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L García

Publications and source records attributed to L García.

At least 55 records · Page 3Linked to original sources
PubMed2000

Construction and characterization of a nonproliferative El Tor cholera vaccine candidate derived from strain 638.

In recent clinical assays, our cholera vaccine candidate strain, Vibrio cholerae 638 El Tor Ogawa, was well tolerated and immunogenic in Cuban volunteers. In this work we describe the construction of 638T, a thymidine auxotrophic version of improved environmental biosafety. In so doing, the thyA gene from V. cholerae was cloned, sequenced, mutated in vitro, and used to replace the wild-type allele. Except for its dependence on thymidine for growth in minimal medium, 638T is essentially indistinguishable from 638 in the rate of growth and morphology in complete medium. The two strains showed equivalent phenotypes with regard to motility, expression of the celA marker, colonization capacity in the infant mouse cholera model, and immunogenicity in the adult rabbit cholera model. However, the ability of this new strain to survive environmental starvation was limited with respect to that of 638. Taken together, these results suggest that this live, attenuated, but nonproliferative strain is a new, promising cholera vaccine candidate.

Amino Acid Sequence↗
PubMed2000

Effects of infantile thymectomy on ovarian functions and gonadotrophin-induced ovulation in prepubertal mice: role of thymulin.

The effects of thymectomy performed on 10-day-old (Tx-10) mice on spontaneous puberty and the ovulatory response induced by gonadotrophin treatment were analysed, together with the effects of thymulin replacement from 10 days of age. Infantile thymectomy induced a delay of puberty, a decrease in serum 17beta-oestradiol concentration and a reduced total number of follicles. Injection of thymulin (12 ng/g body weight) to Tx-10 mice resulted in an earlier onset of puberty, a decrease in the weights of ovaries and uterus, and an increase in serum 17beta-oestradiol concentrations. In control and Tx-10 mice, treatment with pregnant mare serum gonadotrophin (PMSG) (5 IU) at 25 days of age resulted in ovulation and the numbers of ova shed by ovulating animals were similar. When the animals were injected with 1 IU PMSG ovulation did not occur. In Tx-10 mice, both 1 and 5 IU PMSG increased the number of follicles to values similar to those observed in the controls. In Tx-10 mice the sequential injection of PMSG (1 IU) and human chorionic gonadotrophin (hCG) (3 IU) resulted in ovulation, but the number of ova shed was lower than in controls. When these animals were injected daily with thymulin, an increase in the number of ova shed and serum 17beta-oestradiol concentrations was observed. The uterine weight of Tx-10 mice was always significantly reduced in response to gonadotrophin treatment. Thymulin injection in PMSG-hCG-treated Tx-10 mice provoked a significant increase in uterine weight. The results suggest that the presence of the thymus after the neonatal period is necessary to normal ovarian development and function. The increase in gonadotrophin-induced ovarian response produced by thymulin replacement indicates that this peptide has a role in this process as one of the connecting signals between thymus and ovaries.

Animals↗
PubMed2000

Systemic lupus erythematosus: mortality and survival in Argentina. A multicenter study.

OBJECTIVE: To analyze the factors associated with mortality, survival and causes of death in patients with systemic lupus erythematosus (SLE) in Argentina. PATIENTS AND METHOD: A series of 366 patients with SLE (45 men and 321 women), mean age 29 y (range 11-70 y) and mean disease duration 6 y, was evaluated from 1990 to 1998. A total of 57 clinical, serological and therapeutic variables were studied. RESULTS: Five- and 10-year survival was 91% and 85% respectively. Forty four patients died (12%): 54% due to sepsis and 32% due to active SLE. Mortality risk factors included heart involvement CRR 3.82), hyperlipidemia (RR 2.72), renal damage (RR 2. 62), infections (RR 2.44), lung disease (RR 2.20) and myositis (RR 2. 07). High-dose prednisone (RR 3.4) or cyclophosphamide (RR 9.19) treatments increased the risk of sepsis (P=0.003) as a cause of death. However, corticosteroids, antimalarial agents and accumulated cyclophosphamide doses proved to be protective factors in overall mortality figures (RR <1). CONCLUSIONS: The main risk factors of death in SLE were heart involvement, hyperlipidemia and renal damage. Treatment with steroids, antimalarial agents and cyclophosphamide improved survival. High-dose corticosteroids and cyclophosphamide were associated with sepsis as a cause of death.

