[Clotting induction in the mesenterium and erosive stomach mucosa in wistar rats as the result of a catenoidal ultrasonic transducer]. / Tromboobrazuvane v mezenterium i erozirana stomashna ligavitsa na plukh poroda Wistar sled vusdeistvie s katenoidalen ultrazvukov preobrazuvatel.

The ultrasonic transducers and instruments used in surgery operate in the range of 1-10 MHz and release significant heat in the surroundings. They need additional cooling system which significantly raises the cost and impedes the equipment operation. Hemostasis can be successfully achieved by employing ultrasonic transducers that operate in the kilohertz range, avoiding the occurrence of inadmissible tissue overheat outside the area of the transducer performance. The paper presents results of the approbation of the effect of a periodical acoustic signal with frequency of 60 kHz over the erosive stomach mucosa and mesenterium of 28 rats, "Wistar" breed, and the period of tissue exposure is 1-10 min. A transducer-catenoidal semi-wave concentrator that provides maximum emitted power of the ultrasonic wave is used and thermal effects are avoided. It is proved that the use of a powerful and localized ultrasonic signal results in erythrocyte diapedesis and forms microhaemorrhagies together with an out-vessel coagulation in the rat stomach mucosa The tissue damages are strictly limited within the area of the emitter contact and they are subject to control during the ultrasonic performance.

Footwear affects the behavior of low back muscles when jogging.

Use of modified shoes and insole materials has been widely advocated to treat low back symptoms from running impacts, although considerable uncertainty remains regarding the effects of these devices on the rate of shock transmission to the spine. This study investigated the effects of shoes and insole materials on a) the rate of shock transmission to the spine, b) the temporal response of spinal musculature to impact loading, and c) the time interval between peak lumbar acceleration and peak lumbar muscle response. It was hypothesised that shoes and inserts a) decrease the rate of shock transmission, b) decrease the low back muscle response time, and c) shorten the time interval between peak lumbar acceleration and peak lumbar muscle response. Twelve healthy subjects were tested while jogging barefoot (unshod) or wearing identical athletic shoes (shod). Either no material, semi-rigid (34 Shore A), or soft (9.5 Shore A) insole material covered the force plate in the barefoot conditions and was placed as insole when running shod. Ground reaction forces, acceleration at the third lumbar level, and erector spinae myoelectric activity were recorded simultaneously. The rate of shock transmission to the spine was greater (p < 0.0003) unshod (acceleration rate: Means +/- SD 127.35 +/- 87.23 g/s) than shod (49.84 +/- 33.98 g/s). The temporal response of spinal musculature following heel strike was significantly shorter (p < 0.023) unshod (0.038 +/- 0.021 s) than shod (0.047 +/- 0.036 s). The latency between acceleration peak (maximal external force) and muscle response peak (maximal internal force) was significantly (p < 0.021) longer unshod (0.0137 +/- 0.022s) than shod (0.004 +/- 0.040 s). These results suggest that one of the benefits of running shoes and insoles is improved temporal synchronization between potentially destabilizing external forces and stabilizing internal forces around the lumbar spine.

Evaluation of low back muscle surface EMG signals using wavelets.

OBJECTIVE: To compare the ability of observers to correctly detect the reaction time of erector spinae response to unexpected load by inspecting nonprocessed electromyographic signals versus inspection of wavelet transformed electromyographic signals and versus automatic detection on the same wavelet transformed signals. BACKGROUND: Traditionally, electromyographic signal analysis is performed using Fourier transform based methods. However, muscle response to transients such as unexpected load, have limitations when using these methods of electromyographic processing. DESIGN: A comparison was made of the three methods using the same signals attained during sudden loading of the trunk. METHODS: 11 chronic low back pain patients and eleven normal subjects were investigated in sudden loading. Surface electromyographic signals were obtained from the erector spine muscle at L3. The ability of observers to detect reaction time of erector spinae muscle responses of nonprocessed electromyographic signals versus inspection of wavelet transformed electromyographic signals versus an automatic peak detection program was determined. RESULTS: The results have shown that the spine muscle reaction time was easier and more accurately determined in the wavelet domain rather than in its original signal representation. CONCLUSION: Wavelet transform methods improved the analysis of electromyographic signals in the time domain by facilitating the determination of the time of muscle activity. RELEVANCE: Wavelet transform could be a valuable tool for electromyographic analysis in resolving the psychophysical problem of perception involved in the analysis of nonprocessed signals. In clinical environments, where the speed and the accuracy of the analysis of electromyographic signal is critical, the wavelet based signal processing could be very important.

