Agonist-, antagonist-, and inverse agonist-regulated trafficking of the delta-opioid receptor correlates with, but does not require, G protein activation

In this study, we explored the relationship between ligand-induced regulation of surface delta opioid receptors and G protein activation. G protein activation was assessed with [(35)S]guanosine-5'-O-(3-thio)triphosphate (GTP gamma S) binding assays conducted at both 37 and 0 degrees C. Ligand-independent (constitutive) activity of the delta-receptor was readily observed when the [(35)S]GTP gamma S binding assay was performed at 37 degrees C. We identified a new class of alkaloid inverse agonists (RTI-5989-1, RTI-5989-23, RTI-5989-25), which are more potent than the previously described peptide inverse agonist ICI-174864 (N,N-diallyl-Tyr-Aib-Aib-Phe-Leu). Treatment with these inverse agonists for 18 h caused up-regulation of surface receptors. Eighteen-hour treatment with etorphine resulted in approximately 90% loss of surface receptor, whereas fentanyl, diprenorphine, and morphine caused between 20 and 50% loss. The abilities of ligands to modulate [(35)S]GTP gamma S binding at 37 degrees C showed a strong correlation with their abilities to regulate surface receptor number (r(2) = 0.86). Interestingly, the ability of fentanyl to activate G proteins was markedly temperature sensitive. Fentanyl showed no stimulation of [(35)S]GTP gamma S binding at 0 degrees C but was as efficacious as etorphine, morphine, and diprenorphine at 37 degrees C. Neither the ligand-induced receptor increases nor decreases were perturbed by pertussis toxin pretreatment, suggesting that functional G proteins are not required for ligand-regulated delta-opioid receptor trafficking.

Prevalence and risk factors of chronic venous insufficiency

Venous disease in the legs occurs very commonly in the general population in Western countries. Around one third of women have trunk varices. A lower prevalence has been observed in men but some recent surveys have suggested that the occurrence in men may be comparable to that in women. The prevalence increases with age but the incidence of new cases appears to be constant throughout adult life. Open venous ulcers occur in about 0.3% of the adult population and a history of open or healed ulceration occurs in around 1%. The etiology of chronic venous disease in the legs is unknown. A genetic predisposition may be present but evidence for this and for a mode of inheritance is lacking. There is some suggestion that prolonged standing may be a risk factor but studies are open to considerable bias. In women, obesity and previous pregnancy has been associated with the presence of varicose veins but the evidence is inconsistent. There have been few well-conducted studies examining diet and bowel habit as a risk factor. The risk of ulceration is related to the severity of varicosities and venous insufficiency, and is increased following deep vein thrombosis. Much further research is required to investigate the cause of this common condition in the general population.

Lifestyle risk factors for lower limb venous reflux in the general population: Edinburgh Vein Study

BACKGROUND

Varicose veins occur commonly in the general population but the aetiology is not well established. Varicosities are associated frequently with reflux of blood in the leg veins due to valvular incompetence. Our aim was to determine in the general population which lifestyle factors were related to reflux and thus implicated in the aetiology of varicose veins.

METHODS

In the Edinburgh Vein Study, 1566 men and women aged 18-64 years were sampled randomly from the general population in the city of Edinburgh, Scotland, and had duplex scans to measure reflux in eight venous segments in each leg. A self-administered questionnaire enquired about occupation, mobility at work, smoking, obstetric history, dietary fibre intake and bowel habit. A bowel record form was completed subsequently.

RESULTS

In women, venous reflux was associated with decreased sitting at work (odds ratio [OR] = 0.76, 95% CI : 0.61-0.94), previous pregnancy (OR = 1.20, 95% CI : 0.93-1.54), and a lower prior use of oral contraceptives (OR = 0.84, 95% CI : 0.66-1.06). Mean body mass index was greater in women with superficial reflux compared to those with no reflux: 26.2 kg/m(2) (95% CI : 25.5-27.0) versus 25.2 kg/m(2) (95% CI : 24.8-25.6). On age adjustment, sitting at work remained related to reflux (OR = 0.78, 95% CI : 0.63-0.98) and prior use of oral contraceptives to superficial reflux (OR = 0.71, 95% CI : 0.50-1.01). In age-adjusted analyses in men, height was related to reflux, (OR = 1.13, 95% CI : 1.02-1.26) and straining at stool was related to superficial reflux (OR = 1.94, 95% CI : 1.12-3.35). No associations were found in either sex between reflux and social class, lifetime cigarette consumption, dietary fibre intake and intestinal transit time.

CONCLUSIONS

This population study did not identify strong and consistent lifestyle risk factors for venous reflux although previous pregnancy, lower use of oral contraceptives, obesity and mobility at work in women and height and straining at stool in men may be implicated.

Differential splicing of transcripts encoding the orphanin FQ/nociceptin precursor

Orphanin FQ or nociceptin (OFQ/N), the heptadecapeptide agonist for the NOP receptor, is derived by proteolytic processing from a precursor protein, preproOFQ/N. Previous studies have reported alternative splicing between exons 3 and 4 of the mouse OFQ/N transcript, which, upon translation, would yield precursor proteins with different C-termini. Using RT-PCR, we identified similar alternative splicing of preproOFQ/N transcripts in humans and rats. In addition, we identified two novel human preproOFQ/N splice variants from which exon 2 has been excised and which also undergo alternative splicing between exons 3 and 4. Exon 2 contains the translational start site for preproOFQ/N and encodes the signal peptide sequence. In vitro translation of cRNAs lacking exon 2 yields shorter translation products which arise from an alternative initiator methionine located within exon 3. The resulting proteins would lack a signal peptide sequence, which would likely alter their cellular trafficking and processing.

Fiber intake, constipation, and risk of varicose veins in the general population: Edinburgh Vein Study

The purpose of the present study was to determine the relationship between fiber intake, constipation, and clinical venous disease in the general population. The Edinburgh Vein Study was comprised of 1566 men and women aged 18-64 years who were selected at random from the age-sex registers of 12 general practices. Fiber intake, intestinal transit time, defecation frequency and the prevalence of straining at stool were all found to be significantly different between the sexes. Men who reported that they strained to start passing a motion showed a higher prevalence of mild and severe trunk varices compared to men who did not strain. After adjustment for social class, BMI and mobility at work, this group of men showed a significantly elevated risk of having severe trunk varices (OR 2.76, 95% CI 1.16, 6.58). In contrast, no consistent relationships were seen among women. Overall, within this Western general population, an association between dietary fiber, constipation and the presence or severity of varicose veins was not supported.

