martes, 20 de enero de 2009

Henrietta Lacks, la mujer inmortal

Hace 58 años que Henrietta Lacks murió. Pero sigue viva . Henrietta Lacks , nacida Pleasant , fue una muchacha nacida en Roanoke, Virginia en 1920, hija de un padre reparador de frenos en los trenes y de una madre que tuvo 10 hijos . Luego de casarse con su amigo David Lacks, Henrietta tuvo cinco hijos : Deborah Lacks (nacida en 1948); David Lacks II; Lawrence Lacks; Zakariyya Lacks y otra hija nacida en 1950. Un día , luego de que Hentrietta participó en una manifestación de 10.000 personas en contra de la epidemia de polio, la muchacha fue al Hospital preocupada porque tenía una extraña descarga vaginal. Se trataba de un cáncer de útero. Henrietta murió a los 31 años por este mal , el 4 de Octubre de 1951 , y fue enterrada en el cementerio de Lackstown, en la ciudad de Clover, en Halifax, Virginia, de donde venian sus ancestros.
Pero en verdad , Henrietta no murió. El doctor que la atendía – George Otto Gey- hizo un cultivo de sus células , y las envió a distintos laboratorios que estudiaban procesos cancerosos. A las células de Henrietta se la llamaron HeLa, por ser un trocito de Henrietta Lacks. Lo emocionante del caso es que en 1954, las células de Henrietta fueron usadas por el doctor Jonas Salk para hacer una vacuna contra el polio, cosa que ella hubiera visto con gusto, ya que le preocupaba el tema al haber tenido hijos en la época de esta terrible epidemia, que en los 50 mataba a niños como a moscas . La demanda de las celulas HeLa creció enormente y las celulas de Henrietta viajaron a laboratorios de todo el mundo. Henrietta incluso viajó al espacio exterior - al menos, parte de su útero - en cápsulas espaciales donde se estudiaba el comportamiento de las celulas humanas con gravedad cero . Henrietta siguio ayudando post mortem a encontrar curas contra el sida , efectos de la radicacion y sustancias toxicas , proyectos geneticos, sensibilidad quimicos y muchos otras investigaciones .
Claro que ella nunca lo supo, porque el doctor conservó la muestra sin autorización expresa de ella, cosa que no contemplaba en la ley de entonces. Y me da un poco de sospecha de que hubo algo de abuso de derechos de parte de un doctor hijo de alemanes contra una muchacha humilde de raza negra . Para evitar problemas legales, se dijo que las células HeLa provenían de una tal Helen Lane o Helen Larson. Pero la verdad salió a flote, y – para compensar el atropello – le llovieron reconocimientos a la familia Lacks: de parte del intendente de Atlanta, Georgia, en 1996, por las contribucioes postumas que hicieron sus celulas, honores de parte del Instituto Smithsonian , y flores de parte de la National Foundation of Cancer Research . Los honores le llegaron tambien a la laboratorista Mary Kubicek, por haber decsubierto que las celulas de Henrietta vivían fuera del cuerpo, y al doctor George Otto Gey y a su esposa Margaret Gey, que no pudieron hacer nada por salvar la vida de Henrietta , aunque lograron – luego de 20 años de investigación- mantener con vida a las células de cuello de su útero . Henrietta , hoy

