n-3 fatty acid deficiency decreases phosphatidylserine accumulation selectively in neuronal tissues

We have previously shown that the docosahexaenoate (22:6n-3) status in membrane phospholipids influences the biosynthesis and accumulation of phosphatidylserine (PS) in brain microsomes and C6 glioma cells. In the present study, we investigated whether the observed effect of membrane docosahexaenoic acid status on PS accumulation is universal or occurs specifically in neuronal tissues. We observed that rat brain cortex, brain mitochondria, and olfactory bulb, where 22:6n-3 is highly concentrated, contain significantly higher levels of PS in comparison to liver and adrenal, where 22:6n-3 is a rather minor component. Phospholipid molecular species analysis revealed that in brain cortex, mitochondria, and olfactory bulb 18:0,22:6n-3 was the most abundant species representing 45-65% of total PS. In nonneuronal tissues such as liver and adrenal, 18:0,20:4n-6 was the major PS species. Dietary depletion of n-3 fatty acids during prenatal and postnatal developmental periods decreased the brain 22:6n-3 content by more than 80%, with a concomitant increase in 22:5n-6 in all tissues. Under these conditions, an approximately 30-35% reduction in total PS in rat brain cortex, brain mitochondria, and olfactory bulb was observed, while PS levels in liver and adrenal were unchanged. The observed reduction of PS content in neuronal membranes appears to be due to a dramatic reduction of 18:0,22:6n-3-PS without complete replacement by 18:0,22:5n-6-PS. These results establish that variations in membrane 22:6n-3 fatty acid composition have a profound influence on PS accumulation in neuronal tissues where 22:6n-3 is abundant. These data have implications in neuronal signaling events where PS is believed to play an important role.

[Autosomal dominant Mendelian midline complex. Secundum atrial septal defect associated with cardiac and facial-thoracic defects. A familial case]

The kindred of 38 individuals reported here have various anomalies: 1. facio-thoracic malformations: hypertelorism, nasal deviation, cleft lip and palate, upper-incisors diastema and pectus excavatum; 2. cardiac anomalies: sinus node bradycardia, atrial fibrillation, nodal rhythm, atrial septal defect. Wolff-Parkinson-White syndrome, low insertion of the septal tricuspid valve corresponding to an Ebstein syndrome, pulmonic "en dôme" valve stenosis, aortic valve stenosis, long QT, and intraventricular conduction blocks. Almost all these defects are septal or para-septal. Mitral stenosis is probably rheumatoid. Such median varied pathology has not been yet reported. All the extra-cardiac anomalies are situated along the vertical upper half-body midline. All cardiac anomalies are in the septal or para-septal region. It is an autosomal dominant trait that implies the early embryonic development of the midline of cardiac and extra-cardiac structures.

Effects of gestational alcohol exposure on the fatty acid composition of umbilical cord serum in humans

This study examined the effects of maternal periconceptional alcohol intake on polyunsaturated fatty acid (PUFA) concentrations in human neonates. The area percentage of each fatty acid in cord blood serum from 12 infants born to control women (who consumed <2 mL absolute ethanol/d) was compared with that of 9 infants born to women whose periconceptional alcohol intake averaged > or = 30mL absolute ethanol/d. Periconceptional alcohol use was associated with a 30% increase in the proportion of docosahexaenoic acid (22:6n-3) in cord blood (3.0% of total lipid in control infants compared with 3.9% in alcohol-exposed infants; P < 0.01). The rise in the proportion of 22:6n-3 was responsible for increases in the ratio of n-3 to n-6 fatty acids and the ratio of long-chain n-3 to n-6 fatty acids (P < 0.055). Examination of the lipid-class fatty acid profile indicated that serum lipid alterations were localized to the cholesterol esters; 22:6n-3 in the cholesterol esters of alcohol-exposed infants increased 54% (P < 0.011) and arachidonic acid increased 55% (P < 0. 005). The relative fatty acyl composition of maternal serum showed a significant increase in 18:0 fatty acids in the alcohol-exposed group (25%, P < 0.005) but there were no changes in the other fatty acids. The increase in the proportion of 22:6n-3 was unexpected but is consistent with the hypothesis that this essential lipid may be conserved selectively. These results imply that the lifelong neurobehavioral and sensory dysfunction in fetal alcohol syndrome and other alcohol-related neurodevelopmental disorders may be due in part to PUFA dysregulation.

