Salt-inducible kinase inhibition promotes the adipocyte thermogenic program and adipose tissue browning

OBJECTIVE

Norepinephrine stimulates the adipose tissue thermogenic program through a β-adrenergic receptor (βAR)-cyclic adenosine monophosphate (cAMP)-protein kinase A (PKA) signaling cascade. We discovered that a noncanonical activation of the mechanistic target of rapamycin complex 1 (mTORC1) by PKA is required for the βAR-stimulation of adipose tissue browning. However, the downstream events triggered by PKA-phosphorylated mTORC1 activation that drive this thermogenic response are not well understood.

METHODS

We used a proteomic approach of Stable Isotope Labeling by/with Amino acids in Cell culture (SILAC) to characterize the global protein phosphorylation profile in brown adipocytes treated with the βAR agonist. We identified salt-inducible kinase 3 (SIK3) as a candidate mTORC1 substrate and further tested the effect of SIK3 deficiency or SIK inhibition on the thermogenic gene expression program in brown adipocytes and in mouse adipose tissue.

RESULTS

SIK3 interacts with RAPTOR, the defining component of the mTORC1 complex, and is phosphorylated at Ser884 in a rapamycin-sensitive manner. Pharmacological SIK inhibition by a pan-SIK inhibitor (HG-9-91-01) in brown adipocytes increases basal Ucp1 gene expression and restores its expression upon blockade of either mTORC1 or PKA. Short-hairpin RNA (shRNA) knockdown of Sik3 augments, while overexpression of SIK3 suppresses, Ucp1 gene expression in brown adipocytes. The regulatory PKA phosphorylation domain of SIK3 is essential for its inhibition. CRISPR-mediated Sik3 deletion in brown adipocytes increases type IIa histone deacetylase (HDAC) activity and enhances the expression of genes involved in thermogenesis such as Ucp1, Pgc1α, and mitochondrial OXPHOS complex protein. We further show that HDAC4 interacts with PGC1α after βAR stimulation and reduces lysine acetylation in PGC1α. Finally, a SIK inhibitor well-tolerated in vivo (YKL-05-099) can stimulate the expression of thermogenesis-related genes and browning of mouse subcutaneous adipose tissue.

CONCLUSIONS

Taken together, our data reveal that SIK3, with the possible contribution of other SIKs, functions as a phosphorylation switch for β-adrenergic activation to drive the adipose tissue thermogenic program and indicates that more work to understand the role of the SIKs is warranted. Our findings also suggest that maneuvers targeting SIKs could be beneficial for obesity and related cardiometabolic disease.

Acetylation and phosphorylation changes to cardiac proteins in experimental HFpEF due to metabolic risk reveal targets for treatment

AIMS

Despite the high prevalence of heart failure with preserved ejection fraction (HFpEF), the pathomechanisms remain elusive and specific therapy is lacking. Disease-causing factors include metabolic risk, notably obesity. However, proteomic changes in HFpEF are poorly understood, hampering therapeutic strategies. We sought to elucidate how metabolic syndrome affects cardiac protein expression, phosphorylation and acetylation in the Zucker diabetic fatty/Spontaneously hypertensive heart failure F1 (ZSF1) rat HFpEF model, and to evaluate changes regarding their potential for treatment.

MAIN METHODS

ZSF1 obese and lean rats were fed a Purina diet up to the onset of HFpEF in the obese animals. We quantified the proteome, phosphoproteome and acetylome of ZSF1 obese versus lean heart tissues by mass spectrometry and singled out targets for site-specific evaluation.

KEY FINDINGS

The acetylome of ZSF1 obese versus lean hearts was more severely altered (21 % of proteins changed) than the phosphoproteome (9 %) or proteome (3 %). Proteomic alterations, confirmed by immunoblotting, indicated low-grade systemic inflammation and endothelial remodeling in obese hearts, but low nitric oxide-dependent oxidative/nitrosative stress. Altered acetylation in ZSF1 obese hearts mainly affected pathways important for metabolism, energy production and mechanical function, including hypo-acetylation of mechanical proteins but hyper-acetylation of proteins regulating fatty acid metabolism. Hypo-acetylation and hypo-phosphorylation of elastic titin in ZSF1 obese hearts could explain myocardial stiffening.

