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Biomedical subjects

R Arellano

Publications and source records attributed to R Arellano.

13 recordsLinked to original sources
PubMed1996

Epidural morphine vs hydromorphone in post-caesarean section patients.

PURPOSE: The purpose of this randomized controlled double blind study was to compare the efficacy of pain relief and the side effects of epidural hydromorphone and morphine in post-Caesarean patients. METHODS: In all patients, epidural anaesthesia was induced using carbonated lidocaine 2% with 1:200,000 epinephrine and 50 micrograms fentanyl, given in incremental doses. Patients in Group 1 (n = 24) received 0.6 mg hydromorphone and patients in Group 2 (n = 22) received 3 mg morphine after delivery of the infant. Pain, pruritus and nausea were measured using a visual analog scale (at times: baseline, on admission to the recovery room, 3, 6, 12, 18 and 24 hr postoperatively), by the number of requests for additional medications and by an overall satisfaction score. RESULTS: There was no difference between the groups in pain relief of in the incidence and severity of side effects. Pruritus was more pronounced within the first six hours in Group 1 and at 18 hr in Group 2. CONCLUSION: Hydromorphone provides no clinical benefit over epidural morphine for post operative analgesia following Caesarean section.

Adult↗
PubMed1996

Tranexamic acid reduces blood loss, transfusion requirements, and coagulation factor use in primary orthotopic liver transplantation.

BACKGROUND: Patients with end-stage liver disease frequently incur large-volume blood loss during liver transplantation associated with mechanical factors, preexisting coagulopathy, and intraoperative fibrinolysis. METHODS: Between April 1992 and May 1994, the authors of this double-blind, randomized, placebo-controlled study examined the effect of high-dose tranexamic acid (maximum of 20 g) on blood loss and blood product requirements in patients undergoing primary isolated orthotopic liver transplantation. Primary outcome measures were volume of blood loss (intraoperative blood loss and postoperative drainage) and erythrocyte, plasma, platelet, and cryoprecipitate use during surgery and the first 24 h of intensive care unit stay. RESULTS: Patients receiving tranexamic acid (n = 25) had less intraoperative blood loss (median, 4.3 l; interquartile range, 2.5 to 7.9; P = 0.006) compared with the placebo group (n = 20; median, 8 l; interquartile range, 5 to 15.8), and reduced intraoperative plasma, platelet, and cryoprecipitate requirements. Median perioperative erythrocyte use was 9 units (interquantile range, 4 to 14 units) in patients receiving tranexamic acid and 13 units (interquantile range, 7.5 to 31 units) in controls (P = 0.03). Total perioperative donor exposure was 20.5 units (interquantile range, 16 to 41 units) in patients receiving tranexamic acid and 43.5 units (interquantile range, 29.5 to 79 units) in controls (P = 0.003). Results for postoperative wound drainage were similar. Hospital stay and need for retransplantation were comparable in both groups. No patient in either group showed clinical evidence of hepatic artery or portal venous thrombosis within 1 month of transplantation. CONCLUSIONS: High-dose tranexamic acid significantly reduces intraoperative blood loss and perioperative donor exposure in patients with end-stage parenchymal liver disease who are undergoing orthotopic liver transplantation, with marked reductions in platelet and cryoprecipitate requirements.

Adult↗
PubMed1993

Role of isoprenylation in intracellular pH regulation of granulocytes.

Lovastatin was used to study the role of isoprenylated GTP-binding proteins in the regulation of intracellular pH in granulocytic HL-60 cells. The cytosolic acidification that accompanies stimulation by chemoattractants was completely eliminated by lovastatin. The subsequent activation of Na+/H+ exchange was partially inhibited by the isoprenylation antagonist. In contrast, the osmotic activation of the Na+/H+ antiport was unaffected. The data indicate that the osmotically- and receptor-induced activation of the antiport utilize divergent signalling pathways. The results also provide evidence supporting the notion that cytosolic acidification by chemoattractants results from accumulation of metabolic acid generated during the respiratory burst.

GTP-Binding Proteins↗
PubMed1993

Glucocorticoid prevention of neonatal hypoxic-ischemic damage: role of hyperglycemia and antioxidant enzymes.

