Lipödem heute: Zwischen konservativer Therapie, Liposuktion und Adipositaschirurgie

Die zunehmende Prävalenz des Lipödems geht einher mit einer demografischen Zunahme der Adipositas per magna.

Konservative und operative Maßnahmen ermöglichen eine ausgeprägte Befund- und Beschwerdebesserung.

Die exakte Diagnose und Differenzierung zwischen therapiebedürftiger Adipositas und therapiebedürftigem Lipödem entscheiden über Erfolg und Misserfolg der eingeleiteten Therapie.

Nach konservativem Therapieversuch kann die operative Versorgung bei Ausbleiben einer entsprechenden Besserung durch Liposuktion oder adipositaschirurgische Intervention bei einem erheblichen Teil der Betroffenen die konservative Therapie reduzieren bzw. teilweise sogar ganz überflüssig machen.

Short communication: Microlearning courses are effective at increasing the feelings of confidence and accuracy in the work of dairy personnel

Optimization of work processes and personnel compliance becomes progressively essential to ensure high process and product quality on dairy farms with an increasingly nonfamily work force. Standard operating procedures (SOP) are important to minimize variation. In addition to having a set of protocols and SOP, regular training of employees is indispensable to reduce procedural drift. A total of 243 farm owners, employees, and veterinarians from 35 farms were invited to take 3 microlearning lessons for colostrum management and provide feedback in an embedded survey. The overall response rate was 48%, and almost all participants accessed the SOP within the course (i.e., 92, 90, and 96% in the first, second, and third course, respectively). Overall, 59% (22/37) launched the course in their leisure time and 80% stated that they were convinced to work more accurately after having taken the course. Most employees underestimated the time spent in the course (76%), accessed background information (89%), or provided feedback (55%). These observations are indicative of high engagement. Overall, 78% of employees felt more confident in correct task completion after the training.

[Epidemiological data of urinary stones in cats between 1981 and 2008]

OBJECTIVE

Evaluation of urinary stones analysed between 1981 and 2008 in cats and comparison with data submitted, such as breed, age, sex and body weight.

MATERIAL AND METHODS

Over the given years 5173 feline uroliths from cats in Germany and some neighbouring countries were analysed. From the forms submitted the following data was obtained for most cats: breed, age, sex, body weight, obesity status and location of the urinary stone(s). All uroliths were analysed by infrared spectroscopy. Uroliths containing at least 70% of a single mineral were classified as being of that type.

RESULTS

The cats with urolithiasis belonged to 25 different breeds. The most common breed was the European shorthair (64.3%) followed by Persian (15.2%), British shorthair (3.9%), Chartreux (1.7%), Maine Coon (1.5%) and Siamese (1.1%). Most animals were neutered or castrated (81.8%). Tom cats were significantly more frequently affected than female cats. The mean age (7 years) was virtually identical between both sexes, but varied between different stone types. Cats with struvite stones were significantly younger than cats with calcium oxalate stones (6.6 versus 7.6 years). Most urinary stones were retrieved from the bladder and/or urethra (93%). Over the entire time period (1981-2008) struvite (51.2%) and calcium oxalate (38.7%) stones were the two most common urolith types. Percent calcium oxalate stones increased significantly over time and were seen more often in 2008 than struvite stones (48.6% versus 43.4%). Amongst other urinary stones, ammonium urate (1.7%), carbonate apatite (1.7%), cystine (0.5%) and xanthine (0.3%) uroliths were analysed.

CONCLUSION AND CLINICAL RELEVANCE

While struvite and calcium oxalate stones are presently found at approximately equal frequency in cats, various different urinary stones types can also occur in this species. Epidemiological knowledge of urinary stones is crucial as a basis for adequate therapy and prevention.

Human dendritic cells efficiently phagocytose adenoviral oncolysate but require additional stimulation to mature

Oncolytic adenoviruses are emerging agents for treatment of cancer by tumor-restricted virus infection and cell lysis. Clinical trials have shown that oncolytic adenoviruses are well tolerated in patients but also that their antitumor activity needs improvement. A promising strategy toward this end is to trigger systemic and prolonged antitumor immunity by adenoviral oncolysis. Antitumor immune activation depends in large part on antigen presentation and T cell activation by dendritic cells (DCs). Thus, it is likely that the interaction of lysed tumor cells with DCs is a key determinant of such "oncolytic vaccination." Our study reveals that human DCs effectively phagocytose melanoma cells at late stages of oncolytic adenovirus infection, when the cells die showing preferentially features of necrotic cell death. Maturation, migration toward CCL19 and T cell stimulatory capacity of DCs, crucial steps for immune induction, were, however, not induced by phagocytosis of oncolysate, but could be triggered by a cytokine maturation cocktail. Therefore, oncolytic adenoviruses and adenoviral oncolysate did not block DC maturation, which is in contrast to reports for other oncolytic viruses. These results represent a rationale for inserting immunostimulatory genes into oncolytic adenovirus genomes to assure critical DC maturation. Indeed, we report here that adenoviral transduction of melanoma cells with CD40L during oncolysis triggers the maturation of human DCs with T cell stimulatory capacity similar to DCs matured by cytokines. We conclude that triggering and shaping DC-induced antitumor immunity by oncolytic adenoviruses "armed" with immunostimulatory genes holds promise for improving the therapeutic outcome of viral oncolysis in patients.

