Primary total knee replacement in patients with mental disability improves their mental health and knee function: a prospective study

We assessed the effect of mental disability on the outcome of total knee replacement (TKR) and investigated whether mental health improves post-operatively. Outcome data were prospectively recorded over a three-year period for 962 patients undergoing primary TKR for osteoarthritis. Pre-operative and one year Short-Form (SF)-12 scores and Oxford knee scores (OKS) were obtained. The mental component of the SF-12 was stratified into four groups according to level of mental disability (none ≥ 50, mild 40 to 49, moderate 30 to 39, severe < 30). Patients with any degree of mental disability had a significantly greater subjective physical disability according to the SF-12 (p = 0.06) and OKS (p < 0.001). The improvement in the disease-specific score (OKS) was not affected by a patient's mental health (p = 0.33). In contrast, patients with mental disability had less of an improvement in their global physical health (SF-12) (p < 0.001). However, patients with any degree of mental disability had a significant improvement in their mental health post-operatively (p < 0.001). Despite a similar improvement in their disease-specific scores and improvement in their mental health, patients with mental disability were significantly more likely to be dissatisfied with their TKR at one year (p = 0.001). Patients with poor mental health do benefit from improvements in their mental health and knee function after TKR, but also have a higher rate of dissatisfaction.

Ambient particulate air pollution and acute lower respiratory infections: a systematic review and implications for estimating the global burden of disease

Acute lower respiratory infections (ALRI) account for nearly one fifth of mortality in young children worldwide and have been associated with exposures to indoor and outdoor sources of combustion-derived air pollution. A systematic review was conducted to identify relevant articles on air pollution and ALRI in children. Using a Bayesian approach to meta-analysis, a summary estimate of 1.12 (1.03, 1.30) increased risk in ALRI occurrence per 10 μg/m³ increase in annual average PM_2.5 concentration was derived from the longer-term (subchronic and chronic) effects studies. This analysis strengthens the evidence for a causal relationship between exposure to PM_2.5 and the occurrence of ALRI and provides a basis for estimating the global attributable burden of mortality due to ALRI that is not influenced by the wide variation in regional case fatality rates. Most studies, however, have been conducted in settings with relatively low levels of PM_2.5. Extrapolating their results to other, more polluted, regions will require a model that is informed by evidence from studies of the effects on ALRI of exposure to PM_2.5 from other combustion sources, such as secondhand smoke and household solid fuel use.

Tracking national and regional spatial-temporal mortality risk associated with NO2 concentrations in Canada: a Bayesian hierarchical two-level model

The association between daily variations in urban air quality and mortality has been well documented using time series statistical methods. This approach assumes a constant association over time. We develop a space-time dynamic model that relaxes this assumption, thus more directly examining the hypothesis that improvements in air quality translate into improvements in public health. We postulate a Bayesian hierarchical two-level model to estimate annual mortality risks at regional and national levels and to track both risk and heterogeneity of risk within and between regions over time. We illustrate our methods using daily nitrogen dioxide concentrations (NO2) and nonaccidental mortality data collected for 1984-2004 in 24 Canadian cities. Estimates of risk and heterogeneity are compared by cause of mortality (cardio-pulmonary [CP] versus non-CP) and season, respectively. Over the entire period, the NO2 risk for CP mortality was slightly lower but with a narrower credible interval than that for non-CP mortality, mainly due to an unusually low risk for a single year (1998). Warm season NO2 risk was higher than cold season risk for both CP and non-CP mortality. For 21 years overall there were no significant differences detected among the four regional NO2 risks. We found overall that there was no strong evidence for time trends in NO2 risk at national or regional levels. However, an increasing linear time trend in the annual between-region heterogeneities was detected, which suggests the differences in risk among the four regions are getting larger, and further studies are necessary to understand the increasing heterogeneity.

Multicenter prospective trial of hypofractionated radiation treatment, toceranib, and prednisone for measurable canine mast cell tumors

BACKGROUND

Mast cell tumors (MCT) are common cutaneous tumors in dogs and when not amenable to surgical excision can present a therapeutic challenge. New treatment protocols for unresectable MCT are needed.

HYPOTHESIS

The combination of toceranib, prednisone, and hypofractionated radiation treatment (RT) will be well tolerated and efficacious.

ANIMALS

Seventeen client-owned dogs with measurable MCT amenable to RT.

METHODS

Prospective clinical trial. All dogs received prednisone, omeprazole, diphenhydramine, and toceranib. Toceranib was administered for 1 week before initiating RT, consisting of 24 Gy delivered in 3 or 4 fractions.

