A dual-channel gas chromatography method for the quantitation of low and high concentrations of NF3 and CF4 to study membrane separation of the two compounds.

A dual-channel gas chromatographic method is described in this paper that can be conveniently used for quantitation of NF3/CF4 mixtures with a thermal conductivity detector (TCD) on one channel for the quantitation of high-concentrations, and a pulsed discharge helium ionization detector (PDHID) on a second channel for the quantitation of low concentrations. It is shown that adequate separation is achieved on both channels with this dual single-column setup in which column switching as used for NF3/CF4 analysis in industrial chromatographic methods are not required, thus yielding an effective analysis method for laboratory-scale investigations. In addition, the use of packed columns with purified divinylbenzene-styrene co-polymers as the sole stationary phase yields satisfactory resolution between NF3 and CF4 at isothermal conditions of 30°C, with elution times of less than 8min on the TCD channel and less than 4min on the PDHID channel. Consequently, this method allows for reliable, straight-forward quantitation of NF3/CF4 mixtures, which is necessary when studying the commercially important problem of NF3 and CF4 separation by different methods. Therefore, the applicability of the method to studying membrane separation of NF3 and CF4 is briefly discussed and illustrated, for which the dual-channel setup is especially beneficial.

[Process optimization in ENT: clinical pathways and central induction area]. / Prozessoptimierung in der HNO : Behandlungspfade und zentrale Einleitung.

INTRODUCTION: Owing to the rising costs in the health care system, it is now important to optimize processes through standardization and process consolidation. A lack of process consolidation in this area of operation or overly long durations of stay of patients in the hospital can lead to increased costs for the ENT department. The aim of this study was to examine whether process optimization could be achieved through close interdisciplinary networking with clinical pathways and central induction (CI). MATERIAL AND METHODOLOGY: In the 1-year periods before and after the implementation of CI, turnover times in the ENT department were retrospectively examined and 2,433 patients from the entire operative ENT spectrum were included. The average durations of stay before and after the implementation of the "septoplasty" pathway were additionally evaluated. RESULTS: ENT turnover times were significantly reduced after the introduction of CI. In comparison to the conventional anaesthesia process, the turnover times using CI were on average 10 min shorter. Furthermore, since the introduction of pathways, the duration of stay for ENT patients could be significantly reduced while simultaneously maintaining the quality of care. This process was statistically evaluated using septoplasty in nasal surgery as a typical example and the duration of stay was reduced from 5.85 days to 4.32 (a reduction of 26%) or 3.55 days (a reduction of 34%). CONCLUSIONS: The combination of CI and pathways is a suitable means to increase the clinical and economic effectiveness even when the new case-based flat-rate system is taken into consideration.

[Time delay in beginning first OR positions in the morning]. / Zeitverzögerungen beim morgendlichen OP-Beginn.

Delayed starts of operation room (OR) processes in the morning lead to suboptimal use of expensive OR personnel and resources. Therefore, the anaesthesiologist has to take care that anaesthesia preparation and induction are finished in time and the patients are ready for the surgical intervention according to the OR time schedule. However, if the anaesthesiologist starts too early, preincision waiting periods occur. The literature provides little data regarding the complex interaction of anaesthesia process times and delayed operation starts in the morning. In this prospective study 710 first operation positions in the morning were analyzed with respect to the incidence of and reasons for delayed finishing of anaesthesia induction and investigated the interaction of early and late finishing of anaesthesia induction. In 27.5% of anaesthesia inductions the preset time schedule was not reached and the average delay was 19.3+/-17.2 min. The main anaesthesia-dependent reasons for delays were complex anaesthesia inductions with difficult line placement. Also organizational difficulties such as changes in the OR case schedule and delayed patient transport were of major importance. The results of a simulation model showed that in 100% of the cases finishing anaesthesia induction in time would only be feasible if anaesthesia processes started much earlier. However, this would lead to a sharp increase in preincision waiting time with the patient being under anaesthesia but surgeons not ready to start, therefore having only a minor effect on surgical waiting time. Subsequently, on-time anaesthesia induction in all cases is not a reasonable target in OR management.

