Variability of platelet aggregate dispersal with glycoprotein IIb-IIIa antagonists eptifibatide and abciximab.

BACKGROUND: Utilization of glycoprotein IIb-IIIa (GPIIb-IIIa) inhibitors improves outcomes of patients with acute coronary syndromes (ACS), including those undergoing percutaneous coronary intervention (PCI). These results may be related to the ability of the inhibitors to destabilize coronary thrombi, reduce microembolization, and restore vessel patency. OBJECTIVE: To evaluate in vitro the ability of GPIIb-IIIa antagonists, abciximab and eptifibatide, to promote the disaggregation of platelet-rich thrombus. METHODS: Antagonist-induced disaggregation was assayed in plasma by aggregometry, as well as in whole blood by point of care and capillary perfusion systems. Fibrinogen dissociation from the platelet surface was quantified by flow cytometry. RESULTS: Significant disaggregation of 5 microm ADP-induced aggregates was observed after addition of either agent. The maximum extent and rate of disaggregation were significantly higher with eptifibatide than with abciximab. Both antagonists also dispersed 2 microg mL(-1) collagen-induced aggregates, again with eptifibatide having a greater effect. Eptifibatide, but not abciximab (up to 10 microg mL(-1)), was efficient at dissociating aggregates to single platelets in whole blood and dispersing aggregates that had been aged for 30 min before treatment. Eptifibatide also reduced existing thrombus burden in the perfusion model under arterial flow conditions. A key mechanism of aggregate dispersal was antagonist-induced displacement of platelet-bound fibrinogen, which was greater with eptifibatide, a competitive inhibitor of fibrinogen binding, than with the noncompetitive inhibitor, abciximab. CONCLUSIONS: These results suggest that drug concentration and residence time, along with thrombus extent and age, may be critical determinants in promoting timely recanalization.

Factors Influencing Airborne Conidial Concentrations of Alternaria panax in Cultivated American Ginseng Gardens.

Leaf blight, caused by Alternaria panax, is the most common disease of cultivated ginseng and is an annual threat. To determine the influence of weather parameters on airborne conidial concentrations (ACCs), 3- and 4-year-old commercial American ginseng (Panax quinquefolium) gardens were monitored from mid-May to September for two growing seasons. Hourly concentrations of airborne A. panax conidia were enumerated using a Burkard volumetric spore sampler. The hourly averages of air temperature, rainfall, leaf wetness, and relative humidity were also collected. Fungicides were not applied. The incidence of leaf blight was assessed in predetermined areas of the monitored gardens. Disease pressure from A. panax was high in 2005 and 2006 and resulted in crop defoliation. Each year, ACCs were detected beginning in late May and continued through the growing season. Daily conidial concentrations followed a diurnal pattern and were greatest during periods of rapidly decreasing relative humidity. Relative humidity was negatively correlated to hourly ACCs. Each year, hourly ACCs were negatively correlated to leaf wetness and rainfall. A positive correlation was detected for hourly ACCs following 16 h or more of rainfall. A significant correlation was observed between hourly ACCs and temperature.

Evaluation of TOM-CAST in Timing Fungicide Sprays for Management of Alternaria Blight on American Ginseng.

Alternaria panax incites blighting of the foliage, peduncles, and drupes of cultivated American ginseng (Panax quinquefolium). A disease forecaster (TOM-CAST), originally developed to predict leaf blight caused by A. solani on tomato, was evaluated for management of A. panax in commercial ginseng gardens. For 3 years, fungicide sprays initiated by TOM-CAST (using 10 and 15 disease severity value thresholds) were compared with sprays applied at 7- and 10-day intervals. Three fungicide programs were evaluated: (i) chlorothalonil alone, (ii) chlorothalonil alternated with pyraclostrobin, and (iii) copper hydroxide alternated with pyraclostrobin. As many as 10 fewer fungicide applications were made when using TOM-CAST or the 10-day programs. Although select TOM-CAST treatment programs were comparable with the 7-day schedule in limiting foliar disease, only the 7-day applications adequately protected drupe and seed yield. Both A. panax and A. alternata were recovered from drupe tissues and seed coats. Only A. alternata was recovered from endosperm halves. Ginseng seed yield and quality is an important consideration when assessing fungicide programs.

First Report of Mefenoxam Sensitivity and Pathogenicity of Phytophthora citricola Isolated from American Ginseng (Panax quinquefolium).