RESULTS

On an intent-to-treat basis, the overall response rate was 76.4%, with 58.8% of dogs achieving a complete response and 17.6% a partial response. The median time to best response was 32 days, and the median progression-free interval was 316 days. The overall median survival time was not reached with a median follow-up of 374 days. The most common toxicoses were gastrointestinal and hepatic.

CONCLUSIONS AND CLINICAL IMPORTANCE

The combination of hypofractionated RT, toceranib, and prednisone was tolerated and efficacious in the majority of dogs. Response rates and durations were higher than those reported for toceranib as a single-agent treatment for MCT. This combination is a viable treatment option for unresectable MCT.

Enzymatic hydrolysis of cellulose dissolved in N-methyl morpholine oxide/water solutions

In situ hydrolysis of cellulose (dissolving pulp) in N-methyl morpholine oxide (NMMO) solutions by commercially available Accellerase1000 is carried out. The yield of reducing sugars is followed as a function of time at three different temperatures and four different enzyme loadings to study the effect of system parameters on enzymatic hydrolysis. Initial results show that rates of hydrolysis of cellulose and yields of reducing sugars in the presence of NMMO-water is superior initially (ratio of initial reaction rates approximately 4) and comparable to that of regenerated cellulose (for times greater than 5h) when suspended in aqueous solutions. The usage of Accellerase1000 results predominantly in the formation of glucose with minimal amounts of cellobiose. This study proves the ability of cellulases to remain active in NMMO to carry out an in situ saccharification of cellulose thus eliminating the need to recover regenerated cellulose. Thus this work will form the basis for developing a continuous process for conversion of biomass to hydrogen, ethanol and other hydrocarbons.

The effects of thiamine inhibition on ruminal fermentation: a preliminary study

Inhibition of methanogenesis in ruminal cultures was attempted by hindering thiamine availability through its degradation by 'polyphenols' and competition for active sites on enzymes and transporters using thiamine structural analogs. Effects on fermentation were small and not consistently reversed by adding thiamine. Lack of major effects of the compounds evaluated could be due to intracellular synthesis of thiamine covering most requirements.

Spatial analysis of air pollution and childhood asthma in Hamilton, Canada: comparing exposure methods in sensitive subgroups

BACKGROUND

Variations in air pollution exposure within a community may be associated with asthma prevalence. However, studies conducted to date have produced inconsistent results, possibly due to errors in measurement of the exposures.

METHODS

A standardized asthma survey was administered to children in grades one and eight in Hamilton, Canada, in 1994-95 (N approximately 1467). Exposure to air pollution was estimated in four ways: (1) distance from roadways; (2) interpolated surfaces for ozone, sulfur dioxide, particulate matter and nitrous oxides from seven to nine governmental monitoring stations; (3) a kriged nitrogen dioxide (NO2) surface based on a network of 100 passive NO2 monitors; and (4) a land use regression (LUR) model derived from the same monitoring network. Logistic regressions were used to test associations between asthma and air pollution, controlling for variables including neighbourhood income, dwelling value, state of housing, a deprivation index and smoking.

RESULTS

There were no significant associations between any of the exposure estimates and asthma in the whole population, but large effects were detected the subgroup of children without hayfever (predominately in girls). The most robust effects were observed for the association of asthma without hayfever and NO2LUR OR = 1.86 (95%CI, 1.59-2.16) in all girls and OR = 2.98 (95%CI, 0.98-9.06) for older girls, over an interquartile range increase and controlling for confounders.

CONCLUSION

Our findings indicate that traffic-related pollutants, such as NO2, are associated with asthma without overt evidence of other atopic disorders among female children living in a medium-sized Canadian city. The effects were sensitive to the method of exposure estimation. More refined exposure models produced the most robust associations.

HPV genotypes in women with squamous intraepithelial lesions and normal cervixes participating in a community-based microbicide study in Pretoria, South Africa

BACKGROUND

Little is known regarding the human papillomaviruses (HPV) genotypes prevalent in women in South Africa, a country with a high incidence of cervical cancer.

OBJECTIVE

To determine the prevalence and HPV genotypes in women with squamous abnormalities and normal cervixes participating in a community-based microbicide study.

STUDY DESIGN

A total of 159 cervical specimens, including 56 specimens from women with abnormal cytology (cases) and 103 randomly selected specimens from women with normal cytology (controls), were collected. HPV was detected by consensus PCR primers and HPV genotypes were determined by Roche Linear Array HPV genotyping assay.

