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Biomedical subjects

R Schulte

Publications and source records attributed to R Schulte.

49 records · Page 3Linked to original sources
PubMed1984

Expression of transferrin receptor on murine hematopoietic progenitors.

We have used a monoclonal antibody against the murine transferrin receptor to study the expression of the transferrin receptor on the hematopoietic progenitor cells (BFU-E, CFU-E, and CFU-C) present in mouse bone marrow. Elutriation and cell-sorting data are consistent with the hypothesis that most CFU-E are transferrin receptor positive while most BFU-E express much less transferrin receptor. CFU-C comprise both transferrin-receptor-positive and -negative cells.

Animals↗
PubMed1984

Effect of an anti-murine transferrin receptor-ricin A conjugate on bone marrow stem and progenitor cells treated in vitro.

A monoclonal antibody with specificity for murine transferrin receptor was conjugated with the toxic A subunit of ricin. The dose range, specificity, and kinetics of inhibition of protein synthesis of the conjugate were determined on the murine T-lymphoma cell line, BW5147. When toxin was present throughout the period of culture, in vitro myeloid (CFUc) and erythroid (CFUe and BFUe) bone marrow colonies were inhibited by doses of conjugate comparable to those that inhibit protein synthesis in murine cell lines (IC50 of 5 X 10(-11)M). Bone marrow exposed briefly (30 min to 6 h) to anti-transferrin receptor antibody-ricin A conjugate was assayed for myeloid (CFUc) and erythroid (CFUe and BFUe) progenitors in vitro and for in vivo spleen colony formation (CFUs). Only CFUe were depleted by this pulse exposure, consistent with the higher frequency of proliferating cells and transferrin receptor expression in the CFUe population relative to other progenitors.

Animals↗
PubMed1984

[Fetal echocardiography--possibilities and limits].

Actual possibilities and limitations in fetal echocardiography (two-dimensional and impulse-Doppler technique) based on our own experiences in 53 cases are described. Morphological analysis was almost successful after the 22nd week of gestation, in 11.3% the imaging was inadequate as the result of unfavorable ultrasound viewing. In twins especially the morphological analysis of the second fetus was more difficult. Clear morphological differentiation from the important parts of the fetus heart was possible after the 30th week of gestation in the majority of cases. From 47 sonographically judgeable fetal hearts 3 were classified as malformations. One of them could be confirmed by autopsy (ventricle-septal defect combined with cor monatrium), the second case clinically/echocardiographically postpartally respectively (atrial septal defect - secundum type). On the other hand the third pathological diagnosis of fetal echocardiography (single ventricle) could not be confirmed post-natally. As the result of this preliminary study fetal echocardiography can currently provide some important clues for the selection, perinatological treatment and care in birth of the child with a potentially higher risk factor. Additionally the authors point out the possibilities of complex functional analysis of the fetal heart under different pharmacological treatment.

Diagnosis, Differential↗
PubMed1982

Murine cell surface transferrin receptor: studies with an anti-receptor monoclonal antibody.

A rat monoclonal antibody against the murine transferrin receptor has been identified. The receptor is a 95,000 molecular weight species that exists in the cell membrane as a disulphide-bonded dimer. Whereas 29 of 29 murine hematopoietic tumor cell lines express detectable numbers of transferrin receptors, less than 1% of adult thymocytes or spleen cells and only 5% of bone marrow cells are positive. However, fetal liver and neonatal spleen contain substantial numbers of transferrin receptor-positive cells. Induction of Friend cells in vitro with dimethyl-sulphoxide leads to an overall increase in the expression of transferrin receptors on the cell surface. The anti-transferrin receptor antibody we have obtained partially blocks iron uptake from 59Fe-transferrin by a variety of murine cell lines and inhibits the growth of a murine myeloma cell line in vitro.

Animals↗
PubMed1982

Biochemical characterization and cellular distribution of a polymorphic, murine cell-surface glycoprotein expressed on lymphoid tissues.

