Yuki Shimaoka

Changes in cytokine production during and after normal pregnancy

PROBLEM: The systemic T helper 1/T helper 2 (Th1/Th2) cytokine balance during normal human pregnancy is controversial, and observations about the balance in the postpartum period have only been reported for up to 3 months.
 METHOD: Whole‐blood, from 83 healthy pregnant women, 80 healthy postpartum women, and 31 healthy non‐pregnant women was stimulated with phorbol 12‐myristate 13‐acetate (PMA) and ionomycin, and the levels of cytokines in the supernatant were measured by enzyme‐linked immunosorbent assay (ELISA).
 RESULTS: The production of all measured cytokines decreased during pregnancy, especially in the second trimester. After delivery, interferon‐Γ (IFN‐Γ) and interleukin‐2 (IL‐2) increased from 2 to 11 months postpartum, and IL‐4 increased from 6 to 11 months postpartum.
 CONCLUSIONS: These data indicate that 1) decreases in production of both Th1‐ and Th2‐type cytokines during pregnancy may be related to the pregnancy‐induced amelioration of autoimmune diseases; 2) increases in production of both Th1‐ and Th2‐type cytokines in the postpartum period may be related to the postpartum aggravation of autoimmune diseases.

Characteristics of experimental autoimmune hypophysitis in rats : Major antigens are growth hormone, thyrotropin, and luteinizing hormone in this model

We produced experim entalautoimmune hypophysitis (EAH) in rats and investi gated its characteristics. Female Lewis rats were immunized by two injections with homologous pituitary homogenate and complete Freund’s adjuvant. Blood was coll ected seri ally from the rats, and serum antibodies to pituitary antigens were examined . The rats were sacrificed 2 or 4 weeks after the final immunization, and hi stological examinations of the endocrineorgans were carried out. Hi stolog ical examination revealedslight , focal infiltration of mononuclearcells in the pituitary gland only in the rats immunized with the pituitary homogenate. Infiltration of mononuclearcells was not observed in the thyroidgland , pancreas, adrenal gland , or ovary. In the serological examination, antibodies to bothcytoso licantigens and cytoplas micparticle a nti gens from the pituitaryg land were detected by enzyme- linked immunosorbent assay (ELISA), and these antibody levels increased with time. We stern blottingusing the sennn antibodiesidentified an immunoreactive protein of -2 1.5 k.Daamo ng these antigens, and we confirmed that this protein was ratgrow thhormone (GH). Furth ermore, antibodies to GH, thyrotropin (TSH), and luteinizing hormone (LH) were detected by E LISA. Antibodies to folli cule stimulating horm one, prol actin , or adrenocorticotropin were not detected . These data suggest that several antigens from the pituitary gland are involved in EAH inrats, and that GH, TSH, and LH are major antigens among the pituitary antigens in this model.

Serum concentrations of androstenediol and androstenediol sulfate, and their relation to cytokine production during and after normal pregnancy.

Since it is known that androstenediol (ADIOL) has potent immunoregulatory effects, changes in ADIOL levels during and after pregnancy might affect the maternal immune system. We examined serum concentrations of ADIOL and androstenediol 3-sulfate (ADIOLS) together with IFN-gamma and IL-4 production levels during pregnancy and after delivery up to 10-11 months postpartum. The subjects were 73 normal pregnant, 76 normal postpartum, and 28 normal non-pregnant women. ADIOL and ADIOLS were measured using EIA and GC/MS, respectively. The cytokine levels in the supernatant of whole-blood cultures stimulated with phorbol 12-myristate 13-acetate and ionomycin were measured using ELISA. ADIOL levels significantly decreased compared to non-pregnant levels in the first trimester (P < 0.05) and were reversed in the third trimester (P < 0.05). After pregnancy, ADIOL levels gradually declined, and a significant decrease was observed at 10-11 months postpartum (P < 0.05). ADIOLS levels were significantly lower in the third trimester (P < 0.05) and significantly higher at the first month postpartum (P < 0.001) compared to non-pregnant women. IFN-gamma and IL-4 levels decreased during pregnancy and subsequently increased postpartum. On the other hand, we found significant negative correlations between ADIOL concentrations and production levels of IFN-gamma (P < 0.05) or IL-4 (P < 0.05). These findings suggest that ADIOL may be involved in modifying the maternal immune response during and after pregnancy.

Influence of breast-feeding on the production of cytokines

PROBLEM: Recently, we reported increases in the production of interferon‐γ (IFN‐γ), interleukin‐2 (IL‐2), and IL‐4 during the postpartum period. The present study was undertaken to investigate whether these increases might be explained by increased prolactin while breast‐feeding.
 METHOD: Whole blood from 41 women who were breast‐feeding, 13 women not breast‐feeding, and 31 healthy non‐pregnant women was stimulated with phorbol 12‐myristate 13‐acetate and ionomycin, and the levels of cytokines in the supernatant were measured by enzyme‐linked immunosorbent assay. Their serum levels of prolactin were measured by enzyme immunoassay.
 RESULTS: Increases in IFN‐γ, IL‐2, IL‐4, and IL‐10 production were observed in women who were breast‐feeding but not in women who were not breast‐feeding. Serum levels of prolactin correlated with the levels of IFN‐γ in culture supernatant.
 CONCLUSIONS: These results suggest that breast‐feeding induces production of cytokines and that IFN‐γ production is enhanced by physiological concentrations of prolactin.

Relation between post-partum liver dysfunction and anti-cytochrome 2D6 antibodies.

Problem:  Autoimmune thyroid disease frequently aggravates or develops after delivery through the immune rebound mechanism. However, little is known about the post‐partum development of autoimmune hepatitis (AIH).

Precise method for measuring spatial coherence in TEM beams using Airy diffraction patterns

We have developed a method to precisely measure spatial coherence in electron beams. The method does not require an electron biprism and can be implemented in existing analytical transmission electron microscopes equipped with a post-column energy filter. By fitting the Airy diffraction pattern of the selector aperture, various parameters such as geometric aberrations of the lens system and the point-spread function of the diffraction blurring are precisely determined. From the measurements of various beam diameters, components that are attributed to the partial spatial coherence are successfully separated from the point-spread functions. A linear relationship between the spatial coherence length and beam diameter is revealed, thus indicating that a wide range of coherence lengths can be determined by our proposed method as long as the coherence length remains >80% of the aperture diameter. A remarkable feature of this method is its ability to simultaneously determine diffraction blurring and lens aberrations. Possible applications of this method are also discussed.

Refined Phase Imaging by Electron Diffractive Imaging

Phase imaging of transmission electron beams is indispensable in visualizing electromagnetic fields in and around nanometer-sized semiconducting or magnetic devices as well as detecting sample thickness and composition based on its mean inner potential. Although the most established method for the phase imaging is presently off-axis electron holography, another choice could be electron diffractive imaging (EDI). In the method, a complex wave field is reconstructed from a diffraction pattern through numerical iterations under some constraints. So far we have succeeded in reconstructions of atomic structures of crystals [1,2], thickness maps of wedge-shaped Si [3] and a p-n junction [3,4].