First chromosomal analysis of Gymnorhamphichthys britskii: the remarkable lowest diploid value within the family Rhamphichthyidae (Gymnotiformes)

Gymnorhamphichthys britskii is a Neotropical electric fish of family Rhamphichthyidae described from the Paraná-Paraguay system. This study reports the first karyotypic description of G. britskii collected from the upper Paraná river basin, which presented 2n=38 chromosomes, karyotype composed of 14 metacentric, 8 submetacentric, 2 subtelocentric and 14 acrocentric chromosomes, and fundamental number as 62 for both sexes. Heteromorphic sex chromosomes were absent. A single pair of nucleolar organizing regions (NORs) was detected in the submetacentric chromosome pair number 9 by silver staining and confirmed by the 18S rDNA probe. The 5S rDNA was located in a single chromosome pair. Heterochromatic regions were clearly observed in the short arms of the NOR-bearing chromosome pair and in the telomeric positions of most acrocentric chromosomes. Besides the present data are valuable to help in understanding karyotypic evolution in Rhamphichthyidae, data from NORs confirmed the tendency of this family in presenting simple NORs sites, similar to the other Gymnotiformes clades. Yet, the presence of a large heterochromatic block in the NOR-bearing chromosome can be used as cytogenetic markers for G. britskii, and that centric fusions appear to be an important mechanism in the karyotype evolution and differentiation among Gymnotiformes species.(AU)

Gymnorhamphichthys britskii é um peixe neotropical da família Rhamphichthyidae descrita no sistema Paraná-Paraguai. Este estudo relata a primeira descrição cariotípica de G. britskii coletado na bacia do alto rio Paraná, que apresentou 2n = 38 cromossomos, cariótipo composto por 14 metacêntricos, 8 submetacêntricos, 2 subtelocêntricos e 14 acrocêntricos, e número fundamental 62 para ambos sexos. Cromossomos sexuais heteromórficos estavam ausentes. Um único par de regiões organizadoras de nucléolos (RONs) foi detectado no par de cromossomos submetacêntricos número 9 por coloração com prata e confirmado pela sonda DNAr 18S. O DNAr 5S foi localizado em um único par cromossômico. Regiões heterocromáticas foram claramente observadas nos braços curtos do par de cromossomos que carrega a RON e nas posições teloméricas da maioria dos cromossomos acrocêntricos. Além dos dados presentes serem valiosos para auxiliar na compreensão da evolução cariotípica em Rhamphichthyidae, dados de RONs confirmaram a tendência desta família em apresentar sítios simples de RONs, semelhantes aos demais clados de Gymnotiformes. No entanto, a presença de um grande bloco heterocromático no cromossomo portador da RON, pode ser usado como marcador citogenético para G. britskii e as fusões cêntricas parecem ser um mecanismo importante na evolução e diferenciação cariotípica entre as espécies de Gymnotiformes.(AU)

Effects of diabetes and hypertension on oral mucosa and tgfß1 salivary levels

Abstract The aim of this study was to investigate salivary levels of TGFβ1 and proliferation/ maturation of epithelial mucosa cells in diabetic and hypertensive patients. Design: in this cross-sectional study, whole stimulated saliva and oral mucosa exfoliative cytology specimens were collected from 39 patients that were healthy (control, n=10) or presented history of arterial hypertension (HAS, n=9), diabetes mellitus (DM, n=10) or both (DM+HAS, n=10). Salivary flow rate (SFR), TGFβ1 level in saliva, AgNORs and the epithelial maturation were evaluated. Non-parametric Kruskal-Wallis test, followed by Dunn's multiple comparison post-test and the Spearman test correlation analysis were used. SFR showed a significant decreased in DM and DM+HAS (0.47±0.11 and 0.64±0.43 mL/min) when compared to control (1.4±0.38 mL/min). DM+HAS presented the highest value of TGFβ1 concentration (24.72±5.89 pg/mL). It was observed a positive correlation between TGFβ1 and glycaemia (R=0.6371; p<0.001) and a negative correlation between TGFβ1 and saliva (R=-0.6162; p<0.001) and glycaemia and SFR (R=-0.5654; P=0.001). AgNORs number and status of maturation of mucosa cells were similar for all conditions. DM and DM+HAS presented the lowest SFR, which correlated with increased TGFβ1 levels. Despite the higher TGFβ1 secretion it was not observed changes in the morphology or proliferation of epithelial cells when diabetes or hypertension was present.

