Neural predictors of 12-month weight loss outcomes following bariatric surgery.

BACKGROUND/OBJECTIVES: Despite the effectiveness of bariatric surgery, there is still substantial variability in long-term weight outcomes and few factors with predictive power to explain this variability. Neuroimaging may provide a novel biomarker with utility beyond other commonly used variables in bariatric surgery trials to improve prediction of long-term weight-loss outcomes. The purpose of this study was to evaluate the effects of sleeve gastrectomy (SG) on reward and cognitive control circuitry postsurgery and determine the extent to which baseline brain activity predicts weight loss at 12-month postsurgery. SUBJECTS/METHODS: Using a longitudinal design, behavioral, hormone and neuroimaging data (during a desire for palatable food regulation paradigm) were collected from 18 patients undergoing SG at baseline (<1 month prior) and 12-month post-SG. RESULTS: SG patients lost an average of 29.0% of their weight (percentage of total weight loss (%TWL)) at 12-month post-SG, with significant variability (range: 16.0-43.5%). Maladaptive eating behaviors (uncontrolled, emotional and externally cued eating) improved (P<0.01), in parallel with reductions in fasting hormones (acyl ghrelin, leptin, glucose, insulin; P<0.05). Brain activity in the nucleus accumbens (NAcc), caudate, pallidum and amygdala during desire for palatable food enhancement vs regulation decreased from baseline to 12 months (P (family-wise error (FWE))<0.05). Dorsolateral and dorsomedial prefrontal cortex activity during desire for palatable food regulation (vs enhancement) increased from baseline to 12 months (P(FWE)<0.05). Baseline activity in the NAcc and hypothalamus during desire for palatable food enhancement was significantly predictive of %TWL at 12 months (P (FWE)<0.05), superior to behavioral and hormone predictors, which did not significantly predict %TWL (P>0.10). Using stepwise linear regression, left NAcc activity accounted for 54% of the explained variance in %TWL at 12 months. CONCLUSIONS: Consistent with previous obesity studies, reward-related neural circuit activity may serve as an objective, relatively robust predictor of postsurgery weight loss. Replication in larger studies is necessary to determine true effect sizes for outcome prediction.

Transforming growth factor-beta stimulates mouse blastocyst outgrowth through a mechanism involving parathyroid hormone-related protein.

The goals of this study were 1) to compare the effects of transforming growth factor-beta (TGF-beta) and parathyroid hormone-related protein (PTHrP) on mouse blastocyst attachment and outgrowth in vitro, 2) to determine whether TGF-beta acts through a mechanism involving PTHrP, 3) to examine effects of PTHrP on preimplantation mouse embryo development, and 4) to determine the pattern of expression of PTHrP protein in the uterus of the mouse during early gestation. In the first set of experiments, hatched blastocysts were placed in fibronectin-coated wells. Cultures were treated with PTHrP or TGF-beta1 and assessed at 24, 48, and 72 h for attachment and surface area of blastocyst outgrowth. Results showed that both PTHrP and TGF-beta1 increased blastocyst outgrowth significantly. A PTHrP-neutralizing antibody blocked the stimulatory effect of both PTHrP and TGF-beta1, suggesting that TGF-beta1 acts to increase endogenous production of PTHrP by the blastocyst. Immunoassay of conditioned medium from blastocysts treated with either TGF-beta1 or PTHrP 1-34 confirmed a 3- to 4-fold increase in levels of PTHrP 1-141. In the second series of experiments, pronuclear zygotes were cultured in various concentrations of PTHrP for 96 h. Blastocysts then were subjected to differential fluorescent staining of inner cell mass and trophectoderm cells. Treatment of mouse embryos with the various concentrations of PTHrP altered neither the number developing to the blastocyst stage nor the number of inner cell mass or trophectoderm cells in the resulting blastocysts. In the third experiment, pregnant mice were killed at Days 3, 4, 5, 6, and 7 of gestation, and uterine horns were processed for immunohistochemistry. Uterine sections were stained with antibodies to PTHrP, desmin, and laminin. On Days 3, 4, and 5, uterine luminal and glandular epithelial cells stained intensely for PTHrP, while stromal cells were negative. By Days 6 and 7, decidualized stromal cells stained positively for PTHrP, desmin, and laminin. These results support the hypothesis that TGF-beta and PTHrP play an important role in the process of implantation.

