Nanoscaled ultrasound contrast agents for enhanced sonothrombolysis.

Sonothrombolysis, the enhancement of thrombolysis with ultrasound (US), is widely used in clinical practice. The use of an ultrasound contrast agent can lead to a further reduced recanalization time of the occluded blood vessel and thus to better outcome for the patient. In this study the sonothrombolytic efficacy of our new nanoscaled ultrasound contrast agent (NUSCA) was investigated. This new contrast agent has a size of less than 100 nm and should thus be able to penetrate the thrombus and achieve a thrombolysis from inside out. In this study human whole blood clots were exposed to US, US and NUSCA, US and recombinant tissue plasminogen activator (rt-Pa) or urokinase (UK), or a combination of US, NUSCA and thrombolytic drug in a closed-loop flow model. We sonicated with diagnostic US at a frequency of 2.85 MHz for 30 min. Clot mass loss of 50.6 ± 6.0% for the combination of US, NUSCA and rt-PA was found. Using UK as thrombolytic drug 57.7 ± 9.0% clot mass loss could be seen. Thus the weight loss exceeded the conventional values of up to 30%. Scanning electron microscopy (SEM) images revealed changes of the fibrin network on the thrombus surface. The NUSCA was able to loosen the network and induce large pores in the thrombus surface. The high rates of clot mass loss and the obvious changings of fibrin structure make our NUSCA a promising tool for sonothrombolytic therapy.

Optimized thermosensitive liposomes for selective doxorubicin delivery: formulation development, quality analysis and bioactivity proof.

In our study we examined thermosensitive liposomal formulations (TL) from the perspective to minimize the general toxicity drawbacks of chemotherapy. The TL become active in response to local hyperthermia (LH), and remain inactive at physiological conditions. Here, we formulated novel doxorubicin loaded thermoliposomes (Dox-TL) with optimized characteristics and tested their biological activity in vitro. The liposomal membrane composition of Dox-TL and their preparation technology were adjusted for high drug loading and extended formulation stability. The 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC):1,2-distearoyl-sn-glycero-3-phosphocholine (DSPC):cholesterol(Chol):1,2-distearoyl-sn-glycero-3-phosphoethanolamine-N-[maleimide(polyethylene glycol)-2000] (ammonium salt) (DSPE-PEG-2000) in molar ratio 9:1:0.2:0.02:0.2 and drug/lipid weight ratio 0.13-0.20/1 composition has demonstrated best results. The freshly-prepared vesicles contained 94% doxorubicin. The Dox-TL, freeze-dried with 4% sucrose, maintained high level of encapsulated drug, remained stable in serum and prevented premature drug leakage. The Dox-TL proved to be significantly less toxic at 37°C than free Dox. In combination with local hyperthermia of 42.5°C Dox-TL were as effective as free Dox in cell survival, and even outperformed free Dox in proliferation activity suppression, colony proliferation rate, and cellular uptake. These findings represent a solid basis for a safer and more effective antitumor therapy.

A new molecular phylogenetic hypothesis for the evolution of freshwater eels.

Phylogenetic analysis of a segment of the mitochondrial 16S rDNA of eight Anguilla species from the Indo-Pacific region and from the North Atlantic revealed that the genus Anguilla appears to be surprisingly young, based upon the small observed maximum genetic distance of 4.8% and the high degree of morphological similarity among the species. The placement of A. marmorata as the most ancestral lineage suggests that the genus is likely to have originated in the Indo-Malayian region, from which it quickly spread. Two Pacific species, A. obscura and A. japonica, branched next. A. japonica was placed as sister group to all remaining species, which formed three clades: the first comprising A. australis, the second A. reinhardti and A. mossambica, and the third A. anguilla and A. rostrata. All analyzed specimens of A. rostrata originating from southern New Jersey to Nova Scotia had identical mitotypes, while five mitochondrial genotypes were found in Europe differing by zero to two substitutions. The two Atlantic eel species are very closely related; all surveyed specimens of A. anguilla differ by three to five substitutions from their American allies, corroborating the existence of two distinct biological species. This was also confirmed by restriction analysis of a 350-bp segment of the cytochrome b, in which American specimens were distinct in sharing a single diagnostic restriction site of HinfI. Our results suggest little to no gene flow between the two nominal Atlantic eel species.

Soluble and membrane-bound ferrisiderophore reductases of Escherichia coli K-12.

