Showing papers by "Tulane University published in 1991"

Correlation hole of the spin-polarized electron gas, with exact small-wave-vector and high-density scaling

Abstract: For a uniform electron gas of density n=${\mathit{n}}_{\mathrm{\ensuremath{\uparrow}}}$+${\mathit{n}}_{\mathrm{\ensuremath{\downarrow}}}$=3/4\ensuremath{\pi}${\mathit{r}}_{\mathit{s}}^{3}$=\ensuremath{\pi}${\mathit{k}}_{\mathit{s}}^{6}$/192 and spin polarization \ensuremath{\zeta}=(${\mathit{n}}_{\mathrm{\ensuremath{\uparrow}}}$-${\mathit{n}}_{\mathrm{\ensuremath{\downarrow}}}$)/n, we study the Fourier transform \ensuremath{\rho}${\mathrm{\ifmmode\bar\else\textasciimacron\fi{}}}_{\mathit{c}}$(k,${\mathit{r}}_{\mathit{s}}$,\ensuremath{\zeta}) of the correlation hole, as well as the correlation energy ${\mathrm{\ensuremath{\varepsilon}}}_{\mathit{c}}$(${\mathit{r}}_{\mathit{s}}$,\ensuremath{\zeta})=${\mathcal{F}}_{0}^{\mathrm{\ensuremath{\infty}}}$dk \ensuremath{\rho}${\mathrm{\ifmmode\bar\else\textasciimacron\fi{}}}_{\mathit{c}}$/\ensuremath{\pi}. In the high-density (${\mathit{r}}_{\mathit{s}}$\ensuremath{\rightarrow}0) limit, we find a simple scaling relation ${\mathit{k}}_{\mathit{s}}$\ensuremath{\rho}${\mathrm{\ifmmode\bar\else\textasciimacron\fi{}}}_{\mathit{c}}$/\ensuremath{\pi}${\mathit{g}}^{2}$\ensuremath{\rightarrow}f(z,\ensuremath{\zeta}), where z=k/${\mathit{gk}}_{\mathit{s}}$, g=[(1+\ensuremath{\zeta}${)}^{2/3}$+(1-\ensuremath{\zeta}${)}^{2/3}$]/2, and f(z,1)=f(z,0). The function f(z,\ensuremath{\zeta}) is only weakly \ensuremath{\zeta} dependent, and its small-z expansion -3z/${\mathrm{\ensuremath{\pi}}}^{2}$+4 \ensuremath{\surd}3 ${\mathrm{z}}^{2}$/${\mathrm{\ensuremath{\pi}}}^{2}$+... is also the exact small-wave-vector (k\ensuremath{\rightarrow}0) expansion for any ${\mathit{r}}_{\mathit{s}}$ or \ensuremath{\zeta}. Motivated by these considerations, and by a discussion of the large-wave-vector and low-density limits, we present two Pad\'e representations for \ensuremath{\rho}${\mathrm{\ifmmode\bar\else\textasciimacron\fi{}}}_{\mathit{c}}$ at any k, ${\mathit{r}}_{\mathit{s}}$, or \ensuremath{\zeta}, one within and one beyond the random-phase approximation (RPA). We also show that \ensuremath{\rho}\ifmmode\bar\else\textasciimacron\fi{} $_{\mathit{c}}^{\mathrm{RPA}}$ obeys a generalization of Misawa's spin-scaling relation for ${\mathrm{\ensuremath{\varepsilon}}}_{\mathit{c}}^{\mathrm{RPA}}$, and that the low-density (${\mathit{r}}_{\mathit{s}}$\ensuremath{\rightarrow}\ensuremath{\infty}) limit of ${\mathrm{\ensuremath{\varepsilon}}}_{\mathit{c}}^{\mathrm{RPA}}$ is \ensuremath{\sim}${\mathit{r}}_{\mathit{s}}^{\mathrm{\ensuremath{-}}3/4}$.

