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At least 721 records · Page 40Linked to original sources

PubMed2006

[Usefulness of ultrasonically activated scalpel for pulmonary resection in video-assisted thoracoscopic surgery].

We evaluated the reliability and efficacy of the ultrasonically activated scalpel (Harmonic Scalpel) for pulmonary resection in video-assisted thoracoscopic surgery (VATS). Fifty-six cases of primary or metastatic lung cancer with history of lobectomy or segmentectomy from July 2003 to June 2006 were investigated. The ultrasonically activated scalpel was used to separate aborted lobulation and segment in the surgery. The outcome of the operation using the ultrasonically activated scalpel revealed the mean operation time of 224.5 minutes and mean blood loss volume of 116.7 ml. The chest drainage catheter was removed at the postoperative day 3.4 and hospitalization lasted 10.4 days on average. By means of statistical analysis, no significant differences were noted when compared with the cases using surgical stapler to separate the lobules or segments of the lungs. Histopathological results showed destruction of alveolar structures and denaturation of cells at the cut surface of the resected lung through the use of the ultrasonically activated scalpel. This method resulted in good lung expansion and preservation of the residual lung volume. Furthermore, it prevented postoperative air leakage by appropriate treatment to the cut surfaces of the residual lung. Indeed, the method appears to be useful in the separation of lung tissues in severe aborted lobulation and segmentectomy by VATS.

Aged↗

PubMedDate not supplied

Comparison of ultrasonic and mechanical cleaning of primary root canals using a novel radiometric method.

Although ultrasound is employed increasingly as an adjunct to biomechanical preparation in clinical endodontics for adult teeth, there have been no previous investigation of this technique for primary teeth. This investigation studied the efficacy of ultrasonication compared with mechanical cleaning in primary root canals using a novel radiometric method. The results indicated that in multiple-rooted teeth, ultrasonication with an endosonic file for 3 min was able to remove 81.1% of inoculated bacteria, compared with only 65.2% using conventional filing. A combination of mechanical filing followed by ultrasonication produced the best results, with greater than 95% bacteria removed. The results show that ultrasonication may be useful for primary teeth endodontics.

Dental Pulp Cavity↗

PubMed1991

Revision arthroplasty facilitated by ultrasonic tool cement removal. Part II: Histologic analysis of endosteal bone after cement removal.

This conclusion of a two-part series examines the effects of ultrasonic cement removal from canine femurs on the underlying endosteal bone. The purpose of the investigation was twofold: to qualitatively assess the immediate in vivo effects on bone of direct coupling as a method of ultrasonic prosthesis removal, and to determine the immediate and delayed histologic responses of cortical bone to ultrasonic cement removal as well as compare the response after cement removal by high-speed burr instrumentation. This histologic study of an in vivo model demonstrated no significant cortical bone damage with the use of ultrasonically driven tools. The authors conclude that this method for the removal of bone cement and securely fixed prostheses is safe and efficacious.

Animals↗

PubMedDate not supplied

Implant maintenance using a modified ultrasonic instrument.

With the increasing number of implants in place, oral hygiene and maintenance are imperative because implants are susceptible to plaque accumulation and calculus formation. This case study evaluated a modification of the common ultrasonic tip to remove calcified deposits on implant abutments and prostheses, and also evaluated ultrastructural changes on polished titanium. A modified "plastic" ultrasonic instrument was found to be clinically effective and efficient. This instrument, unlike a metal ultrasonic tip on an ultrastructural level, produced no irreversible changes on the evaluated commercially pure titanium test strip. The preliminary results of this modification of an ultrasonic instrument show promise for its use as an implant maintenance modality.

Dental Calculus↗

PubMed1990

[An in vitro study of the antimicrobial effectiveness of ultrasonic instrumentation].

Successful endodontic therapy is based upon the classic triad of diagnosis, adequate canal preparation, and obturation. Preparation for a root canal has two major components--debridement and shaping. Debridement, or cleaning, consists of removal of necrotic intracanal dentin and organic debris, and reduction of the bacteria inside the root canal. According to the research, the endontic ultrasonic system plays a valuable and significant and synergistic role in aiding the bacteriocidal mechanisms based on the cavitation and acoustic streaming effect. The purpose of this study was to compare the antimicrobial effectiveness of two newly developed endodontic ultrasonic devices and the conventional hand-filing techniques. Eighty single root canal teeth with deep caries or apical lesions were selected and evenly divided into 4 groups. The root canals were prepared using conventional hand filing or one of two newly developed ultrasonic filing systems, ENAC and CAVI-ENDO. The contents of the root canals before and after debridement were cultured in a thioglycolate culture tube. The results showed that in the ultrasonically prepared specimens irrigated with a normal saline solution, the microbial culture numbers were significantly reduced and obviously different from those prepared by the hand instrumentation technique. The above mentioned differences were statistically significant at the level of p less than 0.05 by the McNemar test and Chi-square test.

