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Freund O, Rotem-Green M, Rahat M, Gershman E, Ophir N, Fireman E, Shenhar-Tsarfaty S, Bar-Shai A. Nanoparticles in induced sputum - a window to airway inflammation among active smokers. Nanomedicine (Lond) 2023; 18:303-315. [PMID: 36975802 DOI: 10.2217/nnm-2022-0269] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/29/2023] Open
Abstract
Aims: To evaluate the role of nanoparticles (NP) in sputum samples of active smokers as markers of inflammation and disease. Materials & methods: 29 active smokers were included (14 with chronic obstructive pulmonary disease [COPD]) and underwent clinical assessment, pulmonary function tests, sputum induction (with NP analysis) and blood sampling. Results: Higher particle and NP concentrations and smaller mean size directly correlated with clinical parameters such as the COPD Assessment Test score and impulse oscillometry results. Similar correlations were found between NPs and increased sputum IL-1β, IL-6 and TNF-α. Among COPD patients, higher IL-8 and lower IL-10 serum levels also correlated with NP concentrations. Conclusion: This proof-of-concept study shows the potential of sputum NPs as markers of airway inflammation and disease.
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Affiliation(s)
- Ophir Freund
- The Institute of Pulmonary Medicine, Tel-Aviv Sourasky Medical Center & Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, 6423906, Israel
| | - Michal Rotem-Green
- The Institute of Pulmonary Medicine, Tel-Aviv Sourasky Medical Center & Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, 6423906, Israel
| | - Maya Rahat
- The Institute of Pulmonary Medicine, Tel-Aviv Sourasky Medical Center & Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, 6423906, Israel
| | - Evgeni Gershman
- The Institute of Pulmonary Medicine, Tel-Aviv Sourasky Medical Center & Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, 6423906, Israel
| | - Noa Ophir
- The Institute of Pulmonary Medicine, Tel-Aviv Sourasky Medical Center & Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, 6423906, Israel
| | - Elizabeth Fireman
- The Institute of Pulmonary Medicine, Tel-Aviv Sourasky Medical Center & Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, 6423906, Israel
| | - Shani Shenhar-Tsarfaty
- Internal Medicine C, Tel Aviv Sourasky Medical Center & Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, 6423906, Israel
| | - Amir Bar-Shai
- The Institute of Pulmonary Medicine, Tel-Aviv Sourasky Medical Center & Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, 6423906, Israel
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Van Ameringen M, Patterson B, Turna J, Lethbridge G, Goldman Bergmann C, Lamberti N, Rahat M, Sideris B, Francisco A, Fineberg N, Pallanti S, Grassi G, Vismara M, Albert U, Gedanke Shavitt R, Hollander E, Feusner J, Rodriguez C, Morgado P, Dell’Osso B. Obsessive-compulsive disorder during the COVID-19 pandemic. J Psychiatr Res 2022; 149:114-123. [PMID: 35272208 PMCID: PMC8872360 DOI: 10.1016/j.jpsychires.2022.02.001] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/30/2021] [Accepted: 02/07/2022] [Indexed: 01/09/2023]
Affiliation(s)
- M. Van Ameringen
- Department of Psychiatry and Behavioural Neurosciences, McMaster University, Canada,MacAnxiety Research Centre, McMaster University, Canada,Corresponding author. Dept of Psychiatry and Behavioural Neurosciences, McMaster University. MacAnxiety Research Centre, 1057 Main St. W, #L02, Hamilton, ON, L8S 1B7, Canada
| | - B. Patterson
- Department of Psychiatry and Behavioural Neurosciences, McMaster University, Canada,MacAnxiety Research Centre, McMaster University, Canada
| | - J. Turna
- MacAnxiety Research Centre, McMaster University, Canada
| | - G. Lethbridge
- MacAnxiety Research Centre, McMaster University, Canada
| | - C. Goldman Bergmann
- Department of Psychiatry and Behavioural Neurosciences, McMaster University, Canada,MacAnxiety Research Centre, McMaster University, Canada
