Method for analysis of polymer-supported organic compounds using mass spectrometry direct insertion

A new approach on the use of mass spectrometry direct-insertion and a quadrupole detector for analysis of organic compounds supported in solid phase has been developed. This is a simple and efficient method based on cleavage due to the thermal-instability of the benzylic group of most commercial resins. The cleavage of supported compounds takes place in the spectrometer as a consequence of the high temperature in the instrument's chamber. These compounds are detected using a similar fragmentation pattern and a molecular ion corresponding to the same compound obtained by traditional synthesis. Polymer degradation fragments do not interfere with the spectrum interpretation, because only a few peaks and low intensities are detected. We report here the identification of different types of compounds supported in Merrifield resin, such as bis-o-aminobenzamides and simple aromatic and aliphatic compounds, using this new approach.

[Juvenile myoclonic epilepsy in chromosome 6p12: clinical and genetic advances]

Amongst idiopathic generalized epilepsies, juvenile myoclonic epilepsy (JME) is the most common, accounting for 12% to 30% of all epilepsies in the Western world. Classic JME consists of awakening myoclonias, grand mal convulsions and EEG 4 to 6 Hz polyspike waves that appear in adolescence. Probands and affected family members do not have pyknoleptic 3Hz spike and wave absences. However, in 10 to 30% of patients, rare or spanioleptic polyspike wave absences appear. In 1988,1995,1996,we mapped classic JME to a 7 cM locus in chromosome 6p12 11, called EJM1, using families from Los Angeles and Belize. In 2001,we studied one large family from Belize and 21 new families from Los Angeles and Mexico Cities, aided by a BAC/PAC based physical map and 6 new dinucleotide repeats, to narrow EJM1 to an interval between D6S272 and D6S1573. In 2002, we found myoclonin, the putative gene for typical JME in 6p12. At the congress, we will reveal the identity of the myoclonin gene, its putative function and discuss the significance of this discovery in the JME population at large.

Homozygosity in Huntington's disease: new ethical dilemma caused by molecular diagnosis

Huntington's disease (HD) is a degenerative disorder of the central nervous system with autosomal dominant inheritance. Genetic counseling has always been difficult in this disorder with anguish, depression and denial being very common in both the patient and family members. The discovery of the causal gene has led to precise diagnostic procedures allowing homozygotes for the disease to be identified. Contrary to what occurs in some other autosomal dominant diseases, the course of the disease is not more severe in the homozygote than in the heterozygote. The present authors describe a family comparing two affected siblings: one is heterozygotic and the other homozygous for the HD mutation. They confirm that the age and symptoms of onset did not differ significantly between the subjects; however, the disease seemed to have a more severe progression in the heterozygote than in the homozygote. The authors discuss the ethical dilemma derived from the genetic counseling of a homozygotic patient, given the fact that all his offspring will be affected. Letting the offspring know about their 100% probability of inheriting the disorder is equivalent to delivering a non-requested predictive test, while not informing them constitutes withholding crucial information from the individual.

Clinical and genetic analysis of four Mexican families with spinocerebellar ataxia type 10

Spinocerebellar ataxia type 10 (SCA10) is an autosomal dominant disorder caused by expansion of an unstable ATTCT repeat. SCA10 has been described as a pure cerebellar syndrome accompanied by seizures and has been recognized only in families of Mexican origin. We describe clinical and molecular findings of 18 patients in four Mexican families with SCA10. Affected individuals had an average age at onset of 26.7 years (range 14-44 years) and ATTCT repeats ranging from 920 to 4,140 repeats. We could not detect significant anticipation or correlation between repeat size and age at onset, probably due to the small sample size. In addition to pure cerebellar ataxia and seizures, patients often showed soft pyramidal signs, ocular dyskinesia, cognitive impairment, and/or behavioral disturbances. Brain magnetic resonance imaging showed predominant cerebellar atrophy, and nerve conduction studies indicated polyneuropathy in 66% of patients. One family showed hepatic, cardiac, and hematological abnormalities in affected members. These findings suggest that a wide range of tissues may be affected in SCA10, including those outside of the cerebellum and cerebral cortex.

