Comparative phylogenomics and phylotranscriptomics provide insights into the genetic complexity of nitrogen-fixing root-nodule symbiosis

Plant root-nodule symbiosis (RNS) with mutualistic nitrogen-fixing bacteria is restricted to a single clade of angiosperms, the Nitrogen-Fixing Nodulation Clade (NFNC), and is best understood in the legume family. Nodulating species share many commonalities, explained either by divergence from a common ancestor over 100 million years ago or by convergence following independent origins over that same time period. Regardless, comparative analyses of diverse nodulation syndromes can provide insights into constraints on nodulation-what must be acquired or cannot be lost for a functional symbiosis-and the latitude for variation in the symbiosis. However, much remains to be learned about nodulation, especially outside of legumes. Here, we employed a large-scale phylogenomic analysis across 88 species, complemented by 151 RNA-seq libraries, to elucidate the evolution of RNS. Our phylogenomic analyses further emphasize the uniqueness of the transcription factor NIN as a master regulator of nodulation and identify key mutations that affect its function across the NFNC. Comparative transcriptomic assessment revealed nodule-specific upregulated genes across diverse nodulating plants, while also identifying nodule-specific and nitrogen-response genes. Approximately 70% of symbiosis-related genes are highly conserved in the four representative species, whereas defense-related and host-range restriction genes tend to be lineage specific. Our study also identified over 900 000 conserved non-coding elements (CNEs), over 300 000 of which are unique to sampled NFNC species. NFNC-specific CNEs are enriched with the active H3K9ac mark and are correlated with accessible chromatin regions, thus representing a pool of candidate regulatory elements for genes involved in RNS. Collectively, our results provide novel insights into the evolution of nodulation and lay a foundation for engineering of RNS traits in agriculturally important crops.

Phylogenomics of the genus Glycine sheds light on polyploid evolution and life-strategy transition

Polyploidy and life-strategy transitions between annuality and perenniality often occur in flowering plants. However, the evolutionary propensities of polyploids and the genetic bases of such transitions remain elusive. We assembled chromosome-level genomes of representative perennial species across the genus Glycine including five diploids and a young allopolyploid, and constructed a Glycine super-pangenome framework by integrating 26 annual soybean genomes. These perennial diploids exhibit greater genome stability and possess fewer centromere repeats than the annuals. Biased subgenomic fractionation occurred in the allopolyploid, primarily by accumulation of small deletions in gene clusters through illegitimate recombination, which was associated with pre-existing local subgenomic differentiation. Two genes annotated to modulate vegetative-reproductive phase transition and lateral shoot outgrowth were postulated as candidates underlying the perenniality-annuality transition. Our study provides insights into polyploid genome evolution and lays a foundation for unleashing genetic potential from the perennial gene pool for soybean improvement.

Using Genomic Location and Coalescent Simulation to Investigate Gene Tree Discordance in Medicago L

Several well-documented evolutionary processes are known to cause conflict between species-level phylogenies and gene-level phylogenies. Three of the most challenging processes for species tree inference are incomplete lineage sorting, hybridization and gene duplication, which may result in unwarranted comparisons of paralogous genes. Several existing methods have dealt with these processes but none has yet been able to untangle all three at once. Here, we propose a stepwise method by which these processes can be discerned using information on genomic location coupled with coalescent simulations. In the first step, highly discordant genes within genomic blocks (putative paralogs) are identified and excluded from the data set and, in the second step, blocks of linked genes are grouped according to their hybrid history. Existing multispecies coalescent software can then be applied to recover the principal tree(s) that make up the species tree/network without violating the underlying model. The potential of the approach is evaluated on simulated data derived from a species network composed of nine species, of which one is of hybrid origin, and displaying a single-gene duplication that leads to paralogous comparisons. We apply our method to an empirical set of 12 genes from 7 species sampled in the plant genus Medicago that display phylogenetic discordance. We identify the causes of the discordance and demonstrate that the Medicago orbicularis lineage experienced an episode of ancient hybridization. Our results show promise as a new way to explore phylogenetic sequence data that can significantly improve species tree inference in presence of hybridization and undetected paralogy or other causes leading to extremely discordant gene trees. [Coalescent simulation; gene tree; genomic location; hybridization; incomplete lineage sorting; paralogy; phylogenetic incongruence; principal tree; species tree.].

The legacy of diploid progenitors in allopolyploid gene expression patterns

Allopolyploidization (hybridization and whole-genome duplication) is a common phenomenon in plant evolution with immediate saltational effects on genome structure and gene expression. New technologies have allowed rapid progress over the past decade in our understanding of the consequences of allopolyploidy. A major question, raised by early pioneer of this field Leslie Gottlieb, concerned the extent to which gene expression differences among duplicate genes present in an allopolyploid are a legacy of expression differences that were already present in the progenitor diploid species. Addressing this question necessitates phylogenetically well-understood natural study systems, appropriate technology, availability of genomic resources and a suitable analytical framework, including a sufficiently detailed and generally accepted terminology. Here, we review these requirements and illustrate their application to a natural study system that Gottlieb worked on and recommended for this purpose: recent allopolyploids of Tragopogon (Asteraceae). We reanalyse recent data from this system within the conceptual framework of parental legacies on duplicate gene expression in allopolyploids. On a broader level, we highlight the intellectual connection between Gottlieb's phrasing of this issue and the more contemporary framework of cis- versus trans-regulation of duplicate gene expression in allopolyploid plants.

Genome sequence of mungbean and insights into evolution within Vigna species

Mungbean (Vigna radiata) is a fast-growing, warm-season legume crop that is primarily cultivated in developing countries of Asia. Here we construct a draft genome sequence of mungbean to facilitate genome research into the subgenus Ceratotropis, which includes several important dietary legumes in Asia, and to enable a better understanding of the evolution of leguminous species. Based on the de novo assembly of additional wild mungbean species, the divergence of what was eventually domesticated and the sampled wild mungbean species appears to have predated domestication. Moreover, the de novo assembly of a tetraploid Vigna species (V. reflexo-pilosa var. glabra) provides genomic evidence of a recent allopolyploid event. The species tree is constructed using de novo RNA-seq assemblies of 22 accessions of 18 Vigna species and protein sets of Glycine max. The present assembly of V. radiata var. radiata will facilitate genome research and accelerate molecular breeding of the subgenus Ceratotropis.

