Protein primary structure correlates with calcium oxalate stone matrix preference.

Despite the apparent importance of matrix proteins in calcium oxalate kidney stone formation, the complexity of the protein mixture continues to elude explanation. Based on a series of experiments, we have proposed a model where protein aggregates formed from a mixture containing both strongly charged polyanions and strongly charged polycations could initiate calcium oxalate crystal formation and crystal aggregation to create a stone. These protein aggregates also preferentially adsorb many weakly charged proteins from the urine to create a complex protein mixture that mimics the protein distributions observed in patient samples.

Factors associated with long-term survival in patients with stroke after coronary artery bypass grafting.

Objective: Occurrence of a stroke within 30 days following coronary artery bypass grafting (CABG) is an uncommon, but often devastating, complication. This study aimed to identify factors associated with long-term survival (beyond 30 days) in patients with stroke after CABG.

Methods: De-identified patients' records from the Veterans Affairs Surgical Quality Improvement Program database were used to identify risk factors and perioperative complications associated with survival for up to 20 years in patients with post-CABG stroke.

Thermal pain perception after aerobic exercise.

Objective: To examine thermal pain perception before, 5 minutes after, and 30 minutes after 30 minutes of treadmill exercise at 75% of maximal oxygen uptake (V o 2 max).

Design: Repeated-measures.

Setting: Sports science laboratory.

Regulation by macromolecules of calcium oxalate crystal aggregation in stone formers.

Based on the structure of kidney stones, it is likely that they form as aggregations of preformed crystals, mostly calcium oxalate monohydrate (COM). In this study, we examined the ability of a macromolecular mixture isolated from the urine of normal individuals and stone formers to inhibit aggregation of preformed COM seed crystals in a simple ionic solution using measurements of changes in the particle size distribution (PSD) of preformed COM crystal aggregates. We also examined the effect in this assay of a number of synthetic homopolymers, naturally occurring urine macromolecules, and binary mixtures thereof.

Intensity and duration threshold for aerobic exercise-induced analgesia to pressure pain.

Objective: To examine how exercise-induced analgesia is affected by the duration and intensity of aerobic exercise.

Design: Repeated-measures design.

Setting: Exercise science laboratory.

Osteopontin is a critical inhibitor of calcium oxalate crystal formation and retention in renal tubules.

Calcium nephrolithiasis is the most common form of renal stone disease, with calcium oxalate (CaOx) being the predominant constituent of renal stones. Current in vitro evidence implicates osteopontin (OPN) as one of several macromolecular inhibitors of urinary crystallization with potentially important actions at several stages of CaOx crystal formation and retention. To determine the importance of OPN in vivo, hyperoxaluria was induced in mice targeted for the deletion of the OPN gene together with wild-type control mice.

Functional anatomy of the vagal innervation of the cervical trachea of the dog.

The canine cervical trachea has been used for numerous studies regarding the neural control of tracheal smooth muscle. The purpose of the present study was to determine whether there is lateral dominance by either the left or right vagal innervation of the canine cervical trachea. In anesthetized dogs, pressure in the cuff of the endotracheal tube was used as an index of smooth muscle tone in the trachea.

Acute cross-tolerance to opioids in heroin delta-opioid-responding Swiss Webster mice.

It is generally thought that the mu receptor actions of metabolites, 6-monoacetylmorphine (6MAM) and morphine, account for the pharmacological actions of heroin. However, upon intracerebroventricular (i.c.

Rapid vasodilation in response to a brief tetanic muscle contraction.

To test the hypothesis that vasodilation occurs because of the release of a vasoactive substance after a brief muscle contraction and to determine whether acetylcholine spillover from the motor nerve is involved in contraction-induced hyperemia, tetanic muscle contractions were produced by sciatic nerve stimulation in anesthetized dogs (n = 16), instrumented with flow probes on both external iliac arteries. A 1-s stimulation of the sciatic nerve at 1. 5, 3, and 10 times motor threshold increased blood flow above baseline (P < 0.

What is causing your patient's sexual dysfunction? Uncovering a connection with hypertension and antihypertensive therapy.

Arterial hypertension is associated with structural and functional alterations of the vessel walls. Because vascular endothelium plays a central role in the control of vascular tone, endothelial dysfunction can also cause certain types of erectile dysfunction. Erectile dysfunction is also a common side effect of certain drugs, including many antihypertensive agents.

Autonomic control of skeletal muscle vasodilation during exercise.

Despite extensive investigation, the control of blood flow during dynamic exercise is not fully understood. The purpose of this study was to determine whether beta-adrenergic or muscarinic receptors are involved in the vasodilation in exercising skeletal muscle. Six mongrel dogs were instrumented with ultrasonic flow probes on both external iliac arteries and with a catheter in a branch of one femoral artery.