Ahora bien, ¿estas celulas vivirán para siempre?
Esto depende en verdad del límite Hayflick, que es el número de veces que una célula puede dividirse antes que el telómero - una parte de la celula que participa en la división celular - llegue a su largo límite, acortñándose en cada división . Leonard Hayflick demostró en 1965, que una célula humana se divide unas 52 veces en un 20% de oxígeno ( el aire normal) y 70 veces en 3% de oxigeno ( el del cuerpo humano) Alli comienza la fase de senectud: cada mitosis acorta el apéndice del ADN llamado telómero ,acortando la materia para una nueva copia de otra célula futura. Es como si hicieras copias en una impresora , en la cual el papel se corriera un centimetro cada vez, hasta que ya el texto no aparece más, por dar un ejemplo burdo. El telómero se acorta como se acortaría el papel. O mejor,como se acaba como se termina la cinta de regalo cada vez que tienes que hacer un moño . Haces un monton de paquetes con moños petçrfectos, hasta que él ultimo moño es ridículamente feo por falta de cinta, y uno decide enviar el regalo sin moño . Y es la muerte del moño...o de la célula.
Algunos pocos animales tienen telómeros que se autorçreparan a medida que el animal crece , dándole una vida al animal mucho mas larga de la habitual. Es el caso del Petrel de Leach, del norte de Canadá, que vive hasta 40 años, una edad asombrosa para una pajarito de 15 centimetros de largo .
Un cientifico japonés descubrió además que las celulas cancerosas tienen gran cantidad de una proteina llamada leupina. La células con leupina se rehusan a morir. Las celulas de He La están llenas de leupina y se siguen reproduciendo sin cambios aparentes, y mostrando celulas idénticas a las antecesoras lo que facilita cualquer estudio. Lo complica por otro lado : sus ganas de vivir son tales, que muchas veces arruinaron estudios enteros contaminando otras celulas vecinas.
¿ Cual es el secreto de las celulas He La y de todas las celulas cancerosas para vivir eternamente, sin envejecer? El secretos es que todas las celulas poseen en su DNA el gen de una enzima llamada telomerasa, que sirve para restaurar DAN a la punta del telomero cada vez que se produce una division celular, para mantener su largo original. En casi todas las celulas este gen se apaga, permitiendo que mueran las células menos que perfectas, para que sean reemplazadas por otras nuevas. Esto lo hace el organismo para prevenir, justamente, la proliferación exagerada de celulas y tumores. Solo cuando el sistema no puede "apagar" la funicón de la telomarasa, las celulas siguen reproduciendose y forman tumores, como una canilla abierta , de manera enloquecida . Las células tumorales son inmortales porque producen telomerasa. Cuanta más telomerasa, mayor es la malignidad del tumor. Las únicas celulas inmortales en el humanos son las cancerosas y las stem cells, nacidas de embriones, que pueden convertirse en cualquiera de las 210 celulas del cuerpo humano .
Otra cosa que se ha estudiado es que los centenarios tienen bajos niveles de trigliceridos MTP .El ajo – habitual en sus dietas – suele suprimirlo.
Tantos avances se están haciendo por estirar la vida humana al maximo, que algunos cinetificos dicen que quien este vivió de aqui a 25 años, vivirá para siempre.
Pero asì y todo, algunos teóricos dicen que esta idea de vivir para siempre y aferrarse a la vida con garras y uñas, es la que provoca ciertos tipos de cáncer. Es el famoso problema moderno del “dejar soltar”, dejar que se cierre un ciclo y comience otro, y aceptar con agrado los cambios y con filosofúia las pérdidas. Pero el ser humano siempre tuvo un tema con las pérdidas: no se aguanta ni perder una lapicera, ¿ cómo va a soportar perder la existencia?.
Si uno le teme tanto a la muerte que ni puede pensar en ella, - opinan ciertos terapeutas - lo más probable es que envie a su cuerpo ciertos mensajes que el organismo interpreta como que es pésimo morir, por lo cual en ciertos órganos muy obedientes se vuelven inmortales, las celulas extras ocupan el sitio de las sanas o invaden todo el cuerpo en un ataque de inmortalidad general llamado “ metástasis”. El cancer es la enfermedad del quererlo todo ya , dicen muchos. De este modo, los telómeros siguen creciendo y autoreparándose, y todo se resiste a perecer y no muere ni siendo atacado con terribles tratamientos de quemadura por ácidos y rayos . Hasta que por fin , el organismo entero sucumbe cuando la invasion de células inmortales no permite que nada funcione normalmente. Si vieras lo apretado que está todo dentro del cuerpo humano- para que todo quepa bien sin que midamos tres metros de ancho- , sabrías que el problema principal del cáncer es que adentro de nuestra piel no entra más nada. Es como intentar poner un zapato en una valija que ya cerraste a la fuerza: estallará la cremallera y adiós valija. .
No quisiera estar viva cuando algun médico del 2060 se equivoque, aplique telomerasa donde no debe y genere imprevistos cánceres masivos en todos aquellos que quieran probar la fórmula de la inmortalidad.
Dejemos la inmortalidad , entonces , para el cuello del útero de Henrietta, que la pasa bárbaro viajando por todo el mundo en placas de Petri . Dicen que Henrietta Lack ya creció tanto que está pesando varias toneladas. Aunque no creo que a ella le preocupe el tema del aumento de peso .
¿ Qué hay que hacer para vivir para siempre? Comer mucho ajo, donar tus celulas a un laboratorio ambicioso, y tratar de reencarnarte en un longevo petrel marino canadiense.
Aunque con lo del ajo, ya sabes: tendrás una vida larga …y solitaria.
Foto: El Dr Gey , que mandó a Henrietta a viajar por el mundo y el espacio.



