The involvement of the plasma membrane in the development of Dictyostelium discoideum. I. Purification of the plasma membrane

A method for the isolation and purification of plasma membranes of Dictyostelium discoideum by equilibrium centrifugation on sucrose followed by Renografin continuous density gradients has been developed and monitored both with electron microscopy and a number of enzyme assays. On electron microscopy, the final plasma membrane fractions are judged to be freethe basis of of nuclei, rough endoplasmic reticulum, lysosomes and peroxisomes. Some profiles of the mitochondrial inner membranes are found within the plasma membrane fractions, but this contamination has been estimated to be only 5%. On the basis on enzyme assays, the plasma membrane fractions contain all the 5'-nucleotidase activity in the final gradients and are free of catalase, acid phosphatase and malate dehydrogenase activity (markers for peroxisomes, lysosomes, soluble enzymes and the matrix of mitochondria). Their content of glucose-6-phosphatase is reduced by more than 70%. The large majority of RNA and DNA have been removed from the preparation.

Regression of NMU-induced mammary tumors with the combination of melatonin and 9-cis-retinoic acid

A significant increase in tumor regression was induced in N-nitroso-N-methylurea-induced mammary tumors in rats treated with the combination of melatonin and 9-cis-retinoic acid (9cRA). Treatment groups included: control (ethanolic saline), 9cRA (30 mg/kg chow/day), melatonin 500 microg/day, melatonin 1000 microg/day, melatonin 500 microg/day+9cRA and melatonin 1000 microg/day+9cRA. Rats treated with the lower dose of melatonin 500 microg+9cRA show the greatest degree of tumor regression (78%), with 54% undergoing complete regression and a significant increase in apoptotic cells observed by TUNEL Assay. Furthermore, tumor multiplicity and burden were significantly decreased by the combination of melatonin and 9cRA.

The canine telomerase catalytic subunit (dogTERT): Characterisation of the gene promoter and identification of proximal core sequences necessary for specific transcriptional activity in canine telomerase positive cell lines

Telomerase biology is complicated by studies that show that telomere expression and telomere biology differs between species, and that existing animal models do not closely resemble the human situation. We have previously reported a description of telomere/telomerase biology in the dog and have suggested this as an alternative model system. To further elucidate telomerase biology in this species we have cloned and characterised the canine reverse transcriptase (dogTERT) promoter. We demonstrate that core promoter activity is contained within a region extending approximately 300 bp upstream of the ATG codon. Transient transfections in telomerase-positive canine cell lines and telomerase negative fibroblasts showed that the promoter is only active in telomerase positive cell lines. Sequence analysis demonstrated that the 5' regulatory region is GC-rich and contains no TATA or CAAT box, similar to the human TERT promoter. Motif searches revealed the presence of multiple transcription factor binding sites common to both the human and canine TERT promoters, including a single E-box, Sp1, AP1, MZF-2 and ER/Sp1 binding sites. These findings suggest that the dogTERT gene shares similar transcriptional control to hTERT. Identification of the core promoter necessary for activity may allow the use of naturally occurring cancers in dogs as a preclinical testing ground for telomerase targeted therapies in human cancer patients.

The pharmacist's role in primary care within an integrated health system

I read, with interest, the paper by Rosser and Kasperski. I was struck by how similar and applicable the problems and issues identified for family physicians are to those pharmacists face today in Canada's health system. There is a need for a coordinated and systematic approach to address infrastructure support for all primary-care providers. In this companion article, I will provide evidence to support the Ontario College of Family Physicians' position on strengthening family physicians' abilities to provide excellent primary care. In addition, I will make a case for support of greater involvement of pharmacists in community-based primary-care teams.

