Postural control in Down syndrome: the use of somatosensory and visual information to attenuate body sway

The purpose of this study was to examine the effects of visual and somatosensory information on body sway in individuals with Down syndrome (DS). Nine adults with DS (19-29 years old) and nine control subjects (CS) (19-29 years old) stood in the upright stance in four experimental conditions: no vision and no touch; vision and no touch; no vision and touch; and vision and touch. In the vision condition, participants looked at a target placed in front of them; in the no vision condition, participants wore a black cotton mask. In the touch condition, participants touched a stationary surface with their right index finger; in the no touch condition, participants kept their arms hanging alongside their bodies. A force plate was used to estimate center of pressure excursion for both anterior-posterior and medial-lateral directions. MANOVA revealed that both the individuals with DS and the control subjects used vision and touch to reduce overall body sway, although individuals with DS still oscillated more than did the CS. These results indicate that adults with DS are able to use sensory information to reduce body sway, and they demonstrate that there is no difference in sensory integration between the individuals with DS and the CS.

Multiple nucleolus organizer regions in Leptodactylus mystacinus (Amphibia, Anura) and comments on its systematic position in the L fuscus group based on cytogenetic and molecular analyses

Specimens of Leptodactylus mystacinus from Brazil were karyotyped with conventional and differential staining. The 2n = 22 karyotype is similar to that found for the majority of the Leptodactylus, the karyotypic conservatism also confirmed by the similarity of the replication banding patterns with those previously described. L. mystacinus has a small amount of C-banded heterochromatin, located mainly at the centromeres, although telomeric or interstitial bands have also been noticed. With DA/CMA(3) some chromosome regions showed slightly bright fluorescence, and with DA/DAPI, no particular AT-rich repetitive region was observed. Silver staining showed an extensive inter- and intraindividual variation in the number and position of Ag-positive regions, in 1p, 4p, 8p, 8q, and 11p. Nevertheless, FISH using rDNA probes confirmed only the signals on the short arms of chromosomes 4 and 8 as true NORs. The remaining silver stained regions are probably due to the heterochromatin with some affinity to the Ag-staining. Phylogenetic analysis based on partial cytochrome b sequence revealed that L. mystacinus forms a basal branch, so that the presence of multiple NORs in pairs 4 and 8 in this species indicates an autapomorphy.

Chromosomal differentiation of populations of Lysapsus limellus limellus, L. l. bolivianus, and of Lysapsus caraya (Hylinae, Hylidae)

Cytogenetic analysis were done on specimens from two populations of Lysapsus limellus limellus. three of L. l. bolivianus and of one of Lysapsus caraya. All animals showed a diploid chromosomal number of 2n=24. The karyotypes of the two L. limellus subspecies were very similar, differing only by the larger amount of telomeric heterochromatin and a small pericentromeric C-band on the short arms of pair 2 in L. l. limellus specimens. The karyotype of L. caraya differed from those of the two L. limellus subspecies in terms of chromosomal morphology, C-banding pattern and location of the main NOR on chromosomes 7 and 6. respectively. The karyotype of the L. l. bolivianus population from Guajara-Mirim/RO differed from those of the other populations of the same subspecies in morphology and heterochromatin pattern of chromosomes 7 and 8. Additional NORs were detected by silver staining and confirmed by FISH in one of the homologues of pairs 1 and 8 in L. l. bolivianus and in pair 7 in L. caraya. These results suggest that a reassessment of the taxonomic status of L. limellus subspecies, especially of the L. l. bolivianus populations, may be necessary. (c) 2005 Elsevier Ltd. All rights reserved.

Assignment of chromosome rearrangements between X chromosomes of human and cattle by laser microdissection and Zoo-FISH

Cross-species fluorescence in-situ hybridization (Zoo-FISH) was performed on cattle metaphase spreads using Homo sapiens X chromosome (HSAX) painting probes specific for the p- and q-arms to identify the cytogenetic location of a chromosome breakpoint between HSAX and the Bos taurus X chromosome (BTAX). The existence of a breakpoint is strongly suggested by recent radiation hybrid and FISH mapping results. Hybridization probes were generated by microdissection of HSAX p- and q-arms using the contact-free technology of Laser Microdissection and Pressure Catapulting (LMPC), amplification of the isolated chromosome material by DOP-PCR, and labelling of the PCR products with digoxigenin in a secondary PCR. Independent Zoo-FISH of the two painting probes on bovine metaphase chromosomes (detected by antidigoxigenin-fluorescein) resulted in clear hybridization signals on BTAX. A breakpoint was identified between HSAXp and HSAXq on BTAX, and narrowed down between the G-bands BTAXq25 and BTAXq26. The assumed centromere transposition between HSAX and BTAX associated with the rearranged chromosome segments is supported by cytogenetic assignments of the genes BGN and G6PD to BTAX.

