We discovered a highly virulent variant of subtype-B HIV-1 in the Netherlands. One hundred nine individuals with this variant had a 0.54 to 0.74 log 10 increase (i.e., a ~3.5-fold to 5.5-fold increase) in viral load compared with, and exhibited CD4 cell decline twice as fast as, 6604 individuals with other subtype-B strains. Without treatment, advanced HIV—CD4 cell counts below 350 cells per cubic millimeter, with long-term clinical consequences—is expected to be reached, on average, 9 months after diagnosis for individuals in their thirties with this variant. Age, sex, suspected mode of transmission, and place of birth for the aforementioned 109 individuals were typical for HIV-positive people in the Netherlands, which suggests that the increased virulence is attributable to the viral strain. Genetic sequence analysis suggests that this variant arose in the 1990s from de novo mutation, not recombination, with increased transmissibility and an unfamiliar molecular mechanism of virulence.

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The isolation of optically active lactones from animal and vegetable fats is described. As the optical activity of lactones isolated from butterfat is ascribed to their biological origin, special attention was paid to the optical purity of the lactones. Lactone mixtures from butterfat, goat milk fat and coconut oil were found to be dextrorotatory, those from babassu oil levorotatory. The total lactone mixtures of two out of three samples of palm‐kernel oil were slightly dextro‐, whereas that of the third one was levorotatory. After isolation of the individual lactones from the mixtures, levo‐ and dextrorotatory lactones were demonstrated side by side in palm‐kernel oil and in coconut oil. The δ‐lactones of palmkernel oil were levo‐, the γ‐isomers dextrorotatory. In coconut oil only the δ‐C12 lactone was levorotatory, whereas the other components of the δ‐series were dextrorotatory. The specific rotation [a]d of the chemically pure lactones was considerably lower than that of model lactones, this being an indication of their optical impurity. As it was evident from model experiments that no racemization of the lactones occurred during isolation, it follows that both optical antipodes are formed in the fats in unequal amounts, via different pathways.

VAN DER VEN, AND A. P. DE JONGE. Preparation of optically active y-and 6lactones by microbiological reduction of the corresponding keto acids. Appl. Microbiol. 11:389-393. 1963.-It was found, by means of simple screening methods, that several yeasts (Saccharomyces and Candida), molds (Cladosporium), and bacteria (Sarcina) are able to reduce keto acids to hydroxy acids, which are easily converted into lactones. Chemical analysis showed that some of the microorganisms (Saccharomyces and Candida) produce dextrorotatory lactones and others (Cladosporium and Sarcina) produce levorotatory lactones. High yields of dextrorotatory (both y-and 6-lactones) were obtained by using Saccharomyces cerevisiae. The physical properties of the carefully distilled lactones obtained indicated high purity and high optical purity.