Formoterol and isoproterenol induce c-fos gene expression in osteoblast-like cells by activating beta2-adrenergic receptors

Formoterol, a beta2-adrenergic agonist has been shown in ovariectomized rat models to have anabolic effects on bone. However, those studies did not determine whether the effect of formoterol was by a direct action on bone cells themselves or indirectly via anabolic action on muscle. To address the question of whether formoterol could directly affect osteoblast function we investigated the expression patterns of beta3-adrenergic receptors (betaARs) in human osteoblast-like cells and functional coupling to gene expression. Northern blot analysis showed that betaAR subtypes are expressed at different levels in the osteoblast-like cell lines TE-85, SaOS-2, MG-63, and OHS-4. beta1AR expression was found in SaOS-2, OHS-4, and TE-85, but not MG-63 cells. beta2ARs are expressed at higher levels in MG-63 cells than in TE-85 and SaOS-2 cells, but were not detected in OHS-4 cells. PCR analysis paralleled the northern blot analysis except that beta3AR expression was found in one of three human primary osteoblast cDNAs tested. beta3AR expression was not found in any of the osteoblast-like cell lines. The nonspecific betaAR agonist, isoproterenol, and the beta2AR-specific agonist, formoterol, induced c-fos gene expression in cultured SaOS-2 cells in an immediate early fashion. This effect was inhibited by the beta2AR-specific antagonist, ICI 118551, but not by the beta1AR-specific antagonist, CGP 20712, indicating that induction of c-fos gene expression is specifically mediated by beta2ARs. c-fos gene expression was induced by both isoproterenol and formoterol via increases in cAMP, which in turn activated the cAMP/PKA pathway; the PKA inhibitor, H89, inhibited c-fos gene expression. Thus, betaARs are expressed in osteoblast-like cells and are coupled to c-fos gene expression via the beta2AR, increases in cAMP levels and activation of a PKA-dependent pathway.

The hypothalamo-pituitary-adrenal axis of athymic Swiss nude mice. The implications of T lymphocytes in the ACTH release from immune cells

Because of the well-known role of the thymus in the regulation of immune function, we investigated whether the lack of thymus may affect hypothalamo-pituitary-adrenal (HPA) axis activity. Eight-week-old female Swiss nude (athymic) and BALB/c (normal) mice were used to study (a) the "in vivo" response of the HPA axis to various stresses and stimuli acting at either hypothalamic, pituitary, or adrenal levels and (b) the "in vitro" response of pituitary and adrenal cells to CRH and ACTH stimulation, respectively. The results indicate that (1) basal plasma ACTH levels were significantly (p < 0.05) higher in Swiss nude than in BALB/c mice, whereas basal corticosterone (B) levels were similar in both strains of mice; (2) the stress-induced release of ACTH and B in plasma was significantly (p < 0.05) lower in Swiss nude than in BALB/c mice, regardless of the stimulus applied; (3) the "in vitro" pituitary response to CRH and the adrenal response to ACTH were significantly (p < 0.05) lower in Swiss nude than in BALB/c mice; and (4) whereas hypothalamic CRH and pituitary ACTH contents were similar in both strains, adrenal B content was significantly (p < 0.05) lower in athymic mice. Immune reconstitution of the athymic nude mice by injecting splenocytes obtained from syngeneic heterozygous (i.e., immunologically fully competent) donors produced a significant increase in the B adrenal content of the nude mice. Among the splenocytes, CD4+ T-lymphocytes play a particularly important role in the release of ACTH from cells of the immune system. In conclusion, our results indicate that athymic nude mice have a blunted HPA axis response to various stresses and stimuli; this defect seems to reside at both the pituitary and adrenal levels. Immune reconstitution of the nude mice leads to a normalization of the adrenal B content.

The effect of intensity windowing on the detection of simulated masses embedded in dense portions of digitized mammograms in a laboratory setting

The purpose of this study was to determine whether intensity windowing (IW) improves detection of simulated masses in dense mammograms. Simulated masses were embedded in dense mammograms digitized at 50 microns/pixel, 12 bits deep. Images were printed with no windowing applied and with nine window width and level combinations applied. A simulated mass was embedded in a realistic background of dense breast tissue, with the position of the mass (against the background) varied. The key variables involved in each trial included the position of the mass, the contrast levels and the IW setting applied to the image. Combining the 10 image processing conditions, 4 contrast levels, and 4 quadrant positions gave 160 combinations. The trials were constructed by pairing 160 combinations of key variables with 160 backgrounds. The entire experiment consisted of 800 trials. Twenty observers were asked to detect the quadrant of the image into which the mass was located. There was a statistically significant improvement in detection performance for masses when the window width was set at 1024 with a level of 3328. IW should be tested in the clinic to determine whether mass detection performance in real mammograms is improved.

