Analysis of nuclear DNA content and ploidy in higher plants

This is the first of a series of units discussing the application of cytometry to plant material. Techniques commonly used for mammalian nuclei evaluation need considerable modification to be successful with plant material. David Galbraith and his colleagues bring together many years of knowledge in plant cytometry. Their unit provides detailed protocols on measuring DNA content, ploidy, and cell cycle status of plant tissue using both conventional laser based instruments as well as arc lamp cytometers. This unit provides an excellent starting point for those interested in doing cytometry with plants.

Flow analysis and sorting of plant chromosomes

The use of flow cytometry for evaluation of plant chromosomes requires some specialized attention to preparation and instrumentation. This unit deals exclusively with plant cytogenetics and presents an outline of this area as well as methods for accumulation of cells in metaphase, preparation of chromosome suspensions, flow analysis and sorting of chromosomes, and processing of the sorted chromosomes. Each method is described in tremendous detail because in many aspects dealing with plant cells is quite different from dealing with mammalian cells. Supporting histograms are presented as well as a range of special hints on dealing with plant material and a discussion of the utility of sorted chromosomes for plant genome mapping.

Cytogenetics of Festulolium (Festuca x Lolium hybrids)

Grasses are the most important and widely cultivated crops. Among them, ryegrasses (Lolium spp.) and fescues (Festuca spp.) provide high quality fodder for livestock, are used for turf and amenity purposes, and play a fundamental role in environment protection. Species from the two genera display complementary agronomic characteristics and are often grown in mixtures. Breeding efforts to combine desired features in single entities culminated with the production of Festuca x Lolium hybrids. The so called Festuloliums enjoy a considerable commercial success with numerous cultivars registered all over the world. They are also very intriguing from a strictly cytogenetic point of view as the parental chromosomes recombine freely in hybrids. Until a decade ago this phenomenon was only known in general quantitative terms. The introduction of molecular cytogenetic tools such as FISH and GISH permitted detailed studies of intergeneric chromosome recombination and karyotyping of Festulolium cultivars. These tools were also invaluable in revealing the origin of polyploid fescues, and facilitated the development of chromosome substitution and introgression lines and physical mapping of traits of interest. Further progress in this area will require the development of a larger set of cytogenetic markers and high-resolution cytogenetic maps. It is expected that the Lolium-Festuca complex will continue providing opportunities for breeding superior grass cultivars and the complex will remain an attractive platform for fundamental research of the early steps of hybrid speciation and interaction of parental genomes, as well as the processes of chromosome pairing, elimination and recombination.

[Robot-assisted pulmonary lobectomy--our first experiences]

The authors present their first experience and the results of robot-assisted pulmonary lobectomies. The paper reports on the placement of the working channels, auxiliary minithoracotomies, the patient's position, the positions of the four-arm body of the da Vinci robotic system, and particularly the technique of lobectomy. In our institution, 5 robot-assisted lobectomies were performed in two women and three men (aged 45, 52, and 57, 67, 54 years, respectively). The lower lobectomy was performed four times left and once right. The surgery was always supplemented with mediastinal lymphadenectomy. The vessels were ligated mechanically with the use of the robot. No serious complications were observed during the surgery or in the postoperative period. Robot-assisted lobectomy is a safe method of pulmonary resection in the early stages of bronchogenic carcinoma (Ia, Ib); it ensures a faster convalescence of the patient compared with open surgery.

[Robotic procedures in the colorectal surgery]

PURPOSE

The da Vinci surgical system (Intuitive Surgical, Sunnyvale, CA, USA) was developed specifically to compensate the technical limitations of laparoscopic instruments, such as two-dimensional vision, misalignment of hands and instruments, limited dexterity of instruments inside the patient, and fixed instrument tips. The da Vinci system provides a stable camera platform, three-dimensional imaging, excellent ergonomics, tremor elimination, ambidextrous capability, motion scaling, and instruments with multiple degrees of freedom.