Adolescent↗
PubMed2000

[Technology for the whole utilization of brewer's yeast in food industry].

A flexible scheme for the fractionation of brewer's yeast was developed. The procedure allows the production of different products such as: dry yeast flakes, dry yeast pills, yeast-extract based table sauce, yeast protein concentrates and soy-like sauce. The investment required for the processing of one ton per day is below 2 million dollars with an overall profitability higher than 53%. Investment is recovered in 0.75 years. The production of food ingredients from yeast upgrades its biomass about 25 fold. Present procedure is compared with other biomass fractionation processes taking into account the utilization of all technological streams where the process becomes environmentally friendly since effluent production significantly lower than similar technologies.

Analysis of Variance↗
PubMed1999

Activation of a Ca2+-permeable cation channel by two different inducers of apoptosis in a human prostatic cancer cell line.

1. We have combined patch clamp recording with simultaneous [Ca2+]i measurements in single LNCaP cells (a human prostate cancer cell line), to study the activation of Ca2+-permeable channels by two different inducers of apoptosis, ionomycin and serum deprivation. 2. In perforated patch recording, LNCaP cells had a membrane potential of -40 mV and a resting [Ca2+]i of 90 nM. Application of ionomycin at levels that induced apoptosis in these cells (10 microM) produced a biphasic increase in [Ca2+]i. The first rise in [Ca2+]i was due to release of Ca2+ from internal stores and it was associated with a membrane hyperpolarization to -77 mV. The latter was probably due to the activation of high conductance, Ca2+- and voltage-dependent K+ channels (maxi-K). Conversely, the second rise in [Ca2+]i was always preceded by and strictly associated with membrane depolarization and required external Ca2+. Serum deprivation, another inducer of apoptosis, unmasked a voltage-independent Ca2+ permeability as well. 3. A lower concentration of ionomycin (1 microM) did not induce apoptosis, and neither depolarized LNCaP cells nor produced the biphasic increase in [Ca2+]i. However, the first increment in [Ca2+]i due to release from internal Ca2+ stores was evident at this concentration of ionomycin. 4. Simultaneous recordings of [Ca2+]i and ion channel activity in the cell attached configuration of patch clamp revealed a Ca2+-permeable, Ca2+-independent, non-selective cation channel of 23 pS conductance. This channel was activated only during the second increment in [Ca2+]i induced by ionomycin. The absence of serum activated the 23 pS channel as well, albeit at a lower frequency than with ionomycin. 5. Thus, the 23 pS channel can be activated by two unrelated inducers of apoptosis and it could be another Ca2+ influx mechanism in programmed cell death of LNCaP cells.

Apoptosis↗
PubMed1999

Differential clinical features of early-onset panic disorder.

BACKGROUND: Although panic disorder (PD) begins typically in adulthood, an earlier onset is not uncommon. Recent studies on early-onset PD indicate that this subgroup of patients may display distinct clinical characteristics. OBJECTIVE: To compare a subgroup of early-onset PD patients with the rest of the sample. METHOD: A consecutive series of 442 patients with PD were included. Family histories were investigated, and clinical assessment employed the following instruments: Hamilton's scales, Global Functioning Scale, Marks-Mathews' Fears and Phobia Scale, and Panic-Associated Symptom Scale. The age threshold for 'early-onset' was considered at 18 years. RESULTS: A total of 45 patients (10.2%) exhibited early-onset PD, with a mean age at onset of 14.6. They were younger and had a longer duration of illness than later-onset patients. No differences were found in severity of panic symptoms, anxiety or depressive symptoms, and social functioning. They had more comorbidity with simple phobia, social phobia, and substance dependence. Rates of PD among first-degree relatives were higher in the early-onset group. CONCLUSION: Early-onset PD patients displayed a greater familial loading, but clinical severity of their panic-agoraphobia symptoms was not higher. Comorbidity was greater with phobic and substance-related disorders.

Adult↗
PubMed1999

Circadian variation of plasma cortisol in prepubertal children with normal stature, short stature and growth hormone deficiency.