Resumo O objetivo deste estudo foi investigar os níveis de TGFβ1 na saliva e a proliferação/maturação das células epiteliais da mucosa em paciente diabéticos e hipertensos. Neste estudo transversal, saliva estimulada e amostras de citologia exfoliativa de mucosa oral foram coletadas de um total de 39 pacientes que se apresentavam saudáveis (controle, n=10) ou com história de hipertensão arterial (HAS, n=9), diabetes mellitus (DM, n=10) ou ambos (DM+HAS, n=10). Taxa de fluxo salivar (SFR), níveis de TGFβ1 na saliva, AgNORs e maturação epitelial foram avaliados. Teste não-paramétrico de Kruskal-Wallis, seguido de comparação múltipla de Dunn e correlação de Spearman foram utilizados para as análises. SFR diminuiu significantemente em DM e DM+HAS (0,47±0,11 e 0,64±0,43 mL/min) quando comparado ao controle (1,4±0,38 mL/min). DM+HAS apresentou os maiores valores de concentração de TGFβ1 (24,72±5,89 pg/mL). Foi observada uma correlação positiva entre TGFβ1 e glicemia (R=0,6371; p<0,001) e uma correlação negativa entre TGFβ1 e saliva (R=-0,6162; p<0,001) e glicemia e SFR (R=-0,5654; p=0,001). Número de AgNORs e o padrão da maturação das células epiteliais foram similares entre os todos grupos. DM e DM+HAS apresentaram os menores valores de SFR, os quais foram correlacionados com o aumento nos níveis de TGFβ1. Apesar da maior secreção de TGFβ1, não foram observadas mudanças na morfologia ou proliferação das células epiteliais quando o paciente apresentava diabetes ou hipertensão.

First chromosome data on Steindachneridion doceanum (Siluriformes: Pimelodidae): a critically endangered catfish endemic of the Doce River basin, Brazil

The present report represents the first cytogenetic description of Steindachneridion doceanum, great catfish which is currently at high extinction risk and it is listed as threatened on the red list of the Brazilian Ministry of the Environment, also are suggested karyotype relationships with other species of the same genus endemic from other river basins. The results revealed a diploid number of 2n = 56 and the karyotype composed of 18 metacentric, 20 submetacentric, 10 subtelocentric and 8 acrocentric chromosomes (NF = 104). The AgNORs and CMA3 signals were coincident in location occupying the short arm of an acrocentric chromosome pair (25th), in a secondary constriction. The 5S rDNA genes were localized on the short arms of one subtelocentric pair. C-banding revealed terminal blocks on the short arms on many chromosomes as well as terminal positive bands at the both ends of a submetacentric pair. C banding also revealed a large heterochromatic block in the secondary constriction (25th) region that was coincident with the AgNORs sites and CMA3+ bright bands. In spite S. doceanum represent an endemic taxon, in spite their geographic isolation their cytogenetic characteristics show similarities with other species of the genus.(AU)

O presente trabalho apresenta a primeira descrição citogenética de Steindachneridion doceanum, grande bagre que se encontra atualmente em alto risco de extinção e listado como ameaçado na lista vermelha do Ministério do Meio Ambiente, também sugere relações cariotípicas com outras espécies do mesmo gênero, endêmicas de outras bacias hidrográficas. Os resultados revelaram um número diplóide de 56 cromossomos e o cariótipo composto por 18 elementos metacêntricos, 20 submetacêntricos, 10 subtelocêntricos e 8 acrocêntricos (NF = 104). As marcações AgNORs e CMA3 foram coincidentes ocupando o braço curto de um par de cromossomos acrocêntricos (par 25), em uma constrição secundária. Os genes 5S rDNA foram detectados nos braços curtos de um par subtelocêntrico. A banda C revelou blocos terminais nos braços curtos em vários cromossomos, bem como blocos terminais nas duas extremidades de um par submetacêntrico. A banda C também evidenciou um grande bloco heterocromático na constrição secundária (par 25) coincidente com os sítios AgNORs e as bandas CMA3 positivas. Apesar de S. doceanum representar um táxon endêmico, suas características citogenéticas mostram semelhanças com outras espécies do gênero das quais se encontra geograficamente isolado.(AU)

Cellular proliferation markers in peripheral and central fibromas: a comparative study

ABSTRACT Objective: To perform a comparative study of the cellular proliferation in the peripheral and central fibromas. Material and Methods: Immunohistochemistry for PCNA and the AgNOR technique were performed in 9 cases of peripheral odontogenic fibroma (POF), in 4 cases of odontogenic fibroma (OdF), in 8 cases of peripheral ossifying fibroma (PEOF) and 7 cases of ossifying fibroma (OsF). The Kruskal-Wallis and Mann-Whitney tests were used for the statistical analyses. Results: Mesenchymal component of the central lesions presented a higher mean number of AgNOR per nucleus and PCNA index than did the peripheral lesions (P≤0.05). The mean number of AgNOR per nucleus in the epithelial component proved to be higher in the OdF than in the POF (P≤0.05). The mesenchymal and epithelial components presented similar mean numbers of AgNOR per nucleus and PCNA index in the OdF, as well as a similar mean number of AgNOR per nucleus in the POF. Conclusions: The mesenchymal component may well play a role in the differences between the biological behaviour of the central lesions as compared to the peripheral lesions. Moreover, considering that the epithelial and mesenchymal components in odontogenic fibromas presented a similar proliferation index, more research is warranted to understand the true role of the epithelial components, which are believed to be inactive in nature, as well as in the development and biological behaviour of these lesions. .

