PubMed Health⌕ Search

Biomedical subjects

R Wieland

Publications and source records attributed to R Wieland.

9 recordsLinked to original sources

White matter disease in children treated for malignant brain tumors.

OBJECTS: The objects of the study reported were to recognize different patterns of white matter disease (WMD) in the follow-up of children after surgery, radiation and/or chemotherapy for malignant primary brain tumors and to evaluate statistical data on the incidence of WMD and various risk factors. METHODS: Magnetic resonance imaging (MRI) records were evaluated retrospectively in the routine follow-up (range 6 months to 15 years after surgery) of 44 children with malignant primary brain tumors treated with surgery and radiotherapy and/or chemotherapy. RESULTS: WMD was diagnosed in 28 children and subclassified into circumscribed white matter lesions (WML) and diffuse atrophy. WML were the most common finding ( n=13), followed by atrophy ( n=7) and the combination of both ( n=8). Statistical analysis revealed slightly more frequent atrophy in children younger than 5 years. WML could be linked with supratentorial location of the tumor, follow-up longer than 5 years, and the presence of a ventricular shunt. Intrathecal chemotherapy was also a factor, but because of the small sample size of the group this might not be valid. None of the children had neurological deficits attributed to these findings, but the impact on neuropsychological development was not determined.

Adolescent↗

[Overweight and obesity in the Zurich canton. A LuftiBus study].

In this study the data from 30,598 subjects participating in the LuftiBus project during 1993-1998 were analyzed for the prevalence rates of overweight and obesity. 36.6% of men and 23.6% of the women in the total population were overweight (BMI 25.0-29.9 kg/m2) and 6.6% of the men as well as 7.5% of the women were obese (BMI > 30.0 kg/m2). At a younger age the women were in general lighter, however, with advancing age women became heavier than men. The prevalence data from this study are in quite good agreement with data from other Swiss epidemiologic studies as well international studies. The rather high prevalence rates of obesity show clearly that the problem of obesity can only be solved by preventive means.

Adult↗

Proliferation-associated SNF2-like gene (PASG): a SNF2 family member altered in leukemia.

To identify genes involved in cell growth and/or apoptosis in leukemia, differential display was used to identify mRNAs that showed altered expression levels after cytokine withdrawal from the cytokine-dependent MO7e cell line. Sequence analysis of one transcript that showed a profound decrease in expression after cytokine withdrawal revealed it to be a member of the SNF2 family of chromatin remodeling ATPases. This cDNA had a 2514-nucleotide (838-amino acid) open reading frame and encoded an additional 230 amino acids at the NH2 terminus compared with the murine homologue, lsh, and the human counterpart, Hells. This gene locus has been designated SMARCA6 (SWI/SNF2-related, matrix-associated, actin-dependent regulator of chromatin, subfamily A, member 6). The highest levels of mRNA expression in humans are observed in proliferative tissues such as the thymus, testis, and bone marrow. Whereas cytokine withdrawal in MO7e cells leads to apoptosis and decreased mRNA expression, growth arrest without the induction of apoptosis of MO7e cells also leads to down-regulation of mRNA expression, suggesting an association with cell proliferation and not suppression of apoptosis. Nuclear localization of this SNF2-like putative helicase is dependent on a nuclear localization sequence located in the NH2-terminal region. Based on sequence homology to other SNF2-like helicases, the pattern of tissue expression, and the association of expression with cell proliferation, we refer to the protein product as proliferation-associated SNF2-like gene product [PASG (D. W. Lee et al., Blood, 94: 594a, 1999)]. Examination of acute myelogenous leukemia and acute lymphoblastic leukemia samples revealed a high frequency of a PASG transcript containing an in-frame 75-nucleotide deletion, which codes for a conserved motif known to be critical for the transactivation activity of a related yeast SWI/SNF polypeptide. These results extend our knowledge of this SNF2-like family member and suggest a role for PASG in leukemogenesis.

Alternative Splicing↗

[Clinical and experimental evaluation of hydrophilic contact lenses for continuous-wear (author's transl)].

In a clinical and experimental study we tested a new contact lens for continuous-wear. The modified HEMA-lens ("Permalens", Global Vision Ltd, Southampton/GB; Cooper Laboratories, Düsseldorf) has a water content of 74% at pH 7.4. The oxygen transmissibility is, depending on the thickness of the lens, 38--67% of the oxygen in the air. In a first trial we had to eliminate 6 patients due to wrong fitting (much too steep) or dry eyes. After development of a new guide for selection of lens base curves 10 patients with monocular aphakia (10 eyes) and 12 patients with mild myopia (24 eyes) were fitted with the hydrophilic soft contact lens for permanent wear. From a total of 34 eyes in 11 cases (32%) the lenses were removed due to complications (1 conjunctivitis, 1 keratitis, 1 vascularization) or due to lack of cooperation. In 23 cases (68%) the continuous-war lenses were well tolerated without complications for 5 months. In a comparative study in vitro we tested the effect of the contact lens on the viability (swelling rate, intracellular membrane potential of the epithelium) of the isolated human cornea. A damaging effect of the lens on corneal function was not observed. The hydrophilic soft contact lens can be fitted for continuous-wear.

Adult↗

Survey of mortality among employees engaged in the manufacture of styrene and polystyrene at the BASF Ludwigshafen works.

A mortality survey of 1,960 employees currently or previously exposed to styrene at work has shown that the observed number of deaths from cancer or other causes is no higher than the number expected in the German population or in a group of BASF employees. Analyses of deaths occurring after a minimum period of five years in groups exposed for different durations (5 years, 10 years, 15 years, more than 15 years) indicated no increase in mortality with exposure time. This latter observation also applied to malignant tumors; therefore it may be inferred that prolonged exposure to styrene is not a cancer hazard.

Adolescent↗

Enrichment of residual tumor cells in bone marrow or peripheral blood cells in a neuroectodermal tumor model.

To enrich a small population of malignant cells contaminating human bone marrow or peripheral blood, a method of immunomagnetic depletion of the normal nucleated cells was developed. In a model using neuroectodermal cell lines, contaminations between 0.1% and 1.4% of tumor cells could be increased by a factor of 7.5 (median; range, 3.8 to 18.0; n = 10). Because incubation with antibodies is restricted to the magnetic beads in this method, the cell population after removal of the beads has not been incubated with antibodies. The risk of unspecific staining of the tumor cells during the enrichment procedure is minimal. This simple method is therefore well suited to the study of the characteristics of a minimal residual disease population.

Blood Cells↗