Randomized, controlled trial of telcagepant for the acute treatment of migraine

BACKGROUND

The neuropeptide calcitonin gene-related peptide (CGRP) plays a key role in migraine pathophysiology. In this large phase 3 clinical trial, we sought to confirm the efficacy of telcagepant, the first orally bioavailable CGRP receptor antagonist.

METHODS

Adults with migraine with or without aura (International Headache Society criteria) treated a moderate or severe attack with oral telcagepant 50 mg (n = 177), 150 mg (n = 381), 300 mg (n = 371), or placebo (n = 365) in a randomized, double-blind trial. The 5 co-primary endpoints were pain freedom, pain relief, and absence of photophobia, absence of phonophobia, and absence of nausea, all at 2 hours postdose. The key secondary endpoint was 2-24 hour sustained pain freedom. The prespecified primary efficacy analyses evaluated the 150 mg and 300 mg groups; the 50-mg group was included on an exploratory basis to further characterize the dose response but was not prespecified for analysis. Tolerability was assessed by adverse experience reports.

RESULTS

Telcagepant 300 mg was more effective (p <or= 0.001) than placebo on all primary endpoints and the key secondary endpoint, as was telcagepant 150 mg (p <or= 0.05). Telcagepant 300 mg showed a slight numeric advantage over telcagepant 150 mg on most measures. Telcagepant 50 mg values were numerically intermediate between placebo and telcagepant 150 mg and 300 mg. The percentages of patients with adverse experiences were 32.2% for telcagepant 50 mg, 32.0% for telcagepant 150 mg, 36.2% for telcagepant 300 mg, and 32.2% for placebo.

CONCLUSIONS

This study confirmed previous findings that telcagepant 300 mg was effective at relieving pain and other migraine symptoms at 2 hours and providing sustained pain freedom up to 24 hours. In this study, telcagepant 150 mg was also effective. Telcagepant was generally well tolerated.

Radiofrequency ablation of small renal cortical tumours in healthy adults: renal function preservation and intermediate oncological outcome

OBJECTIVES

To present the glomerular filtration rate (GFR) and oncological outcomes in a series of patients with cT1a renal cortical tumours treated with radiofrequency ablation (RFA), a non-ischaemic minimally invasive ablative method, as nephron-sparing surgery gives excellent oncological outcomes and preserves renal function.

PATIENTS AND METHODS

Healthy (American Society of Anesthesiologists, ASA, I and II) patients with cT1a renal masses were identified, and clinical and radiographic data were reviewed to assess indications, complications, radiological evidence of disease recurrence, and renal function. Changes in GFR were calculated. Radiological recurrence was defined as any new enhancement (>10 Hounsfield units) after absence of enhancement on initial 6-week computed tomography.

RESULTS

Four patients were ASA I and 59 were ASA II; the median (range) age was 58 (20-84.6) years and the lesion diameter 2.1 (1-4.0) cm. Preoperative needle biopsy was diagnostic in 89% of patients, including 75% diagnostic of renal cell carcinoma (RCC). At a median (range) follow-up of 34 (1.0-80) months the renal preservation rate was 97%. One patient had a nephrectomy for biopsy-confirmed recurrence of RCC at 55 months; a second had a nephrectomy at 24 months for suspected radiographic recurrence, but had no evidence of disease on final pathology. A fifth (20%) of the patients had chronic kidney disease at the time of diagnosis. The median GFR before and after RFA was 76.3 and 74.3 mL/min/m(2) (difference 2.0 mL/min/m(2)).

CONCLUSION

RFA might be a reasonable treatment choice for the healthy patient, with appropriate informed consent. Intermediate results suggest excellent oncological outcomes and preservation of renal function.

[Study of dental attrition in a medieval adult population from Southwest France]

INTRODUCTION

The aim of the authors was to study dental attrition in a medieval sample of paired mandibles and maxillas from the Southwest France (IX to XV century).

