Growth patterns and outcomes of growth hormone therapy in patients with acrodysostosis.

INTRODUCTION: Severe short stature is a feature of acrodysostosis, but data on growth are sparse. Treatment with recombinant human growth hormone (rhGH) is used in some centers to increase final height, but no studies have been published so far. Our objective was to conduct a multicenter, retrospective, cohort study to investigate growth in individuals with both types of acrodysostosis, treated with rhGH or not; we used the new nomenclature to describe acrodysostosis, as this disease belongs to the large group of inactivating PTH/PTHrP signaling disorders (iPPSD); acrodysostosis refers to iPPSD4 (acrodysostosis type 1 due to PRKAR1A mutations) and iPPSD5 (acrodysostosis type 2, due to PDE4D mutations). METHODS: We present auxological data from individuals with genetically characterized iPPSD4, and participants with clinical features of iPPSD5. RESULTS: We included 20 and 17 individuals with iPPSD4 and iPPSD5, respectively. The rhGH-treated iPPSD4 patients (n = 9) were smaller at birth than those who did not receive rhGH (median - 2.2 SDS vs. - 1.7 SDS); they showed a trend to catch-up growth during rhGH therapy (median 0.5 SDS in the first year). The rhGH-treated patients (n = 5) reached a better final height compared to those who did not receive rhGH (n = 4) (median - 2.8 SDS vs. - 3.9 SDS), suggesting that rhGH is efficient to increase height in those patients. The difference in target height to final height ranged between 1.6 and 3.0 SDS for iPPSD4 not treated with rhGH (n = 4), 2.1-2.8 SDS for rhGH-treated iPPSD4 (n = 5), 0.6-5.5 SDS for iPPSD5 not treated with rhGH (n = 5) and 2.5-3.1 for rhGH-treated iPPSD5 (n = 2). CONCLUSION: Final height may be positively influenced by rhGH in patients with acrodysostosis/iPPSD. Our rhGH-treated cohort started therapy relatively late, which might explain, at least in part, the limited effect of rhGH on height.

Molecular characterization of infectious bursal disease virus (IBDV) isolated in Argentina indicates a regional lineage.

In Argentina, classical vaccines are used to control infectious bursal disease virus (IBDV); however, outbreaks of IBDV are frequently observed. This could be due to failures in the vaccination programs or to the emergence of new strains, which would be able to break through the protection given by vaccines. Hence, genetic characterization of the viruses responsible for the outbreaks that occurred in recent years is crucial for the evaluation of the control programs and the understanding of the epidemiology and evolution of IBDV. In this study, we characterized 51 field samples collected in Argentina (previously identified as IBDV positive) through the analysis of previously identified apomorphic sequences. Phylogenetic analysis of regVP2 showed that 42 samples formed a unique cluster (Argentinean lineage), seven samples were typical classical strains (one of them was a vaccine strain), and two belonged to the very virulent lineage (vvIBDV). Interestingly, when the analysis was performed on the regVP1 sequences, the field samples segregated similarly to regVP2; thus, we observed no evidence of a reassortment event in the Argentinean samples. Amino acid sequence analysis of regVP2 showed a particular pattern of residues in the Argentinean lineage, particularly the presence of T272, P289 and F296, which had not been reported before as signature sequences for any IBDV phenotype. Notably, the residue S254, characteristic of the antigenic variant, was not present in any of the Argentinean samples.

Phylogenetic analysis of bluetongue virus serotype 4 field isolates from Argentina.

Bluetongue is an insect-transmitted viral disease of ruminant species, which represents a major barrier to the international trade of animals and their products. Bluetongue virus (BTV) has a genome composed of ten linear segments of dsRNA, which code for at least ten different viral proteins. In South America, serological evidence for the presence of BTV has been found in Peru, Argentina, Brazil, Ecuador and Chile. Brazil and Argentina are the only South American countries where BTV has been isolated. In Brazil, only one BTV isolate, serotype 12, has been reported, whereas in Argentina five BTV serotype 4 isolates have been obtained from cattle without clinical signs. Three of these five isolates were isolated during 1999-2001, whereas two of them were obtained as part of the present work. This study describes sequence comparisons and phylogenetic analyses of segment (Seg)-2, Seg-3, Seg-6, Seg-7 and Seg-10 of the first Argentinian field isolates of BTV. The analysis of Seg-2 and Seg-6 resulted in a single cluster of Argentinian sequences into the serotype 4 clade. In addition, the Argentinian sequences grouped within the nucleotype A clade, along with reference strains. The analysis of Seg-3, Seg-7 and Seg-10 showed that the Argentinian isolates grouped into the western topotype, indicating that the circulating virus had an African/European origin. Phylogenetic analysis revealed that the Argentinian sequences present a South American genetic identity, suggesting an independent lineage evolution.

