Use of Bayesian networks in forensic soil casework.

Forensic soil comparisons can be of high evidential value in a forensic case, but become complex when multiple methods and factors are considered. Bayesian networks are well suited to support forensic practitioners in complex casework. This study discusses the structure of a Bayesian network, elaborates on the in- and output data and evaluates two examples, one using source level propositions and one using activity level propositions. These examples can be applied as a template to construct a case specific network and can be used to assess sensitivity of the target output to different factors and identify avenues for research.

Cancer spectrum and frequency among children with Noonan, Costello, and cardio-facio-cutaneous syndromes.

BACKGROUND: Somatic mutations affecting components of the Ras-MAPK pathway are a common feature of cancer, whereas germline Ras pathway mutations cause developmental disorders including Noonan, Costello, and cardio-facio-cutaneous syndromes. These 'RASopathies' also represent cancer-prone syndromes, but the quantitative cancer risks remain unknown. METHODS: We investigated the occurrence of childhood cancer including benign and malignant tumours of the central nervous system in a group of 735 individuals with germline mutations in Ras signalling pathway genes by matching their information with the German Childhood Cancer Registry. RESULTS: We observed 12 cases of cancer in the entire RASopathy cohort vs 1.12 expected (based on German population-based incidence rates). This corresponds to a 10.5-fold increased risk of all childhood cancers combined (standardised incidence ratio (SIR)=10.5, 95% confidence interval=5.4-18.3). The specific cancers included juvenile myelomonocytic leukaemia=4; brain tumour=3; acute lymphoblastic leukaemia=2; rhabdomyosarcoma=2; and neuroblastoma=1. The childhood cancer SIR in Noonan syndrome patients was 8.1, whereas that for Costello syndrome patients was 42.4. CONCLUSIONS: These data comprise the first quantitative evidence documenting that the germline mutations in Ras signalling pathway genes are associated with increased risks of both childhood leukaemia and solid tumours.

Psychosocial outcome following genetic risk counselling for familial colorectal cancer. A comparison of affected patients and family members.

Few studies have reported prospective data on psychosocial outcomes after genetic counselling in families with suspected hereditary non-polyposis colorectal cancer (HNPCC). This prospective study examines the impact of multidisciplinary risk counselling on the psychosocial outcome of 139 affected cancer patients and 233 family members without cancer at risk for HNPCC. Participants completed questionnaires specific to HNPCC before and 8 weeks after attending the familial cancer clinic. Affected patients' levels of distress were closely related to their health status and exceeded that of unaffected individuals, as did worry regarding their relatives' risk. A significant reduction in general anxiety (Hospital Anxiety and Depression Scale), distress specific to familial CRC (Impact of Events Scale) and general cancer worry (Distress Hereditary Disorder) was demonstrated after counselling in both affected patients and unaffected individuals. Reduction in distress was more pronounced in affected patients given a high risk of HNPCC compared with those at intermediate risk. Among unaffected individuals, distress declined regardless of what clinical risk they were assigned. Their perceptions of risk and cancer-related threat declined, while confidence in effective surveillance increased. These results suggest the beneficial effects of multidisciplinary counselling even when high-risk information is conveyed. A patient's previous cancer experience is likely to contribute to clinically relevant distress (15% of those patients), indicating the need for appropriate counselling.

Lack of CD56 expression on myeloma cells is not a marker for poor prognosis in patients treated by high-dose chemotherapy and is associated with translocation t(11;14).

Lack of CD56 expression was reported to be associated with a poor prognosis in multiple myeloma (MM) patients treated with conventional chemotherapy. Aim of our retrospective study was to analyse whether CD56 expression on MM cells reveals as a prognostic factor in patients treated with high-dose chemotherapy. MM cells of 99 patients prior to treatment with high-dose chemotherapy were analysed for CD56 expression by flow cytometry. Multivariable analysis of event-free survival in these patients showed no statistically significant difference between the CD56(-) (n=28) and the CD56(+) (n=71) group. The lack of CD56 expression on MM cells of these patients correlated significantly with the presence of translocation (11;14) (t(11;14)) (estimated correlation coefficient=0.655 95%, confidence interval (0.481; 0.779)). In summary, our results indicate that lack of CD56 expression on MM cells is not a prognostic marker in patients treated with high-dose chemotherapy, but is associated with t(11;14).

Thalidomide in newly diagnosed multiple myeloma: influence of thalidomide treatment on peripheral blood stem cell collection yield.

