Pharmacological and safety profile of a prolonged-release lanreotide formulation in acromegaly

BACKGROUND

Patients with acromegaly require lifelong medication; a longer dosing interval would reduce treatment burden. This study investigated the pharmacokinetics, pharmacodynamics and safety profile of a new prolonged-release formulation (PRF) of lanreotide every 12 weeks.

RESEARCH DESIGN AND METHODS

In this multicenter, open-label, dose-ascending study, cohorts of nine patients with acromegaly received single doses of lanreotide PRF according to a 3 + 3 + 3 scheme in order to determine the maximum tolerated dose (MTD). Following a 12-week treatment period, patients were followed up for a further 12 weeks. Serum lanreotide, insulin-like growth factor-1 and growth hormone concentrations were analyzed. Adverse events were monitored throughout the study.

RESULTS

The MTD was not reached. Peak lanreotide serum concentration values were similar in all cohorts, whereas area under the curve values from time zero to 85 days increased but were not dose-proportional. The apparent elimination half-life of lanreotide PRF was approximately 54-63 days, in line with the expected prolonged-release characteristics. Growth hormone and insulin-like growth factor-1 levels were generally stable.

CONCLUSIONS

The safety and tolerability profile was in-line with the known safety profile of lanreotide autogel. Lanreotide PRF was well tolerated and the pharmacokinetic profile suggests that a dosing interval of 12 weeks could be achievable.

CLINICAL TRIAL REGISTRATION

www.clinicaltrials.gov identifier is NCT02396953; EudraCT 2014-002389-62.

Coronary Artery Disease Phenotype Detection in an Academic Hospital System Setting

BACKGROUND

The United States, and especially West Virginia, have a tremendous burden of coronary artery disease (CAD). Undiagnosed familial hypercholesterolemia (FH) is an important factor for CAD in the U.S. Identification of a CAD phenotype is an initial step to find families with FH.

OBJECTIVE

We hypothesized that a CAD phenotype detection algorithm that uses discrete data elements from electronic health records (EHRs) can be validated from EHR information housed in a data repository.

METHODS

We developed an algorithm to detect a CAD phenotype which searched through discrete data elements, such as diagnosis, problem lists, medical history, billing, and procedure (International Classification of Diseases [ICD]-9/10 and Current Procedural Terminology [CPT]) codes. The algorithm was applied to two cohorts of 500 patients, each with varying characteristics. The second (younger) cohort consisted of parents from a school child screening program. We then determined which patients had CAD by systematic, blinded review of EHRs. Following this, we revised the algorithm by refining the acceptable diagnoses and procedures. We ran the second algorithm on the same cohorts and determined the accuracy of the modification.

RESULTS

CAD phenotype Algorithm I was 89.6% accurate, 94.6% sensitive, and 85.6% specific for group 1. After revising the algorithm (denoted CAD Algorithm II) and applying it to the same groups 1 and 2, sensitivity 98.2%, specificity 87.8%, and accuracy 92.4; accuracy 93% for group 2. Group 1 F1 score was 92.4%. Specific ICD-10 and CPT codes such as "coronary angiography through a vein graft" were more useful than generic terms.

CONCLUSION

We have created an algorithm, CAD Algorithm II, that detects CAD on a large scale with high accuracy and sensitivity (recall). It has proven useful among varied patient populations. Use of this algorithm can extend to monitor a registry of patients in an EHR and/or to identify a group such as those with likely FH.

Npas4 Is a Critical Regulator of Learning-Induced Plasticity at Mossy Fiber-CA3 Synapses during Contextual Memory Formation

Synaptic connections between hippocampal mossy fibers (MFs) and CA3 pyramidal neurons are essential for contextual memory encoding, but the molecular mechanisms regulating MF-CA3 synapses during memory formation and the exact nature of this regulation are poorly understood. Here we report that the activity-dependent transcription factor Npas4 selectively regulates the structure and strength of MF-CA3 synapses by restricting the number of their functional synaptic contacts without affecting the other synaptic inputs onto CA3 pyramidal neurons. Using an activity-dependent reporter, we identified CA3 pyramidal cells that were activated by contextual learning and found that MF inputs on these cells were selectively strengthened. Deletion of Npas4 prevented both contextual memory formation and this learning-induced synaptic modification. We further show that Npas4 regulates MF-CA3 synapses by controlling the expression of the polo-like kinase Plk2. Thus, Npas4 is a critical regulator of experience-dependent, structural, and functional plasticity at MF-CA3 synapses during contextual memory formation.

