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Fluid Catalytic Cracking (FCC) technology is the most important process used by the refinery industry to convert crude oil to valuable lighter products such as gasoline. Process development is generally very time consuming especially when a small pilot unit is being scaled-up to a large commercial unit because of the lack of information to aide in the design of scaled-up units. Such information can now be obtained by analysis based on the pilot scale measurements and computer simulation that includes controlling physics of the FCC system. A Computational fluid dynamic (CFD) code, ICRKFLO, has been developed at Argonne National Laboratory (ANL) and has been successfully applied to the simulation of catalytic petroleum cracking risers. It employs hybrid hydrodynamic-chemical kinetic coupling techniques, enabling the analysis of an FCC unit with complex chemical reaction sets containing tens or hundreds of subspecies. The code has been continuously validated based on pilot-scale experimental data. It is now being used to investigate the effects of scaled-up FCC units. Among FCC operating conditions, the feed injection conditions are found to have a strong impact on the product yields of scaled-up FCC units. The feed injection conditions appear to affect flow and heat transfer patterns and the interaction of hydrodynamics and cracking kinetics causes the product yields to change accordingly.

Cocaine has wide-ranging effects on the immune and neuroendocrine systems (Fiala et al., 1996) resembling an inflammatory "stress" response with upregulation of pro-inflammatory cytokines and stimulation of the HPA axis (Gan et al., 1997). Cocaine abuse has also been associated with vascular pathology, including vasculitis, vasospasm and hemorrhage. These effects suggest that cocaine could perturb the function of endothelial cells, including the blood-brain barrier, and influence the progression to AIDS in HIV-infected individuals (Shapshak et al., 1997; Goodkin et al., 1997). In order to understand clinical consequences of cocaine abuse, it is important to gain insight into molecular and cellular basis of cocaine's effects on immune and endothelial cells. Cocaine's in vitro effects on (a) permeability, (b) immune cell migration, (c) adhesion molecules, and (d) cytokine expression were investigated in a blood-brain barrier model constructed with brain microvascular endothelial cells and fetal astrocytes with the following results: (a) cocaine and tumor necrosis factor-alpha (TNF-alpha) increased the model's permeability to inulin similarly in a dose-responsive fashion; (b) cocaine (10(-4) to 10(-8_ M) enhanced monocyte migration across the barrier with the maximum increase, approximately 100%, by 10(-5) M cocaine; (c) cocaine treatment also increased the expression of endothelial adhesion molecules, intercellular adhesion molecule-1 (ICAM-1), vascular cell adhesion molecules-1 (VCAM-1) and platelet/endothelial cell adhesion molecule-1 (PECAM-1); (d) although the cocaine in vitro effects on cytokine production by mononuclear cells have been difficult to assess due to a heterogeneity in the degree of responsiveness between individuals, the data suggest that mononuclear cells from cocaine addicts are sensitized to in vitro cocaine challenge with hypersecretion of inflammatory cytokines. Cocaine's in vivo manifestations are compatible with these in vitro effects: (A) chronic cocaine treatment of rats significantly increased rolling white blood cell flux, leukocyte-endothelium adhesion, and ICAM-1 expression in the mesentery (House et al., 1996); (B) cocaine injection to cocaine-dependent subjects tipped the balance of cytokine secretion by mononuclear cells to Th1-type (Gan et al., 1997), and (C) cocaine injection stimulated the hypothalamic-pituitary axis (HPA) to increase both anti- and pro-inflammatory hormonal secretion. Collectively, these results suggest that the immune effects of cocaine on endothelial, immune and neuroendocrine cells impair the function of the blood-brain, barrier, increase cell emigration from the blood vessels, in particular into the brain, and may cause vasculitis. These effects could also increase importation of HIV-1 into the brain.

The findings presented here clearly indicate an association between opioid- and cytokine-dependent systems. Exposure to exogenous opioids can produce profound effects on IL-1-mediated immune responses. Chronic exposure to morphine appears to disrupt the brain-immune axis by desensitizing the IL-1 activation of the HPA axis, and consequently potentiate the LEA response to IL-1. On the other hand, endogeneous IL-1, secreted in response to disease or stress, may alter the endogenous opioid pathway by inducing the expression of opioid receptors in endothelial cells. Clinically, the potential impact on the body's defense mechanisms resulting from the interaction between opioids, such as morphine, and cytokines, such as IL-1, can be substantial. Further investigation of this interaction is essential to understanding the extent of damage in human body caused by drugs of abuse, such as morphine.