Molecular characterization of chicken infectious anemia virus circulating in Argentina during 2007.

Chicken infectious anemia virus (CAV) is a worldwide-distributed infectious agent that affects commercial poultry. Although this agent was first detected in Argentina in 1994, no further studies on CAV in this country were reported after that. The recent increased occurrence of clinical cases of immunosuppression that could be caused by CAV has prompted this study. Our results confirmed that CAV is still circulating in commercial flocks in Argentina. Phylogenetic analysis focusing on the VP1 nucleotide sequence showed that all Argentinean isolates grouped together in a cluster, sharing a high similarity (> 97%) with genotype B reference strains. However, Argentinean isolates were distantly related to other strains commonly used for vaccination in this country, such as Del-Ros and Cux-1. Sequence analysis of predicted VP1 peptides showed that most of the Argentinean isolates have a glutamine residue at positions 139 and 144, suggesting that these isolates might have a reduced spread in cell culture compared with Cux-1. In addition, a particular amino acid substitution at position 290 is present in all studied Argentinean isolates, as well as in several VP1 sequences from Malaysia, Australia, and Japan isolates. Our results indicate that it is possible to typify CAV strains by comparison of VPI nucleotide sequences alone because the same tree topology was obtained when using the whole genome sequence. The molecular analysis of native strains sheds light into the epidemiology of CAV in Argentinean flocks. In addition, this analysis could be considered in future control strategies focused not only on breeders but on broilers and layer flocks.

Identification of personal factors that determine work outcome for adults with intellectual disability.

BACKGROUND: Access to employment for people with intellectual disability (ID) has become a social priority. The aim of the present study is to try to determine which variables [sociodemographic variables, intelligence quotient (IQ), presence or absence of a psychiatric disorder, functioning, self-determination, and behavioural problems] could most reliably account for access to remunerated employment of people with ID. METHODS: Two groups of people with ID participated in this study: (1) 69 workers in a sheltered-employment programme; and (2) 110 clients of programmes in sheltered workshops. Both programmes were run by the Pardo-Valcarce Foundation in Madrid (Spain). The following variables were assessed for every participant: IQ, functioning, behavioural problems, self-determination and presence of psychiatric symptoms. A binary logistic regression analysis was carried out in order to identify the variables that best explained work outcome (sheltered workshop programme vs. sheltered employment programme). RESULTS: Although IQ showed no significant differences between the two groups of participants, the remaining variables did: behavioural problems, functioning, psychiatric symptoms and self-determination significantly explained work outcome. As for sociodemographic variables, whereas gender did not show any significant relationship with the labour status of the participants, significant differences were found when considering variables such as age and pension benefits. CONCLUSIONS: All the main variables considered, except IQ, turned out to be significant. Our findings should be considered encouraging, as they apparently show that both personal and social efforts can help individuals to overcome their low intellectual functioning in order to achieve access to employment. Such study highlights the importance of a prior psychopathological evaluation and efforts to enhance self-determination in order to improve work inclusion for people with ID.

Experimental reactivation of equine herpesvirus-3 following corticosteroid treatment.

State of latency, well known for several herpesviruses, has been proposed for equine herpesvirus-3 (EHV-3) and supported by epidemiological observations. No detailed assessment about reactivation, patterns of excretion and reexcretion has been formally reported. An experimental reactivation study by corticosteroid treatment in previously naturally infected horses was therefore carried out. Two polo mares with clinical and virologically confirmed history of equine coital exanthema were injected with dexamethasone and prednisolone on 3 successive days. Clinical signs, body temperature and clinical samples for virological and serological studies were obtained daily. Mares did not show any systemic clinical signs or hyperthermia. EHV-3 shedding, seroconversion and the presence of a small lesion were observed in one of the mares under study 2 weeks after corticosteroid treatment. The results demonstrate that this virus exhibits a latency-reactivation behaviour similar to that of other alpha herpesviruses. Reactivation of latency may have an important bearing on the appearance of clinical signs in mares and/or stallions during the breeding season without the actual evidence of transfer from mare to stallion or vice versa.

