Some properties of hemolymph esterases from Leptinotarsa decemlineata Say.
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Animals↗
Biomedical subjects
S J Kramer
Publications and source records attributed to S J Kramer.
Age-dependent changes in juvenile hormone esterase and general carboxyesterase activity in the hemolymph of the colorado potato beetle, Leptinotarsa decemlineata.
An in vitro method has been developed for the quantitative estimation of juvenile hormone (JH) esterase activity in the hemolymph of the Colorado beetle Leptinotarsa decemlineata Say. The apparent Km value for JH-esterase was determined. JH-esterase and general carboxyesterase activities were estimated throughout the life cycle and under different photoperiodic conditions. High activities were observed in fourth instar larvae and in beetles just before diapause. Lower activities were found in third instar larvae, long-day, diapause and post-diapause beetles. Similar variations were found in general carboxyesterase activity but not in protein concentration. A possible role for the esterase in the regulation of the JH titer is discussed.
Aging↗
Posterior strut fusions to enhance immediate postoperative cervical stability.
UNLABELLED: In an attempt to enhance the immediate stability of posterior interspinous fusion constructs, the authors conducted the following project. Twenty-four adult mongrel dogs underwent a posterior C4-C5 fusion using iliac crest autogenous graft and internal fixation using either ulna struts (12) or metallic struts (12) fixed into position by sublaminar wires. Half of the animals were killed at either 1 week or 3 months postoperatively, and their C4-C5 motion segments were excised and studied radiologically, mechanically, and histologically. Both fusions created immediate and 3-month stability equivalent or superior to normal C4-C5 canine spinal segments. However, three dogs were rendered completely and two dogs incompletely quadriplegic by the surgery. CLINICAL RELEVANCE: Because of the relatively high rate of neurologic injury associated with these procedures in normal dogs, the authors hesitate to endorse their use in all but complete quadriplegic patients.
Animals↗
Acute hematogenous osteomyelitis of the epiphysis.
The case of an 11-year-old boy with acute hematogenous epiphyseal osteomyelitis is presented. Previous reported cases of epiphyseal osteomyelitis have been only of the subacute type. This case is presented to emphasize that osteomyelitis can occur in the epiphysis and reinforce the need for early diagnosis.
Acute Disease↗
Antibacterial and osteoinductive properties of demineralized bone matrix treated with silver.
The problems incurred by storage of demineralized bone allograft material and its potential use in contaminated operative sites make an antibacterial property desirable. Silver was considered for this role because of its wide spectrum of antibacterial susceptibility, low incidence of resistance, and its ability to persistently inhibit bacteria after binding to collagen matrices. Demineralized bone matrix prepared from rat diaphyseal bone segments was treated by exposure fo AgCl, AgNO3 and NaNO3 solutions prior to lyophilization. The resulting material was tested for bacterial inhibition after incubation in saline solutions for various times and showed inhibition persisting for at least four weeks (Ag-treated material only). Silver treating the matrix was found to partially inhibit the osteoinductive capacity at 10(-3) and 10(-2) M but not at 10(-5) M as measured by intramuscular implantation in the rat for six weeks. Control and NaNo3-treated specimens showed normal bone growth as measured by ashing and by 99mTc binding, and confirmed by radiologic densities. Histologic sections showed dense microdeposits on dense material predominately near the decalcified bone surfaces, but also within the matrix. The results suggest that pretreatment with silver at concentrations in the 10(-4) range would render the implant material antibacterial, protect its sterility, and leave the osteoinductive capacity intact.
Animals↗