The function of the urinary bladder is to store urine at low pressure and expel it periodically. To accomplish this, it must have the appropriate structural properties to accommodate slow but continuous volume changes. While much is presently known about the functional measurements of compliance, relatively little is known about the structural basis of compliance. In the present study, immunohistochemistry has been used to localize type III collagen fibers in the bladder wall at different intravesical volumes. To improve the resolution of these fibers, confocal microscopy was utilized to determine the changes in type III collagen fiber orientation and correlate them with the degree of mechanical distension of the bladder wall at partial and full capacity. We demonstrate that there were significant changes in both the orientation and conformation of type III collagen fibers during bladder filling. These observations support the view that volume accommodation in the bladder is achieved by changes in the arrangement of type III collagen. These data suggest that abnormal deposition or arrangement of type III collagen fibers can have an impact on normal bladder function.

A hybrid technique to couple hydrodynamics and chemical kinetics calculations in a multi-phase, multi-species, turbulent reacting flow simulation has been developed. It divides a flow simulation into two parts: a reacting flow hydrodynamic simulation with a small but sufficient number of lumped reactions to compute flow field properties followed by a many subspecies (of order 10 to 100) reaction kinetics and transport calculation. This technique has been incorporated in a computational fluid dynamics (CFD) code to predict concentrations of many subspecies in a reacting flow where complex chemical reactions take place, and it can be applied to many applications such as combustors. The application presented in this paper is the flow simulation of a fluid catalytic cracking (FCC) riser reactor. Applying the technique in the FCC riser application has shown that it can be used to identify critical processes and operating parameters including the trends and relationships that are necessary to the improve the quality and quantity of FCC products.

Inflammatory fibroid polyp of jejunum is a very rare nonneoplastic lesion of gastrointestinal tract. We reported a 66-year-old male who presented with abdominal fullness, colicky pain, and vomiting for 4 days. Plain abdomen showed intestinal obstruction with dilated small bowel loops. The exploratory laparotomy was performed under the clinical impression of intussusception caused by small bowel tumor. The diagnosis of an inflammatory fibroid polyp causing jejunojejunal intussusception was confirmed after surgery.

The TPS-05A beamline is the first X-ray beamline at NSRRC built for micro protein crystallography experiment as well as one of the seven ID beamlines in phase I at the TPS synchrotron facility. A 2-meter in-vacuum undulator (IU22) serves as the photon source from which the harmonics #3 to #9 will provide brilliance of 1018−1020 photons s−1 mrad−2 mm−2 (0.1% bandwidth)−1 and photon flux of 1013−1014 photons s−1 (0.1% bandwidth)−1 in the required energy range of 5.7−20 keV (2.175−0.620 A) to cover MAD phasing experiments at 1 A and SAD phasing experiments at 2 A. The beamline optics consists of a cryo-cooled double crystal monochromator (DCM) and a pair of focusing K-B mirrors. Requirements from the user group include a target focus size of 50 μm × 50 μm (H × V) at the sample position, photon flux greater than 2 × 1012 photons s−1 at Se K-edge (0.9795 A), pinholes for adjusting the beam size down to 5 μm. Calculation of heat load for the first optical element, i.e. the first crystal of DCM, is included in this paper.

