Single-step RT real-time PCR for sensitive detection and discrimination of Potato virus Y isolates.

Potato virus Y (PVY) has a worldwide distribution and infects several economically important crops from the Solanaceae family. The emergence and spread of the PVYNTN strain, which is the causative agent of potato tuber necrotic ringspot disease (PTNRD), has lead to large economic losses and highlighted the need for accurate discrimination of the different PVY strains. Detection and differentiation of PVY isolates is mainly based on a combination of ELISA, RT-PCR and bioassays; however, PVYNTN isolates are particularly difficult to differentiate from standard PVYN without the use of time-consuming bioassays. A strong correlation has been identified previously between the ability to induce PTNRD and the presence of a recombination point in the virus coat protein. An RT real-time PCR assay has been developed to enable detection of isolates with the recombination point, therefore, enabling rapid differentiation between potentially tuber necrotic PVYNTN isolates and standard PVYN isolates. The assay is also able to detect the presence of PVYO isolates. To aid with routine testing, immuno-capture and post-ELISA virus release were introduced; when coupled with RT real-time PCR the sensitivity of the assays were up to seven orders of magnitude higher than ELISA. The assay was shown to be a suitable method for rapid large-scale diagnostic testing of PVY in different types of plant material including tubers, and specific screening for potentially tuber necrotic recombinant isolates.

Clinical usefulness of an aftercare worker for psychotic patients discharged from half-way houses in Hong Kong.

BACKGROUND: The aim was to assess the clinical usefulness and economic viability of an aftercare worker for psychotic patients discharged from half-way houses in Hong Kong. METHOD: A sample of 32 chronic psychotic patients was provided with a full-time aftercare worker. A matched control group received no such service. RESULTS: The experimental group was found to have greater and better employment prospects, better mental status with less hospitalisation and less law-breaking behaviour than the control group. Some of these benefits were converted into economic terms and the tangible costs incurred in the project were calculated. CONCLUSIONS: The provision of an aftercare service is clinically useful and economically viable.

Methodological difficulties encountered in determining the service needs of a 'hidden population'.

This report describes some of the methodological difficulties encountered in carrying out a 4-year project designed to locate and determine the service needs of adults in Hong Kong with an intellectual disability over the age of 45 years. The project located 263 adults with an intellectual disability across a wide spectrum of Hong Kong society. The methodological difficulties encountered in attempting to locate these individuals and conducting the survey to determine the service needs of this 'hidden population' included: an interviewing process that was extremely tedious and which took much longer than originally anticipated; problems encountered in trying to convince potential subjects to be interviewed; contending with different dialects and speech comprehension; conceptions of options and choices that were often very limited because of the highly restrictive lifestyle of the individual surveyed; and discrepancies between the views of carers and adults with intellectual handicaps. Data analyses were also hampered by problems in constructing a reliable registry, computerization because of translations of names and responses, and respondent refusals as a result of concerns over stigmatization. The authors offer a discussion of these problems as learning aids for future research.

The living conditions of psychiatric patients discharged from half-way houses in Hong Kong.

This paper reports on a study of the living environment of 64 psychiatric patients discharged from half-way houses in Hong Kong. The majority were living in a deprived situation compared to that of their neighbours. They were leading a very monotonous life throughout the year; the walls of their homes were dirty and very plain; and some even ate scraps from a neighbouring bakery. Many did not have any social life at all, and their hobbies were smoking, watching television and gambling. Their neighbours, by comparison, had hobbies such as floriculture, birds and goldfish; decorated their walls with pictures and had newspapers and periodicals in their houses; more often had telephone facilities, wardrobes and sofas; used town gas rather than kerosene stoves; and were more likely to have electrical appliances, especially an iron, refrigerator and shaver. Judged by their income from employment or from public assistance, the 'quality of life' (QOL) of these patients should not have been in such a desperate state. They lacked guidance and instruction in their management of money, and the care of their homes. It is proposed that an aftercare worker might improve the QOL of these discharged psychiatric patients.

Calcium-binding affinity and calcium-enhanced activity of Clostridium thermocellum endoglucanase D.

Clostridium thermocellum endoglucanase D (EC 3.2.1.4: EGD), which is encoded by the celD gene, was found to bind Ca2+ with an association constant of 2.03 x 10(6) M-1. Ca2+ stimulated the activity of EGD towards swollen Avicel by 2-fold. In the presence of Ca2+, the Kd of the enzyme towards p-nitrophenyl-beta-D-cellobioside and carboxymethylcellulose was decreased by 4-fold. Furthermore, Ca2+ increased the half-life of the enzyme at 75 degrees C from 13 to 47 min. Since the 3' sequence of celD encodes a duplicated region sharing similarities with the Ca2+-binding site of several Ca2+-binding proteins, a deleted clone was constructed and used to purify a truncated form of the enzyme which no longer contained the duplicated region. The truncated enzyme was very similar to EGD expressed from the intact gene with respect to activity, Ca2(+)-binding kinetics and Ca2+ effects on substrate binding and thermostability. Thus the latter parameters do not appear to be mediated through the duplicated conserved region.

