Pharmacogenetic studies in Alzheimer disease

INTRODUCTION

Alzheimer disease (AD) is the most common cause of dementia and is considered one of the main causes of disability and dependence affecting quality of life in elderly people and their families. Current pharmacological treatment includes acetylcholinesterase inhibitors (donepezil, galantamine, rivastigmine) and memantine; however, only one-third of patients respond to treatment. Genetic factors have been shown to play a role in this inter-individual variability in drug response.

DEVELOPMENT

We review pharmacogenetic reports of AD-modifying drugs, the pharmacogenetic biomarkers included, and the phenotypes evaluated. We also discuss relevant methodological considerations for the design of pharmacogenetic studies into AD. A total of 33 pharmacogenetic reports were found; the majority of these focused on the variability in response to and metabolism of donepezil. Most of the patients included were from Caucasian populations, although some studies also include Korean, Indian, and Brazilian patients. CYP2D6 and APOE are the most frequently studied biomarkers. The associations proposed are controversial.

CONCLUSIONS

Potential pharmacogenetic biomarkers for AD have been identified; however, it is still necessary to conduct further research into other populations and to identify new biomarkers. This information could assist in predicting patient response to these drugs and contribute to better treatment decision-making in a context as complex as aging.

Role of morphology in the performance of LiFe0.5Mn1.5O4 spinel cathodes for lithium-ion batteries

Spinel oxides with composition LiMn2-xMxO4 (M, a transition metal) are intensively studied due to their remarkable electrochemical properties. This study deals with cathode materials based on the lithium iron manganese oxide LiFe0.5Mn1.5O4 synthesized by different methods (sol-gel, in solution and hydrothermal) in order to obtain samples with various morphologies. SEM results show microspheres, composed of nanosized/submicrometer-sized subunits, microrods with a less porous surface, and finally nanoparticles that form micro-sized aggregates. The samples obtained by both solution and hydrothermal methods provided the best electrochemical behavior. In all cases, the coulombic efficiency is around 90%, and it remains constant during the tested cycles. Specific capacities remain stable between 95% and 98% of capacity retention after series of cycles in samples formed by microspheres or micro-size aggregates. These values are notably higher than those obtained for the samples with particles of heterogeneous size (49%). A LiMn1.5Fe0.5O4/Li2MnO3 composite has been prepared by the solvothermal technique in order to increase its capacity and energy density. These cells show a good cyclability at different current densities. All cells based on these LiFe0.5Mn1.5O4 cathodes recover their discharge capacity when the current density returns to C/10.

Thiol-disulfide proteins of stallion epididymal spermatozoa

Thiol groups of cysteine residues represent redox centers involved in multiple biological functions. It has been postulated that changes in the redox status of mammalian epididymal spermatozoa contribute to the sperm maturation process. The present work shows the thiol-disulfide protein profile of stallion epididymal spermatozoa achieved by two-dimension electrophoresis and MALDI-TOF/TOF mass spectrometry of proteins labeled with a thiol-reactive fluorescent tag, monobromobimane. Our results have shown the formation of disulfide bonds in several sperm protein fractions during the epididymal maturation process. The majority of the oxidized thiol sperm proteins identified correspond to structural molecules of the flagellum (as the outer dense fiber-1 protein - ODF1), followed by glycolytic enzymes (as glyceraldehyde-3-phosphate dehydrogenase spermatogenic), antioxidant protectors (as glutathione S-transferase and phospholipid hydroperoxide glutathione peroxidase - PHGPx). The magnitude of the thiol oxidation differs between proteins, and was more drastic in polypeptides with molecular weights of up to 33kDa, identified as ODF1 and PHGPx. A kinase anchor protein, a voltage-dependent anion channel protein and a zona pellucida-binding protein were also found in the polypeptide samples that contained oxidized SH groups. These proteins may be modified or controlled by the mechanisms involved in the cysteine-redox changes, corroborating the belief that a correct degree of protein oxidation is required for the stabilization of sperm structure, protection against oxidative damage, induction of progressive sperm motility and fertilization.

Critical assessment of OmpF channel selectivity: merging information from different experimental protocols

The ion selectivity of a channel can be quantified in several ways by using different experimental protocols. A wide, mesoscopic channel, the OmpF porin of the outer membrane of E. coli, serves as a case study for comparing and analysing several measures of the channel cation-anion permeability in chlorides of alkali metals (LiCl, NaCl, KCl, CsCl). We show how different insights can be gained and integrated to rationalize the global image of channel selectivity. To this end, reversal potential, channel conductance and bi-ionic potential (two different salts with a common anion on each side of the channel but with the same concentration) experiments are discussed in light of an electrodiffusion model based on the Poisson-Nernst-Planck formalism. Measurements and calculations based on the atomic crystal structure of the channel show that each protocol displays a particular balance between the different sources of selectivity.

