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Biomedical subjects

L Contreras

Publications and source records attributed to L Contreras.

41 records · Page 3Linked to original sources
PubMed1980

Anatomy of reproductive tract in Octodon degus Molina: a nonscrotal rodent.

O. degus reproductive tract is characterized externally by a perianal circle with the penis pointing posteriorly. Beneath the perianal circle is the cremasteric sac. Testes are always inside the abdomen, with the epididymis attached to them but the cauda epididymis lays inside the cremasteric sac. Vas deferens and seminal vesicles open independently into the urethra. Three pairs of lateral prostatic lobes open by many ducts into the urethra. The corpora spongiosa holds the urethra in the ventral groove of the corpus cavernosum. The corpus cavernosa are inserted into the bulbo cavernosum muscle and at its distal end are attached to the base of the baculum, that lay under the dorsal face of the glans. The glans has two openings: the urinary meatus and the intromittent sac. The characteristics of the testicular artery agree with the anatomy expected for animals with intrabdominal testes; it is relatively short, with few loops and a wide diameter. Many of these anatomical features are shared by other caviomorphal rodents. If testicular temperature is similar to body temperature in these animals as in O. degus (36.0 degrees and 37.2 degrees C respectively), they would exhibit little testicular thermal sensibility. Among these rodents O. degus has the lowest body temperature. Moreover this work reinforces the hypothesis that descent of the testis into the scrotum has occurred secondarily to the immigration of the cauda epididymis.

Animals↗
PubMed1975

Oxygen transport of hemoglobin in high-altitude animals (Camelidae).

To clarify the mechanisms by which high-altitude Camelidae can adapt to hypoxia, the study of some blood characteristics were carried out in apacas and llamas. The results show that there is a peculiar dissociation curve of hemoglobin in alpacas which permits great affinity of hemoglobin for oxygen at lung level and the release of oxygen at the tissue level with a facility similar to that in man. Fetal hemoglobin was found high in adult alpacas (55 percent). Electrophoretic studies of hemoglobin showed that this pigment has two components, both of which have a very low mobility. Lactic dehydrogenase was found six times higher than in humans. RBC glucose-6-phosphate dehydrogenase was two times higher than in man living at the same altitude. Myoglobin was found to be higher than in man living at altitude. Alpacas have erythrocytes in which the amount of 2,3-DPG is approximately the same as in man. RBC are more resistent to hypotonic solutions than humans. The amount of lactic dehydrogenase, myoglobin, and glucose-6-phosphate dehydrogenase dimishes when alpacas are bought down to sea level.

Adaptation, Physiological↗
PubMedDate not supplied

[Tracheoesophageal fistula secondary to ingestion of a button battery].

An eleven month old girl was admitted to a county hospital because of persistent low grade fever, cough, vomitus and food and oral fluids rejection. A small radiopaque, button sized, round object was seen impacted in the upper esophageal third on X ray examination and later extracted by endoscopy, corresponding to an electric cell, from a father's handwatch, which had been ingested by the baby without knowledge of parents about 30 h before. After 12 h fasting, oral feedings were resumed being apparently well tolerated, but in the following day fever and respiratory distress reappeared, together with drooling, cianosis, abdominal distention and pale skin. Patient was transferred to a regional hospital where extensive bilateral pneumonia and anemia were documented. Gastric drainage via nasogastric tube, antibiotic treatment, blood transfusion and oxygen therapy were given from admission, but she died within a few hours. At necropsy a 3 per 2.5 cm diameter orifice of sharp borders was seen in the upper third of the esophagus, communicating to tracheal lumen through its upper six cartilages. Extensive, severe, bilateral pneumonia was confirmed. When this kind of electric cells become impacted into the esophagus, wall necrosis may occur within 4 h and perforation within 8 to 12 h and can be prevented by immediate endoscopic extraction. Otherwise fistulae should be suspected and patients managed accordingly. Emergency room medical staff must always be aware of this potentially lethal condition and its proper management. Infants should not be permitted to play with such apparently innocent objects as battery operated handwatches.

Electric Power Supplies↗
PubMedDate not supplied

[Treatment of pediculosis capitis in children with permethrin 1% shampoo or lotion].

A clinical and entomological trial was carried out in 88 head louse (Pediculus humanus capitis) infested children treated with a single dose of 1% permethrin shampoo or lotion. The sex distribution was 47 males an 41 females with ages ranging between 5 and 14 year olds. In order to assess the efficiency of treatments, search for adult forms, nymphs and eggs (nits) of the parasite was performed in each of the children, before and after treatment (30 minutes, 7 days and 21 days). The entomological evaluations consisted in stereoscopic and microscopic examinations of a mean of 12 hair samples taken from the retroauricular and occipital regions of each of the children, the biological condition of eggs, viable (immature, mature), dead and empty, was recorded. The cure rates--both clinical and entomological--obtained were 91.5% for shampoo and 95.2% for lotion. No adverse reactions with the two formulations used were reported. In conclusion, 1% permethrin shampoo or lotion in an effective and safe treatment for pediculosis capitis.

Administration, Topical↗