Mapping bark bacteria: initial insights of stemflow-induced changes in bark surface phyla.

IMPORTANCE: Compared with the phyllosphere, bacteria inhabiting bark surfaces are inadequately understood. Based on a preliminary pilot study, our work suggests that microbial populations vary across tree bark surfaces and may differ in relation to surrounding land use. Initial results suggest that stemflow, the water that flows along the bark surface, actively moves bacterial communities across a tree. These preliminary findings underscore the need for further study of niche microbial populations to determine whether there are connections between the biodiversity of microbiomes inhabiting corticular surfaces, land use, and hydrology.

Tropical seabirds sample broadscale patterns of marine contaminants.

Contaminants in the marine environment are widespread, but ship-based sampling routines are much narrower. We evaluated the utility of seabirds, highly-mobile marine predators, as broad samplers of contaminants throughout three tropical ocean regions. Our aim was to fill a knowledge gap in the distributions of, and processes that contribute to, tropical marine contaminants; and explore how species-specific foraging ecologies could inform or bias our understanding of contaminant distributions. Mercury and persistent organic pollutant (POPs) concentrations were measured in adults of five seabird species from four colonies in the central Pacific (Laysan and Tern Islands, Hawaii; Palmyra Atoll) and the eastern Caribbean (Barbuda). Blood-based total mercury (THg) and 89 POPs were measured in two seabird families: surface-foraging frigatebirds (Fregata spp.) and plunge-diving boobies (Sula spp.). Overall, largescale contaminant differences between colonies were more informative of contaminant distributions than inter-specific foraging ecology. Model selection results indicated that proximity to human populations was the best predictor of THg and POPs. Regional differences in contaminants were distinct: Barbudan Magnificent Frigatebirds had more compounds (n=52/89 POP detected) and higher concentrations (geometric mean THg=0.97µgg-1; mean ΣPOP53=26.6ngmL-1) than the remote colonies (34-42/89 POP detected; range of THg geometric means=0.33-0.93µgg-1; range of mean ΣPOP53:7.3-17.0ngmL-1) and had the most recently-synthesized POPs. Moderate differences in foraging ecologies were somewhat informative of inter-specific differences in contaminant types and concentrations between nearshore and offshore foragers. Across species, contaminant concentrations were higher in frigatebirds (THg=0.87µgg-1; ΣPOP53=17.5ngmL-1) compared to boobies (THg=0.48µgg-1; ΣPOP53=9.8). Ocean currents and contaminants' physiochemical properties provided additional insight into the scales of spatial and temporal contaminant exposure. Seabirds are excellent, broad samplers with which we can understand contaminant distributions in the marine environment. This is especially important for tropical remote regions that are under-sampled.

Combined active and passive heat exposure induced heat acclimation in a soccer referee before 2014 FIFA World Cup.

INTRODUCTION: The 2014 FIFA World Cup was held in Brazil, where the climatic conditions presented a significant thermoregulatory and perceptual challenge to those unfamiliar with the heat and humidity. CASE PRESENTATION: This case report documents the adaptation induced by a novel mixed methods (isothermic and passive) heat acclimation (HA) regime for a northern European professional soccer match official prior to the tournament. The intervention involved 13 HA sessions over an 18 day period comprising five isothermic HA sessions whereby intermittent running was used to target and maintain tympanic temperature (Tytemp) at 38 °C for 90 min, and seven passive HA sessions of 48 °C water bathing for 30 min. The athlete performed a heat stress test (HST) (35 min running at four incremental intensities in 30 °C) and a repeated high-intensity running test (as many 30 s self-paced efforts as possible, to a maximum of 20, with 30 s passive recovery) before and after the intervention. The mixed methods HA regime increased plasma volume (+7.1 %), and sweat loss (+0.9 L h(-1)), reduced exercising Tytemp (-0.6 °C), and mean body temperature (-0.5 °C). High-intensity running performance improved after HA (+29 %), as did the perception of thermal comfort during exercise (-0.3 units). CONCLUSION: This data evidences the effectiveness of a practical, mixed methods HA strategy, remotely implemented around training and competition, at inducing the heat acclimation phenotype in a high-level soccer match official.

Siglec-F antibody administration to mice selectively reduces blood and tissue eosinophils.

