Dose-Response and Time-Course Characteristics of UV-A1 Erythema

The current study evaluated both the time course of insulin resistance associated with feeding dogs a high-fat diet and the relationship between the development of insulin resistance and the increase in blood pressure that also occurs. Twelve adult mongrel dogs were chronically instrumented and randomly assigned to either a control diet group (n = 4) or a high-fat diet group (n = 8). Insulin resistance was assessed by a weekly, single-dose (2 mU.kg-1.min-1) euglycemic-hyperinsulinemic clamp on all dogs. Feeding dogs a high-fat diet was associated with a 3.7 +/- 0.5 kg increase in body weight, a 20 +/- 4 mmHg increase in mean blood pressure, a reduction in insulin-mediated glucose uptake [(in mumol-kg-1.min-1) decreasing from 72 +/- 6 before to 49 +/- 7 at 1 wk, 29 +/- 3 at 3 wk, and 30 +/- 2 at 6 wk of the high-fat diet, P < 0.01]. and a reduced insulin-mediated increase in cardiac output. In eight dogs (4 high fat and 4 control), the dose-response relationship of insulin-induced glucose uptake also was studied. The whole body glucose uptake dose-response curve was shifted to the right, and the rate of maximal whole body glucose uptake was significantly decreased (P < 0.001). Finally, we observed a direct relationship between the high-fat diet-induced weekly increase in mean arterial pressure and the degree to which insulin resistance developed. In summary, the current study documents that feeding dogs a high-fat diet causes the rapid development of insulin resistance that is the result of both a reduced sensitivity and a reduced responsiveness to insulin.

Download Full-text

rhIGF-I Enhances Functional Recovery from Sciatic Crush Time-Course and Dose-Response Study

Annals of the New York Academy of Sciences ◽

10.1111/j.1749-6632.1993.tb26245.x ◽

1993 ◽

Vol 692 (1 The Role of I) ◽

pp. 314-316 ◽

Cited By ~ 10

Author(s):

PATRICIA C. CONTRERAS ◽

CATHY STEFFLER ◽

JEFFRY L. VAUGHT

Keyword(s):

Functional Recovery ◽

Dose Response ◽

Time Course ◽

Dose Response Study

Download Full-text

Rat uterine microbiochemistry: metabolic enzyme activities stimulated by 17-beta-estradiol are localized in epithelial cells.

Journal of Histochemistry & Cytochemistry ◽

10.1177/35.6.3571958 ◽

1987 ◽

Vol 35 (6) ◽

pp. 657-662 ◽

Cited By ~ 2

Author(s):

J P Holt ◽

E Rhe

Keyword(s):

Enzyme Activity ◽

Smooth Muscle ◽

Epithelial Cells ◽

Dose Response ◽

Enzyme Activities ◽

Time Course ◽

Citrate Synthase ◽

Ovariectomized Rats ◽

Similar Response ◽

Estradiol Treatment

Lactate dehydrogenase (LDH; EC 1.1.1.27), citrate synthase (CS; EC 4.1.3.7), and beta-hydroxyacyl-CoA-dehydrogenase (beta-OH-acyl-CoA-DH; EC 1.1.1.35) activities were determined in each of the three major cell types of rat uterus, i.e., epithelial, stromal, and smooth muscle, using quantitative microanalytical techniques. Adult ovariectomized rats were treated with 17-beta-estradiol to determine the time course and dose response (0.025-50 micrograms/300-g rat) effect of estrogen on enzyme activity of each type of uterine cell. The use of "oil well" and enzyme-cycling microtechniques to determine the time course and the dose responses of enzyme activity changes required microassays involving 1595 microdissected single cell specimens. Estradiol treatment increased epithelial LDH, CS and beta-OH-acyl-CoA-DH activity but had no effect on these enzymes in the stroma or in smooth muscle cells. The estradiol-stimulated peak enzyme activities on Day 4 in the intervention group are compared with those in the ovariectomized rat controls as follows: LDH, 44.5 +/- 3.5 vs 22.3 +/- 3.9; CS, 3.5 +/- 0.2 vs 1.5 +/- 0.6; beta-OH-acyl-CoA-H, 3.5 +/- 0.32 vs 2.2 +/- 0.2 (mean +/- standard deviation; mol/kg/hr). Stromal cell activities (LDH, 7.4 +/- 1.0; CS, 1.2 +/- 0.2; beta-OH-acyl-CoA-DH, 0.9 +/- 0.1) were significantly lower than epithelial cell levels and were similar to smooth muscle levels. Therefore, even in the ovariectomized animal epithelial cells have markedly higher metabolic activity compared with adjacent cells. The enzyme activities are expressed as moles of substrate reacting per kilogram of dry weight per hour. All three enzymes exhibited a 17-beta-estradiol-induced dose response between 0.025-0.15 micrograms/300-g rat. The three enzymes studied all had similar response patterns to estrogen. The effect of estradiol was restricted to epithelial cells, with enzyme activities increasing to maximal levels after approximately 96 hr of hormone treatment. This study therefore not only confirms the specific and differential metabolic responses of uterine cells to estradiol treatment, but clearly demonstrates that marked metabolic differences exist between epithelial cells and stromal or smooth muscle uterine cells.

