Endogenous cell surface lectin in Dictyostelium: quantitation, elution by sugar, and elicitation by divalent immunoglobulin.

The amount of total endogenous cellular and cell surface lectin in aggregating Dictyostelium purpureum was determined by a number of immunochemical techniques. The results show that of the 5 x 10(6) molecules of the lectin (called purpurin) per aggregating cell only about 2% (1 x 10(5) molecules) is present on the cell surface. Cell surface purpurin can be specially eluted by lactose, which indicates that it is held to the surface by its carbohydrate-binding site. The eluted purpurin is replaced on the cell surface within 45 min. Estimates of cell surface purpurin made by binding of specific immunoglobulin to the cells at 4 degrees C indicate that a much larger amount, about 1 x 10(6) molecules, becomes associated with the cell surface in the presence of this divalent ligand. In contrast, univalent antibody fragments do not have this effect.

Comparison of developmentally regulated lectins from three species of cellular slime mold.

Extracts of the cohesive forms of the cellular slime molds Dictyosteliym discoideum, Dictyostelium mucoroides and Dictyostelium purpureum contain lectin activity, assayed as hemagglutination activity. The lectin activity from each species binds quantitatively to Sepharose 4B and can be eluted with D-galactose. The resultant purified lectins are abundant proteins representing, in the case of D. purpureum, up to 5% of the total soluble protein of cohesive cells. The preparations from each species are similar but distinct in amino acid composition and other properties. Each purified preparation gives rise to two protein bands on sodium dodecyl sulfate-polyacrylamide gel electrophoresis with the major band representing as little at 77% (D. purpureum) and as much as 96% (D. mucoroides) of the total protein in the two bands. The molecular weights of the pair of bands were different for each species, ranging between about 23 000 and 26 000. The two bands are believed to represent subunits of lectins made up of either one or a combination of these two proteins. The apparent molecular weights of the purified lectin activities determined by sucrose density gradient centrifugation were all in the range of 100 000. N-Acetyl-D-galactosamine was a potent inhibitor of the hemagglutination activity of each perparation; but there were some differences in the relative inhibitory potency of a number of other saccharides. Antiserum raised against each preparation, as well as univalent antibody fragments derived from these antisera, reacted best with the antigens to which they were raised; but showed some cross reaction measured both by precipitin reactions and by inhibition of hemagglutination activity of the purified lectins. The differences between the lectins from the different species could be trivial; but they also could be important for defining specific properties of these three species which reliably segregate into colonies of a single species when grown in mixed culture.

Self-management education and regular practitioner review for adults with asthma.

BACKGROUND: A key component of many asthma management guidelines is the recommendation for patient education and regular medical review. A number of controlled trials have been conducted to measure the effectiveness of asthma education programmes. These programmes improve patient knowledge, but their impact on health outcomes is less well established. This review was conducted to examine the strength of evidence supporting Step 6 of the Australian Asthma Management Plan: "Educate and Review Regularly"; to test whether health outcomes are influenced by education and self-management programmes. OBJECTIVES: The objective of this review was to assess the effects of asthma self-management programmes, when coupled with regular health practitioner review, on health outcomes in adults with asthma. SEARCH STRATEGY: We searched the Cochrane Airways Group trials register and reference lists of articles. SELECTION CRITERIA: Randomised trials of self-management education in adults over 16 years of age with asthma. DATA COLLECTION AND ANALYSIS: Trial quality was assessed and data were extracted independently by two reviewers. Study authors were contacted for confirmation. MAIN RESULTS: Thirty six trials, which compared self-management education with usual care, were included. Self-management education reduced hospitalisations (relative risk 0.64, 95% confidence interval 0.50 to 0.82); emergency room visits (relative risk 0.82, 95% confidence interval (0.73 to 0.94); unscheduled visits to the doctor (relative risk 0.68, 95% confidence interval 0.56 to 0.81); days off work or school (relative risk 0.79, 95% confidence interval 0.67 to 0.93); nocturnal asthma (relative risk 0.67, 95% confidence interval 0.0.56 to 0.79); and quality of life (standard mean difference 0.29, confidence interval 0.11 to 0.47). Measures of lung function were little changed. REVIEWER'S CONCLUSIONS: Education in asthma self-management which involves self-monitoring by either peak expiratory flow or symptoms, coupled with regular medical review and a written action plan improves health outcomes for adults with asthma. Training programmes that enable people to adjust their medication using a written action plan appear to be more effective than other forms of asthma self-management.

