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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. [ABSTRACT FROM AUTHOR]

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.

Optimal treatment for HIV-related visceral leishmaniasis (VL) has still to be established. A pilot clinical trial was carried out in 57 HIV-VL coinfected patients to compare the efficacy and safety of amphotericin B lipid complex (ABLC) versus meglumine antimoniate. The patients were randomized to receive either ABLC 3 mg/kg/day for 5 days (ABLC-5, 18 patients), ABLC 3 mg/kg/day for 10 days (ABLC-10, 20 patients) or meglumine antimoniate 20 mg Sbv /kg/day for 28 days (19 patients). Treatment was considered successful if parasites were not detected in a bone marrow aspirate after treatment. Parasitological cure was attained in 33% (95% CI: 13%-59%) of the ABLC-5 group, in 42% (95% CI: 16%-62%) of the ABLC-10 group and in 37% (95% CI: 16%-62%) of the meglumine antimoniate group (P = 0.94). Eight out of 19 patients administered antimoniate discontinued treatment prematurely following serious adverse events, compared with one in the ABLC groups (P = 0.0006). The efficacy of ABLC is similar to meglumine antimoniate, but the severity of toxicity in the treatment of HIV-VL is lower with ABLC.

Background: Sevelamer hydrochloride is a recently approved calcium- and aluminium-free phosphate binder. A randomized study comparing sevelamer and calcium acetate was performed to assess the control of hyperphosphatemia in hemodialysis patients., Methods: Administration of phosphate binders was discontinued during a two-week washout period. The patients were then randomized to receive sevelamer or calcium acetate. The laboratory tests were performed monthly for 34 weeks., Results: There was a statistically significant decrease of serum phosphorus in both sevelamer and calcium acetate treatments. In addition, sevelamer improved the lipid profile., Conclusion: This study confirms that sevelamer is effective at lowering serum phosphorus in hemodialysis patients and that it has several striking properties that could be beneficial in atherosclerosis in dialysis patients.

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)

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.

Purpose: The treatment of elderly patients with acute myeloid leukaemia (AML) remains controversial. We present the results of the treatment of a group of patients aged above 70 years with AML diagnosed in our Hospital since 1990., Patients and Methods: We have studied retrospectively the cases of AML in patients older than 70 years diagnosed in our Service since January 1990 to June 1996. Induction treatment was performed, in all cases but one, with two cycles of Ara-C 10 mg/m2/12 h s.c. for 21 days and after haematological recuperation, if complete remission had been achieved, monthly maintenance treatment with Ara-C (25 mg/m2/12 h oral x 5 days), prednisone (40 mg/m2/day x 5 days) y vincristine (1 mg/m2 i.v. x 1 day) was begun., Results: During the period of study 48 patients with AML have been diagnosed in our Service, among them 22 (45.8%) were older than 70 years. One of them could not be considered for the study as not all data from him could be compiled. Among the other 21 patients 5 presented previous haematological processes (4 myelodysplastic syndrome and 1 Waldenström's macroglobulinemia). Initial diagnosis according to FAB classification for AML was as follows: 7 M1, 6 M2, 4 M4, 2 M5 and 2 M6. From these 21 patients 2 received no treatment due to rapid progression and death, among the other 19, one was directly treated with a modification of the maintenance treatment with vincristine and prednisone without response (survival 2 months). The other 18 patients were treated with low-dose Ara-C (described above), among them 3 (16.7%) were not evaluable as they did not finish the first cycle of induction treatment; 8 (44.4%) showed no response; 2 (11.1%) achieved partial remission and 5 (27.8%) complete remission. One patient did not show any response after two cycles of low-dose Ara-C but she obtained complete remission when treated with Ara-C and idaurubicin. Overall mean survival was 5.7 months (median 2; 95% confidence interval 1.6-9.8 months). In the group of patients treated with low-dose Ara-C mean survival was 6.6 months (median 3.5; 95% confidence interval 1.9-11.2 months)., Conclusion: We consider that the treatment with low-dose Ara-C is a valid option in the treatment of elderly patients (aged 70 or above) with AML because 28% complete remissions can be achieved, specially in those ones in which other more aggressive treatments are not possible.

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.