Noticia de Mayo 2011 :
"La vida Inmortal de Henrietta Lacks" es hoy el tercer libro mas vendidos de Estados Unidos. Yo sabia que este tema es atrapante!
Reseña del New York Times :


From “The Immortal Life of Henrietta Lacks”
Henrietta and David Lacks, circa 1945.

THE IMMORTAL LIFE OF HENRIETTA LACKS

By Rebecca Skloot

Illustrated. 369 pp. Crown Publishers. $26


From the very beginning there was something uncanny about the cancer cells on Henrietta Lacks’s cervix. Even before killing Lacks herself in 1951, they took on a life of their own. Removed during a biopsy and cultured without her permission, the HeLa cells (named from the first two letters of her first and last names) reproduced boisterously in a lab at Johns Hopkins — the first human cells ever to do so. HeLa became an instant biological celebrity, traveling to research labs all over the world. Meanwhile Lacks, a vivacious 31-year-old African-American who had once been a tobacco farmer, tended her five children and endured scarring radiation treatments in the hospital’s “colored” ward.


Dwight Garner’s Review of ‘The Immortal Life of Henrietta Lacks’ (February 3, 2010)After Henrietta Lacks’s death, HeLa went viral, so to speak, becoming the godmother of virology and then biotech, benefiting practically anyone who’s ever taken a pill stronger than aspirin. Scientists have grown some 50 million metric tons of her cells, and you can get some for yourself simply by calling an 800 number. HeLa has helped build thousands of careers, not to mention more than 60,000 scientific studies, with nearly 10 more being published every day, revealing the secrets of everything from aging and cancer to mosquito mating and the cellular effects of working in sewers.

HeLa is so outrageously robust that if one cell lands in a petri dish, it proceeds to take over. And so, like any good celebrity, HeLa had a scandal: In 1966 it became clear that HeLa had contaminated hundreds of cell lines, destroying research as far away as Russia. By 1973, when Lacks’s children were shocked to learn that their mother’s cells were still alive, HeLa had already been to outer space.

During the eight months that Lacks herself was dying of cancer, the HeLa cells so thoroughly eclipsed her that a lab assistant at her autopsy glanced at her painted red toes and thought: “Oh jeez, she’s a real person. . . . I started imagining her sitting in her bathroom painting those toenails, and it hit me for the first time that those cells we’d been working with all this time and sending all over the world, they came from a live woman. I’d never thought of it that way.”

In “The Immortal Life of Henrietta Lacks,” Rebecca Skloot introduces us to the “real live woman,” the children who survived her, and the interplay of race, poverty, science and one of the most important medical discoveries of the last 100 years. Skloot narrates the science lucidly, tracks the racial politics of medicine thoughtfully and tells the Lacks family’s often painful history with grace. She also confronts the spookiness of the cells themselves, intrepidly crossing into the spiritual plane on which the family has come to understand their mother’s continued presence in the world. Science writing is often just about “the facts.” ­Skloot’s book, her first, is far deeper, braver and more wonderful.

