Radiologist participation in multi-disciplinary teams in breast cancer improves reflective practice, decision making and isolation.

This study aims to explore Australian radiologists' experiences of participating in breast cancer multi-disciplinary team (MDT) meetings to identify enablers and barriers to participation as well their perception of confidence and patient care. Qualitative methods incorporating observation and interviews were used. Twenty-one breast cancer MDT meetings were observed across Sydney to study the dynamics of the meetings, the level of participation by radiologists and their most important interactions. Qualitative semi-structured interviews were conducted with 10 radiologists participating in these meetings regarding participation, educational opportunities and improvements to work practices. Radiologists' participation in breast cancer MDT meetings is influenced by the type of meeting they attend with higher levels of participation and a more dominant 'valued' role being evident in pre-interventional meetings. The key themes to emerge from the data include the importance of 'sharing experiences', the 'radiologist-pathologist relationship' and the value of 'continuing participation'. Radiologists believed their confidence in their clinical decision making increased when there was immediate feedback from pathologists. This study highlights the benefits of radiologists regularly participating in breast cancer MDT meetings in terms of continuing professional education resulting from collegial experiential learning. Radiologists' perceived patient care and workplace isolation were improved by sharing experiences with other cancer care colleagues.

Phenotypic integration in flowers of neotropical lianas: diversification of form with stasis of underlying patterns.

Phenotypic integration is essential to the understanding of organismal evolution as a whole. In this study, a phylogenetic framework is used to assess phenotypic integration among the floral parts of a group of Neotropical lianas. Flowers consist of plant reproductive organs (carpels and stamens), usually surrounded by attractive whorls (petals and sepals). Thus, flower parts might be involved in different functions and developmental constraints, leading to conflicting selective forces. We found that Bignonieae flowers have very similar patterns of variance/covariance among traits and that such patterns are uncorrelated with the phylogenetic relationships between species. However, in spite of pattern stasis, our results also indicate that diversification of floral morphology in this group has occurred throughout the evolution of magnitudes of correlation among traits. Thus, we suggest that stabilizing selection has played an important role in phenotypic integration, resulting in the long-term stasis of covariance patterns underlying flower diversification during the ca. 50 Myr of evolution of Bignonieae. This is the first report of long-term stasis in the phenotypic integration of angiosperms, suggesting that patterns of floral morphology can be recognizable as specific attributes of distinct botanical families.

Does the Bleaching Gel Application Site Interfere With the Whitening Result? A Randomized Clinical Trial.

This study aimed to evaluate the effect of the bleaching gel application site on chromatic changes and postoperative sensitivity in teeth. Thirty patients were selected and allocated to three groups (n=10 per group), according to the location of the gel: GI, cervical application; GII, incisal application; and GIII, total facial. The amount and time of application of the 35% hydrogen peroxide (H2O2) gel were standardized. Color changes were analyzed by ΔE and Wid (bleaching index), using the values obtained in the readings conducted on a digital spectrophotometer in the cervical (CRs) and incisal regions (IRs) of the teeth. Spontaneous sensitivity was assessed using the questionnaire, and the stimulated sensitivity caused by the thermosensory analysis (TSA). The analysis occurred in five stages: baseline, after the first, second, and third whitening sessions (S), and 14 days after the end of the whitening, using the linear regression statistical model with mixed effects and post-test by orthogonal contrasts (p<0.05). Although the IR was momentarily favored, at the end of the treatment, the restriction of the application site provided results similar to those obtained when the gel was applied over the entire facial surface. Regarding sensitivity, only the GI showed spontaneous sensitivity. In the TSA, GIII had less influence on the threshold of the thermal sensation. It was concluded that the chromatic alteration does not depend on the gel application site. Spontaneous sensitivity is greater when the gel is concentrated in the cervical region (CR), and the teeth remain sensitized by thermal stimuli even after 14 days.

Influence of Different Dye Substances on the Effectiveness of Bleaching and H2O2 Diffusion.

