Sperm nitric oxide and motility: the effects of nitric oxide synthase stimulation and inhibition

Nitric oxide (NO) is synthesized from L-arginine by a family of enzymes known as the nitric oxide synthases (NOS). We have recently shown a NOS similar to constitutive brain NOS (bNOS) and endothelial NOS (ecNOS) to be present in spermatozoa. The aim of this study is to investigate NO production by human spermatozoa and the effects of stimulation and inhibition of NOS. This was carried out using the Iso-NO, an isolated NO meter and sensor, which provides rapid, accurate and direct measurements of NO. Semen samples with normozoospermic and asthenozoospermic profiles were prepared using a direct swim-up technique. Basal concentrations of NO and stimulated NO production were measured after exposure to the calcium ionophore (A23187; 0.01-10 microM) a potent activator of constitutive NOS. NO production in human spermatozoa was significantly increased by the addition of A23187 30 seconds after stimulation. Furthermore, this response was greatly diminished by pre-incubating the samples with competitive inhibitors of L-arginine, the substrate for NOS, before treatment with calcium ionophore. In the presence of N(G)-nitro-L-arginine methyl ester (L- NAME), N(G)-nitro-L-arginine (L-NA) or N(G)-methyl-L-arginine (L-NMMA; all at 10 microM), NO production was inhibited with a rank order of potency L-NAME > L-NMMA > L-NA which is in accordance with the inhibition of an endothelial type of constitutive NOS.      

Primary care anticoagulant clinic management using computerized decision support and near patient International Normalized Ratio (INR) testing: routine data from a practice nurse-led clinic

BACKGROUND: Increasing indications for warfarin therapy has led to increased pressure on primary care to undertake therapeutic monitoring. OBJECTIVE: This study evaluates a primary care model of oral anticoagulation monitoring which utilises computerized decision support (CDSS) and near patient testing (NPT) within a practice nurse-led clinic. Whilst this has been shown to be a successful model under trial conditions, this paper reports the first data from a long-standing clinic, outside a formal study. METHOD: A prospective evaluation of therapeutic and clinical control of all patients taking warfarin within one inner city general practice. Data were collected via CDSS. RESULTS: 29 patients were seen in 208 appointments. The mean percentage of patients within therapeutic range was 72%. The costs to the practice were pound sterling 1751. The costs the practice would have incurred had these patients been seen at the hospital with the same frequency would have been pound sterling 2290. CONCLUSIONS: The use of CDSS and NPT for nurse-delivered oral anticoagulation monitoring could enable the safe transfer of the majority of patients from secondary to primary care. Funding mechanisms to support the transfer of costs will be essential for most practices, as will be the maintenance of adequate staff training and quality assurance.      

Diffuse Lewy body disease and progressive dementia

Thirty cases of diffuse Lewy body disease (DLBD) have been reported, primarily by neuropathologists, but an associated clinical syndrome has not been clearly defined. Four recent cases have led us to examine the clinicopathologic correlations. Patients are usually elderly, with symptoms lasting from 1 to 20 years. Progressive dementia or psychosis is typically the first and most prominent feature. Parkinsonian signs, initially mild or absent, become common eventually, and rigidity is usually severe. Involuntary movements, myoclonus, quadriparesis in flexion, orthostatic hypotension, and dysphagia have also been noted. Classic, concentric Lewy bodies are found profusely in the brainstem, basal forebrain, and hypothalamic nuclei, while less well defined "Lewy-like" bodies occur in limbic structures and in deep neocortical layers. In addition, focal spongiform changes in the mesial temporal lobe were found in two of our cases. We suggest that DLBD may be another specific cause of progressive dementia.