RESULTS

HPV genotypes were found in 91% of cases and 40% of controls (p<0.005). High-risk HPV was detected in all high-grade squamous intraepithelial lesions (HSILs), 69% of low-grade squamous intraepithelial lesions (LSILs), 57% of atypical squamous cells of undetermined significance (ASCUS), and 86% of ASCUS in which HSIL could not be excluded (ASCUS-H), and 73% of HPV positive controls. HPV-35 was the predominant genotype in HSILs; HPV-18 in ASCUS; HPV-58 in ASCUS-H and HPV-16 in LSILs and controls.

CONCLUSION

High-risk HPV prevalence was high in both cases and controls. HPV genotype distribution in HSILs was different from that reported worldwide and from other studies in South Africa.

Acute effects of ambient particulate matter on mortality in Europe and North America: results from the APHENA study

BACKGROUND

THE APHENA (AIR POLLUTION AND HEALTH: A Combined European and North American Approach) study is a collaborative analysis of multicity time-series data on the effect of air pollution on population health, bringing together data from the European APHEA (Air Pollution and Health: A European Approach) and U.S. NMMAPS (National Morbidity, Mortality and Air Pollution Study) projects, along with Canadian data.

OBJECTIVES

The main objective of APHENA was to assess the coherence of the findings of the multicity studies carried out in Europe and North America, when analyzed with a common protocol, and to explore sources of possible heterogeneity. We present APHENA results on the effects of particulate matter (PM) < or = 10 microm in aerodynamic diameter (PM(10)) on the daily number of deaths for all ages and for those < 75 and > or = 75 years of age. We explored the impact of potential environmental and socioeconomic factors that may modify this association.

METHODS

In the first stage of a two-stage analysis, we used Poisson regression models, with natural and penalized splines, to adjust for seasonality, with various degrees of freedom. In the second stage, we used meta-regression approaches to combine time-series results across cites and to assess effect modification by selected ecologic covariates.

RESULTS

Air pollution risk estimates were relatively robust to different modeling approaches. Risk estimates from Europe and United States were similar, but those from Canada were substantially higher. The combined effect of PM(10) on all-cause mortality across all ages for cities with daily air pollution data ranged from 0.2% to 0.6% for a 10-microg/m(3) increase in ambient PM(10) concentration. Effect modification by other pollutants and climatic variables differed in Europe and the United States. In both of these regions, a higher proportion of older people and higher unemployment were associated with increased air pollution risk.

CONCLUSIONS

Estimates of the increased mortality associated with PM air pollution based on the APHENA study were generally comparable with results of previous reports. Overall, risk estimates were similar in Europe and in the United States but higher in Canada. However, PM(10) effect modification patterns were somewhat different in Europe and the United States.

Increases in microbial nitrogen production and efficiency in vitro with three inhibitors of ruminal methanogenesis

It was hypothesized that the addition of crotonic acid or 3-butenoic acid would relieve constraints in digestibility observed when methane formation is inhibited by lumazine, propynoic acid, or ethyl 2-butynoate. In six incubations, one of the three methanogenesis inhibitors, at three different concentrations, was combined with either crotonic acid or 3-butenoic acid at two different concentrations. A mixture of buffer and ruminal fluid (4:1) was incubated with grass hay in Erlenmeyer flasks for 72 h. Initial concentrations were 0, 0.6, and 1.2 mmol/L for lumazine; 0, 2, and 4 mmol/L for propynoic acid; and 0, 4, and 8 mmol/L for ethyl 2-butynoate. 15Nitrogen (N) incorporation was used as a microbial marker. All three methanogenesis inhibitors decreased proteolysis. Propynoic acid and ethyl 2-butynoate at 8 mmol/L also decreased the digestibility of organic matter and neutral detergent fibre. However, all three inhibitors of methanogenesis increased the production of microbial N through an improvement of synthetic efficiency. Crotonic acid and 3-butenoic acid were generally ineffective in compensating digestibility decreases caused by the inhibitors of methanogenesis. It is of interest to elucidate the mechanisms by which these compounds increased the efficiency of microbial N production. Lumazine and the addition of low levels of ethyl 2-butynoate could potentially benefit animal production by lowering methane emissions, decreasing ruminal proteolysis, and increasing microbial N production without affecting organic matter digestibility.

Effects of butyrate precursors on electron relocation when methanogenesis is inhibited in ruminal mixed cultures

AIMS

Inhibition of ruminal methanogenesis often causes accumulation of H(2), formate and ethanol, which are not energy substrates for ruminants. It was hypothesized that the addition of butyrate precursors would avoid the formation of these products and relocate electrons into butyrate.