Expression of human apolipoprotein A-I/C-III/A-IV gene cluster in mice reduces atherogenesis in response to a high fat-high cholesterol diet

We have previously generated transgenic (Tg) mice expressing the human apolipoprotein (apo) A-I/C-III/A-IV gene cluster. This expression induced hyperlipidemia but reduced atherosclerotic lesions in genetically modified mice lacking apoE. Atherosclerosis is a multifactorial process and environmental factors such as diet play significant roles in its development. We examined here how an atherogenic diet influences the expression of the human genes and the characteristics of the Tg mice. Our results indicate that a high fat-high cholesterol diet up-regulates the intestinal expression of the three genes and the concentration of the three proteins in plasma. Cholesterol concentration was highly increased in the non-high density lipoprotein (HDL) fraction, and less, although significantly, in the HDL fraction. Tgs showed a 65% reduction in diet-induced aortic lesions compared with non-Tg mice. Atherogenic diet increases the expression of the genes encoding the scavenger receptor class B type I (SR-BI) and ATP binding cassette transporter 1 (ABCA1) proteins. As cholesterol efflux mediated by SR-BI or by ABCA1 was enhanced in Tg mice fed an atherogenic diet, we can hypothesize that increased reverse cholesterol transport is the basis of the protective mechanism observed in these animals. In conclusion, we present evidence that the expression of the human gene cluster in mice protects against atherogenesis in response to an atherogenic diet.

Expression of prolactin gene and secretion of prolactin by rat retinal capillary endothelial cells

PURPOSE

Prolactin fragments inhibit blood vessel formation, whereas anti-prolactin antibodies induce angiogenesis in the cornea. Endothelial cells from brain capillaries and the umbilical vein produce prolactin, and this study was undertaken to determine whether retinal capillary endothelial cells could be a source for prolactin in the eye.

METHODS

Primary cultures of rat retinal endothelial cells were investigated for the expression of prolactin mRNA by reverse transcription-polymerase chain reaction (RT-PCR) and Southern blot analysis and by in situ hybridization. The prolactin protein was analyzed by immunocytochemistry, enzyme-linked immunoabsorbent assay, Western blot analysis, and the Nb2-cell bioassay. The effect of prolactin and the 16-kDa prolactin fragment on retinal endothelial cell proliferation was investigated, and the expression of the cloned prolactin receptor was analyzed by RT-PCR and Southern blot analysis.

RESULTS

Retinal endothelial cells expressed prolactin mRNA and full-length 23-kDa prolactin. Prolactin was observed in the cytoplasm of cells and in their conditioned medium at levels 300 times those described in endothelial cells from other vessels and species. Exogenous 16-kDa prolactin inhibited rat retinal endothelial cell proliferation, whereas 23-kDa prolactin was inactive. No evidence was obtained for the expression of the cloned prolactin receptor in these cells, but the prolactin receptor was amplified in whole rat retina.

CONCLUSIONS

Endothelial cells from the microcirculation of rat retina produce and release prolactin. That the cloned prolactin receptor was not expressed in these cells argues against direct autocrine effects of prolactin. Possible paracrine effects are suggested by the expression of the prolactin receptor in retinal tissue.

Antioxidative and antiatherosclerotic effects of human apolipoprotein A-IV in apolipoprotein E-deficient mice

Mice expressing human apolipoprotein A-IV (apoA-IV) mainly in the intestine were obtained in an apolipoprotein E-deficient (apoE(0)) background (apoA-IV/E(0) mice). Quantification of aortic lesions and plasma lipid determination showed that compared with their control apoE(0) counterparts, the apoA-IV/E(0) mice are protected against atherosclerosis without an increase in HDL cholesterol. Because oxidized lipoproteins play an important role in atherogenesis, we tested whether the protection observed in these animals is accompanied by an in vivo reduction of the oxidation parameters. The lag time in the formation of conjugated dienes during copper-mediated oxidation, the aggregation state of LDL, and the presence of anti-oxidized LDL antibodies were measured. The presence of oxidized proteins in tissues and the presence of oxidation-specific epitopes in heart sections of atherosclerotic lesions were also analyzed. Except for lag time, the results showed that the oxidation parameters were reduced in the apoA-IV/E(0) mice compared with the apoE(0) mice. This suggests that human apoA-IV acts in vivo as an antioxidant. In addition, human apoA-IV accumulation was detected in the atherosclerotic lesions of apoA-IV/E(0) mice, suggesting that apoA-IV may inhibit oxidative damage to local tissues, thus decreasing the progression of atherosclerosis.

