Exploring the utility of Geometric Morphometrics to analyse prehistoric hand stencils.

Hand stencils are a remarkable graphic expression in Prehistoric rock art, dating back to 42 ka BP. Although these stencils provide direct impressions of the artists' hands, the characterization of their biological profile (i.e., biological sex and age) is very challenging. Previous studies have attempted this analysis with traditional morphometrics (TM), whereas little research has been undertaken using Geometric Morphometrics (GM), a method widely used in other disciplines but only tentatively employed in rock art studies. However, the large variation in relative finger position in archaeological hands poses the question of whether these representations can be examined through GM, or, in contrast, if this creates an unmanageable error in the results. To address this issue, a 2D hand scans sample of 70 living individuals (F = 35; M = 35) has been collected in three standardized positions (n = 210) and digitized with 32 2D conventional landmarks. Results show that the intra-individual distance (mean Procrustes distance between Pos. 1-2 = 0.132; 2-3 = 0.191; 1-3 = 0.292) is larger than the inter-individual distance (mean in 1 = 0.122; 2 = 0.142; 3 = 0.165). Finally, it has been demonstrated that the relative finger positions, as well as the inclusion of all hand parts in the analysis, have an overshadowing effect on other variables potentially involved in the morphometric variability of the hand, such as biological sex.

Prior MRI-imaging impact of patients submitted to brachytherapy for prostate cancer.

INTRODUCTION: Brachytherapy for the treatment of prostate cancer is a well-established option. Use of Multiparametric Magnetic Resonance Imaging (mpMRI) for staging and diagnosis of prostate cancer has come to change the current paradigm. In this study we aim to assess the impact of performing mpMRI to evaluate the presence of extracapsular lesions before brachytherapy in patients with prostate cancer concerning biochemical recurrence and time to nadir. METHODS: Review data from 73 patients submitted to brachytherapy. The following factors were evaluated: age, initial PSA, MRI local staging results, ISUP, nadir, time to nadir, PSA at one-year, biochemical recurrence, and time to recurrence. RESULTS: Median age was 68 years (51-72) and median follow-up 53 months (30-72). Concerning imaging modality 30,1% (n = 22) patients performed mpMRI. In the mpMRI group, 90.9% (n = 20) had at least one suspect lesion on mpMRI. Time to nadir was 27 months (3-64) in patients where mpMRI was not performed and 23.5 months (2-48) in patients submitted to mpMRI (P = .244). The median value of nadir was 0.42 ng/mL (<0.001-2) in patients submitted to mpMRI and vs 0.28 ng/mL (<0.001-4) in patients without MRI (P = .062) Recurrence utilizing Phoenix criteria was 9% (n = 2) in patients with MRI and 9.2% (n = 5) without mpMRI (P = .456), median follow-up of 43 months (12-72) for the MRI group with 58 months (30-78) for the non-mpMRI group. Both groups were statistically similar. CONCLUSION: Our results allow us to conclude that in our series MRI did not influence biochemical recurrence, time to nadir, or nadir value.

Deep evolutionary lineages in a Western Mediterranean snake (Vipera latastei/monticola group) and high genetic structuring in Southern Iberian populations.

Phylogeographic studies during the last decade confirmed an internal complexity of the Iberian Peninsula and northern Maghreb as refugial areas during the Miocene to Pleistocene period. Species with low vagility that experienced the complex climatic and palaeogeographic processes occurred in the Western Mediterranean Basin are excellent candidates to study the extent of lineage diversification in this region. We applied phylogenetic analyses based on mitochondrial data to infer the evolutionary history of Vipera latastei/monticola and identify the major biogeographic events structuring the genetic diversity within this group. We obtained a well-resolved phylogeny, with four highly divergent lineages (one African and three Iberian) that originated in the Tertiary. Coalescence-based estimations suggest that the differentiation of the four major lineages in V. latastei/monticola corresponds to the Messinian salinity crisis and the reopening of the Strait of Gibraltar during the Miocene. Subsequent Pliocene and Pleistocene climatic oscillations continued to isolate both Iberian and Maghrebian populations and led to a high genetic structuring in this group, particularly in Southern Iberia, a complex palaeogeographic and topographic region with high endemism levels. This study does not support the current taxonomy of the group, thus suggesting that an integrative evaluation of Iberian and African populations is needed to resolve its systematics.

