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PubMed1990

Incidence and risk factors of HIV infection: a prospective study of seronegative drug users from Milan and northern Italy, 1987-1989.

To assess the incidence of and risk factors for human immunodeficiency virus (HIV) infection among HIV-negative intravenous drug abusers, we studied a cohort of intravenous drug abusers recruited from drug treatment centers in Milan and northern Italy. We enrolled 933 subjects between January 1, 1987 and April 15, 1989 and we followed 460 subjects with one or more visits for a mean follow-up duration of 10.4 months. The incidence rate of HIV infection was 7.4 per 100 person-years, equivalent to a one-year risk of 7.3%. Relative risk was higher in subjects who had been using intravenous drugs for less than 2 years (RR = 2.3). In a case-control analysis, recent frequent syringe sharing was the behavioral variable most strongly associated with HIV infection, with the highest risk in subjects sharing often (OR = 6.1, 90% CI = 2.6-14.7). We found no association with the use of cocaine in addition to heroin nor with sexual habits. Among biologic variables, relative risks were increased in individuals whose T4-lymphocyte count was lower than 1,000 at first visit (RR = 8.5, 90% CI = 2.9-24.3) or who were carrying HBsAg (RR = 1.9, 90% CI = 0.8-4.2).

Acquired Immunodeficiency Syndrome↗

PubMed2026

Clinical and Functional Characterization of Gain-of-Function ABL1 Variants Expands the Phenotypic Spectrum of CHDSKM.

Germline gain-of-function (GOF) variants in ABL1 cause congenital heart defects and skeletal malformations syndrome (CHDSKM), a multisystem developmental disorder characterized by congenital heart disease, skeletal abnormalities, dysmorphic features, and variable developmental delay. More recently, biallelic loss-of-function variants and ABL haploinsufficiency have been associated with distinct phenotypes, expanding the allelic spectrum of ABL1-related disorders. We report three individuals with ABL1 variants. A female infant with tetralogy of Fallot, critical pulmonary stenosis, covered omphalocele, and a lethal outcome was found by rapid trio genome sequencing to harbor a de novo likely pathogenic ABL1 variant, NM_007313.2:c.354G>T p.(Trp118Cys). We also provide updated clinical follow-up of a previously reported individual and describe a third individual, both carrying the recurrent p.(Tyr245Cys) variant. Functional studies were performed and support a GOF mechanism. Similar activation was observed for Tyr245Cys despite the differences in clinical severity. Our findings expand the phenotypic spectrum of ABL1-related CHDSKM to include severe conotruncal heart disease and covered omphalocele. The comparison of two biochemically activating ABL1 variants demonstrates substantial clinical variability despite a shared molecular mechanism. Furthermore, the overlap between ventral body wall abnormalities in GOF disease and omphalocele associated with ABL1 haploinsufficiency suggests that precise regulation of ABL1 signaling is critical for normal ventral body wall formation.

ABL1↗

PubMed2006

Frequency and phenotypes of LRRK2 G2019S mutation in Italian patients with Parkinson's disease.

To evaluate the frequency of the LRRK2 G2019S mutation in Italy, we tested 1,072 probands with Parkinson's disease (PD; 822 sporadic and 250 familial): 20 patients (1.9%) carried the G2019S mutation, 11 patients (1.3%) were sporadic, and 9 (4.3%) had a positive family history. Considering only probands with autosomal dominant inheritance, the G2019S frequency raises to 5.2%. All presented a typical phenotype with variable onset and shared the common ancestral haplotype. Mutation frequency raised from 1.2% in early onset PD to 4.0% in late onset PD.

Amino Acid Substitution↗

PubMedDate not supplied

Pathogenesis of hyperferritinemia cataract syndrome.

