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Biomedical subjects

A A Pilla

Publications and source records attributed to A A Pilla.

4 recordsLinked to original sources
PubMed1990

Non-invasive low-intensity pulsed ultrasound accelerates bone healing in the rabbit.

The effect of ultrasound (US) on the rate of fibula osteotomy healing in 139 mature New Zealand white rabbits was assessed in this study. Bilateral midshaft fibular osteotomies were made using a 1-mm Gigli saw. US was noninvasively applied to one limb for 20 minutes daily, while the contralateral limb served as a control. A 2.5-cm PZT transducer was applied to both limbs, with the treated limb receiving a 200-microseconds burst of 1.5-MHz sine waves repeated at 1.0 kHz. The incident intensity was approximately 30 mW/cm2. Animals were killed at intervals between 14 and 28 days. Maximum strength increases (significant to p less than or equal to 0.01) ranged from 40 to 85% from postoperative day 14 to 23. On day 28, no significant difference in ultimate strength was noted. From day 17 through day 28, all US-treated fractures were as strong as intact bones (p less than or equal to 0.005). On the other hand, the ultimate strength of the control osteotomies attained intact values only by day 28. These results indicate that biomechanical healing is accelerated by a factor of nearly 1.7. This occurs with an overall acceleration of the healing curve in this fresh fracture model. If noninvasive low-intensity pulsed sine wave ultrasound can significantly accelerate bone repair in clinical application with an in-home treatment of 20 minutes daily, then US may be a useful adjunct for fracture care with a concomitant impact on patient morbidity.

Animals↗
PubMed1979

Cytofluorometry of electromagnetically controlled cell dedifferentiation.

Cellular morphology changes, which appear related to dedifferentiation (despecialization), have been produced in vitro in the nucleated red blood cell of the frog. This has been achieved by controlled alterations in the electrochemical environment of these living cells, both by a selective modification of the ionic concentrations of an isotonic amphibian Ringer solution, and by the electromagnetic induction of pulsating current having specific waveform parameters. Laser flow microfluorometry shows that the modified Ringer solution is able, per se, to partially trigger the process in the same time interval that certain induced current waveforms can significantly affect the number of cells in the so-called dedifferentiated state. It has also been found that, for a given waveform, the repetition rate appears to have a significant effect on the rate of cell change. Preliminary automated image analysis of cell smears suggests that dedifferentiated and normal cells have the same integrated optical density but different nuclear areas. In conclusion, it appears that, after the initial electrochemical trigger, the early stage of the process, when the cells move from a state of specialized function to one of less specific activity, is the unfolding of their chromatin supercoil, not involving DNA synthesis. Then cytofluorometry allowed us to identify, for the first time, fundamental modifications which occur in the cell nucleus under electromagnetic exposure.

Acridine Orange↗
PubMed1977

A non-operative salvage of surgically-resistant pseudarthroses and non-unions by pulsing electromagnetic fields. A preliminary report.

This report documents, for the first time, to the authors' knowledge, the therapeutic use in humans of low energy, electromagnetic fields pulsing in the extremely low frequency (E.L.F.) range. These fields, established outside the body, were used to treat congenital and acquired pseudarthroses and non-unions. Energy of this type appears to affect biological processes, not through heat production, but through electrically-induced changes in the environment of cells within the organism. Of the 29 patients included in the study, 17 had experienced at least one failure of surgical repair and, in each of these, amputation had been recommended. The overall success rate, including those patients treated with inadequate pulse characteristics and those who failed to follow the protocol, was in excess of 70 per cent. Improvements in the specificity of pulse characteristics hold promise for increasing the rate of success. The simple, clinical methodology, which is conducted on an out-patient basis, appears to be both safe and effective. It can be applied with or without surgery. This approach requires additional controlled investigations before it is ready for general use in the orthopaedic community. The indications for amputation of surgically-resistant pseudarthroses, however, should be reassessed. The principles and technology, which have been established during this endeavor, may have physiologic and practical significance for processes other than pseudarthrosis and non-union.

Adolescent↗