[The treatment and prognosis of sarcoidosis. Apropos 53]

OBJECTIVE

We retrospectively studied 53 cases of sarcoidosis which have been diagnosed at our service during de last 14 years. The criteria for starting therapy with corticosteroids and recurrences were analyzed.

METHOD

The patients mean (SD) age was 42 (15) years old (range 16-76) and the majority were female (72%). 15 patients (28.3%) received corticosteroids. The only differences with respect to patients not treated were the presence of respiratory symptoms (47% vs 18%; p = 0.04) and the abnormality of spirometric parameters (DLCO/VA p = 0.01; CV p = 0.002).

RESULTS

17 (32%) patients recurred. 14 (82%) of them required corticosteroids. This percentage was significantly greater than that of patients treated at first episode (82% vs 28%, p = 0.0002). All patients improved with treatment. The only difference with respect to patients without recurrences were to be treated at the first episode (53% vs 17%, p = 0.007).

Expression of human apolipoprotein A-I/C-III/A-IV gene cluster in mice induces hyperlipidemia but reduces atherogenesis

The apolipoprotein (apo)A-I/C-III/A-IV gene cluster is involved in lipid metabolism and atherosclerosis. Overexpression of apoC-III in mice causes hypertriglyceridemia and induces atherogenesis, whereas overexpression of apoA-I or apoA-IV increases cholesterol in plasma high density lipoprotein (HDL) and protects against atherosclerosis. Each gene has been studied alone in transgenic mice but not in combination as the entire cluster. To determine which phenotype is produced by the expression of the entire gene cluster, transgenic mice were generated with a 33-kb human DNA fragment. The results showed that the transgene contained the necessary elements to direct hepatic and intestinal expression of the 3 genes. In the pooled data, plasma concentrations were 257+/-9, 7.1+/-0.5, and 1.0+/-0.2 mg/dL for human apoA-I, apoC-III, and apoA-IV, respectively (mean+/-SEM). Concentrations of these apolipoproteins were higher in males than in females. Human apoA-I and apoC-III concentrations were positively correlated, suggesting that they are coregulated. Transgenic mice exhibited gross hypertriglyceridemia and accumulation of apoB(48)-containing triglyceride-rich lipoproteins. Plasma triglyceride and cholesterol concentrations were correlated positively with human apoC-III concentration, and HDL cholesterol was correlated with apoA-I concentration. In an apoE-deficient background, despite being markedly hypertriglyceridemic, cluster transgenic animals compared with nontransgenic animals showed a 61% reduction in atherosclerosis. This suggests that apoA-I and/or apoA-IV can protect against atherosclerosis even in the presence of severe hyperlipidemia. These mice provide a new model for studies of the regulation of the 3 human genes in combination.

Huntington disease in children: genotype-phenotype correlation

Huntington disease is a neurodegenerative disorder of adulthood; however, a subset of early-onset patients exists, representing 1% of all HD patients. We reviewed a population of 155 HD-families to determine the frequency, molecular and clinical characteristics of children with an onset before the age of 10 years. In each case, a neurological evaluation was performed as well as molecular detection of the expanded CAG triplet in the affected child and both parents. The family history was also reviewed and updated. Seven children (1.92%) had onset of symptoms before the age of 10, two of them were dead by the time of the study. Large CAG expansions with intergenerational instability were identified, and in one case the child's allele was almost three times larger than the allele of the asymptomatic transmitting father, a situation reported only once before. Clinically, they showed preponderance of rigidity, seizures, learning disabilities and a rapid course of the disease. We attempted to use UHDRS. However, consistent results could not be obtained, suggesting that the scale should be revised for use in juvenile cases. HD should be considered in the differential diagnosis of neurodegenerative diseases in children, even in the absence of a positive family history.

