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PubMed2003

Provocation studies in the diagnosis of occupational asthma.

Specific and nonspecific provocation studies, although not always essential for diagnosing OA, help confirm the diagnosis and identify the offending agent. Nonspecific bronchial challenge testing is used to detect airway hyperresponsiveness and to clarify the nature of the patient's symptoms. Pharmacologic bronchoconstrictor agents (eg, methacholine, histamine) most commonly are used for the challenge, but nonisotonic aerosols, exercise and hyperventilation also can show airway hyperresponsiveness. Nonspecific challenges usually are done in the laboratory, but can be done at the workplace if emergency equipment is available. A comparison of results obtained at and away from the workplace (at least 1 week apart) may be helpful in diagnosing OA. Specific bronchial challenge testing is considered the gold standard for OA diagnosis. It can be crucial in helping physicians, employers, and employees make decisions about continued employment, compensation, career changes, and treatment. Testing can pinpoint new industrial agents that cause OA, enabling dissemination of information on its hazards to the public and within the industry. The nature of the agent determines the type of protocol that is used for testing. Agents can be in the form of dusts, powders, aerosols, vapors gases, and animal dander. Exposure can be as simple as having patients simulate their work activities, or as complicated as using special challenge chambers with controlled environments and precise delivery of agents. Performing control challenges with a component that is separate from the test agent is essential to avoid false-positive results. The timing, duration, and dosing of exposure depend on the type of reaction that has been experienced previously, the nature of the agent, and the patient's baseline airway hyperresponsiveness. Serial spirometry and observation often are done for up to 8 hours to monitor early and late reactions. SBC testing should be performed in the proper medical setting in which emergency equipment available and should be administered only by healthcare personnel who are trained and experienced in the procedures. Safety of the patient is the primary consideration.

Asthma↗
PubMedDate not supplied

Women living with environmental illness.

We used a case study approach to explore the experiences of 4 women who live with environmental illness (EI). From the unstructured interviews we found a variety of themes that pointed to the complexity of EI and its severe impact on the lives of these women, their families, and their significant others. The methodology was guided by an ecofeminist approach, which enabled a critical analysis of the data to move beyond the personal to the broader sociopolitical forces shaping society. We identified the following themes from the women's stories: indirect exposure to incitants through people with whom these women come in close physical contact; the phenomenon of burden of proof, meaning that these women are forced to explain and legitimize their illness on a continuous basis; taking refuge from a hostile environment in social isolation to a more controlled environment, not as a matter of choice, but because of the severity of the illness; and, finally, a change in value system was integral to the entire process of living with EI.

Environmental Illness↗
PubMed1999

Infection control during construction and renovation in the operating room.

This article describes a case study of reconstruction of an operating room suite. Suggestions for completing the renovations while controlling microorganisms are supplied. A comprehensive Infection Control Program is discussed, which includes essential environment controls in the operating room during any construction and renovation. A policy designed by the authors to minimize surgical infections during reconstruction is shared with the readers.

Air Microbiology↗
PubMed1996

Elevated carbon dioxide influences yield and photosynthetic responses of hydroponically-grown [correction of glown] sweetpotato.

The response of 'TI-155' and 'Georgia Jet' sweetpotato cultivars to elevated CO2 concentrations of 400 (ambient), 750 and 1000 micromoles mol-1 were evaluated under controlled environment conditions using the nutrient film technique (NFT). Growth chamber conditions included photosynthetic photon flux (PPF) of 600 micromoles m-2 s-1, 14/10 light/dark period, and 70% +/- 5% RH. Plants were grown using a modified half-Hoagland nutrient solution with a pH range of 5.5-6.0 and an electrical conductivity of 0.12 S m-1. Gas exchange measurements were made using infrared gas analysis, an open-flow gas exchange system, and a controlled-climate cuvette. Photosynthetic (Pn) measurements were made at CO2 ranges of 50 to 1000 micromoles mol-1. Storage root yield/plant increased with CO2 up to 750 but declined at 1000 micromoles mol-1. Storage root dry matter (DM) and foliage dry weight increased with increasing CO2. Harvest index (HI) for both cultivars was highest at 750 micromoles mol-1. The PPF vs Pn curves were typical for C3 plants with saturation occurring at approximately 600 micromoles m-2 s-1. CO2 concentration did not significantly influence net Pn, transpiration, water-use-efficiency (WUE), and stomatal conductance. As measurement CO2 concentration increased, net Pn and WUE increased while transpiration and stomatal conductance decreased.

Biomass↗
PubMed1996

Development of centrifugal phytotron to study the gravity effect on vegetable plant growth.

