Biomedical subjects

M Rodríguez

Publications and source records attributed to M Rodríguez.

At least 199 records · Page 11Linked to original sources

PubMed1998

[Testicular granulocytic sarcoma as a form of relapse in a patient with acute megakaryoblastic leukemia].

Granulocytic sarcoma (GS) is a rare extramedullary tumor composed of myeloblasts and other granulocytic precursors. GS is mostly associated with myeloproliferative disorders, myelodysplastic syndromes and acute myeloid leukaemia. These tumors arise in the absence of leukaemia, at its initial diagnosis or at the time of recurrence. The most common sites of involvement are bone, skin, soft tissue and lymph node. Reports of GS in testis are very rare. We report an unusual case of GS in a patient with megakaryoblastic leukaemia arising in the left testis after four months in complete remission attained with low doses of Ara-C and granulomonocytic stimulating factor.

Aged↗

PubMed1998

Comparison of the effects of ACE inhibition with those of angiotensin II receptor antagonism on systolic and diastolic myocardial stunning in isolated rabbit heart.

The aim was to determine whether enalaprilat (0.08 mg/kg/min) or losartan (0.01 mg/kg/min) administration before ischemia can improve postischemic systolic and diastolic dysfunction ('stunned myocardium') and attenuate the 'hyperfunction' phase at the beginning of reperfusion. An isolated isovolumic rabbit heart preparation was subjected to 15 min of ischemia followed by 30 min of reperfusion without (group 1) or with pretreatment with enalaprilat (group 2) or losartan (group 3). Left ventricular developed pressure and end-diastolic pressure (diastolic stiffness) were measured and the time constant of isovolumic relaxation (T, Tau) and the ratio between +dP/dt and -dP/dt were calculated. In comparison to the stunned group (group 1) both enalaprilat (group 2) and losartan (group 3) exerted a significant protective effect on postischemic recovery of contractile state and diastolic stiffness. Only enalaprilat attenuated the 'hypercontractile' phase. However, both enalaprilat and losartan failed to improve myocardial relaxation. In summary, these data strongly suggest a direct deleterious action of the local renin-angiotensin system on ischemic myocardium and diminution of myocardial stunning with its successful blockade. Although, we can not exclude the possibility that bradykinin has some cardioprotective effect, these data suggest that angiotensin exacerbates myocardial injury.

Angiotensin II↗

PubMed1998

Effects of exercise and EDTA administration on blood ionized calcium and parathyroid hormone in horses.

OBJECTIVE: To determine effects of exercise on blood ionized calcium (Ca2+) and plasma parathyroid hormone (PTH) concentrations in horses and to compare the effects of exercise-induced and EDTA-induced hypocalcemia on PTH secretion. ANIMALS: 17 horses entered in a show jumping competition and 5 horses given EDTA. PROCEDURE: Blood Ca2+ and plasma PTH concentrations were measured before and after exercise in the 17 horses entered in the jumping competition. In the other 5 horses, concentrations were measured during infusion of EDTA IV. RESULTS: Exercise resulted in a significant decrease in blood Ca2+ concentration and a significant increase in plasma PTH concentration, and blood Ca2+ concentration was correlated with plasma PTH concentration. Administration of EDTA resulted in hypocalcemia and an increase in PTH concentration. For the same decrease in Ca2+ concentration, magnitude of the exercise-induced increase in PTH concentration was similar to magnitude of the EDTA-induced increase. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that the increase in plasma PTH concentration in horses after exercise is secondary to hypocalcemia and that the increase in PTH concentration seems to be commensurate with the decrease in Ca2+ concentration.

Animals↗

PubMed1997

A flexible perforated microelectrode array probe for action potential recording in nerve and muscle tissues.