A joint ERS/ATS policy statement: what constitutes an adverse health effect of air pollution? An analytical framework

The American Thoracic Society has previously published statements on what constitutes an adverse effect on health of air pollution in 1985 and 2000. We set out to update and broaden these past statements that focused primarily on effects on the respiratory system. Since then, many studies have documented effects of air pollution on other organ systems, such as on the cardiovascular and central nervous systems. In addition, many new biomarkers of effects have been developed and applied in air pollution studies.This current report seeks to integrate the latest science into a general framework for interpreting the adversity of the human health effects of air pollution. Rather than trying to provide a catalogue of what is and what is not an adverse effect of air pollution, we propose a set of considerations that can be applied in forming judgments of the adversity of not only currently documented, but also emerging and future effects of air pollution on human health. These considerations are illustrated by the inclusion of examples for different types of health effects of air pollution.

The LCLS variable-energy hard X-ray single-shot spectrometer

The engineering design, implementation, operation and performance of the new variable-energy hard X-ray single-shot spectrometer (HXSSS) for the LCLS free-electron laser (FEL) are reported. The HXSSS system is based on a cylindrically bent Si thin crystal for dispersing the incident polychromatic FEL beam. A spatially resolved detector system consisting of a Ce:YAG X-ray scintillator screen, an optical imaging system and a low-noise pixelated optical camera is used to record the spectrograph. The HXSSS provides single-shot spectrum measurements for users whose experiments depend critically on the knowledge of the self-amplified spontaneous emission FEL spectrum. It also helps accelerator physicists for the continuing studies and optimization of self-seeding, various improved mechanisms for lasing mechanisms, and FEL performance improvements. The designed operating energy range of the HXSSS is from 4 to 20 keV, with the spectral range of order larger than 2% and a spectral resolution of 2 × 10(-5) or better. Those performance goals have all been achieved during the commissioning of the HXSSS.

Cardiorespiratory biomarker responses in healthy young adults to drastic air quality changes surrounding the 2008 Beijing Olympics

