Kisspeptin treatment reverses high prolactin levels and improves gonadal function in hypothyroid male rats.

We evaluated whether the administration of kisspeptin-10 (Kp10) is capable of restoring gonadal function in hypothyroid male rats. Hypothyroidism was induced with 6-propyl-2-thiouracil (PTU) for three months. In the last month, half of the hypothyroid animals were treated with Kp10.

Norepinephrine modulation of heat dissipation in female rats lacking estrogen.

Postmenopausal hot flushes are caused by lack of estradiol (E2) but their neuroendocrine basis is still poorly understood. Here, we investigated the interrelationship between norepinephrine and hypothalamic neurons, with emphasis on kisspeptin neurons in the arcuate nucleus (ARC), as a regulatory pathway in the vasomotor effects of E2. Ovariectomized (OVX) rats displayed increased tail skin temperature (TST), and this increase was prevented in OVX rats treated with E2 (OVX + E2).

Prior aerobic physical training modulates neuropeptide expression and central thermoregulation after ovariectomy in the rat.

This study compared the effects of aerobic physical training and estradiol (E2) replacement on central pathways involved with thermoregulation in ovariectomized rats. Rats were assigned to untrained ovariectomized treated with placebo (UN-OVX), untrained ovariectomized treated with E2 (E2-OVX), and trained ovariectomized (TR-OVX) groups. Tail skin temperature (TST), internal temperature (Tint), and basal oxygen consumption (VO) were recorded.

Hypothalamic Expression of Estrogen Receptor Isoforms Underlies Estradiol Control of Luteinizing Hormone in Female Rats.

Luteinizing hormone (LH) secretion during the ovarian cycle is governed by fluctuations in circulating estradiol (E2) that oppositely regulate kisspeptin neurons in the anteroventral periventricular nucleus (AVPV) and arcuate nucleus (ARC) of the hypothalamus. However, how these effects are orchestrated to achieve fertility is unknown. Here, we have tested the hypothesis that AVPV and ARC neurons have different sensitivities to E2 to coordinate changes in LH secretion.

Kisspeptin Treatment Restores Ovarian Function in Rats with Hypothyroidism.

Hypothyroidism causes ovarian dysfunction and infertility in women, in addition to being associated with hyperprolactinemia and reduced hypothalamic expression of kisspeptin (Kp). However, it remains unknown whether and how Kp is able to reverse the ovarian dysfunction caused by hypothyroidism. Hypothyroidism was induced in adult female Wistar rats using 6-propyl-2-thiouracil for 3 months.

Using Graphene-Based Materials for Stiff and Strong Poly(ethylene glycol) Hydrogels.

Blood-contacting devices are increasingly important for the management of cardiovascular diseases. Poly(ethylene glycol) (PEG) hydrogels represent one of the most explored hydrogels to date. However, they are mechanically weak, which prevents their use in load-bearing biomedical applications (e.

Grafting MSI-78A onto chitosan microspheres enhances its antimicrobial activity.

MSI-78A (Pexiganan A) is one of the few antimicrobial peptides (AMPs) able to kill Helicobacter pylori, a pathogenic bacterium that colonizes the gastric mucosa of half of the world's population. Antibiotics fail in 20-40% of H. pylori-infected patients, reinforcing the need for alternative treatments.

Graphene Oxide Coating Improves the Mechanical and Biological Properties of Decellularized Umbilical Cord Arteries.

The lack of small-diameter vascular grafts (inner diameter <5 mm) to substitute autologous grafts in arterial bypass surgeries has a massive impact on the prognosis and progression of cardiovascular diseases, the leading cause of death globally. Decellularized arteries from different sources have been proposed as an alternative, but their poor mechanical performance and high collagen exposure, which promotes platelet and bacteria adhesion, limit their successful application. In this study, these limitations were surpassed for decellularized umbilical cord arteries through the coating of their lumen with graphene oxide (GO).

Graphene-based materials: the key for the successful application of pHEMA as a blood-contacting device.

Thrombosis and infection are the leading causes of blood-contacting device (BCD) failure, mainly due to the poor performance of existing biomaterials. Poly(2-hydroxyethyl methacrylate) (pHEMA) has excellent hemocompatibility but the weak mechanical properties impair its use as a bulk material for BCD. As such, pHEMA has been explored as a coating, despite the instability and difficulty of attachment to the underlying polymer compromise its success.