Transgressive physiological and transcriptomic responses to light stress in allopolyploid Glycine dolichocarpa (Leguminosae)

Allopolyploidy is often associated with increased photosynthetic capacity as well as enhanced stress tolerance. Excess light is a ubiquitous plant stress associated with photosynthetic light harvesting. We show that under chronic excess light, the capacity for non-photochemical quenching (NPQ(max)), a photoprotective mechanism, was higher in a recently formed natural allotetraploid (Glycine dolichocarpa, designated 'T2') than in its diploid progenitors (G. tomentella, 'D3'; and G. syndetika, 'D4'). This enhancement in NPQ(max) was due to an increase in energy-dependent quenching (qE) relative to D3, combined with an increase in zeaxanthin-dependent quenching (qZ) relative to D4. To explore the genetic basis for this phenotype, we profiled D3, D4 and T2 leaf transcriptomes and found that T2 overexpressed genes of the water-water cycle relative to both diploid progenitors, as well as genes involved in cyclic electron flow around photosystem I (CEF-PSI) and the xanthophyll cycle, relative to D4. Xanthophyll pigments have critical roles in NPQ, and the water-water cycle and CEF-PSI are non-photosynthetic electron transport pathways believed to facilitate NPQ formation. In the absence of CO(2), T2 also exhibited greater quantum yield of photosystem II than either diploid, indicating a greater capacity for non-photosynthetic electron transport. We postulate that, relative to its diploid progenitors, T2 is able to achieve higher NPQ(max) due to an increase in xanthophyll pigments coupled with enhanced electron flow through the water-water cycle and CEF-PSI.

Transgressive physiological and transcriptomic responses to light stress in allopolyploid Glycine dolichocarpa (Leguminosae)

Allopolyploidy is often associated with increased photosynthetic capacity as well as enhanced stress tolerance. Excess light is a ubiquitous plant stress associated with photosynthetic light harvesting. We show that under chronic excess light, the capacity for non-photochemical quenching (NPQ(max)), a photoprotective mechanism, was higher in a recently formed natural allotetraploid (Glycine dolichocarpa, designated 'T2') than in its diploid progenitors (G. tomentella, 'D3'; and G. syndetika, 'D4'). This enhancement in NPQ(max) was due to an increase in energy-dependent quenching (qE) relative to D3, combined with an increase in zeaxanthin-dependent quenching (qZ) relative to D4. To explore the genetic basis for this phenotype, we profiled D3, D4 and T2 leaf transcriptomes and found that T2 overexpressed genes of the water-water cycle relative to both diploid progenitors, as well as genes involved in cyclic electron flow around photosystem I (CEF-PSI) and the xanthophyll cycle, relative to D4. Xanthophyll pigments have critical roles in NPQ, and the water-water cycle and CEF-PSI are non-photosynthetic electron transport pathways believed to facilitate NPQ formation. In the absence of CO(2), T2 also exhibited greater quantum yield of photosystem II than either diploid, indicating a greater capacity for non-photosynthetic electron transport. We postulate that, relative to its diploid progenitors, T2 is able to achieve higher NPQ(max) due to an increase in xanthophyll pigments coupled with enhanced electron flow through the water-water cycle and CEF-PSI.

High alpha-1 antitrypsin clearance predicts severity of gut graft-versus-host disease (GVHD) in children

The clinical evaluation and management of gut GVHD is a significant challenge in pediatric HSCT. It is often difficult to obtain pathological evidence to confirm diagnosis and/or to determine response to treatment. The severity of the disease itself may not be related to just the classic symptom of diarrhea. The objectives of this study were to prospectively evaluate patients with suspected gut GVHD for PLE as measured by AATC in stools at two different times for each patient and to compare the severity of the PLE with the severity of clinical acute gut GVHD. Thirteen patients were suspected of gut GVHD by clinical criteria (diarrhea > 10 mL/kg/24 h); one patient was excluded for being unable to complete the stool collection. Therefore, 12 patients, 10 boys and two girls, were studied. Median stool volume was 27.5 mL/kg/day (range 10.1-109.0).The median age at BMT was 11.1 yr (range 3.9-17.0 yr). All patients had negative stool electron microscopy for viruses and cultures for C. difficile on their first collection. Nine patients (75%) had two 24-h stool collections performed at a median of eight days apart (range 7-14 days). At the time of the first collection, six patients had ≥ stage 2 acute gut GVHD, and at second collection, four patients had ≥ stage 2 gut GVHD and four collections were of non-diarrheal stool (hence treatment response). Median AATC from all 21 collections was 19.0 mL/day (range 3.0-561.0), and levels >22 mL/day indicate the diagnosis of PLE. The four children initially suspected of GVHD but who had a negative biopsy completed a total of five collections with a median AATC of 5.0 mL/day (range 3.0-16.0) vs. a median of 33.5 for the remainder of the collections (range 3-561). Stage of gut GVHD correlated with elevated AATC and with stool volume. AATC > 22 mL/day showed a sensitivity of 70% and specificity of 82% for significant gut GVHD (≥ stage 2). Seven stool collections were taken at ≥ stage 3 gut GVHD; six of those seven patients were positive for PLE. Larger stool volumes were more predictive, and five collections with stool volumes >30 mL/kg/day were positive for PLE. We conclude that a significant positive correlation exists between the severity of PLE and the stage of gut GVHD (p < 0.04), particularly obvious in patients with stages 2-4 GVHD (p = 0.03). Despite the small number of patients recruited, this study emphasizes the need to consider PLE as a useful aspect of the clinical picture. We suggest that in order to see a response to therapy and therefore a decrease in AATC, clinicians should wait at least 2 wk from the initiation of therapy before repeating AATC test. In light of the significant morbidity and mortality associated with ≥ stage 2 gut GVHD, and as an important therapeutic decision for these patients, one may consider evaluating AATC if a biopsy is not an option.

Inferring population structure and genetic diversity of broad range of wild diploid alfalfa (Medicago sativa L.) accessions using SSR markers

Diversity analyses in alfalfa have mainly evaluated genetic relationships of cultivated germplasm, with little known about variation in diploid germplasm in the M. sativa-falcata complex. A collection of 374 individual genotypes derived from 120 unimproved diploid accessions from the National Plant Germplasm System, including M. sativa subsp. caerulea, falcata, and hemicycla, were evaluated with 89 polymorphic SSR loci in order to estimate genetic diversity, infer the genetic bases of current morphology-based taxonomy, and determine population structure. Diploid alfalfa is highly variable. A model-based clustering analysis of the genomic data identified two clearly discrete subpopulations, corresponding to the morphologically defined subspecies falcata and caerulea, with evidence of the hybrid nature of the subspecies hemicycla based on genome composition. Two distinct subpopulations exist within each subsp. caerulea and subsp. falcata. The distinction of caerulea was based on geographical distribution. The two falcata groups were separated based on ecogeography. The results show that taxonomic relationships based on morphology are reflected in the genetic marker data with some exceptions, and that clear distinctions among subspecies are evident at the diploid level. This research provides a baseline from which to systematically evaluate variability in tetraploid alfalfa and serves as a starting point for exploring diploid alfalfa for genetic and breeding experiments.

