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Biomedical subjects

J Moreno

Publications and source records attributed to J Moreno.

At least 127 records · Page 7Linked to original sources
PubMed1997

CENP-B autoantigen is a conserved protein from humans to higher plants: identification of the aminoterminal domain in Phaseolus vulgaris.

Centromeres are critical structures in cell division, and CENP-B is the most important protein of the centromeric complex recognized by autoantibodies from patients with scleroderma. Our major aim was to demonstrate whether CENP-B is a conserved protein along the phylogenic scale including the higher plants. Vegetal and human cell proteins were extracted from Phaseolus vulgaris and HEp-2 cells and were characterized by PAGE, Western blot, and human autoimmune sera containing anti-CENP-B autoantibodies. The aminoterminus of the gene encoding for CENP-B from HEp-2 cells and Phaseolus vulgaris was isolated by reverse transcriptase-PCR using complementary oligonucleotides to the human CENP-B gene. Also, in situ hybridization was performed on vegetal tissues and HEp-2 cells using human CENP-B box probes. Our main results were as follows: 1) Autoimmune sera were reactive to a vegetal protein of 80 kDa. 2) Affinity-purified anti-CENP-B antibodies recognized a protein from Phaseolus vulgaris with molecular mass similar to that found in human cells. Vegetal and HEp-2 cells CENP-B proteins were immunologically identical. 3) Using RT-PCR, we were able to amplify a cDNA encoding for the aminoterminus domain of CENP-B from Phaseolus vulgaris that had the same molecular behaviour as the cDNA from HEp-2 cells. 4) Complementary oligonucleotides for human CENP-B box hybridized a DNA sequence from Phaseolus vulgaris. In conclusion, CENP-B protein is a conserved protein along the phylogenic scale from humans to higher plants.

Antibody Specificity↗
PubMed1996

Maternal effort mediates the prevalence of trypanosomes in the offspring of a passerine bird.

The relationships between parental effort, offspring growth, and offspring blood parasitemias are poorly known. We examined the effect of parental effort on offspring size and prevalence of trypanosomes in peripheral blood of nestling Pied Flycatchers Ficedula hypoleuca aged 13 days. Trypanosome infections were likely to be shared by siblings, indicating the role of a common environment and/or shared genes in the susceptibility to infection. Broods infected by trypanosomes had reduced growth, but this was due to decreased parental, especially maternal, energy expenditure in broods with nestlings infected by trypanosomes. There was no association between parental infection with trypanosomes and both their energy expenditure and the infection of their broods. Under stressful conditions caused by low maternal energy expenditure, the immune response of nestlings during growth was probably impaired, in a way analogous to the relapses of blood parasitemias with reproductive effort in breeding animals.

Animals↗
PubMed1996

[NO and NO2 concentration curves in mixtures for clinical use].

Inhaled nitric oxide (NO) allows us to achieve selective pulmonary vasodilatation. The purpose of the present experimental study was to determine the concentrations of NO and NO2 produced by mixing two well-known and variable flows of 100% oxygen and 800 ppm NO, in a low or normally humid environment, as well as in a humid one. The mixture of NO and N2 is introduced by means of a standard low-flow blender (0.2 to 1 liter/minute) in the inspiratory tube of a ventilator at a distance of about 20 cm from the connection with the artificial lung. In order to obtain a humid circuit, we used a humidifier servocontrolled at a temperature of 36 degrees C. The concentration of NO and NO2 are continually determined by means of chemiluminescence in the expiratory tube at about 5 cm from the connection with the artificial lung. The study consisted of three parts: elaboration of the curves of NO and NO2 in low humidity (34 measurements), validity of the corresponding curves of NO in low humidity (80 new measurements) and elaboration of the curves of NO and NO2 in a humid circuit (32 measurements). We found that the concentrations of NO in low humidity follow a lineal equation, except for the flows lower than 10 L/min. Flows between 10-15 L/min reached concentrations of NO between 6-60 ppm. The concentrations of NO2 in low humidity produced some parallel curves, and exceptionally overcame the toxic figure of 5 ppm. The curves are valid only with flows higher than 10 L/min. Humidity does not influence the NO concentrations, while it diminishes NO2 concentrations 1.4 times.

Administration, Inhalation↗
PubMed1996

[Massive hemoptysis associated with tracheopathia osteochondroplastica].

A patient with a history of recurrent respiratory infections and hemoptysis due to tracheopathia osteochondroplastica is presented. Two aspects are highlighted. On the one hand, the fact that this entity is still, frequently, an unexpected finding at fiberoptic bronchoscopy. On the other hand, the possibility of massive hemoptysis complicating the carrying out of fiberoptic bronchoscopic examination in this process.

