Building a qualitative systems map: applying systems thinking to the commercial determinants of health and industry influence on health policy

Background

Unhealthy commodities are major drivers of the global burden of noncommunicable diseases. Commercial actors attempt to influence policy to undermine regulation and existing literature draws attention to the underlying macro-level factors that enable this influence. Public health literature also suggests that industry adapts to regulation and such influence may thus be considered a complex adaptive system. Therefore, this study aimed to build a qualitative systems map to help communicate the complexity of industry influence and develop a tool to facilitate the identification of interventions in follow up research.

Methods

In-person group model grouping workshops were adapted for the online environment. A preliminary qualitative systems map was developed by synthesising two recent studies to facilitate workshop discussions and expedite the mapping process. Twenty-three small group system mapping workshops were conducted with a total of 52 stakeholders, representing researchers, civil society, and public officials from various geographical regions.

Results

The qualitative systems map identifies five pathways through which industry influences policy: a) direct access to public sector decisionmakers; b) creation of confusion and doubt about policy decisions; c) prioritisation of commercial growth; d) industry leveraging the legal and dispute settlement processes; and e) industry leveraging policymaking rules and processes. The pathways contribute to perpetuating macro-level factors that enable industry to deploy practices to influence policy.

Conclusions

A system thinking approach can be applied to industry influence on health policy to depict a complex adaptive system. Interventions need to take into consideration the system's complexity and adaptivity. Further research is needed to test, and improve the systems map and identify interventions to achieve systems change.

A patient-designed tissue-engineered model of the infiltrative glioblastoma microenvironment

Glioblastoma is an aggressive brain cancer characterized by diffuse infiltration. Infiltrated glioma cells persist in the brain post-resection where they interact with glial cells and experience interstitial fluid flow. We use patient-derived glioma stem cells and human glial cells (i.e., astrocytes and microglia) to create a four-component 3D model of this environment informed by resected patient tumors. We examine metrics for invasion, proliferation, and putative stemness in the context of glial cells, fluid forces, and chemotherapies. While the responses are heterogeneous across seven patient-derived lines, interstitial flow significantly increases glioma cell proliferation and stemness while glial cells affect invasion and stemness, potentially related to CCL2 expression and differential activation. In a screen of six drugs, we find in vitro expression of putative stemness marker CD71, but not viability at drug IC50, to predict murine xenograft survival. We posit this patient-informed, infiltrative tumor model as a novel advance toward precision medicine in glioblastoma treatment.

Psilocybin with psychological support for treatment-resistant depression: six-month follow-up

RATIONALE

Recent clinical trials are reporting marked improvements in mental health outcomes with psychedelic drug-assisted psychotherapy.

OBJECTIVES

Here, we report on safety and efficacy outcomes for up to 6 months in an open-label trial of psilocybin for treatment-resistant depression.

METHODS

Twenty patients (six females) with (mostly) severe, unipolar, treatment-resistant major depression received two oral doses of psilocybin (10 and 25 mg, 7 days apart) in a supportive setting. Depressive symptoms were assessed from 1 week to 6 months post-treatment, with the self-rated QIDS-SR16 as the primary outcome measure.

RESULTS

Treatment was generally well tolerated. Relative to baseline, marked reductions in depressive symptoms were observed for the first 5 weeks post-treatment (Cohen's d = 2.2 at week 1 and 2.3 at week 5, both p < 0.001); nine and four patients met the criteria for response and remission at week 5. Results remained positive at 3 and 6 months (Cohen's d = 1.5 and 1.4, respectively, both p < 0.001). No patients sought conventional antidepressant treatment within 5 weeks of psilocybin. Reductions in depressive symptoms at 5 weeks were predicted by the quality of the acute psychedelic experience.

CONCLUSIONS

Although limited conclusions can be drawn about treatment efficacy from open-label trials, tolerability was good, effect sizes large and symptom improvements appeared rapidly after just two psilocybin treatment sessions and remained significant 6 months post-treatment in a treatment-resistant cohort. Psilocybin represents a promising paradigm for unresponsive depression that warrants further research in double-blind randomised control trials.

