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Biomedical subjects

D Plante

Publications and source records attributed to D Plante.

13 recordsLinked to original sources
PubMed2000

Complex formation between potyvirus VPg and translation eukaryotic initiation factor 4E correlates with virus infectivity.

The interaction between the viral protein linked to the genome (VPg) of turnip mosaic potyvirus (TuMV) and the translation eukaryotic initiation factor eIF(iso)4E of Arabidopsis thaliana has previously been reported. eIF(iso)4E binds the cap structure (m(7)GpppN, where N is any nucleotide) of mRNAs and has an important role in the regulation in the initiation of translation. In the present study, it was shown that not only did VPg bind eIF(iso)4E but it also interacted with the eIF4E isomer of A. thaliana as well as with eIF(iso)4E of Triticum aestivum (wheat). The interaction domain on VPg was mapped to a stretch of 35 amino acids, and substitution of an aspartic acid residue found within this region completely abolished the interaction. The cap analogue m(7)GTP, but not GTP, inhibited VPg-eIF(iso)4E complex formation, suggesting that VPg and cellular mRNAs compete for eIF(iso)4E binding. The biological significance of this interaction was investigated. Brassica perviridis plants were infected with a TuMV infectious cDNA (p35Tunos) and p35TuD77N, a mutant which contained the aspartic acid substitution in the VPg domain that abolished the interaction with eIF(iso)4E. After 20 days, plants bombarded with p35Tunos showed viral symptoms, while plants bombarded with p35TuD77N remained symptomless. These results suggest that VPg-eIF(iso)4E interaction is a critical element for virus production.

Amino Acid Sequence↗
PubMed1996

Complications associated with therapeutic neck radiation.

PURPOSE: This retrospective study of patients who underwent neck radiation as part of their treatment for squamous cell carcinoma of the oral cavity sought to identify and quantify the morbidity associated with this treatment. PATIENTS AND METHODS: Thirty-five patients who received neck radiation between 1985 and 1992 were randomly recalled for examination. All patients had been treated in a standardized fashion by the Department of Radiation Oncology. The long-term effects of neck radiation on skin changes, thyroid function, and neck range of motion, of atherosclerotic carotid artery disease, xerostomia, and glottic structures were measured. RESULTS: Fifty-seven percent of patients demonstrated grade 1 skin changes. No severe changes were noted, and no development of secondary neoplasia was observed. There was no linear trend observed between radiation dose and skin changes. Hypothyroidism developed in 14.3% of patients within 3.5 years posttreatment. Logistic regression demonstrated a significant association between hypothyroidism and radiation dose. Limitation of neck mobility was the most significant complication with deficits demonstrated in all ranges of motion. Carotid bruits were documented in 14.3% of patients, with a significant association between the higher neck dosage in N+ cases. Xerostomia was found in 68% of patients. There was persistent glottic erythema in 11.4% of patients. CONCLUSIONS: The results of this study indicate that there are persistent complications after neck radiation, which include limitation of neck movement, diminished thyroid function, accelerated carotid artery narrowing, and skin and salivary changes.

Carcinoma, Squamous Cell↗
PubMed1992

Laser and daunomycin chemophototherapy of human carcinoma cells.

Adriamycin and daunomycin anticancer drugs are detectable in leukemias and solid tumors by cell fluorescence. We observed initial cytoplasmic fluorescence followed by slow nuclear localization of adriamycin and daunomycin after incubation with cultured human squamous cell (P3, FADU) and adenocarcinoma (HT29, SW620) lines by digital video imaging microscopy. Tumor cells incubated with 10 mug/ml of these drugs exhibited increased uptake for more than 3 h with intracellular levels in the range 0.5-2.5 mug/10 6 cells measured by dimethyl sulfoxide (DMSO) extraction and fluorescence spectrophotometry. Daunomycin had 10- to 100-fold higher toxicity for these carcinoma cells than for normal human epithelial keratinocytes measured by in vitro MTT tetrazolium assays. The viability of daunomycin-sensitized carcinoma cells was decreased 2- to 10-fold further by argon laser illumination at 488 nm (5W, T max = 8 degrees C) for 2-3 minutes. The results suggest that adriamycin derivatives may be useful targeting agents for adjuvant treatment and chemophototherapy of human solid tumors by MR-guided laser fiberoptic endoscopy.

Adenocarcinoma↗
PubMed1991

Pharmacokinetics of oral diltiazem and five of its metabolites in patients with chronic renal failure.

