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  • 1990-1994  (17)
  • Life and Medical Sciences  (13)
  • Engineering  (2)
  • Metaiodobenzylguanidine  (2)
  • 1
    Electronic Resource
    Electronic Resource
    Predictors of toxicity in treating patients with neuroblastoma by radiolabeled metaiodobenzylguanidine (1994)
    Springer
    European journal of nuclear medicine 21 (1994), S. 46-52 
    Details
    ISSN: 1619-7089
    Keywords: Metaiodobenzylguanidine ; Therapy ; Toxicity ; Thrombocytopenia ; Dosimetry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract We searched for methods that would enable prescriptions of the maximum tolerable doses of iodine-131 metaiodobenzylguanidine (MIBG) and iodine-125 MIBG in the treatment of patients with neuroblastoma. We correlated doses, defined in different ways, with subsequent platelet levels in treated patients to determine accurate predictors of the most frequent toxicity, thrombocytopenia. Nine patients with neuroblastoma were given 131I-MIBG (4.9–8.1 GBq or 132–220 mCi) and ten were given 125I-MIBG (8.3-30.0 GBq or 224–809 mCi) as initial treatments. These therapies were sufficiently varied that correlations could be made between indices of the doses and the subsequent toxicity as reflected in circulating platelet levels. Predictors of toxicity were: whole-body absorbed dose of radiation (cGy) calculated from pretherapy tracer doses of 131I-MIBG; GBq/kg of body weight; and GBq/m2 of body surface area. Toxicity was recorded as the nadir of the platelet level and platelet/pretherapeutic level (platelet ratio). For treatments with 131I-MIBG, the highest correlation was obtained between cGy and the logo10-transformed platelet ratio (r=−0.86), but comparison of GBq/m2 and the platelet nadir (r=−0.76) or the platelet ratio (r=−0.74) or the log10 − transformed platelet ratio (r=−0.73) gave comparable and statistically significant results. For treatments with 125I-MIBG, significant correlations were obtained between GBq/m2 and the platelet ratio (r=−0.81) or GBq/kg and the log10 −-transformed platelet ratio; the correlation between cGy and any toxicity index was low. Per administered GBq, 131I-MIBG was 2.6 times more potent than 125I-MIBG in causing a platelet ratio of 0.1. Thus, in predicting toxicity, therapeutic doses of 131I-MIBG expressed as GBq/m2 performed satisfactorily and almost as well as whole-body cGy, and treatment doses of 125I-MIBG expressed as GBq/m2 or GBq/kg performed satisfactorily and much better than whole-body cGy.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00182305
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  • 2
    Electronic Resource
    Electronic Resource
    Phaeochromocytoma and functioning paraganglioma in childhood and adolescence: role of iodine 131 metaiodobenzylguanidine (1991)
    Springer
    European journal of nuclear medicine 18 (1991), S. 191-198 
    Details
    ISSN: 1619-7089
    Keywords: Phaeochromocytoma ; Paraganglioma ; childhood ; Adolescence ; Metaiodobenzylguanidine
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Phaeochromocytomas and functioning paragangliomas are rare tumours in childhood and adolescence. We review our experience of 43 cases (24 men, 19 women) who were first diagnosed at the age of ⩽ 18 years. All patients were evaluated at some point in their illness with iodine 131 metaiodobenzylguanidine (131I-mIBG) scintigraphy. Eight patients (19%) had bilateral adrenal tumours, 12 (28%) had solitary extra-adrenal tumours, and 8 (19%) had multiple tumours. In 10 patients (23%), the tumours were associated with a familial neurocristopathic syndrome. Thirteen of 24 (54%) unifocal tumours which were initially considered to be benign ultimately proved to be multi-focal and/or malignant. The final prevalence of malignancy was 60% − 26 patients, of whom only 15 (57%) had obviously malignant tumours at the time of diagnosis. Primary tumour size ⋝5 cm was more commonly associated with a malignant course in adrenal but not extra-adrenal tumours. No other clinical, biochemical or morphological characteristic was significantly associated with malignancy. Although the high prevalence of malignancy in this series at least partly reflects referral bias, the need for lifelong follow-up of these patients is underscored.131I-mIBG scintigraphy was positive in 36 patients (84%), with a somewhat lower false-negative rate (12%) than X-ray computed tomography (20%). Eight patients with malignant tumours received therapeutic doses of131I-mIBG, with partial tumour responses in 3. Thus,131I-mIBG is an efficacious, non-invasive, localising agent and may be considered as a palliative therapeutic agent when alternatives have failed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02262730
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  • 3
    Electronic Resource
    Electronic Resource
