[Follow-up in kidney transplantation. Which complications are likely?]. / Nach der Nierentransplantation. Mit welchen Komplikationen müssen Sie rechnen?

Kidney transplantations are being performed in every increasing numbers, and, in addition to specialist centres, nephrologists, general practitioners and urologists are more frequently being involved in the provision of aftercare. The major urological complications seen after transplantation include ureteral stenosis and necrosis, incontinence and impotence, lymphoceles, arterial stenosis, infections of the urinary tract and adnexa, as well as--the most serious complication--malignant tumours. In addition, the immunosuppression required by these patients is often associated with secondary disorders such as hypertension, steroid-related diabetes, hyperlipidemia and infections. Against the background of progressive organic deficiency it is of particular importance to identify such complications and to treat them adequately, or to prevent them from occurring, thus ensuring the longest possible survival of transplant and patient and improved quality of life.

Biokinetics and imaging with the somatostatin receptor PET radioligand (68)Ga-DOTATOC: preliminary data.

Somatostatin (SMS) scintigraphy is widely used for the detection and staging of neuroendocrine tumours. Because of its superior imaging properties, there is growing interest in the use of positron emission tomography (PET) technology for SMS scintigraphy. This study addressed the production of gallium-68 DOTATOC, its biokinetics and its clinical performance in detecting SMS-positive tumours and metastases. A preparation protocol was developed, yielding 40% overall incorporation of (68)Ga into the peptide (DOTATOC). After column filtration, the radiochemical purity exceeded 98%. Eight patients with histologically verified carcinoid tumours were injected with 80-250 MBq of this tracer. PET acquisition was initiated immediately after administration and carried out until 3 h post injection. Images were quantitated using standardised uptake values and target to non-target ratios. Prior to (68)Ga-DOTATOC PET, all patients underwent indium-111 octreotide planar and single-photon emission tomographic (SPET) imaging. Arterial activity elimination was bi-exponential, with half-lives of 2.0 (+/-0.3) min and 48 (+/-7) min. No radioactive metabolites were detected within 4 h in serum. Maximal tumour activity accumulation was reached 70+/-20 min post injection. Kidney uptake averaged <50% compared with spleen uptake. Of 40 lesions predefined by computed tomography and/or magnetic resonance imaging, (68)Ga-DOTATOC PET identified 100%, whereas (111)In-octreotide planar and SPET imaging identified only 85%. Tumour to non-tumour ratios ranged from >3:1 for liver ((111)In-octreotide: 1.5:1) to 100:1 for CNS ((111)In-octreotide: 10:1). With (68)Ga-DOTATOC >30% additional lesions were detected. It is concluded that PET using (68)Ga-DOTATOC results in high tumour to non-tumour contrast and low kidney accumulation and yields higher detection rates as compared with (111)In-octreotide scintigraphy.

Renal cell carcinoma in renal graft recipients and donors: incidence and consequence.

INTRODUCTION AND OBJECTIVES: Numerous studies have reported an increasing incidence of small renal cell carcinoma (RCC). De novo RCC in a renal allograft is a rare event and has special implications in renal transplant recipients. The objective of this study was to retrospectively evaluate the incidence of RCC in renal graft recipients and donors and to determine a procedure in cases with newly detected small renal tumors at the time of kidney preparation before transplantation. MATERIAL AND METHODS: We mailed a questionnaire to 38 German transplant clinics and received answers from 27 centers. A total of 10,997 renal graft recipients were included in the period of 1990-1998. RESULTS: In 30 kidneys (0.273%) RCC was detected at the time of preparation before transplantation. There were 23 male and 3 female donors. No bilateral RCC was described. The mean age of the donors with RCC was 50.9 years (range 37-72 years). The tumors had a mean size of 2.2 cm (range 0.4-6 cm). 67% of the patients had a renal tumor smaller than 20 mm. In 26/27 centers the decision to transplant relies on the result of the immediate section for microscopic examination. 16 patients (0.145%) developed RCC 3-12 years after renal transplantation (mean 7.4 years). The mean tumor size was 2.5 cm (range 2-2.8 cm). In 50% a grade 1 and in the other 50% a grade 2 carcinoma was found. CONCLUSIONS: Because of the RCC incidence in donor candidates we recommend an ultrasound screening of the native kidneys before renal explantation and an immediate preparation of the kidney surface especially in donors older than 45 years. In cases with small renal lesions we recommend an immediate section for microscopic examination before transplantation to prevent tumor implantation into an otherwise healthy patient. The frequency of RCCs after renal transplantation necessitates careful clinical and instrumental examinations in organ-transplanted recipients both before and at regular intervals after transplantation, including the patient's kidneys.

A MADS domain gene involved in the transition to flowering in Arabidopsis.

