Beyond the label: current evidence and future directions for the interrelationship between electronic cigarettes and mental health

Electronic cigarette use has dramatically increased over the last decade. With this recent technological development and wide range of constituents in various products, putative adverse effects on the brain and body have been largely unexplored. Here, we review current evidence linking electronic nicotine cigarette use with potential health consequences and provide evidence supporting an association between drug use and depression in humans. We also examine the biological effects of individual constituents in electronic cigarette aerosols, which include labeled ingredients, such as propylene glycol, vegetable glycerin, nicotine, and flavorants, as well as unlabeled ingredients found in the aerosols, such as carbonyls and heavy metals. Lastly, we examine the effects of electronic cigarette use on endogenous metabolism via changes in cytochrome P450 enzymes, which can thereby impact therapeutic outcomes. While the current evidence offers insight into the potential effects of electronic cigarette use on biological processes, further studies are necessary to determine the long-term clinical relevance of aerosol inhalation.

Exomap1 mouse: a transgenic model for in vivo studies of exosome biology

Exosomes are small extracellular vesicles (sEVs) of ~30-150 nm in diameter that have the same topology as the cell, are enriched in selected exosome cargo proteins, and play important roles in health and disease. To address large unanswered questions regarding exosome biology in vivo, we created the exomap1 transgenic mouse model. In response to Cre recombinase, exomap1 mice express HsCD81mNG, a fusion protein between human CD81, the most highly enriched exosome protein yet described, and the bright green fluorescent protein mNeonGreen. As expected, cell type-specific expression of Cre induced the cell type-specific expression of HsCD81mNG in diverse cell types, correctly localized HsCD81mNG to the plasma membrane, and selectively loaded HsCD81mNG into secreted vesicles that have the size (~80 nm), topology (outside out), and content (presence of mouse exosome markers) of exosomes. Furthermore, mouse cells expressing HsCD81mNG released HsCD81mNG-marked exosomes into blood and other biofluids. Using high-resolution, single-exosome analysis by quantitative single molecule localization microscopy, we show here that that hepatocytes contribute ~15% of the blood exosome population whereas neurons contribute <1% of blood exosomes. These estimates of cell type-specific contributions to blood EV population are consistent with the porosity of liver sinusoidal endothelial cells to particles of ~50-300 nm in diameter, as well as with the impermeability of blood-brain and blood-neuron barriers to particles >5 nm in size. Taken together, these results establish the exomap1 mouse as a useful tool for in vivo studies of exosome biology, and for mapping cell type-specific contributions to biofluid exosome populations. In addition, our data confirm that CD81 is a highly-specific marker for exosomes and is not enriched in the larger microvesicle class of EVs.

Nasal accumulation and metabolism of Δ9-tetrahydrocannabinol following aerosol ('vaping') administration in an adolescent rat model

Passive aerosol exposure to Δ9-tetrahydrocannabinol (THC) in laboratory animals results in faster onset of action and less extensive liver metabolism compared to most other administration routes and might thus provide an ecologically relevant model of human cannabis inhalation. Previous studies have, however, overlooked the possibility that rodents, as obligate nose breathers, may accumulate aerosolized THC in the nasal cavity, from where the drug might directly diffuse to the brain. To test this, we administered THC (ten 5-s puffs of 100 mg/mL of THC) to adolescent (31-day-old) Sprague-Dawley rats of both sexes. We used liquid chromatography/tandem mass spectrometry to quantify the drug and its first-pass metabolites - 11-hydroxy-Δ9-THC (11-OH-THC) and 11-nor-9-carboxy-Δ9-THC (11-COOH-THC) - in nasal mucosa, lungs, plasma, and brain (olfactory bulb and cerebellum) at various time points after exposure. Apparent maximal THC concentration and area under the curve were ∼5 times higher in nasal mucosa than in lungs and 50-80 times higher than in plasma. Concentrations of 11-OH-THC were also greater in nasal mucosa and lungs than other tissues, whereas 11-COOH-THC was consistently undetectable. Experiments with microsomal preparations confirmed local metabolism of THC into 11-OH-THC (not 11-COOH-THC) in nasal mucosa and lungs. Finally, whole-body exposure to THC deposited substantial amounts of THC (∼150 mg/g) on fur but suppressed post-exposure grooming in rats of both sexes. The results indicate that THC absorption and metabolism in nasal mucosa and lungs, but probably not gastrointestinal tract, contribute to the pharmacological effects of aerosolized THC in male and female rats.

