Reliability of left atrial pressure estimation from left ventricular filling measurement in a total artificial heart.

A physiological control of a total artificial heart (TAH) requires reliable information on left arterial pressure (LAP). When LAP is derived indirectly from intrinsic TAH parameters like end diastolic volume (EDV) and diastole duration (Td), the transfer function and associated uncertainties need to be well understood.We derived a computational equivalent to a hydraulic model consisting of the venous compliance, the heart valve and the pump chamber, and studied the filling phase in cases of different venous compliance. We calculated a family of curves of pump chamber volume as a function of time for different venous compliances and LAP. To visualize the LAP transfer function and uncertainties associated to EDV, Td measurement error and unknown venous compliance a family of similar curves in the vicinity of assumed measurement was found and visualised in the parameter space.Results were in a realistic absolute range and showed expected trends despite some simplifications in the simulation model. The venous compliance has no significant influence on LAP values extracted from EDV and Td, except at very low values. The uncertainty in the extracted LAP is particularly high for high EDV and short Td.A physiological regulation therefore does not have to be individually adapted to the patient's venous compliances, but has to deal with uncertainties in the input values like blood pressures extracted from intrinsic device parameters.

[Bladder dysfunction caused by a large presacral retention mucocele]. / Blasenfunktionsstörung in Folge einer grossen präsakralen Retentionsmukozele.

Large pelvic masses can displace the urinary bladder and cause bladder dysfunction with various symptoms. We report the case of a 42-year-old man who described a feeling of reduced urinary stream and bladder filling and residual urine since his youth. After various unsuccessful conservative treatments, the patient was evaluated by our neuro-urologic department. The diagnostic workup revealed a large cystic mass that displaced the urinary bladder. Histopathological examination showed a retention mucocele (the patient had been surgically treated for connatal anal atresia). The lesion was surgically excised.

Sensitivity of different prothrombin time assays to factor VII deficiency in canine plasma.

The factor VII sensitivity of prothrombin time (PT) in dogs was tested using five different PT reagents and a commercial PT variant. The five PT reagents were used according to manufacturers' instructions (standard test, PT([ST])) and also using a modified test instruction (modified test, PT([MT])). Plasma samples with defined factor VII levels (10-100%) were prepared by adding increasing quantities of canine factor VII deficient plasma to the pooled plasma of healthy dogs. Statistical comparison based on prothrombin time ratios (PTR = PT sample: PT measured for 100% factor VII activity level) revealed significant differences between different reagents for PT([ST]) and also for PT([MT]). Factor VII activity at which PT was prolonged to the upper limit of the reference values (FVII([X(0.975)])) was 16-39% (PT([ST])) and 23-35% (PT([MT])). Factor VII sensitivity measured by PTR and also by FVII([X(0.975)]) values, was higher in four of five PT reagents using PT([MT]) when compared with PT([ST]). The results of this study indicate the importance of selecting a sensitive reagent and method for PT measurement and for careful interpretation of PT test results using canine plasma.

Early magnetic resonance imaging of brainstem lesions after severe head injury.

OBJECT: The availability of magnetic resonance (MR) imaging data obtained in comatose patients after head injury is scarce, because MR imaging is somewhat cumbersome to perform in patients requiring ventilation and because, in the first hours after injury, its relevance is clearly inferior to computerized tomography (CT) scanning. The authors assessed the value of MR imaging in the early postinjury period. METHODS: In this prospective study MR imaging was performed in 61 consecutive patients within 7 days after they suffered a severe head injury. An initial CT scan had already been obtained. To understand the clinical significance of the lesions whose morphological appearance was identified with MR imaging, brainstem function was assessed by registration of somatosensory and auditory evoked potentials. Brainstem lesions were visualized in 39 patients (64%). Bilateral pontine lesions proved to be 100% fatal and nonbrainstem lesions carried a mortality rate of 9%. In singular cases circumstances allowed for a clear clinical distinction between primary and secondary brainstem lesions. On MR imaging all lesions were hyper- and hypointense after intervals longer than 2 days. Within shorter intervals (< 2 days) after the injury, primary lesions appeared isointense on MR imaging. In one secondary brainstem lesion there were no traces of blood. CONCLUSIONS: Because mean intracranial pressure (ICP) levels in patients without brainstem lesions were similar to those in patients with brainstem lesions, the authors conclude that it was not mainly increased ICP that accounted for the high mortality rates in patients with brainstem lesions. The authors also conclude that brainstem lesions are more frequently found in severe head injury than previously reported in studies based on neuropathological or CT scanning data. Early MR imaging after head injury has a higher predictive value than CT scanning.

Environmental hazard assessment of pharmaceuticals.

