Pulmonary biocompatibility assessment of inhaled single-wall and multiwall carbon nanotubes in BALB/c mice

With the widespread application of carbon nanotubes (CNTs) in diverse commercial processes, scientists are now concerned about the potential health risk of occupational exposures. In this study, CNT-induced pulmonary toxicity was investigated by exposing BALB/c mice to aerosolized single-wall (SW) CNT and multiwall (MW) CNT (5 μg/g of mice) for 7 consecutive days in a nose-only exposure system. Microscopic studies showed that inhaled CNTs were homogeneously distributed in the mouse lung. The total number of bronchoalveolar lavage polymorphonuclear leukocytes recovered from the mice exposed to SWCNT and MWCNT (1.2 × 10(6) ± 0.52 and 9.87 × 10(5) ± 1.45; respectively) was significantly greater than control mice (5.46 × 10(5) ± 0.78). Rapid development of pulmonary fibrosis in mice that inhaled CNT was also confirmed by significant increases in the collagen level. The lactate dehydrogenase levels were increased nearly 2- and 2.4-fold in mice that inhaled SWCNT and MWCNT, respectively, as compared with control mice. In addition, exposure of CNTs to mice showed a significant (p < 0.05) reduction of antioxidants (glutathione, superoxide dismutase, and catalase) and induction of oxidants (myloperoxidase, oxidative stress, and lipid peroxidation) compared with control. Apoptosis-related proteins such as caspase-3 and -8 activities were also significantly increased in mice that inhaled CNT than in control mice. Together, this study shows that inhaled CNTs induce inflammation, fibrosis, alteration of oxidant and antioxidant levels, and induction of apoptosis-related proteins in the lung tissues to trigger cell death.

Uranium induces apoptosis in lung epithelial cells

Uranium is a naturally occurring radioactive material present everywhere in the environment. It is toxic because of its chemical or radioactive properties. Uranium enters environment mainly from mines and industry and cause threat to human health by accumulating in lungs as a result of inhalation. In our previous study, we have shown the effectiveness of antioxidant system response to the oxidative stress induced by uranyl acetate (UA) in rat lung epithelial (LE) cells. As part of our continuing studies; here, we investigated the mechanism underlying when LE cells are exposed to different concentration of UA. Oxidative stress may lead to apoptotic signaling pathways. LE cells treated with 0.25, 0.5 and 1 mM of UA results in dose and time-dependent increase in activity of both caspases-3 and -8. Increase in the concentration of cytochrome-c oxidase in cytosol was seen in LE cells treated with 1 mM UA as a result of mitochondria membrane permeability. The cytochrome-c leakage may trigger the apoptotic pathway. TUNEL assay performed in LE cells treated with 1 mM of UA showed significant incorporation of dNTPs in the nucleus after 24 h. In the presence of the caspase inhibitors, we observed the significant decrease in the activity of caspases-8 and -3 in 0.5 and 1 mM UA-treated LE cells.

Proteomic analysis of mouse hypothalamus under simulated microgravity

Exposure to altered microgravity during space travel induces changes in the brain and these are reflected in many of the physical behavior seen in the astronauts. The vulnerability of the brain to microgravity stress has been reviewed and reported. Identifying microgravity-induced changes in the brain proteome may aid in understanding the impact of the microgravity environment on brain function. In our previous study we have reported changes in specific proteins under simulated microgravity in the hippocampus using proteomics approach. In the present study the profiling of the hypothalamus region in the brain was studied as a step towards exploring the effect of microgravity in this region of the brain. Hypothalamus is the critical region in the brain that strictly controls the pituitary gland that in turn is responsible for the secretion of important hormones. Here we report a 2-dimensional gel electrophoretic analysis of the mouse hypothalamus in response to simulated microgravity. Lowered glutathione and differences in abundance expression of seven proteins were detected in the hypothalamus of mice exposed to microgravity. These changes included decreased superoxide dismutase-2 (SOD-2) and increased malate dehydrogenase and peroxiredoxin-6, reflecting reduction of the antioxidant system in the hypothalamus. Taken together the results reported here indicate that oxidative imbalance occurred in the hypothalamus in response to simulated microgravity.

