Identification of three genes expressed primarily during development in Physarum polycephalum

During the life cycle of Physarum polycephalum, uninucleate amoebae develop into multinucleate syncytial plasmodia. These two cell types differ greatly in cellular organisation, behaviour and gene expression. Classical genetic analysis has identified the mating-type gene, matA, as the key gene controlling the initiation of plasmodium development, but nothing is known about the molecular events controlled by matA. In order to identify genes involved in regulating plasmodium formation, we constructed a subtracted cDNA library from cells undergoing development. Three genes that have their highest levels of expression during plasmodium development were identified: redA, redB (regulated in development) and mynD (myosin). Both redA and redB are single-copy genes and are not members of gene families. Although redA has no significant sequence similarities to known genes, redB has sequence similarity to invertebrate sarcoplasmic calcium-binding proteins. The mynD gene is closely related to type II myosin heavy-chain genes from many organisms and is one of a family of type II myosin genes in P. polycephalum. Our results indicate that many more red genes remain to be identified, some of which may play key roles in controlling plasmodium formation.

Analysis of F factor TraD membrane topology by use of gene fusions and trypsin-sensitive insertions

This report describes a procedure for characterizing membrane protein topology which combines the analysis of reporter protein hybrids and trypsin-sensitive 31-amino-acid insertions generated by using transposons ISphoA/in and ISlacZ/in. Studies of the F factor TraD protein imply that the protein takes on a structure with two membrane-spanning sequences and amino and carboxyl termini facing the cytoplasm. It was possible to assign the subcellular location of one region for which the behavior of fused reporter proteins was ambiguous, based on the trypsin cleavage behavior of a 31-residue insertion.

Physarum amoebae express a distinct fragmin-like actin-binding protein that controls in vitro phosphorylation of actin by the actin-fragmin kinase

Amoebae and plasmodia constitute the two vegetative growth phases of the Myxomycete Physarum. In vitro and in vivo phosphorylation of actin in plasmodia is tightly controlled by fragmin P, a plasmodium-specific actin-binding protein that enables actin phosphorylation by the actin-fragmin kinase. We investigated whether amoebal actin is phosphorylated by this kinase, in spite of the lack of fragmin P. Strong actin phosphorylation was detected only following addition of recombinant actin-fragmin kinase to cell-free extracts of amoebae, suggesting that amoebae contain a protein with properties similar to plasmodial fragmin. We purified the complex between actin and this protein to homogeneity. Using an antibody that specifically recognizes phosphorylated actin, we demonstrate that Thr203 in actin can be phosphorylated in this complex. A full-length amoebal fragmin cDNA was cloned and the deduced amino acid sequence shows 65% identity with plasmodial fragmin. However, the fragmins are encoded by different genes. Northern blots using RNA from a developing Physarum strain demonstrate that this fragmin isoform (fragmin A) is not expressed in plasmodia. In situ localization showed that fragmin A is present mainly underneath the plasma membrane. Our results indicate that Physarum amoebae express a fragmin P-like isoform which shares the property of binding actin and converting the latter into a substrate for the actin-fragmin kinase.

FORUM: Exploring the EIA/Environmental Management Relationship

/ An important measure of the effectiveness of environmental impact assessment (EIA) is the extent to which it achieves its goals for environmental protection and management. To determine this requires an examination of environmental outcomes for projects that have undergone EIA. The utility of the predecision stages of EIA in influencing environmental decisions has been well documented by others. It is argued here that EIA can also play a useful role in providing for ongoing adaptive environmental management. The hypothesis of this research is that EIA does influence environmental management activities and outcomes for development projects and that this influence occurs during three stages based on the principal approval decision point-predecision, postdecision, and transitional stages. This hypothesis was tested with respect to six case studies in Western Australia (WA). The majority of management actions were proposed during the predecision stage along with the formulation of impact predictions, although significant environmental management activities were established during the other stages of the EIA process. New management actions were implemented during the postdecision stage in response to the occurrence of unexpected impacts. Adaptive management activities were initiated during the transitional stage of EIA through the setting of environmental objectives in the predecision stage that left scope for a flexible approach to be adopted for achieving these objectives. During project assessment in WA, strong emphasis is placed on the need for ongoing monitoring and management programs. The implementation of these programs was found to be central to successful achievement of project and environmental performance objectives. The case studies demonstrate that a strong relationship exists between EIA and ongoing environmental management performance in WA.KEY WORDS: Environmental impact assessment; Ongoing management; Effectiveness; Audithttp://link.springer-ny.com/link/service/journals/00267/bibs/24n3p281.html

