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Biomedical subjects

S Mayer

Publications and source records attributed to S Mayer.

At least 19 recordsLinked to original sources
PubMed2006

[A new questionnaire for recognizing cognitive problems in children and adolescents].

BACKGROUND: Patients with psychiatric or neurologic disease often suffer from neuropsychologic problems. The purpose of this study was to present a parental questionnaire (KOPKIJ) that assesses neuropsychologic problems in children and adolescents between 6 and 16 years of age. METHODS: We tested theoretical analysis, standardization, and validation of the questionnaire in 352 healthy controls and 116 pediatric patients with epilepsy. RESULTS: The objectivity of this standardized questionnaire can be considered high, and the reliability of the subscales is satisfying. Epileptic patients had higher scores than healthy controls, and the validation displayed reasonable connections with clinical factors and the results of neuropsychological evaluation. CONCLUSION: The KOPKIJ allows an orientating appraisal clear picture of cognitive problems of children and adolescents at home and at school, simplifies anamnesis, and eases the planning of therapy strategies.

Adolescent↗
PubMed2006

[Functional results after intraocular lens implantation with or without blue light filter: an intraindividual comparison].

BACKGROUND: The new generation of intraocular lenses (IOL) with an additional blue light filter has a slight yellowish colour (compared to the IOLs with only a UV filter) due to its different light transmitting properties. This could have an effect on contrast sensitivity and subjective visual perception. PATIENTS AND METHODS: In this intraindividual prospective comparative study including 14 cataract patients without further ocular pathology, a blue light filtering IOL (SN60AT, Alcon) was implanted in one eye and 1 month later a conventional single-piece IOL (SA60AT, Alcon) was fitted into the fellow eye. The visual acuity and the clinical findings were assessed at one day and four weeks post-operatively. Contrast sensitivity was tested under defined mesopic (6 cd/m(2)) and high mesopic (18.8 cd/m(2)) light conditions in the Ginsburg Box using the Functional Acuity Contrast Test (F.A.C.T.). Furthermore, subjective differences in the visual perception of both eyes were noted. RESULTS: The contrast sensitivity testing 1 day and 1 month postoperatively, revealed no statistically significant differences (P > 0.008) between both IOL types for all spatial frequencies (1.5/3/6/12/18 cpd) and light levels. 13 patients (85 %) reported no differences in the colour perception of both eyes, and none had visual disturbances. CONCLUSION: This intraindividual comparison revealed no relevant differences concerning mesopic contrast sensitivity and the subjective visual perception after implantation of one IOL with or without a blue light filter.

Aged↗
PubMed2006

[Esophagobronchial and esophagomediastinal fistula, pleural and pericardial effusion due to severe pseudodiverticulosis of the esophagus].

We describe the case of a patient who came to our hospital with deterioration of his general condition (especially with loss of weight) and progressive thoracic pain with dyspnea. We diagnosed a severe pseudodiverticulosis of the esophagus with esophagobronchial as well as esophagomediastinal fistulae. Furthermore, reactive pleural and pericardial effusions were shown and Candida was detected in a blood culture. By means of antibiotic therapy and esophageal stent implantation, a significant improvement of the clinical signs was achieved. Intramural pseudodiverticulosis of the esophagus is a rare and benign condition. Multiple triggers, for example, obstruction of the ducts due to shedding of epithelial cells, mucus, and/or submucous fibrosis are possible. Clinical signs are progressive dysphagia, caused by an inflamed stenosis of the esophagus.

Anti-Bacterial Agents↗
PubMed2006

Declaration of patent applications as financial interests: a survey of practice among authors of papers on molecular biology in Nature.

