Emerging Hyalomma lusitanicum: From identification to vectorial role and integrated control

In the Mediterranean basin, the tick species Hyalomma lusitanicum Koch stands out among other species of the Hyalomma genus due to its wide distribution, and there is great concern about its potential role as a vector and/or reservoir and its continuous expansion to new areas because of climate warming and human and other animal movements. This review aims to consolidate all the information on H. lusitanicum, including taxonomy and evolution, morphological and molecular identification, life cycle, sampling methods, rearing under laboratory conditions, ecology, hosts, geographical distribution, seasonality, vector role and control methods. The availability of adequate data is extremely relevant to the development of appropriate control strategies in areas where this tick is currently distributed as well as in new areas where it could become established in the near future.

Invariant representations in deep learning for optoacoustic imaging

Image reconstruction in optoacoustic tomography (OAT) is a trending learning task highly dependent on measured physical magnitudes present at sensing time. A large number of different settings and also the presence of uncertainties or partial knowledge of parameters can lead to reconstruction algorithms that are specifically tailored and designed to a particular configuration, which could not be the one that will ultimately be faced in a final practical situation. Being able to learn reconstruction algorithms that are robust to different environments (e.g., the different OAT image reconstruction settings) or invariant to such environments is highly valuable because it allows us to focus on what truly matters for the application at hand and discard what are considered spurious features. In this work, we explore the use of deep learning algorithms based on learning invariant and robust representations for the OAT inverse problem. In particular, we consider the application of the ANDMask scheme due to its easy adaptation to the OAT problem. Numerical experiments are conducted showing that when out-of-distribution generalization (against variations in parameters such as the location of the sensors) is imposed, there is no degradation of the performance and, in some cases, it is even possible to achieve improvements with respect to standard deep learning approaches where invariance robustness is not explicitly considered.

Surgical treatment for necrotizing enterocolitis: a new score to extreme surveillance

BACKGROUND

The time to perform a surgical intervention in necrotizing enterocolitis remains a challenge for the pediatric surgeon. We design a novel score system to predict infants in high risk for the development of surgical necrotizing enterocolitis.

METHODS

A total of 124 consecutively patients diagnosed of NEC at the University Hospital of A Coruña, Spain were included in the study. Associations were analyzed by bivariate and multivariate analysis. We applied multivariate logistic regression modeling to identify factors that could provide accurate risk of surgical NEC. We include not only analytical and radiological parameters or physical examination, but we also analyzed prenatal, sociodemographic, perinatal and peripartum variables that conditioned the presence of predispose factors, which could determine the debut of this entity and in its progression.

RESULTS

Patients requiring surgical treatment have presented an antecedent of respiratory distress (worsening of the ventilatory requirements) in the perinatal period, they present higher values of glycemia at diagnosis of the illness, debut with coagulopathy and have in laboratory findings marked neutrophilia.

CONCLUSIONS

Our score system obtained by combining several parameters could detect infants at risk of developing severe necrotizing enterocolitis improving the morbidity and mortality associated with delay in the surgical treatment.

Factors affecting endoscopic treatment’s failure for primary vesicoureteral reflux in the paediatric population

Objective:

The purpose of this study is to identify which factors could determine endoscopic therapy’s failure in the paediatric patients with primary vesicoureteral reflux (VUR).

Methods:

We reviewed data from patients who underwent endoscopic surgery for primary reflux. We performed a multivariate logistic regression analysis considering factors conditioning therapeutic failure. All the tests were performed considering significant values of p < 0.05. Statistical analysis was performed with the SPSS 19.0 program. Study sample was homogenised by just including patients with primary reflux and excluding both patients with secondary reflux and patients with functional lower urinary conditions.

Results:

A total of 96 patients were included for review. Median age at surgery was 28 months. The overall success rate of endoscopic surgery for vesicoureteral reflux was 57%. Female sex, age under 24 months at the time of surgical intervention and having suffered a urinary tract infection (UTI) despite antibiotic prophylaxis are statistically significant risk factors for therapy failure.

Conclusions:

Nonetheless, differences between series could explain these differences in success rates. The lack of standardisation of the definition of ‘success’, the heterogeneity of patients included, and variables such as the degree of reflux, the presence of dysfunctional voiding, age or follow-up make it difficult to compare the success rate between series. Therefore, homogenisation of study samples assessing the evolution of primary reflux and response to endoscopic therapy is warranted.

