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Mandibular transformations in prepubertal patients following treatment for craniofacial microsomia: thin-plate spline analysis.

To analyze correction of mandibular deformity using an inverted L osteotomy and autogenous bone graft in patients exhibiting unilateral craniofacial microsomia (CFM), thin-plate spline analysis was undertaken. Preoperative, early postoperative, and approximately 3.5-year postoperative posteroanterior cephalographs of 15 children (age 10+/-3 years) with CFM were scanned, and eight homologous mandibular landmarks digitized. Average mandibular geometries, scaled to an equivalent size, were generated using Procrustes superimposition. Results indicated that the mean pre- and postoperative mandibular configurations differed statistically (P<0.05). Thin-plate spline analysis indicated that the total spline (Cartesian transformation grid) of the pre- to early postoperative configuration showed mandibular body elongation on the treated side and inferior symphyseal displacement. The affine component of the total spline revealed a clockwise rotation of the preoperative configuration, whereas the nonaffine component was responsible for ramus, body, and symphyseal displacements. The transformation grid for the early and late postoperative comparison showed bilateral ramus elongation. A superior symphyseal displacement contrasted with its earlier inferior displacement, the affine component had translocated the symphyseal landmarks towards the midline. The nonaffine component demonstrated bilateral ramus lengthening, and partial warps suggested that these elongations were slightly greater on the nontreated side. The affine component of the pre- and late postoperative comparison also demonstrated a clockwise rotation. The nonaffine component produced the bilateral ramus elongations-the nontreated side ramus lengthening slightly more than the treated side. It is concluded that an inverted L osteotomy improves mandibular morphology significantly in CFM patients and permits continued bilateral ramus growth.

Bone Transplantation↗

18F-CPFPX PET: on the generation of parametric images and the effect of scan duration.

UNLABELLED: 8-cyclopentyl-3-(3-18F-fluoropropyl)-1-propylxanthine (18F-CPFPX) is a novel PET ligand for in vivo quantification of cerebral A1 adenosine receptors. The present study investigated the applicability of voxelwise graphical analysis to the generation of parametric images of the total volume of distribution (DVt) of 18F-CPFPX as a prerequisite for voxel-by-voxel statistical analysis. The benefit of spatial smoothing for reduction of noise-dependent negative bias in graphical analysis was examined. Additionally, the effect of scan duration on the accuracy of analyses based on volumes of interest (VOIs) and individual voxels was explored. METHODS: Ten healthy male volunteers underwent bolus-injection 18F-CPFPX PET (90 min). The data were analyzed using a 2-tissue-compartment model and graphical analysis. Voxelwise graphical analysis was performed with and without preceding spatial gaussian smoothing. RESULTS: Voxelwise graphical analysis yielded high-quality parametric images. However, voxelwise graphical analysis suffered from a negative bias (mean bias in cortical regions, -9.6% to -7.5%), which could be attenuated considerably by spatial smoothing (using a kernel of 5 mm in full width at half maximum, bias of -4.0% to -1.9%). Shortening the total scan duration to 60 min had minor effects on the accuracy of VOI-based analysis (15 VOIs x 10 subjects); the resulting error only occasionally exceeded +/-5% in individual regions (n = 6 for 2-tissue-compartment model, n = 10 for VOI-based graphical analysis, always within +/-7.5%). Quantification accuracy was acceptable with scan durations of 60 and 75 min in voxelwise graphical analysis with spatial smoothing (mean bias in cortical regions, -8.4% to -5.9%) and without spatial smoothing (bias, -9.2% to -11.6%), respectively. CONCLUSION: High-quality DVt parametric images of 18F-CPFPX can be generated by voxelwise graphical analysis. The noise-dependent negative bias of voxelwise graphical analysis is greatly reduced by spatial smoothing. A shortened scan of 60 min will enhance the clinical applicability of 18F-CPFPX PET.

Adult↗

Use of repetitive sequences and the polymerase chain reaction technique to classify genetically related Bradyrhizobium japonicum serocluster 123 strains.