Transcriptional regulation of 5-aminolevulinate synthase by phenobarbital and cAMP-dependent protein kinase

5-Aminolevulinate synthase (ALA-S) is a mitochondrial matrix enzyme that catalyzes the first and rate-limiting step of the heme biosynthesis. There are two ALA-S isozymes encoded by distinct genes. One gene encodes an isozyme that is expressed exclusively in erythroid cells, and the other gene encodes a housekeeping isozyme that is apparently expressed in all tissues. In this report we examine the mechanisms by which phenobarbital and cAMP regulate housekeeping ALA-S expression. We have determined that cAMP and phenobarbital effects are additive and the combined action is necessary to observe the cAMP effect on ALA-S mRNA in rat hepatocytes. The role of the cAMP-dependent protein kinase (PKA) has been examined. A synergism effect on ALA-S mRNA induction is observed in rat hepatocytes treated with pairs of selective analogs by each PKA cAMP binding sites. A 870-bp fragment of ALA-S 5'-flanking region is able to provide cAMP and phenobarbital stimulation to chloramphenicol O-acetyltranferase fusion vectors in transiently transfected HepG2 cells. ALA-S promoter activity is induced by cotransfection with an expression vector containing the catalytic subunit of PKA. Furthermore, cotransfection with a dominant negative mutant of the PKA regulatory subunit impairs the cAMP analog-mediated increase, but the phenobarbital-mediated induction is not modified. Our data suggest that the transcription factor cAMP-response element binding protein (CREB) is probably involved in PKA induction of ALA-S gene expression. Finally, heme addition greatly decreases the basal and phenobarbital or cAMP analog-mediated induction of ALA-S promoter activity. The present work provides evidence that cAMP, through PKA-mediated CREB phosphorylation, and phenobarbital induce ALA-S expression at the transcriptional level, while heme represses it.

Human apolipoprotein A-IV reduces gastric acid secretion and diminishes ulcer formation in transgenic mice

We have investigated the involvement of human apolipoprotein A-IV (apoA-IV) in gastric acid secretion and ulcer formation in recently generated apoA-IV transgenic mice. Compared to control littermates, transgenic animals showed a gastric acid secretion decreased by 43-77% whereas only slight variations were observed in the different cell population densities within the gastric mucosa. In addition, no variation in gastrin levels was observed. Transgenics were protected against indomethacin-induced ulcer formation, with lesions diminishing by 45 to 64% compared to controls. These results indicate that endogenous apoA-IV expression can regulate gastric acid secretion and ulcer development.

Inhibition of rat corneal angiogenesis by 16-kDa prolactin and by endogenous prolactin-like molecules

PURPOSE

The cornea is an avascular organ, where induction of new blood vessels involves the turn-on of proangiogenic factors and/or the turn-off of antiangiogenic regulators. Prolactin (PRL) fragments of 14 kDa and 16 kDa bind to endothelial cell receptors and inhibit angiogenesis. This study was designed to determine whether antiangiogenic PRL-like molecules are involved in cornea avascularity.

METHODS

Sixteen-kDa PRL and basic fibroblast growth factor (bFGF) or anti-PRL antibodies were placed into rat cornea micropockets and neovascularization evaluated by the optical density associated with capillaries stained by the peroxidase reaction and by the number of vessels growing into the implants. Prolactin receptors in corneal epithelium were investigated by immunocytochemistry.

RESULTS

bFGF induced a dose-dependent stimulation of corneal neovascularization. This effect was inhibited by coadministration of 16-kDa PRL, as indicated by a 65% reduction in vessel density and a 50% decrement in the incidence of angiogenic responses. Corneal angiogenic reactions of different intensities were induced by implantation of polyclonal and monoclonal anti-PRL antibodies. Corneal epithelial cells were labeled by several anti-PRL receptor monoclonal antibodies.

