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Biomedical subjects

P Rodríguez

Publications and source records attributed to P Rodríguez.

At least 55 records · Page 3Linked to original sources
PubMed1997

Acquired drug resistance in Mycobacterium tuberculosis isolates recovered from compliant patients with human immunodeficiency virus-associated tuberculosis.

We describe five compliant patients with human immunodeficiency virus (HIV)-associated tuberculosis (TB) that relapsed, with acquisition of resistance by the original Mycobacterium tuberculosis strains. Both the first and second isolates from each patient had the same IS (insertion sequence) 6110-based DNA fingerprint patterns. Three of the five patients developed TB that was resistant to rifampin alone; no mutation in the region of the rpoB gene was detected by a line probe assay in two of the isolates from these patients. We discuss several factors presumably associated with acquired drug resistance in HIV-infected patients, including exogenous reinfection, drug interactions, malabsorption of drugs, and the presence of a large organism burden.

AIDS-Related Opportunistic Infections↗
PubMed1997

[Synchronous bilateral renal cell carcinoma].

Until very recently, bilateral renal cell carcinoma was considered to be of very poor prognosis due to the poor results obtained with either radiotherapy or chemotherapy, which were completely ineffective in this type of tumours. In 1952, Krumbach performed the first radical nephrectomy and partial nephrectomy to a patient with bilateral synchronic renal cell carcinoma. This aggressive approach to bilateral renal cell carcinoma definitely changed the prognosis of these patients. Other authors with broad series of patients have clearly demonstrated that aggressive treatment of these tumours is the only approach that can offer patients a life opportunity with a significant 5-year survival ranging between 60-77.8% from the time of surgery.

Carcinoma, Renal Cell↗
PubMed1997

[Megacalycosis complicated with stenosis of the pyeloureteral junction].

Contribution of a case report of megacalycosis in a nine and a half-year old male child, in whom the disorder was diagnosed by our team when he was only four. The intense colic pains experienced by the child together with the isotopic renogram non responsive to seguril typical of obstruction, raised the diagnosis of superimposed stenosis of the pyeloureteral attachment. As a result, an Anderson-Hynes pyeloplasty was performed. Post-operative status after four years is absolutely normal from both a clinical and scintiscan point of view.

Child↗
PubMed1996

Spontaneous rupture of the spleen associated with pneumonia.

Spontaneous rupture of the spleen is a rare and life-threatening complication of bacterial pneumonia, only six properly documented cases having been reported to date. A case of spontaneous splenic rupture associated with pneumonia caused by Legionella pneumophila is presented, together with a review of the literature. Most of the patients were aged over 50, but none had predisposing conditions. Left lung involvement predominated. Legionellosis and Q fever were the most frequent etiologic diagnoses. Empiric antibiotic therapy was adequate in all but two patients. One patient died; he had not undergone laparotomy. Spontaneous rupture of the spleen is an extremely rare complication of bacterial pneumonia that endangers the patient's life if surgery is not performed immediately. This complication should be borne in mind in patients with atypical pneumonia who have left quadrant pain and a falling hematocrit, even in the absence of prior splenomegaly.

Adult↗
PubMed1996

[Usefulness of DR, PGRS, and spoligotyping in the typing of Mycobacterium tuberculosis. Comparison with IS6110].

BACKGROUND: To evaluate 4 markers (IS6110, DR, PGRS and spoligotyping) to differentiate the strains of Mycobacterium tuberculosis isolated in our surroundings, most specially in those which contain a reduced number of IS6110 copies. In addition, to confirm the identity of the strains that share the same IS6110 restriction-hybridization pattern. METHODS: We selected 37 strains from a previous study: 25 had a unique IS6110 pattern and 12 grouped in 3 clusters (8 strains with 11 bands, 2 with 17 bands and 2 which shared the same six-band pattern). The PGRS and DR-RFLPs were obtained by AluI restriction and synthetic oligonucleotides specific to these sequences. The polymorphism of the DR region spacers was analyzed by spoloigotyping. For the amplification of the spacers we used the DRa and DRb primers. Detection was done hybridizing the PCR products on a membrane in which 43 specific spacers had been previously immobilized. RESULTS: Twenty-three different PGRS patterns and 18 spolygotyping patterns were obtained from 25 strains with unique IS6110 pattern. Eight patterns resulted from the 10 strains studied by DR. The 8 strains which shared an 11-band pattern, as well as the 2 strains which shared a 17-band pattern, resulted identical by the other markers. However, 2 strains which shared a 6-band pattern were different by both PGRS and DR or spoligotyping. CONCLUSIONS: 1) IS6110 resulted the most discriminative marker of all. 2) The clonality of clusters with a low number of bands has to be confirmed with alternative markers.

