Biomedical subjects

A D Forsman

Publications and source records attributed to A D Forsman.

3 recordsLinked to original sources

PubMed1999

Improved soft-agar colony assay in a fluid processing apparatus.

The standard method for quantitating bone marrow precursor cells has been to count the number of colony-forming units that form in semisolid (0.3%) agar. Recently we adapted this assay for use in hardware, the Fluid Processing Apparatus, that is flown in standard payload lockers of the space shuttle. When mouse or rat macrophage colony-forming units were measured with this hardware in ground-based assays, we found significantly more colony growth than that seen in standard plate assays. The improved growth correlates with increased agar thickness but also appears to be due to properties inherent to the Fluid Processing Apparatus. This paper describes an improved method for determining bone marrow macrophage precursor numbers in semisolid agar.

Animals↗

PubMed1999

Effects of space flight and IGF-1 on immune function.

We tested the hypothesis that insulin-like growth factor-1 (IGF-1) would ameliorate space flight-induced effects on the immune system. Twelve male, Sprague-Dawley rats, surgically implanted with mini osmotic pumps, were subjected to space flight for 10 days on STS-77. Six rats received 10 mg/kg/day of IGF-1 and 6 rats received saline. Flight animals had a lymphocytopenia and granulocytosis which were reversed by IGF-1. Flight animals had significantly higher corticosterone levels than ground controls but IGF-1 did not impact this stress hormone. Therefore, the reversed granulocytosis did not correlate with serum corticosterone. Space flight and IGF-1 also combined to induce a monocytopenia that was not evident in ground control animals treated with IGF-1 or in animals subjected to space flight but given physiological saline. There was a significant increase in spleen weights in vivarium animals treated with IGF-1, however, this change did not occur in flight animals. We observed reduced agonist-induced lymph node cell proliferation by cells from flight animals compared to ground controls. The reduced proliferation was not augmented by IGF-1 treatment. There was enhanced secretion of TNF, IL-6 and NO by flight-animal peritoneal macrophages compared to vivarium controls, however, O2(-) secretion was not affected. These data suggest that IGF-1 can ameliorate some of the effects of space flight but that space flight can also impact the normal response to IGF-1. Grant Numbers: NAGW-1197, NAGW-2328.

Animals↗

PubMed1992

Microcorrosion casts of hamster luteal and follicular vasculature throughout the estrous cycle.

Golden hamster (Mesocricetus auratus) ovarian microcorrosion casts were studied as a model system to analyze angiogenesis that occurs in the corpus luteum (CL) during the estrous cycle. Growth of the vasculature in the hamster CL occurs rapidly with complete formation and subsequent degeneration occurring during the 4-day estrous cycle. This study followed the growth of these vessels by casting the ovarian vasculature at 4-hour intervals during the formation of the CL, viewing the casts on a Scanning Electron Microscope (SEM), and comparing the consecutive casts. This study revealed that the microvasculature of the CL forms rapidly from the vessels of the theca folliculi of newly ruptured follicles and that this growth is in an internal direction. This method of casting, when used in conjunction with the high magnification provided by the Hitachi field emission high resolution SEM, enabled us to analyze the growing tips of the vascular sprouts. The vasculature of the CL grows throughout day 1 and well into day 2 of the cycle. Flat veins, characteristic of the external surface of a mature CL, formed by the afternoon of day 2. Obvious degeneration of the vasculature of the CL took place throughout day 3. This study provided a detailed description of the angiogenesis that occurred throughout the rapid formation of the hamster CL and showed that this method produced casts of suitable quality for experimental observations.

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