Nuclear status of immature and mature stallion spermatozoa

'The highly packed chromatin of mature spermatozoa results from replacement of somatic-like histones by highly basic arginine- and cysteine-rich protamines during spermatogenesis, with additional conformational changes in chromatin structure during epididymal transit. The objective of the present study was to compare the nuclear characteristics of immature and mature epididymal stallion spermatozoa, using a variety of experimental approaches. Resistance to in vitro decondensation of chromatin, following exposure to SDS-DTT and alkaline thioglycolate, increased significantly in mature spermatozoa. Evaluation of the thiol-disulfide status (monobromobimane labeling) demonstrated that immature cells obtained from ductulli efferentes contained mostly thiol groups, whereas these groups were oxidized in mature cells collected from the cauda epididymidis. Based on atomic absorption spectrophotometry, maturation of stallion spermatozoa was accompanied by a 60% reduction in the Zn(2+) content of sperm cells, concomitant with increased concentrations of this ion in epididymal fluid. Furthermore, the degree of disulfide bonding was inversely correlated with susceptibility of chromatin to acid denaturation (SCSA). Collectively, these data were consistent with the hypothesis that maturation of stallion spermatozoa involves oxidation of sulphydryl groups to form intra- and intermolecular disulfide links between adjacent protamines, with loss of zinc as an integral feature. These changes endow mechanical and chemical resistance to the nucleus, ensuring efficient transmission of the paternal genome at fertilization.

Psychosocial factors associated with cancer behavioural risk in relatives of cancer patients

The European Code against Cancer includes some primary cancer prevention behaviours, which can be studied in the framework of psychosocial models of human behaviour as the ASE model (attitude-social influence-efficacy model). The objective of this study was to detect the factors that better explain cancer behavioural risk in relatives of cancer patients. A convenience sample of 3031 people was selected in primary care centres. A three-step multivariate analysis was carried out by means of a multiple linear regression, introducing cancer behavioural risk as the dependent variable and the following covariables: psychosocial factors in the ASE model, sociodemographic variables and the family history of cancer. At least five difficulties and four needs were perceived in following the preventive advice by 25% of patients. The main difficulties were tobacco and alcohol addiction and the demands of a social life. Principal needs were access to cessation programmes, family support, and being controlled and pressured by health workers. The highest risk profile is to be a young man with a low sociocultural level. The ASE determinants were the best predictors of cancer behavioural risk, so programmes that forget these predictors may not achieve any impact and may waste resources.

Physical characteristics and chemical composition of Greater Rhea (Rhea americana) eggs from wild and captive populations

1. Eggs from wild and captive populations of Greater Rhea (Rhea americana) were studied to determine their physical and chemical characteristics. 2. Significant differences were found among populations in almost all chemical parameters studied, whereas within physical parameters only shell weight (as a proportion of the entire egg) and density showed differences. 3. Eggs from wild populations had the highest protein and linolenic acid and the lowest total lipid contents, while cholesterol levels of these eggs and of those from the largest captive area were the lowest.

Central role of the observable electric potential in transport equations

Nonequilibrium systems are usually studied in the framework of transport equations that involve the true electric potential (TEP), a nonobservable variable. Nevertheless another electric potential, the observable electric potential (OEP), may be defined to construct a useful set of transport equations. In this paper several basic characteristics of the OEP are deduced and emphasized: (i) the OEP distribution depends on thermodynamic state of the solution, (ii) the observable equations have a reference value for all other transport equations, (iii) the bridge that connects the OEP with a certain TEP is usually defined by the ion activity coefficient, (iv) the electric charge density is a nonobservable variable, and (v) the OEP formulation constitutes a natural model for studying the fluxes in membrane systems.

[Olanzapine efficacy in the treatment of cocaine abuse in methadone maintenance patients. Interaction with plasma levels]

INTRODUCTION

The aim of this study was to evaluate the efficacy of the treatment with antipsychotic olanzapine in cocaine abuse methadone patients. The decrease or interruption of cocaine consume as well as the possible pharmacokinetic interaction between olanzapine and methadone were studied.

MATERIAL AND METHODS

Patients (n= 21) include in a methadone maintenance program (14 months), with DSM-IV criteria for opioid and cocaine dependence and without schizophrenic diagnostic, were treated with olanzapine 5 to 10 mg/day. The therapeutic outcomes were assessed by personal interviews, cocaine consumption, changes of consumption patrons (via of administration) and secondary effects to olanzapine. Withdrawal symptoms were measured by means of the abbreviate version of the scale of Gossop. Cocaine used was measured by urine analysis (enzymoimmnuoassay). The possible pharmacokinetic interaction between olanzapine and methadone was measured in plasma before and during the treatment in 15 patients.

RESULTS

Olanzapine combined with methadone in cocaine abusers was well tolerated in an important proportion of patients. Moreover the consumption of cocaine was decreased or stopped in 53,2% of the patients. In addition, no withdrawal syndrome was observed in any patients. Furthermore the ratios of methadone plasma levels did not change in relation to the dose before and during the treatment, suggesting a lack of pharmacokinetic interaction between methadone and olanzapine.

CONCLUSIONS

In conclusion the results of this preliminary study, led us to advance that olanzapine could be a useful treatment for cocaine abuse at least in patients in a Methadone Maintenance Program, with the advantage of not to induce any pharmacokinetic interaction with methadone.

