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Liedl B, Barba M, Wenk M. [Pelvic floor reconstruction-update 2024: prolapse-associated symptoms and their treatment]. UROLOGIE (HEIDELBERG, GERMANY) 2024; 63:43-50. [PMID: 38153429 DOI: 10.1007/s00120-023-02247-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 11/22/2023] [Indexed: 12/29/2023]
Abstract
Pelvic organ prolapse (POP) and associated symptoms of urinary incontinence, fecal incontinence, obstructive micturition, defecation, and pain are frequent and a widespread disease with relevant reduction of quality of life and high costs. New insights into functional anatomy and pathophysiology of these pelvic floor dysfunctions let us recognize how ligamentous laxities/defects lead to these dysfunctions. Results of the PROpel study (ClinicalTrials.gov-Identifier: NCT00638235) are shown in which a detailed observation of symptoms (patient-related outcome measures) pre- and postoperatively was performed. Ligamentous vaginal repair of POP enables symptom cure in high percentages for urinary urge incontinence (up to 82%), nocturia (up to 92%), obstructive micturition (up to 87%), fecal incontinence (58-72%), obstructive defecation (71-84%), and pain (53-90%), if caused by POP. Women with POP‑Q stage 2 have similar symptom frequencies as women with POP‑Q stage 3-4, and also similar cure rates of their symptoms. If good anatomical prolapse repair (in responders) was achieved, the cure rates for obstructive micturition, urinary urgency incontinence, and nocturia were significantly higher than in those women with less effective surgical repair. In the future, pelvic floor surgery should have symptom cure as the primary objective and should lead to improved quality of life. The different, currently performed techniques for POP repair have to be investigated concerning this matter.
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Massoth C, Zarbock A, Wenk M. [Non-cardiac surgery in adults with congenital heart defects : Most important parameters in anesthesia management]. Anaesthesist 2019; 68:245-258. [PMID: 30911773 DOI: 10.1007/s00101-019-0575-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
BACKGROUND Adults with congenital heart disease (CHD) represent an increasing proportion of patients undergoing non-cardiac surgery. OBJECTIVE To identify the most important parameters for management of anesthesia. MATERIAL AND METHODS Evaluation and discussion of the current original research and guideline recommendations. RESULTS There are approximately 300,000 patients with CHD living in Germany. The preoperative evaluation is an important influencing factor affecting perioperative morbidity and mortality. Echocardiography is the key instrument for identifying cardiac conditions predisposing to adverse events. The subdivision of CHD into lesions with left-to-right shunt, obstructive lesions and complex congenital heart diseases facilitates the classification of the pathophysiology. CONCLUSION Decisive for the perioperative outcome of patients with CHD are the identification of high-risk patients, understanding of the individual situation with respect to the underlying pathophysiology and the intraoperative maintenance of cardiac output.
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Heinz FX, Stiasny K, Holzmann H, Kundi M, Sixl W, Wenk M, Kainz W, Essl A, Kunz C. Emergence of tick-borne encephalitis in new endemic areas in Austria: 42 years of surveillance. ACTA ACUST UNITED AC 2015; 20:9-16. [PMID: 25860391 DOI: 10.2807/1560-7917.es2015.20.13.21077] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Human infections with tick-borne encephalitis (TBE)virus are a public health concern in certain regions of Europe, central and eastern Asia. Expansions of endemic areas and increased incidences have been associated with different factors including ecological changes supporting tick reproduction, socioeconomic changes increasing human outdoor activities and climatic changes favouring virus circulation in natural foci. Austria is among the most strongly affected countries in Central Europe, but the annual number of cases has strongly declined due to vaccination. Here,we have analysed changes of the incidence of TBE in the unvaccinated population of all federal states of Austria over a period of 42 years. The overall incidence in Austria has remained constant, but new strongly affected endemic regions have emerged in alpine valleys in the west of Austria. In parallel, the incidence in low-land regions in the north-east of the country is decreasing. There is no evidence for a shift to higher altitudes of infection sites in the traditional TBE zones,but the average altitudes of some newly established endemic areas in the west are significantly higher. Our analyses underscore the focal nature of TBE endemic areas and the potential of TBE virus to emerge in previously unaffected regions.