Associations between air pollution and cardiorespiratory mortality and morbidity have been well established, but data to support biologic mechanisms underlying these associations are limited. We designed this study to examine several prominently hypothesized mechanisms by assessing Beijing residents' biologic responses, at the biomarker level, to drastic changes in air quality brought about by unprecedented air pollution control measures implemented during the 2008 Beijing Olympics. To test the hypothesis that changes in air pollution levels are associated with changes in biomarker levels reflecting inflammation, hemostasis, oxidative stress, and autonomic tone, we recruited and retained 125 nonsmoking adults (19 to 33 years old) free of cardiorespiratory and other chronic diseases. Using the combination of a quasi-experimental design and a panel-study approach, we measured biomarkers of autonomic dysfunction (heart rate [HR*] and heart rate variability [HRV]), of systemic inflammation and oxidative stress (plasma C-reactive protein [CRP], fibrinogen, blood cell counts and differentials, and urinary 8-hydroxy-2'-deoxyguanosine [8-OHdG]), of pulmonary inflammation and oxidative stress (fractional exhaled nitric oxide [FeNO], exhaled breath condensate [EBC] pH, EBC nitrate, EBC nitrite, EBC nitrite+nitrate [sum of the concentrations of nitrite and nitrate], and EBC 8-isoprostane), of hemostasis (platelet activation [plasma sCD62P and sCD40L], platelet aggregation, and von Willebrand factor [vWF]), and of blood pressure (systolic blood pressure [SBP] and diastolic blood pressure [DBP]). These biomarkers were measured on each subject twice before, twice during, and twice after the Beijing Olympics. For each subject, repeated measurements were separated by at least one week to avoid potential residual effects from a prior measurement. We measured a large suite of air pollutants (PM2.5 [particulate matter < or = 2.5 microm in aerodynamic diameter] and constituents, sulfur dioxide [SO2], carbon monoxide [CO], nitrogen dioxide [NO2], and ozone [O3]) throughout the study at a central Beijing site near the residences and workplaces of the subjects on a daily basis. Total particle number (TPN) was also measured at a separate site. We used a time-series analysis to assess changes in pollutant concentration by period (pre-, during-, and post-Olympics periods). We used mixed-effects models to assess changes in biomarker levels by period and to estimate changes associated with increases in pollutant concentrations, controlling for ambient temperature, relative humidity (RH), sex, and the day of the week of the biomarker measurements. We conducted sensitivity analyses to assess the impact of potential temporal confounding and exposure misclassification. We observed reductions in mean concentrations for all measured pollutants except O3 from the pre-Olympics period to the during-Olympics period. On average, elemental carbon (EC) changed by -36%, TPN by -22%, SO2 by -60%, CO by -48%, and NO2 by -43% (P < 0.05 for all these pollutants). Reductions were observed in mean concentrations of PM2.5 (by -27%), sulfate (SO4(2-)) (by -13%), and organic carbon (OC) (by -23%); however, these values were not statistically significant. Both 24-hour averages and 1-hour maximums of O3 increased (by 20% and 17%, respectively) from the pre-Olympics to the during-Olympics period. In the post-Olympics period after the pollution control measures were relaxed, mean concentrations of most pollutants (with the exception of SO4(2-) and O3) increased to levels similar to or higher than pre-Olympics levels. Concomitantly and consistent with the hypothesis, we observed, from the pre-Olympics to the during-Olympics period, statistically significant (P < or = 0.05) or marginally significant (0.05 < P < 0.1) decreases in HR (-1 bpm or -1.7% [95% CI, -3.4 to -0.1]), SBP (-1.6 mmHg or -1.8% [95% CI, -3.9 to 0.4]), 8-OHdG (-58.3% [95% CI, -72.5 to -36.7]), FeNO (-60.3% [95% CI, -66.0 to -53.6]), EBC nitrite (-30.0% [95% CI, -39.3 to -19.3]), EBC nitrate (-21.5% [95% CI, -35.5 to -4.5]), EBC nitrite+nitrate (-17.6% [95% CI, -28.4 to -5.1]), EBC hydrogen ions (-46% [calculated from EBC pH], or +3.5% in EBC pH [95% CI, 2.2 to 4.9]), sCD62P (-34% [95% CI, -38.4 to -29.2]), sCD40L (-5.7% [95% CI, -10.5 to -0.7]), and vWF (-13.1% [95% CI, -18.6 to -7.5]). Moreover, the percentages of above-detection values out of all observations were significantly lower for plasma CRP and EBC 8-isoprostane in the during-Olympics period compared with the pre-Olympics period. In the post-Olympics period, the levels of the following biomarkers reversed (increased, either with or without statistical significance) from those in the during-Olympics period: SBP (10.7% [95% CI, 2.8 to 18.6]), fibrinogen (4.3% [95% CI, -1.7 to 10.2), neutrophil count (4.7% [95% CI, -7.7 to 17.0]), 8-OHdG (315% [95% CI, 62.0 to 962]), FeNO (130% [95% CI, 62.5 to 225]), EBC nitrite (159% [95% CI, 71.8 to 292]), EBC nitrate (161% [95% CI, 48.0 to 362]), EBC nitrite+nitrate (124% [95% CI, 50.9 to 233]), EBC hydrogen ions (146% [calculated from EBC pH] or -4.8% in EBC pH [95% CI, -9.4 to -0.21), sCD62P (33.7% [95% CI, 17.7 to 51.8]), and sCD40L (9.1% [95% CI, -3.7 to 23.5]). Furthermore, these biomarkers also showed statistically significant associations with multiple pollutants across different lags after adjusting for meteorologic parameters. The associations were in the directions hypothesized and were consistent with the findings from the comparisons between periods, providing further evidence that the period effects were due to changes in air quality, independent of season and meteorologic conditions or other potential confounders. Contrary to our hypothesis, however, we observed increases in platelet aggregation, red blood cells (RBCs) and white blood cells (WBCs) associated with the during-Olympics period, as well as significant negative associations of these biomarkers with pollutant concentrations. We did not observe significant changes in any of the HRV indices and DBP by period. However, we observed associations between a few HRV indices and pollutant concentrations. Changes in air pollution levels during the Beijing Olympics were associated with acute changes in biomarkers of pulmonary and systemic inflammation, oxidative stress, and hemostasis and in measures of cardiovascular physiology (HR and SBP) in healthy, young adults. These changes support the prominently hypothesized mechanistic pathways underlying the cardiorespiratory effects of air pollution.