Bacterial Typing Techniques↗
PubMed1996

[Pyomyositis in Zamora].

BACKGROUND: Pyomyositis is a purulent infection involving the skeletal muscle. Although it was initially described in tropical countries, is it ever more frequently found in warm climates. METHODS: A review of the clinical histories of the admission of patients in the Internal and Infectious Medicine Units over the period from May 1992 to April 1994 (1818 admissions) was carried out analyzing those in whom the diagnosis was of pyomyositis. This diagnosis was performed by clinical data and radiologic and microbiologic confirmation. RESULTS: Five patients diagnosed with pyomyositis were found. Of the five cases, four were men with ages ranging from 27 to 64 years. In most of the cases more than one muscle group was involved and only two cases showed predisposing factors (history of injury and DM). The existence of abscesses was shown by echography in 3 cases and by CAT in 2 cases. Staphylococcus aureus was the most frequently isolated microorganism. The five patients underwent medical treatment and surgical treatment was also performed in 2 achieving satisfactory evolution. CONCLUSIONS: Imaging techniques (echography and CAT) effectively contribute to the diagnosis of pyomyositis. Medical treatment, associated with surgery in some cases, achieved satisfactory evolution. The incidence of pyomyositis is probably greater than what has been recognized to date.

Adult↗
PubMed1996

The supra-ependymal innervation is not responsible for the repression of tight junctions in the rat cerebral ependyma.

Classically, the contiguous epithelial cells show intercellular tight junctions (TJ) positioned as a continuous belt of cell-cell contacts at the boundary of apical and basolateral plasma membranes. Among the epithelia, the "typical" cerebral ependyma is very peculiar due to the absence of TJ, in contrast to the ependyma of the circumventricular organs (e.g. choroid plexus and the subcommissural organ) which shows well differentiated TJ. Since the "typical" ependyma is covered in the rat with a plexus of intraventricular nervous fibres not present at the surface of the circumventricular organs, we hypothesized local repression of TJ by molecules (serotonin, GABA, etc.) released by the supra-ependymal varicosities. Neither the denervation of the "typical" ependyma nor the ex vivo activation of protein kinase C (which increases the transepithelial resistance as it has been reported in other epithelia) produced junctional fibrils as shown by freeze-fracture. As the protein ZO-1 was not detectable in the "typical" ependyma by immunocytochemistry, there is probably repression of the genes responsible for TJ biosynthesis by unidentified endogenous factors.

5,7-Dihydroxytryptamine↗
PubMed1996

[Disseminated Mycobacterium genavense infection in patients with HIV infection. Description of 5 cases and review of the literature].

BACKGROUND: Five cases of disseminated infection by Mycobacterium genavense in patients with HIV infection are reported with a review of the literature. MATERIAL AND METHODS: A description of the clinical, epidemiologic and therapeutic characteristics of five cases are presented. The initial isolation of the microorganism was performed in Bactec 13A from blood and bone marrow aspirates. Subcultures were made in different media and the growth characteristics evaluated. Sensitivity to NAP was determined by radiometric techniques and gas chromatography allowed a possible identification. Definitive identification was based on PCR amplification of the gene which codifies the 65kDa protein and the posterior restriction of the amplified fragments by using BstEII and HaeIII. RESULTS: All five patients were males with HIV infection and a lymphocyte count of less than 25 cells/mm3 with an non-specific clinical picture similar to that produced by M. avium complex (MAC). Empiric antiMAC treatment was administered in four of the patients with good clinical response. All five strains were sensitive to NAP. The greatest growth rate was obtained in the subcultures with acid pH in liquid medium. Gas chromatography was very similar to that of M. simiae. Amplification of the gene which codifies the 65 kDa protein and posterior restriction with BstEII resulted in 2 fragments of 325 and 125 bp, while restriction with HaeIII resulted in two fragments of 140 and 105 bp. CONCLUSIONS: Mycobacterium genavense represents 9% of the disseminated infections by mycobacteria in AIDS patients. The clinical manifestations, empiric treatment and response is similar to that of infection by M. avium complex. Growth is favored by acid pH in liquid medium. Susceptibility to NAP leads to possible identification which should be confirmed by molecular techniques.

AIDS-Related Opportunistic Infections↗
PubMed1995

Structural domains of streptokinase involved in the interaction with plasminogen.