Expression of MsLEC1- and MsLEC2-antisense genes in alfalfa plant lines causes severe embryogenic, developmental and reproductive abnormalities

Although it has been proposed that plant lectins play a number of roles, the function of these proteins in normal plant growth and development has been unclear. To analyze the functions of putative alfalfa lectin genes, lines of transgenic alfalfa plants expressing approximately half of the open reading frame of MsLEC1 or MsLEC2, in the antisense or sense orientation, were established and analyzed. The antisense plants displayed severe abnormalities in embryogenesis, and both vegetative and reproductive development were perturbed. Some differences were observed between MsLEC1- and MsLEC2-antisense plants, and abnormalities were especially severe during the early stages of development in both the primary and secondary transgenic generations. In contrast, vector-control and sense-transgene plants exhibited normal growth and development. MsLEC1 and MsLEC2 mRNA accumulation levels were reduced in cognate antisense plants, especially during the later stages of embryogenesis, but also tended to be low in MsLEC1 sense-transgene plants. However, correlated with the phenotypic abnormalities observed in the MsLEC1-antisense plants was the specific reduction in the accumulation of a candidate MsLEC1 protein. Our results suggest that the MsLEC1 and MsLEC2 gene products, in addition to being important for embryogenesis, are required throughout alfalfa development.

Neurotrophin dependence domain: a domain required for the mediation of apoptosis by the p75 neurotrophin receptor

The mechanisms underlying neurotrophin dependence, and cellular dependent states in general, are unknown. We show that a 29 amino acid region in the intracellular domain of the common neurotrophin receptor, p75NTR, is required for the mediation of apoptosis by p75NTR. Furthermore, contrary to results obtained with Fas, monomeric p75NTR is required for apoptosis induction, whereas multimerization inhibits the pro-apoptotic effect. Within the 29-residue domain required for apoptosis induction by p75NTR, a 14-residue region is sufficient as a peptide inducer of apoptosis. This 14-residue peptide requires the positively charged carboxyterminal residues for its effect on cell death, and these same residues are required by the full-length p75NTR. These studies define a novel type of domain that mediates neurotrophin dependence, and suggest that other cellular dependent states may be mediated by proteins displaying similar domains.

Hyperfine Structure in the Rotational Spectrum of GaF: A Comparison of Experimental and Calculated Spin-Rotation and Electric Field Gradient Tensors

The high-resolution pure rotational spectrum of GaF has been measured using a Balle-Flygare-type Fourier transform spectrometer. Improved nuclear quadrupolar coupling constants and rotational constants have been obtained along with the first reported fluorine spin-rotation constant for gallium fluoride, C(I) ((69)Ga(19)F, v = 0) = +32.0(21) kHz. Accurate spin-rotation tensors from microwave or molecular beam spectroscopy are particularly important to NMR spectroscopists and theoreticians because these data provide information about anisotropic nuclear magnetic shielding in the absence of intermolecular effects. For quadrupolar nuclei such as gallium, the quadrupolar interaction is sufficiently large that it is very difficult to characterize shielding tensors directly via NMR spectroscopy. The experimentally determined nuclear quadrupolar coupling constants and spin-rotation constants for GaF are compared with the results of a series of high-level ab initio calculations carried out at various levels of theory with a range of basis sets. Further calculations on BF and AlF, supplemented with available experimental data for InF and TlF, allow for the investigation of trends in nuclear magnetic shielding, spin-rotation, and electric field gradient tensors in the group-13 fluorides. Calculations at the MP2/6-311++G** and MP2/6-311G(2df, 2pd) levels provide the most consistently satisfactory results in comparison with the experimental data. Copyright 2000 Academic Press.

Patterns of reflux and severity of varicose veins in the general population--Edinburgh Vein Study

OBJECTIVES

several studies have used duplex ultrasound to assess valvular incompetence in symptomatic patients. This cross-sectional survey was performed to determine, for the first time in a general population sample, the relationship between trunk varices and the presence of reflux in lower limb venous segments.

MATERIALS AND METHODS

1238 subjects (554 male, 684 female), aged 18-64 years, were randomly selected. The presence and severity of any trunk varices was assessed and classified into Grades 1-3; hyphenweb and reticular varices were noted. The presence or absence of reflux > or = 0.5 s in five deep and three superficial venous segments in each leg was assessed using duplex ultrasound.

RESULTS

the prevalence of reflux increased in both superficial and deep segments with more severe grades of trunk varices (p< or = 0.01), except the upper SFV in women. Fifteen per cent of females showed reflux confined to the superficial system, compared with 9% of males (p< or = 0.001); 22% of males showed deep reflux, compared with 11% of females (p < or = 0.001). 71% of men and 48% of women with Grade 2-3 trunk varices had mixed deep and superficial reflux. Above-knee popliteal segments had a higher prevalence of reflux than lower SFV segments in all groups. There was no consistent relationship between the presence of hyphenweb or reticular varices and deep or superficial reflux.

CONCLUSION

segmental venous reflux can be detected in the deep and superficial leg veins of subjects without trunk varices, but superficial and mixed reflux are increasingly found in subjects with more severe varices.

The relationship between lower limb symptoms and superficial and deep venous reflux on duplex ultrasonography: The Edinburgh Vein Study

BACKGROUND

Previous work from this group has demonstrated the relationships between lower limb symptoms and the presence and severity of trunk varicose veins as seen on clinical examination to be generally weak, symptom specific, and gender dependent.

OBJECTIVE

This study was undertaken to investigate the relationships in the general population between lower limb symptoms and the presence of superficial or deep venous reflux.

METHODS

A cross-sectional study was made of an age-stratified random sample of 1566 subjects (699 men and 867 women) aged 18 to 64 selected from 12 general practices in Edinburgh, Scotland. Subjects completed a self-administered questionnaire regarding symptoms (heaviness/tension, a feeling of swelling, aching, restless legs, cramps, itching, tingling) and underwent duplex ultrasound examination of the superficial and deep venous systems of both legs. Reflux of 0.5 seconds or greater was considered pathologic. Deep venous reflux was defined as reflux in at least the popliteal vein.

RESULTS

There was a significant positive relationship between isolated superficial reflux and the presence of heaviness/tension (P <.025, both legs) and itching (P =.002, left leg) in women. Isolated superficial reflux in men was not significantly positively associated with any symptom. Isolated deep venous reflux was not significantly related to any symptom in either leg in either sex. Combined reflux was related to a feeling of swelling (P =.018, right leg; P =.0022, left leg), cramps (P =.0049, left leg) and itching (P =.0043, left leg) in men, and aching (P =.03, right leg) and cramps (P =.026, left leg) in women.

CONCLUSION

In the general population, only certain lower limb symptoms were related to the presence of reflux on duplex ultrasound scanning. The strongest relationships were observed in the left legs of men with combined superficial and deep reflux.

Trends in case-fatality in 117 718 patients admitted with acute myocardial infarction in Scotland

OBJECTIVES

To analyse short- and long-term case-fatality trends following admission to hospital with a first acute myocardial infarction, in men and women between 1986 and 1995, after adjusting for risk factors known to influence survival.

