Is accommodation a confounder in pupillometry research?

Much psychological research uses pupil diameter measurements to investigate the cognitive and emotional effects of visual stimuli. A potential problem is that accommodating at a nearby point causes the pupil to constrict. This study examined to what extent accommodation is a confounder in pupillometry research. Participants solved multiplication problems at different distances (Experiment 1) and looked at line drawings with different monocular depth cues (Experiment 2) while their pupil diameter, refraction, and vergence angle were recorded using a photorefractor. Experiment 1 showed that the pupils dilated while performing the multiplications, for all presentation distances. Pupillary constriction due to accommodation was not strong enough to override pupil dilation due to cognitive load. Experiment 2 showed that monocular depth cues caused a small shift in refraction in the expected direction. We conclude that, for the young student sample we used, pupil diameter measurements are not substantially affected by accommodation.

New serum tumor markers S100, TFF3 and AIF-1 and their possible use in oncogynecology.

OBJECTIVE: To review a literature about possible new blood serum gynecologic tumor markers, S100 proteins family, trefoil factor 3 and AIF-1. DESIGN: Literature review. SETTING: Department of Obstetrics and Gynecology, Faculty of Medicine, Palacky University and University Hospital in Olomouc. METHODS: Literature review of articles published in PubMed database till January 2019. RESULTS: The association of S100A2, S100A4, S100A6, S100A7, S100A8, S100A9 and S100A11 with breast carcinoma has been demonstrated in the literature. The association of S100A2, S100A4, S100A6, S100A7A, S100A10, S100A14, S100A16, S100B, S100P (up-regulation associated with a lower survival) and S100A1, S100A13, S100A5, S100A13 and S100G proteins (up-regulation associated with a better survival) have been demonstrated in ovarian cancer patients. Cervical carcinoma has been shown to be associated with the S100A9 protein. TFF3 association with endometrial cancer, breast cancer (worse prognosis) and ovarian cancer (better prognosis) has been demonstrated. AIF-1 has been shown to increase expression in cervical cancer. CONCLUSION: Tumor markers can be a very useful tool for patient management when used appropriately. Further research in this area and the search for new tumor markers, including S100, TFF3 and AIF-1, are needed. In future studies, scientists should focus not only on one time point, but assess the trend of the tumor markers for a specific time axis.

[Elevated levels of TFF3 in endometrial cancer patients]. / Zvýsení hladin TFF3 u zen s karcinomem endometria.

AIM: Trefoil peptides are a family of small proteins that are expressed in a site-specific fashion by certain epithelial tissues. These peptides might be used as markers for neoplastic uterine disease. DESIGN: Experimental study. SETTING: Department of Obstetrics and Gynaecology, University Hospital, Medical Faculty, Palacký University, Olomouc; Department of Laboratory Biochemistry, Central Moravian Hospital Trust, Member of Agel holding, Prostejov. METHODS: During the time period from 2012 to 2015 eighty-nine women underwent hysteroscopy and endometrial biopsy for postmenopausal bleeding. Fifty three patients, at the age of (mean ± standard deviation) 63,4 ± 9,5 (33-80) years were diagnosed with endometrial cancer, six patients at the age of 62,9 ± 6,4 (55-74) years were diagnosed with endometrial hyperplasia and thirty patients at the age of 63,3 ± 9,3 (48-62) years diagnosed with endometrial atrophy represented control group. At the day of surgery the venous blood was sampled and subsequently examined for the levels of TFF1, TFF2 and TFF3. RESULTS: TFF3 levels were significantly higher in patients with endometrial carcinoma but not in endometrial hyperplasia subgroup. The levels of TFF1 and TFF2 were not different in selected histopathological subgroups. CONCLUSION: We have shown elevated levels of TFF3 but not of TFF1 and TFF2 in patients with endometrial cancer. TFF1, TFF2 and TFF3 levels were not elevated in patients with endometrial hyperplasia.

Laparoscopic and robotic sacropexy: retrospective review of learning curve experiences and follow-up.

