Tyrosine hydroxylase gene promoter activity is regulated by both cyclic AMP-responsive element and AP1 sites following calcium influx. Evidence for cyclic amp-responsive element binding protein-independent regulation.

Membrane depolarization of PC12 cells using 50 mM KCl leads to induction of tyrosine hydroxylase (TH) mRNA. This induction of TH mRNA is apparently due to increased TH gene promoter activity mediated by the influx of Ca2+. In PC12 cells transiently transfected with a chimeric gene expressing chloramphenicol acetyltransferase (CAT) driven by the proximal TH gene 5'-flanking region, 50 mM KCl increases TH gene promoter activity 3-4-fold. Promoter analysis utilizing TH-CAT constructs containing mutagenized sequences indicates that this response to the depolarization-mediated influx of Ca2+ is primarily dependent on both the TH cAMP-responsive element (CRE) and TH activating protein-1 (AP1) site. Minimal promoter constructs that contain a single copy of either the TH CRE or TH AP1 site fused upstream of the TH gene basal promoter are only modestly responsive or nonresponsive, respectively, to depolarization. However, both these constructs are strongly responsive to the calcium ionophore, A23187. Gel shift assays indicate that TH AP1 complex formation is dramatically increased after treatment with either 50 mM KCl or A23187. Using antibodies to transcription factors of the Fos and Jun families, we show that the nuclear proteins comprising the inducible TH AP1 complex include c-Fos, c-Jun, JunB, and JunD. In cAMP-responsive element binding protein (CREB)-deficient cell lines that express antisense RNA complementary to CREB mRNA, the response of the TH gene promoter to cyclic AMP is dramatically inhibited, but the response to A23187 remains robust. This result indicates that transcription factors other than CREB can participate in the Ca2+-mediated regulation of the TH gene. In summary, our results support the hypothesis that regulation of the TH gene by Ca2+ is mediated by mechanisms involving both the TH CRE and TH AP1 sites and that transcription factors other than or in addition to CREB participate in this response.

The response of the tyrosine hydroxylase gene to cyclic AMP is mediated by two cyclic AMP-response elements.

Tyrosine hydroxylase (TH) gene transcription rate is stimulated by cyclic AMP in cultured rat pheochromocytoma cells. This effect is at least partially due to the interaction of transcription factors with the canonical cyclic AMP-response element (CRE) at position -45 to -38 within the TH gene promoter. In this study we test whether a region of the TH gene promoter, which is adjacent to and upstream of the canonical TH CRE, also participates in the response of the promoter to cyclic AMP. Using electrophoretic mobility shift assays, we demonstrate that nuclear proteins from rat pheochromocytoma cell lines bind to the region of the TH gene from -102 to -73. A comparison of promoter sequences indicates that sequences within this region of the TH gene are highly homologous to proenkephalin promoter sequences (between -110 and -80) designated ENKCRE-1 and ENKCRE-2. We designated the TH gene sequence homologous to ENKCRE-1 as TH E1 and the sequence homologous to ENKCRE-2 as TH E2. Competition displacement binding assays suggest that protein binding to the -102/-73 region of the TH gene is critically dependent on the TH E1 sequence. Transient transfection assays using minimal promoter constructs demonstrate that this region acts as a cyclic AMP-responsive element. Mutagenesis of the TH E1 sequence within the normal context of the TH gene proximal promoter leads to a 50% decrease in the cyclic AMP inducibility of the promoter. These results support the hypothesis that the full response of the TH gene to cyclic AMP requires both the canonical TH CRE and this newly discovered element, which we term TH CRE2.

Noncardiac pulmonary edema, newer environmental aspects. An update.

Accidental spread of potentially toxic gases, fumes, and particulate chemicals has been reported recently in various cities throughout the country and appears to be on the increase throughout the world in the past few years. Moreover, cerebral trauma, septic shock (ARDS), and environmental pulmonary edema from drug intoxication have been commonly encountered. Newer modalities of treatment include selective [corrected] fiber optic bronchoscopy, constant positive airway pressure mask, administration of surfactant, pentoxifylline, and use of newer experimental agents such as nitrous oxide, antitumor necrosis factor (ATNF), and extracorporeal carbon dioxide with low-frequency positive pressure (ECCO2R-LFPPV). The future holds promise for probable reductions in both morbidity and mortality rates of this ubiquitous occupational and environmental health problem, which is of global importance.

Autonomic modulation of action potential and tension in guinea pig papillary muscles.