| | - N. Lamberti
- MacAnxiety Research Centre, McMaster University, Canada
| | - M. Rahat
- MacAnxiety Research Centre, McMaster University, Canada
| | - B. Sideris
- MacAnxiety Research Centre, McMaster University, Canada
| | | | - N. Fineberg
- National Obsessive Compulsive Disorders Treatment Service, Hertfordshire Partnership NHS Foundation Trust, Queen Elizabeth II Hospital, University of Hertfordshire, Postgraduate Medical School, UK
| | - S. Pallanti
- Institute of Neuroscience, Università di Firenze, Italy
| | | | - M. Vismara
- Department of Mental Health, Department of Biomedical and Clinical Sciences Luigi Sacco, University of Milan, Italy
| | - U. Albert
- Università degli Studi di Torino, Dipartimento di Neuroscienze, Italy
| | - R. Gedanke Shavitt
- OCD Spectrum Disorders Program, Institute and Department of Psychiatry, Hospital das Clinicas da Faculdade de Medicina da Universidade de Sao Paulo, Brazil
| | - E. Hollander
- Department of Psychiatry and Behavioral Sciences, Albert Einstein College of Medicine, Montefiore Medical Center, USA
| | - J. Feusner
- Department of Psychiatry University of Toronto, Canada
| | - C.I. Rodriguez
- Department of Psychiatry and Behavioural Sciences, Stanford University, USA
| | - P. Morgado
- Life and Health Sciences Research Institute (ICVS), School of Medicine, University of Minho, Portugal
| | - B. Dell’Osso
- Department of Mental Health, Department of Biomedical and Clinical Sciences Luigi Sacco, University of Milan, Italy,“Aldo Ravelli” Center for Neurotechnology and Brain Therapeutic, University of Milan, Italy
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Affiliation(s)
- Ashraf Imam
- Department of Surgery, Kaplan Medical Center, Rehovot, Israel
| | - Harbi Khalayleh
- Department of Surgery, Kaplan Medical Center, Rehovot, Israel
| | - Maya Rahat
- Department of Surgery, Kaplan Medical Center, Rehovot, Israel
| | - Eli Mavor
- Department of Surgery, Kaplan Medical Center, Rehovot, Israel
| | - Guy Pines
- Department of Surgery, Kaplan Medical Center, Rehovot, Israel
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Waisman D, Brod V, Weber G, Lavon O, Popovski F, Vasilenko I, Rahat M, Lahat N, Bitterman H. DOSE-RELATED EFFECTS OF HYPEROXIA ON THE PULMONARY INFLAMMATORY RESPONSE IN SEPSIS INDUCED BY CECAL LIGATION AND PUNCTURE. Shock 2006. [DOI: 10.1097/00024382-200606001-00121] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Bornstein J, Shapiro S, Rahat M, Goldshmid N, Goldik Z, Abramovici H, Lahat N. Polymerase chain reaction search for viral etiology of vulvar vestibulitis syndrome. Am J Obstet Gynecol 1996; 175:139-44. [PMID: 8694039 DOI: 10.1016/s0002-9378(96)70263-6] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.1] [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: 02/01/2023]
Abstract
OBJECTIVE Our purpose was to assess the prevalence of infections by human papillomavirus, herpes simplex virus, and cytomegalovirus among women with severe vulvar vestibulitis. STUDY DESIGN Eighty-six women referred for dyspareunia and diagnosed as having severe vestibulitis underwent perineoplasty, including surgical removal of the sensitive vestibule. Controls included 25 age-matched patients without dyspareunia undergoing vaginal operations for various benign causes or undergoing repair of an episiotomy. Polymerase chain reaction analysis was carried out to determine the presence of viral genes. RESULTS The prevalence of herpes simplex virus and cytomegalovirus among the subjects tested was nil, whereas human papillomavirus was detected in 46 cases (54%). The human papillomavirus present was not of types 6, 11, 16, 18, or 33. Only one woman of the 25 asymptomatic controls (4%) had human papillomavirus deoxyribonucleic acid in the vestibule (p < 0.001). CONCLUSION Our data provide support for the idea that vulvar vestibulitis is associated with human papillomavirus deoxyribonucleic acid in more than half of cases.