Flexible perforated microelectrode arrays probes for the simultaneous recording of electrophysiological activity between cells have been manufactured using photolithographic thin film techniques. Polyimide was used as the substrate. Gold was used as the active metal with titanium to adhere the gold to the substrate. A coating of silicon nitride improves the electrode isolation. Perforations in the substrate ensure the position of the electrode in tissue and improve the stability of recording during movement. These electrodes were used for extracellular recording in nerve and muscle tissues. The use of a flexible substrate alleviates the mechanical problems associated with local damage caused by rigid substrates during movement.

Action Potentials↗

PubMed1997

A review of carbon disulfide exposure data and the association between carbon disulfide exposure and ischemic heart disease mortality.

Recent regulatory efforts have devoted attention to carbon disulfide (CS2) exposure and its potential effects on the cardiovascular system. To investigate the association between CS2 exposure and ischemic heart disease (IHD) mortality, the analysis presented here had the following objectives: (i) to review historical CS2 exposure data in the viscose rayon industry and identify trends and (ii) to use these historical data to suggest a standard mortality ratio (SMR)-exposure relationship and a threshold level for occupational exposure to CS2, CS2 exposure data were extracted from published studies and used with the SMR versus exposure score relationship developed by Sweetnam et al. (Br. J. Ind. Med. 44, 220-227, 1987) to relate SMRs directly to exposure. Upper and lower bound exposure profiles were derived and used to identify exposure thresholds. For an IHD SMR equal to 100, the upper and lower bound exposures were 60 and 20 ppm, respectively. The analysis indicates that the risk of IHD mortality and its relationship to CS2 exposure is meaningful only for workers exposed to high level for many years. These high levels, which existed many years ago, are no longer found in the workplace. The results of this analysis suggest a safe regulatory exposure level for CS2 between 15 and 20 ppm.

Aged↗

PubMed1997

Comparison of aceclofenac with piroxicam in the treatment of osteoarthritis.

A multicentre, double-blind, randomised, parallel group study was undertaken to investigate the efficacy and safety of aceclofenac (123 patients, 100 mg twice daily) in comparison to piroxicam (117 patients, 20 mg once daily and placebo once daily) in patients with osteoarthritis of the knee. The treatment period of two months was preceded by a washout period of one week duration. On completion of the study, patients in both aceclofenac and piroxicam-treated groups exhibited significant improvement in pain intensity and functional capacity of the affected knee, as represented by the Osteoarthritis Severity Index (OSI) (p < 0.0001 and p < 0.001 respectively). This was further substantiated following the patient's assessment of pain intensity using the Visual Analogue Scale (VAS), in which significant improvements were demonstrated at all time points for each treatment group (p < 0.001). Although both treatment groups showed a significant improvement in all investigator's clinical assessments (functional exploration of the knee, knee flexion and extension (EXT)), there were no significant differences between the groups. There was, however, a more rapid improvement in knee flexion in the aceclofenac group after 15 days of treatment. Both aceclofenac and piroxicam were well tolerated by patients, the most commonly reported adverse events being gastrointestinal, although their incidence was low. Only 24 patients on aceclofenac, as opposed to 33 on piroxicam complained of dyspepsia, epigastralgia and pyrosis. While 7 patients in each group were withdrawn because of adverse events, only one patient with piroxicam was withdrawn because of severe upper gastrointestinal bleeding. Twice as many reports of fecal blood loss were made in the piroxicam group in comparison to the aceclofenac group. In summary, this study confirms the therapeutic efficacy of aceclofenac and suggests that it is a well-tolerated alternative NSAID to piroxicam in the treatment of osteoarthritis.

Adult↗

PubMed1997

Effects of nebulized salbutamol on respiratory mechanics in adult respiratory distress syndrome.