The present Spacetron is used to cultivate plants over a long term by controlling environment condition. The cultivation drum was rotated in perpendicular direction creating fluctuation in gravity. Centrifugal force plus 1 G ground gravity, are distributed unevenly over the cultivation drum. This fluctuation effect on plant growth was not clear. In the modified Spacetron the cultivation drum rotates horizontally whereas the plant stage rotated in the perpendicular direction. To find the basic information for design of centrifugal phytotron the two axes Spacetron Junior (clinostat) was developed to formulate the micro and hypergravity environment. It would be used to study the effect on a plant growth process of different gravity conditions. In order to produce the different values of gravity, the clinostat's axis was rotated with a stepping motor at different angular velocity. The axis rotated at 5.2 revolutions per minute (rpm) to create a centrifugal force equivalent to 0.01 G and the plant stage was rotated at 5.2 rpm. The chlorophyll value is higher in the plants under microgravity condition of 0.01 G whereas the fresh weight and dry weight are higher in the plants under control condition of 1 G earth gravity. The result of this study showed that the plant growth was affected by microgravity along with other known factors such as vibration and unknown factors.

Biomass↗
PubMed1979

Nitrogen fixation associated with 'Park' Kentucky bluegrass (Poa pratensis L.).

Associative nitrogen fixation in Kentucky bluegrass (Poa pratensis L.) turfs inoculated with five nitrogen-fixing bacterial isolates was evaluated using the acetylene reduction assay and nitrogen accumulation as indicators of fixation. 'Park' and 'Nugget' Kentucky bluegrass turfs were grown in controlled environment chambers and inoculated with Klebsiella pneumoniae (W-2, W-6, and W-14), Erwinia herbicola (W-8), and Enterobacter cloacae (W-11). 'Park' inoculated with K. pneumoniae (W-6) had significant acetylene reduction activity using undisturbed turfs. Other treatments including turfs treated with heat-killed cells had no significant difference in acetylene reduction. In a second study, "Park' and 'South Dakota Certified' turfs were grown in a greenhouse and inoculated with K. pneumoniae (W-6) and E. herbicola (W-8). 'Park' inoculated with K. pneumoniae (W-6) had increased acetylene reduction activity rates and also a greater nitrogen accumulation in aerial tissues when compared to controls. Acetylene reduction activity was correlated (r = 0.92) to nitrogen accumulation. Other treatments did not effectively increase acetylene reduction activity or nitrogen accumulation.

Acetylene↗
PubMedDate not supplied

Dinitrogen fixation in soybean in response to leaf water stress and seed growth rate.

Late season declines in N2 fixation by soybeans [Glycine max (L.) Merr.] frequently are observed under field conditions but do not always occur under glasshouse and growth chamber culture where water stress is avoided and photoperiod is manipulated to alter rate of seed growth. To evaluate the effects of water stress and photoperiod during reproductive growth declines in N2-fixation, nodulated 'Ransom' soybeans dependent entirely on N2-fixation and growing under controlled environment conditions were divided into two groups at the beginning seed (R5) stage. At R5, photoperiod was utilized to experimentally alter the rate of seed growth as a sink for photosynthate and N by imposing a short-day photoperiod (SD) on half of the plants and a long-day photoperiod (LD) on the other half. Within each photoperiod treatment, half of the plants were subjected to a single episode of leaf water stress between -1.2 and -1.8 MPa at the full seed (R6) stage, and half served as nonstressed controls. Plants were sampled at 1- to 5-day intervals between R5 and full maturity (R8) stages and analyzed for N and total nonstructural carbohydrates (TNC). The rate of N accumulation from N2-fixation declined during reproductive growth for the stressed plants but not for the nonstressed plants. Thus, a water stress can actuate a late season decline in N2-fixation. When rate of seed growth was slowed under LD, N composition in leaves remained higher following water stress than when a faster rate of seed growth was promoted under SD. Dinitrogen-fixation activity and dry matter production recovered after rewatering for stressed plants under LD but not under SD. Concentration of TNC in leaflets was greater under LD for both stressed and nonstressed plants. Thus, concentration of TNC in leaflets does not appear to be as important in recovery from water stress as concentration of N.

Biomass↗
PubMed2004

Soybean (Glycine max) pollen germination characteristics, flower and pollen morphology in response to enhanced ultraviolet-B radiation.