MATERIALS AND METHODS

We selected 58 adult individuals with maxillas and mandibles in good state of conservation, 29 women and 29 men from the medieval collection of Vilarnau-d'Amont (Western Pyrenees, France). Attrition was graded according to the Brabant index.

RESULTS

We found a high prevalence of attrition in this sample. The first molars (M1) were the maxillary and mandibular teeth most concerned by attrition. The most frequent attrition level was level 2, with dentin exposure. We did not find any significant difference of tooth wear between maxillary and mandibular teeth, even if maxillary teeth seemed to be more worn. There was symmetry of attrition between the left and right side. There was no significant difference between men and women.

DISCUSSION

Working on paired mandibles and maxillas showed that attrition in the middle age was a global phenomenon, intermaxillary and symmetric. It was much more severe than today, rapidly evolving and generalized because of the abrasive quality of food, cooking, chewing habits, and intensity of chewing pressure.

Survey of plasma and liver mineral concentrations and enzyme activities in ostriches (Struthio camelus) under farmed conditions in New Zealand

AIM

To generate clinical biochemical data to aid diagnosis of suboptimal performance in ostriches farmed under pastoral systems in New Zealand.

METHODS

Blood and liver samples were sought from three categories of bird, viz 3-12-week-old chicks, 7-12-month-old growers, and from breeding hens, managed under pastoral conditions on farms in several locations in New Zealand. Concentrations of the minerals Ca, PO4, Mg, Na, K, Cu and Zn, activities of the enzymes gamma-glutamyl transferase (GGT), creatine kinase (CK), lactate dehydrogenase (LDH) and aspartate aminotransferase (AST), and concentrations of total protein (TP) and uric acid and vitamin E in plasma and Se in whole blood were determined from four flocks of chicks, two flocks of growing and one flock of breeding birds. Concentrations of Cu, Fe and vitamin B12 were determined from liver samples from chicks and growing birds. Bodyweight was recorded at the times of blood-sampling, where this was feasible.

RESULTS

It proved impossible to obtain blood samples by venepuncture of the radial vein from chicks <3 months of age. Plasma concentrations of minerals, with the exception of K, which were higher, were within the normal range observed in the literature for ratite species. Activities in plasma of AST and CK were almost double, and those of LDH similar, to those in the literature for ostriches. There was considerable variation in activities of the enzymes between farms, but no association with growth performance. Concentrations of Cu in plasma were lower and in liver were higher than would be expected in farmed ruminants. Though hindgut fermenters, the birds maintained concentrations of vitamin B12 in plasma and liver at least comparable to those observed in ruminants.

CONCLUSIONS

Collection of blood samples by venepuncture via the wing in ostrich chicks younger than 3 months of age is difficult and unlikely to prove viable for routine diagnostic purposes. Clinical biochemistry data on mineral nutrients in ostriches farmed in New Zealand are similar to those in the literature from South Africa , but AST and CK are higher, and may be normal and a reflection of the high growth rates of the musculoskeletal system.

Virtual reality training improves simulated laparoscopic surgery performance in laparoscopy naïve medical students

PURPOSE

With the expanding role of laparoscopy in urologic practice, efficient and safe training has become paramount. Virtual reality simulation may potentially aid training, but it requires validation before it can be incorporated into training programs. The objective of this study was to assess whether training on a virtual reality (VR) laparoscopy simulator (LAP Mentor) can improve performance of virtual laparoscopic procedures.

MATERIALS AND METHODS

After a basic introduction to the LAP Mentor, 32 inexperienced medical students performed a baseline VR cholecystectomy that was observed and scored by two observers using the Objective Structured Assessment of Technical Skills (OSATS). The students were then randomized to two groups: Group 1 trained on the simulator without supervision during a total of six 30-minute sessions, and group 2 received no training. Students were then reevaluated on a second VR cholecystectomy by the same observers.