We have determined that repetitive (repetitive extragenic palindromic [REP] and enterobacterial repetitive intergenic consensus [ERIC]) sequences used in conjunction with the polymerase chain reaction technique (REP and ERIC PCR) provide an effective means of differentiating between and classifying genetically related Bradyrhizobium japonicum serocluster 123 strains. Analysis of REP and ERIC PCR-generated dendrograms indicated that this technique can effectively differentiate between closely related strains which were indistinguishable by using other classification methods. To maximize the genomic differences detected by REP and ERIC PCR fingerprint patterns, the REP and the ERIC data sets were combined for statistical analyses. REP-plus-ERIC PCR fingerprints were also found to provide a method to differentiate between highly diverse strains of Bradyrhizobium spp., but they did not provide an effective means for classifying these strains because of the relatively low number of REP and ERIC consensus sequences found in some of the bradyrhizobia. Our results also suggest that there is a relationship between nodulation phenotypes and the distribution of REP and ERIC consensus sequences within the genomes of B. japonicum serogroup 123 and 127 strains. Results obtained by restriction fragment length polymorphism hybridization analyses were correlated with the phylogenetic classification of B. japonicum serocluster 123 strains obtained by using REP and ERIC PCR.

Base Sequence↗

Generalized mean-field potential description for ferroelectric ordering in nematic liquid crystals.

Ferroelectric ordering in a nematic liquid crystal system is described using a generalized mean-field potential including effective potentials for both axial and polar interactions. From a self-consistent numerical analysis, a complete phase diagram is obtained as a function of the axial and polar interaction potential strengths. The obtained phase diagram exhibits not only the usual isotropic-nematic phase transition but also nematic-ferroelectric nematic and direct isotropic-ferroelectric nematic phase transitions with a tricritical point among the phases. The phase transition behaviors and the angular orientational distribution function of the molecules were investigated by studying the dependence of the polar and the axial order parameters on the reduced temperature. Moreover, the other polar order parameters responsible for second-harmonic generation (SHG) were also investigated in the generalized mean-field potential description. As a concrete example, we performed a quantitative analysis of the SHG signal reported previously in a lyotropic poly L-glutamate system, detailing the relationship between the angular distribution function and the order parameters based on our potential model. This clarifies the nature of the ferroelectric phase responsible for SHG in nematics.

Journal Article↗

Telomere end-replication problem and cell aging.

Since DNA polymerase requires a labile primer to initiate unidirectional 5'-3' synthesis, some bases at the 3' end of each template strand are not copied unless special mechanisms bypass this "end-replication" problem. Immortal eukaryotic cells, including transformed human cells, apparently use telomerase, an enzyme that elongates telomeres, to overcome incomplete end-replication. However, telomerase has not been detected in normal somatic cells, and these cells lose telomeres with age. Therefore, to better understand the consequences of incomplete replication, we modeled this process for a population of dividing cells. The analysis suggests four things. First, if single-stranded overhangs generated by incomplete replication are not degraded, then mean telomere length decreases by 0.25 of a deletion event per generation. If overhangs are degraded, the rate doubles. Data showing a decrease of about 50 base-pairs per generation in fibroblasts suggest that a full deletion event is 100 to 200 base-pairs. Second, if cells senesce after 80 doublings in vitro, mean telomere length decreases about 4000 base-pairs, but one or more telomeres in each cell will lose significantly more telomeric DNA. A checkpoint for regulation of cell growth may be signalled at that point. Third, variation in telomere length predicted by the model is consistent with the abrupt decline in dividing cells at senescence. Finally, variation in length of terminal restriction fragments is not fully explained by incomplete replication, suggesting significant interchromosomal variation in the length of telomeric or subtelomeric repeats. This analysis, together with assumptions allowing dominance of telomerase inactivation, suggests that telomere loss could explain cell cycle exit in human fibroblasts.

Adult↗

Stratification of outcome for surgically treated unruptured intracranial aneurysms.

OBJECT: The combination of low anticipated rupture rates for many unruptured aneurysms, better delineation of treatment risks, and the availability of alternative modalities of treatment have led to heightened scrutiny of the surgical management of unruptured intracranial aneurysms. Most reports to date have provided aggregate data concerning surgical treatment risks. This study was performed to better delineate risk estimates for the surgical treatment of patients with unruptured intracranial aneurysms according to a patient's risk profile with regard to age, aneurysm location, and aneurysm size. METHODS: We studied 493 patients who were treated with surgical clipping of 604 unruptured saccular aneurysms. Information regarding aneurysm size, location, patient age, and 6-month or greater outcome were gathered prospectively from 1992 to 1999. Multivariate analysis was performed to identify independent risk factors for outcome. On the basis of the model, risk stratification curves were generated. RESULTS: In our series, the mean patient age was 53 years, and the mean lesion size was 8.8 mm. Lesion locations included the internal carotid artery (n = 259, 43%), the middle cerebral artery (n = 174, 28%), the anterior cerebral artery (n = 99, 17%), and the vertebrobasilar artery (n = 67, 11%). Multivariate analysis revealed that aneurysm size (beta = 0.122, P < 0.001), patient age (beta = 0.0308, P < 0.05), and vertebrobasilar location (beta = 1.37, P = 0.0080) were independently associated with high risk of poor outcome or death. CONCLUSION: Small aneurysms in the anterior circulation in young patients carry a very low treatment risk (approximately 1%), and treatment in elderly individuals (ages 70 years and older) with large lesions (greater than 10 mm), carries a significant risk of poor outcome (5% in the anterior circulation, 15% in the posterior circulation). The nomograms generated by this study should be particularly useful in discussing with patients the risks and benefits of surgical treatment of unruptured aneurysms.

