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A Kiefer

Publications and source records attributed to A Kiefer.

16 recordsLinked to original sources
PubMed2002

[Radiation exposure of health personnel and patients in the heart catheterization laboratory in during vascular brachytherapy].

Interventional radiological measures can lead to high radiation exposures for medical staff. In order to determine the radiation exposure to staff and patients, the resulting radiation exposures were directly measured for 52 measures at an cardiac catheterization laboratory with a new dosimetry system DIS (Direct Ion Storage). Beside the measurement of body dose behind the lead apron, measurements of radiation doses were performed in front of the lead apron and at the wrist of the physician. These measurements were taken as an approximation of the radiation exposure of the non-shielded body parts. The patients dose was estimated by placing a dosemeter close to the head of the patient and from the dose-area product. The mean value of body dose from 52 measurements for the physician behind the lead apron was 1.9 microSv per procedure with a range of 0-9 microSv. In front of the lead apron, a mean value of 53.9 microSv (3-233 microSv) per procedure was obtained. The mean value of partial body dose at the physician's wrist was determined to be 163.2 microSv (12-603 microSv) per procedure. It could be shown that measures combined with interventions lead to higher exposures compared with measures without interventions. For the medical technician, the mean value behind the lead apron was 3.9 microSv (0-58 microSv) per procedure. For the patient, a mean value of 800 microSv (119-8642 microSv) was measured close to the head. The mean dose to the skin of the patient at radiation entrance was determined to be 307 mGy (70-1190 mGy). From this data, the radiation dose per year for the physician performing 1000 measures, was determined to be 1.9 mSv/year. This is below the new dose limit of 20 mSv/year. Also the estimations for the dose to the eye lens and the hands of the physician show no conflicts with actual dose limits when obeying all radiation regulations. The results for vascular brachytherapy did not show significantly higher exposures, compared with conventional measures including interventions.

Adult↗
PubMed2002

Conflicting molecular phylogenies of European long-eared bats (Plecotus) can be explained by cryptic diversity.

Conflicting phylogenetic signals of two data sets that analyse different portions of the same molecule are unexpected and require an explanation. In the present paper we test whether (i) differential evolution of two mitochondrial genes or (ii) cryptic diversity can better explain conflicting results of two recently published molecular phylogenies on the same set of species of long-eared bats (genus Plecotus). We sequenced 1714bp of three mitochondrial regions (16S, ND1, and D-loop) of 35 Plecotus populations from 10 European countries. A likelihood ratio test revealed congruent phylogenetic signals of the three data partitions. Our phylogenetic analyses demonstrated that the existence of a previously undetected Plecotus lineage caused the incongruities of previous studies. This lineage is differentiated on the species level and lives in sympatry with its sister lineage, Plecotus auritus, in Switzerland and Northern Italy. A molecular clock indicates that all European Plecotus species are of mid or late Pliocene origin. Plecotus indet. was previously described as an intergrade between P. auritus and Plecotus austriacus since it shares morphological characters with both. It is currently known from elevations above 800 m a.s.l. in the Alps, the Dinarian Alps and the Pindos mountains in Greece. Since we could demonstrate that incongruities of two molecular analyses simply arose from the mis-identification of one lineage, we conclude that molecular phylogenetic analyses do not free systematists from a thorough inclusion of morphological and ecological data.

Animals↗
PubMed2000

Determination of the cellular retinoic-acid-binding protein in dysplastic epithelia of the cervix uteri, differentiated into apo and holo forms.

PURPOSE: The appearance of the cervical mucosa is regulated by different factors including retinoic acid. Hormone-dependent alteration of the cervix uteri mucosa is accompanied by a decrease or increase of cytoplasmatic retinoic-acid-binding protein (CRABP). To elucidate whether this hormone-dependent alteration of CRABP is preserved in the case of neoplasms of the cervix uteri, we measured the level of total and apo-CRABP in normal and neoplastically transformed cervical cells. METHODS: In a prospective pilot study, standardised biopsies of normal epithelium and cervical intra-epithelial neoplasm grade 3 (CIN III) were taken from 24 patients. A newly developed method was used to determine the intra-epithelial level of apo- and total CRABP. RESULTS: The concentration of total CRABP in normal squamous epithelium compared with that in intra-epithelial neoplasm grade 3 is very significantly lower in the CIN III areas (normal: 3.66 +/- 1.46 pmol/ mg wet weight +/- SD; CIN III 1.43 +/- 0.59 pmol/mg P < 0.01). In addition CRABP in the apo form is lower in normal than in neoplastic epithelium (Wilcoxon test for paired non-parametric values: P < 0.05; mean for all patients: normal: 1.65 + 0.82 pmol/mg; CIN III: 1.14 +/- 0.23 pmol/mg). CONCLUSION: From our results we conclude that, in neoplastically transformed cells, the hormone-dependent CRABP cycle is interrupted. Whether this has consequences for the further development of the neoplastic cells has to be elucidated.

Cervix Uteri↗
PubMed2000

Glomangioma of the nasal cavity and paranasal sinuses.