Regulation of dopaminergic function: an [18F]-DOPA PET apomorphine challenge study in humans

Dopaminergic function has a key role in normal brain function, dopaminergic dysfunction being implicated in numerous neuropsychiatric disorders. Animal studies show that dopaminergic stimulation regulates dopaminergic function, but it is not known whether this exists in humans. In the first study (study 1), we measured dopamine synthesis capacity (indexed as K_i^cer) to identify the relationship between baseline and change in K_i^cer under resting conditions for comparison with effects of dopaminergic stimulation. In the second study (study 2), we used a within-subjects design to test effects of dopaminergic stimulation on dopamine synthesis capacity. In study 1, eight volunteers received two ¹⁸F-DOPA scans on separate days, both at rest. In study 2, 12 healthy male volunteers received two ¹⁸F-DOPA positron emission tomographic (PET) scans after treatment with either the dopamine partial agonist apomorphine (0.03 or 0.005 mg kg^-1) or placebo. In study 1, no significant correlation was found between baseline and change in dopamine synthesis capacity between scans (r=-0.57, n=8, P=0.17, two-tailed). In study 2, a significant negative correlation was found between baseline dopamine synthesis capacity and percentage change in dopamine synthesis capacity after apomorphine challenge (r=-0.71, n=12, P=0.01, two-tailed). This correlation was significantly different (P<0.01) from the correlation between baseline and change in dopamine synthesis capacity under unstimulated conditions. One-way repeated-measures analysis of variance showed a significant group (study 1/study 2) × time interaction (F(1,18)=11.5, P=0.003). Our findings suggest that regulation of dopamine synthesis capacity by apomorphine depends on baseline dopamine function, consistent with dopamine stimulation stabilizing dopaminergic function. Loss of this autoregulation may contribute to dopaminergic dysfunction in brain disorders such as schizophrenia, substance dependence, and Parkinson's disease.

From the prodrome to chronic schizophrenia: the neurobiology underlying psychotic symptoms and cognitive impairments

Schizophrenia is a chronic psychotic disorder that remains a considerable cause of global disease burden. Cognitive impairments are common and contribute significantly to the morbidity of the disorder. Over the last two decades or so molecular imaging studies have refined understanding of the pathophysiology underlying the development of psychosis and cognitive impairments. Firstly they have consistently implicated presynaptic dopaminergic dysfunction in the disorder, finding that dopamine synthesis capacity, dopamine release and baseline dopamine levels are increased in the illness. Secondly recent findings show that dopamine synthesis capacity is elevated in those that go on to develop psychosis in the following year, but not in those that do not, and appears to increase further with the development of psychosis. Thirdly evidence links greater dopamine synthesis capacity to poorer cognitive performance and altered frontal cortical function measured using functional imaging during cognitive tasks. Finally they have provided data on the nature of other neurofunctional alterations in the disorder, in particular in the serotonergic system and neuroinflammation. We review these findings and discuss their implications for understanding the neurobiology of psychosis and cognitive impairments in schizophrenia.

Use of a transdermal matrix patch of buprenorphine in cats: preliminary pharmacokinetic and pharmacodynamic data

Six domestic shorthair cats, aged three to four years and weighing 5.1 to 7.4 kg, were used to assess the thermal antinociceptive effect of a transdermal buprenorphine patch, designed to supply 35 mug buprenorphine/hour, which was applied to the shaved thorax. The cats' thermal thresholds were tested before the patch was applied and two, four, six, eight, 10, 12, 14 and 16 hours after it had been applied, and then every six hours until it was removed after 72 hours, and for a further 24 hours afterwards. Blood was collected at each time to measure the plasma concentration of buprenorphine. The patches did not produce a significant change in the thermal thresholds of the cats throughout the testing period. The mean (sd) peak plasma buprenorphine concentration was 10 (0.81) ng/ml.

Effects of midazolam and sarmazenil on the equine electroencephalogram during anaesthesia with halothane in oxygen

The electroencephalographic (EEG) effects of a rapid infusion of midazolam and sarmazenil following a bolus of midazolam were investigated in eight Welsh mountain ponies anaesthetized with 0.8% halothane in oxygen. The peak plasma concentration of midazolam was 2.13 +/- 0.34 ng/mL (mean +/- SD) occurring 5 min after the start of the infusion. Sarmazenil concentrations were not measured. The 95% spectral edge frequency of the EEG decreased by a maximum of 39.8 +/- 15.8%, 10 min after the start of the midazolam infusion. No changes were seen in median frequency of the EEG or the second differential of the middle latency auditory evoked response. The variability of median frequency (F50) and spectral edge frequency (F95) were reduced by a maximum of 80 +/- 7 and 84 +/- 7%, respectively. The sarmazenil infusion reversed the effects of a bolus of midazolam on the variability of F50 and the magnitude and variability of F95. The second differential of the middle latency auditory evoked potential (DD) was increased by 56.4 +/- 69.3%, 10 min after the start of the sarmazenil infusion. There were no statistically significant differences in EEG variables between the baseline of the midazolam infusion and 10 min after the start of the sarmazenil infusion. Midazolam infusion resulted in specific and unusual changes in the EEG of anaesthetized ponies. These changes were completely reversed by sarmazenil infusion. The data presented suggest that sarmazenil has no intrinsic effect upon the EEG.