Does arch height affect impact loading at the lower back level in running?

The purpose of this study was to evaluate the influence of the medial longitudinal arch height on the shock wave that repetitively reaches the lower back in running. Impact forces were measured simultaneously at the ground by a force plate and at the level of the low back, by means of an accelerometer, skin-mounted at the L3 spinal process. The medial longitudinal arch height was calculated as navicular height divided by foot length. Twelve healthy subjects ran barefoot and with an identical sport shoe at a constant speed. The sample size was divided equally into a low-arch and a high-arch group. Statistical analysis was performed by multivariate analysis of variance and Pearson's correlation. At low back level, there was a significantly lower acceleration amplitude and rate in the high-arch group (amplitude = mean, 1.74 g and SD, 0.94 g; rate = mean, 71.2 g/sec and SD, 58.0 g/sec) compared with the low-arch group (amplitude = mean 2.25 g and SD, 1.11 g; rate = mean, 111.5 g/sec and SD, 68.6 g/sec) (P < 0.001, each). At the ground, there was a slight negative correlation between arch height and initial loading rate in AP (-0.19; P < 0.01) and vertical (-0.22; P < 0.001) directions and a positive correlation between arch height and initial loading rate in the medial direction (0.22, P < 0.05). The results indicate that the high-arch foot is a better shock absorber with regard to the low back level than the low-arch foot.

[Lipoma of the temporal lobe]. / Lipom na temporalniia mozuchen dial.

This is a case report on a 16-year-old girl presenting lipoma located in the temporal cerebral lobe, in conjunction with an ever increasing frequency of epileptic seizures, unresponsive to the anticonvulsive treatment carried out. A comprehensive analysis is done of the data concerning clinical course, diagnostic examinations' specificity and microsurgical removal of the lipoma with ensuing optimal postoperative results--total abatement of epileptic seizures against the background of reduced anticonvulsive therapy throughout the 3.5 years observation period. The literature survey shows that intracranial lipomas with the location described represent as casuistic rarity.

Hyperextension and spine height changes.

STUDY DESIGN: The effect on spine height changes from different combinations of time and angle of static prone hyperextension, and one intervention of dynamic hyperextension was explored. OBJECTIVES: To explore whether controlled hyperextension would cause an height increase with greater duration than previously shown, and to find an optimal combination of hyperextension angle and duration of the intervention. SUMMARY OF BACKGROUND DATA: Hyperextension is a METHODS: Ten subjects were exposed to hyperextension in the prone position for different time periods and with different amounts of hyperextension. The effect was measured using the stadiometer for measurement of spine height changes. RESULTS: The study showed that time was the most important variable, and also that for a given time, there was an increased recovery with increased angle. CONCLUSIONS: The results indicate that hyperextension can be a beneficial maneuver to unload temporarily the spine after loading and to rehydrate the discs, providing enough time is given for the procedure. The optimal time and angle combination was 20 degrees for 20 minutes because this intervention resulted in the largest recovery that lasted for a relatively long period of time.

Muscular response to sudden load. A tool to evaluate fatigue and rehabilitation.

STUDY DESIGN: Subjects were exposed to fatiguing and restorative interventions to assess their response to sudden loads. OBJECTIVES: To investigate the erector spinae and rectus abdominis response characteristics to "sudden load" and the effect of fatigue and rehabilitation. SUMMARY OF BACKGROUND DATA: Unexpected loads which people often experience, can lead to high forces in the spine and may be a cause of low back injury. METHODS: Muscle responses to sudden load were mediated by fatigue, walking, expectation, method of load application, exposure to vibration, and cognitive-behavioral rehabilitation in patients with chronic low back pain. A novel technique, perfected in this work, called wavelet analysis, was used to analyze these data. RESULTS: Reaction time was affected by fatigue and expectation. Vibration exposure significantly increased the muscle response time. Walking was able to ameliorate that effect. Back muscles responded differently, depending on whether loads were applied to the back through the hands or through the trunk. Electromyographic reaction time and magnitude decreased in patients after a 2-week rehabilitation program. CONCLUSIONS: Sudden loads can exacerbate fatigue effects. Walking after driving reduces the risk to the back caused by handling unpredictable loads. Vibration exposure guidelines should be more conservative. Patients have longer response times than healthy subjects, but patients can improve their response to sudden loads via rehabilitation. Patients exhibit a flexion-extension oscillation at 5 Hz in response to a sudden load, suggesting that the 5-Hz, seated, natural frequency observed during whole-body vibration may result from neurophysiologic control limits.

