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Craw LA, Saunders NR, Koelink E, Roth J, Aronson L, Silverman MS, Roth S, Ortuoste B, Scolnik D. Anthropometric Measurement of School-Aged Children in Guyana, South America. Paediatr Child Health 2010. [DOI: 10.1093/pch/15.suppl_a.56ab] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
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Silverman MS, Reynolds D, Kavsak PA, Garay J, Daly A, Davis I. Use of an interferon-gamma based assay to assess bladder cancer patients treated with intravesical BCG and exposed to tuberculosis. Clin Biochem 2007; 40:913-5. [PMID: 17512514 DOI: 10.1016/j.clinbiochem.2007.04.006] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2006] [Revised: 04/07/2007] [Accepted: 04/14/2007] [Indexed: 11/23/2022]
Abstract
OBJECTIVE Compare the QuantiFERON-TB Gold In-Tube (QFT) assay and the tuberculin skin test (TST) in bladder cancer patients receiving high dose BCG therapy (BCG patients). DESIGN AND METHODS BCG patients and healthy visitors, both exposed to tuberculosis, were screened with a TST and QFT. RESULTS QFT-TST correlation was excellent in visitors, but poor in BCG patients. BCG therapy predicted a positive TST (p<0.001) but not a positive QFT (p=0.35). DISCUSSION The management of BCG patients was impacted, by measuring the QFT.
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Silverman MS, Aronson L, Eccles M, Eisenstat J, Gottesman M, Rowsell R, Ferron M, Scolnik D. Leptospirosis in febrile men ingesting Agouti paca in South America. Ann Trop Med Parasitol 2005; 98:851-9. [PMID: 15667717 DOI: 10.1179/000349804x3216] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
To explore the relationship between the ingestion of Agouti paca (AP) and human leptospirosis in Guyana, 19 febrile men who said they had hunted and eaten A. paca were screened for malaria, using bloodsmears, and for leptospirosis, using an enzyme immuno-assay that detects Leptospira -specific IgM. Those found positive for anti-Leptospira IgM were then evaluated further, with a microscopical agglutination test based on a limited panel of serovars from three pathogenic species of Leptospira. Although six of the 18 patients who provided suitable samples for the serology were found seropositive for acute leptospirosis, only three of the 19 patients were found smear-positive for malaria. A clinical-decision model, based on medical histories, the results of physical examinations, and the use of routine urine dipsticks, and enabling prediction of the serological results, was developed. This model, which had 83% sensitivity and 100% specificity for leptospirosis, indicated that, in the absence of serology, most febrile patients reporting AP ingestion could be correctly treated if each was checked for malaria using traditional bloodsmears. The smear-positives should be treated with antimalarial drugs whereas the smear-negatives should be treated for leptospirosis if they had any of the following: a skin rash; lymphadenopathy; abnormal urine sediment (proteinuria or haematuria); and/or no previous history of malaria. In the present study, the relative risk of leptospirosis among the patients who were smear-negative for malaria and fulfilled at least one of these four criteria was 13 (P = 0.0007). In Guyana at least, leptospirosis appears to be common among men who hunt, prepare and ingest AP. Vaccines may be the best, practical form of protection among such men.
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Galloucis M, Silverman MS, Francek HM. The impact of trauma exposure on the cognitive schemas of a sample of paramedics. Int J Emerg Ment Health 2001; 2:5-18. [PMID: 11232104] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/19/2023]
Abstract
This study examines disruptions in cognitive schemas (i.e., core beliefs about self, others, and the world) among a sample of paramedics. Two hundred fifty-three paramedics working in non-urban and urban settings completed measures of non-work and work-related negative life event and trauma exposure, perceived social support, and cognitive schemas. Forty percent of the respondents experienced at least one disrupted schema and 18 percent had disrupted beliefs about the meaningfulness of the world. Urban paramedics experienced greater disruption in cognitive schemas, particularly with Other-Safety beliefs. The degree of disruption in schemas was independently associated with the extent of non-work and work-related negative life event and trauma exposure, as well as perceived social support. These findings suggest the importance of investigating disruptions of schemas as a posttraumatic sequela among emergency medical personnel.
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Affiliation(s)
- M Galloucis
- Illinois Department of Corrections-Juvenile Division, USA.
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Eng KT, Liu ES, Silverman MS, Berger AR. Lipemia retinalis in acquired immunodeficiency syndrome treated with protease inhibitors. Arch Ophthalmol 2000; 118:425-6. [PMID: 10721972] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/15/2023]
Affiliation(s)
- K T Eng
- Sunnybrook Health Sciences Centre, Toronto, Ontario, Canada
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Mohand-Said S, Hicks D, Simonutti M, Tran-Minh D, Deudon-Combe A, Dreyfus H, Silverman MS, Ogilvie JM, Tenkova T, Sahel J. Photoreceptor transplants increase host cone survival in the retinal degeneration (rd) mouse. Ophthalmic Res 1997; 29:290-7. [PMID: 9323720 DOI: 10.1159/000268027] [Citation(s) in RCA: 73] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Retinal transplants offer a potentially interesting approach to treating human retinal degenerations, but so far little quantitative data are available on possible beneficial effects. We isolated photoreceptor layers from normal-sighted mice and grafted them into the subretinal space of retinal degeneration (rd) mice lacking rod photoreceptors. At 2 weeks after surgery, the numbers of residual host cone photoreceptors outside the graft zone were quantified following specific labelling. Examination of operated retinas revealed highly significantly greater numbers of surviving cones (mean of 38% more at 2 weeks) within the central field compared to sham-operated paired control retinas (p < 0.01). These are the first quantified data indicating a trophic effect of transplanted photoreceptors upon host cone cells. As cone cells are responsible for high acuity and colour vision, such data could have important implications not only for eventual therapeutic approaches to human retinal degenerations but also to understanding underlying interactions between retinal photoreceptors.
