Geochemical and isotopic study of abiotic nitrite reduction coupled to biologically produced Fe(II) oxidation in marine environments

Estuarine sediments are often characterized by abundant iron oxides, organic matter, and anthropogenic nitrogen compounds (e.g., nitrate and nitrite). Anoxic dissimilatory iron reducing bacteria (e.g., Shewanella loihica) are ubiquitous in these environments where they can catalyze the reduction of Fe(III) (oxyhydr)oxides, thereby releasing aqueous Fe(II). The biologically produced Fe(II) can later reduce nitrite to form nitrous oxide. The effect on nitrite reduction by both biologically produced and artificially amended Fe(II) was examined experimentally. Ferrihydrite was reduced by Shewanella loihica in a batch reaction with an anoxic synthetic sea water medium. Some of the Fe(II) released by S. loihica adsorbed onto ferrihydrite, which was involved in the transformation of ferrihydrite to magnetite. In a second set of experiments with identical medium, no microorganism was present, instead, Fe(II) was amended. The amount of solid-bound Fe(II) in the experiments with bioproduced Fe(II) increased the rate of abiotic NO₂^- reduction with respect to that with synthetic Fe(II), yielding half-lives of 0.07 and 0.47 d, respectively. The δ¹⁸O and δ¹⁵N of NO₂^- was measured through time for both the abiotic and innoculated experiments. The ratio of ε¹⁸O/ε¹⁵N was 0.6 for the abiotic experiments and 3.1 when NO₂^- was reduced by S. loihica, thus indicating two different mechanisms for the NO₂^- reduction. Notably, there is a wide range of the ε¹⁸O/ε¹⁵N values in the literature for abiotic and biotic NO₂^- reduction, as such, the use of this ratio to distinguish between reduction mechanisms in natural systems should be taken with caution. Therefore, we suggest an additional constraint to identify the mechanisms (i.e. abiotic/biotic) controlling NO₂^- reduction in natural settings through the correlation of δ¹⁵N-NO₂^- and the aqueous Fe(II) concentration.

[Prevalence of ten Immune-mediated inflammatory diseases (IMID) in Spain]

OBJECTIVE

Immune-mediated inflammatory diseases (IMID) are chronic and highly disabling diseases that share inflammatory sequences and immunological dysregulations. Considered as a disease in itself, the prevalence of IMID is virtually unknown. The aim of this study was to assess the prevalence of 10 selected UDI, including rheumatoid arthritis, psoriasis, psoriatic arthritis, ankylosing spondylitis, ulcerative colitis, Crohn's disease, systemic lupus erythematosus, hidradenitis suppurativa, sarcoidosis and uveitis in Spain.

METHODS

cross-sectional epidemiological study of point prevalence was made. This study was carried out through a series of computerized interviews in households chosen at random in 17 autonomous communities in Spain. A structured questionnaire was used to determine the frequency of diagnosis and the concurrence of 10 IMID in the respondents and other individuals belonging to the same family nucleus. The point prevalence estimates were used and compared with the objective of determining the frequency of IMID by age, sex and communities. The data were processed using Excel 2016 (Microsoft, Redmond, WA, USA) and the SPSS V.019 system (IBM Corp. Armonk, NY, USA) for statistical analysis using the usual statistical tests in this type of studies.

RESULTS

Of the 7,980 respondents, 510 were diagnosed with an IMID, representing a cross-sectional study of 6.39% (95% CI: 6.02-6.76). One, two, three or more members of the family were affected in 87.2%, 7.8% and 5% of positive relatives in IMID, respectively. The most recurrent diseases were psoriasis (2.69% [95% CI: 2.32-3.06]) and rheumatic arthritis (1.07% [95% CI: 0.70-1.44]). There were differences in prevalence due to sex (p = 0.004) and age (p = 0.000). No significant differences were identified related to geographic location (p = 0.819). Attendance of at least 2 IMID was reported in 8.9% of respondents.

CONCLUSIONS

The overall prevalence was of the IMID studied was 6.39%, psoriasis being the most frequent with 2.69%. This study constitutes an initial step to consider IMID as an independent disease within the health system..

Characteristics and management of primary and other immune thrombocytopenias: Spanish registry study

BACKGROUND

The natural history and its modulation by treatments administered for immune thrombocytopenia (ITP) in the clinical practice remains unknown. In addition, little information is available on the characteristics and management of ITP in Spain.

METHODS

We conducted an observational, multicenter, registry in 70 Hematology Services from Spain between 2009 and 2011, which included children from 2 months of age and adults with primary ITP or another ITP diagnosed within the last 6 months (platelet count [PC] < 100 × 10⁹/l). Patients were followed-up at 6 and 12 months.

RESULTS

484 patients were included (median [Q1, Q3] age 52 [29,74] years, 87.6% adults), 56% women, 10.5% with secondary ITP. Median (Q1, Q3) PC at diagnosis was 12 × 10⁹/l (4, 32); 72% of patients had bleeding symptoms (62% cutaneous bleeding, 29% oral cavity bleeding, 18% epistaxis). 81% of patients with primary ITP received first-line treatment, mainly with corticosteroids (>6 weeks in 59% of cases), either alone (41%) or associated with intravenous immunoglobulin (33%). The response (≥30 × 10⁹/L) to first-line treatment was 92%. A total of 19% of patients received second-line treatment and 6% additional treatments. At 12 months, 74% of primary ITP patients maintained a PC ≥ 100 × 10⁹/L in absence of treatment (10% still had hemorrhagic manifestations).

CONCLUSIONS

Characteristics of Spanish ITP patients are comparable to those from other countries. Although a high response rate to first-line treatments is observed, at 1 year, the disease persists in around one quarter of patients. Overall therapeutic management in Spain conforms to current recommendations, except for an excessive duration of corticosteroids therapy.