The effects of alpha 1-adrenoceptor and muscarinic acetylcholine receptor stimulation on action potential and tension were studied in guinea pig papillary muscles obtained from both right and left ventricles. Stimulation of muscarinic acetylcholine receptors with carbachol produced a reduction of the action potential duration and a positive inotropic effect in papillary muscles from both ventricles. Both effects were concentration dependent and atropine sensitive. However, differential responsiveness was found upon alpha 1-adrenoceptor activation in muscles obtained from left and right ventricles. In right side papillary muscles, the alpha 1-adrenoceptor agonist, methoxamine, decreased the action potential duration and produced a positive inotropic effect. In contrast, methoxamine decreased the action potential duration but failed to produce a positive inotropic effect in left side papillary muscles. All methoxamine effects were antagonized by prazosin. Responses to maximum concentration of carbachol and methoxamine on the action potential duration and contractility were additive in right side papillary muscles. Phorbol 12,13-dibutyrate (PDB), a direct protein kinase C activator, also decreased the action potential duration in a manner that was additive to both carbachol and methoxamine. However, PDB reversed the positive inotropic effect of carbachol and methoxamine. The methoxamine-induced shortening of the action potential duration was prevented by pretreatment with indomethacin and nordihydroguaiaretic acid, blockers of arachidonic acid metabolism, but not by the protein kinase C antagonist, 1-(5-isoquinolinesulfonyl)-2-methylpiperazine (H-7).(ABSTRACT TRUNCATED AT 250 WORDS)

A clinico-pathological study of yellow fever with demonstration of the virus in the human liver

The clinical histopathological and serological findings in three patients who developed yellow fever after entering the Guayaguayare forest in south-east Trinidad in January and February 1979 are described in this report. The patients were all previously healthy young males and the clinical features of the disease varied from fulminant viral hepatitis with hepato-renal failure to a self-limiting anicteric viral illness. The first patient died, and histopathological examination of the liver was done post-mortem. Needle biopsy of the liver was done on case 2 which presented with the clinical picture of infective hepatitis, and on case 3 with the features of an anicteric viral illness. The histopathological hallmarks of midzonal necrosis, granular eosinophilic degeneration (Councilman bodies) and fatty change in the parenchymal cells of the liver were seen in three cases. The electron microscopic study demonstrated the presence of the yellow fever virus in the liver of the patient who died (AU)

A clinico-pathological study of yellow fever with demonstration of the virus in the human liver

The clinical histopathological and serological findings in three patients who developed yellow fever after entering the Guayaguayare forest in south-east Trinidad in January and February 1979 are described in this report. The patients were all previously healthy young males and the clinical features of the disease varied from fulminant viral hepatitis with hepato-renal failure to a self-limiting anicteric viral illness. The first patient died, and histopathological examination of the liver was done post-mortem. Needle biopsy of the liver was done on case 2 which presented with the clinical picture of infective hepatitis, and on case 3 with the features of an anicteric viral illness. The histopathological hallmarks of midzonal necrosis, granular eosinophilic degeneration (Councilman bodies) and fatty change in the parenchymal cells of the liver were seen in three cases. The electron microscopic study demonstrated the presence of the yellow fever virus in the liver of the patient who died.

Hyperspectral interactions: invariance and scaling.

We present new invariance and scaling results for scale space analysis of hyperspectral data. First, we note that a hyperspectral curve can be segmented into independent regions selected by features of scale space fingerprints. These fingerprint features are persistent inflection points that precisely locate major atmospheric features that define the regions. The strength and location of hyperspectral features in one atmospheric region are independent of features in other regions; as a result, hyperspectral analysis can be simplified to a region-by-region analysis. We then generate simple scaling and invariance rules for features within such a spectral region. We show that the scale of individual features is independent of the details of feature shape and depends only on the area of the feature. Interacting features in turn exhibit a fascinating bifurcation behavior: at large separations features behave independently; at smaller separations features interact and their scales are damped; below a critical separation distance (the bifurcation point) the features nest. The scales of features above the bifurcation point, the scales of the nested features, and the location of the bifurcation point depend only on the feature areas and not on shape-associated parameters of the individual features.

Symbolic representation of hyperspectral data.

We have developed a symbolic representation of hyperspectral data using the scale space techniques of Witkin. We created a scale space image of hyperspectral data from convolution with Gaussian masks and then a fingerprint that extracts individual features from the original data. The fingerprint provides a context that pairs inflection points and assigns them to a feature, generates a measure of importance for each feature, and relates features to each other. The representation is an ordered sequence of triplets containing a measure of importance related to the area of each feature and the left and right inflection points of the feature. The description is compact, quantitative, and hierarchical, describing the hyperspectral curve by its most important structural features first, followed by features of lesser importance.

Multiple scattering of laser light from a turbid medium.

Through a controlled laboratory study, theoretical modeling was developed that accurately relates the reflectance of turbid water to the concentrations of suspended and dissolved materials; this modeling will be useful in quantitatively mapping pollutant concentrations in lakes and rivers through aerial photography. Laser light illuminated water containing both Teflon particles and black dye. Over a large range of concentrations of these scattering and absorbing materials, measured reflectance was successfully predicted by a multiple scattering analysis. (Single scatter analysis produced serious errors.) The theoretical development involved solving the radiative transport equation and accounted for correlated scattering from closely spaced particles.