OBJECTIVE: To compare conventional laparoscopic (LSC) and robotic (RSC) sacrocolpopexy in the treatment of apical pelvic prolapse during robotic surgery "learning curve". Operative characteristics, prolapse treatment outcomes, and postoperative results were assessed. DESIGN: Retrospective comparative study. SETTING: Department of Obstetrics and Gynecology, University Hospital and Palacky University, Olomouc. METHODS: We analyzed consecutive 51 patients treated with laparoscopic sacropexy and 13 women operated with robotic system. Data on patient age, body mass index (BMI), operation history, estimated blood loss, operation time, surgical outcomes (including pelvic organ prolapse quantification - POP-Q), and concomitant surgeries were retrospectively obtained from patient medical records. Subjective outcomes were measured through PGI-I and PISQ-IR questionaires when available at last follow up (n = 26). RESULTS: In both groups all procedures were performed correctly without conversion. The mean operative time was longer in robotic group: 212 (128-394) min, as compared to 164 (80-342) in the laparoscopic group. Blood loss was lower for the robotic 52 (10-200) ml compared to laparoscopic group 58 (10-350) ml. Differences in operative time and blood loss were not statistically significant. Differences between LSC and RSC groups in postoperative results were not statistically significant. Learning curve for robotic sacrocolpopexy was shorter than for laparoscopic procedure in case of experienced laparoscopic surgeons. No recurrences occurred during follow-up. Most patients were satisfied with surgical results. CONCLUSION: The present study demonstrated that RSC may be comparable in surgical safety and efficacy. The decision regarding the best surgical approach has to be individualised according to the characteristics of the patient and their preferences as well as the local clinical setting and the surgical expertise of physicians.

[The role of trefoil factor family in gynecological disease]. / Význam trifolátu u gynekologických onemocnení.

AIM: Trefoil peptides are a family of small proteins that are expressed in a site-specific fashion by certain epithelial tissues. These peptides appear to be important in mucosal healing processes, in neoplastic disease and in human reproduction. DESIGN: Literature review. SETTING: Department of Obstetrics and Gynaecology, University Hospital, Medical Faculty, Palacký University, Olomouc, Czech Republic; Department of Laboratory Biochemistry, Central Moravian Hospital Trust, Member of Agel holding, Prostejov. METHODS: Literature review. RESULTS: Trefoil peptides are aberrantly expressed by a wide range of human carcinomas and gastrointestinal inflammatory conditions. Outside the gastrointestinal tract, members of this group of peptides have also been identified in the normal hypothalamus and pituitary, and in normal breast tissue where it is responsive to oestrogen stimulation. Evidence of peptide expression has been found in a range of urological, gynaecological, gastrointestinal, pulmonary and breast carcinomas. Furthermore, possible associations between recurrent spontaneous abortion susceptibility and genetic varia-tion in the TFF3 gene were shown.Conclusion In the future, serum levels of trefoil peptides might be used as markers for neoplastic and inflammatory diseases, as well as some defects of reproduction.

[Robotic sacrocolpopexy - two case reports and literature overview]. / Robotická sakrokolpopexe - dve kazuistiky a literární prehled.

OBJECTIVE: To describe first two cases of robotic sacrocolpopexy in the Czech Republic. DESIGN: Two case reports with literature overview. SETTING: Department of Obstetrics and Gynaecology, Faculty of Medicine and Dentistry, Palacky University in Olomouc. CASE REPORT: Robotic sacrocolpopexy was performed in two patients of the age 36 and 59 at the department of obstetrics and gynecology in Olomouc in 2009. We describe vaginal prolapse treatment in one case, and supracervical hysterectomy with cervicosacropexy in the other. These two cases are compared with literature overview, including long-term follow-up. CONCLUSION: Robotic sacrocolpopexy encompasses all advantages of minimally invasive surgery. Our results, as well as published data show very good long term results of vaginal prolapse treatment using this approach.

