Laboratory monitoring of pentasaccharide in a dog model of hemodialysis

Varying dosages of pentasaccharide (400-800 nmol/kg) were compared to a 250-U/kg single bolus dosage of unfractionated heparin (UFH) in a dog model of hemodialysis. Several laboratory assays were used to monitor the effects of pentasaccharide and UFH. The pentasaccharide did not produce any anticoagulant effects as measured by the activated partial thromboplastin time. However, in the anti-Xa chromogenic assay and the Heptest assays, there was a dose-dependent prolongation after pentasaccharide administration. In the group of dogs administered 800 nmol/kg of pentasaccharide, there was a 50% decrease in the thrombin antithrombin (TAT) complex level after 60 minutes on dialysis. In the UFH-treated dogs, wide variations in assays were observed. There was a marked elevation in the activated partial thromboplastin time and Heptest assays up to 6 hours after UFH administration. Both anti-Xa and anti-IIa activity was measured up to 4 hours. In the TAT assay, UFH was found to have a stronger effect in suppressing the formation of TAT in comparison to the pentasaccharide. These results suggest that pentasaccharide can be used as a replacement for UFH in a dog model of hemodialysis to keep the dialysis circuit patent. In addition, the anti-Xa-based assays such as the Heptest and the chromogenic anti-Xa assays can be used to monitor the effects of pentasaccharide in this model.     

Discriminating mirror symmetry in foveal and extra-foveal vision

The ability to discriminate perfect from imperfect mirror symmetry was examined at the fovea and at eccentricities out to 10 degrees in the nasal visual field. A 2-AFC method of constant stimuli was employed in which a bilaterally symmetric pattern was presented in one interval and a degraded version of this symmetric pattern in the other. The subject's task was to decide which interval contained the perfectly symmetric pattern. Pattern size was varied by changing the viewing distance. Probit analysis revealed the degree of asymmetry corresponding to 75% correct performance. Given sufficient size scaling, perfectly symmetric stimuli can be discriminated from degraded symmetric stimuli in extra-foveal vision. Spatial scaling with an E2 value similar to that for positional acuity was successful in removing the eccentricity dependence for the task.     

Measurement of in vitro cellular pharmacokinetics of 5-fluorouracil in human and rat cancer cell lines and rat hepatocytes using a flow-through system

Summary A flow-throught system was used to study the cellular pharmacokinetics of 5-fluorouracil (5-FU) in four human cell lines (squamous-cell carcinoma HEp-2, colon carcinoma WiDr, hepatoma Hep G2, and breast carcinoma MCF-7) as well as in the rat hepatoma H35 cell line and in freshly isolated rat hepatocytes. The system made it possible to restrict the decrease in the concentration of 5-FU in the medium, to keep the volume in which the metabolites accumulated relatively small, and to study the dynamics of a response during and after a change in the composition of the eluent. Clearance of 5-FU from the eluent was achieved predominantly (>95%) by its catabolism to dihydrofluorouracil in the tumor cell lines and to 2-fluoro--alanine in the hepatocytes. Not only rat hepatocytes but also HEp-2 cells showed relatively high clearance values. A concentration-dependent 5-FU elimination was observed, indicating saturation of 5-FU elimination according to Michaelis-Menten kinetics (K_m 14–22 M). The maximal velocity (V_max) values ranged from 0.025 to 0.13 nmol 5-FU/10⁶ cells per minute. For HEp-2 cells, high-concentration pulse injections of 5-FU, thymine, uridine, or uracil immediately led to a reduction in 5-FU conversion, followed by recovery within 5 min. The flow-through system proved to be adequate for the study of the non-linear pharmacokinetics of 5-FU in different intact cells and for the comparison of various manipulations of these pharmacokinetics.Abbreviations 5-FU 5-fluorouracil - FUR 5-fluorouridine - F-DHU dihydrofluorouracil - F--ala 2-fluoro--alanine - F-UPA -fluoroureidopropionic acid - HEPES 4-(2-hydroethyl)-1-piperazine-ethane sulfonic acid - MEM modified minimal essential medium - HBSS Hanks' balanced salt solution - HPLC high-performance liquid chromatography Supported by grant IKA 87-16 from the Netherlands Cancer Foundation. One author (G. J. P.) is the recipient of a senior research fellowship from the Royal Netherlands Academy of Arts and Sciences (KNAW)     

