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Biomedical subjects

J Mas

Publications and source records attributed to J Mas.

At least 55 records · Page 3Linked to original sources
PubMed1989

[Prevalence of antibodies against Toxoplasma gondii, rubella virus, cytomegalovirus and herpes simplex virus in pregnant women of Catalonia].

A seroepidemiological survey was carried out to evaluate the prevalence of antibodies against toxoplasma, rubella virus, cytomegalovirus (CMV) and herpes simplex virus in pregnant women from Catalonia during 1985. The study was carried out in a representative sample of the pregnant women cared for in public and private hospitals from Catalonia, which was selected in maternal clinics by random sampling. Antibody measurements were carried out with the following techniques: toxoplasma, IFI (positive values greater than or equal to 1:10); rubella virus, Iha (greater than or equal to 1:10); CMV and herpes simplex virus, CF (greater than or equal to 1:10). 50.21% of pregnant women had antibodies against toxoplasma, 97.48% against rubella virus, 73.31% against CMV, and 80.93% against herpes simplex virus. The presence of antibodies against CMV and herpes simplex virus were significantly associated ( less than 0.00001). The demographic and socioeconomic variables associated with the prevalence of antibodies were analyzed, and they were compared with other results from the literature.

Animals↗
PubMed1989

[Serum beta 2-microglobulin and ankylosing spondylitis].

The serum beta-2-microglobulin (B2-m) was evaluated by radio-immunoassay in 28 patients with ankylosing spondylarthritis. The mean B2-m level is within normal limits. There is no overall correlation with other biological or immunological parameters (Sed Rate, IgA, CD3+, CD4+, CD8+, Leu 7, NK activity). There is no difference between treated and untreated patients, between patients with recent or old disease. On the contrary, the mean the mean B2-m level is significantly lower in patients B27 positive, as compared with B27 negative. The possible role of anti-B2-m antibodies interfering with the serum B2-m assay discussed.

Adult↗
PubMed1988

Narcotic alkylating agents: synthesis, structure and biological activities.

The synthesis, structure and biological activities of a series of derivatives of normorphine, noracetylmethadol (IV a), 6-amino-4,4-diphenyl-3-heptanol acetate (V a), and norpropoxyphene (VI a), in which the corresponding nitrogen supports an alkylating group (chloroethyl or fumaroyl) are reported. Structural identification was achieved spectroscopically. 13C Nuclear Magnetic Resonance proved the most useful tool in this task. N-Chloroethylnoracetylmethadol (IV c), acted as a potent long-lasting analgesic. Although some compounds (IV c), (V c) and (V d) showed substantial cytostatic activity, no antineoplastic activity in mice with P388 leukaemia was detected in the series.

Alkylating Agents↗
PubMed1988

A fully automated contour detection algorithm the preliminary step for scatter and attenuation compensation in SPECT.

Contour detection is an important step in information extraction from nuclear medicine images. In order to perform accurate quantitative studies in single photon emission computed tomography (SPECT) a new procedure is described which can rapidly derive the best fit contour of an attenuated medium. Some authors evaluate the influence of the detected contour on the reconstructed images with various attenuation correction techniques. Most of the methods are strongly affected by inaccurately detected contours. This approach uses the Compton window to redetermine the convex contour: it seems to be simpler and more practical in clinical SPECT studies. The main advantages of this procedure are the high speed of computation, the accuracy of the contour found and the programme's automation. Results obtained using computer simulated and real phantoms or clinical studies demonstrate the reliability of the present algorithm.

Algorithms↗
PubMed1988

[Denny-Brown sensory neuropathy disclosing a bilateral ovarian adenocarcinoma].

The authors report the case of a 76 year-old woman examined because of occurrence of a paraneoplastic sensory neuropathy. Three months later, she developed a left inguinal adenopathy, metastasis of a bilateral ovarian adenocarcinoma. This case of particular interest in view of the way the neoplasm was discovered. The sensory neuropathy was previously reported to be associated with an ovarian cancer in only one case of the literature. Besides the tumor masse only limited to a left inguinal adenopathy, in this case emphasizes the ability of these rare metastasis. The ovarian cancer-associated antigen CA 125 is particularly useful for the diagnosis when high levels are found. In the absence of a pelvic tumor masse, the paraneoplastic sensory neuropathy, as well as the high levels of CA 125, have resulted in an exploratory laparotomy with extemporaneous examination of the ovaries, enabling to make the diagnosis of bilateral ovarian adenocarcinoma.

Adenocarcinoma↗
PubMed1986

Diagnosis of splenosis: the advantages of splenic scintiscanning with Tc 99m heat-damaged red blood cells.

