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At least 19 recordsLinked to original sources
PubMed1977

[Sawing and welding with ultrasonics. Experimental investigation to test the applicability of an apparatus for sawing and welding bone tissue with ultrasonics in orthopedics (author's transl)].

An experimental investigation of a procedure for sawing and welding of bone tissue with ultrasonics in the area of orthopedics was reported. The welding of bone with ultrasonic waves, bone meal and a plastic adhesive did not product satisfactory results in terms of stability and tissue reaction. The applicability of the ultrasonic saw is limited by the thickness of the bone on which the osteotomy is to be performed. We saw no advantages over against the oscillating saws which were available to us. In our opinion, an indication for the application of the ultrasonic apparatus could be the removal of inflammatory, tumerous or necrotic bone processes.

Animals↗
PubMed1975

[Influence of ultrasonic waves and enzymes on antigenic properties of human erythrocytes. I. Ultrasonic waves].

In order to desintegrate the membranes and to isolate Rh antigens erythrocytes with well defined Rh patterns are treated with ultrasonic waves. The results of investigation of the homogenous sonicates allow the following tentative conclusions: The Rh antignes (C and E) are combined obviously with certain functional membrane areas of a given size. After sonication the activity of the sonicate to neutralize specific antibodies is greater than the activity of the same amount of untreated cells. It is supposed that this effect is caused by making accessible hidden antigens that are inaccessible in the intact membrane. Immunization of rabbits with the sonicates does not stimulate Rh-specific antibodies.

Antigen-Antibody Reactions↗
PubMed1978

The ultrasonic and computed tomographic appearance of splenic lobulations: a consideration in the ultrasonic differential of masses adjacent to the left kidney.

A splenic lobulation interposed between the tail of the pancreas and the left kidney is not uncommon. On prone ultrasonic scans, this variant of splenic configuration must be considered in the differentiation of anterior masses adjacent to the left kidney and masses originating in the tail of the pancreas. Computed tomography is the most sensitive method to use in making this distinction.

Humans↗
PubMed1979

Localization of hormone-producing gastrointestinal tumours by ultrasonic scanning.

The value of ultrasonic scanning in the localization of hormone producing gastrointestinal tumours was assessed in 16 patients. Fifteen patients had Zollinger-Ellison syndrome and one patient had a VIP tumour. In four patients with Zollinger-Ellison syndrome ultrasonic scanning demonstrated a solid mass lesion of the head of the pancreas of 2.2.4 and 8 cm respectively. One of these diagnoses was verified by autopsy, one was also found by subsequent CT-scanning and angiography. In one patient ultrasonic scanning demonstrated a 3 cm tumour of the tail of the pancreas. At ultrasonically guided percutaneous fine needle biopsy tumour cells were aspirated. Biochemistry confirmed a VIP tumour. In 11 patients ultrasonic scanning was normal. By laparotomy in nine of these tumours of 1--3 cm were found in three patients 5.9 and 15 months after scanning and in two patients multiple 0.5 cm tumours within the duodenal wall were demonstrated one half and 9 months after ultrasound. In four patients tumours were not demonstrated by surgery. Two of the 11 patients were not operated upon, and the tumours have not been localized. The advantages of the complete atraumatic, rapid and relatively cheap ultrasound technique and the ability of an ultrasonically guided biopsy for the demonstration of malignancy justify ultrasonic scanning to be an initial method of investigation in the localization of hormone producing gastrointestinal tumours.

Evaluation Studies as Topic↗
PubMed1975

An ultrasonic deflector for aspiration and biopsy.

A new ultrasonic deflector for aspiration and biopsy is described. It is made of a Plexiglas prism (45 degrees) with an oblique hole (27 degrees). The ultrasonic beam is bent in water by about 23 degrees. A puncture needle inserted through the prism hole passes through the ultrasonic beam in water with only minimal deviation from the beam axis. A fairly strong echo from the needle tip is a useful indicator for positioning the needle for aspiration. The resolution of the ultrasonic scan is not significantly affected by the deflector. This inexpensive ultrasonic deflector is capable of performing the functions offered by the expensive ultrasonic aspiration-biopsy transducer.

Biopsy, Needle↗
PubMed1978

Television synchronization of a real time ultrasonic sector scanner.

The interaction of the scan rates of ultrasonic scanning and television recording systems often causes portions of the resultant television image to be either over- or under-scanned. This results in objectionable bright and dark sectors within the ultrasonic image on a television monitor during single-frame playback. The usual method for dealing with this problem is to exchange time resolution for image quality when preparing pictures for analysis or presentation. Time resolution can be preserved by operating the ultrasonic scanner at a scan rate one-half of the television frame rate and phase locking the ultrasonic scanner to the television system so that each angular scan of the ultrasonic system is initiated coincident with the beginning of each television frame.

Humans↗
PubMed1979

Changes in ultrasonic attenuation indicative of early myocardial ischemic injury.

This study was designed to determine whether quantitative alterations in ultrasonic attenuation are associated with myocardial changes occurring after acute ischemic injury. Five hundred seventeen regions of myocardium from 41 dogs were studied in vitro at five intervals after coronary occlusion: 15 min, 1 h, 6 h, 24 h, 3 days, and 6 wk. Quantitative indices of ultrasonic attenuation were determined from the measured frequency dependence of the ultrasonic attenuation coefficient characterizing each myocardial region over the range 2-10 MHz. Independent definition of regions of ischemic injury was provided by either creatine kinase depletion or colloidal carbon dye distribution. Results of this study indicate that ischemic myocardial regions investigated 15 min to 24 h after coronary occlusion demonstrated ultrasonic attenuation significantly decreased from nonischemic regions (P less than 0.05). In contrast, ultrasonic attenuation was significantly increased in zones of ischemia or infarction investigated at 3 days and 6 wk after coronary occlusion (P less than 0.05 and P less than 0.01, respectively). These results indicate that altered attenuation of transmitted ultrasound by myocardium in vitro is an early manifestation of ischemia.

