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Biomedical subjects

M Nissan

Publications and source records attributed to M Nissan.

At least 19 recordsLinked to original sources
PubMed1999

Patterns of weight distribution under the metatarsal heads.

The longitudinal arch between the heel and the forefoot and the transverse arch between the first and fifth metatarsal heads, absorb shock, energy and force. A device to measure plantar pressure was used in 66 normal healthy subjects and in 294 patients with various types of foot disorder. Only 22 (3%) of a total of 720 feet, had a dynamic metatarsal arch during the stance phase of walking, and all had known abnormality. Our findings show that there is no distal transverse metatarsal arch during the stance phase. This is important for the classification and description of disorders of the foot.

Adolescent↗
PubMed1996

Effect of low-power He-Ne laser on fracture healing in rats.

BACKGROUND AND OBJECTIVE: Helium-Neon (He-Ne) laser radiation has been found to accelerate fracture healing in laboratory animal models as well as in cultures of cells involved in this process. We investigated the radiological, biomechanical, and histological effects of He-Ne radiation on fracture healing in a rat model. STUDY DESIGN/MATERIALS AND METHODS: Sixty-two rats underwent bilateral open osteotomies of the tibiae followed by internal fixation with intramedullary wires. The right leg received He-Ne laser radiation of 0, 2, or 4 Joules every other day for 2 to 6 weeks while the left leg served as a control. RESULTS: Radiological and histological examinations of the osteotomy sites failed to show any enhancing effect of He-Ne laser radiation on the bone healing process. Biomechanically, the irradiated bones of two of the six test groups were significantly weaker than the controls. CONCLUSION: These results fail to support the previously reported enhancing effect of He-Ne laser radiation on fracture healing.

Animals↗
PubMed1996

[Physical 3-dimensional testing of the lumbar spine using the IsoStation B-200].

Low-back pain is not only one of the major medical problems, but the most common. Up to 80% of the population is expected to experience back pain at least once in their lifetime. The functional disability caused by LBP has a major influence on quality of life, as well as its economic aspects. Psychological and social factors are highly involved with LBP. Therefore any advance in objective assessment of LBP is of major importance. We present a relatively new system used for the past 2 years by our departments, the IsoStation B-200 (Isotechnologies Co., NC). This system enables simultaneous 3-D measurements of range of motion, speed of movement and torques in the lumbar back in a highly accurate and reproducible manner. The results are used to classify the status of LBP in terms of severity and disability. They enable us to assess quality of performance and to detect the "symptom magnification syndrome" (SMS), patients with non-physiologic complaints and behavior. We describe in detail the measurement protocol and the exact definitions and criteria used in the process of patient classification. Finally we present the results of our first 238 patients tested. A highly significant difference in almost all measured and calculated parameters was found between the patients with physiologic behavior and those with SMS or nonphysiological behavior. Findings related to all classifications are presented.

Biomechanical Phenomena↗
PubMed1995

Spectral characteristics of chest wall breath sounds in normal subjects.

BACKGROUND: This study was carried out to establish a reliable bank of information on the spectral characteristics of chest wall breath sounds from healthy men and women, both non-smokers and smokers. METHODS: Chest wall breath sounds from 272 men and 81 women were measured using contact acoustic sensors, amplifiers, and fast Fourier transform (FFT) based spectral analysis software. Inspiratory and expiratory sounds were picked up at three standard locations on the chest wall during breathing at flows of 1-2 l/s and analysed breath by breath in real time. RESULTS: The amplitude spectrum of normal chest wall breath sounds has two linear parts in the log-log plane--low and high frequency segments--that are best characterised by their corresponding regression lines. Four parameters are needed and are sufficient for complete quantitative representation of each of the spectra: the slopes of the two regression lines plus the amplitude and frequency coordinates of their intersection. The range of slopes of the high frequency lines was -12.7 to -15.2 dB/oct during inspiration and -13.4 to -20.3 dB/oct during expiration. The frequency at which this line crossed the zero dB level--that is, the amplitude resolution threshold of the system--was designated as the maximal frequency (Fmax) which varied from 736 to 999 Hz during inspiration and from 426 to 796 Hz during expiration with higher values in women than in men. The mean (SD) regression coefficient of the high frequency line was 0.89 (0.05). CONCLUSIONS: These data define the boundaries of normal chest wall breath sounds and may be used as reference for comparison with abnormal sounds.

Adult↗
PubMed1994

Respiratory health screening using pulmonary function tests and lung sound analysis.

