Klaus-Peter Thon

Telomere length in different tissues of elderly patients.

Telomeres are supposed to play a role in cellular aging and might contribute to the genetic background of human aging and longevity. During the past few years telomere length has been measured in various human tissues. However, very little is known about the individual telomere loss in different tissues from the same donor. Therefore we have measured telomere restriction fragment (TRF) length in three unrelated tissues (leukocytes, skin and synovial tissue) of nine elderly patients (age range 73-95 years old). Dependent on the tissue specific proliferation rate we have found significantly shorter telomeres (6546+/-519 bp, mean +/- S.D.) in leukocytes compared to skin (7792+/-596 bp, P<0.01) and synovial tissue (7910+/-420 bp, P<0.001). In general, we have observed an inverse relationship between donor age and TRF length which becomes significant in leukocytes (P=0.04, R(2)=0.49) and skin specimens (P=0.006, R(2)=0.81). Interestingly, linear correlations (P values between 0.017 and 0.038, R(2) values between 0.54 and 0.79) were also obtained on comparison of telomere length in each pair of two different tissues from the same donor without taking donor age into account. This suggests that genetic determination of the regulation of telomere length is tissue-independent. Furthermore, our results indicate that TRF measurement in easily accessible tissues such as blood could serve as a surrogate parameter for the relative telomere length in other tissues.

Real-time monitoring of the recurrent laryngeal nerve: An observational clinical trial

BACKGROUNDnA variety of tools has been developed to identify nerve structures and to lower the risk of nerval injury during thyroid surgery. These tools are usually based on intermittent electrophysiological tracing of the nerves, but its use is still associated with permanent recurrent laryngeal nerve (RLN) injury. We are now presenting the results of the implementation of a novel real-time nerve monitoring system, based on a new vagal nerve cuff electrode.nnnMETHODSnNineteen consecutive patients scheduled for thyroid surgery (17 with benign, 2 with malignant disease), were enrolled in this observational trial. The flexible cuff electrode was implanted during each operation and atraumatically surrounded the vagal nerve. The evoked potentials were sensed by standard thyroid electrodes. Electrical stimulation and recording were achieved through a multichannel electromyography (EMG) system. The signal analysis was performed in real-time by specially designed software.nnnRESULTSnThe cuff electrode did not cause any complications during or after the surgery. In all patients, stable and reproducible signals were easily evoked. The mean time required to place the electrode was 6.5 min. The mean overall vagal nerve stimulation time was 65 min. No permanent RLN lesions were detected in any patient. One patient with a postoperative bleeding from a strap muscle vein required a wound revision, which was performed without nerve monitoring. This patient experienced a temporary partial impairment of the left vocal cord. No hypoparathyroidism was observed in any patient postoperatively.nnnCONCLUSIONSnThe presented technique of real-time continuous RLN monitoring by stimulation of the vagal nerve is feasible, safe, reproducible, and easy to perform. In addition, this new system is compatible with existing equipment and can be used as an add-on with conventional nerve monitoring devices during thyroid surgery.

Cyclooxygenase-2 Expression in Human Colorectal Cancer Is Unrelated to Overall Patient Survival

Purpose: Cyclooxygenase-2 (COX-2) expression in human colorectal cancer and adenoma tissue seems to be higher than in normal mucosa. However, data about the relation between COX-2 expression and patient survival are inconclusive as yet. Therefore, we studied COX-2 expression in surgery tissue and survival time in a cohort of 747 colorectal cancer patients. Experimental Design: Surgical specimens of primary colorectal cancer from 747 individuals were immunostained for COX-2 and evaluated under a transmission light microscope. COX-2 expression was scored according to intensity and extent of staining, resulting in the COX-2 immunoreactivity score (IRS-COX2). All possible cutoff points for IRS-COX2 were analyzed for a relation between COX-2 expression and patient survival. Results: Both univariable and multivariable analysis have shown that the COX-2 expression in human tumor epithelial cells was unrelated to overall patient survival and to disease-free survival, irrespectively of the cutoff point for IRS-COX2. The survival rates for 1, 3, 5, and 10 years were 81.0%, 66.8%, 60.2%, and 49.8% (median: 117.3 months; 95% confidence interval, 102.3-132.0), respectively. In the multivariable analysis, only node and metastasis were significantly related to overall patient survival. Similar results were obtained when stage IV and rectal cancer patients were excluded from the analysis. Conclusions: COX-2 expression in tumor epithelial cells does not seem to be related to survival of colorectal cancer patients. Besides COX-2, there are several targets, such as the peroxisome proliferator–activated receptors, that are involved in carcinogenesis and may be modulated by nonsteroidal anti-inflammatory drugs. Further studies are needed to determine their prognostic relevance.

