Adenosine deaminase alleles and autistic disorder: case-control and family-based association studies

Adenosine deaminase (ADA) plays a relevant role in purine metabolism, immune responses, and peptidase activity, which may be altered in some autistic patients. Codominant ADA1 and ADA2 alleles code for ADA1 and ADA2 allozymes, the most frequent protein isoforms in the general population. Individuals carrying one copy of the ADA2 allele display 15 to 20% lower catalytic activity compared to ADA1 homozygotes. Recent preliminary data suggest that ADA2 alleles may be more frequent among autistic patients than healthy controls. The present study was undertaken to replicate these findings in a new case-control study, to test for linkage/association using a family-based design, and to characterize ADA2-carrying patients by serotonin blood levels, peptiduria, and head circumference. ADA2 alleles were significantly more frequent in 91 Caucasian autistic patients of Italian descent than in 152 unaffected controls (17.6% vs. 7.9%, P = 0.018), as well as among their fathers. Family-based tests involving these 91 singleton families, as well as 44 additional Caucasian-American trios, did not support significant linkage/association. However, the observed preferential maternal transmission of ADA2 alleles, if replicated, may point toward linkage disequilibrium between the ADA2 polymorphism and an imprinted gene variant located in its vicinity. Racial and ethnic differences in ADA allelic distributions, together with the low frequency of the ADA2 allele, may pose methodological problems to future linkage/association studies. Direct assessments of ADA catalytic activity in autistic individuals and unaffected siblings carrying ADA1/ADA1 vs ADA1/ADA2 genotypes may provide stronger evidence of ADA2 contributions to autistic disorder. Am. J. Med. Genet. (Neuropsychiatr. Genet.) 96:784-790, 2000.

Dramatic brain aminergic deficit in a genetic mouse model of phenylketonuria

Clinical data suggest that brain catecholamines and serotonin are deficient in phenylketonuria (PKU), an inherited metabolic disorder that causes severe mental retardation and neurological disturbances. To test this hypothesis, brain tissue levels of dopamine (DA), norepinephrine (NE), 5-hydroxytryptamine (5-HT) and their metabolites were evaluated in the genetic mouse model of PKU (Pah(enu2)). Results indicated a significant reduction of 5-HT levels and metabolism in prefrontal cortex (pFC), cingulate cortex (Cg), nucleus accumbens (NAc), caudate putamen (CP), hippocampus (HIP) and amygdala (AMY). NE content and metabolism were reduced in pFC, Cg, AMY and HIP. Finally, significantly reduced DA content and metabolism was observed in pFC, NAc, CP and AMY. In pFC, NAc and CP there was also a marked reduction of DA release.

Acamprosate does not antagonise the discriminative stimulus properties of amphetamine and morphine in rats

Acamprosate (calcium acetylhomotaurinate) is a GABA derivative that prevents drinking relapses in a significant number of alcoholics. Since little is known about the interaction of acamprosate with other addictive drugs, we studied the effects of this agent (as sodium salt) in two groups of rats trained to discriminate, respectively, morphine (1.7 mg kg(-1)i.p.) or amphetamine (0.5 mg kg(-1)i.p.) from solvent in a two-lever fixed ratio 30 operant behaviour reinforced by water access. Accordingly to the finding that acamprosate inhibits the action of excitatory aminoacids, its effects were compared with those of dizocilpine (MK-801), an NMDA antagonist. Results show that acamprosate (170 and 320 mg kg(-1)i.p. ) produced a slight, and not significant, shift to the left of generalization curves of both morphine and amphetamine without affecting response rates. In contrast, MK-801 potentiated response rate effects of both morphine and amphetamine without affecting their generalization curves. As far as discriminative stimuli participate in the relapsing process of addiction, our results do not predict a role of acamprosate in the prevention of amphetamine or morphine abuse relapsing.

(-)-Norpseudoephedrine, a metabolite of cathinone with amphetamine-like stimulus properties, enhances the analgesic and rate decreasing effects of morphine, but inhibits its discriminative properties

