Membrane-type matrix metalloproteinases 1 and 2 exhibit broad-spectrum proteolytic capacities comparable to many matrix metalloproteinases

Soluble proenzyme forms of the catalytic domains of membrane-type matrix metalloproteinases 1 and 2 (MT1-MMP and MT2-MMP) and a form of MT1-MMP containing the catalytic and hemopexin domains were expressed as soluble recombinant proteins. Purified, activated forms of the MT-MMP were shown to degrade fibronectin, tenascin, nidogen, aggrecan and perlecan. Only MT2-MMP showed activity against laminin. MT1-MMP retaining the hemopexin domain was able to specifically cleave native type-I and type-III collagens into the 3/4-1/4 fragments typical of the specific collagenases. The catalytic domain alone did not retain this activity. The MT-MMP did not degrade interleukin-1beta, but, similarly to many other MMP, could process a pro [tumor necrosis factor (TNF) alpha] fusion protein to release mature TNF. However, the latter was subsequently degraded into smaller fragments. These results demonstrate that, in addition to their ability to activate other MMP, such as progelatinase A/proMMP2 and procollagenase-3/proMMP13, MT-MMP degrade a number of extracellular matrix macromolecules. Their location at the surface of cells implies that they could play a significant role in the modulation of cell-matrix interactions.

Mechanisms for pro matrix metalloproteinase activation

The activation of pro matrix metalloproteinases (MMPs) by sequential proteolysis of the propeptide blocking the active site cleft is regarded as one of the key levels of regulation of these proteinases. Potential physiological mechanisms including cell-associated plasmin generation by urokinase-like plasminogen activator, or the action of cell surface MT1-MMPs appear to be involved in the initiation of cascades of pro MMP activation. Gelatinase A, collagenase 3 and gelatinase B may be activated by MT-MMP based mechanisms, as evidenced by both biochemical and cell based studies. Hence the regulation of MT-MMPs themselves becomes critical to the determination of MMP activity. This includes activation, assembly at the cell surfaces as TIMP-2 complexes and subsequent inactivation by proteolysis or TIMP inhibition.

Contributing factors in construction accidents

This overview paper draws together findings from previous focus group research and studies of 100 individual construction accidents. Pursuing issues raised by the focus groups, the accident studies collected qualitative information on the circumstances of each incident and the causal influences involved. Site based data collection entailed interviews with accident-involved personnel and their supervisor or manager, inspection of the accident location, and review of appropriate documentation. Relevant issues from the site investigations were then followed up with off-site stakeholders, including designers, manufacturers and suppliers. Levels of involvement of key factors in the accidents were: problems arising from workers or the work team (70% of accidents), workplace issues (49%), shortcomings with equipment (including PPE) (56%), problems with suitability and condition of materials (27%), and deficiencies with risk management (84%). Employing an ergonomics systems approach, a model is proposed, indicating the manner in which originating managerial, design and cultural factors shape the circumstances found in the work place, giving rise to the acts and conditions which, in turn, lead to accidents. It is argued that attention to the originating influences will be necessary for sustained improvement in construction safety to be achieved.

A prospective, randomized, double-blind, controlled clinical trial of enteral immunonutrition in the critically ill. Guy's Hospital Intensive Care Group

OBJECTIVE

To assess the effects of enteral immunonutrition (IMN) on hospital mortality and length of stay in a heterogeneous group of critically ill patients.

DESIGN

Prospective, randomized, double-blind, controlled clinical trial with an a priori subgroup analysis according to the volume of feed delivered in the first 72 hrs of intensive care unit (ICU) admission.

SETTING

A 13-bed adult general ICU in a London teaching hospital.

PATIENTS

A total of 398 patients were enrolled and data from 390 patients (IMN = 193, control = 197) were used for an intention-to-treat analysis. There were 369 patients (IMN = 184, control = 185) who actually received some enteral nutrition, of whom 101 patients (IMN = 50, control = 51) received >2.5 L within 72 hrs of ICU admission. This latter group was defined as the successful "early enteral nutrition" group.

