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Biomedical subjects

A García

Publications and source records attributed to A García.

At least 163 records · Page 9Linked to original sources
PubMed1999

Resistance of initiation factor 2 (eIF-2alpha) kinases to staurosporine: an approach for assaying the kinases in crude extracts.

We studied the effect of staurosporine on two well characterised mammalian eIF-2alpha kinases, the heme-regulated translational inhibitor (HRI), and interferon-inducible double-stranded RNA-activated protein kinase (PKR). Both pure eIF-2 and a synthetic peptide used to measure the activity of purified or immunoprecipitated enzymes (sequence ILLSELSRRRIRAI) were phosphorylated with purified enzymes and crude preparations of tissues or cells in the presence of the inhibitor. In the presence of 0.25 microM staurosporine (a concentration which completely inhibits a wide range of Ser/Thr protein kinases), the phosphorylation of eIF-2alpha by HRI and PKR was not inhibited. The lack of response of eIF-2alpha kinases to staurosporine allowed us to measure PKR activity in salt washed postmicrosomal supernatants without previous purification of the enzyme. In the presence of poly(I):poly(C), the PKR activator, we detected both an increased phosphorylation of eIF-2alpha and an increment in the autophosphorylation of PKR. We also confirmed an induction of PKR in cultured neuronal cells after treatment with interferon. The results obtained following phosphorylation of the synthetic peptide with crude extracts are less conclusive. Although its phosphorylation is specific because it displaces eIF-2 phosphorylation, and the presence of staurosporine prevents its phosphorylation by other serine/threonine kinases, it is a rather poor substrate for PKR.

Animals↗
PubMed1999

McArdle's disease associated with homozygosity for the missense mutation Gly204Ser of the myophosphorylase gene in a Spanish patient.

We studied a pateint whose clinical, morphological and biochemical findings were consistent with McArdle's disease. Molecular genetic studies revealed that the patient did not harbor the common Arg49Stop mutation and was homozygous for the Gly204Ser mutation. Until now, no patient having the missense mutation in the two alleles has been documented.

Adult↗
PubMed1999

Phenolic compounds in Spanish olive oils.

Phenolic compounds in Spanish virgin olive oils were characterized by HPLC. Simple phenols such as hydroxytyrosol, tyrosol, vanillic acid, p-coumaric acid, ferulic acid, and vanillin were found in most of the oils. The flavonoids apigenin and luteolin were also found in most of the oils. The dialdehydic form of elenolic acid linked to tyrosol and hydroxytyrosol was also detected, as were oleuropein and ligstroside aglycons. The structure of a new compound was elucidated by MS and NMR as being that of 4-(acetoxyethyl)-1,2-dihydroxybenzene. Changes of phenolic compounds in virgin olive oils with maturation of fruits were also studied. Hydroxytyrosol, tyrosol, and luteolin increased their concentration in oils with maturation of fruits. On the contrary, glucoside aglycons diminished their concentration with maturation. No clear tendency was observed for the rest of the phenolic compounds identified.

Chromatography, High Pressure Liquid↗
PubMed1999

Oxidative stress induced by copper in sunflower plants.

The toxic effect of copper was evaluated in sunflower plants by means of root elongation, lipid peroxidation and antioxidative enzyme activities. Plants were grown under controlled environmental conditions in hydroponic culture for two weeks and exposed to different copper concentrations for an additional week. Determinations were performed in both roots and leaves. From the results of the root elongation test, a copper concentration of 10 microM was found to be toxic for sunflower plants causing lipid peroxidation and, thus, oxidative stress. Antioxidative enzymes (peroxidase and superoxide dismutase) responded at lower, nontoxic copper concentrations.

Antioxidants↗
PubMed1999

Normal esophageal function after myotomy in a patient with idiopathic diffuse esophageal spasm.

A 52-year-old man with idiopathic diffuse esophageal spasm and hypertensive lower esophageal sphincter presented with dysphagia for several years. After unsuccessful therapy with forceful pneumatic dilation of the cardia, a myotomy of the cardia and distal esophagus was performed. The patient became asymptomatic, lower esophageal sphincter pressure diminished to less than 10 mm Hg, and esophageal body motor activity was normalized. This situation remains unchanged 6 years after the operation.

Cardia↗
PubMed1999

Usefulness of PCR and antigen latex agglutination test with samples obtained by transthoracic needle aspiration for diagnosis of pneumococcal pneumonia.