The fibrinolytic system in pre-eclampsia.

Plasma fibrinolytic activity and plasma inhibitory activity against urokinase and tissue activator were measured in primigravidae with moderate or severe pre-eclampsia and in gestation-matched primigravidae with uncomplicated pregnancy. The mean levels of fibrinolytic activity and inhibitory activity against urokinase and tissue activator did not differ significantly between the pre-eclampsia and uncomplicated pregnancy groups. The pattern of inhibitory fractions of plasminogen-depleted plasma from pre-eclamptic and uncomplicated primigravidae after gel filtration on sephadex G-100 was similar.

Blood levels of proteinase inhibitors in pre-eclampsia.

The blood levels of alpha 2-macroglobulin, alpha 1-antitrypsin, CT inactivator, antithrombin III and alpha 2-antiplasmin were measured in 18 primigravidae with moderate or severe pre-eclampsia and in 18 gestation-matched primigravidae with uncomplicated pregnancy. The mean levels of the proteinase inhibitors did not differ between the pre-eclampsia and uncomplicated pregnancy groups.

The inhibition by plasma of urokinase and tissue activator-induced fibrinolysis in pregnancy and the puerperium.

The activity of urokinase and tissue activator on fibrin plates was inhibited by plasma from women in the third trimester of pregnancy to a greater extent than by non-pregnant plasma. Pregnancy also inhibited the amidolytic activity of urokinase. The high molecular weight fractions of pregnancy plasma gel filtered on Sephadex G-200 showed comparable inhibitory activity against urokinase as fractions for non-pregnant plasma; in contrast with non-pregnant plasma, the lower molecular weight fractions of pregnancy plasma were markedly inhibitory against urokinase. Plasma exposed to lysine-Sepharose to remove plasminogen and then fractionated on Sephadex G-100 provided a pattern of three areas of inhibition against tissue activator similar to that seen in non-pregnant plasma. The urokinase-inhibitory activity of lower molecular weight fractions of plasma separated on Sephadex G-200 fell within 1 hr of delivery and fell further over the following 18 to 30 hr.

Influence of cider on the fibrinolytic enzyme system.

Ingestion of 750 ml cider inhibited plasma fibrinolytic activity: unfermented apple juice appeared to have some inhibitory effect, but this did not reach statistical significance. Cider inhibited urokinase-induced clot lysis in a concentration-dependent manner; the inhibitory activity was heat-stable and non-dialysable. The fibrinolytic activities of plasmin, urokinase and, more markedly, tissue activator on fibrin plates were inhibited by cider in a concentration-dependent manner. The amidolytic activity of plasmin was also inhibited in the presence of cider.

Extension of the use of measures of cognitive style to moderately-severely retarded trainees in a field setting.

This study investigated the feasibility of using measures of cognitive tempo with 66 institutionalized moderately-severely retarded adolescents and adults in the field settings of three Activity Centres--one rural and two urban. The Matching Familiar Figures Test and the Porteus Maze Tests could, with characteristic modifications, be administered to this type of population, the typical response being slow and error-prone. Either one or both could contribute usefully to the prediction of work performance in the groups concerned, but would have little to offer over and above conventional individual tests of general intelligence.

The Porteus Maze Test in the measurement of reflection/impulsivity.

This study investigated the use of the Porteus Maze test as a measure of reflection/impulsivity when used with both normal and retarded subjects. Study 1 (N = 90) provided sample data for three equal groups of 30 adolescent students in the regular school. These were defined as above average, average, and below average in general intelligence. In addition to measures of qualitative and quantitative scoring, data were also available from Kagan's Matching Familiar Figures Test and a specially constructed Teachers' Rating Scale. The below-average group showed a significantly more impulsive approach. There was evidence of the concurrent validity of Porteus Maze as shown in substantial correlations with the other variables. Study 2 investigated the use of the Porteus Maze with 41 mildly intellectually handicapped adolescents. The data were in keeping with those obtained from a below-average group in Study 1.

Effects of modification of conceptual tempo on acquisition of work skills.

This study investigated the effects of modification of conceptual tempo on the skilled performance of a group of mildly intellectually handicapped adolescents receiving training in a work preparation centre (N, 41). On the basis of performance on Kagan's Matching Familiar Figures Test the group was divided into two subgroups, reflective, impulsive and then further divided through random allocation to control and experimental conditions. The two experimental groups received a training program designed to promote self-generation of strategies, using self-verbalization to induce a more reflective approach. The control groups received the normal training program of the centre. The criterion measure taken at pre- and posttest was a collation task standardized so as to provoke response uncertainty. Analysis of residual gain scores derived from the two testing occasions indicated that the experimental groups improved significantly more than the controls and that the improvement generalized to their performance on the Porteus Maze and Matching Familiar Figures Test. Contrary to expectation, however, the effect of training did not bring about significant differential improvement for impulsive as against reflective subjects. Both benefited from the training. On the basis of delayed posttests, no generalization was apparent.