BACKGROUND AND AIMS: Ultraviolet-B (UV-B) radiation effect on reproductive parts of the plants has received little attention. We studied the influence of UV-B radiation on flower and pollen morphology, pollen production and in vitro pollen germination and tube growth of six genotypes of soybean (Glycine max). METHODS: Soybean genotypes were investigated by growing them under four levels of biologically effective UV-B radiation of 0 (control), 5, 10 and 15 kJ m(-2) d(-1) in sunlit controlled-environment chambers. KEY RESULTS: Reductions in lengths of flower, standard petal, and staminal column along with reduced pollen production, germination and tube growth were observed in all genotypes with increasing UV-B radiation. Combined response index (CRI), the sum of percentage relative responses in flower size, pollen production, pollen germination and tube growth due to UV-B radiation varied with UV-B dosage: -67 to -152 with 5 kJ m(-2) d(-1), -90 to -212 with 10 kJ m(-2) d(-1), and -118 to -248 with 15 kJ m(-2) d(-1) of UV-B compared to controls. Genotypes were classified based on the UV-B sensitivity index (USI) calculated as CRI per unit UV-B, where D 90-9216, DG 5630RR and D 88-5320 were classified as tolerant (USI > -7.43), and DP 4933RR, Stalwart III and PI 471938 were sensitive (USI < -7.43) in their response to UV-B radiation. Pollen grains produced in plants grown at 15 kJ m(-2) d(-1) UV-B radiation were shrivelled and lacked apertures compared to control and other UV-B treatments in both sensitive and tolerant genotypes, and the differences were more conspicuous in the sensitive genotype (PI 471938) than in the tolerant genotype (D 90-9216). The number of columellae heads of the exine was reduced with increasing UV-B radiation. CONCLUSIONS: Soybean genotypes varied in their reproductive response to UV-B radiation. The identified UV-B tolerant genotypes could be used in future breeding programmes.

Dose-Response Relationship, Radiation↗
PubMed1998

Towards efficient conversion of electricity into edible biomass in crop production systems: a transgenic approach.

A major problem of controlled environment crop production is the procurement and distribution of adequate light for plant growth. Some electrically efficient light sources lack specific wavelengths required for photomorphogenesis yet provide a light spectrum with a high potential photosynthetic yield. To enable use of these lamps, we describe a concept to genetically modify plants to change their morphogenic responses to light. Photoreceptors in the red and far-red light sensing phytochrome family and the blue light sensing cryptochrome family may be useful to increase or decrease plant sensitivity to regions of the photomorphogenic spectrum. Uses of developmental masterswitches such as COP and DET, and downstream developmental controls, such as the cytokinin biosynthesis enzyme isopentenyl transferase, are also detailed. If photomorphogenic needs can be altered, then lamp selection can be based solely on electrical efficiency of light production and on potential photosynthetic yield from light produced. The combination of lamp electrical efficiency and photosynthetic yield, termed photosynthetic efficacy, was calculated for plant lighting sources. The low-pressure sodium (LPS) and high-pressure sodium (HPS) lamps provide the highest photosynthetic efficacies relative to microwave, metal halide, red and blue light-emitting diodes (LED), and fluorescent lamps. Typically plants grow tall and spindly under LPS or red LED irradiation and in some cases under the broader spectrum of HPS. The strategy of genetic modification of plant light requirements may enable use of electrically efficient and photosynthetically useful red-biased light sources without supplementation from less electrically efficient blue or less photosynthetically useful far-red light sources.

Biomass↗
PubMed2005

Successful desensitization to oxaliplatin.

OBJECTIVE: To report the successful desensitization of a patient to oxaliplatin utilizing an 8-hour desensitization regimen in a controlled environment. CASE SUMMARY: A 53-year-old white woman with metastatic colon cancer was receiving oxaliplatin, bevacizumab, and capecitabine every 2 weeks, with a partial response to therapy. On her fifth cycle of this regimen, she experienced diaphoresis, hypotension, nausea, abdominal cramping, and coryza. According to the Naranjo probability scale, oxaliplatin, and not bevacizumab, was the probable cause of the hypersensitivity reaction. The woman continued therapy with capecitabine and bevacizumab, resulting in stable disease. Due to her initial response to the oxaliplatin-based regimen, it was decided to attempt desensitization to oxaliplatin in a controlled, inpatient environment. An 8-hour desensitization schedule was employed, and the patient successfully completed an additional 3 cycles with full-dose oxaliplatin. DISCUSSION: Hypersensitivity reactions to platinum-containing compounds are well described and potentially life threatening. With expanded use of oxaliplatin in various malignancies, an increased number of hypersensitivity reactions will likely be reported. Patients with previous hypersensitivity reactions to carboplatin are at risk for similar reactions to oxaliplatin. We achieved successful desensitization for oxaliplatin using increased concentrations of the drug over an 8-hour period concomitant with oral and intravenous corticosteroids and histamine blockers. CONCLUSIONS: Hypersensitivity reactions to platinum compounds may result in discontinuation of active therapies in patients with metastatic disease. Desensitization to oxaliplatin is possible utilizing this approach.