METHODS

These advantages can be applied in the field of colorectal surgery, and that's why we are reporting 45 cases that underwent robotic colorectal surgery. We concluded that the da Vinci system may be useful in surgical procedures, such as splenic flexure takedown, dissection of the inferior mesenteric artery with identification of the nervous plexus, and dissection of a narrow pelvis. The major drawbacks of robotic systems are high cost, and a lack of tactile sensation and tensile feedback to the surgeon, who must depend on visual cues to estimate the tension exerted on tissue by the robotic arms.

RESULTS

In conclusion, robotic colorectal surgery can be performed safely and effectively, using the da Vinci surgical system, because this system has more dexterity and flexibility than conventional laparoscopic instruments. However, prospective randomized studies are necessary to evaluate the preservation of sexual and voiding function, as well as the oncological and functional (pelvic floor disorders) outcomes of this approach.

Condensation of rye chromatin in somatic interphase nuclei of Ph1 and ph1b wheat

The Ph1 locus in hexaploid wheat (Triticum aestivum L.) enforces diploid-like behavior in the first metaphase of meiosis. To test the hypothesis that this chromosome pairing control is exercised by affecting the degree of chromatin condensation, the dispersion of rye chromatin in interphase nuclei in somatic tissues of wheat-rye chromosome translocations 1RS.1BL, 2RS.2BL, 2BS.2RL, 3RS.3DL and 5RS.5BL was compared in Ph1 and ph1b isogenic backgrounds. No significant differences in rye chromatin condensation that could be attributed to the Ph1 locus were detected. Regardless of the Ph1 status, each rye chromosome arm tested conformed to the general Rabl's orientation and occupied portions of the nuclei proportional to their length. Earlier observations that indicated the involvement of Ph1 locus in rye chromatin condensation in wheat could have been due either to specific loci on the studied 5RL rye arm that control the chromosome condensation process or to damage to the genetic system controlling chromatin condensation in the existing ph1b stocks of wheat. That damage might have been caused by homoeologous recombination and uneven disjunction of chromosomes from multivalents.

Isolation and characterization of the highly repeated fraction of the banana genome

Although the nuclear genome of banana (Musa spp.) is relatively small (1C approximately 610 Mbp for M. acuminata), the results obtained from other sequenced genomes suggest that more than half of the banana genome may be composed of repetitive and non-coding DNA sequences. Knowledge of repetitive DNA can facilitate mapping of important traits, phylogenetic studies, BAC-based physical mapping, and genome sequencing/annotation. However, only a few repetitive DNA sequences have been characterized in banana. In this work, we used DNA reassociation kinetics to isolate the highly repeated fraction of the banana genome (M. acuminata 'Calcutta 4'). Two libraries, one prepared from Cot </=0.05 DNA (2,688 clones) and one from Cot </=0.1 sequences (4,608 clones), were constructed, and 614 DNA clones were chosen randomly for sequencing and further characterization. Dot-plot analysis revealed that 14% of the sequenced clones contained various semi-tandem and palindromic repeated sequences. 'BLAST' homology searches showed that, in addition to tandem repeats, the Cot libraries were composed mainly of different types of retrotransposons, the most frequent being the Ty3/gypsy type monkey retrotransposon. Selected sequences displaying tandem organization properties were mapped by PRimed IN Situ DNA labeling (PRINS) to the secondary constriction on metaphase chromosomes of M. acuminata 'Calcutta 4'. Southern hybridization with selected BAC clones carrying 45S rDNA confirmed the presence of the tandem repeats in the 45S rDNA unit. This work significantly expands the knowledge of the repetitive fraction of the Musa genome and organization of its chromosomes.

Robot-assisted pulmonary lobectomy

The authors present their first experience and the results of robot-assisted pulmonary lobectomies. The paper reports on the placement of the working channels, auxiliary minithoracotomies, the patient's position, the positions of the four-arm body of the da Vinci robotic system, and particularly the technique of lobectomy. In our institution, 4 robot-assisted lobectomies were performed in two women and two men (aged 45, 52, and 57, 67 years, respectively). The vessels were ligated mechanically with the use of the robot. An auxiliary minithoracotomy of a length of 5 cm was performed in the fifth intercostal area posterolaterally. The lower lobectomy was performed three times left and once right. The surgery was always supplemented with mediastinal lymphadenectomy. No serious complications were observed during the surgery or in the postoperative period. Robot-assisted lobectomy is a safe method of pulmonary resection in the early stages of bronchogenic carcinoma (Ia, Ib); it ensures a faster convalescence of the patient compared with open surgery (Ref. 14).