Does intensity windowing improve the detection of simulated calcifications in dense mammograms?

This study attempts to determine whether intensity windowing (IW) improves detection of simulated calcifications in dense mammograms. Clusters of five simulated calcifications were embedded in dense mammograms digitized at 50-microns pixels, 12 bits deep. Film images with no windowing applied were compared with film images with nine different window widths and levels applied. A simulated cluster was embedded in a realistic background of dense breast tissue, with the position of the cluster varied. The key variables involved in each trial included the position of the cluster, contrast level of the cluster, and the IW settings applied to the image. Combining the ten IW conditions, four contrast levels and four quadrant positions gave 160 combinations. The trials were constructed by pairing 160 combinations of key variables with 160 backgrounds. The entire experiment consisted of 800 trials. Twenty student observers were asked to detect the quadrant of the image in which the mass was located. There was a statistically significant improvement in detection performance for clusters of calcifications when the window width was set at 1024 with a level of 3328, and when the window width was set at 1024 with a level of 3456. The selected IW settings should be tested in the clinic with digital mammograms to determine whether calcification detection performance can be improved.

Laser Rapid Prototyping of Photonic Band-Gap Microstructures

Three-dimensional periodic microstructures of aluminum oxide, which are important for creating photonic band-gap structures (PBGs), were fabricated by laser rapid prototyping by means of laser-induced direct-write deposition from the gas phase. The structures consisted of layers of parallel rods forming a face-centered tetragonal lattice with lattice constants of 66 and 133 micrometers. These structures showed transmission minima centered around 4 terahertz (75 micrometers) and 2 terahertz (150 micrometers), respectively. PBGs will allow precise control of the optical properties of materials, including lasers without threshold.

A formal curriculum in breast imaging for radiology residents

RATIONAL AND OBJECTIVES

Training in breast imaging is highly variable among radiology programs. The authors have developed a standardized breast imaging curriculum for radiology residents.

METHODS

This curriculum has been implemented within the residency program at the University of North Carolina at Chapel Hill. It includes nine standardized components: 1) the clinical activities of the service; 2) the study of breast imaging teaching file films and contribution of new cases; 3) selected readings; 4) formal discussion with faculty on the readings; 5) review of this material using an interactive computer program; 6) formal conferences; 7) technical and quality control activities; 8) research activities; and 9) an evaluation. The participating residents have been surveyed regarding their opinions of their educational experience.

RESULTS AND CONCLUSION

The standardized curriculum has been well received by the participating residents. Conclusions about the educational efficacy of such a curriculum cannot be made until more residents have used it.

Restoration of daunomycin retention in multidrug-resistant P388 cells by submicromolar concentrations of SDZ PSC 833, a nonimmunosuppressive cyclosporin derivative

Overexpression of P-glycoprotein may cause increased efflux of a variety of anticancer drugs (ACD) leading to multidrug resistance (MDR) of tumor cells. Two sublines of murine monocytic leukemia P388 cells were used, one parental (Par-P388) and one multidrug resistant (MDR-P388). In cell growth inhibition assays in vitro, the Par-P388 cells showed a normal sensitivity to daunomycin (DAU) while the MDR-P388 cells were 200-fold resistant. In cellular fluorescence assays, DAU retention in MDR-P388 cells reached only 5% of the level achieved in Par-P388 cells. This cell line pair was used to compare the nonimmunosuppressive cyclosporin analog PSC 833 with several resistance-modifying agents (RMAs) for their in vitro chemosensitizing activity and for their restoration of DAU retention. PSC 833 sensitized the MDR-P388 cells 60- and 140-fold when used at 0.1 and 0.3 micrograms/ml (0.08 and 0.25 microM), respectively, a complete restoration of sensitivity being obtained at 1.0 micrograms/ml PSC 833. Similarly as little as 0.1 micrograms/ml (0.08 microM) PSC 833 was sufficient to restore intracellular DAU retention to 60% of the level found in Par-P388 cells, a 3-fold higher concentration restoring virtually the whole DAU retention. For both these activities, PSC 833 was at least one order of magnitude more active than CsA, which was itself an order of magnitude stronger than verapamil, another RMA already used in clinic. Since PSC 833 had no effect on the PAR-P388 cells, neither on chemosensitization nor on drug retention, it is assumed that it acts on the P-glycoprotein, which is highly expressed on the membrane of the MDR-P388 cells, by inhibiting the function of the P-glycoprotein pump and thus restoring a normal ACD-sensitivity of the MDR-P388 cells.

