Thirty-eight years of stone meetings in Europe

Of decisive importance for the many research groups all over Europe were the scientific symposia dealing with the theoretical foundations and clinical aspects of urinary stone disease. There were several sources from which today's European Urinary Stone meetings and the "Eurolithiasis Society" itself arose. It was a long way from Leeds in 1968 to Jena 1970, Bonn-Vienna in 1972 and to 11 European meetings from 1989 to 2005. Which developments in urinary stone disease research have been presented at our congresses during the past 40 years? The 1970s and 1980s are the years marked by efforts to measure the important lithogenic substances such as calcium, ionized calcium, uric acid, phosphate, oxalate with reliable methods. Hypercalciuria and specifically mild hyperoxaluria were the topics of numerous investigations in the 1970s, 1980s and 1990s. The calcium-loading test described by Pak has been discussed frequently since its application. It became apparent that oxalic acid is more important in urinary stone formation than hypercalciuria. Of importance were investigations done by Robertson and his colleagues on the influence of diet (in particular, an animal protein-rich diet) on urinary stone formation. Another emphasis of research was investigation of the crystallization process: supersaturation, crystal growth and aggregation are important steps in urinary stone formation. Of great importance in the formation of urinary stones are inhibitors (inhibitory activity): citrate, magnesium, pyrophosphate, macromolecules: GAGs, THP etc. and it became possible in the early 1970s to determine substances such as Tamm-Horsfall protein (THP) and GAGs. Much attention in the 1970s and 1980s was focused on urinary stone analysis (X-ray diffraction, infrared spectroscopy, polarization microscopy) and standardization of these methods. In the mid-1980s, a whole series of epidemiological studies were carried out, with data for the Federal Republic of Germany, East Germany, Czechoslovakia and Austria. The search for "stone-removing" medications, their description and clinical use was the subject of much clinical research and in vitro examinations. A definite advance occurred in the 1980s with the development of new instrumental technologies for the management of urinary stones such as shockwave ("Stosswelle") lithotripsy, percutaneous nephrolithotomy and ureterorenoscopy (" breakthrough innovations"). Since the 8th European Urolithiasis Symposium there have regularly been presentations pertaining to the topic of the molecular basis of inherited lithiasis. The last 10-15 years have shown an increasing turning toward the importance of cellular alterations and supersaturation and their relation to stone formation. In conclusion, I would like to note that it is of decisive importance for the research groups all over Europe to organize scientific symposia dealing with the theoretical foundations and clinical aspects of urinary stone disease under the protection of the European Urolithiasis Society.

Das urologische Fachgutachten im Arztrecht

The role of specialist opinion in medical law (medical standards and the determination of due care) is discussed. The mandator is usually a court of law or an arbitral committee of the general medical council. In comparison to other countries, a specialist opinion is judicially ordered. An increase in the number of patient accusations against the medical practitioner must be shown. The form and preconditions for a urological specialist opinion in medical law are given. The requirements for the specialist are comprehendability, readiness to give objective answers to the questions presented as well as careful research into the development of the illness. Reference is also made to the responsibility of teaching hospitals to provide education on producing a specialist opinion within the framework of specialist training. An overview of the common complications in the diagnosis and therapy of typical urological illnesses, which could lead to medical disputes, is presented. Important sources of error, as well as contravention of the clarification and counselling responsibilities, are presented synoptically.

Renal Tubular Alteration by Crystalluria in Stone Disease – An Experimental Study by Means of MDCK Cells

OBJECTIVES

Physicochemical properties of urine do not explain the formation of urinary stones. Clinical findings and results of animal experiments suggest that alteration to the renal tubular cell plays a key role in the initiation of urinary stone formation. It is not clear whether this is a primarily intracellular alteration of metabolic origin which, after lysis of the renal tubular cell in the lumen, presents a nucleus for the formation of concretions, or whether in the lumen it is tubular cell damage induced by crystalluria that triggers the formation of urinary stones.

MATERIALS AND METHOD

Using Madin-Darby canine kidney cells, the influence of crystalluria on the renal tubular cell was tested in cell cultures. The influence of parathyroid hormone, vitamin D(3), oxalate and calcium concentrations and the extent to which these processes can be inhibited by allopurinol and selenium were investigated.

RESULTS

Calcium oxalate monohydrate crystals produced reproducible damage to the renal tubular cell which was independent of parathyroid hormone and vitamin D(3). The crystalluria-induced effects were unrelated to the oxalate and calcium concentration or the pH. Allopurinol and selenium were able to inhibit the processes.

CONCLUSION

The results indicate secondary involvement of the renal tubular cell in lithogenesis as a result of luminal alteration caused by calcium oxalate crystals. Mechanical damage and interaction between crystal and tubular cell lead to the apposition of crystals. The nephroprotective effect of allopurinol and selenium as antioxidants might explain the benefit of allopurinol found clinically in terms of stone metaphylaxis.

[ImmunoCyt--a new urine test in diagnosis of bladder cancer]

ImmunoCyt is a new immunocytologic fluorescence test promising a higher diagnostic sensitivity, esp. for TaG1 carcinomas. The aim of the study was to evaluate the sensitivity of the test in diagnosis of bladder cancer as compared to both urinary cytology and histopathology. A total of 121 spontaneous urine samples of 92 patients (age range 28 to 86, mean 62.5 years) was examined. 41 of the samples were of patients suspicious of transitional cell carcinoma, 46 of patients in whom symptoms were suggestive of tumor recurrence, and 34 of patients who were part of a follow-up protocol. Cystoscopy was performed in all patients. The ImmunoCyt-test was carried out according to the manufacturers protocol using 3 fluorescent monoclonal antibodies. A total of 113 specimens could be evaluated. In 87 cystoscopy and/or histology was negative (control group). There was histologic evidence of 7 pTaG1, 4 pTaG2, 8 pT1G2/G3, and 7 pT2G2/G3 bladder cancers. As for ImmunoCyt and cytology specificity was 83.9% and 91.9%, resp. The combined specificity was 81.6%. Sensitivity amounted to 38.5% and 34.6%, resp., the combined sensitivity to 53.8%. Sensitivity for TaG1 carcinomas was 14.3% each, for TaG2 carcinomas 25% and 50%, for T1G2/G3 carcinomas 37.5% each, and for T2G2/G3 carcinomas 71.4% and 42.9%, resp. In our study the ImmunoCyt test did not show the expected increase in the detection of TaG1 bladder cancers. Because of false-positive results the test should only be used in combination with urinary cytology which reveals a higher specificity. In conclusion the ImmunoCyt test can not replace cystoscopy (with biopsy) in diagnosis and monitoring of bladder cancer.