Pneumorrhachis following cervical spine surgery

A 66-year-old man experienced symptomatic pneumorrhachis (air within the spinal canal) following a cervical laminoplasty for the excision of meningioma. Following an uneventful intraoperative course, he suffered a fluctuating hemiparesis of varying severity. Urgent imaging demonstrated extradural and intradural air in the spinal canal. Treatment with supplemental oxygen and dexamethasone was commenced, and the patient's symptoms improved over a period of three days with full resolution at six weeks. Pneumorrhachis can be avoided by allowing air to escape from the spinal canal through positioning, and displacement with irrigation fluid at the time of wound closure. However, if pneumorrhachis does occur, oxygen therapy, positioning of the patient to mitigate the gravitational effect of the air bubbles and supportive treatment are the central elements of management. Other possible causes of neurological deficit should be ruled out. This is particularly important as treatment options for some differential diagnoses can potentially cause harm if started based on clinical impression alone, for example, re-exploration for suspected haematoma. Only a small number of previous reports have described symptomatic pneumorrhachis as a complication of spinal surgery. This patient was successfully managed with conservative measures following the exclusion of other spinal cord pathologies.

Differential Expression Patterns of Lynx Proteins and Involvement of Lynx1 in Prepulse Inhibition

Negative allosteric modulators, such as lynx1 and lynx2, directly interact with nicotinic acetylcholine receptors (nAChRs). The nAChRs are integral to cholinergic signaling in the brain and have been shown to mediate different aspects of cognitive function. Given the interaction between lynx proteins and these receptors, we examined whether these endogenous negative allosteric modulators are involved in cognitive behaviors associated with cholinergic function. We found both cell-specific and overlapping expression patterns of lynx1 and lynx2 mRNA in brain regions associated with cognition, learning, memory, and sensorimotor processing, including the prefrontal cortex (PFC), cingulate cortex, septum, hippocampus, amygdala, striatum, and pontine nuclei. Since lynx proteins are thought to play a role in conditioned associations and given the expression patterns across brain regions, we first assessed whether lynx knockout mice would differ in a cognitive flexibility task. We found no deficits in reversal learning in either the lynx1^–/– or lynx2^–/– knockout mice. Thereafter, sensorimotor gating was examined with the prepulse inhibition (PPI) assessment. Interestingly, we found that both male and female lynx1^–/– mice exhibited a deficit in the PPI behavioral response. Given the comparable expression of lynx2 in regions involved in sensorimotor gating, we then examined whether removal of the lynx2 protein would lead to similar behavioral effects. Unexpectedly, we found that while male lynx2^–/– mice exhibited a decrease in the baseline startle response, no differences were found in sensorimotor gating for either male or female lynx2^–/– mice. Taken together, these studies provide insight into the expression patterns of lynx1 and lynx2 across multiple brain regions and illustrate the modulatory effects of the lynx1 protein in sensorimotor gating.

Multidimensional Intersection of Nicotine, Gene Expression, and Behavior

The cholinergic system plays a crucial role in nervous system function with important effects on developmental processes, cognition, attention, motivation, reward, learning, and memory. Nicotine, the reinforcing component of tobacco and e-cigarettes, directly acts on the cholinergic system by targeting nicotinic acetylcholine receptors (nAChRs) in the brain. Activation of nAChRs leads to a multitude of immediate and long-lasting effects in specific cellular populations, thereby affecting the addictive properties of the drug. In addition to the direct actions of nicotine in binding to and opening nAChRs, the subsequent activation of circuits and downstream signaling cascades leads to a wide range of changes in gene expression, which can subsequently alter further behavioral expression. In this review, we provide an overview of the actions of nicotine that lead to changes in gene expression and further highlight evidence supporting how these changes can often be bidirectional, thereby inducing subsequent changes in behaviors associated with further drug intake.