Guidelines on the management of secondary prophylaxis of vascular events in stable patients in primary care

Atherothrombosis, thrombus formation superimposed on an existing atherosclerotic plaque, is an acute process leading to ischaemic events such as myocardial infarction, stroke and critical limb ischaemia. Patients presenting with clinical conditions associated with atherothrombosis are at increased risk of subsequent vascular events. The beneficial effect of antiplatelet therapies for short-term and long-term secondary prevention of atherothrombotic events has been established. These guidelines aim to provide evidence-based recommendations that will assist in the antiplatelet-mediated secondary prophylaxis of vascular events in patients with stable cardiovascular disease treated in the primary healthcare setting. Medline and the Cochrane library were accessed using free-text strategies in the domains of antiplatelet agents and antithrombotics. Development of the guidelines was driven by a series of Steering Committee meetings, in which the quality of relevant studies was assessed and identified using narrative summary. These guidelines present evidence and recommendations for the treatment of numerous atherothrombotic indications depending on individual patient circumstances.

Development and performance of the vehicle-mounted radiation monitoring equipment used in the Maralinga rehabilitation project

The rehabilitation of the former nuclear test site at Maralinga involved (among other processes) the removal of contaminated soil from an area of approximately 2.5 km2. The two most stringent rehabilitation criteria required measurements to ensure that no radioactive particle exceeding 100 kBq of 241Am activity, and no area of 1 ha exceeding 3 kBq/m2 of 241Am activity, remained in the rehabilitated area. The project timetable required that the area be scanned at the rate of approximately 3 ha/day. Two vehicle-mounted detection systems were developed and constructed to obtain the necessary measurements in the available timeframe. The scientific basis for the designs are presented, together with details of the selected equipment and technical solutions found. The performance of this equipment in the field is discussed in terms of both its scientific and technical operation. Based on the experience gained at Maralinga, improved versions of this equipment were produced under contract for the People's Republic of China.

Molecular identification and expression analysis of tumor necrosis factor in channel catfish (Ictalurus punctatus)

A tumor necrosis factor (TNF) alpha-like gene, encoding a propeptide of 230 amino acids and a mature (soluble) peptide of 162 amino acids, was identified in channel catfish (Ictalurus punctatus). While the catfish protein shared features in common with both mammalian TNFalpha and TNFbeta homologs, overall sequence identity/similarity was slightly higher vs. TNFalpha genes when mature TNF sequences were compared. Phylogenetic analysis placed catfish and other fish TNF sequences within their own cluster apart from mammalian TNFalpha and beta genes, and supported the suggestion that TNFalpha and beta genes separated after the divergence of mammals and teleosts. In contrast to trout and carp, but similar to flounder, catfish TNF was present as a single copy gene. Expression studies demonstrated that catfish TNFalpha mRNA was present in all tested tissues (i.e. liver, spleen, head kidney, mesonephros, gill, thymus, and PBLs) from an unstimulated fish. Moreover, catfish TNF was constitutively expressed in actively proliferating, but otherwise unstimulated, macrophage (42TA) and T cell (G14D; TS32.17) lines, but not in B cell (1G8 or 3B11) or fibroblast lines. TNF expression was upregulated in PBLs, and in G14D and 42TA cells, but not in 3B11 cells, by PMA/calcium ionophore treatment. These results demonstrate that a catfish homolog of TNFalpha has been identified, and indicate that catfish TNFalpha is expressed in catfish in a manner similar to that seen in mammals.

Effects of high-calorie supplements on body composition and muscular strength following resistance training

BACKGROUND

Seventy-three healthy, male subjects randomly divided into 3 groups participated in a study to determine the effects of 2 high-calorie nutritional supplements on body composition, body segment circumferences, and muscular strength following a resistance-training (RT) program.

METHODS

In addition to their normal diets group 1 (CHO/PRO; n=26) consumed a 8.4 Mj x day(-1) (2010 kcal) high calorie, high protein supplement containing 356 g carbohydrate and 106 g protein. Group 2 (CHO; n=25) consumed a carbohydrate supplement that was isocaloric with CHO/PRO. Group 3 (CTRL; n=22) received no supplement and served as a control. All subjects were placed on a 4-day x week(-1) RT program for 8 weeks.