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Affiliation(s)
- S Mohand-Said
- Laboratoire de Physiopathologie Rétinienne INSERM CJF 92/02-ULP, Centre Hospitalier et Universitaire, Strasbourg, France
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Abstract
PURPOSE Retinal dystrophic (rd) mice lose most of their rod photoreceptors within the first three weeks after birth. We determined the age-related distribution of peanut agglutinin lectin (PNA)-labeled cones during the first 12 months of age. We also investigated whether the density of ON-bipolar cells expressing L7 protein was affected by their loss of photoreceptor inputs. METHODS rd mice were selected from a transgenic strain which expresses an L7-beta-galactosidase fusion gene localized to ON-bipolar cells. Cones were stained with PNA and ON-bipolar cells with bluo-gal (halogenated indolyl-beta-D-galactoside). Retinas were flat-mounted and observed at 1, 2, 3, 6 and 12 months of age. RESULTS PNA-labeled cones are distributed unevenly across the retina at 1 month postnatal. Their concentration decreases first in the central and far peripheral retina, leaving a ring of labeled cells in the midperipheral region. At 3 months, a larger patch of cones remains in the supero-temporal midperipheral region and a smaller patch in the infero-nasal retina. By 6 months, few cones remain in the infero-nasal retina; by 1 year approximately 100 cones remain in the entire retina, localized to the superior midperipheral region. ON-bipolar cells appear evenly distributed at 1 month. By 2-3 months, relatively more bluo-gal staining is seen in the midperipheral regions underlying dense cone populations. At 6-12 months, bluo-gal label is distributed in a spotty pattern with little or no staining seen in areas of apparent neovascularization. CONCLUSIONS (1) PNA-labeling of cones in the rd retina deteriorates in a distinct spatial pattern with the longest cone survival in the midperipheral superior retina. (2) ON-bipolar cells are more densely labeled in regions of high cone density during the early months of cone degeneration and, in later stages, show relative decreases in regions of apparent neovascularization.
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Affiliation(s)
- J M Ogilvie
- Central Institute for the Deaf, St. Louis, MO 63110, USA
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Valentino TL, Kaplan HJ, Del Priore LV, Fang SR, Berger A, Silverman MS. Retinal pigment epithelial repopulation in monkeys after submacular surgery. Arch Ophthalmol 1995; 113:932-8. [PMID: 7605287 DOI: 10.1001/archopht.1995.01100070106033] [Citation(s) in RCA: 48] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
BACKGROUND Transplantation of retinal pigment epithelium may be a treatment for retinal diseases, such as age-related macular degeneration and hereditary macular degeneration. Before transplantation studies are undertaken, questions concerning repopulation of retinal pigment epithelial cells in situ and photoreceptor repair after submacular surgery need to be addressed. METHODS We removed the retinal pigment epithelium from Bruch's membrane in the macaque monkey in the macula and outside the vascular arcades. This model allowed the study of in situ retinal pigment epithelium regrowth and photoreceptor repair for 9 months following débridement. RESULTS Fluorescein angiography revealed a window defect in the area of denuded retinal pigment epithelium. Histologic studies revealed repopulated nonpigmented retinal pigment epithelial cells in the denuded areas in both the early and late periods. At 9 months, the repopulated retinal pigment epithelium was associated with repaired, normal-appearing photoreceptor outer segments. Retinal pigment epithelium regrowth was observed only if Bruch's membrane was intact. CONCLUSIONS Repopulation of retinal pigment epithelium in the adult primate can occur rapidly and can support the repair of damaged photoreceptors following submacular surgery.
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Affiliation(s)
- T L Valentino
- Department of Biology, St Louis (Mo) University, USA
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Abstract
A number of autosomal recessive syndromes feature both sensorineural hearing loss and retinal degeneration. The mouse mutant tubby also combines hearing loss with progressive retinal degeneration, and thus may constitute a useful model of one form of human sensorineural deafness/retinal dystrophic syndrome. It has not been directly demonstrated that the hearing loss in this mouse involves the cochlea, however. We have examined the cochleas of adult tubby mice using light microscopy. The tubby cochlea shows pronounced degeneration of the organ of Corti and loss of afferent neurons in the base, with relative sparing of the apex. Our findings support the tubby mouse as a model of human sensorineural deafness/retinal dystrophic syndrome. Possible human counterparts include Usher's, Alstrom's, and Bardet-Biedl syndromes.
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Affiliation(s)
- K K Ohlemiller
- Research Department, Central Institute for the Deaf, St. Louis, MO 63110, USA
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Silverman MS. A physician who came home. CMAJ 1994; 150:323-4. [PMID: 8293364 PMCID: PMC1486184] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
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Silverman MS, Gartner JG, Halliday WC, Kohl S, Embree J, Kohn S. Persistent cerebrospinal fluid neutrophilia in delayed-onset neonatal encephalitis caused by herpes simplex virus type 2. J Pediatr 1992; 120:567-9. [PMID: 1313097 DOI: 10.1016/s0022-3476(05)82485-0] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
We describe an infant with three unusual features of perinatally acquired herpes simplex virus type 2 encephalitis: onset of illness at 34 days of age, absolute cerebrospinal fluid neutrophilia, and systemic viral dissemination after central nervous system disease. To provide early, effective antiviral therapy, clinicians should be aware of atypical presentations of serious herpes simplex virus infections.
