Transition between Instability and Seeded Self-Modulation of a Relativistic Particle Bunch in Plasma

We use a relativistic ionization front to provide various initial transverse wakefield amplitudes for the self-modulation of a long proton bunch in plasma. We show experimentally that, with sufficient initial amplitude [≥(4.1±0.4)  MV/m], the phase of the modulation along the bunch is reproducible from event to event, with 3%-7% (of 2π) rms variations all along the bunch. The phase is not reproducible for lower initial amplitudes. We observe the transition between these two regimes. Phase reproducibility is essential for deterministic external injection of particles to be accelerated.

Treatment of early-stage mycosis fungoides: results from the PROspective Cutaneous Lymphoma International Prognostic Index (PROCLIPI) study

BACKGROUND

The PROspective Cutaneous Lymphoma International Prognostic Index (PROCLIPI) study is a prospective analysis of an international database. Here we examine front-line treatments and quality of life (QoL) in patients with newly diagnosed mycosis fungoides (MF).

OBJECTIVES

To identify (i) differences in first-line approaches according to tumour-nodes-metastasis-blood (TNMB) staging; (ii) parameters related to a first-line systemic approach and (iii) response rates and QoL measures.

METHODS

In total, 395 newly diagnosed patients with early-stage MF (stage IA-IIA) were recruited from 41 centres in 17 countries between 1 January 2015 and 31 December 2018 following central clinicopathological review.

RESULTS

The most common first-line therapy was skin-directed therapy (SDT) (322 cases, 81·5%), while a smaller percentage (44 cases, 11·1%) received systemic therapy. Expectant observation was used in 7·3%. In univariate analysis, the use of systemic therapy was significantly associated with higher clinical stage (IA, 6%; IB, 14%; IIA, 20%; IA-IB vs. IIA, P < 0·001), presence of plaques (T1a/T2a, 5%; T1b/T2b, 17%; P < 0·001), higher modified Severity Weighted Assessment Tool (> 10, 15%; ≤ 10, 7%; P = 0·01) and folliculotropic MF (FMF) (24% vs. 12%, P = 0·001). Multivariate analysis demonstrated significant associations with the presence of plaques (T1b/T2b vs. T1a/T2a, odds ratio 3·07) and FMF (odds ratio 2·83). The overall response rate (ORR) to first-line SDT was 73%, while the ORR to first-line systemic treatments was lower (57%) (P = 0·027). Health-related QoL improved significantly both in patients with responsive disease and in those with stable disease.

CONCLUSIONS

Disease characteristics such as presence of plaques and FMF influence physician treatment choices, and SDT was superior to systemic therapy even in patients with such disease characteristics. Consequently, future treatment guidelines for early-stage MF need to address these issues.

The PROCLIPI international registry of early-stage mycosis fungoides identifies substantial diagnostic delay in most patients

BACKGROUND

Survival in mycosis fungoides (MF) is varied and may be poor. The PROCLIPI (PROspective Cutaneous Lymphoma International Prognostic Index) study is a web-based data collection system for early-stage MF with legal data-sharing agreements permitting international collaboration in a rare cancer with complex pathology. Clinicopathological data must be 100% complete and in-built intelligence in the database system ensures accurate staging.

OBJECTIVES

To develop a prognostic index for MF.

METHODS

Predefined datasets for clinical, haematological, radiological, immunohistochemical, genotypic, treatment and quality of life are collected at first diagnosis of MF and annually to test against survival. Biobanked tissue samples are recorded within a Federated Biobank for translational studies.

RESULTS

In total, 430 patients were enrolled from 29 centres in 15 countries spanning five continents. Altogether, 348 were confirmed as having early-stage MF at central review. The majority had classical MF (81·6%) with a CD4 phenotype (88·2%). Folliculotropic MF was diagnosed in 17·8%. Most presented with stage I (IA: 49·4%; IB: 42·8%), but 7·8% presented with enlarged lymph nodes (stage IIA). A diagnostic delay between first symptom development and initial diagnosis was frequent [85·6%; median delay 36 months (interquartile range 12-90)]. This highlights the difficulties in accurate diagnosis, which includes lack of a singular diagnostic test for MF.

CONCLUSIONS

This confirmed early-stage MF cohort is being followed-up to identify prognostic factors, which may allow better management and improve survival by identifying patients at risk of disease progression. This study design is a useful model for collaboration in other rare diseases, especially where pathological diagnosis can be complex.