    Middle-ear development: II. Morphometric changes in the conducting apparatus of the chick (1992)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 212 (1992), S. 257-267 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The ontogeny of various middle-ear structures was examined in 11 groups of chicks between 10 days embryonic and adult. Measurements of the tympanic membrane surface area and height, columella length, and that of the columella footplate, annular ligament, and oval window area were obtained using video micrographs and computer digitization techniques. The oval window matures first at 53 days post-hatching, whereas the columella achieves adult size at 74 days. The tympanic membrane surface area is the last middle-ear variable studied to reach adult size (79 days post-hatch). The columella increases its length from 0.63 mm (10 days embryonic) to 2.73 mm in the adult. The tympanic membrane area expands by 280% whereas the columellar footplate area increases by 11x. As a result, the pressure amplification of the middle ear due to the tympanic membrane/columellar footplate area ratio improves by over 400%. These data further contribute to our understanding of the functional development of the middle ear. © 1992 Wiley-Liss, Inc.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jmor.1052120305
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  • 4
    Electronic Resource
    Electronic Resource
    Middle-ear development VI: Structural maturation of the rat conducting apparatus (1994)
    New York, NY [u.a.] : Wiley-Blackwell
    The @Anatomical Record 239 (1994), S. 475-484 
    Details
    ISSN: 0003-276X
    Keywords: Middle ear ; Auditory ; Hearing development ; Ossicles ; Tympanic membrane ; Rat (Long Evans strain) ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: Background: The contribution of middle-ear development to the overall development of hearing has not been explored in great detail. This presentation describes the maturation of conductive elements in the rat middle ear, and provides the basis on which future studies of middle-ear functional development will follow.Methods: The middle-ear apparatus was examined at nine different ages (between 1 and 80 days postpartum) in Long Evans rats. At each age elements of the conducting apparatus were observed with either light or scanning electron microscopy (SEM), and quantitative measurements were made from video enhanced photomicrographs. Tympanic membrane area and cone depth, the length of the malleus and incus arms, ossicular weight, stapes foot plate and oval window areas, and bulla volume were all measured. Development of the area and lever ratios were derived from these measurements. The data were fitted to exponential equations and the time in days required to reach 90% of the adult level determined.Results: The pars tensa achieved 90% of total area by 17 days. The oval window achieved the 90% criterion by 13 days, while the area ratio was within 10% of its adult size by 8 days. The ossicles took between 26 and 34 days, while bulla volume took 59 days to reach the 90% level.Conclusions: Middle-ear growth was very orderly and systematic in the data reported. When maturation of the area ratio was considered against development of the endocochlear potential or the round window compound action potential, it was clear that the growth of this important aspect of the middle ear preceded the onset of cochlear function. © 1994 Wiley-Liss, Inc.
    Additional Material: 12 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/ar.1092390413
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  • 5
    Electronic Resource
    Electronic Resource
    Immunohistochemical localization of atrial natriuretic peptide in the developing and adult mammalian kidney (1991)
    New York, NY [u.a.] : Wiley-Blackwell
    American Journal of Anatomy 190 (1991), S. 182-191 
    Details
    ISSN: 0002-9106
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: The discovery, within the last decade, of atrial natriuretic peptide (ANP), a family of peptides with natriuretic/diuretic and vasorelaxant properties, has prompted much research into the mechanisms and sites of action of ANP within the kidney. In the present study, ANP was localized in the kidneys of several mammalian species by immunohistochemical techniques (1) to identify possible sites of synthesis; (2) to compare the localization of ANP to known physiological effects; (3) to determine species differences, if any, in ANP localization; and (4) to study the development of ANP immunoreactivity in the fetal and neonatal rat kidney. Using an antibody against rat ANP IV, ANP was localized exclusively on the proximal convoluted tubule (PCT) brush border and within intercalated cells of the outer medullary and cortical collecting tubules and ducts of adult mouse, rat, pig, monkey, and human kidneys. The development of ANP immunoreactivity paralleled the differentiation and maturation of collecting duct epithelium in rat fetal kidney. Atrial natriuretic peptide found within intercalated cells of the cortical and outer medullary collecting ducts may be the result of endogenous synthesis and, following secretion, may be available to receptors in the inner medullary collecting ducts.
