Effect of Calcium on Slow Force Responses in Isolated Right Ventricle Preparations of Healthy and Hypertrophied Myocardium in Male and Female Rats.

Effect of different Ca2+ concentrations in the bathing solution [Ca2+]o on the parameters of single isometric contraction and slow force response to stretching was studied in isolated preparations of healthy and hypertrophied myocardium of male and female Wistar rats. In all groups of experimental animals, the increase in calcium concentration was followed by a decrease in the myocardium slow response intensity. We revealed a complementary relationship between the current and medium-term systems of myocardial contractility regulation by the length of the myocardium aimed at the maintenance of the constant level during adaptation to the load. Slow responses of the hypertrophied rat heart myocardium were suppressed in comparison with those in the healthy myocardium and their intensity did not depend on animal sex.

Randomized, double-blind, placebo-controlled trial of saw palmetto in men with lower urinary tract symptoms.

OBJECTIVES: To assess the effects of saw palmetto on urinary symptoms, sexual function, and urinary flow rate in men with lower urinary tract symptoms using a double-blind, randomized, placebo-controlled trial. METHODS: The eligible patients were 45 years of age or older and had an International Prostate Symptom Score of 8 or greater. After a 1-month placebo run-in period, 85 men were randomized to receive saw palmetto or placebo for 6 months. Patients were evaluated using the International Prostate Symptom Score, a sexual function questionnaire, and by measurement of the urinary flow rate. RESULTS: The mean symptom score decreased from 16.7 to 12.3 in the saw palmetto group compared with 15.8 to 13.6 in the placebo group (P = 0.038). The quality-of-life score improved to a greater degree in the saw palmetto group, but this difference was not statistically significant. No change occurred in the sexual function questionnaire results in either group. The peak flow rate increased by 1.0 mL/s and 1.4 mL/s in the saw palmetto and placebo groups, respectively (P = 0.73). CONCLUSIONS: Saw palmetto led to a statistically significant improvement in urinary symptoms in men with lower urinary tract symptoms compared with placebo. Saw palmetto had no measurable effect on the urinary flow rates. The mechanism by which saw palmetto improves urinary symptoms remains unknown.

Motor neurons are rich in non-phosphorylated neurofilaments: cross-species comparison and alterations in ALS.

The localization and distribution of non-phosphorylated neurofilaments (NP-NF) in the upper and lower motor neurons was investigated in the rat, the common marmoset, the rhesus monkey and man using the SMI-32 antibody. Within the spinal cord of all species studied, the most intense NP-NF immunoreactivity was observed within the ventral horn alpha-motor neurons. Concurrent staining for the cholinergic marker choline acetyltransferase (ChAT) demonstrated that virtually all of the ChAT-positive alpha-motor neurons contain NP-NF immunoreactivity. Although NP-NF staining was also observed in other neurons within the ventral and intermediate horns, these neurons were loosely scattered and contained a considerably lower staining intensity. The only other prominent NP-NF staining in the spinal cord occurred within the neurons of the dorsal nucleus of Clark and the intermediolateral cell column. Phosphorylated neurofilament (P-NF) immunoreactivity was found primarily in neuronal processes. Occasionally, a solitary motor neuron contained weak P-NF immunoreactivity. Within the brainstem, neurons in all cranial nerve motor nuclei contained intense NP-NF immunoreactivity. The distribution and apparent density of NP-NF immunoreactive neurons in these nuclei was virtually identical to that observed for neurons immunoreactive for ChAT. NP-NF immunoreactive neurons of relatively lower intensity were found in many other regions of the brainstem. All of the giant Betz cells of layer (L) V in the motor cortex contained dark NP-NF immunoreactivity. Within the spinal cord of amyotrophic lateral sclerosis (ALS) patients, both Nissl and NP-NF staining demonstrated the dramatic loss of alpha-motor neurons characteristic of this disorder. Some of the remaining motor neurons contained intense P-NF immunoreactivity. These observations suggest that NP-NF immunoreactivity is a good marker for motor neurons in health and disease and may be a useful tool for studies of motor neuron degeneration (MND).