Comparative outcome of hematopoietic stem cell transplantation for pediatric acute lymphoblastic leukemia following cyclophosphamide and total body irradiation or VP16 and total body irradiation conditioning regimens

To compare the outcome of hematopoietic stem cell transplantation (HSCT) in pediatric acute lymphoblastic leukemia (ALL) conditioned with two different regimens: (1) single dose of VP16 (60 mg/kg over 4 h) and total body irradiation (TBI; 1200 cGy, in six fractions) or (2) Cyclophosphamide 50 mg/kg over 1 h daily for 4 days followed by the same dose of TBI. One hundred and seven children with ALL received fully matched HSCT from 1990 to 2003 in the Hospital for Sick Children, Toronto. All received cyclosporin A and a short course of methotrexate for graft-versus-host disease (GVHD) prophylaxis. The VP16 group, there were 36 matched related donor transplants (MRD) and 26 matched unrelated donor transplants (MUD), and in the cyclophosphamide group there were 23 MRD and 22 MUD transplants. Neutrophil engraftment occurred at a median of 18 and 17 days for the VP16/TBI and the CY/TBI groups, respectively. The 3 year event-free survival and overall survival were 47 +/- 7 and 55 +/- 7% for those receiving VP16/TBI, and 51 +/- 8 and 53 +/- 8% for the CY/TBI group. There were no significant differences in the prevalence of acute or chronic GVHD and transplant-related mortality between the two groups. Both VP16/FTBI and CY/FTBI regimen are equally effective regimens.

Direct costs of glaucoma and severity of the disease: a multinational long term study of resource utilisation in Europe

BACKGROUND

Resource utilisation and direct costs associated with glaucoma progression in Europe are unknown. As population progressively ages, the economic impact of the disease will increase.

METHODS

From a total of 1655 consecutive cases, the records of 194 patients were selected and stratified by disease severity. Record selection was based on diagnoses of primary open angle glaucoma, glaucoma suspect, ocular hypertension, or normal tension glaucoma; 5 years minimum follow up were required. Glaucoma severity was assessed using a six stage glaucoma staging system based on static threshold visual field parameters. Resource utilisation data were abstracted from the charts and unit costs were applied to estimate direct costs to the payer. Resource utilisation and estimated direct cost of treatment, per person year, were calculated.

RESULTS

A statistically significant increasing linear trend (p = 0.018) in direct cost as disease severity worsened was demonstrated. The direct cost of treatment increased by an estimated 86 for each incremental step ranging from 455 euro per person year for stage 0 to 969 euro per person year for stage 4 disease. Medication costs ranged from 42% to 56% of total direct cost for all stages of disease.

CONCLUSIONS

These results demonstrate for the first time in Europe that resource utilisation and direct medical costs of glaucoma management increase with worsening disease severity. Based on these findings, managing glaucoma and effectively delaying disease progression would be expected to significantly reduce the economic burden of this disease. These data are relevant to general practitioners and healthcare administrators who have a direct influence on the distribution of resources.

Placing Paleopolyploidy in Relation to Taxon Divergence: A Phylogenetic Analysis in Legumes Using 39 Gene Families

Young polyploid events are easily diagnosed by various methods, but older polyploid events become increasingly difficult to identify as chromosomal rearrangements, tandem gene or partial chromosome duplications, changes in substitution rates among duplicated genes, pseudogenization or locus loss, and interlocus interactions complicate the means of inferring past genetic events. Genomic data have provided valuable information about the polyploid history of numerous species, but on their own fail to show whether related species, each with a polyploid past, share a particular polyploid event. A phylogenetic approach provides a powerful method to determine this but many processes may mislead investigators. These processes can affect individual gene trees, but most likely will not affect all genes, and almost certainly will not affect all genes in the same way. Thus, a multigene approach, which combines the large-scale aspect of genomics with the resolution of phylogenetics, has the power to overcome these difficulties and allow us to infer genomic events further into the past than would otherwise be possible. Previous work using synonymous distances among gene pairs within species has shown evidence for large-scale duplications in the legumes Glycine max and Medicago truncatula. We present a case study using 39 gene families, each with three or four members in G. max and the putative orthologues in M. truncatula, rooted using Arabidopsis thaliana. We tested whether the gene duplications in these legumes occurred separately in each lineage after their divergence (Hypothesis 1), or whether they share a round of gene duplications (Hypothesis 2). Many more gene family topologies supported Hypothesis 2 over Hypothesis 1 (11 and 2, respectively), even after synonymous distance analysis revealed that some topologies were providing misleading results. Only ca. 33% of genes examined support either hypothesis, which strongly suggests that single gene family approaches may be insufficient when studying ancient events with nuclear DNA. Our results suggest that G. max and M. truncatula, along with approximately 7000 other legume species from the same clade, share an ancient round of gene duplications, either due to polyploidy or to some other process.

Health-related quality of life (HRQL) scores reported from parents and their children with chronic illness differed depending on utility elicitation method

OBJECTIVE

To describe the relationship between health-related quality of life (HRQL) as measured by utility when elicited from parents and their children with chronic illness.

STUDY DESIGN AND SETTING

We enrolled families of children admitted for cancer chemotherapy and those attending outpatient rheumatology, hemophilia and bone marrow transplantation clinics. Children in grade 6 or higher were included. The child's HRQL was rated by parent and child using the Standard Gamble (SG), Visual Analogue Scale (VAS), Time Trade-Off (TTO), and Health Utilities Index Mark 2/3 (HUI2 and HUI3).

RESULTS

22 families were included. The mean parent SG was 0.92 +/- 0.09, which was similar to the mean SG elicited from their children of 0.92 +/- 0.10. The parent and child SG were moderately concordant (ICC=0.64, 95% CI=0.30, 0.83; P=.0005). In contrast, TTO scores were not concordant (ICC=0.14, 95% CI=-0.29, 0.53; P=.3), with parents (mean TTO=0.77 +/- 0.31) rating HRQL worse than children (mean TTO=0.92 +/- 0.11; P=.04). Similarly, the mean parent HUI2 of 0.82 +/- 0.22 was lower than the child HUI2 of 0.95 +/- 0.07; P=.02 and HUI2 were not concordant (ICC=0.11, 95% CI=-0.35, 0.53; P=.3) between parents and children.

CONCLUSION

Parents and children rate HRQL similarly according to SG, but parents rate HRQL significantly worse using TTO and HUI2.

Underlying chronic granulomatous disease in a patient with bronchocentric granulomatosis

We present a case of bronchocentric granulomatosis in a woman with no history of asthma who was colonised with Aspergillusfumigatus. A family history of chronic granulomatous disease prompted further testing that demonstrated severely depressed neutrophil oxidant production and gp91(phox) deficiency compatible with the X linked carrier state of chronic granulomatous disease. Only one report of the association of these two rare diseases has previously appeared in the literature. We postulate that an ineffective immune response led to the prolonged colonisation of Afumigatus resulting in a hypersensitivity reaction that was manifest clinically as bronchocentric granulomatosis.