Level of evidence:

Not applicable

On the robustness of model-based algorithms for photoacoustic tomography: Comparison between time and frequency domains

For photoacoustic image reconstruction, certain parameters such as sensor positions and speed of sound have a major impact on the reconstruction process and must be carefully determined before data acquisition. Uncertainties in these parameters can lead to errors produced by a modeling mismatch, hindering the reconstruction process and severely affecting the resulting image quality. Therefore, in this work, we study how modeling errors arising from uncertainty in sensor locations affect the images obtained by matrix model-based reconstruction algorithms based on time domain and frequency domain models of the photoacoustic problem. The effects on the reconstruction performance with respect to the uncertainty in the knowledge of the sensors location are compared and analyzed both in a qualitative and quantitative fashion for both time and frequency models. Ultimately, our study shows that the frequency domain approach is more sensitive to this kind of modeling errors. These conclusions are supported by numerical experiments and a theoretical sensitivity analysis of the mathematical operator for the direct problem.

Transcutaneous sacral electrical stimulation versus oxibutynin for the treatment of overactive bladder in children

BACKGROUND

Nowadays there is still no ideal treatment for paediatric overactive bladder. Initial management measures (urotherapy and constipation control), resolve 40% of cases. The second line of treatment in overactive bladder is anticholinergic drugs, above all oxybutynin. Although most patients improve with these therapies, the complete resolution rate is around 30-40%. Sacral transcutaneous electrical nerve stimulation has recently emerged as a new alternative in the management of patients with refractory paediatric overactive bladder. However, only a few studies have been done to compare the effectiveness of this therapy versus conventional drugs.

OBJETIVE

The objective of the present study is to compare, in children with overactive bladder, the efficacy of the sacral transcutaneous electrical nerve stimulation versus oxybutynin therapy.

MATERIALS AND METHODS

We performed a prospective and randomized study of patients with diagnosis of overactive bladder treated with sacral transcutaneous electrical nerve stimulation versus oxybutynin, during the period July 2018-July 2020. Patients refractory to standard urotherapy and constipation management randomly received one of the therapeutic alternatives. Treatment was maintained for 6 months.

RESULTS

86 patients were included in the study: 40 patients received electrotherapy (group 1) and 46 patients received oxybutynin (group 2). Before starting the treatment assigned both groups were comparable related to the voiding symptomatology as well as the severity of the overactive bladder. Sacral transcutaneous electrical nerve stimulation was significantly more effective than oxybutynin, with a higher percentage of complete resolution of symptoms in the management of paediatric overactive bladder.

VOIDING DIARY

All the parameters obtained with the voiding calendar significantly improved in both groups at the end of the treatment. The increase in MaVV was significantly higher in group-1.

DVISS (DYSFUNCTIONAL VOIDING AND INCONTINENCE SCORING SYSTEM)

We observed a progressive decrease in the mean score obtained in the DVISS questionnaire over time in both groups. This decrease was significantly higher in group-1 compared to group-2 (p < 0.005). The mean value obtained in the DVISS questionnaire in group-1 was 6 (interquartile range: 3-9) at the end of the treatment (lower than the diagnostic cut-off point for daytime condition in the DVISS, 8.5). In group-2, the mean value obtained in the DVISS questionnaire was 10 (interquartile range: 8.75-13.25), higher than the cut-off point.

COMPLICATIONS

A greater number of adverse effects was obtained in group-2 (26.1% versus 15%, p < 0.05). Constipation (n: 6, 10.9%), and abdominal pain (n: 2,4.3%) were the most frequent adverse effects in this group. The adverse events reported in group-1 were contact dermatitis (n: 1.2%) and fecal losses [2] or urgency [5].

CONCLUSION

Oxybutynin and sacral transcutaneous electrical nerve stimulation are both effective therapies in the management of paediatric overactive bladder. However, electrotherapy has been shown to be a more effective therapy with a complete clinical resolution rate in a larger number of patients. Furthermore, the rate of adverse effects secondary to electrotherapy is significantly lower than those treated with oxybutynin.

[Commentary on Symptoms severity profile and expectations in hyperactive bladder patients. VHEXPECTA Study.]

