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Biomedical subjects

M Alonso

Publications and source records attributed to M Alonso.

At least 19 recordsLinked to original sources
PubMed1995

Vectors for the genetic manipulation of African swine fever virus.

Plasmid vectors designed to facilitate the genetic manipulation of African swine fever virus (ASFV) are described. Our results demonstrate that the beta-glucuronidase enzyme (GUS) can be used to follow gene expression in ASFV-infected cells. Infectious plaques formed by ASFV expressing GUS are visually detectable, thus providing a simple and highly sensitive method for the selection of ASFV recombinants. These and previous results have allowed us to construct two chimeric gene cassettes that constitute the basic tools for the generation of vectors to carry out the deletion of multiple target sequences from the ASFV genome. These cassettes, formed by: (a) a virus promoter; (b) the coding sequence of a reporter gene, either Lac Z or gusA; and (c) a strong signal for the 3' end formation of ASFV mRNAs, can be easily isolated by endonuclease restriction from their corresponding plasmid vectors. A general insertion/coexpression plasmid vector, pEPV2, has also been constructed. pEPV2 facilitates the insertion of foreign genes, together with the Lac Z reporter, into the thymidine kinase locus of ASFV. The functionality of pEPV2 has been tested by generating a recombinant ASFV expressing the luciferase gene. The vectors presented in this report constitute the first reported set of tools for the genetic manipulation of ASFV.

African Swine Fever Virus↗
PubMed1995

Male gonadal function after chemotherapy in survivors of childhood malignancy.

Investigations of adult patients have shown that chemotherapy causes gonadal damage, but much less information is available about the impact of chemotherapy on gonadal function in children with malignant disease. At one time, being prepubertal during therapy was thought to confer some protection against chemotherapy induced gonadal damage. However, recent studies have indicated otherwise. We designed this study to assess gonadal function in 15 postpubertal males who had received polychemotherapy for a malignant disease during childhood and we compared them with 13 control adults males. The mean age of the patients at the time of the study was 18.2 +/- 3.6 years (range 13.8-29.0), and when given chemotherapy treatment was 10.2 +/- 3.0 years (range 6-16). At that time 12 were prepubertal and at the time of the study all were Tanner V. The mean interval from the completion of treatment until the study was 6.42 years (range 2.0-16.5). All patients had received polychemotherapy. We evaluated testicular size, sperm counts, LH and FSH after GnRH test, and testosterone levels. Puberty had progressed normally in all patients. We found no significant differences in testosterone and basal LH levels between patients and controls. However, we detected an appreciable difference in peak LH levels (P < 0.05) and in basal and peak FSH levels (P < 0.001). Seven patients had exaggerated LH response to GnRH, indicating dysfunction of the Leydig cells. The results of semen analyses were: 8 patients had azoospermia, 3 oligospermia, and 1 patient had a normal semen analysis. All patients with semen abnormalities presented a basal and peak FSH higher than the mean +2 SD of the control group. In summary, we found no evidence of gonadal protection in prepubertal patients. We found a high incidence of germinal cell damage, whereas Leydig cell abnormalities were found less often. An endocrine study of patients that have received chemotherapy is warranted.

Adolescent↗
PubMed1995

Comparison of Z and multivariate statistical brain electromagnetic maps for the localization of brain lesions.

Conventional Z maps provide probability statements about the deviation of observed values from the norm. Galán et al. (1994) introduced Simultaneous Significance Probability Scales to detect abnormalities over the whole map, making use of the information provided by the topographic structure of dependencies. They also described multivariate brain electromagnetic (MBE) maps for compact presentation of complex spatio-temporal information. In this paper, using the distance-based localization receiver operating characteristic curves (DL-ROC curves), we compare the localization provided by computed tomography with that provided by Z and MBE maps in 61 patients with brain lesions. Maps were calculated for absolute power and relative power in delta, theta, alpha and beta bands for voltage and current source densities (CSD). In each patient, all maps were compared and the map with the highest value of the area of the DL-ROC curve was considered to be the "best map." Z maps of CSD were the "best maps" in 24 patients. In the voltage montage, we observed that multivariate maps add some information not contained in the Z maps. However, for CSD, Z maps were more accurate than multivariate maps. A very consistent finding was the observation that lesions were better detected by maps analyzing the delta band, while edema was better represented by maps in the theta range.

Brain Damage, Chronic↗
PubMed1995

Transcranial magnetic stimulation in multiple system and late onset cerebellar atrophies.