Experimental Observation of Proton Bunch Modulation in a Plasma at Varying Plasma Densities

We give direct experimental evidence for the observation of the full transverse self-modulation of a long, relativistic proton bunch propagating through a dense plasma. The bunch exits the plasma with a periodic density modulation resulting from radial wakefield effects. We show that the modulation is seeded by a relativistic ionization front created using an intense laser pulse copropagating with the proton bunch. The modulation extends over the length of the proton bunch following the seed point. By varying the plasma density over one order of magnitude, we show that the modulation frequency scales with the expected dependence on the plasma density, i.e., it is equal to the plasma frequency, as expected from theory.

Experimental Observation of Plasma Wakefield Growth Driven by the Seeded Self-Modulation of a Proton Bunch

We measure the effects of transverse wakefields driven by a relativistic proton bunch in plasma with densities of 2.1×10^{14} and 7.7×10^{14}  electrons/cm^{3}. We show that these wakefields periodically defocus the proton bunch itself, consistently with the development of the seeded self-modulation process. We show that the defocusing increases both along the bunch and along the plasma by using time resolved and time-integrated measurements of the proton bunch transverse distribution. We evaluate the transverse wakefield amplitudes and show that they exceed their seed value (<15  MV/m) and reach over 300  MV/m. All these results confirm the development of the seeded self-modulation process, a necessary condition for external injection of low energy and acceleration of electrons to multi-GeV energy levels.

Acceleration of electrons in the plasma wakefield of a proton bunch

High-energy particle accelerators have been crucial in providing a deeper understanding of fundamental particles and the forces that govern their interactions. To increase the energy of the particles or to reduce the size of the accelerator, new acceleration schemes need to be developed. Plasma wakefield acceleration^1–5, in which the electrons in a plasma are excited, leading to strong electric fields (so called ‘wakefields’), is one such promising acceleration technique. Experiments have shown that an intense laser pulse^6–9 or electron bunch^10,11 traversing a plasma can drive electric fields of tens of gigavolts per metre and above—well beyond those achieved in conventional radio-frequency accelerators (about 0.1 gigavolt per metre). However, the low stored energy of laser pulses and electron bunches means that multiple acceleration stages are needed to reach very high particle energies^5,12. The use of proton bunches is compelling because they have the potential to drive wakefields and to accelerate electrons to high energy in a single acceleration stage¹³. Long, thin proton bunches can be used because they undergo a process called self-modulation^14–16, a particle–plasma interaction that splits the bunch longitudinally into a series of high-density microbunches, which then act resonantly to create large wakefields. The Advanced Wakefield (AWAKE) experiment at CERN^17–19 uses high-intensity proton bunches—in which each proton has an energy of 400 gigaelectronvolts, resulting in a total bunch energy of 19 kilojoules—to drive a wakefield in a ten-metre-long plasma. Electron bunches are then injected into this wakefield. Here we present measurements of electrons accelerated up to two gigaelectronvolts at the AWAKE experiment, in a demonstration of proton-driven plasma wakefield acceleration. Measurements were conducted under various plasma conditions and the acceleration was found to be consistent and reliable. The potential for this scheme to produce very high-energy electron bunches in a single accelerating stage²⁰ means that our results are an important step towards the development of future high-energy particle accelerators^21,22.

Electron acceleration to very high energies is achieved in a single step by injecting electrons into a ‘wake’ of charge created in a 10-metre-long plasma by speeding long proton bunches.

GHz modulation detection using a streak camera: Suitability of streak cameras in the AWAKE experiment

Using frequency mixing, a modulated light pulse of ns duration is created. We show that, with a ps-resolution streak camera that is usually used for single short pulse measurements, we can detect via an FFT detection approach up to 450 GHz modulation in a pulse in a single measurement. This work is performed in the context of the AWAKE plasma wakefield experiment where modulation frequencies in the range of 80-280 GHz are expected.