INTERVENTIONS

Within 48 hrs of ICU admission, patients were randomized to receive either the IMN Impact (Novartis Nutrition), an enteral feed supplemented with arginine, purine nucleotides and omega-3 fatty acids, or an isocaloric, isonitrogenous control enteral feed.

MEASUREMENTS AND RESULTS

There was no significant difference in hospital mortality rate between the two groups on an intention-to-treat analysis (Impact group 48%, control group 44%) nor in any other predefined subgroup analysis. However, patients randomized to receive the IMN had higher Acute Physiology and Chronic Health Evaluation II scores (20.1 +/- 7.1 vs. 18.7 +/- 7.1 [p = .07] intention-to-treat [n = 390]; 20.1 +/- 7.2 vs. 18.5 +/- 7.1 [p = .04] received feed [n = 369]). Of the 101 patients achieving early enteral nutrition, those patients fed with the IMN had a significant reduction in their requirement for mechanical ventilation compared with controls (median duration of ventilation 6.0 and 10.5 days, respectively, p = .007) with an associated reduction in the length of hospital stay (medians 15.5 and 20 days, respectively, p = .03).

CONCLUSION

While the administration of enteral IMN to a general, critically ill population did not affect mortality, those patients in whom it was possible to achieve early enteral nutrition with Impact had a significant reduction in the morbidity of their critical illness.

Expression and functional analysis of G1 to S regulatory components reveals an important role for CDK2 in cell cycle regulation in human embryonic stem cells

One of the characteristic features of human embryonic stem cells (hESCs) is the competence for self-renewal and pluripotency. To date, little is known about cell cycle regulation in these cells and how the cell cycle machinery influences hESCs properties. A common feature of human, murine and primate ESCs is the presence of a short G1 phase, which has been viewed as a time window during which stem cells are exposed to differentiation signals. We used the hESCs differentiation model and comparisons to human embryonic carcinoma (EC) cells to study the key regulators of G1 to S transition in hESCs. Our studies show that hESCs express all G1-specific CYCLINs (D1, D2, D3 and E) and cyclin-dependent kinases (CDK) (CDK2, CDK4 and CDK6) at variable levels. In contrast to murine ESCs, most of the cell cycle regulators in hESCs show cell cycle-dependent expression, thus revealing important differences in the expression of cell cycle regulatory components between these two embryonic cell types. Knockdown of CDK2 using RNA interference resulted in hESCs arrest at G1 phase of the cell cycle and differentiation to extraembryonic lineages. This suggests an important role for CDK2 in cell cycle regulation in hESCs that are likely to bear significant impacts on the maintenance of their pluripotent phenotype.

A randomised prospective comparison of the Flamingo Wallstent and Ultraflex stent for palliation of dysphagia associated with lower third oesophageal carcinoma

BACKGROUND

Covered metallic oesophageal stents offer effective palliation of malignant oesophageal strictures. However, first generation devices were associated with a high rate of migration, particularly when used in the lower oesophagus.

AIM

To compare the rate of complications and palliative effect of two newer covered metallic oesophageal stents.

PATIENTS AND METHODS

We performed a prospective randomised study using two of these newer stent designs in the treatment of malignant lower third oesophageal tumours. Fifty three patients with dysphagia due to inoperable oesophageal carcinoma involving the lower third of the oesophagus were randomly selected to receive either a Flamingo covered Wallstent (Boston Scientific Inc., Watertown, Massachusetts, USA) or an Ultraflex covered stent (Boston Scientific Inc.). Dysphagia was scored on a five point scale, recorded before stent insertion, the day after, and at least one month later at follow up. Technical success, early and late complications (perforation, migration, severe gastro-oesophageal reflux, haematemesis, and reobstruction due to tumour overgrowth) were also recorded.

