Biomedical subjects

M Delgado

Publications and source records attributed to M Delgado.

At least 145 records · Page 8Linked to original sources

PubMed1996

Pituitary adenylate cyclase-activating polypeptide (PACAP-38) stimulates rat peritoneal macrophage functions.

The present study shows that PACAP-38, in a dose-dependent manner, increased in vitro two steps of the phagocytic process in rat peritoneal macrophages: ingestion of inert particles (latex beads) and production of superoxide anion as measured by nitroblue tetrazolium reduction. The most effective concentration of PACAP-38 was 10(-10) M. Similarly, PMA, an activator of protein kinase C (PKC), increased the phagocytic activity in a dose-dependent manner, whereas retinal, a PKC inhibitor, decreased the activity. Macrophages incubated with forskolin, an enhancer of intracellular cAMP levels, produced an inhibitory effect on both phagocytic functions. The maximum stimulation of the phagocytic activity by PACAP-38 was not further enhanced by addition of PMA, suggesting that the enhancement of the phagocytic activity by PACAP-38 and PMA is mediated by a common signaling pathway. In addition, retinal as well as forskolin inhibited partially the stimulatory effect that PACAP-38 produced in the macrophage functions studied. Furthermore, this study showed that a VIP receptor antagonist was unable to suppress the stimulatory effect of PACAP-38. These results could prove that PACAP-38 stimulates the phagocytosis and production of superoxide anion in macrophages through PKC activation by binding to type I PACAP receptor.

Animals↗

PubMed1996

Expression of vasoactive intestinal peptide in lymphocytes: a possible endogenous role in the regulation of the immune system.

Experimental evidence is accumulating showing that vasoactive intestinal peptide (VIP) acts as an immunoregulatory peptide. Findings from our laboratory and others indicate that cells of the immune system are able to produce VIP. We have detected immunoreactivity for VIP in lymphocytes by immunohistochemical methods at specific locations of both central and peripheral lymphoid organs. Double immunofluorescence staining and flow cytometry analysis indicate that both T and B lymphocytes contain VIP that has been proved to be mostly VIP 1-28 by high-performance liquid chromatography and radioimmunoassay. VIP has been also demonstrated by 'in situ' hybridization and reverse transcription followed by polymerase chain reaction. We have also detected induction of VIP in splenic lymphocytes after mitogenic stimulation. Lymphocytes should be sensitive to the endogenously produced VIP because we have also detected VIP receptor expression in different populations of lymphocytes. All this evidence indicates that VIP is an endogenous autocrine modulator of immune function.

Animals↗

PubMed1996

VIP modulation of immune cell functions.

Neuropeptides have recently been shown to modulate the immune response. Vasoactive intestinal peptide (VIP) released from nerve endings and from immune cells modulates the mobility and adherence of lymphocytes and macrophages, phagocytic cell functions (phagocytosis and free radical production), the lymphocyte proliferative response, lymphokine and immunoglobulin production and the natural killer cell activity, with opposite effects in vitro on these immune cell functions. The VIP receptor heterogeneity and the different action mechanisms of VIP-mediated immunoregulation could explain, at least in part, the different VIP effects observed on lymphoid and phagocytic cells. The evidence supports the theory that VIP acts not as an inhibitor, but as a modulator of immune functions, as previously thought, and that this neuropeptide may play a relevant role in vivo.

Adjuvants, Immunologic↗

PubMed1996

MHC class I antigens and tumour-infiltrating leucocytes in laryngeal cancer: long-term follow-up.

Alteration in MHC class I expression may be used by cancer cells to avoid immune destruction. Much experimental evidence supports this idea, although survival studies are very scarce. To investigate whether the presence or absence of HLA-A, -B and -C antigens in laryngeal carcinoma influences survival, a series of 60 primary laryngeal tumours treated surgically and normal tissues were evaluated in frozen sections for the expression of MHC class I antigens and tumour-infiltrating leucocytes (CD3, CD4, CD8, CD11b, CD1, CD20 and CD16), using monoclonal antibodies and the APAAP, technique. Long-term follow-up from the patients is available, ranging from 6 to 10 years. Thirteen tumours presented total HLA-ABC loss, five selective losses of HLA-A antigens and one absence of HLA-B antigens. Total losses were statistically associated with several clinical and pathological parameters, but there were no differences regarding tumour-infiltrating leucocytes. After conducting a prospective study, only T and N staging and scoring according to Glanz's malignancy classification were found to be independently related to patients' outcome. From our data, we conclude that neither complete loss of HLA class I antigens nor tumour-infiltrating leucocytes appear to influence survival in squamous cell carcinoma of the larynx.