OBJECTIVES: To determine whether authors of scientific publications in molecular biology declare patents and other potential financial interests. DESIGN: Survey of a 6-month sample of papers related to molecular biology in Nature. METHODS: The esp@cenet worldwide patent search engine was used to search for patents applied for by the authors of scientific papers in Nature that were related to molecular biology and genetics, between January and June 2005. RESULTS: Of the 79 papers considered, four had declared that certain authors had competing financial interests. Seven papers in which no financial interests were declared had authors with patent applications that were based on the research in the paper or were closely related to it. Another paper had two authors with connections to biotechnology companies that were not disclosed. CONCLUSION: Two thirds of the papers in which authors had patent applications or company affiliations that might be considered to be competing financial interests did not disclose them. Failure to disclose such information may have negative implications on the perception of science in society and on its quality if the possible bias is hidden. Journals should make greater efforts to ensure full disclosure, and scientific institutions should consider failure to disclose financial interests as an example of scientific malpractice. Establishing a register of interests for scientists is one way to increase transparency and openness.

Biotechnology↗
PubMed2006

Sex-specific telomere length profiles and age-dependent erosion dynamics of individual chromosome arms in humans.

During aging, telomeres are gradually shortened, eventually leading to cellular senescence. By T/C-FISH (telomere/centromere-FISH), we investigated human telomere length differences on single chromosome arms of 205 individuals in different age groups and sexes. For all chromosome arms, we found a linear correlation between telomere length and donor age. Generally, males had shorter telomeres and higher attrition rates. Every chromosome arm had its individual age-specific telomere length and erosion pattern, resulting in an unexpected heterogeneity in chromosome-specific regression lines. This differential erosion pattern, however, does not seem to be accidental, since we found a correlation between average telomere length of single chromosome arms in newborns and their annual attrition rate. Apart from the above-mentioned sex-specific discrepancies, chromosome arm-specific telomere lengths were strikingly similar in men and women. This implies a mechanism that arm specifically regulates the telomere length independent of gender, thus leading to interchromosomal telomere variations.

Adolescent↗
PubMed2006

Plasma cell quantification in bone marrow by computer-assisted image analysis.

BACKGROUND: Minor and major criteria for the diagnosis of multiple meloma according to the definition of the WHO classification include different categories of the bone marrow plasma cell count: a shift from the 10-30% group to the > 30% group equals a shift from a minor to a major criterium, while the < 10% group does not contribute to the diagnosis. Plasma cell fraction in the bone marrow is therefore critical for the classification and optimal clinical management of patients with plasma cell dyscrasias. The aim of this study was (i) to establish a digital image analysis system able to quantify bone marrow plasma cells and (ii) to evaluate two quantification techniques in bone marrow trephines i.e. computer-assisted digital image analysis and conventional light-microscopic evaluation. The results were compared regarding inter-observer variation of the obtained results. MATERIAL AND METHODS: Eighty-seven patients, 28 with multiple myeloma, 29 with monoclonal gammopathy of undetermined significance, and 30 with reactive plasmocytosis were included in the study. Plasma cells in H&E- and CD138-stained slides were quantified by two investigators using light-microscopic estimation and computer-assisted digital analysis. The sets of results were correlated with rank correlation coefficients. Patients were categorized according to WHO criteria addressing the plasma cell content of the bone marrow (group 1: 0-10%, group 2: 11-30%, group 3: > 30%), and the results compared by kappa statistics. RESULTS: The degree of agreement in CD138-stained slides was higher for results obtained using the computer-assisted image analysis system compared to light microscopic evaluation (corr.coeff. = 0.782), as was seen in the intra- (corr.coeff. = 0.960) and inter-individual results correlations (corr.coeff. = 0.899). Inter-observer agreement for categorized results (SM/PW: kappa 0.833) was in a high range. CONCLUSIONS: Computer-assisted image analysis demonstrated a higher reproducibility of bone marrow plasma cell quantification. This might be of critical importance for diagnosis, clinical management and prognostics when plasma cell numbers are low, which makes exact quantifications difficult.

Algorithms↗
PubMed2005

[Evaluation of eye patching after cataract surgery in topical anesthesia].

