Structure-function relationship of cytokine induction by lipoteichoic acid from Staphylococcus aureus.

Lipoteichoic acids (LTAs) have been proposed as putative Gram-positive immunostimulatory counterparts to Gram-negative lipopolysaccharides. However, LTA from Staphylococcus aureus, the clinically most frequent Gram-positive pathogen, was inactive after purification. Here, a novel isolation procedure to prepare pure (>99%) biologically active LTA, allowing the first structural analysis by nuclear magnetic resonance and mass spectrometry, is described. A comparison with LTA purified by standard techniques revealed that alanine substituents are lost during standard purification, resulting in attenuated cytokine induction activity. In line with this finding, hydrolysis of alanine substituents of active LTA decimated cytokine induction. LTA represents a major immunostimulatory component of S. aureus.

Bruton's tyrosine kinase together with PI 3-kinase are part of Toll-like receptor 2 multiprotein complex and mediate LTA induced Toll-like receptor 2 responses in macrophages.

Lipoteichoic acid (LTA) of Gram-positive bacteria initiates innate immune responses via Toll-like receptor-2 (TLR2), resulting in the activation of intracellular signaling and production of inflammatory cytokines in macrophages. Although Bruton's tyrosine kinase (Btk) is biologically important molecule implicated in immune regulation and recently in TLR signaling its importance for LTA-TLR2 mediated responses has not been evaluated. In this study, we detected Btk in the LTA signaling complex with TLR2 and PI 3-kinase (PI3K). The constitutive interaction of these proteins was mediated via PI3K Src homology (SH3) -domain. Both Btk and PI3K were activated by LTA stimulation and the LTA induced cytokine expression was differentially modulated by these kinases. LTA induced the activation of nuclear factor kappaB (NFkappaB), however, only Btk inhibition affected the LTA induced Ser536 phosphorylation and DNA-binding of NFkappaB. In conclusion, our results demonstrate that Btk and PI3K occupy important roles in TLR2-induced activation of macrophages, resulting in selective regulation of cytokines.

[Operative management and techniques of mastectomy in female-to-male transsexuals]. / Operatives Management und Techniken der Mastektomie bei Frau-zu-Mann Transsexuellen.

BACKGROUND: Subcutaneous mastectomy in female to male transsexuals is one first important step in gender adjustment. Beside proper surgical technique, operative management of mastectomy procedures is important to allow for an optimised process of gender transformation including all necessary individual operations. METHODS: 126 female-to-male transsexuals were prospectively included in the observation period, all undergoing a step 1 operation of gender adjustment. The mastectomy procedure is conventionally embedded in an overall approach for gender transformation and was regularly combined with procedures like colpectomy, extension of the urethra as well as hysterectomy and ovariectomy. 4 different methods for mastectomy were introduced at our institution, depending on and adjusted to the breast volume, grade of breast ptosis, the breast size and envelope and skin elasticity. For patient evaluation a standardised survey was conducted using a semiquantitative score (1-4) for grading aesthetic results and nipple sensibility. RESULTS: Between 2006 and 2009 a total of 126 patients underwent a step 1 procedure of gender adjustment, 63 had mastectomy and 29 a revision procedure after external prior mastectomy. In 64/126 (50.8%) mastectomy was performed using a one-third edge cut, 30/126 (23.8%) were operated by a submammarian approach and pedicled nipples technique, in another 22/126 cases (17.5%) mastectomy was performed using circular tightening and 10/126 (7.9%) received freely transplanted nipples. For improving the aesthetic results, additional procedures were performed on 29 patients (46%). The patient survey revealed a high level of satisfaction with the aesthetic result, 42/50 (84%) of the patients rated results as good or very good. CONCLUSIONS: We newly introduced an operative concept of mastectomy being embedded and adjusted in an overall approach for gender adjustment (Munich Modular Operative Kit; MMOK). Using the presented individualised surgical techniques of mastectomy, all procedures were conducted in a very scar-saving manner, however, a higher rate of correction procedures was necessary to individually adjust skin shrinking and thereby optimising the prior aesthetic results. The new Munich Modular Operative Kit allows for gender reassignment including breast corrections usually using 4 operative steps.

[Vaginal hysterectomy and bilateral adnexectomy for female to male transsexuals in an interdisciplinary concept]. / Vaginale Hysterektomie und beidseitige Adnexektomie in interdisziplinärem Konzept bei Frau zu Mann - Transsexualismus.

BACKGROUND: FtM reassignment surgeries are rare and require interdisciplinary cooperation of plastic surgeons and gynaecologists. There are only few homogeneous data and standardised recommendations about the operative access to hysterectomy and bilateral adnexectomy of FtM transsexual patients. PATIENTS AND METHODS: Between 2006 and 2009 106 FtM transsexuals were hysterectomised in an interdisciplinary concept of plastic surgeons and gynaecologists in the Frauenklinik des Rotkreuzklinikums München. Firstly plastic surgeons performed a complete colpectomy, after that a vaginal hysterectomy with bilateral adnexectomy was carried out by gynaecologists. Simultaneously plastic surgeons performed a bilateral subcutaneous adenomammectomy on the FtM patients, and the removed vaginal tissue was prepared for preforming a new urethra. In the next step the vagina was closed by plastic surgeons and the urethra preformed. RESULTS: In 103 of 106 cases (97.2%) hysterectomy and bilateral adnexectomy were performed through the vagina. The complication rate was 5.4%. The vaginal hysterectomy and the bilateral adnexectomy lasted 52 min on average. DISCUSSION: Vaginal, abdominal or laparoscopic approaches provide possible operative access for hysterectomy and bilateral adnexectomy in FtM transsexuals. A data comparison shows that the rate of complications with our FtM transsexuals operated through the vagina was not higher than that with non-transsexual patients operated through the vagina for benign illnesses of the uterus. There are advantages of the vaginal hysterectomy for patients concerning a reduced occurrence of scars and avoiding injuries of the rectus muscle as an important precondition for phalloplasty. The bilaterally performed subcutaneous adenomammectomy and the preparation of the removed vaginal tissue for the preformation of the urethra can be carried out simultaneously, meaning that the time for operation and the stay in hospital will be shortened and costs will be reduced as well. The problem of a relatively narrow field for the operation will be minimised or even solved by the preceding colpectomy. CONCLUSION: Realising the vaginal hysterectomy with bilateral vaginal adnexectomy after performing a total colpectomy from our point of view is the optimal choice concerning operative methods for reassignment surgeries.

Induction of cross-tolerance by lipopolysaccharide and highly purified lipoteichoic acid via different Toll-like receptors independent of paracrine mediators.

Exposure of macrophages to LPS induces a state of hyporesponsiveness to subsequent stimulation with LPS termed LPS desensitization or tolerance. To date, it is not known whether similar mechanisms of macrophage refractoriness are induced on contact with components of Gram-positive bacteria. In the present study, we demonstrate that pretreatment with highly purified lipoteichoic acid (LTA) results in suppression of cytokine release on restimulation with LTA in vitro and in vivo in both C3H/HeN and C3H/HeJ mice, but not in macrophages from Toll-like receptor (TLR)-2-deficient mice. Furthermore, desensitization in response to LPS or LTA exposure also inhibits responses to the other stimulus ("cross-tolerance"), suggesting that signaling pathways shared by TLR2 and TLR4 are impaired during tolerance. Finally, we show that LPS- or LTA-induced cross-tolerance is not transferred to hyporesponsive cells cocultured with LPS/LTA-responsive macrophages, showing that soluble mediators do not suffice for tolerance induction in neighboring cells.