[Multiple lung metastasectomy for the poor differentiated metastatic synovial sarcoma]

OBJECTIVES

Synovial sarcoma is the rare indication for the pulmonary metastasectomy due to its aggressive biologic behavior and early dissemination. The radical surgical approach in therapy of the multiple pulmonary metastases could improve quality of life and median survival in carefully selected patients.

METHODS

From the group of 7 patients with the lung metastases of the synovial sarcoma operated in our department during the last 5 years we are presenting the case of the 39 years old man with the previous history of the surgical removal of the synovial sarcoma near the cubital fossa one year before. Considering the lungs as the only organ involved, bilateral complete metastasectomy through muscle sparing vertical thoracotomies was done. There were 12 metastases from all lung lobes with the exception of the right middle lobe. Analysis of the pathologist showed biphasic metastatic synovial sarcoma with the high mitotic activity. The 6 cycles of the MAID regime succeeded.

RESULTS

Median survival of the whole group is 25 months, there are 3 patients alive. In the above mentioned patient 1 year after the metastasectomy PET-CT showed focus of the 4th left rib suspected to be malignant. Wide resection of the rib was done, but no malignancy was disclosed, there were only reparative changes. The patient has been tolerated the oncological treatment very well and 45 months after the lung metastasectomy there are no sings of a malignant disease.

CONCLUSION

Lung metastasectomy of the multiple lung metastases of the synovial sarcoma is of value despite of uncertain long-term prognosis. It is recommended to consider the metastasectomy even in low differentiated tumors. The prerequisite for the effective treatment is a complete resection.

Genome constitution and evolution in Lolium x Festuca hybrid cultivars (Festulolium)

Festulolium hybrids are being increasingly used worldwide as forage grasses. This is due to their superior agronomic characteristics, which combine yield performance of ryegrasses (Lolium multiflorum and L. perenne) and tolerance against abiotic stress of fescues (Festuca pratensis, F. arundinacea and F. arundinacea var. glaucescens). Despite the widespread use, only fragmentary information exists on their genomic constitution. We used genomic in situ hybridization (GISH) to analyze genomic constitution of over 600 plants from almost all commercially available cultivars of Festulolium. Our results revealed a surprisingly large range of variation in the proportions of parental genomes and in the extent of intergenomic recombination. Using fluorescence in situ hybridization (FISH) with probes for ribosomal DNA, we assessed the frequency of recombination and elimination of particular chromosomes and chromosome groups in three contrasting Festulolium cultivars. This study provides novel information that will aid in understanding the relationship between a genetic make-up and the phenotype of Festulolium hybrids. Our results indicate that GISH might be a useful tool to aid in Festulolium breeding and provide data for a more detailed description of registered cultivars.

Rare incidence of pulmonary gangrene--algorithm of the treatment

The pulmonary gangrene is rare and serious disease. Our experience is based on the treatment of the 2 patients with pulmonary gangrene during the last twenty years. The first and lifesaving step in the treatment of sepsis is the early removal of the necrotic tissue. Next surgery succeeds usually after one week after initial treatment. Surgical treatment continues step by step, we do not advise providing of a major anatomical resection in the initial stage of the disease. This policy is effective in the treatment of this serious disease.

Nuclear genome size and genomic distribution of ribosomal DNA in Musa and Ensete (Musaceae): taxonomic implications

