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Biomedical subjects

R Ramirez

Publications and source records attributed to R Ramirez.

At least 91 records · Page 5Linked to original sources
PubMed1984

The effect of 16, 16-dimethyl prostaglandin E2 on experimental bile reflux pancreatitis in the opossum.

Pharmacological attempts to alter the course of experimental pancreatitis in the opossum were made using synthetic 16, 16-dimethyl prostaglandin E2 (16, 16-dm PGE2). Anatomically, the opossum has an elongated ampulla resulting in a supraduodenal pancreatic duct-common bile duct junction allowing for bile reflux pancreatitis to be produced by ligating the distal common bile duct. Preliminary evaluation demonstrated that at 72 hours common bile duct ligation distal to the pancreatic duct orifice produced pancreatitis comparable in severity to that produced by a Pfeffer loop. When the oppossum distal common bile duct was ligated, serum amylase concentrations progressively increased from control values of 182 +/- 43 to 742 +/- 62 Somogyi units/dl at 5 hours. Administration of 0.2 microgram-kg-1-min-1 16, 16-dm PGE2 significantly decreased the hyperamylasemia associated with bile reflux pancreatitis and, in addition, decreased the pancreatic gland weights when compared to control values. Subsequent evaluation of the administration of 75 micrograms-kg-1 16, 16-dm PGE2 every 12 hours for 72 hours to opossums with distal common bile duct ligation demonstrated no significant differences in serum amylase concentrations when compared to control values. Histologic evaluation of the pancreas glands at 72 hours demonstrated increased glandular integrity when the pancreas glands from the opossums receiving 16,16-dm PGE2 were compared to the glands subjected to distal common bile duct ligation alone. This report identifies several favorable characteristics in the course of experimental pancreatitis associated with the administration of a synthesis PGE analog at the onset of the inflammatory process.(ABSTRACT TRUNCATED AT 250 WORDS)

16,16-Dimethylprostaglandin E2↗
PubMed1981

Interaction of vasoactive intestinal peptide with human blood mononuclear cells.

The binding of vasoactive intestinal peptide (VIP) and the stimulation of adenylate cyclase were studied in mononuclear cells from human peripheral blood. The binding depended on time, temperature and pH, and was reversible, saturable and specific. Binding studies suggested the presence of 2 classes of binding site: a class with high affinity (Kd = 2.4 X 10(-10)M) and low capacity (8 fmoles/10(6) cells), and a class with low affinity (Kd = 8.0 X 10(-8)M) and high capacity (800 fmoles/10(6) cells) at 15 degrees C. Secretin displaced [125I]VIP from the cells with a 400-fold lower affinity than VIP, but glucagon, somatostatin and insulin did not show any effect. VIP was a potent and efficient stimulator of cyclic AMP production. The stimulation was observed at a concentration as low as 3 X 10(-11)M and depended on time, temperature and pH. Maximal cyclic AMP production (4-fold above basal levels) was observed with 10(-9) M at 15 degrees. Half-maximal response was obtained at 10(-10)M VIP. Secretin was an agonist of VIP but exhibited a 7000 times lower potency. Peripheral blood mononuclear cells constitute an easily accessible and suitable system for the study of VIP action in different physiological and pathophysiological conditions.

Adenylyl Cyclases↗
PubMed1981

Gray scale ultrasonography and transhepatic cholangiography in evaluation of obstructive jaundice: a comparative study.

A total of forty-four jaundiced patients were studied by one or both diagnostic modalities (Gray Scale Ultrasonography or Transhepatic Cholangiography--THC--). The thin needle transhepatic cholangiography permitted in vivo correlation of the ultrasonographic findings. Patients with obstruction were confirmed by surgery. Many of the non-obstructive cases underwent liver biopsy. The accuracy of Gray Scale Ultrasonography in differentiation of surgical from medical jaundice dependent on the serum bilirubin level at the time of the examination. For serum bilirubin levels of seven or more milligrams percent, the accuracy was almost one hundred percent. For serum bibiribuin levels of less than seven milligrams percent, the accuracy was approximately eighty-three percent. THC using the thin needle is the ultimate diagnostic procedure and complements the ultrasound information, especially in cases with minimal to moderate icterus. A proposed flow chart for evaluation of the jaundiced patient is presented. The ability to determine the presence of obstruction by demonstrating dilated bile ducts at different levels of serum bilirubin with Gray Scale Ultrasonography was evaluated. Percutaneous TCH using the thin needle (Chiba Needle) made possible the in-vivo correlation of many of the ultrasound findings, as well as the demonstration of surgical jaundice in patients with normal sized bile ducts.