Quantitation of HIV-1-specific IgG, IgA, and IgM antibodies in human genital tract secretions.

A quantitative enzyme-linked immunosorbent assay (ELISA) has been developed for the quantitation of HIV-1-specific immunoglobulins of the IgG, IgA, and IgM isotypes and was used to assess HIV-specific antibody concentrations in semen and cervicovaginal lavage (CVL) specimens. Immunoglobulin isotype concentrations were assessed by capture ELISA using immunoglobulin isotype-specific secondary antibodies and commercial IgG, IgA, and IgM standards. HIV-1 antibody detection kits (Abbott Laboratories, North Chicago, IL, U.S.A.) and immunoglobulin isotype-specific secondary antibodies were used to obtain optical density (OD) units for HIV-1-specific antibodies of each isotype. To determine the antibody concentrations from the OD values, ODs were compared with those from HIV-1-specific antibody isotype standards of known concentration obtained from CVL specimens of seropositive women by affinity binding to HIV antigen-coated beads and acid elution. The sensitivity of the HIV-1-specific immunoglobulin assay was 0.01 microg/ml for IgG, 0.04 microg/ml for IgA, and 0.08 microg/ml for IgM. The interassay coefficient of variation for the different immunoglobulin isotypes varied from 5% to 33%, being lowest for IgG and highest for IgM. HIV-1-specific antibodies were detected in all semen samples from seropositive men in concentrations ranging from 53 to 261 microg/ml. Thirteen of 14 samples contained high levels of HIV-1-specific IgG antibodies (22-72 microg/ml) whereas 10 of the 14 (71%) semen samples contained detectable but lower levels of HIV-1-specific IgA and IgM (maximum level: 3.7 microg/ml for IgA and 14.8 microg/ml for IgM). HIV-1-specific IgG antibodies were detected in all 196 CVL samples from seropositive women in concentrations ranging from 0.01 to 47 microg/ml, whereas only 16 women (8%) had IgA levels above the detectable limit (range, 1.4-3.9 microg/ml), and only eight women (4%) had IgM levels above the detectable limit (range, 1.8-8.6 microg/ml). None of 80 low-risk women or 20 low-risk men (negative controls) had detectable levels of HIV-1-specific antibodies in genital tract specimens. HIV-1-specific IgG levels in CVL specimens of seropositive women were significantly higher in individuals who had acquired HIV through heterosexual transmission, and a majority of women with elevated levels of HIV-specific IgA isotype antibodies in CVL samples had evidence of genital tract inflammation (>10[4] polymorphonuclear leukocytes [PMNs]/ml). Use of this quantitative method will facilitate direct comparison of data obtained within and among laboratories and enable further research on factors affecting antibody levels in genital tract secretions and their effects on HIV-1 transmission.

Detection of semen in cervicovaginal secretions.

Sperm were detectable by microscopic examination in human cervicovaginal lavage (CVL) specimens < or = 8 h after intercourse, whereas an enzyme-linked immunosorbent assay using the monoclonal antibody MHS-5, specific for a seminal vesicle antigen present in semen detected semen at a concentration of 1:2,500,000 (0.00004%) in CVL specimens and was positive < or = 24 h following unprotected intercourse. We recommend the routine use of semen detection assays to reduce false-positive results attributable to semen contamination in assays of pathogens, antibodies, or other factors in cervicovaginal secretions.

Effects of growth factors and growth factor-extracellular matrix interactions on mouse trophoblast outgrowth in vitro.

A variety of cell types at the blastocyst implantation site produce growth factors that could play important role(s) in the implantation process. Recent evidence indicates that decidual cells and/or embryos produce transforming growth factor-alpha (TGF-alpha), epidermal growth factor (EGF), platelet-derived growth factor (PDGF), fibroblast growth factor (FGF), and colony-stimulating factor (CSF-1). Furthermore, receptors for EGF, PDGF, and CSF-1 have been detected on embryonic and trophoblastic cells. The purpose of this study was to investigate the effects of these growth factors and possibly growth factor-extracellular matrix interactions on mouse blastocyst attachment and trophoblast outgrowth in vitro. Various dilutions of the growth factors TGF-alpha, EGF, PDGF, FGF, and CSF-1 were added to cultures of 5-day-old hatched blastocysts in fibronectin-coated plastic wells. Blastocysts were scored for attachment, trophoblast outgrowth, and surface area at 24, 48, and 72 h. Each of these growth factors significantly enhanced trophoblast outgrowth, and a cocktail containing all of the growth factors had a significantly stronger effect. PDGF and FGF, but no other growth factors, also enhanced trophoblast outgrowth following pulsatile incubation with the fibronectin matrix coating of the culture wells, indicating that interactions between these growth factors and extracellular matrix elements could influence implantation. This study suggests that various growth factors may play an important role in the implantation process, that synergistic effects may be obtained by combinations of growth factors, and that interactions between certain growth factors and extracellular matrix elements may be significant.(ABSTRACT TRUNCATED AT 250 WORDS)

Cytokines and growth factors in implantation.

