[Impact of preoperative patient education on postoperative pain in consideration of the individual coping style]. / Einfluss präoperativer patienteninformationen auf postoperative schmerzen unter berücksichtigung individueller stressverarbeitung.

OBJECTIVE: the German guideline for the treatment of acute perioperative and post-traumatic pain (S3-Leitlinie zur Behandlung akuter perioperativer und posttraumatischer Schmerzen) recommends giving preoperative information about postoperative pain and how to influence it. It is expected that the effect of preoperative information is modified by psychological characteristics of the patient. One of these psychological characteristics is the individual coping style. The purpose of the study is to evaluate whether or not patients benefit from preoperative education in relation to their level of negative coping style. METHODS: the study is based on a 2×2 factorial experimental design with the experimental factor "treatment" (education vs control condition) and the factor "negative coping style" (high vs low). After informed consent 96 patients undergoing abdominal or vascular surgery were enrolled in the study. Outcomes were pain intensity, pain quality and psychic state. They were assessed by using numerical rating scales and psychometric methods of self-assessment. The data were collected preoperatively and on the first to third postoperative day. RESULTS: patients who received preoperative education experience a greater reduction in postoperative pain than patients without preoperative education do (ES=0.48). The risk for stronger pain (NRS>3) on the third postoperative day is decreased (2.1 vs 14.6%). The influence of negative coping style is altogether minimal. CONCLUSIONS: preoperative patient information has positive effects on the postoperative development of pain. Patient information is a valuable addition to the drug pain treatment. The application can be recommended regardless of the level of the patients' negative coping style.

Identification and characterization of a novel splicing variant of vesicular monoamine transporter 1.

Vesicular monoamine transporter 1 (VMAT1) is an integral protein in the membrane of secretory vesicles of neuroendocrine and endocrine cells that allows the transport of biogenic monoamines, such as serotonin, from the cytoplasm into the secretory vesicles. The full-length VMAT1 transcript is produced from 16 exons. We have identified and characterized an alternatively spliced form of VMAT1 that lacks exon 15, the next to last exon of VMAT1. The new form was therefore denoted VMAT1Delta15. Exon 15 does not contain an even multiple of three nucleotides. As a consequence, there is a shift of reading frame, and exon 16 is translated in an alternative reading frame, yielding a novel protein with a shorter and unrelated C-terminus compared with the native VMAT1 protein. VMAT1 and VMAT1Delta15 mRNAs are simultaneously expressed in normal and neoplastic neuroendocrine cells of the GI tract. However, VMAT1 expression is always higher than VMAT1Delta15 expression. We prove that VMAT1Delta15 is not localized in large, dense core vesicles as the native form but in the endoplasmic reticulum. Furthermore, while VMAT1 can take up serotonin, VMAT1Delta15 cannot, indicating different functions for the two forms of VMAT1.

Parental style. Mothers' and fathers' and perceptions of their relations with twin children.

Mothers and fathers rated their interaction with twin children on the Parent's Report (PR) questionnaire containing two scales-how the parent actually relates and how the ideal parent would relate. Mothers and fathers differed in parental style. Mothers perceived themselves as being profoundly more child-centered; fathers perceived themselves as using more control through arousal of guilt and anxiety. Parents asserted more control through temper and detachment with same-sex children. Boys and girls and monozygotic (MZ) and dizygotic (DZ) twins did not receive distinctly different parenting. Parents described MZ children as much more similar than DZ children but acted similarly with children in both types of twinships. Parental knowledge of zygosity did not affect the way the parents treated children. These findings suggest the relative importance of genetic contributions to behavioral similarity in MZ twins.

Fathers' and mothers' perceptions of children's personality.

