| A Unified Mechanism for the Process of Calcification in Hard and Soft Tissues, |
1972 |
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| Authors:
Fred Leonard; Clarence W. R. Wade; Andrew F. Hegyeli; James W. Boke; Robert J. Ruderman; WALTER REED ARMY MEDICAL CENTER WASHINGTON D C ARMY MEDICAL BIOMECHANICAL RESEARCH LAB
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 | Because adenosine 5' triphosphate (ATP) has been found in calcifying tissue and because this compound markedly influences calcification, it has been suggested that ATP may be an important intermediate in the calcification process. Furthermore, it has been proposed that mitochondria are involved in bone mineralization and that these oranelles can concentrate calcium ions in a process dependent on ATP. A mechanism of mineralization, cyclical in nature, and which can be ... |
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| Annual Progress Report, 1 July 1970-30 June 1971. |
01 JUL 1971 |
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| Authors:
Orlyn C. Oestereich; Fred Leonard; WALTER REED ARMY MEDICAL CENTER WASHINGTON D C ARMY MEDICAL BIOMECHANICAL RESEARCH LAB
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| The program of the U. S. Army Medical Biomechanical Research laboratory (USAMBRL) is directed toward research on the differentiation between necrotic and viable tissue, on the mechanism of mineralization of hard and soft tissue, on bone healing, on the development of internal and external body biomechanical materials and devices, and AMEDD projects as assigned. USAMBRL research projects are divided into tasks and work units and covered by Research and Technology ... |
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| TENTATIVE STANDARDS FOR DESIGN AND FUNCTION OF ELECTROMECHANICAL HANDS AND CONTROL SYSTEMS. |
JUL 1969 |
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| Authors:
Fred Leonard; Lloyd L. Salisbury Jr.; Albert B. Colman; WALTER REED ARMY MEDICAL CENTER WASHINGTON D C ARMY MEDICAL BIOMECHANICAL RESEARCH LAB
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| The standard covers right and left electromechanical hands which may be connected to or disconnected from an upper extremity prosthesis for amputees and which allows the amputee to control, select, and maintain prehension. (Author) |
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| A NEW MECHANISM FOR THE CALCIFICATION OF SKELETAL TISSUES. |
APR 1969 |
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| Authors:
Fred Leonard; Roger I. Scullin; WALTER REED ARMY MEDICAL CENTER WASHINGTON D C ARMY MEDICAL BIOMECHANICAL RESEARCH LAB
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| A new mechanism for the calcification of skeletal tissue is proposed in which ATP present in high levels in the mineralizing zone of cartilage first complexes calcium. The calcium complex is subsequently hydrolyzed to calcium acid pyrophosphate and then to hydroxy apatite. During the process, adenosine and orthophosphoric acid are also formed which combine to regenerate ATP. The process is thus cyclical. The mechanism describably by balanced chemical equations is ... |
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| A RATIONALE FOR THE PREPARATION OF NONTHROMBOGENIC MATERIALS. |
APR 1969 |
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| Authors:
Fred Leonard; WALTER REED ARMY MEDICAL CENTER WASHINGTON D C ARMY MEDICAL BIOMECHANICAL RESEARCH LAB
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| It is postulated that negative charges, per se, are insufficient to impart thromboresistance to a polymer surface. Rather, it is hypothesized that a specific steric array of negative charges is required; certain distribution favoring thromboresistance and others either not imparting thromboresistance or, indeed, enhancing the possibility of thrombus formation. The distances between charges required may be a function of whether an intramolecular calcium bridge may be formed. It is proposed ... |
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| CALCIUM SEQUESTRATION AND PHYSIOLOGICAL ACTIVITY OF HEPARIN. |
APR 1969 |
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| Authors:
Fred Leonard; WALTER REED ARMY MEDICAL CENTER WASHINGTON D C ARMY MEDICAL BIOMECHANICAL RESEARCH LAB
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| It has been demonstrated that heparin can sequester calcium and, based on this ability, mechanisms for several physiological functions for heparin are proposed. It is suggested that the calcium sequestering ability of heparin, apparently a neglected attribute, may be one of the general characteristics required for the multifaceted physiological functions attributed to heparin. (Author) |
