3.2 +/- 1.8 scores, p < 0.05; ADAS-cog: difference between groups = -2.3 +/- 1.5, ns); and this improvement on cognition was more pronounced (ADAS, p < 0.01; ADAS-cog: difference between groups = -2.8 +/- 1.3, p < 0.06) in patients with mild dementia (GDS < 5). Citicoline also increased cerebral blood flow velocities in comparison with placebo (p < 0.05) when transcranial Doppler recordings from both hemispheres were considered together, as well as diastolic velocity in the left middle cerebral artery (p < 0.05). Patients treated with citicoline showed an increase in the percentage of brain bioelectrical activity of alpha (occipital electrodes) and theta type (left side electrodes), accompanied by a decrease in relative delta activity particularly marked in the left temporal lobe. Significant differences with respect to placebo (p < 0.05) were observed for theta activity in several fronto-parieto-temporal electrodes of the left hemisphere. Treatment with citicoline tended to reduce serum IL-1 beta levels, mainly after 4 weeks of administration, with no modified blood histamine content. In addition, neither adverse side effects nor alterations in biological and hematological parameters were induced by citicoline. The present data indicate that citicoline (1,000 mg/day) is well tolerated and improves cognitive performance, cerebral blood perfusion and the brain bioelectrical activity pattern in AD patients. According to our results, it seems that citicoline might be a useful treatment in Alzheimer's disease, and that the efficacy of this compound is greater in patients with mild mental deterioration and/or bearing the epsilon 4 allele of the APOE.

Citicoline protects hippocampal neurons against apoptosis induced by brain beta-amyloid deposits plus cerebral hypoperfusion in rats

Citicoline is an endogenous intermediate involved in the biosynthesis of brain phospholipids and acetylcholine which has been extensively used for the treatment of several neurodegenerative conditions. The effects of citicoline on neurodegeneration, apoptosis and learning were investigated in male Sprague Dawley rats subjected to implants of the beta-amyloid fragment 1-40 (A beta 4: 3 Mmol) into the right hippocampus and to permanent unilateral occlusion of the carotid artery. Citicoline (CDP; 0, 62.5, 125 and 250 mg/kg/day i.p.) was given during 2 days before and for 5 days after surgery, and the extension of the degeneration and the number of apoptotic figures (TUNEL technique) were evaluated in the dentate gyrus (DG) and the CA1 area of the hippocampus. Citicoline, at 125 and 250 mg/kg, reduced the number of apoptotic neurons in the hippocampus of rats with A beta 4/hypoperfusion-induced neurodegeneration (CDP0 = 105.3 +/- 32.8 apoptotic figures; CDP125 = 39.2 +/- 7.4** apoptotic figures; CDP250 = 34.5 +/- 14.4** apoptotic figures; **p < 0.01 vs. CDP0). CDP also reduced neuronal degeneration in the CA1 area in a dose-dependent manner (CDP0 = 450.5 +/- 130.1 microns; CDP62.5 = 280.6 +/- 76.3 microns; CDP125 = 86.6 +/- 37.3* microns; CDP250 = 121.7 +/- 85.3* microns; p < 0.05 vs. CDP0). Variability of results was very high in the DG, where a significant reduction in the extent of neurodegeneration was only observed in the group of rats receiving 62.5 mg/kg of citicoline. Finally, citicoline improved retention of a passive avoidance learning task, increasing the number of avoidances (Av) (CDP0 = 4.2 +/- 0.7 Av; CDP62.5 = 6.9 +/- 1.0 Av; CDP125 = 7.9 +/- 0.7** Av; CDP250 = 8.5 +/- 0.6** Av; **p < 0.01 vs. CDP0) in a dose-related manner. Based on these results, it was concluded that citicoline exerts antiapoptotic, neuroprotective and antiamnesic effects in conditions of neurodegeneration induced by A beta 4 plus hypoperfusion.