DESIGN

A Scottish-wide retrospective cohort study.

SETTING

The Linked Scottish Morbidity Record Database was analysed. This contains accurate data on all hospital admissions since 1981, for the Scottish population of 5.1 million. It is linked to the Registrar General's death certificate data.

SUBJECTS

All 117 718 patients admitted to Scottish hospitals with a principal diagnosis of first acute myocardial infarction (ICD-9 code 410) between 1986 and 1995.

MAIN OUTCOME MEASURES

The outcome was death, both in and out of hospital, from any cause, at 30 days, 1 year, 5 and 10 years.

RESULTS

Overall case-fatality following hospital admission with acute myocardial infarction was 22. 2%, 31.4%, 51.1% and 64.0% at 1 month, 1 year, 5 and 10 years, respectively. Multivariate analyses identified statistically significant independent prognostic factors. Thirty day mortality increased twofold for each decade of increasing age, and increased with any prior admission to hospital. When comparing the most deprived category to that of the most affluent, men had a 10% increased mortality (P<0.01), whilst women had an increased mortality of 4% (not significant). After adjustment for age, sex, deprivation and prior admission to hospital, case-fatality rates fell significantly between 1986 and 1995. Short-term case-fatality fell by 46% in men (27% in women) and long-term by 34% in men (30% in women) (both P<0.001).

CONCLUSIONS

Population-based case-fatality rates in Scotland have fallen dramatically since 1986, particularly in men. The increasing survival in patients admitted to hospital suggests that the trial-based efficacy of modern therapies is now translating into population-based effectiveness. However, an individual's life expectancy still halves after a diagnosis of acute myocardial infarction. Of the variables that we could examine, age was the most powerful predictor of prognosis.

The Pure Rotational Spectra of AuCl and AuBr

The pure rotational spectra of AuCl and AuBr have been measured in the v = 0 and 1 (also for v = 2 for Au(35)Cl) vibrational states in the 5-22 GHz spectral region using a cavity pulsed-jet Fourier transform microwave spectrometer. The molecules were prepared by ablating Au metal in the presence of Cl(2) or Br(2) entrained in the Ar or Ne backing gas of the jet. The equilibrium internuclear distances r(e) have been determined along with estimates of the harmonic vibration frequencies and the dissociation energies. The ionic characters of the AuCl and AuBr bonds have been estimated from the halogen nuclear quadrupole-coupling constants to be i(c) approximately 38%. The gold nuclear quadrupole coupling constants change appreciably from AuF to AuCl to AuBr (including a sign change), indicating substantial differences in their electronic structures at Au; these variations could not be accounted for with a simple Townes-Dailey calculation. Copyright 2000 Academic Press.

Investigation and management of sporadic gastrointestinal infections with potentially Vero cytotoxin producing Escherichia coli in Scotland

Recognition of the potential of Escherichia coli O157 and other Vero cytotoxin producing E. coli (VTEC) organisms to cause serious disease led to the recommendation that all diarrhoeal stool specimens be examined for E. coli O157. National guidelines exist for the testing and exclusion of cases and contacts of VTEC infection. A survey was conducted to discover the extent to which these recommendations are followed in Scotland by asking about current practices for public health management of identified cases and laboratory investigation of E. coli infection. About two thirds of Scottish health boards followed national guidelines for testing and exclusion of cases and contacts of VTEC O157 infection. Most laboratories tested all diarrhoeal stools for E. coli O157 but detection methods varied and a minority tested selected stools for non-O157 E. coli serogroups. Standardisation of policies for laboratory testing of VTEC infection would improve national surveillance. Adherence to evidence based guidelines would standardise public health management of VTEC infections in Scotland.

Accurate measurement of exposure rate from a 60Co teletherapy source: deviations from the inverse-square law

A cylindrical gamma-ray 60Co source of activity alpha is predicted to produce an exposure rate X at a distance d in vacuum, given by X = gamma(T)(alpha/d2), where gamma(T) is the specific gamma-ray constant. It has been documented that this formula may be used to approximate X with an accuracy of 1% from a source of length l, provided that d/l > or = 5. It is shown that the formula is accurate to 0.1% under these conditions, provided that the distance is measured from the centre of the source. When absorption in the source and scattering in the collimator are considered, the position of the origin d = 0 can shift by a distance of the order of centimetres. Absorption in air between the source and the ionization chamber adds an exponential factor to the formula. It is shown that even when these modifications are included the discrepancy in the results, although generally less than 1%, is still large compared with the measurement errors. Some suggestions are made for the origin of this discrepancy.

The C. elegans apoptotic nuclease NUC-1 is related in sequence and activity to mammalian DNase II

The Caenorhabditis elegans nuc-1 gene has previously been implicated in programmed cell death due to the presence of persistent undegraded apoptotic DNA in nuc-1 mutant animals. In this report, we describe the cloning and characterization of nuc-1, which encodes an acidic nuclease with significant sequence similarity to mammalian DNase II. Database searches performed with human DNase II protein sequence revealed a significant similarity with the predicted C. elegans C07B5.5 ORF. Subsequent analysis of crude C. elegans protein extracts revealed that wild-type animals contained a potent endonuclease activity with a cleavage preference similar to DNase II, while nuc-1 mutant worms demonstrated a marked reduction in this nuclease activity. Sequence analysis of C07B5.5 DNA and mRNA also revealed that nuc-1(e1392), but not wild-type animals contained a nonsense mutation within the CO7B5.5 coding region. Furthermore, nuc-1 transgenic lines carrying the wild-type C07B5.5 locus demonstrated a complete complementation of the nuc-1 mutant phenotype. Our results therefore provide compelling evidence that the C07B5.5 gene encodes the NUC-1 apoptotic nuclease and that this nuclease is related in sequence and activity to DNase II.

Data collection methods in prospective economic evaluations: how accurate are the results?

OBJECTIVES

Often in economic evaluations a division is made between those studies that have a high level of accuracy versus those that are easily generalized. This interstudy dichotomy is often translated into prospective, randomized controlled trials with high internal validity and observational and modeling studies with a high level of external validity. This article challenges this conventional view and examines intrastudy effects on validity.

METHOD

A review and summary of the literature was conducted in order to assess the impact that data collection strategies will have on internal validity. Two scenario models were created in order to gain a preliminary understanding of the magnitude of the problem.

RESULTS

Data collection strategies have an impact on the level of internal validity found in an economic evaluation. Comparisons of studies that are prospective in nature is misleading as data collection strategy can lead to different resource and cost estimates even when all other relevant factors are similar. It is possible to shift and improve the level of validity by combining different collection methods.

CONCLUSIONS

Instead of viewing internal and external validity as polar opposites, validity should be considered in terms of a continuum within a particular study. The use of proxies to collect resource utilization estimates, the reliance on patient self-reported data, and the method of collecting this type of data all impact the validity of study results. National guidelines for the economic evaluation of agents and devices should consider this issue in more depth, and existing evidence rankings should be adapted to be more appropriate to pharmacoeconomic studies.

