Cytological Variation Research Articles

Fine needle aspiration cytology of liver : An analysis of 530 cases

This is a two year study of 530 liver aspirates that included 40 benign and292malignanttumours. Smears from hepatocellular carcinomas were cellular and showed a complex ramifying Staghorn pattern. Nodular aggregates covered by endothelium and projecting within sinusoids were characteristic. Smears of cirrhosis showed smaller fragments with loosely arranged hepatocytes. Cytological variation within single cell clusters was seen in contrast to uniform atypia within a single cell cluster in hepatocellular carcinoma. Metastatic tumours showed interspersed clusters of normal hepatocytes and cytological features specific to the primary tumour. The commonest metastatic tumour was gastrointestinal adenocarcinoma. In 16cases, it was impossible to differentiate the primary or the metastatic nature of the tumour. In 16 cases, it was difficult to pinpoint the source of the metastasis. The general diagnostic yield of FNAC was 62.6% whereas that of guided FNAC was 53.8%. We attribute the latter to small sample size and the fact that guided FNAC was reserved for inaccessible, deep seated lesions and sometimes doubtful lesions.

Cytotaxonomic study of genusHymenasplenium (Aspleniaceae) in Xishuangbanna, Southwestern China

The gametic chromosome numbers of sevenHymenasplenium (Aspleniaceae) species from Xishuangbanna, Yunnan Prov., China, were investigated. All the examined individuals ofH. obscurum, H. cheilosorum andH. latipinnum were sexual diploids with n=39 chromosomes. Intraspecific cytological variation was found inH. excisum, which has a sexual diploid (n=39) and a tetraploid (n=78). Only a triploid apogamous cytotype (n=ca.117) was found inH. laterepens. Hymenasplenium apogamum showed the most complicated intraspecific variation and included a sexual diploid (n=39), a sexual tetraploid (n=78) and an apogamous triploid (n=ca.117). This work reports for the first time the sexual diploids ofH. cheilosorum andH. apogamum, which are only apogamous elsewhere in east Asia, Himalayas and Indochina. These results may indicate that this area is one of the diversity centers ofHymenasplenium. Most of the above species have chromosome numbers based on x=39. In contrast,H. costarisorum contains a sexual diploid (n=36) and a sexual tetraploid (n=72), indicating that its basic number is x=36.

Clinical, pathologic, and molecular spectrum of tumors associated with t(11;22)(p13;q12): desmoplastic small round-cell tumor and its variants.

Intense investigation has reshaped concepts about undifferentiated tumors occurring in young people (small round-cell tumors). Tumors associated with t(11;22)(p13;q12) and descriptively designated desmoplastic small round-cell tumor (DSRCT) are a distinctive, rare, poorly understood member of this family. We reviewed 109 cases of DSRCT to further characterize this entity better. Clinical information and histology were reviewed. Immunohistochemistry and immunoblotting were performed using standard techniques. Chimeric EWS-WT1 RNA and DNA were detected by polymerase chain reaction (PCR) and genomic translocation breakpoints mapped in a subset of cases. There were 90 males and 19 females from 6 to 49 years of age (mean, 22 years). A total of 103 had tumor in the abdominal cavity, four in the thoracic region, one in the posterior cranial fossa, and one in the hand. Typical histologic and immunohistochemical features were usually evident in well-sampled tumors, but variations in cellularity, stromal components, cytology, architecture, and immunoreactivity occurred. Tumor cells were usually reactive with antibodies to keratin (67 of 78 cases, 86%), epithelial membrane antigen (50 of 54, 93%), vimentin (64 of 66, 97%), desmin (70 of 78, 90%), neuron-specific enolase (60 of 74, 81%), and the EWS-WT1 chimeric protein (25 of 27, 93%); typically nonreactive for muscle common actin (one of 58, 2%), myogenin (zero of eight, 0%), and chromogranin (one of 46, 2%); and variably reactive for MIC2 (nine of 47, 20%) and p53 (five of 17 with > 20% tumor cells reactive). Functional EWS-WT1 gene fusion was evident in 25 of 26 cases with genomic breakpoints in WT1 intron 7, and EWS introns 7, 8, and 9. Prognosis in general is poor, but tumors are responsive to aggressive therapy. This large review identifies a greater degree of clinical, pathologic, and molecular variation than originally appreciated for tumors associated with t(11;22)(p13;q12). Translocation and functional fusion of the EWS and WT1 genes appears to be a consistent feature of this unique tumor.