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Sharman M, Ong D, Verdile G, Munch G, Wenk M, Halliwell B, Martins R. Effect of nutritional supplement therapies in the prevention of Alzheimer’s disease in a transgenic mouse model. JOURNAL OF NUTRITION & INTERMEDIARY METABOLISM 2014. [DOI: 10.1016/j.jnim.2014.10.113] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022] Open
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Ariotti N, Fernandez-Rojo M, Zhou Y, Hill M, Rodkey T, Inder K, Tanner L, Wenk M, Hancock J, Parton R. Caveolae regulate the nanoscale organization of the plasma membrane to remotely control Ras signaling. J Gen Physiol 2014. [DOI: 10.1085/jgp.1434oia10] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
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Pöpping D, Van Aken H, Brodner G, Wenk M. It is not the epidural that is dangerous, but the person who gives it. Br J Anaesth 2014; 112:392-3. [DOI: 10.1093/bja/aet575] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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Wenk M, Lennon M. Training and supervision remain the key. Minerva Anestesiol 2013; 79:453. [PMID: 23306404] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
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Wenk M, Pöpping D, Chapman G, Grenda H, Ledowski T. Long-term quality of sleep after remifentanil-based anaesthesia: a randomized controlled trial. Br J Anaesth 2013; 110:250-7. [DOI: 10.1093/bja/aes384] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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Lennon M, Zaw NN, Pöpping DM, Wenk M. Procedural complications of central venous catheter insertion. Minerva Anestesiol 2012; 78:1234-1240. [PMID: 22699699] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
BACKGROUND Central venous catheters (CVC) have complication rates as high as 20% and are associated with significant morbidity and mortality. In this study we wished to determine the incidence of procedural related complications at different venous access sites as well as the impact of ultrasound (US) use, operator experience and level of supervision of trainees in a prospective observational study. METHODS Five hundred consecutive patients undergoing elective CVC insertion were prospectively followed. Data with regards to US use, operator experience, level of supervision, site of insertion and procedural complications were collected. RESULTS The overall rate of procedural complications was 19.5%. Operators with <25 insertions caused significantly more complications (25.2% vs. 13.6%). Arterial punctures occurred significantly more frequently when US was not used (7.2 vs. 2.1%) and at the subclavian site (8% vs. 1.6%). Higher levels of supervision were significantly associated with a decreased number of complications (10.7% vs. 23.8%). Subclavian vein as access point for the CVC resulted in significantly more overall complications (29.2% vs. 17.7%). Inexperienced operators combined with SCV approach were significant predictors for increased procedural-related complications. CONCLUSION Immediate procedural-related complications during CVC insertion are common. To reduce the incidence of procedural-related complications we advocate multiple strategies to assure central venous cannulation safety: 1) the internal jugular vein should be the primary target vessel; 2) trainees with <25 previous catheter insertions should be supervised at all times; 3) ultrasound may reduce the incidence of procedural-related complications.
