Patients (pts) with solid tumors or lymphoproliferative malignancies (lympho) have similar dose response to darbepoetin alfa

2002 ◽  
Vol 38 (11) ◽  
pp. S132
Author(s):  
J Glaspy
2008 ◽  
Vol 52 (8) ◽  
pp. 2797-2805 ◽  
Author(s):  
Sandrine Lemaire ◽  
Aurélie Olivier ◽  
Françoise Van Bambeke ◽  
Paul M. Tulkens ◽  
Peter C. Appelbaum ◽  
...  

ABSTRACT Staphylococcus aureus invades eukaryotic cells. When methicillin-resistant S. aureus (MRSA) ATCC 33591 is phagocytized by human THP-1 macrophages, complete restoration of susceptibility to cloxacillin and meropenem is shown and the strain becomes indistinguishable from MSSA ATCC 25923 due to the acid pH prevailing in phagolysosomes (S. Lemaire et al., Antimicrob. Agents Chemother. 51:1627-1632, 2007). We examined whether this observation can be extended to (i) strains of current clinical and epidemiological interest (three hospital-acquired MRSA [HA-MRSA] strains, two community-acquired MRSA [CA-MRSA] strains, two HA-MRSA strains with the vancomycin-intermediate phenotype, one HA-MRSA strain with the vancomycin-resistant phenotype, and one animal [porcine] MRSA strain), (ii) activated THP-1 cells and nonprofessional phagocytes (keratinocytes, Calu-3 bronchial epithelial cells), and (iii) other β-lactams (imipenem, oxacillin, cefuroxime, cefepime). All strains showed (i) a marked reduction in MICs in broth at pH 5.5 compared with the MIC at pH 7.4 and (ii) sigmoidal dose-response curves with cloxacillin (0.01× to 100× MIC, 24 h of incubation) after phagocytosis by THP-1 macrophages that were indistinguishable from each other and from the dose-response curve for methicillin-susceptible S. aureus (MSSA) ATCC 25923 (relative potency [50% effect], 6.09× MIC [95% confidence interval {CI}, 4.50 to 8.25]; relative efficacy [change in bacterial counts over the original inoculum for an infinitely large cloxacillin concentration, or maximal effect], −0.69 log CFU [95% CI, −0.79 to −0.58]). Similar dose-response curves for cloxacillin were also observed with MSSA ATCC 25923 and MRSA ATCC 33591 after phagocytosis by activated THP-1 macrophages, keratinocytes, and Calu-3 cells. By contrast, there was a lower level of restoration of susceptibility of MRSA ATCC 33591 to cefuroxime and cefepime after phagocytosis by THP-1 macrophages, even when the data were normalized for differences in MICs. We conclude that the restoration of MRSA susceptibility to β-lactams after phagocytosis is independent of the strain and the types of cells but varies between β-lactams.


1980 ◽  
Vol 190 (2) ◽  
pp. 333-339 ◽  
Author(s):  
M C W Minchin

1. Protoveratrine A increased the release of gamma-amino[3H]butyrate from small slices of rat cerebral cortex. This effect increased with increasing protoveratrine concentration, reaching a maximum at 100 microM. 2. Removal of Ca2+ from the superfusing medium did not change the increase in release due to 10 microM-protoveratrine; however, the Ca2+ antagonists, compound D-600, La3+, Mn2+, Mg2+ and also high Ca2+ concentration inhibited the effect of the alkaloid, as did procaine. 3. Protoveratrine A increased the uptake of 22Na+ into the slices with a similar dose-response curve to that found for gamma-aminobutyrate release. For the most part, the substances that inhibited protoveratrine-stimulated gamma-aminobutyrate release also inhibited 22Na+ uptake, although the correlation was not perfect. 4. Although extracellular Ca2+ is not required for protoveratrine-induced gamma-aminobutyrate release, an increase in Na+ influx that is susceptible to inhibition by some Ca2+ antagonists does appear to be associated with this phenomenon. However, the possibility remains that changes in the free intracellular Ca2+ concentration may be important for transmitter release induced by depolarizing veratrum alkaloids.


2007 ◽  
Vol 49 (6) ◽  
pp. 337-345 ◽  
Author(s):  
John E Baker ◽  
Deborah Kozik ◽  
Anna K Hsu ◽  
Xiangping Fu ◽  
James S Tweddell ◽  
...  

2009 ◽  
Vol 7 (2) ◽  
pp. 197
Author(s):  
A. Bustos ◽  
F. Carabantes ◽  
R. Álvarez ◽  
N. Díaz ◽  
P. Bueso ◽  
...  

1999 ◽  
Vol 89 (10) ◽  
pp. 974-980 ◽  
Author(s):  
K. B. Johnson ◽  
J. A. DiLeone

The crown gall pathosystem was used to evaluate a model that describes the dose-response relationship between biological control agents and plant pathogens. The model predicts that this relationship can become asymptotic, such that increased antagonist doses cannot compensate for deficiencies in disease suppression. Wounded roots of tomato (Lycopersicon esculentum) and cherry (Prunus mahaleb) plants were dipped into different concentrations of the biological control organism Agrobacterium radiobacter strain K84 prior to inoculation with the pathogen A. tumefaciens. Pathogen strains sensitive or resistant to the antibiotic agrocin 84 were used, and for tomato experiments, a derivative of A. radiobacter strain K84 that does not produce agrocin 84 also was included as an experimental treatment. As predicted by the dose-response model, the amount of disease suppression per unit of antagonist decreased with increasing antagonist dose and became asymptotic at high antagonist densities. Control of crown gall of tomato was nearly complete with the combination of A. radiobacter K84 and an agrocin 84-sensitive strain of A. tumefaciens. Pathogen resistance to agrocin 84 or lack of agrocin 84 production by A. radiobacter resulted in antagonist dose-crown gall incidence relationships that were apparently asymptotic at levels of control significantly less than 100%. For field-grown cherry, similar dose-response relationships were observed with higher asymptotic levels of disease suppression obtained when trees were inoculated with an agrocin 84-sensitive A. tumefaciens strain compared with an agrocin 84-resistant pathogen strain. The differences among bacterial strain combinations in the magnitude of the asymptote defined by the dose-response relationships suggest that A. radiobacter impacts a smaller proportion of the pathogen population when the activity of agrocin 84 is muted.