Recently, we observed that pre-treatment of neonatal rats with dexamethasone prevents brain damage associated with cerebral hypoxia-ischemia (unilateral carotid occlusion + 3 h hypoxia). Presently, we investigate whether hyperglycemia or an induction of endogenous free radical scavengers explains dexamethasone's neuroprotective effect. Pathological damage was examined in rats maintained hyperglycemic during hypoxia-ischemia by the repeated administration of 10% glucose (10 ml/kg, i.p.) at 0, 1, 2 and 3 h of hypoxia (n = 14) and this damage was compared to that in control (n = 15) or dexamethasone (0.1 mg/kg, i.p., n = 15) treated animals. Despite similar elevations in blood glucose at the end of hypoxia, glucose treated animals had greater damage than dexamethasone treated animals and both of these groups had less damage than controls (volumes of damage of approx. 30.9 +/- 10, 3.4 +/- 2.3 and 60.4 +/- 7.1% of the hemisphere, respectively; P < 0.0001). Anti-oxidant enzyme activities were measured within brains of animals treated with dexamethasone or vehicle (n = 44). Activities of the enzymes catalase, glutathione peroxidase and CuZn- or Mn-superoxide dismutase were similar in both treatment groups, with or without exposure to hypoxia-ischemia. Thus, an induction of antioxidant enzymes does not explain dexamethasone's effects whereas the relative hyperglycemia associated with glucocorticoid treatment may contribute partially. Neither account fully for dexamethasone's protective effect suggesting an additional glucocorticoid mediated mechanism must be involved.

Animals↗
PubMed1992

Prevalence of latex sensitization among hospital physicians occupationally exposed to latex gloves.

Patients undergoing surgery who have a history of occupational exposure to latex gloves may be predisposed to intraoperative anaphylaxis caused by latex allergy. Thus, medical personnel who routinely wear latex gloves may be at higher risk than the general population. The prevalence of latex sensitization has not been reported previously among physicians using latex gloves in a North American hospital setting. Using a latex skin prick test (SPT), we determined the prevalence of latex sensitization among 101 staff anesthesiologists, radiologists, and surgeons who regularly use latex gloves and among 100 atopic controls who were not occupationally exposed to latex gloves. Latex SPT was positive in 10 of 101 physicians (rho = 0.099; 95% confidence interval [CI] 0.041, 0.157) and 3 of 100 controls. Subgroup analysis showed that 9 of 38 atopic physicians were SPT-positive (rho = 0.237; 95% CI 0.102, 0.372). Atopic physicians were more likely to be latex SPT-positive than either nonatopic physicians or atopic controls (atopic vs. nonatopic physicians: P = 0.0006, odds ratio = 19.2, 95% CI 15.4, 23.1; atopic physicians vs. atopic controls: P = 0.0005, odds ratio = 9.1, 95% CI 7.5, 11.6). We conclude that compared to nonatopic physicians exposed to latex, or nonexposed atopic controls, atopic physicians who wear latex gloves are at increased risk of latex allergy.

Adult↗
PubMed1992

[Small cell (oat cell) carcinoma of the prostate. Presentation of a case and review of the literature].

Prostate small cell carcinoma (SCC) is a rare and fatal condition over which countless enigmas hover both with regard to its origin and biological behaviour as well as to its management, the topic of this paper. We contribute the case of a 69-year old male diagnosed through transrectal biopsy and presenting lung, nodes and bone metastasis who underwent palliative UTR but died within four days of the intervention as a consequence of the metastatic condition. Microscopic and immunohistochemical findings characteristic of this type of tumour are described, emphasising the relevance of diagnosing this entity based on its poor prognosis and different therapeutic approach from that used for typical prostate adenocarcinoma.

Aged↗
PubMed1989

Timing of the anesthetist's preoperative outpatient interview.