Central motor conduction time (CMCT) after transcranial magnetic stimulation (TMS) of the cortex, electromyography and nerve conduction velocity were performed in 24 patients with multiple system (MSA) and late onset cerebellar atrophy (LOCA) (often olivopontocerebellar atrophy--OPCA -). CMCT was abnormal in 7 patients with OPCA and one with LOCA. CMCT abnormalities (43% of cases) and increased threshold (68%) were more often found within OPCA group than in another multisystem atrophy and LOCA. Reduction in amplitude of the response after TMS was significantly correlated with cerebral hemispheres's atrophy. Increased threshold was correlated with upper vermal hemisphere atrophy and enlargement of the fourth ventricle. Electrophysiologic signs of mixed peripheral neuropathy were found in 8 patients. TMS abnormalities were not related to peripheral nerve involvement. Marked variation in CMCT suggests heterogeneity in these diseases. However, the percentage of CMCT abnormalities in OPCA group suggests that TMS seems to play a role in the neurophysiological diagnosis of these heterogeneous disorders.

Adult↗
PubMed1995

Microsurgical penis replantation after self-mutilation.

The microsurgical reattachment of a penis following self-amputation by a psychiatric patient is discussed. This is the 15th case reported in the literature. We have reviewed the previous reports and outline the management of penis amputation. The importance of using microsurgical techniques in order to achieve better functional and cosmetic results is discussed.

Adult↗
PubMed1995

[Aortic intramural hematoma. An atypical pattern equivalent to aortic dissection].

A case is presented of a hypertensive woman who had suffered a stabbing back pain for some three hours, with mild irradiation to precordium and accompanied by vegetative signs. A sinusal rhythm and negative T waves of little depth were seen on the ECG. A transthoracic bidimensional echocardiogram (TTE) showed a normal left ventricle with a somewhat dilated aortic root and the existence of a double echo running parallel to the anterior wall of the aorta but non-ondulating and without a visible intimal flap. Because of suspected aortic dissection an urgent contrasted CAT and a transesophageal echocardiogram were performed. These were informed as an aneurysm of the aortic root with mural thrombus from the ascending to descending aorta, but with no existing intimal flap suggesting dissection. A cardiac catheterization showed a mildly some dilated aortic root without dissection signs and normal left ventricle and coronary arteries. The patient was presented for surgical evaluation but, since no dissection was present, was not considered urgent surgery; she was admitted to the coronary unit and died 48 hours later in a situation of acute pericardial tamponade, documented by TTE, surely due to rupture of the aortic root to pericardial sack. This way of presenting threatened aorta rupture that has been only recently recognized is discussed, as well as some misconceptions which must be avoided.

Aged↗
PubMed1994

Prepyloric antrectomy, truncal vagotomy, and front pylorotomy for the treatment of duodenal ulcer.

We have performed a suprapyloric antrectomy with anterior pylorotomy and truncal vagotomy in 106 patients with chronic duodenal ulcer between 1975 and 1990. Follow-up was carried out in 94 patients, during a mean time of 6 years. We have had no postoperative mortality and no long-term recurrence. The percentage of Visick I patients is similar to that after truncal vagotomy and antrectomy. We, therefore, believe that this procedure is safe and can be performed when an antrectomy is mandatory to avoid the operative morbidity and mortality of classic antrectomy.

Adult↗
PubMed1994

[Clinical and investigative approaches in mitochondrial diseases. A review of 15 cases].

