Ethanol-Induced Changes in Peripheral Blood and Splenic Natural Killer Cells

Previous work demonstrated that splenic natural killer (NK) cell cytolytic activity was suppressed in ethanol-consuming mice within 1 week and for as long as 10 weeks concurrent with ethanol intake. However, it is unknown if suppression of NK cell activity with ethanol consumption results from regional losses in NK cells. The present experiments were designed to examine the effect of ethanol on the percentage and total number of NK cells in the spleen and blood. Data indicate that, after 4 weeks of ethanol intake, NK cell activity of peripheral blood lymphocytes was also suppressed (50% of controls). With short-term (2-week) exposure, the percentage of NK cells in the blood and the spleen remained relatively constant. In the spleen, changes in the number of NK cells reflected generalized fluctuations in lymphocyte numbers rather than variation in the percentage of NK cells. NK cells were most sensitive to the effects of ethanol during long-term (8-week) ethanol intake, as demonstrated by significant reductions in the total percentage of NK 1.1⁺ cells in the blood, and the LGL-1⁺ subset in the blood and spleen.
These results provide insight into the mechanism of NK modulation by ethanol. Because NK cells were not selectively depleted after 2–4 weeks of ethanol intake, loss of cytolytically active NK cells cannot explain the suppression of in vitro cytolytic activity of cells from ethanol-consuming mice. However, with prolonged ethanol intake (8 weeks), the depletion of NK cells, specifically the LGL-1⁺ subset, may contribute to the overall suppression of NK cell cytolytic function.     

Flow Cytometric Analysis of Lymphocyte Subsets of Mice Maintained on an Ethanol-Containing Liquid Diet

Alcoholic patients often have impaired immune function, yet little is known about the precise mechanism(s) of this impairment. We have previously shown that ethanol consumption by mice alters copolymer-specific humoral and cellular immune responses. In this study, we asked whether alcohol consumption by mice would phenotypically alter lymphocyte populations. Female C57BL/6 mice were fed a nutritionally complete liquid diet containing 35% ethanol-derived calories for up to 8 days. As controls, mice either were fed a liquid control diet that isocalorically substitutes sucrose for ethanol or remained on a standard solid diet and water ad libitum. Although mice fed ethanol-containing liquid or pair-fed control liquid diets have decreased numbers of spleen cells compared with solid diet controls, only the ethanol-containing diet allowed normally nonresponder C57BL/6 spleen cells to make antibody responses to the poly(Glu⁵⁰Tyr⁵⁰) synthetic copolymer antigen. Flow cytometric analysis of splenic lymphocyte populations of mice on the ethanol-containing diet shows an increase in the relative proportion of T-lymphocytes as compared with mice on either solid or liquid control diets. No such change is seen for either B-cell or natural killer cell populations in these same mice. Both liquid control and liquid ethanol diets caused a slight decrease in the CD4:CD8 ratios of splenic T-lymphocytes. We see the relative percentage of T-cells bearing the αβ-cell receptor (TcR) increases in the spleens of liquid ethanol diet mice; a smaller increase TcRαβ usage is seen in the spleens of liquid control mice, compared with solid diet mice. Flow cytometric analysis shows that little, if any, difference exists in TcRγδ expression between the liquid ethanol and either the liquid control or solid diet groups. Preliminary analysis of TcRαβ subsets suggest that ethanol increases the percentage of T-cells expressing Vβ5 and Vβ8, and decreases the percentage of Vβ11 expressing cells. These findings suggest that, in addition to modifying the immune response, ethanol alters the phenotypic expression of lymphocyte subsets.     