Use of Monte Carlo computation in benchmarking radiotherapy treatment planning system algorithms

Radiotherapy treatments are becoming more complex, often requiring the dose to be calculated in three dimensions and sometimes involving the application of non-coplanar beams. The ability of treatment planning systems to accurately calculate dose under a range of these and other irradiation conditions requires evaluation. Practical assessment of such arrangements can be problematical, especially when a heterogeneous medium is used. This work describes the use of Monte Carlo computation as a benchmarking tool to assess the dose distribution of external photon beam plans obtained in a simple heterogeneous phantom by several commercially available 3D and 2D treatment planning system algorithms. For comparison, practical measurements were undertaken using film dosimetry. The dose distributions were calculated for a variety of irradiation conditions designed to show the effects of surface obliquity, inhomogeneities and missing tissue above tangential beams. The results show maximum dose differences of 47% between some planning algorithms and film at a point 1 mm below a tangentially irradiated surface. Overall, the dose distribution obtained from film was most faithfully reproduced by the Monte Carlo N-Particle results illustrating the potential of Monte Carlo computation in evaluating treatment planning system algorithms.

Cloned delta-opioid receptors in GH(3) cells inhibit spontaneous Ca(2+) oscillations and prolactin release through K(IR) channel activation

Opioid receptors can couple to K(+) and Ca(2+) channels, adenylyl cyclase, and phosphatidyl inositol turnover. Any of these actions may be important in the regulation of neurotransmitter and hormone release from excitable cells. GH(3) cells exhibit spontaneous oscillations of intracellular Ca(2+) concentration ([Ca(2+)](i)) and prolactin release. Activation of cloned delta-opioid receptors stably expressed in GH(3) cells inhibits both spontaneous Ca(2+) signaling and basal prolactin release. The objective of this study was to examine a possible role for K(+) channels in these processes using the patch-clamp technique, fluorescence imaging, and a sensitive ELISA for prolactin. The selective delta receptor agonist [D-Pen(2), D-Pen(2)]enkephalin (DPDPE) inhibited [Ca(2+)](i) oscillations in GH(3) cells expressing both mu and delta receptors (GH(3)MORDOR cells) but had no effect on control GH(3) cells or cells expressing mu receptors alone (GH(3)MOR cells). The inhibition of [Ca(2+)](i) oscillations by DPDPE was unaffected by thapsigargin pretreatment, suggesting that this effect is independent of inositol 1,4,5-triphosphate-sensitive Ca(2+) stores. DPDPE caused a concentration-dependent inhibition of prolactin release from GH(3)MORDOR cells with an IC(50) of 4 nM. DPDPE increased inward K(+) current recorded from GH(3)MORDOR cells but had no significant effect on K(+) currents recorded from control GH(3) cells or GH(3)MOR cells. The mu receptor agonist morphine also had no effect on currents recorded from control cells but activated inward K(+) currents recorded from GH(3)MOR and GH(3)MORDOR cells. Somatostatin activated inward currents recorded from all three cell lines. The DPDPE-sensitive K(+) current was inwardly rectifying and was inhibited by Ba(2+) but not TEA. DPDPE had no effect on delayed rectifier-, Ca(2+)-, and voltage-activated or A-type K(+) currents, recorded from GH(3)MORDOR cells. Ba(2+) attenuated the inhibition of [Ca(2+)](i) and prolactin release by DPDPE, whereas TEA had no effect, consistent with an involvement of K(IR) channels in these actions of the opioid.

Assessment of background hydrogen by the Monte Carlo computer code MCNP-4A during measurements of total body nitrogen

The use of a hydrogen internal standard to enable the estimation of absolute mass during measurement of total body nitrogen by in vivo neutron activation is an established technique. Central to the technique is a determination of the H prompt gamma ray counts arising from the subject. In practice, interference counts from other sources--e.g., neutron shielding--are included. This study reports use of the Monte Carlo computer code, MCNP-4A, to investigate the interference counts arising from shielding both with and without a phantom containing a urea solution. Over a range of phantom size (depth 5 to 30 cm, width 20 to 40 cm), the counts arising from shielding increased by between 4% and 32% compared with the counts without a phantom. For any given depth, the counts increased approximately linearly with width. For any given width, there was little increase for depths exceeding 15 centimeters. The shielding counts comprised between 15% and 26% of those arising from the urea phantom. These results, although specific to the Swansea apparatus, suggest that extraneous hydrogen counts can be considerable and depend strongly on the subject's size.

Measuring the value of healthcare business assets

Healthcare organizations obtain valuations of business assets for many reasons, including to support decisions regarding potential mergers, sale of business components, or financing; for tax assessments; and for defense against law-suits. If compliance with regulations may be an issue, such as when a not-for-profit organization is involved in a transaction, healthcare organizations should seek an independent appraisal to ensure that applicable legal standards are met. Whether or not regulatory issues are involved, however, an accurate and useful valuation of business assets depends on many factors. Financial managers must understand the purpose and function of the valuation, choice of appropriate valuation techniques, proper assessment of intangible value, use of realistic growth rates, appropriate emphasis on key focus areas of the valuation (e.g., risk and future income streams), and an accounting of physician compensation.

Ligand-induced changes in surface mu-opioid receptor number: relationship to G protein activation?

In this study, we explored the relationship between regulation of surface mu-opioid receptor number, ligand-induced G protein activation (measured by [(35)]S]guanosine-5'-O-(3-thio)triphosphate (GTPgammaS) binding) and second messenger signaling (measured by the inhibition of cAMP accumulation). Etorphine and two isomers of cis-beta-hydroxy-3-methylfentanyl (RTI-1a and RTI-1b), which were full agonists for G protein activation and signaling, caused approximately a 50% loss of surface receptors after 1 h of treatment. Fentanyl and morphine were full agonists for inhibiting cAMP accumulation and partial agonists for stimulating [(35)S]GTPgammaS binding and internalization. Although both agonists were approximately 80% as efficacious as etorphine in stimulating [(35)S]GTPgammaS binding, fentanyl induced a 35% loss of surface receptors, whereas morphine only caused a 10% loss. Additionally, both long- and short-term treatment with the opioid antagonist naloxone caused increases in surface receptors. Unexpectedly, the weak partial agonists buprenorphine and one isomer of cis-beta-hydroxy-3-methylfentanyl (RTI-1d) also were found to cause an increase in surface receptors. Treatment with pertussis toxin (PTX) diminished agonist-induced loss of surface receptors. Furthermore, the abilities of morphine and fentanyl to cause internalization were more impaired after PTX treatment than that of etorphine. PTX treatment also significantly enhanced the increase in surface receptor number caused by 18-h treatment with naloxone and buprenorphine. The results of this study suggest that disruption of G protein coupling by PTX treatment affects ligand-regulated mu-receptor trafficking and that partial agonists for signaling can vary greatly in the ability to regulate the number of surface mu-opioid receptors.