[Infection-induced urinary stones]

Infection stones make up approximately 15% of urinary stone diseases and are thus an important group. These stones are composed of struvite and/or carbonate apatite. The basic precondition for the formation of infection stones is a urease-positive urinary tract infection. Urease is necessary to split urea into ammonia and CO(2). As a result, ammonia ions can form and at the same time alkaline urine develops, both being preconditions for the formation of struvite and carbonate apatite crystals. When these crystals are deposited infection stones form. Pathogenetically, various risk factors play a role: urinary obstruction, neurogenic bladder, dRTA, and MSK. If these infections are not treated and the stones are not removed, the kidney will be damaged. Modern methods are available for stone removal, e.g., ESWL and/or instrumental urinary stone removal. Here, especially less invasive methods are preferable. Any treatment must be adjusted to the patient individually. Patients should be examined frequently for recurrent urinary tract infections and stone recurrences, and new infections must be resolutely treated. Good therapy and prophylaxis are possible with present-day treatment modalities.

Urinary infection stones

Infection stones make up approximately 15% of urinary stone diseases and are thus an important group. These stones are composed of struvite and/or carbonate apatite. The basic precondition for the formation of infection stones is a urease positive urinary tract infection. Urease is necessary to split urea to ammonia and CO(2). As a result, ammonia ions can form and at the same time alkaline urine develops, both being preconditions for the formation of struvite and carbonate apatite crystals. When these crystals deposit themselves infection stones form. If these infections are not treated and the stones are not removed, the kidney will be damaged. For stone removal modern methods are available, e.g. ESWL and/or instrumental urinary stone removal. Here especially less invasive methods are preferable. Any treatment must be adjusted to the patient individually. Patients should be examined frequently for recurrent urinary tract infections and stone recurrences and, newly arising infections must be resolutely treated. Good therapy and prophylaxis are possible with present-day treatment modalities.

[Molecular biology of cystinuria]

Cystine stones belong to the kidney stones diseases which are difficult to manage due to the high rate of recidivation and the necessary surgical procedures. Cystinuria is an autosomal recessive defect of the transport of cystine and the dibasic amino acids in the proximal kidney tube. Recently, two subunits of a renal cystine transporter have been identified. Mutations in these genes have been shown to lead to the cystinuria phenotype. Genetic and functional analyses have helped to modify the classification of cystinuria which had previously been exclusively based on biochemical data. Furthermore, first steps towards a molecular genetic testing have been carried out replacing the so far diagnostic procedure which are stressing for the patients. The results of these testings make an individual therapy possible.

Collagen fleece for defect coverage following plaque excision in patients with Peyronie's disease

OBJECTIVES

Surgical correction of penile deviation in patients with Peyronie's disease by tunical plication often leads to shortening of the penis. It is, thus, recommendable to combine tunical plication with plaque incision or excision. The resulting tunical defect, however, requires grafting, and various techniques have been described. In comparison with tunical plication, all of these combined techniques are associated with increased operation time, mainly due to additional procedures necessary at the donor site, and may result in defects at the donor site. We here report a novel surgical technique by which tunical defects after partial excision of plaques are covered by a ready-to-use collagen fleece coated with tissue sealant (TachoComb).

METHOD

A prospective clinical observation trial was conducted in 19 patients with penile deviation due to Peyronie's disease.

RESULTS

In all patients, a reliable closure of the Tunica albuginea was achieved, and no postoperative haematoma formation was observed. Postoperatively, none of the patients suffered from erectile dysfunction. During the follow-up period of 25 months, objective and subjective improvement was 83% and 72%, respectively.

CONCLUSION

The present data indicate that this novel surgical technique may be of benefit in patients with Peyronie's disease and should thus be further evaluated.

Minimally invasive PCNL in patients with renal pelvic and calyceal stones

Stones of the renal pelvis can be treated either by extracorporeal shock wave lithotripsy (SWL) or percutaneous nephrolithotomy (PCNL). As a low-risk procedure with a longer treatment period, SWL often leads to persistent residual stone fragments, whereas conventional PCNL achieves a higher stone-free rate and allows a shorter treatment period albeit with a somewhat higher surgical risk. To reduce the invasiveness of conventional PCNL, the application of a miniaturised instrument for PCNL (MPCNL) was evaluated. For MPCNL a rigid nephroscope with a calibre of 12 F was developed and used in 19 patients. After puncture of the kidney under ultrasound control and single-step dilatation, a 15 F Amplatz sheath was placed. Data on the stone size and location, stone-free rate, blood transfusions, operating time and complications were recorded. In all patients, the part of the kidney afflicted by the stone was successfully punctured. On average, retreatment rate was 0.7. The mean stone size was 2.4 cm(2). The average operating time was 99.2 min. In every case, the absence of residual stones was confirmed radiologically and nephroscopically. Hemorrhages requiring a blood transfusion did not occur. A febrile pyelonephritis occurred as a postoperative complication in one patient (= 5.3%). MPCNL represents an alternative to SWL for renal calculi with a size from 1 to 2 cm located in the renal pelvis and calices, especially the lower calix. The advantages are the short treatment time, the high stone-free rate and the accessibility of lower pole stones which are less amenable to SWL. MPCNL is not suitable for large concrements since the limited sheath diameter would increase the operating time. Due to this limitation, MPCNL represents an extension of the indication for conventional PCNL that it can in no way replace.

Comparison of cytology and nuclear matrix protein 22 for the detection and follow-up of bladder cancer

OBJECTIVES

This study was designed to determine the clinical usefulness of the nuclear matrix

METHODS

84 patients suffering from bladder cancer or suspected bladder cancer, 25 patients with benign urological lesions and 60 healthy controls participated in a prospective study. Freshly voided spot urine samples were taken for cytological examination and determination of NMP 22 levels by enzyme-linked immunoassay.

RESULTS

The sensitivity of the NMP 22 test according to the tumor grading was (results of cytology in brackets): G1 25.0% (20.0%); G2 68.2% (59.1%), and G3 100.0% (66.7); overall sensitivity was 62.5% (45.0%). The sensitivity for superficial bladder cancer was 46.7% (36.7%) and for invasive bladder cancer 90.0% (70.0%). The specificity was 65.9% (88.9%).

CONCLUSIONS

NMP 22 is a reliable tool for detecting invasive bladder cancer. Results for the frequently occurring low grade superficial bladder cancer are as poor as those obtained with cytology. In addition benign lesions such as urolithiasis or urinary tract infection lead to false-positive results. Therefore cystoscopy has to be performed when trying to detect and follow-up bladder cancer.

Comparison of symptoms, morphological, microbiological and urodynamic findings in patients with chronic prostatitis/pelvic pain syndrome. Is it possible to differentiate separate categories?

164 patients with prostatitic symptoms were evaluated by segmented urinalysis and culture and classified according to the National Institutes of Health classification system: 64 patients (38%) suffered from chronic bacterial prostatitis; 12 (7%) from inflammatory chronic pelvic pain syndrome, and 92 (55%) from non-inflammatory chronic pelvic pain syndrome. Transrectal ultrasound of the prostate, uroflowmetry and measurement of residual urine were also performed. Complaints were recorded using a questionnaire. Our studies revealed that leukocytes in expressed prostatic secretions could be detected in only 24 and 36% of patients with positive bacterial or chlamydial culture. Complaints, ultrasound and urodynamic findings were similar in the 3 groups. Therefore the differential diagnosis and therapy, based on the results of the 4-glass test and cultures as well as on transrectal ultrasound of the prostate, seem to be difficult.