Changes in the plasma membrane proteins of stallion spermatozoa during maturation in the epididymis

The present paper reports modifications in the electrophoretic and cytochemical characteristics of mature and immature stallion spermatozoa. Some sperm surface glycoproteins (36, 32, 29, 21, 20, 18 kDa) detected in cauda epididymidis spermatozoa, were either absent or present in a very low relative concentration in immature sperm cells. A major 14 kDa protein band, observed in sperm extracts obtained from ductus efferentes, progressively decreased along the epididymal ductus. The nature and distribution of carbohydrate residues on the sperm membrane, during epididymal maturation, was also studied by use of lectin probes. Some protein bands bound concanavalin A while others, as the 36, 32 and 20 kDa proteins, exhibited higher affinity for WGA lectin. The distribution and relative density of mannose-, galactose-, N-acetylglucosamine-, N-acetylgalactosamine-, fucose- and sialic acid-containing macromolecules showed a characteristic pattern depending on the sperm membrane domain and on its origin. Some sperm surface domains displayed affinity for more than one lectin, indicating a diversity in their exposed carbohydrate residues, whereas others bound only one or no lectin. The passage of spermatozoa through the epididymidis was accompanied by changes in the accessibility or abundance of lectin ligands. Some lectins (UEA, WGA, LPA) gave stronger reaction in mature spermatozoa, while others (RCA, WFH, PNA) stained better immature spermatozoa. This remodeling of sperm surface molecules is probably a consequence of interactions between spermatozoa and the epididymal secretions, and may reflect addition or adsorption of new molecules, space configurations changes or biochemical modifications of pre-existing compounds. Our results suggest that the distribution and density of terminal oligosaccharidic residues on the sperm plasma membrane have species-specific characteristics. These post testicular developmental changes may be of significance in the overall understanding of the stallion fertility.

Cytochemical and electrophoretic study of the stallion epididymal glycoproteins

It has been suggested that proteins produced in specific regions of the epididymis, mostly androgen dependent glycoproteins, are involved in the sperm maturation process. In the present work, the glycoconjugated distribution pattern and the electrophoretic characteristics of the stallion epididymal proteins were examined using lectin probes. The identification in the luminal fluid of some new proteins, probably synthesized and secreted by the epididymis, is an important initial step to investigate their interaction with the stallion sperm membrane. The binding of FITC-lectins (ConA, WGA, LPA, UEA, RCA, HPA) confirmed the presence of macromolecules containing carbohydrate residues in the epithelial cells with a distribution and relative density that was dependent on the epididymal region analyzed. The epithelium displayed affinity for more than one lectin, indicating diversity in the exposed sugar residues. The electrophoretic pattern of proteins obtained from ductus efferentes, corpus and cauda epididymis differed not only from those of the homologous blood serum, but also among the different epididymal regions. The most prominent bands correspond to 66, 55, 45 and 14 kDa proteins, present in different relative concentrations, in the three analyzed regions. A major band of 36 kDa was observed in the cauda epididymis region. The relative concentrations of protein bands of Mw 45, 36, 32, 20 and 18 kDa were significantly increased towards the distal regions of the ductus. The proteins of Mw 66, 55 and 14 kDa showed a relative higher concentration in the efferent ducts, decreasing to 25-30% in the cauda epididymal regions. The Mw 70, 66, 55, 45, 36, 32, 29, 23, 21, 18 and 14 kDa protein bands gave positive PAS reaction indicating that it corresponds to glycoproteins. Mannose residues were detected in the 70, 66, 55, 45, 36 and 32 kDa proteins. WGA-FITC binds to protein bands of Mw 70, 55, 45, 36, 32, 29, 25 and 24 kDa, suggesting the presence of N-linked glycoproteins. However, based on the resistance to the neuraminidase treatment, we suggest that the stallion epididymis contains both O- and N-glycoconjugates, probably in the N-acetyl O-diacetyl form. Although sperm maturation is an androgen-dependent process, no striking differences were detected in the SDS-PAGE obtained from animals in breeding and non-breeding seasons.

Relationships between volatile production, fruit quality, and sensory evaluation in Granny Smith apples stored in different controlled-atmosphere treatments by means of multivariate analysis

Aroma compounds, quality parameters, and sensory evaluation of Granny Smith apples were analyzed after 3, 5, and 7 months of cold storage in three controlled-atmosphere (CA) treatments, in which oxygen and carbon dioxide were held at 1, 2, and 3%. During poststorage ripening, the apples were kept at 20 degrees C for 1, 5, and 10 days before analytical measurements were made. The highest volatile emission was obtained after 5 months of storage in all CA treatments, reaching its highest value when a low-oxygen CA (LO) was used. Ultralow-oxygen CA (ULO) showed the highest ability to maintain apple firmness. The correlation among analytical and sensory parameters suggests that ethyl 2-methylbutyrate, 1-butanol, pentyl acetate, and tert-butyl propionate are the aroma compounds with the highest influence in the sensorial score. Concerning CA treatments, LO and ULO appear to be very valuable technologies for maintaining the sensorial quality even after 7 months of storage.

[Fluoxetine (FX) efficacy in the treatment of cocaine dependence methadone maintenance patients. Interaction with plasma levels]

OBJECTIVES

The objective of this study was to assess the efficacy of fluoxetine (FX) treatment in cocaine dependent methadone (MTD) maintenance patients, to assess decrease or interruption of cocaine use and pharmacokinetic interaction between fluoxetine an methadone plasma levels.

MATERIAL AND METHODS

The sample was composed of 11 patients with DSM IV criteria for opioid and cocaine dependence. We added Fluoxetine (20 mg per day) during 9 weeks in Majadahonda Drug Program. All patients were in methadone program a mean of 7.5 months. We made a psychiatry interview and the baseline severity of the mood disorder was assessed with the Clinical Global Impression ICG for therapeutic improvement. Cocaine use and fluoxetine treatment was measured in urine analysis and pharmacokinetic interaction between FX-MTD were measured with plasma levels of methadone.