Skeletal muscle expresses the extracellular cyclic AMP-adenosine pathway.

BACKGROUND AND PURPOSE: cAMP is a key intracellular signalling molecule that regulates multiple processes of the vertebrate skeletal muscle. We have shown that cAMP can be actively pumped out from the skeletal muscle cell. Since in other tissues, cAMP efflux had been associated with extracellular generation of adenosine, in the present study we have assessed the fate of interstitial cAMP and the existence of an extracellular cAMP-adenosine signalling pathway in skeletal muscle. EXPERIMENTAL APPROACH: cAMP efflux and/or its extracellular degradation were analysed by incubating rat cultured skeletal muscle with exogenous cAMP, forskolin or isoprenaline. cAMP and its metabolites were quantified by radioassay or HPLC, respectively. KEY RESULTS: Incubation of cells with exogenous cAMP was followed by interstitial accumulation of 5'-AMP and adenosine, a phenomenon inhibited by selective inhibitors of ecto-phosphodiesterase (DPSPX) and ecto-nucleotidase (AMPCP). Activation of adenylyl cyclase (AC) in cultured cells with forskolin or isoprenaline increased cAMP efflux and extracellular generation of 5'-AMP and adenosine. Extracellular cAMP-adenosine pathway was also observed after direct and receptor-dependent stimulation of AC in rat extensor muscle ex vivo. These events were attenuated by probenecid, an inhibitor of ATP binding cassette family transporters. CONCLUSIONS AND IMPLICATIONS: Our results show the existence of an extracellular biochemical cascade that converts cAMP into adenosine. The functional relevance of this extracellular signalling system may involve a feedback modulation of cellular response initiated by several G protein-coupled receptor ligands, amplifying cAMP influence to a paracrine mode, through its metabolite, adenosine.

The limits of mtDNA phylogeography: complex patterns of population history in a highly structured Iberian lizard are only revealed by the use of nuclear markers.

Phylogeographic analyses based on the sole use of the mitochondrial DNA (mtDNA) molecule reveal only a small part of the evolutionary history of a species or a set of related species. In this study, we have combined the application of slow- and fast-evolving nuclear markers (proteins and microsatellites, respectively) together with the analysis of two-gene genealogies to further understand the history of the Iberian endemic Schreiber's green lizard, Lacerta schreiberi, a species for which a well established phylogeographical scenario is available. In sharp contrast with the observation of four divergent and almost allopatric mtDNA clades, our nuclear data revealed how two groups of populations diverged, persisted and began to admix along the mountains of the Iberian Central System. In addition, the combination of mtDNA and nuclear data showed how the core area of the species distribution responded to ice ages, first by relatively old processes of population expansion to the south followed by episodes of contraction that are at the origin of present-day isolates, and more recently by a postglacial expansion to the Iberian Northwest where new habitats were made available after climatic amelioration. Taken together with recently published results for a variety of other organisms, our results suggest that complex processes of fragmentation, expansion and admixture can only be properly addressed through the use of several and complementary types of molecular markers. Finally, we also suggest that southern European refugia are both hotspots and melting pots of genetic diversity.

Bioaccumulation behaviour of transplants of the lichen Flavoparmelia caperata in relation to total deposition at a polluted location in Portugal.

This experiment compares the short and long time element accumulation behaviour of transplants of Flavoparmelia caperata lichen thalli and total deposition in an atmospheric polluted area. It was found that lichens exposed for a short time behaved differently from lichens in cumulative exposition suggesting the presence of acclimatization behaviour. The lichen transplant elemental content does not unequivocally represent the average or cumulative environmental availability of the exposure period. Reflection characteristics depend on the element and the lichen physiological conditions. Good correlations between lichen elemental contents and total deposition were obtained when a physiological lichen parameter was introduced in a mathematical model, suggesting that metabolically mediated accumulation is important.

Toward reliable population estimates of wolves by combining spatial capture-recapture models and non-invasive DNA monitoring.

