Oral History - Joe Holt - Vietnam

Oral history on Joe Holt\u27s time in the Marine Corps during the Vietnam War (1965-1969)

Method for the Detection of 17-B-estradiol in Wastewater Facility Effluents Using HPLC

Studies of the effects of estrogen in aquatic ecosystems largely focus on fish. In fish, estrogen reduces fecundity in females, reduces testicular development and fertility in males, and alters vitellogenin production in both sexes. One way estrogens enter aquatic environments is via wastewater effluents. Effluent samples from the Moccasin Bend Wastewater Treatment Facility in Chattanooga, Tennessee were tested for the presence of 17-beta-estradiol (E2), using an Agilent 1260 Infinity LC (HPLC). We were not able to detect the presence of E2 in these samples with the methods described. However, when effluent samples were spiked with stock E2 (final concentration of 0.318 mM), consistent retention times with a corresponding peak were seen. If E2 is present, the absorbable readings could be below the minimum accurate detection limit of our machine (3-2,000 mAU)

Exploring Nursery Growers’ Perceptions, Attitudes and Opinions about Water Usage to Inform Water Conservation Education

Research has shown the nursery industry needs to seek alternative water sources and adopt water conservation strategies to reduce water use in order to stay viable. This study used a qualitative approach to explore nursery growers’ perceptions, attitudes, and opinions about water usage to inform the development of Extension programs that encourage adoption of water conservation strategies. Interviews were conducted with 24 nursery growers across the U.S. The findings indicated growers interact with water in various ways, including meeting plant water needs, facilitating chemical distribution, controlling product quality, and facilitating business operations. The participants felt protecting water was the right thing to do and could provide economic benefits to their business, but water management was perceived as a task enforced by regulations. They reported their future interaction with water would include combatting water issues, engaging in the development and implementation of government regulations, seeking water conservation technologies and information, and dealing with financial challenges. Extension educators should be aware of these needs to alleviate concerns about integrating new processes into business plans. Educational programs should assist in the promotion of water conserving products based on knowledge gaps and provide assistance for easier adoption of new technologies by growers

Lifelong residual bone marrow damage in murine survivors of the hematopoietic acute radiation syndrome (H-ARS): a compilation of studies comprising the Indiana University experience

Accurate analyses of the delayed effects of acute radiation exposure (DEARE) in survivors of the hematopoietic acute radiation syndrome (H-ARS) are hampered by low numbers of mice for examination due to high lethality from the acute syndrome, increased morbidity and mortality in survivors, high cost of husbandry for long-term studies, biological variability, and inconsistencies of models from different laboratories complicating meta-analyses. To address this, a compilation of 38 similar H-ARS studies conducted over a seven-year period in the authors’ laboratory, comprising more than 1,500 irradiated young adult C57BL/6 mice and almost 600 day-30 survivors, was assessed for hematopoietic DEARE at various times up to 30 months of age. Significant loss of long-term repopulating potential of phenotypically-defined primitive hematopoietic stem cells (HSC) was documented in H-ARS survivors, as well as significant decreases in all hematopoietic lineages in peripheral blood, prominent myeloid skew, significantly decreased bone marrow cellularity and numbers of lineage-negative Sca-1+ cKit+ CD150+ cells (KSLCD150+; the phenotype known to be enriched for HSC), and increased cycling of KSLCD150+ cells. Studies interrogating the phenotype of bone marrow cells capable of initiation of suspension cultures and engraftment in competitive transplantation assays documented the phenotype of HSC in H-ARS survivors to be the same as that in non-irradiated age-matched controls. This compilation study adds rigor and validity to our initial findings of persistent hematopoietic dysfunction in H-ARS survivors that arises at the level of the HSC and which affects all classes of hematopoietic cells for the life of the survivor

The H-ARS Dose Response Relationship (DRR): Validation and Variables

Manipulations of lethally-irradiated animals, such as for administration of pharmaceuticals, blood sampling, or other laboratory procedures, have the potential to induce stress effects that may negatively affect morbidity and mortality. To investigate this in a murine model of the hematopoietic acute radiation syndrome, 20 individual survival efficacy studies were grouped based on the severity of the administration (Admn) schedules of their medical countermeasure (MCM) into Admn 1 (no injections), Admn 2 (1-3 injections), or Admn 3 (29 injections or 6-9 oral gavages). Radiation doses ranged from LD30/30 to LD95/30. Thirty-day survival of vehicle controls in each group was used to construct radiation dose lethality response relationship (DRR) probit plots, which were compared statistically to the original DRR from which all LDXX/30 for the studies were obtained. The slope of the Admn 3 probit was found to be significantly steeper (5.190) than that of the original DRR (2.842) or Admn 2 (2.009), which were not significantly different. The LD50/30 for Admn 3 (8.43 Gy) was less than that of the original DRR (8.53 Gy, p < 0.050), whereas the LD50/30 of other groups were similar. Kaplan-Meier survival curves showed significantly worse survival of Admn 3 mice compared to the three other groups (p = 0.007). Taken together, these results show that stressful administration schedules of MCM can negatively impact survival and that dosing regimens should be considered when constructing DRR to use in survival studies

A Potential Role for Excess Tissue Iron in Development of Cardiovascular Delayed Effects of Acute Radiation Exposure

