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Biomedical subjects

L Nichols

Publications and source records attributed to L Nichols.

At least 55 records · Page 3Linked to original sources
PubMed1989

Bacterial infections in the acquired immune deficiency syndrome. Clinicopathologic correlations in a series of autopsy cases.

In a group of 46 adult patients with acquired immunodeficiency syndrome (AIDS) who came to autopsy in 1983-1987, the authors found that 38 (83%) had bacterial (nonmycobacterial) infections some time during the course of their illness, compared with 34 (74%) who had parasitic infections, 31 (67%) who had viral infections, 28 (61%) who had fungal infections, and 12 (26%) who had mycobacterial infections. Twenty-five of these patients (54%) had Staphylococcus aureus infections, compared with 7 (15%) who had Pseudomonas aeruginosa infections and 6 (13%) who had enterococcal infections. Overall, undiagnosed infections or malignancies were found in 48%, 22 of the 46 autopsies, including 12 cases of undiagnosed bacterial infections, 8 of these due to S. aureus. These results suggest that bacterial infections in general, and S. aureus infections in particular, are important causes of morbidity and mortality in patients with AIDS.

Acquired Immunodeficiency Syndrome↗
PubMed1989

Percutaneous aortic valvuloplasty procedure and implications for nursing.

Percutaneous transluminal aortic balloon valvuloplasty (PTABV) is a procedure performed in the cardiac catheterization laboratory for some patients with severe calcific aortic stenosis. A review of the literature indicated that the procedure was beneficial to elderly patients or those who were poor candidates for surgery. The common complications of PTABV include bleeding at the catheterization site and vagal reactions during groin compression. Nursing implications in the cardiac catheterization laboratory involve ensuring patient comfort, managing the effects of cardiac instrumentation, and monitoring vital signs and vascular integrity. Post-PTABV nursing diagnoses include: (1) potential for injury or hemorrhage, (2) potential for alteration in cardiac output, (3) potential for alteration in tissue perfusion, (4) alteration in comfort, (5) potential for infection, and (6) knowledge deficits.

Aged↗
PubMed1988

Dependence of M1 RNA substrate specificity on magnesium ion concentration.

We have constructed a plasmid expressing E. coli M1 RNA, the catalytic RNA subunit of ribonuclease P, under the control of a phage T7 promoter. The active M1 RNA species synthesized in vitro by T7 RNA polymerase from this vector was reacted with the tRNA(Gln) - tRNA(Leu) precursor RNA (Band K) encoded by phage T4. Only the tRNA(Leu) moiety of this dimeric precursor RNA contains the 3' terminal C-C-A sequence common to all tRNAs. We observed that protein-free M1 RNA was capable of processing the precursor RNA at the 5' ends of both tRNA tRNA sequences. The rate of cleavage of the tRNA(Gln) sequence was more strongly dependent on [Mg2+] than that of tRNA(Leu), increasing severalfold between 100 and 500 mM Mg2+, conditions under which the rate of cleavage at the tRNA(Leu) sequence was constant.

Base Sequence↗
PubMed1988

Cortical cytoskeleton of giant moth eggs.

Unfertilized eggs of several species of giant moths contain a substantial cortical cytoskeleton. This structure is assembled during oogenesis, and contains actin as a major fibrillar component. The presence of actin was confirmed by gel electrophoresis and binding to phalloidin, DNase I, and a monoclonal antibody against cytoskeletal actin. Several lines of evidence suggest that the fat body is a source of the actin in the oocyte and that the transport and acquisition of actin by the ovary are similar to the mechanism of vitellogenin acquisition. A possible role for the cortical cytoskeleton in directing early embryogenesis is discussed.

Actins↗
PubMed1988

The Hox-2 homeo box gene complex on mouse chromosome 11 is closely linked to Re.

Restriction fragment length polymorphisms have been identified between inbred strains of mice for the homeo box gene complex Hox-2. These genetic markers were used to follow the segregation of different Hox-2 alleles among recombinant inbred strains of mice and among the progeny of a three point genetic cross. The results place the Hoax-2 locus approximately 1 cM from the rex (Re) locus on mouse chromosome 11.

Alleles↗
PubMed1987

Perforation of the terminal ileum with cytomegalovirus vasculitis and Kaposi's sarcoma in a patient with acquired immunodeficiency syndrome.