Azacitidine and donor lymphocyte infusions as first salvage therapy for relapse of AML or MDS after allogeneic stem cell transplantation

The combination of azacitidine and donor lymphocyte infusions (DLI) as first salvage therapy for relapse after allogeneic transplantation (allo-HSCT) was studied in 30 patients with acute myeloid leukemia (AML; n=28) or myelodysplastic syndromes (MDS; n=2) within a prospective single-arm multicenter phase-II trial. Treatment schedule contained up to eight cycles azacitidine (100 mg/m(2)/day, days 1-5, every 28 days) followed by DLI (from 1-5 × 10(6) to 1-5 × 10(8) CD3(+)cells/kg) after every second azacitidine cycle. A median of three courses azacitidine (range 1-8) were administered, and 22 patients (73%) received DLI. Overall response rate was 30%, including seven complete remissions (CRs, 23%) and two partial remissions (7%). Five patients remain in CR for a median of 777 days (range 461-888). Patients with MDS or AML with myelodysplasia-related changes were more likely to respond (P=0.011), and a lower blast count (P=0.039) as well as high-risk cytogenetics (P=0.035) correlated with the likelihood to achieve CR. Incidence of acute and chronic graft-versus-host disease was 37% and 17%, respectively. Neutropenia and thrombocytopenia grade III/IV occurred during 65% and 63% of treatment cycles, while infections were the most common grade III/IV non-hematological toxicity. Azacitidine and DLI as salvage therapy is safe, induces long-term remissions and may become an alternative for patients with AML or MDS relapsing after allo-HSCT.

Personality influences quality-of-life assessments in adult patients after allogeneic hematopoietic SCT: results from a joint evaluation of the prospective German Multicenter Validation Trial and the Fred Hutchinson Cancer Research Center

The influence of personality on health related quality of life (QoL) and physical functioning in the setting of allogeneic hematopoietic SCT (alloHSCT) is unknown. We conducted a joint evaluation within two independent cohorts of alloHSCT recipients to investigate the impact of personality on reported QoL and physical functioning. Two-hundred-eight patients (median age 44 years, range 18-72) of cohort 1 and 93 patients (median age 55 years, range 19-79) of cohort 2 after alloHSCT were evaluated. Personality was assessed using the 24-adjective measure (AM), which measures the Big-Five personality domains and the Life Orientation Test-Revised (LOT-R), measuring optimism and pessimism. QoL was measured using the Functional Assessment of Cancer Therapy with bone marrow transplantation subscale (FACT-BMT), Short Form 36 (SF-36), the human activity profile (HAP), as well as the NIH criteria-based cGVHD activity assessment form and the Lee cGVHD symptom scale. Neuroticism was significantly associated with worse function measured by the HAP and FACT-BMT. Optimism significantly improved QoL captured by the FACT-BMT. Pessimism significantly impaired physical function captured by the HAP and SF-36. Extraversion was significantly associated with reduced depression and lower severity of cGVHD symptoms reported by the patient and the physician. The results suggest that personality traits and pre-treatment QoL assessments should be measured in clinical trials to facilitate the interpretation of QoL data.

Efficacy and Tolerability of Alemtuzumab (CAMPATH-1H) in the Salvage Treatment of B-Cell Chronic Lymphocytic Leukemia—Change of Regimen Needed?

We report on the response rate and tolerability of Alemtuzumab (Campath-1H) in a series of heavily pretreated patients with B-CLL with a special focus on treatment-related problems. All patients tested positive for CD52 on B-lymphocytes before entering the trial. Thirteen patients with B-chronic lymphocytic leukemia (B-CLL), 1 prolymphocytic leukemia (PLL), 1 mantle cell lymphoma (MCL) and 1 leukemic immunocytoma (IC) transformed into a high-grade NHL were included. Median age was 62 years (range 40-73), and pretreatment consisted of median 3 prior regimens (range 1-11). All patients received 3, 10 and 30 mg of Campath-1H on sequential days, and then were subsequently scheduled for 30 mg 3 times weekly. Nine out of 16 patients responded. One patient attained complete remission (CR), 8 patients achieved partial remission (PR), while 4 patients had stable disease (SD). Three patients had progressive disease (PD). Beginning with initiation of treatment recurrent profound leukopenia became evident in 13 out of 16 patients leading to treatment discontinuation. Severe nonhematological toxicity (WHO grade IV bronchospasm) occurred in the first patient of this series, who initially had no concomitant steroids. Therefore, we developed a steroid co-medication regimen for the first 4 Campath-1H applications with quick tapering thereafter. Following this regimen, no infusion associated side effects WHO grade > II were observed. Infectious complications leading to treatment discontinuation consisted of pulmonary aspergillosis in one and bacterial pneumonia in another case. One patient with refractory B-CLL and Pneumocystis carinii pneumonia plus CMV reactivation died. In summary, Campath-1H appears to be effective against leukemic low-grade B-NHL, also in advanced stage. In our series, application 3 times weekly was not possible due to hematotoxicity. We recommend, therefore, flexible time intervals depending on the leukocyte counts. Whether a cumulative dosage according to 3 x 30 mg Campath-1H for 12 weeks is needed still remains to be clarified.