Validity of a modified standard gamble elicited from parents of a hospital-based cohort of children

OBJECTIVES

To examine the validity of a modified standard gamble (Mod SG) (nondeath baseline) by comparing these scores to SG (death baseline), time trade off (TTO), visual analog scale (VAS), Health Utilities Index (HUI), and Child Health Questionnaire (CHQ).

METHODS

Respondents were parents of in-patients with cancer receiving chemotherapy and parents of children without cancer attending outpatient clinics. Construct validity was determined by comparing a priori hypotheses to actual correlations between measures. Discriminant validity was examined by anticipating that in-patients with cancer would have lower HRQL than outpatients.

RESULTS

85 families were included. Both Mod SG and SG were moderately correlated with TTO (r=0.50 and r=0.49; P<.01 for both). Both Mod SG and SG were moderately correlated with TTO (r=0.47 and r=0.05, P<0.002 for both).

CONCLUSION

The Mod SG did not perform better than SG. Two nonoverlapping groups of HRQL measures were demonstrated.

Life-threatening pulmonary hemorrhages post bone marrow transplantation in Hurler syndrome. Report of three cases and review of the literature

Hurler syndrome (MPS-IH) is an autosomal recessive mucopolysaccharide storage disorder caused by deficiency of lysosomal alpha-L-iduronidase (IDU) enzyme activity. This results in accumulation of heparan sulfate and dermatan sulfate substances. Untreated children develop progressive developmental deterioration and multisystem morbidity with a median survival of 5 years. Allogeneic bone marrow transplantation (BMT) is the only long-lasting treatment that ameliorates or halts the aggressive course of the disease. Pulmonary hemorrhage (PH) is an unusual complication of BMT and has not been previously reported in MPS-IH post-BMT. We report three children with MPS-IH with life-threatening PH around the time of engraftment. All needed intensive-care support and one child developed recurrent PH that required prolonged ventilation.

Low-intensity hematopoietic stem-cell transplantation across human leucocyte antigen barriers in dyskeratosis congenita

Since the results of conventional hematopoietic stem-cell transplantation (HSCT) for patients with dyskeratosis congenita (DC) are poor owing to the high incidence of transplant-related complications, we explored the use of a low-intensity HSCT regimen. We report two children with DC with severe cytopenia, who underwent successful HSCT from a matched unrelated donor after conditioning with fludarabine, cyclophosphamide, and antithymocyte globulin. Graft-versus-host-disease (GVHD) prophylaxis consisted of corticosteroids and cyclosporin A. The regimen was well tolerated, no significant transplant-related complications were observed, and engraftment was rapid and complete. At 15 and 16 months after HSCT, the children were fully engrafted, in excellent clinical condition, full-donor chimerism, and no signs of GVHD. We conclude that a low-intensity regimen is sufficient to induce durable engraftment using matched unrelated donor HSCT in DC patients, with minimal 1-year transplant-related toxicity. Longer follow-up will determine whether this regimen also reduces long-term toxicity.

Construct validation of the Health Utilities Index and the Child Health Questionnaire in children undergoing cancer chemotherapy

The objective of this study was to evaluate the construct validity of two questionnaire-based measures of health-related quality of life (HRQL) in children undergoing cancer chemotherapy: the Health Utilities Index (HUI) and the Child Health Questionnaire (CHQ). Subjects were children hospitalised for chemotherapy. To examine construct validity: (1). a priori expected relations between CHQ concepts and HUI attributes were examined; (2). HUI and CHQ summary scores were compared to visual analogue scale (VAS) scores. Ease of completion was rated using a 5-point categorical scale and completion time was recorded. A total of 36 subjects were included. The maximum score was seen in 15 (47%) of HUI3 assessments. As predicted, CHQ body pain was moderately correlated with HUI3 pain (r=0.51), CHQ physical functioning was moderately correlated with HUI2 mobility (r=0.58) and CHQ mental health was moderately correlated with HUI2 emotion (r=0.53). Only the CHQ psychosocial subscale (and not HUI) was correlated with VAS (r=0.44). The CHQ and the HUI were both easy to use. The HUI questionnaires required less time to complete (mean=3.1, s.d.=1 min) compared with CHQ (mean=13.1, s.d.=3.4 min, P<0.0001). In conclusion, HUI and CHQ demonstrated construct validity in children undergoing cancer chemotherapy. The Health Utilities Index is subject to a ceiling effect whereas CHQ requires more time to complete.

A cost-effectiveness evaluation of amlodipine usage in patients with coronary artery disease in Sweden

The objective of this analysis was to calculate the cost-effectiveness of amlodipine therapy in patients with coronary artery disease in Sweden. It is hypothesised that treatment with amlodipine will have an impact on overall cardiovascular disease treatment costs, resulting in a positive cost-effectiveness profile. A Markov cohort simulation model was constructed to simulate event-related and procedure-related health economic outcomes of coronary artery disease populations on amlodipine versus those on placebo. Patient level data from the Prospective Evaluation of the Vascular Effects of Norvasc Trial was used to populate the model. The total number of adverse cardiovascular clinical outcomes experienced over a three-year period was lower for patient on amlodipine than for those on placebo. The rate of hospitalisation per patient due to angina, coronary artery bypass graft, percutaneous transluminal coronary angioplasty, congestive heart failure, and myocardial infarction in the placebo cohort was 64.7%, while the rate in the amlodipine cohort was 46.9%. The cost per patient was Swedish kroner (SEK)26,600 for amlodipine patients and SEK27,400 for placebo patients. The use of amlodipine resulted in improved clinical outcomes as well as a slight savings in cost over a three-year period.

Single-centre experience with allogeneic bone marrow transplantation for acute lymphoblastic leukaemia in childhood: similar survival after matched-related and matched-unrelated donor transplants

Seventy percent of children with acute lymphoblastic leukaemia (ALL) who may benefit from bone marrow transplant (BMT) lack a human leucocyte antigen (HLA)-matched related donor (MRD). For these children, BMT from a matched unrelated donor (MUD) represents a therapeutic option. We reviewed the course of 62 children with ALL who received fully matched marrow allografts at our institution between 1990 and 1998: 36 with MRDs and 26 with MUDs. Clinical characteristics were similar in the two groups. The interval from attainment of pre-BMT complete remission to transplant was significantly longer in the MUD group. Conditioning (etoposide/total body irradiation) and graft-versus-host disease (GVHD) prophylaxis regimens were the same for all patients, and all received T cell-replete bone marrow. There was no significant difference in probability of engraftment, or time to engraftment, in the two groups. MUD BMT recipients had a significantly greater incidence of grade II-IV acute GVHD (58% versus 24% in the MRD group; P = 0.02), and demonstrated a trend towards more chronic GVHD (39% versus 15%; P = 0.06). Three years post BMT, the probabilities of transplant-related mortality were 33 +/- 11% and 20 +/- 8% in MUD and MRD groups respectively (P = 0.38); the probabilities of relapse were 28 +/- 12% and 41 +/- 9% respectively (P = 0.19). Lansky or Karnofsky performance scores in event-free survivors were 90-100 in 87% of the MUD group and 83% of the MRD group. With a median follow up of 38 months (range, 3-97), 3-year event-free survival was 49 +/- 11% and 47 +/- 9% in the MUD and MRD BMT groups respectively (P = 0.71). These results suggest that MUD BMT is a valuable therapy for children with ALL in whom BMT is indicated, and underscore the importance of efforts aimed at expediting unrelated donor searches for patients lacking a MRD.