Bacteria↗

PubMed1990

[Quantification of mechanical versus ultrasonic technique in root canal preparation].

The previous investigations of the cutting efficacy of the paracanal dentine with different endodontic instruments have not quantified the amount of the tissue removed. The purpose of this study was to compare the effectiveness of various mechanical canal instrumentations with ultrasonic technique by measuring the weight loss of the root dentine. The investigation concerned 60 single-canal roots of freshly extracted human teeth. Each canal was primarily prepared with Beutel rock reamers, size 3, with penetration to the apex. After desiccation in the thermostat at 60 degrees C for 65 hours, roots were weighed using an electronic scale (Mettler, AE-163, West Germany) with a precision of 10(-4) grams. Samples were devided into six groups according to the endodontic instrument: (1)K-tupbe reamers, (2)K-files, (3) Hedstroem files, (4) giromatic cleansers, (5) giromatic files, (6) ultrasonic files. After having been prepared the root canal was thoroughly irrigated with 4 ml saline, redesiccated and reweighed. Ultrasonic instrumentation was the most effective in removing the root canal dentine compared with all mechanical techniques (t-test; p less than 0.005). The smallest amount of root canal dentine was removed by giro-files. This was statistically significant compared with K-files, giro-files and ultrasonic files. There was no significant difference among the other mechanical instruments used in this study.

Dentin↗

PubMed1989

[Effect of low- and moderate-frequency ultrasonic waves on the course of suppurative wound process].

The author conducted a clinico-laboratory and morphological evaluation of the effect of low- and moderate-frequency ultrasonics on the course of a purulent wound process. He found that ultrasonic waves of different frequency subbands differ in their effect on wound healing. The use of low-frequency ultrasonics is most expedient in phase 1, preference is given to ultrasonics of the moderate-frequency subband in phase 2.

Appendectomy↗

PubMed1987

[Ultrasonic hyperthermia of the animal brain].

The paper is concerned with the methods of ultrasonic hyperthermia of the cerebral tissues and the results of preliminary experiments on animals. Ultrasonic radiators made of piezoceramic plates were employed. Ultrasound frequency was 1.56 and 2.85 MHz. Tissue temperature was measured not less than at 14 points using single and "chain" thermocouples with 5 branches every 5 mm and thermistors. In spite of rather inhomogeneous acoustic fields of the ultrasonic radiators they can be used for obtaining homogeneous temperature distributions in tissues at depths up to 20 mm owing to high thermal conduction of tissues. The experiments have demonstrated a possibility of heating animal tissues up to hyperthermic temperatures by ultrasonic exposure of tissues both in cranial trepanation and through the intact skull.

Animals↗

PubMed1979

Effects of oxygen tension and pH on the ultrasonic absorption properties of sickle cells.

The ultrasonic absorption of sickle cells was compared with the morphological changes in these cells are produced by varying oxygen tensions and pH. A decrease in oxygen tension caused increased sickling and an increase in the ultrasonic absorption of the blood. An increase in pH reduced the ultrasonic absorption and decreased sickling. These findings indicate that ultrasonic absorption can detect changes in the aggregation state of sickle cell hemoglobin in situ within the red cell and that the method may be used to monitor the degree of sickling under various environmental conditions.

Adult↗

PubMed1986

Long-lasting protective effect of slow-release theophylline on asthma induced by ultrasonically nebulized distilled water.

We investigated the intensity and duration of the effect of a single dose of slow-release theophylline on bronchial hyperresponsiveness to ultrasonically nebulized distilled water in asthma. In six subjects with a history of mild asthma, we measured airway responsiveness to ultrasonically nebulized distilled water and serum theophylline at 4, 8, and 12 hours after treatment with placebo or slow-release theophylline (10 +/- 1 mg/kg, orally). To assess bronchial responsiveness, dose-response curves were established by plotting the baseline value of FEV1 and the largest FEV1 after each doubling dose of nebulized distilled water against the dose of nebulized water. The degree of bronchoconstriction induced by ultrasonically nebulized distilled water was significantly inhibited at 4, 8, and 12 hours after treatment with theophylline, at serum levels of 14.8 +/- 4.6, 14.4 +/- 2.8, and 12.0 +/- 2.5 micrograms/mL theophylline (mean +/- SD). Tremor occurred in three patients and was associated with nausea, epigastric pain, and tachycardia in one of them. We conclude that a single dose of slow-release theophylline has a prolonged protective effect on bronchoconstriction induced by ultrasonically nebulized distilled water, but in some subjects is associated with side effects that limit its clinical usefulness.

