Efficacy and safety of withholding antimicrobial therapy in children with cancer, fever and neutropenia, with a demonstrated viral respiratory infection: a randomized clinical trial

OBJECTIVES

To validate the efficacy and safety of withholding antimicrobial therapy in a new cohort of children with cancer and febrile neutropenia (FN) having a demonstrated viral respiratory tract infection (RTI).

METHODS

Prospective, multicenter, non-inferiority, randomized study, approved by the ethical committee, in children presenting with FN at seven hospitals in Chile, evaluated at admission for diagnosis of bacterial and viral pathogens. Children who were positive for a respiratory virus (RV), negative for a bacterial pathogen and had a favorable evolution after 48-72 hours of antimicrobial therapy were randomized to either maintain or withhold antimicrobial therapy. The primary endpoint was the percentage of episodes with uneventful resolution, whereas the secondary endpoints were days of fever/hospitalization, requirement of antimicrobial treatment readministration, sepsis, pediatric intensive care unit (PICU) admission and death.

RESULTS

A total of 301 of 939 children with FN episodes recruited between March 2021 and December 2023 had a RV as a unique identified microorganism, of which 139 had a favorable evolution at 48-72 hours and were randomized, 70 to maintain and 69 to withdraw antimicrobial therapy. The median days of antimicrobial therapy was 5 (IQR 3-6) versus 3 (IQR 3-6) days (p<0.001), with similar frequency of uneventful resolution (66/70 (94%) and 66/69 (96%), RR 1.01, (95% CI 0.93-1.09), absolute risk difference 0.01, (95% CI -0.05-0.08) and similar number of days of fever and days of hospitalization. No cases of sepsis, PICU admission or death were reported.

CONCLUSIONS

We validated the strategy of withdrawal antimicrobial therapy in children with FN and viral RTI, based on clinical and microbiological/molecular diagnostic criteria. This will enable advances in antimicrobial stewardship strategies with a possible future impact on antimicrobial resistance.

Random number generation by coherent detection of quantum phase noise

In 2010 Qi et al. [Opt. Lett.35(3), 312 (2010)] demonstrated a random number generator based on the drift of the phase of a laser due to spontaneous emission, The out-of-the-lab implementation of this scheme presents two main drawbacks: it requires a long and highly unbalanced interferometer to generate a random phase with uniform probability distribution, or alternatively, a shorter and slightly unbalanced interferometer that notwithstanding requires active stabilization and does not generate a uniform probability distribution without randomness extraction. Here we demonstrate that making use of the random nature of the phase difference between two independent laser sources and two coherent detectors we can overcome these limitations. The two main advantages of the system demonstrated are: i) it generates a probability distribution of quantum origin which is intrinsically uniform and thus in principle needs no randomness extraction for obtaining a uniform distribution, and ii) the phase is measured with telecom equipment routinely used for high capacity coherent optical communications. The speed of random bit generation is determined by the photodetector bandwidth and the linewidth of the lasers. As a by-product of our method, we have obtained images of how phase noise develops with time in a laser. This provides a highly visual alternative way of measuring the coherence time of a laser.

1414Vasodilator challenge with levosimendan as alternative to nitric oxide in advanced heart failure heart transplant candidates

Introduction

Vasodilator challenge (VC) during right heart catheterization in heart transplant (HTx) candidates is warranted whenever pulmonary artery (PA) systolic pressure ≥50 mmHg and either transpulmonary gradient (TPG) ≥15 mmHg or pulmonary vascular resistance (PVR) >3 WU as long as systolic arterial blood pressure >85 mmHg. Nitric oxide (NO) remains the mainstay but in doubtful cases a 24–48h course of diuretics, inotropes and vasoactive agents may be required. Our aim is to report our centre's experience with levosimendan (LEVO) as alternative to NO in VC in HTx candidates due to advanced heart failure (HF).

Methods

VC records with either NO (20 ppm for 5–10 mins) or within 72h of LEVO infusion (12 mg/kg/min for 24–48h) carried out between 2009 and September 2018 were retrieved from the centre's database. Analysis was carried out with Fisher's exact test or Student's t-test for categorical and continuous variables, respectively, or the equivalent non-parametric test for non-normal distribution variables. Data are presented as counts and percentage, or mean ± standard deviation and median, percentile 25–75, for categorical and continuous variables, respectively.

Results

Baseline demographic and clinical characteristics from 26 patients (NO=13; LEVO=13) were similar between groups (12% female; 54±10 years of age; left ventricular ejection fraction 20±7%; BNP 1550±1090 pg/mL; 88% on NYHA III-IV). Although no differences were observed in baseline cardiac index (CI, 1.6±0.3 vs 1.4±0.4 L/min.m-2, in NO and LEVO, respectively), LEVO patients showed higher right ventricular systolic (70±10 vs 60±13 mmHg; p=0.036) and diastolic pressures (16±4 vs 11±5 mmHg; p=0.009) and lower PA compliance (0.9±0.2 vs 1.3±0.4 ml/mmHg; p=0.007) as well as a trend for increased PA wedge pressure (26±4 vs 21±4 mmHg; p=0.09), translating worse hemodynamics. Upon VC only LEVO decreased PA pressure and the increase in CI was higher compared with NO (2.5±0.8 vs 1.9±0.5 L/min.m-2, p=0.004) thus PVR reduction was comparable between groups (7.8±2.7 to 4.7±1.8 vs 6.3±2.3 to 3.6±2.1 WU, respectively). Also, only LEVO increased right (497, 387–837 to 791, 570–946 mmHg.mL.m-2; p=0.006) and left ventricular stroke work index (895, 807–1364 to 1257, 1107–2957 mmHg.mL.m-2; p=0.005) and cardiac power output (0.4±0.1 to 0.6±0.1 W; p<0.001). Increase in PA compliance was also higher in LEVO (89±98 vs 22±30 Δ%, p=0.04). On the other hand, NO increased wedge pressure whereas LEVO had no effect thus TPG reduction was higher with NO (42±24% vs 17±27% drops, respectively; p=0.022). After HTx (NO=4; LEVO=10) mortality was similar in both groups (25% vs 30%; p=1.00).