Estimado Editor: Escribimos esta carta en relación al artículo publicado en su revista el pasado mes de Julio de 2020, por Castro-Díaz et al., titulado "Perfil de severidad sintomática y expectativas en pacientes con vejiga hiperactiva. Estudio VHEXPECTA" (1), y que hemos leído con gran interés. A propósito de este trabajo creemos conveniente ampliar la información ofrecida por sus autores, y plantear una serie de consideraciones por nuestra parte.

Update on sacral neuromodulation and overactive bladder in pediatrics: A systematic review

OBJECTIVES

Sacral electrical stimulation has been used for more than a century as an alternative therapy for adult urinary syndromes. In the literature, several studies have validated the efficacy of this technique based on clinical and urodynamic criteria. Nevertheless, few studies have shown beneficial results in children with overactive bladder.

MATERIAL AND METHODS

We performed a systematic review of studies assessing the impact of sacral electroestimulation treatment on overactive bladder in children. The search identified 389 potentially eligible items. Of them, 14 studies published between 2001and 2019 met the study criteria and were selected for systematic review. RESULTS: All of papers included in this review individually demonstrated a high efficiency rate with good shortterm results, as well as safety in its use due to its minimalrate of adverse effects. However, the comparison of the results obtained in all of them was not possible because the high variety and heterogeneity in the different studies. The main limitation is that there is still no standard protocol for the application of this therapy in the pediatric population.

CONCLUSION

This review revealed the promising benefits of sacral electroneuromodulation in pediatric patients with overactive bladder. However, more studies with strictly meet pediatric overactive bladder diagnosis and management criteria should be done to protocolize and clarify the effectiveness of this therapeutic approach.

Seasonal Dynamics of Fleas (Siphonaptera: Pulicidae, Ceratophyllidae and Leptopsyllidae) on Oryctolagus cuniculus in a Meso-Mediterranean Area of Central Spain

Flea infestations of wild rabbits were examined monthly in central Spain in a meso-Mediterranean area for 5 yr. A total of 1,180 wild rabbits were trapped and 7,022 fleas were collected from them. Overall, the prevalence was 74.1% with a mean flea index of 5.95 fleas per rabbit. Four flea species were identified: Spilopsyllus cuniculi (Dale, 1878) was the most abundant species (accounting for 74.3% of fleas collected) followed by Xenopsylla cunicularis (Smit, 1957), Odontopsyllus quirosi (Gil Collado, 1934), and Nosopsyllus fasciatus (Bosc, 1800) (18.9, 6.7, and 0.1%, respectively). The highest prevalence was observed in S. cuniculi (48.6%) followed by X. cunicularis, O. quirosi, and N. fasciatus (34.3, 20.0, and 0.6%, respectively). Odontopsyllus quirosi and S. cuniculi were mainly collected from autumn to spring with the peak of infestation in winter, while X. cunicularis was mainly found from spring to autumn with maximum levels of infestation during the summer months. The relevance of these findings is discussed.

A method for the calibration of wideband ultrasonic sensors for optoacoustics

A method for calibration of ultrasonic sensors for optoacoustics that provides both frequency response and sensitivity is presented. In order to obtain the bandwidth and the frequency response of an uncalibrated sensor, a point source with broadband spectra generated by a laser-induced bubble on a copper wire submerged in water is employed. On the other hand, the sensitivity measurement relies on the spatial symmetry of the pressure pulse and on a calibrated transducer. Therefore, two sensors are employed to detect the pressure pulse at the same distance from the source. The symmetry of the acoustic field that arrives at both transducers is adjusted and verified by means of an optical interferometer that provides a null signal when the copper wire is placed at the right position. The method is tested on the characterization of a thin-film polymeric piezoelectric transducer with a cylindrical focused shape.

Dermal regeneration sheet Integra® in management of recurrent Urethrocutaneous fistula after hypospadias surgery

BACKGROUND

Urethrocutaneous fistula UCF is the most common complication following surgical repair of hypospadias. Currently, the surgical technique mostly used to prevent recurrence employs preputial dartos or testicular tunica vaginalis flaps as a urethral covering. However, autologous tissues are limited in patients with multiple surgeries, and the use of biomaterials as a urethral coverage may represent a good alternative.

OBJECTIVE

The goal of the present study is to assess the results and complications of recurrent UCF correction using a dermal bovine regeneration sheet as a urethral covering.