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Affiliation(s)
- M S Silverman
- Department of Pediatrics, University of Manitoba, Winnipeg, Canada
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Silverman MS, Maclean I, Zong GM, Nath A. An improved enzyme-linked immunoadsorbent assay for the detection of antibodies to galactocerebroside. Biotechniques 1992; 12:232, 234. [PMID: 1616716] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Affiliation(s)
- M S Silverman
- Dept. of Medical Microbiology, University of Manitoba, Winnipeg, Canada
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Abstract
Adult New Zealand Red (NZR) rabbits were used to determine if the techniques developed in the rat to transplant sheets of photoreceptors could be adapted to larger eyes of the rabbit. Adult donor NZR rabbit retina was cut into small strips, oriented, and drawn up in a small and flat polyethylene tube. By transscleral approach, donor retina was correctly oriented and gently placed into the subretinal space of host retinas that were previously ablated of photoreceptors by intravitreal injection of hemoglobin. Two weeks after surgery, rabbits were terminated and eyes processed for histology. Morphologic evaluation indicated that photoreceptors were transplantable between adult rabbits by adaptation of previously developed methods and that they were well maintained for 2 weeks. Transplanted photoreceptors also appeared to retain nearly normal inner and outer segment (I & OS) morphology and anti-opsin reactivity. Finally, inclusion of the inner retina also appeared to help maintain the correct I & OS apposition to the host retinal pigmented epithelium.
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Affiliation(s)
- S T Schuschereba
- Letterman Army Institute of Research, Presidio of San Francisco, California 94129
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Silverman MS, Hughes SE, Valentino TL, Liu Y. Photoreceptor transplantation: anatomic, electrophysiologic, and behavioral evidence for the functional reconstruction of retinas lacking photoreceptors. Exp Neurol 1992; 115:87-94. [PMID: 1728579 DOI: 10.1016/0014-4886(92)90227-h] [Citation(s) in RCA: 55] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
We have investigated the possibility of using transplantation of immature or mature rodent photoreceptors as well as mature human photoreceptors to reconstruct retinas in which photoreceptor degeneration is either inherited or environmentally induced. To this end, we have devised methods for isolating and transplanting the outer nuclear layer (ONL) (e.g., the photoreceptor layer) to the subretinal space of mature rodents. In addition we found that if portions of the inner retina are transplanted along with the intact photoreceptor sheet, photoreceptor organization is better maintained. In ultrastructural studies of the reconstructed retina an outer plexiform-like layer (OPL) is visible at the interface of the transplanted ONL and the host inner nuclear layer, with invaginating ribbon synapses characteristic of those formed by rod photoreceptors evident within this OPL. Ribbon synapses are found only rarely in unreconstructed retina. These results suggest that synaptic connections between transplanted photoreceptors and host cells may be made. Evidence for the potential recovery of function following photoreceptor transplantation is found in visually evoked cortical responses and behavioral responses (pupillary reflex) to light stimulation of the reconstructed eye. These findings suggest the possibility that neural transplantation can reconstruct a sensory end organ--in this case the retina--to restore evoked activity and an appropriate behavioral response to sensory stimulation.
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Affiliation(s)
- M S Silverman
- Central Institute for the Deaf, St. Louis, Missouri 63110
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Abstract
Embryonic rat inner ears were transplanted to the anterior chamber of the eyes of adult rats. While considerable development was evident, the structures present were limited to the vestibular division. We hypothesized that this selective survival could be due to the rate of vascularization. To test the effects of graft vascularization we made transplants in which the internal structures were exposed by removing the apex and base of the developing cochlea. The transplants were rapidly vascularized by the iris. Many of the soft labyrinthine structures of the cochlea from 1-day-old donors showed considerable development, including the spiral limbus, basilar membrane, and organ of Corti. To test the possibility that the cochlea requires inductive or trophic support beyond Embryonic Day 15 (E15), we cotransplanted the embryonic inner ear with developing brain stem. In these transplants, we observed improved development of the cochlea, with spiral ganglion cells and an organ of Corti possessing hair cells, Deiter's cells, and pillar cells. To further address the effect of developing CNS tissue on the development of grafted inner ear, we transplanted E15 inner ears to either the cortex or the brain stem of neonatal rats. In these experiments we have seen evidence of both vestibular and cochlear sensory surfaces. In the cochlea, an organ of Corti-like structure can be seen. The possibility of neural connections with the host brain has yet to be investigated.
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Affiliation(s)
- S E Hughes
- Sensory Neuroscience Laboratory, Central Institute for the Deaf, St. Louis, Missouri 63110
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Silverman MS, MacLeod JP. Pancoast's syndrome due to staphylococcal pneumonia. CMAJ 1990; 142:343-5. [PMID: 2302632 PMCID: PMC1451815] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
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Abstract
Transplantation of normal retinal pigment epithelium (RPE) to the subretinal space has been reported to rescue photoreceptors in the RCS rat. Moreover, the rescue effect was surprisingly large considering the relatively small number of RPE cells transplanted. The reason for this widespread rescue of photoreceptors is not known, nor is the mechanism for outer segment phagocytosis in photoreceptors not apposed to the transplanted RPE cells. This suggests that the rescue effect may not be solely mediated by the transplanted cells. We therefore wished to test whether the transplantation surgery itself might contribute to the rescue of RCS photoreceptors. For these control experiments, we performed the surgery on juvenile RCS rats as described by others for the transplantation of RPE but instead of injecting RPE, we injected saline. We sacrificed the RCS control operates two months following surgery. In the area of the surgery (superior retinal quadrant) the outer nuclear layer (ONL) was up to 8-10 photoreceptor cells thick, while at the extreme inferior margin of the retina the ONL was almost eliminated. To investigate the role of temporary retinal detachment in photoreceptor rescue we repeated the above experiment using our trans-corneal approach to the subretinal space. This procedure results in a large temporary retinal detachment and little or no damage to the choroid and sclera.(ABSTRACT TRUNCATED AT 250 WORDS)
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Affiliation(s)
- M S Silverman
- Sensory Neuroscience Laboratory, Central Institute for the Deaf, St. Louis, MO 63110
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Abstract
We have studied the effects of GH on basal and insulin-stimulated hexose transport by 3T3-F442A adipocytes in a hormonally defined serum-free medium. Adipocytes preincubated in defined medium exhibit a low level of hexose transport which is acutely (15 min) stimulated (greater than 5-fold) by insulin (EC50, 0.1-0.2 nM). GH has acute (15-45 min) insulin-mimetic (greater than 2-fold) and chronic (4-48 h) diabetogenic (50-80%) effects on basal and insulin-stimulated hexose transport. The insulin-mimetic effect of GH has a higher EC50 (2 nM) than its diabetogenic effect (EC50, 0.2 nM). Chronic GH exposure decreases the maximal responsiveness (50-80%) and the acute sensitivity (approximately 2-fold) of hexose transport to insulin. Insulin-stimulated transport is more (approximately 5-fold) sensitive to the diabetogenic effect of GH than is basal transport. Insulin binding and degradation were not altered by chronic exposure to GH. The diabetogenic effect of GH may occur at a postinsulin binding level.
