Intergeneric hybrids between Brassica napus and Orychophragmus violaceus containing traits of agronomic importance for oilseed rape breeding

Protoplast fusions between Brassica napus and Orychophragmus violaceus for transfer of valuable traits to oilseed rape resulted in 257 somatic hybrid plants. Hybridity was confirmed by morphological, cytological and molecular means. Symmetric fusions gave rise to 131 plants. Fifty eight of these plants had an intermediate morphology and contained nuclear DNA corresponding to the sum of the parental species. All 131 plants were sterile with no pollen grains observed upon flowering. Another 126 plants were derived from asymmetric fusions in which protoplasts of the donor parent O. violaceus were irradiated by 100 or 200-Gy X-rays prior to fusion. Morphologically these plants showed a larger variation compared to the plants regenerated from symmetric fusion experiments. In contrast to plants obtained from symmetric fusions, fertile hybrids were recovered among regenerants from the asymmetric fusions. Twenty four of these plants released viable pollen grains and 14 of the determined 17 plants set seeds after either selfing or backcrossing to B. napus. Fourteen male-sterile plants were identified with female fertility. This observed male sterility most-likely originated from alloplasmic recombination and would be of great potential for the development of a new cytoplasmic male sterility system. The fatty acid composition of the fertile hybrids and their progenies showed a biased distribution towards the B. napus parent, which has a high erucic acid-content type. However, increased levels of palmitic and linoleic acids compared to B. napus were found in subsequent generations, as well as a reduced level of erucic acid.

Reassessment of ADHD in a historical cohort of children treated with stimulants in the period 1969-1989

The operational diagnostic criteria for ADHD or HKD were not at hand in Denmark before 1994, when WHO's International Classification of Diseases -10 (ICD-10) was introduced. The criteria for ADHD/HKD were well known at our clinic, but when treating children with stimulants the criteria used clinically prior to 1994 were less specific than today. The aims of this paper are to examine the prevalence of ADHD in a historical cohort of children treated with stimulants during the period 1969-1989 and to reassess a wide range of comorbid disorders and sociodemographic characteristics in order to compare aspects of the given treatment with the modern recommendations. At our clinic 208 children (183 boys) were given stimulants during the period 1969-1989. Case records on these probands were reassessed retrospectively for DSM-IV criteria regarding ADHD and comorbid disorders as well as for characteristics of stimulant treatment. Sixty-five percent met full criteria for an ADHD diagnosis. Including Subthreshold ADHD as many as 81 % of the cohort were re-diagnosed with ADHD. Prevalence rates of conduct problems and anxiety disorder were similar to previous prospective ADHD studies. The use of stimulants during the period 1969-1989 were in accord with modern guidelines. This cohort is comparable to other clinically based ADHD cohorts as regards inattentive, hyperactive/impulsive symptoms, comorbidity, impairment, gender differences, intelligence and socio-economic status (SES).

Craniofacial morphology, dentition, and skeletal maturity in four siblings with Seckel syndrome

OBJECTIVE

To describe the craniofacial morphology, dentition, and hand maturity in four siblings with Seckel syndrome.

PATIENTS

Two boys and two girls, with Seckel syndrome. The children studied showed extreme growth retardation, severe microcephaly, bird-headed profile with receding chin, prominent nose, mental retardation, and extremely delayed skeletal maturation. The growth hormone axis and pituitary thyroid function was normal.

METHODS

Skeletal and dental development were investigated from radiographic material, and a cephalometric analysis was performed from profile radiographs.

RESULTS

The craniums were remarkably small with an extremely short anterior cranial base (-4.3 to -5.5 standard units) and maxillary length (-3.8 to -4.7 SU). Differences in the morphology of the sella turcica were observed in girls and boys. Tooth maturity progressed normally. Tooth agenesis and tooth malformations were observed. Taurodontic root morphology was observed only in the girls. The approximate skeletal maturity showed retardation from 4 years 3 months to 4 years 11 months. Malformations of the hand-wrist skeleton occurred in the epiphyseal ossification centers of the middle phalangeal bone in the second, third, and fourth finger and in the distal phalangeal bone in the fifth finger. The epiphyseal ossification centers were lacking in the middle and distal phalangeal bones of the fifth finger.