RESULTS

Fluoxetine was well tolerated combined with methadone. FX-MTD interaction didn't occur, resulting in no increased of MTD plasma level to dose before and after fluoxetine treatment. After fluoxetine treatment decreased cocaine use, changed cocaine tract from injected to smoked and improvement depressive symptoms.

Residue levels of ethoxyquin, imazalil, and iprodione in pears under cold-storage conditions

A gas chromatographic method is presented for the simultaneous determination of the antiscald ethoxyquin and the fungicides imazalil and iprodione in peel and pulp of Blanquilla pears. Fruits were cold-stored in commercial chambers in normal atmosphere and in controlled atmosphere with low oxygen content (oxygen and carbon dioxide were held at 2.5% and 1.5%, respectively). The method uses gas-liquid chromatography (GLC) with an alkaline flame ionization detector (detector of N-P, NPD) and allows the detection of the mentioned compounds to minimum levels of 0.08-0.12 mg/kg in fresh fruit. With this system the evolution of residues in fruit was monitored throughout the period of cold storage. In the surveys carried out the residue levels of these compounds were found to be below the limits allowed by the legislation of European Union. For the three studied products residues in pulp are lower and disappear more quickly than in peel.

Arsenite alters heme synthesis in long-term cultures of adult rat hepatocytes

Arsenite (As[III]) effects on the intermediate steps of heme biosynthesis were studied in adult rat hepatocytes seeded on a feeder layer of 3T3 cells (3T3-hepatocytes) and maintained for 2 weeks with culture medium non-supplemented or supplemented with 150 microM 5-aminolevulinic acid (ALA). The activities of the intracellular enzymes porphobilinogen deaminase (PBG-D), uroporphyrinogen III synthase (UROIII-S), and uroporphyrinogen III decarboxylase (URO-D), and the intermediary uroporphyrins (URO), coproporphyrins (COPRO) and protoporphyrin IX (PROTO) were determined in these cultures. The 3T3-hepatocytes maintained the activities of PBG-D, UROIII-S and URO-D during 2 weeks and ALA addition to the culture medium increased PBG-D (2-3-fold) and UROIII-S (50%) activities and porphyrin production, which accumulated as PROTO. Exposure to 3.9 microM As(III) inhibited UROIII-S activity (down to 34%), and PBG-D and URO-D activities to a lower extent; these effects were magnified by ALA supplementation. As(III) also produced an intracellular accumulation and a decreased excretion of PROTO, and a 31% reduction of the COPRO/URO ratio in the culture medium. Additionally, As(III) caused cytoplasmic vacuolization and lipid accumulation. Our results show that As(III) exposure selectively inhibits several intermediary enzymes of heme metabolism and affects the intra- and extracellular content of porphyrins and their ratio in the culture medium. They also confirm that 3T3-hepatocytes are a suitable in vitro model to study hepatic heme metabolism and its alterations by hepatotoxic chemicals.

[The incidence of lesions associated with prostatic biopsy and its effect on the serum concentration of the prostate-specific antigen]

OBJECTIVE

To analyze the incidence of pathoanatomical lesions seen in systematic prostate biopsies and to evaluate their influence on PSA serum levels.

MATERIAL AND METHODS

495 consecutive prostate biopsies, indicated by a suspicion digital rectal examination in 194 patients (39.2%) and raised serum PSA in 301 (60.8%), were evaluated. Biopsy was performed by sextant and hypoechoic nodes, and PSA serum measurements by dual monoclonal antibody radioimmunoassay, Tandem PSA.

RESULTS

Cancer was diagnosed in 42.6% biopsies and BPH in 67.4%; additionally, other associated lesions were detected in 74.6% cases, the most frequent ones being chronic prostatitis (47.3%), glandular atrophy (35.9%) and acute prostatitis (23%). All lesions were significantly related to the primary BPH diagnosis in 74.2% to 85% cases. High grade PIN (14.1%) was related to primary cancer diagnosis in 87.1% cases. The multivariate analysis showed that the main diagnosis (BPH vs cancer) was the only variable that had a significant influence on PSA serum levels. When BPH patients were considered separately, the only variable with significant influence on PSA serum levels was the prostatic volume. The univariate analysis showed a nonsignificant increase in association with acute prostatitis and high grade PIN, and a decrease in association with chronic prostatitis.

CONCLUSIONS

BPH or cancer associated damage is very frequent in prostatic biopsies. However, the only factors showing a significant contribution to PSA serum levels appear to be the presence or absence of cancer, or the prostatic volume when the main diagnosis is BPH.

Influence of Different Oxygen and Carbon Dioxide Concentrations during Storage on Production of Volatile Compounds by Starking Delicious Apples

Starking Delicious apples were cold-stored in semicommercial chambers in normal atmosphere and in different controlled atmospheres in which oxygen and carbon dioxide were held at 1%, 2%, and 3% for 3, 5, and 7 months. After storage, fruit was kept at ambient temperature (20 degrees C) for 1, 5, and 10 days. The volatile emission was collected and analyzed. After all storage periods and conditions, the total aromatic volatile emission was higher than at commercial harvest. The highest emission of volatile components was obtained after 5 months of storage, in which controlled-atmosphere conditions gave a lower concentration than normal cold storage. Esters were the main volatiles detected (>98%). Acetate ester concentrations after all storage periods assayed were higher at 3% and 2% O(2)/CO(2). The components that contributed most to the characteristic aroma of Starking Delicious were ethyl 2-methylbutyrate, ethyl butyrate, and ethyl hexanoate. Their concentrations were higher after 5 months of storage and also during poststorage at ambient temperature (20 degrees C).