Nerve injury induces gap junctional coupling among axotomized adult motor neurons.

Neonatal spinal motor neurons are electrically and dye-coupled by gap junctions, but coupling is transient and disappears rapidly after birth. Here we report that adult motor neurons become recoupled by gap junctions after peripheral nerve injury. One and 4-6 weeks after nerve cut, clusters of dye-coupled motor neurons were observed among axotomized, but not control, lumbar spinal motor neurons in adult cats. Electrical coupling was not apparent, probably because of the electrotonic distance between dendrodendritic gap junctions and the somatic recording location. Analyses of gap junction protein expression in cat and rat showed that the repertoire of connexins expressed by normal adult motor neurons, Cx36, Cx37, Cx40, Cx43, and Cx45, was unchanged after axotomy. Our results suggest that the reestablishment of gap junctional coupling among axotomized adult motor neurons may occur by modulation of existing gap junction proteins that are constitutively expressed by motor neurons. After injury, interneuronal gap junctional coupling may mediate signaling that maintains the viability of axotomized motor neurons until synaptic connections are reestablished within their targets.

Connexin35 mediates electrical transmission at mixed synapses on Mauthner cells.

Auditory afferents terminating as "large myelinated club endings" on goldfish Mauthner cells are identifiable "mixed" (electrical and chemical) synaptic terminals that offer the unique opportunity to correlate physiological properties with biochemical composition and specific ultrastructural features of individual synapses. By combining confocal microscopy and freeze-fracture replica immunogold labeling (FRIL), we demonstrate that gap junctions at these synapses contain connexin35 (Cx35). This connexin is the fish ortholog of the neuron-specific human and mouse connexin36 that is reported to be widely distributed in mammalian brain and to be responsible for electrical coupling between many types of neurons. Similarly, connexin35 was found at gap junctions between neurons in other brain regions, suggesting that connexin35-mediated electrical transmission is common in goldfish brain. Conductance of gap junction channels at large myelinated club endings is known to be dynamically modulated by the activity of their colocalized glutamatergic synapses. We show evidence by confocal microscopy for the presence of the NR1 subunit of the NMDA glutamate receptor subtype, proposed to be a key regulatory element, at these large endings. Furthermore, we also show evidence by FRIL double-immunogold labeling that the NR1 subunit of the NMDA glutamate receptor is present at postsynaptic densities closely associated with gap junction plaques containing Cx35 at mixed synapses across the goldfish hindbrain. Given the widespread distribution of electrical synapses and glutamate receptors, our results suggest that the plastic properties observed at these identifiable junctions may apply to other electrical synapses, including those in mammalian brain.

Phylogenetic analysis of classical swine fever virus (CSFV) field isolates from outbreaks in South and Central America.

To date, there is little information concerning the epidemiological situation of classical swine fever (CSF) in the Americas. Besides summarizing the available data, genotyping of isolates from outbreaks in domestic pigs in several countries of South and Central America was performed. For this, a 190 base fragment of the E2 envelope glycoprotein gene was used. European strains and isolates, and historical isolates from the United States (US) were included for comparison. In contrast to the situation in most parts of Europe, where group 2 isolates predominate, it was found that all the isolates from the American continent analyzed belonged to group 1 and were further resolved into three subgroups. The Cuban isolates clustered in subgroup 1.2, whereas the isolates from Honduras and Guatemala clustered in subgroup 1.3. The remaining isolates from Argentina, Brazil, Colombia and Mexico generated four poorly resolved clusters in subgroup 1.1, together with the vaccine strains, with historical European and US isolates, and with a recent Russian isolate. While the vaccine strains and the historical European isolates formed a relatively distinct cluster, one of the US isolates clustered together with the Mexican, and another one with Colombian isolates. Historically, CSF (hog cholera) was observed almost simultaneously in the US and in Europe in the first half of the 19th century, and its origin remains a matter of discussion. Our results showed that the US isolates are closely related to isolates from South America, while appearance of isolates in Cuba on one hand and in Honduras and Guatemala on the other hand, seems to have been due to unrelated events. This allows to speculate that at least in the American continent, CSF virus may have appeared independently in several regions, and spreading may have been a secondary effect.