A variety of cell types at the blastocyst implantation site produce cytokines and growth factors that could play an important role in the implantation process. Furthermore, receptors for cytokines and growth factors have been detected on embryonic and trophoblastic cells. The purpose of the article is to review the published literature on the effect of cytokines and growth factors on implantation events, and to present recent data from our laboratory on effects of growth factors and cytokines on mouse blastocyst implantation events in vitro.

Antifertility effects of antisperm cell-mediated immunity in mice.

C57BL/6 female mice were immunized with allogeneic (DBA/2) sperm in Freund's adjuvant either subcutaneously (s.c.), transcervically into the uterine lumen (i.u.), or with a combination of s.c. and i.u. immunization approaches. Control mice received DBA/2 lymphocytes, human erythrocytes or saline in adjuvant using the same immunization protocols. Immunization with sperm or control cells in adjuvant exclusively by s.c. or i.u. approaches did not affect subsequent fertility, although sperm-injected mice from both protocols had high titers of circulating antisperm antibodies. In contrast, mice that were immunized with sperm in adjuvant by a combination of s.c. and i.u. injections demonstrated significant reductions in fertilization rate and number of viable fetuses and an increased rate of fetal resorption when compared with non-immunized and control-immunized mice. Mice receiving sperm by the s.c./i.u. protocol had high titers of antisperm antibodies and a marked infiltration of T lymphocytes and macrophages into the uterine endometrium. To determine whether cellular immune mechanisms contributed to the infertility effect, T lymphocytes from spleens and pelvic lymph nodes of s.c./i.u. sperm-immunized mice and non-immunized mice were passively transferred to naive syngeneic female recipients which were subsequently mated. The total number of fetuses on day 15 of pregnancy was significantly reduced in mice receiving T-lymphocytes from sperm-immunized mice and a significant increase in fetal resorption sites was also observed. These mice did not have detectable titers of circulating antisperm antibodies, but had a significant infiltration of CD4+ T lymphocytes and macrophages in the uterine epithelium and endometrium. These data indicate that intrauterine antisperm cell-mediated immunity can be induced in mice by a combination of systemic and intrauterine immunizations and provide evidence for the existence of reproductive tract mucosal antisperm cellular immune responses that adversely affect fertility and pregnancy.

The effects of soluble products of activated lymphocytes and macrophages on blastocyst implantation events in vitro.

The purpose of this study was to investigate the effects of soluble products of activated lymphocytes and macrophages on mouse blastocyst attachment and trophoblast outgrowth in vitro. Hatched blastocysts were incubated with medium alone, supernatant fluids from mixed lymphocyte cultures (MLC), and with individual human and murine lymphokines and monokines in fibronectin-coated wells. Cultures were assessed at 24, 48, and 72 h for blastocyst attachment and trophoblast outgrowth. Both human and murine MLC supernatant fluids significantly enhanced trophoblast outgrowth in vitro. The cytokine, interleukin-1 beta (Il-1 beta), at a concentration of 10(3) U/ml, inhibited blastocyst attachment but significantly enhanced trophoblast outgrowth of attached blastocysts. Granulocyte, macrophage-colony-stimulating factor (GM-CSF) at a concentration of 250 U/ml significantly inhibited blastocyst attachment, while gamma interferon (gamma-IFN) at a concentration of 2.5 x 10(3) U/ml significantly inhibited trophoblast outgrowth and caused degenerative morphological changes in these cells. The results of this study indicate that products of activated immune cells may either facilitate or impede implantation events depending on the types of predominant cytokines present, their concentration(s), and the timing of their secretion relative to embryonic development.

Leukocytospermia is associated with poor semen quality.

