Entropic characterization of the coil-stretch transition of polymers in random flows.

Polymer molecules in a flow undergo a coil-stretch phase transition on an increase of the velocity gradients. Model-independent identification and characterization of the transition in a random flow has been lacking so far. Here we suggest to use the entropy of the extension statistics as a proper measure due to strong fluctuations around the transition. We measure experimentally the entropy as a function of the local Weisenberg number and show that it has a maximum, which identifies and quantifies the transition. We compare the new approach with the traditional one based on the theory using either linear Oldroyd-B or nonlinear finite extensible nonlinear elastic polymer models.

Heat and moisture exchanger use reduces in-hospital complications following total laryngectomy: a case-control study.

BACKGROUND: Total laryngectomy (TL) is an appropriate oncologic operation for many patients with laryngeal cancer delivering excellent oncologic outcomes, however it remains beset with significant functional consequences. Following TL, the upper and lower airways are permanently disconnected, which causes unfiltered, cold air with reduced humidity to enter the tracheobronchial tree, resulting in mucus overproduction and an increase in the viscosity of the mucus. In response to this, Heat and moisture exchangers were developed to compensate for the lost functions of the upper respiratory tract and their effect on the patients' respiratory performance in addition to their quality of life. METHODS: The case records of 48 patients undergoing total laryngectomy were reviewed and data concerning demographics, surgical details, post-operative care requirements and adverse events was retrieved. Post hoc analysis of the case patients was undertaken to identify any benefit of using a heat and moisture exchanger (HME) system with particular reference to post-operative respiratory outcomes. RESULTS: There was no significant difference between case and control subjects based on demographics, extent of surgery or need for flap repair. 16 patients had used a HME and 32 patients had used external humidification (EH). Of those experiencing mucous plugging, only 3/24 (12.5 %) had used a HME system, in contrast to 21/24 (87.5 %) who used EH (Chi square = 9.375, p = 0.002). The odds ratio of having an adverse event if not using HME was 8.27 (CI = 1.94 - 35.71). Use of HME also significantly reduced the number of days requiring physiotherapy (1.75 days vs. 3.20 days, p = 0.034). CONCLUSION: Use of an HME system can reduce in-hospital complications, in particular episodes of mucus plugging, and post-operative care requirements. Furthermore, there is a cost benefit to using HME systems that warrants more widespread introduction of these devices in head and neck surgery centers.

[The surgical treatment of varicocele in children and adolescents in the outpatient setting].

The first group included 45 patients with varicocele stage I--II; the second group included 20 patients with varicocele stage III. The ambulatory treatment complex permitted the inmprovement of of ultrasound indexes in scrotal veins in 29 (64%) patients of the 1st group, whereas nobody of the 2nd group showed any isignificant improvement. The proper use of the worked out complex allows the pathogenetic and correct treatment of varicocele in adolescents.

[Surgical therapy for esophageal carcinoma: a prospective 20-year analysis]. / Chirurgische Therapie des Osophaguskarzinoms: Eine prospektive 20-Jahres-Analyse.

BACKGROUND: The aim of our study was the analysis of long-term developments in the surgical therapy for esophageal carcinoma at our hospital over a period of 20 years with a differentiated view on the two predominant histological tumour types. PATIENTS AND METHODS: Between September 1985 and September 2005, esophageal resections were performed in 470 patients at our clinic on account of a malignant tumour of the esophagus. The abdomino-thoracic resection with abdominal and extended mediastinal lymph node dissection as well as intrathoracic anastomosis was the standard treatment in the case of squamous cell carcinoma, whereas in adenocarcinoma a transhiatal resection with abdominal and dorsal mediastinal lymphadenectomy and cervical esophagogastrostomy was carried out. For analysis of the development, the study period of 20 years was divided into two intervals: interval 1 from 9 / 1985 to 9 / 1995, and interval 2 from 10 / 1995 to 9 / 2005. RESULTS: Both tumour entities displayed in the last interval (10 / 1995 to 9 / 2005) significantly earlier tumour stages. A proportionally identical amount of transhiatal resections for squamous cell carcinoma was found in both intervals, whereas the transhiatal procedures for adenocarcinoma increased in the last decade (3.6 % in the period between 9 / 1985 and 9 / 1995, as compared with 23.6 % between 10 / 1995 and 9 / 2005) (p < 0.05). While the overall prognosis for squamous cell carcinoma did not significantly differ in the two decades (p = 0.2040), patients with adenocarcinoma were found to have a significantly improved long-term survival (log-rank test: p = 0.0365) in the second decade. The prognosis for adenocarcinoma, therefore, could be improved in the course of time with a 3-year survival rate of finally 40 % (as compared with 17.5 % in the first decade), and a 5-year survival rate of 25 % (as compared with 15 %). CONCLUSION: Surgical therapy for esophageal carcinoma has undergone distinct changes over the past 20 years. These are mainly due to epidemiological and diagnostic aspects, an improved selection of patients, whereby the operative procedure is adapted to the tumour stage and the operative risk for the patient. Especially with adenocarcinoma of the esophagus, these changes have led to a significantly more favourable long-term prognosis.