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| MOLECULAR WEIGHT DISTRIBUTION OF HYDROXYETHYL STARCH SAMPLES. |
APR 1969 |
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| Authors:
Clarence W. R. Wade; Ramchandra K. Kulkarni; Fred Leonard; WALTER REED ARMY MEDICAL CENTER WASHINGTON D C ARMY MEDICAL BIOMECHANICAL RESEARCH LAB
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| Molecular weights and molecular weight distributions of samples of hydroxyethyl starch fractionated by ultrafiltration were determined by viscometric, osmotic, light scattering and sedimentation techniques. From the ratios of Mw/Mn, as well as the distribution of molecular weights determined by sedimentation measurements, it may be concluded that the samples were polydisperse. The results indicate, however, that fractionation did result in sharpening of the molecular weight distribution. It is possible that with ... |
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| HISTOCHEMICAL STAINING METHODS FOR LOCALIZING CYANOACRYLATE POLYMERS IN TISSUE SECTIONS. |
DEC 1966 |
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| Authors:
K. C. Pani; Walter M. McAllister; Fred Leonard; Peter M. Margetis; WALTER REED ARMY MEDICAL CENTER WASHINGTON D C ARMY MEDICAL BIOMECHANICAL RESEARCH LAB
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| A histochemical staining procedure was devised which makes it possible to visually locate and study clinically implanted polymers of alkyl alpha cyanoacrylates and isobutyl in tissue sections. (Author) |
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| ANNUAL PROGRESS REPORT, 1 JULY 1965-30 JUNE 1966 (FY-1966). |
30 JUN 1966 |
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| Authors:
Peter M. MARGETIS; Fred Leonard; WALTER REED ARMY MEDICAL CENTER WASHINGTON D C ARMY MEDICAL BIOMECHANICAL RESEARCH LAB
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| INTERFACIAL POLYMERIZATION OF N-ALKYL ALPHA CYANOACRYLATE HOMOLOGS. |
APR 1966 |
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| Authors:
Fred Leonard; John A. Collins; Harold J. Porter; ARMY MEDICAL BIOMECHANICAL RESEARCH LAB WALTER REED ARMY MEDICAL CENTER WASHINGTON D C
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| The normal alkyl - 2 - cyanoacrylates from methyl through n-octyl exhibit a reverse order of polymerization rate on biological substrates than on water. On water, the lower homologs spread and polymerize rapidly, whereas the higher homologs spread but polymerize slowly. On biological substrates, the lower homologs do not spread or spread slightly, and the higher homologs exhibit large spreadabilities and very rapid polymerization rates. Determination of the spreading coefficients ... |
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| THE BEOGRAD ELECTRONIC HAND. ANALYSIS AND RECOMMENDATIONS FOR FURTHER RESEARCH AND DEVELOPMENT, |
06 NOV 1965 |
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| Authors:
Fred Leonard; Lloyd L. Salisbury; Albert B. Colman; ARMY MEDICAL BIOMECHANICAL RESEARCH LAB WALTER REED ARMY MEDICAL CENTER WASHINGTON D C
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| SYNTHESIS AND DEGRADATION OF POLY ALKYL ALPHA CYANOACRYLATES. |
NOV 1965 |
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| Authors:
Fred Leonard; R. K. Kulkarni; George Brandes; Joshua Nelson; ARMY MEDICAL BIOMECHANICAL RESEARCH LAB WALTER REED ARMY MEDICAL CENTER WASHINGTON D C
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| In order to study structure-tissue reactivity relationships and ultimately develop a less necrotizing adhesive, a study of the synthesis and degradation of the homologous series of alpha cyanoacrylate monomers and polymers was undertaken. A method for synthesizing high purity cyanoacrylates and some of their chemical and physical properties are presented. In vitro kinetics studies under heterogeneous and homogeneous conditions indicate that cyanoacrylate polymers degrade by hydrolytic scission of the polymer ... |
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| PATELLA-TENDON-BEARING BELOW-KNEE POROUS SOCKET WITH SOFT SILASTIC DISTAL END, |
JUN 1963 |
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| Authors:
Robert E. Plumb; Fred Leonard; WALTER REED ARMY INST OF RESEARCH WASHINGTON D C
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| A technique for the fabrication of a porous patella tendon - bearing below knee socket with soft distal end which fairs into and is part of the inner socket wall is described. (Author) |
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Reports by Author