The results of laboratory investigations in concerning 15 patients suspected of mitochondrial disease (MD) are presented. Our purpose is to provide an outline of the investigative modalities that support the clinical suspicion and have been found to be useful in the diagnosis. Five clinical groups were studied including 5 exercise intolerances (2 with inflammatory myopathy), 3 with myopathies (1 with dilated cardiomyopathy), 2 with progressive external oftalmoplegia (1 associated with cerebellar ataxia+epilepsy+hypertrophic cardiomyopathy+pes cavus), 4 with encephalopathies (3 with myoclonic encephalopathies with ataxia and dementia and 1 with epilepsy and tremor), and 1 with metabolic acidosis and cardiomyopathy. We used the following categories of investigative procedures: clinical phenotype analysis including pedigree study, neurophysiological tests, bicycle ergometric evaluation, neuroimaging, microscopic study of skeletal muscle biopsy, post-mortem examination, biochemical assays and molecular genetic studies. EMG showed myopathic changes in 5 cases, features of neuropathy in 2, mixed myopathic and neuropathic pattern in 1 and nonspecific changes in 3. EMG was normal in 3 patients. The most common skeletal muscle abnormalities were variation in fiber size (60%), lipid inclusions (33.3%), oxidative subsarcolemmal aggregates (26.7%) and ragged-red fibers (26.7%). Electron microscopy revealed mitochondrial abnormalities in 8 out of 14 patients' muscle biopsies, and in myocardiac and hepatic tissues of another. Site of biochemical defect was located in 12 patients. Complex I defect in 6, complexes I+IV deficiencies in 3, complex II defect in 1, complex IV deficiency in 1, complexes II+IV deficiencies in 1, and complex III defect in 1. In 2 patients the biochemical defect was not located. Mitochondrial DNA alterations were not found in 7 investigated patients. The clinical spectrum of MD has become increasingly wider. After the clinica suspicion, the diagnosis depends up on the appropriate use of skeletal muscle biopsy, biochemical investigations and molecular genetic techniques. Conventional EMG and automatic measurement of the electromyogram are particularly helpful in confirming the clinical suspicion in patients with predominantly central nervous system disease or in cases in which clinical signs are few.

Adolescent↗
PubMed1994

Detection of antibodies to Babesia bovis using an ELISA test.

An enzyme-linked immunoassay (ELISA) is described for the detection of antibodies to Babesia bovis using a partially purified antigen. The optimum conditions required to perform the test were determined and 210 serum samples were comparatively tested using ELISA and indirect immunofluorescence (IFA) tests, finding a diagnostic coincidence of 96.1%, a relative sensitivity of 96%, and a relative specificity of 96.4%.

Animals↗
PubMed1994

Development of a Babesia bovis live attenuated vaccine.

Babesia bovis is the blood parasite causing the highest morbidity and mortality of cattle in Cuba. Thus a control program based on immunization with a vaccine using an attenuated strain of the parasite was developed. For this purpose, a virulent B. bovis strain was isolated and then attenuated by the traditional method in which biological characteristics, proteolytic activity and vector transmissibility were studied. The protection conferred by the vaccine was measured by vaccinating cattle which then was challenged with a heterologous strain. In order to assess postvaccination accident risks, 2603 cattle were vaccinated and those showing clinical signs of babesiosis were treated. A study of cost-benefit was performed in a herd where frequent outbreaks of babesiosis occurred; prevalence and clinical case incidence in vaccinated and nonvaccinated animals were determined. Vaccinated animals survived to challenge whereas two control animals died. In 2% of the vaccinated animals less than 6 months of age, postvaccination accidents occurred, whereas in older animals this index was higher (p < 0.001). The cost-benefit study showed a rate of approximately $10 pesos (national currency) for each peso invested due to the high mortality caused by the parasite. Until an effective, killed vaccine is available, vaccination with live vaccines is advantageous to prevent bovine babesiosis.

Animals↗
PubMed1994

[Lymphocele as a complication of renal transplantation].

Lymphoceles are a complication of renal transplantation surgery. The source of this lymphatic collections is the lymph draining through the lymphatic vessels located in the transplanted kidney sinus and surrounding the iliac vessels of the receptor. The main etiological factor is the surgical technique used when dissecting these structures for graft placement. Several factors have been suggested as favouring their occurrence, acute rejection being highlighted as one. This paper reviews a series of 517 renal transplantations performed in our service, with a lymphocele incidence of 5.2% (28). Using a log regression model, the influence of age, sex, time in dialysis, presence of tubular acute necrosis in the graft following placement, acute rejection and immunological regime, for the appearance of lymphocele were analyzed. Age and lack of acute tubular necrosis were the only two factors selected by the model. Also, clinical signs and symptoms as well as therapy instituted were analyzed, emphasizing that puncture-drainage and instillation of iodine povidone was 100% effective.

Adolescent↗
PubMed1993

Stimulation of IL-2-activated natural killer cells through the Kp43 surface antigen up-regulates TNF-alpha production involving the LFA-1 integrin.