Hereditary hyperferritinemia-cataract syndrome (HHCS) is an autosomal dominant disorder characterized by bilateral cataracts and increased serum L-ferritin, in the absence of iron overload. Under physiological conditions, ferritin synthesis is finely regulated at the translational level by iron availability. This regulation is achieved by the high-affinity interaction between cytoplasmic mRNA-binding proteins (iron regulatory proteins, IRPs), and mRNA stem-loop structures, known as iron responsive elements (IREs), located in the untranslated regions (UTRs) of the mRNAs. A single IRE is located on the 5' UTR of a series of genes involved in iron metabolism, like L-ferritin, and the binding IRE-IRPs represses these genes translation. The deregulation of ferritin production responsible of HHCS is caused by heterogeneous mutations in the iron regulatory element (IRE) of L-ferritin that interfere with the binding of iron regulatory proteins, disrupting the negative control of L-ferritin synthesis and causing the constitutive up-regulation of ferritin L-chains. The HHCS families originate from different countries of Europe and North America, suggesting that HHCS may be distributed widely throughout the world and not sporadic, whereas its prevalence remains to be established. The lens seems to be particularly sensitive to the increased amount of L-ferritin and the alteration of the proteic equilibrium in this tissue can be responsible of the cataract. In spite of the elucidation of the genetic basis, the genotype phenotype correlation is not clear. Recently, a study based on the thermo-denaturation profile and dissociation constant of the IRE-IRP complex performed for several mutated IREs has provided evidence for a possible correlation between heterogeneous IRE mutations and serum ferritin levels. On the other hand, the in vivo relevance of these conclusions has not been determined completely. A clinical variability among subjects sharing the same mutation, whether they belonged to the same family or not, has also been demonstrated. These findings suggest that, besides the L-ferritin IRE genotype, additional factors are likely to modulate the lens involvement and the rate of progression to severe cataract in HHCS patients.

Cataract↗

PubMed1998

The structural gene module in Streptococcus thermophilus bacteriophage phi Sfi11 shows a hierarchy of relatedness to Siphoviridae from a wide range of bacterial hosts.

The structural gene cluster and the lysis module from lytic group II Streptococcus thermophilus bacteriophage phi Sfi11 was compared to the corresponding region from other Siphoviridae. The analysis revealed a hierarchy of relatedness. phi Sfi11 differed from the temperate S. thermophilus bacteriophage phi O1205 by about 10% at the nucleotide level. The majority of the changes were point mutations, mainly at the third base position. Only a single gene (orf 695) differed substantially between the two phages. Over the putative minor tail and lysis genes, phi Sfi11 and the lytic group 1 S. thermophilus phi Sfi19 shared regions with variable degrees of similarity. Orf 1291 from phi Sfi19 was replaced by four genes in phi Sfi11, two of which (orf 1000 and orf 695) showed a complicated pattern of similarity and nonsimilarity compared with phi Sfi19. The predicted orf 695 gp resembles the receptor-recognizing protein of T-even coliphages in its organization, but not its sequence. No sequence similarity was detected between phi Sfi11 and phi Sfi19 in the region covering the major head and tail genes. Comparison of the structural gene map of phi Sfi11 with that of Siphoviridae from gram-positive and -negative bacterial hosts revealed a common genomic organization. Sequence similarity was only found between phi Sfi11 and Siphoviridae from gram-positive hosts and correlated with the evolutionary distance between the bacterial hosts. Our data are compatible with the hypothesis that the structural gene operon from Siphoviridae of the low G + C group of gram-positive bacteria is derived from a common ancestor.

Biological Evolution↗

PubMed1993

Optokinetic-vestibular interaction in patients with increased gain of the vestibulo-ocular reflex.

We studied optokinetic nystagmus (OKN), optokinetic afternystagmus (OKAN) and visual-vestibular interaction in five patients with markedly elevated vestibulo-ocular reflex (VOR) gain due to cerebellar atrophy. All had impaired smooth pursuit, decreased initial slow phase velocity of OKN, and impaired ability to suppress the VOR with real or imagined targets. OKN slow phase velocity gradually built up over 25-45 s, reaching normal values for low stimulus velocities (< or = 30 deg/s). Initial velocity of OKAN was increased, but the rate of decay of OKAN was normal. These findings can be explained by models that include separate velocity storage and variable gain elements shared by the vestibular and optokinetic systems.

Adult↗

PubMed1994

Senescence-specific mitochondrial DNA molecules in P. anserina: evidence for transcription and normal processing of the RNA.