Simulated microgravity activates apoptosis and NF-kappaB in mice testis

Microgravity is known to have significant effect on all aspects of reproductive function in animal models. Recent studies have also shown that microgravity induces changes at the cellular level, including apoptosis. Our effort here was to study the effect of simulated microgravity on caspase-8 and the caspase-3 activities, the effectors of the apoptotic pathway and on the transcription factor NF-kappaB a signaling molecule in mouse testis. Morey-Holton hind limb suspension model was used to simulate microgravity. Caspase-8 and 3 fluorometric assays were carried out and HLS mice testis exhibited a 51% increase in caspase-8 and caspase-3 compared to the controls. A sandwich ELISA-based immunoassay was carried out for detection of NF-kappaB which again significantly increased in the test mice. Testosterone levels were measured using an ELISA kit and in HLS mice the decrease was significant. There was also a significant decrease in testis weight in the test mice. Simulated microgravity activates caspase 8, 3 and NF-kappaB necessary to stimulate the apoptotic pathway in mice testis. This may account for the drop in testis weight and testosterone level further affecting testicular physiology and function.

Genome-wide gene expression profiling of microgravity effect on human liver cells

Human exposure to microgravity is considered the major environmental factor of space flight that affects cells and tissues causing adverse effects to human health. Ground-based gravity-simulation experiments at the cellular and molecular levels have gained some insight into the underlying molecular and cellular alterations induced by microgravity. However, systematic study and detailed molecular mechanisms of the adverse effect of microgravity on living cells are still lacking. The main objective of this study was to apply DNA microarray technology in time-course experiments for genome-wide search of genes whose expression are altered by microgravity, as part of the effort in the identification of major space genes. In this study, we analyzed global gene expression profiles for a human liver cell line exposed to a ground-based modeled microgravity system for 1, 3, and 4 days using the rotary cell culture system (RCCS) and the Agilent 22k human oligo DNA microarrays. We have found that 139 genes' mRNA levels were significantly (P < or = 0.01) altered by the microgravity exposures. Some of these identified genes were further verified by Northern analysis.

Single-walled carbon nanotubes induces oxidative stress in rat lung epithelial cells

Single-walled carbon nanotubes (SWCNT) show unique properties find applications in micro devices; electronics to biological systems specially drug delivery and gene therapy. However the manufacture and extensive use of nanotubes raises concern about its safe use and human health. Very few studies have been carried out on toxicity of carbon nanotubes in experimental animals and humans, thus resulted in limiting their use. The extensive toxicological studies using in vitro and in vivo models are necessary and are required to establish safe manufacturing guidelines and also the use of SWCNT. These studies also help the chemists to prepare derivative of SWCNT with less or no toxicity. The present study was undertaken to determine the toxicity exhibited by SWCNT in rat lung epithelial cells as a model system. Lung epithelial cells (LE cells) were cultured with or without SWCNT and reactive oxygen species (ROS) produced were measured by change in fluorescence using dichloro fluorescein (DCF). The results show increased ROS on exposure to SWCNT in a dose and time dependent manner. The decrease in glutathione content suggested the depletion and loss of protective mechanism against ROS in SWCNT treated cells. Use of rotenone, the inhibitor of mitochondrial function have no effect on ROS levels suggested that mitochondria is not involved in SWCNT induced ROS production. Studies carried out on the effect of SWCNT on superoxide dismutase (SOD-1 and SOD-2) levels in LE cells, indicates that these enzyme levels decreased by 24 hours. The increased ROS induced by SWCNT on LE cells decreased by treating the cells with 1 mM of glutathione, N-Acetyl Cysteine, and Vitamin C. These results further prove that SWCNT induces oxidative stress in LE cells and shows loss of antioxidants.

Proteomic analysis of mice hippocampus in simulated microgravity environment

Space travel induces many deleterious effects on the flight crew due to the '0' g environment. The brain experiences a tremendous fluid shift, which is responsible for many of the detrimental changes in physical behavior seen in astronauts. It therefore indicates that the brain may undergo major changes in its protein levels in a '0' g environment to counteract the stress. Analysis of these global changes in proteins may explain to better understand the functioning of brain in a '0' g condition. Toward such an effort, we have screened proteins in the hippocampus of mice kept in simulated microgravity environment for 7 days and have observed a few changes in major proteins as compared to control mice. Essentially, the results show a major loss of proteins in the hippocampus of mice subjected to simulated microgravity. These changes occur in structural proteins such as tubulin, coupled with the loss of proteins involved in metabolism. This preliminary investigation leads to an understanding of the alteration of proteins in the hippocampus in response to the microgravity environment.