Decision-makers in wildlife policy require reliable population size estimates to justify interventions, to build acceptance and support in their decisions and, ultimately, to build trust in managing authorities. Traditional capture-recapture approaches present two main shortcomings, namely, the uncertainty in defining the effective sampling area, and the spatially-induced heterogeneity in encounter probabilities. These limitations are overcome using spatially explicit capture-recapture approaches (SCR). Using wolves as case study, and non-invasive DNA monitoring (faeces), we implemented a SCR with a Poisson observation model in a single survey to estimate wolf density and population size, and identify the locations of individual activity centres, in NW Iberia over 4,378 km2. During the breeding period, posterior mean wolf density was 2.55 wolves/100 km2 (95%BCI = 1.87-3.51), and the posterior mean population size was 111.6 ± 18.8 wolves (95%BCI = 81.8-153.6). From simulation studies, addressing different scenarios of non-independence and spatial aggregation of individuals, we only found a slight underestimation in population size estimates, supporting the reliability of SCR for social species. The strategy used here (DNA monitoring combined with SCR) may be a cost-effective way to generate reliable population estimates for large carnivores at regional scales, especially for endangered species or populations under game management.

Genotype by feed interaction for feed efficiency and growth performance traits in pigs.

A major objective of pork producers is to reduce production cost. Feeding may account for over 75% of pork production costs. Thus, selecting pigs for feed efficiency (FE) traits is a priority in pig breeding programs. While in the Americas, pigs are typically fed high-input diets, based on corn and soybean meal (CS); in Western Europe, pigs are commonly fed diets based on wheat and barley with high amounts of added protein-rich coproducts (WB), e.g., from milling and seed-oil industries. These two feeding scenarios provided a realistic setting for investigating a specific type of genotype by environment interaction; thus, we investigated the genotype by feed interaction (GxF). In the presence of a GxF, different feed compositions should be considered when selecting for FE. This study aimed to 1) verify the presence of a GxF for FE and growth performance traits in different growth phases (starter, grower, and finisher) of 3-way crossbred growing-finishing pigs fed either a CS (547 boars and 558 gilts) or WB (567 boars and 558 gilts) diet; and 2) to assess and compare the expected responses to direct selection under the 2 diets and the expected correlated responses for one diet to indirect selection under the other diet. We found that GxF did not interfere in the ranking of genotypes under both diets for growth, protein deposition, feed intake, energy intake, or feed conversion rate. Therefore, for these traits, we recommend changing the diet of growing-finishing pigs from high-input feed (i.e., CS) to feed with less valuable ingredients, as WB, to reduce production costs and the environmental impact, regardless of which diet is used in selection. We found that GxF interfered in the ranking of genotypes and caused heterogeneity of genetic variance under both diets for lipid deposition (LD), residual energy intake (REI), and residual feed intake (RFI). Thus, selecting pigs under a diet different from the diet used for growing-finishing performance could compromise the LD in all growth phases, compromise the REI and RFI during the starter phase, and severely compromise the REI during the grower phase. In particular, when pigs are required to consume a WB diet for growing-finishing performance, pigs should be selected for FE under the same diet. Breeding pigs for FE under lower-input diets should be considered, because FE traits will become more important and lower-input diets will become more widespread in the near future.

Genetic correlations between feed efficiency traits, and growth performance and carcass traits in purebred and crossbred pigs.

Selection for feed efficiency (FE) is a strategy to reduce the production costs per unit of animal product, which is one of the major objectives of current animal breeding programs. In pig breeding, selection for FE and other traits traditionally takes place based on purebred pig (PB) performance at the nucleus level, while pork production typically makes use of crossbred animals (CB). The success of this selection, therefore, depends on the genetic correlation between the performance of PB and CB (rpc) and on the genetic correlation (rg) between FE and the other traits that are currently under selection. Different traits are being used to account for FE, but the rpc has been reported only for feed conversion rate. Therefore, this study aimed 1) to estimate the rpc for growth performance, carcass, and FE traits; 2) to estimate rg between traits within PB and CB populations; and 3) to compare three different traits representing FE: feed conversion rate, residual energy intake (REI), and residual feed intake (RFI). Phenotypes of 194,445 PB animals from 23 nucleus farms, and 46,328 CB animals from three farms where research is conducted under near commercial production conditions were available for this study. From these, 22,984 PB and 8,657 CB presented records for feed intake. The PB population consisted of five sire and four dam lines, and the CB population consisted of terminal cross-progeny generated by crossing sires from one of the five PB sire lines with commercially available two-way maternal sow crosses. Estimates of rpc ranged from 0.61 to 0.71 for growth performance traits, from 0.75 to 0.82 for carcass traits, and from 0.62 to 0.67 for FE traits. Estimates of rg between growth performance, carcass, and FE traits differed within PB and CB. REI and RFI showed substantial positive rg estimates in PB (0.84) and CB (0.90) populations. The magnitudes of rpc estimates indicate that genetic progress is being realized in CB at the production level from selection on PB performance at nucleus level. However, including CB phenotypes recorded on production farms, when predicting breeding values, has the potential to increase genetic progress for these traits in CB. Given the genetic correlations with growth performance traits and the genetic correlation between the performance of PB and CB, REI is an attractive FE parameter for a breeding program.