The effects of idazoxan on reaction times, eye movements and the mood of healthy volunteers and patients with upper respiratory tract illnesses

An experiment was carried out to determine whether idazoxan, a drug which increases the turnover of central noradrenaline, removes the malaise (reduced alertness, slower psychomotor performance) associated with upper respiratory tract illness (URTI). Eighty-one volunteers were tested when healthy and 17 returned to the laboratory when they developed URTIs. Those who remained healthy were then recalled as a control group. Volunteers were tested before and after receiving either idazoxan (40mg) or a lactose placebo. Idazoxan removed the URTI-induced slowing in a simple reaction time task and this group performed at a comparable level to the healthy group. No significant stimulant effect of idazoxan was found in the healthy subjects. The results suggest that at least part of the malaise induced by URTIs may reflect reductions in central noradrenaline and that this can be reversed by compounds such as idazoxan.

Effect of treatment for 6 months with human parathyroid hormone (1-34) peptide in ovariectomized cynomolgus monkeys (Macaca fascicularis)

A potential negative side effect of intermittent parathyroid hormone (PTH) therapy to treat osteoporosis is the loss of cortical bone concomitant with increased cancellous bone mass. We addressed this issue by studying the effects of PTH on whole-body, axial, and appendicular bone mass in an animal model with haversian cortical bone remodeling. Ovariectomized, young adult female cynomolgus monkeys were assigned to placebo (n = 9) or PTH groups (n = 10). The PTH group received 10 microg/kg synthetic human PTH(1-34) peptide by subcutaneous injection, 3 days/week for 6 months, and the placebo group received vehicle. Multiple endpoints of bone mass, strength, and turnover in the axial and appendicular skeleton were assessed, including dual-energy X-ray absorptiometry (DEXA), quantitative computed tomography (qCT), analysis of serum (calcium, phosphorus, alkaline phosphatase, osteocalcin, and tartrate-resistant acid phosphatase) and urinary (calcium and creatinine) biomarkers, histomorphometry, and biomechanical testing. Compared with placebo-treated animals, PTH-treated monkeys had no change in whole-body bone mass, but a 6.7% increase in spinal areal bone mineral density (aBMD) was observed. Cortical bone mass measured by qCT at appendicular sites was not affected by PTH treatment, but there were significant increases in cancellous bone mass in the proximal tibia, and a similar trend in the distal radius. Small, transient increases in serum and urinary calcium were observed, but there were no treatment-related effects on other biochemical endpoints. Increased bone formation rate (BFR/BV) in the midradius and midfemur was accompanied by a nonsignificant increase in midfemur porosity. Increased vertebral cancellous bone volume (BV/TV) was associated with greater trabecular and interstitial thickness with no effect on wall thickness. Increases in bone strength were observed in both axial (vertebral maximum stress and load at fracture) and appendicular (femoral neck fracture load) skeleton. Together, these results indicate that PTH therapy in the cynomolgus monkey results in a net gain of spinal and appendicular cancellous bone mass with no adverse effect on cortical bone.

