Obesity, gestational diabetes and macrosomia are associated with increasing rates of early-term induction of labour at The Canberra Hospital.

BACKGROUND: Early-term delivery is an important cause of short-term neonatal morbidity and associated high healthcare costs, with possible additional long-term developmental ramifications. As a form of 'iatrogenic' delivery, induction of labour (IOL) is a potentially modifiable contributor to this burden. AIMS: To determine patterns of, and primary indication for, early-term IOL, as well as temporal trends in this primary indication and differences from other modes of delivery with respect to maternal factors and maternal/neonatal outcomes. MATERIALS AND METHODS: The Canberra Hospital births database (2012-2016) was queried; patients who underwent IOL were included in the analysis. RESULTS: Total deliveries and the proportion of early-term IOL procedures rose markedly over the time period. Gestational diabetes mellitus (GDM) was the most frequent and an increasing main indication for IOL. GDM was associated with significantly higher body mass index, an increased proportion of obesity, and a greater incidence of labour complications related to macrosomia. Birthweight of neonates of diabetic mothers was significantly higher, which was associated with decreased rates of admission to the special care nursery/neonatal intensive care unit (SCN/NICU) compared to all other babies. GDM increased relative risk of early-term IOL in obese women by 1.8 times. CONCLUSIONS: The burden of GDM and early-term IOL have increased at The Canberra Hospital although adverse short-term neonatal outcomes have not, possibly suggesting appropriate management of these patients. Nonetheless, effort should be made to identify patients who can safely continue pregnancy to full term, given the higher proportion of SCN/NICU admissions among early-term neonates.

Abnormal extracellular matrix remodelling in the cervix of pregnant relaxin-deficient mice is not associated with reduced matrix metalloproteinase expression or activity.

Relaxin regulates cervical extracellular matrix (ECM) remodelling during pregnancy by modifying collagen and other ECM molecules by unknown mechanisms. We hypothesised that abnormal collagen remodelling in the cervix of pregnant relaxin-deficient (Rln1-/-) mice is due to excessive collagen (Col1a1 and Col3a1) and decreased matrix metalloproteinases (Mmp2, Mmp9, Mmp13 and Mmp7) and oestrogen receptors (Esr1 and Esr2). Quantitative polymerase chain reaction, gelatinase zymography, MMP activity assays and histological staining evaluated changes in ECM in pregnant wildtype (Rln1+/+) and Rln1-/- mice. Cervical Col1a1, Col3a1 and total collagen increased in Rln1-/- mice and were higher at term compared with Rln1+/+ mice. This was not correlated with a decrease in gelatinase (Mmp2, Mmp9) expression or activity, Mmp7 or Mmp13 expression, which were all significantly higher in Rln1-/- mice. In late pregnancy, circulating MMP2 and MMP9 were unchanged. Esr1 expression was highest in Rln1+/+ and Rln1-/- mice in late pregnancy, coinciding with a decrease in Esr2 in Rln1+/+ but not Rln1-/- mice. The relaxin receptor (Rxfp1) decreased slightly in late-pregnant Rln1+/+ mice, but was significantly higher in Rln1-/- mice. In summary, relaxin deficiency results in increased cervical collagen in late pregnancy, which is not explained by a reduction in Mmp expression or activity or decreased Rxfp1. However, an imbalance between Esr1 and Esr2 may be involved.

A Topical Hydrogel with Deferiprone and Gallium-Protoporphyrin Targets Bacterial Iron Metabolism and Has Antibiofilm Activity.

Many infectious diseases are associated with multidrug-resistant (MDR) bacteria residing in biofilms that require high antibiotic concentrations. While oral drug delivery is frequently ineffective, topical treatments have the potential to deliver higher drug concentrations to the infection site while reducing systemic side effects. This study determined the antibiofilm activity of a surgical wound gel loaded with the iron chelator deferiprone (Def) and the heme analogue gallium-protoporphyrin (GaPP), alone and in combination with ciprofloxacin. Activity against MDR Staphylococcus aureus, Staphylococcus epidermidis, Pseudomonas aeruginosa, and Acinetobacter johnsonii biofilms was assessed in the colony biofilm and artificial wound model by enumeration of CFU and correlative light/electron microscopy. While Staphylococcus biofilms were equally susceptible to GaPP and Def-GaPP gels (log10 reduction of 3.8 and 3.7, respectively), the Def-GaPP combination was crucial for significant activity against P. aeruginosa biofilms (log10 reduction of 1.3 for GaPP and 3.3 for Def-GaPP). When Def-GaPP gel was combined with ciprofloxacin, the efficacy exceeded the activity of the individual compounds. Def-GaPP delivered in a surgical wound gel showed significant antibiofilm activity against different MDR strains and could enhance the gel's wound-healing properties. Moreover, Def-GaPP indicated a potentiation of ciprofloxacin. This antibiofilm strategy has potential for clinical utilization as a therapy for topical biofilm-related infections.