[Central induction area. Reduction of non-operative time without additional costs]. / Zentrale Einleitung. Personalneutrale Reduktion der Wechselzeiten.

BACKGROUND: Induction areas (IA) can lead to more efficient operating sessions through shortening the changeover time between patients. To date IAs have always required additional staff members, whose cost was only partly covered by improvements in productivity. The objective of this project was to demonstrate that a reduction in non-operative time through a newly introduced induction area can be achieved without a need for extra personnel. METHODS: Non-operative time in 5,963 ENT, orthopedic and cardiac surgical patients from 8 operating theatres were studied for 1 year before and 1 year after the introduction of an induction area. The non-operative time was defined as the time between the end of surgical procedures in one operation and the start of surgical procedures in the next, within regular working hours. Through reallocation of anesthetic nursing and medical staff it was possible to introduce the induction area without increasing staff numbers. RESULTS: Non-operative time was significantly reduced from 20 min (range 10-30 min) to 14 min (5-25 min). Subgroup analysis showed significant reductions in all specialities: from 10 min (2.5-20 min) to 5 min (0-20 min) in 1,240 cardiac surgical patients, 25 min (20-35 min) to 15 min (5-25 min) in 2,433 ENT patients and 20 min (10-30 min) to 10 min (0-20 min) in 2,290 orthopedic patients. There were no critical incidents attributable to patient handover. DISCUSSION AND CONCLUSIONS: An induction area can be established and can reduce non-operative time and improve operation theatre throughput without the need for extra personnel. The efficiency of these measures will be increased when the relevant surgical organizational measures are taken to adjust to the faster anesthesiology workflow. The induction area does not lead to a higher rate of critical incidents. To what extent the induction area can be used for structured training of doctors and nurses, remains to be investigated.

Calcium alginate entrapment of the yeast Rhodosporidium toruloides for the kinetic resolution of 1,2-epoxyoctane.

Resting cells of the yeast Rhodosporidium toruloides (UOFS Y-0471) were immobilised in calcium alginate beads for the enantioselective kinetic resolution of racemic-1,2-epoxyoctane. The initial activity exhibited by immobilised cells was almost 50% lower than that of the free counterpart but was extremely stable when compared to the free cells. The concentration of the immobilised biomass had no effect on apparent enzyme activity but did lead to a decrease in single cell activity. An increase in both the alginate and CaCl2 concentrations used for bead preparation led to a decrease in enzyme stability. An increase in the alginate concentration led to an increase in bead diameter. The stoichiometric equation for cross-linking of alginate was only obeyed when CaCl2 concentrations higher than 0.4 M were utilised for bead preparation.

Biocatalysis of nitro substituted styrene oxides by non-conventional yeasts.

Yeast strains (410) from more than 45 different genera were screened for the enantioselective hydrolysis of nitro substituted styrene oxides. These strains included 262 yeasts with known epoxides hydrolase activity for various other epoxides. Epoxide hydrolase activity for p-nitrostyrene oxide (pNSO) (177 strains) and m-nitrostyrene oxide (mNSO) (148 strains) was widespread in the yeasts, while activity for o-nitrostyrene oxide (oNSO) was less ubiquitous (22 strains). The strains that displayed enantioselectivity in the hydrolysis of one or more of the nitro substituted styrene oxides (35 strains) were also screened against styrene oxide (SO). Rhodosporidium toruloides UOFS Y-0471 displayed the highest enantioselectivity for pNSO (ee 55%, yield 35%) while Rhodotorula glutinis UOFS Y-0653 displayed the highest enantioselectivity for mNSO (ee > 98%, yield 29%), oNSO (ee 39%, yield 19%) and SO (ee > 98%, yield 19%). (R)-Styrene oxide was preferentially hydrolysed to the corresponding (R)-diol with retention of configuration at the stereogenic centre. In the case of the nitro substituted styrene oxides the absolute configurations of the remaining epoxides and the formed diols were not established.

