Biomedical subjects
J Navas
Publications and source records attributed to J Navas.
Nucleotide sequence and intracellular location of the product of the fosfomycin resistance gene from transposon Tn2921.
An 863-base-pair DNA fragment containing the fosfomycin resistance gene from transposon Tn2921 was sequenced. Analysis of the sequence revealed the presence of a single open reading frame that encoded the FOS polypeptide of 16 kilodaltons from Tn2921. Minicell fractionation studies showed that the FOS protein was located in the bacterial cytoplasm.
[Treatment of skin ulcer using oil of mosqueta rose].
Oil rose of mosqueta (Rosa aff. Rubiginosa L.) is a concentrated solution in linoleic (41%) and linolenic acid (39%), that offers benefit therapeutic effects in the wound healing. Ten patients affected of leg ulcers and post-surgical wounds were treated by 26% oil concentrated rose of mosqueta with very notable improvement on its healing compared with the control group. Due to the lack of side effects, we believe rose of mosqueta oil is very usefull to these conditions. Mechanism of actions and others indications are discussed.
Hyperuricemia, gout, and autosomal dominant polycystic kidney disease.
The relationship between hyperuricemia, gout, and autosomal dominant polycystic kidney disease (ADPKD) is not widely recognized. In an attempt to further clarify this relationship, the authors have studied 17 patients with ADPKD, 9 controls, 9 patients with proven gout and chronic renal failure, 11 patients with gout and normal renal function, and 11 patients with chronic renal failure. The mean serum uric acid concentration was higher in patients with ADPKD as a group than in controls (8.0 +/- 1.7 mg/dl vs. 6.4 +/- 1.6 mg/dl, p less than .02). Clinical gout was identified in 24% of patients with ADPKD; none of the patients with chronic renal failure of other etiologies had gout. Fractional excretion of uric acid and the activity of the enzyme hypoxanthine guanine phosphoribosyl transferase (HGPRT) were not different among the groups studied. From this study the authors conclude that ADPKD should be included among those diseases associated with hyperuricemia and gout. A partial deficiency in HGPRT or abnormal renal handling of uric acid do not appear to be responsible for the increased incidence of gout in patients with ADPKD.
Hypersensitivity to ketoconazole preparations: study of 4 cases.
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[A 31-year-old woman with episodes of headache and dyspnea].
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Liver sinusoidal dilatation in familial Mediterranean fever.
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Fosfomycin causes transient lysis in Escherichia coli strains carrying fosfomycin-resistance plasmids.
Escherichia coli cells carrying fosfomycin-resistance plasmids show high levels of resistance towards this drug. However, the plasmid-carrying strains exhibited a transient lytic phase induced by fosfomycin when grown in rich liquid media. This lytic phase was not observed if the cells were grown in liquid minimal media. Fosfomycin-induced lysis depended on the accumulation of drug inside the bacteria, presumably as a result of the saturation of the fosfomycin modification system. Growth recovery after lysis was not due to drug inactivation in the culture medium and could be explained by selection of mutants showing impaired fosfomycin transport when high concentrations of fosfomycin were used. However, there was no selection of mutants with low drug concentrations.
Fosfomycin-resistance plasmids determine an intracellular modification of fosfomycin.
Escherichia coli cells carrying fosfomycin-resistance plasmids modify fosfomycin intracellularly. The product of this modification (fosfomycin-derivative) differs from fosfomycin in chromatographic mobility, but the chemical nature of the modification is not yet known. Fosfomycin-derivative appears to have a cytoplasmic location and lacks antibiotic activity. The modification system can be saturated by an excess of fosfomycin in the incubation media.
Structural and functional analyses of the fosfomycin resistance transposon Tn2921.
The fosfomycin resistance transposon Tn2921 is flanked by directly repeated sequences homologous to the Tn10-related insertion sequence IS10. The nonrepeated DNA sequences of Tn2921 can be deleted without affecting the transposition ability of the element, showing that at least one of the direct repeats is an active insertion sequence. Transposition of Tn2921 seems to occur through direct transposition, since cointegrates have not been observed. The evolutionary relatedness of Tn2921 and IS10 is discussed.
Cloning and expression in minicells of the determinant of resistance to fosfomycin from the transposon Tn2921.
The fosfomycin resistance determinant of the transposon Tn2921 has been localized and cloned into the plasmid pBR322. A DNA fragment of 1 kb contains all the information required for full expression of the resistance. The level of resistance was unaffected by the plasmid copy number and by the orientation in which the fragment was cloned. Studies in minicells showed that this 1-kb fragment directed the synthesis of a single polypeptide with a molecular mass of 16 kDa.