Blood ◽  
2005 ◽  
Vol 106 (11) ◽  
pp. 3767-3767 ◽  
Author(s):  
Ralph Vincent Boccia ◽  
Peter T. Silberstein ◽  
Simon Tchekmedyian ◽  
Dianne Tomita ◽  
Greg Rossi ◽  
...  

Abstract Patients (pts) with cancer receiving chemotherapy commonly have chemotherapy-induced anemia (CIA), often resulting in reduced quality of life. The primary objective of this analysis was to summarize the effectiveness of darbepoetin alfa (DA) administered at 300mcg every 3 weeks (Q3W), in achieving and maintaining a hemoglobin (Hb) target range of 11–13g/dL in pts with hematologic malignancies and CIA, versus pts with solid tumors and CIA. Data for all 1493 pts enrolled in this multicenter, open-label, 16-week study who received at least one dose of DA are included in this exploratory analysis stratified by tumor type. Pts ≥18 years of age receiving multicycle chemotherapy and with Hb <11g/dL were eligible for this study. Hb-based endpoints were adjusted for red blood cell transfusions and analyzed with and without imputing missing Hb values. Pt-reported outcomes were assessed using the Functional Assessment of Cancer Therapy-Fatigue (FACT-F) scale. Most pts were white (79%), 61% were female, and the median age was 64 years (range, 19 to 97). At baseline (BL), 31% of pts had Hb <10g/dL and 61% had Hb ≥10g/dL; the mean (SD) was 10.1 (0.7)g/dL. Hematologic malignancy (14%) was the third most common tumor type after breast (29%) and gastrointestinal (24%); 45% of the hematologic malignancies were non-Hodgkin’s lymphoma (NHL) pts. Hb, transfusion, and FACT-F endpoints are shown in the table. A slightly lower percent of NHL pts achieved the Hb target range recommended by current guidelines (11–13g/dL), compared to pts with other hematologic malignancies or with solid tumors. Similar proportions of pts with hematologic malignancies or solid tumors maintained Hb within the target range. The proportion of pts receiving RBC transfusions from week 5 to the end of study (EOS) was similar for pts with hematologic malignancies and for pts with solid tumors. Improvements in FACT-F scores were seen in all groups, although the mean change was lower in NHL pts compared with other tumor types. Serious adverse events were as expected for this patient population. DA Q3W appears to be effective in achieving and maintaining Hb between 11 to 13g/dL in pts with CIA and hematologic malignancies. Since chemotherapy is often administered Q3W, synchronizing DA treatment with pts’ chemotherapy schedules may simplify the treatment of CIA in these pts. Hematologic - NHL N=98 Hematologic - non-NHL N=118 Solid N=1277 All Tumor Types N=1493 *For pts who achieved target. **For pts available at day 29. K-M=Kaplan Meier. CL=confidence limits Mean (95%CL) BL Hb (g/dL) 10.1 (9.9, 10.2) 10.0 (9.8, 10.1) 10.1 (10.1, 10.2) 10.1 (10.1, 10.2) Pts who achieved ≥ Hb 11g/dL. Crude % (95% CL) 74 (66, 83) 82 (75, 89) 79 (77, 81) 79 (77, 81) Proportion of pts maintaining Hb between 11 and 13g/dL after achieving target - n (%)* 51 (70) 68 (70) 739 (73) 858 (73) Time to target Hb (weeks). K-M Median (95% CL) 7 (6, 8) 6 (4, 7) 4 (4, 5) 4 (4, 5) Transfusions from week 5 to EOS. Crude % (95% CL)** 21 (13, 30) 20 (13, 27) 18 (16, 20) 18 (16, 20) Mean change in FACT-F from BL to week 16 (95% CL) 2.8 (−0.9, 6.5) 5.2 (1.8, 8.6) 4.8 (3.9, 5.7) 4.7 (3.9, 5.6)


Author(s):  
Han ◽  
Liu ◽  
Gong ◽  
Ye ◽  
Zhou

Previous studies have suggested an association between secondhand smoke (SHS) exposure and risk of depressive symptoms. However, it remains unclear whether there is a dose–response relationship. The effect estimates were pooled using fixed-effect or random-effect models based on homogeneity analysis. The dose–response meta-analysis was performed by linear and non-linear regression. Subgroup analyses were conducted to explore the possible sources of heterogeneity. Twenty-four studies were included in this meta-analysis. SHS exposure was significantly associated with increased odds of depressive symptoms (odds ratio (OR) = 1.32, 95% confidence interval (CI) 1.25–1.39). For SHS exposure expressed as an ordinal variable, the dose–response meta-analysis revealed a monotonically increasing relationship between SHS exposure and depressive symptoms. A similar dose–response relationship was observed for SHS exposure expressed as a continuous variable (OR = 1.57, 95% CI = 1.26–1.87). Our findings suggest that SHS exposure is associated with increasing odds of depressive symptoms in a dose–response manner.


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