Advantages and disadvantages of a rapid method to train drug discrimination.
Male; Animals; Rats; Drug Tolerance; Methods; Discrimination Learning/*drug effects; Amphetamines/*pharmacology; Dose-Response Relationship; Drug; 3; N-Methyl-3; 4-methylenedioxyamphetamine; 4-Methylenedioxyamphetamine/analogs & derivatives/*pharmacology
In an effort to reduce the often extensive period of time needed to train rats to discriminate between a drugged and nondrugged state, a fast training regimen was employed with 1.5 mg/kg 3,4-methylenedioxymethamphetamine (MDMA) used as the training drug in ten rats. This protocol consisted of one to three training sessions per day and it was compared to the more conventional method of once-per-day training in an equal number of rats. Results indicate that the fast-trained rats learned the discrimination in significantly fewer sessions than the slowly-trained rats. However, the subsequent dose-response experiments indicate that when the fast-trained rats are tested with various doses of MDMA, without prior vehicle treatment, their sensitivity to the drug is less than that of the slowly-trained rats. When a vehicle session is presented prior to drug dose-response testing, both groups perform similarly. It appears that the preceding vehicle sessions function as a reference point for the fast-trained rats and, although the more rapid training regimen allows for faster learning, these treatment regimens should be employed with caution when subsequent dose-response tests and generalization tests with other drugs are conducted.
Schechter M D
Pharmacology, biochemistry, and behavior
1988
1988-09
Article information provided for research and reference use only. All rights are retained by the journal listed under publisher and/or the creator(s).
<a href="http://doi.org/10.1016/0091-3057(88)90340-1" target="_blank" rel="noreferrer noopener">10.1016/0091-3057(88)90340-1</a>
Calculation of the reflection coefficient from measurements of endogenous vascular indicators.
Animals; Blood Proteins/*analysis; Blood Volume; Capillary Permeability; Filtration; Humans; Mathematics; Methods; Models; Theoretical
The solvent drag reflection coefficient (sigma) for total proteins can be estimated by comparing the relative degrees of concentration of erythrocytes and plasma proteins that occur during fluid filtration in an isolated perfused organ. In this analysis, we evaluated the accuracy of equations proposed by Pilati and Maron [Am. J. Physiol. 247 (Heart Circ. Physiol. 16): H1-H7, 1984] and Wolf et al. [Am. J. Physiol. 253 (Heart Circ. Physiol. 22): H194-H204, 1987] to calculate sigma from these concentration changes. We calculated sigma with each equation using data generated from a mathematical model of fluid and solute flux in membranes with known sigma's. We found that the equation of Wolf et al. provided the closest approximation to the true sigma over the entire range of filtration fractions tested (0.1-0.6), with the differences between the two equations increasing with filtration fraction. At low filtration fractions, the difference in sigma obtained using either approach was found to be inconsequential. At larger filtration fractions, a closer approximation of the true sigma can be obtained using the equation of Wolf et al.
Maron M B; Pilati C F
Journal of applied physiology (Bethesda, Md. : 1985)
1988
1988-04
Article information provided for research and reference use only. All rights are retained by the journal listed under publisher and/or the creator(s).
<a href="http://doi.org/10.1152/jappl.1988.64.4.1746" target="_blank" rel="noreferrer noopener">10.1152/jappl.1988.64.4.1746</a>
Analysis of connective tissues by laser capture microdissection and reverse transcriptase-polymerase chain reaction.
*Microdissection; Animals; Cell Separation/*methods; Chondrocytes/chemistry/cytology; Connective Tissue Cells/chemistry/*cytology; Gene Expression Profiling/*methods; Growth Plate/cytology; Inbred Strains; Lasers; Messenger/analysis/*isolation & purification; Methods; Mice; Newborn; Reverse Transcriptase Polymerase Chain Reaction; RNA; Tibia/cytology
Studies of gene expression from bone, cartilage, and other tissues are complicated by the fact that their RNA, collected and pooled for analysis, often represents a wide variety of composite cells distinct in individual phenotype, age, and state of maturation. Laser capture microdissection (LCM) is a technique that allows specific cells to be isolated according to their phenotype, condition, or other marker from within such heterogeneity. As a result, this approach can yield RNA that is particular to a subset of cells comprising the total cell population of the tissue. This study reports the application of LCM to the gene expression analysis of the cartilaginous epiphyseal growth plate of normal newborn mice. The methodology utilized for this purpose has been coupled with real-time quantitative reverse transcriptase-polymerase chain reaction (QRT-PCR) to quantitate the expression of certain genes involved in growth plate development and calcification. In this paper, the approaches used for isolating and purifying RNA from phenotypically specific chondrocyte populations of the murine growth plate are detailed and illustrate and compare both qualitative and quantitative RT-PCR results. The technique will hopefully serve as a guide for the further analysis of this and other connective tissues by LCM and RT-PCR.
Jacquet Robin; Hillyer Jennifer; Landis William J
Analytical biochemistry
2005
2005-02
Article information provided for research and reference use only. All rights are retained by the journal listed under publisher and/or the creator(s).
<a href="http://doi.org/10.1016/j.ab.2004.09.033" target="_blank" rel="noreferrer noopener">10.1016/j.ab.2004.09.033</a>
Gastroschisis: an 18-year review.
Abdominal Muscles/*abnormalities/surgery; Abnormalities; Cesarean Section; Congenital Abnormalities/surgery; Female; Humans; Infant; Male; Methods; Multiple; Newborn; Postoperative Complications; Retrospective Studies
From 1972 to 1990, 69 cases of gastroschisis were treated at Akron Children's Hospital Medical Center. Eighty-one percent of these patients underwent primary closure of their abdominal wall defect. Thirteen of 69 patients (19%) required Silastic silos with final closure in an average of 7.8 days. There was no sex predilection, the average birth weight was 2,473 g, and the mean gestational age was 36.3 weeks. Twenty-six percent had associated anomalies, the majority were intestinal atresia, volvulus, and/or undescended testicles. Seventy-seven percent of the infants were delivered vaginally. Fourteen children were delivered via cesarean section. Seven cesarean sections were done solely for prenatal ultrasonic identification of an abdominal wall defect. There was no improvement in hospital stay, complications, days until enteral feeds were tolerated, days intubated, or number of surgical procedures in this group. In 14 patients, mesh sheeting (Marlex, Silastic) was used in the final closure. Sixty-four percent of these incurred wound breakdown necessitating removal of the mesh. This compares with a 3.2% wound breakdown in the nonmesh group. The average hospital stay was 43.9 days and the average time to enteral feeds 20.2 days. Sixty-four percent of the patients required postoperative intubation for an average of 5.5 days. The overall mortality rate was 4.3%. The present data do not support gastroschisis alone as an indication for cesarean section. The data indicate that mesh be avoided in the final closure if possible and support a favorable prognosis for most babies.
Novotny D A; Klein R L; Boeckman C R
Journal of pediatric surgery
1993
1993-05
Article information provided for research and reference use only. All rights are retained by the journal listed under publisher and/or the creator(s).
<a href="http://doi.org/10.1016/0022-3468(93)90022-d" target="_blank" rel="noreferrer noopener">10.1016/0022-3468(93)90022-d</a>