METHODS AND RESULTS

In four ruminal 24-h incubations, two inhibitors of methanogenesis, each at three different initial concentrations (0, 2 or 4 mmol l(-1) for propynoic acid, and 0, 4 or 8 mmol l(-1) for ethyl 2-butynoate), were combined with two butyrate precursors at two different initial concentrations (0 or 4 mmol l(-1) for crotonic acid or 3-butenoic acid). Ground lucerne hay was the substrate. Propynoic acid at 4 mmol l(-1) decreased CH(4) formation by more than two-thirds. Ethyl 2-butynoate at 8 mmol l(-1) suppressed methanogenesis by more than 90%. Butyrate precursors generally did not decrease the accumulation of H(2) and formate or ethanol production.

CONCLUSIONS

Butyrate precursors were ineffective as electron acceptors because they were not completely converted to butyrate and were also metabolized through other pathways.

SIGNIFICANCE AND IMPACT OF THE STUDY

Effectiveness of butyrate precursors may be improved by adding them to the fermentation continuously or by enhancing the kinetics of their conversion into butyrate.

Testing the harvesting hypothesis by time-domain regression analysis. I: baseline analysis

Although the association between air pollution and daily mortality is well established, the mechanisms by which air pollution results in excess mortality are not yet well understood. In particular, there exists debate over whether air pollution has a direct effect on mortality in the general population or simply shortens the life span of frail individuals, a hypothesis referred to as "harvesting." The goal of this investigation is to test the harvesting hypothesis using the time-domain regression method of Dominici et al. (2003a). We conducted simulations based on a two-compartment model that divides the population into a larger group of healthy individuals and a frail subpopulation. Death from air pollution is assumed to take place in two steps, by first moving from healthy population to the frail pool, then death with probability related to the level of air pollution. Using time-domain analysis, we seek to identify data patterns that would be characteristic of harvesting under different scenarios. For a pure harvesting model, time-domain analysis indicates that mortality is associated with a short-term air pollution episode of less than 2 d if the mean residency time in the frail pool is short. If both entrants and deaths depend on the level of air pollution and the rates of entry to and exit from the frail pool are about the same, the log relative risk estimates are essentially unchanged at all time scales. If pollution affects mortality in the frail pool more than entrants, larger effects will occur at shorter time scales.

Testing the harvesting hypothesis by time-domain regression analysis. II: covariate effects

This article extends the previous work of Fung et al. (2004) investigating the ability of the time-scale log-linear regression model, proposed by Dominici et al. (2003), to detect mortality displacement (sometimes known as harvesting) in time-series data relating air pollution to excess mortality. We conducted a simulation study based on two different compartment models of the death process: pure frailty model and mixed frailty model. We assume that nonaccidental death only affects frail population in a pure frailty model and affects both frail people and other individuals in the mixed frailty model. With a pure frailty model and a moderate-size pollution effect, we identified a characteristic mortality displacement pattern in the different time-scale coefficients of log relative risk. However, once a covariate like temperature was introduced into the model, such a mortality displacement pattern disappeared. Furthermore, a false mortality displacement effect was present in the incorrectly specified model, when temperature was not taken into account. We believe that time-scale regression has limited value for detecting mortality displacement in time-series data.

Comparison of time series and case-crossover analyses of air pollution and hospital admission data

BACKGROUND

Time series analysis is the most commonly used technique for assessing the association between counts of health events over time and exposure to ambient air pollution. Recently, case-crossover analysis has been proposed as an alternative analytical approach. While each technique has its own advantages and disadvantages, there remains considerable uncertainty as to which statistical methodology is preferable for evaluating data of this type.

METHODS

The objective of this paper is to evaluate the performance of different variations of these two procedures using computer simulation. Hospital admission data were generated under realistic models with known parameters permitting estimates based on time series and case-crossover analyses to be compared with these known values.

RESULTS

While accurate estimates can be achieved with both methods, both methods require some decisions to be made by the researcher during the course of the analysis. With time series analysis, it is necessary to choose the time span in the LOESS smoothing process, or degrees of freedom when using natural cubic splines. For case-crossover studies using either uni- or bi-directional control selection strategies, the choice of time intervals needs to be made.

CONCLUSIONS

We prefer the times series approach because the best estimates of risk that can be obtained with time series analysis are more precise than the best estimates based on case-crossover analysis.