MATERIALS AND METHOD

From May 2016 to January 2019, all patients with recurrent UCF of the authors center were repaired using this technique. The inclusion criteria were patients who had undergone one or more unsuccessful UCF repair surgeries and the absence of preputial tissue. The informed consent has been signed by all the patients. Patients were examined in outpatient consultations where their urinary stream was evaluated and a physical examination of the penis was conducted.

RESULTS

A total of 12 patients and 13 UCFs were included in the study. The median follow-up was 18 months, (range: 4-26), and only two patients (15%) developed a recurrence of UCF. No complications were observed in the remaining patients (85%) during their evolution. No patient developed a fibrosis increase or loss of elasticity of the tissues in contact with the dermal matrix.

CONCLUSION

The use of an Integra® sheet as a urethral covering during urethral fistula surgery appears to be a safe, effective, and easily reproducible option. However, prospective studies with larger numbers of patients should be performed to corroborate these results.

Generation of sub-microsecond quasi-unipolar pressure pulses

We present a method to generate sub-microsecond quasi-unipolar pressure pulses. Our approach is based on the laser irradiation of a thin copper wire submerged in water. The acoustic waveforms were recorded using two different, well characterized, wideband detection techniques: piezoelectric and optical interferometry. The results show that the irradiated target behaves as an omnidirectional source. Moreover, the peak pulse pressure linearly depends on the laser fluence and the source size. From the results, we propose an empirical equation for the spatial and temporal profile of the pressure pulse. The method has several advantages: ease of implementation, high repeatability, wide ultrasonic bandwidth and quasi-unipolar time profile. These features lead to potential applications of this acoustic source in ultrasonic characterization such as transducer systems, materials or passive devices.

[Integra™ artificial sheet as urethral covering during surgery for hypospadias sequel.]

Estimado Editor: Escribimos esta carta en relación al artículo publicado en su revista el pasado mes de Diciembre de 2017, por Tardáguila Calvo et al., titulado "Reconstrucción genital con dermis artificial Integra® tras resección radical en un niño con linfangiomatosis difusa" (1), y que hemos leído con gran interés. A propósito de este trabajo creemos conveniente ampliar la información de los autores compartiendo nuestra experiencia previa (2,3).

Atypical presentation of Leydig cell tumour in three prepubertal patients: diagnosis, treatment and outcomes

Background Testicular tumours are uncommon in children, accounting for only 1% of all childhood tumours. Prepubertal Leydig cell tumours actively secrete testosterone and as a result, patients typically present with isosexual precocious pseudopuberty, this being the first cause of consultation. We present three cases of Leydig cell tumours in prepubertal patients with an atypical presentation. Methods We studied three cases of Leydig cell tumours in prepubertal boys, who either consulted for testicular asymmetry or were incidentally found to have the tumour in the absence of systemic signs of systemic hyperandrogenism or precocious puberty. In all cases, a well-circumscribed testicular mass was found by testicular ultrasound. The diagnosis was confirmed by histology. In all three cases, testicular enucleation was performed with satisfactory follow-up. Results Following the surgical procedure, during the follow-up, all patients showed a normal testicular volume in comparison with the contralateral testis. No complications were seen during follow-up. Conclusions A testicular ultrasound in children developing asymptomatic testicular asymmetry might be recommended due to its possible hormonal action locally. An early testicular ultrasound, testicular swelling discrepancies, tumour size and androgen production are key factors in the prognosis and management of this type of tumour.

Spirocercosis in red fox (Vulpes vulpes) in a natural reserve located in a meso-Mediterranean area

Spirocerca lupi Rudolphi 1809 (Nematoda Spirocercidae) has an indirect cycle involving intermediate and paratenic hosts, having domestic or wild canids as the main definitive hosts. The most frequent pathology affecting dogs is a granulomatous tumor-like growth containing adults in the oesophagus and aorta. There are very few references about the presence of nodules in the stomach. There is scant information about the epidemiology of this disease in wild red foxes in meso-Mediterranean areas. In this work we report on the natural infection of wild red foxes by Spirocerca lupi and the damage produced in the stomach wall in an area where contact with other potential definitive hosts (canids) is very rare. From July 2015 to November 2016, 61 red foxes were sampled. 18.03% of the stomach walls examined had nodules containing Spirocerca lupi adults and eggs. The prevalence of infection was similar for young and adult groups (23.81 and 18.18%; χ2 = 0.25; df = 1; P = 0.6171) and it was higher in females than in males (25.81 versus 10.00%, χ² = 2.58; df = 1; P = 0.1082). The red fox population in the area seems to be well established judging from their age distribution and the fact that they could be captured all year round. It would appear that in the absence of other main definitive host S. lupi population is able to survive just parasitizing red foxes. Pathologic effects of this parasite on red foxes seems to show some differences related to domestic dogs. These results also indicates as predator control programs can maintain suitable host populations with reduced level of infection.