Characterization of cytokine production, screening of lymphocyte subset patterns and in vitro apoptosis in healthy and Alzheimer's Disease (AD) individuals

In order to investigate the possibility of whether or not the lymphocytes of patients with Alzheimer's Disease (AD) are in an activated state, blood mononuclear cells from 45 AD patients and 45 healthy age matched controls were immunophenotyped by measuring the expression of CD3, CD4, CD7, CD8, CD25, CD28, CD56 and HLA-DR by flow cytometry. Circulating and in-vitro-produced cytokines were also measured by ELISA tests. CD7 and CD8 were significantly decreased in AD patients (48.3% and 18.2%, respectively) when compared to healthy subjects (63.2% and 28.3%, respectively). A significant increase in the CD4, CD25 and CD28 antigen expression was also observed in the AD group (55.3% 24.8% and 65.1%) with respect to healthy subjects (44.5%, 10.3% and 54.3%). In addition there was a significant difference in the extent of apoptosis in lymphocyte culture, as measured by mean fluorescence intensity (MFI) of Fas antigen (CD95) expression on CD4+ T cells in 6 AD patients (MFI = 36% and 43%, by anti-CD3 and hyperthermia mediated-apoptosis, respectively) with respect to 6 healthy individuals (MFI = 24% and 31%, by anti-CD3 and hyperthermia mediated-apoptosis, respectively), as well as in T-cell proliferation assay. A decline of Fas antigen expression on CD8+ subset was observed in the AD group with both stimuli (19% and 28%) comparing to the control group (29% and 39%). No differences were observed on circulating cytokines and spontaneous in vitro production of proinflammatory interleukin 1beta (IL-1beta), Tumor Necrosis Factor-alpha (TNF-alpha), IL-6 and IL-10 cytokines. Lipopolysaccharide (LPS)-stimulated in vitro production of IL-1beta, TNF-alpha, IL-6 and IL-10 measured by a whole blood culture system was significantly higher in AD patients comparing to controls. Furthermore, the observed differences were more evident at late stages of disease. These findings suggest that immunological tests, based on lymphocyte immunophenotyping combined with pro-inflammatory cytokine determinations and measurement of apoptosis in peripheral blood might represent a useful tool to obtain more insight into the pathogenesis of AD and into the level of immune activation which could characterize the pathological state of lymphocytes from individual AD patients.

Effects of Cerebrolysin on in vitro primary microglial and astrocyte rat cell cultures

In recent years the potential use of neurotrophic factors in the prevention and/or treatment of neurodegenerative diseases has received much attention. To determine whether Cerebrolysin, a porcine brain-derived peptide preparation, was able to modulate in vitro lipopolysaccharide (LPS)-induced microglial activation and to test the direct effect of Cerebrolysin on astrocyte morphology, survival and proliferation, rat glial and astrocyte cell culture experiments were carried out. The morphology of microglia, ameboid/activated and flat/resting, was examined under contrast microscopy and cell counts obtained. In addition, the release of interleukin (IL)-1 beta and brain-derived neurotrophic factor (BDNF) was measured from cell culture supernatant using an enzyme-linked-immunoassay (ELISA). The results obtained in this study clearly suggest a protective effect of Cerebrolysin as revealed by downregulation of microglial activation after LPS treatment as well as by the control of IL-1 beta expression. No significant differences were observed on astrocyte morphology, survival or the production and/or release of BDNF. In conclusion, these in vitro studies indicate that Cerebrolysin might exert a neuroimmunotrophic function which can in turn reduce the extent of inflammation and accelerate neuronal death under pathological conditions such as human neurodegenerative disorders.