RESULTS

All 32 students completed the study. The two groups were comparable with regard to baseline OSATS scores (group 1, 16.6+/-4.3 v group 2, 15.67+/-6.3, P=0.2). On the second evaluation, the trained students (group 1) performed significantly better than the control group (group 2) (27.9+/-7.2 v 17.6+/-6.2, P<0.001). Group 1 students outperformed group 2 students in each category of the OSATS. Moreover, trained students improved their scores by at least 20% (P<0.001) in each category, while the untrained students improved only in the "knowledge of procedure" category by 25% (P=0.03).

CONCLUSION

Skills training on a LAP Mentor VR simulator improved VR surgical performance. Before incorporating this simulator into resident education, the LAP Mentor will have to undergo testing for predictive and construct validity.

About human tumor antigens to be used in immunotherapy

The choice of antigens to be used in cancer immunotherapy remains a crucial and difficult issue. This review highlights some properties of the different groups of human tumor antigens recognized by T lymphocytes, focusing on parameters that should influence this choice, such as tumor specificity and level of antigen expression.

T lymphocyte activation signals

Activation of T lymphocytes results in immediate biochemical changes including increases in intracellular calcium levels, activation of protein kinase C (PKC) and changes in tyrosine phosphorylation. In T cells recent studies have indicated that activation of the guanine nucleotide-binding proteins p21ras is mediated by PKC, which suggests that the p21ras proteins may regulate intracellular signalling events downstream of PKC. The p21ras proteins can be activated in T cells by signals generated by triggering of the T cell antigen receptor (TCR), the CD2 antigen and the interleukin 2 receptor. Experiments using a PKC pseudosubstrate inhibitor indicate that PKC does not mediate TCR-induced activation of p21ras. These results imply that an alternative signal transduction pathway not involving PKC can regulate the activity of p21ras proteins in T cells.

A randomized comparison of conventional vs articulating laparoscopic needle-drivers for performing standardized suturing tasks by laparoscopy-naive subjects

OBJECTIVES

To compare the efficacy of conventional and articulating laparoscopic needle-drivers for performing standardized laparoscopic tasks by medical students with no previous surgical experience.

SUBJECTS AND METHODS

Twenty medical students with no surgical experience were randomly assigned to two equal groups, one using a conventional laparoscopic needle-holder (Karl Storz, Tuttlingen, Germany) and the other using a first-generation articulating laparoscopic needle-holder (Cambridge Endo, Framingham, MA, USA). Each student performed a series of four standardized laparoscopic tasks, during which speed and accuracy were assessed. The tasks tested needle passage through rings (1), an oblique running suture model (2), a urethrovesical anastomosis model (3) and a model simulating renal parenchymal reconstruction following partial nephrectomy (4).

RESULTS

Tasks 1 and 3 were completed significantly more quickly by those using the conventional instruments (P < 0.05), but there was no statistically significant difference for task 2 and 4 (P > 0.05). Those using conventional instruments were significantly more accurate in all of the tasks than those using the articulated instruments (P < 0.05).

CONCLUSIONS

The conventional laparoscopic needle-driver allowed laparoscopy-naive medical students to complete a series of standardized suturing tasks more rapidly and accurately than with the novel articulating needle-driver. Laparoscopic suturing with first-generation articulating needle-drivers might be more difficult to learn, secondary to the complexity of physical manoeuvres required for their use.

Determination of biological vector characteristics and nanoparticle dimensions for radioimmunotherapy with radioactive nanoparticles

Radioimmunotherapy with biological vector labeled with radioactive nanoparticles is investigated from a dosimetric point of view. Beta (32P, 90Y) and low-energy X-ray radionuclides (103Pd) are considered. Dose distributions inside solid tumors have been calculated using MCNPX 2.5.0. Nanoparticle dimensions and biological vector characteristics are also determined in order to reach the 50 Gy prescribed dose inside the entire tumor volume. The worst case of an avascular tumor is considered. Results show that for beta-emitting nanoparticles, a set of data (covering fraction, biological half-life, and nanoparticle radius) can be found within acceptable ranges (those of classical radioimmunotherapy). These sources (with Emax approximately few MeV) can be used for the treatment of tumors with a maximum diameter of about 1 cm. Low-energy X-rays (E<25 keV) can be used to extend the range of tumor diameter to 4-5 cm but require very tight biological vector characteristics.

