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Biomedical subjects

S Fried

Publications and source records attributed to S Fried.

At least 19 recordsLinked to original sources

Binge alcohol consumption by non-alcohol-dependent women during pregnancy affects child behaviour, but not general intellectual functioning; a prospective controlled study.

Effects of binge ethanol consumption during early gestation on child neurodevelopment have not been elucidated. To study whether binge drinking affects cognitive abilities and behavior of exposed children, a prospective observational study comparing 51 children exposed to binge drinking during the first trimester of pregnancy to 51 children not exposed to any teratogens was conducted. The children's physical development, intelligence, language abilities and behavior were assessed. Temperament test results showed that children exposed in utero to maternal binge drinking displayed a greater degree of disinhibited behavior and that this behavior was associated with early drinking variables. Although binge alcohol drinking by non-alcohol-dependent women during the first trimester of pregnancy does not appear to affect intelligence or cognitive and language development of young children, binge drinking in pregnancy does increase the likelihood of certain behavioral characteristics that might predispose these children to later behavioral dysfunction.

Adult↗

Neurodevelopment of children exposed in utero to treatment of maternal malignancy.

Cancer is the second most common cause of death during the reproductive years, complicating approximately 1/1000 pregnancies. The occurrence of cancer during gestation is likely to increase as a result of a woman's tendency to delay childbearing. Improved diagnostic techniques for malignancies increases detection of cancer during pregnancy. Malignant conditions during gestation are believed to be associated with an increase in poor perinatal and fetal outcomes that are often due to maternal treatment. Physicians should weigh the benefits of treatment against the risks of fetal exposure. To date, most reports have focused on morphologic observations made very close to the time of delivery with little data collected on children's long-term neurodevelopment following in utero exposure to malignancy and treatment. Because the brain differentiates throughout pregnancy and in early postnatal life, damage may occur even after first trimester exposure. The possible delayed effects of treatment on a child's neurological, intellectual and behavioural functioning have never been systematically evaluated. The goal of this report was to summarize all related issues into one review to facilitate both practitioners' and patients' access to known data on fetal risks and safety.

Child↗

Identification and pharmacological characterization of a novel human melanin-concentrating hormone receptor, mch-r2.

Melanin-concentrating hormone (MCH) is a neuropeptide highly expressed in the brain that regulates several physiological functions mediated by receptors in the G protein-coupled receptor family. Recently an orphan receptor, SLC-1, has been identified as an MCH receptor (MCH-R1). Herein we identify and characterize a novel receptor for human MCH (MCH-R2). The receptor is composed of 340 amino acids encoded by a 1023-base pair cDNA and is 35% homologous to SLC-1. (125)I-MCH specifically bound to Chinese hamster ovary cells stably expressing MCH-R2. MCH stimulated dose-dependent increases in intracellular free Ca(2+) and inositol phosphate production in these cells but did not affect cAMP production. The pharmacological profile for mammalian MCH, [Phe(13),Tyr(19)]MCH, and salmon MCH at MCH-R2 differed compared with MCH-R1 as assessed by intracellular signaling and radioligand binding assays. The EC(50) in signaling assays and the IC(50) in radioligand binding assays of salmon MCH was an order of magnitude higher than mammalian MCH at MCH-R2. By comparison, the EC(50) and IC(50) values of salmon MCH and mammalian MCH at MCH-R1 were relatively similar. Blot hybridization revealed exclusive expression of MCH-R2 mRNA in several distinct brain regions, particularly in the cortical area, suggesting the involvement of MCH-R2 in the central regulation of MCH-mediated functions.

Amino Acid Sequence↗

Lipoprotein lipase and leptin are accumulated in different secretory compartments in rat adipocytes.

Adipose cells produce and secrete several physiologically important proteins, such as lipoprotein lipase (LPL), leptin, adipsin, Acrp30, etc. However, secretory pathways in adipocytes have not been characterized, and vesicular carriers responsible for the accumulation and transport of secreted proteins have not been identified. We have compared the intracellular localization of two proteins secreted from adipose cells: leptin and LPL. Adipocytes accumulate large amounts of both proteins, suggesting that neither of them is targeted to the constitutive secretory pathway. By means of velocity centrifugation in sucrose gradients, equilibrium density centrifugation in iodixanol gradients, and immunofluorescence confocal microscopy, we determined that LPL and leptin were localized in different membrane structures. LPL was found mainly in the endoplasmic reticulum with a small pool being present in low density membrane vesicles that may represent a secretory compartment in adipose cells. Virtually all intracellular leptin was localized in these low density secretory vesicles. Insulin-sensitive Glut4 vesicles did not contain either LPL or leptin. Thus, secretion from adipose cells is controlled both at the exit from the endoplasmic reticulum as well as at the level of "downstream" secretory vesicles.

