Postoperative Resistenzentwicklung gegenüber Atracurium

Zusammenfassung Zwei F?lle einer postoperativ aufgetretenen Atracuriumresistenz werden vorgestellt. In beiden F?llen handelte es sich um Patienten, welche nach einem intrathorakalen Elektiveingriff eine septische Komplikation entwickelten. Kasuistik: Beim ersten Patienten (39 Jahre) entwickelte sich wenige Tage nach einer Pneumonektomie eine Bronchusfistel mit einer Superinfektion der Thoraxresth?hle. Zum Zeitpunkt des Revisionseingriffs war die Wirkung von Atracurium im Vergleich zur Prim?roperation deutlich ver?ndert: Die Anschlagzeit war verl?ngert (7 vs. 3,5 min), die Erholungszeit (DUR 10%) war verkürzt (14 vs. 28 min), und die Infusionsrate zur Aufrechterhaltung der Relaxation mu?te um ca. das 3fache gesteigert werden (14,3 vs. 5,0 μg/kg·min). Beim zweiten Patienten (56 Jahre) kam es im Anschlu? an eine Oberlappenresektion rechts zu einer Gangr?n des Mittellappens, welcher operativ entfernt werden mu?te. Die zur Intubation erforderliche Atracuriumdosis mu?te im Vergleich zur Prim?roperation deutlich gesteigert werden (70 vs. 40 mg), ohne da? hierdurch eine komplette neuromuskul?re Blockade zu erzielen war. Darüber hinaus war zur Ruhigstellung des Patienten eine wesentlich h?here Erhaltungsdosis als beim Ersteingriff erforderlich (11,8–16,5 vs. 5,5 μg/kg·min). Schlu?folgerung: Die Beispiele zeigen, da? sich innerhalb relativ kurzer Zeit eine Resistenz gegenüber Atracurium entwickeln kann, und wir nehmen an, da? diese Ver?nderungen durch die schweren, entzündlichen Komplikationen ausgel?st wurden.      

Iron absorption from bread in humans: inhibiting effects of cereal fiber, phytate and inositol phosphates with different numbers of phosphate groups.

Iron absorption was measured from five kinds of bread made from various types of flour and fermented in different ways in order to obtain a wide variation in the content of fiber, phytate (inositol hexaphosphate) and its degradation products, inorganic phosphate and inositol phosphates with fewer numbers of phosphate groups (inositol pentaphosphate through monophosphate). Each experiment had 9-10 subjects and, in each subject, iron absorption was measured from control rolls made from low extraction wheat flour and one kind of test roll using two different radioiron tracers: 55Fe and 59Fe. The inhibition of iron absorption was closely related to the content of phytate-phosphorous as determined using the AOAC method, and to the sum of the tri- through hexaphosphate groups as determined using the HPLC method. As an example, prolonged fermentation of whole-rye bread reduced total inositol phosphates to the same amount as in the control rolls and increased fractional iron absorption to the same high level, in spite of a fiber content five times as great. The results strongly suggest that the inhibitory effect of bran on iron absorption is due to its content of phytate and other inositol phosphates present after fermentation, rather than to its content of fiber or other constituents. Thus, effective fermentation will increase the bioavailability of iron in whole-meal bread.     

Five-year follow-up pulmonary function studies in patients with anti-trypsin deficient pulmonary emphysema]

Five-year follow-up study was carried out in pulmonary emphysematous patients with intermediate antitrypsin deficiency. The examinations showed no deterioration in the clinical state of the patients but in some parts of the controlled functional parameters a statistically significant worsening was found in this period of study.     