Comparison of Two Flow Cytometric Methods for Detection of Human Invariant Natural Killer T Cells (iNKT)

Background: Invariant natural killer cells (iNKT) are an important immunoregulatory T cell subset. Currently several flow cytometry-based approaches exist for the identifi-cation of iNKT cells, which rely on using the 6B11 monoclonal antibody or a combina-tion of anti-Vα24 and anti-Vβ11 antibodies. Objective: The aim of this study was to compare the ability of two flow cytometry-based methods for detecting the frequency of circulating iNKT cells. Methods: The frequency of iNKT cells was detected in the pe-ripheral blood of 37 healthy adult donors by flow cytometry using the 6B11 antibody or a combination of anti-Vα24 and anti-Vβ11 antibodies. Results: The frequency of iNKT cells detected by 6B11 antibody or by combination of anti-Vα24 and anti-Vβ11 anti-bodies was significantly different (0.54% vs. 0.31%, respectively, p<0.001) but the val-ues were highly correlated (Spearman r = 0.742, p<0.0001). Conclusion: The results of this study indicate that different combinations of mAbs detect different frequencies of peripheral blood iNKT cells and a consensus in the field needs to be established to al-low better assessment of iNKT-related studies and suggest using different methods for accurate identification of iNKT cells.     

Effect of Ethanol Consumption on Adult Rat Liver Mitochondrial Populations Analyzed by Flow Cytometry

In the present study, the effects of administering ethanol to adult male rats on the distribution of the low fluorescence population (LFP) and high fluorescence population (HFP), and the rhodamine-123 fluorescence intensity of these groups of mitochondria are analyzed by flow cytometry. Our results show that ethanol administration to adult male rats induces a redistribution of the HFP and LFP mitochondrial populations leading to an increase of the less functional HFP mitochondria. In addition, ethanol induced an increase in the mean intensity of green fluorescence of the HFP that is probably related to an increased number of rhodamine-123 binding sites per mitochondria resulting from mitochondria enlargement.     

Involvement of Catecholamines and Glucocorticoids in Ethanol-Induced Suppression of Splenic Natural Killer Cell Activity in a Mouse Model for Binge Drinking

Ethanol (EtOH) suppresses splenic natural killer (NK) cell activity in a mouse binge drinking model. Direct effects of EtOH and its metabolites are not the major cause of this suppression. Also, catecholamines do not completely explain this suppression. This implicates the involvement of other neuroendocrine mediators in this suppression. Previous studies in this laboratory have shown that RU 486 at a dosage of 100 mg/kg did not affect EtOH-induced suppression of NK cell activity. However, in the present study, RU 486 at a dosage of 200 mg/kg partially blocked the suppression of NK cell activity induced by EtOH. Moreover, corticosterone at levels expected in the free (unbound) form in EtOH-treated mice decreased NK cell activity in vitro. Nadolol in combination with RU 486 blocked the suppression of NK cell activity in EtOH-treated mice. Although there were reasons to suspect that EtOH-induced changes in the levels of growth hormone or prolactin might also contribute to the suppression of NK cell activity; evidence obtained herein did not indicate such involvement Thus, glucocorticoids and catecholamines seem to be involved in EtOH-induced suppression of NK cell activity. Together, with the direct effects of EtOH, these neuroendocrine mediators seem to be sufficient to explain all of the suppression of NK cell activity caused by EtOH.     

Thymocytes, pre-B cells, and organ changes in a mouse model of chronic ethanol ingestion--absence of subset-specific glucocorticoid-induced immune cell loss