OBJECTIVE: To determine whether nebulized salbutamol improves the respiratory mechanics of patients with adult respiratory distress syndrome (ARDS). We also assessed the mechanisms that contribute to high respiratory system resistances during this disease. PATIENTS AND SETTING: Eleven consecutive patients with ARDS without clinical evidence of chronic obstructive pulmonary disease, admitted to a polivalent intensive care unit, and mechanically ventilated with Siemens Elema Servo C ventilator at constant inspiratory flow. METHOD: Peak airway pressure (Ppeak), airway pressure immediately after end inspiratory occlusion (P1), plateau pressure (P2) and intrinsic positive end-expiratory pressure (PEEPi) were measured at baseline condition and then 5, 15, and 30 min after 1 mg of salbutamol had been administered via a nebulizer through the endotracheal tube. Partial pressure of arterial oxygen (PaO2), heart rate (HR) and mean blood pressure (BP) were monitored and minimal respiratory system resistances (Rrs, m), additional resistances (DRrs) and static compliance (Cst) were computed. RESULTS: Between baseline and post-salbutamol, we observed changes in Ppeak, P1, P2, PEEPi and Rrs, m. As there were no significant differences between values at the different intervals during post administration, the results are described comparing baseline and 15 min post-salbutamol administration values. We found a significant decrease in Ppeak (4.9 +/- 0.8 cmH2O). P1 (3 +/- 0.6 cmH2O). P2 (2.1 +/- 0.6 cmH2O), PEEPi (1.9 +/- 0.5 cmH2O) and Rrs, m (1.9 +/- 0.3 cmH2O/1 s-1); DR, rs decreased in five patients, did not change in four and increased in two. HR, PaO2 and BP did not change. CONCLUSIONS: a) Salbutamol administered through the endotracheal tube by a nebulizer device lessens respiratory system resistances and airway and alveolar pressures, and therefore could decrease the risk of barotrauma and alveolar damage; b) high respiratory system resistances in ARDS have an increased smooth muscle tone component that can be reversible with salbutamol.

Adult↗

PubMed1997

The neuronal system of the saccus vasculosus of trout (Salmo trutta fario and Oncorhynchus mykiss): an immunocytochemical and nerve tracing study.

The neuronal system of the saccus vasculosus of two species of trout was studied with immunocytochemical methods and carboindocyanine-dye (DiI) tract-tracing. The cerebrospinal-fluid-contacting neurons of the saccus were immunoreactive for gamma-aminobutyric acid (GABA), glutamic acid decarboxylase (GAD), and neuropeptide Y (NPY). Immunostaining of alternate sections of the saccus vasculosus of fry with anti-GAD and anti-NPY indicated that these substances were colocalized. The tractus sacci vasculosi and the neuropil of the nucleus sacci vasculosi were also immunoreactive to these substances. The GABA, GAD, and neuropeptide Y immunoreactivity of the saccus vasculosus system appeared early in trout ontogeny. After applying DiI to various levels of the tractus sacci vasculosi of adult trout, we observed massive bilateral saccular projections to the nucleus sacci vasculosi and could follow the course of the sacco-thalamic tract. This tract extended in the subependymal region of the thalamus rostral to the nucleus sacci vasculosi and split into two small tracts that reached the subhabenular-preoptic region. Sacco-thalamic fibers formed extensive periependymal plexuses along their trajectory. Interestingly, no clear evidence of the existence of a saccopetal system was obtained. On the basis of these results, we postulate that the saccus vasculosus system modulates the function of centers of the posterior tubercle and periventricular thalamus.

Aging↗

PubMed1997

The efficacy of laparoscopic surgery in the diagnosis and treatment of peritonitis. Experience with 107 cases in Mexico City.

BACKGROUND: Peritonitis continues to be an important cause of morbidity and mortality and often an etiologic diagnosis is unclear. To evaluate the efficacy and safety of laparoscopy the authors analyzed their 5-year experience with this modality of treatment. METHODS: A review was made of 107 consecutive nonselected laparoscopic procedures performed between October 1990 and November 1995. The diagnosis was established by clinical, laboratory, and imaging findings and confirmed by laparoscopy and/or laparotomy. RESULTS: An etiologic diagnosis was unclear in 35% of the cases and was established in all by laparoscopy; 94 patients (87.9%) were successfully treated by laparoscopy while 13 (12.1%) required conversion. Mortality was 4.6%; 14% had postoperative complications and 7.4% had reoperations. CONCLUSIONS: Laparoscopic surgery is safe and very efficient in the diagnosis and treatment of patients with peritonitis. In most instances a definitive treatment can be carried out without conversion and has the additional and well-known advantages of minimally invasive surgery.

