12 February 2009

Blood transfusion

The invention: A technique that greatly enhanced surgery patients’ chances of survival by replenishing the blood they lose in surgery with a fresh supply. The people behind the invention: Charles Drew (1904-1950), American pioneer in blood transfusion techniques George Washington Crile (1864-1943), an American surgeon, author, and brigadier general in the U.S. Army Medical Officers’ Reserve Corps Alexis Carrel (1873-1944), a French surgeon Samuel Jason Mixter (1855-1923), an American surgeon Nourishing Blood Transfusions It is impossible to say when and where the idea of blood transfusion first originated, although descriptions of this procedure are found in ancient Egyptian and Greek writings. The earliest documented case of a blood transfusion is that of Pope Innocent VII. In April, 1492, the pope, who was gravely ill, was transfused with the blood of three young boys. As a result, all three boys died without bringing any relief to the pope. In the centuries that followed, there were occasional descriptions of blood transfusions, but it was not until the middle of the seventeenth century that the technique gained popularity following the English physician and anatomistWilliam Harvey’s discovery of the circulation of the blood in 1628. In the medical thought of those times, blood transfusion was considered to have a nourishing effect on the recipient. In many of those experiments, the human recipient received animal blood, usually from a lamb or a calf. Blood transfusion was tried as a cure for many different diseases, mainly those that caused hemorrhages, as well as for other medical problems and even for marital problems. Blood transfusions were a dangerous procedure, causing many deaths of both donor and recipient as a result of excessive blood loss, infection, passage of blood clots into the circulatory systems of the recipients, passage of air into the blood vessels (air embolism), and transfusion reaction as a result of incompatible blood types. In the mid-nineteenth century, blood transfusions from animals to humans stopped after it was discovered that the serum of one species agglutinates and dissolves the blood cells of other species. A sharp drop in the use of blood transfusion came with the introduction of physiologic salt solution in 1875. Infusion of salt solution was simple and was safer than blood transfusion.Direct-Connection Blood Transfusions In 1898, when GeorgeWashington Crile began his work on blood transfusions, the major obstacle he faced was solving the problem of blood clotting during transfusions. He realized that salt solutions were not helpful in severe cases of blood loss, when there is a need to restore the patient to consciousness, steady the heart action, and raise the blood pressure. At that time, he was experimenting with indirect blood transfusions by drawing the blood of the donor into a vessel, then transferring it into the recipient’s vein by tube, funnel, and cannula, the same technique used in the infusion of saline solution. The solution to the problem of blood clotting came in 1902 when Alexis Carrel developed the technique of surgically joining blood vessels without exposing the blood to air or germs, either of which can lead to clotting. Crile learned this technique from Carrel and used it to join the peripheral artery in the donor to a peripheral vein of the recipient. Since the transfused blood remained sealed in the inner lining of the vessels, blood clotting did not occur. The first human blood transfusion of this type was performed by Crile in December, 1905. The patient, a thirty-five-year-old woman, was transfused by her husband but died a few hours after the procedure. The second, but first successful, transfusion was performed on August 8, 1906. The patient, a twenty-three-year-old male, suffered from severe hemorrhaging following surgery to remove kidney stones. After all attempts to stop the bleeding were exhausted with no results, and the patient was dangerously weak, transfusion was considered as a last resort. One of the patient’s brothers was the dofew days later, another transfusion was done. This time, too, he showed remarkable improvement, which continued until his complete recovery. For his first transfusions, Crile used the Carrel suture method, which required using very fine needles and thread. It was a very delicate and time-consuming procedure. At the suggestion of Samuel Jason Mixter, Crile developed a new method using a short tubal device with an attached handle to connect the blood vessels. By this method, 3 or 4 centimeters of the vessels to be connected were surgically exposed, clamped, and cut, just as under the previous method. Yet, instead of suturing of the blood vessels, the recipient’s vein was passed through the tube and then cuffed back over the tube and tied to it. Then the donor’s artery was slipped over the cuff. The clamps were opened, and blood was allowed to flow from the donor to the recipient. In order to accommodate different-sized blood vessels, tubes of four different sizes were made, ranging in diameter from 1.5 to 3 millimeters.Impact, Crile’s method was the preferred method of blood transfusion for a number of years. Following the publication of his book on transfusion, a number of modifications to the original method were published in medical journals. In 1913, Edward Lindeman developed a method of transfusing blood simply by inserting a needle through the patient’s skin and into a surface vein, making it for the first time a nonsurgical method. This method allowed one to measure the exact quantity of blood transfused. It also allowed the donor to serve in multiple transfusions. This development opened the field of transfusions to all physicians. Lindeman’s needle and syringe method also eliminated another major drawback of direct blood transfusion: the need to have both donor and recipient right next to each other.

