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Biomedical subjects

P Hanson

Publications and source records attributed to P Hanson.

119 records · Page 7Linked to original sources
PubMedDate not supplied

Constitutive nitric oxide synthases in rat gastric mucosa: subcellular distribution, relative activity and different carboxyl-terminal antigenicity of the neuronal form compared with cerebellum.

BACKGROUND/AIMS: To investigate whether the neuronal form of nitric oxide (NO) synthase (nNOS) in gastric mucosa differed from nNOS in the brain in subcellular distribution or antigenicity, and to determine the relative activity of the endothelial form of NO synthase (eNOS) and nNOS in gastric mucosa. METHODS: Subcellular fractionation, assay of enzyme activity by conversion of arginine to citrulline, and immunoblotting were employed. RESULTS: 10% of NO synthase activity in gastric mucosa was particulate compared with 31% in the cerebellum. Immunoblotting demonstrated that gastric mucosal nNOS protein was essentially cytosolic and that eNOS was largely particulate. Combination of these results with measurements of enzyme activity suggested that 96% of gastric mucosal activity was contributed by nNOS. Experiments with an antiserum raised against the carboxyl-terminal hexadecapeptide of rat brain NO synthase suggested a difference in antigenicity between forms of nNOS from the cerebellum and gastric mucosa. This difference did not seem to result from alternative splicing of the primary transcript, and was not present after enrichment of nNOS by affinity chromatography using 2',5'-ADP agarose. CONCLUSION: The form of nNOS in rat gastric mucosa is largely cytosolic and is the major constitutive activity. When first isolated gastric nNOS differs in antigenicity from the equivalent brain enzyme, probably as a result of an unstable post-translational modification, close to the carboxyl-terminus.

Animals↗
PubMedDate not supplied

A survey of homopteran species (Auchenorrhyncha) from coffee shrubs and poró and laurel trees in shaded coffee plantations, in Turrialba, Costa Rica.

A survey of homopteran species (Auchenorryncha) was conducted in coffee plantations with no shade (C), and in those with shade of either poró (Erythrina poeppigiana) (CP) or poró plus laurel (Cordia alliodora) (CPL), in Turrialba, Costa Rica. A total of 130 species in ten families were collected, dominated by Cicadellidae (82 species). Species richness was highest in the CP system (88), followed by CPL (74) and C systems (60). Five most common species for all systems were Fusigonalia lativittata, Hebralebra nicaraguensis, Neocoelidia sp., Oliarus sp. and Clastoptera sp. Diversification of the coffee agroecosystem favors some species while limiting others, and have no effect on the majority of species. Thus, only F. lativittata, Neocoelidia sp. and Scaphytopius ca. latidens were well represented in all systems, but were more abundant in coffee shrubs. Additionally, the following were the dominant species in each system: Graphocephala sp. 1 (C), F. lativittata (CP) and H. nicaraguensis (CPL). Four species abundant on laurel trees, including H. nicaraguensis, appeared almost exclusively on these tree species. Species similarity was highest on the CP and CPL systems (51% of the species in common), followed by the C and CP (39%) and the C and CPL systems (38%). These findings show that even disturbed systems can harbor many insect species, so that they deserve attention from conservation advocates and biologists.

Animals↗
PubMedDate not supplied

Sympathetic skin response in spinal cord injured patients: preliminary report.

Sympathetic skin responses (SSRs) were recorded in six spinal cord injured patients. These SSRs were obtained at hands and feet, after electrical stimulation of the median or the posterior tibial nerves. Below the level of the lesion, SSRs had similar latencies than normal subjects, but were more inconstant, with a lesser amplitude and elicited after stronger stimulus intensity. The origin of these somatosympathetic reflexes are discussed. SSRs recordings seem to be a simple and suitable technique for investigation of the autonomic nervous system of the spinal cord injured patients.

Adult↗
PubMedDate not supplied

Evaluation of the BAX system for detection of Listeria monocytogenes in foods: collaborative study.

A multilaboratory study was conducted to compare the automated BAX system and the standard cultural methods for detection of Listeria monocytogenes in foods. Six food types (frankfurters, soft cheese, smoked salmon, raw, ground beef, fresh radishes, and frozen peas) were analyzed by each method. For each food type, 3 inoculation levels were tested: high (average of 2 CFU/g), low (average of 0.2 CFU/g) and uninoculated controls. A total of 25 laboratories representing government and industry participated. Of the 2335 samples analyzed, 1109 were positive by the BAX system and 1115 were positive by the standard method. A Chi square analysis of each of the 6 food types, at the 3 inoculation levels tested, was performed. For all foods, except radishes, the BAX system performed as well as or better than the standard reference methods based on the Chi square results.

Chi-Square Distribution↗
PubMedDate not supplied

Studies on factors influencing human plasma alpha-MSH.

The various physiological effects of alpha-MSH, mainly on the CNS and on pigmentation in animal models, are well documented in the literature. Only a few investigators have confirmed similar properties in the human. However, the possible physiopathological role played by this hormone in human melanoma is still poorly defined. In order to approach this subject in a manner as complete as possible, we have performed, during the past four years, three different series of experiments: 1) alpha-MSH measurements in plasma samples from: a. melanoma and other cancer patients, b. whole body UVA irradiated healthy adults, c. circadian rhythm determinations in melanoma patients and in healthy male adults; 2) alpha-MSH measurements in human melanoma tumours; 3) alpha-MSH receptor expression on human melanoma cells in culture involving: a. alpha-MSH radio-binding assays and b. tyrosinase assay. Our results so far show 1) increased alpha-MSH levels in melanoma patients' plasma, alpha-MSH responsiveness to UVA stimulated skin, large immunoreactive alpha-MSH content in melanoma metastases and an alpha-MSH circadian rhythm in some individuals different from cortisol; 2) alpha-MSH receptor expression in melanoma cells could be increased by various effectors able to stimulate melanogenesis.

Aged↗
PubMedDate not supplied

[[The effect of cisapride on the neurogenic bladder].

Cisapride (Prepulsid) is a new prokinetic drug of the gastrointestinal tract. It has indirect muscarinic parasympathicomimetic effects on the neuromuscular junction of smooth muscle that we also observed on the vesical function by four of the six patients presented in this study.

Adult↗