Abdomen, Acute↗

PubMed1997

Evolution of cerebral edema and its relationship with power in the theta band.

In previous papers we have proposed that in patients with space-occupying lesions, delta power was related with the volume of the lesion and theta power with the volume of the edema. In this report we analyze the evolution of 10 patients with space-occupying lesions in whom we measured the volume of the lesion and of the edema before and after treatment that produced changes in these volumes. EEGs were recorded in the leads of the 10-20 system referenced to linked earlobes. Delta and theta powers were calculated for voltage and current source densities (CSD) and compared with age-norms to compute conventional Z-maps. These maps provide probability statements about the deviation of observed values from the norm. Rank correlations between the change in the volume of the lesion before and after treatment and the change in Z-values before and after treatment were significant only in the delta band. However, rank correlations between the change in the volume of the edema and the change in EEG Z-values were only significant in the theta band. These correlations were higher for CSD than for voltage estimates. We also observed that the site of the lesion and of the edema was better represented by CSD maps than by voltage maps. These results are also in agreement with our previous reports, in which we observed more precise localization of brain lesions by CSD than by voltage estimates.

Adult↗

PubMed1997

Effects of estradiol and progesterone on the reproductive tract and on uterine sex steroid receptors in female lambs.

The effects of estradiol-17 beta (E(2)) and progesterone (P) on the reproductive tract and on uterine estrogen receptors and P receptors were studied in 2-mo-old female lambs (n = 11). On Days 0, 1 and 2, E(2) (1 ug/kg, Group E, n = 4), P (0.3 mg/kg, Group P, n = 4) or corn oil (control) vehicle (Group C, n = 3) were administered, and in Day 3 all lambs were slaughtered. Group E (n = 12) had E(2) serum concentrations (mean +/- SEM) of 43.8 +/- 2.2 pmol L , similar to that of the follicular phase; while P concentrations in Group P (n = 12) were similar (2.8 +/- 0.18 nmol L ) to those of the luteal phase of the ewe estrous cycle. The E(2) treatment increased the reproductive tract weight, while P treatment increased only the uterine weight. Both E(2) and P receptors from upper and middle uterine zones (including the myometrium, endometrium and caruncles) were determined by binding assays with tritiated hormones, dextran-charcoal separation and inverse Scatchard analysis. Both the E(2) and P treatments decreased E(2) and P receptor concentrations in upper and middle zones, although the upper zone had higher receptor concentrations than the middle zone (P < 0.01). E(2) receptor concentrations in the upper zone (mean +/- SEM, fmol mg prot) were 1236 +/- 34, 667 +/- 80 and 444 +/- 103 for Groups C, P and E, respectively. The P receptor concentrations were 2434 +/- 135, 1273 +/- 102 and 1536 +/- 213 for the same groups. The high uterine P receptor concentrations allowed P action without prior estrogen priming of female lambs. The present results suggest that E(2) and P might down-regulate their own and each other's receptors during development. The biological responses induced by E(2) and P, as measured by the reproductive tract weight, demonstrated that at an early stage of development uterine receptors are physiologically active.

Journal Article↗

PubMed1997

Behaviour of IgG antibody avidity for the antigen and of IgA antibody in active cytomegalovirus, Epstein-Barr virus, herpes simplex virus and human herpes virus 6 infections. Adaptation of a commercial test.