Attempts to inhibit ruminal methanogenesis by blocking pyruvate oxidative decarboxylation

The inhibition of pyruvate oxidative decarboxylation as a means of decreasing ruminal methanogenesis in vitro was studied. In the first experiment, the addition of adenosine and adenine (with and without ribose) to ruminal batch cultures did not decrease methanogenesis. In the second experiment, the addition of oxythiamin decreased methanogenesis by 23%. In the third experiment, three pyruvate derivatives did not inhibit methanogenesis, although hydroxypyruvate improved organic matter fermentation from 57.8% to 64.2%. The additives did not seem to inhibit pyruvate oxidative decarboxylation.Key words: methane, inhibition, rumen, pyruvate decarboxylation, thiamin.

Predictors of herbicide exposure in farm applicators

OBJECTIVES

Most epidemiological studies of pesticides have used self-reports rather than quantitative measurements to assess exposures. The purpose of this study was to identify factors likely to affect exposure under actual field conditions and to measure the sensitivity and specificity of self-reported indications of exposure against urinary measures of herbicide exposure.

METHODS

A sub-set of the participants in a retrospective cohort study of Ontario farm families volunteered for a pesticide exposure assessment study. Immediately prior, and subsequent to, handling the phenoxy-herbicides 2,4-dichlorophenoxyacetic acid (2,4-D) or 4-chloro-2-methylphenoxyacetic acid (MCPA) for the first time during the season, 126 pesticide applicators provided pre-exposure spot urine samples and a subsequent consecutive 24-h urine sample. At the same time, they completed a questionnaire on pesticide use and handling practices for the first day of pesticide application.

RESULTS

Assuming that the presence of 2,4-D in the urine was a measure of true exposure and that questionnaire indications of 2,4-D use were the exposure classification subject to error, then the questionnaire's prediction of exposure had a sensitivity of 56.7% and specificity of 86.4%. The comparable values for MCPA were sensitivity and specificity of 91.6% and 67.4%, respectively. In multivariate models, the variables pesticide formulation, protective clothing/gear, application equipment, handling practice, and personal hygiene practice were significant as predictors of urinary herbicide levels in the first 24 h after application (or spraying) had been initiated (adjusted R(2)=44% for MCPA and 39% for 2,4-D).

CONCLUSIONS

Although similar domains of factors were associated with exposure in both models, the specific factors identified and the signs of the coefficients were sufficiently different between the final models for each herbicide that additional investigations appear to be warranted to determine the sources of the differences and assess the validity of the models and their ability to be generalised.

Humeral osteonecrosis leading to the early detection of a bronchial carcinoma

The new Ionising Radiation (Medical Exposure) Regulations 2000 (IR (ME)ER) were implemented in January 2001. These regulations state that "the referrer must record in the patient's notes that a radiograph was taken and what it showed". As a result it is now incumbent upon the orthopaedic surgeon to document formally the findings of all requested radiographs. We present a case in which a left upper bronchial carcinoma was detected initially on a radiograph of the left shoulder. It highlights the importance of careful examination of the entire radiographic image and the documenting of the findings.

Effect of murine recombinant IL-2 on the course of lupus-like disease in (NZBxNZW) F1 female mice

The exacerbation of pre-existing autoimmune diseases is a potential toxic effect of immunoactive drugs. An increase in the incidence of autoimmune thyroiditis has been noted in patients treated with human recombinant interleukin-2 (rIL-2). In contrast, human rIL-2 tends to protect mice from autoimmunity. As the effects of murine rIL-2 on autoimmunity have not been reported in mice, lupus-prone female (NZBxNZW) F1 mice were treated with 20,000 IU murine rIL-2 intraperitoneally, twice weekly for 13 weeks, beginning at 15 weeks of age. No evidence of an exacerbating effect of murine IL-2 on the lupus disease of (NZBxNZW) F1 mice was observed as no change in the following parameters were seen, namely mean survival time, mean body weight, anti-DNA and antinuclear antibody production. These results show that: 1) like human rIL-2, murine rIL-2 does not exacerbate autoimmunity in mice; 2) the biological effects of human as well as murine rIL-2 in mice differ from those seen with human rIL-2 in man. These latter findings suggest that the selection of the relevant animal species for immunotoxicity studies with recombinant cytokines and derivatives may be less straightforward than previously thought.