Adult↗

PubMed1996

Aging research and the Puerto Rican community: the use of an elder advisory committee of intended respondents.

This article reports on the use of a Puerto Rican Elder Advisory Committee and the role it played in the development and implementation of a four-year research project. The use of an advisory committee composed of the ultimate beneficiaries of a study increases the likelihood that the results will meet their needs. This article provides suggestions for how best to utilize this important resource in all phases of a research project.

Aged↗

PubMed1996

Equivalent outcomes during postoperative patient-controlled intravenous analgesia with lidocaine plus morphine versus morphine alone.

To evaluate a possible opioid-sparing effect of intravenous lidocaine we conducted a randomized, double-blind clinical trial. Patients undergoing intraabdominal surgery under general anesthesia were treated with patient-controlled analgesia (PCA) in three groups: Group 1 (n = 100; morphine 1 mg/mL), Group 2 (n = 44; morphine 1 mg/mL plus lidocaine 10 mg/mL), and Group 3 (n = 51; morphine 1 mg/mL plus lidocaine 20 mg/mL). Pain was evaluated using a 0-10 visual analog scale in the postanesthesia care unit (PACU) during deep inhalation at 15 and 30 min, and at 1, 2, and 4 h after arrival in the PACU, and continued after PACU discharge every 4 h for 36 h. Patients whose pain was more than 4/10 in the PACU received 2.5 mliters of the respective solutions every 7 min until pain was less than 4/10; then PCA was started. The number of bolus and cumulative drug doses during the study were recorded. Along with pain intensity, we assessed vital signs and side effects. Time to acceptance of oral liquids was also determined. Adding lidocaine 10 or 20 mg/mL to PCA morphine 1 mg/mL for acute pain treatment after abdominal surgery yielded no differences in opioid use, pain levels, or side effects.

Adolescent↗

PubMed1996

Complications associated with Brucella melitensis infection: a study of 530 cases.

We carried out a prospective study of 530 patients older than 14 years of age with brucellosis. We describe the incidence and clinical features of the focal forms of the disease, analyzing some of the possible factors associated with their appearance. One hundred sixty-nine patients (31.9%) had a focal form or complication. Osteoarticular complications were the most frequent, totaling 113 cases (66%), followed by genitourinary with 18 cases (5.1% of males), hepatic (2.5%), neurologic (1.7%), and heart (1.5%). Nine patients (1.7%) had more than 1 complication. In a multivariate analysis, diagnostic delay greater than 30 days (OR 2.0), ESR > 40 mm/hr (OR 1.9), and levels of alpha-2 globulin > 7.5 g/L (OR 6.8) were statistically significant independent variables associated with the presence of focal forms. Twenty-five patients with complications (14.8%) required surgical treatment. The relapse rate was 3.6% for those patients without complications and 4.1% for patients with focal forms (p > 0.05). However, when therapeutic failure, relapses, and mortality were considered together, the risk of an unfavorable evolution was significantly greater in patients with focal forms (10.6% versus 3.6% in patients without complications; OR 1.9, 95% CI 1.4-7.1, p < 0.005). Given the worse prognosis, knowledge and early diagnosis of the focal forms of B. melitensis infection is especially important.

Adolescent↗

PubMed1996

Elimination of meat, fish, and derived products from the Spanish-Mediterranean diet: effect on the plasma lipid profile.

