Search PubMed⌕ Search

Biomedical subjects

R E Gold

Publications and source records attributed to R E Gold.

At least 19 recordsLinked to original sources
PubMed1998

A preliminary study of immunologic and hematologic profiles of peripheral blood from Nebraska farmers who apply pesticides to their fields.

OBJECTIVE: Laboratory studies have documented a wide range of pesticide-induced changes in the hematopoietic and lymphoreticular systems. Some of these are expressed as altered serum values, blood cell counts, and leucocyte functions. The goal of the present study was to determine whether these alterations were evident in peripheral blood of Nebraska farmers who applied pesticides to their fields. METHODS: An invitation to participate was mailed to 100 residents (70 farmers; 30 controls) of Butler County, Nebraska. All respondents (51 farmers and 21 controls) were enrolled and surveyed by written questionnaire for health status and pesticide use. Our analysis included 45 farmers and 18 controls. The farmers were divided into a high (n = 23) and a low (n = 22) pesticide use group. Statistical correlations of ten blood values with both pesticide use and age were evaluated, since pesticide use correlated with age. RESULTS: Four of the ten blood values correlated with pesticide use and age (Spearman Rho). In a multiple regression model, pesticide use (not age) proved to be a predictor of red blood cell count and hematocrit. In the same model, pesticide use was not a predictor of mean red cell volume or candida antigen-induced T-lymphocyte proliferation. Serum complement activity did not correlate with pesticide use among the farmers (n = 45) but was significantly reduced (ANOVA) in the high pesticide use group, compared to controls. CONCLUSIONS: A preliminary study of blood values in a small cohort of Nebraska farmers found no pesticide-associated effects on 1) leucocyte count, 2) antigen- and mitogen-stimulated T-cell proliferation, 3) mitogen-stimulated B-cell proliferation, and 4) concentrations of serum IgG and IgM. The study found small but statistically significant pesticide-associated effects on red blood cells and serum complement.

Adult↗
PubMed1997

Predicting clinical outcome of nonsurgical management of blunt splenic injury: using CT to reveal abnormalities of splenic vasculature.

OBJECTIVE: Using CT to grade blunt splenic injuries frequently does not predict clinical outcome. This retrospective, blinded study evaluated whether revealing a traumatic pseudoaneurysm or frank hemorrhage on an initial CT examination can be used to predict the successful clinical outcome of patients managed without surgery. MATERIALS AND METHODS: The medical and CT records of all patients with blunt splenic injury during a 5-year period were independently reviewed for vascular abnormalities. Also, the grade of injury was reconfirmed. Hemodynamically stable patients with injuries of grades 1-3 were managed without surgery. Clinical failure occurred if a patient required splenectomy or splenorrhaphy after any attempt of nonsurgical management. RESULTS: Two hundred sixty-three patients were treated for blunt splenic injuries. Eighty-two of these patients underwent emergent surgery on the basis of clinical and peritoneal lavage findings without CT examination. The remaining 181 (69%) patients were initially evaluated with emergent abdominal CT. Of these 181 patients, 72 (40% of those undergoing CT) were treated nonsurgically. Nonsurgical therapy failed in 11 (15%) of these 72 patients. Of these 11 patients, nine (82%) had a defined vascular abnormality of the spleen. Only eight (13%) of the remaining 61 patients who underwent CT and successful nonsurgical management had a vascular abnormality of the spleen. CONCLUSION: The failure rate in patients with nonsurgically managed blunt splenic injuries may be markedly reduced if patients with traumatic pseudoaneurysm or active hemorrhage revealed on emergent CT are treated with early surgical or endovascular repair.

Adult↗
PubMed1996

CT aortography of thoracic aortic rupture.