Mothers and fathers rated the personality of twin children, using the Childhood Personality Scale (CPS). Fathers characterized children as less attentive, zestful, and talkative than mothers. Boys were rated as more attentive, hyperactive, ebullient and sociable; girls were described as more placid and talkative. Monozygotic (MZ) twinships were much more similar than dizygotic (DZ) on the attention, behavior modulation, and sociability dimensions. Monozygotic and DZ twins both had a high degree of intrapair similarity in zestfulness and verbal expressiveness. Monozygotic twins whose parents thought they were DZ or were not certain of zygosity were as alike as MZ twins believed to be MZ. All three MZ groups were different from DZ twins. Thus, parental expectation did not appear to strongly influence similarity in attention, behavior modulation, and sociability, This suggests the strong genetic contribution to their emergence.

Reliably separating identical from fraternal twins.

Blood typing is the most reliable method for assigning zygosity to twinships in psychological research. Cost, ethical considerations, and practical difficulties in obtaining blood specimens from a large group of children suggested the need for a questionnaire method used with young children and completed by parents. One was designed to assess zygosity based on the extent to which the children were rated as looking alike and being confused by family and strangers. Validity was determined with a sample of twins whose zygosity was demonstrated by blood typing. To determine test-retest reliability, and to explore parental beliefs about zygosity, mothers of same-sex twinships completed the questionnaire on two separate occasions, showing very high agreement. The major difference in parental perceptions of monozygotic and dizygotic twinships is convenient for epidemiological research. This difference, however, questions the assumption, made in estimates of heritability using twin data, that both twinships have identical environmental experiences.

Pilot study for comparison of reticulocyte-micronulei with lymphocyte-micronuclei in human biomonitoring.

Biomonitoring tries to determine the consequences for humans of exposures to environmental or pharmaceutical agents. Different end points have been employed to assess the burden of genomic damage. This is the first report comparing a recently introduced new end point, the reticulocyte-micronuclei analyzed by flow cytometry with the widely used lymphocyte-micronucleus assay, applied to two exposure scenarios leading to enhanced genomic damage. Radioiodine therapy was chosen to represent a short time exposure and hemodialysis treatment in end-stage renal failure was chosen to represent a chronic exposure. The results show that iodine radiation induced measurable genomic damage in the lymphocyte-micronucleus assay as well as in the reticulocyte-micronucleus test. Of two groups of patients under hemodialysis treatment, a reduced genomic damage was found with the lymphocyte-micronucleus test, but not with the reticulocyte-micronucleus test in the group undergoing daily hemodialysis, which removes uremic toxins more efficiently as compared to conventional hemodialysis, the treatment applied in the other group. The limited life-span of reticulocytes may make them less suitable for accumulation of chronic low level damage than lymphocytes. In conclusion, the lymphocyte-micronucleus test may be applicable to more exposure situations (including low chronic exposure), but the reticulocyte-micronucleus assay may be easier to perform in a clinical setting. The latter reflects a more rapid reduction of genomic damage after an acute exposure.

A novel micronucleus in vitro assay utilizing human hematopoietic stem cells.

The induction of micronucleated reticulocytes in the bone marrow is a sensitive indicator of chromosomal damage. Therefore, the micronucleus assay in rodents is widely used in genotoxicity and carcinogenicity testing. A test system based on cultured human primary cells could potentially provide better prediction compared to animal tests, increasing patient safety while also implementing the 3Rs principle, i.e. replace, reduce and refine. Hereby, we describe the development of an in vitro micronucleus assay based on animal-free ex vivo culture of human red blood cells from hematopoietic stem cells. To validate the method, five clastogens with direct action, three clastogens requiring metabolic activation, four aneugenic and three non-genotoxic compounds have been tested. Also, different metabolic systems have been applied. Flow cytometry was used for detection and enumeration of micronuclei. Altogether, the results were in agreement with the published data and indicated that a sensitive and cost effective in vitro assay to assess genotoxicity with a potential to high-throughput screening has been developed.

Modulation of beta-cell activity and its influence on islet cell antibody (ICA) and islet cell surface antibody (ICSA) reactivity.