After uptake of microbial ferrisiderophores, iron is assumed to be released by reduction. Two ferrisiderophore-reductase activities were identified in Escherichia coli K-12. They differed in cellular location, susceptibility to amytal, and competition between oxygen and ferrichrome-iron(III) reduction. The ferrisiderophore reductase associated with the 40,000 X g sediment (membrane-bound enzyme) was inhibited by 10 mM amytal in contrast to the ferrisiderophore reductase present in the 100,000 X g supernatant (soluble enzyme). Reduction by the membrane-bound enzyme followed sigmoid kinetics, but was biphasic in the case of the soluble enzyme. The soluble reductase could be assigned to a protein consisting of a single polypeptide of Mr 26,000. Reduction of iron(III) by the purified enzyme depended on the addition of NADH or NADPH which were equally active reductants. The cofactor FMN and to a lesser degree FAD stimulated the reaction. Substrate specificity of the soluble reductase was low. In addition to the hydroxamate siderophores arthrobactin, schizokinen, fusigen, aerobactin, ferrichrome, ferrioxamine B, coprogen, and ferrichrome A, the iron(III) complexes of synthetic catecholates, dihydroxy benzoic acid, and dicitrate, as well as carrier-free iron(III) were accepted as substrates. Both ferrisiderophore reductases were not controlled by the fur regulatory system and were not suppressed by anaerobic growth.

On the image of child psychiatry amongst the people and the parents concerned.

In questionning altogether 313 parents who had made use of the help of child psychiatry, as well as parents who had taken their child to a children's hospital, or persons who lived in the vicinity of a child psychiatric clinic, clear prejudices against children who had undergone child psychiatric treatment, their families and facilities were found. The child and adolescent psychiatrist's job description and his sphere of responsibility were indefinite and not well-defined in comparison with other professional groups (e.g. psychologists). His advice was often only sought for after other facilities, above all paediatricians and educational advice centres, had been consulted without the desired success. Parents who had made use of a child psychiatrist's help were less inclined to prejudices and were better informed than the other two groups mentioned above. Even today however, patients who have undergone psychiatric treatment and their families still have to reckon on reservations in their social surroundings especially from other children.

[Homicides by adolescents and young adults from the viewpoint of the adolescent psychiatry expert]. / Tötungsdelikte Jugendlicher und Heranwachsender aus der Sicht des jugendpsychiatrischen Gutachters.

From 1966 to 1986, the Department of Child and Adolescent Psychiatry of the Psychiatric Hospital of the University of Heidelberg gave expert opinions at the request of criminal courts in 37 cases involving homicide and 8 attempted homicide. Eighteen of the offenders were between 14 and 17 years old ("Jugendliche" under German law), 17 between 18 and 20 ("Heranwachsende") and 2 over 20. The largest group (N = 18) consisted of maladjusted male adolescents who had grown up in disadvantageous surroundings, had limited education and, not infrequently following the example of other members of their families, tended to show aggressive behaviour, intolerance to frustration, emotional instability and uncontrolled drinking. The questions the expert was asked by the court were mainly concerned with: liability for crime (section 3 JGG), applicability of juvenile law to offenders aged 18 to 20 years (section 105 JGG) penal responsibility (section 20 and 21 StBG or section 51, Section 1 and 2 StGB a.F.), and measures under section 63 StGB. The court took the expert's position in 28 of the 33 decisions which we were able to obtain for examination; 2 other proceedings were quashed. The juridical classification of the homicides was attempted or completed first-degree murder in 17 and attempted or completed second-degree murder in 6 cases.

Mortality of patients dependent on benzodiazepines.

For patients dependent on benzodiazepines alone, or in combination with alcohol and/or other legal and illegal drugs, observed mortality rates were compared with the average population, and, in cases of isolated benzodiazepine dependence, also with a control group of non-dependent patients chosen to match each dependent not only in sex and date of birth, but also in pre-existing psychiatric illness besides dependence. For patients with an isolated benzodiazepine dependence, the mortality rate was increased, when compared with the average population, by a ratio of observed to expected numbers of deaths of about 3. However, this mortality rate did not differ from that of the control group (non-dependent patients with comparable psychiatric illnesses). For patients combining benzodiazepines with alcohol among other addictive drugs, and for patients combining benzodiazepines with illegal drugs among other addictive substances, the ratio of observed to excepted numbers of deaths was 6.2 resp. 21, thus corresponding well with other studies on mortality rates associated with alcoholism and dependence on illegal drugs. We conclude that our study does not give evidence of higher risk of early death correlated with dependence on benzodiazepines alone. However, it confirms the well-known fact of increased mortality rates in patients with psychiatric illnesses, especially with dependence on alcohol or illegal drugs.

