Isothermal volume contours generated in a freezing gel by embedded cryo-needles with applications to cryo-surgery.

Three-dimensional numerical simulations of multi-cryo-needle surgery were performed with cryo-needle temperature variations taken from matched experimental data. The transient temperatures and frozen volumes generated by simultaneously operating up to three 1.47 mm OD cryo-needles embedded in a phase-changing gel simulating the properties of biological tissues, were studied. In all cases studied, the volumes enclosed by the "lethal", -40 degrees C isotherm, achieved most of their final size in the first few minutes of operation, thus obviating the need for long application times. After 30 min of application of the one-, two- or three-cryo-needles, the ablation ratio attained 3%, 3-6% and 3-8%, respectively, depending on cryo-needle placement configurations. Synergistic effects of using multi-cryo-needles were reflected in the increased expansion of both the radial and axial locations of the isothermal contours. Within each number of cryo-needles used, however, the differences in these locations were rather small, and, as a general rule, tended to somewhat decrease with increasing the placement "density" of the cryo-needles. For each two- and three-cryo-needle application, there is a certain combination of placement configuration and application time that would produce the largest, temperature-specific, volume. As a general guideline, multiple cryo-needles should not be placed too close to each other in order to enhance their synergistic effect. Results of this study should be useful in the design of cryo-needle placement and operation protocols and in understanding the limitations of the freezing-ablation process.

Fisura anal cronica: esfinterotomía interna lateral ambulatoria con anestesia local / Chronic anal fissure ambulatory laterla internal sphincteritimy under local anesthesia

Se analizan los resultados obtenidos en 87 pacientes operados de una fisura anal crónica por medio de una esfinterotomía submucosa interna lateral de acuerdo a los principios técnicos difundidos por Notaras.Se destaca el valor y la buena tolerancia por parte de los pacientes de la anestesia local,lo que permitió una cirugía ambulatoria y disminución de los costos operativos.Asimismo,queremos hacer notar que es un método eficaz, de técnica rápida y sencilla,con escasísimas complicaciones y que permitió la curación del 82,8 por ciento de los pacientes tratados quienes retornaron a sus tareas habituales en 24 horas

Eighty-one percent event-free survival in advanced Burkitt's lymphoma/leukemia: no differences in outcome between pediatric and adult patients treated with the same intensive pediatric protocol.

BACKGROUND: Advanced Burkitt's lymphoma (BL) has an extremely poor prognosis in adults. With a previous protocol including CNS prophylaxis, 40% of our adult patients achieved CR and only 13% became long survivors. In 1988, following this poor experience, we adopted a very intensive pediatric-derived protocol. PATIENTS AND METHODS: Twenty-one consecutive patients, 8 adults (median age 35, stage III: 1; IV: 7; leukemias: 6) and 13 children (median age 10, state III: 8; IV: 5; leukemias: 4) were treated with the same protocol (POG 8617), based on alternate two-phase cycles with sequential high-dose CTX, VCR, ADM + CNS chemoprophylaxis (phase A) and HD MTX + HiDAC (phase B). Adults received 6 cycles, children 8; i.t. prophylaxis in phase B was omitted in adults. RESULTS: Twenty of 21 (95%) patients achieved CR (adults 100%, children 92%). Two patients died early; 2 relapsed at 4 and 9 months. With a median follow-up of 28 months (4-96), 17 patients (81%) are event free (adults 75%, children 85%). Severe infections affected 62% of adults and 15% of children. CONCLUSIONS: (1) The prognosis of adult advanced BL definitely improved with this intensive protocol. (2) There were no differences in outcome between adults and children. (3) Outcome of lymphoma and leukemia was similar. (4) Severe infections occurred frequently in adults. This intensive pediatric protocol requires a careful supportive therapy.