Initial bone marrow aspiration in childhood idiopathic thrombocytopenia: decision analysis

PURPOSE

Bone marrow aspiration (BMA) is routinely performed before starting steroid therapy in children with idiopathic thrombocytopenia, primarily to rule out leukemia.

METHODS

A decision tree for the initial management of a child older than age 6 months, presenting with idiopathic thrombocytopenia, without blasts on the peripheral smear was constructed. The three strategies are: 1) initial BMA in all patients; 2) initial BMA only in patients at high risk; and 3) empiric therapy for all patients without initial BMA. High-risk criteria include any of: platelet count >50 x 10(9)/L; hemoglobin <100 g/L (age younger than 12 months) or <110 g/L (age older than 12 months): white blood cell count <5 x 10(9)/L (younger than 6 years) or <4 x 10(9)/L (older than 6 years); or absolute neutrophil count <1.5 x 10(9)/L (younger than 6 years) or <2 x 10(9)/L (older than 6 years). The results are expressed as quality-adjusted life years (QALYs), a measure that estimates the overall life expectancy in years for patients receiving a particular treatment strategy, corrected for the patient's quality of life.

RESULTS

The base case results are: 1) BMA all = 69.649 QALYs; 2) high-risk BMA = 69.652 QALYs; and 3) empiric therapy = 69.644 QALYs. These results indicate a three-way toss-up because there is less than a 4-day quality-adjusted difference (0.01) between strategies.

CONCLUSION

This study indicates that the initial BMA does not significantly change the overall QALYs of a child presenting with thrombocytopenia and, consequently, is not mandatory in every patient before starting steroids.

Patient satisfaction with oral versus nonoral therapeutic approaches in onychomycosis

The follow-up results of a 9-month observational study of 150 onychomycosis patients treated with a variety of mechanical, topical, and oral therapies by podiatric physicians and dermatologists are presented. Changes from baseline in toenail condition and patient satisfaction were assessed at 4- and 9-month follow-up. At 9 months, patients who had received oral therapy reported significantly fewer onychomycosis-related problems in social situations, including embarrassment or self-consciousness about the appearance of nails, avoidance of contact by others, being perceived as unclean or untidy, and the desire to keep their nails concealed. Patient-reported satisfaction with the treatment program was significantly higher for those receiving oral therapy than for those receiving nonoral therapy.

Economic and quality-of-life impact of rheumatoid arthritis

Although RA is a disabling disease with increased mortality and an unknown cure, early treatment with DMARD therapy improves patient outcomes. The economic and humanistic effects of this disease are substantial, with patients becoming increasingly disabled from RA. It is extremely encouraging to the rheumatology community that leflunomide provides significant and sustained improvements in clinical signs and symptoms, and offers practicing physicians an additional option in the treatment of RA. It improves and maintains physical function and HRQoL. Leflunomide's effects were consistent across three studies over two years of treatment. It has been demonstrated to improve physical function as measured by the HAQ DI, and HRQoL as indicated by the SF-36 data, two instruments held up as the gold standard for the assessment of patient outcomes in RA clinical trials.

Phylogenetic utility of the nuclear gene malate synthase in the palm family (Arecaceae)

There is currently a shortage of DNA regions known to be useful for phylogenetic research in palms (Arecaceae). We report the development and use of primers for amplifying and sequencing regions of the nuclear gene malate synthase. In palms the gene appears to be single-copy, with exon regions that are phylogenetically informative within the family. We constructed a phylogeny of 45 palms and five outgroup taxa using 428 bp of malate synthase exon regions. We found that some major clades within the family were recovered, but there was a lack of resolution among the genera in subfamilies Arecoideae, Ceroxyloideae, Coryphoideae, and Phytelephantoideae. In a second analysis, malate synthase exon regions totaling 1002 bp were sequenced for 16 palms and two outgroup taxa. There was increased bootstrap support for some groups and for the placement of the monotypic genus Nypa as sister to the rest of the family. A comparison with data sets from noncoding regions of the chloroplast genome indicates that malate synthase sequences are more variable and potentially contain more phylogenetic information. We found no evidence of multiple copies of the malate synthase gene in palm genomes.

Prevalence of pulmonary disorders in patients with newly diagnosed rheumatoid arthritis

Our objective was to determine the prevalence of airway hyperreactivity (AHR) in patients with newly diagnosed rheumatoid arthritis (RA) who had received no disease-modifying antirheumatic drugs (DMARDs) and to characterise the spectrum of lung diseases identifiable in these patients at the time of presentation. Eighteen consecutive patients with newly diagnosed RA referred to our medical centre's rheumatology clinic over 2 years underwent pulmonary evaluation with arterial blood gas analysis, chest radiographs, spirometry before and after bronchodilator medication, and body plethysmography. They returned on subsequent days in random order for methacholine inhalation challenge (MIC) and eucapnic voluntary hyperventilation (EVH) as bronchoprovocation techniques. One patient had severe obstructive disease at presentation and therefore did not undergo bronchoprovocation. We found a wide variety of pulmonary abnormalities, including two patients with hypoxia (12%), two with obstruction (12%), three with restriction (18%) and four with AHR (23%). The data also suggest a strong association between pulmonary diseases in RA and cigarette smoking. Although no single characteristic lung disease such as AHR was identified in patients presenting with RA, the association between lung disease and cigarette smoking is striking and underscores the need to emphasise smoking cessation in this patient population.

Phylogeny of the Celastraceae inferred from phytochrome B gene sequence and morphology

Phylogenetic relationships within Celastraceae were inferred using a simultaneous analysis of 61 morphological characters and 1123 base pairs of phytochrome B exon 1 from the nuclear genome. No gaps were inferred, and the gene tree topology suggests that the primers were specific to a single locus that did not duplicate among the lineages sampled. This region of phytochrome B was most useful for examining relationships among closely related genera. Fifty-one species from 38 genera of Celastraceae were sampled. The Celastraceae sensu lato (including Hippocrateaceae) were resolved as a monophyletic group. Loesener's subfamilies and tribes of Celastraceae were not supported. The Hippocrateaceae were resolved as a monophyletic group nested within a paraphyletic Celastraceae sensu stricto. Goupia was resolved as more closely related to Euphorbiaceae, Corynocarpaceae, and Linaceae than to Celastraceae. Plagiopteron (Flacourtiaceae) was resolved as the sister group of Hippocrateoideae. Brexia (Brexiaceae) was resolved as closely related to Elaeodendron and Pleurostylia. Canotia was resolved as the sister group of Acanthothamnus within Celastraceae. Perrottetia and Mortonia were resolved as the sister group of the rest of the Celastraceae. Siphonodon was resolved as a derived member of Celastraceae. Maytenus was resolved as three disparate groups, suggesting that this large genus needs to be recircumscribed.

