Circulating leptin and ghrelin are differentially influenced by estrogen/progestin therapy and raloxifene

BACKGROUND: Leptin and ghrelin are increasingly being recognized as cardiotropic hormones, promoting or inhibiting the atherosclerotic process, respectively. Apoptosis may be one pathway through which the actions of these hormones are mediated. Sex hormones are reported to influence the secretion and action of ghrelin and leptin. OBJECTIVE: To evaluate (1) the association of circulating ghrelin and leptin with selected markers of receptor-mediated apoptosis and (2) the effect of estrogen monotherapy, low dose estrogen-progestin therapy, tibolone and raloxifene on serum ghrelin and leptin in healthy postmenopausal women. METHODS: Eighty eight postmenopausal women aged 44-62 years were randomly allocated to daily (1) conjugated equine estrogens 0.625 mg (CEE), (2) 17beta-estradiol 1mg plus norethisterone acetate 0.5 mg (E(2)/NETA), (3) tibolone 2.5mg, (4) raloxifene HCl 60 mg or (5) no treatment. Serum markers of apoptosis sFas, Fas-ligand (Fas-L) and caspase-1 were measured at baseline. Serum leptin and ghrelin were measured at baseline and at 3 months. RESULTS: Body Mass Index (BMI) and estradiol levels correlated positively, while FSH correlated negatively with serum leptin (BMI: r=0.646, p=0.005, estradiol: r=0.432, p=0.001, FSH: r=-0.401, p=0.002). Insulin levels associated positively with circulating leptin (r=0.394, p=0.011) and negatively with circulating ghrelin (r=-0.401, p=0.009). Serum leptin decreased significantly in E2/NETA group (baseline: 2.882+/-0.76 ng/ml, 3 months: 2.687+/-0.66 ng/ml, p=0.043), while it increased significantly in the raloxifene group (baseline: 2.671+/-0.54 ng/ml, 3 months: 2.839+/-0.47 ng/ml). Ghrelin levels decreased significantly only in the raloxifene group (baseline: 1634+/-592 pg/ml, 3 months: 1408+/-534 pg/ml). CONCLUSION: Apoptosis may be a pathway through which leptin exerts a pro-atherogenic effect. Low dose HT may act cardioprotectively by decreasing leptin levels in healthy recently menopaused women.     

Serum leptin levels in postmenopausal women: effects of transdermal hormone replacement therapy

OBJECTIVE: To evaluate serum leptin levels in postmenopausal women who are receiving hormone replacement therapy (HRT) and postmenopausal women who are not receiving HRT with similar body mass index (BMI) to determine whether estrogens exert effects on leptin secretion. DESIGN: Cross-sectional, prospective study comparing serum leptin levels in premenopausal women, postmenopausal women who were not receiving HRT (group A), and postmenopausal women who were receiving HRT (group B). RESULTS: Serum leptin levels were significantly higher in group A in comparison to group B and control women (15.82 +/- 6.6 ng/ml, 8.14 +/- 4.17 ng/ml, and 10.12 +/- 5.48 ng/ml, respectively; p < 0.05). Total fat mass (FM) was found to be significantly higher in untreated postmenopausal women in comparison to the other two groups (22.66 +/- 2.79 kg vs. 19.14 +/- 3.39 kg vs. 18.98 +/- 3.82 kg; p < 0.05). No significant difference was observed in weight, height, BMI, blood pressure, or glucose levels among the three groups. A linear correlation between BMI and serum leptin levels as well as between total FM and serum leptin levels was observed in all groups. No correlation was found between serum leptin levels and months from menopause and months of HRT. CONCLUSIONS: Our results show that serum leptin is increased in untreated postmenopausal women, possibly as a consequence of the increase in FM, and that HRT reduces serum leptin levels to premenopausal values. These data need further investigation by a broader longitudinal study.     