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Baig S, Vasoo S, Teh B, Ho S, Kothandaraman N, Lu J, Wenk M, Arquio C, Kale A, Su L, Biswas A, Choolani M. Immunomodulation by placental microvesicles in adverse pregnancy outcomes (preeclampsia and recurrent pregnancy loss). J Reprod Immunol 2012. [DOI: 10.1016/j.jri.2012.03.268] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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Wenk M, Pöpping DM, Hillyard S, Albers H, Möllmann M. Intraoperative thrombolysis in a patient with cardiopulmonary arrest undergoing caesarean delivery. Anaesth Intensive Care 2011; 39:671-4. [PMID: 21823388 DOI: 10.1177/0310057x1103900422] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Thromboembolic events during pregnancy remain a major cause of morbidity and mortality with possible catastrophic sequelae for the patient. The decision whether to use high-risk therapeutic thrombolytics during pregnancy or perinatally is complicated and many considerations pertain. We report on the thrombolytic management of a 34-year-old woman who had an asystolic cardiac arrest secondary to massive pulmonary embolism while undergoing emergency caesarean delivery. The patient was thrombolysed during successful cardiopulmonary resuscitation. Return of spontaneous circulation was accompanied by massive uterine bleeding. Instead of performing a postpartum hysterectomy, the uterus was preserved through continuous manual pressure and packing for four hours by the obstetric team until haemostasis was achieved. The patient survived and was later discharged without any major neurological deficit.
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Nieschlag E, Vorona E, Wenk M, Hemker AK, Kamischke A, Zitzmann M. Hormonal male contraception in men with normal and subnormal semen parameters. ACTA ACUST UNITED AC 2011; 34:556-67. [DOI: 10.1111/j.1365-2605.2011.01142.x] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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Krämer S, Wenk M, Fischer G, Möllmann M, Pöpping DM. Continuous spinal anesthesia versus continuous femoral nerve block for elective total knee replacement. Minerva Anestesiol 2011; 77:394-400. [PMID: 21483383] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
BACKGROUND Continuous spinal analgesia (CSA) and continuous femoral nerve blockade (CFNB) are well-established procedures for postoperative pain relief. This study compares the efficacy, adverse effects and complications associated with these two analgesic methods in patients undergoing total knee arthroplasty (TKA). METHODS Data were analyzed from consecutive patients undergoing TKA under either CSA or spinal anesthesia plus CFNB. Quality of analgesia was assessed based on opioid consumption and pain intensity (visual analogue scale [VAS] where 0=no pain and 10=utmost imaginable pain) until postoperative day 4. In addition, joint mobility was assessed, and any adverse reactions or side effects were noted. RESULTS Sixty-two patients had satisfactory postoperative pain relief, and maximum pain scores were reported between 12 and 24 hrs. Median pain scores in the CSA group were significantly lower than those in the CFNB group (1.0 [0.9-1.9] vs. 2.0 [1.5-3.6] for resting pain and 2.0 [1.7-3.1] vs. 5.0 [3.0-5.5] for dynamic pain, respectively; P<0.001 for days 0 and 1; P<0.05 for all other days). Piritramide consumption was significantly higher in the CFNB group (P<0.01). There were no significant differences between the groups for postoperative mobility of the joint or patient satisfaction. CONCLUSION Both methods demonstrated analgesic efficacy after total knee arthroplasty, although there was less pain severity and opioid consumption use reported with continuous spinal analgesia. However, the use of continuous spinal analgesia is limited by concerns about the risk profile and absence of approved devices for continuous intrathecal infusion.
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Wenk M, Gurlit S, Pöpping DM, Möllmann M. Teaching epidural insertion: a modified approach to combined spinal-epidural anaesthesia. Br J Anaesth 2011; 106:420-1. [PMID: 21317235 DOI: 10.1093/bja/aer021] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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Zitzmann M, Vorona E, Wenk M, Saad F, Nieschlag E. Testosterone administration decreases carotid artery intima media thickness as a marker of impaired vascular integrity in middle-aged overweight men. JOURNAL OF MEN'S HEALTH 2009. [DOI: 10.1016/j.jomh.2009.08.059] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
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Abstract
This review illustrates the principle of hormonal male contraception and gives an overview of current trials aiming at the development of a marketable hormonal contraceptive for men. The principle of male hormonal contraception is based on strong suppression of gonadotropins in order to arrest spermatogenesis at the spermatogonial stem cell level, thus leading to azoospermia or severe oligozoospermia. Until now, it has not been possible to interrupt spermatogenesis effectively without simultaneously inhibiting the production of androgens by Leydig cells, resulting in a deficiency of extra-testicular androgens. Therefore, testosterone needs to be replaced. By administering exogenous testosterone alone azoospermia can be reached in East Asians, whereas azoospermia is only achieved in two-thirds of Caucasian volunteers so that in these men an additional agent is required. Currently injectable testosterone combined with gestagens or administered as implants are being tested for possible licensing. Although scrotal and non-scrotal testosterone patches, orally administered testosterone undecanoate and testosterone gels are generally well tolerated and provide stable testosterone levels in the normal range, their use showed generally disappointing efficacy due to insufficient gonadotropin suppression. Further large multi-centre studies are required to establish the contraceptive efficacy of the most promising steroid combinations.