A multinational pharmacoeconomic evaluation of acute major depressive disorder (MDD): a comparison of cost-effectiveness between venlafaxine, SSRIs and TCAs

METHODS

We conducted a multinational pharmacoeconomic evaluation comparing the immediate release form of a new class of serotonin norepinephrine reuptake inhibitor (SNRI), venlafaxine IR to the selective serotonin reuptake inhibitors (SSRIs) and the tricyclic antidepressants (TCAs) in the treatment of acute major depressive disorder (MDD) in 10 countries (Germany, Italy, Netherlands, Poland, Spain, Sweden, Switzerland, United Kingdom, United States, and Venezuela). We designed a decision analytic model assessing the acute phase of MDD treatment within a 6-month time horizon. Six decision tree models were customized with country-specific estimates from a clinical management analysis, meta-analytic rates from two published meta-analyses, and a resource valuation of treatment costs representing the inpatient and outpatient settings within each country. The meta-analyses provided the clinical rates of success defined as a 50% reduction in depression scores on the Hamilton Depression Scale (HAM-D) or the Montgomery-Asberg Depression Rating Scale (MADRS). Treatment regimen costs were determined from standard lists, fee schedules, and communication with local health economists in each country. The meta-analytic rates were applied to the decision analytic model to calculate the expected cost and expected outcomes for each antidepressant comparator. Cost-effectiveness was determined using the expected values for both a successful outcome, and a composite measure of outcome termed symptom-free days. A policy analysis was conducted to examine the health system budget impact in each country of increasing the utilization of the most effective antidepressant found in our study.

RESULTS

Initiating treatment of MDD with venlafaxine IR yielded a lower expected cost compared to the SSRIs and TCAs in all countries except Poland in the inpatient setting, and Italy and Poland within the outpatient settings. The weighted average expected cost per patient varied from US$632 (Poland) to US$5647 (US) in the six-month acute phase treatment of MDD. The estimated total budgetary impact for each 1% of venlafaxine utilization, assuming a population of one million MDD patients, ranged from US$1600 (Italy) to US$29,049 (US).

CONCLUSIONS

Within the inpatient and outpatient treatment settings, venlafaxine IR was a more cost-effective treatment of MDD compared to the SSRIs and TCAs. Additionally, the results of this investigation indicate that increased utilization of venlafaxine in most settings across Europe and the Americas will have favorable impact on health care payer budgets. ADR, adverse drug reaction; CMA, clinical management analysis; ECT, electroconvulsive therapy; HAM-D, Hamilton Depression Scale; MADRS, Montgomery-Asberg depression rating scale; MDD, major depressive disorder; SFD, symptom-free day; SNRI, serotonin-norepinephrine reuptake inhibitor; SSRI, selective serotonin reuptake inhibitor; TCA, tricyclic antidepressant; WHO, world health organization.

Amyotrophic lateral sclerosis with multiple sclerosis: a clinical and pathological report

We report a 62-year-old woman with a past history of painful central visual loss who developed progressive quadriparesis and bulbar palsy. Neurological examination revealed widespread upper and lower motor neuron signs in the bulbar region and extremities. Electromyography demonstrated widespread active and chronic motor axon loss. Magnetic resonance neuroimaging studies revealed enhancing callosal and periventricular white matter lesions and cervical and thoracic cord hyperintensities. Cerebrospinal fluid analysis was consistent with multiple sclerosis. The patient died of respiratory failure two years after presentation, and autopsy revealed multifocal demyelination involving the corpus callosum, cerebellum and spinal cord as well as pathologic findings typical of amyotrophic lateral sclerosis. A review of the literature confirms the exceedingly unusual combination of amyotrophic lateral sclerosis with multiple sclerosis.

Randomized placebo-controlled trial of oral antibiotics in pediatric oncology patients at low-risk with fever and neutropenia

PURPOSE

Fever combined with neutropenia in pediatric oncology patients has traditionally been managed in the hospital with broad-spectrum intravenous antibiotics until there is documented neutrophil recovery. Recent evidence has suggested that patients at "low-risk" can be discharged from the hospital before neutrophil recovery. Whether oral antibiotics are required at the time of discharge is not known.

PATIENTS AND METHODS

Using a randomized, double-blind, placebo-controlled study design, 73 patients at low-risk with episodes of fever and neutropenia were discharged home while still neutropenic: 37 administered with oral cloxacillin and cefixime and 36 administered with corresponding placebos. Low-risk criteria included: afebrile for more than 24 hours, negative blood culture results at 48 hours, absence of clinical sepsis, cancer in bone marrow remission, and absence of comorbid conditions.

RESULTS

Five patients (14%; 95% confidence interval [CI]; 2%-25%) in the antibiotic arm and two patients (6%; 95% CI; 0%-13%) in the placebo arm were readmitted to the hospital with recurrent fever while still neutropenic (P = 0.43). One patient randomized to the placebo arm had a positive blood culture result on readmission, which responded to appropriate intravenous antibiotics. All of the readmissions were uneventful and there were no fatalities. The average cost per episode of fever and neutropenia was $1,821 Canadian dollars with only minimal incremental cost to the antibiotic arm.

CONCLUSION

This study supports the discontinuation of antibiotics in pediatric oncology patients at low-risk who still have neutropenia at the time of discharge from the hospital.

"Low-risk" prediction rule for pediatric oncology patients presenting with fever and neutropenia

PURPOSE

To prospectively derive and validate a clinical prediction rule to allow a more tailored approach to the management of pediatric oncology outpatients presenting with fever and neutropenia.

PATIENTS AND METHODS

The clinical prediction rule was derived over a 1-year period and then validated over the following 8 months in a new set of fever and neutropenia episodes. Patients were excluded if they presented with comorbidity or an abnormal chest x-ray (CXR).

RESULTS

Significant bacterial infection (SBI; defined as any blood or urine culture positive for bacteria, interstitial or lobar consolidation on CXR, or unexpected death from infection) was documented in 43 of the 227 episodes. Multivariate analysis found four significant factors: bone marrow disease, general appearance unwell on initial examination, monocyte count less than 0.1 x 10(9)/L, and peak oral or oral equivalent temperature greater than 39 degrees C. Only the monocyte count contributed to determining a low-risk group, excluding SBI with 84% sensitivity (95% confidence interval [CI], 61% to 100%), 42% specificity (95% CI, 38% to 46%), and a negative predictive value of 92% (95% CI, 76% to 100%). If the monocyte count was >/= 0.1 x 10(9)/L at the time of presentation (low risk), the incidences of SBI and bacteremia were 8% and 5%, respectively, versus 25% and 17% in the high-risk group. When validated in a new population of 136 episodes of fever and neutropenia, the incidences of SBI and bacteremia in the low-risk group were 12% and 5%, respectively, and 25% and 19% in the high-risk group.