Conclusion

LEVO is a safe and effective alternative in PVR reduction for VC. Its positive inotropic effect and long-lasting hemodynamic improvement may improve clinical status before HTx and allow better scrutiny of suitable candidates.

Statistical data for the tensile properties of natural fibre composites

This article features a large statistical database on the tensile properties of natural fibre reinforced composite laminates. The data presented here corresponds to a comprehensive experimental testing program of several composite systems including: different material constituents (epoxy and vinyl ester resins; flax, jute and carbon fibres), different fibre configurations (short-fibre mats, unidirectional, and plain, twill and satin woven fabrics) and different fibre orientations (0°, 90°, and [0,90] angle plies). For each material, ~50 specimens were tested under uniaxial tensile loading. Here, we provide the complete set of stress–strain curves together with the statistical distributions of their calculated elastic modulus, strength and failure strain. The data is also provided as support material for the research article: “The mechanical properties of natural fibre composite laminates: A statistical study” [1].

Efficacy and safety of withholding antimicrobial treatment in children with cancer, fever and neutropenia, with a demonstrated viral respiratory infection: a randomized clinical trial

OBJECTIVES

To determine efficacy and safety of withholding antimicrobials in children with cancer, fever and neutropenia (FN) with a demonstrated respiratory viral infection.

METHODS

Prospective, multicentre, randomized study in children presenting with FN at five hospitals in Santiago, Chile, evaluated at admission for diagnosis of bacterial and viral pathogens including PCR-microarray for 17 respiratory viruses. Children positive for a respiratory virus, negative for a bacterial pathogen and with a favourable evolution after 48 h of antimicrobial therapy were randomized to either maintain or withhold antimicrobials. Primary endpoint was percentage of episodes with uneventful resolution. Secondary endpoints were days of fever/hospitalization, bacterial infection, sepsis, admission to paediatric intensive care unit (PICU) and death.

RESULTS

A total of 319 of 951 children with FN episodes recruited between July 2012 and December 2015 had a respiratory virus as a unique identified microorganism, of which 176 were randomized, 92 to maintain antimicrobials and 84 to withdraw. Median duration of antimicrobial use was 7 days (range 7-9 days) versus 3 days (range 3-4 days), with similar frequency of uneventful resolution (89/92 (97%) and 80/84 (95%), respectively, not significant; OR 1.48; 95% CI 0.32-6.83, p 0.61), and similar number of days of fever (2 versus 1), days of hospitalization (6 versus 6) and bacterial infections throughout the episode (2%-1%), with one case of sepsis requiring admission to PICU in the group that maintained antimicrobials, without any deaths.

CONCLUSIONS

The reduction of antimicrobials in children with FN and respiratory viral infections, based on clinical and microbiological/molecular diagnostic criteria, should favour the adoption of evidence-based management strategies in this population.

Enhancement of the sensitivity of a temperature sensor based on fiber Bragg gratings via weak value amplification

We present a proof-of-concept experiment aimed at increasing the sensitivity of Fiber-Bragg-gratings temperature sensors by making use of a weak-value-amplification scheme. The technique requires only linear optics elements for its implementation and appears as a promising method for increasing the sensitivity than state-of the-art sensors can currently provide. The device implemented here is able to generate a shift of the centroid of the spectrum of a pulse of ∼0.035  nm/°C, a nearly fourfold increase in sensitivity over the same fiber-Bragg-grating system interrogated using standard methods.

Nanostep height measurement via spatial mode projection

We demonstrate an optical scheme for measuring the thickness of thin nanolayers with the use of light beam's spatial modes. The novelty in our scheme is the projection of the beam reflected by the sample onto a properly tailored spatial mode. In the experiment described below, we are able to measure a step height smaller than 10 nm, i.e., one-eightieth (1/80) of the wavelength with a standard error in the picometer scale. Since our scheme enhances the signal-to-noise ratio, which effectively increases the sensitivity of detection, the extension of this technique to the detection of subnanometric layer thicknesses is feasible.

Is there a link between influenza and type I diabetes? Increased incidence of TID during the pandemic H1N1 influenza of 2009 in Chile

Pandemic H1N1 2009 had the highest incidence in the middle-high income area of Santiago and affected mostly school age patients. Influenza A virus (IAVs) causes systemic and most commonly non-systemic infection. Interestingly, it is able to replicate only in the presence of trypsin-like enzymes, as lung and pancreas.

HYPOTHESIS

IAVs infection may trigger beta cell destruction and increase the incidence of T1DM.