Lung sounds (LS) analysis is a potential source of additional objective, noninvasive and quantitative information on the status of the pulmonary system. We have examined the hypothesis that the addition of lung sounds analysis to spirometry increases the sensitivity of objective population screening, as compared to the use of spirometry alone. Questionnaires, spirometry and lung sounds were obtained in 493 active workers. Lung sounds analysis consisted of the averaged power spectra of breath sounds, measured separately during inspiration and expiration at four standard locations over the trachea and the chest-wall. Of the 493 subjects, 91 had an obstructive lung disease, including 27 with chronic bronchitis identified by a history of prolonged cough and sputum production but with normal spirometry. Twelve additional workers had a restrictive lung disease. Abnormal spirometric results were found in 74 of the patients. Abnormal lung sounds analyses were found in 54 patients, including 14 of the chronic bronchitis cases, so that the overall sensitivity of objective screening tests increased from 71% to 87% by combining the two tests. Thirty three of the subjects considered normal by evaluation of their questionnaire and spirometry had abnormal lung sounds. Of the twenty four who were re-evaluated 12-18 months after the first tests, three had developed a lung or heart disease. We conclude that the combination of spirometry and lung sounds analysis significantly increased the sensitivity of detection of pulmonary diseases by objective tests, and provided an early sign of lung disease that was not detected by spirometry alone.

Adult↗
PubMed1993

A microcomputer based lung sounds analysis.

The use of a microcomputer in lung sound-analysis is described. The system was used experimentally in order to evaluate automated auscultation as a mean for improving the sensitivity of pulmonary health mass screening. The sound signals from four custom-made piezoelectric transducers, affixed at specific locations on the chest wall, and the breathing flow signal produced by a pneumotachograph were amplified, filtered and digitized simultaneously at 4000 Hz per channel for 512 ms. The acoustic data were transformed to the frequency domain to enable the calculation of the power spectra. Those were averaged over successive runs and displayed as log power vs. frequency. The operator could assess the convergence of the spectral pattern using the on-line graphics and calculated parameters, and store the data once the noise level had reached a preset level. This procedure was repeated during expiration, inspiration and on breath arrest. The results of the off-line analysis of the lung sounds, combined with pulmonary function tests and a questionnaire, were used to identify lung pathology.

Auscultation↗
PubMed1992

Prevention of X-ray-induced late dermal necrosis in the pig by treatment with multi-wavelength light.

Low-level light from a multi-wavelength array of light sources has been used to prevent late X-ray-induced dermal necrosis in the pig. Skin fields, measuring 4 x 4 cm on the flank, were irradiated with a single dose of 23.4 Gy of X-rays. This X-ray dose was associated with the development of a 100% incidence of dermal necrosis, 10-16 weeks after irradiation. These irradiated skin sites were subsequently exposed to light of 660, 820, 880, and 950 nm wavelengths from a gallium aluminium arsenide multiple wavelength multidiode cluster probe (Biotherapy Medical Laser, 3ML), three times a week, from 4 to 16 weeks or 6 to 16 weeks after X-irradiation. The skin fields were exposed to the light pulsating at either 2.5 Hz or 5 kHz. With light pulsating at 5 kHz, energy densities of 0.22, 0.54, 1.08 2.16, 4.32, and 10.8 J/cm2 were used. Treatment with light pulsating at 2.5 Hz, 6-16 weeks after X-irradiation, or treatment with light pulsating at 5 kHz, 4-16 weeks after X-irradiation, did not have a significant effect on the incidence or the latency for the development of ischemic dermal necrosis irrespective of the exposure time to light at each treatment. With light pulsating at 5 kHz, no effect of light dose was observed. However, the overall incidence of dermal necrosis was significantly reduced (P = 0.001) to 52% in the X-irradiated fields receiving treatment with 5 kHz light, 6-16 weeks after X-irradiation.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1991

The initiation of gait in lower limb amputees: some related data.

The initiation of gait, from balanced standing position to the toe-off of the stance leg, was analyzed in 8 unilateral above-knee (AK) and 10 unilateral below-knee (BK) males amputees. Thirty-one parameters were measured, including ground-foot forces and the movements and timing of hip, knee, and ankle joints. The significant changes from the normal pattern of initiation of gait found in the AK and BK amputees, as well as significant changes between the two amputees groups themselves, are described. The amputees were divided into two subgroups: those who start walking with their prosthesis and those starting with their normal leg. The two groups were compared statistically for each amputation level and all were compared to a normal subjects group. Differences relating to the choice of the swing leg were found. The findings are reported as part of a future databank.

Adolescent↗
PubMed1990

Initiation of gait in normal subjects: a preliminary study.

The initiation of gait, from standing at rest to the toe-off of the second leg, was analysed in 15 normal subjects wearing shoes. Thirty-two parameters were identified and measured. The pattern of forces, angular movement and timing in this period are described and analysed. Two groups, one of 8 female subjects and another of 7 males, were compared statistically. Sex-related differences were found in the mediolateral and vertical forces as well as in which leg was the first to leave the ground. The values of all the parameters are given, as part of a database to be used in the future for diagnostic and assessment purposes in orthopaedics.