Inhibition of clastogenicity of benzo[a]pyrene and of its trans-7,8-dihydrodiol in mice in vivo by fruits, vegetables, and flavonoids.

In the in vivo mouse bone marrow micronucleus assay, homogenates of spinach, artichoke, peaches, and blue grapes as well as commercial concentrates of these vegetables and fruits reduced induction of micronuclei by benzo[a]pyrene (BaP) by 43-50%. Concentrates of strawberries (31% reduction) and of cauliflower (20% reduction) were less potent. Inhibition of genotoxicity by spinach and peaches was not caused by any delay in maturation of micronucleated erythrocytes as shown by experiments with sampling times of 24, 48, and 72 h after dosing of BaP. Pre-treatment of the mice with spinach 48, 24, and 12h before application of BaP resulted in a 44% reduction of micronuclei while peaches generated only a marginal effect. A post-treatment procedure administering spinach or peaches 6h after dosing of BaP did not indicate any protective effects. When trans-7,8-dihydroxy-7,8-dihydrobenzo[a]pyrene (BaP-7,8-OH) was applied for induction of micronuclei spinach and peaches reduced the number of micronuclei by 55 and 48%, respectively. Pre-treatment of mice with spinach 96, 72, and 60 h before sacrifice caused a decline of hepatic 7-ethoxyresorufin-O-dealkylase (EROD) and of 7-pentoxyresorufin-O-dealkylase (PROD) activities by factors of 2.2 and 1.4, respectively. However, statistical significance was not reached. On the other hand, peaches had no influence on hepatic EROD or PROD activities. The flavonoids quercetin and its glucoside isoquercitrin, administered orally in doses of 0.03 mmol/kg body weight simultaneously with intraperitoneally given BaP, reduced the number of micronuclei in polychromatic erythrocytes of the bone marrow of mice by 73 and 33%. Ten-fold higher concentrations, however, reversed the effects with a particular strong increase observed with isoquercitrin (+109%; quercetin: +16%).

The influence of beta-cyclodextrin on the solubility of chlorthalidone and its enantiomers.

The solubility of chlorthalidone in 16 solvent systems was determined in the absence and presence of different amounts of beta-cyclodextrin (beta-CD). Chlorthalidone (CT) was shown to be more soluble in hydrophilic organic solvents, with the highest solubility in ethylacetate (EtOAc) saturated with water. The solubility of CT in water, butanol, octanol, and dichloromethane (DCM) was enhanced by the addition of beta-cyclodextrin. The enantioselective partitioning of CT between water and EtOAc, DCM, butan-1-ol, butan-2-ol, and octan-1-ol was determined in the presence of beta-CD at pH 5, 7, and 9. According to the results, both the solubility and partitioning properties of CT are affected by beta-CD in aqueous solution. It was also shown that the solubility of the individual enantiomers differs in the presence of beta-CD.

[High malignant B-cell non-Hodgkin lymphoma of the heart: intravital diagnosis by transesophageal echocardiography controlled biopsy]. / Hochmalignes B-Zell-Non-Hodgkin-Lymphom des Herzens: intravitale Diagnose durch transösophageale Echokardiographie-gesteuerte Biopsie.

We report about a 66-year old patient with Non-Q-wave infarction in coronary artery two-vessel disease. During an echo- and transesophageal multiplane echocardiography preoperatively before a coronary artery bypass surgery a right atrium septal tumor of unknown form was discovered. The computerized axial tomography (CAT) and nuclear magnetic resonance (NMR) scans did not demonstrate extracardiac pathologic findings. A transesophageal echocardiography-guided biopsy of the right atrial septum over the vena femoralis and the right atrium enabled intra vitam a very early diagnosis of high malignant B-cell Non-Hodgkin-lymphoma without the need for thoracotomy. The diagnosis was confirmed histopathologically and immunohistochemically and early treatment with cytostatic therapy could begin. To our knowledge the transesophageal echocardiography-guided biopsy has never been described in the worldwide literature.