CONCLUSION

Pediatric oncology outpatients with fever and neutropenia who present with an initial monocyte count of >/= 0.1 x 10(9)/L and do not have comorbidity or an abnormal CXR at the time of presentation are at lower risk for SBI and can be considered for less aggressive initial therapy.

A pharmacoeconomic evaluation of two new products for the treatment of overactive bladder

The objective of this study is to evaluate the cost effectiveness of two new treatments for overactive bladder: once-daily controlled-release oxybutynin, and twice-daily tolterodine, with a comparison with oxybutynin immediate release. Also estimated are the potential cost savings to a health plan budget resulting from increased utilization of the most cost-effective treatment. The design is a decision-tree model based on clinical trial data and expert panel estimates with a six-month time horizon conducted from a payer perspective. The primary outcome measure used in the analysis was treatment success, with success defined as zero incontinence episodes per week. A secondary outcome measure was the expected number of continent days. As first-line therapy, controlled-release oxybutynin is the most cost-effective treatment as measured by expected cost per success and expected cost per continent days. Controlled-release, once-daily oxybutynin yielded the highest expected success rate and the highest number of expected continent days. The expected cost of treatment with controlled-release oxybutynin was lower than tolterodine and equivalent to immediate-release oxybutynin. Increased utilization of controlled-release oxybutynin results in an estimated saving of $0.007 to $0.026 per member per month for a hypothetical HMO. The model was robust, incorporating all assumptions based on univariate and multivariate sensitivity analysis. Initiating treatment with controlled-release oxybutynin is the most cost-effective approach to treatment for overactive bladder.

Evolution of genes and taxa: a primer

The rapidly growing fields of molecular evolution and systematics have much to offer to molecular biology, but like any field have their own repertoire of terms and concepts. Homology, for example, is a central theme in evolutionary biology whose definition is complex and often controversial. Homology extends to multigene families, where the distinction between orthology and paralogy is key. Nucleotide sequence alignment is also a homology issue, and is a key stage in any evolutionary analysis of sequence data. Models based on our understanding of the processes of nucleotide substitution are used both in the estimation of the number of evolutionary changes between aligned sequences and in phylogeny reconstruction from sequence data. The three common methods of phylogeny reconstruction--parsimony, distance and maximum likelihood--differ in their use of these models. All three face similar problems in finding optimal--and reliable--solutions among the vast number of possible trees. Moreover, even optimal trees for a given gene may not reflect the relationships of the organisms from which the gene was sampled. Knowledge of how genes evolve and at what rate is critical for understanding gene function across species or within gene families. The Neutral Theory of Molecular Evolution serves as the null model of molecular evolution and plays a central role in data analysis. Three areas in which the Neutral Theory plays a vital role are: interpreting ratios of nonsynonymous to synonymous nucleotide substitutions, assessing the reliability of molecular clocks, and providing a foundation for molecular population genetics.

Intracellular gene transfer in action: dual transcription and multiple silencings of nuclear and mitochondrial cox2 genes in legumes

The respiratory gene cox2, normally present in the mitochondrion, was previously shown to have been functionally transferred to the nucleus during flowering plant evolution, possibly during the diversification of legumes. To search for novel intermediate stages in the process of intracellular gene transfer and to assess the evolutionary timing and frequency of cox2 transfer, activation, and inactivation, we examined nuclear and mitochondrial (mt) cox2 presence and expression in over 25 legume genera and mt cox2 presence in 392 genera. Transfer and activation of cox2 appear to have occurred during recent legume evolution, more recently than previously inferred. Many intermediate stages of the gene transfer process are represented by cox2 genes in the studied legumes. Nine legumes contain intact copies of both nuclear and mt cox2, although transcripts could not be detected for some of these genes. Both cox2 genes are transcribed in seven legumes that are phylogenetically interspersed with species displaying only nuclear or mt cox2 expression. Inactivation of cox2 in each genome has taken place multiple times and in a variety of ways, including loss of detectable transcripts or transcript editing and partial to complete gene loss. Phylogenetic evidence shows about the same number (3-5) of separate inactivations of nuclear and mt cox2, suggesting that there is no selective advantage for a mt vs. nuclear location of cox2 in plants. The current distribution of cox2 presence and expression between the nucleus and mitochondrion in the studied legumes is probably the result of chance mutations silencing either cox2 gene.

Potential phylogenetic utility of the low-copy nuclear gene pistillata in dicotyledonous plants: comparison to nrDNA ITS and trnL intron in Sphaerocardamum and other Brassicaceae

We report the potential phylogenetic utility of DNA sequence data from the last 700 bp of a ca. 1-kb intron of the MADS-box gene pistillata from a sampling of Sphaerocardamum species and other Brassicaceae. These results are compared with nrDNA ITS and the chloroplast trnL intron for the same taxa to demonstrate the potential phylogenetic utility of this pistillata intron and to identify potential historically independent sequences for an ongoing study of relationships within Sphaerocardamum. Analyses of the DNA sequence data for Brassicaceae indicated that pairwise divergences and potentially informative characters were higher in the pistillata intron (0.6-30.8%, 284 characters) and ITS (0-24%, 94 characters) than in the chloroplast trnL intron (0-4.2%, 17 characters). A comparison of Sphaerocardamum sequences identified low divergences and numbers of informative characters for trnL intron (0-2.4%, 1 character) and nrDNA ITS (0-2.5%, 2 characters) and substantially more variation among the pistillata sequences (0.15-3.7%, 19 characters). Phylogenetic analyses of these pistillata sequences fully resolve ingroup relationships without character conflict. Results of pistillata PCR amplifications from a broader dicot sample showed that some primers may be useful in amplifying orthologous pistillata sequences. Ultimately this pistillata intron may be a valuable source of phylogenetic characters at lower taxonomic levels.