Selectivity and efficiency of late transgene expression by transcriptionally targeted oncolytic adenoviruses are dependent on the transgene insertion strategy

Key challenges facing cancer therapy are the development of tumor-specific drugs and potent multimodal regimens. Oncolytic adenoviruses possess the potential to realize both aims by restricting virus replication to tumors and inserting therapeutic genes into the virus genome, respectively. A major effort in this regard is to express transgenes in a tumor-specific manner without affecting virus replication. Using both luciferase as a sensitive reporter and genetic prodrug activation, we show that promoter control of E1A facilitates highly selective expression of transgenes inserted into the late transcription unit. This, however, required multistep optimization of late transgene expression. Transgene insertion via internal ribosome entry site (IRES), splice acceptor (SA), or viral 2A sequences resulted in replication-dependent expression. Unexpectedly, analyses in appropriate substrates and with matching control viruses revealed that IRES and SA, but not 2A, facilitated indirect transgene targeting via tyrosinase promoter control of E1A. Transgene expression via SA was more selective (up to 1,500-fold) but less effective than via IRES. Notably, we also revealed transgene-dependent interference with splicing. Hence, the prodrug convertase FCU1 (a cytosine deaminase-uracil phosphoribosyltransferase fusion protein) was expressed only after optimizing the sequence surrounding the SA site and mutating a cryptic splice site within the transgene. The resulting tyrosinase promoter-regulated and FCU1-encoding adenovirus combined effective oncolysis with targeted prodrug activation therapy of melanoma. Thus, prodrug activation showed potent bystander killing and increased cytotoxicity of the virus up to 10-fold. We conclude that armed oncolytic viruses can be improved substantially by comparing and optimizing strategies for targeted transgene expression, thereby implementing selective and multimodal cancer therapies.

Systematic comparative protein expression profiling of clear cell renal cell carcinoma: a pilot study based on the separation of tissue specimens by two-dimensional gel electrophoresis

Proteome-based technologies represent powerful tools for the analysis of protein expression profiles, including the identification of potential cancer candidate biomarkers. Thus, here we provide a comprehensive protein expression map for clear cell renal cell carcinoma established by systematic comparative two-dimensional gel electrophoresis-based protein expression profiling of 16 paired tissue systems comprising clear cell renal cell carcinoma lesions and corresponding tumor-adjacent renal epithelium using overlapping narrow pH gradients. This approach led to the mapping of 348 distinct spots corresponding to 248 different protein identities. By implementing restriction criteria concerning their detection frequency and overall regulation mode, 28 up- and 56 down-regulated single target spots were considered as potential candidate biomarkers. Based on their gene ontology information, these differentially expressed proteins were classified into distinct functional groups and according to their cellular distribution. Moreover, three representative members of this group, namely calbindin, gelsolin, and heart fatty acid-binding protein, were selected, and their expression pattern was analyzed by immunohistochemistry using tissue microarrays. Thus, this pilot study provides a significant update of the current renal cell carcinoma map and defines a number of differentially expressed proteins, but both their potential as candidate biomarkers and clinical relevance has to be further explored in tissues and for body fluids like serum and urine.

Evaluation of urolithiasis: a link between stone formation and diabetes mellitus?

INTRODUCTION

The pathogenesis of calcium oxalate stone formation is not completely understood. Recently, an influence of vascular phenomena like arteriosclerosis on the crystallization process was hypothesized. Thus, stone formation should be more common in patients with diabetes mellitus (DM) who are at risk of developing angiopathy. The aim of the study was to determine the prevalence of urolithiasis (UL) in patients with DM and to identify specific risk factors.

MATERIAL AND METHODS

350 patients with DM were evaluated with respect to DM-related history, and a total of 179 patients was included (83 female, 96 male; age 23-84 years). All patients were interviewed to assess the history of stone formation. These data were compared to epidemiological data in Germany.

RESULTS

The overall prevalence of UL in the diabetic group was 7.82% (vs. 4.73% in Germany, p = 0.0485; binominal test). The prevalence was significantly higher in patients with coronary heart disease (25%; p < 0.0001; Fisher's exact test). We could not demonstrate an increased prevalence of UL for patients with occlusive arterial disease or arterial hypertension as diabetic nephropathy was not a risk factor for developing urinary lithiasis (p = 0.7184, p = 1.000, p = 0.6266, respectively; Fisher's exact test). Thiazide medication lowered the prevalence of stone formation (p = 0.0399; Fisher's test). Calcium or magnesium supplementation did not influence stone formation significantly (p = 0.5279; p = 1.000; respectively; Fisher's test).

CONCLUSIONS

In Germany, patients with DM are at higher risk of UL compared with patients without diabetes. We demonstrated a significantly higher prevalence of urinary stones in patients with coronary heart disease. These findings are consistent with the hypothesis that urinary stone formation has a vascular pathogenesis in part.

