|Pulsed Electromagnetic Fields (PEMF) and Intracellular Processes
New gene findings: what are the implications for OA? (1990). Syntex
Laboratories, Inc. 17(10):1,9.
Adey WR (1993). Whispering between cells: electromagnetic fields and
regulatory mechanisms in tissue. Frontier Prospectives, 3 (2):21-25.
Summary: "At the core of observed sensitivities to low-level EM
fields are a series of cooperative processes. One such series involves
calcium ion building and release. Available evidence points to their
occurrence at cell membranes and on cell surfaces in the essential first
steps of detecting EM fields. Also, attention is now directed to newly
defined roles for free radicals, that may also participate in highly
cooperative detection of weak magnetic fields, 'even at levels below
thermal (kT) noise."(p.21) "It is at the atomic level that
physical processes, rather than chemical reactions in the fabric of molecules,
appear to shape the transfer of energy and the flow of signals in living
systems." (p. 24)
Adey WR (1988). Physiological signaling across cell membranes and cooperative
influences of extremely low frequency electromagnetic fields. In: Frohlich
H, ed. Biological Coherence and Response to External Stimuli. Springer-Verlag,
Summary: Discussion of required field intensities as they affect degrees
Akizuki S, Mow VC, Muller F, Pita JC, Howell DS, Manicourt DH (1986).
Tensile properties of human knee cartilage: I. Influence of ionic conditions,
weight bearing, and fibrillation on the tensile modulus. J Orthop Res,
Summary: "The flow-independent (intrinsic) tensile modulus of the
extracellular matrix [ECM] of human knee joint cartilage has been measured
for normal, fibrillated, and osteoarthritic (removed from knee joint
replacements) cartilage. ...The tensile modulus of the ECM correlates
strongly with the collagen/proteoglycan ratio." (p.379)
Anderson JC, Eriksson C (1968). Electrical properties of wet collagen.
Summary: "The electrical properties of dried collagen and bone have
been studied by Fukada and Yasuda. Both were shown to be piezoelectric,
producing a measurable potential between opposite faces when stressed
and also deforming on application of a voltage.... The mechanism of streaming
potential at its simplest depends on the absorption of one type of ion
on the surface of the molecule, with an associated diffuse layer of ions
of the opposite type extending out from the molecular surface. When the
liquid streams past the molecule there is a net transport of one type
of ion with a resulting potential gradient, which may be measured by
means of electrodes placed in the stream. The magnitude of the streaming
potential is dependent on the type of molecule and the pH of the solution." (p.166) "These
results with wet collagen imply that, because it exhibits no piezoelectric
effect, it belongs to a group of higher symmetry than does the dry material." (p.167)
Bassett CAL, Pawluk RJ (1972). Electrical behavior of cartilage during
loading. Science, 178:982-983.
Summary: "When cartilage is deformed, it becomes electrically polarized.
At least two mechanisms seem to underlie this phenomenon, namely, a short-duration,
high-amplitude, piezoelectric-like response and a longer-duration, lower-amplitude
response secondary to streaming potentials. the polarity of articular
cartilage during loading could hypothetically facilitate joint lubrication."(p.982) "...
regions of growth are characteristically electro-negative.... Joint lubrication
during loading occurs largely as a result of the adherence of sodium
hyaluronate to the articular surface. This biopolymer is a strong polyanion
and would be expected to adhere more effectively to a positively charged
surface than to one which was negatively charged. Since cartilage itself
is fabricated to a large degree of protein-polysaccharides, which are
negatively charged, it would seem appropriate to assume that Nature developed
an electrostatically based method to facilitate cartilage lubrication
at the moment of loading."(p.983)
Benveniste J (1993). Transfer of biological activity by electromagnetic
fields. Frontier Prospectives, 3(2):13-15.
Summary: "The essential molecular functions appear in fact to be
determined by electromagnetic mechanisms. A possible role of molecular
structures would be the carrying of electric charges which generate,
in the aqueous environment, a field specific to each molecule. Those
exhibiting such coresonating or opposed fields ("electroconformational
coupling") could thus communicate, even at a distance. Therefore
a minute variation in the structure of molecules (plus or minus an atom,
or a rearrangement of an amino acid, for example), which even slightly
modifies their radiating field, would allow their message to be received
or not by a receptor, as in the FM waveband." (p.15)
Bjelle A (1977). Glycosaminoglycans in human articular cartilage of
the lower femoral epiphysis in osteoarthritis. Scand J Rheumatology,
Blakeslee S (1992, May 12). Magnetic crystals, guides for animals, found
in humans. New York Times, C1,C12.