Analysis of stress responsive genes induced by single-walled carbon nanotubes in BJ Foreskin cells

Nanotechnology is finding its use as a potential technology in consumer products, defense, electronics, and medical applications by exploiting the properties of nanomaterials. Single-walled carbon nanotubes are novel forms of these nanomaterials with potential for large applications. However, the toxicity studies on this material are not explored in detail and therefore limiting its use. It has been earlier reported that single-walled carbon nanotubes induces oxidative stress and also dictates activation of specific signaling pathway in keratinocytes. The present study explores the effect of single-walled carbon nanotubes on stress genes in human BJ Foreskin cells. The results show induction of oxidative stress in BJ Foreskin cells by single-walled carbon nanotubes and increase in stress responsive genes. The genes included inducible genes like HMOX1, HMOX2, and Cyp1B1. In addition we validated increase for four genes by SWCNT, namely ATM, CCNC, DNAJB4, and GADD45A by RT-PCR. Moreover results of the altered stress related genes have been discussed and that partially explains some of the toxic responses induced by single-walled carbon nanotubes.

Activation of activator protein-1 in mouse brain regions exposed to simulated microgravity

Microgravity induces stress, and the brain is one of the targets that is more influenced in this environment. Alteration in transcription factors can have enormous effect because of discrepancy in the signaling process of the cells. Activator protein-1 (AP-1) is a stress-regulated transcription factor and is involved in the regulation of physiological and pathological stimuli that include cytokines, growth factors, and stress signals. In the present study, an attempt has been made to observe the effect of a microgravity environment on the activation of AP-1 in the mouse brain. Our results show that AP-1 transcription factor is activated in simulated microgravity conditions in different regions of the brain. The activation of the AP-1 is dependent upon the increased kinase activity of c-Jun NH-terminal2 kinase-1. These results suggest that microgravity stress in the brain can elicit AP-1 activity.

Activation of nuclear transcription factor-kappaB in mouse brain induced by a simulated microgravity environment

Microgravity induces inflammatory responses and modulates immune functions that may increase oxidative stress. Exposure to a microgravity environment induces adverse neurological effects; however, there is little research exploring the etiology of these effects resulting from exposure to such an environment. It is also known that spaceflight is associated with increase in oxidative stress; however, this phenomenon has not been reproduced in land-based simulated microgravity models. In this study, an attempt has been made to show the induction of reactive oxygen species (ROS) in mice brain, using ground-based microgravity simulator. Increased ROS was observed in brain stem and frontal cortex with concomitant decrease in glutathione, on exposing mice to simulated microgravity for 7 d. Oxidative stress-induced activation of nuclear factor-kappaB was observed in all the regions of the brain. Moreover, mitogen-activated protein kinase kinase was phosphorylated equally in all regions of the brain exposed to simulated microgravity. These results suggest that exposure of brain to simulated microgravity can induce expression of certain transcription factors, and these have been earlier argued to be oxidative stress dependent.

Altered cytokine expression in tissues of mice subjected to simulated microgravity

Space flight is known to induce microgravity-associated immune dysfunction in humans, non-human primates and rodents. To understand the mechanism underlying these defects, several studies in rodents have been conducted in a ground-based antiorthostatic suspension (AOS) model that would mimic the effects of microgravity. In all these in vivo studies that showed the effects on cytokine profiles actually investigated the ex vivo production from culturing the cells isolated from whole organism that was exposed to space flight and/or microgravity. So, the purpose of the study was to examine the in vivo expression of cytokines in mice in immunologically important tissue environments of mice that were subjected to AOS. Cytokines such as Interleukin-1beta, (IL-1beta), IL-2, IL-3, IL-6, Interferon-gamma (IFN-gamma) and Tumor Necrosis Factor-alpha (TNF-alpha) were measured by Enzyme Linked Immunosorbent Assay (ELISA) in the homogenates of spleen tissue, lymph nodes and also in serum of AOS mice and compared with that of control mice. AOS induced no change in the IL-3 levels, but IL-1beta was increased significantly whereas IL-2 levels decreased in spleen, lymph nodes and serum. IL-6 levels did not differ in spleen but were significantly increased in lymph nodes and serum of AOS mice. IFN-gamma levels in spleen did not change but showed nonsignificant reduction in lymph nodes and significant reduction in serum in response to AOS. TNF-alpha levels in spleen and serum were unchanged and increased in lymph nodes. This in vivo cytokine study confirms the earlier findings that microgravity-simulated conditions induce tissue-specific immune response.