In a large number of cases, the etiology of community-acquired pneumonia (CAP) is not established. Some cases are probably caused by Streptococcus pneumoniae. Transthoracic needle aspiration (TNA) culture has a limited sensitivity which might be improved by antigen detection or gene amplification techniques. We evaluated the capacity of a PCR assay and a latex agglutination test to detect S. pneumoniae in samples obtained by TNA from 95 patients with moderate-to-severe CAP. Latex agglutination and PCR had sensitivities of 52.2 and 91.3%, specificities of 88.7 and 83.3%, positive predictive values of 62.3 and 65.6%, and negative predictive values of 83.3 and 96.5%, respectively, when culture techniques were used as the "gold standard." When we considered expanded criteria for the diagnosis of pneumococcal pneumonia as a standard for our calculations, latex agglutination and PCR had sensitivities of 53.6 and 89.7%, specificities of 93.0 and 90.0%, positive predictive values of 78.9 and 81.3%, and negative predictive values of 80.3 and 94.7%, respectively. The additional diagnosis provided by the PCR assay compared to latex agglutination was 12.2% (95% confidence interval of the difference from 0.4 to 20. 1%). PCR was more sensitive than TNA culture, particularly in patients who had received prior antibiotic therapy (83.3 versus 33. 3%). Although PCR is a very sensitive and specific technique, it has not proved to be cost-effective in clinical practice. Conversely, latex agglutination is a fast and simple method whose results might have significant implications for initial antibiotic therapy.

Antibodies, Bacterial↗
PubMed1999

Lactation curves in captive Iberian red deer (Cervus elaphus hispanicus).

This study examines milk production and the effect of milk production and sex of calf on body weights and gains of red deer calves and hinds of the Iberian subspecies (Cervus elaphus hispanicus). Milk production was assessed in 14 hinds by weighing calves before and after suckling and by adjusting these values to the Gamma function. Gamma estimates of total milk production up to d 105 were similar to the amounts computed directly from double weighing. Hinds showed two types of lactation curve: 1) the standard mammal lactation curve, with an asymmetrical peak at wk 2 to 4 (Type I) and 2) decreasing curves with no peak (Type II). Although there was great interindividual variability, hinds with Type I curves showed a trend to produce more milk than those with Type II. The type of curve did not seem to affect weight variables of the calf or those of the dam. Calves that gained more weight consumed greater amounts of milk (P<.05). Males were heavier than females at birth (P<.05), but males did not differ from females in their weight at 105 d, milk consumption, and gain. Gender did not affect hind weight, but dams of male calves showed a trend to be lighter (P = .063) at d 105 than dams of female calves. Our results suggest that suckling differences found in other studies between male and female calves may not involve differences in milk production, although other rearing costs seem to affect hind weight losses. They also suggest that the curve type may not depend only, as reported, on the nutrition plane.

Animals↗
PubMed1999

[Stapedectomy versus stapedotomy. Our experience].

Otosclerosis surgery has seen three well-differentiated stages of development: a) SHC fenestration; b) stapes mobilization, and c) platinectomy, a procedure introduced in 1960 by Shea. Since then, only one variation has been proposed: platinotomy. After a comparative study of platinectomy versus platinotomy, we, like other authors, concluded that platinotomy was a better technique because of the ease of execution and good functional results.

Adolescent↗
PubMed1999

[Myocardial perfusion scintigraphy with 99mTC-sestamibi and gated SPECT and myocardial perfusion scintigraphy with reinjection of 201Tl at 24 hours. Are the techniques comparable?].

AIM: To compare the results obtained with 99mTc-sestamibi and gated-SPECT (gated SPECT in stress and rest) with 201Tl (stress, redistribution, and 24 hour reinjection SPECT). METHODS: Twenty patients underwent two SPECT studies, one with 201Tl and the other with 99mTc-sestamibi. RESULTS: Using 201Tl as a reference, 177 segments were considered normal, 31 viable and 32 with myocardial necrosis. The overall concordance with 99mTc-sestamibi was 84.2%. In the subgroup of defects that improved after reinjection of 201Tl, it was much less (45%), even after wall thickness and movement (55%) were analyzed. CONCLUSION: The overall concordance between 201Tl scintigraphy compared to 99mTc-sestamibi is acceptable. Correlation is low in the viable segments with 99mTc-sestamibi, even after analyzing the Gated-SPECT.

Adult↗
PubMed1999

Nitric oxide-independent down-regulation of soluble guanylyl cyclase by bacterial endotoxin in astroglial cells.

