High-voltage pulse generator for time-of-flight mass spectrometry in electrospray thrusters.

Electrospray thrusters exhibit diverse operational modes based on the nature of ejected particles. Time-of-flight mass spectrometry is frequently employed to analyze the composition of the plume. This study introduces a novel converter-based bipolar high-voltage pulse generator aimed at producing synchronized bipolar high-voltage pulses with controllable voltage levels and frequencies, specifically tailored for the study of electrospray thrusters. The proposed topology generates bipolar high-voltage rails from a low-voltage power source through the forward-flyback with Cockcroft-Walton voltage multiplier topology. Subsequently, fast high-voltage MOSFETs are employed to generate high-voltage pulses. This paper outlines the operational principles and design methodologies of the pulse generator. Experimental verification corroborates its operational principles and functionalities, revealing that the pulse rise and fall times consistently remain below 30 ns, while the voltage can be tuned within the range of 300-1000 V. An electrospray thruster was employed to conduct a thorough and practical validation of the high-voltage pulse generator. This included generating time-of-flight curves and mass spectra of the plume, resulting in precise differentiation of all particles present.

[Terminal illness, death... in the words of professionals. A qualitative study based on in-depth interviews with health professionals]. / Enfermedad terminal, Muerte... en palabras de los profesionales (I). Un estudio cualitativo de entrevistas en profundidad a profesionales de la salud.

The authors of this study are interested in listening to the experiences professional doctors and nurses who work face to face with patients in terminal phase of their illnesses have. For this reason, the authors carried out a series of in-depth interviews with these professionals in order to know the real difficulties and obstacles which these professionals experience in real cases, as well as the procedure methods followed with these patients. The authors publish the results obtained in eight of these interviews, four with doctors and four with nurses; given the length of these interviews, the authors have decided to publish them in two consecutive articles which form one complete study This study is qualitative and the analysis of data obtained has been structured around the proposed research questions, keeping the diversity and variability how to deal with patients, plus the experiences shown by those interviewed, by citing their words textually.

Allogeneic bone marrow transplantation vs chemotherapy for the treatment of childhood acute lymphoblastic leukaemia in second complete remission (revisited 10 years on).

In 1989 we carried out a trial comparing allogeneic BMT to chemotherapy (CT) in 76 children with relapsed acute lymphoblastic leukaemia (ALL). Ten years on we have clinically revised outcome to firmly establish the role of each treatment, to analyse the importance of length of first remission and to provide long-term actuarial results for disease-free survival (DFS) and relapse rate in each group. For 21 patients within the transplantation group, probability of DFS and relapse are 42.8 +/- 10.8% and 40.2 +/- 11.7% (s.e.), respectively. In the chemotherapy group, probability of DFS is 10.0 +/- 4.74% (P = 0.001) and probability of relapse 87.5 +/- 5.2% (P = 0.0004). These results strongly reflect those at initial analysis, confirming a key role of BMT in the management of ALL in second remission. Moreover, on univariate analysis only two factors influenced DFS: treatment group and length of first complete remission (less or more than 30 months from first CR). Thus, it seems clear that the best therapeutic option in early relapse is BMT, whereas DFS in late relapse is at the limit of significance (P = 0.07), with a higher relapse rate in the CT group. Although encouraging results using intensified rotational combination chemotherapy have been published, prospective randomised studies are needed to assess with certainty the best therapeutic option in these patients.

[Lymphoma of the ocular adnexa]. / Linfomas de los anexos oculares.

Ocular adnexa are rarely involved in lymphomas. Four cases are reported of lymphoma involving the ocular adnexa. In two cases a previous systemic involvement existed or simultaneous to the ocular involvement; another patient had systemically a different histological pattern to that observed in the ocular region, and the fourth patient only had ocular region, and the fourth patient only had ocular symptoms; we therefore recorded two cases of primary ocular lymphoma. The lymphoma was located at the orbit in two cases and at the conjunctiva in the other two cases; the condition was bilateral in three cases. The most common symptom was exophtalmus; other major symptoms were diplopia and disturbances in ocular motility. The histological examination revealed three low grade lymphomas and one case of intermediate grade. Management of patients included radiotherapy and different chemotherapeutic regimens with a good response in all cases. A higher ocular relapse rate was observed in those patients with systemic involvement; in one primary case the condition resolved spontaneously. A review of the literature on clinical, diagnostic and therapeutic issues is made.

