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Biomedical subjects

A Ferrer

Publications and source records attributed to A Ferrer.

At least 109 records · Page 6Linked to original sources

[Botulinum A toxins in the treatment of spasticity in cerebral palsy during childhood].

We evaluated the safety and efficacy of Botulinum- A toxin (BTX) in patients with equinus deformity associated with cerebral palsy (CP). We prescribed BTX to six patients (all of whom had previously participated in a multicenter, randomized, double blind study of the same drug); treatment continued for at least 15 months. Four children showed striking improvement, being converted from toe-toe to consistent or occasional heel-toe gait. No side effects were observed. BTX appears to be safe and effective in patients with CP.

Adolescent↗

Bacterial expression of the catalytic domain of 3-hydroxy-3-methylglutaryl-CoA reductase (isoform HMGR1) from Arabidopsis thaliana, and its inactivation by phosphorylation at Ser577 by Brassica oleracea 3-hydroxy-3-methylglutaryl-CoA reductase kinase.

The catalytic domain of 3-hydroxy-3-methylglutaryl-CoA reductase isoform 1 (HMGR1cd) from Arabidopsis thaliana has been expressed in Escherichia coli in a catalytically active form and purified. The high efficiency of the bacterial expression system together with the simplicity of the purification procedure used in this study resulted in the attainment of large quantities of pure enzyme (about 5 mg/l culture) with a final specific activity of up to 17 U/mg. This specific activity is higher than that reported to date for any 3-hydroxy-3-methylglutaryl-CoA reductase (HMGR) purified from a plant source. HMGR1cd activity was completely blocked by the HMGR inhibitor mevinolin (IC50 = 12.5 nM). No significant differences were observed between the Km values of HMGR1cd for NADPH (71 +/- 7 microM) and (S)-3-hydroxy-3-methylglutaryl-CoA (8.3 +/- 1.5 microM) and those of pure HMGR preparations obtained from different plant sources. The purified HMGR1cd was reversibly inactivated by phosphorylation at a single site by Brassica oleracea HMGR kinase A, which is functionally related to the mammalian AMP-activated protein kinase. The site of phosphorylation is Ser577 in the complete sequence of A. thaliana HMGR1. The results in this paper represent the first evidence that a higher plant HMGR is regulated by direct phosphorylation, at least in a cell-free system. Our results also reinforce the view that the AMP-activated protein kinase/SNF1 family is an ancient and highly conserved protein kinase system.

AMP-Activated Protein Kinases↗

Recent epidemics of poisoning by pesticides.

The mechanisms of production of collective poisoning by pesticides have been contamination of foods consumed by man, cutaneous contact and occupational exposure. It is possible to distinguish 4 groups of alimentary epidemics: (1) contamination during transport or storage; (2) ingestion of seed dressed for sowing: (3) use of pesticides in food preparation because of their organoleptic similarity to alimentary products; (4) presence of pesticides in water or food owing to unsafe use of pesticides. Occupational exposure affects clusters of workers in pesticide manufacture, pesticide application and crop management. Some episodes of every kind of the mentioned groups have been published recently.

Food Contamination↗

Lower respiratory tract infections following cardiac arrest and cardiopulmonary resuscitation.

All episodes of lower respiratory tract infection that developed among 96 patients surviving for > 24 hours after cardiac arrest were prospectively studied over an 18-month period. Pneumonia developed in 23 (24.0%) of patients after a mean of 7 days (SD, +/- 6.2 days). The development of four superinfections raised the cumulative incidence to 28.1%. Purulent tracheobronchitis was diagnosed in three instances. The causative agent of pneumonia was identified in 18 episodes, three of which were polymicrobial. Gram-positive cocci represented 57.1% of isolates, and Staphylococcus aureus--the most frequently isolated microorganism in this population--accounted for two-thirds of all gram-positive cocci. Pseudomonas aeruginosa was isolated in six episodes, five of which were associated with previous antibiotic use. Nine (39.1%) of the 23 patients in the group with pneumonia died, but only one of these deaths was considered to be directly related to pneumonia. In conclusion, pneumonia is a common complication of patients surviving cardiac arrest, but, with adequate treatment, its influence on outcome is marginal. Gram-positive cocci are the predominant pathogens, although infection with P. aeruginosa should be considered among patients receiving antibiotics.