This study aimed to evaluate the influence of different dye substances on the effectiveness of bleaching and hydrogen peroxide diffusion (HO). From 300 central bovine incisors, 160 enamel/dentin disks with similar E* values were selected. The specimens were distributed according to the pigment treatment. Aiming to standardize the chromatic change provided by the different pigments, the specimens from each group remained immersed in the pigment solutions for different times (32 specimens per group): DW - distilled water (Control group); BT - black tea; CO - coffee; SD - cola-based soft drink; and RW - red wine. After pigmentation and chromatic change value analysis, only 10 specimens from each group (n=10) were selected, so the chromatic alteration of all groups was similar (ΔE=8.36±0.5). The samples were subjected to bleaching treatment and diffused peroxide was quantified in a visible ultraviolet light spectrophotometer. Two more bleaching sessions were conducted to evaluate ΔE and the Whiteness Index for Dentistry (ΔWID). Concurrently, solutions were prepared with dye agents, and the same ΔE value was obtained in the teeth (ΔE=8.49±0.5). The solutions received a standardized amount of H2O2, being analyzed by a visible ultraviolet light spectrophotometer. Data analysis comprised variance and Tukey's tests (α=0.05). Higher H2O2 diffusion was observed in pigmented groups when compared with DW (p<0.05). The CO and RW groups had the highest ΔE values (p>0.05), meaning greater difficulty in responding to treatment. In relation to ΔWID, RW bleached less than the other groups after the third bleaching session (p<0.05), resembling only the SD group (p=0.467). However, 21 days after ending the bleaching treatment, only RW and CO had the lowest values (p=0.481). Analysis of the solutions revealed that only RW was altered by the peroxide (p<0.05). In conclusion, teeth pigmented with coffee and, mainly, red wine were more resistant to bleaching treatment, although all pigmentations favored increases in transenamel and transdentinal H2O2 penetration.

Weight loss induced by 6-month lifestyle intervention improves early endothelial activation and fibrinolysis in obese adolescents.

BACKGROUND: Adolescent obesity is associated with an increased risk of adult obesity and subsequent cardiovascular diseases. The present study aimed to assess the effect of weight loss after 6-month lifestyle intervention in obese adolescents on biomarkers of endothelial activation and fibrinolytic system. METHODS: Eighty-five obese adolescents aged 10 to 16 years were assigned to a 6-month lifestyle intervention and 61 completed the programme. We examined the effect of the intervention on adhesion molecules (selectin E, soluble intercellular adhesion molecule 1 and soluble vascular adhesion molecule 1) and fibrinolytic parameters [plasminogen activator inhibitor-1 (PAI-1) and fibrinogen]. Thirty-six lean adolescents were studied only at baseline as a comparison group. RESULTS: Compared with lean participants, obese adolescents at baseline demonstrated significantly higher levels of triglycerides, glucose, insulin, homeostasis model assessment, soluble intercellular adhesion molecule 1, PAI-1 and fibrinogen. After 6-month lifestyle intervention, those obese adolescents with decreased standard deviation score-body mass index (SDS-BMI) displayed significant decreases in insulin (19.2 ± 11.2 vs. 26.8 ± 13.2 mU/L, P≤ 0.01), homeostasis model assessment (4.24 ± 3.19 vs. 6.58 ± 4.08, P≤ 0.01), selectin E (100.2 ± 60.9 vs. 116.0 ± 69.0 ng/mL, P≤ 0.01) and PAI-1 (39.6 ± 38.0 vs. 51.8 ± 25.6 ng/mL, P≤ 0.05) with respect to the baseline levels. No changes in these parameters were observed in the obese adolescents with stable or increased SDS-BMI. The changes of triglycerides after intervention in subgroup with decreased SDS-BMI were significantly greater than those in subgroup with stable SDS-BMI. CONCLUSIONS: The present study demonstrated increased endothelial activation and impairment of the fibrinolytic system in early life, which is in part reversible by a 6-month lifestyle intervention.

Composted municipal waste effects on chemical properties of a Brazilian soil.

