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Biomedical subjects

R Engelking

Publications and source records attributed to R Engelking.

14 recordsLinked to original sources
PubMed1992

Impact of voltage and capacity on the electrical and acoustic output of intracorporeal electrohydraulic lithotripsy.

The electrical and acoustic output created by the spark discharge for electrohydraulic lithotripsy at the tip of a 3.3-F probe was evaluated. Spark generation was achieved by variable combinations of voltage and capacity. The effective electrical output was determined by means of a high-voltage probe, a current coil and a digital oscilloscope. Peak pressures, rise times and pulse width of the shock waves were recorded using a polyvinylidene difluoride needle hydrophone in 0.9% NaCl solution at a distance of 10 mm. The effective electrical output is lower than the calculated output, due to inductivities, capacities and resistances of the cables and plugs. The life of the probes is markedly shorter when a combination of high voltage and low capacity is used than with low voltage and high capacity corresponding to the same energy. The peak pressure and the slope of the shock front depend solely on the voltage, while the pulse width is correlated with the capacity. The pulse intensity integral of the shock wave is likely to be the best equivalent to the applied energy.

Electric Conductivity↗
PubMed1992

[Clodronate in the palliative therapy of bone-metastasized prostatic carcinoma].

Activity and side-effects of clodronate (Ostac), an inhibitor of osteoclastic bone resorption, were recorded in an open prospective uncontrolled study on 35 patients with metastatic prostatic cancer. All patients had progressive symptomatic bone metastases despite prior hormone therapy. Clodronate was initially administered i.v. for 8 days with 300 mg/day. This was followed by a daily oral administration of 1600 mg. The analgesic effect was evaluated by using a visual analogue scale and by recording the daily consumption of analgesic drugs. Karnofsky index and routine blood examinations, including PSA, were assessed. Repeated bone scans and radiological evaluations were performed. An improvement in pain was observed in 71% of the patients. The mean duration of improvement was 4 weeks. Average survival time was 12 weeks. There were no side-effects after i.v. administration. Slight gastrointestinal discomfort was observed in 3 patients after oral administration. No effect was observed on the extent or biology of the metastases. Clodronate is an effective drug for palliative treatment of symptomatic bone metastases of prostatic carcinoma. It causes fewer and less pronounced side effects than other palliative drug therapies.

Aged↗
PubMed1992

[Adjustable electrohydraulic lithotripsy for minimally invasive ureteroscopic stone treatment].

We report on 82 ureteroscopies and electrohydraulic lithotripsies performed with small semirigid ureteroscopes with a minimum outer diameter of 6.5 F and probes of 2.4 F and 3.3 F. Prototypes of new lithotripters were employed, which incorporate infinitely variable energy within a range of 265-1382 mJ per pulse. Increased energy was provided by a rise in voltage, thus modifying the peak pressure and the initial slope of the shock wave. One third of the stones were situated in the upper ureter, 15% in the middle and 46% in the lower ureter. In 54% of these cases previous ESWL (Dornier MFL 5000) had been performed without success. Over 85% of the manipulations were performed under local anesthesia and i.v. sedation. Stone contact was achieved in 99%. Lithotripsy was fully successful in over 90%. The average energy per pulse was 450 mJ. In 7% partial disintegration was achieved and the residual stone was flushed back into the renal pelvis followed by further effective ESWL treatment. One stone had to be removed by open surgery. There were no major complications, such as perforations, due to the electrohydraulic lithotripsy itself. One perforation was caused when the endoscope was advanced into the ureter. No strictures were seen at the 6-month follow-up examination. An indwelling stent was placed in 48% of cases, as the stone burden or an inflamed stone bed suggested this was necessary. We conclude that electrohydraulic lithotripsy with adjustable energy resulting in various peak pressures of the shock wave is a safe and effective method of endoureteral stone treatment.

Adolescent↗
PubMed1990

[Clinical value of new rapid nuclear magnetic resonance tomography in preoperative assessment of hypernephroma. A prospective comparative study of CT and MR].

The new technique of rapid magnetic resonance imaging (MRI) with a paramagnetic contrast agent provides excellent imaging of the kidneys and their lesions. MR imaging of this anatomical region at short breath holding intervals matches the well-known quality of computed tomography (CT) for the first time. MR and CT studies were performed on 36 patients with proven renal cell carcinoma. Different investigators evaluated the staging of the tumor by means of both techniques in a prospective study. In all patients a radical nephrectomy was performed. Surgical and pathological findings were compared. Though little difference was found in diagnostic value between the two systems, MRI results concerning the T-stage were better. Venous invasion was clearly shown by MRI without the use of contrast medium. Furthermore, sagittal and transaxial images provided a more direct assessment of the extent of the tumor and its demarcation to healthy parenchyma. Thus, MRI is helpful in planning of the surgical approach when organ-sparing excision of renal tumors is to be performed.