Insulin-dependent diabetes mellitus (IDDM) is associated with the formation of autoantibodies against different antigens in the islets of Langerhans, so-called islet cell antibodies (ICA). The expression of a major autoantigen, the beta-cell specific enzyme glutamic acid decarboxylase (GAD), is glucose-dependent in vitro and correlated to insulin release in vitro. In this study the expression of islet autoantigens was examined in vivo and the relationship between beta-cell function and islet cell surface antibody (ICSA) reactivity was tested. Rats were fed for 10 days with glipizide or diazoxide, in order to stimulate or inhibit insulin release, respectively. Frozen sections of pancreata were incubated with ten ICA-positive IDDM sera and analyzed by indirect immunofluorescence. Two sera with a "beta-cell restricted" staining, five with an "all-islet cell" staining and three with a "mixed" pattern were employed. In all three groups, the highest end-point titres were obtained when pancreata of rats treated with glipizide were used. Intermediate titres were seen in control animals and the lowest titres were observed on pancreata from diazoxide-treated rats, regardless of the serum used. In contrast to these observations, no correlation between ICSA reactivity and islet cell activity could be demonstrated. Conflicting results concerning ICSA in previous reports and our failure to show a glucose regulation of ICSA reactivity, indicate that ICSA is a phenomenon with a low degree of specificity.(ABSTRACT TRUNCATED AT 250 WORDS)

Cocaine-related sudden cardiac death: a hypothesis correlating basic science and clinical observations.

Sudden, unexpected death due to cocaine in young otherwise healthy individuals occurs in an idiosyncratic manner and is commonly felt to be arrhythmogenic in nature, although the exact cause of death is rarely documented. In addition to indirect sympathomimetic actions, cocaine is a potent sodium channel blocking drug and, in this regard, most closely resembles agents such as flecainide. We suggest that sudden death due to cocaine is proarrhythmic in nature, occurring under similar circumstances as that due to specific antiarrhythmic drugs.

Human cytogenetic biomonitoring using flow-cytometric analysis of micronuclei in transferrin-positive immature peripheral blood reticulocytes.

We have developed a method to isolate and analyze nascent human reticulocytes in peripheral blood for the presence of micronuclei (MN). For a very short time peripheral reticulocytes show residual expression of the transferrin receptor. Using immunomagnetic separation of cells expressing the transferrin receptor, a population of immature reticulocytes (Trf-Ret) was isolated from peripheral blood. In humans, the spleen actively removes micronucleated erythrocytes but during the short lifetime of the isolated Trf-Ret only a fraction (less than about 20%) of the MN-containing reticulocytes will have been eliminated. Cells were stained with the fluorescent dyes Thiazole Orange for RNA and Hoechst 33342 for DNA and analyzed by flow cytometry and fluorescence microscopy. Baseline frequencies of MN-Trf-Ret on a group of healthy donors were found to be 1.1% for males and 1.4% for females; however, the gender difference was not significant. The frequency of MN-Trf-Ret in the studied group increased with age, and was dependent on blood group. In three donors studied over 4 months, the baseline level remained stable. In cancer patients treated with radiation or chemotherapy, the frequency of MN-Trf-Ret increased 10- to 20-fold after 1-4 days, depending on the treatment. A high correlation between flow and manual analysis of MN-Trf-Ret was seen. We believe the method has a high potential as a sensitive and rapid method for biological monitoring in presumed exposed groups and individuals.

Reversal of the electrocardiographic effects of cocaine by lidocaine. Part 2. Concentration-effect relationships.

