Biomedical subjects

M Delgado

Publications and source records attributed to M Delgado.

At least 127 records · Page 7Linked to original sources

PubMed1997

SUTIL: intelligent ischemia monitoring system.

SUTIL is an intelligent monitoring system for intensive and exhaustive follow up of patients in coronary care units. This system processes electrocardiographic and hemodynamic signals in real time, with the main objective of detecting ischemic episodes. In this paper, we describe the tasks included in SUTIL. In addition to basic tasks, those at higher levels will also be presented. Some of these latter tasks attempt to mimic, to some extent, the way in which the human expert operates.

Algorithms↗

PubMed1997

Interphase arrangement of rye B chromosomes in rye and wheat.

Probes for B chromosome-specific sequences in the distal region of the long arm of the rye B have been used to investigate the interphase arrangement of the Bs in rye and in hexaploid wheat. The Lindström strain of wheat carries the rye Bs as additions. The number of in situ signals in nuclei with two, three and four Bs is often less than the maximum B number, and it seems that the Bs may be grouped together in various ways rather than being randomly dispersed throughout the nucleus. The degree of physical association is greater in rye than in the allen wheat background. The results are discussed in relation to the pairing and recombination preferences of the Bs in rye and in Lindström wheat.

Chromosomes↗

PubMed1997

Gene frequencies of the HPA-1 and HPA-2 platelet antigen alleles among the Amerindians.

BACKGROUND AND OBJECTIVES: Platelet-specific alloantigens are important in neonatal alloimmune thrombocytopenia, posttransfusion purpura, refractoriness to platelet transfusions, and population genetics. Data are scarce on allele frequencies in ethnic groups other than whites and Asians. MATERIALS AND METHODS: Using allele-specific restriction enzyme analysis, we studied the distribution of HPA-1 and HPA-2 alleles in six Brazilian Amazon tribes of Amerindians, belonging to five different language stocks. We compared these with the values obtained for blacks and whites. RESULTS: Only the HPA-1a allele was found among 132 Amerindian chromosomes, compared with a gene frequency of HPA-1b of 0.115 and 0.113, respectively, among blacks and whites. The frequency of HPA-2b among the Amerindians (0.042) is lower than that obtained for blacks and whites (0.148 and 0.100, respectively), and the lowest thus far observed in a population of Asian origin. CONCLUSION: Differences in DNA polymorphisms in Amerindian populations have not only anthropological and genetic interest, but also practical applications when they involve coding regions that may change the functional or immunologic features of the protein.

Alleles↗

PubMed1997

Making the case for culturally appropriate community services: Puerto Rican elders and their caregivers.

This study of the caregiving arrangements of 214 disabled elderly people in a large northeastern city found that the recipients of care were severely disabled, particularly in instrumental activities of daily living, yet had limited sources of informal care and used formal services minimally. The authors discuss the need to use a structural adaptation approach and to develop social services that are culturally sensitive and acceptable to both elders and their caregivers.

Activities of Daily Living↗

PubMed1997

Puerto Rican sons as primary caregivers of elderly parents.

During the past decade the fields of gerontology and social work have paid close attention to Latino elders in the United States. This article reports on the findings of a study examining the needs of Puerto Rican elders in a New England city and the role of sons in the caregiving process. Sons as primary caregivers have not been addressed in depth in the literature. Recommendations are made for social workers working in gerontology to maximize outreach and support to caregiving sons.

Adult↗

PubMed1997

Expression of the Mel1a-melatonin receptor mRNA in T and B subsets of lymphocytes from rat thymus and spleen.

