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Biomedical subjects

R Prats

Publications and source records attributed to R Prats.

8 recordsLinked to original sources

High prevalence of Mycobacterium tuberculosis DNA in biopsies from sarcoidosis patients from Catalonia, Spain.

BACKGROUND: Sarcoidosis is a systemic granulomatous disease of unknown etiology. The presence of mycobacterial nucleic acid components in patients with sarcoidosis has been demonstrated with varying degrees of success. OBJECTIVES: The aim of this study was to estimate the presence of Mycobacterium tuberculosis DNA in tissues from sarcoidosis patients, in Catalonia, Spain, as well as to assess the long-term clinical course in these patients. METHODS: Fifty-eight paraffin-embedded tissue biopsies corresponding to cases of sarcoidosis (n = 23), lung neoplasm (n = 23), and lung tuberculosis (n = 12) available in 1996 were analyzed in a retrospective study by means of a nested polymerase chain reaction using primers corresponding to the insertion element IS6110 of M. tuberculosis complex. For greater sensitivity, Southern blot hybridization was performed. Clinical data were recorded prior to and after PCR analysis (follow-up reported until 2002). RESULTS: M. tuberculosis DNA was present in 9 out of 23 sarcoidosis biopsies (39%), in 1 out of 23 control patients (4%) (p < 0.01), and in all tissue samples from the 12 control patients with tuberculosis. To date, none of these sarcoidosis patients has developed tuberculosis over a mean (+/-SD) follow-up period of 11 (+/-3.4) years. CONCLUSION: In our setting, M. tuberculosis DNA is present in tissue biopsies of significantly more sarcoidosis patients than controls. However, these results do not demonstrate causality, although they may suggest a link between M. tuberculosis infection and sarcoidosis in some cases. Follow-up of these patients suggests that M. tuberculosis-DNA-positive sarcoidosis patients are not at greater risk of developing tuberculosis than M. tuberculosis-DNA-negative patients.

Adult↗

Appearance of methicillin-resistant Staphylococcus aureus (MRSA) sensitive to gentamicin in a hospital with a previous endemic distinct MRSA.

Since 1990 a clone of gentamicin and methicillin-resistant Staphylococcus aureus (MRSA) has remained endemic in our hospital, but since January 1996 a gentamicin-sensitive strain has progressively replaced the previous clone. We characterized the phenotypic and molecular pattern of the MRSA strains isolated in our hospital in 1996 and compared prospectively the epidemiological, clinical and evolutionary characteristics of ninety patients infected or colonized by gentamicin-sensitive MRSA (GS-MRSA) (49) and by gentamicin-resistant MRSA (GR-MRSA) (41). Finally we studied the variation of aminoglycoside consumption in our hospital from 1989 to 1996. We observed two antibiotypes (GS-MRSA and GR-MRSA) corresponding to two major chromosomal patterns. Patients with GS-MRSA usually acquired the infection 72 hours after hospital admission. No significant differences were observed in epidemiological characteristics, clinical presentation and evolution between patients with GS-MRSA and GR-MRSA. Since 1989 aminoglycoside intake in our hospital has decreased by 46%.

Adolescent↗

[Chronic pancreatitis. A recent national experience with its surgical management].

BACKGROUND: The prevalence of chronic pancreatitis in Chile is not known and there is no local information about the surgical treatment of this disease. AIM: To review retrospectively the results of surgical treatment of chronic pancreatitis. MATERIAL AND METHODS: The charts of 17 patients (12 male), aged 7 to 65 years old, with chronic pancreatitis that were operated in three different Chilean regions, were reviewed. RESULTS: Seven patients had previous endoscopic therapeutic procedures (papillotomy in 4 and stent placing in 3). Seven patients had been subjected to previous biliary surgical procedures. Indications for surgery were severe pain in 14 patients, the suspicion of a pancreatic carcinoma in 4 patients, an infected pseudocyst in one and massive bleeding of multiple pseudo-aneurysms in a pseudocyst in one patient. Twelve patients were subjected to decompressions and 5 to pancreatic resections. There was no operative mortality and one transient pancreatic fistula. After an average follow up of 22 months, pain improved in 94% of cases, pancreatic cancer was diagnosed in one patient and 79% of subjects gained weight. One patient became insulin dependent, one increased his insulin requirements and one had transient steatorrhea, since she could not afford pancreatic enzyme replacement therapy. CONCLUSIONS: The multidisciplinary approach of patients with chronic pancreatitis, with selective use of surgery, may greatly improve their quality of life.