Seminal Plasma Promotes Lesion Development in a Xenograft Model of Endometriosis.

The factors that predispose one-tenth of reproductive-aged women to endometriosis are poorly understood. We determined that genetic deficiency in transforming growth factor ß1 impairs endometriosis-like lesion growth in mice. Given that seminal plasma is an abundant source of transforming growth factor ß, we evaluated the effect of exposure to seminal plasma on the growth of endometrial lesions. Human endometrial explants were exposed to seminal plasma or to control medium before transfer to Prkdc(scid)-mutant (severe combined immunodeficient) mice. Xenografts exposed to seminal plasma showed an eightfold increase in volume and a 4.3-fold increase in weight after 14 days. These increases were associated with increased proliferation of endometrial epithelial cells and enhanced survival and proliferation of human stromal cells compared with those in control lesions, in which human stromal cell persistence was negligible. Although the distribution of macrophages was altered, their number and activation status did not change in response to seminal plasma. Seminal plasma stimulated the production of a variety of cytokines in endometrial tissue, including growth-regulated oncogene, granulocyte macrophage colony-stimulating factor, and IL-1ß. These data suggest that seminal plasma enhances the formation of endometriosis-like lesion via a direct effect on endometrial cell survival and proliferation, rather than via macrophage-mediated mechanisms. These findings raise the possibility that endometrial exposure to seminal plasma could contribute to endometriotic disease progression in women.

Relaxin increases human endothelial progenitor cell NO and migration and vasculogenesis in mice.

The ovarian peptide hormone, relaxin, circulates during pregnancy, contributing to profound maternal vasodilation through endothelial and nitric oxide (NO)-dependent mechanisms. Circulating numbers of bone marrow-derived endothelial cells (BMDECs), which facilitate angiogenesis and contribute to repair of vascular endothelium, increase during pregnancy. Thus, we hypothesized that relaxin enhances BMDEC NO production, circulating numbers, and function. Recombinant human relaxin-2 (rhRLX) stimulated PI3K/Akt B-dependent NO production in human BMDECs within minutes, and activated BMDEC migration that was inhibited by L-N(G)-nitroarginine methyl ester. In BMDECs isolated from relaxin/insulin-like family peptide receptor 2 gene (Rxfp2) knockout and wild-type mice, but not Rxfp1 knockout mice, rhRLX rapidly increased NO production. Similarly, rhRLX increased circulating BMDEC number in Rxfp2 knockout and wild-type mice, but not Rxfp1 knockout mice as assessed by colony formation and flow cytometry. Taken together, these results indicate that relaxin effects BMDEC function through the RXFP1 receptor. Finally, both vascularization and incorporation of GFP-labeled BMDECs were stimulated in rhRLX-impregnated Matrigel pellets implanted in mice. To conclude, relaxin is a novel regulator of BMDECs number and function, which has implications for angiogenesis and vascular remodeling in pregnancy, as well as therapeutic potential in vascular disease.

Hepatic resection for metastatic melanoma in the era of targeted therapy: A case report.