FRI0419 LOW DOSE OF GLUCOCORTICOIDS FOR PAIN CONTROL IN THE ESTROGEN-DEPENDENT PRIMARY POLYARTICULAR OSTEOARTHRITIS

Background:

Low doses of glucocorticoids (GCs) can be useful in the management of osteoarthritis when it is related to hypoestrogenic states (estrogen-dependent primary polyarticular osteoarthritis [EDPOA]), that usually can appear after the menopause. Deflazacort is a GC that has similar anti-inflammatory effects than other steroids, but with fewer side effects.

Objectives:

To describe the average dose of GCs that best controlled articular pain, based on tender joint count in patients with EDPOA.

Methods:

The diagnosis of EDPOA was made in postmenopausal patients with polyarticular compromised (six or more joints affected), morning stiffness less than 30 minutes, erythrocyte sedimentation rate less than 45mm/hour and imaging studies with changes related to osteoarthritis (radiography, magnetic resonance imaging or bone scintigraphy). Patients with autoimmune diseases such as rheumatoid arthritis, lupus or Sjögren syndrome were excluded.

The clinical records of patients diagnosed with EDPOA and treated between January 2015 and June 2019 at the Valle del Lili foundation Hospital were reviewed. The patients treated with deflazacort GC were included. Pain was assessed by the treating rheumatologist using the visual analog scale (VAS, possible score 0-10). Tender joints were those with VAS> 5. The count of compromised joints was compared with inflammatory findings on bone scintigraphy (Figure 1).

Figure 1.

Comparison between number of joints with inflammatory findings on bone scintigraphy and number of swollen joints in physical evaluation

The number of tender joints was recorded at the start of treatment, which was a dose of 6 mg/day of deflazacort for two months. Subsequently, the dose was reduced depending on the improvement of pain (items: intensity of pain and number of tender joints) until achieving a stabilization along the time with an improvement of 75% of the items evaluated. The number of painful joints was recorded again two months after the stabilization on pain control was achieved.

Quantitative variables were described with medians and interquartile ranges because the absence of normal distribution of the sample size. To assess the presence of a significant decrease on the number of tender joints the Wilcoxon range test was used, a value of p<0.001 was considered statistically significant. The data were analyzed with Stata v.15.

Results:

Twenty-eight patients with EDPOA were included, with a median of age of 50 years (IQR 44-51), 56 years (IQR 52-66) and 61 years (IQR 54-69) at the time of menopause, onset of symptoms and the diagnosis of EDPOA respectively. A median of 18 tender joints (IQR 10-27) was obtained from the physical examination of the records reviewed. The dose of deflazacort that achieved stabilization on the improvement of the pain along the time was 21mg/week (IQR 12-21); after 8 weeks of treatment the number of tender joints was 2 (IQR 1-4), which implies a reduction of 14 (IQR 8-20; p<0.0001) on the tender joint count (Figure 2).

Figure 2.

Number of tender joints before and after eight weeks of treatment achieving with a stable pain control in patients with EDPOA treated with deflazacort with a media dose of 3mgr/day.

Conclusion:

In this case series a media dose of deflazacort of 21mg per week (3mg/day) was useful to significantly reduce the number of tender joints in patients with EDPOA.

References:

[1]Roman-Blas JA, Castañeda S, Largo R,et al. Osteoarthritis associated with estrogen deficiency. Arthritis Research & Therapy 2009;11:241.

[2]Cvoro A, Yuan C, Paruthiyil S,et al. Crosstalk between glucocorticoid and estrogen receptors occurs at a subset of proinflammatory genes. The Journal of Immunology 2011;186:4354-4360.

[3]Féline K, Marion K, Annelies B,et al. Results of a 6-week treatment with 10 mg prednisolone in patients with hand osteoarthritis (HOPE): a double-blind, randomised, placebo-controlled trial. Lancet 2019;394:1993-2001.

Disclosure of Interests:

None declared

MAPSSIC, a communicating MAPS-based intracerebral positrons probe for deep brain imaging in awake and freely-moving rats

Radioisotope imaging is a powerful tool to understand the biological mechanisms in-vivo, especially in the brain of small animals, providing a significant model to study the human brain.