RESULTS

In both stent groups, a significant improvement in dysphagia score was seen both the next day post stenting and at late follow up (p<0.05). No significant difference was seen in the improvement in dysphagia between the two groups (p>0.1). The frequency of complications encountered in the two groups was similar. Three patients in the Ultraflex group required two stents at primary stenting.

CONCLUSION

The two types of stent are equally effective in the palliation of dysphagia associated with lower third oesophageal malignancy and the complication rates associated with their use are comparable.

A hierarchical quorum-sensing system in Yersinia pseudotuberculosis is involved in the regulation of motility and clumping

In cell-free Yersinia pseudotuberculosis culture supernatants, we have chemically characterized three N-acyl homoserine lactone (AHL) molecules, N-octanoyl homoserine lactone (C8-HSL), N-(3-oxohexanoyl)homoserine lactone (3-oxo-C6-HSL) and N-hexanoyl homoserine lactone (C6-HSL). We have identified, cloned and sequenced two pairs of LuxR/I homologues termed YpsR/I and YtbR/I. In Escherichia coli at 37 degrees C, YpsI and YtbI both synthesize C6-HSL, although YpsI is responsible for 3-oxo-C6-HSL and YtbI for C8-HSL synthesis respectively. However, in a Y. pseudotuberculosis ypsI-negative background, YtbI appears capable of adjusting the AHL profile from all three AHLs at 37 degrees C and 22 degrees C to the absence of 3-oxo-C6-HSL at 28 degrees C. Insertion deletion mutagenesis of ypsR leads to the loss of C8-HSL at 22 degrees C, which suggests that at this temperature the YpsR protein is involved in the hierarchical regulation of the ytbR/I locus. When compared with the parent strain, the ypsR and ypsI mutants exhibit a number of phenotypes, including clumping (ypsR mutant), overexpression of a major flagellin subunit (ypsR mutant) and increased motility (both ypsR and ypsI mutants). The clumping and motility phenotypes are both temperature dependent. These data are consistent with a hierarchical quorum-sensing cascade in Y. pseudotuberculosis that is involved in the regulation of clumping and motility.

Identification of futility in intensive care

Rising costs of intensive care and the ability to prolong the life of critically ill patients creates a need to recognise early those patients who will die despite treatment. We used changes in a modified APACHE II score (organ failure score) to make daily predictions of individual outcome in 3600 patients. 137 patients were predicted to die and of these, 131 (95.6%) died within 90 days of discharge from hospital (sensitivity 23.4%, specificity 99.8%); a false-positive diagnosis rate of 4.4%. 2 of the 6 survivors have subsequently died but 4 are alive with good quality of life. Patients predicted to die stayed 1492 days in intensive care and incurred 16.7% of total intensive care expenditure and 46.4% of the cost of all patients that died. Median survival after a prediction to die was 2 days, accounting for 62% of intensive care patient days in this patient group, giving an effective intensive care cost per survivor of UK 129,651 pounds. If used prospectively, this algorithm has the potential to indicate the futility of continued intensive care but at the cost of 1 in 20 patients who would survive if intensive care were continued.

Reproductive biology of seals

The reproductive biology of seals is fascinating in many aspects. As in most mammals, the time of onset of puberty in seals is variable. Once sexually mature, most but not all seals are seasonally mono-oestrous, with highly synchronized breeding seasons. They have evolved as either terrestrial or aquatic copulators, although a few species mate in a variety of habitats. Their mating strategies are diverse, ranging from serial monogamy to extreme polygyny. Gestation in seals is characterized by an embryonic diapause, which is obligate in most species. Reactivation of the blastocyst is followed by a placental gestation. All species of seal require a terrestrial (including ice floes) habitat for parturition. Lactation differs between the two seal families: phocid seals have an intense period of maternal investment, during which the mothers fast; otariid seals have a prolonged lactation during which intense bouts of suckling are interspersed by days of separation from their pups while the mother forages at sea. Although the anatomy and functional morphology of seals has been well described, less is known of the endocrinology of reproduction. This is due mainly to the logistical difficulties that researchers experience in collecting serial samples from a species that is relatively difficult to handle. This article reviews the basic anatomy and physiology, and our current understanding of the comparative aspects of reproduction in seals. Reproductive behaviours as well as the influences of environmental factors, such as photoperiod, nutrition and xenobiotics, are also discussed.