Download Full-text

Gene selection and clustering for time-course and dose-response microarray experiments using order-restricted inference

Bioinformatics ◽

10.1093/bioinformatics/btg093 ◽

2003 ◽

Vol 19 (7) ◽

pp. 834-841 ◽

Cited By ~ 136

Author(s):

S. D. Peddada ◽

E. K. Lobenhofer ◽

L. Li ◽

C. A. Afshari ◽

C. R. Weinberg ◽

...

Keyword(s):

Dose Response ◽

Time Course ◽

Gene Selection ◽

Order Restricted Inference ◽

Microarray Experiments ◽

Order Restricted

Download Full-text

Tolerance to self-administration of cocaine in rats: time course and dose-response determination using a multi-dose method

Drug and Alcohol Dependence ◽

10.1016/0376-8716(93)90089-9 ◽

1993 ◽

Vol 32 (3) ◽

pp. 247-256 ◽

Cited By ~ 44

Author(s):

M.W. Emmett-Oglesby ◽

R.L. Peltier ◽

R.Y. Depoortere ◽

C.L. Pickering ◽

M.L. Hooper ◽

...

Keyword(s):

Dose Response ◽

Time Course ◽

Self Administration ◽

Dose Method ◽

Response Determination

Download Full-text

Dose-response relationships and time course of the response to systemic beta adrenoreceptor agonists in infants with bronchopulmonary disease.

Thorax ◽

10.1136/thx.43.10.770 ◽

1988 ◽

Vol 43 (10) ◽

pp. 770-776 ◽

Cited By ~ 16

Author(s):

R Kraemer ◽

P Birrer ◽

M H Schoni

Keyword(s):

Dose Response ◽

Time Course

Download Full-text

Initial Inoculum and the Severity of COVID-19: A Mathematical Modeling Study of the Dose-Response of SARS-CoV-2 Infections

Epidemiologia ◽

10.3390/epidemiologia1010003 ◽

2020 ◽

Vol 1 (1) ◽

pp. 5-15

Author(s):

Baylor Fain ◽

Hana M. Dobrovolny

Keyword(s):

Dose Response ◽

Time Course ◽

Severe Disease ◽

Equation Model ◽

Viral Titer ◽

Response Curves ◽

Agent Based ◽

Initial Inoculum ◽

Peak Viral Load ◽

Titer Curve

SARS-CoV-2 (Severe acute respiratory syndrome coronavirus 2) causes a variety of responses in those who contract the virus, ranging from asymptomatic infections to acute respiratory failure and death. While there are likely multiple mechanisms triggering severe disease, one potential cause of severe disease is the size of the initial inoculum. For other respiratory diseases, larger initial doses lead to more severe outcomes. We investigate whether there is a similar link for SARS-CoV-2 infections using the combination of an agent-based model (ABM) and a partial differential equation model (PDM). We use the model to examine the viral time course for different sizes of initial inocula, generating dose-response curves for peak viral load, time of viral peak, viral growth rate, infection duration, and area under the viral titer curve. We find that large initial inocula lead to short infections, but with higher viral titer peaks; and that smaller initial inocula lower the viral titer peak, but make the infection last longer.

Download Full-text