METHODS

A retrospective observational study of new T1DM pediatric patients from database of Clinica Las Condes between 1995 and 2012.

RESULTS

From 58 patients, 44.7% were diagnosed between 2009 and 2010, coincident with the H1N1 virus outbreak. There were no differences in clinical neither metabolic parameters between those patients from the 2009-2010 period and the rest. From those patients with available antibody panel, it was negative in 30% of the 2009-2010 group vs. 12.5% of the rest of the cohort (p < 0.05). Only one 5.8 year old boy had history of H1N1 virus infection three months prior to the DM1 onset with negative antibodies.

CONCLUSIONS

The temporal coincidence suggests a possible link between T1DM and H1N1 virus, might be thought to be through direct cytopathic damage. Unfortunately we could only confirm H1N1 previous infection in only one case. Prospective studies in new T1DM cases are necessary to test this hypothesis.

Generation of polarization-entangled photon pairs in a Bragg reflection waveguide

We demonstrate experimentally that spontaneous parametric down-conversion in an AlxGa(1-x)As semiconductor Bragg reflection waveguide can make for paired photons highly entangled in the polarization degree of freedom at the telecommunication wavelength of 1550 nm. The pairs of photons show visibility higher than 90% in several polarization bases and violate a Clauser-Horne-Shimony-Holt Bell-like inequality by more than 3 standard deviations. This represents a significant step toward the realization of efficient and versatile self pumped sources of entangled photon pairs on-chip.

Helico-conical optical beams self-heal

An optical beam is said to be self-healing when, distorted by an obstacle, the beam corrects itself upon propagation. In this Letter we show, through experiments supported by numerical simulations, that Helico-conical optical beams self-heal. We observe the strong resilience of these beams with different types of obstructions, and relate this to the characteristics of their transverse energy flow.

[Prevalence of late complications and survival of patients undergoing cardiac transplantation: a single-center experience]

INTRODUCTION

Heart transplantation is the treatment of choice in severe heart failure despite maximal medical therapy, which has no other surgical alternatives and exhibiting no contraindications. The aim of this study was to analyze the prevalence of late complications and survival of patients undergoing cardiac transplantation at our Hospital Center.

METHODS

We evaluated 78 patients (mean age 43 ± 15 years) transplanted at our center between February 1987 and December 2011, with a mean follow-up of 6 years.

RESULTS

Of late complications after heart transplantation, allograft vascular disease was detected in 10 patients ( 12.8%), was the one with impact on mortality, being responsible for four deaths. The most frequent complication was hypertension in 54.6% of cases, followed by dyslipidemia (47.4%), renal failure (47.4%), diabetes mellitus (21.8%) and neoplasms (11.5%). Atrial tachyarrhythmias was observed in eight patients (10.3%). The overall survival of our population at first and tenth year after heart transplantation was 81% and 69%, respectively. The mean survival of patients was 15.6 years (Cl 95%: [12,6-18,7]).. There were 23 deaths (29.5%), nine (11.5%) of which occurred within the first 30 days after transplantation.

CONCLUSION

Cardiac transplantation remains a valid therapeutic option for patients with end-stage heart disease. Our center had a heart transplant survival rate and incidence of late complications similar to those seen in international registries.

Weak measurements with orbital-angular-momentum pointer states

Weak measurements are a unique tool for accessing information about weakly interacting quantum systems with minimal back action. Joint weak measurements of single-particle operators with pointer states characterized by a two-dimensional Gaussian distribution can provide, in turn, key information about quantum correlations that can be relevant for quantum information applications. Here we demonstrate that by employing two-dimensional pointer states endowed with orbital angular momentum (OAM), it is possible to extract weak values of the higher order moments of single-particle operators, an inaccessible quantity with Gaussian pointer states only. We provide a specific example that illustrates the advantages of our method both in terms of signal enhancement and information retrieval.

Fast beam steering with full polarization control using a galvanometric optical scanner and polarization controller

Optical beam steering is a key element in many industrial and scientific applications like in material processing, information technologies, medical imaging and laser display. Even though galvanometer-based scanners offer flexibility, speed and accuracy at a relatively low cost, they still lack the necessary control over the polarization required for certain applications. We report on the development of a polarization steerable system assembled with a fiber polarization controller and a galvanometric scanner, both controlled by a digital signal processor board. The system implements control of the polarization decoupled from the pointing direction through a feed-forward control scheme. This enables to direct optical beams to a desired direction without affecting its initial polarization state. When considering the full working field of view, we are able to compensate polarization angle errors larger than 0.2 rad, in a temporal window of less than ∼ 20 ms. Given the unification of components to fully control any polarization state while steering an optical beam, the proposed system is potentially integrable and robust.

True random numbers from amplified quantum vacuum

Random numbers are essential for applications ranging from secure communications to numerical simulation and quantitative finance. Algorithms can rapidly produce pseudo-random outcomes, series of numbers that mimic most properties of true random numbers while quantum random number generators (QRNGs) exploit intrinsic quantum randomness to produce true random numbers. Single-photon QRNGs are conceptually simple but produce few random bits per detection. In contrast, vacuum fluctuations are a vast resource for QRNGs: they are broad-band and thus can encode many random bits per second. Direct recording of vacuum fluctuations is possible, but requires shot-noise-limited detectors, at the cost of bandwidth. We demonstrate efficient conversion of vacuum fluctuations to true random bits using optical amplification of vacuum and interferometry. Using commercially-available optical components we demonstrate a QRNG at a bit rate of 1.11 Gbps. The proposed scheme has the potential to be extended to 10 Gbps and even up to 100 Gbps by taking advantage of high speed modulation sources and detectors for optical fiber telecommunication devices.