Plasma total cholesterol concentrations do not predict cerebrospinal fluid neurotransmitter metabolites: implications for the biophysical role of highly unsaturated fatty acids

Low concentrations of a metabolite of serotonin found in cerebrospinal fluid (CSF), 5-hydroxyindolacetic acid (5-HIAA), are strongly associated with suicidal and violent behaviors. Although lowering of plasma total cholesterol has been suggested to increase mortality from suicide and violence by decreasing concentrations of CSF 5-HIAA via changes in membrane biophysical properties, highly unsaturated fatty acids may play a more important role. Violent and nonviolent comparison groups, early- and late-onset alcoholics, and healthy comparison subjects were studied to control for alcohol use and predisposition to violence. Fasting plasma total cholesterol and CSF were assayed under stringently controlled conditions. When all groups were combined (n = 234), plasma cholesterol concentrations had a weak positive correlation with CSF 5-HIAA (r = 0.18, P < 0.01). However, age correlated with both plasma total cholesterol and CSF 5-HIAA concentrations. When age was included in multiple regression models, the correlation between cholesterol and CSF 5-HIAA concentrations was not significant. Cholesterol correlated weakly with CSF 5-HIAA concentrations only in late-onset alcoholics after age was controlled for, but the relation was not significant after correction for multiple testing. CSF homovanillic acid did not correlate with plasma total cholesterol in any group. Plasma total cholesterol had no apparent relation to CSF neurotransmitter metabolites in any group of subjects. Highly unsaturated essential fatty acids, which are also critical determinants of membrane biophysical properties and may be linked to brain serotonin concentrations, should also be considered in studies examining the effect of lowering fat intake on the incidence of suicide and violence.

Long chain polyunsaturated fatty acid formation in neonates: effect of gestational age and intrauterine growth

The present study was designed to evaluate the effect of gestational age and intrauterine growth on the long chain polyunsaturated fatty acid (LCP) synthesis from dietary precursors in neonates as reflected by plasma pools. These have been considered conditionally essential nutrients for normal growth, sensory maturation, and neurodevelopment. In vivo elongation/desaturation of deuterated d5-linoleic acid (d5-LA) to form arachidonic acid (AA), and d5-alpha-linolenic acid (d5-LNA) to form docosahexaenoic acid (DHA), was studied in 19 preterm appropriate-for-gestational-age (AGA) infants, 11 AGA term, and 11 intrauterine growth-retarded (IUGR) infants. They received a dose of 50 mg/kg body weight of d5-LA and d5-LNA enterally during the first days of life; d5-labeled derivatized fatty acids were determined in blood samples obtained at 24, 48, and 96 h after dosing. Lipids were extracted and fatty acids analyzed by gas chromatography and negative ion mass spectrometry. Mean concentrations, microg/mL, and d5/d0 for n-3 and n-6 precursor and products were computed at various times and were also integrated over the complete study period. Significantly higher time-integrated concentration of d5-AA and d5-DHA were observed in preterm infants relative to the other two groups. Time-integrated enrichment of DHA relative to LNA was 100-fold lower in preterms, 410-fold lower in term, and 27-fold lower in IUGR infants. Similar significant declines in product to precursor enrichments were noted for the n-6 series. A significant negative correlation of AA and DHA formation based on time-integrated d5/d0 ratios with gestational age was noted; product/ precursor enrichment versus gas chromatography for the n-6 series had an r of -0.5, p = 0.001, and for the n-3 series had an r of -0.6, p = 0.0001. Birth weight or weight adequacy did not add further strength to the relationship. We conclude that LCP formation from deuterated precursors occurs as early as 26 wk gestation, and in fact is more active at earlier gestational ages; growth retardation appears to slow down or diminish LCP formation. No quantitative estimates of LCP synthesis or nutritional sufficiency can be derived from these data.

