Redes de colaboración y objetos híbridos: mujeres citogenetistas en México, 1960s and 1970s / Collaborative networks and hybrid objects women cytogeneticists in Mexico, 1960-1980

Estudios recientes sobre la historia de la ciencia han enfatizado el enfoque transnacional que problematiza las narrativas eurocéntricas clásicas, las interpretaciones de difusión cultural y la oposición rígida de las categorías de «centro» y «periferia», para explicar la dinámica de los circuitos transnacionales y la circulación de conocimientos, personas, artefactos y prácticas científicas. El presente escrito intenta abonar en esta dirección al mostrar que el trabajo realizado por los genetistas mexicanos en los mil novecientos sesenta y setenta, en especial los trabajos de citogenética, no pueden caracterizarse como periféricos, pues al formar parte de redes de colaboración internacional, el conocimiento generado localmente en instituciones mexicanas y extranjeras logró circular y formar parte de la consolidación de la citogenética a escala global. En este artículo se abordarán las trayectorias de la bióloga y genetista mexicana María Cristina Cortinas, y en menor medida la de la médica y genetista mexicana de origen argentino Susana Kofman. Ellas compartieron agenda médica y de investigación además de tiempo y lugar, participaron en el diagnóstico temprano de enfermedades genéticas y revelaron la correlación entre las observaciones clínicas y el cariotipo. Este manuscrito se centrará, por un lado, en los cromosomas como objetos científicos híbridos que circularon entre la clínica y el laboratorio; por el otro, se abordarán los contextos locales, las culturas materialesy las prácticas específicas que permitieron a estas mujeres genetistas mexicanas ser parte de la producción y transmisión de conocimiento en los años mil novecientos sesenta y setenta, gracias a su pertenencia a redes científicas de colaboración nacionales e internacionales. (AU)

Recent studies on the history of science have emphasized the transnational approach that problematizes classic Eurocentric narratives, interpretations of cultural diffusion, and the rigid opposition of the categories of “center” and “periphery” to explain the dynamics of transnational circuits and the circulation of knowledge, people, artifacts, and scientific practices. This paper attempts to contribute to this direction by showing that the work carried out by Mexican geneticists in the 1960s and 1970s, especially the work on cytogenetics, cannot be characterized as peripheral because knowledge generated locally in Mexican and foreign institutions was able to circulate and become part of the consolidation of cytogenetics on a global scale, participating in international collaborative networks. This article addresses the trajectories of the Mexican biologist and geneticist María Cristina Cortinas, and to a lesser extent those of the Argentineborn Mexican physician and geneticist Susana Kofman. They shared a medical and research agenda and a time and place, participating in the early diagnosis of genetic diseases and revealing the correlation between clinical observations and the karyotype. This manuscript focuses on chromosomes as hybrid scientific objects that circulated between clinic and laboratory and on the local contexts, material cultures and specific practices that allowed these Mexican women geneticists to take part in the production and transmission of knowledge in the 1960s and 1970s, attributed to their participation in national and international scientific collaborative networks. (AU)

Breakage in breakage-fusion-bridge cycle: an 80-year-old mystery.

2021 marked the 80th anniversary of Barbara McClintock's pioneering article on the breakage-fusion-bridge (BFB) cycle. Of the three steps of the BFB cycle, breakage remains the least understood despite its major contribution to mutagenesis. We discuss recent findings shedding light on how chromatin bridges break in yeast and animal cells.

Molecularización, genetización y centros de referencia: el Instituto de Bioquímica Clínica de Barcelona (1969-1980) / Molecularization, geneticization and reference centers: the Institute of Clinical Biochemistry of Barcelona (1969-1980)

En conjunto, la molecularización y la genetización de la biomedicina del siglo XX construyeron un enorme listado de enfermedades, la mayoría raras, con unas necesidades asistenciales muy específicas, una gran dependencia del laboratorio e importantes dificulta-des para la creación de expertos. Estos fenómenos indujeron grandes cambios en las redes asistenciales y en los itinerarios diagnósticos. Uno de los más significativos fue la aparición de centros de referencia en los que concentrar los recursos humanos y materiales para enferme-dades tan poco prevalentes. A partir del estudio del Instituto de Bioquímica Clínica “Fundación Juan March” de Barcelona, este artículo aborda la aparición de estos nuevos espacios en la España del Tardofranquismo. Farmacéuticos, pediatras, políticos y gestores sanitarios, con sus diferentes intereses, aparecen como actores involucrados en la forja de un instituto que en pocos años se erigió como centro de referencia nacional para enfermedades de depósito lisosomal. El trabajo revela la importancia que tuvo la sensibilidad social sobre la discapacidad intelectual como motor (y excusa) de la iniciativa, el papel de las fundaciones filantrópicas y la influencia de la ciencia norteamericana en todo el proceso, en circulación a través de los viajes de los científicos españoles al extranjero (AU)

Human cytogenetics at Johns Hopkins Hospital, 1959-1962.

