[Synchronous diagnosis of small-cell lung cancer and Hodgkin lymphoma].
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Antineoplastic Agents↗
Biomedical subjects
G Martínez
Publications and source records attributed to G Martínez.
Third-order aberration theory of Wien filters for monochromators and aberration correctors.
Third-order aberrations at the first and the second focus planes of double focus Wien filters are derived in terms of the following electric and magnetic field components--dipole: E1, B1; quadrupole: E2, B2; hexapole: E3, B3 and octupole: E4, B4. The aberration coefficients are expressed under the second-order geometrical aberration free conditions of E2 = -(m + 2)E1/8R, B2 = -mB1/8R and E3R2/E1 - B3R2/B1 = m/16, where m is an arbitrary value common to all equations. Aberration figures under the conditions of zero x- and y-axes values show very small probe size and similar patterns to those obtained using a previous numerical simulation [G. Martinez & K. Tsuno (2004) Ultramicroscopy, 100, 105-114]. Round beam conditions are obtained when B3 = 5m2B1/144R2 and (E4/E1 - B4/B1)R3 = -29m2/1152. In this special case, aberration figures contain only chromatic and aperture aberrations at the second focus. The chromatic aberrations become zero when m = 2 and aperture aberrations become zero when m = 1.101 and 10.899 at the second focus. Negative chromatic aberrations are obtained when m < 2 and negative aperture aberrations for m < 1.101. The Wien filter functions not only as a monochromator but also as a corrector of both chromatic and aperture aberrations. There are two advantages in using a Wien filter aberration corrector. First, there is the simplicity that derives from it being a single component aberration correction system. Secondly, the aberration in the off-axis region varies very little from the on-axis figures. These characteristics make the corrector very easy to operate.
Journal Article↗
Interferometry of direct photons in central 208Pb + 208Pb collisions at 158A GeV.
Two-particle correlations of direct photons were measured in central 208Pb+208Pb collisions at 158A GeV. The invariant interferometric radii were extracted for 100<K(T)<300 MeV/c and compared to radii extracted from charged pion correlations. The yield of soft direct photons, K(T)<300 MeV/c, was extracted from the correlation strength and compared to theoretical calculations.
Journal Article↗
Design of Wien filters with high resolution.
The design of a compact high-energy resolution device based on a symmetrical double Wien filter is presented. An accurate version of the boundary element method (BEM) is employed to model the shape and behaviour of the filters very precisely. Using a direct ray tracing technique, we investigate the geometrical aberrations in the basic filter, in which dipole and quadrupole electric fields and a dipole magnetic field are present. The additions of a quadrupole magnetic component along with some slight modifications in the geometry produce a drastic reduction in the aberrations.
Artifacts↗
Hyperpigmentation mimicking Laugier syndrome, levodopa therapy and Addison's disease.
The Laugier-Hunziker syndrome is an acquired, idiopathic, benign mucocutaneous hypermelanosis that usually occurs on the lips and oral mucosa, although it may appear at other sites. Nails are frequently involved, mainly forming longitudinal hyperpigmented bands. We report the case of a patient that presented a typical picture of this entity, nearly 1 year after the beginning of treatment with levodopa. Two years after the first lesions occurred, she developed Addison's disease. The patient suffered from a diffuse discrete hyperpigmentation (it was more remarkable on exposed areas) and an intensification of the melanotic macules that were previously noticeable before in oral and genital mucosa, fingers, toes and nails. Hormonal replacement treatment enabled the control of laboratory and general manifestations and to decrease the degree of mucocutaneous hyperpigmentation considerably, despite initial hyperpigmented lesions persisting in described areas.
Addison Disease↗
Suppression of soft nuclear bremsstrahlung in proton-nucleus collisions.
Photon energy spectra up to the kinematic limit have been measured in 190 MeV proton reactions with light and heavy nuclei to investigate the influence of the multiple-scattering process on the photon production. Relative to the predictions of models based on a quasifree production mechanism, a strong suppression of bremsstrahlung is observed in the low-energy region of the photon spectrum. We attribute this effect to the interference of photon amplitudes due to multiple scattering of nucleons in the nuclear medium.
Journal Article↗
[Clinical practice guideline on the management of patients with gastroesophageal reflux disease (GERD)].
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Algorithms↗
BEM simulation of Wien filters.
The boundary element method can provide accurate solutions to the electromagnetic problem in numerical simulations of electron optics devices. In this paper, we describe our approach, which applies a subsectional-bases method to generate a boundary division, representing the shape and behaviour of the Wien filter precisely. We investigate by direct ray tracing the origin of the second-order geometrical aberrations of this filter and propose new designs to reduce them.