Chromosome numbers of Phragmites australis (Arundineae: Gramineae) in New Zealand

Somatic chromosome numbers for New Zealand provenances of Phragmites australis are reported. A wide range of cytological variation was encountered—one plant was tetraploid (2n = 4x2 = 48), two were octoploid (2n = 8x2 = 96), and two were mixoploid (2n = 48, 53, 54; and 2n = 96, c. 264). One Australian provenance was octoploid. Possible regions of origin for the New Zealand populations are suggested, and multiple introductions postulated, although it is conceivable that some octoploids could be indigenous in a cytodeme shared with Australia.

SOMACLONAL VARIATION IN CULTURED IN VITRO TOBACCO PLANTS FROM THE HYBRID NICOTIANA GOSSEY DOMIN. X N. TABACUM L.

Incompatibility between the speciesNicotiana gosseyDomin. andN. tabacumL., resulting in complete sterility of F1hybrid, was overcome using in vitro techniques. Explants of stem parenchyma were put in culture and were regularly subcultured on Murashige and Skoog basal medium, supplemented with different compounds: α-naphthaleneacetic acid (2 mg L−1) and kinetin (0.5 mg L−1) for callus induction, kinetin (2 mg L−1) and indule-3-acetic acid (0.5 mg L−1) for organ formation, and ferulic acid (2 mg L−1) for rooting. The regenerants obtained showed significant morphological and cytological variability. They differed from each other as well as from the initial material in stem length, leaf size, and flower morphology. Most of the plants examined were mixoploids. A great number of aberrations were established during the meiotic division of the regenerants. Pollen viability varied from 0 to 92%. The results of our investigations showed that the tissue culture method could be successfully applied not only for overcoming species incompatibility but also for inducing somaclonal variation and creation of a large variety of plant forms.

Genome Size Variation and Basic Chromosome Number in Pearl Millet and Fourteen Related Pennisetum Species

A systematic analysis of Pennisetum species has shown their cytological variability for basic chromosome number (x = 5, 7, 8, and 9), ploidy level, and chromosome size. We have identified the genome size and base composition of 15 species using flow cytometric procedure in order to test the relationship of these characters with the variation in basic chromosome number and to evaluate the ascendant dysploidy hypothesis from an ancestral x = 5 group. Ethidium bromide, bisbenzimlde Hoechst 33342, and chromomycln dyes have been used for genome size, percentage of AT, and percentage of GC nucleotides determination, respectively. Results show that genome sizes are variable among the Pennisetum species. This variation appears to be negatively related to the basic chromosome number. On the contrary, genome size Is not correlated with percentage of GC. This result shows that loss or gain of DNA that has occurred during evolution within this genus seems not to be especially associated with GCor AT-rich sequences.

Fine Needle Aspiration Cytology of Pleomorphic Adenoma

To assess the value of fine needle aspiration cytology (FNAC) in the diagnosis of pleomorphic adenoma and to determine the cytologic variations responsible for diagnostic errors. We retrospectively studied 212 cases cytologically diagnosed as pleomorphic adenoma. In 184 a histologic diagnosis was available. Fourteen cases of histologically proven pleomorphic adenomas with a previously erroneous cytologic diagnosis were also reviewed. This study was based on those cases with a histologic diagnosis. The sensitivity and specificity of the cytologic diagnosis of pleomorphic adenoma in our series were 92.6% and 98.4%, respectively. In relation to malignancy, the series showed six false negative and three false positive diagnoses. In those cases correctly diagnosed on aspiration (175), a typical cytologic appearance, with no diagnostic difficulties, was observed in 118 cases (67.4%); the remainder showed cytologic variations. Cellular atypia (20.6%), cystic transformation (7%) and the presence of a cylindromatous pattern (5%) resembling adenoid cystic carcinoma were the most common cytologic variations observed and responsible for the majority of the errors. The cytologic variations in FNAC of pleomorphic adenoma must be considered in order to avoid important errors in the preoperative management of and surgical approach to salivary gland lesions.

Cytological and morphological variation in hybrid swarms and introgressed population of interspecific hybrids (Oryza rufipogon Griff. × Oryza sativa L.) and its impact on evolution of intermediate types.

