The Regeneration of Large-Sized and Vascularized Adipose Tissue Using a Tailored Elastic Scaffold and dECM Hydrogels.

A dome-shaped elastic poly(l-lactide-co-caprolactone) (PLCL) scaffold with a channel and pore structure was fabricated by a combinative method of 3D printing technology and the gel pressing method (13 mm in diameter and 6.5 mm in thickness) for patient-specific regeneration. The PLCL scaffold was combined with adipose decellularized extracellular matrix (adECM) and heart decellularized extracellular matrix (hdECM) hydrogels and human adipose-derived stem cells (hADSCs) to promote adipogenesis and angiogenesis. These scaffolds had mechanical properties similar to those of native adipose tissue for improved tissue regeneration. The results of the in vitro real-time PCR showed that the dECM hydrogel mixture induces adipogenesis. In addition, the in vivo study at 12 weeks demonstrated that the tissue-engineered PLCL scaffolds containing the hydrogel mixture (hdECM/adECM (80:20)) and hADSCs promoted angiogenesis and adipose tissue formation, and suppressed apoptosis. Therefore, we expect that our constructs will be clinically applicable as material for the regeneration of patient-specific large-sized adipose tissue.

Vascularization of PLGA-based bio-artificial beds by hypoxia-preconditioned mesenchymal stem cells for subcutaneous xenogeneic islet transplantation.

BACKGROUND: Subcutaneous tissue is an attractive extra-hepatic heterotopic site for islet transplantation; however, poor oxygen tension and blood supply during early engraftment of implanted islets have limited the use of this site in clinical applications. METHODS: This study investigated the vascularization potential of hypoxia-preconditioned mesenchymal stem cells (3% O2 ; hypo-MSCs) in PLGA-based bio-artificial beds for subsequent subcutaneous islet transplantation. Sheet-typed polymeric PLGA scaffolds coated with hypo-MSCs or normo-MSCs (MSCs cultured under normoxia conditions, 21% O2 ) were implanted subcutaneously in mice. RESULTS: Compared to normo-MSCs, hypo-MSCs significantly enhanced vasculogenesis, both on the interior and exterior surfaces of the implanted PLGA devices, which peaked 4 weeks after implantation. Further, infusion of porcine islets inside the prevascularized PLGA bed restored normal glycemic control in 6 of 6 STZ-induced diabetic mice. The mass of the marginal islet was approximately 2000 IEQs, which is comparable to that required for the renal subcapsular space, a highly vascularized site. CONCLUSIONS: Therefore, PLGA-based bio-artificial devices prevascularized with hypo-MSCs could be a useful modality for successful subcutaneous islet transplantation, which is of high clinical relevance.

Urinary desmosine is associated with emphysema severity and frequent exacerbation in patients with COPD.

BACKGROUND AND OBJECTIVE: Matrix degradation is a key feature of chronic obstructive pulmonary disease (COPD). Desmosine and isodesmosine (desmosines) are excreted in urine following matrix degradation. The main purpose of this study was to investigate the association between computed tomography (CT) emphysema indices and urinary desmosines in patients with COPD. METHODS: A total of 152 subjects were selected from the Korean Obstructive Lung Disease cohort. Their urine samples were assayed for desmosines using liquid chromatography-tandem mass spectrometry (LC-MS/MS) methods. The cohort was divided into emphysema-dominant (n = 80) and non-emphysema dominant- (n = 72) groups according to the CT emphysema index. RESULTS: The level of urinary desmosines was significantly higher in the emphysema-dominant group. Significant differences were also observed between the two groups for body mass index and lung function. Multivariate analysis indicated that a high level of urinary desmosines was a significant independent predictor of emphysema (relative risk: 2.6; 95% CI: 1.11-6.09; P = 0.028). The percentage of frequent exacerbators was significantly higher in the high urinary desmosine group in the first year of follow-up (P = 0.041). The mean number of exacerbations was higher in the high urinary desmosine group, although this difference was not statistically significant (P = 0.067). The changes in emphysema index did not differ between the two urinary desmosine groups over 3 years of follow-up. CONCLUSION: This study indicates that the level of urinary desmosines measured by LC-MS/MS methods is associated with the CT emphysema index. Urinary desmosine can be a useful predictor in identifying frequent exacerbators.

