Low platelet monoamine oxidase activity and chronic marijuana use

Mean platelet monoamine oxidase (MAO) activity in 26 consecutively-studied male marijuana smokers was significantly lower than in a comparable group of non-marijuana smoking males. In addition, the level of current marijuana use reported by the subjects was significantly and inversely correlated with MAO activity. No acute reduction in MAO activity was found in response to smoking a marijuana cigarette containing 15 mg of delta-9-THC. Significant $\text{in vitro}$ inhibition of MAO activity by THC was detected only at THC concentrations above 10^?5M, approximately 100 times the peak plasma concentrations seen $\text{in vivo}$ following smoking.     

Fetomaternal adrenomedullin levels in diabetic pregnancy.

We investigated whether maternal and fetoplacental adrenomedullin, a newly discovered hypotensive peptide involved in the insulin regulatory system, is modified in diabetic pregnancy. We studied its correlation with pregnancy complications associated with this disease. Thirty-six pregnant women with diabetes (13 with type I and 23 with gestational diabetes mellitus) and in 40 uncomplicated pregnancies were included. 10 out of 36 diabetic pregnancies were complicated by gestational hypertension. In each woman, adrenomedullin concentration in maternal and fetal plasma and in amniotic fluid was assessed by specific radioimmunoassay. We found that overall mean amniotic fluid adrenomedullin concentration was higher (p < 0.05) in diabetic (14.7 +/- 1.6 fmol/ml) than in uncomplicated pregnancies (10.8 +/- 0.9 fmol/ml), whereas no differences were present in maternal and fetal plasma adrenomedullin levels between diabetic and uncomplicated pregnant women. High levels of amniotic fluid adrenomedullin were found in both type I and gestational diabetes mellitus pregnancies (13.7 +/- 1.4 and 15.6 +/- 2.2 fmol/ml, respectively). Diabetic pregnancies complicated by gestational hypertension showed lower (p < 0.05) amniotic fluid adrenomedullin concentrations than normotensive diabetic patients. These findings suggest that placental adrenomedullin production is upregulated in diabetic pregnancy, and it may be important to prevent excessive vasoconstriction of placental vessels.     

Steroid hormone receptors in human malignancy.

Steroid hormones induce responses in target tissues by a mechanism involving the specific initial interaction of hormone with cytoplasmic receptor molecules. These receptors, usually localized in target tissues have high binding affinities and limited binding specificities for biologically active steroids. Examination of human leukemic lymphoblasts has revealed these receptors in some tumor samples. Their presence is well correlated with hormone responsiveness of the tumor $\text{in vitro}$. Similar studies on human breast cancer tumor homogenates has indicated that about $\text{2}\text{3}$ of primary tumors contain estrogen receptor. The absence of receptor predicts a lack of response to hormone therapy almost invariably, while the presence of receptor increases but does not assure that the tumor will be hormone responsive. Recently $\text{in vitro}$ tissue culture systems which mimic the hormone responses observed $\text{in vivo}$ have been developed which should significantly aid in the clarification of the mechanisms whereby steroid hormones stimulate and inhibit growth in target tissues.     

Reduced progesterone metabolites in human late pregnancy

In this review, we focused on the intersection between steroid metabolomics, obstetrics and steroid neurophysiology to give a comprehensive insight into the role of sex hormones and neuroactive steroids (NAS) in the mechanism controlling pregnancy sustaining. The data in the literature including our studies show that there is a complex mechanism providing synthesis of either pregnancy sustaining or parturition provoking steroids. This mechanism includes the boosting placental synthesis of CRH with approaching parturition inducing the excessive synthesis of 3beta-hydroxy-5-ene steroid sulfates serving primarily as precursors for placental synthesis of progestogens, estrogens and NAS. The distribution and changing activities of placental oxidoreductases are responsible for the activation or inactivation of the aforementioned steroids, which is compartment-specific (maternal and fetal compartments) and dependent on gestational age, with a tendency to shift the production from the pregnancy-sustaining steroids to the parturition provoking ones with an increasing gestational age. The fetal and maternal livers catabolize part of the bioactive steroids and also convert some precursors to bioactive steroids. Besides the progesterone, a variety of its 5alpha/beta-reduced metabolites may significantly influence the maintenance of human pregnancy, provide protection against excitotoxicity following acute hypoxic stress, and might also affect the pain perception in mother and fetus.     