Parametric modeling of wideband piezoelectric polymer sensors: Design for optoacoustic applications

In this work, we present a three-dimensional model for the design of wideband piezoelectric polymer sensors which includes the geometry and the properties of the transducer materials. The model uses FFT and numerical integration techniques in an explicit, semi-analytical approach. To validate the model, we made electrical and mechanical measurements on homemade sensors for optoacoustic applications. Each device was implemented using a polyvinylidene fluoride thin film piezoelectric polymer with a thickness of 25 μm. The sensors had detection areas in the range between 0.5 mm² and 35 mm² and were excited by acoustic pressure pulses of 5 ns (FWHM) from a source with a diameter around 10 μm. The experimental data obtained from the measurements agree well with the model results. We discuss the relative importance of the sensor design parameters for optoacoustic applications and we provide guidelines for the optimization of devices.

Modeling thin-film piezoelectric polymer ultrasonic sensors

This paper presents a model suitable to design and characterize broadband thin film sensors based on piezoelectric polymers. The aim is to describe adequately the sensor behavior, with a reasonable number of parameters and based on well-known physical equations. The mechanical variables are described by an acoustic transmission line. The electrical behavior is described by the quasi-static approximation, given the large difference between the velocities of propagation of the electrical and mechanical disturbances. The line parameters include the effects of the elastic and electrical properties of the material. The model was validated with measurements of a poly(vinylidene flouride) sensor designed for short-pulse detection. The model variables were calculated from the properties of the polymer at frequencies between 100 Hz and 30 MHz and at temperatures between 283 K and 313 K, a relevant range for applications in biology and medicine. The simulations agree very well with the experimental data, predicting satisfactorily the influence of temperature and the dielectric properties of the polymer on the behavior of the sensor. Conversely, the model allowed the calculation of the material dielectric properties from the measured response of the sensor, with good agreement with the published values.

Stereodynamics of the photodissociation of nitromethane at 193 nm: unravelling the dissociation mechanism

The photodissociation of nitromethane at 193 nm is reviewed in terms of new stereodynamical information provided by the measurement of the first four Dixon's bipolar moments, β0(2)(20), β0(0)(22), β0(2)(02), and β0(2)(22), using slice imaging. The measured speed-dependent β0(2)(20) (directly related with the spatial anisotropy parameter β) indicates that after one-photon absorption to the S3(2 (1)A″) state by an allowed perpendicular transition, two reaction pathways can compete with similar probability, a direct dissociation process yielding ground-state CH3 and NO2(1 (2)A2) radicals and a indirect dissociation through conical intersections in which NO2 radicals are formed in lower-lying electronic states. A particularly important result from our measurements is that the low recoil energy part of the methyl fragment translational energy distribution presents a contribution with parallel character, irrespective of the experimental conditions employed, that we attribute to parent cluster dissociation. Moreover, the positive values found for the β0(0)(22) bipolar moment indicates some propensity for the fragment's recoil velocity and angular momentum vectors to be parallel.

Photodissociation of pyrrole-ammonia clusters below 218 nm: quenching of statistical decomposition pathways under clustering conditions

The excited state hydrogen transfer (ESHT) reaction in pyrrole-ammonia clusters (PyH·(NH(3))(n), n = 2-5) at excitation wavelengths below 218 nm down to 199 nm, has been studied using a combination of velocity map imaging and non-resonant detection of the NH(4)(NH(3))(n-1) products. Special care has been taken to avoid evaporation of solvent molecules from the excited clusters by controlling the intensity of both the excitation and probing lasers. The high resolution translational energy distributions obtained are analyzed on the base of an impulsive mechanism for the hydrogen transfer, which mimics the direct N-H bond dissociation of the bare pyrrole. In spite of the low dissociation wavelengths attained (~200 nm) no evidence of hydrogen-loss statistical dynamics has been observed. The effects of clustering of pyrrole with ammonia molecules on the possible statistical decomposition channels of the bare pyrrole are discussed.