Brandt KD, Radin E (1987). The physiology of articular stress: Osteoarthritis.
Hosp Pract, 103-126.
Summary: Describes some of the mechanisms of OA.
Breger L, Blumenthal NC (1993). Electromagnetic field enhancement of
membrane ion transport. Proceedings of the Thirteenth Annual Meeting
of the Bioelectrical Repair and Growth Society; October 10-13, 1993;
Dana Point, CA. BRAGS, 38.
Summary: Experiments to test Liboff's hypothesis concerning magnetic
fields and calcium diffusion were performed using artificial and biological
membranes with no results.
Buckwalter JA, Mow VC (1992). Cartilage repair in osteoarthritis. In:
Moskowitz RW, Howell DS, Goldberg VM, Mankin HJ, eds. Osteoarthritis:
Diagnosis and Medical/ Surgical Management. 2nd ed. Philadelphia: W.
B. Saunders Company, chap 4.
Calvino B, Villanueva L, Le Bars D (1987). Dorsal horn (convergent)
neurones in the intact anaesthetized arthritic rat. I. Segmental excitatory
influences. Pain, 28:81-98.
Summary: "In healthy rats, the convergent and non-noxious neurones
of laminae 3-6 are generally almost silent in the absence of an any stimuli
within the receptive field. This was also true in the present study for
the "typical" neurons; however about half (58%) of the "atypical" neurons
exhibited a high level, background discharge which sometimes showed dramatic
Calvino B, Villanueva L, Le Bars D (1987). Dorsal horn (convergent)
neurones in the intact anaesthetized arthritic rat. II. Heterotopic inhibitory
influences. Pain, 31:359-379.
Summary: "It is concluded that the input for triggering heterotopic
inhibitory influences by mechanical stimuli is altered in the arthritic
rat, a model of chronic pain. This is consistent with the known lowering
in threshold of nociceptive afferents innervating the joint capsule,
induced by arthritis."(p.360)
Caterson B, Lowther DA (1978). Changes in the metabolism of the proteoglycans
from sheep articular cartilage in response to mechanical stress. Biochim
Biophys Acta, 540:412-422.
Summary: "Cartilage integrity can be controlled by many factors
which influence the balance between synthesis and breakdown of its components.
The results presented here suggest that articular cartilage has the capacity
to respond to the mechanical stresses to which it is exposed and that
mechanical stress and motion are required for the maintenance of the
cartilage constituents at normal physiological levels." (p. 421)
Cochran GVB, Otter MW, Bieber W, Wu D (1993). Streaming potentials associated
with gap healing in canine tibia. Proceedings of the Thirteenth Annual
Meeting of the Bioelectrical Repair and Growth Society; October 10-13,
1993; Dana Point, CA. BRAGS, 9.
Summary: "This experiment measures the first in vivo measurements
of SPs from bone callus; it identified two factors which affect the electrical
output. First, the magnitude of SPs correlated roughly with the magnitude
of total strain on the callus; this was the dominant effect. As healing
progressed, and the enchondral layer became thinner and eventually disappeared,
the signals decreased as strain tended to be reduced and to become equalized
between callus and adjacent bone. Second, the signal strength...tended
to increase as the new bone became more dense, thus supporting the prior
observation that new and remodeling bone generates lower amplitude SPs/strain
(1) than does normal cortical bone..." (p 9)
Davey CL, Kell DB (1990). The dielectric properties of cells and tissues:
What can they tell us about the mechanisms of field/cell interactions?
In: O'Connor ME, Bentall RHC, Monahan JC, eds. Emerging Electromagnetic
Medicine. New York, NY:Springer-Verlag, 19-43.