SIGNIFICANCE

Cardiometabolic syndrome alters posttranslational modifications, notably acetylation, in experimental HFpEF. Pathway changes implicate a HFpEF signature of low-grade inflammation, endothelial dysfunction, metabolic and mechanical impairment, and suggest titin stiffness and mitochondrial metabolism as promising therapeutic targets.

Treatment outcomes of bladder stones in children with intact bladders in developing countries: A systematic review of >1000 cases on behalf of the European Association of Urology Bladder Stones Guideline panel

INTRODUCTION

Bladder stones (BS) are still endemic in children in developing nations and account for a high volume of paediatric urology workload in these areas. The aim of this systematic review is to comparatively assess the benefits and risks of minimally invasive and open surgical interventions for the treatment of bladder stones in children.

METHODS

This systematic review was conducted in accordance with Cochrane Guidance. Database searches (January 1970- March 2021) were screened, abstracted, and assessed for risk of bias for comparative randomised controlled trials (RCTs) and non-randomised studies (NRSs) with >10 patients per group. Open cystolithotomy (CL), transurethral cystolithotripsy (TUCL), percutaneous cystolithotripsy (PCCL), extracorporeal shock wave lithotripsy (ESWL) and laparoscopic cystolithotomy (LapCL) were evaluated.

RESULTS

In total, 3040 abstracts were screened, and 8 studies were included. There were 7 retrospective non-randomised studies (NRS's) and 1 quasi-RCT with 1034 eligible patients (CL: n=637, TUCL: n=196, PCCL: n=138, ESWL: n=63, LapCL n=0). Stone free rate (SFR) was given in 7 studies and measured 100%, 86.6%-100%, and 100% for CL, TUCL and PCCL respectively. CL was associated with a longer duration of inpatient stay than PCCL and TUCL (p<0.05). One NRS showed that SFR was significantly lower after 1 session with outpatient ESWL (47.6%) compared to TUCL (93.5%) and CL (100%) (p<0.01 and p<0.01 respectively). One RCT compared TUCL with laser versus TUCL with pneumatic lithotripsy and found that procedure duration was shorter with laser for stones <1.5cm (n=25, p=0.04).

CONCLUSION

In conclusion, CL, TUCL and PCCL have comparable SFRs but ESWL is less effective for treating stones in paediatric patients. CL has the longest duration of inpatient stay. Information gathered from this systematic review will enable paediatric urologists to comparatively assess the risks and benefits of all urological modalities when considering surgical intervention for bladder stones.

Low kindlin-3 levels in osteoclasts of kindlin-3 hypomorphic mice result in osteopetrosis due to leaky sealing zones

Osteoclasts form special integrin-mediated adhesion structures called sealing zones that enable them to adhere to and resorb bone. Sealing zones consist of densely packed podosomes tightly interconnected by actin fibers. Their formation requires the presence of the hematopoietic integrin regulator kindlin-3 (also known as Fermt3). In this study, we investigated osteoclasts and their adhesion structures in kindlin-3 hypomorphic mice expressing only 5-10% of the kindlin-3 level of wild-type mice. Low kindlin-3 expression reduces integrin activity, results in impaired osteoclast adhesion and signaling, and delays cell spreading. Despite these defects, in vitro-generated kindlin-3-hypomorphic osteoclast-like cells arrange their podosomes into adhesion patches and belts, but their podosome and actin organization is abnormal. Remarkably, kindlin-3-hypomorphic osteoclasts form sealing zones when cultured on calcified matrix in vitro and on bone surface in vivo. However, functional assays, immunohistochemical staining and electron micrographs of bone sections showed that they fail to seal the resorption lacunae properly, which is required for secreted proteinases to digest bone matrix. This results in mild osteopetrosis. Our study reveals a new, hitherto understudied function of kindlin-3 as an essential organizer of integrin-mediated adhesion structures, such as sealing zones.