In a phase III randomized, multicenter study, the German-speaking Myeloma-Multicenter Group (GMMG) and the Dutch-Belgian Hemato-Oncology Cooperative Group (HOVON) group investigated the influence of thalidomide (Thal) on the outcome of peripheral blood stem cell (PBSC) collection in multiple myeloma (MM) before peripheral autologous blood stem cell transplantation (ABSCT). We analyzed the data of 398 myeloma patients after induction with Thal, doxorubicin and dexamethasone (TAD) in comparison with vincristine, doxorubicin and dexamethasone (VAD) followed by mobilization with cyclophosphamide, doxorubicin, dexamethasone (CAD) and PBSC collection. Within both the study groups, patients treated with TAD showed to collect significantly fewer CD34(+) cells compared with VAD (GMMG, TAD: median 9.8 x 10(6)/kg; range 2.0-33.6; VAD: median 10.9 x 10(6)/kg range 3.0-36.0; P=0.02) (HOVON, TAD: median 7.4 x 10(6)/kg; range 2.0-33.0; VAD: median 9.4 x 10(6)/kg; range 0.0-48.7; P=0.009). However, engraftment after peripheral autologous stem cell transplantation showed no difference between Thal and VAD groups. We conclude that Thal as a part of induction regimen is associated with better response rates (GMMG-HD3: CR/PR 79%, VAD: CR/PR 58%; HOVON-50: TAD: CR/PR 81%, VAD: CR/PR 61%), but significantly affects the yield of PBSC collection. Nevertheless, the number of total CD34(+) cells collected was sufficient for double autologous transplantation in 82% of the Thal patients, with at least 2.5 x 10(6)/kg CD34(+) cells.

Preoperative elevation of serum C--reactive protein is predictive for prognosis in myeloma bone disease after surgery.

We investigated whether preoperative levels of serum C-reactive protein (CRP) and its correlation with tumour clinicopathological findings adds prognostic information beyond the time of diagnosis in patients with myeloma bone disease (MM) to facilitate the surgical decision-making process. Six hundred and fifty-eight myeloma patients were evaluated retrospectively for surgery. Clinicopathological variables of patients who underwent surgery (n=71) were compared between patients with preoperative CRP>or=6 mg l-1 and those with CRP<6 mg l-1. Univariate and multivariate analyses were performed to identify prognostic factors after surgery. Patients with an increase of CRP prior to surgery showed inferior survival compared to patients with normal levels. Patients with normal CRP levels at diagnosis but elevations prior to surgery do seem to have a similar unfavourable overall survival (OS) than patients with an increase both, at diagnosis and at surgery. Conversely, patients with normal CRP levels prior to surgery still have the best OS, irrespective of their basic values. Multivariate analysis revealed preoperative CRP levels above 6 mg l-1 Lactate dehydrogenase (LDH) above normal, and osteolyses in long weight bearing bones as independent predictors of survival. These findings suggest that in patients with MM serum levels of CRP increase during disease activity and might be significantly correlated with specific disease characteristics including adverse prognostic features such as osteolyses in long weight bearing bones. Thus, preoperative elevated CRP serum levels might be considered as independent predictor of prognosis and could provide additional prognostic information for the risk stratification before surgical treatment in patients with myeloma bone disease.

Chromosomal aberrations in 130 patients with multiple myeloma studied by interphase FISH: diagnostic and prognostic relevance.

The study described the molecular cytogenetic characterization of myeloma cells in 130 patients via interphase fluorescence in situ hybridization. Nine repetitive DNA probes (for chromosomes 3, 7, 9, 11, 15, 17, 18, X, and Y) as well as seven single-copy DNA probes (for chromosomes 13, 17, 21, and two each for chromosomes 5 and 22) were used for the hybridizations. Using this panel of probes, we were able to show aberrations in 86% of patients. Most of them had one to three aberrations. There was a distinct correlation between the number of aberrations per patient and the tumor stage. Thus, the proportion of patients with 8-12 aberrations increased from 16% in stage II to 26% in stage III. There were marked differences among the chromosomes with respect to the prevalence of genomic losses and gains and deletions of gene loci. Chromosomes 3, 5, 7, 9, 11, 15, and 21 showed a preference for genomic gains. Losses were most often found for chromosomes 13 and 17 (locus specific) as well as for the X and Y chromosomes. The frequency of monosomies and trisomies were approximately the same for chromosomes 15 and 18, which indicates a skewed pattern of distribution. We found two specific aberrations that caused distinct changes in the survival rates of the patients: deletion 13q14 (28% of patients) and translocation of the IGH locus 14q32 (79% of 39 patients who were analyzed separately). The results obtained in this study yielded data of extremely relevant prognostic value.