Regional differentiation of the blood-epididymis barrier in stallion (Equus caballus)

The occurrence, localization and ultrastructural characteristics of a blood-tissue barrier throughout the stallion proximal seminal excurrent duct system were studied by the exclusion of electron-dense tracers and freeze-fracture techniques. Striking differences were observed in the distribution of lanthanum tracer and in the geometrical organization of the zonulae occludentes along the ductus efferentes, epididymides and vas deferens. The zonulae occludentes domain, the principal structural component of the blood-epididymis barrier, differed in permeability, width and strand numbers along the ductus. The flow of tracer was not impeded by the vascular endothelium, the peritubular myoid layer or other surface membrane specialization. The tight junctions of the ductuli efferentes are poorly developed but unlike those of rats, guinea pigs or man they are not associated with gap junctions. The result of the tracer experiments and the low number of tight junctional strands in the ductuli efferentes suggests that the barrier of the ductuli efferentes corresponds to the 'leaky type'. In the epididymis the zonulae occludentes are well developed throughout the duct. The greatest number of strands, especially in the cauda epididymidis regions, correlates well with a decreased junctional permeability in this area. Another evidence for the existence of the stallion blood-epididymis barrier are the differences in the proteins electrophoretic profiles between blood plasma as compared with the fluid inside the seminal ductus. This junctional complexes contribute to create a highly defined luminal fluid microenvironment that ensures the sperm maturation and survival.

Effect of arsenite on urea production by long-term cultures of adult rat hepatocytes

Urea cycle is a hepatic metabolic pathway involving five enzymes and several intermediary metabolites and can be altered by different chemicals. To investigate the effect of arsenic, an ubiquitous hepatotoxic agent, on urea production we exposed long-term cultures of adult rat hepatocytes, which produce urea, to 1.33 and 6.67 microM arsenite for 2 weeks. In cultures exposed to 6.67 microM, urea production decreased 60-70% and cellular arginase activity decreased 30, 70 and 85% after 4, 7 and 14 days of exposure, respectively. The arginase activity released to the medium increased significantly after 4, 7 and 14 days, with a maximum value after 7 days of exposure that was 27-fold higher than that of the untreated controls. The total arginase activity also decreased 35, 52 and 82% after 4, 7 and 14 days of exposure and protein content decreased 57 and 65% after 7 and 14 days of exposure, respectively. Exposure to 6.67 microM arsenite also produced accumulation of intracytoplasmic lipid droplets, vacuolizations and enlargement of the intercellular spaces. On the other hand, exposure of hepatocytes to 1.33 microM arsenite caused an initial decrease of 20% in urea production, did not change cellular, released and total arginase activity and cellular protein content and produced accumulation of intracytoplasmic lipid droplets. These results show that long-term exposure of cultured rat hepatocytes to 6.67 microM arsenite decreases urea production, cellular and total arginase activity and protein content and increases the release of arginase into the culture medium. These alterations could be useful markers of hepatotoxicity in in vitro assays.

Porphyrin production and excretion by long-term cultures of adult rat hepatocytes and effect of lead exposure

Porphyrin production and excretion and the effects of lead exposure were studied in long-term cultures of adult rat hepatocytes cultured on a feeder layer of 3T3 cells after addition of 5-aminolevulinic acid. Porphyrin excretion into the culture medium showed an irregular profile during the first 10 days, with a maximum increase of 50% at day 4 and at day 10 a value similar to that of day 1. Thereafter, porphyrin excretion decreased progressively to 18% of the initial value after 4 weeks. The cellular porphyrin content, after 7 and 28 days in culture, reached values 3.8 and 2.4-fold higher than the corresponding day 1 value. The exposure to 0.5 and 2.4 microM Pb2+ for up to 28 days produced a biphasic effect on porphyrin excretion. Firstly, there was a progressive decrease up to 81% during the first 6 days of lead exposure and, secondly, this effect was followed by an increase reaching control values at day 15 and of up to 6.7-fold after 22 days of exposure to 2.4 microM Pb2+. Similar changes were observed in cellular porphyrin content. The exposure to 0.5 and 2.4 microM Pb2+ for 2 and 4 weeks also produced morphological alterations and release of cytoplasmic enzymes. Our results show that hepatocytes cultured on 3T3 cells produce and excrete porphyrins for 28 days and that exposure for 4 weeks to micromolar lead concentrations alters these functions and cell morphology and produces cytotoxic effects which are better evaluated by monitoring alterations in porphyrin excretion than by enzyme leakage. They also suggest that this culture system is a useful model for assessing the toxic effects of xenobiotics on the biosynthesis of heme by liver cells.