Skloot didn’t know what she was getting into when she began researching the book as a graduate student in 1999. The first time she called Lacks’s widower, then living in Baltimore, the person who answered the phone simply heard her voice and yelled, “Get Pop, lady’s on the phone about his wife cells.” Over the years it took Skloot to gain the family’s trust, she came to understand that the only time white people ever called the house was when they wanted something to do with the HeLa cells. Some of the family feel they’ve been ripped off, cheated by either Johns Hopkins (though the hospital never sold the cells) or the entire medical establishment, which has made enormous profits from the cells.

Skloot traces the family’s emotional ordeal, the changing ethics and law around tissue collections, and the inadvertently careless journalists and researchers who violated the family’s privacy by publishing everything from Henrietta’s medical records to the family’s genetic information. She tacks between the perspective of the scientists and the family evenly and fairly, arriving at a paradox described by Henrietta’s daughter Deborah. “Truth be told, I can’t get mad at science, because it help people live, and I’d be a mess without it. I’m a walking drugstore! . . . But I won’t lie, I would like some health insurance so I don’t got to pay all that money every month for drugs my mother cells probably helped make.”

Deborah, a generous spirit, becomes the book’s driving force, as Skloot joins her in her “lifelong struggle to make peace with the existence of those cells, and the science that made them possible.” To find the mother she never got to know, she read hundreds of articles about HeLa research, which led her to believe that her mother was “eternally suffering” from all the experiments performed on her cells. In unsentimental prose, Skloot describes traveling with her to Clover, Va., where Henrietta grew up in her grandfather’s cabin, former slave quarters in a town where the black Lackses and the white Lackses don’t mix. Suffering from hives and extreme anxiety, Deborah seeks out a relative who channels the voice of God. He tells Deborah to let ­Skloot carry the “burden” of the cells from now on, explaining that the cells have become heavenly bodies, immortal angels.

But “The Immortal Life of Henrietta Lacks” is much more than a portrait of the Lacks family. It is also a critique of science that insists on ignoring the messy human provenance of its materials. “Scientists don’t like to think of HeLa cells as being little bits of Henrietta because it’s much easier to do science when you dissociate your materials from the people they come from,” a researcher named Robert Stevenson tells Skloot in one of the many ethical discussions seeded throughout the book.The ethical issues implicated in the HeLa story are many and tangled. Since 1951, science has progressed much faster than our ability to figure out what is right and wrong about tissue culture. In the 1980s a doctor who had removed the cancer-ridden spleen of a man named John Moore patented some of the cells to create a cell line then valued at more than $3 billion, without Moore’s knowledge. Moore sued, and on appeal the court ruled that patients had the right to control their tissues, but soon that was struck down by the California Supreme Court, which said that tissue removed from the body had been abandoned as medical waste. The cell line created by the doctor had been “transformed” via his “inventive effort,” and to say otherwise would “destroy the economic incentive to conduct important medical research.” The court said that doctors should disclose their financial interests and called on legislators to increase patient protections and regulation, but this has hardly hindered the growth of the field. In 1999 the RAND Corporation estimated that American labs alone held more than 307 million tissue samples from some 178 million people. Not only is the question of payment for profitable tissues unresolved, Skloot notes, but it’s still not necessary to obtain consent to store cells and tissue taken in diagnostic procedures and then use the samples for research.