Heparan sulphate proteoglycans are essential for the myeloma cell growth activity of EGF-family ligands in multiple myeloma.

The epidermal growth factor (EGF)/EGF-receptor (ErbB1-4) family is involved in the biology of multiple myeloma (MM). In particular, ErbB-specific inhibitors induce strong apoptosis of myeloma cells (MMC) in vitro. To delineate the contribution of the 10 EGF-family ligands to the pathogenesis of MM, we have assessed their expression and biological activity. Comparing Affymetrix DNA-microarray-expression-profiles of CD138-purified plasma-cells from 65 MM-patients and 7 normal individuals to those of plasmablasts and B-cells, we found 5/10 EGF-family genes to be expressed in MMC. Neuregulin-2 and neuregulin-3 were expressed by MMC only, while neuregulin-1, amphiregulin and transforming growth factor-alpha were expressed by both MMC and normal plasma-cells. Using real-time polymerase chain reaction, we found HB-EGF, amphiregulin, neuregulin-1 and epiregulin to be expressed by cells from the bone marrow-environment. Only the EGF-members able to bind heparan-sulphate proteoglycans (HSPGs) - neuregulin-1, amphiregulin, HB-EGF - promote the growth of MMC. Those ligands strongly bind MMC through HSPGs. The binding and the MMC growth activity was abrogated by heparitinase, heparin or deletion of the HS-binding domain. The number of HS-binding EGF ligand molecules bound to MMC was higher than 10(5) molecules/cell and paralleled that of syndecan-1. Syndecan-1, the main HSPG present on MM cells, likely concentrates high levels of HS-binding-EGF-ligands at the cell membrane and facilitates ErbB-activation. Altogether, our data further identify EGF-signalling as promising target for MM-therapy.

Molecular monitoring of tumour load kinetics predicts disease progression after non-myeloablative allogeneic stem cell transplantation in multiple myeloma.

BACKGROUND: Non-myeloablative allogeneic stem cell transplantation followed by immunomodulatory therapies is considered a potentially curative approach in the treatment of multiple myeloma and most effective in a minimal residual disease setting. PATIENTS AND METHODS: The aim of this study was to find the most sensitive real-time PCR assay (TaqMan), based on the IGH rearrangement, to quantify the tumour load of 11 patients with multiple myeloma after non-myeloablative allogeneic transplantation. Patient-allele specific primers (ASO) and the TaqMan probe were derived from CDR2 and CDR3 hypervariable regions of IGH, while consensus primers were located within the FR3 and FR4/JH regions. Four different approaches of primer combinations were tested. RESULTS: ASO-forward and -reverse primers together with the clone-specific TaqMan probe were the most sensitive approach compared with the JH (P=0.071) or the FR3 consensus primer (P <0.001). The detection limit amounted to 1/10(4)-1/10(5) cells. Consecutively, 120 samples from 11 patients prior and post allogeneic transplantation were analysed. Three patients reached complete clinical remission accompanied by molecular remission. Disease progression or relapse was seen in six patients. In five, molecular progressive disease was detected prior to the clinical diagnosis of progression or relapse. CONCLUSION: Patient-specific real-time IGH-PCR provides the opportunity for earlier treatment intervention.

Long-term survival after surgical intervention for bone disease in multiple myeloma.

BACKGROUND: We describe the surgical treatment, outcome and long-term survival of patients with multiple myeloma (MM) in response to conventional (CC) or high-dose (HDT) chemotherapy. PATIENTS AND METHODS: Eighty-four patients diagnosed with MM were recruited for the study (51 male, 33 female; median age 62 years) and consecutively surgically treated in a single institution during a 12-year period. The main end point of the study was overall survival after surgery. Cox regression analysis was used to estimate the effect of factors that may predict survival. RESULTS: Spinal surgery was performed in 54 cases, and 30 patients were surgically treated at the extremities. The post-surgical complication rate was low (17%; 14/84 patients). The median overall survival time was 47 months. Patients receiving HDT had a longer 5-year overall survival rate than patients receiving CC (51% versus 33%). Univariate predictors of mortality included age >65 years [risk ratio (RR) 1.62; P=0.023], osteolyses in long weight-bearing bones (RR 2.23; P=0.007) and an elevated C-reactive protein level >5 mg/l (RR 1.82; P=0.016); the latter remained significant as a predictor in multivariate analysis (RR 2.66; P=0.0209). CONCLUSIONS: Given the high number of patients reaching 5-year overall survival and the low post-surgery complication rate, surgery should pursue a long-term stable reconstruction of the affected bone.