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Affiliation(s)
- J Bornstein
- Department of Obstetrics and Gynecology, Carmel Medical Center, Haifa, Israel
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Abstract
Host/symbiont specificity has been investigated in non-symbiotic and aposymbiotic brown and green hydra infected with various free-living and symbiotic species and strains of Chlorella and Chlorococcum. Morphology and ultrastructure of the symbioses obtained have been compared. Aposymbiotic Swiss Hydra viridis and Japanese H. magnipapillata served as controls. In two strains of H. attenuata stable hereditary symbioses were obtained with Chlorococcum isolated from H. magnipapillata. In one strain of H. vulgaris, in H. oligactis and in aposymbiotic H. viridis chlorococci persisted for more than a week. Eight species of free-living Chlorococcum, 10 symbiotic and 10 free-living strains of Chlorella disappeared from the brown hydra within 1–2 days. In H. magnipapillata there was a graded distribution of chlorococci along the polyps. In hypostomal cells there were greater than 30 algae/cell while in endodermal cells of the mid-section or peduncle less than 10 algae/cell were found. In H. attenuata the algal distribution was irregular, there were up to five chlorocci/cell, and up to 20 cells/hydra hosted algae. In the dark most cells of Chlorococcum disappeared from H. magnipapillata and aposymbiotic hydra were obtained. Chlorococcum is thus an obligate phototroph, and host-dependent heterotrophy is not required for the preservation of a symbiosis. The few chlorococci that survived in the dark seem to belong to a less-demanding physiological strain. In variance with known Chlorella/H. viridis endosymbioses the chlorococci in H. magnipapillata and H. attenuata were tightly enveloped in the vacuolar membrane of the hosting cells with no visible perialgal space. Chlorococcum reproduced in these vacuoles and up to eight daughter cells were found within the same vacuole. We suggest that the graded or scant distribution of chlorococci in the various brown hydra, their inability to live in H. viridis and the inability of the various chlorellae to live in brown hydra are the result of differences in nutrients available to the algae in the respective hosting cells. We conclude that host/symbiont specificity and the various forms of interrelations we show in green and brown hydra with chlorococci and chlorellae are based on nutritional-ecological factors. These interrelations demonstrate successive stages in the evolution of stable obligatoric symbioses from chance encounters of preadapted potential cosymbionts.
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Affiliation(s)
- M Rahat
- Department of Zoology, Hebrew University of Jerusalem, Israel
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Abstract
Aposymbiotic polyps of Hydra viridis were infected with one or two of the following strains of Chlorella: the native strain obtained from green H, viridis, and the originally non-symbiotic strains Fs and 211/8p cultured in vitro. Larvae of Artemia served as infecting vectors. Chimeric infections were obtained with two different Chlorella strains cohabiting in the same cells and polyps. In time, the chimeric infections disappeared and mixed populations of Hydra were formed with different strains of Chlorella in different polyps. We suggest that the Chlorella/Hydra symbiosis was initiated originally by an infection of preadapted hydra by preadapted chlorellae. Through intracellular interalgal competition and competition between dissimilar infected cells and polyps, the present-day stable symbiosis has evolved.
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Rahat M, Reich V. Correlations between characteristics of some free-living Chlorella sp. and their ability to form stable symbioses with Hydra viridis. J Cell Sci 1985; 74:257-66. [PMID: 4030909 DOI: 10.1242/jcs.74.1.257] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Aposymbiotic polyps of Hydra viridis were infected with 17 strains of in vitro cultured Chlorella sp. Larvae of Artemia fed with the chlorellae were used as an infecting vector. Of the 17 strains, seven formed stable symbioses and one formed a transient infection that disappeared within several weeks. Chlorellae of the nine other strains were cleared out of the infected hydra within 2–3 days. There was a distinct correlation between the ability of the chlorellae to form stable symbioses and their ability to adapt and grow in media enriched with 0.5% proteose peptone. Only strains that grew in the latter medium formed symbioses with the hydra. The symbioses formed with the different strains of chlorellae differed from one another. Hydra infected with some strains greened completely while those infected with other strains greened only partially. The degree of infection varied also within each population, and there were differences in the distribution of the various chlorellae along the stalk and inside the digestive cells of the hydra. Growth rates of the infected hydra were all less that those of aposymbiotic hydra or of hydra hosting native zoochlorellae. We conclude that adaptability to a nutrient-rich environment inside the perialgal vacuole of the digestive cell and a sufficient growth rate therein are crucial to the ability of chlorellae to form stable symbioses with H. viridis. In time, co-adaptation of hydra and chlorellae would restore the normal growth rate of the former and bring about regularity to the form and extent of infection by the latter.