Distinct Dual C-Cl Isotope Fractionation Patterns during Anaerobic Biodegradation of 1,2-Dichloroethane: Potential To Characterize Microbial Degradation in the Field

This study investigates, for the first time, dual C-Cl isotope fractionation during anaerobic biodegradation of 1,2-dichloroethane (1,2-DCA) via dihaloelimination by Dehalococcoides and Dehalogenimonas-containing enrichment cultures. Isotopic fractionation of 1,2-DCA (ε_bulk^C and ε_bulk^Cl) for Dehalococcoides (-33.0 ± 0.4‰ and -5.1 ± 0.1‰) and Dehalogenimonas-containing microcosms (-23 ± 2‰ and -12.0 ± 0.8‰) resulted in distinctly different dual element C-Cl isotope correlations (Λ = Δδ¹³C/Δδ³⁷Cl ≈ ε_bulk^C/ε_bulk^Cl), 6.8 ± 0.2 and 1.89 ± 0.02, respectively. Determined isotope effects and detected products suggest that the difference on the obtained Λ values for biodihaloelimination could be associated with a different mode of concerted bond cleavage rather than two different reaction pathways (i.e., stepwise vs concerted). Λ values of 1,2-DCA were, for the first time, determined in two field sites under reducing conditions (2.1 ± 0.1 and 2.2 ± 2.9). They were similar to the one obtained for the Dehalogenimonas-containing microcosms (1.89 ± 0.02) and very different from those reported for aerobic degradation pathways in a previous laboratory study (7.6 ± 0.1 and 0.78 ± 0.03). Thus, this study illustrates the potential of a dual isotope analysis to differentiate between aerobic and anaerobic biodegradation pathways of 1,2-DCA in the field and suggests that this approach might also be used to characterize dihaloelimination of 1,2-DCA by different bacteria, which needs to be confirmed in future studies.

Treatment of invasive fungal disease using anidulafungin alone or in combination for hematologic patients with concomitant hepatic or renal impairment

BACKGROUND

Invasive fungal disease (IFD) treatment is challenging in hematologic patients due to drug interactions and toxicities that limit the use of the antifungal agents.

AIMS

To analyze retrospectively in terms of safety and potential efficacy anidulafungin therapy, alone or in combination.

METHODS

Our institutional guidelines recommended anidulafungin treatment in hematologic patients with suspected IFD and concomitant renal or liver impairment (to avoid drug interactions and preserve organ function).

RESULTS

From 2008 to 2013, 24 episodes of IFD occurring in 21 patients were classified as proven (4 cases), probable (15 cases) and possible (5 cases). Anidulafungin was administered alone (13%) or in combination (88%). Eight (33%) episodes were resolved, using monotherapy (1 out of 3, 33%) or a combined therapy (7 out of 21, 33%). Twelve cases (50%) were registered as failure (death due to IFD progression in 4 patients, and treatment change due to lack of efficacy in 8), and 4 cases (17%) were not evaluable (death unrelated to the IFD). Anidulafungin was not withdrawn in any case due to toxicity.

CONCLUSIONS

Anidulafungin therapy, alone or in combination, could be considered in hematologic patients with IFD and concomitant liver or renal impairment. Due to the low number of patients, we cannot draw any conclusion about efficacy.

Long-term safety and efficacy of eslicarbazepine acetate in patients with focal seizures: results of the 1-year ESLIBASE retrospective study

BACKGROUND

Eslicarbazepine acetate (ESL) is a new antiepileptic drug (AED) licensed as adjunctive therapy in adults with partial-onset or focal seizures.

OBJECTIVE

To evaluate in a clinical practice setting the long-term efficacy and safety of ESL in patients with focal seizures.

METHODS

ESLIBASE was a retrospective study that included all patients with focal seizures who started ESL between January 2010 and July 2012 at 12 hospitals. ESL was prescribed individually according to real-life practice. Efficacy and safety were evaluated over 1 year. Switching from carbamazepine (CBZ) and oxcarbazepine (OXC) was assessed.

RESULTS

Three hundred and twenty-seven patients were included; 78% of patients were taking ≥2 other AEDs at baseline. Most (87%) began ESL because of poor seizure control and 13% because of adverse events (AEs) with CBZ or OXC. After 1 year, 237 patients (72.4%) remained on ESL. At 3, 6 and 12 months, the responder rate was 46.3%, 57.9%, and 52.5%, and 21.0%, 28.0%, and 25.3% of patients were seizure free. The responder rate significantly increased when ESL was combined with a non-sodium channel-targeting drug (non-SC drug) (66.7%) versus an SC drug (47.7%; p<0.001). At 12 months, 40.7% of patients had ≥1 AE; AEs led to treatment discontinuation in 16.2%. Dizziness, nausea, and somnolence were the most common AEs. The tolerability profile improved in >50% of the patients who switched from CBZ or OXC to ESL because of AEs.

CONCLUSIONS

ESL was well tolerated and effective in a real-world setting over 1 year. Side-effect profile improved when OXC and CBZ recipients were switched to ESL.

[Economic evaluation of Thrombopoietin Receptor Agonists in the treatment of chronic primary immune thrombocytopenia]

PURPOSE

To develop a tool to assist the decision-making for selection of Thrombopoyetin Receptor Agonists of adult patients with chronic immune primary thrombocytopenia (PTI).

METHODS

Stochastic cost-effectiveness analysis with a 6-Health- States Markov model: stable, bleeding type 2, 3 or 4, post-type 4 bleeding and death. Each simulation analyzes a randomly generated scenario that describes patients characteristics, results measured in quality adjusted life years (QALYs) and costs (in ?2011). Distributions were obtained from the Spanish data of the European health survey of 2009, the INE estimate of population for 2011 and the 6-months clinical studies for Eltrombopag and Romiplostim. Utility values were obtained from the literature and the costs from Spanish official rates lists. A set of 10.000 random scenarios were generated and the patients evolution of each scenario was simulated during a time horizon of five years (in 2-weeks cycles). National Health System Perspective was used and the annual discount rate was set at 3%.

RESULTS

Eltrombopag showed more effectiveness in 9.983 scenarios and there was no difference in 17. In 7.048 scenarios the alternative Eltombopag was dominant. It was cost-effective in another 19 (threshold 30,000 ??/AVAC).

CONCLUSIONS

Eltrombopag was the most cost-effective alternative in 70,67% of the simulated scenarios and its use could produce lower costs to the NHS.

Peripheral nerve hyperexcitability: a clinical and immunologic study of 38 patients

OBJECTIVE

We studied a case series of peripheral nerve hyperexcitability (PNH) aiming to describe clinical characteristics, immunologic and cancer associations, antibodies against neuronal antigens (voltage-gated potassium channel antibodies [VGKC-Abs] and other), and muscle biopsy findings.

METHODS

Patients presenting with clinical and electrophysiologic signs of PNH were selected. We studied clinical and electrophysiologic features; a panel of non-neuronal organ-specific antibodies, immunofluorescence on rat nervous tissues, and radioimmunoprecipitation for VGKC-Abs; and muscle biopsies.

RESULTS

Thirty-eight patients were included. After the exclusion of 6 cases with axonopathy of known origin, patients were subdivided according to the presence of electrophysiologic findings of motor axonopathy and association with cancer: axonopathic-PNH (group A: 12 patients), isolated nonparaneoplastic PNH (group B: 16 patients), and isolated paraneoplastic PNH (3 with thymoma and myasthenia gravis, 1 with thyroid carcinoma). PNH clinical features were similar in groups A and B. We found an overall high prevalence of clinical autoimmunity (33% of group A and 63% of group B) and systemic non-neuronal autoantibodies (42% of group A and 75% of group B). However, VGKC-Abs were only positive in 2 patients of group B. Ten patients underwent muscle biopsy, which showed inflammatory changes in 2 cases and nonspecific myopathic features in 8.