The Effect of a Combination Saliva Substitute for the Management of Xerostomia and Hyposalivation.

OBJECTIVE: The objective of this study was to evaluate the difference between the combination agent of xylitol, beatine and olive oil in a chewable capsule versus the control agent of a sorbitol tablet in subjects with hyposalivation and xerostomia. MATERIALS AND METHODS: The subjects had xerostomia over 3 months and a measured hyposalivation. The study was 3 weeks in duration, with 2 treatment phases of 1 week and a 7 day wash out period in between. At the end of each treatment phase, subjects returned for a follow up evaluation. At this visit they were given the subjective sensation questionnaire, as well as their unstimulated whole salivary flow and stimulated whole salivary flow were measured. RESULTS: There was a greater increase in the unstimulated and stimulated whole salivary flow rate, although the results were not statistically significant. The subjective evaluation as measured by the questionnaire showed that both agents reduced the mean score as compared to the baseline, although only the findings in the active agent was statistically significant (p = 0.0015). CONCLUSION: The significant conclusions found in this study were that the active agent provided a significant subjective improvement in speech, swallowing, and decreased subjective xerostomia as compared to the control tablet. CLINICAL RELEVANCE: This combination agent has a significant effect on patients with subjective xerostomia but does not have a significant effect on objective hyposalivation.

Heterotypic gap junctions at glutamatergic mixed synapses are abundant in goldfish brain.

Gap junctions provide for direct intercellular electrical and metabolic coupling. The abundance of gap junctions at "large myelinated club ending (LMCE)" synapses on Mauthner cells (M-cells) of the teleost brain provided a convenient model to correlate anatomical and physiological properties of electrical synapses. There, presynaptic action potentials were found to evoke short-latency electrical "pre-potentials" immediately preceding their accompanying glutamate-induced depolarizations, making these the first unambiguously identified "mixed" (i.e., chemical plus electrical) synapses in the vertebrate CNS. We recently showed that gap junctions at these synapses exhibit asymmetric electrical resistance (i.e., electrical rectification), which we correlated with total molecular asymmetry of connexin composition in their apposing gap junction hemiplaques, with connexin35 (Cx35) restricted to axon terminal hemiplaques and connexin34.7 (Cx34.7) restricted to apposing M-cell plasma membranes. We now show that similarly heterotypic neuronal gap junctions are abundant throughout goldfish brain, with labeling exclusively for Cx35 in presynaptic hemiplaques and exclusively for Cx34.7 in postsynaptic hemiplaques. Moreover, the vast majority of these asymmetric gap junctions occur at glutamatergic axon terminals. The widespread distribution of heterotypic gap junctions at glutamatergic mixed synapses throughout goldfish brain and spinal cord implies that pre- vs. postsynaptic asymmetry at electrical synapses evolved early in the chordate lineage. We propose that the advantages of the molecular and functional asymmetry of connexins at electrical synapses that are so prominently expressed in the teleost CNS are unlikely to have been abandoned in higher vertebrates. However, to create asymmetric coupling in mammals, where most gap junctions are composed of connexin36 (Cx36) on both sides, would require some other mechanism, such as differential phosphorylation of connexins on opposite sides of the same gap junction or on asymmetric differences in the complement of their scaffolding and regulatory proteins.

Nucleotide sequence of the ermE distal flank of the erythromycin biosynthesis cluster in Saccharopolyspora erythraea.

A 7023 nucleotide BamHI fragment immediately upstream of the eryK gene of the erythromycin (Er) biosynthesis cluster in Saccharopolyspora erythraea was sequenced. Computer-assisted analysis of this sequence reveals the existence of seven ORFs that display the codon preferences typical of actinomycete genes. Six of these show homology to known genes: an esterase, a transposase, a peptidyl-prolyl cis-trans isomerase, a subtilisin inhibitor-like protein, and two genes involved in bacterial cell wall biosynthesis. All the ORFs are transcribed toward the Er biosynthetic gene cluster (in the same direction as eryK). From the predicted functions of the putative ORF products none of these genes appear to be involved in the biosynthesis of Er. The eryK gene thus most likely defines one end of the Er biosynthetic gene cluster.