Leptin production in pre- and postmenopausal women

OBJECTIVES: To investigate the differences in leptin production between pre- and postmenopausal women. METHODS: Subjects were 75 pre- and 75 postmenopausal women. Age, height, weight, and body mass index (BMI, wt/ht(2)) were recorded. Serum leptin levels were measured by RIA. Total body fat mass and percentage of body fat mass were measured by whole-body scanning with dual-energy X-ray absorptiometry. Serum leptin levels, the ratio of serum leptin levels to total body fat mass (leptin-fat mass ratio), baseline characteristics, and anthropometric variables were compared between the two groups. In all subjects (n=150), relationship of serum leptin levels with menopausal status (pre- and postmenopause) was investigated by univariate and multiple regression analysis. RESULTS: Serum leptin levels in premenopausal women 8.4+/-4.8 ng/ml, which did not differ from that in postmenopausal women (9.2+/-7.1 ng/ml). Total body fat mass, percentage of body fat mass, and BMI did not differ between the two groups. Leptin-fat mass ratio in premenopausal women was 0.43+/-0.17 ng/ml/kg, which did not differ from that in postmenopausal women (0.44+/-0.24 ng/ml/kg). On both univariate and multiple regression analysis, serum leptin levels were not correlated with menopausal status. CONCLUSIONS: Menopausal status does not have a significant impact on leptin production.     

Serum leptin levels in patients with rheumatoid arthritis are correlated with body mass index

Leptin, a 16-kD protein of the ob gene product, is produced by adipose tissue and acts on the hypothalamus to suppress neuropeptide Y secretion which reduces the appetite. It has been demonstrated that serum leptin levels in healthy subjects are correlated with body mass index(BMI). Leptin is also produced by stimulation of inflammatory cytokines such as tumor necrosis factor(TNF)-alpha and interleukin(IL)-1. Rheumatoid arthritis(RA) is one of the chronic inflammatory diseases in which high serum cytokine levels are noted. In this study, we measured serum leptin levels(s-leptin) by RIA kit in 20 healthy subjects (10 males and 10 females) and 49 RA patients(14 males and 35 females) and the markers for joint inflammation such as ESR and CRP. There was no difference in s-leptin between controls(male: mean +/- SD = 5.6 +/- 3.0 ng/ml; female: 7.8 +/- 4.5 ng/ml) and RA patients(male: 4.9 +/- 3.2 ng/ml; female: 9.1 +/- 5.7 ng/ml). S-leptin was correlated with BMI in both healthy subjects and RA patients. However, there was no correlation between s-leptin and the values of ESR or CRP, disease stages in RA patients. In conclusion, s-leptin in RA patients reflects BMI but not joint inflammation.     

Oestradiol plus progesterone treatment increases serum leptin concentrations in normal women

BACKGROUND: Previous studies have alluded to a role for both oestradiol and progesterone in the secretion of leptin from fat cells in the human, although direct evidence has yet to be obtained. The study aim was to assess serum leptin concentrations in normally cycling women receiving exogenous oestradiol and progesterone. METHODS: Normally cycling women were investigated in an untreated spontaneous cycle (control, n = 10), a cycle treated with oestradiol (oestradiol cycle, n = 10) and a cycle treated with oestradiol plus progesterone (oestradiol+progesterone cycle, n = 6). Oestradiol was given to the women through skin patches on cycle days 2, 3 and 4, and progesterone intravaginally on cycle days 3, 4 and 5. Serum concentrations of leptin, oestradiol, progesterone, FSH and LH were measured in daily blood samples. RESULTS: During the treatment, serum oestradiol and progesterone concentrations increased significantly. In the oestradiol cycles, leptin concentrations were not affected by treatment and did not differ from those in controls. In the oestradiol+progesterone cycles, leptin concentrations (mean +/- SEM) increased in all women from cycle day 3 (8.6 +/- 1.1 ng/ml) to days 5 (12.2 +/- 1.8 ng/ml, P < 0.01) and 6 (11.9 +/- 2.0, P < 0.05), and were at these points significantly higher than in the control cycles (P < 0.05). The mean percentage increase from day 3 to the peak concentration on days 5 or 6 was 62.6 +/- 6.8%. Leptin concentrations returned to the pretreatment value on day 7, together with the concentrations of oestradiol and progesterone. In the oestradiol+progesterone cycles, leptin concentrations correlated significantly with oestradiol and progesterone concentrations, but not with FSH and LH concentrations. CONCLUSIONS: These results show, for the first time, that leptin secretion can be stimulated in women by the administration of oestradiol plus progesterone. This may explain the increased concentrations of leptin during the luteal phase of the normal menstrual cycle.     

