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J L Denlinger

Publications and source records attributed to J L Denlinger.

11 recordsLinked to original sources
PubMed1993

Viscosupplementation: a new concept in the treatment of osteoarthritis.

Viscosupplementation is a new medical concept that has as its therapeutic goal the restoration of rheological homeostasis in pathological structures such as osteoarthritic joints. When the normal viscoelasticity of a solid tissue compartment or the elastoviscosity of a liquid tissue compartment is decreased under pathological conditions, normal function and regenerative processes are impaired. By introducing viscosupplementary devices, the normal rheological state of such compartments is restored or augmented. These devices stay in the tissue compartment for various periods of time, depending on the nature of the viscosupplement and the pathophysiology of the tissue compartment.

Animals↗
PubMed1991

Matrix engineering.

Matrix engineering is a technology that utilizes hyaluronan (HA, hyaluronic acid) based matrices to control, direct or augment tissue regenerative processes. Hyaluronan and the concept of matrix engineering have become established tools in ophthalmic and orthopaedic medicine. The clinical indications for HA are limited by the physical properties and short residence time of the natural HA molecule. To expand and improve upon its current medical applications, a family of HA derivatives was prepared by chemical modification and cross-linking. Relative to the non-modified HA molecule, the hylan family of polymers provides more versatile physical forms, improved mechanical properties and an extended residence time. Hylan can also be used as a surface coating to improve blood compatibility. The chemical, physical and biological properties of hylans will be reviewed, focusing on the specific therapeutic indications they enable.

Animals↗
PubMed1989

Clinical uses of hyaluronan.

The availability of elastoviscous solutions of highly purified hyaluronan has created two new therapeutic methods in human and veterinary medicine: viscosurgery and viscosupplementation. Viscosurgical tools and implants are widely used in ophthalmology and have been suggested for use in otology. Visco-supplementation of joint fluid using elastoviscous hyaluronan solutions is widely used in the treatment of equine traumatic arthritis. It was also suggested for use in idiopathic osteoarthritis in humans, but this application has not received wide acceptance. Cross-linked forms of hyaluronan have been developed and given the generic name of hylans. Water-insoluble soft gels of hylans are ideally suitable as viscosurgical implants to prevent postoperative adhesions and to control scar formation. Hylan solutions are being used in arthroscopic viscosurgery. Hylan devices in various forms (gels, tubes, membranes) have been used in animal studies for matrix engineering, the purpose of which is to control and direct tissue regeneration and augmentation.

Animals↗
PubMed1984

Exogenous Na-hyaluronate in the anterior chamber of the owl monkey and its effect on the intraocular pressure.

Exogenous, ultrapure (sterile, pyrogen-free), non-inflammatory fraction of Na-hyaluronate (NIF-NaHA) was introduced into the anterior chamber of owl monkeys (Aotus trivirgatus), replacing approximately 48% or 77% of the aqueous humor and creating post-injection intraocular pressures (IOPs) below normal (5-10 mmHg) or above normal (40-60 mmHg), respectively. Five different molecular weight samples (MW 1.7, 3.4, 3.7, 4.5 and 4.9 X 10(6)) were used. All solutions contained 1% NIF-NaHA and, because of the varying molecular weights, the viscosities of the solutions ranged between 10 000 and 930 000 cSt. The IOP and the rate of export of the exogenous NIF-NaHA from the anterior chamber were measured. All solutions caused an increase in the IOP, and the maximum level occurred at 4 hr after injection. In all cases, the IOP returned to normal 24 hr after injection. The highest and most persistent increase in IOP was observed after the injection of the solution with the lowest viscosity (10 000 cSt). The smallest increases in IOP over the post-operative value were observed after replacement of the aqueous humor using those samples with viscosities of 10 0000 to 300 000 cSt. The turnover (export rate) of injected NIF-NaHA depends for the most part on the viscosity of the injected solution. With increasing viscosity the rate constant, and therefore the half-life, of the injected NIF-NaHA decreases. The volume fraction of the viscous solution replacing the aqueous humor is also a determining factor in establishing the turnover rate. The molecular weight of the injected NIF-NaHA did not change during that time (48 hr) in which a sufficient amount of sample for analysis could be obtained. No evidence was found for the presence of any kind of hyaluronic acid-degrading agent in the anterior chamber.

Animals↗
PubMed1983

Aging in the musculoskeletal system of rhesus monkeys: I. Passive joint excursion.

In order to describe ontogenetic change in the musculoskeletal system of rhesus monkeys, 126 Macaca mulatta from Cayo Santiago, ranging in age from 7 months to 21 years, were examined under anesthesia. Passive joint excursions were measured at the wrist, elbow, shoulder, hip, and knee. Mean ranges of excursion at these joints differed significantly between age groups and by sex. The potential for most movements appeared to decrease approximately 25 degrees over the first two decades of the macaque life span, and males generally showed less potential for movement than females in all age groups. These results are similar to those obtained for humans and are consistent with patterns of positional behavior, trauma, and osteoarthritis observed in this rhesus monkey population. Thus, to fully describe the locomotor strategy of rhesus monkeys, age- and sex-related variation in locomotor anatomy and functional capacity must be considered.

Aging↗
PubMedDate not supplied

A preliminary assessment of Na-hyaluronate injection into "no man's land" for primary flexor tendon repair.

A special fraction of Na-hyaluronate (Healon) was used for enhancement of repair of flexor tendon lacerations in "No Man's Land" to assess its role in preventing adhesion formation. The profundus tendons of the third and fourth fingers in owl monkeys were lacerated and repaired, and the superficialis tendons were resected. Prior to closure, saline solution or Healon paste was applied around the tendon. The fingers were immobilized for 4-5 weeks with the proximal interphalangeal joint (PIP) at 90 degrees of flexion. Following immobilization, the range of motion of the PIP joint was tested in a standard fashion for a period of 3 months. The Healon paste did not interfere with the healing process of the tendon. The fingers treated with Healon showed a significantly less flexion deformity (p less than 0.01) than the saline controls. Healon paste may be a useful adjunct in tendon surgery.

Animals↗