This study compares the sensitivity of 99mTc-dimercaptosuccinic acid (DMSA) renal SPECT with planar scintigraphy, concluding the importance of 99mTc-DMSA renal SPECT for the early diagnosis of acute pyelonephritis (APN) in patients under 3 yr of age.Twenty-seven children under 3 yr of age, with clinical and/or laboratory suspicion of APN, were investigated. All 99mTc-DMSA renal SPECT and planar images and voiding cystoureterogram (VCUG) were obtained within 3 days of hospitalization.In the first examination, renal cortical defects were detected in 23 patients (42 kidneys) with SPECT and in 9 patients (11 kidneys) with planar scintigraphy. One year after treatment, constant renal cortical lesions were observed in 11 patients (14 kidneys) with SPECT and 4 patients (4 kidneys) with planar scintigraphy. The high grades of vesicoureteral reflux (VUR) (gradeor= 3) correlate better with APN diagnosed by SPECT (34 kidneys) than by planar scintigraphy (8 kidneys). Multiple renal cortical defects (number of lesionsor= 4) were only seen in patients under 1.5 yr old and none of those with a negative 99mTc-DMSA renal SPECT had a positive 99mTc-DMSA renal planar scintigraphy at any time. There is a significant difference (p0.05) between the diagnostic ability of these two methods of examination.Our results suggest that 99mTc-DMSA renal SPECT should be used, where possible, instead of planar DMSA in routine examination of children with clinical suspicion of APN, especially for those under 3 yr of age.

We present results of a scanning tunneling microscope (STM) study of Rh/Ag(100) epitaxy, which shows how the surface rearranges toward the more stable encapsulated structure known to form at higher temperatures. At room temperature, Rh growth proceeds via two competing pathways: (i) thermally activated exchange with Ag surface atoms, which leads to increased coordination of the higher surface free-energy metal Rh by Ag atoms, and (ii) nucleation and growth of mixed Rh/Ag adislands. The Ag-Rh interaction also reduces the surface mobility of Ag, e.g., by local pinning of step edges, accompanied by complex step and surface erosion processes. \textcopyright{} 1996 The American Physical Society.

Background Numerous studies have demonstrated the ability of angiotensin II (Ang II) receptor antagonists and angiotensin-converting enzyme (ACE) inhibitors to inhibit intimal hyperplasia after balloon dilatation of noncoronary arteries in small-animal models, suggesting an important role for Ang II in the response to injury. Although ACE inhibitors have not been similarly effective in nonhuman coronary models or in human restenosis trials, questions remain regarding the efficacy of ACE inhibitors against tissue ACE and the contributions of ACE-independent pathways of Ang II generation. Unlike ACE inhibitors, Ang II receptor antagonists have the potential to inhibit responses to Ang II independent of its biosynthetic origin. Methods and Results In separate studies, three Ang II receptor antagonists, including AT 1 -selective (L-158,809), balanced AT 1 /AT 2 (L-163,082), and AT 2 -selective (L-164,282) agents, were evaluated for their ability to inhibit vascular intimal thickening in a porcine coronary artery model of vascular injury. Preliminary studies in a rat carotid artery model revealed that constant infusion of L-158,809 (0.3 or 1.0 mg·kg −1 ·d −1 ) reduced the neointimal cross-sectional area by up to 37% measured 14 days after balloon dilatation. In the porcine studies, animals were treated with vehicle or test compound beginning 2 days before and extending 28 days after experimental angioplasty. Left anterior descending, left circumflex, and/or right coronary arteries were injured by inflation of commercially available angioplasty balloons with placement of coiled metallic stents. Infusion of L-158,809 (1 mg·kg −1 ·d −1 ), L-163,082 (1 mg·kg −1 ·d −1 ), or L-164,282 (1.5 mg·kg −1 ·d −1 ) in the study animals yielded plasma drug levels sufficient either to chronically block or, for L-164,282, to spare pressor responses to exogenous Ang II. Neither L-158,809, L-163,082, nor L-164,282 had statistically significant effects ( P =.12, P =.75, and P =.48, respectively, compared with vehicle-treated controls) on neointimal thickness (normalized for degree of injury) measured by morphometric analysis at day 28 after angioplasty. Conclusions These findings indicate that chronic blockade of Ang II receptors by either site-selective or balanced AT 1 /AT 2 antagonists is insufficient to inhibit intimal hyperplasia after experimental coronary vascular injury in the pig. The results further suggest that, unlike in the rat carotid artery, Ang II is not a major mediator of intimal thickening in the pig coronary artery.