UNLABELLED: The effect of eliminating all animal (meat and fish) products except eggs and milk products from the current Spanish-Mediterranean diet was studied in 14 healthy subjects. This dietary manipulation decreased saturated and monounsaturated fat, protein, and cholesterol intakes. During the 2-month intervention period, a decrease in total plasma cholesterol concentrations (4.53 +/- 0.13 vs. 4.29 +/- 0.13 mmol/l, p < 0.05) was observed, mostly as a result of decreased high-density lipoprotein cholesterol levels (1.66 +/- 0.08 vs. 1.47 +/- 0.08 mmol/l, p < 0.05). The decrease in low-density lipoprotein cholesterol levels (2.51 +/- 0.15 vs. 2.43 +/- 0.13 mmol/l) did not reach statistical significance. Nevertheless, there was a significant association between the decrease in cholesterol intake and the decrease in low-density lipoprotein cholesterol levels (r = 0.719, p < 0.01). The decrease in protein intake was also correlated with the decrease in total cholesterol levels (r = 0.629, p < 0.05). Body weight and lean body mass were not modified during the study. Maximal aerobic power and maximal oxygen consumption were not significantly affected by the diet manipulation. IN CONCLUSION: a 2-month change from the current Spanish-Mediterranean diet to an ovolactovegetarian diet in young healthy persons decreases total plasma cholesterol levels, but mainly due to a decrease in high-density lipoprotein cholesterol levels.

Adult↗

PubMed1996

Carbamazepine trial for Lesch-Nyhan self-mutilation.

Anticonvulsants may reduce the self-mutilation of acquired sensory neuropathy, and one report described sensory neuropathy in an older patient with Lesch-Nyhan syndrome. We performed nerve and muscle biopsies on four patients with Lesch-Nyhan syndrome and initiated an uncontrolled pilot trial to see if carbamazepine would reduce the self-mutilation in these patients. All of the boys had clinical features typical of Lesch-Nyhan syndrome, and the diagnosis was confirmed in each by enzyme analysis. No specific abnormalities were identified in either nerve or muscle. Nevertheless, self-mutilation and the need for constant restraint diminished in all four patients, though in one the effect was only transient. Two patients had increased self-mutilation when carbamazepine was stopped, then improved a second time when treatment was restarted. Sensory neuropathy was not confirmed, so any effect of carbamazepine is likely to be on the central nervous system.

Adolescent↗

PubMed1996

Adjuvant treatment of node-positive breast cancer with cyclophosphamide, doxorubicin, fluorouracil, and vincristine versus cyclophosphamide, methotrexate, and fluorouracil: final report after a 16-year median follow-up duration.

PURPOSE: To determine the long-term impact on disease-free survival (DFS) and overall survival (OS) of adjuvant anthracycline-based chemotherapy, when prospectively compared by random allocation with standard cyclophosphamide, methotrexate, and fluorouracil (CMF) in node-positive (N+) breast cancer patients. PATIENTS AND METHODS: Two hundred forty-nine patients with N+ breast cancer, recruited from eight French cancer centers, were randomized to receive 12 monthly cycles of adjuvant chemotherapy, either CMF (n = 112) or doxorubicin, vincristine, cyclophosphamide, and fluorouracil (AVCF) (n = 136). All had a negative metastatic work-up before inclusion, which was stratified by accrual center, tumor stage (International Union Against Cancer [UICC]), and menopausal status. RESULTS: No severe adverse effect related to grade 4 (World Health Organization [WHO]) toxicity was observed. There was no difference in second primary tumor incidence between the two arms. The treatment given was 88% of planned for AVCF and 75% for CMF in both premenopausal and menopausal patients. With a median follow-up time of 16 years (range, 13 to 17), the OS and DFS rates are significantly longer in the AVCF arm (56% v 41% [P = .01] for OS, and 53% v 36% [P = .006] for DFS). These differences are significant, irrespective of tumor stage (T1 to T2 v T3 to T4), and remain positive in patients with or without postoperative locoregional radiotherapy (55% of cohort). When analyzed according to menopausal status, the differences remain significant only for premenopausal patients. CONCLUSION: This set of mature controlled data confirms the added value of anthracycline-based combination adjuvant therapy for N+ breast cancer patients when compared with CMF, with both regimens given for 1 year.

Adult↗

PubMed1996

Puerto Rican elders and botanical shops: a community resource or liability?

