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Biomedical subjects

P Buchholz

Publications and source records attributed to P Buchholz.

At least 19 recordsLinked to original sources
PubMed2007

Quality of life and relative importance: a comparison of time trade-off and conjoint analysis methods in patients with age-related macular degeneration.

AIM: To investigate the relative priorities in quality of life (QoL) in patients with age-related macular degeneration (AMD). METHODS: Measures of visual function, QoL and utility associated with visual loss were obtained from 122 patients with AMD classified according to macular morphology. The two methods of utility assessment were time trade-off (TTO) and conjoint analysis (CA), which have been recommended by the UK's National Institute of Clinical Excellence as techniques for the assessment of healthcare priorities. RESULTS: Results show that the two methods for assessing utility are poorly related: TTO relates moderately to visual function and disease severity but CA does not. CA identified two different subgroups of patients: one with outdoor mobility and the other with reading as their main priority. CONCLUSION: Further work is needed and caution required in interpreting data obtained using these methodologies for determining their relative importance in vision-related QoL studies.

Activities of Daily Living↗
PubMed2005

Detection and imaging of atmospheric radio flashes from cosmic ray air showers.

The nature of ultrahigh-energy cosmic rays (UHECRs) at energies >10(20) eV remains a mystery. They are likely to be of extragalactic origin, but should be absorbed within approximately 50 Mpc through interactions with the cosmic microwave background. As there are no sufficiently powerful accelerators within this distance from the Galaxy, explanations for UHECRs range from unusual astrophysical sources to exotic string physics. Also unclear is whether UHECRs consist of protons, heavy nuclei, neutrinos or gamma-rays. To resolve these questions, larger detectors with higher duty cycles and which combine multiple detection techniques are needed. Radio emission from UHECRs, on the other hand, is unaffected by attenuation, has a high duty cycle, gives calorimetric measurements and provides high directional accuracy. Here we report the detection of radio flashes from cosmic-ray air showers using low-cost digital radio receivers. We show that the radiation can be understood in terms of the geosynchrotron effect. Our results show that it should be possible to determine the nature and composition of UHECRs with combined radio and particle detectors, and to detect the ultrahigh-energy neutrinos expected from flavour mixing.

Journal Article↗
PubMed2005

The cost-effectiveness of bimatoprost 0.03% in the treatment of glaucoma in adult patients--a European perspective.

Glaucoma is a condition affecting one or both eyes with raised intraocular pressure (IOP). IOP should be reduced to prevent progression of visual field loss. This study investigates the cost-effectiveness of bimatoprost compared with latanoprost as first-line monotherapies in the treatment of glaucoma in Austria, Finland and France. On the basis of a single multicentre, randomised, investigator-masked controlled trial, a 6- and 12-month cost-effectiveness model was designed following the treatment recommendations from the European Glaucoma Society. Treatment changes due to insufficient IOP reduction and adverse events were included. The cost-effectiveness analysis showed that the need for adjunctive therapy was the major cost driver. On the basis of evidence from the randomised, investigator-masked clinical trial (RCT), the cost-effectiveness analysis found that bimatoprost was a cheaper and a more effective treatment strategy compared with latanoprost. This was true for all three countries and all IOP targets between 13 and 20 mmHg. The cost-effectiveness result may be generalised to a European setting and perspective.

Amides↗
PubMed2004

Limits for the central production of Theta+ and Xi(--)pentaquarks in 920-GeV pA collisions.

We have searched for Theta+(1540) and Xi(--)(1862) pentaquark candidates in proton-induced reactions on C, Ti, and W targets at midrapidity and square root of s = 41.6 GeV. In 2 x 10(8) inelastic events we find no evidence for narrow (sigma approximately 5 MeV) signals in the Theta+ --> pK0(S) and Xi(--) --> Xi- pi- channels; our 95% C.L. upper limits (UL) for the inclusive production cross section times branching fraction B dsigma/dy/(y approximately 0) are (4-16) mub/N for a Theta+ mass between 1521 and 1555 MeV, and 2.5 mub/N for the Xi(--). The UL of the yield ratio of Theta+/Lambda(1520) < (3-12)% is significantly lower than model predictions. Our UL of B Xi(--)/Xi(1530)0 < 4% is at variance with the results that have provided the first evidence for the Xi(--).

Journal Article↗
PubMed1994

[Tuberculosis of the CNS--once again a current neurosurgical disease].