Raptor is critical for increasing the mitochondrial proteome and skeletal muscle force during hypertrophy

Loss of skeletal muscle mass and force is of critical importance in numerous pathologies, like age-related sarcopenia or cancer. It has been shown that the Akt-mTORC1 pathway is critical for stimulating adult muscle mass and function, however, it is unknown if mTORC1 is the only mediator downstream of Akt and which intracellular processes are required for functional muscle growth. Here, we show that loss of Raptor reduces muscle hypertrophy after Akt activation and completely prevents increases in muscle force. Interestingly, the residual hypertrophy after Raptor deletion can be completely prevented by administration of the mTORC1 inhibitor rapamycin. Using a quantitative proteomics approach we find that loss of Raptor affects the increases in mitochondrial proteins, while rapamycin mainly affects ribosomal proteins. Taken together, these results suggest that mTORC1 is the key mediator of Akt-dependent muscle growth and its regulation of the mitochondrial proteome is critical for increasing muscle force.

PERM1 interacts with the MICOS-MIB complex to connect the mitochondria and sarcolemma via ankyrin B

Skeletal muscle subsarcolemmal mitochondria (SSM) and intermyofibrillar mitochondria subpopulations have distinct metabolic activity and sensitivity, though the mechanisms that localize SSM to peripheral areas of muscle fibers are poorly understood. A protein interaction study and complexome profiling identifies PERM1 interacts with the MICOS-MIB complex. Ablation of Perm1 in mice reduces muscle force, decreases mitochondrial membrane potential and complex I activity, and reduces the numbers of SSM in skeletal muscle. We demonstrate PERM1 interacts with the intracellular adaptor protein ankyrin B (ANKB) that connects the cytoskeleton to the plasma membrane. Moreover, we identify a C-terminal transmembrane helix that anchors PERM1 into the outer mitochondrial membrane. We conclude PERM1 functions in the MICOS-MIB complex and acts as an adapter to connect the mitochondria with the sarcolemma via ANKB.

Nicotinamide for the treatment of heart failure with preserved ejection fraction

Heart failure with preserved ejection fraction (HFpEF) is a highly prevalent and intractable form of cardiac decompensation commonly associated with diastolic dysfunction. Here, we show that diastolic dysfunction in patients with HFpEF is associated with a cardiac deficit in nicotinamide adenine dinucleotide (NAD⁺). Elevating NAD⁺ by oral supplementation of its precursor, nicotinamide, improved diastolic dysfunction induced by aging (in 2-year-old C57BL/6J mice), hypertension (in Dahl salt-sensitive rats), or cardiometabolic syndrome (in ZSF1 obese rats). This effect was mediated partly through alleviated systemic comorbidities and enhanced myocardial bioenergetics. Simultaneously, nicotinamide directly improved cardiomyocyte passive stiffness and calcium-dependent active relaxation through increased deacetylation of titin and the sarcoplasmic reticulum calcium adenosine triphosphatase 2a, respectively. In a long-term human cohort study, high dietary intake of naturally occurring NAD⁺ precursors was associated with lower blood pressure and reduced risk of cardiac mortality. Collectively, these results suggest NAD⁺ precursors, and especially nicotinamide, as potential therapeutic agents to treat diastolic dysfunction and HFpEF in humans.

An mTORC1-GRASP55 signaling axis controls unconventional secretion to reshape the extracellular proteome upon stress

Cells communicate with their environment via surface proteins and secreted factors. Unconventional protein secretion (UPS) is an evolutionarily conserved process, via which distinct cargo proteins are secreted upon stress. Most UPS types depend upon the Golgi-associated GRASP55 protein. However, its regulation and biological role remain poorly understood. Here, we show that the mechanistic target of rapamycin complex 1 (mTORC1) directly phosphorylates GRASP55 to maintain its Golgi localization, thus revealing a physiological role for mTORC1 at this organelle. Stimuli that inhibit mTORC1 cause GRASP55 dephosphorylation and relocalization to UPS compartments. Through multiple, unbiased, proteomic analyses, we identify numerous cargoes that follow this unconventional secretory route to reshape the cellular secretome and surfactome. Using MMP2 secretion as a proxy for UPS, we provide important insights on its regulation and physiological role. Collectively, our findings reveal the mTORC1-GRASP55 signaling hub as the integration point in stress signaling upstream of UPS and as a key coordinator of the cellular adaptation to stress.