[Multiple myeloma. Diagnosis and therapy]. / Multiples Myelom. Diagnostik und Therapie.

Multiple myeloma is one of the 20 most frequent malignancies in Germany. Initial symptoms are usually non-specific. Assessment of bone marrow and laboratory data as well as imaging techniques are essential for diagnosis and prognostic evaluation. Data from molecular cytogenetics have led to a better understanding of the pathogenesis of multiple myeloma. Cytostatic therapy with alcylating agents and glucocorticoids prolongs the survival. High-dose therapy followed by transplantation of autologous hematopoietic stem cells improves prognosis for patients up to the age of 70. Currently, modifications of allogeneic hematopoietic stem cell transplantation, anti-angiogeneic and immunomodulatory drugs as well as proteasome inhibitors are evaluated in clinical trials. Supportive care has derived benefit from the introduction of new bisphosphonates.

Bisphosphonates in multiple myeloma.

BACKGROUND: Multiple myeloma is a disease characterized by the neoplastic proliferation of a clone of plasma cells that can lead to bone destruction. Bisphosphonates are specific inhibitors of osteoclastic activity. Therefore, there is a pharmacological basis for their use in multiple myeloma. However, the exact clinical role of bisphosphonates in multiple myeloma remains unclear. OBJECTIVES: Primary: to determine whether adding bisphosphonates to standard therapy in multiple myeloma decreases skeletal-related morbidity (pathological fractures), skeletal-related mortality and overall mortality. Secondary: to determine the effects of bisphosphonates on pain, quality of life and incidence of hypercalcemia. SEARCH STRATEGY: We searched MEDLINE (1966 - June 2001), LILACS (1982 - June 2001), EMBASE (1974 - December 2000) and the Cochrane Controlled Trials Register (all years, latest Issue 03/2001) to identify all randomized trials in multiple myeloma. All of these references were accessed in order to identify trials related to the use of bisphosphonates in myeloma. All relevant references in each article were also scanned. We also performed a handsearch of relevant meeting proceedings from 1993 to 2000. Additionally, manufacturers of bisphosphonates and researchers in the field were contacted. SELECTION CRITERIA: Randomised trials with a parallel design on the use of bisphosphonate in myeloma compared with placebo or no treatment as a control group. DATA COLLECTION AND ANALYSIS: Two reviewers independently assessed trial eligibility, methodological quality and abstracted data. A third reviewer checked all data after the extraction was completed. Statistical heterogeneity was tested using random and fixed effect models. All pooled data are reported using Peto odds ratios and, when appropriate, as absolute risk reduction and the number needed to treat to prevent or to cause a pathological event. MAIN RESULTS: Eleven trials were included with 1113 patients analysed in bisphosphonates groups, and 1070 analysed in control groups. There was no significant statistical heterogeneity among trials for the endpoints selected for comparison in this review. The pooled analysis of the published evidence demonstrated the beneficial effect of bisphosphonates on prevention of pathological vertebral fractures [OR=0.59 (95% confidence interval (CI) 0.45-0.78); P=0.0001] and on amelioration of pain [OR = 0.59 (95%CI 0.46-0.76); P=0.00005]. However, the analysis of the effect of bisphosphonates on pain was based on clinically heterogeneous data and must be interpreted with caution. Although there was no statistical heterogeneity between groups, the benefit was most apparent with clodronate and pamidronate. In absolute terms, the result may be interpreted to mean that 10 (95%CI 7-20) patients with multiple myeloma should be treated to prevent one vertebral fracture, and 11 (95%CI 7-28) to prevent one patient experiencing pain. We found no significant effect of bisphosphonates on mortality, on the reduction of non-vertebral fractures or on the incidence of hypercalcemia. There were no significant adverse effects associated with the administration of bisphosphonates. Our results are based on the extraction of published data, which were sometimes poorly reported, and thus the results should be understood as the best possible summation of available evidence. REVIEWER'S CONCLUSIONS: Adding bisphosphonates to the treatment of myeloma reduces pathological vertebral fractures and pain but - from the published evidence - not mortality. On current evidence, clodronate or pamidronate may be the preferred agents.

Anti-CD20 antibody as consolidation therapy in a patient with primary plasma cell leukemia after high-dose therapy and autologous stem cell transplantation.