Hospitalization arouses anxiety among patients admitted for day bed surgery. The effect of the anesthetist's routine preoperative interview on the anxiety levels of 63 unpremedicated women scheduled for elective outpatient therapeutic abortions was examined using the State-Trait Anxiety Inventory. The anesthetist's preoperative interviews were performed at the following times: Group 1, in the outpatient clinic one week before surgery; group 2, in the day bed unit at the time of admission to hospital; group 3, outside the operating room immediately prior to surgery. State anxiety was measured before and after patients were seen by the anesthetists. In group 1, and in groups 1 and 2, it was readministered outside the operating room immediately before surgery. Baseline anxiety Trait and State scores were not significantly different in the 3 groups (Trait: group 1, 43.3 +/- 2.2; group 2, 36.9 +/- 2.3; group 3, 38.8 +/- 2.2. State: group 1, 50.6 +/- 3.5; group 2, 43.0 +/- 2.4; group 3, 49.0 +/- 3.0). Only in group 3 did the anesthetist's interview significantly reduce patient's anxiety (before visit 49.1 +/- 3.0; after visit 46.0 +/- 2.8; P less than 0.05). A small but statistically significant reduction in State anxiety scores is achieved when patients are seen by the anesthetist immediately prior to surgery.

Abortion, Therapeutic↗
PubMed1987

HDL clearance and receptor-mediated catabolism of LDL are reduced in hypothyroid rats.

Hypercholesterolemia associated with hypothyroidism is due partly to increased plasma LDL and partly to increased HDL cholesterol concentrations. The increase in LDL cholesterol has been shown to be secondary to reduced plasma clearance of LDL. To determine which catabolic route was thyroid dependent, the present study examined the effects of hypothyroidism on the receptor-mediated pathway and the 'receptor-independent' pathway of LDL metabolism. Wistar rats (327 +/- 22 g; mean +/- SD) were made hypothyroid by feeding propylthiouracil (0.1%, w/w) and rat 131I-LDL (rLDL; d = 1.019-1.050) and 125I-methylated-LDL (rLDL-CH3) were simultaneously injected i.v. after which the rates of clearance of labelled LDL in plasma were determined over 0-54 h. Total LDL and 'receptor-independent' clearances were represented by clearance of 131I-rLDL and 125I-rLDL-CH3 respectively and the difference between the two represented high affinity receptor-mediated clearance. The data were analyzed using Matthews' model and the fractional catabolic rates (FCR) were calculated. The FCR of rLDL clearance via the receptor-mediated pathway was 0.1042 +/- 0.0112 pools/h (n = 6) in controls vs. 0.0613 +/- 0.0079 pools/h (n = 6) in hypothyroid animals (P less than 0.01). The FCR via the 'receptor-independent' pathway was 0.0642 +/- 0.0040 pools/h (n = 6) in controls vs. 0.0561 +/- 0.0036 pools/h (n = 6) in hypothyroid animals (not significant). The plasma HDL cholesterol concentration was also increased in hypothyroid rats (70.4 +/- 6.7 mg/dl) compared to control (53.3 +/- 3.1 mg/dl) (P less than 0.025).(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1982

Purification and immunofluorescent localization of rat submandibular mucin.

Rat submandibular mucin (RSM) was purified by acid precipitation, then alcohol precipitation of the 30000g supernatant of gland homogenate, followed by column chromatography on Sephadex G-200. The mucin, which was eluted in the void volume, had an amino acid profile typical of a salivary mucus glycoprotein with high proportions of threonine, serine and proline (48.8% of total amino acids), and low proportions of aromatic and basic amino acids. It consisted of 63% (w/w) carbohydrate, which was shown by g.l.c. analysis to contain N-acetylglucosamine, N-acetylgalactosamine, galactose, sialic acid and fucose in the proportions 1.0:3.4:2.6:3.1:1.2. After staining of the mucin with periodic acid/Schiff reagent, analytical equilibrium ultracentrifugation in a CsCl density gradient produced a symmetrical peak of buoyant density 1.449g/ml, without evidence of protein contaminants. Sedimentation velocity centrifugation revealed a major periodate/Schiff-positive component (S(0) (20,w) 5.06) with an associated shoulder of slower sedimenting material, suggesting polydispersity in the size of the mucin. Our findings suggest that the RSM purified in these studies has a molecular weight between 200000 and 1x10(6). Antibody to RSM was prepared in a rabbit and produced a single precipitin line on immunoelectro-osmophoresis with the mucin. Immunofluorescence studies showed that the antibody localized only to submandibular acinar cells and confirmed that these cells were the source of RSM. The antibody was not directed towards the blood-group-A determinant (terminal N-acetylgalactosamine) present in the mucin.

Amino Acids↗