Liver transplantation in tyrosinaemia type 1: the dilemma of timing the operation

Four children with tyrosinaemia type 1 received liver transplants. The metabolic disorder was corrected and all four had normal liver function on an unrestricted diet. Two children, transplanted at age five and seven years, proved to have occult hepatocellular carcinoma and both subsequently developed pulmonary metastases. One child was well 32 months after removal of a single pulmonary metastasis but the other child died with multiple metastases. The two younger children, transplanted at age 19 and 21 months, were well 28 and 44 months after operation, one after a second liver transplant. Our experience confirms the high risk of hepatocellular carcinoma in this disease and the potential value of early liver transplantation.     

Re-orientation and faster, directed migration of lens epithelial cells in a physiological electric field

The vertebrate lens drives current through itself in a pattern which concentrates current efflux at the lens equator. Lens epithelial cells (LECs) move into this region where they change shape and differentiate into lens fibre cells. The mechanisms underpinning these cell behaviors are unclear. We have attempted to mimic, in isolation, the effects which such electrical signals have on LEC behaviors, by culturing LECs in a physiological DC electric field (EF) similar to that in lens. Primary human (PHLECs), primary bovine (PBLECs) and a transformed human cell line (THLECs) all changed shape to lie perpendicular to the EF, the same orientation which LECs adopt with respect to the equatorial EF as they differentiate into lens fibre cells. Exposure to an EF also significantly increased the migration rate of all three LEC types. All three LECs also showed directed cell migration although, curiously, different cell types moved in different directions. PBLECs and THLECs showed voltage-dependent, anode-directed migration, with a response threshold between 100-150 mV mm(-1)and 25-50 mV mm(-1), respectively. Small sheets of THLECs also migrated anodally. By contrast PHLECs migrated cathodally with a response threshold below 100 mV mm(-1). Reversing the polarity reversed the migration direction for each cell type. These observations raise three possibilities: (1) that small electric field may be one of the cues regulating lens epithelial cell behaviors in vivo; (2) that altering the in vivo electric field by lens replacement may contribute to the aberrant migration of epithelial cells in conditions such as posterior capsule opacification and (3) that applying electric fields may be one way of controlling aberrant lens epithelial cell behaviors.     

Prospective surveillance of sympathetic ophthalmia in the UK and Republic of Ireland

AIMS: To establish current epidemiological data, risks, and interventional outcomes of newly diagnosed sympathetic ophthalmia (SO). METHODS: Prospective surveillance took place of all permanently employed ophthalmologists in the UK and Republic of Ireland by a monthly reporting card through the British Ophthalmological Surveillance Unit. Case ascertainment was made of newly diagnosed SO from July 1997 and questionnaire data were returned at baseline, 6 months, and 1 year after diagnosis. RESULTS: 23 patients with newly diagnosed SO were recruited over 15 months, corresponding to a minimum estimated incidence of 0.03/100 000. Baseline data were available on 18 patients, in whom SO occurred after surgery in 11 patients, after retinal surgery alone in six patients, and after accidental trauma in seven patients. 12 of the 16 patients with 1 year follow up had a visual acuity of 6/12 or better. Good visual outcome was related to prompt and adequate systemic immunosuppressive therapy. CONCLUSIONS: The incidence of sympathetic ophthalmia is very low. The main current risk is surgery, particularly retinal surgery, but visual prognosis is good if early diagnosis is made and rapid, adequate immunotherapy is commenced.     

Campath-1H therapy in refractory ocular inflammatory disease

BACKGROUND: Standard therapy for severe, immune mediated, ocular inflammation has significant side effects, and may fail to control the disease. T cell directed monoclonal antibody (mAb) therapy can provide long term remission of inflammatory disease in experimental models. The Campath-1H mAb was administered to patients with severe, refractory, ocular inflammation. METHODS: 10 patients with severe, refractory, non-infectious ocular inflammatory disease were treated with Campath-1H mAb. This is a fully humanised mAb which recognises the pan-lymphocyte antigen CD52. RESULTS AND DISCUSSION: Following Campath-1H therapy, all 10 patients showed an initial resolution of their ocular symptoms and signs. Long lasting remissions were achieved in eight patients, in whom baseline immunosuppression could subsequently be reduced to minimal levels. The possible mechanisms of action of Campath-1H therapy are discussed.     

Early treatment with cyclosporin in serpiginous choroidopathy maintains remission and good visual outcome

AIMS: To describe management and clinical outcomes of serpiginous choroidopathy treated primarily with cyclosporin at a tertiary uveitis referral centre METHODS: A case series of 14 eyes of seven patients with serpiginous choroidopathy with follow up ranging from 1.3 to 13 years is described. All patients had fundus lesions consistent with serpiginous choroidopathy, were investigated for systemic disease, had fluorescein angiography, and were treated with combined immunosuppressive therapy including cyclosporin. RESULTS: No patients suffered significant loss of acuity after starting systemic immunosuppression with cyclosporin as the primary agent. All but one patient achieved remission and were able to stop medications with no recurrences in the follow up period. Side effects from cyclosporin were well tolerated and there were no serious complications from immunosuppression. CONCLUSIONS: Cyclosporin is a safe and effective option with which to manage serpiginous choroidopathy. Significantly, adequate immunosuppression can result in clinical remission and cessation of therapy in some patients.     