Flowering time in many plants is triggered by environmental factors that lead to uniform flowering in plant populations, ensuring higher reproductive success. So far, several genes have been identified that are involved in flowering time control. AGL20 (AGAMOUS LIKE 20) is a MADS domain gene from Arabidopsis that is activated in shoot apical meristems during the transition to flowering. By transposon tagging we have identified late flowering agl20 mutants, showing that AGL20 is involved in flowering time control. In previously described late flowering mutants of the long-day and constitutive pathways of floral induction the expression of AGL20 is down-regulated, demonstrating that AGL20 acts downstream to the mutated genes. Moreover, we can show that AGL20 is also regulated by the gibberellin (GA) pathway, indicating that AGL20 integrates signals of different pathways of floral induction and might be a central component for the induction of flowering. In addition, the constitutive expression of AGL20 in Arabidopsis is sufficient for photoperiod independent flowering and the over-expression of the orthologous gene from mustard, MADSA, in the classical short-day tobacco Maryland Mammoth bypasses the strict photoperiodic control of flowering.

[Clinical, infrared spectroscopic and chemical analysis of bile duct and gallbladder stones]. / Klinische, infrarotspektroskopische und chemische Analysen von Gallengangs- und Gallenblastensteinen.

By means of concrements, which were obtained endoscopically by extraction from the bile duct, and of gallstones, which were given the patient by the surgeon on the occasion of the gallbladder operation, we performed stone analyses with the aid of infrared spectroscopy and compared them correlatively with clinical and case history data. The paper focussed on the detection of the stony structure of choledochal concrements, separated into stone core and stone mantle. A method for the reliable differentiation of stones left (residual stones) from new formations (recurrent stones) in the bile ducts has not been possible to date. Thus, the burning question of the surgeon cannot be answered with certainty. However, there is no doubt about surgical suture material as incrustation core for a pigment stone in terms of a true recurrent stone, which poses a real challenge to biliary tract surgery.

Glycose aminoglycane excretion and concentration in the urine of patients with frequently recurrent calcium-oxalate lithiasis prior to and following Diclofenac-Na therapy.

Excretion and concentration of glycose aminoglycans were measured in 19 patients with frequent relapses of calcium-oxalate lithiasis, prior to and two weeks after onset of Diclofenac-Na therapy. In most patients, markedly enhanced glycose aminoglycan concentration and excretion could be demonstrated. Elevation of the high-molecular inhibitor potential in the urine results in reduced risk of calcium-oxalate lithogenesis, which may explain the therapeutic success of nonsteroidal anti-inflammatory drugs in the treatment of therapy resistant calcium-oxalate lithiasis.

[Non-medicamentous prevention of calcium oxalate urinary calculi]. / Nichtmedikamentöse Prophylaxe beim Calcium-Oxalat-Harnsteinleiden.

In a prospective study the efficacy and actual outcome of non-medicamentous preventive measures with metabolically unremarkable calcium-oxalate urolithiasis were investigated in 49 idiopathic calcium-oxalate stone formers. Overnight urine excretion was not increased. The mean concentration and excretion of essential parameters in terms of lithogenesis were hardly influenced. The obvious reduction of the pelvi-calyceal area in both lithogenous and non-lithogenous kidneys after one year of calculus prophylaxis was striking. By means of a discriminant function including morphological parameters and high-molecular urine components some developments may be verified in the discriminant space suggesting a good prophylactic result in many patients.

Influence of different factors on the formation of calcium oxalate stones. I. Discriminant analytical computations of morphological parameters of the pelvic-calyceal systems of calcium oxalate stone formers and controls.

Until now almost exclusively clinicochemical urine parameters have been used to determine the risk of urinary stone formation. In part I of this study, pelvic-calyceal systems of healthy persons and calcium oxalate stone formers are compared with regard to their morphology, whereas urine parameters will be briefly included in part II. Discriminant functions are given by means of which it is possible to calculate the risk and, e.g. to quantify a follow-up.

Influence of different factors on the formation of calcium oxalate stones. II. Discriminant analytical computations of morphological parameters of pelvic-calyceal systems and clinicochemical urine parameters of controls and calcium-oxalate stone formers.

Until now almost exclusively clinicochemical urine parameters have been used to determine the risk of urinary stone formation. In part I of this study pelvic-calyceal systems of healthy persons and calcium oxalate stone formers are compared with regard to their morphology, whereas urine parameters will be briefly included in part II. Discriminant functions are given by means of which it is possible to calculate the risk and, e.g. to quantify a follow-up.

Clinical results in the treatment of therapy-resistant calcium-stone formers with non-steroidal anti-inflammatory drugs.

Long-lasting success was obtained in the treatment of 8 therapy-resistant, frequently relapsing calcium-stone formers with non-steroidal anti-inflammatory drugs (NSAIDs). Over the period of treatment the rate of stone formation decreased markedly in these patients. Until now 3 test persons have exhibited only partial success with NSAID treatment. Diclofenac-Na as single-drug therapy or in combination with thiazide preparations or indomethacin is presented as a novel therapeutic possibility, the influence of NSAID on pathomechanism of calcium-stone formation is discussed.