Aged↗
PubMed1996

Morphogenesis of the epithelial cell transporting phenotype: synthesis and distribution of ion channels.

The exchange of substances between higher organisms and the environment takes place across epithelia consisting of one or more cell layers. To perform this function, epithelial cells have two basic differentiated properties: 1) they form tight junctions (TJs) that seal the extracellular space, and 2) they are polarized into an apical and a basolateral domain, with entirely different structural, biochemical and physiological properties. Our understanding of the mechanisms involved in the expression of these properties has been greatly enhanced by the availability of epithelial cell lines that form TJs and polarize in vitro under conditions suitable for experimental control. In this article we summarize our studies on the synthesis and polarized expression of ion channels in epithelial cells. MDCK cells have four types of K+ channels in the apical domain, and a fifth one in the basolateral domain. The basolateral side also has a population of CI- channels. Each type of channel is absolutely polarized. Harvesting with trypsin-EDTA reduces the area of the plasma membrane by 50% and the channel population by 90%. Upon plating, these channels are recovered within a few hours. We describe here the main extracellular and intracellular mechanisms involved in these phenomena.

Animals↗
PubMed1995

T-dependent areas in the chicken bursa of Fabricius: an immunohistological study.

BACKGROUND: The so-called diffusely infiltrated lymphoid tissue of the chicken bursa of Fabricius was previously described as a T-dependent bursal area. METHODS: We have analyzed immunohistologically its postnatal development by using a battery of mAbs, most of them raised specifically to chicken T cells, in order to characterize phenotypically the nature of its cell components, appearance, development, and possible functional significance. RESULTS: Our results demonstrate that this tissue represents poorly developed lymphoid aggregates, the cell content reminiscent of that found in other lymphoid tissues occurring throughout the avian gut. The first lymphoid elements appear in this bursal area only after hatching, growing rapidly to reach the adult condition in the second week of postnatal life. They consist mainly of T lymphocytes, including principally. CD4+ TcR alpha V beta 1+ cells, which form cell groups and CD8+ cells, and TcR gamma delta+ lymphocytes, which predominate in the subepithelial area and within the epithelium. MHC Class II molecule-expressing cells and IgM-, IgG-, and IgA-positive B lymphocytes also occupy the subepithelial region. CONCLUSIONS: We propose that the bursal diffusely infiltrated lymphoid tissue of the chicken represents gut-associated lymphoid tissue involved in mounting immune responses to antigens that reach the bursal lumen via the cloaca.

Animals↗
PubMed1995

Biophysical models as an approach to study passive absorption in drug development: 6-fluoroquinolones.

A preliminary study attempting to assess and explain the intestinal absorption of a series of antibacterial 7-piperazinyl-6-fluoroquinolones is presented. The synthesis, n-octanol partition coefficients, intrinsic rat gut in situ absorption rate constants, and in vitro antibacterial activity data found for these homologous compounds are described. A fluorimetric, reverse-phase HPLC method was performed for the quantification of the quinolones in absorption and partition samples. Equations based on two classic biophysical absorption models are given for predicting the intrinsic absorption features of the series according to the partition data or merely single structural parameters. In situ absorption rate constants were found to increase by a factor of 9.7-13.5 for moderately lipophilic derivatives relative to the simplest compound, while antibacterial activity decreased only by a factor of 4. In vivo absorption tests with two representative members of the series were carried out and the results showed a good accordance with those found in situ. This makes these compounds or related ones with similar partition features excellent candidates for further pharmacokinetic and pharmacological testing. The study can serve as an example of how to prevent potential absorption problems associated with the development of new drugs.

Administration, Oral↗
PubMed1995

Comparison of the onset and duration of the analgesic effect of dipyrone, 1 or 2 g, by the intramuscular or intravenous route, in acute renal colic.

In a double-blind, double-dummy randomized controlled clinical trial, the onset and duration of the analgesic effect of dipyrone, 1 or 2 g, and diclofenac sodium, 75 mg, by either the i.m. or the i.v. route were compared in 293 patients (aged 18-70 years) with acute renal colic. A level of > or = 50 mm on the 100-mm visual analogue scale was required for inclusion in the study. Patients were randomly allocated to six treatment groups, receiving dipyrone 1 g i.m., dipyrone 1 g i.v., dipyrone 2 g i.m.;, dipyrone 2 g i.v., diclofenac sodium 75 mg i.m.; and diclofenac sodium 75 mg i.v., respectively. Evaluations were performed at 10, 20, 30, and 60 min and 2, 4, and 6 h after treatment (time 0). Primary efficacy end points included course of pain, total pain, percentage of patients with a pain improvement of 50% or more at each evaluation time, pain intensity evaluated by the investigator on a 0-3 scale, and differences in pain intensity. The analgesic response was more marked and prolonged among patients receiving dipyrone 2 g i.m. or dipyrone 2 g i.v. There were no significant differences between dipyrone 1 g and diclofenac sodium 75 mg, by either the i.m. or the i.v. route. All treatment regimens were well tolerated.