Use of a Turn Coil and Channel Above a GMR-SV Device to Observe and Measure the Properties of Deoxidized Red Blood Cells Coupled to Magnetic Beads.

A giant magnetoresistance-spin valve (GMR-SV) having highly sensitive magnetic properties was prepared with a multilayer soft ferromagnetic/non-magnetic/pinned ferromagnetic/anti-ferromagnetic iridium manganese (IrMn) top layer (NiFe/CoFe/Cu/CoFe/IrMn) structure. Micron-sized magnetic beads (MBs) with a diameter of 1 µm immersed in a solution containing 50 mg of Co-Si-OH/ml were attached to red blood cells (RBCs) having the very low magnetization of hemoglobin (HEM) to detect a deoxidized RBC combined with MBs (RBC+MBs). The RBC+MB combinations can be captured on a single-turn µ-coil that maintains a magnetic field large enough to detect the MBs attached to the RBC. When the RBC+MBs passes through a PR µ-channel with a width of 10 µm, its stopping and starting are controlled by the electrical AC input signal applied to the single-turn µ-coil. The RBC+MBs combinations captured above the µ-device of the GMR-SV change the output signal and thus, can be used for detection. This observation implies that this device can be used as a biosensor to analyze the coupling force between the HEM and the MBs for RBCs with deformed membranes passing through a narrow capillary.

Characteristics and Clinical Significance of De Novo Donor-Specific Anti-HLA Antibodies after Kidney Transplantation.

BACKGROUND: The association of de novo donor-specific anti-human leukocyte antigens (HLA) antibodies (DSA) and development of antibody-mediated rejection (AMR) in kidney transplant recipients (KTRs) is still undetermined. METHODS: We prospectively screened de novo DSA in 167 KTRs during 32 months after kidney transplantation (KT). Timing of DSA detection was at 3, 6, and 12 months post-transplant and annually thereafter and when clinically indicated. DSA levels were determined by Luminex assays and expressed as mean fluorescence intensity (MFI). We evaluated the incidence, characteristics of DSA, and association between DSA and tacrolimus trough levels or AMR. RESULTS: De novo DSA developed in 16 KTRs (9.6%) and acute AMR occurred more commonly in KTRs with de novo DSA compared to KTRs without de novo DSA (18.8% vs. 0%, P < 0.001). All de novo DSA were against class II antigens. The mean number of DSA was 1.8 ± 1.2 and the average MFI of DSA was 7,399 ± 5,470. Tacrolimus trough level during the first 0-2 months after KT was an independent predictor of DSA development (hazard ratio, 0.70; 95% confidence interval, 0.50-0.99; P = 0.043). No differences were found in the number of DSA, average MFI of DSA, and tacrolimus levels during the first year between de novo DSA-positive KTRs with AMR and those without AMR. CONCLUSION: The results of our study suggest that monitoring of DSA and maintaining proper tacrolimus levels are essential to prevent AMR during the initial period after KT.

Quantitative structural characterization of phosphatidylinositol phosphates from biological samples.

The aspects of cellular metabolism controlled by phosphatidylinositol phosphates (PtdInsPs) have been broadly expanded, and these phospholipids have drawn tremendous attention as pleiotropic signaling molecules. PtdInsPs analysis using LC/MS/MS has remained challenging due to the strong hydrophilicity of these lipids. Multiple reaction monitoring (MRM) or a neutral loss scan has been performed to quantitatively measure PtdInsPs after chemical derivatization on the phosphate groups of inositol moieties. Only predefined PtdInsPs can be measured in MRM mode, and fatty acyl compositions of sn-1 and sn-2 positions of PtdInsPs cannot be obtained from a neutral loss scan. In our present study, we developed a simple LC/MS/MS method for structural identification of sn-1 and sn-2 fatty acids of PtdInsPs and their relative quantitation. Precursor ion scans of sn-1 monoacylglycerols (MAGs) of PtdInsPs provided structural information about the lipids, and ammonium adduction enhanced signal intensities of PtdInsPs. The relative amount of observed PtdInsPs in biological samples could be compared using chromatographic peak areas from the neutral loss scans. Using precursor ion scans of sn-1 MAG and neutral loss scans of headgroups, major PtdInsPs in cells and tissues were successfully identified with structural information of sn-1 and sn-2 fatty acids, and their relative amounts in different samples were compared.