Acoustic emission monitoring of high speed grinding of silicon nitride

Acoustic emission (AE) monitoring of a machining process offers real-time sensory input which could provide tool condition and part quality information that is critical to effective process control. However, the choice of sensor, its placement, and how to process the data and extract useful information are challenging application-specific questions which researchers must consider. Here we report an effort to resolve these questions for the case of high speed grinding of silicon nitride using an electroplated single-layered diamond wheel. A grinding experiment was conducted at a wheel speed of 149 m s-1 and continued until the end of the useful wheel life. AE signal data were then collected for each complete pass at given grinding times throughout the useful wheel life. We found that the amplitude of the AE signal monotonically increases with wheel wear, as do grinding forces and energy. Furthermore, the signal power contained in the AE signal proportionally increases with the associated grinding power, which suggests that the AE signal could provide quantitative information of wheel wear in high-speed grinding, and could also be used to determine when the grinding wheel needs replacement.

The Hyperfine Structures of ScCl and ScF

The Fourier transform microwave spectra of gaseous ScF and ScCl have been measured in their (1)Sigma(+) ground electronic states. Transitions have been observed for ScF (J = 1-0) and for both Sc(35)Cl and Sc(37)Cl (J = 1-0 and J = 2-1) in the ground vibrational state, and for Sc(35)Cl (J = 1-0 and J = 2-1) in the first excited vibrational state. The nuclear quadrupole coupling constants of Sc and of both isotopes of Cl, the spin-rotation constants for all the nuclei and the nuclear spin-nuclear spin constants for both molecules, have been determined. From these hyperfine constants, the electronic structures of ScF and ScCl have been investigated and comparisons have been made to similar molecules. ScCl has been found to be highly ionic. For Sc(35)Cl, the equilibrium bond length has been reevaluated and the vibration frequency and dissociation energy have been estimated. A simple approach to account for the Sc quadrupole coupling constants has been shown to be flawed. Copyright 2000 Academic Press.

The High-Resolution FTIR Far-Infrared Spectrum of Vinylamine

The infrared spectrum of vinylamine, generated by pyrolysis of cyclobutylamine, has been investigated at low and high resolution. The rovibrational structure of the far infrared spectrum (0.002 cm(-1)) has been analyzed, and effective rotational and centrifugal distortion constants have been derived for eight vibration-rotation bands in the region 250-750 cm(-1). The rovibrational structure of two further bands has been assigned using combination differences, and some conclusions have been drawn about the vibrational energy levels involved. With the large amount of new data it is possible to achieve a vibrational analysis of the far infrared region, but not to totally exclude an alternative assignment. Copyright 1999 Academic Press.

Vascular surgical society of great britain and ireland: symptoms of varicose veins

BACKGROUND: The relationships between varicose veins (VVs) and leg symptoms have not been studied. The aim of this study was to define the relationships between age, sex, leg symptoms and VVs. METHODS: An age-stratified sample of 699 men and 867 women aged 18-64 years, selected randomly from 12 general practices distributed socioeconomically throughout the city, completed a questionnaire regarding leg symptoms (heaviness/tension, swelling, aching, restless legs, cramps, itching, tingling) and underwent a clinical examination. RESULTS: In men, swelling and cramps (both P </= 0.001), and in women swelling (P = 0.02), restless legs (P = 0.001) and itching (P = 0.045), were significantly more common in older subjects. Data have therefore been age adjusted. Women were significantly (P < 0.01) more likely to respond positively when asked about all leg symptoms, except tingling. The commonest symptoms were aching in women (53.8 per cent) and cramps in men (34. 0 per cent). There was no difference between right and left legs. In men, only itching was significantly related to trunk VVs (P = 0.011). In women, there was a relationship between trunk VVs and heaviness/tension, aching and itching (P </= 0.005). Hyphen-web varices were not related to symptoms in men but were related to heaviness/tension and swelling in women. There was no association between reticular varices and symptoms in either sex. CONCLUSION: Even in the presence of VVs, most lower limb 'venous' symptoms are non-venous in aetiology. Surgery is unlikely to ameliorate symptoms in the majority of patients.

An MCNP-based model of a linear accelerator x-ray beam

The Monte Carlo N-Particle radiation transport computer code (MCNP) has been employed on a personal computer to develop a simple model simulating the major components within the beam path of a linear accelerator radiation head, namely the electron target, primary conical collimator, beam flattening filter, wedge filter and the secondary collimators. The model was initially used to calculate the energy spectra and angular distributions of the x-ray beam for the Philips SL 75/5 linear accelerator, in a plane immediately beneath the flattening filter. These data were subsequently used as a 'source' of x-rays at the target position, to assess the emergent beam from the secondary collimators. The depth dose distributions and dose profiles at constant depth for various field sizes have been calculated for a nominal operating potential of 4 MV and found to be within acceptable limits. It is concluded that the technique may be used to calculate the energy spectra of any linear accelerator upon specification of the component dimensions, materials and nominal accelerating potential. It is anticipated that this work will serve as the basis of a quality control tool for linear accelerators and treatment planning systems.

L-type Ca2+ channels and K+ channels specifically modulate the frequency and amplitude of spontaneous Ca2+ oscillations and have distinct roles in prolactin release in GH3 cells

GH3 cells showed spontaneous rhythmic oscillations in intracellular calcium concentration ([Ca2+]i) and spontaneous prolactin release. The L-type Ca2+ channel inhibitor nimodipine reduced the frequency of Ca2+ oscillations at lower concentrations (100nM-1 microM), whereas at higher concentrations (10 microM), it completely abolished them. Ca2+ oscillations persisted following exposure to thapsigargin, indicating that inositol 1,4,5-trisphosphate-sensitive intracellular Ca2+ stores were not required for spontaneous activity. The K+ channel inhibitors Ba2+, Cs+, and tetraethylammonium (TEA) had distinct effects on different K+ currents, as well as on Ca2+ oscillations and prolactin release. Cs+ inhibited the inward rectifier K+ current (KIR) and increased the frequency of Ca2+ oscillations. TEA inhibited outward K+ currents activated at voltages above -40 mV (grouped within the category of Ca2+ and voltage-activated currents, KCa,V) and increased the amplitude of Ca2+ oscillations. Ba2+ inhibited both KIR and KCa,V and increased both the amplitude and the frequency of Ca2+ oscillations. Prolactin release was increased by Ba2+ and Cs+ but not by TEA. These results indicate that L-type Ca2+ channels and KIR channels modulate the frequency of Ca2+ oscillations and prolactin release, whereas TEA-sensitive KCa,V channels modulate the amplitude of Ca2+ oscillations without altering prolactin release. Differential regulation of these channels can produce frequency or amplitude modulation of calcium signaling that stimulates specific pituitary cell functions.