Bronchitis↗

Pattern of tracheal colonization during mechanical ventilation.

The relationship between gastric (GC) and tracheal (TC) colonization and the development of ventilator-associated pneumonia (VAP) remains controversial. TC, GC, and pharyngeal (PC) colonization were studied serially in 80 patients with mechanical ventilation (MV) to ascertain the routes and onset of TC. Simultaneous sample from pharynx, stomach, and trachea were obtained throughout the MV period. Quantitative cultures were performed. Seventy-two patients (90%) had TC at some time during MV. Only 19 patients presented TC after PC or GC by the same microorganisms. Indigenous gram-negative and gram-positive microorganisms colonized mainly the trachea from the start of or during MV without previous PC or GC (p < 0.05). Pseudomonas were the microorganisms causing TC principally during MV without previous PC or GC (p < 0.005). Enterobacteria produced TC without a preferential route. Of the 12 patients who developed VAP, the microorganisms responsible had already colonized the trachea in 10 patients. Only 10 of the 21 microorganisms isolated in VAP had previously colonized the pharynx or stomach. In summary, although some microorganisms have preferential routes for producing TC, the microorganisms isolated frequently change during MV. TC precedes VAP in most patients, but only a minority develop a VAP; therefore, together with TC other factors must be involved in VAP development.

Adult↗

Effects of single and chronic treatment with tranylcypromine on extracellular serotonin in rat brain.

We have examined the effects of tranylcypromine, a monoamine oxidase inhibitor used as antidepressant, on the tissue and extracellular concentration of serotonin (5-hydroxytryptamine, 5-HT) and 5-hydroxyindoleacetic acid (5-HIAA) in frontal cortex and dorsal raphe nucleus using microdialysis in conscious rats. Single treatment with tranylcypromine sulphate (0.5, 3 and 15 mg/kg, i.p.) dose dependently elevated dialysate 5-HT in both areas but more markedly in the DRN. Extracellular and tissue 5-HT concentrations were affected by the drug in a different manner. The former increased sharply when tissue 5-HT reached a plateau. This may have reflected saturation of intracellular stores and overflow of the amine. In contrast, tissue and extracellular 5-HIAA concentrations--that indicate metabolic effects of tranylcypromine--were affected similarly. A 2-week treatment with 0.5 mg/kg.day of tranylcypromine sulphate increased basal extracellular 5-HT in frontal cortex and dorsal raphe nucleus (ca. 220%) whereas a further injection of 0.5 mg/kg was without effect in both areas. Thus, chronic, but not acute, treatment with low doses of tranylcypromine increases extracellular 5-HT concentration, suggesting that clinical effects of this monoamine oxidase inhibitor are related to its capacity to enhance serotonergic transmission.

Analysis of Variance↗

Molecular characterization of a fourth isoform of the catalytic subunit of protein phosphatase 2A from Arabidopsis thaliana.

We have recently reported the existence of multiple isoforms of the catalytic subunit of protein phosphatase 2A (PP2A) in Arabidopsis thaliana and the molecular cloning of cDNAs encoding three of these proteins (PP2A-1, PP2A-2, PP2A-3). The reported cDNA encoding PP2A-3 was truncated at the 5' terminus, lacking a short fragment of the N-terminal coding sequence. We have now isolated a near full-length cDNA encoding the entire PP2A-3 protein (313 residues). The clone includes 188 nucleotides of 5'-untranslated region, where a 44 bp long poly(GA) track is found. We also describe the cloning of a cDNA encoding a fourth isoform of PP2A (PP2A-4). The polypeptide contains 313 residues being 98% identical to PP2A-3 and only 80% identical to both PP2A-1 and PP2A-2. The mRNA for PP2A-4 is 1.4 kb in length and, although predominantly expressed in roots, it is also found in other organs. It is concluded that in A. thaliana the isoforms of PP2A can be grouped in two extremely conserved subfamilies.