Ecdysterone-induced protein synthesis in vitro

Ecdysterone added in vitro to wing tissue from diapausing Antheraea polyphemus pupae induced the synthesis of several epidermal cell proteins. This is one of few instances in which any steroid hormone in physiological concentrations has been able to induce specific protein synthesis in target tissue in vitro soon after hormone stimulation. Hormone-treated tissue was incubated with ³H-leucine while control tissue was incubated with ¹⁴C-leucine. Polyacrylamide gel electrophoretic distribution of labelled wing tissue proteins after ecdysterone stimulation in vitro for various periods of time was determined. The ${}^3\text{H}{}^{14}\text{C}$ ratio emphasized the areas of increased protein synthesis due to ecdysterone. These areas of increased protein synthesis were reproducible with several ecdysterone concentrations and with different incubation times. Induction of protein synthesis occurs at an earlier time period when the hormone dosage is higher, i.e. the lower the dosage, the longer it is necessary for exposure of tissue to hormone. α-Ecdysone, known to initiate the moulting process in vitro in some insect species, also induced protein synthesis. Cortisol, a mammalian steroid hormone, produced no hormone specific protein synthesis. Therefore, the results seen with ecdysterone and α-ecdysone are not the result of non-specific steroid stimulation. When no hormone was added to the incubation medium (control), only one area of the polyacrylamide gel demonstrated protein synthesis. Therefore, there are a few proteins being synthesized in vitro in wing tissue, removed from diapausing animals without hormone stimulation, which may be related to the ‘injury phenomenon’. Protein banding patterns were also determined and compared with the radioactivity profile. The study of such early biochemical and physiological responses of target tissue to hormones will aid in our understanding of a hormone's mechanism of action, since the earlier an event occurs, the more likely that it is the primary result of hormone stimulation.     

Cannabinols and the rosette forming properties of lymphocytes in vitro.

Preincubation of lymphocytes, for 60 minutes at 37°C with tetrahydrocannabinol (THC), obtained from controls produced reduction in early but not total T cell rosettes compared to aliquots treated with vehicle alone. Similar reductions in early rosettes were seen after preincubation with cannabinol, cannabidiol, and olivetol. The marijuana smokers' lymphocytes were less affected by preincubation with THC than those from controls. Presumably their lymphocytes may already have been affected by prior exposure to cannabinols. These data show that THC and other cannabinols can affect the rosetting properties of T cells $\text{in vitro}$ and may provide a model for the study of THC effects on these immunocompetent cells.     

Factors influencing plasma zinc levels in low-income pregnant women

Plasma zinc (Zn) concentrations were measured in 4376 indigent women (86% African-American), at a mean (±SD) gestational age of 15 (±7.8) wk to determine the relationship between various maternal characteristics and plasma Zn levels during pregnancy. Mean plasma Zn levels were lower in African-American women than in Caucasian women, in multiparous women than in primiparous women, and in women with body weight >69.9 kg than in those with body weight ≤69.9 kg (p≤0.001 for each comparison). There were no significant differences related to maternal age, marital status, education, or smoking habit. Multiple regression analysis, including maternal prepregnancy weight, race, age, parity, smoking habit, education, and marital status indicated that race, parity, and pregnancy weight were significantly associated with maternal plasma Zn levels, adjusted for gestational age. Maternal race was the best predictor of plasma Zn concentrations among the population of pregnant women studied A significant proportion of variance in maternal plasma Zn levels remained unexplained after taking into account various maternal characteristics. The reasons for lower plasma Zn levels in African-American women, compared to Caucasian women, during pregnancy are unknown.     

Adenosylhomocysteine hydrolase inhibitors: synthesis of 5'-deoxy-5'-(isobutylthio)-3-deazaadenosine and its effect on Rous sarcoma virus and Gross murine leukemia virus.