In this context, we have developed and built a pixelated intracerebral positron probe to be embedded on awake and freely moving small animals, typically rats. This pixelated probe will represent a key instrument for neuroscientists to study neural mechanisms and correlate them to behavioral experiments.

We describe in this paper the simulations carried out to design the intracerebral sensor, its architecture, and the detection of positrons in a volume with a couple of sensors assembled back-to-back. We also depict the architecture of the wireless acquisition system. Finally, we present the first measurements performed in real-time by this miniaturized probe with sealed radioactive sources and a 18F solution.

[How to select a prosthesis for a primary hip replacement? Minimum acceptable survival: results of a consensus of experts]

BACKGROUND

One of the most critical points in the planning of hip replacement surgeries is the selection of the implant, since its survival significantly impacts the patients health. However, the ideal survival time that an implant must prove to be selected has not been defined. The objective of this consensus is to define minimum performance standards for the selection of conventional primary hip replacement prosthesis.

MATERIAL AND METHODS

The consensus was carried out using the methodology of nominal group. This included: 1. A review of the available evidence and the issues to be evaluated, 2. Meeting for the vote and discussion, 3. Quantitative statistical analysis with median (M) and interquartile range (IQR) and qualitative one with proportions of the results to generate recommendations.

RESULTS

The primary source of information for prosthesis selection (M: 8; IQR: 7-9), choice in the event of conflicting evidence (M: 8; IQR: 7-9), or limited evidence in the literature (M: 7; IQR: 4.75-825) should be national registries. The minimum acceptable follow-up is 10 years (M: 9; IQR: 8-9) and the minimum acceptable survival is 90% at 10 years (M: 8; IQR: 5-8.5).

DISCUSSION

According to these results, the consensus of experts proposed that the selection of the implant for conventional primary hip replacement must be based on the information published in the national registries and that the prosthesis must have a minimum follow-up of 10 years and show a minimum survival of 90%.

Electric stimulation of the vagus nerve reduced mouse neuroinflammation induced by lipopolysaccharide

Background

Neuroinflammation (NI) is a key feature in the pathogenesis and progression of infectious and non-infectious neuropathologies, and its amelioration usually improves the patient outcome. Peripheral inflammation may promote NI through microglia and astrocytes activation, an increased expression of inflammatory mediators and vascular permeability that may lead to neurodegeneration. Several anti-inflammatory strategies have been proposed to control peripheral inflammation. Among them, electrical stimulation of the vagus nerve (VNS) recently emerged as an alternative to effectively attenuate peripheral inflammation in a variety of pathological conditions with few side effects.

Considering that NI underlies several neurologic pathologies we explored herein the possibility that electrically VNS can also exert anti-inflammatory effects in the brain.

Methods

NI was experimentally induced by intraperitoneal injection of bacterial lipopolysaccharide (LPS) in C57BL/6 male mice; VNS with constant voltage (5 Hz, 0.75 mA, 2 ms) was applied for 30 s, 48 or 72 h after lipopolysaccharide injection. Twenty four hours later, pro-inflammatory cytokines (IL-1β, IL-6, TNFα) levels were measured by ELISA in brain and spleen extracts and total brain cells were isolated and microglia and macrophage proliferation and activation was assessed by flow cytometry. The level of ionized calcium binding adaptor molecule (Iba-1) and glial fibrillary acidic protein (GFAP) were estimated in whole brain extracts and in histologic slides by Western blot and immunohistochemistry, respectively.

Results

VNS significantly reduced the central levels of pro-inflammatory cytokines and the percentage of microglia (CD11b/CD45^low) and macrophages (CD11b/CD45^high), 24 h after the electrical stimulus in LPS stimulated mice. A significantly reduced level of Iba-1 expression was also observed in whole brain extracts and in the hippocampus, suggesting a reduction in activated microglia.

Conclusions

VNS is a feasible therapeutic tool to attenuate the NI reaction. Considering that NI accompanies different neuropathologies VNS is a relevant alternative to modulate NI, of particular interest for chronic neurological diseases.

