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The hip is considered to be one of the main load bearing joints of the body. In the haemophilic patient joint bleeds can be catastrophic, leading to long-term joint degeneration and accompanying arthritis. In this review we explore the mechanisms of joint destruction, with particular consideration of the anatomy of the hip and how it may influence disease progression. We also review current strategies for treatment including hip replacement in the haemophilic patient and describe our experiences as a unit. Finally we evaluate future prospects in the management of hip disease in haemophilia.

Summary. Pseudotumours are a rare complication of haemophilia. Surgery undertaken for pseudotumour on a lesion that is subsequently found to be malignant can be expected to adversely affect patient outcome. We present six case reports found from a literature search of patients with haemophilia who underwent surgery on what was a primary malignancy misdiagnosed as a pseudotumour and give a subsequent discussion.

Bean common mosaic necrosis virus (BCMNV) was isolated from Centrosema pubescens, Crotalaria incana, Lablab purpureus, Phaseolus lunatus, Senna bicapsularis, S. sophera, Vigna vexillata and an unidentified Crotalaria species growing in Uganda. Thirteen distinct isolates were characterized using symptoms, pathogenicity in differential bean cultivars, serology, immunosorbent electron microscopy, and seed and aphid transmission. Some isolates conformed with the characteristics of previously described strains of BCMNV but others showed novel properties. All isolates reinfected the natural host from which they were obtained. The origin and ecological significance of these isolates is discussed.

Isolates of Pseudomonas syringae pv. phaseolicola from Africa and other bean growing areas were categorized into nine races on the basis of their reactions to eight differential cultivars following artificial inoculation. Eight hundred and ninety-three isolates representing 303 disease occurrences were initially identified as P.s. pv. phaseolicola by their pathogenicity to bean, cultural and serological characteristics and phage sensitivity. These tests also served to distinguish P.s. pv. phaseolicola from the closely related pathovars P.s. pv. glycinea and P.s. pv. syringae. Detailed race determinations were carried out on 175 selected isolates of p.s. pv. phaseolicola representative of the different geographical regions and hosts in which the pathogen was found and nine races were identified. A number of races (1,2,5,6 and 7) were distributed worldwide with race 6 predominant. Other races were found mainly in Africa; races 3 and 4 in East/Central Africa and races 8 and 9 in Southern Africa. Most isolates were obtained from the major host, Phaseolus vulgaris. Alternative natural hosts included 10 legume species representative of seven different genera (Cajanus cajan, Desmodium sp., Lablab purpureus, Macroptilium atropurpureum, Neonotonia wightii, Phaseolus acutifolius, P. coccineus, P. lunatus, Vigna angularis and V. radiata). Of these, Desmodium sp. constitutes a new host record.

SUMMARY Seasonal periodicity in the incidence of cowpea golden mosaic (CGM) and lima bean golden mosaic (LBGM), two whitefly-spread virus-like diseases, corresponded closely with fluctuations in population density of their vector, Bemisia tabaci, at two contrasting sites in southern Nigeria. Peak catches of the vector followed the onset of rains after very high temperatures during the dry season; populations declined abruptly with continuous, heavy rainfall. At Onne, B. tabaci infested legumes at emergence and remained and reproduced on them but at Ibadan infestation was delayed and there was no evidence of reproduction on legumes. B. tabaci preferred LBGM-susceptible lima beans (Phaseolus lunatus) to resistant ones and more pupae of B. tabaci occurred on CGM-susceptible cowpea (Vigna unguiculata) cultivars than on resistant ones but these observations did not relate to the yellow-sensitivity of whiteflies. Resistance to CGM in cowpea, and to LBGM in lima bean, was identified amongst germplasm exposed to natural infection. Resistance was, in each case, associated with lower disease incidence, slower spread and milder expression of symptoms relative to susceptible cultivars. Vector non-preference for resistant cultivars may have contributed to reduced secondary spread.

Leaf samples of black bryony (Tamus communis L.) from Devon, UK, showing various virus-like symptoms contained potyvirus-like particles (normal length c. 790 nm) and cytoplasmic cylindrical (pinwheel) inclusions. In immunoelectron microscopy, particles of most samples reacted with antiserum to dioscorea greenbanding mosaic virus, a potyvirus isolate from Dioscorea rotundata in Togo which is related to yam mosaic virus from the Ivory Coast. Potyvirus particles were not transmitted by sap or aphids (Myzuspersicae) from infected black bryony to black bryony seedlings or Nicotiana benthamiana. One sample from a symptomless plant of black bryony contained a potexvirus which formed massed virion aggregates in the cytoplasm of cells of black bryony, Nicotiana benthamiana and N. megalosiphon. Virions of the potexvirus (normal length 553 nm) contained a coat protein with an apparent molecular weight of 27.7 kd. The potexvirus differed from an Italian potexvirus isolate from black bryony by a serological differentiation index of 4 and gave only weak or no reactions with 23 other antisera to potexviruses, including dioscorea latent virus. The potexvirus caused systemic symptoms in only a few host plants and could be transmitted back to black bryony in which it caused no symptoms. It is provisionally named tamus latent virus.