In the present work we analyze by reverse transcription, polymerase chain reaction, cDNA cloning, and sequence analysis the expression of membrane melatonin receptors in rat thymus and spleen. Results show, for the first time, that the melatonin receptor mRNA is expressed in both the thymus and spleen. Moreover, the melatonin receptor mRNA was expressed in all the lymphocyte subpopulations (CD4+,CD8+, double positive, double negative, and B cells) studied from the rat thymus. The Southern blot analysis with the melatonin receptor probe and sequence data also showed the identity of the DNA fragments in thymus, spleen, and the lymphocyte subpopulations studied. The melatonin receptor fragments amplified from rat brain, thymus, and spleen share identical nucleotide sequences with the rat Mel1a-melatonin receptor subtype. No signal was obtained with primers used to amplify the rat Mel1b-melatonin receptor subtype in both thymus and spleen. Finally, the melatonin receptor mRNA transcript distribution throughout the rat thymus was examined. Using digoxigenin-labeled cRNA probe to the specific melatonin receptor mRNA, examination of the whole thymus revealed a clear hybridization signal in both cortex and medulla. Melatonin receptor gene expression in the thymus and spleen supports the notion of the immunomodulatory role of melatonin.

Animals↗

PubMed1997

Thrombus in right atrium in two infants successfully treated with tissue plasminogen activator.

The widespread use of central venous catheters in children has increased thrombotic complications that warrant thrombolytic therapy. We report the cases of two infants, aged four and two months, with a mobile thrombus in the right atrium treated with recombinant tissue-plasminogen-activator (rt-PA) infused by a central venous catheter. Clot dissolution was obtained in both patients in eight and 44 hours, respectively. One patient presented mild respiratory distress probably from a pulmonary microembolism that disappeared in a few days. Both had minor bleeding from venipuncture sites, but no major hemorrhage.

Catheterization, Central Venous↗

PubMed1997

[Pure alexia: presentation of three cases and review of the literature].

INTRODUCTION: Pure alexia is a syndrome characterized by the inability to read aloud in the absence of agraphia or apnasia. CLINICAL CASES: Three clinical cases showing this syndrome are presented. Case I had a left occipital lesion compatible with a subacute haematoma. He had problems with reading, visuo-spatial recognition, digital gnosia and memorizing texts. One year later there was considerable improvement in most of the sub-tests evaluated. There was still deficient colour naming right/left orientation and understanding of letters and words. Case 2 presented with a right homonymous hemianopia and slight left paresis. He had a small left occipital ischaemic infarct. One year later there was improvement on testing, with some deficit still in visual recognition, naming colours and memory. Case 3 presented with right homonymous hemianopia, slight right paresis and a left occipito-parietal expansive lesion. He had defective reading, choosing and naming of colours, right/left orientation and memory. On later evaluation, considerable improvement was seen. There was still colour agnosia, although less severe and mild 'laziness' of the right side. CONCLUSIONS: In the review of the literature, the disorder and the contributions of various authors, from Déperine in 1892 to the present day, are considered in detail.

Aged↗

PubMed1997

Heel blood perfusion responses to pressure loading and unloading in women.

Heel pressure ulcers are significant and costly problems causing suffering and potential limb loss from infection and compromised blood flow. Heel blood perfusion (HBP) deficits accompanying loading likely affect the skin breakdown process, but little is known about the loading and off-loading changes. To clarify this issue, combined laser-Doppler Imaging (LDI) and Fluxmetry were used to assess HBP before, during, and after 40 minutes of continuous heel loading in 11 female volunteers (32-60 years). During loading, an initial decrease in HBP was followed by a gradual small recovery (p < 0.001). Off-loading resulted in a significant hyperemic response with HBP exceeding baseline by a factor of 4.72 +/- 0.63 (p = 0.001) and remaining elevated for about 10 minutes. Spatial LDI data showed that hyperemic responses are maximum near the pressure center and diminish radially. These results suggest a localized, pressure-related tissue trauma, which is compensated for by a substantial hyperperfusion. The dependence (and adequacy) of this response on clinical variables including heel pressure and duration, limb vascular status, and patient health are unknown. The present seminal data and associated methods provide a platform from which these and other important clinical parameters can be systematically studied and compared.