Analysis of polycyclic aromatic hydrocarbons in metered dose inhaler drug formulations by isotope dilution gas chromatography/mass spectrometry.

Organic compounds extracted into metered dose inhalers (MDIs) from the rubber components of the metering valve are of increasing interest in the development of these formulations. Polycyclic aromatic hydrocarbons (PAHs) are a class of extractable organic compounds whose source is the carbon black commonly used as a reinforcing agent in rubber. The analytical method for PAHs described in this report employs "cold filtration" to remove the suspended drug substance and excipients, and gas chromatography/mass spectrometry (GC/MS) for separation and detection of individual PAHs. After filtration, stable isotope labelled analogues of target PAHs are spiked into the drug product to act as internal standards, correcting for recovery (termed "isotope dilution GC/MS"). Validation of the method was accomplished with respect to linearity, precision, limit of detection/quantitation, selectivity and ruggedness. Application to a variety of MDI drug product formulations revealed that certain PAHs are present at the ng/inhaler level.

Chromatographic methods for determining the identity, strength and purity of ranitidine hydrochloride both in the drug substance and its dosage forms--an exercise in method selection, development, definition and validation.

The selection, development, definition and validation of selective stability-indicating procedures for high-performance liquid chromatographic and thin-layer chromatographic analyses of ranitidine hydrochloride are described. The procedures used in conjunction can be applied to the quality assurance and stability assessments of both the drug substance and its dosage forms and serve to establish the identity, strength and purity of this drug used in the treatment of peptic ulcer and related conditions.

The excretion of theobromine in Thoroughbred racehorses after feeding compounded cubes containing cocoa husk--establishment of a threshold value in horse urine.

Thoroughbred geldings were fed racehorse cubes containing a predetermined concentration of theobromine in the form of cocoa husk. They were offered 7 kg of cubes per day, divided between morning and evening feed, and food consumption was monitored. Urinary concentrations of theobromine were determined following the consumption of cubes containing 11.5, 6.6, 2.0 and 1.2 mg per kg of theobromine, to verify whether or not such concentrations would produce positive urine tests. Pre-dose urine samples were collected to verify the absence of theobromine before each experiment. It became apparent from the results of the first three administrations that the limit of detection of theobromine, using such procedures, would be reached at a feed level of about 1 mg per kg theobromine. Therefore the final administration, using cubes containing 1.2 mg per kg theobromine, was singled out for additional analytical work and quantitative procedures were developed to measure urinary concentrations of theobromine. It was anticipated that the results would form a basis for discussions relating to the establishment of a threshold value for theobromine in horse urine. The Stewards of the Jockey Club subsequently gave notice that they had established a threshold level for theobromine in urine of 2 micrograms/ml.

A gas chromatographic screening procedure for the detection of non-steroidal anti-inflammatory drugs in horse urine.

A gas chromatographic screening procedure for the non-steroidal anti-inflammatory group of drugs is described. The method invovles on-column methylation of the carboxylic acid group using trimethylanilinium hydroxide as the methylating reagent. Fifteen such drugs were studied. Eight of these were detected in urine collected from horses that had received these compounds orally and for these drugs, rates of urinary excretion are recorded. Seven other members of this group of drugs were shown to be detectable by this procedure but in these cases the drug was added to urine and not administered to the horse.

Theory verses empiricism in health economics. An analysis of the past 20 years.

We report the results of a study analyzing the proportion of theoretical and empirical articles in two core health economics journals. The Journal of Health Economics published 30% theory during the period 1982-1986, but by 1997-2001 the proportion had risen to 40% theory. Health Economics published 38% theory during 1992-1996, but the proportion fell to 32% theory during 1997-2001. In both journals articles were more likely to be published by men (78%), and published women were 50% less likely to publish theory than were men. Articles were more likely to be published by United States authors (54%), but United States authors were less likely to publish theory than authors from other countries. Compared to other disciplines, health economics published a higher proportion of theory than sociology, chemistry, and physics but less than economics and political science.