The glomangioma, a benign vascular tumour, derived from the cutaneous glomus bodies, should not be confused with paragangliomas, which are occasionally also referred to as glomus tumours. Up to now, only eleven cases of a glomangioma of the nasal cavity and the paranasal sinuses have been published. We report the case of a patient with a glomangioma of the ethmoidal aircell system. The tumour was completely removed under endoscopic-microscopic vision via endonasal access. A tumour recurrence was not observed over a period of eighteen months. The clinical signs, diagnosis, therapy and histological features will be discussed with reference to the literature.

Aged↗
PubMed1998

Synergy of the human spine in neutral postures.

The neutral position of the spine is the posture most commonly sustained throughout daily activities. Previous investigations of the spine focused mainly on maximal exertions in various symmetric and asymmetric postures. This report proposes a new synergetic approach for analysis of the spine in neutral postures and evaluates its performance. The model consists of passive components, the osteoligamentous spine, and active components, the spinal muscles. The muscle architecture includes 60 muscles inserting onto both the rib cage and lumbar vertebral bodies. The passive spine is simulated by a finite element model, while kinematic constraints and optimization are used for resolution of a redundant muscle recruitment problem. Although the passive spine alone exhibits little resistance to a vertical load, its load-bearing capacity in neutral posture is significantly enhanced by the muscles, i.e., the passive spine and its muscles must be considered as a synergetic system. The proposed method is used to investigate the response of the spine when the T1 vertebra displaces 40 mm anteriorly and 20 mm posteriorly from its initial position. The sacrum is fixed at all times and the T1 displacements are achieved by the action of muscles. The results suggest that relatively small muscle activations are sufficient to stabilize the spine in neutral posture under the body weight. The results also indicate that muscles attaching onto the rib cage are important for control of the overall spinal posture and maintenance of equilibrium. The muscles inserting onto the lumbar vertebrae are found mainly to enhance the stability of the spine. The proposed method also predicts forces and moments carried by the passive system. Flexion moments ranging from 8000 Nmm to 15,000 Nmm, corresponding to decreases in lordosis of 6 degrees and 7.5 degrees respectively, are found to be carried by the passive spine at the thoracolumbar junction when the T1 vertebra is 40 mm anterior to its initial position.

Finite Element Analysis↗
PubMed1998

[Depression and aggression. A control group study on the aggression hypothesis in depressive disorders based on the Buss-Durkee Questionnaire].

PURPOSE: The aim of this study was to prove the hypothesis that covert or inhibited aggression/hostility as described in psychoanalytic literature is part of the psychogenetic development of depression. METHOD: We compared 50 consecutively admitted depressed inpatients to 50 healthy people of the regionally living general population, matched by sex and age, using the Buss-Durkee Hostility Inventory. RESULTS: Depressed patients have significantly higher values in the BDHI subscales "total aggression", especially in irritability, negativism, resentment, suspicion and guilt, also in "attitudional component", "inhibited aggression" and "covert hostility". No differences were found in "assault" and "indirect aggression", controls got significantly higher values in "verbal aggression". A comparison of depressed patients with suicide attempts versus depressed patients without such behaviour showed no significant differences. CONCLUSION: The psychoanalytic hypothesis seems to be useful for depression but not for the suicidal behaviour of depressive patients.

Adult↗
PubMed1997

Stability of the human spine in neutral postures.

The present study aimed to identify some of the mechanisms affecting spinal compressive load-bearing capacity in neutral postures. Two spinal geometries were employed in the evaluation of the stabilizing mechanisms of the spine in standing neutral postures. Large-displacement finite-element models were used for parametric studies of the effect of load distribution, initial geometry, and pelvic rotation on the compression stability of the spine. The role of muscles in stabilization of the spine was also investigated using a unique muscle model based on kinematic conditions. The model with a realistic load configuration supported the largest compression load. The compressive load-bearing capacity of the passive thoracolumbar spine was found to be significantly enhanced by pelvic rotation and minimal muscular forces. Pelvic rotation and muscle forces were sensitive to the initial positioning of T1 and the spinal curvatures. To sustain the physiological gravity load, the lordotic angle increased as observed in standing postures. These predictions are in good agreement with in vitro and in vivo observations. The load-bearing potential of the ligamentous spine in compression is substantially increased by controlling its deformation modes through minimal exertion of selected muscles and rotation of the pelvis.

Humans↗
PubMed1993

Parasitological and clinical characterization of Simulium neavei-transmitted onchocerciasis in western Uganda.