CONCLUSIONS

These findings show that exogenous 16-kDa PRL inhibits bFGF-induced corneal neovascularization and suggest that PRL-like molecules with antiangiogenic actions function in the cornea. PRL receptors in the corneal epithelium may imply that PRL in the cornea derives from lacrimal PRL internalized through an intracellular pathway. These observations are consistent with the notion that members of the PRL family are potential regulators of corneal angiogenesis.

Regulation of the human apolipoprotein AIV gene expression in transgenic mice

The apolipoprotein (Apo) AI-CIII-AIV gene cluster has a complex pattern of gene expression that is modulated by both gene- and cluster-specific cis-acting elements. In particular the regulation of Apo AIV expression has been previously studied in vivo and in vitro including several transgenic mouse lines but a complete, consistent picture of the tissue-specific controls is still missing. We have analysed the role of the Apo AIV 3' flanking sequences in the regulation of gene expression using both in vitro and in vivo systems including three lines of transgenic mice. The transgene consisted of a human fragment containing 7 kb of the 5' flanking region, the Apo AIV gene itself and 6 kb of the 3' flanking region (-7+6 Apo AIV). Accurate analysis of the Apo AIV mRNA levels using quantitative PCR and Northern blots showed that the 7+6 kb Apo AIV fragment confers liver-specific regulation in that the human Apo AIV transgene is expressed at approximately the same level as the endogenous mouse Apo AIV gene. In contrast, the intestinal regulation of the transgene did not follow, the pattern observed with the endogenous gene although it produced a much higher intestinal expression following the accepted human pattern. Therefore, this animal model provides an excellent substrate to design therapeutic protocols for those metabolic derangements that may benefit from variations in Apo AIV levels and its anti-atherogenic effect.

Lipidic matrix of albendazole sulphoxide: is it an alternative for systemic infections?

As albendazole sulphoxide (ABZS) shows better dissolution properties than albendazole (ABZ), a lipidic matrix with this drug was formulated in order to evaluate if its absorption and so systemic infection chemotherapy could be improved. A cross-over, randomised study in 8 healthy volunteers was carried out, after single administration of 1 g of albendazole or albendazole sulphoxide in lipidic matrix of Gelucire 44/14 (ABZLM and ABZSLM). Absorption was followed performing albendazole sulphoxide dosage in urine samples by high pressure liquid chromatography analysis, during 48 hours. Significant differences were found (p = 0.02) between the urinary recoveries (% E48), being 1.74% and 0.19% the percentage of dose recovered when ABZSLM or of ABZLM were respectively administered. In a previous study of our group similar values were obtained of urinary recovery percentages after albendazole sulphoxide powder administered to another group of healthy volunteers. Lipidic matrix does not improve the physicochemical properties of albendazole sulphoxide powder.

Lipidic matrix of albendazole: an alternative for systemic infections

Albendazole is a poorly water soluble drug, with low oral bioavailability, used in pharmacological treatment of a systemic disease as hydatid parasitosis. Lipidic matrices of Gelucires (44/14 and 35/02) were developed. After "in vitro" studies, one formulation was chosen for a single dose study in 8 healthy volunteers, with a cross-over and randomised design, taking a commercially available tablet as reference. Drug absorption was followed by albendazole sulphoxide dosage in urine by high pressure liquid chromatography. Neither albendazole nor albendazole sulphoxide were recovered in urine after tablet administration while 0.18% (+/- 0.06) of dose was recovered after lipidic matrix administration in the first 24 hours. Besides ageing control were performed up to 18 months post-elaboration. Lipidic matrix with Gelucire 44/14 was revealed as a promising attempt for oral pharmaceutical form in albendazole systemic treatment.

[Congenital cyst adenomatoid malformation of the lung]

The authors report two cases of Congenital Cyst Adenomatoid Malformation diagnosed by ultrasound in the 24th and 27th weeks of pregnancy. The pregnancies had no other problems until their term and deliveries were normal. Surgical resection of the malformation was made on the 8th day of life in one child and on the 11th day in the other. After 2 years, the first child shows a good evolution in weight and height, without lung pathology. After 2 months, the other child also shows a similar condition.