Schistosomiasis: a critical review

Precise data on epidemiology, morbidity, post-treatment resolution, reinfection, and resurgence of schistosomiasis could be helpful in establishing purposeful treatment plans for the disease in endemic populations. Here we give a concise overview of recent publications on bilharziasis. A main emphasis is placed on studies on the prevalence of schistosomiasis, partly including long term surveillance of morbidity following treatment with praziquantel. As genito-urinary schistosomiasis may be a risk factor for the spread of HIV, the involvement of the reproductive tract has become another focus in research on the disease. A novel diagnostic tool, eosinophil cationic protein (ECP), is proposed to correlate with the degree of inflammation of the genito-urinary tract.

Arterial blood pressure following different types of urinary stone therapy. Presented at the 8th European Symposium on Urolithiasis, Parma, Italy, 1999

OBJECTIVE

Several studies reported increased blood pressure (BP) values following extracorporeal shock wave lithotripsy (ESWL) treatment of renal stones. It is unclear, however, whether this is due to ESWL, since nephrolithiasis itself increases the relative risk of developing hypertension. Therefore we prospectively studied the BPs of stone patients undergoing different types of treatment.

METHODS

252 stone patients (63% males, 37% females, median age 44.3, range 11.7-86.4 years) participated. 168 suffered from uretral stones: 50 underwent ESWL; 40 ureteroscopy, and 78 patients passed stones spontaneously (SP). 84 had renal stones: 60 underwent ESWL; 8 percutaneous nephrolithotomy/open surgery, and 16 no treatment. Systolic (SBP) and diastolic (DBP) BP were measured according to Riva-Rocci prior to, immediately after, and 3, 6, 12, 18 and 24 months after stone therapy.

RESULTS

Immediately after SP, SBP decreases, whereas after active stone treatment increases (highest after ESWL) in SBP were seen. DBP was unchanged. During the further follow-up, a gradual increase in BP was observed in all groups. At 24 months in all groups, regardless of the stone location and type of treatment, SBP and DBP were significantly higher than the pretreatment levels (p = 0.000). There was no a difference between renal and ureteral stones, or between the ESWL treatment and the other groups.

CONCLUSION

Renal stone disease itself rather than the type of treatment significantly increases SBP and DBP during a follow-up period of 24 months. The underlying mechanisms remain to be elucidated.

Immunohistochemical examinations (Ki67, p53, nm23) and DNA cytophotometry in bladder cancer

Bladder cancer is clinically characterized by a high recurrence rate for superficial tumours up to 70% and by the invasiveness of advanced bladder cancer. To learn more about the biological behaviour of an individual bladder cancer different tumour markers have been investigated. The aim of our study was to compare the potential of aggression of both superficial and invasive bladder tumours by means of the proliferation marker Ki67, the tumour suppressor gene p53, the non metastasizing protein nm23 and the evaluation of DNA ploidy. We examined 36 patients, 28 with a bladder tumour (Ta-T4) and 8 without as a control group. For immunohistochemistry (Ki67, p53, nm23) we took paraffin sections and scored semiquantitatively under a microscope. The DNA cytophotometry was done on bladder washings by evaluating the DNA ploidy of single cells. The results showed that benign tissues were negative for Ki67 and p53 but positive for nm23. The DNA diagnosis was diploid for all benign samples. The superficial bladder cancer (Ta, T1) showed, in comparison to the invasive tumours, significantly lower numbers of aneuploid cells and a higher rate of p53 mutations. On the other hand the invasive tumours (T2-4) were correlated to significantly higher proliferation rates and higher potencies for metastasizing. The combination of the investigated tumour markers allowed a graduation of the biological behavior of an individual bladder cancer. Especially a high p53 mutation rate and a non aneuploid DNA diagnosis were indicators for the recurrence of superficial bladder tumours. Invasive growth of bladder cancer was characterized by high Ki67 proliferation and low nm23 protein binding.

Molecular genetic methods in the diagnosis of invasive bladder cancer

Development and progression of tumours is generally driven by an accumulation of genetic alterations. In this study we correlated chromosome 17 aneuploidy to invasiveness of bladder cancer by the method of fluorescence in situ hybridisation (FISH) in urinary cytospins. We investigated the value of FISH compared to DNA cytophotometry in the diagnosis of bladder cancer. 39 patients with or suspicious for bladder tumour were analyzed. 19 patients had a bladder tumor at the time of diagnosis, 14 superficial (Ta-T1) and 5 invasive (T2-3). The remaining 20 patients had no tumour at the time of diagnosis, however 9 of them had one in prehistory (Ta-T2). For FISH we used the DNA probe of HER-2/neu located on chromosome 17. DNA image cytometry was performed according to single cell interpretation of Böcking. Our results showed a correlation between HER-2/neu CEP 17 alterations and invasive bladder cancer to the extent of 10-70% aberrant cells for patients with current invasive bladder tumour as well as for patients who had been cured but with as invasive bladder cancer in prehistory. On the other hand, the percentage of aneuploid cells for negative biopsy and superficial tumour was 0-2%. The DNA cytophotometry brought an uniform aneuploidy only for present invasive tumours: negative biopsies, superficial cancer and invasive tumour just in prehistory, showed mixed diploid-aneuploid DNA patterns. Our results showed that for the detection of aberrant tumour cells the method of FISH is more sensitive than DNA cytometry. FISH could provide important information in the prognosis of bladder cancer.

Serologic angiogenesis factors and microvascular density in renal cell carcinoma: two independent parameters

Renal Cell Carcinoma (RCC) is characterized by high intratumoral microvascular density (iMVD) and significantly elevated serologic titers of angiogenesis factors, basic fibroblast growth factor (bFGF), vascular endothelial growth factor (vEGF) and angiogenin (Ag). The goal of the present study was to find whether a correlation exists between any of these factors and intratumoral microvascular density (iMVD). Serologic angiogenesis factors were determined directly before nephrectomy of a tumorous kidney in 12 patients (average age: 67.6 years [49-78] with localized clear-cell RCC (Robson I-II) (Quantikine', R&D Systems Europe, Abington, UK). Sections were taken in each case from the microscopically most aggressive area of the tumorous kidney preparations. Staining was carried out with a primary antibody against CD31 (DAKO M 0823, Hamburg, Germany). iMVD was counted at 160x magnification at five "hot spots" 200 x 200 microns in size, and the individual factors were then correlated with the areas of maximum and average iMVD (iMVDmax, iMVD-d). Average concentrations of 38 pg/ml +/- 68 were found for bFGF, 712 pg/ml +/- 791 for vEGF, and 358 ng/ml +/- 97 for Ag. iMVDmax was 20 +/- 11 per area, iMVD-d was 410/mm2 +/- 243. No correlation was found between microvascular density and serologic angiogenesis factors for any parameter. Actual tumor vascularization, expressed as iMVD, was not correlated with the 3 angiogenesis parameters which were studied. On the one hand, this raises the question whether angiogenesis can be measured at all with these parameters; on the other, it remains nuclear whether the continuous process of angiogenesis can be registered at all by chronologic, specific factor analysis.