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Rahat M, Reich V. Intracellular infection of aposymbiotic Hydra viridis by a foreign free-living Chlorella sp.: initiation of a stable symbiosis. J Cell Sci 1984; 65:265-77. [PMID: 6715427 DOI: 10.1242/jcs.65.1.265] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
An aposymbiotic strain of Hydra viridis became infected with free-living Chlorella sp. A stable symbiosis formed that differed in its characteristics from other known Chlorella/Hydra symbioses. The algae reproduced and formed clusters in host endodermal cells, inside large vacuoles filled with an electron-dense substance. A few algae were found to be digested by the hydra, but the apparently uncontrolled reproduction rate of the algae more than compensated for this loss. Surplus algae were expelled into the coelenteron and eventually into the surrounding medium. The expelled algae were repeatedly re-engulfed by the hydra during its feeding, forming a process of continuous reinfection. We suggest that such repeated reinfection of the hydra by the expelled algae provides the host with an endless number of Chlorella from which it might in time select a suitable adapted, controllable symbiont. The present newly formed symbiosis might serve as a model for the study of evolution of algal endosymbioses.
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Abstract
Bacteria-free hydra, cultured in sterile media, were fed bacteria-free larvae of Artemia salina. Normal growth and budding were obtained in symbiotic and aposymbiotic Hydra viridis. Two nonsymbiotic hydra species did not form buds under bacteria-free conditions. When these hydra were fed nonsterile Artemia, or if the medium was reinoculated with bacteria isolated from budding stock cultures, normal budding was resumed. An exogenous budding factor, which can be provided by nonsterile Artemia larvae, or even by some bacteria, appears to be required by these nonsymbiotic hydra. This factor is endogenous in Hydra viridis.
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Guy M, Reinhold L, Rahat M, Seiden A. Protonation and light synergistically convert plasmalemma sugar carrier system in mesophyll protoplasts to its fully activated form. Plant Physiol 1981; 67:1146-50. [PMID: 16661825 PMCID: PMC425850 DOI: 10.1104/pp.67.6.1146] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/09/2023]
Abstract
The course of sugar fluxes into and out of protoplasts isolated from the mesophyll of Pisum sativum L. has been followed over brief time intervals (minutes). Light strongly stimulated net sugar influx at pH 8 as well as at pH 5.5. The proton conductor carbonyl cyanide m-chlorophenylhydrazone (CCCP) inhibited initial influx in the light, both at pH 8.0 and at pH 5.5. CCCP was without effect in the dark at either pH. All these results applied both to sucrose and to the nonmetabolizable glucose analog 3-O-methyl-d-glucose.When protoplasts at pH 5.5 were transferred from light to darkness, "stored" light driving force maintained uptake in the dark at the full light rate for the first 7 minutes. At pH 8, however, even 4 minutes after transfer to dark, uptake was well below the light rate. Initial uptake rates over a range of external concentrations were derived from progress curves obtained in the light and in the dark, both at pH 5.5 and at 7.7. When initial rate was plotted against concentration, simple Michaelis-Menten kinetics were observed only under the condition pH 5.5, light. In the dark at both pH values, and in the light at pH 7.7, complex curves with intermediate plateaus were obtained, strongly resembling curves reported for systems where mixed negative and positive cooperativity is operating.The same "K(m) for protons" was observed in the dark and in the light (10(-7) molar). Switching protoplasts in the dark from pH 8 to 5.5 failed to drive sugar transport by imposed protonmotive force, as judged by lack of sensitivity to CCCP. Switching protoplasts which had taken up sugar in the dark at pH 5.5 to pH 7 induced net efflux of sugar. Flux analysis showed that this effect was entirely due to the prompt fall in influx.It is concluded from the kinetic experiments that protonation alone is not sufficient to convert the sugar transport system to its fully activated high affinity form. A further light-dependent factor which acts synergistically with protonation is required.
