Laser in Urology – State of the Art

A review of the papers presented at the 16th Annual Meeting of Deutsche Gesellschaft für Lasermedizin (June 17 and 18, 2007 in Munich) and the last two years’ publications show the still raising interest in urological laser applications. Lasers are used for the treatment of various benign and malignant urological disorders such as benign prostatic hyperplasia, stone disease, strictures and tumors of the urinary tract, and intravesical foreign bodies. Laser prostatectomy has successfully entered the era of prospective randomized studies. Ureteroscopic Holmium:YAG Laser lithotripsy has been generally accepted first choice for treatment of upper urinary stones. Regarding the large number and high quality of publications in the field of urological laser application, we are looking forward to an exciting session during our 16th Annual Meeting of DGLM.     

Laser in urology – State of the art

A review of the papers presented at the 15th Annual Meeting of Deutsche Gesellschaft für Lasermedizin (June 15 and 16 in Munich) and the last 2 years’ publications show the still raising interest in urological laser applications. Lasers are used for the treatment of various benign and malignant urological disorders, such as stone disease, benign prostatic hyperplasia, strictures of the urethra and ureter, and carcinoma of the penis and urinary tract. We are looking forward to an exciting and productive discussion between experts during our scientific meeting.

Zusammenfassung

Das Interesse von Klinikern und Wissenschaftlern an Laseranwendungen in der Urologie ist so groß wie noch nie. Diese minimal-invasiven Therapieverfahren bieten breite Einsatzmöglichkeiten zur Behandlung zahlreicher maligner und benigner urologischer Erkrankungen, wie dem Harnsteinleiden, dem BPH-Syndrom, Strikturen der ableitenden Harnwege sowie Karzinomen des Harntraktes und des Penis. Ein Überblick über die Literatur der letzten zwei Jahre und die bei der 15. Jahrestagung der Deutschen Gesellschaft für Lasermedizin präsentierten Vorträge zeigen die hohe Aktualität dieses Themas. Wir freuen uns auf eine spannende produktive Diskussion bei unserem Meeting.     

Adipose Dipeptidyl Peptidase-4 and Obesity: Correlation with insulin resistance and depot-specific release from adipose tissue in vivo and in vitro

OBJECTIVE

To study expression of the recently identified adipokine dipeptidyl peptidase-4 (DPP4) in subcutaneous adipose tissue (SAT) and visceral adipose tissue (VAT) of patients with various BMIs and insulin sensitivities, as well as to assess circulating DPP4 in relation to obesity and insulin sensitivity.

RESEARCH DESIGN AND METHODS

DPP4 expression was measured in SAT and VAT from 196 subjects with a wide range of BMIs and insulin sensitivities. DPP4 release was measured ex vivo in paired biopsies from SAT and VAT as well as in vivo from SAT of lean and obese patients. Circulating DPP4 was measured in insulin-sensitive and insulin-resistant BMI-matched obese patients.

RESULTS

DPP4 expression was positively correlated with BMI in both SAT and VAT, with VAT consistently displaying higher expression than SAT. Ex vivo release of DPP4 from adipose tissue explants was higher in VAT than in SAT in both lean and obese patients, with obese patients displaying higher DPP4 release than lean controls. Net release of DPP4 from adipose tissue was also demonstrated in vivo with greater release in obese subjects than in lean subjects and in women than in men. Insulin-sensitive obese patients had significantly lower circulating DPP4 than did obesity-matched insulin-resistant patients. In this experiment, DPP4 positively correlated with the amount of VAT, adipocyte size, and adipose tissue inflammation.

CONCLUSIONS

DPP4, a novel adipokine, has a higher release from VAT that is particularly pronounced in obese and insulin-resistant patients. Our data suggest that DPP4 may be a marker for visceral obesity, insulin resistance, and the metabolic syndrome.Obesity is an increasing health issue worldwide and an economical burden, and as the hallmark of the metabolic syndrome the obese state is frequently associated with the development of chronic diseases, including type 2 diabetes (1,2). The association between the epidemics of obesity and diabetes has promoted research on the endocrine link between lipid and glucose homeostasis, demonstrating that adipose tissue is an endocrine organ releasing various adipokines. A complex interorgan crosstalk scenario between adipose tissue and other central and peripheral organs underlies the progression of obesity-related metabolic disorders, with adipose tissue being a key player in this scenario (3). The current view of the role of expanded adipose tissue in obesity identifies adipokines as a potential link between obesity and insulin resistance (4). This link has stimulated a further characterization of the adipocyte secretome by means of diverse proteomic profiling approaches, leading to the discovery of such novel adipokines as dipeptidyl peptidase-4 (DPP4) (5).DPP4 is a transmembrane glycoprotein and exoprotease that cleaves N-terminal dipeptides from various substrates (6). Most importantly, DPP4 also cleaves and inactivates the incretins glucagon-like peptide 1 (GLP-1) and gastric inhibitory polypeptide. In this context, DPP4-inhibitors are in clinical use as antidiabetic drugs to improve glycemic control by stimulating pancreatic insulin secretion and suppressing glucagon production (7). We recently demonstrated that adipocytes release DPP4 in a differentiation-dependent manner (5). Circulating DPP4 concentrations are increased in obese subjects and correlate with fasting plasma insulin, leptin, and adipocyte size in subcutaneous adipose tissue (SAT); however, the tissue source of circulating DPP4 is not known. This study aimed to assess DPP4 expression and release in paired biopsies of SAT and visceral adipose tissue (VAT) of lean and obese patients and of patients with or without impaired glucose tolerance, as well as DPP4 release from adipose tissue in vivo. Because circulating DPP4 is increased in obese patients with the metabolic syndrome (5), we hypothesized that DPP4 expression and release in VAT are more prominent than in SAT and that VAT DPP4 could be a marker for insulin sensitivity.     

