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Biomedical subjects

R Rincón

Publications and source records attributed to R Rincón.

12 recordsLinked to original sources
PubMed2000

[Occupational exposure and health effects of metallic mercury among dentists and dental assistants: a preliminary study. Valencia, Venezuela; 1998].

The aim of this investigation was to establish mercury (Hg) health effects on dentists and dental assistants, its relationship with exposure conditions and the potential renal damage Hg-related. The total population was 66 people, with a sample of 37 (56%), 22 dentists (59.5%, 19 male, 3 female) and 15 dental assistants (40.5%, all female). This was accomplished by an interview, Hg in urine (Hg-U) and N-acetyl-B-D-glucosaminidase activity in urine (NAG-U). Average values of Hg-U for dentists were 22.4 +/- 6.4 micrograms/g creatinine and 22.2 +/- 6.1 micrograms/g creatinine for dental assistants NAG-U average values were 2.9 +/- 3 U/L and 5.2 +/- 8.1 U/L respectively. There were no statistically significant differences between these averages (p > 0.05). There was no correlation between the quantity of amalgam prepared and working hours with Hg-U and NAG-U. Most frequent symptoms referred by dentists were: irritability (54.5%), cephalalgia (45.4%), arthralgias (40.9%), and the ones more referred by assistants were arthralgias (53.3%), irritability (46.7%) and cephalalgia (46.7%). It was not found a significative risk of having them among these groups. There is a need for further investigations including environmental monitoring of Hg, clinical evaluation and neurobehavioural tests to detect early effects. It is important to enforce personal safety measures to control the exposure.

Acetylglucosaminidase↗
PubMed1996

Absence of an early pre-emptive effect after thoracic extradural bupivacaine in thoracic surgery.

We have determined if thoracic extradural block before surgical incision for thoracotomy produces pre-emptive analgesia. Using a double-blind, placebo-controlled, crossover design, 45 patients (ASA II-III) undergoing posterolateral thoracotomy for lung resection were randomized to one of three groups: group 1 received 0.5% bupivacaine and adrenaline 1/200,000 (B+E) 8 ml through a thoracic extradural catheter (tip T3-T5) 30 min before skin incision and saline 8 ml 15 min after skin incision; group 2 received saline 8 ml extradurally before incision and B+E 8 ml after incision; group 3 received saline 8 ml extradurally before and after incision. General anaesthesia was induced and maintained with propofol, alfentanil and atracurium. The alfentanil infusion was stopped before chest closure and fentanyl 50 micrograms in saline 10 ml was given extradurally. Patient-controlled extradural analgesia (PCEA) was commenced with 0.125% bupivacaine, adrenaline 1/400,000 and fentanyl 6 micrograms ml-1 (continuous rate of 2 ml h-1 and supplementary doses of 0.5 ml per 6 min). Visual analogue scale (VAS) scores (recorded at rest, on mobilization and after cough), verbal rating scale (VRS) (recorded at rest), number of successful PCEA demands and complications were measured during the first 48 h after operation. There was no significant difference between groups, either in PCEA requirements (P > 0.21) or in VAS scores (either at rest, during mobilization of the ipsilateral arm of surgery or after cough). No significant differences between groups were found in the VRS. Thoracic extradural block with bupivacaine did not produce an early preemptive effect after thoracotomy.

Adult↗
PubMed1996

Thoracic epidural anesthesia via the lumbar approach in infants and children.

BACKGROUND: In upper abdominal or chest surgery, the segmental approach to thoracic epidural space has the advantage of reducing the total dose of local anesthetic needed. This approach, however, is associated with greater risk of neurologic damage or dural puncture. The aim of this study was to assess the success and the degree of difficulty in advancing a 19-G catheter from the lumbar epidural space to the thoracic level in patients aged 0-96 months. METHODS: In 39 patients undergoing abdominal surgery, the cutaneous distance between the L4-L5 and T10-T11 interspaces was measured, and an appropriate length of 19-G catheter was inserted into the epidural space through an 18-G Tuohy needle with bevel directed cephalad. The intent was to advance the full length of catheter measured to reach the objective. The tips were observed radiologically, and all those positioned cephalad to the T12 level were considered well placed. The degree of difficulty in advancing the catheter was classified as easy, difficult, or impossible. Complications reported were vascular and/or spinal puncture and difficulty removing the catheter. RESULTS: The catheter tip reached T10-T12 in 7 patients, L2 in 1, L3 in 8, and L4-L5 in 23. Forty-eight percent of the catheters described as easily advanced remained at the L4-L5 level, and only 22% reached the desired level. Difficult insertions occurred in eight patients, in whom the objective was never reached. One case of intravascular insertion was reported. All catheters were removed without difficulty. CONCLUSIONS: The 19-G catheter is inappropriate for use in reaching the thoracic epidural space by the lumbar approach. Easy entrance of a catheter is not a reliable sign of having reached the desired level.