[Early detection of prostatic carcinoma in urologic practice with digital rectal examination and prostate-specific antigen. Early Detection Project Group]

For the early detection of prostate cancer, a patient should undergo digital rectal examination (DRE) and PSA investigation. Follow-up of increased PSA levels detects nearly 80% of cancers. Positive predictive value of suspicious DRE and PSA is about 50%. Whereas in the first evaluation of this case-finding trial about 70% of the patients had organ-confined cancers, nearly all of the detected cancers in the follow-up investigation were organ confined. The increased number of organ-confined cancers detected in early periodical examinations can lead to a reduction of mortality and morbidity from prostate cancer.

Reduction of high-energy shock-wave-induced renal tubular injury by selenium

In shock-wave-induced renal injury cavitation-generated free radicals play an important role. Using an in vitro model with Madin-Darby canine kidney (MDCK) cells, we investigated the influence of selenium, a free radical scavenger, in shock-wave-induced tubular cell injury. Suspensions of MDCK cells (33 x 10(6) cells/ml) were placed in small containers (volume 1.1 ml) for shock wave exposure. Two groups of 12 containers each were examined: (1) control (no medication), (2) selenium (0.4 microg/ml nutrient medium). Six containers in each group were exposed to shock waves (impulse rate 256, frequency 60 Hz, generator voltage 18 kV), while the other six containers in each group served as a control. After shock wave exposure, the concentration of cellular enzymes such as lactate dehydrogenase (LDH), N-acetyl-beta-glucosaminidase (NAG), glutamate oxaloacetate transaminase (GOT) and glutamate lactate dehydrogenase (GLDH) in the nutrient medium was examined. Following shock wave exposure there was a significant rise in LDH, NAG, GOT and GLDH concentrations. Selenium reduced this enzyme leakage significantly. Thus we conclude that selenium protects renal tubular cells against shock-wave-induced injury. Since selenium is an essential part of glutathione peroxidase, this effect seems to be mediated by a reduction in reactive oxygen species.

Mutations in the SLC3A1 gene in cystinuric patients: frequencies and identification of a novel mutation

Cystinuria is a frequent autosomal recessive transport disorder characterized by defective renal resorption of cystine and other dibasic amino acids. Biochemically, three types of cystinuria can be defined. Here we present our results of screening for mutations in the SLC3A1 gene, which codes for a dibasic amino acid transporter protein and appears to be involved in the pathogenesis of cystinuria type I. Our study population consists of 5 Italian cystinuria type I patients and 10 cystinuric patients as yet unclassified as to clinical type. The latter were of different ethnic origin. In total, we found 13 point mutations and 8 genomic rearrangements in 15 cystinuric patients, i.e., our detection rate was 70% (23/30 chromosomes). Remarkably, in patients known to be suffering from cystinuria type I, the mutation detection rate was only 50%, whereas in patients unselected as to cystinuria type, we found 80% of mutations. Additionally, our results, as with those published in the literature, indicate a possible population specific distribution of mutations: Each of the 4 Greek patients analyzed here showed homozygosity for mutation T216M in exon 3. Analysis of a Yugoslavian patient showed homozygosity for a novel mutation, R365L, in exon 6 (nt1094G > T). Findings from molecular genetic studies, as well as physiological investigations, suggest that there are further genes that play a role in the etiology of cystinuria. Nevertheless, our results show that screening for mutations in the SLC3A1 gene can be a meaningful step toward molecular genetic diagnosis of cystinuria in patients without biochemical classification. As with cystic fibrosis, the finding of specific mutations in particular ethnic populations, suggest that the diagnostic approach should take into consideration a patient's ethnic origins.

Immunohistological investigations of carcinoembryonic antigen (CEA) in urothelial carcinomas

CEA is discussed as a potential tumour marker for carcinomas of the urothelium. However, investigations by means of polyclonal antibodies have shown various cross reactions which are not to be expected with monoclonal antibodies (MAb). Immunohistochemistry was done with the MAb anti-CEA BW 431/26 (Behring), N 1522 (Dako), and C 7292 (Sigma) on 37 carcinomas of the urothelium (grades 1-3). The MAb BW 431/26 showed the best results concerning specificity and sensitivity. In general, immunohistological investigations demonstrated negative or moderate staining reactions. Positive reactions were seen in 32% (12/37) of the carcinomas. Staining intensity for CEA correlated with differentiation grade. On the whole, a maximum of 5% of the tumour cells were CEA positive. Our results indicate that monoclonal anti-CEA antibodies are not usefull as a tumour marker for urothelial carcinomas. For the suitability of CEA for in vitro and for in vivo diagnosis a threshold of CEA positive tumour cells has to be defined.

Control of hepatic parameters in renal cell carcinoma (RCC) by interleukin-6 (IL-6)?

RCC can go hand-in-hand with an elevation of various hepatic proteins. An interrelationship between the IL-6 titer, C-reactive protein (CRP) and the blood sedimentation rate (BSR) has already been proven. The aim of the present study was to study 1) the possibility of differentiating between healthy and RCC patients via IL-6 in the serum and 2) the relationship of IL-6 to hepatic parameters {alkaline phosphatase (AP), gamma-glutamyltransferase (gGT), serum proteins (E'p)} and the usual clinical prognostic parameters (tumor grading, staging). Serum analysis of 38 healthy patients via ELISA (DPC-Biermann, Germany) showed normal values of 1.2 ng/ml for IL-6, with a standards deviation of +/- 1.7 and a peak concentration of 3 ng/ml (specificity: 95%). In 20 RCCs there were IL-6 titers of 10.7 ng/ml +/- 6.56 in the pre-operative serum. The sensitivity of IL-6 was about 90%. The difference was statistically significant (p < 0.0001, Wilcoxon test). For IL-6 there was a positive correlation with the BSR (1-hour value: r = 0.7; 2-hour value: r = 0.6), CRP (r = 0.85), E'p (r = 0.6), and gGT (r = 0.6). No correlation was found between AP, the Robson stage, grading, and IL-6. IL-6 is potentially suitable for differentiating between healthy and RCC patients but is not tumor specific. IL-6 has a strong correlation with all laboratory values which were analyzed except AP thus there is considerable evidence for a cytokine (IL-6) control of the hepatic changes. Since some of the above-named laboratory parameters have prognostic relevance, IL-6 can be regarded as a cumulative prognostic parameter.

Marker for renal cell carcinoma (RCC): the dimeric form of pyruvate kinase type M2 (Tu M2-PK)

OBJECTIVE

The evaluate a potential tumor marker for RCC. Tumor formation is generally linked to an expansion of glycolytic phosphometabolite pools and aerobic glycolyticflux rates. To achieve this, tumor cells generally overexpress a special glycolytic isoenzyme, termed pyruvate kinase type M2. To establish the expansion of phosphometabolite pools pyruvate kinase switches between a tetrameric form with high phosphoenol-pyruvate (PEP) affinity and a dimeric form with a lower PEP affinity. The dimeric form is predominant in all tumors that have been investigated and has been termed TuM2Pk.