Disentangling the photochemical salinity tolerance in Aster tripolium L.: connecting biophysical traits with changes in fatty acid composition.

A profound analysis of A. tripolium photochemical traits under salinity exposure is lacking in the literature, with very few references focusing on its fatty acid profile role in photophysiology. To address this, the deep photochemical processes were evaluated by Pulse Amplitude Modulated (PAM) Fluorometry coupled with a discrimination of its leaf fatty acid profile. Plants exposed to 125-250 mm NaCl showed higher photochemical light harvesting efficiencies and lower energy dissipation rates. under higher NaCl exposure, there is evident damage of the oxygen evolving complexes (OECs). On the other hand, Reaction Centre (RC) closure net rate and density increased, improving the energy fluxes entering the PS II, in spite of the high amounts of energy dissipated and the loss of PS II antennae connectivity. Energy dissipation was mainly achieved through the auroxanthin pathway. Total fatty acid content displayed a similar trend, being also higher under 125-250 mm NaCl with high levels of omega-3 and omega-6 fatty acids. The increase in oleic acid and palmitic acid allows the maintenance of the good functioning of the PS II. Also relevant was the high concentration of chloroplastic C16:1t in the individuals subjected to 125-250 mm NaCl, related with a higher electron transport activity and with the organization of the Light Harvesting Complexes (LHC) and thus reducing the activation of energy dissipation mechanisms. All these new insights shed some light not only on the photophysiology of this potential cash-crop, but also highlight its important saline agriculture applications of this species as forage and potential source of essential fatty acids.

Spatial assessment of wolf-dog hybridization in a single breeding period.

Understanding the dynamics of wolf-dog hybridization and delineating evidence-based conservation strategies requires information on the spatial extent of wolf-dog hybridization in real-time, which remains largely unknown. We collected 332 wolf-like scats over ca. 5,000km2 in the NW Iberian Peninsula to evaluate wolf-dog hybridization at population level in a single breeding/pup-rearing season. Mitochondrial DNA (MtDNA) and 18 ancestry informative markers were used for species and individual identification, and to detect wolf-dog hybrids. Genetic relatedness was assessed between hybrids and wolves. We identified 130 genotypes, including 67 wolves and 7 hybrids. Three of the hybrids were backcrosses to dog whereas the others were backcrosses to wolf, the latter accounting for a 5.6% rate of introgression into the wolf population. Our results show a previously undocumented scenario of multiple and widespread wolf-dog hybridization events at the population level. However, there is a clear maintenance of wolf genetic identity, as evidenced by the sharp genetic identification of pure individuals, suggesting the resilience of wolf populations to a small amount of hybridization. We consider that real-time population level assessments of hybridization provide a new perspective into the debate on wolf conservation, with particular focus on current management guidelines applied in wolf-dog hybridization events.

Ectopic development of skeletal muscle induced by subcutaneous transplant of rat satellite cells.

The present study analyzes the ectopic development of the rat skeletal muscle originated from transplanted satellite cells. Satellite cells (10(6) cells) obtained from hindlimb muscles of newborn female 2BAW Wistar rats were injected subcutaneously into the dorsal area of adult male rats. After 3, 7, and 14 days, the transplanted tissues (N = 4-5) were processed for histochemical analysis of peripheral nerves, inactive X-chromosome and acetylcholinesterase. Nicotinic acetylcholine receptors (nAChRs) were also labeled with tetramethylrhodamine-labeled alpha-bungarotoxin. The development of ectopic muscles was successful in 86% of the implantation sites. By day 3, the transplanted cells were organized as multinucleated fibers containing multiple clusters of nAChRs (N = 2-4), resembling those from non-innervated cultured skeletal muscle fibers. After 7 days, the transplanted cells appeared as a highly vascularized tissue formed by bundles of fibers containing peripheral nuclei. The presence of X chromatin body indicated that subcutaneously developed fibers originated from female donor satellite cells. Differently from the extensor digitorum longus muscle of adult male rat (87.9 +/- 1.0 microm; N = 213), the diameter of ectopic fibers (59.1 microm; N = 213) did not obey a Gaussian distribution and had a higher coefficient of variation. After 7 and 14 days, the organization of the nAChR clusters was similar to that of clusters from adult innervated extensor digitorum longus muscle. These findings indicate the histocompatibility of rats from 2BAW colony and that satellite cells transplanted into the subcutaneous space of adult animals are able to develop and fuse to form differentiated skeletal muscle fibers.