Efficacy of increasing dosages of clarithromycin for treatment of experimental Mycoplasma pneumoniae pneumonia

OBJECTIVES

Mycoplasma pneumoniae respiratory infection is a common cause of acute respiratory infection in children and adults. We evaluated the efficacy of increasing dosages of clarithromycin for the optimized therapy of M. pneumoniae respiratory infection in a mouse model.

METHODS

BALB/c mice were intranasally inoculated once with M. pneumoniae or SP4 broth (control). Groups of mice were treated with increasing dosages of clarithromycin (10, 25 or 75 mg/kg/day) or placebo subcutaneously daily. Groups of mice were evaluated after 1, 2, 3, 6 and 12 days of therapy. Outcome variables included quantitative M. pneumoniae culture, histopathological score of the lungs, bronchoalveolar lavage (BAL) cytokine/chemokine/growth factor concentrations and plethysmography after aerosolized methacholine to assess airway hyperresponsiveness.

RESULTS

Elevated dosages of clarithromycin resulted in greater antimicrobial efficacy with significantly reduced M. pneumoniae quantitative cultures (P < 0.05), as well as greater improvement in markers of disease severity with significantly reduced lung histopathology scores, BAL cytokine concentrations and airway hyperresponsiveness (P < 0.05).

CONCLUSIONS

Escalated dosing of clarithromycin resulted in significantly greater therapeutic efficacy in the treatment of experimental M. pneumoniae respiratory infection.

Fast optical source for quantum key distribution based on semiconductor optical amplifiers

A novel integrated optical source capable of emitting faint pulses with different polarization states and with different intensity levels at 100 MHz has been developed. The source relies on a single laser diode followed by four semiconductor optical amplifiers and thin film polarizers, connected through a fiber network. The use of a single laser ensures high level of indistinguishability in time and spectrum of the pulses for the four different polarizations and three different levels of intensity. The applicability of the source is demonstrated in the lab through a free space quantum key distribution experiment which makes use of the decoy state BB84 protocol. We achieved a lower bound secure key rate of the order of 3.64 Mbps and a quantum bit error ratio as low as 1.14×10⁻² while the lower bound secure key rate became 187 bps for an equivalent attenuation of 35 dB. To our knowledge, this is the fastest polarization encoded QKD system which has been reported so far. The performance, reduced size, low power consumption and the fact that the components used can be space qualified make the source particularly suitable for secure satellite communication.

The impact of steroids given with macrolide therapy on experimental Mycoplasma pneumoniae respiratory infection

BACKGROUND

Systemic steroids have been advocated in addition to antimicrobial therapy for severe Mycoplasma pneumoniae pneumonia. We evaluated the efficacy of clarithromycin, dexamethasone, and combination therapy for M. pneumoniae respiratory infection.

METHODS

Mice infected with M. pneumoniae were treated with clarithromycin, dexamethasone, combined clarithromycin/dexamethasone, or placebo daily; mice were evaluated at baseline and after 1, 3, and 6 days of therapy. Outcome variables included M. pneumoniae culture, lung histopathologic score (HPS), and bronchoalveolar lavage cytokine, chemokine, and growth factor concentrations.

RESULTS

Clarithromycin monotherapy resulted in the greatest reductions in M. pneumoniae concentrations. After 3 days of treatment, combination therapy significantly reduced lung HPS compared with placebo, clarithromycin, and dexamethasone alone, whereas, after 6 days of therapy, clarithromycin alone and combination therapy significantly reduced lung HPS compared with placebo. Concentrations of interleukin (IL)-12 p40, RANTES, macrophage chemotactic protein-1, and cytokine-induced neutrophil chemoattractant were significantly lower in mice treated with clarithromycin alone and/or combination therapy compared with dexamethasone alone and/or placebo; combination therapy resulted in a significantly greater reduction than clarithromycin alone for IL-12 p40 and RANTES.

CONCLUSIONS

Although monotherapy with clarithromycin had the greatest effect on reducing concentrations of M. pneumoniae, combination therapy had the greatest effect on decreasing levels of cytokines and chemokines as well as pulmonary histologic inflammation.

[Renal cell carcinoma extending into the right atrium. Case report]

We report the clinical case of a 48-year-old woman with advanced renal cell carcinoma, and an inferior vena cava thrombus extending into the right atrium. The patient underwent complete tumor excision with radical nephrectomy and inferior vena cava trombectomy using adjunctive cardiopulmonary bypass and deep hypothermic circulatory arrest. Pathological studies revealed no capsular invasion by the renal cell carcinoma. Eighteen months postoperatively the patient is asymptomatic and on immunosuppressive therapy for suspected metastatic disease. We discuss the morbilidity, mortality and long term survival of patients with similar presentation of renal cell carcinoma based in a review of the published literature. Long term survival after surgical treatment is possible in a patient with localized renal cell carcinoma extending into the right atrium. In patient with localized renal cell carcinoma and inferior vena cava tumor thrombus the cephalad extent of inferior vena caval involvement does not appear to influence the prognosis.