Prevalence of varicose veins and chronic venous insufficiency in men and women in the general population: Edinburgh Vein Study

STUDY OBJECTIVE

To determine the prevalence of varicose veins and chronic venous insufficiency (CVI) in the general population.

DESIGN

Cross sectional survey.

SETTING

City of Edinburgh.

PARTICIPANTS

Men and women aged 18-64 years selected randomly from age-sex registers of 12 general practices.

MAIN RESULTS

In 1566 subjects examined, the age adjusted prevalence of trunk varices was 40% in men and 32% in women (p < or = 0.01). This sex difference was mostly a result of higher prevalence of mild trunk varices in men. More than 80% of all subjects had mild hyphenweb and reticular varices. The age adjusted prevalence of CVI was 9% in men and 7% in women (p < or = 0.05). The prevalence of all categories of varices and of CVI increased with age (p < or = 0.001). No relation was found with social class.

CONCLUSIONS

Approximately one third of men and women aged 18-64 years had trunk varices. In contrast with the findings in most previous studies, mainly conducted in the 1960s and 1970s, chronic venous insufficiency and mild varicose veins were more common in men than women. No evidence of bias in the study was found to account for this sex difference. Changes in lifestyle or other factors might be contributing to an alteration in the epidemiology of venous disease.

The High-Resolution FTIR Far-Infrared Spectrum of Formamide

The far-infrared spectrum of formamide (HCONH2) has been recorded at high resolution and over 9000 vibration-rotation lines assigned. Molecular parameters from the rovibrational analyses of the unperturbed 12(1)0 out-of-plane vibration band have been obtained for the ground state and the excited state. An analysis of the complicated resonance system between the 9(1)0, 11(1)0, and 12(2)0 bands has also been carried out. The mid-infrared spectrum of formamide has been recorded at low resolution and assignments for the fundamental, combination, and overtone bands in this region are given. The Large Amplitude Motion (LAM) of the out-of-plane mode has been reanalyzed using the new parameter set. Copyright 1999 Academic Press.

A survey of mental health consumers' and family members' involvement in advocacy

As the service delivery system is redesigned, the involvement of consumers and family members in mental health policy-making is essential. Advocacy is a way for them to have an impact on policy or decision-making. To determine the extent of their participation in advocacy efforts, consumers and family members were surveyed by other consumers and family members about their involvement in advocacy and mental healthcare reform. Although more family than consumers reported receiving mental healthcare reform information, both groups had difficulty understanding this information. Consumers were more likely to have received information from a mental health professional while family were more likely to have received information from an advocacy group. Lack of economic resources and communication problems were the most often cited barriers to advocacy for consumers. Strategies are suggested for how to increase involvement of consumers and family in advocacy efforts. The limitations of conducting a state-wide study with consumers and family as data collectors is discussed.

Prevalence of venous reflux in the general population on duplex scanning: the Edinburgh vein study

PURPOSE

The prevalence of reflux in the deep and superficial venous systems in the Edinburgh population and the relationship between patterns of reflux and the presence of venous disease on clinical examination were studied.

METHODS

A cross-sectional survey was done on men and women ranging in age from 18 to 64 years, randomly selected from 12 general practices. The presence of varicose veins and chronic venous insufficiency was noted on clinical examination, as was the duration of venous reflux by means of duplex scanning in 8 vein segments on each leg. Results were compared using cut-off points for reflux duration (RD) of 0.5 seconds or more (RD >/= 0.5) and more than 1.0 second (RD > 1.0) to define reflux.

RESULTS

There were 1566 study participants, 867 women and 699 men. The prevalence of reflux was similar in the right and left legs. The proportion of participants with reflux was highest in the lower thigh long saphenous vein (LSV) segment (18.6% in the right leg and 17.5% in the left leg for RD >/= 0.5), followed by the above knee popliteal segments (12.3% in the right leg and 11.0% in the left leg for RD >/= 0.5), the below knee popliteal (11.3% in the right leg and 9.5% in the left leg for RD >/= 0.5), upper LSV (10.0% in the right leg and 10.8% in the left leg for RD >/= 0.5) segments, the common femoral vein segments (7.8% in the right leg and 8.0% in the left leg for RD >/= 0.5), the lower superficial femoral vein (SFV) segments (6.6% in the right leg and 6.4% in the left leg for RD >/= 0.5), and the upper SFV (5.2% in the right leg and 4.7% in the left leg for RD >/= 0.5) and short saphenous vein (SSV) (4.6% in the right leg and 5.6% in the left leg for an RD >/= 0.5) segments. In the superficial vein segments, there was little difference in the occurrence of reflux whether RD >/= 0.5 or RD > 1.0 was used; but in the different deep vein segments, the prevalence of reflux was 2 to 4 times greater for RD >/= 0.5 rather than RD > 1.0. Men had a higher prevalence of reflux in the deep vein segments than women, reaching statistical significance (P </=.01) in 4 of 5 segments for RD >/= 0.5. In general, the prevalence of reflux increased with age. Those with "venous disease" had a significantly higher prevalence of reflux in all vein segments than those with "no disease" (P </=.001).

CONCLUSION

The prevalence of venous reflux in the general population was related to the presence of "venous disease," although it was also present in those without clinically apparent disease. There was a higher prevalence of reflux in the deep veins in men than the deep veins in women. Follow-up study of the population will determine the extent to which reflux is a predictor of future disease and complications.

ORL-1 and mu opioid receptor antisera label different fibers in areas involved in pain processing

Mu opioid receptors (MOR) mediate the analgesic effects of opioid drugs such as morphine. The opioid receptor-like (ORL-1) receptor is structurally related to opioid receptors and the ORL-1 receptor agonist, orphanin FQ/nociceptin, induces analgesia at the spinal level, but appears to recruit different circuitry than that used by mu opioids. When administered intracerebroventricularly, orphanin FQ/nociceptin produces hyperalgesia and/or reverses opioid analgesia. The functionally distinct actions elicited by MOR and ORL-1 receptors, which activate similar intracellular signaling systems and show similar regional distributions, could be explained by their differential cellular localization. By using double label immunohistochemistry and confocal microscopy, the present study investigates the distribution of MOR and ORL-1 receptors in regions of the rat nervous system that are involved with nociceptive processing. In general co-localization of MOR and ORL-1 receptor immunoreactivity was not observed in either perikarya or neuropil in the dorsal root ganglia, nor in the Lissauer's tract and superficial laminae of the spinal cord. Likewise, there was no evidence for co-localization of these receptors within the periaqueductal gray, the nucleus raphe magnus, the gigantocellular reticular nucleus, and the nucleus of the solitary tract. These observations indicate that MOR and ORL-1 receptors are expressed predominantly on different fiber systems in these regions. This differential distribution is consistent with the distinct pharmacology of ORL-1 and MOR receptor agonists and suggests that the antisera to MOR and ORL-1 receptors may provide useful markers for further investigations of analgesic and counteranalgesic pathways modulating pain perception.