    Additional Material: 10 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/aja.1001900207
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  • 6
    Electronic Resource
    Electronic Resource
    The effect of pulsed microwaves on passive electrical properties and interspike intervals of snail neurons (1993)
    New York, NY [u.a.] : Wiley-Blackwell
    Bioelectromagnetics 14 (1993), S. 503-520 
    Details
    ISSN: 0197-8462
    Keywords: constant temperature ; intracellular recording ; time series ; regression analysis ; Life and Medical Sciences ; Occupational Health and Environmental Toxicology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Physics
    Notes: The effects of pulsed microwaves (2.45 GHz, 10 μs, 100 pps, SAR: 81.5 kW/kg peak, 81.5 W/kg average) on membrane input resistance and action potential (AP) interval statistics were studied in spontaneously active ganglion neurons of land snails (Helix aspersa), at strictly constant temperature (20.8±.07°C worst case). Statistical comparison with sham-irradiated neurons revealed a significant increase in the mean input resistance of neurons exposed to pulsed microwaves (P ≪ .05 ). Pulsed microwaves had no visible effect on mean AP firing rate; this observation was confirmed by analysis of interspike intervals (ISIs). Using an integrator model for spontaneously active neurons, we found the net input current to be more variable in neurons exposed to pulsed microwaves. The mean input current was not affected. The standard deviation of ISIs and the autocorrelation of the input current were marginally affected, but these changes were not consistent across neurons. Although the observed effects were less obvious than those reported in other studies, they represent evidence of a direct interaction between neurons and pulsed microwaves, in the absence of macroscopic temperature changes. The data do not suggest a single, specific mechanism for such interaction. © 1993 Wiley-Liss, Inc.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bem.2250140603
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  • 7
    Electronic Resource
    Electronic Resource
    State-space representation and optimal control of non-linear material deformation using the finite element method (1993)
    Chichester [u.a.] : Wiley-Blackwell
    International Journal for Numerical Methods in Engineering 36 (1993), S. 1967-1986 
    Details
    ISSN: 0029-5981
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Notes: A state-space model for representing the non-linear material deformation and an optimal control scheme for obtaining desired process conditions in the deforming material are presented in this paper. The formulation is general for various metal-forming processes including forging and extrusion operations. The state variables selected in the formulation are the die/billet contact nodal velocities and the nodal velocities of the critical finite elements of the billet. The control input is the ram velocity, which is determined by using the linear quadratic regulator (LQR) theory to maintain desired strain rates within the selected finite elements. The influence of an optimally designed ram velocity on the deforming material is studied using performance measures. This paper includes the development of the state-space model from non-linear finite element formulation, optimal control strategy and numerical example cases with discussions.
    Additional Material: 16 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/nme.1620361202
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  • 8
    Electronic Resource
    Electronic Resource
    Design of optimal process parameters for non-isothermal forging (1994)
    Chichester [u.a.] : Wiley-Blackwell
    International Journal for Numerical Methods in Engineering 37 (1994), S. 155-177 
    Details
    ISSN: 0029-5981
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Notes: This paper presents a state space model and an optimal design scheme for non-isothermal metal forming processes. By selecting nodal velocity and temperature as the state variables, a non-isothermal state equation with coupled deformation and thermal terms is established. Based on this state space model, a control design scheme is developed to obtain the optimal die velocity and initial die temperature which will ensure that the effective strain-rate and temperature satisfy the design requirements. A titanium alloy engine disk forging is used to demonstrate two design examples. The results show that the proposed model and design scheme behave well for different design requirements.