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mTORC1 phosphorylates GRASP55 directly at the Golgi in non-stressed cells

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mTORC1 inactivation by stress leads to GRASP55 dephosphorylation and relocalization

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GRASP55 relocalization to autophagosomes and MVBs drives UPS of selected cargo

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mTORC1-GRASP55 link cellular stress to changes in the extracellular proteome via UPS

Phosphoproteomics of the developing heart identifies PERM1 - An outer mitochondrial membrane protein

Heart development relies on PTMs that control cardiomyocyte proliferation, differentiation and cardiac morphogenesis. We generated a map of phosphorylation sites during the early stages of cardiac postnatal development in mice; we quantified over 10,000 phosphorylation sites and 5000 proteins that were assigned to different pathways. Analysis of mitochondrial proteins led to the identification of PGC-1- and ERR-induced regulator in muscle 1 (PERM1), which is specifically expressed in skeletal muscle and heart tissue and associates with the outer mitochondrial membrane. We demonstrate PERM1 is subject to rapid changes mediated by the UPS through phosphorylation of its PEST motif by casein kinase 2. Ablation of Perm1 in mice results in reduced protein expression of lipin-1 accompanied by accumulation of specific phospholipid species. Isolation of Perm1-deficient mitochondria revealed significant downregulation of mitochondrial transport proteins for amino acids and carnitines, including SLC25A12/13/29/34 and CPT2. Consistently, we observed altered levels of various lipid species, amino acids, and acylcarnitines in Perm1^-/- mitochondria. We conclude that the outer mitochondrial membrane protein PERM1 regulates homeostasis of lipid and amino acid metabolites in mitochondria.

Exercise-dependent increases in protein synthesis are accompanied by chromatin modifications and increased MRTF-SRF signalling

AIM

Resistance exercise increases muscle mass over time. However, the early signalling events leading to muscle growth are not yet well-defined. Here, we aim to identify new signalling pathways important for muscle remodelling after exercise.

METHODS

We performed a phosphoproteomics screen after a single bout of exercise in mice. As an exercise model we used unilateral electrical stimulation in vivo and treadmill running. We analysed muscle biopsies from human subjects to verify if our findings in murine muscle also translate to exercise in humans.

RESULTS

We identified a new phosphorylation site on Myocardin-Related Transcription Factor B (MRTF-B), a co-activator of serum response factor (SRF). Phosphorylation of MRTF-B is required for its nuclear translocation after exercise and is accompanied by the transcription of the SRF target gene Fos. In addition, high-intensity exercise also remodels chromatin at specific SRF target gene loci through the phosphorylation of histone 3 on serine 10 in myonuclei of both mice and humans. Ablation of the MAP kinase member MSK1/2 is sufficient to prevent this histone phosphorylation, reduce induction of SRF-target genes, and prevent increases in protein synthesis after exercise.

CONCLUSION

Our results identify a new exercise signalling fingerprint in vivo, instrumental for exercise-induced protein synthesis and potentially muscle growth.

High-throughput proteomics fiber typing (ProFiT) for comprehensive characterization of single skeletal muscle fibers

BACKGROUND

Skeletal muscles are composed of a heterogeneous collection of fiber types with different physiological adaption in response to a stimulus and disease-related conditions. Each fiber has a specific molecular expression of myosin heavy chain molecules (MyHC). So far, MyHCs are currently the best marker proteins for characterization of individual fiber types, and several proteome profiling studies have helped to dissect the molecular signature of whole muscles and individual fibers.

METHODS

Herein, we describe a mass spectrometric workflow to measure skeletal muscle fiber type-specific proteomes. To bypass the limited quantities of protein in single fibers, we developed a Proteomics high-throughput fiber typing (ProFiT) approach enabling profiling of MyHC in single fibers. Aliquots of protein extracts from separated muscle fibers were subjected to capillary LC-MS gradients to profile MyHC isoforms in a 96-well format. Muscle fibers with the same MyHC protein expression were pooled and subjected to proteomic, pulsed-SILAC, and phosphoproteomic analysis.