CONCLUSION

The underlying gene defect in the affected children seemingly affects bone development and growth but not dental maturation and eruption.

Graded nanostructures produced by sliding and exhibiting universal behavior

Nanostructured copper was produced by deformation under large sliding loads. In the near surface layers, 10 nm scale microstructures form and coarsen with increasing depth from the surface. The graded structure enables characterization of the structural scale over several orders of magnitude. Analysis reveals that universal scaling of the microstructure exists from 10,000 to 10 nm. The limit of scale is pushed to an order of magnitude of the ultimate scale at which the crystallinity is lost. This universality opens the door for easy manufacture of ever finer scale components by deformation.

Taxol-induced ceramide generation and apoptosis in human breast cancer cells

PURPOSE

Taxol has emerged as a valuable antimitotic chemotherapeutic agent, particularly in advanced breast and ovarian cancers. Although much is known about cytotoxic mechanisms, the effectiveness of Taxol cannot be solely explained by microtubular interaction. This study was undertaken to determine whether ceramide generation plays a role in Taxol-induced apoptosis.

METHODS

Hormone-independent MDA-MB-468 and hormone-dependent MCF-7 breast cancer cell lines were employed, and ceramide metabolism was characterized using [3H]palmitic acid as lipid precursor.

RESULTS

Exposure of cells to Taxol resulted in enhanced formation of [3H]ceramide. Ceramide increased nearly 2-fold in MDA-MB-468 cells exposed to 50 nM Taxol, and more than 2.5-fold in MCF-7 cells exposed to 1.0 microM Taxol. These concentrations mirrored the EC50 (amount of drug eliciting 50% cell kill) for Taxol in the two cell lines. Use of cell-permeable C6-ceramide as a medium supplement revealed that MDA-MB-468 cells were 20-fold more sensitive to ceramide than MCF-7 cells (P < 0.001). Ceramide was generated as early as 6 h after exposure to Taxol in MDA-MB-468 cells, whereas the earliest signs of apoptosis were detected 12 h after treatment, and by 24 h the apoptotic index was six times that of untreated cells. Both fumonisin B1, a ceramide synthase inhibitor, and L-cycloserine, a serine palmitoyltransferase inhibitor, blocked Taxol-induced ceramide generation, whilst sphingomyelin levels remained unchanged, indicating a de novo pathway of ceramide formation. L-Cycloserine reduced Taxol-induced apoptosis by 30% in MDA-MB-468 cells and totally blocked Taxol-induced apoptosis in MCF-7 cells.

CONCLUSIONS

These results suggest that Taxol-induced apoptosis is, in part, attributable to ceramide and sphingoid bases. This is of relevance to drug mechanism studies, as ceramide is a known messenger of apoptosis. Clinical use of Taxol with ceramide-enhancing agents may maximize cytotoxic potential.

Genomic evidence for a complete sexual cycle in Candida albicans

Candida albicans is a diploid fungus that has become a medically important opportunistic pathogen in immunocompromised individuals. We have sequenced the C. albicans genome to 10.4-fold coverage and performed a comparative genomic analysis between C. albicans and Saccharomyces cerevisiae with the objective of assessing whether Candida possesses a genetic repertoire that could support a complete sexual cycle. Analyzing over 500 genes important for sexual differentiation in S. cerevisiae, we find many homologues of genes that are implicated in the initiation of meiosis, chromosome recombination, and the formation of synaptonemal complexes. However, others are striking in their absence. C. albicans seems to have homologues of all of the elements of a functional pheromone response pathway involved in mating in S. cerevisiae but lacks many homologues of S. cerevisiae genes for meiosis. Other meiotic gene homologues in organisms ranging from filamentous fungi to Drosophila melanogaster and Caenorhabditis elegans were also found in the C. albicans genome, suggesting potential alternative mechanisms of genetic exchange.

