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Szaro BG, Tompkins R. Effect of tetraploidy on dendritic branching in neurons and glial cells of the frog, Xenopus laevis. J Comp Neurol 1987; 258:304-16. [PMID: 3584543 DOI: 10.1002/cne.902580210] [Citation(s) in RCA: 28] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Morphological aspects of four different groups of Golgi impregnated brain cells from a tetraploid strain of Xenopus laevis frogs were compared to analogous cells in comparably sized diploid frogs. The cells examined included neurons from the telencephalon, caudal hypothalamus, and optic tectum, and radial glial cells from the optic tectum. The brains of tetraploid frogs appeared grossly normal and were the same size and contained similar cell types as diploid brains. As observed in previous studies on polyploid amphibia, somal diameters increased significantly in tetraploid cells for each of the four groups of cells examined. Also, the total length of the dendritic arbors in tetraploid brain cells increased significantly by factors ranging from 1.4 to 2.4 times the total length of the analogous processes in diploid cells. Tetraploid neurons in the telencephalon and hypothalamus increased their arbor lengths predominantly by increasing the number of dendritic branches, while maintaining the average distance between branch points in the dendritic segments. In contrast, the tetraploid large pear-shaped neurons in the optic tectum had significantly longer terminal dendritic segments than the analogous diploid neurons, although these tetraploid neurons maintained their average number of dendritic segments per cell. Tetraploid tectal radial glial cells appeared to increase both their number of branches and the lengths of their terminal segments. Thus, the mode by which tetraploid brain cells achieved longer dendritic arbors varied from cell type to cell type. These results suggest a hypothetical basis for possible effects of genomic size on vertebrate brain structure and evolution at the cellular level.
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Dudek FE, Ide CF, Tompkins R. Unresponsive, a behavioral mutant in Xenopus laevis: electrophysiological studies of the neuromuscular system. JOURNAL OF NEUROBIOLOGY 1987; 18:237-43. [PMID: 3572392 DOI: 10.1002/neu.480180208] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Normal Xenopus laevis embryos begin movements at 1 day after fertilization. Embryos homozygous for the unresponsive mutation fail to move until 4 days after fertilization (just prior to feeding), after which they recover slowly. Electrophysiological studies were undertaken to determine the focus of this mutation. Formamide treatment of normal embryos was used to produce a phenocopy of the unresponsive condition, permitting direct comparisons between mutant and normal embryos. Intracellular recordings from muscle cells were obtained in formamide-treated and untreated preparations with both normal and unresponsive animals. Local electrical stimulation evoked either isolated endplate potentials and action potentials or after-discharges of these events in all preparations. A decrease in illumination also caused a burst of endplate potentials and action potentials. Therefore, the electrophysiology of the neuromuscular junction in unresponsive appears qualitatively normal; the effect of the mutation on the motor system is probably distal to the neuromuscular junction, either at or subsequent to excitation-contraction coupling.
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28
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Reinschmidt D, Friedman J, Hauth J, Ratner E, Cohen M, Miller M, Krotoski D, Tompkins R. Gene-centromere mapping in Xenopus laevis. J Hered 1985; 76:345-7. [PMID: 4056365] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Gynogenesis was used to map eight loci to their centromeres in Xenopus laevis. Several loci remote from their centromeres were identified. This information may be useful in distinguishing gynogenetic diploid progeny produced by suppression of second polar bodies from gynogenetic diploid progeny homozygous at all loci produced by suppression of first cleavage of gynogenetic haploids.
