Reproductive development and function of female rats exposed to di-eta-butyl-phthalate (DBP) in utero and during lactation

Phthalates are environmental contaminants used in the production of plastics, cosmetics and medical devices. Studies on the effects of phthalates on female reproductive health are particularly sparse and mostly restricted to high-dose exposure in rats. In the present study, pregnant rats were treated with 100 mg/kg-d of di-eta-butyl-phthalate (DBP) or only the vehicle (control group), from GD 12 to GD 20 for evaluation of reproductive outcomes and fetal gonads analysis (F0), and from GD 12 to PND 21 to evaluate reproductive development and function on F1 female offspring. Results showed that all parameters were comparable between groups, although there was a significant increase in the fetal weight after DBP exposure. However, the body weight at birth was normal. Based on these data we can conclude that, in these experimental conditions, DBP did not disturb the reproductive development or function of female rats. (C) 2009 Elsevier Inc. All rights reserved.

Development of the osteoblastic phenotype in human alveolar bone-derived cells grown on a collagen type I-coated titanium surface

The aim of this study was to evaluate the development of the osteoblastic phenotype in human alveolar bone-derived cells grown on collagen type I-coated titanium (Ti) surface (Col-Ti) obtained by plasma deposition acrylic acid grafting compared with machined Ti (M-Ti). Osteoblastic cells were cultured until subconfluence and subcultured on Col-Ti and M-Ti for periods of up to 21 days. Cultures grown on Col-Ti and M-Ti exhibited similar cell morphology. Cell adhesion, total protein content, and alkaline phosphatase (ALP) activity were not affected by Ti surface modification in all evaluated periods. Growth analyses indicated that there were significantly more cells in cultures grown on Col-Ti at day 3. Runt-related transcription factor 2 (Runx2), osteopontin (OPN), and osteoprotegerin (OPG) mRNA expression of cells subcultured on Col-Ti was higher, whereas collagen type I (COL) was lower compared with M-Ti. Ti surface modification neither affected the osteocalcin (OC), ALP and receptor activator of NF-kappa B ligand (RANKL) mRNA expression nor the calcium content extracted from mineralized matrix. These results demonstrated that Col-Ti favours cell growth during the proliferative phase (day 3) and osteoblastic differentiation, as demonstrated by changes in mRNA expression profile during the matrix mineralization phase (day 14), suggesting that this Ti surface modification may affect the processes of bone healing and remodelling. To cite this article:Assis AF, Beloti MM, Crippa GE, de Oliveira PT, Morra M, Rosa AL. Development of the osteoblastic phenotype in human alveolar bone-derived cells grown on a collagen type I-coated titanium surface.Clin. Oral Impl. Res. 20, 2009; 240-246.doi: 10.1111/j.1600-0501.2008.01641.x.

Effects of a mixture of growth factors and proteins on the development of the osteogenic phenotype in human alveolar bone cell cultures

Strategies to promote bone repair have included exposure of cells to growth factor (GF) preparations from blood that generally include proteins as part of a complex mixture. This study aimed to evaluate the effects of such a mixture on different parameters of the development of the osteogenic phenotype in vitro. Osteoblastic cells were obtained by enzymatic digestion of human alveolar bone and cultured under standard osteogenic conditions until subconfluence. They were subcultured on Thermanox coverslips up to 14 days. Treated cultures were exposed during the first 7 days to osteogenic medium supplemented with a GFs + proteins mixture containing the major components found in platelet extracts [plate I et-derived growth factor-BB, transforming growth factor (TGF)-beta 1, TGF-beta 2, albumin, fibronectin, and thrombospondin] and to osteogenic medium alone thereafter. Control cultures were exposed only to the osteogenic medium. Treated cultures exhibited a significantly higher number of adherent cells from day 4 onward and of cycling cells at days 1 and 4, weak alkaline phosphatase (ALP) labeling, and significantly decreased levels of ALP activity and mRNA expression. At day 14, no Alizarin red-stained nodular areas were detected in cultures treated with GFs + proteins. Results were confirmed in the rat calvaria-derived osteogenic cell culture model. The addition of bone morphogenetic protein 7 or growth and differentiation factor 5 to treated cultures upregulated Runx2 and ALP mRNA expression, but surprisingly, ALP activity was not restored. These results showed that a mixture of GFs + proteins affects the development of the osteogenic phenotype both in human and rat cultures, leading to an increase in the number of cells, but expressed a less differentiated state.