BACKGROUND: Although postoperative eye patching is a common practice its background is not well known. Therefore the necessity of eye patching after cataract surgery in topical anesthesia from the medical point of view and the patients' subjective opinion was studied. PATIENTS AND METHODS: In this prospective and randomized study 133 patients received after cataract surgery either no covering of the eye (group1), a transparent eye shield for four hours (group 2), an eye pad for four hours (group 3) or an eye pad until the next morning (group 4). Clinical findings were noted and local symptoms, such as pain, foreign body sensation, tearing and photophobia were documented on a visual analogue scale (0 - 10). Furthermore, a questionnaire concerning the subjective opinion was handed out to the patient. RESULTS: The clinical findings revealed no significant differences between the groups. The mean values for local pain were 0.94 +/- 1.56, for the foreign body sensation 1.41 +/- 2.02, for tearing 0.99 +/- 1.8 and for photophobia 1.05 +/- 1.99. Comparing the groups there was significantly more pain and foreign body sensation reported by the patients in group 3, who received eye patching for 4 hours. 91 % of the unpatched patients had no discomfort, whereas 53 % of the patients wearing an eye pad until the next morning considered it as unnecessary. CONCLUSION: After cataract surgery in topical anesthesia only mild symptoms were noted. There were no significant differences between the groups in the objective clinical findings and the subjective feeling. These results indicate that after cataract surgery eye patching could be unnecessary.

Adolescent↗
PubMed2005

Benchmark studies of induced radioactivity produced in LHC materials, Part I: Specific activities.

Samples of materials which will be used in the LHC machine for shielding and construction components were irradiated in the stray radiation field of the CERN-EU high-energy reference field facility. After irradiation, the specific activities induced in the various samples were analysed with a high-precision gamma spectrometer at various cooling times, allowing identification of isotopes with a wide range of half-lives. Furthermore, the irradiation experiment was simulated in detail with the FLUKA Monte Carlo code. A comparison of measured and calculated specific activities shows good agreement, supporting the use of FLUKA for estimating the level of induced activity in the LHC.

Benchmarking↗
PubMed2005

Benchmark studies of induced radioactivity produced in LHC materials, Part II: Remanent dose rates.

A new method to estimate remanent dose rates, to be used with the Monte Carlo code FLUKA, was benchmarked against measurements from an experiment that was performed at the CERN-EU high-energy reference field facility. An extensive collection of samples of different materials were placed downstream of, and laterally to, a copper target, intercepting a positively charged mixed hadron beam with a momentum of 120 GeV c(-1). Emphasis was put on the reduction of uncertainties by taking measures such as careful monitoring of the irradiation parameters, using different instruments to measure dose rates, adopting detailed elemental analyses of the irradiated materials and making detailed simulations of the irradiation experiment. The measured and calculated dose rates are in good agreement.

Benchmarking↗
PubMed2004

[Autoimmune cholangitis with vasculitic ulcers, rheumatoid arthritis and IgA glomerulonephritis].

HISTORY AND ADMISSION FINDINGS: A 51-year-old woman was admitted because of relapsing episodes of fever and leg ulcers for 14 years. In addition, she had polyserositis, polyarthralgias and polyarthritides, renal failure with proteinuria and elevation of gamma-GT and alkaline phosphatase. The patient was in a reduced general condition and cachectic nutritional state. She had slight scleral icterus, the liver being palpable 5 cm under the costal margin, edema of the lower limbs and two ulcers at the right foot. INVESTIGATIONS: Laboratory examinations revealed leukocytosis, anemia, elevation of cholestasis and inflammation parameters as well as renal failure. During a 24 hour collection period, a significant proteinuria was demonstrated. Immunoserologically, an ANA titer of 1:100 and a positive rheumatoid factor were found, ANCAs and AMAs were negative. On ultrasound, both kidneys exhibited a blurred pelvic parenchymal border. Thyroid ultrasound demonstrated parenchymal changes consistent with Hashimoto's disease. Ultrasound of the wrist revealed extensive arthritis with tendovaginitis. A renal biopsy revealed mesangioproliferative glomerulonephritis. DIAGNOSIS, THERAPY AND CLINICAL COURSE: Due to serologically persistent cholestasis, a liver biopsy was performed which, together with negative AMAs, revealed the diagnosis of an autoimmune cholangitis (AIC; AMA-negative primary-biliary cirrhosis (PBC)). In addition, the patient presented with rheumatoid arthritis, polyserositis, IgA glomerulonephritis, vasculitic leg ulcers and Hashimoto's thyreoiditis which were interpreted as extra-hepatic manifestations of the AIC. After initiation of high dosage corticosteroid therapy, rapid healing of the leg ulcers occurred. Therapy of the AIC consisted in ursodeoxycholic acid. CONCLUSION: The multitude of associated immunological phenomena in this patient resulted in a delay of the diagnosis. A AIC/PBC, however, should, always be considered in case of cholestasis.