MATERIALS AND METHODS

We studied: a) the expression of TuM2Pk in RCC by immunohistochemistry using a monoclonal antibody recognizing only the mono- or dimeric form of pyruvate kinase, b) the stability of TuM2Pk in serum by measuring TuM2Pk in 3 patients at different times after taking blood with a two-site immunometric assay, c) the a circadiane rhythm of TuM2Pk in blood by measuring levels every 4 hours in 5 patients, d) TuM2Pk- expression in serum (see 2.) in 5 patients by taking blood from tumor-side vena renalis compared to peripherally blood, e) TuM2Pk (see point 2.) in 40 RCC-patients comparing the results with 39 healthy persons and clinical data of RCC, f) the influence of wound healing to TuM2Pk by measuring serum-levels during a period of more than 12 weeks in 6 patients, g) the individual follow up of 4 patients with RCC stage Robson III for more than 2 years. Comparing TuM2Pk-levels to findings of staging by computed tomography.

RESULTS

The isoenzyme TuM2Pk could be demonstrated in RCC and their metastases by immunohistochemistry with a monoclonal antibody specific for pyruvate kinase type M2. In normal kidney cells pyruvate kinase type M2 is not detectable. The stability of TuM2Pk was studied in the serum within 30 minutes. No circadian rhythm was found. Most serum TuM2Pk comes from tumor. Serum evaluation in 39 healthy persons was used to determine normal values, with an upper concentration of 28 U/ml of TuM2Pk (95% percentile of normal healthy persons). Serum evaluation in 40 RCC showed a significant difference to healthy persons and a positive correlation with Robson stage and grading No correlation of TuM2Pk was found with histopathological cell type of tumor diameter. After radical nephrectomy normalization of TuM2Pk level was found within 11 weeks in all localized RCC. Continuously elevated serum levels were seen in metastatic RCC. Individual follow-up seems to be possible.

CONCLUSION

Initial discrimination is not possible between localized and metastasized RCC using TuM2PK; however, it is possible to differentiate between benign and malignant renal processes; the specificity under these circumstances is 75%. After successful surgery of localized RCC, an elevated TuM2Pk will be normalized within 11 weeks, and will be remain elevated or will increase again in case of RCC-relapse or metastasis. Thus TuM2Pk would appear to be a useful marker for RCC detection and follow-up.

Renal cell carcinoma: relevance of angiogenetic factors

Angiogenesis is essential for tumour growth. Mostly hypervasculariced renal cell carcinoma (RCC) usually express angiogenic factors, e.g. basic fibroblast factor (bFGF), vascular endothelial growth factor, and angiogenin (ag). This study was designed to evaluate the improvement of serological angiogenesis-factors, their prognostic relevance and correlation to tumour-grade, -stage and -volume. Measurement of bFGF, vEGF and ag was done with ELISA (Quantikine), R and D-Systems Europe Abbington, United Kingdom. The control group comprised 39 healthy blood donors, RCC-group were 35 patients with different RCC. Survival dates were presented with Kaplan-Meyer-curves, significance was tested with students-t-test. For all angiogenic factors a highly significant difference between the healthy and RCC-group was found. A strong correlation between angiogenic factors and tumor grade, -stage and -volume, was not found, but a trend for each of the angiogenic factors to correlate with grade was seen. No survival benefit was seen between patients with normal angiogenic factor over those with elevated angiogenic levels.

The problematic nature of metastasized renal cell carcinoma

The treatment of metastatic renal cell carcinoma presents major unsolved problems. All of the therapeutic options have shown only minimal success rates. In addition to partial clarification of tumour genesis, basic findings regarding the heterogeneity of tumors were made. Options for further therapeutic developments will result from increased knowledge of the pathogenesis of metastatic spread. After the growth of new tumor vessels (angiogenesis) the metastasizing cell must break away from the cell formation (loss of cadherines). By migration it reaches the vessel wall which is made permeable by proteolysis (matrix metaloproteinase). After reaching the target organ, adhesion results (adhesion molecules and integrins) within the vessel system and ex-travasation follows. With stimulation the metastatic cell will grow in the target organ. Growth is subject to the cytokine control mechanism (interleukines). Based on these individual steps, future therapeutic options can be developed. However, the treatment modalities at our disposal today must not be neglected: for example, immuno(chemo)therapy and various radiation therapies as well as metastases surgery.

DNA cytophotometry in renal cell carcinoma: a significant prognostic factor?

We report on a prospective DNA cytophotometric study of 66 patients with renal tumors, 61 of whom had renal cell carcinoma (RCC) (pT1-pT4, G1-G3). 16 of the patients had a metastasis at the time of diagnosis. Cell material from 1-5 specimens of each tumor was analyzed for intratumoral heterogeneity. The aim of the study was to evaluate the prognostic value of the following DNA parameters: DNA ploidy, DNA grade of malignancy (DNA MG), mean DNA, DNA index, 2c deviation index (2cDI), and 5c exceeding rate (5cER). In this study 21% of the tumors were non-aneuploid, 79% were aneuploid; however, it proved possible to diagnose 38% of the total collective as aneuploid only by analyzing several tumor areas. In five of 61 RCC patients who died during an observation period of 42 months, at least one area of the primary tumor was aneuploid. Aneuploid primary tumors also accompanied the development of metastases and recurrent tumors in four of the 61 RCC patients. Only DNA 2cDI was found to have a significantly positive clinical correlation with metastasis (r = 0.261) during the clinical course. This was not true, however, for the histopathologic parameters. Significantly positive correlations were found between the tumor stages and the following DNA parameters: mean DNA, DNA index, and 5cER. Histopathologic tumor grading showed a significantly positive correlation with DNA MG, mean DNA, and 5cER. Statistically, the mean values of all evaluated parameters were significantly higher in metastasizing and recurrent RCCs than in non-metastasizing carcinomas (p < 0.05; t-test). DNA cytophotometry cannot substitute histopathologic prognosis. However, the analysis of various DNA parameters helps considerably in evaluating both the malignant potential of kidney tumors and the benign parenchyma of tumor-bearing kidneys.

Renal cell carcinoma: immunohistological investigation of expression of the integrin alpha v beta 3

alpha v beta 3 Integrin has been shown in various tumor entities to promote binding to superficial structures of the basement membrane during metastasis. The goal of the present paper was a structural demonstration of this Integrin in renal cell carcinoma (RCC). After removal of paraffin from formalin-fixed tissue, the cells were labelled with the antibody (VNR 147, H. Biermann, Bad Nauheim) using the peroxidase-antiperoxidase method (DAKO Diagnostical GmbH, Hamburg). Evaluation was carried out microscopically and semiquantitatively from missing (-) through moderate (+) to strong (+2) staining. A total of n = 79 RCCs and n = 53 healthy areas were examined. Semiquantitative staining results: there was a grading-dependent increase (+2) of stainability and thus alpha v beta 3 expression. Two of 53 benign specimens showed strong staining, 11 of 53, only weak staining. Four of 18 G1 RCCs showed strong staining, 11 of 18 only weak staining. Results for G2-RCCs: 11 with strong staining, 21 of 40 with weak staining. G3-RCCs: 4 with strong staining, 2 of 7 with weak staining. Of the metastases, on the other hand, 2 of 14 showed strong staining, another 8 of 14 only weak staining. There were no deviations within the histologic (clear-cell, chromophil, or chromophobe) subpopulations. This grading-dependent expression permits the conclusion that the probability of binding to the human basement membrane mediated by alpha v beta 3 Integrin rises with increasing grading, but the already metastatic cell exhibited this Integrin less strongly, since a basement membrane adhesion is no longer necessary for this cell group.