Antineoplastic Agents↗
PubMed1994

Long-term cadmium exposure accelerates oxidant injury: significance of bound/free water states during long-term metal stress.

Lepidium sativum (cress) and Lycopersicon esculentum (tomato) plants were grown in peatlite in controlled environments with or without long-term (4 weeks) cadmium stress (Cd) (100 micrograms/ml every fourth day) and with a single exposure (6 hr at 35 parts per hundred million (pphm)) or no exposure to the oxidant ozone (O3). Cress plants which received Cd wilted faster during O3 exposure and became a gray-green color by the end of a 6-hr O3 exposure. Those receiving O3 alone also wilted but were normal in color during wilting. Leaf water content (percentage) significantly declined in both O3 + Cd- and O3-treated plants. However, leaves after Cd + O3 exposure were severely dessicated and necrotic, whereas O3-treated plants recovered their water content completely but had some injury. Increased stomatal aperture in cress but not tomato before O3 exposure and significantly lower water content at 1 and 24 hr after the end of O3 exposure were associated with the higher Cd content of leaves before and subsequent to O3 exposure. These factors contributed to a greater injury and cell death observed in the leaves of combined cadmium-oxidant stress. Dielectric properties of Thlaspi arvense (field penny cress) leaves grown at continuous exposure to Cd and/or nickel (Ni) indicated that there were measurable differences between metal-containing vs control leaves with regard to bound/unbound water status. This indicated that there was more free water under metal stress, and that the bound water content significantly declined in the leaves of these plants.

Cadmium↗
PubMed2001

An assessment of intraocular pressure rise in patients with gas-filled eyes during simulated air flight.

PURPOSE: To investigate the safety of aircraft flight for patients with small volumes of residual postoperative intraocular gas. DESIGN: Nonrandomized comparative trial. PARTICIPANTS: Seventeen eyes (nine gas filled and eight control eyes) of nine patients and one eye of one control subject were tested. METHODS: Patients with postoperative intraocular gas and the control subject were tested in the controlled environment of a hypobaric chamber to simulate the cabin depressurization associated with a typical commercial aircraft flight. Before, during, and after a simulated flight, the intraocular pressure (IOP) in the gas-containing and contralateral eyes was tested using the Perkins (Edinburgh, UK) and Tono-Pen XL (Jacksonville, FL) tonometers. MAIN OUTCOME MEASURES: The absolute and percentage change in IOP with varied cabin pressurization. RESULTS: Of the nine patients with intraocular gas, seven had 10% to 15% gas volume and two had 20% gas volume. In the 10% to 15% gas volume group, the IOP rose by an average of 109% from baseline during ascent to an average cabin altitude of 7429 feet above sea level. The IOP dropped to an average of 30% above baseline IOP during the cruise phase and further decreased to an average of 38% below baseline IOP on return to baseline altitude. In the 20% gas volume group, the IOP rose by an average of 84% from baseline during ascent to an average cabin altitude of 3400 feet above sea level. The IOP dropped to an average of 42% below baseline IOP on return to baseline altitude. The IOP in the contralateral control eyes did not vary with altitude changes. No patient experienced pain or visual loss during the experiments. CONCLUSIONS: Our results demonstrate that IOP may rise significantly in gas-filled eyes during simulated air flight, supporting the current conservative recommendation against air travel for most patients with intraocular gas bubbles. Further testing is warranted to develop a more objective measure of intraocular gas volume estimation and to define better the tolerability of aircraft flight for patients with intraocular gas.

Adult↗
PubMed2006

Safety, tolerability, and efficacy of psilocybin in 9 patients with obsessive-compulsive disorder.