Adult↗
PubMed1990

[A respiratory health questionnaire for occupational screening].

A Hebrew pulmonary health questionnaire was designed for occupational screening, based on the American Thoracic Society questionnaire but adjusted to conditions in Israel. It was designed for assisted completion using a computer, but can easily be modified to become self-administered. We propose that it be used here as the standard, occupational, pulmonary health questionnaire and as the basis for a standard, general purpose, respiratory health questionnaire.

Humans↗
PubMed1989

Systemic effects of low-power laser irradiation on the peripheral and central nervous system, cutaneous wounds, and burns.

In this paper, we direct attention to the systemic effect of low-power helium-neon (HeNe) laser irradiation on the recovery of the injured peripheral and central nervous system, as well as healing of cutaneous wounds and burns. Laser irradiation on only the right side in bilaterally inflicted cutaneous wounds enhanced recovery in both sides compared to the nonirradiated control group (P less than .01). Similar results were obtained in bilateral burns: irradiating one of the burned sites also caused accelerated healing in the nonirradiated site (P less than .01). However, in the nonirradiated control group, all rats suffered advanced necrosis of the feet and bilateral gangrene. Low-power HeNe laser irradiation applied to a crushed injured sciatic nerve in the right leg in a bilaterally inflicted crush injury, significantly increased the compound action potential in the left nonirradiated leg as well. The statistical analysis shows a highly significant difference between the laser-treated group and the control nonirradiated group (P less than .001). Finally, the systemic effect was found in the spinal cord segments corresponding to the crushed sciatic nerves. The bilateral retrograde degeneration of the motor neurons of the spinal cord expected after the bilateral crush injury of the peripheral nerves was greatly reduced in the laser treated group. The systemic effects reported here are relevant in terms of the clinical application of low-power laser irradiation as well as for basic research into the possible mechanisms involved.

Animals↗
PubMed1988

New methods of treatment of severely injured sciatic nerve and spinal cord. An experimental study.

It has been demonstrated that low-energy laser irradiation (LELI) applied simultaneously to the injured sciatic nerve and the corresponding segment of the spinal cord, accelerates the process of regeneration of the injured peripheral nerve. A beneficial influence of LELI was also observed when it was applied to the spinal cord following transection and implantation of a segment of an autologous sciatic nerve, but further studies are necessary to evaluate if real regeneration or only earlier distal cord automatism occurred. Both methods are proposed for treatment of peripheral nerve lesions (PNS) and spinal cord injuries.

Action Potentials↗
PubMed1988

The in-vivo-nerve response to direct low-energy-laser irradiation.

To study the in-vivo effects of direct Low-Energy Laser Irradiation (LELI) on the Peripheral Nervous System, the sciatic nerve in rats was surgically exposed, crushed and then subjected to the direct irradiation of either of two continuous-wave HeNe lasers--0.3 mW or 17 mW. We found that the 0.3 mW laser significantly boosts the electrical activity in both the injured and non-injured nerves. The temperature changes of the nerve were measured during irradiation, and no thermal effect was detected. These findings could have direct therapeutic applications in various surgical situations.

Animals↗
PubMed1987

Response of peripheral nerve to He-Ne laser: experimental studies.

Low-energy He-Ne laser irradiation (LELI) was found to affect the electric activity and morphology in both intact and severely injured peripheral nerves in rats. Action potential (AP) in the healthy nerve increased by 33% following a single transcutaneous irradiation. Similar irradiation in crushed nerves caused AP to increase significantly over the AP of nonirradiated crushed nerve. Morphological observations revealed that a laser-irradiated injured nerve had diminished scar tissue as compared to an injured but not an irradiated nerve.

Animals↗
PubMed1986

HeNe laser irradiation delivered transcutaneously: its effect on the sciatic nerve of rats.

For our study of the effect of low energy laser irradiation (LELI) on living tissue we used HeNe laser on rats. The exponential absorption was reaffirmed in the living tissues overlying the sciatic nerve. An optimal range of energy between 3.5 and 7 J--associated with energy concentration of 4-10 J/cm2 delivered transcutaneously--was found to cause a significant increase in action potential in the sciatic nerve. The effect lasted for more than 8 months after the irradiation session.

Action Potentials↗
PubMed1986

Electrophysiological effect of HeNe laser on normal and injured sciatic nerve in the rat.

The effect of low energy CW HeNe laser irradiation on normal and dissected nerves in the rat was examined. The methods are described. Results are compared to the laser effect on other living tissues. HeNe irradiation was found to increase significantly the action potentials of the nerves. It was found to be a long-lasting effect, keeping an increase in the nerves action potential for more than eight months after irradiation has been stopped. A possible explanation for the way the irradiation acts on the nerve is suggested.

Action Potentials↗