Psychisch Kranke: Gesehen aus zwei verschiedenen Perspektiven Ein methodischer Beitrag zur Einstellungsforschung in der Psychiatrie

Zusammenfassung Anhand von Daten aus zwei Bevölkerungsumfragen zur Einstellung gegenüber psychisch Kranken wird untersucht, welchen Einfluss die Variation der Perspektive-die des Befragten selbst versus die der anderen-auf das Befragungsergebnis hat. Wie erwartet fällt das Urteil über psychisch Kranke positiver aus, wenn nach der eigenen Meinung gefragt wird, als wenn man das Urteil der anderen einschätzen lässt. Der Unterschied zwischen beiden Frageformulierungen nimmt mit dem Grad der Schulbildung zu und erreicht bei Personen mit Abitur ein substantiell bedeutsames Ausmass. Darüber hinaus sind die Antworten eindeutiger und pointierter, wenn nach der persönlichen Meinung gefragt wird.

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Summary The impact of the change in perspective (i.e. the personal opinion of those questioned versus what they perceive the others' opinion toward the mentally ill to be) on the results of the questionnaire is examined based on data from two population surveys measuring attitudes towards the mentally ill. As expected, the respondents' attitudes towards the mentally ill are more positive if they are asked to give their own opinion. The impact that the variation of the two formulations of these questions has on the respondents increases with their level of education and reaches a substantial amount among those with Abitur. Furthermore, the answers are clearer and more definite if those questioned are asked for their personal opinion.

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Résumé L'impact d'un changement de perspective (opinion personnelle comparée à l'opinion générale telle qu'elle est personnellement perçue) est examiné dans le cadre de deux études de population mesurant l'attitude envers les malades psychiques. Comme on pouvait s'y attendre, l'attitude des répondants est beaucoup plus positive lorsqu'il s'agit de leur opinion personnelle. La divergence entre l'opinion personnelle et la perception de l'opinion générale augmente au fur et à mesure que le niveau d'éducation s'accroît. Les réponses sont d'autre part bien plus clairement formulées lorsque les personnes experiment leur opinion personnelle.

     

Mutagenicity of diisopropylamine dichloroacetate, the "active constituent" of vitamin B15 (pangamic acid)

Diisopropylamine dichloroacetate, the active component of many formulations of pangamic acid (trade-named "vitamin B15"), and diisopropylamine, a component of diisopropylamine dichloroacetate, both demonstrate mutagenicity in the Ames Salmonella/mammalian microsome mutagenicity test. Ninety percent of such agents prove carcinogenic, and this long-term possibility must be considered in any proposed use of pangamic acid containing diisopropylamine or diisopropylamine dichloroacetate.     

Comparison of pesticide and particulate recoveries with the vacuum and dislodgeable surface pesticide residue techniques

The dislodgeable and vacuum surface residue techniques were compared for the quantity of pesticide residue and quantity and quality of particulate matter removed from Valencia orange leaves. Data trends for dislodgeable and vacuum parathion and paraoxon residues were correlated at r0.95 for both emulsifiable concentrate and wettable powder formulations.The amount of pesticide residue and particulate matter obtained was dislodgeable > glass fiber filter > 5.0 filter > 0.8 filter. The flow rate of the filter was correlated with the amount of residue removed.The quality of particulate matter as judged by size analyses was equal The dislodgeable technique removed about five times more particulate material and about eleven times more pesticide residue compared to the vacuum technique.Florida Agricultural Experiment Stations Journal Series No. 745.     