Induction of nitric oxide (NO) synthase (NOS) type 2 (NOS-2) in glial cells after exposure to bacterial endotoxin [lipopolysaccharide (LPS)] or inflammatory cytokines has been repeatedly demonstrated both in vitro and in vivo. However, little is known about effects of these agents on NO-dependent cyclic GMP (cGMP) formation. In this work, we show that treatment of rat cerebellar astrocyte-enriched primary cultures with LPS decreases NO donor-stimulated cGMP formation with a similar initial time course (up to 9-12 h) and concentration dependency (0.1-1 ng/ml) as for induction of NOS-2. This effect appears to be due to a down-regulation of soluble guanylyl cyclase (sGC) because LPS treatment decreases sGC activity and sGC beta1 subunit levels. In contrast, cGMP phosphodiesterase activity and stimulation of the particulate guanylyl cyclase by atrial natriuretic peptide are not affected. Incubation of astroglial cultures with a transcription inhibitor (actinomycin D) or a protein synthesis inhibitor (cycloheximide) for 18-20 h does not decrease sGC activity but totally prevents LPS-induced desensitization of sGC. Inhibition of NOS-2 activity with N(G)-monomethyl-L-arginine or inhibition of NOS-2 induction with the synthetic glucocorticoid dexamethasone failed to prevent the inhibitory effect of LPS on sGC, indicating that NO production is not involved. Moreover, after removal of LPS the time for recovery of sGC responsiveness is much longer than that for NOS-2 return to basal levels. LPS impairment of cGMP formation also occurs in cortical astrocytes but not in cerebellar granule neurons. The decreased responsiveness of sGC to NO stimulation following LPS challenge may prevent inappropriate astroglial cGMP signaling caused by excess production of NO by adjacent activated glial cells. Key Words: Astroglia-Neurons-Nitric oxide-Soluble guanylyl cyclase-Lipopolysaccharide.

3',5'-Cyclic-GMP Phosphodiesterases↗
PubMed1999

[Treatment of severe scrotal hypospadias with onlay-type urethroplasty using mouth mucosa].

Failure in repairing severe hypospadias complicated with fistula and cutaneous retraction is often associated with lack of subcutaneous tissue and skin providing protection to the neourethra. We report the results of treatment in 6 patients with scrotal hypospadias with severe deviation and scarce dorsal prepuce. A neourethra was created by the onlay technique applying an oral mucosa graft and preserving in all cases the dorsal preputial skin for the island cutaneous flap. All patients had hypospadias without previous repairs excepting one of them, who had had one first time hypospadias repair in other hospital. Patients age ranged between 2 years and 3 months, and 4 years (mean: 2 years and 9 months). In all cases, hypospadias was scrotal type with severe deviation and scarce dorsal prepuce. All patients had prior hormone stimulation with dehydrotestosterone 3%. Surgical repair was performed in one-stage. Urethroplasty included preservation of the urethral plate, oral mucosa graft to provide ventral coverage, and island cutaneous flap with the dorsal preputial skin. In all cases, the chord was dissected behind the urethral plate. In 3 patients a dorsal Nesbit plication was necessary to obtain a complete straighten penis. Results in all 6 cases were satisfactory. Only one patient had a small leakage at the previous neomeatus. The other five patients are asymptomatic. Follow-up ranges from 6 months to 2 years. We conclude that urethroplasty in association with a well vascularized island flap of dorsal preputial skin decrease the incidence of fistulae. In patients with severe hypospadias with scarce dorsal prepuce urethroplasty should be completed with oral mucosa grafts preserving dorsal preputial skin for the ventral cutaneous plasty.

Child, Preschool↗
PubMed1999

[Seroepidemiology of Bartonella henselae infection in HIV-infected patients].

BACKGROUND: Bartonella henselae infections are closely related to numerous clinical infections of growing interest in Spain. Since immunosuppressed patients are a potential risk group for infection by this bacteria, the aim of the present was to study the seroepidemiology of B. henselae infection in a risk group (patients with HIV infection) and in a control group (donors). PATIENTS AND METHODS: In October, 1997, antibodies versus B. henselae were determined at different dilutions (cut off > or = 1:64) by immunofluorescence in 52 patients with HIV infection and 85 donors. An epidemiologic study included age, sex, smoking, alcohol intake, INVDA, HIV infection, AIDS stage, cutaneous anergy, CD4 lymphocyte count, antiretroviral treatment and chemoprophylaxis versus P. carinii. RESULTS: Nine of the patients with HIV infection (17.3%) and five donors (5.88%) presented titers > or = 1:64 with no significant differences (p = 0.06) (adjusted OR: 1.7; CI 95%: 0.34-8.54). Moreover, multiple logistic regression analysis did not show any risk or protection factor associated with B. henselae infection in patients with HIV infection. CONCLUSIONS: A high level of seroprevalence of antibodies versus B. henselae was observed in patients with HIV infection. No risk or protection factors associated with B. henselae infection in patients with HIV infection were found.

