[Extracorporeal membrane oxygenation and severe traumatic brain injury. Is the ECMO-therapy in traumatic lung failure and severe traumatic brain injury really contraindicated?]. / Extrakorporale Membranoxygenierung und schweres Schädel-Hirn-Trauma : Ist der ECMO-Einsatz bei polytraumatisierten ARDS-Patienten mit schwerem SHT wirklich noch kontraindiziert?

Veno-venous extracorporeal membrane oxygenation (ECMO) may be lifesaving in multiple injured patients with acute respiratory distress syndrome (ARDS) due to chest trauma. To prevent circuit thrombosis or thromboembolic complications during ECMO systemic anticoagulation is recommended. Therefore, ECMO treatment is contraindicated in patients with intracranial bleeding. The management of veno-venous ECMO without systemic anticoagulation in a patient suffering from traumatic lung failure and severe traumatic brain injury is reported.

Pumpless extracorporeal lung assist as supportive therapy in a patient with diffuse alveolar hemorrhage.

Our 18-year old female patient suffered from microscopic polyangiitis. After invasive diagnostics, a diffuse alveolar hemorrhage occurred, leading to acute lung failure. In spite of differential ventilation, respiratory insufficiency and lactate-acidosis increased quickly. Due to the massive hemorrhage, a pumpless extracorporeal lung assist was implanted and, after six hours, low-dose heparinization was started. In response to this therapy, hypercapnia and acidosis improved quickly and were completely eliminated within 24 hours. Simultaneously, treatment with prednisolon and cyclophosphamid was started. After 7 days, the patient's conditions allowed weaning from the pumpless extracorporeal lung assist and after 9 days she was extubated. In conclusion, the pumpless lung assist was shown to be a very practical option to treat the most serious forms of hypercapnia, especially for patients disposed to diffuse bleeding.

Assessment of the androgen environment within the human testis: minimally invasive method to obtain intratesticular fluid.

Previous studies of the rat have shown that testosterone concentrations within the interstitial and seminiferous tubularfluids of the testes are significantly higher than normal serum levels, and further, that although intratesticular testosterone concentration can be substantially reduced without an effect on spermatogenesis, the concentration that is minimally required to maintain spermatogenesis is also substantially higher than serum levels. The purpose of the present study was to adapt a minimally invasive technique to sample human intratesticular fluid to enable parallel observations in man. To this end, aspiration methods were first developed for the rat testis and then adapted to the human. The testosterone concentration in fluid obtained by unilateral aspiration of rat testes was approximately 50 ng/mL, similar to the known concentration in seminiferous tubular fluid. These aspiration methods were then adapted to obtain intratesticular fluid from human testes. Studies of 12 fertile human subjects demonstrated that percutaneous testicular aspiration could be performed safely and successfully using a 19-gauge needle. Nine additional human subjects had bilateral testicular aspiration and simultaneous measurement of peripheral blood testosterone levels. Testicular aspirations yielded 8 to 117 microL of fluid from each testicle. The mean concentration of testosterone in aspirates obtained from the 21 patients was 609 +/- 50 ng/mL. Dihydrotestosterone and 3alpha-androstanediol concentrations were quite low, below the limits of detection of our assay. The SHBG/ABP concentration in the aspirates was 8.5 +/- 1.1 nM. These results define testosterone as the major androgenic steroid in the human testis, as in the rat testis, and indicate that the testosterone concentration within the human testis is approximately 200-fold greater than that of SHBG/ABP, and more than 100-fold greater than the concentration of testosterone found in normal human serum.

Kinetic studies of Heck coupling reactions using palladacycle catalysts: experimental and kinetic modeling of the role of dimer species.

Experimental kinetic studies of the coupling of p-bromobenzaldehyde (1) with butyl acrylate (2) using the dimeric palladacycles complex (4) with chelating nitrogen ligands were carried out together with kinetic modeling using a reaction rate expression based on the mechanism shown in Scheme 2. The oxidative addition product of 1 was found to be the resting state within the catalytic cycle. The formation of dimeric Pd species external to the catalytic cycle helped to rationalize a non-first-order rate dependence on catalyst concentration. Theoretical modeling showed how the relative concentrations of the different intermediate species within the catalystic cycle can influence the observed rate dependence on Pd concentration. It was shown how conventional kinetic studies may give reaction orders in substrates which differ from those which would be observed under practical synthetic conditions. Comparison between phosphine- and nonphosphine-based palladacycles suggests that they follow the same reaction mechanism. The role of water in accelerating the initial formation of the active catalyst species is noted.

Kinetic investigations of product inhibition in the amino alcohol-catalyzed asymmetric alkylation of benzaldehyde with diethylzinc

In situ reaction rate measurements help to define the role of product inhibition in the asymmetric alkylation of benzaldehyde with diethylzinc using (-)-MIB as a chiral reagent. Reaction calorimetry and kinetic modeling demonstrated that the rate behavior over consecutive reactions may only be rationalized when reversible binding of the product alkoxide is taken into consideration. These results may have implications for the conversion dependence of product enantioselctivity in reactions using enantioimpure catalysts.

Enantioselective hydrogenation of olefins with phosphinooxazoline-iridium catalysts.