Adrenalectomy↗
PubMed1989

Ultrathin flexible endoscopes for ureteroscopy. A preliminary experimental and clinical study.

Recent advances in fiberoptic technology have resulted in the development of endoscopes with an outer diameter of less than 6 F, including an irrigating or working channel. After preliminary testing of these ultrathin fiberscopes for ureteroscopy on 6 pigs, 17 patients were examined during routine retrograde pyelography. Prototypes of flexible endoscopes without an actively deflectable tip and an outer diameter of 5.5 F (= 1.8 mm) and a 1.5 F (= 0.5 mm) channel were used. Fine-needle aspiration cytology was obtained through the channel. The feasibility, performance and benefits of ureteroscopy with ultrathin, flexible endoscopes were evaluated. At present the lack of maneuverability and the fragility of the fiberscopes limit this method. Yet its routine clinical use, in addition to retrograde ureteropyelography under local anesthesia, shows great promise.

Adult↗
PubMed1979

[Nephroblastoma, partly appearing as a sarcoma botryoides of the renal pelvis (author's transl)].

A renal tumour in a 4-year old girl morphologically appeared as both a nephroblastoma and, in parts, as a sarcoma botryoides of the renal pelvis. The histogenesis of this dysontogenetic tumour is most probably due to a disturbance of growth and differentiation both of the metanephrogenic blastema as well as partly of the urethral bud. This type of dysontogenetic tumour is extremely rare. Problems of diagnosis and operative therapy and the possibility of postoperative radiation therapy and cystostatic treatment are discussed.

Child, Preschool↗
PubMed1979

[In-vitro-technique for autoradiographic investigations of cell proliferation in benign and malignant alterations of the human urinary bladder mucosa from biopsy specimens (author' transl)].

An in-vitro double labelling technique with 3H- AND 14C-Thymidine was applied to biopsy specimens of the human urinary bladder mucosa in order to determine proliferation kinetics of normal bladder epithelium as well as its benign and malignant alterations. Application of above mentioned technique led to evaluable autoradiographs. The mean 3H-Thymidine labelling-index in bladder cancer was remarkably higher than in normal bladder epithelium and in benign papillomas. There was a good correlation between histologic grading of malignancy and increase of the mean 3H-Thymidine labelling index. Addition of 5-Fluorodesoxyuridine to the incubation medium had no influence on the labelling of the incubated tissue.

Autoradiography↗
PubMed1978

Operative treatment of vesicoureteric reflux in duplicated ureters.

Over a 10-year period 321 children underwent 490 antireflux operations. 21 duplicated vesicoureteric reflux was observed in 18 patients. The follow-up and the comparison with other authors results in 334 patients indicate that the submucosal inlay of the duplicated ureters is a particularly suitable operation. The Politano-Leadbetter and the Lich-Grégoir techniques yield good results.

Adolescent↗
PubMed1978

[Malignant tumor of the testicle and trauma: correlative evaluation (author's transl)].

1. There is no causal relationship between mechanical trauma and testicular tumor. 2. Only a traumatically related enlargement of the tumorous area can be acknowledged as aggravation of an existing testicular tumor. This is true also only when an infiltration from the scrotum and epididymis can definitely be diagnosed as metastases from the corresponding first lymph node stage. 3. With an existing testicular tumor, the release of metastases through a mechanical trauma cannot be ruled out. 4. There is no justification for the use of the term "pontine symptoms (Brückensymptome)" in a correlative evaluation of the relationship between trauma and testicular tumor.

Animals↗
PubMed1977

[Stenosis of the ureter opening in children. Etiology, clinical considerations, therapy (author's transl)].

In an analysis of 75 children with stenosis of the ureter opening, our results are compared to those in the literature (see in particular Tables 1 and 2). Abdominal pain stands out as the major symptom in more than half of the children. In our cases, intramural disturbances predominate in ca, 2/3 of cases, in the literature in about half of cases. The occurrence of extramural disturbances (accessory vessels, adhesions, higher opening of the ureter) occurs with equal frequency. The determining diagnostic procedure for stenosis of the ureter opening is an excretion urogram. Indications for a retrograde pyelogram and the performance of a micturation cystoureterogram are discussed. The operation of choice for stenosis of the ureter opening is the plastic operation of the renal pelvis of Anderson-Hynes, which has a success rate of at least 80%. Amoung our group of patients, primary nephrectomies were only seldom necessary.

Adolescent↗