Perceived fairness of employee drug testing as a predictor of employee attitudes and job performance.

Abstract: Although management of drug testing programs is becoming a critical organizational issue, no systematic conceptual framework has been applied to the study of employee reactions to drug testing. In this study an organizational justice framework was used to explain and predict the relationships among two types of justice (procedural justice and outcome fairness) employee attitudes (job satisfaction, commitment, and management trust), and behavior (turnover intentions and performance). Survey data from 195 employees in a pathology laboratory indicated that justice predicts employee attitudes and performance. Specifically, procedural justice, but not outcome fairness, predicted all 5 criterion variables. These results demonstrate the importance of procedural justice perceptions for predicting employee reactions to drug testing programs.

Tissue distribution of PACAP as determined by RIA: highly abundant in the rat brain and testes.

Abstract: A heterologous RIA method for pituitary adenylate cyclase activating polypeptide with 38 residues (PACAP38) and a homologous RIA method for a shorter form of PACAP with 27 residues (PACAP27) were established to determine PACAP content in central and peripheral tissues in rats. The highest concentration of radioimmunoassayable PACAP38 was found in the hypothalamus, but other brain regions also contained considerable amounts of PACAP38. PACAP38 concentration in the posterior pituitary was comparable with that in the extrahypothalamic brain, but its concentration in the anterior pituitary was very low. Unexpectedly, the testis contained a high abundance of PACAP38, and the total amount of PACAP in both testes exceeded its content in the whole brain. Reverse phase HPLC suggested that the major testicular PACAP38 immunoreactivity represents PACAP38. Among peripheral tissues, adrenal gland contained the second highest concentration of PACAP. Smaller amounts of PACAP were widely distributed in the digestive trac...

Idiopathic intracranial hypertension. A prospective study of 50 patients.

Abstract: Management of patients with idiopathic intracranial hypertension (IIH) should be based on the presence and progression of visual loss. To characterize the clinical course of IIH more completely, we monitored the clinical status, especially visual function, in 50 consecutive newly-diagnosed patients over a period of 2 to 39 months (average follow-up 12.4 months). The mean age at onset of symptoms was 31 (range 11-58) yrs; 46 (92%) were women and 47 (94%) were obese (mean weight 90 kg). Common symptoms were headache (92%), transient visual obscurations (72%) and intracranial noises (60%); 13 of the patients (26%) initially had complaints of sustained visual loss. There was visual loss as determined by Goldmann perimetry in 96% and by automated perimetry in 92%. Contrast sensitivity testing was abnormal in 50% and Snellen acuity in 22%. Two patients (4%) became blind in both eyes. The Goldmann visual field grade improved in 60% of patients but visual function deteriorated in 5 (10%). Deterioration of visual field grade was significantly associated only with weight gain during the year before diagnosis. Visual loss in patients with IIH is common and is often reversible. Patients should be evaluated by perimetry using an appropriate strategy and contrast sensitivity testing, along with careful examination of the optic discs.

Symptoms and disease associations in idiopathic intracranial hypertension (pseudotumor cerebri) A case‐control study

Abstract: To identify the symptoms and coexisting medical conditions associated with idiopathic intracranial hypertension (IIH), we administered an 83-item questionnaire at the time of diagnosis to 50 IIH patients and 100 aged-matched controls. Ninety percent of the IIH patients were women; the mean age was 33. Obesity and recent weight gain were much more common among patients than controls. Symptoms most commonly reported by IIH patients were headache (94%), transient visual obscurations (TVO) (68%), and intracranial noises (ICN) (58%). Daily occurrence of these symptoms was much more common among patients than controls. Controls also reported these and other IIH symptoms, but at lower frequencies. Several conditions previously associated with IIH were no more common in patients than controls including iron deficiency anemia, thyroid disease, pregnancy, antibiotic intake, and use of oral contraceptives. We conclude that previous studies of IIH, mostly uncontrolled and retrospective, have underestimated the frequency of symptoms in IIH patients and reported chance and spurious associations with common medical conditions and medications. The profile of a young obese woman with headaches and either TVO or ICN should alert the clinician to the diagnosis of IIH, especially when the symptoms occur daily.