The spectrum of anorectal malformations in Africa

Anorectal malformations (ARM) remain a significant birth defect with geographic variation in incidence, individual phenotypes and regional geographic subtypes. Although early studies indicated a low incidence in Black patients, there is a great paucity of knowledge as to the types, frequency and incidence of ARMs encountered in the African continent and their associated anomalies. Current evidence suggests a significant clinical load. This study set out to evaluate ARM in Southern and other parts of Africa to define the clinical load of ARM. We retrospectively collected data on 1,401 ARM patients from six South African Paediatric Surgical units plus representative samples from five other African countries from West, Central and Southern Africa. Data included ethnic group, age, gender as well as the anatomical pathology, classification and presence or absence of associated anomalies. ARM lesions classified by the Wingspread classification plus an analysis of fistula position was carried out in evaluable cases for purposes of comparison. South African centres reported a higher prevalence of cloacae and vestibular fistulae, whereas rectovaginal, recto prostatic and anorectal malformation without fistula were more prevalent in the Northern African group. 76% of 1,401 patients were ethnically Black African [gender ratio = 2 (vs gender ratio 1.38 overall)] and 49.8% were "low" lesions (Wingspread classification). High or intermediate lesions were mostly males (72%). Anal stenosis was most prevalent in black males and non-Black females. Fistulae were identified in 95% with 682 (52%) being low (perineal/covered anus/vestibular) fistulae. Perineal fistulae had a male predilection (n = 260; 20%), whereas vestibular fistulas (n = 416; 32%) was strikingly frequent in black females (55%). Of the remainder, 15 fistulae were rectovesical (1.2%), 544 recto-urethral or prostatic (42%), 16 recto-vaginal (1.2%). In addition, there were 43 cloacal lesions (3.3%). Isolated rare ARM anomalies included "Pouch" colon (2) and H-type fistula (2). Isolated lesions occurred in 81% but 163 associated anomalies were identified in 114 patients. These included chromosomal lesions (10), genito-urinary anomalies (50), genital (16), cardiac (31), skeletal anomalies (33), gastro-intestinal malformations (28). Other anomalies included CNS anomalies (14), anterior abdominal wall defects (2) and facial (8) abnormalities and neuroblastoma (1). The ARM is not uncommon in Black African populations and constitutes a significant clinical load to surgical practice in Africa. Ethnic differences appear to exist and vestibular fistulae predominate in black females. Cloaca (3.3%) did appear to be more prevalent. Isolated lesions are frequent but the types of associated anomalies appear similar to other series except chromosomal syndromes. This study illustrates the need for more objective data from developing countries to assess geographical differences.

[13C2]oxalate absorption in children with idiopathic calcium oxalate urolithiasis or primary hyperoxaluria

Intestinal oxalate absorption is an important part of oxalate metabolism influencing its urinary excretion and its measurement can be a valuable diagnostic tool in hyperoxaluric disorders. In this study, we use [(13)C(2)]oxalate absorption under standardized dietary conditions to assess intestinal oxalate absorption and its impact on urinary oxalate excretion. Tests were conducted in age-matched pediatric patients that included 60 with idiopathic calcium oxalate urolithiasis, 13 with primary hyperoxaluria, and 35 healthy children. In the idiopathic stone formers, median oxalate absorption was significantly higher than that in the controls or in patients with primary disease. From standardized values obtained in control patients, oxalate hyperabsorption was detected in 23 patients with idiopathic disease but not in any patients with primary hyperoxaluria; therefore, a significant correlation between intestinal absorption and urinary excretion was found only in those with the idiopathic disease. We have shown that increased intestinal oxalate absorption is an important risk factor of idiopathic calcium oxalate urolithiasis. In contrast, low intestinal oxalate absorption in patients with primary hyperoxaluria indicates that only foods with excessive oxalate content be restricted from their diet.

Modulation of viability and maturation of human monocyte-derived dendritic cells by oncolytic adenoviruses

Adenoviral oncolysis is a promising new modality for treatment of cancer based on selective viral replication in tumor cells. However, tumor cell killing by adenoviral oncolysis needs to be improved to achieve therapeutic benefit in the clinic. Towards this end, the activation of anti-tumor immunity by adenoviral oncolysis might constitute a potent mechanism for systemic killing of uninfected tumor cells, thereby effectively complementing direct tumor cell killing by the virus. Knowledge of anti-tumor immune induction by adenoviral oncolysis, however, is lacking mostly due to species-specificity of adenovirus replication, which has hampered studies of human oncolytic adenoviruses in animals. We suggest the analysis of interactions of oncolytic adenoviruses with human immune cells as rational basis for the implementation of adenoviral oncolysis-induced anti-tumor immune activation. The goal of our study was to investigate how oncolytic adenoviruses affect human dendritic cells (DCs), key regulators of innate and adoptive immunity that are widely investigated as tumor vaccines. We report that melanoma-directed oncolytic adenoviruses, like replication-deficient adenoviruses but unlike adenoviruses with unrestricted replication potential, are not toxic to monocyte-derived immature DCs and do not block DC maturation by external stimuli. Of note, this is in contrast to reports for other viruses/viral vectors and represents a prerequisite for anti-tumor immune activation by adenoviral oncolysis. Furthermore, we show that these oncolytic adenoviruses alone do not or only partially induce DC maturation. Thus additional signals are required for optimal immune activation. These could be delivered, for example, by inserting immunoregulatory transgenes into the oncolytic adenovirus genome.

[Modern general metaphylaxis of stone disease. New risks, new evidence, new recommendations]

The prevalence and incidence of urolithiasis have markedly increased over the past several decades. Inappropriate dietary habits, overweight, and lifestyle are considered to be important risk factors for stone formation. The primary goal of metaphylaxis of stone disease is to correct the individual biochemical risk profile. A reduction in the risk of stone formation and recurrence rate can already be achieved by appropriate dietary treatment. One of the most effective dietary measures is a sufficient circadian fluid intake of suitable beverages. The reduction of overweight is suggested to additionally contribute to a decrease in the risk of recurrent stone formation.