Semen samples from 179 infertility patients were analyzed for type and number of white blood cells (WBC) by a combination of immunologic techniques. Forty-one (23%) had more than 10(6) WBC/mL semen (leukocytospermia). Semen parameters in patients with less than 10(6) WBC/mL were similar to those of 15 fertile donors. In contrast, the leukocytospermic group had significant reductions in total sperm number, percent sperm motility, sperm velocity, motility index, and total number of motile sperm. Patients with high concentrations of monocytes/macrophages (greater than 5 X 10(5)/mL; n = 27) had significantly reduced ejaculate volume; patients with high numbers of T lymphocytes (greater than 10(5)/mL; n = 19) had a significant reduction in sperm velocity; and patients with high levels of granulocyte elastase in semen (greater than 1,000 ng/mL; n = 26) had significant reductions in ejaculate volume, total sperm number, and total motile sperm number. There was no correlation between the presence of antisperm antibodies and leukocytospermia. Our data suggest that leukocytospermia may occur frequently in male infertility patients and show that elevated levels of WBC in semen are associated with poor semen quality. This provides further rationale for white blood cell testing in semen of male infertility patients, since antibiotic or anti-inflammatory therapy may be helpful in appropriately selected cases.

Variables affecting toxicity of human sera in mouse embryo cultures.

It has been reported that sera from women with reproductive disorders can inhibit mouse embryo development. While performing tests on this subject in our laboratory, two unexpected variables were identified that can influence the effect of human serum on mouse embryo cultures. In a standard embryo culture system in which heat-inactivated sera (10% final concentration) were added to two-cell mouse embryos and percentage blastocyst development was scored after 4 days, sera that had been collected into standard clinical Monoject blood collection red-stopper tubes were significantly more embryotoxic than sera collected from the same subjects into 15-ml Falcon centrifuge tubes (P less than 0.005). Furthermore, we observed that sera from laboratory personnel that worked with mice often inhibited mouse embryo development. To study this effect further, sera were collected from five fertile individuals who were routinely exposed to mice and from fertile women with no previous exposure to rodents. Sera from the mouse-exposed group were significantly more inhibitory than sera from the nonexposed control group (P less than 0.005). The effect was observed in the ammonium sulfate-precipitated immunoglobulin fraction of the mouse-exposed group's sera, and high titers of antibodies reactive with mouse spleen cells were detected in sera and immunoglobulin fractions from this group by enzyme-linked immunosorbent assay (ELISA). Embryotoxic activity was neutralized by absorption with mouse lymphocytes, but not with rabbit or human lymphocytes, suggesting that a heterophilic antimouse antibody is the factor responsible for this effect. These data emphasize the importance of including extensive controls in experiments addressing toxic effects of human sera on mouse embryos.

Products of activated lymphocytes and macrophages inhibit mouse embryo development in vitro.

The effects of activated leukocyte products on embryonic development were assessed by adding mouse and human leukocyte culture supernatants and purified murine and human lymphokines and monokines to mouse embryos in tissue culture. Supernatants from mitogen-stimulated and mixed lymphocyte cultures arrested embryonic development at the two-cell to morula stage. Of a panel of six individual lymphokines and monokines tested for effects in this system, both murine and human forms of the lymphokines colony-stimulating factor, interferon-gamma, and human B cell growth factor significantly arrested embryonic development over a wide concentration range. The monokines, interleukin 1 and tumor necrosis factor, also had significant effects but only at high doses. These results indicate that products of activated lymphocytes and macrophages can have detrimental effects on preimplantation embryos. Early abortion could result from local (intrauterine) production of such embryotoxic factors by activated lymphocytes and macrophages in response to stimulation by microorganisms or reproductive tissue antigens.

Effects of soluble products of activated lymphocytes and macrophages (lymphokines and monokines) on human sperm motion parameters.

Experiments were conducted to evaluate the effects of supernatants from activated leukocyte cultures and purified lymphokine and monokine preparations on sperm motion. An automated semen analyzer was used to obtain accurate measurements of several parameters of sperm motion. Supernatants from activated peripheral blood leukocyte cultures significantly decreased sperm motility. In studies of effects of individual lymphokines and monokines, significant antimotility effects were observed when spermatozoa were incubated with the lymphokine gamma-interferon and the monokine tumor necrosis factor. Subnormal fertility may result from defective sperm function caused by lymphokines and monokines elaborated by activated lymphocytes and macrophages residing in the reproductive tracts of infertile men and women.