The morphology and cytology of selected hybrid swarms of wild and cultivated rices were studied following natural hybridization between the native species Oryza rufipogon Griff and exotic species Oryza sativa L. (var. Thaothabi and Moirangphoe). Similar studies were also conducted on populations developed through artificial hybridization of those two species. The morphological variation in plant height, anthocyanin pigmentation, Kernel and husk colour, sterility, presence of awns and grain shattering habits were similar in both natural (hybrid swarms) and artificially derived populations of interspecific hybrids. The cytological abnormalities such as quadrivalant formation at metaphase I, delayed separation, laggards and bridge formation, unequal separation and chromosomal elimination were also observed in both populations. These results indicated that the evolution of intermediate types had occurred due to genetic introgression from cultivated species to wild species. A systematic extinction of founder population was also noticed due to sudden ecological changes like deep submergence to medium submergence and human interference by growing cultivated species O. sativa L. in the area where wild species were being grown.

High Frequency Plant Regeneration fromSolarium viarumProtoplasts

ABSTRACT Cotyledons from 3 week old Solarium viarum seedlings yielded large populations of viable protoplasts. The protoplasts, isolated using a Bio–Gel® column purified enzyme mixture, exhibited a markedly enhanced plating efficiency. Embedding protoplasts in agarose beads or drops significantly promoted mitosis and colony formation. Callus proliferation was best attained in MS-based medium containing 2 mg/l α-napthalene acetic acid (NAA) plus 0.5 mg/l benzyladenine (BA). Thick, dark green shoot buds developed profusely from protoplast derived calli growing on a MS medium containing 1 mg/l zeatin. When transferred to MS lacking phytohormones (MSO), each regenerating callus produced multiple leafy shoots. Individual shoots could be excised and rooted on MSO medium. Complete plants were acclimatized in the greenhouse and later established in the open garden. Some morphological and cytological variations were recorded in the protoplast regenerants.

Flavonoid variation in eurasian Sedum and Sempervivum

Flavonoids from vegetative parts of 29 species of Eurasian Sedum, Sedum meyeri-johannis from central East Africa, 34 species of Sempervivum, and Jovibarba heuffelii have been identified after acid hydrolysis. Ten flavonoid aglycones were detected, i.e. kaempferol, herbacetin, sexangularetin, quercetin, gossypetin, corniculatusin, isorhamnetin, limocitrin, myricetin, and possibly hibiscetin. Quantitative flavonoid data were obtained by gas chromatography after trimethylsilylation and were studied with multivariate data analysis methods. Principal components analysis of the whole data set distinguishes Sedum and Sempervivum as separate groups. Flavonoid variation in Sempervivum is minimal (kaempferol is the principal flavonol of all species), which reflects the morphological uniformity of the genus and similarity in ecological preference of the species. By contrast, Eurasian Sedum contains a much wider range of flavonols and shows a high degree of parallel evolution (notably 8-hydroxylation and 8- O-methylation), which seems to mirror the enormous morphological and cytological variation present in this taxon. The recognition of groups in Sedum by principal components analysis of flavonoid data partially supports the infrageneric classification based on biosystematic data.

Phylogenetic Relationships of Dennstaedtioid Ferns: Evidence from rbcL Sequences

The ferns are an ancient group of vascular plants that have yielded a staggering array of systematic problems. Among fern classifications, the number of genera in some families has ranged over 10-fold, and some genera have been treated in up to five different families. Three main groups of leptosporangiate ferns have been recognized: the adiantoid, polypodioid, and dennstaedtioid lines. To clarify relationships among genera and families of dennstaedtioid ferns, we sequenced 1320 bp of the chloroplast gene rbcL from 45 species representing 13 families. Sequence divergence for rbcL averaged 0.9% among species within genera, 10.3% among genera within families, and 14.8% among families, suggesting that the data are appropriate for phylogenetic analysis at the generic and familial levels in ferns. Maximum parsimony analysis resulted in four shortest trees of equal length. The strict consensus tree supported many aspects of previously published hypotheses of relationship based on morphological and cytological variations. For example, the tree ferns (which form a single clade) and Hymenophyllaceae appear as sister groups to the dennstaedtioid ferns on all shortest trees. However, Polypodiaceae and adiantoid ferns, groups traditionally considered separate from the dennstaedtioid families, emerged within the dennstaedtioid clade. This analysis also suggests relationships of some problematical genera, such as Monachosorum, Calochlaena, and Lonchitis. Examination of additional DNA sequences of nuclear genes and developmental studies are needed to evaluate further the relationships suggested by phylogenetic analysis of rbcL sequence data.