RESULTS

Our fiber type-specific quantitative proteome analysis confirmed the distribution of fiber types in the soleus muscle, substantiates metabolic adaptions in oxidative and glycolytic fibers, and highlighted significant differences between the proteomes of type IIb fibers from different muscle groups, including a differential expression of desmin and actinin-3. A detailed map of the Lys-6 incorporation rates in muscle fibers showed an increased turnover of slow fibers compared to fast fibers. In addition, labeling of mitochondrial respiratory chain complexes revealed a broad range of Lys-6 incorporation rates, depending on the localization of the subunits within distinct complexes.

CONCLUSION

Overall, the ProFiT approach provides a versatile tool to rapidly characterize muscle fibers and obtain fiber-specific proteomes for different muscle groups.

Skeletal muscle mTORC1 regulates neuromuscular junction stability

BACKGROUND

Skeletal muscle is a plastic tissue that can adapt to different stimuli. It is well established that Mammalian Target of Rapamycin Complex 1 (mTORC1) signalling is a key modulator in mediating increases in skeletal muscle mass and function. However, the role of mTORC1 signalling in adult skeletal muscle homeostasis is still not well defined.

METHODS

Inducible, muscle-specific Raptor and mTOR k.o. mice were generated. Muscles at 1 and 7 months after deletion were analysed to assess muscle histology and muscle force.

RESULTS

We found no change in muscle size or contractile properties 1 month after deletion. Prolonging deletion of Raptor to 7 months, however, leads to a very marked phenotype characterized by weakness, muscle regeneration, mitochondrial dysfunction, and autophagy impairment. Unexpectedly, reduced mTOR signalling in muscle fibres is accompanied by the appearance of markers of fibre denervation, like the increased expression of the neural cell adhesion molecule (NCAM). Both muscle-specific deletion of mTOR or Raptor, or the use of rapamycin, was sufficient to induce 3-8% of NCAM-positive fibres (P < 0.01), muscle fibrillation, and neuromuscular junction (NMJ) fragmentation in 24% of examined fibres (P < 0.001). Mechanistically, reactivation of autophagy with the small peptide Tat-beclin1 is sufficient to prevent mitochondrial dysfunction and the appearance of NCAM-positive fibres in Raptor k.o. muscles.

CONCLUSIONS

Our study shows that mTOR signalling in skeletal muscle fibres is critical for maintaining proper fibre innervation, preserving the NMJ structure in both the muscle fibre and the motor neuron. In addition, considering the beneficial effects of exercise in most pathologies affecting the NMJ, our findings suggest that part of these beneficial effects of exercise are through the well-established activation of mTORC1 in skeletal muscle during and after exercise.

Muscle regulates mTOR dependent axonal local translation in motor neurons via CTRP3 secretion: implications for a neuromuscular disorder, spinal muscular atrophy

Spinal muscular atrophy (SMA) is an inherited neuromuscular disorder, which causes dysfunction/loss of lower motor neurons and muscle weakness as well as atrophy. While SMA is primarily considered as a motor neuron disease, recent data suggests that survival motor neuron (SMN) deficiency in muscle causes intrinsic defects. We systematically profiled secreted proteins from control and SMN deficient muscle cells with two combined metabolic labeling methods and mass spectrometry. From the screening, we found lower levels of C1q/TNF-related protein 3 (CTRP3) in the SMA muscle secretome and confirmed that CTRP3 levels are indeed reduced in muscle tissues and serum of an SMA mouse model. We identified that CTRP3 regulates neuronal protein synthesis including SMN via mTOR pathway. Furthermore, CTRP3 enhances axonal outgrowth and protein synthesis rate, which are well-known impaired processes in SMA motor neurons. Our data revealed a new molecular mechanism by which muscles regulate the physiology of motor neurons via secreted molecules. Dysregulation of this mechanism contributes to the pathophysiology of SMA.