Adipocytes↗

The melanin-concentrating hormone receptor couples to multiple G proteins to activate diverse intracellular signaling pathways.

The receptor for melanin-concentrating hormone (MCH) was recently identified as the orphan G protein-coupled receptor SLC-1. In this study, a CHO cell line expressing the MCH receptor (Kd = 1.3 nM; binding capacity, 3.6 pmol/mg protein) is used to assess the ability of the MCH receptor to couple to Gi, Go, and Gq proteins. The results demonstrate that MCH inhibits forskolin-stimulated cAMP production in a pertussis toxin- (PTX)-sensitive manner in CHO-MCHR cells (EC50 = 100 pM), indicating that the MCH receptor couples to one or more members of the Gi subfamily of G proteins. In addition, MCH stimulates increases in phosphoinositide metabolism (EC50 = 50 nM) and in intracellular free Ca2+ levels (EC50 = 10 nM). MCH-stimulated inositol phosphate production and increases in intracellular free Ca2+ are partially inhibited (60% and 40%, respectively) by PTX pretreatment, demonstrating that there are at least two components of each of these signaling pathways. One component is PTX sensitive and therefore mediated through a Gi/Go protein. A distinct G protein-coupled (probably Gq type) mediates the PTX-insensitive component. To distinguish Gi vs. Go coupling, MCH-stimulated mitogen-activated protein (MAP) kinase activity was examined. Gi and Go use separate signaling pathways to mediate MAP kinase activation in CHOcells. Protein kinase C (PKC) activity is essential in the Go-dependent MAP kinase signaling pathway, but is not required in the GC-dependent MAP kinase signaling pathway. MCH stimulated MAP kinase activity is decreased (50%), but not abolished, by inhibition of PKC activity or depletion of cellular PKC, indicating that MCH-stimulated MAP kinase activity is mediated through both Gi- and Go-dependent signaling mechanisms. The results of this study are the first to clearly demonstrate that the MCH receptor couples to multiple G proteins to mediate several diverse intracellular signaling pathways.

Adenylyl Cyclases↗

Differential intracellular signaling of the GalR1 and GalR2 galanin receptor subtypes.

The diverse physiological functions exerted by the neuropeptide galanin may be regulated by multiple G protein-coupled receptor subtypes and intracellular signaling pathways. Three galanin receptor subtypes (GalRs) have been recently cloned, but the G protein coupling profiles of these receptors are not completely understood. We have generated GalR1- and GalR2-expressing Chinese hamster ovary (CHO) cell lines and systematically examined the potential for these two receptors to couple to the Gs, Gi, Go, and Gq proteins. Galanin did not stimulate an increase in cAMP levels in GalR1/CHO or GalR2/CHO cells, suggesting an inability of either receptor to couple to Gs. Galanin inhibited forskolin-stimulated cAMP production in GalR1/CHO cells by 70% and in GalR2/CHO cells by 30%, suggesting a strong coupling of GalR1 to Gi and a more modest coupling between GalR2 and Gi. GalR1 and GalR2 both mediated pertussis toxin-sensitive MAPK activity (2-3-fold). The stimulation mediated by GalR1 was inhibited by expression of the C-terminus of beta-adrenergic receptor kinase (beta ARKct), which specifically inhibits G beta gamma signaling, but was not affected by the protein kinase C (PKC) inhibitor, bis[indolylmaleimide], or cellular depletion of PKC. In contrast, GalR2-mediated MAPK activation was not affected by beta ARKct expression but was abolished by inhibition of PKC activity. The data demonstrate that GalR1 is coupled to a Gibetagamma signaling pathway to mediate MAPK activation. In contrast, GalR2 utilizes a distinct signaling pathway to mediate MAPK activation, which is consistent with Go-mediated MAPK activation in CHO cells. Galanin was unable to stimulate inositol phosphate (IP) accumulation in CHO or COS-7 cells expressing GalR1. In contrast, galanin stimulated a 7-fold increase in IP production in CHO or COS-7 cells expressing GalR2. The GalR2-mediated IP production was not affected by pertussis toxin, suggesting a linkage of GalR2 with Gq/G11. Thus, the GalR1 receptor appears to activate only the Gi pathway. By contrast, GalR2 is capable of stimulating signaling which is consistent with activation of Go, Gq/G11, and Gi. The differential signaling profiles and the tissue distribution patterns of GalR1 and GalR2 may underlie the functional spectra of galanin action mediated by these galanin receptors and regulate the diverse physiological functions of galanin.

Animals↗

Nociceptin (ORL-1) and mu-opioid receptors mediate mitogen-activated protein kinase activation in CHO cells through a Gi-coupled signaling pathway: evidence for distinct mechanisms of agonist-mediated desensitization.