OBJECTIVES: When studying the relationship between spontaneous secretion of growth hormone (GH) and cortisol in children, most studies show no correlation in mean levels of these two hormones, while others found positive or even strongly negative correlations. These contradictory results could be partly due to the inability to properly compare hormones that are characterized by circadian and ultradian variations in their secretory profiles. We aim here to study possible differences in rhythm characteristics of plasma cortisol with stature and to compare the circadian secretory patients of cortisol and GH. PATIENTS: We analysed data from 135 prepubertal children: (1) 14 GH-deficient children; (2) 36 children with short stature (2-3 SD below their peer group mean); (3) 57 children with very short stature (3-4 SD below their peer group mean); and (4) a reference group of 28 children with normal stature (+/- 2 SD). Subjects were living in a hospital setting on a diurnal waking (07.30-22.30 h), nocturnal resting routine during sampling, consuming the usual hospital diet at fixed times. MEASUREMENTS: Cortisol and GH concentrations were determined by radioimmunoassay in plasma obtained at about 2-3 h intervals during most of the day and at half-hour intervals between 22.00 and 02.00 h. Circadian rhythm characteristics obtained by least-squares estimation were compared between groups divided according to gender and stature with a parameter test. RESULTS: Show a statistically significant circadian rhythm in cortisol secretion for all groups studied (P < 0.001 in all cases). A comparison of circadian parameters indicated similar characteristics between subjects of short, very short and normal stature. Despite a borderline statistically significant difference in rhythm-adjusted mean and amplitude of GH between nondeficient and GH-deficient children, there was no difference in the circadian pattern of cortisol secretion between these two groups. No correlation was found in circadian mean, amplitude, average, standard deviation, standard error, minimum or maximum between GH and cortisol for any of the groups of children. CONCLUSIONS: Any possible relation between GH and cortisol remains unclear. Moreover, GH-deficient children are not necessarily characterized by either hyper- or hypocortisolaemia.

Child↗
PubMed1999

Preliminary assessment of the safety and immunogenicity of a new CTXPhi-negative, hemagglutinin/protease-defective El Tor strain as a cholera vaccine candidate.

Vibrio cholerae 638 (El Tor, Ogawa), a new CTXPhi-negative hemagglutinin/protease-defective strain that is a cholera vaccine candidate, was examined for safety and immunogenicity in healthy adult volunteers. In a double-blind placebo-controlled study, no significant adverse reactions were observed in volunteers ingesting strain 638. Four volunteers of 42 who ingested strain 638 and 1 of 14 who received placebo experienced loose stools. The strain strongly colonized the human small bowel, as evidenced by its isolation from the stools of 37 of 42 volunteers. V. cholerae 638, at doses ranging from 4 x 10(7) to 2 x 10(9) vibrios, elicited significant serum vibriocidal antibody and anti-Ogawa immunoglobulin A antibody secreting cell responses.

Adult↗
PubMed1999

Usefulness of seminested multiplex PCR in surveillance of imported malaria in Spain.

The use of a new PCR-based method for the diagnosis of malaria in the Spanish Malaria Reference Laboratory has promoted an increase in confirmed cases of malaria. From August 1997 to July 1998, a total of 192 whole-blood samples and 71 serum samples from 168 patients were received from the hospitals of the Spanish National Health System. Most of the patients came from west-central African countries (85%). This molecular method showed more sensitivity and specificity than microscopy, detecting 12.4% more positive samples than microscopy and 13% of mixed infections undetectable by Giemsa stain. Plasmodium falciparum was the main species detected, with 68% of the total positive malaria cases, followed by Plasmodium malariae (29%), Plasmodium vivax (14%), and Plasmodium ovale (7%), including mixed infections in all cases. This report consists of the first wide, centralized survey of malaria surveillance in Spain. The reference laboratory conducted the analysis of all imported cases in order to detect trends in acquisition. The use of a seminested multiplex PCR permitted confirmation of the origins of the infections and the Plasmodium species involved and confirmation of the effectiveness of drug treatments. This PCR also allowed the detection of the presence in Spain of primaquine-tolerant P. vivax strains from west-central Africa, as well as the detection of a P. falciparum infection induced by transfusion.

Child, Preschool↗
PubMed1999

Five-year analysis of endoscopic retrograde cholangiopancreatography in the Hospital del Bierzo.