Tunable control of the frequency correlations of entangled photons

We experimentally demonstrate a new technique to control the type of frequency correlations of entangled photon pairs generated by spontaneous parametric downconversion. Frequency-correlated and frequency-anticorrelated photons are produced when a broadband pulse is used as a pump. The method is based on the control of the group velocities of the interacting waves and can be applied in any nonlinear medium and frequency band of interest.

[Evolution of strategies of revascularisation in acute coronary syndromes with ST elevation. Analysis of the data of RESURCOR]

The aim of this study was to describe the changes in strategy of revascularisation in acute coronary syndromes with ST elevation (ACS ST+) since setting up a health care network. The authors analysed the incidence of coronary angioplasty and of intravenous thrombolysis from a prospective permanent hospital register of patients with ACS ST+ in the three Northern Alps departments from october 1st 2002 to december 31st 2004. Respectively, 171 patients were enrolled in 2002 and 675 in 2003, and 588 in 2004. The use of percutaneous coronary intervention increased (57, 69, and 78% in 2002, 2003, 2004, p< 0.01) in relation to the increased use of immediate secondary percutaneous coronary intervention (27, 36, 43%, p< 0.01) although the use of primary percutaneous coronary intervention did not changed (30, 33, 35%, p= 0.17). These results were observed in hospitals with and without Percutaneous Coronary Intervention facilities. An increase in prehospital (49, 67, 68%, p= 0.02) and hospital thrombolysis (48, 68, 73%, p= 0.03) was only observed in patients managed in institutions without Percutaneous Coronary Intervention facilities. The average delay to arterial punction (120. 124, 100 minutes, p< 0.01) and to intravenous thrombolysis (40, 30, 25 minutes, p< 0.01) decreased during the same period. Patients with ACS ST+ more commonly benefit from coronary revascularisation at increasingly shorter intervals to treatment. This would seem to be related to the better coordination of practitioners after the implantation of a health care network.

How a Dove prism transforms the orbital angular momentum of a light beam

It is generally assumed that a light beam with orbital angular momentum (OAM) per photon of lh, is transformed, when traversing a Dove prism, into a light beam with OAM per photon of -lh. In this paper, we show theoretically and experimentally that this OAM transformation rule does not apply for highly focused light beams. This result should be taken into account when designing classical and quantum algorithms that make use of Dove prims to manipulate the OAM of light.

Trypanosoma cruzi isolates from Chile are heterogeneous and composed of mixed populations when characterized by schizodeme and Southern analyses

In total, 61 Chilean isolates of Trypanosoma cruzi, were analysed using schizodeme and Southern analysis, using as probes the highly variable regions of minicircles from cloned parasites. Isolates were collected and amplified from domestic and wild triatomines, and from infected subjects in all the endemic areas of Chile. Three major parasite genotypes could be detected in the domestic transmission cycle, whilst 1 major T. cruzi genotype is circulating in the wild transmission cycle. Schizodeme analysis suggested that T. cruzi isolates are mixed populations, whereas the Southern analyses detected only 3 mixed isolates using 4 selected minicircle segments as probes.

Observation of the orbital angular momentum spectrum of a light beam

We demonstrate an experimental scheme that allows the elucidation of the orbital angular momentum discrete spectrum of an arbitrary light signal. The orbital angular momentum spectrum is represented in a Laguerre-Gaussian mode base, and the spectral components are resolved in the frequency domain by exploiting the Doppler frequency shift that is imparted to rotating light beams.

Acute myeloid leukemia with MLL rearrangements: clinicobiological features, prognostic impact and value of flow cytometry in the detection of residual leukemic cells

The MLL gene, located at 11q23 band, is frequently disrupted by different chromosomal rearrangements that occur in a variety of hematological malignancies. MLL rearrangements are associated with distinct clinical features and a poor prognosis. The aim of this study was to analyze the incidence and the prognostic significance of MLL rearrangements in a consecutive series of adult AML patients and to determine the immunophenotypic features of these cases. The identification of abnormal immunophenotypes could be used for the detection of minimal residual disease (MRD). Ninety-three adult patients with de novo acute myeloid leukemia (AML) were analyzed by Southern blot in order to detect MLL rearrangements (MLL+). RT-PCR and genomic long-range PCR were performed to further characterize MLL partial tandem duplication (PTD) in those patients in whom conventional karyotype did not show 11q23 chromosomal translocations. All the patients were homogeneously immunophenotyped at diagnosis. MLL rearrangements were detected in 13 (14%) patients. Four patients (5%) showed 11q23 translocations by karyotypic conventional analysis. Nine patients (10%) revealed PTD of MLL and one patient showed a MLL cleavage pattern. The MLL+ patients usually expressed myeloid and monocytic antigens CD33 (12/13 cases), CD13 (9/13), CD117 (9/13), CD64 (11/13) and in some cases CD14 (4/11). HLA-DR was also positive in (12/13). Eight out of 13 cases expressed the stem cell marker CD34. Only one patient revealed lymphoid marker reactivity (CD7) and CD56 was expressed in 5/13 cases. All the MLL+ patients showed at least one aberrant phenotype at diagnosis, which allowed us to set out a simple panel for the MRD studies. Twenty-seven samples from eight patients in morphologic complete remission (CR) were analyzed using the aberrant immunologic combinations detected at diagnosis. Phenotypically abnormal cells were detected in all the patients who subsequently relapsed, whereas only one patient with MRD+ remained in CR. Owing to the high level of residual leukemic cells, the MLL+ patients showed a short CR duration and a poor survival. In conclusion, immunophenotyping may be a suitable approach to investigating MRD status in AML patients with PTD of the MLL gene.

