Biomedical subjects
Publications and source records attributed to U Engelmann.
Following the real pathogenesis-concepts of periodontal diseases proposals are given for stomatological care, gradual and postgradual education and research work. This material is the short summary of a large one which was discussed at the 3d working session of the Society of Periodontology of GDR.
Free-flow electrophoresis is a fast and promising method for gamete separation. Pretreated seminal plasma-free human spermatozoa were injected continuously as a fine stream into the buffer medium of the separation chamber flowing perpendicular to the forces of an electrical field, which separated the spermatozoa according to their differences in electrophoretic mobility. For characterization of the two classes of spermatozoa before and after separation, quinacrine mustard staining was used to identify the Y-chromosome-bearing spermatozoa carrying the fluorescent body (F-body). Human spermatozoa moved toward the anode and were separated into two main peaks. The faster moving fraction contained nearly 80% Y-bearing spermatozoa and the slower peak consisted mainly of pure X-bearing spermatozoa. Whereas sperm viability as determined by eosin staining was nearly unchanged, sperm motility was reduced after free-flow electrophoresis.
The absorption of chemotherapeutics after local application in the urinary bladder is important for optimum therapy. We therefore investigated the absorption of Cisplatinum (Pt) through the bladder wall in 100 female Sprague-Dawley-rats after instillation under different clinical and pharmacological conditions. Only low platinum (Pt)-concentrations of about 1 microgram/ml could be detected in the serum using unmodified Cisplatinum solutions for instillation in the rat bladder indicating a rather low absorption rate for Cisplatinum. The extent of the absorption of Cisplatinum through the instilled bladder increased with the instilled volume. The absorption rate also increased after electrocoagulation and during cystitis with a maximum concentration of about 2.64 micrograms/ml. Correspondingly the vesicoplasmatic gradient factor clearly decreased. On addition of the detergent Tween 80, the serum Pt-concentration increased rapidly during the initial 30 min. Under these conditions Cisplatinum penetrated the bladder wall, about three times more effectively than in the absence of Tween while entering the systemic circulation only at about twice the normal rate without Tween 80. On addition of the polar organic solvent dimethylsulfoxide (DMSO) serum Pt-concentration increased continuously during the following 2 to 3 h reaching maximum values of about 13.3 micrograms/ml. The greatest accumulation of Pt in the bladder tissue (about 1,600 micrograms Pt/g tissue) was also observed under these conditions. A comparison of the Pt-concentration in serum with that in the bladder wall showed the most favourable relation of high tissue penetration and low serum concentration using Tween 80.
A comparative study was undertaken to investigate the application of a specially adapted microsurgical Neodymium Yag Laser system with a wavelength of 1,319 microns and a CO2 laser system for laser assisted microvascular end-to-end anastomosis (LAMA) of the rat femoral artery. Conventionally sutured anastomoses served as controls. Postoperative investigations included patency tests, light microscopy and tensile strength measurements. Both laser systems seem to be equally suitable for LAMA: The patency rates do not differ from those of sutured anastomoses and formation of microscopically small aneurysms occurred predominantly in control animals and only once in laser groups. The clamp time needed for LAMA was half the time that was needed for sutured anastomoses. Wound healing in all groups was similar with less fibrotic reactions and less foreign body granulomas in laser groups. At all intervals tensile strength was significantly higher for sutured anastomoses while differences between the CO2- and the ND: Yag-laser groups were not statistically significant. Potential applications in urology include microvascular anastomoses in erectile dysfunction, pediatric and reconstructive urology.
A randomized, controlled study was begun in 1982 on the effect of keyhole-limpet hemocyanin and mitomycin C in the prevention of recurrent superficial bladder cancer (stages pTa to pT1, grades 0 to 3) in 44 patients. All tumors were resected and all patients were presumed to be free of tumor at initiation of the prophylactic instillations. Before the bladder instillation program was begun all patients in the keyhole-limpet hemocyanin group Ia were immunized with 1 mg. keyhole-limpet hemocyanin intracutaneously and then monthly bladder instillations of 10 mg. were given. The control group Ib received 20 mg. mitomycin C monthly. Of the 21 patients in the keyhole-limpet hemocyanin group Ia (mean followup 20.7 months) 3 (14.2 per cent) had recurrences, compared to 9 of 23 (39.1 per cent) in the mitomycin C group Ib (mean followup 18.3 months). The over-all preventive effect was significantly better (p less than 0.05, chi-square) in keyhole-limpet hemocyanin-treated patients than in those given mitomycin C. In 1984 a new single drug study (group II) was started with keyhole-limpet hemocyanin alone, administered as in group Ia. Of 81 patients in group II (nonrandomized, mean followup 22.8 months) 17 (20.9 per cent) had recurrences. Of the patients given keyhole-limpet hemocyanin 20 of 21 (95.2 per cent) in group Ia and 70 of 81 (86.4 per cent) in group II had complete and partial prevention (downgrading), compared to 16 of 23 (69.5 per cent) in group Ib. Our study was established to analyze the effect of a new method of immunotherapy; no adverse local or systemic side effects were noted.
