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Biomedical subjects

R Valls

Publications and source records attributed to R Valls.

At least 19 recordsLinked to original sources
PubMed2001

(S)-12-hydroxygeranylgeraniol-derived diterpenes from the brown alga Bifurcaria bifurcata.

Four novel diterpenes were isolated from the brown alga Bifurcaria bifurcata collected off the Atlantic coast from Morocco, and their structures established by spectral and chemical methods. These compounds are acyclic diterpenes derived from (S)-12-hydroxygeranylgeraniol. One of them is its dehydration product at C-12, while the others are its oxidation derivatives: the methyl ester of the acid at C-1 and two stereoisomers (Z and E) of the aldehyde at C-1. These results are discussed from a chemotaxonomic point of view.

Diterpenes↗
PubMed1999

An inductively coupled plasma method for determination of cyclophosphamide loaded to polymeric systems.

A new method for the determination of cyclophosphamide content of polyalkylcyanoacrylate nanoparticles was developed. The analyses were carried out by inductively coupled plasma atomic emission spectrometry (ICP-AES) by measuring the phosphorus content in the drug. The results obtained by this non-selective technique were compared with those given by high performance liquid chromatography (HPLC) a selective procedure that permits the detection of the cyclophosphamide molecule, and its degradation products. Sensitivity and reproducibility of both procedures were also determined. The ICP-AES method was demonstrated to be valid for sensitivity, precision, accuracy and specificity. In spite of ICP method is not a suitable procedure to analyze the degradation products of cyclophosphamide, the sensitivity of ICP is higher than chromatographic technique. Nevertheless, both procedures are appropriate for the determination of cyclophosphamide-loaded nanoparticles.

Antineoplastic Agents, Alkylating↗
PubMed1998

[Studies on HIV patients].

This article analyzes the data obtained from a series of planned studies run over a two year period of time by a group of nurses while they carried out a health education program with HIV positive patients. This was made possible by a grant from FIS, Health Research and Investigation Fund. Due to the collaboration by professionals in the Nursing School of the University of Barcelona and the Bellvitge Hospital, these studies could be under-taken.

HIV Infections↗
PubMed1997

Diagnostic imaging of tibial periosteal ganglion.

A case of a soft tissue tumor situated in the anterior surface of the proximal end of the tibia in an adult patient is demonstrated by conventional radiographs, CT, and MRI. The lesion was well defined with respect to the adjacent soft tissue. The CT exam showed a soft tissue mass with external cortical erosion and thick spicules by periosteal reaction. On T1-weighted images the mass was homogeneous and of low signal intensity, whereas on T2-weighted images it showed a high signal intensity, with some septa in the mass. The differential considerations include a periosteal chondroma, a lipoma, a subperiosteal hematoma, an inflammatory process, a giant cell tumor of tendon sheath, and a parosteal osteosarcoma. The CT and MR features of these entities are reviewed as an aid in differential diagnosis of the periosteal ganglion.

Adult↗
PubMed1996

Elastofibroma dorsi: a chest wall pseudotumor. Computed tomography and magnetic resonance imaging diagnosis.

"Elastofibroma dorsi" is a benign soft tissue mass usually arising between the chest wall and the inferior and medial aspects of the scapula. This lesion is not a true neoplasm but rather a reactive hyperplasia of elastic fibers. We present a case report of a woman with a subscapular mass, which was studied by computed tomography and magnetic resonance imaging. These are the methods of choice to study a soft tissue mass in order to define the inner structures and limits Computed tomography is helpful to guide a percutaneous biopsy, avoiding lesions to adjacent structures. Biopsy is recommended even when the imaging presentation seems typical of elastofibroma. The pathologic findings are diagnostic. No treatment is necessary in the asymptomatic patient. The treatment of choice for a symptomatic elastofibroma is local excison. There have been no reported cases of malignant transformation.

Female↗
PubMed1995

(S)-13-hydroxygeranylgeraniol-derived furanoditerpenes from Bifurcaria bifurcata.

Two new diterpenes were isolated from a sample of the brown alga Bifurcaria bifurcata collected from Brittany on the Atlantic coast and their structures established by spectroscopic methods. The new diterpenes are derived from (S)-13-hydroxygeranylgeraniol by terminal cyclization and oxidation leading to a furan-3-yl ring or a beta,gamma-epoxy-gamma-lactone. One of them showed a cytotoxic effect to fertilized sea urchin eggs. The chemical shifts of the methyl groups and quaternary carbons in (S)-13-hydroxygeranylgeraniol have been revised to take account of the results obtained in a 2D NMR long-range C-H correlation experiment and the absolute configuration at C-13 determined for the first time. The geographical variation in the diterpenoid composition of B. bifurcata was also studied.

Animals↗
PubMed1993

Venographic assessment of deep vein thrombosis and risk of developing post-thrombotic syndrome: a prospective study.

It is well known that patients with deep vein thrombosis (DVT) constitute a risk group for development of pulmonary embolism. However, the relation of DVT and the extent thereof with the subsequent sequelae (post-thrombotic syndrome) are insufficiently investigated. We have prospectively studied a series of consecutive patients admitted because of DVT on lower limbs, trying to correlate venographic findings during acute DVT with post-thrombotic (PTS) symptoms that develop later. Seventy-nine patients (84 limbs) with acute DVT were followed-up in our out-patient clinic at 4-monthly intervals for 3 years. At each visit patients were carefully examined regarding the appearance of PTS symptoms and/or signs from the DVT-affected leg. Three years after discharge, presence of PTS signs was assessed according to a simple scoring system. And then correlated to venographic findings during acute DVT. Patients were classified as having no (37 legs), mild (30 legs), or severe PTS signs (17 legs). Patients with popliteal vein involvement showed a significantly higher incidence of PTS 3 years later (P < 0.001). The risk of PTS also increased as DVT extent increased (P < 0.001). Nevertheless, the logistic regression analysis showed that DVT location explained all the differences (P < 0.001). In other words, DVT extent was overriden by the significance of DVT location, being popliteal the only location that showed a relevant contribution to the PTS incidence (95% confidence interval = 2.49-71.5).

Acute Disease↗
PubMed1991

Upper-extremity deep venous thrombosis and pulmonary embolism. A prospective study.

We prospectively evaluated the prevalence of pulmonary embolism (PE) in 30 consecutive patients with proved deep venous thrombosis (DVT) of the upper extremity. Ten patients (seven male and three female; mean age, 43 years) had primary DVT, and 20 patients (14 male and six female; mean age, 52 years) had catheter-related DVT. Ventilation-perfusion lung scans were routinely performed at the time of hospital admission to all but one patient (one patient was critically ill, and he died four days after DVT diagnosis because of massive PE). Lung scan findings were normal in nine of ten patients with primary DVT, and they were indetermine in the remaining patient. By contrast, perfusion defects were considered highly suggestive of PE in four patients with catheter-related DVT; two patients had indeterminate lung scans, and 13 patients had normal scans. We conclude that PE is not a rare complication in upper extremity DVT, and that patients with catheter-related DVT seem to be at a higher risk.

Adult↗