Measurement of volatile organic compounds in the urban atmosphere of Harris County, Texas, USA

Volatile organic compounds (VOCs) are a major component of urban air pollution. It is well documented that exposure to certain types of VOCs can cause adverse health effects such as cancer, immune and neurological damage, and reproductive and endocrine disorders. Urban air samples were collected at five locations in Harris County, Texas to determine the measurement of VOCs in the ambient air of residential areas in close proximity to industrial facilities that emit toxic air pollutants into the air. Three locations used in this study were located along the Houston Ship Channel (HSC), in the heart of one of the largest petrochemical complexes in the nation. Two other sampling locations were located many miles away from the ship channel and any industrial facilities that are required to report toxic air emissions. Air samples were collected daily over an 8-h period from December 2002 to March 2003. The samples were collected in 6-L stainless steel Silonite-coated canisters and analyzed using a modified version of EPA Method TO-15. A total of 53 compounds was quantitated using a gas chromatograph mass spectrometer system coupled to a cryogenic preconcentrator. Eighteen alkanes and oxygenated compounds were identified, along with 7 alkenes and 5 aromatic compounds. Several alkanes such as butane, isobutane, 2-methyl butane, and pentane were detected at all five sites. The total VOC concentrations determined were highest at two of the industrial sites and lowest at the site farthest away from the ship channel and any industrial facilities. This study concluded that the atmosphere near Harris County's industrial complex had higher concentrations of VOCs than the atmosphere in areas farther away from the HSC. The atmosphere of areas downwind from emission sources were found to be directly affected by toxic air emissions from industrial process but not at the levels seen in areas closer to the HSC.

The relative importance of sexual reproduction versus clonal spread in an aridland bunchgrass

Festuca idahoensis (Idaho fescue) is a perennial caespitose grass, common in semi-arid rangelands of the Intermountain West. To determine how individuals are recruited into a population, we studied two long-term monitoring plots that were established in 1937 at the Northern Great Basin Experimental Range in southeastern Oregon. The plots measured 3.05x3.05 m, and were located approximately 30 m apart. One plot was ungrazed, the other was subject to moderate levels of cattle grazing. The number of F. idahoensis plants in both plots increased ten-fold between 1937 and 1996, but whether this was due primarily to reproduction by seed or clonal fragmentation was unknown. In 1996, we mapped and sampled 160 plants of F. idahoensis. We used dominant inter-simple sequence repeat (ISSR) markers and codominant allozyme markers in order to identify genetic individuals and measure genetic diversity. Both plots were characterized by high levels of genetic and clonal diversity. When information from ISSRs, allozymes and sample location were combined, 126 genets were recognized, each consisting of one to four samples (ramets). By measuring the diameter of clones surrounding plants that were present in 1937, we estimated that clonal spread occurred at a rate of approximately 3.7 cm per decade, and thus was of secondary importance in the maintenance and increase of F. idahoensis stands. Sexual reproduction, rather than clonal fragmentation, accounted for most of the recruitment of new plants into these plots. The grazed plot had fewer ramets, genotypes, and clones than the ungrazed plot, but the ramets were significantly larger. Levels of genetic diversity did not differ in the grazed and ungrazed plots, but there was some evidence for a small, but significant level of genetic differentiation between the two. The results also indicate that F. idahoensis has the potential to be a long-lived species with some individuals persisting in excess of 60 years. This study demonstrates how long-term monitoring can be supplemented by genetic analysis to obtain detailed information on the population dynamics of plants. In the case of this community dominant species, this provides essential information for understanding succession and developing management and restoration strategies.

