Sexually diergic hypothalamic-pituitary-adrenal axis responses to selective and non-selective muscarinic antagonists prior to cholinergic stimulation by physostigmine in rats.

Central cholinergic systems regulate the hypothalamic-pituitary-adrenal (HPA) axis differentially in males and females (sexual diergism). We previously investigated the role of muscarinic receptors in this regulation by administering physostigmine (PHYSO), an acetylcholinesterase inhibitor, to male and female rats pretreated with scopolamine (SCOP), a nonselective muscarinic antagonist. SCOP pretreatment enhanced adrenocorticotropic hormone (ACTH) and corticosterone (CORT) responses in both sexes, but males had greater ACTH responses while females had greater CORT responses.

Influence of environmental enrichment on hypothalamic-pituitary-adrenal (HPA) responses to single-dose nicotine, continuous nicotine by osmotic mini-pumps, and nicotine withdrawal by mecamylamine in male and female rats.

In the present study, we determined the effects of environmental enrichment (EE; Kong Toys and Nestlets) on sexually diergic HPA axis responses to single-dose nicotine (NIC), single-dose NIC following continuous NIC administration for two weeks, and NIC withdrawal by single-dose mecamylamine (MEC) in male and female rats. Blood sampling occurred before and after MEC and NIC administrations for the determination of adrenocorticotropic hormone (ACTH) and corticosterone (CORT). Supporting and extending our previous findings, EE appeared to produce anxiolytic effects by reducing hormone responses: Male and female rats housed with EE had lower baseline ACTH and significantly lower HPA axis responses to the mild stress of saline (SAL) injection than did those housed without EE.

Intracoronary abciximab and aspiration thrombectomy in patients with large anterior myocardial infarction: the INFUSE-AMI randomized trial.

Context: Thrombus embolization during percutaneous coronary intervention (PCI) in ST-segment elevation myocardial infarction (STEMI) is common and results in suboptimal myocardial perfusion and increased infarct size. Two strategies proposed to reduce distal embolization and improve outcomes after primary PCI are bolus intracoronary abciximab and manual aspiration thrombectomy.

Objective: To determine whether bolus intracoronary abciximab, manual aspiration thrombectomy, or both reduce infarct size in high-risk patients with STEMI.

Sexually diergic hypothalamic-pituitary-adrenal (HPA) responses to single-dose nicotine, continuous nicotine infusion, and nicotine withdrawal by mecamylamine in rats.

Hypothalamic-pituitary-adrenal (HPA) responses to single-dose nicotine (NIC) are sexually diergic: Female rats have higher adrenocorticotropic hormone (ACTH) and corticosterone (CORT) responses than do males. In the present study we determined HPA responses in male and female rats following single doses of NIC, a single-dose of NIC immediately following continuous NIC for two weeks, and NIC withdrawal by single-dose mecamylamine (MEC) following continuous NIC infusion for two weeks. Blood sampling occurred before and after MEC and NIC administrations for the determination of ACTH and CORT.

Pituitary-adrenal responses to oxotremorine and acute stress in male and female M1 muscarinic receptor knockout mice: comparisons to M2 muscarinic receptor knockout mice.

Both within the brain and in the periphery, M(1) muscarinic receptors function primarily as postsynaptic receptors and M(2) muscarinic receptors function primarily as presynaptic autoreceptors. In addition to classical parasympathetic effectors, cholinergic stimulation of central muscarinic receptors influences the release of adrenocorticotrophic hormone (ACTH) and corticosterone. We previously reported that oxotremorine administration to male and female M(2) receptor knockout and wild-type mice increased ACTH to a significantly greater degree in knockout males compared to all other groups, and that M(2) knockout mice of both sexes were significantly more responsive to the mild stress of saline injection than were wild-type mice.

Dual porosity expanded polytetrafluoroethylene for soft-tissue augmentation.

Background: A variety of nondegradable polymers have been evaluated for use as soft-tissue augmentation devices. This study compared a novel dual porosity expanded polytetrafluoroethylene with current, clinically used devices.

Methods: Studies were performed in a porcine model of soft-tissue healing with both histologic evaluations and determination of biomechanical strength of tissue incorporation.

Healing characteristics of hybrid and conventional polytetrafluoroethylene vascular grafts.

The concepts of porosity and healing in vascular grafts are interrelated. The initial phase of healing includes cellular infiltration into the prosthesis followed by tissue ingrowth from perigraft sources. This provides a framework for development of a pseudointima.

Relative magnitude and asynchrony of directional components of contraction in sedated dog left ventricle.

The purpose of this study was to quantitate the temporal relationships and the extent and speed of shortening in segments of myocardium responsive to contraction in circumferential, longitudinal, and oblique fiber groups. Measurements were made in five sedated dogs (morphine, diazepam) with and without alterations in preload and afterload (nitroprusside, phenylephrine). The measurement interval was the phase of rapid contraction, determined by differentiation of the segment length vs.

Failure of nitroglycerin introduced after prolonged myocardial ischemia to improve collateral blood flow and function in tranquilized dogs.

This study investigated whether nitroglycerin can improve ischemic zone blood flow and function when its infusion is delayed following left anterior descending (LAD) occlusion. Nitroglycerin (200 micrograms/min, 11 dogs) or saline (six dogs) was infused for 2 hours starting 2 hours after occlusion. Regional myocardial blood flow (MBF) was measured (9 +/- 1 micron radioactive microspheres) before and at 2 and 4 hours after occlusion.

Transducer system for the noninvasive recording of arterial pressure contours.

A transducer system is described that permits noninvasive recordings of the pressure-vs-time arterial profile at any palpable site on the body. A thin (30 microns) piezoelectric polymer film of polyvinylidene fluoride serves as the active element and as the mechanical coupler to the skin. The system has high frequency response and a low frequency cut-off of 0.

Patterns of cellular injury in myocardial ischemia determined by monoclonal antimyosin.

The development of cellular injury in the rat left ventricle resulting from left coronary artery occlusion was examined by immunofluorescence after intravenous injection of monoclonal antimyosin. Cardiac muscle cells that bound antimyosin during ischemia were localized by staining sections with fluorescein-conjugated anti-mouse IgG. Fluorescent staining was detectable within the ischemic region of the left ventricle 3 hr after occlusion and injection of antimyosin.