["Learning curve" robotic radical hysterectomy compared to standardized laparoscopy assisted radical vaginal and open radical hysterectomy]. / Robotem asistovaná radikální hysterektomie ve fázi "learning curve" a její srovnání se standardní laparoskopicky asistovanou radikální vaginální a otevrenou radikální hysterektomií

OBJECTIVE: To compare intraoperative, pathologic and postoperative outcomes of "learning curve" robotic radical hysterectomy (RRH) with laparoscopy assisted radical vaginal hysterectomy (LARVH) and abdominal radical hysterectomy (ARH) in patients with early stage cervical carcinoma. DESIGN: Comparative study. SETTING: Department of Obstetrics and Gynecology, University Hospital, Olomouc. METHODS: The first twenty patients with cervical cancer stages IA2-IIA underwent RRH and were compared with previous twenty LARVH and ARH cases. The procedures were performed at University Hospital Olomouc, Czech Republic between 2004 and 2011. RESULTS: There were no differences between groups for age, body mass index, tumor histology, number of nodes removed or preoperative hemoglobin levels. The median theatre time in the learning period for the robot procedure was reduced from 400 min to less than 223 min and compared well to the 215 min for an open procedure. We found differences between the pre- and postoperative hemoglobin levels (RRH, 14.9 ±7 .6; LARVH, 23.0 ± 8.5; ARH, 28.0 ± 12.4). This difference was statistically significant in favor of RRH group ( p= 0.0012). Mean length of stay was significantly shorter for the RRH group (7.2 versus 8.8 days,p = 0.0005). Mean pelvic lymph node count was similar in the three groups. None of the robotic or laparoscopic procedures required conversion to laparotomy. The differences in major operative complications between the two groups were not significant. CONCLUSION: Based on our experience, robotic radical hysterectomy showed better results than traditional laparoscopically assisted radical vaginal hysterectomy in early stage cervical carcinoma cases. Introduction of this new technique requires a learning curve of less than 20 cases that will reduce the operating time to a level comparable to open surger.

High-dose chemotherapy with autologous stem cell rescue in children with retinoblastoma.

Children with metastatic retinoblastoma are considered to have a poor prognosis after conventional chemotherapy. We used high-dose chemotherapy (HDC) with peripheral hematopoietic stem cell transplantation in such patients in an attempt to improve their survival. Four patients with bone marrow metastases and one child with extraorbital disease were treated with HDC after achieving complete remission by enucleation and conventional chemotherapy. The child with extraorbital tumor was the only one to receive local irradiation. The conditioning regimen included thiotepa (900 mg/m(2)), etoposide (40 mg/kg) and carboplatin (1.5 g/m(2)) in four patients, and BCNU (300 mg/m(2)), cyclophosphamide (6.8 g/m(2)) and etoposide (1.6 g/m(2)) in one child. Hematologic recovery occurred without delay in all patients. The main toxicities were diarrhea, mucositis and infectious complications. No toxic deaths or any major late toxicities were observed. The child treated with the BCNU regimen developed a meningeal relapse 10 months after HDC, which was partially resected and treated with conventional chemotherapy, but not with radiotherapy. He is in complete remission (CR) 105 months off treatment. The other patients are in CCR for 107, 57, 9 and 8 months after HDC. HDC with thiotepa, etoposide and carboplatin may represent a curative option for children with extrabulbar or disseminated retinoblastoma responsive to chemotherapy. It may control occult CNS disease. The necessity to irradiate these children and the curative potential of this strategy for patients with bulky CNS disease remain to be determined.

Feasibility of human trials to assess developmental immunotoxicity, and some comparison with data on New World monkeys.