Dwight Garner’s Review of ‘The Immortal Life of Henrietta Lacks’ (February 3, 2010)The scene in this book that made my hair stand on end occurred when the Lackses followed Skloot into the world of science, just as she had followed them into the world of faith. In 2001, an Austrian researcher at Johns Hopkins named Christoph Lengauer invited the family to his lab. When Deborah and her brother visited, he led them to the basement, where they “saw” their mother for the first time, warming frozen test tubes of HeLa in their hands and watching as a cell divided into two under a microscope while Lengauer explained his work. Deborah pressed a cold vial to her lips. “You’re famous,” she whispered. “Just nobody knows it.”


ooks of The TimesA Woman’s Undying Gift to Science Twitter
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LinkedinDiggMySpacePermalink By DWIGHT GARNER
Published: February 2, 2010
The best book blurb I’m aware of came from Roy Blount Jr., who said about Pete Dexter’s 1988 novel, “Paris Trout”: “I put it down once to wipe off the sweat.” I’m not sure I know what that means. Was the sweat on Mr. Blount’s forehead? On the dust jacket? On the inside of his fogged-up reading glasses? But I like it.

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From “The Immortal Life of Henrietta Lacks”
Henrietta and David Lacks, circa 1945.

THE IMMORTAL LIFE OF HENRIETTA LACKS

By Rebecca Skloot

Illustrated. 369 pages. Crown Publishers. $26.

Related
Excerpt: ‘The Immortal Life of Henrietta Lacks’ (March 3, 2010)
Second Opinion: A Lasting Gift to Medicine That Wasn’t Really a Gift (February 2, 2010)
The Sunday Book Review on ‘The Immortal Life of Henrietta Lacks’ (February 7, 2010)

Manda Townsend
Rebecca Skloot
I put down Rebecca Skloot’s first book, “The Immortal Life of Henrietta Lacks,” more than once. Ten times, probably. Once to poke the fire. Once to silence a pinging BlackBerry. And eight times to chase my wife and assorted visitors around the house, to tell them I was holding one of the most graceful and moving nonfiction books I’ve read in a very long time.

A thorny and provocative book about cancer, racism, scientific ethics and crippling poverty, “The Immortal Life of Henrietta Lacks” also floods over you like a narrative dam break, as if someone had managed to distill and purify the more addictive qualities of “Erin Brockovich,” “Midnight in the Garden of Good and Evil” and “The Andromeda Strain.” More than 10 years in the making, it feels like the book Ms. Skloot was born to write. It signals the arrival of a raw but quite real talent.

The woman who provides this book its title, Henrietta Lacks, was a poor and largely illiterate Virginia tobacco farmer, the great-great-granddaughter of slaves. Born in 1920, she died from an aggressive cervical cancer at 31, leaving behind five children. No obituaries of Mrs. Lacks appeared in newspapers. She was buried in an unmarked grave.

To scientists, however, Henrietta Lacks almost immediately became known simply as HeLa (pronounced hee-lah), from the first two letters of her first and last names. Cells from Mrs. Lacks’s cancerous cervix, taken without her knowledge, were the first to grow in culture, becoming “immortal” and changing the face of modern medicine. There are, Ms. Skloot writes, “trillions more of her cells growing in laboratories now than there ever were in her body.” Laid end to end, the world’s HeLa cells would today wrap around the earth three times.

Because HeLa cells reproduced with what the author calls a “mythological intensity,” they could be used in test after test. “They helped with some of the most important advances in medicine: the polio vaccine, chemotherapy, cloning, gene mapping, in vitro fertilization,” Ms. Skloot writes. HeLa cells were used to learn how nuclear bombs affect humans, and to study herpes, leukemia, Parkinson’s disease and AIDS. They were sent up in the first space missions, to see what becomes of human cells in zero gravity.

Bought and sold and shipped around the world for decades, HeLa cells are famous to science students everywhere. But little has been known, until now, about the unwitting donor of these cells. Mrs. Lacks’s own family did not know that her cells had become famous (and that people had grown wealthy from marketing them) until more than two decades after her death, after scientists had begun to take blood from her surviving family members, without their informed consent, in order to better study HeLa.

Ms. Skloot, a young science journalist and an indefatigable researcher, writes about Henrietta Lacks and her impact on modern medicine from almost every conceivable angle and manages to make all of them fascinating. She reports, for example, on the history and science of cellular research, about its pioneers and its calumnies. But “The Immortal Life of Henrietta Lacks” resonates most as a complex and vital human document and a searching moral inquiry into greed and blinkered lives.