[Combined lytic and heart surgical therapy of in open foramen ovale incarcerated giant thrombus with pulmonary and cerebral embolization]. / Kombinierte lytische und herzchirurgische Therapie eines im offenen Foramen ovale inkarzerierten Riesenthrombus mit pulmonaler und zerebraler Embolisation.

A case of phlebothrombosis with recurrent pulmonary and cerebral embolism is presented which occurred in a 42 year old patient two weeks after treatment of a traumatic crural fracture despite of prophylaxis with low molecular heparin. By means of transthoracic echocardiography a large intracardiac thrombus was detected, entrapped in an patent foramen ovale (PFO) and prolapsing through both atrioventricular valves into both ventricles. This was found after systemic thrombolysis with rtPA had been performed because of fulminant pulmonary embolism. Subsequently the intracardiac thrombus was surgically removed and the PFO closed. The importance of an PFO for paradoxical embolism is discussed as well as the various therapeutical paths to treat an "embolus-in-transit" (cardiac surgery, thrombolytic therapy or anti-coagulation).

[Form fruste of long QT syndrome]. / Forme fruste eines langen QT-Syndroms.

The long QT syndrome (LQTS) is an inherited disorder associated with recurrent syncope and sudden death from ventricular arrhythmias. It is characterized by a prolonged QT interval on the ECG. A case is discussed in which a patient presented with recurrent syncopal episodes on exertion associated with a slightly prolonged QT interval. Family history revealed an increased incidence of sudden deaths in two generations. Some reports on similar patients suggest that there may be a forme fruste of the long QT syndrome. The additional diagnostic values of exercise stress test, Valsalva maneuver and genetic testing are evaluated. After analysis of the patient's and mother's ECGs the diagnosis of a forme fruste of LQTS is made. This case is presented to emphasize the importance of diagnosis of borderline cases of LQTS because of the high risk of sudden death for untreated patients.

[Prevention of thrombosis in surgery: low molecular weight heparin/standard heparin]. / Thromboseprophylaxe in der Chirurgie: Niedermolekulares Heparin/Standard-Heparin.

In a randomized study the efficiency of the low molecular weight heparin (LMWH) Fragmin and unfractionated heparin Calciparin in preventing thromboembolic disease was examined. Ninety patients undergoing a herniotomy participated in the study. The LMWH also showed good efficiency in a laboratory test of anti-factor Xa-activity. There were no complications.

[Comments on the induction of anesthesia in arthroscopy of the knee joint]. / Bemerkungen zur Narkoseführung bei der Kniegelenksarthroskopie.

Anaesthesia was applied to 1,036 patients for diagnostic or therapeutic knee-joint arthroscopy, between 1983 and 1985. Different indications for general and regional anaesthesia, setbacks of spinal anaesthesia, and advantages likely to result from combined use of peridural anaesthesia and peridural analgesia are discussed in some detail.

[Crohn's disease and pregnancy]. / Morbus Crohn und Schwangerschaft.

The interrelationship of pregnancy with Crohn's disease is as nebulous as aetiology and pathogenesis of this inflammatory bowel disease. In the years 1964-1981 we have operated upon 342 patients with Crohn's disease. 47 women suffering from this disease became pregnant. Whereas pregnancy appears to have little influence on the course of Crohn's disease, the incidence of miscarriages appears to rise with increasing activity and extent of bowel involvement. Only in case of exacerbation or complications is medical or even surgical therapy indicated in the course of pregnancy. Abortion does not appear to influence the course of Crohn's disease favourably.

[Morphometrical investigations on bowel interpositions after total gastrectomy (author's transl)]. / Morphometrische Untersuchungen an Darminterponaten nach totaler Gastrektomie.