BACKGROUND: Sialic acid-binding immunoglobulin-like lectins (Siglecs) are a family of receptors that bind sialic acid and mostly contain immunoreceptor tyrosine-based inhibitory motifs, suggesting that these molecules possess inhibitory functions. We have recently identified Siglec-8 as an eosinophil-prominent Siglec, and cross-linking of Siglec-8 on human eosinophils induces apoptosis. In this article, we address the in vivo consequences of Siglec engagement. We and others have identified mouse Siglec-F as the closest functional paralog of human Siglec-8, based on shared ligand-binding and expression pattern. We therefore hypothesized that Siglec-F engagement would affect levels and viability of eosinophils in vivo. METHODS: Wild type and hypereosinophilic mice were administered Siglec-F antibody and levels of eosinophils in peripheral blood and tissue were measured. Eosinophil apoptosis (in vivo and in vitro) was determined by binding of Annexin-V. RESULTS: Studies in IL-5 transgenic mice, displaying hypereosinophilia, show that administration of a single dose of Siglec-F antibody results in rapid reductions in quantum of eosinophils in the blood. This decrease was accompanied by reductions in tissue eosinophils. Quantum of eosinophils in blood was decreased using two separate antibodies, as well as in other mouse models (wild type mice and in a mouse model of chronic eosinophilic leukemia). Mechanistic studies demonstrated that Siglec-F antibody administration induced apoptosis of eosinophils in vivo and in vitro. CONCLUSION: These data demonstrate that activation of innate immune receptors, like Siglec-F, can significantly reduce mouse eosinophil viability. As such, targeting Siglec-8/F may be a therapeutic approach for eosinophilic disorders.

Evaluation of the implementation of a local treatment guideline in secondary prevention post-myocardial infarction.

OBJECTIVE: To validate and implement an audit tool to assess quality and appropriateness of prescribing. To compare inpatient prescribing of secondary prevention in post myocardial infarction patients before and after introduction of a local treatment guideline. METHOD: Descriptive, non-experimental retrospective case note review comparing patients treated before and after the implementation of a clinical guideline. MAIN OUTCOME: Comparison of quality of prescribing in two patient groups. RESULTS: Analysis of Group 1 patients showed that 41% required treatment with an angiotensin converting enzyme inhibitor (ACE-I), and 23% of those did not receive treatment, 20% of patients on ACE-I received sub-therapeutic doses. Seventy-two per cent of patients required treatment with a statin and 22% of those did not receive a statin. Comparison of the treatment of Group 2 showed that, of 53 patients (50% of Group 2) requiring an ACE-I, 100% received it, although 15% received sub-therapeutic doses. Of 69 patients (64% of Group 2) requiring treatment with a statin 96% were prescribed a statin. Improvements in prescribing of beta-Blockers, ACE-I and statins were statistically significant. CONCLUSIONS: Prescribing improved significantly for beta-Blockers, ACE-I and statins after guideline introduction with anticipated benefits to patient outcomes.

Identification of the pharmaceutical care issues of rheumatoid arthritis patients in secondary care.

OBJECTIVE: To explore the perceptions of multidisciplinary health care professionals (HCPs) and patients of the pharmaceutical care issues (PCIs) relating to rheumatoid arthritis (RA). DESIGN: Qualitative study using semi-structured one to one interviews and focus groups to explore patient perceptions. Interviews and focus groups were taped and transcribed verbatim, then described and coded for meaning to produce 'in-vivo' codes, which were then grouped to form themes. Nominal group methodology was used to generate and rank a list of HCP perceptions of the key PCIs of RA patients. The PCIs were ranked according to clinical importance and order of occurrence from admission as perceived by the HCP group. SETTING: Rheumatology ward and outpatient clinic in a teaching hospital. MAIN OUTCOME MEASURES: Generation and ranking of PCIs, generation of themes from patient interviews. RESULTS: Optimisation of pain control was identified by the nominal group as being the primary aim for patients on admission and was also the most commonly described symptom by patients. Two PCIs not predicted by the HCPs' nominal group was the frequency of infections and the associated discharge and patients described experiencing 'over-education' by HCPs, which could lead to anxiety. Complementary medicine in conjunction with traditional therapy was raised as a significant health benefit by patients. CONCLUSION: Many patients' views mirrored the PCIs identified by HCPs, but some were not anticipated; the value of patient interviews to ensure appropriate service development was demonstrated. Several PCIs emerged for future incorporation by the multi-disciplinary team into standardised models of pharmaceutical care for use in secondary care and at the secondary/primary care interface for improvement of seamless care. There is a need to target educational interventions and to identify those who will benefit from advice on complementary medicine. Further work is required to develop a tool to identify the educational needs of RA patients and targeting of the information provided. This will help ensure the delivery of pharmaceutical care is designed to match the needs of individual patients.

