Altered enzyme activities of xenobiotic biotransformation in kidneys after subchronic administration of 3-chloro-4-(dichloromethyl)-5-hydroxy-2(5H)-furanone (MX) to rats

Activities of the xenobiotic metabolizing enzymes were measured in the liver, kidney, duodenum and lung microsomes and cytosol fractions of Wistar rats after subchronic administration of 3-chloro-4-(dichloromethyl)-5-hydroxy-2(5H)-furanone (MX), a potent bacterial mutagen in chlorinated drinking water. MX was administered by gavage at the dose level of 30 mg/kg for 18 weeks (low dose), or at the dose level which was raised gradually from 45 mg/kg for 7 weeks via 60 mg/kg for 2 weeks to a clearly toxic dose of 75 mg/kg for 5 weeks (high dose). Microsomal and cytosolic preparations were made and the activities of 7-ethoxyresorufin-O-deethylase (EROD), pentoxyresorufin-O-dealkylase (PROD), NADPH-cytochrome-c-reductase, UDP-glucuronosyltransferase (UDPGT) and glutathione-S-transferase (GST) were measured. Kidneys were affected most. A dose-dependent decrease was observed in EROD (90% in males, 80% in females at the high dose) and in PROD (58% in females, at the high dose) in kidneys. An increase was, however, detected in kidney NADPH-cytochrome-c-reductase (66% in females at high dose), UDPGT (89% in males and 97% in females at high dose) and GST activities (56% in males and 50% in females at high dose). MX caused only a few changes in the enzyme activities of the liver. The EROD activity was decreased 25% to 37%, both in the livers of males and females, but the total content of P450s was not altered. Hepatic GST activity was elevated in females in a dose-dependent manner (31% and 44%). GST activity was elevated in duodenum in females (59%) at the high dose. There were no marked changes in the enzyme activities in the lungs. MX was a weak inhibitor of EROD activity both in the liver and kidney microsomes in vitro, decreasing the EROD activity by 53% and 43%, respectively at the concentration of 0.9 mM. The results indicate that MX decreases the activity of phase I metabolism enzymes, but induces phase II conjugation enzyme activities, particularly in kidneys in vivo. It is possible that these changes contribute to metabolism of MX in kidneys and renders them susceptible to MX in the course of repeated exposure.     

Effect of linoleic acid, linoleic acid anilide, and arachidonic acid on the expression of adhesion molecules on human neutrophils

The effects of linoleic acid, linoleic acid anilide, and arachidonic acid on the expression of CD11b/CD18, CD11c/CD18 integrins and l-selectin on human neutrophils were studied by flow cytometry in a whole blood assay. None of these compounds had any effect on the basal expression of CD11b, CD11c, or l-selectin in the concentration range of 20–100 μM. However, linoleic acid at a concentration of 1000 μM slightly up-regulated CD11b and CD11c by a factor of 2.1 and 1.7, respectively. Linoleic acid, linoleic acid anilide, and arachidonic acid did not affect the formyl-methionyl-leucyl-phenylalanine induced up-regulation of CD11b or CD11c. However, linoleic acid and linoleic acid anilide slightly inhibited the phorbol myristate acetate (PMA)-induced expression of CD11b, which was decreased by 27 and 21% at concentrations of 100 and 1000 μM, respectively. Likewise, arachidonic acid at 40 μM inhibited the PMA-induced expression of CD11b by 19%. Our results suggest that linoleic acid, linoleic acid anilide, and arachidonic acid do not dramatically affect the expression of leukocyte adhesion molecules in a whole blood assay. Received: 17 February 1997  / Accepted: 5 May 1997     

p53Mutations and Presence of HPV DNA Do Not Correlate with Radiosensitivity of Gynecological Cancer Cell Lines

Objective.The correlation betweenp53tumor suppressor gene mutations and the presence of high-risk human papillomavirus (HPV) DNA with thein vitroradiosensitivity of gynecological malignancies was studied in 26 cell lines derived from gynecological cancers of 23 patients.Methods.Comparison of the intrinsic radiosensitivity was performed with mean inactivation dose (D?) determined with the 96-well plate clonogenic assay.p53mutations were investigated with polymerase chain reaction and single-strand conformation polymorphism (PCR–SSCP) analysis and direct DNA sequencing, and the presence of HPV DNA was studied with PCR using HPV consensus primers.Results. p53mutations were found in 6 of 10 vulvar squamous cell carcinoma (SCC) lines. Nine vulvar and 1 vaginal SCC cell lines were HPV DNA negative and 1 vulvar cell line was HPV 16 positive. All 4 cervical SCC lines were HPV positive and possessed the wild-typep53.Three cell lines expressed HPV 16 and 1 HPV 68. Among 10 endometrial cancer cell lines, 2 cell lines with mutantp53and 1 HPV 16 positive cell line were found. No correlation could be demonstrated between inactivation of thep53gene and radiosensitivityin vitro;the cell lines were evaluated as one group or according to their anatomical origin or histology.Conclusion.Our results indicate that inactivation of thep53gene through mutation or binding with HPV DNA does not increase the resistance of gynecological malignancies to ionizing radiationin vitro.     