19/20 kDa low molecular weight serum protein pattern: a novel potential biochemical prognostic marker for different types of dementia

In recent years, several attempts have been made to identify biochemical and/or genetic markers which might have diagnostic and prognostic uses for Alzheimer's disease (AD). To look for possible new blood markers, a longitudinal study was carried out in our Central Nervous System Biomedical Research Center between October 1996 and July 1998. A total of 30 AD subjects were diagnosed as AD patients according to the DSM-IV and NINCDS-ADRDA criteria. Vascular dementia (VD, n= 17), mixed dementia (MXD, n = 18) and healthy age-matched control subjects (n = 15) have been included in the study. Serum samples have been analysed by SDS-PAGE (sodium dodecyl sulfate polyacrylamide gel electrophoresis) and the resulting protein patterns have been compared. The objectives of this study were to examine the presence of peripheral markers among patients with AD, VD and MXD and to explore the relationship between serum markers and APOE genotype. The findings suggest that two proteins of 19 and 20kDa molecular weight, respectively, might be associated with disease progression in different types of dementia.

Microglial activation induced by factor(s) contained in sera from Alzheimer-related ApoE genotypes

Several factors that increase the likelihood of developing Alzheimer's disease (AD) have already been identified. A correct evaluation of these may contribute to a better understanding of the etiology of the disease. The risk of developing AD definitely increases with (a) age, (b) head injuries, (c) family history of AD or Down syndrome, (d) sex (higher prevalence of AD in women), (e) vascular disease, (f) exposure to environmental toxins, (g) infectious processes, or (h) changes in immune function, and recent advances in molecular genetics have suggested that genetic predisposition (i) can be considered one of the most important risk factors in the development of AD. A significant increase in the number of amyloid plaques in AD patients with an apolipoprotein E4 (ApoE) allele has been observed and the results of several genetic studies indicate that the etiology of this neurodegenerative disease is associated with the presence of the allele E4 of ApoE. A potential source of damage in the AD brain is an altered response triggered by microglial activation, which is associated with amyloid plaques. It has become evident that a dysregulation of cytokine release appears within lesions of many types of brain disorders including infection, trauma, stroke, and neurodegenerative diseases. Many studies have shown that microglia secrete both cytokines and cytotoxins and since reactive microglia appears in nearly every type of brain damage, it is likely that their secreted products ultimately help to determine the rate of damaged brain tissue. In this study, in vitro cell cultures were established to investigate the effect of different concentrations of human sera (2.5% and 10%) with specific ApoE genotypes from Alzheimer's and non-Alzheimer's subjects on ameboid and flat microglial cells obtained from neonatal rat hippocampi. Results show that a modulation in the proliferation and activation of microglial cells was obtained and that AD sera, mainly in the ApoE 3/4 and 4/4 genotype contain factor(s) which are able to induce morphological changes, as measured by an increase in the ameboid cell type. In addition, major histocompatibility complex (MHC) class II antigen expression, as measured by flow cytometric analysis, and interleukin-1beta (IL-1beta) release as measured by enzyme linked immunoadsorbent assay (ELISA), in comparison with control groups and lipopolysaccharide (LPS)-treated cells, clearly demonstrate a direct effect of ApoE 3/4 and 4/4 and/or an indirect effect mediated by the release of IL-1beta on microglia activation. These results strongly suggest that primary in vitro microglial cell cultures can be used as a screening model to test human sera as well as the effect of new potential drugs aimed at down-regulating microglia activation.

Neuroprotective role of S12024 against neurodegeneration in the rat dentate gyrus

We assessed the neuroprotective capabilities of S12024 (R,S 1-methyl 8-(2-morpholinylmethoxy)-1,2,3,4-tetrahydroquinoleine methane sulphonate) in a model of neuronal degeneration in the dentate gyrus of the rat hippocampus. Specific degeneration of a large part of neurons in the lateral blade of the gyrus dentatus occurred after small intrahippocampal injections of water with or without amyloid-beta 1-28 fragment. S12024 reduced the number of animals with neuronal loss in the hippocampus, diminished the extent of the lesion, and reversed deficits of passive avoidance learning acquisition in animals with deposits of amyloid-beta 1-28. These results suggest that S12024 has neuroprotective effects on hippocampal cells and that the neurodegeneration by fluid injection combined with deposit of amyloid-beta 1-28 may be used to assay the neuroprotective activity of pharmacological compounds.