CONCLUSIONS

PNH is a heterogeneous disorder involving the peripheral nerves in patients with a high propensity for developing autoimmunity. Associated muscle diseases are frequent in the form of myositis, myasthenia gravis, or nonspecific myopathic pathologic findings. VGKC-Abs were uncommon in this series.

Usefulness of Video-EEG monitoring in patients with drug-resistant epilepsy

OBJECTIVE

To evaluate the characteristics of patients on whom long-term Video-EEG monitoring is performed in a specialist centre and to assess its suitability to study refractory epilepsy patients.

METHODS

A prospective analysis and study of Video-EEG monitoring was performed in a series of 100 refractory epilepsy patients from a single centre. The analysis included demographic data, the time until the first seizure, the methods used to provoke seizures, and the outcome (usefulness, change in the management, pharmacological and surgical improvement). A subgroup analysis based on diagnosis was performed.

RESULTS

The study was performed mainly on young people (mean 34.4 years) and the first seizure appeared in a mean of 30hours, requiring most of the patients to withdraw the medication. Nevertheless, there were no cases of status epilepticus. The usefulness of the test was high in all the groups. The management was changed in 65% of the patients with pharmacological and surgical improvement.

CONCLUSION

Long-term Video-EEG monitoring is a suitable test to study refractory epilepsy patients. The main problem in our country is accesibility.

Long-term management of chronic immune thrombocytopenic purpura in adults

Chronic immune thrombocytopenic purpura (ITP) is generally a more benign disease than previously thought. Currently it is recommended that only those patients with severe and/or symptomatic thrombocytopenia definitely require treatment. Additional factors, such as age, lifestyle, and uremia can also influence the hemorrhagic risk and should be carefully assessed before decision-making on the appropriate management of patients with less severe forms of ITP. The recent introduction of new classes of therapeutic agents such as rituximab and the thrombopoietic growth factors has had a major impact on the management of ITP. Updated treatment guidelines have recently been made available but they are based largely on expert opinion rather than on high-quality clinical trial evidence. This structured review is focused on the management of adults with chronic ITP, including the use of new classes of agents.

Impact of hematopoietic chimerism at day +14 on engraftment after unrelated donor umbilical cord blood transplantation for hematologic malignancies

BACKGROUND

Cord blood transplant is a feasible treatment alternative for adult patients with hematologic malignancies lacking a suitable HLA-matched donor. However, the kinetics of myeloid recovery is slow, and primary graft failure cannot be detected easily early after transplantation. We investigated the impact of hematopoietic chimerism status from unselected marrow cells 14 days after transplantation on predicting engraftment after a cord blood transplant.

DESIGN AND METHODS

Seventy-one adult patients with hematologic malignancies undergoing single-unit unrelated donor cord blood transplantation after a myeloablative conditioning regimen were included in the study. All patients received conditioning regimens based on busulfan, thiotepa and antithymocyte globulin. Chimerism status was assessed analyzing short tandem repeat polymorphisms.

RESULTS

The cumulative incidence of myeloid engraftment at 1 month was significantly lower in patients with mixed chimerism than in those with complete donor chimerism (55% vs. 94%; p<0.0001). For patients achieving myeloid recovery, the median time of engraftment was 16 days when donor chimerism at day + 14 was higher than 90%, compared with 24 days when donor chimerism was below this level (p<0.001). A donor chimerism level of 65% was found to be the best cut-off point for predicting primary graft failure, with a sensitivity of 97% and a specificity of 80%. The incidence of primary graft failure was 67% for patients with less than 65% donor chimerism at day +14 as compared to only 2% for those with more than 65% donor chimerism (p<0.001). Patients with mixed chimerism also had a lower cumulative incidence of platelet engraftment than those with complete chimerism (62% vs. 89%; p=0.01).

CONCLUSIONS

Donor-recipient chimerism status at day +14 predicts engraftment after a single-unit cord blood transplant in adults.

Incidence, risk factors, and outcome of cytomegalovirus infection and disease in patients receiving prophylaxis with oral valganciclovir or intravenous ganciclovir after umbilical cord blood transplantation

There is no information on the efficacy and safety of anticytomegalovirus (CMV) prophylaxis with intravenous ganciclovir or oral valganciclovir after unrelated cord-blood transplantation (UCBT). This issue was addressed in 151 adults (117 CMV-seropositive) undergoing UCBT at a single institution. The first 38 CMV-seropositive recipients were assigned to receive prophylactic ganciclovir, and the next 79 were given valganciclovir after engraftment. The cumulative incidence (CI) of CMV infection and disease was similar in patients receiving valganciclovir or ganciclovir (59% versus 55%, P = .59; and 9% versus 18%, P = .33, respectively). The toxicity profile and CI of nonrelapse mortality (CMV) and infection-related mortality did not differ between drugs. Patients receiving valganciclovir required fewer visits to the day hospital (P = .04). The CI of CMV infection and disease in 34 CMV-seronegative recipients was 12% and 6%, indicating that tight CMV monitoring is mandatory in this subset. The recipient's CMV serostatus, acute and extensive chronic graft-versus-host disease (aGVHD, cGVHD) were the main risk factors for CMV infection, and aGVHD for CMV disease. This study suggests that prophylaxis with oral valganciclovir is as safe and effective as intravenous ganciclovir for preventing CMV infection and disease after UCBT, but valganciclovir reduces the use of hospital resources.

Prenatal diagnosis of clubfoot in low-risk population: associated anomalies and long-term outcome

OBJECTIVES

To evaluate associated congenital anomaly risk, need for surgical treatment and long-term outcome in prenatally diagnosed clubfoot.

METHODS

A retrospective study of 20 663 pregnant women who underwent routine ultrasound scanning at 18 to 22 weeks of gestation. Clubfoot was considered as complex or isolated if other structural or chromosomal abnormalities were also present or not.

RESULTS

Forty-two cases of congenital clubfoot were diagnosed (incidence: 0.2%), 28 of them (66.6%) were isolated and 14 (33.3%) were complex, of which 3 (7.1%) had an abnormal karyotype and 11 (26.2%) had an associated structural anomaly. The false-positive rate was 2.3% (1 out of 32 liveborns). Out of the 41 confirmed affected fetuses, the defect was unilateral in 12 (29.3%) and bilateral in 29 (70.7%) cases. Surgery was necessary in 12 of the newborns (38.7%). The presence of a bilateral clubfoot was unrelated to either the presence of associated anomalies (p = 0.40) or to the necessity of surgery (p = 0.48).