BACKGROUND: The well-known immune deficiency of the chronic alcoholic dictates the need for a long-term rodent ethanol administration model to evaluate the baseline immunologic effects of chronic ethanol abuse, and investigate the genetic determinants of those effects. Much published work with rodents has shown clearly that acute ethanol administration and short-term ethanol-containing liquid diets both cause elevated corticosterone and can cause significant thymocyte, pre-B cell and peripheral lymphocyte losses. Such losses may mask more subtle alterations in immune homeostasis, and in any case are generally short-lived compared with the span of chronic ethanol abuse. Thus, it is important to have a model in which long-term immune alterations can be studied free of corticosteroid-induced cell losses. METHODS: We have utilized chronic 20% (w/v) ethanol in water administration to several mouse strains for prolonged periods of time and evaluated serum corticosterone, immunologic stress parameters, and other organ changes by standard methods. RESULTS: We now confirm earlier reports that chronic ethanol in water administration to mice does not produce net elevations of corticosterone, although diurnal variation is altered. Importantly, there is neither selective loss of immune cell populations known to be corticosteroid sensitive, CD4+CD8+ thymocytes and pre-B cells, nor are changes observed in the histologic appearance of the thymus. Nonetheless, there are significant chronic ethanol effects in other tissues, including reduced heart weight, mild hepatic steatosis, alterations of gut flora, increased serum peptidoglycan, and as published elsewhere, immune system abnormalities. CONCLUSIONS: This model of ethanol administration is convenient, sustainable for up to 1 year, demonstrably feasible in several mouse strains, permits good weight gains in most strains, and results in significant changes in a number of organs. The administration method also will permit modeling of long-term steady abuse punctuated by major binges, and is suitable for supplementation studies using water soluble additives. Overall, the method is useful for a wide range of studies requiring a chronic low-stress method of ethanol administration.     

慢性胃炎胃黏膜细胞DNA含量和增殖活性的流式细胞仪检测

背景慢性萎缩性胃炎是一种胃癌癌前状态,研究表明正常胃黏膜、癌前病变和胃癌细胞的DNA含量随病变的进展而逐渐增高。目的应用流式细胞仪检测慢性胃炎胃黏膜细胞的DNA含量和增殖活性,探讨两者在慢性胃炎发生、发展过程中的临床意义。方法选取90例经胃镜检查诊断为慢性胃炎者的胃黏膜活检标本,制备单细胞悬液,应用流式细胞仪进行细胞DNA含量和增殖活性检测。结果所有慢性胃炎胃黏膜细胞的DNA倍体类型均为二倍体,但慢性萎缩性胃炎和慢性萎缩性胃炎伴肠化生胃黏膜细胞的增殖指数(PI)较慢性非萎缩性胃炎显著增高(P<0.05)。除慢性非萎缩性胃炎外,其余慢性胃炎组幽门螺杆菌(H.pylori)阳性患者胃黏膜细胞的PI值均较阴性患者显著增高(P<0.05)。结论慢性萎缩性胃炎和H.pylori阳性慢性胃炎胃黏膜细胞的增殖活性显著增高。应用流式细胞仪检测胃黏膜细胞的DNA含量和增殖活性,也许能成为胃癌癌前状态和癌前病变病理诊断的参考指标。     

Selective Vulnerability of Embryonic Cell Populations to Ethanol-Induced Apoptosis: Implications for Alcohol-Related Birth Defects and Neurodevelopmental Disorder

BACKGROUND: Ethanol-induced cell death has been characterized in very few stages of embryogenesis. This investigation comprehensively maps patterns of both programmed and ethanol-induced cell death in the central nervous system and craniofacial region at 0.5-day intervals from gestational day (GD) 6.5 to 11 in mice. METHODS: A teratogenic dosage of ethanol (2.9 g/kg) or vehicle was administered via two intraperitoneal injections to pregnant C57BL/6J mice at various stages of gestation. Cell death patterns were characterized using Nile blue sulfate vital staining and histological analysis of plastic sections. Confocal laser scanning microscopy of LysoTracker Red-stained specimens allowed for three-dimensional visualization of areas of apoptosis and precise sectional imaging of mouse embryos. Apoptosis was also documented using a TUNEL technique on histological sections. RESULTS: Normal programmed cell death in control embryos was noted in the prechordal plate region at GD 8, the neuroepithelium of the fourth ventricle and anterior neuropore at GD 9, and within the ganglia of cranial nerves V, VII-VIII, IX, and X at GD 10. Acute maternal ethanol administration 12 hr before examination resulted in a dramatic increase in apoptosis within sites of programmed cell death in the embryo. Moreover, ethanol-exposed specimens exhibited stage-dependent excessive cell death in other distinct cell populations, particularly within the developing central nervous system. Ethanol-induced apoptosis was notable as follows: GD 7.5-neuroectoderm; GD 8-neural plate and primitive streak; GD 9-alar plate and presumptive neural crest of the rostral hindbrain, especially at the mesencephalon/rhombencephalon junction; GD 9.5-10-branchial arches and rhombomeres; and GD 11-diencephalon, basal ganglia, pons, and developing cerebellum. CONCLUSIONS: The results of this study revealed developmental stage-specific cell populations of the developing brain and craniofacial region that are vulnerable to ethanol-induced apoptosis and provide new insight relative to the genesis of alcohol-related birth defects.     

