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M Rodriguez

Publications and source records attributed to M Rodriguez.

747 records · Page 42Linked to original sources
PubMedDate not supplied

[Structure-activity relationship of cystokinins: analogs exhibiting selective activity].

Structure-activity relationship on cholecystokinin is presented. C-terminal heptapeptide analogues of cholecystokinin exhibiting selective agonist or antagonist activities were synthesized and their biological and pharmacological properties studied. We showed that: 1) Suppression of the C-terminal phenylalanine residue leads to peripheral as well as central cholecystokinin receptor antagonists; 2) Suppression of the C-terminal amide function produces "partial agonists" exhibiting interesting biological and pharmacological activities; 3) Replacement of L-tryptophan residue by D-tryptophan in such "partial agonist analogues" resulted in potent CCK receptor antagonists; 4) The peptide bond between methionine28 and glycine29, as well as the glycine residue are quite significant for the central biological activity; 5) It is possible to obtain highly potent and selective CCK analogues for the central receptor (CCK-B) by cyclization including the C-terminal tetrapeptide. Synthesis and pharmacological studies with these analogues have allowed to precise the significance of some amino acid residues as well as of some peptide bonds. They are significant pharmacological tools for the study of CCK-A (peripheral) and CCK-B (central) receptors, their biological actions and their associated intracellular messengers.

Amino Acid Sequence↗
PubMedDate not supplied

Influences of the microenvironment on B-cell responses of wasted mice: comparison of Peyer's patches and mesenteric lymph nodes.

Wasted mice bear an autosomal recessive mutation (wst/wst) that gives rise to neurologic abnormalities and immunologic deficiency evident as early as 21 days of age. Features of the immune deficiency include absence of plasma cells at mucosal sites, reduction in weight of thymus and spleen relative to body weight, and low serum levels of some immunoglobulin (Ig) isotypes. In these experiments, we have examined parameters of B-cell function in Peyer's patches (PP) and mesenteric lymph nodes (MLN) of wst/wst and age-matched control mice. Our results established the following abnormalities in PP but not MLN of wst/wst mice relative to controls: (1) reduced mitogenic responses to lipopolysaccharide, (2) decreased percentages of Ig+ cells, (3) increased percentages of B-cells bearing large amounts of surface Ig ("very bright" Ig+ cells), and (4) reduced levels of all Ig-specific messenger ribonucleic acids (mRNAs) except alpha-mRNA. The only immunologic abnormality consistently expressed in lymphocytes from both MLN and PP of wst/wst mice is reduced levels of IgA+ B cells and alpha-mRNA. Morphologic studies revealed no consistent abnormalities in lymph nodes, spleens, livers, or PP of wst/wst mice when compared to littermate controls. These results support the idea that some of the immunologic abnormalities reported in wst/wst mice are due to microenvironmental influences. Of the parameters examined in this report, only reduced IgA (mRNA levels and percentage of positive cells) is consistently observed in PP, MLN, and spleen.

Animals↗
PubMedDate not supplied

Conditioning the placebo response in the rotational model of Parkinson's disease.

Persistent behavioural effect of the direct dopamine receptors agonist apomorphine in the rotational model of Parkinson's disease was investigated. We show how this placebo response can be considered an extraordinary example of environment-drug associative learning and how it can be related to a critical point of the time-course response to the drug after repeated administration. Classical conditioning of "placebo response" in an animal model of a neurological or psychiatric disease had not been reported previously.

Animals↗
PubMedDate not supplied

[Cardiovascular effects of elliptinium. The mechanism of action].

The effects of elliptinium were studied: Firstly, in the dog, in comparison with the effects of histamine, on heart rate and arterial blood pressure. Secondly, in guinea-pig isolated atria. When smaller doses were used (0.375; 0.75; 1.5 mg/kg) elliptinium only induced variations of heart rate. With the dose of 3 mg/kg hypotension and tachycardia appeared. The time-course of these effects was different from that of histamine (5 micrograms/kg): later onset and longer duration. Elliptinium was inactive in isolated guinea-pig atria, as observed in tracheal or digestive isolated smooth muscle. Thus, the cardiovascular activity of this antitumoral agent seems to implicate an indirect mechanism of action. This result is in accordance with the previous results obtained on bronchopulmonary system.

Alkaloids↗
PubMedDate not supplied

[Anorectal manometry. Experience of 5 years].

Anorectal manometry is a non invasive, safe and useful procedure for exploring anorectal function in several disease. The anorectal studies made in our service the last five years in children, were reviewed. There were made 234 procedures in patients 21 year old or less 93.25% of the studies could be finished and 72.64% of the patients were from other hospitals or centers. The age average was 5.62 +/- 4.72 years and the main indication was constipation (78.20%). We didn't find any statistical difference in the manometrical findings of the internal anal sphincter between the patients with only constipation, only encopresis, constipation plus encopresis and normal values. The main manometrical diagnostic in the constipated patient without Hirschsprung disease was "Normal Study" even though between 30 and 55% of the studies showed "inspecific motor dysfunction". The patients with anorectal malformations had a main internal and pressure statistically lower (Z = 3.29 p = 0.03) and "Non concluyent Study" percentage higher (Z03.44 p = 0.02) than the constipated ones. The main external anal pressure was not different between groups. In 43 patients the manometrical study showed "Suggestive of Hirschsprung Disease". We recovered the histological reports in 55.88% with aganglionosis in the 91.66%. There were no statistical differences in the other manometrical parameters. Our finding agree with the ones reported in the specialized literature and support the anorectal manometry as an useful tool for exploring the anal sphincter integrity in anorectal malformations.

Adolescent↗
PubMedDate not supplied

[Etiology and epidemiology of 547 episodes of acute viral hepatitis diagnosed in adults in a general hospital (1983-1994)].

The etiology and epidemiology of 547 consecutive episodes of acute viral hepatitis in adults and diagnosed in a general hospital over 12 years (1983-1994) were prospectively analyzed as were the changes observed during the two halves of the study period. Of the 547 episodes, 25.4% were of type A, 41.1% type B, 21.9% type C, 6.6% non A, non B, non C, 2.4% type D, 1.1% by cytomegalovirus and 1.4% by the Epstein-Barr virus. The proportion of hepatitis A increased from 21.5% from 1983-1988 to 34.1% from 1989-1994 (p = 0.002), while hepatitis C decreased from 24.9% to 15.3% (p = 0.01) during the same periods. The proportion of hepatitis B observed in intravenous drug addicts fell from 56.1% in the first period to 39.3% in the second period (p = 0.03), while sexually transmitted hepatitis B rose from 7.3% to 22.9% (p = 0.002). A decrease was observed in the cases of hepatitis C in both periods in the intravenous drug addict cases (60.6% vs. 34.6%; p = 0.03) with an increase being observed in the C virus transmitted by unapparent mechanisms (2.1% vs. 23.1%; p = 0.001). These results suggest that modifications may currently be observed in the epidemiology of the viral hepatitis in Spain and that these trends should be taken into account when planning preventive strategies.

Adolescent↗