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Szaro B, Ide C, Kaye C, Tompkins R. Regulation in the neural plate of Xenopus laevis demonstrated by genetic markers. THE JOURNAL OF EXPERIMENTAL ZOOLOGY 1985; 234:117-29. [PMID: 3989493 DOI: 10.1002/jez.1402340114] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
To follow the subsequent history of grafted tissue in experiments designed to study regulation and commitment in the amphibian neural plate, previous workers have relied on graft scars, vital dyes applied externally to cells, or xenoplastic grafts. Each of these methods has been criticized on the grounds that they do not indicate unambiguously the origins of individual cells within the operated host. To overcome these difficulties, homoplastic, genetically marked embryonic grafts were taken from the prospective spinal neuroectoderm of triploid and tetraploid Xenopus laevis frogs and transplanted to presumptive eye and prosencephalic regions of the neural plate of diploid X. laevis embryos. Orthotopic presumptive eye grafts also were done. Marked cells were scored in section either by nucleolar number or computerized nuclear size analysis. Of 28 heterotopically grafted embryos that survived to stage 41, when the retina has differentiated, prospective spinal cord neuroectoderm in eight animals gave rise to cell types unique to the eye. The remaining 20 survivors appeared to be mosaic. These results substantiate claims of regulation in the neural plate and extend these observations to the level of individual cell types, a level of resolution not previously obtained in other studies.
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Krotoski DM, Reinschmidt DC, Tompkins R. Developmental mutants isolated from wild-caught Xenopus laevis by gynogenesis and inbreeding. THE JOURNAL OF EXPERIMENTAL ZOOLOGY 1985; 233:443-9. [PMID: 3973558 DOI: 10.1002/jez.1402330313] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Xenopus laevis obtained from indigenous African populations are a rich source of mutants affecting development. Gynogenesis and inbreeding were used to isolate mutants affecting development from wild-caught Xenopus laevis females. Fourteen mutants were recovered from eight females tested. One mutant was recovered from each of two females. This load of 1.875 developmental mutants per female is similar to that found in the axolotl (Ambystoma mexicanum), a urodele amphibian, and is only slightly less than the load of mutants with major developmental effects found in Drosophila and man. These results suggest that the anuran amphibian Xenopus laevis, an ancestrally tetraploid species, has undergone extensive diploidization of developmentally important loci and that gynogenesis and inbreeding of wild-caught animals can provide adequate mutants at diploid loci for developmental genetic studies.
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Ide CF, Reynolds P, Tompkins R. Two healing patterns correlate with different adult neural connectivity patterns in regenerating embryonic Xenopus retina. THE JOURNAL OF EXPERIMENTAL ZOOLOGY 1984; 230:71-80. [PMID: 6726148 DOI: 10.1002/jez.1402300110] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
Nasal and temporal one-third-sized eye fragments, formed by ablation at stage 32-33 of Xenopus laevis embryos, heal and, in about 50% of the cases, survive to make eyes in the postmetamorphic animal which have mappable visuotectal projections. The majority of nasal one-third eyes have duplicate projections whereas the majority of temporal one-third eyes have unduplicated projections. Most nasal one-third eye fragments and a minority of temporal eye fragments heal by the extrusion of cells from the center of the cut edge into the region of the ablation, forming a tongue of cells between the distal cut edges. This healing pattern is correlated with duplicated visuotectal projections. Most temporal one-third fragments and a minority of nasal one-third fragments heal by rounding up; that is, the distal cut edges collapse to meet in the region of the ablation. This healing pattern is correlated with the formation of unduplicated visuotectal projections. During tongue formation, neurons and undifferentiated cells are transferred from the original fragment into the tongue in a disorderly array, but quickly re-form normal retinal order. We propose that the tongue cells retain their original determination to connect to the same tectal positions as the fragment from which they originated, despite their new positions, and that this mosaicism, coupled with cell movement into the tongue, established duplicate visuotectal projections.
