active ingredient in endod, naming it“lemmatoxin.” Along with chemist Wil-fred A. Skinner, the researchers obtaineda patent on a different method.
But Lemma convinced his colleaguesthat because endod was “poor man’smedicine for a poor man’s disease,” itwas unseemly to profit from it. Accord-ingly, SRI donated its patent to a non-profit foundation that Lemma hoped toestablish in Ethiopia. “I felt we shouldget the farmers to grow it and use it lo-cally,” Lemma explains. He challengedthe British scientists to donate theirs aswell. The affair became diplomaticallyembarrassing; the scientists capitulated.
In 1974 the results from Adwa cameout: among 3,500 children between oneand six years in age, the prevalence ofschistosomiasis had fallen from 50 to 7percent. Yet to become widely adopted,endod needed the blessing of the WorldHealth Organization. That was notforthcoming. Ken E. Mott, who headsthe WHO’s schistosomiasis project, saysthe problem was Lemma’s patents: “Itwas uncertain how endod should be de-veloped, because somebody had a per-sonal [and financial] agenda in this.”
The WHO instead recommended achemical molluscicide marketed by Bay-er at $27,000 a ton in hard currency.(Endod sells for about $1,000 a ton.)The WHO questioned the safety of theberry, requiring that it pass tests costingmillions of dollars. But the WHO wouldnot help fund such tests, and in 1987Mott advised the Italian government notto provide research grants for endod.
The endod patents then belonged tothe Ethiopian Science Foundation, whichwas eventually subsumed by the Ethio-pian government. Lemma attributes theWHO’s animosity to a difficulty believ-ing that good science can emanate fromdeveloping nations. “The things donein Africa did not hold any weight in theU.S. or Canada,” Parkhurst agrees.
In 1976 Lemma joined the United Na-tions, serving on the Science and Tech-nology Commission. He convened twoendod conferences; funding started totrickle in from foreign-aid agencies andprivate organizations. The InternationalDevelopment Research Center (IDRC)in Ottawa offered to conduct the toxic-ity tests required by the WHO—provid-ed the Ethiopian government renounced
News and Analysis24 Scientific American April 1996
Tool TimeHumans, aside from the accident-prone co-median Tim Allen, are distinguished amonganimals for their ability to make and usetools. Even chimpanzees are no match for
man. The apes do usehandy objects but nev-er create them. Crows,
though, may well designthe items they use. Gavin R.Hunt of Massey University in
New Zealand has suggestedthat a species of crow in NewCaledonia—an island off Aus-
tralia—produces two highly stan-dardized implements: a twig having a hookedend and a stiff leaf with a barbed edge. Thecrows plunge the objects into holes to snareworms. Although other birds poke at preywith twigs, none shape them according tosome predetermined pattern.
Bacteria behind Clogged ArteriesA number of scientists have confirmed a linkbetween Chlamydia pneumoniae, a commonbacteria that causes respiratory infections,and atherosclerosis, a disease in which fattyplaques narrow the body’s arteries. Patientswith coronary artery disease typically harborantibodies to C. pneumoniae in their blood.And J. Thomas Grayston of the University ofWashington and his colleagues have foundchlamydia DNA in plaques from both thecoronary and carotid arteries. It is too soonto say how, but some suggest that the mi-crobe helps to promote arterial plaques.
Lead and DelinquencyA four-year study involving 301 public schoolboys has shown that exposure to lead makesyouths more aggressive. None of the childrenexamined suffered from clinical lead poison-ing, so the researchers measured theamount of metal accumulated in leg bones.Consistently, boys having higher lead levelswere deemed more violent by parents andteachers. Even when the scientists took in-telligence, socioeconomic status and medi-cal history into account, the lead-delinquen-cy link held, suggesting that lead pollutionmight elevate crime rates.
Re-creating a DinoroarComputer scientists at Sandia National Labo-ratories are helping paleontologists simulatethe sounds of a Parasaurolophus, a native ofNew Mexico during the Cretaceous period.The giant vegetarian sported a trombonelikecrest, filled with looping nasal passages thatsome presume served as a resonating cham-ber for the dinosaur’s voice. Using x-rays of anearly intact skull the paleontologists foundlast summer, the scientists are modeling theexact shape of its cavities on a computer.They hope to determine the sound Parasauro-lophus made, much in the same way the di-mensions of an instrument predict its pitchand tone.