OBJECTIVE: Emergent aortography is commonly used to confirm and define a suspected thoracic aortic rupture detected by CT screening. We evaluated whether helical CT aortography can replace transcatheter aortography for critically injured patients. SUBJECTS AND METHODS: Over 22 months, 38 thoracic aorta and great vessel injuries were detected in 3229 patients with nontrivial blunt chest trauma who underwent helical CT screening. Planar, oblique, and curved two-dimensional reconstructions and three-dimensional shaded-surface display and maximum intensity projection volume-rendering techniques were used to evaluate the aortic injuries. Transcatheter aortography or surgery was performed in all stable patients. RESULTS: Twenty-eight of the injuries involved the descending thoracic aorta. All such injuries were best identified on axial images before CT angiography. CT angiography adequately showed tears over 15 mm long. Smaller tears required axial images for corroboration. CONCLUSION: Technically adequate axial helical CT detects and defines all injuries of the thoracic aorta. CT angiography supplements the conventional examination and can replace transcatheter aortography except for small tears or indeterminate studies.

Adolescent↗
PubMed1995

Over the southern solar pole: low-energy interplanetary charged particles.

The heliosphere instrument for spectrum, composition, and anisotropy (HISCALE) recorded the fluxes of low-energy ions and electrons (> 50 kiloelectron volts) when Ulysses crossed the southern solar polar region and revealed that the large-scale structure of the heliosphere to at least approximately -75 degrees was significantly influenced by the near-equatorial heliospheric current sheet. Electrons in particular were accelerated by the current sheet-produced and poleward-propagating interplanetary reverse shock at helioradii far from the Ulysses location. At heliolatitudes higher than approximately -75 degrees on the Ulysses ascent to the pole and approximately -50 degrees on the descent, small, less regular enhancements of the lowest energy electron fluxes were measured whose relations to the current sheet were less clear. The anomalous component of low-energy (approximately 2 to 5 megaelectron volts per nucleon) oxygen flux at the highest heliolatitudes was found to be approximately 10(-8) [per square centimeter per second per steradian (per kiloelectronvolt per nucleon)]; the anomalous Ne/O ratio was approximately 0.25.

Electrons↗
PubMed1995

Blunt traumatic aortic rupture: detection with helical CT of the chest.

PURPOSE: To determine the effectiveness of helical computed tomography (CT) as a screening device to detect traumatic aortic rupture. MATERIALS AND METHODS: Helical CT was used to examine 1,518 patients with nontrivial blunt trauma. Of these patients, 127 (8.37%) with abnormal CT scans of the mediastinum or aorta underwent thoracic aortography--89 patients solely for evaluation of mediastinal hematoma depicted at CT. Imaging abnormalities were correlated with surgical or clinical outcome. RESULTS: Twenty-one aortic injuries were identified that ranged from subtle intimal flaps to complete aortic disruption. Helical CT was more sensitive than aortography (100% versus 94.4%, respectively) but less specific (81.7% versus 96.3%, respectively) in detection of aortic injuries in patients who underwent both examinations. The association between CT findings and outcome was phi = 0.62 (chi2 = 49.1, 1 df, P < .01) and between aortography and outcome was phi = 0.85 (chi2 = 92.2, 1 df, P < .001). The P value of the difference between the phi coefficients was .10. CONCLUSION: Helical CT of the chest is effective for screening critically injured patients with possible blunt thoracic aortic injuries.

Adolescent↗
PubMed1993

Distribution and seasonal and diurnal activity patterns of Eutrombicula alfreddugesi (Acari: Trombiculidae) in a forest edge ecosystem.

Microclimatic and vegetative effects on the population size and activity patterns of larval Eutrombicula alfreddugesi Oudemans, 1910 (Acari: Trombiculidae), were investigated in Nebraska between latitude 40 degrees 0'0" N and 40 degrees 1'21" N. Larval population densities along a forest edge were greatest in areas of high relative humidity, moderate temperature, low incident sunlight, and increasing substrate vegetation. Although chigger populations existed throughout the forest edge, larger populations concentrated in short- to tall-grass transition zones. Chiggers were rarely found in the undergrowth beneath the tree canopy. Chigger activity correlated with a microclimatically driven diurnal rhythm. Activity was greatest during the late afternoon-early evening, between 1530 and 1930 hours (CDST). Larval activity dropped to low levels and remained so until sunrise; this period of reduced activity occurred between 1930 and 0530 hours. Small increases in larval activity occurred around sunrise (approximately 0600-0700 hours). Between about 0700 and 1530 hours, larval E. alfreddugesi were inactive and did not respond to normal sampling stimuli. Larval populations appeared in late April through early May, peaked in abundance in late June and early July, diminished through late summer, and disappeared in midautumn as the ground began to freeze.

