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Biomedical subjects

L Bodenstein

Publications and source records attributed to L Bodenstein.

6 recordsLinked to original sources
PubMed1994

Cervical lymphadenitis in infants and children.

One of the more common cervical lesions seen in children is cervical lymphadenitis. Pediatricians handle the vast majority of these children who present with an acute infection. The pediatric surgeon becomes involved only when the presumptive infection does not respond to antibiotic therapy, or if the lump becomes chronic and persists for weeks or months. In this situation the specter of malignancy looms, but benign causes still predominate. The infectious agents range from common bacteria such as staphylococci and hematologic staphylococci to atypical mycobacterium, fungi, and other much less common organisms. A broad discussion of the numerous causes of cervical lymphadenitis is presented together with a pragmatic diagnostic and therapeutic approach.

Cat-Scratch Disease↗
PubMed1988

Positional variations in germinal cell growth in pigment-chimeric eyes of Xenopus: posterior half of the developing eye studied in genetic chimerae and in computer simulations.

Growth of germinal cells at different angular positions within the posterior portion of the embryonic frog eye has been examined by orthotopically transplanting small groups of germinal cells from pigmented (stage 30-38) donor embryos into albino (stage 28-36) hosts and then serially photographing the polyclonal-cell progeny domain (typically a black sector) in the pigmented retinal epithelium of the living, growing eye. Far-ventral (6 o'clock) germinal cells formed a narrow sector along the ventral fissure, but ventral germinal cells at a position just posterior to the fissure (7 o'clock on a right eye) were seen to expand rapidly their angular territory on the germinal zone and formed huge sectors that widened toward the front of the older larval eye. Posterior (8, 9, and 10 o'clock) germinal cells were seen to shift their angular positions gradually toward dorsal and formed sectors that appeared to veer dorsalward nearing the front of the older eye. Dorsal (11 o'clock) germinal cells showed attenuative growth, forming sectors that narrowed approaching the front of the older eye. A simulation model of the growth dynamic was used to examine how expansive growth ventrally drives the positional variations in growth. When far-ventral germinal cells were programmed to retain the 6 o'clock position and ventral (7 o'clock) germinal cells were programmed to divide symmetrically at a high probability to produce two daughter germinal cells, not only were the observed ventral chimeric patterns simulated, but also simulated were the attenuative growth of dorsal transplants and the dorsal displacement and veering seen in the growth of posterior transplants.

Animals↗
PubMed1987

Growth and development of the mouse retinal pigment epithelium. I. Cell and tissue morphometrics and topography of mitotic activity.

A computer-assisted morphometric and kinetic analysis of retinal pigment epithelium (PE) development was carried out in C57BL/6J and hybrid mice from Embryonic Day 13 (E13) to Postnatal Day 250 (P250). Total cell number rose from 14,000 at E15 at the rate of about 4000 cells/day to P1 and then at about 1500 cells/day to reach a stable level of 54,000 cells at P15. Compared to the 4-fold rise in cell number, PE area increased about 10-fold, in part through cell hypertrophy which continued beyond P15. Cell concentration increased with distance from the optic nerve head during development, but the gradient disappeared by P20 except for a consistent population of small cells around the optic nerve head and a late-appearing population of very large cells at the ora serrata. Binucleate cells constitute 2.1% of the PE cell population at P1 and 26% at P30, almost all of them located in the posterior 75% of the PE where they comprise 70% of the cell population at some radial positions. Mitotic cells, detected by fluorescent monoclonal antibody R3, are distributed across the entire PE at E13. As the eye grows the mitotic zone occupies a progressively smaller and more distal proportion of the increasing radius; by P5 only the region near the ora serrata is highly active, with some additional mitotic cells trailing into a broad central zone. From P7 to P15 nuclear divisions persist only centrally to generate the youngest uninucleate and binucleate cells. The mouse PE thus shows a pattern of edge-biased interstitial growth (in contrast to amphibians with strict edge growth).

Animals↗
PubMed1987

Growth and development of the mouse retinal pigment epithelium. II. Cell patterning in experimental chimaeras and mosaics.

The retinal pigment epithelium (PE), with pigmentation as a cell-autonomous marker, was analyzed in three types of mice: congenic pigmented----albino chimaeras, X-inactivation mosaics (Cattanach's translocation), and mosaics homozygous for the pink-eyed unstable mutation, which contain rare fully pigmented cells. In 10 chimaeric and 34 X-inactivation eyes, the proportionate mix in the right and left eyes of an individual animal was similar, the mix was approximately constant in all parts of a given eye, average patch size was larger toward the periphery of the PE, and peripheral patches tended to be elongated in the radial dimension. In all 44 whole mounts from pink-eyed unstable mutants, patches of 1-12 pigmented cells, each representing a single clone, were scattered throughout the PE; they tended to be larger with increasing distance from the optic nerve head. The collective data are consistent with significant cell mixing prior to specification of the two eye fields, during early organ-forming stages, and during later development of the PE. The tendency of peripheral patches to orient radially reflects the edge-biased pattern of cell proliferation in the PE. Cell mixing appears to be more prominent posteriorly in the PE sheet; growth proceeds anteriorly for more generations.

Animals↗
PubMed1986

A dynamic simulation model of tissue growth and cell patterning.

The distributions of cells in tissues of experimental chimaeras and mosaics can serve as tests of mechanisms and rules by which single cells organize themselves into complex, multicellular structures during embryogenesis. We have devised a dynamic, computer simulation model of tissue growth and cell patterning which is directly applicable to the analysis of chimaeras and mosaics. In the model, schematized cells possess a small behavioral repertoire and simple rules for the carrying out of these behaviors. Populations of such cells evolve tissue patterns in real-time that are very similar to those seen in experimental animals. In particular, we have modeled the major pattern features seen in amphibian and mammalian eye chimaeras and mosaics. We have demonstrated that cell mixing can be a passive concomitant of interstitial cell division, a result which alleviates the need to postulate active cell mixing in such mammalian systems. We expect this approach to be a valuable addition to methods of pattern analysis in development.

Animals↗