INTRODUCTION: While prognosis in metastatic melanoma has traditionally been poor, novel systemic therapies such as immunotherapy and targeted agents have improved overall survival (Steininger et al., 2021). These medications are generally well tolerated but can be associated with immune related adverse events (Remash et al., 2021). Hepatic metastatectomy is an important component of management, conferring a survival benefit over systemic therapy alone in appropriately selected patients (Medina et al., 2020). Gadoxetic acid-enhanced magnetic resonance imaging (GA-MRI) has been demonstrated to have enhanced diagnostic accuracy compared with other imaging modalities for hepatic metastases (Freitas et al., 2021). The risk of tumour seeding associated fine-needle aspiration biopsy (FNAB) of hepatic lesions varies, with most studies reporting a low incidence (Maturen et al., 2006). PRESENTATION OF CASE: In February 2020, a 75-year-old male underwent wide local excision and sentinel lymph node biopsy for stage IIA (T2B, N0, M0) melanoma. Routine surveillance without adjuvant systemic treatment was commenced. In July 2022, he presented with haemoptysis and was subsequently diagnosed with widespread metastatic disease on positive emission tomography (PET). After combination ipilimumab and nivolumab, PET scans in August 2023 revealed new liver lesions with disease response at all other metastatic sites. Following a multi-disciplinary team (MDT) discussion, the patient proceeded to hepatic metastatectomy. Histopathology demonstrated chronic necrotising granulomatous hepatitis. DISCUSSION: This case reflects the challenges involved in investigation and management of hepatic metastases in melanoma. CONCLUSION: Despite the accuracy of modern imaging, this case demonstrates the need for MDT consideration of liver biopsy in patients on anti-CTL4 treatment or with response to systemic treatment at extrahepatic sites.

Cutaneous leukocytoclastic vasculitis associated with verapamil and atorvastatin: A case report.

We report a case of biopsy-proven cutaneous leukocytoclastic vasculitis developing 10 days after starting verapamil and atorvastatin in a patient with long-standing Sjogren's syndrome. This highlights the need to monitor for this rare adverse effect.

Dissecting a diagnostic enigma: Hypertension in a young patient from an organ of Zuckerkandl paraganglioma.

Hypertension in young patients can mask rare conditions like paragangliomas, especially in the absence of conventional symptoms. A comprehensive diagnostic evaluation and multidisciplinary approach are crucial for optimal management and outcomes.

Normal prostate morphology in relaxin-mutant mice.

The peptide hormone relaxin is expressed in the prostate gland and secreted into the seminal plasma; however, its function within the prostate has not been established. Relaxin-mutant mice (Rln(-/-)) were reported to have abnormal prostate morphology, but there was no prostate phenotype in relaxin receptor-mutant (Rxfp1(-/-)) mice. The present study aimed to verify the phenotypes in the anterior, dorsal and lateral lobes of the prostate gland of Rln(-/-) and Rxfp1(-/-) mice at different adult ages. Rln(-/-) mice were also treated with relaxin to evaluate the effects of exogenously administered hormone on prostate morphology. Comparisons between these three lobes of the prostate demonstrated no obvious differences in duct morphology, epithelial height or collagen density between Rln(+/+) and Rln(-/-) mice at 2, 4, 6, 8 and 12 months of age. This was similar in Rxfp1(-/-) mice. Relaxin treatment did not affect morphology or epithelial cell height in the different lobes. Furthermore, prostate lobe morphology in transgenic mice overexpressing relaxin Tg(Rln) was not different from the wild-type controls. Rxfp1 was detected in the prostate throughout adult life, but there was no consistent expression of relaxin. In summary, the present study found no evidence to support a prostate phenotype in adult Rln- or Rxfp1-mutant mice.

Matrix metalloproteinase-2 activity, protein, mRNA, and tissue inhibitors in small arteries from pregnant and relaxin-treated nonpregnant rats.

Vascular gelatinase activity is essential for pregnancy- and relaxin (Rlx)-induced renal vasodilation and hyperfiltration in rats. The objective of this study was to further elucidate the mechanisms for the increase in vascular matrix metalloproteinase (MMP)-2 activity caused by pregnancy and Rlx. We first corroborated our earlier work by showing that pro- and active forms of MMP-2 were increased in small renal arteries from pregnant compared with virgin rats and Rlx-treated compared with vehicle-treated nonpregnant rats. We next investigated other artery types and showed that MMP-2 activity was upregulated in mesenteric arteries from pregnant rats (pro-MMP-2 by 50% and active MMP-2 by 40%, both P<0.05) and from Rlx-treated nonpregnant rats (pro-MMP-2 by 50% and active MMP-2 by 90%, both P<0.005) compared with their respective controls. To corroborate these results obtained by gelatin zymography, pro-MMP-2 protein was determined by Western analysis in the same small arteries. Pro-MMP-2 protein was increased in small renal arteries from pregnant compared with virgin rats and from Rlx- compared with vehicle-treated nonpregnant rats: pro-MMP-2-to-beta-actin ratio=0.29 vs. 0.21 (P<0.01) and 0.43 vs. 0.32 (P<0.005). Findings were similar for mesenteric arteries. MMP-2 mRNA as measured by real-time PCR was increased in small renal arteries from pregnant and Rlx-treated nonpregnant rats compared with their respective controls. There were no significant differences in tissue inhibitor of metalloproteinase (TIMP-1 or TIMP-2) activity by reverse zymography in small renal arteries. Thus increases in MMP-2 mRNA and protein expression are major factors contributing to increased MMP-2 activity in small arteries from pregnant and Rlx-treated nonpregnant rats.