Influence of a low- and a high-oxalate vegetarian diet on intestinal oxalate absorption and urinary excretion

OBJECTIVE

To compare quantitatively the effect of a low- and a high-oxalate vegetarian diet on intestinal oxalate absorption and urinary excretion.

SUBJECTS AND METHODS

Eight healthy volunteers (three men and five women, mean age 28.6+/-6.3) were studied. Each volunteer performed the [(13)C(2)]oxalate absorption test thrice on a low-oxalate mixed diet, thrice on a low-oxalate vegetarian diet and thrice on a high-oxalate vegetarian diet. For each test, the volunteers had to adhere to an identical diet and collect their 24-h urines. In the morning of the second day, a capsule containing [(13)C(2)]oxalate was ingested.

RESULTS

On the low-oxalate vegetarian diet, mean intestinal oxalate absorption and urinary oxalate excretion increased significantly to 15.8+/-2.9% (P=0.012) and 0.414+/-0.126 mmol/day (P=0.012), compared to the mixed diet. On the high-oxalate vegetarian diet, oxalate absorption (12.5+/-4.6%, P=0.161) and urinary excretion (0.340+/-0.077 mmol/day, P=0.093) did not change significantly, compared to the mixed diet.

CONCLUSIONS

A vegetarian diet can only be recommended for calcium oxalate stone patients, if the diet (1) contains the recommended amounts of divalent cations such as calcium and its timing of ingestion to a meal rich in oxalate is considered and (2) excludes foodstuffs with a high content of nutritional factors, such as phytic acid, which are able to chelate calcium.

NK cell activation in visceral leishmaniasis requires TLR9, myeloid DCs, and IL-12, but is independent of plasmacytoid DCs

Natural killer (NK) cells are sentinel components of the innate response to pathogens, but the cell types, pathogen recognition receptors, and cytokines required for their activation in vivo are poorly defined. Here, we investigated the role of plasmacytoid dendritic cells (pDCs), myeloid DCs (mDCs), Toll-like receptors (TLRs), and of NK cell stimulatory cytokines for the induction of an NK cell response to the protozoan parasite Leishmania infantum. In vitro, pDCs did not endocytose Leishmania promastigotes but nevertheless released interferon (IFN)-alpha/beta and interleukin (IL)-12 in a TLR9-dependent manner. mDCs rapidly internalized Leishmania and, in the presence of TLR9, produced IL-12, but not IFN-alpha/beta. Depletion of pDCs did not impair the activation of NK cells in L. infantum-infected mice. In contrast, L. infantum-induced NK cell cytotoxicity and IFN-gamma production were abolished in mDC-depleted mice. The same phenotype was observed in TLR9(-/-) mice, which lacked IL-12 expression by mDCs, and in IL-12(-/-) mice, whereas IFN-alpha/beta receptor(-/-) mice showed only a minor reduction of NK cell IFN-gamma expression. This study provides the first direct evidence that mDCs are essential for eliciting NK cell cytotoxicity and IFN-gamma release in vivo and demonstrates that TLR9, mDCs, and IL-12 are functionally linked to the activation of NK cells in visceral leishmaniasis.

Combining adenoviral oncolysis with temozolomide improves cell killing of melanoma cells

Oncolytic adenoviruses are emerging agents for treatment of cancer by tumor-restricted virus replication, cell lysis and virus spread. Clinical studies with first generation oncolytic adenoviruses have revealed that an increased potency is warranted in order to achieve therapeutic efficacy. One approach towards this end is to combine adenoviral oncolysis with chemotherapy. Here, a fundamental requirement is that chemotherapy does not interfere with adenovirus replication in cancer cells. We have previously developed a melanoma-targeted oncolytic adenovirus, Ad5/3.2xTyr, which features tyrosinase promoter regulated replication and enhanced cell entry into melanoma cells. In this study, we investigated a combination treatment of melanoma cells with Ad5/3.2xTyr and temozolomide (TMZ), which produces the same active metabolite as Dacarbazine/DTIC, the standard chemotherapy for advanced melanoma. We report that TMZ does not inhibit adenovirus replication in melanoma cells. Additive or synergistic cell killing of melanoma cells, dependent on the cell line used, was observed. Enhanced cell binding was not responsible for synergism of adenoviral oncolysis and TMZ treatment. We rather observed that higher numbers of virus genomes are produced in TMZ-treated cells, which also showed a cell cycle arrest in the G2 phase. Our results have important implications for the clinical implementation of adenoviral oncolysis for treatment of malignant melanoma. It suggests that such studies are feasible in the presence of TMZ or DTIC chemotherapy and recommends the investigation of a viro-chemo combination therapy.

