Increased chondrocyte apoptosis in growth plates from children with slipped capital femoral epiphysis
apoptosis; Orthopedics; pathogenesis; Pediatrics; programmed cell-death; slipped capital femoral epiphysis; terminal hypertrophic chondrocytes
Ultrastructural studies of slipped capital femoral epiphysis (SCFE) growth plates have shown diminished cellularity and marked distortion of the architecture in the proliferative and hypertrophic zones. Chondrocyte degeneration and death were noted at all levels of the hypertrophic and proliferative zones, suggesting an accelerated disturbance in the life-to-death cycle of the chondrocytes. The current study examines the mechanism responsible for the diminished cell number and whether increased programmed cell death (apoptosis) or necrosis was operative. proximal femoral growth plates from patients with SCFE (three patients) were prepared and sectioned for histochemistry, in situ detection of apoptosis, and immunohistochemistry. The results showed that the diminished cell number is due to an abnormal frequency and distribution of chondrocytes undergoing apoptosis. Although it is unclear whether the increased apoptosis is occurring early or late in the disease, it is highly likely that it is directly linked to pathogenesis.
Adamczyk M J; Weiner D S; Nugent A; McBurney D; Horton W E
Journal of Pediatric Orthopaedics
2005
2005-07
Journal Article or Conference Abstract Publication
<a href="http://doi.org/10.1097/01.mph.0000165138.60991.mL" target="_blank" rel="noreferrer noopener">10.1097/01.mph.0000165138.60991.mL</a>
Paleontological and Developmental Evidence for the Origin of Baleen and the Loss of Teeth in Baleen Whales
Biochemistry & Molecular Biology; Cell Biology; Life Sciences & Biomedicine - Other; Topics
Thewissen J G M; Hieronymus T L; George J C; Suydam R; Stimmelmayr R; McBurney D
Faseb Journal
2017
2017-04
Journal Article
n/a
BAG-1 modulates endoplasmic reticulum stress in chondrocytes
Biochemistry & Molecular Biology; Cell Biology
Yang L; Carlson S G; McBurney D; Horton W E
Matrix Biology
2006
2006-11
Journal Article
<a href="http://doi.org/10.1016/j.matbio.2006.08.195" target="_blank" rel="noreferrer noopener">10.1016/j.matbio.2006.08.195</a>
Phentermine plus fenfluramine produce cocaine-like discriminative cues
analogs; cocaine; combinations; drug discrimination; fenfluramine; Pharmacology & Pharmacy; phentermine; receptors; Research & Experimental Medicine; serotonin; stimulus properties
Drug discrimination studies were conducted in six male Sprague-Dawley rats trained to discriminate the interoceptive cues produced by 10 mg/kg cocaine in an effort to investigate if there is stimulus generalization to phentermine or phentermine + fenfluramine. Once having reached criterion performance, these rats were tested with lower doses of cocaine and generated a typical dose-response curve allowing for calculation of an ED(50) value: 2.798 mg/kg. Testing of phentermine in doses of 1.25-5.0 mg/kg indicated generalization with the highest dose producing 80% cocaine-appropriate responding and allowing for an ED(50) value of 2.356 mg/kg. When the phentermine doses were tested in combination 2.0 mg/kg fenfluramine, however, there was an increase in the discriminability of the highest phentermine dose and a slight decrease in the ED(50) value of the combination. Thus, administration of phentermine + fenfluramine, having both dopamine-releasing and serotonin-releasing properties, respectively, may mimic the neurochemical activity by which cocaine acts in the central nervous system and may possibly allow for cocaine-like effects as these two drugs see increased use in obesity control.
Schechter M D; McBurney D
Life Sciences
1996
1996-10
Journal Article
<a href="http://doi.org/10.1016/s0024-3205(96)00513-9" target="_blank" rel="noreferrer noopener">10.1016/s0024-3205(96)00513-9</a>
Effect of repeated administrations upon cathinone discrimination and conditioned place preference.
Male; Animals; Rats; Psychotropic Drugs/*pharmacology; Discrimination (Psychology)/*drug effects; Alkaloids/*pharmacology; Drug Tolerance/physiology; Inbred Strains; Conditioning; Operant/*drug effects
1. Eight male rats were trained to discriminate the interoceptive cues produced by 0.8 mg/kg l-cathinone in a two-lever, food-motivated operant task and they were, subsequently, tested for preference to cathinone in a conditioned place preference (CPP)-test. 2. Once trained, the rats were placed on a 10 day regimen of twice-a-day non-contingent administrations of saline followed by a similar regimen of multiple injections of 0.8 mg/kg cathinone. 3. After each series of non-contingent administrations, the rats' ability to discriminate (0.2-0.8 mg/kg) cathinone, as well as their preference for it, was determined. 4. Results indicate that tolerance tends to develop to the effect of cathinone in its ability to control discriminative behavior as indicated by deficits in discriminative performance and a two-fold shift of the dose-response curve to the right. 5. In contrast, preference for cathinone, in the CPP-tests, was not significantly affected by the multiple cathinone administration regimen. 6. The possibility that tolerance to some behavioral effects may occur in habitual users of the cathinone-containing Khat shrub is discussed.
Schechter M D; McBurney D
General pharmacology
1991
1905-06
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/10.1016/0306-3623(91)90204-j" target="_blank" rel="noreferrer noopener">10.1016/0306-3623(91)90204-j</a>
Phentermine+fenfluramine produce cocaine-like discriminative cues.
*Discrimination (Psychology); Animals; Cocaine/*pharmacology; Dose-Response Relationship; Drug; Fenfluramine/administration & dosage/*pharmacology; Male; Phentermine/administration & dosage/*pharmacology; Rats; Sprague-Dawley
Drug discrimination studies were conducted in six male Sprague-Dawley rats trained to discriminate the interoceptive cues produced by 10 mg/kg cocaine in an effort to investigate if there is stimulus generalization to phentermine or phentermine + fenfluramine. Once having reached criterion performance, these rats were tested with lower doses of cocaine and generated a typical dose-response curve allowing for calculation of an ED50 value: 2.798 mg/kg. Testing of phentermine in doses of 1.25-5.0 mg/kg indicated generalization with the highest dose producing 80% cocaine-appropriate responding and allowing for an ED50 value of 2.356 mg/kg. When the phentermine doses were tested in combination 2.0 mg/kg fenfluramine, however, there was an increase in the discriminability of the highest phentermine dose and a slight decrease in the ED50 value of the combination. Thus, administration of phentermine + fenfluramine, having both dopamine-releasing and serotonin-releasing properties, respectively, may mimic the neurochemical activity by which cocaine acts in the central nervous system and may possibly allow for cocaine-like effects as these two drugs see increased use in obesity control.
Schechter M D; McBurney D
Life sciences
1996
1905-06
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/s0024-3205(96)00513-9" target="_blank" rel="noreferrer noopener">10.1016/s0024-3205(96)00513-9</a>