CONCLUSIONS

We provide outcome data about fetuses prenatally diagnosed for clubfoot. One-third are complex cases associated with other congenital anomalies. For isolated clubfoot, the risk of requiring surgery is about 40%. The detection of a bilateral defect does not worsen the prognosis.

Compound-specific carbon isotope analysis of volatile organic compounds in water using solid-phase microextraction

The compound-specific isotope analysis technique in conjunction with solid-phase microextraction using a carboxen-polydimethylsiloxane fiber was tested and implemented for isotopes analyses of organic compounds aiming for environmental application in contaminated groundwater. delta(13)C values of several chlorinated methanes and ethenes, toluene and chlorobenzene were determined using a gas chromatograph coupled to an isotope ratio mass spectrometer through a combustion interface. Direct and headspace solid-phase microextraction (D-SPME, HS-SPME) methods were tested in order to determine the optimum conditions to obtain reproducible delta(13)C values at very low concentration (microg/L range) and, to elucidate the carbon isotopic effects associated with the competitive extraction. For D-SPME, higher accuracy and precision of delta(13)C results were obtained with no salted aqueous standards. Despite that the delta(13)C of those compounds analyzed with both methods showed similar precision (<0.5 per thousand) and accuracy, the highest sensitivity was reached with HS-SPME. Furthermore, the delta(13)C values of cis-1,2-dichloroethylene, chorinated methanes and aromatic compounds obtained using HS-SPME showed measurable deviations with respect to the isotopic composition of pure phase compounds, however, these deviations are constant according to the analytical uncertainties, indicating that they are not affected by competitive extraction, and they could be corrected using standard correction technique based on internal calibrated standards.

[Incidence of influenza and influenza vaccine effectiveness in the 2004-2005 season]

BACKGROUND

To quantify the incidence of flu in different groups of the population of Navarra in the 2004-2005 season, and to evaluate the effectiveness of anti-flu vaccination.

METHODS

The analysis of influenza cases in the system of compulsory notificable diseases was complemented by the individualised notifications in the network of sentinel doctors that covers a population of 22,339 inhabitants. The coverage and effectiveness of the vaccine was studied.

RESULTS

Vaccine coverage in (3)65 year olds reached 62%. The incidence of influenza was 42.6 cases per 1,000 inhabitants. It reached a maximum in mid-January, exceeding 750 weekly cases per 100,000 inhabitants and 1,900 cases per 100,000 children. The highest rate of influenza was observed in under-15 year olds (49.4 cases per 1,000 inhabitants) and the lowest in non-institutionalised (3)65 year olds (2.6 per 1,000 inhabitants), although it was higher in geriatric residences (62.1 per 1,000; p<0.0001). Seventy-nine percent of the cases from 5 to 64 years resulted in absenteeism from school or work. The flu virus was identified in 42/65 (65%) nasopharyngeal smears, 90% being influenza virus A(H3). The incidence of influenza was 3.08% in the unvaccinated and 0.45% in the vaccinated (p<0.001). The global effectiveness of the anti-flu vaccine was 65%, and in (3)65 years old it was 73%.

CONCLUSION

Although its effectiveness is not total, the vaccine is the main measure for preventing influenza. The network of sentinel doctors provide useful information for the coordination of care and public health activities against flu.

Prevalence of left ventricular hypertrophy in patients with mild hypertension in primary care: impact of echocardiography on cardiovascular risk stratification

BACKGROUND

Left ventricular hypertrophy (LVH) is an important predictor of cardiovascular risk, and its detection contributes to risk stratification. The aims of the present study were to estimate the prevalence of echocardiographic LVH and to evaluate the influence of echocardiography (ECHO) on cardiovascular risk stratification in hypertensive patients presenting in primary care.

METHODS

In this cross-sectional study, 250 patients recently diagnosed with mild hypertension underwent clinical evaluation including electrocardiography (ECG), microalbuminuria measurement, 24-h blood pressure monitoring and ECHO. Level of cardiovascular risk was stratified, initially using routine procedures including ECG to assess target organ damage and then again after detection of LVH by ECHO.

RESULTS

The frequency of echocardiographic LVH was 32%, substantially higher than that detected by ECG (9%). Initial cardiovascular risk stratification yielded the following results: 30% low risk, 49% medium risk, 16% high risk, and 5% very high risk subjects. The detection of LVH by ECHO provoked a significant change in the risk strata distribution, particularly in those patients initially classified as being at medium risk. In this group, 40% of subjects were reclassified as high risk subjects according to ECHO information. The new classification was as follows: 23% low risk, 30% medium risk, 42% high risk, and 5% very high risk subjects.

CONCLUSIONS

A substantial proportion of mildly hypertensive patients presenting in primary care have LVH determined by ECHO. Our results suggest that this procedure could significantly improve cardiovascular risk stratification in those patients with multiple risk factors, but no evidence of target organ damage by routine investigations.

Cefepime plus amikacin versus piperacillin-tazobactam plus amikacin for initial antibiotic therapy in haematology patients with febrile neutropenia: results of an open, randomized, multicentre trial

BACKGROUND

Standard therapy for suspected infections in patients with profound neutropenia is the combination of a beta-lactam antibiotic plus an aminoglycoside. Cefepime's broad-spectrum activity makes it an option for initial empirical therapy in neutropenic patients. The aim of this study is to evaluate the efficacy and safety of cefepime plus amikacin compared with piperacillin-tazobactam plus amikacin for initial empirical treatment of fever in adult haematology patients with severe neutropenia.

METHODS

In this prospective multicentre trial, 969 patients with 984 febrile neutropenic episodes were randomized to receive iv amikacin (20 mg/kg every 24 h) combined with either cefepime (2 g every 8 h) or piperacillin-tazobactam (4 g/500 mg every 6 h). Clinical response was determined at 72 h and at completion of therapy.

RESULTS

Eight hundred and sixty-seven episodes were assessable for efficacy (432 cefepime, 435 piperacillin-tazobactam). The frequency of success without modification of the empirical therapy was nearly identical for cefepime plus amikacin (49%) compared with piperacillin-tazobactam plus amikacin (51%). Similar rates of success were found for microbiologically documented infection: 40% versus 39%, respectively. Antibiotic modification was necessary in 49% of cefepime and 44% of piperacillin-tazobactam patients. The overall response rate, with or without modification of the assigned treatment, was 94% in both groups. Drug-related adverse events were reported in 10% of cefepime plus amikacin versus 11% of piperacillin-tazobactam plus amikacin patients. Mortality due to infection occurred in a total of 10 patients (two cefepime, eight piperacillin-tazobactam).