Tropism modification of adenovirus vectors by peptide ligand insertion into various positions of the adenovirus serotype 41 short-fiber knob domain

Recombinant adenoviruses have emerged as promising agents in therapeutic gene transfer, genetic vaccination, and viral oncolysis. Therapeutic applications of adenoviruses, however, would benefit substantially from targeted virus cell entry, for example, into cancer or immune cells, as opposed to the broad tropism that adenoviruses naturally possess. Such tropism modification of adenoviruses requires the deletion of their natural cell binding properties and the incorporation of cell binding ligands. The short fibers of subgroup F adenoviruses have recently been suggested as a tool for genetic adenovirus detargeting based on the reduced infectivity of corresponding adenovectors with chimeric fibers in vitro and in vivo. The goal of our study was to determine functional insertion sites for peptide ligands in the adenovirus serotype 41 (Ad41) short fiber knob. With a model peptide, CDCRGDCFC, we could demonstrate that ligand incorporation into three of five analyzed loops of the knob, namely, EG, HI, and IJ, is feasible without a loss of fiber trimerization. The resulting adenovectors showed enhanced infectivity for various cell types, which was superior to that of viruses with the same peptide fused to the fiber C terminus. Strategies to further augment gene transfer efficacy by extension of the fiber shaft, insertion of tandem copies of the ligand peptide, or extension of the ligand-flanking linkers failed, indicating that precise ligand positioning is pivotal. Our study establishes that internal ligand incorporation into a short-shafted adenovirus fiber is feasible and suggests the Ad41 short fiber with ligand insertion into the top (IJ loop) or side (EG and HI loops) of the knob domain as a novel platform for genetic targeting of therapeutic adenoviruses.

Oxalobacter formigenes: a potential tool for the treatment of primary hyperoxaluria type 1

Primary hyperoxaluria is characterized by severe urolithiasis, nephrocalcinosis, and early renal failure. As treatment options are scarce, we aimed for a new therapeutic tool using colonic degradation of endogenous oxalate by Oxalobactor formigenes. Oxalobacter was orally administered for 4 weeks as frozen paste (IxOC-2) or as enteric-coated capsules (IxOC-3). Nine patients (five with normal renal function, one after liver-kidney transplantation, and three with renal failure) completed the IxOC-2 study. Seven patients (six with normal renal function and one after liver-kidney transplantation) completed the IxOC-3 study. Urinary oxalate or plasma oxalate in renal failure was determined at baseline, weekly during treatment and for a 2-week follow-up. The patients who showed >20% reduction both at the end of weeks 3 and 4 were considered as responders. Under IxOC-2, three out of five patients with normal renal function showed a 22-48% reduction of urinary oxalate. In addition, two renal failure patients experienced a significant reduction in plasma oxalate and amelioration of clinical symptoms. Under IxOC-3 treatment, four out of six patients with normal renal function responded with a reduction of urinary oxalate ranging from 38.5 to 92%. Although all subjects under IxOC-2 and 4 patients under IxOC-3 showed detectable levels of O. formigenes in stool during treatment, fecal recovery dropped directly at follow up, indicating only transient gastrointestinal-tract colonization. The preliminary data indicate that O. formigenes is safe, leads to a significant reduction of either urinary or plasma oxalate, and is a potential new treatment option for primary hyperoxaluria.

Diagnosis and metaphylaxis of stone disease. Consensus concept of the National Working Committee on Stone Disease for the upcoming German Urolithiasis Guideline

This review draws the recent state of the art in metabolic diagnosis and metaphylaxis of stone disease. It is the basis for the consensus approval with the other medical societies and institutions in Germany involved in the guideline process of the new "Urolithiasis Guideline". The German Working Committee on Stone Disease reviewed critically the current literature in the field of urolithiasis-including the existing German and EAU-Guidelines as well as the Conference Book of the First International Consultation on Stone Disease. As far as possible the references were rated according to the EBM criteria. On this basis the expert group discussed all pathways and statements regarding the management of stone disease. The present review coincides with the consented guideline draft of the German Working Committee on Stone Disease. Occurrence of stone disease in the western world increases seriously. Modern lifestyle, dietary habits and overweight-problems of the affluent societies-emerge to be the important promoters of the "stone-boom" in the new millennium. This even affects children, whose stone prevalence is otherwise significantly less than that of adults. Criteria for the high risk group of stone formers were clearly defined. A diagnostic standard is formulated for the basic and the elaborate metabolic evaluation of a stone patient. Approximately 75% of all stone patients could anticipate stone recurrence with elementary reorientation of their lifestyle and dietary habits, summarized as general metaphylaxis. About 25% of the stone formers require additional pharmacological intervention to normalize their individual biochemical risk, precisely compiled for each stone type as specific metaphylaxis.

[Calcium oxalate stones and hyperoxaluria. What is certain? What is new?]

Approximately 4 million Germans suffer from stone disease. In the majority of cases (70-75%) it is calcium oxalate. Its pathophysiology is complex and comprises disorders such as hypercalciuria, hyperoxaluria, hypocitraturia, hyperuricosuria, and hypomagnesuria. These biochemical changes in urine are well known as "classic" risk factors of calcium oxalate stone formation. However, studies in the last decade showed that calcium oxalate stones are strongly related with other diseases or disorders such as overweight, hypertension, or a lack of oxalate-degrading bacteria in the gut. The evidence for these "new" risk factors in the literature is very strong. It is particularly important in regard to effective treatment and aftercare of patients with calcium oxalate stones to be familiar with both the "classic" and the new risk factors.