An environmental assessment of mold concentrations and potential mycotoxin exposures in the greater Southeast Texas area

An assessment of indoor air quality in homes from the greater Houston and Southeast Texas area was sampled over a three-month period to ascertain the potential toxic exposure to molds and mycotoxins. In 2001 Houston experienced widespread flooding due to Tropical Storm Allison. The slow receding waters allowed molds to proliferate to great levels and affected many homes and businesses in and around the Houston area. Source (air) and surface (swab, tape, and bulk) samples were taken in fungal contaminated residences to measure the amounts of airborne and surface contaminants. Indoor airborne counts of fungal spores that were identified to be 80% or more of the outside counts of similar fungal genera were classified as indoor air contaminants. This study identified species of Aspergillus, Penicilliulm, and Cladosporium at levels ranging from 80% to 20 times greater than the corresponding outdoor readings in the greater Southeast Texas area. Aspergillus and Penicillium species are considered potentially toxic to humans at elevated levels due to their ability to produce mycotoxins. Cladosporium is considered nonpathogenic, but can still cause allergenic reactions from hyphal fragments. Surface sampling which is utilized for identification of visible mold contaminants, identified species of Aspergillus. Penicillium, Chaetomium, Cladosporium, and Stachybotrys ranging from 1 to 100 total colony counts (1-100% for tape and bulk noncultured assays) contingent upon the extent of visual contamination. The numerical values from surface sampling were used primarily to identify the degree of visual contamination, as well as, identify any molds that may have been too heavy to become aerosolized.

Vocational rehabilitation outcomes of veterans with substance use disorders in a partial hospitalization program

The authors examined factors that influenced the employment rates of 529 veterans with severe alcohol and other substance use disorders who were being treated at an addictions partial hospitalization program. The employment rate was significantly higher for veterans who completed the hospitalization program, participated in a Veterans Industries work-for-pay program, and received drug-free supportive housing.

Music therapy assessment in school settings: a preliminary investigation

The present investigation was undertaken in response to music therapists working in school settings for information relating to the availability of music therapy assessments and the feasibility of standardizing an assessment instrument for music therapists to use in school settings. Five research questions were identified, and the music therapy literature was surveyed to compile responses to those questions. Three different online data bases (ERIC, PsycINFO, and Article 1st) were used, covering articles published between 1980 and 1997. Individual hand searches were done of the Arts in Psychotherapy, Journal of Music Therapy, Journal of Research in Music Education, Journal of the International Association of Music for the Handicapped, Music Therapy and Music Therapy Perspectives. The questions and responses were as follows: 1. Which music-based assessment tools are being used with children with disabilities? Little commonality in assessment tools being used by music therapists and researchers was discovered. Of the total 41 studies, 20 (49%) reported using a "named" or "titled" assessment tool, and in the remaining 51% of studies, the authors reported using an untitled, and usually experimenter-designed, original assessment tool. 2. Have certain assessments been used in more than one study? Very limited replication of existing assessments was found. Of the 16 "named" assessments, only 3 were found to be used in more than one research study. 3. Are the actual assessments published along with the articles describing their use? Only 3 of the 20 studies using named assessments were published along with the journal article. Of the remaining 21 studies using original, experimenter-designed assessment tools, only 6 (28%) had the assessment instrument published with the article. 4. What is the primary purpose for using the assessment? Six primary purposes emerged from the review of the literature: to compare with data obtained from other assessment measures or from other populations (39%), as a baseline or pretest measure (29%), to determine eligibility for services or the receipt of treatment (12%), to determine the psychometric properties of the assessment (7%), suitability of the instrument for the given population (7%), and the identification of musical preferences (5%). 5. What are the musical or nonmusic elements being assessed? Musical elements were: music perception (37%), musical aptitude (29%), musical preferences (12%), and attention to/enjoyment of music (2%). Nonmusical behaviors/responses were: self-expression (10%), motor responses (10%), behavioral responses (7%), cognitive development (2%), and acts of communication (2%). 6. What subject populations are being assessed? Subject populations were: children with developmental disabilities/mental retardation (44%), children with autism (10%), children with hearing impairments (17%), "psychiatric" clients or emotionally disturbed (22%), individuals described as "handicapped" (5%), individuals with physical disabilities (2%), and a student with a speech impairment (2%). Nondisabled individuals were also included in 12 of the aforementioned studies.

