Vasoactive effects of basic and acidic fibroblast growth factors in hamster cheek pouch arterioles

Fibroblasts growth factors (FGFs) exhibit well-known angiogenic actions, but there is some controversy about whether they have vasoactive effects on blood vessels which might contribute to angiogenesis per se. To clarify this, changes in arteriolar diameter were recorded during observation by videomicroscopy of 3rd- and 4th (terminal)-order arterioles (resting diameters 22.5 +/- 0.5 microns and 14.4 +/- 0.3 microns, respectively) in the hamster cheek pouch in response to FGF application. Recombinant human bFGF (basic) and aFGF (acidic) were applied from micropipettes positioned 5-10 microns from the adventitial surface of vessels. Maximum vasodilator effects of adenosine (10(-4) M) applied in a similar way were also observed. Adenosine increased the diameters of 4th-order arterioles by 37.2 +/- 3.8% and those of 3rd-order arterioles by 38.7 +/- 2.7. bFGF produced vasodilatation (threshold dose 0.1 ng ml-1) in both classes of arterioles, while aFGF produced dose-dependent constriction (threshold dose 0.01 ng ml-1). A maximal dilator effect in 4th-order arterioles was obtained with 100 ng ml-1 bFGF, when diameters reached 82.6 +/- 2.4% of those with adenosine. Maximal constrictor effect (-48.2 +/- 5.6% of resting diameter) occurred with a dose of 100 ng ml-1 aFGF. Vehicle alone (MOPS or bicarbonate buffer used as solvents for FGFs) had no effect. As vasoconstrictors are known to stimulate growth of smooth muscle cells while dilators stimulate growth of endothelial cells, it is possible that the opposing vasoactivities demonstrated for aFGF and bFGF are linked with their selective mitogenicity for smooth muscle and endothelial cells, respectively, and contribute to their angiogenic actions.     

In vitro assessment of the biological activity of basic fibroblast growth factor released from various polymers and biomatrices

The kinetics of controlled release of basic fibroblast growth factor (bFGF) from polymers (sutures, polycarbonate, Hydron, and Elvax), biopolymers (alginate), and biomatrices (lens capsules), and conditions for storage of bFGF (temperature, plastic type, heparin) were evaluated in vitro. Tissue culture proliferation bioassays with 3T3 fibroblasts, showed that only lens capsules with bFGF had a sustained release of bFGF for up to three weeks. The other materials released all of the 'bound' bFGF with two hours or produced an inflammatory response in vivo. Therefore, the lens tissue had the most potential for controlled long-term delivery of bFGF in vivo. These studies emphasise the importance of in vitro analysis of release kinetics of growth factors from a range of materials as a basis for potential in vivo applications.     

A Proposal for Error Handling in OpenMP

OpenMP has been focused in performance applied to numerical applications, but when we try to move this focus to other kind of applications, like Web servers, we detect one important lack. In these applications, performance is important, but reliability is even more important, and OpenMP does not have any recovery mechanism. In this paper we present a novel proposal to address this lack. In order to add error handling to OpenMP we propose some extensions to the current OpenMP specification. A directive and a clause are proposed, defining a scope for the error handling (where the error can occur) and specifying a behaviour for handling the specific errors. Some examples of use are presented, and we present also an evaluation showing the impact of this proposal in OpenMP applications. We show that this impact is low enough to consider the proposal worthwhile for OpenMP.     

Cooperation. Relationship between district and referred medical center services

Theoretic basis of cooperation relationship between organizations are reviewed. Second one, these theoretic concepts are applied to the relationship between district and reference medical Centers and Services, focusing on main problems of that relationship. The relevant role of communication and its new technologies are also discussed.     

Neural feature abstraction from judgments of similarity

The common neural network modeling practice of representing the elements of a task domain in terms of a set of features lacks justification if the features are derived through some form of ad hoc preabstraction. By examining a featural similarity model related to established multidimensional scaling techniques, a neural network is developed that generates features from similarity data and attaches weights to these features. The network performs a constrained search of a continuous solution space to determine the features and uses a previously developed regularization technique to minimize the number of features it derives. The network is demonstrated on artificial data, from which it recovers known features and weights, and on two real data sets involving the similarity of a set of geometric shapes and the abstract conceptual similarities of the 10 Arabic numerals. On the basis of these results, the relationship between the multidimensional scaling approach adopted by the network and an alternative additive clustering approach to feature extraction is discussed.     

Prognostic factors and etiology in patients with severe community-acquired pneumonia admitted at the ICU. Spanish multicenter study. Study Group on Severe Community-Acquired Pneumonia in Spain

OBJECTIVE: To determine the techniques used for the etiological diagnosis of community-acquired pneumonia in patients admitted to the intensive care unit (ICU) and to describe the predominant causative organisms as well as prognostic factors of ICU mortality. PATIENTS AND METHODS: A total of 262 patients with community-acquired pneumonia admitted to 26 ICUs between 1 November of 1991 and 31 October of 1992 were included in a prospective, open, multicenter study. RESULTS: The diagnostic techniques most frequently used were blood culture (243 cases) and simple tracheal aspirate (166 cases). Simple tracheal aspirate (58.4%), bronchoalveolar lavage (47.7%), and protected-specimen brush (44.2%) were the techniques that showed the highest diagnostic reliability. In 220 cases, techniques considered of high diagnostic probability were employed. With the use of these procedures, the most frequent causative pathogens were Streptococcus pneumoniae (13.6%) and Legionella pneumophila (9.5%). In 100 cases (45.5%), no pathogen was isolated. A total of 88 patients (33.6%) died during the ICU stay. Predictive variables of poor outcome selected by means of a multivariate analysis were as follows: multisystemic failure (OR = 28.6; 95% CI: 12.8-65.1; p = 0.0001), APACHE II at the time of ICU admission (OR = 5.3; 95% CI: 2.5-11.3; p = 0.0001), progression and/or spread of lung infection (OR = 4.5; 95% CI: 2.4-8.4; p = 0.0001), and shock on admission (OR = 8.48; 95% CI: 4.5-15.9; p = 0.0001). CONCLUSIONS: In 45.5% of patients with community-acquired pneumonia admitted to ICU, no causative pathogen was identified. The prognosis of these patients was influenced by the severity of disease assessed by APACHE II score and presence of multisystemic failure and shock at the time of ICU admission.