Two High Affinity Binding Sites for Pituitary Adenylate Cyclase-Activating Polypeptide Have Different Tissue Distributions*

Abstract: Two bioactive products of pituitary adenylate cyclase-activating polypeptide (PACAP) prohormone have been isolated from ovine hypothalamus: PACAP38 with 38 residues and PACAP27 corresponding to the N-terminal 27 residues of PACAP38. Immunocytochemical and RIA results support the existence of PACAP in the rat brain, posterior pituitary, and various peripheral tissues. Furthermore, high affinity PACAP-binding sites have been detected in the rat brain, anterior pituitary, and cultured astrocytes which differ from those in lung, liver, and cultured mouse splenocytes. In the present study additional rat tissues were examined to elucidate the location and characteristics of PACAP-binding sites using [125I] PACAP27 with conventional methods of receptor autoradiography and RRA. Binding specificity was established by displacement with unlabeled PACAP27 or a related peptide, vasoactive intestinal polypeptide (VIP). PACAP27-binding sites were localized autoradiographically in the testis, epididymis, adrenal gland, lung, liver, prostate gland, and seminal vesicle; binding sites were not detected in the heart, kidney, or thymus. In the testis and epididymis, a PACAP27-binding site was localized on germinal cells and in the adrenal gland on medullary chromaffin cells. Excess VIP did not displace PACAP27 binding localized in these three tissues. A site with a greater affinity for PACAP27 than for VIP was detected in adrenal gland and epididymis, characteristic of a site recognized previously in hypothalamus, anterior pituitary, and cultured astrocytes. The PACAP-specific site was more abundant in these tissues than a second site to which PACAP27 and VIP bound with similar affinities. Accordingly, the first site has been named type I. In lung, liver, prostate, and seminal vesicle, VIP displaced PACAP27 binding localized autoradiographically. Lung and liver contained an abundant site to which PACAP27 and VIP bound with similar affinities. This binding site, measured previously in lung, liver, and cultured splenocytes, may be shared by PACAP and VIP and has been named type II. Taken together, these data support the existence of two high affinity binding sites for PACAP with different tissue distribution.

On the Actions of the Growth Hormone-Releasing Hexapeptide, GHRP

Abstract: GH-releasing peptide (His-DTrp-Ala-Trp-DPhe-Lys-NH2 or GHRP) releases GH by a unique and complementary dual site of action on the hypothalamus and pituitary. These effects are mediated via non-GH-releasing hormone (non-GHRH) and nonopiate receptors in rats. Select types of opiates are known to release GH by a hypothalamic site of action, and thus, the dermorphin heptapeptide and benzomorphan opiate agonist 2549 used in this study presumably act on the hypothalamus to release GH. Neither dermorphin nor 2549 released GH or augmented the GH responses of GHRP or GHRH in vitro by a direct pituitary action, while GHRH antiserum inhibited the GH response of both dermorphin and 2549 in vivo. Evidence indicates that these opiates and GHRP administered together synergistically release GH, demonstrating the independent action(s) of GHRP and the opiates. Present data indicate that one of the major differences in the actions of dermorphin, 2549, and GHRP is the inhibition of somatostatin (SRIF) release by the opiates but not by GHRP. Although the actions of dermorphin, 2549, and GHRP on GH release are GHRH dependent, release of endogenous GHRH does not explain how GH is released synergistically by the combination of these peptides. It is proposed that dermorphin/2549 synergistically release GH with GHRP or GHRH because these opiates inhibit SRIF release. Since the GHRP plus GHRH synergistic GH release was not explained by inhibition of SRIF or stimulation of GHRH, an alternative mechanism is proposed to explain how GHRP synergistically release GH in combination with GHRH. The complementary, rather dramatic synergistic interaction of GHRP, GHRH, and dermorphin or GHRP, GHRH, and 2549 in releasing GH again strongly supports the independent actions of these compounds.