Procedures to reveal 'immunotoxic' potentials of chemicals in animal experiments (mostly in rodents) have been recommended, but the selection of test systems is rather arbitrary. The predictive power of extrapolations to the possible situation in humans is unknown because human studies to confirm or to reject clues from animal data are largely lacking. End points selected in animal studies and those expected to be relevant in humans are not identical. Results of animal experiments are based on doses, generally ignoring the important species differences in pharmacokinetics. This unfavorable situation is especially pronounced when attempting to evaluate 'environmental chemicals'. Because much more information is available on many medicinal drugs, exposures can be defined and pharmacokinetic data are available or obtainable. The situation is even more complicated when attempting to assess possible adverse effects on the developing immune system: in addition to the problems mentioned, numerous different developmental periods with varying susceptibilities must be considered, and species differences in the immune response are superimposed with large differences in pre-, early post-, and later postnatal development. Simultaneously, the kinetic variables are continuously changing with time (with additional variability among species). Different results, even between rats and mice, are bound to occur. Extrapolation to the situation possibly relevant for human exposure will be almost impossible, especially from rodent data. The majority of such effects induced peri- or early postnatally may be expected to be reversible. It must also be assessed whether qualitatively different adverse effects are likely to be induced during 'development', which cannot be revealed (accepting quantitative differences) by more easily performed tests on the adult organism. Considering the intrinsic difficulties, the most promising approach would be to directly obtain data from human trials. This is feasible for medicinal drugs. Alternatively, data on nonhuman primates, the species phylogenetically closest to man, may provide useful information. The status quo for such a strategy and the possible pitfalls are discussed in this overview.

Potential teratogenicity of di-n-butyltin dichloride and other dibutyltin compounds.

The developmental toxicity of di-n-butyltin dichloride (DBT-dC) was evaluated in Wistar rats following oral administration. No maternal toxicity, embryotoxicity, or malformations were observed at 1, 2.5, or 5 mg DBT-dC/kg body weight. Signs of maternal toxicity, including decreased food consumption, body weight gain, and thymus weight, were observed at 10 mg/kg body weight DBT-dC. At this dose, no evidence of embryotoxicity, including such measures as total resorptions, viable fetuses, or fetal weights, was noted in any litter data. There was a slightly increased frequency of total malformations at the 10 mg/kg dose level of 4/262 treated vs. 1/269 control fetuses. All defects occurred singly with no clustering nor organ system pattern of occurrence, which would be indicative of a teratogenic effect. The no-observed-adverse-effect-level (NOAEL) for prenatal as well as maternal toxicity was considered to be 5 mg DBT-dC/kg body weight. The interpretation and utility of previously published studies on the developmental toxicity of dibutyltin compounds are confounded by dose regimen and data reporting deficiencies. These studies suggest that, after oral administration during days 6-17 of pregnancy, the NOAEL for malformations in rats of different strains ranges from 1.7 to 5 mg/kg body weight. In these studies, the maternal LD50 was reported to be about 8 mg/kg body weight in one study but at greater than 15 mg/kg in others. Thus, the NOAEL for teratogenicity may be roughly estimated to be from one-tenth to one-third of the maternal LD50. When evaluated, thymus involution, a typical but reversible effect of di- and tri-butyltin compounds, was also observed at 5-10 mg/kg body weight. The most susceptible time for inducing teratogenic effects is reported to be days 7-9 of pregnancy, but malformations have also been found with dosing over longer duration at lower doses. It is doubtful that the findings of malformations at highly toxic doses in animals has any health hazard significance, especially when human exposure to dibutyltins typically occurs at several orders of magnitude lower than the doses used in these studies. Further comparative pharmacokinetic studies would be necessary in order to refine the hazard characterization.

Multicenter field trial on possible health effects of toluene. I. Toluene body burdens in workers of the rotogravure industry.