A kindlin-3-leupaxin-paxillin signaling pathway regulates podosome stability

Kindlin-3 regulates podosome stability by recruiting leupaxin to podosomes, which in turn controls PTP-PEST activity and paxillin phosphorylation. Kindlin-3 deficiency allows formation of initial adhesion patches containing talin, vinculin, and paxillin, whereas paxillin family proteins are dispensable for podosome formation.

Binding of kindlins to integrins is required for integrin activation, stable ligand binding, and subsequent intracellular signaling. How hematopoietic kindlin-3 contributes to the assembly and stability of the adhesion complex is not known. Here we report that kindlin-3 recruits leupaxin into podosomes and thereby regulates paxillin phosphorylation and podosome turnover. We demonstrate that the activity of the protein tyrosine phosphatase PTP-PEST, which controls paxillin phosphorylation, requires leupaxin. In contrast, despite sharing the same binding mode with leupaxin, paxillin recruitment into podosomes is kindlin-3 independent. Instead, we found paxillin together with talin and vinculin in initial adhesion patches of kindlin-3–null cells. Surprisingly, despite its presence in these early adhesion patches, podosomes can form in the absence of paxillin or any paxillin member. In conclusion, our findings show that kindlin-3 not only activates and clusters integrins into podosomes but also regulates their lifetime by recruiting leupaxin, which controls PTP-PEST activity and thereby paxillin phosphorylation and downstream signaling.

Aktualisierung der S2k-Leitlinie zur Diagnostik, Therapie und Metaphylaxe der Urolithiasis (AWMF Registernummer 043-025)

Die Zunahme des medizinischen Wissens, technische Neuerungen gemeinsam mit demographischem Wandel stellen eine Herausforderung an die Neukonzeption von Leitlinien und klinischen Studien dar. Die vorliegende S2k-Leitlinie, die sich ausschließlich mit Nieren- und Harnleitersteinen beschäftigt, soll die Behandlung von Harnsteinpatienten in Klinik und Praxis unterstützen, aber auch Patienteninformationen zur Urolithiasis geben. Die zunehmende interdisziplinäre Zusammenarbeit in der Steintherapie zeigt sich auch an der Anzahl beteiligter Fachgruppen und Arbeitsgemeinschaften in der Erstellung des neuen Leitlinienupdates. Die vorliegende, aus einem interdisziplinären Konsensusprozess hervorgegangene S2k-Leitlinie stellt die aktuellen Empfehlungen praxisnah dar und gibt Entscheidungshilfen für Diagnostik‑, Therapie- und Metaphylaxemaßnahmen auf Basis von Expertenmeinungen und verfügbaren Evidenzgrundlagen aus der Literatur.

Dynamic changes in the mouse skeletal muscle proteome during denervation-induced atrophy

Loss of neuronal stimulation enhances protein breakdown and reduces protein synthesis, causing rapid loss of muscle mass. To elucidate the pathophysiological adaptations that occur in atrophying muscles, we used stable isotope labelling and mass spectrometry to quantify protein expression changes accurately during denervation-induced atrophy after sciatic nerve section in the mouse gastrocnemius muscle. Additionally, mice were fed a stable isotope labelling of amino acids in cell culture (SILAC) diet containing ¹³C₆-lysine for 4, 7 or 11 days to calculate relative levels of protein synthesis in denervated and control muscles. Ubiquitin remnant peptides (K-ε-GG) were profiled by immunoaffinity enrichment to identify potential substrates of the ubiquitin-proteasomal pathway. Of the 4279 skeletal muscle proteins quantified, 850 were differentially expressed significantly within 2 weeks after denervation compared with control muscles. Moreover, pulse labelling identified Lys6 incorporation in 4786 proteins, of which 43 had differential Lys6 incorporation between control and denervated muscle. Enrichment of diglycine remnants identified 2100 endogenous ubiquitination sites and revealed a metabolic and myofibrillar protein diglycine signature, including myosin heavy chains, myomesins and titin, during denervation. Comparative analysis of these proteomic data sets with known atrogenes using a random forest approach identified 92 proteins subject to atrogene-like regulation that have not previously been associated directly with denervation-induced atrophy. Comparison of protein synthesis and proteomic data indicated that upregulation of specific proteins in response to denervation is mainly achieved by protein stabilization. This study provides the first integrated analysis of protein expression, synthesis and ubiquitin signatures during muscular atrophy in a living animal.

