Biomedical subjects

Steven A Goldstein

Publications and source records attributed to Steven A Goldstein.

23 records · Page 2Linked to original sources

PubMed2002

Brevibacterium endocarditis: a first report.

There are few case reports of infections caused by Brevibacterium species, and there have been no previously reported cases of endocarditis caused by any of the 6 known species of Brevibacterium. We report the first case of Brevibacterium endocarditis (caused by Brevibacterium otitidis) in a patient with prosthetic heart valves. The patient responded to 6 weeks of treatment with vancomycin and 2 weeks with gentamicin, and she has been receiving long-term maintenance therapy with oral azithromycin.

Actinomycetales Infections↗

PubMed2002

Unique rodent model of distraction osteogenesis of the mandible.

Despite the increasing use of distraction osteogenesis (DO) of the mandible, the molecular mechanisms regulating new bone formation during DO remain poorly understood. The purposes of this study were (1) to establish a unique rodent model of DO capable of outlining parameters for new bone formation at the distraction site and (2) to determine a critical-size defect to differentiate osteogenesis resulting from distraction from conventional fracture healing at the osteotomy site. Adult Sprague-Dawley rats were fitted successfully with this newly developed distraction device. Analyses demonstrated that the device could distract the rat mandible reliably to 5.1 mm with complete union. Acute intersegmental gaps of 2 mm resulted in complete bony union in a manner consistent with fracture healing, whereas 3-mm acute gaps resulted in varying degrees of bony union. Acute intersegmental gaps of 5.1 mm invariably resulted in fibrous nonunion. In summary, the authors have developed a rodent model of DO of the mandible. Their distraction protocols resulted successfully in advancement to 5.1 mm with bony consolidation. Notable fracture healing occurred at immediate intersegmental spaces as large as 3 mm. A gap of 5.1 mm was sufficient to act as a critical-size defect, resulting consistently in fibrous nonunion. These findings validate the effectiveness of this distraction device and establish the critical-size defect of a rat mandible at more than 3 mm. This novel model of DO provides an effective method of examining fundamental mechanisms responsible for new bone formation in the craniofacial skeleton.

Animals↗

PubMed2002

Tissue engineering: functional assessment and clinical outcome.

The issues that should be considered as part of the design and evaluation of tissue engineering constructs with respect to their targeted clinical application are reviewed. This paper provides a general framework for the process of bringing tissue-engineering constructs from the laboratory bench to the patient's bedside, rather than presenting a detailed review of the engineering or biologic principles or mechanisms that are necessary for successful tissue engineering. Many of the principles are animated by using examples from current studies being developed in my laboratory or those of my collaborators. In all likelihood, multiple solutions or approaches will be found that lead to successful tissue-engineering constructs. The focus here is on the identification of critical parameters to be considered rather than specific design solutions. The review is therefore organized to reflect feasible sequences of activities formulated to take tissue engineering from concept to clinical reality.

Animals↗

PubMedDate not supplied

Characteristics of congenital scoliosis in a mouse model.

Pregnant mice were exposed to 600 ppm of carbon monoxide on gestation day 9. The carbon monoxide exposure produced 38 spinal anomalies in 17 offspring with congenital scoliosis. Microcomputer tomography improved the identification of spinal anomalies and detected more affected animals, as compared when magnified radiographs were used. The curves were measured and ranged from mild to moderate at an age that corresponds to childhood and, on average, remained at the range of mild to moderate through near-maturity. The group of mice with congenital anomalies near maturity contained severe curves. The bone mineral density (BMD) determined by microcomputer tomography in the mice with congenital scoliosis was the same as that in the controls. The cervical spine BMD was higher than the thoracic BMD, which was higher than the lumbar region in the controls and affected animals. The BMD was highest in the apex of the congenital curves in the animals that were near maturity. This relationship was not seen in the younger mice with congenital curves. Histology revealed growth rates in the hemivertebrae, which, over the last half of the growth period measured, had one-third less growth than the adjacent vertebrae. The hemivertebrae were wedged, but the adjacent disks were not.

Animals↗

PubMedDate not supplied

Transcutaneous fiber optic Raman spectroscopy of bone using annular illumination and a circular array of collection fibers.

Transcutaneous bone Raman spectroscopy with an exciting annulus of 785-nm laser light surrounding the field of view of a circular array of collection fibers is demonstrated. The configuration provides distributed laser light. The annulus is located 2 to 3 mm beyond the edge of the field of view of the collection fibers to reject contributions from skin and other overlying tissues. Data are presented for rat and chicken tissue. For rat tibia, the carbonate/phosphate ratio measured at a depth of 1 mm below the skin is in error by 2.3% at an integration time of 120 s and within 10% at a 30-s integration time. For chicken tibia 4 mm below the skin surface, the error is less than 8% with a 120-s integration time.

Animals↗