Ribozymes: the first 20 years

Twenty years have passed since the first reports that certain RNAs mediate self-splicing and precursor tRNA processing reactions in the absence of proteins. An entire field emerged to learn how RNAs that lack the chemical versatility of amino acids nonetheless assemble into enzymes that accelerate chemical reactions with efficiencies that rival those of their protein counterparts.     

A family with x-linked hydrocephaly followed for 20 years: echographic prenatal diagnosis; elective abortion

In a Bickers-Adams family followed up for almost 20 years, authors report pregnancies of two propositus' sisters: echographic diagnosis of (normal) girls, of normal or affected boys and selective abortion in a case of dizygotic twin pregnancy with a normal girl and an affected boy.     

Presymptomatic testing for Huntington's disease in the United Kingdom. The United Kingdom Huntington's Disease Prediction Consortium.

OBJECTIVE--To evaluate the United Kingdom Huntington''s disease presymptomatic testing programme. DESIGN--Postal questionnaire survey to collect data on all tests performed by clinical genetics centres between 1987 and 1990. SETTING--Genetic centres providing presymptomatic testing in the United Kingdom. SUBJECTS--248 subjects at risk of Huntington''s disease who had presymptomatic testing at their request. MAIN OUTCOME MEASURES--Sex, age, prior risk, and risk after testing. RESULTS--The risk of carrying the Huntington disease gene was reduced for 151 (61%) of the applicants and raised for 97 (39%). 158 (64%) of the subjects were female and 90 (36%) male. The median age at which the results were given was 32.5 years. CONCLUSIONS--The demand for testing was lower than expected and may have reached its peak in 1990. The excess of low risk results was not fully explained by the age effect. All the genetics centres concerned have agreed a common service protocol which requires extensive pre-test counselling and post-test follow up. The worth of the procedure remains to be decided. The availability of a large body of pooled data from all the United Kingdom testing centres, which individually are likely to have only a few results, will form a valuable resource for monitoring the long term psychosocial impact of testing.     

An Audit of Behavioral Indicators of Poor Welfare in Kenneled Dogs in the United Kingdom

This survey-based study describes the prevalence and onset of behavioral indicators of poor welfare in dogs kenneled at United Kingdom rescue shelters. It describes key factors contributing to individual variation in behaviors. At 8 rescue shelters, staff trained in the care of nonhuman animals recorded daily whether dogs in their care displayed each of 15 behaviors. The study originally involved 302 dogs; for the first 14 days, it monitored only 148 dogs daily. The study observed dogs for a maximum of 6 weeks from admittance, observing all 15 behaviors at least once during the first 2 weeks (n = 148). The proportion of dogs observed to perform each behavior differed within the sample. The most commonly observed behavior (24.3% of dogs) was excessive barking. The remaining 14 behaviors ranged from listlessness (20.3%) to repetitive tail-chasing (1.3%). Over the 6 weeks, the proportion observed to pace repetitively and wall bounce increased. The proportion who lacked appetite and displayed fear-associated behavior decreased. Breed differences, gender, and age partially explained variability in the onset and prevalence of behavioral indicators of poor welfare in kenneled dogs.     

Success of a program of routine prenatal screening for hepatitis B surface antigen: the first 2 years.

Prenatal screening for hepatitis B surface antigen (HBsAg) restricted to women with defined risk factors for chronic hepatitis B virus (HBV) infection fails to identify many carriers. A centralized program of routine HBsAg screening for all pregnant women in Alberta was introduced in 1985. We collected and analysed data for the first 2 years of the program in Edmonton to determine the frequency of risk factors for HBsAg positivity, the proportion of multiparous HBsAg-positive women not identified in previous pregnancies, the efficiency and cost-effectiveness of providing immunoprophylaxis to infants at risk of HBV infection and the degree of success in inducing adequate protection. A total of 149 women (158 pregnancies) were found to be HBsAg positive. Risk factors were readily ascertainable for 85% of the women; the remaining 15% would not have been identified through risk-selective screening. The most common risk factors were Oriental ethnic origin, history of hepatitis, jaundice or multiple transfusions of blood or blood products, and occupational exposure to blood. Although 86% of the multiparous HBsAg-positive women had risk factors, only 7% had been identified in previous pregnancies. The Alberta program appears to be cost-effective. We conclude that only routine prenatal screening will identify all infants at risk of perinatal HBV infection and that a comprehensive public health program involving central laboratories, private physicians and public health staff can be highly effective and efficient in protecting infants against hepatitis B.     

Surveillance of AIDS in the United Kingdom.

The surveillance of cases of the acquired immune deficiency syndrome (AIDS) in the United Kingdom is described and a preliminary analysis made of the 1012 cases that were reported to the end of August 1987. Homosexuals were the largest risk group. For the first time it is possible to present cases by the date of diagnosis and by the regional health authority of residence. The rate of increase of new cases shows no sign of slowing down. One third of patients with AIDS lived in a different regional health authority from that in which their disease had been diagnosed. The geographical distribution varied with the risk group. The commonest presenting clinical feature at diagnosis was Pneumocystis carinii pneumonia. Kaposi''s sarcoma was considerably more common among homosexuals than among people in other groups at risk.     

Geochemistry and health in the United Kingdom.

Before the 1960s, comparisons between the distribution of trace elements in the environment and health in the United Kingdom were primarily confined to ad hoc studies in areas associated with particular agricultural disorders or with unusual human mortality or morbidity records. More recently, increasing interest in the importance of trace elements in crop and animal production and in the hazards of environmental pollution have created a need for more systematic geochemical data. Geochemical reconnaissance maps for England, Wales, Northern Ireland and parts of Scotland have demonstrated the extent of many known clinical trace element problems in agriculture and have also been valuable in delineating areas within which subclinical disorders may occur. Their application to studies on the composition of soils, food crops and surface waters in relation to public health has proved encouraging. Current knowledge and present investigations into environmental geochemistry and human health in the U.K. are reviewed, together with future research requirements.