Biomedical subjects

L E Nelson

Publications and source records attributed to L E Nelson.

6 recordsLinked to original sources

PubMed2002

The sedative component of anesthesia is mediated by GABA(A) receptors in an endogenous sleep pathway.

We investigated the role of regionally discrete GABA (gamma-aminobutyric acid) receptors in the sedative response to pharmacological agents that act on GABA(A) receptors (muscimol, propofol and pentobarbital; 'GABAergic agents') and to ketamine, a general anesthetic that does not affect GABA(A) receptors. Behavioral studies in rats showed that the sedative response to centrally administered GABAergic agents was attenuated by the GABA(A) receptor antagonist gabazine (systemically administered). The sedative response to ketamine, by contrast, was unaffected by gabazine. Using c-Fos as a marker of neuronal activation, we identified a possible role for the tuberomammillary nucleus (TMN): when gabazine was microinjected directly into the TMN, it attenuated the sedative response to GABAergic agents. Furthermore, the GABA(A) receptor agonist muscimol produced a dose-dependent sedation when it was administered into the TMN. We conclude that the TMN is a discrete neural locus that has a key role in the sedative response to GABAergic anesthetics.

Anesthesia↗

PubMed2000

Aminoglycoside-resistance mechanisms for cystic fibrosis Pseudomonas aeruginosa isolates are unchanged by long-term, intermittent, inhaled tobramycin treatment.

Aminoglycoside-resistance mechanisms were characterized in Pseudomonas aeruginosa isolates from cystic fibrosis (CF) patients during a recent clinical trial of inhaled tobramycin. Impermeability, in which bacteria have reduced susceptibility to all aminoglycosides, was the predominant mode of resistance in isolates obtained both before and after 6 months of cyclic treatment with tobramycin or placebo administered by aerosol. Enzymatic resistance mechanisms were found in fewer than 10% of resistant isolates. P. aeruginosa from individual patients could be grouped on the basis of genetic relatedness. When enzymatic resistance was involved, all isolates in a group had elevated tobramycin MICs. When impermeability occurred, MICs of a genotypic group varied from susceptible to resistant. These findings suggest that impermeability resistance occurs in only a fraction of the P. aeruginosa population in lungs of persons with CF and that this form of resistance arises by a process involving multiple small changes in MIC.

Administration, Inhalation↗

PubMed1997

Onlay patch repair of tracheobronchial rupture.

Two cases are reported of tracheobronchial repair in which a posteriorly based intercostal muscle flap was incorporated into the membranous portion of the airway to increase the diameter of the reconstruction or to relieve tension in the suture lines. This technique permits repair of a small left main bronchus without compromise to the lumen and tension-free repair of the membranous trachea.

Adult↗

PubMed1986

The association of congenital ptosis and congenital heart disease.

Congenital ptosis and congenital heart disease are known to occur simultaneously in the presence of several well-recognized clinical syndromes. We report seven cases of documented, structural congenital heart defects found among 156 consecutive congenital ptosis patients operated at the Wills Eye Hospital. The possibility that the concurrence found in the patients was a manifestation of a dysmorphic syndrome was carefully excluded by observers skilled in the recognition of such anomalies. The observed rate of congenital heart disease, in otherwise normal congenital ptosis patients, was five times the expected rate in the pediatric population at large. This should alert ophthalmologists examining pediatric ptosis patients to the possibility of a coexisting structural heart defect.

Adolescent↗

PubMed1977

Adenocarcinoma in the columnar-lined (Barrett) esophagus. Case report and review of the literature.

As of 1975, forty-nine cases of adenocarcinoma arising in the columnar-lined lower esophagus (CLLE) were reported in the literature. We add three more cases, including the youngest male to our knowledge. All survived esophagogastrectomy and radiotherapy, but each had metastatic disease and a guarded prognosis. Review of the literature revealed a male/female ratio of 3:1 for this disorder with a mean age for men of 53 years, less than that for women, (61 women). Columnar-lined lower esophagus is seen in up to 11% of patients with reflux esophagitis and probably does not regress, once present. Adenocarcinoma later develops in 2.4% to 8.5%. The CLLE is not rare and should be followed up as carefully as any other premalignant lesion.

Adenocarcinoma↗

PubMedDate not supplied

Shared kangaroo care for triplets.

The mother in this case study already had four children at home and was afraid she would be unable to bond to three additional babies. This article describes her experiences with shared kangaroo care (holding all three infants at once), how these experiences relieved her fears, and how kangaroo care was extended by co-bedding the triplets in a single pediatric crib. Clinical nurse specialists and advanced nurse practitioners can use the successful outcome reported here to promote kangaroo care for families with naturally occurring triplets as well as those families whose triplets result from treatment for infertility.

Adaptation, Psychological↗