The spread of composted municipal waste (CMW) on land can be used for sustainable crop production. Nevertheless, heavy metals availability may be a problem. Therefore, the main objective of this study was to assess the impact of CMW disposal on heavy metal accumulation in soil and plants. The treatments consisted of an untreated plot (control) and four rates of CMW application. All plots were cultivated in succession of carrot, cauliflower, sweet corn, and radish. Cu and Pb significantly accumulated in the topsoil (0-5 cm) with a similar pattern in the depths of 5-10 cm and 10-20 cm. Cauliflower, for Fe and Cu, and radish, for Pb and Cu, had their tissue analysis significantly affected due to the increasing rates of application of CMW. Nevertheless, the levels of accumulation in both, soil and plant, are within permissible limits. The evidences provided by this experiment indicated that heavy metals are less likely to cause problems for the estimation of CMW loadings to Brazilian agricultural land.

Transforming growth factor-alpha (TGF-alpha) and epidermal growth factor-receptor (EGF-R) immunoreactivity in normal and pathologic brain.

Transforming growth factor alpha (TGF-alpha) and epidermal growth factor-receptor (EGF-R) immunoreactivity is observed in the majority of neurons, and in maturing astrocytes, in the developing and adult brain of humans and different species of animals. TGF-alpha and EGF-R co-localize in most neurons and maturing astrocytes, suggesting that most TGF-alpha-producing cells are EGF-R-expressing cells. TGF-alpha and EGF-R immunoreactivity decrease in damaged areas following different insults. However, EGF-R appears in reactive glia, mostly reactive astrocytes, within and surrounding the damaged areas. TGF-alpha and EGF-R immunoreactivity is found in neurons of patients affected by Alzheimer's disease and other forms of dementia, and in neurons of patients suffering from epilepsy owing to different causes, thus pointing to the conclusion that TGF-alpha does not play a significant role in these pathologies. However, EGF-R immunoreactivity occurs in reactive astrocytes and microglia in subacute but not chronic lesions in human cases. Since TGF-alpha is a membrane-anchored growth factor, which may be cleaved leading to the formation of soluble forms, and both the membrane-anchored and soluble forms have the capacity to activate the EGF-R, it is feasible that TGF-alpha in the nervous system may act upon EGF-R-containing neurons through different mechanisms. In addition to distant effects resulting from the release of soluble TGF-alpha, local effects may be produced by establishing direct cell-to-cell contacts (juxtacrine stimulation), or in cells expressing both TGF-alpha and EGF-R (autocrine stimulation).

Thyroid hormone regulates reelin and dab1 expression during brain development.

The reelin and dab1 genes are necessary for appropriate neuronal migration and lamination during brain development. Since these processes are controlled by thyroid hormone, we studied the effect of thyroid hormone deprivation and administration on the expression of reelin and dab1. As shown by Northern analysis, in situ hybridization, and immunohistochemistry studies, hypothyroid rats expressed decreased levels of reelin RNA and protein during the perinatal period [embryonic day 18 (E18) and postnatal day 0 (P0)]. The effect was evident in Cajal-Retzius cells of cortex layer I, as well as in layers V/VI, hippocampus, and granular neurons of the cerebellum. At later ages, however, Reelin was more abundant in the cortex, hippocampus, cerebellum, and olfactory bulb of hypothyroid rats (P5), and no differences were detected at P15. Conversely, Dab1 levels were higher at P0, and lower at P5 in hypothyroid animals. In line with these results, reelin RNA and protein levels were higher in cultured hippocampal slices from P0 control rats compared to those from hypothyroid animals. Significantly, thyroid-dependent regulation of reelin and dab1 was confirmed in vivo and in vitro by hormone treatment of hypothyroid rats and organotypic cultures, respectively. In both cases, thyroid hormone led to an increase in reelin expression. Our data suggest that the effects of thyroid hormone on neuronal migration may be in part mediated through the control of reelin and dab1 expression during brain ontogenesis.

Dscr1, a novel endogenous inhibitor of calcineurin signaling, is expressed in the primitive ventricle of the heart and during neurogenesis.