Interleukin-1 beta (IL-1 beta) is a key mediator of immunological and pathological responses to stress, injury and disease and it has been suggested to have profound effects on neuroendocrine-immune functions. We have shown that central treatment with IL-I beta induces the expression of FOS proto-oncogene protein immunoreactivity (FOS-IR) in several hypothalamic nuclei including the paraventricular nucleus (PVN). Since FOS expression has been used as an anatomical marker of neuronal function, these results suggested that the involvement of IL-1 beta in the neuro-endocrine-immune axis may be mediated through the PVN. Treatment with several substances of abuse has been shown to modify immune function in vivo and in vitro. In this study, we compared the effects of morphine, ethanol and cocaine on IL-1 beta induction of FOS-IR in the rat hypothalamus. Acute treatment with morphine or ethanol induced FOS-IR in several nuclei including the PVN. Cocaine, which induced FOS-IR in the Caudate-Putamen (CPU), nucleus Accumbens (nAcc) and Locus Coeruleus (LC), however, did not induce FOS-IR in the PVN. Chronic treatment with morphine desensitized FOS responsiveness to morphine and IL-1 beta in the PVN since FOS-IR was no longer induced by IL-1 beta or morphine in the PVN after this treatment. Similarly, chronic ethanol treatment desensitized FOS responsiveness to ethanol and to IL-1 beta in the PVN. By contrast, chronic cocaine did not affect FOS responsiveness to IL-1 beta in the PVN even though the treatment was able to desensitize the FOS responsiveness to acute cocaine in the CPU, nAcc, and LC. These results suggest that the PVN may be a site where actions of IL-1 beta converge with those of morphine and ethanol, but not cocaine, to modulate neuro-endocrine-immune functions.

Angiotensin II (AII), the endogenous peptide ligand of the AII receptor, has equivalent high affinity for both the AT1 and AT2 receptor subtypes while most of the reported nonpeptide AII antagonists are AT1-selective. In an effort to identify dual AT1/AT2 nonpeptide AII antagonists, we have pursued modifications of previously prepared trisubstituted 1,2,4-triazolinone biphenylsulfonamides which exhibited subnanomolar in vitro AT1 (rabbit aorta) AII antagonism and AT2 (rat midbrain) IC50 values of40 nM. Present results show that a suitable amide (or reversed amide) side chain appropriately positioned on the N2-aryl group of these compounds gave15-fold enhancement in AT2 binding affinity without sacrificing nanomolar AT1 potency (IC50). This added amide, combined with an appropriate choice of the N-substituent on the sulfonamide and the ortho substituent on the N2-aryl group, led to an analogue (46, L-163,-007) which exhibited subnanomolar AT1 binding affinity and an AT2/AT1 IC50 ratio of 3. This compound showed excellent iv activity at 1 mg/kg and oral efficacy at 3 mg/kg with6 h duration in a conscious rat model. Available data suggest that the newly introduced amide side chain, mandatory for low nanomolar binding affinity at the AT2 receptor, is well-tolerated by the AT1 receptor and has minimal effect on the in vivo properties of these molecules.

Mu and delta opiate receptor regulation by opiate agonists and antagonists was studied in the human neuroblastoma cell line SH-SY5Y. Morphine down-regulated both mu and delta receptors, but its effects on each subtype could be dissociated by use of specific antagonists. The selective mu antagonist D-Phe-Cys-Tyr-D-Trp-Arg-Pen-Thr-NH2 (CTAP) blocked the down-regulation of mu, but not delta receptors. Conversely, the delta antagonist (N,N-diallyl-Tyr-Aib-Aib-Phe-Leu-OH([N,N-diallyl-Tyr1, Aib2,3]Leu- enkephalin)] ICI 174,864 blocked morphine-induced down-regulation of delta but not mu receptors. These selective antagonists also were studied alone for their effects on both receptors. CTAP alone at doses of 0.1 microM and higher up-regulated mu receptors. CTAP did not affect delta receptors at 0.3 microM or less, but it down-regulated them at doses of 1 microM or more, apparently due to its delta agonist activity at higher doses, which was reversed by ICI 174,864. ICI 174,864 alone also showed complex effects on the two subtypes, up-regulating both mu and delta sites. Its effects were most selective at a low dose (0.1 microM), which upregulated delta sites with minimal effects on mu sites. The nonselective antagonist naloxone provided a more robust upregulation (40%) of both mu and delta receptors than either selective antagonist alone or in combination. The mu-to-delta ratio (1.4 to 1) was not altered by differentiation of the cells with retinoic acid, which up-regulated both mu and delta receptors. Differentiation with the phorbol agent 12-O-tetradecanoyl-phorbol-13-acetate, however, up-regulated mu, but not delta receptors. The selective mu agonist Tyr-Pro-MePhe-D-Pro-NH2 (PL017) down-regulated mu receptors with a half-maximal effect at 180 nM, but was without effect on delta receptors at concentrations up to 10 microM. Conversely, the selective delta agonist Tyr-D-Pen-Gly-Phe-D-Pen([D-Pen2,5]-enkephalin) (DPDPE) potently down-regulated delta receptors, producing half-maximal decreases at 0.5 nM. At doses above those that reduced the maximum binding of [3H]pCl-DPDPE binding to the delta site, DPDPE also induced an apparent loss of affinity (increased Kd) at the delta site. It was without effect on mu receptors, however, at doses up to 10 microM. Thus, down-regulation of mu and delta receptors was homologous, because selective agonists down-regulated their respective receptors without effect on the heterologous opiate receptor.(ABSTRACT TRUNCATED AT 400 WORDS)

