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Biomedical subjects

G Endert

Publications and source records attributed to G Endert.

At least 19 recordsLinked to original sources
PubMed2002

Effect of dose and dose-distribution in damage to the kidney following abdominal radiotherapy.

PURPOSE: To define the effects of abdominal radiotherapy on the kidney with regard to dose-distribution parameters. MATERIALS AND METHODS: Ninety-one patients with abdominal radiotherapy were included in the study, and the minimum follow-up was 1 year. Conventional fractionation, 5 x 1.8-2.0 Gy week(-1) to total doses of 30.6-62.5 Gy, was employed. Assessment of organ function was performed before, immediately after, and at 6 months and 1 year after radiotherapy. In cases with a significant radiation response at 1 year, subsequent follow-ups were done at 6-month intervals. Documented parameters included clinical examination, static and sequential scintigraphy of the kidneys, abdominal computed tomography, and sonography. RESULTS: Twenty-one patients (23%) developed a reduction in kidney function detected by static scintigraphy. Only in 15 of these patients was impairment of renal function observed by sequential scintigraphy. The contribution of the irradiated kidney to overall renal function decreased progressively to 34-40% by the third year after treatment. Hypertension was seen in two patients. No changes were found in laboratory parameters. ED(50) for scintigraphic changes decreased from 27 Gy for 10% of the volume to 7.6 Gy for 100%. ED(5) were in the range of 3-6 Gy, and this was independent of volume. CONCLUSIONS: Sophisticated imaging techniques allow the identification of radiation effects in partial volumes of the kidneys. A dose-response relationship in relation to the volume of kidney irradiated can thus be established for scintigraphic changes. As in a number of other organs, such changes do not relate directly to loss of renal function due to the reserve capacity of unirradiated kidney tissue.

Blood Pressure↗
PubMed1999

[Functional esophageal scintigraphy (99mTc-DTPA)1.2. Presentation of a method for diagnosis of effective deglutition in patients with oral and hypopharyngeal tumors].

BACKGROUND: Today more than 60% of 65-year-olds complain of dysphagia or odynophagia. The aim of this study was to use esophageal scintigraphy as a means of estimating quantitative, reproducible, and comparable parameters of the swallowing ability in patients with tumors of the oropharynx and hypopharynx before and after surgery. Another group of patients suffering from larynx tumors was also examined prior to and following laryngectomy. METHODS: Fifteen male patients with T3/4 tumors of the oropharynx or hypopharynx, which were dissected followed by plastic surgery with a radialis flap, were examined before and after surgery. Esophageal scintigraphy was performed in 10 patients in this age group with T3/4 larynx tumors. The mean transit time (MTT in seconds) and clearance (in%) were the parameters evaluated. Condensed images were determined by averaging. Analog Polaroid images were also obtained. RESULTS: The 15 patients who underwent radialis flap surgery as a reconstructive measure showed a 60% improvement in the ability to swallow. Four of the 10 patients showed an obvious postoperative improvement in the ability to swallow as determined by clearance. With respect to the mean transit time, 2 cases out of 10 showed an improvement in the swallowing process. CONCLUSIONS: In patients who underwent reconstructive radialis flap surgery, it was possible to reestablish the continuity of the orohypopharynx, which is a prerequisite for the restoration of the swallowing facilitation. As a result one can expect an improvement in swallowing kinetics postoperatively. The patients who underwent laryngectomy required adaptation time to learn how to swallow under altered anatomical conditions. The primary reason for this is the altered pressure in the hypopharynx. Esophageal scintigraphy provides easily comparable parameters that serve as an ideal method for the objective determination of the ability to swallow in patients with these tumors. This method is neither poorly tolerated nor invasive and compared to other methods is a less costly alternative for examining the swallowing process.

Aged↗
PubMed1998

[Radiation effects in the left kidney after irradiation of the spleen].

