Silver ions in the treatment of local infections.

A study of the use of free silver ions as an antibacterial and antifungal agent administered to infected local wounds has been conducted over the past two decades. A variety of iontophoretic techniques has been employed utilizing either pure silver wires or several types of silvered nylon fabrics as anodes in a direct current electrical circuit. A new type of silver nylon has recently been evaluated for the same use without iontophoretic current. In vitro studies of both techniques have demonstrated an effective, broad spectrum antibiotic effect including most silver-resistant strains. Over 100 cases of recalcitrant osteomyelitis have been treated with an overall success rate of approximately 65% and no evidence of argyria.

Silver anode treatment of chronic osteomyelitis.

Twenty-five patients with active, chronic osteomyelitis, resistant to conventional management, were treated with surgical debridement and daily application of electrically activated silver dressings. Sixteen (64%) cases resulted in closed, stable, pain-free wounds, with the remainder resulting in persistent drainage or amputation. Nine of 12 cases complicated by nonunion achieved union. In 13 patients an open-bone graft was performed and silver treatment continued: these tended to remain free of purulent drainage but fared no better than average in the long-term follow-up. The silver anode dressing seems to be an effective aid in the treatment of chronic bone infection when combined with adequate surgical debridement, thereby reducing the need for prolonged systemic antibiotics.

Sensitivity to change in electrical environment: a new bioelectric effect.

The action of a 60-Hz, 5 kV/m electric field on erythrocyte parameters in mice was determined. No effects attributable to the magnitude of the field were found, but a transition either from or to an environment containing the field caused decreased red blood cell concentrations and decreased hematocrits. The failure of others to observe effects on erythrocyte parameters following exposure to low-frequency electric fields may have been due to an inappropriate choice of duration of exposure.

Piezoelectricity in collagen films.

Tissue collagen exhibits several levels of structural organization, and this complicates efforts to determine the origin of its piezoelectricity. We made collagen films-by evaporation and electrodeposition from solution-and examined the relation between collagen's piezoelectricity and its electron microscopic appearance. We found that the electrodeposited films were more organized and exhibited higher piezoelectric coefficients than the evaporated films. Despite this, the evaporated films were piezoelectric, thereby suggesting that the effect originates either at the level of the tropocollagen molecule or, at most, with aggregated structures no larger than 50 A in diameter.

Fracutre healing in rats exposed to extremely low-frequency electric fields.

Fibular osteotomies in rats were exposed to an extremely low frequency field for 14 days. By histologic evaluation it was found that the healing rate was retarded by the field. The effect (which was replicated) occurred at much lower power levels than are presently employed in electircal osteogenesis.

Silver polymethyl methacrylate antibacterial bone cement.

An improved antibacterial bone cement was sought based on the addition of low concentrations of inorganic silver compounds to polymethyl methacrylate. Composites with AgCl, Ag-AgCl, Ag2O, Ag2SO4 and Ag3PO4 in concentrations of 0.05% to 1% by weight, were tested in vitro against bacterial cultures. All were effective, but Ag2SO4 was especially so, even after 7 weeks of incubation in normal saline. Compressive strength of the cement was not affected by these additions, except in the case of Ag2O. Biocompabibility tests in rabbit muscle for up to 12 weeks showed no significant difference between the Ag -PMM and plain PMM in tissue reactivity, both being minimal. These features, coupled with the broad spectrum of antibacterial activity and low allergic potential of silver, make Ag-PMM an attractive alternative to conventional organic antibiotic/bone cement composites.

The significance of electrically stimulated osteogenesis: more questions than answers.

The present technique of electrical osteogenesis represents the rediscovery of a method in clinical use over 100 years ago. That technique while reported to have excellent clinical results, was empirically applied and was totally discredited as having no scientific basis. Modern techniques report similarly useful clinical results, but similarly lack an accepted scientific basis. The techniques in present use differ so greatly among themselves that a common mechanism of action seems highly unlikely. Yet all report excellent clinical results. Serious questions are raised concerning the validity of the claims, the mechanism of action and the possibility of long-term undesirable side effects. These questions are not insoluble and the newer physical science disciplines seem well suited to reveal the mechanism of action. Appropriate research projects must be mounted and answers to these questions obtained before the technique is made available for wide application. The importance of this procedure far transcends orthopedic surgery and bone growth stimulation and if properly pursued, it may lead to revolutionary changes, not only in basic biology, but in the practice of clinical medicine in general.

Space osteoporosis: an electromagnetic hypothesis.

Loss of body calcium during spaceflight is a potential problem in long voyages. This loss does not appear to be caused by a deficiency in diet or exercise. The idea is advanced that the altered electromagnetic environment experienced in space may be at least partially responsible. We show that the electric field induced inside astronauts because of their motion in the geomagnetic field is greater than that which has produced a wide variety of biological effects in earth-bound experiments.

Relation between suicide and the electromagnetic field of overhead power lines.

Laboratory studies have shown that electromagnetic fields similar to those from high-voltage transmission lines can produce biological effects. Surveys of the actual effects of such lines on exposed individuals usually have been hampered by complicating factors tending to blur the data. By means of a new approach, however, correlation has been established between the presence of transmission-line fields and the occurrence of suicides in part of the Midlands of England.

Laplace plane analysis of impedance on the H meridian.

The AC impedance of a length of the H meridian not containing any acupuncture points was studied by means of Laplace plane analysis of the time domain response to an input voltage pulse. The ensuing frequency domain data were compared to the results of an identical analysis for two anatomically similar controls on either side of the meridian. The resistance of the meridian was significantly lower than either control.

Treatment of orthopaedic infections with electrically generated silver ions. A preliminary report.

Electrically generated silver ions have been shown previously to be a potent antibacterial agent with an exceptionally broad spectrum as indicated by in vitro testing. The present study reports on clinical experience using electrically generated silver ions as adjunctive treatment in the management of chronic osteomyelitis. Fourteen patients had fifteen treatment attempts: thirteen for chronic osteomyelitis of the tibia, one for acute and chronic pyarthrosis and osteomyelitis of the knee, and one for a chronically draining sinus after total hip replacement. Wound débridement, silver ion iontophoresis, and subsequent wound care (usually provided by the patient) resulted in control of the infection in twelve of the fifteen treatment attempts and in healing of the non-union after follow-up ranging from three to thirty-six months. The other three attempts led to two partial and one complete failure.

Effect of electrostatic fields on the chromosomes of Ehrlich ascites tumor cells exposed in vivo.

An effect of electrostatic fields on the chromosomes of Ehrlich ascites tumor cells exposed in vivo has been demonstrated. Cells exposed to horizontal electrostatic fields for two weeks had almost a threefold increase in the percentage of abnormal chromosomes when compared to control cells or cells exposed to vertical electrostatic fields for the same period. Extended exposure times of 4--15 weeks resulted in the disappearance of the aberrant chromosomes. It is suggested that the effected cells were incapable of cellular replication resulting eventually in their disappearance via cell death.

The effects of low voltage current on healing of thermal third degree wounds.

Bilateral third degree burns were created on the flanks of eight miniature swine. Each animal had one side treated daily with low intensity direct (LIDC) of 400 microamperes (muA) by contact electrode for 2 hours morning and afternoon until healing occurred. The polarity of the electrode was negative in 4 pigs and positive in 4 pigs. One group of 4 pigs had the eschar surgically removed 24 hours post burn. Weekly biopsies and cultures were taken of treated and control wounds. Results indicated: local treatment of 400 muA LIDC did not hasten or delay healing of thermal third degree burns; escharectomy hastened wound healing by 10 days, and superficial proteus infection occurred in 80% of all wounds.