Ventricular arrhythmias due to cocaine may be related to its ability to slow ventricular conduction or prolong repolarization. We previously showed that lidocaine reversed QRS prolongation due to cocaine. The purposes of these experiments were to characterize cocaine's concentration-effect relationship on both ventricular conduction and repolarization, and to determine the effects of lidocaine on these relationships. The effects of lidocaine on cocaine-induced electrocardiographic changes were studied in 20 isolated, Tyrode-perfused guinea pig hearts. Variables at cocaine concentrations ranging from 3-195 microM were measured and repeated in the presence of a fixed concentration of lidocaine 30 microM. Using nonlinear regression analysis, the sigmoid Emax and simple Emax models were fit to cocaine concentration versus percentage change in QRS plots. Measures of best fit indicated that this relationship was best described by the sigmoid Emax model. Compared with cocaine alone, the curve for cocaine with lidocaine showed a greater EC50 (concentration at 50% of maximum effect) (59 vs 100 microM) but similar Emax (371 vs 367%), consistent with competition. Similar values were obtained from the linear transformation of the data. Cocaine concentration versus percentage change in the JTc interval showed a biphasic effect: concentrations below 65 microM prolonged JTc, but those above 65 microM had no effect or decreased JTc. In contrast to changes in QRS, addition of lidocaine increased the effects of cocaine on JTc: area under the concentration-effect curve for cocaine alone was 720 versus 859 microM% for cocaine with lidocaine. Lidocaine reverses cocaine-induced slowed ventricular conduction through competition for binding, but it appeared to increase cocaine-induced prolongation of repolarization.(ABSTRACT TRUNCATED AT 250 WORDS)

Reversal of the electrocardiographic effects of cocaine by lidocaine. Part 1. Comparison with sodium bicarbonate and quinidine.

Based on modulated receptor concepts, an agent with fast on-off sodium channel binding properties (e.g., lidocaine) may reverse the effects of a drug with slow on-off kinetics (e.g., cocaine) through competition for a single receptor site on the sodium channel. We compared the effects of two drugs with different sodium channel-binding kinetics with those of sodium bicarbonate, a known antidote, on cocaine-induced slowing of ventricular conduction. Electrocardiographic (ECG) intervals were recorded before and after the addition of cocaine 30 microM in 26 isolated, Tyrode-perfused guinea pig hearts. The effects of the three potential antidotes were then analyzed: equimolar lidocaine (8 hearts), equimolar quinidine (6), and sodium bicarbonate (8). Cocaine significantly increased all ECG intervals. The addition of lidocaine to cocaine-containing perfusate decreased QRS duration from 42 +/- 3 to 29 +/- 3 msec (p < 0.01), a 60% reversal. Addition of sodium bicarbonate to increase the pH of the perfusate from 7.37 +/- 0.09 to 7.52 +/- 0.08 (p < 0.01) decreased the QRS duration from 38 +/- 4 to 30 +/- 6 msec (p < 0.01), a 47% reversal. Addition of quinidine 30 microM augmented the effects of cocaine: QRS increased from 40 +/- 6 msec to 54 +/- 9 msec (p < 0.01). Consistent with modulated receptor concepts, lidocaine reverses slowed ventricular conduction due to cocaine. The magnitude of this reversal is similar to that due to sodium bicarbonate. The potential of fast on-off agents to serve as antidotes for cocaine-induced arrhythmias requires further study.

Flow cytometric analysis of micronucleus induction in mouse erythrocytes by gamma-irradiation at very low dose-rates.

Male CBA-S mice were subjected to protracted gamma-irradiation. Two groups of five animals were each exposed to dose rates of 6 and 30 mGy/day for 56 days, respectively, upon which irradiation was terminated and the groups were followed for an additional 49 days. Frequencies of micronucleated poly- and normochromatic erythrocytes in peripheral blood samples were determined before (day 0), during (day 14, 28 and 56), and after (day 70 and 105) irradiation using flow cytometry. A second experiment was performed as above, but with exposure limited to 7 days. Frequencies of micronucleated polychromatic erythrocytes in bone marrow and peripheral blood were determined. Significantly elevated frequencies of micronuclei in peripheral blood polychromatic erythrocytes were found for the 30-mGy/day dose group on day 14, 28 and 56 and for the 6-mGy/day dose group on day 28 and 56. In normochromatic erythrocytes from peripheral blood significantly elevated frequencies were found on all sampling occasions with mouse given 30 mGy/day, while those given 6 mGy/day showed significantly elevated frequencies on day 28, 56 and 70. The frequencies of micronucleated polychromatic erythrocytes were found to be similar in bone marrow and peripheral blood, while the frequencies of micronucleated normochromatic erythrocytes were consistently lower than for micronucleated polychromatic erythrocytes at all samplings for all groups. On day 28 the frequencies (mean +/- SE) of micronucleated polychromatic erythrocytes in peripheral blood were 0.0016 +/- 0.0001 for the control group, 0.0019 +/- 0.0001 for the 6-mGy/day group and 0.0028 +/- 0.0003 for the 30-mGy/day group. The results show an elevated induction of micronuclei in erythroblasts at a dose rate of approximately 3 mGy per cell cycle.