    Additional Material: 11 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/nme.1620370111
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  • 9
    Electronic Resource
    Electronic Resource
    Receptor-mediated autocrine growth-stimulatory effect of 5-hydroxytryptamine on cultured human pancreatic carcinoid cells (1992)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Cellular Physiology 150 (1992), S. 1-7 
    Details
    ISSN: 0021-9541
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: 5-hydroxytryptamine (5-HT) is a mitogen for fibroblasts, vascular smooth muscle cells, renal mesangial cells, and jejunal crypt cells. The human carcinoid cell line (termed BON) that we established in our laboratory from a pancreatic carcinoid tumor produces and secretes 5-HT. In this study, therefore, we examined the effect of 5-HT on growth of BON cells. Furthermore, by use of selective 5-HT receptor antagonists, we examined receptor and post-receptor mechanisms by which 5-HT-induced responses were produced. 5-HT stimulated growth of BON cells. 5-HT stimulated phosphatidylinositol (PI) hydrolysis in a dose-dependent fashion and inhibited cyclic AMP production in a dose-dependent fashion. The 5-HT1A/1B receptor antagonist, SDZ 21-009, prevented the reduction of cyclic AMP production evoked by 5-HT and inhibited the mitogenic action of 5-HT. The 5-HT1C/2 receptor antagonist, mesulergine, competitively inhibited PI hydrolysis, but did not affect the mitogenic action of 5-HT. The mitogenic action of 5-HT and the reduction of cyclic AMP production evoked by 5-HT were also inhibited by pertussis toxin. These results suggest that 5-HT is an autocrine growth factor for BON cells and that mitogenic mechanism of 5-HT involves receptor-mediated toxin-sensitive GTP binding protein. 8-bromo-cyclic AMP inhibited growth of BON cells whereas 8-bromo-cyclic GMP had no effect on cell growth. Involvement of protein kinase A in BON cell growth regulation was confirmed by the observation that a cAMP-dependent protein kinase antagonist (Rp-cAMPS) could stimulate BON cell growth.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jcp.1041500102
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  • 10
    Electronic Resource
    Electronic Resource
    Novel action of transforming growth factor β1 in functioning human pancreatic carcinoid cells (1993)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Cellular Physiology 156 (1993), S. 112-118 
    Details
    ISSN: 0021-9541
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: We have shown recently that 5-HT is an autocrine growth stimulatory factor for a cell line (BON) that is derived from a human pancreatic carcinoid tumor. This action is mediated by a 5-HT receptor-linked decrease of cyclic adenosine monophosphate (AMP) production, but not mediated by a 5-HT receptor-linked stimulation of phosphatidylinositol hydrolysis. The BON cells also express transforming growth factor betas (TGFβs) (1, 2, and 3) and release TGFβ into their medium. In this study, we examined the effects of TGFβ1 on the secretion of 5-HT, on signal transduction pathways involved in 5-HT secretion, and on growth of BON cells. TGFβ1 inhibited basal and acetylcholine-stimulated release of 5-HT, but did not inhibit isobutylmethylxanthine-stimulated release of 5-HT. TGFβ1 inhibited both basal and acetylcholine-stimulated hydrolysis of phosphatidylinositol in a dose-dependent manner, but did not affect cyclic AMP production. TGFβ1 inhibited growth of BON cells in culture; this effect was reversed by exogenously administered 5-HT. Three different specific and saturable TGFβ1 binding sites were identified; binding assays performed after mild acid wash (0.1% acetic acid, pH 2.5) conditions uncovered TGFβ receptors that were apparently occupied by endogenously produced TGFβ species. Affinity cross-linking assay showed that BON cells had three different TGFβ binding proteins. These results suggest that TGFβ1 can inhibit growth of BON cells by altering secretory responses of 5-HT by means of receptor-mediated inhibition of phosphatidylinositol hydrolysis. We conclude that growth of BON cells is regulated, at least in part, by the opposing receptor-mediated autocrine actions of 5-HT and TGFβ. © 1993 Wiley-Liss, Inc.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jcp.1041560116
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