Journal Article↗
[Interferon alfa 2b treatment decreases histological activity in children with chronic hepatitis B].
Interferon alfa (IFN-alpha) is the only approved treatment for chronic hepatitis B (HBV) infection. In a non-controlled study 33 pediatric patients infected with HBV and in chronic phase of the disease were included and treated with 3 to 5 x 10(6) IU/m2 body surface of Interferon alpha 2b, 3 times per week, during 4 months. The objective was to evaluate the efficacy of the treatment in terms of the histological, biochemical and viral markers evolution of the patients. The patients were evaluated carrying out determinations of alanine aminotransferase (ALAT), HBsAg and HBeAg before treatment, at the end of the treatment and every 4 months during one year of follow-up. Liver biopsy and Knodell index determination were carried out at the beginning and upon concluding the follow-up. 39.3% of the patients concluded the treatment with normal ALAT values; 7% became HBsAg negative and 14.3% became HBsAg negative. These values ascended after follow-up to 51.5%, 11% and 37.5% respectively. The histological analysis evidenced a decrease of the Knodell index in 69% of the patients, an increase in 14.2%, and 13.8% did not show variation. Correlating the biochemical and histological responses, a favorable outcome was obtained in 36.4% of the patients, evidencing a remarkable reduction of the hepatic cytolysis. The treatment was well tolerated, being the fever the most frequent adverse events. The results confirm that interferon alfa seems to be an effective treatment for children with chronic hepatitis B.
Alanine Transaminase↗
Atmospheric volatile organic compound measurements during the 1996 Paso del Norte Ozone Study.
Ambient air VOC samples were collected at surface air quality monitoring sites, near sources of interest, and aloft on the US (El Paso) and Mexican (Ciudad Juárez) side of the border during a six-week period of the 1996 Paso del Norte Ozone Study. Samples were collected at five sites, three on the US side and two on the Mexican side, during nine intensive operation days when high ozone levels were forecast for the area. Six other sites were sampled to characterize up-wind, down-wind and other emission sources. Samples for determining source profiles were collected for rush hour traffic, propane-powered bus exhaust, automobile paint shop emissions, propane fuels, and industrial manufacturing in Cd. Juárez and a refinery in El Paso. Most samples were collected in electro-polished stainless steel canisters for determination of C2 to C(10+) hydrocarbons by GC-FID. Carbonyl samples were collected on DNPH impregnated cartridges at three surface sites during aircraft flights and analyzed by HPLC. This paper presents the spatial and temporal characteristics of VOC species concentrations and compositions to examine the differences and similarities of the various locations and time periods. Overall surface, total non-methane hydrocarbon values ranged from 0.1 to 3.4 ppmC with the highest concentrations being recorded in the morning and evening at five vehicle-dominated sites, three in Cd. Juárez and two in El Paso. Toluene in El Paso samples and propane, which is used as a cooking and transportation fuel in Cd. Juárez, were the most abundant hydrocarbons. The most abundant carbonyls were acetaldehyde, acetone and formaldehyde.
Air Movements↗
Effect of Mangifera indica L. extract (QF808) on protein and hepatic microsome peroxidation.
The antioxidant activities of QF808, a steam bark extract of Mangifera indica L., were studied on hydroxyl-mediated oxidation of bovine serum albumin (BSA) and in a hepatic microsome system. The extract was effective in reducing the oxidation of BSA, since its half- maximal inhibition concentration (IC(50)) was 0.0049% w/v in the inhibition of carbonyl group formation and lower than 0.0025% w/v in the inhibition of sulfhydryl group loss. QF808 inhibited lipid peroxidation which was initiated enzymatically by reduced nicotinamide adenine dinucleotide phosphate (NADPH), IC(50)= 0.00075% w/v, or non-enzymatically by ascorbic acid, IC(50) = 0.0126% w/v. The extract tested did not inhibit NADPH-dependent cytochrome P-450 reductase activity, since it had no effect on the oxidation rate of NADPH. These results suggest that QF808 has an antioxidant activity, probably due to its ability to scavenge free radicals involved in microsome lipid peroxidation. In addition, QF808 antioxidant profile in vitro is probably similar to its principal polyphenolic component, mangiferin, a glycosylated xanthone.
Animals↗
Ozone treatment reduces markers of oxidative and endothelial damage in an experimental diabetes model in rats.
