The effect of ACTH on the blood clearance rate of aldosterone, cortisol, 17 alpha-hydroxyprogesterone and 17 alpha, 20 alpha-dihydroxy-4-pregnen-3-one in the sheep

The blood clearance rate (BCR) of aldosterone, cortisol, 17 alpha-hydroxyprogesterone (17 alpha OHP) and 17 alpha, 20 alpha-dihydroxy-4-pregnen-3-one (17 alpha 20 alpha OHP) has been measured in conscious sheep prior to and after 5 or 6 days ACTH treatment. ACTH increased the BCR of cortisol but did not change the BCR of the other three steroids. 17 alpha OHP had a BCR greater than liver blood flow suggesting extra-hepatic metabolism. In vivo conversion of 17 alpha OHP to 17 alpha 20 alpha OHP by ovine red cells has been shown to be a significant site of this metabolism. It is suggested that this conversion of 17 alpha OHP to 17 alpha 20 alpha OHP may be important in the expression of the "hypertensionogenic" effect of 17 alpha OHP.     

The 20th anniversary of proteomics and some of its origins

The term “proteome” was first introduced into the scientific literature in July 1995. Almost 20 years ago attempts to characterize the “total protein complement able to be encoded by a given genome” only became possible due to privileged access to what were then the world's most complete sets of genomic data. Today, proteomics has become an important pillar in the fields of disease diagnosis and drug research and development, while also playing a critical role in the much larger field of Healthcare Analytics and Biomarker Discovery and Detection. It is important to note that this industry originated mostly from building blocks in analytical science that predated the term “proteomics” by many decades. However, proteomics, as a discipline, has allowed protein scientists to more favorably compete in the face of highly fashionable Big Science and, more specifically, genomics.     

Seabed photography,environmental assessment and evidence for deep-water trawling on the continental margin west of the Hebrides

Little is known about marine filamentous fungi and yeasts, almost nothing about their life and metabolism under deep sea conditions. Data on growth and metabolic activity give insight into the role of organisms in the marine habitat. Degradation studies on pollutants, such as polymeric thermoplasts, provide information about the self-cleaning capacity of a habitat. Therefore, recently isolated fungal strains from the deep sea and our newly developed methods and apparatus for investigation of fungi under simulated deep sea conditions were used to study fungal growth and degradation of a commercially produced thermoplastic polymer (poly--hydroxybutyric acid = PHB). Two deep sea isolates, a filamentous fungus (Aspergillus ustus) and one yeast (Rhodosporidium sphaerocarpum), and for comparison, two marine surface yeast isolates (Candida guilliermondii, Debaryomyces hansenii) and one terrestrial isolate of Aspergillus ustus were investigated. Growth (colony-forming units, dry weight), physiological parameters (oxygen saturation of the hydraulic fluid as oxygen reservoir, pH and consumption of total carbohydrate) and PHB degradation (clearing test: clearing of PHB-turbid agar medium; spectrophotometric test: PHB depolymerase activity) were followed after incubation in high-pressure autoclaves in artificial seawater medium at 27 °C and pressures of 0.1 MPa (= atmospheric pressure), 5 MPa, 10 MPa, 20 MPa, 30 MPa, 45 or 50 MPa and 100 MPa ( 10000 m water depth) for a maximum of 21 days (yeasts) and 28 days (filamentous fungi), respectively. Irrespective of the marine or terrestrial origin of the isolates, growth decreased with increasing pressure with a limit between 30 MPa and 50 MPa for filamentous fungi and yeasts. Metabolic activity (consumption of medium components) started to decrease from 20 MPa, ceasing at growth-limiting pressures. Under atmospheric conditions, all strains degraded PHB in solid medium, in liquid medium degradation was less and decreased further and/or was delayed with increasing hydrostatic pressure; beyond 30 MPa, no PHB degradation could be observed. In summary, it could be shown that growth, metabolism and degradation of pollutants such as PHB by marine fungal isolates was impaired with increasing pressure, showing one aspect of the reduced self-cleaning capacity of the deep sea habitat.Dedicated to Prof. Dr Jan Kohlmeyer, Morehead City, USA, on the occasion of his 70th anniversary     

Biosafety of an Experimentally Proven Mosquito Vector Pathogen,Spiroplasma taiwanense

A candidate biocontrol agent of mosquito vectors Spiroplasma taiwanense, was demonstrated not to persist (31 days post‐inoculation) or to reduce body weight of intra‐cerebrally inoculated suckling Swiss mice or suckling Sprague‐Dawley rats. It did not multiply or persist in mouse neuroblastoma 2A cells in vitro, nor did it reduce survival of the domestic honey bee Apis mellifera caucasica (a beneficial insect species). Preparations of this organism used throughout this study were verified for pathogenicity in female Aedes aegypti mosquitoes. S. taiwanense, originally isolated from mosquitoes, may thus prove to possess pathogenicity restricted to mosquitoes. S. melliferum was used as a positive control for intra‐cerebral re‐isolation and pathogenicity in mice, rats and mouse neuroblastoma cells.     

Changes in the relationship between cerebrospinal fluid and blood composition produced by ACTH treatment in conscious sheep

It has been proposed that an increase in CSF osmolality could be involved in the genesis of hypertension by activation of central nervous system receptors involved in cardiovascular regulation. ACTH induced hypertension in the sheep is an adrenally dependent model of steroid induced hypertension. This study reports the effect of ACTH administration (20 g/kg/day) for 5 days on the composition of cerebrospinal fluid (CSF) and blood (plasma) in conscious sheep. ACTH increased CSF and plasma osmolality within 24 h associated with parallel increases in both blood and CSF glucose concentrations and plasma and CSF sodium concentration. Plasma potassium fell within 24 h, but CSF potassium did not change over the 5 days of ACTH treatment. Neither calcium nor magnesium changed in either plasma or CSF. CSF phosphate increased and plasma phosphate decreased. CSF and plasma bicarbonate were elevated with ACTH. Plasma chloride decreased after 5 days of ACTH treatment but was not associated with a change in CSF. The relevance of the measured changes in CSF osmolality and composition to the mechanisms involved in the production of ACTH-induced hypertension will be subject of further experimentation.