Waldenström's macroglobulinemia complicated with acute myeloid leukemia. Report of a case and review of the literature.

The evolution of Waldenström's macroglobulinemia (WM) into chronic or acute myeloid leukemia (AML) is a rare event. Most of these cases have occurred after treatment with alkylating agents. We herein report a case of WM terminating in an acute myelomonocytic leukemia after treatment with prednimustine and chlorambucil and present a review of the literature.

rHuEpo for the treatment of anemia in myelofibrosis with myeloid metaplasia. Experience in 6 patients and meta-analytical approach.

BACKGROUND AND OBJECTIVE: Experience with recombinant human erythropoietin (rHuEPO) in the treatment of the anemia secondary to myelofibrosis with myeloid metaplasia (MMM) is slight up to now. We present our results of the treatment of 6 patients and a review of the literature in search of possible parameters predicting response to this treatment. DESIGN AND METHODS: From January 1994 to June 1996 all transfusion-dependent patients with MMM diagnosed in our hospital were included in this study. We established a minimum period of 4 weeks of treatment and a maximum of 12 if no response was observed. Initial dosages used were 100 U/kg s.c. 3 times weekly, increasing by 50 U/kg every 4 weeks where no response was observed. Response was defined as a reduction > or = 30% of the previous transfusional needs. The review of the literature was made using a MEDLINE search (January 1990-December 1996) on the keywords erythropoietin, myelofibrosis, and agnogenic myeloid metaplasia. A statistical study was made in search of possible parameters to predict response. The parameters studied include age, sex, hemoglobin, serum erythropoietin (sEPO) levels, transfusional dependency, transfusional requirements per month prior to treatment, maximum dosages used and dosage at which response was obtained. RESULTS: Only 2 of our 6 patients responded, both at a dosage of 600 U/kg/week (200 U/kg 3 times weekly s.c.). In addition to our 6 patients we have found only 28 other patients in the literature. For statistical calculation 2 of our patients were not considered as they did not complete the period of study. The overall rate of response was 17/32 (53.1%). In the univariate analysis comparing responders and non-responders we found a tendency to significance with respect to sex (p = 0.07), sEPO (p = 0.07) and transfusional needs in units of packed red blood cells per month (PRBC/m) (p = 0.13). In this way patients with low sEPO, females and those with low transfusional needs (< 3 PRBC/m) respond better. This better response in females could be explained by the fact that their disease situation was more stable (with both lower sEPO levels and transfusional dependency). The best cut-off point in the sEPO to predict response was 123 mU/mL. No important side-effects have been observed except three cases of aggravation of splenomegaly. In two cases this condition improved when the rHuEPO was discontinued. The association of rHuEPO with hydroxyurea or interferon does not seem to affect the response. INTERPRETATION AND CONCLUSIONS: Though the number of patients is low, our data suggest that some MMM patients, in particular females and individuals with low sEPO levels and with low transfusional needs, might benefit from rHuEPO in terms of elevation of hemoglobin levels. Unfortunately, transfusion dependent-patients, i.e. those in whom a beneficial effect of rHuEPO would be most welcome, are unlikely to respond, and more generally, treatment is not cost effective in medically responsive patients.

[Information and worry among patients with non-oncohematological pathologies upon arrival at the hematology clinic]. / Información y preocupación de los pacientes con patología no oncohematológica al llegar a la consulta de hematología.