Effect of microsatellite selection on individual and population genetic inferences: an empirical study using cross-specific and species-specific amplifications.

Although whole-genome sequencing is becoming more accessible and feasible for nonmodel organisms, microsatellites have remained the markers of choice for various population and conservation genetic studies. However, the criteria for choosing microsatellites are still controversial due to ascertainment bias that may be introduced into the genetic inference. An empirical study of red deer (Cervus elaphus) populations, in which cross-specific and species-specific microsatellites developed through pyrosequencing of enriched libraries, was performed for this study. Two different strategies were used to select the species-specific panels: randomly vs. highly polymorphic markers. The results suggest that reliable and accurate estimations of genetic diversity can be obtained using random microsatellites distributed throughout the genome. In addition, the results reinforce previous evidence that selecting the most polymorphic markers leads to an ascertainment bias in estimates of genetic diversity, when compared with randomly selected microsatellites. Analyses of population differentiation and clustering seem less influenced by the approach of microsatellite selection, whereas assigning individuals to populations might be affected by a random selection of a small number of microsatellites. Individual multilocus heterozygosity measures produced various discordant results, which in turn had impacts on the heterozygosity-fitness correlation test. Finally, we argue that picking the appropriate microsatellite set should primarily take into account the ecological and evolutionary questions studied. Selecting the most polymorphic markers will generally overestimate genetic diversity parameters, leading to misinterpretations of the real genetic diversity, which is particularly important in managed and threatened populations.

Short- and long-term influences of calcitonin gene-related peptide on the synthesis of acetylcholinesterase in mammalian myotubes.

The present study analyses the short- (15 min - 2 h) and long-term (24 - 48 h) influences of calcitonin gene-related peptide (CGRP) on acetylcholinesterase (AChE) expression in the rat cultured skeletal muscle and the signal transduction events underlying CGRP actions. To assess the effect of CGRP on AChE synthesis, myotubes were pre-exposed to the irreversible AChE inhibitor diisopropyl fluorophosphate (DFP) and treated with CGRP or forskolin, an adenylyl cyclase (AC) activator. Treatment of myotubes with 1 - 100 nM CGRP for 2 h increased by up to 42% the synthesis of catalytically active AChE with a parallel increase in the intracellular cyclic AMP. The stimulation of AChE synthesis induced by CGRP was mimicked by direct activation of AC with 3 - 30 microM forskolin. In contrast, pre-treatment of cultures with 100 nM CGRP for 20 h reduced by 37% the subsequent synthesis of AChE, resulting in a 15% decrease in total AChE activity after 48 h CGRP treatment. Moreover, 24 h treatment of myotubes with 100 nM CGRP reduced by 54% the accumulation of cyclic AMP induced by a subsequent CGRP treatment. These findings indicate that, in skeletal muscle cells, CGRP modulates the AChE expression in a time-dependent manner, initially stimulating the enzyme synthesis through a cyclic AMP-dependent mechanism. The decreased AChE synthesis observed after long-term CGRP treatment suggests that CGRP signalling system is subject to desensitization or down-regulation, that might function as an important adaptative mechanism of the muscle fibre in response to long-term changes in neuromuscular transmission.

Evidence for activation of the tissue kallikrein-kinin system in nociceptive transmission and inflammatory responses of mice using a specific enzyme inhibitor.