The pharmaceutical care of patients with hypertension: an examination of service models in primary care in the US.

BACKGROUND: In the UK, the delivery of health care in cardiovascular disease is guided by national service frameworks', which are a source of standards of practice and evidence that help to define and aid the implementation of service models capable of responding to public health goals. The revised British Hypertension Society guidelines reflect a lower target blood pressure consistent with those recommended in the US and by the WHO. The lowering of the target for the control of blood pressure has increased the estimated proportion of treated patients with inadequate control in the UK from 37% to 72%. OBJECTIVE: To identify the requirements for the provision of a pharmacy service that supports hypertension monitoring, and to gain insights into how such a service might be delivered as part of a wider provision of pharmaceutical care in the UK. METHOD: Two pharmacists followed a structured programme of observation involving three centres in the United States (Minnesota, Colorado and Iowa). Twelve clinical settings were observed, and the pharmacists who provided the services were also the subjects of documented interviews. The settings offered different models of pharmaceutical care from which issues relevant to the international development of such services were identified. FINDINGS: Differences noted between the service models observed included; physical environment of the community pharmacy, the use and type of documentation, methods of blood pressure measurement, extent of monitoring and follow-up, inter-professional communication and service orientation in terms of the provision of comprehensive pharmaceutical care to patients or specific disease management. CONCLUSION: If clearly defined operational models of pharmaceutical care practice in the primary care setting are to form part of a national public health strategy in the UK, they must also be capable of responding to local opportunities and patients' needs. Future development of models and services must be patient-centred and more widely informed by the range of practice experience gained elsewhere.

Acquisition and alteration of adhesion molecules during cultured human mast cell differentiation.

BACKGROUND: Mature human mast cells express several types of adhesion molecules on their surface. Interactions between extracellular matrix (ECM) and adhesion molecules may be important for the migration and localization of mast cells and their precursors in tissues. Little is known about the regulation of adhesion molecules on mast cells during their differentiation. OBJECTIVES: To clarify the evolution of adhesion phenotype and function, we examined the expression of adhesion molecules during cultured human mast cell (CHMC) differentiation and tested adhesion of mature CHMCs to various ECM proteins. METHODS: CHMCs were obtained by culturing human cord blood-derived CD34(+) cells in the presence of stem cell factor and IL-6. Indirect immunofluorescence and flow cytometry was used to study cell surface expression of adhesion molecules and other markers. Mature CHMCs were tested for adhesion molecule function with immobilized matrix proteins. RESULTS: At 1 week of culture, cells expressed CD11a, CD18, CD29, CD49d, and CD49e. At 14 weeks of culture, more mature CHMCs expressed CD11b, CD11c, CD29, CD49b, CD49c, CD49d, CD49e, CD51, CD61, and CD54 and weakly expressed CD18 and CD11a. CD11c, CD51, and CD61 appeared de novo by 4 weeks of culture, whereas CD49b and CD49c appeared by 8 weeks. CD29 decreased at 4 weeks but returned to the identical levels of 1-week-old cells by 8 weeks. Compared with levels at week 1, the levels of CD11a, CD18, CD49d, and CD49e at 4 weeks and beyond decreased during culture. Expression of CD49a, CD49f, and alphad integrin was never detectable during CHMC differentiation. Fourteen-week-old CHMCs significantly adhered to the leucine-aspartic acid-valine-containing connecting segment 1 fragment of fibronectin, the 120-kd argine-glycine-aspartic acid-containing fragment of fibronectin, vitronectin, and laminin through specific integrins. CONCLUSION: Expression of integrins and CD54 is differentially regulated during CHMC differentiation, and mature CHMCs can adhere to many ECM proteins. These changes may facilitate emigration from the bone marrow into the circulation and ultimately contribute to the tissue homing and localization pattern seen with mature mast cells.

Expression and function of P-selectin glycoprotein ligand 1 (CD162) on human basophils.

