Biomedical subjects

D Korvick

Publications and source records attributed to D Korvick.

3 recordsLinked to original sources

PubMed2000

Evaluation of intrathecal gadolinium-enhanced MR cisternography in a rabbit model of traumatic nasoethmoidal CSF fistula.

This pilot study details the feasibility of intrathecal gadopentetate dimeglumine (Gd) administration in the detection of posttraumatic cerebrospinal fluid (CSF) fistula in an animal model. Five rabbits were used in this study. An attempt was made to create a traumatic CSF fistula surgically via a nasal approach. Seven days following the procedure, images of the cranium in sagittal and coronal planes were obtained utilizing a 1.9 T magnetic resonance (MR) imaging scanner before and after intrathecal injection of 16 pmol Gd. Following the imaging study, the animals were euthanized and grossly sectioned coronally to search for fistula formation. One animal died on the third day following the surgical procedure. The other four rabbits underwent the MR and gross pathologic study. Diagnosis of the fistula by intrathecal Gd-enhanced MR imaging was successful in two rabbits; this finding was confirmed by gross pathologic examination. No fistula was detected on either intrathecal Gd-enhanced MR imaging or on pathologic study in the remaining two rabbits. Intrathecal enhanced MR cisternography is a potentially promising technique for the evaluation of posttraumatic CSF fistulae.

Animals↗

PubMed1998

Imaging experimental osteomyelitis using radiolabeled liposomes.

UNLABELLED: We evaluated radiolabeled liposomes (liposomes labeled both with 99mTc and 111In) for the early detection of osteomyelitis in an experimental model. METHODS: Liposomes, containing 5% polyethylene glycol-distearoyl phosphatidylethanolamine with encapsulated glutathione and deferoxamine, were prepared and labeled with 99mTc and 111In by a previously described method. Acute osteomyelitis was induced in male New Zealand rabbits by intramedullary injection of sodium-morrhuate and Staphylococcus aureus in the tibial bone marrow. Serial imaging studies, consisting of radiolabeled liposome imaging (2-4 mCi 99mTc and 75-125 microCi 111In), 99mTc-methylene diphosphonate (MDP) (3-5 mCi) and 67Ga-citrate (500 microCi), were performed starting at the third day after injection. Each radionuclide study was separated by at least 2 days. The animals also underwent radiography of the lower extremities. The animals were then killed and the infected tibia was excised for histopathology. RESULTS: For interpreting relative efficacy of individual radiopharmaceuticals, only animals showing positive histopathological findings (n = 9) were considered. Radiographs (Days 12, 13) were conclusive for osteomyelitis in only 3 rabbits. Radiolabeled liposome imaging (Days 4-6) showed positivity in 8 cases and was equivocal in 1. Though the lesion could be delineated as early as 8 hr postinjection in the 99MTc window, the best target-to-nontarget ratio (T/NT) of 1.86 +/- 0.19 was obtained at 48 hr in the 111In window. Three-phase 99mTc-MDP scan (Day 7) was positive in only 5 rabbits with 3 hr T/NT of 1.6 +/- 0.23. Galium-67-citrate images (Days 9-11) were positive in 8 cases and equivocal in 1, the mean 48 hr T/NT being 1.74 +/- 0.24. These results show liposomes are better than 99mTc-MDP for imaging bone infection. Given the early localization and better quality of the images, radiolabeled liposomes also exhibited advantages over 67Ga-citrate for detection of acute osteomyelitis.

Acute Disease↗

PubMed1997

Variations in the mechanical properties of cartilage from the canine scapulohumeral joint.

OBJECTIVE: To measure the intrinsic material properties of scapulohumeral joint cartilage in adult dogs and determine whether regional differences exist within or between the humeral and glenoid cartilages. SAMPLES: Paired shoulder joints from 7 clinically normal adult dogs. PROCEDURE: An automated indentation apparatus was used to obtain the intrinsic mechanical properties of the cartilage at 7 sites on each joint surface. RESULTS: Topographic variations in mechanical properties of the glenoid and humeral cartilages were observed. The largest aggregate modulus (HA) for the humerus was seen at the caudocentral site (0.92 MPa) and for the scapula was seen at the centrocenter site (0.84 MPa). The mean shear modulus (mu) of humeral cartilage (0.23 MPa) was significantly greater than that of the glenoid cartilage (0.19 MPa). The mean Poisson's ratio (v) of humeral cartilage (0.24) was significantly smaller than that for the glenoid cartilage (0.29). Mean humeral cartilage aggregate modulus (0.71 MPa) was larger than the value for glenoid cartilage (0.67 MPa), but these differences were not significant. There were no significant differences in the compressive stiffness of the opposing cartilage in the canine scapulohumeral joint. CONCLUSIONS: Differences in mechanical properties between opposing humeral and glenoid cartilages are not a cause of cartilage injury in the scapulohumeral joint of adult dogs. The mechanical properties of cartilage from young dogs with open physes and incomplete subchondral bone plates may be different from those of adult dogs.

Animals↗