Nuclear DNA content and genomic distributions of 5S and 45S rDNA were examined in nineteen diploid accessions of the genus Musa representing its four sections Eumusa, Rhodochlamys, Callimusa and Australimusa, and in Ensete gilletii, which was the outgroup in this study. In the Eumusa (x = 11), 2C DNA content ranged from 1.130 to 1.377 pg, M. balbisiana having the lowest DNA content of all sections. M. beccarii (x = 9), a representative of Callimusa, had the highest 2C nuclear DNA content (1.561 pg). Species belonging to Rhodochlamys (x = 11) and Australimusa (x = 10) had 2C DNA contents ranging from 1.191 to 1.299 pg and from 1.435 to 1.547 pg, respectively. E. gilletii (x = 9) had 2C DNA content of 1.210 pg. The number of 5S rDNA loci in Musa varied from 4 to 8 per diploid cell. While different numbers of 5S rDNA loci were observed within Eumusa and Rhodochlamys, four 5S rDNA loci were observed in all accessions of Australimusa. M. beccarii (Callimusa) and E. gilletii contained 5S rRNA gene clusters on five and six chromosomes, respectively. The number of 45S rDNA loci was conserved within individual sections. Hierarchical cluster analysis of genome size, number of chromosomes and 45S rDNA sites suggested a close relationship between Rhodochlamys and Eumusa; Australimusa was clearly separated as were M. beccarii and E. gilletii. Within the Eumusa-Rhodochlamys group, M. balbisiana, M. schizocarpa and M. ornata formed distinct subgroups, clearly separated from the accessions of M. acuminata, M. mannii, M. laterita and M. velutina, which formed a tight subgroup. The results expand the knowledge of genome size and genomic distribution of ribosomal DNA in Musa and Ensete. They aid in clarification of the taxonomical classification of Musa and show a need to supplement the analyses on the DNA sequence level with cytogenetic studies.

Assessment of ploidy stability of the somatic embryogenesis process in Quercus suber L. using flow cytometry

Flow cytometry analyses were used to verify the ploidy stability of Quercus suber L. somatic embryogenesis process. Leaf explants of two adult cork oak trees (QsG0 and QsG5) of the North of Portugal were inoculated on MS medium with 2,4-D and zeatin. After 3 months, calluses with embryogenic structures were isolated and transferred to fresh MS medium without growth regulators and somatic embryo evolution was followed. Morphologically normal somatic embryos (with two cotyledons) and abnormal somatic embryos (with one or three cotyledons) were used in this assay. Flow cytometry combined with propidium iodide staining was employed to estimate DNA ploidy levels and nuclear DNA content of somatic embryos and leaves from mother plants. No significant differences (P< or =0.05) were detected among embryos, and between the embryos and the mother plants. Also, after conversion of these embryos, no significant morphological differences were observed among the somatic embryo-derived plants. These results and further studies using converted plantlet leaves and embryogenic callus tissue indicate that embryo cultures and converted plantlets were stable with regard to ploidy level. As no major somaclonal variation was detected our primary goal of "true-to-type" propagation of cork oak using somatic embryogenesis was assured at this level. The estimation of the 2C nuclear DNA content for this species is similar to the previously obtained value.

Peroxisome proliferator-activated receptors (PPAR) agonists affect cell viability, apoptosis and expression of cell cycle related proteins in cell lines of glial brain tumors

The nuclear receptors PPARs (peroxisome proliferator-activated receptors) are transcription factors activated by specific ligands. PPARs play an important role in carcinogenesis, inflammation, atherosclerosis, lipid metabolism and diabetes. There is evidence that activation of PPARs by specific ligands is able to suppress the growth of different types of human cancer by mechanisms including the growth arrest, apoptosis and induction of differentiation, although the detailed signalling pathways have not been completely elucidated to date. The aim of our study was to determine whether synthetic ligands of PPARalpha and PPARgamma could affect the viability, proliferation, differentiation, apoptosis and expression of some cell cycle related proteins in glial tumor cell lines. The study was performed on human glioblastoma cell lines U-87 MG, T98G, A172 and U-118 MG. Cell lines were treated by ligands of PPARalpha (bezafibrate, gemfibrozil) and PPARgamma (ciglitazone). MTT, flow cytometry, TUNEL assay and immunoblotting were used for detection of changes in cell viability, proliferation, differentiation and apoptosis. Bezafibrate, ciglitazone and gemfibrozil inhibited viability of glioblastoma cell lines. The synthetic ligands significantly reduced or induced the expression of cyclins, p27Kip1, p21Waf1/Cip1, MDM-2, Bcl-2, Bax, PARP, Caspase 3, androgen receptors, etc. and did not affect the expression of the differentiation marker GFAP. Flow cytometry confirmed arrest of the cell cycle although the detection of apoptosis was controversial. Apart from hypolipidemic and hypoglycaemic effects, PPAR ligands may also have significant cytostatic effects of potential use in anticancer treatment.