Cloning and disruption of a fragment of Streptomyces halstedii DNA involved in the biosynthesis of a spore pigment.

A 5.2-kb BamHI fragment of Streptomyces halstedii was cloned by homology to the actI-carrying fragment which codes for part of the actinorhodin polyketide synthase of Streptomyces coelicolor A3(2). Gene disruption using the integrative plasmid vector, pGM160, and gene replacement experiments using a fragment mutated by introducing a cassette containing the gene encoding thiostrepton resistance, showed that the alteration of this region in the chromosome of S. halstedii caused sporulating colonies to remain white instead of taking on the typical green colour of sporulating wild-type colonies. This suggests that this fragment is involved in the biosynthesis of a spore pigment. In addition, the BamHI fragment complemented the whiE mutation of S. coelicolor C107 which confers to this mutant a white phenotype, indicating that both pigments could have a similar biosynthetic origin.

Hybridization and DNA sequence analyses suggest an early evolutionary divergence of related biosynthetic gene sets encoding polyketide antibiotics and spore pigments in Streptomyces spp.

The whiE gene cluster of Streptomyces coelicolor, which is related to gene sets encoding the biosynthesis of polycyclic aromatic polyketide antibiotics, determines a spore pigment. Southern blotting using probes from three different parts of the whiE cluster revealed related gene sets in about half of a collection of diverse Streptomyces strains. A 5.2-kb segment of one such cluster, sch, previously shown to determine spore pigmentation in Streptomyces halstedii, was sequenced. Seven open reading frames (ORFs), two of them incomplete, were found. Six of the ORFs resemble the known part of the whiE cluster closely. The derived gene products include a ketosynthase (= condensing enzyme) pair, acyl carrier protein and cyclase, as well as two of unidentified function. The seventh ORF diverges from the main cluster and encodes a protein that resembles a dichlorophenol hydroxylase. Comparison with sequences of related gene sets for the biosynthesis of antibiotics suggests that gene clusters destined to specify pigment production diverged from those destined to specify antibiotics early in the evolution of the Streptomyces genus.

Regulation of synaptic strength at mixed synapses: effects of dopamine receptor blockade and protein kinase C activation.

Previous studies of the mixed excitatory synapses between eighth nerve afferents and the lateral dendrite of the goldfish Mauthner (M-) cell have shown that synaptic strength is enhanced for an hour or longer following either repeated brief tetanizations or local extracellular applications of dopamine. Both the initial electrotonic coupling potential, mediated via current flow through gap junctions, and the subsequent chemically mediated excitatory postsynaptic potentials (EPSPs) are potentiated. Different second messenger pathways are implicated in the postsynaptic induction of these potentiations, with a Ca2+ influx presumably triggering the activity dependent long-term potentiations (LTP) and dopamine acting via a cAMP dependent pathway. Experiments performed to determine whether the LTP involves a stimulus-induced release of dopamine or requires a background level of dopamine receptor activation suggest neither is the case, as tetanization in the presence of a D1 receptor antagonist, which blocks the dopamine effects, produced an LTP comparable to that in the absence of the blocker. The effects of Ca2+ are presumably not due to protein kinase C (PKC) activation, since phorbol esters had no effect on the mixed excitatory synaptic responses, although they did enhance the frequency of spontaneously occurring inhibitory PSPs.

Short-range functional interaction between connexin35 and neighboring chemical synapses.

Auditory afferents terminating as mixed, electrical, and chemical, synapses on the goldfish Mauthner cells constitute an ideal experimental model to study the properties of gap junctions in the nervous system as well as to explore possible functional interactions with the other major form of interneuronal communication--chemically mediated synapses. By combining confocal microscopy and freeze-fracture replica immunogold labeling (FRIL), we found that gap junctions at these synapses contain connexin35 (Cx35), the fish ortholog of the neuron-specific human and mouse connexin36 (Cx36). Conductance of gap junction channels at these endings is known to be dynamically modulated by the activity of their co-localized chemically mediated glutamatergic synapses. By using simultaneous pre- and postsynaptic recordings at these single terminals, we demonstrate that such functional interaction takes place in the same ending, within a few micrometers. Accordingly, we also found evidence by confocal and FRIL double-immunogold labeling that the NR1 subunit of the NMDA glutamate receptor, proposed to be a key regulatory element, is present at postsynaptic densities closely associated with gap junction plaques containing Cx35. Given the widespread distribution of Cx35- and Cx36-mediated electrical synapses and glutamatergic synapses, our data suggest that the local functional interactions observed at these identifiable junctions may also apply to other electrical synapses, including those in mammalian brain.