The spline-Laplacian in clinical neurophysiology: a method to improve EEG spatial resolution.

Abstract: SummaryAn important goal of EEG research is to obtain practical methods to improve the spatial resolution of scalp-recorded potentials, i.e., to make surface data more accurately represent local underlying brain sources. This goal may be somewhat different from that of “localizing brain activity wit

Comparative distribution of immunoreactive pituitary adenylate cyclase activating polypeptide and vasoactive intestinal polypeptide in rat forebrain.

Abstract: Pituitary adenylate cyclase activating polypeptide (PACAP) and vasoactive intestinal polypeptide (VIP) are structurally similar, share the same high affinity site in same peripheral tissues and increase the intracellular content of adenylate cyclase. To establish which neural circuits are signaling with each of these two peptides, we systematically compared the immunohistochemical distribution of PACAP and VIP in selected rat forebrain regions using previously characterized antiserum. The PACAP antiserum recognized both PACAP27 and PACAP38, and PACAP immunoreactivity was unaffected by preincubation with various other peptides. PACAP-immunoreactive perikarya and fibers were observed in both hypothalamic and extrahypothalamic regions. In the hypothalamus PACAP perikarya were located in the supraoptic, paraventricular, anterior commissural, periventricular, and perifornical nuclei. In intact rats PACAP immunolabeled fibers were present in the internal zone of the median eminence and posterior pituitary. One week after hypophysectomy the intensity of staining in the internal zone was enhanced and immunoreactive fibers appeared in the external zone of the median eminence. Two or 3 weeks later a dense fiber network was observed around the portal capillaries in the external zone, and immunoreactive material further accumulated in the fibers of the internal zone. PACAP-immunoreactive perikarya and fibers were also observed in several extrahypothalamic regions including central thalamic nuclei, amygdaloid complex, bed nucleus of stria terminalis, septum, hippocampus and cingulate, and entorhinal cortices. In the lateral septum and entorhinal cortex PACAP fibers surrounded unstained neuronal cell bodies and small blood vessels. In intact rats, VIP-immunoreactive perikarya were present in all regions of the cerebral cortex, hippocampus, amygdaloid complexus and in the suprachiasmatic nucleus, but not in the paraventricular and supraoptic nuclei. In colchicine-treated rats the VIP perikarya appeared in the preoptic area and paraventricular nucleus. The fibers were organized in two main pathways: the stria terminalis and an ascending pathway from the suprachiasmatic nucleus to the paraventricular area. Hypophysectomy induced the appearance of VIP-immunoreactive fibers in the internal zone of the median eminence and perikarya in the supraoptic and paraventricular nuclei in addition to the suprachiasmatic nucleus. The dissimilar distributions of PACAP and VIP suggest that PACAP neural circuits are independent of that of VIP in the rat forebrain. These findings support possible multifunctional roles for PACAP as a posterior pituitary hormone, a hypophysiotrophic factor, and a neurotransmitter/neuromodulator.

Generalized gradient approximations for exchange and correlation : a look backward and forward

Abstract: Ground-state properties of many-electron systems are calculable from the exchange-correlation energy as a functional of the electron spin densities n↑ (r), n↓ (r). After a review of the local spin density (LSD) approximation, the second-order density-gradient expansion (GEA), and the generalized gradient approximation (GGA) for exchange, prospects are discussed for a simple, first-principles GGA for correlation. The new GGA for correlation, like that for exchange, is based upon a real-space cut-off of the spurious long-range part of the gradient expansion for the fluctuation hole around an electron. Scaling relations, which lead to simple functionals, are stressed.