Phosphorylation is not required for dynamin-dependent endocytosis of a truncated mutant opioid receptor

Opioid receptors are regulated within minutes after activation by G protein-coupled receptor kinase-mediated phosphorylation and dynamin-dependent endocytosis. We addressed the question of whether phosphorylation is required for opioid receptor endocytosis by examining a functional, truncated mutant delta opioid receptor (DOR344T), which is missing phosphorylation sites located in the carboxyl-terminal cytoplasmic domain. DOR344T receptors expressed in Chinese hamster ovary cells remained predominantly in the plasma membrane, even in the presence of saturating concentrations of agonist, consistent with previous studies demonstrating strongly inhibited endocytosis of truncated receptors in this cell type. In marked contrast, DOR344T receptors expressed at similar levels in human embryonal kidney (HEK) 293 cells exhibited rapid, ligand-induced internalization either in the presence of peptide (DADLE) or alkaloid (etorphine) agonist. Quantitative assays using ELISA and flow cytometric techniques indicated that DOR344T receptors were endocytosed in HEK293 cells with similarly rapid kinetics as full-length DOR (t1/2 < 10 min), and both full-length DOR and DOR344T mutant receptors were endocytosed by a dynamin-dependent mechanism involving clathrin-coated pits. Nevertheless, DOR344T receptors failed to undergo any detectable constitutive or agonist-induced phosphorylation in the same cells in which dynamin-dependent endocytosis was observed. These findings establish the first example of a G protein-coupled receptor that does not require phosphorylation to undergo dynamin-dependent endocytosis, and they suggest that significant cell type-specific differences exist in the biochemical requirements for ligand-induced concentration of opioid receptors in clathrin-coated pits.

Pixel-based absolute topography test for three flats

We demonstrate a method of performing the absolute three-flat test by using reflection symmetries of the surfaces and an algorithm for generating the rotation of arrays of pixel data. Most of the operations involve left/right and top/bottom flips of data arrays, operations that are very fast on most frame grabbers and are available on most commercial phase-measuring interferometers. We demonstrate the method with simulated data as well as with actual data from 150-mm-diameter surfaces that are flat to less than 25 nm peak to valley.

Quantitative immunolocalization of mu opioid receptors: regulation by naltrexone

The present study utilized a newly developed quantitative immunohistochemical assay to measure changes in mu opioid receptor abundance following chronic administration of the opioid receptor antagonist naltrexone. These data were compared with those obtained from mu receptor radioligand binding on adjacent tissue sections, in order to determine whether the characteristic antagonist-induced increase in radioligand binding is due to an increase in the total number of mu receptors and/or to an increase in the proportion of receptors that are in an active binding conformation in the absence of a change in the total number of receptors. Adult male Sprague-Dawley rats were administered naltrexone, 7-8 mg/kg per day, or saline continuously for seven days by osmotic minipumps, after which time their brains were processed for immunohistochemistry and receptor autoradiography on adjacent fresh frozen tissue sections. Semiquantitative immunohistochemistry was performed using a radiolabelled secondary antibody for autoradiographic determination and a set of radioactive standards. Results demonstrate an overall concordance between the distribution of mu opioid receptors as measured by the two different methods with a few exceptions. Following naltrexone administration, mu receptor immunoreactivity was significantly higher in the amygdala, thalamus, hippocampus, and interpeduncular nucleus as compared with the saline-treated control animals. [3H]D-Ala2,N-Me-Phe4,Gly-ol5-enkephalin binding to mu opioid receptors was significantly higher in the globus pallidus, amygdala, thalamus, hypothalamus, hippocampus, substantia nigra, ventral tegmental area, central gray, and interpeduncular nucleus of the naltrexone-treated rats. These findings indicate that in some brain regions chronic naltrexone exposure increases the total number of mu opioid receptors, while in other regions there is an increase in the percent of active receptors without an observable change in the total number of receptors. Quantitative receptor immunodetection together with ligand autoradiography provides a new approach for investigating the regulation of mu opioid receptors on tissue sections.

The elemental analysis of the human body using associated particle timing based on the D + D reaction

Fast (approximately 2.8 MeV) neutrons are generated in the 2H(d,n)3He reaction, and are used for excitation of sample materials via inelastic scattering. Nanosecond timing identifies the spatial origin of the measured gamma radiation, making possible three-dimensional imaging and improved detection sensitivity. Several elements have been measured, and it is estimated that a clinical device, with equivalent dose of 10 mSv, will be capable of detecting the order of 10-100 mg.

A new Monte Carlo program for computing low-energy gamma- and X-ray propagation in an axially-symmetric XRF system. Swansea In Vivo Analysis and Cancer (SIVAC) Group

Annular XRF systems, using backscattering geometry, have advantages of convenience of use, but it is difficult to predict their sensitivity to concentrations of heavy metals ta different depths, or the contribution of scattered radiation to the background. A Monte Carlo program has therefore been developed to carry out calculations of this type. Several variance-reduction techniques are included. Preliminary results for the detection of platinum are given.

Changes in body fat: measurements by neutron activation, densitometry and dual energy X-ray absorptiometry

The measurement of body fat in ten subjects (BMI from 22 to 43 kg/m2), and in particular the changes arising from a ketogenic diet, by the techniques of in vivo neutron activation analysis (NAA), densitometry (using two- and four-compartment models) by under water weighing (UWW) and dual energy X-ray absorptiometry (DXA) was compared. The association between techniques for the fat changes was generally high (r = 0.70 to 0.98) and significant (p < 0.05). Assessment of agreement between DXA and the other techniques revealed discrepancies with significant slope and high association (r = -0.81 and -0.64). Whilst NAA and UWW appeared to measure similar changes, DXA underestimated small changes.

