D. Cavallo

Sex Identification in the Egyptian Vulture by Flow Cytometry and Cytogenetics

The genome size and sex of the Egyptian Vulture (Neophron percnopterus), a sexually monomorphic bird, were identified from blood samples by the use of flow cytometry (FCM). This technique allowed evaluation of the slightly higher amount of DNA content in the homogametic male compared to that of the heterogametic female. A karyotypic analysis also was performed in order to confirm the FCM results. Sex identification by both FCM and cytogenetic analyses was concordant in all cases. The average DNA content was estimated to be 5.6% higher in males than in females.

Karyological and flow cytometric evidence of triploid specimens in Bufo viridis (Amphibia Anura)

Karyological and flow cytometric (FCM) analyses were performed on a group of 14 green toads of the Bufo viridis species from seven Eurasian populations. Both approaches gave concordant results concerning the DNA ploidy level. All the populations examined were represented exclusively by diploid or tetraploid specimens, except one, where triploids were found. Results evidenced an interpopulation variability in DNA content against the same ploidy level, as well as an unusually high number of triploids in a particular reproductive place. The origin of polyploidy and the presence and persistence of a high number of triploids in a particular population are discussed.

Flow cytometric and cytogenetic analyses in human spontaneous abortions

Cytogenetic and flow cytometric analyses were performed on 38 human spontaneous abortions in an attempt to obtain information on karyotype abnormalities and to compare the two approaches of analysis. In 19 cases, it was not possible to perform cytogenetic analysis because too long a time had passed between surgical sampling and cell culture, and in vitro culture failed. Of the 19 cases analyzed, 10/19 showed a normal karyotype and 5/19 showed a single trisomy (2/5 trisomies involved chromosome 16, 1/5 trisomy involved chromosome 18, 1/5 trisomy involved chromosome 20, and 1/5 was Klinefelter syndrome). Of the remaining 4/19 cases, 2/19 showed a polyploid condition (1 tetraploidy and 1 triploidy), 1/19 a double trisomy (chromosomes 13 and 21), and 1/19 a pentasomy of the sex chromosomes (49,XXXXY). Flow cytometric analysis was performed on all abortive samples. The samples were subdivided, when possible, into two portions conventionally named “amniotic” and “chorionic”, using the amniotic membrane as an anatomical reference. Maternal blood lymphocytes were used as a diploid standard for each sample. In the 19 cases not analyzed by the cytogenetic approach, flow cytometric analysis showed 9 diploid and 10 aneuploid DNA distributions. In the remaining 19 cases, analyzed with both approaches, the comparison of DNA estimations using cytogenetic and flow cytometric analyses showed good agreement. In the cases with karyotype abnormalities, flow cytometric measurement provided evidence of an alteration of DNA content with respect to the diploid standard. Flow cytometric analysis showed a diploid distribution, whereas cytogenetic analysis revealed chromosomal abnormalities in only 4/19 cases. These discordant results could be related to mosaic conditions or maternal cell contamination. Moreover, cytogenetic and flow cytometric analyses were performed on 2 amniotic cell cultures, and concordant results were obtained. The results obtained suggest that a combination of these techniques is beneficial in attempts to obtain information about DNA content alterations, even when cultures fail, and in screening studies of human abortions.

Biological and clinical implication of cellular DNA content in renal cell carcinomas.

DNA flow cytometric analysis (FCM) was performed on surgical bioptic samples taken from 82 renal cell carcinomas. FCM has evidenced that 35% (29/82) of renal carcinomas resulted diploid, 65% (53/82) aneuploid and of the latter 22% (12/53) multiclonal. Our results do not indicate any relationship among cytometric ploidy, Fuhrman grading, Robson and pTNM staging. A possible interesting increase of aneuploidy frequency was observed between the NMV (66%) subgroup and the no zero NMV (90%) subgroup, while in diploid patients these values were 40% and 10%, respectively. Follow-up data evidence a significant difference in survival pattern of patients between diploid and aneuploid groups. In conclusion, our results show that cytometric ploidy is a potential important prognostic parameter in survival term.