Different types of interposition were performed on beagle dogs as stomach substitutes after total gastrectomy: (1) interposition of jejunal segment, (2) interposition of ileocecal region, (3) interposition of colon segment, and (4) jejunal segment according to Roux-en-Y configuration. The interpositions were evaluated morphometrically at defined sites 3 months after the operation. One of the most evident changes found in the interposed intestinal segment was strong hypertrophy of the circular muscular layer. In interposed colon segment the hypertrophy was less than in jejunal ones. The volume burden the newly formed stomach exposed to seems to be the pathogenetic factor responsible for this change. A change in villous morphology was shown with a reduction of the surface of the intestinal mucosa. Simultaneous enlargement of crypts presented a picture similar to the partial mucosal atrophy of the hyperregenerative type. In contrast, the mucosa of the colon interpositions was regular and showed no evident structural change. The alterations of the small intestinal mucosa seem to be induced mainly by differences in the intraluminal milieu. Besides the volume burden insufficient chyme digestion may be responsible for local malnutrition of the mucosa, which results in a morphological change. The hypertrophy of the muscular layer can be interpreted as adaptation to the reservoir function and the degeneration of small intestinal mucosa, as caused by trophic interference.

[Histological and enzyme histochemical studies of intestinal interposition after total gastrectomy]. / Histologische und enzymhistochemische Untersuchungen an Darminterponaten nach totaler Gastrektomie.

The formation of a stomach substitute with various intestinal interpolations (jejunum, ileocecum, colon) and the esophagojejunostomy by a Roux-anastomosis are carried through after total gastrectomy in animal experiments. The structural rebuilding proceedings in the intestinal interpolations were histologically and enzyme-histochemically examined after an experimental time of 3 months. A dilatation of the intestinal wall in connection with muscular wall hypertrophy appears in all operating method. In that way the reservoir function is guaranteed in the various stomach substitutes. The mucosa of the jejunal interpolation shows a hyperregeneratoric atrophy. A small enlargement of the surface originates in the colon interpolation from a villiferous conversion of the proximal parts of the crypts. The advance of the activity of the brush border enzymes in the ileocecum and the colon interpolation refers to an attempt of the mucosa on a change of the conditions of resorption. The essential pathogenetic factor of all rebuilding events appears in the intralumic environmental alteration in the intestinal interpolations.

[The clinical significance of the oxytocin challenge test (author's transl)]. / Klinische Bedeutung des Oxytocinbelastungstests.

In order to test the function of fetoplacental unit 398 oxytocin challenge tests were performed on 280 patients who had exceeded the calculated date of delivery or where factors of risk were involved. 8% of the tests performed showed a positive result, 1% was suspect and 91% were negative. The figure of 20% of false-positive test results was relatively high compared to only 1.6% in the case of false-negative test results. In cases where the calculated date of delivery has been exceeded, pregnant women who showed a negative test result are kept under observation by us as out-patients, whilst patients whose oxytocin challenge test was positive are kept under close observation in hospital.

[Surgical and medical treatment of Crohn's disease (author's transl)]. / Chirurgisch-internistische Therapie des Morbus Crohn

Regional enteritis does present therapeutical problems because of the unpredictable course of this disease. 162 patients were operated upon in the Surgical Department of the University of Mainz Medical School between 1964 and 1976. Medical and surgical treatment of these patients has been rather different due to the heterogenity of the patient group. Curative therapy of regional enteritis does not exist. Medical treatment is aimed at converting the active form of the disease into an inactive, 'burnt out' form. One therapeutic regimen widely used is the combination of salazosulfapyridin and corticosteroids, another regimen is the combination of azathioprine and prednisolone. Surgery is indicated when complications arise and after medical treatment has failed. The optimal approach is resection of the afflicted part of the intestine. Even after surgery prognosis is doubtful and depends upon the activity of the disease in each individual case.