Summary: Comprehensive proteomic profiling of protein expression, synthesis and ubiquitination during skeletal muscle atrophy reveals that complex regulatory networks are activated during muscle wasting.

[Urolithiasis guidelines: retrospective view and perspectives]

The first German guidelines on urolithiasis were published in four sections in "Der Urologe A" in 1997 and were listed at The Association of the Scientific Medical Societies in Germany (AWMF) in 1999. The European Association of Urology (EAU) published the first guidelines on urolithiasis in 2000. All guidelines must be updated on a regular basis. Guidelines should represent the highest level of evidence for the best diagnostic and therapeutic procedures, independent of economic pressure. Guidelines should safeguard optimal patient care and also serve as a basis for education and training of healthcare professionals. They are a tool for quality management and for national healthcare structures and strategies as well as for the judicature. Medical guidelines form the foundation for the elaboration of local clinical treatment pathways, which are the bridge to treatment of patients and also take economic and regional circumstances into consideration. In the future information technology (IT) could play an even more important role for both the complex methods of establishing guidelines and their implementation. The contents of guidelines could then be directly integrated into the clinical pathway, if necessary or into electronic patient charts in order to propose a medically and financially optimized treatment pathway. Because of the complexity of producing guidelines, they will in part be produced at a national level and adapted to the regional circumstances. Future technical, medical and genetic developments will lead to a multidisciplinary and multiprofessional cooperation in the production of guidelines.

Management of ureteric stones

Based on experience with over 2,000 patients, the treatment of ureteric stones today relies on extracorporeal shock wave lithotripsy (ESWL) in situ and ureteroscopy with semirigid, ultrathin ureteroscopes combined with pneumatic or laser lithotripsy. All stones in the upper and larger stones in the distal third of the ureter are preferably treated by ESWL in situ, whereas smaller stones in the distal ureter are better treated by endoscopy. Midureteric stones continue to be the domain of primary ureteroscopy; in cases of moderate obstruction in asymptomatic patients, it may also be acceptable to wait for the stone to pass into the distal ureter spontaneously to be treated by ESWL in situ there. Manipulation of the stone back into the kidney and treating it by ESWL there (push back/ESWL) offers no advantage over ESWL in situ, as results are not better yet morbidity is higher. 'Blind' instrumentation has lost all justification, and incisional ureteric lithotomy is no longer indicated but in exceptional cases.

Management of ureteric calculi (minimally invasive therapy of ureteric stones)

As documented with results obtained in 1685 patients the treatment of ureteric stones is today based on ESWL in situ and ureteroscopy with semirigid, ultrathin ureteroscopes and laser lithotripsy. All stones in the upper third of the ureter and larger stones in the distal third of the ureter are preferably treated with ESWL in situ whereas smaller stones in the distal ureter are better treated endoscopically. Midureteric stones remain the domain of primary ureteroscopy; with moderate obstruction in the asymptomatic patient it may also be acceptable to wait for the stone to pass into the distal ureter spontaneously to be treated by ESWL in situ there. Manipulating stones back into the kidney and treating them by ESWL there (pushback/ESWL) offers no advantage over ESWL in situ, as the results are similar, yet morbidity is higher. Blind instrumentation and open surgery have lost all justification.

ESWL and endourology on the same table: a feasible concept?