Adult↗

What psychosocial well-being in the postnatal period means to midwives.

OBJECTIVE: to explore midwives' views of psychosocial well-being in the postnatal period. DESIGN: qualitative study using focus-group interviews conducted in 1999. SETTING: two community health centres and a school of nursing and midwifery in Scotland. PARTICIPANTS: a convenience sample of community and student midwives. ANALYSIS: thematic analysis was undertaken through the identification of codes, categories and themes. FINDINGS: the categories were generated from the interview questions: 'the meaning midwives give to women's psychosocial well-being', 'midwives' assessment of women's well-being', and 'midwives views of worrying behaviours' displayed by women. From the first two categories, themes of 'coping', 'expectations', 'observation and communication skills', 'labour debriefing', and 'previous contact with women' emerged. Midwives assessed coping and unmet expectations through a range of communication and observational skills, including the use of a form of labour debriefing. Midwives who knew women during their pregnancy thought that they were able to assess coping and expectations better in the postnatal period. The midwives tended to describe women using stereotypical categories. From the third category, 'worrying behaviours', three themes emerged; 'extreme or obsessive behaviours about self, the baby or house' 'wanting to detain you' and 'quiet women'. CONCLUSIONS: the meaning midwives give to psychosocial well-being includes a complex interplay between midwives' views of psychosocial well-being and their assessment of it. The importance midwives give to knowing women in pregnancy has implications for the ongoing debate about the provision of continuity of carer. Midwives used a range of techniques to elicit accurate information, to confirm problems or be reassured that all was well. Views based on stereotypical generalisations should be challenged.

Adaptation, Psychological↗

[Functional interrelations of brain structures in the cat during the generation of rhythmic activity. III. Cluster analysis of rhythmic indices].

The functional interrelationships of the brain structures of freely moving cats in generation of rhythmic EEG activity during the states of drowsiness and light sleep were evaluated using the claster analysis of mean values indexes of rhythms in different structures as well as correlation coefficients between them in time. It was shown that according these parameters visual cortical areas and lateral geniculate body appeared in different clusters. Lateral geniculate body suggested not to be the only pacemaker of EEG rhythms in visual cortex. The wide convergence of subcortical inputs to the visual cortex and possibility of autonomic generation of EEG rhythms at the cortical level are discussed as putative mechanisms of dissociation of EEG activities in visual cortex and thalamus.

Animals↗

A comparison of Kodak Ektaspeed Plus film and the Siemens Sidexis digital imaging system for caries detection using receiver operating characteristic analysis.

OBJECTIVE: To evaluate the accuracy of proximal caries detection comparing enhanced and unenhanced Siemens Sidexis CCD-based digital images with Ektaspeed Plus films utilizing receiver operating characteristic analysis. STUDY DESIGN: Sixty extracted teeth (24 posterior and 36 anterior) were imaged under identical standardized geometric and exposure conditions. Six observers, using a 5-point confidence scale, rated 120 proximal surfaces for the presence or absence of carious lesions by means of three image modalities: (1) observer enhanced and (2) unenhanced Sidexis displays, and (3) Ektaspeed Plus films. The ground truth was determined by microscopic analysis of ground sections. Receiver operating characteristic curves were generated with calculated areas (AZ) analyzed with analysis of variance for effect of reader, reading, and modality. RESULTS: Analysis of variance demonstrated significant differences among readers, readings and modalities (mean square values of 0.012, 0.005, 0.004, F ratios of 13.604, 5.329, 5.100; p = values of 0.001, 0.043, and 0.030, respectively). Post-hoc paired comparisons of modalities using Tukey's statistic demonstrated that only film and enhanced Sidexis images were different from each other (p = 0.024). AZ scores were 0.7650, 0.7499, and 0.8008 respectively, for unenhanced Sidexis, enhanced Sidexis, and Ektaspeed Plus film. CONCLUSION: Unenhanced digital Sidexis images were equivalent to film for the detection of proximal caries in this in vitro study. Observer enhanced Sidexis images exhibited a statistically significant lower diagnostic accuracy than the unenhanced digital and film images.