Ambient air toluene concentrations as well as corresponding individual blood toluene levels were measured under conditions of a field trial, as basis for a correlation with possible acute effects. While the results of various psycho-physiological and medical evaluations after acute (Neubert et al., 2001) and long-term toluene exposure (Gericke et al., 2001) are published in accompanying papers, this publication deals with the exposure levels and body burdens characteristic of workers in the rotogravure industry in Germany at the time of the investigation (1993-1995). Besides providing some information on the exposure at various work-areas under occupational conditions, the correlation between a time-weighted average of the ambient air concentration with the corresponding blood toluene levels is analyzed. Limitations of such an attempt and possible pitfalls are discussed. In the largest field study so far performed on toluene exposure, 12 companies of the German rotogravure industry (and a total of 1528 volunteers) participated. Altogether, complete data sets, i.e. on both ambient air as well as blood toluene levels, were obtained from 1244 male and 124 female participants of the rotogravure industry with quite different degrees of toluene exposure. Rotogravure printers and their helpers were exposed to the highest toluene concentrations in ambient air. On the day of the evaluation, of 806 male volunteers within this group (of 1261 with verified exposure in air), 35 were exposed to a time-weighted average of 100 ppm (i.e. 375 mg/m(3)) or above, and 155 of the printers to concentrations between 50 and 100 ppm. Of the remaining 455 male participants of the rotogravure factories ('non-printers and helpers'), only three were exposed to toluene concentrations above 50 ppm. Only one of the 124 women working in the rotogravure factories was exposed to an average toluene concentrations above 100 mg/m(3) (i.e. 27 ppm). In 66 of the male volunteers toluene levels in blood of >850 microg/l were measured and 14 showed levels exceeding 1700 microg/l. When attempting to predict the resulting individual blood toluene levels from measurements of ambient air concentrations under field conditions, a considerable uncertainty is to be expected. We found a correlation coefficient of the regression curve of about 0.70, with numerous outliers (and a variation of the 12 factories between 0.52 and 0.88).

Multicenter field trial on possible health effects of toluene. II. Cross-sectional evaluation of acute low-level exposure.

Data on possible acute effects of today's relevant low-level exposure to toluene are contradictory, and information on possible effects of exposure under occupational conditions is largely lacking. In a controlled, multi-center, blinded field trial, effects possibly associated with acute toluene exposure were evaluated in workers of 12 German rotogravure factories. Medical examinations (inquiries on subjective symptoms, and standard tests of psycho-physiological and psycho-motor functions) were performed on almost 1500 volunteers, of whom 1290 were toluene-exposed (1178 men and 112 women), and about 200 participants served as references (157 men and 37 women), but the main aim of the trial was to reveal dose-response relationships. All volunteers were of the morning work-shift (6 h exposure). Both individual ambient air concentrations (time-weighted average) during the work-shift, as well as blood toluene concentrations after the work-shift were measured. Therefore, the medical data could for the first time be correlated with the actual individual body burden (blood toluene level) at the time of testing. In order to largely exclude confounding by chronic toluene exposure, kinetic measurements as well as the psycho-physiological and psycho-motoric tests were performed before and after the work-shift. Except for minor statistical deviations, neither convincing dose-dependent acute effects could be demonstrated with regression analyses in male volunteers at the exposure levels evaluated, nor were significant differences found when applying group statistics (highly toluene-exposed group versus volunteers with negligible exposure). Due to the rather large number of participants, the predictive power of the study is high, especially when compared with previous publications. In two psycho-physiological tests, a few more female volunteers with quite low toluene body burdens (<340 microg/l blood) showed relatively low scores when compared with participants of the reference group. Although evidence for a medical relevance is meager, the small numbers of participants, in both the exposure and the reference groups, hamper a reliable interpretation of the results concerning exposure levels above 85 microg toluene/l blood, and it is difficult to take confounding factors adequately into account. For the end points evaluated and under occupational conditions, neither blood toluene levels of 850 to 1700 microg/l (in the highest exposure group [EXPO-IV] with 56 participants), as measured 1/2 (+/-1/2) h after the work-shift, nor ambient air concentrations (time-weighted average over 6 h) between 50 and 100 ppm (188-375 mg/m(3)) were convincingly associated with alterations in psycho-physiological and psycho-motoric performances or increased the frequency of subjective complaints in male volunteers. For higher dose ranges of toluene exposure (i.e. >1700 microg toluene/l blood [or >100 ppm in ambient air]), our data set is too small for far reaching conclusions. Our data are insufficient for conclusions on a possibly higher susceptibility to toluene of some female workers. Results of kinetic studies and possible effects of long-term exposure are discussed in two accompanying publications (Neubert et al., 2001; Gericke et al., 2001).