The management of self-inflicted burn injuries and disruptive behavior for patients with borderline personality disorder

One of the greatest behavioral and ethical challenges faced by a burn team is the treatment of a patient whose burn injury is the result of parasuicidal behavior. Parasuicidal behavior is defined as intentional self-injurious behavior that, although not fatal, may result in tissue damage or risk of death. There are a number of reasons, usually psychiatric, that patients engage in parasuicidal behavior; however, our contention is that the majority of these patients have a Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition Axis II diagnosis of borderline personality disorder. We describe the nature of borderline personality disorder and how it leads to disruptive behavior, including self-harm behavior, on the burn unit, We also argue that if staff members fail to recognize the borderline personality disorder diagnosis, it will lead to responses from staff that can heighten disruptive behavior. We present a series of recommendations for treating such patients with burns and an illustrative case report.

Monitoring Wadi El Raiyan lakes of the egyptian desert for inorganic pollutants by ion-selective electrodes, ion chromatography, and inductively coupled plasma spectroscopy

Wadi El Raiyan is a great depression located southwest of Cairo in the western desert of Egypt, one of the most arid regions of the world. In 1973, Wadi El Raiyan was connected with the agricultural wastewater drainage system of the El Faiyum province to provide a reservoir for the wastewater that exceeded the capacity of Lake Qarun north of the province. Pollutants from agricultural waste including pesticides and fertilizers as well as other effluents of industrial activities and runoffs certainly will pass into the biotic elements of the ecosystem. This report presents the status of inorganic pollutants including anions, cations, and trace metals in the two lakes and the surrounding springs of Wadi El Raiyan using ion chromatography, ion-selective electrodes, and inductively coupled plasma emission spectroscopy. The report also includes the levels of selected metals in the vegetation community of the area. The result of this investigation revealed a great improvement in water quality of the Wadi El Raiyan lakes compared to 1988 report by Saleh et al. Mercury was not detected in any of the samples and the level of lead was significantly reduced. Cadmium levels were much higher than those seen earlier. The higher level of cadmium might be used as an indicator to track the contamination of water by human waste. Concentrations of common anions were not significantly different from those reported earlier. However, an increase in the level of cyanide was observed. Levels of heavy metals in vegetation around the lakes were also found to be lower than previously reported.

Analysis of metal pollutants in the Houston Ship Channel by inductively coupled plasma/mass spectrometry

Trace metal pollutants in the surface water of the Houston Ship Channel were determined using inductively coupled plasma/mass spectrometry (ICP/MS). Metal concentrations varied according to sampling sites. Barium, cobalt, chromium, molybdenum, silver, beryllium, antimony, lead, and mercury concentrations were relatively similar throughout the channel averaging 83.25, 0.55, 6. 31, 6.66, 0.02, 0.017, 3.61, 0.68, and 0.055 microg/L, respectively. Titanium, manganese, copper, zinc, nickel, and selenium concentrations were found to be higher at stations closer to the Galveston Bay (as the water is turning from relatively fresh water to sea water) with concentration ranges of 102.5-351.7, 0.3-25, 0. 3-25, 30-280, 16-77, 6.2-26.5, and 0.0-6.2 microg/L, respectively. Aluminum was found to be much higher at the Buffalo Bayou station (341 microg/L) followed by the San Jacinto station (104 microg/L) with an average of 42 microg/L in the other two stations. Vanadium was found to be unusually high at the Washburn Tunnel station (116 microg/L) and at much lower concentrations in the other three stations, averaging 6.5 microg/L. Iron was also higher at the Buffalo Bayou station (143 microg/L) but was absent at the Lynchburg Ferries station. Arsenic was not found at the Lynchburg and San Jacinto stations. However, arsenic had similar concentrations of 1. 983 and 1.835 microg/L at Buffalo Bayou and Washburn Tunnel, respectively. Cadmium was higher at the Lynchburg Ferries station (3. 3 microg/L) and ranged from 0.3 to 0.96 microg/L in the other locations. Thallium was not found in any of the stations.