In multiple myeloma (MM), circulating malignant B cells are proposed as the proliferative compartment of the disease. In view of the close relationship between multiple myeloma and primary plasma cell leukemia (PCL), an anti-CD20 antibody treatment might also be considered as consolidation for patients with PCL. A 55-year-old patient diagnosed with PCL achieved complete remission after autologous transplantation. A total of four weekly courses of rituximab (375 mg/m(2)) were administered. Prior to antibody therapy, CD20+ cells comprised 22.6% of the mononuclear cells in peripheral blood (PB) assessed by flow cytometry and were enriched by magnetic activated cell sorting (MACS). In the enriched CD20+ fraction, 0.093% clonotypic cells were detected using a quantitative polymerase chain reaction (PCR) assay based on limiting dilutions. The proportion of clonotypic cells was 0.034% in PB and 0.032% in bone marrow (BM). Rituximab depleted CD20+ cells completely in PB and BM. Tumor load in PB and BM at day 40 and in PB at day 70 did not change in comparison to prior to therapy (0.037% in PB, 0.026% in BM). At day 90, the tumor load increased to 0.066% in PB. At day 120, the patient relapsed with 0.65% CD38++/CD138+/CD20- plasma cells and furthermore no CD20+ B cells in PB. The expansion of plasma cells was accompanied by an increase in the tumor load in both compartments (PB: 0.65%, BM: 1.8%). The accumulation of plasma cells during disease progression without the reappearance of CD20+ cells did not sustain the role of circulating clonotypic B cells as proliferative compartment in our patient. However, it cannot be excluded that rituximab was not able to eradicate malignant B cells, which subsequently contributed to relapse.

Comprehensive genetic counseling for families at risk for HNPCC: impact on distress and perceptions.

The aim of the study was to explore distress and health beliefs before and after comprehensive interdisciplinary counseling in families at risk for hereditary non-polyposis colorectal cancer (HNPCC). Results reported here were derived from a consecutive sample of 65 counselees [31 patients with colorectal cancer (CRC) and 34 unaffected at-risk persons] who participated in interdisciplinary counseling provided by human geneticists, surgeons, and psycho-oncologists before genetic testing. Data were collected from self-administered questionnaires before, as well as 4-6 weeks after, counseling. Distress and perceptions specific to HNPCC were assessed at both timepoints using standardized as well as author-derived instruments. Distress declined after counseling, as did worries related to HNPCC. An increase was found in personal belief in control of cancer risk, for instance, in the perceived efficacy of early detection of CRC. We also observed a trend toward greater anticipated ability to cope with a positive gene test after counseling. Changes after counseling were generally more pronounced for persons at risk, as compared to patients with cancer. The decrease in distress was partly attributable to an increase in personal self-confidence. One-third of the sample reported enhanced communication specific to hereditary disease within the family after counseling. A substantial minority, however, said they experienced increased worry and physical symptoms after counseling. Overall, counselees demonstrated less stress and perceived cancer threat as well as enhanced beliefs regarding personal control over cancer, suggesting an overall beneficial impact of comprehensive counseling. Further research is needed to identify those individuals most at risk for increased fear and worry related to HNPCC so that they may be most appropriately counseled.

Molecular monitoring of the tumor load predicts progressive disease in patients with multiple myeloma after high-dose therapy with autologous peripheral blood stem cell transplantation.

The clinical relevance of the assessment of minimal residual disease (MRD) in patients with multiple myeloma (MM) to predict disease recurrence has not been proven. In the present study, we retrospectively analyzed the tumor load in peripheral blood (PB) and bone marrow (BM) samples of 13 patients with MM both in remission after high-dose therapy (HDT) with autologous PBSC transplantation (PBSCT) and at the time of progressive disease (PD). For six patients, subsequent samples obtained in remission could be included in the study. Tumor cells were assessed by means of quantitative PCR with allele-specific oligonucleotides (ASO-qPCR) based on the method of limiting dilutions. PD was documented with ASO-qPCR in BM samples (median concentration of tumor cells in remission vs at PD: 0.18% vs 4.6%) representing a significant increase by a median factor of 8.7. In PB, the median tumor load was 799 cells/ml in remission and 23 400 cells/ml at PD. With a median factor of 45, the increase was much more pronounced. Comparing the results of the molecular monitoring in PB with those of the determination of the monoclonal protein, routinely applied as parameter for the course of the disease, revealed a superiority of the molecular monitoring because of the significantly higher increase in the tumor load. Analyzing the subsequent remission samples showed an increase of the malignant cells in four out of six PB samples and in all four BM samples available, indicating the potential of ASO-qPCR for an early PD recognition.