CONCLUSION

The empirical regimen of cefepime plus amikacin is equivalent to piperacillin-tazobactam plus amikacin in febrile adult haematology patients with severe neutropenia.

KEYWORDS

cefepime, piperacillin-tazobactam, amikacin, empirical antibiotic therapy, febrile neutropenia, haematological malignancy

[Infection in patients with neutropenia that undergo an autologous peripheral blood stem cell transplant due to breast cancer]

BACKGROUND

The extent and duration of neutropenia and the characteristics of the underlying disease are determinant factors for the prognosis of febrile syndromes. Despite the fact that traditionally the peripheral blood stem cell transplantation (PBSCT) were considered to cause high risk neutropenia, in all probability the neutropenia observed in the PBSCT in some solid tumours could be considered moderate risk. Febrile episodes in patients with these characteristics were evaluated.

METHODS

We prospectively analysed 132 autologus PBSCT in patients with breast cancer (1994-1999). Conditioning regime: STAMP V. Antibacterial prophylaxis: ofloxacin (400 mg/12 hrs PO). Classification of the febrile syndrome: bacteremia, microbiologically documented infection withut bacteremia, clinical infection and a fever of unknown origin.

RESULTS

122 patients had a fever (92%), mean age: 45 years (range: 27-61). There were 32 (26%) bacteremias, 13 (11%) microbiologically documented infections without bacteremia and 54 (44%) clinical infections. The mean number of days with a neutrophil count of <1x109/1 was 14 (range: 11-20). In the 74 patients (61%) that had a granulocyte colony stimulating factor (G-CSF), the mean number of days to reach a 0,5x109/I neutrophil count (7,6) and the average number of days in hospital (26) were significantly less. There was a main infectious point in 80 patients (65%): the most frequent being oropharynx in 33 cases (46%) and digestive in 29 cases (41%). 48 gram negative (GN) 29 gram positive (GP) bacteria were isolated (71% of the GN's were resistant to ofloxacin). Between 1997-1999 the GN/GP ratio was 2,3. There were no deaths related to the infection.

CONCLUSIONS

Given the excellent evolution of our patients we can consider their neutropenia to be moderate or low risk, and they are a long way from the death rates caused by infections published by other types of hemopoietic transplants. The predominance of GN over the last few years and their limited sensitivity to quinolones means that their prophylactic use in these patients should be reconsidered.

Molecular mimicry of substrate oxygen atoms by water molecules in the beta-amylase active site

Soybean beta-amylase (EC 3.2.1.2) has been crystallized both free and complexed with a variety of ligands. Four water molecules in the free-enzyme catalytic cleft form a multihydrogen-bond network with eight strategic residues involved in enzyme-ligand hydrogen bonds. We show here that the positions of these four water molecules are coincident with the positions of four potential oxygen atoms of the ligands within the complex. Some of these waters are displaced from the active site when the ligands bind to the enzyme. How many are displaced depends on the shape of the ligand. This means that when one of the four positions is not occupied by a ligand oxygen atom, the corresponding water remains. We studied the functional/structural role of these four waters and conclude that their presence means that the conformation of the eight side chains is fixed in all situations (free or complexed enzyme) and preserved from unwanted or forbidden conformational changes that could hamper the catalytic mechanism. The water structure at the active pocket of beta-amylase is therefore essential for providing the ligand recognition process with plasticity. It does not affect the protein active-site geometry and preserves the overall hydrogen-bonding network, irrespective of which ligand is bound to the enzyme. We also investigated whether other enzymes showed a similar role for water. Finally, we discuss the potential use of these results for predicting whether water molecules can mimic ligand atoms in the active center.

Evolution of alpha-amylases: architectural features and key residues in the stabilization of the (beta/alpha)(8) scaffold

We provide a comprehensive analysis of the current enzymes with alpha-amylase activity (AAMYs) that belong to family 13 glycoside hydrolase (GH-13; 144 Archaea, Bacteria, and Eukaryota sequences from 87 different species). This study aims to further knowledge of the evolutionary molecular relationships among the sequences of their A and B domains with special emphasis on the correlation between what is observed in the structures and protein evolution. Multialignments for the A domain distinguish two clusters for sequences from Archaea organisms, eight for sequences from Bacteria organisms, and three for sequences from Eukaryota organisms. The clusters for Bacteria do not follow any strict taxonomic pathway; in fact, they are rather scattered. When we compared the A domains of sequences belonging to different kingdoms, we found that various pairs of clusters were significantly similar. Using either sequence similarity with crystallized structures or secondary-structure prediction methods, we identified in all AAMYs the eight putative beta-strands that constitute the beta-sheet in the TIM barrel of the A domain and studied the packing in its interior. We also discovered a "hidden homology" in the TIM barrel, an invariant Gly located upstream in the sequence before the conserved Asp in beta-strand 3. This Gly precedes an alpha-helix and is actively involved in capping its N-terminal end with a capping box. In all cases, a Schellman motif caps the C-terminal end of this helix.

Horizontal gene transfer in bacterial and archaeal complete genomes

There is growing evidence that horizontal gene transfer is a potent evolutionary force in prokaryotes, although exactly how potent is not known. We have developed a statistical procedure for predicting whether genes of a complete genome have been acquired by horizontal gene transfer. It is based on the analysis of G+C contents, codon usage, amino acid usage, and gene position. When we applied this procedure to 17 bacterial complete genomes and seven archaeal ones, we found that the percentage of horizontally transferred genes varied from 1.5% to 14.5%. Archaea and nonpathogenic bacteria had the highest percentages and pathogenic bacteria, except for Mycoplasma genitalium, had the lowest. As reported in the literature, we found that informational genes were less likely to be transferred than operational genes. Most of the horizontally transferred genes were only present in one or two lineages. Some of these transferred genes include genes that form part of prophages, pathogenecity islands, transposases, integrases, recombinases, genes present only in one of the two Helicobacter pylori strains, and regions of genes functionally related. All of these findings support the important role of horizontal gene transfer in the molecular evolution of microorganisms and speciation.