Dynamic analysis of the righting reflex in toads; recovery after hemilabyrinthectomy.

Static and dynamic measurements of the righting reflex were performed in intact toads (Bufo arenarum platensis) and at different stages of recovery from hemilabyrinthectomy. Reflex activity was evaluated by the toad's capacity to maintain a horizontal head position while rolled sideways. Static data were obtained from frontal photographs. In dynamic experiments platform position (stimulus) was measured through a potentiometer, while a linear accelerometer glued to the cranium was used to record head tilts. The dynamic study included a linear systems analysis using sinusoids of 0.5-3 Hz with rolls of up to 30° to each side. Hemilabyrinthectomy produced a head tilt towards the lesioned side, and gain decay and phase lag increase in the dynamic response. All postural defects recovered progressively within 30-60 days as already described in other species. Nevertheless, the tonic head deviation produced by dynamic stimuli of frequencies above 1 Hz did not recover. This remnant defect has not been observed in previous studies in which only static observations were performed. The involvement of a frequency-dependent rectifying mechanism in postural compensation is discussed.

Electrophysiological characteristics of the Mauthner cell of the weakly electric fish Gymnotus carapo.

The Mauthner cell (M-cell) of the 'weakly electric fish' Gymnotus carapo was investigated with electrophysiological techniques. The antidromic action potential, the recurrent inhibitory input and the posterior VIIIth nerve excitatory input in this cell exhibited characteristics similar to those described in the goldfish. In addition, we found an excitatory input evoked by spinal stimulation at intensities subthreshold for M-cell axons.

Medullary control of lumbar motoneurons during carbachol-induced motor inhibition.

The present study examined the effects of stimulation of the medullary nucleus reticularis gigantocellularis (NRGc) on the Ia-monosynaptic reflex and the membrane potential of lumbar motoneurons. Stimulation of the NRGc was carried out in acute decerebrate cats during motor suppression induced by the intrapontine microinjection of carbachol. During carbachol-induced motor suppression, compared with control conditions (prior to the administration of carbachol), NRGc stimulation resulted in a statistically significant reduction in the Ia-monosynaptic reflex. This effect was maximal at an interval of 45 ms following NRGc stimulation. NRGc stimulation also induced, in lumbar motoneurons, a large amplitude (3.17 mV +/- 0.36 [S.E.M.]), long duration (54.73 ms +/- 3.52 [S.E.M.]) inhibitory postsynaptic potential whose peak coincided with the interval of maximum reflex suppression. These results suggest that carbachol activates pontine neurons that excite cells of the medullary NRGc. We believe that these medullary neurons, in addition to those of the nucleus pontis oralis (NPO)7, participate in the modulation of the descending inhibitory pathway that is responsible for the phenomenon of response-reversal and generalized atonia during naturally occurring active (i.e. REM) sleep.

Nitric oxide synthase distribution in the goldfish Mauthner cell.

NADPH-diaphorase histochemical staining was used to assess the distribution of the enzyme nitric oxide synthase (NOS) in the goldfish brain, with the emphasis on the Mauthner (M-) cell, a reticulospinal neuron, and its inputs. Labeling was specific for certain cell types, including the M-cell, which stained heavily. The reaction product in this neuron was uniformly distributed along its axon, soma, and ventral and lateral dendrites. Afferents which synapse with the M-cell were also NADPH-diaphorase positive, including an identified class of inhibitory interneurons and the large myelinated club endings (LMCE) of eighth nerve fibers. The presence of NADPH-diaphorase in a lower level brainstem circuit that undergoes activity-dependent long-term potentiation of both excitatory and inhibitory synapses and is accessible for morpho-functional correlations provides the opportunity to elucidate the mechanism and role of nitric oxide at the single cell level.