Isolation and Characterization of a New Human Microsporidian, Encephalitozoon hellem (n. sp.), from Three AIDS Patients with Keratoconjunctivitis

Abstract: A new human microsporidian was isolated from cultures of Madin-Darby canine kidney cells incubated with conjunctival scrapings or corneal tissues from three AIDS patients with keratoconjunctivitis. The three isolates were morphologically similar to Encephalitozoon cuniculi. The spores averaged 1 x 1.5-2.0 microns, had six to eight polar filament coils, displayed monokaryotic nuclei, and possessed relatively thick endospores with irregularly shaped exospores. Organisms developed within a parasitophorous vacuole. By SDS-PAGE analysis, the three isolates appeared to be identical but were different from E. cuniculi. Identical banding patterns on Western blots of the three isolates were expressed by each patient's serum. By Western immunoblotting, murine antisera to E. cuniculi reacted to several antigens of the new AIDS-related microsporidian, whereas murine antisera bound weakly to Nosema corneum. The name Encephalitozoon hellem (n. sp.) is proposed to identify this new human microsporidian.

Density-functional exchange correlation through coordinate scaling in adiabatic connection and correlation hole

Abstract: The exact exchange-correlation functional ${\mathit{E}}_{\mathrm{xc}}$[n] must be approximated in density-functional theory for the computation of electronic properties. By the coupling-constant integration (adiabatic-connection) formula we know that ${\mathit{E}}_{\mathrm{xc}}$[n]=${\mathcal{F}}_{0}^{1}$(${\mathit{V}}_{\mathit{e}\mathit{e}}^{\mathrm{\ensuremath{\alpha}}}$[n]-U[n])d\ensuremath{\alpha}, where ${\mathit{V}}_{\mathit{e}\mathit{e}}^{\mathrm{\ensuremath{\alpha}}}$[n] is the electron-electron repulsion energy of ${\mathrm{\ensuremath{\Psi}}}_{\mathit{n}}^{\mathrm{m}\mathrm{i}\mathrm{n},\mathrm{\ensuremath{\alpha}}}$, which is that wave function that yields the density n and minimizes 〈T^+\ensuremath{\alpha}V${\mathrm{^}}_{\mathit{e}\mathit{e}}$〉. Here \ensuremath{\alpha} is the coupling constant. Consequently, knowledge of the behavior of ${\mathit{V}}_{\mathit{e}\mathit{e}}^{\mathrm{\ensuremath{\alpha}}}$[n] as a function of \ensuremath{\alpha} ensures knowledge of ${\mathit{E}}_{\mathrm{xc}}$[n]. With this in mind and for the purpose of approximating ${\mathit{E}}_{\mathrm{xc}}$, it was previously established that (\ensuremath{\partial}${\mathit{V}}_{\mathit{e}\mathit{e}}^{\mathrm{\ensuremath{\alpha}}}$/\ensuremath{\partial}\ensuremath{\alpha})\ensuremath{\le}0. The present paper reveals that ${\mathit{V}}_{\mathit{e}\mathit{e}}^{\mathrm{\ensuremath{\alpha}}}$[n]=\ensuremath{\alpha}${\mathit{V}}_{\mathit{e}\mathit{e}}^{1}$[${\mathit{n}}_{1/\mathrm{\ensuremath{\alpha}}}$], where ${\mathit{n}}_{\mathrm{\ensuremath{\beta}}}$(x,y,z)=${\mathrm{\ensuremath{\beta}}}^{3}$n(\ensuremath{\beta}x,\ensuremath{\beta}y,\ensuremath{\beta}z), and where \ensuremath{\beta} is a coordinate scale factor.