[Cost of antibiotic therapy in neutropenic patients undergoing peripheral blood stem cell transplantation for breast cancer]

The increase in pharmaceutical costs, especially for expensive procedures such as bone marrow transplants, has led to the study of the economic impact of febrile neutropenia in peripheral blood stem cell transplantation (PBSCT). We analyzed 89 consecutive patients with breast cancer who underwent PBSCT. All patients developed febrile neutropenia and were administered an empirical intravenous regimen based on the combination of piperacillin-tazobactam and amikacin. We analyzed the direct costs of this treatment and grouped them into drug acquisition cost, administration costs (cost of the additional material), and preparation costs (time employed for the preparation and administration of the drug). We found that the overall cost was $1,110, 65% of which corresponded to the initial therapy and the rest (35%) to the use of additional antibiotics. This higher cost was especially related to the use of vancomycin or teicoplanin (50%). The acquisition costs accounted for 90% of the overall treatment costs. Thirty-six patients (40%) did not need additional antibiotics and the cost in this group was less ($663). We concluded that knowledge of the costs of pharmacological therapy for infection in PBSCT is indispensable for the appropriate development of treatment units, especially in terms of optimizing resources and comparing different therapeutic or prophylactic approaches.

Horizontal gene transfer of glycosyl hydrolases of the rumen fungi

By combining analyses of G + C content and patterns of codon usage and constructing phylogenetic trees, we describe the gene transfer of an endoglucanase (celA) from the rumen bacteria Fibrobacter succinogenes to the rumen fungi Orpinomyces joyonii. The strong similarity between different glycosyl hydrolases of rumen fungi and bacteria suggests that most, if not all, of the glycosyl hydrolases of rumen fungi that play an important role in the degradation of cellulose and other plant polysaccharides were acquired by horizontal gene transfer events. This acquisition allows fungi to establish a habitat within a new environmental niche: the rumen of the herbivorous mammals for which cellulose and plant hemicellulose constitute the main raw nutritive substrate.

Horizontal gene transfer in glycosyl hydrolases inferred from codon usage in Escherichia coli and Bacillus subtilis

Glycosyl hydrolase (GH) genes from Escherichia coli and Bacillus subtilis were used to search for cases of horizontal gene transfer. Such an event was inferred by G + C content, codon usage analysis, and a phylogenetic congruency test. The codon usage analysis used is a procedure based on a distance derived from a Pearson linear correlation coefficient determined from a pairwise codon usage comparison. The distances are then used to generate a distance-based tree with which we can define clusters and rapidly compare codon usage. Three genes (yagH from E. coli and xynA and xynB from B. subtilis) were determined to have arrived by horizontal gene transfer and were located in E. coli CP4-6 prophage, and B. subtilis prophages 6 and 5, respectively. In this study, we demonstrate that with codon usage analysis, the proposed horizontally transferred genes can be distinguished from highly expressed genes.

IMASIS. A multicenter hospital information system--experience in Barcelona

The present study aimed to analyse physicians' attitudes towards IMASIS, and their potential influence on IMASIS medical record project. IMAS (Institut Municipal d'Assistència Sanitària) is the health care organisation of the City Council of Barcelona. IMAS hospital information system (IMASIS), which first applications were designed and implemented in 1984, is currently facing a new phase, focused on clinical information management. Our approach included a personal interview with representatives of every hospital unit, and a self-administered questionnaire distributed to every clinician. Both provided a worthy insight into the cultural patterns to be considered in the HIS implementation process. Moreover, the results helped to define the subsequent steps of IMASIS evolution. Our experience is proposed as a tool to assess clinical informations systems from a user point of view.

Structural features of single amino acid repeats in proteins

Single amino acid repeats are found in different kinds of proteins. Some of these repeats are pathogenic. It is striking that some amino acids are able to form such repeats, but other amino acids are not. We suggest an explanation for this fact based on the different tendency of each amino acid to form aggregates. Aggregation may be due to the formation of incipient lamellar crystals as they have been described in poly-alpha-amino acids and in most synthetic polymers.

DNA-interacting proteins in the spermiogenesis of the mollusc Murex brandaris

Sperm chromatin of Murex brandaris (a neogastropod mollusc) undergoes a series of structural transitions during spermiogenesis. The DNA-interacting proteins responsible for these changes as well as the mature protamines present in the ripe sperm nucleus have been characterized. The results reveal that spermiogenic nuclear proteins are protamine precursors that are subjected to a substantial number of small N-terminal deletions that gradually modify their overall charge. The composition of mature protamines is remarkably simple in turn, promoting an efficient and extremely tight packaging of DNA. The pattern of spermiogenic chromatin condensation in M. brandaris clearly departs from that corresponding to vertebrate chromatin.

Nuclear receptors, nuclear-receptor factors, and nuclear-receptor-like orphans form a large paralog cluster in Homo sapiens

We studied a human protein paralog cluster formed by 38 nonredundant sequences taken from the Swiss-Prot database and its supplement, TrEMBL. These sequences include nuclear receptors, nuclear-receptor factors and nuclear-receptor-like orphans. Working separately with both the central cysteine-rich DNA-binding domain and the carboxy-terminal ligand-binding domain, we performed multialignment analyses that included drawings of paralog trees. Our results show that the cluster is highly multibranched, with considerable differences in the amino acid sequence in the ligand-binding domain (LBD), and 17 proximal subbranches which are identifiable and fully coincident when independent trees from both domains are compared. We identified the six recently proposed subfamilies as groups of neighboring clusters in the LBD paralog tree. We found similarities of 80%-100% for the N-terminal transactivation domain among mammalian ortholog receptors, as well as some paralog resemblances within diverse subbranches. Our studies suggest that during the evolutionary process, the three domains were assembled in a modular fashion with a nonshuffled modular fusion of the LBD. We used the EMBL server PredictProtein to make secondary-structure predictions for all 38 LBD subsequences. Amino acid residues in the multialigned homologous domains--taking the beginning of helix H3 of the human retinoic acid receptor-gamma as the initial point of reference--were substituted with H or E, which identify residues predicted to be helical or extended, respectively. The result was a secondary structure multialignment with the surprising feature that the prediction follows a canonical pattern of alignable alpha-helices with some short extended elements in between, despite the fact that a number of subsequences resemble each other by less than 25% in terms of the similarity index. We also identified the presence of a binary patterning in all of the predicted helices that were conserved throughout the 38-sequence sample. Our results fit well with a recently proposed evolutionary model that combines protein secondary structure and amino acid replacement. We propose a new hypothesis for molecular evolution, in which chaperones--acting as an endogenous cellular device for selection--play a crucial role in preserving protein secondary structure.