The clinical value of specific IgA and IgG antibody avidity to herpes simplex virus, cytomegalovirus, Epstein-Barr virus and human herpes virus 6 for the detection of active disease and primary infection, respectively, was evaluated. The IgG avidity test, with a break point of 55%, for the detection of primary infection, and of the IgA test for the detection of disease, were associated with a sensitivity of 97% and 64%, respectively; specificity of 100% and 82%; a positive predictive value of 100% and 76%; and a negative predictive value of 96% and 72%, respectively.

Adult↗

PubMed1997

Income-related inequalities in health: some international comparisons.

This paper presents evidence on income-related inequalities in self-assessed health in nine industrialized countries. Health interview survey data were used to construct concentration curves of self-assessed health, measured as a latent variable. Inequalities in health favoured the higher income groups and were statistically significant in all countries. Inequalities were particularly high in the United States and the United Kingdom. Amongst other European countries, Sweden, Finland and the former East Germany had the lowest inequality. Across countries, a strong association was found between inequalities in health and inequalities in income.

Developed Countries↗

PubMed1997

A follow-up study of EEG coherences in children with different pedagogical evaluations.

A follow-up study on EEG coherence values was carried out with 46 school-age children divided into three pedagogical groups considering their reading and writing abilities (normal subject and children with mild and with serious reading-writing problems). EEGs were recorded at rest, with eyes closed in 15 referential derivations that gave 105 possible coherence values. Coherence was calculated after the elimination of the average reference. Repeated Measure ANOVAs were calculated to evaluate the effects of time, sex, reading-writing problems and their interactions. The second EEG recordings were taken 2-3 years after the first. The results revealed significant increase of coherence values during the time lapse studied, consisting of an increase of frontal coherences in all bands, with the exception of the theta band. The most numerous changes occurred in the alpha band. Very few differences in coherence values were observed between the two EEG recordings by pedagogical groups and by sex suggesting a similar but not igual maturation of coherences of boys and girls and of the three pedagogical groups, in this age range studied. These findings suggests an abnormal coherence development for the reading disabled group, as well as different coherence maturation for boys and girls in this time lapse studied.

Child↗

PubMed1997

Human immunodeficiency virus infection modifies the natural history of chronic parenterally-acquired hepatitis C with an unusually rapid progression to cirrhosis.

BACKGROUND/AIMS: To investigate the possible role of HIV infection in the natural history of chronic parenterally-acquired hepatitis C. METHODS: A multicenter cross-sectional study was performed in 547 patients with chronic parenterally-acquired hepatitis C with or without HIV infection (116 HIV-positive and 431 HIV-negative). Approximate duration of HCV infection was estimated in all patients included, and histologic diagnoses made at different time intervals following HCV infection were analyzed in both groups. Factors related to serum HCV-RNA levels were also investigated. RESULTS: Histologic findings were similar in liver biopsies from both HIV-infected and noninfected patients. However, in the first 10 years, 13 out of 87 (14.9%) HIV-positive subjects developed cirrhosis, in comparison with 7 out of 272 (2.6%) in the HIV-negative group (p < 0.01). Similar results were found in the first 5 and 15 years, respectively, and most of the HIV-negative patients with cirrhosis (42 out of 56) developed cirrhosis in a time interval longer than 15 years. Consequently, mean interval from estimated time of HCV infection to cirrhosis was significantly longer in HIV-negative than HIV-positive patients (23.2 vs. 6.9 years; p < 0.001). Chronic active hepatitis (with and without cirrhosis) and long duration of HCV infection were significantly associated with higher HCV load (p < 0.05). Finally, HIV-positive patients with CD4+ cell counts > 500 cells/ml showed a lower HCV load than those with < 500 cells/ml (p < 0.05). CONCLUSIONS: HIV infection modifies the natural history of chronic parenterally-acquired hepatitis C with an unusually rapid progression to cirrhosis. HIV-related immunodeficiency may be a determinant of higher hepatitis C viremia levels and more severe liver damage.