Kahnbeinfrakturen – Diagnostik, Klassifikation und Therapie

Herbert's classification of scaphoid fractures provides the underlying rationale for treatment according to the fracture type. A CT bone scan in the long axis of the scaphoid is the best means of differentiating between stable and unstable fractures. This is difficult from conventional X-rays due to the particular three-dimensional anatomy of the scaphoid. To avoid long-term plaster immobilization and to diminish the risk of a nonunion, unstable fractures of type B should be fixed operatively. With headless screws such as the Herbert screw, which are now available in a cannulated shape, the majority of scaphoid fractures of type B1 and B2 can be stabilized using minimally invasive procedures. Severely displaced fractures require the classical open palmar approach. Proximal pole fractures (B3) are best managed from the dorsal approach, using the Mini-Herbert screw. Stable fractures of type A2 can be treated conservatively in a below-elbow cast or, alternatively, stabilized percutaneously, which allows early mobilization.     

Children of migratory agricultural workers: the ecological context of acute care for a mobile population of immigrant children

Migratory and seasonal agricultural workers fill the labor needs of United States farmers. Although migrant workers are a culturally and ethnically diverse population, presently, they are predominantly immigrants of Hispanic ethnicity. Migrant farm workers are increasingly young, financially impoverished, male, undocumented immigrants from Mexico. Families with children constitute 45% of this population. The ecological context of migrant children’s lives is characterized by poverty, social isolation, heightened inter- and intra-national mobility, limited protections from occupational safety and health legislation, and health access barriers. Moreover, the linkage of citizenship and immigration status to the receipt of public insurance and selected social services benefits has the potential to increase access barriers for migrant workers and their families. Despite these obvious vulnerabilities, few health services research studies address this population. Most of what is known relates to adults, with very little known about migrant children’s health services utilization patterns or health morbidities. In the emergency department setting, the differential approach required to care for children, as compared to adults, must be modified further in order to address the unique needs of this vulnerable population. The effective delivery of acute care to the children of migratory agricultural workers requires awareness of and attention to their unique health access barriers, issues of continuity and compliance with care, and their unique health and injury risks.     

Occupancy of striatal and extrastriatal dopamine D2/D3 receptors by olanzapine and haloperidol.

There have been conflicting reports as to whether olanzapine produces lower occupancy of striatal dopamine D(2)/D(3) receptor than typical antipsychotic drugs and preferential occupancy of extrastriatal dopamine D(2)/D(3) receptors. We performed [(18)F] fallypride PET studies in six schizophrenic subjects treated with olanzapine and six schizophrenic subjects treated with haloperidol to examine the occupancy of striatal and extrastriatal dopamine receptors by these antipsychotic drugs. [(18)F] setoperone PET studies were performed in seven olanzapine-treated subjects to determine 5-HT(2A) receptor occupancy. Occupancy of dopamine D(2)/D(3) receptors by olanzapine was not significantly different from that seen with haloperidol in the putamen, ventral striatum, medial thalamus, amygdala, or temporal cortex, that is, 67.5-78.2% occupancy; olanzapine produced no preferential occupancy of dopamine D(2)/D(3) receptors in the ventral striatum, medial thalamus, amygdala, or temporal cortex. There was, however, significantly lower occupancy of substantia nigra/VTA dopamine D(2)/D(3) receptors in olanzapine-treated compared to haloperidol-treated subjects, that is, 40.2 vs 59.3% (p=0.0014, corrected for multiple comparisons); in olanzapine-treated subjects, the substantia nigra/VTA was the only region with significantly lower dopamine D(2)/D(3) receptor occupancy than the putamen, that is, 40.2 vs 69.2% (p<0.001, corrected for multiple comparison). Occupancy of 5-HT(2A) receptors was 85-93% in the olanzapine- treated subjects. The results of this study demonstrated that olanzapine does not produce preferential occupancy of extrastriatal dopamine D(2)/D(3) receptors but does spare substantia nigra/VTA receptors. Sparing of substantia nigra/VTA dopamine D(2)/D(3) receptor occupancy may contribute to the low incidence of extrapyramidal side effects in olanzapine-treated patients.