This case report documents a perforation of the terminal ileum in a 40-year-old white male homosexual with the acquired immunodeficiency syndrome. The perforation occurred at a site that had severe cytomegalovirus infection and was in close proximity to multiple nodules of Kaposi's sarcoma. The ileum showed multiple deep ulcers with large numbers of cytomegalovirus inclusions and vasculitis with infected endothelial cells, small-vessel thrombosis, focal disruption, and hemorrhage. We review the evidence that cytomegalovirus infection--and not Kaposi's sarcoma--was responsible for this perforation and, in light of the new medical therapy for such infections, should be regarded as an important cause of gastrointestinal perforation in patients with the acquired immunodeficiency syndrome.

Acquired Immunodeficiency Syndrome↗
PubMed1986

Nutritional assessment of community-living well elderly.

Nutritional assessment parameters were studied in a sample of 132 community-living well elderly. Results are presented for biochemical parameters of serum albumin, hemoglobin, and total lymphocyte count and anthropometric parameters of height, weight, mid-arm circumference, and triceps skinfold. The data show that, although there are some differences between age groups (young-old and old-old), all values remain well within normal limits established for younger individuals.

Aged↗
PubMed1985

The emergence of resistance to beta-lactam antibiotics during treatment of Pseudomonas aeruginosa lower respiratory tract infections: is combination therapy the solution?

Treatment of Pseudomonas aeruginosa lower respiratory tract infections with beta-lactam antibiotics alone (beta-lactam monotherapy) has been thought to result in a high incidence of therapeutic failure due to the emergence of multiply-resistant strains on the basis of induction of a chromosomal beta-lactamase. Review of published experience in patients without granulocytopenia or cystic fibrosis suggests that favorable clinical responses can be obtained in 80-90% of cases, and bacteriological cures in 45-55%, using any of the newer beta-lactam antipseudomonal agents alone (data from cefsulodin, cefoperazone, azlocillin and piperacillin). Resistance develops in 30-40% of the infecting organisms, and is associated with treatment failure in 10-20% of cases (data from cefsulodin, ticarcillin and carbenicillin). Cross-resistance to other beta-lactams and to aminoglycosides can occur but seems unlikely to be on the basis of induction of a chromosomal beta-lactamase (data from cefsulodin). The addition of an aminoglycoside antibiotic (combination therapy) has been recommended to prevent these outcomes. Retrospective comparison with results obtained using combination therapy in patients without granulocytopenia or cystic fibrosis suggests that the addition of an aminoglycoside cannot be expected to prevent either the development of resistance or therapeutic failure (which are frequently unassociated). Treating every patient with a Pseudomonas aeruginosa lower respiratory tract infection with combination therapy will expose all of them to the toxicity of an aminoglycoside but will rarely repay this risk with the prevention of a multiply resistant strain or the salvage of a patient destined to fail beta-lactam monotherapy.

Aminoglycosides↗
PubMed1981

Beta-endorphin levels in blood from selected Alaskan mammals.

Blood samples were analyzed for beta-endorphin from 43 non-torpid black bear (Ursus americanus), 8 torpid black bear, 3 non-torpid brown bear (Ursus arctos), 14 moose (Alces alces), 6 mountain goats (Oreamnus americanus) and 30 Steller sea lions (Eumetopias jubatus). Beta-endorphin levels were detected in all species sampled and there were no significant differences in levels among non-torpid black bear, brown bear and sea lions. Also, no differences were detected between moose and mountain goats, but all other comparisons were significantly different (P less than 0.001). Torpid black bear had higher levels than all other groups. Moose and mountain goats had the lowest levels. The possibility of beta-endorphin influencing behavior and physiology of mammals is discussed.

Alaska↗
PubMed1972

How genetic background masks single-gene heterosis in Drosophila (polymorphism-selection-isoenzymes-inbreeding-fly).

Conditional heterosis associated with two isoallelic forms of octanol dehydrogenase in Drosophila pseudoobscura has been detected in flies that have been (a) inbred for several generations to make the background genotype as homozygous as practicable, and (b) grown on a medium containing a small amount of octanol. The heterosis was first found in inbred males. The possibility that the effect in females was masked by X-linked polymorphic genes affecting the same fitness components as the locus for octanol dehydrogenase was shown to be correct when, on further inbreeding, heterosis was found in the females of one of the lines. The implications of this and other findings for the current understanding of the genetic structure of natural populations is discussed.

Alcohol Oxidoreductases↗