Effects of extended low-dose-rate exposure to 137Cs detected by flow-cytometric enumeration of micronucleated erythrocytes in mouse peripheral blood.

An automated variant the of micronucleus assay for erythrocytes in mouse peripheral blood has recently been developed. The flow-cytometric technique used allows very large numbers of erythrocytes to be analysed with a relatively small effort. Here we report the potential of this method to detect a response to extended low-dose-rate exposure to gamma-irradiation. The mice were irradiated with a 137Cs source at a dose rate of 4.8 cGy/day for 26 days. Sampling was continued for another 39 days after irradiation. Elevated frequencies compared with the control group were found at days 2, 9 and 20 after the start of the irradiation for micronucleated polychromatic erythrocytes, and at days 9, 20, 29, 42, 51 and 65 for micronucleated normochromatic erythrocytes.

Flow cytometric analysis of micronucleus induction in mice by internal exposure to 137Cs at very low dose rates.

Internal radiation from 137Cs, intraperitoneally injected into mice, induced chromosome damage seen as micronuclei in erythrocytes of peripheral blood harvested 72 h after injection and analysed with flow cytometry. The retention of injected 137Cs activity was determined and the absorbed doses obtained from the beta-radiation of 137Cs were calculated for the whole bodies and bone marrow of the treated mice. The absorbed doses during the most relevant period for micronucleus induction were 2.7-18.3 mGy per day. The dose to the bone marrow during the same period was calculated to be 6-44 mGy per day. A linear dose response relationship was found.

Absence of genomic instability in mice following prenatal low dose-rate gamma-irradiation.

PURPOSE: To determine whether mice exposed to an extended low dose of gamma-irradiation during most of their prenatal period express increased frequencies of micronucleated polychromatic erythrocytes (fMPCE) and/or micronucleated normochromatic erythrocytes (fMNCE) several weeks after the end of irradiation. METHODS: Female CBA/Ca mice were gamma-irradiated for an average of 16 days during their pregnancy. The mice were exposed to dose rates of 0, 44, 99 and 265 mGy/day. At 1-2 days prior to parturition the mice were removed from exposure. Then, 36 days after birth, peripheral blood was drawn from all offspring (74 mice). Using flow-cytometer-based analysis, the frequencies of MPCE and MNCE were determined. From each animal about 170,000 PCE were analysed. RESULTS: No delayed effects in terms of higher fMPCE or fMNCE were observed among the in utero exposed mice of either gender. On the contrary, a significant (p<0.001) reduction of fMPCE was found among the male offspring exposed at the highest dose rate. CONCLUSION: Gamma-irradiation of mice during their prenatal stage did not induce damage in erythroid stem cells that can be detected as persistent or delayed chromosome aberrations (i.e. micronucleated erythrocytes) at 35 days after the end of exposure.

Differential particle uptake by larvae of three mosquito species (Diptera: Culicidae).