Dyadic Effects of Individual and Friend on Physical Activity in College Students.

OBJECTIVE: Physical activity (PA) tends to decline throughout the college years, and close friends' influence is known to be an important factor in maintaining PA. This study examined the actor effect and partner effect between an individual and his/her friend regarding the influence of self-efficacy and social support on PA among Korean college students. DESIGN AND SAMPLE: Cross-sectional survey data from 108 pairs of individual students and friends were analyzed. MEASURES: The survey questionnaire measured PA, self-efficacy toward exercise, social support for PA, anxiety and depression, community environments, and perceived health status. Structural equation modeling with path analysis was conducted to test Actor-Partner Interdependence Model (APIM) explaining close relationships on PA. RESULTS: One-sided partner effect that friends' perceived friend support was directly related to individual's PA (ß = 0.20, p < .05) was revealed. Regarding actor effects, self-efficacy was directly related to higher levels of PA for individual and friend. Perceived health status was related to higher level of individuals' PA. CONCLUSIONS: These results suggest a role for public health nurses in developing interventions for college-aged young adults that promotes friend support for PA as well as individual self-efficacy toward PA, to engage young adults in establishing lifelong health-promoting PA.

Effect of scaffold microarchitecture on osteogenic differentiation of human mesenchymal stem cells.

Design of macroporous synthetic grafts that can promote infiltration of cells, their differentiation, and synthesis of bone-specific extracellular matrix is a key determinant for in vivo bone tissue regeneration and repair. In this study, we investigated the effect of the microarchitecture of the scaffold on osteogenic differentiation of human mesenchymal stem cells (hMSCs). Poly(ethylene glycol) diacrylate-co-N-acryloyl 6-aminocaproic acid cryogels were fabricated to have either a pore network consisting of cellular, randomly oriented pores (termed 'spongy') or a pore network consisting of lamellar columns (termed 'columnar'), with both cryogel types showing a similar porosity. Both spongy and columnar cryogels supported comparable levels of cell viability and proliferation of hMSCs in vitro. However, spongy cryogels promoted osteogenic differentiation to a greater extent than their columnar counterparts, as evidenced by increased alkaline phosphatase activity and osteoblastic gene expression over 21 days post culture. Leveraging upon our previous work, we further evaluated the ability of these synthetic scaffolds in conjunction with mineralisation to promote ectopic bone formation upon subcutaneous implantation in nude rats. Mineralised spongy and columnar cryogels, both in the presence and absence of exogenous hMSCs, promoted ectopic bone formation in vivo. No such bone formation was observed in acellular cryogels devoid of mineralisation, with extensive host cell infiltration and vascularisation in columnar cryogels, and negligible infiltration into spongy cryogels. Our results thus present a novel method to tune the microarchitecture of porous polymeric scaffolds, in addition to suggesting their efficacy as synthetic bone grafts.

Effects of an Orff Music Activity Intervention Program on the Ego-Resilience, Peer Relationships, Happiness, Interpersonal Care Awareness, Anxiety, and Stress of Children from Multicultural Families in Republic of Korea.

This study developed an interpersonal care-based Orff music activity program for children from multicultural families in Republic of Korea. We measured its effects on ego-resilience, peer relationships, happiness, interpersonal care awareness, anxiety, and stress. The participants were 74 children from third to sixth grade attending 10 regional children's centers in Cheonan-si, Chungcheongnam-do Province, Republic of Korea. They were randomly assigned to 36 experimental groups and 38 control groups. The experimental program was developed based on investigations of human care theory, expressions of care, and Orff music activities. The experiment was conducted twice a week for five weeks in 45 min sessions. Data were collected from June to September 2020. We used questionnaires on ego-resilience, peer relationships, happiness, and interpersonal care awareness to measure the effects, which were analyzed through frequency and descriptive statistics. Anxiety, physiological anxiety, acculturation stress, and physiological stress were measured using Behavior Detection VibraImage System Version 8.1 PRO (VIBRASYSTEM Ltd., Co., Seoul, Republic of Korea). The homogeneity of the variables across groups was examined using the χ² test, t-test, and Fisher's exact test. The effects were examined using repeated measures variance analysis and independent t-tests. The results showed that the program had significant effects on ego-resilience, peer relationships, happiness, interpersonal care awareness, physiological anxiety, and physiological stress. The findings suggest that interpersonal care nursing can be effective for children from multicultural families, and the program can be used for intervention to improve children's mental health.