Analysis of Variance↗

[Analysis of circadian blood pressure profiles using Fourier analysis].

Blood pressure is subject to considerable circadian and situational fluctuation. In 24-h blood-pressure monitoring the severity of arterial hypertension is generally classified on the basis of the arithmetic mean of the diastolic blood pressure between 07.00 and 22.00 hours. In the present study Fourier analysis was used to generate continuous functions from the discrete blood-pressure values measured during 24-h blood-pressure monitoring in a sample of 50 normotensive persons aged from 25 to 80 years. A common reference profile was then constructed from these 50 profiles. This reference profile is characterized by the fact that the sum of the integrals over the squares of the distances between the individual profiles and the reference profile is the smallest possible. The reference profile is thus the best approximation of all normotensive profiles and practically ignores individual blood pressure fluctuations. The individual 24-h profiles of 80 patients with untreated arterial hypertension were classified on the basis of the daytime mean as mild, moderate or severe arterial hypertension and also each is described by a Fourier series. The pathological profiles were then compared with the normotensive reference profile. The comparison was made, not only with respect to the absolute pressure over 24 h, but also with respect to the circadian fluctuations in blood pressure. Comparison of the profiles shows that the Fourier analysis of 24-h blood-pressure profiles presented here permits reliable analysis and classification of arterial hypertension and can thus be used for more precise evaluation of the influence of antihypertensives on 24-h blood-pressure profiles.

Adult↗

Variance-component estimation from human sibship data.

The large-sample relative efficiencies of the analysis-of-variance (ANOVA) estimators of variance components and the intraclass correlation coefficient rho are investigated for the unbalanced single classification in the context of family studies. The efficiency of an analysis based on the method of unweighted group means is also investigated. From a Monte Carlo study which generates the group sizes from typical family-size distributions it is found that the relative efficiency of the ANOVA estimators of the between-group variance component exceeds 95% for values of .2 less than or equal to rho less than or equal to .4, but can fall below 60% for values of rho that are very close to zero. For the estimation of the between-group variance component the method of unweighted means tends to be preferable to the ANOVA method only if rho greater than .5.

Analysis of Variance↗

MoCalc: a new graphical user interface for molecular calculations.

A new computer program called MoCalc (Molecular Calculations) has been designed to help the computational chemistry practitioner in the task of performing and analyzing molecular calculations. MoCalc is a graphical user interface for the MO calculation programs Gamess and Mopac, and uses Rasmol and Babel for molecule display and file conversion, respectively. In its initial version, MoCalc can execute the following operations: (a) create and handle Gamess and Mopac input files; (b) import any kind of molecular geometry supported by Babel and paste it as Cartesian, internal, or Gaussian-type coordinates on the input file; (c) convert Gamess and Mopac output files to inputs of both programs; (d) edit and validate the keywords that control the Gamess and Mopac calculation procedure; (e) display the input (Mopac) and output (Gamess and Mopac) molecular geometries; (f) run single or multiple (batch) calculations, either interactively or in background; (g) automatically open the output files as soon as the calculation finishes; (h) extract results from the output files, such as energy, charges, dipole, population analysis, wave function, bond orders, and valence analysis, and display them in spreadsheets; (i) calculate reactivity indices derived from the frontier orbital theory and the root-mean-square (rms) deviation of input and output geometries. All the results generated by MoCalc can be promptly transferred to text editors and electronic spreadsheets, which facilitate a detailed subsequent analysis and the publication of the results. MoCalc can also perform graphical and numerical comparative analysis of the some results when more than one output file is loaded. The program was coded in Visual Basic and runs in Windows 95/98/NT4/ME/2000/XP environments.

Journal Article↗

Patient, surgeon, and treatment characteristics associated with homologous blood transfusion requirement during radical retropubic prostatectomy: multivariate nomogram to assist patient counseling.