Inflammatory and oxidative stress responses of healthy young adults to changes in air quality during the Beijing Olympics

RATIONALE

Unprecedented pollution control actions during the Beijing Olympics provided a quasi-experimental opportunity to examine biologic responses to drastic changes in air pollution levels.

OBJECTIVES

To determine whether changes in levels of biomarkers reflecting pulmonary inflammation and pulmonary and systemic oxidative stress were associated with changes in air pollution levels in healthy young adults.

METHODS

We measured fractional exhaled nitric oxide, a number of exhaled breath condensate markers (H(+), nitrite, nitrate, and 8-isoprostane), and urinary 8-hydroxy-2-deoxyguanosine in 125 participants twice in each of the pre- (high pollution), during- (low pollution), and post-Olympic (high pollution) periods. We measured concentrations of air pollutants near where the participants lived and worked. We used mixed-effects models to estimate changes in biomarker levels across the three periods and to examine whether changes in biomarker levels were associated with changes in pollutant concentrations, adjusting for meteorologic parameters.

MEASUREMENTS AND MAIN RESULTS

From the pre- to the during-Olympic period, we observed significant and often large decreases (ranging from -4.5% to -72.5%) in levels of all the biomarkers. From the during-Olympic to the post-Olympic period, we observed significant and larger increases (48-360%) in levels of these same biomarkers. Moreover, increased pollutant concentrations were consistently associated with statistically significant increases in biomarker levels.

CONCLUSIONS

These findings support the important role of oxidative stress and that of pulmonary inflammation in mediating air pollution health effects. The findings demonstrate the utility of novel and noninvasive biomarkers in the general population consisting largely of healthy individuals.

Halogenated flame retardants: do the fire safety benefits justify the risks?

Since the 1970s, an increasing number of regulations have expanded the use of brominated and chlorinated flame retardants. Many of these chemicals are now recognized as global contaminants and are associated with adverse health effects in animals and humans, including endocrine and thyroid disruption, immunotoxicity, reproductive toxicity, cancer, and adverse effects on fetal and child development and neurologic function. Some flame retardants such as polybrominated diphenyl ethers (PBDEs) have been banned or voluntarily phased out by manufacturers because of their environmental persistence and toxicity, only to be replaced by other organohalogens of unknown toxicity. Despite restrictions on further production in some countries, consumer products previously treated with banned retardants are still in use and continue to release toxic chemicals into the environment, and the worldwide use of organohalogen retardants continues to increase. This paper examines major uses and known toxic effects of commonly-used organohalogen flame retardants, replacements for those that have been phased out, their combustion by-products, and their effectiveness at reducing fire hazard. Policy and other solutions to maintain fire safety while reducing toxicity are suggested. The major conclusions are: (1) Flammability regulations can cause greater adverse environmental and health impacts than fire safety benefits. (2) The current options for end-of-life disposal of products treated with organohalogens retardants are problematic. (3) Life-cycle analyses evaluating benefits and risks should consider the health and environmental effects of the chemicals, as well as their fire safety impacts. (4) Most fire deaths and most fire injuries result from inhaling carbon monoxide, irritant gases, and soot. The incorporation of organohalogens can increase the yield of these toxic by-products during combustion. (5) Fire-safe cigarettes, fire-safe candles, child-resistant lighters, sprinklers, and smoke detectors can prevent fires without the potential adverse effects of flame retardant chemicals. (6) Alternatives to organohalogen flame retardant chemicals include using less flammable materials, design changes, and safer chemicals. To date, before evaluating their health and environmental impacts, many flame retardant chemicals have been produced and used, resulting in high levels of human exposure. As a growing literature continues to find adverse impacts from such chemicals, a more systematic approach to their regulation is needed. Before implementing new flammability standards, decision-makers should evaluate the potential fire safety benefit versus the health and environmental impacts of the chemicals, materials, or technologies likely to be used to meet the standard. Reducing the use of toxic or untested flame retardant chemicals in consumer products can protect human and animal health and the global environment without compromising fire safety.