We have previously described that a mAb directed against a surface dimer (Kp43) expressed by NK cells was able to regulate cell proliferation, enhance the cytotoxicity of IL-2-activated NK cells, and activate phospholipase D. In this work we have analyzed the ability of the anti-Kp43 mAb to regulate the production of TNF-alpha. Our results show that the stimulation of IL-2-activated NK cells with soluble anti-Kp43 mAb or its F(ab')2 activated the secretion of the cytokine, inasmuch as this effect is associated with the induction of cellular aggregation. The intensity of the Kp43-mediated stimulation varied among different IL-2-activated NK cell samples. Even in those instances where the anti-Kp43 mAb alone could not detectably enhance TNF-alpha production, it displayed a synergistic effect combined to a soluble anti-CD16 mAb, which on its own did not efficiently activate cytokine production. The anti-Kp43 mAb also cooperated with a phorbol ester, although it did not modify the TNF-alpha production triggered by a Ca2+ ionophore. The anti-Kp43-mediated effect, which required the preactivation of cells with IL-2, was inhibited by cycloheximide and actinomycin D and was associated with an increase in the levels of TNF-alpha-specific mRNA. It is noteworthy that the Kp43-mediated production of TNF-alpha was partially inhibited by anti-CD18, anti-CD11a and anti-ICAM-1 mAb that blocked LFA-1-dependent cellular interactions, which impaired NK cell aggregation and, moreover, was dependent on the presence of extracellular Mg2+, thus suggesting that the leukocyte integrin is involved in the activation process triggered through Kp43.

Antibodies, Monoclonal↗
PubMed1993

Splenectomy in human immunodeficiency virus-related thrombocytopenia.

To evaluate the efficacy and safety of splenectomy in patients with human immunodeficiency virus (HIV)-related thrombocytopenia, 30 HIV-infected patients with thrombocytopenia (platelet count < 50 x 10(9)/l) who underwent splenectomy were followed prospectively for a mean period of 42 months. There were no perioperative deaths and morbidity was minimal. Twenty-one patients had a persistent complete response, six had a partial response and were asymptomatic after splenectomy, and only three showed no response. Three patients developed acquired immune deficiency syndrome during follow-up, an incidence that was no different from that expected. Splenectomy is a safe and effective treatment in HIV-infected patients with severe symptomatic thrombocytopenic purpura resistant to medical therapy.

Adolescent↗
PubMed1993

Correlation between computed tomography and voltage and current source density spectral EEG parameters in patients with brain lesions.

In a group of patients with space-occupying brain lesions, CT measurements were correlated with absolute power (AP) and relative power (RP) of the delta, theta, alpha and beta EEG bands, calculated from the raw EEG potentials (EEGp) and from the Laplacian estimates also called "current source densities" (CSD). Rank correlations were calculated between the number of abnormal values in each band and the following CT measures: volume of the lesion and of the edema, density of the edema, percentage of ventricular collapse and midline shift. Abnormal spectral values are those which are significantly higher than the norm for the same age, in the delta and theta bands, and significantly lower in the alpha and beta bands. Spectral parameters obtained from the CSD showed higher correlations with CT measures than those calculated from the EEGp. In the Laplacian, all CT measures had a significant correlation with delta AP. Theta AP was significantly correlated with the volume and density of the edema, as well as with midline shift. Significant correlations were also observed with delta and alpha RP. However, changes in RP were considered to be a consequence of the increase in delta AP. Canonical correlation analyses between AP and RP calculated from EEGp or CSD and the first 3 CT measures showed that the volume of the lesion was only correlated with delta AP and RP. The volume and density of the edema showed a significant correlation with delta, theta and alpha AP calculated from EEGp and only with theta and alpha AP in the Laplacian. Since the EEGp tends to produce a more extensive and diffuse picture of abnormality, whereas the Laplacian acts as a spatial filter emphasizing local sources over distant sources, we concluded that edema is related not to delta activity, but to the theta and alpha power.

Adolescent↗
PubMed1993

Cross-sectional study of percentual changes in total plasmatic fatty acids during pregnancy.

Total plasma fatty acids were analysed in 75 first trimester pregnant women, 32 second trimester pregnant women, 27 women at delivery and 38 non-pregnant women. Eleven fatty acids were studied by capillar gas chromatography SP-column. Compared with non-pregnant women, in the first trimester there was a significant percentual increase in palmitic, palmitoleic, stearic and docosahexaenoic acids, whereas linoleic and eicosapentaenoic percentually decreased. Between the first and second trimester a significant increase in the proportion of palmitic acid and a significant percentual decrease in arachidonic acid was detected. Between the second trimester and delivery the aforementioned changes were more marked. Between the second trimester and delivery there was also a significant percentual increase in oleic and linolenic acids, whereas the proportions of stearic, linoleic, dihomogammalinolenic and docosahexaenoic acids significantly decreased. It is suggested that the intake in polyunsaturated fatty acids should be increased during pregnancy, specially in the third trimester.

Adult↗