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Affiliation(s)
- M S Silverman
- Memorial Sloan-Kettering Cancer Center, Cornell University Medical College, New York, New York 10021
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Silverman MS, Hughes SE. Transplantation of photoreceptors to light-damaged retina. Invest Ophthalmol Vis Sci 1989; 30:1684-90. [PMID: 2527211] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
We investigated the possibility of reconstructing light-damaged retinas by photoreceptor transplantation. The outer nuclear layer containing the photoreceptor cells was eliminated in adult albino rat retinas by exposure to constant high-level illumination. Photoreceptors for transplantation were harvested from neonatal rats using a novel isolation technique that maintained the cellular organization of the outer nuclear layer. Transplantation was accomplished using a transcorneal approach to the subretinal space, which minimized trauma to the eye. The retina reattached to the back of the eye with transplanted photoreceptors interposed between the retina and the overlying tissues. Prelabelling with fluorescent dye enabled positive identification of the transplanted cells. The transplanted photoreceptors appeared to survive transplantation for at least 6 weeks and were immunohistochemically reactive for opsin. The antibody staining for opsin identifies the transplanted cells as photoreceptors and indicates that they are still capable of producing visual pigment and therefore may have the capacity to transduce light. These findings indicate that photoreceptors can be transplanted to form a new outer nuclear layer in a damaged mature retina.
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Affiliation(s)
- M S Silverman
- Central Institute for the Deaf, Washington University, St. Louis, Missouri
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Abstract
We measured the spatial-frequency tuning of cells at regular intervals along tangential probes through the monkey striate cortex and correlated the recording sites with the cortical cytochrome oxidase (CytOx) patterns to address three questions with regard to the cortical spatial-frequency organization. (i) Is there a periodic anatomical arrangement of cells tuned to different spatial-frequency ranges? We found there is, because the spatial-frequency tuning of cells along tangential probes changed systematically, varying from a low frequency to a middle range to high frequencies and back again repeatedly over distances of about 0.6-0.7 mm. (ii) Are there just two populations of cells, low-frequency and high-frequency units, at a given eccentricity (perhaps corresponding to the magno- and parvocellular geniculate pathways) or is there a continuum of spatial-frequency peaks? We found a continuum of peak tuning. Most cells are tuned to intermediate spatial frequencies and form a unimodal rather than a bimodal distribution of cell peaks. Furthermore, the cells with different peak frequencies were found to be continuously and smoothly distributed across a module. (iii) What is the relation between the physiological spatial-frequency organization and the regions of high CytOx concentration ("blobs")? We found a systematic correlation between the topographical variation in spatial-frequency tuning and the modular CytOx pattern, which also varied continuously in density. Low-frequency cells are at the center of the blobs, and cells tuned to increasingly higher spatial frequencies are at increasing radial distances.
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Affiliation(s)
- M S Silverman
- Department of Psychology and Neurobiology Group, University of California, Berkeley 94720
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Tootell RB, Switkes E, Silverman MS, Hamilton SL. Functional anatomy of macaque striate cortex. II. Retinotopic organization. J Neurosci 1988; 8:1531-68. [PMID: 3367210 PMCID: PMC6569212] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
Macaque monkeys were shown retinotopically-specific visual stimuli during 14C-2-deoxy-d-glucose (DG) infusion in a study of the retinotopic organization of primary visual cortex (V1). In the central half of V1, the cortical magnification was found to be greater along the vertical than along the horizontal meridian, and overall magnification factors appeared to be scaled proportionate to brain size across different species. The cortical magnification factor (CMF) was found to reach a maximum of about 15 mm/deg at the representation of the fovea, at a point of acute curvature in the V1-V2 border. We find neither a duplication nor an overrepresentation of the vertical meridian. The magnification factor did not appear to be doubled in a direction perpendicular to the ocular dominance strips; it may not be increased at all. The DG borders in parvorecipient layer 4Cb were found to be as sharp as 140 micron (half-amplitude, half width), corresponding to a visual angle of less than 2' of arc at the eccentricity measured. In other layers (including magnorecipient layer 4Ca), the retinotopic borders are broader. The retinotopic spread of activity is greater when produced by a low-spatial-frequency grating than when produced by a high-spatial-frequency grating. Orientation-specific stimuli produced a pattern of activation that spread further than 1 mm across cortex in some layers. Some DG evidence suggests that the spread of functional activity is greater near the foveal representation than near 5 degrees eccentricity.