Loss of chromosomes in clear cell renal cell carcinoma and in corresponding renal parenchyma

Chromosome studies were done on six renal cell carcinomas (RCC) and on the corresponding renal parenchymas of the tumor bearing kidneys. Histopathologically, all tumors belonged to the clear cell subtype. All examined parenchymas were pathologically benign. None of the tumor cells showed the typical chromosomal aberrations described for (nonpapillary) RCC, i.e. deletions in the short arm of chromosome #3, or gains in the long arm of chromosome #5. In our series both the tumor and the benign kidney tissues were characterized by loss of chromosomes, especially of the chromosomes #6, #9, #16, #20, and of the Y chromosome. Trisomy of chromosome #7 was found frequently in benign parenchyma cells. The identical chromosomal changes in the tumor and in the parenchyma tissues might reflect rather in vivo mosaics rather than primary chromosomal aberrations in the oncogenetic process of clear cell RCC.

Treosulfan in the treatment of metastatic renal cell carcinoma

BACKGROUND

Treosulfan is a bifunctional alkylating cytostatic agent that has mainly been used in the therapy of advanced ovarian cancer. Lately, a growth inhibiting effect could be detected in human renal cell carcinoma-cell lines as well. In vitro, Treosulfan showed an even higher growth inhibition than Vinblastine.

MATERIALS AND METHODS

We performed a small clinical phase II study using Treosulfan as a monotherapy in the treatment of metastatic renal cell carcinoma. Treosulfan was given to 15 patients with bidimensionally measurable metastases.

RESULTS

10 patients were evaluable. Side effects were negligeable. A complete or even partial remission was not seen. 4 patients showed no change, whereas 6 were progressive. The average time to progress was short (4 months, range 1 to 12 months).

CONCLUSIONS

Since Treosulfan did not lead to a measurable tumor remission in the given dose regimen, it does not seem to be suitable for the therapy of metastatic renal cell carcinoma.

[Early recognition of prostate carcinoma. Initial results of a prospective multicenter study in Germany. Project Group for Early Detection DGU-BDU Laboratory diagnosis Professional Circle]

To compare the efficacy of digital rectal examination (DRE) and serum prostate specific antigen (PSA) in early detection of prostate cancer, we initiated a prospective multicenter screening trial. In 12,542 men choosen at random with a mean age of 62 (+/- 7.5) a suspect DRE or a PSA level > 4.0 ng/ml was found in 2343 (20%). Of the presently performed 744 biopsies, 157 revealed diagnosis of prostate cancer. Although further biopsies as well as the follow up of the 12,542 men are still missing, combination of DRE and PSA value > 4.0 ng/ml appears to be superior to DRE alone with a positive predictive value of 50% versus 19% in early detection of prostate cancer.

Follow-up in prostate cancer patients: which parameters are necessary?

AIM

In a retrospective study we examined whether follow-up of prostate cancer (PC) patients can be managed by using prostate-specific antigen (PSA) as a unique tool as postulated recently.

PATIENTS AND METHODS

According to strict criteria established in the eighties, at our institution PC patients were monitored by PSA, prostatic acid phosphatase (PAP), alkaline phosphatase (AP), digital-rectal examination, renal and bladder ultrasound every 3 months, abdominopelvic computerized tomography (CT) and bone scan every 6 months. Between 1988 and 1994, 80 patients with PC cancer were eligible (mean follow-up 29.5, range 12-81 months). Patients were categorized into 4 groups: localized tumor (n = 44); lymph node metastases (n = 9); distant metastases (n = 18), and lymph node and distant metastases (n = 9). The parameters mentioned were compared for the assessment of progression, regression and stabilization of the disease.

RESULTS

Our examinations showed that PSA is superior to all the other parameters used. In all groups, there were no patients with progressive disease detected by PAP, AP, CT and bone scan, but not by PSA. PSA anticipated the other parameters in detecting progression by several months. Renal ultrasound, however, detected new hydronephrosis in 6 patients with stable or decreasing PSA. Hydronephrosis was caused by surgery or radiotherapy, not by progressive PC.

CONCLUSION

PSA can be used as a unique tool in the follow-up of PC patients in all stages. However, patients who underwent therapy potentially afflicting the urinary tract should have additional renal and bladder ultrasound.

[Collagen metabolism in induratio penis plastica (IPP)]

The exact pathogenesis of Peyronie's Disease (PD) is still unknown. Histopathological investigations suggest, that the metabolism of the collogenious tissue plays an important role. Therefore, we started a prospective study in order to evaluate the metabolic situation of 11 patients with PD and 11 healthy controls. We measured biochemical parameters of penile and venous blood, which correspond to the collagen metabolism (procollagen III [P III P], PMN-elastase [PMN-E], fibronectin [FN], fibronectinreceptor [FN-R] und alpha-1-proteinase-inhibitor [alpha-1-PI]). There was no difference in PMN-E, P III P, FN and FN-R in all samples. There was no difference in penile and venous blood as well. But we found out a highly significant lower concentration of alpha-1-PI in patients with PD (158,55 mg/dl) than in controls (214,82 mg/ dl). A deficiency of alpha-1-PI can lead to a higher activity of serum proteases, such as PMN-E. This can result in a change in collagen metabolism by an increased synthesis of collagen type III, that is found in PD. This general pathophysiologic factor may be competed by an additional local alteration of the tissue.

Indications for open stone removal of urinary calculi

In a retrospective study we analyzed patients undergoing open stone removal in the Department of Urology of the University of Tübingen. In 2.7% of all urinary calculi, open stone surgery was necessary. Open operation was performed on all patients with complete staghorn calculi as well as on patients with renal pelvic stones and simultaneous morphological obstruction. Partial staghorn calculi were operated on only after endoscopic treatment had failed. Small renal pelvic stones and ureteral stones were surgically removed only after extracorporeal shock wave lithotripsy (ESWL) and endoscopic surgery had been unsuccessful. The treatment of choice for ureteral calculi is ESWL. If ESWL is impossible, an endoscopic approach is advisable. Open operations of ureteral calculi only have to be performed if endoscopic therapy has failed or if there is a simultaneous morphological obstruction. Meta-analysis of publications from 1981 to 1995 confirmed our approach regarding indications for open stone removal. Comparison of the results reported in the literature is very difficult because of the missing, but generally accepted definition of stone free. In addition different examination techniques to determine the status 'stone free' make it difficult to compare the various studies.

