Usually, it doesn't matter muchwhich brand you specify...

Unless you're aspectroscopist

It's not something we usually advertise, but there are a couple of other excel-lent brands of laboratory chemicals. However, some MC&B product lines aredefinitely superior to those offered by the competition. MC&B SpectroqualitySolvents are an example. Spectroquality solvents are manufactured to higherquality standards using special techniques developed by MC&B. They arebetter for spectrophotometry and fluorometry. We'd appreciate it ifyou specifyMC&B whenever you order any reagents-there's a special reason when youorder solvents for spectrophotometry.

Norwood, Ohio / Los Angeles, California / East Rutherford, N. J.

aggregated into complicated networks.Cervical mucus contains an iron-bindingprotein "lactoferrin" which is presentin many external secretions and seminalplasma, but absent in blood serum, con-centrated follicular fluid, amniotic fluid,and the placenta. Lactoferrin seems toprotect the mucosa against damage byheavy metals and bacterial infectionsand perhaps plays a role in spermcapacitation.The diagnosis of zygosity of offspring

is based on sex, structure of placentalmembranes, and the enzyme systems ofthe blood and placenta. A monochorialplacenta may be considered certainproof of monozygosity. Of particularinterest are the relatively great numberof cardiac malformations and the hemo-dynamic aspects of different types ofplacental anastomosis.The intrauterine device may cause

distention of the uterine lumen and im-pair the tonicity of the myometrium;this interferes with implantation of theblastocyst. The incorporation of a pro-gestin, melengestrol acetate, in silasticintrauterine devices causes prolonged re-tention of the devices in the uteri ofrats and rabbits, which usually expelidentical devices without added pro-gestin. The development of a hormone-releasing device which acts mainly onthe uterus, can be retained longer, andsuppresses bleeding might broaden theusefulness of this contraceptive methodin man.The condom and the spermicidal

vaginal contraceptive methods still usedin several countries lessen sexual pleas-ure and may leak or rupture duringintercourse. In Japan a soluble condomcontaining the spermicidal compound iskept in aluminum foil to prevent dryingand is applied to the glans penis beforeintercourse.An effort must be made to define the

impact of contraceptives on generalhealth and metabolic and endocrinefunctions. Current methods of data col-lection have failed to provide an ade-quate basis for statistical evaluation.Epidemiological surveillance is impor-tant, but to be valid the reporting ofadverse reactions must be complete andunbiased. Collection and correlation ofdata is a task for national and inter-national health agencies. Information onfertility and the health of children bornto mothers previously treated with oralcontraceptives should be collected sys-tematically on an international scale.

Habitual abortion may be due tocervical incompetence, or an under-developed or overdeveloped uterus.

SCIENCE. VOL. 1621036

Patients treated during pregnancy withlong-acting progestins show menstrualdisorders which may vary from amenor-rhea to menometrorrhagias after de-livery. Aging of the ova, which results inembryonic death, may include chrono-logic aging of ovarian eggs, or intra-follicular or intraoviductal overripenessof eggs. Infants of young fathers sufferhigh stillbirth rates, but not high ratesof childhood mortality.

Several methods are used to makepregnancy possible in cases of oviductalocclusions: implantation of the ovaryinto uterine cornua, formation of anoviduct from neighboring tissues, im-plantation of an intact oviduct fromanother woman, transfer of fertilizedova into the uterine lumen, and insertionof an artificial oviduct.

Several chemical criteria are used toevaluate the condition of human semen:sperm nucleic acid is related to malefertility; acid and alkaline phosphatasesare related to prostatic function; fruc-tose is related to the function of theseminal vesicles; and the electrophoreticpattern of normal and pathological sem-inal proteins is diagnostic. There areother analytical methods for diagnosingejaculatory disturbances and certain an-atomical defects such as absence of vasadeferentia or occlusion of ejaculatoryducts.

Congenital malformations account fora high percentage of child morbidityand mortality. Repair of congenital mal-formations is spectacular, desirable, andnecessary. Planned prevention of mal-formations is still in its beginning stages,and eugenic prophylactic measures arevery limited. Many apparently viableand normal embryos and fetuses diebecause of adverse maternal or environ-mental factors and are eliminated byspontaneous abortion. Certain malfor-mations of the cardiovascular systemare incompatible with prenatal life, butare well tolerated in postnatal life. Onthe other hand, many malformations ofthe brain, eye, and extremities are welltolerated in prenatal life, but becomepathogenic after birth. Metabolic dis-turbances like phenylketonuria and ga-lactosemia are tolerated in utero, butbecome disastrous after birth.The amniotic fluid is obtained (amnio-

centesis) for antenatal diagnosis of fetaldisorders, such as Rh incompatibility.After delivery of congenitally mal-formed babies, further pregnancies canbe examined by amniocentesis and chro-mosomal analysis of fetal cells. Amnio-centesis may play an important role ingenetic counseling.29 NOVEMBER 1968

With this steady flow HOLTERM pumpyou handle

two fluids simultaneouslyat different rates (0 2500 ml/hr)The RL175 Holter bilateral roller pump offers laboratory workersand clinicians the means of pumping two discrete systems atlinearly related rates.A high and a low RPM range for the roller head provide

optimum control of pumping rates. Within each range,speed is infinitely variable. Internal solid state voltage regulationcontributes to a pumping accuracy of ±1%. Delivery volumevs. pressure curves are flat up to 290 mm Hg positive pressureand 200 mm Hg negative pressure.

