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F Sousa

Publications and source records attributed to F Sousa.

13 recordsLinked to original sources
PubMed2006

Intensity- and muscle-specific fascicle behavior during human drop jumps.

The present study was designed to examine fascicle-tendon interaction in the synergistic medial gastrocnemius (MG) and soleus (Sol) muscles during drop jumps (DJ) performed from different drop heights (DH). Eight subjects performed unilateral DJ with maximal rebounds on a sledge apparatus from different DH. During the exercises, fascicle lengths (using ultrasonography) and electromyographic activities were recorded. The results showed that the fascicles of the MG and Sol muscles behaved differently during the contact phase, but the whole muscle-tendon unit and its tendinous tissue lengthened before shortening in both muscles. The Sol fascicles also lengthened before shortening during the ground contact in all conditions. During the braking phase, the Sol activation increased with increasing DH. However, the amplitude of Sol fascicle lengthening was not dependent on DH during the same phase. In the MG muscle, the fascicles primarily shortened during the braking phase in the lower DH condition. However, in the higher DH conditions, the MG fascicles either behaved isometrically or were lengthened during the braking phase. These results suggest that the fascicles of synergistic muscles (MG and Sol) can behave differently during DJ and that, with increasing DH, there may be specific length change patterns of the fascicles of MG but not of Sol.

Adult↗
PubMed2006

A new cuticle scale hydrolysing protease from Beauveria brongniartii.

From a screening for the production of new proteases specific for cuticle scales, Beauveria brongniartii was selected producing an alkaline Ca(++) dependent protease. The purified had a molecular weight of 27 kDa and a pI value of 8.0. Substrate specificities of model substrates (wool with partially removed cuticles treated with SDS) were analyzed by protein release, dissolved organic carbon (DOC) and nitrogen analysis. The C/N ratio of released material turned out to be a good parameter to determine the site of action of proteases on fibres. Compared to other enzymes, the fungal protease preferentially hydrolyzed cuticle scales and has thus a potential for anti-shrinking pre-treatment of wool fabrics.

Animals↗
PubMed2006

Isolation of a fusion protein containing the antigenic domain 1 of human cytomegalovirus glycoprotein B and its application in ELISA tests.

The glycoprotein B (gB) of human cytomegalovirus represents a dominant antigen for the humoral immune response. The immunodominant region on gB is the antigenic domain 1 (AD-1), a complex structure that requires a minimal continuous sequence of more than 75 amino acids for antibody binding. In this study, this domain was expressed in Escherichia coli as a fusion protein with beta-galactosidase but yielded insoluble protein aggregates as inclusion bodies. To recover the fusion protein, inclusion bodies were solubilized by two extractions with urea 8 M: and the fusion protein then isolated using gel filtration chromatography. After confirmation of fusion protein antigenicity by Western blotting, the purified product was used as the capturing antigen in an enzyme-linked immunosorbent assay (ELISA) to determine the presence of viral antibodies in serum samples of pregnant women. A cut-off point of approximately 0.2 absorbance units could discriminate the results of seropositive from seronegative pregnant women. The data indicates the potential usefulness of the fusion protein for the development of immunoassay for detection of the HCMV antibodies.

Enzyme-Linked Immunosorbent Assay↗
PubMed2005

Unimolecular and bimolecular calculations for HN2.

Using a recently reported double many-body expansion potential energy surface, quasi-classical, statistical mechanics, and quantum resonance calculations have been performed for the HN(2) system by focusing on the determination of bimolecular (N + NH and H + N(2)) and unimolecular (decomposition of HN(2)) rate constants as well as the relevant equilibrium constants.

Journal Article↗
PubMed2005

Improved recovery of a fusion protein containing the antigenic domain 1 of the human cytomegalovirus glycoprotein B.