Fisura anal cronica: esfinterotomía interna lateral ambulatoria con anestesia local / Chronic anal fissure ambulatory laterla internal sphincteritimy under local anesthesia

Se analizan los resultados obtenidos en 87 pacientes operados de una fisura anal crónica por medio de una esfinterotomía submucosa interna lateral de acuerdo a los principios técnicos difundidos por Notaras.Se destaca el valor y la buena tolerancia por parte de los pacientes de la anestesia local,lo que permitió una cirugía ambulatoria y disminución de los costos operativos.Asimismo,queremos hacer notar que es un método eficaz, de técnica rápida y sencilla,con escasísimas complicaciones y que permitió la curación del 82,8 por ciento de los pacientes tratados quienes retornaron a sus tareas habituales en 24 horas

Haematological profile in cancer patients: analysis of circadian pattern.

This study was intended to evaluate whether unusual circadian patterns in blood cells exist in cancer patients. Ten patients (five men and five women) suffering from advanced malignancy were compared with a control group of apparently healthy volunteers, of comparable age and sex. After synchronization of daily activities, meals and rest of the two groups, blood samples were taken four times (at 8.00 a.m., 12.00 a.m., 4.00 p.m. and 8.00 p.m.) in a single day. The total red and white cell counts, haemoglobin, platelet count, and neutrophil, lymphocyte, eosinophil, monocyte and basophil differential white cell counts were analysed by both conventional (Student's t-test; multifactorial analysis of variance) and inferential statistics (single and mean cosinor). The average values for platelets (P = 0.04), white blood cells (P = 0.004) and lymphocytes (P << 0.001) showed significant changes with time, independently of disease state. Cosinor analysis indicated a circadian rhythmicity for haemoglobin (P = 0.02), eosinophils (P = 0.014), and lymphocytes (P = 0.001) in healthy subjects, and for eosinophils only (P = 0.024) in cancer patients.

[Infected pancreatic necrosis. Reexaminations planned with locoregional anesthesia]. / Necrosis pancreática infectada. Reexploraciones programadas con anestesia locoregional.

Eleven patients with infected pancreatic necrosis are presented. They were treated with necrosectomy and lavage with programmed reexploration and peridural anesthesia. Nine of these patients, had biliary stone disease as associated pathology and two were chronic alcoholics. We used the contrast computerized tomography and CT-guided percutaneous aspiration to obtain fluid for Gram stains and culture, as a diagnostic method. The patients were reoperated 3 to 5 times each 48-72 hs., with a mortality of 18.2%.

T-cell phenotypic profiles in the cerebrospinal fluid and peripheral blood of multiple sclerosis patients.

Thirty-nine patients with clinically definite multiple sclerosis (MS) entered the study. Of 28 subjects with a relapsing-remitting course, 19 were classified in acute relapse, 9 in remission; 11 patients had a progressive course without remissions. Furthermore, 6 subjects with inflammatory neurological disease (IND), and 10 with non-inflammatory and non-neoplastic neurological disease (NIND) were investigated. We simultaneously studied cerebrospinal fluid (CSF) and peripheral blood (PB) T-, B- and NK-cell subsets, as defined by following monoclonal antibodies: anti-CD3, -CD4, -CD8, -CD19, -CD16, -HLA-DR and -IL-2-R. We found a significant increase of CD4+ T-cells compared with controls in CSF, with respect to PB, of MS patients, particularly in acute relapse. An increase of HLA-DR+ cell percentages in the CSF than in the PB in all MS groups, especially in attacks of MS but also in remission, was also observed, with a positive correlation between CD4+ T-cell and DR+ cell percentages both in the CSF as well as in the PB of relapsing MS patients. These findings, together with the increase of IL-2-R+ cells in the PB, particularly in relapsing MS, give further support for the presence of a systemic T-cell activation in MS.

Effect of 17 beta-estradiol on calcium response to phytohaemagglutinin in human lymphocytes.