PURPOSE: Patients are frequently referred to the haematologist to be studied due to the presence of processes that are not properly haematological. We have studied the group of outpatients with non-oncohaematological pathologies referred to our external haematology clinic to evaluate their knowledge about the reason for consultation, the existence or not of worry upation and its degree at the arrival. PATIENTS AND METHODS: We have made a prospective study including all patients with non-oncohaematological processes (n = 204) who were referred for the first time to our external consultation between April and October 1997. We evaluated in each patient, using an inquest, the following data: age, sex, origin (hospital consultations or urban or rural health centres), reason for consultation, knowledge of the reason for consultation (yes/partially/no), existence or not of worry (yes/no) and when present, its degree (low, moderate, high). The inquiry was made to the parents in those patients aged under 12 years. We have analyzed all adults, each group of adult patients (rural, urban, hospital) separately and compared one group to each other, all pediatric patients and we have compared as well the overall results obtained with adult patients with those from the parents of pediatric patients. RESULTS: 1) Adult patients (n = 169; 78 referred from hospital, 59 from urban and 32 from rural health centres): with respect to the knowledge of the reason for consultation 49.7% of them knew it perfectly, 20.1% partially, and 30.2% did not know about it. 48.5% of patients arrived worried to the clinic, 16.6% of them with a high degree, 17.8% moderate and 14.2% low. 2) Adults referred from primary health care (urban versus rural health centres): We have found neither significant differences in the knowledge of the reason for consultation, worry or its degree with respect to age, sex or origin (urban or rural), nor in the worry or its degree with respect to the patient knowledge of the reason for consultation. 3) Adults referred from other hospital units: The mean age of patients who knew the reason for consultation was significatively lower than that observed in the group who did not (respectively 43.3 and 57 years) (p = 0.003). These differences did not exist with respect to sex. Differences in the existence or not of worry with respect to sex were almost significant, women arrive more worried than men (57.1% and 31.8% respectively, p = 0.07). No significant differences were found in the existence or not of worry and its degree with respect to age or knowledge of the reason for consultation. 4) Comparison between both groups of adults patients (hospital consultation and health centres): No significant differences in the knowledge of the reason for consultation, existence or not of worry and its degree have been found with respect to the other parameters studied. 5) Paediatric patients (n = 35; 8 referred from hospital, 14 from urban and 13 rural health centres): With respect to the knowledge of the reason for consultation 62.9% of them knew it perfectly, 17.1% partially and 20% did not know about it. 80% of patients' parents arrived worried at consultation, 45.7% with a high degree, 20% moderate and 14.3% low. 6) Comparison between paediatrics and adult patients: we have only found significative differences in the existence or not of worry (80% and 48.5% respectively, p = 0.001) and its degree (65.7% of parents with moderate or high worry and 34.4% of adults, p = 0.0004). Parents of paediatric patients arrive at our consultation more worried and with a higher worry degree than the other adults. CONCLUSION: We consider that patients referred to our external consultation of haematology for the first time arrive with a poor knowledge of their reason for consultation. This observation does not seem to have any relation with age, sex or origin (hospital consultations, urban or rural health centres). (ABSTRACT TRUNCATED)

[Chronic neutrophilic leukemia associated with myeloma. Simultaneous presentation]. / Leucemia neutrofílica crónica asociada a mieloma. Presentación simultánea.

A case of chronic neutrophilic leukaemia associated with multiple myeloma is reported. The patient had a 6 months history of bruising and weight loss, and showed mature neutrophilic leukocytosis, hepatosplenomegaly, high neutrophil alkaline phosphatase score, hyperuricaemia, neutrophils with pseudotoxic granulation and scarce Döhle bodies; moreover, a monoclonal IgG lambda was detected amounting 57.3 g/L. The bone marrow was grossly hypercellular with marked myeloid hyperplasia and aggregates of immature plasma cells. After treatment during 1 year with melphalan and prednisone she is well, although persisting with neutrophilic leukocytosis, slight splenomegaly, and the monoclonal IgG decreased to 25.8 g/L.

[Primary testicular lymphoma. Report of two cases]. / Linfoma testicular primario. Presentación de dos casos.

Primary testicular lymphoma (PTL) is the most frequently diagnosed testicular tumor in men over 60 years, in spite of this circumstance it is a rare process. Two cases of PTL are reported, the first one in a child and the second in an adult. Both cases were intermediate grade lymphoma and had low stage (IEA), presenting initially as an enlargement of the testicle as the only symptom, the second case presented involvement by contiguity of the abdominal muscles. Immunohistological markers showed T nature in the first case, and B in the second. The treatment applied in both cases was orchiectomy and systemic chemotherapy using COP-BLAM/IMVP-16, in the child prophylaxis of the central nervous system using methotrexate was made. Response to treatment was good, the first patient achieved complete remission and his survival at present is 24 months, the second patient died 5 month after diagnosis due to stroke without having completed chemotherapy but with an important reduction of the tumoral mass. A review of the literature on clinical, diagnostic and therapeutic issues is made.

[Hodgkin's disease and HIV: relations between CD4/CD8 rate, histology and stage]. / Enfermedad de Hodgkin y VIH. Relación entre el cociente CD4/CD8, histología y estadio.