Adult↗

PubMed1997

Variability in skin microvascular vasodilatory responses assessed by laser-Doppler imaging.

Skin blood perfusion (SBP) responses to pressure loading and other traumatic and noxious stimuli are used to help identify patients at-risk of skin breakdown, evaluate preventive strategies and help clarify patho-physiological mechanisms in pre-ulcerative and ulcerative conditions. Often, laser-Doppler methods are used to compare vasodilatory responses at differing skin sites to evaluate skin parameter changes. Significant variations in skin microvasculature are known to be normally present, even in closely separated skin zones. In this study, spatial variability and temporal responses of SBP were evaluated with a widely used topical vasodilator (methylnicotinate, MN). A mask with nine holes (1.25 cm2 each) was placed on the volar forearm of ten volunteers. SBP was measured with laser-Doppler Imaging (LDI) prior to applying MN (15 ul, 50 mM) to six zones and 5, 10, 15, 20 and 30 minutes afterwards. Inter-zone mean SBP and inter- and intra-zone coefficients of variation (CV) were determined at each time. Results show that MN responses, when determined as zone LDI means, reached maximum at 15 minutes with no significant differences in relative responses among treated zones. Inter-zone perfusion CV's (range 0.11-0.13) were about 50 percent of intra-zone CV's (p < 0.01). We conclude that LDI perfusion responses can be obtained at different forearm skin sites with reasonable and acceptable levels of spatial variation if zone mean SBP values are used.

Adult↗

PubMed1996

Vasoactive intestinal peptide and pituitary adenylate cyclase-activating polypeptides (PACAP27) and PACAP38) protect CD4+CD8+ thymocytes from glucocorticoid-induced apoptosis.

In the present study, the effects of vasoactive intestinal peptide (VIP) and the pituitary adenylate cyclase-activating polypeptides, PACAP27 and PACAP38, in a concentration range from 10(-13) to 10(-6) mol/L were studied in vitro on the spontaneous and dexamethasone (DEX)-induced apoptosis in rat thymocytes. The results show that VIP and both PACAPs inhibit significantly and in a similar way the DNA fragmentation characteristic of glucocorticoid-induced apoptosis and increase the cell survival of thymocytes, with a maximal effect observed at 10(-8) to 10(-9) mol/L. This study showed the ability of the VIP-receptor (VIP-R) antagonist [N-Ac-Tyr1,D-Phe2]-GRF(1-29) amide to partially reverse the inhibitory effect of VIP and both PACAPs on DEX-induced apoptosis, providing evidence for a specific VIP1-R-mediated response and supporting the involvement of a single receptor for the three neuropeptides. Phenotypic analysis showed that VIP, PACAP27, and PACAP38 protect predominantly CD4+CD8+ thymocytes from glucocorticoid-induced apoptosis. These findings suggest that these neuropeptides could be involved in intrathymic T-cell maturation.

Animals↗

PubMed1996

Vasoactive intestinal peptide and pituitary adenylate cyclase-activating polypeptide-38 inhibit IL-10 production in murine T lymphocytes.

Vasoactive intestinal peptide (VIP), a neuropeptide present in the peptidergic innervation of lymphoid organs and expressed in thymocytes and peripheral lymphocytes has been previously reported to modulate cytokine expression in T lymphocytes. In this study, we investigated the effects of VIP and of the structurally related neuropeptide PACAP-38 on the expression of IL-10 in murine lymphocyte cultures. Both neuropeptides inhibit IL-10 production by spleen cells or thymocytes activated via the TCR-associated CD3 complex in a similar dose-response manner. The inhibition is specific, presumably mediated through the VIP-R1, and maximum inhibitory levels are achieved within the first 5 to 15 min of exposure to VIP or PACAP-38. CD4+ T cells function as direct cellular targets for the two neuropeptides. The fact that VIP, PACAP-38, and forskolin, all known cAMP inducers, also inhibit IL-10 production, suggests the participation of cAMP in signal transduction. VIP and PACAP-38 regulate transcriptional expression of IL-10, since IL-10 steady state mRNA levels are significantly reduced by treatment with the two neuropeptides. These results expand the range of neuroendocrine-regulated cytokines and support the idea that neuropeptides such as VIP and PACAP, which are released or produced in the local lymphoid microenvironment and specifically modulate the expression of various cytokines, may participate in the intricate cytokine network controlling local immune responses.