Sudden death in a patient newly diagnosed with diabetes having hyperosmolar non-ketotic acidosis with sickle cell trait

Sickle cell trait (SCT) has a UK urban population rate estimated at 3.2%. The condition may remain unrecognised, but sudden death is a recognised feature. The sudden death of a 51-year-old man with SCT who presented with hyperosmolar non-ketotic acidosis (HONK) as his first presentation of diabetes is reported here. After admission to hospital, a rapid deterioration was seen in his condition, with loss of cardiac output, leading to death. He was found to have had acute-chest syndrome and hepatosplenic infarction on postmortem examination. The pathophysiology of sudden death in patients with SCT and the role of HONK in the patient's demise is discussed here.

Comparative genomics of the lactic acid bacteria

Lactic acid-producing bacteria are associated with various plant and animal niches and play a key role in the production of fermented foods and beverages. We report nine genome sequences representing the phylogenetic and functional diversity of these bacteria. The small genomes of lactic acid bacteria encode a broad repertoire of transporters for efficient carbon and nitrogen acquisition from the nutritionally rich environments they inhabit and reflect a limited range of biosynthetic capabilities that indicate both prototrophic and auxotrophic strains. Phylogenetic analyses, comparison of gene content across the group, and reconstruction of ancestral gene sets indicate a combination of extensive gene loss and key gene acquisitions via horizontal gene transfer during the coevolution of lactic acid bacteria with their habitats.

The genome of black cottonwood, Populus trichocarpa (Torr. & Gray)

We report the draft genome of the black cottonwood tree, Populus trichocarpa. Integration of shotgun sequence assembly with genetic mapping enabled chromosome-scale reconstruction of the genome. More than 45,000 putative protein-coding genes were identified. Analysis of the assembled genome revealed a whole-genome duplication event; about 8000 pairs of duplicated genes from that event survived in the Populus genome. A second, older duplication event is indistinguishably coincident with the divergence of the Populus and Arabidopsis lineages. Nucleotide substitution, tandem gene duplication, and gross chromosomal rearrangement appear to proceed substantially more slowly in Populus than in Arabidopsis. Populus has more protein-coding genes than Arabidopsis, ranging on average from 1.4 to 1.6 putative Populus homologs for each Arabidopsis gene. However, the relative frequency of protein domains in the two genomes is similar. Overrepresented exceptions in Populus include genes associated with lignocellulosic wall biosynthesis, meristem development, disease resistance, and metabolite transport.

Cytokine mRNA expression in Mycobacterium ulcerans-infected human skin and correlation with local inflammatory response

Cytokine mRNA expression in biopsies of Mycobacterium ulcerans-infected human tissue was investigated using real-time PCR, and the findings were correlated with the clinical stages of disease and histopathologies. A broad range of cytokine mRNAs were detected in 16 early nodules and 28 late-stage ulcers, including those for the Th1 cytokines tumor necrosis factor alpha (TNF-alpha) and gamma interferon (IFN-gamma) and the Th2 cytokine interleukin 10 (IL-10). IFN-gamma was strongly expressed in both nodules and ulcers, suggesting that a Th1 response begins early in the disease. There was a significantly higher expression of IL-8 and other proinflammatory cytokines in results from 32 biopsies with neutrophilia than in those from 12 biopsies without acute inflammation. Ten tissue samples containing granulomas showed high mRNA expression for IFN-gamma, IL-1beta, IL-12p35, IL-12p40, IL-15, and TNF-alpha relative to 34 tissue samples without granulomas. These results suggest that the human immune response to M. ulcerans is similar to that seen with some other mycobacteria despite the presence of the toxin mycolactone in the tissues.

