SCIENCE/TECHNOLOGY CONCENTRATES

Science New hepatitis Β vaccine effective A vaccine for hepatitis B, produced by recombinant DNA techniques, has been tested and proved effective, according to researchers from Merck Institute for Therapeutic Research [/. Am. Med. Assoc, 251, 2812 (1984)], The Merck vaccine was produced using a recombinant strain of the yeast Saccharomyces cerevisiae. The vaccine produced was purified by two different methods and given to two groups of hea l thy volunteers, numbering 15 and 22, at zero, one, and six months. Although one vaccine seemed to cause much less soreness at the injection site, both yielded similar results. By one month, 27 to 40% of those vaccinated had antibody, and by three months, 80 to 100% had antibody. Immunity increased markedly after the booster dose at six months. The results, the researchers say, are comparable to those of earlier studies using vaccine derived from human plasma. Although the latter has been shown to be safe and effective, they say, the supply is limited by available sources of suitable plasma.

Interlocked macroc yclic ligand synthesized An extremely short, convenient synthetic route to coordinating catenanes has been devised by research­ers at the Institut de Chimie in Strasbourg, France [/. Am. Chem. $oc, 106, 3043 (1984)]. Christiane O. Dietrich-Buchecker, Jean-Pierre Sauvage, and Jean-Marc Kern first make a copper(I) complex containing two interlocking di(p-phenol)phenanthroline ligands. A 14-atom polyether chain is then used to link to­gether the oxygens of each pair of phenols in both ligands. The resulting cuprocatenane is demetalated by treating it with tetramethylammonium cyanide, yielding a system of two interlinked macrocycles. The French chemists call this "new class of coordinat­ing molecules" a catenand. In the presence of metal ions such as l i th ium, copper , and silver, the diphenylphenanthroline subunits refit together to encage the metal ion. The formally copper(O) com­plex of this catenand, they say, is exceptionally stable.

Concern mounts over fate of Sakharov s Protests and concern continue to mount over the fate of Soviet physicist Andrei Sakharov and his wife, Elena Bonner. An International Coalition of Scientists for Sakharov organized demonstra­tions on May 30 at Soviet embassies and consulates in nine countries. Last week the American Associa­tion for the Advancement of Science passed a resolu­tion at its annual meeting urging the Soviets to end the Sakharovs' isolation and "allow them to seek medical care of their own choice." AAAS also urged its members and affiliated societies to send similar messages, and a petition at the meeting drew some 1000 signatures. Sakharov began a hunger strike on

May 2, demanding Bonner be allowed to get medical treatment abroad, and she may have joined his fast (C&EN, May 21, page 6). There are reports they are hospitalized in Gorki, but Soviet embassy offi­cials in Washington, D.C., last week simply told demonstrating scientists that both are in good health and are being monitored carefully, and medical facili­ties are available if needed. The U.S. scientists urge foreign physicians be allowed to examine the Sakharovs.

Chicken pox vaccine effective A vaccine for chicken pox has been shown to be effective and safe in healthy children in a large trial carried out by a group of researchers at the Universi­ty of Pennsylvania and Merck Sharp & Dohme Re­search Laboratories headed by Penn pediatrician Rob­ert E. Weibel [New Engl. J. Med., 310,1409 (1984)]. The group used an attenuated virus vaccine developed in Japan and called the Oka strain. It was administered to 956 children between the ages of one and 14 years who had not had chicken pox. Of the 914 children serologically confirmed to be susceptible to the disease, 468 were given vaccine and 446 received placebos. During a following nine-month surveillance period, 39 cases of chicken pox occurred in placebo recipients, none in those given the vaccine. Of those vaccinated, 17 had one or more exposures to chicken pox during the period and none contracted the disease. Although chicken pox normally occurs as a mild childhood disease, it can cause severe or even fatal illness—for example, from complications from bacterial infections or pneumonia. The researchers note that although the vaccine had been tested suc­cessfully before under various conditions, such as preventing disease after exposure, it hadn't yet been shown to be effective in protecting healthy children before exposure.

Technology Minerals recovered from clay-bearing ores A process for treating certain clay-bearing ores that permits the economic recovery of gold, uranium, and other minerals from those deposits has been developed by engineers at Uranium Pêchiney in France, a member of the Pêchiney Group. The appli­cable clays, the company says, are found in ore de­posits with either a high clay content or with some form of finely dispersed or swelling clays. The new process, it says, is a physical-chemical one that trans­forms the clays into a porous, granular material that is stable and holds up well under rugged processing operations. An improvement by a factor of 10 to 100 is gained in the ability of the ores to then be treated by traditional solid-liquid separation techniques such as filtration or settling. Another advantage, the company says, is reduced water content in the tail­ings.

June 4, 1984 C&EN 41