Chronic left ventricular pseudoaneurism

We present the case of a 70-year-old white male presenting with an abnormal cardiac silhouette on the chest X-ray and complaining of fatigue in the week before hospital admission. Four months before admission he had a single prolonged ischemic chest pain episode. The ECG revealed an old true posterior myocardial infarction. The transthoracic echocardiogram showed a large left ventricular pseudoaneurysm and surgical resection was performed successfully. The etiology, diagnosis and treatment of left ventricular pseudoaneurysm are reviewed.

Are myeloma patients with renal failure candidates for autologous stem cell transplantation?

INTRODUCTION

Renal function is one of the most important prognostic factors in multiple myeloma (MM). Patients with renal failure are generally excluded from high dose therapy even though they display a poor prognosis with conventional chemotherapy schemes. The aim of this study was to analyze the outcome of MM patients with renal insufficiency undergoing autologous stem cell transplantation (ASCT), including the evaluation of the quality of PB stem cell collections, kinetics of engraftment, transplant-related mortality, response to high dose chemotherapy and survival.

MATERIALS AND METHODS

From a total of 566 valuable patients included in the MM Spanish ASCT registry, three groups of patients were defined: group BA, patients with abnormal renal function at diagnosis but normal at transplant (73 cases); group BB, patients with abnormal function both at diagnosis and at transplant (14 cases); and group AA (control group, 479 cases), patients who constantly had normal renal function.

RESULTS AND CONCLUSION

Patients from groups BA and BB presented with a significantly higher number of adverse prognostic factors, reflecting that we were dealing with high tumor MM cases, as compared with patients from group AA. The number of mononuclear cells, CD34+ cells and CFU-GM cells collected in patients with non-reversible renal insufficiency was similar to those harvested in MM patients with normal renal function. Moreover, neutrophil and platelet engraftments were identical in patients with and without renal failure (days +11 and +12, respectively). By contrast, transplant-related mortality (TRM) was significantly higher in group BB patients (29%) than in groups BA (4.1%) and AA (3.3%). In multivariate analysis only three variables showed independent influence on TRM: poor performance status (ECOG 3), hemoglobin <9.5 g/dl and serum creatinine > or =5 mg/dl. The response to high dose therapy was independent of renal function. Interestingly, 43% of patients from group BB showed an improvement in renal function (creatinine < 2 mg/dl) after transplant. The three-year overall survival from transplantation was 56, 49 and 61% for the BB, BA and AA groups, respectively, with a statistically significant difference favoring group AA (P<0.01). PFS did not differ significantly between the three groups of patients. In multivariate analysis the only unfavorable independent prognostic factors for overall survival were poor performance status either at diagnosis or at transplant, high beta(2)-microglobulin levels, and no response to transplant. According to these results, ASCT is an attractive alternative for MM patients with renal insufficiency, and it should not constitute a criterion for exclusion from transplant unless patients display poor performance status and very high creatinine levels (>5 mg/dl).

Stable spinning optical solitons in three dimensions

We introduce spatiotemporal spinning solitons (vortex tori) of the three-dimensional nonlinear Schrödinger equation with focusing cubic and defocusing quintic nonlinearities. The first ever found completely stable spatiotemporal vortex solitons are demonstrated. A general conclusion is that stable spinning solitons are possible as a result of competition between focusing and defocusing nonlinearities.

Pseudoaneurysm of the mitral-aortic fibrosa: myocardial ischemia secondary to left coronary compression

In the current study we describe the cases of 2 patients operated on for left-sided endocarditis, who later had myocardial ischemia develop secondary to left coronary artery compression from a pseudoaneurysm of the mitral-aortic fibrosa. Because the symptoms of angina persisted despite medical treatment, both patients had second surgeries. Myocardial revascularization was performed in 1 patient; the other patient, who had a severely depressed ventricular function, was given an orthotopic cardiac transplant.

Favourable effect of the combination of acute and chronic graft-versus-host disease on the outcome of allogeneic peripheral blood stem cell transplantation for advanced haematological malignancies

To assess the influence of graft-versus-host disease (GVHD) on the outcome of patients with advanced haematological malignancies (AHM) who received a primary, unmodified allogeneic peripheral blood progenitor cells transplant (allo-PBT) from a human leucocyte antigen (HLA) identical sibling donor, we analysed 136 patients with myeloid neoplasms (n = 70) or lymphoproliferative disorders (n = 66), transplanted at 19 Spanish institutions. Median age was 35 years (range 1-61). The cumulative incidence of relapse for all patients was 34% (95% CI, 26-42%), 41% (95% CI, 33-49) for patients without GVHD and 14% (95% CI, 3-25) (P = 0.001) for patients with acute and chronic GVHD. After a median follow-up of 11 months (range 2-49), 60 (44%) patients remained alive with an actuarial probability of overall survival and disease-free survival (DFS) at 30 months of 31% (95% CI, 21-41%) and 28% (95% CI, 17-39%) respectively. In patients surviving > 100 d, the low incidence of relapse in those with acute and chronic GVHD led to a DFS of 57% (95% CI, 38-76%) compared with a DFS of 34% (95% CI, 17-51%) in the remaining patients (P = 0.03). Our results indicate a reduced incidence of relapse for patients with AHM receiving an unmodified allo-PBT and developing acute and chronic GVHD, which results in an improved DFS.