We have demonstrated that DSCR1 acts as a negative regulator of calcineurin-mediated signaling and that its transcript is overexpressed in the Down syndrome (DS) fetal brain. To evaluate the possible involvement of DSCR1 in DS, we have cloned the mouse gene and analyzed its expression pattern in the central nervous system (CNS). Early expression of Dscr1 is detected mainly in the heart tube and in the CNS in rhombomere 4 and the pretectum. From embryonic day 14.5 onwards, Dscr1 is widely distributed in the CNS but becomes more restricted as the brain matures. We confirmed its neuronal expression pattern in the adult, preferentially in Purkinje and pyramidal cells, by double labeling with glial fibrillary acidic protein. We also show that although Dscr1 is present in trisomy in the Ts65Dn mouse, the adult brain expression pattern is not significantly altered. This expression pattern indicated that Dscr1 is a developmentally regulated gene involved in neurogenesis and cardiogenesis and suggests that it may contribute to the alterations observed in these organ systems in DS patients.

Positive control wells: a potential answer to remote-area quality assurance of malaria rapid diagnostic tests.

Malaria rapid diagnostic tests (RDTs) are a potential breakthrough in the provision of accurate diagnosis in remote areas, but widescale use is hampered by uncertainty over accuracy under field conditions. Positive control wells, which contain recombinant malaria parasite antigen, are a novel method for addressing this need for quality assurance. The potential of a commercially available positive control well, reconstituted with blood, was assessed for use in routine monitoring of RDT sensitivity in a remote malaria-endemic region. When maintained at 4 degrees C, the wells produced a consistent level of parasite lactate dehydrogenase (pLDH) antigen activity, as detected by pLDH-detecting RDTs, but activity reduced after cumulative exposure to temperatures likely to be encountered over a few months in a malaria-endemic area. This limitation was successfully overcome in the field through centralized, controlled storage. Monitoring of RDT sensitivity was successfully incorporated into routine supervisory visits to remote clinics. However, improved temperature stability of the wells would enhance their potential. The threshold at which the wells' signal reduced RDT sensitivity requires further investigation. The wells show potential to overcome an important obstacle to the wide implementation of accurate parasite-based diagnosis and appropriate treatment. Further assessment of their place in malaria management is warranted.

Descrição anatômica da artéria carótida externa e seus ramos na preguiça-comum / Anatomical description of external carotid artery and its branches in sloth

Bradypus variegatus, espécie pertencente à família Bradypodidae e à superordem Xenarthra, pode ser considerada modelo biológico de caráter multidisciplinar. Assim, realizou-se um trabalho de descrição anatômica da artéria carótida externa (ACE) e dos seus ramos no bicho-preguiça B. variegatus. Utilizaram-se 10 animais adultos, sendo todos fêmeas, que foram submetidos à dissecação, constatando-se que a artéria (a.) carótida comum se bifurca, em externa e interna, no nível do primeiro anel traqueal. A ACE, então, segue estendendo-se até a maxila, onde emite ramos para a região temporal e para o polo posterior do olho. Em todos os animais estudados, foram observados sete ramos principais da ACE, que, segundo a sua origem e localização, foram denominados como a. auricular, a. lingual, a. facial, a. alveolar, a. inferior, a. temporal, a. maxilar e a. oftálmica. Os ramos maxilar e oftálmico correspondem aos terminais e os demais são ramos colaterais. Em 50% dos animais analisados, foi verificada a presença de anastomoses arteriais e 40% deles apresentaram o acréscimo de um ramo aos principais. Desses, 30% demonstraram a presença de um ramo traqueal e 10% de um ramo sublingual, sendo esses ramos colaterais.(AU)