An account is given of the introduction of human cytogenetics to the Division of Medical Genetics at Johns Hopkins Hospital, and the first 3 years' work of the chromosome diagnostic laboratory that was established at the time. Research on human sex chromosome disorders, including novel discoveries in the Turner and Klinefelter syndromes, is described together with original observations on chromosome behavior at mitosis. It is written in celebration of the centenary of the birth of Victor McKusick, the acknowledged father of Medical Genetics, who established the Division and had the foresight to ensure that it included the investigation of human chromosomes.

Counting human chromosomes before 1960: preconceptions, perceptions and predilections.

In 1956 the biomedical world was surprised to hear a report that human cells each contained forty six chromosomes, rather than the forty eight count that had been documented since the 1920s. Application of available techniques to culture human cells in vitro, halt their division at metaphase, and disperse chromosomes in an optical plane permitted perception of visual images not seen before. Researchers continued to obtain the preconceived forty eight counts until reeducation with these novel epistemic 'chromosomes' convinced them that they could confidently report forty six chromosomes per cell. Within only a few years, and virtually without dissent, the social community of human cytogeneticists agreed upon a shared visual culture of human chromosome count and morphology. The initial forty six count proved not to be an anomaly. A new comparison of historical and ethnomethodological studies has suggested a better understanding of how applied technologies coupled with altered human perceptions established a new science. Human cytogenetics then collaborated with medical genetics to correlate changes in the new human karyotype with disorders of clinical significance.

What Does the History of Research on the Repair of DNA Double-Strand Breaks Tell Us?-A Comprehensive Review of Human Radiosensitivity.

Our understanding of the molecular and cellular response to ionizing radiation (IR) has progressed considerably. This is notably the case for the repair and signaling of DNA double-strand breaks (DSB) that, if unrepaired, can result in cell lethality, or if misrepaired, can cause cancer. However, through the different protocols, techniques, and cellular models used during the last four decades, the DSB repair kinetics and the relationship between cellular radiosensitivity and unrepaired DSB has varied drastically, moving from all-or-none phenomena to very complex mechanistic models. To date, personalized medicine has required a reliable evaluation of the IR-induced risks that have become a medical, scientific, and societal issue. However, the molecular bases of the individual response to IR are still unclear: there is a gap between the moderate radiosensitivity frequently observed in clinic but poorly investigated in the publications and the hyper-radiosensitivity of rare but well-characterized genetic diseases frequently cited in the mechanistic models. This paper makes a comprehensive review of semantic issues, correlations between cellular radiosensitivity and unrepaired DSB, shapes of DSB repair curves, and DSB repair biomarkers in order to propose a new vision of the individual response to IR that would be more coherent with clinical reality.

Karyotyping and population genetics in Cold War Mexico: Armendares's and Lisker's characterization of child and indigenous populations, 1960s-1980s.

This paper focuses on geneticists Salvador Armendares's and Rubén Lisker's studies from the 1960s to the 1980s, to explore how their work fits into the post-1945 human biological studies, and also how the populations they studied, child and indigenous, can be considered laboratories of knowledge production. This paper describes how populations were considered for different purposes: scientific inquiry, standardization of medical practices, and production or application of medicines. Through the narrative of the different trajectories and collaborations between Armendares and Lisker, this paper also attempts to show the contact of their scientific practices, which brought cytogenetics and population genetics together at the local and global levels from a transnational perspective.

Karyotyping and population genetics in Cold War Mexico: Armendares's and Lisker's characterization of child and indigenous populations, 1960s-1980s / Cariotipia e genética de populações no México da Guerra Fria: as caracterizações de Armendares e Lisker sobre as populações infantil e indígena, 1960-1980

Abstract This paper focuses on geneticists Salvador Armendares's and Rubén Lisker's studies from the 1960s to the 1980s, to explore how their work fits into the post-1945 human biological studies, and also how the populations they studied, child and indigenous, can be considered laboratories of knowledge production. This paper describes how populations were considered for different purposes: scientific inquiry, standardization of medical practices, and production or application of medicines. Through the narrative of the different trajectories and collaborations between Armendares and Lisker, this paper also attempts to show the contact of their scientific practices, which brought cytogenetics and population genetics together at the local and global levels from a transnational perspective.

Resumo Aborda o trabalho dos geneticistas Salvador Armendares e Rubén Lisker, entre 1960 e 1980, para analisar como se insere nos estudos biológicos humanos do pós-1945, e demonstra como as populações estudadas por eles, a infantil e a indígena, podem ser consideradas laboratórios de produção de conhecimento. O artigo revela como as populações foram consideradas para diversos propósitos: investigação científica, padronização das práticas médicas e produção ou aplicação de suas medicinas. Por meio da narrativa das diferentes trajetórias e colaborações entre Armendares e Lisker, também procura discutir o contato de suas práticas científicas, que colocaram a citogenética e a genética de populações lado a lado nos níveis local e global a partir de uma perspectiva transnacional.