One hour following administration of physiological concentrations of the steroid hormone antheridiol to a male strain of the water mold, $\text{Achlya}$$\text{ambisexualis}$, the rate of total cellular protein synthesis is increased. Further analysis revealed a sequential increase in the rate of syntheses for three classes of proteins following hormone stimulation. The rate of ribosomal protein synthesis increased as early as 20–30 minutes, followed by ribosomal salt wash proteins (40–60 minutes) and total soluble proteins after 60 minutes. Patterns of total cellular proteins, resolved by two-dimensional gel electrophoresis, during the first four hours after hormone treatment demonstrated the appearance of two newly synthesized peptides beginning at approximately 40 minutes followed by an increased rate of synthesis of three peptides after one hour. The synthesis of two peptides totally decreased after three hours of hormone induction.     

Effects of prostaglandins on peripheral progesterone and uterine diamine oxidase in the pregnant hamster

Serum progesterone and uterine levels of diamine oxidase (DAO) activity were determined during pregnancy in hamsters. Progesterone was elevated on Day 1 of pregnancy, had a transient peak on Day 5, remained relatively constant on Days 6–10, and then increased on Days 13 and 14. Uterine DAO activity could not be detected until Day 7 of pregnancy, approximately 1 $\text{1}\text{2}$ days after the initiation of implantation. DAO activity was associated with placental tissue, and more than 90% of the activity was localized in the maternal placenta. The temporal relationship between changes in serum concentrations of progesterone and uterine levels of DAO activity following PG administration also was studied. Serum progesterone was significantly depressed by 6 hr after treatment with PGs on Day 7 of pregnancy. However, uterine levels of DAO activity at 6 hr in the treated animals were not different from those in control animals. In contrast, both the serum progesterone concentrations and uterine levels of DAO activity were significantly lower at 24 hr after PG treatment. The effects of PG treatment on uterine DAO activity were completely blocked by concomitant administration of progesterone. However, concomitant administration of Provera® only blocked the effect of one PG analog that was tested (9-deoxo-9-methylene-16,16-dimethyl0-PGE₂). The data indicate that changes in uterine DAO activity following treatment with the PGs used here are primarily a consequence of a decrease in peripheral progesterone (i.e. a luteolytic effect of the PG).     

Decreased placental folate transporter expression and activity in first and second trimester in obese mothers

Obese women have an approximately twofold higher risk to deliver an infant with neural tube defects (NTDs) despite folate supplementation. Placental transfer of folate is mediated by folate receptor alpha (FR-α), proton coupled folate transporter (PCFT), and reduced folate carrier (RFC). Decreased placental transport may contribute to NTDs in obese women. Serum folate levels were measured and placental tissue was collected from 13 women with normal BMI (21.9±1.9) and 11 obese women (BMI 33.1±2.8) undergoing elective termination at 8–22 weeks of gestation. The syncytiotrophoblast microvillous plasma membranes (MVM) were isolated using homogenization, magnesium precipitation, and differential centrifugation. MVM expression of FR-α, PCFT and RFC was determined by western blot. Folate transport capacity was assessed using radiolabeled methyl-tetrahydrofolate and rapid filtration techniques. Differences in expression and transport capacity were adjusted for gestational age and maternal age in multivariable regression models. P<.05 was considered statistically significant. Serum folate levels were not significantly different between groups. Placental MVM folate transporter expression did not change with gestational age. MVM RFC (−19%) and FR-α (−17%) expression was significantly reduced in placentas from obese women (P<.05). MVM folate transporter activity was reduced by−52% (P<.05) in obese women. These differences remained after adjustment for gestational age. There was no difference in mTOR signaling between groups. In conclusion, RFC and FR alpha expression and transporter activity in the placental MVM are significantly reduced in obese women in early pregnancy. These results may explain the higher incidence of NTDs in infants of obese women with adequate serum folate.     