Cardiodynamic response to psychological and cold pressor stress: further evidence for stimulus response specificity and directional fractionation

In the present study 36 police officers were exposed to a psychological stressor (IQ quiz) and to cold pressor stress while several cardiovascular variables were monitored. Impedance cardiography was used to provide measures of heart rate, stroke volume, cardiac output, myocardial contractility, and total peripheral resistance. In addition, measures of systolic and diastolic blood pressure and peripheral skin temperature were obtained. A multivariate analysis of variance (MANOVA) indicated that significant increases in diastolic and systolic blood pressure during the cold pressor test were mediated by large increases in total peripheral resistance, whereas blood pressure elevation during the IQ quiz were accompanied by significant increases in heart rate and, to a lesser extent, cardiac output. Peripheral skin temperature decreased in response to each stressor. Additional analysis indicated a degree of stimulus specificity for several variables. For example, diastolic blood pressure showed greater increases to cold pressor than quiz, whereas systolic blood pressure increased more with the psychological than the physical stressor. Directional fractionation occurred for both myocardial contractility and cardiac output.

Antihypertensive therapy and quality of life: a comparison of atenolol, captopril, enalapril and propranolol

This randomized, double-blind parallel study compared the effects of atenolol, captopril, enalapril and propranolol in 360 men with mild-to-moderate essential hypertension. Patients were titrated until diastolic blood pressure (Korotkoff phase V) decreased by at least 10 mmHg or to 90 mmHg or less. Quality of life assessments, based on validated psychometric questionnaires and objective measurements of cognitive function, occurred after three study phases: placebo run-in (3-5 weeks), titration (1-4 weeks), and maintenance (4 weeks). After four weeks of maintenance therapy, atenolol, captopril and enalapril generally had equivalent effects on quality of life, as measured by psychometric questionnaires, whereas propranolol consistently evidenced worsening or less improvement. Global scores of distressing psychological symptoms differed as a function of specific treatment (P = 0.01), with improvements significantly better for the atenolol, captopril and enalapril groups as compared with the propranolol group. There were no statistically significant differences among treatments for changes in cognitive function at maintenance. Thus, the quality of life questionnaires differentiated among drugs of the same class, indicating that selection among antihypertensive drugs should be based on their specific qualities, not on general class characteristics.

Characterization of Brucella abortus soluble antigen employed in immunoassay

A soluble antigen extract of Brucella abortus (BASA) has been prepared by the National Veterinary Services Laboratories and furnished to a number of workers who are examining antibody-mediated and cell-mediated immune responses of cattle infected with B. abortus. Three lots of BASA were examined. There were quantitative but not qualitative differences among lots by content of protein, total carbohydrate, hexose, fatty acid, and 2-keto-3-deoxyoctonic acid. The presence of smooth lipopolysaccharide was demonstrated by the presence of 2-keto-3-deoxyoctonic acid and lipid, by Limulus lysate gelation activity, and by formation of characteristic lipopolysaccharide precipitates in immunoelectrophoresis. A polysaccharide antigen as well as two nonsurface antigens, A2 and C, were also identified. BASA is a satisfactory antigen for use in the enzyme-linked immunosorbent assay since the smooth lipopolysaccharide component bound to polystyrene and functioned in the test. Normal murine spleen cells showed a mitogenic response to BASA similar to that produced by purified smooth lipopolysaccharide. BASA has been used in other laboratories to stimulate peripheral blood leukocytes from cattle infected with B. abortus. Because BASA is a mixture of antigenic components shown to have mitogenic effects in the mouse system, questions on the nature of its stimulatory effect on bovine cells are raised.

Regulation of D-xylose and D-arabitol catabolism by Aerobacter aerogenes

Aerobacter aerogenes strain PRL-R3 possesses inducible enzyme pathways for the catabolism of d-xylose and d-arabitol. d-Xylose is the apparent inducer for d-xylose isomerase and d-xylulokinase. d-Arabitol is the apparent inducer for d-arabitol dehydrogenase and a separate d-xylulokinase. Both kinases had similar K(m) values and substrate specificities, and could not be separated by sucrose gradient centrifugation or polyacrylamide gel electrophoresis. They could be differentiated, however, by their separate regulation, their inhibition by antisera, and by the cold sensitivity of the kinase of the d-arabitol catabolic pathway.