Argyrophilic nucleolar organizer regions expression in laryngeal squamous cell carcinoma and its & nbsp;relationship with clinical factors / 中国癌症杂志

10.3969/j.issn.1007-3969.2013.05.003

Relação entre a quantidade de AgNORS, atividade proliferativa e o estágio de desenvolvimento placentário em equinos / Relationship between the amount of AgNORs, proliferative activity and stage of placental development in horses

As Regiões Organizadoras de Nucléolo (NORs - nucleolar organizer regions) são utilizadas para descrever regiões de cromatina coradas por Nitrato de Prata e estão relacionados com a atividade de síntese de RNAr e com a agilidade e rapidez na proliferação celular nos tecidos estudados. O objetivo deste trabalho foi relacionar a quantidade de AgNORs, a atividade proliferativa e o estágio da gestação em equinos, utilizando a coloração de Nitrato de Prata. Os anexos embrionários foram coletados, fixados em solução de formaldeído tamponado 10%, emblocadas em paraplast e submetidos à coloração de Nitrato de Prata. Os grupos foram determinados de acordo com a idade gestacional. A quantidade de NORs encontrada no cório no começo da gestação indica início da atividade celular e na medida em que a gestação avança, a quantidade de NORs aumenta, sugerindo maior atividade de síntese e aumento da sua importância na manutenção do feto. Ao contrário do que ocorre no cório, a quantificação das NORs foram maiores no final da gestação do que no inicio, sugerindo a estabilização destas membranas no final da gestação. A cinta coriônica e o saco vitelino foram encontrados no início da gestação e apresentaram grande quantidade de NORs, sugerindo função de síntese e proliferação no inicio da gestação, visto que suas funções é manutenção do embrião até a formação completa da placenta verdadeira (cório-alantoide). Concluímos que as membranas que se desenvolvem de maneira progressiva de acordo com o crescimento embrionário/fetal (cório, alantoide e âmnio) têm aumento no número de NORs e as membranas que involuem após a formação do embrião/feto (saco vitelino e cinta coriônica) têm um decréscimo neste número, sugerindo a diminuição da atividade proliferativa nestas membranas.

The Nucleolar Organizer Regions (NORs - nucleolar organizer regions) are used to describe regions of chromatin stained with silver nitrate and are related to the activity of rRNA synthesis and to the agility and speed of cell proliferation in the tissues studied. The objective of this study was to relate the amount of AgNORs, proliferative activity and stage of pregnancy in horses, using the coloring of Silver Nitrate. The embryonic attachments were collected, fixed in 10% buffered formaldehyde, embedded in paraplast and stained by silver nitrate. The groups were determined according to the gestational age. The amount of the corium NOR found in early pregnancy indicates the onset of cell activity, and in that the pregnancy progresses, the amount of NOR increases, suggesting higher activity and increased synthesis of their importance in maintaining the fetus. Contrary to what occurs in the corium, the quantification of NORs was higher in late pregnancy than in the beginning, suggesting the stabilization of these membranes in late pregnancy. The chorionic girdle and the yolk sac were found in early pregnancy and had lots of NORs, suggesting synthesis function and proliferation in early pregnancy, since their functions is maintenance of the embryo until the complete formation of the true placenta (chorio-allantoic membranes). We conclude that the membranes that develop in a progressive manner in accordance with the growing embryo/fetal (chorion, amnion and allantoic membranes) have an increased number of NORs and the membranes that involute after the formation of the embryo/fetus (yolk sac and chorionic girdle) have a decrease in number, suggesting a reduction in proliferative activity in these membranes.

AgNORs Scoring in Benign Intermediate and Malignant Soft Tissue Tumor.

One of the most recent methods to determine the proliferative activity is silver stained nucleolar organizer region(AgNORs).The purpose of present study is by using mean AgNOR count per nucleus was found to be higher in benign soft tissue tumour as compared to apparently normal soft tissue and found to be statistically significant. An increase AgNOR score in benign, intermediate, malignant soft tissue tumour as compared to apparently normal soft tissue tumour. After histological confirmation, one more section was prepared which was subjected to AgNOR staining. Study was done in taking 32 benign, 05 intermediate and 23 malignant soft tissue. Benign soft tissue neoplasm which comprised 32 cases showed a range of mean AgNORs count 2.2-3.20 and intermediate group showed 3.10-4.61 and malignant group 4.90-6.70, so on comparing benign, intermediate and malignant group p value is found to be <0.0001. Hence results are statistically significant.

Cytogenetic description of Bunocephalus doriae Boulenger, 1902 (Siluriformes: Aspredinidae) from the Paraná River (Misiones, Argentina)

In this work, Bunocephalus doriae was cytogenetically analyzed. A karyotype with a diploid number of 2n= 50 comprising 6m, 10sm, 6st, and 28a (FN= 72) chromosomes was observed. The occurrence of an asymmetric karyotype with a large number of acrocentric chromosomes distinguishes this species from others the Order Siluriformes. An exclusive character observed is the first pair of subtelocentric as the largest chromosome pair of the complement. NORs detected using AgNO3 were located in the terminal regions, on the short arm of a subtelocentric chromosome pair (pair 11), in a secondary constriction. C-banding revealed heterochromatic centromeric regions on several chromosomes of the complement after C-banding. This is the first cytogenetic description of this species and the first cytogenetic report on a member of the family Aspredinidae.