A murine leukocyte surface glycoprotein (Mr = 95 000) has been defined by means of xenogeneic monoclonal antibodies. In normal hematopoietic tissues, the glycoprotein is found in highest amounts in the bone marrow. Flow cytometric analysis shows that essentially all bone-marrow cells express the glycoprotein and that it is a major component of a subpopulation of cells containing predominantly granulocytic precursors. In contrast, only about 5 percent of thymocytes express sufficient glycoprotein to be detected by flow cytometric analysis, although under stringent conditions up to 20 percent of thymocytes are susceptible to complement-mediated cytotoxicity using a monoclonal antibody against the glycoprotein. Functional assays showed that both prothymocytes and colony forming unit-spleen express the glycoprotein which is broadly distributed on murine hematopoietic tumor cell lines. However, although some Thy-1+ (T) cell lymphomas express large amounts of the glycoprotein, others do not express detectable quantities of the molecule. The glycoprotein is not restricted to hematopoietic cells and can be detected on lung, kidney, brain, and liver as well as cultured fibroblasts. Monoclonal antibodies against the glycoprotein cross-react with an antigen present on human cells. As described in the accompanying paper, the glycoprotein exists in two antithetical allelic forms and we show that it is identical to a polymorphic surface molecule independently characterized by Colombatti and co-workers.

Animals↗
PubMed1977

Simplified percutaneous lumboperitoneal shunting.

A single unit percutaneous lumboperitoneal shunt has been designed for both diagnostic and therapeutic purposes. Ease of insertion makes this shunt a useful tool in the treatment and diagnosis of communicating hydrocephalus.

Adolescent↗
PubMed1975

The measurement of fetal growth during pregnancy by ultra-sound (B-scan).

We have followed fetal growth by ultrasonographic B-scans. In addition to percentile curves of the biparietal skull diameter we have established percentile curves for measurements of the fetal trunk (sagittal thoracic diameter and length of trunk). The percentile curves for the biparietal diameter were obtained from 5400 individual measurements; the percentile curves for the trunk measurements utilized 1300 individual measurements. These cases were from almost entirely unselected material from our special prenatal clinic. This resulted in a larger variation than the percentile curves for biparietal diameter of other authors [Campbell and Newman]. However, these authors selected their material for "normal pregnancy" while we insured that neither "corrections" of the normal variation nor subjective criteria for exclusion have introduced a systematic error. The advantages of ultrasonography for monitoring of the pregnancy are self-evident: repeated examinations are possible, the examination takes little time, and the method is safe. The determination of the biparietal diameter for estimation of fetal development alone is insufficient because trunk measurements may indicate developmental disturbances (dystrophy and hypertrophy) before the growth of the biparietal diameter of the skull is affected. Furthermore, comparison of the fetal skull and trunk measurement may indicate errors in measurement or malformations (hydrocephalus, microcephalus). The following percentile curves are illustrated graphically: 1. Gestational age versus biparietal diameter (Fig. 1). 2. Biparietal diameter versus weeks of gestation (Fig. 2). 3. Length of gestation versus sagittal thoracic diameter (Fig. 3). 4. Length of gestation versus length of trunk (Fig. 4). 5. Sagittal thoracic diameter versus length of trunk (Fig. 5).

Body Height↗
PubMedDate not supplied

Nonlinear anisotropic diffusion filtering of three-dimensional image data from two-photon microscopy.

Two-photon microscopy in combination with novel fluorescent labeling techniques enables imaging of three-dimensional neuronal morphologies in intact brain tissue. In principle it is now possible to automatically reconstruct the dendritic branching patterns of neurons from 3-D fluorescence image stacks. In practice however, the signal-to-noise ratio can be low, in particular in the case of thin dendrites or axons imaged relatively deep in the tissue. Here we present a nonlinear anisotropic diffusion filter that enhances the signal-to-noise ratio while preserving the original dimensions of the structural elements. The key idea is to use structural information in the raw data-the local moments of inertia-to locally control the strength and direction of diffusion filtering. A cylindrical dendrite, for example, is effectively smoothed only parallel to its longitudinal axis, not perpendicular to it. This is demonstrated for artificial data as well as for in vivo two-photon microscopic data from pyramidal neurons of rat neocortex. In both cases noise is averaged out along the dendrites, leading to bridging of apparent gaps, while dendritic diameters are not affected. The filter is a valuable general tool for smoothing cellular processes and is well suited for preparing data for subsequent image segmentation and neuron reconstruction.

Algorithms↗