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32
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Tompkins R, Szaro B, Reinschmidt D, Kaye C, Ide C. Effects of alterations of cell size and number on the structure and function of the Xenopus laevis nervous system. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 1984; 181:135-46. [PMID: 6532155 DOI: 10.1007/978-1-4684-4868-9_11] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
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33
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Dobrinska MR, Furst DE, Spiegel T, Vincek WC, Tompkins R, Duggan DE, Davies RO, Paulus HE. Biliary secretion of sulindac and metabolites in man. Biopharm Drug Dispos 1983; 4:347-58. [PMID: 6661513 DOI: 10.1002/bdd.2510040407] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
The biliary secretion of sulindac and metabolites after a single 400 mg oral dose of the drug was studied in 3 elective gallbladder surgical patients following placement of an occludable T-tube in the common bile duct. Bile and systemic plasma were sampled at frequent intervals for up to 36 h postdose. The apparent biliary clearance (Vcl,bile) of the prodrug sulindac is about 25 times greater than that of the pharmacologically active sulfide metabolite. The total biliary flux of drug in normal man with an uninterrupted enterohepatic cycle, calculated from Vcl,bile and historic mean plasma drug AUCinfinity0 values, averages 144 and 12.2 per cent of the dose as sulindac and the sulfide metabolite, respectively. Thus, enterohepatic recycling of the drug in man is principally in the form of the prodrug which not only limits exposure of the intestine to the active moiety but also sustains systemic concentrations of active drug upon reabsorption of the prodrug.
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34
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Kaye C, Schermer JA, Tompkins R. Tolerance maintenance depends on persistence of the tolerizing antigen: evidence from transplantation studies on Xenopus laevis. DEVELOPMENTAL AND COMPARATIVE IMMUNOLOGY 1983; 7:497-506. [PMID: 6357880 DOI: 10.1016/0145-305x(83)90034-4] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
In order to assess the role of antigen persistence in the tolerant state, tolerance was induced in Xenopus laevis by the embryonic transplantation of whole eyes or tail tissue. Both types of transplants were seen to heal in and persist, with no signs of immunological incompatibility. At metamorphosis, tail resorption occurred and grafted tail tissue was lost. Eye transplants were maintained through metamorphosis in most eye grafted animals. Eye graft recipients which had maintained the transplant were observed to accept challenge skin allografts from donors of the same genotype as the eye donor in all but one case, while recipients which had lost the eye transplant at metamorphosis or had the eye transplant experimentally removed sometimes did not accept the challenge skin graft. Animals tail grafted as embryos did not accept post metamorphic skin grafts from donors of the same genotype as the tail tissue donor, but rejection was not accelerated. It is proposed that tolerance induction is dependent on the presence of appropriately presented antigen at a time when precursor thymocyte cells are migrating to the thymus, prior to their processing into alloreactive cells, and that tolerance maintenance is dependent upon the persistence of the tolerizing antigen.
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35
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Kaye C, Tompkins R. Allograft rejection in Xenopus laevis following larval thymectomy. DEVELOPMENTAL AND COMPARATIVE IMMUNOLOGY 1983; 7:287-294. [PMID: 6347739 DOI: 10.1016/0145-305x(83)90010-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
Xenopus laevis thymectomized at stages 41 through 49 accept first set allografts, while animals thymectomized at stage 51 or older reject allografts in times similar to intact animals. However, thymectomy at progressively earlier stages results in a greater proportion of animals unable to reject second set grafts. In some animals, the allograft response remains deficient even after multiple challenges. The results indicate that alloreactive cells are thymus dependent, and suggest that the thymus processes precursor thymocytes starting upon its formation at around stage 41. The processed cells, competent to respond to alloantigens, are released to the periphery almost immediately. While an increasing pool of processed T cells accumulates during stages 41-49, the persistent defective allograft response displayed by animals thymectomized during these stages suggests that early thymectomy may leave a population of alloreactive cells qualitatively defective in some subpopulation necessary for normal allograft responses, or that any residual cells processed prior to thymectomy are capable of only limited clonal expansion.