Second and fourth instars of Culex quinquefasciatus Say and Aedes aegypti (L.) and fourth instars of Culiseta morsitans (Theobald) were fed five size classes of latex particles ranging from 0.56 to 5.75 microns. Each experimental run was done on two size classes of particles mixed in different proportions of 10:90, 50:50, and 90:10. Both the gut contents and the food mixtures were analyzed by flow cytometry, and the particle percentage composition was determined. The null hypothesis that no particle selection existed among instars or species was rejected for all species. Small instars ingested disproportionally more large particles in all suspensions. Cs. morsitans and Cx. quinquefasciatus showed variability in their responses. Ae. aegypti almost always ingested more of the larger particles. Differences in particle size selection were related to head morphology and feeding mode. Under experimental conditions, two parameters influenced particle size selection: the relative amount of small particles offered and the size difference between small and large particles. Flow cytometry analyses are recommended for quantitative studies of field material.

The micronucleus test in rat erythrocytes from bone marrow, spleen and peripheral blood: the response to low doses of ionizing radiation, cyclophosphamide and vincristine determined by flow cytometry.

The frequency of micronucleated polychromatic erythrocytes (fMPCE) was determined in samples from bone marrow, spleen and peripheral blood of rats exposed to low doses of X-rays, cyclophosphamide or vincristine. The fMPCE values were lower in the peripheral blood than in bone marrow or spleen. This is due to the elimination of MPCE from the circulating blood, which was confirmed by the results from prolonged exposure of rats to gamma-radiation. When the analysis was restricted to the youngest PCE in peripheral blood, the sensitivity of the assay was considerably improved. This can be reproducibly achieved with the flow cytometric analysis.

Erythropoiesis and the induction of micronuclei in mouse spleen determined by flow cytometry.

Erythrocytes from the spleen of CBA mice have been prepared for analyses by flow cytometry. About 80% of the polychromatic erythrocytes (PCE) in the spleen originate from erythropoiesis in the spleen, while the remaining 20% come from the peripheral blood. Analyses of the RNA content of PCE revealed that splenic PCE do not mature into normochromatic erythrocytes (NCE) in the spleen but leave the organ at a more immature stage. A considerable part of the PCE from bone marrow also mature into NCE in the bone marrow. The rate of RNA breakdown in PCE follows an exponential function. Time-courses for the appearance of micronucleated PCE (MPCE) from spleen and from bone marrow were determined by analysis of samples taken with short intervals after an acute dose of 0.1 Gy X-rays. The time-courses were identical for MPCE from the spleen and the bone marrow. The frequency of MPCE (fMPCE) starts to increase at about 10 h after irradiation and reaches its maximum after about another 20 h upon which fMPCE returns to control level. The first induced MPCE in peripheral blood appear at about 20 h after irradiation. The effects of the carcinogen DMBA, 9,10-dimethyl-1,2-benzanthracene, at low doses were determined in PCE from spleen and bone marrow. The sensitivity was found to be about the same for erythroblasts in the spleen and the bone marrow. Protracted exposure to gamma-irradiation at a very low dose rate (44 mGy/day) gave a similar increase of fMPCE in bone marrow and spleen. The suitability of using splenic erythrocytes in the micronucleus test is discussed.

The time-course of micronucleated polychromatic erythrocytes in mouse bone marrow and peripheral blood.

The time-course of micronucleated polychromatic erythrocytes (MPCE) in mouse bone marrow and peripheral blood, induced by an acute 0.1 Gy dose of X-rays, was determined using flow cytometric analysis, which made frequent sampling possible and allowed use of a dose low enough not to affect erythroid cell proliferation. The frequency of MPCE (fMPCE) began to increase in the bone marrow at 10 h after irradiation and reached a maximum at 28 h after irradiation. In the peripheral blood fMPCE began to increase at 20 h after irradiation and peaked at about 40 h after irradiation. The time-course found is discussed on the basis of data on the differentiation of erythroid cells. The results indicate that the micronuclei registered in polychromatic erythrocytes may originate from lesions induced not only during the last cell cycle but also during earlier ones. After an acute dose of 1.0 Gy of X-rays the maximum fMPCE was delayed both in bone marrow and peripheral blood reflecting an effect on the cell cycle progression of erythroblasts.