Engraftment of primates with G-CSF mobilized peripheral blood CD34+ progenitor cells expanded in G-CSF, SCF and MGDF decreases the duration and severity of neutropenia.

We used a primate model of autologous peripheral blood progenitor cell (PBPC) transplantation to study the effect of in vitro expansion on committed progenitor cell engraftment and marrow recovery after transplantation. Four groups of baboons were transplanted with enriched autologous CD34+ PBPC collected by apheresis after five days of G-CSF administration (100 microg/kg/day). Groups I and III were transplanted with cryopreserved CD34+ PBPC and Groups II and IV were transplanted with CD34+ PBPC that had been cultured for 10 days in Amgen-defined (serum free) medium and stimulated with G-CSF, megakaryocyte growth and development factor (MGDF), and stem cell factor each at 100 etag/ml. Group III and IV animals were administered G-CSF (100 microg/kg/day) and MGDF (25 microg/kg/day) after transplant, while animals in Groups I and II were not. For the cultured CD34+ PBPC from groups II and IV, the total cell numbers expanded 14.4 +/- 8.3 and 4.0 +/- 0.7-fold, respectively, and CFU-GM expanded 7.2 +/- 0.3 and 8.0 +/- 0.4-fold, respectively. All animals engrafted. If no growth factor support was given after transplant (Groups II and I), the recovery of WBC and platelet production after transplant was prolonged if cells had been cultured prior to transplant (Group II). Administration of post-transplant G-CSF and MGDF shortened the period of neutropenia (ANC < 500/microL) from 13 +/- 4 (Group I) to 10 +/- 4 (Group III) days for animals transplanted with non-expanded CD34+ PBPC. For animals transplanted with ex vivo-expanded CD34+ PBPC, post-transplant administration of G-CSF and MGDF shortened the duration of neutropenia from 14 +/- 2 (Group II) to 3 +/- 4 (Group IV) days. Recovery of platelet production was slower in all animals transplanted with expanded CD34+ PBPC regardless of post-transplant growth factor administration. Progenitor cells generated in vitro can contribute to early engraftment and mitigate neutropenia when growth factor support is administered post-transplant. Thrombocytopenia was not decreased despite evidence of expansion of megakaryocytes in cultured CD34+ populations.     

Antiestrogenic tamoxifen and toremifene increase serum leptin levels in postmenopausal breast cancer patients

OBJECTIVES: Because estrogens stimulate the synthesis and release of leptin in the adipocytes, the effect of antiestrogens on the circulating leptin levels were studied. METHODS: Thirty postmenopausal patients with breast cancer were randomized to start either with tamoxifen (20 mg/day, n=15) or toremifene (40 mg/day, n=15), and the patients were examined and serum leptin concentrations measured before the study and at 6 and 12 months. RESULTS: The baseline leptin concentrations ranged from 4.4 to 60.0 microg/l (15.3+/-13.1 microg/l, mean+/-S.D.), and it correlated positively with the body mass index (BMI) of the subjects (r=0.73, P=0.0001). Taking as a whole the antiestrogen regimen was associated with elevated leptin levels at 6 months (19.5+/-13.8 microg/l, P=0.0001) but no excess increase in leptin levels were seen at 12 months (20.9+/-13.5 microg/l, NS). Subgroup analysis showed no difference between the effects of tamoxifen or toremifene on leptin. BMI increased in 21 women (from 26.2+/-4.3 to 27.3+/-4.8 kg/m2, P=0.0001) at 6 months, but not after that; in nine women BMI did not change. There was no significant correlation between the change in leptin levels and the change in BMI in either group implying that antiestrogens may specifically stimulate leptin production. CONCLUSIONS: Antiestrogens may stimulate the synthesis and release of leptin in the adipocytes. This effect of antiestrogens resembles the effect of estrogen and consequently stimulation of leptin production can be added to the estrogenic effects of antiestrogens.     