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36
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Ide C, Reynolds P, Tompkins R. Duplication of positional information in regeneration of eye-bud fragments results from a specific healing pattern. Int J Dev Neurosci 1983. [DOI: 10.1016/0736-5748(83)90336-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022] Open
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37
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Gibbs DA, Spellacy E, Tompkins R, Watts RW, Mowbray JF. A clinical trial of fibroblast transplantation for the treatment of mucopolysaccharidoses. J Inherit Metab Dis 1983; 6:62-81. [PMID: 6410119 DOI: 10.1007/bf02338973] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
This paper reports the clinical and biochemical results in six patients with Hurler disease (Mucopolysaccharidosis IH; McKusick 25280), two patients with Hunter disease (Mucopolysaccharidosis II; McKusick 25285) and one patient with Sanfilippo B disease (Mucopolysaccharidosis IIIB; McKusick 25292) who were treated by fibroblast transplantation. Except for one patient who died for a coincidental reason, the patients have been studied for between 2.5 and 4.5 years. The clinical course of the disease was not materially altered. There was no evidence that the patients had developed immune responses against the transplanted fibroblasts. Transplantation did not produce measurable levels of either alpha-L-iduronidase (EC 3.2.1.76) in the leukocytes from patients with Hurler disease or of N-acetyl-alpha-D-glucosaminidase (EC 3.2.1.50) in the plasma of the patients with Sanfilippo B disease. Under the conditions used for the assay, leukocytes from the patients with Hunter disease had detectable levels of residual alpha-L-idurono-2-sulphate sulphatase activity which were increased after the transplants, although these changes were of inconstant size and their time course was not consistently related to the transplantations. Cytogenetic studies in cases where the donor was of the opposite sex detected only cells of the recipient's sex among the fibroblasts grown from biopsies of the transplantation sites. The technique used would have detected a donor to recipient cell ratio of 1:100. We found no consistent long-term trends in the excretion patterns of glycosaminoglycans and oligosaccharides from either a quantitative or qualitative point of view which could be specifically related to the transplantation. The combined administration of immunosuppressive doses of prednisolone and azathioprine was associated with an increased excretion of the lower molecular weight glycosaminoglycans. We conclude that fibroblast transplantation is not therapeutically useful in the diseases studied.
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38
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Taylor JR, Tompkins R, Demers R, Anderson D. Electroconvulsive therapy and memory dysfunction: is there evidence for prolonged defects? Biol Psychiatry 1982; 17:1169-93. [PMID: 7171661] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
The authors reviewed 39 papers which concern the long-term effects of electroconvulsive therapy (ECT) on human memory. Although the authors caution that methodological considerations preclude a decisive assessment, the majority of the studies suggest that ECT does not normally produce prolonged memory defects. Some recent studies do document subtle but persistent defects several months after ECT, especially in personal autobiographical material. These defects appear to be more annoying than seriously incapacitating. Variables considered important in an ideal design of studies on ECT and memory are discussed.
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39
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Mischler W, Rosenberry G, Frischmann P, Tompkins R. Test Results on a Low Loss Amorphous Iron Induction Motor. ACTA ACUST UNITED AC 1981. [DOI: 10.1109/tpas.1981.316408] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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40
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Volpe EP, Tompkins R, Reinschmidt D. Clarification of studies on the origin of thymic lymphocytes. THE JOURNAL OF EXPERIMENTAL ZOOLOGY 1979; 208:57-66. [PMID: 313974 DOI: 10.1002/jez.1402080107] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
The thesis that lymphocytes originate in situ by the direct transformation of epithelial cells within the thymic primordium in anurous frogs is untenable. On the contrary, in both the leopard frog and the African clawed toad, the lymphocytes that first appear in the embryonic thymus are derived from extrathymic lymphopoietic cells that invaded the developing organ. The exact source of origin of the invading lymphopoietic cells remains problematic.