Antireflux Uretero-Intestinal Anastomosis—Flap-and-Trough Technique—Applicable to Ileum: Early Clinical Experience

OBJECTIVE

To report our functional results of the "flap-and-trough" (FT) antireflux uretero-intestinal anastomosis (UIA) applied to various forms of urinary diversions.

PATIENTS AND METHODS

From April 1998 through March 2003, a total of 49 ureters were implanted in 28 patients into various types of urinary diversions. Forty-six ureters were implanted transluminally (32 separately, 14 conjointly by the double-barrelled method), 3 ureters extraluminally into preformed reservoirs during kidney transplantation. Forty-one ureters were implanted primarily, 8 ureters secondarily due to stricture of former UIA.

RESULTS

Median observation time was 26 months. The healing was uneventful in all cases. Late complications were not related to the UIA. Twenty-four patients could be evaluated. The upper urinary tract remained stable, no reflux and no stenosis at the site of UIA were detected. FT anastomoses were clearly seen and easily accessible at endoscopy.

CONCLUSION

In our hands the FT anastomosis has proved to be simple, safe and highly effective in terms of protecting the upper urinary tract against obstruction and reflux. Creation of antireflux UIA need not mean increased risk of obstruction in comparison with direct (reflux) ones. The FT technique could represent another alternative of nonrefluxing implantation of normal as well as dilated ureters into various types of urinary diversion.

Analysis and sorting of rye (Secale cereale L.) chromosomes using flow cytometry

Procedures for chromosome analysis and sorting using flow cytometry (flow cytogenetics) were developed for rye (Secale cereale L.). Suspensions of intact chromosomes were prepared by mechanical homogenization of synchronized root tips after mild fixation with formaldehyde. Histograms of relative fluorescence intensity obtained after the analysis of DAPI-stained chromosomes (flow karyotypes) were characterized and the chromosome content of the DNA peaks was determined. Chromosome 1R could be discriminated on a flow karyotype of S. cereale 'Imperial'. The remaining rye chromosomes (2R-7R) could be discriminated and sorted from individual wheat-rye addition lines. The analysis of lines with reconstructed karyotypes demonstrated a possibility of sorting translocation chromosomes. Supernumerary B chromosomes could be sorted from an experimental rye population and from S. cereale 'Adams'. Flow-sorted chromosomes were identified by fluorescence in situ hybridization (FISH) with probes for various DNA repeats. Large numbers of chromosomes of a single type sorted onto microscopic slides facilitated detection of rarely occurring chromosome variants by FISH with specific probes. PCR with chromosome-specific primers confirmed the identity of sorted fractions and indicated suitability of sorted chromosomes for physical mapping. The possibility to sort large numbers of chromosomes opens a way for the construction of large-insert chromosome-specific DNA libraries in rye.

Development of a composite map in Vicia faba, breeding applications and future prospects

A composite map of the Vicia faba genome based on morphological markers, isozymes, RAPDs, seed protein genes and microsatellites was constructed. The map incorporates data from 11 F(2) families for a total of 654 individuals all sharing the common female parent Vf 6. The integrated map is arranged in 14 major linkage groups (five of which were located in specific chromosomes). These linkage groups include 192 loci and cover 1559 cM with an overall average marker interval of 8 cM. By joining data of a new F(2) population segregating for resistance to ascochyta, broomrape and others traits of agronomic interest, have been saturated new areas of the genome. The combination of trisomic segregation, linkage analysis among loci from different families with a recurrent parent, and the analysis of new physically located markers, has allowed the establishment of the present status of the V. faba map with a wide coverage. This map provides an efficient tool in breeding applications such as disease-resistance mapping, QTL analyses and marker-assisted selection.

