Jove
Visualize
Contact Us
JoVE
x logofacebook logolinkedin logoyoutube logo
ABOUT JoVE
OverviewLeadershipBlogJoVE Help Center
AUTHORS
Publishing ProcessEditorial BoardScope & PoliciesPeer ReviewFAQSubmit
LIBRARIANS
TestimonialsSubscriptionsAccessResourcesLibrary Advisory BoardFAQ
RESEARCH
JoVE JournalMethods CollectionsJoVE Encyclopedia of ExperimentsArchive
EDUCATION
JoVE CoreJoVE BusinessJoVE Science EducationJoVE Lab ManualFaculty Resource CenterFaculty Site
Terms & Conditions of Use
Privacy Policy
Policies

Related Concept Videos

The Placebo Effect01:54

The Placebo Effect

5.9K
The placebo effect occurs when people's expectations or beliefs influence or determine their experience in a given situation. In other words, simply expecting something to happen can actually make it happen.
5.9K
Clinical Trials: Overview01:11

Clinical Trials: Overview

4.7K
Clinical development focuses on how the drug will interact with the human body and encompasses four key phases of clinical trials, each serving a specific purpose in assessing the safety and effectiveness of new drugs. These phases overlap and build upon one another. Phase I involves a small group of healthy volunteers (typically 20-80 individuals) or, in cases where significant toxicity is expected, patients with the targeted disease, such as cancer or AIDS. The volunteers are tested for...
4.7K
Heart Failure Drugs: Inhibitors of Renin-Angiotensin System01:26

Heart Failure Drugs: Inhibitors of Renin-Angiotensin System

1.9K
The activation of the sympathetic nervous system and the renin-angiotensin-aldosterone system (RAAS) contributes to cardiac remodeling, and inhibiting the RAAS is a pharmacological target in heart failure management. As a result, neurohumoral modulation is a crucial treatment principle for managing heart failure. This approach involves using medications like ACE inhibitors (ACEIs), angiotensin receptor blockers (ARBs), β-blockers, mineralocorticoid receptor antagonists (MRAs), and neutral...
1.9K
Heart Failure Drugs: β-Blockers01:22

Heart Failure Drugs: β-Blockers

2.7K
β-adrenergic antagonists, commonly known as β-blockers, block the effects of sympathetic neurotransmitters such as noradrenaline (NA) and adrenaline (ADR). They have several beneficial effects in heart failure treatment. They reduce heart rate, the force of contraction, and cardiac muscle relaxation. They also slow the atrial-ventricular conduction rate and raise the threshold for arrhythmias. The concentration of β-blockers determines their effects on bronchodilation,...
2.7K
Hormonal Control of the Ovarian Cycle01:30

Hormonal Control of the Ovarian Cycle

5.1K
The ovarian cycle is meticulously regulated by the hypothalamic-pituitary-gonadal axis. This cycle orchestrates the release of a mature oocyte, essential for reproduction.
Before puberty, the hypothalamus releases GnRH in a low frequency, low amplitude pulsatile manner. This along with the immature hypothalamic-pituitary-gonadal axis activity, results in low estrogen levels and the absence of a fully functional ovarian cycle.  At puberty, GnRH secretion increases in both frequency and...
5.1K
Hazard Ratio01:12

Hazard Ratio

756
The hazard ratio (HR) is a widely used measure in clinical trials to compare the risk of events, such as death or disease recurrence, between two groups over time. It reflects the ratio of hazard rates—the instantaneous risk of the event occurring—between a treatment group and a control group. This measure provides valuable insights into the relative effectiveness of a treatment by assessing how the risk of an event differs between the two groups.
For example, in a clinical trial...
756

You might also read

Related Articles

Articles linked to this work by shared authors, journal, and citation graph.

Sort by
Same author

The association of calcium supplementation and incident cardiovascular events in the Multi-ethnic Study of Atherosclerosis (MESA).

Nutrition, metabolism, and cardiovascular diseases : NMCD·2016
Same author

C-reactive protein concentration predicts mortality in type 2 diabetes: the Diabetes Heart Study.

Diabetic medicine : a journal of the British Diabetic Association·2012
Same author

The relationship between inflammation, obesity and risk for hypertension in the Multi-Ethnic Study of Atherosclerosis (MESA).