Ozone has been used as a therapeutical agent and beneficial effects have been observed. However so far only a few biochemical and pharmacodynamic mechanisms have been elucidated. We demonstrate that controlled ozone administration may promote an oxidative preconditioning or adaptation to oxidative stress, preventing the damage induced by reactive oxygen species (ROS). Taking into account that diabetes is a disorder associated with oxidative stress, we postulate that ozone treatment in our experimental conditions might protect antioxidant systems and maintain, at a physiological level, other markers of endothelial cell damage associated with diabetic complications. Five groups of rats were classified as follows: (1) control group treated only with physiological saline solution; (2) positive control group using streptozotocin (STZ) as a diabetes inductor; (3) ozone group, receiving 10 treatments (1.1 mg kg(-1)), one per day after STZ-induced diabetes; (4) oxygen group (26 mg kg(-1)), one per day, as in group 3 but using oxygen only; (5) control ozone group, as group 3, but without STZ. The ozone treatment improved glycemic control and prevented oxidative stress, the increase of aldose reductase, fructolysine content and advanced oxidation protein products. Nitrite and nitrate levels were maintained without changes with regard to non-diabetic control. The results of this study show that repeated administration of ozone in non-toxic doses might play a role in the control of diabetes and its complications.
Animals↗
Time course of oxidative damage in different brain regions following transient cerebral ischemia in gerbils.
The time course of oxidative damage in different brain regions was investigated in the gerbil model of transient cerebral ischemia. Animals were subjected to both common carotid arteries occlusion for 5 min. After the end of ischemia and at different reperfusion times (2, 6, 12, 24, 48, 72, 96 h and 7 days), markers of lipid peroxidation, reduced and oxidized glutathione levels, glutathione peroxidase, glutathione reductase, manganese-dependent superoxide dismutase (MnSOD) and copper/zinc containing SOD (Cu/ZnSOD) activities were measured in hippocampus, cortex and striatum. Oxidative damage in hippocampus was maximal at late stages after ischemia (48-96 h) coincident with a significant impairment in glutathione homeostasis. MnSOD increased in hippocampus at 24, 48 and 72 h after ischemia, coincident with the marked reduction in the activity of glutathione-related enzymes. The late disturbance in oxidant-antioxidant balance corresponds with the time course of delayed neuronal loss in the hippocampal CA1 sector. Cerebral cortex showed early changes in oxidative damage with no significant impairment in antioxidant capacity. Striatal lipid peroxidation significantly increased as early as 2 h after ischemia and persisted until 48 h with respect to the sham-operated group. These results contribute significant information on the timing and factors that influence free radical formation following ischemic brain injury, an essential step in determining effective antioxidant intervention.
Animals↗
Risperidone safety and efficacy in the treatment of bipolar and schizoaffective disorders: results from a 6-month, multicenter, open study.
BACKGROUND: The goal of this study was to assess the efficacy and safety of risperidone in bipolar and schizoaffective disorders. METHOD: 541 patients entered this open, multicenter, 6-month study. Patients were entered provided that they fulfilled DSM-IV criteria for bipolar disorder or schizoaffective disorder, bipolar type, during a manic, hypomanic, mixed, or depressive episode. Risperidone was added to any previous mood-stabilizing medication that the patients were taking. Efficacy was assessed with the Young Mania Rating Scale (YMRS), the Hamilton Rating Scale for Depression (HAM-D), the Positive and Negative Syndrome Scale (PANSS), and the Clinical Global Impressions scale (CGI). Extrapyramidal symptoms (EPS) were assessed using the UKU Side Effect Rating Scale. RESULTS: 430 patients completed the study. Addition of risperidone produced highly significant improvements (p < .0001) on the YMRS and HAM-D at both 6 weeks and 6 months and on the CGI and the scales of the PANSS at both 4 weeks and 6 months. There was a significant reduction in UKU total and subscale scores at 6 months. The mean dose of risperidone was 3.9 mg/day. There was no single case of new-emergent tardive dyskinesia, and there was a very low incidence of exacerbation of mania within the first 6 weeks (2%). Adverse events were few and mostly mild. the most frequent being EPS and weight gain. CONCLUSION: This large study provides additional evidence that risperidone is effective and well tolerated when combined with mood stabilizers in the treatment of bipolar disorder and schizoaffective disorder, bipolar type. Previous concerns about exacerbation of manic symptoms were not confirmed.
Adult↗
Three-pion interferometry results from central Pb+Pb collisions at 158A GeV/c.