In Podospora anserina the phenomenon of senescence was previously shown to be correlated with the presence of senescence-specific circular DNAs (senDNAs), resulting from the amplification of distinct regions (alpha, beta, gamma and epsilon) of the mitochondrial chromosome. The beta region gives rise to senDNAs with variable sizes, but sharing a 1-kb common sequence. Here, we present a molecular analysis of five beta senDNAs. We have determined the nucleotide sequence around the circularization site of each senDNA monomer. In two cases, the presence of a tRNA gene, very close to the 3' end of the monomer, has been observed. This suggests that some beta senDNAs could be generated via a reverse transcription step. We have furthermore shown that the beta senDNAs produce specific transcripts which undergo normal processing of their introns. We propose that a transcription start site, located in the beta common region, is involved in mitochondrial replication allowing the amplification of the beta senDNAs.

Base Sequence↗

PubMed2004

Analysis of the human homologue of the canine copper toxicosis gene MURR1 in Wilson disease patients.

Wilson disease is a human disorder of copper metabolism resulting in toxic copper accumulation. Patients present with a high clinical variability, even when sharing identical mutations. MURR1, the gene causing canine copper toxicosis in Bedlington terriers, maps to chromosome 2 in humans, a region different to the Wilson gene locus. MURR1 might influence human copper metabolism and the clinical presentation of Wilson disease patients. This study analyzed MURR1 gene sequence in Wilson disease patients and MURR1 gene transcription in selected patients. Mutation analysis of three exons of the MURR1 gene including the intron-exon boundaries was performed in 63 Wilson disease patients by direct sequencing. Of the 63 Wilson patients 19 (30%) had basepair changes in the MURR1 gene. Three intronic base pair changes, one new sequence variation and two known polymorphisms were detected, including the GAT/GAC heterozygous state at codon Asn 164 in 15 (24%) of the analyzed patients. This suggests that GAT/GAC heterozygous state at codon Asn 164 is associated with an earlier onset of disease.

Adaptor Proteins, Signal Transducing↗

PubMed1999

Bacterioplankton Community Diversity in a Series of Thermally Stratified Lakes.

> Abstract The dominant members of the bacterioplankton community in a set of 10 small, thermally stratified lakes in northeastern Indiana were determined by denaturing gradient gel electrophoresis (DGGE) of a polymerase chain reaction amplified fragment of 16S rDNA. The variability in community composition was analyzed as function of vertical stratification (epilimnion vs metalimnion), time (July vs August samples), and geographical location. In 58 discrete samples, a range of 8-23 bands were detected (mean = 14, s.d. = 4). For all variables, sample pairs shared about 40-70% of bands. In comparisons between depth strata, pairs of oxic samples shared more bands than an oxic-anoxic pair. There was no obvious relationship between the geographical location of lakes (or their physical connection) and band sharing.http://link.springer-ny.com/link/service/journals/00248/bibs/38n2p126.html

Journal Article↗

PubMed1985

Pharmacology of calcium antagonists.

Although the calcium antagonists verapamil, nifedipine, diltiazem and bepridil are structurally diverse, they share, to a variable extent, several pharmacologic properties. These effects are presumably the result of dose-related inhibition of transmembrane calcium ion flux through the slow channel. In diseased tissue, other routes of calcium entry may also be inhibited, and intracellular sites of action also are now strongly suspected. The calcium antagonists tend to relax vascular smooth muscle in a dose-dependent and site-specific manner. Effective coronary vasodilation is found with each agent; peripheral vasodilation is most pronounced with nifedipine, followed, in descending order of potency, by verapamil, diltiazem and bepridil. Atrioventricular conduction is also inhibited by diltiazem, bepridil and verapamil, whereas nifedipine paradoxically has no effect at therapeutic doses. The calcium antagonists also reduce muscle contractile force, but again in variable degrees. Negative inotropy is significant with verapamil and minimal with diltiazem and bepridil. Nifedipine often causes a reflex increase in contractility and heart rate. At therapeutic doses, bepridil has additional properties: it appears to affect sodium and perhaps potassium channels, producing a quinidine-like effect, and it prolongs the refractory period. Experimentally, bepridil has also been found to extend the duration of the action potential, raise the ventricular fibrillation threshold and possess both class I and class IV antiarrhythmic activity at relatively small doses. If documented clinically, bepridil may prove to be an effective antiarrhythmic as well as antianginal agent.

Action Potentials↗

PubMed1993

Reconstitution of protein kinase C alpha function by the protein kinase C beta-I carboxy terminus.