Conversion by retinoic acid of anterior cells into ZPA cells in the chick wing bud

Abstract: IN recent years there has been considerable interest in the role of retinoic acid (RA) in vertebrate-limb pattern formation. When RA is applied to the anterior of the chick wing bud, a mirror-image duplication of the limb pattern develops that is identical to the pattern resulting from grafts of posterior tissue (zone of polarizing activity, or ZPA)1. It has been proposed that position along the anterior-posterior axis in the chick limb is specified by a gradient of a diffusible factor produced by the ZPA2. The ZPA-mimicking action of RA has led to the hypothesis that exogenously applied RA acts by providing graded spatial information across the anterior-posterior limb axis3,4. An alternative interpretation is that RA changes anterior cells into ZPA cells, which in turn provide the actual pattern-duplicating stimulus3-5; there is already some preliminary evidence that this occurs5. A hybrid interpretation has also been suggested whereby ZPA cells are formed in response to RA exposure and then begin to release retinoids that act as graded spatial cues3. We have used a functional assay6 to test anterior chick wing-bud cells for ZPA activity after exposure to RA. The results of our studies indicate that the action of RA is to change anterior cells into ZPA cells. Further, our results indicate that it is unlikely that RA-treated anterior cells then begin producing RA in such a way as to provide a graded positional signal.

Type I corticosteroid receptor-like immunoreactivity in the rat CNS: distribution and regulation by corticosteroids.

Abstract: Previous maps of Type I corticosteroid receptor binding in the rat central nervous system (CNS) revealed a restricted distribution of the receptor in limbic regions, hypothalamus, and circumventricular organs. More recent studies have shown a more widespread expression of the receptor, with high levels of Type I receptor mRNA in limbic, motor, and sensory systems. We have used two antisera against peptide sequences derived from the cDNA of the human Type I corticosteroid receptor to map the regional distribution and corticosteroid regulation of the intracellular location of Type I corticosteroid receptor-like immunoreactivity (Type I-ir) in the rat CNS. Neurons showing Type I-ir were observed at all levels of the CNS. Highest densities of immunoreactive neurons were observed in limbic regions, isocortex, and some thalamic nuclei. Motor, sensory, and visceral systems often showed moderate densities of immunoreactive neurons. Type I-ir glia were observed in some fiber systems, e.g., corpus callosum, medial lemniscus, cerebral peduncles, spinal trigeminal tract, and funiculi of the spinal cord. In the majority of neurons and in glia, Type I-ir showed a diffusely nuclear and cytoplasmic location, Long-term adrenalectomy reduced immunoreactivity in most neurons and glia. Neuronal Type I-ir was localized mainly in the cytoplasm after long-term adrenalectomy. Nuclear immunoreactivity was retained in some neurons in the globus pallidus, motor trigeminal nucleus, and laminae 8 and 9 of the spinal cord. Acute treatment with corticosterone or aldosterone restored neuronal and glial Type I-ir to densities below that seen in intact rats.

Finite-element model of the human head: scalp potentials due to dipole sources

Abstract: Three-dimensional finite-element models provide a method to study the relationship between human scalp potentials and neural current sources inside the brain. A new formulation of dipole-like current sources is developed here. Finite-element analyses based on this formulation are carried out for both a three-concentric-spheres model and a human-head model. Differences in calculated scalp potentials between these two models are studied in the context of the forward and inverse problems in EEG. The effects of the eye orbit structure on surface potential distribution are also studied.

Effect of urea fertilizer and environmental factors on CH4 emissions from a Louisiana, USA rice field

Abstract: Methane emissions from a flooded Louisiana, USA, rice field were measured over the first cropgrowing season. Microplots contained the semidwarf Lemont rice cultivar drill seeded into a Crowley silt loam soil (Typic Albaqualfs). Urea fertilizer was applied preflood at rates of 0, 100, 200 and 300 kg N ha−1. Emissions of CH4 from the plots to the atmosphere were measured over a 86-d sampling period until harvest. Methane samples were collected in the morning hours (07∶30–09∶30) using a closed-chamber technique. Emissions of CH4 were highly variable over the first cropping season and a significant urea fertilizer effect was observed. Two peak CH4 emission periods were observed and occurred about 11 d after panicle differentiation and during the ripening stages. Maximum CH4 emmissions from the 0, 100, 200 and 300 urea-N treatments were 6.0, 8.9, 9.8 and 11.2 kg CH4 ha−1 d−1, respectively. These flux measurements corresponded to approximately 210, 300, 310 and 360 kg CH4 evolved ha−1 over the 86-d sampling period for the 4 treatments.

