Search

There is relatively little information about the karyotype structure of the chinchilla (Chinchilla lanigera Mol.), an endemic South American rodent with 2n = 64 chromosomes and “duplicate-type X ch...

WOS: 000352489600021 In this study, Ag-nucleolar organizing region (NOR) banding patterns of Myotis myotis and Miniopterus schreibersii were presented. The karyotype of Myotis myotis has a diploid number (2n) of 44, a fundamental number (NF) of 54, and an autosomal fundamental number (NFa) of 50. The 2n, NF, and NFa numbers of Miniopterus schreibersii were 46, 54, and 56, respectively. In Myotis myotis, a homomorphic NOR was localized in 1 of the medium-sized acrocentric pairs; however, NORs were located in 2 pairs on the secondary constriction of Miniopterus schreibersii.

Standardized karyotype and idiogram of the three-spot gourami (Trichogaster trichopterus) from local market in Roi-Et province, northeast Thailand, were studied. Kidney cell samples were taken from ten male and ten female fishes. The mitotic chromosome preparations were prepared by blood cell culture as well as directly from kidney cells. Conventional and Ag-NOR staining techniques were applied to stain the chromosomes. The results showed that diploid chromosome number of T. trichopterus was 2n = 46, the fundamental numbers (NF) were 46 in both male and female. The types of autosomes were 12 large telocentric, 32 medium telocentric and 2 small telocentric chromosomes. The region adjacent to the telomere of chromosome pair 2 showed clearly observable secondary constriction / NORs. The karyotype formula for T. trichopterus could be deduced as: \( {2}n\left( {\hbox{diploid}} \right){46} = {\hbox{L}}_{{12}}^{\rm{t}} + {\hbox{M}}_{{32}}^{\rm{t}} + {\hbox{S}}_2^{\rm{t}} \).

Silver staining techniques developed to demonstrate argyrophilic nucleolar organizer regions (Ag-NORs) have been widely applied in a variety of cell kinetic studies, using the mean number of AgNORs in tumour cells as a marker for malignancy of certain types of neoplasms. However, the AgNOR techniques currently available are not entirely satisfactory, as unspecific silver precipitates readily form in the sections. On the other hand, the contrast staining, may be so weak as to render identification of the AgNORs difficult. In the present study, some of the key factors influencing the outcome of AgNOR staining were evaluated in a more systematic way. A modified AgNOR staining procedure is now proposed, giving highly contrasting AgNORs with minimal unspecific silver precipitation, thus facilitating both manual and computerized counting. The new technique involves the use of microwave irradiation in order to shorten the processing time, the use of gelatin as a protective colloid, and a Farmer's solution to optimize the specificity of the technique.

Silver staining of nucleolus organizing regions (Ag-NORs) of acrocentric chromosomes and the frequency of satellite association (SA) in bone marrow (BM) cells from 7 patients with mycosis fungoides (MF), were studied. BM samples of 7 normal healthy individuals were taken as controls. The mean number of Ag-NORs per metaphase was increased in patients (7.20 +/- 0.25) compared with controls (5.40 +/- 0.16) (p < 0.002), related with the increase of the D group. Moreover, a significant higher percentage of Ag-NOR positive cells in patients (71.7 +/- 3.9) than controls (48.0 +/- 7.8) (p < 0.02), was seen. The analysis of SA revealed a significant increase in the percentage of cells with 1-2 association pairs (ASPs) in patients with respect to their controls (p < 0.05), and a trend to a decrease in the percentage of cells without ASPs. Furthermore, a correlation between the number of Ag-NORs and the mean of ASPs per cell was also found for patients (rk = 0.65; p < 0.05). These results may be associated with a certain degree of immaturity, a high proliferative activity and modifications of the growth rate of BM cells in MF patients., Facultad de Ciencias Exactas

The nucleolar organizer regions (NORs) activity and the frequency of satellite associations (SA) in peripheral blood lymphocytes from patients with two chronic lymphoproliferative disorders were studied: 10 cases with B-cell chronic lymphocytic leukemia (B-CLL) and 10 with mycosis fungoides (MF). Thirteen healthy individuals formed the MF control group, and the oldest 7 constituted the B-CLL control group. The mean of Ag-NORs per metaphase was increased in B-CLL patients (8.80 +/- 0.63) compared with their controls (7.99 +/- 0.90) (P less than 0.025), meanwhile MF patients' value did not differ from their controls. In both disorders, the frequency of Ag-NORs in the G chromosomes was increased. The analysis of SA in B-CLL patients only revealed an increase in the frequency of cells with more than 4 ASPs (association pairs). Meanwhile, a significant higher mean of ASPs per cell in MF patients (1.74 +/- 0.41) compared to controls (1.40 +/- 0.24) (P less than 0.05) was observed. Furthermore, a close correlation between cells with complexes of 3 or more chromosomes and the mean of ASPs per cell was also found in MF. In conclusion, an increase of the Ag-NORs expression in B-CLL patients and a modification in the degree of SA in MF patients were found.

SUMMARYChromosome banding and NOR staining were performed in some representative species of Helleborus. Only H. foetidus and H. bocconei have shown specific banding patterns, while differences in number and size of nucleolus organizer regions, nucleoli and satellites have been observed within this genus. The evolutionary trends of karyotypic/nucleotypic features are briefly discussed.

One hundred and six melanocytic lesions were studied to determine the value of the so called Ag NOR technique in differentiating dysplastic naevi, Spitz naevi and spindle cell naevi of Reed from malignant melanoma and from 'banal' compound or intradermal naevi. In 79 cases Ag NOR counts were possible. The banal naevi (36) had a mean count of 1.54, (SD 0.3), and the unequivocally malignant superficial spreading melanomas (13), lentigo maligna melanomas (4) and secondary melanomas (4) had a mean count overall of 3.9 (SD 1.59). For dysplastic naevi (16) the mean Ag NOR count was 1.63 (SD 0.36) and for Spitz and spindle cell naevi (in toto 6) the figure was 1.72 (SD 0.55). The difference in Ag NOR counts between all types of naevi and all types of melanoma was highly statistically significant, but there was no difference between banal naevi and dysplastic, Spitz, and spindle cell naevi. Correlation of Ag NOR counts between three independent observers was good. This technique may, therefore, be a useful adjunct in separating true melanoma from borderline melanocytic naevi.