Anesthesia, Epidural↗
PubMed1994

Acid aspiration prophylaxis in elective biliary surgery. A comparison of omeprazole and famotidine using manually aided gastric aspiration.

We have compared the effects of single oral doses of omeprazole 40 mg, famotidine 40 mg or placebo on gastric secretion in 45 non-obese patients the night before elective biliary surgery. After stable anaesthesia had been established, a Salem orogastric tube was introduced and gastric contents were aspirated by a blinded observer. The volume and pH were noted. After the abdomen was opened aspiration was repeated but on this occasion with the surgeon's manual assistance. We found that the initial aspirate volume underestimated total gastric volume by an average (SD) of 7.1 (6.6) ml. Famotidine, but not omeprazole, produced a significant decrease in gastric volume and acidity. Patients were considered to be at risk if pH < 2.5 and volume > 0.4 ml.kg-1. Three patients in the omeprazole group, three in the placebo group and none in the famotidine group came into this category. We conclude that a single oral dose of omeprazole 40 mg given the night before surgery does not afford adequate prophylaxis for acid aspiration syndrome.

Adult↗
PubMed1991

[Kaposi's sarcoma with primary pulmonary involvement in a parenteral drug addict with acquired immunodeficiency syndrome].

Pulmonary Kaposi's sarcoma (KS) was diagnosed by pulmonary biopsy in a heterosexual parenteral drug abuser (PDA). The patient had previously been diagnosed of Pneumocystis carinii pneumonia and pulmonary tuberculosis. Thoracic computed tomography (CT) showed bilateral nodular lesions which were less apparent in conventional radiological study and which increased in size in spite of correct therapy. As cutaneous lesions suggesting KS subsequently appeared, the possibility of pulmonary KS was considered and confirmed by open biopsy. The rarity of a primarily pulmonary presentation of KS in a PDA, the difficulty in diagnosis owing to concomitant infective diseases and the diagnostic value of thoracic CT for the diagnosis of pulmonary KS are discussed.

Acquired Immunodeficiency Syndrome↗
PubMed1979

Effect of Krebs cycle intermediates and inhibitors on toad gastric mucosa.

An attempt to increase the permeability of gastric mucosa to exogenous Krebs cycle intermediates seemed advisable for a better understanding their relationship with acid secretion. At pH 7.4, citrate, oxoglutarate, fumarate, and malate had no significant effect on oxygen uptake (QO2) nor on acid secretion (QH+) by toad gastric mucosa; succinate increased QO2 slightly and had no effect on QH+; but at pH 5.0, oxoglutarate and succinate increased QO2 by 18 and 21%, respectively. 14CO2 evolved by gastric mucosa incubated with [14C]oxoglutarate, succinate, malate, or citrate was 155, 92, 128, and 353%, respectively, greater at pH 5. Citrate, oxoglutarate, succinate, fumarate, and malate increased QH+ by theophylline-stimulated mucosa at pH 5.0 by 25, 39, 35, 17 and 28%, respectively. Oxoglutarate-dependent respiration was shown to correlate with oxoglutarate oxidation. Malonate and arsenite inhibited QO2 and QH+; malonate inhibition was reversed by washout or by succinate. Arsenite was reversed by washout and accelerated by addition of lipoate immediately after washout. The results suggest that the Krebs cycle has concomitant roles in the regulation of QH+ and oxidative metabolism in the toad gastric mucosa.

Animals↗
PubMedDate not supplied

Pesticide exposure in a farming village in Venezuela--a developing country.

This study was designed and performed by the Universidad de Carabobo, Centro de Investigaciones Toxicológicas, Venezuela, and the University of Cincinnati Department of Environmental Health. The authors tested methodology and analyzed preliminary data on demographics, pesticide use, health, environment, and lifestyles in a farming community in Venezuela (population = 386; sample size = 81) to determine if pesticide misuse might have been contributing to public health problems. Questionnaire and geographic information were collected. There were statistically significant incidences of pesticide-related symptoms (p < .01) in farmers versus nonfarmers (odds ratio = 5.7; 95% confidence interval = 2.9, 18.8). In addition, in one area there was a cluster of farmers who experienced symptoms that appeared to be the result of foul air and proximity to farms where there was pesticide use. The results of the study indicated that this public health problem may have been associated with pesticide misuse; however, additional studies are needed to corroborate the findings.

Adolescent↗