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 bone marrow investigation is a common examination in HIV infected patients for the study of cytopenia, febrile syndromes of unknown origin and extension of neoplastic disorders. A study was made of bone marrow specimens from 35 patients with advanced HIV infection (stage IC or C, CDC, Atlanta) for morphologic and culture investigations (aerobes, anaerobes, fungi, and mycobacteria). In nine patients cytopenia accounted for the investigation of bone marrow specimens (9 aspirates and 3 biopsies); in only two cases did the investigation orientate towards a possible etiology: in the first patient a parvovirus B19 infection and in the second patient a hemophagocytic syndrome. In twenty-five patients the bone marrow specimen was studied because of fever of unknown origin (23 aspirates and 10 biopsies) and only in one case was the identification of Mycobacterium tuberculosis obtained. The other patient was studied for lymphoma staging and aspirate and biopsy examinations were normal. A high percentage of patients had eosinophilia, plasmacytosis, increased iron reserves, fibrosis, and changes consistent with myelodysplasia. In conclusion, in our experience the investigation of bone marrow specimen was of little help to clarify the possible etiology of cytopenia and febrile syndromes of unknown origin in patients with advanced HIV infection.

Purpose: To compare the stability of the effect of two oral anticoagulants, one of them (acenocoumarol) with a short half life and the other one with a long half life (warfarin) in patients in the stable phase of treatment (at least 2 months with treatment before entering the study)., Patients and Methods: During a year period (January-December 1993) a comparative study of two groups of 53 patients each was performed: group 1 patients were treated with warfarin and group 2 with acenocoumarol. Both groups were paired with respect to age, sex, diagnosis for anticoagulant therapy and desired therapeutic range (INR 3-4.5). The mean value of controls per patient, the dosage changes, the evolutive controls and the incidence of haemorrhagic and thromboembolic episodes were studied., Results: The controls performed in group 1 were 728 in total with a mean value of 13.74 per patient and 800 in group 2 with a mean value of 15.09 per patient. A change in the dosage was performed in 214 controls in patients of group 1 and in 269 of group 2. Seventeen patients had 38 haemorrhagic episodes (2 major and 36 minor) in group 1, and 6 of group 2 had 20 episodes (2 major and 18 minor). Significant differences were observed in the mean value of controls (p = 0.04), the evolutive controls (p < 0.001), the global incidence of haemorrhages (p = 0.008) and incidence of minor ones (p = 0.006). No significant differences in dosage were observed. In both groups no thromboembolic episodes during the period of study were reported., Conclusions: Anticoagulant treatment with warfarin is more stable than with acenocoumarol. The total controls and the mean value of controls per patient are decreased. Nevertheless with warfarin we have observed a greater incidence of haemorrhagic episodes.

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.

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.

Purpose: To study the usefulness of different published epidemiological and analytic parameters to decide the treatment with human recombinant erythropoietin (rHuEPO) of anaemic patients with myelodysplastic syndromes (MDS)., Patients and Methods: We have revised 10 published series compiling 115 patients, studying age, sex, initial diagnosis, route of administration and posology, criteria of response, duration of the study, dosis with the response was obtained, response according to initial diagnosis, duration of responses, and effect of the treatment on other hematopoietic series. We have made a comparison between responders and non-responders based on epidemiological and analytical parameters., Results: We have compiled 115 patients with a rate of global response of 23.5%. We have not found significative differences between the route (s.c. or i.v.) or frequency of administration, however the number of responses was higher when rHuEPO was administered three times weekly. A great variability in the criteria of response was observed among the different studies. Most of studies have a duration of three months but we have observed significative differences in the number of responses when the study is longer. We have not found significative differences between responders and non-responders with respect to age, sex, used dosis, transfusional dependency and degree of transfusional dependency, basal serum erythropoietin, time since diagnosis, transfusional period, haemoglobin level among non-transfusion dependent patients and haemoglobin level among transfusion dependent patients. We have found significative differences with respect to initial diagnosis, a higher rate of responses was observed in the refractory anaemia with excess of blasts (RAEB) group. We have not found a higher rate of transformations into acute myeloid leukaemia (AML) among these patients. The effects of the treatment on other haematopoietic series can be considered as anecdotical., Conclusion: The different epidemiological and analytic parameters published up to now are not useful in the decision of including an anaemic patient with MDS in the treatment with rHuEPO. Those patients with RAEB can be benefited with the treatment with rHuEPO. The concomitant use of other cytokines could improve these results.

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.

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.