Early stress tests following an uncomplicated myocardial infarct: a comparison between symptom-limited and submaximal tests

To compare the diagnostic and prognostic usefulness of symptom-limited versus load-limited submaximal stress testing, 76 patients, during the first week post acute non-complicated myocardial infarction, were submitted to a symptom-limited Naughton-modified protocol stress test. At 2 METs, 3 METs and maximal effort levels, the tests were classified as positive or negative following the currently used criteria. After a mean follow-up of 15 months, the symptom-limited protocol showed the best sensitivity (95%), specificity (78%), positive (64%) and negative (98%) predictive value, and also the highest risk ratio (27.4) for prediction of subsequent coronary events (2p less than 0.01 vs 2 METs, 3 METs and 2D-Echocardiogram results). Forward stepped multiple correlation analysis indicated independent prognostic value for the results of the symptom-limited stress test (R2: .52 p less than 0.01) and for the location of the myocardial infarction (R2: .05 p less than 0.05) only. In addition, the discriminant prognostic power of the symptom-limited protocol was significant after the fourth month of follow-up (2p less than 0.05 vs submaximal tests and 2D-Echo). Therefore, we recommend the performance of a symptom-limited stress test during the first week post acute non-complicated myocardial infarction, provided that all coronary active medication has been withheld 24 hours before the test.     

The frequency, prognosis and significance of nerve injuries in total hip arthroplasty

Summary. Although the incidence of post-operative nerve palsy after total hip replacement is rare, it is an important complication for the patient. In a retrospective study the results of 2713 hip arthroplasties were reviewed. Sixty-one cases (2.24%) of post-operative neuropathy were identified, 13 of the sciatic nerve, 33 of the peroneal nerve and 15 of the femoral nerve. The risk is significantly higher in revisions (3.06%), especially when exchanging the acetabular component (8.5%) rather than in primary arthroplasties (2.13%). After an average period of 107 months (11 – 240) from operation, 41 patients with nerve lesions were questioned about their subjective functional capacity: 17% had recovered completely, 39% had noticed an improvement, and in 44% there was no change; 56.1% complained of weakness and had a complete paralysis. In all cases there was dysfunction of sensibility. Another 17.1% had a sensibility defect without weakness. There was pain in 51.2%, paraesthesia in 34.1% and areas of complete anaesthesia in 19.5%. Altogether 61% of the 41 patients had either gait problems or were dependent on orthotic devices. In summary, only about a third of the patients studied achieved a satisfactory degree of functional recovery.

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Résumé. Bien que les lésions nerveuses soient assez rares après l’implantation de prothèses totales de la hanche, il s’agit d’une complication grave pour le patient. Dans une étude rétrospective, on a analysé les résultats de 2723 endoprothèses totales: il y avait 61 cas de neuropathie postopératoires, 13 cas concernaient le nerf sciatique, 33 cas le nerf sciatique poplité externe et 15 cas le nerf crural. Le risque augmente d’une manière plus significative en cas de révision (3,06%) – surtout en cas de changements isolés du cotyle (8,5%) – qu’en cas d’implantation de prothèses primaires. Après une durée moyenne de 107 mois (11 – 240), 41 patients ont été interrogés sur leurs pertes fonctionnelles actuelles: 17% parlaient d’une récupération complète, 39% d’une récupération partielle, et 44% d’une absence de récupération.

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Accepted: 29 April 1996     

The use of the D-dimer test in combination with non-invasive testing versus serial non-invasive testing alone for the diagnosis of deep-vein thrombosis.

We studied the usefulness of the determination of plasma D-dimer levels (using an ELISA) in combination with non-invasive testing with impedance plethysmography (IPG) or real-time ultrasonography (US) for the diagnosis of deep-vein thrombosis (DVT), in outpatients with clinically suspected DVT. This combined approach was compared to serial non-invasive testing alone in these patients. The sensitivity of a positive D-dimer test (greater than 300 micrograms/l) for the presence of DVT was 100% (70/70 patients; 95% C.I.: 95-100%), whereas the specificity was 29% (69/239 patients; 95% C.I.: 23-34%). The proportion of patients in which a definitive decision about the presence or absence of DVT could be made on the day of referral, was calculated for both approaches. When applying the combined approach, in 42% of all referred patients the diagnosis of DVT could either be established or refuted on entry, as opposed to only 19% of patients using serial non-invasive testing alone. Also, the costs per DVT diagnosed were calculated for the two diagnostic approaches. For the diagnosis of DVT the costs using serial IPG were comparable to the costs using the combination of IPG and the D-dimer test. The same conclusion holds for the comparison of serial US with the combination of US and D-dimer testing. We conclude that for the diagnosis of DVT in symptomatic outpatients the combination of non-invasive testing with the D-dimer test might be preferred over serial non-invasive testing alone, although the safety of such an approach remains to be established in future management studies.     

