Progesterone does not influence vascular function in postmenopausal women

BACKGROUND: The protective functions of oestrogen therapy alone on cardiovascular risk parameters are well established; however, the action of progesterone on vascular parameters in an oestrogen-deprived environment is less clear. OBJECTIVES: To examine the effects of progesterone alone on vascular function and hormone levels in postmenopausal women. DESIGN: In a randomized, double-blind, cross-over design study, 20 healthy postmenopausal women were tested before and after 6 weeks of treatment with micronized progesterone (100 mg/daily) and matching placebo. METHODS: Tests included measurement of sex hormones and gonadatropin levels, lipids and measures of surrogate markers of vascular function including, blood pressure, flow-mediated dilation of the brachial artery, systemic arterial compliance and cutaneous vascular reactivity. RESULTS: The mean (+/- SEM) age of subjects was 56.4 +/- 2.7 years and the average body mass index at the baseline visit was 27.1 +/- 1.0 kg/m2. Progesterone levels increased as a result of progesterone treatment (0.9 +/- 0.2 to 9.5 +/- 2.3 nmol/l, P = 0.001), whereas follicle-stimulating hormone levels decreased (75.1 +/- 11.4 to 67.6 +/- 10.0, P = 0.001). Systemic arterial compliance, flow mediated dilation, cutaneous vascular reactivity, blood pressure, body mass index, plasma levels of cholesterol, lipids and oestrogen were unchanged. CONCLUSIONS: We conclude that progesterone given without oestrogen does not adversely affect vascular function in postmenopausal women.     

Postmenopausal Hormone Therapy: Does It Have a Role in Cardiovascular Prevention Today?

Cardiovascular disease is the leading cause of mortality in women. Results from observational studies consistently demonstrated lower heart disease rates among women who used hormone replacement therapy (HRT) compared to non-users. Data from two large randomized controlled trials showed mixed results. Subsequent post-hoc analysis found cardiovascular disease among HRT users to be lower than non-users in women 50 to 59 years of age or less than 10 years post-menopause. This has sparked much debate on the role of postmenopausal hormone therapy, especially in peri-menopausal women. Two hypotheses have been suggested to explain this divergent data: 1) HRT may be cardioprotective when introduced prior to atherosclerosis development but may be harmful in women with established CVD; or 2) HRT may be useful when started closer to menopause initiation and harmful when started later in life.     

Evaluation of acute cervical spine imaging based on ACR Appropriateness Criteria?

The objectives of this study were to determine the rate of acute blunt cervical spine injury at an academic urban level 1 trauma center and to evaluate the utilization of cervical spine imaging based on the established American College of Radiology (ACR) Appropriateness Criteria?. We retrospectively reviewed all radiography and CT imaging of the cervical spine performed over a year period in adult patients presenting with acute blunt cervical spine trauma. Exclusion criteria were children ≤17 years, non-acute trauma of ≥72 h, and penetrating trauma. Any fracture, dislocation, or ligamentous instability demonstrated by diagnostic imaging and requiring stabilization or specialized follow-up was defined as clinically significant cervical spine injury. A total of 1,325 cervical spine studies were reviewed in 1,245 patients; 32.7% (433/1,325) were cervical spine radiographs and 67.3% (892/1,325) were CT examinations. Approximately 1.5% (19/1,245) of the patients demonstrated clinically significant acute cervical spine injury. There were 6.4% (80/1,245) patients who received both cervical spine radiographs and CT as imaging evaluation. Based on the ACR Appropriateness Criteria?, all of the cervical spine radiographs performed (433) were determined to be “inappropriate” imaging in the setting of acute cervical spine injury.     

Photoacoustic and Fluorescence Image-Guided Surgery Using a Multifunctional Targeted Nanoprobe

Purpose

A complete surgical excision with negative tumor margins is the single most important factor in the prediction of long-term survival for most cancer patients with solid tumors. We hypothesized that image-guided surgery using nanoparticle-enhanced photoacoustic and fluorescence imaging could significantly reduce the rate of local recurrence.

Methods

A murine model of invasive mammary carcinoma was utilized. Three experimental groups were included: (1) control; (2) tumor-bearing mice injected with non-targeted nanoprobe; and (3) tumor-bearing mice injected with targeted nanoprobe. The surgeon removed the primary tumor following the guidance of photoacoustic imaging (PAI), then inspected the surgical wound and removed the suspicious tissue using intraoperative near-infrared (NIR) fluorescence imaging. The mice were followed with bioluminescence imaging weekly to quantify local recurrence.

Results

Nanoprobe-enhanced photoacoustic contrast enabled PAI to map the volumetric tumor margins up to a depth of 31 mm. The targeted nanoparticles provided significantly greater enhancement than non-targeted nanoparticles. Seven mice in the group injected with the targeted nanoprobes underwent additional resections based upon NIR fluorescence imaging. Pathological analysis confirmed residual cancer cells in the re-resected specimens in 5/7 mice. Image-guided resection resulted in a significant reduction in local recurrence; 8.7 and 33.3 % of the mice in the targeted and control groups suffered recurrence, respectively.

Conclusions

These results suggest that photoacoustic and NIR intraoperative imaging can effectively assist a surgeon to locate primary tumors and to identify residual disease in real-time. This technology has promise to overcome current clinical challenges that result in the need for second surgical procedures.     

Impact of the COVID-19 pandemic on hyperacute stroke treatment: experience from a comprehensive stroke centre in Singapore

The Coronavirus disease 2019 (COVID-19) pandemic is rapidly evolving and affecting healthcare systems across the world. Singapore has escalated its alert level to Disease Outbreak Response System Condition (DORSCON) Orange, signifying severe disease with community spread. We aimed to study the overall volume of AIS cases and the delivery of hyperacute stroke services during DORSCON Orange. This was a single-centre, observational cohort study performed at a comprehensive stroke centre responsible for AIS cases in the western region of Singapore, as well as providing care for COVID-19 patients. All AIS patients reviewed as an acute stroke activation in the Emergency Department (ED) from November 2019 to April 2020 were included. System processes timings, treatment and clinical outcome variables were collected. We studied 350 AIS activation patients admitted through the ED, 206 (58.9%) pre- and 144 during DORSCON Orange. Across the study period, number of stroke activations showed significant decline (p?=?0.004, 95% CI 6.513 to???2.287), as the number of COVID-19 cases increased exponentially, whilst proportion of activations receiving acute recanalization therapy remained stable (p?=?0.519, 95% CI???1.605 to 2.702). Amongst AIS patients that received acute recanalization therapy, early neurological outcomes in terms of change in median NIHSS at 24 h (-4 versus -4, p?=?0.685) were largely similar between the pre- and during DORSCON orange periods. The number of stroke activations decreased while the proportion receiving acute recanalization therapy remained stable in the current COVID-19 pandemic in Singapore.