A novel mutation in the predicted TM2 domain of the presenilin 2 gene in a Spanish patient with late-onset Alzheimer's disease

Mutations in the presenilin-2 (PS-2) gene are less frequent than mutations in the PS-1 gene. All mutations described in the PS-1 gene were found in early-onset Alzheimer's disease (AD) patients. At present, there are two missense mutations described for the PS-2 gene in some AD pedigrees. We have therefore analyzed transmembrane 2 (TM2) and TM5 domains of the PS-2 gene in AD patients and in a group of age-matched healthy controls. In a patient who was clinically diagnosed as having late-onset AD, we found a novel missense mutation consisting of a G->A substitution on exon 5 of the PS-2 gene, which results in a Val to Ile substitution at codon 148 within the predicted TM2 domain of the PS-2 protein. This is the third mutation described in the PS-2 gene and the first presenilin mutation detected in a Spanish AD patient. Both, the N141I mutation and the V148I mutation described here are located within the predicted TM2 domain and both were found in late-onset AD kindreds, whereas the mutation within the predicted TM5 domain was found in an early-onset AD pedigree. Carriers of mutations within TM2 of PS-1 have a mean age at onset of 40 years, while the other mutations in PS-1 occur in families with a mean age at onset of 47 years. In summary, we report here the first mutation in a presenilin gene in a Spanish AD case, which is the third mutation detected for the PS-2 gene.

Plasticity of Congo red staining displayed by subpopulations of neurons within the rat central nervous system

We document the presence of subpopulations of neurons within the rat central nervous system that are labelled with a new Congo red staining technique. These neurons (CR neurons) show shrunken somata, and smaller and darker nuclei than Congo red-negative cells (non-CR cells). With the Bielschowsky and the cresyl violet Nissl staining methods, two comparable subpopulations of cells can be distinguished by the same morphometrical criteria as those used for CR and non-CR cells. CR neurons are located preferentially in some brain regions while in others they are virtually absent. Their distribution and proportion varied greatly from animal to animal and after particular treatments. Injections of water that damaged the hippocampal dentate gyrus, cortical lesions or eye enucleation decreased the number of CR-cells in the CA1 subfield, reflected in a shift from the CR-staining subclass to the non-CR subclass. Treatment with 200 mg/kg of CDP-choline also significantly reduced the number of CR cells observed in CA1. In the red nucleus, CR neurons showed a characteristic distribution of beta-amyloid precursor protein (APP) immunoreactivity. The population of dendrites immunolabelled for microtubule-associated protein 2 was markedly decreased in the areas of the hippocampus with high numbers of CR cells. Therefore, it is proposed that neurons labelled with the present Congo red technique might be in a reversible degenerative state or represent a particular physiological state in some areas of the central nervous system.

Beta-amyloid(1-40)-induced neurodegeneration in the rat hippocampal neurons of the CA1 subfield

Small volumes of solutions injected into the hippocampus produce dramatic degeneration in dentate gyrus neurons, but not in neurons of the CA1 subfield. The aim of the present study was to ascertain whether solutions with different fragments of the beta-amyloid protein (Abeta) could produce further degeneration in areas beyond the dentate gyrus. It was found that 5 days after injection of an aqueous solution containing the Abeta 1-40 fragment into the hippocampus, long stretches of the CA1 subfield were either deprived of neurons or most of the neurons were degenerating. By contrast, in animals with deposits containing Abeta 1-28, Abeta 1-42 or water, neuronal degeneration or depletion only occurred in a reduced area around the place where the implant needle penetrated the CA1 subfield. In animals injected with Abeta 1-40, many profiles in the CA1 subfield and dentate gyrus were undergoing apoptosis, as seen using preparations processed by routine histology or the TUNEL technique for detection of fragmented DNA. In addition, there was higher infiltration by ED1-positive, activated microglia-macrophagic cells in Abeta 1-42 deposits than in deposits of Abeta 1-40. The present results suggest that the intrahippocampal injection of toxic Abeta fragments produces neuronal degeneration in the rat CA1 subfield when using the appropriate protocol, and, thus, can provide an in vivo model to investigate the neurotoxic effects of Abeta and for the evaluation of drugs with potential anti-neurodegenerative activity.