Hodgkin's disease (HD) is not currently accepted as an AIDS diagnostic criterion by the Centers for Disease Control (Atlanta), although there are reports on a higher incidence of the disease in HIV infected patients, with the special feature of a marked clinical and histological aggressiveness. A review of the literature was made and a total of 54 cases of HD compiled of patients with HIV infection. The relationships between the absolute counts of CD4 and the CD4/CD8 ratio with histopathology and with the stage at diagnosis was investigated. No significant differences were found between the absolute counts of CD4 and CD4/CD8 ratio with the clinical stage of disease, histopathologic subgroup or presence of B symptoms in HD. Nevertheless, lower CD4 counts were observed in more advanced clinical stages and in patients with B symptoms; the highest CD4/CD8 ratios were observed in patients with more advanced disease. It is hypothesized that immunological disturbances caused by HIV would lead to more aggressive histological lesions and more advanced stages of HD in HIV-positive patients. Thus, the inclusion of HD as a diagnostic criterion of AIDS would be warranted.

[T-cell-rich B-cell lymphoma. Presentation of 3 cases]. / Linfoma B rico en células T. Presentación de tres casos.

T-cell-rich B-cell lymphoma (TBL) is a rare entity not included in the classical classifications of non-Hodgkin's lymphomas (NHL), presenting usually at diagnosis in advanced stages and with extranodal involvement. Its differential diagnosis, based on immunophenotyping technics, include other entities with different treatment and prognosis, mainly lymphocytic-predominance Hodgkin disease and peripheral T-cell lymphoma; this differential diagnosis has importance in patient's survival. We present 3 patients, two males (one of them with HIV infection) and one female, aged 38, 60 and 64 respectively, diagnosed as having TBL. The two former patients presented advanced stages at diagnosis. None of them was initially diagnosed as having TBL, the diagnosis were immunoblastic NHL in the first patient, peripheral T-cell lymphoma in the second and mixed cellularity Hodgkin's disease in the third one. The first patient was not treated due to rapid worsening and early death of septic shock; the other two cases were treated with COP-BLAM/IMVP-16 protocol achieving partial and complete remission respectively after 6 cycles of treatment. Comments about clinical, pathological and differential diagnostic aspects are made.

[Kikuchi-Fujimoto disease associated with acute infection by herpesvirus 6]. / Enfermedad de Kikuchi-Fujimoto asociada a infección aguda por virus herpes 6.

The histiocytic necrotizing lymphadenitis or Kikuchi-Fujimoto disease is a very rare entity in Spain. We present a 34-year-old arabic male admitted to hospital because one-month story of asthenia, anorexia, weight loss, fever and lymphadenopathies in all palpable sites. Analytic studies were all within normal limits except LDH levels and globular sedimentation rate, both raised. After cervical lymph node biopsy performance high grade Non-Hodgkin lymphoma was initially diagnosed. During admission he complained from pain in both shoulders and an erythematous desquamative eruption in trunk appeared. Some days later, a second lymph node biopsy was performed and Kikuchi-Fujimoto disease was diagnosed. Serologic tests for human herpes virus 6 were positive demonstrating active associated infection. He begun treatment with indomethicin, fever and general symptoms disappeared one week later discontinuing treatment. Two months after discharge, all lymphadenopathies had disappeared. A review on epidemiological, clinical, pathological and differential diagnosis issues is made.

A necrotic soft-tissue lesion due to Corynebacterium urealyticum in a neutropenic child.

Corynebacterium urealyticum has been associated mainly with infections of the urinary tract. Other infections due to this organism are highly unusual. We report what we believe is the first case of necrotic infection of soft tissue due to C. urealyticum in a neutropenic child who was previously treated with chemotherapy. The infection was cured when the patient was treated with vancomycin and surgical debridement. The increase in the number of neutrophils may also have contributed to the patient's recovery.

Prospective evaluation and follow-up of European patients with visceral leishmaniasis and HIV-1 coinfection in the era of highly active antiretroviral therapy.

A prospective descriptive study was designed to determine the impact of highly active antiretroviral therapy (HAART) in the evolution of visceral leishmaniasis (VL) in HIV-1 infected patients. Thirty-two patients were treated with meglumine antimoniate or amphotericin B in lipid formulations. Patients who had undergone previous HAART at study entry (n=17) continued with therapy while receiving treatment for VL. Patients who had never undergone HAART started it after VL treatment finished (n=15). Ten patients were lost to follow-up. All of the remaining patients (n=20) continued to receive HAART and were followed for an average of 441 days. Relapses were observed in 5 of 20 patients. These results indicate that HAART neither prevents the incidence of VL relapse nor modifies the clinical picture described in the pre-HAART era.