Measurement of inflammation and oxidative stress following drastic changes in air pollution during the Beijing Olympics: a panel study approach

Ambient air pollution has been linked to cardiovascular and respiratory morbidity and mortality in epidemiology studies. Frequently, oxidative and nitrosative stress are hypothesized to mediate these pollution effects, however precise mechanisms remain unclear. This paper describes the methodology for a major panel study to examine air pollution effects on these and other mechanistic pathways. The study took place during the drastic air pollution changes accompanying the 2008 Olympics in Beijing, China. After a general description of air pollution health effects, we provide a discussion of panel studies and describe the unique features of this study that make it likely to provide compelling results. This study should lead to a clearer and more precise definition of the role of oxidative and nitrosative stress, as well as other mechanisms, in determining acute morbidity and mortality from air pollution exposure.

Superfluid-helium converter for accumulation and extraction of ultracold neutrons

We report the first successful extraction of accumulated ultracold neutrons (UCN) from a converter of superfluid helium, in which they were produced by downscattering neutrons of a cold beam from the Munich research reactor. Windowless UCN extraction is performed in vertical direction through a mechanical cold valve. This prototype of a versatile UCN source is comprised of a novel cryostat designed to keep the source portable and to allow for rapid cooldown. We measured time constants for UCN storage and extraction into a detector at room temperature, with the converter held at various temperatures between 0.7 and 1.3 K. The UCN production rate inferred from the count rate of extracted UCN is close to the theoretical expectation.

The in vitro activity of selected defensins against an isolate of Pseudomonas in the presence of human tears

BACKGROUND/AIMS

Pseudomonas aeruginosa is a major cause of severe bacterial keratitis and remains a difficult clinical entity to treat successfully with the current arsenal of antimicrobial agents. Defensins are small cationic peptides with broad in vitro antimicrobial activity and are potential ocular therapeutic agents. The authors characterised the in vitro activity of defensins NP-1 and NP-3a against P aeruginosa in the presence of human tears.

METHODS

A clinical Pseudomonas isolate was grown to mid-log phase, and 1 x 10(6 )colony forming units were exposed to the peptides (200 microg/ml) for up to 2 hours in the presence of varying concentrations (10-70%) of human tears.

RESULTS

For both peptides in the presence of 10% tears, >3 log units of killing was achieved within 30 minutes. In 70% tears, NP-1 produced >1 log unit of killing at 2 hours, indicating that, although reduced, its activity remained significant. In 20% tears, NP-3a demonstrated 2 log units of killing at 2 hours; however, the antimicrobial activity of this defensin was completely inhibited in the presence of 70% tears.

CONCLUSION

These in vitro data suggest that while the microbicidal activity of some defensins may be diminished at the ocular surface in vivo, significant activity is still possible with certain peptides.