Branch formation in Pulvinularia suecica (Nostocales, Cyanoprokaryota) and considerations on the classification of dichotomously and pseudodichotomously branched genera

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Comparative genomic hybridization analysis detects frequent over-representation of DNA sequences at 3q, 7p, and 8q in head and neck carcinomas

Comparative genomic hybridization (CGH) was used to identify chromosomal imbalances in 19 samples of squamous cell carcinoma of the head and neck (HNSCC). The chromosome arms most often or er-represented were 3q (48%), 8q (42%), and 7p (32%); in many cases, these changes were observed at high copy number. Other commonly over-represented sites were 1q, 2q, 6p, 6q, and 18q. The most frequently under-represented segments were 3p and 22q. Loss of heterozygosity of two polymorphic microsatellite loci from chromosome 22 was observed in two tongue tumors, in agreement with the CGH analysis. Gains of 1q and 2q material were detected in patients exhibiting a clinical history of recurrence and/or metastasis followed by terminal disease. This association suggests that gain of 1q and 2q map be a new marker of head and neck tumors with a refractory clinical response. (C) 2000 Elsevier B.V. All rights reserved.

Antiulcer activity and subacute toxicity of trans-dehydrocrotonin from Croton cajucara

The antiulcerogenic activity of trans-dehydrocrotonin (DHC), a nor-clerodane diterpene isolated from Croton cajucara Benth. ( Euphorbiaceae), and its subacute ( 35 days) toxicity were studied in mice and rats, respectively. For the antiulcerogenic tests, models of gastric ulcers induced in mice by ethanol/HCl or stress were used. In both models, an oral dose of DHC ( 100 mg/kg) significantly reduced (P< 0.01) the formation of gastric lesions. DHC was also tested for its ability to scavenge free radicals, but no such action was observed in rat liver mitochondria. To assess the subacute toxicity, rats were treated orally with DHC (25, 50 and 100 mg/kg) for 5 weeks. A significant increase in liver weight was observed in male and female rats at highest doses, whereas a significant reduction in plasma alkaline phosphatase and cholesterol levels and an increase in gamma glutamyl transpeptidase were observed only at the highest dose ( 100 mg/kg) in female rats. DHC caused histopathological alterations in the liver that included a turbid tumefaction, microvacuolar degeneration and nuclear alterations. Despite the beneficial antiulcerogenic activity of DHC, our results suggest that the long-term use of this compound may induce liver damage.

Gastroprotective activity of Pradosia huberi on experimentally induced gastric lesions in rodents: Role of endogenous sulphydryls and nitric oxide

Pradosia huberi is a medicinal plant very common in the Amazonian forest population. The research interest in this plant is justifiable because of its potential medicinal value in gastritis and gastric ulcer mentioned in local folk medicine. In this paper, we evaluated the acute toxicity and antiulcerogenic effect of a hydroalcoholic extract (HAE) obtained from Pradosia huberi barks in rodents. No acute toxicological sign or symptom was observed in animals treated with the highest dose (5000 mg/kg, p.o.) of Pradosia huberi. In the HCl/EtOH-induced gastric ulcer model, HAE demonstrated significant inhibition of the ulcerative lesion index by 73% (500 mg/kg) and 88% (1000 mg/kg), respectively, in relation to the control value (p < 0.05). The gastric damage induced by absolute ethanol in rats was effectively reduced by 84, 88 and 81% (250, 500 and 1000 mg/kg) when compared with the control group (p < 0.01). In the NSAID-induced lesion model, HAE also showed antiulcerogenic effect with decrease in gastric lesions of 56% (250 mg/kg), 57% (500 mg/kg) and 67% (1000 mg/kg) when compared with animals treated with vehicle (p < 0.05). In the gastric ulcer induced by pylorus ligature model, the administration of HAE by oral and intraduodenal routes inhibited the gastric lesion index by 79 and 52% (500 mg/kg), respectively. HAE administered orally or intraduodenally was able to change gastric juice parameters (pH, volume and acid output) as well as those treated with cimetidine. The treatment with HAE (p.o.) significantly increased gastric volume, the pH values and promoted reduced acid output (1) < 0.01). By comparative effect (intraduodenal and oral route), we observed that HAE was better for local activity in gastric mucosa than in systemic action. HAE also has a non-specific activity when found to be the inhibitor of intestinal motility (p > 0.01). The mechanism of action of HAE did not seem to be related to the NO-inhibitor but showed the participation of endogenous sulphydryl group in the gastroprotective action. (C) 2005 Elsevier B.V.. All rights reserved.