Animals↗
PubMed1992

Exposure of applicators and residents to chlordane and heptachlor when used for subterranean termite control.

Research was conducted to assess dermal and respiratory exposure to applicators from chlordane and heptachlor used for subterranean termite control and exposure to residents of treated homes. Dermal exposure of 29 applicators was evaluated by using gauze pads attached to outer and inner clothing at selected body regions. Respiratory exposure of applicators was monitored with personnel-type air samplers worn during application periods. Air samplers were equipped with polyurethane foam plugs to trap airborne chlordane and heptachlor. Exposure of residents was measured by sampling ambient air of 19 homes treated with the termiticides. Electric air samplers equipped with foam plugs were used to monitor ambient air from the basement, the kitchen, and one bedroom at: 24 h prior to termiticide application, during application, and post-application at 24 h, 1 wk, and monthly for 6 mo. Applicator dermal exposure was estimated based on exposure rates to each body region. Respiratory exposure was estimated based on termiticide concentrations in the air and on the ventilation rate of a person doing light work. Residents' exposure was estimated based on the amount of termiticide present in ambient air. Results indicated that applicator exposure rates to chlordane and heptachlor were 2.54 and 1.88 micrograms/kg/h, respectively. Residents were exposed to less than 0.69 and 2.86 micrograms/m3 of chlordane and heptachlor, respectively. During this research, the application of termiticide containing chlordane and heptachlor posed minimal risk in terms of acute exposure to either the applicators or the residents of the treated homes.

Air Pollution, Indoor↗
PubMed1992

Inhibition of interleukin-2-stimulated enhancement of human natural killer (NK) cell activity by carbaryl, an anticholinesterase insecticide.

The potency of the anticholinesterase (antiCHE) insecticides as serine hydrolase inhibitors, and evidence for serine hydrolase activity in interleukin-2 (IL2) signalling suggest that the natural killer (NK) cell may be a target for dysregulation by antiCHE insecticides. NK cells are large granular lymphocytes (LGL) that respond to IL2 by proliferating and increasing their cytolytic efficiency. In the present study, we assessed the effects of carbaryl (CA, an antiCHE insecticide) and alpha-naphthol (NA, the major metabolite of CA) on both target cell killing per se and IL2 enhancement of target cell killing by human NK cells. Human LGL, collected from the peripheral blood of normal donors, were cultured for 4 days with human recombinant IL2 (HRIL2), then assayed by a 51Chromium (51Cr) release assay for lytic activity against human K562 cells. When added at the beginning of the culture period, CA inhibited enhancement of cytolytic efficiency in a concentration-dependent manner; at concentrations (0.5 and 5.0 microM) compatible with no cholinergic toxicity. Reduction of the effector/target cell (E/T) ratio in the 51Cr release assay markedly enhanced the observed inhibition by CA. In one experiment, inhibition increased from 6% to 20%, 17% to 35%, and 53% to 73% at 0.5, 5.0, and 50 microM CA, respectively, when E/T was reduced from 10:1 to 2.5:1. This result is consistent with reduced cytolytic efficiency of individual NK cells exposed to CA. NA had no effect at 0.5 or 5.0 microM but caused some inhibition at 50 microM. Neither CA nor NA produced LGL death. When CA or NA was added directly to the 51Cr release assay, inhibition was not observed. The mechanism of inhibition of IL2-stimulated enhancement of target cell killing is not yet known, however, the results are consistent with impairment of IL2 signalling, by CA.

Adult↗
PubMed1992

Preoperative embolization of the spleen in children with hypersplenism.