Puerto Rican elders face tremendous challenges in having their health and social service needs met in the United States. Service delivery to this population requires innovative approaches for involving the community. The use of botanical shops (culture versions of pharmacies) in collaborative activities offers much potential for the profession of social work and the field of human services. This article will report on a literature review and the results of a key informant survey of leading scholars on the topic of botanical shops; recommendations for the use of this community resource will be presented.

Aged↗

PubMed1996

[The use of SPECT with 201Tl in the evaluation of brain tumors].

There is increasing interest in the literature regarding the use of SPECT (single photon emission computed tomography) with 201Tl in the evaluation of cerebral tumours. Thallium (201Tl) is one of the isotopes most commonly used in studies of the myocardium and in the diagnosis of various tumours. Normal brain takes up very little 201Tl, but in viable tumour tissue the 201Tl becomes intracellular and is rapidly cleared from the blood stream. Such cerebral tumour uptake is related to changes in the permeability of the blood-brain barrier, regional blood flow and transport by means of the Na(+)-K+ adenosine triphosphate pump. Once the SPECT images have been obtained following administration of the radioisotope, one can calculate the indices of early and of late uptake together with the retention index. The usefulness of SPECT in the preoperative detection of malignant expansive pathology, choice of tumour region during stereotaxic biopsy, control of tumour reproduction and their differentiation from post-radiotherapy necrotic tissue, and evaluation of chemotherapy in treatment of cerebral tumours are analyzed. Finally the application of SPECT in metastatic conditions and the differential diagnosis of expansive lesions is considered.

Blood-Brain Barrier↗

PubMed1996

[Familial transmission of hepatitis C virus].

OBJECTIVE: To establish the prevalence of antibodies to hepatitis C virus (HCV) among relatives and other persons cohabiting with HCV carriers, as an indication of the risk of intradomestic transmission. EXPERIMENTAL DESIGN: A transversal study of series of clinical cases. A questionnaire was applied to the index cases (IC) and contact cases (CC), differentiating sexual contacts (SC) from non sexual contacts (NSC). PATIENTS: One hundred and sixty four IC and 533 CC were included. Information on parenteral risk factors, type of sexual relationship, period of exposure, and other epidemiological variables was obtained. Antibodies to HCV (HCV-Ab) were determined by 2nd generation ELISA. RESULTS: In eighty eight IC (53.6%) no parenteral risk factors were found. In 99 IC (62.8%) a liver biopsy showed chronic hepatitis or cirrhosis. Twelve CC (2.25%) turned out to be HCV-Ab (+), a ratio above that found in our city (0.3%, p < 0.001), however the comparison should be taken with caution. No significant differences were found with respect to several epidemiological variables, including type of sexual relationship, and socioeconomic indicators, between CC HCV-Ab (+) and (-). Stage of liver disease in the IC and relationship between IC and CC did not increase the risk of being HCV-Ab positive. In HCVAb positive CC a higher proportion of parenteral risk factors (p < 0.001), elevated ALT (p < 0.001) and sharing of personal tools (p < 0.01) were observed. CONCLUSIONS: Intrafamiliar transmission of HCV is poorly documented and it is related to the presence of parenteral risk factors. The actual prevalence of HCVAb in a general population is unknown, rendering difficult to make definite conclusions.

Adolescent↗

PubMed1995

The influence of B chromosomes on rDNA organization in rye interphase nuclei.

Patterns of rye rDNA organization in interphase nuclei were studied through the use of in situ hybridization in spreads of root meristem cells from plants with and without B chromosomes (Bs). In cells from plants without Bs each rDNA locus is organized as a single perinucleolar knob of condensed chromatin with decondensed chromatin inside the nucleolus. In plants with Bs there is a marked modification of the pattern, found in more than 23% of nuclei, which involves several regions of condensed chromatin interspersed with decondensed chromatin inside the nucleolus. This B-induced alteration in rDNA interphase organization suggests a change in expression of the rRNA genes located on the A chromosomes probably related to the reduction in nuclear RNA observed previously in plants with Bs. The influence of the Bs on the expression of A chromosome genes, through rearrangement of interphase chromatin, could provide the basis of an explanation for some of the known phenotypic effects of B chromosomes in rye.