The computer tomograms of 22 patients with renal oncocytomas were analysed retrospectively. Characteristic findings were: 1. solid round space-occupying lesions (22/22), 2. sharp demarcation from the kidney (20/22), 3. smooth margin (20/22), 4. hypodensity after intravenous contrast (20/20), 5. enhancement (19/19), 6. central hypodense nidus (16/22), 7. homogeneous beyond the nidus (11/22). In the presence of these criteria, the diagnosis of an oncocytoma may be suspected. Safe differentiation from a renal cell carcinoma may not always be possible.
The angiographic findings in ten patients with renal oncocytoma are described. Characteristic features include: absence of encasement, vascular occlusions, arterio-venous shunts and contrast lakes (8/10). Spoke-wheel arrangement of tumor vessels (8/10). Homogeneous tumour contrast during the capillary phase (7/10). Sharp demarcation from the kidney and surroundings (9/10) and a peritumoral halo (4/10). If the suspicion of an oncocytoma is raised by CT examination of a space-occupying lesion (part I), angiography should be performed to confirm the diagnosis and help in planning surgical treatment.
The use of microcomputers in medicine is rapidly increasing. To handle clinical data and to facilitate clinical research, a system based on several personal computers that can be linked together was developed. Commercially available software was used, consisting of a powerful relational database complemented by programs for statistics, graphics and desk top publishing. The low cost, modular and flexible system was handled by untrained personnel; computer specialists were not needed. Data on more than 1100 patients have been entered so far and data retrieval can be done by the physician "on the spot" using standard prefabricated reports. Data can then be analysed statistically and processed to graphics and publications.
A comparative study was undertaken to investigate the Nd:YAG and CO2 laser systems for laser-assisted vasovasostomies (LAVs). In 32 rats 64 vasovasostomies were performed, either conventionally sutured (CSV) or laser-welded (LAV-CO2 and LAV-Nd:YAG). Postoperative investigations included patency tests, gross examination, light and electron microscopy. The highest rate of sperm granulomas (50%) and the lowest patency rate (50%) was seen in the LAV-Nd:YAG group. LAV-CO2 showed the lowest rate of sperm granulomas (12.5%) and had a patency rate (82%) which was comparable to that of CSV (88%). Laser-assisted vas anastomosis is time saving and technically easy to perform. Contrary to microvascular anastomoses, where both laser types offer the same results, vas anastomosis is better done using a CO2 laser system.
An alternative to Nesbit's operation in the treatment of penile curvature is presented. Results in 16 patients are discussed. The procedure does not require removal of tunical tissue, is therefore less invasive than the original operation and produces equally good results.
Bilateral testicular occur in about 5% of patients. The time interval between the diagnosis of the first and second tumor may be more than 10 years. Because the prognosis depends on early detection of the second tumor, longterm follow-up to exclude a contralateral malignancy is mandatory. This article discusses the principle of follow-up of 208 patients with testicular tumors and the treatment of patients with bilateral testicular cancer. The role of ultrasound in the diagnosis of a possible second tumor is emphasized.
Rehabilitation results are reported concerning the behavior of blood pressure and heart rate, peripheral and central hemodynamics, after resting and during exercise and physical conditioning by running as training and sauna, respectively, in hypertensive patients with IHD after aortocoronary venous bypass (ACVB) surgery. Bicycle ergometric examinations an xenon wash-out (for the determination of the mean functional vessel cross section A) were performed in 43 male untrained patients before and after physical therapy. The left ventricular ejection fraction (EF) at rest was also determined in these patients. Significant increases in the ejection fraction at rest (on average by 7-8%) could be demonstrated in both therapy groups. The group average value for peripheral microcirculation improved only in the sauna group. Blood pressure after resting and on exercise was not influenced. Results are discussed on the basis of the literature and practical conclusions drawn.