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Affiliation(s)
- R B Tootell
- Department of Psychology, University of California, Berkeley 94720
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Tootell RB, Hamilton SL, Silverman MS, Switkes E. Functional anatomy of macaque striate cortex. I. Ocular dominance, binocular interactions, and baseline conditions. J Neurosci 1988; 8:1500-30. [PMID: 3367209 PMCID: PMC6569205] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
A series of experiments was carried out using 14C-2-deoxy-d-glucose (DG) in order to examine the functional architecture of macaque striate (primary visual) cortex. This paper describes the results of experiments on uptake during various baseline (or reference) conditions of visual stimulation (described below), and on differences in the functional architecture following monocular versus binocular viewing conditions. In binocular "baseline" experiments, monkeys were stimulated either (1) in the dark, (2) with a diffuse gray screen, or (3) with a very general visual stimulus composed of gratings of varied orientation and spatial frequency. In all of these conditions, DG uptake was found to be topographically uniform within all layers of parafoveal striate cortex. In monocular experiments that were otherwise similar, uptake was topographically uniform within the full extent of the eye dominance strip, in all layers. Certain other visual stimuli produce high uptake in the blobs, and still another set of visual stimuli (including high-spatial-frequency gratings) produce highest uptake between the blobs at parafoveal eccentricities, even in an unanesthetized, unparalyzed monkey. Eye movements per se had no obvious effect on striate DG uptake. Endogenous uptake in the blobs (relative to that in the interblobs) appears higher in the squirrel monkey than in the macaque. The pattern of DG uptake produced by binocular viewing was found to deviate in a number of ways from that expected by linearly summing the component monocular DG patterns. One of the most interesting deviations was an enhancement of the representation of visual field borders between stimuli differing from each other in texture, orientation, direction, etc. This "border enhancement" was confined to striate layers 1-3 (not appearing in any of the striate input layers), and it only appeared following binocular, but not monocular, viewing conditions. The border enhancement may be related to a suppression of DG uptake that occurs during binocular viewing conditions in layers 2 + 3 (and perhaps layers 1 and 4B), but not in layers 4Ca, 4Cb, 5 or 6. Another major class of binocular interaction was a spread of neural activity into the "unstimulated" ocular dominance strips following monocular stimulation. Such an effect was prominent in striate layer 4Ca, but it did not occur in layer 4Cb. This "binocular" spread of DG uptake into the inappropriate eye dominance strip in 4Ca may be related to the appearance of orientation tuning and orientation columns in that layer. No DG effects were seen that depended on the absolute disparity of visual stimuli in macaque striate cortex.
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Affiliation(s)
- R B Tootell
- Department of Psychology, University of California, Berkeley 94720
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Tootell RB, Silverman MS, Hamilton SL, De Valois RL, Switkes E. Functional anatomy of macaque striate cortex. III. Color. J Neurosci 1988; 8:1569-93. [PMID: 3367211 PMCID: PMC6569202] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
Using spatially diffuse stimuli (or sinusoidal gratings of very low spatial frequency), levels of 14C-2-deoxy-d-glucose (DG) uptake produced by color-varying stimuli are much greater than those produced by luminance-varying stimuli in macaque striate cortex. Such a difference in DG results is consistent with previous psychophysical and electrophysiological results from man and monkey. In DG experiments with color-varying gratings of low and middle spatial frequencies, or with spatially diffuse color variations, DG uptake was highest in the cytochrome oxidase blobs, as was also seen with low-spatial-frequency luminance gratings. High-spatial-frequency, color-varying uptake patterns were shifted to cover both blob and interblob regions in a manner similar to that of the patterns obtained with middle-spatial-frequency luminance stimuli. However, in no instance did chromatic gratings produce uptake restricted to the interblob regions, as with the pattern seen with the highest-spatial-frequency luminance gratings. Thus, DG uptake is relatively higher in the interblob regions when comparing luminance with color-varying gratings that are otherwise similar. It was also possible to show DG evidence for receptive-field double-opponency in the upper-layer blobs, but color sensitivity in layer 4Cb appears single-opponent. The DG results suggest that color sensitivity is also high in the lower-layer (layers 5 + 6) blobs, and that many layer 5 receptive fields are double-opponent. Striate layers 4Ca and 4B-appeared color-insensitive in a wide variety of DG tests; this supports the idea of a color-insensitive stream running from the magnocellular LGN layers through striate layers 4Ca and 4B to extrastriate areas MT and V3. There was also a major effect due to wavelength: long and short wavelengths produced much more uptake than did middle wavelengths, even when all colors were equated for luminance and saturation. No variation with eccentricity was seen in cortical color sensitivity, at least between 0 degrees and 10 degrees.
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Affiliation(s)
- R B Tootell
- Department of Psychology, University of California, Berkeley 94720
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Tootell RB, Silverman MS, Hamilton SL, Switkes E, De Valois RL. Functional anatomy of macaque striate cortex. V. Spatial frequency. J Neurosci 1988; 8:1610-24. [PMID: 3367213 PMCID: PMC6569194] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
When macaque monkeys view achromatic, sinusoidal gratings of a single spatial frequency, the pattern of 14C-2-deoxy-d-glucose (DG) uptake produced by the gratings is shown to depend on the spatial frequency chosen. When a relatively high (5-7 cycles/deg) spatial frequency is shown binocularly at systematically varied orientations, uptake in parafoveal striate cortex is highest between the cytochrome oxidase blobs (that is, in the interblobs) in layers 1, 2, and 3. In layers 4B, 5, and 6, where the cytochrome oxidase blobs are faint or absent, DG uptake is highest in a periodic pattern that lies in register with the interblobs of layers 2 + 3. When the grating is, instead, of relatively low (1-1.5 cycles/deg) spatial frequency, DG uptake is highest in the blobs, in the blob-aligned portions of layers 1-4B, and in the lower-layer blobs as well. These variations in DG topography are confirmed in stimulus comparisons within a single hemisphere. Presumably, this shift in functional topography within the extra-granular layer is the primate homolog of "spatial frequency columns" shown earlier in the cat (Tootell et al., 1981; Silverman, 1984). In the well-differentiated architecture of primate striate cortex, laminar differences produced by high- versus low-spatial-frequency gratings are visible as well. Gratings of very high spatial frequency produce much higher uptake in 4Cb (which receives input from the parvocellular LGN layers) than in 4Ca (which gets its input from the magnocellular LGN layers). Gratings of low spatial frequency produce the converse result. Presumably, cells in the magnocellular LGN layers and/or in the magnocellular-dominated layer 4Ca have lower average spatial frequency tuning (larger receptive fields) than their counterparts in the parvocellular LGN and/or in striate layer 4Cb. The DG patterns produced by various spatial frequencies also vary with eccentricity, in a manner consistent with known, eccentricity-dependent variations of receptive-field size and spatial frequency tuning. Thus, gratings of a "middle"-spatial-frequency range (4-5 cycles/deg) produce high uptake in the blobs near the foveal representation and high uptake in the interblobs at more peripheral eccentricities, including 5 degrees. This shift in DG topography also includes the transition zone near 3 degrees, where the level of stimulus-driven uptake is as high in the blob regions as it is in interblob regions. Variations in uptake between layers 4Ca and 4Cb, as a function of eccentricity, shift in parallel with the changes in the upper-layer topography.