Effect of inhaled beta 2 adrenoceptor agonist, albuterol sulphate, on performance of horses

This study was designed to test the hypothesis that a specific beta 2 adrenergic receptor agonist, albuterol sulphate, when delivered by metered-dose inhaler (MDI) would affect the performance of Thoroughbred horses during incremental exercise testing. Six conditioned Thoroughbred horses were randomly assigned to one of 2 treatment groups: Group 1 horses received placebo and Group 2 received albuterol. Each horse received both treatments in a crossover design with a 3 week interval between trials. Horses inspired albuterol (900 micrograms) or placebo over a 5 min period followed by an incremental, peak oxygen consumption (VO2peak) exercise test. Facial arterial blood gases (PaO2, PaCO2), pHa, temperature, haemoximetry (O2Hb, COHb, MetHb, RHb) and electrolytes (Na+, K+, iCa2+, Cl-) were measured. Heart rate (HR), VO2peak, CO2 production (VCO2), plasma lactate, speed at failure, exercise duration, and urine levels of albuterol and metabolites (Alburine) were monitored. The Paratrend7 intravascular sensor provided continuous arterial blood gas data. Mixed effects linear modelling using generalised least-squares estimation was used to assess treatment and speed main effects interaction. Significant differences (P < 0.01) were found between placebo and albuterol-treated horses for total run time (mean +/- s.e. 405.8 +/- 8.8 vs. 430.5 +/- 6.7 s) and run time from completion of 8 m/s until fatigue (169.3 +/- 8.6 vs. 187.3 +/- 6.7 s), as well as VO2peak (121.7 +/- 3.7 vs. 130.3 +/- 3.8 ml/kg/min), respectively. In conclusion, inhaled albuterol sulphate has a small but significant effect on the performance of fit Thoroughbred horses during incremental, VO2peak exercise testing.

An MRI study of the basal ganglia in autism

1. High-resolution MRI scans were obtained from 35 relatively high-functioning persons with autism and 36 healthy controls, comparable in age, gender, and IQ. 2. Volumetric measurements were obtained from manual tracing of the bilateral caudate, putamen, and globus pallidus. 3. An increased volume of the caudate nuclei was found in subjects with autism. Caudate enlargement was proportional to increased total brain volume in subjects with autism. 4. Caudate volume was associated with compulsions and rituals, difficulties with minor change, and complex motor mannerisms in autism. 5. Based on evidence of caudate abnormalities, a second MRI study was completed which replicated the finding of caudate enlargement in autism using an independent sample. 6. The caudate may be part of an abnormal distributed neural network in autism and involved in the ritualistic--repetitive behaviors of the disorder.

The differential expression of myometrial connexin-43, cyclooxygenase-1 and -2, and Gs alpha proteins in the upper and lower segments of the human uterus during pregnancy and labor

There is evidence from many studies indicating that a number of specific quiescent and contractile associated proteins are temporally regulated in the myometrium during pregnancy. In this present investigation we provide data that strongly suggest that myometrial connexin-43, cyclooxygenase-1 and -2 (COX-1 and -2), and Gs alpha proteins are also spatially expressed within the human uterus during pregnancy and labor. Using paired lower and upper segment myometrial samples taken from individual women at term and during spontaneous labor, we have measured the expression of these proteins by immunoblotting with specific antibodies. We report that the myometrial gap junction connexin-43 protein is expressed at much greater levels in the upper uterine compared to the lower uterine segment and that this difference is even more pronounced during the course of labor. Conversely, myometrial COX-1 and -2 proteins appear to be expressed at much greater levels in the lower compared to the upper uterine segment. Moreover, the level of expression of both proteins is unaffected by the onset of parturition. In contrast, myometrial Gs alpha protein appears to be uniformly expressed in both lower and upper segments and is similarly down-regulated during parturition, as previously reported. The differential expression of COX-1 and -2 and connexin-43 in the uterus may allow cervical ripening before and dilatation during labor and facilitate effective propagation of contractions from fundus to cervix, which may be further facilitated by the down-regulation of Gs alpha at the onset of parturition.

Colposuspension after previous failed incontinence surgery: a prospective observational study

OBJECTIVE

To evaluate the outcome of colposuspension for genuine stress incontinence in women who had previously undergone bladder neck surgery.

DESIGN

Prospective observational study.

SETTING

Tertiary referral urogynaecology unit.