Animals↗

PubMed1996

Characterization of gene expression of VIP and VIP1-receptor in rat peritoneal lymphocytes and macrophages.

In the present report we show the gene expression pattern of VIP and VIP1 receptor in two peritoneal cell populations, macrophages and lymphocytes by reverse transcription (RT) and polymerase chain reaction (PCR). Only in the lymphoid cells we have obtained a specific VIP cDNA product of 458 bp identical in size to the one obtained from cerebral cortex. On the other hand, we have obtained in both peritoneal populations lymphocytes and macrophages, a specific VIP1 receptor cDNA product of 311 bp identical in size to that obtained from lung. These results have been confirmed by Southern blot hybridization. Our findings suggest an autocrine/paracrine action of VIP in peritoneal microenvironment, supporting an immunoregulatory role for this neuropeptide.

Animals↗

PubMed1996

Painting rye B chromosomes in wheat: interphase chromatin organization, nuclear disposition and association in plants with two, three or four Bs.

The B chromosomes (Bs) of rye (Secale cereale) have been studied at interphase in terms of their chromatin organization, patterns of nuclear disposition and physical association in plants with two, three, and four Bs. The study was made in the Lindström strain of hexaploid wheat, which carries the rye Bs as an addition line, by in situ hybridization with a B-specific probe and by genomic in situ hybridization (GISH) with rye genomic DNA, enabling whole chromosome painting. Repetitive sequences common to the As and Bs of rye allow for visualization of the rye B at interphase in the wheat background. A B-specific probe enables the orientation of two or more Bs to be determined, and the combination of both probes used together gives information on the disposition of the Bs and on their patterns of physical association within the nucleus. The Bs form linear "strings', and the ends of their long arms, which can be detected by the B-specific probe, are usually located within the hemisphere of the nucleus that has the least condensed chromatin. There is dose-dependent association, and even numbers (2B, 4B) have a greater preference for association than odd ones (3B).

Chromatin↗

PubMed1996

Differential expression of vasoactive intestinal peptide receptors 1 and 2 (VIP-R1 and VIP-R2) mRNA in murine lymphocytes.

Vasoactive intestinal peptide (VIP), a neuropeptide present in the lymphoid microenvironment, modulates cytokine expression and affects T cell proliferation. Recent molecular studies identified two VIP receptors. VIP-R1 and VIP-R2, primarily in nonlymphoid cells. In this study, we investigate the expression of VIP-R1 and VIP-R2 mRNA in unstimulated and stimulated lymphocytes and thymocytes, and in various lymphocyte subpopulations. In contrast to VIP-R1 which is constitutively expressed, the expression of VIP-R2 is induced only following stimulation through the TCR-associated CD3 complex. Both CD4+ and CD8+ T cells express VIP-R1 and VIP-R2. Two T cell lines, EL-4.IL-2 and D10.G4.1 express exclusively VIP-R2. VIP induces the expression of the VIP-R2 gene in the absence of additional stimuli. Differential expression and regulation of the two VIP receptors in T lymphocytes suggests different physiological roles in mediating the immunomodulatory activities of VIP and related neuropeptides.

Animals↗

PubMed1996

Murine T-lymphocytes express vasoactive intestinal peptide receptor 1 (VIP-R1) mRNA.