The resonator theory of colour vision.

The resonator theory claims that light scattering by the melanin granules of the retinal pigment epithelium causes light to be reflected back through the outer segment of the cones, in a direction opposite that of the incident light. These two opposite directed wave motions may produce standing waves inside the cone outer segment, which then acts as a resonating cavity for light waves. The wavelength specificity of the single cone is determined by the length and the diameter of the cone outer segment. The variation of the length and the diameter of the cone outer segments throughout the retina is then the basis of colour discrimination.     

Effects of local hyperthermia on the tissue levels and toxicity of three radiosensitizers in mice.

The toxicity of the radiosensitizers misonidazole (MISO), demethylmisonidazole (DEMISO) and pimonidazole (PIM) in mice can be affected differently when combined with local hyperthermia at 43 degrees C for 30 min. At a dose of 1 mg/g, only MISO plus heat resulted in 50% lethality in animals over a period of 7 days post-treatment, whereas 100% survival was observed in the case of DEMISO and PIM. The enhanced lethality may be associated with the production of toxic intermediates of MISO. Heat did not affect the levels of DEMISO in the tissues studied (plasma, brain and tumour), whereas those of PIM were markedly lowered in tumour but not affected in brain for up to 4 h after combined treatment. MISO was found to be decreased in the tumour at all times but affected differently in brain after 1 and 2 h, initially decreasing and then increasing significantly. In all cases the treatment sequence, i.e. sensitizer plus heat or vice-versa, did not affect the rate of survival. At a dose of 2 mg/g, DEMISO plus heat was found to be more toxic when DEMISO was given first (25% survival) compared to 58% on reversal. However, the levels of DEMISO in the tissues were not affected by heat. Thus, it would appear that there is no correlation between parent drug levels measured in plasma, tumour or brain and hyperthermia-induced drug lethality.     

Benzamide potentiation of the cytotoxicity of bifunctional galacticol in resistant P388 leukemia correlates with inhibition of DNA ligase II

Summary Benzamide (BA) enhances the cytotoxicity of 1,2:5,6-dianhydrogalactitol (DAG) in resistant P388 leukemia cell lines but not in the sensitive parent line. To examine the reason for this difference in response, we carried out an alkaline elution assay using proteinase K to study DNA interstrand cross-linking. At early time points, equal concentrations of DAG produced the same level of interstrand cross-linking (ICL) in the resistant and sensitive P388 leukemic cells, although marked differences were observed in their cytotoxicity toward the two cell lines. In the sensitive cells, neither the amount of DNA cross-linking nor the cytotoxicity changed during the observation period (38 h) in either the presence or the absence of BA. In contrast, the elution rate of the DNA of DAG-treated resistant cells increased with time and had reached the control levels by 38 h. However, when these cells were postincubated with BA for 38 h, the elution rate of DNA was much faster than that observed for the untreated resistant cells, indicating an accumulation of DNA singlestrand breaks (SSB). The SSB accumulation caused by BA was associated with an inhibition of the activity of ligase II enzyme, which was stimulated when resistant cells were treated with DAG alone. The potentiating effect of BA on the resistant cells can thus be related to the inhibiting action of BA on the DNA-rejoining enzyme, ligase II. The lack of sensitization by BA of the DAG-treated parent cell line may be attributable to the absence of DNA-SSB formation, which is necessary for ligase II activation through the stimulation of poly(ADP-ribose) synthesis.