PARTICIPANTS

Fifty-two consecutive women with recurrent genuine stress incontinence operated on by one surgeon.

MAIN OUTCOME MEASURES

Subjective and objective cure of stress incontinence. Complications of surgery.

RESULTS

The mean age of the women was 51 years (range 28-72) and weight 72.7 kg (range 53-112). Sixty-five continence procedures had been performed previously, with 13 women (25%) having had more than one operation. Nine months post-operatively the subjective cure rate was 80% and objective cure rate 78%. Intraoperative complications were few but included two bladder injuries and one rectus muscle tear which required repair. Seven women (13%) developed voiding difficulties which required clean intermittent self-catheterisation, but only one needed to continue this for six months. None of the women developed detrusor instability.

CONCLUSIONS

In this setting colposuspension after previous bladder neck surgery offers a high rate of success. However, long term follow up is needed to see if this effect is maintained.

Unilateral adrenal medullary hyperplasia: another form of curable hypertension?

A case of unilateral adrenal medullary hyperplasia is presented in a 49-year-old caucasian female without multiple endocrine neoplasia association. The patient presented with episodic hypertension and paroxysms suggesting an underlying phaeochromocytoma. Biochemical supported this diagnosis but no discrete tumour was found on preoperative localising studies or at the time of surgery. The patient underwent a unilateral adrenalectomy with confirming adrenal medullary hyperplasia with complete resolution of her symptoms for six months.

Is follow up by specialists routinely needed after elective surgery? A controlled trial

STUDY OBJECTIVE

To assess the benefit of planned specialist follow up appointments after elective inpatient surgery.

DESIGN

This was a controlled trial, using repeated alternate allocation of time periods to the two study groups. Group 1: Planned outpatient follow up 6-12 weeks after surgery. Group 2: No planned follow up: additional written information for patients and general practitioners.

SETTING

A district general hospital in the north west of England.

PARTICIPANTS

264 patients listed for one of: transurethral resection of the prostate, varicose vein surgery, cholecystectomy (open or laparoscopic), inguinal herniorraphy (open or laparoscopic).

MAIN OUTCOME MEASURES

Health status, complications, return to normal activity, patient satisfaction, use and costs of primary and secondary care in the 12 weeks after surgery.

MAIN RESULTS

Data were available for 212 (80%) of eligible patients. Thirty eight per cent of patients in the "no planned follow up" group were in fact seen in outpatients after their discharge. Intention to treat analysis showed that there were no significant differences between the groups for health status, complications, or time to return to normal activity. Patients in the "no planned follow up" group had significantly fewer hospital visits and costs (mean difference in visits 0.51, 95% confidence intervals 0.39 to 0.69; mean difference in hospital costs 12.75 Pounds, 9.75 Pounds to 15.50 Pounds). There were fewer primary care staff contacts and costs in the "no planned follow up" group, although this difference was not significant (mean difference = 0.61 visits, -0.13 to 1.33 visits; primary care costs difference 8.37 Pounds, -1.31 Pounds to 18.73 Pounds). Patients in the "no planned follow up group" had significantly reduced patient travel costs (mean difference 4.84 Pounds, 3.44 Pounds to 6.22 Pounds). Eighty nine (42%) patients would prefer to be followed up by both their hospital doctor and GP; 53 (25%) patients would prefer to be followed up by the hospital doctor only. There were no significant differences between the two groups in their preferences for follow up. The majority of GPs agreed with the statement that a policy of no follow up at hospital outpatients for each of the six surgical procedures would increase their workload.

CONCLUSIONS

Planned outpatient appointments after uncomplicated surgery seem to be neither necessary nor cost effective. A policy of "no planned follow up" results in no increase in primary care costs, and savings in hospital and patient costs. However, many patients expected and wanted to be seen again by their surgeon and GPs were concerned that a "no follow up" policy would result in an increase in workload.