No presente trabalho, Bunocephalus doriae. foi analisado citogeneticamente. O número diploide encontrado foi 2n= 50 compreendendo 6m, 10sm, 6st, and 28a (NF= 72) cromossomos. A ocorrência de um cariótipo assimétrico com um grande número de cromossomos acrocêntricos distingue esta espécie das demais pertencentes à Ordem Siluriformes e foi observada como característica exclusiva a presença do primeiro par subtelocêntrico, sendo o maior do complemento. As NORs detectadas pelo AgNO3 foram observadas na região terminal do braço curto de um par cromossômico subtelocêntrico (par 11), em uma constrição secundária. A heterocromatina, após o bandamento C, foi visualizada em regiões centroméricas de vários cromossomos do complemento. Esta é a primeira descrição citogenética desta espécie e a primeira descrição de um membro da família Aspredinidae.

Cytogenetic description of Bunocephalus doriae Boulenger, 1902 (Siluriformes: Aspredinidae) from the Paraná River (Misiones, Argentina)

In this work, Bunocephalus doriae was cytogenetically analyzed. A karyotype with a diploid number of 2n= 50 comprising 6m, 10sm, 6st, and 28a (FN= 72) chromosomes was observed. The occurrence of an asymmetric karyotype with a large number of acrocentric chromosomes distinguishes this species from others the Order Siluriformes. An exclusive character observed is the first pair of subtelocentric as the largest chromosome pair of the complement. NORs detected using AgNO3 were located in the terminal regions, on the short arm of a subtelocentric chromosome pair (pair 11), in a secondary constriction. C-banding revealed heterochromatic centromeric regions on several chromosomes of the complement after C-banding. This is the first cytogenetic description of this species and the first cytogenetic report on a member of the family Aspredinidae.

No presente trabalho, Bunocephalus doriae. foi analisado citogeneticamente. O número diploide encontrado foi 2n= 50 compreendendo 6m, 10sm, 6st, and 28a (NF= 72) cromossomos. A ocorrência de um cariótipo assimétrico com um grande número de cromossomos acrocêntricos distingue esta espécie das demais pertencentes à Ordem Siluriformes e foi observada como característica exclusiva a presença do primeiro par subtelocêntrico, sendo o maior do complemento. As NORs detectadas pelo AgNO3 foram observadas na região terminal do braço curto de um par cromossômico subtelocêntrico (par 11), em uma constrição secundária. A heterocromatina, após o bandamento C, foi visualizada em regiões centroméricas de vários cromossomos do complemento. Esta é a primeira descrição citogenética desta espécie e a primeira descrição de um membro da família Aspredinidae.

Análise proliferativa nas células trofoblásticas em bovinos / Proliferative analysis of trophoblastic cells in cattle

The aim of the present study was to evaluate the cell proliferative activity, by AgNORs number, in different regions of bovine placenta throughout gestation. A total of 28 bovine placentas were separated into four groups: group I (60 to 120 days), group II (121 to 170 days), group III (171 to 220 days), and group IV (221 to 290 days). It was found a greater number of AgNORs in giant trophoblastic cells (GTC) when compared with mononuclear trophoblastic cells (MTC) (p<0,001) in all regions and gestational groups analyzed, that confirms their intensive synthesis activity in trophoblast epithelium. The central region of the placentome begins an intense proliferative activity in group II, observed by clusters, while placentomes edges showed a higher number of clusters on group III. These data suggest that the central region of the placentomes began an intense proliferative activity prior to its edge, both declines at the end of pregnancy. Interplacentomal area showed a higher number of AgNORs in the group IV, suggesting a higher proliferative activity of these cells at the end of pregnancy. The results of this study indicate that the proliferative activity, as determined by the amount of intranuclear AgNORs, exhibits patterns that are not only specific to each type of trophoblastic cells, but also for each specific region of bovine placenta throughout pregnancy.

Este estudo teve como objetivo analisar atividade proliferativa das células trofoblásticas, através da quantificação de AgNORs, em diferentes regiões da placenta bovina ao longo da gestação. Foram utilizados 28 úteros, sendo estes agrupados de acordo com as idades gestacionais: grupo I (60-120 dias); II (121- 170 dias); III (171-220 dias) e IV (221-290 dias). Foi encontrado um número significativamente maior de AgNORs nas células trofoblásticas gigantes (CTG) em relação às mononucleadas (CTM) (p<0,001) em todas as regiões e grupos gestacionais analisados, o que confirma sua intensa atividade de síntese no epitélio trofoblástico. A região central do placentônio inicia uma atividade proliferativa mais intensa já no grupo II, observada pelo número de clusters, enquanto que a margem do placentônio apresenta uma maior quantidade de clusters no grupo III. Estes dados sugerem que a região central do placentônio inicia uma intensa atividade proliferativa anteriormente a sua margem, ambas declinando no final da gestação. A área interplacentomal apresentou um maior número de AgNORs no último grupo gestacional, sugerindo uma maior atividade proliferativa dessas células no final da prenhez. Os resultados deste estudo indicam que a atividade proliferativa, determinada pela quantidade de AgNORs intranucleares, exibe padrões que são específicos não somente para cada tipo de célula trofoblástica, mas também para cada região específica da placenta bovina ao longo da gestação.