X chromosome heterochromatic pattern and nucleolar synthesis in pupal ovaries of Aedes aegypti

C-banding and silver-staining techniques were used to examine pupal ovaries of Aedes aegypti from Sao Jose do Rio Preto (Brazil). Silver staining in ovary cystocytes showed two basic patterns relative to the nucleolar morphology: viz (1) a single, compact small body; and (2) multiple bodies encompassing large nuclear areas. These two types of cystocytes were present in the ratio of 7:1, which is the same as the number of nurse cells and oocytes, respectively, in each follicle. This suggests the possibility of eventually using such a nucleolar morphological difference to recognize both cell types in developmental stages before emergence. Silver nitrate staining in metaphase chromosomes revealed centromeric bands on all six chromosomes. The C-banding pattern in metaphase chromosomes showed an intercalary band in one of the X arms, as described previously in other populations. In ovary cystocytes (pachytene stage) this C-positive band seemed to consist of two chromomeres. Phase contrast microscopy showed that the nucleolus was associated with the distal chromomere of this intercalary C-band, indicating that the nucleolus organizer region was located in that part of the heterochromatic band.

Effect of electrolytic and neurotoxic lesions of the median raphe nucleus on anxiety and stress

To study the role played by 5-HT mechanisms of the MRN, behavioural and physiological parameters were presently measured in rats having either electrolytic or 5,7-dihydroxytryptamine (5,7-DHT) lesion of the MRN made 7 days before testing. Half the animals were submitted to 2-h restraint 24 h before the test. In the elevated plus-maze, the electrolytic lesion increased the percentage of open-arm entries and of time spent on open arms - an anxiolytic effect - in both restrained and nonrestrained rats. The neurotoxic lesion had a similar effect, but only on restrained rats. Restraint had anxiogenic effect. The electrolytic lesion increased transitions between the light and dark compartments and the time spent in the bright compartment of the light-dark box in both restrained and nonrestrained rats. The neurotoxic lesion only increased bright time in restrained rats. The incidence, number and size of gastric ulcers were increased by either the electrolytic or the neurotoxic lesion in both restrained and nonrestrained animals. Both types of lesion depleted 5-HT in the hippocampus in restrained and nonrestrained rats. Restraint increased 5-HT levels. These results implicate 5-HT mechanisms of the median raphe nucleus in the regulation of anxiety and in the genesis of gastric stress ulcers. (C) 2001 Elsevier B.V. All rights reserved.

Implication of the 5-HT(2A) and 5-HT(2C) (but not 5HT(1A)) receptors located within the periaqueductal gray in the elevated plus-maze test-retest paradigm in mice

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Contrasting effects of acute and chronic treatment with imipramine and fluoxetine on inhibitory avoidance and escape responses in mice exposed to the elevated T-maze

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Environmentally induced antinociception and hyperalgesia in rats and mice

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

A GEOGRAPHICAL REPRESENTATION IN Coats of arms of LATIN AMERICA

This article seeks to reflect on geographic representation in the coats of arms of countries in Latin America, showing how the physical, aspects of the landscape, the elements of the economy and the republican symbols were used by local elites to compose an imaginary nation in the nineteenth century. This process of "naturalization of territory" was used as an important feature in the national discourse, because this time, in most cases, the Latin American nations were composed of multi-ethnic states, with strong differences of class and a large illiterate population plus a very tenuous territory from the point of view of national integration. Thus, the elements related to geographic image through the use of coats of arms, conveyed strong messages to citizens, showing how these heraldic symbols can become an important source of research to unravel the process of building the imaginary nation.

Constitutive heterochromatin, G-bands and nucleolus-organizer regions in four species of Didelphidae (Marsupialia)

Chromosomes of Didelphis albiventris, D. marsupialis, Philander opossum and Lutreolina crassicaudata, four species of marsupials with very similar karyotypes and 2n=22 were studied. All the chromosomes were acrocentrics except the X in L. crassicaudata, which is a metacentric. The G-band patterns of these species are similar but the distribution of constitutive heterochromatin differs among them as shown by C-banding. The hypothesis that the X in L. crassicaudata might be an isochromosome derived from the acrocentric X in the other species is discarded since G-and C-banding patterns differ in the two arms. In D. marsupialis the Ag-NORs are terminal and located in both arms of one pair and in the long arms of two pairs of medium-sized autosomes. In P. opossum the NOR-bearing chromosomes could be precisely identified through simultaneous silver staining and G-banding. The Ag-NORs are terminal and located at the short arm of pair 5 and the long arm of pair 7. © 1982 Dr W. Junk Publishers.