RESULTS

Dietary analysis revealed no significant differences in total energy consumption or nutrients at any time in the non-supplemented diets of the 3 groups. Significant (p= or <0.05) increases in body mass (BM) and fat-free mass (FFM) were observed in CHO/PRO and CHO compared to CTRL. Mean (+/- SD) increases in BM were 3.1+/-3.1 kg and 3.1+/-2.2 kg, respectively. Fat-free mass significantly (p= or <0.05) increased 2.9+/-3.4 kg in CHO/PRO and 3.4+/-2.5 kg in CHO. Muscular strength, as measured by a one-repetition maximum in the bench press, leg press, and lat-pull down increased significantly (p= or <0.05) in all groups. No significant differences in strength measures were observed among groups following training.

CONCLUSIONS

Results indicate that high-calorie supplements are effective in increasing BM and FFM when combined with RT. However, once individual protein requirements are met, energy content of the diet has the largest effect on body composition.

Improving the quality of care of musculoskeletal conditions in primary care

OBJECTIVE

To determine the support services general practitioners (GPs) need when working with patients who have musculoskeletal problems and their educational needs in order to deliver an improved service.

METHODS

GPs (n=446) on the Sheffield and Barnsley principal lists were sent a questionnaire (53.8% response rate). Semistructured interviews of a purposive sample of 10 GPs were analysed qualitatively to increase understanding of the research objectives.

RESULTS

GPs were self-confident in managing common musculoskeletal conditions such as gout (86% of GPs who replied), back pain (69%), osteoarthritis (62%) and sporting injuries (58%) entirely within the surgery. Despite high levels of confidence in diagnosing non-specific pain syndromes, 68% of GPs would refer to a rheumatologist. Most GPs (68%) were happy with their current referral rates to physiotherapists and 65% of GPs in this sample provided a personal injection service. Reduction of inappropriate prescribing of non-steroidal anti-inflammatory drugs would be helped by better patient education materials on treatments (90%) and more resources for the primary care physiotherapy service (85%). Half of the GPs had had specific musculoskeletal training within the last 5 yr. Half of the GPs planned to update their knowledge and skills in the next year, 64% of these preferring a taught interactive course, 50% wanting to sit in with a consultant in clinic and 46% preferring to learn as part of a personal learning plan.

CONCLUSIONS

GPs feel confident managing the majority of musculoskeletal conditions within the surgery provided they have adequate support in terms of opportunities for appropriate education, particularly joint injection techniques, ongoing consultant support for complex cases with poor outcomes, particularly non-specific pain syndromes, adequate access to physiotherapy, and a multidisciplinary approach to pain control and inappropriate prescribing.

Use of a cold-active entomopathogenic nematode Steinernema kraussei to control overwintering larvae of the black vine weevil Otiorhynchus sulcatus (Coleoptera: Curculionidae) in outdoor strawberry plants

Abstract

The susceptibility of overwintering black vine weevil larvae Otiorhynchus sulcatus to a cold-active entomopathogenic nematode, Steinernema kraussei (isolate L137) and a commercial proprietary biopesticide, Steinernema carpocapsae (Exhibit) was assessed on outdoor potted strawberry plants. Nematodes were applied at a range of doses in early winter at a field site located in Warwickshire, England. Three months later, infestation and mortality of vine weevils were assessed. There was a clear dose response observed for S. kraussei applications. Up to 81% of vine weevil control was recorded by this nematode at the highest dose of 60 000 nematodes per pot, whereas treatments with S. carpocapsae caused no significant mortality at the dose rates used. Dissection of vine weevil larvae showed infective juveniles had developed to adults within the host. Recovery of nematodes at the end of the experiment indicated that S. kraussei (L137) was able to survive winter field conditions including prolonged exposure to low temperatures (averaging 2.7°C during the experiment) in contrast to S. carpocapsae which showed poor survival. Of the two extraction methods used, the Baermann funnel technique was found to be more efficient than Galleria mellonella baiting, with up to 44% of the original highest dose of S. kraussei nematodes being recovered by Baermann funnel compared to 8% with G. mellonella at 18°C. These results suggest S. kraussei (L137) has potential as a commercial biocontrol agent against O. sulcatus at low temperatures.