Cell Nucleus↗

PubMed1995

Pituitary adenylate cyclase-activating polypeptides (PACAP27 and PACAP38) inhibit the mobility of murine thymocytes and splenic lymphocytes: comparison with VIP and implication of cAMP.

In the present study, the effects of PACAP27, PACAP38 and VIP in a concentration range from 10(-13) to 10(-6) M were studied in vitro on the spontaneous and directed mobility of lymphocytes from rat spleen and thymus. The results show that VIP and both PACAPs inhibit significantly and in a similar way the mobility of lymphocytes from thymus and spleen, and the maximal effects were observed at 10(-9) M and 10(-8) M. The three neuropeptides significantly increased cAMP concentrations. Moreover, incubation with increasing PMA concentrations showed a progressive enhancement of chemotaxis of lymphocytes, which was partially prevented by VIP, and both PACAPs. Incubation with forskolin caused decrease in the chemotaxis of thymocytes and splenocytes, and the presence of VIP or PACAP peptides was not synergistic in the inhibitory effect on lymphocyte chemotaxis, suggesting that the three neuropeptides and forskolin mediate their actions by the same intracellular pathway. This study showed the ability of the VIP receptor antagonist (N-Ac-Tyr1,D-Phe2)-GRF(1-29)-NH2 to partially reverse the inhibitory effect of both PACAPs and VIP on chemotaxis, suggesting that PACAP receptors are identical or very similar to VIP receptors in both thymocytes and splenocytes. These data suggest that PACAP27 and PACAP38 can be included as two novel immunoregulatory peptides that can modulate cell mobility on central and peripheral lymphoid organs.

Animals↗

PubMed1994

Gene expression of VIP receptor in rat lymphocytes.

In the present report we analyze by reverse transcription (RT) and polymerase chain reaction (PCR) the expression of vasoactive intestinal peptide receptors (VIP-R) in rat thymocytes and peripheral T and B lymphocytes. We have obtained a specific VIP-R cDNA product of 311 bp identical in size to that obtained from lung. These results have been confirmed by Southern hybridization analysis. VIP receptor gene expression in central and peripheral lymphoid organs support the notion that VIP is a immunomodulatory peptide.

Adjuvants, Immunologic↗

PubMed1994

Vasoactive intestinal peptide (VIP) mRNA expression in rat T and B lymphocytes.

Different evidence suggests that VIP has immunoregulatory functions and may be secreted by different cells involved in inflammatory and immune responses. In the present study, we demonstrate by reverse transcription (RT) and polymerase chain reaction (PCR) VIP gene expression in rat thymocytes and T and B cells derived from spleen and lymph nodes. We have obtained a specific VIP cDNA product of 458 bp identical in size to that obtained from cerebral cortex. These results have been confirmed by Southern blot analysis. VIP message has also been detected in the T-T hybridoma YH-1633 and in a non-immune cell line, the pheochromocytoma PC 12. VIP gene expression in central and peripheral lymphoid organs suggests that VIP may be a T and B cell-derived cytokine involved in T-cell differentiation and in cell immune responses.

Animals↗

PubMed1994

Lymphoid cell subpopulations containing vasoactive intestinal peptide in the rat.

In the present study we describe the cell types containing immunoreactive vasoactive intestinal peptide (IR-VIP) in rat thymus, spleen, and lymph nodes. Indirect immunofluorescence staining and flow cytometry indicated that all lymphoid organs studied contained VIP-positive cells, with the spleen and lymph nodes having a higher proportion than the thymus. Vasoactive intestinal peptide was found in both lymphocytes and nonlymphoid cells, lymphocytes predominating among VIP-positive cells. Double immunofluorescent staining and flow cytometry showed that all lymphoid subpopulations identified contained variable proportions of VIP-positive lymphocytes. Immunocytochemical staining of cell suspensions for both light and electron microscopy showed the cytoplasmic localization of the IR-VIP. These findings, coupled to our previous results, are consistent with the idea that VIP may have a lymphoid origin and could be active in local immune responses.

Animals↗