Discovery of insect anti-juvenile hormones in plants.?2U

Two simple chromenes with anti-JH activity have been isolated and identified from the bedding plant Ageratum houstoianum. By contact and fumigation these compounds induce precocious metamorphosis and sterilization in several hemipteran species of insects. Certain holometabolous species are sterilized, forced into diapause, or both. Each of these biological actions is equivalent to removal of the corpora allata, which produce the JH's, and is reversible by treatment with exogenous JH. Thus, the action of these compounds is to stop the production or depress the titer of the JH's. To our knowledge, this is the first discovery of anti-JH, and we hope it will guide the way to the emergence of a fourth generation of safe and insect-specific pesticides.     

Histometric study of meat products. A literature review

In the present paper, the literature on the development of methods for histometric monitoring the quality of meats is reviewed. The value of specific techniques, statistical interpretation of results and the practicability of automation of histometric analysis are examined more closely. It is concluded from the study of the literature that histometric examination of meats allows an objective assessment of volume percentages of tissue components. When a distinct difference in contrast between various tissues is achieved by specific staining methods, developments in the field of image analysis systems will allow automation of the quantitative histological examination of meats.     

The initiation of simian virus 40 DNA replication in vitro

DNA replication is a complicated process that is largely regulated during stages of initiation. The Siman Virus 40 in vitro replication system has served as an excellent model for studies of the initiation of DNA replication, and its regulation, in eukaryotes. Initiation of SV40 replication requires a single viral protein termed T-antigen, all other proteins are supplied by the host. The recent determination of the solution structure of the T-antigen domain that recognizes the SV40 origin has provided significant insights into the initiation process. For example, it has afforded a clearer understanding of origin recognition, T-antigen oligomerization, and DNA unwinding. Furthermore, the Simian virus 40 in vitro replication system has been used to study nascent DNA formation in the vicinity of the viral origin of replication. Among the conclusions drawn from these experiments is that nascent DNA synthesis does not initiate in the core origin in vitro and that Okazaki fragment formation is complex. These and related studies demonstrate that significant progress has been made in understanding the initiation of DNA synthesis at the molecular level.     

Extraction and replacement of permanent pacemaker leads through occluded vessels: use of extraction sheaths as conduits--balloon venoplasty as an adjunct

Patients (pts) may present for lead extraction with symptomatic or asymptomatic subclavian vein or superior vena cava thrombosis. Replacement of permanent pacemaker leads (PPLs) in these pts may be difficult and may require accessing a new site. We examined the utility of replacing PPLs through completely occluded vessels using extraction sheaths as conduits through the total occlusion. Over six years, a total of 210 atrial and/or ventricular PPLs were extracted from 137 pts. Two pts presented with angiographically documented thrombotic occlusion of the subclavian vein. One additional pt. who had presented with a superior vena cava (SVC) syndrome, had a totally occluded innominate vein and SVC occlusion. Balloon venoplasty was used as an adjunct to dilate the SVC. In all pts, after PPLs were removed via a subclavian extraction sheath through the occluded vessel, the retained sheath was used to place a guide wire, then a peel away dilating sheath, to insert new PPLs, in each case on the side of total venous occlusion. Seven PPLs and two lead fragments were extracted, and five new PPLs replaced, ipsilateral to the venous occlusion. These data show that extraction of PPLs through thrombosed veins may be performed successfully and may not require replacing the leads through a new site. This technique spares the pt the need to access the opposite subclavian vein, and it avoids an excessive number of PPLs in the subclavian vein and SVC. The procedure illustrates an efficient means to reintroduce new PPLs with the potential to reduce associated morbidity, since repeat puncture of the subclavian vein is not required. Safety of the procedure as a whole must be considered with regard to the known risks of lead extraction, some complications of which may be substantial using current techniques.     

Lysine: arginine ratio of a protein influences cholesterol metabolism. Part 1--Studies on sesame protein having low lysine: arginine ratio

The effect of globulin fraction with a lysine: arginine (lys:arg) ratio 0.67, isolated from sesame (Sesamum Indicum) seeds on cholesterol metabolism was studied in rats fed cholesterol free and cholesterol containing diet and compared with casein (lys:arg ratio-2.0). Rats fed sesame seed globulin showed significantly lower concentrations of cholesterol in the serum and aorta. The decrease in serum was manifested in both HDL and LDL + VLDL fractions. There was increased cholesterogenesis in the liver as was evident from increased incorporation of labeled acetate into cholesterol and increased activity of 3-Hydroxy-3-methylglutaryl-CoA (HMG-CoA) reductase. Increased hepatic diversion of cholesterol to bile acid synthesis and increased fecal excretion of bile acids and sterols were also observed in rats fed sesame seed globulins. Rats fed sesame globulins also showed significantly higher activity of lipoprotein lipase in the heart and adipose tissue and that of plasma Lecithin: cholesterol acyltransferase (LCAT). These studies suggest that low lysine: arginine ratios of a protein exert hypocholesterolemic effects.     

Induced abortion in a Swiss canton from 1990 to 1993: implications for epidemiological surveillance

BACKGROUND: To describe abortion utilization in the Canton of Vaud (Switzerland) and to identify desirable changes in the data collection system to improve the epidemiologic monitoring METHODS: Retrospective survey of the 5600 abortion requests to the Canton Health Authority for resident women between 1990 and 1993. RESULTS: Nine women out of 1000 residents requested an abortion, but the abortion rate was higher among women of foreign origin compared to Swiss women (17/1000 vs. 6/1000, p < 0.0001). The proportion of terminated recognized conceptions was 127/1000, and the ratio of IVG to livebirths was 0.18. The abortion rate was lower during adolescence (6/1000) or after 40 years of age (1.8/1000), whereas the proportion of terminated conceptions was highest at these ages (527/1000 and 312/1000). Abortion utilization in Canton of Vaud is among the lowest. CONCLUSIONS: Although these indicators do reflect a satisfactory accessibility and use of family planning services, improvements could be made. A better knowledge of the causes (motives, contraceptive method, reproductive history) and of the consequences of abortion (psycho-social implications, medical complications) would allow to design more focused prevention strategies and to fit health services to current needs. Updating the 1942 Swiss legislation is also desirable.