Origins, colonization, and lineage recombination in a widespread perennial soybean polyploid complex

Polyploidy is a dominant feature of flowering plant genomes, including those of many important crop species, implying that polyploidy confers evolutionary advantages on plant species. Recent molecular studies suggest that polyploids often originate many times from the same progenitor diploids. For this to provide a broader genetic base for a polyploid species, there must be lineage recombination in the genomes of polyploids having different origins, and this has rarely been documented in recently formed wild polyploid species. Glycine tabacina, a wild relative of soybean, forms a widespread polyploid complex in Australia and the islands of the Pacific Ocean. In a sample of 40 G. tabacina plants, DNA sequence variation at one homoeologous histone H3-D locus identified three alleles, each also found in Australian diploid Glycine species. These data agree with our previous studies of chloroplast DNA variation in suggesting that this polyploid has originated several times. Both the origins of the polyploid and several independent dispersals from Australia to oceanic islands appear to have occurred within the last 30,000 years. The distributions of histone alleles, chloroplast haplotypes, and alleles at two isozyme loci were uncorrelated, and 20 multilocus genotypes were found among the 40 plants sampled. Extensive lineage recombination is thus hypothesized in the polyploid, involving migration and occasional outcrossing in this predominantly inbreeding species. The combination of multiple origins with gene exchange among lineages increases the genetic base of a polyploid and may help explain the wide colonization of polyploid G. tabacina relative to its diploid progenitors.

Phylogeny, biogeography, and processes of molecular differentiation in Quercus subgenus Quercus (Fagaceae)

Quercus is one of the most abundant and economically important genera of woody plants in the Northern Hemisphere. To infer phylogenetic relationships within Quercus subgenus Quercus, chloroplast DNA (cpDNA) restriction sites and nucleotide sequences of the internal transcribed spacers (ITS) and the 5.8S coding region of the nuclear ribosomal DNA repeat were obtained for 44 individuals, including 25 species, intraspecific samples, and three outgroups. Separate parsimony analyses of each data set showed that individual gene trees were congruent and often complementary in supporting clades that generally corresponded to previously recognized taxonomic groups. Only one instance of strongly supported gene tree incongruence was detected and this anomalous pattern was explained best by ancient introgression of cpDNA across sectional boundaries. Simultaneous parsimony analysis of the pruned data sets supported the recognition of the strictly Eurasian section Cerris and resolved a novel hypothesis for the major infrageneric groups (Cerris- (Lobatae- (Protobalanus + Quercus sensu stricto))). The biogeographic hypothesis that all major oak lineages evolved locally at middle latitudes within the general distribution of their fossil ancestors was fully supported. This set of relationships also suggested a New World origin for the widespread white oaks of the Northern Hemisphere (section Quercus s. s.). For both data sets, inter- and intraspecific sampling within section Protobalanus showed little correspondence to morphological species. Greater cladistic structure among the samples was obtained by cpDNA restriction sites and two well-delimited plastomes types comprising a total of 15 distinct haplotypes were resolved. Haplotypes of 2 of the peripheral species in this species complex occupy terminal portions of one of the plastome clades, suggesting a more recent origin relative to those of more widespread species. The phylogeography of the two divergent plastome types suggested a north-south pattern, consistent with a Late Tertiary disjunction in the ancestral distribution of section Protobalanus.

Chloroplast-expressed glutamine synthetase (ncpGS): potential utility for phylogenetic studies with an example from Oxalis (Oxalidaceae)

Chloroplast-expressed glutamine synthetase (ncpGS), a nuclear-encoded gene containing several introns, is introduced as a tool for phylogenetic studies at lower taxonomic levels. This gene is a member of a multigene family, but it diverged long ago from the cytosolic-expressed members of the family and appears to be single copy in the majority of taxa examined to date. The conservation of both coding sequence and position of introns has allowed the design of primers for use in a broad range of dicot taxa to amplify and sequence a region of ncpGS that contains four introns. The utility of this region in phylogenetic studies of congeneric species is illustrated by an example using eight Oxalis species. The four introns in these taxa are typical in size (76 to 136 bp), base composition (high T content), and structure (e.g., sequence of splice sites and putative branch points) for plant internal introns. Levels of variation among these ncpGS sequences compare favorably with those of the internal transcribed spacer of nuclear ribosomal DNA (ITS) from the same taxa, and results of phylogenetic analysis of ncpGS data are generally congruent with previous results using ITS.

A pharmacoeconomic evaluation of major depressive disorder (Italy)

OBJECTIVE

To determine the most cost-effective oral therapy for the treatment of Major Depressive Disorder (MDD) in Italy.

METHOD

We conducted a pharmacoeconomic evaluation based on a decision analytic model that examined the treatment of major depressive disorder (MDD) in Italy. The analysis compared the serotonin norepinephrine reuptake inhibitor (SNRI), venlafaxine extended-release (venlafaxine XR), to selective serotonin reuptake inhibitors (SSRIs) and tricyclic antidepressants (TCAs). A meta-analysis was performed to determine the clinical rates of success. The meta-analytic rates were applied to the decision analytic model to calculate the expected cost and expected outcomes for each anti-depressant comparator. Cost-effectiveness was determined using the expected values for both a successful outcome, and a composite measure of outcome termed 'symptom-free days'. A policy analysis was conducted to estimate the financial impact to the Servizio Sanitario Nazionale (SSN).

RESULTS

Treatment of MDD with venlafaxine XR yielded the highest overall efficacy rates for outpatients (73.7%) versus SSRIs (61.4%) and TCAs (59.3%), and inpatients (62.3%) versus SSRIs (58.6%) and TCAs (58.2%). Venlafaxine XR had the lowest dropout rates due to lack of efficacy (4.8%) versus SSRIs (8.4%) and TCAs (6.8%), and adverse drug reactions (10.9%) versus SSRIs (17.4%) and TCAs (23.1%). Initiating treatment of MDD with venlafaxine XR yielded the lowest expected cost for outpatients and for inpatients. The total resulting savings for the SSN at a 5% venlafaxine XR utilization was estimated between L 963 million and L 3,210 million.

CONCLUSION

This study confirms that venlafaxine XR is generally a cost-effective treatment of MDD. Additionally, the results of this investigation suggest that increased utilization of venlafaxine XR will favorably impact the SSN.

Incongruence in the diploid B-genome species complex of Glycine (Leguminosae) revisited: histone H3-D alleles versus chloroplast haplotypes

Variation at the single-copy nuclear locus histone H3-D was surveyed in the diploid B-genome group of Glycine subgenus Glycine (Leguminosae: Papilionoideae), which comprises three named Australian species and a number of distinct but as yet not formally recognized taxa. A total of 23 alleles was identified in the 44 accessions surveyed. Only one individual was clearly heterozygous, which is not surprising given the largely autogamous breeding system of subgenus Glycine. Alleles differed by as many as 19 nucleotide substitutions, nearly all in the three introns; length variation was minimal. Phylogenetic analysis identified two shortest allele trees with very little homoplasy, suggesting that recombination has been rare. Both topological and data set incongruence were statistically significant between histone H3-D allele trees and trees inferred from chloroplast DNA haplotypes previously described from these same accessions. Whereas the distribution of H3-D alleles agrees well with morphologically based taxonomic groupings, chloroplast DNA haplotype polymorphisms transgress species boundaries, suggesting that the chloroplast genome is not tracking taxic relationships. Divergences among chloroplast DNA haplotypes involved in such transgressive patterns appear to be more recent than speciation events, suggesting hybridization rather than lineage sorting.