A new system for continuous recurrent laryngeal nerve monitoring

Existing nerve monitoring devices in thyroid surgery are ‐ except for one ‐ mainly intermittently working nerve identification tools. We present a new vagal electrode which allows true continuous monitoring of the recurrent laryngeal nerve (RLN). The electrode was designed as a tripolar hybrid cuff electrode consisting of polyimide, gold and platinum layers embedded in a flexible silicon cuff which can be opened at the long side for introducing the nerve. It is fully implantable and atraumatic. The evoked potentials are sensed by standard thyroid electrodes. Real‐time signal analysis and audio feedback are achieved by specially designed software. Homogeneous and stable signals were recorded throughout the operations. Thus real‐time computer‐based signal analysis was possible. Evoked potentials reached 300–900u2005mV. Mean time to place the cuff electrode was 5.5u2005min. The nerve was stimulated a mean of 63u2005min (range 55–99u2005min). No RLN lesions were detected postoperatively. The new vagal electrode was easy to handle and led to stable and reproducible signals. The stimulation current could be kept extremely low due to the special geometry of the electrode. It offers the possibility for uninterrupted, continuous laryngeal nerve monitoring in thyroid surgery. In an ongoing clinical trial its compatibility as an add‐on for existing nerve monitoring devices is being tested.

Impact of continuous intraoperative neuromonitoring on autonomic nervous system during thyroid surgery

Continuous intraoperative neuromonitoring (CIONM) via vagal nerve stimulation (VNS) is a new option for recurrent laryngeal nerve (RLN) protection during thyroid surgery. The aim of this study was to evaluate the safety of VNS for CIONM and to assess its effects on the autonomic nervous system (ANS) through analyzing heart rate variability (HRV).

Psychotropic drug use, falls and hip fracture in the elderly

The use of benzodiazepines (BZD) or other psychotropic agents is an established risk factor for falls and hip fractures. The evidence supporting this association has been based solely on history and/or prescription data. In a case-control study we monitored the intake of BZD, tricyclic antidepressants (TCA) and barbiturates in patients with hip fracture by serum analysis, and compared this measurement with drug history and prescription records. The serum was BZD positive in 41% of 82 community-dwelling patients; an equivalent by history and/or prescription records, however, was detected in only 18% (p>0.0001). In contrast, in 82 age- and gender-matched community-dwelling control patients, there was only a minor discrepancy (3%) in BZD use between anamnestic (N=19) and analytical (N=21) data. In 23 patients admitted from nursing homes, a similar trend was visible (39% serum positive for BZD vs 26% by drug history). Barbiturate use (N=2) could be neglected, and TCA intake was minor (N=7); in each case both assessments were in accordance. In conclusion, in patients with hip fracture, BZD use is substantially more frequent than reported and previously assumed, pointing to an underestimated risk factor for this injury.

Safety analysis of vagal nerve stimulation for continuous nerve monitoring during thyroid surgery.

Intraoperative neuromonitoring (IONM) facilitates recurrent laryngeal nerve (RLN) identification, but various studies affirm virtually unchanged postoperative RLN palsy rates. Several authors meanwhile suggest continuous intraoperative neuromonitoring (CIONM) via vagal nerve stimulation (VNS) to improve RLN protection. However, knowledge of side effects of electrical VNS derives mainly from its therapeutic applications in the fields of neurology and psychiatry. The presented study was conducted to further evaluate the safety of CIONM and identify possible VNS related side effects.

