Tikvah Alper (22 January 1909 – 2 February 1995) trained as a physicist and became a distinguished radiobiologist.[1] Among many other initiatives and discoveries, she was among the first to find evidence indicating that the infectious agent in Scrapie does not contain nucleic acid: a finding that was instrumental in understanding the development of the Prion theory.[2] She was director of the MRC Experimental Radiopathology Unit, Hammersmith Hospital, London, UK, 1962–1974.
Tikvah Alper was born in South Africa, the youngest of four daughters in a family of Jewish refugees from Russia.[3] As a schoolgirl at Durban Girls' High School, she was described as "the most intellectually distinguished girl ever to attend the school",[4] and matriculated with distinction a year early. She graduated with distinction in physics from University of Cape Town in 1929, and then studied in Berlin with the nuclear physicist Lise Meitner in 1930–32, publishing a prize-winning[4] paper on delta rays produced by alpha particles in 1933.[5] In 1932, she returned to South Africa to marry the (later) renowned bacteriologist Max Sterne,[6] the inventor of the most effective livestock vaccine for anthrax. Because married women were not then permitted to work at University, Tikvah and Max established a home laboratory where they worked together. Their sons, Jonathan and Michael, were born in 1935 and 1936. From then on, Tikvah Alper combined demands of motherhood (Jonathan was born profoundly deaf), marriage and career. These included pre- and post-war spells in England, where she worked with the pioneer radiobiologist, Douglas Lea.[7] Over ten years from 1937, Tikvah retrained and then also worked as a teacher of the deaf. Her physics training and technical skills were evident in her published research on making speech articulation visible, for use in speech training for deaf children[8] She became head of the Biophysics section of the South African National Physics Laboratory in 1948.
Later careeredit
Despite their growing scientific renown, in 1951, Max Sterne and Tikvah Alper were forced to leave South Africa because of their outspoken opposition to apartheid. Tikvah found an (unpaid) research post at the MRC Radiobiology Laboratories at the Hammersmith Hospital, London, directed by Hal Gray, whom she had met on earlier visits. Here, work focussed on the mechanisms of the effects of radiation on cell biology. The complexities of the effects of radiation on different cell types, and their interaction with other physiological and chemical processes began to be mapped out at this time, and continued through the 1950s and 60s. She was Director of the Radiobiology Unit from 1962 until her retirement in 1974. Her classic text Cellular Radiobiology[9] was published in 1979. Tikvah Alper continued an active professional life in retirement, culminating in a "brilliant lecture to the Radiation Research Society in Dallas, USA at the age of 83..".[4][10] She died in Sarisbury, Hampshire, England, in 1995,[11] and was survived by her husband Max, sons Jonathan and Michael, six grandchildren, and three great-grandchildren.
Alper's role in identifying the infectious agent in Scrapieedit
Scrapie is a fatal infectious disease of the neural system of sheep; one of a class of brain diseases that can affect cattle (BSE) and humans (Kuru, nCJD). Scrapie had been thought to be caused by a 'slow virus' – one that could take years to show as a change in behaviour or movement. By the mid-1960s, it was established that cells could only replicate via DNA. Radioactivity stops cell replication by 'killing' DNA. Alper found that radiation did not kill the infective agent in scrapie, suggesting that a virus was unlikely to be the infective agent. The infective agent had to be smaller and simpler than (viral) DNA. Alper also found that the agent remained active under ultraviolet light. DNA is inactive under UV light. Instead, the agent was killed by light at 237 nm, a wavelength specific to polysaccharide inactivation. Alper and colleagues[12] reported these properties of the scrapie agent – a finding that was greeted with astonishment in many quarters, for it appeared to contravene the central dogma that holds that replication (and hence the growth of the disease and its infectious properties) can only proceed via DNA. However, once these empirical findings were accepted, several theories developed to accommodate the peculiar properties of the scrapie agent. The most widely accepted theory today is the prion theory, which posits a 'rogue' protein as the infectious source. However, Alper could not accept that a protein 'mutation' was the agent. Firstly, her UV radiation studies did not indicate a protein agent and, secondly, isolated prions did not induce scrapie. Her own theories concerning the agent were developed in the last years of her life and suggested a more dynamic and complex story.[13]
^Hunter, A (2012). "Radiation biology – An important science". South African Journal of Science. 108 (7/8): 972. doi:10.4102/sajs.v108i7/8.972. hdl:11427/29930.