Adult↗
PubMed1995

Efficacy of doramectin in the protection of neonatal calves and post-parturient cows against field strikes of Cochliomyia hominivorax.

Two studies were conducted in Latin America, one in Venezuela and one in Argentina, using a common protocol to investigate the efficacy of a single s.c. injection of doramectin in the prevention and control of field infestations of Cochliomyia hominivorax in newborn calves and post-parturient cows. In both experiments, pregnant cows were paired on the basis of their calving time. The first cow that calved was assigned to a medicated group, and both cow and calf were treated with doramectin. The cow received a dose of 200 micrograms kg-1 and the calf 1 ml of a 1% doramectin solution. The second cow and calf were assigned to a saline-treated group, and the cow received saline at 1 ml per 50 kg and the calf 1 ml. The procedure was repeated until all animals were allocated to the two treatments. Animals were examined on the treatment day and at 2, 4, 6 and 12 days post-treatment. At each observation day, the navel of newborn calves and external genitalia of the cows were inspected and the presence of C. hominivorax infestations was recorded. Doramectin was 100% effective in the prevention and control of screwworm strikes in newborn calves and in post-parturient cows exposed to continuous field challenge of C. hominivorax. Over the 12 day duration of the studies, 48% and 57% of the saline-treated calves had screwworm navel strikes in the studies in Venezuela and Argentina, respectively. Infested animals required repeated therapeutic treatment, whereas none of the doramectin-treated calves were affected (P < 0.005).(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1995

Efficacy of injectable doramectin in the protection of castrated cattle against field infestations of Cochliomyia hominivorax.

Three studies were conducted in Latin America--one in Venezuela, one in Argentina and one in Brazil--using a common protocol to investigate the efficacy of a single subcutaneous injection of doramectin in the prevention and control of Cochliomyia hominivorax infestations in castrated cattle. In each study, two groups of 20-28 animals each were allocated to a treated (T1) or to a control (T2) group on the basis of body weights. Animals of T1 received doramectin at 200 micrograms kg-1 (1 ml per 50 kg) and animals of T2 received saline solution at 1 ml per 50 kg of live weight. After treatment all cattle were castrated surgically. Animals were examined on treatment day and at 2, 4, 6 and 12 days post-treatment. At each observation day, the presence of C. hominivorax infestations was recorded. Doramectin was 100% effective in the prevention and control of screwworm strikes in castrated cattle exposed to continuous field infestations of C. hominivorax in tropical and subtropical areas of Latin America. Over the 12 day duration of the studies, 85%, 60% and 65% of animals in the control groups had infested wounds in Venezuela, Argentina and Brazil, respectively. Affected animals required repeated therapeutic treatment, whereas none of the doramectin-treated cattle were infested (P < 0.0001). A high proportion of the castration wounds in doramectin-treated cattle had the presence of characteristic C. hominivorax eggs but none developed into larvae. There were no clinical signs of adverse reactions to treatment in any of the three studies.

Animals↗
PubMed1995

Efficacy of injectable doramectin in the therapy and control of Dermatobia hominis infestations in Latin America.

Three studies were conducted in Latin America, one in Brazil, one in Venezuela and one in Argentina, using a common protocol to investigate the efficacy of a single subcutaneous injection of doramectin at 200 micrograms kg-1 (1 ml per 50 kg) for the treatment and control of Dermatobia hominis infestations in cattle raised under commercial conditions. In each study, two groups of 20 animals each were allocated on the basis of D. hominis nodules present 24 h before treatment to a treated group (T1), or to a control group (T2) which received saline solution at 1 ml per 50 kg of live weight. All cattle were injected in the mid-dorsal cervical region and examined on treatment day and 2, 7, 15 and 30 days post-treatment (p.t.). At each observation day the number of D. hominis nodules was counted and the viability of the larvae inside them was assessed and recorded. Treatment with doramectin was 100% effective in eliminating D. hominis larvae and in controlling the re-establishment of the parasite under field conditions of continuous reinfestation. During the first 48 h p.t., dead larvae of different ages were found outside or partially outside the nodules in animals of the doramectin groups. After 48 h p.t., no live larvae were found inside existing nodules, nor did new nodules develop in animals of the doramectin groups in any of the three studies. When compared with nodule counts in the control group on the same observation day or with parasite burdens on the same animal before treatment, doramectin-treated animals began to eliminate parasitic nodules at 48 h p.t. Efficacy reached 100% at 7 days p.t. and remained at 100% on subsequent observation days (P < 0.05). None of the doramectin-treated animals exhibited any clinical signs of adverse reaction to medication.