OBJECTIVES: endoscopic retrograde cholangiopancreatography (ERCP) is a widely available endoscopic modality, that is not without risks, but is no longer limited to tertiary referral centers. We evaluated the procedure in terms of imaging success, overall therapeutic failure, complications and mortality. METHODS: this retrospective study ran from January 1992 to December 1997. The following data were collected: 1) cannulation rate, 2) failure to obtain images of the duct, 3) type of ERCP, 4) overall therapeutic failure rate and stone extraction, 5) overall complication rate, 6) immediate complications, 7) late complications (within the first 30 days), and 8) mortality. RESULTS: of 425 ERCP procedures performed, all data for 393 were obtained and included in the analysis. The cannulation success was 94%. Failure to obtain a suitable image occurred in 10%. ERCP was diagnostic in 60% and therapeutic in 40%. Sphincterotomy was performed in 83% of the patients. The therapeutic failure rate was 15%. Stone extraction was successful in 69%. The overall complication rate was 8.6%; 2.2% of these complications were severe or fatal. Immediate complications occurred in 4% and late complications in 5.9%. Immediate complications were less frequent in diagnostic ERCP (p < 0.01). Late complications were: pancreatitis (3. 5%), bleeding (1.4%), perforation (0.3%) and cholangitis (0.8%). There was no difference in the frequency of severe pancreatitis between the types of ERCP procedure. Bleeding occurred more frequently in sphincterotomy (p < 0.05). The overall mortality rate was 1.6%. CONCLUSIONS: a continuous audit in each endoscopy unit should be performed to improve ERCP procedures. Diagnostic and therapeutic ERCP carry a similar risk of severe pancreatitis. The bleeding rate was higher in therapeutic ERCP and sphincterotomy.

Bile Duct Diseases↗
PubMed1999

[Investigation of HBV-DNA using the polymerase chain reaction (PCR) in HBsAg-negative, anti-HBc-positive Venezuelan donors].

OBJECTIVE: In our Center the disposal of blood with HBV positive markers is approximately 6%, being 90% AgsHB negative and anti HBc positive. With the purpose of knowing the infected capacities of these donations and to consider the possibility of using them for transfusion, the presence of the viral genoma was investigated by PCR, in a group of samples with these characteristics that were also anti sHB positive. They were correlated with the readings of the anti cHB total, with the anti cHB-IgM and with the titration of the anti sHB. MATERIALS AND METHODS: 87/100 random samples, from February to June 1996, were frozen at -30 degrees C for their later evaluation. In the serological screening were used Auszyme Monoclonal of Abbott and the Heprofile anti cHB, ADI-Diagnostic. The readings of the anti cHB was considered strong, moderate or weak according to its distance to the cut off. For the determination of the anti sHB, Hepanostika anti sHB, Organon Technika was used. They were considered with low titers (< 10 UI/L), high (> or = 10 UI/L) and very high (> or = 100 UI/L). In the determination of the anti cHB-IgM, Heprofile ADI-Diagnostic was used. For the investigation of the viral genoma, it was carried out with double PCR-ADN, using two internal and two external primers for the core-precore region. RESULTS: 70/87 (80.45%) of the samples presented high readings of anti cHB with high titers of anti sHB, being positive for anti cHB-IgM seven of them and one was HBV-ADN positive (1.42%) suggesting the possibility to be cronic carrier. In the remaining 19.55% of the samples we didn't detect positive results in the amplification assays. CONCLUSIONS: 1. The donors showed high levels of immunocompetence. 2. High titer of anti sHB doesn't guarantee the absence of viral genoma and therefore the absence of infectivity can not be sure. This doesn't allow us to come in like donors neither to use their blood in the transfusional therapy.

Blood Donors↗
PubMed1999

[Antithrombotic treatment in non-rheumatic atrial fibrillation. Do we follow the recommendations of clinical trials?].

OBJECTIVES: Several clinical trials have demonstrated that antithrombotic treatment may be effective in prevention of stroke in nonrheumatic atrial fibrillation (AF). The aim of this study was to assess if we follow clinical trial recommendations in community practice. METHODS: We analyzed 225 medical records of patients diagnosed of nonrheumatic AF in Cáceres, during February and March 1998. Patients who were contraindicated to follow antiagreggation or anti-coagulation treatment were excluded. We compared patients with and without antithrombotic treatment with different demographic characteristics and embolic risk factors. RESULTS: 205 patients were included in the study, 149 (72.6%) had high embolic risk. 62 (30.2%) followed anticoagulation, 94 (45.8%) antiaggregation treatment, 5 (2.4%) both treatment and 49 (24%) were not receiving therapy. We didn't findings differences between age, sex, presence of ischemic heart disease, hypertension and congestive heart failure in last three months compared with the patients in respect to the group of patients with anticoagulation and antiaggregation therapy or without it. We determinate as well that previous stroke and echocardiographical finds (valve disease, valve calcification, ventricular dysfunction) were more frequent in the anticoagulation and antiaggregate patients than in those without therapy. CONCLUSION: A high range of nonrheumatic AF patients take any kind of antithrombotic preventive therapy, though a great number of patients with high embolic risk could still get benefits from anticoagulation therapy. We should considerate in the therapy assessment some other clinical characteristics as hypertension, isquemic heart disease and heart failure apart from echocardiographical findings.