API determination by NIR spectroscopy across pharmaceutical production process

The purpose of this research was to demonstrate the ability of reflectance near-infrared (NIR) spectroscopy for quantitative analysis of an active ingredient in different production steps of a solid formulation. The drug is quantified at two different steps of a pharmaceutical process: after granulation and after tablet coating. Calibration samples were prepared by mixing pure drug, excipients, and batch samples (75-120 mg/g active ingredient) using a simple methodology that can be easily carried out in a laboratory. Partial least squares calibration models were calculated in second-derivative mode using the wavelength range 1,134-1,798 nm. The error of prediction for granulated samples was 1.01% and 1.63% for tablets. The results prove that NIR spectroscopy is a good alternative to other, more time-consuming means of analysis for pharmaceutical process monitoring.

Preparing calibration sets for use in pharmaceutical analysis by NIR spectroscopy

A new methodology for constructing calibration sets based on the use of laboratory samples encompassing the same variability sources as production samples was developed. The proposed methodology requires the use of no reference method in order to obtain reference values for the analyte; also, it provides more simple and robust calibration models than does the conventional methodology while retaining its predictive capacity. The procedure involves subjecting a set of laboratory samples spanning the desired API concentration range to a granulation treatment similar to that of the industrial process in order to obtain samples with the same physical variability as the production samples. The laboratory samples thus obtained are used to develop partial least squares (PLS1) calibration models in order to quantify the API in a pharmaceutical granulate. Based on the results obtained in this work, NIR spectroscopy is an effective alternative to the reference methods currently used for calibration. The proposed methodology requires no reference values to construct models; therefore, it can be regarded as an absolute analytical method. Also, it confirms the advantages of NIR spectroscopy as part of the process analytical technology (PAT) used by the pharmaceutical industry. A second aim has been the use of the multiplicative curve resolution-alternating least squares (MCR-ALS) algorithm to examine potential polymorphic transformations of the API during granulation.

Granulocyte colony-stimulating factor induces neutrophils to secrete macrophage colony-stimulating factor

In this work we provide evidence showing that granulocytes produce macrophage colony-stimulating factor (M-CSF) from the band cell stage and secrete this factor when induced to differentiate into polymorphonuclear cells by recombinant human granulocyte colony-stimulating factor (rhG-CSF). Using an enriched population of myeloid band cells from murine bone marrow, we identified the presence of M-CSF with a chromophore-labelled monoclonal anti-M-CSF antibody. Using ELISA we detected the secretion of M-CSF in the supernatants of cultures of enriched band cells when induced with rhG-CSF to differentiate into mature neutrophils. We also found that M-CSF is the only factor responsible for the colony forming activity in the supernatants and lysates of band cells treated with rhG-CSF.

Practice patterns versus practice guidelines in pediatric otitis media

OBJECTIVE

To study the practice patterns of physicians and their adherence to an evidence-based practice guideline (PG) on pediatric otitis media with effusion. We hypothesized that overall knowledge of the recommendations from the guidelines would be less than 75%, and that specialist physicians would have better knowledge of the recommendations than generalist physicians.

METHODS

We performed a survey study of 1167 otolaryngologists, pediatricians, and pediatric otolaryngologists. Each physician was sent a 6-item survey asking about their practice patterns and treatment preferences for young children with otitis media with effusion. We compared responses between different specialties.

RESULTS

The overall response rate was 48%. Only 8 (1.4%) of the 558 responding physicians answered all 6 items congruent with the PG. Overall, pediatricians, otolaryngologists, and pediatric otolaryngologists had similar total scores, but different scores on individual items.

CONCLUSIONS

These results indicate that the practice patterns of pediatricians, otolaryngologists, and pediatric otolaryngologists differ from the recommendations of an evidence-based PG. In particular, 2 items covering key treatment recommendations were answered in agreement with the PG by fewer than half of the physicians. It is not clear from this study whether these discrepancies were due to poor dissemination or knowledge concerning the PG, or disagreement with its recommendations.

Thalamic vascular lesions. Risk factors and clinical course for infarcts and hemorrhages

BACKGROUND AND PURPOSE

The data of patients with an MRI-confirmed diagnosis of thalamic stroke were analyzed to identify risk factors and to describe the clinical syndromes according to the thalamic arterial territory involved.