High-resolution FISH on super-stretched flow-sorted plant chromosomes

A novel high-resolution fluorescence in situ hybridisation (FISH) strategy, using super-stretched flow-sorted plant chromosomes as targets, is described. The technique that allows longitudinal extension of chromosomes of more than 100 times their original metaphase size is especially attractive for plant species with large chromosomes, whose pachytene chromosomes are generally too long and heterochromatin patterns too complex for FISH analysis. The protocol involves flow cytometric sorting of metaphase chromosomes, mild proteinase-K digestion of air-dried chromosomes on microscopic slides, followed by stretching with ethanol:acetic acid (3 : 1). Stretching ratios were assessed in a number of FISH experiments with super-stretched chromosomes from barley, wheat, rye and chickpea, hybridised with 45S and 5S ribosomal DNAs and the [GAA]n microsatellite, the [TTTAGGG]n telomeric repeat and a bacterial artificial chromosome (BAC) clone as probes. FISH signals on stretched chromosomes were brighter than those on the untreated control, resulting from better accessibility of the stretched chromatin and maximum observed sensitivity of 1 kbp. Spatial resolution of neighbouring loci was improved down to 70 kbp as compared to 5-10 Mbp after FISH on mitotic chromosomes, revealing details of adjacent DNA sequences hitherto not obtained with any other method. Stretched chromosomes are advantageous over extended DNA fibres from interphase nuclei as targets for FISH studies because they still retain chromosomal integrity. Although the method is confined to species for which chromosome flow sorting has been developed, it provides a unique system for controlling stretching degree of mitotic chromosomes and high-resolution bar-code FISH.

Intraabdominal pressure after rectal resections

The mean correlation curves of the intraabdominal pressure over time were evaluated by regression analysis (value 0.05) in both groups. The curves had a rising character in both groups, but in the control group the curve rose more steeply and reached a higher level than the curve of studied group. The onset of peristalsis, first flatus and stool took a shorter time in the studied group. (Tab. 1, Fig. 5, Ref. 5.)

Videomediastinoscopy for the diagnosis of the diseases of the lung and mediastinum

BACKGROUND

The biopsy of the mediastinum by mediastinoscopy is established as the most accurate method especially in the lung cancer staging, but helps also in the diagnosis of various diseases of the lung and mediastinum. The videomediastinoscopic equipment offers more precise procedure and shorter learning curve in comparison with classical technique due to the sharing of the procedure with other (more experienced) surgeon. The aim of our work was to confirm the safety and reliability of the videomediastionoscopy in our department, where the use of the traditional technique was exceptional.

METHODS

Patients with expansion in the mediastinum (or enlargement of the mediastinal lymph nodes) of the unknown aetiology accessible by videomediastinoscopy according to CT were included. Standard videomediastinoscopic technique was used. The attempt to take biopsy of the mediastinal tumor and/or the lymph nodes in stations 1, 2, 4, 7 according the UICC regional lymph node mapping was done.

RESULTS

There were 126 patients operated by videomediastinoscopy between January 1998 and June 2003. There were 83 men with a mean age of 50.43 years (range 14 to 78 years) and 43 women with a mean age of 50.79 years (range 18 to 77 years). The diagnosis defined by explicit morphology was made in 95 cases (75.40%). In 25 cases (19.84%) the result of the biopsy was either normal lymphatic tissue or slight inflammatory changes. In three cases (2.38%) the pathologist expressed strong suspicion of the malignant disease, without clear morphology. In two cases (1.59%) all tissue samples were completely necrotic. No biopsy was done once (0.77%). There were four major groups of patients with positive histology: Patients with sarcoidosis, patients with metastases of the epithelial malignity to the mediastinal lymph nodes, patients with lymphoma and the group containing patients with a diagnosis of a low frequency (tuberculosis, sarcoma, Castleman's disease and others). No mortality was related to the procedure. We had one serious surgical complication: bleeding from the right innominate artery successfully treated by suture.

CONCLUSION

Videomediastinoscopy is a safe and accurate method with a short learning curve. The key point of the diagnostic success is a proper indication for the procedure. Videomediastinoscopic equipment and its use is to be recommend to each department of general thoracic surgery.

Development of flow cytogenetics and physical genome mapping in chickpea (Cicer arietinum L.)