In the forests of western Uganda onchocerciasis is transmitted by Simulium neavei s.s. Since little is known about the infection transmitted by this vector, a survey was made in 1991 with special regard to adult persons of 15 years and older in the 13 villages of the parish Kigoyera 40 km northeast of Fort Portal. 3268 (52%) of the 6271 registered inhabitants were examined clinically and parasitologically. The highest microfilaria (mf) densities were found on the buttocks, lower ones on the shoulders and the lowest on the ankles. In the parish the standardised prevalence of mf carriers was 62%. The crude prevalences of adult mf carriers ranged from 80% to 95% in the 13 villages. Densities of 100 mf/snip or more were found in 25% of male persons. The community microfilarial load (CMFL) in skin snips from the buttocks was 49 mf/snip, ranging from 22 to 93 in the 13 villages. The standardised prevalence of nodule carriers was 25% and the mean nodule load was 1.9 nodules per nodule carrier. Among 3420 nodules 90% were found on the pelvic girdle. The standardised prevalence of onchocercal dermatitis was 19%. The crude rates ranged within the age groups in males from 20% to 45% and in females from 16% to 41%. The standardised prevalence of persons presenting mf in the anterior chamber of the eye was 24% and the CMFL in the anterior chamber ranged between 1.2 and 3.3 mf/chamber in six villages. Standardised rates were 1.6% for sclerosing keratitis and 0.9% for reduced vision of 3/60 or less. These prevalences of eye lesions are comparable to those observed in West African forest areas. The CMFLs and the prevalences of mf and nodule carriers represent suitable criteria for community diagnosis of S. neavei-transmitted onchocerciasis in Uganda to guide ivermectin treatment, whereas the prevalence of "leopard skin" is not useful. Immigrants living less than five years in the endemic focus should be excluded from the assessment of mf carrier rates and those living there less than ten years from rapid assessment of nodule carrier rates.

Adolescent↗
PubMed1992

Box Hill Hospital Intensive Care Unit.

The Unit Profile of the Intensive Care Unit at Box Hill Hospital describes the Unit's history and the progression it has made through the past 26 years. Details are given on the type of patients received and the catchment areas this Unit services. The organisational structure and the educational services available are discussed. The breakdown of staff including the nursing and medical staff and the available ancillary services as stated. The critical care course is described in detail to give an outline of and to promote this tertiary based course. It is also hoped this will encourage other hospitals and tertiary institutions to structure such similar courses to provide a more professional education for nurses.

Diagnosis-Related Groups↗
PubMed1991

[Not Available].

Explore the source record for details and available documents.

Anthropology↗
PubMed1976

[Investigation of the frequency of heterozygotes for galactose-1-phosphate-uridyl-transferase-deficiency(galactosemia) in the Vienna area. Comparison with the frequency of homozygotes found by newborn screening (author's transl)].

By routine newborn screening for galactose blood level elevations a great difference in the frequency of Galactosemia by transferase deficiency was observed between Eastern- and Western-Austria. This made enzymatic heterozygousity determinations desirable. At the same time it should be examined whether the frequency of homozygotes found by screening correlates with the frequency derived from the heterozygousity frequency. In a first step the region of Vienna was studied. 377 unselected blood samples were examined following BEUTLER-BALUDA's method. As technical control samples of 9 homozygotes and 12 heterozygotes as found by screening were examined but not included in the frequency study. Arranged following age groups a slight but significant decrease of enzym activity with increasing age could be confirmed (23,89 versus 21,99 U/g Hb). This, increasing the overlapping between normals and heterozygotes of different ages possibly should be kept in mind in individual heterzygousity determinations. The enzymatically determined frequency of heterozygotes was found to be twice as high as the frequency calculated from the frequency of biochemically detected but enzymatically proven homozygotes (1:53 versus 1:99). A comparison of the heterozygousity frequencies found in literature with the results of the most efficient (technically most reliable) screening programs shows that this discrepancy is great and general. Bases on heterozygousity frequencies the frequency of homozygotes found by screening programs seems to be at least 50% too low. Analysis of theoretical possibilities for loss of homozygotes by screening programs makes this explanation highly improbable. It seems more probable that the enzymatically determined heterozygotes frequency is too high by including still undefined allels or allel combinations which result in about half normal activity but not in disturbances resembling classical Galactosemia.

Age Factors↗
PubMed1975

Purification of filamentous plant viruses by thin layer centrifugation.

The construction of a modified thin layer ultracentrifuge rotor is described. This rotor was used in the purification of five filamentous plant viruses, viz. TMV, SCMV, PVX, SGV and YMC. The purification and concentration of these viruses in their monomeric forms is hazardous when conventional "tube" rotors are used since they invariably result in dissociation and aggregation of the virus particles. Using the thin layer rotor these infective agents may be concentrated in volumes of fluid equal to approximately 1% of the starting suspension and not as pellets obtained after ultracentrifugation is conventional "tube" rotors. Electron microscopy revealed that the virus particles concentrated by thin layer centrifugation were not aggregated and that only few fragments of the virus filaments were present in the final preparations.

Plant Viruses↗
PubMedDate not supplied

[Quantitative determination of alpha-peroxyachifolide in yarrow by HPLC with amperometric detection].

A HPLC method with amperometric detection is established for the contact allergen alpha-peroxyachifolid (1) from yarrow (Achillea millefolium L., s. str.). The amounts of 1 are between 0.25 and 0.60% in blossoms, dried 2 h at room temperature, and between 0.01 and 0.05% in the leaves. In completely dried material and in some preparations from the market 1 could also be quantified.

Allergens↗