Continued from page 22
Continued on page 26SOURCE: Centers for Disease Control and Prevention, 1991
FEWER THAN 6 PERCENT
PERCENTAGE OF BABIES WHO HAVE LOW BIRTH WEIGHTS
6 TO 7.9 PERCENT
8 PERCENT OR MORE
B Y T H E N U M B E R S
Low-Birth-Weight Babies
Low birth weight, which is defined as under 2,500 grams (or 5.5 pounds),
is the chief contributor to infant illnessand mortality. Of the more than 4.1 million
babies born in the U.S. in 1991, almost300,000 weighed less than 2,500 grams.Compared with those of normal weight,these infants are more likely to suffer
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Copyright 1996 Scientific American, Inc.
the endod patents. The test results, pub-lished in 1990, surprised no one. “It’sas harmless as soap,” states the IDRC’sDon de Savigny.
Along with a colleague, Lemma re-ceived the Right Livelihood Award
from the Swedish parlia-ment in 1989 and was fi-nally able to establish thenonprofit Endod Founda-tion. In 1990 the Univer-sity of Toledo in Ohiogranted Lemma an hon-orary degree. After Lem-ma’s acceptance speech, hishost, Harold Lee, asked ifendod might be effectiveagainst zebra mussels.These mussels choke sub-merged pipes in the GreatLakes, racking up billionsof dollars in damage. Lem-ma demonstrated how toapply the berries: the mus-sels died. In 1993 and1994 the university ob-tained patents on this useof endod, with Lemma asan investigator. The uni-
versity agreed to donate 10 percent ofits earnings to the Endod Foundation.
Last year Lemma requested that theUniversity of Toledo donate the patentsto the foundation, which would makethem freely available to African ven-
News and Analysis Scientific American April 1996 25
AKLILU LEMMAholds the famous endod berry, which kills the snails
that carry the schistosomiasis-causing parasite.
physical and emotional disabilities, includ-ing cerebral palsy, mental retardation,speech impairment, problems with visionand hearing, attention-deficit disorder, poorsocial skills, and behavioral difficulties. Re-cent research has even suggested that lowbirth weight can increase the chances ofcoronary heart disease, hypertension anddiabetes later in life. Particularly at risk arethe very low birth weight infants—thoseweighing less than 1,500 grams (3.3pounds)—who numbered about 53,000 in1991. Five-year mortality in this group isgreater than 20 percent, and those who dosurvive are more prone to complicationsthan are the moderately underweight.
Low birth weight is caused by diversefactors, among them low socioeconomicstatus, poor maternal nutrition, lack of pre-natal care, cocaine use, and cigarettesmoking, including passive smoking. Teen-agers are more likely to have low-birth-weight babies than are women in theirtwenties and thirties, and indeed, teenag-ers account for almost a quarter of low-birth-weight babies. Women weighing un-der 100 pounds are at higher risk than heavi-er women. Other variables, such as waterpollution, economic insecurity, and employ-ment as a manual worker in the electronics,metal and leather goods industries, mayalso contribute to low birth weight.
The strong concentration of low-birth-weight babies in the Southeast reflects inpart the large number of blacks living there.Black women account for 17 percent ofbirths but have 32 percent of the low-birth-weight babies and 38 percent of the verylow birth weight babies. Part of the differ-ence between black and white rates is at-tributed to less access to prenatal careamong blacks and to the fact that a largerproportion of black women give birth asteenagers.
But even when comparing black andwhite women of similar age, education andprenatal care, the rates of low-birth-weightbabies for black women are twice as highas for whites. There is, however, recent,tentative evidence that after several gener-ations of middle-class status, black womenare no more at risk than are their whitecounterparts.
There is great potential for improvementby reducing the rate of teenage pregnancyand by making prenatal care universal(more than 20 percent of all women re-ceive no prenatal care). Because unwant-ed babies are less likely to have receivedadequate prenatal care, the number of low-birth-weight babies could be reduced sub-stantially through more widespread avail-ability of family-planning services, includingabortion. —Rodger Doyle
KATH
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