Steroid hormone metabolism by the chorioallantoic placenta of the mountain spiny lizard Sceloporus jarrovi as a possible mechanism for buffering maternal-fetal hormone exchange

The placenta provides a maternal-fetal exchange interface that maximizes the diffusion of gases, nutrients, and wastes. However, the placenta also may permit diffusion of lipid-soluble steroid hormones that influence processes such as sex-specific fetal development and maternal pregnancy maintenance. In mammals, placental steroid metabolism contributes to regulation of maternal and fetal hormone levels. Such mechanisms may be less highly developed in species that have recently evolved placentation, such as many reptiles. We therefore chose to investigate placental metabolism of steroids in the viviparous lizard Sceloporus jarrovi. In vitro tissue incubations tested the abilities of the chorioallantoic placenta to clear progesterone and corticosterone by converting them to other metabolites and to synthesize progesterone. Placental tissue rapidly cleared progesterone and corticosterone added to the incubation media, indicating that the tissue had converted the steroids to other products. Placental tissue also synthesized substantial concentrations of progesterone from the prohormone pregnenolone. Thus, even in a species with a simple, recently evolved placenta, steroid metabolism appears to be highly developed and could be critical for regulation of maternal and fetal hormone levels. This finding suggests that placental hormone metabolism may be critical to the successful evolution of placentation.     

Hormonal regulation of macrophage collagenase activity.

Whereas peritoneal macrophages from nonpregnant guinea pigs were stimulated $\text{in vitro}$ by endotoxin to produce collagenase on the second day of culture, those from pregnant guinea pigs were incapable of this response. However, if the cells from pregnant animals were preincubated for one day prior to endotoxin stimulation, collagenase activity could be detected. Injection of either estrogen or progesterone into guinea pigs at doses comparable to those found during pregnancy prior to removal of the peritoneal cells also inhibited the $\text{in vitro}$ stimulation of collagenase production. The addition of these hormones $\text{in vitro}$ revealed that at 5 × 10^?6 M estrogen and progesterone inhibited 53% and 100% respectively of the collagenase activity. Addition of both hormones at a final concentration of 5 × 10^?7 M of each inhibited 87% of the activity indicating a synergistic effect since this concentration of either hormone alone was ineffective.     

GM-CSF regulation of embryo development and pregnancy

The reproductive tissues undergo profound structural changes and major immune adaptation to accommodate pregnancy. Granulocyte-macrophage colony-stimulating factor (GM-CSF) is one of an array of cytokines with pivotal roles in embryo implantation and subsequent development. Several cell lineages in the reproductive tract and gestational tissues synthesise GM-CSF under direction by ovarian steroid hormones and signalling agents originating in male seminal fluid and the conceptus. The pre-implantation embryo, invading placental trophoblast cells and the abundant populations of leukocytes controlling maternal immune tolerance are all subject to GM-CSF regulation. GM-CSF deficiency in pregnancy adversely impacts fetal and placental development, as well as progeny viability and growth after birth, highlighting this cytokine as a central maternal determinant of pregnancy outcome with clinical relevance in human fertility.     

Study of the fetal and maternal renin-angiotensin system and chorio-placental steroids in the guinea pig]

1.) Total renin, active renin, prorenin, angiotensin II, estradiol and progesterone were measured in maternal, placental and fetal blood and in trophoblastic and uterine tissues of the guinea pig. Furthermore, membrane angiotensin II receptors were measured in trophoblastic tissues. 2.) Blood and tissue concentrations of total renin, active renin, angiotensin II and steroids are shown to increase with gestational age. At the full term of pregnancy (70th post-coital day), tissue concentrations of total renin in chorion (23,900 +/- 2,752 ng/g of tissue/h), maternal placenta (14,210 +/- 1,131), fetal placenta (12,475 +/- 927) and uterus (7,677 +/- 798) are 100 time higher than those observed in placental, fetal and maternal blood. Distribution of blood and tissue prorenin (inactive renin) is similar to that found for total renin. Active renin/Total renin ratio reaches 1% in uterine, placental and chorion tissues and 9.3 +/- 1.0% in maternal, placental and fetal blood. 3.) Angiotensin II levels in systemic maternal blood (690 +/- 99 pg/ml) and in uterine blood (467 +/- 84) are higher than those found in placental blood (266 +/- 39) and in different trophoblastic tissues (between 200 and 400 pg/g). Angiotensin II receptor concentrations are highest in chorion. 4.) Regarding the steroid hormones, it is noted that placental and maternal blood contain more progesterone than trophoblastic tissues. The highest concentrations of estradiol are found in chorion tissue and uterine blood. 5.) A positive correlation is observed between angiotensin II and estradiol in uterine blood (r = 0.69, P less than 0.01) and in chorion (r = 0.71, P less than 0.01). These findings indicate that angiotensin II and estradiol could, by their interactions, play an important role in the physiology of pregnancy.     