Bradypus variegatus is a species belonging to the family Bradypodidae and superorder Xenarthra, which should be considered as a multidisciplinary biological model. Thus, an anatomical description of the external carotid artery (ACE) and its branches in sloth B. variegatus was studied. Ten adult animals, all of them female, were submitted to dissection, and it was observed that the common carotid artery (a.) bifurcates in external and internal at the level of the first tracheal ring. Then, ACE extends through the maxilla where it launches branches to the temporal region and posterior eye side. For all sampled animals, seven principal branches of ACE were observed, and according to their origin and location were denominated as auricular, lingual, facial, bottom alveolar, temporal, maxillary and ophthalmic arteries. The maxillary and ophthalmic branches correspond to the terminals and the other branches are collateral. Presence of arterial anastomoses was observed in 50% of the sampled animals and 40% of them had increase of a branch on the principal. In these, 30% had presence of one tracheal branch and 10% of a sublingual branch, considering these branches as collateral.(AU)

X-ray-induced cell death in the developing hippocampal complex involves neurons and requires protein synthesis.

Sprague-Dawley rats aged 1 or 15 days were irradiated with a single dose of 200 cGy X-rays and killed at different intervals from 3 to 48 hours (h). Dying cells were recognized by their shrunken and often fragmented nuclei and less damaged cytoplasm in the early stages. On the basis of immunocytochemical markers, dying cells probably represented a heterogeneous population which included neurons and immature cells. In rats aged 1 day the number of dying cells rapidly increased in the hippocampal complex with peak values 6 h after irradiation. This was followed by a gentle decrease to reach normal values 48 h after irradiation. The most severely affected regions were the subplate and the cellular layer of the subiculum, gyrus dentatus and hilus, and the stratum oriens and pyramidale of the hippocampus (CA1 more affected than CA2, and this more affected than CA3). X-ray-induced cell death was abolished with an injection of cycloheximide (2 micrograms/g i.p.) given at the time of irradiation. X-ray-induced cell death was not changed after the intraventricular administration of nerve growth factor (NGF; 10 micrograms in saline) at the time of irradiation. Cell death was not induced by X-irradiation in rats aged 15 days. These results indicate that X-ray-induced cell death in the hippocampal complex of the developing rat is subjected to determinate temporal and regional patterns of vulnerability; it is an active process mediated by protein synthesis but probably not dependent on NGF.

Alu-splice cloning of human Intersectin (ITSN), a putative multivalent binding protein expressed in proliferating and differentiating neurons and overexpressed in Down syndrome.

By Alu-splice PCR we have trapped two exons and subsequently identified the full length cDNA of a human gene, Intersectin (ITSN), which maps to chromosome 21q22.1 between markers D21S320 and D21S325. The gene has the potential to code for at least two different protein isoforms by alternative splicing (ITSN-L and ITSN-S). Intersectin exists with a high degree of similarity in flies, frogs and mammals, suggesting a conserved role in higher eukaryotes. Analysis of the expression pattern of human and mouse Intersectin detected mRNAs in all adult and foetal tissues tested, with the longer isoform present in brain. In situ hybridisation studies in the developing mouse brain showed ITSN expression in both proliferating and differentiating neurons. The genomic structure of ITSN was determined using the chromosome 21 sequences deposited in the public databases. The protein contains several known motifs which implicate ITSN in clathrin mediated endocytosis and synaptic vesicle recycling. The expression pattern of Intersectin in mouse brain, its presumed function and its overexpression in brains from Down syndrome patients, suggest that Intersectin may contribute in a gene dosage-dependent manner to some of the abnormalities of Down syndrome.

Postnatal development of parvalbumin immunoreactivity in the cerebral cortex of the cat.

Parvalbumin immunoreactivity in the developing neocortex of the cat progresses following specific laminar, areal, and, in a particular area, roughly anteroposterior gradients. Parvalbumin immunoreactivity first occurs in basket cells and later in chandelier neurons. Pyramid-like immunoreactive neurons are also transitorily observed from the second to the third week in layer V of the auditory association-related areas. Parvalbumin-immunoreactive neurons first appear in the primary somatosensory cortex and primary auditory and visual areas, followed by the primary motor and polysensory association areas and, finally, the auditory association areas and cortical areas related to the limbic system. In addition to cortical neurons, three fiber systems are immunolabeled with antiparvalbumin antibodies: thalamocortical, callosal, and ipsilateral corticocortical. Parvalbumin-immunoreactive thalamocortical fibers appear during the first month of postnatal life. Parvalbumin-immunoreactive callosal and ipsilateral corticocortical fibers are seen from the fourth postnatal week onward. Because all parvalbumin-immunoreactive cortical neurons in adulthood are nonpyramidal inhibitory cells, the present findings suggest that a number of ipsilateral corticocortical and callosal connections may be inhibitory.