Cytokine response to antigen stimulation of whole blood from patients with Mycobacterium ulcerans disease compared to that from patients with tuberculosis

Mycobacterium ulcerans disease (Buruli ulcer) is a skin-ulcerating infection common in some parts of the tropics. We have investigated cytokine secretion after stimulation of whole blood from Buruli ulcer (BU) patients in a region of endemicity in Ghana with M. ulcerans sonicate or culture filtrate antigens to investigate the development of the response over time and its specificity by comparison with the response to Mycobacterium tuberculosis sonicate in human immunodeficiency virus-negative tuberculosis patients. Significant gamma interferon (IFN-gamma) production in response to whole-blood stimulation with M. ulcerans sonicate was detected in patients with ulcers, which was higher than that in patients with nodules but similar to subjects with healed BU. The mean IFN-gamma response in household contacts of BU patients was not significantly different from that in healthy control subjects from an area of nonendemicity. Results in patients with untreated, smear-positive pulmonary tuberculosis and tuberculosis patients on treatment for more than 2 weeks showed that BU patients responded better to M. ulcerans antigens than tuberculosis patients. In contrast, interleukin-10 results were higher in patients with active M. ulcerans disease than in those with healed lesions, but the pattern of response was similar to that seen in tuberculosis. A similar pattern of cytokine secretion was found using M. tuberculosis sonicate as an antigen. Neither of the two culture filtrate antigens of M. ulcerans appeared to be more specific than M. ulcerans sonicate. In the early stages of M. ulcerans disease there was a mixed Th1 and Th2 cytokine response, but the Th1 response emerged as the dominant type.

AAPM TG-43U1 formalism adaptation and Monte Carlo dosimetry simulations of multiple-radionuclide brachytherapy sources

This paper presents a preliminary study on multiple-radionuclide sources for brachytherapy. An adaptation of the AAPM TG-43U1 formalism is proposed in order to derive the dosimetry parameters of multiple-radionuclide sources from mono-radionuclides. The adapted formalism is applied to a bi-radionuclide case with the help of Monte Carlo calculations (MCNPX 2.5.0). InterSource seed loaded with 103Pd and 125I was chosen. This combination promotes a higher dose rate than InterSource125 (loaded with 125I) and deeper tissue penetration than InterSource103 (loaded with 103Pd) while reducing the dose at long distance (beyond 2.5 cm) relative to InterSource125. In conclusion, this work shows the benefits of combining different radionuclides inside the same seed and proposes an adaptation of the AAPM TG-43U1 formalism for the implementation of multiple-radionuclide sources in current treatment planning systems.

Factors affecting the loss of length associated with tunica albuginea plication for correction of penile curvature

PURPOSE

Loss of length is a common postoperative complaint of the patient who undergoes surgical correction of penile curvature. We investigate the factors influencing complications in patients who have undergone TAP for PD and chordee.

MATERIALS AND METHODS

A total of 102 patients underwent TAP for PD (68) or chordee (34) between 1997 and 2004. Data were gathered on each patient's preoperative complaints, physical examination, Doppler ultrasound, operative data and postoperative complaints. For the purposes of this study penile length was measured from pubis to corona along the dorsal surface of the stretched phallus.