Two fragments of recombinant streptokinase, comprising amino acids Val143-Lys293 (17-kDa rSK) or Val143-Lys386 (26-kDa rSK), were cloned and expressed in Escherichia coli, purified to homogeneity and their interactions with plasmin(ogen) were evaluated. Both 17-kDa rSK and 26-kDa rSK bound to plasminogen with a 1:1 stoichiometry and with affinity constants of 3.0 x 10(8) M-1 and 12 x 10(8) M-1, respectively, as compared to 6.3 x 10(8) M-1 for the binding of intact recombinant streptokinase to plasminogen. Binding of 17-kDa rSK to plasminogen-Sepharose was displaced by addition of increasing concentrations of recombinant streptokinase, whereas bound recombinant streptokinase was not displayed by 17-kDa rSK. In equimolar mixtures of plasminogen and 26-kDa rSK, the appearance of amidolytic activity as monitored with a chromogenic substrate, was significantly delayed compared to the equimolar mixture with recombinant streptokinase (60% of the maximal activity after 30 min, compared to maximum activity within < or = 2 min). In contrast, no amidolytic activity was generated in equimolar mixtures of plasminogen and 17-kDa rSK. Plasminogen was rapidly activated by catalytic amounts (1:100 molar ratio) of recombinant streptokinase (60-70% within 10-15 min), whereas only 4% of the plasminogen was activated within 60 min with 26-kDa rSK, and no plasmin was generated with 17-kDa rSK. Complexes of plasmin with 17-kDa rSK or with 26-kDa rSK were very rapidly inhibited by alpha 2-antiplasmin (apparent second-order inhibition rate constant of approximately 2 x 10(7) M-1 s-1), whereas the complex with recombinant streptokinase was resistant to inhibition. With 26-kDa rSK, inhibition by alpha 2-antiplasmin resulted in dissociation of the complexes and recycling of functionally active 26-kDa rSK to other plasminogen molecules; 17-kDa rSK, in contrast, remained associated with the plasmin-alpha 2-antiplasmin complex. These findings suggest that different regions of the streptokinase molecule are involved in binding to plasminogen, in active-site exposure, and in impairment of the inhibition of plasmin by alpha 2-antiplasmin. Thus, the 17-kDa region spanning Val143-Lys293 in streptokinase mediates its binding to plasminogen but does not induce activation. Furthermore, this region does not interfere with the inhibition of the complex with plasmin by alpha 2-antiplasmin.

Amino Acid Sequence↗
PubMed1995

[Cuban epidemic neuropathy. I. Viral isolation].

From the end of 1991 to June, 1993, an epidemic neuropathy affecting 50,963 persons occurred in Cuba. Two clinical forms of the disease were observed: the optic form (with or without peripheral manifestations, 52% of the cases) and the peripheral form (48%). The epidemiological studies revealed nutritional disorders, mainly a vitamin B complex deficiency due to economic difficulties faced by the country in the "special period". Smoking habit and alcohol consumption were identified as risk factors, particularly for the most severe forms of the disease. In the virological studies of the cerebrospinal fluid (CSF) a Coxsackie 9 virus was isolated in Vero cells in 4% of the cases, as well as another agent with mild cytopathogenic effect in 80% of the samples. Sixty seven percent of the CSF samples inoculated to lactating mice caused the disease or the death of the animals. The viral persistence was confirmed in the cerebrospinal fluid during al least 21 days in a group of patients, and for a year in another group.

Animals↗
PubMed1992

High level expression of streptokinase in Escherichia coli.

Streptokinase (SK), which activates human plasminogen by promoting its conversion to plasmin, is normally obtained from beta-hemolytic streptococci. Treatment with SK is an effective therapy for improving survival and preserving left ventricular function after coronary thrombosis. We report the cloning, expression in E. coli to levels of 25% of the total cell protein, and characterization of a novel SK (SKC-2) gene, the product of which is functionally equivalent to the naturally-derived protein. The availability of a recombinant streptokinase (rSK) in high yield and purity offers a potentially attractive alternative source of this important therapeutic agent.

Amino Acid Sequence↗
PubMed1992

[Interdisciplinary ambulatory care in patients with chronic mental disease].

The experience of an ambulatory treatment for mental chronic outpatients is presented. A trans-disciplinary group (including a psychiatrist, an occupational therapist, a social worker, a nurse, and a psychologist) worked during a 3-year period. Five specific clinics were created: Organic Mental Syndrome, Schizophrenia, Mood Disorders, Neurosis, and Psychoactive Substance Users. Results of the treatment are presented, showing the benefits such a clinical envisioning meant not only for the patients involved but also for their family, the hospital management, and the members of the therapeutic group as well.

Ambulatory Care↗
PubMed1992

Purification of streptokinase by affinity chromatography on immobilized acylated human plasminogen.