Mesothelioma-like tumors of the pleura: a review of 72 autopsy cases.

The 72 mesothelioma-like tumors of the pleura (MLTP) found among 33 500 autopsy cases collected over more than 30 years are reviewed. MLTP have a worse prognosis than the 106 cases of pleural mesothelioma autopsied in our institutes with regard to survival time and metastatic spread. In MLTP, adenocarcinomas predominate with a wide range of histological and cytological variation and prominent development of connective tissue having its origin in the periphery of the lung. These intrapulmonary primary tumors often fulfill the criteria of pulmonary scar cancer. Etiologically, there is no correlation between the origin of this tumor and smoking or exposure to asbestos. The absence of mucus formation and glandular differentiation, together with the presence of spindle-shaped carcinoma components and strong mesothelial or stroma proliferation, can make the differential diagnosis between this tumor type and mesothelioma difficult. Immunohistological investigations were performed on 11 cases with antibodies against intermediate filament proteins, vascular endothelium, collagen IV, macrophage antigens, carcinoembryonic antigen (CEA), LeuM1, and the antibody BerEP4. Our investigation shows that a battery of several tumor markers, such as antibodies against LeuM1, CEA, and the antibody BerEP4, as well as staining with periodic acid/Schiff/diastase discriminate primary from secondary pleural neoplasms, whilst intermediate filament proteins alone are of little diagnostic value.

Cytological characterization of isolated sperm cells of perennial ryegrass (Lolium perenne L.)

The cytoplasmic content and the distribution of intramembrane particles (IMPs) of the plasma membrane of isolated sperm cells of perennial ryegrass (Lolium perenne L.) have been characterized using flow cytometry, transmission electron microscopy, confocal scanning laser microscopy and freeze-fracture studies. The isolated haploid sperm cells contain a variety of cell organelles with the exception of microtubules. Proplastids and plastids with starch were observed, although only rarely. Vacuoles containing remnants of organelles and stacked lamellae of endoplasmic reticulum with cytoplasmic inclusions were observed frequently, indicating that autophagy takes place. The number of mitochondria varies from 11 to 26 with an average of 17. Generally, the nucleus has a lobed shape and displays various interphasic stages of chromatin condensation. The analysis of the number of mitochondria and the nuclear state did not show evidence of sperm cell dimorphism. The cytological variability observed, could be explained by differences in developmental stages already present in vivo at the moment of isolation. No correlation between the number of mitochondria and the nuclear cross-sectioned area and/or the condensation state of the chromatin could be found. The density of intramembrane particles of the plasma membrane on the exoplasmic fracture face is more than twice that on the protoplasmic fracture face. That is the opposite of what was found for sporophytic cells of perennial ryegrass. These results are discussed in relation to the potential use of these cells for biotechnology and developmental studies.

Effect of genotype on chromosome variation in tissue culture of inbred and outbred rye

To examine the effect of genotype on the nature of the cytological variation induced in culture, plants were regenerated from cultured immature embryos of six genotypes (lines A-F) of rye (Secale cereale L.). The variation observed differed among the six lines and was generally consistent with the donors. Regenerants of line A were consistent with the donor, cv. Ailes, in that chromosome translocations appeared at high frequencies. No structural or numerical variation was observed in the B chromosomes of line B. Two of the four inbred lines studied were very stable in culture. Inbred line D was also stable except for a translocation in the regenerants. In inbred line F, variation was observed in the donors and the regenerants. An examination of chiasma frequency and distribution indicated that the regenerated plants generally had higher chiasma frequencies and more distally localized chiasmata than the donors. Line F was exceptional in that the regenerants had more interstitial chiasmata. The elevation in chiasma frequency was not as great, or statistically as significant, as the change in distribution. These results provide further evidence that the nature of cytological variation observed in regenerated plants is genotype-dependent and that, in addition to numerical and structural chromosome variation, shifts in chiasma frequency and distribution, and therefore in genetic recombination, can occur as a result of somaclonal variation.