Growth hormone therapy in adults: rationales, results, and perspectives

This review outlines the present knowledge of the rationales, clinical aspects, and perspectives of a therapy with recombinant human growth hormone (rhGH) in adults. In patients with hypopituitarism the effects of rhGH replacement have been extensively studied. Recent clinical trials show that rhGH treatment improves most alterations of body composition and psychological performance, but many of the metabolic actions of GH remain equivocal. Although side effects after short-term administration are usually mild, the risks of severe long-term adverse effects are still uncertain. A supplementation with rhGH is also suggestive in advanced age and obesity, but the clinical results are controversial so far. The anabolic actions of rhGH were exploited in several recent trials including patients who were severely ill, malnourished, on chronic haemodialysis, or on total parenteral nutrition. Although nitrogen-sparing effects of GH have been demonstrated in most cases, the data do not indicate a clinical benefit in terms of reduced mortality, improved outcome, or accelerated recovery. Therefore, recommendations for the use of rhGH do not have any rationale in these patients yet. The efficacy of rhGH in the treatment of reproductive or immunological disorders remains elusive and needs further investigation. In conclusion, the application of rhGH is still an experimental therapy which should be performed under close observation in well-controlled clinical studies.

In vivo diagnosis of acute intestinal graft-versus-host disease by confocal endomicroscopy

BACKGROUND AND STUDY AIMS

Conventional histology with hematoxylin and eosin (H&E) staining is the accepted standard for diagnosing acute intestinal graft-versus-host disease (GvHD). Confocal endomicroscopy (CEM) is a noninvasive method that allows in vivo histology to be performed during endoscopy. The aim of this study was to evaluate CEM for the diagnosis of acute intestinal GvHD.

PATIENTS AND METHODS

This observational pilot study conducted between September 2006 and August 2008 included patients with acute diarrhea after stem cell transplantation, infectious diarrhea, or active ulcerative colitis. CEM (EC-3870CIFK, Pentax, Tokyo, Japan) was performed after intravenous injection of fluorescein 10% and topical application of acriflavine 0.05%.

RESULTS

A total of 35 patients with acute diarrhea after stem cell transplantation were examined. In 16 patients, CEM and histology showed no evidence of GvHD. In 14/19 patients with histologically confirmed GvHD, the diagnosis could already be established by CEM during ongoing endoscopy. In GvHD grade IV, near complete destruction of the colonic crypts ("flat mucosa") was visible. Control patients with infectious colitis (N = 15) or ulcerative colitis (N = 15) displayed inflammatory changes but no evidence of GvHD. Altogether, sensitivity of CEM was 74% and specificity was 100 %.

CONCLUSIONS

CEM improves rapid diagnosis of acute intestinal GvHD with high accuracy while performing endoscopy. Platelet transfusions and unnecessary biopsy acquisition can be avoided once acute intestinal GvHD has been diagnosed in vivo.

Patients at high risk for CMV infection and disease show delayed CD8+ T-cell immune recovery after allogeneic stem cell transplantation

Human cytomegalovirus (CMV) is a major cause of death after transplantation. The frequency of pp65-specific T cells was examined in 38 HLA-A2+ stem cell recipients during the first year after transplantation. Patients were divided into four groups based on donor/recipient serostatus: d+/r+ (n=17), d+/r- (n=7), d-/r+ (n=9) and d-/r- (n=5). Peripheral blood mononuclear cells were stimulated with the CMVpp65 peptide NLVPMVATV, and the specific T-cell frequency was assessed by interferon gamma (IFN-gamma) ELISPOT assay. Responding T cells were characterized by flow cytometry revealing a terminal differentiated effector phenotype. Surveillance of CMV infection was carried out by real-time polymerase chain reaction (n=26) or immunofluorescence (n=12). Infection was present in 7/9 d-/r+ high-risk patients, and CMV disease occurred exclusively in this group with delayed or absent virus-specific T-cell recovery. In contrast, 16/24 intermediate-risk patients showed CMV-specific T cells. Our data suggest that CMV infection and disease rates are elevated in high-risk patients with delayed CMV-specific T-cell immune reconstitution and lower in those with early recovery of T-cell immunity. We recommend preferring CMV seropositive donors for CMV seropositive recipients, as this should lead to durable CMV-specific T-cell responses soon after transplantation with consecutive protection from CMV disease.