The effects of information request ambiguity and construct incongruence on query development

This paper examines the effects of information request ambiguity and construct incongruence on end user's ability to develop SQL queries with an interactive relational database query language. In this experiment, ambiguity in information requests adversely affected accuracy and efficiency. Incongruities among the information request, the query syntax, and the data representation adversely affected accuracy, efficiency, and confidence. The results for ambiguity suggest that organizations might elicit better query development if end users were sensitized to the nature of ambiguities that could arise in their business contexts. End users could translate natural language queries into pseudo-SQL that could be examined for precision before the queries were developed. The results for incongruence suggest that better query development might ensue if semantic distances could be reduced by giving users data representations and database views that maximize construct congruence for the kinds of queries in typical domains. (C) 2001 Elsevier Science B.V. All rights reserved.

Temporal relationship between the auditory brainstem response and focal responses of auditory nerve root and cochlear nucleus during development in the tammar wallaby (Macropus eugenii)

Thirty-two pouch-young tammar wallabies were used to discover the generators of the auditory brainstem response (ABR) during development by the use of simultaneous ABR and focal brainstem recordings. A click response from the auditory nerve root (ANR) in the wallaby was recorded from postnatal day (PND) 101, when no central auditory station was functional, and coincided with the ABR, a simple positive wave. The response of the cochlear nucleus (CN) was detected from PND 110, when the ABR had developed 1 positive and 1 negative peak. The dominant component of the focal ANR response, the N-1 wave, coincided with the first half of the ABR P wave, and that of the focal CN response, the N-1 wave, coincided with the later two thirds. In older animals, the ANR response coincided with the ABR's N-1, wave, while the CN response coincided with the ABR's P-2, N-2 and P-3 waves, with its contribution to the ABR P-2 dominant. The protracted development of the marsupial auditory system which facilitated these correlations makes the tammar wallaby a particularly suitable model. Copyright (C) 2001 S. Karger AG, Basel.

Stressor categorization: acute physical and psychological stressors elicit distinctive recruitment patterns in the amygdala and in medullary noradrenergic cell groups

It has been hypothesized that the brain categorizes stressors and utilizes neural response pathways that vary in accordance with the assigned category. If this is true, stressors should elicit patterns of neuronal activation within the brain that are category-specific. Data from previous Immediate-early gene expression mapping studies have hinted that this is the case, but interstudy differences in methodology render conclusions tenuous. In the present study, immunolabelling for the expression of c-fos was used as a marker of neuronal activity elicited in the rat brain by haemorrhage, immune challenge, noise, restraint and forced swim. All stressors elicited c-fos expression in 25-30% of hypothalamic paraventricular nucleus corticotrophin-releasing-factor cells, suggesting that these stimuli were of comparable strength, at least with regard to their ability to activate the hypothalamic-pituitary-ad renal axis. In the amygdala, haemorrhage and immune challenge both elicited c-fos expression in a large number of neurons in the central nucleus of the amygdala, whereas noise, restraint and forced swim primarily elicited recruitment of cells within the medial nucleus of the amygdala. In the medulla, all stressors recruited similar numbers of noradrenergic (A1 and A2) and adrenergic (C1 and C2) cells. However, haemorrhage and immune challenge elicited c-fos expression In subpopulations of A1 and A2 noradrenergic cells that were significantly more rostral than those recruited by noise, restraint or forced swim. The present data support the suggestion that the brain recognizes at least two major categories of stressor, which we have referred to as 'physical' and 'psychological'. Moreover, the present data suggest that the neural activation footprint that is left in the brain by stressors can be used to determine the category to which they have been assigned by the brain.

Embryonic development of the nervous system of the temnocephalid flatworm Craspedella pedum