Cationic iridium complexes with chiral phosphinooxazoline ligands are efficient catalysts for the enantioselective hydrogenation of olefins. The complexes are readily prepared, air-stable, and easy to handle. In contrast to chiral rhodium- and ruthenium-phosphine catalysts, they do not require the presence of a polar coordinating group near the C=C bond. In the hydrogenation of unfunctionalized trisubstituted 1,2-diaryl-olefins, high enantioselectivities of >95% ee with full conversion and turnover frequencies of >7,000 h-1 can be achieved, using 0.1 mol% of catalyst with tetrakis[3, 5-bis(trifluoromethyl)phenyl]borate (TFPB or BARF) as the counterion. The corresponding hexafluorophosphate or tetrafluoroborate salts give low conversion due to deactivation of the catalyst during the reaction. Substrates with polar substituents such as allylic alcohols, on the other hand, afford better results with the hexafluorophosphate salts.

Kinetic Influences on Enantioselectivity for Non-Diastereopure Catalyst Mixtures.

Different kinetic rate laws were observed for two diastereomeric catalysts which separately gave opposite enantioselectivities in the asymmetric hydrogenation of the dimethyl ester of itaconic acid. In reactions carried out using an equal mixture of the two catalysts, a conversion-dependent enantioselectivity was predicted from the separate reaction-rate data, in agreement with the experimentally observed final enantioselectivity of 54.8 % ee (see diagram).

Tourette's syndrome.

1. Tourette's syndrome is a disorder with a multitude of complex behavioral problems with major implications for social impairment and emotional pain. 2. The generic care plan anticipates the predictable management problems in adolescent patients. It offers nursing interventions, particularly structure, which is important in managing symptoms. 3. The treatment process is slow. The successful implementation requires consistent efforts from the nursing staff, treatment team, and family.

Visual barriers to prevent ambulatory Alzheimer's patients from exiting through an emergency door.

Mobility combined with impaired mental functioning presents safety risks for Alzheimer's patients and poses an ethical dilemma for staff. This study, conducted on an Alzheimer's unit, tested seven different visual barrier conditions for reducing patient exists. Findings indicate that exiting was eliminated under two conditions. The results suggest visual agnosia, the inability to interpret what the eye sees, may be utilized as a tool in managing wandering behavior of Alzheimer's patients.

Physician use among the old-old. Factors affecting variability.

A random sample of 189 noninstitutionalized adults aged 75 and older was used to examine the influence of personal and social characteristics of the old-old on physician use. A path analysis traced direct and indirect effects of predisposing, enabling, and need variables within Andersen's health-behavior model. Income and perceived severity of symptoms were the only two variables with direct causal effects, whereas education, gender, race, living arrangements, and number of symptoms influenced physician use indirectly. Implications of the heterogeneity of the old-old for future research in health behavior are discussed.

Calculation of a mean functional diameter of capillaries of isolated rabbit hearts and changes of this diameter during hypoxia. Pathophysiological and pharmacological studies.

Isolated rabbit hearts were perfused aerobically (45 min) and hypoxically (105 min), using a modified Langendorff technique. The mean functional diameter of capillaries (MFDC) was calculated from the perfusion rate per minute and the inflow resistance by the model of Hagen-Poiseuille. The MFDC expresses the mean lumen of all capillaries of the heart, regardless of the different behaviour of the capillaries in the different regions of the myocardium. The MFDC decreased very rapidly after the onset of a hypoxia from 3.5 +/- 0.3 micron to about 70% of the initial diameter within 5-10 min (p less than 0.01) and then in a slower range within the following 70 min to about 44% of the initial diameter. The release of lactate dehydrogenase (LDH) from the hypoxic myocardium was detectable after 45 min of hypoxia and rose drastically after 60 min of hypoxia in our model. The decrease of the MFDC as well as the release of LDH from the hypoxic myocardium can be diminished by application of O-(beta-hydroxyethyl)-rutoside or 10 mM mannitol to the hypoxic perfusion medium. Both substances have antioxidant activities. It is discussed that the injury of the microvasculature is an early process during hypoxia, which can potentiate the hypoxic changes of the myocardial cells by additional diminution of the supply with oxygen and substrates. The protecting activities of substances with antioxidant actions to hypoxic myocardium were supported.

Autogenous dermal grafting vestibuloplasty in dogs.

Vestibuloplasties were done in dogs, using autogenous dermis as a graft material. Clinical and histologic examination was done at 10, 17, 21, and 28 days. Results showed good graft take and a final appearance resembling that of mucosa. Histologic findings correlated well with clinical appearance. From this investigation it appears that the dermis acts as a true graft and not just as a biologic dressing.

Anesthetic problems in patients taking lithium.

Lithium is becoming an extremely popular agent in the treatment of many psychiatric disorders. Because of its low therapeutic index and dose- and nondose-related side effects, patients receiving this medication can have problems that may complicate their anesthetic course. We present two case reports showing some of the potential difficulties that may be encountered with the use of lithium and review pertinent pharmacology to enable the oral and maxillofacial surgeon to deal effectively with patients receiving lithium therapy who are about to undergo anesthesia and surgery.