BACKGROUND: The endothelial cell adhesion molecule P-selectin may contribute to selective leukocyte migration in allergic diseases by binding to its ligand, P-selectin glycoprotein ligand 1 (PSGL-1), on eosinophils and other leukocytes. Although expression of PSGL-1 on basophils has been detected in leukocyte typing workshops, its function on basophils has not been explored. OBJECTIVE: We sought to characterize the expression and function of PSGL-1 on human basophils and a basophil-like cell line (KU812) and to compare these characteristics with those for PSGL-1 on eosinophils and neutrophils. METHODS: Basophils, eosinophils, and neutrophils were enriched from peripheral blood by using density gradient centrifugation and immunomagnetic negative selection. KU812 cells were cultured by using standard techniques. Indirect immunofluorescence and flow cytometry were used to determine surface PSGL-1 expression under various conditions, and Western blotting was used to analyze the molecular forms of PSGL-1 on each cell type. Static adhesion assays were performed by using immobilized recombinant P-selectin and relevant blocking antibodies. Histamine release assays were done by using adherent and nonadherent basophils to determine whether adhesion by means of PSGL-1 altered basophil releasability. RESULTS: The expression of PSGL-1 on basophils was similar to that on neutrophils but was approximately 30% less bright than levels on eosinophils. Levels on basophils were 10-fold higher than on KU812 cells. Basophil activation by means of IgE cross-linking resulted in reductions in surface expression of PSGL-1 and L-selectin, as well as increased CD11b expression. Western blot analysis of PSGL-1 revealed that the molecular weights of the bands for neutrophils and basophils were similar, whereas those for eosinophils were of greater molecular weights. Static adhesion assays demonstrated that basophils bound well to P-selectin, whereas KU812 cells bound poorly. Adhesion of basophils to P-selectin was completely blocked by antibodies to either P-selectin or PSGL-1. Finally, adhesion to P-selectin did not alter the magnitude or kinetics of anti-IgE-induced histamine release. CONCLUSION: Expression of PSGL-1 on basophils is more similar to that on neutrophils than that on eosinophils. KU812 cells express much lower levels of this molecule but, like basophils and other cells, bind to P-selectin by means of PSGL-1. P-selectin expression at sites of allergic inflammation is likely to play an important role in human basophil recruitment, but adhesion by means of PSGL-1 does not alter IgE-dependent basophil histamine release.

CCR3-active chemokines promote rapid detachment of eosinophils from VCAM-1 in vitro.

Selective eosinophil recruitment is the result of orchestrated events involving cell adhesion molecules, chemokines, and their receptors. The mechanisms by which chemokines regulate eosinophil adhesion and migration via integrins are not fully understood. In our study, we examined the effect of CCR3-active chemokines on eosinophil adhesion to VCAM-1 and BSA under both static and flow conditions. When eotaxin-2 or other CCR3-active chemokines were added to adherent eosinophils, it induced rapid and sustained eosinophil detachment from VCAM-1 in a concentration-dependent manner. Adhesion was detectably reduced within 3 min and was further reduced at 10-60 min. Simultaneously, eotaxin-2 enhanced eosinophil adhesion to BSA. Preincubation of eosinophils with the CCR3-blocking mAb 7B11 completely prevented chemokine-induced changes in adhesion to VCAM-1 and BSA. Using a different protocol, pretreatment of eosinophils with chemokines for 0-30 min before their use in adhesion assays resulted in inhibition of VCAM-1 adhesion and enhancement of BSA adhesion. By flow cytometry, expression of alpha4 integrins and a beta1 integrin activation epitope on eosinophils was decreased by eotaxin-2. In a flow-based adhesion assay, eotaxin-2 reduced eosinophil accumulation and the strength of attachment to VCAM-1. These results show that eotaxin-2 rapidly reduced alpha4 integrin function while increasing beta2 integrin function. These findings suggest that chemokines facilitate migration of eosinophils by shifting usage away from beta1 integrins toward beta2 integrins.

Activation of human leukocytes reduces surface P-selectin glycoprotein ligand-1 (PSGL-1, CD162) and adhesion to P-selectin in vitro.