Birth control pill

The invention: An orally administered drug that inhibits ovulation in women, thereby greatly reducing the chance of pregnancy. The people behind the invention: Gregory Pincus (1903-1967), an American biologist Min-Chueh Chang (1908-1991), a Chinese-born reproductive biologist John Rock (1890-1984), an American gynecologist Celso-Ramon Garcia (1921- ), a physician Edris Rice-Wray (1904- ), a physician Katherine Dexter McCormick (1875-1967), an American millionaire Margaret Sanger (1879-1966), an American activist An Ardent Crusader Margaret Sanger was an ardent crusader for birth control and family planning. Having decided that a foolproof contraceptive was necessary, Sanger met with her friend, the wealthy socialite Katherine Dexter McCormick. A1904 graduate in biology from the Massachusetts Institute of Technology, McCormick had the knowledge and the vision to invest in biological research. Sanger arranged a meeting between McCormick and Gregory Pincus, head of the Worcester Institutes of Experimental Biology. After listening to Sanger’s pleas for an effective contraceptive and McCormick’s offer of financial backing, Pincus agreed to focus his energies on finding a pill that would prevent pregnancy. Pincus organized a team to conduct research on both laboratory animals and humans. The laboratory studies were conducted under the direction of Min-Chueh Chang, a Chinese-born scientist who had been studying sperm biology, artificial insemination, and in vitro fertilization. The goal of his research was to see whether pregnancy might be prevented by manipulation of the hormones usually found in a woman.It was already known that there was one time when a woman could not become pregnant—when she was already pregnant. In 1921, Ludwig Haberlandt, an Austrian physiologist, had transplanted the ovaries from a pregnant rabbit into a nonpregnant one. The latter failed to produce ripe eggs, showing that some substance from the ovaries of a pregnant female prevents ovulation. This substance was later identified as the hormone progesterone by George W. Corner, Jr., and Willard M. Allen in 1928. If progesterone could inhibit ovulation during pregnancy, maybe progesterone treatment could prevent ovulation in nonpregnant females as well. In 1937, this was shown to be the case by scientists from the University of Pennsylvania, who prevented ovulation in rabbits with injections of progesterone. It was not until 1951, however, when Carl Djerassi and other chemists devised inexpensive ways of producing progesterone in the laboratory, that serious consideration was given to the medical use of progesterone. The synthetic version of progesterone was called “progestin.” Testing the Pill In the laboratory, Chang tried more than two hundred different progesterone and progestin compounds, searching for one that would inhibit ovulation in rabbits and rats. Finally, two compounds were chosen: progestins derived from the root of a wild Mexican yam. Pincus arranged for clinical tests to be carried out by Celso- Ramon Garcia, a physician, and John Rock, a gynecologist. Rock had already been conducting experiments with progesterone as a treatment for infertility. The treatment was effective in some women but required that large doses of expensive progesterone be injected daily. Rock was hopeful that the synthetic progestin that Chang had found effective in animals would be helpful in infertile women as well. With Garcia and Pincus, Rock treated another group of fifty infertile women with the synthetic progestin. After treatment ended, seven of these previously infertile women became pregnant within half a year. Garcia, Pincus, and Rock also took several physiological measurements of the women while they were taking the progestin and were able to conclude that ovulation did not occur while the women were taking the progestin pill.Having shown that the hormone could effectively prevent ovulation in both animals and humans, the investigators turned their attention back to birth control. They were faced with several problems: whether side effects might occur in women using progestins for a long time, and whether women would remember to take the pill day after day, for months or even years. To solve these problems, the birth control pill was tested on a large scale. Because of legal problems in the United States, Pincus decided to conduct the test in Puerto Rico. The test started in April of 1956. Edris Rice-Wray, a physician, was responsible for the day-to-day management of the project. As director of the Puerto Rico Family Planning Association, she had seen firsthand the need for a cheap, reliable contraceptive. The women she recruited for the study were married women from a low-income population living in a housing development in Río Piedras, a suburb of San Juan. Word spread quickly, and soon women were volunteering to take the pill that would prevent pregnancy. In the first study, 221 women took a pill containing 10 milligrams of progestin and 0.15 milligrams of estrogen. (The estrogen was added to help control breakthrough bleeding.) Results of the test were reported in 1957. Overall, the pill proved highly effective in preventing conception. None of the women who took the pill according to directions became pregnant, and most women who wanted to get pregnant after stopping the pill had no difficulty. Nevertheless, 17 percent of the women had some unpleasant reactions, such as nausea or dizziness. The scientists believed that these mild side effects, as well as one death from congestive heart failure, were unrelated to the use of the pill. Even before the final results were announced, additional field tests were begun. In 1960, the U.S. Food and Drug Administration (FDA) approved the use of the pill developed by Pincus and his collaborators as an oral contraceptive.Consequences Within two years of approval by the FDA, more than a million women in the United States were using the birth control pill. New contraceptives were developed in the 1960’s and 1970’s, but the birth control pill remains the most widely used method of preventing pregnancy. More than 60 million women use the pill worldwide. The greatest impact of the pill has been in the social and political world. Before Sanger began the push for the pill, birth control was regarded often as socially immoral and often illegal as well. Women in those post-World War II years were expected to have a lifelong career as a mother to their many children. With the advent of the pill, a radical change occurred in society’s attitude toward women’s work.Women had increased freedom to work and enter careers previously closed to them because of fears that they might get pregnant. Women could control more precisely when they would get pregnant and how many children they would have. The women’s movement of the 1960’s—with its change to more liberal social and sexual values—gained much of its strength from the success of the birth control pill.