Steroid induction of nerve growth factor synthesis in cell culture

Nerve growth factor (NGF) is a peptide hormone which is necessary for the development of sympathetic neurons. Exposing a rat central nervous system glioma cell line (C-6) to the steroid hormone 17β-estradiol increases the amount of NGF secreted by these cells into the surrounding medium. This induction is highly specific to 17β-estradiol in that similar steroids do not increase NGF levels. Both NGF activity and protein levels increase upon estradiol stimulation and there is a parallel increase in NGF $\text{de}$$\text{novo}$ synthesis. The estradiol effect can be blocked with actinomycin D but not with puromycin or cycloheximide. This is the first report demonstrating regulation of NGF synthesis by a steroid hormone in a clonal cell line of glial origin. We propose this system as a model system for the study of the regulation of NGF synthesis and the isolation and analysis of putative precursors to the NGF molecule.     

A proteomic approach identifies early pregnancy biomarkers for preeclampsia: Novel linkages between a predisposition to preeclampsia and cardiovascular disease

Preeclampsia (PE) is a common, potentially life‐threatening pregnancy syndrome triggered by placental factors released into the maternal circulation, resulting in maternal vascular dysfunction along with activated inflammation and coagulation. Currently there is no screening test for PE. We sought to identify differentially expressed plasma proteins in women who subsequently develop PE that may perform as predictive biomarkers. In seven DIGE experiments, we compared the plasma proteome at 20 wk gestation in women who later developed PE with an appropriate birth weight for gestational age baby (n=27) or a small for gestational age baby (n=12) to healthy controls with uncomplicated pregnancies (n=57). Of the 49 differentially expressed spots associated with PE‐appropriate for gestational age, PE‐small for gestational age or both (p<0.05, false discovery rate corrected), 39 were identified by LC‐MS/MS. Two protein clusters that accurately (>90%) classified women at risk of developing PE were identified. Immunoblots confirmed the overexpression of fibrinogen γ chain and α‐1‐antichymotrypsin in plasma prior to PE. The proteins identified are involved in lipid metabolism, coagulation, complement regulation, extracellular matrix remodeling, protease inhibitor activity and acute‐phase responses, indicating novel synergism between pathways involved in the pathogenesis of PE. Our findings are remarkably similar to recently identified proteins complexed to high‐density lipoprotein and linked to cardiovascular disease.     

Maternal Smoking during Pregnancy and Fetal Organ Growth: A Magnetic Resonance Imaging Study

Objective

To study whether maternal cigarette smoking during pregnancy is associated with alterations in the growth of fetal lungs, kidneys, liver, brain, and placenta.

Design

A case-control study, with operators performing the image analysis blinded.

Setting

Study performed on a research-dedicated magnetic resonance imaging (MRI) scanner (1.5 T) with participants recruited from a large teaching hospital in the United Kingdom.

Participants

A total of 26 pregnant women (13 current smokers, 13 non smokers) were recruited; 18 women (10 current smokers, 8 nonsmokers) returned for the second scan later in their pregnancy.

Methods

Each fetus was scanned with MRI at 22–27 weeks and 33–38 weeks gestational age (GA).

Main outcome measures

Images obtained with MRI were used to measure volumes of the fetal brain, kidneys, lungs, liver and overall fetal size, as well as placental volumes.

Results

Exposed fetuses showed lower brain volumes, kidney volumes, and total fetal volumes, with this effect being greater at visit 2 than at visit 1 for brain and kidney volumes, and greater at visit 1 than at visit 2 for total fetal volume. Exposed fetuses also demonstrated lower lung volume and placental volume, and this effect was similar at both visits. No difference was found between the exposed and nonexposed fetuses with regards to liver volume.

Conclusion

Magnetic resonance imaging has been used to show that maternal smoking is associated with reduced growth of fetal brain, lung and kidney; this effect persists even when the volumes are corrected for maternal education, gestational age, and fetal sex. As expected, the fetuses exposed to maternal smoking are smaller in size. Similarly, placental volumes are smaller in smoking versus nonsmoking pregnant women.     

