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Biomedical subjects

R L Larson

Publications and source records attributed to R L Larson.

At least 37 records · Page 2Linked to original sources

Clinical experience and early results of carbon fiber augmentation of anterior cruciate reconstruction of the knee.

Augmentation by autogenous tissue in the repair of acute anterior cruciate ligament injury has been found to be of benefit in providing a scaffold for the disrupted tissue and a stent to protect the repaired tissue, thereby ultimately increasing the strength of the repair. In both the acute setting and when autogenous tissue is used to reconstruct a chronic anterior cruciate-deficient knee, the substitute tissues require protection while revascularization and recollagenization take place. Potential solutions to these problems are sought in a ligament prosthesis, such as carbon fibers, that would be capable of providing both a stent for protection and an inducement for collagen ingrowth. Intra-articular reconstruction of the anterior cruciate ligament with autogenous tissue augmented by PLA-coated carbon fibers was performed in one group of ten patients. A second group of matched cases was similarly treated but without augmentation for controls. The results were analyzed at one year postoperation on both the 100-point protocol rating system and the authors' 200-point knee rating system. On the 100-point scale, the study group improved by 14.8% of the preoperative rating, while the comparison group improved by 23.3%. On the 200-point system, the study group improved by 21.9%, the comparison group by 22.6%. There was no demonstrable benefit in the use of carbon fiber to augment intra-articular, autogenous tissue anterior cruciate ligament reconstructions.

Adolescent↗

Noncutting methods of needle and syringe disposal.

The time required of nurses to cut needles and syringes, the costs of boxes used to cut needles and store used syringes, as well as some of the costs related to treating needlesticks are discussed. A new method of utilizing a large box (3 X 13 X 31 inches) in a medication cart is described. The box is made of one-quarter inch cardboard and waxed. It is replaced daily and incinerated. The system is time-saving, economical, and should reduce the number of needlesticks.

Equipment and Supplies, Hospital↗

Patellofemoral disorders: physical and radiographic evaluation. Part I: Physical examination.

Patellofemoral disorders present a diagnostic and therapeutic challenge to the orthopedic surgeon. By the sequential application of such basic diagnostic tools as inspection, palpation, and various measurements to a patient in standing, sitting, supine, and prone positions, a reproducible, comprehensive physical examination of the patellofemoral joint and entire lower extremity may be achieved.

Femur↗

Patellofemoral disorders: physical and radiographic evaluation. Part II: Radiographic examination.

Evaluation of the patient with patellofemoral complaints requires a comprehensive physical and radiologic investigation. The tangential view is most helpful in the evaluation of such patellofemoral disorders as chondromalacia, lateral patellar compression syndrome, and recurrent subluxation or dislocation. Commonly utilized tangential views include those described by Hughston, Merchant, Laurin, and Ficat. Multiple calculations available for quantitation of abnormal tangential views include the sulcus angle, congruence angle, lateral patellofemoral angle, patella index, and patellofemoral index. Lateral radiographic views commonly utilized to evaluate the patellofemoral joint for patella alta or infera include those described by Blumensaat, Labelle and Laurin, and Insall and Salvati. Utilization of all of the available patellofemoral radiographic views and calculations is impractical and unnecessary. However, to ensure diagnostic accuracy, a routine consisting of a reproducible radiographic technique and various, easily performed calculations that aid in diagnosis must be adopted.

Femur↗

24-hour unit dose dispensing of class III-V controlled substances.

Methods of controlling controlled substance (CS) inventories in unit dose dispensing systems vary. The two extremes are total floor stock of all CS drugs by the use of declining inventory signout sheets on the nursing unit to controlling only Class II and a few selected class III-V items. The method described herein outlines a systematic approach to controlling items on an individual patient basis consistant with the benefits of unit dose dispensing. A CS card assigned to each patient for each of his required controlled substance medications serves as an audit trail for doses consumed by the patient and provides a declining inventory receipt when returned to the pharmacy.

Drug and Narcotic Control↗

Nitrogen-metabolizing enzymes of Diplodia maydis, a Zea mays L. stalk rot causing fungus.

The nitrogen source available to Diplodia maydis in vivo is reported to affect the severity of stalk rot in maize. Nitrate and (or) ammonium salts were tested for their effect on the type of nitrogen metabolism found in Diplodia maydis in vitro. The level of glutamate dehydrogenase remained essentially constant on either nitrogen salt but nitrate reductase was induced by growth on nitrate salts and was not extractable on ammonium salts. Properties of nitrate reductase reported here are similar to those reported for the higher plant and Neurospora crassa enzymes. Thr relationship of nitrogen metabolism in Diplodia maydis to Zea mays L. stalk rot is discussed.

Ammonia↗

Z-plasty lateral retinacular release for the treatment of patellar compression syndrome.

Lateral retinacular release by Z-plasty technique in selected patients provides a relatively simple procedure for relief of symptoms in patellar compression syndrome and is a satisfactory initial surgical procedure in cases not responding to conservative therapy. Unfortunately, there is no specific symptom complex, physical finding, radiographic finding, or arthrotomy finding which delineates the patient with patellar compression syndrome who will benefit from an isolated lateral retinacular release. Some patients may require further extensor mechanism realignment procedures (e.g., medial capsular reefing, tibial tubercle transplantation, tibial tubercle elevation, etc.) to relieve the aggravating symptoms of parapatellar and retropatellar pain.

Adolescent↗

Liquid culture of Diplodia maydis.

Diplodia maydis, a Zea mays L. stalk rot causing fungus, was grown in Czapek-Dox broth and modifications of Fries liquid media using combinations of 1% cellulose, 1% sucrose and ammonium or nitrate-nitrogen. Conditions are defined to yield consistently maximum mycelial dry weight in two days in contrast to the usually reported five-day incubation period.

Cellulose↗

Gene-dependent flavonoid glucosyltransferase in maize.

A direct relationship between a specific gene and a specific enzyme involved in flavonoid biosynthesis is reported for the gene Bz and uridine diphosphoglucose: quercetin glucosyltransferase in maize pollin, seedlings, and seeds. Ratios are presented for specific activities of the glucosyltransferase from pollen, seed, and seedling tissues homozygous and heterozygous for Bz and homozygous for bz.

Flavonoids↗