Apoptosis and Bcl-2 Protein Expression in Experimental Alcoholic Liver Disease in the Rat

We used the intragastric feeding rat model to investigate the relationship between severity of alcoholic liver injury, apoptosis, bcl-2 protein expression, and lipid peroxidation. Rats were fed ethanol with different dietary fats (saturated fat, corn oil, and fish oil) for a 1-month period. Apoptosis was evaluated using an immunohistochemical method, and flow cytometry. Bcl-2 protein concentrations in liver were evaluated by Western blot analysis and lipid peroxidation by measurement of conjugated diems. Pathological changes (fatty liver, necrosis, and inflammation) were present in com oil-ethanol and fish oil-ethanol groups only. The highest number of apoptotic cells were seen in the group of rats exhibiting her Injury. The fish oil-ethanol-fed group had the highest concentrations of bcl-2 protein; this protein was localized in the bile duct epithelial and inflammatory cells. A significant correlation was seem between bcl-2 protein assessed densitometrically and the number of inflammatory cells/mm² ( r = 0.78, p < 0.02) and conjugated diene levels ( r = 0.82, p < 0.01). Increased numbers of apoptotic cells were seen in rats developing ethanol-induced pathological liver injury. Increased bcl-2 protein concentrations are associated with the presence of inflammatory cells and lipid peroxidation.     

Distribution of Peripheral Blood Lymphoid Subsets in Alcoholic Liver Cirrhosis: Influence of Ethanol Intake

The aim of the present study was to investigate the effect of chronic ethanol (EtOH) consumption on the immune system in patients with alcoholic liver cirrhosis (ALC), as analyzed by the distribution of peripheral blood (PB-) T, B, and NK lymphoid subsets using multiple stainings with monoclonal antibodies and flow cytometry. For that purpose, we have analyzed a group of patients with ALC and active EtOH intake (ALCET group) which were re-evaluated 3 months after alcohol withdrawal. As controls, both ALC patients with at least 1 year of alcohol withdrawal (ALCAW group) and healthy subjects were used. Regarding the alcohol intake period, the most relevant findings were a significant activation of the PB T-cell compartment, and specifically of the TCR alpha beta+ subset, as reflected by an increased expression of both the HLA DR and CD11c antigens as well as a significant increase of both the PB NK cells (CD3-/CD56+) and the cytotoxic T cells coexpressing the CD3 and CD56 molecules. In addition, a decrease of both the numbers of total B cells and their CD5+/CD19+ subset were observed. After a relatively short withdrawal period (3 months), the abnormalities of T, P, and NK cells disappeared. These findings suggest the existence of a close relationship between EtOH consumption and the abnormalities of the immune system observed during active alcoholism. Nevertheless, ALCAW individuals displayed marked alterations on the immunophenotypic profile, as reflected by a significantly decreased number of total T cells, due to reduced levels of the CD3+/TCR alpha beta+, CD4+, CD8+, and CD4+/CD45RA+ T-cell subsets. In addition, a significantly decreased number of total PB B cells was observed in this group of patients. Our results show that in patients suffering from ALC, the abnormalities of the immune system due to a direct effect of EtOH intake (or its metabolites) should be distinguished from the immunological alterations related to the liver disease itself.     