Protective effect of gallic acid and Syzygium cumini extract against oxidative stress-induced cellular injury in human lymphocytes

Context: Syzygium cumini (Myrtaceae) presents antioxidant, anti-inflammatory, hypoglycemic and antibacterial effects; however, the cellular and molecular mechanisms of action in the immune system are not yet completely elucidated. Objective: This study evaluates the in vitro effect of gallic acid and aqueous S. cumini leaf extract (ASc) on adenosine deaminase (ADA) and dipeptidyl peptidase IV (DPP-IV) activities, cell viability and oxidative stress parameters in lymphocytes exposed to 2, 2′-azobis-2-amidinopropane dihydrochloride (AAPH). Materials and methods: Lymphocytes were incubated with ASc (100 and 500?µg/ml) and gallic acid (50 and 200?µM) at 37?°C for 30?min followed by incubation with AAPH (1?mM) at 37?°C for 2?h. After the incubation time, the lymphocytes were used for determinations of ADA, DPP-IV and lactate dehydrogenase (LDH) activities, lipid peroxidation, protein thiol (P-SH) group levels and cellular viability by colorimetric methods. Results: (i) HPLC fingerprinting of ASc revealed the presence of catechin, epicatechin, rutin, quercitrin, isoquercitrin, quercetin, kaempferol and chlorogenic, caffeic, gallic and ellagic acids; (ii) for the first time, ASc reduced the AAPH-induced increase in ADA activity, but no effect was observed on DPP-IV activity; (iii) ASc increased P-SH groups and cellular viability and decreased LDH activity, but was not able to reduce the AAPH-induced lipid peroxidation; (iv) gallic acid showed less protective effects than ASc. Discussion and conclusion: ASc affects the purinergic system and may modulate adenosine levels, indicating that the extract of this plant exhibits immunomodulatory properties. ASc also may potentially prevent the cellular injury induced by oxidative stress, highlighting its cytoprotective effects.     

Predicting intentions and adherence behavior in the context of organ transplantation: gender differences of provided social support

ObjectivesMedication non-adherence is a common problem in organ transplantation patients with severe consequences for the patients' health. This study aimed at examining the determinants of intention formation and adherence behavior based on the Theory of Planned Behavior (TPB). Moreover, to account for the role of patients' partners, provided social support by partners was included. Here, support provided by female partners was hypothesized to be more effective than support provided by male partners.MethodThis cross-sectional study comprised 121 heart, liver, lung, and kidney transplant recipients (n = 81 men; mean age = 54.32, SD = 13.32) and their partners (mean age = 51.99, SD = 13.67). Patients completed a questionnaire with TPB variables and a validated measure of self-reported adherence. Partners reported their provided social support with regard to medication adherence of the patients.ResultsFor the prediction of intention to adhere to medication, the non-significant main effect of provided social support was qualified by partners' gender: Support provided by women was positively related to patients' intention to adhere, whereas support provided by men was slightly negatively related to the intention to adhere in their female spouses. Intentions in turn emerged together with relationship quality as the most important predictor of adherence behavior.ConclusionThe beneficial effects of support provided by women could be replicated within the framework of the TPB in the context of organ transplantation. Interventions should focus on increasing the effectiveness of support provision of male partners and on promoting relationship quality.     

Low prevalence of antibodies to glucose‐6‐phosphate isomerase in patients with rheumatoid arthritis and a spectrum of other chronic autoimmune disorders

Objective

Arthritis in the K/BxN mouse model results from pathogenic immunoglobulins that recognize glucose‐6‐phosphate isomerase (GPI), a glycolytic enzyme residing in the cytoplasm of all cells. Antibodies directed against GPI can, alone, transfer arthritis to healthy recipients. Previous experiments have revealed significant titers of anti‐GPI antibodies in the serum of many patients with rheumatoid arthritis (RA). We evaluated the generality of these observations in cohorts of patients with 12 different arthritic and chronic autoimmune diseases and in population‐matched healthy control subjects.

Methods

Anti‐GPI antibodies were assayed in 811 individual serum samples by enzyme‐linked immunosorbent assay with 2 forms of GPI, recombinant and native. Results were confirmed by immunoblotting.

Results

Several patients had significantly elevated anti‐GPI antibody titers, but without the prevalence or the specificity reported previously. Only 15% of RA patients had anti‐GPI antibodies (range 12–29% in different cohorts), with a higher prevalence in patients with active disease. Psoriatic arthritis, undifferentiated arthritis, and spondylarthropathy patients also displayed anti‐GPI antibodies at similar frequencies (12–25%). Similar titers were detected in a proportion (5–10%) of control subjects or patients with Crohn's disease or sarcoidosis. Very high titers were found in rare cases of RA and systemic lupus erythematosus.

Conclusion

No disease‐specific pattern of antibody positivity to GPI was apparent. While the antibody‐mediated mechanism at play in the mouse model may exemplify a generic mechanism for some forms of arthritis in humans, GPI itself does not appear to be a target common to the majority of RA patients.