Synthesis, convergence, and differences in the entangled histories of cytogenetics in medicine: A comparative study of Canada and Mexico.

Most historians of science and medicine agree that medical interest in genetics intensified after 1930, and interest in the relationship of radiation damage and genetics continued and expanded after World War II. Moreover, they maintain that the synthesis and convergence of human genetics and cytological techniques in European centers resulted in their dissemination to centers in the United States, resulting in a new field of expertise focused on medicine and clinical research, known as cytogenetics. In this article, we broaden the scope of the inquiry by showing how the early histories of cytogenetics in Canada and Mexico unfolded against strikingly different backgrounds in clinical research and the delivery of health care. We thus argue that the field of cytogenetics did not emerge in a straightforward manner and develop in the same way in all countries. The article provides a brief background to the history of human cytogenetics, and then outlines key developments related to the early adoption of cytogenetics in Canada and Mexico. Conclusions are then drawn using comparisons of the different ways in which local determinants affected adoption. We then propose directions for future study focused on the ways in which circuits of practices, collaborative research, and transfers of knowledge have shaped how cytogenetics has come to be organised in medicine around the world.

Circulating biomedical images: Bodies and chromosomes in the post-eugenic era.

This essay presents the early days of human cytogenetics, from the late 1950s until the mid 1970s, as a historical series of images. I propose a chronology moving from photographs of bodies to chromosome sets, to be joined by ultrasound images, which provided a return to bodies, by then focused on the unborn. Images carried ontological significance and, as I will argue, are principal characters in the history of human cytogenetics. Inspired by the historiography of heredity and genetics, studies on visual cultures, the conceptualization of circulation, and the sociology of pregnancy, I suggest that cytogenetics, through its focus on pregnancy, pregnant women, and their offspring, found strategic living materials that stabilized human chromosome studies as a biomedical, post-eugenics practice. The historicity of each path displays a wide circulation of objects, tools, and methods that condensed on images that shared in the centuries-old visual expertise that medicine and botany had manufactured.

A tale of two biographies: the myth and truth of Barbara McClintock.

Evelyn Fox Keller wrote first biography of the Nobel Prize winning geneticist Barbara McClintock in which Keller discussed how McClintock felt being rejected by her peers in the 1950s because she questioned the dominant idea of the particulate gene and instead proposed that the genetic material jumped positions on the chromosome which indicated that the gene did not control but was controlled by the cellular environment. Keller's story of McClintock's life is an account of a woman scientist's conception of science and how her unorthodox views isolated her from the main stream science. Keller's biography was read by many in a way that made McClintock a feminist icon by showing how women scientists "see" scientific objects differently and how their science is holistic and hence radically different from the reductionism of male-dominated science. The second biographer Nathaniel Comfort calls this story a myth. In his detailed intellectual biography, Comfort embarks on an energetic journey to separate fact from fiction to dismantle what he calls the McClintock myth. The difference between two biographers is not entirely about evidences or about separating fact from fiction but about their adoption of two contrasting paradigms of scientist's subjectivity: Keller foregrounds McClintock's affective self and Comfort her rational. In this commentary I have closely and comparatively read both biographies to revisit Keller's "myth" and Comfort's "truth" and to provide yet another interpretation of McClintock's life and work from the perspective of object relations theories in psychoanalysis. Instead of figuring out the extent to which the myth bears truth as Comfort does, I have asked questions: How and why this private myth was in the making throughout McClintock's life and work? How this private myth was related to the making of her science? By using developmental psychoanalytical approach, I show that what Comfort calls McClintock's private myth was not something that was partly fictional and hence incorrect or wrong but it emerged from a deeply and compellingly affective place in McClintock's life. This so called myth was integral to and fundamentally formative of who she was, a woman and a scientist, and that this myth formatively shaped McClintock's relationship with science's objects and science's subjects. This commentary aims to show the relevance and usefulness of psychoanalytical theories for understanding scientific subjectivities and provides a revision to the neo-Kantian idea of scientist subject-a unified and wilful, self-determined, self-regulated, active, autonomous, and rational subject wilfully driven by social and scientific ethos-generally popular among historians of science.

Cytogenetics at the University of Cape Town: A 45-year journey.

This article is a brief record of the cytogenetics laboratory from its birth in 1971, under the auspices of the University of Cape Town, throughout its development within the Department of Human Genetics, under the leadership of Professor Peter Beighton, to its present position at Groote Schuur Hospital, as a multidisciplinary unit run by the National Health Laboratory Service.