Efficacy and morbidity of surgical therapy in late-stage encapsulating peritoneal sclerosis

BACKGROUNDnEncapsulating peritoneal sclerosis (EPS) is a rare but devastating complication of peritoneal dialysis composed of chronic abdominal pain, chronic ileus, and severe malnutrition. Operative therapy for EPS is a complex procedure, including perionectomy and enterolysis (PEEL). In contrast to simple adhesiolysis, PEEL comprises a restitution of intestinal passage and prevention of recurrent disease by decapsulation and partial deserosation.nnnMETHODSnWe reviewed the treatment of patients with EPS at our referral center regarding perioperative morbidity, mortality, and long-term outcome. Only patients who underwent PEEL were included. Preoperative general status was ascertained by APACHE-II score and body mass index. Postoperative morbidity was stratified into minor and major complications.nnnRESULTSnBetween the years 2003 and 2010, 26 of 45 patients with late-stage EPS underwent PEEL. Median age was 54 years, APACHE-II score was 15, and body mass index was 21 kg/m². To achieve intestinal function, 9 bowel resections with immediate anastomoses were necessary. Eleven patients (37%) received a complete parietal peritonectomy. Overall morbidity was 44%, with minor complications in 2 patients (7%) and major complications in 11 patients (31%). Three patients (10%) died within the first year after operative treatment.nnnCONCLUSIONnPEEL is a treatment option that can be performed with low mortality and acceptable morbidity. It is a precondition that these patients are treated in specialized referral centers.

Histological criteria for encapsulating peritoneal sclerosis - a standardized approach.

Background The two most relevant pathologies of long-term peritoneal dialysis (PD) are simple sclerosis and encapsulating peritoneal sclerosis (EPS). The histological differentiation of those two entities is difficult. The Aim of the study was to establish a method to standardize and facilitate the differentiation between simple sclerosis and EPS Methods We investigated 58 peritoneal biopsies - 31 EPS patients and 27 PD patients. Two blinded investigators analyzed 20 histological characteristics in EPS and PD patients. Results The following findings were significantly more common in EPS than in patients on PD without EPS: fibroblast like cells (FLC) (p<0.0001), mesothelial denudation (p<0.0001), decreased cellularity (pu200a=u200a0.008), fibrin deposits (p<0.03), Fe deposits (pu200a=u200a0.05), podoplanin vascular (p<0.0001), podoplanin avascular (p<0.0001). Using all predictor variables we trained the classification method Random Forest to categorize future cases. Podoplanin vascular and avascular were taken together (p<0.0001), FLC (p<0.0001), mesothelial denudation (pu200a=u200a0.0005), calcification (pu200a=u200a0.0026), acellular areas (pu200a=u200a0.0094), and fibrin deposits (pu200a=u200a0.0336) showed up as significantly important predictor variables. Estimated misclassification error rate when classifying new cases turned out to be 14%. Conclusion The introduced statistical method allows discriminating between simple sclerosis and EPS. The misclassification error will likely improve with every new case added to the database.

Natural Orifice Transluminal Endoscopic Surgery (NOTES) for colon resections—analysis of the first 139 patients of the German NOTES Registry (GNR)

BackgroundThe German NOTES registry (GNR) is the largest published database for natural orifice transluminal endoscopic surgery (NOTES) worldwide. Although transvaginal cholecystectomy is the most frequent procedure in the GNR, the number of colorectal resections is increasing. The objective of this study was to analyze the first 139 colonic procedures of the GNR.MethodsAll colonic procedures from the GNR were analyzed regarding patient- and therapy-related parameters. A multivariate analysis was conducted for transvaginal sigmoid resections regarding procedural time, hospital stay, conversion rate, and rate of complications.ResultsFrom October 2008 to January 2013, 139 colon NOTES procedures (12 male, 127 female) were registered. Main diagnoses were sigmoid diverticulitis (85.6xa0%), colon carcinoma (9.4xa0%), and ulcerative colitis (3.6xa0%). Sigmoid resections (87.1xa0%), proctocolectomies (3.6xa0%), right-sided resections (2.9xa0%), left-sided resections (3.6xa0%), segmental resections (2.2xa0%), and 1 ileocecal resection (0.7xa0%) were performed. All procedures were conducted in transvaginal (87.8xa0%) or transrectal (12.2xa0%) hybrid technique, with a median of 3 percutaneous trocars. Conversions to laparoscopic technique were necessary in 3.6xa0% (none to conventional technique). Intraoperative complications were recorded in 2.9xa0% and postoperative complications in 12.2xa0%. The institutional case number in transvaginal sigmoid resections correlated negatively with procedural time (pu2009=u20090.041) and the number of percutaneous trocars (pu2009=u20090.002).ConclusionThe analysis of the first 139 colon NOTES operations of the GNR shows the feasibility of colon operations in hybrid technique, especially for transvaginal sigmoid resection as the most frequent procedure.