Morphine, pethidine and buprenorphine disposition in the cat

Pharmacokinetics of morphine, buprenorphine and pethidine were determined in 10 cats. Six cats received morphine (0.2 mg/kg) intravenously and four intramuscularly. Five received buprenorphine (0.01 mg/kg) intravenously and six intramuscularly. Six received pethidine (5 mg/kg) intramuscularly. Jugular venous blood samples were collected at time points to 24 h, and plasma morphine concentrations were measured by high performance liquid chromatograpy (HPLC), buprenorphine by radioimmunoassay (RIA) and pethidine by gas chromatography. Our data for morphine show elimination half-life (t1/2el) 76.3 min intravenous (i.v.) and 93.6 min intramuscular (i.m.); mean residence time (MRT) 105.0 and 120.5 min; clearance (Clp) 24.1 and 13.9 mL/kg/min; and volume of distribution (V(dss)) 2.6 and 1.7 L/kg, respectively. Comparable data for buprenorphine are t1/2el 416.8 and 380.2 min; MRT 417.6 and 409.8 min; Clp 16.7 and 23.7 mL/kg/min; and V(dss) 7.1 and 8.9 L/kg. For i.m. pethidine, t1/2el 216.4 min; MRT 307.5 min; Clp 20.8 mL/kg/min and V(dss) 5.2 L/kg. For i.m. dosing, the tmax for morphine, buprenorphine and pethidine were 15, 3 and 10 min, respectively. The pharmacokinetics of the three opioids in cats are broadly comparable with those of the dog, although there is a suggestion that the cat may clear morphine more slowly.

Sociology of an interstellar vehicle

The successful functioning of an interstellar flight is dependent on the sociology of the crew. The crew needs to be homogeneous culturally to minimise conflict. A genetically similar crew is suggested as well, in order to provide an initial gene pool for a species differentiation after the establishment of a colony around another star. The goal of interstellar flight should be to extend man or his related descendants throughout the Galaxy and eventually the Universe.

Effects of ketamine on the equine electroencephalogram during anesthesia with halothane in oxygen

OBJECTIVE

To investigate the effects of ketamine on the electroencephalogram (EEG) of the horse.

STUDY DESIGN

Prospective experimental study.

ANIMALS

Eight Welsh mountain pony geldings weighing between 280 and 330 kg, 5 to 9 years old.

METHODS

During halothane anesthesia at an end-tidal halothane concentration between 0.75 and 0.85%, the EEG frequency power spectrum and the auditory evoked potential were recorded while an infusion of ketamine was given. Ketamine 200 mg was infused over 5 minutes in 8 ponies. The effects of ketamine on the EEG were recorded continuously during the infusion and for a further 55 minutes.

RESULTS

The ketamine infusion produced a plasma ketamine concentration that was significantly greater than the baseline until 7 minutes after the start of the infusion. The highest recorded ketamine concentration was 4.2+/-1.1 microg/ml recorded at 5 minutes after the start of the infusion. The spectral edge and median frequency of the EEG and the midlatency of the auditory evoked potential were compared with those recorded before the start of the infusion. The spectral edge, median frequencies and mid-latency of the auditory evoked potential were reduced by 21+/-13%, 31+/-20% and 19+/-36% respectively (mean +/- SD). Only the reduction in spectral edge frequency reached statistical significance.

CONCLUSIONS

These results compared with those from other anesthetic and sedative agents suggest that the spectral edge frequency is an indicator of general central nervous system depression whereas the median frequency may be an indicator of antinociception.

Pancreatic alpha cell function in the fetal foal during late gestation

Plasma glucagon concentrations were measured in chronically catheterized fetal ponies and their mothers between 260 days of gestation and term (approximately 335 days). Fetal alpha cell responses to arginine and variations in fetal glycaemia were also examined during late gestation. Immunoreactive glucagon was present in fetal plasma at 260 days of gestation and its concentration in utero increased after 320 days and then again at birth. Maternal plasma glucagon concentrations were higher after 300 days than earlier in gestation but were lower than the corresponding fetal value throughout the period of gestation studied. Fetal alpha cells responded rapidly to intravenous arginine infusion but not to changes in the fetal glucose level induced by maternal fasting for 36 h or by intrafetal infusion of glucose. The maximal increment in fetal plasma glucagon in response to arginine occurred at the end of the 5 min infusion and was positively correlated to the basal pre-infusion plasma glucagon concentrations. Fetal plasma glucagon concentrations were unaffected by either hyper- or hypoglycaemia. In contrast, maternal plasma glucagon levels were significantly increased by fasting. These observations indicate that equine pancreatic alpha cells are functional in utero but that they are unresponsive to variations in glycaemia until after birth.