Development of polycaprolactone grafts with improved physical properties and body stability using a screw extrusion-type 3D bioprinter.

Three-dimensional (3D) bioprinter including screw extruder was developed, and the polycaprolactone (PCL) grafts fabricated by screw-type and pneumatic pressure-type bioprinters were comparatively evaluated. The density and tensile strength of the single layers printed by the screw-type were 14.07% and 34.76% higher, respectively, than those of the single layers produced by the pneumatic pressure-type. The adhesive force, tensile strength, and bending strength of the PCL grafts printed by the screw-type bioprinter were 2.72 times, 29.89%, and 67.76% higher, respectively, than those of the PCL grafts prepared by the pneumatic pressure-type bioprinter. By evaluating the consistency with the original image of the PCL grafts, we found that it had a value of about 98.35%. The layer width of the printing structure was 485.2 ± 0.004919 µm, which was 99.5% to 101.8% compared to the set value (500 µm), indicating high accuracy and uniformity. The printed graft had no cytotoxicity, and there were no impurities in the extract test. In the in vivo studies, the tensile strength of the sample 12 months after implantation was reduced by 50.37% and 85.43% compared to the initial point of the sample printed by the screw-type and the pneumatic pressure-type, respectively. Through observing the fractures of the samples at 9- and 12-month samples, we found that the PCL grafts prepared by the screw-type had better in vivo stability. Therefore, the printing system developed in this study can be used as a treatment for regenerative medicine.

Acute progesterone feedback on gonadotropin secretion is not demonstrably altered in estradiol-pretreated women with polycystic ovary syndrome.

Women with polycystic ovary syndrome (PCOS) demonstrate gonadotropin-releasing hormone (GnRH) pulse generator resistance to suppression with 7 days of progesterone and estradiol administration. It remains unknown whether such women demonstrate impairments in acute progesterone negative feedback on LH pulse frequency or progesterone positive feedback on gonadotropin release. This was a randomized, double-blind, placebo-controlled crossover study designed to test the hypothesis that acute, progesterone-related suppression of LH pulse frequency and progesterone-related augmentation of gonadotropin release are impaired in PCOS. Twelve normally cycling women and 12 women with PCOS completed study. Volunteers were pretreated with transdermal estradiol (0.2 mg/day) for 3 days and then underwent a frequent blood sampling study (20:00-20:00 h), during which they received micronized progesterone (100 mg) or placebo at 06:00 h. In a second study admission, volunteers received the intervention they did not receive during the first admission, but the protocol was otherwise identical. The primary outcome measures were LH secretory characteristics and circulating gonadotropin concentrations. Exogenous progesterone did not reduce LH pulse frequency in either group. Mean LH, pulsatile LH secretion, LH pulse mass, and mean FSH increased more with progesterone compared to placebo in both groups. Although trends toward less pronounced changes in LH pulse mass and pulsatile LH secretion were observed in the PCOS group, these differences were not statistically significant. In summary, exogenous progesterone did not suppress LH pulse frequency within 12 hours in estradiol-pretreated women, and the positive feedback effect of progesterone on gonadotropin release was not demonstrably impaired in PCOS. NEW & NOTEWORTHY: This study indicated that exogenous progesterone does not reduce LH pulse frequency within 12 h in women with PCOS, but progesterone acutely increased gonadotropin in these women. This study suggested that progesterone-related augmentation of gonadotropin release may be impaired in PCOS compared to normally cycling women, but this finding was not statistically significant.

Novel Chitosan Dermal Filler with Enhanced Moldability and Elasticity.