In vivo conversion of linoleic acid to arachidonic acid in human adults

Human adults are shown to be capable of conversion of linoleic acid (LA, 18:2 n-6) to arachidonic acid (AA, 20:4 n-6) in vivo. It is confirmed that they can also convert alpha-linolenic acid (LNA, 18:3 n-3) to eicosapentaenoic acid (EPA, 20:5 n-3) and to docosahexaenoic acid (DHA, 22:6 n-3) in vivo. The time course and the maximal response for these processes during the first week after a single dose of the 18-carbon precursor is described. A stable-isotope method in which the protons of the C17 and C18 carbons are substituted with deuterium atoms is used in order to provide for a safe method for the study of human metabolism. High sensitivity and selectivity of detection is assured with negative ion, gas chromatography/mass spectrometry analysis. It is clear that human adults on an ad lib diet carry out EFA metabolism in vivo.

A mutation in OTOF, encoding otoferlin, a FER-1-like protein, causes DFNB9, a nonsyndromic form of deafness

Using a candidate gene approach, we identified a novel human gene, OTOF, underlying an autosomal recessive, nonsyndromic prelingual deafness, DFNB9. The same nonsense mutation was detected in four unrelated affected families of Lebanese origin. OTOF is the second member of a mammalian gene family related to Caenorhabditis elegans fer-1. It encodes a predicted cytosolic protein (of 1,230 aa) with three C2 domains and a single carboxy-terminal transmembrane domain. The sequence homologies and predicted structure of otoferlin, the protein encoded by OTOF, suggest its involvement in vesicle membrane fusion. In the inner ear, the expression of the orthologous mouse gene, mainly in the sensory hair cells, indicates that such a role could apply to synaptic vesicles.

Autosomal dominant secundum atrial septal defect with various cardiac and noncardiac defects: a new midline disorder

We report on a Lebanese family in which 12 persons had an atrial septal defect and various cardiac and noncardiac anomalies. Cardiac anomalies are left axis deviation of QRS, right bundle branch block, atrial fibrillation, Wolff-Parkinson-White syndrome, nodal atrioventricular rhythm, aortic stenosis, pulmonic valve stenosis, mitral stenosis (Lutembacher syndrome), and low implantation of the tricuspid valve (Ebstein disease). Noncardiac abnormalities consisted specially of the presence of hypertelorism, cleft lip, and pectus excavatum. This combination appears to constitute a hitherto undescribed autosomal dominant midline disorder of the heart and upper half of the body with almost full penetrance and variable expressivity. The mutation does not map to any known locus involved in atrial septal defect or conduction block.

Alcohol consumption in rhesus monkeys depletes tissues of polyunsaturated fatty acids and alters essential fatty acid metabolism

Rhesus monkeys that were maintained on an adequate diet but with low levels of essential fatty acids (1.4 en% linoleic, 18:2n-6, and 0.08 en%, linolenic acid, 18:3n-3) became depleted of 20:4n-6, and 22: 6n-3 in their livers, plasma lipoproteins, and erythrocytes during an 18-month period of alcohol exposure (2.6 g kg(-1) day(-1)). Monkeys that consumed alcohol also had higher plasma concentrations of 4-hydroxynonenal compared to controls. The metabolism of 18:2n-6 and 18:3n-3 were evaluated in both groups of animals using deuterium-labeled substrates over a 9-day period. Alcohol consumption did not appear to have an effect on the absorption of either 2H5-18:2n-6 or 2H5-18:3n-3 ethyl esters into the circulation after a single oral dose. However, there was a greater enrichment of deuterium in the biosynthesized fatty acids, 20:4n-6 and 22:6n-3, in the plasma of the monkeys exposed to alcohol compared to controls. These results suggest that chronic alcohol exposure may lead to a stimulation of the rate at which long-chain polyunsaturated fatty acids are biosynthesized to compensate for an increase in lipid peroxidation.

[Complete remission of a mesenteric fibromatosis after taking sulindac]

We report the case of a 22-year-old-man having a familial adenomatous polyposis coli treated by total colectomy with ileo-rectal anastomosis. Two years after the operation, an asymptomatic mesenteric fibromatosis appeared which was nonresectable due to mesenteric vessels infiltration. Nine years later, sulindac therapy was started for residual polyps in the rectal stump. This treatment was taken intermittently, during periods of 1 to 8 months, for 6 years. After 4 years of treatment, the tumor was no longer palpable. Four years after sulindac discontinuation, the patient was operated on for suspicion of intestinal adhesion. The mesenteric fibromatosis had completely disappeared and mesenteric vessels were free. This complete macroscopic regression of a desmoid tumor after sulindac therapy emphasizes again the interest of this treatment for mesenteric fibromatosis.

