Search PubMed⌕ Search

Biomedical subjects

D C Peterson

Publications and source records attributed to D C Peterson.

16 recordsLinked to original sources
PubMed1999

GTP (gammaS) and GDP (betaS) as electron donors: new wine in old bottles.

G proteins are membrane-bound regulatory proteins which modulate the activity of ion channels and other effector systems. The GTP and GDP analogs GTP (gammaS) and GDP (betaS) have been used to study the role of G proteins in numerous physiologic systems. The prolonged effects of these analogs have been thought to be due to the fact that they are nonhydrolyzable. However, in this paper we show that the GTP (gammaS) and GDP (betaS) analogs are potent reducing agents at physiologic pH. This observation suggests that previous data obtained using these compounds may need to be reinterpreted.

Cytochrome c Group↗
PubMed1996

Immunizations in long-term care facilities: policies and practice.

PURPOSE: The present study was conducted to assess the policies and practices of nursing homes in regard to immunizations for residents and employees. METHODS: A 20-item, cross-sectional survey was mailed to all 445 Minnesota nursing homes from May through July 1993. Questions asked were about facility characteristics and their policies, practices, and attitudes regarding immunizations for residents and employees. Second and third mailings were sent to nonresponding institutions. RESULTS: The median size of 399 (90%) responding institutions was 88 beds and 110 employees. The median number of residents on December 1, 1992, was 84. Although 99% of the facilities had an influenza vaccination program, only 69.3% had written policies. The mean influenza vaccination rate for residents was 84%, with higher rates in institutions having written policies, facility-wide standing orders for vaccine administration, and in institutions that did not require written consent for vaccination. One-third of the facilities had written policies for pneumococcal vaccination, and 16.3% had policies for tetanus/diphtheria. Twelve-month immunization rates for these vaccines were 11.9% and 2.9%, respectively. Most facilities had an influenza vaccination program for employees with a mean vaccination rate of 33%. These rates were higher if the facility offered vaccine onsite, free of charge, and provided special inservice education to employees. Employee 12-month vaccination rates for hepatitis B and tetanus/diphtheria were 23.2% and 1.7%, respectively. Few of the institutions included evaluation of immunization activities in their quality assurance programs. CONCLUSION: Many long-term care facilities have inadequate policies and practices for ensuring their residents and employees immunity to important vaccine preventable diseases. These institutions, as caretakers for a vulnerable population, should develop and implement organized programs to immunize their residents and employees. By doing so, they will be able to take advantage of important opportunities to prevent illness and protect the health of their residents and employees.

Aged↗
PubMed1996

Assay of anticancer drugs in tissue culture: comparison of a tetrazolium-based assay and a protein binding dye assay in short-term cultures derived from human malignant glioma.

Because of the methodological difficulties associated with the MTT assay in screening short-term cultures derived from human malignant glioma, a chemosensitivity assay based on the protein staining using sulforhodamine B (SRB) has been optimized for use with these cells. SRB at a fixed dye concentration achieved maximal staining density at 20 min for most cell lines and this intensity was not further increased by using dye concentrations above 0.2%. A delay in staining after fixation did not significantly decrease staining intensity, but delay in dye extraction after fixation and staining did. There was an excellent quantitative and qualitative linear relationship between cell number determined by either the SRB assay or by cell counting, but not with the MTT assay which consistently underestimated the number of cells in assay plates. The MTT assay appeared to be incapable of detecting less than about 150 cells/well, while these small numbers of cell were readily detectable by either cell counting or SRB staining. There was a close correlation between chemosensitivity values derived from the MTT and SRB assays for procarbazine, CCNU and vincristine when the endpoint is taken as either the ID25, ID50 or ID75. The results indicate that the SRB is capable of producing broadly similar results to the MTT assay, but is more sensitive in the detection of small numbers of cells with a linear relationship between cell number and SRB staining intensity over a wide range of cell numbers. It is capable of producing data from short-term cultures from malignant glioma and offers technical advantages over the MTT assay in that plates may safely be stored at certain points during the assay without the need for immediate processing. The SRB assay provides a useful alternative to the MTT assay for determining the sensitivity of short-term cultures of human glioma to cytotoxic drugs.

Antineoplastic Agents↗
PubMed1995

Shoulder arthroscopy and nerve injury: pitfalls and prevention.

Shoulder arthroscopy has become a very useful diagnostic and therapeutic modality. Unfortunately, like many other invasive procedures it can have complications. One of the most worrisome complications, for both the patient and surgeon, is that of nerve injury. Nerve injury during shoulder arthroscopy is often a transient phenomenon although a more severe injury has been documented. We review much of the literature on this subject and discuss some of the many pitfalls and preventative strategies that have been reported.

Arthroscopy↗
PubMed1994

Hospital-based strategies for improving influenza vaccination rates.

BACKGROUND: Patients at highest risk for complications from influenza have the lowest rates of vaccination. Each year there are thousands of deaths related to influenza. Many of those who are hospitalized or who die from influenza-related conditions were hospitalized during the preceding influenza vaccination season but not vaccinated. METHODS: Six community hospitals in northern Minnesota participated in a pilot project to assess the feasibility and effectiveness of three different community hospital-based influenza vaccination programs during the 1991-1992 immunization season. Records of patients discharged from each institution during November and December 1991 were reviewed for documentation of indications for influenza immunization and to determine whether vaccination was offered and whether vaccination occurred before discharge. RESULTS: In hospitals choosing to implement standing orders for their nursing staffs to review indications for influenza vaccination and administer if indicated, 95.2% of patients were offered vaccination. In hospitals depending on physician chart reminders, 22% of patients were offered vaccination. In hospitals relying on physician education strategies to promote influenza vaccine, only 11.7% of patients were offered vaccination. Documented immunization rates in these three groups were 40.3%, 17%, and 9.6%, respectively. CONCLUSIONS: Programs implementing standing orders for nursing staffs were more effective than educational programs or physician reminders in offering and administering influenza vaccine to hospitalized patients. Hospital policies can expand the number of high-risk and elderly persons who receive influenza vaccination each year, but hospitals need to be reimbursed for this service to ensure institutional support.