Problems in the investigation of urine from patients suffering from primary hyperoxaluria type 1

Regular calculation of urinary crystallization risk indices in patients suffering from urolithiasis is a recommended measure for treatment adjustment. The more the patient experiences either extensive stone formation or an enhanced recurrence rate, the more important risk index calculations. In patients suffering from primary hyperoxaluria type 1 (PH1), both criteria are met. Different methods of risk determination are known. All strategies for measuring the calcium oxalate (CaOx) crystallization risk of a given urine principally determine this parameter from voided urine. This "bladder urine", however, has possibly passed stone material located in the urinary tract and thus may be depleted in lithogenic components. This is commonly the case for patients with PH1, who mostly experience a massive stone burden or severe nephrocalcinosis. Hence, the question arises as to whether we can adequately determine the crystallization risk in the urine of stone-bearing PH1-patients or not. Based on model calculations, we show that the determination of CaOx formation risk in PH1-patients requires knowledge of the restrictions in risk index interpretation: risk indices calculated from urinalysis (e.g. EQUIL) still indicate, even after strong in vivo stone formation, an enhanced but in fact strongly underestimated risk value. However, the outcome "enhanced" masks the patient's true risk situation. The BONN Risk Index (BRI), in contrast, discloses the process of extreme in vivo crystal formation. As determined, inter alia, from the urinary concentration of free ionized calcium ([Ca(2+)]), BRI approaches abnormally low values, as, in consequence of CaOx - formation, [Ca(2+)] tends to values close to zero. Thus, calculations of urinalysis-based risk indices alone are insufficient strategies for the quantification of a PH1 patient's CaOx crystallization risk.

Fluid intake and epidemiology of urolithiasis

A low urine volume is an important risk factor in urinary stone formation. The present article summarizes available data from epidemiological and clinical studies to elucidate the impact of fluid intake and urine volume on the risk of urinary stone formation and the prevention of stone recurrence. A review of the literature shows that an increased urine volume achieved by a high fluid intake exerts an efficacious preventive effect on the onset and recurrence of urinary stones. A high water intake and urine dilution results in a marked reduction in saturation of lithogenous salts. The type of fluids should be carefully selected to achieve the appropriate change of urine composition depending on stone composition. A sufficient intake of fluid is one of the most important preventive measures for stone recurrence.

Minute numbers of contaminant CD8+ T cells or CD11b+CD11c+ NK cells are the source of IFN-gamma in IL-12/IL-18-stimulated mouse macrophage populations

Macrophages were reported to be strong producers of interferon gamma (IFN-gamma) after stimulation by interleukin 12 (IL-12) plus IL-18, which gave rise to a novel concept of auto-crine macrophage activation. Here, we show that peritoneal exudate and bone marrow-derived mouse macrophages generated by conventional techniques contain small quantities of CD11b(+)CD11c(+)CD31(+)DX5(+)NK1.1(+) natural killer (NK) cells or CD3(+)CD8(+)TCRbeta(+) T cells, respectively. Intracellular cytokine staining, purification of macrophages by sorting, and the analysis of macrophages from alymphoid RAG2(-/-)gamma-chain(-/-) mice revealed that the high amount of IFN-gamma protein in the supernatants of unseparated IL-12/IL-18-stimulated macrophage populations originates exclusively from the contaminating lymphoid cells. Notably, IL-12/IL-18 still induced IFN-gamma mRNA in highly purified macrophages from wild-type mice and in macrophages from RAG2(-/-)gamma-chain(-/-) mice, whereas nuclear translocation of signal transducer and activator of transcription 4 (STAT4) and production of IFN-gamma protein were no longer detectable. These results question the concept of autocrine macrophage activation by secreted IFN-gamma, suggest differences in the expression of IFN-gamma mRNA and protein between macrophages and lymphoid cells, and illustrate that the limited purity of most myeloid cell populations (</= 98%) might lead to false conclusions.

The Use of Chemical Treatments for Improved Comminution of Artificial Stones

PURPOSE

The acoustic and mechanical properties of various stone compositions are significantly different and thus result in varying degrees of fragility. Consequently, results to shock wave lithotripsy (SWL) are influenced accordingly. We report the results of a study of fragility of various stone compositions, and the influence on each stone's baseline physical properties and fragility when exposed to various chemolytic solutions.

MATERIALS AND METHODS

Before SWL artificial stones of differing compositions were irrigated with various chemolytic solutions. Calcium oxalate monohydrate (COM) stones were treated with ethylenediaminetetraacetic acid (EDTA), stones composed of magnesium ammonium phosphate hydrogen were treated with hemiacidrin, and stones made of uric acid (UA) were treated with tromethamine. Synthetic urine served as a control for all stone groups. Using an ultrasound transmission technique, longitudinal wave propagation speed was measured in all groups of artificial stones. Stone density was also measured by using a pycnometer (based on Archimedes' principle). Based on these measurements transverse (shear) wave speed (assuming a constant Poisson's ratio), wave impedance and dynamic mechanical properties of the artificial stones were calculated. Moreover, the microhardness of these artificial stones was measured, and fragility testing using SWL with and without pretreatment with the previously mentioned chemolytic solutions, was performed.

RESULTS

Wave speed, wave impedance, dynamic mechanical properties and microhardness of EDTA treated COM stones and tromethamine treated UA stones were found to decrease compared to untreated (synthetic urine) control groups. The suggestion that chemolytic pretreatment increases stone fragility was verified by the finding of increased stone comminution after SWL testing. Combining this medical pretreatment and SWL, the findings demonstrate a significant impact of various solvents on stone comminution, in particular EDTA treated COM stones, tromethamine treated UA stones and hemiacidrin treated magnesium ammonium phosphate hydrogen stones. These data suggest that by altering the chemical environment of the fluid surrounding the stones it is possible to increase the fragility of renal calculi in vitro.