Knowledge of the European Code against Cancer in sixth-form pupils and teachers in Asturias (Spain)

Cancer is the second major cause of death in Spain and in most industrialized countries. It is also the main cause of premature death. The objective of this study was to evaluate what is known and practiced of the European Code against Cancer by students and teachers of the final course of secondary education in Asturias (Spain). Two questionnaires (the official one given by the European Code against Cancer and another, designed by us) were given to a representative sample of 695 students and 160 teachers. The mean score of knowledge for teachers and pupils, respectively, was 6.41 and 5.05, out of a possible maximum of 16 points. This difference was statistically significant (Student's t-test = 6.63; P > 0.0001). A relationship was also found in females between knowledge and practice in relation to food intake, tobacco and alcohol consumption, and cancer. Our results demonstrate a lack of knowledge and practice of the Code, which places at risk the main objective of the Europe against Cancer Programme to reduce cancer mortality by 15% by the year 2000. In our opinion more informational-educational programmes are therefore necessary.

[Molecular detection of chromosome Y DNA sequences in patients with Turner's syndrome]

The presence of Y-chromosome material in the genome of phenotypic females has been associated with an increased risk of developing gonadal tumors. To assess whether DNA sequences of the Y-chromosome are present in the genome of individuals with gonadal dysgenesis and clinical features of Turner's syndrome, we have studied three patients with 45, X/46, X, + mar chromosome complement, and two Turner patients with 45, X/46, XY and 45, X karyotypes who served as positive and negative controls, respectively. Molecular detection of Y-DNA sequences was done by DNA-DNA hybridization using the specific probes pY97 and pDP1007 as well as by polimerase chain reaction. The results revealed that the marker chromosome of one of the patients contained DNA sequences from the centromeric region of the Y-chromosome in a manner similar to that found in the 45, X/46, XY patient and in the male control; the gene ZFY was negative in this patient, and was probably lost when the ring chromosome was formed. In contrast, the ring chromosomes of the other two patients did not exhibit the presence of Y-chromosome material. The results were interpreted as demonstrating the Y-chromosome origin of the ring marker in one patient with gonadal dysgenesis, and suggest an X-chromosome origin of the ring markers in the other two patients. These data further underline the relevance of practicing molecular studies in these disorders which may help to determine appropriate therapeutic strategies.

Inhibition of lipid synthesis and secretion in long-term cultures of adult rat hepatocytes by alpha-asarone

In this work we studied the effect of alpha-asarone, a hypolipidemic active principle of Guatteria gaumeri Greenman, on hepatic lipid metabolism using adult rat hepatocytes cultured on a feeder layer of 3T3 cells. These cultures synthesize and secrete for at least two weeks various lipids from [14C]-acetic and [14C]-oleic acid. Exposure for one or two weeks to 10 micrograms/ml of alpha-asarone decreased the secretion of various lipids to the culture medium; triacylglycerol secretion was inhibited by 80-97%, phospholipid secretion by 70-87%, cholesterol by 64-70%, and cholesterol esters by 50-92%. The incorporation of [14C]-acetic acid into cellular lipids decreased by 30-81% and that of [14C]-oleic acid into phospholipids by 25-47% whereas the incorporation of [14C]-oleic acid into triglycerides and cholesterol esters increased 3.2 fold and by 28-36%, respectively. Similarly, the activities of glycerol-3-phosphate dehydrogenase and malic enzyme, marker enzymes of glycerolipid and fatty acid synthesis, decreased by 22-50% and 30-76%, respectively. Our results show that the exposure of the 3T3-hepatocyte cultures to micromolar concentrations of alpha-asarone significantly inhibits lipid secretion and probably lipid synthesis. They also suggest that at least part of the hypolipidemic effect could be due to a decrease in the secretion of lipids (i.e., lipoproteins) by the hepatocytes.

alpha-Asarone toxicity in long-term cultures of adult rat hepatocytes

In this work we studied the toxic effects of alpha-asarone, a hypolipidemic active principle of Guatteria gaumeri Greenman, on long-term cultures of adult rat hepatocytes cultivated on a feeder layer of 3T3 cells. The exposure for one and two weeks to alpha-asarone (1-50 micrograms/ml) produced intracytoplasmic lipid droplets and at higher concentrations (25-50 micrograms/ml) retraction of the hepatocyte cords and cell detachment. Ultrastructurally, the treated cultures (10 micrograms/ml) showed enlargement and vacuolization of the mitochondria in addition to lipid droplets. The triacylglycerol content increased up to 2.3-fold in the cultures treated for one week with 50 micrograms/ml, whereas the protein content per culture, a rough estimate of cell number and viability, decreased by up to 53% in the cultures treated for two weeks with 50 micrograms/ml. The synthesis and secretion of proteins, measured by the incorporation of [3H]-leucine into cellular and secreted macromolecules, decreased also in the cultures exposed. After one and two week exposure to 50 micrograms/ml of alpha-asarone, the secretion of labeled proteins decreased by 53 and 67%, respectively, whereas the synthesis of cellular and total proteins decreased by 48-67%, respectively. The secretion of proteins was the most sensitive parameter of alpha-asarone toxicity. The mean inhibitory dose (ID50), i.e, that producing 50% inhibition in the incorporation of the labeled precursor, was 22.12 and 5.04 micrograms/ml after one and two weeks exposure, respectively. Our results show that long-term exposure to micromolar concentrations of alpha-asarone produces morphologic and ultrastructural alterations, triacylglycerol accumulation (fatty liver), and inhibition of protein synthesis and secretion.(ABSTRACT TRUNCATED AT 250 WORDS)

Effects of cyproterone acetate on the ultrastructure of the human epididymis

The effects of cyproterone acetate (CPA), an antiandrogenic steroid, on the ultrastructure of the epithelial cells of the human epididymis were studied. Alterations in the cell size, in the cytoplasmic and surface characteristics, and in the morphology of different organelles are described. The different ultrastructural changes observed suggest that the absorptive and secretory functions of the principal cells are impaired following the CPA treatment. By contrast, with the drastic response of the principal cells of the ductuli efferentes and caput epididymidis, the epithelial cells of the cauda epididymidis appeared less affected. The suggestion of a differential androgen dependence among the different regions of this androgen target organ, as well as between the major cell-types of the epididymal epithelium, is briefly discussed.