Hospitalization↗
PubMed1992

The non specificity of specific nitric oxide synthase inhibitors.

L-NAME (Nw-Nitro-L-arginine methylester) and L-NMMA (NG- Monomethyl-L-arginine, monoacetate) are used widely as nitric oxide (NO) synthase inhibitors. Because of their functional groups (alcohols, amines and carboxylates), it appeared that they could interact with iron in a variety of systems. Using three in vitro models we observed these two compounds had inhibitory effects on cytochrome C reduction by ferrous iron, by ferrous iron accelerated by an unsaturated fatty acid or by epinephrine. This suggests that L-NAME and L-NMMA could have effects in iron containing systems found intracellularly apart from their inhibition of (NO) synthesis.

Amino Acid Oxidoreductases↗
PubMed1983

Synthesis and platelet aggregation inhibiting activity of prostaglandin D analogues.

Several prostaglandin D (PGD) analogues have been synthesized, incorporating the following variations: (a) varying degrees of side-chain unsaturation, (b) C-9 hydroxy removed or in the unnatural 9 beta configuration, (c) metabolically stabilized analogues (e.g., 15-methyl, 16,16-dimethyl, 17-phenyl, etc.), and (d) delta 12 isomers resulting from decomposition of PGD2. With regard to their ability to inhibit adenosine diphosphate (ADP) induced human platelet aggregation: (a) PGD3 greater than or equal to PGD2 greater than PGD1 greater than 13,14-dihydro-PGD1, (b) the 9 beta- and 9-deoxy-PGD2 analogues are more potent than PGD2, (c) metabolically stabilized analogues with bulky substituents at or near C-15 have substantially reduced antiaggregatory activity relative to PGD2 and (d) the delta 12 isomers of PGD2 are much less active than PGD2.

Animals↗
PubMed1983

Synthesis and biological activity of prostaglandin lactones.

Most of the primary prostaglandins and several biologically important prostaglandin analogues were converted to 1,9-, 1,11- or 1,15-lactones, in order to investigate the biological profiles of these internal esters and to assess their potential as prodrugs for the corresponding open-chain hydroxy acids. In each case, the key lactonization step was done using Corey's "double activation" procedure (cyclization of omega-hydroxy-2-pyridinethiol esters). In general, the 1,9-lactones exhibited less than 1% of the biological activity of the parent hydroxy acids in the standard prostaglandin test systems. The 1,11- and 1,15-lactones, on the other hand, were essentially equal to the parent hydroxy acids as antifertility agents (a 4-day assay which would allow time for in vivo enzymatic lactone hydrolysis). The 1,11- and 1,15-lactones exhibited very low activity in acute or in vitro screens (e.g., rat blood pressure and gerbil colon stimulation), assays which more closely reflect the intrinsic activity of the lactones themselves. These results are consistent with the observed relative ease of enzymatic hydrolysis of the prostaglandin lactones (1,15 greater than or equal to 1,11 much greater than 1,9). Several of the lactones whose parent hydroxy acids are resistant to metabolic inactivation (e.g., 15-methyl, 16-phenoxy, and 17-phenyl) exhibited potent abortifacient activity in the hamster. These lactones, with greatly diminished activity in the blood pressure and smooth muscle assays (indicators of potential side effects), represent a therapeutically useful class of antifertility agents.

Animals↗
PubMed1981

Aminoglycosides. V. Synthesis of glucopyranoside derivatives of neamine modified in the 2-deoxystreptamine ring.

trans-4-Aminocyclohexanol-2'-amino-alpha-D-glucopyranosides were prepared which are derivatives of neamine having the 3-amino and 5 and 6 hydroxyl groups of the 2-deoxystreptamine ring replaced with hydrogen. The 2'-amino-alpha-glycosides were synthesized by the method of LEMIEUX using a chloro nitroso dimer of a glucal and appropriately substituted cyclohexanols. Reductive deblocking of the intermediate 2-oximino derivatives afforded paromamine and neamine analogues. Two examples of 2'-amino-alpha-glycosides with ring-opened variations of the 2-deoxystreptamine aglycone are described. None of the compounds exhibited better in vitro antibacterial activity than neamine when compared against Gram-positive and Gram-negative bacteria.

Bacteria↗
PubMed1977

Inhibition of human platelet thromboxane synthetase by 9,11-azoprosta-5,13-dienoic acid.

The synthetic prostaglandin analog 9,11-azoprosta-5,13-dienoic acid (azo analog I) has been found to be a potent inhibitor of human platelet thromboxane synthetase by three independent analytical methods: electron-capture gas chromatography, radioisotopic thin-layer chromatography, and radioimmunoassay. In the presence of azo analog I, human platelet aggregation induced by either the prostaglandin endoperoxide PGH2 or arachidonic acid was antagonized. The addition of azo analog I shifted the transformation of endoperoxides away from thromboxane synthesis and toward prostaglandin E2 synthesis. The specificity of azo analog I is demonstrated by its selective inhibition of the second wave of either ADP- or epinephrine-induced platelet aggregation. These data indicate that PGH2 must be converted to thromboxane A2 in order to induce human platelet aggregation.

Arachidonic Acids↗