Journal of human hypertension·2010
Same author

The minor allele of GP6 T13254C is associated with decreased platelet activation and a reduced risk of recurrent cardiovascular events and mortality: results from the SMILE-Platelets project.

Journal of thrombosis and haemostasis : JTH·2010
Same author

Endothelial dysfunction is associated with left ventricular mass (assessed using MRI) in an adult population (MESA).

Journal of human hypertension·2010
Same author

Genetic epidemiology of subclinical cardiovascular disease in the diabetes heart study.

Annals of human genetics·2008

Related Experiment Video

Updated: May 5, 2026

Ovariectomy and 17β-estradiol Replacement in Rats and Mice: A Visual Demonstration
06:51

Ovariectomy and 17β-estradiol Replacement in Rats and Mice: A Visual Demonstration

Published on: June 7, 2012

58.0K

The HERS trial results: paradigms lost? Heart and Estrogen/progestin Replacement Study.

D M Herrington1

  • 1Department of Internal Medicine/Cardiology, Wake Forest University School of Medicine, Winston-Salem, North Carolina 27157-1045, USA. dherring@wfubmc.edu

Annals of Internal Medicine
|September 25, 1999
PubMed
Summary

The Heart and Estrogen/progestin Replacement Study (HERS) showed no overall benefit of hormone therapy for secondary prevention of heart disease. However, early cardiovascular events increased, followed by a later decrease in the hormone therapy group.

More Related Videos

Protocol for Studying Extinction of Conditioned Fear in Naturally Cycling Female Rats
09:07

Protocol for Studying Extinction of Conditioned Fear in Naturally Cycling Female Rats

Published on: February 23, 2015

13.3K
An In Vivo Estrogen Deficiency Mouse Model for Screening Exogenous Estrogen Treatments of Cardiovascular Dysfunction After Menopause
06:18

An In Vivo Estrogen Deficiency Mouse Model for Screening Exogenous Estrogen Treatments of Cardiovascular Dysfunction After Menopause

Published on: August 13, 2019

11.7K

Related Experiment Videos

Last Updated: May 5, 2026

Ovariectomy and 17β-estradiol Replacement in Rats and Mice: A Visual Demonstration
06:51

Ovariectomy and 17β-estradiol Replacement in Rats and Mice: A Visual Demonstration

Published on: June 7, 2012

58.0K
Protocol for Studying Extinction of Conditioned Fear in Naturally Cycling Female Rats
09:07

Protocol for Studying Extinction of Conditioned Fear in Naturally Cycling Female Rats

Published on: February 23, 2015

13.3K
An In Vivo Estrogen Deficiency Mouse Model for Screening Exogenous Estrogen Treatments of Cardiovascular Dysfunction After Menopause
06:18

An In Vivo Estrogen Deficiency Mouse Model for Screening Exogenous Estrogen Treatments of Cardiovascular Dysfunction After Menopause

Published on: August 13, 2019

11.7K

Area of Science:

  • Cardiovascular Medicine
  • Endocrinology
  • Women's Health

Background:

  • The Heart and Estrogen/progestin Replacement Study (HERS) investigated hormone therapy for secondary prevention of coronary heart disease.
  • Observational studies suggested cardiovascular benefits of estrogen, contrasting with initial HERS findings.

Purpose of the Study:

  • To interpret the complex HERS results regarding hormone therapy's cardiovascular effects in postmenopausal women.
  • To reconcile the HERS findings with other studies on estrogen and cardiovascular health.

Main Methods:

  • Analysis of the HERS trial data examining cardiovascular events over 4.1 years.
  • Evaluation of the temporal pattern of risk within the hormone therapy and placebo groups.

Main Results:

  • No overall effect of estrogen plus progestin therapy on secondary prevention of coronary heart disease.
  • An initial 50% increase in cardiovascular events during the first year of therapy.
  • A subsequent reduction in events after 2 years compared to placebo.

Conclusions:

  • The observed pattern of early risk increase and late risk reduction requires further investigation.
  • Potential explanations include cohort attrition of susceptible individuals and beneficial effects like lipid lowering.
  • HERS highlights the need for rigorous clinical trials to assess hormone replacement therapy's cardiovascular benefits and risks.