Slice imaging and wave packet study of the photodissociation of CH3I in the blue edge of the A-band: evidence of reverse 3Q0 ← 1Q1 non-adiabatic dynamics

The photodissociation of CH(3)I in the blue edge (217-230 nm) of the A-band has been studied using a combination of slice imaging and resonance enhanced multiphoton ionization (REMPI) detection of the CH(3) fragment in the vibrational ground state (ν = 0). The profiles of the CH(3) (ν = 0) kinetic energy distributions and the photofragment anisotropies are interpreted in terms of the contribution of the excited surfaces involved in the photodissociation process, as well as the probability of non-adiabatic curve crossing between the (3)Q(0) and (1)Q(1) states. In the studied region, unlike in the central part of the A-band where absorption to the (3)Q(0) state dominates, the I((2)P(J)), with J = 1/2, 3/2, in correlation with CH(3) (ν = 0) kinetic energy distributions show clearly two contributions of different anisotropy, signature of the competing adiabatic and non-adiabatic dynamics, whose ratio strongly depends on the photolysis wavelength. The experimental results are compared with multisurface wave packet calculations carried out using the available ab initio potential energy surfaces, transition moments, and non-adiabatic couplings, employing a reduced dimensionality model. A good qualitative agreement is found between experiment and theory and both show evidence of reverse (3)Q(0)←(1)Q(1) non-adiabatic dynamics at the bluest excitation wavelengths both in the fragment kinetic energy and angular distributions.

Background subtraction in pulsed photoacoustics through neural-network processing

We report on the application of neural-network processing to pulsed photoacoustics for improving the detection limit by subtracting the window-heating-associated background. This technique was applied to the measurement of ethylene traces excited by a TEA (transverse electrical discharge in gas at atmospheric pressure) CO(2) laser. The signal contains a term that shows absorption saturation, characteristic of the absorbing gas, and another, generated by window heating, linearly dependent on laser energy. At low concentrations, normalization to laser energy is not possible owing to the different absorption mechanisms. To overcome this problem we relied on a neural-network filter, trained with experimentally obtained patterns, that subtracts the background and returns the sample concentration. This way, we reduced the detection limit to 20% of the previous limit obtained by reading the main resonance peak amplitude.

Evaluation of the quality of the water in El Hondo natural park located in the east of Spain

The purpose of the present work was to evaluate the quality of the water in El Hondo Park, an important wetland located in the east of Spain (province of Alicante) and included on the Ramsar List. The influence of the input of pollutants was assessed over a 14-month period in order to propose remedial action. Three different sources of waters were studied: irrigation water, brackish water and reservoir water. The irrigation water was found to have a high value of conductivity with high concentrations of Cl-, SO(4)2-, Na+ and K+ due to the influence of the brackish water. The concentration of organic matter given as CODT (total chemical oxygen demand) was found to be in the range of 70-600 mg/L of CODT, which was comparable to low-middle strength wastewater. A high concentration of Chlorophyll (a) was found in samples of reservoir water and the eutrophication of this water was thus observed. A high linear relationship was found among CODT, CODF (filtered COD) and BOD5; among electrical conductivity (E.C.), Cl-, SO4(-2), Na+, K+, Ca2+ and Mg2+ and among pH, CO3H- and CO(3)2- in all the samples evaluated. Taking this fact into consideration, a simplified water quality index (WQI) was calculated. Using this parameter, the quality of the water from different sources and its variation during the period evaluated was determined to be at a maximum during the months of December to February, which coincided with the period of high precipitations and low temperature. The highest values of this parameter were found in the samples corresponding to the reservoir water while the lowest values were found in the samples of the brackish water. By determination of the WQI, the influence of the brackish water on the quality of water for irrigation and reservoir waters was confirmed.