BACKGROUND: An important component of treatment of malignant lymphoma is the radiotherapy. If the spleen has to be included in the irradiation field, the left kidney has to be considered as a risk organ. PATIENTS AND METHOD: In 25 patients, splenic pedicle or spleen was included in the irradiation field. These patients were followed up at 6-monthly intervals clinically and by renal scintigram. For 21 out of 25 patients, a volume-dose-histogram of the kidneys was made. RESULTS: A decreased uptake of activity by the left kidney was found in the static renal scintigram of 13 out of the 25 patients and was seen 6 months to 1 year after radiotherapy for the first time at a moderate intensity. The decreased uptake improved in 1 patient, but was progressive in 8 patients until a storage defect or a shrinking of the whole left kidney appeared. The volume-dose-histogram showed that a decreased uptake was seen in the upper half or whole left kidney respectively if at least 40% of the volume or the whole organ was irradiated with at least 20 Gy. 40% of the volume of the left kidney were exposed to at least 20 Gy in only for 3 out of the 12 patients with no decreased uptake. By means of the renal sequence scintigram a reduced function of the left kidney was determined for 11 out of 13 patients. The functional contribution of the left kidney deteriorated to 16 to 37% of the total function of the 2 kidneys. One patient developed a hypertension 1 1/2 years after radiotherapy; all other patients showed no clinical symptoms. Retention of substances in blood was not observed. CONCLUSIONS: The static renal scintigram enables defined radiation-induced lesions of parenchyma of the left kidney to be determined after irradiation of the splenic pedicle or spleen. The changes are predominantly subclinical but possible long-term effects are unknown. In the treatment planning all possibilities should be used to minimize the irradiation volume of the left kidney. Furthermore, all patients should be followed up at regular intervals on a long-term basis.

Follow-Up Studies↗
PubMed1995

[Doppler ultrasound studies of long-term follow-up of children with hemolytic-uremic syndrome].

AIM: In the present study, we compared the diagnostic value of Doppler sonography with "B-Imaging" in the acute and chronical period of the HUS in children. METHOD: For this, we analysed the Doppler sonographic measurement (Acuson-128) from 3 patients in the acute stage of the disease and 14 patients after approximately 5 years. All patients examined in the chronic stage of the disease had been treated by peritoneal dialysis in the acute stage. As a control, the Doppler sonographic analysis of the A. renalis was performed in 25 healthy children. RESULTS: During the acute phase of the HUS, we found a significant increase in both the resistive index (RI) and the pulsatility index (PI). In addition, the diastolic current in the A. renalis was decreased or the blood flow was reversed. The kidney volume as well as the echo was increased in all cases. A recovery of the kidney observed as beginning diuresis coincided with a return to normal parameters in the Doppler sonographic measurement. In patients examined after 5 years, both the RI and the PI value was significantly (p < 0.01) different from the control group. These parameters correlate with the effective renal plasma flow, but not with the glomerular filtration rate. CONCLUSION: We conclude that in the acute stage of the HUS either "B-Imaging" or duplex sonography yield pathological parameter values. For the observation of the renal symptoms during the chronic phase of the disease, duplex sonography is clearly superior.

Acute Disease↗
PubMed1991

[The evaluation of the adhesive properties of dental materials by using radioactive-labelled bacteria].

Dental materials with different surfaces were incubated with 111In-oxine-labelled bacteria Streptococcus mutans 20 min respectively 2 h, 6 h and 24 h. To determine the amount of the bacteria accumulated on the specimens we measured the radioactivity with a scintillation counter. The same measuring was done after decontamination by the help of ultrasonication. The comparison of activities shows that different dental material surfaces adhere different amounts of bacteria. The adhesive properties are material and time dependent, but the surface processing has a lower influence on the bacterial adherence. The lowest degree of bacterial adherence has the cobalt base alloy Gisadent KCM 83. On the other hand the highest remaining activity was found after decontamination of cobalt base alloy and PMMA resin Kallocryl A.

Adhesiveness↗
PubMed1990

[Urokinetography in the diagnosis and follow-up of obstructive uropathy in children].