Behavioral changes associated with different apolipoprotein E genotypes in dementia

Behavioral dysfunction is a problem in patients with Alzheimer disease (AD), and is apparent in up to 67% of individuals. Such changes are a primary cause of individual institutionalization and often lead to their functional disability. As AD progresses, the worsening of behavioral dysfunction becomes increasingly evident and is linked with decreased patient survival. Unfortunately, some of the more common drug therapies used in AD patients to stabilize other facets of their disease worsen behavioral dysfunction. Behavioral changes are associated with endogenous and exogenous factors such as disease stage, environmental factors, other medical conditions, drug regimen, and AD genotype. The most commonly examined and important genotype in AD is the apolipoprotein E (APO E) series, and APO E genotyping is also a useful diagnostic tool. The most frequent APO E genotypes encountered in AD are APO E-4/4, APO E-3/4, and APO E-3/3. In the current study, AD behavioral dysfunction, anxiety, and psychoses were commonly associated with the APO E-3/3 genotype, whereas disorientation, agitation, depression and motor disorders were common among patients with the APO E-4/4 and APO E-3/4 genotypes. These differences were not statistically significant but they suggest that different APO E genotypes influence the phenotypic expression of specific noncognitive symptoms, including behavioral function, in AD.

Intrahippocampal injections of the beta-amyloid 1-28 fragment induces behavioral deficits in rats

beta-amyloid (beta A) deposition is a key event in the etiopathogenesis of Alzheimer's disease (AD), contributing to neuronal degeneration and cognitive impairment in AD patients. Both neurotrophic and neurotoxic actions of beta A have been demonstrated in experimental conditions. In order to further characterize the effects of brain beta A deposits on behavioral processes, we evaluated psychomotor activity (PMA), psychomotor coordination (PMC) and learning in a passive avoidance task (PAL) in rats with unilateral or bilateral 2 microliters injections of beta-amyloid (1-28) protein (beta A; 1.5 nmol/microliter) or vehicle (water; W) into the hippocampus, 1 and 4 weeks after neurosurgery. The extent of neuronal loss in the lateral blade of the gyrus dentatus (LBGD) and the area percentage occupied by APP immunoreactivity in neurons of the CA3c subfield of the hippocampus were also measured in animals with unilateral beta A implants. PMA levels were similar in water- and beta A-injected animals 1 and 4 weeks after recovery. As compared to water-injected rats, beta A animals showed reduced PMC values 1 week, but not 4 weeks, after injections. beta A also impaired learning acquisition in a passive avoidance task, reducing the number of avoidances and mean latency per trial at both 1 and 4 weeks postsurgery in rats with unilateral or bilateral beta A implants. The extent of neuronal loss in the LBGD) was not different in rats receiving water or beta A injections. Hippocampal APP expression tended to increase in beta A-implanted rats and showed a negative correlation with cognitive performance at the 4-week period. According to these results it seems that beta A implants into the hippocampus reduce psychomotor coordination performance in a transient manner, with no effect on psychomotor activity, and induce durable learning impairment in rats, and that changes in cognitive performance correlate with histochemical parameters such as APP expression. In conclusion, the present results contribute to a better understanding of beta A-induced behavioral alterations and to the identification of potential molecular mechanisms involved in cognitive dysfunctions in this animal model of neurodegeneration.