Bilirubin↗
PubMed1980

Correlates and changes over time in drug and alcohol use within a barrio population.

Extent and determinants of use of alcohol, marijuana, inhalants, and PCP were explored in a group of 339 Mexican American youths from the East Los Angeles Housing projects. Results from this study were compared to those from a similar survey carried out in the same area 2 years ago. Use of inhalants has declined markedly compared with prevalence reported in the previous report. However, use of alcohol and marijuana have increased across all age and sex cohorts. Prevalence of PCP use, explored for the first time in this report, was shown to be extremely high. Use of all drugs was generally predicted by age, sex, and number of peers reporting use. Self-concept factors, especially one's self-evaluation with respect to others, were also significant predictors to use of marijuana, inhalants, and PCP. However, alcohol use was not related to any self-concept factors. Language (Spanish-English) used both in the home and with peers was related to use of all substances studied. Limitations in the generalization of this study as a result of sampling problems are discussed.

Adolescent↗
PubMed1980

Evaluation of alternative pathway and factor B haemolytic activities in patients with systemic lupus erythematosus: correlations with the alternative pathway regulatory proteins.

The haemolytic activities of the complement alternative pathway and factor B were studied using a 51Cr-release assay in 77 sera from patients with systemic lupus erythematosus (SLE). These values were compared to those of several complement components and of the regulatory proteins beta H and C3b INA. There was a significant decrease in the alternative pathway activity, which correlated with a decrease in the haemolytic activity of factor B and with the activity of the classical pathway. There was a significant decrease in the level of one regulatory protein beta 1H, while the level of the other regulatory protein, C3b INA, was increased; however, there was a positive correlation between these two parameters. The results obtained suggest that the decreased activity of the alternative pathway observed in SLE reflects a consumption due to a triggering of the C3b amplification loop through the activation of the classical pathway. In one patient, an acquired deficiency of the capacity to activate the alternative pathway in the presence of inulin was observed.

Adult↗
PubMed1979

[Surgical therapy of intestinal complications in abdominal typhus].

At our clinic 185 patients with severe typhoid fever were treated. In 51 cases severe complications required a surgical therapy: 24 times bleeding of small or large intestine, 14 times perforation of the bowel and 13 times acute typhoid cholecystitis. Lethality of typhoid peritonitis with perforation is nowadays--inspite of specific therapy with antibiotics--still between 40% and 50%; lethality at our clinic was 37.5%. Dangerous complications are bleeding and re-perforation, which require an aggressive surgical procedure.

Chloramphenicol↗
PubMed1979

Inhalant, marijuana, and alcohol abuse among barrio children and adolescents.

Prevalence of inhalant, marijuana, and alcohol abuse was studied in a sample of 457 male and female Mexican-American children and adolescents between the ages of 9 and 17 years. Subjects interviewed resided in four housing projects located in East Los Angeles. All interviews were conducted by adolescents who resided in the same housing projects. Results indicated that compared to a national sample, Mexican-American adolescents were at least 14 times more likely to be currently abusing inhalants. The prevalence rate of marijuana was double the national rate, but the prevalence of alcohol was equal to that found nationally. Reasons for elevated substance abuse rates are explored.

Adolescent↗
PubMed1976

Mycotic flora in the lower digestive tract of feral pigeons (Columba livia) in the El Paso, Texas area.

Fourteen species of fungus were isolated from the lower digestive tract of 39 of 80 pigeons. Sixteen pigeons had concurrent isolations while two harbored three species. Fungi isolated were Allescheria boydii, Aspergillus spp., Candida krusei, Chrysosporium spp., Geotrichum candidum, Mucor spp., Paeciliomyces spp., Penicillium spp., Rhizopus spp., Rhodotorula spp., Scopulariopsis spp., Streptomyces spp., and Trichosporon cutaneum. There was no apparent evidence that these fungi were associated with clinical disease in any of the pigeons.

Animals↗