The spatial association between community air pollution and mortality: a new method of analyzing correlated geographic cohort data

We present a new statistical model for linking spatial variation in ambient air pollution to mortality. The model incorporates risk factors measured at the individual level, such as smoking, and at the spatial level, such as air pollution. We demonstrate that the spatial autocorrelation in community mortality rates, an indication of not fully characterizing potentially confounding risk factors to the air pollution-mortality association, can be accounted for through the inclusion of location in the model assessing the effects of air pollution on mortality. Our methods are illustrated with an analysis of the American Cancer Society cohort to determine whether all cause mortality is associated with concentrations of sulfate particles. The relative risk associated with a 4.2 microg/m(3) interquartile range of sulfate distribution for all causes of death was 1.051 (95% confidence interval 1.036-1.066) based on the Cox proportional hazards survival model, assuming subjects were statistically independent. Inclusion of community-based random effects yielded a relative risk of 1.055 (1.033, 1.077), which represented a doubling in the residual variance compared to that estimated by the Cox model. Residuals from the random-effects model displayed strong evidence of spatial autocorrelation (p = 0.0052). Further inclusion of a location surface reduced the sulfate relative risk and the evidence for autocorrelation as the complexity of the location surface increased, with a range in relative risks of 1.055-1.035. We conclude that these data display both extravariation and spatial autocorrelation, characteristics not captured by the Cox survival model. Failure to account for extravariation and spatial autocorrelation can lead to an understatement of the uncertainty of the air pollution association with mortality.

The spatial association between community air pollution and mortality: a new method of analyzing correlated geographic cohort data

We present a new statistical model for linking spatial variation in ambient air pollution to mortality. The model incorporates risk factors measured at the individual level, such as smoking, and at the spatial level, such as air pollution. We demonstrate that the spatial autocorrelation in community mortality rates, an indication of not fully characterizing potentially confounding risk factors to the air pollution-mortality association, can be accounted for through the inclusion of location in the model assessing the effects of air pollution on mortality. Our methods are illustrated with an analysis of the American Cancer Society cohort to determine whether all cause mortality is associated with concentrations of sulfate particles. The relative risk associated with a 4.2 microg/m(3) interquartile range of sulfate distribution for all causes of death was 1.051 (95% confidence interval 1.036-1.066) based on the Cox proportional hazards survival model, assuming subjects were statistically independent. Inclusion of community-based random effects yielded a relative risk of 1.055 (1.033, 1.077), which represented a doubling in the residual variance compared to that estimated by the Cox model. Residuals from the random-effects model displayed strong evidence of spatial autocorrelation (p = 0.0052). Further inclusion of a location surface reduced the sulfate relative risk and the evidence for autocorrelation as the complexity of the location surface increased, with a range in relative risks of 1.055-1.035. We conclude that these data display both extravariation and spatial autocorrelation, characteristics not captured by the Cox survival model. Failure to account for extravariation and spatial autocorrelation can lead to an understatement of the uncertainty of the air pollution association with mortality.

Oral 9-cis retinoic acid (Alitretinoin) in the treatment of myelodysplastic syndromes: results from a pilot study

A multicenter phase II study was initiated to investigate the efficacy, toxicity and tolerability of an oral regimen of 9-cis retinoic acid (9CRA) as a differentiation-inducing agent stimulating both retinoic acid receptor (RAR) and retinoic X receptor (RXR). Thirty patients with myelodysplastic syndromes (MDS) were enrolled into the study. The MDS subtypes were distributed as follows: 14 refractory anaemia (RA), four refractory anaemia with ringed sideroblasts (RARS), and 12 refractory anaemia with excess blasts (RAEB). The age ranged from 40 to 81 years (median 70). None of these had previously received treatment for MDS other than supportive therapy. 9CRA (Alitretinoin capsules, kindly provided by Allergan-Ligand Retinoid Therapeutics) was given daily at 60 mg/m2 p.o. for 1 week, followed by an intra-patient escalation to 100 mg/m2 during the second week, up to a maximum of 140 mg/m2. The planned treatment duration was 48 weeks. Twenty-five were available for assessment. One patient (4%) with RA achieved complete hematological remission. Four (16%), two with RA, two with RAEB, had minor responses resulting in decreased transfusion requirements or increased neutrophils. Thus, the overall response rate was 20% in evaluable patients with MDS and 17% in the study group on an intention-to-treat basis. The most frequent side-effects included headache (77%), dry skin (57%), arthralgias (30%), and rash (23%). In conclusion, although modest responses were noted in this study, the treatment tolerability was suboptimal. It is conceivable that a lower dosage schedule may be efficacious and better tolerated so enabling prolonged exposure which may be required to induce a differentiation effect.