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Biomedical subjects

J Arias

Publications and source records attributed to J Arias.

At least 109 records · Page 6Linked to original sources
PubMed1989

Light- and electron-microscopical localization of calcitonin, calcitonin gene-related peptide, somatostatin and C-terminal gastrin/cholecystokinin immunoreactivities in rat thyroid.

Parafollicular C cells of the rat thyroid contain several immunoreactive peptides including calcitonin (CT), calcitonin gene-related peptide (CGRP), somatostatin and a C-terminal gastrin/CCK immunoreactive epitope as shown at the light- and electron-microscopical levels. Adult thyroid C cells are strongly immunoreactive to CT and most of the cells also react strongly with CGRP antisera and weakly with a gastrin/CCK antiserum. The latter antiserum may cross-react with CGRP. This cross-reactivity probably only occurs at very high concentrations of CGRP observed in adult thyroid C cells, but not in intrathyroidal CGRP-containing nerves, nor in early neonatal C cells. In neonatal rats, somatostatin immunoreactive C cells are numerous and most of these cells are also CT and CGRP immunoreactive. In contrast, only few C cells display somatostatin immunoreactivity in adult rat thyroids. Sequential staining experiments revealed that some thyroidal C cells simultaneously express all four types of immunoreactivity. At the electron microscopical level, all of these immunoreactivities were observed in secretory granules of C cells. Double- and triple-staining experiments, moreover, documented that some peptides are co-localized in the same granules.

Animals↗
PubMed1989

[Benign hemophagocytic syndrome. First confirmed case in Panama].

The authors present the clinical history of the first case of benign hemophagocytic syndrome diagnosed in Panama. The patient, a 4 year old girl, presented with fever, anemia, cervical lymphadenitis, hepatomegaly, lymphocytosis and histophagocytosis of red cells, lymphocytes, neutrophils and platelets. Spontaneous remission of the fever occurred sixty days after the onset of the disease. Although it was not possible to demonstrate serologically that the syndrome was due to acute toxoplasmosis, she was treated with sulfadiazine and pyrimethamine for fifteen days, on the 37th hospital day, and with clindamycin for ten days, consecutively. Remission occurred seventy days after the onset of fever. A second serological examination for toxoplasmosis (immunofluorescent antibodies) was positive in a titer of 1:2048 again, nine months after the first serology.

Child, Preschool↗
PubMed1989

[Immunosuppression with cyclosporin after orthoptic liver transplant in pigs].

The immunosuppressive effect of cyclosporine A (CsA) was studied in six pigs that underwent orthotopic liver transplant (OLT). The drug was administered i.v. in low doses (1.5-4 mg/Kg-1/12 h-1) and associated with wide spectrum antibiotics. The mean survival of the animals was 23.4 +/- 11.2 days. All animals had fever, jaundice and hypertrichosis, and the preoperative corporal weight remained constant. Liver abscesses by E. coli were common autopsy findings. Livers also presented biliary regeneration and cholestasis with a slight lymphocytic infiltration. OLT in pigs without immunosuppressive treatment causes and elevation in serum gamma-GTP, GOT, LDH, alkaline phosphatase and bilirubin. In the post-mortem findings, the livers did not present abscesses but evidenced intense atrophy with hepatocellular necrosis and abundant lymphocytic infiltration.

Animals↗
PubMed1988

Monoclonal antibodies against calcitonin. Characterization and application in light and electron microscopy immunocytochemistry.

Twenty-seven monoclonal antibodies (MAbs) to synthetic human calcitonin (CT) were characterized for their reactivities with human CT peptide fragments by dot-blot analysis on nitrocellulose paper. Most of the antibodies bound to the C-terminus and fewer to the mid-region of CT. We have studied thyroid tissue specimens from several animal species after fixation in paraformaldehyde-, glutaraldehyde- or picric acid-containing mixtures and cryostat sectioning or embedment in paraffin or plastic (Epon 812 or Lowicryl 4KM) using this panel of MAbs. The site of antigen-antibody reaction was revealed either by immunoperoxidase, immunoalkaline phosphatase or by silver-enhanced immunogold staining methods. All MAbs were able to localize CT in human, rat and mouse thyroid C cells. Nineteen MAbs recognizing synthetic salmon CT and synthetic [Asu1,7]-eel CT by dot-blot, reacted with chicken ultimobranchial body C cells. One MAb recognizing native porcine CT by dot-blot, stained C cells in hog thyroid. Immunopositivity was confined to the cytoplasm and ultrastructural immunogold labelling demonstrated that cytoplasmic secretory granules were stained. Surgical specimens from human medullary thyroid carcinoma were also analysed for the presence of CT and a variable number of positive cells was found. Furthermore, Congo red-positive areas were shown to react with the MAbs. All conventional staining and immunoabsorption controls were negative. Hence, these MAbs may be suitable for use in routine immunopathological diagnosis of CT-producing tumors and for immunocytochemical localization of the three major CT variants in different animal species.