Interspecific chromosomal divergences in the genus Characidium (Teleostei: Characiformes: Crenuchidae)

Karyotypes of seven fish species of the genus Characidium, three of them studied for the first time, were characterized using conventional cytogenetic techniques (Giemsa staining, Ag-NOR, and C-banding). All species presented a diploid number of 2n=50, with only metacentric and submetacentric chromosomes, as observed in all Characidium species studied. In two species cells with one to three B chromosomes were observed. All species analyzed have a single NOR-bearing chromosome pair with morphological differences among them. Characidium cf. zebra shows heterochromatic blocks restricted to the pericentromeric regions of all chromosomes denoting the absence of a sex chromosome system. On the other hand, the species Characidium lanei, C. pterostictum, C. lauroi, C. oiticicai, C. schubarti, and Characidium sp., besides presenting pericentromeric heterochromatic blocks, exhibited large interstitial and/or terminal heterochromatic blocks, and a ZZ/ZW sex chromosome system. The constitutive heterochromatin seems to play a relevant role in the chromosome differentiation process of the studied species, mainly in relation to the sex chromosomes. The geographical isolation of the rivers in which the species were sampled, associated with their way of life restricted to headwaters environments, may have favored the process of fixation of different karyotypes found in each of the analyzed species.

Os cariótipos de sete espécies de peixes do gênero Characidium, três estudadas pela primeira vez, foram caracterizados com o uso das técnicas citogenéticas convencionais (Giemsa, Ag-RONs e bandamento-C). Todas as espécies apresentaram número diplóide de 2n=50 cromossomos, com predominância de cromossomos dos tipos meta e submetacêntricos. Nesse estudo foi também observada a presença de até três cromossomos B em células de duas espécies, C. oiticicai e C. pterostictum. O bandamento C e o tratamento com nitrato de prata revelaram significativas diferenças nos cariótipos das espécies analisadas. A espécie Characidium cf. zebra apresenta heterocromatina restrita às regiões pericentroméricas dos cromossomos e ausência de heteromorfismos cromossômicos relacionados à diferenciação sexual, enquanto as espécies Characidium lanei, C. pterostictum, lauroi, C. oiticicai, C. schubarti e Characidium sp., evidenciaram, além de blocos pericentroméricos também observados em Characidium cf. zebra, grandes blocos heterocromáticos intersticiais e/ou terminais e sistema cromossômico de diferenciação sexual do tipo ZZ-ZW. A heterocromatina constitutiva parece exercer papel relevante no processo de diferenciação cromossômica destas espécies, principalmente em relação à diferenciação de cromossomos sexuais. O isolamento geográfico dos rios em que essas espécies foram amostradas, bem como o seu modo de vida restrito às regiões de cabeceira, podem ter favorecido o processo de diferenciação cromossômica e a fixação dos cariótipos particulares encontrados em cada uma das espécies analisadas.

Correlation of Nuclear Morphometry and AgNOR Score with Radiation Response in Squamous Cell Cancers of the Head and Neck: A Preliminary Study

Background: Prediction of radiation response before the completion of the radiotherapy schedule is challenging. Information about radiation response could help oncologist to choose the appropriate combination and sequence of therapies in the multidisciplinary management of cancer. Methods: The study involved 26 patients with squamous cell cancers of the head and neck region who received radiotherapy to a dose of 30 Gy in 10 fractions over a 2-week period as part of a split-course technique. Fine-needle aspiration cytology was performed on day 1 and day 5 of the schedule. The silver staining of the nuclear organiser region (AgNOR) and nuclear morphometric study were done on both days. Results: The median age of the patients was 44 years old. The primary tumours were distributed in the nasopharynx (n = 11), larynx and hypopharynx (n = 5), metastatic node (n = 4), and miscellaneous tumours were found in the head and neck sub sites (n = 6). The mean initial AgNOR score was 3.0, range 1.2–7.0. The median of nuclear and nucleolar diameters were 11.07 μm, range 7.70–16.6 μm, and 2.92 μm, range 1.09–11.66 μm, respectively. Patients with a pre-radiotherapy AgNOR score of greater than 2.5 were associated with disease progression and metastasis. However, the increased of nuclear diameter on day 5 compared with baseline predicted a good radiation response in patients (P = 0.016). Conclusion: Intra-radiotherapy nuclear morphometry combined with baseline AgNOR score could be a simple and useful tool for the prediction of radiation response in head and neck cancers.

Cytogenetic analysis of three sea catfish species (Teleostei, Siluriformes, Ariidae) with the first report of Ag-NOR in this fish family

Despite their ecological and economical importance, fishes of the family Ariidae are still genetically and cytogenetically poorly studied. Among the 133 known species of ariids, only eight have been karyotyped. Cytogenetic analyses performed on Genidens barbus and Sciades herzbergii revealed that both species have 2n = 56 chromosomes and Cathorops aff. mapale has 2n = 52 chromosomes: Genidens barbus has 10 Metacentrics (M), 14 Submetacentrics (SM), 26 Subtelocentrics (ST), and 6 Acrocentrics (A), Sciades herzbergii has 14M, 20SM, 18ST and 4A, whereas Cathorops aff. mapale has 14M, 20SM, and 18ST. The nucleolus organizer regions (NORs) were found in a single chromosome pair on the short arm of a large-sized ST pair in Genidens barbus and on the short arm of a middle-size SM pair in Cathorops aff. mapale. Multiple NORs on the short arms of two large-sized ST pairs were found in Sciades herzbergii. The occurrence of diploid numbers ranging from 2n = 52 through 56 chromosomes and the presence of different karyotypic compositions, besides the number and position of NORs suggest that several numeric and structural chromosome rearrangements were fixed during the evolutionary history of this fish family.