Summary: In cell suspension, as the frequency is increased, permitivity
falls and conductivity rises. [Implication: at low Hz, permitivity highest,
but conductance low.] At low frequencies, cell membrane behaves as non-conductors
suspended in a conducting medium; most of the current is flowing in the
suspension around the cells. As it takes time for ion movements to occur,
low frequencies allow time for it to occur. Oscillations caused by rapid
alternating frequencies can generate heat; low frequencies are isothermal. "If
fields can affect enzymes and cells, [one should expect] to be able to
tailor a waveform as a therapeutic agent in much the same way as one
now modulates chemical structures to obtain pharmacological selectivity
and perhaps withhold many of the side-effects common to pharmaceutical
substances." [ref 58-Kell in a Wales local journal.]
DeWitt MT, Handley CJ, Oakes BW, Lowther DA (1984). In vitro response
of chondrocytes to mechanical loading, the effect of short term mechanical
tension. Conn Tissue Res, 12:97-109.
Summary: "The results presented in this paper demonstrate that it
was possible to elicit a direct response in vitro by chondrocytes to
mechanical stimuli over a 24 h period. There was an increase in the rate
of proteoglycan synthesis by the chondrocyte cultures..." (p107) "However,
high impact loads or abnormal loading of synovial joints results in loss
of proteoglycan from articular cartilage, fibrillation of this tissue
and cell death reflected in a loss of cellularity, changes which resemble
those seen in osteoarthritis." (p109)
Dunham J, Shackleton DR, Nahir AM, Billingham MEJ, Bitensky L, Chayen
J, et al. (1985). Altered orientation of glycosaminoglycans and cellular
changes in the tibial cartilage in the first two weeks of experimental
canine osteoarthritis. J Orthop Res, 3:258-268.
Summary: "Changes in the cellularity and in the nature of the matrix
were studied in the cartilage of the tibial plateau in experimentally
induced arthritis in the dog,.... The orientation of the glycosaminoglycans
was assessed by the new 'induced birefringence' method. The results indicated
that only the region of the medial tibial cartilage that was unprotected
by the meniscus was affected, showing increased water content, loss of
superficial cells, and a crease in orientation of the glycosaminoglycans.
Whereas the birefringence [orientation] of the collagen was unaffected,
the superficial area that lacked oriented glycosaminoglycans was markedly
increased; this may be a useful indicator of early osteoarthritic changes."(p.
Eyre DR (1991). Cartilage expression of a type II collagen mutation
in an inherited form of osteoarthritis associated with a mild chondrodysplasia.
J Clin Invest, 87:357-361.
Summary: "We postulate that the presence of the mutant protein molecules
in the extracellular collagen reduces the durability of the articular
cartilage and manifests as the disorder, severe primary OA. The fibrils
may be less able in the long term to cope with the mechanical stresses
that articular cartilage endures, perhaps through defects in material
properties. In addition the collagen may be more susceptible to extracellular
proteases that are active in matrix remodeling but which do not normally
degrade the collagen triple-helix. ...Because failure of the underlying
collagen fabric of cartilage appears to be a key, irreversible event
in the process of joint destruction in OA in all its subsets, defining
how this single amino acid substitution is etiologically associated with
severe but otherwise typical disease manifestations may prove instructive
in understanding osteoarthritic joint failure."(p.360)
Ficat C, Maroudas A (1975). Cartilage of the patella. Topographical
variation of glycosaminoglycan content in normal and fibrillated tissue.
Ann Rheum Dis, 34:515-519.
Summary: "The glycosaminoglycan content of normal cartilage is lower
in the knee than in the hip. This fact, together with the existence of
high pressures during load bearing, may be responsible for the greater
frequency of destructive lesions affecting the cartilage of the patella
compared with that of the hip."
Liu H, Abbott J, Bee JA. Pulsed electromagnetic fields influence hyaline
cartilage extracellular matrix composition without affecting molecular
structure. Osteoarthritis Cartilage. 1996 Mar; 4 (1): 63-76.
Summary: This study focuses upon the effect of PEMF on the composition
and molecular structure of cartilage proteoglycans. Sixteen-day-old embryonic
chick sterna were explanted to culture and exposed to PEMF for a 3h/day
for 48 h. PEMF treatment did not affect the DNA content of explants but
stimulated elevation of glycosaminoglycan content in the explant and
conserved the tissue's histological integrity. These results demonstrate
that exposure of embryonic chick cartilage explants to PEMF for 3h/day
maintains a balanced proteoglycan composition by down-regulating its
turnover without affecting either molecular structure or function.