Ms. Skloot tells the story of Mrs. Lacks’s life, from those tobacco fields in small-town Clover, Va., to the “colored” ward of Johns Hopkins Hospital in Baltimore in the 1950s, where she was treated for her cancer, and where her cells were harvested. She follows the members of Mrs. Lacks’s family to East Baltimore, where many of them live today, still struggling with her complicated legacy. As one of Mrs. Lacks’s sons says: “She’s the most important person in the world, and her family living in poverty. If our mother so important to science, why can’t we get health insurance?”“The Immortal Life of Henrietta Lacks” is packed with memorable characters, from quirky if brilliant early researchers to Nobel Prize-winning Nazi sympathizers to long-haired Rolling Stone reporters in the 1970s to a con artist known as Sir Lord Keenan Kester Cofield. (Just when you think things can’t get weirder, Judge Joseph Wapner — the “People’s Court” television judge — makes a cameo.)

Skip to next paragraph THE IMMORTAL LIFE OF HENRIETTA LACKS

By Rebecca Skloot

Illustrated. 369 pages. Crown Publishers. $26.

Related
Excerpt: ‘The Immortal Life of Henrietta Lacks’ (March 3, 2010)
Second Opinion: A Lasting Gift to Medicine That Wasn’t Really a Gift (February 2, 2010)
The Sunday Book Review on ‘The Immortal Life of Henrietta Lacks’ (February 7, 2010)Ms. Skloot is a memorable character herself. She never intrudes on the narrative, but she takes us along with her on her reporting, as she moves around the country in her battered, muffler-free black Honda. Her most complicated job is to get Mrs. Lacks’s family, who are tired of white people trying to pry information from them, to speak with her. She does eventually win them over. And Mrs. Lacks’s daughter Deborah is dead-on when she says to Ms. Skloot: “Get ready, girl. You got no idea what you gettin’ yourself into.”

Ms. Skloot writes with particular sensitivity and grace about the history of race and medicine in America. Black oral history, she points out, is full of stories about “night doctors,” men who could pluck black patients off the streets to experiment on their bodies. There was some truth behind those tales.

The author traces events like the infamous Tuskegee syphilis study, in which poor and uneducated black men with syphilis were recruited and then allowed to die terrible and entirely preventable deaths, while doctors lied to them and kept life-saving penicillin from them. Ms. Skloot makes it abundantly clear why, when Henrietta Lacks’s family learned that her cells were still living, the images that ran through their minds were straight out of science-fiction horror movies.

Mrs. Lacks had another daughter, Elsie, who was deaf and mute and possibly retarded. Elsie was shipped off at a young age to Crownsville State Hospital in Maryland, formerly known as the Hospital for the Negro Insane, and died there at 15. Perhaps the most devastating moment in this book comes when Ms. Skloot, along with Deborah, finds a grim photograph of Elsie in the hospital’s records and uncovers some of the horrors of what life there must have been like.

“The Immortal Life of Henrietta Lacks” is also, from first page to last, a meditation on medical ethics — on the notion of informed consent, and on the issue of who owns human cells. When they’re in your body, it’s obvious — they’re yours. But once they’ve been removed? All bets are clearly off.

This is the place in a review where critics tend to wedge in the sentence that says, in so many words, “This isn’t a perfect book.” And “The Immortal Life of Henrietta Lacks” surely isn’t. But there isn’t much about it I’d want to change. It has brains and pacing and nerve and heart, and it is uncommonly endearing. You might put it down only to wipe off the sweat.

2 comentarios:

asistencia dijo...

me encanto tu articulo

KEPLER: Biología y Quimica dijo...

Super buen artículo, pero tiene un error tremendo. Los telómeros se acortan por la replicación, lo cual ocurrirá antes de las MITOSIS. Si esas células hicieran meiosis, no se volverían a dividir.

Saludos y muy buen artículo.

Cristobal
Bioquimico.