[Hemorrhagic complications in patients treated with oral anticoagulants]. / Complicaciones hemorrágicas en pacientes en tratamiento anticoagulante oral.

PURPOSE: We have studied the haemorrhagic episodes occurred in patients treated with oral anticoagulants, with special reference to their type, frequency and severity and analyzing the risk factors that could influence in their production. PATIENTS AND METHODS: We carried out a retrospective study in 435 patients of the haemorrhagic episodes occurred since January 1989 to December 1991, determining in each one the prothrombin time expressed as INR, the time from the beginning of treatment, the patient's age and the known or underlying pathologies that could predispose to haemorrhage; depending on their severity these episodes were classified as moderate and major. RESULTS: We observed 50 haemorrhagic episodes in 50 patients (11.5%) which represents 7 x 100 patient/years, 30 (6.8% of the total patients or 4.2 x 100 patient-years) were moderate and 20 (4.5% of the total patients or 2.8 x 100 patient/years) were major. The mean age in patients with haemorrhage was 50.5 years. The incidence of hemorrhages in the first month of treatment was 60.8 x 100 patient/years; 9.4 x 100 patient/years in the period from the first month to the first year of treatment; and 3.6 x 100 patient/years in the period from the first year of treatment. The most frequent type of haemorrhage among the moderate ones was haematuria (46%) and among major ones digestive haemorrhages (26%). Depending on the coagulation level, 37 patients (66%) were within therapeutical range. Depending on patients' sex, the incidence was 23 (46%) males and 27 (54%) females. We observed at risk predisposing factors hypertension (18%), stroke (12%), hepatic disease (8%) and myocardial infarction (8%). CONCLUSION: We have found no relationship between haemorrhagic episodes and patients' age or sex. The risk of haemorrhage is higher at the beginning of the treatment and increases with the level of anticoagulation, which makes the beginning of treatment with lower doses more desirable, increasing them progressively until the desired level is achieved. Previous hypertension, stroke, hepatic disease and myocardial infarction are factors predisposing to haemorrhage.

[Treatment with oral anticoagulants (acenocoumarol): influence of the initial doses in the incidence of hemorrhagic and thromboembolic episodes]. / Tratamiento con anticoagulantes orales (acenocumarol): influencia de la dosis inicial en la incidencia de episodios hemorrágicos y tromboembólicos.

PURPOSE: To compare two initial doses of oral anticoagulant (acenocoumarin) studying the haemorrhagic and thromboembolic episodes occurred during the first month of treatment, the mean time and necessary controls until achievement of the desired level of anticoagulation. PATIENTS AND METHODS: From january 1992 to december 1993; a comparative study of two groups of patients was performed: group 1, compiling 129 patients chosen at random and retrospectively, who begun oral anticoagulant treatment with 4 daily mg of acenocoumarin; and group 2, compiling 129 patients chosen prospectively, who begun with 2 mg daily. In both groups the mean time and the number of controls performed until achieving the desired level of anticoagulation were analyzed, as well as the haemorrhagic episodes occurred during the first month of treatment, their severity (classified into major and minor ones), the level of anticoagulation when they occurred and their possible causes. In the same way the thromboembolic processes occurred during that period in both groups were studied. RESULTS: The mean time necessary to achieve the desired level of anticoagulation was 3.8 days in group 1 and 6.3 in group 2; the mean number of controls performed in group 1 was 1.2 and in group 2 it was 1.8. We have observed 19 haemorrhagic episodes, 15 in group 1 (4 minor and 11 major); and 4 in group 2 (2 minor and 2 major). We have found significant differences with respect to the mean time (p < 0.01), number of controls (p < 0.01) and incidence of hemorrhages (p = 0.017) between groups 1 and 2. One thromboembolic episode was registered in each group: in group 1 a deep venous thrombosis and in group 2 a stroke. CONCLUSION: The initial daily doses of acenocoumarin of 2 mg is as effective as the 4 mg one in the prevention of thromboembolic episodes, with a significant reduction in the number of haemorrhages observed during the first month of treatment. However this produces a prolongation in the necessary mean time and more number of controls performed until the achievement of the desired level of anticoagulation.