Like psychomotor stimulants, a weak amphetamine-like agent, such as phenylpropanolamine, enhances the analgesic effects of morphine (MOR). Thus, it is possible that full psychomotor stimulant potency is not required to increase the analgesic action of opiates. The validity of this assumption is here tested by studying the ability of (-)-norpseudoephedrine (NPE), an enantiomer of phenylpropanolamine and a metabolite of cathinone, to influence both the analgesic effects of MOR and its discriminative stimulus properties. In mice NPE (5.6-10.0-17.0 mg/kg i.p.) did not prolong the latency to lick or to remove paws from a plate warmed at 54 degrees C. However, it significantly potentiated the analgesic effect of 3.2 mg/kg of MOR. These results were replicated in rats by use of the formalin test, which measures the numbers of hind paw flinches produced by injecting 50 microl of formalin into the dorsal surface of the paw. The higher dose of NPE (17 mg/kg) increased the effect of sub-analgesic doses of MOR (0.56 and 1.0 mg/kg). In rats trained to discriminate between 0.5 mg/kg of amphetamine and solvent in a two-lever operant behavior reinforced by water access. NPE induced a dose-dependent increment of drug lever responding from 0% at 1.0 mg/kg to 100% at 32.0 mg/kg. In contrast, NPE did not generalize for the MOR cue up to the dose of 56.0 mg/kg, which produced a substantial reduction of the response rate. However, when given in combination, NPE attenuated the discriminative effects of MOR and potentiated its inhibitory action on the response rate. These results exclude a direct action of NPE on the mu opiate system. In conclusion, NPE preserves amphetamine-like properties and these properties are probably responsible for the interaction of the drug with the analgesic and discriminative effects of MOR. Therefore, this study contradicts the assumption that the analgesic effects of MOR can be enhanced by a sympathomimetic drug that lacks significant psychostimulant actions.

Eggshell assembly in Drosophila: processing and localization of vitelline membrane and chorion proteins

The Drosophila eggshell consists of three major proteinaceous layers: the vitelline membrane, the inner chorionic layer, and the outer endochorion. During the latter stages of oogenesis, the proteins that comprise these layers are synthesized and secreted by epithelial follicle cells which surround the maturing oocyte. While there is considerable knowledge of the structural units which comprise the eggshell layers, there is little knowledge of how individual proteins function or interact with one another to form the structure. Immunoelectron microscopy was used to follow the distribution of four different eggshell proteins in the assembling and mature eggshell. sV23 and sV17, follicle cell proteins synthesized during the early stages of eggshell formation (stages 8-10), were distributed within the vitelline membrane layer at all stages. Despite marked temporal differences in their accumulation profiles, s36 and s18, putative chorion proteins, were similarly distributed throughout the floor, pillars, and roof of the endochorion. Although the vitelline membrane appears to be morphologically complete by stage 11, developmental Western blots and immunolocalization data indicate that molecular dynamism persists within the layer throughout the subsequent choriogenic stages. During early chorion formation the vitelline membrane appears to act as a reservoir for chorion proteins since s36 was found predominantly in the vitelline membrane layer of stage 12 egg chambers. During the late choriogenic stages (13-14), both sV17 and sV23 are processed to smaller derivatives. Interactions between the eggshell layers were suggested by ultrastructural analysis of a sV23 protein null mutant which showed that the structural integrity of the outer chorion is dependent upon the presence of a vitelline membrane component.

Geometrical model for the design of gradient-index-rod lens coupling devices

Gaussian beam propagation in a gradient-radial-index medium is presented and discussed. A simple geometrical method for modeling the Gaussian beam inside the gradient-index medium has been developed. The results with this method and those predicted by wave optics have been compared in a number of practical cases. Results show the validity of the ray approach. This is also confirmed by experimental tests on a high-power laser-fiber coupler.

[Neurologic risks caused by perinatal and neonatal problems in a provincial hospital]

The study intends to value results of follow-up of risk neonates hospitalized for the period 1980-88 at Neonatal Intensive Care Unit of Bufalini Hospital Cesena and the course with time of neurologic and neuropsychological alterations, reported to the birth-rate of territory in which operates the Neonatal Intensive Care Unit. The survivor infants attended in follow up have been 419: 63 of neonatal weight less than or equal to 1500 g (group A), 117 of weight 1501-2000 g (group B), 239 of weight greater than 2000 g (group C). The follow-up provided at first 12 months of life a pediatric examination together with motoscopic examination to Milani-Comparetti every two months, at 3 years--4 years and 6 months, 7 years a pediatric examination with evaluation of Intelligence Quotient (N.E.M.I.), at last two months of 1st Primary School evaluation of acquired scholastic learning capacities by reading test of Inizan and calculation test of Meljac. Diagnosis of cerebral palsy (C.P.) has been always placed at first 12 months of life. All the survivors have been executed pediatric checks as foreseen at first 12 months of life. The subjects with CP are 26 (%); of these 13 have an I.Q. less than or equal to 70. The risk to develop CP seems to depend strictly by hypoxic perinatal stress (21/26 infants). The type of CP seems to be conditioned by neonatal weight, in particular as regards spastic paraplegia (10/12 infants of weight less than or equal to 2000 g), but hemiplegia and tetraplegia are with equality distributed (7/14 infants of weight less than or equal to 2000 g).(ABSTRACT TRUNCATED AT 250 WORDS)

[Herpes zoster in a 12-month-old girl subsequent to intrauterine exposure to the varicella-zoster virus]

A few cases have been recorded in which zoster was presumably due to reactivation of V-Z virus acquired during the intrauterine life. In our patient, a 12-month-old infant, the mother had chickenpox during her seventh month of pregnancy.