Splenomegaly associated with myelodysplastic disorders in children may be massive and can result in pancytopenia, abdominal discomfort, and respiratory distress. When these symptoms cannot be relieved by nonsurgical means, splenectomy may be indicated. Under such conditions, surgical splenectomy carries increased risks, as the thrombocytopenia is difficult to correct secondary to splenic sequestration. Additionally, the surgical anatomy is often distorted secondary to the massive spleen and dissection can be difficult. These factors can lead to uncontrollable hemorrhage. In an attempt to decrease intraoperative blood loss, the authors successfully performed preoperative splenic artery embolization in 11 of 12 children (age range, 1-11 years) with pancytopenia due to hypersplenism. Hypersplenism requiring surgical splenectomy was due to leukemia (n = 9), myelodysplastic syndrome (n = 1), immune thrombocytopenia (n = 1), and osteopetrosis (n = 1). Embolization was performed under general anesthesia, prior to surgery, with gelatin sponge particles alone, Gianturco coils alone, or a combination of polyvinyl alcohol sponge particles and Gianturco coils. Embolization allowed for safe surgical splenectomy.

Child↗
PubMed1992

Bite-count evaluation of the repellency of N,N-diethyl-3-methylbenzamide to larval Eutrombicula alfreddugesi (Acari: Trombiculidae).

Larvae of the pest chigger mite Eutrombicula alfreddugesi Oudemans, 1910, exhibited a low repellent threshold for N,N-diethyl-3-methylbenzamide (deet) in a field setting. Use of a deet-based repellent significantly reduced chigger mite infestation. Efficacy of aerosol formulations was significantly diminished with 9% (AI) deet. E. alfreddugesi utilized both direct and indirect paths to infest the human body. Direct infestation led to the highest body region bite counts. Distribution of E. alfreddugesi bites over 15 regions of the human body fell into three zones of decreasing parasitism: the ankle/calf region (accessed through direct infestation); the groin, chest, back, armpits, and feet (accessed through indirect infestation); and the thighs, arms, buttocks, head, and neck, which were infrequently attacked or were unavailable to E. alfreddugesi.

Animals↗
PubMed1991

Modulation of interleukin-2-driven proliferation of human large granular lymphocytes by carbaryl, an anticholinesterase insecticide.

Studies in other laboratories have provided evidence that the interleukin-2 (IL2) signaling pathway in lymphocytes includes essential, serine proteases. Since the anticholinesterase (antiCHE) insecticides are potent serine hydrolase (esterase and protease) inhibitors, we assessed the ability of carbaryl (CA, a widely used antiCHE insecticide) and alpha-naphthol (NA, a major metabolite of carbaryl) to modulate IL2-driven proliferation of large granular lymphocytes (LGL) purified from human peripheral blood. These cells express nearly all of the natural killer (NK) activity of human peripheral blood. NK cells are normal lymphocytes that respond to IL2 by proliferating and increasing their tumoricidal activity on a per cell basis. Cultures of purified LGL, initiated in the presence of human recombinant IL2, were harvested on culture Day 4, then proliferation was measured as [3H]thymidine incorporation. When added only at the time cultures were initiated. CA inhibited incorporation 10-32%, 35-53%, and 54-57% at 0.5, 5.0, and 50 microM, respectively. In contrast, NA had no effect at 0.5 and 5.0 microM, but was inhibitory (16-17%) at 50 microM. Reexposure to CA or NA, during the incorporation assay, had little effect on the observed inhibition profiles. Chemically induced changes in cell number during an 8-day culture period reflect the chemically induced changes in [3H]thymidine incorporation. Neither CA nor NA produced cell death. Quantitation of both CA and NA by HPLC indicated a rapid loss of CA (ca. 95% in 24 hr) and a much slower loss of NA from the culture medium. CA inhibited human LGL proliferation at concentrations producing little or no inhibition of serum CHE, an indicator of exposure to antiCHE insecticides.

Adult↗
PubMed1991

Polysplenia syndrome in the asymptomatic adult: computed tomography evaluation.

Although the majority of patients with polysplenia syndrome will present during infancy or childhood with congenital heart disease, 5% to 10% will have no cardiac disease; and the associated abnormalities may not be discovered until adulthood. Physicians should be familiar with the chest and abdominal radiographic findings so as not to confuse this syndrome with other, more common pathologic conditions in asymptomatic adult patients.

Azygos Vein↗