The recently identified 17-amino acid peptide nociceptin (orphanin FQ) is the endogenous ligand for the opioid receptor-like-1 (ORL-1) receptor. A physiologic role for nociceptin (OFQ) activation of the ORL-1 receptor (OFQR) may be to modulate opioid-induced analgesia. The molecular mechanism by which nociceptin (OFQ) and ORL-1 (OFQR) modify opioid-stimulated effects, however, is unclear. Both ORL-1 (OFQR) and opioid receptors mediate pertussis toxin (PTX)-sensitive signal transduction, indicating these receptors are capable of coupling to Gi/Go proteins. This study determines that nociceptin stimulates an intracellular signaling pathway, leading to activation of mitogen-activated protein (MAP) kinase in CHO cells expressing ORL-1 receptor (OFQR). Nociceptin (OFQ)-stimulated MAP kinase activation was inhibited by PTX or by expression of the carboxyl terminus of beta-adrenergic receptor kinase (betaARKct), which specifically blocks Gbetagamma-mediated signaling. Expression of the proline-rich domain of SOS (SOS-PRO), which inhibits SOS interaction with p21ras, also attenuated nociceptin (OFQ)-stimulated MAP kinase activation. The phosphatidylinositol 3-kinase (PI-3K) inhibitors wortmannin and LY294002 reduced nociceptin (OFQ)-stimulated MAP kinase activation, whereas inhibition of protein kinase C (PKC) activity by bisindolylmaleimide I or cellular depletion of PKC had no effect. In a similar manner, in cells expressing mu-opioid receptor, [D-Ala2,N-Me-Phe4,Gly-ol]-enkephalin (DAMGO; a mu-opioid receptor-selective agonist) stimulated PTX-sensitive MAP kinase activation that was inhibited by wortmannin, LY294002, betaARKct expression, or SOS-PRO expression but not affected by inhibition of PKC activity. These results indicate that both ORL-1 (OFQR) and mu-opioid receptors mediate MAP kinase activation via a signaling pathway using the betagamma-subunit of Gi, a PI-3K, and SOS, independent of PKC activity. In cells expressing both ORL-1 (OFQR) and mu-opioid receptors, pretreatment with nociceptin decreased subsequent nociceptin (OFQ)- or DAMGO-stimulated MAP kinase activation. In contrast, pretreatment of cells with DAMGO decreased subsequent DAMGO-stimulated MAP kinase but had no effect on subsequent nociceptin (OFQ)-stimulated MAP kinase activation. These results demonstrate that nociceptin (OFQ) activation of ORL-1 (OFQR) can modulate mu-opioid receptor signaling in a cellular system.

Animals↗

Antepartum management protocol. Timing and mode of delivery in gestational diabetes.

We sought to determine whether strict glycemic control during diabetic pregnancy combined with elective early induction of labor reduces the rate of cesarean delivery and fetal birth trauma. We used a population-based longitudinal design covering three periods corresponding to changes in the management protocol for diabetic pregnancy at our center: 1) 1980-1989: no set level of maternal glycemia, elective cesarean section when estimated fetal weight was 4,500 g or more, and no elective early induction; 2) 1990-1992: desired mean maternal glycemia < or = 5.8 mmol/l, elective cesarean section when estimated fetal weight was 4,000 g or more, and elective early induction at 40 weeks for large-for-gestational-age fetuses; 3) 1993-1995: desired mean maternal glycemia < or = 5.3 mmol/l, elective cesarean section when estimated fetal weight was 4,000 g or more, and elective early induction at 38 weeks for large-for-gestational-age fetuses. Outcome of diabetic pregnancies was compared for the three periods, relative to that of the normal population. There was a gradual, constant, and significant decline in the incidence of macrosomia (17.9, 14.9, and 8.8%, respectively; P < 0.05) and large-for-gestational-age fetuses (23.6, 21.0, and 11.7%; P < 0.05) coupled with a gradual, nonsignificant decrease in cesarean deliveries (20.6, 18.4, and 16.2%) and in cases of shoulder dystocia (1.5, 1.2, and 0.6%), to rates close to those of the normal population. Our data show that maintaining strict control of maternal diabetes and adhering to an active management protocol for early elective delivery based on the estimated fetal weight have a significant effect on reducing the rate of macrosomia, thereby affecting the incidence of both traumatic births and cesarean deliveries.

Blood Glucose↗

Gastrin-releasing peptide receptor signaling resulting in growth inhibition.