True and apparent oxygen permeabilities of contact lenses

We studied the passage of oxygen through some commercially available contact lenses. Oxygen diffusion coefficients were determined by the time-lag method and a 201T Redher permeometer was used to measure the oxygen permeability and transmissibility by the polarographic method. The measurements were carried out at room temperature with 0.09% sodium chloride physiologic solution. The following types of lenses were tested: (1) 12 lenses of cellulose acetate butyrate (CAB) of a mean thickness of 0.194 mm (observed Dk approximately 6.3 barrers) (1 barrier is equivalent to 10(-11) cm3 of O2 (STP).cm2/cm3.s.mm Hg). (2) 13 lenses of a cross-linked polyhydroxyethyl methacrylate (2-HEMA), manufactured by Lenticon and Bausch & Lomb, with 40 and 38.6% water content, respectively. The mean thicknesses were 0.160 and 0.148 mm, respectively (observed Dk approximately 12 to 13.5 barrers). (3) Finally 10 lenses of a copolymer of 2 HEMA with N-2-vinylpyrrolidone (2-HEMA/VP), manufactured by Bausch & Lomb under the name Hydrocurve II, with 55% water content and a mean thickness of 0.138 mm (observed Dk approximately 24.5 barrers). For a given lens thickness, the transmissibility and permeability of lenses whose main material is 2-HEMA are found to be equivalent. This fact suggests the use of such material as a standard in the study of diffusion processes in contact lenses of low oxygen permeability (Dk approximately 12 to 13.5 barrers). We studied the boundary layer effects and found significant discrepancies between true and apparent oxygen permeabilities. The apparent transmissibility decreased with increasing lens thickness, this effect being more apparent for lenses with low water content. Oxygen permeability is found to be exponentially dependent on water content rather than on the chemical composition of the hydrogel.

Synthesis and secretion of lipids by long-term cultures of female rat hepatocytes

The objective of this work was to characterize lipid metabolism in long-term cultures of adult rat hepatocytes from female rats and explore the potential use of this culture system to study the effect of hormones, drugs and toxic chemicals on it. Hepatocytes, seeded on a feeder layer of 3T3 cells, maintained for 2 weeks their typical morphology. The cultures were able to take up [14C]acetic and [14C]oleic acid from the culture medium and incorporate them into lipids. The synthesis and secretion of lipids by [14C]acetic acid-labeled cultures had a maximum value after 11 and 13 days in culture. Triacylglycerols were the main lipidic species synthesized and secreted by hepatocytes (up to 67% of the total lipids); they also synthesized and secreted phospholipids, cholesterol and cholesterol esters from [14C]acetic acid. Similarly, [14C]oleic acid-labeled cultures synthesized and secreted mostly triacylglycerols (up to 60-70% of the total lipids), but they were also able to incorporate the labeled precursor into both cellular and secreted phospholipids and cholesterol esters. The activity of glycerol-phosphate-dehydrogenase, marker enzyme of glycerolipid synthesis, decreased slightly during the culture time whereas the activity of malic enzyme, marker of fatty acid synthesis, increased. Our results show that long-term cultures of female rat hepatocytes are able to synthesize and secrete several lipids, specially triacylglycerols, from both [14C]acetic and [14C]oleic acid for at least 2 weeks and that they maintain enzyme activities related with the synthetic pathways of glycerolipids and fatty acids.(ABSTRACT TRUNCATED AT 250 WORDS)

Distribution of filipin-sterol complexes in the plasma membrane of stallion spermatozoa during the epididymal maturation process

The presence and distribution of cholesterol in mature and immature epididymal spermatozoa was analyzed using filipin as a cytochemical tool in freeze-fracture replicas and thin section preparations. The polyenic-antibiotic filipin formed complexes with 3, beta -OH sterols, producing characteristic protrusions, or pits, that were heterogeneously distributed in the plasma membrane of stallion spermatozoa, revealing a specific organization in a functionally specialized area of the gamete. The acrosomal region of the sperm head presented a significantly higher density of filipin sterol complexes than the postacrosomal region, which was usually free of these complexes. The plasma membrane of the flagellum also showed filipin sterol complexes randomly distributed in freeze-fracture replicas. The strong filipin labeling observed in the membrane of spermatozoa obtained from the caput region of the epididymis decreased significantly during epididymal passage. The significance of these changes is not completely understood, but they might contribute to establishing the molecular organization necessary for sperm transit and storage in the epididymis as well as to development of motile spermatozoa that are able to fertilize the oocyte and induce normal embryonic development.