Misoprostol Compared with Sucralfate in the Prevention of Nonsteroidal Anti-inflammatory Drug-induced Gastric Ulcer: A Randomized, Controlled Trial

Abstract: Objectives To compare the efficacy and frequency of adverse experiences of misoprostol and sucralfate in the prevention of gastric ulcers in patients receiving nonsteroidal anti-inflammatory drug (NSAID) therapy. Design A prospective, randomized, single-blind, multicenter trial. Patients Patients with osteoarthritis receiving treatment with ibuprofen, piroxicam, or naproxen and experiencing abdominal pain were eligible. Interventions Patients who were expected to receive at least 3 months of NSAID therapy and who did not have a gastric ulcer at the time of the initial screening endoscopy were randomized to receive misoprostol, 200 micrograms four times a day, or sucralfate, 1 g four times a day. A gastric ulcer was defined as a lesion of the gastric mucosa 0.3 cm or greater in diameter. Patients were followed clinically, and repeat endoscopies were performed after 4, 8, and 12 weeks. Main measurement The development of a gastric ulcer, which was regarded as a prophylaxis failure. Results Two hundred fifty-three patients were evaluable for efficacy analysis. A gastric ulcer developed in 2 of the 122 (1.6%, 95% CI, 0.3% to 6.4%) patients on misoprostol, compared with 21 of 131 patients on sucralfate (16%, CI, 10.4% to 23.7%). The difference in ulcer rates was 14.4% (CI, 10.4% to 19.5%; P less than 0.001). Conclusion In patients receiving chronic NSAID therapy for osteoarthritis, treatment with misoprostol for 3 months was associated with a significantly lower frequency of gastric ulcer formation, compared with treatment with sucralfate (P less than 0.001).

Neuropeptide Regulation of Interleukin-6 Production from the Pituitary: Stimulation by Pituitary Adenylate Cyclase Activating Polypeptide and Calcitonin Gene-Related Peptide*

Abstract: Interleukin 6 (IL-6) production was shown to be stimulated by vasoactive intestinal peptide via cAMP dependent signal transduction pathway in the pituitary. We were interested in whether other hypothalamic neuropeptides, which activate adenylate cyclase in the pituitary, also stimulate pituitary IL-6 production. Whereas vasoactive intestinal peptide was effective in stimulating pituitary IL-6 production only at concentrations of 10-6 M or higher, pituitary adenylate cyclase activating polypeptide with 38 residues (PACAP38) and calcitonin gene-related peptide (CGRP) at concentrations from 10-10 to 10-9 M significantly stimulated IL-6 production. Similar effective concentrations of each peptide were required for activating adenylate cyclase, as measured by extracellular cAMP accumulation. H89, a specific inhibitor of cAMP dependent protein kinase (protein kinase A), inhibited IL-6 production stimulated by PACAP38, CGRP, and (Bu)2cAMP. However, H89 failed to inhibit the IL-6 production stimulated by lipopoly...

Asbestosis as a precursor of asbestos related lung cancer: results of a prospective mortality study

Abstract: A prospective mortality study of 839 men employed in the manufacture of asbestos cement products in 1969 examined lung cancer risk in relation to lung fibrosis seen on chest x ray film, controlling for age, smoking, and exposure to asbestos. Twenty or more years after hire, no excess of lung cancer was found among workers without radiographically detectable lung fibrosis, even among long term workers (greater than or equal to 21.5 years); nor was there a trend in risk by level of cumulative exposure to asbestos among such workers. By contrast, employees with small opacities (greater than or equal to 1/0; ILO classification) experienced a significantly raised risk of lung cancer (nine observed deaths v 2.1 expected), even though their exposures to asbestos were similar to the exposures of long term workers without opacities. In this population, excess risk of lung cancer was restricted to workers with x ray film evidence of asbestosis, a finding consistent with the view that asbestos is a lung carcinogen because of its fibrogenicity.