Erratum: Borges, I., et al. Exposure of Smaller and Oxidized Graphene on Polyurethane Surface Improves its Antimicrobial Performance. 2020, , 349.

The authors wish to make the following corrections to this paper [...

Reduced dopaminergic tone during lactation is permissive to the hypothalamic stimulus for suckling-induced prolactin release.

Dopamine from tuberoinfundibular dopaminergic (TIDA) neurones tonically inhibits prolactin (PRL) secretion. Lactational hyperprolactinaemia is associated with a reduced activity of TIDA neurones. However, it remains controversial whether the suckling-induced PRL surge is driven by an additional decrease in dopamine release or by stimulation from a PRL-releasing factor.

Orally administrated chitosan microspheres bind Helicobacter pylori and decrease gastric infection in mice.

Persistent Helicobacter pylori (H. pylori) infection is related to 90% of gastric cancers. With bacterial resistance rising and treatment inefficiency affecting 15% of the patients, alternative treatments urge.

Graphene Surfaces Interaction with Proteins, Bacteria, Mammalian Cells, and Blood Constituents: The Impact of Graphene Platelet Oxidation and Thickness.

Graphene-based materials (GBMs) have been increasingly explored for biomedical applications. However, interaction between GBMs-integrating surfaces and bacteria, mammalian cells, and blood components, that is, the major biological systems in our body, is still poorly understood. In this study, we systematically explore the features of GBMs that most strongly impact the interactions of GBMs films with plasma proteins and biological systems.

Exposure of Smaller and Oxidized Graphene on Polyurethane Surface Improves its Antimicrobial Performance.

Catheter-related infections are a common worldwide health problem, highlighting the need for antimicrobial catheters. Here, antibacterial potential of graphene nanoplatelets (GNP) incorporated in the commonly used polymer for catheter manufacture-polyurethane (PU)-is investigated. Two strategies are explored: melt-blending, producing a composite, and dip coating, where a composite layer is deposited on top of PU.

Estradiol Potentiates But Is Not Essential for Prolactin-Induced Suppression of Luteinizing Hormone Pulses in Female Rats.

Hyperprolactinemia causes infertility by suppressing gonadotropin-releasing hormone (GnRH) and luteinizing hormone (LH) secretion. Because effects of prolactin (PRL) on the hypothalamus usually require estradiol (E2), we investigated the role of E2 in PRL-induced suppression of LH pulses. Ovariectomized (OVX) rats treated with oil or E2 (OVX + E2) received a subcutaneous injection of ovine PRL (oPRL) 30 minutes before serial measurement of LH in the tail blood by enzyme-linked immunosorbent assay.

Kisspeptin Stimulation of Prolactin Secretion Requires Kiss1 Receptor but Not in Tuberoinfundibular Dopaminergic Neurons.

Kisspeptin has been shown to stimulate prolactin secretion. We investigated whether kisspeptin acts through the Kiss1 receptor (Kiss1r) to regulate dopamine and prolactin. Initially, we evaluated prolactin response in a Kiss1r-deficient mouse line, in which Kiss1r had been knocked into GnRH neurons (Kiss1r-/-R).

α-Estrogen and Progesterone Receptors Modulate Kisspeptin Effects on Prolactin: Role in Estradiol-Induced Prolactin Surge in Female Rats.

Kisspeptin (Kp) regulates prolactin (PRL) in an estradiol-dependent manner. We investigated the interaction between ovarian steroid receptors and Kp in the control of PRL secretion. Intracerebroventricular injections of Kp-10 or Kp-234 were performed in ovariectomized (OVX) rats under different hormonal treatments.

Bacteria-targeted biomaterials: Glycan-coated microspheres to bind Helicobacter pylori.

Unlabelled: Gastric cancer is the third leading cause of cancer related deaths worldwide and Helicobacter pylori (H. pylori) persistent infection has been pointed as a causative agent of this disease. Current antibiotic based treatments to eradicate this bacterium fail in 20% of the patients, potentially leaving 140 million people in the world without alternative therapy.

The potential utility of chitosan micro/nanoparticles in the treatment of gastric infection.

Gastric infections are mainly caused by Helicobacter pylori (H. pylori), a bacterium that colonizes the gastric mucosa of over 50% of the world's population. Chronic H.