Improved leukocyte tracking in mouse retinal and choroidal circulation

The purpose of this study is to develop a new method with which to visualize leukocyte dynamics in murine choroidal and retinal circulation. Both pigmented (B10.RIII) and non-pigmented (BALB/c) mice were used in this study. One hundred microl of 0.05% sodium fluorescein was injected via the mice tail vein to outline the vessel, followed by 150 microl (10(7) cells) C-AM labelled leukocytes. Fundus images were obtained with a confocal scanning laser ophthalmoscope. The dynamic image sequences were recorded simultaneously on videotape (S-VHS) and digitally at 25 frames per sec. The digital images were later analysed with a custom-made personal computer-based image analysis system. Both the choroidal and retinal circulation can be visualized in non-pigmented mice in the first few seconds of fluorescein angiography. However, the view of the choroidal and the retinal capillary circulation is soon blurred due to the rapid fluorescein leakage in the choroid. In contrast, in pigmented mice, retinal circulation is clear against the dark background of the choroid, while choroidal circulation is masked behind the pigment epithelial layer and cannot be seen at all. C-AM labelled leukocytes were clearly seen in the retinal circulation of all experimental mice and in the choroidal circulation of non-pigmented mice for as long as 30 min. The number of labelled circulating cells decreased as time clasped. Cells moved rapidly in the retinal arteries, slowing down or even stopping for a few seconds in the capillary system, and then moved slightly faster again through the postcapillary venules and veins. In non-pigmented mice, significant number of cells were seen to have arrested in the choroidal circulation. There was no difference between B10.RIII mice and BALB/c mice in vessel diameters, leukocyte velocities and shear stresses. This method allows the visualization of leukocytes and provides data on their behavior as they move through the choroidal and retinal circulation of non-pigmented mice, and in the retinal circulation of pigmented mice. It provides a valuable new tool for the investigation of real time leukocyte dynamics in murine retinal and choroidal microcirculations both under physiological conditions and during the development of ocular disease.     

Response of splanchnic and whole-body leucine kinetics to treatment of children with edematous protein-energy malnutrition accompanied by infection

BACKGROUND: Although the reduction in whole-body protein turnover and net protein loss induced by protein-energy malnutrition (PEM) has been well documented, it is unclear whether the protein-sparing mechanisms elicited by chronically inadequate intakes of dietary protein and energy are affected by the protein catabolic response to infection. OBJECTIVE: The objective of this study was to determine whether the presence of infection alters the PEM-induced reduction in whole-body protein metabolism. DESIGN: We determined whole-body leucine kinetics in 4 boys and 3 girls aged 6-15 mo with edematous PEM and infection approximately 3 d after admission (study 1), when they were both infected and malnourished; approximately 11 d after admission (study 2), when infection had resolved but they were still anthropometrically malnourished; and at recovery (study 3), when weight-for-length was at least 90% of that expected. RESULTS: The children had significantly less leucine flux in both study 1 and study 2 than they had in study 3. There were no significant differences in the amount of leucine released from protein breakdown or used for protein synthesis between study 1 and study 2. There were no significant differences in leucine balance or in either the amount or percentage of enteral leucine extracted by the splanchnic tissues among the 3 studies. CONCLUSIONS: When subjects are in the fed state, severe PEM induces a marked reduction in whole-body protein synthesis and breakdown rates, and the presence of infection does not alter this adaptation and hence the overall protein balance. A corollary is that children with severe PEM do not mount a protein catabolic response to infection.     

Comparing brain activation associated with isolated upper and lower limb movement across corresponding joints

It was shown recently that functional activation across brain motor areas during locomotion and foot movements are similar but differ substantially from activation related to upper extremity movement (Miyai [2001]: Neuroimage 14:1186-1192). The activation pattern may be a function of the behavioral context of the movement rather than of its mechanical properties. We compare motor system activation patterns associated with isolated single-joint movement of corresponding joints in arm and leg carried out in equal frequency and range. Eleven healthy volunteers underwent BOLD-weighted fMRI while performing repetitive elbow or knee extension/flexion. To relate elbow and knee activation to the well-described patterns of finger movement, serial finger-to-thumb opposition was assessed in addition. After identifying task-related voxels using statistical parametric mapping, activation was measured in five regions of interest (ROI; primary motor [M1] and somatosensory cortex [S1], premotor cortex, supplementary motor area [SMA] divided into preSMA and SMA-proper, and cerebellum). Differences in the degree of activation across ROIs were found between elbow and knee movement. SMA-proper activation was prominent for knee, but almost absent for elbow movement (P < 0.05); finger movement produced small but constant SMA-proper activation. Ipsilateral M1 activation was detected during knee and finger movement, but was absent for the elbow task (P < 0.05). Knee movement showed less lateralization in M1 and S1 than other tasks (P < 0.05). The data demonstrate that central motor structures contribute differently to isolated elbow and knee movement. Activation during knee movement shows similarities to gait-related activation patterns.     

Risk stratification post-myocardial infarction: is early coronary angiography the more effective strategy?

The primary management strategy for the post-myocardial infarction patient continues to be controversial despite published guidelines. In part, this is the consequence of study designs that are not directly applicable to individual patients, but also to the rapidly changing pharmacological and mechanical device armamentarium that rapidly renders clinical trial results obsolete within a few years. This review attempts to highlight those areas where there is consensus as well as to explicate those situations where common clinical practice appears to be in conflict with accepted guidelines.