Detection of cellular heterogeneity by DNA ploidy, 17 chromosome, and p53 gene in primary carcinoma and metastasis in a case of ovarian cancer

An unusual case of a patient with ovarian carcinoma carrying the p53 point mutation in both metastases (omentum and lymph node), but not in the primary tumor, is described. The presence of a p53 single mutation (G:A) at the second base of codon 248 was examined by polymerase chain reaction-amplification refractory mutation system (PCR-ARMS) analysis. This case was examined also by fluorescent in situ hybrization (FISH) analysis and flow cytometry (FCM) to obtain further information at the single cell level and to detect heterogeneity within a population of cells. FCM analysis evidenced the same multiple aneuploid cell subpopulations in primary and in metastatic samples showing the presence of a cellular heterogeneity. FISH analysis showed a disomic condition for the 17 chromosome in the primary and in one metastasis, while in the other metastasis a monosomic together with a disomic subpopulation was revealed. Our results confirm the independent clonal evolution of the metastasis. The late mutation event observed only in metastatic specimens suggests the hypothesis that in the primary tumor the wild-type gene either does not perform its control role for unknown genetic structural events or the p53 gene in this case does not play a critical role in carcinogenesis.

Cellular effects of image diagnostic ultrasound on murine spermatogenesis monitored by flow cytometry.

A study has been carried out to evaluate the possible cellular effects induced by image diagnostic ultrasound on murine spermatogenetic cells. Exposure to ultrasound was carried out using a commercial diagnostic instrument that operates in B-mode. Male hybrid F1 mice, aged 8-10 weeks, were exposed to ultrasound for 30 min and observed from 7 to 35 days after treatment. Flow cytometric analysis has been used to monitor the relative frequency of the different types of spermatogenetic cells. This analytical approach showed changes in cell frequency in the compartment containing elongated spermatids which was used as an endpoint. A statistically significant decrease in the frequency of this cell type was observed 21, 28 and 35 days after exposure. These changes suggest that there may be a cytotoxic and/or cytostatic effect on spermatocytes and spermatogonia. These results showed that image diagnostic ultrasound induces effects on murine spermatogenesis at cellular level and that the flow cytometric approach makes it possible to identify quantitative cellular changes with reference to specific cell type.

Cellular effects of diagnostic Doppler ultrasound on murine spermatogenic cells monitored by flow cytometry.

A study has been carried out to investigate the possible effects caused by Doppler diagnostic ultrasound on murine spermatogenesis. The frequency of the different types of cells has been analyzed using flow cytometry. Exposure to ultrasound was carried out using a commercial device used in diagnostic conditions. Male hybrid mice were exposed to ultrasound for 30 min and observed from 7 to 35 days after treatment. Flow cytometrical analysis showed changes in the relative frequency of the elongated spermatids and this was used as an end-point. A statistically significant decrease in the frequency of this cell type was observed after 7 and 35 days with both pulsed and continuous ultrasound. With the former, a decrease was also seen in this compartment after 14 and 21 days. Our results have shown that diagnostic ultrasound used in the Doppler technique induces effects on specific cell types of murine spermatogenesis.

The prognostic value of DNA content in patients with prostatic carcinoma.

In 80 patients with pathologically proven prostatic cancer, DNA content was correlated to grade, stage and survival. The survival curve and duration of response to therapy in these patients was examined. At the end of follow-up the cumulative survival curve in the aneuploid patients was 0.40, according to the Kaplan-Meier method, while in the diploid population it was 0.65. Differences between the two groups, aneuploid and diploid, were observed within the various histological subgroups: survival in the G2 population was 0.57 for the diploid and 0.30 for the aneuploid whereas in the G3 patients it was respectively 0.69 for the diploid and 0.05 for the aneuploid patients.