Deciphering the structural code for proteins: helical propensities in domain classes and statistical multiresidue information in alpha-helices

We made several statistical analyses in a large sample of nearly 4,000 helices (from 546 redundancy-controlled PDB protein subunits), which give new insights into the helical properties of globular proteins. In a first experiment, the amino acid composition of the whole sample was compared with the composition of two helical sample subgroups (the "mainly-alpha" and the "(alpha/beta)8 barrel" domain classes); we reached the conclusion that composition-based helical propensities for secondary structure prediction do not depend on the structural class. Running a five-residue window through the whole sample, the positional composition revealed that positive and negative residues are located throughout the helices and tend to neutralize the macrodipole effect. On this basis, we analyzed charged triplets using a running five-residue window. The conclusion was that only mixed charged residues [positive (+) and negative (-)] located at positions 1-2-5 and 1-4-5 are clearly favored. In these locations the most abundant are (- -..+) and (-..+ +), and this shows the existence of side chain microdipoles, which neutralize the large macrodipole of the helix. We made a systematic statistical analysis of charged, dipolar, and hydrophobic + aromatic residues, which enabled us to work out rules that should be useful for modeling and design purposes. Finally, we analyzed the relative abundance of all the different amphipathic double-arcs that are present in helices formed by octapeptides (8) and nonapeptides (18). All of the double-arcs that make up Schiffer and Edmundson's classical helical wheel are found in abundance in the sample.

Circular permutants in beta-glucosidases (family 3) within a predicted double-domain topology that includes a (beta/alpha)8-barrel

By predicting the general secondary structure for beta-glucosidases (family 3), in conjunction with existing knowledge of the circular permutants present in B. fibrisolvens and R. albus, we were able to find the canonical elements of the secondary structure. The way these elements are linked suggests that there is a double-domain topology made up of a (beta/alpha)8-barrel domain and a "mainly all-beta" domain. A number of already known conserved motifs are located within (or near) the C-terminal part of the putative parallel beta-strands of the (bet/alpha)8-barrel, which is consistent with what is known about the location of catalytical sites for enzymes that have this domain topology. Within the circular permutants, two beta/alpha units are located at the N-terminal part of the molecule, whereas the other six beta/alpha units are located at the C-terminal end. In this way, the circular permutants can be seen to have a putative discontinuous double-domain topology.

The antiemetic efficacy of granisetron plus dexamethasone, haloperidol and loracepam in breast cancer patients treated with high-dose chemotherapy with peripheral blood stem-cell support

There has recently been a marked trend to increasing dose intensity in cancer chemotherapy, with or without peripheral blood stem-cell support, which has been associated with a higher frequency of nausea and vomiting. Antiemetic treatment in this setting has not been extensively analysed. From October 1995 to January 1997, prevention of emesis with granisetron 3 mg/12 h i.v., dexamethasone 12 mg/24 h i.v., haloperidol 0.5 mg/12 h p.o., and loracepam I mg/24 h p.o. was instituted in 30 breast cancer patients treated with high-dose chemotherapy (a 4-day intravenous continuous infusion of cyclophosphamide 1500 mg/m2 per day, thio-TEPA 125 mg/m2 per day and carboplatin 200 mg/m2 per day).A total of 30% of the patients (9/30) obtained complete or major protection on the 4 days of chemotherapy treatment (96.7% (29/30) on day 1, 86.7% (26/30) on day 2, 70% (21/30) on day 3, and 50% (15/30) on day 4). On the days following chemotherapy, 46.7% (14/30) presented fewer than two emetic episodes on day 5, 70% (21/30) on day 6, 83.4% (25/30) on day 7 and, 93.3% (28/30) on day 8. This energic antiemetic combination treatment has hardly any effect in the prevention of emesis, providing complete or major protection of 30% for the 4 days of chemotherapy treatment. Further investigation aimed at improving antiemetic treatment results is necessary.

[Invasive fungal infections in patients with blood disorders]

BACKGROUND

Invasive fungal infections (IFI) are severe infectious complications frequently observed in patients with hematological disorders. The aims of this study were to analyse the characteristics of this particular type of infection in a large series of a single institution and to determine the factors associated with the outcome and therapeutic response.

PATIENTS AND METHODS

This study reviews the clinical and microbiological features of 155 IFI occurred among 144 patients with hematologic disorders throughout a period of 17 years in a single institution.

RESULTS

In 118 cases (82%) the diagnosis was acute leukemia. The main risk factors for developing IFI included a persistent and profound granulocytopenia, the use of broad-spectrum antibacterial agents, indwelling central venous catheters and the damage of normal host barriers following intensive cytotoxic chemotherapy. Candida (65 cases [44%]) and Aspergillus (38 cases [26%]) species were the most common fungal species isolated. An increasing number of IFI were caused by fungi previously considered as contaminants or harmless colonizers. The outcome of IFI was favourable in 78 cases (50%). The most important prognostic factors for the outcome of the IFI were the phase of cytotoxic chemotherapy (p = 0.005), the response of the underlying disease to the cytotoxic chemotherapy (p < 0.00001), and the recovery of neutropenia during the infection course (p < 0.00001). An earlier use of empirical antifungal therapy was also associated with a better outcome.

CONCLUSIONS

In spite of earlier treatment and regardless the development of new antifungal agents, the prognosis of IFI in patients with hematological malignancies remains poor. The use of hematopoietic growth factors, through their impact in the duration and severity of neutropenia, may prove valuable the management of IFI in this setting.

Anatomy of a conformational transition of beta-strand 6 in soybean beta-amylase caused by substrate (or inhibitor) binding to the catalytical site

A computational study of the five soybean beta-amylase X-ray structure reported so far revealed a peculiar conformational transition after substrate (or inhibitor) binding, which affects a segment of the beta-strand 6 (residues 341-343) in the (beta/alpha)8 molecular scaffold. Backbone distortions that involve considerable changes in the phi and psi angles were observed, as well as two sharp rotamer transitions for the Thr342 and Cys343 side chains. These changes caused the outermost CA-layer (at the C-terminal side of the barrel), which is involved in the catalysis, to shrink. Our observations strongly suggest that the 341FTC343 residue conformations in the free enzyme are not optimal for protein stability. Furthermore, as a result of conformational transitions in the ligand-binding process, there is a negative enthalpy change for these residues (-27 and -34 kcal/mol, after substrate or inhibitor binding, respectively). These findings support the proposed "stability-function" hypothesis for proteins that recognize a ligand (Shoichet BK, Baase WA, Kuroki R, Matthews BW. 1995. A relationship between protein stability and protein function. Proc Natl Acad Sci USA 92:452-456). They are also in good agreement with other experimental results in the literature that describe the role of the 341-343 segment in beta-amylase activity. Site-directed mutagenesis focused on these residues could be useful for undertaking functional studies of beta-amylase.

[Levels of cytokeratin CK19 expression in mononuclear blood cells evaluated using a reverse PCR (RT-PCR)]

AIMS

The sensitivity and specificity of a reverse transcription PCR method (RT-PCR) to detect cytokeratin K19 (CK19) expression was evaluated with the purpose of assessing its capability to detect the presence of breast cancer tumour cells in peripheral blood progenitor cell collection that had to be reinfused to breast cancer patients submitted to intensive chemotherapy as haematopoietic support.