The nervous system of temnocephalid flatworms consists of the brain and three pairs of longitudinal connectives extending into the trunk and tail. The connectives are crosslinked by an invariant number of regularly spaced commissures. Branches of the connectives innervate the tentacles of the head and the sucker organ in the tail. A set of nerve rings encircling the pharynx and connected to the brain and connectives constitute the pharyngeal nervous system. The nervous system is formed during early embryogenesis when the embryo represents a multilayered mesenchymal mass of cells. Gastrulation and the formation of separate epithelial germ layers that characterize most other animal groups are absent. The brain arises as a bilaterally symmetric condensation of postmitotic cells in the deep layers of the anterior region of the embryonic mesenchyme. The pattern of axon outgrowth, visualized by labeling with anti-acetylated tubulin (acTub) antibody, shows marked differences from the pattern observed in other flatworm taxa. in regard to the number of neurons that express the acTub epitope. Acetylated tubulin is only expressed in neurons that form long axon tracts. In other flatworm species, such as the typhloplanoid Mesostoma and the polyclad Imogine, which were investigated by us with the acTub antibody (Hartenstein and Ehlers [2000] Dev. Genes Evol. 210:399-415; Younossi-Hartenstein and Hartenstein [2000] Dev. Genes Evol. 210:383-398), only a small number of pioneer neurons become acTub positive during the embryonic period. By contrast, in temnocephalids, most, if not all, neurons express acTub and form long, large-diameter axons. Initially, the brain commissure, pharyngeal nerve ring, and the connectives are laid down. Commissural tracts and tentacle nerves branching off the connectives appear later. We speculate that the precocious differentiation of the nervous system may be related to the fact that temnocephalids move by muscle action, and possess a massive and complex muscular system when they hatch. In addition, they have muscular specializations such as the anterior tentacles and the posterior sucker that are used as soon as they hatch. By contrast, juveniles of Mesostoma and larvae of polyclads move predominantly by ciliary action that may not require a complex neural circuitry for coordination. (C) 2001 Wiley-Liss, Inc.

Contrasting models of land use regulation: Community, government and tourism development

This paper assesses the capacity of local communities and sub-national governments to influence patterns of tourism development, within the context of a globalizing economy. Through a comparison of the contrasting examples of Hawaii and Queensland, the paper indicates the consequences of different approaches to land use regulation. It points to the importance of planning and policy processes that integrate community interests, in order to achieve long-term, sustainable tourism development. Effective regulation of development can minimize the social and environmental impacts of tourism. The paper illustrates how community organizations and sub-national governments can articulate local interests, despite the global demands of investors for more deregulated markets in land.

Functional development of the inferior colliculus (IQ and its relationship with the auditory brainstem response (ABR) in the tammar wallaby (Macropus eugenii)

To discover the developmental relationship between the auditory brainstem response (ABR) and the focal inferior colliculus (IC) response, 32 young tammar wallabies were used, by the application of simultaneous ABR and focal brainstem recordings, in response to acoustic clicks and tone bursts of seven frequencies. The ic or the tammar wallaby undergoes a rapid functional development from postnatal day (PND) 114 to 160. The earliest (PND 114) auditory evoked response was recorded from the rostral IC. With development, more caudal parts of the IC became functional until age about PND 127, when all parts of the IC were responsive to sound. Along a dorsoventral direction, the duration of the IC response decreased, the peak latency shortened, while the amplitude increased, reaching a maximum value at the central IC, then decreased. After PND 160, the best frequency (BF) of the ventral IC was the highest, with values between 12.5 and 16 kHz, the BF of the dorsal IC was the lowest, varying between 3.2 and 6.4 kHz, while the BF of the central IC was between 6.4 and 12.5 kHz. Between PND 114 and 125, the IC response did not have temporal correlation with the ABR. Between PND 140 and 160, only the early components of the responses from the ventral and central IC correlated with the P4 waves of the ABR. After PND 160, responses recorded from different depths of the IC had a temporal correlation with the ABR. (C) 2001 Published by Elsevier Science B.V.

Development, reliability, and concurrent validity of the modified inventory of potential reconstructive needs

Documentation of burn sequelae can be a difficult and time-consuming task. To date a reliable and systematic format for recording postburn trauma is lacking. The purpose of this research was two-fold: first, to develop a Modified Inventory of Potential Reconstructive Needs from the original Inventory of Potential Reconstructive Needs to allow methodical documentation of functional and cosmetic burn sequelae in all body surface areas of children with burns and, second, to establish interrater reliability and concurrent validity of the instrument, thus allowing its clinical application. Two raters scored the Modified Inventory of Potential Reconstructive Needs on 41 children with a range of burns types and severity. Excellent interrater reliability was demonstrated for both total (intraclass correlation coefficient = 0.996) and subsection inventory scores. Concurrent validity was also established with total scores showing strong positive correlations (0.73-0.76) with three indicators of burn severity. These findings provide initial support for the tool's clinical applicability, particularly in relation to rehabilitative planning and documentation.