Relaxin and the extracellular matrix: molecular mechanisms of action and implications for cardiovascular disease.

Myocardial fibrosis is a common endpoint in a variety of cardiac pathologies. It results from excessive accumulation of collagen and other materials that together comprise the extracellular matrix (ECM). In the past decade, the peptide hormone relaxin has emerged as an important regulator of the ECM within several organs, including the heart, and has been suggested as a novel therapeutic agent for the treatment of fibrotic disorders. This review summarises research on the anti-fibrotic actions of relaxin, outlines the potential mechanisms by which relaxin regulates the ECM in cardiovascular tissues and examines the implications of this research for the management of heart disease. Some of the contradictions in the literature are also addressed in order to clarify the role of relaxin as an anti-fibrotic factor in vivo.

Mechanisms of relaxin action in the reproductive tract: studies in the relaxin-deficient (Rlx-/-) mouse.

The major functions of relaxin (RLX) are associated with female reproductive tract physiology, namely, the regulation of biochemical processes involved in remodeling of extracellular matrix components in the cervix and vagina at term. Studies in RLX-deficient mice (Rlx-/-) demonstrate that although females give birth to live young without apparent dystocia, the pubic symphysis is not elongated, and they have abnormal cervical and vaginal morphology. The current study examined phenotypic differences in collagen, matrix metalloproteinases (MMP), and estrogen receptors (ERs) in the cervix and vagina of pregnant Rlx+/+ and Rlx-/- mice. Neither collagen nor TGFbeta1 mRNA levels in the cervix and vagina differed significantly between Rlx+/+ and Rlx-/- at any stage of gestation, except on gestation day 18.5, with an increase in alpha(1)-I collagen and TGFbeta1 expression in Rlx-/- mice. MMP gene expression was also increased in Rlx-/- mice, especially at term. Administration of recombinant H2 RLX (0.05 microg/microL/h) to Rlx-/- mice for 6 d from gestation day 12.5 caused a significant decrease in alpha1-I collagen and MMP-13 gene expression in the cervix and vagina, but it had no effect on TGFbeta1. There was also a significant reduction in ERbeta expression in RLX-treated Rlx-/- mice. Interestingly, RLX treatment caused a significant decrease in LGR7 expression in these reproductive tissues. In summary, these data show increases in MMP gene expression in Rlx-/- mice that are not correlated with changes in collagen expression. Furthermore, we report a novel ER phenotype in the cervix and vagina of Rlx-/- mice.

Angiogenic growth factors are new and essential players in the sustained relaxin vasodilatory pathway in rodents and humans.

Relaxin is emerging as an important vasodilator of pregnancy and is being tested for afterload reduction in acute heart failure. However, the mechanisms underlying relaxin-induced vasodilation are incompletely understood. The aims of this study were to establish a new in vitro model for relaxin-induced vasodilation and to use this approach, as well as chronically instrumented, conscious rats, to investigate the role of angiogenic growth factors in the relaxin vasodilatory pathway. Incubation of rat and mouse small renal arteries with recombinant human H2 relaxin for 3 hours in vitro attenuated myogenic constriction, which was blocked by inhibitors of gelatinases, the endothelin B receptor, and NO synthase. These findings corroborate ex vivo observations in arteries isolated from relaxin-infused nonpregnant and midterm pregnant rats, thereby validating the new experimental approach and enabling the study of human arteries. Incubation of small human subcutaneous arteries with relaxin for 3 hours in vitro also attenuated myogenic constriction through the same molecular intermediates. Vascular endothelial growth factor receptor inhibitor SU5416, 3 different vascular endothelial growth factor, and 2 different placental growth factor neutralizing antibodies prevented relaxin from attenuating myogenic constriction in rat and mouse small renal and human subcutaneous arteries. SU5416 administration also prevented relaxin-induced renal vasodilation and hyperfiltration in chronically instrumented, conscious rats. Small renal arteries isolated from these rats demonstrated increased matrix metalloproteinase 2 activity in the relaxin-infused group, which was not prevented by SU5416. We conclude that there is concordance of relaxin vasodilatory mechanisms in rats, mice, and humans, and angiogenic growth factors are novel and essential intermediates.

