The architecture of variant surface glycoprotein gene expression sites in Trypanosoma brucei

Trypanosoma brucei evades the immune system by switching between Variant Surface Glycoprotein (VSG) genes. The active VSG gene is transcribed in one of approximately 20 telomeric expression sites (ESs). It has been postulated that ES polymorphism plays a role in host adaptation. To gain more insight into ES architecture, we have determined the complete sequence of Bacterial Artificial Chromosomes (BACs) containing DNA from three ESs and their flanking regions. There was variation in the order and number of ES-associated genes (ESAGs). ESAGs 6 and 7, encoding transferrin receptor subunits, are the only ESAGs with functional copies in every ES that has been sequenced until now. A BAC clone containing the VO2 ES sequences comprised approximately half of a 330 kb 'intermediate' chromosome. The extensive similarity between this intermediate chromosome and the left telomere of T. brucei 927 chromosome I, suggests that this previously uncharacterised intermediate size class of chromosomes could have arisen from breakage of megabase chromosomes. Unexpected conservation of sequences, including pseudogenes, indicates that the multiple ESs could have arisen through a relatively recent amplification of a single ES.     

A de novo translocation t(3;17)(q26.3;q23.1) in a child with Cornelia de Lange syndrome.

A female infant with Cornelia de Lange syndrome and severe limb reduction defects is described. Chromosome analysis showed a de novo translocation with breakpoints at 3q26.3 and 17q23.1. This is the first reported case of a de novo translocation associated with this syndrome.     

Health effects and risks from 222Rn in drinking water

This paper presents an evaluation of the inhalation and ingestion doses from exposure to Rn and Rn progeny; an overview of the human and animal health-effects data; estimations of the cancer risks from Rn and Rn-progeny exposures; and suggested limits for Rn concentrations in drinking water and indoor air. We suggest that a rounded Rn-in-water concentration limit of 10,000 pCi/l can be supported by health-effects considerations alone, based on the conservative "tolerance dose" concept and other conservative assumptions regarding lung dose. A practical concentration limit (or action level) of 20,000 pCi/l has been derived by estimations of exposure distributions in the United States and in relation to current U.S. Environmental Protection Agency (EPA) standards for U-tailings-contaminated buildings. Research needed for resolution of the uncertainties in these estimates is suggested. We conclude that before a maximum contaminant level (MCL) for Rn in water can be firmly established, the broader issue of setting the MCL for Rn in indoor air must be addressed.     

EFFECT OF NITROGLYCERNE-INDUCED HYPOTENSION ON CANINE SPINAL CORD BLOOD FLOW

Twenty-four mongrel dogs were anaesthetized with pentobarbitoneand morphine sulphate. Neuromuscular blockade was achieved usingpancuronium. Spinal cord blood flow was measured using the radionuclidemicrosphere and hydrogen washout methods before, during, andfollowing nitroglycerine-induced hypotension. Heart rate, meanarterial pressure, cardiac output, pulmonary capillary wedgepressure, and acid-base balance were determined with each measurement.Mean arterial pressure was reduced by 50%. Spinal cord bloodflow, as measured by the microsphere method, increased duringthe period of hypotension, whereas values obtained using thehydrogen washout method were not significantly different fromthose at normotension. No significant change in spinal cordblood flow was detected by either method after the applicationof spinal distraction. Nitroglycerine acts predominantly onvenous capacitance vessels and it is postulated that perfusionpressure, and therefore flow, is maintained despite a reductionin arterial pressure. Presented in part at the Anual Meeting of the American Societyof Anesthesiologists, October 1985, San Francisco, California. ^*Shackleton Department of Anaesthetics, Southampton GeneralHospital, Shirley, Southampton, Hants SO9 4XY. Section of Orthopedic Surgery, Madison, Wisconsin.     