BACKGROUND: Anecdotal reports suggest that psychedelic agents may relieve symptoms of obsessive-compulsive disorder (OCD). This modified double-blind study investigated the safety, tolerability, and clinical effects of psilocybin, a potent 5-HT(1A) and 5-HT(2A/2C) agonist, in patients with OCD. METHOD: Nine subjects with DSM-IV-defined OCD and no other current major psychiatric disorder participated in up to 4 single-dose exposures to psilocybin in doses ranging from sub-hallucinogenic to frankly hallucinogenic. Low (100 microg/kg), medium (200 microg/kg), and high (300 microg/kg) doses were assigned in that order, and a very low dose (25 microg/kg) was inserted randomly and in double-blind fashion at any time after the first dose. Testing days were separated by at least 1 week. Each session was conducted over an 8-hour period in a controlled environment in an outpatient clinic; subjects were then transferred to a psychiatric inpatient unit for overnight observation. The Yale-Brown Obsessive Compulsive Scale (YBOCS) and a visual analog scale measuring overall obsessive-compulsive symptom severity were administered at 0, 4, 8, and 24 hours post-ingestion. The Hallucinogen Rating Scale was administered at 8 hours, and vital signs were recorded at 0, 1, 4, 8, and 24 hours after ingestion. The study was conducted from November 2001 to November 2004. RESULTS: Nine subjects were administered a total of 29 psilocybin doses. One subject experienced transient hypertension without relation to anxiety or somatic symptoms, but no other significant adverse effects were observed. Marked decreases in OCD symptoms of variable degrees were observed in all subjects during 1 or more of the testing sessions (23%-100% decrease in YBOCS score). Repeated-measures analysis of variance for all YBOCS values revealed a significant main effect of time on Wilks lambda (F = 9.86, df = 3,3; p = .046), but no significant effect of dose (F = 2.25, df = 3,3; p = .261) or interaction of time and dose (F = 0.923, df = 9,45; p = .515). Improvement generally lasted past the 24-hour timepoint. CONCLUSIONS: In a controlled clinical environment, psilocybin was safely used in subjects with OCD and was associated with acute reductions in core OCD symptoms in several subjects.

Adult↗
PubMed1973

Control of their environment reduces emotionality in rats.

Rats reared from birth in a "contingent environment" in which they controlled lighting conditions and the delivery of food and water were compared as adults to rats reared in an environment in which they received the same food, water, and lighting conditions, but without control over their occurrence. Rats reared in the contingent environment were less emotional, as judged by activity and defecation scores in open-field testing.

Animals↗
PubMed1990

The work of the South Manchester Accident Rescue Team (SMART).

Skills acquired in the hospital do not necessarily translate to the scene of an accident. However, training in certain hospital specialties, particularly accident and emergency medicine, will expose doctors to dealing with very ill patients in a less rigidly structured environment. The operating theatre is a disciplined and controlled environment. Skill in anaesthesia, monitoring and operating, if tested only in these circumstances may be found to be gravely inadequate when exposed to the fluctuant and hostile environment at the site. Doctors who wish to do this sort of work or are designated to do it, must undergo regular and frequent training, especially if they are not trained in accident and emergency departments. This has long been recognised by the British Association for Immediate Care. In combination with the Royal College of Surgeons of Edinburgh they have now established a diploma in Immediate Medical Care. In urban areas the need for a doctor to attend at the scene of an accident is usually limited to entrapment. These occasions are likely to be infrequent and this can result in a lack of preparedness for such events. Interhospital transfer, primarily from peripheral hospitals to the specialist services of a teaching hospital, often involves critically ill and injured patients. The management of these cases by the mobile team provides regular, frequent exposure to working in a 'hostile' environment. Relationships with the rescue services are developed and staff become familiar with equipment and call-out procedures. The care of transported patients is improved. None of our patients have died in transit or within 6 h of arrival at base.(ABSTRACT TRUNCATED AT 250 WORDS)

Accidents↗
PubMed1989

Novelty-induced place preference behavior in rats: effects of opiate and dopaminergic drugs.

In Experiment 1, adult male rats were given eight 30-min exposures to one of two distinct environments. Control animals received either four exposures to each environment or were not exposed to either environment. When given free-choice access to both environments simultaneously, animals spent significantly more time in the novel environment relative to the familiar environment. In these same animals, horizontal and vertical activity rates were lower in the novel environment than in the familiar environment. In Experiments 2-5, animals were assessed for novelty preference behavior under the influence of either morphine (0, 0.1, 0.3, 1.0 or 3.0 mg/kg), naltrexone (0, 0.1, 0.3 or 1.0 mg/kg), amphetamine (0, 0.1, 0.3 or 1.0 mg/kg) or haloperidol (0, 0.03, 0.1, 0.3 or 1.0 mg/kg). Haloperidol produced a dose-dependent disruption in novelty preference behavior, while all other drugs tested were without effect. Haloperidol also disrupted the novelty-induced decrease in horizontal and vertical activity rates. These results suggest that haloperidol blocks the reinforcing and locomotor-depressant effects of a novel environment in a free-choice preference test.

Amphetamines↗