The Ca(2+)- and phospholipid-dependent Ser/Thr kinase protein kinase C (PKC) plays important roles in the transduction of cellular signals. Various PKC isoforms exist in mammalian cells which share conserved and variable regions as defined by cDNA sequence comparisons. To test whether carboxyl (C) terminal sequences of distinct isoforms can complement each other to yield functional chimeric molecules, we have constructed a PKC chimera in which amino acids 595-672 at the C-terminus of bovine PKC alpha (a) were replaced with the corresponding C-terminal amino acids (598-671) of rat PKC beta-I (b) to yield the chimera alpha/beta-I (ab). The chimera was then characterized biochemically and functionally, and compared with the parental isoforms. Since structure/function analysis of PKC in mammalian experimental systems is complicated by multiple PKC isoforms and by cellular complexity, we stably introduced the PKC constructs into the yeast Saccharomyces cerevisiae, a simple, lower eukaryote with a short doubling time and well established molecular genetics. In yeast, the faithfully expressed PKCab chimera and normal PKC isoforms bound radiolabelled phorbol ester and were recognized on immunoblots by PKC-specific antibodies. The chimera phosphorylated substrate peptides in a PMA- and Ca(2+)-dependent manner, and, upon activation, increased the cell doubling time and the rate of Ca2+ uptake into cells. In addition, PKCab displayed characteristics distinct from normal PKCb, but virtually indistinguishable from normal PKCa. Our findings indicate the reconstitution of PKCa function by the PKCb carboxyl terminus.

Animals↗

PubMed2007

Lethal fetal and early neonatal presentation of adenylosuccinate lyase deficiency: observation of 6 patients in 4 families.

OBJECTIVE: To characterize a new lethal fetal and early postnatal variant of adenylosuccinate lyase (ADSL) deficiency. STUDY DESIGN: This was a retrospective analysis of 6 patients with very early presentation of ADSL deficiency. RESULTS: Most of the 6 patients had impaired intrauterine growth, microcephaly, fetal hypokinesia, and a lack of fetal heart rate variability. Postnatally, they shared severe muscular hypotonia necessitating mechanical ventilation, intractable seizures, and early death. All 6 patients had biochemical evidence of severe (type 1) disease and low residual ADSL activities. All were compound heterozygous for mutations that, based on expression studies, have a pronounced effect on ADSL activity and/or stability. CONCLUSIONS: ADSL deficiency may present with prenatal growth restriction, fetal and neonatal hypokinesia, and rapidly fatal neonatal encephalopathy. This clinical presentation is associated with genotypes resulting in very low residual enzyme activity.

Adenylosuccinate Lyase↗

PubMed1999

Cross-cultural aspects of fears in African children and adolescents.

The purpose of this study was to compare level and type of fears in Nigerian and Kenyan children using the Fear Survey Schedule for Children, Revised (FSSC-R; [Ollendick, T.H. (1983). Reliability and validity of the Revised Fear Survey Schedule for Children (FSSC-R). Behaviour Research and Therapy, 21, 685-692]). A total of 852 males and females between the ages of 8 and 17 were surveyed. Results indicated that Nigerian children reported significantly higher total fear than Kenyan children and that scores from both countries were higher than those found in the United States, Australia and China. This suggests that the cultures of Kenya and Nigeria may share a common variable that makes reporting of fears greater than that reported by children of other world cultures. In addition, Christian children in both countries reported higher levels of fear on several factors than Muslim children, indicating that Islamic beliefs may encourage children to report less fear or to deal with their fears better than Christian beliefs. Finally, children between the ages of 8 and 12 reported greater fear of the unknown than children between 13 and 17 years of age. Overall, these findings suggest that important cultural, religious and age differences exist for levels of childhood fears reported in Nigeria and Kenya.

Adolescent↗

PubMed1996

A model for calculating the hospital costs for pediatric endoscopy.