Body composition measurements using DXA and other techniques in tamoxifen-treated patients

Tamoxifen is an anti-oestrogenic drug which is widely used in the treatment of patients with breast cancer. There is increasing interest in using the drug both for benign breast disease and as a chemo-preventative agent of the drug in women at high risk of breast cancer. Despite the fact that the acute side-effects of the drug are few, its agonistic and antagonistic oestrogenic effects are not fully known and may have some undesirable effects for patients treated with the drug for several years. A number of studies carried out recently indicate a varying degree of change in bone mineral content following treatment with tamoxifen. These studies concentrated mainly on bone mineral density measurements only and non of them reported the effects of tamoxifen on lean body mass and fat mass. In this study we measured lean body mass and fat mass in tamoxifen-treated females and a comparison group to determine the difference between the two groups. Twenty-six women receiving tamoxifen (20 mg/d) have participated in this study. The control group comprised 31 healthy women of a similar age. Total body bone mineral (TBBM) was measured using a dual-energy X-ray absorptiometry (DXA) (Hologic INV., Waltham, U.S.A.). Similarly, regional and total body soft tissue (lean and fat tissue) were measured using the DXA system. In addition to DXA measurements, percentage body fat (%BF) was measured using total body potassium counting (TBK), skinfold anthropometry (SF), infrared interactance (i.r.) and bioelectric impedance analysis (BIA). Results from DXA alone showed that there were no significant differences between the two groups for TBBM, regional and total body lean tissue mass. However, there was a significant difference between the two groups (P < 0.05) for %BF measurement. Similarly there was a significant difference between the two groups (P < 0.05) for %BF measured by other body composition techniques. Although there is no other research reported on the effects of tamoxifen on %BF, this retrospective study indicates that tamoxifen may lead to increase in fact content in women who are subjected to this treatment. We conclude that this observation is probably related to the agonistic oestrogenic effect of Tamoxifen on body fat. To our knowledge this deleterious effect has not been reported before and it should be taken into considerable when comprising different types of anti-oestrogenic drugs. Furthermore, patients should be warned about this side-effect when they are prescribed Tamoxifen therapy.

Monte Carlo simulation of prompt gamma neutron activation analysis using MCNP code

Prompt gamma neutron activation analysis (PGNAA) is the most direct method of measuring total-body nitrogen. In combination with internal hydrogen standardisation, it is possible to reduce the dependence on body habitus. The uniformity of activation and detection, however, cannot be optimised sufficiently to eliminate the dependence entirely, and so further corrections are essential. The availability of the powerful Monte Carlo code MCNP(4A) has allowed a more accurate analysis of the activation facility, and yields corrections for body habitus and superficial fat layers. The accuracy of the correction is retained as the source-to-skin distance is reduced, although the activation uniformity is thereby degraded. This allows the use of a 252Cf source with lower activity and hence reduces the running cost of the facility.

mu-Opioid receptor internalization: opiate drugs have differential effects on a conserved endocytic mechanism in vitro and in the mammalian brain

mu-Opioid receptors are the pharmacological targets of endogenous opioid peptides and morphine-like alkaloid drugs. Previous studies of transfected cells and peripheral neurons indicate that opioid receptors are rapidly internalized after activation by the alkaloid agonist etorphine but not after activation by morphine. To determine whether opioid receptors in the central nervous system are regulated by a similar process of agonist-selective internalization, mu-opioid receptors were examined in rat brain neurons after treatment of animals with opioid drugs. Internalized mu receptors were observed within 30 min after intraperitoneal injection of the alkaloid agonist etorphine, and this process was blocked by the antagonist naloxone. Colocalization of internalized opioid receptors with transferrin receptors in confocal optical sections indicated that receptor internalization observed in vivo is mediated by a membrane trafficking pathway similar to that observed previously in vitro using transfected human embryonic kidney 293 cells. Morphine failed to induce detectable rapid internalization of receptors, even when administered to animals at doses far in excess of those required to induce analgesia. To quantify these agonist-selective differences and to analyze an array of opioid ligands for their ability to trigger internalization, we used flow cytometry on stably transfected 293 cells. These studies indicated that the different effects of individual agonists are not correlated with their potencies for receptor activation and that a variety of clinically important agonists differ significantly in their relative abilities to stimulate the rapid internalization of opioid receptors.

Alterations in K+ evoked profiles of neurotransmitter and neuromodulator amino acids after focal ischemia-reperfusion

Secondary elevations in extracellular amino acids occur during reperfusion after transient cerebral ischemia. The delayed accumulation of excitatory amino acids may contribute to the progressive development of neuronal injury. In this study, we explored the mechanisms that may be involved in this phenomenon. Microdialysis samples from probes located in rabbit cortex were analysed with a chiral amino acid procedure. Concentrations of neurotransmitters (L-Glu, GABA), N-methyl-D-aspartate receptor modulators (D-Ser, Gly), an inhibitory neuromodulator (Tau), the lipid component phosphoethanolamine, and L-Gln, L-Ser and L-Ala were measured. Depolarization via perfusion with potassium was used to assess the status of release/reuptake systems at 2 and 4 h reperfusion after 2 h transient focal ischemia. Background experiments classified potassium evoked responses as calcium dependent or calcium-independent by inclusion of 30 microM omega-conopeptide MVIIC or by inclusion of 20 mM magnesium and ommision of calcium. During ischemia, large elevations of almost all amino acids occurred. During reperfusion, secondary elevations in transmitter amino acids (L-Glu, GABA) and N-methyl-D-aspartate receptor modulators (D-Ser, Gly) occurred. Tau remained slightly elevated whereas the lipid component phosphoethanolamine remained high and stable during reperfusion. Reperfusion significantly potentiated the potassium response for amino acids with calcium-dependent responses (L-Glu and GABA). In contrast, calcium-independent responses (Tau, phosphoethanolamine, L-Gln) were significantly attenuated. Intermediate behavior was observed with Gly, while no potassium responses were observed for D-Ser, L-Ser or L-Ala. These data demonstrate that perturbations in evoked amino acid profiles after ischemia-reperfusion are selective. Reduction of calcium-independent responses implicate a general decline in efficacy of transporter mechanisms that restore transmembrane gradients of ions and transmitters. Decreased efficacy of transporter systems may reduce transmitter reuptake and account for the amplified release of L-Glu and GABA, thus contributing to progressive neural dysfunction after cerebral ischemia.

Collaboration between a state alliance for the mentally ill and a state mental health authority in monitoring the consequences of downsizing

As consumers are released from hospitalization as a result of the downsizing of inpatient psychiatric facilities, their ability to sustain themselves in the community becomes a concern to a number of constituencies. This article describes the development of a program for monitoring persons who were released from hospitals into the community as a result of the downsizing of state psychiatric hospitals. The program's uniqueness was the collaboration between the state mental health authority and the state Alliance for the Mentally Ill in developing and implementing the monitoring system.

High-Resolution Fourier Transform Infrared Spectroscopy of Nitrosyl Fluoride

The high-resolution FTIR spectrum of FNO has been recorded and the rovibrational structure of the essentially unperturbed nu3, 2nu3, and nu1 + nu3 cold bands and the 2nu3 <-- nu3, nu2 + nu3 <-- nu3, and nu1 + nu2 + nu3 <-- nu3 hot bands has been analyzed. The perturbed bands nu1 and nu1 + nu2 have been assigned and the data analyzed by fitting the transitions with the dark states nu2 + 2nu3 and 2nu2 + 2nu3. Parameters for both light and dark states together with Coriolis coupling parameters have been determined. Copyright 1998 Academic Press. Copyright 1998Academic Press