Adrenal Cortex Hormones↗
PubMed2004

Patient communication during cataract surgery.

PURPOSE: Most cataract surgery is now performed under local anaesthesia on a day-case basis. As patients are fully conscious during the procedure, it is important that they remain still. There are a variety of reasons why patients may need to move, and it is important that the surgeon is made aware that this may happen. Some centres offer a nurse's hand as a means of perioperative patient communication. We sought to study the safety and efficacy of using an electronic patient-controlled alert device. METHOD: We compared hand-holding with the use of a patient alert device, and with both communication methods at the same time, on 150 subjects undergoing cataract surgery under local anaesthesia. Assessment of pre- and postoperative state anxiety was undertaken and patients' satisfaction with the communication strategies was assessed. RESULTS: There was a significant difference between pre- and postoperative state anxiety for each group (P<0.001) but no significant differences in pre-, peri-, or postoperative state anxiety between groups. There were no significant differences in confidence, pain, understanding, satisfaction, memory, and reassurance between the three groups. A total of 46% of all patients reported experiencing one or more of the potential problems enquired about, during the operation. Significant correlations were also identified between some of the psychological variables investigated. CONCLUSIONS: An electronic patient alert device is as effective a means of perioperative patient communication as holding a nurse's hand, during cataract surgery under local anaesthesia. It is safe, reassuring and it allows patients to communicate directly with the surgeon.

Aged↗
PubMed2004

Dose equivalent measurements in a strongly pulsed high-energy radiation field.

The stray radiation field outside the shielding of high-energy accelerators comprises neutrons, photons and charged particles with a wide range of energies. Often, accelerators operate by accelerating and ejecting short pulses of particles, creating an analogue, pulsed radiation field. The pulses can be as short as 10 micros with high instantaneous fluence rates and dose rates. Measurements of average dose equivalent (rate) for radiation protection purposes in these fields present a challenge for instrumentation. The performance of three instruments (i.e. a recombination chamber, the Sievert Instrument and a HANDI-TEPC) measuring total dose equivalent is compared in a high-energy reference radiation field (CERF) and a strongly pulsed, high-energy radiation field at the CERN proton synchrotron (PS).

Body Burden↗
PubMed2002

Activity of quinolones against gram-positive cocci: mechanisms of drug action and bacterial resistance.

The quinolones are a potent class of antimicrobial agents that target two essential enzymes of bacterial cells: DNA gyrase and topoisomerase IV. Resistance is mediated chiefly through stepwise mutations in the genes that encode these enzymes, leading to alterations of the target site. These mutations occur in an area called the "quinolone resistance determining region". In gram-positive organisms, mutations occur more often in topoisomerase IV than in DNA gyrase. This target preference appears to depend upon two factors: the species of organism and the selecting drug. Resistance can be enhanced by a decrease in intracellular drug concentration, which is mediated through efflux pumps. The newer generation of fluoroquinolones and non-fluorinated quinolones exhibits enhanced activity against gram-positive organisms compared to the older members of this drug class, although development of resistance to these drugs has been demonstrated in vitro. This review gives a chronological perspective of the literature on the action of DNA gyrase and topoisomerase IV and the mechanisms of resistance to quinolones in staphylococci, streptococci and enterococci.