P-selectin glycoprotein ligand-1 (PSGL-1), the primary ligand for P-selectin, is constitutively expressed on the surface of circulating leukocytes. The objective of this study was to examine the effect of leukocyte activation on PSGL-1 expression and PSGL-1-mediated leukocyte adhesion to P-selectin. PSGL-1 expression was examined via indirect immunofluorescence and flow cytometry before and after leukocyte stimulation with platelet activating factor (PAF) and PMA. Human neutrophils, monocytes, and eosinophils were all demonstrated to have significant surface expression of PSGL-1 at baseline, which decreased within minutes of exposure to PAF or PMA. PSGL-1 was detected in the supernatants of PAF-activated neutrophils by immunoprecipitation. Along with the expression data, this suggests removal of PSGL-1 from the cell surface. Soluble PSGL-1 was also detected in human bronchoalveolar lavage fluids. Down-regulation of PSGL-1 was inhibited by EDTA. However, inhibitors of L-selectin shedding and other sheddase inhibitors did not affect PSGL-1 release, suggesting that PSGL-1 may be shed by an as yet unidentified sheddase or removed by some other mechanism. Functionally, PSGL-1 down-regulation was associated with decreased neutrophil adhesion to immobilized P-selectin under both static and flow conditions, with the most profound effects seen under flow conditions. Together, these data indicate that PSGL-1 can be removed from the surface of activated leukocytes, and that this decrease in PSGL-1 expression has profound effects on leukocyte binding to P-selectin, especially under conditions of flow.

Analysis of 1.9 Mb of contiguous sequence from chromosome 4 of Arabidopsis thaliana.

The plant Arabidopsis thaliana (Arabidopsis) has become an important model species for the study of many aspects of plant biology. The relatively small size of the nuclear genome and the availability of extensive physical maps of the five chromosomes provide a feasible basis for initiating sequencing of the five chromosomes. The YAC (yeast artificial chromosome)-based physical map of chromosome 4 was used to construct a sequence-ready map of cosmid and BAC (bacterial artificial chromosome) clones covering a 1.9-megabase (Mb) contiguous region, and the sequence of this region is reported here. Analysis of the sequence revealed an average gene density of one gene every 4.8 kilobases (kb), and 54% of the predicted genes had significant similarity to known genes. Other interesting features were found, such as the sequence of a disease-resistance gene locus, the distribution of retroelements, the frequent occurrence of clustered gene families, and the sequence of several classes of genes not previously encountered in plants.

Comparative study of the determination of bupivacaine in human plasma by gas chromatography-mass spectrometry and high-performance liquid chromatography.

A comparison was made between high-performance liquid chromatography (HPLC) and gas chromatography-mass spectrometry (GC-MS) as methods for determining bupivacaine in human plasma. Both methods utilized pentycaine as an internal standard, were found to be linear in the range 5-320 ng and had acceptable precision and accuracy. The precision for the HPLC method was better than that for the GC-MS method. The limits of detection of the HPLC and GC-MS methods were ca. 1.0 and 0.1 ng, respectively. Good agreement between the HPLC and GC-MS methods was obtained for the analysis of samples taken from a patient receiving bupivacaine topically. For most purposes the HPLC method would be slightly better. However, for samples containing interfering peaks GC-MS provides a higher degree of resolution from such interferants.

Evaluation of an antibiotic prescribing protocol for treatment of acute exacerbations of chronic obstructive airways disease in a hospital respiratory unit.

A prescribing protocol for infective exacerbations of chronic obstructive airways disease (COAD), specifying the use of oral amoxycillin 500 mg tid (or erythromycin 500 mg qid if allergic) as first line therapy, and oral ciprofloxacin 500 mg bd as second line treatment, was introduced in 1991. Every third sequential admission was screened for the year preceding (1990) and the year after (1991) the protocol was implemented. Only those patients with a discharge diagnosis of infective exacerbation of COAD, but without pneumonia, were included in the analysis. The two groups (1990 and 1991) were matched in terms of age, sex and pre-treatment given by their General Practitioner (GP), but differed with respect to severity score, with 1991 being more severe. The outcome measures showed that duration of hospital stay was comparable as was duration of treatment. Response to first line therapy was 68% and 67% for 1990 and 1991, respectively. Of those who had received antibiotics from their GP, 67% responded to first line therapy, while of those who had not received antibiotics from their GP 75% responded. Duration of therapy was shorter in first line responders (mean and 95% CI: 7.3 (6.3-8.3) days vs 12.7 (10.1-15.3) days). The mean cost per day antibiotic treatment was reduced by 54.6% (95% CI 52.3-56.9%) from 3.77 pounds to 1.71 pounds. In conclusion, the introduction of antibiotic prescribing guidelines for treatment of infective exacerbations of COAD showed no detrimental effect on outcome measures, but was associated with a significant reduction in the cost of antibiotic therapy.