Multicenter field trial on possible health effects of toluene. III. Evaluation of effects after long-term exposure.

In rotogravure industry, contributing considerably to mass color printing of catalogues and magazines, toluene is still extensively used as paint solvent, and many printers have been exposed to this chemical for several decades. Information on adverse health effects associated with long-term toluene exposure is still controversial. In a multi-center study, adverse health effects possibly associated with long-term toluene exposure were evaluated. In 12 rotogravure factories, 1226 male volunteers were recruited, and sufficient information on exposure and on medical data was compiled for about 1077 of them. Evaluations included: physical examination, standard tests of psycho-physiological and psycho-motoric performances, self-report of subjective symptoms, and data on a variety of laboratory blood tests. The medical data were correlated with the length (months) of toluene exposure, and a rough estimate of the extent of exposure (i.e. highly exposed printers and their helpers versus employees working at locations with low or negligible toluene exposure). A small reference group (n=109) was selected from companies of the paper industry. When linear regression curves were calculated (test results versus duration of exposure), extremely low overall coefficients of determination (r(2) adj.) of a few percent were estimated within the data clouds, with sometimes statistically significant P-values. Closer analyses revealed a strong influence of the confounding factor age, no clustering of abnormal values of highly toluene-exposed volunteers, and the vast majority or all values of the highly and long-term toluene-exposed participants staying within the reference ranges. Thus, no medical relevance of P-values <0.05 could be recognized in this evaluation, and there may have been some border-line deviations or results largely occurring by chance in the large trial. In a small cluster of the many rotogravure printers toluene-exposed for more than 20 years, the highest systolic blood pressure values of the study were found, but many possible confounding factors were not taken into account. Data on acute exposure and possible effects are presented in accompanying papers (Neubert et al., 2001a, Neubert et al., 2001b). Restricting the conclusions to the end points evaluated as well as the apparent limitations of the evaluation, no evidence was found that long-term occupational toluene exposure extending over several decades in the rotogravure industry in the Western part of Germany was convincingly associated with chronic adverse health effects or convincingly altered surrogate markers in still working male volunteers. Several peculiarities and pitfalls arising when interpreting medical data associated with such a type of environmental exposure must be considered. Reversibility of alterations previously induced at higher levels of toluene-exposure, as well as a healthy workers effect, cannot be excluded for some of the medical end points evaluated.

Kinetics and inductive potency of 1,2,3,4,6,7,8-heptachlorodibenzo-p-dioxin (H7CDD) in rats.

The kinetic properties and the inductive potency of 1,2,3,4,6,7,8-heptachlorodibenzo-p-dioxin (H7CDD) were studied in Wistar rats following subcutaneous (s.c.) injections. For assessing the dose-response, rats were treated with a single dose of 3. 10 or 30 microg H7CDD/kg body wt. Tissue concentrations and enzyme induction were measured 1, 2, and 3 weeks after treatment, and in the 30 microg/kg group additionally after 6, 20 and 57 weeks. Tissue concentrations increased dose-dependently from 3 to 30 microg/kg. Concentrations in liver were always higher than in adipose tissue, the concentration ratio: liver/adipose tissue varied between 32 and 67. The activity of (ethoxyresorufin O-deethylase) (EROD) in liver microsomes was clearly induced by H7CDD, reaching maximal induction three weeks after treatment. (3-fold at 3 microg/kg, 5-fold at 10 microg/kg and nearly 30-fold at 30 microg/kg). For assessing the time dependency, tissue levels and hepatic enzyme induction were monitored over a period of 57 weeks after a single s.c.-injection of 30 microg H7CDD/kg body wt. Hepatic concentrations of the congener remained rather constant from the 2nd to the 20th week after treatment (280 ng/g and 319 ng/g, respectively). In contrast, concentrations in adipose tissue and thymus increased 2-fold during this period, and 20 weeks after injection reached a maximum of 11 ng/g and 3 ng/g, respectively. Thereafter, the concentrations decreased and tissue levels of 91 ng/g (liver), 3 ng/g (adipose tissue) and 2 ng/g (thymus) were detected 57 weeks after treatment. The elimination half-life (t 1/2) calculated from our data was 140 days in liver and 130 days in adipose tissue. The reasonable explanation for the increase in tissue concentrations of H7CDD up to 20 weeks after treatment is the slow release of this congener from the subcutaneous injection site. Induction of hepatic EROD activity always closely followed changes in the hepatic concentrations of H7CDD, reaching a maximum 3 weeks after treatment and remaining at this level until the 20th week. Correlation analysis of hepatic H7CDD concentrations versus the extent of EROD induction indicated a linear relationship in a double-logarithmic plot. When compared with TCDD, the hepatic monooxygenase-inducing potency of H7CDD within the low dose range was found in the rat to be 170 to 440-times lower than that of TCDD. Measurement of 14C-caffeine demethylation, using a 14CO2 breath test, revealed a similar time course in vivo when compared with the microsomal EROD activity ex vivo.