Amino Acid Sequence↗

The evolution of tuberculosis infection among schoolchildren in Barcelona and the HIV epidemic.

SETTING: First grade students in primary schools in the city of Barcelona, Spain. OBJECTIVE: To estimate the prevalence of tuberculin reaction and sources of infection; to analyse trends in comparison with previous data. DESIGN: Tuberculin screening of first grade schoolchildren (1985 birth cohort) was undertaken in 1991-92 using 2 TU of PPD RT23. RESULTS: The prevalence of reactors among the 12,007 children tested from the 1985 cohort was 0.87%, varying among districts between 0.13% and 3.03%. Follow-up of positive tests was completed for 75 children, which led to the identification of 6 cases of previously unknown clinical tuberculosis among these children, while for 14 infected children index cases were found, one of whom was a confirmed HIV-infected IVDU. CONCLUSION: The comparison of results with data from previous studies suggests that tuberculosis infection among schoolchildren in Barcelona may not be declining as in previous years, especially in areas such as the inner city, where poverty combines with HIV infection and with increasing migration from countries with a higher tuberculosis prevalence.

Child↗

Bacterial pneumonia in HIV-infected patients: a prospective study of 68 episodes.

We collected clinical and microbiological observations, as well as follow-up on human immunodeficiency virus (HIV)-infected patients with bacterial pneumonia, and compared pneumococcal pneumonia in patients with and without HIV infection. Fifty five HIV-infected patients, who had had 68 episodes of bacterial pneumonia, were studied prospectively. Twenty one HIV-infected patients with pneumococcal pneumonia were compared to 69 non-HIV-infected patients with pneumococcal pneumonia. Aetiological diagnosis was established in 48 cases (71%). The most common causative agents were S. pneumoniae and H. influenzae. Sixty percent of episodes took place in asymptomatic carriers of HIV infection and 37% in acquired immune deficiency syndrome (AIDS) patients. Overall mortality was 10%. Fifty five percent of patients with follow-up had recurrent episodes. Bacteraemic pneumococcal pneumonia was more frequent in HIV- than in non-HIV-infected patients, and the mortality of pneumococcal pneumonia was also higher in HIV- (19%) than in non-HIV-infected (4.3%) patients. We conclude that bacterial pneumonia is a frequent problem in HIV-infected patients and that recurrent episodes are common. The clinical presentation of pneumococcal pneumonia is generally indistinguishable from that occurring in normal hosts, but bacteraemia is more common and the mortality is higher in HIV-infected patients.

AIDS-Related Opportunistic Infections↗

[Bronchiolitis obliterans organizing pneumonia: the usefulness of the transbronchial biopsy as a diagnostic technic].

Bronchiolitis obliterans organizing pneumonia (BOOP) is a recently described entity characterized by cough, fever and dyspnea. To date, only a few cases have been published in the literature. Currently, the diagnosis is established by open lung biopsy. We hereby present a case of BOOP diagnosed through transbronchial biopsy (TBB); we discuss the potential benefits of the thoracic radiography and computerized tomography scan (CT scan). Finally, we underline that in our patient, the bronchoalveolar lavage fluid (BAL) restored to normal before the resolution of the radiological images.

Biopsy↗

[Isolation of Haemophilus spp. from samples of pleural fluid: 11 years' review].