Migrating neurons in the developing cerebral cortex of the mouse send callosal axons.

The presence of migrating callosal neurons during the development of the murine cerebral cortex was studied using biocytin and the lipophilic dye, 1,1'-dioctadecyl-3,3,3',3'-tetramethylindocarbocyanine perchlorate as retrograde tracers. After injections of biocytin in the presumptive somatosensory cortex of newborn mice which were analysed one day later, many anterogradely labelled fibres coursed towards the contralateral hemisphere through the corpus callosum. Retrogradely labelled callosal cells were also observed. Most callosal neurons corresponded to immature pyramidal cells. In addition, a few biocytin-labelled callosal neurons displayed extremely fusiform shapes, vertical orientation and a short, single process emerging from the apical side of the perikaryon. At the electron microscopic level, these cells had features identical to those described for migrating callosal neurons. Twenty-four hours after birth, these migrating neurons were almost exclusively observed in the upper, dense aspect of the cortical plate (presumptive layers II-III) and only very exceptionally in the infragranular layers. No retrogradely labelled cell resembling migrating neurons were noticed after injections on postnatal days 2 or 5. To study migrating callosal neurons at embryonic stages, crystals of the lipophilic dye were injected in the corpus callosum or the contralateral white matter in embryos aged 17, 18 and 19 days, corresponding to the initial development of the corpus callosum in mice. Whereas callosal migrating neurons were not detected at embryonic days 17 and 18, injections of the lipophilic dye on embryonic day 19 revealed the presence of labelled migrating neurons in the infragranular layers. To corroborate further that these cells are migrating neurons, [3H]thymidine was administered on embryonic days 16 and 17, and labelled mice were injected with biocytin on embryonic day 19 or the first postnatal day. Retrogradely labelled callosal neurons resembling migrating neurons were autoradiographically labelled. These results indicate that the specification of certain neuronal types and the emergence of their cell type-specific characteristics occur shortly after postmitotic neurons leave the ventricular zone, before being positioned within the cortical plate.

Transforming growth factor-alpha immunoreactivity in the developing and adult brain.

Transforming growth factor-alpha immunoreactivity is examined in the developing and adult brain of cats and rats, and in the adult human brain in cryostat sections immediately processed free-floating with a well-characterized monoclonal antibody which does not cross-react with epidermal growth factor. Transforming growth factor-alpha immunoreactivity is observed in neurons of the cerebral neocortex, subiculum, hippocampus, striatum, thalamus, amygdala, basal forebrain, mesencephalon, cerebellar cortex, dentate nucleus and brainstem during development and in adulthood. The intensity of the immunoreaction directly correlates with the size of the cytoplasm. Diffuse transforming growth factor-alpha immunoreactivity also occurs in the white matter of the cerebrum, cerebellum and brainstem in the kitten, but not in the adult cat. In addition to neurons, numbers of glial cells in the cerebellar white matter, brainstem and cerebral hemispheres during development, and a few glial cells in the cerebellar cortex, diencephalon, cerebral cortex and white matter in adults are strongly transforming growth factor-alpha immunoreactive. These results support the concept that transforming growth factor-alpha is widely distributed in the brain of mammals, localizes in both neurons and glial cells, and is development dependent. These findings also suggest that transforming growth factor-alpha may play a role in the developing and adult central nervous system.

Neuron regeneration reverses 3-acetylpyridine-induced cell loss in the cerebral cortex of adult lizards.