Procedures for flow cytometric analysis and sorting of mitotic chromosomes (flow cytogenetics) have been developed for chickpea (Cicer arietinum). Suspensions of intact chromosomes were prepared from root tips treated to achieve a high degree of metaphase synchrony. The optimal protocol consisted of a treatment of roots with 2 mmol/L hydroxyurea for 18 h, a 4.5-h recovery in hydroxyurea-free medium, 2 h incubation with 10 micromol/L oryzalin, and ice-water treatment overnight. This procedure resulted in an average metaphase index of 47%. Synchronized root tips were fixed in 2% formaldehyde for 20 min, and chromosome suspensions prepared by mechanical homogenization of fixed root tips. More than 4 x 10(5) morphologically intact chromosomes could be isolated from 15 root tips. Flow cytometric analysis of DAPI-stained chromosomes resulted in histograms of relative fluorescence intensity (flow karyotypes) containing eight peaks, representing individual chromosomes and/or groups of chromosomes with a similar relative DNA content. Five peaks could be assigned to individual chromosomes (A, B, C, G, H). The parity of sorted chromosome fractions was high, and chromosomes B and H could be sorted with 100% purity. PCR on flow-sorted chromosome fractions with primers for sequence-tagged microsatellite site (STMS) markers permitted assignment of the genetic linkage group LG8 to the smallest chickpea chromosome H. This study extends the number of legume species for which flow cytogenetics is available, and demonstrates the potential of flow cytogenetics for genome mapping in chickpea.

Significance of a prolonged postoperative bowel paralysis in complete dehiscence of laparotomy wound

We performed 910 laparotomies in the years 1998-1999. Complete dehiscence of a laparotomy wound was observed in 18 cases. We compare the duration of postoperative bowel paralysis in patients with and without eventration. The statistical comparison of the two groups was performed with the Wilcoxon test, the level of significance was set to 5%. We have found that the duration of postoperative bowel paralysis was significantly longer in the group of patients with eventration. (Tab. 4, Ref. 5.).

Isolation, characterization and chromosome localization of repetitive DNA sequences in bananas (Musa spp.)

Partial genomic DNA libraries were constructed in Musa acuminata and M. balbisiana and screened for clones carrying repeated sequences, and sequences carrying rDNA. Isolated clones were characterized in terms of copy number, genomic distribution in M. acuminata and M. balbisiana, and sequence similarity to known DNA sequences. Ribosomal RNA genes have been the most abundant sequences recovered. FISH with probes for DNA clones Radkal and Radka7, which carry different fragments of Musa 26S rDNA, and Radka14, for which no homology with known DNA sequences has been found, resulted in clear signals at secondary constrictions. Only one clone carrying 5S rDNA, named Radka2, has been recovered. All remaining DNA clones exhibited more or less pronounced clustering at centromeric regions. The study revealed small differences in genomic distribution of repetitive DNA sequences between M. acuminata and M. balbisiana, the only exception being the 5S rDNA where the two Musa clones under study differed in the number of sites. All repetitive sequences were more abundant in M. acuminata whose genome is about 12% larger than that of M. balbisiana. While, for some sequences, the differences in copy number between the species were relatively small, for some of them, e.g. Radka5, the difference was almost thirty-fold. These observations suggest that repetitive DNA sequences contribute to the difference in genome size between both species, albeit to different extents. Isolation and characterization of new repetitive DNA sequences improves the knowledge of long-range organization of chromosomes in

Rapid detection of aneuploidy in Musa using flow cytometry

We report a procedure for the rapid and convenient detection of aneuploidy in triploid Musa using DNA flow cytometry. From a population of plants derived from gamma-irradiated shoot tips, plants were selected based on aberrant morphology and their chromosome numbers were counted. Aneuploids plants with chromosome numbers 2n=31 or 32 were found as well as the expected triploid plants (2n=3x=33). At the same time, the nuclear DNA content of all plants was measured using flow cytometry. The flow cytometric assay involved the use of nuclei isolated from chicken red blood cells (CRBC), which served as an internal reference standard. The relative DNA content of individual plants was expressed as a ratio of DNA content of CRBC and Musa (DNA index). In order to estimate the chromosome number using flow cytometry, the relative DNA content of plants with unknown ploidy was expressed as a percentage of the DNA content of triploid plants. The classification based on flow cytometry fully agreed with the results obtained by chromosome counting. The results indicated that flow cytometry is a convenient and rapid method for the detection of aneuploidy in Musa.