Heterologous expression in Escherichia coli often leads to production of the expressed proteins as insoluble and inactive inclusion bodies. The general strategy for protein recovery includes isolation and washing of inclusion bodies, solubilization of aggregated protein and refolding of solubilized protein. The process of refolding, as well as the other steps involved in inclusion body recovery, must be optimized according to the characteristics of each protein. For the development of reliable and inexpensive serodiagnostic tests, the antigenic domain 1 (AD-1) of human cytomegalovirus glycoprotein B was expressed in E. coli and a process was developed to increase recovery of the fusion protein containing AD-1. A comparison of disruption methods and different conditions involved in recovery of this fusion protein from inclusion bodies is presented. The developed method gives a high yield of the fusion protein with a purity sufficient for use in diagnostic tests.

Antigens, Viral↗
PubMed1999

Single- versus dual-platform assays for human CD34+ cell enumeration.

We comparatively assessed CD34+ cell quantification by two of the recently available single platform assays, the IMAGN 2000 STELLer (Immucor, Lisbon, Portugal) microvolume fluorimetry and the ProCOUNT (BD-ENZIfarma, Lisbon, Portugal) flow cytometry, with our "in-house" dual-platform flow cytometric assay. The performance of the methods was evaluated by linearity and reproducibility tests. The linearity study, over a range of 0-1,200 CD34+ cell/microl, gave a good linear relationship for the three methods, with R(2) > 0.99. Precision tested at three different concentrations gave coefficients of variation ranging from 3.6-26.4% for the STELLertrade mark, 2.4-13.8% for the ProCOUNT, and 3.2-6.4% for flow cytometry. CD34+ cells were quantified in umbilical cord blood (UCB), UCB enriched-leukocyte buffy-coat (BC), mobilized peripheral blood (PB) and mobilized peripheral blood progenitor cells (PBPC) collected by leucapheresis, from a total of 72 samples. Flow cytometric results showed good linear correlation to the absolute counts obtained by the STELLer and ProCOUNT for all samples (R > 0.90 for all methods), with no differences when compared by paired tests (P > 0.05). Linear correlations between methods were also found when individually looking at the different cell sources: UCB or PB, BC, and PBPC, with low, intermediate and high CD34+ cell concentrations, respectively. Furthermore, with the exception of a significant difference between the ProCOUNT and STELLer results for UCB (P < 0.05), no other difference between methods was found for each of the individual populations (P > 0.05). To our knowledge, this is the first report in which the results are presented and analyzed according to each source of CD34+ cells. Our results show that the STELLer and the ProCOUNT are equally efficient for the dual-platform flow cytometric assay in CD34+ cell quantification.

Antigens, CD34↗
PubMed1996

[Echocardiographic evaluation of the aortic and pulmonary valve areas in the newborn infant. Normal patterns].

OBJECTIVES: To determine normal values of the aortic and pulmonary functional valve areas in healthy newborn children. MATERIAL AND METHODS: We prospectively studied 32 newborns (17 boys) who were included in the following criteria: healthy parents, normal pregnancy, eutocic delivery, Apgar index 10 at 5 minutes weight between 2.500 and 4.000 kg, normal physical and echocardiographical examinations. The echocardiographical examination was executed during the first 48 hours of life. We used the continuity equation to calculate the aortic and pulmonary functional valve areas. As a reference we used the anatomic (pi r2) aortic and pulmonary valve areas, calculated in the bidimensional images from the distance measured between the two insertion points of the sigmoid valves. RESULTS: We had echocardiographic images and Doppler registrations of excellent quality, in all the newborn children. The functional pulmonary valve area ranged between 0.30 and 0.50 cm2 (mean +/- SD = 0.41 +/- 0.06) and the anatomical one ranged between 0.29 and 0.49 cm2 (mean +/- SD = 0.49 +/- 0.05), without statistical significance and with a correlation index 0.92. The functional aortic valve area ranged between 0.20 and 0.40 cm2 (mean +/- SD = 0.31 +/- 0.05) and the anatomical ranged between 0.21 and 0.36 cm2 (mean +/- SD = 0.29 +/- 0.05), without statistical significance and with a correlation index 0.91. CONCLUSION: There is a good correlation between the functional aortic and pulmonary valve areas, calculated from the continuity equation, and the anatomical ones. These values will be useful in characterizing the critical stenosis of the newborn child with decreased ventricular function, where the transvalvular gradient is inaccurate in the quantification of the obstruction.

Aortic Valve↗