Quantitative AgNORs study in ameloblastomas / Análise quantitativa das AgNORs em ameloblastomas

Purpose: Ameloblastomas are tumors that arise from the odontogenic epithelium, including the areas that coat the dentigerous cysts (DC). The aim of the present study was to investigate the proliferative activity present in luminal and mural areas of mural unicystic ameloblastomas (MUA), in conventional ameloblastomas (CA), and in DC, comparing them according to their biological behavior. Methods: AgNOR quantifications were performed using routine light microscopy under X100 magnification in 10 cases per type of lesion, considering 100 cells of representative areas of the tumor for each case. The AgNORs were observed as black dots within the cell nucleus. Results: MUA showed significant lower number of NORs/nucleus in the luminal proliferation area than in the area of mural proliferation and in CA (P<0.05). Conclusion: CA exhibit proliferative activity similar to the mural component of MUA, corroborating the pattern of higher aggressive clinical behavior of these tumor variants.

Objetivo: Os ameloblastomas são tumores originados do epitélio odontogênico, inclusive daquele que reveste os cistos dentígeros (CD). O objetivo do presente trabalho foi avaliar a atividade proliferativa das áreas luminais e murais dos ameloblastomas unicísticos murais (AUM), ameloblastomas convencionais (AC) e cistos dentígeros (CD), comparando seus comportamentos biológicos. Metodologia: Para tanto foram selecionados 10 casos de AC, 10 casos de AUM e 10 amostras de CD. A análise quantificativa das AgNORs foi realizada através de microscopia ótica de rotina com aumento de 100X nos 10 casos de cada lesão estudada, analisando-se 100 células de áreas representativas do tumor. As AgNORs foram observadas como pontos pretos dentro do núcleo celular. Resultados: A média de NORs/núcleo da área de proliferação luminal do AUM foi estatisticamente inferior à da área de proliferação mural desta mesma lesão e à do AC (P<0,05); nenhuma outra diferença estatística foi encontrada. Conclusão: Conclui-se que os AC exibem atividade proliferativa semelhante à do componente mural do AUM, o que corrobora o padrão de comportamento clínico mais agressivo dessas variantes clínicas.

Karyology of the Atlantic forest rodent Juliomys (Cricetidae): a new karyotype from southern Brazil

Juliomys is a small rodent from the family Cricetidae which inhabits the Atlantic forest and forests from Argentina to eastern Brazil. The three species recognized so far have different karyotypes. In this paper, we describe a new karyotype with 2n = 32, FN = 48 found in Juliomys specimens from a high-altitude area in the Atlantic forest of southern Brazil. The karyotype was analyzed after G- and C-banding and silver staining of the nucleolus organizer regions (Ag-NOR) and its G-banding patterns were compared with those of the newly described species Juliomys ossitenuis (2n = 20, FN = 36). The 2n = 32 karyomorph presented peculiar features and was very different from those of the other species of the genus: J. pictipes (2n = 36, FN = 34), J. rimofrons (2n = 20, FN = 34) and J. ossitenuis (2n = 20, FN = 36). Differences were mostly due to centric and tandem fusions, pericentric inversion and loss of heterochromatin. The karyotype represents a powerful tool to differentiate Juliomys species and our data suggest that the karyotype described herein belongs to a new species.

Patterns of ribosomal DNA distribution in hylid frogs from the Hypsiboas faber and H. semilineatus species groups

We performed a comparative analysis of the nucleolus organizer region (NOR) distribution in the karyotypes of hylid frogs from two different taxonomic groups, Hypsiboas faber and H. semilineatus. Silver nitrate staining of NORs (Ag-NORs) and fluorescence in situ hybridization (FISH) with a rDNA probe were used to investigate the chromosomal location of rDNA loci in two species. The karyotype of H. semilineatus and the Ag-NORs distribution of the four species are presented herein for the first time. After conventional staining, the four species presented very similar karyotypes with 2n = 24, but Ag-NORs analyses revealed species-specific characteristics. H. albomarginatus, H. faber and H. semilineatus had one pair of interstitial Ag-NORs in the short arm of pairs 2, 11, and in the long arm of pair 7, respectively. H. pardalis presented telomeric NORs in the long arm of pair 11. Ag-NORs were heteromorphic in three of the species (H.pardalis, H. semilineatus and H. albomarginatus) and FISH confirmed the differential activity of rDNA genes in H. semilineatus. In the present study, 2n = 24 karyotypes could be distinguished by their Ag-NORs distribution. Our results further the knowledge about the cytogenetics of hylids from Brazil.