Completely derandomized self-adaptation in evolution strategies

This paper puts forward two useful methods for self-adaptation of the mutation distribution - the concepts of derandomization and cumulation. Principle shortcomings of the concept of mutative strategy parameter control and two levels of derandomization are reviewed. Basic demands on the self-adaptation of arbitrary (normal) mutation distributions are developed. Applying arbitrary, normal mutation distributions is equivalent to applying a general, linear problem encoding. The underlying objective of mutative strategy parameter control is roughly to favor previously selected mutation steps in the future. If this objective is pursued rigorously, a completely derandomized self-adaptation scheme results, which adapts arbitrary normal mutation distributions. This scheme, called covariance matrix adaptation (CMA), meets the previously stated demands. It can still be considerably improved by cumulation - utilizing an evolution path rather than single search steps. Simulations on various test functions reveal local and global search properties of the evolution strategy with and without covariance matrix adaptation. Their performances are comparable only on perfectly scaled functions. On badly scaled, non-separable functions usually a speed up factor of several orders of magnitude is observed. On moderately mis-scaled functions a speed up factor of three to ten can be expected.

Prevalence of small inversions in yeast gene order evolution

Gene order evolution in two eukaryotes was studied by comparing the Saccharomyces cerevisiae genome sequence to extensive new data from whole-genome shotgun and cosmid sequencing of Candida albicans. Gene order is substantially different between these two yeasts, with only 9% of gene pairs that are adjacent in one species being conserved as adjacent in the other. Inversion of small segments of DNA, less than 10 genes long, has been a major cause of rearrangement, which means that even where a pair of genes has been conserved as adjacent, the transcriptional orientations of the two genes relative to one another are often different. We estimate that about 1,100 single-gene inversions have occurred since the divergence between these species. Other genes that are adjacent in one species are in the same neighborhood in the other, but their precise arrangement has been disrupted, probably by multiple successive multigene inversions. We estimate that gene adjacencies have been broken as frequently by local rearrangements as by chromosomal translocations or long-distance transpositions. A bias toward small inversions has been suggested by other studies on animals and plants and may be general among eukaryotes.

An educational implementation of a cancer pain algorithm for ambulatory care

Algorithms are proposed as a means of operationalizing guidelines or standards for cancer pain management. Professional education is used as the means to translate knowledge into practice. Outcomes measurement is the gold standard for validating improvement. This study used an educational intervention to transfer knowledge on implementing a previously tested algorithm for cancer pain management into community outpatient oncology clinics and, subsequently, measuring patient outcomes. Physicians and nurses from 9 Puget Sound clinics were randomized by institution blocks to either "training" or "no training." Role model physician/nurse teams were the core faculty for a day-long seminar. Written reference materials and documentation tools were provided to the trained physician/nurse teams. A total of 105 patients of trained and untrained providers were accrued and assessed over 4 months. Patients of trained providers had a significant reduction in usual pain over the 4 months of data collection compared with patients of untrained providers (t = 2.0; p = .05). Improvements were modest in the prescription of opioid analgesics and dramatic in the prescription of co-analgesics for neuropathic pain. There was a clear deterioration in the impact of the training over time. The most significant effect occurred within the first 140 days after the intervention and was followed by a gradual return to baseline practice. In conclusion, algorithmic interventions can be successfully transferred into community practice, but further work must be performed to develop methods for securing retention of knowledge and maintaining improved outcomes.

Intraoperative lymphatic mapping and sentinel lymph node dissection in breast cancer

Because the tumor status of the regional lymph nodes is the most important prognostic factor in patients with early-stage breast cancer, accurate histopathologic assessment of these nodes is essential for optimal management, including the selection of candidates for adjuvant systemic therapies. Intraoperative lymphatic mapping using a vital blue dye, with or without a radiocolloid, can identify the first axillary node to receive lymphatic drainage from a primary breast carcinoma. Focused histopathologic assessment of this sentinel node can be used to determine the tumor status of the entire axillary basin. The minimal morbidity and high accuracy of sentinel lymph node dissection (SLND) in breast cancer have been validated by multiple independent investigators, and the data suggest that this surgical technique may eventually replace complete lymph node dissection as the preferred axillary procedure for the management of early-stage disease. In experienced hands, SLND can be successfully performed in more than 90% of eligible breast cancer patients; the tumor status of the sentinel node accurately predicts the status of all axillary nodes in more than 95% of cases. This article reviews the current status, controversies, and future directions of SLND as a staging technique for patients with primary breast carcinoma.