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Affiliation(s)
- R B Tootell
- Department of Psychology, University of California, Berkeley 94720
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Silverman MS, Tootell RB. Modified technique for cytochrome oxidase histochemistry: increased staining intensity and compatibility with 2-deoxyglucose autoradiography. J Neurosci Methods 1987; 19:1-10. [PMID: 2434810 DOI: 10.1016/0165-0270(87)90016-1] [Citation(s) in RCA: 88] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Staining the brain for cytochrome oxidase (CO) produces patterns which can resemble the patterns produced by 2-deoxyglucose (2-DG) autoradiography. In order to assess the differences between CO patterns of long-term metabolic activity and 2-DG patterns of short-term activity, comparisons should, ideally, be made on the same section. Consequently, we have made certain modifications in the standard CO histologic procedure which improve the stain and allow both 2-DG autoradiography and CO staining on the same section.
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Abstract
Picture processing techniques are applied to 2-deoxyglucose autoradiographs of sections from striate cortex and to patterns resulting from staining these sections for cytochrome oxidase. This procedure allows computer identification of deoxyglucose active and inactive regions in the autoradiographs and cytochrome active and inactive regions in the stain patterns. Subsequently, the topographical relationship between these patterns can be quantitatively analyzed by means of overlap and density distribution measures and can be displayed using color enhanced graphics. The processing techniques have been applied in studies of the functional organization of visual cortex in primates. Computer graphic techniques have allowed implementation of split-field presentations of stimuli in deoxyglucose experiments. An application of this split-field technique for presenting multiple-stimuli to distinct parts of the visual field is described and an autoradiograph from a split-field experiment is shown.
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Abstract
Two procedures are described which allow cortical grey matter to be unfolded and flattened. Tangential sections of the flat-mounted tissue can reveal clear histological views of horizontal variations in cortical structure and function; these anatomical variations would be hard to see in sections cut by conventional techniques. Examples are presented from non-human primate tissue, but the technique has also been used successfully in a number of other mammalian species, including man. Advantages and disadvantages of the various methods for extracting topographical patterns from the cortex are discussed.
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Tootell RB, Hamilton SL, Silverman MS. Topography of cytochrome oxidase activity in owl monkey cortex. J Neurosci 1985; 5:2786-800. [PMID: 2995611 PMCID: PMC6565141] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
In primate cortical tissue which has been stained for the mitochondrial enzyme cytochrome oxidase, a topographical pattern of regularly spaced blobs has been demonstrated in primary visual cortex (Hendrickson, A. E., S. P. Hunt, and J. -Y. Wu (1981) Nature 292: 605-607; Horton, J. C., and D. H. Hubel (1981) Nature 292: 762-764), and a pattern of stripes has been shown in secondary visual cortex (V2) as well (Livingstone, M. S., and D. H. Hubel (1982) Proc. Natl. Acad. Sci. U. S. A. 79: 6098-6101; Tootell, R. B. H., M. S. Silverman, E. Switkes, and R. L. De Valois (1982) Soc. Neurosci. Abstr. 8: 707). These regular cytoarchitectonic landmarks have proven extremely useful in parsing the functional and anatomical architecture of these two cortical areas. In order to look for similar landmarks in other cortical areas of a primate, we completely unfolded the cortical gray matter in the owl monkey (Aotus trivirgatus), sectioned it parallel with the flattened cortical surface, and stained the tissue for cytochrome oxidase. Distinctive cytochrome oxidase topographies were found in about seven different cortical areas. As in other primates, area V1 is characterized by blobs and area V2 is characterized by strips. In the owl monkey, area MT is characterized by an elaborate topography of dark staining in layers 1 to 4, interspersed with light blob-shaped regions, and partially surrounded by a dark ring. Many of these topographic inhomogeneities are also reflected in the lower layer myelination topography in MT. Visual area(s) VP/VA is characterized by an irregular or strip-like topography. In some animals, a distinctive topography can be seen in area DX, which is presumably equivalent to either area DM or DI. Primary auditory cortex stains very darkly, but the overall shape of area A is quite variable and the borders are indistinct. Somatosensory area 3B stains quite darkly with sharp borders, but again the overall shape of area 3B is different from that previously described.
