Studies on parasitic castration: Occurrence of a gametogenesis-inhibiting factor in extract of Zoogonus lasius (Trematoda)

Testes of nonparasitized Ilyanassa obsoleta were maintained in vitro in a modification of the medium originally devised by Burch and Cuadros [Nature (London)206, 637–638 (1965)] in order to ascertain whether a saline extract of the daughter sporocysts of Zoogonus lasius would cause the inhibition of spermatogenesis. This parasite is known to cause parasitic castration of I. obsoleta in nature. It has been ascertained that after 96 hr of incubation with the parasite extract the incorporation of [³H]thymidine is inhibited in some spermatogonia. This represents the first experimental evidence that some molecule(s) of parasite origin may be responsible for chemical parasitic castration.     

Molecular epidemiology of anthrax cases associated with recreational use of animal hides and yarn in the United States

To determine potential links between the clinical isolate to animal products and their geographic origin, we genotyped (MLVA-8, MVLA-15, and canSNP analysis) 80 environmental and 12 clinical isolates and 2 clinical specimens from five cases of anthrax (California in 1976 [n = 1], New York in 2006 [n = 1], Connecticut in 2007 [n = 2], and New Hampshire in 2009[n = 1]) resulting from recreational handling of animal products. For the California case, four clinical isolates were identified as MLVA-8 genotype (GT) 76 and in the canSNP A.Br.Vollum lineage, which is consistent with the Pakistani origin of the yarn. Twenty eight of the California isolates were in the A.Br.Vollum canSNP lineage and one isolate was in the A.Br. 003/004 canSNP sub-group. All 52 isolates and both clinical specimens related to the New York and Connecticut cases were MLVA-8 GT 1. The animal products associated with the NY and CT cases were believed to originate from West Africa, but no isolates from this region are available to be genotyped for comparison. All isolates associated with the New Hampshire case were identical and had a new genotype (GT 149). Isolates from the NY, CT and NH cases diverge from the established canSNP phylogeny near the base of the A.Br.011/009. This report illustrates the power of the current genotyping methods and the dramatically different epidemiological conditions that can lead to infections (i.e., contamination by a single genotype versus widespread contamination of numerous genotypes). These cases illustrate the need to acquire and genotype global isolates so that accurate assignments can be made about isolate origins.     

Polymorphisms for human chromosomes 1 and Y: Feulgen and UV DNA measurements

Some individuals show considerable length differences between the homologues of chromosome no. 1 and length variations for the Y chromosome have also been found. The variabilities in length appear to be localized in the heterochromatic regions. The aim of this study was to distinguish between two phenomena postulated to contribute to length variations: (1) a genetically determined uncoiling of a chromosomal region, and (2) an increase in the chromosomal DNA content. By cytophotometry of photographic negatives the integrated absorbance of polymorphic and normal no. 1 and Y-chromosomes was compared, using chromosome no. 2 as standard. Microphotometry was carried out on both unstained chromosomes at 265 nm and on Feulgen-stained chromosomes at 546 nm. Both methods showed that the length polymorphisms studied are, in general, characterized by an increase in the chromosomal DNA.     

Propranolol concentrations in plasma after insertion into the vagina.

Six healthy women participated in a study of the concentrations of propranolol achieved in plasma after insertion of the drug into the vagina. In four of the women the concentrations were also determined after administration by mouth. The area under the concentration curve for propranolol administered per vaginam was significantly greater than that after oral administration. There were small significant reduction in systolic blood pressure, pulse rate, and forced expiratory volume in one second after vaginal administration but these did not cause any symptomatic side effects. The tolerability of the vagina to drugs and the safety of this form of treatment remain to be determined. Probably further studies of the contraceptive effects of propranolol should be conducted with the dextro isomer of the drug.