Animals↗
PubMed1977

Clinical assessment of analgesics using ultrasonic stimulation. A new method.

A quantitative method for measuring pain threshold by the use of ultrasonic stimulation in man was designed and the possibility of clinical application in assessing analgesics was investigated. Ultrasonic stimulus was given to Japanese subjects on the palmer distal part of the 2nd, 3rd and 4th fingers of both hands. The latent time between start of the stimulation and withdrawal of the hand when perceiving pain was considered the pain threshold. The ultrasonic evoked pain was a sharp pin-prick type, without sensations such as thermal and mechanical. The pain threshold lowered with increasing either stimulus intensity or water bath temperature when the hand of the subject was immersed during measurement. Normal threshold to ultrasonic stimulation measured in both 50 men and 50 women gave nearly normal distribution curves; women being more sensitive to ultrasonics than men. Analgesia with codeine phosphate (20 mg p.o.), aspirin (1.5, 1.0, 0.5 g p.o.), aminopyrine (100 mg p.o.) and mefenamic acid (500 mg p.o.) in volunteers of both sexes was demonstrated significantly using this method under double blind circumstances. Pentobarbital, diazepam, butylscopolamine, bromelain and placebo each in the usual dose used clinically failed to alter the pain threshold. Humans were at least 25 fold more sensitive than mice to the analgesics used herein.

Adolescent↗
PubMed1978

[Removal of intravascular thrombi by means of ultrasonics. Experimental study with a new method and its clinical use].

A new method of destroying thrombi in blood vessels by ultrasound and simultaneously removing them is reported. Experiments were performed in 19 dogs with artificial thrombi in the iliac and the femoral arteries and veins. The length of the thrombi ranged from 4 to 5 cm and the age from 12 h to 9 days. The unit used consisted of a generator, a frequency counter, an ultrasonic transducer with the hollow waveguide, and a vacuum pump. For protection of the vessel wall the guide is surrounded by a plastic tube. The ultrasonic frequency is 26.5 kHz, the amplitude 25--30 micrometer. The time needed to destroy the thrombus by ultrasound and suck out the thrombotic material ranged from 2.5 to 5 min. To check side effects, experiments were performed in 48 dogs. No changes resulting from ultrasonic irradiation were seen in the circulating blood or in the microscopic structure of the vessel wall. Ultrasonic thrombolysis was performed in a 42 year old patient with a 2-day-old thrombosis of the femoral artery. After 4.5 minutes of intermittent ultrasonic irradiation the artery was patent.

Animals↗
PubMed1978

The breakdown of spectrin produced by ultrasonication.

The application of carefully controlled ultrasonication to human erythrocyte membranes (ghosts) has been found to produce a selective breakdown of the two spectrin polypeptides. This breakdown increases with the time and the intensity of ultrasonication. The 240 000 molecular weight spectrin polypeptide is slightly more susceptible to ultrasonication than the 220 000 molecular weight polypeptide. Isolated spectrin behaves in an identical manner when ultrasonicated. When highly purified samples of spectrin are ultrasonicated the progressive reduction of the molecular weight of the products with increasing time is clearly apparent.

Erythrocyte Membrane↗
PubMed1977

Ultrasonic and radiographic cholecystography.

To define the relative merits of radiographic and ultrasonic cholecystography, we studied 208 randomly selected patients with possible cholelithiasis. The patients underwent both procedures, and the results were interpreted in blind fashion. Two hundred patients had satisfactory confirmation of their diagnosis, by either a well visualized radiographic cholecystogram or operation or both. The overall accuracy of the ultrasonic examination was 93 per cent, with a false-negative rate of 11 and an indeterminate rate of 4 per cent. The indeterminate rate was 24 per cent for the single-dose oral cholecystogram and 8 per cent for the double-dose oral cholecystogram. Both ultrasonic cholecystography and radiographic cholecystography are useful to detect gallstones. Our findings support using single-dose oral cholecystography as the routine first examination. If the gallbladder is not satifactorily visualized, ultrasonic cholecystography can be performed immediately. In an emergency or for patients who might be pregnant, ultrasonic cholecystography is available as the initial examination.

Administration, Oral↗
PubMed1977

The diagnosis of pancreatic cyst by endoscopic retrograde pancreatography and ultrasonic scanning.

Fourteen patients with verified pancreatic cysts were examined by both preoperative endoscopic retrograde pancreatography (ERP) and ultrasonic scanning. ERP showed filling of a cyst in 4 patients and raised suspicion of a cyst in 8. In two patients it was not possible to visualize the pancreatic duct. Ultrasonic scanning showed a cyst in 12 patients. There were two false negative ultrasonic diagnoses. These two were correctly diagnosed by ERP. Ultrasonically guided percutaneous puncture was carried out on 19 occasions in 8 patients. Cysts down to 2 cm in diameter were punctured without difficulty. There were no clinically significant complications due to the punctures. One patient was followed for 20 months without ultrasonically demonstrable recurrence of a large cyst aspirated, showing that definite therapy is possible by this method. Puncture can be used to verify the diagnosis and as treatment in patients where surgery is contraindicated.

Diagnosis, Differential↗