[Public health problems in old age]

The health problems affecting the elderly in Spain over the last few years of the twentieth century have been complied and analyzed. Of outstanding important are the problems of a social nature, in the form of mandatory retirement, at time early retirement, insufficient economic means and the lack of esteem and love from which the elderly suffer. The aid of Health Education in different target groups to attempt to achieve changes in the amount of knowledge and the attitudes towards old age and death, which will lead to more kindly social conduct and behavior with regard to the elderly, is proposed.

[Comparative study of two Arcon articulators with different transference face bows]

This paper is about the possible influence that the use of two different face archs on the transference of the upper model, should have in the later regulation of the semiadjustable articulator Arcon type.

Triglyceride accumulation in long-term cultures of adult rat hepatocytes by chronic exposure to Aroclor 1254

The effect of chronic exposure to micromolar concentrations of Aroclor 1254 (Aro) on the hepatic lipid metabolism was studied in long-term cultures of adult rat hepatocytes. Hepatocytes were cocultivated with mitomycin C-treated 3T3 cells and exposed for 2 wk to Aroclor 1254 concentrations ranging from 0.01 to 20 micrograms/ml. The Aro-exposed cultures showed intracytoplasmic lipid droplets and a maximum increase of 55% in the triglyceride (TG) content and of 4.4-fold in the cytochrome P-450 content. Labeling studies with [14C]acetic and [14C]oleic acid showed no changes in the uptake of fatty acid and TG precursors by the Aro-treated cultures; the synthesis of cellular lipids from [14C]acetic acid was slightly inhibited by Aroclor 1254, but that from [14C]oleic acid was increased, specially for TG (37%). The secretion of total lipids and TG was 2.1- and 2.7-fold lower, respectively, in the cultures treated with 20 micrograms/ml of Aroclor 1254, resulting in an increase of 1.9-fold in the intracellular content of TG. The synthesis of cellular proteins labeled with [3H]leucine was unchanged in the Aro-treated cultures, but the secretion of exportable proteins was 1.7-fold lower in the cultures treated with 20 micrograms/ml of Aroclor 1254. Our results showed that long-term exposure to in vivo relevant concentrations of Aroclor 1254 produced morphological and biochemical changes in cultured hepatocytes, like those described in vivo, and intracellular TG accumulation due mostly to impaired secretion of TG by the hepatocytes. Our results also suggest that this culture system could be useful for the screening of toxic agents producing fatty liver and the study of the involved mechanism(s).

Cytochemical analysis of the anionic sites on the membrane of the stallion spermatozoa during the epididymal transit

The structure, relative density, and distribution of anionic sites on the surface of epididymal and ejaculated spermatozoa were studied using polycationic ferritin (CF), colloidal iron hydroxide (CIH), various enzymatic treatments, methylation, and de-acetylation. Macro-molecules containing sugar residues, probably sialic acid, are part of the sperm membrane and show a characteristic distribution and density that is dependent of the sperm region and of its origin. Unlike the spermatozoa of other eutheria examined, the exposure of the stallion spermatozoa to neuraminidase treatment did not produce significant changes in the density of the negative charge of the sperm surface. The ability of purified neuraminidase to act only after saponification suggests that sialic acid may be present in the acetylated form. When CIH was used it is seen that the density of the negative charge is rather uniform within a particular segment of the spermatozoa and abruptly changes at the junction of morphologically distinct segments (Between the acrosomal and post acrosomal region of the sperm head and between the post acrosomal region and middle piece of the flagellum). The acrosome presented more negative groups dissociated at pH 1.8 than the postacrosomal region. A greater concentration of anionic sites over the flagellum was also observed when CIH and CF were used. This asymmetry probably represents different domains that may be related to specific functions. The cytochemical observations and the cellular electrophoretic mobility measurements did not show striking differences on the negative charge of sperm obtained from different regions of epididymis and ejaculates in contrast to previous results in other species. The spermatozoa collected from caput epididymidis bind CIH but not all population present equal response. In corpus and cauda region of epididymis the population displaying the capacity to bind CIH or CF significantly over the head and tail surface was the majority. This study corroborates that the distribution and density of terminal oligosaccharide residues on the sperm plasma membrane has species specific characteristics. The surface charge of the spermatozoa obtained either during the breeding or nonbreeding season, determined by measurements of cellular electrophoretic mobility and by the binding pattern of CIH and CF, does not show significant differences.

Ultrastructure of the lamina propria of the human ductuli efferentes and ductus epididymidis

The cellular and connective tissue constituents of the lamina propria of the ductuli efferentes and the ductus epididymidis of prepubescent, adult and senescent men were studied by means of electron microscopy. Layers of contractile cells showing features of smooth muscle cells, alternate with interstitial layers of connective tissue fibers. Additionally to collagenous fibers, in the interstitial layers three types of elastic system fibers, oxytalan, elaunin and elastic, were evident, differing by their varying amount of elastin. Oxytalan fibers, lacking the amorphous component elastin, were present in almost all intercellular spaces along the excurrent duct system, closely related to the contractile cells. They were the only type of elastic system fibers recognizable in the prepubescent epididymal lamina propria. However, in the adult and senescent men, elastin deposits were observed in the middle and outer layers of the lamina propria. In these cases the elaunin and elastic fibers appeared to increase with the gradual proximo-distal thickening of the subepithelial coat of contractile cells. In senescent men, only in few cases the epididymal lamina propria showed some alterations. It is suggested that these changes are not related to age but more likely to the state of individual testicular function. The functional significance of the special architecture of the epididymal lamina propria is discussed.