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41
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Ide CF, Tompkins R, Miszkowski N. Neuroanatomy of Spastic, a behavior mutant of the mexican axoloti: Purkinje cell distribution in the adult cerebellum. J Comp Neurol 1977; 176:373-86. [PMID: 915044 DOI: 10.1002/cne.901760306] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
The spastic mutant, found in the Mexican axolotl, shows swimming coordination and equilibrium deficiencies. Histological analyses of wild-type and spastic mutant cerebella previously characterized in physiological studies revealed changes in Purkinje cell location in the mutant auricle or vestibulo-cerebellum. Purkinje cells are "translocated" ventrally correlated with a similar translocation of vestibular single units described previuosly (Ide, '77). Where wild-type Purkinje cells are distributed from the surface to a depth of 250 micrometers, mutant Purkinje cells are "crowded" between 250 and 350 micrometers. Although mutant granule cells are present, boundaries between granule cell and Purkinje cell zones are less precise in mutants. Cerebellar nucleus cells are translocated medially, failing to organize into the discrete cell group appearing in wild-type. Cerebellar white matter tracts and fibers show changes, both in orientation with respect to the underlying tegmentum, and in fascicular organization. Obvious changes in the gross anatomy of the cerebellum are confirmed in reconstructions which define cell and fiber translocation. Thus, the spastic gene is compatible with differentiation of all cerebellar elements, but appears to alter interactions between cells, or between cells and the external milieu. Although all cell types are present in the mutant cerebellum, they fail to attain their proper positions along all three body axes.
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42
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43
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Bloom EM, Tompkins R. Selective reinnervation in skin rotation grafts in Rana pipiens. THE JOURNAL OF EXPERIMENTAL ZOOLOGY 1976; 195:237-46. [PMID: 772156 DOI: 10.1002/jez.1401950208] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Skin rotation grafts were performed in Rana pipiens tadpoles producing misdirected reflexes in adult frogs. The pattern of innervation fields of dorsal and ventral rami of segmental nerves 3, 4, 5 and 6 were investigated by recording from the severed rami with suction electrodes. Innervation patterns of regenerated fields were influenced by graft borders and adjacent fields. Misdirected reflexes were found for ventral skin on the dorsal side only when innervated by ventral rami in a manner never seen in normal or sham operated animals. This suggested that selective reinnervation has occurred.
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44
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Ide CF, Tompkins R. Development of locomotor behavior in wild type and spastic (sp/sp) axolotls, Ambystoma mexicanum. THE JOURNAL OF EXPERIMENTAL ZOOLOGY 1975; 194:467-78. [PMID: 1202151 DOI: 10.1002/jez.1401940303] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
The homozygous recessive spastic mutant found in the Mexican axolotl shows violent coiling and thrashing behavior when subjected to strong tactile or electrical stimulation. In order to establish the time of onset of the first behavioral manifestation of the spastic gene, an etiological analysis of the ontogeny of swimming behavior in mutants and wild type siblings was undertaken. The locomotor patterns shown by embryos in response to an electrical stimulus were analyzed quantitatively from the embryonic early flexure stage through the larval early feeding stage. Spastic larvae failed to show dorsal-up swimming frequencies equal to those of sibling controls from day 12 (Harrison stage 40) of development indicating a lack of equilibrium. Both spastics and their siblings showed "sinusoid swimming" and "coiling" behavior in response to an aversive stimulus through day 18 (Harrison state 46, early feeding stage) of development. From day 18, wild type siblings abruptly decreased "coiling" behavior and showed strong "escape swimming" in response to an intense stimulus. Spastics never developed "escape swimming" patterns but retained a mixture of "sinusoid swimming" and "coiling" patterns characteristic of pre-feeding stage larvae.