The Effects of Magnetic Resonance Imaging on Implantable Pulse Generators

The effects of magnetic resonance imaging were assessed on four dual chamber and two single chamber pulse generators. The tests were performed with a resistive, water-cooled magnet operating at 0.15 T. The 6.4-MHz radiofrequency (RF) field was operated at a maximum power of 1,000 watts with a period adjusted from 130 to 500 ms. Reed switch closure occurred in all six pulse generators tested when placed near the entrance of the magnetic resonance imaging scanner, and the generators reverted to asynchronous operation unless programmed to the "magnet off" mode. None of the pulse generators exhibited any alterations in programmed parameters or in the ability to be reprogrammed after RF pulsing. When the RF field was turned on, there was no change in the asynchronous paced cycle length in four pulse generators; however, during RF scanning there was rapid cardiac stimulation at the RF pulse period in one single chamber and one dual chamber pulse generator.     

Family planning increase in some African countries

Governments in sub-Saharan Africa, recognizing the economic and health benefits of slower population growth, have begun to adopt explicit policies aimed at reducing growth rates. More countries also are providing support to family planning programs. In 1985, more than 70% of the 402 million people living in sub-Saharan Africa lived in countries which have government-supported family planning programs. Yet, the coverage of many of these programs has been and remains limited. Reflecting low demand as well as problems in supplying contraceptive services, results from national-level surveys conducted in 10 countries between 1977-82 as part of the World Fertility Survey (WFS) program showed that approximately 5% of the currently married women aged 15-49 in these countries were using contraceptive methods. More encouraging are the results of surveys conducted in Botswana, Kenya, and Zimbabwe in 1984 as part of the international Contraceptive Prevalence Survey (CPS) program which demonstrate that family planning programs in Africa can be very successful. The CPS data show that substantial proportions of currently married women aged 15-49 in all 3 countries are currently practicing family planning. The level of current use of contraception reported in the CPSs in Botswana, Kenya, and Zimbabwe lay to rest the myth that women in sub-Saharan Africa are unwilling to use family planning. The majority of current users in all 3 countries use modern contraceptive methods. Most nonusers in the 3 countries know at least 1 family planning method. Male approval of family planning also seems to be common, although men are reported to be somewhat more likely than their wives to disapprove of family planning. Despite the fact that there is relatively widespread adoption of modern contraceptive method in Zimbabwe and Botswana as well as an increasing reliance on family planning methods in Kenya, the CPS results show that women in these 3 countries continue to have and want large families. The mean number of children ever born to women aged 45-49 ranges from 6.8 children in Botswana to 8.2 children in Kenya. Interest in planning their families is widespread among women in the 3 countries despite the high fertility expectations.     

The Potential of Anti-Bullying Efforts to Prevent Academic Failure and Youth Crime. A Case Using the Olweus Bullying Prevention Program (OBPP)

Prevention Science - The effectiveness of bullying prevention programs has led to expectations that these programs could have effects beyond their primary goals. By reducing the number of victims...     

Projected Economic Burden of Periprosthetic Joint Infection of the Hip and Knee in the United States

BackgroundIn addition to the significant morbidity and mortality associated with periprosthetic joint infection (PJI), the cost of treating PJI is substantial. Prior high-quality national estimates of the economic burden of PJI utilize data up to 2009 to project PJI growth in the United States through 2020. Now in the year 2020, it is appropriate to evaluate these past projections and incorporate the latest available data to better understand the current scale and burden of PJI in the United States.MethodsThe Nationwide Inpatient Sample (2002-2017) was used to identify rates and associated inpatient costs for primary total knee arthroplasty (TKA) and total hip arthroplasty (THA) and PJI-related revision TKA and THA. Poisson regression was utilized to model past growth and project future rates and cost of PJI of the hip and knee.ResultsUsing the most recent data, the combined annual hospital costs related to PJI of the hip and knee were estimated to be $1.85 billion by 2030. This includes $753.4 million for THA PJI and $1.1 billion for TKA PJI, in that year. Increases in PJI costs are mainly attributable to increases in volume. Although the growth in incidence of primary THA and TKA has slowed in recent years, the incidence of PJI and the cost per case of PJI remained relatively constant from 2002 to 2017.DiscussionUnderstanding the current and potential future financial burden of PJI for surgeons, patients, and healthcare systems is essential. There is an urgent need for efficacious preventive strategies in reducing rates of PJI after THA and TKA.