Allogeneic hematopoietic cell transplantation following conditioning with 90Y-ibritumomab-tiuxetan

Radioimmunotherapy (RIT) of relapsed lymphoma is gaining increasing importance. Especially the commercially available anti-CD20 antibody 90Y-ibritumomab tiuxetan is currently under investigation in various trials including dose escalation and autologous hematopoietic progenitor cell support. It is not clear, however, whether the implementation of this radiolabeled antibody into another treatment option for relapsed or poor risk lymphoma patients-allogeneic hematopoietic cell transplantation-interferes with or delays successful engraftment. This study reports encouraging results with 2 relapsed lymphoma patients (1 transformed marginal zone lymphoma and 1 mantle cell lymphoma) who underwent allogeneic hematopoietic cell transplantation from HLA-matched donors. The conditioning regimen consisted of Rituximab 250 mg m(-2) on days -21 and -14, 0.4 mCi kg(-1) body weight 90Y-ibritumomab tiuxetan on day -14 and fludarabine (30 mg m(-2)) plus cyclophosphamide (500 mg m(-2)) on days -7 to -3. The data demonstrate that engraftment is fast and reliable with leukocytes >1 x 10(9) L(-1) on day 12 and platelets >50 x 10(9) L(-1) on day 10. Thus, the incorporation of radioimmunotherapy into allogeneic transplant protocols combines established modalities with proven anti-lymphoma activity and, hence, offers an attractive new therapeutic option for relapsed lymphoma patients.

Stem cell mobilization in multiple myeloma patients: Do we need an age-adjusted regimen for the elderly?

The upper age limit for autologous progenitor cell transplantation in multiple myeloma patients is increasing continuously. We examined whether this shift in the age of pretreated myeloma patients requires modification of mobilization regimen. We compared retrospectively 21 consecutive progenitor cell mobilizations in 15 pts < 60 years (median age 56, range 37-59) with 33 consecutive mobilizations in 23 pts > 60 years (median age 65, range 60-73) of age. The number of CD34 positive circulating cells before scheduled leukapheresis was a mean of 67,935 cells/mL (SEM +/- 17,614) in the younger population and a mean of 19,069 (SEM +/- 5,396) for older pts (P = 0.0027). In patients >60 years, 13/33 mobilizations (including 2 patients with 2 failing attempts) were not successful (39%), compared to 6/21 mobilizations (29%, including 1 patient with 3 failing attempts) in the younger population. The increased number of progenitor cells in the grafts of younger patients led to a more rapid regeneration of leukocytes and platelets after stem cell infusion. Our data show that stem cell mobilization in older multiple myeloma patients is inferior compared to a younger patient population. There is a trend towards more leukapheresis until the target stem cell dose has been collected, and the decreased number of progenitor cells in the actual graft delays engraftment of leukocytes and platelets. The overall number of unsuccessful mobilization attempts, however, did not differ significantly between both age groups. A special "age-adjusted" increase in the dose of growth factors seems unjustified. Improvements in timing of leukapheresis, growth factor application, and mobilizing chemotherapy regimen as well as the use of alternative cytokines should be investigated for both age groups.

Sterilization of a new medical device using broad-spectrum pulsed light

In the development of implantable medical devices, effective sterilization is an essential design element. This article outlines how broad-spectrum pulsed light (BSPL) has been implemented to sterilize a novel, implantable medical device. Components of the device have properties incompatible with most sterilization techniques. The unique characteristics of the device and sterilization method are described. Results are presented that show BSPL can be an effective sterilization method that has the potential to meet validation requirements to allow parametric release of the treated product.