Estudo quantitativo e morfológico das regiões organizadoras de nucléolo coradas pela prata (AgNORs) em neoplasias benignas e malignas da glândula mamária da espécie canina / Quantitative and morphological study of silver staining nucleolar organizer regions (AgNORs) in benign and malignant neoplasms of the canine mammary gland

O alvo deste estudo foi apresentar um novo método de avaliação das regiões organizadoras de nucléolos (NORs), objetivando verificar a correlação entre malignidade das células tumorais com proliferação celular. Vinte e nove tumores foram analisados quanto aos aspectos morfológicos e quantitativos de regiões organizadoras de nucléolos coradas pela prata (AgNORs) e comparados à quatro glândulas mamárias normais utilizadas como controle. Os dados obtidos foram tratados pelos testes não-paramétrico de Kruskal-Wallis e ôUõ de Mann-Whitney. Os números médios de NORs dos grupos neoplásicos malignos incluindo carcinomas tubulares (2,14 ± 0,54), carcinomas papilíferos (1,79 ± 0,24) e carcinomas sólidos (1,95 ± 0,30) mostraram diferença significativa quando comparados ao grupo controle (1,16 ± 0,08). A análise morfológica das AgNORs mostrou que o padrão de apresentação da NORs do tipo I prevaleceu nos grupos neoplásicos benignos (75% dos casos de adenoma tubular e 50% dos casos de carcinoma tubular), enquanto o tipo II prevaleceu nos grupos neoplásicos de comportamento maligno (54,5 % dos carcinomas papilíferos e 100% dos carcinomas sólidos). O grupo controle mostrou na sua totalidade (100% dos casos) predominância de NORs do tipo IV. O padrão do Tipo III não predominou em nenhum dos grupos envolvidos neste estudo. A análise da morfologia das AgNORs é uma ferramenta útil na determinação do prognóstica de alterações neoplásicas da glândula mamária canina.

The aim of this study was try to present a new method of evaluation of the nucleolar organizer regions (NORs) being related its morphology and distribution, objectifying to verify the correlation between malignancy of tumoral cells with cellular proliferation. Twenty-nine tumors were analyzed with regard to quantitative and morphological aspects of the silver staining nucleolar organizer regions (AgNORs) and compared to four normal mammary glands used as control. The data obtained were submitted to non-parametric Kruskal- Wallis and Mann-Whitney ôUõ tests. The mean NORs counts of the malignant neoplastic groups tubular carcinomas (2.14 ± 0.54), papillary carcinomas (1.79 ± 0.24) and solid carcinomas (1.95 ± 0.30) showed significant difference when compared with the control group (1.16 ± 0.08). Morphological analysis of AgNORs revealed that the expression pattern of type I NORs predominate in the benign histological groups (75% of the tubular adenoma cases and 50% of the tubular carcinoma cases), whereas type II NORs pattern prevailed in the malignant behavior neoplastic groups (54,5% of the papillary carcinoma and 100% of the solid carcinoma cases). Control group showed total predominance (100% of the cases) of type IV NORs. Expression pattern of the type III NORs did not prevail in neither histological group encompassed by this study. Evaluation of AgNORs morphology reveals an useful tool for prognosis assessment of neoplastic alterations of the canine mammary gland.

Proliferação celular nos linfomas caninos / Cell proliferation in canine lymphoma

O estudo dos linfomas caninos além de abordar a classificação morfológica e imunofenotípica necessita ser ampliado para que se tenha a avaliação da cinética celular. Esta verificação só pode ser feita com segurança quando são avaliados os parâmetros que indicam a taxa de proliferação celular. No homem, estes fatores têm influência no prognóstico e no tratamento dos limfomas. Os 40 linfomas utilizados neste trabalho foram classificados de acordo com a classificação de Kiel e a imunofenotipagem utilizou CD3 (linfócitos T) e CD79a (linfócitos B). A proliferação celular foi avaliada pelos métodos de contagem dos AgNORs e Ki-67 (MIB-1) De acordo com a classificação de Kiel os linfomas de alto grau foram os mais freqüentes, a imunofenotipagem mostrou a mesma freqüência de linfomas T e B. Quando avaliada a proliferação celular houve diferença significativa entre os linfomas de alto e baixo grau tanto pelo método do AgNOR como do KI-67.(MIB-1), porém não foram estatisticamente entre os imunofenótipos Entre as neoplasias de alto grau de malignidade a média de número de NORs por núcleo de célula neoplásica foi de 1,37 ± 0,32, e nos casos de baixo grau de 0,98 ± 0,36, de acordo com o KI-67 a média do percentual de células positivas foi de 43,19% ± 19,01, e 14,09% ± 11,74 nos casos de alto e baixo grau, respectivamente.