Stem cells expressing homing receptors could be expanded from cryopreserved and unselected cord blood

We assessed the cytokine combinations that are best for ex vivo expansion of cord blood (CB) and the increment for cell numbers of nucleated cells, as well as stem cells expressing homing receptors, by an ex vivo expansion of cryopreserved and unselected CB. Frozen leukocyte concentrates (LC) from CB were thawed and cultured at a concentration of 1 x 10(5)/mL in media supplemented with a combination of SCF (20 ng/mL)+TPO (50 ng/mL)+FL (50 ng/mL)+/-IL-6 (20 ng/mL)+/-G-CSF (20 ng/mL). After culturing for 14 days, the expansion folds of cell numbers were as follows: TNC 22.3+/-7.8 approximately 26.3+/-4.9, CFU-GM 4.7+/-5.1 approximately 11.7+/-2.6, CD34+CD38- cell 214.0+/-251.9 approximately 464.1+/-566.1, CD34+CXCR4+ cell 4384.5+/-1664.7 approximately 7087.2+/-4669.3, CD34+VLA4+ cell 1444.3+/-1264.0 approximately 2074.9+/-1537.0, CD34+VLA5+ cell 86.2+/-50.9 approximately 113.2+/-57.1. These results revealed that the number of stem cells expressing homing receptors could be increased by an ex vivo expansion of cryopreserved and unselected CB using 3 cytokines (SCF, TPO, FL) only. Further in vivo studies regarding the engraftment after expansion of the nucleated cells, as well as the stem cells expressing homing receptors will be required.     

Inverse correlation between peritoneal fluid leptin concentrations and the extent of endometriosis

BACKGROUND: The role of leptin in reproductive processes has received increasing attention. Because leptin has intrinsic angiogenic properties, may be induced by inflammatory cytokines and induces matrix metalloproteinases, we examined peritoneal fluid (PF) leptin concentrations in women with endometriosis. METHODS: PF samples were collected from 60 women undergoing laparoscopy for endometriosis, and 18 controls undergoing tubal sterilization. Fifty of the women with endometriosis had received no prior hormonal treatment, while 10 with moderate- severe endometriosis were using GnRH agonists. RESULTS: Women with untreated endometriosis had significantly higher (mean +/- SD) PF leptin levels (34.9 +/- 7.9 ng/ml) than controls (17.9 +/- 4.1 ng/ml; P < 0.001). However, PF leptin levels were inversely correlated with the stage of disease (r = -0.62; P < 0.001). Nevertheless, women with stage III-IV endometriosis maintained significantly higher PF leptin levels (26.3 +/- 4.8 ng/ml; P < 0.001) than controls. Although PF leptin levels were significantly higher in the secretory versus proliferative phase of the menstrual cycle, they remained higher in both phases in women with untreated endometriosis. PF leptin levels in women on GnRH agonists were similar to controls. CONCLUSIONS: PF leptin levels are elevated in women with endometriosis, but inversely correlated with extent of disease. These findings suggest a potential role for leptin in the pathogenesis of peritoneal endometriosis.     

Leptin and leptin-binding activity in women with recurrent miscarriage: correlation with pregnancy outcome