The pharmacokinetics of oral diltiazem were studied in 10 patients with chronic renal failure not requiring dialysis and in five healthy volunteers after a single dose of 120 mg. We found that patients with chronic renal failure had lower amounts of unchanged diltiazem and of its main metabolite (MA) in urine and a trend to have slightly higher values of plasma concentration. Since the terminal elimination phase is not affected by chronic renal failure we conclude that this trend is probably the result of alterations in the volume of distribution of diltiazem in these patients.

Administration, Oral↗
PubMed1991

Pharmacokinetics of intravenous diltiazem and five of its metabolites in patients with chronic renal failure and in healthy volunteers.

The pharmacokinetics of diltiazem were studied in seven patients with chronic renal failure (CRF) not requiring dialysis and in three healthy volunteers after a rapid i.v. infusion of 20 mg. Mean plasma concentrations at the end of infusion were 3.15 times higher in patients with CRF than in healthy volunteers. From 0.5 to 12 h post-infusion, the difference remained between 25 per cent and 73 per cent. Mean AUC0-infinity was statistically greater in patients than in volunteers while mean V area, CLtot, and CLren were statistically lower. The t1/2 alpha and t1/2 beta values were not significantly (p greater than 0.05) different between patients and volunteers. Renal excretion was statistically more important in volunteers (6.6 per cent of the dose) than in patients (1.2 per cent of the dose). We therefore conclude that CRF does not influence t1/2 beta of diltiazem but it interferes with the extent and possibly the rate of its extravascular distribution. That could result in transient high plasma concentrations after rapid i.v. infusion.

Adult↗
PubMed1990

Randomized controlled trial of tissue plasminogen activator in proximal deep venous thrombosis.

PURPOSE: To compare the efficacy and safety of recombinant human tissue-type plasminogen activator (rt-PA, supplied as Activase) with heparin alone or rt-PA plus heparin in the treatment of venographically documented proximal deep venous thrombosis (DVT) of the leg. PATIENTS AND METHODS: Sixty-four patients underwent 65 randomizations to rt-PA alone (n = 36), rt-PA plus heparin (n = 17), or heparin alone (n = 12) in a prospective, multicenter, randomized, open-label trial, with efficacy assessed by a radiology panel unaware of treatment assignment. Patients randomly assigned to rt-PA received 0.05 mg/kg/hour for 24 hours via a peripheral vein, with a maximum dose of 150 mg. All patients then received heparin and warfarin for the remainder of the hospitalization. Follow-up venography was performed 24 to 36 hours after initiation of therapy. RESULTS: Complete or more than 50% lysis occurred in 10 (28%) patients treated with rt-PA, five (29%) patients with rt-PA plus heparin, and no patient treated with heparin. No lysis occurred in 16 (44%) patients treated with rt-PA plus heparin, and 10 (83%) patients who received heparin alone (p = 0.04). There was one major complication, a nonfatal intracranial hemorrhage in a patient who received rt-PA alone. At 7 to 10 days after initiation of treatment, the level of serum glutamic oxaloacetic transaminase nearly doubled among all patients, including those assigned to receive heparin alone. CONCLUSION: (1) rt-PA and rt-PA plus heparin cause more clot lysis than heparin alone; (2) the addition of heparin to rt-PA does not improve the lysis rate; (3) DVT treated with heparin is commonly associated with a rise in the transaminase level; (4) heparin does not increase the risk of bleeding from rt-PA therapy; and (5) alternative dosing regimens and modes of administration of rt-PA should be investigated to improve further its efficacy and safety in the treatment of acute DVT.

Adolescent↗
PubMedDate not supplied

Microvascular surgery in the posterior fossa: nursing diagnoses.

Posterior fossa revascularization is a new surgical technique to supply bypassed blood flow past stenoses in the vertebral and basilar arteries. Comprehensive cardiovascular assessment and management by the critical care nurse promotes euvolemia and slight hypertension, which optimizes blood flow through the anastomosis. The authors describe the critical care nursing techniques for the potential nursing diagnoses for these patients.

Cerebral Revascularization↗
PubMedDate not supplied

Expanding the nurse's role through formal assessment of the neonate.

At Medical Center Hospital of Vermont a program was designed and implemented to expand the nurse's role through formal assessment and documentation of the neonate. Assessment criteria from NAACOG's Obstetric, Gynecologic, and Neonatal Nursing Functions and Standards were used to develop new Newborn Nursery Standards. The staff prepared for the expanded role through inservice programs that were videotaped for future orientation of new staff members. Over one year after implementation of the new standards, the nursing staff is functioning easily in its expanded role.

Humans↗