We present one case of peritoneal splenosis, which was not confirmed by the splenic scintiscan with 99mTc-sulphur colloid, but whose diagnosis, carried out during a second scintiscan with 99mTc-heat-damaged RBC, was confirmed by laparotomy and histology. This case confirms that, for the diagnosis of splenosis, heat-damaged RBC scintigraphy must be used rather than either sulphur colloid scintigraphy or computed-tomography.

Choristoma↗
PubMed1986

Predatory prokaryotes: predation and primary consumption evolved in bacteria.

Two kinds of predatory bacteria have been observed and characterized by light and electron microscopy in samples from freshwater sulfurous lakes in northeastern Spain. The first bacterium, named Vampirococcus, is Gram-negative and ovoidal (0.6 micrometer wide). An anaerobic epibiont, it adheres to the surface of phototrophic bacteria (Chromatium spp.) by specific attachment structures and, as it grows and divides by fission, destroys its prey. An important in situ predatory role can be inferred for Vampirococcus from direct counts in natural samples. The second bacterium, named Daptobacter, is a Gram-negative, facultatively anaerobic straight rod (0.5 x 1.5 micrometers) with a single polar flagellum, which collides, penetrates, and grows inside the cytoplasm of its prey (several genera of Chromatiaceae). Considering also the well-known case of Bdellovibrio, a Gram-negative, aerobic curved rod that penetrates and divides in the periplasmic space of many chemotrophic Gram-negative bacteria, there are three types of predatory prokaryotes presently known (epibiotic, cytoplasmic, and periplasmic). Thus, we conclude that antagonistic relationships such as primary consumption, predation, and scavenging had already evolved in microbial ecosystems prior to the appearance of eukaryotes. Furthermore, because they represent methods by which prokaryotes can penetrate other prokaryotes in the absence of phagocytosis, these associations can be considered preadaptation for the origin of intracellular organelles.

Bdellovibrio↗
PubMed1985

Mathematical model for determining the effects of intracytoplasmic inclusions on volume and density of microorganisms.

Procaryotic microorganisms accumulate several polymers in the form of intracellular inclusions as a strategy to increase survival in a changing environment. Such inclusions avoid osmotic pressure increases by tightly packaging certain macromolecules into the inclusion. In the present paper, a model describing changes in volume and density of the microbial cell as a function of the weight of the macromolecule forming the inclusion is derived from simple theoretical principles. The model is then tested by linear regression with experimental data from glycogen accumulation in Escherichia coli, poly-beta-hydroxybutyrate accumulation in Alcaligenes eutrophus, and sulfur accumulation in Chromatium spp. The model predicts a certain degree of hydration of the polymer in the inclusion and explains both the linear relationship between volume of the cell and weight of the polymer and the hyperbolic relationship between density of the cell and weight of the polymer. Other implications of the model are also discussed.

Alcaligenes↗
PubMed1985

A survey of buoyant density of microorganisms in pure cultures and natural samples.

Values of buoyant density of microorganisms reported in literature are widely divergent because of techniques used. Many of these involve centrifugation in density gradients formed by substances with high osmolarity which dehydrate the cells. In order to better understand the ranges of variation of density of microbial cells several approaches were taken. Firstly, samples from several natural aquatic habitats were taken and the densities of the microorganisms present determined. Secondly, experiments were performed with selected microorganisms to maximize density changes by forcing them to accumulate intracytoplasmic inclusions of dense materials or to loose their capsules. Finally, the relevant literature was reviewed. It could be demonstrated that most microorganisms have a density around 1.080 pg microns-3 when measured in low osmolarity media such as Percoll. However, many species are able to modify their density by as much as 7% (for instance, from 1.097 to 1.022 pg microns-3 in Thiocapsa roseopersicina, and similar variations in other bacteria), by incorporating substances into inclusions (sulfur, carbon, phosphorous storage materials, etc.), or by making capsules and/or gas vesicles. The relevance of buoyant density determinations for several aspects of microbial ecology and physiology is discussed.

Bacteria↗
PubMed1983

Adenosine triphosphate in human semen: a quantitative estimate of fertilizing potential.

The concentration of adenosine triphosphate (ATP) per milliliter of ejaculate was found to be significantly correlated with the following parameters: sperm concentration, number of motile spermatozoa per milliliter, capacity of spermatozoa to migrate against gravity, and in vitro potential to penetrate zona-free hamster ova. The ATP concentration was significantly lower in the semen of infertile men with normal sperm concentration and motility, compared with matched fertile donors. The ATP concentration of deep-frozen donor semen was significantly correlated with its fertilizing potential as estimated from the pregnancy per cycle index in an artificial insemination by donor semen program. These qualities suggest that measurement of semen ATP may be a possible biochemical method for the quantitation of the actual fertilizing potential of the ejaculate.

Adenosine Triphosphate↗