Isolation and characterisation of sex-specific transcripts from Oesophagostomum dentatum by RNA arbitrarily-primed PCR

In light of the lack of molecular data on the sexual differentiation, maturation and interaction of parasitic nematodes of livestock, the present study investigated sex-specific gene expression in the nodule worm, Oesophagostomum dentatum (Strongylida). Using the technique of RNA arbitrarily-primed polymerase chain reaction (RAP-PCR), 31 expressed sequence tags (ESTs) differentially-displayed between the sexes were cloned. Northern blot analysis proved ten ESTs to be expressed exclusively in males (adults and fourth-stage larvae), while two were expressed solely in female stages. None of the ESTs were expressed in infective third-stage larvae. Sequence analysis and subsequent database searches revealed two male-specific ESTs to have significant similarity to Caenorhabditis elegans (predicted) proteins, a protein containing an EGF-like cysteine motif and a serine/threonine phosphatase. Another two male-specific ESTs had similarity to non-nematode sequences. The two female-specific ESTs had similarity to vitellogenin-5 and endonuclease III (predicted) from C. elegans. The remaining ESTs had no similarity to any nucleic acid or protein sequences contained in the databases. The isolation and characterisation of sex-specific ESTs from O. dentatum provides a unique opportunity for studying the reproductive biology of parasitic nematodes at the molecular level, with a view toward novel approaches for parasite control.

Uncoupling ceramide glycosylation by transfection of glucosylceramide synthase antisense reverses adriamycin resistance

Previous work from our laboratory demonstrated that increased competence to glycosylate ceramide conferred adriamycin resistance in MCF-7 breast cancer cells (Liu, Y. Y., Han, T. Y., Giuliano, A. E. , and M. C. Cabot. (1999) J. Biol. Chem. 274, 1140-1146). This was achieved by cellular transfection with glucosylceramide synthase (GCS), the enzyme that converts ceramide to glucosylceramide. With this, we hypothesized that a decrease in cellular ceramide glycosylation would result in heightened drug sensitivity and reverse adriamycin resistance. To down-regulate ceramide glycosylation potential, we transfected adriamycin-resistant breast cancer cells (MCF-7-AdrR) with GCS antisense (asGCS), using a pcDNA 3.1/his A vector and developed a new cell line, MCF-7-AdrR/asGCS. Reverse transcription-polymerase chain reaction assay and Western blot analysis revealed marked decreases in both GCS mRNA and protein in MCF-7-AdrR/asGCS cells compared with the MCF-7-AdrR parental cells. MCF-7-AdrR/asGCS cells exhibited 30% less GCS activity by in vitro enzyme assay (19.7 +/- 1.1 versus 27.4 +/- 2.3 pmol GC/h/microg protein, p < 0.001) and were 28-fold more sensitive to adriamycin (EC(50), 0.44 +/- 0.01 versus 12.4 +/- 0.7 microM, p < 0. 0001). GCS antisense transfected cells were also 2.4-fold more sensitive to C(6)-ceramide compared with parental cells (EC(50) = 4. 0 +/- 0.03 versus 9.6 +/- 0.5 microM, p < 0.0005). Under adriamycin stress, GCS antisense transfected cells compared with parental cells displayed time- and dose-dependent increases in endogenous ceramide and dramatically higher levels of apoptotic effector, caspase-3. Western blotting showed that adriamycin sensitivity, introduced by asGCS gene transfection, was independent of P-glycoprotein and Bcl-2 expression. In summary, this work shows that transfection of GCS antisense tempers the expression of native GCS and restores cell sensitivity to adriamycin. Therefore, limiting the potential to glycosylate ceramide, which is an apoptotic signal in chemotherapy and radiotherapy, provides a promising approach to combat drug resistance.

Learning sentinel node biopsy: results of a prospective randomized trial of two techniques

BACKGROUND

Evidence indicates that sentinel node (SN) biopsy can accurately predict axillary nodal status. Debate exists as to the optimal method of SN identification.