METHODS

We examined the records of all patients with a diagnosis of thalamic stroke confirmed by MRI who attended the National Institute of Neurology and Neurosurgery "Manuel Velasco Suárez" from 1987 through 1995. A database containing demographic features, risk factors, clinical course, type and mechanism of stroke, and vascular territory was analyzed.

RESULTS

Twenty-eight patients (19 men and 9 women; mean age, 48.2 years) had MRI-confirmed thalamic stroke. Infarct was present in 22 patients and hemorrhage in 6. Eleven (39.3%) patients were younger than 45 years. In these young patients, cigarette smoking was the main risk factor associated with the development of stroke. In young patients, isolated and multiple thalamic lesions were present in almost equal proportions. The remaining 17 patients were older adults (45 to 84 years of age). In such patients, most lesions were multiple and were associated with atherosclerosis-predisposing factors. The main distinguishing clinical feature for hemorrhages and paramedian infarcts in comparison with infarcts in the other thalamic territories was the presence of an altered level of consciousness. No patient died as a direct result of the stroke.

CONCLUSIONS

Thalamic stroke commonly occurs in young adults. and its mechanism is often undetermined. Increased awareness of this type of stroke in young adults should lead to better delineation of its clinical features, course, and management.

[Prevalence of drinkers at risk and associated factors among men attending primary care clinics]

OBJECTIVES

To quantify the prevalence of risk drinkers among men seeking health care, establish consumption patterns and relate them to socio-demographic features and health habits.

DESIGN

Crossover study. First phase of an experimental study.

SETTING

Four primary care teams in Area 10, Madrid.

PATIENTS

Males between 18 and 65 who attended for on-demand medical care. A systematic sample was selected (n = 562).

MEASUREMENTS

A questionnaire collecting socio-demographic characteristics, health habits and alcohol consumption (frequency, consumption pattern, intake of Weekly Units of alcohol (WU) and alcohol-related problems). 94.2% replied. 38% were habitual drinkers (drink four or more days a week), while 18.9% were week-end drinkers. Prevalence of drinkers consuming over 21 WU was 24.8%; and over 35 WU, 16.2%. Whether the cut-off point was fixed at 21 or 35 WU. The alcohol taken was related to educational level, physical exercise, smoking and taking other drugs. On average, single people, smokers, other drug-consumers, ex-drinkers and habitual drinkers were those who displayed most problems connected with alcohol consumption.

CONCLUSIONS

There is a similar profile of health habits for the groups consuming over 21 WU and 35 WU, which should make preventive care pay attention to both groups of drinkers.

Microbiological aspects in the hydroxylation of estrogens by Fusarium moniliforme

A strain of Fusarium moniliforme (IH4), isolated from soil, showed outstanding enzymatic abilities to hydroxylate a number of estrogens. Estrone and estradiol were transformed into the 15alpha-hydroxy derivatives, and estradiol 3-methyl ether was transformed into the corresponding 6beta-hydroxy derivative. Delta(6)-Estrone was not hydroxylated. The accumulation of 15alpha-hydroxyestrone was influenced by the nutritional conditions of the fungus. Maximal yield was obtained when the organism grew in Czapek solution supplemented with yeast extract, although good conversion was also found in a peptone-corn molasses medium. Substitution of NO(3)-N in Czapek medium with NH(4)-N, lactalbumin hydrolysate, Casitone, or Casamino Acids resulted in limited hydroxylation of estrone. A remarkable strain specificity was demonstrated in this conversion. Of 13 strains of F. moniliforme and Gibberella fujikuroi under investigation, only 2 strains (IH4 and ATCC 9851) accumulated substantial amounts of the 15alpha-hydroxylated product. However, marked quantitative variations were observed which are attributable to a different ability of the organisms to degrade the steroid nucleus. Biochemical instabilities were also found through the appearance of spontaneous variants lacking steroid-hydroxylating activity. Replacement culture studies revealed that 15alpha-hydroxylation of estrone was dependent on the supply of external phosphate; exogenous nitrogen or energy sources were not required. Most of the enzymatic activity was confined to the mycelia. Microconidia showed a very limited hydroxylating activity, even in the presence of supplements or energy sources.