RESULTS

Mean ages at surgery for men with PD and chordee were 53 and 24, respectively. A range of 1 to 6 plications were performed on each patient (mean 3) with an acceptably straight penis (curve less than 20 degrees) being achieved in 99% of patients. Mean followup for our patient population was 29 months and revealed only 1 patient with residual curvature. The mean loss in length after TAP was 0.36 +/- 0.5 cm with a range of 0 to 2.5 cm. When calculated as a percent of length lost from preoperative length, the postoperative percent length lost was 2.4%. When stratified into groups based on direction of curvature, the patients with ventral or ventrolateral curve had the highest percent loss of length. A 1-way ANOVA of these groups proved the differences between each group to be statistically significant (p = 0.04). Length change also significantly correlated with preoperative stretched penile length and the severity of curvature as measured in degrees in the operating room at time of surgery. Parameters that did not demonstrate a statistically significant impact on penile shortening included patient age, number of plications performed, plaque size, and hinge/narrowing effect due to a PD plaque.

CONCLUSIONS

The TAP procedure is a safe and effective means of correcting penile curvature, with similar overall outcomes between patients with PD and chordee. Shortening of the penis does commonly occur but is dependent on direction and degree of curvature, as well as the length of the phallus.

Efficacy of the combination rifampin-streptomycin in preventing growth of Mycobacterium ulcerans in early lesions of Buruli ulcer in humans

Mycobacterium ulcerans disease is common in some humid tropical areas, particularly in parts of West Africa, and current management is by surgical excision of skin lesions ranging from early nodules to extensive ulcers (Buruli ulcer). Antibiotic therapy would be more accessible to patients in areas of Buruli ulcer endemicity. We report a study of the efficacy of antibiotics in converting early lesions (nodules and plaques) from culture positive to culture negative. Lesions were excised either immediately or after treatment with rifampin orally at 10 mg/kg of body weight and streptomycin intramuscularly at 15 mg/kg of body weight daily for 2, 4, 8, or 12 weeks and examined by quantitative bacterial culture, PCR, and histopathology for M. ulcerans. Lesions were measured during treatment. Five lesions excised without antibiotic treatment and five lesions treated with antibiotics for 2 weeks were culture positive, whereas three lesions treated for 4 weeks, five treated for 8 weeks, and three treated for 12 weeks were culture negative. No lesions became enlarged during antibiotic treatment, and most became smaller. Treatment with rifampin and streptomycin for 4 weeks or more inhibited growth of M. ulcerans in human tissue, and it provides a basis for proceeding to a trial of antibiotic therapy as an alternative to surgery for early M. ulcerans disease.

Sensitivity of PCR targeting the IS2404 insertion sequence of Mycobacterium ulcerans in an Assay using punch biopsy specimens for diagnosis of Buruli ulcer

Punch biopsy specimens from Mycobacterium ulcerans disease lesions were used to compare the sensitivities and specificities of direct smear, culture, PCR, and histopathology in making a diagnosis of M. ulcerans disease in a field setting. PCR for the insertion element IS2404 was modified to include uracil-N-glycosylase and deoxyuridine triphosphate instead of deoxythymidine triphosphate to reduce the risk of cross contamination. The "gold standard" for confirmation of clinically diagnosed Buruli ulcer was a definite histological diagnosis, a positive culture for M. ulcerans, or a smear positive for acid-fast bacilli (AFB), together with a possible histological diagnosis. For 70 clinically diagnosed cases of M. ulcerans disease, the modified PCR was 98% sensitive and gave a rapid result. The sensitivities of microscopy, culture, and histology were 42%, 49%, and 82%, respectively. The use of a 4-mm punch biopsy specimen was preferred to a 6-mm punch biopsy specimen since the wound was less likely to bleed and to need stitching. Given adequate technical expertise and the use of controls, the PCR was viable in a teaching hospital setting in Ghana; and in routine practice, we would recommend the use of Ziehl-Neelsen staining of biopsy specimens to detect AFB, followed by PCR, in AFB-negative cases only, in order to minimize costs. Histology and culture remain important as quality control tests, particularly in studies of treatment efficacy.