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Affiliation(s)
- M Guy
- Department of Botany, The Hebrew University of Jerusalem, Israel
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Guy M, Reinhold L, Rahat M. Energization of the sugar transport mechanism in the plasmalemma of isolated mesophyll protoplasts. Plant Physiol 1980; 65:550-3. [PMID: 16661233 PMCID: PMC440374 DOI: 10.1104/pp.65.3.550] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/09/2023]
Abstract
The mechanism of 3-O-methyl-d-glucose transport through the plasmalemma has been investigated in protoplasts isolated from the mesophyll of Pisum sativum L. var. Dan.Analysis of the fluxes after 50 minutes of uptake showed that the gradual decrease in slope of the net uptake curve with time was not due to any decline in uptake capacity; it represented the approach to flux equilibrium of a small compartment of the protoplast, probably the cytoplasm.The energy of activation for initial flux into this compartment was 20 kilocalories per mole between 17 and 27 C. Very high discrimination was shown with regard to sugar isomers. Light strongly promoted flux (by a factor of 2.5 in the case of methyl glucose). Initial flux showed sharply contrasting inhibitor sensitivity in the light and the dark. Light uptake was sensitive to the proton conductor carbonyl cyanide m-chlorophenylhydrazone (CCCP), but stable for at least the first 10 minutes to the ATPase inhibitors quercetin, rutin, and diethylstilbestrol, as well as to arsenate. Dark uptake, on the other hand, was stable to CCCP but was immediately depressed by quercetin, rutin, diethylstilbestrol, and arsenate.Protoplasts which received a light pretreatment before incubation in the dark took up methyl glucose at the accelerated light rate for the first 7 minutes. Moreover, the light pretreatment sensitized subsequent initial dark uptake to CCCP, and conferred on it the stability to ATPase inhibitors and arsenate characteristic of light uptake. After about 7 minutes the characteristic inhibitor responses of dark uptake were resumed.It is proposed that more than one mode of energy-coupling for sugar transport may operate in these protoplasts.
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Affiliation(s)
- M Guy
- Department of Botany, The Hebrew University of Jerusalem, Israel
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Rahat M, Zeldes D, Reich V. Photoproducts of chloramphenicol: Their cytotoxic effects on hydra viridis and its symbiotic algae. ACTA ACUST UNITED AC 1979. [DOI: 10.1016/0306-4492(79)90125-4] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Bergmann F, Levene L, Tamir I, Rahat M. Oxidation of methyl derivatives of pteridin-4-one, lumazine and related pteridines by bovine milk xanthine oxidase. Biochim Biophys Acta 1977; 480:21-38. [PMID: 12825 DOI: 10.1016/0005-2744(77)90317-5] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
1. Pteridin-4-ones, methylated at nitrogen or carbon, N-methylated lumazines and related oxopteridines were studied as substrates of a highly purified bovine milk xanthine oxidase (xanthine : oxygen oxidoreductase, EC 1.2.3.2). 2. The enzyme can oxidise at high rates both uncharged and anionic substrates. Variation of enzymic activity with pH is mainly due to pH-dependent changes in the active enzymic center. 3. Milk xanthine oxidases at different stages of purification convert pteridin-4-one into the 4,7-dione (compound 13 in this article). 4. Methylation at C-6 in the pyrazine moiety enhances enzymic attack at C-2 in the pyrimidine ring. N-Methylation may increase or reduce rates of oxidation. 5. For oxidation at C-2, the most favorable form of the substrate bears a double bond at C(2) = N(3). Attack at C-7 is enhanced strongly in structures bearing a double bond at C(6) = C(7). 6. In general, pteridines react with xanthine oxidase as non-hydrated molecules. However, oxidation of 8-methyllumazine at C-7 may take place by dehydrogenation of the 7-CHOH group of the covalently hydrated molecule.