We demonstrate that gastrin-releasing peptide (GRP) can inhibit the proliferation of human immortal nontumorigenic (184-B5) mammary epithelial cells ectopically expressing the human GRP receptor. Growth of Balb 3T3 cells ectopically expressing relatively high levels of the GRP receptor was also inhibited by GRP; however, growth of transfectants expressing lower levels of the receptor was not inhibited. Compared with Balb 3T3 cells, mammary epithelial cells could be rendered sensitive to growth inhibition by GRP by the expression of fewer GRP receptors. GRP also stimulated DNA synthesis in quiescent, serum-starved Balb 3T3 transfectants. In clones that were sensitive to growth inhibition by GRP by virtue of their expression of relatively high levels of the GRP receptor, the dose-response curve of GRP-stimulated DNA synthesis was bell shaped. This is consistent with our conclusion that the growth-inhibiting activity of GRP required the activation of a relatively large pool of receptors in Balb 3T3 cells. Significantly, prostaglandin H synthase inhibitors, which block the production of prostaglandins from arachidonic acid, reduced GRP-inhibitory effects on DNA synthesis. We also compared a number of GRP-stimulated signaling pathways in Balb 3T3 clones that were sensitive or insensitive to growth inhibition by GRP, including cAMP formation, phospholipase C activation, calcium mobilization, and arachidonic acid formation. Taken together, these results demonstrate a novel GRP receptor-coupled signal pathway promoting growth inhibition in which prostaglandin H synthase plays a significant role.

3T3 Cells↗

Detection of immunoglobulin A anticardiolipin antibodies in cervical mucus from in vitro fertilization patients and fertile women.

OBJECTIVE: To identify and quantify antiphospholipid autoantibodies of the immunoglobulin (Ig) A isotype in cervical mucus obtained from IVF patients and fertile controls. DESIGN: The study was performed prospectively. Blood and cervical mucus samples were obtained from patients undergoing IVF treatment (n = 27) at the time of expected E2 peak, before administering hCG. Control samples were taken from fertile women (n = 16) around the time of ovulation during a spontaneous nonstimulated menstrual cycle. Anticardiolipin activity was tested using ELISA. SETTING: Infertility and IVF unit of an academic tertiary referral medical center and university-based basic research laboratory. RESULTS: Forty-eight percent (13/27) of the IVF patients and 43.8% (7/16) of the fertile controls exhibited anticardiolipin IgA activity in aspirated cervical mucus. The mean activity measured for the positive cases was similar in both groups. This activity was higher than that measured in peripheral blood of the women studied. No difference was noted between infertile patients undergoing IVF treatment and fertile women in this respect. CONCLUSIONS: In this preliminary work, we demonstrated for the first time anticardiolipin IgA activity in human cervical mucus. These observations have to be substantiated by larger scaled studies to assess their possible clinical significance.

Adult↗

Abnormal oral sensory perception in patients with a history of anorexia nervosa and the relationship between physiological and psychological improvement in this disease.

14 patients with a history of anorexia nervosa (AN) (mean duration 7.1 years) were divided into two groups according to whether they were still amenorrheic (group I, n = 6) at a significantly lower body weight or at normal stable weight with eumenorrhea (group II, n = 8); 26 age-matched students served as the control group. Psychological testing included the Eating Disorder Inventory (EDI), shadow silhouette size rating, and a new test of oral appreciation of different sized cubes. In groups I and II, oral misperception of medium and large sizes was significantly greater than visual-tactile appreciation; and all cube sizes, however presented, were overexaggerated when compared to the controls. Group II subjects had EDI scores and ideal body weight choices similar to those of group I. Thus, in AN, in addition to visual misperception, there may be a more generalized problem of size conceptualization including oral appreciation. These findings also suggest that improvement in body weight and menstrual function, as in group II, does not necessarily imply psychological recovery in AN.

Adult↗

Effect of three A-ring analogs of 1 alpha,25-dihydroxyvitamin D3 on 25-OH-D3-1 alpha-hydroxylase in isolated mitochondria and on 25-hydroxyvitamin D3 metabolism in cultured kidney cells.

Three A-ring analogs of 1 alpha,25-dihydroxyvitamin D3 (1,25(OH)2D3)--2-nor-1,3-seco-1,25(OH)2D3 (2-nor analog), 2-oxa-3-deoxy-25-OH-D3 (2-oxa analog), and A-homo-3-deoxy-3,3-dimethyl-2,4-dioxa-25-OH-D3 (A-homo analog)--were tested for their ability to inhibit 25-OH-D3-1 alpha-hydroxylase (1 alpha-hydroxylase) in isolated mitochondria and to alter 25-OH-D3 metabolism in cultured chick kidney cells. The 2-nor and 2-oxa analogs were relatively potent (Kis of 60 and 30 nM, respectively, compared with 170 nM for 1,25(OH)2D3), whereas the A-homo analog was completely ineffective in inhibiting 1 alpha-hydroxylase activity. In contrast, all three analogs were able to repress 1 alpha-hydroxylase and induce 24-hydroxylase activity in cultured chick kidney cells, suggesting that this process is not one of direct action in the mitochondria, but is more likely to be a receptor-mediated one.

25-Hydroxyvitamin D3 1-alpha-Hydroxylase↗