[Catamnestic study of the problem of the course and diagnostic changes in 22 adolescents with affective psychosis]. / Katamnestische Untersuchung zur Frage des Verlaufs und Diagnosewechsels bei 22 an Affektiver Psychose erkrankten Jugendlichen.

Among the adolescents seen as inpatients at the University of Göttingen psychiatric hospital in 1972 and 1973, the diagnosis of affective psychosis was made about as often as that of a schizophrenic psychosis, both being rare compared with the total number of children and adolescents treated. At 10- to 11-year follow-up it was found that 4 of the 22 patients with affective psychoses had committed suicide. Only 3 patients had not required subsequent inpatient care. In 2 cases the diagnosis had to be changed to a schizophrenic psychosis, and in 1 to exogenous psychosis. The outcome was more favorable with regard to the subjects' social and occupational development. Most had been able to complete their schooling and to enter their chosen occupation. Only 2 were unemployed.

Some principles of flexor reflex generation in human leg muscles.

Flexor reflexes, evoked by stimulation of the tibial and deep peroneal nerves at the ankle level, were investigated in several ipsi and contralateral human leg muscles. On both sides, the reflex consist of a stereotyped oscillating sequence of inhibition and facilitation, exhibiting specifity to the stimulated site only in the initial ipsilateral phases. The responsible afferents were identified as belonging to a group of non-nociceptice skin afferents with a maximum conduction velocity of about 40-54 m/sec. Interdependence was observed between both latencies and amplitudes of the individual phases of the reflex sequences in synergistic and antagonistic pairs of muscles. It is concluded that the function of such a conjoint reflex generation in different muscles is to ensure an organized and adequate withdrawal.

Reflexes evoked in leg muscles from arm afferents: a propriospinal pathway in man?

Long-loop reflexes from arm afferents onto motoneurones of leg muscles were investigated in 57 healthy subjects by means of H reflex testing and tonic EMG testing. In various tonically activated leg muscles, brachial nerve stimulation exerted stereotyped reflex responses which regularly consisted of an initial depression phase (mean onset latency: 60 ms) and a subsequent facilitatory phase (mean onset latency: 80 ms). H reflex studies, in contrast, only revealed the later facilitation. Except for this difference, both methods led to similar results: fibres responsible for the response were identified as low-threshold skin afferents with a conduction velocity of about 40 m/s. Noxious stimulation reinforced the effects of innocuous stimulation. The receptive field for the reflex response was not restricted to the ipsi- and contralateral arm regions but included the face and the rostral part of the trunk above the buttock. Percutaneous stimulation of dorsal roots C4 and T9, respectively, resulted in a shortening of the onset latencies of both depression and facilitation, with T9 stimulation. It is therefore suggested that the reflexes described are mediated via a directly descending, long spinal pathway.

Response patterns of human lumbo-sacral motoneurone pools to distant somatosensory stimuli.

The response of human lumbo-sacral motoneurones to electrical stimuli applied to the trunk, the face and the arms was evaluated by means of H reflex testing in extensors and averaging the rectified tonic EMG recorded from extensors as well as flexors. In extensor and flexor muscles, the reflex pattern consisted of a non-reciprocal inhibition-facilitation, occurring with latencies of about 60 and 80 msec, respectively. With reflex testing, only facilitation was observed in extensors, beginning after a conditioning-test interval of about 40 msec and peaking at about 80 msec. This discrepancy was interpreted to indicate excitation supraliminal in a facilitatory and subliminal in an inhibitory pathway, the latter requiring an additional input to impinge on motoneurones. Afferents responsible for the described reflex actions were identified as belonging mainly to low-threshold skin nerve fibres, conducting with a maximum velocity of about 45--50 m/sec. However, medium threshold skin afferents as well as muscle and joint afferents may also play a role. Stimulation of C5 and T10 skin areas close to the neuraxis revealed similar effects, the latencies being shorter or equal with T10 compared with C5 stimulation. The possibility of a directly descending propriospinal pathway is discussed, mediating the inhibitory as well as the excitatory reflex actions described.