European Spine Society--the AcroMed Prize for Spinal Research 1995. Unexpected load and asymmetric posture as etiologic factors in low back pain.

Unexpected loads, which often occur in the working environment, can lead to high forces in the spine and, thus, may be a cause of low back injury. This paper discusses the effect of "sudden load" on the erector spine reaction and amplitude. Muscle responses were mediated by several factors, including fatigue, posture, expectation and rehabilitation, in chronic low back pain patients. The subjects were fatigued by holding a 20% maximum voluntary contraction for 1 min. A functional restoration program was tested for its efficacy in reducing reaction time and EMG amplitude in chronic low back pain patients. Reaction time was longer and EMG amplitude lower in patients than in their matched controls. EMG reaction time and magnitude decreased in patients after a 2-week rehabilitation program, including specific training of coordination and posture control. The results of the modelling showed higher spinal compressive load and lower shear forces when the load was expected than when the load was unexpected. The effect of sudden loads can be exacerbated if a worker is not standing on a flat surface or is fatigued. Chronic low back pain patients have less ability to protect themselves from sudden loads, but they can be trained to improve their response by means of an appropriate rehabilitation program.

[The extracorporeal lithotripsy of gallstones in Bulgaria]. / Ekstrakorporalna litotripsiia na zhluchni kamuni v Bulgariia.

Extracorporal lithotripsy is a new, modern method of treatment of gallstone disease. The effect of the treatment was evaluated as follows: full--fragments up to 2 mm in size (in 60.5% of the patients), partial--fragments between 2 and 5 mm in size (in 30.1% of the patients) and no effect--fragments larger than 5 mm or lack of fragmentation (in 9.4% of the patients). Complications during the manipulation and after it were very rare--allergic in 1.7% and obstructive in 6.7% of the patients. In only 3 patients on operation had to be done. 84 patients were followed up for 270 or more days. In 10.4% of the patients a full clearance of the fragments was found, and in 28.2% of the patients there was only a reduction of their number. Extracorporal lithotripsy followed by litholytic therapy is a perspective method for gallstone disease treatment. It has wide indications, few contraindications, is well tolerated and is with a low complication rate.

[The clinical importance of determining aldosterone in the ascitic fluid]. / Klinichno znachenie na opredelianeto na aldosteron v astsitna technost.

A method for determination of aldosterone in ascitic fluid is worked out. In 20 patients with advanced liver cirrhosis and ascites the aldosterone level in the blood plasma and in the ascitic fluid was higher than in the healthy controls. The finding of elevated aldosterone level is important for the selection of diuretic since the efficacy of the diuretic treatment in patients with liver cirrhosis depends to a great extent on the level of renin activity and aldosterone.

[Superovulation induction in buffalo cows (Bubalus bubalis) with follicle-stimulating hormone (FSH)]. / Predizvikvane na superovulatsiia pri bivolitsi (Bubalus bubalis) s folikulostimulirasht khormon (FSKh).

A total of 19 buffalo cows were used to induce superovulation following a pattern that included the use of FSH at the rate of 40 mg in the course of four days, applied twice a day and of Oestrophan at 48 hours after the beginning of treatment. Fifteen animals manifested estrus and were twice inseminated. The superovulation response of the ovaries was 4.3 +/- 0.8 yellow bodies and 0.5 +/- 0.24 follicles greater than 8 mm. A nonsurgical method was employed to obtain 24 embryos of high quality and an unfertilized ovum from 8 buffalo cows.

[Changes in electrolyte homeostasis in acute loading of the right heart]. / Promeni v elektrolitnata khomeostaza pri ostro obreminiavane na diasnoto surtse.

The authors carried out experimental studies on electrolyte homeostatis of healty cats and of cats with experimental stenosis of the lung artery after venous infusion of the dextran plasma substitute Reoisodex. There was a statistically significant reduction only of the level of ionized calcium under the influence of the infusion. The authors established an increase of the level of inorganic phosphorus and of the serum bicarbonates in animals with experimental stenosis of the lung artery.