^Highfield, Roger, . The Telegram. 11 February 2011
^Vogt, Annette B. "Tikvah Alpert 1909-1995". Jewish Women's Archive Encyclopedia. Jewish Women's Archive. Retrieved 17 December 2016.
^Alper, T (1932). "Über die δ-Strahlen und die Beziehung zwischen Reichweite und Geschwindigkeit für langsame Elektronen". Zeitschrift für Physik. 76 (3–4): 172–189. Bibcode:1932ZPhy...76..172A. doi:10.1007/BF01341810. S2CID 122840914.
^"Obituary: Max Sterne". The Independent. 4 March 1997. Archived from the original on 7 May 2022. Retrieved 27 October 2017.
^Alper, T.; Zimmerman, H. J. (1939). "A thyraton inflexion indicator for teaching the deaf". Journal of Scientific Instruments. 16 (10): 334–6. Bibcode:1939JScI...16..334S. doi:10.1088/0950-7671/16/10/304.
^Alper, Tikvah, Cellular Radiobiology. CUP Archive, 1979.
^Alper, T (1993) The Scrapie Enigma: insights from radiation experiments Radiation Research 135, 283–92
^Alper, T.; et al. (1967). "Does the agent of scrapie replicate without Nucleic Acid?". Nature. 214 (5090): 764–766. Bibcode:1967Natur.214..764A. doi:10.1038/214764a0. PMID 4963878. S2CID 4195902.
^Alper, T. (July 1992). "The infectivity of spongiform encephalopathies: does a modified membrane hypothesis account for lack of immune response?". FEMS Microbiology Letters. 4 (5): 235–242. doi:10.1111/j.1574-6968.1992.tb05000.x. PMID 1355344.
January 01, 1970
tikvah, alper, january, 1909, february, 1995, trained, physicist, became, distinguished, radiobiologist, among, many, other, initiatives, discoveries, among, first, find, evidence, indicating, that, infectious, agent, scrapie, does, contain, nucleic, acid, fin. Tikvah Alper 22 January 1909 2 February 1995 trained as a physicist and became a distinguished radiobiologist 1 Among many other initiatives and discoveries she was among the first to find evidence indicating that the infectious agent in Scrapie does not contain nucleic acid a finding that was instrumental in understanding the development of the Prion theory 2 She was director of the MRC Experimental Radiopathology Unit Hammersmith Hospital London UK 1962 1974 Tikvah AlperBorn 1909 01 22 22 January 1909Wynberg Cape TownDied2 February 1995 1995 02 02 aged 86 Sarisbury Hampshire EnglandEducationM A doctoral studies cut short by leaving Germany Alma materUniversity of Cape TownKaiser Wilhelm Institute for ChemistryKnown forresearch on the infectious agent in Scrapie made notable during the Mad cow disease outbreak in Britain in the 1990sSpouseMax Sterne 1906 1994 Children2Scientific careerInstitutionsUniversity of the WitwatersrandHammersmith HospitalDoctoral advisorLise Meitner She married Max Sterne but never adopted his name Contents 1 Early life and career 2 Later career 3 Alper s role in identifying the infectious agent in Scrapie 4 See also 5 ReferencesEarly life and career editTikvah Alper was born in South Africa the youngest of four daughters in a family of Jewish refugees from Russia 3 As a schoolgirl at Durban Girls High School she was described as the most intellectually distinguished girl ever to attend the school 4 and matriculated with distinction a year early She graduated with distinction in physics from University of Cape Town in 1929 and then studied in Berlin with the nuclear physicist Lise Meitner in 1930 32 publishing a prize winning 4 paper on delta rays produced by alpha particles in 1933 5 In 1932 she returned to South Africa to marry the later renowned bacteriologist Max Sterne 6 the inventor of the most effective livestock vaccine for anthrax Because married women were not then permitted to work at University Tikvah and Max established a home laboratory where they worked together Their sons Jonathan and Michael were born in 1935 and 1936 From then on Tikvah Alper combined demands of motherhood Jonathan was born profoundly deaf marriage and career These included pre and post war spells in England where she worked with the pioneer radiobiologist Douglas Lea 7 Over ten years from 1937 Tikvah retrained and then also worked as a teacher of the deaf Her physics training and technical skills were evident in her published research on making speech articulation visible for use in speech training for deaf children 8 She became head of the Biophysics section of the South African National Physics Laboratory in 1948 Later career editDespite their growing scientific renown in 1951 Max Sterne and Tikvah Alper were forced to leave South Africa because of their outspoken opposition to apartheid Tikvah found an unpaid research