BACKGROUND: Hospitals increasingly need, besides effectiveness data, accurate and reliable cost data to allocate their resources as efficiently as possible. In this article, a framework to calculate the hospital costs of setting up a new activity is presented and applied to pediatric endoscopy. METHODS: The cost calculations were based on a detailed registration of labor time, materials, space, and equipment needed to perform endoscopy in pediatric patients in a tertiary care hospital, the University Hospital in Leuven, Belgium. RESULTS: The initial investment expenses amount to 70,000 ECU ($91,000 in U.S. money), assuming that the facilities of the adult endoscopy unit can be shared. The additional variable cost for each procedure, including labor time and materials, varies between 100 and about 170 ECU ($130 and $221 U.S.), depending on the type of endoscopy (upper or lower, diagnostic or therapeutic). These basic data can be used to calculate the total costs for pediatric endoscopy under alternative scenarios (e.g., varying total number of procedures). CONCLUSIONS: The costing exercise has given the hospital better insights into the working procedures (and hence costs) of pediatric endoscopy. Other organizations will be able to apply this framework in their setting, since all included cost components, as well as volumes and unit prices, are reported separately.

Anesthesia Department, Hospital↗

PubMed1999

Mapping the specificity of an anti-feline immunodeficiency virus monoclonal antibody using a filamentous phage displayed peptide library.

Recent developments in peptide technology enable the use of random peptide libraries for identifying linear amino acid sequences (mimotopes) which can mimic conformational epitopes without necessarily exhibiting amino acid sequence homology with the native linear sequence. In this study a 15-mer random peptide library displayed on the surface of a filamentous phage has been used to characterise the conformational epitopes recognised by a monoclonal antibody raised against the envelope protein gp120 of feline immunodeficiency virus (FIV). Three mimotopes were identified that reacted with the selecting antibody in an immunoblot assay. Sequence analysis revealed that, whereas the three mimotopes had several amino acids in common, there was no significant homology with the primary amino acid sequence of gp120 although some amino acids were shared between the variable region (V3) and the three mimotopes. Petide mimtopes of complex retroviral glycoproteins may have potential uses as novel vaccines and for the serological diagnosis of FIV.

Amino Acid Sequence↗

PubMed2006

Higher-order factors of the Big Five in a multi-informant sample.

In a large community sample (N=490), the Big Five were not orthogonal when modeled as latent variables representing the shared variance of reports from 4 different informants. Additionally, the standard higher-order factor structure was present in latent space: Neuroticism (reversed), Agreeableness, and Conscientiousness formed one factor, labeled Stability, and Extraversion and Openness/Intellect formed a second factor, labeled Plasticity. Comparison of two instruments, the Big Five Inventory and the Mini-Markers, supported the hypotheses that single-adjective rating instruments are likely to yield lower interrater agreement than phrase rating instruments and that lower interrater agreement is associated with weaker correlations among the Big Five and a less coherent higher-order factor structure. In conclusion, an interpretation of the higher-order factors is discussed, including possible neurobiological substrates.

Adolescent↗

PubMed1998

Relation of task switching to speed, age, and fluid intelligence.

Two studies were conducted to investigate whether a meaningful task-switching construct could be identified and, if so, to determine how it was related to measures of higher order cognition and to adult age. Both studies revealed that measures of task switching were moderately correlated across different combinations of tasks and that a switching construct could be distinguished from a construct reflecting processing speed. The results of the 2nd study revealed that although the task-switching construct was related to age and to measures of episodic memory, inductive reasoning, and spatial visualization, most of the relations between the switching construct and both age and other measures of cognition were shared with other variables.

Adolescent↗

PubMed2000

Verbal fluency in schizophrenia: reduction in semantic store.

OBJECTIVE: This is a study of the word production of patients with schizophrenia using a semantic verbal fluency task to address the unresolved issue of retrieval or storage impairment. METHOD: Twenty-one patients with schizophrenia and 11 matched healthy subjects performed a semantic verbal fluency task on 'food', 'animal' and 'transport' categories in Cantonese for 3 minutes each on five separate trials. RESULTS: Patients generated significantly fewer numbers of words compared with control on each trial. The estimated lexicon size of the patients was significantly smaller than that of the equivalent group. The amount of shared words and variable words generated in all five trials were reduced in the patient group. CONCLUSIONS: Our results suggest that poor verbal fluency in patients with schizophrenia may partly be attributable to reduction in semantic store. The importance of temporal lobe involvement on verbal fluency deficits needs to be emphasised as an integral part of the neurobiological basis of schizophrenia research.

Adult↗