Asthma↗

PubMed1979

Detection of carotid occlusive disease by ultrasonic imaging and pulsed Doppler spectrum analysis.

Ultrasonic imaging of the cervical carotid arteries by ultrasonic arteriography and duplex scanning combined with pulsed Doppler spectrum analysis were investigated in a series of patients undergoing arteriography. By using the ultrasonic image as a guide for precise placement of the pulsed Doppler sample volume, the characteristics of blood flow at points of interest in the carotid arteries could be determined. Audible analysis of the Doppler signal permitted correct diagnosis of 23 of 26 (88%) high-grade stenoses or occlusions with ultrasonic arteriography and 24 of 26 (92%) with duplex scanning. Spectrum analysis of Doppler signals obtained with the duplex scanner detected all of the 22 high-grade stenoses. Spectral abnormalities of a lesser degree also were detected in 18 of 23 vessels (78%) with atherosclerotic plaques which should not have reduced cerebral blood flow. These techniques permit the accurate detection of and the distinction between high-grade stenoses and occlusion, as well as the identification of many plaques which are not large enough to affect intracranial hemodynamics.

Arterial Occlusive Diseases↗

PubMed1983

Comparison of conventional and ultrasonic nebulisation of bronchodilator drugs in asthmatic subjects.

The effects of ultrasonic and conventional nebulisation of bronchodilator drugs were compared in 20 adults with moderately severe asthma. The bronchodilating effect of fenoterol hydrobromide was not significantly enhanced by ultrasonic nebulisation, and ultrasonic nebulisation of ipratropium bromide gave significantly less bronchodilatation than conventional nebulisation. Despite theoretical reasons why ultrasonic nebulisation of bronchodilator might be more effective than conventional nebulisation, this was not borne out by this study.

Adolescent↗

PubMedDate not supplied

Physical properties of aerosols produced by several jet- and ultrasonic nebulizers.

In order to estimate the administered dose of inhaled drugs from aqueous aerosols, we have examined the output characteristics of eleven jet- and nine ultrasonic nebulizers. Under various operating conditions we measured driving pressure, airflow, solution- and solute output of the nebulizers, particle concentration and size distribution in the aerosol. The particle size distributions were determined of the dry particles from evaporated droplets of aerosolized 9 mg X ml-1 NaCl solutions by using a mobility aerosols spectrometer. These physical properties of the aerosols were found to vary considerably between nebulizers (even among specimens of the same type). Solution output per litre of air from the ultrasonic devices was 2 to 10 times larger than that from the jets, being dependent on electric power and driving pressure respectively. The jet nebulizers showed the largest particle concentration per litre of air. The volume median aerodynamic diameter of the droplets generated by the jet nebulizers was about 1.5-4 microns. With the exception of the Siemens TV 6000 and the Bosch Halomed, this diameter ranged between 3 and 7 microns among the ultrasonic nebulizers, being dependent on the frequency of the ultrasonic vibrations. The output characteristics appeared also to be affected by extension tubes, air vents, solute concentration and airflow. Solute output varied nonproportionally with solution output, which confirms the comparative merit of output measurements by weighing. The results of the present study can be used to estimate the administered dose of therapeutic or provocative agents by nebulizer equipment. Actual drug output can only be quantified by careful calibration of each separate set-up.

Aerosols↗

PubMedDate not supplied

Ultrasonic vocalizations as diagnostic tools in studies of developmental toxicity: an investigation of the effects of prenatal treatment with methylmercuric chloride.

Ultrasonic vocalizations were recorded during two tasks from four groups of neonatal CD rat pups. Groups 0, 2, 4 and 6 were the offspring from pregnant dams treated with 0, 2, 4 or 6 mg/kg methylmercuric chloride by gavage on gestation day 7. On the day of birth, Day 1, litters were randomly culled to 8 pups (4 males, 4 females). The pups were weighed on Days 1, 7, 14, 21 and 30, and no weight differences due to treatment were observed. At 5, 7, 9 and 11 days of age, ultrasonic vocalizations were recorded from the animals for 1 minute. Individual animals were placed in a small test chamber containing either soiled home cage bedding or clean bedding material. Half of the pups in each litter were tested in each "odor" condition, and the rate and duration of the vocalizations were measured for 1 minute. On days 8 and 9, pups were tested on a negative geotaxis incline during which time vocalizations were recorded. In both the "odor" and negative geotaxis tests, methylmercuric chloride affected vocalization rates in a nonlinear dose-response fashion. Regardless of treatment group, the pups vocalized at a higher rate and for a longer duration in the clean than in the soiled bedding test condition. These data showed the variability of the ultrasonic vocalization responses to be smallest for the animals tested at 11 days of age in the clean bedding condition. The results of this study suggest that the value of ultrasonic calls as dependent measures of toxicity may be strengthened by the use of multiple stimulus conditions in order to elicit a graded response pattern. This would facilitate the interpretation of potential nonlinear dose-response effects.