Spot urine samples for the metabolic evaluation of urolithiasis patients

OBJECTIVES

This prospective study was initiated to assess the significance of spot urine specimens (SU) for the metabolic evaluation of stone formers.

METHODS

68 stone patients (51 males, 17 females) and 20 controls (9 males, 11 females) participated. On 3 consecutive days, urine was collected. Fasting (SU1) and postprandial (SU2) SU were obtained. From these, aliquots were taken, all the other urine was mixed to obtain 24-hour timed specimens (24hU). In all specimens, pH, specific gravity, creatinine, calcium, magnesium, phosphate, citrate, uric and oxalic acids were measured. The latter analytes were related to creatinine (mmol/g creatinine). Pearson correlation coefficients with their levels of significance and the day-to-day variation were calculated. Using the values in the control group, normal values (means +/- 2 SD) were established.

RESULTS

There was a significant correlation (p < 0.0001) between SU and 24hU for all parameters examined. The day-to-day variation of all analytes was considerable in SU and 24hU.

CONCLUSIONS

Despite a minor inaccuracy by relating parameters to creatinine, SU are sufficient in the routine metabolic evaluation of stone formers, since a third of all 24hU has to be rejected because of considerable collection errors. SU circumvent this problem. Because of the day-to-day variation, 3 SU should be obtained to overcome the doubtful significance of one single specimen.

Free PSA in the detection of prostatic carcinoma

A new possibility for improved differentiation between malignant and benign prostatic disease is the determination of free-PSA in the indifferent grey area of total PSA between 2 and 30 ng/ml. In a retrospective study of 106 men with a total PSA between 2 and 30 ng/ml we studied the ratio of free to total PSA. The differentiation between prostatic carcinoma (PCa) and benign prostatic hyperplasia (BPH) was verified by randomised biopsies. PSA was measured with Tandem-E, Hybritech, USA and free-PSA with Tandem-R, Hybritech, USA and Immunite-R, DPC-Biermann, USA. Patients (pts.) with an untreated, virgin PCa releaved a highest quotient free-PSA/PSA lower than 0.25. The highest quotient in pts. with treated PCa was 0.51 and in pts with BPH was 0.52. Therapy of PCa with LHRH-analogues changed free-PSA toward a BPH-profile. Both kits used for free-PSA gave similar results. Our study suggests, that every free-PSA higher than 25% of PSA should not be a valuable, supplementary parameter for pts. with unclear diagnosis.

[Significance of "clinically insignificant residual fragments" (CIRF) after ESWL]

Almost 75% of all urinary calculi can be treated by extracorporeal shock wave lithotripsy (ESWL). In contrast to endoscopic and open-surgical procedures the patients are not immediately free of stones. The residual fragments after ESWL are called clinically insignificant residual fragments (CIRF), if the fragments are less than 5 mm in size and if there is the possibility of a spontaneous passage. But CIRF can cause ureteral obstruction. In addition, CIRF play an important role for the risk of stone growth and stone recurrence. The metaanalysis shows that it is not advisable to classify the CIRF only by their size. The morphological conditions of the urinary tract also have to be evaluated. Therefore, stone patients with CIRF after ESWL require a close follow-up and timely adjuvant therapy. All aspects mentioned lead to the conclusion to use the term "CIRF" with caution.

Skeletal alkaline phosphatase: a marker for individual follow-up in patients with advanced prostatic cancer

Skeletal alkaline phosphatase (sAP) is a tumor marker indicating osseous metastases, e.g. of prostate cancer. Sera of healthy men and patients with benign prostatic hyperplasia (BPH), localized and advanced prostatic cancer (PCa) were analyzed with Tandem-R-Ostase and prostate-specific antigen (PSA). No significant differences were found in sAP levels between healthy men and patients with BPH and localized PCa, but there was a significant difference with the group of patients with advanced PCa. In some cases, the individual follow-up was better and earlier with sAP compared to PSA. It is possible to discriminate between localized and advanced PCa with sAP. The individual follow-up shows in 30% of patients with advanced PCa an earlier increase in sAP, compared to PSA, during progression of disease.

[Studies of calcium metabolism in patients with hypercalciuria]

The different subgroups of hypercalciuria cannot be separated clearly by the Pak calcium-load test. To improve the diagnosis and therapy we examined all relevant parameters of calcium metabolism in 32 patients with calcium urolithiasis and hypercalciuria (> 6.25 mmol/day). We also conducted bone mineral density measurements as well as the Pak calcium-load test. In most cases the pathophysiological constellations which Pak takes as the basis for his classification of hypercalciuria could not be shown. To date, diagnostics only insufficiently explains the genesis of hypercalciuria (except pHPT). As a consequence, a therapeutic problem arises: a low-calcium diet should not be generally recommended, since some patients may develop osteopenia. From our investigation the following diagnostic and therapeutic conclusions can be drawn: (1) Hypercalciuria in primary hyperparathyroidism should be treated by surgical removal of the adenoma. (2) The parathormone-independent osteogenic form should be treated with thiazides. (3) Hypercalciuria with increased 1.25-dihydroxyvitamin D should be treated by low-calcium diet.

Investigations on bone metabolism of urological tumors forming metastases

Bone metastases of urological tumors occur in nearly 40% of all primary tumors of the prostate, the kidney and the bladder. The quality of metastases may be described as osteolytic, osteoplastic or mixed lesion. Whereas prostate cancers produce mainly osteoplastic lesions, renal cell carcinomas predominantly generate osteolytic lesions. In bladder cancer both forms of metastases occur in tantamount numbers. However, diagnostics still presents many difficulties, since it is not feasible to identify very small metastases until symptoms have manifested themselves. The purpose of our study was to evaluate measurement technique and classification of significant serum markers for monitoring the course of disease. Patients with primary urological tumors and metastases in the skeleton were investigated and compared with healthy volunteers. Osteodensitometry was used to confirm and to replace radiological diagnosis of bone metastases. Thus it was possible to locate the extent and obtain information on the maximum charge and the stability of metastases. Our examinations revealed that distinct serum markers describe the changes in bone evoked by metastases. In comparison with healthy volunteers, patients with osteoplastic lesions and osteolytic lesions showed increases in hydroxproline and pyridinium crosslinks (significance at least p < 0.005). Osteocalcin was elevated only in osteoplastic lesions versus healthy volunteers (p < 0.01). For diagnostics of osteoplastic and osteolytic metastases, either alkaline phosphatase or the skeleton-specific phosphatase (ostase) can be measured serologically. Both parameters showed significant elevation in the patient groups when set against the healthy controls (both p < 0.0001). Compared with lytic lesions osteoplastic carcinomas revealed significant increase of alkaline phosphatase (p < 0.0001) and osteocalcin (p < 0.005). In examination of bone metabolism in patients with skeletal metastases the following parameters are of eminent interest: osteocalcin, hydroxyproline or pyridinium crosslinks, alkaline phosphatase or ostase. These serological parameters could be helpful even with regard to early diagnosis of bone metastases. Evaluation of measuring techniques suggests quantifying pyridinium crosslinks instead of hydroxyproline, because they may be assessed without taking the patient's diet into account. Determination of bone density may be helpful in diagnostics or control of therapy modalities.