Anti-Infective Agents↗
PubMed2002

Adventitial stripping of the radial and ulnar arteries in Raynaud's disease.

Adventitial stripping of the palmar arch, the palmar common digital arteries, or the proper digital arteries is a last resort in the treatment of refractory primary or secondary Raynaud's phenomenon. Seven patients who had adventitial stripping of the ulnar and radial arteries proximal to the wrist and resection of the nerve of Henle, if identifiable, are presented. All of them were evaluated by telethermography, acral rheography, and a questionnaire before and after surgery. All were asymptomatic after surgery with satisfactory healing of the ulcers at the fingertips. None of them relapsed during the follow-up time of 1.5 years.

Adult↗
PubMed2002

An evaluation of the administration of sub-Tenon local anaesthesia by a nurse practitioner.

AIM: To evaluate the administration of sub-Tenon local anaesthesia (LA) by a nurse practitioner. METHODS: 106 consecutive patients listed for cataract surgery were given sub-Tenon's anaesthesia by a nurse practitioner. The surgical procedure was performed within 15 minutes of the administration of the LA. Pain, state and adequacy of anaesthesia, appearance of the eye, and patient anxiety were measured. Patients' experiences of this new nursing role were gained through interview. RESULTS: At the beginning of surgery, few patients showed eye movement in any of the four quadrants and the surgeons reported that akinesia was inadequate in only seven (7.1%) cases. Three patients (3.3%) gave a pain score of 3 out of 10 or above during surgery whereas the surgeons assessed the pain relief to be inadequate in eight (8.1%) cases. Five (5.3%) patients required a top up of anaesthesia and 51 (39.8%) patients developed conjunctival chemosis in two or more quadrants. Overall, patients' comments indicate that they were pleased with the new service. CONCLUSION: The results suggest that nurse practitioner delivered sub-Tenon LA is an effective and safe method of LA administration for cataract surgery.

Adult↗
PubMed2001

CNGA3 mutations in hereditary cone photoreceptor disorders.

We recently showed that mutations in the CNGA3 gene encoding the alpha-subunit of the cone photoreceptor cGMP-gated channel cause autosomal recessive complete achromatopsia linked to chromosome 2q11. We now report the results of a first comprehensive screening for CNGA3 mutations in a cohort of 258 additional independent families with hereditary cone photoreceptor disorders. CNGA3 mutations were detected not only in patients with the complete form of achromatopsia but also in incomplete achromats with residual cone photoreceptor function and (rarely) in patients with evidence for severe progressive cone dystrophy. In total, mutations were identified in 53 independent families comprising 38 new CNGA3 mutations, in addition to the 8 mutations reported elsewhere. Apparently, both mutant alleles were identified in 47 families, including 16 families with presumed homozygous mutations and 31 families with two heterozygous mutations. Single heterozygous mutations were identified in six additional families. The majority of all known CNGA3 mutations (39/46) are amino acid substitutions compared with only four stop-codon mutations, two 1-bp insertions and one 3-bp in-frame deletion. The missense mutations mostly affect amino acids conserved among the members of the cyclic nucleotide gated (CNG) channel family and cluster at the cytoplasmic face of transmembrane domains (TM) S1 and S2, in TM S4, and in the cGMP-binding domain. Several mutations were identified recurrently (e.g., R277C, R283W, R436W, and F547L). These four mutations account for 41.8% of all detected mutant CNGA3 alleles. Haplotype analysis suggests that the R436W and F547L mutant alleles have multiple origins, whereas we found evidence that the R283W alleles, which are particularly frequent among patients from Scandinavia and northern Italy, have a common origin.

Amino Acid Sequence↗