Age Factors↗

PubMed1983

Ultrasonic dilatation of the uterine cervix: morphologic evaluation of a new device in the sow.

The present study demonstrates that low-power ultrasonic activation of Hegar dilators reduces the mechanical force required for dilatation of the cervix. The acute and possible late effects of an ultrasonic dilator on the cervical mucosa in the sow were evaluated by histologic study and compared to the effects of similar mechanical dilatation. In both groups early effects were mild to moderate edema and vascular congestion of the cervical mucosa. The immediate changes were comparatively more pronounced after ultrasonic dilatation. No significant pathologic differences were noted five weeks after ultrasonic dilatation of the endocervical canal. Further study may prove the device useful for dilatation of the stenosed cervix and urethra in women.

Animals↗

PubMed1982

Stability of some bronchodilator solutions during ultrasonic nebulization.

The effect of ultrasonic nebulization on the stability of isoetharine hydrochloride and isoproterenol hydrochloride solutions was studied. Commercially available solutions of isoetharine hydrochloride 1%, isoproterenol hydrochloride 1%, and isoproterenol hydrochloride 0.5% were diluted to 0.25%, 0.125%, and 0.125%, respectively. The solutions were nebulized for 10 or 15 minutes using three ultrasonic nebulizers at 0, 3, 6, 8, and 24 hours. Before and after nebulization, the solutions were assayed for intact drug by chemical assay and by thin-layer chromatography (TLC). The nebulized mist was also collected and assayed. The extent of drug degradation from ultrasonic nebulization was calculated as the apparent percent loss of active drug. Results of the chemical and TLC analyses for samples from two nebulizers showed no substantial chemical degradation of isoetharine hydrochloride or isoproterenol hydrochloride in any solution. Chemical assay was not performed for the third nebulizer, but results of TLC analysis showed no substantial degradation of either drug in any solution. Under the simulated-use conditions of this study, solutions of isoetharine hydrochloride and isoproterenol hydrochloride were stable when nebulized ultrasonically.

Aerosols↗

PubMed1982

Ultrasonic hyperthermia and drugs as therapy for human tumor xenografts.

Ultrasonic energy can generate controlled, local hyperthermia (42 degrees C--43 degrees C), and ultrasonic hyperthermia results in increased cytotoxicity of chemotherapeutic drugs for the treatment of cancer. Human breast (MX-1) and lung (LX-1) tumors implanted subcutaneously in athymic nude mice were treated with a single application of ultrasonic (670 kHz, peak intensity of 5 watts/cm2) hyperthermia (43.0 degrees C +/- 0.5 degrees C) for 30 minutes in combination with suboptimal doses of cyclophosphamide, melphalan, or procarbazine. Delays in the tumor growth rate and temporary tumor regression were observed. Comparison of the tumor growth rate with single modalities, ie, drug or hyperthermia alone, shows evidence of synergistic effects of the combination of ultrasonic hyperthermia and melphalan on MX-1 and of hyperthermia and procarbazine on LX-1 tumors.

Animals↗

PubMed1994

[Supplemental potassium or magnesium via the trachea with ultrasonic aerosol inhalation].

The common ways for supplementing potassium or magnesium have some disadvantages. Gaining enlightenment from endotracheal medication in cardiopulmonary resuscitation, the author tried to supplement potassium or magnesium via trachea with ultrasonic aerosol inhalation. Hypopotassemia and hypomagnesemia were induced in forty rabbits. Utilized orthogonal experiment design, serum potassium and magnesium level were compared with oral, intravenous, intratracheal and ultrasonic aerosol inhalation routes. Potassium chloride, normal saline, potassium magnesium aspartate, magnesium sulfate and potassium chloride plus magnesium sulfate were given respectively. Serum potassium and magnesium levels were markedly increased after ultrasonic aerosol inhalation drugs were given. There were no significant differences between oral or intravenous route and ultrasonic aerosol inhalation. The pathological results of trachea and lungs were normal.

Administration, Inhalation↗