Genetic elements of Thermococcales

This minireview summarizes our current knowledge about archaeal genetic elements in the hyperthermophilic order Thermococcales in the phylum Euryarchaeota. This includes recent work on the first virus of Pyrococcus, PAV1, the discovery of novel unique virus morphotypes in hot deep-sea environments, and preliminary observations on novel cryptic plasmids. We also review the work accomplished over the last 5 years in the development of genetic tools for members of the Pyrococcus and Thermococcus genera, mainly in our laboratories.

Pilot randomized double-blind trial of treatment of Mycobacterium ulcerans disease (Buruli ulcer) with topical nitrogen oxides

Mycobacterium ulcerans disease (Buruli ulcer) is a serious ulcerating skin disease which is common in many tropical countries. Standard treatment, by extensive excision and skin grafting, is not available in rural communities where the disease is common. We evaluated the efficacy and safety of treatment with topical nitrogen oxides. Thirty-seven patients with a clinical diagnosis of Buruli ulcer caused by M. ulcerans disease were randomly assigned to one of two groups. In one group, two creams containing sodium nitrite (6%, wt/wt) or citric acid monohydrate (9%, wt/wt) were applied daily for 6 weeks, while the other group received a placebo. In the second 6 weeks, both groups received the nitrogen oxide-generating combination of creams. Treatment was continued for another 4 weeks for patients whose ulcers were not healed after 12 weeks. The ulcer surface area was monitored by weekly tracings made by assessors blinded to the treatment. In the first 6 weeks, patients on sodium nitrite and citric acid monohydrate (group I, active treatment) showed a rapid decrease in ulcer size from 28.6 +/- 5.6 cm2 (mean +/- standard error) to 12.6 +/- 3.2 cm2, a decrease significantly greater than that in group II (from 15.3 +/- 3.1 to 11.7 +/- 3.7 cm2; P = 0.03). Five ulcers in the placebo group enlarged during this period, compared with one in the active group. In the second 6 weeks (both groups on active treatment), the rates of healing were similar for the two groups and there was a significant reduction in ulcer size in group II (previously on placebo) compared to the first 6 weeks. Yellow pigmentation of the skin, which disappeared 3 days after treatment was stopped, was the only side effect to date. We conclude that creams releasing nitrogen oxides increase the healing rate of ulcers caused by M. ulcerans infection with minimal adverse events. This is the first controlled trial of any form of therapy which demonstrates efficacy in treating this disease.

Increased Levels and Activity of E2F1 Transcription Factor in Myelodysplastic Bone Marrow

The bone marrow of patients with myelodysplastic syndromes (MDS) shows excessive intramedullary apoptosis, particularly in S-phase cells. In the light of previous reports that showed a link between experimental overexpression of the E2F1 transcription factor and apoptosis in the S phase, we compared the status of E2F1 protein in bone marrow mononuclear cells of MDS patients with that of healthy donors. Nearly 67% of MDS marrow samples showed higher expression of E2F1 transcription factor than in healthy donors. The retinoblastoma gene product, Rb, is a major negative regulator of E2F1 activity; however, Rb protein levels were found to be normal in MDS marrow samples. Amplification of genomic DNA by the polymerase chain reaction (PCR) showed no E2F1 gene amplification or mutation in the Rb-binding region of E2F1 in MDS patients, nor was transcriptional up-regulation noted when E2F1 messenger RNA (mRNA) levels were estimated with real-time reverse transcriptase-PCR. Furthermore, the overexpression of E2F1 was paralleled by its increased transcriptional activity, as reflected by the increased mRNA levels for one of its target genes, dihydrofolate reductase. Importantly, in a subset of the studied MDS patients for whom a simultaneous measurement of apoptosis in S-phase cells was possible, the E2F1 protein levels showed a significant positive correlation with this phenomenon. Previously, increased E2F1 activity in human disease had been found primarily as a consequence of Rb derailment. Hence, the observation in MDS of increased E2F1 activity in the presence of normal Rb levels is novel and unique, and E2F1 activity in association with apoptosis in S-phase cells may thus have significant therapeutic implications.