Clinical evaluation of the ITI (F-type) hollow cylinder implant

In 1976 the hollow cylinder implant was introduced. A number of articles have been published about the ITI implant system. In this article, short-term results of 102 ITI F-type implants in 40 patients are reported. The results showed this one-stage implant to be at least comparable to other well-known implant systems.

Neuromuscular effects of isoflurane in patients with myasthenia gravis

Seventeen myasthenia gravis and seven control patients were studied mechano (MMG)- and electromyographically (EMG) during isoflurane/oxygen/air anaesthesia. In myasthenic patients the mean train-of-four ratio and neuromuscular block (by MMG) during 1.9 MAC isoflurane anaesthesia were 55 +/- 9% and 46 +/- 12%, respectively. The correlation between simultaneous MMG and EMG measurements was excellent (r2 = 0.933, P less than 0.001). The occurrence of HLA-B8 together with acetylcholine receptor antibodies seems to predispose myasthenic patients to a neuromuscular depression produced by isoflurane. Our current and prior results show that isoflurane possesses approximately twice as strong a neuromuscular blocking effect as halothane in myasthenic patients.

1 alpha,25-Dihydroxyvitamin D3 and a novel vitamin D analogue MC 903 are potent inhibitors of human interleukin 1 in vitro

1 alpha,25-dihydroxycholecalciferol (1,25(OH)2D3) inhibits the lymphocyte growth hormone, interleukin 2. Since its production is dependent upon interleukin 1 (IL-1) produced by antigen-presenting cells, we tested five vitamin D3 analogues for effects on the production and function of human natural and recombinant IL-1. The production was not affected, but 1,25(OH)2D3 (greater than 10(-11) M) and a synthetic derivative MC 903 (greater than = 10(-10) M) inhibited the proliferation of mouse thymocytes to IL-1. The vitamins failed to affect the cytotoxic activity of tumor necrosis factor. 1,25(OH)2D3 may play a physiological immunomodulatory role as a selective inhibitor of the function of IL-1, and MC 903 may prove clinically useful in this regard because of its limited calcium metabolic activity.

Analysis of responding lymphocyte subsets in allogeneic mixed lymphocyte cultures in the neonates and adults

An analysis of proliferating cell subsets in the allogeneic mixed lymphocyte culture (MLC) in adults (n = 19) and newborns (n = 12) was performed by a method combining immunoperoxidase staining and autoradiography. The main cell type responding in adult cells were OKT8-positive (38%), whereas in neonates OKT4-positive cells (31%) predominated. Furthermore, in the neonatal allogeneic MLC there were significantly more 3H-thymidine incorporating Leu 12-positive B cells than in adults (12% vs 4%).

Role of subunit interactions in the self-assembly of oligomeric proteins

In oligomeric proteins, the native conformation and its functional properties depend on the interactions which exist between the different chains. The role of these subunit interactions can be studied using either the unfolded state or the native state as a starting point. During the folding process, the properties which appear following a bimolecular reaction are related to the formation of an association area. Similarly, the properties which are lost upon partial dissociation of the native state are related to the association area which is disrupted. Four examples are presented in this article: phosphofructokinase and aspartokinase-homoserine dehydrogenase from E. coli are studied through their folding process, and fatty acid synthetase from B. ammoniagenes and reptilian ovomacroglobulin are studied through their dissociated forms. In all cases, the function of the protein is a sensitive index of the formation of the subunit interactions, and can be more conveniently measured than other size/shape parameters. The extrapolation from the folding of small proteins to the assembly of large and complex structures can be reasonably achieved by admitting that subunit interactions are coupled to the subtle adjustments required by the protein to exert its biological function.

Allogeneic bone-marrow transplantation in infantile malignant osteopetrosis

Two infants with malignant osteopetrosis were treated by allogeneic bone-marrow transplantation after marrow ablation with busulphan and cyclophosphamide. Engraftment without graft-vs-host disease occurred in both cases. The first child established stable chimerism and is clinically well 30 months after receiving a histocompatible sibling bone-marrow graft: haematological, radiological, and biochemical features of osteopetrosis have completely resolved. The second child was non-identical with the marrow donor (his older sister) at a single HLA-B locus and received cyclosporin A as prophylaxis for graft-vs-host disease. 11 months after transplantation haematological abnormalities have resolved and radiological features have improved. The findings indicate that allogeneic bone-marrow transplantation should be considered the treatment of choice for infants with severe osteopetrosis who have histocompatible siblings.