Three-particle correlations have been measured for identified pi(-) from central 158A GeV Pb+Pb collisions by the WA98 experiment at CERN. A substantial contribution of the genuine three-body correlation has been found as expected for a mainly chaotic and symmetric source.
Journal Article↗
Prostaglandins and reproduction of the scallop argopecten purpuratus: II. relationship with gamete release.
Levels of prostaglandins E(2) and F(2alpha) were measured in male and female gonadal portions of the functional hermaphroditic scallop Argopecten purpuratus, at the time of spawning. For these measurements, mature scallops were stimulated to initiate their chain of spawning events, and prostaglandins (PGs) were analyzed in samples before stimulation, when animals appeared stimulated to release sperm, during the release of sperm, when animals appeared stimulated to release oocytes, when most of the oocytes had been released, and 24 hr after the end of spawning. The experiment was run twice, once in winter and once in spring. An additional in vitro experiment was carried out to analyze activity of the monoamines dopamine and serotonin on the levels of these prostaglandins. For this, minced tissue of the female portion of the gonad was incubated for different time periods with each of the amines at 10(-5) M. PGs were determined in the tissue samples by radioimmunoanalysis. The results showed that the amounts of the PGs increased significantly in both parts of the gonad during the global process of spawning and decreased when it had been completed. Incubation of minced gonad with the amines affected the time course of PGs variations, i.e., the effect of these compounds depended on the incubation time used. The results support a model for the regulation of spawning which assumes the occurrence of a stimulus which is detected by receptors, processed by nerve cells, and sent to the gonad where intermediation by amines (changing the time course of the process) induces liberation of gametes, in some way modulated by prostaglandins.
Animals↗
[Clinical factors associated with bone mass loss previous cardiac transplantation].
BACKGROUND: A high prevalence of osteoporosis has been described in patients before and after cardiac transplantation. But clinical factors involved in previous bone loss in this condition are not well known. The purpose has been to study bone mineral density (BMD) in patients subject to cardiac transplantation, analyzing clinical and biochemical factors related to bone mass in these patients. PATIENTS AND METHODS: We have studied lumbar and hip BMD in 51 patients candidates to cardiac transplantation, evaluating the functional grade of the cardiopathy, time of evolution of the disease, and antropometric and biochemical markers of bone turnover. BMD was measured using a dual X ray densitometer. RESULTS: A significant decrease in bone mass at lumbar and hip sites was found in patients with regard to normal population. A high prevalence of osteoporosis was found (27.4%). Time of evolution of the disease prior to transplantation was found to be the most important predictive variable in bone loss at trabecular bone (lumbar spine). No modifications were found in blood routine parameters, mineral studies and in serum intact PTH. Resorption bone markers were increased and formation markers were normal, suggesting a elevated turnover osteoporosis. Patients with osteoporosis had less BMI that patients without, indicating a protective effect of body mass. Patients with osteoporosis also had a greater time of evolution of the disease. CONCLUSIONS: There is a decreased bone mass in lumbar spine and hip and a higher prevalence of osteoporosis in patients with cardiac failure before cardiac transplantation. Time of waiting for cardiac transplantation has been an important factor found in the development of metabolic bone disease in these patients.
Adult↗
Effect of diet and temperature upon muscle metabolic capacities and biochemical composition of gonad and muscle in Argopecten purpuratus Lamarck 1819.
Recently spawned Argopecten purpuratus broodstock were conditioned at two temperatures and fed three different diets (microalgae, microalgae mixed with lipids and microalgae mixed with carbohydrates) to examine changes in the biochemical composition of gonad and muscle as well as muscle metabolic capacities. During one experiment, scallops were fed at 3% of their dry mass per day whereas during a second experiment, they were fed at 6% of their dry mass per day. During both experiments, total gonadal levels of lipids and protein increased markedly during conditioning with the two mixed diets at 16 degrees C. These increases were less pronounced at 20 degrees C. Carbohydrate gonadal levels only increased during the second experiment at both temperatures and with the three diets. Of the major biochemical components of the adductor muscle, carbohydrate levels changed most during conditioning. Whereas muscle protein levels increased slightly with gonadal maturation, carbohydrate levels dropped considerably. Despite the marked drop in the levels of glycolytic substrates, only the activities of octopine dehydrogenase in the adductor muscle of the scallops conditioned at 16 degrees C consistently decreased. Muscle levels of glycogen phosphorylase were higher in mature than in recently spawned (control) scallops, suggesting a role in the transfer of glucose equivalents from the adductor muscle to other tissues.
Journal Article↗