[Chemotherapy of soft tissue sarcoma in the adult]

The goal of postoperative treatment in adult soft tissue sarcoma is local control, and in high-risk patients prevention of distant failures. Radiation therapy is essential after non-radical surgery. The role of adjuvant chemotherapy on improvement of overall survival remains to be evidenced; however, recent meta-analysis data have confirmed its impact on both local and metastatic evolution of the disease. Because for both radiotherapy and chemotherapy, delay of treatment may be crucial for efficacy following tumor excision, concomitant radiochemotherapy should be considered. Review of the literature as well as personal results showed the feasibility of postoperative radiochemotherapy in adult soft tissue sarcoma, even when the chemotherapeutic associations used included an anthracycline. Prospective study of radiochemotherapy should be performed in order to assess its real impact in terms of efficacy and toxicity.

Identification of a locus on chromosome 7q31, DFNB14, responsible for prelingual sensorineural non-syndromic deafness

In our efforts to identify new loci responsible for non-syndromic autosomal recessive forms of deafness, DFNB loci, we have pursued the analysis of large consanguineous affected families living in geographically isolated areas. Here, we report on the study of a Lebanese family affected with a prelingual profound sensorineural isolated form of deafness. Segregation analysis resulted in a linkage with locus D7S554 to locus D7S2459 on 7q31, with a maximum lod score of 6.3. The causative gene was mapped to a 15 cM interval extending from D7S527 to D7S3074 (on the telomeric side). The distal limit of this interval could be located between D7S496 and D7S3074 which are the closest polymorphic loci flanking the gene underlying Pendred syndrome (PDS) on the centromeric and on the telomeric sides, respectively. To eliminate PDS as a candidate gene, its 21 exons were sequenced. No mutation was detected. This study therefore reports the identification of a novel locus, DFNB14, on chromosome 7q31, in a position proximal to PDS.

A v-SNARE participates in synaptic vesicle formation mediated by the AP3 adaptor complex

Reconstitution of synaptic vesicle formation in vitro has revealed a pathway of synaptic vesicle biogenesis from endosomes that requires the heterotetrameric adaptor complex AP3. Because synaptic vesicles have a distinct protein composition, the AP3 complex should selectively recognize some or all of the synaptic vesicle proteins. Here we show that one element of this recognition process is the v-SNARE, VAMP-2, because tetanus toxin, which cleaves VAMP-2, inhibited the formation of synaptic vesicles and their coating with AP3 in vitro. Mutant tetanus toxin and botulinum toxins, which cleave t-SNAREs, did not inhibit synaptic vesicle production. AP3-containing complexes isolated from coated vesicles could be immunoprecipitated by a VAMP-2 antibody. These data imply that AP3 recognizes a component of the fusion machinery, which may prevent the production of inert synaptic vesicles.

A replication study of violent and nonviolent subjects: cerebrospinal fluid metabolites of serotonin and dopamine are predicted by plasma essential fatty acids

BACKGROUND

Among an independent group of subjects selected for their history of violent, impulsive behaviors and nonviolent control subjects, we attempted to replicate the finding that plasma docosahexaenoic acid concentrations were negatively correlated with cerebrospinal fluid 5-hydroxyindoleacetic acid (CSF 5-HIAA) concentrations.

METHODS

CSF 5-HIAA and homovanillic acid (HVA), fasting total cholesterol, and plasma fatty acid concentrations were examined in violent and nonviolent subjects matched for their severity of alcohol dependence.

RESULTS

Violent subjects had significantly higher lifetime violence and hostility ratings and lower concentrations of CSF 5-HIAA than nonviolent subjects. Plasma docosahexaenoic acid was negatively correlated with CSF 5-HIAA only among violent subjects.

CONCLUSIONS

This observational study suggests that dietary essential fatty acids may change neurotransmitter concentrations. Prospective dietary intervention trials will be required to determine if increasing dietary intake of docosahexaenoic acid will increase or decrease either CSF 5-HIAA concentrations or impulsive and violent behaviors.