Anapsos reverses interleukin-1 beta overexpression and behavioral deficits in nbM-lesioned rats

Rats with neurotoxic lesions, induced by single or double bilateral injections of ibotenic acid into different parts of the nucleus basalis of Meynert (nbM), showed increased psychomotor activity (PMA) and impaired learning in a passive avoidance task. Behavioral deficits were similar in all the groups of lesioned animals, suggesting that the lesion site was not relevant for the ibotenic effects under testing procedures used here. In another experiment, nbM-lesioned rats received acute or daily (5 days) i.p. injections of vehicle or anapsos (100 mg/kg) from the 7th day after surgery. Data indicated that nbM lesions induced an increased production of interleukin-1 beta (IL-1 beta), motor hyperactivity and learning impairment, and that anapsos, a vegetal extract with immunomodulatory activity, reversed brain IL-1 beta overexpression and behavioral alterations in lesioned rats. These results confirm the involvement of IL-1 beta in neurodegeneration associated with cholinergic deficits and the potential utility of compounds with neuroimmunotrophic activity as a new therapeutic strategy in neurodegenerative disorders.

Citicoline improves memory performance in elderly subjects

Citicoline is a choline donor involved in the biosynthesis of brain phospholipids and acetylcholine extensively used in the treatment of neurodegenerative diseases. In this study we investigated the effects of the oral administration of citicoline alone (C1000:1000 mg/day; C500:500 mg/day) or in combination with nimodipine (C +NI:300 + 90 mg/day) during 4 weeks on memory performance in elderly subjects with memory deficits and without dementia (N = 24; age = 66.12 +/- 10.78 years; MMS score = 31.69 +/- 2.76). Results indicated that citicoline in comparison with placebo improves memory in free recall tasks, but not in recognition tests. A significant improvement in word recall (5.17 +/- 1.1 vs. 3.95 +/- 1.2 omissions; p < 0.005), immediate object recall (6.5 +/- 1.6 vs. 5.5 +/- 1.2 omission; p < 0.05) and delayed object recall (8.5 +/- 2.1 vs. 6.7 +/- 2.4 omissions; p < 0.005) was observed after citicoline treatment. Similar results were found in the three subgroups of treatment (8 subjects per group), suggesting that citicoline possesses memory-enhancing activity at doses of 300-1000 mg/day. A decrease in systolic blood pressure and minor changes in lymphocyte cell counting were also observed in old subjects after receiving citicoline. These effects are consistent with the vasoregulatory and neuroimmune actions of citicoline and suggest that this compound may improve memory by acting on mechanisms of brain neurotropism and cerebrovascular regulation. According to the present results, showing that citicoline improves memory performance in elderly subjects, we concluded that this molecule is suitable for the treatment of memory deficits in old people.

A novel point mutation in the GTP cyclohydrolase I gene in a Spanish family with hereditary progressive and dopa responsive dystonia

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A general method for DNA polymorphism identification in genetic assessment and molecular diagnosis

A general methodology for the analysis of human diseases at the nucleic acid level has been described. This method consists of a semiautomated, nontoxic analytic procedure, staining DNA bands with silver nitrate instead of ethidium bromide after DNA amplification by PCR. This technique provides a sensitive assay with enhanced accuracy and offers the possibility of carrying out the molecular analysis of several polymorphisms in a single day simplifying molecular genetics with diagnostic purposes.