Animals↗
PubMed1995

T-cell development in early partially decapitated chicken embryos.

We have evaluated the immunohistological and cytofluorometric changes that occur in the thymus of chicken embryos partially decapitated at 33-38 hr of incubation (DCx embryos) in an attempt to analyze possible neuroendocrinological influences on T-cell differentiation and, indirectly, the ontogeny of the so-called neuroendocrine-immune network. The thymus of DCx embryos shows important variations that profoundly and selectively affect different T-cell subsets, but not the nonlymphoid cell components of thymic stroma. These modifications include the accumulation of cell precursors, mainly DN (CD4-CD8-) cells and immature CD8lowCD4- cells, which expand but do not differentiate, resulting in an extreme decline of both DP (CD4+ CD8+) cells and TcR alpha beta-expressing cells. Accordingly, both subcapsulary and outer cortex increase in size, whereas the deep cortex and principally the thymic medulla almost disappear in DCx embryos. In contrast, other T-cell subsets of DCx embryos, largely CD8highCD4- cells and TcR gamma delta-expressing cells do not undergo significant variations throughout thymic ontogeny.

Animals↗
PubMed1995

Phosphorylation profiles of 60 kD Ro antigen in synchronized HEp-2 cells.

The purpose of this study was to determine whether phosphorylation has an effect on the characteristics of the 60 kD Ro antigen throughout the cell cycle. Cell extracts of synchronized HEp-2 cells were phosphorylated in vitro with exogenous ATP, examined by SDS-PAGE and Western blot, and probed with specific anti-Ro sera. In addition, cellular ATP pools were radiolabelled in vivo with 32P. The presence of the Ro protein was detected with a molecular weight of 60 kD during all phases of the cell cycle, except at the M phase, where it was increased to 65 kD. Phosphorylation of the in vitro and in vivo cell extracts increased the molecular mass to 65 kD. Moreover immunoprecipitation assays demonstrated that Ro is hyperphosphorylated in the M phase. Phosphorylation did not change the recognition pattern of the anti-Ro sera.

Antibody Specificity↗
PubMed1995

Ontogeny of rat thymic macrophages. Phenotypic characterization and possible relationships between different cell subsets.

In the present study we combined electron microscopy, immunohistology and primary stromal cell cultures to analyse the ontogeny of rat thymic macrophages (M phi) in an attempt to clarify the relationships between the different macrophage cell subsets described in adult rat thymus. Although phagocytic cells were observed in 15-day-old fetal thymus, monoclonal antibodies (mAb) which recognize different adult macrophage types were unable to identify positive cells until the end of embryonic life. However, our in vitro results from primary thymic stromal cell cultures of 16-day-old fetal rats, and the phenotyping of enriched thymic CD2- cell suspensions, demonstrated that monocyte-like cells which strongly expressed major histocompatibility complex (MHC) class II molecules colonized the embryonic thymus early, giving rise later to distinct macrophage subsets. During the process of maturation, macrophage precursors gradually lost their MHC class II expression, acquired other surface markers (CD45, Thy-1, CD25, CD4, etc.) and increased the acid phosphatase activity. In this respect, ED1+ macrophages, which appeared for the first time in the last stages of embryonic life, consisted of a MHC class II molecule-expressing phagocytic cell population, presumably involved in the elimination of non-selected cortical thymocytes, and of non-phagocytic cells which, in the thymic cortex, might differentiate to ED2+ macrophages throughout ED1+ED2lo/med and ED1+ ED2high intermediate cell stages, observed in vitro in 16-day-old fetal thymic stromal cell cultures. At the end of embryonic life and during the postnatal period the numbers of thymic macrophages increased, particularly in the medulla and corticomedullary border (CMZ), and more slowly in the thymic cortex. This increase was presumably due to the arrival, through perivascular spaces, of new macrophage progenitors, rather than in situ proliferation of pre-existent mature macrophages. The possible function of different thymic macrophage subsets, as well as the relationships between themselves and with their presumptive monocyte-like precursors, are discussed.

Animals↗