An experimental design approach to the optimisation of a flow injection analysis method for glycine

A flow injection analysis method for the determination of glycine, based on the reaction with ortho-phtalaldehyde and N-acetylcysteine in a basic buffer, was optimised. In the first step screening of the variables, to select the most important ones, was performed using: (i) a half-fraction factorial design and (ii) a quarter-fraction factorial design, for five factors at two levels. The effects of the factors on the peak height were calculated from both screening designs and compared. For the half-fraction factorial design (resolution IV), the significance of the factor effects on the peak height was checked by: (i) comparing them with a critical effect, calculated from two-factor interactions and based on a t-test, (ii) using a non parametric approach and (iii) drawing a normal probability plot. For the quarter-fraction factorial design (resolution III) the significance of the effects of the factors on the peak height was checked using: (i) a randomization test method, (ii) the non parametric method and (iii) a normal probability plot. In the second step, the factor found to be of importance was optimised using the uniplex method.

Endocrine changes in cerebrospinal fluid, pituitary effluent, and peripheral plasma of anesthetized ponies

OBJECTIVE

To investigate the effects of inhalation and total IV anesthesia on pituitary-adrenal activity in ponies.

ANIMALS

9 healthy ponies: 5 geldings and 4 mares.

PROCEDURE

Catheters were placed in the cavernous sinus below the pituitary gland and in the subarachnoid space via the lumbosacral space. After 72 hours, administration of acepromazine was followed by induction of anesthesia with thiopentone and maintenance with halothane (halothane protocol), or for the IV protocol, anesthesia induction with detomidine and ketamine was followed by maintenance with IV infusion of a detomidine-ketamine-guaifenesin combination. Arterial blood pressure and gas tensions were measured throughout anesthesia. Peptide and catecholamine concentrations were measured in pituitary effluent, peripheral plasma, and CSF. Peripheral plasma cortisol, glucose, and lactate concentrations also were measured.

RESULTS

Intravenous anesthesia caused less cardiorespiratory depression than did halothane. ACTH, metenkephalin, arginine vasopressin, and norepinephrine pituitary effluent and peripheral plasma concentrations were higher during halothane anesthesia, with little change during intravenous anesthesia. Pituitary effluent plasma beta-endorphin and peripheral plasma cortisol concentrations increased during halothane anesthesia only. Dynorphin concentrations did not change in either group. Hyperglycemia developed during intravenous anesthesia only. Minimal changes occurred in CSF hormonal concentrations during anesthesia.

CONCLUSION

The pituitary gland has a major role in maintaining circulating peptides during anesthesia. Compared with halothane, IV anesthesia appeared to suppress pituitary secretion.

Intrapleural bupivacaine analgesia in chest trauma: a randomized double-blind controlled trial

A randomized double-blind study was undertaken to investigate whether 0.25 per cent bupivacaine administered intrapleurally is an effective and reasonably safe method of obtaining analgesia in patients with thoracic injuries. A total of 120 patients complaining of pain after chest injury were entered into the trial. All had thoracostomy tubes already in situ. Of 60 patients who were given the test dose of bupivacaine intrapleurally, 37 obtained satisfactory pain relief for 2 or more hours compared with only 9 of 60 patients who received saline P less than 0.000001). Duration of analgesia in the test group (mean 3.9 h) was significantly longer than that in the control group (mean 0.9 h) P less than 0.005). There were no important side-effects attributable to the bupivacaine administered. We conclude that intrapleural bupivacaine is an effective and reasonably safe method for obtaining analgesia in patients who have chest drain tubes inserted.

Aneuploidy in Drosophila, IV. Inhalation studies on the induction of aneuploidy by nitriles

The Drosophila ZESTE system was used to monitor the induction of sex chromosome aneuploidy following inhalation exposure of adult females to four nitriles: acetonitrile, propionitrile, acrylonitrile and fumaronitrile. Acetonitrile and propionitrile were highly effective aneuploidogens, inducing both chromosome loss and chromosome gain following brief exposures to low concentrations of these chemicals, and these nitriles also induced rapid paralysis. Acrylonitrile-induced chromosome loss only but did not induce paralysis. Fumaronitrile, in contrast with the results reported in yeast, was ineffective in inducing chromosome loss or gain. Virtually all exceptional offspring induced by acetonitrile and propionitrile were recovered in the first sampled eggs, corresponding to treated mature oocytes. Additionally, the time interval between treatment and sampling was shown to be important, suggesting rapid loss or detoxification of the nitriles. Genetic analysis demonstrated that most aneuploids resulted from induced segregation errors during the first division of meiosis. Cold treatments were found to be ineffective in enhancing the effects of acetonitrile, suggesting important differences between the Drosophila and yeast aneuploidy detection systems. Possible mechanisms by which nitriles may disrupt chromosome segregation in Drosophila oocytes are considered.