Vasoactive intestinal peptide (VIP), a neuropeptide present in primary and secondary lymphoid organs has been previously reported to inhibit IL-2 and IL-4 production as well as the proliferation of mitogen- or antigen-stimulated T-cells. Binding studies suggested that the immunoregulatory effects of VIP are mediated through specific VIP-binding sites present on lymphocyte subpopulations. Here we report on the expression of VIP-R1 mRNA in various murine lymphocyte subpopulations. By using RT-PCR. RNase protection assay, cDNA cloning, and sequence analysis, we show that stimulated and unstimulated murine spleen cells, thymocytes. CD4+ and CD8+ T-cells express VIP-R1. The VIP-R1 fragment amplified from murine brain, thymocytes, spleen cells and CD4+ T-cells share identical nucleotide sequences, and a high degree of homology with the corresponding nonlymphoid rat and human VIP-R1 sequences. The expression of VIP-R1 in thymocytes and peripheral lymphocytes, and especially in the CD4+ T-cell subset supports the idea that VIP produced or released locally in the lymphoid microenvironment could directly affect cytokine production and proliferation of T-lymphocytes.

Animals↗

PubMed1996

Differential VIP and VIP1 receptor gene expression in rat thymocyte subsets.

Nervous, endocrine, and immune systems share a large number of regulatory molecules including hormones and neuropeptides. Vasoactive intestinal peptide (VIP) plays an important role in a variety of immunological functions. In the present report, we sorted purified thymocytes of the four major thymic subsets defined by CD4 and CD8 phenotypes. We demonstrate by reverse transcription (RT) and polymerase chain reaction (PCR) both VIP and VIP1 receptor gene expression in double positive (CD4+CD8+) and single positive (CD4+CD8-, CD4-CD8+) thymocyte subsets. Double negative thymocytes (CD4-CD8-) lack VIP and VIP1 receptor gene expression.

Animals↗

PubMed1996

Pituitary adenylate cyclase-activating polypeptide (PACAP38) modulates lymphocyte and macrophage functions: stimulation of adherence and opposite effect on mobility.

The effects of pituitary adenylate cyclase-activating polypeptide (PACAP38) in a concentration range from 10(-13) to 10(-6) M were studied, in vitro, on two functions of peritoneal rat lymphocytes and macrophages: adherence and mobility (spontaneous and chemotaxis). The results show that PACAP38 raised the adherence of the two cell types, increased the mobility of macrophages and decreased the mobility of lymphocytes. The maximal effects were observed at 10(-10) M in macrophages and at 10(-9) M in lymphocytes. Moreover, incubation with increasing concentrations of phorbol myristate acetate (PMA), a protein kinase C (PKC) activator, resulted in a progressive enhancement of adherence and chemotaxis of both macrophages and lymphocytes. In contrast, retinal, a PKC inhibitor, significantly decreased these capacities. Incubation of macrophages with both PMA and PACAP38 did not have a synergistic effect on chemotaxis and adherence whereas, with lymphocytes, adherence was increased and chemotaxis was partially decreased. On the other hand, incubation with forskolin (an enhancer of intracellular cyclic AMP [cAMP] levels) caused inhibition and stimulation of chemotaxis and adherence, respectively, in both cell types. PACAP38 prevented the inhibitory effect of forskolin on chemotaxis of macrophages but not of lymphocytes, whereas the simultaneous presence of PACAP38 and forskolin was synergistic for adherence of both peritoneal cells. In addition, PACAP38 was chemoattractant for macrophages but not for lymphocytes. Furthermore, a VIP receptor antagonist was able to partially reverse the modulatory effects of PACAP38 on lymphocytes, but not on macrophages. These data suggest that PACAP38 exerts its action through the binding to type I PACAP receptors and PKC activation in macrophages and through the elevation of intracellular cAMP levels by binding to type II PACAP receptors in lymphocytes. The present work reveals an additional link between neuropeptides and the immune system and suggests that the peptide PACAP modulates the immunological function of macrophages and lymphocytes.

Animals↗