Scanning tunneling microscopy has shown that large, two-dimensional Ag clusters undergo observable diffusion on Ag(100). The variation of the diffusion coefficient with cluster size in the range studied, 100 to 540 atoms per cluster, indicates that two-dimensional evaporation-condensation is the main mechanism of cluster diffusion. The experimental data consistently show evidence for a backward-correlation in the cluster motion. The meaning and origin of this correlation is discussed.

Patellofemoral problems are common complications after total knee replacement. In order to investigate the effect of an increase in the patellar thickness on the kinematics of the knee joint, four intact embalmed cadaveric knee specimens were prepared to control the thickness of the patella and to measure: 1) the excursion lengths of the quadriceps muscles during knee flexion using a linear voltage displacement transducer; 2) patellar tracking and patellofemoral contact pressure using pressure sensitive Fuji prescale film; and 3) patellar movement during knee flexion using an image processing system. As the patellar thickness increased from the original dimension to a 7-mm increment, the excursion lengths of the quadriceps muscle during knee flexion did not vary significantly, but lateral patellar subluxation was clearly demonstrated by an increase in the patellofemoral contact pressure on the lateral femoral condyle and by lateral displacement of the patella. Increased patellar thickness in a total knee replacement is considered to be one of the causes of lateral subluxation. The importance of monitoring the patellar thickness using a patellar cutting jig is stressed.

The human neuroblastoma cell line SH-SY5Y was used to demonstrate morphine-induced down-regulation and naloxone-induced up-regulation of opiate receptors in a mu receptor containing neuronally derived preparation capable of desensitization to morphine. Chronic exposure to morphine decreased the number but not the affinity of mu opiate receptors in SH-SY5Y cells. Differentiation of the cells with retinoic acid or with the phorbol agent TPA (12-O-tetradecanoyl-phorbol-13-acetate) increased the number of mu receptors. Morphine-induced down-regulation, however, was observed in the absence of differentiation as well as after differentiation with retinoic acid or TPA. The decrease in the number of receptors was related to time of exposure, with a half-maximum disappearance time (T1/2) of about 3 hr during the initial phase. The receptor decrease was near maximum at 24 hr with no further significant change up to 72 hr. The loss of [3H] DAMGO ([3H]Tyr-D-Ala-Gly-N-Me-Phe-Gly-ol) binding was also dose-dependent, with reductions occurring at 0.3, 1 and 10 microM. The loss of receptors was dependent on temperature, with reductions at 37 but not 23 degrees C. The down-regulation was blocked by naloxone and the mu-selective antagonist CTOP (D-Phe-Cys-Tyr-D(-Trp-)Orn-Thr-Pen-Thr-NH2), but not by the delta antagonist ICI 174864 ([N,N-diallyl-Tyr1,Aib2,3]Leu-enkephalin). Cholinergic ([3H]quinclidinyl benzilate) binding was not affected by the morphine treatment, indicating that the down-regulation was homologous for opiate receptors. In SH-SY5Y cells, unlike other cell models, the opiate antagonist naloxone upregulated mu receptors by more than 50%.(ABSTRACT TRUNCATED AT 250 WORDS)