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Schwartz E, Tootell RB, Silverman MS, Switkes E, De Valois RL. On the mathematical structure of the visuotopic mapping of macaque striate cortex. Science 1985; 227:1065-6. [PMID: 3975604 DOI: 10.1126/science.3975604] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
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Tootell RB, Silverman MS, Switkes E, DE Valois RL. In Reply: On the mathematical structure of the visuotopic mapping of macaque striate cortex. Science 1985; 227:1066. [PMID: 17794232 DOI: 10.1126/science.227.4690.1066] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
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Feeney DJ, Silverman MS. A model framework of alcoholism counseling: cyclic process of intensification, paradoxical shifting, and differentiation. Am J Drug Alcohol Abuse 1984; 10:403-15. [PMID: 6528872 DOI: 10.3109/00952998409001479] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
While recent literature on individual and family therapy has increasingly focused on the nature and use of paradoxical styles of intervention, little has been published concerning the use of paradox in alcoholism counseling. Alcoholism represents a type of problem that can lend itself to the use of such interventions. This paper first reviews the nature of paradoxical styles of intervention in relation to alcoholism. It then presents three developmentally determined paradoxical dynamics: intensification, paradoxical shifting, and differentiation. These are defined and examples from case studies are given for each. Therapists working with alcoholics are encouraged to consider the use of these patterns of response with their clients.
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Abstract
The functional organization of the second cortical visual area was examined with three different anatomical markers: 2-[14C]deoxy-D-glucose, cytochrome oxidase, and various myelin stains. All three markers revealed strips running throughout the area, parallel to the cortical surface. The boundaries of these strips provide an anatomical criterion for defining the borders of this extrastriate region. Further, the demonstration of these strips allows a functional and anatomical analysis of modules in the area, just as the recent demonstration of spots in the primary visual cortex has allowed an analysis of modules there. The strips differ structurally and functionally from interstrip regions and these differences are similar to those seen between the spots and the interspot regions in the primary visual cortex. In the macaque the strips and spots differ with regard to binocular organization.
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Abstract
We have anatomically analyzed retinotopic organization using the 14C-labeled 2-deoxy-D-glucose method. The method has several advantages over conventional electrophysiological mapping techniques. In the striate cortex, the anatomical substrate for retinotopic organization is surprisingly well ordered, and there seems to be a systematic relationship between ocular dominance strips and cortical magnification. The 2-deoxyglucose maps in this area appear to be largely uninfluenced by known differences in long-term metabolic activity. This method should prove useful in analyzing retinotopic organization in various visual areas of the brain and in different species.
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Abstract
Using the activity-dependent 2-[14C]deoxy-D-glucose technique, we have demonstrated a columnar organization of spatial frequency--specific sensitivity in striate cortex. Cats viewing patterns containing a single spatial frequency presented at all orientations show columns of increased deoxyglucose uptake extending through all cortical layers. A control stimulus containing all spatial frequencies presented at all orientations produces no columnar density differences within the striate cortex.
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Feeney DJ, Silverman MS. Paradox in alcoholism. Am J Drug Alcohol Abuse 1981; 8:513-32. [PMID: 6753571 DOI: 10.3109/00952998109016933] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
This work focuses upon paradoxical aspects of alcoholism. Current information suggests that double-binding dynamics exist in alcoholism and that paradoxical life-style themes do contribute to alcoholism abuse. Emphasis in this paper is focused upon the utilization of paradoxical dynamics within a therapeutic framework. It is suggested that treatment interventions must effectively alter negative paradoxical patterns operating in the alcoholic's life-style. Recent clinical findings are cited, and therapeutic uses of paradoxical and reframing and interventions are discussed.
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Mandelkorn J, Silverman MS, Harrison JE, Hanker JS. Immunofluorescent demonstration of myeloperoxidase of phi bodies and rods in leukaemic leucocytes. Histochem J 1980; 12:449-56. [PMID: 6254928 DOI: 10.1007/bf01011960] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Previous studies employing enzyme histocytochemical methods based on the catalysis of the peroxidation of 3,3'-diaminobenzidine (DAB) demonstrated the presence of hydroperoxidase activity in phi bodies and rods of immature leucocytes of patients with active acute myelogenous leukaemia. It could not be determined from these studies whether the DAB oxidation product was demonstrating a single hydroperoxidase, catalase or myeloperoxidase, or both. In the present study, immunofluorescence techniques for the two hydroperoxidases were applied in an attempt to identify this activity specifically. The results obtained indicate that myeloperoxidase is present in the phi bodies and rods, and that this enzyme may be the major or the only hydroperoxidase present. Its activity could account for the peroxidation of DAB under conditions which are more favourable for the demonstration of catalase.
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Abstract
The initial latency of spikes evoked by click stimulation and the duration over which spiking occurred were observed in the inferior colliculi of rats. One ear of these animals had been deprived of early auditory stimulation by ligation of the external meatus. Clicks presented to the normally experienced ears evoked spikes in the opposite colliculus with latencies that depended on the characteristic frequency of the unit. Low-frequency (less than 5 kHz) units had latencies from 6-10 msec. Latencies declined to 3-4 msec for high frequency (greater than 20 kHz) units. After an ear had been deprived of sound from 10 days after birth, response latencies of units in the opposite colliculus with characteristic frequencies below about 10 kHz were comparable to controls, but most units above 10 kHz had latencies 2-3 times control latencies. Spike activity evoked in these units did not continue as long as that for most comparable control units. Ears sound deprived for an equal period from 60 days after birth also had changes in latencies and response durations, but these were much less than in the developmentally deprived. Latencies of gross potentials at the auditory nerve were not affected by early deprivation, indicating a central origin for the latency changes.
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Abstract
Human saliva was tested for the presence of factors that affect the complement system. Parotid saliva and salivary fractions were incubated at 37 C with human serum as a source of complement. Samples removed from the mixtures within the first 15 minutes had higher levels of whole hemolytic complement activity than did appropriate controls. The final ionic strength of the saliva-serum mixtures was critical to the hemolytic activity of complement. After 60 minutes all serum-saliva mixtures had lower levels of hemolytic activity than did serum-buffer controls. With regard to whole saliva, the salivary sediment was found to be strongly complement-reactive.