Currently, dermal fillers are largely based on commercialized cross-linked hyaluronic acid (HA) injections, which require a large injection force. Additionally, HA can be easily decomposed by enzymes, and HA-treated tissues present a risk of developing granuloma. In this study, a chitosan-based dermal filler is presented that operates on a liquid-to-gel transition and allows the injection force to be kept ≈4.7 times lower than that required for HA injections. Evaluation of the physical properties of the chitosan filler indicates high viscoelasticity and recovery rate after gelation at 37 °C. Furthermore, in an in vivo evaluation, the liquid injection-type chitosan filler transitions to a gel state within 5 min after injection into the body, and exhibits a compressive strength that is ≈2.4 times higher than that of cross-linked HA. The filler also exhibits higher moldability and maintains a constant volume in the skin for a longer time than the commercial HA filler. Therefore, it is expected that the chitosan filler will be clinically applicable as a novel material for dermal tissue restoration and supplementation.

Self-assembling peptide gels promote angiogenesis and functional recovery after spinal cord injury in rats.

Spinal cord injury (SCI) leads to disruption of the blood-spinal cord barrier, hemorrhage, and tissue edema, which impair blood circulation and induce ischemia. Angiogenesis after SCI is an important step in the repair of damaged tissues, and the extent of angiogenesis strongly correlates with the neural regeneration. Various biomaterials have been developed to promote angiogenesis signaling pathways, and angiogenic self-assembling peptides are useful for producing diverse supramolecular structures with tunable functionality. RADA16 (Ac-RARADADARARADADA-NH2), which forms nanofiber networks under physiological conditions, is a self-assembling peptide that can provide mechanical support for tissue regeneration and reportedly has diverse roles in wound healing. In this study, we applied an injectable form of RADA16 with or without the neuropeptide substance P to the contused spinal cords of rats and examined angiogenesis within the damaged spinal cord and subsequent functional improvement. Histological and immunohistochemical analyses revealed that the inflammatory cell population in the lesion cavity was decreased, the vessel number and density around the damaged spinal cord were increased, and the levels of neurofilaments within the lesion cavity were increased in SCI rats that received RADA16 and RADA16 with substance P (rats in the RADA16/SP group). Moreover, real-time PCR analysis of damaged spinal cord tissues showed that IL-10 expression was increased and that locomotor function (as assessed by the Basso, Beattie, and Bresnahan (BBB) scale and the horizontal ladder test) was significantly improved in the RADA16/SP group compared to the control group. Our findings indicate that RADA16 modified with substance P effectively stimulates angiogenesis within the damaged spinal cord and is a candidate agent for promoting functional recovery post-SCI.

Detection of Lysyl Oxidase Activity in Tumor Extracellular Matrix Using Peptide-Functionalized Gold Nanoprobes.

High LOX levels in the tumor microenvironment causes the cross-linking of extracellular matrix components and increases the stiffness of tumor tissue. Thus, LOX plays an important role in tumorigenesis and in lowering the tumor response to anticancer drugs. Despite comprehensive efforts to identify the roles of LOX in the tumor microenvironment, sensitive and accurate detection methods have not yet been established. Here, we suggest the use of gold nanoparticles functionalized with LOX-sensitive peptides (LS-AuNPs) that aggregate upon exposure to LOX, resulting in a visual color change. LOX-sensitive peptides (LS-peptides) contain lysine residues that are converted to allysine in the presence of LOX, which is highly reactive and binds to adjacent allysine, resulting in the aggregation of the AuNPs. We demonstrated that the synthesized LS-AuNPs are capable of detecting LOX sensitively, specifically both in vitro and in the tissue extract. Moreover, the suggested LS-AuNP-based assay is more sensitive than commonly employed assays or commercially available kits. Therefore, the LS-AuNPs developed in this study can be used to detect LOX levels and can be further used to predict the stiffness or the anticancer drug resistance of the tumor.

Enhancement of the immune responses of mice to Bacillus anthracis protective antigen by CIA07 combined with alum.