Stress and the graduate psychology student.

One hundred seventy-one students from the Minnesota School of Professional Psychology completed the Psychology Student Stress Questionnaire (Cahir & Morris, 1991) and a data sheet that requested gender, year in school, income level, relationship status, age, number of children, and number of hours spent working per week. No significant differences were found between these life situation variables and the amount of stress that the student was reporting. Significant differences in student stress levels were found across the following variables: (1) number of children a student has and relationship status; (2) number of hours a student spends on the job; (3) student's relationship status with a significant other; and (4) student's gender. Implications for training programs and future research were discussed.

A pharmacokinetic study of high-dose metoclopramide suppositories.

The pharmacokinetics of high-dose rectal metoclopramide have been studied in nine patients after administration of 150-mg suppositories. The results have been compared to the pharmacokinetics of the drug in five patients who received the same dose of metoclopramide intravenously. Administration of a metoclopramide suppository achieved plasma drug concentrations that are associated with the effective treatment of cytotoxic drug-induced nausea and vomiting. In three patients who received the drug by both routes the systemic availability of the suppository appeared to be complete. High-dose metoclopramide suppositories are convenient and may be advantageous in the treatment of medical oncology out-patients.

Phenytoin dosage individualization--five methods compared in the elderly.

Five methods to predict phenytoin dosage have been compared in nine continuous care elderly patients. For each patient three steady-state plasma concentrations were obtained at three different doses. The data were used to estimate the 'optimum' dose for each patient by direct linear plot. The optimum dose for each patient was predicted from each plasma concentration using five dosage prediction methods based on the Michaelis-Menten equation using: (i) the population mean Vmax, (ii) the population mean KM, (iii) the linearized Bayesian method, (iv) the Rambeck nomogram, and (v) two plasma concentration-dose data pairs to estimate both Vmax and KM. The predictive precision was similar for each of methods (i-iv). Ninety-six out of 126 dosage predictions with the five methods were within 25 mg of the optimum dose. Methods (ii) and (iv) tended to overpredict dosage, particularly when used to interpret low plasma phenytoin concentrations.

A comparison of absorption rate models in the prediction of steady-state plasma concentrations during oral theophylline administration.

During therapy with oral controlled released theophylline/aminophylline, steady-state plasma drug concentrations may be predicted by fitting estimates of patient pharmacokinetic parameters to a pharmacokinetic model. The choice of model requires an assumption about the type of rate reaction of the drug absorption process (zero order or first order). In 10 subjects, plasma theophylline concentrations after a single intravenous dose of aminophylline were used to make individual estimates of drug clearance and volume of distribution. Each subject then received oral controlled release theophylline ('Theo-Dur', Fisons Pharmaceuticals plc) and steady-state pre-dose and post-dose plasma concentrations were determined. Predictions of steady-state plasma theophylline concentrations using pharmacokinetic models based on first-order (Model A) and zero order (Model 01) drug absorption were compared. Model A and Model 01 each underestimated the pre- and post-dose steady-state plasma drug concentrations. However, Model 01 was more accurate in predicting post-dose drug concentrations, whilst Model A demonstrated better precision in the prediction of pre-dose drug concentrations at steady-state (P less than 0.05).

Caffeine as a potential indicator for acetylator status.

The identification of patients as 'fast acetylators' or 'slow acetylators' is used in clinical practice to help recognize those at risk from toxicity and in guiding the dosage of N-acetylated drugs. Caffeine has been proposed as a marker for drug acetylation on the basis of a ratio of urinary metabolites (5-acetylamino-6-formylamino-3-methyl uracil and 1-methylxanthine, AFMU:MX) determined by high-performance liquid chromatography. The caffeine test was studied in 26 subjects by reference to the use of sulphamidine as the test substance. The distribution of urinary AFMU:MX ratios allowed assignment of subjects to 'slow' and 'fast' acetylator status (AFMU:MX less than 2.1 and greater than 2.3 respectively). The results showed accordance with those from the sulphadimidine test with the exception of one subject. The possible interference of concurrent administration of sulphadimidine (as an example of a drug known to undergo metabolism by N-acetylation) was also studied in 11 of the subjects. The interference was found to be small (apparent mean bias 11%) but of possible clinical significance.