Expression of prolactin mRNA and of prolactin-like proteins in endothelial cells: evidence for autocrine effects

Formation of new capillary blood vessels, termed angiogenesis, is essential for the growth and development of tissues and underlies a variety of diseases including tumor growth. Members of the prolactin hormonal family bind to endothelial cell receptors and have direct effects on cell proliferation, migration and tube formation. Because many angiogenic and antiangiogenic factors are produced by endothelial cells, we investigated whether endothelial cells expressed the prolactin gene. Here we show that bovine brain capillary endothelial cells (BBCEC) in culture express the full-length prolactin messenger RNA, in addition to a novel prolactin transcript, lacking the third exon of the gene. In addition cultures of BBCEC synthesize and secrete prolactin-like immunoreactive proteins with apparent molecular masses of 23, 21 and 14 kDa. The prolactin-like nature of these proteins in supported by the observation that Nb2-cells, a prolactin-responsive cell line, were stimulated to proliferate when co-cultured with endothelial cells and this stimulation was neutralized with prolactin-directed antibodies. Finally, consistent with a possible autocrine effect of endothelial-derived prolactins, polyclonal and monoclonal prolactin antibodies specifically inhibited basal and basis fibroblast growth-factor-stimulated growth of endothelial cells. Taken together, the present findings support the hypothesis of the prolactin gene being expressed in endothelial cells as proteins that could act in an autocrine fashion to regulate cell proliferation.

Attitudes regarding molecular diagnosis in Mexican families at risk of inheriting Huntington's disease

Fifty-eight, at-risk subjects were studied. 81% of the group wished to know whether they had inherited Huntington's disease, even though only 79% would undergo testing. The subjects reported a favorable attitude toward a probable positive result in 81% of cases. Nevertheless, 52% reported they would become depressed, and a small group referred suicidal ideation as response to a probable positive result. Regarding genetic counseling, 59% reported that an at-risk person should not have children, although this increased to 82% if the person knew with certainty that they would develop the disease. Prenatal testing was favored in 74%, and less than half would be willing to have an abortion. Genetic counseling must be insisted upon, the selection of at-risk subjects must be carefully made, and the characteristics of the Mexican population must be taken into account.

The apolipoprotein A-I/C-III/A-IV gene cluster: ApoC-III and ApoA-IV expression is regulated by two common enhancers

Genetic, epidemiological and clinical evidence have clearly demonstrated the importance of the human apolipoprotein (apo) A-I/C-III/A-IV gene cluster in lipid metabolism and heart attack. The transcriptional regulation of these genes determines the level of the encoded proteins and therefore influences the concentration of triglycerides and cholesterol. Here, we analyze the existence of transcription control elements in the 6.6 kb apoC-III/A-IV intergenic region and their influence on the expression of both genes. Two main positive common control elements were found to modulate apoC-III and apoA-IV expression in HepG2 and in Caco-2 cells: the previously described apoC-III enhancer, located 0.8 kb upstream from the cap site of the gene, and a newly detected activating region located in the center of the intergenic sequence. The activity of both elements is highly increased by the hepatic and intestinal transcription factor HNF-4. Analysis of a 641 bp fragment containing the central element showed that it has the properties of a tissue-specific enhancer. Liver nuclear proteins interact with seven DNA binding sites present in this enhancer and HNF-4 specifically interacts with one of these sites. A third positive element, situated immediately upstream from the apoA-IV minimal promoter, is also activated by HNF-4; however, this element is not involved in apoC-III expression. In addition, two negative regions were identified, one located near the apoA-IV gene and the other one between the apoC-III enhancer and the newly identified central enhancer. In conclusion, negative and positive control elements are located in the apoC-III/A-IV intergenic region, including two enhancers important for the expression of the two genes. These results add new evidence that common regulatory elements for the expression of the apoA-I, apoC-III and apoA-IV genes are interspersed throughout the cluster.