Utilization of evidence-based computerized order sets in pediatrics

Little is known about utilization of different evidence-based order sets within computerized physician order entry (CPOE) systems. We designed a retrospective study of resident and attending physician order set utilization to evaluate the use of three evidence-based computerized order sets (asthma, post-appendectomy care, and community-acquired pneumonia (CAP)), and examine patient and admission characteristics associated with order set utilization in pediatrics. We studied all 529 asthma patients, 277 appendectomy patients, and 210 CAP patients admitted between 1 November 2001 and 30 November 2003 during implementation of standardized order sets at a large, independent, not-for-profit pediatric institution. We analyzed order set utilization for the three order sets and tested the relationship between order set use and potential factors associated with utilization. Order set utilization varied by condition (X(2)=339.2, p<0.001), with the asthma order set use rate highest (88.1%), followed by appendectomy order set utilization (79.4%), and substantially lower CAP order set use (21.1%). We found that trends in order set utilization also varied by condition. Only the asthma order set showed a trend of increasing use after implementation (z= -3.02, p=0.002). In addition, factors associated with order set utilization varied. Uses of the asthma and post-appendectomy order sets were associated with factors such as admission unit and case complexity. CAP order set utilization was associated with case complexity but not admission source. We conclude that health services organizations looking to implement computerized order sets to reduce unnecessary practice variation while promoting best practices must consider the different factors that may influence the use of each order set rather than relying on a one-size-fits-all implementation strategy. Further, issues such as the level of physician involvement in order set development and consensus around order set content may be particularly important factors influencing order set utilization.

Effect of a Follow-Up Professional Home Cleaning on Serial Dust and Blood Lead Levels of Urban Children

Children residing in Philadelphia, Pennsylvania, who were enrolled in a clinical trial of oral chelation therapy (n=73) were studied to determine the effects of a follow-up professional lead dust cleaning of their homes 18 mo after an initial cleaning and commencement of therapy. Home dust lead levels were determined from dust-wipe specimens collected from the kitchen and playroom floors, and from a playroom windowsill, prior to, immediately following, and 3 and 6 mo after the second cleaning. Children's blood lead levels were assessed at 3-mo intervals before and after the follow-up cleaning. Professional cleaning produced immediate decreases in dust lead levels; however, dust lead re-accumulated to precleaning levels within 3-6 mo. Frequent, repeated cleanings may be required if blood lead or dust lead levels are to be reduced and sustained at low levels in urban homes.

Dose range checking in a computer order entry system

We recently implemented a computer order entry (COE) system which uses decision support for dose range checking. In addition to providing decision support at the point of order entry via "alerts", the system tracks data regarding the occurrence of alerts related to dosing errors. We reviewed the dosing alerts for a "high risk" medications in a COE system. Telephone alerts were more likely to trigger alerts. There were more low dose than high dose alerts. Some alerts could be avoided by adjusting the threshold.

Acceptance of a medical first-responder role by fire fighters

STUDY OBJECTIVE

In July 1998, a pilot trial which used fire fighters as medical first-responders for the first time in Australia, was implemented in Melbourne. We aimed to assess the impact of the introduction of a medical first-responder role to the fire service, on the fire fighters both professionally and personally.

METHODS

Focus groups were conducted at the fire stations located in the study area. Data from the focus groups was collated and examined for themes. The issues identified as important through the focus groups were then incorporated into a questionnaire.

RESULTS

The fire fighters located at the pilot stations involved in the first-responder programme appear to view their new role as first-responders as a positive addition to their emergency profession. Some areas of the programme were identified by this study as in need of improvement. Some aspects of the communication strategies utilised by the Fire Brigade were highly criticised. Some aspects of the support system offered by the Fire Brigade also appear to be regarded as unfavourable.

CONCLUSION

Results from this study provide useful information on professional fire fighter first-responder programmes and their impact on participating personnel. These results can be used to improve training modules, communication strategies and support services.

Photodynamic therapy: the nurse's role

Patients with neovascular (wet) age-related macular degeneration, the leading cause of blindness in persons older than 50 years in developed countries, experience severe visual loss due to choroidal neovascularization, the growth of abnormal vessels under the retina. Photodynamic therapy is a new treatment modality that combines an intravenous injection of a photosensitizing drug, such as verteporfin, and nonthermal laser light application, which destroys choroidal neovascularization without damaging normal surrounding tissue. It has led to new challenges for nurses working in the ambulatory laser setting, including medication preparation, drug administration, and education regarding precautions and potential systemic side effects of photodynamic therapy.