[Childhood achalasia: a separate entity?]. / Achalasie im Kindesalter: Eine separate Entität?

BACKGROUND: Achalasia in childhood is rare, also the etiology and the pathogenesis of the early onset ort he disease is practically unknown. Little is known about the neuropathological changes in structure of the esophageal wall in non-hereditary, sporadic achalasia in children and ist differentiation to that in adults. The aim of our study was to examine the morphological properties or high-pressure zone of the lower esophageal sphincter in children who had undergone a Heller myotomy because of achalasia as well as to compare them with the pathological findings in adults. METHODS: Muscle biopsies of the smooth musculature, a 20 x 10 mm long segment of the myenteric of the distal esophagus (lower boundary of the esophageal incision of the myotomy), were taken for histopathological and immunohistochemical studies. RESULTS: A conspicuous histomorphological finding was a marked reduction of the myenteric ganglion through to complete aganglionosis of the high-pressure zone of the lower esophageal sphincter. In contrast to achalasia in adults, neural inflammation was found only rarely. A pronounced fibrosis of the smooth muscle layers was found in all patients whereas muscular hypertrophy or visceral myopathy was not present. The interstitial Cajal cells were reduced, similar to those in adults. CONCLUSIONS: The variability of the clinical and pathological properties in cases of childhood achalasia are indicative of a complex pattern of varying etiologies and a comparison with the disease in adults does not, in principle, allow the assumption of a separate clinical entity. The present findings are compatible with the histopathological results of hereditary achalasia in children as described for Allgrove's syndrome.

Developments in esophageal surgery for adenocarcinoma: a comparison of two decades.

BACKGROUND: The objective of this study was to examine outcomes in patients undergoing esophageal resection for adenocarcinoma at our institution during a 20-year period and, in particular, to address temporal trends in long-term survival. METHODS: Out of 470 patients who underwent esophagectomy for malignancy between September 1985 and September 2005, a total number of 175 patients presented with esophageal adenocarcinoma. Patients enrolled in this study included AEG (adenocarcinoma of the esophagogastric junction) type I tumors only. Time trends were studied comparing two decades, 9/1985 to 9/1995 (DI) and 10/1995 to 9/2005 (DII). RESULTS: The overall survival was significantly more favourable in patients undergoing esophageal resection for adenocarcinoma in the recent time period (DII, 10/1995 to 9/2005) as compared to the early time period (DI, 9/1985 to 9/1995) (log rank test: p = 0.0329). Significant differences in the recent decade were seen based on lower ASA-classifications, earlier tumor stages, and the operative procedure with a higher frequency of transhiatal resections (p < 0.05). 30-day mortality improved from 8.3% to 3.1% during the 20-year time-interval, thus without statistical significance. CONCLUSION: Based on our experience, overall survival is improving over time for adenocarcinoma of the esophagus. Factors that may play an important role in this trend include early diagnosis and improved patient selection through better preoperative staging, improved surgical technique with a tailored approach carefully evaluated by physiologic patient status, comorbidity and tumor extent.

[Indicators of quality in surgical treatment of rectal carcinoma]. / Qualitätsindikatoren der chirurgischen Therapie des Rektumkarzinoms Ergebnisse einer prospektiven Studie.

INTRODUCTION: For the assessment of surgical therapy for rectal cancer, perioperative and oncological as well as aspects of quality of life have to be taken into consideration. The objective of the present analysis was to identify indicators allowing assessment of the quality of the surgical intervention. PATIENTS AND METHODS: Between March 1997 and August 1998,50 patients with adenocarcinoma of the rectum were operated on by five surgeons according to the concept of total or partial mesorectal excision. In 4 patients an anterior, in 35 a low anterior resection, and in 11 an abdominoperineal resection was performed. There was a stage IV (UICC) present in 9 cases, and in 18 patients the tumor extension was restricted to the wall. The demographic and perioperative data as well as the results of the follow-up examination were registered prospectively. The median follow-up period amounted to 44 months (5-57). RESULTS: Intraoperative parameters showed no differences concerning the individual operating surgeons. General complications arose in 9 (50%) and surgical complications in 34 (68%) patients. Anastomotic leakage (5/39), perineal wound infection, and bladder dysfunction (requiring catheterization for bladder emptying) occurred as frequent complications and there were differences with regard to the surgeon. The rate of local recurrence was different and was between 0% and 75% for the individual surgeons. CONCLUSIONS: For the assessment of surgery for rectal carcinoma, only a few parameters are necessary. As indicators of quality after rectal resection, the rate of anastomotic leakage should be registered; after abdominoperineal resection, the rate of perineal wound infection, the ratio of postoperative bladder dysfunction, and the locoregional rate of recurrence should be registered.