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Wenk M, Pöpping D, Henning M, Wenk M, Liljenqvist U, Möllmann M. Creation of a head and face protection device for children undergoing procedures in prone position. Paediatr Anaesth 2009; 19:587-92. [PMID: 19645977 DOI: 10.1111/j.1460-9592.2009.03008.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
BACKGROUND Positioning the head of patients undergoing procedures in lateral or prone position remains a difficult task for the anesthesiologists. Associated risks have attracted increasing attention because they range from minor facial soft tissue injuries to catastrophic complications such as stroke or postoperative blindness. Earlier, we reported on the use of a boxing sports helmet for simple and easy positioning of the head. However, as available helmets are limited in sizes and materials, that system is not easily transferable to children. Therefore, we sought to create a face and head protection device for children undergoing procedures in prone position. METHODS/MATERIALS We re-engineered a standard boxing sports helmet making it suitable as an on-head support cushion. By using WHO standard growth charts, various sizes were calculated and prototypes of different foam materials produced. Facial surface pressures were measured in 15 volunteers. RESULTS A lightweight foam-based face mask was created. Minimum necessary foam thickness was 2.5 cm. Different materials were tested and pressure in different facial zones never exceeded 30 mmHg. CONCLUSION Bringing a face protection device onto the patient's face instead of placing the face into support cushions is an elegant way of keeping control over airway devices and providing support for facial structures in various positions simultaneously. Skin surface pressure on facial structures remained low due to the specific mask design and choice of foam materials, which could lead to decreased incidences of undesired sequelae of prone position such as skin damage or even more devastating complications.
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Wenk M, Pöpping DM. Feasibility of infusion pumps for continuous spinal administration of local anesthetics in post-operative pain therapy. Acta Anaesthesiol Scand 2009; 53:634-40. [PMID: 19419358 DOI: 10.1111/j.1399-6576.2009.01928.x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
BACKGROUND AND OBJECTIVES For completion of perioperative care and for general ethical considerations, any intraoperatively used catheter technique should be utilizable for post-operative pain therapy. Continuous spinal anesthesia (CSA) is an established form of local anesthetic application. However, for its use in post-operative therapy, infusion pumps are required that are technically able to deliver low rates and are distinctive in design to avoid possible pump or medication swaps. Because of a lack of devices specifically designed for CSA, we investigated the potential deployability of infusion pumps for post-operative pain therapy via CSA microcatheters, which were originally designed and approved for different applications. METHODS The accuracy of infusion rates of three different pumps was measured in a liquor model environment. Furthermore, we investigated safety and user-friendliness by interviewing 30 anesthesiologists and 15 pain nurses. RESULTS Except for the first hour of infusion, all pumps provided comparable and adequate flow profiles. However, interviews revealed significant risk factors for all pumps in terms of swapping devices, lines or medications and misprogramming the units. DISCUSSION All pumps tested were technically able to deliver accurate flow rates; however, because the non-CSA-specific design involves the risk of medication overdosage and syringe swaps, none of the systems tested can be recommended for routine use in post-operative CSA, irrespective of the fact that it was an off-label application anyway. Therefore, to ensure patient safety, continuous spinal administration of local anesthetics via microcatheters is a questionable method of post-operative pain therapy as long as non-specific pumps are used.