Involvement of Protein Kinase C in Ethanol-Induced Inhibition of NMDA Receptor Function in Cerebellar Granule Cells

Ethanol inhibits N -methyl- d -aspartate (NMDA)-stimulated increases in intracellular Ca²⁺ in cerebellar granule cells apparently by reducing the potency of glycine to act as a co-agonist at the NMDA receptor. The inhibitory effect of ethanol on the NMDA response in these cells can be reversed not only by a high concentration of glycine, but also by the protein kinase inhibitors, staurosporine and calphostin C. We previously showed that activation of protein kinase C in cerebellar granule cells also resulted in inhibition of the NMDA response, and in decreased potency of glycine at the NMDA receptor. Furthermore, the inhibitory effects of ethanol and protein kinase C activation are not additive. These results suggest a role for protein kinase C in ethanol inhibition of NMDA responses in cerebellar granule cells. In contrast, although ethanol can inhibit the response to kainate in these cells in a "competitive" manner, this response is not affected by activation of protein kinase C.     

Comparison of Flow Cytometry and Histology with Mutational Screening for p53 and Ki-ras Mutations in Surveillance of Patients with Long-standing Ulcerative Colitis

Background: We evaluate the usefulness of screening for p53 and Ki-ras mutations in comparison with histological and flow cytometric findings. Methods: We analyzed 1486 biopsy samples from 769 locations of 83 patients with long-standing ulcerative colitis enrolled in a surveillance program by means of histology, flow cytometry and SSCP analysis. As a control we used 66 biopsy samples of 16 patients with irritable bowel disease. Results: With respect to all biopsy samples analyzed, DNA aneuploidy was found in 32.5% (27/83) of patients, dysplasia in 22.9% (15/83), p53 in 21.7% (18/83) and Ki-ras mutations in 18.1% (15/83) of patients. None of these markers was found in our control group. In 7 out of 10 patients who displayed dysplastic findings during endoscopic surveillance p53 and / or Ki-ras mutations were present in at least one colonoscopy. Statistically significant associations were observed between dysplasia and DNA aneuploidy ( P < 0.001), between dysplasia and p53 mutations ( P = 0.05) and between dysplasia and p53 and/or Ki-ras mutations ( P = 0.002). No significant associations were found between dysplasia and Ki-ras mutations alone. The results for the SSCP analysis showed a much broader variation than those for the flow cytometric analysis. Conclusions: These results show that screening for p53 and Ki-ras mutations can be a useful adjunct in surveillance of patients with longstanding ulcerative colitis.     

Chronic Ethanol Exposure Alters Leukocyte Subsets in Repopulating Spleens, But Does Not Alter Negative Selection in Thymuses of Sublethally Irradiated Mice

Results from previous in vitro experiments in this laboratory suggested that ethanol may affect selection processes in the thymus. To determine whether ethanol allows escape of potentially autoreactive T-cell clones from negative selection, we fed ethanol to sublethally irradiated, young, adult C57BR mice during the time of thymic and splenic repopulation as a new model of human third trimester fetal alcohol exposure. The mice received a whole-body, sublethal dose (6 Gy) of gamma irradiation at 5 to 6 weeks of age. Feeding of a liquid diet providing 25% of calories as ethanol (EDC) or an isocaloric control liquid diet was begun 3 days after irradiation and was continued for 5 weeks. Each EDC mouse had 2 weight- and age-matched controls, 1 pair-fed (PF), and 1 fed ad libitum (AD LIB). Average blood alcohol concentrations (90 to 440 mg/100 ml) were higher than those reported previously for neonatal mice exposed to ethanol through lactation. At 5 weeks after irradiation, the EDC mice had lower total thymocyte numbers ( p < 0.05) and a higher proportion of CD4^- CD8^- thymocytes than either the PF or AD LIB mice ( p < 0.05), which is consistent with findings using in utero models of ethanol exposure. Ethanol exposure also altered the proportion of leukocyte subsets in repopulating spleens. B cells were the most sensitive to the detrimental effects of ethanol and, as a percentage of total nucleated cells in the spleen, B cells were decreased in the EDC group, compared with both the PF and AD LIB groups ( p < 0.05). C57BR mice normally delete by negative selection thymocytes bearing vβ17⁺ T-cell receptors. There was no discernible effect of ethanol exposure during thymic and splenic repopulation on the expression of Vβ17a on thymocytes and splenic T lymphocytes, indicating that ethanol does not affect negative selection.     