Animals↗
PubMed1988

[Effect of the incorporation of additives on the aging of corn starch gels and "arepas"].

This research was carried out to investigate the effect of the incorporation of various additives on the ageing of corn starch and arepas. Starches were extracted from the endosperm of degerminated corn by a wet milling process, and its retrogradation, with or without the incorporation of additives was evaluated using the Brabender amilograph and by measuring the viscosity changes of the starch gels through time, using a Brookfield viscometer model RVT. The most effective additives in retarding the rate of ageing of starch gels, were used in the arepas. Likewise, trained panelists were utilized to find the levels of the additives incorporated in the arepas, by running taste threshold tests for each one of the additives. Textural changes of the arepas--maintained at two different storage temperatures, 9 degrees and 23 degrees C--were evaluated using an Instron texturometer. Preliminary tests with the corn starch allowed to choose the following additives: distilled monoglicerides, guar gum and hydrogenated vegetable oil. The effect of 15 different combinations of these additives on the texture of arepas was then studied, and findings revealed that only three of them were able to totally revert the retrogradation process, and maintain the hardness and elasticity within the expected range of a fresh-made arepa, when this is reheated until reaching a maximum temperature of 49 degrees C. A 66% of the hardening of the arepas prepared without additives can be reverted with the reheating process, but only if the product has not suffered dehydration. When stored for 24 hours at room temperature, unpacked arepas have a surface moisture loss of 47%, and even if reheated, hardening becomes irreversible in 84.6% of them.

Food Additives↗
PubMed1988

Long esophagoplasty: functional study.

The functional results of different types of plasty were evaluated in 46 patients who had undergone esophageal replacement for different pathologies. The patients were classified into three groups according to the type of plasty: I) 19 ileocecocolonoplasties (ICC), II) 11 left colonoplasties (LC), III) 16 gastroplasties (GP). The postoperative studies made were: a) clinical evaluation, b) radiological barium contrast study, c) isotopic transit of semisolid food marked with 99m-Tc colloidal sulfur and d) manometry. The clinical evaluation disclosed no significant differences between the three groups. Isotopic scans revealed more rapid emptying of the ICC, with elimination by the ileal segment in the first minute of 76.3 +/- 3.3% of the isotope, and by the entire plasty of 79.4 +/- 4.2% in 15 minutes (p less than 0.001). The manometric study showed non-response by the GP. The motor activity of the terminal ileoplasty was greater than that of the other plasties studied, and that of the right colonoplasty was greater than that of the left (p less than 0.01). Likewise, the clearance of acid (HCl 0.1N) by the ICC was more rapid than that of the LC (p less than 0.01). It is concluded that, functionally, the ICC is a better long esophagoplasty than the other procedures studied.

Adult↗
PubMed1986

Somatostatin in the treatment of severe upper gastrointestinal bleeding: a multicentre controlled trial.

To evaluate the effectiveness of somatostatin versus combined cimetidine and pirenzepine in the treatment of upper gastrointestinal (GI) bleeding of peptic origin, a multicentre controlled, prospective, randomized and double blind trial has been undertaken in 60 subjects. Strict selection criteria were followed. All subjects were diagnosed by endoscopy during the first 18 h after admission. Endoscopic stigmata of recent haemorrhage were also evaluated. Sixty-five per cent of the subjects presented with severe upper GI bleeding (blood pressure less than or equal to 100 mmHg, pulse rate greater than or equal to 110, haematocrit less than or equal to 30 per cent), and in 71.6 per cent stigmata were found. Thirty patients (Group 1) received a somatostatin infusion (250 micrograms/h continuously during 120 h) and 30 patients (Group 2) received cimetidine (200 mg IV every 4 h for 5 days) and pirenzepine (10 mg IV every 8 h for 5 days). Both groups were homogeneous for sex, age, backgrounds, bleeding source, grade of bleeding (moderate or severe) and presence or not of stigmata. Bleeding stopped in 27 subjects of Group 1 (90 per cent and in 20 subjects of Group 2 (66.67 per cent) (P less than 0.05, chi 2 test). The time until the bleeding stopped was significantly shorter in patients of group 1 (3.44 +/- 0.53 h) than in patients of group 2 (8.12 +/- 1.94 h) (P less than 0.05, Mann-Whitney U test). The number of blood units required for Group 1 (2.26 +/- 0.35) was significantly lower than the one required for Group 2 (3.90 +/- 0.51) (P less than 0.005, Wilcoxon test). Significant differences were not observed between the two groups regarding cross-over subjects, re-bleeding, surgery (P = 0.0635, Fisher's exact test) and hospital stay. The mortality of the trial was 5 per cent. There was no toxicity during somatostatin, cimetidine or pirenzepine infusion. In conclusion, somatostatin was more effective than cimetidine plus pirenzepine in the control of severe upper GI bleeding of peptic origin, with a lower interval time to stop bleeding and reduced transfusion requirements.

Cimetidine↗