BACKGROUND: Previous studies in humans and mice have suggested the importance of leptin in fetal growth. Recurrent miscarriage may be a result of abnormal placental and/or fetal development and therefore abnormal leptin levels may be associated with this form of pregnancy loss. METHODS: Leptin and leptin-binding activity (LBA) were measured in blood obtained from women who had a history of recurrent miscarriage (n = 53) during weeks 5-6 and 7-8 of pregnancy, and the concentrations were correlated with subsequent pregnancy outcome. RESULTS: Concentrations of leptin ranged from 1.4-62.8 ng/ml, but there was a strong correlation (r = 0.825, P < 0.001) between leptin values at weeks 5-6 and 7-8 in the same woman. Women who subsequently miscarried had significantly lower plasma leptin concentrations on both weeks 5-6 (13.34 +/- 2.1 ng/ml) (P < 0.05) and 7-8 (13.71 +/- 2.4 ng/ml) (P < 0.01) of pregnancy, than women who subsequently had a term birth (22.04 +/- 2.43 ng/ml week 5-6, 24.76 +/- 3.66 ng/ml week 7-8). LBA values ranged from 1-8.5% but there was no significant difference in LBA in blood obtained from women who subsequently miscarried or had a live birth. CONCLUSIONS: The significantly lower concentrations of leptin in women who subsequently miscarried suggest that leptin may play a role in preventing miscarriage. However, as there was a considerable overlap between the values of leptin in women who subsequently miscarried, and those that had a live birth, these measurements are of limited use in the prediction of pregnancy outcome in these women.     

Implication of stem cell factor in human liver regeneration after transplantation and resection

The stem cell factor (SCF), besides regulating hemopoietic stem cells homing and proliferation, has proliferative effects on hepatocytes and may be involved in liver regeneration. We investigate if liver transplantation (LT) and hepatic resection (HR) modify the concentration of soluble SCF (s-SCF) in peripheral blood of 15 LT and 7 HR. s-SCF was measured by ELISA as ng/ml. s-SCF basal levels were higher in LT that in HR (818 +/- 349 vs. 479 +/- 79, p = 0.005). A significant increase of s-SCF, peaking at postoperative day +3, was seen after LT (from 818 +/- 349 to 1212 +/- 461, p = 0.01) and HR (from 479 +/- 79 to 698 +/- 122, p = 0.004). s-SCF peak levels were higher after LT than HR (p = 0.0008). At day +7 s-SCF concentration returned to baseline values. LT have a higher basal s-SCF level than HR. These data show for the first time that liver injury affects s-SCF level and suggest that SCF may be involved also in clinical liver regeneration.     

Characterization of a lineage-negative stem-progenitor cell population optimized for ex vivo expansion and enriched for LTC-IC

Current hematopoietic stem cell transplantation protocols rely heavily upon CD34+ cells to estimate hematopoietic stem and progenitor cell (HSPC) yield. We and others previously reported CD133+ cells to represent a more primitive cell population than their CD34+ counterparts. However, both CD34+ and CD133+ cells still encompass cells at various stages of maturation, possibly impairing long-term marrow engraftment. Recent studies demonstrated that cells lacking CD34 and hematopoietic lineage markers have the potential of reconstituting long-term in vivo hematopoiesis. We report here an optimized, rapid negative-isolation method that depletes umbilical cord blood (UCB) mononucleated cells (MNC) from cells expressing hematopoietic markers (CD45, glycophorin-A, CD38, CD7, CD33, CD56, CD16, CD3, and CD2) and isolates a discrete lineage-negative (Lin-) cell population (0.10% +/- 0.02% MNC, n=12). This primitive Lin- cell population encompassed CD34+/- and CD133+/- HSPC and was also enriched for surface markers involved in HSPC migration, adhesion, and homing to the bone marrow (CD164, CD162, and CXCR4). Moreover, our depletion method resulted in Lin- cells being highly enriched for long-term culture-initiating cells when compared with both CD133+ cells and MNC. Furthermore, over 8 weeks in liquid culture stimulated by a cytokine cocktail optimized for HSPC expansion, TPOFLK (thrombopoietin 10 ng/ml, Flt3 ligand 50 ng/ml, c-Kit ligand 20 ng/ml) Lin- cells underwent slow proliferation but maintained/expanded more primitive HSPC than CD133+ cells. Therefore, our Lin- stem cell offers a promising alternative to current HSPC selection methods. Additionally, this work provides an optimized and well-characterized cell population for expansion of UCB for a wider therapeutic potential, including adult stem cell transplantation.     

CSF versus serum leptin in narcolepsy: is there an effect of hypocretin deficiency?