10 February 2009

BINAC computer

The invention: The world’s first electronic general-purpose digital computer. The people behind the invention: John Presper Eckert (1919-1995), an American electrical engineer John W. Mauchly (1907-1980), an American physicist John von Neumann (1903-1957), a Hungarian American mathematician Alan Mathison Turing (1912-1954), an English mathematician Computer Evolution In the 1820’s, there was a need for error-free mathematical and astronomical tables for use in navigation, unreliable versions of which were being produced by human “computers.” The problem moved English mathematician and inventor Charles Babbage to design and partially construct some of the earliest prototypes of modern computers, with substantial but inadequate funding from the British government. In the 1880’s, the search by the U.S. Bureau of the Census for a more efficient method of compiling the 1890 census led American inventor Herman Hollerith to devise a punched-card calculator, a machine that reduced by several years the time required to process the data. The emergence of modern electronic computers began during World War II (1939-1945), when there was an urgent need in the American military for reliable and quickly produced mathematical tables that could be used to aim various types of artillery. The calculation of very complex tables had progressed somewhat since Babbage’s day, and the human computers were being assisted by mechanical calculators. Still, the growing demand for increased accuracy and efficiency was pushing the limits of these machines. Finally, in 1946, following three years of intense work at the University of Pennsylvania’s Moore School of Engineering, John Presper Eckert and John W. Mauchly presented their solution to the problems in the form of the Electronic Numerical Integrator and Calculator (ENIAC) the world’s first electronic general-purpose digital computer. The ENIAC, built under a contract with the Army’s Ballistic Research Laboratory, became a great success for Eckert and Mauchly, but even before it was completed, they were setting their sights on loftier targets. The primary drawback of the ENIAC was the great difficulty involved in programming it. Whenever the operators needed to instruct the machine to shift from one type of calculation to another, they had to reset a vast array of dials and switches, unplug and replug numerous cables, and make various other adjustments to the multiple pieces of hardware involved. Such a mode of operation was deemed acceptable for the ENIAC because, in computing firing tables, it would need reprogramming only occasionally. Yet if instructions could be stored in a machine’s memory, along with the data, such a machine would be able to handle a wide range of calculations with ease and efficiency. The Turing Concept The idea of a stored-program computer had first appeared in a paper published by English mathematician Alan Mathison Turing in 1937. In this paper, Turing described a hypothetical machine of quite simple design that could be used to solve a wide range of logical and mathematical problems. One significant aspect of this imaginary Turing machine was that the tape that would run through it would contain both information to be processed and instructions on how to process it. The tape would thus be a type of memory device, storing both the data and the program as sets of symbols that the machine could “read” and understand. Turing never attempted to construct this machine, and it was not until 1946 that he developed a design for an electronic stored-program computer, a prototype of which was built in 1950. In the meantime, John von Neumann, a Hungarian American mathematician