Adolescent↗

[Evolution of pregnancy in adolescents of Catalonia (1987-1992)].

OBJECTIVE: To analyse the evolution of both pregnancies and voluntary terminations among adolescent women living in Catalonia. DESIGN: An observational crossover study. SETTING: Catalonia. PATIENTS AND OTHER PARTICIPANTS: The rates of fertility, pregnancy and voluntary termination (VT) were calculated. The ratio of VT per 100 live births among adolescent women (aged 15 to 19) and among the general population (15 to 49) between 1987 and 1992 was also calculated. MEASUREMENTS AND MAIN RESULTS: The pregnancy rate of adolescents remained stable throughout the study period, whereas their fertility rate went down. In parallel there was a spectacular increase in the percentage of VTs per live birth among adolescents. CONCLUSIONS: Since the pregnancy rate among adolescents remained practically stable throughout the study period, an increase in activities aimed at primary prevention of these pregnancies is recommended.

Abortion, Induced↗

Normal growth and division of Escherichia coli with a reduced amount of murein.

The classical model of a murein monolayer for the structure of the murein sacculus of Escherichia coli is at present a controversial matter due to recent advances in the microscopic and biochemical knowledge of this cellular component (B. Glauner, J.-V. Höltje, and U. Schwarz, J. Biol. Chem. 263:10088-10095, 1988; M. Leduc, C. Frehel, E. Siegel, and J. van Heijenoort, manuscript in preparation). We have studied how the limitation in the supply of the murein-specific precursor meso-diaminopimelic acid (DAP) would affect cell growth and morphology as well as murein structure and content per unit of surface area in E. coli strains auxotrophic for DAP. Our observations indicated that the amount of murein per unit of cell surface area could be reduced by about 50% when the external concentration of DAP was equal to or lower than 0.5 microgram/ml. Cells with a reduced amount of murein did not show any detectable alteration in their morphology and characteristics of growth. Furthermore, no major alterations in murein structure were observed by high-pressure liquid chromatography analysis. However, the modification of murein that normally takes place at the initiation of the stationary phase was partially prevented. These results favor the alternative hypothesis of a thin, multilayered structure for the sacculus of E. coli rather than the monolayer model.

Bacteriolysis↗

A new beta-lactam-binding protein derived from penicillin-binding protein 3 of Escherichia coli.

In this paper we describe a new beta-lactam-binding protein from the cell envelope of Escherichia coli. It can be detected in cells grown at either 37 or 42 degrees C in medium containing glucose but not in cells grown at 30 degrees C. This novel component has an apparent molecular size that is 2.0 kilodaltons larger than that of penicillin-binding protein 3 and is derived from the latter through a divalent-cation-mediated process probably catalyzed by components located in the periplasmic space. The significance of this protein with regard to regulation of the amount of functional penicillin-binding protein 3 in the cell is discussed.

Acyltransferases↗

Activity of penicillin-binding protein 3 from Escherichia coli.

The activity of penicillin-binding protein 3 of Escherichia coli has been studied both in vivo and in ether-permeabilized cells. The peptidoglycan transpeptidase activity of penicillin-binding protein 3 appears to use either nascent or exogenously added UDP-N-acetylmuramyl tripeptide-derived substrates as acceptors. By means of a defilamentation system which elicited the activity of penicillin-binding protein 3 in vivo, the structure of peptidoglycan made by this enzyme has been elucidated. This peptidoglycan, very probably of septal location, contained increased amounts of cross-linked peptidoglycan as well as a higher ratio of tripeptide-containing cross-linked subunits.

Acyltransferases↗