OBJECTIVES: To identify the preoperative patient, treatment, and surgeon factors associated with the administration of homologous blood transfusion during or after radical retropubic prostatectomy (RRP) to be able to better inform patients regarding the probability of transfusion. Homologous blood transfusion is sometimes required during or after RRP, but predictive models for estimating transfusion probability using patient and surgical characteristics are lacking. METHODS: Data were prospectively collected regarding patient characteristics, cancer severity, surgeon experience, anesthetic used, operative blood loss, and transfusion among 1123 consecutive RRP cases. Multivariate regression analysis identified baseline factors associated with a homologous transfusion requirement and generated a model for predicting the likelihood of perioperative homologous transfusion. RESULTS: Homologous transfusion was administered in 3.8% of subjects; the mean estimated blood loss was 953 mL. Multivariable regression analysis identified prostate size (P <0.0001, odds ratio [OR] 1.74), use of general anesthesia (P = 0.01, OR 2.22), use of neoadjuvant hormonal therapy (P = 0.006, OR 3.35), and surgeon expertise (P <0.0001, OR 8.63) as independent risk factors associated with a need for perioperative homologous transfusion. The most influential factor, surgical expertise, clustered among surgeons who performed more than 15 RRPs annually, because these surgeons had lower transfusion rates and lower estimated blood loss more consistently than did surgeons who performed fewer RRPs annually. CONCLUSIONS: Larger prostate size, use of general anesthesia, use of neoadjuvant hormonal therapy, and annual surgeon case volume were independently associated with an increased probability that an individual patient would receive homologous transfusion during or after RRP. A nomogram indicating the probability of homologous transfusion based on these factors provides a benchmark of expected homologous transfusion rates according to individual patient and treatment parameters.

Adenocarcinoma↗

Estimation of land use specific runoff and pollutant concentration for Tapi River basin in India.

Non-point source (NPS) pollution is the result of various land use practices such as agriculture, sites of construction and waste disposal, urban development and so on. The control of NPS pollution is possible by regular monitoring and assessment on watershed basis to educate people for implementing well-known structural and non-structural measures. Recent trend is to use GIS based modelling tool for assessment of rainfall-runoff and non-point loading. The approach requires generation and analysis of basin wide data on various features of land and estimates of Event Mean Concentrations (EMCs) of pollutants in the runoff. In the present paper, basin wide data in different districts of Tapi basin has been analysed for land use distribution; fertilizer application; low, medium and high-density habitation; and annual rainfall. Coefficients of runoff have been estimated considering pervious and impervious area for different land use types, and compared with the reported values for Indian conditions. The estimated mean annual runoff flow indicated that two districts Jalgaon and Dhule contribute maximum runoff to the Tapi River. Estimates of EMCs for BOD and nutrients (N and P) in the runoff from various districts are useful in GIS-based modelling study for NPS pollution assessment.

Agriculture↗

Effect of age on visuomotor functional MR imaging.

RATIONALE AND OBJECTIVES: We sought to determine the effect of age on functional MR imaging experiments performed with visual and motor stimulation. We hypothesized that there would be a diminution in the amplitude of fMRI activation with increasing subjects' age. MATERIALS AND METHODS: We used fixed effects models to study the amplitude of activation during a block design visuomotor task in three different age groups: old (mean: 75 years; standard deviation: 6 years), middle-aged (mean: 52 years; standard deviation: 9 years) and young (mean: 29 years; standard deviation: 5 years). Each group included 7 subjects. Regions of interest (ROI) were left primary motor area (LM1), supplementary motor area (SMA), and right and left occipital (RO, LO) visual areas. Individual subjects and group statistical parametric maps (SPMs) were generated for each ROI, and then the mean amplitude of activation was compared using the group analysis and t test. RESULTS: The young age group showed higher amplitude of activation than middle and old age groups in all ROI (P < 0.01 uncorrected). Unpaired two tailed t test results between the groups showed significant differences between middle and young, and old and young age groups in all ROIs (P < or = 0.05), with the exception of old and young age groups in RO region (P = 0.11). CONCLUSION: The group analysis, and unpaired t test results reveal higher amplitude of fMRI activation in the young versus the old and middle-aged groups.

Adult↗

The repeatability of superovulatory response and embryo recovery in sheep.