Effects of low to moderate lead exposure on slow cortical potentials in young children: two year follow-up study

A follow-up study of slow cortical potentials in children with elevated blood lead (PbB) histories was conducted two years after initial evaluation. An age x PbB interaction was again observed wherein slow wave (SW) voltage varied as a linear function of PbB with the slope of the function dependent on age. The linear relationship of SW voltage and PbB was significant using either original PbB values, (14-55 micrograms/dl), follow-up values (11-39 micrograms/dl), or the mean of the two PbB values. No evidence of a threshold for this effect was observed. The similarity of results obtained at initial and follow-up assessments suggests that the observed alterations in CNS function are persistent, despite a significant decrease in mean PbB across time. The observed change in SW voltage at PbB levels previously considered to be harmless suggests the need to reconsider the currently accepted 30 micrograms/dl threshold for undue lead absorption in children.

Biochemical changes in humans upon exposure to nitrogen dioxide while at rest

The biological response to controlled exposures of nitrogen dioxide (NO2) was studied in 19 human subjects exposed to 0.2 ppm NO2 for 2 hr and compared to 15 control subjects exposed to filtered air for 2 hr. Seven biochemical blood parameters, including glutathione, red blood cell glutathione reductase, 2,3-diphosphoglycerate, methemoglobin, vitamin E, complement C2, and IgA were measured prior to exposure, immediately after exposure, and 22 hr following exposure. The only variable that showed significant change due to NO2 exposure was glutathione. Glutathione is known to protect the erythrocyte from oxidative stress. The increase in glutathione observed upon exposure to NO2 may be a protective reaction of the erythrocyte to meet the oxidative stress.

Biochemical effects of sulfuric acid mist inhalation by human subjects while at rest

This study evaluated the effect of sulfuric acid aerosol exposure for 2 consecutive days on seven human biochemical blood parameters. A total of 20 human subjects were exposed to 100 micrograms/m3 (0.033 microM) sulfuric acid aerosol (0.5 microns mean mass diameter) for 4 hr/day for 2 consecutive days. A total of 17 human subjects were exposed to 4 hr of ambient air on both exposure days. The chemical blood parameters were measured pre- and post-exposure, and 20 hr after the second exposure: serum glutathione, red blood cell glutathione reductase, red blood cell glucose-6-phosphate dehydrogenase, lysozyme, serum glutamic oxaloacetic acid transaminase, serum vitamin E, and 2, 3-diphosphoglycerate. The results indicate no significant response in any of the seven biochemical blood parameters measured. At this level, repeated exposure did not over-burden the upper airway defenses against acid aerosol.

Biochemical changes in humans upon exposure to sulfuric acid aerosol and exercise

This study evaluated the effect of a single exposure to sulfuric acid aerosol on six human biochemical blood parameters. A total of 18 human subjects were exposed to ambient air for 4 hr on the first day of exposure and to 100 microgram/m3 (0.033 microM) sulfuric acid aerosol (0.5 micrometer mean mass diameter) for 4 hr on the second day. A total of 17 human subjects were exposed for 4 hr to ambient air on both exposure days. On each exposure day, at 30 min and 90 min after exposure was initiated, all subjects engaged in a 15-min exercise period (walking 4 mph on a treadmill inclined at 10 degrees). Six biochemical blood parameters were measured before and after exposure: glutathione, lysozyme, glutathione reductase, serum glutamic oxaloacetic acid transaminase, serum vitamin E, and 2, 3-diphosphoglyceric acid. The results indicate no significant effect of one 4-hr exposure of humns to 100 microgram/m3 sulfuric acid aerosol. One significant post-exposure effect did occur--an increase in glutathione reductase--for both the control and acid-exposed group. It is concluded that at the levels studied, sulfuric acid aerosol is neutralized in the upper airways; consequently, no cellular damage is measurable.

Effects of various hypolipidemic drugs on fatty acid composition of liver and serum lipids

1. Treatment of rats with hypolipidemic drugs elicited an increase in oleic and a decrease in linoleic acid content in cholesterol esters, triglycerides and phospholipids of serum and liver lipids. 2. The change was most pronounced in triglycerides followed by cholesterol esters and phospholipids. 3. The shift was dose-dependent, starting with doses eliciting hypolipidemic effects. 4. The shift became obvious immediately after beginning of treatment and reached after 4 days a new steady state. 5. This effect was shared by both drugs of aryloxy fatty acid structure, but was not seen with either L-thyroxine or nicotinic acid. 6. The mechanism underlying this phenomenon is thus far unknown, but in our view it merits further attention.