Toxic epidemic syndrome: musculoskeletal manifestations.
The musculoskeletal manifestations of a new systemic disease that developed after toxic oil consumption are described. Clinically, it was characterized by the presence of arthralgias, sometimes arthritis, extensive muscle atrophy, severe neuropathy and a scleroderma-like skin involvement. Radiologically, different types of osteopenia could be seen in the absence of joint space narrowing or erosions. Neither hypertrophy, nor hyperplasia of synoviocytes were seen on microscopic examination. A non-necrotizing vasculitis and increase in fibrous tissue were observed at different levels.
[Nephrotic syndrome and renal artery stenosis].
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Genetics of the replication and maintenance functions of the hemolytic plasmid pSU316. Cloning of an IncFIII determinant.
Two miniplasmids have been constructed from pSU306, a Tn802 insertion derivative of the IncFIII-IncFIV hemolytic plasmid pSU316. One of these, pSU3027, is a low copy number plasmid expressing both IncFIII and IncFIV incompatibilities, but is rather unstable, and probably lacks a putative par gene. The other, pSU3025, is maintained in about 340 copies per genome equivalent and expresses only IncFIII incompatibility. Most of the PstI-generated fragments from pSU3027 have been cloned in pBR322. One of the resulting plasmids, pSU3135, contains an insertion of 0.5 kb in the vector molecule, and expresses IncFIII, but not the IncFIV incompatibility. These results allowed us to identify and locate several genes involved in the control of pSU316 replication and stable plasmid maintenance.
Incompatibility properties of the IncFIII/FIV haemolytic plasmid pSU316 when integrated in the Escherichia coli chromosome.
The haemolytic plasmid pSU316 is incompatible with members of the IncFIII and IncFIV incompatibility groups. Plasmid pSU307 (pSU316 hlyC::Tn5) was inserted by integrative suppression into the chromosome of JW112, a temperature-sensitive dnaA mutant of Escherichia coli. The incompatibility properties of this strain (SU51) were studied and it was found that: (1) plasmid pSU306 (pSU316 hlyA::Tn802) was rapidly lost from strain SU51 both at 30 degrees C and 42 degrees C; (2) the IncFIII plasmid pSU397 (ColB-K98::Tn802) was lost from strain SU51 and at 42 degrees C but not at 30 degrees C; and (3) the IncFIV plasmid R124 was stably maintained in strain SU51 at both temperatures. Revertants of pSU307 to the autonomous state could be obtained from SU51. These revertants exerted incompatibility towards the prototype plasmids pSU306, pSU397 and R124 in the same way as pSU307 itself. Thus, strain SU51 provided a suitable method for distinguishing the three different incompatibility determinants of plasmid pSU316.
The value of ultrasonic scanning in the differentiation of acute post-transplant renal failure.
In 43 renal transplant patients studied by ultrasonography there were 32 episodes of acute rejection and 17 of acute tubular necrosis. The size of the kidney increased in all cases. However, in 75 per cent of the patients with acute rejection the central echoes of the renal sinus increased conspicuously, while in 77 per cent of those with acute tubular necrosis the echogenicity of the central sinusal complex decreased. These findings may be expressions of different pathological lesions at the renal sinus level in patients with acute rejection and acute tubular necrosis, which would modify the acoustic interphase. Therefore, we have found panniculitis, vasculitis, thrombosis and inflammatory cellular infiltration of the urinary collecting systems to be significant in patients with acute rejection but not in those with acute tubular necrosis. Ultrasonography can be an adjuvant instrument for the sometimes difficult differential diagnosis between acute tubular necrosis and acute rejection immediately after transplantation, and also for the diagnosis of acute rejection whenever it appears.
Conn's syndrome in a patient with acromegaly.
The renin-angiotensin-aldosterone system (RAAS) in a female patient suffering from acromegaly and severe hypertension was studied and a suppressed plasma renin activity could be found. A catheterisation of both adrenal veins, a bilateral adrenal gammagraphy and an abdominal CT scan confirmed the diagnosis of an aldosterone-producing right adrenal adenoma (Conn's Syndrome). We greatly emphasized the need of investigating the RAAS in acromegalic patients suffering from hypertension.
[Immunochemistry of Bothrops venoms. II. Comparative analysis of the common antigenic components of 6 species of Bothrops venoms].
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