The pharmacological activity of phenylacetyl-Phe-Ser-Arg-N-(2, 4-dinitrophenyl)-ethylenediamine (TKI), a tissue kallikrein specific inhibitor, was assessed using models of nociception and inflammation in mice. Injection of TKI (13.6 - 136 micromol kg(-1), i.p. or 41 - 410 micromol kg(-1), s.c.) produced a dose-related inhibition of the acetic acid-induced writhes (by 37 to 85% or 34 to 80%, respectively). The antinociceptive activity of TKI (41 micromol kg(-1), i.p.) was maximal after 30 min injection and lasted for 120 min. The effect was unaltered by pretreatment with naloxone (8.2 micromol kg(-1), s.c.) or bilateral adrenalectomy. TKI (41 and 136 micromol kg(-1), i.p.) produced a dose-related decrease of the late phase of formalin-induced nociception by 79 and 98%, respectively. At 136 micromol kg(-1), i.p., TKI also shortened the duration of paw licking in the early phase by 69%. TKI (41 and 136 micromol kg(-1), i.p.) also reduced the capsaicin-induced nociceptive response (by 51 to 79%). TKI (41 micromol kg(-1), i.p. or 410 micromol kg(-1), s.c.) reduced the oedematogenic response, from the second to the fifth hour after carrageenin injection by 36 to 30% or by 47 to 39%, respectively. Pretreatment with TKI (41 micromol kg(-1), i.p.) reduced the capsaicin-induced neurogenic inflammation in the mouse ear by 54%. It is concluded that TKI presents antinociceptive and antiinflammatory activities mediated by inhibition of kinin formation by tissue kallikrein in mice. The results also indicate that the tissue kallikrein-dependent pathway contributes to kinin generation in nociceptive and inflammatory processes in mice.

Globular and asymmetric forms of acetylcholinesterase in the rat levator ani muscle.

The endplate (+EP) and non-endplate (-EP) distribution of molecular forms of acetylcholinesterase (AChE) was compared in the dimorphic levator ani and diaphragm muscles from adult male rats. Enzyme activity was measured by the thiocholine method and AChE forms were separated on the basis of solubility in sodium phosphate buffer of different ionic strength. For the dimorphic levator ani muscle, total AChE activity was 324.6 +/- 18.9 nmol ASCh hydrolyzed min-1 muscle-1, 90% of which was globular and predominated in the -EP region (78%). The asymmetric forms were almost exclusively detected in the +EP region (9%). In diaphragm muscle, total AChE activity was 176.7 +/- 11.0 units; 66% was mainly globular and located in the -EP region (56%); the asymmetric forms (34%) were either in -EP (11%) or +EP (23%) regions. Thus, a greater proportion of globular form was present in the dimorphic levator ani muscle than in diaphragm muscle. In view of the control exerted by testosterone on dimorphic muscles, it is suggested that the greater synthesis of the globular form in the levator ani occurs under the trophic influence of testosterone.

Early and late influences of testosterone on acetylcholinesterase activity of skeletal muscles from developing rats.

1. The influence of perinatal and pubertal gonadal androgens on acetylcholinesterase (AChE) activity was studied in the hormone-sensitive levator ani (LA) and extensor digitorum longus (EDL) muscles of adult male rats (105 days). 2. The hormone was withdrawn by gonadectomy at various ages and the effects on AChE and weight were compared with those induced by chronic denervation of both muscles from adult rats. 3. Gonadectomy of infantile (2-30 days) rats prevented LA muscle growth, and reduced total AChE activity to values similar to those found in denervated muscles (15% of control). The EDL muscles were slightly affected and only in rats castrated on the 2nd postnatal day. 4. When the rats were castrated at puberty (45 days), LA muscle weight and total AChE activity were reduced to 20% and 18% of control values, respectively. 5. Gonadectomy of adult (60 and 75 days) rats led to atrophy of the LA muscle (to 29% of control) and reduced the total AChE activity (to 40% of control). 6. AChE activity per unit weight was reduced by 30% in rats castrated from 5 to 20 days of age, and increased by 30% in both LA and EDL muscles from rats castrated in adulthood. Gonadectomy before puberty prevented total AChE in the LA from increasing above the levels detected in chronically denervated muscles. 7. Gonadectomy after puberty reduced total AChE of the LA but never to the extent caused by muscle denervation. 8. It is concluded that testosterone regulates AChE in the LA by early priming of the motoneuron and by pubertal stimulation of enzyme synthesis, the synthesis being dependent on intact innervation.

Comparison of the efficacy of biodegradable and non-biodegradable scintillation liquids on the counting of tritium- and [14C]-labeled compounds.