Soliton algebra by vortex-beam splitting

We experimentally demonstrate the possibility of breaking up intense vortex light beams into stable and controllable sets of parametric solitons. We report observations performed in seeded second-harmonic generation, but the scheme can be extended to all parametric processes. The number of generated solitons is shown to be determined by a robust arithmetic rule.

DDT environmental persistence from its use in a vector control program: a case study

DDT contamination was investigated in soil, sediment, and chicken eggs from an endemic leishmaniasis area located in Rio de Janeiro City, Brazil. The last DDT application in this area was in 1990, for sand-fly vector control. Sampling campaigns were conducted in 1997 and 1999. DDT was extracted by use of a modified soxhlet apparatus and analysis was performed by gas chromatography with electron capture detector. The results show that, in 1997, soil samples contained up to 351 microg x kg(-1) x d x w. of summation operator DDT near the insecticide-sprayed sites. In 1999, the soil concentration decreased to 112 microg x kg(-1) x d x w. of summation operator DDT. Sediments from small creeks also showed low concentrations (up to 32.9 microg x kg(-1) x d x w. of summation operator DDT). Chicken eggs had, on average, 1.98 mg x kg(-1) summation operator DDT (twice FAO's maximum residue limit), comprising 82% of p,p'-DDE. Taking into account the egg results, DDT bioaccumulation is a question of concern. Considering just the egg consumption, it was estimated that DDT intake in the study area is 0.38x10(-4) mg x kg(-1) body weight x day(-1) whereas the reference maximum dose (US EPA) is 5x10(-4) mg x kg(-1) body weight x day(-1). This approach can be used to estimate DDT exposure in other places where DDT contamination may be of concern, especially in places where locally produced animals and eggs are a significant portion of the diet.

[Heart transplantation. Difficulties and perspectives]

In this article a revision of the several problems of cardiac transplantation in the Cardiothoracic Surgery Center of the Hospital of S. João is done. After a revision of the exams that have to be done and the contra-indications to surgery, the problems concerning the donors are considered. The principal conclusion to take out of is that, in the majority of the cases, the problem of the few number of cardiac transplants done, is not the scarcity of donors.

Eliminating the transverse instabilities of kerr solitons

We show analytically, numerically, and experimentally that a transversely stable one-dimensional [(1+1)D] bright Kerr soliton can exist in a 3D bulk medium. The transverse instability of the soliton is completely eliminated if it is made sufficiently incoherent along the transverse dimension. We derive a criterion for the threshold of transverse instability that links the nonlinearity to the largest transverse correlation distance for which the 1D soliton is stable.

Frequency doubling of femtosecond pulses in walk-off-compensated N-(4-nitrophenyl)-L-prolinol

We show how to exploit the high quadratic nonlinear coefficient of the organic crystal N-(4-nitrophenyl)-L-prolinol for generation and parametric mixing of ultrashort pulses by use of tilted-pulse techniques. The effective crystal length for subpicosecond operation is shown to be enhanced from tens of micrometers to tens of millimeters. Efficient frequency doubling of 100-fs pulses is predicted in walk-off-compensated geometries with peak intensities of a few megawatts per square centimeter.

Engineerable generation of quadratic solitons in synthetic phase matching

We show that the efficiency and the mismatch bandwidth of quadratic soliton formation under conditions of second-harmonic generation can be enhanced in an important way in synthetic phase-matching profiles. Soliton excitation in smooth but arbitrary profiles is shown to be well described by a reduced variational approach. The potential of abrupt, nonadiabatic profiles for improved soliton formation is numerically revealed.

Observation of a nonlinear mode in a cylindrical Fabry-Perot cavity

We report what is believed to be the first observation of a nonlinear mode in a cylindrical nonlinear Fabry-Perot cavity. The field enhancement from cavity buildup, as well as the large chi((3)) optical nonlinearity that is due to resonantly excited (85)Rb vapor, allows the nonlinear mode to form at low incident optical powers of less than 1 mW. The mode is observed to occur for both self-focusing and self-defocusing nonlinearity.

Observation of azimuthal modulational instability and formation of patterns of optical solitons in a quadratic nonlinear crystal

We report what is believed to be the first experimental demonstration of the azimuthal self-breaking of intense beams containing a vortex phase dislocation into sets of optical spatial solitons in a quadratic nonlinear material. The observations were performed in a KTP crystal.