Tuberculosis is relative uncommon in developed countries. The incidence is still considerable in India, in the Middle East and South America. Neurosurgically important manifestations of tuberculosis are intracranial tuberculomas, tuberculous meningitis with hydrocephalus and tuberculous spondylitis. Therefore experiences in the management of these three kinds of neurotuberculosis are described and an overview of the literature is given. The diagnosis of intracranial tuberculomas is difficult because the symptoms are similar to those of many other types of intracranial tumor and the CT-findings are unspecific. Clinical recognition of neurotuberculosis rests mainly on the evidence of the general disease. A positive skin test supports the diagnosis. The management of tuberculomas enclosed stereotactic biopsy to confirm the diagnosis, medical treatment and surgery. But surgery is only indicated for larger symptomatic mass lesions producing midline shift and severe intracranial hypertension. With antituberculous drugs treated tuberculomas begin to decrease in size within the first two months of therapy. Hydrocephalus is a common complication of tuberculous meningitis. Due to the low incidence the first diagnosis in industrialized countries is a hydrocephalus of unknown origin. The diagnosis of tuberculous meningitis is suspected in any case of subacute meningitis with a CSF profile demonstrating a predominance of lymphocytes, elevated protein value, hypoglycaemia and negative stains for bacterial or fungal organisms, because positive smears for acid-fast bacilli are seldom. Without treatment, tuberculous meningitis is invariably fatal within 4 to 6 weeks. Therefore, when ever tuberculous meningitis is suspected, antituberculous therapy must be started.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1993

Epidemiological study of an Acinetobacter baumannii outbreak by using polymerase chain reaction fingerprinting.

A polymerase chain reaction (PCR) technique was applied to the fingerprinting of different strains of Acinetobacter baumannii from a cluster of patients infected or colonized with the incriminated pathogen. The DNA was extracted by boiling and was subjected to PCR amplification by using the core sequence of the M13 phase as a single primer. The amplified products were separated by agarose gel electrophoresis and were detected by staining with ethidium bromide. In 1990, 49 multiresistant A. baumannii strains were isolated from 13 patients from the same intensive care unit of the Charité Hospital; 45 of these outbreak isolates obtained from 12 patients showed the same PCR patterns, indicating an epidemiological relatedness of these strains. Four strains isolated from the same patient belonged to another genetic group, as revealed by a distinct amplification pattern. Another single subtype of A. baumannii was identified as the causative agent in patients during a second outbreak at a different intensive care unit in the same hospital. Seventeen isolates recovered from 10 immunocompromised patients had the same amplification patterns, which were distinct from all other PCR profiles. Five strains were obtained from two other hospitals; three isolates from the hospital of Magdeburg, Germany, had identical PCR patterns which, however, could be clearly distinguished from the patterns of all other strains. The remaining two isolates displayed individual patterns of amplified fragments. PCR fingerprinting may provide a useful and particularly rapid identification technique for epidemiological investigations of nosocomial infections.

Acinetobacter↗
PubMed1989

Neonatal septicaemia--incidence, etiology and outcome. A 6-year analysis.

Between 1983 and 1988 we observed altogether 222 cases of neonatal septicemia and/or meningitis in our Department of Neonatology. The incidence was 8.46 per 1,000 liveborn infants. The case fatality rate amounted to 45.9%. The most frequently isolated causative agents were Escherichia coli (23.4%) followed by group B Streptococci (16.7%), Staphylococcus aureus (9.9%), Klebsiella pneumoniae species (8.8%), Serratia marcescens (7.9%), Pseudomonas aeruginosa and coagulase-negative Staphylococci each 5.9%. The report includes information about serotypes of Escherichia coli, group B Streptococci and plasmid patterns of Serratia marcescens. The latter was responsible for an outbreak of septicemia and meningitis with high mortality. The changing infection pattern reflects changes in the newborn population, especially in the patient structure of the neonatal intensive care unit, changes in the antibiotic policy and organizational problems.

Berlin↗
PubMed1989

[Nosocomial infections caused by multi-resistant Serratia marcescens at a university clinic--clinical aspects and drug resistance].

Serratia marcescens (S.m.) has become increasingly important as a nosocomial pathogen and displayed an increasing resistance to antimicrobial agents in the past decade. We recently studied in 1985 and 1986 an epidemic caused by multi resistant S.m. strains that involved 27 infants and 1 adult patient. 14 neonates (in most cases very low birth weight infants) in a neonatal intensive care unit developed a S.m.-septicemia and/or meningitis, 11 of them died. In a ward for young infants with congenital heart diseases 13 patients suffered a S.m. infection and one patient died in the adult intensive care unit in consequence of a S.m. septicemia.

Anti-Bacterial Agents↗