With regard to different paediatric urological diseases nuclear-medical urokinetography using the tracer 99m-Tc-DTPA can identify typical functional patterns. By means of 261 investigations on 240 children, retroperistaltic waves, initial pyeloureteral and the final ureterovesical conus, dysperistaltic waves and interrupting empty strips with lacing, constrictive peristalsis can be shown in comparison with the normal anterograde "stair" pattern. Moreover, UKG as a functional method makes it possible to control the therapeutic success of antibiotics in urinary inflammations, the situation after stone discharges and application of vegetative systemic drugs. In our opinion the operative procedure and the prognosis of megaureters can be assessed. Consequently urokinetography is among the important preoperative investigations in paediatric urology and in the follow-up programme after reconstructive urological operations. Nuclear-medical isotope investigation is without significant risk and yields many diagnostic details. The method can be recommended for functional urological diagnosis in children or teenagers with high frequency of follow-up investigations or in patients with contrast medium allergy. Finally, ureter physiology can be checked in patients subjected to bone scintigraphy. Clinical research is possible via UKG without additional radiation exposure.

Child↗
PubMed1989

99mTc-labelling of leucocytes with 99mTc-DPO: a complex developed for myocardial imaging.

The lipophilic 99mTc-DPO complex, developed as a myocardial imaging radiopharmaceutical, was used to label leucocytes. After an incubation of 0.1 ml 99mTc-DPO (8 micrograms DMPE*2HCl) with mixed leucocytes in plasma, the labelling efficiency was over 70%. During incubation in 5 ml plasma, a loss of activity was found between 20% (1 h) and 35% (3 h) caused by elution. Disturbances of cell viability could not be found with the help of the chemiluminescence test. The in vivo recovery was determined in three dogs and was 45%-50% (0.5 h), 30%-36% (1 h), and 18%-24% (3 h). Autologous 99mTc-DPO-leucocytes were used on seven patients with suspected osteomyelitis, there were four true negative and three true positive results. The target/nontarget ratio determined by ROI in the positive cases was 1.8 to 2.5 at 3 h after injection.

Bone and Bones↗
PubMed1988

[Nuclear medicine diagnosis in venous diseases of the extremities].

The 125I fibrinogen test and radionuclide venography have so far been the two standard methods of thrombosis diagnosis via nuclear medicine. Both methods have been developed further as a result of scientific and technical advances in recent years. Direct visualisation of thrombi with the help of 111indium thrombocytes is becoming increasingly important. Direct visualisation of thrombi can be made still easier by antithrombocytic antibodies. In case of contrast medium intolerance, and in diagnosing pulmonary embolism, radionuclide venography can still be useful in combination with lung perfusion scintigraphy, even if nonionic x-ray contrast media are increasingly introduced. The diagnostic possibilities offered by contrast medium venography in respect of precise morphological vascular imaging and function diagnosis, are complementary in many problems of venous diagnostics.

Blood Platelets↗
PubMed1987

Percutaneous transluminal angioplasty (dilatation) of carotid, vertebral, and innominate artery stenoses.

Over a period of 5 years, 51 stenoses of brachiocephalic arteries were successfully dilated, and one subclavian occlusion recanalized in 42 patients. Among 24 patients there were 21 stenoses of the internal carotid artery, two stenoses of the common carotid artery, two stenoses of the innominate artery, five stenoses at the origin of the vertebral artery, and four stenoses of the subclavian artery. There were 17 patients who had stenoses of the subclavian artery. In 12 cases several arteries were affected. In 9 patients multiple (2-3) stenoses in these supraaortic arteries were dilated. In 4 cases bilateral dilatation of internal carotid arteries was performed. There were transient, minor complications in 2 patients.

Aged↗
PubMed1986

[111Indium-thrombocyte scintigraphy and percutaneous transluminal dilatation (angioplasty) of supra-aortic vascular stenoses. A new method for deciding therapy and for follow-up control].

Scintigraphy with 111indium-marked autologous platelets has been used during percutaneous transluminal dilatation of supra-aortic arterial stenoses; there were 14 successful dilatations and one attempted dilatation. The material consisted of nine stenoses of the internal carotid artery, two stenoses at the origin of the vertebral artery and four stenoses of the first part of the left subclavian artery. Deposition of thrombi could be demonstrated by scintigraphy, both before and after catheter dilatation. The value of this method for deciding on the type of treatment and for observing the course of percutaneous dilatation of cerebral vessels is discussed.

Angioplasty, Balloon↗