STUDY OBJECTIVE: To determine if hypocretin deficiency is associated with abnormally low serum leptin levels, a putative cause of increased body mass index in narcoleptics. DESIGN: Cross-sectional controlled study. PARTICIPANTS: Three hundred seventy subjects, including 111 healthy controls, 93 narcoleptic subjects with hypocretin deficiency (cerebrospinal fluid [CSF] hypocretin-1 levels < 110 pg/mL), 72 narcoleptic subjects with normal hypocretin levels, and 89 subjects with other sleep disorders INTERVENTION: After completing the Stanford Sleepiness Inventory, participants underwent spinal taps and blood sampling for measurement of CSF leptin and hypocretin-1 levels, HLA DQB1*0602 phenotyping, and serum leptin and C-reactive protein levels. RESULTS: Serum leptin levels were similar in narcoleptic subjects, whether hypocretin-deficient (13.2 +/- 1.7 ng/mL, mean +/- SEM) or not (13.0 +/- 1.8 ng/mL), controls (10.1 +/- 1.1 ng/mL) and subjects with other sleep disorders (11.5 +/- 1.6 ng/mL). Similarly, the CSF leptin levels and the CSF: serum leptin ratios (an indicator of brain leptin uptake) were not different between groups. Serum and CSF leptin levels were higher in women and in subjects with higher body mass indexes. Leptin brain uptake decreased in women, in the aged, and in more-obese subjects. In contrast with a presumed inhibitory effect of leptin on hypocretin-containing cells, CSF leptin levels tended to correlate positively with CSF hypocretin-1 levels. C-reactive protein was higher (4.2 +/- 0.9 mg/L) in narcoleptic subjects with hypocretin deficiency than in controls (1.4 +/- 0.3 mg/L, p = .0055), a difference still significant after adjustment on confounding factors. DISCUSSION: Our data do not support a role for leptin in mediating increased body mass index in narcolepsy. A moderate but selective increase in C-reactive protein in hypocretin-1 deficient subjects should prompt research on inflammation in narcolepsy.     

Modulation of human cytotrophoblastic leptin secretion by interleukin-1alpha and 17beta-oestradiol and its effect on HCG secretion.

To investigate the role of leptin during pregnancy, we assessed leptin production by pure cultured human cytotrophoblastic cells (CTB), its regulation by cytokines and 17beta-oestradiol and its effects on human chorionic gonadotrophin (HCG) secretion. Purified CTB from first trimester placenta were incubated in duplicates in the presence or absence of cytokines or 17beta-oestradiol. Medium was harvested on day 2 and the culture stopped on day 4. Results were corrected for protein content of each individual well and expressed as percent of controls per day (mean +/- SEM). Basal CTB leptin production was 25.2 +/- 2.6 (ng/mg prot). In comparison with controls, leptin production was stimulated to 320 +/- 16% (P < 0.0001) and 195 +/- 3.2% (P < 0.0004) by 3 and 10 ng/ml of interleukin-1alpha respectively. 17beta-oestradiol 10(-6) to 10(-9) mol/l increased basal leptin production 5-9-fold, while 10(-5) mol/l had no such effect. Basal CTB HCG secretion was 5722 +/- 1055 (mIU/mg prot). There was a dose-dependent leptin-induced increase in HCG secretion (P = 0.0039) reaching a 5-fold increase with a leptin concentration of 1 microg/ml (P < 0.006). Gonadotrophin-releasing hormone (GnRH) 8.5 x 10(-8) mol/l significantly increased HCG secretion to 140 +/- 21% of controls (P = 0.031). Cetrorelix (0.1 microg/ml) inhibited leptin-induced HCG secretion (P = 0.0028).     

