PubMed Health⌕ Search

Biomedical subjects

G Behr

Publications and source records attributed to G Behr.

At least 19 recordsLinked to original sources
PubMed2004

Prevalence and service implications of health anxiety in genitourinary medicine clinics.

A comparison of the prevalence of health anxiety in genitourinary medicine (GUM) clinics in two UK centres was carried out using a new rating scale, the Health Anxiety Inventory (HAI). The relationship of health anxiety to demographic and clinical variables, and its impact on service contacts, was also examined in one of these centres. 694 patients were assessed and significant health anxiety was identified in 8-11%. HAI scores were stable over time and high levels persisted in the absence of treatment. Attenders with sexually transmitted infections had significantly lower levels of health anxiety than those with other conditions. Contacts with clinic doctors and health advisors in the nine months before and after assessment were significantly greater in those with high health anxiety, with doctor appointments 37% higher in the high HAI group (P = 0.005). Health anxiety is a source of considerable morbidity in GUM clinics deserving further study.

Adult↗
PubMed2003

Specific properties of fine SnO2 powders connected with surface segregation.

The effect of surface segregation in Sb- and In-doped SnO2 fine-grained powders has been analyzed in comparison with single-crystalline samples. The kinetics and thermodynamics of the Sb and In segregation processes were studied as a function of annealing temperature by X-ray photoelectron spectroscopy (XPS) after annealing in an oxygen-containing atmosphere. Significant differences between diffusion and segregation were revealed for doped powders and single crystals, obviously because of simultaneous diffusion and particle-growth processes proceeding during annealing of powders. For doped single crystals the thermodynamic equilibrium is approached after 24 h annealing above 850 degrees C and at 1000 degrees C for Sb and In, respectively. Higher effective activation energies of diffusion are observed for doped powders and the thermodynamic equilibrium is not achieved under technologically relevant annealing conditions. On the basis of dopant profile measurements anomalies in the electrical resistivity at 300 degrees C of Sb-doped SnO2 powders annealed at 700 and 900 degrees C were attributed to an Sb-depleted zone formed beneath the segregated surface during the kinetic regime. To achieve optimum resistivity behavior for commercial application, inhomogeneous doping of powders must be avoided by appropriate preparation steps.

Journal Article↗
PubMed2003

Infrared response of multiwalled boron nitride nanotubes.

We report the infrared (IR) response of bulk samples of multiwalled boron nitride nanotubes, produced by a substitution reaction from single walled carbon nanotubes, which is dominated by two characteristic BN-vibrations at 800 and 1372 cm-1.

Journal Article↗
PubMed2000

Neuromelanin biosynthesis is driven by excess cytosolic catecholamines not accumulated by synaptic vesicles.

Melanin, the pigment in hair, skin, eyes, and feathers, protects external tissue from damage by UV light. In contrast, neuromelanin (NM) is found in deep brain regions, specifically in loci that degenerate in Parkinson's disease. Although this distribution suggests a role for NM in Parkinson's disease neurodegeneration, the biosynthesis and function of NM have eluded characterization because of lack of an experimental system. We induced NM in rat substantia nigra and PC12 cell cultures by exposure to l-dihydroxyphenylalanine, which is rapidly converted to dopamine (DA) in the cytosol. This pigment was identical to human NM as assessed by paramagnetic resonance and was localized in double membrane autophagic vacuoles identical to NM granules of human substantia nigra. NM synthesis was abolished by adenoviral-mediated overexpression of the synaptic vesicle catecholamine transporter VMAT2, which decreases cytosolic DA by increasing vesicular accumulation of neurotransmitter. The NM is in a stable complex with ferric iron, and NM synthesis was inhibited by the iron chelator desferrioxamine, indicating that cytosolic DA and dihydroxyphenylalanine are oxidized by iron-mediated catalysis to membrane-impermeant quinones and semiquinones. NM synthesis thus results from excess cytosolic catecholamines not accumulated into synaptic vesicles. The permanent accumulation of excess catechols, quinones, and catechol adducts into a membrane-impermeant substance trapped in organelles may provide an antioxidant mechanism for catecholamine neurons. However, NM in organelles associated with secretory pathways may interfere with signaling, as it delays stimulated neurite outgrowth in PC12 cells.

Animals↗
PubMed1987

Mass immunisation campaigns--do they solve the problem?

Mass immunisation campaigns have been successfully used for vaccine delivery in countries such as Brazil and Turkey as well as in a number of instances locally. Although in some circumstances mass campaigns have been advantageous, they are not recommended as a basic policy for South Africa. Immunisation services should be incorporated into routine primary health care delivery as part of maternal and child services. If these services are adequately delivered there would be no need for mass campaigns.

Health Education↗
PubMed1977

A passive method of disposal of expired anaesthetic gases.

A passive method for the disposal of waste anaesthetic gases is described. The resistance characteristics of the collector valve, the balancing device and the disposal system were studied. It was found that the resistances offered by the conduction channels and the terminal exhaust valve were extremely low. The collector valves were found to be responsible for most of the expiratory resistance. Swabs taken from various components of the system showed that these were contaminated mainly with commensals and non-pathogenic organisms.

Air Pollution↗
PubMed1976

Magnesium and potassium content of normal heart muscle in areas of hard and soft water.

Concentrations of both magnesium and potassium were significantly increased in normal heart muscle samples from an area with a soft water supply compared with matched samples from an area with hard water. The zinc contrentration was also slightly increased in the soft water area. The magnesium/potassium ratio was significantly lower in the softwater area. This relative deficiency of magnesium may increase the risk of death after myocardial infarction in soft-water areas.

Adolescent↗
PubMed1974

The nitroblue-tetrazolium test following acute myocardial infarction.

The percentage nitroblue-tetrazolium (NBT) leucocyte levels were evaluated daily in the 10 days following a first attack of coronary thrombosis. In 12 uncomplicated cases the peak increase was on the second or third day; thereafter the level declined and was below 10% by the tenth day. Three other patients did not conform to this pattern of NBT behaviour. They had experienced a second myocardial infarction and this was attended by a secondary rise in the NBT score; in the two survivors the score remained elevated on the tenth day. Comparison of the score on the second-third and tenth-fourteenth days is a possible useful index of a further complication.

Aged↗