Integrated Management of Sclerotinia Blight in Peanut: Utilizing Canopy Morphology, Mechanical Pruning, and Fungicide Timing

Sclerotinia blight of peanut, caused by Sclerotinia minor, generally becomes severe only after vines meet in the row middles and a dense canopy develops. Dense foliage appears to support a microclimate conducive to the colonization of peanut limbs by S. minor. Removal of excess foliage before and during a Sclerotinia blight epidemic on the susceptible genotype NC 7 has been shown to reduce the rate of disease progress. Field tests in 1993 and 1994 examined control of Sclerotinia blight among four peanut genotypes (NC 7, VA 93B, NC Ac 18016, and Tam-span 90) with diverse canopy morphologies. Each cultivar had foliage pruned with a rotary mower once (1993 and 1994) or twice (1994) during the season. Applications of fluazinam (9.2 kg a.i./ha) were imposed on the genotype × pruning treatments. Soil temperatures under the canopy of each genotype and pruning treatment were measured and compared. Disease data were collected weekly by counting the number of feet of plants exhibiting lesions with visible fungus growth. Tamspan 90, a resistant Spanish peanut, had the least Sclerotinia blight incidence. Pruning measurably affected soil temperature for approximately 2 weeks following pruning. Removal of foliage reduced disease and increased disease control affected by fluazi-nam in fields with high disease pressure. In some tests, yields were increased by pruning through a reduction in disease pressure. Yields were lower when peanuts were pruned excessively, especially late in the season. Pruning of excessive vine growth can be an alternative, or complement, to fungicide treatments when done in midseason during favorable weather when moderate to high disease pressure occurs.

The tao of professional appraisal: how to remain content and calm during the appraisal interview

AIM

This paper sets out to investigate the theories and practices of healthcare appraisal systems, with particular emphasis on the appraisal of healthcare educators.

BACKGROUND

The rhetoric used to inform appraisal theories, systems and practices claims to measure human attributes, although this is rarely achieved in reality.

METHOD

A national survey of healthcare educators is used to inform, analyse and evaluate the literature pertaining to professional appraisal theories and systems.

FINDINGS

The main theme to emerge centres around the inadequacies of current appraisal systems and practices.

CONCLUSION

Nurse educators and healthcare professionals should be creative and proactive in their approaches to the appraisal process, to enable more effective and meaningful appraisal processes and outcomes.

Mutant membrane protein toxicity

This report describes an extensive mutational analysis of the most carboxyl-terminal membrane-spanning sequence of Escherichia coli lac permease (TM12). In addition to identifying residues important for lactose transport function, the analysis revealed that numerous mutations made lac permease highly toxic to cells. In the most extreme cases, production of such proteins at very low steady-state levels reduced cell viability greater than 10(4)-fold. Both frameshift and missense mutations led to toxicity, with the frameshift mutations having the strongest effects observed. The toxic missense mutations corresponded to changes in TM12 expected to interfere with membrane insertion or folding, such as the introduction of charged residues or prolines in the putative helix. The results suggest that cellular toxicity may be a relatively common consequence of mutations altering integral membrane protein folding. An analogous toxicity might contribute to the pathogenesis of several degenerative diseases caused by mutant membrane proteins, such as retinitis pigmentosa, Charcot-Marie-Tooth syndrome, and Alzheimer's disease.

Parent-of-origin effects on seed development in Arabidopsis thaliana

Many flowering plants are polyploid, but crosses between individuals of different ploidies produce seeds that develop abnormally and usually abort. Often, seeds from interploidy crosses develop differently depending on whether the mother or father contributes more chromosome sets, suggesting that maternal and paternal genomes are not functionally equivalent. Here we present the first cytological investigation of seed development following interploidy crosses in Arabidopsis thaliana. We find that crosses between diploid and tetraploid plants in either direction, resulting in double the normal dose of maternal or paternal genomes in the seed, produce viable seeds containing triploid embryos. However, development of the seed and in particular the endosperm is abnormal, with maternal and paternal genomic excess producing complementary phenotypes. A double dose of maternal genomes with respect to paternal contribution inhibits endosperm development and ultimately produces a smaller embryo. In contrast, a double dose of paternal genomes promotes growth of the endosperm and embryo. Reciprocal crosses between diploids and hexaploids, resulting in a triple dose of maternal or paternal genomes, produce seeds that begin development with similar but more extreme phenotypes than those with a double dose, but these invariably abort. One explanation of our observations is that seeds with maternal or paternal excess contain different doses of maternally or paternally expressed imprinted loci affecting endosperm development.