[Not Available]

Mycotoxin analyses in the state of Vorarlberg were concentrated on the aflatoxins B1, B2, G1, G2 and occasionally M1, on Ochratoxin A (OTA) and Patulin. The analyses were carried out on high performance liquid chromatography. For fast screening a radio immuno affinity technique (CHARM II) was introduced and employed lately.The results prove that only very few food samples are not contaminated by mycotoxins. In some samples the mycotoxin content exceeded the limit several times. The actual average mycotoxin content of food was very low but with regards to the precautionary principle the intake of these mould-toxins should be further minimised.

Alix, a novel mouse protein undergoing calcium-dependent interaction with the apoptosis-linked-gene 2 (ALG-2) protein

ALG-2 is a EF hand calcium binding protein with sequence homologies to calmodulin. Vito et al have shown that ALG-2 expression is required for apoptosis following a number of death stimuli,1 although nothing is known about the effectors which underlie ALG-2 function. Here we have used ALG-2 as bait in a yeast two hybrid screen of a mouse brain cDNA library. We found that ALG-2 binds to itself and to a novel protein that we call ALG-2 interacting protein X, Alix. Using co-immunoprecipitation experiments, we confirmed ALG-2/ALG-2 binding and demonstrated that this interaction is calcium independent. ALG-2/Alix interaction was also validated by co-immunoprecipitation, but in this case, the binding was found to be strictly calcium dependent. Alix seems highly conserved throughout evolution since it shows significant homologies to a putative C. elegans protein (YNK-1) and to proteins of A. nidulans (PalA) and S. cerevisiae (BRO1). Alix is a potential regulator or downstream effector of ALG-2 action.

Dobutamine stress Doppler echocardiography: reproducibility and physiologic left ventricular filling patterns

Qualitatively, dobutamine stress echocardiography has become an established procedure. Quantitative results are in great demand but this is still difficult due to limited endo- and epicardial border definition. Transmitral Doppler variables are strictly quantitative and less subjective. Furthermore, ischemic alterations precede systolic ones (ischemic cascade). There are preliminary reports of the utility of dobutamine stress Doppler echocardiography, but proof of reproducibility and left ventricular filling patterns are still lacking. Fourteen healthy volunteers (10 men, 4 women, median age 25.9 years, range 21-32 years) were investigated according to the usual dobutamine stress echocardiographic protocol (5, 10, 15, 20, 30, 40 and 40 micrograms/kg/min + 0.5 mg atropine). At each titration step a standardized transmitral PW-Doppler recording with the sample volume positioned at the opened mitral leaflet tips was analyzed three times by two independent, experienced investigators. Of the early, late, and mean velocities (VmaxE, VmaxA, Vmean), time integrals (VTI-E, VTI-A, VTI), their ratios (E/A, E/A VTI), and various time intervals (Tacc, Tdec, E- and A-duration, FillT), VmaxE (0.82 to 1.09 m/s; P < 0.0001), VTI-E (16.17 to 17.19 cm; P < 0.0001) and Vmean (0.29 to 0.82 m/s; P < 0.0001) were found to have the greatest discriminatory power, commencing already at a dose of 10-15 micrograms/kg/min dobutamine. VmaxE and VTI-E demonstrated the smallest intra- and interobserver variation without any increase in variability during incremental dose titration. Assessment of the early diastolic filling pattern by Doppler echocardiography is a valuable quantitative and reproducible adjunct to conventional dobutamine stress echocardiography. Further controlled studies in coronary artery disease patients have to confirm, whether lower dobutamine doses could be used in the test and sensitivity increased due to better data acquisition in cases of limited echogenicity, less subjectivity, and earlier onset of ischemic alterations.

Identification of H-ras mutations in urine sediments complements cytology in the detection of bladder tumors

BACKGROUND

Urinary cytology has long been used as a noninvasive screen for the detection of urinary tract cancer but is limited by the generation of false positive and false negative results. More recently, molecular changes associated with urothelial neoplastic progression have been identified in DNA from urine sediments, demonstrating an alternative approach for identifying neoplastic change in the bladder.

PURPOSE

The purpose of this prospective study was to determine the value of detection of H-ras (also known as HRAS) mutations in urine sediment DNA as a clinical indicator of tumor presence, recurrence, and/or progression.