Cell cycle activation of peripheral blood stem and progenitor cells expanded ex vivo with SCF, FLT-3 ligand, TPO, and IL-3 results in accelerated granulocyte recovery in a baboon model of autologous transplantation but G0/G1 and S/G2/M graft cell content does not correlate with transplantability

Ex vivo expansion is a new strategy for hematopoietic stem and progenitor cell transplantation based on cytokine-induced amplification to produce grafts of controlled maturity. If the cell cycle position of CD34(+) cells has been reported to govern their engraftment potential, the respective role of stem and progenitor cells in short- and long-term hematopoietic recovery remains debated. Studies focused on long-term engraftment potential suggest impairment when using cultured grafts, but the capacity to sustain short-term recovery is still controverted. The aim of this study was: A) to evaluate the consequences of cell cycle activation on short and long-term engraftment capacity, and B) to determine if cell cycle status of grafts could predict hematopoietic recovery. We showed in a nonhuman primate model of autologous peripheral blood stem and progenitor cell transplantation that cell cycle activation of CD34(+) cells in the presence of stem cell factor + FLT3-ligand + thrombopoietin + interleukin 3 (six days of culture) which induced G1 and S/G2/M cell amplification (G0: 6.1% +/- 2.8%; G0/G1: 64.2% +/- 7.2%; S/G2/M: 30.4% +/- 7.3% respectively of expanded CD34(+) cells on average) resulted in the acceleration of short-term granulocyte recovery. By contrast, G0/G1 and S/G2/M cell content of expanded grafts did not correlate with short- or long-term engraftment.     

Adipokines in children with sleep disordered breathing

STUDY OBJECTIVE: Associations between SDB, the metabolic syndrome, and circulating levels of adipokines have emerged in adults but have not been examined in snoring children, who, in contradistinction to adults, display insulin resistance and lipid abnormalities as a function of adiposity rather than SDB. Therefore, we aimed to examine associations between circulating adipokines levels, insulin resistance, and measures of SDB in children. DESIGN: Prospective study. SETTING: Polysomnographic evaluation and assessment of plasma levels of leptin, adiponectin, resistin, glucose, insulin, and CRP. PARTICIPANTS: 130 children (mean age 8.2 +/- 2.8 years; 39% obese) were studied. MEASUREMENTS AND RESULTS: Log adiponectin levels were lower in obese than nonobese children (3.8 +/- 0.31 vs 4.0 +/- 0.30 corresponding to 8,381.4 +/- 5,841.0 vs 12,853.2 +/- 7,780.2 ng/ml, P < 0.0001) and were inversely correlated with BMI Z scores (r = -0.47, P < 0.0001) but not with log AHI. Log leptin concentrations were higher in the obese group than the nonobese group (4.2 +/- 0.32 vs 3.4 +/- 0.57 corresponding to 19,542.6 +/- 13,643.6 vs 5,875.5 +/- 8,425.7 pg/ml, P < 0.0001), correlated with BMI Z scores (r = 0.64, P < 0.0001), and were significantly lower in children with AHI < or = 1/hr than children with AHI > 1/hr (P = 0.006) and in children with SpO2 nadir > or = 90% than children with SpO2 nadir < 90%, even after controlling for BMI Z score (P < 0.03). No significant differences were found in log resistin levels as a function of obesity or AHI. Significant correlations between log adiponectin levels and log Insulin/Glucose (I/G) ratios (-0.28, P = 0.006) and between log leptin levels and log I/G ratios (r = 0.66, P < 0.0001) emerged. CONCLUSIONS: In close agreement with the absence of a measurable effect of SDB on insulin resistance in children, circulating adipokines levels are primarily attributable to the ponderal index. However, SDB and associated hypoxemia may contribute to the elevation of leptin levels.     