By a variety of synthetic routes, we have synthesized a series of 3,4,5-trisubstituted 4H-1,2,4-triazoles and a related series of 3H-imidazo[1,2-b][1,2,4]triazoles and evaluated them in vitro and in vivo as angiotensin II (AII) antagonists. Principal efforts focused on triazoles bearing an n-alkyl substitutent at C3 and a 4-[(2-carboxybenzoyl)amino]benzyl, (2'-carboxybiphenyl-4-yl)methyl, or [2'-(1H-tetrazol-5-yl)biphenyl-4-yl]methyl side chain at N4. Among numerous variations at C5, benzylthio groups gave the best potency. Particularly noteworthy was 3-n-butyl-5-[(2-carboxybenzyl)thio]-4-[[2'-(1H-tetrazol-5-yl )biphenyl-4 - yl]methyl]-4H-1,2,4-triazole (71, IC50 1.4 nM), which blocked the AII pressor response in conscious rats at 0.3 mg/kg iv with a duration of action of approximately 6 h, similar to that of DuP 753. Although 71 was active orally only at a 10-fold higher dose level, good oral bioavailability was demonstrated for a monoacidic analogue 62. Most potent among the bicyclic derivatives was 2-n-butyl-5,6-dimethyl-3-[[2'-(1H-tetrazol-5-yl)biphenyl-4-yl]meth yl]- 3H-imidazo[1,2-b][1,2,4]triazole (93, IC50 7.8 nM). The effects of hydrophobic, hydrogen-bonding, and ionic interactions with the AT1 receptor are considered.

The hemostatic effects of recombinant human erythropoietin (rHuEP) were investigated in 20 patients with end-stage renal disease (thirteen on hemodialysis, seven without dialysis) receiving this hormone. We studied their hemograms and coagulation profiles before and at 1 month after initiation of rHuEP therapy. One month after rHuEP administration, improvement in anemia (16/20, 80%) and shortening of bleeding time (17/19, 89.5%) were observed. Shortening or correction of bleeding time was achieved in three patients without any increase of the hemoglobin level. This means that factors other than the increased hematocrit level might contribute to shortening bleeding time in uremic patients receiving rHuEP treatment. The platelet count, prothrombin time, partial thromboplastin time, and fibrinogen level did not change over the course of rHuEP therapy. Thrombosis of vascular access was not observed, and heparin doses were not increased in this short-term period. A significant decrease was found in the plasminogen level, from 108.5% to 88.2% (p less than 0.05), in uremic patients on hemodialysis. The antithrombin III level also decreased, from 98.8% to 89.8% (p less than 0.05), and its level dropped to below normal ranges in six of thirteen patients (46%) on hemodialysis after treatment with rHuEP. No significant change was noted in the levels of antithrombin III, plasminogen, and alpha 2-antiplasmin in uremic patients not receiving dialysis. These results suggest that rHuEP administration induces increased extracorporeal dialyzer clotting and consumption coagulopathy, and that this extracorporeal consumption coagulopathy may play a role in the genesis of thrombotic complications.

The three-component microemulsion system, consisting of AOT/water(.6wt% NaCl) /decane, shows a typical 2¯φ-lφ-2φ progression at moderate surfactant weight fraction (γ=8%) when temperature of the system is raised through the hydrophile-lipophile balanced temperature. At low oil-water weight fraction (α=10%), it exhibits a structural inversion from L3-phase (water-in-oil microemulsions) at low temperatures to L1-phase (oil-in-water microemulsions) at high temperature through Lα-phase (lamellar microemulsions) in the intermediate temperatures within the one-phase channel. At equal oil-water volume fraction (α=40%), on the other hand, the inversion takes place through an intermediate disordered bicontinuous structure. We investigated these different inversion pathways for different α values using SANS intensity distributions. The thickness and polydispersity of surfactant bilayers in the L3 and Lα phases and surfactant monolayers in the bicontinuous phase are measured. In particular, the structural evolution as a function of α from the bicontinuous structure to the L3 structure has been explored.