Children with moderately elevated lead levels: is chelation with DMSA helpful?

This study evaluates the effectiveness (use under routine circumstances) of DMSA (2,3 dimercaptosuccinic acid) and environmental remediation as compared with placebo and environmental remediation on children with blood lead (BPb) levels of 30-45 micrograms/dL (1.45-2.17 mumol/L). The endpoints were BPb at 1 month and 6 months after study entry. This double-blind placebo-controlled trial involved 39 children aged 2-5 years, who were randomized to one course of DMSA or placebo. The mean BPb levels of the two groups at study entry were similar, placebo group 33.0 micrograms/dL (1.59 mumol/L) and the DMSA group 34.9 micrograms/dL (1.68 mumol/L). At 1 month (the end of treatment) the mean BPb levels of the two groups were: placebo group 33.2 micrograms/dL (1.60 mumol/L) and the DMSA group 27.4 micrograms/dL (1.32 mumol/L), p = 0.16. At 6 months, the mean BPb levels were 25.1 micrograms/dL (1.21 mumol/L) for the placebo group and 28.8 micrograms/dL (1.39 mumol/L) for the DMSA-treated group, p = 0.06. Neither of these differences is statistically significant. All children with BPb, in the range studied here, should receive environmental evaluation and remediation; DMSA does not improve long-term blood lead levels.

Role of cyclophilin A in the uptake of HIV-1 by macrophages and T lymphocytes

Cyclophilins are a family of proteins that bind cyclosporin A (CsA) and possess peptidyl-prolyl cis-trans isomerase activity. In addition, they are secreted by activated cells and act in a cytokine-like manner, presumably via signaling through a cell surface cyclophilin receptor. More recently, host-derived cyclophilin A (CyPA) has been shown to be incorporated into HIV-1 virions and its incorporation essential for viral infectivity. Here we present evidence supporting a role for viral-associated CyPA in the early events of HIV-1 infection. We report that HIV-1 infection of primary peripheral blood mononuclear cells can be inhibited by: (i) an excess of exogenously added CyPA; (ii) a CsA analogue unable to enter the cells; (iii) neutralizing antibodies to CyPA. Taken together with our observations that recombinant CyPA-induced mobilization of calcium in immortalized, as well as primary, CD4+ T lymphocytes, and that incubation of T cells with iodinated CyPA, followed by chemical cross-linking, resulted in the formation of a high molecular mass complex on the cell surface, these results suggest that HIV-1-associated CyPA mediates an early event in viral infection via interaction with a cellular receptor. This interaction may present a target for anti-HIV therapies and vaccines.

Positron emission tomography measurement of cerebral metabolic correlates of tryptophan depletion-induced depressive relapse

BACKGROUND

Short-term depletion of plasma tryptophan has been shown to result in depressive relapse in patients with remission of major depression. Positron emission tomography and single photon emission computed tomography studies implicated the dorsolateral prefrontal cortex, orbitofrontal cortex, thalamus, and caudate nucleus in the pathogenesis of depression. The purpose of this study was to measure cerebral metabolic correlates of tryptophan depletion-induced depressive relapse.

METHODS

Patients diagnosed as having major depression (N = 21) who clinically improved with serotonin reuptake inhibitors underwent 2 test days involving tryptophan depletion or placebo, followed 6 hours later by positron emission tomography scanning with fludeoxy-glucose F18. Brain metabolism was compared in patients with (n = 7) and without (n = 14) a tryptophan depletion-induced depressive relapse.

RESULTS

Tryptophan depletion resulted in a decrease in brain metabolism in the middle frontal gyrus (dorsolateral prefrontal cortex), thalamus, and orbitofrontal cortex in patients with a depletion-induced depressive relapse (but not in patients without depletion-induced relapse). Decreased brain metabolism in these regions correlated with increased depressive symptoms. Baseline metabolism was increased in prefrontal and limbic regions in relapse-prone patients.