Over an 8-year period, a total of 328 Scottish Blackface donor ewes were involved in a MOET program. They were synchronized with fluorogestone acetate sponges and superovulated with ovine FSH. After the onset of estrus, ewes were hand-mated and laparoscopic artificial insemination was performed with fresh semen 44-46 h after sponge removal. Embryos were recovered semi-laparoscopically on either Day 5 or Day 6 after insemination. Of the 328 donor ewes used, 222 ewes were supervoulated only once, while the remaining ewes were superovulated either twice (73 ewes), 3 times (26 ewes) or 4 times (7 ewes) at yearly intervals to generate a maximum of 474 records for subsequent analysis. There was no significant change in either mean ovulation rate or the mean number of embryos recovered per donor ewe at successive treatments. However, significant (P < 0.05 at least) effects of both year and donor ewe age existed for superovulatory response and number of embryos recovered, though only the effect of year was significant (P < 0.001) for percentage embryo recovery. Repeatability was significant (P < 0.05 at least) for both superovulatory response (r = 0.55, s.e. 0.055) and number of embryos recovered (r = 0.38, SE 0.074), but not for percentage embryo recovery (r = 0.04, SE 0.102).

Age Factors↗

Clinical application of the Personal Dialysis Capacity (PDC) test: serial analysis of peritoneal function in CAPD patients.

BACKGROUND: Peritoneal damage has been reported since the beginning of CAPD therapy. METHODS: To clarify the change of peritoneal function in CAPD patients, we used the Personal Dialysis Capacity (PDC) test in 22 patients with 49 serial studies and 14 patients with single studies. The data were expressed at the condition of 2.5% (2.27 g/dl of glucose), four times at 2,000 ml/day. RESULTS: In the mass analysis, the urea generation rate, creatinine generation rate, PNA/PCR, and water removal via the peritoneum (PD) were kept at the same level for almost eight years, and then gradually decreased. Urine volume and residual renal creatinine clearance (CCr) became zero at six years. On the other hand, PD CCr increased gradually with the time course of CAPD, and therefore the total CCr remained at the level of 6.0 ml/min even after six years. Weekly urea KT/V decreased gradually from almost 2.800 to 2.000. The protein loss remained approximately 7.0 g/day for the initial five years, then became 6.0 g/day, except in five patients who showed levels above 10.0 g/day on the first test of PDC. Weekly urea KT/V was correlated with residual renal CCr (P < 0.005), and significantly correlated with total CCr (weekly urea KT/V = -0.2798 + 0.3720 x total CCr; r = 0.915, P < 0.001). In the serial analysis, when the first and the last tests were compared, the urea generation rate increased significantly (mean +/- SD, 2.800 +/- 3.204 vs. 3.882 +/- 3.382; P < 0.0001); however, water removal via PD (1364 +/- 887 vs. 813 +/- 609; P = 0.021), total ultrafiltration (1762 +/- 841 vs. 1124 +/- 843; P = 0.042), and weekly urea KT/V (2.285 +/- 0.486 vs. 2.112 +/- 0.512; P = 0.026) decreased significantly. The delta water removal via PD/ duration became negative (-10.03 +/- 6.59 ml/week) in all 7 patients after more than four years, however, it was positive (+14.40 +/- 7.84 ml/week) in 6 of 10 patients after less than one year. CONCLUSION: These results suggest that water removal via PD increases within one year, then decreases after four years. The PDC test is useful to evaluate the change of peritoneal function in mass and serial analyses.

Adult↗

Efficient and genotype-independent Agrobacterium--mediated tomato transformation.

An efficient method to transform five cultivars of tomato (Lycopersicon esculentum), Micro-Tom, Red Cherry, Rubion, Piedmont, and E6203 is reported. A comparison was made of leaf, cotyledon, and hypocotyl explants on 7 different regeneration media without Agrobacterium tumefaciens cocultivation and on 11 different media with cocultivation. Although all cultivars and explants formed callus and regenerated on the initial 7 media, cocultivation with A. tumefaciens significantly reduced the callus induction and regeneration. From these experiments, a transformation methodology using either hypocotyls or cotyledons cultured for one day on BA 1 mgL-1, NAA 0.1 mgL-1 and 3 days cocultivation with the Agrobacterium on this same medium followed by a transfer to a medium with zeatin 2 mgL-1 and IAA 0.1 mgL-1 for 4-6 weeks resulted in a greater than 20% transformation frequency for all five cultivars tested. In this transformation method, no feeder layers of tobacco, petunia or tomato suspension cultures were used, and the subculture media was minimal. Stable integration and transmission of the transgene in T1 generation plants were confirmed by Southern blot analysis. This procedure represents a simple, efficient and general means of transforming tomato.

Culture Media↗