Assessment of P450 induction in the marmoset monkey using targeted anti-peptide antibodies.

The identity and expression of hepatic P450 enzymes in marmosets was investigated using a panel of anti-peptide antibodies originally targeted against human P450 enzymes. In immunoblotting, of 12 antibodies examined, 10 bound specifically to bands in marmoset liver microsomal fraction corresponding to P450 enzymes. It is proposed that these represent marmoset CYP1A1, CYP1A2, CYP2A, CYP2B, CYP2C forms (CYP2C-1 and CYP2C-2), CYP2D19, CYP3A21 and another CYP3A form (CYP3A-m). The antibodies, together with an anti-marmoset CYP2E1 antibody, were used to investigate the expression of 10 P450 enzymes in marmosets treated with P450-inducing chemicals. Treatment with phenobarbitone caused CYP2B, CYP2C-2 and CYP3A21 levels to increase, rifampicin caused increases in CYP2B and CYP2C-1 and a decrease in CYP3A21 levels, whereas dioxin caused CYP1A1 and CYP1A2 levels to increase and CYP2E1 levels to decrease. Clofibric acid did not induce any P450. P450 enzyme activities were assessed using 8 different substrates and increases were found after treatment with phenobarbitone, rifampicin, and dioxin. However, due to species differences in substrate selectivity, it proved difficult to ascribe these changes to individual P450 enzymes. Thus, the use of anti-peptide antibodies provides a more informative way of assessing the levels of specific P450 enzymes than enzyme activity measurements.

Assessing lymphocyte functions in neonates for revealing abnormal prenatal development of the immune system.

Because it is difficult to assess prenatally induced functional deficits of the human immune system, we developed an ex vivo method for differentiation and maturation of peripheral lymphocytes of newborn, preferentially using umbilical cord blood. Many lymphocyte subsets of newborn infants are "immature" with respect to defined surface receptors. An example of such an immaturity is the almost complete lack of "memory"-type helper T cells (also designated as helper-inducer cells), characterized by expressing the surface receptors: CD4(+)CD45R0(+)CD45RA(-)CD29(high). On the other hand, umbilical cord blood contains many "naive"-type helper T cells (often designated as suppressor-inducer cells), with the receptors: CD4(+)CD45R0(-)CD45RA(+)CD29(low). In this report, we demonstrate that the immature helper lymphocyte population of umbilical cord blood is capable of differentiating to mature cells following stimulation with pokeweed mitogen (PWM) and other stimulants ex vivo. The obtained receptor pattern is virtually indistinguishable from the one observed on the mature cells of adults. Such an extensive differentiation can only be achieved with cells of newborns. As intermediates during differentiation in culture, CD45R0(+)CD45RA(+) cells may be observed which are rather rare in vivo. Additionally, the appearance of several activation (CD25, CD69, HLA-DR) and adhesion (CD11a, CD11b, CD11c, CD18, CD49b, CD49d, CD54) receptors on CD4 cells were analyzed. With this model system evidence for the sequence of events during differentiation and maturation may be obtained. This ex vivo-model is capable of studying the capacity of lymphocytes for differentiation and activation processes barely accessible in vivo. It may also be expected to represent an interesting tool for measuring the capacity for maturation and differentiation in the blood of children of different ages under normal and pathological conditions ex vivo. In addition, substance-induced effects may be studied in vitro with this approach on immature cells from newborn, or infants during culturing. Teratogenesis Carcinog. Mutagen. 20:171-193, 2000.