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Wenk M, Waurick R, Schotes D, Wenk M, Gerdes C, Van Aken HK, Pöpping DM. Simulation-based medical education is no better than problem-based discussions and induces misjudgment in self-assessment. ADVANCES IN HEALTH SCIENCES EDUCATION : THEORY AND PRACTICE 2009; 14:159-71. [PMID: 18214702 DOI: 10.1007/s10459-008-9098-2] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/07/2007] [Accepted: 01/03/2008] [Indexed: 05/10/2023]
Abstract
Simulation-based teaching (SBT) is increasingly used in medical education. As an alternative to other teaching methods there is a lack of evidence concerning its efficacy. The aim of this study was to evaluate the potency of SBT in anesthesia in comparison to problem-based discussion (PBD) with students in a randomized controlled setting. Thirty-three fourth-year medical students attending a curricular anesthesiology course were randomly allocated to either a session of SBT or a session of PBD on an emergency induction method. Ten days later all students underwent examination in a simulator. The performance of each student was evaluated by weighted tasks, established according to a modified Delphi process. Confidence and a multiple-choice questionnaire were additionally performed pre- and post-intervention. A total of 32 students completed the study. Participants in the SBT group presented with significantly higher self-assessment scores after the intervention than students in the PBD group. However, students in the SBT group achieved only slightly and statistically insignificantly higher scores in the theoretical and simulator examination (p > 0.05) with only a moderate effect size of d = 0.52. The current study demonstrates that both PBD and SBT lead to comparable short-term outcomes in theoretical knowledge and clinical skills. However, undesirably, SBT students overrated their anticipated clinical abilities and knowledge improvement.
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Ulrich RG, Heckel G, Pelz HJ, Wieler LH, Nordhoff M, Dobler G, Freise J, Matuschka FR, Jacob J, Schmidt-Chanasit J, Gerstengarbe FW, Jäkel T, Süss J, Ehlers B, Nitsche A, Kallies R, Johne R, Günther S, Henning K, Grunow R, Wenk M, Maul LC, Hunfeld KP, Wölfel R, Schares G, Scholz HC, Brockmann SO, Pfeffer M, Essbauer SS. Nagetiere und Nagetierassoziierte Krankheitserreger. Bundesgesundheitsblatt Gesundheitsforschung Gesundheitsschutz 2009; 52:352-69. [DOI: 10.1007/s00103-009-0798-4] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Wenk M, Jockenhöfer D, Pöpping DM, Liljenqvist U, Möllmann M. [Scoliosis surgery in children from the viewpoint of anaesthesiology]. DER ORTHOPADE 2008; 38:170-5. [PMID: 19093097 DOI: 10.1007/s00132-008-1361-y] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
Anaesthesia for scoliosis surgery in children is a challenge for the paediatric anaesthesiologist. The large range of underlying pathologies causing deranged physiology in an inhomogeneous patient group ranging from neonates to adolescents necessitates diligent and individual preparation for each case. Due to the invasiveness of the operation demanding anaesthetic care is necessary. This review highlights current approaches to monitoring, anaesthetic regimen, positioning of the patient, blood conservation and transfusion, age-related pathophysiology, ventilation and postoperative pain therapy. The introduction of neurophysiologic spinal cord monitoring requires certain adaptations of the anaesthetic regimen to suit technological advances.
