The demonstration of asymmetric hemoglobin hybrids by polyacrylamide electrophoresis.

A simpler, more economical technique than previously reported, that of conventional polyacrylamide gel electrophoresis alone, is described for the detection of asymmetric hemoglobin hybrids of the forms alphaXalphaYbeta2 and alpha2betaXbetaY when bloods from individuals with alpha and beta chain variants were examined. The presence of alpha chain variant hybrids, never before reported, is further evidence that hybrid formation is a more widespread phenomenon than has previously been thought of. Hybrids were found in artificial mixtures of hemoglobins and more importantly, are also reported here for the first time in bloods of individuals heterozygous for hemoglobin variants. These hybrid tetramers were as stable as the parent hemoglobins when examined under anaerobic conditions. The involvement of HbF in the formation of hybrids of the type alpha2betagamma is reported, and an analysis of the possible role of these as well as alpha2betaAbetaS hybrids in the sickling process is presented.

Technical, genetic, and ethical issues in screening and testing of African-Americans for hemochromatosis.

To define more precisely populations in which hemochromatosis is frequent to rare, problems of racial classification are introduced, with particular reference to Europeans and African-Americans. Because the category "Caucasian" includes a multitude of dissimilar peoples, the categories Europeans and European-Americans have been substituted for Caucasian, which is archaic. The background of discrimination in sickle hemoglobin programs for African-Americans are then analyzed, including, discrimination by employers, life insurance, and selective mandatory testing. Discrimination and selective testing of African-American employees of the Lawrence Livermore Laboratory continues today without prior consent, as it has since the 1970s. Dissimilarities between the genetics of hemochromatosis in Europeans and their descendants, Africans, and African-Americans are briefly analyzed. Finally, it is concluded that because hemochromatosis is unlike sickle hemoglobin in that it is potentially preventable and treatable, prevention and treatment principles should apply as in other diseases. Furthermore, because hemochromatosis is so common in European-Americans, discrimination, if practiced, would not be selective for African-Americans.

Is a national program to prevent sickle cell disease possible?

There is no specific therapy for sickle cell disease, and there is no evidence that sickle hemoglobin screening by conventional methods will lead to a significant reduction in the number of children with sickle cell disease. Thus it follows that if there is to be a national program to prevent sickle cell disease, the only recourse is one based on prenatal diagnosis and selective abortion of affected embryos or fetuses. Present-day dire poverty and callous health care public policies lead to the inescapable conclusion that a concerted attempt to alleviate poverty and its consequent adverse effects on maternal, neonatal, and infant mortality should take precedence over, or at the least coincide with, a national program to prevent sickle cell disease. On the other hand, it is argued that a woman should have the right to decide whether or not she wishes to have a child with a genetic disorder, and that recent advances in research on prenatal diagnosis, particularly when supported by public funds, should be made available to all, and not just the affluent.

Age determination from dental microstructure in juveniles.

The crypts outside St Bride's Church, London, contain a documented collection of skeletal remains dating from the mid-18th century. Some of these remains became mixed during post-war restoration work on the church. The worst example of such mixing involves ten infants that were boxed all together with their corresponding coffin plates. All the infants were aged between 1 and 4 years at death. Recognized skeletal aging criteria proved unsuccessful in identifying the bodies. A more precise method of age estimation was utilized in order to separate these individuals. Age was determined using the incremental markers found in dental microstructure which are thought to be formed in circadian and circaseptan rhythms. The resulting age estimates were compared with the real ages obtained from the coffin plates and death certificates. Confident identification was achieved in eight out of ten cases. This study illustrates the potential value of a little-known aging method in circumstances where commonly used methods have proved unsuccessful.

Growth and threshold weaning weights among captive rhesus macaques.

Interspecific analyses of infant growth and the time to maternal reconception (or weaning) demonstrate a consistent threshold for weaning weight at close to four times neonate weight, irrespective of the duration of lactation (Lee et al., [1991] J. Zool. Lond. 225:99-114). Intraspecific variation in the attainment of a threshold weaning weight was determined in a sample of 31 captive infant rhesus macaques, where growth between birth and subsequent parturition was measured along with information on maternal size, weight, and social characteristics. A threshold weaning weight was found, with infants attaining approximately 1,335 g at the time of reconception. Birth weights of the infants were influenced by maternal physical and social variables in that larger mothers, and alpha ranking mothers, produced larger neonates. Postnatal growth rate, which determined the attainment of the threshold weight, was independent of maternal size or condition, but was influenced by offspring sex and the probability of reconception. Future reproductive status of mothers was specifically related to differences in patterns of growth among the infants. Mothers who conceived again at 30 weeks had infants who grew more slowly after the first 12 weeks of life, especially if these infants were sons. Mothers in this colony appeared to make decisions about the need to sustain their infants' growth in relation to their ability to invest in current offspring, which may compromise their subsequent reproduction.

"Naturally-occurring" anti-K1: possible association with mycobacterium infection.

We report a case of "naturally-occurring" (nonred blood cell stimulated) anti-K1. The patient had never received a blood transfusion. Red blood cell antibody screening panels showed agglutination with K:1 red blood cells at room temperature and not in the anti-globulin test. Testing with 2-mercaptoethanol showed the antibody to be IgM. The antibody is "naturally-occurring" and may be associated with pulmonary tuberculosis.