PATIENTS AND METHODS

Two breast cancers as positive samples were used and 34 samples of mononucleated blood cells as negative controls: 18 peripheral blood samples from normal subjects, 14 from different types of leukaemias (M3, M4Eo, M2, etc.) and two from two patients with Hodgkin's lymphoma. The method studied is a nested RT-PCR that amplifies the CK19 expression from the sample RNA extracted following the method of phenol-chloroform.

RESULTS

The right performance of the method is demonstrated by observing the detection of CK19 transcripts in the breast cancer RNA and by obtaining good blank results both with non transcribed RNA and with DNA. Moreover, the method has an excellent sensitivity such as to allow the detection of CK19 transcripts in a 10(-6) dilution of cDNA reverse transcribed from 1 microgram of breast cancer RNA. The CK19 transcripts were also detected in the 64% of RNA obtained from the mononucleated blood cells controls, although the percentage of positivities was lower (47%) in the RNA from peripheral blood samples. Nevertheless it should be remarked that the levels of CK19 expression in the blood mononucleated cells is almost negligible since it used to extinguish at 1:5 cDNA dilution.

CONCLUSIONS

The method studied is specific and has a high sensitivity that explains the detection of CK19 illegitimate expression approximately a half in mononucleated blood cells negative controls. However, the levels of CK19 expression in mononucleated blood cells were almost negligible and it used to extinguish at 1:5 cDNA dilution, therefore it could be concluded that the method might be useful to detect breast cancer occult tumours cells in mononucleated blood cell collection, always provided that a lower amount of cDNA is taken, thus decreasing to nil almost the false positive samples and keeping always a good sensitivity.

Evolution of beta-amylase: patterns of variation and conservation in subfamily sequences in relation to parsimony mechanisms

Soybean and sweet potato beta-amylases are structured as alpha/beta barrels and the same kind of folding may account for all known beta-amylases. We provide a comprehensive analysis of both protein and DNA (coding region) sequences of beta-amylases. The aim of the study is to contribute to the knowledge of the evolutionary molecular relationships among all known beta-amylases. Our approach combines the identification of the putative eightfold structural core formed by beta-strands with a complete multi-alignment analysis of all known sequences. Comparing putative beta-amylase (alpha/beta)8 cores from plants and microorganisms, two differentiated versions of residues at the packing sites, and a unique set of eight identical residues at the C-terminal catalytical site are observed, indicating early evolutionary divergence and absence of localized three-dimensional evolution, respectively. A new analytical approach has been developed in order to work out conserved motifs for beta-amylases, mostly related with the enzyme activity. This approach appears useful as a new routine to find sets of motifs (each set being known as a fingerprint) in protein families. We demonstrate that the evolutionary mechanism for beta-amylases is a combination of parsimonious divergence at three distinguishable rates in relation to the functional signatures, the barrel scaffold, and alpha-helix-containing loops.

Narrow A/T-rich zones present at the distal 5'-flanking sequences of the zein genes Zc1 and Zc2 bind a unique 30 kDa HMG-like protein

Nuclear extracts from maize endosperm were used to investigate protein-DNA interactions in the 5'-upstream region of the Zc1 and Zc2 genes. These genes encode for zeins of apparent molecular mass (MWapp) 16 and 28 kDa, respectively, which accumulate in the endosperm during seed maturation. Binding assays revealed specific binding of a nuclear protein to three A/T-rich elements, 0.9-1.0 kbp upstream from the initiation codon. One of these elements (41 bp, 88% A/T), present in Zc1, contained a 13 nucleotide duplication. The other two (28 bp, 86% A/T; 42 bp alternating A-T) are consecutive elements in Zc2. Competition experiments strongly suggest that the three elements bind to the same protein. Protein-DNA interaction was detected in endosperm nuclear extracts of 8 to 21 days after pollination (DAP), as well as in 25 DAP embryos and in different tissues from plantlets. The protein factor has an MWapp of ca. 30 kDa. This factor has properties suggesting it is an HMG-like protein. These results are consistent with a growing accumulation of data for a number of genes indicating that A/T-rich elements, located at distal and proximal zones of the 5'-flanking sequences, interact with HMG-like proteins.

Rapid progression of multiple myeloma following G-CSF mobilization

A 23-year-old man diagnosed as having multiple myeloma was treated with melphalan and prednisone monthly. After six cycles, an autologous peripheral blood stem cell transplantation (ABSCT) was planned. Peripheral blood mononuclear cells were collected after G-CSF mobilization (5 micrograms/kg/day for 5 days). Ten days after the last dose of G-CSF the patient showed a striking progression of multiple myeloma. A 57% infiltration of plasma cells in bone marrow and recurrence of laboratory abnormalities were evident. The patient's clinical course strongly suggests that myeloma progression was triggered by G-CSF and supports the concept of G-CSF mediated autocrine stimulation of myeloma growth.

[Results of endoscopic dilatation treatment of benign esophageal stenosis]

The management of benign esophageal stenoses is based on endoscopic dilatation of the tight segment for the remission of dysphagia. Five hundred and twenty sessions of dilatation with Savary-Guilliard bougies have been performed in one hundred and twenty-nine patients with benign esophageal stenoses. Patients with peptic stenoses (n = 59) needed a lesser number of sessions (mean: 2.47) than patients with postsurgical (n = 44; mean: 4.86) or caustic (n = 18; mean: 7.77) stenoses. The treatment failed in 4 patients (3.2%) and severe complications were observed in 3 patients (2.4%). These results support the efficacy and safety of this technique.

Acute myeloblastic leukemia with minimal myeloid differentiation (FAB AML-M0): a study of eleven cases

The main clinical, morphological, cytochemical, immunological features and therapy results of eleven patients diagnosed as acute myeloblastic leukemia M0 (AML-M0) are reported here. There were no clinical characteristics, abnormalities on physical examination or initial laboratory parameters that distinguished these eleven patients. Bone marrow aspirates were hypocellular in four patients. The leukemic cells were undifferentiated by light microscopy and myeloperoxidase (MPO) and/or Sudan Black B (SBB) stains were negative in all cases. Myeloid differentiation antigens were present on the leukemic cells of all eleven patients, whereas B and T cell markers were clearly negative except for CD4 and CD7 antigens. Whatever the treatment employed survival was very short. Eight of the eleven patients were treated and two achieved complete remission (CR) but only one of them is alive in continuous CR. Our results like those previously reported, suggest that AML-M0 patients have a very poor prognosis with standard induction therapies and should perhaps be considered for experimental therapeutic approaches.