[Diclofenac-Na--an alternative treatment possibility in therapy-resistant calcium oxalate urolithiasis?]. / Diclofenac-Na--eine alternative Behandlungsmöglichkeit beim therapieresistenten Kalzium-Oxalat-Harnsteinleiden?

In a prospective study, the influence of sole Diclofenac-Na therapy (3 X 25 mg Rewodina, Voltaren) on the calculus recurrence rate of eight frequently relapsing and therapy resistant calcium-oxalate stone patients is analysed. During a period of one year's treatment, the recurrence rate could be reduced by 73.2%, from 123 to 33 calculi. Serious side effects, changes in blood serological parameters and various urine components were not observed. The course of passages of calculi was improved by reduced pain and rapid passage. The paper summarizes all results of calcium-oxalate stone treatments with nonsteroidal antiphlogistics known so far. In the opinion of the authors, the present successful Diclofenac-Na treatment offers a novel possibility of influencing therapy resistant stone-formers over long periods.

[Possibilities and limits in the treatment of cystine calculus diathesis with high-dose ascorbic acid. Results of a combined study with 17 patients]. / Möglichkeiten und Grenzen bei der Behandlung der Zystinsteindiathese mit hochdosierter Ascorbinsäure. Ergebnisse einer Verbundstudie mit 17 Patienten.

17 cystine stone patients were treated with high doses of ascorbic acid (5 g p. d.). During the observation period, a total of only two natural passages of cystine stones could be observed. For five patients the therapeutic strategy was altered because the recurrence rate did not change and the cystine concentration in the urine was enhanced. One mixed calcium-oxalate/cystine stone had to be resected. In this case as well as on the occasion of further medical check-ups of other patients, an increased risk of calcium-oxalate stone formation was signalled by an enhanced oxalic-acid concentration in the 24-hour urine. Changes in blood serum and impairment in hepatic and renal functions were not observed. With three patients, the therapy had to be interrupted because of gastritis symptoms. The use of high-dose ascorbic acid therapy is recommended and is continued. In special cases, an additive of low do ses of alpha-mercaptopropionyl-glycine is recommended.

[Modification of the risk of urolithiasis by changes in magnesium and calcium concentrations in the urine as affected by stress conditions]. / Uber die Beeinflussung des Harnsteinbildungsrisikos durch Veränderungen der Magnesium- und Calciumkonzentration im Urin unter Stressbedingungen.

Under defined stress conditions, a slight decrease in the calcium concentration in the urine of calcium oxalate stone patients on the first and second experimental days was observed. Taking simultaneously recorded calcium concentrations into consideration, Ca/Mg quotients, were calculated, which, at least in single cases, exceed the limiting range, thus signalling an increased risk of calculus formation.

[Effect of proteolytic enzymes, electrolytes and other factors on the crystallization of calcium oxalate in the urine]. / Uber den Einfluss proteolytischer Fermente, Elektrolyte und anderer Faktoren auf die Kristallisation von Kalziumoxalat im Urin.

On the basis of 18 discriminance-analytically balanced urine parameters of patients with recidive calcium-oxalate nephrolithiasis and control subjects without urological complaints, it is shown in this article that the concentration of proteolytic activity, of enzyme inhibitors, of acid mucopolysaccharides and inhibition indices do not give better separation between the control group and recidive calcium-oxalate lithiasis patients than the usually measured urine parameters.

[Personal experiences in the long-term treatment of cystine lithiasis with high-dose ascorbic acid]. / Unsere Erfahrungen bei der Langzeitbehandlung des Zystinsteinleidens mit hochdosierter Askorbinsäure.

We report on our experience with 9 cystine-lithiasis patients who were treated with large doses of ascorbic acid (5 g/day) for periods ranging from 6-27 months. We observed recidive lithogenesis in only 3 patients during this time. The influence of ascorbic acid on the excretion of cystine and oxalate in the urine is discussed. A lack of side effects and the significantly lower frequency of recidivation justify the further use of ascorbic as an alternative medication in cystine lithiasis.

[Gel model for measuring crystallization inhibitor activity]. / Gelmodell zur Messung von Kristallisationsinhibitoraktivitäten.

In an attempt to develop a method with the most favourable possible relationship of information gained to expenditure of material and time a simple way of measuring crystallisation inhibitor activity was developed. Calcium and oxalate ions are diffused against each other out of two opposite start holes in a layer of gel on a microscopic slide and form a strip of calcium oxalate crystals where they meet in the middle. The substances influencing crystallisation are allowed to diffuse into this central area. The density and extent of the calcium oxalate strips vary according to the inhibitory effect of the substances used. These differences were registered by means of photometric measurement for comparison against a control without any inhibitor added and an inhibition index was computed. Some of the best-known inhibitors were tested and also show a defined effect in this model. In physiological concentrations magnesium and citrate can be said to have particular importance. The range of inhibitory activities to be expected of human urine is covered by the present model.