Anthrax is an acute zoonotic disease caused by infection with Bacillus anthracis. B. anthracis spores are highly resistant to environmental degradation and are used as a biological weapon. In this study, we investigated the adjuvant activity of CIA07 to anthrax protective antigen (PA). A/J mice were immunized intraperitoneally once, or twice with a 4-week interval, with recombinant PA alone or combined with alum, CpG1826, or CIA07 as adjuvant, and serum anti-PA IgG antibody responses were measured 4 weeks after each immunization. All three adjuvants significantly enhanced anti-PA IgG antibody titer 4 weeks after the priming and boosting immunizations, and alum gave the highest titer. In order to evaluate the adjuvant activity of CIA07 in the presence of alum, Balb/c mice were immunized 3 times at 1-week intervals with PA in combination with alum, CIA07 or alum plus CIA07, and the immune responses were assessed 2 weeks after the third immunization. The serum anti-PA IgG antibody titer of the CIA07-treated group was 14-fold higher than the group given PA alone, and the coadministration of CIA07 with alum further increased the titer 3.5-fold (P < 0.05). The toxin neutralizing activity of the sera from the mice given the combination of CIA07 and alum was 109-times higher than the animals given PA alone. The mice given CIA07 plus alum also showed a marked increase in the number of IFN-gamma-, IL-2-, and IL-4-producing CD4(+) T cells among their splenocytes. These data suggest the potential of CIA07 in combination with alum as an adjuvant for the development of a potent anthrax vaccine.

Skin Regeneration with a Scaffold of Predefined Shape and Bioactive Peptide Hydrogels.

We developed a highly elastic customized scaffold for soft tissue regeneration and combined them with bioactive hydrogels with stem cell-inducing ability. This was done to mimic mechanical properties of native soft tissues and improve the viability of transplanted cells as well as efficiency of tissue regeneration. The proposed study was aimed at evaluating various characteristics of scaffolds and investigating their tissue-regenerating ability. Finger-shaped porous scaffolds were successfully fabricated by an indirect 3D printing of poly (L-lactide-co-ɛ-caprolactone) (PLCL), which provides high elasticity for soft tissue engineering. In addition, a self-assembling peptide hydrogel coupled with substance P (RARADADARARADADA/RARADADARARADADA-substance P, RADA16/RADA16-SP) was used to accelerate angiogenesis and recruit intrinsic mesenchymal stem cells (MSCs). This study included three kinds of groups: Group I = PLCL scaffold with human dermal fibroblasts (HDFs) (P+C), Group II = PLCL scaffold with HDFs and RADA16 (P+C+R), and Group III = PLCL scaffold with HDFs, RADA16, and RADA16-SP (P+C+R+S). The samples were implanted into immunodeficient mice subcutaneously and harvested at 1 and 4 weeks. Tissue regeneration was evaluated by histological analysis with hematoxylin and eosin (H&E) and Masson's trichrome (MT) staining. The images showed that a large number of cells were recruited into the scaffolds, and collagen was deposited in the constructs of the P+C+R+S group. Additionally, recruitment of MSCs, angiogenesis, and collagen were observed by immunofluorescence staining. The results show that the P+C+R+S group had more type I and type III collagen, which are formed in soft tissues, and were deposited on the scaffold compared with the other groups. Moreover, more blood vessels and MSCs were induced in the P+C+R+S group than in those of the P + C and P+C+R groups. Consequently, the results suggest that the construct of the customized porous PLCL scaffold and RADA16/RADA16-SP hydrogel could be a good treatment modality to treat skin defects.

Progesterone administration does not acutely alter LH pulse secretion in the mid-follicular phase in women.

It remains unclear how rapidly progesterone suppresses luteinizing hormone (LH) pulse frequency in women. Previous studies suggested that progesterone markedly increases LH pulse amplitude but does not slow LH pulse frequency within 10 h in estradiol-pretreated women studied during the late follicular phase. However, this experimental paradigm may be a model of preovulatory physiology, and progesterone may have different effects at other times of the cycle. We studied regularly cycling, nonobese women without hyperandrogenism to assess the acute effect of progesterone during the midfollicular phase and in the absence of estradiol pretreatment. The study involved two admissions in separate cycles (cycle days 5-9). For each admission, either oral micronized progesterone (100 mg) or placebo was administered at 0900 h in a randomized, double-blind fashion. Frequent blood sampling was performed between 0900 and 1900 h to define 10-h LH pulsatility. Treatment crossover (placebo exchanged for progesterone and vice versa) occurred in a subsequent cycle. After an interim futility analysis, the study was halted after 7 women completed study. Mean progesterone concentrations after placebo and progesterone administration were 0.5 ± 0.1 (mean ± SD) and 6.7 ± 1.6 ng/mL, respectively. Compared to placebo, progesterone was not associated with a significant difference in 10-h LH pulse frequency (0.79 ± 0.35 vs. 0.77 ± 0.28 pulses/h, P = 1.0) or amplitude (3.6 ± 2.8 vs. 4.3 ± 2.8 IU/L, P = 0.30). This study suggests that LH pulse frequency is not rapidly influenced by progesterone administration during the midfollicular phase.