Precision molded silicone elastomer pumping chambers elimin-ate the hysteresis effects that make PVC and polyethylene un-desirable in precision work. Useful life of the chambers is wellover 2,000 hours. Provided in two internal diameters, they areautoclavable and easily interchangeable. Because the chambers arecompletel occluded by the head rollers, the RL175 does not"dribble" when shut off. You stop and start with identical, virtuallynon-pulsatile flows.The circuitry and mechanical safety features of the RL175 suit it

admirably to unattended operation.Write or call today for full information and prices on this versa-

tile laboratory pump, and on other pumps and devices fromExtracorporeal.

EXTRACORPOREAL MEDICAL SPECIALTIES, INC.

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1037

ScanningDensity

GradientElectrophoresis

Easy determination of electro-phoretic mobilities as well asphysical separation of mixturesand quantitative microanalyticalresults can be obtained with theISCO Model 210 Density GradientElectrophoresis apparatus. Mi-crogram size samples can readilybe separated. Low sample con-centration permits the use ofdilute buffers, allowing a wideoperational temperature range offrom 0 to 250 C.Between preset periods during

which the density gradient col-umn is subjected to an electricfield, the column is automaticallyraised and lowered past a narrowbandwidth UV absorbance scan-ning monitor. Quantitative resultscan be obtained from these scansor from a final chart record madeautomatically at the conclusionof migration as separated speci-men components are dischargedinto a fraction collector for fur-ther assay.

For *more information pleaserequest Brochure E37J.

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Recent advances in genetics and de-velopmental biology make it possible toinfluence specific characteristics of theoffspring: control of sex, mastery ofgenetic disease, propagation of specificgenotypes, or establishing the biologicalbasis for specialized skills. Knowledgeof deoxyribonucleic acid biochemistryhas been applied to specific develop-mental situations.The diagnosis of fetal sex chromatin

may be useful for antenatal care incases of sex-linked hereditary disorders.Makamo and de Watteville examinedthe fetal membrane of 8184 infants todetermine the nuclear sex. Sex chro-mosomal anomalies occurred in 0.13percent of the cases. The incidence ofXXY, XXX, and XO in newborns isestimated to be 1/750 in males, 1/1000in females, and 1/3000 in females, re-spectively.At the congress a new organization

was formed, the International Federa-tion on Fertility Associations, an out-growth of the International Fertility As-sociation. P. H. de Watteville (Switzer-land) has been elected to head the newfederation.

E. S. E. HAFEZWashington State University, Pullman

Fermentation Industries:Promising Future Predicted

A promising future for the fermenta-tion industries was forecast by C. G.Heden (Karolinska Institute, Stock-holm) and A. F. Langlykke (RutgersUniversity) at the Third InternationalFermentation Symposium held at Rut-gers University (2-6 September 1968).The meeting was sponsored by the Di-vision of Microbial Chemistry andTechnology of the American ChemicalSociety, and the Fermentation Indus-tries Section of the Applied ChemistryDivision of the International Union ofPure and Applied Chemistry (IUPAC).The theme of the Symposium "Fer-

mentation Advances in the Light ofRecent Theoretical Progress in Micro-biology, Biochemistry and Engineering"was examined. Two major benefits de-rived from this symposium by the 800participants (representing 20 countries)were the opportunity to hear reportsof recent advances in fermentationtechnology and to hear of prospectsfor the immediate future of the fer-mentation industries.New fermentation products and

processes which might reach commer-

1038

cial-scale production in the near futurewere discussed. These included Monen-sin, an antibiotic with coccidiostaticproperties, which is comparable in po-tency and has lower toxicity than manyof the synthetic organic chemicals nowused for this purpose; glucose isomer-ase, a streptomycete enzyme convertingglucose to fructose, which is now usedto prepare syrups for the confectionarytrade; a new rennin-like enzyme from afungal source found acceptable to re-place the calf-stomach-derived enzymeused in cheese making and now in shortsupply; a new process for obtainingerythorbic acid (iso-ascorbic) by directmold fermentation of glucose; a micro-bial conversion of pentaerythritdl totris (hydroxymethyl) acetic acid; atartaric acid producing fermentation ofglucose; and two new microbial prod-ucts with insecticidal properties.The microbial conversion of hydro-

carbons to edible, useful protein wasdiscussed in more than a dozen paperswith emphasis on technology requiredfor economic production of the micro-bial cells. The biological value of pro-teins and the varieties of useful hydro-carbons (including methane) were alsodiscussed in detail. With the world sugarshortage on the horizon, N-paraffinswere proposed as economically feasiblesubstrates for fermentation processesproducing the food supplements gluta-mic acid and ribonucleic acid.

Three discussion panels considered adiversity of problems which may affectthe fermentation industries now and inthe future. The possibilities of usingenzymes to carry out useful transfor-mations of steroids, antibiotics, and ter-penes, as well as the utility of enzymesattached to fixed supports, attractedmuch attention. The panel discussionon patent protection of fermentationprocesses emphasized the differences inthe various countries in the world andthe limitations of preventing infringe-ment. A group of tissue-culture expertspresented information on tissue cultureas a fermentation process for produc-tion of cells, enzymes, protein hor-mones, and steroid hormones.The Fourth International Fermenta-

tion Symposium will be held in Tokyo,Japan, in 1972 under the sponsorshipof the IUPAC and several Japanesefermentation societies. Information con-cerning this meeting may be obtainedfrom Professor G. Terui, Osaka UFn-versity, Osaka, Japan.

D. PERLMANSchool of Pharmacy, Universityof Wisconsin, Madison 53706

SCIENCE, VOL. 162