Streptokinase is an extracellular protein produced by several strains of streptococci. It functions in the species-specific conversion of plasminogen to plasmin. In this paper we describe the purification of streptokinase by affinity chromatography on human plasminogen acylated with p'-nitrophenyl p-guanidinobenzoate. The acylated and non-acylated plasminogen and plasmin were coupled to cyanogen bromide-activated Sepharose 4B and evaluated for streptokinase purification. These results show that a homogeneous preparation of streptokinase with high specific activity and high yield can be obtained using acylated plasminogen. This method permits the binding of one milligram of streptokinase per milliliter of swollen gel.

Acylation↗
PubMed1992

The interaction of monovalent cations with fructose 1,6-bisphosphatase modified by N-ethylmaleimide and its relation with AMP inhibition.

The relationship between derivatization of reactive cysteine residues with N-ethylmaleimide and a partial desensitization of fructose 1,6-bisphosphatase to AMP inhibition was studied. AMP desensitization of the enzyme was found to be dependent on the activity assay conditions used. When the assay was performed in the presence of high levels of monovalent cations (150 mM), the AMP affinity of the enzyme decreased with the chemical modification. The apparent loss of sensitivity toward AMP was accompanied by an uptake of 1 mole of N-ethylmaleimide/mole of enzyme subunit. However, the modified enzyme did not show alteration in AMP inhibition in the absence of K+. Evidence was obtained that K+ induces a conformational change on the enzyme derivative, which hinders AMP interaction with the protein. The results point to the importance of selecting suitable conditions for the study of the regulatory properties in allosteric enzymes.

Adenosine Monophosphate↗
PubMed1992

[Clinical study of 20 cases of bronchial carcinoid].

We present a retrospective study of twenty patients in whom bronchial carcinoids, and five, peripheric. One case met the criteria of atypical carcinoid. The mean age of presentation was 46.66 +/- 17.07 years (15-76), with predominance of the female gender (3:2). Twenty per cent of patients were asymptomatic and in the remainder, the diagnosis suffered an average delay of 19 months since the appearance of symptoms. Such symptoms were cough (50%), recurrent pneumonias (40%), fever (35%), hemoptysis (35%), thoracal pain (30%), carcinoid syndrome (10%) and consumptive syndrome (5%). The radiology showed lobular or segmentary atelectasis (40%), nodule/mass (30%), lobular or segmentary consolidation (20%), obstructive pneumonitis (5%) and atypical pleural effusion (5%). Direct endoscopic vision offered a sensitivity of 84.6%, while transbronchial biopsy, just 69.2%. Metastasis in mediastinal, suprarenal, thyroid and brain gangliar chains were detected.

Adolescent↗
PubMed1991

Confirmation method for the identification and determination of some organophosphorus and organochlorine pesticides in cocoa beans by gas chromatography-mass spectrometry.

The main objective of this work is to develop a routine quality control method for pesticide residues in cocoa beans, using gas chromatography-mass spectrometry. The investigated pesticides, which are used to control pests in the growing of cacao, are: Acephate, Propoxur, HCH, Heptachlor, Fenitrothion, Pirimiphos-methyl, Aldrin, Dieldrin, pp'-DDE, op-DDE and DDT. Two extraction methods were tested. The first was based on strong attack by concentrated sulphuric acid and later extraction with n-hexane: the investigated residues were Acephate, HCH, Fenitrothion and DDT; recoveries were 68-95% and the detection limits 0.5-10 ppb. The second extraction method was based on the Universal Trace Residue Extractor (UNITREX), which consists of a distillation system for organophosphorus and organochlorine pesticides in fatty samples. The investigated residues were Heptachlor, Pirimiphos-methyl, Aldrin, Propoxur, Dieldrin, op-DDE and pp'-DDE; recoveries were 67-88% and the detection limits 1-10 ppb.

Cacao↗
PubMed1991

Presence of an extracellular glycosyltransferase in human dental plaque.

1. Glycosyltransferase activity incorporating 14C-radioactivity from [14C]sucrose into endogenous acceptor was demonstrated in human dental plaque. 2. The enzyme was localized in dental plaque into two forms: (a) associated form to bacteria (pellet 10,000 g) and (b) released as an extracellular form (supernatant 10,000 g). 3. The reaction product was insoluble in 95% ethanol, soluble in trichloroacetic acid, and it was a mixture of saccharides with different sizes, as was demonstrated by column chromatography. 4. Exogenous activity with Dextran T-10 as substrate was also demonstrated, and it represented 9% of the total endogenous activity. 5. Characterization of the extracellular glycosyltransferase, and comparative results with glycosyltransferase secreted by oral bacteria in cultures medium are discussed.

Bacteria↗