CONCLUSIONS

These results indicate that appropriate chemical treatments may provide a useful adjunctive modality for improving the efficacy of stone comminution during shock wave lithotripsy.

Influence of a mineral water rich in calcium, magnesium and bicarbonate on urine composition and the risk of calcium oxalate crystallization

OBJECTIVE

To evaluate the effect of a mineral water rich in magnesium (337 mg/l), calcium (232 mg/l) and bicarbonate (3388 mg/l) on urine composition and the risk of calcium oxalate crystallization.

DESIGN

A total of 12 healthy male volunteers participated in the study. During the baseline phase, subjects collected two 24-h urine samples while on their usual diet. Throughout the control and test phases, lasting 5 days each, the subjects received a standardized diet calculated according to the recommendations. During the control phase, subjects consumed 1.4 l/day of a neutral fruit tea, which was replaced by an equal volume of a mineral water during the test phase. On the follow-up phase, subjects continued to drink 1.4 l/day of the mineral water on their usual diet and collected 24-h urine samples weekly.

RESULTS

During the intake of mineral water, urinary pH, magnesium and citrate excretion increased significantly on both standardized and normal dietary conditions. The mineral water led to a significant increase in urinary calcium excretion only on the standardized diet, and to a significantly higher urinary volume and decreased supersaturation with calcium oxalate only on the usual diet.

CONCLUSIONS

The magnesium and bicarbonate content of the mineral water resulted in favorable changes in urinary pH, magnesium and citrate excretion, inhibitors of calcium oxalate stone formation, counterbalancing increased calcium excretion. Since urinary oxalate excretion did not diminish, further studies are necessary to evaluate whether the ingestion of calcium-rich mineral water with, rather than between, meals may complex oxalate in the gut thus limiting intestinal absorption and urinary excretion of calcium and oxalate.

Study on the prevalence and incidence of urolithiasis in Germany comparing the years 1979 vs. 2000

OBJECTIVES

In 1979, we conducted a representative study to determine the prevalence and incidence of urolithiasis in Germany. Significant progress in stone therapy and changes in nutritional and environmental factors since then consequently led to a second study in 2001 under the same conditions as in 1979.

METHODS

A representative sample of 7500 persons from all over Germany was questioned on the occurrence of urinary stones during their lifetimes (prevalence) and on acute urolithiasis in 2000 (incidence). Additionally, data were collected on urinary stone therapy and metaphylaxis. The current data were then compared with those from 1979.

RESULTS

Prevalence has risen from 4% to 4.7% from 1979 to 2001. 9.7% of the 50-64 year old males in 2000 had already had urinary stones (females: 5.9%). The current recurrence rate of urinary stones was estimated to be 42%. In the year 2000, the incidence of urolithiasis in Germany was found to be 1.47% (1979: 0.54%). Over 40% of the stones were passed spontaneously.

CONCLUSION

There has been a marked increase in the prevalence and incidence of urolithiasis in Germany within the last 22 years. This probably results from improvements in clinical-diagnostic procedures, changes in nutritional and environmental factors and a general apathy towards metabolic clarification and metaphylaxis.

Study on the prevalence and incidence of urolithiasis in Germany comparing the years 1979 vs. 2000

OBJECTIVES

In 1979, we conducted a representative study to determine the prevalence and incidence of urolithiasis in Germany. Significant progress in stone therapy and changes in nutritional and environmental factors since then consequently led to a second study in 2001 under the same conditions as in 1979.

METHODS

A representative sample of 7500 persons from all over Germany was questioned on the occurrence of urinary stones during their lifetimes (prevalence) and on acute urolithiasis in 2000 (incidence). Additionally, data were collected on urinary stone therapy and metaphylaxis. The current data were then compared with those from 1979.

RESULTS

Prevalence has risen from 4% to 4.7% from 1979 to 2001. 9.7% of the 50-64 year old males in 2000 had already had urinary stones (females: 5.9%). The current recurrence rate of urinary stones was estimated to be 42%. In the year 2000, the incidence of urolithiasis in Germany was found to be 1.47% (1979: 0.54%). Over 40% of the stones were passed spontaneously.

CONCLUSION

There has been a marked increase in the prevalence and incidence of urolithiasis in Germany within the last 22 years. This probably results from improvements in clinical-diagnostic procedures, changes in nutritional and environmental factors and a general apathy towards metabolic clarification and metaphylaxis.

Evaluation of urinary calculi by infrared spectroscopy

INTRODUCTION

We analyzed urinary calculi composition and its relationship with gender, age, calculus weight, color, and location.

MATERIALS AND METHODS

Two hundred and forty one patients with urinary calculus, who had undergone open lithotomy from June 1999 to April 2001, were enrolled in this prospective study which was performed by Tehran and Oroomieh Medical Sciences Universities. The calculi compositions were analyzed by infrared spectroscopy in Bonn University. Statistical analyses were made by paired t test.

RESULTS

One hundred and forty five males with a mean age of 40.4 years and 96 females with a mean age of 42.5 years were enrolled in this study. Mean calculus weight was 4.28 gr. Mean calculus number was 4.33. Thirty four (14.1%) calculi were pure (carbonate apatite: 2, brushite: 1, uric acid: 19, cystine: 3, weddellite: 6, mono-NH4-urate: 2, struvite: 1), 207(85.6%) were mixed and none of them contained octa-ca-phosphate, apatite, newberyte, 2,8-dihydroxyadenine, mono-Na-urate, or xanthine. Weddellite was found in 77% of calculi. It comprised more than 50% of them in 26% of cases. Whewellite crystals were found in 78% of calculi. It comprised more than 50% of them in 46% of cases. The most common pure calculus was uric acid and the most common component of calculi was whewellite followed by weddellite.