Effects of extracorporeal shock wave lithotripsy on plasma concentrations of endothelin and renin in humans

PURPOSE

There is ongoing controversy regarding blood pressure changes after extracorporeal shock wave lithotripsy (ESWL*). Experimental data suggest a role for renin but only few data are relevant to humans. It has been shown that renin secretion is stimulated by endothelin, a recently discovered peptide with strong vasoconstrictive properties and stimulating effects on renin secretion. Endothelin is relevant in the development of hypertension and acute renal failure.

MATERIALS AND METHODS

In a prospective study of 48 normotensive patients undergoing ESWL for renal stones the influence of high energy shock waves on plasma endothelin and active renin was analyzed. These substances are secreted by renal cells in response to hemodynamic alterations, and inflammatory and traumatic processes. Peripheral blood samples were analyzed for active renin and endothelin before, and immediately, 1, 3 and 5 days after ESWL. Blood pressure was measured before, and 1, 3 and 5 days after ESWL.

RESULTS

Only a slight and transient increase was noted in active renin, which was in the same range as that found after mental stress. Endothelin and blood pressure were not significantly influenced by ESWL. There was no correlation between endothelin and active renin. Thus, the increase in active renin was not mediated by endothelin.

CONCLUSIONS

The transient increase in active renin cannot be attributed to the development of hypertension. The lack of influence of ESWL on endothelin indicates that ESWL, at least in the routine clinical setting, does not cause severe renal trauma.

Osteocalcin response to calcium-restricted diet: a helpful tool for the workup of hypercalciuria

OBJECTIVES

The treatment of hypercalciuria is controversial. This study investigated whether the osteocalcin response (OCR) to a calcium-restricted diet is a potential tool for the differential therapy of hypercalciuria. 56 patients with calcium urolithiasis were investigated.

METHODS

Osteocalcin (OC) was measured on a free diet (OC 1) and after a calcium-restricted diet (400 mg/24 h for 1 week, OC 2). The OCR was expressed as 100 x (OC 2 - OC 1)/OC 1. A calcium load test and vertebral mineral density measurements (L2-L4) were performed additionally.

RESULTS

27 patients showed diet-dependent hypercalciuria, 15 of them being classified as absorptive hypercalciuria type II (AH II). 12 were normocalciuric (NC). 29 patients had diet-independent hypercalciuria, 22 being classified as renal hypercalciuria (RH), 7 as absorptive hypercalciuria type I (AH I). 22 patients (42%) showed a positive OCR, indicating an increased bone turnover. Vertebral mineral density was lower in patients with positive than with negative OCR. Generally patients with RH or NC showed a positive OCR, patients with AH a negative or no OCR. 2 patients with AH, however, showed highly positive OCR, indicating negative calcium balance. Long-term follow-up on a low calcium diet showed a steady decrease in bone mineral density.

CONCLUSIONS

This demonstrates that the OCR is more reliable to determine the appropriate management of hypercalciuria than calcium load tests. For practical purposes, we suggest treating hypercalciuric patients with positive OCR with thiazides; diet-dependent hypercalciuria with negative OCR should be treated with a low calcium diet.

Combined endoscopic closure of rectourethral fistula

PURPOSE

Rectourethral fistula formation is a rare complication of radical prostatectomy and other pelvic surgical procedures.

MATERIALS AND METHODS

In 2 patients endoscopic closure of the fistula was performed by combined transrectal endoscopic excision of the fistula, endoscopic suture, and simultaneous transurethral fulguration and fibrin application.

RESULTS

This combined approach resulted in closure of the fistula in both patients as proved by rectoscopy, retrograde urethrography and disappearance of all clinical symptoms. The latest postoperative followup was 18 months.

CONCLUSIONS

Any open procedure to correct a rectourethral fistula is considered major surgery. Therefore, the minimally invasive approach described should be attempted first in patients with a small rectourethral fistula.

[The significance of citrate, uromucoid and GAG for diagnosis of renal tubular acidosis in patients with urinary calculi]

Renal tubular acidosis (type I) is characterized by alterations that lead to disturbed acidification in the tubule. As a result of these alterations, the excretion of uromucoid (formed in the distal tubule), citrate and glycosaminoglycan (GAG) is considerably reduced. There have been numerous investigations on changes in urine pH, citrate and calcium, but few, if any studies on the excretion of uromucoid and GAG. Apart from calcium, phosphate, pH and urease, the present study investigated the excretion of uromucoid, citrate and GAG in a collective of 41 stone patients with renal tubular acidosis (type I). We found that uromucoid excretion was reduced on 90.5%, GAG in 72.2% and citrate in 96% of cases. The reduction of uromucoid excretion in particular is characteristic of RTA I, and it has the function of a marker.

[Results of color-coded duplex ultrasound diagnosis (angiodynography) after intraurethral administration of PgE1 in erectile dysfunction]

When the pathomechanism of erectile dysfunction is obscure, intraurethral administration of prostaglandin E1 is followed by a marked increase in blood flow velocity in the penile arteries as measured by color-coded Duplex sonography. This increase compares to that following intracavernous administration of half the dose of prostaglandin E1. The difference in the effects after intraurethral and intracavernous administration is the missing rigidity after intraurethral application; there must be a loss of pharmacological efficacy to the smooth penile muscles. Clinical efficacy is to be expected with higher intraurethral dosage.

Reduction of vitamin D induced stone formation by calcium

Investigations were carried out as to whether cytoprotective agents such as calcium antagonists can influence vitamin D induced nephrolithiasis. Increased vitamin D levels are found in 10-30% of all calcium oxalate stone formers. Male rats were assigned to one of the following groups: (1) 1,25-dihydroxycholecalciferol (DHCC) (n = 8), (2) 1,25-DHCC + calcium antagonist Goe 6070 (a new 1,4-dihydronaphthyridine, Goedecke, Berlin) (n = 8), or (3) control (n = 8). 1,25-DHCC was administered for 6 days (120 pmol/24 h s.c.), Goe 6070 (1 mg/kg/24 h) by gavage. Clearance studies were performed on day 6. Kidneys were taken for histological examination and determination of calcium tissue content. 1,25-DHCC induced substantial concrement formation, which could be significantly limited by Goe 6070. The calcium tissue content was also reduced (0.17 vs. 0.04 mg/100 mg dry weight). 1,25-DHCC induced a dramatic fall in the glomerular filtration rate (GFR) (3.84 ml/min per kilogram). This reduction could be almost completely inhibited by the concomitant application of Goe 6070 (9.4 ml/min per kilogram; control 10.7 ml/min per kilogram). Goe 6070 did not influence the calcium handling. The results demonstrate a protective effect of Goe 6070 on vitamin D induced nephrolithias. The histological pattern (intracellular and membrane-bound concretions) and the fact that biochemical parameters were not influenced significantly by Goe 6070 indicate that cellular proceses are important for 1,25-DHCC-induced nephrolithiasis.