acquainted with Turing’s ideas, joined Eckert and Mauchly in 1944 and contributed to the design of ENIAC’s successor, the Electronic Discrete Variable Automatic Computer (EDVAC), another project financed by the Army. The EDVAC was the first computer designed to incorporate the concept of the stored program.In March of 1946, Eckert and Mauchly, frustrated by a controversy over patent rights for the ENIAC, resigned from the Moore School. Several months later, they formed the Philadelphiabased Electronic Control Company on the strength of a contract from the National Bureau of Standards and the Census Bureau to build a much grander computer, the Universal Automatic Computer (UNIVAC). They thus abandoned the EDVAC project, which was finally completed by the Moore School in 1952, but they incorporated the main features of the EDVAC into the design of the UNIVAC. Building the UNIVAC, however, proved to be much more involved and expensive than anticipated, and the funds provided by the original contract were inadequate. Eckert and Mauchly, therefore, took on several other smaller projects in an effort to raise funds. On October 9, 1947, they signed a contract with the Northrop Corporation of Hawthorne, California, to produce a relatively small computer to be used in the guidance system of a top-secret missile called the Snark, which Northrop was building for the Air Force. This computer, the Binary Automatic Computer (BINAC), turned out to be Eckert and Mauchly’s first commercial sale and the first stored-program computer completed in the United States. The BINAC was designed to be at least a preliminary version of a compact, airborne computer. It had two main processing units. These contained a total of fourteen hundred vacuum tubes, a drastic reduction from the eighteen thousand used in the ENIAC. There were also two memory units, as well as two power supplies, an input converter unit, and an input console, which used either a typewriter keyboard or an encoded magnetic tape (the first time such tape was used for computer input). Because of its dual processing, memory, and power units, the BINAC was actually two computers, each of which would continually check its results against those of the other in an effort to identify errors. The BINAC became operational in August, 1949. Public demonstrations of the computer were held in Philadelphia from August 18 through August 20.Impact The design embodied in the BINAC is the real source of its significance. It demonstrated successfully the benefits of the dual processor design for minimizing errors, a feature adopted in many subsequent computers. It showed the suitability of magnetic tape as an input-output medium. Its most important new feature was its ability to store programs in its relatively spacious memory, the principle that Eckert, Mauchly, and von Neumann had originally designed into the EDVAC. In this respect, the BINAC was a direct descendant of the EDVAC. In addition, the stored-program principle gave electronic computers new powers, quickness, and automatic control that, as they have continued to grow, have contributed immensely to the aura of intelligence often associated with their operation. The BINAC successfully demonstrated some of these impressive new powers in August of 1949 to eager observers from a number of major American corporations. It helped to convince many influential leaders of the commercial segment of society of the promise of electronic computers. In doing so, the BINAC helped to ensure the further evolution of computers. See also Apple II computer; BINAC computer; Colossus computer; ENIAC computer; IBM Model 1401 computer; Personal computer; Supercomputer; UNIVAC computer.

