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Biomedical subjects

R Ramírez

Publications and source records attributed to R Ramírez.

At least 109 records · Page 6Linked to original sources

[Incidence of neoplasms in non-congenital refractory anemias. Ferrokinetic pattern].

Twenty cases of refractory anemia were studied by means of ferrokinetic analysis with Fe-59. An accelerated plasma clearing, a diminished iron uptake by red cells, and a decreased bone marrow activity were found. Half of the cases showed secondary liver and spleen hemochromatosis. The incidence of malignant tumors observed in the studied refractory anemias was 35% (7 out of 20 cases, corresponding to 4 solid tumors and 3 leukemias). The authors suggest the convenience to study erythropoiesis in anemias with an obscure origin using the ferrokinetic procedure with Fe-59.

Adult↗

Structural levansucrase gene (lsdA) constitutes a functional locus conserved in the species Gluconacetobacter diazotrophicus.

Levansucrase (EC 2.4.1.10) was identified as a constitutive exoenzyme in 14 Gluconacetobacter diazotrophicus strains recovered from different host plants in diverse geographical regions. The enzyme, consisting of a single 60-kDa polypeptide, hydrolysed sucrose to synthesise oligofructans and levan. Sugar-cane-associated strains of the most abundant genotype (electrophoretic type 1) showed maximal values of levansucrase production. These values were three-fold higher than those of the isolates recovered from coffee plants. Restriction fragment length polymorphism analysis revealed a high degree of conservation of the levansucrase locus (IsdA) among the 14 strains under study, which represented 11 different G. diazotrophicus genotypes. Targeted disruption of the lsdA gene in four representative strains abolished their ability to grow on sucrose, indicating that the endophytic species G. diazotrophicus utilises plant sucrose via levansucrase.

Acetobacteraceae↗

[Validity of hand-held systems for otoacoustic emissions in hearing screening].

Hearing screening objective is the development of an universal screening. With that purpose, new hand-held system of Otoaccoustic Emissions have been designed, which are easier to perform and to interpret the results, to detect hearing loss disordersas soon as possible. To validate the hand-held systems of Otoaccoustic Emissions in the hearing screening, we have compared the results of the tests with Otoaccoustic Emissions clinic systems and tonal audiometry in two groups of population: new-borns and hearing-loss adults aged between 16 and 56. Our study showed that the hearing screening results in children with hand-held system were similar to classic Otoaccoustic Emissions system, but there were more than 40% of adult hearing losses not detected with this system. These results can invalidate the test.

Adolescent↗

From value chain to value constellation: designing interactive strategy.

In today's fast-changing competitive environment, strategy is no longer a matter of positioning a fixed set of activities along that old industrial model, the value chain. Successful companies increasingly do not just add value, they reinvent it. The key strategic task is to reconfigure roles and relationships among a constellation of actors--suppliers, partners, customers--in order to mobilize the creation of value by new combinations of players. What is so different about this new logic of value? It breaks down the distinction between products and services and combines them into activity-based "offerings" from which customers can create value for themselves. But as potential offerings grow more complex, so do the relationships necessary to create them. As a result, a company's strategic task becomes the ongoing reconfiguration and integration of its competencies and customers. The authors provide three illustrations of these new rules of strategy. IKEA has blossomed into the world's largest retailer of home furnishings by redefining the relationships and organizational practices of the furniture business. Danish pharmacies and their national association have used the opportunity of health care reform to reconfigure their relationships with customers, doctors, hospitals, drug manufacturers, and with Danish and international health organizations to enlarge their role, competencies, and profits. French public-service concessionaires have mastered the art of conducting a creative dialogue between their customers--local governments in France and around the world--and a perpetually expanding set of infrastructure competencies.

Commerce↗

Changes in the number, proliferation rates, and bcl-2 protein immunoexpression of epithelial and periductal cells from rat epididymis during postnatal development.

To investigate 1) the correlation between the proliferative activity of epididymal epithelium plus myoid cells and the increase in the number of these cells and 2) the role of the basal epithelial cells in the renewal of epididymal epithelium, a quantitative evaluation of the proliferation of both epithelial cells and periductal myoid cells in the different epididymal regions (caput, corpus, and cauda) has been carried out during postnatal development of the rat by immunohistochemical evaluation of BrdU-labeling indices. These data were correlated with cell numbers and counted by the optical dissector method. The presence of bcl-2 protein was immunohistochemically detected and evaluated. No significant differences in BrdU indices were observed among epididymal regions in any stage studied. Cell proliferation decreased from the prepubertal period to adulthood in both epithelial and myoid cells in the three regions of the epididymis, suggesting a close relationship between epithelial and mesenchymal components. The numbers of both cell types were significantly higher in the caput than in the corpus and cauda in all stages studied, suggesting functional differences between regions. A negative linear correlation between proliferative activity and cell numbers was noted that might be related to regulation of the cell population size. Basal cells showed a lower proliferation rate than principal cells, but most of the immunoreactive bcl-2 protein, in pubertal and adult epididymides, was observed in basal cells. Therefore, these cells might comprise a low-proliferating and apoptosis-resistant population.

Aging↗

[Cerebral hemorrhage in full term newborns].

INTRODUCTION: Cerebral hemorrhages in full-term newborn babies are an important factor in neonatal morbidity and mortality and very frequent in premature babies. In full-term newborn the frequency is reduced to 1-2% and the aetiopathogenesis is basically related to birth trauma. OBJECTIVE: To identify the clinical forms of cerebral hemorrhages in full-term newborn before taking prophyllactic and/or therapeutic measures if possible. DEVELOPMENT: Based on the integrated physio-pathological model of Wigglesworth and Pape, two anatomo-pathological patterns were established according to gestational age. Topographic classification was done in full-term newborn according to site (subarachoid, subdural, intraventricular, cerebellar and intraparenchymatous). We studied the pathogenesis, clinical features and diagnosis of each of these sites and emphasize the importance of neuroimaging. CONCLUSIONS: The diagnostic approach proposed permits an aetiopathogenic and therapeutic view which currently permits improved prognosis and even cure in many cases.

Cerebral Hemorrhage↗