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45
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Diamond H, Alexander S, Kuzell W, Lussier A, Odone D, Tompkins R. Naproxen and aspirin in rheumatoid arthritis: a multicenter double-blind crossover comparison study. J Clin Pharmacol 1975; 15:335-9. [PMID: 1092727 DOI: 10.1002/j.1552-4604.1975.tb01461.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
One hundred nineteen adults with active definite or classical rheumatoid arthritis were studied in a multicenter double-blind crossover study of naproxen (500 mg/day) and aspirin (3.6 Gm/day). Each drug was given in sequence for a six-week study period. Patients already receiving corticosteriod and/or gold therapy were maintained at constant dose throughout the study, but analgesics and other nonsteroidal antiinflammatory agents were discontinued at baseline. Objective and subjective evaluations by both investigator and patient were carried out at two-week intervals. No significant difference in global evaluation of efficacy or individual measures of efficacy was observed between aspirin and naproxen therapy, although physicians' global evaluation tended to favor naproxen. Sedimentation rate was lower on aspirin (naproxen 43.1 mm/hr; aspirin 38.7 mm/hr; P=0.02). Naproxen, 250 mg twice daily, was significantly better tolerated than aspirin, 900 mg four times daily. Mild, moderate, and severe side effects were less frequent with naproxen. The incidence of heartburn was significantly lower on naproxen, and significantly fewer patients terminated their six-week study period on naproxen than on aspirin. There were no significant deviations from baseline values in hematocrit, white cell or differential counts, or in tests of renal and hepatic function during the course of the study.
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46
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Heidemann SR, Townsend J, Tompkins R. Synthesis of soluble protein in oocytes of Xenopus laevis. THE JOURNAL OF EXPERIMENTAL ZOOLOGY 1975; 191:253-60. [PMID: 1113071 DOI: 10.1002/jez.1401910211] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Oocytes of five stages of development were isolated from ovaries of Xenopus laevis and allowed to take up radioactive amino acids. After six hours of labeling the amount of label incorporated into perchloric acid precipitable material from the soluble oocyte fraction and the specific activity of the label free pool was determined. From these figures an estimate of the rate of protein synthesis was calculated. Labeled soluble protein from each oocyte stage was analyzed by electrophoresis on SDS polyacrylamide gels. The gel was dried and autoradiographed to determine the qualitative pattern of soluble protein synthesis during various stages of oogenesis. Our results indicate that no significant differences exist in the rate of protein synthesis among any of the stages of oogenesis investigated. The qualitative pattern of soluble protein synthesized during the labeling period is similar among the oocyte stages. Moreover, this qualitative pattern of soluble protein synthesis is the same as the pattern of soluble protein accumulated up to that time during oogenesis. These results suggest a stable synthesis and accumulation of maternal protein products during Xenopus oogenesis, in marked contrast to the results that have been reported for RNA synthesis during oogenesis in Xenopus. Our results are discussed in terms of the present understanding of the process of maternal information accumulation.
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47
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Diamond H, Alexander S, Kuzell W, Lussier A, Odone D, Tompkins R. A multi-center double-blind crossover comparison study of naproxen and aspirin in patients with rheumatoid arthritis. Scand J Rheumatol 1973; 2:171-5. [PMID: 4590045 DOI: 10.3109/03009747309097120] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
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48
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Caskey C, Scolnick E, Tompkins R, Milman G, Goldstein J. [38] Release factors: in vitro assay and purification. Methods Enzymol 1971. [DOI: 10.1016/s0076-6879(71)20040-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/07/2023]
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49
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Tompkins R. Biochemical effects of the gene g on the development of the axolotl Ambystoma mexicanum. Dev Biol 1970; 22:59-83. [PMID: 5423308 DOI: 10.1016/0012-1606(70)90006-0] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
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50
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Caskey T, Scolnick E, Tompkins R, Goldstein J, Milman G. Peptide chain termination, codon, protein factor, and ribosomal requirements. COLD SPRING HARBOR SYMPOSIA ON QUANTITATIVE BIOLOGY 1969; 34:479-88. [PMID: 4909515 DOI: 10.1101/sqb.1969.034.01.054] [Citation(s) in RCA: 71] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
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