Serum anti-Müllerian hormone dynamics during controlled ovarian hyperstimulation

BACKGROUND: The study aim was to investigate possible changes in serum anti-Müllerian hormone (AMH) levels during controlled ovarian hyperstimulation (COH), and their possible relationship with follicular development and other ovarian hormones. METHODS: A total of 93 women undergoing COH with GnRH agonist and FSH was studied prospectively. Serum levels of AMH, inhibin B, estradiol (E(2)), progesterone, testosterone and Delta(4)-androstenedione were measured when pituitary suppression was achieved (baseline), on days 6 and 8 of FSH treatment, and on the day of hCG. The number of small (<12 mm) and large (>/=12 mm) antral follicles were estimated using ultrasound. RESULTS: Serum AMH levels declined progressively (baseline, 1.21 +/- 0.11 ng/ml; day 6, 0.91 +/- 0.09 ng/ml; day 8, 0.77 +/- 0.08 ng/ml; and day of hCG, 0.53 +/- 0.06 ng/ml), whereas-as expected-the other hormone levels increased during FSH treatment. Throughout COH, serum AMH levels correlated positively with the number of small but not large antral follicles, and with inhibin B serum levels. No correlation between AMH and the other hormones was observed. CONCLUSIONS: Serum AMH levels decline gradually during multiple follicular maturation, probably reflecting the dramatic reduction in the number of small antral follicles due to COH, and confirming the scarce AMH expression by larger follicles.     

Serum leptin levels in asthmatic children treated with an inhaled corticosteroid.

BACKGROUND: Recent observations suggest the presence of an interaction between leptin and the inflammatory system; however, there is no adequate knowledge about the role of leptin in atopic states such as asthma. OBJECTIVES: To evaluate the potential role of leptin in relation to bronchial asthma and inhaled corticosteroid therapy. METHODS: Twenty-three children with mild-to-moderate, newly diagnosed asthma enrolled in this 2-period trial. The control group consisted of 20 age- and sex-matched children. Serum leptin levels were measured in patients at initiation and after 4 weeks of budesonide treatment and were compared with control group measurements. RESULTS: Asthmatic children had higher mean +/- SD serum leptin levels at admission (19.3 +/- 5.1 ng/mL) than after budesonide treatment (10.6 +/- 1.6 ng/mL) and vs control group measurements (9.8 +/- 1.6 ng/mL) (P < .001). There was a significant correlation between serum leptin levels before and after budesonide treatment (r = 0.68; P = .007). Mean +/- SD body mass indices in patients and controls were 16.7 +/- 2.1 and 16.9 +/- 2.6 kg/m2, respectively. Serum leptin levels did not correlate with body mass indices before budesonide treatment in the study group (r = -0.13; P = .65) but correlated well after budesonide treatment (r = 0.58; P = .009) and in the control group (r = 0.65; P = .008). CONCLUSIONS: The role of leptin elevation in children with asthma might be a regulatory mechanism rather than being etiologic, but a question may be raised whether it is possible that leptin may contribute to poor patient outcomes. Further research, both basic and clinical, is essential to explain the exact mechanism.     

Small peptide analogue of SDF-1alpha supports survival of cord blood CD34+ cells in synergy with other cytokines and enhances their ex vivo expansion and engraftment into nonobese diabetic/severe combined immunodeficient mice

The SDF-1/CXCR4 axis has been implicated in the chemotaxis, homing, mobilization, and expansion of hematopoietic stem and progenitor cells. We studied the effects of a SDF-1 peptide analogue CTCE-0214 on the survival of cord blood CD34+ cells in culture, expansion, and engraftment of expanded cells in the nonobese diabetic/severe combined immunodeficient (NOD/SCID) mouse model. Our results demonstrated that CTCE-0214 synergized with thrombopoietin (TPO), stem cell factor (SCF), or flt-3 ligand (FL) on the survival of stem and progenitor cells in culture. Adding CTCE-0214 at a low concentration (0.01 ng/ml) for 4 days together with TPO, SCF, and FL significantly enhanced ex vivo expansion of CD34+ cells to subsets of primitive (CD34+CD38- cells, colony-forming unit-mixed [CFU-GEMMs]), erythroid (CFU-Es), myeloid (CFU-GMs), and megakaryocytic (CD61+CD41+ cells, CFU-MKs) progenitors, as well as their multilineage engraftment in NOD/SCID mice. Interestingly, the short exposure of expanded cells to CTCE-0214 (100 and 500 ng/ml) for 4 hours did not increase the quantity of progenitor cells but enhanced their engraftment capacity. The proportion of CD34+ cells expressing surface CXCR4 was decreased, but the overall number of this population increased upon expansion. The small peptide analogue of SDF-1 could be developed for ex vivo expansion and improving engraftment of cord blood transplantation.