Essential fatty acids predict metabolites of serotonin and dopamine in cerebrospinal fluid among healthy control subjects, and early- and late-onset alcoholics

BACKGROUND

Impulsive violence, suicide, and depression are strongly associated with low concentrations of cerebrospinal fluid 5-hydroxyindoleacetic acid (CSF 5-HIAA). Increased suicide and trauma reported in some cholesterol-lowering trials may be related to altered concentrations of polyunsaturated fatty acids rather than cholesterol, a possible surrogate marker.

METHODS

CSF 5-HIAA and homovanillic acid (HVA), total cholesterol, and plasma fatty acid concentrations were examined in 176 subjects, including 49 healthy volunteers, and 88 early- and 39 late-onset alcoholics.

RESULTS

Among each group, polyunsaturated fatty acids predicted both CSF 5-HIAA and CSF HVA concentrations, but total cholesterol was unrelated to either neurotransmitter metabolite. The relationships between plasma 22: 6n3 and CSF 5-HIAA were significantly different when healthy volunteers (r = .35) were compared to early-onset alcoholics (r = -.38) (p < .0002).

CONCLUSIONS

Dietary studies are indicated to determine if essential fatty acid supplementation can influence central nervous system serotonin and dopamine metabolism and modify impulsive behaviors related to these neurotransmitters.

N-3 fatty acid deficiency in the rat pineal gland: effects on phospholipid molecular species composition and endogenous levels of melatonin and lipoxygenase products

N-3 essential fatty acid deficiency affects a number of biological and physiological processes. In this study, we investigated the effect of n-3 essential fatty acid status on two key pineal biochemical functions, melatonin production and lipoxygenation, using pineal glands from rats given an n-3-adequate or n-3-deficient diet. The pineal total lipid profile and phospholipid molecular species distribution altered by n-3 deficiency were evaluated in parallel. In pineal glands from n-3-deficient rats, an 87% reduction of 22:6n-3 (docosahexaenoic acid) was observed, and this decrease was accompanied by increases in 22:4n-6 (docosatetraenoic acid, 3-fold), 22:5n-6 (docosapentaenoic acid, 12-fold), and 20:4n-6 (arachidonic acid, 48%). The significant decrease of 22:6n-3 containing species in phosphatidylcholine (PC), phosphatidylethanolamine (PE), and phosphatidylserine (PS) was also evident. These decreases in 22:6n-3 containing PL species were compensated by substantial accumulations of 22:4n-6 or 22:5n-6 and slight increases in 20:4n-6 containing PL species in PC and PE. In PS, however, the accumulation of n-6 species was not adequate to compensate for the loss of 22:6n-3 species. N-3 deficiency significantly reduced non-esterified 20:4n-6 and 22:6n-3 levels in pineals (25% and 65%, respectively). Concomitantly, the endogenous 12-HETE level decreased by 35% in deficient pineals. In contrast, n-3 deficiency led to a more than 60% increase in the daytime pineal melatonin level. In conclusion, n-3 fatty acid deficiency not only has profound effects on pineal lipid profiles but also on pineal biochemical activities. These results suggest that n-3 fatty acids may play a critical role in regulating pineal function.

[Comparison of the effect of subcutaneous injection of adrenaline and terbutaline in asthma crisis in infants]

BACKGROUND

Edema of the mucous membranes lining the airways is a major factor of airway obstruction in asthma. Stimulation of both alpha and beta-adrenergic receptors is thus logically useful to reduce edema through vasoconstriction and to cause smooth muscle relaxation. The aim of this work was to compare the effects of subcutaneous epinephrine vs terbutaline for treating acute attack of asthma in infants.

PATIENTS AND METHODS

Fifty-four infants aged less than 30 months admitted for acute asthma attacks were included in this study. None had previous cardiovascular or definite pulmonary disease and none had tachycardia above 200/min. The patients were randomly given subcutaneous epinephrine, 10 micrograms/kg (n = 28) or subcutaneous terbutaline at the same dosage (n = 26).

RESULTS

Improvement in accessory muscle use, oxygen saturation, PaO2 and PCO2 was similar in both groups. The respiratory rate was significantly improved after administration of epinephrine (P = 0.05). No adverse effects were seen in either drug.

CONCLUSION

Subcutaneous administration of epinephrine is as effective as terbutaline in treating acute attack of asthma in infants. This drug, easy to use and of low-cost, could be the treatment of choice in developing countries.