In March of 2004, stratified ginseng seeds from commercial Wisconsin gardens were planted in sterilized silica sand in a research greenhouse at Michigan State University. Following emergence, seedlings exhibiting wilting, damping off, and black stem lesions were observed. In the laboratory, symptomatic seedlings were rinsed with distilled water. Tissue samples were excised and embedded in water agar amended with ampicillin (100 mg/liter) and incubated at 25°C. In addition to the isolation of Phytophthora cactorum, a known pathogen of ginseng, P. citricola, (five isolates) also was identified from single-zoospore cultures based on morphology (2). One-week-old, dilute V8 agar cultures were used to obtain single zoospores. Cultures were flooded with 20 ml of sterilized distilled water chilled to 10°C and incubated at 25°C for 25 min to induce zoospore release. Zoospore suspensions were spread onto water agar plates, and after 24 h at 25°C, single germinating zoospores were selected at random and transferred to benomyl, ampicillin, rifampicin, and pentachloronitrobenzene (BARP)-amended V8 agar plates. Sequence analysis of the internal transcribed spacer (ITS) region 1 and 2 of the rDNA was also used to distinguish P. citricola from P. cactorum. A representative sequence for the isolates of P. citricola (NCBI Accession No. FJ217388) matched (100% similarity) a P. citricola isolate deposited in GenBank (Accession No. DQ486661). To screen P. citricola for in vitro response to mefenoxam, agar plugs (7-mm diameter) from 1-week-old V8 agar cultures incubated at 25°C under fluorescent lighting were placed in the center of each of two V8 agar plates amended with 0 and 100 ppm of mefenoxam (Ridomil Gold EC, 48% a.i., suspended in sterile distilled water and added to V8 agar cooled to 49°C). The plates were incubated at 25°C for 3 days under fluorescent lighting. Isolates were assigned a mefenoxam sensitivity rating based on the percentage of radial mycelial growth on the amended V8 agar when compared with the unamended control. Each of the five isolates was scored as mefenoxam resistant with growth on 100-ppm plates >30% of the controls. Koch's postulates were conducted for the isolates of P. citricola recovered from ginseng seedlings to confirm pathogenicity. Previously, P. citricola was reported as nonpathogenic to ginseng (1). Three-week-old, healthy ginseng seedlings were planted into 89- × 64-mm pots filled with autoclaved medium-particle vermiculite and maintained in the greenhouse under 63% shade cloth with temperatures between 18 and 26°C. Pots were arranged in a completely randomized block design with eight seedlings per isolate as replicates and watered as needed. A 2-ml inoculum suspension (approximately 104 zoospores) was injected into the potting medium at the stem base of each seedling. All of the isolates were pathogenic to ginseng seedlings with 60% of inoculated seedlings per isolate exhibiting wilting, damping off, and blackened stems within 3 weeks after inoculation. P. citricola was reisolated from all inoculated plants. To our knowledge, this is the first report of P. citricola pathogenic on ginseng. References: (1) T. W. Darmono et al. Plant Dis. 75:610, 1991. (2) D. C. Erwin and O. K. Ribeiro. Page 96 in: Phytophthora Diseases Worldwide. The American Phytopathological Society, St. Paul, MN. 1996.

Virulence and Fungicide Sensitivity of Phytophthora cactorum Isolated from American Ginseng Gardens in Wisconsin and Michigan.

Phytophthora cactorum causes foliar blight and root rot on cultivated ginseng (Panax quinquefolium). Commercial ginseng gardens in Wisconsin and Michigan and research gardens at Michigan State University were sampled and P. cactorum isolated. In all, 114 and 96 P. cactorum isolates were recovered in 2003 and 2004, respectively. The majority (82%) of the isolates screened (210 in total) were resistant to the fungicide mefenoxam. P. cactorum isolates were screened for pathogenicity using 'McIntosh' apple fruit (206 isolates) and ginseng seedlings (38 isolates). Most isolates (98%) produced necrotic lesions on apple fruit and nearly all (97%) isolates resulted in 40 to 100% plant death. Apple fruit and ginseng seedlings were also used to test fungicide efficacy against P. cactorum. Mefenoxam, the industry standard, was ineffective in both the apple fruit and seedling studies when using a mefenoxam-resistant P. cactorum isolate. Only copper hydroxide provided consistent control against P. cactorum when tested on apple fruit and ginseng seedlings.

Covert inhalation of tablet causing fatal pneumonia.

Inhalation of foreign bodies is usually associated with acute respiratory symptoms. We report a case of an elderly woman who died from pneumonia due to covert tablet inhalation. Clinicians caring for the elderly should consider this as a possible cause for pneumonia which fails to respond to usual therapy.

Nursing the immobile: a preliminary study.

Permanent loss of mobility has profound physical and mental consequences for both sufferers and carers, and is a major challenge to the National Health Service. A recent study has shown that 42% of beds in departments of Geriatric Medicine are occupied by people with longstanding immobility. These people are highly dependent on nursing staff for their daily activities and quality of life. The assessment of mobility, as a single parameter of dependency, and the measurement of allocated nursing hours are both rapidly and easily performed on geriatric wards. It is felt that a simple correlation of these two variables might highlight areas where more detailed audit is desirable. This study demonstrates that the more immobile patients on a ward, the less the hours allocated to Registered and Learner grade nurses. Some possible reasons for this are suggested and the effects of this deployment on nursing practice and staff recruitment are discussed. It is felt that provision of appropriate nursing care to the most dependent patients in continuing care areas is essential, and that high levels of trained staff are needed to ensure this.

The bedfast.

Many geriatric beds are occupied by bedfast patients. Most were immobile from the time of admission and many were admitted from other hospital departments or residential care. More are discharged home than remain in hospital or are transferred to any other institution. Although a small minority of admissions become long-term bedfast inpatients this group require a disproportionate resource commitment. Reduction in the number of bedfast inpatients is more likely to be effected by changes in unit policy than by improvement in clinical practice.