METHODS

Urine sediments were collected from 100 patients presenting with bladder tumors, with follow-up samples collected from 19 patients. DNA extracted from urine sediments was analyzed for changes in exon 1 of the H-ras gene, using single-strand conformation polymorphism (SSCP) analysis. A representative number of aberrant H-ras/SSCP migrating bands were excised and sequenced to confirm the presence of a mutation. Human bladder specimens were obtained from patients (93 of the 100 patients initially and 18 of the 19 patients studied by follow-up) and histologically evaluated for tumor content and grade.

RESULTS

Mutations in exon 1 of the H-ras gene were detected in urine sediments from 44% (44 of 100) of the patients; concordant results were obtained by cytologic analysis, where 33% (31 of 93) of the patients displayed positive cytology. Analysis of the distribution of abnormalities with tumor grade revealed greater detection of low-grade (1-2) lesions using ras analysis (47%) compared with cytology (16%). In contrast, cytology was more effective in identifying the presence of carcinoma in situ. Combined results from these two approaches substantially increased the sensitivity of tumor detection, resulting in the identification of tumors in 60% of patients.

CONCLUSIONS

Identification of H-ras mutations in DNA from urine sediments facilitates the detection of low-grade bladder tumors and, in combination with cytology, increases the overall tumor detection from 33% to 60%. Preliminary results in patient follow-up suggest that detection of H-ras mutations may have some clinical utility in detecting the presence of abnormal cells in the absence of an overt lesion following cystoscopy or positive cytology.

Interaction of G-actin with thymosin beta 4 and its variants thymosin beta 9 and thymosin beta met9

Thymosin beta 4 is a major actin sequestering peptide in vertebrate cells and plays a role in the regulation of actin monomer/polymer ratio. Thymosin beta 9 and thymosin beta met9 are minor variants of thymosin beta 4. The possible function of these peptides has been investigated by comparing the actin binding properties of these beta-thymosins. Thymosin beta 9 and thymosin beta met9 were found to inhibit polymerization of ATP-actin with identical KDs of 0.7-0.8 microM (as compared to 2 +/- 0.3 microM for thymosin beta 4); like thymosin beta 4, they bound to ADP-G-actin with a 100-fold lower affinity than to ATP-G-actin. The interaction of thymosin beta 4 and thymosin beta met9 with G-actin was weakened 20-fold upon oxidation of methionine-6 into methionine sulfoxide. Binding of thymosin beta 4 to G-actin was accompanied by a 15% increase in the fluorescence intensity of actin tryptophans, and a 10 nm emission blue shift. Methionine-6 played an important role in this effect. The fluorescence change was used to monitor the kinetics of thymosin beta 4 binding to G-actin in the stopped-flow. The reaction was bimolecular, with association and dissociation rate constants of approximately 1.5 microM-1 s-1 and 2 s-1 respectively, under physiological conditions. The possible physiological significances of methionine-6 oxidation and of the relatively slow binding kinetics in regulating thymosin beta 4 function in vivo is discussed.

Effects of gonadotropins, insulin and insulin-like growth factor I on ovarian oxytocin and progesterone production

Oxytocin is produced in the granulosa-derived cells of the ruminant corpus luteum where its gene is dramatically up-regulated within days of ovulation. Regulation of these processes is poorly understood but oxytocin release can be increased by insulin, insulin-like growth factor I (IGF-I), and gonadotropins. Here we have assessed interactions between these regulatory systems. Follicle-stimulating hormone (FSH), luteinizing hormone (LH) and human chorionic gonadotropin (hCG) caused dose-dependent release of oxytocin from bovine granulosa cells cultured in medium containing 100 ng/ml insulin. The gonadotropins also increased oxytocin mRNA levels and their effects were mimicked by forskolin. The effects of these stimuli on oxytocin and progesterone release were synergistically increased by insulin or IGF-I. Binding studies revealed separate binding sites with characteristics of insulin and IGF-I receptors. Insulin potentiated the effects of hCG and forskolin on oxytocin mRNA levels and release of oxytocin and progesterone in cells from follicles containing greater than 50 ng/ml estradiol. In cells from follicles containing less than 5 ng/ml estradiol these stimuli had little effect on oxytocin release although progesterone release was synergistically increased by insulin and forskolin. The data suggest that gonadotropins regulate oxytocin synthesis and release and that these effects are amplified by insulin or IGF-I acting via their own receptors. Changes associated with maturation of the target cells in vitro appear prerequisite for oxytocin production in response to increased cAMP levels in the presence of insulin or IGF-I.