Identification of theta-class glutathione S-transferase in liver cytosol of the marmoset monkey.

The presence of theta-class glutathione S-transferase (GST) in marmoset monkey liver cytosol was investigated. An anti-peptide antibody targeted against the C-terminus of rGSTT1 reacted with a single band in marmoset liver cytosol that corresponded to a molecular weight of 28 kDa. The intensity of the immunoreactive band was not affected by treatment of marmoset monkeys with 2,3,7,8-tetrachlorodibenzo-p-dioxin, phenobarbitone, rifampicin or clofibric acid. Similarly, activity towards methyl chloride (MC) was unaffected by these treatments. However, GST activity towards 1,2-epoxy-3-(p-nitrophenoxy)-propane (EPNP) was increased in marmosets treated with phenobarbitone (2.6-fold) and rifampicin (2.6-fold), activity towards dichloromethane (DCM) was increased by 50% after treatment of marmosets with clofibric acid, and activity towards 1-chloro-2,4-dinitrobenzene (CDNB) was raised slightly (30-42% increases) after treatment with phenobarbitone, rifampicin or clofibric acid. Compared with humans, marmoset liver cytosol GST activity towards DCM was 18-fold higher, activity towards MC was 7 times higher and activity towards CDNB was 4 times higher. Further, EPNP activity was clearly detectable in marmoset liver cytosol samples, but was undetectable in human samples. Immunoreactive marmoset GST was partially purified by affinity chromatography using hexylglutathione-Sepharose and Orange A resin. The interaction of immunoreactive marmoset GST was similar to that found previously for rat and human GSTT1, suggesting that this protein is also a theta class GST. However, unlike rat GSTT1, the marmoset enzyme was not the major catalyst of EPNP conjugation. Instead, immunoreactivity was closely associated with activity towards MC. In conclusion, these results provide evidence for the presence of theta-class GST in the marmoset monkey orthologous to rGSTT1 and hGSTT1.

Chlorinated dibenzo-p-dioxins and dibenzofurans and the human immune system: 3. Plasma immunoglobulins and cytokines of workers with quantified moderately-increased body burdens.

The concentrations of immunoglobulins (IgA, IgD, IgG, IgM) and of several cytokines were measured in the plasma of volunteers with clearly, but moderately, increased body burdens of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/PCDF), using monoclonal antibodies and an enzyme-linked immuno-sorbant assay. Two groups of workers with different body burdens of PCDD/PCDF were studied: (trial I) persons with mainly 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), and (trial II) persons with mainly penta- and hexachlorinated dibenzofurans (P5CDF/H6CDF) in their blood fat. Including the reference group, 158 volunteers were investigated. A slight but statistically significant decrease was observed in the plasma concentration of IgG1 in persons exposed to TCDD, but not in persons exposed to P5CDF/H6CDF. When the data of both groups were pooled and a multi-regression analysis against international TCDD toxicity equivalencies (I-TEq, NATO/CCMS) was performed, taking several confounding factors into account, no influence of the dioxin exposure could be revealed. There were no changes in the plasma concentrations of the other immunoglobulins studied. In the same volunteers, no deviation from the reference range was found for the concentrations of the cytokines: IL-1alpha, IL-1beta, IL-6 and TNFalpha in blood plasma.