Progesterone Suppression of Luteinizing Hormone Pulse Frequency in Adolescent Girls With Hyperandrogenism: Effects of Metformin.

Context: Polycystic ovary syndrome (PCOS) and adolescent hyperandrogenism (HA) are characterized by rapid luteinizing hormone (LH) pulse frequency. This partly reflects impaired gonadotropin-releasing hormone pulse generator (hypothalamic) sensitivity to progesterone (P4) negative feedback. We assessed whether metformin may improve P4 sensitivity in adolescent HA, for which it is prescribed widely. Objective: To test the hypothesis that metformin improves hypothalamic P4 sensitivity in adolescent HA. Design: Nonrandomized, interventional trial. Setting: Academic clinical research unit. Participants: Ten adolescent girls with HA. Intervention: The girls underwent LH sampling every 10 minutes for 11 hours, at study baseline and after 7 days of oral P4 and estradiol (E2). Participants then took metformin (1 g twice daily) for 9.4 to 13.7 weeks, after which participants again underwent frequent LH sampling before and after 7 days of oral P4 and E2 (while continuing metformin). Total and free testosterone (T) and fasting insulin were assessed at each admission. At admissions 1 and 3, 2-hour oral glucose tolerance tests were performed. Main Outcome Measure: Metformin-related change in hypothalamic P4 sensitivity index [percent change in LH pulse frequency (before vs after P4 and E2) divided by day 7 P4 level]. Results: Free T levels decreased by 29% with metformin (P = 0.0137). Measures of hyperinsulinemia and P4 sensitivity index did not significantly change with metformin use. Conclusion: Short-term metformin use improved biochemical hyperandrogenemia, but did not improve hypothalamic sensitivity to P4 suppression, in adolescent girls.

Progesterone-Mediated Inhibition of the GnRH Pulse Generator: Differential Sensitivity as a Function of Sleep Status.

Context: During normal, early puberty, luteinizing hormone (LH) pulse frequency is low while awake but increases during sleep. Mechanisms underlying such changes are unclear, but a small study in early pubertal girls suggested that differential wake-sleep sensitivity to progesterone negative feedback plays a role. Objective: To test the hypothesis that progesterone acutely reduces waking LH pulse frequency more than sleep-associated pulse frequency in late pubertal girls. Design: Randomized, placebo-controlled, double-blinded crossover study. Setting: Academic clinical research unit. Participants: Eleven normal, postmenarcheal girls, ages 12 to 15 years. Intervention: Subjects completed two 18-hour admissions in separate menstrual cycles (cycle days 6 to 11). Frequent blood sampling for LH assessment was performed at 1800 to 1200 hours; sleep was encouraged at 2300 to 0700 hours. Either oral micronized progesterone (0.8 mg/kg/dose) or placebo was given at 0700, 1500, 2300, and 0700 hours, before and during the first admission. A second admission, performed at least 2 months later, was identical to the first except that placebo was exchanged for progesterone or vice versa (treatment crossover). Main Outcome Measures: LH pulse frequency during waking and sleeping hours. Results: Progesterone reduced waking LH pulse frequency by 26% (P = 0.019), with no change observed during sleep (P = 0.314). The interaction between treatment condition (progesterone vs placebo) and sleep status (wake vs sleep) was highly significant (P = 0.007). Conclusions: In late pubertal girls, progesterone acutely reduced waking LH pulse frequency more than sleep-associated pulse frequency. Differential wake-sleep sensitivity to progesterone negative feedback may direct sleep-wake LH pulse frequency changes across puberty.