Susceptibility of cabbage root fly Delia radicum, in potted cauliflower (Brassica oleracea var. botrytis) to isolates of entomopathogenic nematodes (Steinernema and Heterorhabditis spp.) indigenous to the UK

Abstract

The susceptibility of larvae of the cabbage root fly (Delia radicum) to ten isolates of entomopathogenic nematodes was examined in a glasshouse experiment using cauliflower (Brassica oleracea var. botrytis) as the host plant. Steinernema affine Horticulture Research International (HRI) code 179 provided the highest level of control, killing approximately 46% of the cabbage root fly within 28 days. Two Heterorhabditis isolates (HRI code K122 and UK211) and Steinernema E1 and F1 (HRI code 194 and GWE63) did not give any significant control. In a second experiment, S. affine was applied against cabbage root fly larvae at 8000 to 64 000 nematodes per pot, and its performance was compared to identical dose applications of Nemasys®, a commercial formulation of S. feltiae. Averaged over the four dose rates, S. affine controlled significantly more cabbage root fly (36%) than Nemasys® (10.4%).

Studying the epidemiology of attention-deficit hyperactivity disorder: screening method and pilot results

OBJECTIVE

As part of a larger epidemiologic study of risk factors for attention-deficit hyperactivity disorder (ADHD), this pilot study combined parent and teacher information to estimate ADHD prevalence among elementary school children in a North Carolina county. The methods developed for this study and the pitfalls we encountered illustrate the challenges involved in conducting population-based studies of ADHD.

METHODS

We employed 2-stage screening using DSM-IV criteria. Teachers completed behaviour-rating scales for all children. We then administered a structured telephone interview to parents of potential cases. We screened 362 of 424 (85%) children in grades 1 to 5 in 4 schools.

RESULTS

According to parent reports, 43 children (12%) had previously been diagnosed with ADHD by a health professional. Thirty-four children (9%) were taking ADHD medication. Forty-six children (12.7%) met study case criteria for ADHD, based on combined teacher and parent reports. Of the 46 cases, 18 (39%) had not been previously identified. Eight previously diagnosed children, however, did not meet case criteria. After we adjusted for nonresponse, the estimated prevalence was 16% (95%CI, 12% to 20%).

CONCLUSIONS

These data suggest that the DSM-IV prevalence of ADHD has been substantially underestimated, although the true prevalence in this population may be less than the 16% estimated here. Population-based studies of ADHD are feasible and may provide important information about practice and treatment patterns in community settings, as well as a broader understanding of the etiology and life course of this common disorder.

Evolution of the echinoderm Hox gene cluster

Extant echinoderms are members of an ancient and highly derived deuterostome phylum. The composition and arrangement of their Hox gene clusters are consequently of interest not only from the perspective of evolution of development, but also in terms of metazoan phylogeny and body plan evolution. Over the last decade numerous workers have reported partial Hox gene sequences from a variety of echinoderms. In this paper we used a combined methods approach to analyze phylogenetic relationships between 68 echinoderm Hox homeodomain fragments, from species of five extant classes--two asteroids, one crinoid, one ophiuroid, one holothuroid, and three echinoids. This analysis strengthens Mito and Endo's (2000) proposition that the ancestral echinoderm's Hox gene cluster contained at least eleven genes, including at least four posterior paralogous group genes. However, representatives of all paralogous groups are not known from all echinoderm classes. In particular, these data suggest that echinoids may have lost a posterior group Hox gene subsequent to the divergence of the echinoderm classes. Evolution of the highly derived echinoderm body plan may have been accompanied by class-specific duplication, diversification and loss of Hox genes.