CONCLUSION

Although there is no comprehensive study on urolithiasis incidence and prevalence in Iran, it can be concluded that whewellite and weddellite may be the most common components of urolithiasis in Iran and uric acid calculi are the most common pure calculi. There was no significant difference in calculi composition in our study.

Fehlinterpretation von Urinanalysen durch in vivo wachsende Harnsteine

The occurrence of biochemically unaltered urinalyses in patients with severe recurrent stone formation is not a rare observation in practice. The possible reasons for that phenomenon are manifold. We show that stone growth-related urinary depletion of lithogenic constituents caused by acute growth of urinary calculi in vivo can be an important reason for the observed phenomenon. The described process which can strongly influence the urinary composition occurs in any stone-bearing patient. Thus, it is strongly recommended that stone-related alterations be taken into account when interpreting the urinalyses of these patients. Based on simplified model assumptions, the extent of the expected chemical depletion effect can be calculated for any stone patient's urine sample. In two easy-to-use nomograms, we have combined the key parameters which govern the process, allowing the user a fast and easy estimation.

[A new method for the evaluation of stone fragmentation after ESWL]

INTRODUCTION

Efficacy of ESWL treatment can be evaluated by determining the number and size of urinary stone fragments. However, the available methods for classification of stone fragments are inaccurate. Therefore, a method for semi-automatic determination of fragment size and number after ESWL was developed.

METHODS

Artificial struvite stones (BON[N]-STONES) were disintegrated with a lithotriptor (Siemens, Lithostar plus) by application of 50 and 200 shock waves at 19 kV. The stone fragments were collected and pre-sorted on cascade sieves. Pictures taken of the fractions were digitalized and the images optimized in edge sharpness, contrast, and colour depth using an image processing software. Finally, the pixel number of each fragment was determined and the real area was calculated. Fragment size and volume were then depicted by frequency of occurrence in a histogram.

RESULTS

Fragments with a diameter ranging from 0.3 - 5 mm could be determined by the system described. About 2,000 - 3,600 fragments were generated in this size range from the artificial struvite stones. With low shock-wave application, a considerable number of fragments larger than 2 mm could be observed. By increasing the impact to 200, more than 90 % of the stone volume was found in fragments smaller than 2 mm (previously 50 %).

CONCLUSION

The system described enables a qualitative and quantitative description of stone fragmentation after ESWL not achieved thus far.

Genetic variations of the SLC7A9 gene: allele distribution of 13 polymorphic sites in German cystinuria patients and controls

Cystinuria is a hereditary disorder of cystine and dibasic amino acid transport across the luminal membrane of renal tubules and intestine, resulting in recurrent nephrolithiasis. While mutations in the SLC3A1 gene cause type I cystinuria, patients with non-type I cystinuria carry mutations in the SLC7A9 gene. Both gene products form the renal amino acid transporter rBAT/b0,+AT affected in cystinuria. In the present study a total of 59 patients with different ethnic background were screened for sequence variations in SLC7A9, out of these 32 were of German origin. For determination of allele frequencies of detected polymorphisms, 58 healthy German controls were investigated. Molecular-genetic analysis was performed using single-strand conformation polymorphism analysis, restriction assays and sequencing. Allele frequencies were analyzed statistically for the detected polymorphisms. In addition to the 6 already known variants we identified 7 new polymorphisms. Statistical analyses showed a significantly different distribution of alleles between German patients and German controls in case of the polymorphisms c. 147C>T (exon 2), c.386C>T (exon 3), IVS3+22T>G, c.584C>T (exon 4), c.610T>C (exon 4), c.692C>T (exon 5), c.852C>A (exon 6) and c.872C>T (exon 6). In summary, our results show that cystinuria is a complex disease which is not only caused by mutations in SLC7A9 and SLC3A1, but also influenced by other modifying factors such as variants in SLC7A9.

[Monitoring of the treatment of calcium-oxalate stone formers with the Bonn-Risk-Index]

Cost-effective metaphylaxis and monitoring is becoming more and more focused in the treatment of urinary stones. Therefore, medical practitioners are asked to reduce the analytical efforts necessary for evaluation and to control the actual biochemical risk of stone formation in the patients. The most common strategy available is based on chemical urinalysis and the calculation of theoretically derived risk parameters. However, this covers--in the best case--the analysis of the most prominent low molecular urinary constituents. No information about the fraction of the important macromolecular urinary components is obtained. Crystallization experiments in unprepared, native urine samples, carried out according to the Bonn-Risk-Index approach (BRI), allow the determination of a more realistic measure of a urine's crystallization risk since the entire urinary composition influences the experimental result. As only two parameters have to be analyzed, the BRI is a fast and cost-effective risk evaluation method. The results show a high selectivity between stone-formers and non-stone-forming persons. The changes in the BRI-risk of three calcium oxalate stone-formers after a 1 week stay in our hospital are presented and discussed in detail. In one of these patients, a follow up examination was performed in order to control the therapy's success and, additionally, to obtain information about the patient's compliance with the therapy. During hospitalization, the patients received a standardized and "stone-neutral" diet. All persons showed a distinct decrease in their individual crystallization risk.