CONCLUSION

Specific brain regions, including the middle frontal gyrus, thalamus, and orbitofrontal cortex, may mediate the symptoms of patients with major depression.

Positron emission tomography measurement of cerebral metabolic correlates of yohimbine administration in combat-related posttraumatic stress disorder

BACKGROUND

We have previously reported an increase in symptoms of anxiety in patients with posttraumatic stress disorder (PTSD) following administration of the beta 2-antagonist yohimbine, which stimulates brain norepinephrine release. Preclinical studies show decreased metabolism in the neocortex and the caudate nucleus with high-dose yohimbine-induced norepinephrine release, but low levels of norepinephrine release result in an increase in metabolism in these areas.

METHODS

We used positron emission tomography and fludeoxyglucose F 18 to measure brain metabolism in Vietnam combat veterans with PTSD (n = 10) and healthy age-matched control subjects (n = 10), following administration of yohimbine (0.4 mg/kg) or placebo in a randomized, double-blind fashion.

RESULTS

Yohimbine resulted in a significant increase in anxiety in the patients with PTSD, but not in healthy subjects. There was a significant difference in brain metabolic response to yohimbine in patients with PTSD compared with healthy subjects in prefrontal, temporal, parietal, and orbitofrontal cortexes. Metabolism tended to decrease in patients with PTSD and increase in healthy subjects following administration of yohimbine.

CONCLUSION

These findings are consistent with our previous hypothesis of enhanced norepinephrine release in the brain with yohimbine in patients with PTSD.

Finding the right chemistry

For most hospital executives, learning that a physician group on their staff plans to affiliate with a practice management company causes significant concern. Unsettling images of a widening gulf between physicians and the hospital, accompanied by struggles over ancillary services, come to mind.

A pharmacologic continuum in the treatment of rhinorrhea: the clinician as economist

The economics of medications are now of great concern to health-care providers. Pharmacoeconomic issues are by no means simple, and yet, ironically, they assume greater importance in prescribing for modest disorders like rhinorrhea than for life-threatening conditions. The therapeutic continuum of quality and cost becomes foreshortened, and safety is an additional concern. Choosing the appropriate medication for rhinorrhea, then, can pose a challenge to the clinician, just as choosing a vital medication. This paper reviews the usage, quality, and cost of major therapies for the rhinorrhea that occurs secondary to various conditions, including nasal steroids, antihistamines and anticholinergics, and discusses the role of the clinician in factoring costs into therapy.

Physicians, pharmacists, and home infusion antibiotic therapy

Home infusion antibiotic therapy has been proven effective, safe, and economical for a variety of infectious diseases. Programs for home infusion have been established in hospitals, home care companies, and physician offices. These programs utilize the combined efforts of physicians, pharmacists, and nurses and rely heavily on the active participation of the patient to provide quality care for a fraction of the cost of hospital-based infusion. Additionally, given a choice, patients prefer to receive intravenous antibiotic therapy at home. Current reimbursement policies, however, acknowledge neither the economic benefit to be derived from home therapy nor patient preference for this mode of intravenous antibiotic therapy.

Rapid contrast sensitivity assessment in keratoconus

Contrast sensitivity derangement may accompany keratoconus even in the presence of normal or near normal Snellen visual acuity. This has been demonstrated with computer-driven contrast sensitivity test devices. The purpose of this study was to evaluate the utility and efficacy of rapid screening devices for contrast sensitivity testing. However, such devices are often cumbersome and difficult to use clinically. We tested 12 patients with keratoconus on 2 simple chart systems designed to test contrast sensitivity in a rapid and clinically useful manner: the Vistech chart and the Regan multi-contrast visual acuity charts. Both devices detected the contrast sensitivity abnormalities present in early keratoconus, but some patients [with greater than or equal to 6/12 (20/40) visual acuity] were unable to respond to areas of the charts corresponding to high spatial frequency and/or low contrast tasks. Such simple wall charts may be useful in measuring the visual abnormalities in early keratoconus, in monitoring the progression of the disease, and in evaluating various treatment options.