Murine hematopoietic-acute radiation syndrome (H-ARS) survivors of total body radiation (TBI) have a significant loss of heart vessel endothelial cells, along with increased tissue iron, as early as 4 months post-TBI. The goal of the current study was to determine the possible role for excess tissue iron in the loss of coronary artery endothelial cells. Experiments utilized the H-ARS mouse model with gamma radiation exposure of 853 cGy (LD50/30) and time points from 1 to 12 weeks post-TBI. Serum iron was elevated at 1 week post-TBI, peaked at 2 weeks, and returned to non-irradiated control values by 4 weeks post-TBI. A similar trend was seen for transferrin saturation, and both results correlated inversely with red blood cell number. Perls’ Prussian Blue staining used to detect iron deposition in heart tissue sections showed myocardial iron was present as early as 2 weeks following irradiation. Pretreatment of mice with the iron chelator deferiprone decreased tissue iron, but not serum iron, at 2 weeks. Coronary artery endothelial cell density was significantly decreased as early as two weeks vs. non-irradiated controls (P<0.05), and the reduced density persisted to 12 weeks after irradiation. Deferiprone treatment of irradiated mice prevented the decrease in endothelial cell density at 2 and 4 weeks post-TBI compared to irradiated, non-treated mice (P<0.03). Taken together, the results suggest excess tissue iron contributes to endothelial cell loss early following TBI and may be a significant event impacting the development of delayed effects of acute radiation exposure

Cardiac and Renal Delayed Effects of Acute Radiation Exposure: Organ Differences in Vasculopathy, Inflammation, Senescence and Oxidative Balance

We have previously shown significant pathology in the heart and kidney of murine hematopoietic-acute radiation syndrome (H-ARS) survivors of 8.7-9.0 Gy total-body irradiation (TBI). The goal of this study was to determine temporal relationships in the development of vasculopathy and the progression of renal and cardiovascular delayed effects of acute radiation exposure (DEARE) at TBI doses less than 9 Gy and to elucidate the potential roles of senescence, inflammation and oxidative stress. Our results show significant loss of endothelial cells in coronary arteries by 4 months post-TBI (8.53 or 8.72 Gy of gamma radiation). This loss precedes renal dysfunction and interstitial fibrosis and progresses to abnormalities in the arterial media and adventitia and loss of coronary arterioles. Major differences in radiation-induced pathobiology exist between the heart and kidney in terms of vasculopathy progression and also in indices of inflammation, senescence and oxidative imbalance. The results of this work suggest a need for different medical countermeasures for multiple targets in different organs and at various times after acute radiation injury to prevent the progression of DEARE

Aging negatively impacts the ability of megakaryocytes to stimulate osteoblast proliferation and bone mass

Osteoblast number and activity decreases with aging, contributing to the age-associated decline of bone mass, but the mechanisms underlying changes in osteoblast activity are not well understood. Here, we show that the age-associated bone loss critically depends on impairment of the ability of megakaryocytes (MKs) to support osteoblast proliferation. Co-culture of osteoblast precursors with young MKs is known to increase osteoblast proliferation and bone formation. However, co-culture of osteoblast precursors with aged MKs resulted in significantly fewer osteoblasts compared to co-culture with young MKs, and this was associated with the downregulation of transforming growth factor beta. In addition, the ability of MKs to increase bone mass was attenuated during aging as transplantation of GATA1low/low hematopoietic donor cells (which have elevated MKs/MK precursors) from young mice resulted in an increase in bone mass of recipient mice compared to transplantation of young wild-type donor cells, whereas transplantation of GATA1low/low donor cells from old mice failed to enhance bone mass in recipient mice compared to transplantation of old wild-type donor cells. These findings suggest that the preservation or restoration of the MK-mediated induction of osteoblast proliferation during aging may hold the potential to prevent age-associated bone loss and resulting fractures

Delayed Effects of Acute Radiation Exposure in a Murine Model of the H-ARS: Multiple-Organ Injury Consequent to <10 Gy Total Body Irradiation

The threat of radiation exposure from warfare or radiation accidents raises the need for appropriate animal models to study the acute and chronic effects of high dose rate radiation exposure. The goal of this study was to assess the late development of fibrosis in multiple organs (kidney, heart, and lung) in survivors of the C57BL/6 mouse model of the hematopoietic-acute radiation syndrome (H-ARS). Separate groups of mice for histological and functional studies were exposed to a single uniform total body dose between 8.53 and 8.72 Gy of gamma radiation from a Cs radiation source and studied 1-21 mo later. Blood urea nitrogen levels were elevated significantly in the irradiated mice at 9 and 21 mo (from ∼22 to 34 ± 3.8 and 69 ± 6.0 mg dL, p < 0.01 vs. non-irradiated controls) and correlated with glomerosclerosis (29 ± 1.8% vs. 64 ± 9.7% of total glomeruli, p < 0.01 vs. non-irradiated controls). Glomerular tubularization and hypertrophy and tubular atrophy were also observed at 21 mo post-total body irradiation (TBI). An increase in interstitial, perivascular, pericardial and peribronchial fibrosis/collagen deposition was observed from ∼9-21 mo post-TBI in kidney, heart, and lung of irradiated mice relative to age-matched controls. Echocardiography suggested decreased ventricular volumes with a compensatory increase in the left ventricular ejection fraction. The results indicate that significant delayed effects of acute radiation exposure occur in kidney, heart, and lung in survivors of the murine H-ARS TBI model, which mirrors pathology detected in larger species and humans at higher radiation doses focused on specific organs