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Hanker JS, Silverman MS, Romanovicz DK. Catalase in salivary gland striated and excretory duct cells. II. phi body: an ellipsoidal peroxisomal organelle with crystalloid axial projections. Histochem J 1977; 9:729-44. [PMID: 924809 DOI: 10.1007/bf01003067] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
A new distinctive and unique peroxisomal organelle with a spindle shape has been observed in luminal epithelial cells of striated and excretory ducts of mouse salivary glands. Light microscopic studies indicate it has an ellipsoidal centre from which catalase-positive filamentous or rod-like processes protrude along its major axis; hence, it is called a phi body. A role for this specialized peroxisome in the formation of nearby free filaments and rods is suggested by the frequent observation of segmentation of its axial processes. Complementary ultrastructural studies of osmium-fixed preparations show that the deformation to an oval shape results from the pressure of the extruding crystalloid coincident with the major axis of the ellipsoidal body. The size range and conformation of phi body axial processes are comparable to those of free catalase-positive rods and filaments observed in the same cells. The periodic substructure of the crystalloid in the phi body core is identical with that of nearby cytoplasmic rods. These observations are consistent with the view that the rods and filaments observed free in the cytoplasm are formed by extrusion from the crystalloid core of the phi body. phi Bodies could also be responsible for the Aver rods of leukemic leukocytes.
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Abstract
Fifty-six neonatally thymectomized and 41 neonatally sham-operated female golden hamsters (Mesocricetus auratus) were divided into 2 groups, one inoculated with Actinomyces (N16) and the other not inoculated. All animals were raised and maintained on a high sucrose, soft diet (Diet 2000) and water, ad libitum. White blood cell counts, differentials and total lymphocyte counts were determined at 4 to 5 weeks of age. The rejection of albino hamster skin grafts and the hemagglutination response to sheep red blood cells (SRBC) were used to determine inhibition of T lymphocyte function. Evaluation of alveolar bone loss at the end of 160 days indicated that the thymectomized animals with a significant depression of the hemagglutination response to SRBC and a lack of skin graft rejections had a significantly higher bone loss than sham-operated animals. This suggests that the cellular immune response plays a role in the periodontal syndrome in hamsters. Further investigation is necessary to establish how significant this role is in relationship to the numerous other factors that are present. These data suggest that the role of the cellular immune response in the hamster periodontium may be protective rather than destructive. The role of Actinomyces (N16) in the development of bone loss was not significant.
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Bengry MF, Silverman MS, Clopton BM. Effects of lesioning the dorsal and intermediate acoustic striae on binaural interaction at the inferior colliculus. Exp Brain Res 1977; 28:211-9. [PMID: 881004 DOI: 10.1007/bf00237097] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Contralateral clicks normally activate units in the inferior colliculus of rats. Ipsilateral clicks usually inhibit this activity when their intensity just exceeds the contralateral intensity. When the contralateral dorsal and intermediate acoustic striae are lesioned as they pass over the restiform body, ipsilateral clicks inhibit even if they are substantially less intense than contralateral clicks. Contralateral click thresholds for unit activation are elevated by about 10 dB, but this shift in sensitivity cannot account for the marked advantage gained by the ipsilateral inhibitory input. These findings suggest that one or both of these pathways contributes heavily to binaural interaction at the inferior colliculus.
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Courts FJ, Boackle RJ, Fudenberg HH, Silverman MS. Detection of functional complement components in gingival crevicular fluid from humans with periodontal diseases. J Dent Res 1977; 56:327-31. [PMID: 323317 DOI: 10.1177/00220345770560032001] [Citation(s) in RCA: 56] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Crevicular fluid was collected from patients with periodontitis by a capillary tube procedure. Complement component activities were determined by functional assay systems, with human complement, and partially purified human first complement component (C1) as controls. The complement-fixing properties of the dental plaque of each patient were also examined C1 activity in the crevicular fluid of all patients was approximately 1/8 of whole serum C1 and diminished rapidly with time after collection. There was no significant relationship between C1 concentration and crevicular fluid flow rate. Hemolytic activity of whole complement was also invariable detected when sufficient amounts (8 micronl) of crevicular fluid could be obtained. Dental plaque was found to fix C1. A role for crevicular complement in inflammatory periodontal disease is suggested.
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Boquet P, Silverman MS, Pappenheimer AM, Vernon WB. Binding of triton X-100 to diphtheria toxin, crossreacting material 45, and their fragments. Proc Natl Acad Sci U S A 1976; 73:4449-53. [PMID: 63947 PMCID: PMC431494 DOI: 10.1073/pnas.73.12.4449] [Citation(s) in RCA: 117] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Binding of the nonionic detergent [3H]Triton X-100 by diphtheria toxin, by the nontoxic serologically related protein crossreacting material (CRM) 45, and by their respective A and B fragments has been studied. If first denatured in 0.1% sodium dodecyl sulfate, all of the proteins with the exception of fragment A bind increasing amounts of Triton X-100, reaching a maximum of more than 40 mol bound per mol of protein when the detergent concentration exceeds its critical micelle concentration. No measurable amount of Triton X-100 is bound by native toxin or its A fragment of any concentration of the detergent. Undenatured CRM45 or its B45 fragment, on the other hand, readily became inserted into Triton X-100 micelles when the detergent reaches its critical micelle concentration. The results show that the toxin molecule contains a hydrophobic domain located on the portion of the B fragment that is linked to A. This region is masked in native toxin. Based on these findings, a model is proposed to describe how fragment B facilitates the transport of the enzymically active hydrophilic fragment A across the plasma membrane to reach the cytoplasm.
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