Relaxin regulates vascular wall remodeling and passive mechanical properties in mice.

Administration of recombinant human relaxin (rhRLX) to conscious rats increases global arterial compliance, and small renal arteries (SRA) isolated from these rats demonstrate increased passive compliance. Here we characterize relaxin-induced vascular remodeling and examine its functional relevance. SRA and external iliac arteries (EIA) were examined in rhRLX-treated (1.0 µg/h for 5 days) and relaxin knockout mice. Arterial geometric remodeling and compositional remodeling were quantified using immunohistochemical and biochemical techniques. Vascular mechanical properties were quantified using an ex vivo preparation wherein pressure-diameter data were obtained at various axial lengths. Compared with vehicle-treated mice, SRA from rhRLX-treated mice showed outward geometric remodeling (increased unstressed wall area and wall-to-lumen area ratio), increased smooth muscle cell (SMC) density, reduction in collagen-to-total protein ratio, and unchanged elastin-to-tissue dry weight ratio. Compared with wild-type mice, relaxin knockout mice exhibited the opposite pattern: decreased unstressed wall area and wall-to-lumen area ratio, decreased SMC density, and increased collagen-to-total protein ratio. Although tissue biaxial strain energy of SRA was not different between rhRLX- and vehicle-treated groups at low-to-physiological circumferential and axial strains, it was lower for the rhRLX-treated group at the highest circumferential strain. In contrast to SRA, relaxin administration was not associated with any vascular remodeling or changes in passive mechanics of EIA. Thus relaxin induces both geometric and compositional remodeling in vessel-specific manner. Relaxin-induced geometric remodeling of SRA is responsible for the increase in passive compliance under low-to-physiological levels of circumferential and axial strains, and compositional remodeling becomes functionally relevant only under high circumferential strain.

Relaxin induces rapid dilation of rodent small renal and human subcutaneous arteries via PI3 kinase and nitric oxide.

The peptide hormone relaxin is a potent vasodilator with therapeutic potential in diseases complicated by vasoconstriction, including heart failure. However, the molecular mediators and magnitude of vasodilation may vary according to duration of exposure and artery type. The objective of these studies was to determine mechanisms of rapid (within minutes) relaxin-induced vasodilation and to examine whether relaxin dilates arteries from different animal species and vascular beds. Rat and mouse small renal, rat mesenteric, and human sc arteries were isolated, mounted in a pressure arteriograph, and treated with recombinant human relaxin (rhRLX; 1-100 ng/ml) after preconstriction with phenylephrine. Rat and mouse small renal as well as human sc arteries dilated in response to rhRLX, whereas rat mesenteric arteries did not. Endothelial removal or pretreatment with l-N(G)-monomethyl arginine (L-NMMA) abolished rapid relaxin-induced vasodilation; phosphatidylinositol-3-kinase (PI3K) inhibitors also prevented it. In cultured human endothelial cells, rhRLX stimulated nitric oxide (assessed using 4-amino-5-methylamino-2'7'-difluorofluorescein) as well as Akt and endothelial NO synthase (eNOS) phosphorylation by Western blotting but not increases in intracellular calcium (evaluated by fura-2). NO production was attenuated by inhibition of Gα(i/o) and Akt (using pertussis toxin and the allosteric inhibitor MK-2206, respectively), PI3K, and NOS. Finally, the dilatory effect of rhRLX in rat small renal arteries was unexpectedly potentiated, rather than inhibited, by pretreatment with the vascular endothelial growth factor receptor inhibitor SU5416. We conclude that relaxin rapidly dilates select arteries across a range of species. The mechanism appears to involve endothelial Gα(i/o) protein coupling to PI3K, Akt, and eNOS but not vascular endothelial growth factor receptor transactivation or increased calcium.

Role of relaxin in maternal systemic and renal vascular adaptations during gestation.

In this paper, the hemodynamic changes of normal pregnancy are reviewed and the underlying hormonal and molecular mechanisms are discussed. Among other findings related to these phenomena, our previous work has demonstrated the importance of relaxin in systemic and renal vascular as well as osmoregulatory changes during gestation. These findings are summarized, and new concepts related to the function of relaxin in blood vessels are presented. Finally, work in progress is briefly outlined.