Teratogenicity of acetaldehyde invitro: Relevance to the fatal alcohol syndrome

Day 10 rat embryos grown $\text{in}$$\text{vitro}$ showed significant retardation in growth and development when culture media contained acetaldehyde. A concentration-response range for acetaldehyde-induced embryotoxicity was defined, from no effect at 5μM to complete lethality at 100μM. The relative teratogenicity of ethanol and acetaldehyde, and the potential roles of these compounds in producing the Fetal Alcohol Syndrome are discussed.Despite intensive investigation into alcohol teratogenicity, the mechanism that produces the Fetal Alcohol Syndrome (FAS) remains unknown. Observed anomalies may result from direct embryonic exposure to ethanol or one of its metabolites, or from some indirect effect such as altered placental function or maternal nutritional status. Use of $\text{in}$$\text{vitro}$ techniques allows study of direct embryonic exposures in the absence of indirect influences. Under such conditions, ethanol has been found to exert direct embryotoxicity (1). Rat embryos, grown as cultured explants and subjected to ethanol concentrations of 32.5 or 65mM, were retarded in growth and development when compared to untreated controls. In this paper, we report direct embryotoxic effects of acetaldehyde, the primary metabolite of ethanol, at concentrations as low as 25μM.Acetaldehyde teratogenicity has not been extensively studied. Veghelyi et al. (2) and Lambert, Papp and Nishiura (3) employed a combination of ethanol and disulfiram (an inhibitor of acetaldehyde-oxidizing enzymes). Teratogenic effects exceeded expectations based upon assumption of an additive interaction between these two compounds, and were attributed to elevated maternal blood acetaldehyde. O'Shea and Kauffman (4,5) and Dreosti et al. (6) administered acetaldehyde to pregnant animals by injection. Treatment resulted in retarded growth and development, decreased DNA synthesis, and increased frequencies of malformation and resorption. While these studies imply a role for acetaldehyde in alcohol-induced teratogenesis, indirect effects through altered maternal or placental factors cannot be eliminated. We present here the first concentration-response data for direct ebryonic exposure to acetaldehyde.     

The effects of 9-ene-tetrahydrocannabinol on hormone release and immune function

We investigated effects of 9-ene-tetrahydrocannabinol (THC) on endocrine and immunological function. Seventeen male volunteers entered into a double blind, randomized study to receive oral THC (10 mg t.i.d. for 3 days and on the morning of the fourth day) or placebo, after at least 2 weeks of abstinence. Plasma prolactin, ACTH, cortisol, luteinizing hormone and testosterone were not altered during or after THC, compared with baseline concentrations. Tests of lymphocyte function showed no differences compared to baseline between THC and placebo groups. As the relatively low dosing regimen of THC (10 mg t.i.d.) resulted in no alterations, another group of 6 men were administered higher doses of THC by inhalation (18 mg/marijuana cigarette) following the same dosing regimen. No endocrine or immunological alterations were observed. When the subjects were grouped according to their history of THC use prior to admission, heavy THC users had lower prolactin concentrations than light users. No differences were observed in concentrations of other hormones or in tests of immune function.     

Trophoblast regulation of maternal-paternal lymphocyte interactions

The modification of immunological responses by murine embryonic trophoblast cells was investigated using the mixed-lymphocyte reaction (MLR) and cell-mediated lympholysis (CML) test. In MLR containing Balb/c (responder) and C57BL/6 (stimulator) splenocytes DNA synthesis was markedly reduced in the presence of ectoplacental cone or placental trophoblast cells. These same trophoblast cell populations inhibited the in vitro generation of cytotoxic lymphocytes while cultures containing nontrophoblast regulator cells expressed normal cytotoxicity. DNA synthesis in MLR and cytotoxic activity in CML were not suppressed in cultures containing $\text{3}\text{1}\text{2}$ day blastocyst outgrowths. The potent immunosuppressive properties of the trophoblast may be important during pregnancy by protecting the genetically dissimilar fetus from potentially harmful maternal immune effector mechanisms.