Bisphosphonates in multiple myeloma.

BACKGROUND: Multiple myeloma is a disease characterized by the neoplastic proliferation of a clone of plasma cells that can lead to bone destruction. Bisphosphonates are specific inhibitors of osteoclastic activity. Therefore, there is a pharmacological basis for their use in multiple myeloma. However, the exact clinical role of bisphosphonates in multiple myeloma remains unclear. OBJECTIVES: Primary: to determine whether adding bisphosphonates to standard therapy in multiple myeloma decreases skeletal-related morbidity (pathological fractures), skeletal-related mortality and overall mortality. Secondary: to determine the effects of bisphosphonates on pain, quality of life and incidence of hypercalcemia. SEARCH STRATEGY: We searched MEDLINE (1966 - June 2001), LILACS (1982 - June 2001), EMBASE (1974 - December 2000) and the Cochrane Controlled Trials Register (all years, latest Issue 03/2001) to identify all randomized trials in multiple myeloma. All of these references were accessed in order to identify trials related to the use of bisphosphonates in myeloma. All relevant references in each article were also scanned. We also performed a handsearch of relevant meeting proceedings from 1993 to 2000. Additionally, manufacturers of bisphosphonates and researchers in the field were contacted. SELECTION CRITERIA: Randomised trials with a parallel design on the use of bisphosphonate in myeloma compared with placebo or no treatment as a control group. DATA COLLECTION AND ANALYSIS: Two reviewers independently assessed trial eligibility, methodological quality and abstracted data. A third reviewer checked all data after the extraction was completed. Statistical heterogeneity was tested using random and fixed effect models. All pooled data are reported using Peto odds ratios and, when appropriate, as absolute risk reduction and the number needed to treat to prevent or to cause a pathological event. MAIN RESULTS: Eleven trials were included with 1113 patients analysed in bisphosphonates groups, and 1070 analysed in control groups. There was no significant statistical heterogeneity among trials for the endpoints selected for comparison in this review. The pooled analysis of the published evidence demonstrated the beneficial effect of bisphosphonates on prevention of pathological vertebral fractures [OR=0.59 (95% confidence interval (CI) 0.45-0.78); P=0.0001] and on amelioration of pain [OR = 0.59 (95%CI 0.46-0.76); P=0.00005]. However, the analysis of the effect of bisphosphonates on pain was based on clinically heterogeneous data and must be interpreted with caution. Although there was no statistical heterogeneity between groups, the benefit was most apparent with clodronate and pamidronate. In absolute terms, the result may be interpreted to mean that 10 (95%CI 7-20) patients with multiple myeloma should be treated to prevent one vertebral fracture, and 11 (95%CI 7-28) to prevent one patient experiencing pain. We found no significant effect of bisphosphonates on mortality, on the reduction of non-vertebral fractures or on the incidence of hypercalcemia. There were no significant adverse effects associated with the administration of bisphosphonates. Our results are based on the extraction of published data, which were sometimes poorly reported, and thus the results should be understood as the best possible summation of available evidence. REVIEWER'S CONCLUSIONS: Adding bisphosphonates to the treatment of myeloma reduces pathological vertebral fractures and pain but - from the published evidence - not mortality. On current evidence, clodronate or pamidronate may be the preferred agents.

The delayed terminal flower phenotype is caused by a conditional mutation in the CENTRORADIALIS gene of snapdragon.

The snapdragon (Antirrhinum majus) centroradialis mutant (cen) is characterized by the development of a terminal flower, thereby replacing the normally open inflorescence by a closed inflorescence. In contrast to its Arabidopsis counterpart, terminal flower1, the cen-null mutant displays an almost constant number of lateral flowers below the terminal flower. Some partial revertants of an X-radiation-induced cen mutant showed a delayed formation of the terminal flower, resulting in a variable number of lateral flowers. The number of lateral flowers formed was shown to be environmentally controlled, with the fewer flowers formed under the stronger flower-inducing conditions. Plants displaying this "Delayed terminal flower" phenotype were found to be heterozygous for a mutant allele carrying a transposon in the coding region and an allele from which the transposon excised, leaving behind a 3-bp duplication as footprint. As a consequence, an iso-leucine is inserted between Asp148 and Gly149 in the CENTRORADIALIS protein. It is proposed that this mutation results in a low level of functional CEN activity, generating a phenotype that is more similar to the Arabidopsis Terminal flower phenotype.