Screening for refractive errors in 6-9 month old infants by photorefraction

The method of isotropic photorefraction has been used in a trial of refractive screening of 6-9 month old infants. Data are presented on the calibration of the method against retinoscopic measurements and its reliability. In photorefractive screening of 1096 infants under cyclopentolate cycloplegia 5% were found to be hypermetropic (over +3.5 D), 4.5% myopic, and 1.3% anisometropic (over 1 D). These refractive errors were confirmed on retinoscopic follow-up (with the exception of a few anisometropes). Follow-up of controls shows that one small refractive error was missed in 52 infants. We conclude that photorefraction is a valid and practical screening technique. Longitudinal study of infants with refractive errors will assess the value of early detection, in particular for prediction and prevention of strabismus.

Anxiety and depression in the workplace: effects on the individual and organisation (a focus group investigation)

BACKGROUND

While the prevalence of anxiety and depression has increased, little is known of the impact on working life. The aim of this study was to explore the effects of anxiety and depression and the treatment for these conditions on performance and safety in the workplace.

METHOD

Nine focus groups were conducted with employees who had suffered anxiety and depression. A further 3 groups comprised staff from human resources and occupational health. The sample comprised 74 individuals aged 18-60 years, from a range of occupations. Results were presented to a panel of experts to consider the clinical implications.

RESULTS

Workers reported that the symptoms and medication impaired work performance, describing accidents which they attributed to their condition/medication. Respondents were largely unprepared for the fact that the medication might make them feel worse initially. Employees were reluctant to disclose their condition to colleagues due to the stigma attached to mental illness.

LIMITATIONS

People who had experienced problems with managing their symptoms and medication at work are more likely to volunteer to participate in such a study than those who had a satisfactory experience. Also, the researchers had no background information on severity of mental health problems of participants.

CONCLUSIONS

Anxiety and depression were associated with impaired work performance and safety. The authors consider the implications for health care and the management of mental health problems at work.

A specific IgG in Graves' ophthalmopathy and its relation to retro-orbital and thyroid autoimmunity

An IgG (ophthalmopathic immunoglobulin) that binds to retro-orbital antigen was identified in serum from patients with active Graves' ophthalmopathy, and its nature and specificity were investigated. Dose related binding of this immunoglobulin to retro-orbital antigens prepared from guinea pig harderian gland or porcine eye muscle was found, which could be abolished by prior incubation with antigen. The immunoglobulin did not bind to thyroid membranes, thyroid microsomes, or thyroglobulin or interact with liver, skeletal muscle, or fat membranes. Serum with high activity of thyrotrophin binding inhibiting immunoglobulin did not react with retro-orbital antigen, and this activity was not affected by preincubation of the serum with retro-orbital antigen. Thyroid stimulating hormone was also without effect on retro-orbital antigen. It is concluded that Graves' ophthalmopathy is associated with a specific ophthalmopathic immunoglobulin that reacts with retro-orbital antigen as distinct from thyroid antigens, and that the autoimmune response is directed towards retro-orbital antigens. This suggests that the ophthalmopathy is an entity distinct from autoimmune thyroid disease.