单核样髓源性抑制细胞在炎症性肠病中的表达及其临床意义

背景：近年来炎症性肠病（IBD）发病率呈上升趋势,其病理生理学机制复杂且仍未明确。目的：研究单核样髓源性抑制细胞（MDSCs）在IBD患者外周血单核细胞中的比例,分析单核样MDSCs与IBD活动性的关系,从而初步探讨单核样MDSCs在IBD中的作用机制。方法：纳入IBD患者60例,分为克罗恩病（CD）组（n=33）和溃疡性结肠炎（UC）组（n=27）,选取30名同期健康体检者作为正常对照组,采用流式细胞仪检测CD组、UC组、正常对照组患者外周血单核样MDSCs／单核细胞比例,分析单核样MDSCs与IBD患者WBC、PLT、ESR、CRP的相关性。结果：CD组和UC组外周血单核样MDSCs／单核细胞比例较正常对照组相比显著升高[（43．7±23．0）％、（49．1±27．2）％对（10．7±7．4）％]（P〈0．01）,CD组与UC组相比差异无统计学意义（P〉0．05）。活动期CD和UC组外周血单核样MDSCs／单核细胞比例均较缓解期组显著升高[（60．3±16．8）％、（66．3±17．6）％对（28．1±16．2）％、（19．9±9．0）％]（P〈0．01）。IBD患者外周血单核样MDSCs／单核细胞比例与WBC计数、PLT计数呈正相关（r=0．44,P=0．02;r=0．43,P=0．02）,与ESR、CRP不相关（r=0．33,P=0．08;r=0．30,P=0．12）。结论：IBD患者外周血单核样MDSCs比例明显升高,与IBD活动性密切相关。单核样MDSCs在IBD发病中具有重要作用。     

固有淋巴细胞分化与肠道菌群调节研究进展

摘要固有淋巴细胞（ILCs）既是固有免疫的效应细胞,又是获得性免疫的前体细胞,可根据其表达的转录因子和产生效应分子的类型分为不同亚群,包括T—bet＋ ILC（ILCl）、GATA3＋ ILC（ILC2）和RORγt＋ILC（ILC3）。肠道菌群参与了ILCs的分化,同时ILCs可通过产生不同类型的细胞因子影响肠道菌群组成。本文就ILCs分化与肠道菌群调节之间的相互关系以及ILCs在肠道菌群失调相关疾病中的作用作一综述。     

Cross Evaluation of Three Flow Cytometric F Cell Counting Methods Performed by Different Laboratories

Three flow cytometric methods of counting F cells were evaluated in the settings of an external laboratory assessment scheme. The laboratories to participate with a different method were located in Oxford (method O), Athens (method A) and Jerusalem, (method J). Two monoclonal anti-γ chain antibodies were used: monoclonal antibody produced by P. Beverley (Oxford) (BEV) and an antibody provided by Bioatlantic S.A.R.L. (France) (BIO). The specimens tested were mixtures in five predefined ratios of a sample with homozygous δβ-thalassemia with 100% F cells with a sample with no F cells. A central independent laboratory prepared and distributed the aliquots (at room temperature) to the participating centers within 2 (O), 3 (A), and 6 (J) days. The performance of the three methods was evaluated by: 1) deviation indices, 2) relative accuracy, as percent difference of the counts from the target values, and 3) bias and linearity by linear regression of the counts versus the target values [parameters: slope (s), y-intercept (y), R squared (Rs), and F ratio]. The highest score of performance was obtained by method A with both monoclonal antibodies.     