Publisher Summary This chapter describes the radioligand binding assay methods used to identify and characterize the interaction of agents with the cholecystokinin-A (CCK-A) and CCK-B/gastrin receptor subtypes. The chapter also discusses the biochemical and pharmacological properties of nonpeptide CCK-A and CCK-B/gastrin antagonists, and their utility as radioligands. Rat pancreas and guinea pig cerebral cortex are frequently used as sources for CCK-A and CCK-B receptors, respectively. In a study described in the chapter, CCK-B/gastrin receptor antagonism was examined in vivo using the in situ perfused stomach preparation. The results of the study suggested that, as proposed for the cholinergic receptor or other receptor systems, the CCK-A receptor may have either two classes of binding sites or two conformational states that have different affinities for agonists but the same affinities for antagonists. The CCK receptor agonists, including CCK-8, CCK-8 desulfate, gastrin, and CCK-4, are also effective in inhibiting specific [ 3 H]L-365,260 binding to guinea pig brain membranes. Removal of MgCl 2 or addition of the guanyl nucleotide GppNHP results in a selective reduction of [ 125 I]CCK-8 binding and [ 3 H]L-365,260 binding differently.

In order to establish the normal values of bone mineral content (BMC) (g/cm2), the BMC of 140 healthy growing children including 49 girls (aged 5 to 16 years) and 91 boys (aged 7 to 17 years) was measured using Dual Photon absorptiometry (DPA) at L2-L4 level of the spine. The BMC increased significantly with age, after stratification by age. Both male and female children aged 7 to 10 years had similar BMC, but female children had significantly higher BMC at 12 to 13 years of age. We also established regression equations. Female: BMC = 0.38 + 0.021 x age. Male: BMC = 0.45 + 0.017 x age. They may be useful in estimating BMC in unknown individuals

Ultrasonography was performed on the thyroid glands of 47 patients with various thyroid diseases, in a fresh state, immediately following operation. The thyroid glands were then sectioned along the plane of the most significant sonographic changes. The pathologic changes of the sectioned plane were observed and compared with the sonographic changes. In nodular goiter, the sonographic changes were usually heterogeneous. The margin was either well-defined or ill-defined, and cystic changes might play a minor or major part in the thyroid nodules. In follicular adenoma, the changes were isoechoic in adenoma with embryonal type follicles and hyperechoic in adenoma with colloid type follicles. In adenoma of the oxyphilic cells, the echogenicity was somewhat greater in the hemorrhagic part compared to the area with oncocytic change only. In papillary carcinoma, the lesions usually manifested as well-limited, heterogeneous, hypoechoic nodules. Cystic degenerations were frequently noted. There were discrete particles corresponding to microcalcification in 4 out of 6 cases. In follicular carcinoma, the sonographic changes also showed well-limited nodules. However, the echogenicity was not decreased as much as in papillary carcinoma, and it could be either homogeneous and isoechoic, or hypoechoic. Relatively large particles with an acoustic sign, which corresponded to calcification, were noted in 2 out of 4 cases. In medullary carcinoma, the lesion was well-limited and hypoechoic. The particles present in sonography corresponded to calcification in the amyloid. In Graves' disease, the main sonographic change was a diffusely homogeneous, isoechoic or hypoechoic lesion. Cystic change was rarely present. Dispersed particles were rarely present and corresponded to fibrosis in the thyroid tissue.(ABSTRACT TRUNCATED AT 250 WORDS)

Novel aryl amide analogues of glutamic acid dialkylamide have been synthesized to test for a possible structural analogy between glutamic acid and benzodiazepine CCK antagonists such as compounds 2 and 24 (lorglumide and MK-329, respectively). In support of the structural model, certain of these hybrid compounds are more potent in pancreas CCK radioligand binding assays than corresponding lorglumide-type reference compounds. Modifications previously found in the benzodiazepine antagonists to result in brain CCK/gastrin receptor selectivity were also incorporated to produce an aryl urea series of glutamic acid analogues. None of these compounds were brain CCK/gastrin selective; however, one was potent and selective in the pancreas binding assay. The model appears to be most useful in the design of selective ligands for the pancreas type CCK receptor.