The widespread use of H and 14C in research has generated a large volume of waste mixed with scintillation liquid, requiring an effective control and appropriate storage of liquid radioactive waste. In the present study, we compared the efficacy of three commercially available scintillation liquids, Optiphase HiSafe 3, Ultima-Gold AB (biodegradable) and Insta-Gel-XF (non-biodegradable), in terms of [14C]-glucose and [ H]-thymidine counting efficiency. We also analyzed the effect of the relative amount of water (1.6 to 50%), radioisotope concentration (0.1 to 100 nCi/ml), pH (2 to 10) and color of the solutions (samples containing 0.1 to 1.0 mg/ml of Trypan blue) on the counting efficiency in the presence of these scintillation liquids. There were few significant differences in the efficiency of 14C and H counting obtained with biodegradable or non-biodegradable scintillation liquids. However, there was an 83 and 94% reduction in the efficiency of 14C and H counting, respectively, in samples colored with 1 mg/ml Trypan blue, but not with 0.1 mg/ml, independent of the scintillation liquid used. Considering the low cost of biodegradable scintillation cocktails and their efficacy, these results show that traditional hazardous scintillation fluids may be replaced with the new safe biodegradable fluids without impairment of H and 14C counting efficiency. The use of biodegradable scintillation cocktails minimizes both human and environmental exposure to hazardous solvents. In addition, some biodegradable scintillation liquids can be 40% less expensive than the traditional hazardous cocktails.

Prevalence and impact of chronic otitis media in school age children in Brazil. First epidemiologic study concerning chronic otitis media in Latin America.

OBJECTIVE: The first epidemiological study carried out in Latin America to investigate the prevalence of otological disease and its impact in a representative random sample of the school children population. METHODS: A cross sectional epidemiological survey to investigate the epidemiology of otitis in a representative random sample of 1119 children and adolescents from a total of 486166 elementary and high-school students, aged 6-18 years, regularly registered in one of the 521 public and private schools of the city of Belo Horizonte, in the state of Minas Gerais, southern Brazil. The interviews were conducted individually, in the school, by an otolaryngologist or a pediatrician. The interview included all of the personal data and also detailed questions regarding otological disorders and hearing. The otological examination was carried out with Mini-Heine otoscopes and the audiometric evaluation with the AudioScope 3 with 25dB intensity. The questionnaire and basic procedures for medical examination had been previously tested through a pilot test in two schools. RESULTS: The prevalence of chronic otitis media was 0.94%. Impacted wax was found in 12.3% of the students. The prevalence of abnormalities (excluding wax) in the otoscopy examination was 10.5%. It was found that 8.3% of students had a past history of otitis and 7.7% had a past history of otorrhea. These two special groups presented statistically significant associations with chronic otitis media, hearing loss and otolaryngological surgeries (when compared with the other school children). Parents and school children seemed significantly able to identify a special group of children with past history of otitis during childhood.

Clinical and genetic linkage analysis of a large Venezuelan kindred with Usher syndrome.

OBJECTIVE: To undertake a comprehensive investigation into the very high incidence of congenital deafness on the Macano peninsula of Margarita Island, Venezuela. METHODS: Numerous visits were made to the isolated island community over a 4-year-period. During these visits, it became apparent that a significant number of individuals complained of problems with hearing and vision. Socioeconomic assessments, family pedigrees and clinical histories were recorded on standard questionnaires. All individuals underwent thorough otolaryngologic and ophthalmologic examinations. Twenty milliliters of peripheral venous blood was obtained from each participant. A genome-wide linkage analysis study was performed. Polymorphic microsatellite markers were amplified by polymerase chain reaction and separated on polyacrylamide gels. An ABI 377XL sequencer was used to separate fragments and LOD scores were calculated by using published software. RESULTS: Twenty-four families were identified, comprising 329 individuals, age range 1-80 years, including 184 children. All families were categorized in the lower two (least affluent) socioeconomic categories. A high incidence of consanguinity was detected. Fifteen individuals (11 adults, 4 children) had profound congenital sensorineural hearing loss, vestibular areflexia and retinitis pigmentosa. A maximum LOD score of 6.76 (Linkage >3.0), between markers D11s4186 and D11s911, confirmed linkage to chromosome 11q13.5. The gene myosin VIIA (MYO7A) was confirmed in the interval. Clinical and genetic findings are consistent with a diagnosis of Usher syndrome 1B for those with hearing and vision problems. CONCLUSIONS: We report 15 Usher syndrome 1B individuals from a newly detected Latin American socio-demographic origin, with a very high prevalence of 76 per 100,000 population.