A single amino acid change makes a rat neuronal sodium channel highly sensitive to pyrethroid insecticides

Two amino acid substitutions in a housefly sodium channel, L1014F in domain IIS6 and M918T in the IIS4-S5 linker, have been identified in kdr and super-kdr pyrethroid-resistant phenotypes, respectively. Unlike their native insect counterparts, mammalian sodium channels are only weakly sensitive to pyrethroids. Do the sodium channels of mammal and pyrethroid-resistant housefly share similar structural characteristics that account for their low pyrethroid sensitivities? We report here that substitution of isoleucine for methionine at position 874 (equivalent to the super-kdr site 918 in the housefly) in the rat IIA alpha-subunit causes a 100-fold increase in sensitivity.

Mutations of the para sodium channel of Drosophila melanogaster identify putative binding sites for pyrethroids

The effects of two pyrethroids on recombinant wild-type and mutant (pyrethroid-resistant) Na+ channels of Drosophila melanogaster have been studied. Three mutations that confer resistance (kdr/superkdr) to pyrethroids were inserted, either individually or in combination, into the para Na+ channel of D. melanogaster: L1014F in domain IIS6, M918T in the IIS4-S5 linker, and T929I in domain IIS5. Channels were expressed in Xenopus laevis oocytes and the effects of the pyrethroids permethrin (type I) and deltamethrin (type II) on Na+ currents were investigated using voltage clamp. The Na+ channels deactivated slowly after deltamethrin treatment, the resultant "tail" currents being used to quantify the effects of this pyrethroid. The Hill slope of 2 for deltamethrin action on the wild-type channel and the mutant L1014F channel is indicative of cooperative binding at two or more sites on these channels. In contrast, binding to the mutants M918T and T929I is noncooperative. Tail currents for the wild-type channel and L1014F channel decayed biphasically, whereas those for M918T and T929I mutants decayed monophasically. The L1014F mutant was approximately 20-fold less sensitive than the wild-type to deltamethrin. Surprisingly, the sensitivity of the double mutant M918T+L1014F to deltamethrin was similar to that of M918T alone, whereas the sensitivity of T929I+L1014F was >30,000-fold lower than that of T929I. Permethrin was less potent than deltamethrin, and its binding to all channel types was noncooperative. The decays of permethrin-induced tail currents were exclusively monophasic. These findings are discussed in terms of the properties and possible locations of pyrethroid binding sites on the D. melanogaster Na+ channel.

Going down to the local: incorporating social organisation and political culture into assessments of decentralised health care

The social organisation and political culture of the society in which an organisation is embedded can have major effects on the way in which organisational policy is implemented and on how that organisation functions. Research on health sector reforms has paid scant attention to this aspect. If the claims made for decentralised management in the health sector are to be evaluated seriously, it is critical to develop concepts and methods to evaluate not only the formal organisation and the outputs of the health system, but also the aspects of local social organisation and political culture within which that local health system is embedded that may mediate their relationship. The paper explores three cases of district health systems in Northeast Brazil in order to identify aspects of local social organisation and political culture that appear to influence the implementation of the reforms and thereby potentially impact upon the quality of the care provided. The results of the study indicate the importance that aspects of local social organisation and political culture may exert on the operations of a decentralised health system. Key aspects identified are: the space for autonomy; the space for local voice in political life; personalized and institutionalised influences on autonomy and local voice; differences of involvement of health staff with the district; different spaces of acceptable practice and accountability. These factors are seen to moderate the intent of the health reforms at all stages in their implementation. Three possibilities are discussed for the nature of the interaction in terms of cause and effect between the formal organisation of the health system and its local context. Seeing this relationship as one of a dialogue offers some cautious optimism for the potential of the reform agenda. The paper closes with suggestions on how to take this line of research forward.