Adult↗
PubMed1998

The Bcl-2 gene is differentially regulated by IL-2 and IL-4: role of the transcription factor NF-AT.

The murine TS1alphabeta T cell line expresses the anti-apoptotic protein Bcl-2 upon IL-2 stimulation, whereas IL-4-mediated growth of this cell line proceeds in the absence of Bcl-2 expression. In addition, IL-4 stimulation inhibits Bcl-2 expression and modulates its mRNA level. IL-2-induced DNA binding activity for these transcription factors is sensitive to phosphatidylinositol 3 kinase inhibitor wortmannin and to Rho inhibitor Clostridium difficile toxin B, which inhibit IL-2-induced Bcl-2 expression. NF-AT transcription factor appears to be the most important in the control Bcl-2 expression, since inhibition of the calcium-calmodulin-dependent phosphatase calcineurin, which regulates NF-AT activity, downregulates Bcl-2 expression in IL-2-stimulated cells. Constitutive expression of this phosphatase also upregulates Bcl-2 expression in IL-4-stimulated cells. In addition, a dominant negative NF-AT expression vector downregulates Bcl-2 expression in IL-2-stimulated cells. These results suggest that IL-2 induction of Bcl-2 expression may be directly or indirectly mediated by NF-AT.

Androstadienes↗
PubMed1998

Proportional morbidity rates of enteropathogens among diarrheic dairy calves in central Spain.

Faecal samples from 218 diarrheic dairy calves in 65 dairy herds, selected by convenience, were screened for the presence of rotavirus, coronavirus, Cryptosporidium spp., F5+ Escherichia coli and Salmonella spp. Animals surveyed were from 1 to 30 days old. Cryptosporidium and rotavirus were the most commonly detected agents (52.3% and 42.7% of the samples positive, respectively). F5+ E. coli was detected in the faeces of 11.9% of the calves and bovine coronavirus was detected in the faeces of 7.3% of the calves. Salmonella spp. was only found in the faeces of two calves (0.9%). Mixed infections with two or more agents occurred in 28% of the calves. Concurrent infection of rotavirus and Cryptosporidium was found in 21.6% of the calves. Two tests were used for the detection of rotavirus (a commercial ELISA and PAGE), F5+ E. coli (ELISA and bacterial culture) and Cryptosporidium (ELISA and microscopy). The validity of the commercial ELISA for the detection of rotavirus, F5+ E. coli and Cryptosporidium in faeces from diarrheic calves was evaluated using PAGE, bacterial culture and microscopy as gold standard, respectively. The ELISA showed a very low sensitivity (28.6%) for the detection of F5+ E. coli compared to bacterial culture.

Animals↗
PubMed1998

[Heart rate variability during the first 24 hours of acute myocardial infarction].

BACKGROUND: To evaluate the heart rate variability (HRV) during the first 24 h after a myocardial infarction (MI), and to study its relationship with other clinical variables and in-hospital follow-up. PATIENTS AND METHODS: 101 patients (age < 80 years) with MI in sinus rhythm were prospectively studied. A Holter monitoring was performed during the first 24 h. The heart rate (HR), standard deviation of RR intervals (SDRR) and the histogram at different levels were analyzed, as well as the mean and standard deviation of RR intervals in an early 5 min record. The results were compared with the clinical characteristics and the in-hospital outcome of the patient. RESULTS: HRV was lower in women, hypertensives and patients who did not receive thrombolytic agents. In patients without heart failure, inferior MI's had lower HR and higher HRV than anterior MI's (SDRR: 52.8 [20.6] and 42.2 [16.9], respectively; p < 0.05). HRV was significantly decreased as Killip group increased, as well as in patients who developed late heart failure. The development of ventricular tachycardia or fibrillation was associated to a low HRV in the 24 h analysis (SDRR: 30.2 [15.6] for the 6 patients with VF/VT vs 46.8 [20.1] for the rest; p < 0.05), as well as in the early 5 min record (29.8 [14.8] and 50.8 [35.8], respectively; p < 0.05). CONCLUSIONS: During the first 24 h after MI the HRV is related to some clinical variables and to MI location (higher in inferior MI). Patients who develop heart failure or ventricular arrhythmias before hospital discharge have a higher HR and a significantly decreased HRV.

Aged↗