An earlier paper described how the problem behaviours of adolescents who had experienced treatment at the Young People's Unit, Macclesfield changed. This paper describes the components of that experience, the clients' and referrers' evaluation of those components and their attitudes to the treatment received. The study occurred after an average post-discharge period of two years. A factor analysis produced two main clusters of attitudes relating to “personal growth” and “valuing of the unit experience”. Youngsters with positive attitudes towards the experience had significantly better outcomes. This finding is compared with a study of approved school boys. It is suggested that the components of the Young Peoples' Unit may be more suited to the maturational tasks of adolescence. The findings refute the justification that residential units have helped personal growth despite the continuation of problem behaviour. The study has implications for Health Service planning for disturbed adolescents and for community agencies' attitudes to the use of residential treatment.

SUMMARY Adult whiteflies (Bemisia tabaci) acquired the agent of cowpea golden mosaic (CGM-A) within 7 min and transmitted during 2 min inoculation access. Nymphs also acquired CGM-A and retained it through the pupal stage. Efficiency of transmission reached 90% when the acquisition period was increased to 36 h. The minimum latent period of CGM-A in B. tabaci was 8 h, and the median latent period (LP50) about 12 h. Transmission was generally intermittent and declined throughout the period of 21 days which was the maximum time insects remained infective. Female whiteflies were more efficient vectors than males. B. tabaci acquired CGM-A from plants inoculated only 60 h previously. The epidemiological implications of these findings are discussed.

We used a laboratory model of gouty synovitis giving quantitative dose-dependent results with urate injection intrasynovially into the knee joint of dogs. We found that when precautions were taken to prevent any possible endotoxin contamination of the urate crystals, they became significantly less active. Endotoxin by itself, from Escherichia coli, was very potent in causing pain and leukocytic infiltration into the knee joint. Such endotoxin was readily and firmly adsorbed onto urate crystals. A small dose of urate crystals that caused no pain by itself became very painful when the crystals were allowed to adsorb endotoxin in vitro. When this same small non-painful dose of urate crystals was given into the joint, and the dog also received endotoxin by the oral route, signs of pain arose very clearly. It is known that gouty patients even when in remission may have crystals of sodium urate in the synovial fluid. It would therefore appear possible that if such urate crystals were to adsorb an endotoxin passing from the gastrointestinal tract into the plasma, thence into the synovial space, the patients may develop an attack of gout.

SUMMARY Cultivars of cowpea (Vigna unguiculata) possessing tolerance to infection by cowpea mottle virus (CMeV) under screenhouse conditions exhibited both tolerance and resistance to infection by beetle vectors under field conditions. Resistance to infection was exemplified by delayed and reduced incidence of infection resulting from natural infection pressure, and appeared to be unrelated to vector feeding preference. This suggests that certain cowpea cultivars such as TVu 3901 possess more than one component of resistance (sensu Russell, 1978) to CMeV. Despite some correspondence between results from artificial (mechanical) and natural (vector) inoculation, we suggest that field evaluation is often an important adjunct to greenhouse screening for virus disease resistance since resistance mechanisms operative under field conditions may be overlooked in artificial screening programmes. In the susceptible cultivar TVu 612, when artificially inoculated, CMeV is transmissible through cowpea seed up to 0.4%. In only one instance was CMeV seed transmitted from natural infection. We suggest that apparent inefficiency in seed transmission may in part account for the restricted ecological and geographical distribution of CMeV.

A significant portion of the demand for industrial process heat can be met with solar energy. Whether this energy source is widely used will depend not only on its economic attractiveness, but also on the ease with which solar thermal systems interface with the remainder of the industrial plant. Foster Wheeler has recently designed solar thermal systems to supply hot water and process steam to industry and has nearly completed the construction of one of these. Drawing on this experience, this paper discusses selection of solar technologies that can best satisfy the user’s energy requirements and minimize interfacing problems.

Measurements are reported for the dielectric loss factor of the SCMC solutions over the frequency range 2 MHz to 50 MHz as a function of concentration of SCMC, concentration of added sodium chloride, molecular weight, and temperature. The results are in general agreement with those of other workers and are interpreted in terms of ionic theories in which motion of the diffuse counterions is the dominant feature.

Solar thermal systems capable of providing process heat to the industries that make up the Food and Kindred Products Group are now commercially available. Whether or not they will be adopted by these industries will depend not only upon further reductions in capital costs, but also upon the costs and availability of alternative fossil fuels, the operating and maintenance costs of solar thermal systems, and tax incentives.