Ophthalmopathic immunoglobulin in patients with Graves' ophthalmopathy

An IgG which binds specifically to retro-orbital antigen has been detected in patients with Graves' ophthalmopathy. By means of an assay which detects ophthalmopathic immunoglobulin (OIg) in patients' serum with an antigen prepared from porcine retro-orbital muscle, levels of OIg above the normal reference range were found in 21 of 33 (64%) patients with active untreated ophthalmopathy, in 3 of 12 (25%) with active disease already receiving steroid treatment, and in 3 of 18 (16%) with longstanding inactive eye disease. OIg was found in only 1 of 22 thyroid patients without eye disease. There was no correlation of OIg with thyrotropin-binding-inhibiting immunoglobulin nor with thyroid microsomal antibody, and there was no clear association with thyroglobulin antibody. Ophthalmopathy seems to be distinct from Graves' hyperthyroidism and the autoimmune response is directed to retro-orbital antigens.

Estrone and estradiol-17 beta concentration in tissue of the scleractinian coral, Montipora verrucosa

Spawnings of scleractinian corals are affected by light, temperature, and other environmental cues, but no studies elucidate physiological mechanisms that regulate coral gametogenesis. We hypothesized that estrogens may act as bioregulators of coral reproduction. Estrone (E1) and estradiol-17 beta (E2) concentrations were measured in homogenates of tissue and skeleton from M. verrucosa. Tissue samples were collected monthly throughout the year, and more frequently in July and August around spawning. Steroids were extracted with diethyl ether, purified via celite chromatography and assayed with radioimmunoassay. Non-specific binding in coral tissue varied with sample weight and was elevated relative to standards. Monthly mean E1 ranged from 20-70 ng E1 g ash-free dry weight (AFDW)-1, with highest values in April. Smaller asynchronous peaks occurred in early July, prior to spawning. Monthly mean E2 ranged from 8-25 ng E2 g AFDW-1, with highest values in February and March. Peaks in E2 preceded peaks in E1, indicating metabolism of a pool of estrogen. E1 was positively correlated with protein concentration, which is consistent with a bioregulatory role of estrogens. Estrogen peaks in spring and prior to the July spawn corroborate our hypothesis that estrogens regulate coral gametogenesis and spawning.

Diurnal patterns of cortisol and thyroid hormones in the Harbor seal (Phoca vitulina) during summer and winter seasons

A leading hypothesis for the dramatic population decline of the Alaskan harbor seal over the last 2-3 decades have related environmental changes to a decrease in the quality or quantity of available prey. If harbor seals are experiencing some sort of nutritional stress, it is important to understand the physiological and endocrine mechanisms controlling metabolic homeostasis in this species. The purpose of this research project was to determine whether circadian patterns of cortisol and total and free thyroxine (T(4)) and triiodothyronine (T(3)) are present in the harbor seal during the summer and winter seasons, and identify how they might alter metabolic rate and maintenance of body reserves. This study was carried out at the Alaska SeaLife Center in Seward, Alaska in June 2000 and January 2001. Blood samples were obtained every 2-3 h over a 24-h period through in-dwelling catheters inserted the day before sampling. The presence of a diurnal rhythm was determined by comparing levels between ante meridian (12 am to noon) and post meridian (noon to 12 midnight) time periods. Mean daily cortisol concentrations were not significantly different between seasons, but cortisol displayed a circadian rhythm only during the summer. Mean concentrations of cortisol (51.5 ng/ml+/-20.3) in the summer hours of ante meridian differed significantly from levels in the hours of post meridian (28.5 ng/ml+/-17.4). Neither total and free T(4), nor T(3), displayed a diurnal rhythm in either season. However, tT(4), tT(3), and fT(3) levels were significantly higher in the winter than in the summer. There was no seasonal effect on fT(4) levels. The absence of a circadian rhythm of cortisol during the winter may have been a result of the limited amount of daylight as well as the continual need to produce metabolic heat as a by-product of gluconeogenesis. Higher levels of thyroid hormones in the winter indicate an adaptive mechanism to cope with the low temperatures of winter.