BACKGROUND: The incidence and significance of Haemophilus spp. in plural fluid were retrospectively studied over a period of 11 years. METHODS: Gram staining and culture in aerobic and anaerobic media was performed in 7517 pleural fluids. Haemophilus spp. was identified with the AMS-Vitek and/or conventional systems. The presence of beta-lactamase was assessed by this method or by the acidometric method. RESULTS: Haemophilus spp. was identified in 72 samples (0.9%) corresponding to 37 patients. The medical records of 22 were reviewed. The most common species isolated was H. influenzae. Gram stain exam was positive on 28 occasions (38.8%), with gram-negative bacilli being observed in 78.5%. A pure culture was obtained in 43 samples with anaerobic bacteria associated in 18% of the cases. Only 10 strains (16.4%) produced beta-lactamase. No predominance of any determined biotype was observed. Most of the patients were male with a mean age of 59.2 years (range: 2-82). Seventeen patients presented with community-acquired pneumonia, as well as tuberculous sequelae, pneumonectomy and pulmonary and/or upper GI truct neoplasms. All were treated with antibiotics, beta-lactam drugs alone or with aminoglycosides. Half of them also required surgical drainage. Four patients died in relation with the underlying disease. CONCLUSIONS: Haemophilus spp. was isolated in 7.7% of 7517 samples of pleural fluid. This finding may indicate the coexistence of an underlying thoracic disease of neoplastic origin.

Adolescent↗

Protein phosphatases in higher plants: multiplicity of type 2A phosphatases in Arabidopsis thaliana.

Two DNA fragments, AP-1 and AP-2, encoding amino acid sequences closely related to Ser/Thr protein phosphatases were amplified from Arabidopsis thaliana genomic DNA. Fragment AP-1 was used to screen A. thaliana cDNA libraries and several positive clones were isolated. Clones EP8a and EP14a were sequenced and found to encode almost identical proteins (97% identity). Both proteins are 306 amino acids in length and are very similar (79-80% identity) to the mammalian isotypes of the catalytic subunit of protein phosphatase 2A. Therefore, they have been designated PP2A-1 and PP2A-2. A third cDNA clone, EP7, was isolated and sequenced. The polypeptide encoded (308 amino acids, lacking the initial Met codon) is 80% identical with human phosphatases 2A and was named PP2A-3. The PP2A-3 protein is extremely similar (95% identity) to the predicted protein from a cDNA clone previously found in Brassica napus. Southern blot analysis of genomic DNA using AP-1 and AP-2 probes, as well as probes derived from clones EP7, EP8a and EP14a strongly indicates that at least 6 genes closely related to type 2A phosphatases are present in the genome of A. thaliana. Northern blot analysis using the same set of probes demonstrates that, at the seedling stage, the mRNA levels for PP2A-1, PP2A-3 and the gene containing the AP-1 sequence are much higher than those of PP2A-2 and AP-2. These results demonstrate that a multiplicity of type 2A phosphatases might be differentially expressed in higher plants.

Amino Acid Sequence↗

Identification and molecular cloning of two homologues of protein phosphatase X from Arabidopsis thaliana.

In a recent paper [Ariño et al., Plant Mol Biol 21: 475-485 (1993)] we reported the amplification of a DNA fragment (AP-2) from the genome of Arabidopsis thaliana encoding an amino acid sequence corresponding to a Ser/Thr protein phosphatase distantly related to type 2A protein phosphatases. In this paper we report the use of the AP-2 fragment to isolate several cDNA clones from a leaf cDNA library. Two of these (EP124 and EP129) largely overlap and contain the AP-2 sequence, whereas a third clone (EP128) is different although very related in sequence (86% of identity). Clones EP124/EP129 and EP128 were found to encode two highly related polypeptides (93% identity) of 305 residues, showing a very high identity (83%) to the catalytic subunit of protein phosphatase X (PPX) from rabbit. Therefore, they have been named PPX-1 (EP124/EP129) and PPX-2 (EP128). Southern blot analysis of genomic DNA indicates that only these two genes encoding phosphatases closely related to PPX are present in the genome of A. thaliana. Both PPX-1 and PPX-2 are expressed at very low levels in A. thaliana flowers, leaves, stems and roots. The expression levels of four previously identified type 2A phosphatases are higher than those of PPX genes. PP2A-1 appears to be the major mRNA species detected in all the tissues analyzed.

Amino Acid Sequence↗