Adult↗

PubMed1997

Large-scale production in Pichia pastoris of the recombinant vaccine Gavac against cattle tick.

A gene coding for the Bm86 tick protein was recently cloned, expressed in Pichia pastoris and shown to induce an inmunological response in cattle against ticks. Moreover, the Gavac vaccine (Heber Biotec S.A., Havana, Cuba), which contains this recombinant protein, has proved to control the Boophilus microplus populations under field conditions. This paper reviews the development and large-scale production of this vaccine, the efficacy of the resulting product and the strategy followed in designing its production plant. The production plant fulfills biosafety requirements and GMP.

Animals↗

PubMed1997

NOS expression in nigral cells after excitotoxic and non-excitotoxic lesion of the pedunculopontine tegmental nucleus.

The substantia nigra (SN) receives afferents from cholinergic neurons of the pedunculopontine tegmental nucleus (PPTg), a neuronal population that shows high levels of nitric oxide synthase (NOS), the enzyme responsible for the synthesis of nitric oxide. We have investigated the effects of the injection in PPTg of two neurotoxins, kainic acid (an excitotoxic neurotoxin), and ethylcholine mustard azirinium ion (AF64A, a non-excitotoxic neurotoxin), upon the SN cells of the rat, by using choline acetyltransferase (ChAT) immunohistochemistry as a marker of cholinergic neurons, and nicotinamide adenine dinucleotide phosphate diaphorase (NADPHd) histochemistry and NOS immunohistochemistry as markers of nitric oxide-producing neurons. Our results show that in normal rats, the SN contains two populations of NOS-positive neurons: large cholinergic neurons of PPTg that invade the caudal region of the SN, and small elongated neurons lying in the SN pars compacta. After ipsilateral PPTg lesion, another population of nigral cells, constituted by medium sized neurons, became NADPHd/NOS-positive. This was much more evident in AF64A-injected rats, in which many medium sized neurons showed enzymatic activity and normal morphological features, at least during the 90 days after injection. Kainic acid-injected rats, in contrast, showed nigral cell degeneration, an effect not found in AF64A material, and only a few NOS-positive neurons. NADPHd/NOS activity was never present in degenerating neurons. These findings suggest that induction of NOS activity is not involved in nigral cell degeneration, and that nitric oxide could have a protective rather than a neurotoxic role. The possible role of nitric oxide in the pathogenesis of Parkinson's disease is discussed.

Animals↗

PubMed1997

Reliability of four methods for the diagnosis of acute infection by Epstein-Barr virus.

We studied the reliability of new indirect tests in the diagnosis of acute infection by Epstein-Barr virus (EBV). Studied for all samples were method 1, the heterophil antibodies (Abs) (Monolatex, Biokit, Germany); method 2, the IgM Abs to EBV with ELISA tests (antigen pools, Enzygnost, Behring-werke, Germany); method 3, EA (Biotest Diagnostics, Germany); and method 4, the IgG avidity test. The reliability of the four tests for the detection of primary infection by EBV was: sensitivity (method 1: 89.1%; method 2: 100%; method 3: 79.7%; method 4: 99%); specificity (method 1: 98%; method 2: 100%; method 3: 84%; method 4: 100%); positive predictive value (method 1: 97.6%; method 2: 100%; method 3: 73.6%; method 4: 100%), and negative predictive value (method 1: 90.7%; method 2: 100%; method 3: 84%; method 4: 99%). The IgG avidity test (method 4) is simple and automated in the laboratory and is very useful for ascertaining, from a single sample, the time since infection. It is criteria of recent primoinfection higher levels than 55% of IgG with low avidity for the antigen. The investigation of the Abs to antigen pools (method 2) by ELISA of virus had a high reliability, but the investigation of heterophil Abs by latex (method 1) and the Abs IgM to EA (method 2) were lacking in sensibility regarding their use in the diagnosis of the primoinfection.

Acute Disease↗