Myeloid mixed chimerism is associated with relapse in bcr-abl positive patients after unmanipulated allogeneic bone marrow transplantation for chronic myelogenous leukemia

BACKGROUND AND OBJECTIVE

Although bcr-abl polymerase chain reaction (PCR) positivity after bone marrow transplantation (BMT) for chronic myelogenous leukemia (CML) is significantly related to relapse, the predictive value of the assay is not very high and therefore most investigators consider that qualitative RT-PCR data alone are too imprecise to enable clinical decisions to be taken in individual cases. To define the clinical outcome of bcr-abl positive patients after unmanipulated BMT better, we sought the origin of hematopoiesis and traced its evolution over time.

DESIGN AND METHODS

Forty-nine patients received allogeneic BMT for CML (39 in chronic phase and 10 in accelerated phase/blast crisis). Median follow-up was 61 months (range 4-92). mRNA and DNA were used to assess bcr-abl and chimerism status respectively. Quantitative VNTR-PCR on total cells and lymphoid or myeloid population allowed us to assign and measure the origin of hematopoiesis.

RESULTS

Both bcr-abl positivity and the presence of mixed chimerism (MC) were significantly associated with relapse (p = 0.0009 and p < 0.0001 respectively). Relapse was observed in one of 39 patients with complete donor chimerism and in 6 of 9 patients with MC. These six cases showed increasing levels of host hemopoiesis and bcr-abl positivity in the CD15-positive population prior to relapse. The other three cases had decreasing or stable low-level MC which was restricted to the T-cells as well as bcr-abl negativity.

INTERPRETATION AND CONCLUSIONS

Whereas the simple detection of bcr-abl fails to identify patients who will relapse with certainty, the assessment of MC by VNTR-PCR does identify patients headed to relapse. Confirmation of myeloid involvement and increasing levels over time further elucidates the clinical outcome of bcr-abl positive patients after BMT.

Increasing mixed haematopoietic chimaerism after BMT with total depletion of CD4+ and partial depletion of CD8+ lymphocytes is associated with a higher incidence of relapse

In this study we analysed the incidence and clinical impact of the persistence of host haemopoiesis (mixed chimaerism, MC) after allogeneic BMT in 35 consecutive patients with haematologic malignancies using a total CD4+ cell-depleted graft with an adjusted dose of CD8+ cells (1x10(8)/kg). Chimaerism was assessed by PCR amplification of VNTRs in 30 evaluable patients: 19 non-CML and 11 CML cases which were also evaluated for the BCR-ABL transcript by RT-PCR. All but one had complete engraftment with a donor profile early post-BMT. At the end of the study period, 12 of 30 patients displayed MC (40%). The overall disease-free survival for MC patients was clearly unfavourable when compared to those who exhibited a donor profile (24.7% vs. 100%, P = 0.005). However, we found that only two of five patients with MC in the non-CML group relapsed, whereas a clear correlation could be made between MC and relapse in CML (seven showed MC, preceding cytogenetic or haematological relapse in six of them, which displayed a prior BCR-ABL mRNA positivity). In addition, a quantitative-PCR approach enabled us to demonstrate that increasing amounts of MC are invariably associated with subsequent relapse, whereas a low stable level of host or complete donor haemopoiesis is consistent with clinical complete remission. Although these results suggest that the clinical impact of MC may depend on the underlying disease, it is compatible with the concept that the graft-versus-leukaemia effect against CML is mainly exerted by donor CD4+ lymphocytes. Elimination of this cellular subset may be responsible for the inability of the graft to prevent a progressive increase in the tumor cell burden.

[Right ventricle with double outlet associated to total anomalous pulmonary venous drainage to innominate vein]

The clinical findings of 2 patients are studied with an association of malformations not previously reported: double outlet right ventricle and total anomalous pulmonary venous connection to the innominate vein. The following features are worth while to be underlined: 1. Both patients showed a discordance between viscero-atrial situs and direction of the apex; 2. In both cases, particularly in case 2, there existed a very unusual spacial relationship between ventricles, the right ventricle being superior with respect to the left ventricular cavity; 3. From the embryological viewpoint, this ventricular arrangement is supposed to be due to an arrest of the development of the heart in the straight tube stage, there being, however, an upwards expansion of the atrioventricular canal and common atrium; 4. An accurate diagnosis of the common or divided nature of the atrioventricular valves has been impossible in these cases; 5. These combination of lesions constitutes a challenge to cardiologists and surgeons as far as the surgical indication is concerned. In that sense, the simple anastomosis of the common pulmonary vein to the left atrium, although is not a radical cure, may be a feasible and beneficial procedure.