Within 26 months a total of 4,126 procedures were performed on the ESWL multipurpose table. Forty percent of the procedures were comprised of endourology, 25% functional urinary tract radiology, and 37% ESWL therapy. Biplane fluoroscopy is an extraordinary help for percutaneous interventions. A further advantage is the possibility to perform endourology and ESWL in one session without having to transport the patient. This has facilitated pre- and post-operative ancillary measures in a total of 35.3%. Seventy-six percent of stones greater than 15 mm were managed via indwelling stents. In situ ESWL for ureteral stones has become the therapy of choice in more than 80% of patients due to the availability of radiological localization systems and a complication and failure rate of 20% for the push-and-smash procedure. The multipurpose table is equally successful as the piezoelectric system for ESWL therapy. Drawbacks include operational inconvenience with percutaneous interventions and the necessity to change patient position during ureterorenoscopy and retrograde pyelography. The multipurpose unit used is a valid compromise for ESWL and percutaneous endourology. For purely diagnostic interventions, a standard x-ray table is preferred.

[Clinical relevance of extracorporeal shockwave lithotripsy (ESWL) in choledocholithiasis]

Primary endoscopic removal of bile duct stones is an established method of treatment. However, the extraction of stones is impossible in about 10% of cases despite successful endoscopic papillotomy and manual lithotripsy. Over a period of two years extracorporeal shock-wave lithotripsy (ESWL) was performed in 32 patients. Piezolith 2200, a second generation lithotripter was used, which requires neither analgesia nor anaesthesia for the patient. Localisation of the stones was carried out by means of a 3.5 MH 2 sector scanner. ESWL treatment was successful in 24 of 32 patients (75%). In 6 patients the bile duct stones were too large or too numerous and in 2 patients sonographic localisation was impossible. Out of a total of 131 patients with stones in the biliary tract only 9 (6.8%) needed surgery. Piezoelectric lithotripsy is a safe and effective adjunct procedure for the treatment of bile duct stones which were not extractable by endoscopy.

Piezoelectric extracorporeal shock wave lithotripsy in children

Piezoelectric lithotriptors have by far the smallest focal zone of all lithotriptors. By pinpointing this high pressure zone onto the stone with continuous visualization by ultrasonography throughout treatment, the volume of the kidney exposed to potentially harmful pressures is minimized and radiation hazards are avoided. We treated in this manner 33 renal and 8 ureteral stones in 25 renoureteral units of 22 children 4 months to 14 years old. No child required any other type of primary stone treatment during this period. Piezoelectric lithotripsy is painless and anesthesia was needed in only 11 children too young to cooperate. With a retreatment rate of 40 per cent, all stones were fragmented completely. After treatment only 48 per cent of the children had transient hematuria, which always subsided within 24 hours. Of the children 14 per cent required analgesics and 5 per cent had fever in the postoperative period. One child needed temporary nephrostomy drainage. Otherwise, the passage of stone debris was remarkably smooth and after 3 months 96 per cent of the renoureteral units were free of calculi. Evidence of soft tissue damage, such as skin ecchymosis, perirenal hematoma or retardation of renal growth, was not observed.

Painless piezoelectric extracorporeal lithotripsy

A total of 693 stones in 438 renoureteral units from 426 patients 4 months to 84 years old was treated with a mobile piezoelectric lithotriptor using ultrasound stone localization. Of the units 37 per cent had solitary stones smaller than 1.5 cm. in diameter, (group 1), 32 per cent had multiple stones up to this size (group 2), 21 per cent had stones 1.6 to 2.5 cm. in diameter (group 3) and 10 per cent had calculi larger than 2.5 cm. in diameter (group 4). No sedation or analgesics were necessary in 96.2 per cent of the treatments. Of all stones 97.2 per cent were disintegrated, with 39 per cent of the units requiring repeat treatments usually on an outpatient basis. Of the patients 82 per cent had transient hematuria, 6 per cent had fever and 28 per cent temporarily took some type of analgesics within the first 3 months after treatment. Nine per cent of the patients required postoperative ancillary interventions. After 3 months 92 per cent of the renoureteral units in group 1, 73 per cent in group 2, 74 per cent in group 3 and 50 per cent in group 4 were free of stones. Piezoelectric extracorporeal lithotripsy proved to be as efficient as spark-gap lithotripsy, yet it was essentially painless. Ultrasound localization permits treatment of all renal stones but it restricts lithotripsy of ureteral stones to the most proximal and distal fourths of the ureter.