Search PubMed⌕ Search

Biomedical subjects

M S Gordon

Publications and source records attributed to M S Gordon.

88 records · Page 5Linked to original sources
PubMed1966

Lipids of the living coelacanth, Latimeria chalumnae.

The muscle of Latimeria chalumnae contains 30 to 71 percent (dry weight) of lipid deposited extracellularly. Wax esters constituted 90 percent or more of the lipids from muscle and fat storage tissues. These esters, by gaschromatographic analysis, consisted of C(30) to C(40) homologs with one or two double bonds.

Animals↗
PubMedDate not supplied

Boxfishes as unusually well-controlled autonomous underwater vehicles.

Boxfishes (family Ostraciidae) are tropical reef-dwelling marine bony fishes that have about three-fourths of their body length encased in a rigid bony test. As a result, almost all of their swimming movements derive from complex combinations of movements of their median and paired fins (MPF locomotion). In terms of both body design and swimming performance, they are among the most sophisticated examples known of naturally evolved vertebrate autonomous underwater vehicles. Quantitative studies of swimming performance, biomechanics, and energetics in one model species have shown that (i) they are surprisingly strong, fast swimmers with great endurance; (ii) classical descriptions of how they swim were incomplete: they swim at different speeds using three different gaits; (iii) they are unusually dynamically well controlled and stable during sustained and prolonged rectilinear swimming; and (iv) despite unusually high parasite (fuselage) drag, they show energetic costs of transport indistinguishable from those of much better streamlined fishes using body and caudal fin (BCF) swimming modes at similar water temperatures and over comparable ranges of swimming speeds. We summarize an analysis of these properties based on a dynamic model of swimming in these fishes. This model accounts for their control, stability, and efficiency in moving through the water at moderate speeds in terms of gait changes, of water-flow patterns over body surfaces, and of complex interactions of thrust vectors generated by fin movements.

Animals↗
PubMedDate not supplied

Synthesis of hydroxy and methoxy perylene quinones, their spectroscopic and computational characterization, and their antiviral activity.

Hydroxy and methoxy perylene quinones are synthesized in an attempt to isolate the essential spectroscopic and biological features of light-induced antiviral agents such as hypericin and hypocrellin. Unlike their naturally occurring counterparts, these synthetic quinones bear the carbonyl, hydroxyl, and methoxy groups in the "bay region." The hydroxy and methoxy compounds have rich absorption spectra with broad features in the visible (approximately 450-800 nm) and relatively more intense and narrow features at wavelengths < or = 350 nm. High-level ab initio quantum mechanical calculations assign the features in the absorption spectra to electronic transitions from S0 to S2 and to higher-lying electronic states. The calculations indicate that in the ground state the trans dihydroxy isomer is 12.5 kcal/mol lower in energy than the cis dihydroxy isomer and is thus the only species present. The lowest-energy trans methoxy ground state isomer and the lowest-energy cis methoxy ground state isomer are found to be degenerate. An additional cis methoxy isomer 6.3 kcal/mol higher in energy than the global minimum is assumed to contribute to the spectrum and is also considered. Finally, the synthetic compounds exhibit similar light-induced antiviral activity to each other, but significantly less than that of hypericin.

Antiviral Agents↗
PubMedDate not supplied

Variations in adequate levothyroxine replacement therapy in patients with different causes of hypothyroidism.

OBJECTIVE: To compare the levothyroxine replacement dose in 181 patients with various causes of hypothyroidism. METHODS: We analyzed the dose of levothyroxine used in the following five patient groups: (1) 37 patients with hypothyroidism after radioiodine therapy for Graves' thyrotoxicosis who were receiving a stable (for at least 4 years) replacement dose (mean time after 131 I therapy, 11.3 years); (2) 36 patients with Hashimoto's hypothyroidism (chronic autoimmune thyroiditis with a goiter or positive test results for antithyroid antibodies); (3) 36 patients with central hypothyroidism; (4) 36 patients with hypothyroidism after near-total thyroidectomy and 131 I therapy for thyroid carcinoma with negative total-body 131 I scans who were euthyroid when receiving levothyroxine; and (5) 36 patients with atrophic thyroiditis (no goiter and negative test results for antithyroid antibodies). Adequacy of levothyroxine replacement dose was defined as a normal thyrotropin level and clinical euthyroidism in patients with primary hypothyroidism and a serum free thyroxine index in the upper half of the normal range in conjunction with clinical euthyroidism in patients with central hypothyroidism. RESULTS: The mean (+/- standard error of the mean) replacement dosage of levothyroxine (mg/kg per day) in patients with atrophic thyroiditis (1.26 +/- 0.07) was lower (P<0.05) than in patients with Hashimoto's hypothyroidism (1.59 +/- 0.07) and those with hypothyroidism after radioiodine therapy (1.56 +/- 0.05). These doses, in turn, were lower (P<0.01) than those in patients with central hypothyroidism (1.88 +/- 0.10) or euthyroid thyroid carcinoma (2.08 +/- 0.07). In a separate analysis, the levothyroxine dose in 43 patients with hypothyroidism after 131 I treatment was evaluated serially over time. The mean levothyroxine dosage increased from 0.87 +/- 0.12 at 6 months after 131 I therapy to 1.57 +/- 0.09 at 7 years (P<0.001). The serum thyrotropin concentration (in mU/mL) during levothyroxine therapy in patients with central hypothyroidism (0.31 +/- 0.08) was lower (P<0.01) than in patients with hypothyroidism after 131 I therapy (1.69 +/- 0.37), Hashimoto's hypothyroidism (1.39 +/- 0.20), atrophic thyroiditis (1.86 +/- 0.22), and euthyroid thyroid carcinoma (1.48 +/- 0.26). CONCLUSION: The levothyroxine replacement dose varies with the cause of the hypothyroidism.

Journal Article↗
PubMedDate not supplied

The use of granulocyte colony-stimulating factor in the treatment of fever and neutropenia in a heart transplant patient.

We had the opportunity to study the clinical effects of granulocyte colony-stimulating factor in a heart transplant patient with a classic febrile neutropenic episode that was thought to be caused by immunosuppressive therapy. Administration of granulocyte colony-stimulating factor resulted in rapid recovery of his absolute neutrophil count, with resolution of fevers. Endomyocardial biopsy showed no pathologic evidence of worsened rejection. The use of hematopoietic cytokines after the organ allograft requires further study before it can be routinely advocated in this patient population.

Adult↗
PubMedDate not supplied

When does a nurse become a "supervisor" under federal law?

With restructuring and skill-mix changes, nurses are delegating and coordinating nursing skills. Does this mean they are "supervisors" and not protected by the National Labor Relations Act? Not necessarily. These authors clarify several myths related to the Supreme Court ruling on nurses as supervisors and analyze case examples where nurses have been, and have not been, considered supervisors.

Hospital Restructuring↗