The pharmaceuticals and pharmaceutical metabolites salicylic acid, paracetamol, clofibrinic acid, and methotrexate were examined with regard to their biological degradability and toxicity toward algae, Daphnia, fish embryos, luminescent bacteria, ciliates, and the fish cell line BF-2. The EC50 values calculated for the most sensitive organismic test (all except cell cultures) in each case were for salicylic acid, 37 mg/L (fish embryos); for paracetamol, 50 mg/L (Daphnia); for clofibrinic acid, 86 mg/L (fish embryos); and for methotrexate, 45 mg/L (ciliates). However, in the case of paracetamol, clofibrinic acid, and methotrexate, the fish cell line BF-2 reacted even more sensitively with EC50 values of 19 mg/L (paracetamol), 14 mg/L (clofibrinic acid), and 3 mg/L (methotrexate). Salicylic acid and paracetamol proved to be easily degradable. The predicted exposure concentration calculated according to the procedure of the EU Draft Phase I for new pharmaceuticals (CEC III/5504/94, draft 4) was based on the total estimated quantity of these substances consumed and indicated that their entry into the environment is theoretically possible. These results show that (1) the four tested pharmaceuticals may be present in the environment, (2) the substances led to effects in at least one ecotoxicological test, and (3) the most sensitive reactions were observed for a nonstandard test which incorporates relevant end points for the respective pharmaceuticals. This demonstrates that a limitation to the standard tests (algae, Daphnia, and fish) would have underestimated the toxicity of paracetamol, clofibrinic acid, and methotrexate. In addition to improved exposure estimates, the EU guideline should therefore contain a test strategy adapted to their modes of action, which permits the definite identification of pharmaceuticals with high ecotoxic potential, and consequently the appropriate provisions.

Effects of [des-Tyr-D-Phe3]beta-casomorphin (2-5) on cortical EEG power spectra in rats.

The effects of the peptide [des-Tyr-D-Phe3]beta-casomorphin(2-5) (BCH-325; Pro-D-Phe-Pro-Gly; 2.27, 22.7, and 227 micrograms/kg) on cortical EEG power spectra in rats were studied compared to those of other psychotropic drugs, including diazepam, amitriptyline, haloperidol, and amphetamine. All drugs were injected IP, and cortical EEG power spectra were recorded from freely moving rats for 2 h postinjection. Administration of 22.7 and 227 micrograms/kg BCH-325 resulted in an increase in alpha-2 and beta-1 frequency bands and a decrease in slower frequencies (delta, theta). Our findings show that the effects of BCH-325 on cortical EEG power spectra differ from those of other psychotropic drugs.

Effects of [des-Tyr-D-Phe3]beta-casomorphin (2-5) on sleep pattern in rats.

The effects of the antidepressant-like acting peptide [des-Tyr-D-Phe3]beta-casomorphin(2-5) (Pro-D-Phe-Pro-Gly, BCH-325) on sleep were studied in rats. The rats received subcutaneous injections of BCH-325 in acute experiments (doses: 4, 20, 100, 500 and 2500 nmol/kg) and in a 10-day chronic experiment (50 nmol/kg/day). Acute administration of 20 and 100 nmol/kg enhanced wakefulness, 500 and 2500 nmol/kg enhanced paradoxical sleep, and 4 nmol/kg had no effect. Chronic administration resulted in an increase of paradoxical sleep during the first 5 days of drug treatment. Thus the sleep effects of BCH-325 differ from those of typical antidepressants and other psychotropic drugs.

[The natural occurrence of odd numbered fatty acids in animals and in the human]. / Zum natürlichen Vorkommen ungeradzahliger Fettsäuren im tierischen Organismus und im Menschen.

There are figures to the natural occurrence of saturated and unsaturated odd numbered fatty acids (C11 to C21) in food stuffs. Data from literature about the occurrence of these fatty acids in maritime animals, poultry, agricultural animals as well as in laboratory animals and men were presented.

[24-hour CA 15/3 serum concentrations in patients with primary and metastasizing breast cancer]. / CA-15/3-Serumkonzentrationen während 24 h bei Patientinnen mit primärem und metastasiertem Mammakarzinom.

Serum determinations of tumor-associated antigens in breast cancer patients are utilized for detection of metastases as well as prediction of treatment response. That is critically dependent on the validity of single daily marker determination. In our study in patients suffering from primary or metastatic breast cancer we could demonstrate fluctuations of antigens detected with the two monoclonal antibodies 115D8 and DF3 (CA-15/3) during a 24 h observation period. Beside methodical inaccuracies those fluctuating serum concentrations might be related to biological phenomena. However, on basis of our data no intra- or interindividual rhythms could be exhibited.

Rhythmic fluctuations of CEA serum levels in breast cancer patients.

Hourly blood sampling for CEA determination was performed in metastatic breast cancer patients before and during medical treatment. Rhythmic fluctuations of marker concentrations could be detected. These oscillations seemed to be independent of the localisation of metastases and the kind of treatment. No relation between cortisol or prolactin and CEA levels became apparent.