Circular polarization in star-formation regions: implications for biomolecular homochirality

Strong infrared circular polarization resulting from dust scattering in reflection nebulae in the Orion OMC-1 star-formation region has been observed. Circular polarization at shorter wavelengths might have been important in inducing chiral asymmetry in interstellar organic molecules that could be subsequently delivered to the early Earth by comets, interplanetary dust particles, or meteors. This could account for the excess of L-amino acids found in the Murchison meteorite and could explain the origin of the homochirality of biological molecules.

Integrating the cognitive and physiological aspects of craving

'Craving is generally considered a significant factor in opiate addiction that is associated with drug-dependence and in relapse to drug use after treatment'-ARC expert consensus (Pickens and Johanson, Drug and Alcohol Dependence 30: 127-131). There are however difficulties in defining craving and urges to use drugs and in associating craving with drug use and relapse. Tiffany [Psychological Review 97(2): 147-168] has reviewed a considerable number of studies that associated reports of craving with consumption measures of drugs and revealed only an overall modest correlation of 0.4. These findings call into question the general assumption that subjective cravings are invariably associated with drug use. Furthermore, it led to Tiffany's provocative argument that cravings are not necessary for drug use. We have addressed these issues by using a range of complementary techniques derived from research in related fields such as the cognitive psychology of anxiety and depression, physiological response measurements and positron emission tomography (PET) neuro-imaging. Initially we developed computerized assessments to probe cognitive dysfunction in addiction that related to biased processing of automatic thoughts and beliefs about craving and drug use in opiate-dependent subjects and alcoholics. Subsequently in an attempt to develop a reliable method of inducing craving we explored an imagery-based technique that relied on the memory of craving experiences. These experiments were conducted both in opiate addicts who had achieved abstinence and in those undergoing detoxification. Finally, we have begun a study to understand the neural mechanisms of craving using imagery-based procedures at the same time as performing PET studies of regional blood flow using the O15-labelled water technique.

No difference in hippocampus volume detected on magnetic resonance imaging in autistic individuals

Neuropathological and animal studies have implicated the hippocampus as having a potential role in autism. Current imaging methods are well suited to the detailed measurement of the volume of the hippocampus, which has received little attention in previous imaging studies in autism. We report the results of a magnetic resonance imaging (MRI) study of 35 autistic and 36 control subjects. Detailed (1.5 mm) MRI did not reveal differences in the volume of the hippocampus in autistic individuals.

Missense mutations that inactivate Escherichia coli lac permease

Although missense mutations that inactivate integral membrane proteins cause a variety of diseases, the mechanisms by which they act are poorly understood. To establish a model for investigating this issue, we identified 51 missense mutations arising in vivo that inactivate Escherichia coli lac permease, a well-characterized membrane transport protein. The mutants were isolated using a genetic screening procedure which eliminates mutations that block expression of the lac permease gene, such as nonsense and frameshift mutations. The majority of the 51 missense mutations caused highly non-conservative changes in membrane-spanning sequences, such as the introduction of charged residues. Nevertheless, the greatest clustering of substitutions occurred in the two regions of lac permease thought to be most important for transport function. The existence of this clustering indicates that even highly non-conservative substitutions may cause relatively localized structural defects. Conservative inactivating substitutions were scattered throughout lac permease and may affect residues that make contacts required for normal folding. Two unexpected phenotypes were observed in the collection of mutants: about 20% of the substitutions led to cold-sensitive lactose utilization, and one substitution made the mutant lac permease toxic to cells. This relatively unbiased collection of mutants should provide a resource for further studies of how missense mutations inactivate membrane proteins in vivo.