Lymphoma studies deals with morphological classification and immunophenotypic features and they have to be amplified for cellular kinetics evaluation. This evaluation can only be safely made, when the proliferative index are evaluated. In men the proliferation index have, most of the time, important influence in the neoplasia prognosis and treatment In this work it was used 40 canine lymphomas that were classified according to Kiel methods and immunophenotype was achieved with CD3 (T lymphocyte) and CD79a (B lymphocyte). Cellular proliferation was evaluated by AgNORs and Ki-67 (MIB-1) According to Kiel classification system, high grade lymphomas were more frequent and T and B lymphoma showed the same frequency.When cellular proliferation was evaluated, there was a significant difference between high grade and low grade lymphomas by AgNOR and Ki-67 (MIB-1) methods, but did not differ when comparing immunophenotype. Among high grade malignancy lymphomas the NORs medium number per cell nucleoli was 1.37± 0.32 and in low grade was 0.98± 0.36, concerning Ki-67 the positive cellular percentual was 43.19% ± 19.01, e 14.09% ± 11.74 in high and low grade, respectively

Estudo quantitativo e morfológico das regiões organizadoras de nucléolo coradas pela prata (AgNORs) em neoplasias benignas e malignas da glândula mamária da espécie canina / Quantitative and morphological study of silver staining nucleolar organizer regions (AgNORs) in benign and malignant neoplasms of the canine mammary gland

O alvo deste estudo foi apresentar um novo método de avaliação das regiões organizadoras de nucléolos (NORs), objetivando verificar a correlação entre malignidade das células tumorais com proliferação celular. Vinte e nove tumores foram analisados quanto aos aspectos morfológicos e quantitativos de regiões organizadoras de nucléolos coradas pela prata (AgNORs) e comparados à quatro glândulas mamárias normais utilizadas como controle. Os dados obtidos foram tratados pelos testes não-paramétrico de Kruskal-Wallis e ôUõ de Mann-Whitney. Os números médios de NORs dos grupos neoplásicos malignos incluindo carcinomas tubulares (2,14 ± 0,54), carcinomas papilíferos (1,79 ± 0,24) e carcinomas sólidos (1,95 ± 0,30) mostraram diferença significativa quando comparados ao grupo controle (1,16 ± 0,08). A análise morfológica das AgNORs mostrou que o padrão de apresentação da NORs do tipo I prevaleceu nos grupos neoplásicos benignos (75% dos casos de adenoma tubular e 50% dos casos de carcinoma tubular), enquanto o tipo II prevaleceu nos grupos neoplásicos de comportamento maligno (54,5 % dos carcinomas papilíferos e 100% dos carcinomas sólidos). O grupo controle mostrou na sua totalidade (100% dos casos) predominância de NORs do tipo IV. O padrão do Tipo III não predominou em nenhum dos grupos envolvidos neste estudo. A análise da morfologia das AgNORs é uma ferramenta útil na determinação do prognóstica de alterações neoplásicas da glândula mamária canina.

The aim of this study was try to present a new method of evaluation of the nucleolar organizer regions (NORs) being related its morphology and distribution, objectifying to verify the correlation between malignancy of tumoral cells with cellular proliferation. Twenty-nine tumors were analyzed with regard to quantitative and morphological aspects of the silver staining nucleolar organizer regions (AgNORs) and compared to four normal mammary glands used as control. The data obtained were submitted to non-parametric Kruskal- Wallis and Mann-Whitney ôUõ tests. The mean NORs counts of the malignant neoplastic groups tubular carcinomas (2.14 ± 0.54), papillary carcinomas (1.79 ± 0.24) and solid carcinomas (1.95 ± 0.30) showed significant difference when compared with the control group (1.16 ± 0.08). Morphological analysis of AgNORs revealed that the expression pattern of type I NORs predominate in the benign histological groups (75% of the tubular adenoma cases and 50% of the tubular carcinoma cases), whereas type II NORs pattern prevailed in the malignant behavior neoplastic groups (54,5% of the papillary carcinoma and 100% of the solid carcinoma cases). Control group showed total predominance (100% of the cases) of type IV NORs. Expression pattern of the type III NORs did not prevail in neither histological group encompassed by this study. Evaluation of AgNORs morphology reveals an useful tool for prognosis assessment of neoplastic alterations of the canine mammary gland.

Astylus variegatus (Coleoptera, Melyridae): Cytogenetic study of a population exposed to agrochemical products

In this work we describe the cytogenetic analyses performed in specimens of Astylus variegatus (Germar, 1824) collected in two localities: one area of natural vegetation and one of agricultural crops, where agrochemical products were used. Astylus variegatus had karyotypes with 2n(male) = 16+Xy p and 2n (female) = 16+XXp, with exclusively metacentric chromosomes. Pachytene spermatocytes showed synapsed autosomal bivalents and non-associated sex chromosomes. In diplotene, the autosomal bivalents exhibited one or two terminal chiasmata and the Xy p had a typical parachute configuration. In meiotic cells of some specimens, an extra chromosome, interpreted as a B chromosome, was observed. C-banding showed constitutive heterochromatin in the pericentromeric region of all chromosomes, with the exception of the y p. Silver nitrate staining revealed one nucleolus organizer region (NOR) on the terminal region of the short arm of the second autosome pair. Silver staining of meiotic cells confirmed the NOR pattern detected in mitotic cells and revealed an argentophilous material on the Xy p. A cytogenetic comparison between the two populations of A. variegatus showed a statistically significant divergence (chi2 = 117.10; df = 1) in the number of aneuploid cells and a higher frequency of B chromosome in the population exposed to agrochemicals.