The effects of procedures, social accounts, and benefits level on victims' layoff reactions.

Abstract: Three hundred and fifty-three layoff victims responded to questions describing their reactions to layoffs Victims also described management layoff practices Two measures of procedural fairness in layoff practices (decision-making characteristics and social accounts) and one measure of layoff outcomes (benefits level) were included Only decision-making characteristics predicted exemployee willingness to recruit for a former employer and desire for regulation of layoffs These results provide further evidence of the importance of procedural justice in organizational decision-making

Political Institutions and Fiscal Policy: Evidence from the U.S. Historical Record

Abstract: No abstract is available for this paper.

Post-rolandic cortical projections of the superior temporal sulcus in the rhesus monkey.

Abstract: The efferent connections of different cytoarchitectonic areas of the superior temporal sulcus (STS) in the rhesus monkey with parieto-temporo-occipital cortex were investigated using autoradiographic methods. Four rostral-to-caudal subdivisions of cortex (area TPO) in the upper bank of the STS have distinct projection patterns. Rostral sectors (areas TPO-1 and -2) project to the rostral superior temporal gyrus (areas Ts1, Ts2, and Ts3), insula of the Sylvian fissure, and parahippocampal gyrus (perirhinal and prorhinal cortexes, areas TF, TH, and TL); caudal sectors (TPO-3 and -4) project to the caudal superior temporal gyrus (areas paAlt and Tpt), supratemporal plane (area paAc), circular sulcus of the Sylvian fissure (area reIt), as well as medial paralimbic (areas 23, 24, and retrosplenial cortex) and extrastriate (areas 18 and 19) cortexes. Area TPO-1 does not project to the parietal lobe; area TPO-2 projects to the inferior parietal lobule; area TPO-3 to the lower bank of the intraparietal sulcus (IPS) (area POa); and area TPO-4 to medial parietal cortex (area PGm). Vision-related cortex (area TEa) in the rostral lower bank of the STS sends fibers to the rostral inferotemporal region (areas TE1, -2, and -3) and parahippocampal gyrus (perirhinal cortex, areas TF and TL). Visual zones in the caudal lower bank and depth of the sulcus (area OAa, or MT and FST) project to the caudal inferotemporal region (areas TE3 and TEO), lateral preoccipital region (area V4), and lower bank of the IPS (area POa). A zone in the rostral depth of the STS (area IPa) projects to the rostral inferotemporal region, parahippocampal gyrus, insula of the Sylvian fissure, parietal operculum, and lower rim of the IPS (area PG). STS projections to parieto-temporo-occipital cortex have "feedforward," "feedbackward," and "side-to-side" laminar patterns of termination similar to those of other cortical sensory systems. The differential connectivity supports the cytoarchitectonic parcellation of the STS and suggests functional heterogeneity.

External fixation of distal radial fractures: results and complications.

Abstract: External fixation of unstable fractures of the distal radius yields satisfactory results but has a high complication rate. We studied thirty-five fractures in thirty-four patients to determine whether the results obtained with external fixation warranted it use. At a mean follow-up period of 31 months, the results of treatment were assessed by interviews and clinical and radiographic examination of both wrists. Twelve fractures had an excellent result, twelve had a good result, ten had a fair result, and one had a poor result. Radiographic results were graded excellent in ten fractures, good in thirteen, fair in five, and poor in seven. No correlation was found between the anatomical results and the clinical results or the patients' subjective ratings. Complications that were related directly to the fixation pins occurred in fourteen of the fractures. There were forty-five additional complications. The frequency of complications and the limitations of external fixation demand caution on the part of the surgeon to prevent iatrogenic morbidity, which would limit the benefits of the technique.