Cytochemistry of dipeptidylaminopeptidase IV and II in normal and neoplastic lymphoid cells

Summary Cytochemical methods were used to determine the distribution of dipeptidylaminopeptidase IV (DAP IV) and II (DAP II) in lymphoid cell populations from patients with lymphoproliferative diseases. Special attention was paid to unusual intracellular distribution patterns which might correlate with the presence of various membrane markers. In healthy patients, about 50% of the circulating lymphocytes were found to be positive to both reactions, the intracellular distribution patterns being variable. The DAP IV reaction was negative in all B-CLL cases. In 2 cases of T-CLL with phenotype E⁺ OKT ₃ ⁺ T ₄ ^– T ₈ ⁺ one was negative and one was weakly positive, while two cases of T-CLL with phenotype E⁺ OKT ₃ ⁺ T ₄ ⁺ T ₈ ^– were both strongly positive. The other non-T lymphoproliferative diseases studied were negative for DAP IV, while one T-ALL and three T-lymphoma cases showed a strong granular or diffuse distribution. The DAP II reaction was strongly positive in all the T lymphoproliferative diseases studied, irrespective of their immunological phenotype. This reaction was also weakly positive in some cases of plasmocytoma and lymphoplasmocytoid lymphoma.     

Ethanol induces cell death and cell cycle delay in cultures of pheochromocytoma PC12 cells

Animal models have clearly established that ethanol exposure can deplete neurons in the developing nervous system. However, the mechanism by which ethanol reduces cell number is unclear. In our study, cultures of pheochromocytoma cells, a neuronal-like cell line, were maintained in media, which supported cell proliferation. Although cell numbers continued to increase in the presence of ethanol, this increase was partially inhibited by ethanol exposure. This inhibitory effect was concentration and duration dependent. Cell proliferation was still partially inhibited after removal of ethanol, but this inhibition was temporary and disappeared after a 24-hr recovery period in ethanol-free conditions. Further study indicated that ethanol partially inhibited the increase in cell numbers by two mechanisms: (1) studies with vital stains indicated that ethanol induced cell death; (2) experiments using synchronized pheochromocytoma cell cultures showed that ethanol can induce cell cycle delay, thereby lengthening the doubling time of the cells. Analysis by flow cytometry indicated that with ethanol exposure, the cells accumulated in the G1 phase of the cell cycle. Our results suggest that in the developing nervous system, ethanol may limit the numbers of proliferating, neuronal precursor cells by two simultaneous mechanisms, cell death and cell cycle delay.     

Ethanol-Induced Changes in Prostaglandin E Concentration in the Intact Cerebral Cortex of Preterm and Near-term Fetal Sheep

Ethanol-induced changes in fetal prostaglandin E (PGE) concentration may play a role in the toxic effects of prenatal ethanol exposure. Using the novel technique of in utero microdialysis, the present study tested the hypothesis that acute ethanol exposure changes PGE concentration in the intact cerebral cortex of preterm (93 ± 1 days of gestation) and near-term (124 ± 1 days of gestation; term, ∼147 days) fetal sheep. Fetal sheep were surgically instrumented with a microdialysis probe placed in the parasagittal parietal cortex. Three days later, the effects of maternal infusion of 1 g of ethanol/kg maternal body weight on preterm ( n = 6) and near-term ( n = 7) fetal cerebral cortical and plasma PGE concentrations were determined. In the preterm fetal cerebral cortex, PGE concentration was increased after ethanol infusion in all six animals studied. The median peak increase was 160% with a 95% confidence interval of 115 to 784%. There was considerable variation in the time of occurrence, magnitude, and duration of this increase. In the near-term fetal cerebral cortex, an increase in PGE concentration was observed after ethanol infusion in 5 of the 7 animals studied, whereas a decrease in PGE concentration was observed in the other two animals. Overall, ethanol did not increase significantly near-term fetal cerebral cortical PGE concentration. For both age groups, ethanol infusion had no effect on fetal plasma PGE concentration. These data indicate that ethanol can affect PGE production in the fetal cerebral cortex and that this effect seems to be gestational-age-dependent.