Bathysphere

The invention: The first successful chamber for manned deep-sea diving missions. The people behind the invention: William Beebe (1877-1962), an American naturalist and curator of ornithology Otis Barton (1899- ), an American engineer John Tee-Van (1897-1967), an American general associate with the New York Zoological Society Gloria Hollister Anable (1903?-1988), an American research associate with the New York Zoological Society Inner Space Until the 1930’s, the vast depths of the oceans had remained largely unexplored, although people did know something of the ocean’s depths. Soundings and nettings of the ocean bottom had been made many times by a number of expeditions since the 1870’s. Diving helmets had allowed humans to descend more than 91 meters below the surface, and the submarine allowed them to reach a depth of nearly 120 meters. There was no firsthand knowledge, however, of what it was like in the deepest reaches of the ocean: inner space. The person who gave the world the first account of life at great depths wasWilliam Beebe. When he announced in 1926 that he was attempting to build a craft to explore the ocean, he was already a well-known naturalist. Although his only degrees had been honorary doctorates, he was graduated as a special student in the Department of Zoology of Columbia University in 1898. He began his lifelong association with the New York Zoological Society in 1899. It was during a trip to the Galápagos Islands off the west coast of South America that Beebe turned his attention to oceanography. He became the first scientist to use a diving helmet in fieldwork, swimming in the shallow waters. He continued this shallow-water work at the new station he established in 1928, with the permission of English authorities, on the tiny island of Nonesuch in the Bermudas. Beebe realized, however, that he had reached the limits of the current technology and that to study the animal life of the ocean depths would require a new approach. A New Approach While he was considering various cylindrical designs for a new deep-sea exploratory craft, Beebe was introduced to Otis Barton. Barton, a young New Englander who had been trained as an engineer at Harvard University, had turned to the problems of ocean diving while doing postgraduate work at Columbia University. In December, 1928, Barton brought his blueprints to Beebe. Beebe immediately saw that Barton’s design was what he was looking for, and the two went ahead with the construction of Barton’s craft. The “bathysphere,” as Beebe named the device, weighed 2,268 kilograms and had a diameter of 1.45 meters and steel walls 3.8 centimeters thick. The door, weighing 180 kilograms, would be fastened over a manhole with ten bolts. Four windows, made of fused quartz, were ordered from the General Electric Company at a cost of $500 each. A 250-watt water spotlight lent by the Westinghouse Company provided the exterior illumination, and a telephone lent by the Bell Telephone Laboratory provided a means of communicating with the surface. The breathing apparatus consisted of two oxygen tanks that allowed 2 liters of oxygen per minute to escape into the sphere. During the dive, the carbon dioxide and moisture were removed, respectively, by trays containing soda lime and calcium chloride. A winch would lower the bathysphere on a steel cable. In early July, 1930, after several test dives, the first manned dive commenced. Beebe and Barton descended to a depth of 244 meters. A short circuit in one of the switches showered them with sparks momentarily, but the descent was largely a success. Beebe and Barton had descended farther than any human. Two more days of diving yielded a final dive record of 435 meters below sea level. Beebe and the other members of his staff (ichthyologist John Tee-Van and zoologist Gloria Hollister Anable) saw many species of fish and other marine life that previously had been seen only after being caught in nets. These first dives proved that an undersea exploratory craft had potential value, at least for deep water. After 1932, the bathysphere went on display at the Century of Progress Exhibition in Chicago. In late 1933, the National Geographic Society offered to sponsor another series of dives. Although a new record was not a stipulation, Beebe was determined to supply one. The bathysphere was completely refitted before the new dives. An unmanned test dive to 920 meters was made on August 7, 1934, once again off Nonesuch Island. Minor adjustments were made, and on the morning of August 11, the first dive commenced, attaining a depth of 765 meters and recording a number of new scientific observations. Several days later, on August 15, the weather was again right for the dive. This dive also paid rich dividends in the number of species of deep-sea life observed. Finally, with only a few turns of cable left on the winch spool, the bathysphere reached a record depth of 923 meters— almost a kilometer below the ocean’s surface.Impact Barton continued to work on the bathysphere design for some years. It was not until 1948, however, that his new design, the benthoscope, was finally constructed. It was similar in basic design to the bathysphere, though the walls were increased to withstand greater pressures. Other improvements were made, but the essential strengths and weaknesses remained. On August 16, 1949, Barton, diving alone, broke the record he and Beebe had set earlier, reaching a depth of 1,372 meters off the coast of Southern California. The bathysphere effectively marked the end of the tethered exploration of the deep, but it pointed the way to other possibilities. The first advance in this area came in 1943, when undersea explorer Jacques-Yves Cousteau and engineer Émile Gagnan developed the Aqualung underwater breathing apparatus, which made possible unfettered and largely unencumbered exploration down to about 60 meters. This was by no means deep diving, but it was clearly a step along the lines that Beebe had envisioned for underwater research. A further step came in the development of the bathyscaphe by 102 / Bathysphere Auguste Piccard, the renowned Swiss physicist, who, in the 1930’s, had conquered the stratosphere in high-altitude balloons. The bathyscaphe was a balloon that operated in reverse. Aspherical steel passenger cabin was attached beneath a large float filled with gasoline for buoyancy. Several tons of iron pellets held by electromagnets acted as ballast. The bathyscaphe would sink slowly to the bottom of the ocean, and when its passengers wished to return, the ballast would be dumped. The craft would then slowly rise to the surface. On September 30, 1953, Piccard touched bottom off the coast of Italy, some 3,000 meters below sea level.