General anesthesia for disabled patients in dental practice.

We reviewed the cases of 91 consecutive patients with disabilities who required general anesthesia at a tertiary referral center for dental treatment with a view to determining the factors that create difficulties in the anesthetic management. The more important of these are the special difficulties involved in making preoperative assessments of these patients and the difficulty in establishing monitoring. Other difficulties in anesthesia for these patients involve problems with gaining intravenous access, problems in determining when there has been adequate recovery from anesthesia, and problems in determining the degree of discomfort or pain the patients experience after dental treatment. Another potential hazard in this group of patients is the risk of drug interactions. We emphasize the need to train anesthetists in the care of disabled patients.

Movement disorder emergencies in childhood.

The literature on paediatric acute-onset movement disorders is scattered. In a prospective cohort of 52 children (21 male; age range 2mo-15y), the commonest were chorea, dystonia, tremor, myoclonus, and Parkinsonism in descending order of frequency. In this series of mainly previously well children with cryptogenic acute movement disorders, three groups were recognised: (1) Psychogenic disorders (n = 12), typically >10 years of age, more likely to be female and to have tremor and myoclonus (2) Inflammatory or autoimmune disorders (n = 22), including N-methyl-d-aspartate receptor encephalitis, opsoclonus-myoclonus, Sydenham chorea, systemic lupus erythematosus, acute necrotizing encephalopathy (which may be autosomal dominant), and other encephalitides and (3) Non-inflammatory disorders (n = 18), including drug-induced movement disorder, post-pump chorea, metabolic, e.g. glutaric aciduria, and vascular disease, e.g. moyamoya. Other important non-inflammatory movement disorders, typically seen in symptomatic children with underlying aetiologies such as trauma, severe cerebral palsy, epileptic encephalopathy, Down syndrome and Rett syndrome, include dystonic posturing secondary to gastro-oesophageal reflux (Sandifer syndrome) and Paroxysmal Autonomic Instability with Dystonia (PAID) or autonomic 'storming'. Status dystonicus may present in children with known extrapyramidal disorders, such as cerebral palsy or during changes in management e.g. introduction or withdrawal of neuroleptic drugs or failure of intrathecal baclofen infusion; the main risk in terms of mortality is renal failure from rhabdomyolysis. Although the evidence base is weak, as many of the inflammatory/autoimmune conditions are treatable with steroids, immunoglobulin, plasmapheresis, or cyclophosphamide, it is important to make an early diagnosis where possible. Outcome in survivors is variable. Using illustrative case histories, this review draws attention to the practical difficulties in diagnosis and management of this important group of patients.

Survivin expression in in situ and invasive breast cancer relates to COX-2 expression and DCIS recurrence.

In lung cancer cyclooxygenase-2 (COX-2) expression has been reported to stabilise survivin, an inhibitor of apoptosis (IAP) which prevents cell death by blocking activated caspases. COX-2 expression limits the ubiquitination of survivin, protecting it from degradation. To determine if COX-2 expression in breast cancer showed an association with survivin expression, we assessed the levels of each protein in ductal carcinoma in situ (DCIS) and invasive breast cancer (IBC); relating expression patterns to recurrence of DCIS after surgery. Patterns of COX-2 and survivin expression were determined by intensity-graded immunohistochemistry of the primary tumours. Patients with DCIS (n=161) which had either recurred (n=47) or shown no evidence of recurrence (n=114) 5 years following primary surgery were studied. These were compared to 58 cases of IBC. Survivin was expressed in the cytoplasm of 59% of DCIS and 17% of IBC. High levels of both cytoplasmic survivin and COX-2 expression significantly correlated to DCIS recurrence. COX-2 expression was present in 72% of DCIS, and levels of expression positively correlated with cytoplasmic survivin expression in DCIS and invasive disease. The majority of DCIS that recurred expressed both proteins (69%) vs 39% nonrecurrent. Recurrence was not seen in DCIS lacking both proteins at 5 years (P=0.001). Expression of the IAP survivin is increased in DCIS and correlates closely with COX-2 expression. Increased expression of IAP, (leading to reduced apoptosis) may explain the effect of COX-2 in increasing recurrence of DCIS after surgical treatment.