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Hawkes RB, Rahat M. Contraction and volume reduction of the glycerolatedCarchesium spasmoneme: Effects of alkali earth cations. ACTA ACUST UNITED AC 1976. [DOI: 10.1007/bf01937741] [Citation(s) in RCA: 9] [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: 11/30/2022]
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Abstract
The effect of colchicine on stalk elongation in the colonial peritrich ciliate Carchesium sp. has been investigated by growing this protozoon in colchicine-containing media. The length of the stalk in control cultures was 0-4-0-9 mm. In the presence of 2-5-12-5 mM colchicine, stalk elongation was inhibited, and stalk length was inversely proportional to colchicine concentration. At concentrations above 7-5 mM colchicine, stalks measured less than 0-1 mm, and sometimes contained imperfect myonemes. The rate of cell fission was retarded in colchicine-containing media, but nevertheless short-stalked colonies with apparently normal zooids were formed. On transfer of such colonies to media without colchicine normal growth was resumed, but only the newly formed branches were of normal length and contractility. The inhibitory effect of colchicine was annulled by Ca2+ and Mg2+ at 10(−3) and 10(−4) M, respectively. At lower concentrations of Mg2+, but in the presence of Ca2+, the effect of colchicine was less conspicuous than at low Ca2+ concentration in presence of Mg2+. Lowering Mg2+ concentration at low Ca2+ concentration, increased the inhibitory effect of colchicine. It is concluded that colchicine-sensitive, probably tubulin-like proteins, participate in the formation of the contractile stalk of Carchesium. Ca2+ and Mg2+ probably compete with colchicine for a common site in these proteins, or they might reduce the cell's permeability to this drug.
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Campbell RD, Rahat M. Ultrastructure of nematocytes and one-celled tentacles of the freshwater coelenterate, Calpasoma dactyloptera. Cell Tissue Res 1975; 159:445-57. [PMID: 238744 DOI: 10.1007/bf00221702] [Citation(s) in RCA: 5] [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: 12/13/2022]
Abstract
Calpasoma dactyloptera, a tentacled form of minute, freshwater coelenterate, has been investigated by light and electron microscopy and time-lapse cinematography. Each tentacle consists of a protrusion from a single ectodermal epithelial cell termed a tentaculocyte. Thus, unlike most coelenterate tentacles, neither mesoglea nor endoderm is present in the tentacle. Large numbers of nematocytes are present, however. When the nematocytes are poised, they sit within tentaculocyte vesicles which represent invaginations of the plasma membrane. A cnidocil protrudes into the external medium. The bottom of each nematocyte is elongated as a stalk which extends to the tentacle base, coursing through tubular membrane lined channels within the tentaculocyte. A network of fibers and microtubules, originating in the cnidocil, extends to the base of the nematocyte stalk.
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Rahat M, Campbell RD. Three forms of the tentacled and non-tentacled fresh-water coelenterate polyp genera Craspedacusta and Calpasoma. Trans Am Microsc Soc 1974; 93:235-41. [PMID: 4151596] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
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Schönfeld M, Rahat M, Neumann J. Photosynthetic Reactions in the Marine Alga Codium vermilara: I. CO(2) Fixation and Hill Reaction in Isolated Chloroplasts. Plant Physiol 1973; 52:283-7. [PMID: 16658548 PMCID: PMC366486 DOI: 10.1104/pp.52.3.283] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/09/2023]
Abstract
Chloroplasts were isolated from the marine alga Codium vermilara (Siphonales). The isolated chloroplasts were active in CO(2) fixation in the light at a rate comparable to the rates obtained by fragments of thalli. Maximal rates of CO(2) fixation by isolated chloroplasts from Codium were obtained in the presence of salt or sorbitol isoosmotic with sea water. The conditions of isolation of Codium chloroplasts are much less stringent than those required for active chloroplasts from higher plants. The isolated chloroplasts comprise a homogeneous population of the intact "class I" type, as based on microscopic observations and on their inability to reduce ferricyanide unless osmotically shocked. The intact chloroplasts are able to reduce p-benzoquinone at a high rate.
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Affiliation(s)
- M Schönfeld
- Department of Botany, Tel-Aviv University, Tel-Aviv, Israel, and Department of Zoology, The Hebrew University, Jerusalem, Israel
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Ziv E, Hochberg A, Degroot N, Rahat M. Competition of ethionine and methionine for aminoacyl-tRNA formation in an in vitro system from Ochromonas danica. J Protozool 1973; 20:153-6. [PMID: 4690647 DOI: 10.1111/j.1550-7408.1973.tb06023.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
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Paster Z, Reich K, Bergmann F, Rahat M. Studies on the growth of Prymnesium parvum Carter (chrysomonadina) and on the formation of its toxin (prymnesin). Experientia 1966; 22:790-1. [PMID: 5973210 DOI: 10.1007/bf01897415] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
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