Somaclonal Variation in Wheat

ABSTRACTPlants were regenerated in a large scale from callus cultures initiated from immature embryos of hexaploid and tetraploid wheat (Triticum aestivum l. and T. durum). Significant variation in cytology, morphology and the phenotype was observed in R1 plants. Fourth (SC4) and fifth (SC5) seed generation of callus derived plants were evaluated for variation in agronomic and morphological characters such as plant height, spike length, number of tillers, etc. Among the unfavourable changes, a desirable variation, such as an increased protein content in the grain was found.

Analysis of genetic stability of plants regenerated from suspension cultures and protoplasts of meadow fescue (Festuca pratensis Huds.)

A cytological and molecular analysis was performed to assess the genetic uniformity and true-to-type character of plants regenerated from 20 week-old embryogenic suspension cultures of meadow fescue (Festuca pratensis Huds.), and compared to protoplastderived plants obtained from the same cell suspension. Cytological variation was not observed in a representative sample of plants regenerated directly from the embryogenic suspensions and from protoplasts isolated therefrom. Similarly, no restriction fragment length polymorphisms (RFLPs) were detected in the mitochondrial, plastid and nuclear genomes in the plants analyzed. Randomly amplified polymorphic DNA markers (RAPDs) have been used to characterise molecularly a set of mature meadow fescue plants regenerated from these in vitro cultures. RAPD markers using 18 different short oligonucleotide primers of arbitrary nucleotide sequence in combination with polymerase chain reaction (PCR) allowed the detection of pre-existing polymorphisms in the donor genotypes, but failed to reveal newly generated variation in the protoplast-derived plants compared to their equivalent suspensionculture regenerated materials.The genetic stability of meadow fescue plants regenerated from suspension cultures and protoplasts isolated therefrom and its implications on gene transfer technology for this species are discussed.

Cytogenetic variation in rye regenerated plants and their progeny

Regenerated plants obtained from immature embryo-derived calluses of four cultivars of rye, as well as their progeny, were cytologically analyzed. Chromosome number modified plants were found among the regenerants. The progeny of apparently normal diploid regenerated plants was tested and in some cases chromosomally abnormal plants appeared. Equally, meiotic abnormalities were observed in some of the regenerated plants and their progenies. The cytological variations observed were inheritable and in some cases both types of abnormalities could be related. The nature of the variations is discussed.Key words: Secale cereale, somaclonal variation, nondiploid plants, meiotic abnormalities.

Plant regeneration and chromosome instability in tissue culture of Elymus canadensis × E. trachycaulus F1 hybrid

Callus was induced from pieces of immature inflorescence of a sterile F1 hybrid (2n = 4x = 28) between Elymus canadensis and E. trachycaulus on MS medium supplemented with 2 mg/L of 2,4-D. Calli were of two types: compact or soft. Regeneration occurred predominantly from the compact callus. Although some plantlets were obtained on the callus initiation medium, the frequency of regeneration increased considerably when the callus was transferred to an auxin-free MS medium. Deliberate aging of callus induced cytological instability and variation in chromosome number of the regenerants. Five of the 43 regenerated plants had deviant chromosome numbers, including an octoploid (2n = 8x = 56). Chromosome pairing in the octoploid plant suggests that it originated through chromosome doubling.Key words: callus culture, variation, chromosome number.

Bellini Duct Carcinoma of the Kidney

Human epithelial cells of the kidney present a wide spectrum of cytological and histological variation. The normal epithelium of the kidneys also includes a number of morphologically and functionally different cell types which are arranged along the nephrons and collecting ducts. Although renal carcinoma can involve any type of renal cell, the most common is renal cell carcinoma of the proximal tubuli. Here, we present the case of a 65-year-old Japanese patient with a renal cell carcinoma arising from Bellini duct epithelial cells. State-of-the-art techniques were used to establish the diagnosis and histogenesis of this renal cell carcinoma.

Cytological studies inCyclamen subg.Cyclamen (Primulaceae)

Although theCyclamen subg.Cyclamen spp. are morphologically variable, previous studies suggest a superficial cytological uniformity. New chromosome numbers and an indication of karyotypic instability are reported inC. hederifolium andC. africanum that reveal that the cytology of the subgenus is more complicated than previous accounts suggest. The possible significance of these phenomena is discussed. The diploid status ofC. purpurascens has been confirmed and a distinction between the three diploid karyotypes has been described. The cytological variation may help to explain the well documented morphological variation exhibited in these species.