METHODS

Patients with clinical T1 or T2 tumors and negative axillae were randomized to SN localization with blue dye (B) alone (n = 50) or blue dye plus radioactivity (B+R) (n = 42). Patients undergoing needle localization (n = 47) were assigned to blue dye.

RESULTS

The SN was identified in 110 patients (79%) and contained metastases in 28. The SN predicted the axillary nodal status in 96% of cases. The SN identification rate did not differ between B (88%) or B+R (86%) but was significantly lower in patients requiring localization (64%). The time to SN identification also did not differ between B and B+R. The number of cases done by an individual surgeon was a significant predictor of SN identification. A stepwise logistic regression analysis of factors influencing the success of SN identification identified tumor location, needle localization, number of operations, and body mass index as significant predictors.

CONCLUSIONS

Our study does not identify any advantage for the use of the more expensive and complex method of SN identification using B+R compared with B alone, even for surgeons learning the techniques.

Optimal temperature selection for mutation detection by denaturing HPLC and comparison to single-stranded conformation polymorphism and heteroduplex analysis

BACKGROUND

Denaturing HPLC (DHPLC) is a semi-automated method for detecting unknown DNA sequence variants. The sensitivity of the method is dependent on the temperature at which the analysis is undertaken, the selection of which is dependent on operator experience. To circumvent this, software has been developed for predicting the optimal temperature for DHPLC analysis. We examined the utility of this software.

METHODS

To maximize the relevance of our data for other investigators, we have screened 42 different amplimers from CFTR, TSC1, and TSC2. The samples consisted of 103 unique sequence heterozygotes and 126 wild-type homozygous controls.

RESULTS

At the temperature recommended by the software, 96% (99 of 103) of heterozygotes and all of the wild-type controls were correctly classified. This compares favorably with sensitivities of 85% for single-stranded conformation polymorphism and 82% for gel-based heteroduplex analyses of the same fragments.

CONCLUSIONS

Software-optimized DHPLC is a highly sensitive method for mutation detection. However, where sensitivity >96% is required, our data suggest that in addition to the recommended temperature, fragments should also be run at the recommended temperature plus 2 degrees C.

Lymph node metastasis from ductal carcinoma in situ with microinvasion

BACKGROUND

Widespread use of mammography has increased the detection of ductal carcinoma in situ with microinvasion (DCISM) in pathology specimens. Currently there is disagreement regarding the incidence of axillary metastasis from DCISM. The controversy centers on whether complete lymphadenectomy is indicated for axillary staging, given its morbidity and the reportedly minimal rate of axillary involvement in these patients. Intraoperative lymphatic mapping and sentinel lymphadenectomy (SLND) may obviate complete axillary lymph node dissection in selected breast carcinoma patients. In intraoperative lymphatic mapping, isosulfan blue dye is used to demonstrate the course of lymphatic flow from the breast tumor to the first draining or sentinel lymph node. This blue-stained lymph node is selectively excised for pathologic examination; its tumor status is used to predict the tumor status of the other axillary lymph nodes. The authors examined whether SLND would be suitable for staging DCISM.

METHODS

From February 1992 to January 1997, 14 patients with DCISM underwent intraoperative lymphatic mapping and SLND at the John Wayne Cancer Institute in Santa Monica, California. Clinical and pathologic data were prospectively collected.

RESULTS

Primary DCISM tumors ranged in size from 0.9 to 6.5 cm. Nine patients presented with mammographic abnormalities, two patients presented with Paget's disease and a palpable lesion, and three patients presented with palpable lesions. Two patients (14.3%) had tumor-involved sentinel lymph nodes. One of these patients had two sentinel lymph nodes, both of which contained single cancer cells identified by immunohistochemistry. The other patient had 1 sentinel lymph node, in which a 0.3-cm metastasis was revealed by light microscopy. Completion axillary dissection was performed on both patients and revealed no further tumor positive lymph node metastases.

CONCLUSIONS

SLND can detect lymph node micrometastases (tumor deposits <2 mm) in patients with DCISM. The clinical relevance of these micrometastases is unknown, but their existence shows that DCISM can involve the lymph nodes.