Aged↗
PubMed1999

[Atypical primary biliary cirrhosis or autoimmune cholangitis?].

The term autoimmune cholangitis is used for a disease with clinical and pathological features of primary biliary cirrhosis (PBC), lack of anti-mitochondrial antibodies (AMA), presence of anti-nuclear antibodies (ANA), and good response to immunosuppresive therapy. The current knowledge of this condition is limited and it is not established whether or not it is a different syndrome from the CBP. We report a 51-year-old woman with chronic cholestasis, histological features of PBC, negative AMA and positive peripheral fluorescent ANA pattern, without response to prednisone.

Antibodies, Antinuclear↗
PubMed1998

[Subtyping panic disorders according to their symptoms].

BACKGROUND: Panic disorder (PD) is a common illness associated with high levels of disability and with a high utilisation of non-psychiatric health services which is inefficient in most cases. A better understanding of the clinical subtyping of PD may improve diagnosis both in psychiatric and medical settings. The present study is aimed at assessing the frequency, factorial grouping and comorbidity of PD symptoms in a naturalistic sample of patients. PATIENTS AND METHODS: All consecutive cases of PD (n = 442) who contacted with two outpatient clinics in Barcelona (Spain) were assessed by two experienced interviewers. Assessment instrument included SCID-UP-R interview and inventory of panic symptoms based on DSM-III-R. RESULTS: Palpitations (86.7%), shortness of breath (76.5%), fear of dying (69.9%) and dizziness (63.6%) were the most frequent and intense symptoms reported by the PD patients. The principal component analysis revealed four factors which explained the 56% of the variancel "cardiorespiratory" (23.2%), "depersonalization-derealization" (15.8%), "vestibular" (10%) and "mixed" (7%). CONCLUSIONS: The frequency of presentation of symptoms was similar to other studies. However some disimilarities appeared that may be attributed to transcultural differences as well as terminological problems and the range of symptoms assessed. Factors found in the present study support the clinical subtyping of PD in 3 groups characterised by cardiorespiratory symptoms and fear of dying, cognitive symptoms (depersonalization-derealization) and vestibular symptoms such as dizziness and faintness.

Adult↗
PubMed1998

Acrosome reaction inactivation in sea urchin sperm.

Acrosome reaction inactivation (ARI) is a process that renders sperm irreversibly refractory to the egg jelly (the natural inducer of the acrosome reaction, AR). This process triggered by the egg jelly, is associated with an increase in [Ca2+]i. However, we show here that a rise in [Ca2+]i alone is not sufficient to induce ARI, since artificially increasing [Ca2+]i with either an ionophore or rising external pH, does not trigger ARI. Contrary to the AR which strictly requires Ca2+, ARI can be triggered almost equally well by Sr2+. On the other hand, Mn2+ inhibits ARI and, as we showed earlier, does not affect AR. These observations indicate that the mechanisms involved in ARI differ from those leading to AR. In addition, we report here that high external pH (a non-physiological inducer of AR) triggers the AR in previously inactivated sperm by opening the same Ca2+ channels activated by the egg jelly. Considering that the opening of Ca2+ channels is one of the earliest responses triggered by the egg jelly and that ARI requires the egg jelly receptor to be activated, we have concluded that ARI involves the uncoupling between the egg jelly receptor and Ca2+ channels. Furthermore, intracellular pH (pHi) determinations, in the presence or absence of ionomycin to substitute for the uncoupled Ca2+ channels, indicate that pHi regulation is also impaired in inactivated sperm. In conclusion, ARI is a manifestation of the uncoupling of the egg jelly receptor from the different ion transport systems required for the acrosome reaction.

Acrosome↗