[Long-term outcome of myotomy and semi-fundoplication in achalasia]. / Langzeitergebnisse nach Myotomie und Semifundoplicatio bei Achalasie.

The basic principle behind the treatment of achalasia consists of alleviating swallowing disorders by reducing resistance in the lower esophageal sphincter without inducing gastroesophageal reflux. Only a few studies are available on long-term results after operative treatment. Fifty-one patients were studied with regard to long-term results after open transabdominal extramucosal myotomy of the distal esophagus along with partial anterior fundoplication (Dor procedure). Clinical data were collected by standardized interviews, and symptoms were assigned a score ranging from 0 to 3 according to severity and frequency. The pre- and postoperative symptoms were comparable in 50 patients. The median duration of follow-up was 88 months (range: 12-160 months). Operative time was a median of 80 min. Two esophageal mucosal tears were recognized intraoperatively and promptly repaired. Postoperative morbidity occurred in two patients (3.9%). Very good or good long-term results after surgical therapy were achieved in 49 patients (96.1%). Forty-seven patients (92.2%) have no or rare dysphagia. The frequency of regurgitation as well as chest pain was also significantly reduced after surgery. Forty-nine patients (96.1%) either maintained or gained weight. Preoperative duration of symptoms, follow-up, age, and gender had no influence on the results (p > 0.05). Two patients (3.9%) mentioned occasional heartburn. Five patients (9.8%) took or still take proton pump inhibitors postoperatively. Severe stage IV symptoms due to peptic stricture and dolichomegaesophagus required reoperation in one patient (2%). The results show that myotomy and the antireflux procedure (semifundoplication) lead to long-term relief of dysphagia without inducing reflux at a low operative risk. Since long-term results are as yet not available for minimally invasive surgery, it remains to be seen if this operative technique will become the primary surgical procedure for this disease.

[Esophageal resection in treatment of achalasia. 4 case reports and review of the literature]. / Osophagusresektion zur Behandlung der Achalasie. Vier Fallberichte und Ubersicht über die Literatur.

In the time period between 1985 and June 2001, four of 81 patients diagnosed with achalasia were surgically treated by means of transhiatal esophageal resection. Replacement with stomach and cervical anastomosis was performed in three patients aged 8, 19, and 27 years, respectively, after initial myotomy. In one case, the esophagus resection was the primary surgical measure and the colon was used as the replacement. The preoperative symptoms of the four patients showed improvement 51, 34, 15, and 8 months after the operation, respectively. Dysphagia and regurgitation no longer occurred. One patient died 4.5 years after esophageal resection due to ulcerous bleeding of the distal redundant colon interposition. In accordance with other studies investigating serious swallowing disorders, it could be shown that transhiatal resection with esophagus-replacement through stomach pull-up can lead to symptom-relief as well as an improvement in the quality of living.

Perception of temperature elevation in human seasonal heat adaptation.

Higher values of the exponent power function of the perception of temperature elevation (1.66, 1.32, and 1.50) in the summer than in the winter (1.40, 1.08, and 0.84) were established in seasonal investigations in people at room air temperatures of 20, 28, and 40 degrees C. Consequently, following adaptation to the seasonal high temperature a person can feel a smaller temperature increment than in the winter. This suggests a reorganization in the functional activity of the temperature analyzer under the prolonged influence of seasonal high temperature.

[The action of high temperature on beta-adrenoreceptor activity and catecholamine synthesis]. / Deistvie vysokoi temperatury na aktivnost' beta-adrenoretseptorov i sintez katekholaminov.

Hyperthermia and overheating of the rat isolated organs induce significant changes of the binding of receptors' specific blockers and catecholamine synthesis. One of the main mechanisms of the organism response to the temperature actions involves a local rearrangement in intensity of different stages of the adrenergic process. Possible significance of these changes in the hypothalamus for synchronisation of the organism's response to extreme temperature effects, is discussed.

[The perception of a temperature rise in human seasonal heat adaptation]. / Vospriiatie povysheniia temperatury pri sezonnoi teplovoi adaptatsii cheloveka.

At ambient temperatures 20 degrees, 28 degrees and 40 degrees C the exponent of the power function of warmth perception was 1.40, 1.08 and 0.84 in winter and 1.66, 1.32 and 1.50 in summer, resp. Seasonal heat adaptation seems to lead to an increase of the warmth perception due to functional modification of temperature analyser activity.