Methylmercury in fish and hair samples from the Balbina Feservoir, Brazilian Amazon

The present study aimed to evaluate methylmercury in fish and human hair samples from an important hydroelectrical reservoir, Balbina (Brazil, Amazon). It presents a quite intense fishing activity and there is no known goldmining activity in its watershed. Fish and human hair were analyzed with a new extraction technique and measured by GC-ECD. Analytical quality was checked through intercomparisons between two laboratories with local samples and certified standards from IAEA. Methylmercury in hair ranged from 2.0 to 21.6 microg . g-1 with a mean of 8.76+/-5.20 microg . g-1 (N=20), while the methylmercury percentages were above 90. Fish presented methylmercury levels ranging from 0.03 to 0.9 microg small middle dot g-1 wet wt with a mean of 0.24+/-0.18 microg small middle dot g-1 wet wt (N=32), which is below the limit established for food by Brazilian legislation (0.5 microg small middle dot g-1 wet wt) and methylmercury mean percentages were above 95%. The total mean daily methylmercury intake ranged from 11 to 55 microg for 70% of the sampled population from the village based on a daily consumption of about 110 g of fish with methylmercury concentrations in the range of 0.1 to 0.5 microg . g-1. This calculation is consistent with methylmercury concentrations in hair samples in the range of 2.6 to 13.1 microg . g-1.

Transesophageal echocardiography on the presurgical and postsurgical evaluation of a coronary arteriovenous fistula

A 52-year-old man with a symptomatic condition-a huge left coronary artery fistula simulating a cor triatriatum sinister on transthoracic echocardiography-was referred to our center for surgery. Coronary angiography unequivocally established the diagnosis of a left coronary artery fistula and contrast opacification of the right atrium was observed. However, as a result of the size of the fistula, the entry site could not be defined with certainty. A transesophageal echocardiography (TEE) was then performed, and the opening site was clearly identified in the postero-lateral wall of the right atrium. After the surgical treatment transesophageal echocardiography was repeated, and it was confirmed that the surgical treatment had succeeded.

Intrapericardial paraganglioma

We describe the case of an intrapericardial pheochromocytoma located in the anterior surface of the heart and spreading over the pulmonary trunk. Under cardiopulmonary bypass (CPB) the tumor was removed. "En bloc" resection of the anterior wall of the right ventricular infundibulum and the pulmonary trunk was performed, with implantation of a fresh aortic homograft in the pulmonary position to avoid free pulmonary regurgitation.

MR findings in hereditary spherocytosis

The magnetic resonance findings of intrathoracic extramedullary hematopoiesis associated with bone marrow reconversion, and reticuloendothelial hemosiderosis in a 50-years-old are reported. Radiologic finding of extramedullary hematopoiesis was the first step to the diagnosis of previously unknown hereditary spherocytosis.

[Valve replacement with Macchi prosthesis]

OBJECTIVE

to evaluate the performance of a new ball valve prosthesis.

DESIGN

set up of two groups of patients who underwent mitral valve replacement with two different prosthesis: the Macchi prosthesis under evaluation and the well known Starr-Edwards model prosthesis. The chi-square test was used to compare the results.

PATIENTS

Patients referred for valvular surgery.

INTERVENTIONS

One group of 98 consecutive patients who underwent isolated mitral valve replacement with a Macchi prosthesis from January 1984 to June 30 1986 was compared to a matched group of 49 patients who received a Starr-Edwards prosthesis in the same period of time. Follow-up data were available from 99% patients in the Macchi group 96% in the Starr-Edwards group, with a mean follow-up time of 35.2 (2-57) and 42.9 (4-62) months, respectively.

RESULTS

There was no statistical difference in the incidence per 100 patients--month of prosthetic complications--thromboembolism, hemorrhagic events, prosthetic endocarditis, reoperation and mechanical failure.

CONCLUSIONS

In our experience and with the available follow-up data the Macchi prosthesis is a good cost effective option when there is indication for a ball valve prosthesis.

[Pseudoaneurysm of the outflow chamber of the left ventricle as a complication of bacterial endocarditis of the aortic valve -- a clinical case]

After reporting a clinical case of a patient with a Staphylococcus Aureus Acute Endocarditis involving the aortic valve being complicated with cardiac failure irresponsive to medical treatment, which required a surgical procedure, the authors describe the preoperative echocardiography features. These features have the particularity of identifying a pseudoaneurysm rising in the outflow tract of the left ventricle, that involves the annulus and the anterior mitral leaflet, opening into the left atrium. They also take the opportunity to review the main local complications of Infective Endocarditis, affecting native or prosthetic valves, and make some comments on the diagnostic echocardiographic possibilities.

[Aorto-left ventricular tunnel arising from the left sinus of Valsalva]

Aortic-left ventricular tunnel (ALVT) is a rare congenital anomaly in which an abnormal communication connects the ascending aorta with the left ventricle, bypassing the aortic valve. Usually the ALVT takes its origin from the right aortic sinus. We report a patient with an ALVT arising from the left sinus of Valsalva who underwent surgery at five months of age. The diagnosis was first established by two-dimensional echocardiography.

[Several critical aspects of the value of peripheral markers in depression (TRH test and dexamethasone depression)]

Studies of depression carried out for over 10 years have led to the discovery of biological tracers for depression. The authors have performed numerous TRH and dexamethasone tests and in their opinion, the present enthusiasm for these tests should be tempered. In several aspects the various values attributed to them seem to be questionable. Owing to the difficulty in codifying these tests, the authors question their diagnostic, pronostic, therapeutic and predictive values. The authors' own experience as well as the evolution of the publications throughout the world have been taken into consideration. Finally, the problem of interferences and the doubtful specificity of endocrine tests for depression have been dealt with.