Effects of anapsos on the activity of the enzyme Cu-Zn-superoxide dismutase in an animal model of neuronal degeneration

The enzyme Cu-Zn-SOD is a metalloenzyme that catalyzes the dismutation of the superoxide radical into hydrogen peroxide and molecular oxygen, being a defense system against free radical formation. Free radical reactions are implicated in a variety of physiological and pathological processes as aging, apoptosis and neurodegenerative diseases, and abnormalities associated with SOD have been recently documented in several neurodegenerative processes. In this study, we have evaluated the effect of anapsos on Cu-Zn-SOD activity in rats with injections of beta-amyloid protein or water bilaterally into the hippocampus. These injections caused severe cell depletion in the gyrus dentatus. Anapsos is a biological extract obtained from the fern Polypodium leucotomos with immunomodulatory and anti-neoplastic effects tested in animals and humans. Cu-Zn-SOD activity was measured in the hypothalamus, hippocampus, cerebral cortex, liver and spleen of rats treated i.p. with three doses of anapsos for 7 days (4, 20 and 100 mg/kg/day). Control animals were treated with saline solution under the same conditions. Anapsos significantly modified enzyme activity in all the areas tested. Lower doses of anapsos produced decreased SOD activity in the hypothalamus, hippocampus, liver and spleen, while in the cerebral cortex, a significant dose-dependent increase in SOD activity was observed. These results indicate that anapos was able to modify Cu-Zn-SOD activity in this animal model of neuronal degeneration, which may indicate the participation of anapsos in mechanisms of tissue repair after brain damage.

An experimental model to study the cytotoxic effects induced by beta-amyloid, histamine, LPS and serum from Alzheimer patients on cultured rat endothelial cells

Lactate dehydrogenase (LDH) enzyme activity was measured in the supernatant of rat aortic endothelial cell cultures to evaluate the cytotoxic effects of two proinflammatory mediators such as LPS and histamine, as well as beta-amyloid protein (fragment 1-28) on endothelial cells. In the same culture we also studied the influence of different sera from patients with Alzheimer's disease (AD) or healthy elderly subjects. The results indicate that very low concentrations (1 microgram/ml) of beta-amyloid or histamine (1 microM) were able to produce cell damage after an incubation time of 4 h. Treatment with LPS induced cell damage at the highest concentration (2.5 micrograms/ml) after 24 h of incubation. When endothelial cells were treated with serum from AD and non-AD individuals, an inhibition of endothelial cell proliferation was observed only with activated AD serum. These results indicate that rat endothelial cell cultures represent an important model to study inflammatory mediators and to evaluate the therapeutic effect of antiinflammatory molecules in AD and other neurodegenerative disorders.

APOE-related frequency of cognitive and noncognitive symptoms in dementia

Although memory disorders and the aphaso-apraxo-agnosic syndrome are the most relevant clinical symptoms in dementia, behavioral changes, mood-related disturbances and sleep disorders are the major cause of institutionalization and caregiver concern. In the present study we have investigated the frequency and progression of cognitive and noncognitive symptoms in Alzheimer's disease (AD) as well as the APOE-related frequency of clinical symptoms in dementia. Memory decline (100%), aphasia (94%), apraxia (99%), agnosia (94%) and motor dysfunction (90%) appeared in practically all cases with mild (GDS-3), moderate (GDS 3-4) and severe (GDS 6-7) dementia. The most frequent noncognitive symptoms include anxiety (76%), depression (68%), behavioral changes (67%), psychotic symptoms (43%), sleep disorders (43%), incontinence (23%) and cerebrovascular symptoms (75%). Anxiety, depression, behavioral changes, psychotic symptoms, motor dysfunction and cognitive deterioration paralleled the severity of dementia, increasing their frequency from mild to severe dementia. The most important sleep disorders were irregular sleep-wake pattern (67%) and insomnia (47%). Disorientation (90%) and drug administration (88%) appeared to be the most important factors in causing sleep disorders in dementia. Disorientation, agitation and motor disorders were slightly more frequent in patients with APOE-4/4, while anxiety and sleep disorders appeared more frequently in APOE-3/4. Behavioral changes and psychotic symptoms did not show any clear association with specific APOE subtypes. In conclusion, our results suggest that noncognitive symptoms are very important clinical events in the disease progression and in decision making for therapeutic intervention and institutionalization. Furthermore, it is likely that some brain dysfunctions leading to particular clinical symptoms might be associated with specific AD genotypes.