post at the MRC Radiobiology Laboratories at the Hammersmith Hospital London directed by Hal Gray whom she had met on earlier visits Here work focussed on the mechanisms of the effects of radiation on cell biology The complexities of the effects of radiation on different cell types and their interaction with other physiological and chemical processes began to be mapped out at this time and continued through the 1950s and 60s She was Director of the Radiobiology Unit from 1962 until her retirement in 1974 Her classic text Cellular Radiobiology 9 was published in 1979 Tikvah Alper continued an active professional life in retirement culminating in a brilliant lecture to the Radiation Research Society in Dallas USA at the age of 83 4 10 She died in Sarisbury Hampshire England in 1995 11 and was survived by her husband Max sons Jonathan and Michael six grandchildren and three great grandchildren Alper s role in identifying the infectious agent in Scrapie editScrapie is a fatal infectious disease of the neural system of sheep one of a class of brain diseases that can affect cattle BSE and humans Kuru nCJD Scrapie had been thought to be caused by a slow virus one that could take years to show as a change in behaviour or movement By the mid 1960s it was established that cells could only replicate via DNA Radioactivity stops cell replication by killing DNA Alper found that radiation did not kill the infective agent in scrapie suggesting that a virus was unlikely to be the infective agent The infective agent had to be smaller and simpler than viral DNA Alper also found that the agent remained active under ultraviolet light DNA is inactive under UV light Instead the agent was killed by light at 237 nm a wavelength specific to polysaccharide inactivation Alper and colleagues 12 reported these properties of the scrapie agent a finding that was greeted with astonishment in many quarters for it appeared to contravene the central dogma that holds that replication and hence the growth of the disease and its infectious properties can only proceed via DNA However once these empirical findings were accepted several theories developed to accommodate the peculiar properties of the scrapie agent The most widely accepted theory today is the prion theory which posits a rogue protein as the infectious source However Alper could not accept that a protein mutation was the agent Firstly her UV radiation studies did not indicate a protein agent and secondly isolated prions did not induce scrapie Her own theories concerning the agent were developed in the last years of her life and suggested a more dynamic and complex story 13 See also editTimeline of women in scienceReferences edit Hunter A 2012 Radiation biology An important science South African Journal of Science 108 7 8 972 doi 10 4102 sajs v108i7 8 972 hdl 11427 29930 Highfield Roger The End of BSE The Telegram 11 February 2011 Vogt Annette B Tikvah Alpert 1909 1995 Jewish Women s Archive Encyclopedia Jewish Women s Archive Retrieved 17 December 2016 a b c Hornsey S Denekamp J 1997 Tikvah Alper An indomitable Spirit International Journal of Radiation Biology 71 6 631 42 doi 10 1080 095530097143635 PMID 9246177 Alper T 1932 Uber die d Strahlen und die Beziehung zwischen Reichweite und Geschwindigkeit fur langsame Elektronen Zeitschrift fur Physik 76 3 4 172 189 Bibcode 1932ZPhy 76 172A doi 10 1007 BF01341810 S2CID 122840914 Obituary Max Sterne The Independent 4 March 1997 Archived from the original on 7 May 2022 Retrieved 27 October 2017 Lecture by Douglas Lea Alper T Zimmerman H J 1939 A thyraton inflexion indicator for teaching the deaf Journal of Scientific Instruments 16 10 334 6 Bibcode 1939JScI 16 334S doi 10 1088 0950 7671 16 10 304 Alper Tikvah Cellular Radiobiology CUP Archive 1979 Alper T 1993 The Scrapie Enigma insights from radiation experiments Radiation Research 135 283 92 Fowler J April 1995 In memoriam Tikvah Alper 1909 1995 Radiation Research 142 1 110 2 PMID 7899554 Alper T et al 1967 Does the agent of scrapie replicate without Nucleic Acid Nature 214 5090 764 766 Bibcode 1967Natur 214 764A doi 10 1038 214764a0 PMID 4963878 S2CID 4195902 Alper T July 1992 The infectivity of spongiform encephalopathies does a modified membrane hypothesis account for lack of immune response FEMS Microbiology Letters 4 5 235 242 doi 10 1111 j 1574 6968 1992 tb05000 x PMID 1355344 Retrieved from https en wikipedia org w index php title Tikvah Alper amp oldid 1193592079, wikipedia, wiki, book, books, library,