The nonlinear Wiener stochastic gradient adaptive algorithm for third-order Volterra system identification application with Gaussian input signals is presented. The complete self-orthogonalisation procedure is based on the delay-line structure of the nonlinear discrete Wiener model. The approach diagonalises the autocorrelation matrix of an adaptive filter input vector which dramatically reduces the eigenvalue spread and results in more rapid convergence speed. The relationship between the autocorrelation matrix and cross-correlation matrix of filter input vectors of both nonlinear Wiener and Volterra models is derived. The algorithm has a computational complexity of O(M/sup 3/) multiplications per sample input where M represents the length of memory for the system model, which is comparable to the existing algorithms. It is also worth noting that the proposed algorithm provides a general solution for the Volterra system identification application. Computer simulations are included to verify the theory.

Objectives/Hypothesis: Although numerous investigators have reported a bedside percutaneous dilatational tracheotomy (PDT) complication incidence similar to that of standard operative tracheostomy, others have proposed a learning curve for PDT resulting in increased complications early in individual or institutional experience with this procedure. The objective of this investigation is to characterize and quantify the proposed learning curve for PDT. Study Design: Prospective analysis of complication incidence for the first 100 PDT procedures performed in a local community hospital Department of General Surgery. Methods: Demographic data, patient disease variables, and patient anatomic features, as well as perioperative, postoperative, and late complications, were recorded prospectively. Patients were divided into sequential cohorts of 20 and were evaluated for complications at regular intervals. Results: Perioperative and late complication incidence was significantly higher in the first 20 patients who underwent PDT. However, postoperative complication incidence did not significantly vary with operator or institutional experience. In addition, patients with suboptimal anatomy were found to have a significantly increased complication incidence, independent of operator and institutional experience. Conclusions: Percutaneous dilational tracheotomy has an identifiable learning curve that is most prominent in the first 20 patients treated. Early experience with PDT should be obtained under controlled circumstances, ideally the operating suite. Although most complications occur during acquisition of early experience with PDT, certain life-threatening complications such as tube dislodgment or inability to complete procedure may occur even after extensive experience is obtained. Bedside PDT has an acceptable complication incidence, but any surgeon employing this technique must be prepared to perform immediate standard open tracheotomy to minimize potentially lethal complications of this elective procedure.

The adsorption characteristics of bismuth and antimony on III–V(110) substrates have been studied as a function of overlayer coverage and deposition conditions using low energy electron diffraction (LEED). We examine the different roles of chemical bonding and atomic size for determining surface ordering phenomena and epitaxy in these systems. LEED and Auger data were collected for monolayer range film thicknesses prepared on GaAs, InP, GaSb, InAs, and InSb substrates cleaved in situ. Both IV and diffraction spot profiles were measured. Our results indicate that significant differences exist between the structure and surface chemical bonding of antimony and bismuth to III–V materials which were not revealed from previous studies using GaAs alone.

[3H]Mepyramine binds with high affinity to membranes from brain of human, rat, guinea-pig, rabbit and mouse with drug specificity indicating an association with histamine H1receptors. Considerable species differences occur in the affinity of [3H]mepyramine, with guinea-pig and human having 34 times greater affinity than rat, mouse or rabbit. The greater affinity of [3H]mepyramine in guinea-pig than in rat is attributable both to faster association and slower dissociation rates in guinea-pig. Species differences in affinity for H1 receptor sites occur for some antihistamines but not for others. Some tricyclic antidepressant and neuroleptic drugs are extremely potent inhibitors of [3H]mepyramine binding, exceeding in potency any H1 antihistamines examined. The tricyclic antidepressant doxepin and the neuroleptic clozapine are the most potent of all drugs examined in competing for [3H]mepyramine binding. The regional distribution of specific [3H]mepyramine binding differs considerably in the various species examined.

Maximization of the natural frequencies of a cylindrical shell is treated herein by considering the lowest frequency corresponding to an axisymmetric mode. For a given volume of the shell, the inner radius is kept constant, while piecewise linear variation of the outer radius is allowed. Results indicate considerable elevation in the frequency. The problem of determining the minimum volume for a prescribed frequency is also treated and the study shows that a reasonable amount of saving in material is possible. A numerical procedure incorporating the complex optimization technique and the finite element method is used.

L'appareillage conventionnel de diffraction peut etre utilise pour observer les oscillations des intensites diffractees lors de la croissance de Pt sur Pd(100). Malgre la faible longueur de coherence, les profils sont constitues de deux composants bien separes: ordre a longue distance et l'ordre a courte distance