Systemic administration of the neurotoxin 3-acetylpyridine to adult lizards results in extensive loss of neurons in the medial cerebral cortex, other brain areas remaining largely unaffected. After the neurotoxic trauma, new cells are produced by mitotic division of cells in the ventricular wall. The new cells migrate along radial glial fibers and replace lost neurons in the medial cortex. Electron microscopic examination of cells labeled with [3H]thymidine confirms that the newly generated cells are neurons. Thus, neuron regeneration can occur in the cerebral cortex of adult lizards.

3-Acetylpyridine-induced degeneration and regeneration in the adult lizard brain: a qualitative and quantitative analysis.

The neurotoxin 3-acetylpyridine (3AP) produces highly selective neuronal damage in specific areas of the lizard brain. Following 3AP intoxication, proliferation and migration of replacement neurons born in the ventricular walls lead to regeneration of the lesioned areas. Earlier studies established the time course of 3AP-induced degeneration and subsequent regeneration in the medial cerebral cortex of adult lizards (Font, E., García-Verdugo, J.M., Alcántara, S. and Lopez-García, C., Neuron regeneration reverses 3-acetylpyridine-induced cell loss in the cerebral cortex of adult lizards, Brain Res., 551 (1991) 230-235 [13]). Complementary to our previous studies, we now provide a qualitative and quantitative account of the extent and distribution of neurotoxic damage in the brain as a whole of lizards treated with 3AP using Nissl and Golgi stains, a degeneration-sensitive reduced-silver method, and electron microscopy. Additionally, [3H]thymidine autoradiography was used to assess changes in the rate of neurogenesis caused by the 3AP treatment. Single doses of 3AP caused degenerative changes in all the cortical areas, anterior dorsal ventricular ridge, deep layers of the lateral cortex, lateral amygdaloid nucleus, and nucleus sphericus, while sparing other brain areas. The most frequent neuropathic change after 3AP treatment was clumping of the nuclear chromatin with formation of pyknotic nuclei. Occasionally, a second type of injury was observed in neurons of the cell layer of the dorsomedial cortex (DMC). 3AP also caused a conspicuous loss of dendritic spines in bipyramidal neurons of the dorsomedial and dorsal cortices possibly representing transneuronal degeneration. Numbers of [3H]thymidine-labeled cells were higher in lizards previously treated with 3AP than in controls. These results demonstrate that the neurotoxic lesion is capable of inducing an increase in the normal rate of adult neurogenesis. Whereas regeneration in the remaining areas was morphologically and histologically complete, in some animals, cell proliferation in the DMC resulted in formation of an abnormal cell plate.

Late appearance of parvalbumin-immunoreactive neurons in the rodent cerebral cortex does not follow an 'inside-out' sequence.

Parvalbumin (PARV), a Ca(2+)-binding protein believed to play a role in neuronal excitability, is contained in certain GABAergic inhibitory neurons of the cerebral cortex. Here we report that expression of PARV in the developing neocortex of rats and mice occurs with a sequence which does not follow the usual 'inside-out' gradient of cortical development. Thus, PARV-immunoreactive neurons appear first in layer V and only thereafter in the remaining cortical layers. An adult-like pattern of immunoreactivity is reached simultaneously in layers II-III and VIb. These observations indicate that the mechanisms regulating the functional maturation of PARV-containing inhibitory neurons are different from those that generally govern developmental processes in the cortex.

Parvalbumin and calbindin D-28K immunoreactivity in central ganglioglioma and dysplastic gangliocytoma of the cerebellum. Report of two cases.

Calbindin D-28K and parvalbumin immunocytochemistry were used in the study of central ganglionic cell tumors. Most neurons in the ganglioglioma were immunoreactive to calbindin D-28K, but a few cells were labeled with antibodies against parvalbumin. In contrast, most cells in dysplastic gangliocytoma of the cerebellum were parvalbumin immunoreactive, but fewer reacted with anti-calbindin antibodies. These latter cells had two or three dendrites with claw-shaped terminals and axons with recurrent collateral branches and varicose terminals filled with strings and buttons. These observations suggest that central ganglionic cell tumors, including dysplastic gangliocytoma of the cerebellum, are composed of neurons which, on the basis of their calcium-binding protein content, have particular metabolic and electrophysiological properties.