Dehydration, hydration behavior, and structural analysis of fenoprofen calcium

Fenoprofen calcium (FC) is a nonsteroidal, anti-inflammatory, analgesic, and antipyretic agent. The dehydration behavior of FC dihydrate and the rehydration of the dried FC were investigated using differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), and powder X-ray diffractometry (PXRD). The stoichiometry, the crystal packing arrangement, and water environments in FC dihydrate were determined using single-crystal X-ray diffraction (XRD) analysis. The Arrhenius plot (natural logarithm of the dehydration rate constant versus the reciprocal of absolute temperature) for FC dihydrate from isothermal TGA is not linear. The activation energy of dehydration was 309 kJ/mol in the 50-60 degrees C range and 123 kJ/mol in the 60-80 degrees C range. The difference in activation energy can be explained from the crystal structure data where one water molecule is sandwiched between repeating polar carboxylate groups and the other water is in a slightly less polar region of the crystal. Single-crystal XRD analysis also indicated each calcium ion is coordinated to six oxygens. Two coordinating oxygens are provided by two water molecules and the other four oxygens are provided by the carboxylate group of four separate fenoprofen anions. Each fenoprofen anion, which can provide two oxygens for coordination, is associated with two different calcium ions. Hot-stage PXRD suggested that only a loss of 1 mole of water per mole of FC dihydrate (forming a monohydrate) was required to convert the material to a partially crystalline state. The monohydrate is not completely disordered as evidenced by a strong diffraction peak as well as some weaker peaks in the PXRD pattern. The rehydration of the anhydrous form of FC follows a solution-mediated transformation, prior to crystallizing as the dihydrate.

[Effect of cadmium on the phagocytic function of polymorphonuclear leukocyte in mice tested by chemiluminescence of whole blood]

The effect of cadmium chloride on the immunological toxicity of polymorphonuclear leukocyte (PMN) and on lipid peroxidation in liver were measured by using the chemiluminesence of whole blood and thiobarbituric acid (TBA) method. The results showed that 0.1 and 10 mmol/L of cadmium chloride could accelerate the chemiluminesence of whole blood in vitro, but 1000 mmol/L of cadmium chloride inhibit the chemiluminesence. Two hours after the injection of cadmium chloride through caudal vein, chemiluminesence of whole blood was induced obviously at the dose of cadmium 1 and 100 micrograms/kg BW in vivo, but the chemiluminesence was inhibited at the dose of 500 and 1000 micrograms/kg BW. At the dose of 1 microgram/kg BW, the peroxidation of liver lipids was induced. The results suggested that cadmium at low concentration accelerated the immunity of PMN, while high concentration was toxic to PMN, cadmium at low concentration could accelerate the phagocytic function of phagocytes. Phagocytosis brings about excessive active oxygen in organism and intensifies the action of active oxygen on the lipid peroxidation in tissue cells, at last, results in organic oxidation injury.

Molecular cloning, sequencing analysis and expression of the catalase-peroxidase gene from Halobacterium salinarum

The gene encoding catalase-peroxidase was cloned from chromosomal DNA from the Archaea, Halobacterium salinarum. The nucleotide sequence of a 3.5 kb fragment, containing the catalase-peroxidase gene and its flanking regions was determined. A 2.16 kb open reading frame was obtained, encoding the enzyme which was comprised of 720 amino acid residues with a calculated molecular weight of 80 kDa. The deduced amino acid sequence of the H. salinarum catalase-peroxidase showed a high degree of identity to other bifunctional catalase-peroxidases. A transcriptional start site was identified 183 bp upstream of the translational start codon. Southern blot analysis indicated that catalase-peroxidase was a single copy gene. The Archaeal catalase-peroxidase gene was expressed in Escherichia coli, and the expressed fusion protein exhibited both catalase and peroxidase activities.