Daily Life Events Influence the Results of the Dexamethasone Suppression Test in Healthy Women

Although the Dexamethasone Suppression Test (DST) plays an important role in psychosomatic research, confounding factors limit the sensitivity and specificity of the DST. The aim of this study was to investigate the relationship between the intensity of daily life stressors and DST results in healthy participants after controlling the confounding factors. The subjects of this study consisted of 75 healthy volunteers. The intensity of daily life events was assessed using the Taiwanese version of the Recent Life Change Questionnaire (RLCQ). Neuroticism was assessed using the Maudsley Personality Inventory (MPI). The Dexamethasone Suppression Test (DST) was also performed. The regression model showed that daily life events (RLCQ score) were correlated significantly with cortisol level on day 1 and D% only in women. This finding implies that daily life events should be considered as an independent variable in women in further studies when the DST is applied.     

Early Childhood Gut Microbiomes Show Strong Geographic Differences Among Subjects at High Risk for Type 1 Diabetes

OBJECTIVE

Gut microbiome dysbiosis is associated with numerous diseases, including type 1 diabetes. This pilot study determines how geographical location affects the microbiome of infants at high risk for type 1 diabetes in a population of homogenous HLA class II genotypes.

RESEARCH DESIGN AND METHODS

High-throughput 16S rRNA sequencing was performed on stool samples collected from 90 high-risk, nonautoimmune infants participating in The Environmental Determinants of Diabetes in the Young (TEDDY) study in the U.S., Germany, Sweden, and Finland.

RESULTS

Study site–specific patterns of gut colonization share characteristics across continents. Finland and Colorado have a significantly lower bacterial diversity, while Sweden and Washington state are dominated by Bifidobacterium in early life. Bacterial community diversity over time is significantly different by geographical location.

CONCLUSIONS

The microbiome of high-risk infants is associated with geographical location. Future studies aiming to identify the microbiome disease phenotype need to carefully consider the geographical origin of subjects.     

Does the use of Health Care and Special School Services, Prior to Admission for Psychiatric Inpatient Treatment, Differ Between Adolescents Housed by Child Welfare Services and Those Living with Their Biological Parent(s)?

We examined whether the use of health care and special school services, prior to admission for psychiatric inpatient treatment, differed between adolescents from child welfare units and those living at their parental home. 208 boys and 300 girls aged 12–17 years were admitted for psychiatric hospital between 2001 and 2006. Child welfare adolescents had used more health services/treatments prior to psychiatric hospital admission than adolescents living with their biological family. The best discriminating factors between study groups for both genders, were previous psychiatric hospitalizations, unemployed parents, use of special school services and self-perceived serious anxiety/tension or trouble controlling violent behavior. Repeated school grades and previous use of psychotropic medications were discriminating factors only in girls. Adolescents in child welfare deserve adequate mental health evaluations at an early stage, with referral to appropriate adolescent psychiatric services if required. Appropriate service provision and properly planned treatments may reduce the amount of intensive and sometimes unnecessary psychiatric inpatient treatments.     

Parental Age and Risk of Autism Spectrum Disorders in a Finnish National Birth Cohort

Aim of the study was to examine the associations between parental age and autism spectrum disorders (ASD). Data were based on the FIPS-A (Finnish Prenatal Study of Autism and Autism Spectrum Disorders), a case-control study with a total of 4,713 cases with childhood autism (n = 1,132), Asperger’s syndrome (n = 1,785) or other pervasive developmental disorder (PDD) (n = 1,796), which were ascertained from the Finnish Hospital Discharge Register. Controls were selected from the Finnish Medical Birth Register. Conditional logistic regression models were used for statistical analyses. Advanced paternal age (35–49 years) was associated with childhood autism in offspring, whereas advanced maternal age was associated with both Asperger’s syndrome and PDD in offspring (35 years or more and 40 years or more, respectively). Teenage motherhood (19 years or less) was associated with PDD in offspring. The main finding was that maternal and paternal ages were differentially associated with ASD subtypes. In addition to advanced parental age, teenage pregnancy seems to incur a risk for PDD in offspring.     

Effect of glutamate receptor antagonists on migrating neural progenitor cells

Neurotransmitters such as glutamate are potential regulators of neurogenesis. Interference with defined glutamate receptor subtypes affects proliferation, migration and differentiation of neural progenitor cells. The cellular targets for the actions of different glutamate receptor ligands are less well known. In this study we have combined calcium imaging, measurement of membrane potential, time‐lapse imaging and immunocytochemistry to obtain a spatial overview of migrating mouse embryonic neural progenitor cell‐derived cells responding to glutamate receptor agonists and antagonists. Responses via metabotropic glutamate receptor 5 correlated with radial glial cells and dominated in the inner migration zones close to the neurosphere. Block of metabotropic glutamate receptor 5 resulted in shorter radial glial processes, a transient increase in neuron‐like cells emerging from the neurosphere and increased motility of neuron‐like cells. α‐Amino‐3‐hydroxy‐5‐methyl‐4‐isoxazolepropionic acid (AMPA)/kainate receptors are present on the majority of migrating neuronal cells, which with time accumulate at the outer edge of the migration zone. Blocking these receptors leads to an enhanced extension of radial glial processes and a reduced motility of neuron‐like cells. Our results indicate that functional glutamate receptors have profound effects on the motility of neural progenitor cells. The main target for metabotropic glutamate receptor 5 appears to be radial glial cells while AMPA/kainate receptors are mainly expressed in newborn neuronal cells and regulate the migratory progress of these cells. The results suggest that both metabotropic glutamate receptor 5 and AMPA/kainate receptors are of importance for the guidance of migrating embryonic progenitor cells.