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Möllmann M, Henning M, Liljenqvist U, Wenk M. A foam-cushion face mask and a see-through operation table: a new set-up for face protection and increased safety in prone position. Br J Anaesth 2007; 99:597-8. [PMID: 17827190 DOI: 10.1093/bja/aem248] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Chan P, Mahler J, Travlos G, Nyska A, Wenk M. Induction of thyroid lesions in 14-week toxicity studies of 2 and 4-methylimidazole in Fischer 344/N rats and B6C3F1 mice. Arch Toxicol 2005; 80:169-80. [PMID: 16180012 DOI: 10.1007/s00204-005-0018-4] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2005] [Accepted: 07/19/2005] [Indexed: 10/25/2022]
Abstract
Fifteen-day and 14-week studies of 2-methylimidazole (2MI) and 4-methylimidazole (4MI) were conducted because of widespread human exposure via ingestion of food products containing the compounds and lack of toxicity data. Groups of five male and five female Fischer rats and B6C3F1 mice were administered 2MI by dosed feed at 0, 1,200, 3,300, or 10,000 ppm or 4MI at 0, 300, 800, or 2,500 ppm for 15 days, and groups of 10 male and 10 female Fischer rats and B6C3F1 mice were administered 2MI or 4MI at 0, 625, 1,250, 2,500, 5,000 or 10,000 ppm for 14 weeks. In the 15-day studies, 2MI induced thyroid follicular-cell hyperplasia and pituitary pars-distalis hypertrophy in rats and thyroid follicular-cell hypertrophy and spleen hematopoietic-cell proliferation in mice; 4MI induced no histopathological changes in rats and mice. In the 14-week studies, 2MI increased concentrations of thyroid-stimulating hormone (TSH) and decreased those of thyroxine (T(4)) and triiodothyroxine (T(3)) in male and female rats according to the dosage. Incidences of diffuse follicular-cell hyperplasia of the thyroid gland increased significantly in male rats exposed to 1,250 ppm or greater and female rats exposed to 2,500 ppm or greater. Thyroid follicular-cell adenoma was diagnosed in two males in the 10,000-ppm group. A dose-related anemia occurred in female rats. In mice, follicular-cell hypertrophy of the thyroid gland, anemia, splenic hematopoietic-cell proliferation, and hemosiderin in kidney tubules appeared. In rats, 4MI induced tremors and ataxia in the high-dose groups. Serum T(3), T(4), and TSH levels were not altered, and no thyroid lesions occurred. Anemia, hepatocytic vacuolation, testicular degeneration, and prostatic atrophy were observed. In mice, anemia, liver cytoplasmic vacuolization, and renal degeneration and dilation occurred. Our studies demonstrated that, in rats and mice, 2MI induces thyroid hyperplasia and hypertrophy, and both 2MI and 4MI induce anemia; 2MI induces thyroid follicular-cell adenoma in male rats.
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Wenk M, Herbst R, Hoeger D, Kretschmar M, Lubsen NH, Jaenicke R. Gamma S-crystallin of bovine and human eye lens: solution structure, stability and folding of the intact two-domain protein and its separate domains. Biophys Chem 2000; 86:95-108. [PMID: 11026675 DOI: 10.1016/s0301-4622(00)00161-7] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
Human and bovine gammaS-crystallin (HgammaS and BgammaS) and their isolated N- and C-terminal domains were cloned and expressed as recombinant proteins in E. coli. HgammaS and BgammaS are found to be authentic according to their spectral and hydrodynamic properties. Both full-length proteins and isolated domains are monomeric and exhibit high thermal and pH stabilities. The thermodynamic characterization made use of chemically and thermally-induced equilibrium unfolding transitions at varying pH. In spite of its exemplary two-domain structure, gammaS-crystallin does not show bimodal unfolding characteristics. In the case of BgammaS, at pH 7.0, the C-terminal domain is less stable than the N-terminal one, whereas for HgammaS the opposite holds true. Differential scanning calorimetry confirms the results of chemically-induced equilibrium unfolding transitions. Over the whole pH range between 2.0 and 11.5, HgammaS-crystallin and its isolated domains (HgammaS-N and HgammaS-C) follow the two-state model. The two-state unfolding of the intact two-domain protein points to the close similarity of the stabilities of the constituent domains. Obviously, interactions between the domains do not contribute significantly to the overall stability of gammaS-crystallin. In contrast, the structurally closely related gammaB-crystallin owes much of its extreme stability to domain interactions.
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