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The study aimed at evaluating the effect of different methods of digitisation of radiographic films on the digital classification of pulmonary opacities. Test sets from the standard of the International Labour Office (ILO) Classification of Radiographs of Pneumoconiosis were prepared by film digitisation using a scanning microdensitometer or a video digitiser based on a personal computer equipped with a real time digitiser board and a vidicon or a Charge Coupled Device (CCD) camera. Seven different algorithms were used for texture analysis resulting in 16 texture parameters for each region. All methods used for texture analysis were independent of the mean grey value level and the size of the image analysed. Classification was performed by discriminant analysis using the classes from the ILO classification. A hit ratio of at least 85% was achieved for a digitisation by scanner digitisation or the vidicon, while the corresponding results of the CCD camera were significantly less good. Classification by texture analysis of opacities of chest X-rays of pneumoconiosis digitised by a personal computer based video digitiser and a vidicon are of equal quality compared to digitisation by a scanning microdensitometer. Correct classification of 90% was achieved via the discribed statistical approach.
Classification of opacities in pneumoconiosis was accomplished by textural analysis in digitised chest x-rays. A good discrimination was achieved by a set of 10 parameters. These texture measures were computed by algorithms for edge detection, local extremes, difference statistics, the co-occurrence matrix and the power spectrum. The classes of the training set were classified correctly at 99%. A test set comprising additional classes that were not contained in the training set, was classified at 82%.
A case of testicular cancer in 2 brothers is reported and a review of the literature about testicular malignancies and etiologic factors in closely related family members is given. The familial incidence of testicular tumor is found to be 3% in twins and 0.6-2.1% in less closely related men. Tumors were of the same histology in 70-77% of the twins, whereas in brothers and in other degrees of relationship tumors of different histology mostly occur. Following the diagnosis of the tumor in the first man, the average interval to presentation of the tumor in the relative was 3.7 years in twins, 7.7 years in nontwin brothers and 13.5 years for less closely related men. The need for a thorough checkup of other family members is advised.
The induction of transitional cell bladder tumors following portacaval shunt (PCA) in rats was investigated. Thirty-five (29 males; 6 females) out of 86 animals developed a carcinoma. The highest incidence of tumors (73%) was seen in control animals without a PCA but with implantation of a bladder stone. PCA rats had an induction rate of 34% and a spontaneous bladder tumor was seen in 2/13 sham-operated controls. All rats with a bladder tumor also had urolithiasis; 34 rats had bladder stones in 1 rat had kidney stones. The induction rate in males was 29/52, 55.7% compared to 6/34, 17.6% in females. All tumors were transitional cell carcinomas and were graded G0-GIII [1(G0); 24 (GI); 1 (GI-II); 9 (GII)] accompanied in 20 cases by squamous cell metaplasia. Chronic irritation by stones and infection are the most likely causes of tumor development; however, other mechanisms such as excretion of carcinogens or tumor promoters cannot be completely excluded. The sex difference in stone formation - and tumor induction - are subject to further investigations.
From 1967 to 1985, 246 cystectomies for treatment of transitional cell carcinoma of the urinary bladder were performed. Perioperative mortality decreased from 15% in the early years to 0% in 1985. Preoperative radiotherapy was not given. Patients who underwent cystectomy immediately following the diagnosis of invasive bladder carcinoma had a significantly better prognosis than those having cystectomy after recurrence of a transurethrally resected invasive carcinoma in spite of identical G and T criteria. A total of 26 patients who were cystectomized because of tumor recurrence after definitive radiotherapy (salvage cystectomy) represented the group with the worst prognosis: they had a 5-year survival rate of less than 10%. It is concluded from these results that recurrence of an infiltrating bladder tumor is an indication of poor prognosis. Early cystectomy after diagnosis of tumor infiltration can improve survival rates. Transurethral resection without adjuvant therapy cannot be regarded as reliable curative treatment of bladder cancer infiltrating the lamina propria (pT1). Modern surgical techniques of continent urinary diversion or total bladder replacement combined with sparing of the pelvic nerves (and thus preservation of potency) reinforce our view that radical cystoprostatectomy need no longer be regarded as mutilating surgery.