Pre-treatment of human lymphocytes with 17 beta-estradiol diminishes the increase in concentration of cytosolic free calcium after stimulation with phytohaemagglutinin. The effect is dependent on 17 beta-estradiol concentration and on the preincubation time. The effect is not due to an interaction between 17 beta-estradiol and phytohaemagglutinin, but appears to be a consequence of the binding of the hormone to the cell surface. The effect is specific for 17 beta-estradiol, since the alpha isomer and other steroid hormones (progesterone, testosterone, diethylstilbestrol and 5 alpha-androstan) have no effect. Since the effect of the 17 beta-estradiol can be suppressed by treatment of lymphocytes with ouabain, it appears that the effect of estradiol on the rise of cytosolic calcium induced by phytohaemagglutinin is mediated by the (Na, K)-ATPase.

Myelin basic protein inhibits the calcium response to phytohaemagglutinin in human lymphocytes.

Myelin Basic Protein, one of the major membrane protein component of the central nervous system, was used to probe the molecular mechanism of cellular activation by phytohaemagglutinin. Pre-treatment of human lymphocytes with myelin basic protein results in a lower rising of cytosolic concentration of free calcium after stimulation with phytohaemagglutinin. This effect is dependent on myelin basic protein concentration and on the preincubation time of the protein with the cells. It is not due to a interaction between myelin basic protein and phytohaemagglutinin, but appears to be a consequence of the binding of the protein to the cell surface. The reduction of the rise of cytosolic calcium induced by phytohaemagglutinin is specific for the myelin basic protein because other proteins like albumin and protamine have no effect.

Effect of 17 beta-estradiol on partition behavior of human erythrocytes in dextran-poly(ethylene glycol) aqueous phases.

Preincubation with 1 nM 17 beta-estradiol changes the partition behaviour of human erythrocytes in dextran-poly(ethylene glycol) aqueous phases. Erythrocyte partition decreases reaching a minimum after 5 min of incubation, then slowly increases returning to starting values after 30 min. The effect is specifically induced by the isomer of estradiol, whereas the alpha isomer and other steroid hormones (progesterone, testosterone and 5 alpha-dihydrotestosterone) are uneffective. The effect of the hormone can be suppressed by treatment of erythrocytes with either N-ethyl maleimide, sodium vanadate, or ouabain, or carrying out incubations in potassium-free buffer. These data suggest that the effect of estradiol on phase partition of erythrocytes is mediated by the (Na,K)-ATPase.

Myelin basic protein inhibits formyl-peptide induced chemotaxis in human neutrophils.

Myelin basic protein, one of the major membrane protein component of the central nervous system, was used to probe the molecular mechanism of cellular activation. Pre-treatment of human neutrophils with myelin basic protein selectively inhibits the formyl-peptide-induced chemotaxis, without affecting chemotaxis evoked by casein and activated serum. Furthermore, both the degranulation and superoxide anion production stimulated by the chemotactic peptide are not modified by the prior treatment of the neutrophils with myelin basic protein.

An experimental study of pressure losses in pulsatile flows through rigid and pulsating stenosis.

The time-dependent pressure curves of a pulsatile flow across rigid and pulsating stenoses were investigated experimentally in a laboratory simulator of the outflow tract of the heart right ventricle. The experiments were performed within the range of physiological conditions of frequency and flow rate. The experimental setup consisted of a closed flow system which was operated by a pulsatile pump, and a test chamber which enabled checking different modes of stenosis. Rigid constrictions were simulated by means of axisymmetric blunt-ended annular plugs with moderate-to-severe area reductions. The pulsating stenosis consisted of a short starling resistor device operated by a pulsating external pressure which was synchronized by the pulsatile flow. It was found that the shape of the time-dependent pressure curve upstream of the stenosis was different in the case of rigid stenosis than in the pulsating one. Potential clinical applications of the work may relate to diagnosis of the type of stenosis in the congenital heart disease known as Tetralogy of Fallot.