Monitoring of progesterone in captive female false killer whales, Pseudorca crassidens

The present study describes progesterone profiles to enhance understanding of general reproductive patterns in three female captive false killer whales and analyzes potential relationships in progesterone concentrations between plasma, salivary, and ocular secretions. Plasma progesterone concentrations reflected ovarian activity for most of the year, with increased concentrations in the spring and summer, indicating that the two adult female false killer whales were spontaneous ovulators and seasonally polyestrus. Elevated progesterone concentrations were determined at intervals, for up to 10 consecutive months, in one female. There were also varying periods of no apparent ovarian activity from 3 to 10 consecutive months. Correlation coefficients between progesterone concentrations in plasma, salivary, and ocular secretions ranged between -0.23 and 0.16. It is concluded that blood collection should not be replaced by salivary or ocular secretion collection for the measurement of progesterone in the false killer whale.

Effect of radioiodine on stimulatory activity of Graves' immunoglobulins

The effects of 131I therapy on the activity of thyroid stimulating antibody (TSAb) and thyrotrophin binding inhibiting immunoglobulin (TBII) in nineteen patients with Graves' disease have been studied. Prior to 131I administration TSAb was detected in 84%, and TBII in 68% of patients. Following 131I administration TSAb and TBII were detectable in 100% of patients. The elevation 3 months after treatment of the means of both the TSAb and TBII indices for the group of nineteen patients was highly significant compared with pre treatment values. All the patients went into remission during the course of the study and the TSAb index declined in all patients, becoming undetectable in eleven; TBII also declined in most patients but remained detectable in thirteen. The study furthermore afforded the opportunity for a direct comparison of binding with stimulatory activity. These results show that after 131I therapy for Graves' hyperthyroidism there is a transient increase in TSAb as well as TBII, followed by a decline, and that the measurement of binding and stimulatory activities are in good general agreement.

Health impact assessment as an agent of policy change: improving the health impacts of the mayor of London's draft transport strategy

OBJECTIVE

To increase the positive and mitigate the negative health impacts of the mayor's draft transport strategy for London.

DESIGN

A rapid prospective health impact assessment (HIA) of the penultimate draft of the strategy, using a review commissioned by the regional director of public health; an appraisal of congestion charging; and a participatory workshop. Two audits of changes were performed to assess the impact on policy of the HIA process.

SETTING

Regional government policy development.

INTERVENTION

Recommendations from the rapid HIA were fed back into the drafting process.

MAIN OUTCOME MEASURE

Changes (a) between the penultimate draft and the draft for public consultation and (b) between that and the final mayoral strategy.

RESULTS

The draft transport strategy published for consultation differed in a number of respects from the previous version. Almost all the recommendations from the HIA were incorporated into the final strategy. Significant changes included promoting sustainable travel plans for workplaces and schools; giving priority to infrastructure and services that benefit London's deprived communities; increased emphasis on promoting walking and cycling and reducing reliance on private cars; and a commitment to track the health impacts of the final strategy and its implementation. Specific additions included re-allocating road space.

CONCLUSION

HIA was successful in influencing the transport strategy for London, resulting in several improvements from a health viewpoint. HIA is an effective method both for bringing about significant change in policy proposals and in increasing policy makers' understanding of determinants of health and hence in changing attitudes of policy makers.

The stimulation of thyroid hormone secretion in vitro by thyroid-stimulating antibodies

A new simple technique is described for the in vitro assay of thyroid-stimulating antibody (TSAb) in serum. Thyroid slices are incubated with serum in two-compartmental dialysis pot, followed by measurement of the thyroid hormone concentration in the dialysis fluid by RIA. Heat-inactivated normal serum applied directly to the tissue has no effect on the basal level of response. A dose-dependent relationship is demonstrated for both TSH and TSAb. Serum from patients with untreated Graves' hyperthyroidism is clearly shown to stimulate thyroid hormone secretion. Porcine thyroid tissue has been used and responds well to TSAb. This technique not only has the advantage of simple methodology, but also reflects the biological activity of TSAb. Therefore it will prove useful for further studies of the significance of TSAb and the pathogenesis of Graves' disease.